Harris Kenneth D M, Cheung Eugene Y
School of Chemistry, Cardiff University, P.O. Box 912, Cardiff, Wales, UK.
Chem Soc Rev. 2004 Oct 20;33(8):526-38. doi: 10.1039/b409059b. Epub 2004 Sep 22.
Many crystalline solids cannot be prepared as single crystals of sufficient size and/or quality for structure determination to be carried out using single crystal X-ray diffraction techniques. In such cases, when only polycrystalline powders of a material are available, it is necessary instead to tackle structure determination using powder X-ray diffraction. This article highlights recent developments in the opportunities for determining crystal structures directly from powder diffraction data, focusing on the case of molecular solids and giving particular attention to the most challenging stage of the structure determination process, namely the structure solution stage. In particular, the direct-space strategy for structure solution is highlighted, as this approach has opened up new opportunities for the structure determination of molecular solids. The article gives an overview of the current state-of-the-art in structure determination of molecular solids from powder diffraction data. Relevant fundamental aspects of the techniques in this field are described, and examples are given to highlight the application of these techniques to determine crystal structures of molecular materials.
许多晶体固体无法制备出尺寸足够大且/或质量足够好的单晶，以便使用单晶X射线衍射技术进行结构测定。在这种情况下，当只有该材料的多晶粉末可用时，就需要转而使用粉末X射线衍射来解决结构测定问题。本文重点介绍了直接从粉末衍射数据确定晶体结构的最新进展，聚焦于分子固体的情况，并特别关注结构测定过程中最具挑战性的阶段，即结构解析阶段。特别强调了结构解析的直接空间策略，因为这种方法为分子固体的结构测定开辟了新的机会。本文概述了从粉末衍射数据测定分子固体结构的当前技术水平。描述了该领域技术的相关基本方面，并给出实例以突出这些技术在确定分子材料晶体结构中的应用。
