Updated on 2022/05/26

写真a

 
NISHIDE, Hiroyuki
 
Affiliation
Faculty of Science and Engineering
Job title
Professor Emeritus

Education

  •  
    -
    1975

    Waseda University   Graduate School of Science and Engineering   Applied Chemistry  

  •  
    -
    1970

    Waseda University   School of Science and Engineering   Applied Chemistry  

Degree

  • Waseda University   Dr. Eng.

Research Experience

  • 2011
    -
     

    The Federation of Asian Polymer Societies, President

  • 2009
    -
    2011

    Japan Union of Chemical Science and Technology

  • 2010
    -
     

    Visiting Professor at University of Yamanashi, Gwangju Institute of Science and Technology

  • 2006
    -
    2008

    The Society of Polymer Science, President

  • 1987
    -
     

    Waseda University, Professor

  • 1982
    -
    1986

    Waseda University, Associate Professor

  • 1982
    -
    1986

    Waseda University, Associate Professor

  • 1980
    -
    1982

    Waseda University, Lecturer

  • 1977
    -
    1978

    Humbolat Fellow(Germany)

  • 1975
    -
    1977

    JSPS Fellow

▼display all

Professional Memberships

  •  
     
     

    The Chemical Society of Japan

  •  
     
     

    The Federation of Asian Polymer Societies

  •  
     
     

    The Chemical Society of Japan

  •  
     
     

    Japan Union of Chemical Science and Technology

 

Research Areas

  • Polymer chemistry

  • Functional solid state chemistry

Research Interests

  • Polymer Synthesis, Functional Polymers

Research Seeds

Papers

  • Simultaneous visualization of oxygen partial pressure, current density, and water droplets in serpentine fuel cell during power generation for understanding reaction distributions

    Kazuhiro Takanohashi, Takeo Suga, Makoto Uchida, Toshihide Ueda, Yuzo Nagumo, Junji Inukai, Hiroyuki Nishide, Masahiro Watanabe

    JOURNAL OF POWER SOURCES   343   135 - 141  2017.03  [Refereed]

     View Summary

    Understanding the reaction distributions inside a polymer electrolyte fuel cell (PEFC) is essential for the higher performance and durability. We have developed a new see-through cell and visualized the distributions of oxygen partial pressure and current density inside a running PEFC at the temperature of 40 and 80 degrees C and the relative humidity of 53%. The oxygen utilization was changed from 0% to 80% by changing the current density. At higher oxygen utilizations, the current density was higher and therefore the water generation. Generated water droplets in the flow channel were also visualized, allowing for the simultaneous visualization of the distribution of the oxygen partial pressure, current density, and water droplets. By combining the observations of all three parameters, the reactions inside a membrane electrode assembly were discussed. (C) 2017 Elsevier B.V. All rights reserved.

    DOI

  • Quantifying TEMPO Redox Polymer Charge Transport Towards the Organic Radical Battery

    C. Karlsson, T. Suga, H. Nishide

    ACS Applied Materials & Interfaces    2017  [Refereed]

  • Synthesis of Dimethyl-Substituted Polyviologen and Control of Charge Transport in Electrodes for High-Resolution Electrochromic Displays

    K. Sato, R. Mizukami, T. Mizuma, H. Nishide, K. Oyaizu

    Polymers   9   86  2017  [Refereed]

  • Charge–Discharge with Rocking-Chair-Type Li+ Migration Characteristics in a Zwitterionic Radical Copolymer Composed of TEMPO and Trifluoromethanesulfonylimide with Carbonate Electrolytes for a High-Rate Li-Ion Battery

    H. Tokue, T. Murata, H. Agatsuma, H. Nishide, K. Oyaizu

    Macromolecules    2017  [Refereed]

  • Low‐Cost, Organic Light‐Emitting Electrochemical Cells with Mass‐Producible Nanoimprinted Substrates Made Using Roll‐to‐Roll Methods

    K. Sato, S. Uchida, S. Toriyama, S. Nishimura, K. Oyaizu, H. Nishide, Y. Nishikitani

    Advanced Materials Technologies    2017  [Refereed]

  • Redox Mediation through TEMPO-Substituted Polymer with Nanogap Electrodes for Electrochemical Amplification

    H. Tokue, K. Kakitani, H. Nishide, K. Oyaizu

    Chemistry Letters   46  2017  [Refereed]

  • Water-Induced Phase Transition in Cyclohexane/n-Hexanol/Triton X-100 Mixtures at a Molar Composition of 1/16/74 Studied by NMR

    M. E. Flores, F. Martinez, A. F. Olea, T. Shibue, N. Sugimura, H. Nishide, I. Moreno-Villoslada

    The Journal of Physical Chemistry B    2017  [Refereed]

  • A Hydrogen Storable Quinaldine Polymer: Its Ni‐Electrodeposition‐assisted Hydrogenation and Subsequent Hydrogen Evolution

    R. Kato, T. Oya, Y. Shimazaki, K. Oyaizu, H. Nishide

    Polymer International   66   647 - 652  2017  [Refereed]

  • Effect of pi-Conjugated Polyelectrolyte on Performance of White Polymer Light-Emitting Diodes Based on Excitons and Exciplexes Having Long Intermolecular Distances

    Yoshinori Nishikitani, Noriyasu Inokuchi, Hiroyuki Nishide, Soichi Uchida, Toshihiko Shibanuma, Suzushi Nishimura

    JOURNAL OF PHYSICAL CHEMISTRY C   120 ( 26 ) 13976 - 13986  2016.07  [Refereed]

     View Summary

    The authors studied white polymer light emitting diodes (PLEDs) based on blue exciton emission by poly(9,9-di-n-dodecylfluorenyl-2,7-diyl) (PFD) and orange-to red emission from exciplexes formed at the interface between the PFD and poly(4-methyl-triphenylamine-co-acetoaldehyde) (TPA-AA). It is thought that the orange-to-red light-emitting exciplexes formed at the TPA-AA/PFD interface have intermolecular charge-transfer (CT) characteristics, namely, TPA-Ag+.PFD-, in which TPA-AA and PFD act as a donor (D) and an acceptor (A), respectively, and long intermolecular distances. TPA-AA is a nonconjugated polymer with good solubility in chloroform and acts as a hole transport layer (HTL). A bilayer PLED, ITO (indium tin oxide)/TPA-AA/PFD/Al, was fabricated by spin-coating, and white electroluminescence (EL), corresponding to Commission Internationale d'Eclairage (CIE) chromaticity coordinates of (0.36, 0.28) and a brightness of 39.6 cd/m(2), was achieved at 16 V. In order to decrease the turn-on voltage and enhance brightness, a pi-conjugated polyelectrolyte, poly(9,9-bis[6'-(N,N,N,-trimethylammonium)hexyl]fluorine-co-alt-1,4-phenylene) bromide (PFN+Br-), was used as an electron injection layer (EIL). This trilayer PLED, ITO/TPA-AA/PFD/PFN+Br-/Al, showed white EL corresponding to CIE chromaticity coordinates of (0.25, 0.31) and a brightness of 1450 cd/m(2) at 14 V. In the bilayer PLEDs, orange-to-red exciplex emission at similar to 630 nm was dominant at a low applied voltage, while at high voltage, blue exciton emission at similar to 430 nm and excimer emission at similar to 490 nm were comparable in strength to the exciplex emission. Meanwhile, the trilayer PLEDs showed mainly blue exciton emission at low voltage, and orange-to-red exciplex emission that was comparable in strength to the exciton emission at high voltage. These results can be explained by the different degrees of hole accumulation at the TPA-AA/PFD interface, which affects the electric field distribution in the PFD layer and the EL emission processes. Based on the applied voltage dependence of the emission colors of the bilayer and trilayer PLEDs, two types of models, namely, PLED band diagrams and Marcus-type molecular diagrams that represent hole transfer from TPA-AA to PFD, were proposed to explain the working principles of the devices. The working principles presented in this manuscript are different from the recently proposed working principle based on the Auger mechanism for small-molecule organic light-emitting diodes (OLEDs) based on D/A heterojunctions (He et al., Adv. Mater. 2016, 28, 649-654). Having a detailed understanding of the working principles is critical for designing efficient OLEDs, and our models give a new insight into the working principles of OLEDs based on D/A heterojunctions. Furthermore, these models provide a useful means of realizing efficient white PLEDs based on blue exciton emission and orange-to-red exciplex emission.

    DOI

  • Metallopolyyne polymers with ferrocenyl pendant ligands as cathode active materials for organic battery application

    Zhengong Meng, Kan Sato, Takashi Sukegawa, Kenichi Oyaizu, Cheuk-Lam Ho, Jing Xiang, Ying-Hsuan Feng, Yih Hsing Lo, Hiroyuki Nishide, Wai-Yeung Wong

    JOURNAL OF ORGANOMETALLIC CHEMISTRY   812   51 - 55  2016.06  [Refereed]

     View Summary

    Two bis(acetylide)-functionalized platinum(II) polymers containing ferrocenyl pendant ligands, trans[(-Pt(PBu3n)(2)-C CRC C-)(n) P1 (R = 9-ferrocenylmethylene-2,7-diethynylfluorene) and P2 (R = ferrocenylmethylene-2,5-diethynylbenzene), were prepared in good yields and were characterized by NMR spectroscopy and GPC. Electrochemical characteristics with copolymers P1 and P2 as the cathode active materials for rechargeable lithium batteries showed chemical and electrochemical reversibility. The thin layer polymer electrodes of P1 and P2 exhibited reversible redox peaks at the potentials of 0.54 and 0.64 V (vs. Ag/AgCl), respectively. The P1 or P2/carbon composites are also used as cathode-active materials to enhance the conductivity and durability. The electrodes exhibited good cycle life of over 50 charging/discharging cycles and no reversible n-type redox abilities seemed to be available. (C) 2015 Elsevier B.V. All rights reserved.

    DOI

  • Aerogels Containing 5, 10, 15, 20-tetrakis-(4-sulfonatophenyl)-porphyrin with Controlled State of Aggregation

    J. P. Pino-Pinto, F. Oyarzun-Ampuero, S. L Orellana, M. E Flores, H. Nishide, I. Moreno-Villoslada

    Dyes and Pigments   139   193 - 200  2016  [Refereed]

  • An Investigation of the Hydrophobic Property Stability of Grafted Polymeric Coatings on a Cellulose Material Surface

    VV Klimov, EV Bryuzgin, MD Le, EA Zelenova, TH Nguyen, AV Navrotskii, H. Nishide, IA Novakov

    Polymer Science Series D   9   364 - 367  2016  [Refereed]

  • Electrochemical current rectification with cross reaction at a TEMPO/viologen-substituted polymer thin-layer heterojunction

    H. Tokue, K. Kakitani, H. Nishide, K. Oyaizu

    RSC ADVANCES   6 ( 101 ) 99195 - 99201  2016  [Refereed]

     View Summary

    Totally reversible redox-active polymers, 4-amino-2,2,6,6-tetramethylpiperidin-1-oxyl functionalized polyacrylic acid (PTAm-A) and poly(tripyridiniomesitylene) (PTPM), both of which possessed rapid charge transport properties in an aqueous electrolyte, were applied to a polymer-sandwiched device to offer an electrochemical current rectification functionality. Single-layer and bilayer devices were fabricated employing the PTAm-A and/or PTPM thin layer(s) as charge transport media. Single-layer devices with a 1 cm(2) electrode area demonstrated large currents in the order of several milliamperes, which were established by redox mediation based on a fast electron self-exchange reaction between adjacent redox sites in the polymer layers. A current-voltage response obtained from the bilayer device exhibited a rectification effect due to thermodynamically favoured cross reaction at the polymer/polymer interface, retaining the large current densities. The observed currents were comparable to those predicted from the diffusion-controlled charge transport kinetics. Potentiostatic measurements revealed that the rectified current readily achieved a steady state in response to the applied voltage. These results demonstrate that the PTAm-A/PTPM thin-layer heterojunction enabled a large current rectification based on the redox mediation process, providing insight into ideal charge flow systems in various electrochemical devices.

    DOI

  • A Ketone/alcohol Polymer for Cycle of Electrolytic Hydrogen-fixing with Water and Releasing under Mild Conditions

    R. Kato, K. Yoshimasa, T. Egashira, T. Oya, K. Oyaizu, H. Nishide

    Nature Communications   7  2016  [Refereed]

  • A Quasi-Solid State DSSC with 10.1% Efficiency through Molecular Design of the Charge-Separation and-Transport

    M. Suzuka, N. Hayashi, T. Sekiguchi, K. Sumioka, M. Takata, N. Hayo, H. Ikeda, K. Oyaizu, H. Nishide

    Scientific Reports   6   28022  2016  [Refereed]

  • Poly(norbornyl-NDIs) as a potential cathode-active material in rechargeable charge storage devices

    Y. Sasada, S. J. Langford, K. Oyaizu, H. Nishide

    RSC ADVANCES   6 ( 49 ) 42911 - 42916  2016  [Refereed]

     View Summary

    Two pendant-type naphthalene diimide (NDI) polymers bearing a polynorbornene backbone were prepared and their electrochemical properties explored. The NDI-based polymers displayed reversible redox responses in 1 M LiClO4 gamma-butyrolactone electrolyte. Polymer 1, bearing a N-methyl group, exhibited remarkable charge-storage capabilities which demonstrated its potential usefulness as an organic cathode-active material in rechargeable devices with excellent performances such as large charge capacity, high rate capability, and charge-discharge cyclability.

    DOI

  • Enhanced catalytic activity of oxovanadium complexes in oxidative polymerization of diphenyl disulfide

    Fuyuki Aida, Yohei Takatori, Daichi Kiyokawa, Kentaro Nagamatsu, Kenichi Oyaizu, Hiroyuki Nishide

    POLYMER CHEMISTRY   7 ( 11 ) 2087 - 2091  2016  [Refereed]

     View Summary

    Oxygen-oxidative polymerization of diphenyl disulfide gives poly(1,4-phenylene sulfide) (PPS), catalyzed by a vanadyl complex and a protic acid. N,N'-Ethylenebis(salicylideneaminato)oxovanadium(IV) (VO(salen)) which has been reported to be catalytically inactive at ambient temperature because of the insufficient reactivity of its oxidized state, an oxovanadium(V) complex, for the oxidation of the monomer turned out to exhibit an excellent catalytic activity on raising the reaction temperature above 100 degrees C. The enhanced reactivity of VO(salen)-acid or bis(2,4-pentanedionato)oxovanadium(IV) (VO(acac)(2))-acid catalytic systems at elevated temperatures gave insight into the catalytic mechanism where oxidation of the monomer with the oxovanadium(V) complex dominated the reactivity, which was also accelerated by a second redox shuttle molecule, such as quinones with a potential near that of the [VO(salen)](0/+) couple.

    DOI

  • Synthesis and Charge-Discharge Properties of Organometallic Copolymers of Ferrocene and Triphenylamine as Cathode Active Materials for Organic-Battery Applications

    J. Xiang, K. Sato, H. Tokue, K. Oyaizu, CL. Ho, H. Nishide, WY. Wong, MD. Wei

    Euro. J. Inorg, Chem.     1030 - 1035  2016  [Refereed]

  • A family of substituted hydrazonoisoxazolones with potential biological properties

    Carlos Bustos, Elies Molins, Juan-Guillermo Carcamo, Marcelo N. Aguilar, Christian Sanchez, Ignacio Moreno-Villoslada, Hiroyuki Nishide, Ximena Zarate, Eduardo Schott

    NEW JOURNAL OF CHEMISTRY   40 ( 3 ) 2156 - 2167  2016  [Refereed]

     View Summary

    The synthesis, characterization and biological study of a new 3,4,5-trisubstituted isoxazolones have been reported, whereby a series of (Z)-3-methyl-4-(2-(R-phenyl) hydrazinylidene) isoxazol-5(4H)-ones were prepared by the reaction of a beta-diketohydrazone with hydroxylammonium chloride. All the products were characterized using EA, UV-Vis, FT-IR, H-1-NMR, C-13-NMR spectroscopy and HMBC. The crystalline and molecular structures of three compounds were solved by X-ray diffraction methods. Density functional theory (DFT) and time-dependent DFT (TDDFT) calculations were performed to obtain a better explanation of the observed experimental behaviour of these newly synthetized compounds. Furthermore, the reports of cytotoxicity and an antiproliferative effect in human promyelocytic leukaemia cells, HL-60, was tested by the MTT reduction method, showing that most of the newly synthetized compounds had important antineoplastic activity. The most active isoxazolones were used in reverse transcription polymerase chain reaction (RT-PCR) experiments to determine the effect on the expression levels on mRNA encoding using the anti-apoptotic, Bcl 2, pro-apoptotic, Bax, and the proliferation inhibition, p21(WAF-1), proteins. Therefore, it was possible to fully characterize the complete library of 15 isoxazolones and to show that most of them are antineoplastic trough an apoptotic pathway.

    DOI

  • Dynamic switching of ionic conductivity by cooperative interaction of polyviologen and liquid crystals for efficient charge storage

    Kan Sato, Takaaki Yamasaki, Takahiro Mizuma, Kenichi Oyaizu, Hiroyuki Nishide

    JOURNAL OF MATERIALS CHEMISTRY A   4 ( 9 ) 3249 - 3252  2016  [Refereed]

     View Summary

    The ionic conductivity of a liquid crystal electrolyte was switched along with redox reactions of polyviologen. The surface charge of the polymer determined the alignment and the bulk conductivity of the electrolyte. The cooperative switching firstly enabled the suppression of self-discharging and quick-response, giving rise to facile and persistent charge storage.

    DOI

  • "Click" Incorporation of Radical/Ionic Sites into a Reactive Block Copolymer: A Facile and On-Demand Domain Functionalization Approach toward Organic Resistive Memory

    Takeo Suga, Kohei Aoki, Toshiaki Yashiro, Hiroyuki Nishide

    MACROMOLECULAR RAPID COMMUNICATIONS   37 ( 1 ) 53 - 59  2016.01  [Refereed]

     View Summary

    Reversible addition-fragmentation chain transfer polymerization yields reactive block copolymers bearing the pentafluorophenyl ester (PFPA) group, and subsequent Click amidation using 2,2,6,6-tetramethylpiperidine-N-oxyl- and imidazolium-functionalized primary amines produces the corresponding functional block copolymers, leading to installation of statistical radical-and ionic sites into the PFPA segment. The monolayered thin film devices fabricated using the obtained block copolymers exhibit repeatable switching of electric conductivity (on/off ratio > 10(3)) under a bias voltage, which reveals that the coexistence of radicals and ions in the same spherical domain of the copolymer layer is a prerequisite for repeatable switching memory.

    DOI

  • Correlation between H-1 NMR chemical shifts of hydroxyl protons in n-hexanol/cyclohexane and molecular association properties investigated using density functional theory

    Mario E. Flores, Toshimichi Shibue, Natsuhiko Sugimura, Hiroyuki Nishide, Ignacio Moreno-Villoslada

    CHEMICAL PHYSICS LETTERS   644   276 - 279  2016.01  [Refereed]

     View Summary

    Association of n-hexanol molecules in cyclohexane forming clusters is studied by DFT and H-1 NMR. Geometry optimization, corrected binding energies, charge distributions, charge transfer energies, and 1H NMR chemical shifts have been obtained. The calculated chemical shifts of hydroxyl protons have been correlated to experimental data obtained in the range of n-hexanol molar fraction between 0.002 and 0.2, showing that n-hexanol molecules at a molar fraction around 0.1, where well-structured hydrogen bond networks are observed, tend to form linear pentamers and hexamers. The experimental data are consistent with the continuous linear association thermodynamic model, showing a dimensionless association constant of 284. (C) 2015 Elsevier B.V. All rights reserved.

    DOI

  • Stability of Water/Poly(ethylene oxide)(43)-b-poly(epsilon-caprolactone)(14)/Cyclohexanone Emulsions Involves Water Exchange between the Core and the Bulk

    Mario E. Flores, Francisco Martinez, Andres F. Olea, Toshimichi Shibue, Natsuhiko Sugimura, Hiroyuki Nishide, Ignacio Moreno-Villoslada

    JOURNAL OF PHYSICAL CHEMISTRY B   119 ( 52 ) 15929 - 15937  2015.12  [Refereed]

     View Summary

    The formation of emulsions upon reverse self-association of the monodisperse amphiphilic block copolymer poly(ethylene oxide)(43)-b-poly(epsilon-caprolactone)(14) in cydohexanone is reported. Such emulsions are not formed in toluene, chloroform, or dichloromethane. We demonstrate by magnetic resonance spectroscopy the active role of the solvent on the stabilization of the emulsions. Cyclohexanone shows high affinity for both blocks, as predicted by the Hansen solubility parameters, so that the copolymer chains are fully dissolved as monomeric chains. In addition, the solvent is able to produce hydrogen bonding with water molecules. Water undergoes molecular exchange between water molecules associated with the polymer and water molecules associated with the solvent, dynamics of major importance for the stabilization of the emulsions. Association of polymeric chains forming reverse aggregates is induced by water over a concentration threshold of 5 wt %. Reverse copolymer aggregates show submicron average hydrodynamic diameters, as seen by dynamic light scattering, depending on the polymer and water concentration.

    DOI

  • White Polymer Light-Emitting Electrochemical Cells Fabricated Using Energy Donor and Acceptor Fluorescent pi-Conjugated Polymers Based on Concepts of Band-Structure Engineering

    Yoshinori Nishikitani, Daisuke Takizawa, Hiroyuki Nishide, Soichi Uchida, Suzushi Nishimura

    JOURNAL OF PHYSICAL CHEMISTRY C   119 ( 52 ) 28701 - 28710  2015.12  [Refereed]

     View Summary

    The authors report on white polymer light-emitting electrochemical cells (PLECs) fabricated with a polymer blend film composed of a blue fluorescent pi-conjugated polymer (blue FCP), poly(9,9-di-n-dodecylfluoreny1-2,7-diyl) (PFD), and a red-orange FCP, poly[2-methoxy-5-(2'-ethylhexyloxy)-1,4-phenylenevinylene] (MEH-PPV), based on concepts of band-structure engineering. Polymer blending is one of the simplest and most promising methods for fabrication of van der Waals interfaces, which convert electricity to light in PLECs. By optimizing the composition of PFD, MEH-PPV, poly(ethylene oxide) (PEO), and salt (KCF3SO3) in the active layer, white-light emission with Commission Internationale de l'Edairage (CIE) coordinates of (x = 0.33, y = 0.31) can be achieved through light mixing of blue exciton emission from PFD and red-orange exciton emission from MEH-PPV at an applied voltage higher than the threshold voltage,141,"-FcP, which corresponds to E-g(blue)-(FCP)/e, where E-g(blue-FCP) is the band gap of PFD and e is the elemental charge. The white light produced by light mixing of PFD and MEH-PPV emissions can be obtained at a low MEH-PPV concentration, while only red-orange emissions from MEH-PPV are obtained at high MEH-PPV concentrations. The emission color of FCP-blend PLECs can be explained by Forster resonance energy transfer (FRET) from the excited PFD to the MEH-PPV because the photoluminescence (PL) spectrum of PFD overlaps with the UV vis absorption spectrum of MEH-PPV. However, FRET was limited by the presence of PEO in the active layers of the FCP-blend PLECs. This meant it was much easier to tune the emission colors compared to FCP-blend polymer light-emitting diodes (PLEDs), in which FRET occurs predominantly. Utilization of a polymer blend film of blue and red-orange FCPs in PLECs is a very effective and promising method for fabrication of white light-emitting devices.

    DOI

  • Photochromic Solid Materials Based on Poly(decylviologen) Complexed with Alginate and Poly(sodium 4-styrenesulfonate)

    Luis Sanhueza, Joaquin Castro, Esteban Urzua, Lorena Barrientos, Felipe Oyarzun-Ampuero, Hector Pesenti, Toshimichi Shibue, Natsuhiko Sugimura, Wataru Tomita, Hiroyuki Nishide, Ignacio Moreno-Villoslada

    JOURNAL OF PHYSICAL CHEMISTRY B   119 ( 41 ) 13208 - 13217  2015.10  [Refereed]

     View Summary

    Photochromic solid materials based on the cationic polymer poly(decylviologen) are reported. The solids were obtained by freeze-drying colloidal suspensions of nanocomplexes obtained by mixing aqueous solutions of the polycation with different solutions of polyanions such as poly(sodium 4-styrenesulfonate) or sodium alginate, at a cationic/anionic polymeric charge ratio of 0.7. The photochromic responses of the solid materials fabricated with alginate as complementary charged polyelectrolyte of the cationic polyviologen are faster than those of the solid materials fabricated with poly(sodium 4-styrenesulfonate), achieving coloration kinetics in the order of minutes, and discoloration kinetics in the order of hours for the former. Aromatic-aromatic interactions between the latter polyanion and the polyviologen may stabilize the dicationic form of the viologen derivative, increasing the necessary energy to undergo photoreduction, thus decreasing the reduction kinetics.

    DOI

  • Visualization of Oxygen Partial Pressure and Numerical Simulation of a Running Polymer Electrolyte Fuel Cell with Straight Flow Channels to Elucidate Reaction Distributions

    Katsuya Nagase, Haruki Motegi, Masakazu Yoneda, Yuzo Nagumo, Takeo Suga, Makoto Uchida, Junji Inukai, Hiroyuki Nishide, Masahiro Watanabe

    CHEMELECTROCHEM   2 ( 10 ) 1495 - 1501  2015.10  [Refereed]

     View Summary

    Visualization of the oxygen partial pressure (p(O(2))) was performed at the surface of a gas diffusion layer (GDL) and the upper part of the gas-flow channel of the cathode of an operating polymer electrolyte fuel cell (PEFC) with straight flow channels by using an oxygen-sensitive luminescent dye film. The gradient of p(O(2)) inside a channel was clearly observed, even on the GDL surface across the channel. A numerical simulation was performed to understand the reaction distributions inside the PEFC. By visualization and numerical simulation, the distributions of p(O(2)), the current density, water concentration, and temperature in the operating PEFC were obtained, and the relationships between the parameters were studied. Supersaturated water inside the cell was found both experimentally and computationally. p(O(2)) and the water concentration were concluded to be the two most important factors in determining the distribution of power generation.

    DOI

  • Ionic Liquid-Triggered Redox Molecule Placement in Block Copolymer Nanotemplates toward an Organic Resistive Memory

    Takeo Suga, Kohei Aoki, Hiroyuki Nishide

    ACS MACRO LETTERS   4 ( 9 ) 892 - 896  2015.09  [Refereed]

     View Summary

    The integration of functional components such as metal nanoparticles, metal salts, or ionic liquids with well-defined block copolymer (BCP) nanotemplates via non-covalent bond interactions has afforded hybrid functional materials. Here, we designed an ionic liquid (IL)-functionalized redox-active TEMPO (2,2,6,6-tetramethylpiperidine-N-oxy) radical (guest), investigated phase-selective incorporation/placement into host BCP nanostructured matrices, and established a rational approach to functionalize BCP templates. On-demand domain functionalization of poly(styrene-b-ethyl-ene oxide) (PS-b-PEO) was triggered by ion-ionophore interaction, as verified by the suppression of PEO melting transition in DSC, and the swelling behavior of the PEO spherical domain in AFM, TEM, and X-ray scattering characterizations. The obtained BCP layer containing the redox-active TEMPO and IL was utilized as an active layer in the diode-structured memory device, which exhibited on/off resistive switching (on/off ratio >10(3)). Systematic placement of TEMPO and IL in the BCP spherical domain allowed for tuning of the switching characteristics and revealed that the formation of a discontinuous redox-active domain was critical for rewritable resistive switching.

    DOI

  • Vanadyl-TrBR4-Catalyzed Oxidative Polymerization of Diphenyl Disulfide

    Fuyuki Aida, Souske Yamaguchi, Yohei Takatori, Kentaro Nagamatsu, Daichi Kiyokawa, Kenichi Oyaizu, Hiroyuki Nishide

    MACROMOLECULAR CHEMISTRY AND PHYSICS   216 ( 18 ) 1850 - 1855  2015.09  [Refereed]

     View Summary

    A newly established catalyst system for oxygen-oxidative polymerization of diphenyl disulfide is reported. Combination of vanadyl compounds (e.g., VO(acac)(2)) and triphenylmethylium tetrakis(pentafluorophenyl) borate (TrB(C6F5)(4)) proceeds the polymerization to give poly(1,4-phenylene sulfide) (PPS) at 100 degrees C. When triphenylmethylium tetrafluoroborate (TrBF4) is applied with vanadyl tetraphenylporphyrin (VO(TPP)) or N,N'-(ethylenebis(salicylideneaminato)) oxovanadium (VO(salen)), PPS is also given via polymerization under conditions near 160 degrees C. Combination of the vanadyl complex and the borate affords the first protic-acid-free catalytic system for the polymerization of the disulfide, suggesting the overall reaction to produce PPS and H2O from O-2 and protons that are eliminated from the monomer.

    DOI

  • Poly(1,4-phenylene sulfide) (PPS) Synthesis via Oxidative Polymerization of Diphenyl Disulfide: Mechanistic Insight into the Selective Formation of 1,4-Thiophenylene Chain

    Fuyuki Aida, Yohei Takatori, Daichi Kiyokawa, Kentaro Nagamatsu, Hiroyuki Nishide, Kenichi Oyaizu

    CHEMISTRY LETTERS   44 ( 6 ) 767 - 769  2015.06  [Refereed]

     View Summary

    Oxidative polymerization of diphenyl disulfide under molten conditions at moderately elevated temperatures gave poly(1,4-phenylene sulfide) (PPS), using a vanadyl complex strong acid catalyst with oxygen as the ultimate oxidant. Origin of the selectivity of the sulfonium electrophile for the formation of the 1,4-thiophenylene chain, characterized by the presence of a disulfide bond at the chain end, was determined by the behavior of polymerization and structural analysis of the product together with a computational calculation, which revealed a unique chain growth-type polycondensation process.

    DOI

  • Facile grafting-onto-preparation of block copolymers of TEMPO and glycidyl methacrylates on an oxide substrate as an electrode-active layer

    Katsuyuki Takahashi, Konstantine Korolev, Kazumasa Tsuji, Kenichi Oyaizu, Hiroyuki Nishide, Evgeny Bryuzgin, Alexander Navrotskiy, Ivan Novakov

    POLYMER   68   310 - 314  2015.06  [Refereed]

     View Summary

    Block copolymers of 2,2,6,6-tetramethyl-4-piperidyl methaaylate and glycidyl methactylate were prepared by atom transfer radical polymerization. The block copolymer was immobilized on an indium-doped tin oxide substrate by simply coating the copolymer solution and annealing. The copolymer layers were efficiently converted to those of the corresponding 2,2,6,6-tetramethylpiperidin-1-oxy (TEMPO) polymer. The TEMPO layers were swelled with but not eluted into common electrolyte solutions such as acetonitrile and ethylene carbonate, and showed excellent electrochemically reversible redox cycling at 0.81 V vs. Ag/AgCl. The layer with the thickness of micron meters exhibited both a sufficient charge diffusivity (10(-10) cm(2) s(-1)) and a very large storage capacity (beyond 120 mC cm(-2)), which was applicable to a cathode of organic-based rechargeable devices. (C) 2015 Elsevier Ltd. All rights reserved.

    DOI

  • Polyviologen as the charge-storage electrode of an aqueous electrolyte- and organic-based dye-sensitized solar cell

    Michio Suzuka, Shu Hara, Takashi Sekiguchi, Kenichi Oyaizu, Hiroyuki Nishide

    POLYMER   68   353 - 357  2015.06  [Refereed]

     View Summary

    A dye-sensitized solar cell (DSSC) was fabricated with a viologen polymer as a charge-storable electrode and an aqueous electrolyte. The polyviologen was prepared via electrolytic polymerization of the 4-cyanopyridine moiety: It displayed reversible two-electron redox reactions at -0.48 and -0.86 V vs. Ag/AgCl in the aqueous electrolyte, which were appropriate for the acceptance of an electron from the photo-anode or TiO2 conduction band by the charge-storable electrode. The DSSC using the polyviologen electrode achieved both photo-current generation with a high open-circuit voltage of ca. 0.8 V upon light irradiation, and a charge-supply after irradiation at a constant voltage of ca. 0.4 V with a discharging capacity of ca. 75% of the polyviologen electrode. The potential tuning of the organic-based polyviologen electrode was described. (C) 2015 Elsevier Ltd. All rights reserved.

    DOI

  • Synthesis of Poly(TEMPO-Substituted Glycidyl Ether) by Utilizing t-BuOK/18-Crown-6 for an Organic Cathode-Active Material

    Kan Sato, Takashi Sukegawa, Kenichi Oyaizu, Hiroyuki Nishide

    MACROMOLECULAR SYMPOSIA   351 ( 1 ) 90 - 96  2015.05  [Refereed]

     View Summary

    A nitroxide radical-substituted polyether, poly(TEMPO-substituted glycidyl ether) (PTGE), was synthesized using a potassium tert-butoxide/18-crown-6 initiator. The presence of 18-crown-6 effected significant improvement in the reactivity of the chain end, thus allowing the polymerization to proceed at moderate temperatures to suppress the deactivation of the pendant nitroxide group. A high molecular-weight polyether with a theoretical radical concentration was first obtained in high yield. Charging and discharging cyclability was much improved by cross-linking, which helped the electrode-active material stay on a current collector during the electrolysis. The polymer/vapor-grown carbon nanofiber composite electrode exhibited a redox capacity comparable to the formula weight-based theoretical density over 10(3) cycles and fast charging/discharging capability up to a rate of 60C which corresponded to full charging and discharging in 60s. The redox capacity was almost maintained for a composite layer with a remarkably high polymer ratio of 90%, which demonstrated the presence of effective percolation network of the carbon nanofiber due likely to the affinity of the polyether to the carbon material.

    DOI

  • High-Density and Robust Charge Storage with Poly(anthraquinone-substituted norbornene) for Organic Electrode-Active Materials in Polymer-Air Secondary Batteries

    Takuma Kawai, Kenichi Oyaizu, Hiroyuki Nishide

    MACROMOLECULES   48 ( 8 ) 2429 - 2434  2015.04  [Refereed]

     View Summary

    An excellent functional group tolerance of ruthenium complex catalysts for olefin metathesis gave rise to ring-opening polymerization of norbornene functionalized with redox-active anthraquinone (AQ) pendants, yielding a high-molecular-weight and processable polynorbornene with large redox capacity. A thin layer of the polymer cast on current collectors showed reversible redox reaction at -0.85 V vs Ag/AgCl when immersed in basic aqueous electrolyte solutions. Good cycle performance was observed with a capacity comparable to the formula weight-based theoretical density of 212 mAh/g, which was the largest among those for the previously reported redox-active polynorbornenes. This suggested that all of the AQ units in the layer were redox-active, that electroneutralization was accomplished by successive compensation of counterions throughout the layer, and that the mechanical strength of the polymer layer prevented dissolution or exfoliation from the current collector surface. A robust polymer-air secondary battery with the high capacity was fabricated by using the polymer layer as the anode-active material. The battery showed a discharge voltage of 0.68 V and long life of over 300 cycles of charging/discharging, maintaining the moderate energy density of 143 mWh/g.

    DOI

  • Electrochemical Formation of a Polyviologen-ZnO Composite with an Efficient Charging Capability

    Hirofumi Maruo, Kenichi Oyaizu, Hiroyuki Nishide

    CHEMISTRY LETTERS   44 ( 3 ) 393 - 395  2015.03  [Refereed]

     View Summary

    Concurrent and cathodic electrolysis of tris(cyanopyridinio)mesitylene and zinc chloride gave redox-active polyviologen, densely formed around the zinc oxide nanorod, on a substrate, which displayed a large charging discharging capacity and an excellent rate performance based on a large diffusivity of charge, and was useful as an anode-active material.

    DOI

  • Electrochemical Formation of a Polyviologen-ZnO Composite with an Efficient Charging Capability

    Hirofumi Maruo, Kenichi Oyaizu, Hiroyuki Nishide

    CHEMISTRY LETTERS   44 ( 3 ) 393 - 395  2015.03

     View Summary

    Concurrent and cathodic electrolysis of tris(cyanopyridinio)mesitylene and zinc chloride gave redox-active polyviologen, densely formed around the zinc oxide nanorod, on a substrate, which displayed a large charging discharging capacity and an excellent rate performance based on a large diffusivity of charge, and was useful as an anode-active material.

    DOI

  • Facile charge transport and storage by a TEMPO-populated redox mediating polymer integrated with polyaniline as electrical conducting path

    Kenichi Oyaizu, Hanae Tatsuhira, Hiroyuki Nishide

    POLYMER JOURNAL   47 ( 2 ) 212 - 219  2015.02  [Refereed]

     View Summary

    A copolymer of TEMPO-and aniline-substituted norbornene was prepared by ring-opening metathesis polymerization of the corresponding monomers. Electropolymerization of the pendant aniline groups in the copolymer gave a layer of polynorbornene populated with the redox-active TEMPO pendants, in which polyaniline chain was incorporated. Electroactivity of the TEMPO pendants throughout the layer and its excellent charging/discharging cyclability, in addition to the amorphous nature of the layer, suggested that the polyaniline chain was homogeneously dispersed in the layer and that each chain served as crosslinking moiety. The effect of the polyaniline chains was further enhanced when they were formed by in-situ electropolymerization of the aniline group in the preformed layer of the copolymer/polyaniline composite. The polyaniline chain served as a conducting path to reduce the charge-transfer resistance for redox mediation, which gave rise to an excellent rate performance for the charging/discharging process of the layer, compared with those for the composite layers of TEMPO-substituted polymers with polyaniline and other conductive additives prepared by the conventional grinding methods.

    DOI

  • White Polymer Light-emitting Electrochemical Cells Using Emission from Exciplexes with Long Intermolecular Distances Formed between Polyfluorene and Pi-conjugated Amine Molecules

    Y. Nishikitani, H. Takeuchi, H. Nishide, S. Uchida, S. Yazaki, S. Nishimura

    J. Applied Phys.   118   1 - 9  2015  [Refereed]

  • White Polymer Light-emitting Electrochemical Cells Using Emission from Exciplexes with Long Intermolecular Distances Formed between Polyfluorene and Pi-conjugated Amine Molecules

    Y. Nishikitani, H. Takeuchi, H. Nishide, S. Uchida, S. Yazaki, S. Nishimura

    J. Applied Phys.   118   1 - 9  2015

  • Oxygen-enriched electrolytes based on perfluorochemicals for high-capacity lithium-oxygen batteries

    Yuki Nishikami, Toshihiro Konishi, Ryo Omoda, Yuichi Aihara, Kenichi Oyaizu, Hiroyuki Nishide

    JOURNAL OF MATERIALS CHEMISTRY A   3 ( 20 ) 10845 - 10850  2015  [Refereed]

     View Summary

    Electrolytes highly enriched with oxygen for lithium-oxygen (Li-O-2) batteries were prepared by combining perfluorohexyl bromide as an oxygen-uptake perfluorochemical (PFC) medium with lithium perfluorooctane sulfonate (LiPFOS) as a perfluoro-surfactant and a supporting electrolyte, which allowed an exceptionally high miscibility of PFCs with tetraethylene glycol dimethyl ether (TEGDME). The electrochemical reduction current of oxygen was enhanced three times in the LiPFOS-TEGDME electrolyte with ca. 60 wt% PFC content in comparison with that of a conventional Li-O-2 battery electrolyte, which was ascribed to the high oxygen solubility of the electrolyte. A Li-O-2 cell fabricated with the PFC-based electrolyte exhibited an excellent discharging capacity of 6500 mA h g(-1) which was approximately 1.5 times higher than that obtained with the conventional electrolyte.

    DOI

  • Phenothiazine-functionalized redox polymers for a new cathode-active material

    Ali A. Golriz, Takeo Suga, Hiroyuki Nishide, Ruediger Berger, Jochen S. Gutmann

    RSC ADVANCES   5 ( 29 ) 22947 - 22950  2015  [Refereed]

     View Summary

    Redox-active, phenothiazine-functionalized polymers were synthesized and employed as a promising cathode-active material (similar to 3.7 V vs. Li, 77 Ah kg(-1)) in a rechargeable battery. The longer spacer between phenothiazine and the polymer backbone contributed to the stability of the formed radical cations, resulting in decelerated self-discharge and improved cycle performance.

    DOI

  • Real-time visualization of oxygen partial pressures in straight channels of running polymer electrolyte fuel cell with water plugging

    Katsuya Nagase, Takeo Suga, Yuzo Nagumo, Makoto Uchida, Junji Inukai, Hiroyuki Nishide, Masahiro Watanabe

    JOURNAL OF POWER SOURCES   273   873 - 877  2015.01  [Refereed]

     View Summary

    Visualization inside polymer electrolyte fuel cells (PEFCs) for elucidating the reaction distributions is expected to improve the performance, durability, and stability. An oxygen-sensitive film of a luminescent porphyrin was used to visualize the oxygen partial pressures in five straight gas-flow channels of a running PEFC with liquid-water blockages formed at the end of the channels. The blockage greatly lowered and unstabilized the cell voltage. The oxygen partial pressure decreased nearly to 0 kPa in the blocked channel. With a water blockage in a channel, the oxygen partial pressures in the adjacent channels were lowered due to an extra demand of oxygen consumption. When the number of the blocked channels increased, the oxygen partial pressure in the unblocked channels became much lowered. When the water blockages disappeared, the oxygen partial pressures quickly returned to the values before plugging. The influence of the cross flows of air through the gas diffusion layers in straight channels was much smaller than that in serpentine flow channels. (C) 2014 Elsevier B.V. All rights reserved.

    DOI

  • Self-association of 5,10,15,20-tetrakis-(4-sulfonatophenyl)-porphyrin tuned by poly(decylviologen) and sulfobutylether-beta-cyclodextrin

    Mario E. Flores, Naoki Sano, Rodrigo Araya-Hermosilla, Toshimichi Shibue, Andres F. Olea, Hiroyuki Nishide, Ignacio Moreno-Villoslada

    DYES AND PIGMENTS   112   262 - 273  2015.01  [Refereed]

     View Summary

    With the aim of achieving supramolecular structures containing dyes with controlled state of aggregation, the formation of ternary complexes between 5,10,15,20-tetrakis-(4-sulfonatophenyl)-porphyrin, poly(decylviologen), and sulfobutylether-beta-cyclodextrin at low excess of the cyclodextrin is described. By controlling the stoichiometry of the reactants, both non-fluorescent H-aggregates of the dye and stabilized fluorescent monomers may be obtained. The dye undergoes self-aggregation in the presence of the flexible, cationic polymer, and by addition of the negatively charged cyclodextrin the aggregates are cleaved. The cyclodextrin primarily induces the inclusion of 5,10,15,20-tetrakis-(4-sulfonatophenyl)-porphyrin in its cavity, and the ensemble is stabilized by the polymer by means of electrostatic, hydrophobic, and/or aromatic aromatic interactions. The ternary complex thus produced tends to nano-fiber formation, as seen by FE-TEM. (C) 2014 Elsevier Ltd. All rights reserved.

    DOI

  • Kinetic Control of Electron Transfer at Doped Zinc Oxide/Redox-active Molecule Interface for Photocurrent Rectification

    Michio Suzuka, Shu Hara, Takashi Sekiguchi, Kenichi Oyaizu, Hiroyuki Nishide

    CHEMISTRY LETTERS   44 ( 1 ) 41 - 43  2015.01  [Refereed]

     View Summary

    Reactivity of redox-active molecules for heterogeneous electron-transfer processes at the surface of doped zinc oxide substrates depended on their energy levels. The redox-active molecules with negative redox potentials displayed a reversible electrochemical response but those with positive redox potentials were characterized by slow electrode kinetics, which was attributed to more than three times larger heterogeneous electron-transfer rate constant for the former redox-active molecules. A photovoltaic cell using methyl viologen as an acceptor molecule, TEMPOL as a donor molecule, and the doped ZnO as the transparent conducting substrate gave high photovoltage, which was ascribed to the reactivity of the redox-active molecules at the doped ZnO surface.

    DOI

  • Efficient charge transport of a radical polyether/SWCNT composite electrode for an organic radical battery with high charge-storage density

    Takashi Sukegawa, Kan Sato, Kenichi Oyaizu, Hiroyuki Nishide

    RSC ADVANCES   5 ( 20 ) 15448 - 15452  2015  [Refereed]

     View Summary

    A crosslinked poly(4-glycidyloxy TEMPO) was synthesized via anionic ring-opening copolymerization of 4-glycidyloxy TEMPO and a diglycidyl ether using a pentaerythritol/phosphazene base initiator. A fast and reversible charge storage capability was established for the polyether/SWCNT composite layer with a large layer thickness of several tens of micrometres, despite the low SWCNT content of 10% which was much closer to the percolation limit than the amount required for the previously reported TEMPO-substituted polymethacrylate.

    DOI

  • New 3,4,5-Trisubstituted Isoxazoles Derivatives with potential biological properties

    C. Bustos, E. Molins, J.-G. Carcamo, M. Aguilar, C. O. Sanchez, I. Moreno-Villoslada, H. Nishide, A. Mesias, X. Zarate, E. Schott

    New J. Chem.    2015  [Refereed]

  • Oxygen partial pressures on gas-diffusion layer surface and gas-flow channel wall in polymer electrolyte fuel cell during power generation studied by visualization technique combined with numerical simulation

    Yuta Ishigami, Wihatmoko Waskitoaji, Masakazu Yoneda, Kenji Takada, Tsuyoshi Hyakutake, Takeo Suga, Makoto Uchida, Yuzo Nagumo, Junji Inukai, Hiroyuki Nishide, Masahiro Watanabe

    JOURNAL OF POWER SOURCES   269   556 - 564  2014.12  [Refereed]

     View Summary

    Visualization of the oxygen partial pressures was carried out at the surface of a gas diffusion layer (GDL) for the first time together with the upper part of the gas-flow channel of the cathode of a running polymer electrolyte fuel cell (PEFC) using two different oxygen-sensitive luminescent dye films. The visualized distributions of the oxygen partial pressures at the GDL and the upper gas-flow channel during the PEFC operation were very different in a conventional test cell. The change in the distribution of the oxygen partial pressures was observed by changing the oxygen utilization, which should be connected with the reactive locations in the membrane-electrode assembly (MEA). A numerical calculation was carried out to understand the distributions of water and current density inside the MEA. The water distribution inside the MEA was confirmed to strongly affect the distributions of the current density and the oxygen /partial pressure. (C) 2014 Elsevier B.V. All rights reserved.

    DOI

  • Expanding the Dimensionality of Polymers Populated with Organic Robust Radicals toward Flow Cell Application: Synthesis of TEMPO-Crowded Bottlebrush Polymers Using Anionic Polymerization and ROMP

    Takashi Sukegawa, Issei Masuko, Kenichi Oyaizu, Hiroyuki Nishide

    MACROMOLECULES   47 ( 24 ) 8611 - 8617  2014.12  [Refereed]

     View Summary

    Poly(norbornene)-g-poly(4-methacryloyloxy-2,2,6,6-tetramethylpiperidin-1-oxyl) (PNB-g-PTMA) was prepared by a grafting-through approach based on anionic polymerization of 4-methacryloyloxy-2,2,6,6-tetramethylpiperidin-1-oxyl using a norbornene-substituted diphenylhexyllithium to yield a norbornene-functionalized macromonomer (NB-PTMA) and subsequent ring-opening metathesis polymerization of NB-PTMA using a Grubbs third-generation catalyst, which avoided critical side reactions involving the nitroxide radical of TEMPO moiety. The anionic polymerization resulted in high yields (>94%), narrow polydispersity indices (<1.20), and radical concentrations (0.95 radicals per monomer unit). The ROMP also resulted in high yields (>98%) and high radical concentrations (0.95 radicals per monomer unit), by virtue of the functional group tolerance of these reactions. Single molecular dimension of PNB-g-PTMA was measured by dynamic light scattering and by atomic force microscopy (AFM), which precisely reflected the bottlebrush structure to reveal the presence of the TEMPO group crowded at the periphery of the molecule. The lengths of PNB-g-PTMA along the macromolecular side chains and the polynorbornene main chain were both approximately equal to the theoretical lengths estimated by the degree of polymerization for each chain. The number-average diameter of PNB-g-PTMA in THF increased with initial NB-PTMA ratio to the Grubbs catalyst. Photo-cross-linked thin layer electrodes of PNB-g-PTMA demonstrated the reversible redox reaction at 0.80 V vs Ag/AgCl corresponding to the TEMPO/TEMPO+ couple and quantitative charging/discharging processes even at 120 C rate (i.e., full charging in 30 s). As a novel application of redox-active polymers, PNB-g-PTMA exhibited 95% efficiency of the theoretical charge capacity in a flow cell system, based on the unique properties of bottlebrush polymers such as the defined molecular dimension and relatively low solution viscosity in comparison with corresponding linear polymers.

    DOI

  • n-Hexanol association in cyclohexane studied by NMR and NIR spectroscopies

    Mario E. Flores, Toshimichi Shibue, Natsuhiko Sugimura, Hiroyuki Nishide, Francisco Martinez, Andres F. Olea, Ignacio Moreno-Villoslada

    JOURNAL OF MOLECULAR LIQUIDS   199   301 - 308  2014.11  [Refereed]

     View Summary

    In this work we present a study on the association of n-hexanol in cyclohexane using NMR and NIR spectroscopies. Abrupt changes on spectroscopic responses have been observed at low molar fractions of n-hexanol, which are related to hydrogen bond network formation that includes trace water. Molecular interactions are found to be dominated by dispersion forces, hydrogen bonding, and dipolar interactions, to different extents at different n-hexanol composition ranges. 1D, DOSY, and T-1 and T-2 relaxation time analyses by H-1-NMR allow understanding the dynamics of the mixtures. NIR allows verifying the formation of n-hexanol polymeric species. In addition, an n-hexanol/cyclohexane mixture with an alcohol molar fraction of 0.177 has been titrated with water, revealing the formation of a microemulsion containing water droplets that evolves to a bicontinuous microemulsion with increasing water content. Stable boundary water is detected at the microemulsion interface. (C) 2014 Elsevier B.V. All rights reserved.

    DOI

  • Immobilization of Hydrophilic Low Molecular-Weight Molecules in Nanoparticles of Chitosan/Poly(sodium 4-styrenesulfonate) Assisted by Aromatic-Aromatic Interactions

    Juan Pablo Fuenzalida, Mario E. Flores, Ines Moniz, Miguel Feijoo, Francisco Goycoolea, Hiroyuki Nishide, Ignacio Moreno-Villoslada

    JOURNAL OF PHYSICAL CHEMISTRY B   118 ( 32 ) 9782 - 9791  2014.08  [Refereed]

     View Summary

    The immobilization of the hydrophilic low molecular-weight cationic molecules rhodamine 6G, methylene blue, and citidine in nanoparticles composed of two opposite charged polyelectrolytes, poly(sodium 4-styrenesulfonate) and chitosan, is studied, and the results correlated with their physicochemical properties. Nanoparticles containing both polyelectrolytes have been synthesized showing hydrodynamic diameters of around 200 nm and tunable zeta potential. It was found that the strength of binding of the cationic molecules to the polyanion bearing charged aromatic groups poly(sodium 4-styrenesulfonate) by means of short-range aromatic aromatic interactions increases with their hydrophobicity and polarizability, as seen by H-1 NMR and UV vis spectroscopies, and diafiltration. Consequently, association efficiencies of 45, 21, and 12% have been found for the three molecules, respectively, revealing the different ability of the molecules to be immobilized in the nanoparticles. These results provide a proof of concept on a new strategy of immobilization of hydrophilic low molecular-weight molecules based on aromatic aromatic interactions between polyelectrolytes and their aromatic counterions.

    DOI

  • Synthesis of Pendant Radical- and Ion-Containing Block Copolymers via Ring-Opening Metathesis Polymerization for Organic Resistive Memory

    Takeo Suga, Miki Sakata, Kohei Aoki, Hiroyuki Nishide

    ACS MACRO LETTERS   3 ( 8 ) 703 - 707  2014.08  [Refereed]

     View Summary

    Ring-opening metathesis polymerization (ROMP) using Grubbs third-generation catalyst directly yielded a norbornene-based polymer bearing robust redox-active radicals without any protection. Successive addition of imidazolium-containing norbomene in a one-pot reaction during ROMP produced pendant radical- and ion-containing block copolymers. The diode-structured thin-film devices fabricated with the obtained block polymers that had morphologies of spheres, lamellae, and inverse spheres exhibited conductive switching (write-once read-many-times, WORM) under a bias voltage, which revealed the dominant effect of the location of radicals and ions in the microphase-segregated domains on memory characteristics.

    DOI

  • Interaction of Tris(2-aminoethyl)amine-based Ureas and Thiourea with Superoxide Anion and Peroxide Dianion through Multiple Hydrogen Bonding

    Natsuru Chikushi, Yuki Nishikami, Hiroyuld Nishide

    CHEMISTRY LETTERS   43 ( 6 ) 760 - 762  2014.06  [Refereed]

     View Summary

    Tris(2-aminoethyl)amine-based urea and thiourea derivatives interacted with a superoxide anion (O-2(-)) and peroxide dianion (O-2(2-)): The redox potential of oxygen was positively shifted with the molecules through their multiple-hydrogen-bond donor ability.

    DOI

  • Porphyrin Network Polymers Prepared via a Click Reaction and Facilitated Oxygen Permeation Through Their Membranes

    Natsuru Chikushi, Emiko Ohara, Ayako Hisama, Hiroyuki Nishide

    MACROMOLECULAR RAPID COMMUNICATIONS   35 ( 10 ) 976 - 980  2014.05  [Refereed]

     View Summary

    Network polymers of cobaltporphyrin derivatives are prepared by a facile click reaction via the Michael addition of acetoacetate-substituted tetraphenyl cobaltporphyrin and tri- or tetra-acrylates. The conversion is saturated for 1 h in the presence of a catalyst, which almost reaches the same gelation point of the formed network polymers. Deeply and homogeneously red-colored membranes with a sub-micrometer thickness are yielded on a porous supporting membrane. They are still tough even with a very high content of the rigid porphyrin residue. The oxygen permeability is high, at 10-100 Barrer, and the oxygen/nitrogen permselectivity (P-O2/P-N2) is significantly enhanced with the porphyrin content reaching 30, for the membranes with ca. 70 wt% porphyrin content.

    DOI

  • Adsorption of a Carboxylic Acid-Functionalized Aminoxyl Radical onto SiO2

    Hidenori Murata, Martha Baskett, Hiroyuki Nishide, Paul M. Lahti

    LANGMUIR   30 ( 14 ) 4026 - 4032  2014.04  [Refereed]

     View Summary

    Silicon wafers both without and with silicon(IV) oxide surface coverage were covered with benzene solutions of stable organic radical 3-(N-tert-butyl-N-aminoxyl)benzoic acid (mNBA). X-ray photoelectron spectroscopy supported the presence of the radical on both surface-cleaned (oxide-reduced) and oxide-covered surfaces. Optical waveguide spectroscopy showed that the radical retained its structure while adsorbed to the surface of the wafers, without noticeable decomposition. AFM and MFM imaging showed that the radical formed blocky particles with a change in rms roughness from 0.3 nm premodification to 1.7 nm postmodification on the surface-cleaned silicon. Similar experiments using oxide-coated silicon showed that the radical adsorbed to form much smoother layers, with a small change in rms roughness from 0.2 to 0.3 nm. Contact angle measurements of water on the premodified and postmodified samples showed a large, hydrophobic change in the silicon oxide surface but only a modest change in the surface-cleaned silicon surface. Samples of mNBA adsorbed onto silica gel showed strong electron-spin resonance signals from the aminoxyl spin, even years after production. The results demonstrate the prospects for treating and coating oxide-covered silicon wafers and silicon oxide-coated particles with a paramagnetically active organic substrate, without major chemical modification of the pretreatment surface; the resulting organic spin sites can be stable for years.

    DOI

  • Anionic Polymerization of 4-Methacryloyloxy-TEMPO Using an MMA-Capped Initiator

    Takashi Sukegawa, Hajime Omata, Issei Masuko, Kenichi Oyaizu, Hiroyuki Nishide

    ACS MACRO LETTERS   3 ( 3 ) 240 - 243  2014.03  [Refereed]

     View Summary

    Anionic polymerization of 4-methacryloyloxy-TEMPO (TEMPO = 2,2,6,6-tetramethylpiperidin-1-oxyl) was successfully carried out using methyl methacrylate-capped 1,1-diphenylhexyllithium (DPHLi/MMA), of which nucleophilicity is moderate enough to suppress the side reaction between the nitroxide radical of TEMPO moiety and the carbanion of DPHLi, to yield the radical polymer with well-controlled molecular weight, narrow polydispersity index (PDI < 1.10), high yield (>95%), and almost 1.0 radicals per monomer unit.

    DOI

  • Redox-active Hydroxy-TEMPO Radical Immobilized in Nafion Layer for Aqueous Electrolyte-based and Dye-sensitized Solar Cell

    R. Kato, F. Kato, K. Oyaizu, H. Nishide

    Chem. Lett.   43 ( 4 ) 480 - 482  2014  [Refereed]

  • TEMPO/viologen Electrochemical Heterojunction for Diffusion Controlled Redox Mediation: A Highly Rectifying Bilayer-sandwiched Device Based on Cross Reaction at Interface

    H. Tokue, K. Oyaizu, T. Sukegawa, H. Nishide

    ACS Appl. Mater. Interfaces   6   4043 - 4049  2014  [Refereed]

  • Ionic liquid-inspired redox shuttles: Properties of a ferrocenylimidazolium-salt as an efficient mediator for dye sensitized solar cell

    K. Oyaizu, H. Ikeda, N. Hayo, F. Kato, H. Nishide

    Chem. Lett.   43   1134 - 1136  2014  [Refereed]

  • In-situ Polymerization of Thiophene Derivatives Using a Gas-phase Oxidant to Form a Hole-transporting Layer in Dye-sensitized Solar Cell

    Yoshito Sasada, Fumiaki Kato, Kenichi Oyaizu, Hiroyuki Nishide

    JOURNAL OF PHOTOPOLYMER SCIENCE AND TECHNOLOGY   27 ( 3 ) 347 - 350  2014  [Refereed]

     View Summary

    Poly(3,4-ethylenedioxythiophene) (PEDOT), for use as a hole-transporting layer in dye-sensitized solar cells (DSSCs), was synthesized via in-situ polymerization using a gas-phase oxidant. Highly volatile iodine was used as the gas-phase oxidant to fill up a porous TiO2 substrate. The conductivity of PEDOT increased to 0.9 S/cm upon the addition of a base, 4-tert-butylpyridine, to the monomer solution. A solid-state DSSC was fabricated using PEDOT as the hole-transporting layer, which displayed photo-electric conversion.

  • Facile charge transport and storage by a TEMPO-populated redox mediating polymer integrated with polyaniline as electrical conducting path

    K. Oyaizu, H. Tatsuhira, H. Nishide

    Polym. J.   47   1 - 8  2014  [Refereed]

  • Thermosensitive block-copolymers grafted on aluminium surface for lyophilic properties control

    E. Bryuzgin, A. Navrotskiy, T. Hyakutake, I. Novakov, H. Nishide

    J. Nanostructured Polym. Nanoccomposites   9   97 - 101  2014  [Refereed]

  • Controlling the aggregation of 5,10,15,20-tetrakis-(4-sulfonatophenyl)-porphyrin by the use of polycations derived from polyketones bearing charged aromatic groups

    Claudio Toncelli, Juan Pablo Pino-Pinto, Naoki Sano, Francesco Picchioni, Antonius A. Broekhuis, Hiroyuki Nishide, Ignacio Moreno-Villoslada

    DYES AND PIGMENTS   98 ( 1 ) 51 - 63  2013.07  [Refereed]

     View Summary

    The interaction between 5,10,15,20-tetrakis-(4-sulfonatophenyl)-porphyrin and different polycations is studied by UV-vis spectroscopy. Two polycations containing charged aromatic residues (imidazolium and pyridinium) have been easily synthesized by Paal-Knorr reaction of alternating aliphatic polyketones with histamine and 4-picolylamine. It was found that these polymers stabilize the tetra-anionic form of the porphyrin at acidic conditions, and avoid the formation of H- and J-type self-aggregates. Other polycations such as poly(allylamine) and poly(decylviologen) enhance porphyrin self-aggregation. As the latter polymer has also aromatic charged groups, the influence of the polymer structure as a whole in the behavior of the porphyrin/polycation system is highlighted. In this context, similar but not equal results have been found comparing the influence of the polyketone derivative containing pyridinium groups and the polycation poly(4-vinylpyridine) on the porphyrin self-aggregation and acid base behavior. (C) 2013 Elsevier Ltd. All rights reserved.

    DOI

  • One-pot, Radiation-induced Graft Polymerization of Vinylsulfonic Acid onto Poly(ether ether ketone) and High Proton Conductivity of Its Membrane

    Katsuyuki Takahashi, Hiroyuki Nishide

    CHEMISTRY LETTERS   42 ( 3 ) 218 - 219  2013.03  [Refereed]

     View Summary

    A poly(vinylsulfonic acid) (PVSA)-grafted poly(ether ether ketone) (PEEK) was simply prepared by one-pot, gamma-ray radiation-induced graft polymerization of the vinylsulfonic acid (VSA) solution dissolving PEEK. The VSA-highly-grafted PEEK membrane possessed high ion exchange capacity (e.g., 7.2 mequiv g(-1)) and showed proton conductivity in the order of 10(-1) and 10(-3)-10(-6) S cm(-1) under hydrated and nonhumidified conditions, respectively.

    DOI

  • Polyviologen Hydrogel with High-Rate Capability for Anodes toward an Aqueous Electrolyte-Type and Organic-Based Rechargeable Device

    Naoki Sano, Wataru Tomita, Shu Hara, Cheong-Min Min, Jae-Suk Lee, Kenichi Oyaizu, Hiroyuki Nishide

    ACS APPLIED MATERIALS & INTERFACES   5 ( 4 ) 1355 - 1361  2013.02  [Refereed]

     View Summary

    A highly cross-linked polyviologen hydrogel, poly(tripyridiniomesitylene) (PTPM), has been designed as an anode-active material. It displays a reversible two-electron redox capability at -0.4 and -0.8 V vs Ag/AgCl in an aqueous electrolyte. The PTPM layer coated on a current collector by electropolymerization via a 4-cyanopyridinium electro-coupling reaction demonstrates a rapid charging-discharging reaction with a redox capacity comparable to that obtainable using the formula weight-based theoretical density, because of the combination of the redox-active viologen moieties built into the hydrogel. A test cell that has been fabricated using the developed PTPM anode, a poly(2,2,6,6-tetramethylpiperidinyloxy-4-yl acrylamide) (PTAm)-based cathode, and an aqueous electrolyte exhibits a discharging voltage of 1.1 and 1.5 V, and has proven its ability to be recharged more than 2000 times.

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  • Self-doping inspired zwitterionic pendant design of radical polymers toward a rocking-chair-type organic cathode-active material

    Il Seok Chae, Masafumi Koyano, Kenichi Oyaizu, Hiroyuki Nishide

    Journal of Materials Chemistry A   1 ( 4 ) 1326 - 1333  2013.01  [Refereed]

     View Summary

    'Self-doping' inspired high-density redox copolymers were designed and prepared via free radical copolymerization of 2,2,6,6-tetramethyl-4-piperidyl methacrylate and vinylsulfonic acid (VSA) with a view to preventing a change in salt concentration during the one-electron oxidation of the nitroxide radicals to N-oxoammonium cations in a polymer layer. A copolymer composition of TEMPO-sulfonate anionic group = 1/1 for density-maximized charge neutralization was achieved by controlling the feed ratio of the copolymerization. The formation of copolymers was evidenced by 2D nuclear Overhauser enhanced spectroscopy (NOESY) and diffusion ordered spectroscopy (DOSY) NMR. Poly(TEMPO methacrylate-stat-VSA) was considered to have the alternating tendency due to the acid-base interaction in the comonomers, which were supported not only by the single crystal structure of the 2,2,6,6-tetramethyl-4-piperidyl methacrylate and VSA complex, but also by the 1H-1H correlation in NOE signals. In an aqueous electrolyte with 0.5 M NaCl, the copolymer electrode showed a redox response near 0.66 V (vs. Ag/AgCl), and the excellent cycle performance during 1000 cycles. During the one-electron oxidation of the nitroxide radical, anionic sulfonate groups led to charge compensation of the N-oxoammonium cation. Consequently, the copolymer electrode exhibited the cation migration, which was evidenced by mass-transfer analysis using an electrochemical quartz crystal microbalance (EQCM) technique. The copolymer could be applied as an aqueous electrolyte-type organic rechargeable device. Moreover, this design proposes the ultimate principle toward the strategy of maximizing energy density in organic charge storage devices. © The Royal Society of Chemistry 2013.

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  • TEMPO-substituted polyacrylamide for an aqueous electrolyte-typed and organic-based rechargeable device

    Natsuru Chikushi, Hiroshi Yamada, Kenichi Oyaizu, Hiroyuki Nishide

    SCIENCE CHINA-CHEMISTRY   55 ( 5 ) 822 - 829  2012.05  [Refereed]

     View Summary

    A hydrophilic radical polymer, poly(2,2,6,6-teteramethylpiperidinyloxyl-4-yl acrylamide) (PTAm), was synthesized via oxidation of the corresponding precursor polymer, poly(2,2,6,6-teteramethylpiperidine-4-yl acrylamide). Electrochemical properties of the PTAm layer were characterized in three aqueous electrolytes of sodium chloride (NaCl), sodium tetrafluoroborate (NaBF4), and sodium hexafluorophosphate (NaPF6) to optimize its activity as an organic cathode. The counter anion species significantly affected the capacity and the cycle performance of the PTAm layer. The PTAm layer in the presence of BF4 (-1) displayed quantitative redox capacity beyond 1 mu m layer thickness and maintained the discharging capacity of 110 mAh g(-1) (97% vs. the calculated capacity) even after 1000 cycle charging/discharging, which could be ascribed to its appropriate affinity to the aqueous electrolyte without any dissolution into the electrolyte. A totally organic-based rechargeable cell was fabricated using PTAm and poly(N-4,4'-bipyridinium-N-decamethylene dibromide) as the cathode and the anode, respectively, and the aqueous electrolyte of NaBF4. The cell gave a plateau voltage at 1.2 V both on charging and discharging and an excellent charging/discharging cyclability of > 2000 with high coulombic efficiency of > 95%.

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  • Electrospinning of radical polymers: redox-active fibrous membrane formation

    Takeo Suga, Matthew T. Hunley, Timothy E. Long, Hiroyuki Nishide

    POLYMER JOURNAL   44 ( 3 ) 264 - 268  2012.03  [Refereed]

     View Summary

    Redox-active but highly durable nitroxide radicals, that is, 2,2,6,6-tetramethylpiperidinyl-4-oxy (TEMPO), enabled direct electrospinning of radical-containing polymers without additional processing aids (such as polymer blends, post-doping, or protection/deprotection) and produced redox-active fibrous membranes with high surface area. The solution rheological behavior of the TEMPO-substituted polymethacrylate was similar to the neutral conventional polymers, and electrospinning of the radical polymers yielded submicrometer-scaled fibrous membranes without any defects on the radical moiety. The obtained membrane exhibited stable redox response, leading to redox catalysts or electrode-active materials toward organic-based flexible rechargeable battery. Polymer Journal (2012) 44, 264-268; doi:10.1038/pj.2011.120; published online 7 December 2011

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  • Grafted polyelectrolyte coatings on aluminum surface for hydrophilic properties control

    E. V. Bryuzgin, K. Takahashi, A. V. Navrotsky, H. Nishide, I. A. Novakov

    PROTECTION OF METALS AND PHYSICAL CHEMISTRY OF SURFACES   48 ( 2 ) 184 - 190  2012.03  [Refereed]

     View Summary

    Grafted polyelectrolyte coatings were obtained by surface-initiated atom transfer radical polymerization on an aluminum surface. Their chemical composition was verified by X-ray photoelectron spectroscopy and Fourier transfer infrared spectroscopy. The morphology of grafted polymer coatings on an aluminium surface was studied by atomic-force and scanning electron microscopy and the possibility of adjusting its hydrophilic properties in wide range was established.

    DOI

  • Real-time visualization of CO 2 generated by corrosion of the carbon support in a PEFC cathode

    Ishigami, Y, Maeda, I, Takada, K, Hyakutake, T, Suga, T, Inukai, J, Uchida, M, Nagumo, Y, Nishide, H, Watanabe, M

    Electrochemical and Solid-State Letters   15 ( 4 ) B51 - B53  2012  [Refereed]

  • Indoline Dye-Coupled Polyviologens: Its Electrochemical Property and Electropolymerization

    N. Sano, M. Suzuki, W. Tomita, K. Oyaizu, H. Nishide

    Japanese Journal of Applied Physics, 51   51 ( 10 ) 10NE17  2012  [Refereed]

  • Synthesis of Pendant Nitronyl Nitroxide Radical-containing Poly(norbornene)s as Ambipolar Electrode-Active Materials

    T. Sukegawa, A. Kai, K. Oyaizu, H. Nishide

    Macromolecules   46 ( 4 ) 1361 - 1367  2012  [Refereed]

  • Aqueous Electrochemistry of Poly(vinylanthraquinone) for Anode-Active Materials in High-Density and Rechargeable Polymer/Air Batteries

    Wonsung Choi, Daisuke Harada, Kenichi Oyaizu, Hiroyuki Nishide

    JOURNAL OF THE AMERICAN CHEMICAL SOCIETY   133 ( 49 ) 19839 - 19843  2011.12  [Refereed]

     View Summary

    A layer of poly(2-vinylanthraquinone) on current collectors underwent reversible electrode reaction at 0.82 V vs Ag/AgCl in an aqueous electrolyte. A repeatable charging/discharging cycles with a redox capacity comparable to the formula weight-based theoretical density at the negative potential suggested that all of the anthraquinone pendants in the layer was redox-active, that electroneutralization by an electrolyte cation was accomplished throughout the polymer layer, and that the layer stayed on the current collector without exfoliation or dissolution into the electrolyte during the electrolysis. The charging/discharging behavior of the polymer layer in the aqueous electrolyte revealed the capability of undergoing electrochemistry even in the nonsolvent of the pendant group, which offered insight into the nature of the anthraquinone pendants populated on the aliphatic chain. Charging/discharging capability of air batteries was accomplished by using the polymer layer as an organic anode-active material. A test cell fabricated using the conventional MnO(2)/C cathode catalyst exhibited a discharging voltage at 0.63 V corresponding to their potential gap and a charging/discharging cycle of more than 500 cycles without loss of the capacity.

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  • Designing current collector/composite electrode interfacial structure of organic radical battery

    Sunao Yoshihara, Haruhiko Katsuta, Hiroshi Isozumi, Masanori Kasai, Kenichi Oyaizu, Hiroyuki Nishide

    JOURNAL OF POWER SOURCES   196 ( 18 ) 7806 - 7811  2011.09  [Refereed]

     View Summary

    Charge/discharge processes of organic radical batteries based on the radical polymer's redox reaction should be largely influenced by the structure and the composition of the composite electrodes. AC impedance measurement of the composite electrodes reveals a strong correlation between the overall electron transfer resistance of the composite electrode and the material of the current collector, and suggests that the electric conduction to the current collector through the contact resistance should be crucial. We also find that the adhesion and the contact area between the composite electrode and the current collector strongly influence the contact resistance rather than the work functions and the volume resistivities of the composite electrode and the current collector. It is also confirmed that the charge/discharge performance of the composite electrode is related to the overall electron transfer resistance of the composite electrode. These results indicate that the charge/discharge performance of the radical battery is dominated by the interfacial electron transfer processes at the current collector/carbon fiber interface. In fact, the composite electrode which has a high adhesion to the current collector shows a small overall electron transfer resistance and an excellent charge/discharge performance. The rate performance would be much improved by suitably designing the interfacial structure including adhesion and contact area. (C) 2010 Elsevier B.V. All rights reserved.

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  • Functionalization of poly(4-chloromethylstyrene) with anthraquinone pendants for organic anode-active materials

    Kenichi Oyaizu, Wonsung Choi, Hiroyuki Nishide

    POLYMERS FOR ADVANCED TECHNOLOGIES   22 ( 8 ) 1242 - 1247  2011.08  [Refereed]

     View Summary

    Condensation of anthraquinone-2-carboxylic acid with poly(4-chloromethylstyrene) afforded a high-density redox polymer containing the anthraquinone pendants with reversible charge storage capability at negative potentials near -1V versus Ag/AgCl. Electrochemically reversible redox response of the polymer, which was ascribed to the reduction of the pendant group to the anion radical and the dianion, suggested that the polymer was sufficiently robust in these redox states for charge storage application. Immobilizing the anthraquinone groups on current collectors was accomplished by the use of the polymer which was swellable and yet insoluble in both aqueous and nonaqueous electrolyte solutions. Such properties allowed the accommodation of external cations from the electrolyte solution to permeate through the polymer layer for electroneutralization of the negative charge produced at the reduced state, which led to the repeatable charging and discharging cycles without degradation of the charge storage capacity. Exploration of the aqueous electrochemistry of anthraquinone, which had been inaccessible by the lack of the solubility of the conjugated and fused-ring molecule in H2O, became feasible by virtue of the swelling property of the polymer layer in the aqueous electrolyte. While negative charge was relatively difficult to be stored with redox polymers compared to the positive charge due to the enhanced reactivity in their reduced states and small varieties of the appropriate redox sites, the present polymer was characterized as the excellent organic electrode-active materials that operated at sufficiently negative potentials which was essential for the fabrication of entirely organic batteries. Copyright (C) 2011 John Wiley & Sons, Ltd.

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  • Sulfonic acid polymer-densely grafted poly(ethersulfone)s for a highly proton-conducting membrane

    Teruyuki Okayasu, Koji Hirose, Hiroyuki Nishide

    POLYMERS FOR ADVANCED TECHNOLOGIES   22 ( 8 ) 1229 - 1234  2011.08  [Refereed]

     View Summary

    Proton-conducting polyelectrolytes were prepared by densely grafting novel sulfonic acid polymers, poly(styrene-sulfamide acid) (PSA) and poly(vinylsulfonic acid) (PVS), on the azo-initiator-modified poly(ethersulfone) (PSU). The grafted PSUs provided both a high ion-exchange capacity (IEC) and a good membrane formability. The proton-conductivities of the PSA-g-PSU and PVS-g-PSU membranes were 8.2 and 21mS cm(-1), respectively, at 90 degrees C under a hydrated condition, and 4.1 and 1.7mS cm(-1), respectively, at 150 degrees C under a nonhumidified condition. The latter conductivities were significantly higher than that of Nafion (R) 117 (0.03mS cm(-1) at 150 degrees C), which was ascribed to both the strong acidity of the graft chains even under the water-free state and the high IEC of the densely grafted membrane. They remained constant for over 1 week at 150 degrees C. Copyright (C) 2011 John Wiley & Sons, Ltd.

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  • Imaging of Water Droplets Formed during PEFC Operation on GDLs with Different Pore Sizes

    Kenji Takada, Yuta Ishigami, Satoki Hirakata, Makoto Uchida, Yuzo Nagumo, Junji Inukai, Hiroyuki Nishide, Masahiro Watanabe

    ELECTROCHEMISTRY   79 ( 5 ) 388 - 391  2011.05  [Refereed]

     View Summary

    Gas diffusion layer (GDL) is an important component for the performance of polymer electrolyte fuel cells controlling the gas flow and the water transport. In this study, the real-time formation process of water droplets on two GDLs with different pore sizes was imaged using a CCD camera during the cell operation. A porphyrin luminescent dye was coated on the GDLs to clarify the shape of the water droplets. On the GDL with a smaller pore size, the droplets were distributed uniformly on the GDL in the flow channel at the cathode. On the GDL with a larger pore size, the water droplets were larger and formed mainly near the ribs of the flow channel, and the droplets were observed to move slowly towards the gas outlet. The difference in the formation of water droplets were explained by the difference in the partial air flow inside the GDLs along the gas channel.

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  • Free Radical Polymerization Kinetics of Vinylsulfonic Acid and Highly Acidic Properties of its Polymer

    Teruyuki Okayasu, Toshiyasu Hibino, Hiroyuki Nishide

    MACROMOLECULAR CHEMISTRY AND PHYSICS   212 ( 10 ) 1072 - 1079  2011.05  [Refereed]

     View Summary

    Poly(vinylsulfonic acid) (PVS) possesses a high acid content (ion-exchange capacity in the chemical formula 9.2 meq . g(-1)). Its monomer, vinylsulfonic acid (VSA), had a high acid dissociation ability (Hammett acid function 0.74 in water), and a high ionic conductivity (0.04-0.11 S . cm(-1)). The radical polymerization of VSA with various initiators was kinetically investigated. The ESR spectrum of the VSA polymerization mixture showed a strong signal ascribed to the propagation carbon radical of VSA. The molecular weight of PVS increased with the increasing monomer concentration and decreasing radical initiator concentration to yield the PVS with a molecular weight of 4.0 x 10(4). Proton-conductivity of PVS under hydrated and nonhumidified conditions was on the order of 10(-1) and 10(-3)-10(-6) S . cm(-1), respectively.

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  • Organic Radical Battery Approaching Practical Use

    Kentaro Nakahara, Kenichi Oyaizu, Hiroyuki Nishide

    CHEMISTRY LETTERS   40 ( 3 ) 222 - 227  2011.03  [Refereed]

     View Summary

    The electrochemical redox reactions of organic polymers bearing robust unpaired electrons were investigated to determine the applicability of these polymers to rechargeable batteries. Such an "organic radical battery" would be environmentally friendly and have high-power characteristics. This highlight review describes the performance of a battery using a nitroxyl radical polymer as the cathode active material. The electron-transfer mechanism and recent developments that should lead to the practical application of the organic radical battery are also described.

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  • Simultaneous visualization of oxygen distribution and water blockages in an operating triple-serpentine polymer electrolyte fuel cell

    Kenji Takada, Yuta Ishigami, Junji Inukai, Yuzo Nagumo, Hiroshi Takano, Hiroyuki Nishide, Masahiro Watanabe

    JOURNAL OF POWER SOURCES   196 ( 5 ) 2635 - 2639  2011.03  [Refereed]

     View Summary

    Visualization inside polymer electrolyte fuel cells (PEFCs) is important for elucidating reaction distributions to improve the performance and durability of the cells. An O(2)-sensitive porphyrin luminescent dye film was used to visualize oxygen partial pressures and water blockages simultaneously in triple-serpentine gas flow channels in an operating PEFC. Water droplets formed near the exit of a gas-flow channel lowered the oxygen partial pressure noticeably over the channel by blocking air flow near the entrance. Meanwhile, air was continuously supplied from the other channels through the gas diffusion layer, thus allowing power to be generated in the blocked channel. With water blockages, however, the catalyst layer under the channel became flooded by the water produced during the reaction, and the flooded state continued to exist in the catalyst and/or porous layers, even after blowing the water droplet out, so that the power generation was lowered along the channel. (C) 2010 Elsevier B.V. All rights reserved.

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  • Corrosion of carbon supports at cathode during hydrogen/air replacement at anode studied by visualization of oxygen partial pressures in a PEFC-Start-up/shut-down simulation

    Yuta Ishigami, Kenji Takada, Hiroshi Yano, Junji Inukai, Makoto Uchida, Yuzo Nagumo, Tsuyoshi Hyakutake, Hiroyuki Nishide, Masahiro Watanabe

    JOURNAL OF POWER SOURCES   196 ( 6 ) 3003 - 3008  2011.03  [Refereed]

     View Summary

    During start-up/shut-down processes of a polymer electrolyte fuel cell, platinum particles are lost from the catalyst layer at the cathode due to corrosion of the carbon supports. We simulated the start-up/shut-down cycle by exchanging gases at the anode between hydrogen and air. During the gas exchange, the distribution of oxygen partial pressures at the anode was visualized by our real-time/space visualization system, which clearly showed the location of H-2- and O-2-rich areas along the gas-flow channel from the inlet to the outlet. The gas exchange rate was found to be much slower than that predicted from the simple replacement and to be correlated to the proton transfer derived from carbon corrosion of the cathode catalyst layer. By the visualization results, it was found that the shut-down process gives more serious effect than the start-up process. After the degradation, the oxygen partial pressure at the cathode was visualized during the cell operation. Oxygen was consumed mainly in the middle of the MEA because the MEA was degraded mainly near the inlet and outlet of reactant gases in the cell. (C) 2010 Elsevier B.V. All rights reserved.

    DOI

  • Dual Dopable Poly(phenylacetylene) with Nitronyl Nitroxide Pendants for Reversible Ambipolar Charging and Discharging

    Kenichi Oyaizu, Takashi Sukegawa, Hiroyuki Nishide

    CHEMISTRY LETTERS   40 ( 2 ) 184 - 185  2011.02  [Refereed]

     View Summary

    An electrode-attached layer of poly(phenylacetylene) bearing a pendant nitronyl nitroxide group per repeating unit, obtained by the Rh-catalyzed polymerization of 2-(4-ethynylphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl 3-oxide, underwent oxidation and reduction at 0.80 and 0.84 V vs. Ag/AgCl, respectively. The magnetically determined unpaired electron density of 92% was coulometrically reproduced, which supported the presumption that the radical survived during the course of the polymerization to allow both positive and negative charging of the pristine neutral polymer substantially per repeating unit. Galvanostatic Coulomb titration revealed the charge storage capability of the polymer, which demonstrated usefulness as organic electrode-active material with unprecedented ambipolar chargeability.

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  • POLYMERIZATION OF LACTIC O-CARBOXYLIC ANHYDRIDE USING ORGANOMETALLIC CATALYSTS

    Xiu-li Zhuang, Hai-yang Yu, Zhao-hui Tang, Kenichi Oyaizu, Hiroyuki Nishide, Xue-si Chen

    CHINESE JOURNAL OF POLYMER SCIENCE   29 ( 2 ) 197 - 202  2011.01  [Refereed]

     View Summary

    The ring-opening polymerization of 5-methyl-1,3-dioxolane-2,4-dione (lactic O-carboxylic anhydride, LacOCA) using organometallic complexes, including Co(III) complexes with Schiff base ligands, Tin(II) alphatates and Al(III) complexes with Schiff base ligands, was explored. The polymerization was carried out by treatment of the organometallic complexes with LacOCA in toluene under mild conditions. The corresponding poly(lactic acid) was characterized by spectroscopy and thermal analyses, which revealed insight into the structure of the effective catalyst for the polymerization of LacOCA.

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  • Luminescent Sensory Polymer Coating Composed of Platinumporphyrin and Poly(trimethylsilylpropyne) for Real-Time Oxygen Visualization in Operating PEFCs

    Tsuyoshi Hyakutake, Yuta Ishigami, Junji Kato, Junji Inukai, Kenji Miyatake, Hiroyuki Nishide, Masahiro Watanabe

    MACROMOLECULAR CHEMISTRY AND PHYSICS   212 ( 1 ) 42 - 47  2011.01  [Refereed]

     View Summary

    A luminescent PtTFP/PMSP polymer coating was prepared for the oxygen partial pressure visualization inside a PEFC. PMSP formed a smooth and tough coating as a highly oxygen-permeable matrix with a thickness of ca. 2 mu m in which the PtTFP was homogeneously dispersed. The coating displayed a strong red luminescence with significantly decreasing intensity upon increasing oxygen partial pressure. The sensitivity for the oxygen partial pressure was high and the analytical curve of the sensor polymer coating was undisturbed by external factors. The PtTFP/PMSP sensor was coated on the surface of a cathode gas diffusion layer on the air flow channel inside PEFC. The oxygen-pressure distribution in the air flow channel was successfully visualized while operating the PEFC.

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  • P- and n-type bipolar redox-active radical polymer: Toward totally organic polymer-based rechargeable devices with variable configuration

    Suga, T, Sugita, S, Ohshiro, H, Oyaizu, K, Nishide, H

    Advanced Materials   23 ( 6 ) 751 - 754  2011  [Refereed]

  • A supramolecular polymer of nitroxide radicals via hydrogen bonding

    Nakajima, S, Kato, E, Minatozaki, M, Nishide, H

    Macromolecular Symposia   304 ( 1 ) 1 - 4  2011  [Refereed]

  • Capsulation of carbon nanotubes on top of colloidally templated and electropolymerized polythiophene arrays

    Jin Young Park, Roderick Pernites, Nicel Estillore, Tsuyoshi Hyakutake, Ramakrishna Ponnapati, Brylee David Tiu, Hiroyuki Nishide, Rigoberto C. Advincula

    CHEMICAL COMMUNICATIONS   47 ( 31 ) 8871 - 8873  2011  [Refereed]

     View Summary

    We describe the capsulation of colloidally templated polythiophene (P3-TAA) arrays with multi-walled carbon nanotubes (MWNTs) after colloidal template electropolymerization. The dissolution of the polystyrene (PS) particle templates, which were assembled via the Langmuir-Blodgett (LB)-like technique, allowed the formation of hollow-shell Janus type arrays.

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  • Radical polymer-wrapped SWNTs at a molecular level: High-rate redox mediation through a percolation network for a transparent charge-storage material

    Choi, W, Ohtani, S, Oyaizu, K, Nishide, H, Geckeler, K.E

    Advanced Materials   23 ( 38 ) 4440 - 4443  2011  [Refereed]

  • Morphology-driven modulation of charge transport in radical/ion-containing, self-assembled block copolymer platform

    Suga, T, Takeuchi, S, Nishide, H

    Advanced Materials   23 ( 46 ) 5545 - 5549  2011  [Refereed]

  • Synthesis and Charge Transport Properties of Redox-Active Nitroxide Polyethers with Large Site Density

    Kenichi Oyaizu, Takeshi Kawamoto, Takeo Suga, Hiroyuki Nishide

    MACROMOLECULES   43 ( 24 ) 10382 - 10389  2010.12  [Refereed]

     View Summary

    To maximize the theoretical redox capacity of polymers containing cyclic nitroxides as redox active pendant groups for high density charge storage application, a compact five membered ring with the smallest equivalent weight among the robust cyclic nitroxides was directly bound to a poly(ethylene oxide) chain 2,2,5,5 Tetramethyl 3 oxiranyl-3-pyrrolin 1 oxyl was synthesized and polymerized via anionic coordinated ring-opening polymerization utilizing diethyl zinc/H2O as an initiator The unpaired electron in the monomer survived during the polymerization giving rise to a high density redox polymer with a weight-specific theoretical capacity of 147 mA h/g Cyclic voltammetry of the polymer layer confined at the surface of an electrode revealed a large redox capacity comparable to the theoretical capacity which was ascribed to the efficient swelling and yet insoluble properties of the polyether in electrolyte solutions by virtue of the high molecular weight of >10(5) and adhesive properties allowing immobilization of the layer on the electrode surface The redox capacity also indicated that the ionophoric polyether matrix accommodated electrolyte anions through the polymer/electrolyte interface to neutralize positive charges produced by the oxidation of the neutral radicals at the polymer/electrode interface The diffusion coefficient for the redox gradient driven charge hopping process corresponded to a large second order rate constant in the order of 10(7) M-1 s(-1), which suggested an efficient electron self-exchange reaction throughout the polymer layer due to the large redox site population and hence to the small intersite distance Test cells fabricated with a polymer/carbon fiber composite layer on an aluminum current collector as the cathode and a Li anode sandwiching an electrolyte layer were capable of charging and discharging as a secondary battery with an output voltage near 3 7 V and were durable for more than 10(3) charging discharging cycles without substantial degradation

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  • Synthesis of Amphiphilic Block Copolymers Bearing Stable Nitroxyl Radicals

    Xiuli Zhuang, Chunsheng Xiao, Kenichi Oyaizu, Natsuru Chikushi, Xuesi Chen, Hiroyuki Nishide

    JOURNAL OF POLYMER SCIENCE PART A-POLYMER CHEMISTRY   48 ( 23 ) 5404 - 5410  2010.12  [Refereed]

     View Summary

    We present here the synthesis of two kinds of amphiphilic block copolymers, a diblock copolymer MPEG-b-PTAm and a triblock copolymer MPEG-b-PLA-b-PTAm, which can self-assemble into micelles with nitroxyl radicals-containing PTAm segment in the core. The structure of the block copolymers was characterized by H-1 NMR and GPC. Dynamic laser light scattering and transmission electron microscopy were used to study the micellar behavior of the two block copolymers in aqueous solution. The micelles carrying nitroxyl radicals in the core can generate electron paramagnetic resonance, which is stable for a period of time up to 8 min even in the presence of reducing reagent such as ascorbic acid. The enhanced stability against the reducing agent was ascribed to the inaccessibility of the nitroxyl radical core placed in the interior of the micelles. Combined with the biocompatibility, these micelles were promising to be used as the EPR probes for bioimaging in vivo. (C) 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 5404-5410, 2010

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  • Poly(N-isopropylacrylamide) grafting on aluminium to actively switch its surface drag in water

    Tsuyoshi Hyakutake, Alexander V. Navrotskiy, Katsuaki Morita, Junji Kato, Hirotaka Sakaue, Ivan A. Novakov, Hiroyuki Nishide

    POLYMER INTERNATIONAL   59 ( 10 ) 1436 - 1440  2010.10  [Refereed]

     View Summary

    Active control of flow over object surfaces achieved by means of mechanical and/or electrical methods has recently been studied. However, there has been no report on actively switching the surface drag of an object by chemical modification of the object's surface. Poly(N-isopropylacrylamide) (PNIPA) was grafted onto the surface of an aluminium (Al) substrate via (A) surface-initiated atom transfer radical polymerization and (B) radical polymerization with an azo-group surface initiator. The grafting density was 0.19 and 0.15 chains nm(-2), respectively. The water contact angle of the PNIPA-grafted Al surface reversibly changed between 55 and 82 for (A) and between 42 degrees and 65 degrees for (B) at temperatures of 25 and 40 degrees C, which was ascribed to the temperature-responsive, hydrophilic-hydrophobic switching of the grafted PNIPA surface. The PNIPA grafting was applied on the surface of an ogive-shaped Al model. The normalized dropping speed of the model in water increased 1.1 times at 42 degrees C in comparison to that at 22 degrees C. Switching of the surface drag of PNIPA-grafted Al in water was demonstrated on the basis of the hydrophilicity and hydrophobicity of the grafted Al surface, the switching occurring with a change in temperature. (C) 2010 Society of Chemical Industry

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  • Biodegradable and Electroactive TEMPO-Substituted Acrylamide/Lactide Copolymers

    Xiuli Zhuang, Han Zhang, Natsuru Chikushi, Changwen Zhao, Kenichi Oyaizu, Xuesi Chen, Hiroyuki Nishide

    MACROMOLECULAR BIOSCIENCE   10 ( 10 ) 1203 - 1209  2010.10  [Refereed]

     View Summary

    Copolymers composed of PLA and PTAm were prepared by a macromonomer approach. The PLA bearing vinyl group at chain end was copolymerized with 2,2,6,6-tetrametylpiperidine-4-ylacrylamide. The resulted copolymers were oxidized by a peroxide to give PTAm-g-PLA. The structures of the copolymers were confirmed by NMR and FTIR spectroscopy. The comparison of (1)H NMR results and SQUID measurements demonstrated that the oxidation of the PTAm fragment proceeded almost to completion. An MTT assay, cell adhesion and spreading evaluation showed that the copolymers exhibited improved cytocompatibility as compared to the PTAm homopolymer due to the introduction of the biocompatible PLA moiety.

    DOI

  • Pt-porpholactone- and -porphyrin-based luminescent sensory polymer coating for visualization of oxygen pressure distribution on biplanar surface

    Wihatmoko Waskitoaji, Tsuyoshi Hyakutake, Masahiro Watanabe, Hiroyuki Nishide

    REACTIVE & FUNCTIONAL POLYMERS   70 ( 9 ) 669 - 673  2010.09  [Refereed]

     View Summary

    Luminescent oxygen-sensory polymer-coatings composed of platinum tetrakis(pentafluorophenyl)-porpholactone (PtPL) and -porphyrin (PtPP) with poly(trimethylsilylpropyne) (PMSP) were prepared for visualization of the oxygen partial pressure on two parallel planes or a biplanar surface. PMSP formed a smooth and tough coating as a high oxygen-permeable polymer matrix with a thickness of ca. 2 mu m, which homogeneously contained the luminescent dye probe. PtPL or PtPP. Under UV light (395 nm) irradiation, the coatings displayed strong magenta and red luminescence with maximum peaks at 750 and 650 nm ascribed to the PtPL and PtPP, respectively. The luminescence of the two coatings was efficiently quenched by oxygen which allowed the development of engineering curve to analyze the oxygen partial pressure. The luminescence intensities of the two coatings were separately monitored in order to allow the simultaneous measurement of the oxygen partial pressure distribution upon two planar surfaces. (C) 2010 Elsevier Ltd. All rights reserved.

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  • Fluorophilic cobalt phthalocyanine-containing Nafion membrane: high oxygen permeability and proton conductivity in the membrane

    Masami Shoji, Hiroyuki Nishide

    POLYMERS FOR ADVANCED TECHNOLOGIES   21 ( 9 ) 646 - 650  2010.09  [Refereed]

     View Summary

    A multiply-fluorinated cobalt phthalocyanine (CoFPC) was prepared, which could reversibly interact with oxygen. CoFPC was introduced into the hydrophobic perfluoroethylene-backbone domain of the Nafion membrane. The localization of CoFPC did not reduce the high proton conductivity (10(-2)-10(-3) Scm(-1)) ascribed to the hydrophilic channel of Nafion. The oxygen permeability through the CoFPC/Nafion membrane was higher than the nitrogen permeability and that of the pristine Nafion membrane, and was significantly enhanced at the lower upstream pressure. The permselectivity of oxygen versus nitrogen increased beyond 20 with the CoFPC content in the membrane. The CoFPC/Nafion membrane was coated on a glassy carbon modified with a Pt/C catalyst. The high electrochemical reduction current of oxygen suggested that the CoFPC/Nafion membrane efficiently supplied oxygen to the Pt/C catalyst. Copyright (C) 2009 John Wiley & Sons, Ltd.

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  • Comparative Study of the Self-Aggregation of Rhodamine 6G in the Presence of Poly(sodium 4-styrenesulfonate), Poly(N-phenylmaleimide-co-acrylic acid), Poly(styrene-alt-maleic acid), and Poly(sodium acrylate)

    Ignacio Moreno-Villoslada, Juan Pablo Fuenzalida, Gustavo Tripailaf, Rodrigo Araya-Hermosilla, Guadalupe del C. Pizarro, Oscar Guillermo Marambio, Hiroyuki Nishide

    JOURNAL OF PHYSICAL CHEMISTRY B   114 ( 37 ) 11983 - 11992  2010.09  [Refereed]

     View Summary

    The interaction between rhodamine 6G and different polyelectrolytes is analyzed. Structural aspects differentiate these polyelectrolytes, such as the presence of aromatic groups and the number and localization of their respective charges, which may be directly attached to the aromatic groups or to the polymeric main chain. In the case of poly(sodium acrylate), which does not bear aromatic groups, the polyelectrolyte induces cooperative self-stacking between the dyes which is highly sensitive to the ionic strength, due to the predominance of long-range electrostatic interactions between the polymer and the dye. In the case of poly(sodium 4-styrenesulfonate), whose charge is directly attached to the aromatic groups, a high dispersant ability of the dyes is found and the interaction is less dependent on the ionic strength, due to the predominance of short-range aromatic-aromatic interactions between the dye and the polymer. Among the two polyelectrolytes studied for which the polymeric charge is directly attached to the main chain, and separated from the aromatic group, poly(styrene-alt-maleic acid) shows a lower dependence of the interaction on the ionic strength than poly(N-phenylmaleimide-co-acrylic acid) at a comonomer composition of 1:2, due to a higher linear aromatic density and a lower linear charge density, indicating the importance of hydrophobic forces. Both copolymers exhibit a high ability to induce cooperative self-aggregation of the dye.

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  • Two-dimensionally extended organic high-spin poly(aminium cationic radical)s and their magnetic force microscopic images

    Tsuyoshi Michinobu, Jun Inui, Hiroyuki Nishide

    POLYMER JOURNAL   42 ( 7 ) 575 - 582  2010.07  [Refereed]

     View Summary

    Purely organic high-spin poly(aminium cationic radical)s of two-dimensionally extended soluble aromatic polyamines P1 and P2 were prepared by the palladium-catalyzed polycondensation of two multifunctional monomers, followed by chemical or electrochemical oxidations. The chemical structures of the precursor polyamines were fully characterized by (1)H-and (13)C nuclear magnetic resonance (NMR), infrared and MALDI-TOF mass spectra (MS). The aminium radical sites of N,N,N',N'-tetraaryl-p-phenylenediamines were connected through the m-phenylene ferromagnetic coupler, which satisfies the non-Kekule-type molecular design. Oxidation of radical sites was facilitated by electron-donating methoxy substituents. The first oxidation potential (E degrees'(1)) of P2 with methoxy substituents, evaluated from the cyclic voltammograms in CH(2)Cl(2), was 0.69 V (vs Ag/Ag(+)), whereas the E degrees'(1) of P1 without electron-donating substituents was 0.78 V. This result was further verified by spectroelectrochemistry measurements. The electrochemically oxidized P2 displayed a more intense low-energy band at ca. 800 nm ascribed to aminium cationic radicals and bications. Chemical oxidation of P1 and P2 with NOPF(6) solubilized with 18-crown-6 in CH(2)Cl(2) gave the corresponding poly(aminium cationic radical) s. The high-spin ground states were confirmed by the temperature dependence of forbidden electron spin resonance (ESR) transition peak intensities, and the average spin quantum number (S) determined by the magnetic curves reached 8.4/2 at low temperatures. Remarkably, when a small amount of trifluoroacetic acid was added, the half-life of polyradicals reached ca. 1 week at room temperature (RT). This result prompted us to observe the single polymer-based molecular and magnetic images by atomic force microscopy and magnetic force microscopy, respectively. The precursor polyamine P1 showed globular-shaped polymer particles with an average vertical distance of 1.43 nm. After chemical oxidation, the vertical distance of P1 definitely decreased, reflecting the improved p-type character of the nitrogen atoms. Moreover, the detection of weak MFM images supported the presence of magnetic spins in the single polymers. Polymer Journal (2010) 42, 575-582; doi:10.1038/pj.2010.47; published online 26 May 2010

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  • Improving Charge/Discharge Properties of Radical Polymer Electrodes Influenced Strongly by Current Collector/Carbon Fiber Interface

    Sunao Yoshihara, Hiroshi Isozumi, Masanori Kasai, Hisatomo Yonehara, Yuko Ando, Kenichi Oyaizu, Hiroyuki Nishide

    JOURNAL OF PHYSICAL CHEMISTRY B   114 ( 25 ) 8335 - 8340  2010.07  [Refereed]

     View Summary

    Charge/discharge processes of organic radical batteries based on the radical polymer's redox reaction are largely influenced by carbon fibers consisting in the composite electrodes to help electron transfer. To find the optimal structure of the composite electrodes, the dominant electron transfer processes were determined by ac impedance measurement of the composite electrodes. A strong correlation between the overall electron transfer resistance of the composite electrodes and the materials of the current collector suggests that the electric conduction to the current collector through the contact resistance should be crucial. It was also confirmed that the charge/discharge performance of the composite electrode was related to the overall electron transfer resistance of the composite electrode. These results indicated that the charge/discharge performance of the radical battery was dominated by the interfacial electron transfer processes at the current collector/carbon fiber interface and that the rate performance would be much improved by suitably designing the interfacial structure.

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  • Polyaromatic-Anion Behavior of Different Polyelectrolytes Containing Benzenecarboxylate Units

    Ignacio Moreno-Villoslada, Mario E. Flores, Oscar G. Marambio, Guadalupe del C. Pizarro, Hiroyuki Nishide

    JOURNAL OF PHYSICAL CHEMISTRY B   114 ( 23 ) 7753 - 7759  2010.06  [Refereed]

     View Summary

    The polyaromatic-ion behavior of poly(sodium N-maleoyl-2-aminobenzoate-co-sodium acrylate) in a comonomer composition 1:2, poly(sodium N-maleoyl-4-aminobenzoate-co-sodium acrylate) in a comonomer composition 1:2, and poly(sodium N-maleoyl-4-aminobenzoate-co-N,N-dimethylacrylamide) in a comonomer composition 1:1 is studied. The copolymers undergo short-range aromatic aromatic interactions with methylene blue and rhodamine B, as a consequence of which their UV vis monomer band is shifted to lower energies. As a result of their polyaromatic-anion behavior, methylene blue is easily dispersed on the polymeric domains. Moreover, the pK(a) of rhodamine B is shifted from 3.2 to 4.5-5 in the presence of these copolymers. This behavior is also observed in the presence poly(sodium 4-styrenesulfonate), but not in the presence of poly(sodium vinyl sulfonate), which are taken as reference polymers. Compared with poly(sodium 4-styrenesulfonate), a lower resistance to the cleaving effect of added NaCl on the interaction with methylene blue is found. A different influence on the reduction of 2,3,5-triphenyl-2H-tetrazolium chloride with ascorbic acid was found for the different polyelectrolytes.

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  • Nitroxide Radicals for Highly Efficient Redox Mediation in Dye-sensitized Solar Cells

    Fumiaki Kato, Naoki Hayashi, Takaya Murakami, Chie Okumura, Kenichi Oyaizu, Hiroyuki Nishide

    CHEMISTRY LETTERS   39 ( 5 ) 464 - 465  2010.05  [Refereed]

     View Summary

    A robust nitroxide radical, 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) and its 4-subsituted derivatives (R-TEMPO) exhibit electrochemically reversible redox properties with tunable half-wave potentials (E-1/2) based on the substituent effect. Dye-sensitized solar cells using R-TEMPO as mediators with electron-withdrawing R groups showed significantly enhanced photovoltages compared with those obtained using iodides. The linearity between the open-circuit voltage (V-oc) and E-1/2 revealed that V-oc dominated by the energy gap between the Fermi level of TiO2 and the SOMO level of R-TEMPO.

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  • Influence of the Linear Aromatic Density on Methylene Blue Aggregation around Polyanions Containing Sulfonate Groups

    Ignacio Moreno-Villoslada, Cesar Torres-Gallegos, Rodrigo Araya-Hermosilla, Hiroyuki Nishide

    JOURNAL OF PHYSICAL CHEMISTRY B   114 ( 12 ) 4151 - 4158  2010.04  [Refereed]

     View Summary

    The aggregation of methylene blue around different polyelectrolytes is studied by diafiltration, UV-vis, and (1)H NMR spectroscopies. Poly(sodium acrylate-co-sodium maleate) induces the formation of higher-order aggregates, showing a typical polyelectrolyte behavior dominated by long-range electrostatic interactions with the dye which are highly dependent on the ionic strength. Poly(sodium 4-styrenesulfonate) presents a high dispersant ability of methylene blue, showing what we can call a typical polyaromatic-anion behavior characterized by the presence of short-range aromatic-aromatic interactions with the dye which are less dependent on the ionic strength. An intermediate behavior is found for the copolymers poly(sodium 4-styrenesulfonate-co-sodium Maleate) at two different comonomer compositions, related to a different probability of the polymers to form and stabilize ion pairs in hydrophobic environments. Their behavior is a function of the linear aromatic density, which is related to the comonomeric Structure.

    DOI

  • Electronic Communication in the Formation of a Quartet Molecule 2,6,10-Tris[bis(p-methoxyphenyl)aminium]triphenylene

    Takeshi Ibe, Shu Kaiho, Kenichi Oyaizu, Hiroyuki Nishide

    CHEMISTRY LETTERS   39 ( 4 ) 356 - 357  2010.04  [Refereed]

     View Summary

    A quartet triradical molecule, 2,6,10-tris[bis(p-methoxyphenyl)aminium]triphenylene, was characterized by the electronic interaction among the three aminium sites based on the fused-aromatic, triphenylene-linked, and non-Kekule connectivity, which lead to the stable high-spin triradical formation.

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  • Synthesis and Electrochemistry of Schiff Base Cobalt(III) Complexes and Their Catalytic Activity for Copolymerization of Epoxide and Carbon Dioxide

    Xiuli Zhuang, Kenichi Oyaizu, Yongsheng Niu, Kenichiroh Koshika, Xuesi Chen, Hiroyuki Nishide

    MACROMOLECULAR CHEMISTRY AND PHYSICS   211 ( 6 ) 669 - 676  2010.03  [Refereed]

     View Summary

    A series of cobalt complexes with N,N,O,O-tetradentate Schiff base ligands were prepared. All the complexes were characterized by spectroscopy and electrochemical methods. An X-ray crystal structure analysis revealed that L-1-Co-III-dnp was monomeric with a six-coordinated central cobalt(III) atom in the solid state. The complexes were employed as catalysts for the alternating copolymerization of CO2 and racemic propylene oxide. End group analysis of the resulting polymer provided strong evidence for a monomer insertion mechanism for the propagation step. The catalytic activity was interpreted using the redox potential of cobalt(II/III) for the L-Co-III-dnp complexes, which offered a measure of the bond strength, or the degree of inertness of the axial ligand, to promote or suppress the monomer insertion.

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  • Different models on binding of aromatic counterions to polyelectrolytes

    Moreno-Villoslada, I, Torres-Gallegos, C, Araya-Hermosilla, R, Fuenzalida, J.P, Marambio, O.G, Pizarro, G.D.C, Flores, M.E, Murakami, T, Nishide, H

    Molecular Crystals and Liquid Crystals   522   136 - 147  2010  [Refereed]

  • Porphyrin-Dye Sensitized Solar Cell Utilizing Nitroxide Radical Mediator

    Takaya Murakami, Fumiaki Kato, Kenichi Oyaizu, Hiroyuki Nishide

    JOURNAL OF PHOTOPOLYMER SCIENCE AND TECHNOLOGY   23 ( 3 ) 353 - 355  2010  [Refereed]

  • Redox-active polyimide/carbon nanocomposite electrodes for reversible charge storage at negative potentials: expanding the functional horizon of polyimides

    Kenichi Oyaizu, Akihiko Hatemata, Wonsung Choi, Hiroyuki Nishide

    JOURNAL OF MATERIALS CHEMISTRY   20 ( 26 ) 5404 - 5410  2010  [Refereed]

     View Summary

    The reversible n-type charge-storage capability of polyimides was significantly enhanced in a polyimide/carbon nanocomposite prepared by cyclodehydration of the corresponding polyamic acid which was solution-processed into a composite layer on an electrode surface with a vapor-grown carbon nanofiber. The stepwise preparation process gave the first polyimide-based electrode-active material with a sufficient dispersion of the polyimide particles at the carbon nanofiber surface, while a simple grinding of the polyimide and the carbon nanofiber gave mixtures without charge retention capability due to gradual dissolution in the reduced state. The polyimide/carbon nanocomposites were characterized by negative redox potentials at -1.36 and -0.76 V vs. Ag/AgCl for poly(4,4'-oxydiphthalimido-1,4-phenylene) (1) and poly(pyromellitimido-1,4-phenylene) (2), respectively, which corresponded to a charging per repeating unit of the neutral polymers to radical polyanions. The 2/carbon nanocomposite underwent further reduction at -1.34 V to produce a dianion per repeating unit, giving rise to a high-density charging with a redox capacity of 185 mAh g(-1) based on the formula weight of 2. The typical redox capacity of the electrolyzed nanocomposites amounted to ca. 60% of the formula weight-based capacity, which was still larger than those of typical redox polymers with negative potentials, such as viologen-based polyelectrolytes. Additional advantages originated from the robustness of the polyimide framework, which allowed excellent charging/discharging cyclability. The polyimide/carbon nanocomposite electrodes would be highly promising as anode-active materials in organic rechargeable devices, owing to these excellent redox properties.

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  • Nanolithographic patterning via electrochemical oxidation of stable poly(nitroxide radical)s to poly(oxoammonium salt)s

    Tsuyoshi Hyakutake, Jin Young Park, Yasunori Yonekuta, Kenichi Oyaizu, Hiroyuki Nishide, Rigoberto Advincula

    JOURNAL OF MATERIALS CHEMISTRY   20 ( 43 ) 9616 - 9618  2010  [Refereed]

     View Summary

    Electrochemically oxidized patterns of stable poly(nitroxide radical)s at the nano-scale were demonstrated by controlling lithographic parameters, such as voltage, scan speed, and sweep duration.

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  • A TEMPO-substituted polyacrylamide as a new cathode material: an organic rechargeable device composed of polymer electrodes and aqueous electrolyte

    Kenichiroh Koshika, Natsuru Chikushi, Naoki Sano, Kenichi Oyaizu, Hiroyuki Nishide

    GREEN CHEMISTRY   12 ( 9 ) 1573 - 1575  2010  [Refereed]

     View Summary

    Poly(2,2,6,6-tetramethylpiperidinyloxy-4-yl acrylamide) was designed and synthesized as an electrode-active polymer for an organic rechargeable device containing an aqueous electrolyte. The device demonstrated a 1.2 V output voltage, exceeded 2000 charging-discharging cycles, and had a high charging rate performance within 1 min.

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  • Poly(vinylsulfonic acid)-grafted solid catalysts: new materials for acid-catalysed organic synthetic reactions

    Teruyuki Okayasu, Kei Saito, Hiroyuki Nishide, Milton T. W. Hearn

    GREEN CHEMISTRY   12 ( 11 ) 1981 - 1989  2010  [Refereed]

     View Summary

    The synthesis, characterisation and application of novel high-density poly(vinylsulfonic acid)-grafted solid acid catalysts are described. A graft, radical polymerization procedure was employed, allowing the immobilisation of the acid form of vinylsulfonic acid monomer onto various carrier materials, such as polystyrene, silica or polysaccharide-based gels. The highest acid-exchange capacity (as determined by acid-base titration methods) achieved with these new materials was 5.2 mmol H+ g(-1). The properties of these PVS-grafted materials as solid state acid catalysts have been examined from several perspectives, including their fundamental properties as materials with extremely high acid dissociation characteristics, their structural features as revealed from IR and solid-state NMR measurements, their thermal stability properties, and their surface morphologies, humidity dependencies and functionality. Compared to many other types of acid catalysts, these high-density poly(vinylsulfonic acid)-grafted materials demonstrated superior catalytic performance in esterification, Friedel-Crafts acylation, and condensation reactions. Moreover, these novel materials show high stability, significant anticorrosion capability and can be easily recycled.

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  • Nitroxide polymer networks formed by Michael addition: on site-cured electrode-active organic coating

    Takeshi Ibe, Rainer B. Frings, Artur Lachowicz, Soichi Kyo, Hiroyuki Nishide

    CHEMICAL COMMUNICATIONS   46 ( 20 ) 3475 - 3477  2010  [Refereed]

     View Summary

    Highly and homogeneously crosslinked poly(beta-ketoester) networks densely bearing robust nitroxide radicals were prepared via a click-type and stepwise Michael polyaddition. A half-battery cell composed of the thermally-cured radical network coatings displayed a rapid, reversible, and almost stoichiometric redox-activity even with a thickness of ca. 10 mu m, which may be applicable as the electrode of organic-based rechargeable devices.

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  • Synthesis of Poly(oxoammonium salt)s and Their Electrical Properties in the Organic Thin Film Device

    Takeo Suga, Shunya Takeuchi, Takanori Ozaki, Miki Sakata, Kenichi Oyaizu, Hiroyuki Nishide

    CHEMISTRY LETTERS   38 ( 12 ) 1160 - 1161  2009.12  [Refereed]

     View Summary

    Two redox-active poly(oxoammonium salt)s were synthesized via chemical oxidation of a TEMPO-substituted polymer, or conventional radical polymerization of the oxoammonium monomer, respectively. The diode-structured thin film device composed of poly(oxoammonium salt) with radical conc. of 6-43% exhibited a resistive switching behavior (ON-OFF ratio > 10(3)), in contrast to the radical-free poly(oxoammonium salt), which revealed that the coexistence of radical/oxoammonium salts contributed to a significant change in I-V characteristics.

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  • Biplanar Visualization of Oxygen Pressure by Sensory Coatings of Luminescent Pt-Porpholactone and -Porphyrin Polymers

    Wihatmoko Waskitoaji, Tsuyoshi Hyakutake, Junji Kato, Masahiro Watanabe, Hiroyuki Nishide

    CHEMISTRY LETTERS   38 ( 12 ) 1164 - 1165  2009.12  [Refereed]

     View Summary

    Luminescent oxygen sensory polymer coatings composed of platinum tetrakis(pentafluorophenyl)porpholactone and -porphyrin with poly(trimethylsilylpropyne) were prepared. Two luminescence peaks at 750 and 650 nm from the coating ascribed to the porpholactone and the porphyrin, respectively, were efficiently quenched with oxygen and were separately monitored to allow the simultaneous measurement of oxygen partial pressure distribution upon two planar surfaces.

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  • Comment on "J- and H-Aggregates of 5,10,15,20-Tetrakis-(4-sulfonatophenyl)-porphyrin and Interconversion in PEG-b-P4VP Micelles"

    Ignacio Moreno-Villoslada, Takaya Murakami, Hiroyuki Nishide

    BIOMACROMOLECULES   10 ( 12 ) 3341 - 3342  2009.12  [Refereed]

    DOI

  • Environmentally benign batteries based on organic radical polymers

    Hiroyuki Nishide, Kenichiroh Koshika, Kenichi Oyaizu

    PURE AND APPLIED CHEMISTRY   81 ( 11 ) 1961 - 1970  2009.11  [Refereed]

     View Summary

    A radical polymer is an aliphatic organic polymer bearing densely populated unpaired electrons in the pendant robust radical groups per repeating unit. These radicals' unpaired electrons are characterized by very fast electron-transfer reactivity, allowing reversible charging as the electrode-active materials for secondary batteries. Organic-based radical batteries have several advantages over conventional batteries, such as increased safety, adaptability to wet fabrication processes, easy disposability, and capability of fabrication from less-limited resources, which are described along the fashion of green chemistry.

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  • An Aqueous, Electrolyte-Type, Rechargeable Device Utilizing a Hydrophilic Radical Polymer-Cathode

    Kenichiroh Koshika, Naoki Sano, Kenichi Oyaizu, Hiroyuki Nishide

    MACROMOLECULAR CHEMISTRY AND PHYSICS   210 ( 22 ) 1989 - 1995  2009.11  [Refereed]

     View Summary

    A hydrophilic poly(vinyl ether)-backbone polymer bearing a pendant TEMPO radical, poly(2,2,6,6-tetramethylpiperidinyloxy-4-yl vinyl ether) (PTVE), was designed as a cathode-active material, which displays a reversible one-electron redox capability, even in an aqueous electrolyte. The PTVE layer coated on a current collector demonstrated a rapid charging-discharging rate based on the combination of the redox-active nitroxide radicals built into the hydrophilic polymer and the aqueous electrolyte that possessed a high electrical conductivity. A test cell fabricated with a PTVE cathode, a zinc anode, and an aqueous electrolyte gave an output voltage of 1.7 V and showed the ability to be recharged more than 500 times rechargeability.

    DOI

  • Two-Dimensionally Extended Aromatic Polyamines for Optimization of Charge-Transporting Properties by Partial Oxidation

    Tsuyoshi Michinobu, Fumiaki Kato, Jun Inui, Hiroyuki Nishide

    JOURNAL OF POLYMER SCIENCE PART A-POLYMER CHEMISTRY   47 ( 18 ) 4577 - 4586  2009.09  [Refereed]

     View Summary

    This article describes the synthesis of the two-dimensionally extended aromatic polyamines by polycondensation between the tri-sec-amine monomer and p-phenylenediamine-based dibromide, the polyradical generation by chemical and electrochemical oxidations, and the hole-transporting properties. The molecular weights (M(n)) of the polyamines, 3a and 3b, were 7700 and 5000, respectively, and both polymers were very soluble in the typical organic solvents, ensuring a good film formation capability by a spin-coating technique. The thermal stability of the aromatic polyamines, elucidated by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC), was quite high. More important, the cross-conjugated structure is essential for the controlled radical generation and the maintenance of the radical stability. Cyclic voltammograms of the neutral polyamines in the presence of 1 vol % of trifluoroacetic acid and the intervalence bands of the partially oxidized polyamines with NOPF(6) revealed that the generated radicals delocalize over the p-phenylenediamine moieties. The half-life of the polyradicals was about 12 h even under ambient conditions, which allowed us to fabricate and measure the hole-only devices. The charge-tran sporting properties of the polyamines were dramatically changed by the partial oxidation (20 mol %/aminium unit) with NOPF(6). The neutral polyamines showed the conventional injection-limit behaviors, whereas the hole-transporting behaviors of the polyradicals are bulk-limit and highly dependent on the chemical structure. The efficient hole-transport of the all-conjugated poly(aminium cationic radical)s was for the first time realized for the polyradical of 3b. (C) 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 4577-4586, 2009

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  • Control of CI Basic Violet 10 aggregation in aqueous solution by the use of poly(sodium 4-styrenesulfonate)

    Ignacio Moreno-Villoslada, Felipe Gonzalez, Luis Arias, Jose Miguel Villatoro, Ricardo Ugarte, Susan Hess, Hiroyuki Nishide

    DYES AND PIGMENTS   82 ( 3 ) 401 - 408  2009.09  [Refereed]

     View Summary

    The aggregation behavior of C.I. Basic Violet 10 in the presence of poly(sodium 4-styrenesulfonate) was modified, as a consequence of short-range interactions. In aqueous acidic media, the cationic dye forms hydrophobic ion pairs with polymeric benzene sulfonate groups which tend to aggregate in H-contacts, this tendency being readily influenced by the relative concentration of the macromolecule with respect to that of the dye. In the case of dilute aqueous dye solutions (<= 10(-4) M), for which the probability of dye self-aggregation is small, C.I. Basic Violet 10 self-contacts are forced in the presence of a moderate excess of poly(sodium 4-styrenesulfonate). At dye concentrations > 10(-4) M, for which the probability of dye self-aggregation increases, dye-dye contacts are minimized in the presence of a large excess of the polymer. Hence, the luminescence of dye solutions can be tuned insorar as, that of dilute dye solutions is quenched whilst that of concentrated dye solutions can be enhanced. This behavior was not observed for other polyelectrolytes such as poly(sodium vinylsulfonate), or the more hydrophobic poly(sodium 2-(N-acrylamido)-2-methyl-propanesulfonate). (C) 2009 Elsevier Ltd. All rights reserved.

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  • Luminescent Multi-Layered Polymer Coating for the Simultaneous Detection of Oxygen Pressure and Temperature

    Tsuyoshi Hyakutake, Hiroyuki Taguchi, Junji Kato, Hiroyuki Nishide, Masahiro Watanabe

    MACROMOLECULAR CHEMISTRY AND PHYSICS   210 ( 15 ) 1230 - 1234  2009.08  [Refereed]

     View Summary

    A triple-layered luminescent polymer coating was prepared to simultaneously detect both oxygen and temperature upon the coating. The coating was composed of an oxygen and a temperature sensory layer based on platinumporphyrin (PtTFP) and ruthenium phenanthroline (Ru(phen)) dye molecule, respectively. The temperature-sensitive Ru(phen) was dispersed in gas-barrier polyvinyl alcohol as the first layer, which was further coated with a water-proofing fluorine-containing polymer. The oxygen sensory layer composed of the oxygen-sensitive PtTFP and high oxygen-permeative poly(1-trimethylsilyl-1-propyne) was coated as the third layer. The two luminescences were separately monitored: the oxygen partial pressure and temperature in the range of 0-21 kPa and of 25-120 degrees C were successfully detected.

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  • Binding of Methylene Blue to Polyelectrolytes Containing Sulfonate Groups

    Ignacio Moreno-Villoslada, Cristian Torres, Felipe Gonzalez, Toshimichi Shibue, Hiroyuki Nishide

    MACROMOLECULAR CHEMISTRY AND PHYSICS   210 ( 13-14 ) 1167 - 1175  2009.07  [Refereed]

     View Summary

    The interaction between methylene blue (MB) and poly(sodium 4-styrenesulfonate) (PSS), poly(sodium vinylsulfonate) (PVS), and the more hydrophobic poly[sodium 2-(N-acrylamido)2-methyl-propanesulfonate] (PAMPS), is investigated. The main driving forces for the interaction with PSS are supposed to be short-range aromatic/aromatic interactions, which explain the smaller dissociation constant, the resistance to the cleaving effect of NaCl, and the prevention of MB self-aggregation around the macromolecules under a moderate excess of the polymer. On the contrary, as a consequence of long-range interactions, a higher local concentration of MB around PAMPS and, more significantly, around PVS results in MB self-aggreation that can be g quenched in the presence of NaCl.

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  • Radical Polymers for Organic Electronic Devices: A Radical Departure from Conjugated Polymers?

    Kenichi Oyaizu, Hiroyuki Nishide

    ADVANCED MATERIALS   21 ( 22 ) 2339 - 2344  2009.06  [Refereed]

     View Summary

    Radical polymers are aliphatic or nonconjugated polymers bearing organic robust radicals as pendant groups per repeating unit. A large population of the radical redox sites allows the efficient redox gradient-driven electron transport through the polymer layer by outer-sphere self-exchange reactions in electrolyte solutions. The radical polymers are emerging as a new class of electroactive materials useful for various kinds of wet-type energy storage, transport, and conversion devices. Electric-field-driven charge transport by hopping between the densely populated radical sites is also a remarkable aspect of the radical polymers in the solid state, which leads to many dry-type devices such as organic memories, diodes, and switches.

    DOI

  • Chiral alkylated poly(m-phenylene)s: Optical activity and thermal stability of helical structures

    Risa Sone, Ichiro Takemura, Kenichi Oyaizu, Hiroyuki Nishide

    SYNTHETIC METALS   159 ( 9-10 ) 925 - 930  2009.05  [Refereed]

     View Summary

    Chiral poly[4,6-bis(alkylthio)-1,3-phenylene-alt-2-methyl-1,3-phenylene] was synthesized from 1,3-dibromo-2,6-bis(3-dodecyl-2-methylthio)benzene and 2-methyl-1,3-phenylenebis(pinacol borate) as a precursor of chiral poly(thiaheterohelicene). Circular dichroism (CD) spectra that arise from the poly(1,3-phenylene) backbone inverted according to the chirality of the side chains, which indicated that a helical conformation of the polymer was induced by the interaction between the side chains. The CD intensity of the polymer increased in non-polar solvents such as hexane. The decrease in the molar CD intensity and the broadening of a fluorescence band at higher concentrations Suggested that the aggregation of the polymer Suppressed the formation of the helical structure. The conformational changes were monitored by the CD and the (1)H NMR spectra at different temperatures. In a good solvent Such as dichloromethane, the CD intensity increased, and the (1)H NMR signal of benzene protons shifted to lower fields at low temperatures. In hexane. the CD spectra and the I H NMR signals were less dependent on temperatures, as a result of the strong interaction between the chiral alkyl chains in the polymer to freeze the helical conformation. (C) 2009 Elsevier B.V. All rights reserved.

    DOI

  • 2,6,10-Tris(bithiophenyl)triphenylene: Synthesis and high-spin alignment in its p-doped radical derivative

    Takeshi Ibe, Hiroaki Umeda, Hiroyuki Nishide

    SYNTHETIC METALS   159 ( 9-10 ) 788 - 791  2009.05  [Refereed]

     View Summary

    2,6,10-Tris[5'-(5-hexyloxyphenyl-2,2'-bithiophenyl)]-3,7,11-tris(hexyloxy)tripheneylene (2) was designed and synthesized as a pi-conjugated platform to produce its tris(cationic radical) derivative (1) in a non-Kekule and nondisjoint fashion. An electrochemical study revealed the chemically reversible redox property of 2. Gaseous antimony pentachloride-doping of 2 dispersed in a polystyrene matrix gave its cationic radical. It was chemically stable with a half-life >2 weeks and displayed a triplet ground state based on an ESR measurement. A high-spin state with S=3/2 for 1 was proved by the magnetization and magnetic susceptibility. (C) 2009 Elsevier B.V. All rights reserved.

    DOI

  • Microphase-Separated Poly(vinylpyridine) Block Copolymer Prepared with a Novel Bifunctional Initiator

    Masami Shoji, Masao Eguchi, John M. Layman, Matthew P. Cashion, Timothy E. Long, Hiroyuki Nishide

    MACROMOLECULAR CHEMISTRY AND PHYSICS   210 ( 7 ) 579 - 584  2009.04  [Refereed]

     View Summary

    A vinylpyridine block copolymer was prepared by stepwise controlled/living radical polymerization with a novel bifunctional initiator, 4-(2-bromopropanoyloxy)-N-(p-methylbenzyloxy)-2,2,6,6-tetramethylpiperidine. The initiator was synthesized in a facile manner using commercially available p-xylene and 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl (4-hydroxy TEMPO). Through stepwise atom transfer radical polymerization (ATRP) of methyl methacrylate (MMA) and nitroxide-mediated radical polymerization (NMRP) of 4-vinylpyridine (4VP), the PMMA-b-P4VP copolymer was prepared with a wide range of the copolymer compositions. Microphase-separation was demonstrated in cross sectional TEM images of self-standing block copolymer membranes.

    DOI

  • Coupling Reaction on Gold Nanoparticle to Yield Polythiophene/Gold Nanoparticle Alternate Network Film

    Manabu Tanaka, Remi Fujita, Hiroyuki Nishide

    JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY   9 ( 1 ) 634 - 639  2009.01  [Refereed]

     View Summary

    The novel gold nanoparticle, which was stabilized with pi-conjugated molecules bearing functional groups at the terminals, was prepared via conventional procedure by using 5-bromo-2,2'-bithiophene-5'-thiol as a stabilizer. The gold nanoparticle (ca. 3 nm-diameter) showed good dispersion stability in various organic solvents, and its electrochemical and spectroscopic study revealed peculiar properties originated in the pi-conjugated molecular stabilizer, bithiophene derivative. The Pd-catalyzed coupling reaction on the gold nanoparticle was first achieved by using the gold nanoparticle bearing bromo groups at the particle surface and the model boronic acid molecule, 5-formyl-2-thiopheneboronic acid, to yield the terthiophene derivatives on the gold nanoparticle. The (1)H-NMR, UV, and TGA analysis supported the progress of the coupling reaction on the gold nanoparticle. This Pd-catalyzed coupling reaction was applied with the borate-terminated polythiophene to form polythiophene/gold nanoparticle alternate network film. The electron microscopic images supported the formation of the network structure. The high electric conductivity on the network film suggested that the conductive characteristic of the film originated from that of the pi-conjugated polythiophene backbone connected with the gold nanoparticle.

    DOI

  • A rechargeable battery based on hydrophilic radical polymer electrode and its green assessment

    K. Koshika, M. Kitajima, K. Oyaizu, H. Nishide

    GREEN CHEMISTRY LETTERS AND REVIEWS   2 ( 3 ) 169 - 174  2009  [Refereed]

     View Summary

    A hydrophilic radical polymer electrode-based rechargeable battery was designed along the concept of green chemistry. A hydrophilic radical polymer, poly(2,2,6,6-tetramethylpiperidinyloxy-4-yl vinylether), was synthesized as an electrode-active material; its battery demonstrated a high charging-discharging rate and long cycle life. The combination of the hydrophilic polymer electrode and an aqueous electrolyte for the battery fabrication was expected to provide safety improvements such as a low ignition risk besides the high battery performance. The green characteristics were studied using the "i-Messe," an evaluation method proposed by the committee of the Green Sustainable Chemistry Network, Japan. The electrode-active polymer was evaluated for substantial improvements in disaster safety and health safety.

    DOI

  • An ultrafast chargeable polymer electrode based on the combination of nitroxide radical and aqueous electrolyte

    Kenichiroh Koshika, Naoki Sano, Kenichi Oyaizu, Hiroyuki Nishide

    CHEMICAL COMMUNICATIONS   ( 7 ) 836 - 838  2009  [Refereed]

     View Summary

    A film of poly( 2,2,6,6-tetramethylpiperidinyloxy-4-yl vinylether) coated on a current collector displayed a rapid and reversible electrochemical response in aqueous electrolytes, and allowed an ultrafast full charging of 3 mC cm(-2) in as short as 3 seconds by virtue of the combination of the hydrophilic radical polymer and the aqueous electrolyte possessing a high electrical conductivity.

    DOI

  • Preparation of a novel poly(vinylsulfonic acid)-grafted solid phase acid catalyst and its use in esterification reactions

    Teruyuki Okayasu, Kei Saito, Hiroyuki Nishide, Milton T. W. Hearn

    CHEMICAL COMMUNICATIONS   ( 31 ) 4708 - 4710  2009  [Refereed]

     View Summary

    A high-density sulfonic acid polymer, grafted onto a carrier surface, was synthesized from the acid form of vinylsulfonic acid monomer, and its catalytic activity as a new class of heterogeneous acid catalyst demonstrated in esterification reactions.

    DOI

  • Redox-active nitroxide radical polymers: From green catalysts to energy storage devices

    Waskitoaji, W, Suga, T, Nishide, H

    AIP Conference Proceedings   1169   13 - 18  2009  [Refereed]

  • Emerging n-type redox-active radical polymer for a totally organic polymer-based rechargeable battery

    Suga, T, Ohshiro, H, Ugita, S, Oyaizu, K, Nishide, H

    Advanced Materials   21 ( 16 ) 1627 - 1630  2009  [Refereed]

  • Facilitated oxygen transport through a Nafion membrane containing cobaltporphyrin as a fixed oxygen carrier

    Masami Shoji, Kenichi Oyaizu, Hiroyuki Nishide

    POLYMER   49 ( 26 ) 5659 - 5664  2008.12  [Refereed]

     View Summary

    A Nafion membrane containing a cobaltporphyrin (CoP) complex as a fixed oxygen carrier was prepared with a view to facilitate oxygen transport through the membrane. The design concept of the CoP-loaded Nafion membrane was based on the CoP's modification to place the CoP complex in a hydrophobic domain of the microphase-separated structure, in order to facilitate the oxygen transport and to maintain proton conductivity. The oxygen permeability through the CoP-loaded Nafion membrane was higher than the nitrogen permeability, and significantly enhanced at relatively-low oxygen pressures of the upstream, indicating that the fixed Col? complex acted as an oxygen hopping site to facilitate the oxygen transport. The oxygen/nitrogen permselectivity increased with the content of CoP in the Nafion membrane. Electrochemical reduction of oxygen at a glassy carbon electrode, modified with a Pt/C catalyst and the CoP-loaded Nafion membrane, provided additional support for the facilitated oxygen transport by the membrane. Increased current for the reduction of oxygen on the modified electrode by loading CoP indicated that the CoP offered the oxygen hopping site in the Nafion membrane. (c) 2008 Elsevier Ltd. All rights reserved.

    DOI

  • Polypyridylpropyne-Pd and -Pt porphyrin coating for visualization of oxygen pressure

    Tsuyoshi Hyakutake, Hiroyuki Taguchi, Hirotaka Sakaue, Hiroyuki Nishide

    POLYMERS FOR ADVANCED TECHNOLOGIES   19 ( 9 ) 1262 - 1269  2008.09  [Refereed]

     View Summary

    Poly[1-trimethylsilyl-1-propyne-co-1-(3-pyridyl)propyne] 1 was prepared both as a polymer-ligand of a palladium porphyrin (PdOEP) and of a platinum porphyrin (PtTFP) and as a highly gas-permeable polymer matrix of the porphyrin. The porphyrin acted as a phosphorescence probe which could be quenched with oxygen and sense the oxygen partial pressure. 1 gave a smooth and tough coating with a thickness of ca. 2 mu m which homogeneously involved the porphyrin. The porphyrin-1 coatings displayed strong red-colored phosphorescences (the emission maximum at 670 and 650nm for PdOEP and PtTFP, respectively), and their intensity significantly decreased with an increase in the oxygen partial pressure on the coating. The high oxygen-quenching efficiency or the high oxygen pressure sensitivity of the porphyrin's phosphorescence was observed even at cryogenic temperature. Aggregation of the porphyrin was suppressed in the coating by ligation of the porphyrin with the nitrogenous residue of 1 to significantly reduce spatial noise in the phosphorescence measurement or the oxygen-pressure sensing. PtTFP-1 was coated on the surface of a delta wing model. The oxygen-pressure distribution on the coated model was successfully visualized in a cryogenic wind tunnel test. Copyright (C) 2008 John Wiley & Sons, Ltd.

    DOI

  • Synthesis and characterization of radical-bearing polyethers as an electrode-active material for organic secondary batteries

    Kenichi Oyaizu, Takeo Suga, Kentaro Yoshimura, Hiroyuki Nishide

    MACROMOLECULES   41 ( 18 ) 6646 - 6652  2008.09  [Refereed]

     View Summary

    In search of polymer backbones to bind organic radical pendant groups as redox centers for high-density charge storage application, polyether was employed as a flexible chain with a low glass transition temperature and affinity to electrolyte solutions. Cyclic ethers bearing nitroxide radicals were synthesized and polymerized via ring-opening polymerization utilizing various initiators. Polyethers bearing robust radical substituents such as 2,2,6,6-tetramethylpiperidin-l-oxyl-4-yl and 2,2,5,5-tetramethyl-2,5-dihydro-1H-pyrrol-l-oxyl-3-yl groups with high density, i.e., per repeating unit with small equivalent weights, were prepared by the anionic polymerization of the corresponding epoxides. Cyclic voltammetry of the radical polyethers, obtained for polymer/carbon composites confined at an aluminum current collector, revealed large redox capacities comparable to the formula weight-based theoretical values, which was ascribed to the efficient swelling and yet insoluble properties of the polyethers in electrolyte solutions by virtue of their high molecular weights and adhesive properties to be held on electrode surfaces. The redox capacity also indicated that the ionophoric polyether matrix accommodated electrolyte anions to compensate positive charges produced by the oxidation of the neutral radicals at the polymer/electrode interface, allowing charge propagation deep into the polymer layer by a site-hopping mechanism. Test cells fabricated with the polymer/carbon composite as the cathode and a Li anode, sandwiching an electrolyte layer, performed as a secondary battery at output voltages near 3.6 V without substantial degradation even after 100 charging-discharging cycles.

    DOI

  • Stacking of 2,3,5-triphenyl-2H-tetrazolium chloride onto polyelectrolytes containing 4-styrenesulfonate groups

    Ignacio Moreno-Villoslada, Cristian Torres, Felipe Gonzalez, Marcos Soto, Hiroyuki Nishide

    JOURNAL OF PHYSICAL CHEMISTRY B   112 ( 36 ) 11244 - 11249  2008.09  [Refereed]

     View Summary

    Possible structural aspects are discussed that justify the different resistance to reduction of 2,3,5-triphenyl-2H-tetrazolium chloride (TTC) both chemically (by reaction with ascorbic acid (ASC)) and electrochemically, in the presence of different polyelectrolytes Such as poly(sodium 4-styi-enesulfonate) (PSS), poly(sodium 4-styrenesulfonate-co-sodium maleate) at two different comonomer compositions (P(SS1-co-MA(1)) and P(SS3-co-MA(1))), and poly(sodium acrylate-co-sodium maleate) (P(AA1-co-MA(1))). Different dissociation constants are found for the complexes between TTC and the different polyelectrolytes by diafiltration (DIF). Related to this, spectroscopical differences are also found by H-1 NMR and UV-vis spectroscopies. Dynamic light scattering (DLS) showed a higher tendency to undergo intermolecular aggregation for P(SS1-co-MA(1)) in the presence of TTC, a result that could be related with a higher tendency for TTC to form hydrophobic ion pairs as a consequence of single stacking with the benzene sulfonate groups (BS) of this polyelectrolyte. On the other hand. the lower tendency for PSS to undergo intermolecular aggregation could be attributable to a higher probability to form more hydrophilic adducts by means of double stacking with TTC.

    DOI

  • Poly(thiaheterohelicene) derived from the long-alkylated polysulfonium precursor

    Ichiro Takemura, Risa Sone, Hiroyuki Nishide

    POLYMERS FOR ADVANCED TECHNOLOGIES   19 ( 8 ) 1092 - 1096  2008.08  [Refereed]

     View Summary

    Poly[4,6-bis(dodecylthio)-1,3-phenylene-alt-2-methyl-1,3-phenylene] (Poly-S) was synthesized via Suzuki-Miyaura coupling of 1,3-dibromo-2,6-bis(dodecylthio)benzene and 2-methyl-1,3-phenylenebis(pinacol borate). After quantitative oxidation of the pendant sulfide moiety to the sulfoxide derivative (Poly-SO), the m-linked benzene rings were fused via intramolecular ring-closing condensation with excess triflic acid to form the corresponding poly(sulfonium cation) (Poly-S+) with a helical structure. Poly-S+ was quite soluble in non-polar solvents due to the long alkyl dodecyl chain. The Poly-S+ film, especially the film cast from its acetone solution, gave a polarized optical micrograph, suggesting an oriented structure of the helical poly(sulfonium) derivative. The X-ray diffraction pattern of the film supported a hexagonal columnar packing of the polymer. The polysulfonium derivative in the film state was converted to the corresponding poly(thiaheterohelicene) (Poly-TH) via the dealkylation with a basic potassium hydroxide methanol solution or pyridine. The Poly-TH film was doped with iodine. Its conductivity was enhanced about 30 times when compared to that of the undoped film. Copyright (C) 2008 John Wiley & Sons, Ltd.

    DOI

  • Reduction of 2,3,5-triphenyl-2H-tetrazolium chloride in the presence of polyelectrolytes containing 4-styrenesulfonate moieties

    Ignacio Moreno-Villoslada, Marcos Soto, Felipe Gonzalez, Francisco Montero-Silva, Susan Hess, Ichiro Takemura, Kenichi Oyaizu, Hiroyuki Nishide

    JOURNAL OF PHYSICAL CHEMISTRY B   112 ( 17 ) 5350 - 5354  2008.05  [Refereed]

     View Summary

    The redox behavior of 2,3,5-triphenyl-2H-tetrazolium chloride (TTC) in the presence of different polyelectrolytes such as poly(sodium 4-styrenesulfonate) (PSS), poly(sodium 4-styrenesulfonate-co-sodium maleate) at two different comonomer compositions (P(SS1-co-MA(1)) and P(SS3-co-MA(1))), poly(sodium acrylate-co-sodium maleate) (P(AA(1)-co-MA(1))), and poly(sodium acrylate) (PAA) is studied. Due to aromatic-aromatic interactions, the polyelectrolytes containing benzene sulfonate groups produce a decrease on the reduction rate of TTC in the presence of ascorbic acid (ASC) and a shift of the anodic and cathodic peaks to higher negative potentials for the electrochemical reaction of TTC. As an important conclusion, these effects are a function of the linear aromatic density of the polyelectrolytes.

    DOI

  • A non-volatile, bistable, and rewritable memory device fabricated with poly(nitroxide radical) and silver salt layers

    Yasunori Yonekuta, Kenji Honda, Hiroyuki Nishide

    POLYMERS FOR ADVANCED TECHNOLOGIES   19 ( 4 ) 281 - 284  2008.04  [Refereed]

     View Summary

    A non-volatile, bistable, and rewritable organic memory device was successfully fabricated with the layers of poly(2,2,6,6-tetramethylpiperidine-1-oxyl methacrylate) (PTMA) and poly(methyl methacrylate) (PMMA) containing silver salt. The PTMA layer was employed as a p-dopable material, while the silver salt-dispersed PMMA layer acted as an n-dopable material. The ON-OFF ratio between low-conductivity and high-conductivity states amounted to more than four orders of magnitude, and the retention time was longer than 10(3) sec. The device was characterized by excellent rewritability. Copyright (C) 2007 John Wiley & Sons, Ltd.

    DOI

  • In situ and real-time visualisation of oxygen distribution in DMFC using a porphyrin dye compound

    Junji Inukai, Kenji Miyatake, Yuta Ishigami, Masahiro Watanabe, Tsuyoshi Hyakutake, Hiroyuki Nishide, Yuzo Nagumo, Masayuki Watanabe, Akira Tanaka

    CHEMICAL COMMUNICATIONS   ( 15 ) 1750 - 1752  2008.04  [Refereed]

     View Summary

    A luminescent porphyrin dye film has been coated onto a transparent separator on the cathode side of a direct methanol fuel cell (DMFC) to visualise clearly oxygen distribution under operating conditions by analysing emission from the dye.

    DOI

  • Toward flexible batteries

    Nishide, H, Oyaizu, K

    Science   319 ( 5864 ) 737 - 738  2008  [Refereed]

  • Totally Organic Polymer-Based Electrochromic Cell Using TEMPO-Substituted Polynorbornene as a Counter Electrode-Active Material

    Yusuke Takahashi, Naoki Hayashi, Kenichi Oyaizu, Kenji Honda, Hiroyuki Nishide

    POLYMER JOURNAL   40 ( 8 ) 763 - 767  2008  [Refereed]

     View Summary

    An electrochromic (EC) cell using a viologen-based polymer as an EC material and a radical polymer bearing a redox-active 2,2,6,6-tetramethylpiperidin-N-oxyl (TEMPO) group per repeating unit as a counter electroactive material was fabricated. The radical polymer was spin-coated on an ITO/glass electrode as the counter electrode of the EC cell. The electrochromic material of the cell was a polyion complex consisted of poly(decyl viologen) and poly(styrene sulfonate) (PV 10-PSS), which was also spin-coated on the ITO/glass. An ion-conducting polymer gel Solution was sandwiched between the two electrodes. Electrochemical switching of the cell was monitored using the visible absorption of the PV 10-PSS complex (lambda(max) = 550 nm) that appeared in the reduced state, while the radical polymer was transparent in the visible region in both redox states. PV 10-PSS and the radical polymer were Concurrently reduced and oxidized, respectively, on each electrode during the charging process, which corresponded to the coloration of the cell. The decoloration of the polyion complex was effected by a discharging process under short circuit conditions. The electrochromic behavior of the cell was characterized by a remarkably low driving voltage, as a result of a small potential gap between PV 10-PSS and the radical polymer. The use of the organic redox polymers, not only for the low energy-driven electrochromic switching but also for the charge-storage purposes, allowed a universal design of a battery-like display device, with possible application to a flexible and totally organic electrochromic cell.

    DOI

  • Nernstian adsorbate-like bulk layer of organic radical polymers for high-density charge storage purposes

    Oyaizu, K, Ando, Y, Konishi, H, Nishide, H

    Journal of the American Chemical Society   130 ( 44 ) 14459 - 14461  2008  [Refereed]

  • Dual-mode oxygen-sensing based on oxygen-adduct formation at cobaltporphyrin-polymer and luminescence quenching of pyrene: an optical oxygen sensor for a practical atmospheric pressure

    Tsuyoshi Hyakutake, Ichiro Okura, Keisuke Asai, Hiroyuki Nishide

    JOURNAL OF MATERIALS CHEMISTRY   18 ( 8 ) 917 - 922  2008  [Refereed]

     View Summary

    A dual-mode and a non-Stern - Volmer type oxygen pressure-sensitive coating was prepared by combining the cobaltporphyrin (CoP) ligated with a polymer and 1-pyrenebutyric acid (Py): the combination of the rapid and reversible oxygen (O-2)-adduct formation of the CoP was accompanied by a visible absorption spectral change and luminescence quenching of Py with oxygen. The oxygen sensor composed of CoP/Py was successfully characterized by a significantly high oxygen sensitivity under the practical atmospheric oxygen pressure of 10 - 21 kPa. Py was adsorbed on an anodized aluminium substrate. Its luminescence decreased by quenching with oxygen which obeyed the conventional Stern Volmer equation. Copolymers of vinylidenechloride with 1-vinylimidazole, 1-vinyl-2-methylimidazole, and 4-vinylpyridine (1, 2 and 3, respectively) were prepared to provide both an oxygen-barrier coating for the first luminescent Py layer and CoP ligation for tuning the oxygen-adduct formation equilibrium. The luminescent Py layer was further coated with a second polymer layer: The oxygen-barrier polymer coating enhanced the Stern - Volmer type luminescence intensity from the Py layer. Visible absorption of the CoP-containing polymer second layer increased in response to the oxygen-adduct formation or oxygen partial pressure, which overlapped and reduced the luminescence from the Py layer. The sum of the luminescence decreased along with an increase in the oxygen partial pressure, yielding a non-Stern - Volmer type response or high sensitivity to the oxygen partial pressure.

    DOI

  • Direct visualization of oxygen distribution in operating fuel cells

    Junji Inukai, Kenji Miyatake, Kenji Takada, Masahiro Watanabe, Tsuyoshi Hyakutake, Hiroyuki Nishide, Yuzo Nagumo, Masayuki Watanabe, Makoto Aoki, Hiroshi Takano

    ANGEWANDTE CHEMIE-INTERNATIONAL EDITION   47 ( 15 ) 2792 - 2795  2008  [Refereed]

    DOI

  • Optical oxygen-sensing polymers for a practical atmospheric pressure

    Nishide, H, Hyakutake, T

    American Chemical Society, Polymer Preprints, Division of Polymer Chemistry   49 ( 1 ) 545  2008  [Refereed]

  • Block copolymers containing stable free radicals: Synthesis and magnetic force microscopic morphological investigations

    Suga, T, Mather, B.D, Nishide, H, Long, T.E

    American Chemical Society, Polymer Preprints, Division of Polymer Chemistry   49 ( 1 ) 304 - 305  2008  [Refereed]

  • Very high-spin organic polymers based on hyperbranched マ�-conjugations

    Nishide, H, Lbe, T, Fukuzaki, E

    American Chemical Society, Polymer Preprints, Division of Polymer Chemistry   49 ( 1 ) 133 - 134  2008  [Refereed]

  • Conductive characteristics of radical-bearing polythiophenes using a microcomb-shaped electrode

    Manabu Tanaka, Kaoru Hatta, Tomohiko Edura, Ken Tsutsui, Yasuo Wada, Hiroyuki Nishide

    POLYMERS FOR ADVANCED TECHNOLOGIES   18 ( 11 ) 925 - 931  2007.11  [Refereed]

     View Summary

    The electric conductivity of x-conjugated and radical-bearing polymers, i.e., polythiophenes bearing pendant galvinoxyl and phenoxyl radical groups, was measured using a microcomb-shaped electrode. The electric conductivity was found to be enhanced by the radical content in the polymer. The infrared (IR) and Raman spectroscopies suggested a structural change from an aromatic form to a quinoid one in the polythiophene backbone by the phenoxyl radical generation. The effect of the pendant galvinoxyl radical's unpaired electron on the electric conductivity of the polythiophene was discussed by comparing the conductivity of a radical-bearing polystyrene and a polythiophene mixed with low-molecular radical molecules. Copyright (C) 2007 John Wiley & Sons, Ltd.

    DOI

  • Alternate network film of thiol group-terminated polythiophene and gold nanoparticle

    Manabu Tanaka, Remi Fujita, Hiroyuki Nishide

    POLYMER   48 ( 20 ) 5884 - 5888  2007.09  [Refereed]

     View Summary

    The thiol group-terminated polythiophenes were prepared via the Pd-catalyzed coupling reaction of the bromo group-terminated polythiophene derivatives and methylthiophenylboronic acid, and were mixed with the nanometer-sized gold particle to form a self-assembled network film of the alternate conjugation of the polythiophene with the gold nanoparticle. The electron microscopy and X-ray photoelectron spectroscopy of the films supported the formation of a polythiophene/gold nanoparticle alternate network structure through the S-Au linkages. The high electric conductivity and its low activation energy on the network film suggested that the conductive characteristic of the film originated from that of the pi-conjugated polythiophene backbone connected with the gold nanoparticle. (c) 2007 Elsevier Ltd. All rights reserved.

    DOI

  • Structural implication of oxoammonium cations for reversible organic one-electron redox reaction to nitroxide radicals

    Yasunori Yonekuta, Kenichi Oyaizu, Hiroyuki Nishide

    CHEMISTRY LETTERS   36 ( 7 ) 866 - 867  2007.07  [Refereed]

     View Summary

    Structures and electrochemical behaviors of nitroxide radicals reveal that their rapid and reversible redox reactions are based not only on their chemical stability but also on the increased sp(2) character of nitrogens which is intermediate between the purely sp(2) and sp(3) nitrogens in oxoammonium cations and amines, respectively.

  • Preparation of acid-functionalized poly(phenylene oxide)s and poly(phenylene sulfone) and their proton conductivity

    Takahiro Tago, Norikazu Kuwashiro, Hiroyuki Nishide

    BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN   80 ( 7 ) 1429 - 1434  2007.07  [Refereed]

     View Summary

    A series of highly acid-functionalized poly(phenylene oxide)s and poly(phenylene sulfone) were prepared and proton conductivity in their membranes is discussed. Phosphorylated poly(phenylene oxide)s were prepared via the oxidative polymerization of phosphonoxyphenols in alkaline water, along with a facile monomer preparation. A poly(phenylene oxide) bearing a sulfamide acid group was prepared by reacting amidosulfate with the corresponding carboxylated poly(phenylene oxide). A sulfonated poly(phenylene sulfone) was prepared by hydrogen peroxide oxidation of the sulfonated poly(phenylene sulfide). All these acid-functionalized polymers showed appropriate thermal stability based on the aromatic backbone. The polymers had a high ion-exchange capacity, were water-soiuble, but gave transparent and flexible membranes after compositing with the poly(ethylene oxide). Some of the membranes displayed a high proton conductivity of 10(-4) S cm(-1) at 120 degrees C under dry conditions.

  • Synthesis of porphyrins bearing uracyl groups and their assembly induced by melamine derivatives

    Satoshi Arai, Hiroki Ohshiro, Hiroyuki Nishide, Shinji Takeoka

    POLYMERS FOR ADVANCED TECHNOLOGIES   18 ( 6 ) 497 - 501  2007.06  [Refereed]

     View Summary

    Self-assembled porphyrins via noncovalent bonding have attracted wide-ranging researchers in material science. We reported herein the synthesis of the tetraphenyl porphyrin derivatives bearing uracyl groups as acceptor-donor-acceptor (ADA) type hydrogen bonding units, through the condensation of 5,10- or 5,15-bis (3-amino-4-ethylhexylphenyl) porphyrin derivatives with 6-carboxyuracyl derivatives. When two porphyrins having uracyl groups at the different substituted positions were respectively mixed with a melamine derivative in benzene, H-1 NMR spectra showed that the 5,15 substituted uracyl porphyrin formed a hydrogen-bonded suprastructure with the melamine derivative as a complementary molecule to the uracyl moiety, although the other 5,10-substituted uracylporphyrin could not form such a structure. The SEM observation indicated that the mixture with the 5,15-substituted uracyl porphyrin and the melamine with long alkyl chains formed a sheet-like structure. Copyright (C) 2007 John Wiley & Sons, Ltd.

    DOI

  • Triarylamine-combined nitronyl nitroxide and its hole-transporting property

    Takashi Kurata, Kenichiroh Koshika, Fumiaki Kato, Junji Kido, Hiroyuki Nishide

    POLYHEDRON   26 ( 9-11 ) 1776 - 1780  2007.06  [Refereed]

     View Summary

    N,N-Bis(4-methoxyphenyl)-4-(1-oxyl-3-oxide-4,4,5,5-tetramethylimidazolin-2-yl)phenylamine (1) was synthesized as a durable nitronyl nitroxide radical combined with a triarylamine moiety. Cyclic voltammetry and UV-Vis absorption spectra during the electrochemical oxidation of 1 revealed that the first redox was derived from the triarylamine moiety. The ionization potential of I was measured by photoelectron spectroscopy to be -5.4 eV, which was appropriate as a hole-transporting material. A single-layer hole-only device was fabricated with the radical molecule 1 dispersed in polycarbonate (ITO/1:polycarbonate/Al): The radical-layer exhibited a maximum current density of 0.2 mA/cm(2) which was applicable for organic electronic devices. (c) 2006 Elsevier Ltd. All rights reserved.

    DOI

  • Aromatic-aromatic interaction between 2,3,5-triphenyl-2H-tetrazolium chloride and poly(sodium 4-styrenesulfonate)

    Ignacio Moreno-Villoslada, Felipe Gonzalez, Luciano Rivera, Susan Hess, Bernabe L. Rivas, Toshimichi Shibue, Hiroyuki Nishide

    JOURNAL OF PHYSICAL CHEMISTRY B   111 ( 22 ) 6146 - 6150  2007.06  [Refereed]

     View Summary

    Aromatic-aromatic interactions are found between the cationic molecule 2,3,5-triphenyl-2H-tetrazolium chloride (TTC) and the molecule poly(sodium 4-styrenesulfonate) (PSS) which makes the overall interaction of TTC with PSS more intense than the interaction with other polyanions containing sulfonate groups and produces a decrease on the redox ability of TTC. Diafiltration was used to compare the binding of TTC to PSS, poly(sodium vinylsulfonate) (PVS), and the more hydrophobic poly(sodium 2-(N-acrylamido)-2-methyl-propanesulfonate) (PAMPS). The UV-vis spectrum of TTC is changed in the presence of the aromatic polyanion. The H-1 NMR signals of TTC are broadened and shifted in the presence of PSS, suggesting the occurrence of pi-pi interactions. Moreover, nuclear Overhauser effects (NOE) between the TTC and PSS protons are found. Possible structures for the complex are proposed.

    DOI

  • Cathode- and anode-active poly(nitroxylstyrene)s for rechargeable batteries: p- and n-type redox switching via substituent effects

    Takeo Suga, Yong-Jin Pu, Shinji Kasatori, Hiroyuki Nishide

    MACROMOLECULES   40 ( 9 ) 3167 - 3173  2007.05  [Refereed]

     View Summary

    Three polystyrenes bearing redox-active nitroxide radical(s) in each repeating unit, poly[4-(N-tert-butyl-N-oxylamino)styrene] (1), poly[3,5-di(N-tert-butyl-N-oxylamino)styrene] (2), and poly[4-(N-tert-butyl-N-oxylamino)-3-trifluoromethylstyrene] (3), were synthesized via free radical polymerization of protected precursor styrenic derivatives and subsequent chemical oxidation. The radicals in these polymers were robust at ambient conditions, and the polymers possessed radical densities of 2.97 x 10(21), 4.27 x 10(21), and 1.82 x 10(21) unpaired electrons/g for 1-3, respectively, resulting in an electrode-active material with a high charge/discharge capacity. Particularly, the dinitroxide functional polymer 2 possessed the highest radical density. Cyclic voltammetry of the poly(nitroxylstyrene) 1 revealed a reversible redox at 0.74 V vs Ag/AgCl, which was assigned to the oxidation of the nitroxide radical to form the oxoammonium cation (p-type doped state). On the other hand, the poly(nitroxylstyrene) ortho-substituted with the electron-withdrawing trifluoromethyl group 3 showed a reversible redox at -0.76 V, ascribed to the n-type redox pair between the nitroxide radical and the aminoxy anion. Thus, the nitroxide radical polymer could be switched from p-type material suitable for a cathode to n-type material (anode-active) via altering the electron-withdrawing character of the substituents on the poly(nitroxylstyrene). This is the first report of an n-type radical polymer and the first report of using substituent effects to switch the redox behavior of the polymer. This versatile switching ability enables these polymers to function as components of metal-free electrodes in rechargeable batteries.

    DOI

  • Nanometer-sized polyradical particles: Organic magnetic dot array formed on a silicon microfabricated substrate

    Manabu Tanaka, Shingo Imai, Takashi Tanii, Yoshiteru Numao, Naonobu Shimamoto, Iwao Ohdomari, Hiroyuki Nishide

    JOURNAL OF POLYMER SCIENCE PART A-POLYMER CHEMISTRY   45 ( 3 ) 521 - 530  2007.02  [Refereed]

     View Summary

    A magnetically active, purely organic dot array was formed by the selective deposition of polyradical nanoparticles on array-like-formed pits on a silicon substrate. The nanometer-sized polyradical particles, poly(4-methacryoyloxy-2,2,6,6-tetramethylpiperidine-1-oxyl), were prepared by the emulsion polymerization of 4-methacryloy-loxy-2,2,6,6-tetramethylpiperidine-1-acetoxyl followed by a deprotection reaction and oxidation in air. The size (diameter) and radical spin concentration of the polyradical nanoparticles were tunable between the polymerization and oxidation conditions. Electrochemical studies revealed the redox property of the polyradical nanoparticles. The magnetic response image of the polyradical nanoparticles was obtained by magnetic force microscopy, reflecting their radical spin concentrations. These results suggested a possible approach for the use of organic polyradical nanoparticles as organic magnetic dot arrays. (c) 2006 Wiley Periodicals, Inc.

    DOI

  • Triarylamine-bearing poly(1,4-phenylenevinylene): Facile preparation and its durable aminium polyradical

    Takashi Kurata, Yong-Jin Pu, Hiroyuki Nishide

    POLYMER JOURNAL   39 ( 7 ) 675 - 683  2007  [Refereed]

     View Summary

    Poly [2-{bis(4-methoxyphenyl)amino}phenyl-5-(2-ethylhexyloxy)-1,4-phenylenevinylene] 1 was prepared via the Gilch reaction of the p-bis(chloromethyl)benzene monomer, 2-{bis(4-methoxyphenyl)aminophenyl)-alpha,alpha'-dichloro-p-xylene. The Gilch reaction facilitated the preparation of the polyphenylenevinylene with a triarylamine pendant group when compared to that via the Heck polycondensation. The molecular weight of the polymer was approximately 4.0 x 10(5), and it was soluble in common solvents and was reversibly redoxed due to the pendant arylamine moiety. Chemical oxidation of I afforded the corresponding aminium polyradical 1(+) with the half life-time of ca. 2 weeks under ambient conditions. ESR and magnetization measurements of 1(+) revealed a forbidden multiplet signal and an average spin quantum number (S) of 3/2 at low temperature, respectively. The polyradical 1(+) was the first example of a high molecular weight, high-spin organic polymer with solvent-solubility and film formability. 2,3-Bis[N,N-bis(4-methoxyphenyl)aminophenyl]stilbene 2 and its aminium diradical 2(+) were also prepared as the model dimer compounds; 2(+) was a triplet molecule at low temperature. The effect of the pi-conjugated poly(1,4-phenylenevinylene) backbone on the high-spin alignment was also discussed.

    DOI

  • Tuning the pK(a) of the antihistaminic drug chlorpheniramine maleate by supramolecular interactions with water-soluble polymers

    Ignacio Moreno-Villoslada, Felipe Gonzalez, Bernabe L. Rivas, Toshimichi Shibue, Hiroyuki Nishide

    POLYMER   48 ( 3 ) 799 - 804  2007.01  [Refereed]

     View Summary

    The interaction of the pharmacologically important chlorpheniramine maleate (CPM) with polyanions containing sulfonate groups such as poly(sodium 4-styrenesulfonate) (PSS), poly(sodium vinylsulfonate) (PVS), and the more hydrophobic poly(sodium 2-(N-acrylamido)-2-methyl-propanesulfonate) (PAMPS) has been studied by H-1 NMR. It was found that the pK(a) of the low-molecular weight molecule (LMWM) may be modified by its interaction with the polyanions, changing from 3 to 5, due to electric charge compensation. Interestingly, the interaction of CPM with PSS produces changes in CPM resonances, such as a general broadening and upfield shifts of the signals, and NOE effects between the LMWM and the water-soluble polymer (WSP) that indicate the presence of pi-pi interactions. (c) 2006 Elsevier Ltd. All rights reserved.

    DOI

  • Atropisomers of meso-conjugated uracyl porphyrin derivatives and their assembling structures

    Satoshi Arai, Daisuke Niwa, Hiroyuki Nishide, Shinji Takeoka

    ORGANIC LETTERS   9 ( 1 ) 17 - 20  2007.01  [Refereed]

     View Summary

    We have synthesized a 5,15 meso-substituted methyluracyl porphyrin derivative bearing 6-methyluracyl units directly at the meso positions. The atropisomerization was regulated by steric replusion between the methyl substituents. When the atropisomers were mixed with alkylated melamine as a complementary hydrogen-bonding unit, the hydrogen-bonded assemblies were analyzed by diffusion-ordered spectroscopy (DOSY) in solution, which clarified that the alpha alpha isomer formed a face-to-face dimer, whereas the alpha beta isomer took a zigzag structure.

    DOI

  • Battery-inspired, nonvolatile, and rewritable memory architecture: A radical polymer-based organic device

    Yonekuta, Y, Susuki, K, Oyaizu, K, Honda, K, Nishide, H

    Journal of the American Chemical Society   129 ( 46 ) 14128 - 14129  2007  [Refereed]

  • Low-energy driven electrochromic devices using radical polymer as transparent counter electroactive material

    Yusuke Takahashi, Kenichi Oyaizu, Kenji Honda, Hiroyuki Nishide

    JOURNAL OF PHOTOPOLYMER SCIENCE AND TECHNOLOGY   20 ( 1 ) 29 - 34  2007  [Refereed]

     View Summary

    Electroactive and transparent organic radical polymers offered a novel design of materials for electrochromic (EC) devices. A radical polymer containing 2,2,6,6-tetramethylpiperidinoxyl (TEMPO) groups as redox active sites per repeating unit was spin-coated on a counter ITO/glass electrode of the EC device which was also comprised of Prussian blue (PB) as an electrochromic material on ITO and ion-conducting polymer gel between the two electrodes. Electrochemical switching of the cell was monitored using the visible absorption of PB (lambda(max) = 700 nm) that appeared in the oxidized (mixed-valence) state, while the radical polymer was transparent in the visible region in both redox states. PB and the radical polymer were concurrently reduced and oxidized, respectively, on each electrode during the charging process, which corresponded to the decoloration of the cell. The coloration was effected by a discharging process. The electrochromic switching and stability of the cell was characterized by a low driving voltage AV and, consequently, a small driving energy integral Delta Vi(t)dt, as a result of a small potential gap between PB and the radical polymer. The optical switch was fast and fully reversible by virtue of the large heterogeneous electron transfer rate constant of the TEMPO center (k(0) approximate to 10(-1) cm/s). The polymeric counter electrode material, without dissolution into the electrolyte layer, led to a good open circuit memory that did not require refreshing charges to maintain the redox states of PB.

  • Photocrosslinked nitroxide polymer cathode-active materials for application in an organic-based paper battery

    Takeo Suga, Hiroaki Konishi, Hiroyuki Nishide

    CHEMICAL COMMUNICATIONS   ( 17 ) 1730 - 1732  2007  [Refereed]

     View Summary

    A nitroxide radical functional polymer was photocrosslinked for the first time without significant side reactions, producing a cathode-active thin film, leading to an organic-based paper battery.

    DOI

  • An unpaired electron-based hole-transporting molecule: Triarylamine-combined nitroxide radicals

    Takashi Kurata, Kenichiroh Koshika, Fumiaki Kato, Junji Kido, Hiroyuki Nishide

    CHEMICAL COMMUNICATIONS   ( 28 ) 2986 - 2988  2007  [Refereed]

     View Summary

    A durable nitroxide radical combined with a triarylamine moiety exhibited a hole-drift mobility of 6 x 10(-3) cm(2) V-1 s(-1), to which the aminophenyl nitroxide structure contributed.

    DOI

  • Proton conductivity in the dry membrane of poly(sulfonic acid) and polyamine layer-by-layer complex

    Takahiro Tago, Hirokazu Shibata, Hiroyuki Nishide

    CHEMICAL COMMUNICATIONS   ( 28 ) 2989 - 2991  2007  [Refereed]

     View Summary

    A layer-by-layer assembled and molecular-complexed polymer membrane was prepared by the simple combination of poly(4-styrenesulfonic acid) and poly(allylamine) on a comb-shaped gold electrode: it displayed a very high proton conductivity of 10(-3) S cm(-1) under a dry condition at 120 degrees C.

    DOI

  • Regioselective and enzymatic production of ホウ-resorcylic acid from resorcinol using recombinant Escherichia coli cells expressing a novel decarboxylase gene

    Iwasaki, Y, Kino, K, Nishide, H, Kirimura, K

    Biotechnology Letters   29 ( 5 ) 819 - 822  2007  [Refereed]

  • Magnetic force microscopy as a new tool to evaluate local magnetization of organic radical polymers

    Manabu Tanaka, Yusuke Saito, Hiroyuki Nishide

    CHEMISTRY LETTERS   35 ( 12 ) 1414 - 1415  2006.12  [Refereed]

     View Summary

    Magnetic force microscopy (MFM) was used to study the single-molecular magnetic response of the proxyl radical-terminated poly (amidoamine) dendrimer. Local magnetization of the organic radical molecules was evaluated by the MFM intensity, which correlated to the number of unpaired electrons per molecule.

  • Complex formation between rhodamine B and poly(sodium 4-styrenesulfonate) studied by H-1-NMR

    Ignacio Moreno-Villoslada, Rodrigo Gonzalez, Susan Hess, Bernabe L. Rivas, Toshimichi Shibue, Hiroyuki Nishide

    JOURNAL OF PHYSICAL CHEMISTRY B   110 ( 43 ) 21576 - 21581  2006.11  [Refereed]

     View Summary

    A H-1 NMR study is presented for the binding of rhodamine B (RB) to the polyanion containing aromatic groups poly( sodium 4-styrenesulfonate) (PSS), which is also evidenced by diafiltration. H-1 NMR spectra showed an accentuated upfield shift of proton H6 ' of the benzoic ring of RB at pH 7, indicating the stacking of RB onto PSS. The corresponding structure is proposed which is in accordance to Hunter and Sanders rules. At pH 2, an upfield shift of the xanthene protons of RB would indicate a highly condensed state for this molecule.

    DOI

  • Catalyzed oxidative polymerization to form poly (2,6-dimethyl-1,4-phenylene oxide) in water using water-soluble copper complex

    Kei Saito, Norikazu Kuwashiro, Hiroyuki Nishide

    POLYMER   47 ( 19 ) 6581 - 6584  2006.09  [Refereed]

     View Summary

    Simply stirring 2,6-dimethylphenol with a small amount of copper complex catalyst in alkaline water provided a green way to prepare poly(2 6-dimethyl-1.4-phenylene oxide) in water. We have searched for the optimum alkaline-resistant metal catalyst from a series of watersoluble copper complexes. The formed polymer was easily separated as an off-white powder by filtration after salting out. (c) 2006 Elsevier Ltd. All rights reserved.

    DOI

  • A high-spin and helical organic polymer: Poly {[4-(dianisylaminium)phenyl]acetylene}

    Hidenori Murata, Daisuke Miyajima, Hiroyuki Nishide

    MACROMOLECULES   39 ( 19 ) 6331 - 6335  2006.09  [Refereed]

     View Summary

    A high-spin polyradical, poly {[4-(dianisylaminium)phenyl]acetylene} 1(+), was synthesized as a pi-conjugated polymer with an excess of the one-handed helical structure bearing stable aminium cation radicals. [4-(Dianisylamino)phenyl]acetylene (3) was synthesized and polymerized using [Rh(norbornadiene)Cl](2) in (R)-1-phenylethylamine, (S)-1-phenylethylamine, or triethylamine to produce the corresponding poly {[4-(dianisylamino) phenyl]acetylene} 1 (1((R)-PEA), 1((S)-PEA), and 1(TEA)). The positive and negative Cotton effects were observed at 270-450 nm for the polymers 1((R)-PEA) and 1((S)-PEA), indicating that an excess of the one-handed helical polyacetylene backbone was induced by the polymerization using chiral solvents despite the achiral monomer. The oxidation of 1 with NOPF6 gave the corresponding aminium polyradicals 1(+), and the circular dichroism (CD) spectrum was observed even after the oxidation of the helical polyradical 1((R)-PEA)(+). The SQUID and NMR shift measurements indicated a high-spin state of the polyradical at room temperature and a contribution of the well-regulated helical structure to the through-space interaction between the aminium cation radicals.

    DOI

  • Covalent fixation of the cyclic tetramer of a metallo-porphyrin based on self-complementary quadruple hydrogen bonding

    Haruki Ohkawa, Akihiro Takayama, Satoshi Nakajima, Hiroyuki Nishide

    CHEMISTRY LETTERS   35 ( 9 ) 1076 - 1077  2006.09  [Refereed]

     View Summary

    The stability of quadruple hydrogen bonding in the cyclic tetramer of a metallo-porphyrin before and after a covalent fixation was investigated. According to competition and energy-transfer experiments, the exchange reaction between the cyclic tetramers of the metallo-porphyrin was fully suppressed by the covalent fixation. This spontaneous cyclization-covalent fixation strategy based on olefin metathesis can open the way to the use of cyclic assemblies in a solid phase.

    DOI

  • Reversible oxygen-binding and facilitated oxygen trans-port in membranes of polyvinylimidazole complexed with cobalt-phthalocyanine

    Nalinakumari Preethi, Hiromi Shinohara, Hiroyuki Nishide

    REACTIVE & FUNCTIONAL POLYMERS   66 ( 8 ) 851 - 855  2006.08  [Refereed]

     View Summary

    A membrane with an oxygen-binding capability and nanometer thickness was prepared by complexing cobalt-phthalocyanine as an oxygen carrier with the copolymer of vinylimidazole and octyl methacrylate. The complex showed reversible oxygen-binding in the solution state at low temperature. The permeability coefficient of oxygen (P-O2) through this membrane was much higher than that of nitrogen (P-N2) (P-O2/P-N2 > 20) and increased at lower upstream oxygen pressure. The facilitation of oxygen transport was augmented by increasing the concentration of the oxygen carrier, cobalt-phthalocyanine fixed in the membrane. (C) 2005 Elsevier B.V. All rights reserved.

    DOI

  • Enhanced oxygen permeation through a porous glass membrane containing phthalocyanato- and porphyrinato-cobalt complexes as an oxygen carrier

    Nalinakumari Preethi, Hirorni Shinohara, Hiroyuki Nishide

    BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN   79 ( 8 ) 1308 - 1311  2006.08  [Refereed]

     View Summary

    The pore surface of a porous glass membrane was modified with phthalocyanato- and tetraphenylporphyrinato-1-(benzylimidazole)cobalt(II) complexes, which specifically and reversibly binds molecular oxygen from air. The lower oxygen-binding affinity enhanced surface oxygen diffusion which improved permeability (3.0 x 10(-11) kmol ms(-1) m(-2) kPa(-1)) and (oxygen/nitrogen) permselectivity (10).

    DOI

  • Synthesis of N-(4-vinyl)benzylimidazole copolymer and oxygen-binding properties of its complex with cobaltporphyrin

    Shentu Baoqing, Liu Qun, Weng Zhixue, Nishide Hiroyuki

    ACTA POLYMERICA SINICA   ( 5 ) 682 - 685  2006.08  [Refereed]

     View Summary

    N-(4-vinyl)benzylimidazole and its copolymer with octyl methacrylate (PBIOM) were synthesized and characterized, and oxygen-binding properties of cobaltporphyrin (CoP) complexes with imdazole ligands were studied. The weight-average molecular weight and imidazole content of PBIOM were determined to be 3.4 x 10(5) and 57 mol % by GPC and elemental analysis, respectively. PBIOM or benzylimidazole (BIm) and CoPn chloroform solution were mixed to complex the imidazolyl residue of the ligands with the fifth coordination site of CoP under nitrogen atmosphere to get Cop complexes. CoP complex displayed a reversible change in the UV-visible absorption spectrum from the deoxy form to the oxygen-binding one with an isosbestic point, in response to the partial oxygen pressure of the atmosphere. The oxygen-binding equilibrium curves of CoP complexes obeyed a Langmuir isotherm, to give the oxygen-binding affinity p(50) (oxygen partial pressure at which half of the CoP binds with oxygen). At the same partial oxygen pressure, the oxygen-binding ratio of CoP-BIm complex was a little larger than that of CoP-PBIOM complex. The oxygen-binding affinity of CoP-PBIOM complex in the solid membrane state was larger than that in chloroform solution. The half lifetime of CoP-PBIOM membrane at 60 degrees C was 40.7 h,while that of CoP-Blm membrane (poly(octyl methacrylate) as matrix) was 8.8 h, indicating that polymer ligand significantly prolonged the lifetime of CoP complex.

  • Poly(2-diphenylamino-1,4-phenylenevinylene): Its preparation via chemical vapor deposition polymerization

    Yusuke Takahashi, Takashi Kurata, Hiroyuki Nishide, Chun-Young Lee, Eui-o Do Do, Jung-Il Jin

    SCIENCE AND TECHNOLOGY OF ADVANCED MATERIALS   7 ( 5 ) 475 - 480  2006.07  [Refereed]

     View Summary

    2,5-Bis(chloromethyl)triphenylamine I was prepared and polymerized via the Gilch reaction to give poly(2-diphenylamino-1,4-phenylenevinylene) 2G as a solvent-soluble Phi-conjugated polymer. 1 was also polymerized via the chemical vapor deposition to yield the precursor polymer of 2C, which was heated under vacuum to yield a yellow or brown thin film of 2C on substrates such as glass and a silicon wafer. Spectroscopies of the film supported the formation of the poly (2-diphenylamino-1,4-phenylenevinylene) 2C. The arylamine moiety of the 2C film worked as a functional group like a redox site. (c) 2006 NIMS and Elsevier Ltd. All rights reserved.

    DOI

  • Practical nano-chemistry

    Hiroyuki Nishide, Kuniaki Tatsuta, Toshiyuki Momma

    SCIENCE AND TECHNOLOGY OF ADVANCED MATERIALS   7 ( 5 ) 395 - 396  2006.07  [Refereed]

    DOI

  • Packing of submicrometer-sized polystyrene particles within the micrometer-sized recessed patterns on silicon substrate

    Manabu Tanaka, Naonobu Shimamoto, Takashi Tanii, Iwao Ohdomari, Hiroyuki Nishide

    SCIENCE AND TECHNOLOGY OF ADVANCED MATERIALS   7 ( 5 ) 451 - 455  2006.07  [Refereed]

     View Summary

    The packing of submicrometer-sized polystyrene particles within the micrometer-sized recessed patterns were achieved using silicon-microfabricated substrates and a simple dipping and pulling-up process. The polystyrene particles were selectively deposited within the micrometer-sized square, triangular, or circular recessed patterns by tuning the experimental conditions during the pulling-up process. The process produced a capillary force, i.e., a gas-liquid interfacial tension, to push the particles into the recessed patterns on the substrate. In most cases, the selectively depositing particles within the recessed patterns self-organically formed the closest packing structures. However, a special phenomenon, cubic packing structures of the particles, was observed when using square patterns with a few times larger side-length than the particle diameters. Several particle packing structures within different-sized square patterns were demonstrated, and the relationship between the particle packing structures and square pattern sizes were discussed. (c) 2006 NIMS and Elsevier Ltd. All rights reserved.

    DOI

  • N,N-bis(4-{5-[N,N-bis(4-methoxyphenyl)-N-yloammonio]-2-methylstyryl}phenyl)ammoniumyl triradical: A trimer model of high-spin poly[(4-methoxyphenyl-N-yloammonio)-1,2(or 4)-phenylenevinylene-1,2(or 4)-phenylene]

    Eiji Fukuzaki, Shigemoto Abe, Hiroyuki Nishide

    BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN   79 ( 6 ) 953 - 958  2006.06  [Refereed]

     View Summary

    Hyperbranched poly [(4-methoxyphenyl-N-yloammonio)-1,2(or 4)-phenylenevinylene-1,2(or 4)-phenylene], obtained by the polycondensation of N-(4-methoxyphenyl)-N-(4-vinylphenyl)-3-bromo-4-vinylaniline and the subsequent oxidation, three-directionally satisfied the non-Kekule-type pi-conjugation and ferromagnetic connectivity of the unpaired electrons of triarylammoniumyl cationic radicals, and behaved as a high-spin organic polymer even at room temperature. The trimer model compound, N- (4-{5- [N,N-bis(4-methoxyphenyl) amino] - 2-methylstyryl}-3-methylphenyl) -N(4-15-[N,N-bis(4-methoxyphenyl)amino]-2-methylstyryl)phenyl)-4-methoxyaniline, was synthesized from N-(4-methoxyphenyl)-N-(4-vinylphenyl)-3-methyl-4-vinylaniline. The corresponding ammoniumyl triradical displayed an average S (spin quantum number) value of 3/2, which supported the strong spin-coupling between the unpaired electrons of the ammoniumyl radicals through the pi-conjugated and branched phenylenevinylene structure. Head-to-tail linkage and the branched structure of the polymer were also studied by a model reaction of N-(4-methoxyphenyl)-N-(4-vinylphenyl)3 - methyl-4-vinylaniline and bromobenzene.

  • Cyclic tetramer of a metalloporphyrin based on a quadruple hydrogen bond

    Haruki Ohkawa, Akihiro Takayama, Satoshi Nakajima, Hiroyuki Nishide

    ORGANIC LETTERS   8 ( 11 ) 2225 - 2228  2006.05  [Refereed]

     View Summary

    This paper describes the selective formation of a cyclic tetramer from a readily synthesized metalloporphyrin with two self-complementary quadruple hydrogen-bonding units. The extremely strong quadruple hydrogen-bonding unit, 2-ureido-4[1H]-pyrimidinone, enabled the formation of a stable cyclic tetramer based on a tetraphenylporphyrin derivative over a wide concentration range. This hydrogen-bonded tetramer is a new functional unit for use in a higher-ordered architecture of a supramolecular porphyrin assembly.

    DOI

  • 2,6,10-tris(dianisylaminium)-3,7,11-tris(hexyloxy)triphenylene: A robust quartet molecule at room temperature

    E Fukuzaki, H Nishide

    ORGANIC LETTERS   8 ( 9 ) 1835 - 1838  2006.04  [Refereed]

     View Summary

    A new triradical molecule, 2,6,10-tris(dianisylaminium)-3,7,11-tris(hexyloxy)triphenyiene 1(3+), was synthesized by oxidative trimerization, palladium-catalyzed amination, and subsequent oxidation. It was chemically stable with a half-life > 1 month and displayed the magnetic parameter of S = 3/2 even at room temperature.

    DOI

  • DFT oligomer approach to vibrational spectra of poly (p-phenylenevinylene)

    K Honda, Y Furukawa, H Nishide

    VIBRATIONAL SPECTROSCOPY   40 ( 2 ) 149 - 154  2006.03  [Refereed]

     View Summary

    Experimental Raman and infrared spectra of poly(p-phenylenevinylene) have been analyzed on the basis of the normal coordinate calculations based on the density functional theory method at the B3LYP/cc-pVDZ level for a model oligomer. Vibrational modes corresponding to optically active modes of an infinite polymer chain have been selected from the calculated results. On the basis of these normal vibrations, the observed vibrational spectra of poly( p-phenylenevinylene) have been explained successfully. The angles between the calculated transition dipole moment vectors and the polymer axis for some infrared bands agree with those derived from observed infrared dichroic spectrum. (c) 2005 Elsevier B.V. All rights reserved.

    DOI

  • マ�-Stacking of rhodamine B onto water-soluble polymers containing aromatic groups

    Moreno-Villoslada, I, Jofrテゥ, M, Miranda, V, Chandテュa, P, Gonzテ。lez, R, Hess, S, Rivas, B.L, Elvira, C, San Romテ。n, J, Shibue, T, Nishide, H

    Polymer   47 ( 19 ) 6496 - 6500  2006  [Refereed]

  • Magnetic properties of natural and modified DNAs

    Lee, C.H, Do, E.-D., Kwon, Y.-W., Choi, D.-H., Jin, J.-I., Oh, D.-K, Nishide, H, Kurata, T

    Nonlinear Optics Quantum Optics   35 ( 39449 ) 165 - 174  2006  [Refereed]

  • Membrane preparation of polysulfonic acid complexes by layer-by-layer adsorption

    T Tago, H Shibata, H Nishide

    MACROMOLECULAR SYMPOSIA   235   19 - 24  2006  [Refereed]

     View Summary

    The water-insoluble, thermostable and homogeneous polymer complex membrane formation of polysulfonic acids was examined by modifying the preparation conditions of the layer-by-layer adsorption method of the acid and base polymers. The complexation Of poly(4-styrenesulfonic acid) in the 0.15 unit mM solution with poly(allylamine) gave a polymer complex membrane on a gold substrate in which one polymer layer was formed with a thickness of 1 nm. Properties including the proton conductivity of the membrane suggested possible applications of the polymer complex membrane.

    DOI

  • Nitroxide-substituted polyether as a new material for batteries

    Takeo Saga, Kentaro Yoshimura, Hiroyuki Nishide

    MACROMOLECULAR SYMPOSIA   245   416 - 422  2006  [Refereed]

     View Summary

    Nitroxide-substituted polyether was synthesized as a cathode-active material for a secondary battery. Anionic ring-opening polymerization of a TEMPO-bearing glycidyl ether was carried out under bulk conditions to yield the corresponding polymer with the molecular weight of > 10(4). The obtained polymer was insoluble, but slightly swollen in the electrolyte solution (ethylene carbonate/propylene carbonate). The test cell fabricated with a carbon composite cathode of this radical polymer displayed a plateau voltage at 3.5 V vs. Li/Li+. The cell performance was maintained even with a higher amount of the radical polymer loaded in the composite electrode, which could be ascribed to the flexible and rubbery polyether backbone and its higher compatibility with the electrolyte solution.

    DOI

  • Room-temperature high-spin organic single molecule: Nanometer-sized and hyperbranched poly[1,2,(4)-phenylenevinyleneanisylaminium]

    E Fukuzaki, H Nishide

    JOURNAL OF THE AMERICAN CHEMICAL SOCIETY   128 ( 3 ) 996 - 1001  2006.01  [Refereed]

     View Summary

    Poly[1,2,(4)-phenylenevinyleneanisylaminium] 1 was synthesized by one-pot palladium-catalyzed polycondensation of N-(3-bromo-4-vinylphenyl)-N-(4-methoxyphenyl)-N-(4-vinylphenyl)amine 3 and subsequent oxidation with the thianthrene cation radical tetrafluoroborate: compound 1 three-directionally satisfies a non-Kekule-type pi-conjugation and the ferromagnetic connectivity of the unpaired electrons of the triarylaminium cationic radical. The average molecular weight of the polymer was 4700-5900 (degree of polymerization = 11-14), which gave a single molecular-based and globular-shaped image of ca. 15 nm diameter by atomic and magnetic force microscopies under ambient conditions. The aminium polyradical 1 with a spin concentration (determined by iodometry) of 0.65 spin/unit displayed an average S (spin quantum number) value of (7)/(2) even at 70 degrees C according to NMR and magnetization measurements.

    DOI

  • Hole-transporting property of star-shaped nitroxide radical molecule

    Fumiaki Kato, Yoshihiko Kinugasa, Takashi Kurata, Junji Kido, Hiroyuki Nishide

    JOURNAL OF PHOTOPOLYMER SCIENCE AND TECHNOLOGY   19 ( 2 ) 143 - 144  2006  [Refereed]

  • Synthesis and electrochemical and electroluminescent properties of N-phenylcarbazole-substituted poly(p-phenylenevinylene)

    F Liang, T Kurata, H Nishide, J Kido

    JOURNAL OF POLYMER SCIENCE PART A-POLYMER CHEMISTRY   43 ( 23 ) 5765 - 5773  2005.12  [Refereed]

     View Summary

    An N-phenylcarbazole-containing poly(p-phenylenevinylene) (PPV), poly [(2-(4'-carbazol-9-yl-phenyl)-5-octyloxy-1,4-phenylenevinylene)-alt-(2-(2'-ethylhexyloxy)-5-methoxy-1,4-phenylenevinylene)] (Cz-PPV), was synthesized, and its optical, electrochemical, and electroluminescent properties were studied. The molecular structures of the key intermediates, the carbazole-containing boronic ester and the dialdehyde monomer, were crystallographically characterized. The polymer was soluble in common organic solvents and exhibited good thermal stability with a 5% weight loss at temperatures above 420 degrees C in nitrogen. A cyclic voltammogram showed the oxidation peak potentials of both the pendant carbazole group and the PPV main chain, indicating that the hole-injection ability of the polymer would be improved by the introduction of the carbazole-functional group. A single-layer light-emitting diode (LED) with a simple configuration of indium tin oxide (ITO)/Cz-PPV (80 nm)/Ca/Al exhibited a bright yellow emission with a brightness of 1560 cd/m(2) at a bias of 11 V and a current density of 565 mA/cm(2). A double-layer LED device with the configuration of ITO/poly(3,4-ethylenedioxy-2,5-thiophene):poly (styrenesulfonic acid) (60 nm)/Cz-PPV (80 nm)/Ca/Al gave a low turn-on voltage at 3 V and a maximum brightness of 6600 cd/m(2) at a bias of 8 V The maximum electroluminescent efficiency corresponding to the double-layer device was 1.15 cd/A, 0.42 lm/w, and 0.5%. The desired electroluminescence results demonstrated that the incorporation of hole-transporting functional groups into the PPVs was effective for enhancing the electroluminescent performance. (c) 2005 Wiley Periodicals, Inc.

    DOI

  • Poly[4,6-bis(bis(4-methoxyphenyl)aminium)-1,2-phenylenevinylene]: A high-spin and durable polyradical

    H Murata, R Takada, H Nishide

    POLYHEDRON   24 ( 16-17 ) 2309 - 2314  2005.11  [Refereed]

     View Summary

    A purely organic and high-spin polyradical molecule was synthesized, along the non-Kekule and non-disjoint design of the pi-conjugated poly(1,2-phenylenevinylene) backbone pendantly 4,6-substituted with the robust arylamininium radicals. 4,6-Bis(bis(4-methoxyphenyl)amino)-2-bromostyrene was synthesized and polymerized with a Pd-phosphine catalyst to afford the head-to-tail linked polyradical precursor. Oxidation of the polymer with SbCl5 gave the aminium polyradical with a half-fire of >10 days at room temperature. A high-spin ground state with in average S = 5/2 for this polyradical was proved by magnetic susceptibility and ESR. (c) 2005 Elsevier Ltd. All rights reserved.

    DOI

  • Acid-functionalized poly(phenylene oxide)s: Their preparation and properties

    K Saito, T Tazaki, R Matsubara, H Nishide

    INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH   44 ( 23 ) 8626 - 8630  2005.11  [Refereed]

     View Summary

    Poly(phenylene oxide)s bearing carboxylic and sulfonic acids were prepared via oxidative polymerization of the corresponding phenol derivatives. Polymerization of 2-(ethoxycarbonyl)6-methylphenol yielded poly [2-(ethoxycarbonyl)-6-methyl- 1,4-phenylene oxide] with a high molecular weight, and its hydrolysis produced poly(2-carboxy-6-methyl-1,4-phenylene oxide) with a series of carboxylic acid contents. Polymerization of 4-bromo-2-(ethoxysulfonyl)-6-methylphenol produced poly(2-methyl-6-sulfo-1,4-phenylene oxide). The acid-functionalized poly(1,4-phenylene oxide)s showed a high thermal stability and proton conductivity.

    DOI

  • Electro- and magneto-responsible chiral polymers

    T Iwasaki, H Nishide

    CURRENT ORGANIC CHEMISTRY   9 ( 16 ) 1665 - 1684  2005.11  [Refereed]

     View Summary

    Helical polymers and macromolecules have precisely ordered stereostructures, and their potential applications include chiral separation and sensing based on molecular recognition and liquid crystalline formation by molecular ordering. Among them, pi-conjugated polymers with a helical structure have often exhibited unique electro- and magneto-responsibilies. In this review, we describe the helical pi-conjugated macromolecules as electro- and magneto-responsible materials including our recent studies. In Chapter 2, the recent studies of helical polymeric molecules with pi-conjugated structures are reviewed. We focus on "helicene" derivatives, which consist of fused-benzene and/or thiophene rings, in Chapter 3 and summarize their syntheses, characteristics, and optical properties based on the stiff structures and molecular ordering. Helical ladder polymers, "poly(thiaheterohelicene)s" comprised of fused-benzothiophene rings, are discussed in Chapter 4 among their stiff helical structure and pi-conjugation. The combined functions of electro- and magneto-properties of the chiral polymer are described using the example of poly(thiaheterohelicene)s, such as electron transmission along the helical main-chain and a molecule model of a molecular solenoid, in the final section.

  • Porphyrin capped with calix[4]arene derivative via hydrogen bonds

    S Arai, H Ohkawa, S Ishihara, T Shibue, S Takeoka, H Nishide

    BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN   78 ( 11 ) 2007 - 2013  2005.11  [Refereed]

     View Summary

    A calix[4]arene-porphyrin duplex was prepared by mixing equimolar amounts of hydroxy or carboxy calix[4]arene derivatives and pyridyl or o-aminophenylporphyrin derivatives. Electrospray ionization mass spectrometry (ESI-MS) was applied to screen a suitable pair of a calix[4]arene and a porphyrin. meso-Tetra(2-pyridyl)porphyrin formed a duplex with tetrahydroxy or tetrahydroxymethylcalix[4]arene via triple or quadruple hydrogen bonds. H-1 NMR spectra showed that the tetrahydroxycalix[4]arene was symmetrically located upon the porphyrin ring, whereas trihydroxycalix[4]arene was slanted on the porphyrin ring. The duplex of meso-tetra(2-pyridyl)porphyrinatocobalt(II) and tetrahydroxymethylcalix[4]arene formed a complex with benzylimidazole, which was capable of reversible dioxygen-binding. The capping structure upon porphyrin provided by calix[4]arene raised the life-time of dioxygen-adduct compared with the porphyrin without calix[4]arene.

    DOI

  • Oxidative polymerization in water to form sulfoalkoxy poly(phenylene oxide)s

    K Saito, T Masuyama, H Nishide

    BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN   78 ( 9 ) 1699 - 1701  2005.09  [Refereed]

     View Summary

    The oxidative polymerization of sulfonatopropoxyphenols in alkaline water, along with the easy monomer preparation, provided a simple and atom economical way to prepare sulfoalkoxy-pendant poly(phenylene oxide)s. The polymerization in alkaline water reduced the oxidation potential of the sulfonated phenols, and produced water-soluble polymers. The polymers produced a transparent, tough, and flexible membrane, which showed high thermal stability and proton conductivity.

    DOI

  • Synthesis of poly(3,4-azopyridylene) and oxygen-binding affinity of its complex with cobaltporphyrin

    BQ Shentu, ZX Weng, H Nishide

    CHINESE JOURNAL OF POLYMER SCIENCE   23 ( 4 ) 417 - 422  2005.07  [Refereed]

     View Summary

    Synthesis and characteristics of poly(3,4-azopyridylene) (PAP), conductivity and oxygen-binding affinity of its complex with meso-alpha,alpha,alpha,alpha-tetrakis(o-pivalamidophenyl) porphyrinatocobalt(II) (CoP) were studied. PAP was prepared by oxidative polymerization of 3,4-diaminopyridine (DAP) in DMF solution using CuCl/pyridine as the catalyst. IR and NMR results showed that the peak of amido group in DAP was converted to the azo group in PAP and a pi conjugated polymer was synthesized. The average molecular weight of PAP was determined to be 5.0 x 10(3). The PAP-CoP complex was prepared by complexing the pyridyl group of PAP with the fifth coordination site of CoP in DMF solution. In comparison with the CoP complex with a non-pi conjugated polymer, the PAP-CoP complex shows good electroconductivity of 5.8 x 10(-6) S cm(-1). The PAP-CoP complex displays a reversible change in the UV-Visible absorption spectrum from the deoxy form to the oxy or oxygen-binding one with an isosbestic point, in response to the partial oxygen pressure of the atmosphere. The oxygen-response behavior was monitored at the absorbance ascribed to the oxy form at 548 nm to give the oxygen-binding affinity. The oxygen-binding equilibrium curves of PAP-CoP complex obey a Langmuir isotherm. DMF has great effects on the oxygen-binding properties of the PAP-CoP complex. The oxygen-binding affinity of PAP-CoP complex in the solid state is higher than that in DMF solution. With decreasing temperature, the oxygen-binding affinity of the PAP-CoP complex increases.

  • Dissolution and diffusion of oxygen in and through poly(octyl methacrylate-co-vinylimidazole)/cobaltporphyrin complexed membranes

    BQ Shentu, ZX Weng, H Nishide

    ACTA POLYMERICA SINICA   ( 3 ) 345 - 349  2005.06  [Refereed]

     View Summary

    The dissolution and diffusion processes of oxygen in and through poly ( octyl methacrylate-co-vinylimidazole) (OIm)/cobaltporphyrin complexed membranes were discussed. Facilitated oxygen transport through a polymer membrane containing meso-alpha, alpha, alpha, alpha-tetrakis (o-pivalamidophenyl) porphyrinatocobalt ( Cop) as a fixed oxygen carrier was analyzed by a dual-mode transport model. It was found that CoP fixed in the solid membrane rapidly and reversibly bound with oxygen and the oxygen-binding equilibrium constants of CoP ( K) was 14 mol(-1)L. The oxygen absorption for the CoP-OIm membrane obeyed a Langmuir-type isotherm, while the nitrogen absorption showed a proportional increase with nitrogen pressure according to Henry's law. The physical solubility coefficient of oxygen (k(D)) in the polymer matrix was calculated to be 4.4 x 10(-5) cm(3) (STP) cm(-3) Pa-1 according to the adsorption results. Oxygen permeability coefficients (Po-2) of the OIm-CoP membranes steeply increased with a decrease in the pressure difference (Po-2) while Po-2 for the control membrane composed of inactive ( oxidized) Co(III) P was small and independent of po(2) indicating that the CoP carrier fixed in the membrane, interacts with oxygen and facilitates oxygen transport. The facilitation factor ( G) that indicates the degree of facilitated transport was 9. The ratio of the diffusion coefficient of oxygen for hopping between the fixed carriers (D-C) to the physical diffusion coefficient of oxygen through the matric polymer (D-D) was 0.08.

  • Synthesis and electrolumine scent property of poly (p-phenylenevinylene)s bearing triarylamine pendants

    F Liang, YJ Pu, T Kurata, J Kido, H Nishide

    POLYMER   46 ( 11 ) 3767 - 3775  2005.05  [Refereed]

     View Summary

    Two poly(p-phenylenevinylene) derivatives, TPA-PPV and TPA-CN-PPV, bearing a triarylamine pendant were synthesized by the Wittig-Horner and Knoevenagel reactions, respectively. The optical properties of the polymers were improved by energy transfer from the triarylamine pendant to the poly(p-phenylenevinylene) main chain. Cyclic voltammetry revealed that the HOMO energy level of the pendant TPA moiety is higher than that of the PPV main chain, suggesting that the hole injection from ITO into the TPA moiety, then from the TPA moiety into PPV is more favorable than directly from ITO into the PPV main chain. A single-layer light-emitting diode using TPA-PPV as the emitting layer exhibited a maximum brightness of 790 cd/m(2) at a bias of 8 V, while the control device employing commercially available MEH-PPV as the emitter showed a maximum brightness of 250 cd/m(2) under 11 V. The higher brightness combined with the higher current density was attributed to the effective hole injection and/or hole transport in the TPA-PPV-based device. © 2005 Elsevier Ltd. All rights reserved.

    DOI

  • Heat-resistant oxygen-carrying hemoproteins consist of recombinant xylanases and synthetic iron(II) porphyrin

    T Komatsu, S Ishihara, E Tsuchida, H Nishide, C Morokuma, S Nakamura

    BIOMACROMOLECULES   6 ( 3 ) 1489 - 1494  2005.05  [Refereed]

     View Summary

    Synthetic iron(II) porphyrin (FeP) is equivalently incorporated into recombinant Thermotoga maritima xylanase B (TMX; family F/10 of glycoside hydrolase), producing a heat-resistant artificial hemoprotein (TMX-FeP) that can bind and release oxygen (O-2) in aqueous medium (pH 7.3, 25 ° C) in the same manner as hemoglobin and myoglobin. The oxygenated species was sufficiently stable; the half-lifetime against the ferric state (τ(1/2)) was 5 h. This O-2-carrying hemoprotein showed a high degree of thermal stability over a wide range of temperatures up to 90 ° C (τ(1/2) = 5 min at 90 ° C and 9 min at 75 ° C). Dictyoglomus thermophilum xylanase B (DTX; family G/11) also incorporates FeP, and DTX-FeP showed identical O-2-binding parameters and thermostability. TMX-FeP is capable of catalyzing the β-1,4-D-xylan hydrolysis reaction. Its larger K-m value compared to that of TMX itself suggested competitive FeP binding to the active site of the host enzyme.

    DOI

  • Poly(thiaheterohelicene): A stiff conjugated helical polymer comprised of fused benzothiophene rings

    T Iwasaki, Y Kohinata, H Nishide

    ORGANIC LETTERS   7 ( 5 ) 755 - 758  2005.03  [Refereed]

     View Summary

    A novel helical aromatic polymer comprised of fused benzothiophene rings, poly(thiaheterohelicene), was synthesized via an intramolecular ring-closing reaction with a controlled helicity to one-sided bias. The synthetic helicity control involved the induction of the helical conformation and its fixation. The ladder polymer showed both an extended pi-conjugation and planarity and a very stiff helical structure.

    DOI

  • Reversible oxygen binding to the polymeric cobalt tetraazaporphyrin complex and oxygen-facilitated transport through its membrane

    H Shinohara, H Shibata, D Wohrle, H Nishide

    MACROMOLECULAR RAPID COMMUNICATIONS   26 ( 6 ) 467 - 470  2005.03  [Refereed]

     View Summary

    A membrane of a cobalt tetraazaporphyrin polymer complex was prepared with a nanometer thickness and used as an oxygen-facilitated transport membrane. Rapid and reversible oxygen binding to the cobalt tetraazaporphyrin complex with a polymeric imidazole ligand was observed at low temperature. Oxygen transport through the membrane was facilitated and a high (oxygen/nitrogen) permselectivity of 28 was obtained.

    DOI

  • The photoresponse of a molybdenum porphyrin makes an artificial gill feasible

    K Nagase, U Hasegawa, F Kohori, K Sakai, H Nishide

    JOURNAL OF MEMBRANE SCIENCE   249 ( 1-2 ) 235 - 243  2005.03  [Refereed]

     View Summary

    An artificial gill has been developed that transfers oxygen from water to air, using oxo-molybdenum(IV)5,10,15,20-tetramesitylporphyrin ((MoO)-O-IV(tmp)) dissolved in o-xylene as an oxygen carrier solution and the energy of visible light. The oxygen partial pressure in the oxygen carrier solution is changed by photo-irradiation to enhance both the oxygen uptake from water and the oxygen release to air. The ratio of the oxygen mass transfer coefficient of the oxygen carrier solution to that of water is 0.746 for oxygen uptake and 0.654 for oxygen release. In designing a large-scale artificial gill for supplying oxygen to a closed space underwater such as submerged vessel, the required membrane surface area, the seawater flow rate and the reservoir tank volume were 123 m(2), 0.00533 m(3) s(-1), and 5.06 m(3), respectively. These values increased as the oxygen partial pressure of seawater decreased. However, the high partial pressure of oxygen required for human respiration (20.0 kPa) can be provided in a closed space even from seawater with an oxygen partial pressure as low as 10.0 kPa. This newly developed artificial gill may be useful for deep sea activities, such as underwater exploration, marine research and underwater habitation. (C) 2004 Elsevier B.V. All rights reserved.

    DOI

  • Facile preparation of helical ladder-type polymers with fused phenoxathiine rings

    T Iwasaki, Y Tsukahara, H Nishide

    CHEMISTRY LETTERS   34 ( 2 ) 164 - 165  2005.02  [Refereed]

     View Summary

    Poly(3-chiral methylsulfinyl-1,2-phenyleneoxide) was synthesized, and the regioselective intramolecular ring-closing of the pendant sulfoxide on the polymer formed the corresponding helical ladder structure comprising of a fused phenoxathiine ring. The CD of the ladder polymer gave a Cotton effect which was caused by the chirality of the pendant group.

    DOI

  • Rapid responsible optical CO2 sensor of the combination of colorimetric change of ホア-naphtholphthalein in poly(trimethylsiliylpropyne) layer and internal reference fluorescent porphyrin in polystyrene layer

    Amao, Y, Komori, T, Nishide, H

    Reactive and Functional Polymers   63 ( 1 ) 35 - 41  2005  [Refereed]

  • Synthesis of dendritic, non-kekule-, and nondisjoint-type trophenylmethanes terminated with galvinoxyl radicals

    E Fukuzaki, N Takahashi, S Imai, H Nishide, A Rajca

    POLYMER JOURNAL   37 ( 4 ) 284 - 293  2005  [Refereed]

     View Summary

    A series of triphenylmethanes terminated with (a) hydrogalvinoxyl(s), bis(4-tert-butylphenyl)-(4-hydrogalvinoxylphenyl)methoxymethane lad, tris(4-hydrogalvinoxylphenyl)methoxymethane 2ad, and tris{4-[bis(4-hydrogalvinoxylphenyl)methoxymethyl]phenyl}methoxymethane 3ad, were prepared and oxidized to the corresponding galvinoxyl radicals, 1af, 2af, and 3af, which have one, three, and six galvinoxyl radical(s), respectively. Chemical reduction of the galvinoxyl radicals with a Na/K alloy gave stable intermediates, i.e., the tetraanion, decaanion, and docosaanion. The tetraanion was oxidized with an equimolar amount of iodine at ca. 170 K to the galvinoxyl radical-combined triphenylmethyl radical 1cf The ESR signal of the biradical at room temperature indicated an exchange interaction between the two radicals. The spectrum at 140 K had a zero-field splitting and Delta M-S = +/- 2 transition signal at half-field, which are characteristic of a multiplet species.

    DOI

  • Synthesis and magnetic property of poly[bis(4-methoxyphenyl)aminiumacetylene]s

    H Murata, D Miyajima, R Takada, H Nishide

    POLYMER JOURNAL   37 ( 11 ) 818 - 825  2005  [Refereed]

     View Summary

    Poly[bis(4-methoxyphenyl)aminiumacetylene]s 1(+) were designed and synthesized as a pi-conjugated polymer bearing multiple aminium radicals. Bis(4-methoxyphenyl)aminoacetylene and 1-methyl-2-bis(4-methoxyphenyl)aminoacetylene were synthesized and polymerized with a metathesis catalyst to yield poly [bis(4-methoxyphenyl)aminoacetylene] 1a and poly[1-methyl-2-bis(4-methoxyphenyl)aminoacetylene] 1b, respectively. The oxidation of 1 with SbCl5 gave the corresponding aminium polyradicals 1(+). The introduction of a methyl group onto the polyacetylene backbone in 1b(+) significantly enhanced the chemical stability or life-time of the poly(aminium radical). The high-spin ground state with an average S (spin quantum number) = 4/2 for 1b(+) was proven by magnetic susceptibility, magnetization, and ESR measurements.

    DOI

  • A helical ladder polymer: Synthesis and magnetic circular dichroism of poly[phenylene-4,6-bis(methylsulfonio)-1,3-diyl triflate]

    T Iwasaki, K Katayose, Y Kohinata, H Nishide

    POLYMER JOURNAL   37 ( 8 ) 592 - 598  2005  [Refereed]

     View Summary

    A helical ladder polymer composed of a fused-benzothiophenium ring was synthesized via the intramolecular ring-closing reaction of the methylsulfoxide-substituted poly(1,3-phenylene). The precursor polymer was prepared by the palladium-catalyzed polymerization of 1,3-dibromobenzene and 1,3-phenylenebisborate and the following quantitative oxidation. The intramolecular ring-closing of the precursor polymer yielded poly [phenylene-4,6-bis(methylsulfonio)- 1,3-diyl triflate]. The polymer structure did not involve any structural defects based on NMR analysis, which was supported by the model dimers and the control reaction using the monomeric analogues. The obtained polymer is one of the new poly(thiaheterohelicene)s. Magnetic circular dichroism of the polymer suggested an electron transition ascribed to the fused-ring structure.

    DOI

  • Submicrometer-sized polystyrene particles packing on silicon microfabricated substrate

    Tanaka, M, Shimamoto, N, Tanii, T, Ohdomari, I, Nishide, H

    Materials Research Society Symposium Proceedings   901   330 - 335  2005  [Refereed]

  • Application of pressure-sensitive paints to low-pressure range

    T Niimi, M Yoshida, M Kondo, Y Oshima, H Mori, Y Egami, K Asai, H Nishide

    JOURNAL OF THERMOPHYSICS AND HEAT TRANSFER   19 ( 1 ) 9 - 16  2005.01  [Refereed]

     View Summary

    The pressure-sensitive paint (PSP) technique has potential as a powerful diagnostic tool for measurements in the high Knudsen number regime because it is based on luminescence of molecules. Three types or PSP [two composed of organic dye and polymer (luminophore/binder), platinum octaethylporphyrin (PtOEP)/silicone polymer (GP197) and platinumtetrakis (pentafluorophenyl) porphyrin (PtTFPP)/poly[1-(trimethylsilyl)-propyne] [poly(TMSP)], and the other ruthenium II tris (4,7-diphenyl-1, 10-phenanthrolin chloride (Bath-Ru) adsorbed on anodized aluminum] are applied to the rarefied gas flow mainly lower than 150 Pa (about 1 torr) to examine fundamental properties, such as pressure/temperature sensitivity time response of luminescence. and so on. The results show PtTFPP/poly(TMSP) to be the most suitable PSP among them for application in the low-pressure range because it has very high and linear sensitivity against oxygen pressure. However, temperature sensitivity of PtTFPP/poly(TMSP) is not negligible, and a correction of temperature is required for quantitative pressure measurement with high accuracy. Finally, pressure distribution of a surface on which a low-density supersonic freejet impinges is measured by the PSP.

  • Radical polymer and its nano-sized thin film device

    Y Yonekuta, T Kurata, H Nishide

    JOURNAL OF PHOTOPOLYMER SCIENCE AND TECHNOLOGY   18 ( 1 ) 39 - 40  2005  [Refereed]

  • Rearrangement of hollow fibers for enhancing oxygen transfer in an artificial gill using oxygen carrier solution

    Nagase, K, Kohori, F, Sakai, K, Nishide, H

    Journal of Membrane Science   254 ( 39448 ) 207 - 217  2005  [Refereed]

  • Effect of a fluoro-coating on oxygen transport performance and lifetime of a polymer-cobaltporphyrin membrane

    BQ Shentu, ZX Weng, ZR Pan, H Nishide

    CHEMICAL JOURNAL OF CHINESE UNIVERSITIES-CHINESE   26 ( 1 ) 162 - 165  2005.01  [Refereed]

     View Summary

    A membrane having a long lifetime was prepared by spin-coating a perfluororesin on the polymer-cobaltporphyrin membrane, while the coating had no significant effect on the oxygen permeability and oxygen/nitrogen selectivity of the membrane. The oxygen-binding properties of CoP and facilitated oxygen transport of the coated membrane were also studied. It was found that CoP fixed even in the coated membrane had rapid and reversible oxygen-binding properties in response to the partial oxygen pressures and the apparent oxygen-binding equilibrium constants of CoP were not influenced by the coating. Oxygen permeation was selectively facilitated with CoP fixed in the perfluororesin-coated membrane, whereas the water vapor permeability was significantly suppressed in comparison with that of the uncoated membrane. With increasing the coating thickness, the oxygen permeability coefficients slightly decreased, but the water vapor permeability coefficients significantly decreased. The lifetime of the CoP as an oxygen-carrier in the perfluororesin-coated membrane was prolonged, which was attributed to the hydrophobic property of the coating.

  • Dendron-combined poly(4-diphenylaminium-1,2-phenylenevinylene): An isolated multiplet molecule

    H Murata, Y Yonekuta, H Nishide

    ORGANIC LETTERS   6 ( 26 ) 4889 - 4892  2004.12  [Refereed]

     View Summary

    [Graphics]
    Poly[4-(N,N-bis(4-3,5-bis(3,5-bis(benzyloxy)benzyloxy)benzyloxyphenyl)amino)-1,2-phenylenevinylene] was prepared by the palladium-catalyzed polycondensation of the dendron-coupled bromostyrene and oxidized to yield the corresponding poly(aminium cationic radical): The dendron-combined polyradical molecule displayed both a substantial chemical stability and a multiplet state without any intermolecular interaction.

    DOI

  • Electron-transfer kinetics of nitroxide radicals as an electrode-active material

    T Suga, YJ Pu, K Oyaizu, H Nishide

    BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN   77 ( 12 ) 2203 - 2204  2004.12  [Refereed]

     View Summary

    The electron-transfer rate constants of nitroxide derivatives, 4-(N-t-butyl-N-oxylamino)-t-butylbenzene, 4-(N-t-butyl-N-oxylamino)methoxybenzene, and 2,2,6,6-tetramethylpiperidinyl-N-oxyl, were investigated by electrochemical methods, which demonstrated that these radicals can potentially be used as a high power-rate electrode-active material due to their fast electron-transfer process.

    DOI

  • Effect of the polyethyleneimine-cobalt complex on reduction current of oxygen

    BQ Shentu, ZX Weng, HY Nishide

    ACTA POLYMERICA SINICA   ( 6 ) 859 - 863  2004.12  [Refereed]

     View Summary

    The reversible oxygen-binding properties of the polyethyleneimine-cobalt (PEI-Co) complex and the effect of the PEI-Co complex on the reduction current of oxygen were studied. The color of the PEI-Co complex in the electrolyte solution changed on exposure to oxygen atmosphere, which was monitored by UV-visible absorption spectrometry. The UV-visible absorption spectra of the PEI-Co complex displayed a new adsorption band at 310 nm, with an isosbestic point at 280 nm. The spectral change was attributed to the reversible oxygen-adduct formation of the PEI-Co complex even in the electrolyte solution. The oxygen-binding equilibrium curve of the PEI-Co complex obeyed a Langmuir isotherm, to give the high oxygen-binding affinity ( p(50) = 0. 667 kPa). And the apparent dissociation rate constant of oxygen from the PEI-Co complex ( k(d) = 1.1 x 10(5) s(-1)) was also high. The aqueous solution of the PEI-Co complex that had rapid and reversible oxygen-binding properties functioned as an oxygen-enriching medium for oxygen electrode to enhance the diffusion-controlled current for the oxygen reduction. Based on the rapid release of oxygen from the PEI-Co complex, a high current was obtained for the reduction of oxygen in the presence of the PEI-Co complex, and the current increased with the increase of the concentration of the PEI-Co complex and the oxygen concentration in the atmosphere. The reduction current reached a saturated value near [ethyleneimine unit]/[Co] = 5, which suggested the structure of a six-coordinate mu-dioxo dinuclear complex [N5CoIII-O-2-(CoN5)-N-III]. A new type of oxygen-diffusion electrode for metal/air batteries and fuel cells is proposed using the oxygen-enriching material immobilized at the electrode surface.

  • Organic radical battery: nitroxide polymers as a cathode-active material

    H Nishide, S Iwasa, YJ Pu, T Suga, K Nakahara, M Satoh

    ELECTROCHIMICA ACTA   50 ( 2-3 ) 827 - 831  2004.11  [Refereed]

     View Summary

    Purely organic-derived nitroxide radicals, including their polymer derivative, poly(2,2,6,6-tetramethylpiperidinyloxy methacrylate) (PTMA), were characterized as a new class of cathode-active materials for lithium batteries. PTMA was stable at ambient conditions, had a tunable solubility and processability, and could undergo thermal runaway without any odor and ash. The nitroxide radicals displayed a reversible and very rapid redox to form their oxoammonium salts, which enabled a high power-rate performance during the charge and discharge process of the battery. (C) 2004 Elsevier Ltd. All rights reserved.

    DOI

  • 3-Dithiolthione-substituted polythiophene and its redox activities

    Takemura, I, T Iwasaki, S Takeoka, H Nishide

    CHEMISTRY LETTERS   33 ( 11 ) 1482 - 1483  2004.11  [Refereed]

     View Summary

    We synthesized 3-dithiolthione-substituted polythiophene, poly [3-(1',2-dithiol-3'-thione-4'-yl)thiophene], by cyclization reaction of poly [3-bis(methoxycaronyl)methyl thiophene]. Its redox behavior and electronic states showed that the oxidation of the polythiophene followed the oxidation of the dithiolthione ring to the radical cation of the dithiolthione ring.

    DOI

  • Triphenylamine- and oxadiazole-substituted poly(1,4-phenylenevinylene)s: Synthesis, photo-, and electroluminescent properties

    YJ Pu, T Kurata, M Soma, J Kido, H Nishide

    SYNTHETIC METALS   143 ( 2 ) 207 - 214  2004.06  [Refereed]

     View Summary

    Novel triphenylamine- and oxadiazole-substituted poly(1,4-phenylenevinylene)s (PPV) or CN-PPV (P1-4) were synthesized by the Wittig-Horner. Knoevenagel. and Gilch type polymerization. The polymers exhibited good solubility in common organic solvents, relatively high photoluminescent (PL) efficiency, and high HOMO level for ca. -5.1 eV. The simple double-layer devices of triphenylamine-PPV A1, ITO/PEDOT: PSS/P1/Cs/Al, exhibited a very high luminance of 5 10 cd/m(2) under a low driving voltage of 3 V, demonstrating the effectiveness of triphenylamine moiety as a substituent of PPV derivatives for a light-emitting polymer. Triphenylamine-CN-PPV (P2) exhibited bipolar reversible redox in CV. The bipolar type of PPVs, P2 and triphenylamine-oxadiazole-PPV (P3), showed lower luminance and efficiency than those of the p-type of PPV (P1). (C) 2004 Elsevier B.V. All rights reserved.

    DOI

  • Electrocatalysis for dioxygen reduction by a mu-oxo decavanadium complex in alkaline medium and its application to a cathode catalyst in air batteries

    EL Dewi, K Oyaizu, H Nishide, E Tsuchida

    JOURNAL OF POWER SOURCES   130 ( 1-2 ) 286 - 290  2004.05  [Refereed]

     View Summary

    The redox behavior of a decavanadium complex [(V=O)(10)(mu(2)-O)(9)(mu(3)-O)(3)(C5H7O2)(6)] (1) was studied using cyclic voltammetry under acidic and basic conditions. The reduction potential of V(V) was found at less positive potentials for higher pH electrolyte solutions. The oxygen reduction at complex I immobilized on a modified electrode was examined using cyclic voltammetry and rotating ring-disk electrode techniques in the I M KOH solutions. On the basis of measurements using a rotating disk electrode (RDE), the complex I was found to be highly active for the direct four-electron reduction of dioxygen at -0.2 V versus saturated calomel electrode (SCE). The complex I as a reduction catalyst of O-2 with a high selectivity was demonstrated using rotating ring-disk voltammograms in alkaline solutions. The application of complex I as an oxygen reduction catalyst at the cathode of zinc-air cell was also examined. The zinc-air cell with the modified electrode showed a stable discharge potential at approximately I V with discharge capacity of 80 mAh g(-1) which was about five times larger than that obtained with the commonly used manganese dioxide catalyst. (C) 2004 Published by Elsevier B.V.

    DOI

  • Microparticles of poly(methacrylic acid) - Gadolinium ion complex and their magnetic force microscopic images

    T Michinobu, N Sasao, H Nishide

    JOURNAL OF POLYMER SCIENCE PART A-POLYMER CHEMISTRY   42 ( 8 ) 1912 - 1918  2004.04  [Refereed]

     View Summary

    Modified poly(methacrylic acid) microparticles complexed with gadolinium(III) (Gd3+) ions were prepared in 100 nm. The emulsion terpolymerization of methacrylic acid, ethyl acrylate, and allyl methacrylate and the following complexation with Gd3+ ions yielded the polymer particles with different Gd3+ ion contents. Potentiometric titration of the complexation of the particle with Gd3+ ions indicated the formation of a very stable tris-carboxylate coordinate complex with the Gd3+ ion. Electron spin resonance and IR spectra of the complexed particles were dependent on the Gd3+ ion content and the coordination environment in each particle. The microparticles dispersed on a mica substrate were subjected to atomic force microscopy (AFM), followed by magnetic force microscopy (MFM). AFM showed 100-nm-sized and monodispersed spherical images. The following MFM clearly provided strong magnetic responses exactly on the same particle positions, of which the images were also dependent on the Gd3+ ion content in the particle. (C) 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 1912-1918, 2004.

    DOI

  • Selective deposition of polystyrene nanoparticles in a nanoetchpit array on a silicon substrate

    M Tanaka, T Hosaka, T Tanii, Ohdomari, I, H Nishide

    CHEMICAL COMMUNICATIONS   10 ( 8 ) 978 - 979  2004.04  [Refereed]

     View Summary

    Nanometer-sized polystyrene particles were selectively deposited by interfacial tension in nanometer-sized etchpit arrays made on a silicon substrate.

    DOI

  • A high-spin and durable polyradical: Poly(4-diphenylaminium-1,2-phenylenevinylene)

    H Murata, M Takahashi, K Namba, N Takahashi, H Nishide

    JOURNAL OF ORGANIC CHEMISTRY   69 ( 3 ) 631 - 638  2004.02  [Refereed]

     View Summary

    A purely organic, high-spin, and durable polyradical molecule was synthesized: It is based on the non-Kekule- and non-disjoint design of a pi-conjugated poly(1,2-phenylenevinylene) backbone pendantly 4-substituted with multiple robust arylaminium radicals. 4-NN-Bis(4-methoxy- and -tert-butylphenyl)amino-2-bromostyrene 5 were synthesized and polymerized with a palladium-phosphine catalyst to afford the head-to-tail-linked polyradical precursors (1). Oxidation of 1 with the nitrosonium ion solubilized with a crown ether gave the aminium polyradicals (1(+)) which were durable (half-life > 1 month) at room temperature in air. A high-spin ground state with an average S = (4.5)/2 for 1a(+) was proved even at room temperature by magnetic susceptibility, magnetization, ESR, and NMR measurements.

    DOI

  • Electroreduction of oxygen at a Pt/C-modified electrode with a cobaltporphyrin complex

    B Shentu, K Oyaizu, H Nishide

    BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN   77 ( 2 ) 401 - 405  2004.02  [Refereed]

     View Summary

    Cobalt complexes that reversibly bind and release O-2 functioned as O-2 carriers, or O-2-enriching media, at the surface of a cathode to enhance the current for the reduction of O-2. The effect of the cobalt complex to accumulate O-2 was evidenced by the higher open-circuit potential, which reflected the equilibrated concentration of O-2 at the electrode surface. The combination of the cobalt complex and the conventional Pt/C catalyst resulted in a significant increase in the steady-state Current for the four-electron reduction of O-2, particularly at small overpotentials where typical fuel cells operate, based on the facilitated transport of O-2 from the atmosphere to the catalyst at the electrode Surface.

    DOI

  • Stability of porphyrin-calix[4]arene complexes analyzed by electrospray ionization mass spectrometry

    S Arai, S Ishihara, S Takeoka, H Ohkawa, T Shibue, H Nishide

    RAPID COMMUNICATIONS IN MASS SPECTROMETRY   18 ( 18 ) 2065 - 2068  2004  [Refereed]

     View Summary

    The stability of some porphyrin-calix[4]arene sodium-ion complexes were determined by a collision-activated decomposition (CAD) method utilizing electrospray ionization mass spectrometry (ESI-MS). Comparing the values of E-1/2, the collision energy at which the relative intensity of the complex ion is 0.5, we found that the porphyrin-calix[4]arene complex with the higher value of E-1/2 corresponded to that with the larger association constant (K-ass), as measured by H-1-NMR in CDCl3. Both our ESI-MS and NMR studies proved that the number of hydrogen bonds and the rigidity of the calix[4]arene stabilized the complex. The ESI-MS technique could be successful in screening the binding affinity in host-guest systems with a small amount of sample. Copyright (C) 2004 John Wiley Sons, Ltd.

    DOI

  • Preparation of a tetraphenylporphyrinatocobalt(II)-poly(3,4azopyridylene) complex and its oxygen enrichment effect at an oxygen electrode

    B Shentu, K Oyaizu, H Nishide

    JOURNAL OF MATERIALS CHEMISTRY   14 ( 22 ) 3308 - 3311  2004  [Refereed]

     View Summary

    The reversible oxygen-binding properties of tetraphenylporphyrinatocobalt(II) (CoTPP) complexed with poly(3,4-azopyridylene) ( PAP) were established. The CoTPP complexes functioned as oxygen carriers at the surface of a cathode to enhance the current for the reduction of oxygen. PAP was synthesized by the oxidative polymerization of 3,4-diaminopyridine in a DMF solution at 25degreesC using a Cu/pyridine catalyst. The combination of the CoTPP complex and the conventional Pt/C catalyst resulted in a significant increase in the steady-state current for the four-electron reduction of O-2, particularly at small overpotentials where typical fuel cells operate, based on the facilitated transport of O-2 from the atmosphere to the catalyst at the electrode surface.

    DOI

  • Engineering thermoplastic the watery way

    Nishide, H

    Chemical Engineer   ( 757 ) 22  2004  [Refereed]

  • Oxidative polymerization of 2,6-dimethylphenol to form poly(2,6-dimethyl-1,4-phenyleneoxide) in water

    K Saito, T Tago, T Masuyama, H Nishide

    ANGEWANDTE CHEMIE-INTERNATIONAL EDITION   43 ( 6 ) 730 - 733  2004  [Refereed]

  • Synthesis of poly(ethynylplatinumporphyrin) and its application as an oxygen pressure-sensitive paint

    H Hah, T Sakai, K Asai, H Nishide

    MACROMOLECULAR SYMPOSIA   204   27 - 35  2003.11  [Refereed]

     View Summary

    5-(4-Trimethylsilyethynylphenyl)-10,15,20-triphenyiplatinumporphyrin was synthesized and copolymerized with trimethylsilylpropyne to give a new high-molecular-weight porphyrin polymer. The polymer formed a smooth and tough coating on many types of surfaces. The coating showed a strong blue luminescence from the platinumporphyrin residue which was quenched in the presence of oxygen. The relationship of the luminescence intensity vs oxygen pressure displayed a remarkably high pressure sensitivity in the low oxygen pressure area, which was ascribed to the high oxygen permeability of the polymer.

  • Facilitated oxygen transport membranes of picket-fence cobaltporphyrin complexed with various polymer matrixes

    BQ Shentu, H Nishide

    INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH   42 ( 24 ) 5954 - 5958  2003.11  [Refereed]

     View Summary

    A series of membranes having a selective and reversible oxygen-binding capacity were prepared by complexing picket-fence cobaltporphyrin (CoP) as an oxygen carrier with various polymer matrixes. The oxygen-absorption isotherm and oxygen permeation in and through the membranes were properly analyzed by dual-mode models to give the physical solubility coefficient of oxygen (k(D)), the physical diffusion coefficient of oxygen through the membrane (D-D), and the apparent diffusion coefficient of oxygen for hopping between fixed carriers (D-C). The oxygen-binding equilibrium constant (K) of CoP was independent of the polymer matrix species. The D-C value was smaller than the D-D value, but the D-C/D-D ratio still remained in the range of 1/5-1/50, indicating that CoP fixed in the membrane reversibly binds oxygen and facilitates oxygen transport.

    DOI

  • A duplex of tetra(2-pyridyl)porphyrin and tetrahydroxylcalix[4]arene

    H Ohkawa, S Arai, S Takeoka, T Shibue, H Nishide

    CHEMISTRY LETTERS   32 ( 11 ) 1052 - 1053  2003.11  [Refereed]

     View Summary

    meso-Tetra(2-pyridyl)porphyrin forms a duplex with tetrahydroxylealix[4]arene via triplicate or quadruple hydrogen bonds, to provide a capping structure on the porphyrin plane.

  • Electronic transport of benzothiophene-based chiral molecular solenoids studied by theoretical simulations

    K Tagami, M Tsukada, Y Wada, T Iwasaki, H Nishide

    JOURNAL OF CHEMICAL PHYSICS   119 ( 14 ) 7491 - 7497  2003.10  [Refereed]

     View Summary

    By the density-functional-derived tight-binding method, the electronic transport properties of two types of benzothiophene-based molecular wires, i.e., the linear and helical molecular wires have been investigated. In the molecular bridge system where these molecules are connected to the gold electrodes by S-Au bonds, the transmission peaks are found to lie at the energies somewhat lower than 0.5 eV below the Fermi level for both cases. Thus the conductances of both types of wires for the bias voltage less than 1.0 V are not so large without doping. Upon iodine doping, however, the new transmission peaks are found to appear around the Fermi level, particularly in the case of helical wires. It means that the conductances of the helical wires are expected to be improved dramatically by the chemical doping. Therefore, the doped helical molecular wires are predicted to work as molecular solenoids even under lower bias voltages. Next, the applicability of the current-induced magnetic field generated in such a molecular solenoid is considered. As an example, we propose a novel helical molecule where the hydrogen atoms connected to the inner C-C bonds of the helix are substituted by some kind of radicals. In this case the current-induced field can control the alignment of the radical spin orientations. (C) 2003 American Institute of Physics.

    DOI

  • Depolymerization of poly(2,6-dimethyl-1,4-phenylene oxide) under oxidative conditions

    K Saito, T Masuyama, K Oyaizu, H Nishide

    CHEMISTRY-A EUROPEAN JOURNAL   9 ( 17 ) 4240 - 4246  2003.09  [Refereed]

     View Summary

    Depolymerization of an engineering plastic, poly(2,6-dimethyl-1,4-phenylene oxide) (PPO), was accomplished by using 2,6-dimethylphenol (DMP) under oxidative conditions. The addition of an excess amount of DMP to a solution of PPO in the presence of a CuCl/pyridine catalyst yielded oligomeric products. When PPO (M-n = 1.0 X 10(4), M-w/M-n = 1.2) was allowed to react with a sufficient amount of DMP, the molecular weight of the product decreased to M-n = 4.9 X 10(2) (M-w/M-n = 1.5). By a pro-longed reaction with the oxidant, the oligomeric product was repolymerized to produce PPO essentially identical to the starting material, making the oligomer useful as a reusable resource. During the depolymerization reaction, an intermediate phenoxyl radical was observed by ESR spectroscopy. Kinetic analysis showed that the rate of the oxidation of PPO was about 10 times higher than that of DMP. These results show that a monomeric phenoxyl radical attacks the polymeric phenoxyl to induce the redistribution via a quinone ketal intermediate, leading to the substantial decrease in the molecular weight of PPO, which is much faster than the chain growth.

    DOI

  • Preparation of non-Kekule- and nondisjoint-type aromatic polyamines by palladium-catalyzed polycondensation and their poly(cationic radical)s

    T Michinobu, J Inui, H Nishide

    POLYHEDRON   22 ( 14-17 ) 1945 - 1949  2003.07  [Refereed]

     View Summary

    A series of triarylamine polymers were prepared by palladium-catalyzed polycondensation. Extension of the pi-conjugation was analyzed by UV and electrochemical measurements, which revealed the degree of off-coplanarity in the polymer framework. Chemical oxidation of the polymer with NOPF6 gave the corresponding poly(aminium cationic radical). The ESR signal at room temperature indicated an exchange interaction between the radicals in the polymer. The spectrum recorded at 12 K displayed a DeltaM(s) = +/-2 transition signal at half-field, which was characteristic of multiplet species. (C) 2003 Elsevier Science Ltd. All rights reserved.

    DOI

  • m-phenylene-linked aromatic poly(aminium cationic radical)s: Persistent high-spin organic polyradicals

    T Michinobu, J Inui, H Nishide

    ORGANIC LETTERS   5 ( 12 ) 2165 - 2168  2003.06  [Refereed]

     View Summary

    [GRAPHICS]
    High molecular weight and networked aromatic polyamines prepared by palladium-catalyzed polycondensation were oxidized to yield the corresponding poly(aminium cationic radical)s, which displayed a substantial stability and an intramolecular ferromagnetic interaction of eight or nine spins.

    DOI

  • Cationic polysulfonium membrane as separator in zinc-air cell

    EL Dewi, K Oyaizu, H Nishide, E Tsuchida

    JOURNAL OF POWER SOURCES   115 ( 1 ) 149 - 152  2003.03  [Refereed]

     View Summary

    A polyelectrolyte containing a sulfonium cation, poly(methylsulfonio-1,4-phenylenethio-1,4-phenylene trifluoromethanesulfonate) (1) was tested as a separator in a zinc-air cell. In comparison with the commercially available separators such as polypropylene, polysulfonium 1 was highly effective to prevent cation permeation from the anode to cathode and effectively increased the capacity six-fold greater than that of polypropylene during discharge. This phenomenon was explained by the ion-exchange process of the membrane 1, which showed an anion-permselectivity toward OH- at low KOH aqueous solution concentrations (<1 M). (C) 2003 Elsevier Science B.V. All rights reserved.

    DOI

  • Magnetic force microscopy images of a nanometer-sized purely organic high-spin polyradical

    M Miyasaka, Y Saito, H Nishide

    ADVANCED FUNCTIONAL MATERIALS   13 ( 2 ) 113 - 117  2003.02  [Refereed]

     View Summary

    Magnetic force microscopy (MFM) was applied to study both the molecular image and the magnetic response of pi-conjugated, non-Kekule-, and nondisjoint-type poly(1,2-phenylenevinylene) (nondisjoint refers to a molecule in which non-bonding molecular orbitals share the same region in the molecule and a multiplet ground state is significantly stabilized) networks bearing 4-substituted di-tert-butylphenoxyl moities. The polyphenoxyl radicals 1 with molecular weights of 2.6, 9.3, and 32 kDa have a substantial stability even at room temperature and in air, and molecular sizes in the nanometer range of 10, 20, and 35 nm, respectively, with a disk-like shape. The MFM clearly shows a magnetic gradient response exactly on the position of the polyradical molecule dispersed on a graphite surface. The MFM molecular image of polyradical samples with different molecular weights and spin concentrations was examined as a nanoscale and single-molecular-based magnetic dot.

  • Irreversible oxidation of porphyrinato cobalt(II) (TPPCo) and the effect of fluorine-containing polymers on the lifetime of TPPCo complex membranes

    BQ Shentu, ZX Weng, H Nishide

    ACTA POLYMERICA SINICA   ( 1 ) 120 - 123  2003.02  [Refereed]

     View Summary

    The oxidizing process and the oxygen-binding lifetime of, 5, 10, 15, 20-tetra (o-pivalamidophenyl)- porphyrinato cobalt(II) (TPPCo) complexed with poly (vinylimidazole-co-fluoropentyl methacrylate) (PFIm) Were studied,and the mechanism and dynamics of irreversible oxidation of TPPCo were discussed. The TPPCo displayed a reversible change in the UV-visible absorption spectrum from the deoxy form (lambda(max) = 530 nm) to the oxygen-binding one (lambda(max) = 548 nm) with an isosbestic point at 538 nm, in response to the partial oxygen pressure of the atmosphere. But the active TPPCo complex in the membrane was slowly changed, via the irreversible oxidation reaction in the open atmosphere, to the TPPCo (III) complex without the oxygen-binding ability, which could be monitored by the UV-visible absorption at lambda(max) = 548 nm. In the solid membrane state, water molecules in air may attack the TPPCo-bound dioxygen to yield a hydrodioxy radical and TPPCo ( III), which is the main reason that diminishes the oxygen-binding ability of the TPPCo complex and that of the membrane. The half-lifetime (tau) of the TPPCo complex as an oxygen earner was measured by allowing the TPPCo-PFIm membrane to stand in dry air (environmental humidity 10%) in laboratory air (humidity ca. 50%) and in a water vapor atmosphere (humidity 95%) at room temperature, respectively. The decrease course of the active TPPCo complex approximately follows the first-order kinetics and gives the t values. The tau value of the PFIm-TPPCo complexed. membrane was as long as ca. 250 days even in the water vapor-saturated atmosphere. Under the same laboratory air condition, the lifetime of the PFIm-TPPCo membrane was much longer (ca. 13 times) than that of the reference non-fluoro membrane such as the membrane of TPPCo complexed with poly(octyl methacrylate-co-vinylimidazole). The hydrophobic property of the PFIm polymer is considered to suppress the irreversible oxidation of the active TPPCo carriers caused by water molecules and to significantly prolong the operational lifetime of the TPPCo complex membrane.

  • Magnetic force microscopic images of nanometer-sized polyradical particles

    T Michinobu, J Inui, H Nishide

    POLYMER JOURNAL   35 ( 1 ) 71 - 75  2003  [Refereed]

     View Summary

    Nanometer-sized polymer particles bearing 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) radicals were prepared. The emulsifier-free emulsion polymerization of methacrylic acid, methyl methacrylate, and methylenebisacrylamide and the following introduction of the TEMPO moiety produced polyradical particles with different spin concentrations. The TEMPO-combined particle was also prepared in one step by the anionic dispersion polymerization of 4-methacryloyloxy-2,2,6,6-tetramethylpiperidine-1-oxyl. The position and horizontal shape in the atomic and magnetic force microscopic images of the polyradical particle coincided with each other. The vertical scale of the magnetic image responded to the spin concentration of the particle. The particle bearing the radicals on its surface gave a hollow dot image.

  • Ladderlike ferromagnetic spin coupling network on a マ�-conjugated pendant polyradical

    Kaneko, T, Makino, T, Miyaji, H, Teraguchi, M, Aoki, T, Miyasaka, M, Nishide, H

    Journal of the American Chemical Society   125 ( 12 ) 3554 - 3557  2003  [Refereed]

  • Charge-transporting property of polymer films doped with organic stable radicals

    T Kurata, YJ Pu, J Kido, H Nishide

    JOURNAL OF PHOTOPOLYMER SCIENCE AND TECHNOLOGY   16 ( 2 ) 297 - 298  2003  [Refereed]

  • Ion-exchange and apparent diffusion coefficients within cationic polysulfonium coatings containing ferricyanide

    EL Dewi, H Nakano, K Oyaizu, H Nishide, E Tsuchida

    JOURNAL OF MACROMOLECULAR SCIENCE-PURE AND APPLIED CHEMISTRY   A40 ( 1 ) 37 - 47  2003  [Refereed]

     View Summary

    A cationic polyelectrolyte of various poly(arylenesulfonium salt)s were coated on the surface of glassy carbon electrodes with an incorporated ferricyanide anion from the electrolyte solutions. The apparent diffusion coefficients of Fe(CN)(6)(3-), that are electrostatically bound were determined by chronoamperometry, chronocoulometry and mediated electron transfer from the rotating disk voltammetry. The complex incorporated by the S-cationic polyelectrolyte shows a high diffusion coefficient for the polyelectrolyte of poly(methylsufonio-1,4-phenylenethio-1,4-phenylene trifluoromethanesulfonate). The diffusion of poly(arylenesulfonio triflate) depended on the ionic exchange of the S-cation which has an alkyl bond and the crystalline structure that influenced the electrostatic motion of the anion within the polyelectrolyte modified electrode.

    DOI

  • Oxidative polymerization to form poly(2,6-dimethyl-1,4-phenylene oxide) in water

    K Saito, T Masuvama, H Nishide

    GREEN CHEMISTRY   5 ( 5 ) 535 - 538  2003  [Refereed]

     View Summary

    An engineering plastic, poly(2,6-dimethyl-1,4-phenylene oxide) (PPO), was prepared via oxidative polymerization in water. 4-(2',6'-Dimethylphenoxy)-2,6-dimethylphenol was stirred in an aqueous alkaline solution with a metal catalyst to yield PPO with a molecular weight of three to four thousand. The formation of diphenoquinone as the side-product was inhibited in this reaction. This reaction is slow but also proceeded under oxygen without a catalyst. The oxidative polymerization in water provides a new polymerization procedure for PPO.

    DOI

  • Thermostable synthetic hemoproteins: Thermophilic xylanases hybridized with dioxygen-carrying meso-tetrakis(o-pivalamidophenyl)porphinatoiron(II) derivative

    T Komatsu, S Ishihara, E Tsuchida, H Nishide, C Morokuma, S Nakamura

    CHEMISTRY LETTERS   32 ( 1 ) 108 - 109  2003.01  [Refereed]

     View Summary

    meso-Tetrakis(alpha, alpha, alpha, alpha-o-pivalamidophenyl)porphinatoiron(II) derivative is incorporated into thermophilic xylanases, giving novel thermostable synthetic hemoproteins, which can form a dioxygen adduct in aqueous media (pH 7.3) at 90 degreesC.

  • meso-tetrakis[o-(N-methyl)pyridinium]porphyrin ensembles with axially coordinated cyclodextrin-penetrating phenethylimidazole: reversible dioxygen-binding in aqueous DMF solution

    T Komatsu, S Hayakawa, E Tsuchida, H Nishide

    CHEMICAL COMMUNICATIONS   9 ( 1 ) 50 - 51  2003  [Refereed]

     View Summary

    alpha-Cyclodextrin (alphaCD)-penetrating 2-methyl-1-phenethylimidazole coordinates to the zinc(II) and iron(II) complexes of meso-tetrakis[o-(N-methyl) pyridinium] porphyrinate, giving non-covalently linked alphaCD-porphyrin ensembles; the iron(II) complex can reversibly bind and release dioxygen in aqueous DMF solution.

    DOI

  • Synthesis of poly (vinylimidazole-co-fluoropentyl methacrylate) and oxygen-binding properties of its complex with cobaltporphyrin

    BQ Shentu, ZX Weng, H Nishide

    ACTA POLYMERICA SINICA   ( 5 ) 652 - 655  2002.10  [Refereed]

     View Summary

    Synthesis and characteristics of poly ( fluoropentyl methacrylate-co-vinylimidazole) (Flm), and oxygen-binding properties of its complex with meso-a, a, a, a-tetrakis(o-pivalamidophenyl) porphyrinato cobalt(II) (CoP) were studied. FIm was prepared by radical copolymerization of octafluoropentyl methacrylate with 1-vinylimdazole using azobis( isobutyronitrile) as the initiator. The vinylimidazole content and molecular weight of the Flm copolymer were determined to be 25 mol% and 5.0 x 10(4) by elemental analysis and GPC, respectively. Flm and CoP in solution were mixed to complex the imidazolyl residue of the copolymer with the fifth coordination site of CoP under nitrogen atmosphere to yield both an active and homogenous dispersed CoP for oxygen-binding. Oxygen-binding to the CoP-FIm complex was measured spectroscopically with a UV spectrophotometer. The CoP-FIm complex displayed a reversible change in the visible absorption spectrum from the deoxy form to the oxy or oxygen-binding one with an isosbestic point, in response to the partial oxygen pressure of the atmosphere. The oxygen-binding equilibrium curves obeyed a Langmuir isotherm, to give the oxygen-binding affinity p(50) (oxygen partial pressure at which half of the CoP binds with oxygen). Solvent has great effect on the oxygen-binding properties of the complex. The oxygen-binding affinity of the CoP-FIm complex in tetrahydrofuran was larger than that in N, N-dimethyl formamide solution. It is assumed that a N, N-dimethyl formamide molecule weakly coordinated to the sixth site (oxygen-binding site) of Cop to reduce the oxygen-binding affinity. On the other hand, the oxygen-binding site of the CoP complex could be maintained vacant in tetrahydrofuran before the oxygen-binding. The binding and dissociation rate constants of oxygen to and from the CoP (k(on) and k(off), respectively) for the CoP-FIm solution were large, which indicates a very rapid and reversible oxygen-binding by CoP.

  • Oxygen-binding to simple cobaltporphyrins combined with polyvinylmidazole

    H Shinohara, T Arai, H Nishide

    MACROMOLECULAR SYMPOSIA   186   135 - 139  2002.08  [Refereed]

     View Summary

    Reversible oxygen-binding was observed at low temperature for the poly(vinylimidazole-co-octyl methacrylate) complexes of the simple or planar cobaltporphyrins (CoP) such as cobalt-tetraphenylporphyrin and cobalt-octaethylporphyrin. The oxygen-binding affinity and rate constants were compared with those for the cobalt-picketfence porphyrin, a typical oxygen-carrier. The low oxygen-binding affinity for the CoP complexes was attributed to the enormously large oxygen-releasing rate constant.

  • Reduction of oxygen at an electrode modified by cobaltporphyrin liquid membrane

    BQ Shentu, K Oyaizu, H Nishide

    CHEMISTRY LETTERS   ( 7 ) 712 - 713  2002.07  [Refereed]

     View Summary

    The picket-fence cobaltporphyrin (Col?) having rapid and reversible oxygen-binding properties was employed to accumulate oxygen from a bulk solution to a diffusion layer at an electrode surface. Modification of a carbon electrode with a thin CoP liquid membrane resulted in a significant increase in the reduction current of oxygen, which proved to be a new type of modified electrode to reduce the diffusion resistance of oxygen from the bulk solution onto the electrode surface.

  • An optical sensing material for trace analysis of oxygen. Metalloporphyrin dispersed in poly(1-trimethylsilyl-1-propyne) film

    Y Amao, Okura, I, H Shinohara, H Nishide

    POLYMER JOURNAL   34 ( 6 ) 411 - 417  2002  [Refereed]

     View Summary

    A highly gas permeable polymer, poly(1-trimethylsilyl-1-propyne) (poly(TMSP)), was applied as a matrix of the optical oxygen sensor using the oxygen-induced luminescence quenching of octaethylporphyrin (OEP) platinum (PtOEP) or palladium complex (PdOEP). OEP complex was homogeneously dispersed in poly(TMSP) to give a mechanical tough film with thickness of 10 mum. The luminescence intensity of OEP complex dispersed in the poly(TMSP) films drastically decreased with an increase in oxygen concentration. The oxygen sensitivity of the film (I-0/I-100) was very high and estimated to be 225 for PtOEP and 121 for PdOEP, respectively. The Stern-Volmer constants of PtOEP and PdOEP dispersed in poly(TMSP) films are estimated to be 6.6 and 17%(-1), respectively. These results indicate that OEP metal complex dispersed in the poly(TMSP) films are novel optical sensing material for trace analysis of oxygen.

  • A study on fundamental properties of PSP in low pressure region

    Tomohide Niimi, Masaki Yoshida, Makoto Kondo, Yusuke Oshima, Hideo Mori, Yasuhiro Egami, Keisuke Asai, Hiroyuki Nishide

    Nippon Kikai Gakkai Ronbunshu, B Hen/Transactions of the Japan Society of Mechanical Engineers, Part B   68 ( 676 ) 3360 - 3368  2002  [Refereed]

     View Summary

    Recently pressure sensitive paint (PSP) has actively developed to measure continuous distribution of the surface pressure. However, the pressure range has been limited above l Torr (133.3 Pa) and there is no application to lower pressure range because the pressure sensitivity seems to be not so high in that range. In this study, we apply three types of PSP [two types are composed by organic dye and polymer (luminophore/binder)
    PtOEP/GP 197 and PtTFPP/poly(TMSP), and another one is Bath-Ru adsorbed on anodized aluminum] to the rarefied gas flow mainly lower than l Torr and examine those fundamental properties, such as pressure/temperature sensitivity and time response of luminescence and so on, leading to selection of the most suitable PSP among them for the low pressure range. Finally, the pressure distribution of the surface on which a low density supersonic free jet impinges is measured by the PSP.

    DOI

  • Poly(1,2-phenylenevinylene) ferromagnetically 3,5-bearing phenoxyl radicals

    H Nishide, M Miyasaka, R Doi, T Araki

    MACROMOLECULES   35 ( 3 ) 690 - 698  2002.01  [Refereed]

     View Summary

    A pi-conjugated but non-Kekule- and nondisjoint-type molecule, poly(1,2-phenylenevinylene) 3,5-disubstituted with pendant phenoxyl radicals (1a), was designed as a new high-spin organic polymer and synthesized by the head-to-tail coupling polymerization of 2-bromo-3,5-bis(3,5-di-tert-butyl-4-aceotoxyphenyl)styrene (3) using a palladium catalyst. The corresponding high-spin dimer model compound bearing four phenoxyl radicals (2a) was also synthesized. The stepwise radical formation in 1 and 2 was electrochemically studied. The ESR signal at DeltaM(s) = +/-2 indicated a triplet ground state for 1 and 2. However, the SQUID data revealed that the spin concentration and the average spin quantum number of la and 2a remained at ca. 0.5 spin/phenol unit and 2/2, respectively. A degradation at the vinylene bridge was suggested after the radical generation.

    DOI

  • Preparation and structure of the thin membrane of polymeric cobaltporphyrin complex

    H Shinohara, A Nakao, H Nishide

    KOBUNSHI RONBUNSHU   59 ( 10 ) 656 - 660  2002  [Refereed]

     View Summary

    A thin membrane of the cobalt-tetraphenylporphyrin (CoTPP) complex with the copolymer of octyl methacrylate and vinylimidazole (OIm) was successfully prepared with the thickness of 80similar to90 nm on a porous support membrane. The cobaltporphyrin-highly loaded membrane showed a high performance in the facilitated transport of oxygen. Homogeneous distribution of the CoTPP throughout the membrane and complexation with the imidazolyl residue of OIm with a 5-coordinated structure are described.

  • Novel pressure-sensitive paint for cryogenic and unsteady wind-tunnel testing

    K Asai, Y Amao, Y Iijima, Okura, I, H Nishide

    JOURNAL OF THERMOPHYSICS AND HEAT TRANSFER   16 ( 1 ) 109 - 115  2002.01  [Refereed]

     View Summary

    A novel pressure-sensitive paint (PSP) formulation suitable for use in cryogenic and unsteady wind-tunnel testing has been developed. This new PSP uses poly [1-(trimethylsilyl)-1-propyne] [poly(TMSP)] as a binder. Poly(TMSP) is a glassy polymer having extremely high gas permeability. Unlike the conventional polymer-based paints, PSP based on poly(TMSP) maintains oxygen sensitivity even at cryogenic temperatures and exhibits fast response time. This paint is sprayable on any model surface including stainless steel and ceramics. These capabilities allow us to apply this PSP to a cryogenic wind tunnel and a short-duration shock tunnel. To demonstrate the capability of poly(TMSP)-PSP for pressure measurements in a cryogenic wind tunnel, a circular-arc bump model and a delta wing model were tested in the National Aerospace Laboratory 0.1-m Cryogenic Wind Tunnel at 100 K. It has been verified that poly(TMSP)-PSP can provide high SIN pressure distribution data at high O-2 concentration. A comparison of the measured intensity data with the pressure tap measurements has suggested that the in situ calibration can be used to obtain quantitative pressure data. It was also demonstrated that poly(TMSP)-PSP could visualize the complex flowfield on a stainless steel delta wing, including primary and secondary separation vortices and their breakdown.

  • Electroluminescent properties of a triphenylamine-containing poly(phenylenevinylene)

    YJ Pu, M Soma, J Kido, H Nishide

    JOURNAL OF PHOTOPOLYMER SCIENCE AND TECHNOLOGY   15 ( 2 ) 259 - 260  2002  [Refereed]

  • Electroreduction of oxygen enriched in a [poly(ethyleneiminato)]cobalt(II) layer

    K Oyaizu, H Nakano, B Shentu, H Nishide

    JOURNAL OF MATERIALS CHEMISTRY   12 ( 10 ) 3162 - 3166  2002  [Refereed]

     View Summary

    An aqueous solution of a [poly(ethyleneiminato)]cobalt(II) complex that reversibly binds and releases O-2 functions as an O-2-enriching medium for an O-2 electrode to enhance the current for the uncatalyzed reduction of O-2. The effect of the electrochemically inactive cobalt complex is to supply reducible O-2 to the solution within the diffusion layer near the electrode by releasing the bound O-2 from the O-2 adduct, which contributes to a decrease in the diffusion layer thickness of O-2. Based on the rapid release of O-2 from the O-2 adduct, a diffusion-limited current is obtained for the reduction of O-2. The hypothetical concentration of the enriched O-2 supplied under pure diffusion control (i.e. unperturbed by the kinetics of the O-2 binding) is several times larger than that of the actual concentration of O-2 due to the higher solubility of the O-2 adduct than the physical solubility of O-2 in H2O at room temperature under an atmosphere of air. An insoluble membrane of a cobalt( II) complex with a cross-linked poly( ethyleneimine) ligand that has the ability to swell serves as an O-2-enriching material to concentrate O-2 from aqueous electrolyte solutions. A new type of O-2-diffusion electrodes for metal/air batteries and fuel cells is proposed using the O-2-enriching material immobilized at the electrode surface.

    DOI

  • Hyperbranched poly(phenylenevinylene) bearing pendant phenoxys for a high-spin alignment

    H Nishide, M Nambo, M Miyasaka

    JOURNAL OF MATERIALS CHEMISTRY   12 ( 12 ) 3578 - 3584  2002  [Refereed]

     View Summary

    2,6-Dibromo-4-(3',5'-di-tert-butyl-4'-acetoxyphenyl) styrene was polymerized in a one-pot reaction using a palladium catalyst, and subsequent hydrolysis and oxidation yielded the hyperbranched poly[(4-(3',5'-di-tertbutyl- 4'-ylooxyphenyl)-1,2,(6)-phenylenevinylene)], which three-directionally satisfies both an alternant but non-Kekule-type pi-conjugation and the ferromagnetic connectivity of the unpaired electrons of the pendant phenoxyl. The AFM image, unusually low solution viscosity, and low chemical reactivity of the phenol group indicated the polymer to have a highly branched and globular structure. In spite of the extremely crowded branching, pi-conjugation in the polymer skeleton was maintained, as indicated by photoelectron and EPR spectroscopies. The phenoxyl polymer even with a spin concentration of only 0.4 spin per monomer unit displayed an average S value of 3.

    DOI

  • Electroluminescence of poly(phenylenevinylene)s containing triphenylamine moieties in the main chain

    YJ Pu, M Soma, H Nishide, S Shirai, J Kido

    JAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS SHORT NOTES & REVIEW PAPERS   41 ( 1 ) 362 - 365  2002.01  [Refereed]

     View Summary

    A series of pi-conjugated polymers alternatively involving m-phenylenevinylene or p-phenylenevinylene and a triphenylamine moiety in the main chain, poly(triphenylamine-alt-phenylenevinylene)s, were synthesized and their optical and electrolumienscent properties were studied. Single-layer light-emitting diodes based on each polymer showed a strong blue-yellow-green emission ascribed to their band gaps, and exhibited small turn on voltages and large current densities. The device containing poly(4-methyltriphenylamine-alt-p-phenylenevinylene) (MPA-pPV) displayed a high brightness (640 cd/m(2) at 10 V). These results suggest that the polymers have a good charge transporting ability, and an electroluminescent property.

    DOI

  • Magnetic and electrical properties of poly(3-radical-substituted thiophene)s

    M Miyasaka, T Yamazaki, E Tsuchida, H Nishide

    POLYHEDRON   20 ( 11-14 ) 1157 - 1162  2001.05  [Refereed]

     View Summary

    Radical groups, tert-butylnitroxide, nitronyl nitroxide, and 2,6-di-tert-butylphenoxyl, were introduced at the 3-position of thiophene, and the thiophene derivatives were then polymerized to yield poly(3-radical-substituted thiophene)s. The acetoxyphenyl-substituted thiophene gave regio regular poly(3-phenol-subslituted thiophene) via oxidative polymerization with ferric chloride at low temperature, while the polymerization of the amine-substituted thiophenes did not proceed with any oxidizing agents under any reaction conditions. The phenoxyl-substituted polyradicals, 7 and 8, with spin concentrations of 0.30 and 0.25, respectively, displayed S values of 2/2 to 3/2 and 2/2, respectively, indicating an intramolecular ferromagnetic spin-coupling through the polythiophene backbone. The polyradicals, 7 and 8, themselves and the polyradical doped with iodine showed an electrical conductivity of 10(-5) and 10(-2 similar to) (-1) S cm(-1), respectively. (C) 2001 Elsevier Science Ltd. All rights reserved.

  • 5,4 '-Bis[bis(methoxyphenyl)amino]-2-methoxystilbene and its cationic biradical

    T Michinobu, E Tsuchida, H Nishide

    POLYHEDRON   20 ( 11-14 ) 1147 - 1150  2001.05  [Refereed]

     View Summary

    5,4'-Bis[bis(p-methoxyphenyl)amino]-2-methoxystilbene (1) was synthesized. The electrochemical and chemical oxidations of 1 produced its cationic biradical, which was studied in comparison with the biradical derived from the analogue 2 without the 2-methoxy substituent. The biradical of 1 exhibited substantial chemical stability, because the reactive 2-position of a 5,4'-biradical-substituted stilbene is effectively blocked in 1 with the methoxy substituent. However, the 2-substituent caused a torsion in the stilbenoid pi -conjugated framework to weaken its ferromagnetic coupling ability. (C) 2001 Elsevier Science Ltd. All rights reserved.

  • High oxygen permeation and persistent oxygen-carrying in a poly(vinylimidazole-co-fluoroalkyl methacrylate) cobaltporphyrin membrane

    B Shentu, H Shinohara, H Nishide

    POLYMER JOURNAL   33 ( 10 ) 807 - 811  2001  [Refereed]

     View Summary

    A membrane having both a selective oxygen-absorbing capability and a long operational lifetime was prepared by complexing picket-fence cobaltporphyrin (CoP) with poly(vinylimidazole-co-fluoropentyl methacrylate) (FIm) as a polymer-ligand. The oxygen-binding affinity of the CoP complexed in the membrane was larger than that in the solution state. Oxygen permeation was selectively facilitated with the CoP fixed in the membrane, and a high oxygen permeability (10(-7) cm(3)(STP) cm cm(-2) s(-1) cmHg(-1)) maintaining the permselectivity was observed. The lifetime of the CoP as an oxygen-carrier was prolonged by complexing with FIm even in a humid atmosphere (half-lifetime > 200 days) due to the hydrophobic property of the FIm copolymer.

  • Poly(3-phenylgalvinoxylthiophene). A new conjugated polyradical with high spin concentration

    M Miyasaka, T Yamazaki, H Nishide

    POLYMER JOURNAL   33 ( 11 ) 849 - 856  2001  [Refereed]

     View Summary

    3-{4-[(3,5-Di-tert-buty1-4-acetoxyphenyl)(3,5-di-tert-buty1-4-oxocyclohexa-2,5-diene-1-ylidene)methyl]phenyl} thiophene (2a) was synthesized and oxidatively polymerized with ferric chloride at low temperature to yield poly (3-{4-[(3,5-di-tert-buty1-4-acetoxyphenyl)(3,5-di-tert-buty1-4-oxocyclohexa-2,5-diene-1-ylidene)-methyl]phenyl} thiophene) (1a), Head-to-tail content of 1a with a molecular weight of > 10(4) reached 92%. This polymer has a quinoid chromophore, and it reversibly showed a dark blue and red brownish color ascribed to an anion and a radical form, respectively. The polyradical 1 was almost quantitatively generated from 1b (a spin concentration of 0.9 spin/galvinoxyl unit), which was persistent at room temperature. The SQUID measurement at low temperature gave a spin quantum number (S) of 1/2 for 1, which indicated a paramagnetic ground state. 1 doped with iodine showed an electrical conductivity of 10(-5) S cm(-1). The polyradical derivatives, 7 and 8, displayed S of 1/2-2/2 and 1/2, respectively, and an electrical conductivity of 10(-4)-10(-3) S cm(-1) after doping.

  • Synthesis, magnetic, and optoelectronic properties of poly(triphenylamine-alt-phenylenevinylene)s

    YJ Pu, M Soma, E Tsuchida, H Nishide

    JOURNAL OF POLYMER SCIENCE PART A-POLYMER CHEMISTRY   38 ( 22 ) 4119 - 4127  2000.11  [Refereed]

     View Summary

    Conjugated polymers alternatively involving m-phenylenevinylene or p-phenylenevinylene and a triphenylamine moiety in the main chain were synthesized via a Wittig-Horner-type polycondensation of 4-diformyl-4',4 " -dimethyl-triphenylamine or 4-diformyl-4',4 " -dimethoxy-triphenylamine with m-xylene-bis(diethylphosphonate) or p-xylene-bis(diethylphosphonate). A high glass-transition temperature (ca. 120 degreesC) and thermal stability (5% weight loss at temperatures greater than 450 degreesC) were observed for all polymers. These polymers, especially poly(methyltriphenylamine-alt-p-phenylenevinylene), fluoresced a strong green color under UV irradiation, with a quantum efficiency of 50% for their chloroform solutions. Cyclic voltammetry showed a relatively low ionization potential (5.18-5.44 eV) for the polymers. These results suggest that these polymers satisfied the requisites of polymer materials for a single-layer light-emitting diode. The aminium radical derived from the oxidation of poly(triphenylamine-alt-m-phenylenevinylene) satisfied both non-Kekule-type pi conjugation and ferromagnetic connectivity of the unpaired electrons and displayed a multiplet ground state. (C) 2000 John Wiley & Sons, Inc.

  • Regioregular polythiophene with pendant phenoxyl radicals: A new high-spin organic polymer

    M Miyasaka, T Yamazaki, E Tsuchida, H Nishide

    MACROMOLECULES   33 ( 22 ) 8211 - 8217  2000.10  [Refereed]

     View Summary

    Poly[3-(3',5'-di-tert-butyl-4'-acetoxyphenyl)thiophene] (la) was regioselectively synthesized via simple oxidative polymerization of 3-(3',5'-di-tert-butyl-4'-acetoxyphenyl)thiophene (2a) with ferric chloride. Head-to-tail content of la with a molecular weight of >10(4) reached 96% by modulating both the polymerization conditions and the purification procedure of the polymer. Visible absorption and fluorescence maxima were bathochromically shifted for both la and poly[3-(3',5'-di-tert-butyl-4'-hydroxyphenyl)thiophene] (Ib), which suggests an extended pi -conjugation, i.e., a regioregular structure. Redox of the phenolate and of the thiophene residue of Ib was observed reversibly and independently under alkaline conditions. The polyphenoxyl 1 derived from the oxidation of Ib showed an electrical conductivity of 10(-5) S cm(-1). The polyradical 1 satisfies both an alternant but non-Kekule-type pi -conjugation and ferromagnetic connectivity of the unpaired electrons of the pendant phenoxyls. 1 with a spin concentration of 0.3 spin/unit displayed a spin quantum number (S) value of 2/2 to 3/2, indicating a high-spin ground state and an intramolecular ferromagnetic spin coupling through the polythiophene backbone.

    DOI

  • Membranes of the picket fence cobalt porphyrin complexed with poly(vinylimidazole and -pyridine)s: Selective optical response to oxygen

    Y Suzuki, H Nishide, E Tsuchida

    MACROMOLECULES   33 ( 7 ) 2530 - 2534  2000.04  [Refereed]

     View Summary

    Red-colored and solvent-free membranes based on the picket fence cobaltporphyrin (CoP) complexed with two or three kinds of polymer-ligands were prepared, and their visible absorbance responses to oxygen partial pressure were studied. The four CoP complexes with copolymers of 4- and 1-vinylimidazole and 4- and 2-vinylpyridine as a polymer-ligand were characterized by different oxygen affinity: In this order of the copolymers, the oxygen affinity of CoP was decreased by a factor of 10. The membrane composed of the three CoP complexes displayed a selective and continuous response in the visible absorbance ascribed to the oxygen-adduct formation over a wide range of oxygen partial pressure, i.e., 0.01-76 cmHg at atmospheric total pressure. On the other hand, the membrane composed of the two complexes with strong and weak affinity responded in a stepwise manner to oxygen partial pressure. The CoP complexed with and fixed in the polymer-ligands could form an oxygen adduct rapidly and reversibly just as the CoP complex did in a solution. The oxygen response rate of the membrane was shortened inversely with the square root of its thickness. The operational lifetime was longer than 1 month, which was much prolonged for the CoP complexed with the fluoroalkyl methacrylate copolymers: The latter also displayed a selective and reversible oxygen response in water.

  • 3,4 '-bis[bis(t-butyl- and methoxy-phenyl)amino]stilbene bis(cation radical)s and their electrochemical and magnetic properties

    T Michinobu, E Tsuchida, H Nishide

    BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN   73 ( 4 ) 1021 - 1027  2000.04  [Refereed]

     View Summary

    3,3'-Bis[bis(p-t-butylphenyl)amino]stilbene 1a and 3,4'-bis[bis(p-methoxyphenyl)amino]stilbene 1b were synthesized. The oxidation of 1 was analyzed by electrochemical measurements, which revealed the reversible formation of the bis(cation radical) 2 via a two-electron transfer reaction. The chemical oxidation of 1 with NOBF4 also gave the bis(cation radical) 2; UV/vis and ESR spectroscopies supported aminium radical formation without any side reaction. Magnetization, magnetic susceptibility, and the ESR Delta M-s = +/-2 signal of the biradicals indicated tripler ground states with a large triplet-singlet energy gap.

  • High oxygen-binding affinity of poly(4-vinylimidazole-co-octylmethacrylate)-cobaltporphyrin complex: Effect of hydrogen-bond at the imidazole residue

    H Nishide, A Kato, E Tsuckida

    MOLECULAR CRYSTALS AND LIQUID CRYSTALS   342   249 - 254  2000  [Refereed]

     View Summary

    The oxygen-binding affinity of the cobalt-picketfence-porphyrin (CoP) ligated with imidazole was enhanced in the presence of an additive which forms a hydrogen-bond with the ligated imidazole. The CoP complex with poly(4(5)-vinylimidazole-co-octylmethacrylate) rapidly and reversibly bound oxygen and showed very high oxygen-binding affinity. The oxygen transport in the CoP-polymer membrane was efficiently facilitated.

  • Platinum porphyrin embedded in poly(1-trimethylsilyl-1-propyne) film as an optical sensor for trace analysis of oxygen

    Y Amao, K Asai, Okura, I, H Shinohara, H Nishide

    ANALYST   125 ( 11 ) 1911 - 1914  2000  [Refereed]

     View Summary

    A highly gas permeable polymer, poly(1-trimethylsilyl-1-propyne) (poly(TMSP)), was applied as an optical oxygen sensing matrix using luminescence quenching of platinum octaethylporphyrin (PtOEP) by oxygen. PtOEP was homogeneously embedded in poly(TMSP) to give a mechanically tough film with a thickness of 10 mum. The luminescence intensity of PtOEP embedded in the poly(TMSP) film drastically decreased with an increase in oxygen concentration. The oxygen sensitivity of the film (I-0/I-100 ) was very high and estimated to be 225. The Stern-Volmer plot for the poly(TMSP) film-embedded PtOEP was obeyed at lower oxygen concentrations between 0 and 10% and the Stern-Volmer constant is estimated to be 5.7%(-1). The limit of oxygen detection was less than 0.3%. The response times of PtOEP embedded in the poly(TMSP) film are 3.6 s on going from argon to oxygen and 73.2 s on going from oxygen to argon, respectively. These results indicate that PtOEP embedded in the poly(TMSP) film is a novel optical sensing material for trace analysis of oxygen.

  • Reversible oxygen-releasing from the composite of picketfence-porphyrinatocobalt and carbon in response to a 1.5 V-application

    H Nishide, Y Suzuki, E Tsuchida

    BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN   72 ( 12 ) 2791 - 2794  1999.12  [Refereed]

     View Summary

    5,10,15,20-Tetrakis(alpha-o-pivalamidophenyl)porpphyrinatcobalt(II) (CoP) complexed with N-tritylimidazole in the solid state quickly and reversibly absorbed oxygen from air (14 cm(3) O-2/g), which was ascribed to a Co/dioxygen 1/1 adduct formation. The adduct formation was an exothermic reaction, and the absorbed oxygen was released above 65 degrees C. A disk (e.g., diameter 2 cm x 2 mm) was prepared with powders of the oxygen-absorbing, but electrically insulating, CoP complex and of electrically conductive carbon. The application of 1.5 V to the disk induced a temperature elevation in the disk, which momentarily released the absorbed oxygen. The oxygen-releasing and -absorbing cycle could be repeated more than 100 times, with a 5-min switching on-off interval under ambient conditions.

  • Oxygen-carrying cobaltporphyrin complexed with electroconductive poly(3,4-azopyridylene)

    F Ito, H Nishide, E Tsuchida

    CHEMISTRY LETTERS   ( 11 ) 1149 - 1150  1999.11  [Refereed]

     View Summary

    Poly(3,4-azopyridylene) was prepared and complexed with picket-fence coaltporphyrin; the polymer complex displayed both the selective and reversible oxygen-binding and the electroconductivity of 10(-5) S cm(-1).

  • Acyclic and cyclic di- and tri(4-oxyphenyl-1,2-phenyleneethynylene)s: Their synthesis and ferromagnetic spin interaction

    H Nishide, M Takahashi, J Takashima, YJ Pu, E Tsuchida

    JOURNAL OF ORGANIC CHEMISTRY   64 ( 20 ) 7375 - 7380  1999.10  [Refereed]

     View Summary

    A new set of pi-conjugated and alternant but non-Kekule-type di- and tri(1,2-phenyleneethynylene)s pendantly substituted with phenoxyl radicals at the 4 positions (1a, 2a, and 3a) was synthesized. The synthesis of these acyclic and cyclic compounds was achieved through the head-to-tail coupling of a-bromo(or -iodo)-4-[3',5'-di-tert-butyl-4'-trimethylsiloxyl(or-hydroxy)phenyl]-1-ethynylbenzenes. The di- and triphenoxyl compounds (1a, and 2a and 3a) were triplet and quartet at the ground state, respectively, which was ascribed to a ferromagnetic coupling effect of the diphenyl ethynylene bridge for the pendant phenoxyls' spins. The cyclic pi-conjugation in 3a exhibited a stronger effect on the spin alignment.

  • High-spin polyphenoxyl based on poly(1,4-phenyleneethynylene)

    H Nishide, T Maeda, K Oyaizu, E Tsuchida

    JOURNAL OF ORGANIC CHEMISTRY   64 ( 19 ) 7129 - 7134  1999.09  [Refereed]

     View Summary

    Rodlike poly(1,4-phenyleneethynylene) fl-substituted with multiple pendant phenoxyls 1 was synthesized by polymerizing 4-bromo-2-(3,5-di-tert-butyl-4-hydroxyphenyl)ethynylbenzene 10a using the catalyst of a palladium-triphenylphosphine complex and cuprous iodide and subsequent heterogeneous oxidation. The corresponding dimer 2 was also synthesized; X-ray analysis of its precursor 4 indicated a linear phenyleneethynylene backbone and twisted dihedral angles of 50 and 77 degrees for the pendant phenol groups, ESR spectra suggested a delocalized spin distribution from the pendant phenoxyl to the backbone. The diphenoxyl 2 had a triplet (S = 2/2) ground state. The spin concentration of the polyphenoxyl 1 could not be increased beyond 0.7 spin/unit due to its low solvent solubility; 1 with a spin concentration of 0.62 had an average S of 3/2.

  • Oxygen permeability of biodegradable copolycaprolactones

    SG Wang, H Nishide, E Tsuchida

    POLYMERS FOR ADVANCED TECHNOLOGIES   10 ( 5 ) 282 - 286  1999.05  [Refereed]

     View Summary

    Polycaprolactone is one of the biodegradable polymers with good drug permeability. In the present paper, polycaprolactone and three kinds of copolycaprolactone-polycaprolactone-poly(ethylene oxide)-polycaprolactone triblock copolymer (PCE), polycaprolactone/polycaprolactone-poly(ethylene oxide)/polylactide tricomponents random block copolymer (PCEL) and polycaprolactone/poly(ethylene terephthalate) random block copolymer (PETCL)- were synthetized. The biodegradation behavior of these polymers were shown by degradation tests in vitro, ex vivo and in vivo. The oxygen permeabilities of these polymers were in the range of 10(-10) similar to 10(-9) cm(3) (STP) cm/cm(2) sec cm Hg. Copolymers PCE and PCEL displayed O-2 and N-2 permeability coefficients (PO2/PN2) ratios of about 9. The effects of composition and crystallinity of the copolymers on biodegradability and the oxygen permeability of the polymer were discussed. Copyright (C) 1999 John Wiley & Sons, Ltd.

  • Reversible stretching of a polymer-supported cobalt-chelate film in response to oxygen

    H Nishide, H Mizuma, E Tsuchida, J McBreen

    BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN   72 ( 5 ) 1123 - 1127  1999.05  [Refereed]

     View Summary

    The polymer-supported N,N'-di(salicylidene)ethylenediaminatocobalt(II) [Co(salen)] took up oxygen through 2/1 Co/dioxygen adduct formation. The composite film of the polymer-supported [Co(salen)] and polymer layers reversibly bent under an oxygen and nitrogen atmosphere. The stretching was caused by a structural change in the [Co(salen)] crystal before and after the oxygen-binding, which was analyzed based on the near-IR spectral and density change as well as EXAFS.

  • High-spin oxyphenylbenzo-annelated dehydro[12]annulene

    YJ Pu, M Takahashi, E Tsuchida, H Nishide

    CHEMISTRY LETTERS   ( 2 ) 161 - 162  1999.02  [Refereed]

     View Summary

    A ground state quartet molecule, 2, 8, 14-trisoxyphenyltri-benzotrisdehydro[12]annulene, was synthesized; the dehydro-annulene acted as an effective ferromagnetic coupler for the pendant spins.

  • Polyphenoxyl radical photochemically generated from the oxalate derivative of poly(1,2-phenylenevinylene)

    M Takahashi, Y Nasu, H Nishide, E Tsuchida

    POLYMER JOURNAL   31 ( 2 ) 203 - 205  1999  [Refereed]

  • Synthesis and ferromagnetic spin alignment in poly(4-oxyphenyl-1,2-phenyleneethynylene)s

    H Nishide, M Takahashi, J Takashima, E Tsuchida

    POLYMER JOURNAL   31 ( 11 ) 1171 - 1174  1999  [Refereed]

     View Summary

    Some non-Kekule-type organic molecules exhibit a high-spin state based on an intramolecular spin-exchange interaction. These high-spin molecules can be extended to the corresponding polyradicals with spins that are ferromagnetically aligned. Poly(4-oxyphenyl-1,2-phenyleneethynylene) was synthesized, and the effect of the head-to-tail connectivity on the ferromagnetic interaction is described.

  • Effect of delocalized and ferromagnetic electrons on optical third-order nonlinearity of a マ�-conjugated polymer: poly(4-oxyphenyl-1,2-phenylenevinylene)

    Takahashi, Masahiro, Yamada, Shinji, Matsuda, Hiro, Nakanishi, Hachiro, Tsuchida, Eishun, Nishide, Hiroyuki

    Molecular Crystals and Liquid Crystals Science and Technology Section B: Nonlinear Optics   22 ( 39450 ) 345 - 348  1999  [Refereed]

  • Nonlinear Optical Property of Poly(Phenylenevinylene) Bearing マ�-Conjugated Radicals

    Takahashi, M, Yamada, S, Matsuda, H, Tsuchida, E, Nishide, H

    Molecular Crystals and Liquid Crystals Science and Technology Section A: Molecular Crystals and Liquid Crystals   334   31 - 39  1999  [Refereed]

  • Phenoxyl Radicals Ferromagnetically Attached to a Cyclic マ�-Conjugation: 2,8,14-Trisoxyphenyltribenzotrisdehydro[12]Annulene

    Pu, Y.-J, Takahashi, M, Tsuchida, E, Nishide, H

    Molecular Crystals and Liquid Crystals Science and Technology Section A: Molecular Crystals and Liquid Crystals   334   1 - 10  1999  [Refereed]

  • Poly(4-diphenylaminium-l,2-phenylenevinylene): A high-spin and durable polyradical

    Takahashi, M, Nakazawa, T, Tsuchida, E, Nishide, H

    Macromolecules   32 ( 19 ) 6383 - 6385  1999  [Refereed]

  • Polymerization of (p-vinylphenyl)hydrogalvinoxyl and formation of a stable polyradical derivative

    T Kaneko, H Tatsumi, T Aoki, E Oikawa, H Yoshiki, N Yoshioka, E Tsuchida, H Nishide

    JOURNAL OF POLYMER SCIENCE PART A-POLYMER CHEMISTRY   37 ( 2 ) 189 - 198  1999.01  [Refereed]

     View Summary

    4-[(3,5-Di-tert-butyl-4-hydroxyphenyl)(3 2,5-di-tert-butyl-4-oxo-cyclohexa-2,5-dienylidene)methyl]styrene (abbreviated as (p-vinylphenyl)hydrogalvinoxyl) was polymerized using AIBN as an initiator to give a bright yellow polymer with <(M)over bar (w)> = 3.2 x 10(4). The polymer was oxidized to give the corresponding polyradical derivative, whose spin concentration could be increased up to about 70 mol % depending on oxidative conditions. ESR signal line-width in the solid state was greatly increased below 200 K for the polyradical with a high spin concentration (> 50 mol %). The magnetization and magnetic susceptibility indicated weak antiferromagnetic interaction among the radical sites. (C) 1999 John Wiley & Sons, Inc.

  • 5,10,15,20-Tetrakis(ホア,ホア,ホア,ホア-o-pivalamidophenyl) porphinatoiron(II) bearing a covalently linked axial imidazole via m-aminobenzoic acid. Synthesis and influence of imidazole basicity on O2-binding affinity

    Komatsu, T, Furubayashi, Y, Nishide, H, Tsuchida, E

    Inorganica Chimica Acta   295 ( 2 ) 234 - 238  1999  [Refereed]

  • Robust triplet molecule: Cationic diradical of 3,4窶イ-bis(diphenylamino)stilbene

    Michinobu, T, Takahashi, M, Tsuchida, E, Nishide, H

    Chemistry of Materials   11 ( 8 ) 1969 - 1971  1999  [Refereed]

  • Highly selective oxygen permeation through a poly(vinylidene dichloride) cobalt porphyrin membrane: Hopping transport of oxygen via the fixed cobalt porphyrin carrier

    H Nishide, Y Tsukahara, E Tsuchida

    JOURNAL OF PHYSICAL CHEMISTRY B   102 ( 44 ) 8766 - 8770  1998.10  [Refereed]

     View Summary

    A combination membrane having both gas barrier properties and selective oxygen-absorbing and -carrying capability was prepared by complexing poly(vinylidene dichloride-co-vinylimidazole) and meso-tetrakis(alpha,alpha,alpha,alpha-o-pivalamidophenyl)porphyrin (CoP). The vinylidene dichloride copolymer was selected because of its low physical gas permeability and its dense and tough thin-membrane formability even after the CoP complexation. Oxygen permeation was selectively facilitated with the CoP carrier fixed in the membrane, and high oxygen permselectivity (facilitation factor > 25, oxygen/nitrogen permselectivity > 100, permeability 10(-10) cm(3) (STP) cm cm(-2) s(-1) cmHg(-1)) was observed, e.g., for the membrane containing > 20 wt % CoP at an upstream oxygen partial pressure of 0.5 cmHg. The facilitated oxygen transport was properly analyzed by a dual-mode model to give permeation parameters of the membrane such as the postulated diffusion coefficient of oxygen hopping via the fixed CoP carrier (D-C). D-C was inversely proportional to the average distance between the CoP carrier sites.

  • High-spin polyphenoxyls attached to star-shaped poly(phenyleneninylene)s

    H Nishide, M Miyasaka, E Tsuchida

    JOURNAL OF ORGANIC CHEMISTRY   63 ( 21 ) 7399 - 7407  1998.10  [Refereed]

     View Summary

    Star-shaped poly(1,2-phenylenevinylene)s 4-substituted with multiple pendant phenoxyls (2 and 3) were synthesized by polymerizing 2-bromo-4-(acetoxyphenyl)styrene in the presence of 1,3,5-triiodobenzene or 1,3,5-tris(3',5'-diiodophenyl)benzene as the core via a simple one-pot Heck reaction and subsequent hydrolysis, phenolate formation, and heterogeneous oxidation. ESR spectra indicated a delocalized spin distribution into the core parts of the star-shaped molecules. The polyradicals, 2 and 3, were in a high-spin state at low temperature, and the ferromagnetic behavior was enhanced for the polyradical with a higher molecular weight. Although an average S of 3 remained at 3/2 to 4/2, the polyradical 2 even with a spin concentration of 0.8 spin/unit revealed an average S of 7/2 to 8/2. The 1,3,5-benzene core acted as an effective magnetic coupler to align the spins of the pendant phenoxyls through the star-shaped pi-conjugated backbone.

  • Polymeric cobalt-Schiff-base and -porphyrin complexes as a dioxygen device

    H Nishide, Y Tsukahara, Y Suzuki, E Tsuchida

    MACROMOLECULAR SYMPOSIA   131   95 - 101  1998.05  [Refereed]

     View Summary

    New functions of polymeric cobalt complexes were examined using their oxygen-binding reactions in the solid state. An oxygen-releasing device was prepared by compositing the oxygen-binding but electrically insulating cobalt-Schiff-base or -porphyrin complex with a conductive carbon powder. The device quickly released the absorbed oxygen in response to an applied voltage. A polymer film containing the cobalt-Schiff-base complex reversibly stretched in response to the atmospheric oxygen concentration. The driving force of the stretching of the film was attributed to the crystal structure change of the complex before and after the oxygen-binding.

  • Subcutaneous microvascular responses to hemodilution with a red cell substitute consisting of polyethyleneglycol-modified vesicles encapsulating hemoglobin

    H Sakai, AG Tsai, H Kerger, SI Park, S Takeoka, H Nishide, E Tsuchida, M Intaglietta

    JOURNAL OF BIOMEDICAL MATERIALS RESEARCH   40 ( 1 ) 66 - 78  1998.04  [Refereed]

     View Summary

    Phospholipid vesicles encapsulating purified hemoglobin [Hb vesicles (HbV); diameter 259 +/- 82 mm; oxygen affinity 31 mm Hg; [Hb] 5 and 10 g/dL] were developed to provide oxygen-carrying capacity to plasma expanders. Their function as a blood replacement was tested in the subcutaneous microvasculature of awake hamsters during severe hemodilution in which 80% of the red blood cell mass was substituted with suspensions of the vesicles in 5% human serum albumin (HSA) solution. Vesicles were tested with membranes that were unmodified (HbV/HSA) or conjugated with polyethyleneglycol (PEG) on the vesicular surface (PEG-HbV/HSA). The viscosity of 10 g/dL HbV/HSA was 8 cP at 358 s(-1) owing to the intervesicular aggregation, while that of 10 g/dL PEG-HbV/HSA was 3.5 cP, since PEG chains inhibit aggregation. Both materials yielded normal mean arterial pressure, heart rate, and blood gas parameters at all levels of exchange, which could not be achieved with HSA alone. Subcutaneous microvascular studies showed that PEG-HbV/HSA significantly improved microhemodynamic conditions (flow rate, functional capillary density, vessel diameter, and oxygen tension) relative to unmodified HbV/HSA. Even though the enhancement of PEG modification did not achieve the functional characteristics of the blood-perfused microcirculation, PEG reduced vesicular aggregation and viscosity, improving microvascular perfusion relative to the unmodified type. These results highlight the significance of microvascular analysis in the design of red cell substitutes and the necessity of surface modification of HbV to prevent aggregation. (C) 1998 John Wiley & Sons, Inc.

  • Human serum albumin-bound synthetic hemes as an oxygen carrier: Determination of equilibrium constants for heme binding to host albumin

    T Komatsu, K Hamamatsu, S Takeoka, H Nishide, E Tsuchida

    ARTIFICIAL CELLS BLOOD SUBSTITUTES AND IMMOBILIZATION BIOTECHNOLOGY   26 ( 5-6 ) 519 - 527  1998  [Refereed]

     View Summary

    Human serum albumin (HSA) incorporating synthetic tetraphenylporphinatoiron(II) derivatives (FeP1 or FeP2) can bind and release oxygen reversibly under physiological conditions (in aqueous media, pH 7.4, 37 degrees C). The maximal binding ratio of FeP1/HSA was estimated to be eight, and the stepwise equilibrium constants for FeP1 binding to HSA (K-1-K-8) ranged from 1.2x10(6) to 1.3x10(4) M-1. The major binding sites of FeP1 are presumably identical to those of hemin, bilirubin and long-chain fatty acids. The O-2-binding ability of the HSA-FeP can be regulated by changing the molecular structure of the incorporated hemes. The half-lifetime of the O-2-coordinated FeP2 in HSA was significantly longer than that of HSA-FeP1.

  • Oxygen releasing from cellular hemoglobin

    N Kawai, H Ohkawa, H Maejima, S Takeoka, H Nishide, E Tsuchida

    ARTIFICIAL CELLS BLOOD SUBSTITUTES AND IMMOBILIZATION BIOTECHNOLOGY   26 ( 5-6 ) 507 - 517  1998  [Refereed]

     View Summary

    The oxygen-releasing behavior of hemoglobin vesicles (HbV) was measured in order to study the difference in oxygen dynamics inside and outside the cellular Hb using a conventional stopped now method and a newly developed stopped flow flash photolysis method. The partial pressure of oxygen in the solution outside the HbV was monitored with the lifetime of the triplet state of meso-tetraphenylporphinatozinc(II) bound to human serum albumin excited by the laser flash. The change in the partial pressure of oxygen outside the HbV showed a biphasic profile and was slower than that inside the HbV. The first phase shows the oxygen-releasing process from Hb near the phospholipid bilayer membrane, and the second phase is considered the process in which oxygen diffuses to the bulk aqueous region and reaches the equilibrium value.

  • Effects of the pH-controlled hemoglobin vesicles by CO2 gas

    S Park, T Kose, M Hamasaki, S Takeoka, H Nishide, E Tsuchida

    ARTIFICIAL CELLS BLOOD SUBSTITUTES AND IMMOBILIZATION BIOTECHNOLOGY   26 ( 5-6 ) 497 - 506  1998  [Refereed]

     View Summary

    The hemoglobin vesicle (HbV) is a red cell substitute encapsulating purified concentrated Hb in a phospholipid vesicle. In order to improve the oxygen carrying capability of HbV, the pH value of the Hb solution should be adjusted to 7.0 in the HbV preparation, and then the pH value should be adjusted to 7.4 where HbV functions as an oxygen carrier, because the maximum value of [Hb]/[Lipid] was obtained in which the pH of the Hb solution was 7.0, and the metHb formation rate was suppressed in the pH 7.4. Generally, the pH control of the inner aqueous phase of HbV is difficult by changing the pH in the outer phase. We could control the pH of the Hb solution from 7.4 to 7.0 by dissolving CO2 into the Hb solution, and after the preparation of HbV, the pH of HbV is changed to 7.4 by reducing the pressure. The resulting pH-controlled HbV by CO2 gas showed a high [Hb]/[Lipid] value of 1.7 with a low rate of metHb formation.

  • Average octet radical polymer: A stable polyphenoxyl with star-shaped マ� conjugation

    Nishide, H, Miyasaka, M, Tsuchida, E

    Angewandte Chemie - International Edition   37 ( 17 ) 2400 - 2402  1998  [Refereed]

  • An oxygen-releasing device: reversible oxygen release from a cobalt chelate carbon composite in response to an applied voltage

    H Nishide, E Soda, H Mizuma, E Tsuchida

    JOURNAL OF MATERIALS CHEMISTRY   7 ( 10 ) 2151 - 2153  1997.10  [Refereed]

     View Summary

    A disk (e.g. diameter 2 cm x 2 mm) was made of [N,N'-bis(salicylidene)ethylenediamine] cobalt [Co(salen)] and carbon powder. The composite disk selectively absorbed oxygen from air, e.g. 22 cm(3) oxygen per gram of composite at room temperature, which is almost stoichiometrically ascribed to 2: 1 cobalt-dioxygen adduct formation. The adduct formation was an exothermic reaction, and the absorbed oxygen was released above 80 degrees C. The application of 6 V to the disk sandwiched between platinum meshes induced a temperature elevation in the disk, which quickly released the absorbed oxygen. Under ambient conditions, the oxygen-releasing and -absorbing processes could be established within a few min and a 30 min interval, respectively, for the composite disk containing the 3-ethoxy derivative of Co(salen), while the oxygen absorption took several hours for the Co(salen) disk.

  • Highly selective oxygen transport through a cobalt porphyrin liquid membrane

    XS Chen, H Nishide, K Oyaizu, E Tsuchida

    JOURNAL OF PHYSICAL CHEMISTRY B   101 ( 29 ) 5725 - 5729  1997.07  [Refereed]

     View Summary

    The facilitated transport of oxygen in a liquid membrane containing [meso-alpha,alpha,alpha,alpha-tetrakis(o-pivalamidophenyl)porphyrinatocobalt(II)]-laurylimidazole (CoP) as an oxygen carrier leads to high permeability and permselectivity of oxygen against nitrogen. The oxygen permeation was properly analyzed by a dual-mode model and using the oxygen-binding constants spectroscopically determined, to give permeation parameters of the membrane such as the diffusion coefficient (D-CoP) of the CoP mobile carrier and the physical diffusion coefficient of oxygen. D-CoP was in accordance with that electrochemically determined. The facilitated permeation was represented by the product of the Cop concentration and D-CoP in the membrane solution. D-CoP decreased with solution viscosity and increased with the measured temperature. High oxygen permeability (10(-7) cm(3)(STP) cm cm(-2) s(-1) cmHg(-1)) was observed, e.g. for the membrane of the 31 wt % CoP methylanisole solution at 10 degrees C, where the facilitation factor and the oxygen/nitrogen permselectivity were over 20 and 40, respectively.

  • Properties of and oxygen binding by albumin-tetraphenylporphyrinatoiron(II) derivative complexes

    E Tsuchida, K Ando, H Maejima, N Kawai, T Komatsu, S Takeoka, H Nishide

    BIOCONJUGATE CHEMISTRY   8 ( 4 ) 534 - 538  1997.07  [Refereed]

     View Summary

    A hydrophobic tetraphenylporphyrinatoiron(II) derivative bearing a covalently bound axial imidazole [Fe(II)P] was efficiently and noncovalently bound into human serum albumin (HSA) up to an average of eight Fe(II)P molecules per HSA molecule. The aqueous solutions of the HSA-Fe(II)P complex provided a reversible and relatively stable oxygen adduct under physiological conditions (pH 7.4 and 37 degrees C). The half-life of the oxygen adduct (tau(1/2)) was 1 h at 37 degrees C in an air atmosphere. With Fe(II)TpivPP (the so-called ''picket-fence heme'') having no axial base, an oxygenated HSA-Fe(II)TpivPP complex was obtained using a 20-fold molar excess of 1,2-dimethylimidazole, but the tau(1/2) was very short (ca. 10 min at 37 degrees C). The oxygen affinity [P-1/2(O-2)] and oxygen transporting efficiency (OTE) of HSA-Fe(II)P at 37 degrees C were 30 Torr and 22%, respectively. Furthermore, the oxygen-binding and dissociation rate constants (k(on), and K-off) are extremely high in comparison with those of hemoglobin. The HSA molecule binding eight Fe(II)P molecules can transport about 3.4 mL/dL of oxygen under physiological conditions, corresponding to about 60 % of the oxygen transporting amount of human blood.

  • Methemoglobin formation in hemoglobin vesicles and reduction by encapsulated thiols

    S Takeoka, H Sakai, T Kose, Y Mano, Y Seino, H Nishide, E Tsuchida

    BIOCONJUGATE CHEMISTRY   8 ( 4 ) 539 - 544  1997.07  [Refereed]

     View Summary

    The hemoglobin vesicle (HbV) is a red cell substitute encapsulating purified concentrated Hb in a phospholipid vesicle. In order to suppress metHb formation or autoxidation, for the long-term maintenance of the oxygen transporting capability, a series of thiols (cysteine, Cys; glutathione, GSH; homocysteine, Hey; and acetylcysteine, Acy) were studied as reductants of metHb. Hey and GSH showed a good suppressive effect on metHb formation, while Cys adversely accelerates the metHb formation at a rate twice that of the Ho solution without any reductants and Acy showed no change. The significant suppression by the coaddition of superoxide dismutase (SOD) and catalase to Cys indicated that Cys was easily oxidized by oxygen and simultaneously generates a large amount of active oxygens. The effective suppression of metHb formation by SOD and catalase was not observed for HbV containing no reductants, indicating that the generation of active oxygens from Hb itself is not significant. The coencapsulation of Hey with Hb resulted in a low rate of metHb formation in HbV (initial rate, 1%h) in vitro at an oxygen partial pressure (P-o2) of 142 Torr. The rate increased with decreasing P-o2, showed a maximum (2.2 %h) around P-o2 = 23 Torr, and then decreased to 0%/h at 0 Torr. From these results, it is suggested that the fast metHb formation rate in the blood circulation of Wistar rats injected with 20 vol % of the HbV solution would be mainly caused by the exposure of HbV to the low P-o2.

  • Evaluation of the capabilities of a hemoglobin vesicle as an artificial oxygen carrier in a rat exchange transfusion model

    Y Izumi, H Sakai, T Kose, K Hamada, S Takeoka, A Yoshizu, H Horinouchi, R Kato, H Nishide, E Tsuchida, K Kobayashi

    ASAIO JOURNAL   43 ( 4 ) 289 - 297  1997.07  [Refereed]

     View Summary

    Encapsulation of hemoglobin within a liposome is one of the strategies in the development of artificial oxygen carriers. It maintains the oxygen transporting properties of hemoglobin and, at the same time, eliminates the side effects of cell free hemoglobin. Hemoglobin vesicles (HbV) are a type of liposome encapsulated hemoglobin. They have a particle size of approximately 250 nm, a hemoglobin concentration of 10 g/dl, and the oxygen affinity, P50, is regulated to 32 Torr. In this study the authors examined the oxygen transporting capability of HBV in vivo, by performing exchange transfusions in rats. Exchange transfusion (90% of the estimated circulatory volume) with HbV suspended in 5% albumin (containing 160 mEq/L, sodium and 107 mEq/L, chloride) was carried out in mate Wistar rats. Mean arterial pressure and heart rate were monitored through the arterial catheter. Arterial blood samples for gas analyses were also obtained from the arterial catheter. Abdominal aortic blood flow was measured by an ultrasonic pulsed Doppler flowmeter as an indicator of cardiac output. The oxygen tension of blood withdrawn from the right atrium was measured as an indicator of mixed venous oxygen tension. These values were employed to calculate oxygen delivery and consumption. Renal cortical and skeletal muscle tissue oxygen tensions were monitored as indicators of tissue perfusion. Five percent albumin and washed rat red blood cells suspended in 5% albumin containing 10 g/dl of hemoglobin, were employed as controls. At the completion of a 90% exchange transfusion, renal cortical and skeletal muscle tissue oxygen tensions, along with oxygen delivery and consumption, were sustained almost equally well with the HbV suspension compared to the washed rat red blood cell suspension, but declined significantly with the albumin suspension. The results indicate that the oxygen transporting capability of HbV was almost equivalent to that of rat red blood cells.

  • O-2 binding and dissociation and ligand exchange reaction of O-2 with CO in polymer composite films of hemoglobin

    SI Park, H Sakai, S Takeoka, H Nishide, E Tsuchida

    POLYMERS FOR ADVANCED TECHNOLOGIES   8 ( 6 ) 366 - 370  1997.06  [Refereed]

     View Summary

    A polymer composite film of hemoglobin (Hb-polymer film) teas prepared by the casting of an Hb-polymer mixed solution (weight ratio of Hb to polymer is 1 to 1). The percentages of O-2 and CO saturation of the Hb-dextran film were 46% and 70%, respectively. In the Hb solution, 100% saturation was observed for both ligands, and a humidified Hb-dextran film also showed 100% saturation. Water molecules would provide flexibility to the matrix polymer and promote a structural change in the Hb from a tense state (T) to a relaxed state (R). Thus the ligand binding to the Hb in the polymer films teas strongly affected by the degree of interaction of Hb with the matrix polymers and the physical properties of the polymers. Inositol hexaphosphate (IHP) worked as an allosteric effector even in the solid polymer film and lowered the oxygen affinity of Hb. The O-2 transport through an Hb-polyethyleneimine (PEI) film with IHP showed the facilitated O-2 transport in comparison with the film without IHP because of the high dissociation rate of O-2 from Hb with IHP. (C) 1997 by John Wiley & Sons, Ltd.

  • Reduction of methemoglobin via electron transfer across the bilayer membrane of hb vesicles

    S Takeoka, T Ohgushi, H Nishide, E Tsuchida

    BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN   70 ( 5 ) 1171 - 1178  1997.05  [Refereed]

     View Summary

    The hemoglobin vesicle (HbV) has a cellular structure which encapsulates concentrated Hb in the inner aqueous phase of a phospholipid bilayer vesicle. Hb is gradually autoxidized to methemoglobin (metHb), which can not bind oxygen during oxygen transport under physiological conditions. In order to reduce metHb in HbV, we evaluated the reduction of metHb by electron transfer across the bilayer membrane of HbV from a reductant added to the outer aqueous phase. Water-soluble methylene blue (MB) and hydrophobic ubiquinone 10 (UQ) were selected as electron mediators. Under a nitrogen atmosphere, the addition of the reduced form nicotinamide-adenine dinucleotide (NADH) to the outer aqueous phase of UQ-incorporated HbV showed only a slow reduction rate for metHb. On the other hand, when MB and NADH were added under a nitrogen atmosphere to HbV containing 40% metHb, a rapid decrease in the metHb percentage was observed. The entire reaction was controlled by a reaction with NADH and MB in the outer aqueous phase. Under aerobic conditions, the decrease in the efficiency of the metHb reduction and rapid oxidation after reaching the minimal metHb percentage were observed. This was confirmed to be due to the influence of hydrogen peroxide; the decrease was prevented by the co-encapsulation of catalase.

  • Selective optical response to oxygen of membranes based on immobilized cobalt(II) porphyrins

    S Roosli, E Pretsch, WE Morf, E Tsuchida, H Nishide

    ANALYTICA CHIMICA ACTA   338 ( 1-2 ) 119 - 125  1997.02  [Refereed]

     View Summary

    New types of oxygen-sensitive membranes based on immobilized (meso-alpha,alpha,alpha,alpha-tetrakis(o-pivalamidopheyl) porphina-to)cobalt(II)(CoP) were prepared, and their optical response behavior was studied. The complex Cop was immobilized on poly(octylmethacrylate-co-1-vinylimidazole)(OIm) and on poly(2,2,3,3,4,4,5,5-octafluoropentylmethacrylate-co-1-vinylimidazole) (OFIm), respectively. The selective recognition mechanism for an optical response to oxygen is based on the reversible formation of oxo-adducts at the cobalt(II) centers. The useful response range was found to cover 1-1000 hPa (mbar) of oxygen partial pressure, i.e., oxygen contents of 0.1-100% at atmospheric pressure. Optimum performance was achieved with the fluorinated CoP-OFLm membrane of 20 mu m thickness, for which the 90% response time was 5-15s, and the operational lifetime was longer than 1 month.

  • Poly(1,2-phenylenevinylene)s bearing nitronyl nitroxide and galvinoxyl at the 4-position: マ�-Conjugated and non-Kekulテゥ-type polyradicals with a triplet ground state

    Nishide, H, Hozumi, Y, Nii, T, Tsuchida, E

    Macromolecules   30 ( 14 ) 3986 - 3991  1997  [Refereed]

  • Structural characterization of ''tailed picket-fence porphyrins'' by high-energy fast atom bombardment collision-induced dissociation mass spectrometry mass spectrometry

    T Shibue, H Kambe, H Nishide, S Akashi, N Dohmae, Y Ohashi

    EUROPEAN MASS SPECTROMETRY   3 ( 4 ) 291 - 299  1997  [Refereed]

     View Summary

    The applicability of high-energy fast atom bombardment (FAB) collision-induced dissociation mass spectrometry/mass spectrometry (CID-MS/MS) to the structural characterization of side-chains of porphyrin derivatives with a ''tailed picketfence'' structure was examined, These porphyrins showed a molecular ion [M](+.) as well as a protonated molecule [M + H](+) and another at [M + 2](+) in the positive ion mode, Doubly-charged ions were observed when the ''tail'' has an imidazole ring,
    The linked-scan spectrometry indicated that the ''tail'' of the porphyrin is eliminated first as a neutral species from the pyrrole-2-position as a beta-type cleavage, after which each of the four pivaloyl ''picket-fences'' are cleaved off in series from the remainder of the molecule-related ions, The spectrum also clearly showed charge-remote product ions in the low mass region, in addition to charge-mediated product ions representing the precise side chain structure of the ''tailed picket-fence'' porphyrin, FAB CID-MS/MS spectra of [M](+.), [M + 1](+) and [M + 2](+), using the EBEB-type four-sector tandem mass spectrometer, show similar fragmentation patterns to each other with 1 u difference in parallel, The CID-MS/MS of [M + 1](+) and [M + 2]+ showed higher product ion intensities than the corresponding product ion intensities of [M](+.), CID-MS/MS, using an EBEB-type four-sector tandem mass spectrometer, showed charge-remote product ions much more clearly than those observed in B/E-constant linked-scan spectra.

  • Optical nonlinearity of an open-shell and degenerate マ�-conjugated polymer: Poly(4-oxyphenyl-1,2-phenylenevinylene) radical

    Takahashi, M, Yamada, S, Matsuda, H, Nakanishi, H, Tsuchida, E, Nishide, H

    Chemical Communications   ( 19 ) 1853 - 1854  1997  [Refereed]

  • Imidazolyl-tailed tetrakis(pivalamidophenyl)porphyrinatocobalt(II): An efficient oxygen adsorbent molecule

    H Nishide, A Suzuki, E Tsuchida

    BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN   70 ( 9 ) 2317 - 2321  1997  [Refereed]

     View Summary

    A meso-tetrakis(alpha,alpha,alpha,alpha-o-pivalamidophenyl)porphyrinatocobalt(II) derivative bearing covalently-bound imidazole (Scheme 1, CoPim) was synthesized. Oxygen-binding to CoPim was rapid and reversible. The CoPim in the solid state chemically adsorbed oxygen (20 ml O-2/g CoPim), which was ca. 40-times greater than the physical adsorption amount. The oxygen-binding lifetime of CoPim was longer than that for the corresponding porphyrinatocobalt(II) with an externally added imidazole. The efficiency of CoPim as an oxygen carrier was demonstrated by oxygen-enrichment from air using a pressure-swing adsorption experiment.

  • Surface modification of hemoglobin vesicles with poly(ethylene glycol) and effects on aggregation, viscosity, and blood flow during 90% exchange transfusion in anesthetized rats

    H Sakai, S Takeoka, SI Park, T Kose, H Nishide, Y Izumi, A Yoshizu, K Kobayashi, E Tsuchida

    BIOCONJUGATE CHEMISTRY   8 ( 1 ) 23 - 30  1997.01  [Refereed]

     View Summary

    Poly(ethylene glycol) (PEG(5000))-conjugated phosphatidylethanolamine was introduced onto the surface of hemoglobin vesicles (HbV); phospholipid vesicles encapsulating concentrated Hb (d = 0.257 +/- 0.087 mu m; P-50 = 32 Torr). The obtained PEG-modified HbV (HbV-PEG) was studied for use as a red cell substitute from the viewpoint of rheology, surface properties, and hemodynamics. The viscosity of the unmodified HbV suspended in saline ([Hb] = 10 g/dL) was 2.6 cP (shear rate = 358 s(-1), 37 degrees C), less than that of human blood (4 cP). However, when suspended in a 5 g/dL albumin solution (HbV/albumin), it increased to 8 cP due to the molecular interaction between albumin and vesicles, and the viscosity increased with decreasing shear rate, e.g., 37 cP at 0.58 s(-1). As for the HbV-PEG/albumin, on the other hand, the viscosity was 3.5 cP at 358 s(-1) and was comparable with that of human blood. Optical microscopy showed formless flocculated aggregates of the unmodified HbV, while no aggregates were confirmed for the HbV-PEG. The steric hindrance of PEG chains seemed to be effective in preventing intervesicular access and the resulting aggregation To estimate the flow profiles in the capillaries, the suspensions were allowed to penetrate through isopore membrane filters (pore size = 0.4-8 mu m, cf. capillary diameter = 4-10 mu m). The penetration rate of the HbV-PEG/albumin was higher than that of the unmodified HbV/albumin due to the suppression of aggregation, whereas both of them were significantly higher than that of human blood due to the smaller size of vesicles than RBC. Ninety percent exchange transfusion was performed with the HbV-PEG/albumin or HbV/albumin in anesthetized Wistar rats (n = 6). The blood flow in the abdominal aorta increased 1.5 times, and the total peripheral resistance decreased in the HbV-PEG/albumin-administered group in comparison with the HbV/albumin group. As for the blood gas parameters, the base excess and pH remained at higher levels in the HbV-PEG/albumin group, and the O-2 tension in mixed venous blood for the HbV-PEG/albumin group tended to be maintained at a higher level than that for the HbV/albumin group. Thus, the PEG modification of HbV reduced the viscosity by the suppression of aggregation and resulted in prompt blood circulation in vivo.

  • Construction of artificial methemoglobin reduction systems in Hb vesicles

    S Takeoka, T Ohgushi, H Sakai, T Kose, H Nishide, E Tsuchida

    ARTIFICIAL CELLS BLOOD SUBSTITUTES AND IMMOBILIZATION BIOTECHNOLOGY   25 ( 1-2 ) 31 - 41  1997  [Refereed]

     View Summary

    The hemoglobin vesicle (HbV) is a red cell substitute encapsulating purified concentrated Hb in a phospholipid vesicle. In order to suppress metHb formation for the long term maintenance of oxygen transporting capability in vivo, thiols (cysteine, Cys; homocysteine, Hey) were studied as reductants of metHb. Hey showed a suppressive effect on metHb formation, while Cys adversely accelerates metHb formation at the rate of twice the Hb solution without any reductants. The suppression of Cys-induced metHb formation by the addition of superoxide dismutase (SOD) and catalase indicated that Cys was easily oxidized by oxygen and simultaneously generated a large amount of active oxygens. The rate of metHb formation was influenced by PO2 and pH. Furthermore, the reducing systems (methylene blue (MB), NADH or ascorbic acid) were added to the outer aqueous phase of HbV, and the artificial reduction systems constructed through the bilayer membrane were evaluated.

  • Facilitated oxygen transport with modified and encapsulated hemoglobins across non-flowing solution membrane

    H Nishide, XS Chen, E Tsuchida

    ARTIFICIAL CELLS BLOOD SUBSTITUTES AND IMMOBILIZATION BIOTECHNOLOGY   25 ( 4 ) 335 - 346  1997  [Refereed]

     View Summary

    The oxygen-transporting capability of modified and encapsulated hemoglobins and red cells is discussed from a physico-chemical standpoint in order to design oxygen-delivering fluids. The oxygen diffusion coefficient toward oxygen-deficient sites was estimated by measuring the oxygen flux across thin solution membranes of hemoglobin, polymerized hemoglobin, liposome-encapsulated hemoglobin, and red cells. Oxygen flux was enhanced several times over that of nitrogen for the hemoglobin and red cell solution with cn. [Hb] = 10 and 15 g/dl, respectively. The enhancement in the oxygen diffusion is ascribed to the facilitated transport of oxygen via the hemoglobins. This was in contrast to the simple and physical oxygen-diffusivity in response to its concentration gradient, in the absence of hemoglobins. The flux of the oxygen transport was in the order of hemoglobin > red cells > polymerized hemoglobin > encapsulated hemoglobin, which was ascribed to the facilitated transport efficiencies of oxygen with hemoglobins in a non-flowing or stationary solution.

  • The oxygen carrying capability of hemoglobin vesicles evaluated in rat exchange transfusion models

    K Kobayashi, Y Izumi, A Yoshizu, H Horinouchi, SI Park, H Sakai, S Takeoka, H Nishide, E Tsuchida

    ARTIFICIAL CELLS BLOOD SUBSTITUTES AND IMMOBILIZATION BIOTECHNOLOGY   25 ( 4 ) 357 - 366  1997  [Refereed]

     View Summary

    To evaluate the oxygen transporting capability of Hemoglobin vesicles (HbV) the physiological responses to 40% and 90% exchange transfusions with HbV in anesthetized rat were observed. Hb concentration of HbV dispersions is 10g/dL. HbV dispersed in phosphate buffered saline and HbV dispersed in 5% albumin solution were used as samples for 40% and 90% exchange transfusions, respectively. HbV surface-modified with polyoxyethylene (HbV-Poe) was also used in the 90% exchange transfusion. As controls, phosphate buffered saline, 5% albumin solution, and HbV containing methemoglobin and therefore deprived of oxygen transporting capabilities (metHbV) were administered as non-oxygen carrying fluids and washed rat red blood cells (ratRBC) as an oxygen carrying fluid. Measurements included mean arterial pressure, arterial blood gas analyses, aortic blood flow and renal cortical tissue oxygen tension. At the completion of the exchange transfusion renal cortical tissue oxygen tensions along with oxygen delivery and consumption were sustained almost equally well with the HbV dispersion compared to the washed rat red blood cell dispersion, but declined significantly in the phosphate buffered saline and albumin solutions. These results indicated that the oxygen transporting capability of HbV was almost equivalent to that of rat red blood cells. in the HbV-Poe group, aortic blood flow was sustained higher in comparison to the HbV group. As for the blood gas parameters, pH and venous oxygen tensions in the HbV-Poe group tended to be higher than those in the HbV group.

  • Physiologic responses to exchange transfusion with hemoglobin vesicles as an artificial oxygen carrier in anesthetized rats: Changes in mean arterial pressure and renal cortical tissue oxygen tension

    Y Izumi, H Sakai, K Hamada, S Takeoka, T Yamahata, R Kato, H Nishide, E Tsuchida, K Kobayashi

    CRITICAL CARE MEDICINE   24 ( 11 ) 1869 - 1873  1996.11  [Refereed]

     View Summary

    Objectives: To evaluate the oxygen transporting capabilities of hemoglobin vesicles by studying the physiologic responses to exchange transfusion with hemoglobin vesicles in anesthetized rats. Exchange transfusions with phosphate buffered saline, hemoglobin vesicles containing methemoglobin (and therefore, deprived of oxygen transporting capabilities), and washed rat red blood cells were used as controls.
    Design: Prospective, randomized, controlled trial.
    Setting: Department of Surgery, School of Medicine, Keio University.
    Subjects: Twenty-seven male Wistar rats.
    Interventions: The rats were anesthetized with an intraperitoneal injection of sodium pentobarbital (50 mg/kg). Catheters (PE-20 tubing, outer diameter 0.8 mm, inner diameter 0.5 mm) were introduced into the right jugular vein for infusion and the right common carotid artery for blood withdrawal and mean arterial pressure measurements. The left kidney was exposed by median abdominal incision, and a needle type polarographic oxygen electrode was placed in the left renal cortex for renal cortical tissue oxygen tension measurements.
    Measurements and Main Results: Phosphate buffered saline and methemoglobin vesicles were administered as nonoxygen-carrying fluids, and rat red blood cells as oxygen carrying fluid. Measurements included mean arterial pressure, arterial blood gas analysis, and renal cortical tissue oxygen tension as an indicator of systemic oxygen transport. In the rat red blood cell and hemoglobin vesicles groups, mean arterial pressure was sustained at the end of the exchange transfusion (82.3 +/- 27.5% and 73.5 +/- 11.5%, respectively, from the basal values). However, in the phosphate buffered saline and methemoglobin vesicles groups, mean arterial pressure decreased significantly (p <.05) (33.9 +/- 13.8% and 35.7 +/- 8.2%, respectively). Renal cortical tissue oxygen tension in the rat red blood cell and hemoglobin vesicles groups was sustained at a significantly higher level (p <.05) (83.5 +/- 9.3% and 75.0 +/- 11.9%, respectively) compared with the phosphate buffered saline and methemoglobin vesicles groups (44.9 +/- 12.8% and 58.3 +/- 6.2%, respectively) at the end of the exchange transfusion. Metabolic acidosis was more progressive in the phosphate buffered saline and methemoglobin vesicles groups, manifested as lower pH and base excess values. Platelet counts tended to decrease slightly in the hemoglobin vesicles and methemoglobin vesicles groups, but the changes were not significant.
    Conclusions: Hemoglobin vesicles have an oxygen transporting capability almost equivalent to rat red blood cells and can be considered as a potential artificial oxygen carrier.

  • Functional Evaluation of hemoglobin- and lipidheme-vesicles as red cell substitutes

    H Sakai, K Hamada, S Takeoka, H Nishide, E Tsuchida

    POLYMERS FOR ADVANCED TECHNOLOGIES   7 ( 8 ) 639 - 644  1996.08  [Refereed]

     View Summary

    The two kinds of veri cell substitutes, hemoglobin-vesicles (HbV) and lipidheme-vesicles (LihV, totally synthetic oxygen carrier), were evaluated in terms of physicochemical properties such as binding and dissociating reactions of ligands (CO, O-2 and NO), rheological and structural properties. Carbonylation of Hb during the purification of Hb and the preparation of HbV is effective to prevent Hb denaturation. The rates of oxygenation of both HbV and LihV are faster than that of I ed blood cells (RBC). Their oxygen affinities (P-50, HbV, 32 mmHg; LihV, 43 mmHg, cf. RBC, 28 mmHg) can be controlled to transport a sufficient amount of oxygen comparable with that of RBC. The smaller sizes of vesicles are advantageous for prompt ligand reaction and low viscosity. Both HbV and RBC show about 100 times less vasoconstrictive effects than stripped Hb. HbV shows only one sixth of the slow binding rate of NO (=endothelial derived relaxation factor) in comparison with stripped Hb. Inhibition of vasoconstriction by those vesicles is discussed from the kinetic data.

  • Electrochemical measurement of facilitated oxygen transport through a polymer membrane containing cobaltporphyrin as a fixed carrier

    T Suzuki, H Yasuda, H Nishide, XS Chen, E Tsuchida

    JOURNAL OF MEMBRANE SCIENCE   112 ( 2 ) 155 - 160  1996.04  [Refereed]

     View Summary

    Oxygen permeation through solid polymer membranes is measured electrochemically by detecting the reduction current of the permeated oxygen on a carbon electrode. This method is especially effective for the measurement of facilitated oxygen transport through polymer membranes containing oxygen-specific fixed carriers, such as cobaltporphyrins, because of its high sensitivity to low permeated or downstream oxygen pressure and because it is an equal pressure process suitable for the measurement of brittle membranes with high contents of carrier molecule.

  • Specific oxygen-binding to a polymer-supported N,N'-disalicylidenethylenediaminocobalt complex

    H Nishide, E Soda, H Mizuma, E Tsuchida

    MACROMOLECULAR SYMPOSIA   105   191 - 197  1996.03  [Refereed]

     View Summary

    A poly mer membrane containing N'N-disalicylidenethylene-diaminocobalt (Co(salen)) was prepared. The Co(salen) supported in the polymer not only worked as a reversible and specific oxygen-adsorbent but discontinuously bound oxygen at the atmospheric oxygen partial pressure of ca. 15 cmHg to give all on-off-like oxygen-binding curve. Oxygen permeation through the Co(salen) membrane was also augmented in the higher upstream oxygen pressure region, which was caused by the specific oxygen-binding to the Co(salen) fixed in the membrane.

  • Synthesis of and ferromagnetic coupling in poly(phenylenevinylene)s bearing built-in t-butyl nitroxides

    H Nishide, T Kaneko, S Toriu, Y Kuzumaki, E Tsuchida

    BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN   69 ( 2 ) 499 - 508  1996.02  [Refereed]

     View Summary

    Poly[[2- or 4-[N-t-butyl-N-(triethylsiloxy- or t-butyldimethylsiloxy)amino]-1,4- or 1,2-phenylene]vinylene] was synthesized by polymerizing 4- or 2-bromo-2- or 4-[N-t-butyl-N- (triethylsiloxy- or t-butyldimethylsiloxy)amino] styrene with a palladium catalyst, respectively. They were deprotected and chemically oxidized to yield poly(1,4- or 1,2-phenylenevinylene)s bearing a 2- or 4-substituted built-in nitroxide radical. The polyradicals were chemically stable, and their spin concentration was increased to 0.8 spin/unit. A SQUID measurement which included the corresponding diradicals and triradicals indicated that a partial, but strong, intramolecular ferromagnetic coupling was established through the conjugated backbone, despite a spin defect in the side radical moiety, for the poly(1,2-phenylenevinylene) bearing 4-substituted built-in nitroxide radical.

  • UPS study of poly(phenylenevinylene)s substituted with hexyloxy, phenoxy, and nitroxy residues

    T Kaneko, E Ito, K Seki, E Tsuchida, H Nishide

    POLYMER JOURNAL   28 ( 2 ) 182 - 184  1996  [Refereed]

  • FT pulsed ESR/electron spin transient nutation (ESTN) spectroscopy applied to high-spin systems in solids; Direct evidence of a topologically controlled high-spin polymer as models for quasi ID organic ferro- and superpara-magnets

    Takui, T, Sato, K, Shiomi, D, Itoh, K, Kaneko, T, Tsuchida, E, Nishide, H

    Molecular Crystals and Liquid Crystals Science and Technology Section A: Molecular Crystals and Liquid Crystals   278-279   155 - 176  1996  [Refereed]

  • Theoretical study of effective exchange integrals for ferromagnetic phenylenevinylene polymers with nitroxides. Possibilities of organic ferro- or ferri-magnetic solids

    Maruta, G, Yamaki, D, Mori, W, Yamaguchi, K, Nishide, H

    Molecular Crystals and Liquid Crystals Science and Technology Section A: Molecular Crystals and Liquid Crystals   278-279   19 - 28  1996  [Refereed]

  • Poly(phenylenevinylene)-attached phenoxyl radicals: Ferromagnetic interaction through planarized and マ�-conjugated skeletons

    Nishide, H, Kaneko, T, Nii, T, Katoh, K, Tsuchida, E, Lahti, P.M

    Journal of the American Chemical Society   118 ( 40 ) 9695 - 9704  1996  [Refereed]

  • Analysis of facilitated oxygen transport in a liquid membrane of hemoglobin

    XS Chen, H Nishide, E Tsuchida

    BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN   69 ( 1 ) 255 - 259  1996.01  [Refereed]

     View Summary

    A liquid membrane containing bovine hemoglobin (Hb) as an oxygen carrier was prepared, and oxygen permeation through the membrane was measured by the electrochemical reduction of the permeated oxygen. The oxygen permeation was facilitated, as analyzed by a dual-mode model, to give permeation parameters of the membranes such as the diffusion coefficient (D-Hb) Of the mobile carrier Hb and the solution-diffusion coefficient of oxygen (D-O2). The facilitated permeation was the product of the Hb concentration ([Hb](0)) and D-Hb in the membrane solution. D-Hb decreased with [Hb](0) or the solution viscosity; the maximum of the oxygen permeability (6.2 x 10(-8) cm(3)(STP)cm cm(-2)s(-1) cmHg(-1) at the feed stream oxygen pressure of 0.54 cmHg) was observed at [Hb](0) = 12.8 g dl(-1), where the facilitation factor and the oxygen/nitrogen permselectivity were ca. 10 and 18, respectively.

  • Physical properties of hemoglobin vesicles as red cell substitutes

    H Sakai, K Hamada, S Takeoka, H Nishide, E Tsuchida

    BIOTECHNOLOGY PROGRESS   12 ( 1 ) 119 - 125  1996.01  [Refereed]

     View Summary

    Hemoglobin vesicles (HbV) as red cell substitutes were prepared from a purified carbonylhemoglobin (HbCO) solution and a lipid mixture composed of phospholipids, cholesterol, and cr-tocopherol. The diameter was controlled to 251 +/- 87 nm using an extrusion method; the vesicles penetrated through the membrane filters with regulated pore sizes. After the ligand exchanging reaction (HbCO --> HbO(2)), the oxygen affinity (P-50) Of HbV was 32 Torr, which was controlled with the coencapsulation of pyridoxal 5'-phosphate. The rate of metHb formation in HbV was nonenzymatically reduced with the coencapsulation of DL-homocysteine. The Hb concentration of the HbV suspension, which was dispersed in a phosphate buffered saline solution (pH 7.4), was controlled at 10 g/dL. At this concentration, the total lipid concentration was 6.2 g/dL and the viscosity, 2.6 cP (230 s(-1)), was lower than that of the blood (4.4 cP). The HbV suspension showed a typical non-Newtonian flow for a particle dispersion and agreed well with the Casson model. The viscosity at shear rates lower than 23 s(-1) showed a maximum with increasing the mixing ratio of human blood, plasma, or albumin, while no maximum was observed for the mixture with washed red blood cells. The aggregates of HbV are formed by interaction with plasma proteins, including albumin, while the aggregates reversibly dissociate at higher shear rate.

  • Oxygen transporting ability of lipidheme microspheres as a totally synthetic red cell substitute

    Komatsu, T, Kuronuma, A, Muramatsu, Y, Nishide, H, Tsuchida, E, Kakizaki, T, Kobayashi, K

    Artificial Organs Today (Japan)   5 ( 3 ) 207 - 215  1996  [Refereed]

  • Intrachain Ferromagnetic Spin Alignment in マ�-Conjugated Polyradicals with a Poly(phenylenevinylene) Chain

    Nishide, H

    ACS Symposium Series   644   247 - 257  1996  [Refereed]

  • CHEMICALLY SPECIFIC SURFACE-DIFFUSION OF OXYGEN THROUGH A POROUS MEMBRANE MODIFIED WITH COBALT PORPHYRIN ON ITS PORE SURFACE

    H NISHIDE, T SUZUKI, R NAKAGAWA, K ITAKURA, E TSUCHIDA

    JOURNAL OF PHYSICAL CHEMISTRY   99 ( 32 ) 12312 - 12317  1995.08  [Refereed]

     View Summary

    Chemically specific surface diffusion of oxygen was observed on a porous glass membrane modified on its pore surface with cobalt porphyrin (CoP) which binds oxygen specifically and reversibly from air. The membrane displayed both permselectivity for oxygen and high permeability. The enhanced and specific diffusion of oxygen was mathematically analyzed with a parallel model involving surface diffusion of oxygen via CoP fixed on the pore surface and gas phase or Knudsen diffusion. alpha(3) beta-CoP was characterized by larger rate constants of oxygen binding (k(on)) and oxygen dissociation (k(off)), gave a larger surface diffusion constant of oxygen (D-S similar to 10(-4) cm(2) s(-1)), and brought about higher oxygen permeability through the membrane.

  • SELF-ASSEMBLED LIPIDPORPHYRIN BILAYER VESICLES, MICROSTRUCTURE AND DIOXYGEN BINDING IN AQUEOUS-MEDIUM

    E TSUCHIDA, T KOMATSU, K ARAI, K YAMADA, H NISHIDE, JH FUHRHOP

    LANGMUIR   11 ( 6 ) 1877 - 1884  1995.06  [Refereed]

     View Summary

    An amphiphilic tetraphenylporphyrinatometal (Zn, Fe) derivative having four dialkylglycerophosphocholine groups on one side of the ring plane (lipidporphyrin) was easily dispersed in an aqueous medium to give a red, stable dispersion. Based on electron microscopy, lipidporphyrins themselves produced spherical unilamellar vesicles with a diameter of ca. 100 nm. The thickness of the membrane (9.5 +/- 0.5 nm) corresponded to a bilayer of the lipidporphyrin (4.6 nm); the ratio of the lipidporphyrin molecules in the outer and inner layers was 1.57. The lipidporphyrinatozinc(II) vesicle displayed some characteristics of a J-aggregate: (i) a red-shifted Soret band (425 --> 438 nm), (ii) no fluorescence quenching, and (iii) a reduced triplet-state lifetime. Simple exciton calculations indicate that the porphyrin squares located in the outer and inner layers formed a J-aggregate with an average angle of 47 degrees. A vesicle composed of the lipidporphyrinatoiron(II) coordinated with an alkylimidazole reversibly formed a stable dioxygen adduct. The O-2-binding equilibrium and kinetic parameters were determined. This vesicle has the ability to act as a totally synthetic O-2 carrier under physiological conditions (pH 7.4, 37 degrees C).

  • MONOLAYERED OCTOPUS-PORPHYRIN VESICLE - MICROSTRUCTURE AND OXYGEN-BINDING IN AQUEOUS-MEDIUM

    E TSUCHIDA, T KOMATSU, K ARAI, K YAMADA, H NISHIDE, C BOTTCHER, JH FUHRHOP

    JOURNAL OF THE CHEMICAL SOCIETY-CHEMICAL COMMUNICATIONS   ( 10 ) 1063 - 1064  1995.05  [Refereed]

     View Summary

    The amphiphilic tetraphenylporphin derivative having four dialkylglycerophosphocholine groups on both sides of the ring plane (octopus-porphyrin) forms spherical monolayered vesicle membranes in water with diameters of ca, 100 nm; the vesicle constituted by octopus-porphyrinatoiron(II)/1-dodecyl-2-methylimidazole (DMIm) can reversibly bind dioxygen at 25 degrees C.

  • SYNTHESIS AND O-2-BINDING PROPERTIES OF TETRAPHENYLPORPHYRINATOIRON(II) DERIVATIVES BEARING A PROXIMAL IMIDAZOLE COVALENTLY BOUND AT THE BETA-PYRROLIC POSITION

    E TSUCHIDA, T KOMATSU, S KUMAMOTO, K ANDO, H NISHIDE

    JOURNAL OF THE CHEMICAL SOCIETY-PERKIN TRANSACTIONS 2   ( 4 ) 747 - 753  1995.04  [Refereed]

     View Summary

    5,10,15,20-Tetrakis(o-pivalamidophenyl)porphyrins (TPVP) and their iron(II) derivatives bearing a proximal imidazole covalently bound at the 2-(beta-pyrrolic) position have been synthesized. The visible absorption maxima (lambda(max)) of the 2-substituted TPVP with an electron withdrawing group attached is shifted toward the red region (7-11 nm) compared with that of the original TPVP. The iron(II) complexes having an imidazolyl group at the beta-pyrrolic position were five coordinated species with an intramolecularly bound base under argon and reversibly formed a stable dioxygen adduct in response to O-2-pressure in toluene at 25 degrees C. These molecules act as efficient dioxygen carrying molecules. The kinetics of O-2 binding to the 2-substituted Fe(TPVP) complexes are described.

  • Electrochemical study of the nitroxyl radical derivatives built in the マ�-conjugated poly(phenylenevinylene) skeleton

    Toriu, Shuichi, Kaneko, Takashi, Nishide, Hiroyuki, Tsuchida, Eishun

    Polymers for Advanced Technologies   6 ( 11 ) 707 - 710  1995  [Refereed]

  • Poly[(N-oxyamino) and (oxyphenyl)phenylenevinylene]s: Magnetically coupled polyradicals in the chain

    Kaneko, Takashi, Toriu, Shuichi, Nii, Takeshi, Tsuchida, Eishun, Nishide, Hiroyuki

    Molecular Crystals and Liquid Crystals Science and Technology Section A: Molecular Crystals and Liquid Crystals   272   153 - 160  1995  [Refereed]

  • New aspects of high-spin chemistry

    K Itoh, T Takui, Y Teki, K Sato, D Shiomi, T Kinoshita, T Nakamura, T Momose, T Shida, T Okuno, A Izuoka, T Sugawara, T Kaneko, E Tsuchida, H Nishide

    MOLECULAR CRYSTALS AND LIQUID CRYSTALS SCIENCE AND TECHNOLOGY SECTION A-MOLECULAR CRYSTALS AND LIQUID CRYSTALS   271   129 - 146  1995  [Refereed]

     View Summary

    As a novel high-spin molecule, a through-bond spin-frustrated organic molecule 4, 4', 4 ''-trisdiphenylmethyleneamine (TDMA) and its anion and cation was studied by cw-ESR spectroscopy. TDMA is a spin frustrated system composed of three S=1 units coupled antiferromagnetically. This molecule was shown to have a triplet ground-state which is asymmetrical in its exchange interaction as well as its molecular conformation. The TDMA ions were generated at low temperature via successive radiolysis and photolysis of its diazo precursor. It was shown that the ground states of the anion and cation are quartet and sextet, respectively. This means that upon ionization the ground state changed from the intermediate-spin state of TDMA to the high-spin state of the ions, showing the interrelation between spin alignment and excess charge in a molecular field. On the other hand, in order to identify and discriminate the spin multiplicities of complicated spin assemblages in amorphous materials, we have developed electron spin transient nutation spectroscopy based on FT pulsed ESR and applied it to a pseudo one-dimensional high-spin polymer with effective spin S greater than or equal to 2.

  • マ�-conjugated polyradicals with poly(phenylene-vinylene) skeleton and their through-bond and long-range interaction

    Nishide, Hiroyuki, Kaneko, Takashi, Toriu, Shuichi, Katoh, Kohya, Takahashi, Masahiro, Tsuchida, Eishun, Yamaguchi, Kizashi

    Molecular Crystals and Liquid Crystals Science and Technology Section A: Molecular Crystals and Liquid Crystals   272   131 - 138  1995  [Refereed]

  • FT pulsed ESR/electron spin transient nutation spectroscopy in the study of molecular based magnetism: Applications to high-spin polymers and ferromagnetic materials

    T Takui, K Sato, D Shiomi, K Itoh, T Kaneko, E Tsuchida, H Nishide

    MOLECULAR CRYSTALS AND LIQUID CRYSTALS SCIENCE AND TECHNOLOGY SECTION A-MOLECULAR CRYSTALS AND LIQUID CRYSTALS   271   191 - 212  1995  [Refereed]

     View Summary

    Recently, organic high-spin polymers and clusters have been emerging. With the increasing effective molecular spin quantum number S and molecular weight of the polymers, however, cw ESR spectroscopy manifests its inherent disadvantages in discriminating high spins from S=1/2 and in determining the S's for the complex mixture of various spin assemblages. An electron spin transient nutation method based on pulsed ESR spectroscopy has been for the first time applied to a quasi 1D high-spin polymer as one of the most complex amorphous spin assemblages, identifying that the polymer is comprised of high-spin assemblages with the S's greater than two. It can be concluded that electron spin transient nutation spectroscopy is a facile and useful method for the exclusive identification of S and ESR transitions even for the cases of apparently vanishing fine-structure splittings and for spin systems with residual fine-structure terms in the spin Hamiltonian. Fundamental bases for the transient nutation method are described, emphasizing inherent advantages in the nutation spectroscopy from the methodological viewpoint. The salient features of multiple-quantum nutations have been disclosed in this work.

  • Through-bond and long-range ferromagnetic spin alignment in a マ�-conjugated polyradical with a poly(phenylenevinylene) skeleton

    Nishide, H, Kaneko, T, Nii, T, Katoh, K, Tsuchida, E, Yamaguchi, K

    Journal of the American Chemical Society   117 ( 1 ) 548 - 549  1995  [Refereed]

  • High-spin alignment in マ�-conjugated polyradicals: A magnetic polymer

    Nishide, H

    Advanced Materials   7 ( 11 ) 937 - 941  1995  [Refereed]

  • CHARACTERISTIC BEHAVIOR OF THE COMPLEXATION OF COPPER(II) WITH POLYMER-BOUND VINYLIMIDAZOLE LIGANDS

    Y KURIMURA, T ABE, Y USUI, E TSUCHIDA, P NISHIDE, G CHALLA

    JOURNAL OF THE CHEMICAL SOCIETY-FARADAY TRANSACTIONS   90 ( 23 ) 3563 - 3566  1994.12  [Refereed]

     View Summary

    Some polymer ligands of N-vinylimidazole-co-N-vinylpyrrolidone (Plm) having different mole fractions of N-vinylpyrrolidone have been prepared. Successive formation constants for the complexation of Cu-II with these Plms in aqueous solutions have been determined by means of spectrum deconvolution at pH 3.5. The present results demonstrate that the successive formation constants are given by K-1=[CuL]/[Cu][L], K-2= [CuL(2)]/[CuL], K-3= [CuL]/[CuL(2)] and K-4 = [CuL(4)]/[CuL(3)] (charge omitted, L = imidazole residue on Plm). The results clearly indicate that the concentration ratio, [CuL] : [CuL(2)] : [CuL(3)] : [CuL(4)], is largely constant for a given Pim when the concentration of imidazole residues is varied. The values of K-2, K-3 and K-4 decrease with increasing mole fraction of vinylpyrrolidone residues (VPRo) in the Plms. The successive formation constants increase in the order K-2 < K-3 < K-4 for poly(N-vinylimidazole), whereas the reverse (i.e. K-2 > K-3 > K-4) is found for Plm with a VPRo mole fraction of 0.8. Above this VPRo mole fraction, CuL(4) species are rarely formed. These results also suggest that the distributions of Cut, species in Cu-II-Plm solutions can be controlled by adjusting the content of VPRo in the Plm.

  • SULFIDE BOND FORMATION FOR THE SYNTHESIS OF POLY(THIOARYLENE) THROUGH OXIDATION OF SULFUR CHLORIDE WITH AROMATICS

    K YAMAMOTO, M JIKEI, K MIYATAKE, J KATOH, H NISHIDE, E TSUCHIDA

    MACROMOLECULES   27 ( 15 ) 4312 - 4317  1994.07  [Refereed]

     View Summary

    A new homogeneous series of hydrocarbon polymers having phenoxy and thiophenoxy units in the main chain were prepared by oxidative polymerization of alpha,omega-diphenoxyalkenes (m = 2-8, 10) with S2Cl2. Polymers with weight-average molecular weights in the range of 4800-33500 have been obtained in high yields (>94%). The effect of the chain length of the methylene units on the thermal properties of the polymers is discussed. Increasing the length of the methylene units results in a decrease in the glass transition temperature (T(g)) of the polymers. An alternating odd-even effect in melting temperatures (T(m)) and molecular weights is observed. The resulting polymers having even numbers of methylene units possess a higher melting temperature and lower molecular weight than those of the odd numbered ones. Polymerization of S2Cl2 with other aromatic compounds, such as p-xylene, durene, and diphenyl ether, is also demonstrated to yield the corresponding poly(thioarylene)s. The polymerization proceeds via a cationic mechanism through the oxidation of the disulfide bond.

  • SEMIEMPIRICAL INVESTIGATION OF STILBENE-LINKED DIRADICALS AND MAGNETIC STUDY OF THEIR BIS(N-TERT-BUTYLNITROXIDE) VARIANTS

    N YOSHIOKA, PM LAHTI, T KANEKO, Y KUZUMAKI, E TSUCHIDA, H NISHIDE

    JOURNAL OF ORGANIC CHEMISTRY   59 ( 15 ) 4272 - 4280  1994.07  [Refereed]

     View Summary

    The electronic states of open-shell stilbene diradicals were st;hied. Previously used semiempirical MO-CI methods were applied to stilbenes having dimethylene, dioxyl, and dinitroxide centers in o,o'-, o,m'-, o,p'-, m,m'-, m,p'-, and p,p'-substitution patterns, and the various singlet-triplet energy gaps were computed to predict qualitative ground state spin multiplicities. Singlet and triplet spin states were essentially degenerate in the m,m'-isomers of disjoint connectivity, while nondisjoint o,m'- and m,p'-isomers had triplet computed ground states. Nitroxide-based diradicals showed considerably smaller computational exchange coupling energies than did other diradical models studied. As a tests of these computations, stilbenes with two N-tert-butyl nitroxide groups at the o,m'-, m,m'-, and m,p'-positions were prepared, and their magnetic properties were studied by ESR and-magnetic susceptibility measurements. The m,m'- and m,p'-isomers were found experimentally to have singlet and triplet ground states, respectively, in accord with the qualitative computed predictions.

  • MAGNETIC CHARACTERIZATION AND COMPUTATIONAL MODELING OF POLY(PHENYLACETYLENE)S BEARING STABLE RADICAL GROUPS

    H NISHIDE, T KANEKO, M IGARASHI, E TSUCHIDA, N YOSHIOKA, PM LAHTI

    MACROMOLECULES   27 ( 11 ) 3082 - 3086  1994.05  [Refereed]

     View Summary

    The magnetic properties of poly(phenylacetylene)s with radical groups at the paraposition, poly[(3,5-di-tert-butyl-4-oxyphenyl)acetylene] (1),poly[[4-[(3,5-di-tert-butyl-4-oxyphenyl)(3,5-di-tert-butyl-4-oxocyclohexa-2,5-dien-1-ylidene)methyl]phenyl]acetylene] (2), and poly[[4-(N-tert-butyl-N-oxyamino)phenyl]acetylene] (3), were studied with a SQUID magnetometer. The magnetization and magnetic susceptibility indicated unexpected antiferromagnetic interactions between the radical sites. The exchange interaction observed in these conjugated polyradicals was discussed in connection with their computationally modeled structures.

  • ENHANCED OXYGEN DIFFUSION THROUGH A POROUS MEMBRANE CHEMICALLY-MODIFIED WITH COBALT PORPHYRIN ON ITS PORE SURFACE

    H NISHIDE, T SUZUKI, R NAKAGAWA, E TSUCHIDA

    JOURNAL OF THE AMERICAN CHEMICAL SOCIETY   116 ( 10 ) 4503 - 4504  1994.05  [Refereed]

  • COBALT PORPHYRIN-MEDIATED OXYGEN-TRANSPORT IN A POLYMER MEMBRANE - EFFECT OF THE COBALT PORPHYRIN STRUCTURE ON THE OXYGEN-BINDING REACTION, OXYGEN-DIFFUSION CONSTANTS, AND OXYGEN-TRANSPORT EFFICIENCY

    H NISHIDE, T SUZUKI, H KAWAKAMI, E TSUCHIDA

    JOURNAL OF PHYSICAL CHEMISTRY   98 ( 19 ) 5084 - 5088  1994.05  [Refereed]

     View Summary

    New derivatives of (meso-alpha,alpha,alpha,alpha-tetrakis(o-pivalamidophenyl)porphinato)cobalt (CoPs) were characterized by oxygen-binding equilibrium and rate constants of the cobalt centered in the porphyrins. They depended on the structure of the porphyrin; for example, the rate constants of oxygen binding and dissociation (k(on) and k(off)) for (alpha(3) beta-CoP4P (Chart 1) were 3 and 20 times as large as those for alpha(4)-CoB4P, respectively. Oxygen transport through the polymer membranes containing CoPs as the fixed oxygen carriers was facilitated and was affected by the oxygen-binding character or the structure of CoPs. The logarithmically linear correlation of the oxygen-dissociation rate constant of CoPs (k(off) = (3-66) X 10(3) s(-1)) with the diffusion constant of oxygen via CoPs fixed in the membranes (D-cc = (3-140) x 10(-9) cm(2) s(-1)) was given for those six CoP derivatives.

  • Synthesis of poly(2,5‐dimethylphenylene sulfide) through oxidative polymerization of sulfur chloride with p‐xylene

    Kenji Miyatake, Mitsutoshi Jikei, Junya Katoh, Kimihisa Yamamoto, Hiroyuki Nishide, Eishun Tsuchida

    Polymers for Advanced Technologies   5 ( 4 ) 216 - 220  1994  [Refereed]

     View Summary

    Poly(2,5‐dimethylphenylene sulfide) was prepared by oxidative polymerization of sulfur chloride with p‐xylene using 2,3‐dichloro‐5,6‐dicyano‐p‐benzoquinone (DDQ) as an oxidizing agent. The reaction proceeded efficiently under atmospheric pressure and at room temperature. The polymer formed had a high melting temperature and linear structure which was confirmed by spectroscopies. The effects of reaction time, solvent, temperature and oxidizing agent on polymerization are also discussed. Copyright © 1994 John Wiley &amp
    Sons, Ltd.

    DOI

  • Effect of carrier concentration on the facilitated oxygen transport in a polymer membrane

    Takayuki Suzuki, Hiroyuki Nishide, Keita Itakura, Eishun Tsuchida

    Polymers for Advanced Technologies   5 ( 5 ) 253 - 256  1994  [Refereed]

     View Summary

    Facilitated transport of oxygen in a solid Polymer membrane containing cobaltporphyrin (CoP) which carries oxygen specifically and reversibly, leads to permselectivity of oxygen against nitrogen in the membrane. The increase in concentration of the CoP carrier is expected to enhance the oxygen transport. The membranes of poly(octylmethacrylate‐co‐vinylimidazole) containing 0.8 ∼ 10 wt% CoP were prepared, and the effects of the CoP‐concentration on the transport and the diffusion constants of oxygen are studied. Although the induction period before the steady state of oxygen permeation was prolonged with the CoP concentration in the polymer membrane, the glass transition temperature (Tg) of the membrane was increased and the diffusion constants of oxygen were decreased with the CoP concentration to yield unexpected reduction of the oxygen permeation in the highly CoP loaded membrane. Copyright © 1994 John Wiley &amp
    Sons, Ltd.

    DOI

  • Oxygen‐binding property of hemoglobin films

    Jooeun Chung, Shinji Takeoka, Hiroyuki Nishide, Eishun Tsuchida

    Polymers for Advanced Technologies   5 ( 7 ) 385 - 389  1994  [Refereed]

     View Summary

    Oxygenated and deoxygenated hemoglobin films were obtained by drying corresponding hemoglobin solutions with maltose (≧0.3 M). The resulting hemoglobin films were homogeneous and smooth, and the methemoglobin formation in the oxyhemoglobin film was well suppressed. The dry, rigid networks of maltose molecules work to preserve the conformation of hemoglobin against the removal of water. The coordination of oxygen to the deoxygenated hemoglobin film was slow and saturated up to 50%, while nearly 100% saturation was achieved if the film contained a residual moisture of 8.7%. Copyright © 1994 John Wiley &amp
    Sons, Ltd.

    DOI

  • ADSORPTION OF CALCIUM-ION AND OF HUMAN TOOTH ENAMEL TO METHACRYLIC-ACID RESIN

    T FUJIMORI, T KANEKO, H NISHIDE, E TSUCHIDA

    KOBUNSHI RONBUNSHU   51 ( 1 ) 1 - 4  1994  [Refereed]

     View Summary

    Poly(methacrylic acid-co-triethyleneglycol dimethacrylate) adsorbed calcium ion effectively. The adsorption obeyed Langmuir's isotherm, which indicated adsorption site [-COO-]Ca-2(2+) and its stability constant (10(4) l/mol). The resin interacted with calcium of human tooth enamel, which was adhered with the resin.

  • Interaction between phospholipid assemblies and hemoglobin (Hb)

    Takeoka, Shinji, Terase, Kouichiro, Yokohama, Hiroaki, Sakai, Hiromi, Nishide, Hiroyuki, Tsuchida, Eishun

    Journal of Macromolecular Science - Pure and Applied Chemistry   A31 ( 1 ) 91 - 108  1994  [Refereed]

  • Suppression of metHb formation in Hb-vesicles by glutathione

    Yokohama, H, Seino, Y, Chung, J.E, Sakai, H, Takeoka, S, Nishide, H, Tsuchida, E

    Japanese Journal of Artificial Organs   23 ( 3 ) 868 - 871  1994  [Refereed]

  • In vivo O2-transport of totally synthetic artificial red cell (lipid-heme-microsphere)

    Komatsu, T, Muramatsu, Y, Nishide, H, Tuchida, E, Kakizaki, T, Kobayashi, K

    Japanese Journal of Artificial Organs   23 ( 3 ) 849 - 853  1994  [Refereed]

  • CHARACTERISTICS OF HB-VESICLES AND ENCAPSULATION PROCEDURE

    S TAKEOKA, H SAKAI, K TERASE, H NISHIDE, E TSUCHIDA

    ARTIFICIAL CELLS BLOOD SUBSTITUTES AND IMMOBILIZATION BIOTECHNOLOGY   22 ( 3 ) 861 - 866  1994  [Refereed]

     View Summary

    The performance of Hb-vesicles depends on the weight ratio of Hb to lipid ([Hb]/[Lipid]). This value is improved by lowering the number of bilayer membrane of the vesicle and raising the concentration of Hb in the interior of the vesicle. Maximum [Hb]/[Lipid] ratio was obtained at ca. pH 7, that would relate to the isoelectric point (pl) of Hb at 25 degrees C. On the other hand, the [Hb]/[Lipid] ratio decreased with ionic strength and increased with lowering temperature. The Hb-vesicles encapsulating 40 g/dl Hb with only one bilayer membrane were isolated by using the difference in the density of the vesicles.

  • Two types of totally artificial red blood cell substitutes liposome embedded heme(L/H) and lipidheme/microsphere(LHM)

    Kobayashi, K, Kakizaki, T, Komatsu, T, Nishide, H, Tsuchida, E

    Artificial Cells, Blood Substitutes, and Immobilization Biotechnology   22 ( 3 ) 895 - 900  1994  [Refereed]

  • CONVENIENT METHOD TO PURIFY HEMOGLOBIN

    H SAKAI, S TAKEOKA, H NISHIDE, E TSUCHIDA

    ARTIFICIAL CELLS BLOOD SUBSTITUTES AND IMMOBILIZATION BIOTECHNOLOGY   22 ( 3 ) 651 - 656  1994  [Refereed]

     View Summary

    A convenient method to purify Hb solution from outdated RBC has been established for the starting material of Hb-based blood substitutes. To prevent MetHb formation during the procedure, Hb in RBC was carbonylated in advance. Then RBC was mixed with organic solvent for hemolysis and centrifuged for removal of stroma. The resulting SFHb solution was heated at 60 degrees C and generated precipitates were removed out by centrifugation. The purity of Hb (25 g/dl) was confirmed by SDS-PAGE. IEF and oxygen binding property of the Kb solution also guaranteed its purity and no denaturation of Hb. This method is applicable to large scale production of the purified Hb for the starting material of Hb-based blood substitutes.

  • STRUCTURE AND SOLUTION PROPERTIES OF LIPIDHEME-MICROSPHERE

    T KOMATSU, H NISHIDE, E TSUCHIDA

    ARTIFICIAL CELLS BLOOD SUBSTITUTES AND IMMOBILIZATION BIOTECHNOLOGY   22 ( 3 ) 855 - 860  1994  [Refereed]

     View Summary

    Triglyceride microsphere emulsified with phospholipid derivative of heme (5,10,15,20-tetrakis[alpha,alpha,alpha,alpha-o-[2,2-dimethyl-20-[2-(trimethylammonioethoxy) phosphonatoxy]eicosanamido]phenyl]porphinatoiron(II); lipidheme) provides a totally synthetic artificial red cell (lipidheme-microsphere; LH-M). Its structure, solution properties and O-2, binding ability are described. The particle diameter of the LH-M was ca. 90 nm phi elucidated by electron microscopy. Viscosity of the LH-M suspension (similar to 1.5 cP) was much lower than that of human blood and the viscosity of mixed system of LH-M/human blood (1/1(v/v)) was 2.5 cP. Specific gravity, osmotic pressure, and colloid osmotic pressure of the LH-M suspension also satisfied the physiological needs. The LH-M can bind O-2 reversibly in response to O-2 pressure (P-50(O-2): 41 torr (pH 7.4, 37 degrees C)). O-2 solubility of the LH-M was more than that of human blood caused by its high heme concentration.

  • LIPIDHEME-MICROSPHERE (LH-M) A NEW-TYPE OF TOTALLY SYNTHETIC OXYGEN CARRIER AND ITS OXYGEN-CARRYING ABILITY

    T KAKIZAKI, K KOBAYASHI, T KOMATSU, H NISHIDE, E TSUCHIDA

    ARTIFICIAL CELLS BLOOD SUBSTITUTES AND IMMOBILIZATION BIOTECHNOLOGY   22 ( 3 ) 933 - 938  1994  [Refereed]

     View Summary

    We have succeeded in synthesizing a new type of totally artificial oxygen carrier which was produced by covering oil droplets (microsphere) with synthetic hemes (LH-M). We studied its oxygen-transporting ability in hemorrhagic dogs.
    Four beagles weighing about 8 kg were studied. Under controlled ventilation, exchange-transfusion of 30 ml/kg was carried out. Cardiac output, hemoglobin and LH-M concentration in the blood, and blood gas were measured to 5 hours after intravenous injection of LK-M solution.
    LH-M delivered 15.7 to 22.3 ml/min (11 to 16 %) of oxygen to the tissue and 5.5 to 8.2 ml/min (11 to 17 %) of oxygen was consumed from LH-M to 5 hours after intravenous injection. Its half-life time in the blood stream was about 12 hours. It was confirmed that LK-M transported oxygen and released it to the tissue in vivo.

  • Two types of totally synthetic oxygen carrier: Liposome embedded heme(L/H) and lipid heme microshere(LH-M)

    Kobayashi, K, Nishide, H, Tsuchida, E

    Artificial Cells, Blood Substitutes, and Immobilization Biotechnology   22 ( 5 )  1994  [Refereed]

  • A new totally synthetic oxygen carrier: Lipid heme microshere(LHM)

    Kobayashi, K, Kakizaki, T, Izumi, Y, Takeoka, S, Komatsu, T, Nishide, H, Tsuchida, E

    Artificial Cells, Blood Substitutes, and Immobilization Biotechnology   22 ( 5 )  1994  [Refereed]

  • PURIFICATION OF CONCENTRATED HEMOGLOBIN USING ORGANIC-SOLVENT AND HEAT-TREATMENT

    H SAKAI, S TAKEOKA, H YOKOHAMA, Y SEINO, H NISHIDE, E TSUCHIDA

    PROTEIN EXPRESSION AND PURIFICATION   4 ( 6 ) 563 - 569  1993.12  [Refereed]

  • LIPID PORPHYRIN FIBERS - MORPHOLOGY AND INCORPORATION INTO PHOSPHOLIPID VESICLE

    E TSUCHIDA, T KOMATSU, N TOYANO, S KUMAMOTO, H NISHIDE

    JOURNAL OF THE CHEMICAL SOCIETY-CHEMICAL COMMUNICATIONS   ( 23 ) 1731 - 1733  1993.12  [Refereed]

     View Summary

    Protoporphyrin IX derivatives having two alkylphosphocholine groups (lipid-porphyrins) forms stable fibrous aggregates in aqueous medium; fibres have been spontaneously incorporated into the bilayer of the phospholipid vesicle.

  • SYNTHESIS OF OLIGO(2,3,5,6-TETRAMETHYLPHENYLENE SELENIDE)

    E TSUCHIDA, M JIKEI, K MIYATAKE, K YAMAMOTO, H NISHIDE

    MACROMOLECULES   26 ( 17 ) 4732 - 4733  1993.08  [Refereed]

  • POLY[[4-(N-TERT-BUTYL-N-HYDROXYAMINO)PHENYL]ACETYLENE] AND THE MAGNETIC PROPERTY OF ITS RADICAL DERIVATIVE

    H NISHIDE, T KANEKO, N YOSHIOKA, H AKIYAMA, M IGARASHI, E TSUCHIDA

    MACROMOLECULES   26 ( 17 ) 4567 - 4571  1993.08  [Refereed]

     View Summary

    [4-(N-tert-Butyl-N-hydroxyamino)phenyllacetylene (7) was synthesized and polymerized to yield a solvent-soluble polyacetylene: poly[[4-(N-tert-butyl-N-hydroxyamino)phenyl]acetylene] (8). Oxidation of the polymer gave its radical derivative: the ESR spectrum showed a broad signal only in the DELTAm(s) = +/-1 region, and magnetic measurement with a SQUID magnetometer revealed an antiferromagnetic through-space interaction.

  • SYNTHESIS AND DIOXYGEN-BINDING PROPERTIES OF DOUBLE-SIDED PORPHYRINATOIRON(II) COMPLEXES BEARING COVALENTLY BOUND AXIAL IMIDAZOLE

    E TSUCHIDA, T KOMATSU, K ARAI, H NISHIDE

    JOURNAL OF THE CHEMICAL SOCIETY-DALTON TRANSACTIONS   ( 16 ) 2465 - 2469  1993.08  [Refereed]

     View Summary

    Double-sided porphyrinatoiron(II) complexes bearing covalently bound axial imidazole, 5-[2-(5-imidazolylvaleryloxy)-6-(pivaloyloxy)phenyl]-10,15,20-tris[2,6-bis(pivaloyloxy)phenyl]porphyrinato-iron(II) and 5-[2-(3,3-dimethylbutyryloxy)-6-(5-imidazolylvaleryloxy)phenyl]-10,15,20-tris[2,6-bis(3,3-dimethylbutyryloxy)phenyl]porphyrinatoiron(II), have been synthesized. On the basis of their absorption and H-1 NMR spectra, the axial imidazole group is co-ordinated. The complexes reversibly form stable dioxygen adducts in toluene at 25-degrees-C, and the kinetics of binding of 02 and CO has been investigated. When embedded in phospholipid unilamellar vesicles, the complexes possess the ability to transport dioxygen in an aqueous medium. The binding affinity of the pivaloyloxy derivative [P1/2(O2) = 27 Torr] is equal to that of a red blood cell suspension and the half-life of the dioxygen adduct formed was 1.5 d under physiological conditions (pH 7.4, 37-degrees-C).

  • OXOVANADIUM-CATALYZED OXIDATIVE POLYMERIZATION OF DIPHENYL DISULFIDES WITH OXYGEN

    K YAMAMOTO, E TSUCHIDA, H NISHIDE, M JIKEI, K OYAIZU

    MACROMOLECULES   26 ( 13 ) 3432 - 3437  1993.06  [Refereed]

     View Summary

    Oligo(p-phenylene sulfide) is synthesized through oxygen oxidative polymerization of diphenyl disulfide catalyzed by vanadyl acetylacetonate. The mechanistic studies reveal that two redox cycles [V(M)/V(IV) and V(IV)/V(V)] give rise to catalysis through a 2-electron transfer between diphenyl disulfide and molecular oxygen. The VO catalysts act as an excellent electron mediator to bridge a 1.0-V potential gap between the oxidation potential of disulfides and the reduction potential of oxygen. The VO-catalyzed oxygen oxidative polymerization provides pure oligo(p-phenylene sulfide)s containing an S-S bond. The polymeric product is of low molecular weight due to the insolubility of poly(p-phenylene sulfide) under these experimental conditions.

  • LIPID PORPHYRIN VESICLES - MORPHOLOGY AND O2 BINDING IN AQUEOUS-MEDIUM

    E TSUCHIDA, T KOMATSU, K ARAI, H NISHIDE

    JOURNAL OF THE CHEMICAL SOCIETY-CHEMICAL COMMUNICATIONS   ( 9 ) 730 - 732  1993.05  [Refereed]

     View Summary

    Amphilphilic tetraphenylporphin derivatives having four dialkylglycerophosphocholine groups on the ring plane (lipid-porphyrins) form spherical unilamellar vesicles of diameter ca. 100 nm in water; the vesicles composed of lipid-porphyrinatoiron(II)-1-dodecylimidazole (DIm), can bind dioxygen reversibly in aqueous medium.

  • OCTOPUS-PORPHYRINS - THEIR ASSEMBLY AND OXYGEN-BINDING IN AQUEOUS-MEDIUM

    T KOMATSU, K NAKAO, H NISHIDE, E TSUCHIDA

    JOURNAL OF THE CHEMICAL SOCIETY-CHEMICAL COMMUNICATIONS   ( 9 ) 728 - 730  1993.05  [Refereed]

     View Summary

    Amphiphilic tetraphenylporphyrins having four alkyl phosphocholine groups on each side of the ring plane (octopus-porphyrins) form fibrous aggregates in dilute aqueous solution; the vesicles, constituted by iron(II) derivative-1-dodecyl-2-methylimidazole (DMIm), have the ability to bind dioxygen reversibly in aqueous medium.

  • INVESTIGATION OF THE REACTIONS OF THE OH RADICAL WITH POLY(ACRYLIC ACID) AND POLY(METHACRYLIC ACID) IN AQUEOUS-SOLUTION USING THE TB3+ FLUORESCENCE PROBE

    H NISHIDE, MD CHO, T KAKU, Y OKAMOTO

    MACROMOLECULES   26 ( 9 ) 2377 - 2379  1993.04  [Refereed]

  • SYNTHESIS OF PORPHINATOIRONS HAVING AN ALKYL AMPHIPHILIC CHAIN AND THEIR O-2 BINDING-PROPERTIES IN LIPID BILAYERS

    E TSUCHIDA, H NISHIDE, E HASEGAWA, Y CHIKA, M FUKUZUMI, T KOMATSU

    JOURNAL OF INORGANIC BIOCHEMISTRY   49 ( 4 ) 255 - 264  1993.03  [Refereed]

     View Summary

    Synthesis and characterization of two amphiphilic tetraphenylporphinatoiron complexes having a glycerophosphocholine or an alkyl phosphoserine group are described. These porphinatoiron(II) complexes with 1-dodecyl-2-methyl-imidazole (L2MIm) were efficiently embedded in the bilayer of a phospholipid vesicle due to their high compatibility with lipids, similar to the heme substituted with four alkyl amphiphilic chains (lipid-heme). Oxygen transporting ability of the phospholipid vesicles embedded with hemes were similar to that of hemoglobin (Hb) in red blood cells.

  • PHOTOREACTION AND PHOTOINITIATION BEHAVIOR IN THE LIGHT-CURED DENTAL COMPOSITE RESINS

    Y FUJIMORI, T KANEKO, H NISHIDE, E TSUCHIDA

    KOBUNSHI RONBUNSHU   50 ( 6 ) 485 - 488  1993  [Refereed]

     View Summary

    Photoreaction of camphorquinone (CQ) and dimethylaminoethyl methacrylate (DMAEMA) and its initiation capability of MMA polymerization was studied as a model system for visible light-cured dental composite resins. The photo-sensitizer (CQ) produced CQ radical anion by irradiation in the presence of the reducing agent (DMAEMA) under N2. ESR signal intensity and the IR and UV-Vis absorption spectra of CQ carbonyl group decreased during irradiation, and the polymerization rate of MMA depended on the decrease in the CQ carbonyl group. The hydrogen abstraction reaction by CQ radical seemed to promote the polymerization of MMA. Atmospheric oxygen inactivated the CQ radical and reduced the polymerization.

  • Preparation conditions of human hemoglobin-vesicles covered with lipid membranes

    Takeoka, S, Sakai, H, Tsuchida, E, Nishide, H

    Japanese Journal of Artificial Organs   22 ( 2 ) 566 - 569  1993  [Refereed]

  • Lipidheme-microsphere (artificial red cell); solution properties and oxygen-transporting ability

    Komatsu, T, Arai, K, Kawai, N, Nishide, H, Tsuchida, E, Kakizaki, T, Kobayashi, K

    Japanese Journal of Artificial Organs   22 ( 2 ) 550 - 553  1993  [Refereed]

  • ANODIC-OXIDATION OF DIPHENYL DISULFIDES FOR PREPARATION OF OLIGO(P-PHENYLENE SULFIDE)S IN ACIDIC MEDIA

    K YAMAMOTO, E TSUCHIDA, H NISHIDE, S YOSHIDA, YS PARK

    JOURNAL OF THE ELECTROCHEMICAL SOCIETY   139 ( 9 ) 2401 - 2406  1992.09  [Refereed]

     View Summary

    Diphenyl disulfides yield oligo(p-phenylene sulfides) by an anodic oxidation in dichloromethane solution in the presence of protonic acids such as trifluoroacetic acid. The acid suppresses the nucleophilic reaction of the cationic active species and the electro-oligomerization of diphenyl disulfide proceeds through an electrophilic reaction of a cation formed anodic oxidation. The oxidation of diphenyl disulfide proceeds through a one-electron transfer and via phenyl-bis(phenylthio) sulfonium cation as an active species in this oligomerization, which was confirmed electrochemically. Upon adding benzoquinones and cerium acetylacetonate to the mixture, the oligomerization proceeds efficiently to give a high yield of the oligomer and can be carried out at a lower applied potential (1.7 to 0.8 V vs. Ag/AgCl).

  • POLY[(P-ETHYNYLPHENYL)HYDROGALVINOXYL] AND ITS POLYRADICAL DERIVATIVE WITH HIGH-SPIN CONCENTRATION

    N YOSHIOKA, H NISHIDE, T KANEKO, H YOSHIKI, E TSUCHIDA

    MACROMOLECULES   25 ( 15 ) 3838 - 3842  1992.07  [Refereed]

     View Summary

    [4-[(3,5-Di-tert-butyl-4-hydroxyphenyl)(3,5-di-tert-butyl-4-oxocyclohexa-2,5-dien-1-ylidene)methyl]phenyl]acetylene (6), was synthesized and polymerized to yield a solvent-soluble polyacetylene poly[[4-[(3,5-di-tert-butyl-4-hydroxyphenyl)(3,5-di-tert-butyl-4-oxocyclohexa-2,5-dien-1-ylidene)methyl]phenyl]acetylene] (5a). The polymer gave its polyradical derivative 5b through the chemical oxidation with active PbO2. 5b was stable, whose spin concentration could be increased up to 4.8 x 10(23) spins per molar monomer unit. ESR analysis indicated localization of unpaired electrons in the galvinoxyl residue. ESR analysis also suggested an exchange-narrowing and interpolymer dipole-dipole interaction.

  • LIPID MICROSPHERE CONTAINING LIPOPHILIC HEME - PREPARATION AND OXYGEN TRANSPORTATION UNDER PHYSIOLOGICAL CONDITIONS

    E TSUCHIDA, H NISHIDE, T KOMATSU, K YAMAMOTO, E MATSUBUCHI, K KOBAYASHI

    BIOCHIMICA ET BIOPHYSICA ACTA   1108 ( 2 ) 253 - 256  1992.07  [Refereed]

     View Summary

    Lipophilic heme (1-laurylimidazole-ligated 5,10,15,20-tetrakis(alpha,alpha,alpha,alpha-omicron-pivalamidophenyl)porphinatoiron(II) complex) is solubilized in lipid (triglyceride) at high concentrations and emulsified with a phospholipid in physiological salt solution, giving a deeply red-colored suspension of lipid microspheres (approx. 250 nm in diameter). The heme forms an oxygen adduct in a similar manner as oxyhemoglobin and the lipid microspheres take up and release oxygen reversibly at 37-degrees-C in the aqueous medium. The oxygen-transporting ability is comparable with that of the red blood cell. Intravenous injection of thc heme/lipid microsphere solution to rabbits demonstrates that it transports oxygen even in vivo and that it is cleared from the blood stream with a half-life time of approx. 1 h.

  • SYNTHESIS OF POLY(ARYLENE SULFIDE)S BY CATIONIC OXIDATIVE POLYMERIZATION OF DIARYL DISULFIDES

    K YAMAMOTO, M JIKEI, J KATOH, H NISHIDE, E TSUCHIDA

    MACROMOLECULES   25 ( 10 ) 2698 - 2704  1992.05  [Refereed]

     View Summary

    Alkyl-substituted poly(arylene sulfide)s (PASs) are prepared by the oxidative polymerization of diaryl disulfides with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ). The structures of the formed poly(arylene sulfide)s are confirmed by spectroscopic measurements. The linear structure of poly(2-methyl-1,4-phenylene sulfide) is confirmed by comparing its spectroscopic data with those of the polymer prepared from bis(2-methylphenyl) disulfide, bis(3-methylphenyl) disulfide and (4-bromo-2-methylthiophenoxy) copper salt. Bis(2,5-dimethylphenyl) disulfide is easily polymerized to poly(2,5-dimethyl-1,4-phenylene sulfide) with high yield and high melting point in comparison with the other methyl-substituted poly(arylene sulfide)s, due to the symmetry of the polymer structure. The polymerization reaction, with the exception of bis(3,5-dimethylphenyl) disulfide, produces low molecular weight polymers because of the solvent insolubility of PASs and the low reactivity of diaryl disulfides. Soluble poly(2,6-dimethylphenylene sulfide) is isolated by the polymerization of bis(3,5-dimethylphenyl) disulfide as a white powder with ca. 3 x 10(4) weight-average molecular weight.

  • ELECTROACTIVE POLY(ARYLENE SULFIDE) - ELECTRO-OXIDATIVE POLYMERIZATION OF 3,5-DIMETHYLTHIOPHENOL

    K YAMAMOTO, N IWASAKI, H NISHIDE, E TSUCHIDA

    EUROPEAN POLYMER JOURNAL   28 ( 4 ) 341 - 346  1992.04  [Refereed]

     View Summary

    3,5-Dimethylthiophenol and bis(3,5-dimethylphenyl) disulphide have been electro-oxidatively polymerized to poly(2,6-dimethylphenylene sulphide) under mild conditions. The polymer film formed on the electrode has a semi-conductivity of 10(-9) S/cm and electrochemical response. Its redox potential at 1.3 V corresponds to a doping-dedoping reaction.

  • EFFECT OF ULTRASONIC IRRADIATION ON LUMINESCENCE PROPERTIES OF LANTHANIDE POLYELECTROLYTE COMPLEXES

    J KIDO, Y OKAMOTO, N YOSHIOKA, H NISHIDE, E TSUCHIDA

    POLYMER   33 ( 11 ) 2273 - 2276  1992  [Refereed]

     View Summary

    Luminescence properties of Tb3+ - or Eu3+ -polycarboxylate complexes in aqueous solution were investigated. The excitation bands near 300 nm for terbium- or europium-polyacrylate solutions were drastically enhanced by the addition of hydroxyl-radical generating reagents as well as ultrasonic irradiation. These spectral changes were attributed to the energy transfer from chromophore molecules found by the hydroxyl radicals generated in both systems.

  • POLY[(3,5-DI-TERT-BUTYL-4-HYDROXYPHENYL)ACETYLENE] AND ITS POLYRADICAL DERIVATIVE

    H NISHIDE, N YOSHIOKA, K INAGAKI, T KAKU, E TSUCHIDA

    MACROMOLECULES   25 ( 2 ) 569 - 575  1992.01  [Refereed]

     View Summary

    (3,5-Di-tert-butyl-4-hydroxyphenyl)acetylene (8) was synthesized and polymerized with WCl6 and MoCl5, giving a novel and solvent-soluble conjugated polymer, poly[(3,5-di-tert-butyl-4-hydroxyphenyl)-acetylene] (3). Visible absorption of the polymer indicated a fairly long pi-conjugated system along the main chain. The polymer yielded its polyanion 10 and polyradical derivative 4 after the treatment of its solution with an alkali and oxidizing reagent, respectively. The polyradical 4 was surprisingly stable, and spin concentration was increased up to 2.3 x 10(22) spins/molar (hydroxyphenyl)acetylene residue. ESR spectra of the polyradical 4 in solution suggested that the formed upaired electrons were delocalized along the polyacetylene main chain. 4 was also very stable even in solid state. Spin-exchange interaction observed in 4 strongly depended on its spin concentration. Antiferromagnetic interaction between the upaired electrons was suggested from the temperature dependency of the ESR signal intensity.

  • POLYMERIZATION AND RADICAL STABILITY IN THE LIGHT-CURED DENTAL COMPOSITE RESINS

    Y FUJIMORI, T KAKU, N YOSHIOKA, H NISHIDE, E TSUCHIDA

    KOBUNSHI RONBUNSHU   49 ( 6 ) 509 - 512  1992  [Refereed]

     View Summary

    The polymerization behavior of acrylic monomers in the light-cured composite resins and the stability of residual radicals were investigated. The monomer conversion and radical concentration were determined by ESR and IR spectroscopies under various conditions. Slow polymerization proceeded even in the dark by residual radicals, which served post curing of the resins. A decrease in monomer consumption was observed at the surface due to an inhibition effect of oxygen on the photoinitiation process.

  • FACILITATED TRANSPORT OF MOLECULAR-OXYGEN IN COBALTPORPHYRIN POLY(1-TRIMETHYLSILYL-1-PROPYNE) MEMBRANE

    H NISHIDE, H KAWAKAMI, Y SASAME, K ISHIWATA, E TSUCHIDA

    JOURNAL OF POLYMER SCIENCE PART A-POLYMER CHEMISTRY   30 ( 1 ) 77 - 82  1992.01  [Refereed]

     View Summary

    The combination membrane of poly(1-trimethylsilyl-1-propyne) with enormously high permeability and poly(vinylimidazole)-bound porphinatocobalt with selective oxygen-binding ability was prepared. Oxygen transport through the membrane was facilitated in terms of oxygen transport via the latter domain as a fixed oxygen-carrier, and this oxygen permeability maintained for a month.

  • Synthesis and magnetic property of polyacetylene bearing マ�-conjugated bis(diphenylene)phenylallyl radical

    Nishide, Hiroyuki, Yoshioka, Naoki, Saitoh, Yukoh, Gotoh, Ritsuko, Miyakawa, Takeshi, Tsuchida, Eishun

    Journal of Macromolecular Science - Pure and Applied Chemistry   A29 ( 9 ) 775 - 786  1992  [Refereed]

  • Oxygen-transport by artificial red cell (lipid-heme) in blood stream

    Komatsu, T, Matsubuchi, E, Nishide, H, Tsuchida, E, Watanabe, M, Kobayashi, K, Ishihara, T

    Japanese Journal of Artificial Organs   21 ( 1 ) 299 - 303  1992  [Refereed]

  • OXYGEN-TRANSPORT AND SOLUTION PROPERTIES OF POLYLIPID HB VESICLES (ARC)

    S TAKEOKA, E HASEGAWA, H NISHIDE, E TSUCHIDA, S SEKIGUCHI

    BIOMATERIALS ARTIFICIAL CELLS AND IMMOBILIZATION BIOTECHNOLOGY   20 ( 2-4 ) 399 - 404  1992  [Refereed]

     View Summary

    Polymerized phospholipid vesicle encapsulating Hb (polylipid/Hb vesicle) was prepared from a mixture of unsaturated phospholipid, cholesterol and unsaturated fatty acid and polymerization by gamma-ray irradiation. The average radius of resulting vesicles was 203 +/- 39 nm and concentrated Hb (30 wt%) was efficiently encapsulated. gamma-Ray polymerization proceeds theoretically at low temperature (4-degrees-C). P50 and oxygen transporting efficiency were adjusted to 40 mmHg and 40%, respectively. Oncotic pressure and solution viscosity can be controlled to the same values as blood.

  • KINETICS OF BINDING OF O-2 AND CO TO DOUBLE-SIDED PORPHYRINATOIRON(II) COMPLEXES

    T KOMATSU, E HASEGAWA, S KUMAMOTO, H NISHIDE, E TSUCHIDA

    JOURNAL OF THE CHEMICAL SOCIETY-DALTON TRANSACTIONS   ( 12 ) 3281 - 3284  1991.12  [Refereed]

     View Summary

    The kinetics of binding of O2 and CO to double-sided porphyrinatoiron(II) complexes having ester pockets on both sides of the porphyrin plane has been studied. The specific environment created by the four ester groups around the central iron(II) ion of 5,10,15,20-tetrakis(2,6-di-tert-butylacetoxyphenyl)-porphyrinatoiron(II) 2 results in binding which is not affected by solvation. The lower binding affinity for CO of 5,10,15,20-tetrakis(2,6-dipivaloyloxyphenyl)porphyrinatoiron(II) 1 compared to that of 5,10,15,20-tetra (o-pivalamidophenyl)porphyrinatoiron(II) is attributed to the unfavourable steric repulsions between the axial imidazole ligand and the pivaloyloxy groups, and is reflected in decreased association and increased dissociation rates. On the other hand, axial base ligation to 2 is not inhibited by the tert-butylacetoxy groups. Therefore, the lower binding affinity for O2 exhibited by 2 compared to that of an amide fenced porphyrin complex is ascribed to the loss of local polarity in the cavity. The less-polar ester groups of the double-sided porphyrinatoiron complex result in an increased rate of dissociation of O2. The activation energy for gaseous ligand association to complex 2 was determined.

  • METAL-LIGAND BONDING PROPERTIES OF DOUBLE-SIDED PORPHYRIN COMPLEXES - INFLUENCE OF BULKY ESTER GROUPS

    E TSUCHIDA, T KOMATSU, T NAKATA, E HASEGAWA, H NISHIDE, H INOUE

    JOURNAL OF THE CHEMICAL SOCIETY-DALTON TRANSACTIONS   ( 12 ) 3285 - 3289  1991.12  [Refereed]

     View Summary

    Metal-ligand bonding properties of double-sided porphyrinato-iron(II) and -cobalt(II) complexes have been characterized by ESR, IR, and Mossbauer spectroscopy. The smaller A(N) value for a 1-methylimidazole (mim) adduct of 5,10,15,20-tetra(2,6-dipivaloyloxyphenyl)porphyrinatocobalt(II) compared to that of 5,10,15,20-tetra(2,6-di-tert-butylacetoxyphenyl)porphyrinatocobalt(II) suggested that the cobalt-imidazole bond is weak. The ESR spectrum of the dioxygenated double-sided series in fluid toluene indicated that an electrostatic interaction between the bound dioxygen and the ester fences was rarely found. The relaxation of steric strain on the rear side of the ring plane for axial imidazole bonding resulted in a lowering of the bound CO and O2 stretching frequencies of iron(II) complexes. This indicates that the pi-back donation from the d-pi orbital of the iron to the pi* orbital of the bound gaseous ligand could be controlled by the strength of the iron-imidazole bonding, which is regulated by the structure of the rear pocket on the macrocycle. The co-ordination structure of various ligands in double-sided porphyrinatoiron complexes is also discussed by means of Mossbauer parameters.

  • EFFECT OF POLYMER MATRIX ON THE OXYGEN DIFFUSION VIA A COBALT PORPHYRIN FIXED IN A MEMBRANE

    H NISHIDE, H KAWAKAMI, T SUZUKI, Y AZECHI, Y SOEJIMA, E TSUCHIDA

    MACROMOLECULES   24 ( 23 ) 6306 - 6309  1991.11  [Refereed]

     View Summary

    Specific and facilitated transport of molecular oxygen through a polymer membrane containing [alpha-mono(o-methacrylamidophenyl)-alpha,alpha,alpha-tris(o-pivalamidophenyl)porphinato]cobalt (CoMPP) complex as a fixed oxygen carrier is analyzed by a modified dual-mode transport theory, and the effect of the polymer matrix on the oxygen diffusion via the fixed carrier is discussed. Oxygen diffusion coefficients for the diffusion from the polymer matrix to the fixed carrier (D(DC)) and for the diffusion from the fixed carrier to the polymer matrix (D(CD)) increase with physical diffusivity through the polymer matrix. In contrast, the oxygen diffusion coefficient for hopping between the fixed carriers (D(CC)) is independent of the polymer matrix species.

  • SELECTIVE SORPTION AND FACILITATED TRANSPORT OF OXYGEN IN PORPHINATOCOBALT-COORDINATED POLYMER MEMBRANES

    H NISHIDE, H KAWAKAMI, S TODA, E TSUCHIDA, Y KAMIYA

    MACROMOLECULES   24 ( 21 ) 5851 - 5855  1991.10  [Refereed]

     View Summary

    Selective sorption and permeation of molecular oxygen are described for meso-alpha,alpha,alpha,alpha-tetrakis(o-pivalamidophenyl)porphinatocobalt(II) (CoP) coordinated polymer membranes (Chart I). Oxygen solubility is ca. 70 times augmented in comparison with that of nitrogen by the CoP loading in the membrane. Sorption isotherms of oxygen for the membranes are analyzed with a dual-mode sorption model to give C(c)' and K. C(c)' (the saturated amount of oxygen reversibly bound to the CoP sorption site) is independent of temperature and increases with the loaded CoP amount into the membrane. K (the oxygen-affinity constant of CoP) agrees with that determined spectroscopically by monitoring the CoP moiety in the membrane. Oxygen permeation through the membrane is facilitated, and the permeability is in accordance with a dual-mode transport model. Substituting the sorption parameters, C(c)' and K, in the model yields diffusion constants of oxygen in the membranes.

  • ACID EFFECT ON OXIDATIVE POLYMERIZATION OF DIPHENYL DISULFIDE WITH DDQ

    K YAMAMOTO, M JIKEI, K OI, H NISHIDE, E TSUCHIDA

    JOURNAL OF POLYMER SCIENCE PART A-POLYMER CHEMISTRY   29 ( 9 ) 1359 - 1363  1991.08  [Refereed]

  • COORDINATION AND ADSORPTION OF ACETYLENE IN THE POLY[(VINYLCYCLOPENTADIENYL)MANGANESE] MEMBRANE

    H KAWAKAMI, K TSUDA, H NISHIDE, E TSUCHIDA

    MACROMOLECULES   24 ( 11 ) 3310 - 3313  1991.05  [Refereed]

     View Summary

    A copolymer of (vinylcyclopentadienyl)dicarbonylmanganese (CpMn) an octyl methacrylate forms its acetylene-coordinated complex reversibly and stably in the solvent-free membrane state. Kinetic and equilibrium constants of the acetylene coordination to the CpMn residue in the copolymer membrane are determined spectroscopically in situ. The acetylene coordination parameters are much smaller than those of the corresponding nitrogen coordination. Acetylene transport for the membrane is expected to be selectively augmented due to the coordination of acetylene to the fixed CpMn. However, acetylene transport behavior is in accordance with total immobilization of acetylene on the CpMn residue in the acetylene permeation through the membrane.

  • ONE-POT SYNTHESIS OF POLY(THIOARYLENE)S - PREDOMINANT SULFIDE BOND FORMATION THROUGH OXIDATIVE AND ELECTROPHILIC REACTION

    K YAMAMOTO, M JIKEI, Y MURAKAMI, H NISHIDE, E TSUCHIDA

    JOURNAL OF THE CHEMICAL SOCIETY-CHEMICAL COMMUNICATIONS   ( 8 ) 596 - 597  1991.04  [Refereed]

     View Summary

    Poly(thioarylene)s are conveniently prepared in high yield at room temperature and atmospheric pressure through oxidative and electrophilic reaction of disulphur dichloride (S2Cl2) and aromatic compounds.

  • SYNTHESIS OF POLYPHENYLENE THIOETHERS THROUGH CATIONIC OXIDATIVE POLYMERIZATION

    E TSUCHIDA, K YAMAMOTO, M JIKEI, E SHOUJI, H NISHIDE

    JOURNAL OF MACROMOLECULAR SCIENCE-CHEMISTRY   A28 ( 11-12 ) 1285 - 1298  1991  [Refereed]

     View Summary

    Polyaromatic sulfides are efficiently and conveniently prepared by cationic oxidative polymerization. Diphenyl disulfides are quantitatively polymerized to yield poly(p-phenylene sulfide)s as white powders whose structure predominately contains 1,4-phenylene sulfide bonds. The disulfides are oxidized to phenylbis(phenylthio) sulfonium cations as active species of the polymerization. Repeating the oxidation and electrophilic reaction of the cation to the p-position of disulfides yields the polymer.

  • SYNTHESIS AND MAGNETIC-PROPERTIES OF CONJUGATED STABLE POLYRADICALS

    H NISHIDE, N YOSHIOKA, T KAKU, T KANEKO, M YAMAZAKI, E TSUCHIDA

    JOURNAL OF MACROMOLECULAR SCIENCE-CHEMISTRY   A28 ( 11-12 ) 1177 - 1187  1991  [Refereed]

     View Summary

    Synthesis and magnetic properties of pi-conjugated stable polyradicals bearing a polyacetylene backbone are described. 2,6-Di-tert-butyl-4-ethynylphenol (8) and 4-ethynylphenylhydrogalvinoxyl (9) are polymerized with W, Mo chloride or Rh complex to yield their polyacetylene derivatives with molecular weight of ca. 10(4), while 2-ethynylphenalenone (10) gives only its oligomer. The polymers are soluble in common solvents and converted to the corresponding conjugated polyradicals via heterogeneous chemical oxidation using PbO2 or alkaline K3Fe(CN)6. The polyradicals with extremely high spin concentration (up to 4.8 x 10(23) spins/monomer mol) are obtained by regulating the oxidative conditions. The polyradicals are quite stable in solution and even in the solid state because of resonance stabilization and/or a steric effect of the substituents. Magnetic interactions between the unpaired spins in the conjugated stable polyradicals are discussed.

  • Liposome-embedded heme - totally synthetic oxygen carrier and its oxygen carrying capacity

    Kobayashi, Koichi, Watanabe, Masazumi, Ishihara, Tsuneo, Nishide, Hiroyuki, Tsuchida, Eisyun

    Biomaterials, Artificial Cells, and Immobilization Biotechnology   19 ( 2 ) 412  1991  [Refereed]

  • Acute hemodynamic and glycolytic metabolic changes of liposome embedded heme (L/H) in the hemorrhagic dog

    Watanabe, Masazumi, Kobayashi, Koichi, Ishihara, Tsuneo, Nishide, Hiroyuki, Tsuchida, Eisyun

    Biomaterials, Artificial Cells, and Immobilization Biotechnology   19 ( 2 ) 502  1991  [Refereed]

  • Synthesis and characterization of artificial red cell (ARC)

    Tsuchida, Eishun, Nishide, Hiroyuki

    Biomaterials, Artificial Cells, and Immobilization Biotechnology   19 ( 2 ) 494  1991  [Refereed]

  • Oxygen-transport and solution property of polylipid/Hb

    Hasegawa, Etsuo, Nishide, Hiroyuki, Tsuchida, Eishun, Sekiguchi, Sadayoshi

    Biomaterials, Artificial Cells, and Immobilization Biotechnology   19 ( 2 ) 392  1991  [Refereed]

  • Liposome-embedded-heme as a totally artificial oxygen carrier

    Kobayashi, Koichi, Watanabe, Masazumi, Ishihara, Tsuneo, Nishide, Hiroyuki, Tsuchida, Eisyun

    ASAIO Transactions   37 ( 3 ) M443 - M444  1991  [Refereed]

  • POLY(PARA-ETHYNYLPHENYL)GALVINOXYL - FORMATION OF A NEW CONJUGATED POLYRADICAL WITH AN EXTRAORDINARILY HIGH-SPIN CONCENTRATION

    H NISHIDE, N YOSHIOKA, T KANEKO, E TSUCHIDA

    MACROMOLECULES   23 ( 20 ) 4487 - 4488  1990.10  [Refereed]

  • SYNTHESIS, CHARACTERIZATION, AND OXYGENATION OF BIS-FENCED PORPHYRINATO IRON(II) AND COBALT(II) COMPLEXES

    E TSUCHIDA, T KOMATSU, E HASEGAWA, H NISHIDE

    JOURNAL OF THE CHEMICAL SOCIETY-DALTON TRANSACTIONS   ( 9 ) 2713 - 2718  1990.09  [Refereed]

  • AMPHIPHILIC PORPHINATOIRONS HAVING STEROID GROUPS AND THEIR OXYGEN-ADDUCT FORMATION IN AN AQUEOUS-MEDIUM

    E TSUCHIDA, T KOMATSU, T BABE, T NAKATA, H NISHIDE, H INOUE

    BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN   63 ( 8 ) 2323 - 2327  1990.08  [Refereed]

  • ENHANCED STABILITY AND FACILITATION IN THE OXYGEN-TRANSPORT THROUGH COBALT PORPHYRIN POLYMER MEMBRANES

    H NISHIDE, H KAWAKAMI, T SUZUKI, Y AZECHI, E TSUCHIDA

    MACROMOLECULES   23 ( 15 ) 3714 - 3716  1990.07  [Refereed]

  • ELECTRICAL CONDUCTIVE AND MAGNETIC-PROPERTIES OF CONJUGATED TETRATHIOLATE NICKEL POLYMERS

    N YOSHIOKA, H NISHIDE, K INAGAKI, E TSUCHIDA

    POLYMER BULLETIN   23 ( 6 ) 631 - 636  1990.06  [Refereed]

  • OXYGEN-PERMSELECTIVITY IN NEW TYPE POLYORGANOSILOXANES WITH CARBOXYL GROUP ON THE SIDE-CHAIN

    M OHYANAGI, H NISHIDE, K SUENAGA, E TSUCHIDA

    POLYMER BULLETIN   23 ( 6 ) 637 - 642  1990.06  [Refereed]

  • POLYMERIZATION OF DIPHENYL DISULFIDE BY THE S-S BOND-CLEAVAGE WITH A LEWIS ACID - A NOVEL PREPARATION ROUTE TO POLY(PARA-PHENYLENE SULFIDE)

    E TSUCHIDA, K YAMAMOTO, H NISHIDE, S YOSHIDA, M JIKEI

    MACROMOLECULES   23 ( 8 ) 2101 - 2106  1990.04  [Refereed]

  • THE PREPARATION OF POLY(DIHYDROXYPHENYLENE) THROUGH THE ELECTRO-OXIDATIVE POLYMERIZATION OF HYDROQUINONE

    K YAMAMOTO, T ASADA, H NISHIDE, E TSUCHIDA

    BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN   63 ( 4 ) 1211 - 1216  1990.04  [Refereed]

  • OXIDATIVE POLYMERIZATION OF DIPHENYL DISULFIDES WITH QUINONES - FORMATION OF ULTRAPURE POLY(P-PHENYLENE SULFIDE)S

    E TSUCHIDA, K YAMAMOTO, M JIKEI, H NISHIDE

    MACROMOLECULES   23 ( 4 ) 930 - 934  1990.02  [Refereed]

  • OXYGENATION OF A NEW BIS-FENCED PORPHYRINATO IRON WITHOUT AMIDE GROUPS - 5,10,15,20-TETRAKIS(2,6-BISPIVALOYLOXYPHENYL)PORPHYRINATOIRON(II)

    T KOMATSU, E HASEGAWA, H NISHIDE, E TSUCHIDA

    JOURNAL OF THE CHEMICAL SOCIETY-CHEMICAL COMMUNICATIONS   ( 1 ) 66 - 68  1990.01  [Refereed]

  • NEW SYNTHESIS OF POLY(PHENYLENESULFIDE)S THROUGH AN ELECTRON-TRANSFER

    E TSUCHIDA, K YAMAMOTO, H NISHIDE

    JOURNAL OF MACROMOLECULAR SCIENCE-CHEMISTRY   A27 ( 9-11 ) 1119 - 1131  1990  [Refereed]

     View Summary

    Poly(p-phenylenesulfide) (PPS) is efficiently and conveniently produced by a cationic and oxidative polymerization. Diphenyldisulfide is polymerized to PPS through one electron transfer at room temperature. The polymer is isolated as a white powder whose 1,4-structure is confirmed by IR. Phenylbis(phenylthio)sulfonium ion acts as an active species which is formed by oxidation of the S-S bond of diphenyldisulfide, and electrophilically substitutes on the phenyl ring. This polymerization is applicable to the polymerization of alkyl-substituted diphenyldisulfides to give PPSs, such as poly(2-methylphenylenesulfide) and poly(3,5-dimethylphenylenesulfide).

  • MAGNETIC-PROPERTIES OF CONJUGATED PHENOXY POLYRADICALS

    H NISHIDE, N YOSHIOKA, E TSUCHIDA

    JOURNAL OF MACROMOLECULAR SCIENCE-CHEMISTRY   A27 ( 9-11 ) 1261 - 1273  1990  [Refereed]

     View Summary

    Formation and magnetic properties of pi-conjugated phenoxy radicals bearing a porphyrin macrocycle or a polyacetylenic backbone are described. Tetrakis(3,5-di-t-butyl-4-hydroxyphenyl)porphinatometals (7-M) [M = Zn(II), VO(II), and Cu(II)] were oxidized to give the corresponding stable monoradical and biradical. Magnetic properties of the radical species depend on the magnetic orbital of the central metal ion. ESR hfs structure reveals that the biradical for 7-Zn and - VO are in the triplet (S = 1) and quartet state (S = 3/2), respectively. Poly(3,5-di-t-butyl-4-hydroxphenylacetylene) (8) and poly(p-ethynylphenylhydrogalvinoxyl) (9) with molecular weights of similar-to 10(4) are characterized. ESR spectra with hyperfine structure for 8 indicate that the phenoxy radicals are conjugated with the polyacetylenic main chain over similar-to 7 monomer units as a "neutral soliton." Formed polyradicals for 8 and 9 are surprisingly stable, even in the solid state, due to resonance stabilization and/or steric effect of the conjugated main chain. An antiferromagnetic interaction is observed for oxidized 8 with a spin concentration above 10 mol%.

  • PREPARATION OF POLY(PHENYLENE SULFIDE)S - POLYMERIZATION OF AROMATIC DISULFIDES WITH LEWIS-ACIDS

    K YAMAMOTO, S YOSHIDA, H NISHIDE, E TSUCHIDA

    BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN   62 ( 11 ) 3655 - 3660  1989.11  [Refereed]

  • NEW SYNTHESIS OF POLY(PHENYLENE SULFIDE)S THROUGH O-2 OXIDATIVE POLYMERIZATION OF DIPHENYL DISULFIDE WITH VO CATALYST

    E TSUCHIDA, K YAMAMOTO, M JIKEI, H NISHIDE

    MACROMOLECULES   22 ( 10 ) 4138 - 4140  1989.10  [Refereed]

  • REVERSIBLE COORDINATION AND FACILITATED TRANSPORT OF MOLECULAR NITROGEN IN POLY((VINYLCYCLOPENTADIENYL)MANGANESE) MEMBRANE

    H NISHIDE, H KAWAKAMI, Y KURIMURA, E TSUCHIDA

    JOURNAL OF THE AMERICAN CHEMICAL SOCIETY   111 ( 18 ) 7175 - 7179  1989.08  [Refereed]

  • POLYMERIZED LIPOSOME LIPID-HEME AS AN OXYGEN TRANSPORTER UNDER PHYSIOLOGICAL CONDITIONS

    E TSUCHIDA, H NISHIDE, M YUASA, E HASEGAWA, K ESHIMA, Y MATSUSHITA

    MACROMOLECULES   22 ( 5 ) 2103 - 2107  1989.05  [Refereed]

  • OXYGEN-PERMEATION IN SILICONE-BOUND COBALTPORPHYRIN MEMBRANE

    H NISHIDE, M OHYANAGI, K SUENAGA, E TSUCHIDA

    JOURNAL OF POLYMER SCIENCE PART A-POLYMER CHEMISTRY   27 ( 4 ) 1439 - 1443  1989.03  [Refereed]

  • Facilitated transport of nitrogen and acetylene in poly(vinylcyclopentadienylmanganese) membrane

    Nishide, H, Kawakami, H, Tsuchida, E

    Polymeric Materials Science and Engineering, Proceedings of the ACS Division of Polymeric Materials Science and Engineering   61   492 - 496  1989  [Refereed]

  • SYNTHESIS OF POLYMERIZABLE AND AMPHIPHILIC (PORPHINATO)IRONS AND THEIR COPOLYMERS WITH POLYMERIZABLE PHOSPHOLIPID

    E TSUCHIDA, H NISHIDE, M YUASA, T BABE, M FUKUZUMI

    MACROMOLECULES   22 ( 1 ) 66 - 72  1989.01  [Refereed]

  • FACILITATED OXYGEN-TRANSPORT IN POLY(ALKYLMETHACRYLATE-CO-VINYLIMIDAZOLE)-COBALTPORPHYRIN MEMBRANES

    H NISHIDE, K SUENAGA, K MURATA, H KAWAKAMI, E TSUCHIDA

    KOBUNSHI RONBUNSHU   46 ( 6 ) 375 - 379  1989  [Refereed]

  • COORDINATION STRUCTURE AND MAGNETIC PROPERTY OF POLY(PYRIDILENEMETHYLIDENENITRILOIRON)S

    H NISHIDE, N YOSHIOKA, E TSUCHIDA, H INOUE

    JOURNAL OF POLYMER SCIENCE PART A-POLYMER CHEMISTRY   27 ( 2 ) 497 - 505  1989.01  [Refereed]

  • In vivo oxygen-transporting ability of artificial red blood cell (lipid-heme)

    Nishide, H, Yamamoto, K, Fukuzumi, M, Tsuchida, E, Kobayashi, K, Ishihara, T

    Japanese Journal of Artificial Organs   18 ( 1 ) 373 - 375  1989  [Refereed]

  • OXYGEN DIFFUSION VIA COBALT PORPHYRIN COMPLEXES FIXED IN A POLYMER MATRIX

    E TSUCHIDA, H NISHIDE, M OHYANAGI, O OKADA

    JOURNAL OF PHYSICAL CHEMISTRY   92 ( 22 ) 6461 - 6464  1988.11  [Refereed]

  • POLY[(3,5-DI-TERT-BUTYL-4-HYDROXYPHENYL)ACETYLENE] - FORMATION OF A CONJUGATED STABLE POLYRADICAL

    H NISHIDE, N YOSHIOKA, K INAGAKI, E TSUCHIDA

    MACROMOLECULES   21 ( 10 ) 3119 - 3120  1988.10  [Refereed]

  • OXYGEN BINDING AND TRANSPORT IN THE MEMBRANE OF POLY[[TETRAKIS(METHACRYLAMIDOPHENYL)PORPHINATO]COBALT-CO-HEXYL METHACRYLATE]

    H NISHIDE, M OHYANAGI, O OKADA, E TSUCHIDA

    MACROMOLECULES   21 ( 10 ) 2910 - 2913  1988.10  [Refereed]

  • ELECTRO-OXIDATIVE POLYMERIZATION OF P-DIALKOXYBENZENES AND ITS MECHANISM

    K YAMAMOTO, T ASADA, H NISHIDE, E TSUCHIDA

    POLYMER BULLETIN   19 ( 6 ) 533 - 538  1988.06  [Refereed]

  • PREPARATION AND OXIDATIVE POLYMERIZATION OF 2-FLUORO-6(3-METHYL-2-BUTENYL)PHENOL

    SH HYUN, H NISHIDE, E TSUCHIDA, S YAMADA

    POLYMER BULLETIN   19 ( 6 ) 527 - 532  1988.06  [Refereed]

  • EFFECT OF POLYMER MATRIX AND METAL SPECIES ON FACILITATED OXYGEN-TRANSPORT IN METALLOPORPHYRIN (OXYGEN CARRIER) FIXED MEMBRANES

    M OHYANAGI, H NISHIDE, K SUENAGA, E TSUCHIDA

    MACROMOLECULES   21 ( 6 ) 1590 - 1594  1988.06  [Refereed]

  • ORIENTED FIXATION OF SYNTHETIC HEME COMPLEXES IN PHOSPHOLIPID-BILAYER MEMBRANES - ELECTROOPTICAL MEASUREMENT

    M YUASA, H NISHIDE, E TSUCHIDA, A YAMAGISHI

    JOURNAL OF PHYSICAL CHEMISTRY   92 ( 10 ) 2987 - 2990  1988.05  [Refereed]

  • PREPARATION OF POLY(PARA-PHENYLENE) BY ELECTROOXIDATIVE POLYMERIZATION IN ACIDIC MEDIA

    K YAMAMOTO, T ASADA, H NISHIDE, E TSUCHIDA

    BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN   61 ( 5 ) 1731 - 1734  1988.05  [Refereed]

  • REVERSIBLE COORDINATION OF MOLECULAR NITROGEN TO POLYMERIC BENZENECARBONYLCHROMIUM COMPLEXES

    H NISHIDE, H KAWAKAMI, E TSUCHIDA, Y KURIMURA

    JOURNAL OF MACROMOLECULAR SCIENCE-CHEMISTRY   A25 ( 10-11 ) 1339 - 1348  1988  [Refereed]

  • FACILITATED TRANSPORT OF MOLECULAR-OXYGEN IN MEMBRANES OF MACROMOLECULAR COBALT PORPHYRIN COMPLEX - MODIFICATION OF DUAL-MODE TRANSPORT MODEL

    E TSUCHIDA, H NISHIDE, M OHYANAGI

    JOURNAL OF MACROMOLECULAR SCIENCE-CHEMISTRY   A25 ( 10-11 ) 1327 - 1338  1988  [Refereed]

  • INTERACTION OF OXYGEN CARRYING MICROPARTICLES WITH BLOOD COMPONENTS AND CLEARANCE FROM BLOOD STREAM

    E HASEGAWA, K ESHIMA, Y MATSUSHITA, H OHNO, H NISHIDE, E TSUCHIDA

    BIOMATERIALS ARTIFICIAL CELLS AND ARTIFICIAL ORGANS   16 ( 1-3 ) 673 - 674  1988  [Refereed]

  • OXYGEN TRANSPORTING ABILITY OF SYNTHETIC HEMES EMBEDDED IN LIPOSOMES

    H NISHIDE, E TSUCHIDA

    BIOMATERIALS ARTIFICIAL CELLS AND ARTIFICIAL ORGANS   16 ( 1-3 ) 633 - 634  1988  [Refereed]

  • LIPOSOME HEME AS A TOTALLY SYNTHETIC OXYGEN CARRIER

    E TSUCHIDA, H NISHIDE, H OHNO

    BIOMATERIALS ARTIFICIAL CELLS AND ARTIFICIAL ORGANS   16 ( 1-3 ) 313 - 319  1988  [Refereed]

  • OXYGEN-BINDING AND CARBON MONOXIDE-BINDING TO A LIPOPHILIC DIPORPHYRINATOCOPPERIRON COMPLEX SOLUBILIZED IN AN AQUEOUS-MEDIUM WITH A MICELLE

    H NISHIDE, Y HASHIMOTO, H MAEDA, E TSUCHIDA

    JOURNAL OF THE CHEMICAL SOCIETY-DALTON TRANSACTIONS   ( 12 ) 2963 - 2967  1987.12  [Refereed]

  • PREPARATION AND OXIDATIVE POLYMERIZATION OF 2-METHYL-6-GERANYLPHENOL

    SH HYUN, H NISHIDE, E TSUCHIDA, S YAMADA

    POLYMER BULLETIN   18 ( 4 ) 283 - 286  1987.10  [Refereed]

  • DYNAMICS OF OXYGEN BINDING TO MODIFIED IRON(II) PORPHYRIN COMPLEXES EMBEDDED IN THE BILAYER OF PHOSPHOLIPID LIPOSOME

    M YUASA, H NISHIDE, E TSUCHIDA

    JOURNAL OF THE CHEMICAL SOCIETY-DALTON TRANSACTIONS   ( 10 ) 2493 - 2495  1987.10  [Refereed]

  • IRON LIGAND BONDING PROPERTIES OF SYNTHETIC IRON PROPHYRIN COMPLEXES WITH OXYGEN TRANSPORTING ABILITY IN AQUEOUS-MEDIA

    E TSUCHIDA, H MAEDA, M YUASA, H NISHIDE, H INOUE, T SHIRAI

    JOURNAL OF THE CHEMICAL SOCIETY-DALTON TRANSACTIONS   ( 10 ) 2455 - 2458  1987.10  [Refereed]

  • ELECTROOXIDATIVE POLYMERIZATION OF THIOPHENOL TO YIELD POLY(P-PHENYLENE SULFIDE)

    E TSUCHIDA, H NISHIDE, K YAMAMOTO, S YOSHIDA

    MACROMOLECULES   20 ( 9 ) 2315 - 2316  1987.09  [Refereed]

  • FACILITATED TRANSPORT OF MOLECULAR-OXYGEN IN THE MEMBRANES OF POLYMER-COORDINATED COBALT SCHIFF-BASE COMPLEXES

    E TSUCHIDA, H NISHIDE, M OHYANAGI, H KAWAKAMI

    MACROMOLECULES   20 ( 8 ) 1907 - 1912  1987.08  [Refereed]

  • POLY(1-VINYL-2-PYRROLIDONE)-BOUND AND DEXTRAN-BOUND PROTOHEME MONO[N-[3-(IMIDAZOL-1-YL)PROPYL]AMIDE] AND MONO[N-[5-(2-METHYLIMIDAZOL-1-YL)PENTYL]AMIDE] AND THEIR REVERSIBLE OXYGEN BINDING IN AN AQUEOUS-MEDIUM

    H NISHIDE, M YUASA, E HASEGAWA, E TSUCHIDA

    MACROMOLECULES   20 ( 8 ) 1913 - 1917  1987.08  [Refereed]

  • POLY(PARA-PHENYLENE SULFIDE)-YIELDING POLYMERIZATION OF DIPHENYL DISULFIDE BY S-S BOND-CLEAVAGE WITH A LEWIS ACID

    E TSUCHIDA, K YAMAMOTO, H NISHIDE, S YOSHIDA

    MACROMOLECULES   20 ( 8 ) 2030 - 2031  1987.08  [Refereed]

  • REVERSE BOHR EFFECT ON THE OXYGEN-BINDING AFFINITY OF HEME EMBEDDED IN A BILAYER OF LIPOSOME AS A HEMOGLOBIN MODEL - PH-INDUCED OXYGEN-UPTAKE AND EVOLUTION BY AQUEOUS SYNTHETIC LIPID-HEME SOLUTION

    M YUASA, Y TANI, H NISHIDE, E TSUCHIDA

    JOURNAL OF THE CHEMICAL SOCIETY-DALTON TRANSACTIONS   ( 8 ) 1917 - 1920  1987.08  [Refereed]

  • STABILIZATION EFFECT OF TOCOPHEROL AND CATALASE ON THE LIFETIME OF LIPOSOME-EMBEDDED HEME AS AN OXYGEN CARRIER

    M YUASA, Y TANI, H NISHIDE, E TSUCHIDA

    BIOCHIMICA ET BIOPHYSICA ACTA   900 ( 1 ) 160 - 162  1987.06  [Refereed]

  • ELECTROCHEMICAL RESPONSE OF ELECTRODES COATED WITH LYSINE STYRENE BLOCK COPOLYMERS WITH MICROPHASE-SEPARATED STRUCTURES

    E TSUCHIDA, H NISHIDE, N ISHIMARU, DD MONTGOMERY, FC ANSON

    JOURNAL OF PHYSICAL CHEMISTRY   91 ( 11 ) 2898 - 2902  1987.05  [Refereed]

  • COMPLEXATION OF GADOLINIUM ION WITH POLY(METHACRYLIC ACID)S AND MAGNETIC-PROPERTIES OF THE COMPLEXES

    N YOSHIOKA, H NISHIDE, E TSUCHIDA

    INORGANICA CHIMICA ACTA   128 ( 1 ) 135 - 138  1987.04  [Refereed]

  • DUAL-MODE TRANSPORT OF MOLECULAR-OXYGEN IN A MEMBRANE CONTAINING A COBALT PORPHYRIN COMPLEX AS A FIXED CARRIER

    H NISHIDE, M OHYANAGI, O OKADA, E TSUCHIDA

    MACROMOLECULES   20 ( 2 ) 417 - 422  1987.02  [Refereed]

  • AMPHIPHILIC AND POLYMERIZABLE PORPHYRINS AND THEIR COPOLYMERIZATION WITH PHOSPHOLIPID - ORIENTED FIXATION OF PORPHYRINS IN A BILAYER-MEMBRANE

    H NISHIDE, M YUASA, Y HASHIMOTO, E TSUCHIDA

    MACROMOLECULES   20 ( 2 ) 459 - 461  1987.02  [Refereed]

  • COMPLEXATION CONSTANTS OF LANTHANIDE IONS WITH POLY(METHACRYLIC ACID) AND ITS COPOLYMERS

    H NISHIDE, T IZUSHI, H ARAI, N YOSHIOKA, E TSUCHIDA

    JOURNAL OF MACROMOLECULAR SCIENCE-CHEMISTRY   A24 ( 3-4 ) 343 - 351  1987  [Refereed]

  • Oxygen-binding profile of the iron porphyrin complex embedded in polymerized liposome: Effect of the polymerized liposome on the stability and the oxygen-binding ability of the iron porphyrin complex

    E. Tsuchida, H. Nishide, M. Yuasa

    Journal of Macromolecular Science: Part A - Chemistry   24 ( 3-4 ) 333 - 341  1987  [Refereed]

     View Summary

    5,10,15,2O-Tetra(01,01,01,01-0-(2,' 2'-dimethyl-20'-(2”-trimethylarnmonioethyl) phosphonatoxyeicosanamido)phenyl)porphinatoiron(II) (lipidheme) complex embedded in polymerized liposome was prepared by polymerizing 1-(9-(p-vinylbenzoyl)nonanoyl)-2-O-octadecyl-ruc-glycero- 3-phosphocholine in the presence of lipid-heme under ultraviolet irradiation. The polymerization proceeded rapidly, and the reduction of the hemin to the heme occurred spontaneously during the polymerization. The lipid-heme complex embedded in the polymerized liposome bound molecular oxygen reversibly under physiological conditions (pH 7, 37ºC) and was chemically, physically, and mechanically stable during storage for a long period and even in a high-speed flow system. The oxygenbinding affinity was not affected by the type of medium due to the effect of the rigid polymerized liposome. © 1987, Taylor &amp
    Francis Group, LLC. All rights reserved.

    DOI

  • SPECTROSCOPIC STUDY OF OXYGEN SORPTION AND DIFFUSION IN A MEMBRANE CONTAINING A COBALT PORPHYRIN COMPLEX

    H NISHIDE, M OHYANAGI, O OKADA, E TSUCHIDA

    POLYMER JOURNAL   19 ( 7 ) 839 - 844  1987  [Refereed]

  • Oxygen transport behavior through the membrane containing a fixed carrier and adhered to a second polymer

    Nishide, H, Ohyanagi, M, Funada, Y, Ikeda, T, Tsuchida, E

    Macromolecules   20 ( 9 ) 2312 - 2313  1987  [Refereed]

  • Reverse Bohr effect by liposome-embedded lipid-heme

    Yuasa, M, Nishide, H, Tsuchida, E

    Journal of Pharmacobio-Dynamics   10 ( 1 ) s - 21  1987  [Refereed]

  • OXYGEN-EXCHANGE REACTION BETWEEN ARTIFICIAL LUNG DEVICE - THE HEME EMBEDDED IN POLYMERIZED LIPO LIPOSOME AS AN ARTIFICIAL OXYGEN CARRIER

    M YUASA, E HASEGAWA, H NISHIDE, E TSUCHIDA

    JOURNAL OF MACROMOLECULAR SCIENCE-CHEMISTRY   A24 ( 6 ) 661 - 668  1987  [Refereed]

  • Clearance and tissue distribution of functionalized polymeric liposomes from the blood stream of rats

    Matsushita, Y.-I, Eshima, K, Shindo, T, Yamamoto, Y, Hasegawa, E, Nishide, H, Tsuchida, E

    BBA - Biomembranes   901 ( 1 ) 166 - 171  1987  [Refereed]

  • OXIDATIVE POLYMERIZATION OF PHENOLS HAVING TRIMETHYLSILYL GROUPS

    SH HYUN, H NISHIDE, E TSUCHIDA

    POLYMER BULLETIN   16 ( 5 ) 395 - 400  1986.11  [Refereed]

  • PH-INDUCED OXYGEN-UPTAKE AND EVOLUTION BY AQUEOUS SYNTHETIC HEME LIPID SOLUTION

    E TSUCHIDA, H NISHIDE, M YUASA

    JOURNAL OF THE CHEMICAL SOCIETY-CHEMICAL COMMUNICATIONS   ( 14 ) 1107 - 1108  1986.07  [Refereed]

  • DISTANCE DEPENDENCE OF ELECTRON-TRANSFER FROM LIPOSOME-EMBEDDED (ALKANEPHOSPHOCHOLINE-PORPHINATO)ZINC

    E TSUCHIDA, M KANEKO, H NISHIDE, M HOSHINO

    JOURNAL OF PHYSICAL CHEMISTRY   90 ( 11 ) 2283 - 2284  1986.05  [Refereed]

  • HIGHLY SELECTIVE TRANSPORT OF MOLECULAR-OXYGEN IN A POLYMER CONTAINING A COBALT PORPHYRIN COMPLEX AS A FIXED CARRIER

    H NISHIDE, M OHYANAGI, O OKADA, E TSUCHIDA

    MACROMOLECULES   19 ( 2 ) 494 - 496  1986.02  [Refereed]

  • PREPARATION OF FLUOROALKYL ACRYLATE-METHYLSTYRENE RANDOM AND GRAFT COPOLYMER MEMBRANES AND THEIR PERMSELECTIVITY FOR WATER-ETHANOL MIXTURE

    H TOYA, M OHGIZAWA, H NISHIDE

    KOBUNSHI RONBUNSHU   43 ( 9 ) 559 - 563  1986  [Refereed]

  • PREPARATION OF THE COPOLYMER OF ACRYLIC-ACID AND ACRYLAMIDE GRAFTED ONTO POLYETHYLENE AND ITS COMPLEXATION WITH SAMARIUM ION

    J KIDO, H AKIBA, H NISHIDE, E TSUCHIDA, H OMICHI, J OKAMOTO

    KOBUNSHI RONBUNSHU   43 ( 1 ) 31 - 35  1986  [Refereed]

  • COOPERATIVE LIGATION OF DIPORPHINATOIRON(II) COMPLEXES WITH CARBON-MONOXIDE - A HEMOGLOBIN MODEL FOR GASEOUS MOLECULE LIGATION

    E TSUCHIDA, SG WANG, M YUASA, H NISHIDE

    JOURNAL OF THE CHEMICAL SOCIETY-CHEMICAL COMMUNICATIONS   ( 2 ) 179 - 180  1986.01  [Refereed]

  • COMPLEXATION OF TERBIUM ION WITH THE COPOLYMER OF ACRYLIC-ACID AND ACRYLAMIDE GRAFTED ONTO POLYETHYLENE

    H AKIBA, H NISHIDE, E TSUCHIDA, H OMICHI, J OKAMOTO

    JOURNAL OF MACROMOLECULAR SCIENCE-CHEMISTRY   A23 ( 9 ) 1125 - 1135  1986  [Refereed]

  • SYNTHESIS OF POLYMERIZABLE GLYCEROPHOSPHOCHOLINES AND THEIR POLYMERIZED VESICLES

    E HASEGAWA, K ESHIMA, YI MATSUSHITA, H NISHIDE, E TSUCHIDA

    POLYMER BULLETIN   14 ( 1 ) 31 - 38  1985  [Refereed]

  • COMPLEXATION OF EUROPIUM ION WITH POLY(METHACRYLIC ACID)S AND FLUORESCENT PROPERTY OF THE COMPLEXES

    H NISHIDE, T IZUSHI, N YOSHIOKA, E TSUCHIDA

    POLYMER BULLETIN   14 ( 5 ) 387 - 392  1985  [Refereed]

  • PREPARATION AND PROPERTY OF POLY(METHACRYLIC ACID) GADOLINIUM COMPLEX

    N YOSHIOKA, T IZUSHI, H NISHIDE, SHINOHARA, I, E TSUCHIDA, T WATANABE, K KON

    KOBUNSHI RONBUNSHU   42 ( 5 ) 301 - 304  1985  [Refereed]

  • LIPOSOME-EMBEDDED HEME WITH AN OXYGEN-BINDING ABILITY UNDER PHYSIOLOGICAL CONDITIONS

    M YUASA, Y TANI, H NISHIDE, E TSUCHIDA

    KOBUNSHI RONBUNSHU   42 ( 10 ) 685 - 688  1985  [Refereed]

  • RATE PARAMETERS FOR OXYGEN AND CARBON-MONOXIDE BINDING TO A LIPOSOME-EMBEDDED HEME UNDER PHYSIOLOGICAL CONDITIONS

    E TSUCHIDA, M YUASA, H NISHIDE

    JOURNAL OF THE CHEMICAL SOCIETY-DALTON TRANSACTIONS   ( 1 ) 65 - 68  1985  [Refereed]

  • PHOSPHOCHOLINE-SUBSTITUTED 5,10,15,20-TETRAPHENYLPORPHYRINATOIRON(II) - OXYGEN CARRIER UNDER PHYSIOLOGICAL CONDITIONS

    E TSUCHIDA, H NISHIDE, M YUASA, E HASEGAWA, Y MATSUSHITA, K ESHIMA

    JOURNAL OF THE CHEMICAL SOCIETY-DALTON TRANSACTIONS   ( 2 ) 275 - 278  1985  [Refereed]

  • OXYGEN-BINDING TO A LIPOPHILIC DIPORPHINATO COPPER IRON COMPLEX IN AN AQUEOUS-MEDIUM

    H NISHIDE, H MAEDA, SG WANG, E TSUCHIDA

    JOURNAL OF THE CHEMICAL SOCIETY-CHEMICAL COMMUNICATIONS   ( 9 ) 573 - 575  1985  [Refereed]

  • Oxygen binding to ホイ-alkylimidazolyl-meso-tetra(ホア,ホア, ホア,ホア-o-pivalamidophenyl)porphinatoiron(II) embedded in a phospholipid bilayer under physiological conditions

    Eshima, K, Yuasa, M, Nishide, H, Tsuchida, E

    Journal of the Chemical Society, Chemical Communications   ( 3 ) 130 - 132  1985  [Refereed]

  • OXYGEN BINDING TO THE IRON-COPPER COFACIAL DIPORPHYRIN DERIVATIVE EMBEDDED IN POLYMER FILM

    E TSUCHIDA, H NISHIDE, M TAKANE, H YOSHIOKA, SG WANG

    JOURNAL OF INORGANIC BIOCHEMISTRY   25 ( 1 ) 43 - 49  1985  [Refereed]

  • SYNTHESIS OF POLY(PHENYLENE OXIDES) BY ELECTROOXIDATIVE POLYMERIZATION OF PHENOLS

    E TSUCHIDA, H NISHIDE, T MAEKAWA

    ACS SYMPOSIUM SERIES   282   175 - 185  1985  [Refereed]

  • SYNTHESIS OF OLIGO (PHENYLENEOXIDE) BY ELECTRO-OXIDATIVE POLYMERIZATION

    E TSUCHIDA, H NISHIDE, T MAEKAWA

    JOURNAL OF MACROMOLECULAR SCIENCE-CHEMISTRY   A21 ( 8-9 ) 1081 - 1096  1984  [Refereed]

  • MOSSBAUER SPECTROSCOPIC STUDY OF POLYMER-BOUND HEME COMPLEXES

    E TSUCHIDA, H NISHIDE, H YOKOYAMA, H INOUE, T SHIRAI

    POLYMER JOURNAL   16 ( 4 ) 325 - 331  1984  [Refereed]

  • REVERSIBLE OXYGEN BINDING BY THE COMPLEX OF POLY(2-METHYL-1-VINYLIMIDAZOLE) AND HEME IN COLD AQUEOUS-MEDIA

    E TSUCHIDA, H NISHIDE, H YOKOYAMA

    JOURNAL OF THE CHEMICAL SOCIETY-DALTON TRANSACTIONS   ( 11 ) 2383 - 2387  1984  [Refereed]

  • Liposomal heme as oxygen carrier under semi-physiological conditions

    Tsuchida, E, Nishide, H, Yuasa, M, Hasegawa, E, Matsushita, Y.-I

    Journal of the Chemical Society, Dalton Transactions   ( 6 ) 1147 - 1151  1984  [Refereed]

  • OXYGEN-BINDING RATE PARAMETERS FOR A LIPOSOME-EMBEDDED HEME UNDER PHYSIOLOGICAL CONDITIONS

    E TSUCHIDA, H NISHIDE, M YUASA

    JOURNAL OF THE CHEMICAL SOCIETY-CHEMICAL COMMUNICATIONS   ( 2 ) 96 - 98  1984  [Refereed]

  • ENZYMATIC REDUCTION OF SYNTHETIC POLYMER-BOUND HEMIN DERIVATIVES - EFFICIENT METHOD TO PREPARE A HEME-OXYGEN ADDUCT IN COOLED AQUEOUS-MEDIUM

    N UOTANI, E HASEGAWA, H NISHIDE, E TSUCHIDA

    JOURNAL OF INORGANIC BIOCHEMISTRY   22 ( 2 ) 85 - 89  1984  [Refereed]

  • COMPLEXATION OF SAMARIUM ION WITH POLY(ACRYLIC ACID) GRAFTED ONTO POLYETHYLENE BY RADIATION-INDUCED METHOD

    T MAEKAWA, H NISHIDE, E TSUCHIDA, H OHMICHI, J OKAMOTO

    JOURNAL OF APPLIED POLYMER SCIENCE   29 ( 12 ) 3795 - 3801  1984  [Refereed]

  • OXYGEN MONOXIDE AND CARBON MONOXIDE-BINDING AFFINITY OF THE LIPOSOMAL HEME UNDER SEMIPHYSIOLOGICAL CONDITIONS

    E TSUCHIDA, H NISHIDE, M YUASA, M SEKINE

    BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN   57 ( 3 ) 776 - 780  1984  [Refereed]

  • SYNTHESIS OF OLIGO (PHENYLENEOXIDE) BY ELECTRO-OXIDATIVE POLYMERIZATION.

    Tsuchida, Eishun, Nishide, Hiroyuki, Maekawa, Toshihiko

    American Chemical Society, Polymer Preprints, Division of Polymer Chemistry   25 ( 1 ) 131 - 132  1984  [Refereed]

  • LIPOSOMAL HEME AS OXYGEN CARRIER UNDER SEMI-PHYSIOLOGICAL CONDITIONS - ORIENTATION STUDY OF HEME EMBEDDED IN A PHOSPHOLIPID-BILAYER BY AN ELECTROOPTICAL METHOD

    E TSUCHIDA, H NISHIDE, M SEKINE, A YAMAGISHI

    BIOCHIMICA ET BIOPHYSICA ACTA   734 ( 2 ) 274 - 278  1983  [Refereed]

  • ELECTRON-TRANSFER BEHAVIOR OF THE METAL-COMPLEXES ATTACHED TO POLYMER MATRICES

    E TSUCHIDA, H NISHIDE

    ACS SYMPOSIUM SERIES   212   49 - 63  1983  [Refereed]

  • OXYGENATION OF THE HEME-COMPLEX BOUND TO POLYMERIC 2-METHYLIMIDAZOLES

    H NISHIDE, M SEKINE, E TSUCHIDA

    POLYMER JOURNAL   14 ( 8 ) 629 - 633  1982  [Refereed]

  • POLYMER-BOUND PROTOHEME-MONO-N-[3-(IMIDAZOL-1-YL)PROPYL]AMIDE AND -MONO-N-[5-(2-METHYLIMIDAZOL-1-YL)PENTYL]AMIDE

    E TSUCHIDA, H NISHIDE, Y SATO

    JOURNAL OF THE CHEMICAL SOCIETY-CHEMICAL COMMUNICATIONS   ( 10 ) 556 - 557  1982  [Refereed]

  • OXIDATIVE CLEAVAGE OF 4-METHYLCATECHOL WITH A CU COMPLEX BOUND TO POLY(STYRENE-CO-4-VINYLPYRIDINE)

    H NISHIDE, T MINAKATA, E TSUCHIDA

    JOURNAL OF MOLECULAR CATALYSIS   15 ( 3 ) 327 - 335  1982  [Refereed]

  • COORDINATION PROPERTY OF POLY(1-VINYL-2-METHYLIMIDAZOLE)-HEME COMPLEXES

    E TSUCHIDA, H NISHIDE, H OHNO

    JOURNAL OF INORGANIC BIOCHEMISTRY   17 ( 4 ) 283 - 291  1982  [Refereed]

  • CHELATING RESIN - PYRIDINE-DERIVATIVES ATTACHED TO POLY(STYRENE) BEADS WITH SPACER GROUP

    H NISHIDE, N SHIMIDZU, E TSUCHIDA

    JOURNAL OF APPLIED POLYMER SCIENCE   27 ( 11 ) 4161 - 4169  1982  [Refereed]

  • COMPLEXATION OF POLY(ACRYLIC ACID)S WITH URANYL-ION

    H NISHIDE, N OKI, E TSUCHIDA

    EUROPEAN POLYMER JOURNAL   18 ( 9 ) 799 - 802  1982  [Refereed]

  • OXYGEN-MONOXIDE AND CARBON-MONOXIDE BINDING KINETIC-PARAMETERS FOR LIPOSOMAL HEME UNDER SEMI-PHYSIOLOGICAL CONDITION

    E TSUCHIDA, H NISHIDE, M SEKINE, M YUASA, T IIZUKA, Y ISHIMURA

    BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS   109 ( 3 ) 858 - 863  1982  [Refereed]

  • RADICAL COPOLYMERIZATION OF PROTO-HEMIN DIMETHYL ESTER

    H NISHIDE, K SHINOHARA, E TSUCHIDA

    JOURNAL OF POLYMER SCIENCE PART A-POLYMER CHEMISTRY   19 ( 5 ) 1109 - 1117  1981  [Refereed]

  • COMPLEXATION OF METAL-ION WITH POLY(1-VINYLIMIDAZOLE) RESIN PREPARED BY RADIATION-INDUCED POLYMERIZATION WITH TEMPLATE METAL-ION

    M KATO, H NISHIDE, E TSUCHIDA, T SASAKI

    JOURNAL OF POLYMER SCIENCE PART A-POLYMER CHEMISTRY   19 ( 7 ) 1803 - 1809  1981  [Refereed]

  • IMMOBILIZATION OF HEME COMPLEX BY RADIATION POLYMERIZATION

    H NISHIDE, M KATO, E TSUCHIDA

    EUROPEAN POLYMER JOURNAL   17 ( 5 ) 579 - 581  1981  [Refereed]

  • OXIDATIVE POLYMERIZATION OF 2,6-DIMETHYLPHENOL CATALYZED BY INSOLUBLE POLYMER-COPPER COMPLEXES

    H NISHIDE, Y SUZUKI, E TSUCHIDA

    EUROPEAN POLYMER JOURNAL   17 ( 5 ) 573 - 577  1981  [Refereed]

  • POLYMER-COPPER CATALYSTS FOR OXIDATIVE POLYMERIZATION OF PHENOL DERIVATIVES.

    Tsuchida, E, Nishide, H

    ACS Symposium Series     147 - 163  1980  [Refereed]

  • Synthesis of polymer catalysts containing vinyl-imidazolehydroxamic acid and their ester hydrolysis catalytic activity

    Nishide, H, Storck, W, Manecke, G

    Journal of molecular catalysis   6 ( 1 ) 23 - 39  1979  [Refereed]

  • POLYMER-Cu CATALYSTS FOR OXIDATIVE POLYMERIZATION OF PHENOL DERIVATIVES.

    Tsuchida, Eishun, Nishide, Hiroyuki

    Am Chem Soc Div Org Coat Plast Chem Prepr   40  1979  [Refereed]

  • Oxygenation of cobalt(II) protoporphyrin IX dimethyl ester bound to copolymer of 4-vinylpyridine and styrene

    Nishide, H, Hata, S, Mihayashi, K, Tsuchida, E

    Biopolymers   17 ( 1 ) 191 - 197  1978  [Refereed]

  • ADSORPTION OF METAL IONS ON CROSSLINKED POLY(4-VINYLPYRIDINE) RESINS PREPARED WITH A METAL ION AS TEMPLATE.

    Nishide, Hiroyuki, Deguchi, Jichio, Tsuchida, Eishun

    J Polym Sci Polym Chem Ed   15 ( 12 ) 3023 - 3029  1977  [Refereed]

  • Dissociation of aggregated ferroheme complexes and protoporphyrin IX by water soluble polymers

    Nishide, H, Mihayashi, K, Tsuchida, E

    Biochimica et Biophysica Acta   498 ( 1 ) 208 - 214  1977  [Refereed]

  • POLYMER-METAL COMPLEXES AND THEIR CATALYTIC ACTIVITY.

    Tsuchida, Eishun, Nishide, Hiroyuki

    Adv Polym Sci   ( 24 ) 1 - 87  1977  [Refereed]

  • SPECTROSCOPIC STUDY ON THE ELEMENTARY REACTIONS OF OXIDATIVE POLYMERIZATION.

    Tsuchida, Eishun, Nishide, Hiroyuki, Nishikawa, Hiroshi

    J Polym Sci Part C, Polym Symp   ( 47 ) 47 - 54  1974  [Refereed]

  • KINETIC DISCUSSION ON THE CATALYSIS OF COPPER-PARTIALLY-QUATERNIZED POLY-(VINYLPYRIDINE) COMPLEXES.

    Tsuchida, Eishun, Nishide, Hiroyuki, Nishiyama, Toshio

    J Polym Sci Part C, Polym Symp   ( 47 ) 35 - 46  1974  [Refereed]

▼display all

Books and Other Publications

  • Advanced Nanomaterials vol. 1 and 2

    K. E. Geckeler, H. Nishide

    Wiley-VCH, Weinheim  2010

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    西出 宏之, 小柳津 研一

    Patent

  • 空気電池

    小柳津 研一, 原田 大輔, 西出 宏之, 崔 源成

    Patent

  • 光電気素子

    5957012

    加藤 文昭, 西出 宏之, 小柳津 研一

    Patent

  • 光電気素子及びその製造方法

    6010549

    西出 宏之, 小柳津 研一, 加藤 文昭, 佐野 直樹

    Patent

  • 光吸収材料及び光電変換素子

    西出 宏之, 小柳津 研一, 加藤 文昭

    Patent

  • 光電気素子

    西出 宏之, 小柳津 研一, 加藤 文昭

    Patent

  • 光電変換素子

    5639510

    西出 宏之, 小柳津 研一, 加藤 文昭

    Patent

  • ジシアノアントラキノンジイミンポリマー、電荷貯蔵材料、電極活物質、電極及び電池

    5700371

    西出 宏之, 小柳津 研一

    Patent

  • 光電気素子、及び光電気素子の製造方法

    5894372

    西出 宏之, 小柳津 研一, 加藤 文昭, 佐野 直樹

    Patent

  • 耐酸化性に優れる外部電極用導電性ペースト用銅粉及び銅ペースト

    西出 宏之, 加藤 文昭

    Patent

  • ラジカルを有する化合物、重合体、およびその重合体を用いた蓄電デバイス

    5625151

    西出 宏之, 小柳津 研一

    Patent

  • 有機太陽電池

    西出 宏之, 須賀 健雄, 伊藤 正泰

    Patent

  • 光電気素子

    5584447

    小柳津 研一, 西出 宏之, 加藤 文昭

    Patent

  • ポリラジカル化合物

    5254167

    西出 宏之, 伊部 武史

    Patent

  • 二次電池

    5443931

    西出 宏之, 伊部 武史

    Patent

  • ポリラジカル化合物の製造方法

    5518416

    西出 宏之, 伊部 武史

    Patent

  • 光電気素子

    5480552

    西出 宏之, 小柳津 研一, 加藤 文昭

    Patent

  • 光電気素子

    5400180

    西出 宏之, 小柳津 研一, 加藤 文昭

    Patent

  • 光電気素子

    5654779

    西出 宏之, 小柳津 研一, 加藤 文昭

    Patent

  • 光吸収材料及び光電変換素子

    5711470

    西出 宏之, 小柳津 研一, 加藤 文昭

    Patent

  • ポリチオフェン又はチオフェン共重合体の溶液又は分散液並びにその製造方法

    5317758

    西出 宏之, 岡安 輝之, 阿部 聡

    Patent

  • 平版印刷版の画線部形成用材料、この画線部形成用材料が使用された平版印刷版、この平版印刷版の画線部形成方法及びこの平版印刷版の書換え方法

    5263518

    西出 宏之, 小柳津 研一

    Patent

  • ピロリン系ニトロキシド重合体およびそれを用いた電池

    5527667

    西出 宏之, 小柳津 研一, 川本 健

    Patent

  • 高分子積層膜

    5221199

    西出 宏之, 岡安 輝之, 阿部 聡

    Patent

  • メモリ素子

    西出 宏之, 小柳津 研一, 米久田 康智, 尾崎 貴則

    Patent

  • キノンポリマー電極、電荷貯蔵材料、及び電池

    西出 宏之, 小柳津 研一, 崔 源成

    Patent

  • 光電気素子

    5204848

    西出 宏之, 小柳津 研一, 加藤 文昭, 高橋 央

    Patent

  • 蓄電材料およびそれを用いた二次電池

    西出 宏之, 小柳津 研一, 小鹿 健一郎

    Patent

  • 導電性含水ゲル

    西出 宏之, 小柳津 研一, 小鹿 健一郎

    Patent

  • 光電変換素子

    5237664

    西出 宏之

    Patent

  • ポリラジカル化合物、電極活物質および電池

    5176130

    西出 宏之, 須賀 健雄

    Patent

  • ポリラジカル化合物および電池

    5176129

    西出 宏之, 須賀 健雄

    Patent

  • ピロリン系ニトロキシド重合体およびそれを用いた電池

    5424402

    西出 宏之, 小柳津 研一

    Patent

  • メモリー素子及びその製造方法

    5007566

    西出 宏之, 倉田 崇, 安部 滋幹, 本田 憲治

    Patent

  • エレクトロクロミックディスプレイ

    4941885

    西出 宏之, 本田 憲治, 神長 隆史

    Patent

  • 二次電池用活物質層及びその形成方法並びに二次電池用活物質層形成用塗布液

    西出 宏之, 須賀 健雄

    Patent

  • ノルボルネン系架橋共重合体及びその製造方法

    4617437

    西出 宏之, 須賀 健雄

    Patent

  • 電極活物質、電池及び重合体

    4955233

    西出 宏之, 藤長 将司

    Patent

  • ポリフェニレンエーテルの製造方法

    4022925

    西出 宏之, 齋藤 敬

    Patent

  • ポリフェニレンエーテルの製造方法

    4042149

    西出 宏之, 齋藤 敬

    Patent

  • 酸素透過高分子薄膜

    西出 宏之, 篠原 浩美

    Patent

  • ラジカル高分子化合物からなる磁性素子

    西出 宏之, 宮坂 誠, 道信 剛志

    Patent

▼display all

Awards

  • ポルフィリン-ALA学会賞

    2015  

  • 日本化学会賞

    2014  

  • 文部科学大臣表彰 (科学技術分野)

    2013  

  • The Chemical Society of Japan (CSJ) Award

    2013  

  • SPSJ Award for Outstanding Achievement in Polymer Science and Technology

    2010  

  • The Award of the Society of Polymer Science

    1990  

▼display all

Research Projects

  • Charge/ Hydrogen -Transport and -Storage through the Exchanging Reactions in Redox Polymers

    Project Year :

    2018.04
    -
    2021.03
     

  • NEDO 高性能・高信頼性太陽光発電の発電コスト低減技術開発

    Project Year :

    2015
    -
    2020
     

  • 全有機固体電池:レドックスポリマー電極と固体電解質の研究

    Project Year :

    2015.11
    -
    2018.03
     

     View Summary

    重金属フリーで環境適合、サステイナブルな次世代蓄電池(二次電池)の電極活物質として期待されるラジカルポリマーでの電荷輸送特性を解明し、全有機電池としての道筋を提示するための基礎研究である。受入研究室で世界的に先駆け展開しているニトロキシド(TEMPO)ラジカルポリマーを対象に、その界面での電荷授受および対イオンの拡散過程を当該研究者が所属機関(端・ウプサラ大)で実施してきた解析法も併用して検討し、電極活物質としての要件を抽出した。また新しい電荷貯蔵サイトの分子設計と高分子化実験も試行した。TEMPOラジカルポリマーを対象に、電荷拡散による約10μS/㎝の導電性を定量的に解析し、電荷の拡散定数10-9cm2/sと対イオンの拡散定数7×10-10cm2/sより後者が微視的には律速であることを示した。またポッピング機構による自己電子交換での再配置エネルギーが約1eVであること、またラジカル部位周りの極性場が支配因子であることをはじめて明らかにした。以上より、距離10μmでの導電、すなわち添加物無い有機ラジカルポリマーでも数μm厚みで電池電極として作動しうる結論を得た。このほか有機電池の構成成分としてのテレフタル酸リチウム、電解質ポリエチレンオキシド誘導体の可能性を探索もした。以上、有機固体電池へのアプローチ法をとりまとめた。翌年度、交付申請を辞退するため、記入しない。翌年度、交付申請を辞退するため、記入しない

  • Aromatic Ketone Polymers for A Hydrogen Career

    Project Year :

    2015.04
    -
    2017.03
     

     View Summary

    We have proposed aromatic ketone polymers as a new class of hydrogen careers and elucidated their hydrogen storage property. The fluorenone polymers were synthesized, and highly efficient hydrogenation of the polymers was examined through the electrolytic reduction and successive protonation with water. Quantitative hydrogen evolution from the hydrogenated polymers was measured by heating in the solution containing catalyst, to characterize the aromatic ketone polymers as a hydrogen career

  • Development of Novel Photo- and Electro-functional Polymers by SOMO Design of Organic Radicals

    Project Year :

    2012.05
    -
    2017.03
     

     View Summary

    We have been focusing on reversible and rapid electron-transfer processes of organic robust radicals and developing “radical polymers” as a new class of functional polymers. The present research described the chemistry of materials for charge-transport and -storage exploiting redox gradient-driven electron self-exchange reactions. The research was broadened by developing highly efficient transporting systems and precisely designing transport properties. The electroactive polymers were explored by pursuing new characteristics along expanding the radical species, besides a SOMO (singly-occupied MO)-π conjugated system. The research provided a breakthrough for organic photovoltaic and rechargeable devices

  • In-situ Formation of Radical/p-Conjugated Polymer Blends for Rapid Charge-Storage

    Project Year :

    2013.04
    -
    2015.03
     

     View Summary

    We proposed the combination of "charge-storage" based on redox reaction of durable organic radicals (SOMO) and "charge-conduction" through π-conjugation (HOMO-LUMO) to yield new energy-storage materials. Especially, we focused on vapor-phase oxidative polymerization (VPP) as a facile method for in-situ preparation of π-conjugated polymers. Prior to VPP process, chemical oxidants such as Fe(OTs)3 were mixed with nitroxide radical polymers to convert the corresponding oxoammonium salts, to suppress the radical inhibition of oxidative polymerization of EDOT. The obtained p- and n-type radical polymers/PEDOT blend was utilized as cathode- and anode-active materials, respectively, leading to the metal-free, wearable rechargeable battery. In-situ VPP method using oxidant vapors such as iodine also produced organic donor layer toward organic solar cells

  • Development of n-type redox polymers and their application to organic anode-active materials

    Project Year :

    2009.04
    -
    2013.03
     

     View Summary

    Polyimides were found to exhibit excellent redox capability per repeating unit when they were made into a carbon nanocomposite layer at a molecular level. The reversible redox reaction obtained by placing the polyimide/carbon composite layer on a current collector was applied to the charge-storage process of anodes in organic batteries. A variety of polymers with an ultimate density of organic redox-active sites were synthesized, and their basic properties as the anode-active materials were determined. Enhanced charge transfer process accomplished by the precise control of mass-transfer process led to rapid and large-capacity charge storage with the polymers. A design strategy of electrode-active materials with excellent ionic migration processes was proposed, which allowed significant reduction of the amount of electrolytes in batteries

  • Grant-in-Aid for Scientific Research (S)

    Project Year :

    2007
    -
    2011
     

  • ナノ構造配列を基盤とする分子ナノ工学の構築とマイクロシステムへの展開

    科学研究費助成事業(早稲田大学)  科学研究費助成事業(COE形成基礎研究費)

    Project Year :

    2001
    -
    2005
     

     View Summary

    拠点の整備状況
    本拠点を中核として、ナノテクファウンドリ、21世紀COEに係る2拠点などを統合した「ナノ理工学研究機構」の設立(平成15年12月)に加え、平成16年度には、文科省科学技術振興調整費「戦略的研究拠点形成プログラム」にかかわる「早稲田大学先端科学・健康医療融合研究機構」が発足、本拠点との連携によって、ナノバイオテクノロジー研究推進体制が強化された。
    研究成果
    各個研究に加え、チーム内外の共同研究を督励し、13件の研究を推進。また、プロトタイプ(PT)研究として、平成15年度に5件、16年度に更に2件の研究課題を選定。以下、グループ(G)毎に主要な研究成果をまとめる。
    <ナノ物性G>
    大泊研
    ・ドーパント原子の規則配列をもつ新規半導体を創製、特性揺らぎ減少を確認。本成果はNature誌に掲載。
    ・有機シラン単分子膜をレジストとする電子線リソグラフィを開発、分解能10nmの高精細パターン形成に成功。
    ・スライドガラスにナノ加工を施し、従来不可能な高濃度蛍光色素条件下での蛋白質間相互作用の1分子観察技術を実現。(共同-船津研)
    ・Si酸化過程を原子スケールで再現する大規模シミュレータの開発(PT研究)により、従来理論を覆す新理論の発見、酸化種拡散に関する理論予測の放射光X線回折実験による実証、に成功。(共同-阪大グループ)
    ・ナノ改質の原子的素過程の解明のために、独自開発した「イオン銃/超高真空高温STM複合装置」を用い、イオン照射誘起欠陥の動態、スパッタリング素過程のリアルタイム観察に成功。
    川原田研
    ・ボロン(アクセプタ)を大量にドープした気相合成ダイヤモンドでの超伝導を発現。本成果はNature誌に掲載。
    ・100nmゲートダイヤモンドバイオセンサ開発に成功、MEMS技術を併用して、zept(10^<-19>〜10^<-21>)molの高感度検出を可能とした。
    ・表面修飾ダイヤモンドトランジスタ試作により、50GHzの動作周波数確認。1GHzでの出力密度2.1W/mmを実現。
    ・表面修飾ダイヤモンドによりDNAの局所固定およびDNAアクティブセンサ開発に成功。(共同-大泊研)
    星野研
    ・蛋白質とナノ構造基板間の相互作用を理論的に計算し、基板の疎/親水性による水溶性蛋白質の小さな選択吸着性を発見、ナノ構造配列による蛋白質の結晶成長装置を試作。(共同-大泊研)
    <ケミカルナノプロセスG>
    逢坂研
    ・新電析浴により実用的に十分な腐食耐性を有する軟磁性CoFe薄膜の作製に成功。記録媒体薄膜の作製では、磁壁やラフネスの制御により低雑音化を実現。(PT研究)
    ・超小型燃料電池の試作セルにて、0.81mW/cm^2の出力密度と安定動作を実現。(共同-庄子研)
    黒田研
    ・メソポーラス金属層の形成に成功。それを応用した新規デバイスの開発を開始。(共同-逢坂研)
    ・センチメートルスケールで単結晶様の細孔構造の配向性3次元メソポーラスシリカ薄膜作製に成功。
    西出研
    ・高分子配列固定の研究において、電気化学的に有機ラジカル公文氏のスピン密度を可逆変化させることに成功。(共同-大泊研)
    ・Coポルフィリンに替る安価な材料としてCoフタロシアニンにおいて酸素促進輸送を確認。Coポルフィリンを多孔ガラスに担持させることによりマスクとしての使用に必要な高流量を達成。(PT研究)
    <バイオマイクロシステムG>
    松本研
    ・生体関連物質の超高感度検出のために新規希土類蛍光錯体の開発、DNA分析への応用、白金ナノワイヤ合成のための多核錯体の合成を行った。
    ・MEMS技術を活用した細胞破砕の基礎実験を行い、破砕時間200msを確認。(共同-庄子研)
    庄子研
    ・バイオマイクロシステム構築のため、インジェクタ、フィルタ、バルブなどのマイクロ流体素子の試作、評価を行った。
    ・燃料電池および高感度酵素検出システムのマイクロ化。(共同-逢坂研)
    船津研
    ・細胞内情報伝達の可視化のために、イントロンとエキソンを異なる蛍光色素で標識し、スプライシングを1分子レベルで検出する技術を開発。
    ・ガラス基板へのナノ開口配列形成により1分子レベルの生体分子間相互作用の検出技術を開発。(共同-大泊研、庄子研)
    <ナノ理工学基礎G>
    堀越研
    ・希薄磁性半導体GaMnAsにおいて世界最高のキュリー温度(250K)を達成。
    ・シングルイオン注入法による半導体中強磁性体クラスタ配列形成(共同-大泊研)、ペロブスカイト系強磁性体を用いる極微小不揮発性メモリなそ、半導体内スピンに関する研究を開始。
    大場研
    ・ナノ実験系の基礎理論からの指導原理の提示を目的に、ナノ構造体と環境系との相互作用のモデル化、半導体中の励起子のトンネル現象(共同-堀越研)、半導体中の不純物原子配列が固体物性に及ぼす効果(共同-大泊研)の評価、などを進めた。

  • 環境触媒プロセスの開発

    文部科学省 

    Project Year :

    2000
    -
    2004
     

  • 人工臓器素材開発

    文部科学省 

    Project Year :

    1996
    -
    2000
     

  • Synthesis of Non-Kekule Type π-Conjugated Polymers and Co-operative Multiple-Spin Alignment

    Project Year :

    1997
    -
    1999
     

     View Summary

    Objectives of this research are the synthesis of π-conjugated polymers bearing pendant radical groups on every monomer unit, which are substituted on the polymer backbone to satisfy a π-conjugated but non-Kelule structure, and the study on strong and through-bond ferromagnetic exchange interaction between and alignment of the multiple spins of the pendant radicals.
    (1) Bromostyrene dirivatives were polycondensated with a Pd-phosphine catalyst to yield π-conjugated star-shaped or hyperbranched poly (4-phenoxyl-1, 2-phenylenevinylene) s. SQUID and pulsed ESR measurements revealed the spin-alignment, e. g., with S = 10/2.
    (2) Linear, acyclic, and cyclic poly (phenoxy-phenyleneethynylene) s were synthesized by the polycondensation of the iodostyrene derivatives with a Pd/Cu catalyst. The cyclic and conjugated one was an effective spin pathway.
    (3) Diphenylaminium cation radical was introduced as a spin source to poly (4-substituted 1, 2-phenylenevinylene) to realize both a sufficient ferromagnetic interaction and chemical stability even at room temperature. Stability of the multiplet ground state was significantly large to first give a highspin and durable organic polymer.

  • 新高分子・ナノ組織体

    科学研究費助成事業(九州大学)  科学研究費助成事業(重点領域研究)

    Project Year :

    1996
    -
    1999
     

     View Summary

    1)特定領域研究「新高分子・ナノ組織体」の3年間にわたる研究成果を、各班および研究分野ごとにまとめ、その内容を検討した。個々の総括班員の間で打ち合わせを行うと共に、全班員による検討会(総括班会議)を2回開催し、総括した。
    2)これらの検討会により、研究内容についてチェック・アンド・レビューを実施し、プロジェクト研究として総括し、特定領域研究「新高分子・ナノ組織体」の研究成果を730ページの研究成果報告書としてまとめた。また、本研究成果を(社)高分子学会発行のPolymer Journal誌に"New Polymers and Their Nano-Organized Systems"特集号としてまとめ、第31巻11-2号として平成11年11月15日に発行した。さらに、別予算であるが、300余頁の英文学術書"Precision Polymers and Nano-Organized Systems"を講談社により平成12年2月に発行する。
    3)上記の成果とりまとめの結果に基づき、特定領域研究「新高分子・ナノ組織体」の成果を公開するシンポジウムを、第7回公開シンポジウムとして平成11年10月25日に東京の日本化学会化学会館ホールで開催し、外国人2人を含む10件の講演を行った。また、別予算であるが「大学と科学」公開シンポジウムとして「分子がつくるナノの不思議」と題した公開シンポジウムを、平成11年11月29-30日に大阪の千里ライフサイエンスセンターで開催した。

  • 集積型ポルフィリン高分子錯体による酸素促進輸送

    科学研究費助成事業(早稲田大学)  科学研究費助成事業(特定領域研究(A))

    Project Year :

    1998
     
     
     

     View Summary

    高分子配位子鎖上に、酸素分子結合の動的および平衡挙動の異なる一連のポルフィリン錯体が週続して結合した「集積型」のポルフィリン高分子錯体を構築、これら錯体から擁膜を作成、膜内に選択的かつ多量に取り込まれた酸素分子が、ポルフィリン錯体の集積場内を結合脱着を繰り返しながら拡散する動的過程を高速分光および透過測定から同時解析し、酸素が選択的に透する促進輸送現象として実証することを目的した。
    (1) 1-ビニルイミダゾール、4(5)-ビニルイミダゾール、2-ビニルピリジン、4-ビニルピリジン、4-イミダゾリルメチルスチレンとオクチルメタクリレートとの共重合体とピケットフェンスコバルトポルフィリン(COP)の集積錯体から柔軟な赤色透明膜を得た。酸素の結合平衡定数は芳香族アミンの塩基性とともに増加、特に分子内での水素結合ある(4)5-ビニルイミダゾール共重合体は高い酸素親和性を示した。フッ化アルキルメタクリレートとの共重合体配位子では、作動寿命が著しく延長された。
    (2) 塩化ビニリデン共重合体とCoP錯体から、緻密かつ強靭な膜を作成、CoPを経由した酸素の膜透過(促進輸送)を明瞭に観測した。酸素配位の膜内in situ分光解析と透過挙動のシュミレーション(二元モデル)から、CoP錯体間をホッピングして移行する酸素の拡散定数が算出できた。
    (3) 1-ビニルイミダゾール、4-ビニルピリジン、2-ビニルピリジンの各共重合体とCoPの錯体から順次成膜し、3層薄膜を作成した。積層CoP膜の酸素結合平衡曲線は単独膜の加算平均に合致し、広い酸素分圧範囲で酸素結合に応答する膜となった。現在、この3層積層膜で酸素の促進輸送を測定している。

  • 三次元ハイブリッド組織体

    科学研究費助成事業(山口東京理科大学)  科学研究費助成事業(重点領域研究)

    Project Year :

    1996
    -
    1998
     

     View Summary

    1.ポリ(N-ビニル-2-ピロリドン)やポリ(アクリル酸ナトリウム)と銀ナノクラスターの安定なハイブリッド組織体を構築し、この構造を明らかにすると共に、エチレンのエチレンオキシドへの選択的酸化反応の触媒として従来のものより一段と高活性であることを明らかにした。またNi/Pd二元金属ナノクラスター触媒によるニトロベンゼン誘導体の還元反応機構について新たな知見を得た。さらにCu/Pd二元金属ナノクラスター吸着分子のラマンスペクトルを測定し、このような合金系ではじめて表面増強効果を観察した。
    2. ポリエチレンオキシドを高分子溶媒としてヘムタンパク質を熱安定化し、DNA鎖を分子ワイヤーとする促進電子移動を実現した。さらにチオフェンアルデヒドをプロモーターとする金電極への配位固定化に成功した。
    3. 外部刺激や環境変化に動的に応答する機能材料を得ることを目的として、自己組織的に水素結合三次元ネットワークを形成する分子を用いて、液晶ゲル(動的不均一システム)およびイオン伝導性液晶(動的均一システム)を構築した。
    4. 共役高分子へ規則正しくラジカル置換基を導入した高スピンポリマーとして星型および多分岐型ポリ(フェノキシル置換フェニレン・ビニレンおよび-エチニレン)から、二次元または三次元的ラジカルポリマーに拡張展開し、スピン整列における共役高分子の次元効果を検証できた。
    5. これまで開発してきた代表的なゲル化剤を伴って、支持電解質を溶かした有機溶媒をゲル化することによってゲル電解質を作製し、このゲル電解質のイオンの電荷移動挙動を検討した。ゲル化剤分子の形成する三次元網目状ナノ組織体の中に取り込まれたイオン電荷が、バルク中と同様な動きをすることを明ら
    かにした。

  • One-Step Multi-electron Transfer for Molecular Conversion

    Project Year :

    1996
    -
    1998
     

     View Summary

    The research project aims at elucidating the multi-electron transfer process of oxygen molecules incorporated into the macromolecule-metal complexes, in order to establish novel molecular conversion processes which are promoted by the four-electron reduction of oxygen.
    Followings have been established : Detailed analysis of the oxygen splitting reaction by one-step four-electron transfer, establishment of oxidative polymerization facilitated by multi-electron transfer process, elucidation of multi-electron transfer process in molecular assemblies. Based on these results, a general strategy to allow molecular conversions to proceed efficiently by multi-electron transfer process has been provided.
    1. Multi-nuclear metal complexes that show one-step multi-electron transfer processes were synthesized and their structure was determined. A general method to provide a one-step multi-electron transfer was provided.
    2. Oxygen splitting reaction by way of a μ-dioxo intermediate MOM-OO-MOM was established.
    3. Synthesis of novel compounds, polysulfoniums and polythioethers, were established, and their properties were determined in detail.
    4. Structure and properties of molecular assembly systems were elucidated, in terms of photoelectron transfer process.
    5. Synthesis of high molecular-weight polyheteroacenes were established, and their physicochemical properties were determined.

  • Cooperative Oxygen-Binding of Salcomine/Polymer Composite and its Application as an On-off Device

    Project Year :

    1995
    -
    1996
     

     View Summary

    Salcomine (N,N'-disalicylidenethylenediaminocobalt)is the oldest known and the simplest example of oxygen-binding complexes. Salcomine micro-crystals homogeneously dispersed and supported in a polymer such as poly (methacrylate) not only worked as a reversible and specific oxygen-adsorbent under air at room temperature but discontinuously bound oxygen at the atmospheric oxygen partial pressure of ca. 15cmHg to give an on-off-like oxygen- binding curve. This specific oxygen-binding profile was analyzed with the equation for a cooperative effect, and was described with both a crystal structure change of salcomine and an interaction of salcomine with the surrounding polymer. The salcomine/polymer film reversibly bended or expanded and shrinked in response to the atmospheric oxygen pressure. This oxygen-responding streching of the film was ascribed to also the structure change of salcomine. A composite of salcomine with carbon powder was also prepared. The salcomine composite was heated up under 6V-application, and released bound oxygen repeatedly in response to the voltage on-off application.

  • 開殻系π共役ポリラジカルの光非線形性

    科学研究費助成事業(早稲田大学)  科学研究費助成事業(重点領域研究)

    Project Year :

    1995
    -
    1996
     

     View Summary

    開殻π共役ポリラジカルをはじめて対象として、従来にない特異な電子構造に基づく非線形光学特性を、光学実験と材料設計の両面から明らかにすることを本研究は目的としている。ポリ(フェノキシフェニレンビニレン)、ポリ(ガルビノキシフェニレンビニレン)、ポリ(ニトロニルニトロキシドフェニレンビニレン)を対象とし、透明領域、安定性(室温、測定条件下で半寿命半日以上)、スピン整列数の比較から、主鎖骨格としてポリ(ο-フェニレンビニレン)、側鎖ラジカル基としてオキシフェニル基を選定し、g桁で量合成した。フェノキシラジカルの発生方法として新たに、フィルム中でのラジカル生成が可能な光開裂基、ビスアリルオキシフォスフィンアジドおよびビスアリルオキサレートを導入したポリフェニレンビニレンを新しく合成し、フィルム状態での白色光照射により、効率の高いポリラジカル生成を可能とした。Z-スキャン法にてヒドロキシフェニル基を有する前駆ポリマーとオキシフェニル基を有したポリラジカルの非線形光学特性を比較した。虚部の波形パターンより、前駆体では誘導吸収が、ポリラジカルでは吸収飽和が確認された。また実部の波形解析より、両試料とも非線形屈折率は負であった。透過率変化は測定光強度に対してほぼ直線的に増加し、その傾きより3次非線形光学定数を算出した。ラジカルの寄与により、3次非線形光学定数の実部および虚部ともに2桁以上増大した。

  • Preclinical Evaluation Tests of Red Cell Substitutes by Microcirculatory Dynamical Analyzes

    Project Year :

    1995
    -
    1996
     

     View Summary

    This research is aimed to evaluate two kinds of blood substitutes in preclinical stage (A.totally synthetic heme and B.hemoglobin (Hb) vesicles) in microcirculation levels, changing the properties of those oxygen carriers and monitoring oxygen distribution in tissues by new apparatus for quantitative analyzes.
    In the 90% exchange transfusion tests of Hb vesicles in a 5% albumin solution using rats, stable blood gas parameters and tissue oxygen tension were observed during the entire experiment with almost perfect survival rate, indicating excellent oxygen transporting ability and high safety. The Hb vesicles modified with polyoxyethylene (Mw.5kD) was dispersed in an isotonic albumin solution, and the 90% exchange transfusion ws carried out with hamster whose back was equipped with dorsal skinfold chamber to visualize microvessels in the subcutaneous tissue. Microvascular diameter, blood velocity, functional capillary density, microvascular and interstitial oxygen tensions were measured to evaluate the microcirculatory dynamics of the modified Hb resicles.
    Tissue oxygenation of isolated perfused liver was measured quantitatively from the intensity of NADH autofluorescence in periprotal and pericentral regions of the hepatic parenchyma. The excellent properties of cellular Hb compared with acellular one and the effect of surface modification were confirmed from the measurements of microcirculation dynamics.
    The totally synthetic heme oxygen carriers also showed oxygen binding ability similar to red blood cells in both in vitro and in vivo measurements. Those fruits will be necessarily to apply those materials in clinical trials in near future.

  • 精密合成高分子による動的構造制御

    科学研究費助成事業(九州大学)  科学研究費助成事業(総合研究(B))

    Project Year :

    1995
     
     
     

     View Summary

    本総合研究では、シーケンス、キラリティーなどを精密に制御した「新高分子」を合成し、これを利用して「ナノ組織体」を構築し、よって新しいナノ化学の発展に寄与することを目的とする重点領域研究「新高分子ナノ組織体」の発足をスムーズに行い、本重点領域の実をあげるため、計画研究分担者間の連絡を密にとり、本領域の発展をめざした。
    具体的には、まず領域代表者、研究代表を中心とした総括班会議(出席者7名)を開き、本領域の計画研究の具体的進め方について調査し、それに基づいて議論し方向付けを行った。また、計画研究について、分担者を含めた全体会議を開催し(出席者24名)、本重点領域研究のあり方について、領域代表者から研究方針を説明するとともに、各分担者の研究計画について具体的説明を開き、全体で議論し、お互いの分担の仕方、協力方法などについて計画を詰めた。さらに本分担者らで分担しきれない領域についてもどのようにするか意見交換し、本領域全体の発展を期した。公募研究が明らかになった段階で、その採否を決める審査会を開催し、優れた研究計画を選定した。

  • 開殻系π共役ポリラジカルの光非線形性

    科学研究費助成事業(早稲田大学)  科学研究費助成事業(重点領域研究)

    Project Year :

    1995
     
     
     

     View Summary

    スピンが全分子に亘って非局在化し、π共役分子内で強磁性的秩序がはじめて成立したポリフェニレンビニレンラジカルを対象に、非線形光学特性を測定解析し、閉殻系共役分子では実現しえない非線形性を光学実験と材料設計の両面から検討することを目的としている。
    (1)ポリフェニレンビニレンに共役して2,6-ジ-t-ブチルフェノキシ基、ガルビノキシル基、t-ブチルニトロキシド基、ニトロニルニトロキシド基を導入したポリラジカル量を合成した。これらポリラジカルの安定性は込み入った構造などから、むしろ低分子ラジカルよりも高い。フィルム状態、室温大気下でのラジカル半減期は1〜数日であった。
    (2)これらポリラジカルは新しい化合物であるので、基底多重項状態にあることを低温磁化測定より確認した。
    (3)これらポリフェニレンビニレンは吸収域300〜400nmの共役系であった。ラジカルは可視部に弱い吸収を持つ場合が多かった。
    フィルムについてメーカーフリンジ法で3

  • Research for Molecular Assembly of Heme Derivatives and Their Electronic Process

    Project Year :

    1993
    -
    1995
     

     View Summary

    Ten amphiphilic derivatives of tetraphenylporphyrin or protoporphyrin were synthesized, and their molecular assembling structures such as vesicles and fibers were analyzed with microscopic (TEM,cryo-TEM,SEM), and spectroscopic (UV-Vis., fluorescence) measurements. Especially, the microstructures of porphyrin ring such as accumulation and orientation were clarified by calculation with an exiton-coupling model. A main factor to make lipidporphyrin assemblies was concluded to be hydrophilic-hydrophobic balance and tertiary molecular structure of porphyrin as well as solution conditions.
    From the construction of the matrix by self-assembling of lipidporphyrin derivatives, the prevention of the inner-sphere electron transfer at metal-complex site become possible, and thus stable oxygen-binding complex was formed in the physiological condition. Especially, oxygen-binding complex could be formed firstly by molecular assembling phenomena even for the heme with no specific bulky substituents.From the analyzes of oxygen coordination process with laser flash time-resolved photometry, the degree of oxygen-affinity was clarified to be regulated by controlling electron density of central iron by electron donation from coordinated base at a fifth coordination site.
    Lipidprotoporphyrin was incorporated spontaneously into the bilayr membrane of the phospholipid vesicles. The fact that four-substituted protoporphyrin derivatives did not form the mu-oxo dimer in bilayr membrane. That leads to the realization of oxygen-binding complex of protoporphyrin derivatives due to the regulation of electronic process at complex site. The oxygen-coordination equilibrium of protoheme was controlled by gel-to-liquid crystalline phase transition temperature of the bilayr. Furthermore, in the care of porphyrin assembly, molecules were recognized by molecular packing states and it was clarified kinetically that electron transfer with high selectivity occurred from the excited triplet state.
    In conclusion, the electron process and control of molecular interaction were made possible by the formation of porphyrin assemblies.

  • New preparation of Oxygen-Permselective Membranes and their Application for the Air Battery of Next Generation

    Project Year :

    1993
    -
    1995
     

     View Summary

    Oxygen-permselective membranes for the air battery of next generation were studied from the view point of facilitated transport of oxygen. Oxygen permeation through membranes was measured electrochemically with a half cell by detecting the reduction current of the permeated oxygen on a carbon electrode. This method was especially effective for the facilitated oxygen transport thorugh the membranes containing cobaltporphyrin as an oxygen-specific fixed carrier. The facilitated oxygen transport was also observed for a liquid membrane containing bovine hemoglobin. Chemically specific surface diffusion of oxygen was successfully realized on a porous glass membrane modified on its pore surface with cobaltporphyrin. The membrane displayd both permselectivity for oxygen and high permeability. The enhanced and specific diffusion of oxygen was analyzed with a parallel model involving surface diffusion of oxygen. Barrier property against water vapor was given to the membranes by coating a thin layr of fluoro-polymer or by polyvinyliden chloride polymer. The facilitated factor of oxygen was augmented to 80 for these membranes.

  • Developmental Research on the New Synthesis of Poly (arylene thioether) and Its Performance

    Project Year :

    1992
    -
    1994
     

     View Summary

    Diphenyl disulfide (DPS) which has been a non-polymerizable monomer is oxidatively polymerized via cationic active species to yield poly (p-phenylene sulfide) (PPS). Oxidation of DPS in acidic media resulted in the formation of phenylbis (phenylthio) sulfoniumcation, which substitutes electrophilically on the phenylene ring of sulfides. The electrophilic substitution and the oxidation are continuously repeated to yield pure and linear PPS.In the presence of a catalytic amount of vanadium complexes, O_2-oxidative polymerization of DPS proceeds through two-electron transfer under the atmosphere at room temperature. A new one-pot synthesis of PPS was also established as a method by using more simple row materials, such as p-xylene and sulfur chloride, as a monomer. The polymerization is applicable to synthesize a variety of new poly (arylene sulfide)s which bear high performances.
    In this research project, we found a new reaction that methyl phenyl sulfide was oxidatively polymerized to yield poly (phenylsulfonium cation), which is soluble in common organic solvent at room temperature. The polysulfonium is feasible to convert to the corresponding polythioether with a high molecular weight and a high melting temperature.

  • 新しい分子磁性系の設計と構築

    科学研究費助成事業(京都大学)  科学研究費助成事業(重点領域研究)

    Project Year :

    1992
    -
    1994
     

     View Summary

    本研究組織は、これまでに提案されている理論とこの重点領域研究のA03班により新たに創出される分子設計指針に基づいて、新しい分子磁性系の構築を行う。とくに、(1)遷移金属元素を全く含まない純有機の強磁性体、(2)高いキュリー温度を有する純有機フェリ磁性体、(3)局在スピンと伝導電子とが共存・相互作用する有機磁性金属、(4)有機高分子強磁性体そして(5)高いキュリー温度を有する分子性遷移金属錯体強磁性体のそれぞれの合成は、本研究の主なる目標である。本年度は本重点領域研究の最終年であり、蒸気の目標を達成すべき努力した結果、評価すべき多大な姓かを挙げることができた。すなわち、(1)については有機ラジカル結晶で新たに8個の強磁性体が、そして有機電荷移動錯体で3個の強磁性体がそれぞれ得られた。いずれの強磁性体もキュリー温度は1 K以下と低いが、種々異なる分子構造および結晶構造を有する強磁性体が得られたことで、より高いキューリ温度を達成する上での有力な指針が確立された。(2)については、スピン数の異なる2つのニトロニルニトロキシドの1:1結晶で、平均4つの対が反強磁性的相互作用することが認められた。(3)については、有機磁性金属を作成する上で有力な電子供与体および電子受容体の合成に成功した。(4)では高分子のパイ共役主鎖に硬い共役平面を有するポリ(フェニレンビニレン)を用いることにより、側鎖に置かれた複数ラジカル間に有機高分子では初めて強磁性的なスピン相互作用が観測された。(5)では、高いキュリー温度を実現する上で必要とされる架橋基の選択と金属周りの最隣接金属イオン数の増大のうち後者をとくに注目して、新たに金属錯体強磁性体の合成に成功した。これまでになく高いキュリー温度(18.6K)が見いだされた。

  • Dynamics and Interfacial Property of Polymers Super-saturated with Oxygen

    Project Year :

    1992
    -
    1994
     

     View Summary

    Molecular oxygen is dissolved into pokymer matrixes more than hundred times of the physically dissolved oxygen for macromolecular complexes, which is ascribed to chemically specific, rapid, and reversible oxygen-binding to the compelex moieties. Characteristics the polymers super-saturatrd with oxygen was first studied in view points of specific oxygen sorption at the gas-solid polymer interface, surface diffusion of oxygen on the polymer matrixes, and polymer property conjugated with the oxygen dissolution.
    (1) Dissolved oxygen amount 3cm^3 (STP) /g (polymer) (at 25゚C under air atmosphere) into solid-atate cobaltporphyrin-bound polymers was estimated and analyzed with Langmuir's and Henry's isotherms. Oxygen-binding reactivity was controlled with the chemically modified structure of porphyrin, which was related to extra-large amount and rapid kinetics of oxygen sorption.
    (2) Two-dimensional of surface diffusion of oxygen was first observed on a porous membrane modified on its pore surface with cobaltporphyrin. The membdrane displayd high permeability >10^4 Barrers and permselectively for oxygen -2. The enhanced and specific diffusion of oxygen was mathematically analyzed with a parallel model involving surface diffusion of oxygen and gas phase diffusion, to yield permeability -10^3 Barrers for the surface diffusion layr and surface diffusion constant of oxygen 10^<-4> cm^2 s^<-4>.
    (3) Oxygen sorption amount-oxygen partial pressure relationship was steeply or non-continuously augmented at a specific oxygen pressure for the polymers involving micro-crystals of salcomine. This specific and on-off-type or sigmoidal-type oxygen sorption was reversibly and repeatedly observed. The specific oxygen sorption behabiour associated with a hysterisis isotherm was discussed with a cooperative interaction of crystal micro-structure of the oxygen-binding moiety and relaxation in the polymer matrix.

  • Conjugated Polymers Carrying Stable Radicals and Their Spin Control

    Project Year :

    1990
    -
    1991
     

     View Summary

    Synthesis and magnetic properties of new conjugated polymers carrying stable radicals were studied in connection with their electronic structure.
    Acetylene monomers, (3, 5-di-tert-butyl-4-hydroxyphenyl) acetylene and p-ethynylphenyl hydrogalvinoxyl, were synthesized using Vilsmeier method, and organolithium reagents, respectively. These monomers were polymerized with metathesis or Wilkinson catalyst to yield their polyacetylene derivatives, poly[(3, 5-di-tert-butyl-4-hydroxyphenyl)acetylene] (1) and poly (p-ethynylphenyl hydrogalvinoxyl) (2), with molecular weight of ca. 10^4. The polymers were soluble in common organic solvents and converted to the corresponding conjugated polyradicals via heterogeneous chemical oxidation using PbO_2 or alkaline K_3Fe (CN)_6. The polyradical 2 with extremely high spin concentration were obtained by regulating the oxidative conditions. The polyradicals were quite stable in solution and even in the solid state because of resonance stabilization and/or a steric effect of the substituens.
    Electronic state of these polyradicals were analyzed using ultraviolet photoelectron spectroscopy (UPS) and solution ESR spectra. The existence of significant pi-conjugation along the main chain in these polyradicals were examined by UPS. Decrease and increase in ionization threshold could be explained by the steric effect of sidechain substituent. ESR spectra with hyperfine structure for the oxidized 1 indicated that the phenoxy radical conjugates through the polyacetylene main chain over ca. 7 monomer units as a "neutral soliton". Antiferromagnetic interaction between the unpaired electrons was observed in 1 and from the temperature dependency of the ESR signal intensity.
    This research project revealed that magnetic properties of polyradical with polyacetylene backbone depend both on conjugated electronic state along main chain and on special arrangement of sidechain radical substituent.

  • ソフト相互作用と多重相互作用

    科学研究費助成事業(茨城大学)  科学研究費助成事業(重点領域研究)

    Project Year :

    1989
     
     
     

     View Summary

    本研究班の今年度の科学研究費による主な研究成果を以下に示す。1)幾つかの高分子遷移金属錯体の多段錯形成反応ならびに電子移動反応の動力学定数を決定し、高分大錯体のミクロドメインにおける特有な多重相互作用がこれらの反応速度に及ぼす効果を明らかにした。2)固相高分子に担持した銅ーアルミニウム錯体と一酸化炭素などの気体分子の相互作路を種々の分光学的方法を用いて定量的に観測し、分子識別機能の発現と多重相互作用の関係について解明した。3)アルドキシム型配位子などを担持した固相高分子配位子の物理的構造ならびに固相内部の親水性と疎水性構造のバランスがウラニルイオンなどとの錯形成に及ぼす効果について検討することによって、これら因子と多重相互作用の相関を具体的に解明し、多重相互作用と分子識別に対する基礎的な知見を得た。4)ポルフィリン錯体を高分子固相マトリックスに固定し、酸素、窒素などの気体分子の動的輸送過程を物理化学的に明らかにし、気体透過機構を明らかにすると共に、気体透過過程における高分子錯体の特異性を明かにした。5)種々の高分子ポルフィリン錯体を合成し、磁性発現における高分子イオンやポルフィリン環の役割について検討し、高分子錯体における磁気的性質と高分子錯体構造の関連を解明するための基礎的知見が得られた。
    これらの研究成果は、これまで殆ど知られていなかった高分子錯体におけるソフト相互作用と多重相互作用が、それらの反応性や分子識別に及ぼす影響を具体的、かつ定量的に明らかにし、機能発現につながる高次相互作用の概念を可なりの程度定量的解明に貢献することを可能ならしめた。

  • ソフト相互作用と多重相互作用

    科学研究費助成事業(茨城大学)  科学研究費助成事業(重点領域研究)

    Project Year :

    1988
     
     
     

     View Summary

    高分子金属錯体における特性発現の主要因子であるソフト相互作用と多重相互作用の解明を、62年度に引き続いて検討し、以下のような研究実績をあげた。
    高分子金属錯体溶液ならびにハイドロゲル-錯体系の電子移動反応における高分子鎖の配列やコンホメーションとレドックスセンター間の電子移動速度の関係を検討し、高分子マトリックス内における多重相互作用を定量的に解析した(栗村)。
    架橋ポリスチレン・塩化銅(I)固相系、高分子塩化銀アルミニウム溶液系、アルキルジアミン・塩化銅(I)溶液系、一級、二級または三級アミンを有するポリスチレン・塩化銅(I)固相系によるエチレンなどの吸着について検討した。三級アミノ基を有する系では、エタン、窒素および水素に対して選択性があることを見出した(平井)。
    クロロメチルスチレン-ジビニルベンゼンの球状共重合体を基本とするアルドキシム型樹脂ならびに大環状ポリアミンを固定化した樹脂について、ウラニルイオンや銅(II)イオンの吸着について検討した。その結果、細孔構造を有するMR型樹脂 とゲル型樹脂の吸着平衡挙動と多重相互作用の関係を明らかにした(江川)。
    種々のテトラフェニルポルフィリン金属錯体を側鎖に持つ高分子錯体の磁気的挙動について検討した。このうちエルビウム(III)錯体では、強磁性が観測され、f電子の利用とポルフィリン環の接近が強磁性発現に有望であることが見出された(蒲池)。
    高分子シクロペンタジエニルマンガン錯体での、窒素分子の選択的、可逆的配位について検討した。高速分光法によれば、固相系においても速度定数が10^5オーダーで可逆的吸着が進行することを見出し、配位相互作用に基づく促進効果を明らかにした(西出)。

  • 生体機能を有する有機金属化合物

    科学研究費助成事業(長岡技術科学大学)  科学研究費助成事業(特定研究)

    Project Year :

    1986
    -
    1988
     

     View Summary

    まず研究成果の中より直接有機金属化合物と関係する項目について報告する. 補酵素ビタミンB_<12>のもつコバルトー炭素結合の反応性は有機基質の特異的な骨格の転移を支配する. 生越は環状テトラピロールのC_0錯体であるB_<12>を利用する立場から, その周辺基の反応規制による不斉誘導をシクロプロパン誘導体を用いて検討し, その効果を解明した. 虎谷はさらに生体系に近い研究でB_<12>のC_0-C結合の反応性が, アポ酵素と補酵素間の結合により促進されることを証明した. 特に軸配位子の形状とサイズにより, C_0-C結合の開裂反応に違いが見られる. 田中は生体触媒の立場から, フェレドキシンモデルを触媒として電気化学的手法と組み合わせ, 有機基質への炭酸ガスの固定化, またルテニウム錯体を触媒として, 光化学反応により炭酸ガスの固定化に成功した. ついで癌治療を目指した研究において, 喜谷は白金錯体の構造と治療効果の相関を検討し, 錯体の水溶性を高めることにより, 臓器への特異性を向上させ, さらに副作用を抑制することに成功している. 木村は環状ポリアミン化合物, ジオキソサイクラムの新規合成を行い, その白金錯体のあるものは, 制癌効果をもつことを見いだした. 杉浦はブレオマイシンの制癌効果発現はDNAの特異的切断によることを解明したが, この鉄錯体の特異的な機能に注目し, ニトリル水和酵素の反応中心との類似性の高いことを見いだした. 西出は合成ヘムを高分子脂質に取り込ませた新しい系を構築し, 生理的条件下でデオキシ赤血球と酸素の交換反応を行い, 人工血液としての可能性のあることを示唆した. 小林はポルフィリン金属錯体と結合した一酸化炭素の反応性に関して理論的取り扱い, COと金属イオンの相互作用の重要性を指摘した.

  • ソフト相互作用と多重相互作用

    科学研究費助成事業(茨城大学)  科学研究費助成事業(重点領域研究)

    Project Year :

    1987
     
     
     

     View Summary

    高分子金属錯体に特有なソフト相互作用と多重相互作用を動的かつ定量的に解明する目的で, 初年度は以下のような研究実績をあげた.
    イミノー酢酸残基を有する高分子キレートと各種遷移金属イオンとの錯形成反応の生成定数を求め, 高分子キレート特有の多段錯形成を定量的に解析した. また, 高分子マトリツクス内の多重相互作用が高分子金属錯イオンの配位子置換反応の速度におよぼす効果を明らかにした(栗林).
    一酸化炭素, エチレン, プロピレンなどのオレフィンを種々の混合ガス中から選択的に吸着する各種高分子金属錯体を合成することに成功し, 気体分子の選択的吸着は,これら錯体と気体分子の多重相互作用に基いて, 分子識別が達成されるためであることを明らかにした(平井).
    アルドオキシム型キレート樹脂によるウランの選択吸着においては, 高分子マトリックスの種類, 樹脂の細孔構造, 親疏水性バランスなどとウラニルイオンや他の共存イオンの錯形成パラメータ, 吸着速度との関係の関係について検討し, 樹脂マトリックス内における多重相互作用と分子識別の関連を定量的に解析した(江川).
    側鎖に銅またはバナジウムなどのテトラポルフィリン錯体を結合する高分子錯体の側鎖間の不対電子相互作用を検討した. その結果いくつかの試料において, 部分的に強磁性体が生じていることを明らかにし, ソフト相互作用と磁性発現の関係について検討した(鎌池).
    高分子マトリックスに固定されたポリフィリン錯体を対称に, これらの膜と酸素, 窒素分子などとの多重相互作用を解析し, 固相系においても溶液系同じ動力学があてはまることを示し, 気体分子の促進輸送における錯体の効果の定量化に必要な各種動的パラメータを算出した(西出).

  • Study for a cell-Recognized Oxygen Transporthr using the Macromolecular Assebly-Embedded Heme

    Project Year :

    1985
    -
    1987
     

     View Summary

    The object of this research is to establish an artifical oxygen transporter, whieh transports sufficient oxygen in a living body without toxicity, with mactomolecular assembly-embedded hems. This study is a basec and debelopmental scientific reseatch in the final stage for practical use as an artificail red blood cell.
    1. The system, mainly composed by lipid-heme and polymerzed lipids, was selected to be Prepared as concentrated solution in a large quantity for transfution to samall animals.
    2. The heme embedded liposome was a stable with particle size of 400A, and it was strageable for months without aggregation and fusion. Its solotuon property was almost the the same as thet of blood.
    3. The oxygen-binding ability in the a concd. solution system was analyzed spectroscopically: its exygen-binding addinity(p1/2) and life-time (<tru>) were 30-40 mmHg and more the 1 day, respectively.
    4. Oxygen was arpidly transtrred quantitatively from the macromolecuar assemby-embodded heme to red blood cell.
    5. Hemocompatibility was analyzed in vitro through physichemical measutemnts; the negative hemocompatibility was fond for an ordinary physiological method, blood flocuation was homever found in some cares when lagre quantity was contracted. There is ignorable incorporation to macrofarge.
    6. The oxygen transfer from the macromojecular assembly-embedded heme to veous bllod was confiramed with a liquid/liwquid artificial luns device: It supplied oxygen and remove carbon dioxide effectively, suggesting concrete oxygen transfer from the atrificial medium to the blood.
    7. Circular rest of the artificatl mwdium in dog kidnet clearified the at urine exprcted noemally the transtusion test of the atrificial medium to rabbit belly induced considerable recovety o hypozemis.
    8. The transgution test was also conducted in a small animal until 3/4 transfusion. The most edfective macromolecular assembly system was selected to supply efficient oxygen in a blood for a requred period of time.

  • 生体機能を有する有機金属化合物

    科学研究費助成事業(長岡技術科学大学)  科学研究費助成事業(特定研究)

    Project Year :

    1986
     
     
     

     View Summary

    1.生体中に存在する有機金属化学種としてビタミン【B_(12)】以外の新しいものが見い出されている。特に人体では薬物代謝に関係するヘム酵素は、接触サイクル中に有機ヘムを経て非可逆的失活する。この過程に関連するモデル反応をポルフィリンコバルト錯体を用い、蛋白内の反応をNMRで追跡する方法を確立した。(生越)2.ミセル水溶中における四鉄クラスター【〔Fe_4S_4(SR)_4〕^(2~)】(1)またはダブルキュバン型モリブデン-鉄クラスター【〔Mo_2Fe_6S_8(SR_9〕^(3~)】(2)(R=アルキル,アリール)について種々の水素イオン濃度における酸化還元挙動ならびにプロトン化挙動を明らかにした。(田中)3.Redox-activeなアキシャル有機ドナー(カテコール,キノン等)と、大環状ポリアミン内に捕択されたredox-activeな金属イオンとの相互作用により、従来にはない、新しい有機・金属-coupling-redox系化合物がつくられた。(木村)4.Co(【III】)TPP(【CF_3】【SO(~3^~)】)は非配位性溶媒中で、ポルフィリンπ電子が中心金属イオ

  • Synthesis of Crystalline Poly(phenyleneether)s by Interfacial Electron-transfer Polymerization

    Project Year :

    1985
    -
    1986
     

     View Summary

    The objective of this research is to study new synthesis procedure of poly(phenyleneether)s with sharp molecular weight distribution and high crystallinity by controlling interfacial electron-transfer of phenol. Anodic oxidation of phenols gave the corresponding poly(1,4-phenyleneoxide)s by selecting the interfacial electron-transfer conditions. The investigators found that phenolate ion is polymerized quantitatively to poly(phenyleneether) in the presence of bromine or alcohol. They act as an electron-transfer mediator in the polymerization. Polymerization of phenol with bisphenol gave the poly(phenyleneether) having phenolic hydroxy groups on both the chain ends. Polymerization of phenols having trimethylsilyl groups also gave corresponding poly(phenyleneether)s. Linear 1,4-phenylene structure of thus formed poly(phenyleneethers)s was confirmed by NMR, IR, and DSC in the reference of model phenyleneether compounds. Electrochemical measurements on the interfacial electron-transfer indicated that the polymerization proceeds within diffusion layer on the electrode interface and this interfacial step controls the reaction selectivity to yield poly(phenyleneether)s. The interfacial electron-transfer procedure was applied to a series of aromatic compounds. Under specififc electron-transfer conditions, benzene derivatives such as p-dimethoxybenzene and cyclicdienes such as cyclohexadiene gave new conjugated polymers: poly(2,5-dimethoxy-1,4-phenylene) and poly(1,4-cyclohexadiene). Strong basic compounds inhibited the polymerization, which suggested that cation radical formed by one-electron transfer on the electrode interface is an active species of this polymerization. As mentioned above, electro-oxidative polymerization of phenols was characterized in connection with the interfacial electron-transfer process on the electrode and was developed as a new polymerization procedure of aromatic polymers.

  • Magnetic Property of Polymer-Rare Earth Complexes

    Project Year :

    1985
    -
    1986
     

     View Summary

    The objective is to prepare polymer complexes with rare earth ions in which a spin-spin interaction is expected between the polymer-bound ions and to study their magnetic property in connection with the matrix structure. Complexation of copolymer of methacrylic acid and acrylamide and of polyethyleneoxide-grafted polymethacrylic acid with rare earth ions such as Eu, Tb, and Sm was studied by potentiometric titration using modified Bjerrum's method. The copolymers formed the [rare earth ion (carboxylate)3] complex with large complex formation constants. Very large entropy change in the complexation contributed to the stable complex formation. The complexation was affected by distance between coordination sites and flexibility and hydration of the polymer chain. The complexes with the copolymers of methacrylic acid and acrylate gave transparent and flexible films. Visible absorption and fluorescent spectroscopy indicated that the rare earth ions formed the tris-coordinate complexes even in the films and the complexed ion were uniformly dispersed in the films. The Gd complex films showed paramagnetism. In order to improve the structure of polymer complexes, polypyridilenemethylidenenitrio and poly- <alpha> -pyrralenine were synthesized as polymer ligands with conjugated structure and were complexed with Eu, Gd, and Fe ion. The Gd complexes were paramagnetic. On the other hand, the corresponding Fe complexes showed strong ferromagnetism. Moessbauer parameters suggested that a trace ofiron oxides contaminated the polymer complexes and that the definite polymer matrices protectediron oxides as ultra fine particles in their domain. As mentioned above, new results to approach a polymeric magnetic substance were obtained by using the polymer-rare earth complexes.

  • 集積型ポルフィリン高分子錯体による酸素促進輸送

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    高分子配位子鎖上に、酸素分子結合の動的および平衡挙動の異なる一連のポルフィリン錯体が連続して結合した「集積型」のポルフィリン高分子錯体を構築し、これら錯体から薄膜を作成、膜内に選択的かつ多量に取り込まれた酸素分子が、ポルフィリン錯体の集積場内を結合脱着を繰り返しながら拡散する動的過程を高速分光および透過測定から同時解析し、酸素が選択的に透過する促進輸送現象として実証することを目的とした。(1)配位子部に水素結合をもつ高分子配位子としてポリ(4(5)-ビニルイミダゾール-コ-オクチルメタクリレート)を新しく合成、そのコバルトポルフィリン錯体で最大の酸素親和性を観測した。膜の酸素透過係数は供給酸素分圧が低い領域で著しく増大した。(2)π共役高分子配位子としてポリ(3,4-アゾピリジン)およびピリジルアセチレンとフェニルアセチレンの共重合体を合成した。ポルフィリン錯体は可逆的に酸素結合したが、溶液、固相膜中で親和性は低かっ

  • 集積型ポルフィリン高分子錯体による酸素促進輸送

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    高分子配位子鎖上に、ポルフィリン錯体が連続して結合した「集積型」錯体を構築し、これら錯体の膜内に選択的かつ多量に取り込まれた酸素分子が、ポルフィリン錯体の集積場内を結合脱離を繰り返しながら拡散する動的過程を高速分光および透過測定から同時解析し、酸素が選択的に透過する促進輸送現象として実証することを目的としている。(1)ポリ(4-ピリジルアセチレン-コ-フェニルアセチレン)-コバルトピケットフェンスポルフィリン錯体を合成した。この錯体膜での酸素透過係数は、10^8桁と大きく、かつ高い選択性(酸素/窒素)=15が実現した。この効率高い促進輸送がポルフィリン錯体の大きなk_<off>によることを解析できた。(2)ジアミノピリジンとアニリンの共重合体のポルフィリン錯体の導電度は10^<-2>Scm^<-1>で、酸素結合能と導電性をあわせ付与できた。(3)ポルフィリン錯体集積膜での酸素透過現象を局所濃度ゆらぎモデルで解析した。酸素分子の拡散項と酸素結合(化学)反応

  • Establishment of production process of cellular- type oxygen carriers

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    In order to establish the large-scale production process of cellular-type oxygen carriers (hemoglobin (Hb)-vesicles), the following subjects were finished.1. Carbonylation and deoxygenation process of the Hb solutions : The carbonylation (CO) and deoxygenation of a hemoglobin (Hb) solution were performed with an artificial lung.2. Electrochemical deoxygenation of the HbO_2 solution : The dissolved oxygen (pO_2<1O Torr) was electrochemically reduced to water under the diluted hydrogen/ nitrogen mixture gas condition.3. Ligand-exchange process of HbCO to HbO_2 : The Ligand-exchange process was carried out by visible-light irradiation to the HbCO solution using a liquid thin film or a silicon hollow fiber module.4. Synthesis of new aminolipids and the use : The polyoxyethylen-conjugated or negatively-charged aminolipids were newly synthesized and the Hb-vesicles were prepared with these lipids.5. Scaling up of an extrusion process : To improve the efficiency of the extrusion process, the mixced lipid dispersion was previously freeze-mawed and -dried. The necessary time during the extrusion process of the dispersion of the powder to the Hb solution was largely reduced, and the efficiency of the extrusion was also dramatically increased with the multistage-combined type extruder.6. Evaluation of the 10L-scale production of the Hb vesicles : The apparatus in an each process was lined, and me 10L-scale production of the Hb vesicles are being evaluated. The pilot plants on the scale of 300 L will be planned

  • Development of Multi-Spin Conjugated Polymers with Large Magnetic Moment as a New Magneto-Responsible Organic Material

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    π-Conjugated but non-Kekule-type polymers behave as a multi-spin organics with large molecular-based magnetic moment, and respond magnetically. The objective of this research is to characterize these multi-spin conjugated polymers as a magneto-responsible but purely organic material. Linear, star-shaped, and hyperbranched poly(4-phenoxyl- or - diphenylaminium-1,2-phenylenevinylene)s were synthesized. Atomic force and magnetic force microscopy were applied to monitor the molecular image and the weak magnetic image of these polymers. Magnetic response in the magnetic force microscopy exactly corresponded to spin density, size and shape of the polymer at a single-molecular level. It is concluded that magnetic force microscopy is an effective tool to detect a very weak magnetic signal of such multi-spin organic polymers and that the polymer molecule is a potentially new material of nanometer-sized and molecular-based magnetic dots

  • Precision Synthesis of Poly(thiophene)s by oxidative polymerization

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    Alkyl-sulfinyl substituted poly(l,2-phenyleneoxide) and poly(1,3-phenylene) are prepared by oxidative polymerization under air to lead them the double-stranded structure via oxidation and superacid-induced intraraolecular condensation. The extended π-conjugation system of the result polymers is also discussed. Additionally, a depolymerization of the polymers consisted of alkylsulfinyl phenols are revealed and applied to the control of molecular weight.(1) Synthesis of the helical polymer consisted of condensed thiophene rings. A oxidative polymerization of 4-methoxy-2-methylsulfinylphenol afforded the precursor poly(1,2-phenyleneoxide) with pendant methylsulfinyl groips. The following intramolecular condensation gave the phenoxathiinium-type helical ladder polymer. The absorption maximum and tail in the UV-vis spectrum of the ladder polymer showed bathochromicalfy shift comprable with those of the precursor polymer to suggest the extended π-conjugated planarity even in the helical structure. A Pd catalyzed polymerization of 1,3-benzene bis(boronate) and methylthio substituted 1,3-dibromobenzene provided the corresponding poly(1,3-phenylene). The oxidation and the intramolecular condensation of the pendant groups were carried out to yield the helical ladder polymer. The stricture was characterized by NMR, IR and Elemental analysis, the absorption spectrun revealed the delocalization of the π-electron.(2) Study of the polymerization and depolymerization kinetics. In order to control the nolecular weight of the poly (alkylsulfinyl-phenyleneoxide), the condition of depolymerization of poly (2,6-dimethyl-1,4-phenyleneoxide) (PPO) was studied. An addition of 2,6-dimethylphenol and evaluated phenoxy-radicals in the oxidative condition shifted the equilibrium to the depolymerization of the polymer. The molecular weight after the depolymerization depended on the concentration of the terminal OH groups and agreed with the theoretical calculated molecular weight. A presence of the intermediate phenoxy-radical in the ESR and the rate constants from UV-vis spetra indicated the depolymerization of polyfphenyleneoxide) was occurred by the repetitive redistribution

  • Hydrophobic Porphyrin Assemblies with Oxygen-Transporting Capability

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    Hemoglobin is a protein containing iron porphyrin as an oxygen-binding site and uptakes and carries molecular oxygen from air selectively. Designing assemblies focused on hydrophobicity of the precisely synthesized porphyrin enables to realize novel oxygen-carrying materials which work under conditions that different from that of hemoglobin.The hydrophobic iron porphyrin was hybridized with the xylanase which Nakamura have previously reported its stability against temperature. The red-colored aqueous solution of porphyrin-xylanase hybrid displayed a reversible oxygen-binding to the iron porphyrin even at high temperature at ca. 90℃. The catalytic activity as the xylanase was not interfered because the coordination site is different from that of the catalytic activity. This simple strategy using hydrophobic interactions will be applicable to the other host-guest combinations, which could afford a totally new class of artificial hemoprotein architectures.Meso-tetra(2-pyridyl) porphyrin forms a duplex with tetrahydroxylcalix[4]arene via triplicate or quadruple hydrogen bonds, to provide a capping structure on the porphyrin plane, which was accompanied by the spontaneous equilibrium shift of the atropisomers. This was the first example of a hydrogen-bonded porphyrin-calix[4]arene duplex.Polymeric cobalt tetraphenylporphyrin thin membrane was obtained with nanometer thickness (80nm from SEM). The homogeneous red membrane reversibly binds and releases molecular oxygen at room temperature under high pressure. Oxygen permeability coefficient was large and steeply increased with decrease in oxygen upstream pressure. Oxygen permselectivity at 1cmHg difference between upstream and downstream was over 150. This indicates that the fixed cobalt porphyrin in the solid membrane facilitated oxygen transport in the membrane. Compressed air was applied to the upstream in the same condition to give the oxygen concentration above 900% at downstream. This indicates weak oxygen-binding affinity is preferable for the efficient oxygen facilitated transport

  • ポリチアヘテロヘリセンの新しい合成と分子ソレノイドの創出

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    純有機物質での「分子ソレノイド」(有機導線でつくられたナノサイズの電磁石)はその特異な光学特性や高度に制御された三次構造から新たな物質系として期待される。本研究では、チオフェン環を含むらせん型芳香族高分子「ポリチアヘテロヘリセン」を設計・合成した。さらにらせんの巻き性の新たな制御法を見出し、またらせんに沿った電子伝導の生起をシミュレーションから理論予測した。(1)ベンゾチオフェン型共役らせん高分子の合成とヘリシティの制御Pd触媒を用いたカップリング反応によりキラルアルキルチオ置換ポリ(1,3-フェニレン)を合成、側鎖を酸化した。続いて、強酸中での分子内閉環を経て、ポリ(チアヘテロヘリセン)を構造欠陥なく得た。前駆未閉環体はクロロホルム/アセトニトリル(貧溶媒)混合溶液中では270-310nmの領域に3つのCotton効果を示し、そのCD強度は溶液塩度とともに著しく減少した。それに対し閉環重合体のCDはクロロホルム溶液中でも275-330nmに4つのCotta効果を示し、そのCDスペクトル・強度はともに溶媒、溶液温度に依存することなく一定であった。これより、得られたポリチアヘテロヘリセンが巻き性が制御されかつ剛直ならせん構造を有していることが明らかとなった。(2)らせんに沿った電子伝導の理論予測分子ソレノイドを見据えて、ポリチアヘテロヘリセンの電子伝導をシミュレーションから理論予測した。モデルとしてベンゾチオフェンが4つ縮合した分子を設定し、これを2つの金電極間に金-チオール結合で結合させたものに対して、電極間の電圧と電子透過度の関係を計算した。電圧-電子透過度の計算結果は金のフェルミ準位付近でのらせん鎖に沿った電子透過を示した。これは低い電圧下でもらせん鎖に電流が発生することを示唆しており、分子ソレノイド創出の確かな足掛かりとなった

  • Synthesis of New π-Conjugated Polymers and Their Spin-Correlated Function

  • Control of Super-Hierarchical Helical Structures of Next-Generation Conjugated Polymers and Their Innovative Functions

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    The present research area has aimed to explore profound potentialities of conjugated polymers and to extract innovative electronic, magnetic and optical functions that should give rise to the next-generation materials. The project has focused on (i) synthesis of novel and fruitful conjugated polymers by means of sophisticated designs for molecules and chemical reactions, and (ii) super-hierarchical control covering primary to higher order structures, and morphological control of self-organized assemblies and complexes, and (iii) precise evaluation of physical properties and investigation of intrinsic functions by virtue of well defined multi-layered structures. Through rigorous achievement of the project, we have fostered and cultivated the scientific field of conjugated polymers

  • Synthesis of Radical Polymers and their Application as an Organic Radical Battery

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    (1) Main chain structure and its redox-activity A polyether derivative bearing the redox-active 2,2,6,6-tetramethylpiperidinyl-N-oxy (TEMPO) moiety was insoluble, but slightly swollen in the electrolyte solution. The glass transition temperature (T_g) was below room temperature, and more flexible than the polymethacrylate derivatives. The cell performance fabricated with this polymer was maintained even with a higher radical polymer loading in the composite electrode, which revealed the flexible polyether backbone could contribute to its higher compatibility with the electrolyte solution and the current collector, and could also serve as a matrix for rapid electron transfer.Photocrosslinking was chosen as a method for providing tunable solubility of the radical polymer, increasing mechanical toughness of the film, improving design flexibility and enabling patterning of the device. A photocrosslinked TEMPO-substituted polynorbomene was obtained using a bis(azide) crosslinker, which was carefully designed to eliminate side reactions on the nitroxide moiety. The obtained radical thin film exhibited a rapid and reversible redox at 3.58 V vs. Li/Li^+ and served as a cathode-active material even without any current collector. This approach facilitated battery manufacture via a wet, printable, and rollable process, leading to an organic-based, flexible paper battery.(2) Electron transfer process of the radical polymer film and fabrication of the composite electrode A radical film obtained by photocrosslinking of the poly(TEMPO-substituted norbomene) displayed the redox behavior with a narrow peak-to-peak separation, resulting from the surface-confined redox species, which supported the rapid and quantitative electron transfer within 250 nm thickness. A SEM image of the radical polymer/carbon composite electrode also showed the carbon nanofiber was fully covered with the polymer (ca. 100 nm thickness) and suggested the electron can be transferred by the electron-hopping mechanism within the polymer layer.(3) N-type radical polymers and their application as a totally organic-derived secondary battery Cyclic voltammetry, in-situ electrolytic ESR and UV/vis spectroscopy revealed that the reversible p-type redox of poly[4-(N-t-butyl-N-oxylamino)styrene], attributed to the oxoammonium cation formation and n-type redox of poly(nitroxylstyrene) o-substituted with trifluoromethyl group corresponding to the aminoxy anion formation, was tuned by the electronic effects of substituent groups. P-and n-type redox switching with chemical modification also promises a potential application of these polymers as cathode-and anode-active materials in all-organic batteries. Poly(galvinoxylstyrene) exhibited a reversible redox at 3.15 V vs. Li/Li+ under basic conditions, attributed to the n-type redox reaction between the galvinoxyl radical and galvinoxylate anion. A test cell fabricated with this polymer anode and poly(TEMPO-substituted norbornene) cathode, displayed stable charge-discharge curves at a plateau voltage of 0.66 V, which agreed well with the difference of the formal redox potentials for both radical polymers.Through this study, the redox activity of the radical polymers has been correlated with their chemical structures and an all-organic-based battery was constructed, for the first time, with both radical polymers

  • SOMO Design of Radical Polymers for Development of Fully Organic Rechargeable Batteries

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    We have been developing "organic radical batteries" by fabricating the prototypes using organic radical polymers as electode-active materials. The radical batteries are characterized by the unprecedented battery performances that accomplish both a high energy density and an excellent power rate capability, taking advantage of the designable polymer chain and the fast electron transpfer kinetics found for the radical pendants. The present research aims at establishing novel organic electrodes by unraveling the the electron-and mass-transfer processes of the radical polymers, in pursuit of basic principles that dominate the organic redox reactions through singly occupied molecular orbitals(SOMO). Rational molecular design and synthesis of radical polymers have been attempted with a view to further improve the energy and power densities to provide next-generation and sustainable organic rechargeable batteirs

  • エネルギーデバイスを目指した高密度電子輸送材料の創製

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    本研究では、負極活物質として電極反応速度が大きく、還元ドープにより高容量が期待できる新規なn型活性ポリマーを設計・合成することを目的とする。具体的には、還元電位と電子移動速度を制御して、n型活性なポリマーを探索した。n型ドープ状態の安定化に働く各種因子を解明し、卑な電位で安定度高く電子貯蔵できるポリマーを合成した。さらに、安定ラジカル種に関する申請者の従来知見を活用し、ニトロニルニトロキシド、フェノキシル、ガルビノキシルおよびセミキノンラジカルへと拡張し、斬新なn型活性物質群として確立した。(1)n型ポリマーの合成前年度に選定されたn型活性なレドックス席を有するメタ(ア)クリレード、スチレン誘導体などを合成し、対応するポリマーを得た。カルボニル基が隣接位に置換したアシルニトロキシドモノマーは、対応するヒドロキシルアミンを出発物として、酸クロ法により保護基、ビニル基を導入して得た。重合後、ベンゾイル基の脱保護、酸化を経てニトロキシドポリマーを得た。(2)n型ラジカルポリマーの拡張ガルビノキシルおよびフェノキシルとの関連から、キノン/セミキノンラジカルをレドックス席に有するポリマーを合成した。セミキノンラジカルの安定度の向上と、キンヒドロン生成の抑制が期待できる主鎖型および剛直なペンダント構造を有するポリマーを合成した。(3)全有機二次電池の試作ポリマー膜内の電子・イオンの拡散過程を解析し、負極活物質と導電性部材との複合化について検討した

  • Development of Organic Memory Devices Using Radical Polymers

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    Organic aliphatic polymers bearing a redox-active robust radical pendant per repeating unit have been applied as key materials for organic polymer memo-ries that are viewed as next-generation memory devices. Synthesis of the so-called radical polymers with designed SOMO levels and elucidation of charge injection mechanisms at polymer/metal interfaces allowed fabrication of nonvolatile memories with ON/OFF ratio of more than 10^5, high cycle durability, and excellent bistability. Factors that dominate the electric bistability in response to the applied voltage have been determined, which offered insight into the design principles of entirely organic organic memories. Thin devices made of the radical polymer layers sandwiched by two metal electrodes demonstrated the mem-ory properties at low applied voltages, which were based on the characteristic charge in-jection and transport behaviors found for the radical polymers

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Specific Research

  • ラジカルポリマーの有機化学を基盤とする光電変換・蓄電物質の創製

    2011  

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    ラジカルポリマーが有機ラジカル電池の電極活物質を構成しうるとの発見とその分子化学の確立を起点として、電荷の分離・輸送・貯蔵に関わる複合機能制御や、分子レベルから界面およびバルクスケールまで俯瞰した高次構造制御により、革新的な光・電子デバイスを構成する有機分子群を創出した。特に、SOMOのエネルギー準位と状態密度の制御により室温大気下で充分な寿命を持たせた不対電子の関わる有機・高分子化学を確立した。高分子ならではの非晶質凝縮系を活用して、単一電子の振舞いに基づく高速電荷輸送、高密度での電荷分離とイオン対生成、光・熱・電磁場への複合応答など有機安定ラジカル種に期待できる諸物性を増幅し、斬新な光・電子機能高分子を創出した。特に、高出力特性を有する次世代ラジカル電池の創製に絞って推進し、試作セルの作成と動作実証を含め具体的データを集積した。具体的には、室温大気下で安定なニトロキシドラジカル分子の電気化学的に可逆な一電子レドックスを二次電池の電極反応として着目し、p型およびn型活性の2種ポリマーをそれぞれ正・負極とした全有機電池のプロトタイプを試作、動作実証した。ラジカルポリマーの特徴に基づく高いエネルギー密度と、高速電子移動に由来するパワー密度をあわせ持ち、軽量かつ成形性にも優れる、他に類例のない電池特性を予備的に実現した。このような安定ラジカル種が関与する電子移動過程の確立を基盤として、革新的な「次世代ラジカル電池」および「ラジカル太陽電池」の創出を目指して研究展開し、SOMO関与の斬新な有機・高分子物性を開拓した。(1) ラジカルポリマーの合成有機化学 ニトロキシドやガルビノキシルなど安定ラジカル種の性質を、従来確立してきた電極電位に対する応答(電気化学反応)に加え、有機分子としての基礎的性質を全容解明することを第一着手とした。これらと干渉しない重合開始剤や生長末端について知見を集積し、分子量制御、立体規則性重合、ラジカルブロック・グラフトポリマーの生成を可能とする精密重合を展開した。(2) 非共役系での導電現象の確立と深化 ラジカルレドックス席を、その溶存限界を超えて高密度で含有させた非晶質ポリマーが形成する電解質膨潤ゲルが密集席間の交換反応に基づく優れた電荷輸送特性を発現するとの発見に基づいて、濃度勾配を駆動力とした化学反応の繰返しによる電荷輸送をマクロな導電現象として捉え、二次電池、色素増感太陽電池など湿式デバイスを構成する新材料を創出した。(3) 安定ラジカル種の有機光・電気化学の確立 SOMO関与の光物理過程や電子・エネルギー移動などの光反応について、安定ラジカル種の化学の立場から追究し、有機光・電気物性の未開拓分野に挑戦した。有機分子の励起状態の多重度、電子遷移確率、光電子移動、励起エネルギー移動に対するSOMOの介在効果を切り口として、ラジカルの光化学的性質を調べた。これらを基に、色素共存下の増感反応、逆電子移動抑制による電荷分離界面の構築、高密度・長距離電荷輸送など、光電変換や蓄電に関わる知見を集積した。

  • 水中でのポリフェニレンオキシドの合成とグリーンポリマーとしての展開

    2005  

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    ポリ(2,6-ジメチル-1,4-フェニレンオキシド)(PPO)は、トルエン等の有機溶媒および銅-アミン錯体触媒を用いた2,6-ジメチルフェノール(DMP)の酸化重合により合成されている。研究代表者らはヘキサシアノ鉄(III)酸カリウムを酸化剤とし、塩基に水酸化ナトリウムを用いた完全な水溶媒でのDMPの酸化重合(高分子量のPPOの生成)に成功している。一方、銅錯体触媒はアルカリ水溶液中では水酸化銅となり失活する。本課題では、種々の耐アルカリ性銅錯体を探索し、触媒サイクルでの水を溶媒としたDMPの酸化重合により高分子量PPOを合成することを目的とした。種々の水溶性銅錯体を触媒とし、水溶媒中、塩基に水酸化ナトリウムを用いて、DMPの酸化重合を実施した。水のpH、反応温度、界面活性剤種など反応条件を幅広く検討した結果、ジエチレントリアミン-N,N,N',N",N"-五酢酸(DTPA)銅錯体およびエチレンジアミン-N,N,N',N'-四酢酸(EDTA)銅錯体を触媒とする酸化重合において、定量的に分子量1万以上の白色粉末状のポリマーが得られた。生成したポリマーは塩析等により水溶媒から析出するため濾過により容易に分離できた。得られたポリマー構造および物性は、有機溶媒を用いた従来法PPOと同等であった。銅錯体触媒は水相に溶解しているため、分離ポリマーの銅含有量は、従来法PPOに比べ極めて低い良好な値を示した。フェノールの銅-DTPAへの配位速度定数は、550 nm可視吸収の変化より5.0×10-5 M s-1で、銅-ピリジン錯体へのそれ(9.0×10-2 M s-1)に比べ低いが、重合は酸素吸収量の飽和より18時間で終了することを明らかとし、銅錯体触媒を用いた水溶媒中でのDMPの酸化重合を実証した。環境適合のエンプラ合成法として可能性を提示できた。

  • 血液代替物に関する研究「血液代替物国際会議」(International Symposium on BloodSubstitutes)

    1995   土田 英俊, 酒井 清孝, 土屋 喜一, 櫻井 英博, 野呂 影勇, 武岡 真司, 小林 紘一, 関口 定美, 清水 勝, T.M.S. Chang, R. Winslow, J.H. Fhurhop, J.C. Bakker

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    本学では,血液の酸素運搬機能を代替できる人工赤血球を中心とし,広く血液機能代替物全般に関する展開を目指した先駆的研究を推進している。具体的な研究成果も系統的に重なり始め,臨床を目指した展開も急速になってきているので,この分野で先駆ける成果と世界の第一人者を集めて国際会議を本学で開催するため,調査および打合せ会(於 海外も含む)を実施し,準備を整えた。血液代替物の物質科学の基礎と展開動向,臨床適応,更には,代替物に対するガイドラインや将来の血液事業,臓器移植への利用,新しい治療法などの波及効果など,対象となる学際的内容の全てを集中して議論した(成果は学術誌に総説等としても印刷中)。血液代替物,特に人工赤血球実現の道筋を拓くと共に,ワセダ型人工赤血球を関連研究者に周知できた。この間「日本血液代替物学会」(初代より会長本学土田英俊教授,本学内に事務局設置)も発展し,国際的にも本学は重点的立場にあり,発言力も高まった。更に本学が橋渡し役を務めながら,現在産業界と厚生省,赤十字社などの官庁側の連繁も構成されつつあり,今日緊急課題であるAIDS等汚染の全くない血液代替物の開発研究の社会要請に応える状況にもなった。 以上の準備作業と研究進展の背景をもとに,97年9月8~10日本学に於て血液代替物国際会議の開催が決定した。国際主要研究者から成る委員会も設置され,全面的な協力をとりつけた。幸い本学の国際会議開催助成にも採択されたので,1st Circularを配布して広報に当たっている。関連シンポジウムも含めて欧米以外で初めて開催される国際会議として多数の関心を得はじめている。この学際的な新分野を本学の主導のもとに確立すると共に,先導的な意義と波及効果を広くアピールする同国際会議の準備を完了できた。