Molecular packings and specific-bonding patterns in sulfonamides

Abstract

A novel approach to topological analysis of molecular packings and intermolecular bonding patterns is described and tested on the crystal structures of 1463 sulfonamide derivatives taken from the Cambridge Structural Database, as well as three newly synthesized ones. We have revealed strong correlations between the local and overall topological motifs of hydrogen and halogen specific intermolecular bonds; as a rule, a particular local connection type of the molecules provides only one most preferred pattern of intermolecular bonds and vice versa. Molecular packings are found to be almost independent of the existence or absence of specific bonds and in more than 1/3 of cases they obey Kitaigorodskii's model of close packing. The peculiar shapes of the sulfonamide molecules in some cases give rise to a special ‘butterfly’ packing that is topologically less dense than close packings. The correlations found can be used to predict the main peculiarities of molecular crystals with a prospective expert system.