著者

田村 類 高橋 弘樹 生塩 孝則

出版者

公益社団法人 日本化学会

雑誌

日本化学会誌 (ISSN:03694577)

巻号頁・発行日

vol.2001, no.2, pp.71-82, 2001 (Released:2004-02-20)

参考文献数

31

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有機ラセミ結晶の新しい自然光学分割現象を見いだし,これを優先富化現象と命名した.ラセミ結晶が優先富化現象を示すための必要条件を明らかにし,その機構を解明することを目的として,優先富化現象を示す化合物の誘導体や類縁体を合成し,これらの化合物の分子 · 結晶構造と優先富化現象の相関関係,これらのラセミ結晶の形態(ラセミ化合物,ラセミ混合物,ラセミ混晶の別)について系統的な研究を行った.その結果,X線結晶構造解析と融点相図の作成により,優先富化現象を示す化合物のラセミ結晶の形態は,きわめて秩序の高いラセミ化合物型の鏡像体間の混晶,あるいは中程度の秩序を持つ鏡像体間の混晶であることが判明した.一方,優先富化現象を示さない化合物のラセミ結晶の形態は,きわめて秩序の低い鏡像体間の混晶であることが示された.また,溶液中での鏡像体の会合構造を保持したまま結晶化したと考えられる結晶構造を得ることができたので,この構造を基にして,優先富化現象と密接に関連する結晶多形転移の機構を提唱する.

著者

田村 類 高橋 弘樹 生塩 孝則

出版者

The Society of Synthetic Organic Chemistry, Japan

雑誌

有機合成化学協会誌 (ISSN:00379980)

巻号頁・発行日

vol.56, no.1, pp.22-33, 1998-01-01 (Released:2009-11-16)

参考文献数

16

被引用文献数

1 3

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We have discovered the first case of accomplishment of an enantiomeric resolution by simple recrystallization of a series of racemic compounds [(±) forms] composed of a regular packing of (+) and (-) molecules in a crystal, although in principle this sort of enantiomeric resolution has been considered to be infeasible for more than a century since the discovery of chiral crystals by Pasteur and preferential crystallization of conglomerates by Gernetz which are a mixture of homochiral (+) and (-) crystals. We have designated this new enantiomeric resolution phenomenon as “Preferential Enrichment”. Here we report a distinct evidence that polymorphism between a racemic compound and a mixed crystal (solid solution), which consists of alternating alignment of the two homochiral dimers in a crystal, is responsible for the “Preferential Enrichment”, and we propose a mechanism of the phenomenon of the reversal of chirality in the deposited crystals, that is the essence of the “Preferential Enrichment”, on the basis of the polymorphic transformation during crystallization.

著者

津江 広人 堀口 雅弘 田村 類 藤井 孝太郎 植草 秀裕

出版者

The Society of Synthetic Organic Chemistry, Japan

雑誌

有機合成化学協会誌 (ISSN:00379980)

巻号頁・発行日

vol.65, no.12, pp.1203-1212, 2007-12-01 (Released:2010-10-20)

参考文献数

88

被引用文献数

35 52

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A single crystal X-ray diffraction method is the most powerful technique for the crystal structure determination of both organic and inorganic compounds. However, a number of organic compounds crystallize in a form of polycrystalline powder rather than a single crystal of suitable size and quality for X-ray crystallographic analysis. Recent remarkable developments of both software and hardware have turned X-ray powder diffraction method into another significant technique for solving crystal structure. In fact, not a few crystal structures solved from the powder diffraction data of organic compounds have been published in scientific papers. At the same time, however, it is also true that crystal structure solution from powder data is still a challenging subject; indeed, the structure solution cannot be executed in such an automatic manner as established in the single crystal method. In this article, we describe the details of the structure solution processes from X-ray powder diffraction data, together with the experimental know-how gained from our experiences.