Solid state hydrogen bonding in imidazole derivatives: A persistent tape motif

The Cambridge Structural Database was mined for non N-substituted, neutral imidazole derivatives. Solid states with metal centres bound to the imidazole nitrogen atoms and ionic species were not included. The N-N, hydrogen-bound, tape motif was found to be a structural trend in the solid-state of neutral imidazole derivatives in the presence of possible competing hydrogen bonds and in highly steric environments. A chemically intuitive set of parameters was chosen to characterize the relationships between imidazole rings in the solid states. The choice of structural parameters and the values these parameters take as a function of substitution patterns of imidazole derivatives was discussed. The complexities that can arise in the crude extraction of hydrogen bond strength from solid state data was discussed.