有机分子晶体中的结构无序与构象差异

Structural Disorder and Conformation Difference in the Organic Molecular Crystals

目的 探讨晶态下分子中部分原子的无序现象，以期揭示自然界中有机分子存在构象差异的多构象性质。方法 应用单晶Ｘ射线衍射分析方法对４ 个天然有机化合物样品进行三维结构测定。结果 对晶态下分子的无序性质分析表明，部分原子的无序将造成分子间构象差异，形成晶态下的多构象，进而导致晶胞内分子排列对称性的降低。结论 有机分子晶体中由于分子局部无序或构象差异，造成在晶胞的一个不对称单位中可以存在双分子、三分子或多分子现象。

Objective Investigating multiple configuration nature of natural organic molecules through study on atom disorder in crystal state molecules. Methods Three dimensional determination for four natural organic compound samples by using single crystal X ray diffraction. Results Through disorder analysis on molecules in crystal state, we have found that the disorder of some atoms may cause conformation difference for molecules, bring about multiple conformation in crystal state hence reducing the symmetry of molecules in crystal cells. Conclusions There can be two or three molecules, even two different compounds in an asymmetrical unit of structure cell because of partial disorder or configuration difference in organic molecule crystals.