Concomitant and Conformational Polymorphism, Conformational Isomorphism, and Phase Relationships in 4-Cyanopyridine·4,4‘-biphenol Cocrystals

• DOI: 10.1021/cg0680024
• Publication Date: 2006-04-05T04:23:18Z
• Authors: Joanna A. Bis; Peddy Vishweshwar; Richard A. Middleton; Michael J. Zaworotko
• Keywords: Isomorphism (crystallography)

The 2:1 co-crystal of 4-cyanopyridine and 4,4'-biphenol exists in at least two polymorphic forms. Single-crystal X-ray crystallographic analysis forms I II revealed conformational differences the molecules, but O−H···N(pyridine) supramolecular heterosynthons sustain both forms, suggesting that interactions are favored over competing O−H···N(cyano) interactions. These polymorphs crystallize concomitantly, isomorphism is also observed this co-crystal. Experimental conditions induce transformations between form described. structural discussed broader context polymorphism.