Direct observation of crystalline-state reactions by single crystal neutron diffraction analyses

Ohara, Takashi; Hosoya, Takaaki; Ohashi, Yuji*

Nihon Kessho Gakkai-Shi, 50(1), p.98 - 102, 2008/02

https://doi.org/10.5940/jcrsj.50.98

The exchange of some hydrogen atoms with the other hydrogen atoms in the crystalline-state reactions, in which the reaction proceeds with retention of the single crystal form, can be directory observed by single crystal neutron diffraction technique if only the transferred hydrogen atoms were replaced with deuterium atoms before the photoirradiation. The method was successfully applied in the photoisomerization of three kinds of cobalt complex crystals and the mechanism in each reaction has been made clear.

Neutron diffraction analysis of deuterium transfer in chiral -thiolactam formation in the crystalline state

Hosoya, Takaaki*; Uekusa, Hidehiro*; Ohashi, Yuji*; Ohara, Takashi; Tanaka, Ichiro*; Niimura, Nobuo*

Acta Crystallographica Section B; Structural Science, Crystal Engineering and Materials (Internet), 62(1), p.153 - 160, 2006/02

https://doi.org/10.1107/S0108768105038656

Since N,N-dibenzyl-1-cyclohexenecarbothioamide is photoisomerized to the optically active -thiolactam with the retention of the single-crystal form, the mechanism of chirality induction was identified by X-ray crystal structure analyses during the process of the reaction. In order to clarify the mechanism of hydrogen transfer in the reaction, the H atomsof the benzyl groups were replaced with deuterium atoms. The crystal structure after photoisomerization was analyzed by neutron diffraction. One of four deuterium atoms of the two benzyl groups is transferred to the C atom of the cyclohexene ring. The absolute configuration of the -CHD- group(chiral methylene) in the photoproduct r-thiolactam revealed that the deuterium atom occupies the equatorial position. This suggests that the deuterium atom is not transferred from the benzyl group of a neighbouring molecule, but from one of the benzyl groups within the molecule.

Evidence for a narrow = +1 Baryon resonance in photoproduction from the neutron

Nakano, Takashi*; Ahn, D. S.*; Ahn, J. K.*; Akimune, Hidetoshi*; Asano, Yoshihiro; Chang, W. C.*; Date, S.*; Ejiri, Hiroyasu*; Fujimura, Hisako*; Fujiwara, Mamoru; et al.

Physical Review Letters, 91(1), p.012002_1 - 012002_4, 2003/07

https://doi.org/10.1103/PhysRevLett.91.012002

no abstracts in English

Study on the development of geological environmental model

Tsujimoto, Keiichi*; Shinohara, Yoshinori*; Saito, Shigeyuki*; Ueta, Shinzo*; *; *; *

JNC TJ8400 2002-019, 480 Pages, 2002/03

JNC-TJ8400-2002-019.pdf:7.86MB

The safety performance assessment was carried out in potential geological environment in the conventional research and development of geological disposal, but the importance of safety assessment based on the repository design and scenario considering the concrete geological environment will increase in the future. The research considering the link of the major three fields of geological disposal, investigation of geological environment, repository design, and safety performance assessment, is the contemporary worldwide research theme. Hence it is important to organize information flow that contains the series of information process form the data production to analysis in the three fields, and to systemize the knowledge base that unifies the information flow hierarchically. The purpose of the research is to support the development of the unified analysis system for geological disposal. The development technology for geological environmental model studied for the second progress report by JNC are organized and examined for the purpose of developing database system with considering the suitability for the deep underground research facility. The geological environmental investigation technology and building methodology for geological structure and hydro geological structure models are organized and systemized. Furthermore, the quality assurance methods in building geological environment models are examined. Information which is used and stored in the unified analysis system are examined to design database structure of the system based on the organized methodlogy for building geological environmental model. The graphic processing function for data stored in the unified database are examined. Furthermore, future research subjects for the development of detail models for geological disposal are surveyed to organize safety performance system.

High power test of RF cavity for SPring-8 booster synchrotron

Suzuki, Hiromitsu; *; Yonehara, Hiroto; Harami, Taikan; ; Kawashima, Yoshitaka*; *; Inoue, K.*; Hara, Masahiro*; *

Proc. of the 8th Symp. on Accelerator Science and Technology, p.113 - 115, 1991/00

no abstracts in English