Development of new nano-electron diffraction method for identification of crystal chirality and polarity

开发新的纳米电子衍射方法来鉴定晶体手性和极性

• 批准号: 16360346
• 负责人: INUI Haruyuki
• 金额: $ 9.73万
• 依托单位: Kyoto University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2004
• 资助国家: 日本
• 起止时间: 2004 至 2005
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-16360346/
• 关键词: chirality; polarity; convergent-beam election diffraction; crystal structure factor; multiple scattering; Friedel's law; Bijvoet pair; organic crystal; 収束電子回析

Enantiomorphism is usually referred to and used to describe objects that are lacking of improper rotation(rotoinversion and rotoreflections). Because of the absence of a center of symmetry (1^^-), a mirror plane (m=2^^-) and a 4^^-axis, such enantiomorphic (chiral) crystals or molecules can occur in two different forms that are related as a right hand and a left hand and these enantiomorphically-related crystals belong to either of the 11 crystal classes (point groups). These crystals are mirror related and are not superimposable with each other and one of the two enantiomorphic crystals exhibit optical bioactivities different from the other in most cases Therefore, distinction of chirality of enantiomorphic crystals is sometimes very important, as the well-known example of Thalidmide accident, which occurred as a tragedy due to the harmful side effect of one of the two members of the enantiomorphic crystals, has indicated. We have developed a new CBED method for identification of chirality and polarity of enantiomorphic crystals, in which asymmetry in the intensity of reflections of Bijvoet pairs in an experimental symmetrical zone-axis CBED pattern is compared with that of an computer simulated CBED pattern. The intensity difference for reflections of these Bijvoet pairs results from multiple scattering (dynamical nature of electron diffraction) among relevant Bijvoet pairs of reflections, each pair of which have identical amplitude and different phase angles. Therefore, the crystal thickness where chiral identification is made with the present method is limited by the extinction distance of Bijvoet pairs of reflections relevant to multiple scattering to produce the intensity asymmetry, which is usually of the order of a few tens nm. With the present method, only a single CBED pattern is sufficient and chiral identification can be made for all possible enantiomorphic crystals that are allowed to exist in crystallography.

对映同构通常被用来描述没有不适当旋转的物体（旋转反转和旋转反射）。由于不存在对称中心（1^^-）、镜面（m=2^^-）和4^^-轴，这样的对映体（手性）晶体或分子可以以两种不同的形式存在，其相关为右手和左手，并且这些对映体相关的晶体属于11种晶体类（点群）中的任一种。这些晶体是镜像相关的，并且彼此不能重叠，并且两个对映体晶体中的一个在大多数情况下表现出与另一个不同的光学生物活性。因此，对映体晶体的手性的区分有时是非常重要的，如众所周知的Thalidmide事故的例子，其由于对映体晶体的两个成员之一的有害副作用而发生悲剧，表示。我们发展了一种新的CBED方法来鉴定对映体晶体的手性和极性，其中在实验对称带轴CBED图案中的Bijvoet对的反射强度的不对称性与计算机模拟CBED图案的不对称性进行了比较。这些Bijvoet对的反射的强度差是由相关的Bijvoet对的反射之间的多次散射（电子衍射的动力学性质）引起的，每对反射具有相同的振幅和不同的相位角。因此，用本方法进行手性鉴定的晶体厚度受到与多重散射相关的反射的Bijvoet对的消光距离的限制，以产生强度不对称性，其通常为几十nm的量级。使用本方法，仅单个CBED图案就足够了，并且可以对晶体学中允许存在的所有可能的对映体晶体进行手性鉴定。

项目成果

Identification of Crystal Chirality by CBED Method (in Japanese)

CBED法鉴定晶体手性（日文）

• 发表时间: 2004
• 期刊: Materia 43
• 作者: E.Terada;M-W.Oh;D.M.Wee;H.Inui;H.Inui;H.Inui;H.Inui;H.Inui;H.Inui;乾 晴行;H.Inui;H.Inui et al.;H.Inui et al.;H.Inui et al.;H.Inui et al.
• 通讯作者: H.Inui et al.

新たな研究展望-金属間化合物研究から生命・医療科学への展開

研究新前景——从金属间化合物研究向生命医学科学发展

• 发表时间: 2006
• 期刊: 金属 76・7(In press)
• 作者: Makoto Ohtsuka;et al.;大沼 繁弘(複数共著);大沼 繁弘(複数共著);Makoto Ohtsuka et al.;K.Ueda;平 雅之;K.Ueda;M.Taira;平 雅之;K.Ueda;平 雅之;M.Taira;H.Inui;H.Inui;H.Inui;乾 晴行
• 通讯作者: 乾 晴行

Enantiomorph Identification of Crystals Belonging to the Point Groups of 622 and 6 by New Convergent-Beam Electron Diffraction Method

新会聚束电子衍射法鉴定622和6点群晶体的对映体

• 发表时间: 2005
• 期刊: Acta Materialia 53(In press)
• 作者: E.Terada;M-W.Oh;D.M.Wee;H.Inui;H.Inui;H.Inui;H.Inui
• 通讯作者: H.Inui

Enantiomorph Identification of Crystals Belonging to the Point Groups of 622 and 6 by Convergent-Beam Electron Diffraction Method

会聚束电子衍射法鉴定622和6点群晶体的对映体

• 发表时间: 2006
• 期刊: Intermetallics (In press)
• 作者: Makoto Ohtsuka;et al.;大沼 繁弘(複数共著);大沼 繁弘(複数共著);Makoto Ohtsuka et al.;K.Ueda;平 雅之;K.Ueda;M.Taira;平 雅之;K.Ueda;平 雅之;M.Taira;H.Inui
• 通讯作者: H.Inui

Enantiomorph Identification of Transition-Metal Disilicides with the C40 Structure (the Space Group of P6_222 and P6_422) by New Convergent-Beam Electron Diffraction

新型会聚束电子衍射对C40结构（P6_222和P6_422空间群）过渡金属二硅化物的对映体识别

• 发表时间: 2005
• 期刊: Acta Materialia 53・1
• 作者: H.Sakamoto;A.Fujii;K.Tanaka;H.Inui
• 通讯作者: H.Inui