Survey and analysis of crystal polymorphism in organic structures

IUCrJ

Kersten, K.¹  Kaur, R.¹  Matzger, A.¹ 

[1]Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, MI 48109, USA

关键词: PHASE TRANSITIONS;    POLYMORPHS;    HYDRATES;    COCRYSTALS;    CAMBRIDGE STRUCTURAL DATABASE;   

DOI  :  10.1107/S2052252518000660

学科分类：数学（综合）

来源: International Union of Crystallography

【 摘 要 】

With the intention of producing the most comprehensive treatment of the prevalence of crystal polymorphism among structurally characterized materials, all polymorphic compounds flagged as such within the Cambridge Structural Database (CSD) are analysed and a list of crystallographically characterized organic polymorphic compounds is assembled. Classifying these structures into subclasses of anhydrates, salts, hydrates, non-hydrated solvates and cocrystals reveals that there are significant variations in polymorphism prevalence as a function of crystal type, a fact which has not previously been recognized in the literature. It is also shown that, as a percentage, polymorphic entries are decreasing temporally within the CSD, with the notable exception of cocrystals, which continue to rise at a rate that is a constant fraction of the overall entries. Some phenomena identified that require additional scrutiny include the relative prevalence of temperature-induced phase transitions among organic salts and the paucity of polymorphism in crystals with three or more chemical components.

【 授权许可】

CC BY