Halogen bonding versus hydrogen bonding: what does the Cambridge Database reveal?

Abstract

A novel procedure for the thorough analysis of intermolecular interactions from structural data found in the Cambridge Structural Database has been developed, which takes into account the amount of space occupied by the interacting partners. Hence, volume-corrected probability distribution plots and relative abundance plots have been generated for molecule⋯ElR pairs (where molecule is a p-X-phenyl group with X = CH₃, F, Cl, Br, I or dichloromethane, and ElR stands for electron-rich atom, i.e. halogen, N, O, P, S, As, Se or Te), which clearly show the highly directional nature of halogen bonding and its potential competitiveness with hydrogen bonding.