2022/07/31 更新

写真a

ゴトウ カズマ
後藤 和馬
GOTOH Kazuma
所属
自然科学学域 准教授
職名
准教授
外部リンク

学位

  • 博士(理学) ( 筑波大学 )

研究キーワード

  • Inorganic Physical Chemistry

  • 無機物理化学 固体物性 磁気共鳴 ナノ空間 細孔物質 炭素材料

研究分野

  • ナノテク・材料 / ナノ構造物理

  • ナノテク・材料 / ナノ構造化学

  • ナノテク・材料 / 無機・錯体化学

  • ナノテク・材料 / 基礎物理化学

  • ナノテク・材料 / 無機物質、無機材料化学

学歴

  • 筑波大学   Graduate School, Division of Chemistry  

    - 2002年

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経歴

  • 岡山大学 学術研究院 自然科学学域   准教授

    2021年4月

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  • 岡山大学   The Graduate School of Natural Science and Technology   准教授

    2016年4月 - 2021年3月

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委員歴

  • 炭素材料学会   運営委員  

    2017年1月 - 現在   

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    団体区分:学協会

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  • 炭素材料学会   次世代の会 幹事長  

    2017年1月 - 2018年12月   

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    団体区分:学協会

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  • 固体NMR材料・フォーラム   運営委員  

    2016年10月 - 現在   

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    団体区分:学協会

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  • 炭素材料学会   編集委員  

    2014年12月 - 2019年12月   

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    団体区分:学協会

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論文

  • Supercapacitor electrode with high charge density based on boron-doped porous carbon derived from covalent organic frameworks

    Shigeyuki Umezawa, Takashi Douura, Koji Yoshikawa, Yohei Takashima, Mika Yoneda, Kazuma Gotoh, Vlad Stolojan, S. Ravi P. Silva, Yasuhiko Hayashi, Daisuke Tanaka

    Carbon   184   418 - 425   2021年10月

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    掲載種別:研究論文(学術雑誌)   出版者・発行元:Elsevier BV  

    DOI: 10.1016/j.carbon.2021.08.022

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  • Na3V2O2(PO4)2F3-2 as a stable positive electrode for potassium-ion batteries

    P. Ramesh Kumar, Kei Kubota, Yusuke Miura, Mirai Ohara, Kazuma Gotoh, Shinichi Komaba

    Journal of Power Sources   493   2021年5月

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    掲載種別:研究論文(学術雑誌)  

    Reversible potassium ion insertion into Na3V2O2x(PO4)2F3-2x, which is regarded as a solid solution between Na3V3+2(PO4)2F3 and Na3V4+2O2(PO4)2F is demonstrated for the first time. V3+/V4+-mixed Na3V2O2x (PO4)2F3-2x-multiwalled carbon nanotube (MWCNT) composite was prepared by a conventional hydrothermal reaction. Na3V2O2x(PO4)2F3-2x-MWCNT composite exhibiting an average electrode potential of 3.7 V in a potassium cell due to the cumulative inductive effect of phosphate fluoride oxide. The prepared composite delivers an initial discharge capacity of 118 mAh g−1 at 0.1C (13 mA g−1) rate with good cycle stability and high-rate capability performances. The electrochemical measurements, energy dispersive X-ray analysis, ex-situ, and operando X-ray diffractions provide new insights into reversible phase transformations during the subsequent cycles after an electrochemical K/Na exchange process at the initial cycle.

    DOI: 10.1016/j.jpowsour.2021.229676

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  • MgO-Template Synthesis of Extremely High Capacity Hard Carbon for Na-Ion Battery

    Azusa Kamiyama, Kei Kubota, Daisuke Igarashi, Yong Youn, Yoshitaka Tateyama, Hideka Ando, Kazuma Gotoh, Shinichi Komaba

    Angewandte Chemie - International Edition   60 ( 10 )   5114 - 5120   2021年3月

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    掲載種別:研究論文(学術雑誌)  

    Extremely high capacity hard carbon for Na-ion battery, delivering 478 mAh g−1, is successfully synthesized by heating a freeze-dried mixture of magnesium gluconate and glucose by a MgO-template technique. Influences of synthetic conditions and nano-structures on electrochemical Na storage properties in the hard carbon are systematically studied to maximize the reversible capacity. Nano-sized MgO particles are formed in a carbon matrix prepared by pre-treatment of the mixture at 600 °C. Through acid leaching of MgO and carbonization at 1500 °C, resultant hard carbon demonstrates an extraordinarily large reversible capacity of 478 mAh g−1 with a high Coulombic efficiency of 88 % at the first cycle.

    DOI: 10.1002/anie.202013951

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  • Vanadium diphosphide as a negative electrode material for sodium secondary batteries

    Shubham Kaushik, Kazuhiko Matsumoto, Yuki Orikasa, Misaki Katayama, Yasuhiro Inada, Yuta Sato, Kazuma Gotoh, Hideka Ando, Rika Hagiwara

    Journal of Power Sources   483   229182 - 229182   2021年1月

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    掲載種別:研究論文(学術雑誌)   出版者・発行元:Elsevier BV  

    DOI: 10.1016/j.jpowsour.2020.229182

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  • Crystal structures of four isomeric hydrogen-bonded co-crystals of 6-methyl­quinoline with 2-chloro-4-nitro­benzoic acid, 2-chloro-5-nitro­benzoic acid, 3-chloro-2-nitro­benzoic acid and 4-chloro-2-nitro­benzoic acid

    Kazuma Gotoh, Hiroyuki Ishida

    Acta Crystallographica Section E: Crystallographic Communications   76   1701 - 1707   2020年11月

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    掲載種別:研究論文(学術雑誌)  

    The structures of the four isomeric compounds of 6-methyl­quinoline with chloro- and nitro-substituted benzoic acids, C7H4ClNO4·C10H9N, namely, 2-chloro-4-nitro­benzoic acid-6-methyl­quinoline (1/1), (I), 2-chloro-5-nitro­benzoic acid-6-methyl­quinoline (1/1), (II), 3-chloro-2-nitro­benzoic acid-6-methyl­quinoline (1/1), (III), and 4-chloro-2-nitro­benzoic acid-6-methyl­quinoline (1/1), (IV), have been determined at 185-190 K. In each compound, the acid and base mol­ecules are linked by a short hydrogen bond between a carboxyl O atom and an N atom of the base. The O⋯N distances are 2.5452 (12), 2.6569 (13), 2.5640 (17) and 2.514 (2) Å, respectively, for compounds (I)-(IV). In the hydrogen-bonded acid-base units of (I), (III) and (IV), the H atoms are each disordered over two positions with O site:N site occupancies of 0.65 (3):0.35 (3), 0.59 (4):0.41 (4) and 0.48 (5):0.52 (5), respectively, for (I), (III) and (IV). The H atom in the hydrogen-bonded unit of (II) is located at the O-atom site. In all of the crystals of (I)-(IV), π-π inter­actions between the quinoline ring system and the benzene ring of the acid mol­ecule are observed. In addition, a π-π inter­action between the benzene rings of adjacent acid mol­ecules and a C - H⋯O hydrogen bond are observed in the crystal of (I), and C - H⋯O hydrogen bonds and O⋯Cl contacts occur in the crystals of (III) and (IV). These inter­molecular inter­actions connect the acid and base mol­ecules, forming a layer structure parallel to the bc plane in (I), a column along the a-axis direction in (II), a layer parallel to the ab plane in (III) and a three-dimensional network in (IV). Hirshfeld surfaces for the title compounds mapped over d norm and shape index were generated to visualize the weak inter­molecular inter­actions.

    DOI: 10.1107/S2056989020013134

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  • Reaction behavior of a silicide electrode with lithium in an ionic-liquid electrolyte

    Yasuhiro Domi, Hiroyuki Usui, Kai Sugimoto, Kazuma Gotoh, Kei Nishikawa, Hiroki Sakaguchi

    ACS Omega   5 ( 35 )   22631 - 22636   2020年9月

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    掲載種別:研究論文(学術雑誌)  

    Silicides are attractive novel active materials for use in the negative-electrodes of next-generation lithium-ion batteries that use certain ionic-liquid electrolytes; however, the reaction mechanism of the above combination is yet to be clarified. Possible reactions at the silicide electrode are as follows: deposition and dissolution of Li metal on the electrode, lithiation and delithiation of Si, which would result from the phase separation of the silicide, and alloying and dealloying of the silicide with Li. Herein, we examined these possibilities using various analysis methods. The results revealed that the lithiation and delithiation of silicide occurred.

    DOI: 10.1021/acsomega.0c03357

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  • Mechanisms for overcharging of carbon electrodes in lithium-ion/sodium-ion batteries analysed by operando solid-state NMR 査読

    Kazuma Gotoh, Tomu Yamakami, Ishin Nishimura, Hina Kometani, Hideka Ando, Kenjiro Hashi, Tadashi Shimizu, Hiroyuki Ishida

    Journal of Materials Chemistry A   8 ( 29 )   14472 - 14481   2020年7月

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    担当区分:筆頭著者, 責任著者   掲載種別:研究論文(学術雑誌)  

    DOI: 10.1039/d0ta04005c

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  • Accommodation of a large amount of lithium ions in silsesquioxane-pillared carbon: A potential anode of an all-solid-state lithium ion battery

    Yoshiaki Matsuo, Yuta Ogawa, Takeshi Kai, Ai Aoto, Junichi Inamoto, Kazuma Gotoh

    Chemistry Letters   49 ( 7 )   757 - 759   2020年6月

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    掲載種別:研究論文(学術雑誌)  

    More than 25 weight percent of lithium ions were accommodated in silsesquioxane-pillared carbon with very small interlayer expansion. It delivered reversible capacity of 1023mAh/g with a relatively high first columbic efficiency of 67% and good cycling property as an anode of an all-solid-state lithium ion battery.

    DOI: 10.1246/CL.200177

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  • Structural Analysis of Sucrose-Derived Hard Carbon and Correlation with the Electrochemical Properties for Lithium, Sodium, and Potassium Insertion 査読 国際誌

    Kei Kubota, Saori Shimadzu, Naoaki Yabuuchi, Satoshi Tominaka, Soshi Shiraishi, Maria Abreu-Sepulveda, Ayyakkannu Manivannan, Kazuma Gotoh, Mika Fukunishi, Mouad Dahbi, Shinichi Komaba

    Chemistry of Materials   2020年3月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    DOI: 10.1021/acs.chemmater.9b05235

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  • Crystal structures of the two isomeric hydrogen-bonded cocrystals 2-chloro-4-nitrobenzoic acid-5-nitroquinoline (1/1) and 5-chloro-2-nitrobenzoic acid-5-nitroquinoline (1/1)

    Kazuma Gotoh, Hiroyuki Ishida

    Acta Crystallographica Section E: Crystallographic Communications   75   1694 - 1699   2019年11月

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    掲載種別:研究論文(学術雑誌)  

    The structures of two isomeric compounds of 5-nitroquinoline with chloro-and nitro-substituted benzoic acid, namely, 2-chloro-4-nitrobenzoic acid-5-nitroquinoline (1/1), (I), and 5-chloro-2-nitrobenzoic acid-5-nitroquinoline (1/1), (II), both C7H4ClNO4·C9H6N2O2, have been determined at 190 K. In each compound, the acid and base molecules are held together by an O-H..N hydrogen bond. In the crystal of (I), the hydrogen-bonded acid-base units are linked by a C-H..O hydrogen bond, forming a tape structure along [1 0]. The tapes are stacked into a layer parallel to the ab plane via N-O..π interactions between the nitro group of the base molecule and the quinoline ring system. The layers are further linked by other C-H..O hydrogen bonds, forming a three-dimensional network. In the crystal of (II), the hydrogen-bonded acid-base units are linked into a wide ribbon structure running along [1 0] via C-H..O hydrogen bonds. The ribbons are further linked via another C-H..O hydrogen bond, forming a layer parallel to (110). Weak π-π interactions [centroid-centroid distances of 3.7080 (10) and 3.7543 (9) Å] are observed between the quinoline ring systems of adjacent layers. Hirshfeld surfaces for the 5-nitroquinoline molecules of the two compounds mapped over shape index and d norm were generated to visualize the weak intermolecular interactions.

    DOI: 10.1107/S2056989019013896

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  • States of thermochemically or electrochemically synthesized NaxPy compounds analyzed by solid state 23Na and 31P nuclear magnetic resonance with theoretical calculation 査読

    R. Morita, K. Gotoh, M. Dahbi, K. Kubota, S. Komaba, K. Tokiwa, S. Arabnejad, K. Yamashita, K. Deguchi, S. Ohki, T. Shimizu, R. Laskowski, H. Ishida

    J. Power. Sources   413   418 - 424   2019年

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    DOI: 10.1016/j.jpowsour.2018.12.070

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  • Correlation of carbonization condition with metallic property of sodium clusters formed in hard carbon studied using 23Na nuclear magnetic resonance 査読

    R. Morita, K. Gotoh, K. Kubota, S. Komaba, K. Hashi, T. Shimizu, H. Ishida

    Carbon   145   712 - 715   2019年

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

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  • Negative dielectric constant of water confined in nanosheets 査読

    A. Sugahara, Y. Ando, S. Kajiyama, K. Yazawa, K. Gotoh, M. Otani, M. Okubo, A. Yamada

    Nature Commun.   10   850   2019年

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

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  • Crystal structures of 3-chloro-2-nitro-benzoic acid with quinoline derivatives: 3-chloro-2-nitro-benzoic acid-5-nitro-quinoline (1/1), 3-chloro-2-nitro-benzoic acid-6-nitro-quinoline (1/1) and 8-hy-droxy-quinolinium 3-chloro-2-nitro-benzoate 査読

    K. Gotoh, H. Ishida

    Acta Cryst.   E75   1552 - 1557   2019年

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

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  • Non-destructive, uniform, and scalable electrochemical functionalization and exfoliation of graphite 査読

    Benoît D.L. Campéon, Mitsuo Akada, Muhammed S. Ahmad, Yasushi Nishikawa, Kazuma Gotoh, Yuta Nishina

    Carbon   158   356 - 363   2019年

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

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  • Crystal structure of 4-chloro-2-nitro­benzoic acid with 4-hy­droxy­quinoline: a disordered structure over two states of 4-chloro-2-nitro­benzoic acid–quinolin-4(1H)-one (1/1) and 4-hy­droxy­quinolinium 4-chloro-2-nitro­benzoate 査読

    K. Gotoh, H. Ishida

    Acta Cryst.   E75   1694 - 1699   2019年

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

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  • Development and Characterization of a Poly (Vinyl Alcohol)/Graphene Oxide Composite Hydrogel as An Artificial Cartilage Material 査読

    Yibo Zhao, Wataru Terai, Yuko Hoshijima, Kazuma Gotoh, Koji Matsuura, Kazuaki Matsumura

    Applied Sciences   8 ( 11 )   2272 - 2272   2018年11月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:MDPI AG  

    Poly (vinyl alcohol) hydrogel (PVA-H) is expected to be a suitable artificial articular cartilage material because of its high biocompatibility. However, it is difficult to affix to the surface of a living joint because it is bioinert and its mechanical strength needs to be improved. In this study, graphene oxide (GO) subjected to two oxidation rounds was used to form a nanocomposite material and the composite hydrogel PVA-GO-H was prepared by low-temperature crystallization. Scanning electron microscope (SEM) images showed that the addition of GO can increase roughness of the hydrogel surface. Contact angle measurements showed that the surface of PVA-GO-H exhibited hydrophobicity that increased with GO concentration and not with that of PVA-H, indicating that the hydrophilic parts of PVA and GO form hydrogen bonds and the hydrophobic part of GO was exposed on the surface. Tensile tests demonstrated that Young’s modulus was enhanced on the addition of GO. Osteoblast cells showed more affinity for PVA-GO-H than PVA-H, which much more cells adhere to than to PVA-GO-H after a certain period of culturing, suggesting GO can improve the cell attachment of PVA-H. Further studies on the influence of the oxidation time of GO are still required.

    DOI: 10.3390/app8112272

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  • Structure and Dynamic Behavior of the Na-Crown Ether Complex in the Graphite Layers Studied by DFT and 1H NMR 査読

    Kazuma Gotoh, Shinya Kunimitsu, Hanyang Zhang, Michael M. Lerner, Keisuke Miyakubo, Takahiro Ueda, Hyung-Jin Kim, Young-Kyu Han, Hiroyuki Ishida

    Journal of Physical Chemistry C   122 ( 20 )   10963 - 10970   2018年5月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:American Chemical Society  

    Diffusion of alkali metals in graphite layers is significant for the chemical and electrochemical properties of graphite intercalation compounds (GICs). Crown ethers co-intercalate into graphite with alkali metal (Na and K) cations and form ternary GICs. The structures and molecular dynamics of 15-crown-5 and 18-crown-6 ether coordinating to Na+ or K+ in GICs were investigated by DFT calculations and 1H solid state NMR analyses. DFT calculations suggest a stacked structure of crown ether-metal complex with some offset. 1H NMR shows two kinds of molecular motions at room temperature: isotropic rotation with molecular diffusion and axial rotation with fluctuation of the axis. The structure and dynamics of crown ether molecules in GIC galleries are strongly affected by the geometry of the crown ether molecules and the strength of the interaction between alkali metal and ligand molecules.

    DOI: 10.1021/acs.jpcc.8b02965

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  • Surface modification effects on the tensile properties of functionalised graphene oxide epoxy films 査読

    Koji Matsuura, Yuki Umahara, Kazuma Gotoh, Yuko Hoshijima, Hiroyuki Ishida

    RSC Advances   8 ( 18 )   9677 - 9684   2018年

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Royal Society of Chemistry  

    Graphene oxide (GO) is a candidate for nanofillers to improve the mechanical and thermal stability of nanocomposites. In order to determine the molecular interaction to improve the mechanical properties of GO-epoxy resin composites, we investigated the relationship between GO oxidation properties and the tensile strength of the epoxy resin. With respect to GO preparation, graphite was oxidised by the Brodie or Hummers method, and the oxidised GO was reduced or chloride substituted. The X-ray photoelectron spectroscopy (XPS) spectral patterns indicate that a shorter Brodie oxidation method GO (B-GO) is associated with a higher proportion of hydroxyl groups. The oxidised GO materials, with the exception of the sample produced by the 54 h Brodie oxidation method, improved the tensile strength of the composites while the epoxy resin with reduced or chlorinated GO did not increase the tensile strength of the film. Based on XPS and elemental analyses, the improvement in the tensile strength is due to the presence of O atom based functional groups, such as hydroxyl groups, on the GO surface. The interaction between the epoxy resin and O atom based functional groups on the GO contributes to improving the tensile strength of the composites.

    DOI: 10.1039/c8ra00252e

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  • Bis(pyrrolidinium) hexachloridostannate: a redetermination

    K. Gotoh, H. Ishida

    IUCrData   3   x181397   2018年

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

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  • Crystal structures of two hydrogen-bonded compounds of chloranilic acid-ethyleneurea (1/1) and chloranilic acid-hydantoin (1/2) 査読

    K. Gotoh, H. Ishida

    Acta Cryst.   E74   1727 - 1730   2018年

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

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  • Metaheuristic Ab Initio Optimum Search for Doping Effects in Nanocarbons 査読

    Tsuruta Kenji, Mitani Keiichi, Al Asad, Md. Abdullah, Nishina Yuta, Gotoh Kazuma, Ishikawa Atsushi

    THERMEC 2018: 10TH INTERNATIONAL CONFERENCE ON PROCESSING AND MANUFACTURING OF ADVANCED MATERIALS   941   2356 - 2359   2018年

  • Enhanced Li-Ion Accessibility in MXene Titanium Carbide by Steric Chloride Termination 査読

    Satoshi Kajiyama, Lucie Szabova, Hiroki Iinuma, Akira Sugahara, Kazuma Gotoh, Keitaro Sodeyama, Yoshitaka Tateyama, Masashi Okubo, Atsuo Yamada

    ADVANCED ENERGY MATERIALS   7 ( 9 )   1601873   2017年5月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:WILEY-V C H VERLAG GMBH  

    Pseudocapacitance is a key charge storage mechanism to advanced electrochemical energy storage devices distinguished by the simultaneous achievement of high capacitance and a high charge/discharge rate by using surface redox chemistries. MXene, a family of layered compounds, is a pseudocapacitor-like electrode material which exhibits charge storage through exceptionally fast ion accessibility to redox sites. Here, the authors demonstrate steric chloride termination in MXene Ti2CTx (T-x: surface termination groups) to open the interlayer space between the individual 2D Ti2CTx units. The open interlayer space significantly enhances Li-ion accessibility, leading to high gravimetric and volumetric capacitances (300 F g(-1) and 130 F cm(-3)) with less diffusion limitation. A Li-ion hybrid capacitor consisting of the Ti2CTx negative electrode and the LiNi1/3Co1/3Mn1/3O2 positive electrode displays an unprecedented specific energy density of 160 W h kg(-1) at 220 W kg(-1) based on the total weight of positive and negative active materials.

    DOI: 10.1002/aenm.201601873

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  • Synthesis, characterization, crystal structure and theoretical studies on 4-bromo-2-[(E)-6-methyl-2-pyridyliminomethyl]phenol 査読

    Aliakbar Dehno Khalaji, Hossein Mighani, Milad Kazemnejadi, Kazomu Gotoh, Hiroyuki Ishida, Karla Fejfarova, Michal Dusek

    ARABIAN JOURNAL OF CHEMISTRY   10   S1808 - S1813   2017年5月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:ELSEVIER SCIENCE BV  

    The Schiff base compound, 4-bromo-2-[(E)-6-methyl-2-pyridyliminomethyl] phenol, has been synthesized by a reaction of 5-bromosalicylaldehyde with 6-methyl-2-aminopyridine and characterized by elemental analyses, 1 H-NMR spectroscopy and X-ray single-crystal diffraction. The title compound crystallizes in monoclinic system, space group P2(1)/c, with a=13.2721(12) angstrom, b=4.5481(4), c =19.972 (2), beta=96.653 (3)degrees , V=1197.4 (2)(3) and Z=4. The molecular geometry obtained from X-ray crystallography has been compared with that of the title compound in the ground state calculated by using the density function method (B3LYP) with 6/31G basis set. Calculated results show that DFT can well reproduce the structure of the title compound. The DFT results show that the molecule exists only in enol form. The molecular conformation of the title compound is stabilized by an intramolecular O1-H1 center dot N1 hydrogen bond. (C) 2013 Production and hosting by Elsevier B.V. on behalf of King Saud University.

    DOI: 10.1016/j.arabjc.2013.07.007

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  • Crystal structures of three hydrogen-bonded 1:2 compounds of chloranilic acid with 2-pyridone, 3-hydroxypyridine and 4-hyroxypyridine 査読

    Kazuma Gotoh, Hiroyuki Ishida

    Acta Crystallographica Section E: Crystallographic Communications   73 ( 10 )   1546 - 1550   2017年

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:International Union of Crystallography  

    The crystal structures of the 1:2 compounds of chloranilic acid (systematic name: 2,5-dichloro-3,6-dihydroxy-1,4-benzoquinone) with 2-pyridone, 3-hydroxypyridine and 4-hyroxypyridine, namely, bis(2-pyridone) chloranilic acid, 2C5H5NO·C6H2Cl2O4, (I), bis(3-hydroxypyridinium) chloranilate, 2C5H6NO+·- C6Cl2O4 2-, (II), and bis(4-hydroxypyridinium) chloranilate, 2C5H6NO+·- C6Cl2O4 2-, (III), have been determined at 120 K. In the crystal of (I), the base molecule is in the lactam form and no acid-base interaction involving H-atom transfer is observed. The acid molecule lies on an inversion centre and the asymmetric unit consists of one half-molecule of chloranilic acid and one 2-pyridone molecule, which are linked via a short O-H· · ·O hydrogen bond. 2-Pyridone molecules form a head-to-head dimer via a pair of N-H· · ·O hydrogen bonds, resulting in a tape structure along [201]. In the crystals of (II) and (III), acid-base interactions involving H-atom transfer are observed and the divalent cations lie on an inversion centre. The asymmetric unit of (II) consists of one half of a chloranilate anion and one 3-hydroxypyridinium cation, while that of (III) comprises two independent halves of anions and two 4-hydroxypyridinium cations. The primary intermolecular interaction in (II) is a bifurcated O-H· · ·(O,O) hydrogen bond between the cation and the anion. The hydrogen-bonded units are further linked via N-H· · ·O hydrogen bonds, forming a layer parallel to the bc plane. In (III), one anion is surrounded by four cations via O-H· · ·O and C-H· · ·O hydrogen bonds, while the other is surrounded by four cations via N-H· · ·O and C-H· · ·Cl hydrogen bonds. These interactions link the cations and the anions into a layer parallel to (301).

    DOI: 10.1107/S2056989017013536

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  • Crystal structures of two 1:2 dihydrate compounds of chloranilic acid with 2-carboxypyridine and 2-carboxyquinoline 査読

    Kazuma Gotoh, Hiroyuki Ishida

    Acta Crystallographica Section E: Crystallographic Communications   73   1840 - 1844   2017年

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:International Union of Crystallography  

    The crystal structure of the 1:2 dihydrate compound of chloranilic acid (systematic name: 2,5-dichloro-3,6-dihydroxy-1,4-benzoquinone) with 2-carboxypyridine (another common name: picolinic acid
    systematic name: pyridine-2-carboxylic acid), namely, 2C 6 H 5.5 NO 2 0.5+ C 6 HCl 2 O 4-2H 2 O, (I), has been determined at 180K, and the structure of the 1:2 dihydrate compound of chloranilic acid with 2-carboxyquinoline (another common name: quinaldic acid
    systematic name: quinoline-2-carboxylic acid), namely, 2C 10 H 7 NO 2 C 6 H 2 Cl 2 O 4 2H 2 O, (II), has been redetermined at 200K. This determination presents a higher precision crystal structure than the previously published structure [Marfo-Owusu &amp
    Thompson (2014). X-ray Struct. Anal. Online, 30, 55-56]. Compound (I) was analysed as a disordered structure over two states, viz. salt and co-crystal. The salt is bis(2-carboxypyridinium) chloranilate dihydrate, 2C 6 H 6 NO 2 + C 6 Cl 2 O 4 2-2H 2 O, and the co-crystal is bis(pyridinium-2-carboxylate) chloranilic acid dihydrate, 2C 6 H 5 NO 2 C 6 H 2 Cl 2 O 4 2H 2 O, including zwitterionic 2-carboxypyridine. In both salt and co-crystal, the water molecule links the chloranilic acid and 2-carboxypyridine molecules through O-HO and N-HO hydrogen bonds. The 2-carboxypyridine molecules are connected into a head-to-head inversion dimer by a short O-HO hydrogen bond, in which the H atom is disordered over two positions. Compound (II) is a 1:2 dihydrate co-crystal of chloranilic acid and zwitterionic 2-carboxyquinoline. The water molecule links the chloranilic acid and 2-carboxyquinoline molecules through O-HO hydrogen bonds. The 2-carboxyquinoline molecules are connected into a head-to-tail inversion dimer by a pair of N-HO hydrogen bonds.

    DOI: 10.1107/S2056989017015997

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  • 微生物由来鞘状酸化鉄を利用した多孔質炭素材料および炭素-酸化鉄複合材料の作製 査読

    I. Nishimura, K. Gotoh, T.Hiura, H. Kawamura, H. Hasimoto, S. Matsumoto, J. Takada, T. Kasukabe, H. Nishihara, H. Goto, T.Ohkubo, H. Ishida

    炭素   280   188 - 197   2017年

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    記述言語:日本語  

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  • Crystal structures of 4-methoxybenzoic acid–1,3-bis(pyridin-4-yl)propane (2/1) and biphenyl-4,4'-dicarboxylic acid–4-methoxypyridine (1/2) 査読

    K. Gotoh, H. Ishida

    Acta Cryst.   73   1192 - 1196   2017年

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    DOI: 10.1107/S2056989017010167

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  • Slow Stabilization of Si-Li Alloys Formed during Charge and Discharge of a Si-C Mixed Electrode Studied by In Situ Solid-State Li-7 Nuclear Magnetic Resonance Spectroscopy 査読

    J. Arai, K. Gotoh, R. Sayama, K. Takeda

    JOURNAL OF THE ELECTROCHEMICAL SOCIETY   164 ( 1 )   A6334 - A6340   2017年

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:ELECTROCHEMICAL SOC INC  

    The charge-discharge behavior of a Si-C mixed electrode (Si: graphite = 20: 80 or 30: 70 (wt%)) was investigated using in situ solid-state Li-7 nuclear magnetic resonance (NMR) spectroscopy. The spectra revealed the formation of Li-Si alloys and the intercalation of Li into graphite during the charge process and the corresponding reverse process (Li extraction) during discharge. Li was mainly stored as a Li-Si alloy (Li15Si4 or Li15+delta Si-4) at high SOC (state of charge) values (above 80% SOC, low cell voltage region) and could be released from the alloy. The cell resistance measured by electrochemical impedance spectroscopy (EIS) increased steeply at high SOC values, revealing that structural changes in the Li-Si alloy may influence the electrode resistance. The NMR peaks observed upon formation of Li15Si4 or Li15+delta Si-4 shifted and decreased gradually, indicating that the Li-Si alloys are not sufficiently stable in the cell. (C) The Author(s) 2017. All rights reserved.

    DOI: 10.1149/2.0541701jes

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  • Structure and Dynamic Behavior of Sodium-Diglyme Complex in the Graphite Anode of Sodium Ion Battery by H-2 Nuclear Magnetic Resonance 査読

    Kazuma Gotoh, Hisashi Maruyama, Tatsuya Miyatou, Motohiro Mizuno, Koki Urita, Hiroyuki Ishida

    JOURNAL OF PHYSICAL CHEMISTRY C   120 ( 49 )   28152 - 28156   2016年12月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:AMER CHEMICAL SOC  

    Cointercalation systems consisting of graphite, sodium, and some linear glycol ethers (glymes) are anticipated for use as negative electrodes in sodium ion batteries because of their superior properties such as outstanding cycle performance. We synthesized a ternary intercalation compound consisting of sodium, deuterated diglyme (diglyme-d(14)), and graphite by a solution reaction. Then we investigated the dynamics and coordination structure of diglyme-d(14) molecules by H-2 solid-state NMR. Two diglyme molecules coordinate to each sodium ion rigidly, except for rotation of the methyl groups at low temperatures below 233 K. At room temperature, diglyme weakly coordinates to a Na ion through one oxygen atom of the ligand and rotates around the ONa axis. The active motion of sodiumdiglyme complexes is favorable for Na diffusion between graphene layers in the graphite intercalation compound.

    DOI: 10.1021/acs.jpcc.6b10962

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  • Surface and interlayer base-characters in lepidocrocite titanate: The adsorption and intercalation of fatty acid 査読

    Tosapol Maluangnont, Pornanan Arsa, Kanokporn Limsakul, Songsit Juntarachairot, Saithong Sangsan, Kazuma Gotoh, Tawan Sooknoi

    JOURNAL OF SOLID STATE CHEMISTRY   238   175 - 181   2016年6月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:ACADEMIC PRESS INC ELSEVIER SCIENCE  

    While layered double hydroxides (LDHs) with positively-charged sheets are well known as basic materials, layered metal oxides having negatively-charged sheets are not generally recognized so. In this article, the surface and interlayer base-characters of O2- sites in layered metal oxides have been demonstrated, taking lepidocrocite titanate K0.8Zn0.4Ti1.6O4 as an example. The low basicity (0.04 mmol CO2/g) and low desorption temperature (50-300 degrees C) shown by CO2- TPD suggests that O2- sites at the external surfaces is weakly basic, while those at the interlayer space are mostly inaccessible to CO2. The liquid-phase adsorption study, however, revealed the uptake as much as 37% by mass of the bulky palmitic acid (C-16 acid). The accompanying expansion of the interlayer space by similar to 0.1 nm was detected by PXRD and TEM. In an opposite manner to the external surfaces, the interlayer O2- sites can deprotonate palmitic acid, forming the salt (i.e., potassium palmitate) occluded between the sheets. Two types of basic sites are proposed based on ultrafast H-1 MAS NMR and FTIR results. The interlayer basic sites in lepidocrocite titanate leads to an application of this material as a selective and stable two-dimensional (2D) basic catalyst, as demonstrated by the ketonization of palmitic acid into palmitone (C-31 ketone). Tuning of the catalytic activity by varying the type of metal (Zn, Mg, and Li) substituting at Ti-IV sites was also illustrated. (C) 2016 Elsevier Inc. All rights reserved.

    DOI: 10.1016/j.jssc.2016.03.030

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  • Sodium-Ion Intercalation Mechanism in MXene Nanosheets 査読

    Satoshi Kajiyama, Lucie Szabova, Keitaro Sodeyama, Hiroki Iinuma, Ryohei Morita, Kazuma Gotoh, Yoshitaka Tateyama, Masashi Okubo, Atsuo Yamada

    ACS NANO   10 ( 3 )   3334 - 3341   2016年3月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:AMER CHEMICAL SOC  

    MXene, a family of layered compounds consisting of nanosheets, is emerging as an electrode material for various electrochemical energy storage devices including supercapacitors, lithium-ion batteries, and sodium-ion batteries. However, the mechanism of its electrochemical reaction is not yet fully understood. Herein, using solid-state Na-23 magic angle spinning NMR and density functional theory calculation, we reveal that MXene Ti3C2Tx in a nonaqueous Na+ electrolyte exhibits reversible Na+ intercalation/deintercalation into the interlayer space. Detailed analyses demonstrate that Ti3C2Tx undergoes expansion of the interlayer distance during the first sodiation, whereby desolvated Na+ is intercalated/deintercalated reversibly. The interlayer distance is maintained during the whole sodiation/desodiation process due to the pillaring effect of trapped Na+ and the swelling effect of penetrated solvent molecules between the Ti3C2Tx sheets. Since Na+ intercalation/deintercalation during the electrochemical reaction is not accompanied by any substantial structural change, Ti3C2Tx shows good capacity retention over 100 cycles as well as excellent rate capability.

    DOI: 10.1021/acsnano.5b06958

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  • Crystal structures of hydrogen-bonded co-crystals as liquid crystal precursors: 4-(n-pentyloxy)benzoic acid-(E)-1,2-bis(pyridin-4-yl)ethene (2/1) and 4-(n-hexyloxy)benzoic acid-(E)-1,2-bis(pyridin-4-yl)ethene (2/1) 査読

    Yohei Tabuchi, Kazuma Gotoh, Hiroyuki Ishida

    Acta Crystallographica Section E: Crystallographic Communications   72   1771 - 1775   2016年

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:International Union of Crystallography  

    The crystal structures of title hydrogen-bonded co-crystals, 2C12H16O3 C12H10N2, (I), and 2C13H18O3 C12H10N2, (II), have been determined at 93K. In (I), the asymmetric unit consists of one 4-(n-pentyloxy)benzoic acid molecule and one half-molecule of (E)-1,2-bis(pyridin-4-yl)ethene, which lies about an inversion centre. The asymmetric unit of (II) comprises two crystallographically independent 4-(n-hexyloxy)benzoic acid molecules and one 1,2-bis(pyridin-4-yl)ethene molecule. In each crystal, the acid and base components are linked by O - H⋯N hydrogen bonds, forming a linear hydrogen-bonded 2:1 unit of the acid and the base. The 2:1 units are linked via C - H⋯π and π-π interactions [centroid-centroid distances of 3.661(2) and 3.909(2)Å for (I), and 3.546(2)-3.725(4)Å for (II)], forming column structures. In (II), the base molecule is orientationally disordered over two sets of sites approximately around the N⋯N molecular axis, with an occupancy ratio of 0.647(4):0.353(4), and the average structure of the 2:1 unit adopts nearly pseudo-C 2 symmetry. Both compounds show liquid-crystal behaviour.

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  • Slow Stabilization of Si-Li Alloys Formed during Charge and Discharge Processes in a Si-Carbon Mixed Electrode Studied by in-situ Solid-State Li-7 Nuclear Magnetic Resonance Spectroscopy 査読

    J. Arai, K. Gotoh, R. Sayama, K. Takeda

    18TH INTERNATIONAL MEETING ON LITHIUM BATTERIES (IMLB 2016)   73 ( 1 )   141 - 151   2016年

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    記述言語:英語   掲載種別:研究論文(国際会議プロシーディングス)   出版者・発行元:ELECTROCHEMICAL SOC INC  

    The charge-discharge behavior of a Si-C (Si: graphite = 20: 80 wt%) mixed electrode was investigated by in-situ solid-state Li-7 nuclear magnetic resonance (NMR) spectroscopy. The spectra revealed the formation of Li-Si alloys and the intercalation of Li into graphite during the charge process and the corresponding reverse process (Li extraction) during discharge. Li was mainly stored as a Li-Si alloy (Li15Si4) at high SOC (State of Charge) values (above 80% SOC, low cell voltage region) and could be released from the same compound. The cell resistance measured by electrochemical impedance spectroscopy (EIS) increased steeply at high SOC values, revealing structural changes in the Li-Si alloy. The result is consistent with the gradual decrease of the Li15Si4 signal intensity in the NMR spectra observed immediately after a discharge process at 80% SOC.

    DOI: 10.1149/07301.0141ecst

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  • Combination of solid state NMR and DFT calculation to elucidate the state of sodium in hard carbon electrodes 査読

    Ryohei Morita, Kazuma Gotoh, Mika Fukunishi, Kei Kubota, Shinichi Komaba, Naoto Nishimura, Takashi Yumura, Kenzo Deguchi, Shinobu Ohki, Tadashi Shimizu, Hiroyuki Ishida

    JOURNAL OF MATERIALS CHEMISTRY A   4 ( 34 )   13183 - 13193   2016年

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:ROYAL SOC CHEMISTRY  

    We examined the state of sodium electrochemically inserted in HC prepared at 700-2000 degrees C using solid state Na magic angle spinning (MAS) NMR and multiple quantum (MQ) MAS NMR. The Na-23 MAS NMR spectra of Na-inserted HC samples showed signals only in the range between +30 and -60 ppm. Each observed spectrum was ascribed to combinations of Na+ ions from the electrolyte, reversible ionic Na components, irreversible Na components assigned to solid electrolyte interphase (SEI) or nonextractable sodium ions in HC, and decomposed Na compounds such as Na2CO3. No quasi-metallic sodium component was observed to be dissimilar to the case of Li inserted in HC. MQMAS NMR implies that heat treatment of HC higher than 1600 degrees C decreases defect sites in the carbon structure. To elucidate the difference in cluster formation between Na and Li in HC, the condensation mechanism and stability of Na and Li atoms on a carbon layer were also studied using DFT calculation. Na-3 triangle clusters standing perpendicular to the carbon surface were obtained as a stable structure of Na, whereas Li-2 linear and Li-4 square clusters, all with Li atoms being attached directly to the surface, were estimated by optimization. Models of Na and Li storage in HC, based on the calculated cluster structures were proposed, which elucidate why the adequate heat treatment temperature of HC for high-capacity sodium storage is higher than the temperature for lithium storage.

    DOI: 10.1039/c6ta04273b

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  • Arrangement and Dynamics of Diamine, Etheric, and Tetraalkylammonium Intercalates within Graphene or Graphite Oxide Galleries by H-2 NMR

    Kazuma Gotoh, Chika Sugimoto, Ryohei Morita, Tatsuya Miyatou, Motohiro Mizuno, Weekit Sirisaksoontorn, Michael M. Lerner, Hiroyuki Ishida

    JOURNAL OF PHYSICAL CHEMISTRY C   119 ( 21 )   11763 - 11770   2015年5月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:AMER CHEMICAL SOC  

    Ternary graphite intercalation compounds (GICs), which consist of graphite, alkali Metal (Li; Na, cations, and organic cointercalates such as ethylehediamine (en) or tetrahydrofuran (thf), are useful precursors to graphene-based materials and tetraalkylammonium GICs. This study investigates the gallery arrangements and intercalate dynamics of the deuterated en(d4), thf(d8), piperazine(d10), or 1,4-diazabicyclo[2.2.2]octane(dabco)(d12) in ternary GICs containing Na+ or K+ cations using XRD and solid state Na-23 and H-2 NMR line-shape analyses. An en(d4)-graphite oxide (GO) intercalation compound and the trihexylmethyl(d3)-ammonium (thma) GIC were also prepared and evaluated by XRD and NMR. The H-2 NMR spectra exhibit a narrow peak ascribed to intercalates undergoing isotropic rotation and a broad powder pattern ascribed to intercalates.in a rigid state or undergoing uniaxial rotations. The thma intercalates in thrna(d3)-GIC and the en(d4) intercalates in en(d4)-GO are relatively mobile and can diffuse; this may arise because there are no alkali metal cations in the galleries. The molecular dynamics as well as the synthetic challenges presented by some GICs are explained in terms of different affinities of alkali metal cations to the cointercalates.

    DOI: 10.1021/acs.jpcc.5b03016

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  • Crystal structures of isoquinoline-3-chloro-2-nitro-benzoic acid (1/1) and isoquinolinium 4-chloro-2-nitrobenzoate

    Kazuma Gotoh, Hiroyuki Ishida, A. J. Lough

    Acta Crystallographica Section E: Structure Reports Online   71 ( 1 )   31 - 34   2015年1月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:International Union of Crystallography  

    In each of the title isomeric compounds, C9H7.3N·C7H3.7ClNO4, (I), and C9H8N·C7H3ClNO4, (II), of isoquinoline with 3-chloro-2-nitrobenzoic acid and 4-chloro-2-nitrobenzoic acid, the two components are linked by a short hydrogen bond between a base N atom and a carboxy O atom. In the hydrogen-bonded unit of (I), the H atom is disordered over two positions with N and O site occupancies of 0.30 (3) and 0.70 (3), respectively, while in (II), an acid-base interaction involving H-atom transfer occurs and the H atom is located at the N site. In the crystal of (I), the acid-base units are connected through C - H⋯O hydrogen bonds into a tape structure along the b-axis direction. Inversion-related adjacent tapes are further linked through π-π interactions [centroid-centroid distances = 3.6389 (7)-3.7501 (7) Á], forming a layer parallel to (001). In the crystal of (II), the acid-base units are connected through C - H⋯O hydrogen bonds into a ladder structure along the a-axis direction. The ladders are further linked by another C - H⋯O hydrogen bond into a layer parallel to (001).

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  • Crystal structures of three co-crystals of 4,4'-bipyridyl with 4-alkoxybenzoic acids: 4-ethoxybenzoic acid 4,4'-bipyridyl (2/1), 4-n-propoxybenzoic acid–4,4'-bipyridyl (2/1) and 4-n-butoxybenzoic acid–4,4'-bipyridyl (2/1) 査読

    Yohei Tabuchi, Kazuma Gotoh, Hiroyuki Ishida

    Acta Cryst.   71   1290 - 1295   2015年

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    DOI: 10.1107/S2056989015018435

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  • Crystal structures of morpholinium hydrogen bromanilate at 130, 145 and 180K 査読

    Kazuma Gotoh, Yuki Tahara, Hiroyuki Ishida

    Acta Crystallographica Section E: Crystallographic Communications   71   1226 - 1229   2015年

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:International Union of Crystallography  

    Crystal structures of the title compound (systematic name: morpholin-4-ium 2,5-dibromo-4-hydroxy-3,6-dioxocyclohexa-1,4-dien-1-olate), C4H10NO+·C6HBr2O4 -, were determined at three temperatures, viz. 130, 145 and 180K. The asymmetric unit comprises one morpholinium cation and two halves of crystallographically independent bromanilate monoanions, which are located on inversion centres. The conformations of the two independent bromanilate anions are different from each other with respect to the O - H orientation. In the crystal, the two different anions are linked alternately into a chain along [211] through a short O - H⋯O hydrogen bond, in which the H atom is disordered over two positions. The refined site-occupancy ratios, which are almost constant in the temperature range studied, are 0.49(3):0.51(3), 0.52(3):0.48(3) and 0.50(3):0.50(3), respectively, at 130, 145 and 180K, and no significant difference in the molecular geometry and the molecular packing is observed at the three temperatures. The morpholinium cation links adjacent chains of anions via N - H⋯O hydrogen bonds, forming a sheet structure parallel to (-111).

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  • In Situ Solid State Li-7 NMR Observations of Lithium Metal Deposition during Overcharge in Lithium Ion Batteries

    J. Arai, Y. Okada, T. Sugiyama, M. Izuka, K. Gotoh, K. Takeda

    JOURNAL OF THE ELECTROCHEMICAL SOCIETY   162 ( 6 )   A952 - A958   2015年

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:ELECTROCHEMICAL SOC INC  

    Lithium metal deposition during overcharge in practical lithium ion cells composed of a lithium metal oxide (LiCoO2) positive electrode coated on Al foil, carbon (synthesized graphite and hard carbon) negative electrodes coated on Cu foil, polypropylene separator, and liquid electrolyte was observed using in situ solid state Li-7 nuclear magnetic resonance (NMR) measurements with an original probe featuring a flattened solenoid coil. Li insertion and extraction in carbon electrodes were monitored during charge and discharge and the intensities of certain peaks were found to be proportional to the cell capacity change. The deposition of metallic Li commenced after the cell voltage exceeded the nominal value and almost saturated after 160% of charge at a low current rate. The measurements showed that the deposition of metallic Li was much easier on graphite compared to hard carbon. The metallic Li deposited on hard carbon was almost completely discharged, whereas that on graphite remained after discharging to 2.5 V. (C) 2015 The Electrochemical Society. All rights reserved.

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  • Crystal structures of three co-crystals of 1,2-bis(pyridin-4-yl)ethane with 4-alkoxybenzoic acids: 4-ethoxybenzoic acid–1,2-bis(pyridin-4-yl)ethane (2/1), 4-n-propoxybenzoic acid–1,2-bis-(pyridin-4-yl)ethane (2/1) and 4-n-butoxybenzoic acid–1,2-bis(pyridi 査読

    Yohei Tabuchi, Kazuma Gotoh, Hiroyuki Ishida

    Acta Cryst.   71   1340 - 1343   2015年

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    DOI: 10.1107/S2056989015019349

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  • In situ Li-7 nuclear magnetic resonance study of the relaxation effect in practical lithium ion batteries

    Kazuma Gotoh, Misato Izuka, Juichi Arai, Yumika Okada, Teruyasu Sugiyama, Kazuyuki Takeda, Hiroyuki Ishida

    CARBON   79   380 - 387   2014年11月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:PERGAMON-ELSEVIER SCIENCE LTD  

    Lithium ion cells comprising actual components of positive electrodes (LiCoO2, LiNixCoyAlz, and LiMn2O4) and negative electrodes (graphite and hard carbon) were assembled for in situ Li-7 nuclear magnetic resonance (NMR) experiments. The Li-7 NMR measurements of the cells revealed a "relaxation effect" after overcharging: a decrease of the signal assigned to Li metal deposited on the negative electrode surface by overcharging. The reduction of the Li metal signal was inversely proportional to the increase of the signal of lithium stored in carbon. Therefore, the effect was ascribed to absorption of deposited lithium into the carbon of negative electrodes. The effect, which occurred rapidly in a few hours, reached an equilibrium state at 8-15 h. The slight shift of deposited metal suggests that dendritic Li easily re-dissolved, although larger Li particles remained. A hard carbon electrode has a greater effect of Li metal relaxation than graphite electrodes do, which is explainable by the bufferable structure of the carbon. Results are expected to be important for the discussion of the state of lithium, and for safer battery design. (C) 2014 Elsevier Ltd. All rights reserved.

    DOI: 10.1016/j.carbon.2014.07.080

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  • An Extended Phenacene-type Molecule, [8] Phenacene: Synthesis and Transistor Application

    Hideki Okamoto, Ritsuko Eguchi, Shino Hamao, Hidenori Goto, Kazuma Gotoh, Yusuke Sakai, Masanari Izumi, Yutaka Takaguchi, Shin Gohda, Yoshihiro Kubozono

    SCIENTIFIC REPORTS   4   5330   2014年6月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:NATURE PUBLISHING GROUP  

    A new phenacene-type molecule, [8] phenacene, which is an extended zigzag chain of coplanar fused benzene rings, has been synthesised for use in an organic field-effect transistor (FET). The molecule consists of a phenacene core of eight benzene rings, which has a lengthy pi-conjugated system. The structure was verified by elemental analysis, solid-state NMR, X-ray diffraction (XRD) pattern, absorption spectrum and photoelectron yield spectroscopy (PYS). This type of molecule is quite interesting, not only as pure chemistry but also for its potential electronics applications. Here we report the physical properties of [8] phenacene and its FET application. An [8] phenacene thin-film FET fabricated with an SiO2 gate dielectric showed clear p-channel characteristics. The highest m achieved in an [8] phenacene thin-film FET with an SiO2 gate dielectric is 1.74 cm(2) V-1 s(-1), demonstrating excellent FET characteristics; the average mu was evaluated as 1.2(3) cm(2) V-1 s(-1). The mu value in the [8] phenacene electric-double-layer FET reached 16.4 cm(2) V-1 s(-1), which is the highest reported in EDL FETs based on phenacene-type molecules; the average m was evaluated as 8(5) cm(2) V-1 s(-1). The mu values recorded in this study show that [8] phenacene is a promising molecule for transistor applications.

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  • NMRでみる炭素材料のリチウム吸蔵と ナトリウム吸蔵

    後藤 和馬, 石田 祐之

    炭素   263 ( 263 )   104 - 108   2014年

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    記述言語:日本語   出版者・発行元:THE CARBON SOCIETY OF JAPAN  

    Solid state nuclear magnetic resonance (NMR) is a powerful tool to characterize carbon materials. The state of lithium in the anode (negative electrode) of lithium ion batteries (LIBs) has been analyzed using 7Li NMR. A 23Na NMR study on sodium stored in the hard carbon anode of a sodium ion battery (SIB) was also made and compared with the result of 7Li NMR studies of LIB. Lithium forms quasimetallic clusters in the nanopores of hard carbon whereas sodium does not. Recent developments in in situ 7Li NMR research by some groups are also introduced. In situ NMR measurements of a LIB system can reveal the non-equilibrium state of the battery during charge and discharge.

    DOI: 10.7209/tanso.2014.104

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  • In situ Solid State Li-7 NMR Observation of Lithium Metal Deposition during Overcharge in Lithium Ion Battery

    J. Arai, Y. Okada, T. Sugiyama, M. Izuka, K. Gotoh, K. Takeda

    17TH INTERNATIONAL MEETING ON LITHIUM BATTERIES (IMLB 2014)   62 ( 1 )   159 - 187   2014年

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    記述言語:英語   掲載種別:研究論文(国際会議プロシーディングス)   出版者・発行元:ELECTROCHEMICAL SOC INC  

    Lithium metal deposition during overcharge in a full cell composed of lithium metal oxide (LiCoO2) positive electrodes and carbon negative electrodes (a synthesized graphite, a natural graphite and two types of hard carbon) was observed by in situ Li-7 solid state NMR (nuclear magnetic resonance). Peak intensities corresponding to the GIC (Graphite Intercalation Compound, charged state) and dendritic Li (deposited metallic Li) were monitored at each 20% state of charge (SOC) during discharge (and charge) and each 17 minutes (or 1000 scans) after the cell capacity reached the expected overcharge. The GIC peak increased with charge and decreased with discharge during the normal voltage of operation. The Li metal deposition occurred after the cell was charged above its normal operational voltage (4.2 V) though intercalation into the carbon still simultaneously occured, suggesting that metallic Li can be formed when the negative electrode reaches a voltage below 0 V vs. Li. We also found that the dendritic Li is not inert but active to be oxidized again and intercalated into the carbon within a few hours. The dendritic Li formed on hard carbon was completely discharged, while that deposited on graphite was not, indicating that the electrochemical property of the dendritic Li varies with the nature of the negative electrode.

    DOI: 10.1149/06201.0159ecst

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  • Bis(triethylammonium) chloranilate

    Kazuma Gotoh, Shinpei Maruyama, Hiroyuki Ishida

    Acta Crystallographica Section E: Structure Reports Online   69 ( 9 )   o1400   2013年9月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    In the crystal structure of the title compound [systematic name: bis(triethylammonium) 2,5-dichloro-3,6-dioxocyclohexa-1,4-diene-1,4-diolate], 2C6H16N+·C6Cl 2O4 2-, the chloranilate anion lies on an inversion center. The triethylammonium cations are linked on both sides of the anion via bifurcated N - H⋯(O,O) and weak C - H⋯O hydrogen bonds to give a centrosymmetric 2:1 aggregate. The 2:1 aggregates are further linked by C - H⋯O hydrogen bonds into a zigzag chain running along [01-1]. © 2013 Gotoh et al.

    DOI: 10.1107/S1600536813021405

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  • Bis(4-methoxy-3,4-dihydroquinazolin-1-ium) chloranilate

    Kazuma Gotoh, Hiroyuki Ishida

    Acta Crystallographica Section E: Structure Reports Online   69 ( 9 )   o1482   2013年9月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    In the title compound [systematic name: bis(4-methoxy-3,4- dihydroquinazolin-1-ium) 2,5-dichloro-3,6-dioxocyclohexa-1,4-diene-1,4-diolate], 2C9H11N2O+·C 6Cl2O4 2-, the chloranilate anion lies about an inversion center. The 4-methoxy-3,4-dihydroquinazolin-1-ium cations are linked on both sides of the anion via bifurcated N - H⋯(O,O) and weak C - H⋯O hydrogen bonds, giving a centrosymmetric 2:1 aggregate. The 2:1 aggregates are linked by another N - H⋯O hydrogen bond into a tape running along [1-10]. The tapes are further linked by a C - H⋯O hydrogen bond into a layer parallel to the ab plane. © 2013 Gotoh and Ishida et al.

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  • 金属ナノ粒子/クラスター/単原子分散炭素薄膜の作製 (特集 炭素材料開発と応用技術の新展開)

    後藤 和馬

    ケミカルエンジニヤリング   58 ( 9 )   698 - 702   2013年9月

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    記述言語:日本語   出版者・発行元:化学工業社  

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  • Synthesis, characterization, crystal structure and theoretical studies on 4-bromo-2-[(E)-6-methyl-2-pyridyliminomethyl]phenol 査読

    Aliakbar Dehno Khalaji, Hossein Mighani, Milad Kazemnejadi, Kazomu Gotoh, Hiroyuki Ishida, Karla Fejfarova, Michal Dusek

    Arabian Journal of Chemistry   10   S1808 - S1803   2013年8月

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    記述言語:英語  

    The Schiff base compound, 4-bromo-2-[(E)-6-methyl-2-pyridyliminomethyl]phenol, has been synthesized by a reaction of 5-bromosalicylaldehyde with 6-methyl-2-aminopyridine and characterized by elemental analyses, 1H-NMR spectroscopy and X-ray single-crystal diffraction. The title compound crystallizes in monoclinic system, space group P21/c, with a = 13.2721(12) Å, b = 4.5481(4) Ǻ, c = 19.972 (2) Ǻ, β = 96.653 (3)°, V = 1197.4 (2) Ǻ3 and Z = 4. The molecular geometry obtained from X-ray crystallography has been compared with that of the title compound in the ground state calculated by using the density function method (B3LYP) with 6/31G basis set. Calculated results show that DFT can well reproduce the structure of the title compound. The DFT results show that the molecule exists only in enol form. The molecular conformation of the title compound is stabilized by an intramolecular O1-H1·N1 hydrogen bond. © 2013.

    DOI: 10.1016/j.arabjc.2013.07.007

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  • NMR study for electrochemically inserted Na in hard carbon electrode of sodium ion battery

    Kazuma Gotoh, Toru Ishikawa, Saori Shimadzu, Naoaki Yabuuchi, Shinichi Komaba, Kazuyuki Takeda, Atsushi Goto, Kenzo Deguchi, Shinobu Ohki, Kenjiro Hashi, Tadashi Shimizu, Hiroyuki Ishida

    JOURNAL OF POWER SOURCES   225   137 - 140   2013年3月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:ELSEVIER SCIENCE BV  

    The state of sodium inserted in the hard carbon electrode of a sodium ion battery having practical cyclability was investigated using solid state Na-23 NMR. The spectra of carbon samples charged (reduced) above 50 mAh g(-1) showed clear three components. Two peaks at 9.9 ppm and 5.2 ppm were ascribed to reversible sodium stored between disordered graphene sheets in hard carbon because the shift of the peaks was invariable with changing strength of external magnetic field. One broad signal at about -9 to -16 ppm was assigned to sodium in heterogeneously distributed closed nanopores in hard carbon. Low temperature Na-23 static and magic angle spinning NMR spectra didn't split or shift whereas the spectral pattern of Li-7 NMR for lithium-inserted hard carbon changes depending on the temperature. This strongly suggests that the exchange of sodium atoms between different sites in hard carbon is slow. These studies show that sodium doesn't form quasi-metallic clusters in closed nanopores of hard carbon although sodium assembles at nanopores while the cell is electrochemically charged. (C) 2012 Elsevier B.V. All rights reserved.

    DOI: 10.1016/j.jpowsour.2012.10.025

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  • A triclinic polymorph of 4-cyano-pyridinium hydrogen chloranilate

    Kazuma Gotoh, Hiroyuki Ishida

    Acta Crystallographica Section E: Structure Reports Online   68 ( 10 )   o2830   2012年10月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    The asymmetric unit of the triclinic polymorph of the title compound (systematic name: 4-cyanopyridinium 2,5-dichloro-4-hydroxy-3,6-dioxocyclohexa-1, 4-dien-1-olate), C6H5N2+·-C 6HCl2O4-, consists of two crystallographically independent cation-anion units, in each of which the cation and the anion are linked by an N - H O hydrogen bond. In the units, the dihedral angles between the cation and anion rings are 78.43 (11) and 80.71 (11)°. In the crystal, each unit independently forms a chain through N - H···O and O - H···N hydrogen bonds
    one chain runs along the c axis while the other runs along [011]. Weak C - H···O, C - H···N and C - H···Cl interactions are observed between the chains.

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  • Arrangement and Dispersion of Rh and Pt Atoms on Graphene Oxide Sheets

    Kazuma Gotoh, Hideki Hashimoto, Ryo Kawai, Yuta Nishina, Eiji Fujii, Takahiro Ohkubo, Atsushi Itadani, Yasushige Kuroda, Hiroyuki Ishida

    CHEMISTRY LETTERS   41 ( 7 )   680 - 682   2012年7月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:CHEMICAL SOC JAPAN  

    Hybrid materials of ultimately minimized metal particles, namely, isolated atoms or subnano-sized particles, on thermally exfoliated graphene oxide sheets were produced using cation-exchanged highly oxidized graphite as a precursor. Rh atoms on graphene sheets arrange with a regular spacing of 0.50 or 0.45 nm and form square or rectangular grid patterns, whereas isolated Pt atoms disperse on graphene sheets randomly.

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  • Synthesis, characterization and crystal structures of new bidentate Schiff base ligand and its vanadium(IV) complex: The catalytic activity of vanadyl complex in epoxidation of alkenes

    Gholamhossein Grivani, Aliakbar Dehno Khalaji, Vida Tahmasebi, Kazuma Gotoh, Hiroyuki Ishida

    POLYHEDRON   31 ( 1 )   265 - 271   2012年1月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:PERGAMON-ELSEVIER SCIENCE LTD  

    The Schiff base ligand N-salicylidin-2-bromoethylimine (L) and its vanadium(IV) complex, VOL2 (1), were synthesized and characterized by using X-ray, CHN, H-1 NMR and FT-IR methods. X-ray analysis shows the Schiff base ligand L acts as a bidentate (O, N) chelating ligand and coordinates via imine nitrogen and phenolato oxygen atoms to the V(IV) center. The coordination geometry around the V(IV) center in 1 is approximately square pyramidal, as indicated by the unequal metal-ligand bond distances and angles, with the basal plane formed by the N2O2 donors of the two bidentate Schiff base ligands, the two phenolato O atoms and the two imine N atoms are in the trans position. The coordination sphere of the V(IV) is completed by one oxygen atom in apical position. In the Schiff base ligand, L, there are some classical intramolecular O1-H1 center dot center dot center dot N1 and non-classical intermolecular C9-H9b center dot center dot center dot O1 hydrogen bonds, while in 1, there are two non-classical intermolecular C7-H7 center dot center dot center dot O3 and C8-H8b center dot center dot center dot O3 hydrogen bonds. The catalytic activity of 1 in epoxidation of cyclooctene was investigated in different conditions to obtain optimum conditions. The effects of solvent, oxidant, catalyst concentration and alkene/oxidant ratio were studied and the results showed that in CCl4 in the presence of tert-butylhydroperoxide in 1:3 alkene/oxidant ratio, high epoxide yield was obtained. The epoxidation of alkenes was also carried out in optimized conditions that high catalytic activity and selectivity were obtained. (C) 2011 Elsevier Ltd. All rights reserved.

    DOI: 10.1016/j.poly.2011.09.011

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  • Temperature dependence of one-dimensional hydrogen bonding in morpholinium hydrogen chloranilate studied by Cl-35 nuclear quadrupole resonance and multi-temperature X-ray diffraction

    Yasuhiro Tobu, Ryuichi Ikeda, Taka-aki Nihei, Kazuma Gotoh, Hiroyuki Ishida, Tetsuo Asaji

    PHYSICAL CHEMISTRY CHEMICAL PHYSICS   14 ( 35 )   12347 - 12354   2012年

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:ROYAL SOC CHEMISTRY  

    The temperature dependence of Cl-35 NQR frequencies and the spin-lattice relaxation times T-1 has been measured in the wide temperature range of 4.2-420 K for morpholinium hydrogen chloranilate in which a one-dimensional O-H center dot center dot center dot O hydrogen-bonded molecular chain of hydrogen chloranilate ions is formed. An anomalous temperature dependence of the NQR frequencies was analyzed to deduce a drastic temperature variation of the electronic state of the hydrogen-bonded molecular chain. The hydrogen atom distribution in the O center dot center dot center dot H center dot center dot center dot O hydrogen bond is discussed from the results of NQR as well as multi-temperature X-ray diffraction. Above ca. 330 K, the T-1 showed a steep decrease with an activation energy of ca. 70 kJ mol(-1) and with an isotope ratio Cl-37 T-1/Cl-35 T-1 = 0.97 +/- 0.2. The orientational change of the z axis of electric field gradient tensor in conjunction with the hydrogen transfer between adjacent hydrogen chloranilate ions is suggested as a possible relaxation mechanism.

    DOI: 10.1039/c2cp41241a

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  • Recyclable Pd-graphene catalyst: mechanistic insights into heterogeneous and homogeneous catalysis

    Yuta Nishina, Junya Miyata, Ryo Kawai, Kazuma Gotoh

    RSC ADVANCES   2 ( 25 )   9380 - 9382   2012年

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:ROYAL SOC CHEMISTRY  

    Pd-graphene, a composite of Pd nanoparticles and exfoliated graphene, was used as a catalyst in organic reactions. In the Suzuki-Miyaura cross-coupling reaction, Pd-graphene showed high reusability without aggregation of Pd nanoparticles. The intermediates of the reaction in the liquid phase, Ph-Pd-Br and Ph-Pd-OH, were detected by ESI-MS.

    DOI: 10.1039/c2ra21185h

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  • 4-Chloro-2-nitrobenzoic acid-pyrazine (2/1)

    Kazuma Gotoh, Hiroyuki Ishida

    ACTA CRYSTALLOGRAPHICA SECTION E-STRUCTURE REPORTS ONLINE   67   O3222 - U1359   2011年12月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:WILEY-BLACKWELL  

    In the title co-crystal, 2C(7)H(4)ClNO(4)center dot C4H4N2, the pyrazine molecule is located on an inversion centre, so that the asymmetric unit consists of one molecule of 4-chloro-2-nitrobenzoic acid and a half-molecule of pyrazine. The components are connected by O-H center dot center dot center dot N and C-H center dot center dot center dot O hydrogen bonds, forming a 2:1 unit. In the hydrogen-bonded unit, the dihedral angle between the pyrazine ring and the benzene ring of the benzoic acid is 16.55 (4)degrees. The units are linked by intermolecular C-H center dot center dot center dot O hydrogen bonds, forming a sheet structure parallel to ((1) over bar 04). A C-H center dot center dot center dot O hydrogen-bond linkage is also observed between these sheets.

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  • Morpholinium hydrogen chloranilate methanol monosolvate

    Kazuma Gotoh, Yuki Tahara, Hiroyuki Ishida

    ACTA CRYSTALLOGRAPHICA SECTION E-STRUCTURE REPORTS ONLINE   67   O3335 - U1630   2011年12月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:WILEY-BLACKWELL  

    In the crystal structure of the title compound, C4H10NO+center dot C6HCl2O4-center dot CH4O, the components are held together by bifurcated O-H center dot center dot center dot(O,O), O-H center dot center dot center dot(O, Cl) and N-H center dot center dot center dot(O, O) hydrogen bonds into a centrosymmetric 2+2+2 aggregate. The aggregates are further connected by another bifurcated N-H center dot center dot center dot(O,O) hydrogen bond, forming a double-tape structure along the b axis. A weak C-H center dot center dot center dot O interaction is observed between the tapes.

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  • Hydrogen-bonded structures of the 1:1 and 1:2 compounds of chloranilic acid with pyrrolidin-2-one and piperidin-2-one

    Kazuma Gotoh, Hiroyuki Ishida

    ACTA CRYSTALLOGRAPHICA SECTION C-CRYSTAL STRUCTURE COMMUNICATIONS   67   O500 - O504   2011年12月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:WILEY-BLACKWELL  

    In the four compounds of chloranilic acid (2,5-dichloro-3,6-dihydroxycyclohexa-2,5-diene-1,4-dione) with pyrrolidin-2-one and piperidin-2-one, namely, chloranilic acid-pyrrolidin-2-one (1/1), C6H2Cl2O4 center dot C4H7NO, (I), chloranilic acid-pyrrolidin-2-one (1/2), C6H2Cl2O4 center dot 2C(4)H(7)NO, (II), chloranilic acid-piperidin-2-one (1/1), C6H2Cl2O4 center dot C5H9NO, (III), and chloranilic acid-piperidin-2-one (1/2), C6H2Cl2O4 center dot 2C(5)H(9)NO, (IV), the shortest interactions between the two components are O-H center dot center dot center dot O hydrogen bonds, which act as the primary intermolecular interaction in the crystal structures. In (II), (III) and (IV), the chloranilic acid molecules lie about inversion centres. For (III), this necessitates the presence of two independent acid molecules. In (I), there are two formula units in the asymmetric unit. The O center dot center dot center dot O distances are 2.4728 (11) and 2.4978 (11) angstrom in (I), 2.5845 (11) angstrom in (II), 2.6223 (11) and 2.5909 (10) angstrom in (III), and 2.4484 (10) angstrom in (IV). In the hydrogen bond of (IV), the H atom is disordered over two positions with site occupancies of 0.44 (3) and 0.56 (3). This indicates that proton transfer between the acid and base has partly taken place to form ion pairs. In (I) and (II), N-H center dot center dot center dot O hydrogen bonds, the secondary intermolecular interactions, connect the pyrrolidin-2-one molecules into a dimer, while in (III) and (IV) these hydrogen bonds link the acid and base to afford three-and two-dimensional hydrogen-bonded networks, respectively.

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  • Hydrogen-bonded structures of the isomeric compounds of phthalazine with 3-chloro-2-nitrobenzoic acid, 4-chloro-2-nitrobenzoic acid and 4-chloro-3-nitrobenzoic acid

    Kazuma Gotoh, Hiroyuki Ishida

    ACTA CRYSTALLOGRAPHICA SECTION C-CRYSTAL STRUCTURE COMMUNICATIONS   67   O473 - O478   2011年11月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:WILEY-BLACKWELL  

    The structures of three isomeric compounds, C7H4ClNO4 center dot C8H6N2, of phthalazine with chloro-and nitro-substituted benzoic acid, namely, 3-chloro-2-nitrobenzoic acid-phthalazine (1/1), (I), 4-chloro-2-nitrobenzoic acid-phthalazine (1/1), (II), and 4-chloro-3-nitrobenzoic acid-phthalazine (1/1), (III), have been determined at 190 K. In the asymmetric unit of each compound, there are two crystallographically independent chloronitrobenzoic acid-phthalazine units, in each of which the two components are held together by a short hydrogen bond between an N atom of the base and a carboxyl O atom. In one hydrogen-bonded unit of (I) and in two units of (II), a weak C-H center dot center dot center dot O interaction is also observed between the two components. The N center dot center dot center dot O distances are 2.5715 (15) and 2.5397 (17) angstrom for (I), 2.5655 (13) and 2.6081 (13) angstrom for (II), and 2.613 (2) and 2.589 (2) angstrom for (III). In both hydrogen-bonded units of (I) and (II), the H atoms are each disordered over two positions with (N site):(O site) occupancies of 0.35 (3): 0.65 (3) and 0.31 (3): 0.69 (3) for (I), and 0.32 (3): 0.68 (3) and 0.30 (3): 0.70 (3) for (II). The H atoms in the hydrogen-bonded units of (III) are located at the O-atom sites.

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  • 2-Chloro-4-nitrobenzoic acid-quinoline (1/1)

    Kazuma Gotoh, Hiroyuki Ishida

    ACTA CRYSTALLOGRAPHICA SECTION E-STRUCTURE REPORTS ONLINE   67   O2883 - +   2011年11月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:WILEY-BLACKWELL  

    In the title compound, C7H4ClNO4 center dot C9H7N, the two components are connected by an O-H center dot center dot center dot N hydrogen bond. In the hydrogen-bonded unit, the dihedral angle between the quinoline ring system and the benzene ring of benzoic acid is 3.15 (7)degrees. In the crystal, units are linked by intermolecular C-H center dot center dot center dot O hydrogen bonds, forming a tape along the c axis. The tapes are stacked along the b axis through a C-H center dot center dot center dot O hydrogen bond into a layer parallel to the bc plane.

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  • Synthesis of Ternary and Quaternary Graphite Intercalation Compounds Containing Alkali Metal Cations and Diamines

    Tosapol Maluangnont, Michael M. Lerner, Kazuma Gotoh

    INORGANIC CHEMISTRY   50 ( 22 )   11676 - 11682   2011年11月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:AMER CHEMICAL SOC  

    A series of ternary graphite intercalation compounds (GICs) of alkali metal cations (M = Li, Na, K) and diamines [EN (ethylenediamine), 12DAP (1,2-diaminopropane), and DMEDA (N,N-dimethylethylenecliarnine)] are reported. These include stage 1 and 2 M-EN-GIC (M = Li, d(i) = 0.68-0.84 nm; M = Na, d(i) = 0.68 nm), stage 2 Li-12DAP-GIC (d(i) = 0.83 nm), and stage 1 and 2 Li-DMEDA-GIC (d(i) = 0.91 nm), where d(i) is the gallery height. For M = Li, a perpendicular-to-parallel transition of EN is observed upon evacuation, whereas for M = Na, the EN remains in parallel orientation. Li-12DAP-GIC and Li-DMEDA-GIC contain chelated Li(+) and do not show the perpendicular-to-parallel transition. We also report the quaternary compounds of mixed cations (Li,Na)-12DAP-GIC and mixed amines Na-(EN,12DAP)-GIC, with d(i) values in both cases between those Of the ternary end members. (Li,Na)-12DAP-GIC is a solid solution with lattice dimensions dependent on composition, whereas for Na- (EN,12DAP)-GIC, the lattice dimension does not vary with amine content.

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  • Analysis of bis(trifluoromethylsulfonyl)imide-doped paramagnetic graphite intercalation compound using F-19 very fast magic angle spinning nuclear magnetic resonance

    Kazuma Gotoh, Kazuyuki Takeda, Michael M. Lerner, Yoshimi Sueishi, Shinpei Maruyama, Atsushi Goto, Masataka Tansho, Shinobu Ohki, Kenjiro Hashi, Tadashi Shimizu, Hiroyuki Ishida

    CARBON   49 ( 12 )   4064 - 4066   2011年10月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:PERGAMON-ELSEVIER SCIENCE LTD  

    F atoms bonding to paramagnetic/conductive graphene layers in accepter-type graphite intercalation compounds (GICs) are analyzed using very fast magic angle spinning nuclear magnetic resonance, which is applied for the first time on F-19 nuclei to investigate paramagnetic materials. In the bis(trifluoromethylsulfonyl)imide(TFSI)-doped GIC, C-F bonds between fluorine atoms and graphene layers conform to a weak bonding of F to the graphene sheets. TFSI anions intercalated in the GIC do not show overall molecular motion; even at room temperature only the CF3 groups rotate. (C) 2011 Elsevier Ltd. All rights reserved.

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  • One Dimensional Hydrogen Bonded Arrangement in New Schiff-Base Compound (E)-2-(2,5-dimethoxybenzylideneamino)phenol (1): Synthesis, Characterization, Crystal Structure and Conformational Studies

    Aliakbar Dehno Khalaji, Hossein Mighani, Hamid Reza Bijanzadeh, Kazuma Gotoh, Hiroyuki Ishida

    JOURNAL OF CHEMICAL CRYSTALLOGRAPHY   41 ( 10 )   1515 - 1519   2011年10月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:SPRINGER/PLENUM PUBLISHERS  

    New Schiff-base compound (E)-2-(2,5-dimethoxybenzylideneamino)phenol (1) was synthesized and characterized by elemental analyses, FT-IR and (1)H-NMR spectroscopy and single crystal X-ray diffraction. Molecular orbital calculation has been carried out for 1 by using HF method at 6-31G basis set. The title compound 1 crystallizes in monoclinic system, space group C2/c, with a = 19.4581(13) , b = 9.5805(5) C(0), c = 13.8431(7) C(0), beta = 93.471(2)A degrees, V = 2575.9(3) C(03) and Z = 8. In the crystal structure two molecules are stabilized by a pair of intermolecular O1-H1 center dot center dot center dot N1(i) hydrogen bonds. The dimeric units are further linked via C6-H6 center dot center dot center dot O3(ii) hydrogen bond.

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  • Electrochemical Na Insertion and Solid Electrolyte Interphase for Hard-Carbon Electrodes and Application to Na-Ion Batteries

    Shinichi Komaba, Wataru Murata, Toru Ishikawa, Naoaki Yabuuchi, Tomoaki Ozeki, Tetsuri Nakayama, Atsushi Ogata, Kazuma Gotoh, Kazuya Fujiwara

    ADVANCED FUNCTIONAL MATERIALS   21 ( 20 )   3859 - 3867   2011年10月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:WILEY-V C H VERLAG GMBH  

    Recently, lithium-ion batteries have been attracting more interest for use in automotive applications. Lithium resources are confirmed to be unevenly distributed in South America, and the cost of the lithium raw materials has roughly doubled from the first practical application in 1991 to the present and is increasing due to global demand for lithium-ion accumulators. Since the electrochemical equivalent and standard potential of sodium are the most advantageous after lithium, sodium based energy storage is of great interest to realize lithium-free high energy and high voltage batteries. However, to the best of our knowledge, there have been no successful reports on electrochemical sodium insertion materials for battery applications; the major challenge is the negative electrode and its passivation. In this study, we achieve high capacity and excellent reversibility sodium-insertion performance of hard-carbon and layered NaNi0.5Mn0.5O2 electrodes in propylene carbonate electrolyte solutions. The structural change and passivation for hard-carbon are investigated to study the reversible sodium insertion. The 3-volt secondary Na-ion battery possessing environmental and cost friendliness, Na+-shuttlecock hard-carbon/NaNi0.5Mn0.5O2 cell, demonstrates steady cycling performance as next generation secondary batteries and an alternative to Li-ion batteries.

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  • 2-[4-(2-Formylphenoxy)butoxy]benzaldehyde

    Aliakbar Dehno Khalaji, Salar Hafez Ghoran, Kazuma Gotoh, Hiroyuki Ishida

    ACTA CRYSTALLOGRAPHICA SECTION E-STRUCTURE REPORTS ONLINE   67   O2484 - U1637   2011年9月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:WILEY-BLACKWELL  

    In the crystal structure of the title compound, C18H18O4, the full molecule is generated by the application of an inversion centre. The molecule is essentially planar, with an r.m.s. deviation of 0.017 (1) angstrom for all non-H atoms. The molecules are linked through intermolecular C-H center dot center dot center dot O interactions to form a molecular sheet parallel to the ((1) over bar 02) plane.

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  • Synthesis, Characterization, Structure, Ab Initio and DFT Calculations of 2-Amino-N-(3-phenylprop-2-enylidene)aniline

    Aliakbar Dehno Khalaji, Hossein Mighani, Kazuma Gotoh, Hiroyuki Ishida

    JOURNAL OF CHEMICAL CRYSTALLOGRAPHY   41 ( 8 )   1154 - 1157   2011年8月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:SPRINGER/PLENUM PUBLISHERS  

    New Schiff base compound 2-amino-N-(3-phenylprop-2-enylidene)aniline, 1, was prepared by condensation of cinnamaldehyde with o-phenylenediamine and characterized by elemental analyses, UV-Vis and FT-IR spectroscopy. The crystal structure of 1 was determined by X-ray crystallography from single-crystal data and displays a trans configuration about the C=N double bond. In the crystal structure of 1, the molecule is located on an inversion center, so that it is disordered around the center of central C-C bond. The results from both the experimental and theoretical calculations are compared in this paper.

    DOI: 10.1007/s10870-011-0062-2

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  • Cobalt(III) Complex [CoL3] Derived from an Asymmetric Bidentate Schiff Base Ligand L (L=(5-Bromo-2-hydroxybenzyl-2-furylmethyl)-imine): Synthesis, Characterization and Crystal Structure

    Aliakbar D. Khalaji, Maghsodlou Sepideh Rad, Gholamhossein Grivani, Morteza Rezaei, Kazuma Gotoh, Hiroyuki Ishida

    CHINESE JOURNAL OF CHEMISTRY   29 ( 8 )   1613 - 1616   2011年8月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:WILEY-V C H VERLAG GMBH  

    Cobalt(III) complex [CoL3], where L=(5-bromo-2-hydroxybenzyl-2-furylmethyl)imine, has been synthesized by reacting cobalt(II) nitrate with L. The complex has been characterized by elemental analysis and FT-IR spectroscopy. The crystal structure of [CoL3] was determined by X-ray crystallography from single crystal data. It crystallizes in the triclinic space group P1 with unit cell parameters: a=9.6644(10) angstrom, b=11.5657(11) angstrom, c=16.5809(17) angstrom, alpha=102.833(4)degrees, beta=102.999(3)degrees, gamma=105.480(3)degrees, V=1659.9(3) angstrom(3) and Z=2. Thermal decomposition of [CoL3] was studied by thermogravimetry in order to evaluate its thermal stability and thermal decomposition pathways.

    DOI: 10.1002/cjoc.201180289

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  • Exfoliated graphene sheets decorated with metal/metal oxide nanoparticles: Simple preparation from cation exchanged graphite oxide

    Kazuma Gotoh, Taro Kinumoto, Eiji Fujii, Aki Yamamoto, Hideki Hashimoto, Takahiro Ohkubo, Atsushi Itadani, Yasushige Kuroda, Hiroyuki Ishida

    CARBON   49 ( 4 )   1118 - 1125   2011年4月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:PERGAMON-ELSEVIER SCIENCE LTD  

    We produced carbon hybrid materials of graphene sheets decorated with metal or metal oxide nanoparticles of gold, silver, copper, cobalt, or nickel from cation exchanged graphite oxide. Measurements using powder X-ray diffraction, transmission electron microscopy, and X-ray absorption spectra revealed that the Au and Ag in the materials (Au-Gr and Ag-Gr) existed on graphene sheets as metal nanoparticles, whereas Cu and Co in the materials (Cu-Gr and Co-Gr) existed as a metal oxide. Most Ni particles in Ni-Gr were metal, but the surfaces of large particles were partly oxidized, producing a core-shell structure. The Ag-Gr sample showed a catalytic activity for the oxygen reduction reaction in 1.0 M KOH aq. under an oxygen atmosphere. Ag-Gr is superior as a cathode in alkaline fuel cells, which should not be disturbed by the methanol cross-over problem from the anode. We established an effective approach to prepare a series of graphene-nanoparticle composite materials using heat treatment. (C) 2010 Elsevier Ltd. All rights reserved.

    DOI: 10.1016/j.carbon.2010.11.017

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  • Cation-directed orientation of amines in ternary graphite intercalation compounds

    Tosapol Maluangnont, Kazuma Gotoh, Kazuya Fujiwara, Michael M. Lerner

    CARBON   49 ( 3 )   1040 - 1042   2011年3月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:PERGAMON-ELSEVIER SCIENCE LTD  

    1,2-Diaminopropane (1,2-DAP) provides an unusual example of an organic co-intercalate where graphite intercalation compounds (GICs) show intra-gallery orientation dependant on the identity of the alkali metal cation intercalate (Li(+), Na(+), or K(+)). The GIC gallery heights, K(1,2-DAP)(y)C(x) = 0.697 nm and Li(1,2-DAP)(y)C(x) = 0.782 nm, indicate 1,2-DAP long axis orientations that are parallel or perpendicular to the graphene sheets, respectively. (C) 2010 Elsevier Ltd. All rights reserved.

    DOI: 10.1016/j.carbon.2010.10.052

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  • Rh-Catalyzed Carbonylation of Arylzinc Compounds Yielding Symmetrical Diaryl Ketones by the Assistance of Oxidizing Agents

    Kana Kobayashi, Yugo Nishimura, Fuxing Gao, Kazuma Gotoh, Yasushi Nishihara, Kentaro Takagi

    JOURNAL OF ORGANIC CHEMISTRY   76 ( 6 )   1949 - 1952   2011年3月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:AMER CHEMICAL SOC  

    Carbonylative homocoupling of arylzinc compounds 1 using 1 atm of CO and 1,2-dibromoethane as an oxidant was achieved in the presence of Rh-dppf catalyst, affording symmetrical diaryl ketones in good yields. Under similar conditions, Pd or Ni catalysts induced oxidative homo coupling of 1 to yield biaryls instead. The beneficial catalysis by Rh in the carbonylation was presumed to stem from the facility by which the migration of the aryl ligand to CO at the Rh3+ intermediate occurred.

    DOI: 10.1021/jo1025173

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  • Centrosymmetric Structures of Three Substituted Malonic Acids

    Jerry Joe Ebow Kingsley Harrison, Robert Kingsford-Adaboh, Syunsuke Ueda, Kazuma Gotoh, Hiroyuki Ishida

    JOURNAL OF CHEMICAL CRYSTALLOGRAPHY   41 ( 3 )   306 - 311   2011年3月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:SPRINGER/PLENUM PUBLISHERS  

    Crystal structures of 2-methylmalonic acid, 2-ethylmalonic acid and 2-phenylmalonic acid, which are derivatives of malonic acid and have found usefulness in diagnostics and biochemical evaluations as markers and organic synthesis, are reported. 2-Methylmalonic acid and 2-ethylmalonic acid both crystallize in triclinic P-1 space group with cell parameters of a = 5.1033(7), b = 5.4231(7), c = 10.0887(14) angstrom, alpha = 88.074(4), beta = 89.999(5) and gamma = 67.955(4)A degrees for 2-methylmalonic acid, and a = 5.2073(4), b = 7.2258(6), c = 8.5655(6) angstrom, alpha = 88.086(2), beta = 75.307(2) and gamma = 85.904(3)degrees for 2-ethylmalonic acid, 2-phenylmalonic acid on the other hand crystallizes in monoclinic P2(1)/c with cell parameters a = 8.6494(4), b = 5.48733(19), c = 17.1706(6)angstrom and beta = 90.1068(17)degrees. The observed topology of the hydrogen bonding network is to a large extent dictated by the symmetrical substitution pattern with an open arrangement of hydrogen bonds. Each of the C=O double bonds in both 2-methylmalonic acid and 2-ethylmalonic acid is translationally offset, forming planar centrosymmetric carboxy-dimers. Molecules related by centre of inversion in spite of the constraints imposed by substituents are linked by O-H center dot center dot center dot O hydrogen bonds. This results in the formation of parallel zig-zag chains running along the [101] direction. In 2-phenylmalonic acid, the zig-zag molecular residue is parallely stacked with successive catemers. These laterally displaced catemers are also coiled in a twofold twist on the screw axis (x, 1/2 + y, 1/2 - z) along the b-glide (x, 1/2 - y, 1/2 + z) when viewed along the (101) plane.

    DOI: 10.1007/s10870-010-9878-4

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  • Li, Xe核NMRによる炭素材料の内部分析

    後藤 和馬

    炭素 = Carbons   ( 246 )   11 - 15   2011年1月

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    記述言語:日本語   出版者・発行元:THE CARBON SOCIETY OF JAPAN  

    Closed pores in non-graphitazable carbon (hard carbon) are the reason for some unique properties for lithium intercalation. Our group investigated intercalated Li in hard carbon, which is used for the anode active material of lithium ion batteries for electric vehicles, using solid state 7Li NMR. The correlation between deposition of lithium clusters in the pores and the state of charge were elucidated. The growth of the porous structure of hard carbon was also investigated using 129Xe NMR porosimetry. Xe NMR could evaluate pores in hard carbon that were hard to investigate by adsorption isotherm measurement. A Li NMR study for a ternary graphite intercalation compound consisting of alkylamine and Li is also presented.

    DOI: 10.7209/tanso.2011.11

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    その他リンク: https://jlc.jst.go.jp/DN/JALC/00363466987?from=CiNii

  • Donor-type Graphite Intercalation Compounds Containing Alkali Metal Cations with Amines and Polyamines

    Tosapol Maluangnont, Kazuma Gotoh, Kazuya Fujiwara, Michael M. Lerner

    3RD INTERNATIONAL CONGRESS ON CERAMICS (ICC): NANO-CRYSTALS AND ADVANCED POWDER TECHNOLOGY   18   2011年

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    記述言語:英語   掲載種別:研究論文(国際会議プロシーディングス)   出版者・発行元:IOP PUBLISHING LTD  

    A rich chemistry of ternary graphite intercalation compounds (GICs) containing alkali metal cations and amines or polyamines has been developed recently in our labs. Monolayer and bilayer structures for a range of amines and polyamines, including hexylamine, 1,2-diaminopropane, and diethylenetriamine, have been prepared chemically as stage 1 or 2 GICs. While these and related intercalates have been studied in detail with other layered host structures, there have been few reported analogs in graphite chemistry. However, our recent results indicate that under appropriate synthetic conditions the intercalation of amines into graphite may be comparable to that of other layered hosts, and may lead to an alternate chemical route to graphenes. The synthetic strategies employed and the structural and compositional details of the graphite intercalation compounds recently obtained (from XRD, NMR and thermal analysis) will be described.

    DOI: 10.1088/1757-899X/18/6/062004

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  • A N-14 nuclear quadrupole resonance study of phase transitions and molecular dynamics in hydrogen bonded organic antiferroelectrics 55DMBP-H(2)ca and 1,5-NPD-H(2)ca

    Janez Seliger, Veselko Zagar, Tetsuo Asaji, Kazuma Gotoh, Hiroyuki Ishida

    PHYSICAL CHEMISTRY CHEMICAL PHYSICS   13 ( 20 )   9165 - 9172   2011年

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:ROYAL SOC CHEMISTRY  

    The temperature dependence of the N-14 NQR frequencies has been measured in antiferroelectric and paraelectric 55DMBP-H(2)ca and 1,5-NPD-H(2)ca. In both compounds we observe two non-equivalent nitrogen positions (N+-H center dot center dot center dot O- and N center dot center dot center dot H-O) in the antiferroelectric phase. The two nitrogen positions become equivalent (N center dot center dot center dot H center dot center dot center dot O) in the paraelectric phase. The critical exponent of the local antiferroelectric order parameter has been determined from the NQR data. The principal values of the quadrupole coupling tensor correlate in both compounds. The correlation diagrams clearly show how a proton migrates from the antiferroelectric position towards the paraelectric position in the bifurcated hydrogen bond on increasing the temperature. A slow motion has been observed in 55DMBP-H(2)ca by the H-1 and N-14 spin-lattice relaxation. An analysis of the spin-lattice relaxation data suggests a slow exchange between two non-planar conformations of the bipyridine molecule.

    DOI: 10.1039/c0cp02873h

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  • 4-Chlorobenzoic acid-quinoline (1/1)

    Kazuma Gotoh, Kaori Katagiri, Hiroyuki Ishida

    ACTA CRYSTALLOGRAPHICA SECTION E-STRUCTURE REPORTS ONLINE   66   O3190 - U826   2010年12月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:WILEY-BLACKWELL  

    In the title compound, C(7)H(5)ClO(2)center dot C(9)H(7)N, the 4-chlorobenzoic acid molecule is almost planar, with a dihedral angle of 2.9 (14)degrees between the carboxy group and the benzene ring. In the crystal, the two components are connected by an O-H center dot center dot center dot N hydrogen bond. In the hydrogen-bonded unit, the dihedral angle between the quinoline ring system and the benzene ring of the benzoic acid is 44.75 (4)degrees. The two components are further linked by intermolecular C-H center dot center dot center dot O hydrogen bonds, forming a layer parallel to the ab plane.

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  • Triethylammonium hydrogen chloranilate

    Kazuma Gotoh, Shinpei Maruyama, Hiroyuki Ishida

    ACTA CRYSTALLOGRAPHICA SECTION E-STRUCTURE REPORTS ONLINE   66   O3255 - U1403   2010年12月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:WILEY-BLACKWELL  

    In the crystal structure of the title compound (systematic name: triethylammonium 2,5-dichloro-4-hydroxy-3,6-dioxocyclohexa- 1,4-dien-1-olate), C(6)H(16)N(+)center dot C(6)HCl(2)O(4)(-), two hydrogen chloranilate anions are connected by a pair of bifurcated O-H center dot center dot center dot O hydrogen bonds into a dimeric unit. The triethylammonium cations are linked on both sides of the dimer via bifurcated N-H center dot center dot center dot O hydrogen bonds into a centrosymmetric 2:2 aggregate. The 2:2 aggregates are further linked by intermolecular C-H center dot center dot center dot O hydrogen bonds.

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  • Synthesis, spectroscopic characterization, crystal structures, and theoretical studies of (E)-2-(2,4-dimethoxybenzylidene)thiosemicarbazone and (E)-2-(2,5-dimethoxybenzylidene)thiosemicarbazone

    Aliakbar Dehno Khalaji, Gholamhossein Grivani, Samaneh Jalali Akerdi, Kazuma Gotoh, Hiroyuki Ishida, Hossein Mighani

    STRUCTURAL CHEMISTRY   21 ( 5 )   995 - 1003   2010年10月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:SPRINGER/PLENUM PUBLISHERS  

    Two thiosemicarbazones, (E)-2-(2,4-dimethoxybenzylidene)thiosemicarbazone (24-MBTSC (1)) and (E)-2-(2,5-dimethoxybenzylidene)thiosemicarbazone (25-MBTSC (2)), derived from 2,4-dimethoxybenzaldehyde and 2,5-dimethoxybenzaldehyde, respectively, with thiosemicarbazide have been synthesized and their structures were characterized by elemental analyses, FT-IR, (1)H NMR spectroscopy, and X-ray single-crystal diffraction analysis. Molecular orbital calculations have been carried out for 1 and 2 by using an ab initio method (HF) and also density functional method (B3LYP) at 6-31G basis set. Compound 1 crystallizes in the monoclinic system, space group P2(1)/c, with a = 8.1342(5) , b = 18.1406(10) , c = 8.2847(6) , beta = 109.7258(17)A degrees, V = 1150.75(12) (3), and Z = 4, whereas compound 2 crystallizes in the orthorhombic system, space group Pbca, with a = 11.0868(6) , b = 13.1332(6) , c = 15.9006(8) , V = 2315.2(2) (3), and Z = 8. The compounds 1 and 2 displays a trans-configuration about the C=N double bond.

    DOI: 10.1007/s11224-010-9637-3

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  • Direct Information on Structure and Energetic Features of Cu+-Xe Species Formed in MFI-Type Zeolite at Room Temperature

    Hiroe Torigoe, Toshinori Mori, Kazuhiko Fujie, Takahiro Ohkubo, Atsushi Itadani, Kazuma Gotoh, Hiroyuki Ishida, Hiroki Yamashita, Takashi Yumura, Hisayoshi Kobayashi, Yasushige Kuroda

    JOURNAL OF PHYSICAL CHEMISTRY LETTERS   1 ( 18 )   2642 - 2650   2010年9月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:AMER CHEMICAL SOC  

    The interacted species of Xe with metal ions that are stable at room temperature are not known and are a subject of interest for fundamental chemistry We have,experimentally found a new and stable Xe species, XeCu+, which was formed it room temperature in a copper ion exchanged MFI-type zeolite. The presence of a prominent interaction between Cu+ in MFI and Xe, which has a covalent nature, was for the first time evidenced from experimental in situ synchrotron X-ray absorption fine structure and heat of adsorption measurements; the Cu+-Xe bond length of 2.45 angstrom and the bonding energy of ca. 60 kJ mol(-1). The bonding nature between Xe and Cu+ in the MFI zeolite was discussed utilizing density functional theory; the observed significant stabilization comes from the d(Cu+ in MFI)-p(Xe) orbital interaction. These new findings may pave a new way to developing fundamental chemistry of Xe compounds.

    DOI: 10.1021/jz100838c

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  • Bis[(3-chlorobenzyl)ammonium] 2-phenylpropanedioate dihydrate

    Jerry Joe Ebow Kingsley Harrison, Robert Kingsford-Adaboh, Kazuma Gotoh, Hiroyuki Ishida

    ACTA CRYSTALLOGRAPHICA SECTION E-STRUCTURE REPORTS ONLINE   66   O2168 - U2512   2010年8月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:WILEY-BLACKWELL  

    In the asymmetric unit of the title compound, 2C(7)H(9)ClN+center dot C9H6O4 2-center dot 2H(2)O, there are two crystallographically independent cations, one dianion and two water molecules. The dihedral angle between the two carboxylate groups of the dianion is 78.1 (2)degrees. In the crystal, the components are held together by N-H...O, O-H...O and C-H...O hydrogen bonds, forming a layer parallel to the bc plane, with the hydrophilic and hydrophobic groups located in the inner and outer regions of the layers, respectively.

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  • Negishi Alkyl-Aryl Cross-Coupling Catalyzed by Rh: Efficiency of Novel Tripodal 3-Diphenylphosphino-2-(diphenylphosphino)methyl-2-methylpropyl Acetate Ligand

    Syogo Ejiri, Shunsuke Odo, Hideki Takahashi, Yugo Nishimura, Kazuma Gotoh, Yasushi Nishihara, Kentaro Takagi

    ORGANIC LETTERS   12 ( 8 )   1692 - 1695   2010年4月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:AMER CHEMICAL SOC  

    3-Diphenylphosphino-2-(diphenylphoshino)methyl-2-methylpropyl acetate acted as an efficient ligand for a Rh catalyst, achieving cross-coupling between arylzinc compounds bearing electron-withdrawing groups and alkyl electrophiles. The beneficial effect of the tripodal ligand and such aryl nucleophiles was discussed with regard to the specificity of the Rh catalysis.

    DOI: 10.1021/ol100210u

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  • Two solid phases of pyrimidin-1-ium hydrogen chloranilate monohydrate determined at 225 and 120 K

    Kazuma Gotoh, Tetsuo Asaji, Hiroyuki Ishida

    ACTA CRYSTALLOGRAPHICA SECTION C-CRYSTAL STRUCTURE COMMUNICATIONS   66   O114 - O118   2010年3月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:WILEY-BLACKWELL  

    The crystal structures of two solid phases of the title compound, C(4)H(5)N(2)(+)center dot C(6)HCl(2)O(4)(-)center dot H(2)O, have been determined at 225 and 120 K. In the high-temperature phase, stable above 198 K, the transition temperature of which has been determined by (35)Cl nuclear quadrupole resonance and differential thermal analysis measurements, the three components are held together by O-H center dot center dot center dot O, N center dot center dot center dot H center dot center dot center dot O, C-H center dot center dot center dot O and C-H center dot center dot center dot Cl hydrogen bonds, forming a centrosymmetric 2+2+2 aggregate. In the N center dot center dot center dot H center dot center dot center dot O hydrogen bond formed between the pyrimidin-1-ium cation and the water molecule, the H atom is disordered over two positions, resulting in two states, viz. pyrimidin-1-ium-water and pyrimidine-oxonium. In the low-temperature phase, the title compound crystallizes in the same monoclinic space group and has a similar molecular packing, but the 2+2+2 aggregate loses the centrosymmetry, resulting in a doubling of the unit cell and two crystallographically independent molecules for each component in the asymmetric unit. The H atom in one N center dot center dot center dot H center dot center dot center dot O hydrogen bond between the pyrimidin-1-ium cation and the water molecule is disordered, while the H atom in the other hydrogen bond is found to be ordered at the N-atom site with a long N-H distance [1.10(3) angstrom].

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  • 3-Hydroxypyridinium hydrogen chloranilate monohydrate

    Kazuma Gotoh, Hiroyuki Ishida

    ACTA CRYSTALLOGRAPHICA SECTION E-STRUCTURE REPORTS ONLINE   65   O3060 - U296   2009年12月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:WILEY-BLACKWELL  

    In the title salt hydrate, C(5)H(6)NO(+)center dot C(6)HCl(2)O(4)(-)center dot H(2)O, the three components are held together by O-H center dot center dot center dot O and N-H center dot center dot center dot O hydrogen bonds, as well as by C-H center dot center dot center dot O contacts, forming a double-tape structure along the c axis. Within each tape, the pyridinium ring and the chloranilate ring are almost coplanar, forming a dihedral angle of 2.35 (7)degrees.

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  • Pore Structure of Hard Carbon Made from Phenolic Resin Studied by Xe-129 NMR

    Kazuma Gotoh, Takahiro Ueda, Taro Eguchi, Koji Kawabata, Kenji Yamamoto, Yuki Murakami, Satoshi Hayakawa, Hiroyuki Ishida

    BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN   82 ( 10 )   1232 - 1239   2009年10月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:CHEMICAL SOC JAPAN  

    The pore structure of hard carbon samples made from two kinds of phenolic resins by heating between 1073 and 1473 K was investigated by Xe-129 NMR. The difference of porous structure of hard carbon samples by heat treatment temperature, which was difficult to analyze precisely by general gas adsorption methods, could be evaluated by XeNMR at an equilibrium state of xenon gas adsorption. Carbon samples produced by heating precursors under a 0.1 MPa xenon atmosphere showed stronger NMR signals than carbon heated at reduced pressure, despite their almost identical powder X-ray diffraction (XRD) patterns. Applying this method, the dependence of NMR spectra on heating temperature between 1073 and 1473 K was examined. A carbon sample consisting of smaller particles showed almost constant shift values at about 102 ppm, while the peak of another sample with larger particles shifted between 118 and 82 ppm depending on the heating temperature. Then, almost all entrances of each sample closed above 1273 K. Using NMR with the improved heat-treatment by xenon gas, we evaluated pores in hard carbon that were hard to access from the outer surface of the hard carbon.

    DOI: 10.1246/bcsj.82.1232

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  • Pyridine-3-carbonitrile-chloranilic acid-acetonitrile (2/1/2)

    Kazuma Gotoh, Hiroyuki Ishida

    ACTA CRYSTALLOGRAPHICA SECTION E-STRUCTURE REPORTS ONLINE   65   O2467 - +   2009年10月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:WILEY-BLACKWELL  

    In the crystal structure of the title compound, 2C(6)H(4)N(2 center dot)-C(6)H(2)Cl(2)O(4)center dot 2C(2)H(3)N, the two symmetry-related pyridine-3-carbonitrile molecules are linked to either side of a chloranilic acid (systematic name: 2,5-dichloro-3,6-dihydroxy-1,4-benzoquinone) molecule via intermolecular O-H center dot center dot center dot N hydrogen bonds, giving a centrosymmetric 2:1 unit. The dihedral angle between the pyridine ring and the chloranilic acid plane is 26.71 (6)degrees. In addition, the two acetonitrile molecules are linked to either side of the 2:1 unit through C-H center dot center dot center dot N hydrogen bonds, forming a 2:1:2 aggregate. These 2:1:2 aggregates are further linked by weak intermolecular C-H center dot center dot center dot N and C-H center dot center dot center dot O hydrogen bonds, forming a tape along the c axis.

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  • Hydrogen-bonded structures of the isomeric compounds of quinoline with 2-chloro-5-nitrobenzoic acid, 3-chloro-2-nitrobenzoic acid, 4-chloro-2-nitrobenzoic acid and 5-chloro-2-nitrobenzoic acid

    Kazuma Gotoh, Hiroyuki Ishida

    ACTA CRYSTALLOGRAPHICA SECTION C-CRYSTAL STRUCTURE COMMUNICATIONS   65   O534 - O538   2009年10月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:WILEY-BLACKWELL  

    The structures of four isomeric compounds, all C7H4Cl-NO4 center dot C9H7N, of quinoline with chloro- and nitro-substituted benzoic acid, namely, 2-chloro-5-nitrobenzoic acid-quinoline (1/1), (I), 3-chloro-2-nitrobenzoic acid-quinoline (1/1), (II), 4-chloro-2-nitrobenzoic acid-quinoline (1/1), (III), and 5-chloro-2-nitrobenzoic acid-quinoline (1/1), (IV), have been determined at 185 K. In each compound, a short hydrogen bond is observed between the pyridine N atom and a carboxyl O atom. The N center dot center dot center dot O distances are 2.6476 ( 13), 2.5610 ( 13), 2.5569 ( 12) and 2.5429 ( 12) angstrom for ( I), ( II), ( III) and ( IV), respectively. Although in ( I) the H atom in the hydrogen bond is located at the O site, in ( II), ( III) and ( IV) the H atom is disordered in the hydrogen bond over two positions with ( N site):( O site) occupancies of 0.39 ( 3): 0.61 ( 3), 0.47 ( 3): 0.53 ( 3) and 0.65 ( 3): 0.35 ( 3), respectively.

    DOI: 10.1107/S0108270109037688

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  • The use of graphite oxide to produce mesoporous carbon supporting Pt, Ru, or Pd nanoparticles

    Kazuma Gotoh, Koji Kawabata, Eiji Fujii, Kunimitsu Morishige, Taro Kinumoto, Yuki Miyazaki, Hiroyuki Ishida

    CARBON   47 ( 8 )   2120 - 2124   2009年7月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:PERGAMON-ELSEVIER SCIENCE LTD  

    Mesoporous carbon having platinum, ruthenium or palladium nanoparticles on exfoliated graphene sheets were produced from graphite oxide (GO) and metal complexes. The Pt included carbon was made by heating of the intercalation compound including tetraammineplatinum (II) chloride monohydrate. Samples having Ru or Pd are producible by heating in nitrogen gas atmosphere using hexaammineruthenium (III) chloride or tetraamminepalladium (II) chloride monohydrate instead of Pt complex. The particle sizes of platinum, ruthenium, and palladium were, respectively, 1-3, 1-2, and 3-7 nm. The platinum- or palladium-containing sample showed catalytic activity for oxygen reduction. (C) 2009 Elsevier Ltd. All rights reserved.

    DOI: 10.1016/j.carbon.2009.03.052

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  • Hydrogen-bonded structures of the isomeric 2-, 3-and 4-carbamoylpyridinium hydrogen chloranilates

    Kazuma Gotoh, Hirokazu Nagoshi, Hiroyuki Ishida

    ACTA CRYSTALLOGRAPHICA SECTION C-CRYSTAL STRUCTURE COMMUNICATIONS   65   O273 - O277   2009年6月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:WILEY-BLACKWELL  

    In the three isomeric salts, all C(6)H(7)N(2)O(+) center dot C(6)HCl(2)O(4)(-), of chloranilic acid (2,5-dichloro-3,6-dihydroxy-1,4-benzoquinone) with 2-, 3-and 4-carbamoylpyridine, namely, 2-carbamoylpyridinium hydrogen chloranilate (systematic name: 2-carbamoylpyridinium 2,5-dichloro-4-hydroxy-3,6-dioxocyclohexa-1,4-dienolate), (I), 3-carbamoylpyridinium hydrogen chloranilate, (II), and 4-carbamoylpyridinium hydrogen chloranilate, (III), acid-base interactions involving H-atom transfer are observed. The shortest interactions between the cation and the anion in (I) and (II) are pyridinium N-H center dot center dot center dot(O,O) bifurcated hydrogen bonds, which act as the primary intermolecular interaction in each crystal structure. In (III), an amide N-H center dot center dot center dot(O,O) bifurcated hydrogen bond, which is much weaker than the bifurcated hydrogen bonds in (I) and (II), connects the cation and the anion.

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  • 2-Carboxypyridinium hydrogen chloranilate (vol E61, pg o4215, 2005)

    Youhei Tabuchi, Akiko Takahashi, Kazuma Gotoh, Haruo Akashi, Hiroyuki Ishida

    ACTA CRYSTALLOGRAPHICA SECTION E-STRUCTURE REPORTS ONLINE   65   E11 - E11   2009年3月

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    記述言語:英語   出版者・発行元:WILEY-BLACKWELL PUBLISHING, INC  

    In the crystal structure of the title salt, C6H 6NO2 +·C6HCl 2O4 -, the pyridine ring and the mean plane of the hydrogen chloranilate anion form a dihedral angle of 77.40 (8)°. The ionic components are held together by N - H⋯O and O - H⋯O hydrogen bonds, forming a supra-molecular ladder. C - H⋯O inter-actions are also present.

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  • 2-Carboxypyridinium hydrogen chloranilate 査読

    Kazuma Gotoh, Hirokazu Nagoshi, Hiroyuki Ishida

    ACTA CRYSTALLOGRAPHICA SECTION E-STRUCTURE REPORTS ONLINE   65   O614 - U2642   2009年3月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:WILEY-BLACKWELL PUBLISHING, INC  

    In the crystal structure of the title salt, C(6)H(6)NO(2)(+)center dot C(6)HCl(2)O(4)(-), the pyridine ring and the mean plane of the hydrogen chloranilate anion form a dihedral angle of 77.40 (8)degrees. The ionic components are held together by N-H center dot center dot center dot O and O-H center dot center dot center dot O hydrogen bonds, forming a supramolecular ladder. C-H center dot center dot center dot O interactions are also present.

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  • 4-Bromo-N-(3,4,5-trimethoxybenzylidene)aniline

    Aliakbar Dehno Khalaji, Matthias Weil, Kazuma Gotoh, Hiroyuki Ishida

    ACTA CRYSTALLOGRAPHICA SECTION E-STRUCTURE REPORTS ONLINE   65   O436 - U3134   2009年2月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:WILEY-BLACKWELL PUBLISHING, INC  

    The title compound, C(16)H(16)BrNO(3), adopts an E configuration with respect to the imine C=N bond. The two benzene rings are twisted with respect to each other at an angle of 38.3 (1)degrees. In the crystal structure, molecules are connected by weak bifurcated C-H center dot center dot center dot(O,O) hydrogen bonds, forming a helical chain along the b axis.

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  • Catena-poly[[[N,N′-bis-(3-methoxy-benzyl-idene)ethyl-enediamine] copper(I)]-μ-thio-cyanato-k2 N:S]

    Aliakbar Dehno Khalaji, Hassan Hadadzadeh, Kazuma Gotoh, Hiroyuki Ishida

    Acta Crystallographica Section E: Structure Reports Online   65   M70 - U753   2009年1月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    In the cyrstal structure of the title compound, [Cu(NCS)(C18H20N2O2)] n , the CuI atom is coordinated in a distorted tetra-hedral geometry by two imino N atoms from a bidentate chelating Schiff base ligand, and one N and one S atoms from two thio-cyanate anions. The thio-cyanate anion bridges the CuI atoms, forming a zigzag chain along [101]. The Schiff base ligand adopts an E,E configuration and the dihedral angle between the terminal benzene rings is 53.68 (8)°.

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  • Hydrogen bonding in 1,2-diazine–chloranilic acid (2 : 1) studied by a 14N nuclear quadrupole coupling tensor and multi-temperature X-ray diffraction

    Janez Seliger, Veselko Zagar, Kazuma Gotoh, Hiroyuki Ishida, Akiko Konnai, Daiki Aminoe, Tetsuo Asaji

    Phys. Chem. Chem. Phys.   11 ( 13 )   2281 - 2286   2009年

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    DOI: 10.1039/b818318j

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  • Hydrogen bonding in 1,2-diazine-chloranilic acid (2:1) studied by a N-14 nuclear quadrupole coupling tensor and multi-temperature X-ray diffraction

    Janez Seliger, Veselko Zagar, Kazuma Gotoh, Hiroyuki Ishida, Akiko Konnai, Daiki Amino, Tetsuo Asaji

    PHYSICAL CHEMISTRY CHEMICAL PHYSICS   11 ( 13 )   2281 - 2286   2009年

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:ROYAL SOC CHEMISTRY  

    Protons involved in the H-bond system in 1,2-diazine-chloranilic acid (2 : 1) are assumed to be in jumping motion in the double-minimum potential corresponding to the two extreme electronic states of O-H center dot center dot center dot N and O-center dot center dot center dot H-N+. N-14 nuclear quadrupole coupling constants were determined by H-1-N-14 nuclear quadrupole double resonance. Assuming that the observed coupling constants are result of a fast exchange of the two extreme electronic states, the coupling constants for each state were estimated by use of the equilibrium populations of the two extreme states determined from multi-temperature X-ray single-crystal diffraction. It was suggested that not only the population but also the electron distribution of the extreme electronic states itself changes with temperature.

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  • Erratum: 2-Carboxy-pyridinium hydrogen chloranilate (Acta Crystallographica Section E: Structure Reports Online (2005) E61 (o4215-o4217))

    Youhei Tabuchi, Akiko Takahashi, Kazuma Gotoh, Haruo Akashi, Hiroyuki Ishida

    Acta Crystallographica Section E: Structure Reports Online   65 ( 3 )   e11   2009年

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    DOI: 10.1107/S1600536809004528

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  • A novel hard-carbon optimized to large-size lithium-ion secondary batteries 査読

    Aisaku Nagai, Kazuhiko Shimizu, Mariko Maeda, Kazuma Gotoh

    Lithium-Ion Batteries: Science and Technologies   427 - 433   2009年

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    記述言語:英語   掲載種別:論文集(書籍)内論文   出版者・発行元:Springer New York  

    Kureha Corporation has developed nongraphitizable carbons (so-called hard carbon) prepared from the cross-linked petroleum pitch for almost 20 years as an anode of the lithium-ion battery (LIB).1 However, in these years graphite is more popularly used as an anode of LIB of small portable equipment, such as cellular phones, digital cameras, and portable personal computers, because high-energy density is much more important in this type of application than long-life durability is. Hard carbon has been used only in the field of professional camcorders, satellites, and electric bikes because it seemed to be difficult to change a new battery at the end of its life. Recently application to large-size equipments, such as electric tools and hybrid electric vehicles (HEV), gets a lot of attention. The operating voltage window of the battery for HEV should be wide enough to regenerate electric power at a high rate. However, the operating voltage of the battery in which graphite is used as an anode and LiCoO2 as a cathode is too flat and narrow, and the voltage will be immediately cramped to avoid overcharge at more than 4.3V. On the other hand, the operating window of the battery that used hard carbon is wider
    it is already evident that the battery that used hard carbon has a much higher input as well as output power at any state of charge than the battery that used graphite. This is the reason why so much of attention is focused on hard carbon.2 But the hard carbon that has been developed, Carbotron P (F), is designed for small-size equipment.3 It has a large charge capacity of more than 500Ahkg-1 and long-life durability. In order to improve response, particle size must be small enough to reduce the diffusion path of the lithium ion into carbons. So, there is another type of hard carbon for HEV that is named Carbotron PS (F). The basic electrochemical characteristics of Carbotron P (F) and Carbotron PS (F) are almost the same. However, these hard carbons have low charge-discharge efficiency and these capacities will fade when they are stored in the air before preparation. So, these hard carbons should be redesigned for HEV application. © 2009 Springer Science+Business Media, LLC.

    DOI: 10.1007/978-0-387-34445-4_22

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  • 3,4,5-Trimethoxybenzohydrazidium chloride

    Aamer Saeed, Amara Mumtaz, Hummera Rafique, Kazuma Gotoh, Hiroyuki Ishida

    ACTA CRYSTALLOGRAPHICA SECTION E-STRUCTURE REPORTS ONLINE   64   O2336 - U2324   2008年12月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:WILEY-BLACKWELL PUBLISHING, INC  

    The title compound, C(10)H(15)N(2)O(4)(+)center dot Cl(-), was obtained as an unexpected by-product during the synthesis of 1-[2-(substituted aryl)]-3-methylpyrazol-5-ones. The hydrazide group is essentially planar, with an r.s.m. deviation of 0.020 (2) angstrom, and is oriented at a dihedral angle of 30.52 (3)degrees with respect to the benzene ring. In the crystal structure, the cations and anions are linked through N-H center dot center dot center dot O and N-H center dot center dot center dot Cl hydrogen bonds, forming a molecular tape running along the b axis.

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  • 1,2-Diazinium hydrogen chloranilate

    Kazuma Gotoh, Hiroyuki Ishida

    ACTA CRYSTALLOGRAPHICA SECTION E-STRUCTURE REPORTS ONLINE   64   O2095 - U1719   2008年11月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:WILEY-BLACKWELL PUBLISHING, INC  

    In the crystal structure of the title compound, C(4)H(5)N(2)(+)center dot C(6)HCl(2)O(4)(-), there are three crystallographically independent 1,2-diazinium cations and hydrogen chloranilate anions. The anions are held together by pairs of O-H center dot center dot center dot O hydrogen bonds to form two types of dimers, one of which is centrosymmetric. The 1,2-diazinium cations are linked on both sides of each dimer via bifurcated N-H center dot center dot center dot O hydrogen bonds to give two kinds of 2-2 cation-anion associations. The 2-2 associations are linked by intermolecular C-H center dot center dot center dot O and C-H center dot center dot center dot N hydrogen bonds, forming a molecular tape along the [230] direction. The tapes are further connected by C-H center dot center dot center dot O hydrogen bonds, forming a three-dimensional network.

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  • Hydrogen bonding in 1,2-diazine-chloranilic acid (2/1) and 1,4-diazine-chloranilic acid (2/1) determined at 110 K 査読

    Kazuma Gotoh, Tetsuo Asaji, Hiroyuki Ishida

    ACTA CRYSTALLOGRAPHICA SECTION C-STRUCTURAL CHEMISTRY   64   O550 - O553   2008年10月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:INT UNION CRYSTALLOGRAPHY  

    The crystal structures of the isomeric title compounds [systematic names: pyridazine-2,5-dichloro-3,6-dihydroxy-p-benzoquinone (2/1), (I), and pyrazine-2,5-dichloro-3,6-dihydroxy-p-benzoquinone (2/1), (II)], 2C(4)H(4)N(2)center dot C6H2Cl2O4, have been redetermined at 110 K. The H atom in the intermolecular O center dot center dot center dot H center dot center dot center dot N hydrogen bond in each compound was revealed to be disordered; the relative occupancies at the O and N sites are 0.33 (3) and 0.67 (3), respectively, for (I), and 0.56 (4) and 0.44 (4) for (II). The formal charges of the chloranilic acid in (I) and (II) estimated from the occupancy factors are ca - 1.3 and -0.8, respectively. The geometries of the centrosymmetric chloranilic acid molecule in (I) and (II) are compared with the neutral, monoanionic and dianionic forms of chloranilic acid optimized by density functional theory (DFT) at the B3LYP/6-311+G(3df,2p) level. The result implies that the chloranilic acid molecule in ( I) is close to the monoanionic state, while that in (II) is between neutral and monoanionic, consistent with the result derived from the H-atom occupancies.

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  • Observation of micropores in hard-carbon using Xe-129 NMR porosimetry

    Kazuma Gotoh, Takahiro Ueda, Hironori Omi, Taro Eguchi, Mariko Maeda, Michihisa Miyahara, Aisaku Nagai, Hiroyuki Ishida

    JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS   69 ( 1 )   147 - 152   2008年1月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:PERGAMON-ELSEVIER SCIENCE LTD  

    The existence of micropores and the change of surface structure in pitch-based hard-carbon in xenon atmosphere were demonstrated using Xe-129 NMR. For high-pressure (4.0 MPa) Xe-129 NMR measurements, the hard-carbon samples in Xe gas showed three peaks at 27, 34 and 210 ppm. The last was attributed to the xenon in micropores (<1 nm) in hard-carbon particles. The NMR spectrum of a sample evacuated at 773 K and exposed to 0.1 MPa Xe gas at 773 K for 24 h showed two peaks at 29 and 128 ppm, which were attributed, respectively, to the xenon atoms adsorbed in the large pores (probably mesopores) and micropores of hard-carbon. With increasing annealing time in Xe gas at 773 K, both peaks shifted and merged into one peak at 50 ppm. The diffusion of adsorbed xenon atoms is very slow, probably because the transfer of molecules or atoms among micropores in hard-carbon does not occur readily. Many micropores are isolated from the outer surface. For that reason, xenon atoms are thought to be adsorbed only by micropores near the surface, which are easily accessible from the surrounding space. (C) 2007 Elsevier Ltd. All rights reserved.

    DOI: 10.1016/j.jpcs.2007.08.010

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  • Hydrogen bonding in 1,2-diazine-chloranilic acid (2/1) and 1,4-diazine-chloranilic acid (2/1) determined at 110 K

    Kazuma Gotoh, Tetsuo Asaji, Hiroyuki Ishida

    Acta Crystallographica Section C: Crystal Structure Communications   64 ( 10 )   o550 - o553   2008年

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    The crystal structures of the isomeric title compounds [systematic names: pyridazine-2,5-dichloro-3,6-dihydr-oxy-p-benzoquinone (2/1), (I), and pyrazine-2,5-dichloro-3,6-dihy-droxy-p-benzoquinone (2/1), (II)], 2C 4H4N2·C6H2Cl 2O4, have been re-determined at 110 K. The H atom in the inter-molecular O⋯H⋯N hydrogen bond in each compound was revealed to be disordered
    the relative occupancies at the O and N sites are 0.33 (3) and 0.67 (3), respectively, for (I), and 0.56 (4) and 0.44 (4) for (II). The formal charges of the chloranilic acid in (I) and (II) estimated from the occupancy factors are ca -1.3 and -0.8, respectively. The geometries of the centrosymmetric chloranilic acid molecule in (I) and (II) are compared with the neutral, monoanionic and dianionic forms of chloranilic acid optimized by density functional theory (DFT) at the B3LYP/6-311+G(3df,2p) level. The result implies that the chloranilic acid molecule in (I) is close to the monoanionic state, while that in (II) is between neutral and monoanionic, consistent with the result derived from the H-atom occupancies. © 2008 International Union of Crystallography.

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  • [(Z)-2-(3-Methyl-1,2,4-oxdiazol-5-yl)-2-(1-naphthyl)ethenylamino] formaldehyde oxime 1,4-dioxane hemisolvate

    Kensuke Okuda, Hiromi Watanabe, Takashi Hirota, Kazuma Gotoh, Hiroyuki Ishida

    Acta Crystallographica Section E: Structure Reports Online   63 ( 11 )   o4261 - o4262   2007年10月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    In the asymmetric unit of the title compound, C16H14N4O2·0.5C4H8O2, there are two crystallographically independent oxime mol-ecules and one solvent mol-ecule. Each oxime mol-ecule has intra-molecular N - H⋯O and N - H⋯N hydrogen bonds, which make the non-H atoms approximately coplanar except for the naphthyl groups. The two independent mol-ecules are connected to each other by O - H⋯N hydrogen bonds, forming a dimer. Dimers are linked into a layer through C - H⋯O, C - H⋯N and C - H⋯π inter-actions. There is π-stacking of approximately parallel oxadiazole rings, with a centroid-centroid distance of 3.6234 (9) Å and a dihedral angle of 8.90 (6)°. Dioxane C and H atoms are disordered over two sites each, with occupancy factors of ca 0.78:0.22. © International Union of Crystallography 2007.

    DOI: 10.1107/S1600536807048301

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  • Phase transition and temperature dependent electronic state of an organic ferroelectric, phenazine–chloranilic acid (1:1)

    T. Asaji, J. Seliger, V. Žagar, M. Sekiguchi, J. Watanabe, K. Gotoh, H. Ishida, S. Vrtnik, J. Dolinšek

    J. Phys., Condens. Matter   19 ( 22 )   2007年6月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    The isotope effect of hydrogen motion in an organic ferroelectric, phenazine (Phz)-chloranilic acid (H2ca and D2ca for normal and deuterated compounds, respectively) co-crystal, was studied by 35Cl nuclear quadrupole resonance (NQR). Besides a ferroelectric transition at Tc ≤ 253K (303K), a neutral-to-ionic transition was found below 170K (200K) for Phz-H2ca (Phz-D2ca). 1H-14N nuclear quadrupole double resonance measurements were also made in order to study the temperature dependent electronic state of Phz-(H/D)2ca. 14N NQR parameters suggested that donor orbital populations of the two nitrogen atoms in a phenazine molecule become nonequivalent (1.78 and 1.97) in the ferroelectric phase, while they are both equal to 1.89 in the paraelectric phase. In the ionic phase of Phz-D 2ca, which was obtained by cooling below 188K, they became 1.50 and 1.95, suggesting a proton transfer from D2ca toPhz. © IOP Publishing Ltd.

    DOI: 10.1088/0953-8984/19/22/226203

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  • Poly[(μ4-chloranilato)bis-(saccharin)disodium(I)]

    Moamen S. Refat, Hassan A. Hashem, Kazuma Gotoh, Hiroyuki Ishida

    Acta Crystallographica Section E: Structure Reports Online   63   M1383 - U130   2007年5月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    In the title compound {systematic name: poly[(4-2,5-dichloro-3,6-dihydr- oxy-1,4-benzoquinona-to)bis-[1,2-benzisothia-zol-3(2H)-one 1,1-dioxide] disodium(I)]}, [Na2(C6Cl2O4)(C7H5NO3S)2] n , the NaI atom is coordinated by six O atoms from three chloranilate ions and two saccharin ligands in a distorted octa-hedral geometry. There is an intra-molecular N - H⋯O hydrogen bond between the saccharin ligand and the chloranilate dianion. Each O atom of the chloranilate ion bonds to two NaI atoms, while the saccharin ligand bridges the NaI atoms via the carbonyl O atom and one of the sulfonyl O atoms. The Na atoms and bridging ligands form layers parallel to the ab plane at z = 0 and z = . The shortest Na⋯Na and Na⋯Cl distances in the layer are 3.6006 (12) and 3.0680 (7) Å, respectively. © 2007 International Union of Crystallography. All rights reserved.

    DOI: 10.1107/S1600536807016728

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  • Cl-35 NQR study of lattice dynamic and magnetic property of a crystalline coordination polymer {CuCA(phz)(H2O)(2)}(n)

    Kazuma Gotoh, Takeshi Terao, Tetsuo Asaji

    JOURNAL OF MOLECULAR STRUCTURE   826 ( 1 )   1 - 5   2007年1月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:ELSEVIER SCIENCE BV  

    Copper(II) compounds {CuCA(phz)(H2O)(2)}(n) (H(2)CA = chloranilic acid, phz = phenazine) having a layer structure of -CuCA(H2O)(2)-polymer chains and phenazine were studied by Cl-35 nuclear quadrupole resonance (NQR). The single NQR line observed at 35.635 MHz at 261.5 K increased to 35.918 MHz at 4.2 K. The degree of reduction of electric field gradient due to lattice vibrations was similar to that of chloranilic acid crystal. Temperature dependence of spin-lattice relaxation time, T-1, of the Cl-35 NQR signal below 20 K, between 20 and 210 K. and above 210 K. was explained by (1) a decrease of effective electron-spin density caused by antiferromagnetic interaction, (2) a magnetic interaction between Cl nuclear-spin and electron-spins on paramagnetic Cu(II) ions, and (3) an increasing contribution from reorientation of ligand molecules, respectively. The electron spin-exchange parameter vertical bar J vertical bar between the neighboring Cu(II) electrons was estimated to be 0.33 cm(-1) from the T-1 value of the range 20-210 K. Comparing this value with that of J = -1.84 cm(-1) estimated from the magnetic susceptibility, it is suggested that the magnetic dipolar coupling with the electron spins on Cu(II) ions must be the principal mechanism for the Cl-35 NQR spin-lattice relaxation of {CuCA(phz)(H2O)(2)}(n) but a delocalization of electron spin over the chloranilate ligand has to be taken into account. (c) 2006 Elsevier B.V. All rights reserved.

    DOI: 10.1016/j.moistruc.2006.04.022

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  • Hydrogen bonding in two solid phases of phenazine-chloranilic acid (1/1) determined at 170 and 93 K

    Kazuma Gotoh, Tetsuo Asaji, Hiroyuki Ishida

    ACTA CRYSTALLOGRAPHICA SECTION C-CRYSTAL STRUCTURE COMMUNICATIONS   63   O17 - O20   2007年1月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:BLACKWELL PUBLISHING  

    The crystal structures in two solid phases, i.e. phase II stable between 146 and 253 K and phase IV below 136 K, of the title compound [phenazine-chloranilic acid (1/1), C12H8N2 center dot C6H2Cl2O4, in phase II, and phenazinium hydrogen chloranilate, C12H9N2+center dot C6HCl2O4-, in phase IV], have been determined. Both phases crystallize in P2(1), and each structure was refined as an inversion twin. In phase II, the phenazine and chloranilic acid molecules are arranged alternately through two kinds of O-H center dot center dot center dot N hydrogen bonds. In phase IV, salt formation occurs by donation of one H atom from the chloranilic acid molecule to the phenazine molecule; the resulting monocation and monoanion are linked by N-H center dot center dot center dot O and O-H center dot center dot center dot N hydrogen bonds.

    DOI: 10.1107/S0108270106049468

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  • Properties of a novel hard-carbon optimized to large size Li ion secondary battery studied by Li-7 NMR

    Kazuma Gotoh, Mariko Maeda, Aisaku Nagai, Atsushi Goto, Masataka Tansho, Kenjiro Hashi, Tadashi Shimizu, Hiroyuki Ishida

    JOURNAL OF POWER SOURCES   162 ( 2 )   1322 - 1328   2006年11月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:ELSEVIER SCIENCE BV  

    The state of lithium in a novel hard-carbon optimized to the anode of large size Li ion secondary battery, which has been recently commercialized, was investigated and compared with other existing hard-carbon samples by Li-7 NMR method. The new carbon material showed a peak at 85 ppm with a shoulder signal at 7 ppm at room temperature in static NMR spectrum, and the former shifted to 210 ppm at 180 K. The latter at room temperature was attributed to Li doped in small particles contained in the sample. The new carbon sample showed weaker intensity of cluster-lithium signal than the other hard-carbon samples in NMR, which corresponded to a tendency of less "constant voltage" (CV) capacity in charge-discharge curves of electrochemical evaluation. Smaller CV capacity and initial irreversible capacity, which are the features of the novel hard-carbon, are considered to correspond to a blockade of the diffusion of Li into pore of carbon. (c) 2006 Elsevier B.V. All rights reserved.

    DOI: 10.1016/j.jpowsour.2006.09.001

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  • Cl-35 NQR of an organic ferroelectric phenazine chloranilic acid co-crystal

    Tetsuo Asaji, Kazuma Gotoh, Jun Watanabe

    JOURNAL OF MOLECULAR STRUCTURE   791 ( 1-3 )   89 - 92   2006年6月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:ELSEVIER SCIENCE BV  

    A ferroelectric transition of phenazine (Phz) chloranilic acid (H(2)ca) co-crystal was studied by Cl-35 nuclear quadrupole resonance (NQR). The single NQR line observed at 36.689 MHz at 295 K, split into a doublet below the ferroelectric transition temperature T-c = 253 K in accord with the inversion-symmetry breaking at the H2ca molecular center in the crystal. The continuous variation of the splitting-width through T, suggests a second-order nature of this phase transition. The NQR frequency is consistent with the crystal structure in which the two acid hydrogen atoms of H2ca remain as attached to the quinone molecules. The spin-lattice relaxation time T, showed a decrease with decreasing temperature in the ferroelectric phase. This suggests the existence of a fast motion of nearby atomic group, which is a cause of electric field gradient fluctuation. (c) 2006 Elsevier B.V. All rights reserved.

    DOI: 10.1016/j.molstruc.2006.01.006

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  • ・2-Carboxypyridinium hydrogen chloranilate

    Youhei Tabuchi, Akiko Takahashi, Kazuma Gotoh, Haruo Akashi, Hiroyuki Ishida

    Acta. Cryst.,   61   O4215 - O4217   2005年12月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    The title compound, C6H6NO2 +·C6HCl2O4 -, is the salt of chloranilic acid with nicotinic acid (2-carboxypiridine), where an acid-base interaction involving a proton transfer is observed from the chloranilic acid to the pyridine group of nicotinic acid. In the crystal structure, the hydrogen chloranilate anion and the 2-carboxypridinium cation are linked by N-H⋯O and O-H⋯O hydrogen bonds to form a zigzag chain. The chains are further linked by O-H⋯O hydrogen bonds to form a three-dimensional hydrogen-bond network. © 2005 International Union of Crystallography Printed in Great Britain - all rights reserved.

    DOI: 10.1107/S1600536805037591

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  • Trimethylammonium tetrafluoroborate at 100 K

    K Gotoh, R Ishikawa, H Ishida

    ACTA CRYSTALLOGRAPHICA SECTION E-STRUCTURE REPORTS ONLINE   61   O4016 - O4017   2005年12月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:BLACKWELL PUBLISHING  

    The crystal structure of the title compound, C(3)H(10)N(+)center dot BF4-, has been redetermined at 100 K and shows the BF4- anion to be ordered at this temperature. Both the anion and the cation lie on a mirror plane and they are connected by N-H center dot center dot center dot F and C-H center dot center dot center dot F hydrogen bonds.

    DOI: 10.1107/S1600536805035592

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  • An NMR study on the dynamic behavior of triethylamine included in AFI crystals - Influence of acid sites on the motional state of triethylamine molecules -

    K Gotoh, S Ishimaru, R Ikeda

    BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN   76 ( 9 )   1723 - 1727   2003年9月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:CHEMICAL SOC JAPAN  

    The H-1 NMR spin-lattice relaxation times (T-1) of triethylamine (TEA) molecules included in five kinds of AFI crystals with different concentrations of Si atoms in the wall were measured. The temperature and Larmor frequency dependences of T-1 were well explained by introducing a distributed motional correlation time (tau) for the pseudo-C-3 TEA reorientation. An obtained linear decrease in the tau distribution width with an increase of the Si concentration, i.e., the number of Bronsted acid sites, was shown to be related to the orientations of TEA molecules in channels.

    DOI: 10.1246/bcsj.76.1723

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  • Dynamic behavior of acetonitrile molecules adsorbed in AlPO4-5 and SAPO-5 studied by H-1 and H-2 NMR

    S Ishimaru, K Gotoh, M Ichikawa, R Ikeda

    MICROPOROUS AND MESOPOROUS MATERIALS   51 ( 1 )   17 - 22   2002年1月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:ELSEVIER SCIENCE BV  

    We studied dynamic behavior of acetonitrile molecules adsorbed in molecular sieves AlPO4-5 and SAPO-5 by H-1 and H-2 solid state NMR methods and compared the result with that in bulk acetonitrile. The isotropic rotation of molecules is observed in AlPO4-5 above 200 K but they are bound to Bronsted acid sites on the wall in SAPO-5 even at room temperature. An anomalous frequency dependency of H-1 NMR T-1 observed in acetonitrile in SAPO-5 implies a large distribution of the environment around the molecules. This distribution of environment is attributable to the random arrangement in positions of acid sites and acetonitrile molecules, It was shown that molecules in AlPO4-5 are movable compared with those in bulk although the interaction with the pore wall seems to hinder motions. (C) 2002 Elsevier Science B.V. All rights reserved.

    DOI: 10.1016/S1387-1811(01)00463-2

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  • Dynamics of water molecules in micropores of AIPO(4)-5 and SAPO-5 studied by H-1 NMR

    K Gotoh, S Ishimaru, R Ikeda

    CHEMISTRY LETTERS   ( 12 )   1250 - 1251   2001年12月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:CHEMICAL SOC JAPAN  

    Dynamics of water molecules in one-dimensional micropores AlPO4-5 and SAPO-5 frameworks was studied by measuring H-1 NMR spectra, second moment M-2 of line-width and spin-lattice relaxation time T-1. Although the presence of two kinds of water molecules free and bound on the capillary wall were reported in AlPO4-5, our NMR T-1 results imply the absence of two kinds of H2O motions, but the motional rate distributes from slow to fast jumps in both AlPO4-5 and SAPO-5.

    DOI: 10.1246/cl.2001.1250

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  • Dynamic behaviour of triethylamine molecules adsorbed in aluminophosphate (AlPO4-5) and silicoaluminophosphate (SAPO-5) molecular sieves

    K Gotoh, S Ishimaru, R Ikeda

    PHYSICAL CHEMISTRY CHEMICAL PHYSICS   2 ( 8 )   1865 - 1869   2000年

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:ROYAL SOC CHEMISTRY  

    H-1 NMR spectra, second moments of line and spin-lattice relaxation times were measured for triethylamine (TEA) adsorbed in aluminophosphate (AlPO4-5) and silicoaluminophosphate (SAPO-5) molecular sieves in the temperature range 90 K to room temperature. Two modes of motions, molecular reorientations about the pseudo-C-3 axis and the isotropic rotation were observed in both systems. The fact that the former motion in SAPO-5 is hindered more than in AlPO4-5 was attributed to the hydrogen-bond formation between Bronsted acid sites and lone-pair electrons in TEA. This difference in interaction was shown to be the origin of the distribution of the motional correlation time (tau) in SAPO-5 less than in AlPO4-5 in which the presence of molecular C-3 axes in micropores oriented more randomly than in SAPO-5 result in a marked tau distribution.

    DOI: 10.1039/a908962d

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MISC

受賞

  • 研究奨励賞

    2013年12月   炭素材料学会  

    後藤 和馬

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共同研究・競争的資金等の研究

  • NMR study of carbon materials

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  • Dynamic Behavior of Molecules Adsorbed in Microporous Materials

    Funded Research 

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