The clash of the synthons: crystal structures of benzimidazole–alcohol–carboxylic acids

Abstract

The crystal structures of a series of compounds containing protonated benzimidazole functions are reported. Hydrogen bonds are always seen in the plane of the benzimidazole but, in opposition to our previous work, stacking interactions between the benzimidazole cations are not invariably observed. In zwitterionic benzimidazole carboxylic acid compounds, a gauche conformation is often adopted which allows a Coulombic attraction between carboxylate and benzimidazolonium functions.