研究领域

Chemical Crystallography/Organic Crystal Chemistry

From many recent studies, molecules in crystalline-state are understood to be able to "move and react" in rather unrestricted manner. Our major interests are to reveal such motion and change caused by light irradiation, temperature and relative humidity change based on X-ray crystal structure analysis. To examine very small crystals or crystalline-phase after reaction, the structure determination from powder diffraction data technique is specially employed. Other interests are in crystal engineering method to form functional inclusion crystals, very short lifetime intermediates (excited state spieces) observed in crystalline matrix, and photochromic and thermochromic mechanism in crystals. Research Topics： Analysis of crystalline-state reaction mechanism Excited-state and unstable intermediates structure analysis Structure determination from powder diffraction data Development of very rapid diffraction measurement equipment New functional organic inclusion crystal Message from the LaboratoryWe encourage students to present their results in an international and national meeting. In the process they develop the ability to summarize and to present the study. We usually present in IUCr, AsCA, ECM, and Pacifichem meetings, and local CSJ and CrSJ meetings.

近期论文

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Reversible Color Switching of an Organic Crystal Induced by Organic Solvent Vapors Kotaro Fujii, Aya Sakon, Akiko Sekine, Hidehiro Uekusa Crystal Growth & Design , 11 , (10), 4305-4308 (2011). 連載企画　有機粉末構造解析をはじめよう！ 「試料準備から測定まで」, 藤井 孝太郎、植草 秀裕, 日本結晶学会誌 , 53, (3), 170-177 (2011). 連載企画　有機粉末構造解析をはじめよう！ 「粉末未知結晶構造解析の紹介」, 植草 秀裕、藤井 孝太郎, 日本結晶学会誌 , 53, (3), 163-170 (2011). Direct observation of different reaction pathways by X-rays in the photoisomerization of cobaloxime complexes with diphenylboron bridging, Akira Hirano, Akiko Sekine, Hidehiro Uekusa, Yuji Ohashi, Bull. Chem. Soc. Jpn. , 84, (5), 496-504 (2011). Supramolecular Networks in Crystalline Inclusion Complexes Formed from a New Host: 2,2-Bis(4-hydroxy-3-phenylphenyl)-1H-indene-1,3(2H)-dione. Kenta Kasugai, Suzumi Hashimoto, Kazunori Imai, Aya Sakon, Kotaro Fujii, Hidehiro Uekusa, Naoto Hayashi, Keiji Kobayashi, Cryst. Growth & Des. , 11, (9), 4044-4052 (2011). Potential of synchrotron X-ray powder diffractometry for detection and quantification of small amounts of crystalline drug substances in pharmaceutical tablets, Hiroyuki Yamada, Katsuhiko Masuda, Takayuki Ishige, Kotaro Fujiic, Hidehiro Uekusa, Keiko Miura, Etsuo Yonemochi, Katsuhide Terada. Journal of Pharmaceutical and Biomedical Analysis , 56, (2), 448-453 (2011). Photorearrangements in spiro-conjoined cyclohexa-2,5-dien-1-one. Masaya Suzuki, Kazunori Imai, Hidetsugu Wakabayashi, Atsuko Arita, Kohei Johmoto, Hidehiro Uekusa, Keiji Kobayashi. Tetrahedron, 67, (30), 5500-5506 (2011). C-24 stereochemistry of marine sterols: (22E)-24-ethyl-24-methylcholesta-5,22-dien-3β-ol and 24-ethyl-24-methylcholest-5-en-3β-ol. Shizue Echigo, Leonardo Castellanos, Carmenza Duque, Hidehiro Uekusa, Noriyuki Hara and Yoshinori Fujimoto. J. Braz. Chem. Soc., 22, (5), 997-1004 (2011). Metastable polymorphic form of isopropylbenzophenone derivative directly obtained by the solid-state photoreaction investigated by ab initio powder X-ray diffraction analysis. Kotaro Fujii, Hidehiro Uekusa, Michitaro Fukano,Hideko Koshima. CrystEngComm, 13, (3), 3197-3201 (2011). 粉末結晶解析を用いた溶媒蒸気による多形転移現象の解析. 藤井孝太郎、植草　秀裕. 化学工業, 64, (4), 262-268 (2011). Crystal structure of 1,3,5-trimethylpyridinium iodide. Nabel H. Buttrus, Amer A. Taqa, Eman M. R. Rumadthan, Kohei Johmoto, Hidehiro Uekusa. X-Ray Structure Analysis Online , 27, (4), 19-20 (2011). In situ observation and mechanistic elucidation of metastable colored species in crystalline state photochromism of trans-biindenylidenedione. Kotaro Fujii, Kumiko Aruga, Akiko Sekine, Hidehiro Uekusa, Katsuya Sohno, Koichi Tanaka. CrystEngComm, 13, (3), 731-733 (2011). Study of the Pseudo-Crystalline Transformation from Form I to Form II of Thiamine Hydrochloride (Vitamin B1). Katsuhiko Masuda, Takayuki Ishige, Hiroyuki Yamada, Kotaro Fujii, Hidehiro Uekusa, Keiko Miura, Etsuo Yonemochi, Katsuhide Terada. Chem. Pharm. Bull., 59(1), 57-62 (2011). Cocrystalline phase transformation of binary mixture of trimethoprim and sulfamethoxazole by slurry technique. Erizal Zaini, Yeyet C. Sumirtapura, Sundani N. Soewandhi, Auzal Halim, Hidehiro Uekusa, Kotaro Fujii. Asian Journal of Pharmaceutical and Clinical Research, 3(4), 26-29 (2010). Direct observation of various reaction pathways of arylnitrenes in different crystal environments caused by acid-base complex formation. Takahiro Mitsumori, Akiko Sekine, Hidehiro Uekusa, Yuji Ohashi. Acta Cryst., B66(6), 647-661 (2010). Direct observation of arylnitrene formation in the photoreaction of arylazide crystals. Terufumi Takayama, Takahiro Mitsumori, Masaki Kawano, Akiko Sekine, Hidehiro Uekusa, Yuji Ohashi, Tadashi Sugawara. Acta Cryst., B66(6), 639-646 (2010). Strain-promoted double-click reaction for chemical modification of azido-biomolecules. Isao Kii, Akira Shiraishi, Toshiyuki Hiramatsu, Takeshi Matsushita, Hidehiro Uekusa, Suguru Yoshida, Makoto Yamamoto, Akira Kudo, Masatoshi Hagiwara,Takamitsu Hosoya. Org. Biomol. Chem., 8, 4051-4055 (2010). Potassium clavulanate. Kotaro Fujii, Kazuyuki Toyota, Akiko Sekine, Hidehiro Uekusa, Ilma Nugrahani, Sukmadjaja Asyarie, N. Sundani Soewandhi, Slamet Ibrahim. Acta Cryst., E66(8), m985-m986 (2010). Polymorphic Crystal Approach to Changing the Emission of [AuCl(PPh3)2], Analyzed by Direct Observation of the Photoexcited Structures by X-ray Photocrystallography. Manabu Hoshino, Hidehiro Uekusa, Satoshi Ishii, Takuhiro Otsuka, Youkoh Kaizu, Yoshiki Ozawa, Koshiro Toriumi. Inorg. Chem., 49(16), 7257-7265 (2010). Selective transformation pathways between crystalline forms of an organic material established from powder X-ray diffraction analysis. Kotaro Fujii, Yasunari Ashida, Hidehiro Uekusa, Fang Guo, Kenneth D. M. Harris. Chem. Commun., 46(24), 4264-4266 (2010).