Interactions of guanidinium with benzene-sulphonic, -phosphonic and -arsonic acids and several of their nitro-derivatives

Abstract

The supramolecular interactions of the planar guanidinium cation (C(NH2)3+) with benzenesulphonate (1), -phosphonate (2) and -arsonate (3) anions, and several of their 3- and 4-nitro-substituted derivatives is reported. In all cases well-defined crystalline materials, containing hydrogen-bonded networks with quasi-hexagonal sheet lattices were formed. However, the unsubstituted sulphonate (1) formed a 1:1 guanidinium:sulphonate bilayer structure, whilst the unsubstituted phosphonate (2) and arsonate (3) formed 2:1 guanidinium: phosphonate/arsonate single-layer structures with water occluded within the crystal voids. The additional H-bonding interactions resulting in distortion of the crystal..