Molecular Shape as a Design Criterion

Abstract

Many applications of crystalline materials depend not just on the underlying molecular structures, but equally on the alignment of molecules in the crystals. An understanding of molecular arrangements is critical to the design of materials with specific bulk properties. Crystal structure reports have traditionally contained little significant discussion (frequently no mention at all) of molecular arrangements in the crystal, presumably because the motivation for many studies was the elucidation of some molecular feature. The Cambridge Structural Database [1] makes available crystal data for many thousands of organic and organometallic crystal structures, together with continually evolving retrieval and analysis software. The commitment at the Data Centre to the development of increasingly powerful software for 3-dimensional search, analysis, and display is changing the landscape of the study of crystal packing. This superb set of tools facilitates many important and innovative programs of study that are slowly but surely increasing our understanding of molecular solid state structure. This systematic study is, in turn, fueling significant progress in crystal engineering, one of the major themes of this School. Useful reviews in this area include those by Desiraju [2] and by Braga and Grepioni [3] (both of these surveying a broad range of intermolecular interactions) and those by Aakeroy [4, 5] and Zaworotko [6] (focusing more specifically on the exploitation of hydrogen-bonding as a design tool).