Database research in crystal engineering

The Cambridge Structural Database is a storehouse of over 250 000 small-molecule organic and organometallic crystal structures. Statistical analysis of structural data provides a better understanding of the nature of hydrogen bonds and intermolecular interactions and facilitates in the identification of frequently occurring interaction patterns and supramolecular synthons. With an enhanced knowledge of hydrogen bond synthons in crystals, novel strategies may be designed for the self-assembly of supramolecular architectures from multi-functional molecules. The twin phenomena of polymorphism and pseudopolymorphism have been studied by extracting information on molecular conformations and solvent inclusion from the database. The approach geometry of hydrogen bond donors to various functional groups derived from small-molecule crystal structures is used as a model in structure-based drug design and pharmacophore mapping. Thus, the implications of crystal engineering today go far beyond organic and metal–organic crystal design into supramolecular materials, nanotechnology, ligand–protein binding and crystal structure prediction. This Highlight surveys the importance of database research in some of these areas.