ACTA CRYSTALLOGRAPHICA SECTION E-CRYSTALLOGRAPHIC COMMUNICATIONS, vol.69, 2013 (ESCI)
The asymmetric unit of the title salt, C8H10N5+center dot C7H7O3S-, consists of two amino[(1H-benzimidazol-2-yl)amino]methaniminium cations and two 4-methylbenzenesulfonate anions. The cations are each stabilized by intramolecular N-H center dot center dot center dot N hydrogen bonds between the free amino groups and the imine N atoms of the benzimidazole units, forming S(6) ring motifs. In the crystal, cations and anions are linked by N-H center dot center dot center dot O and C-H center dot center dot center dot O hydrogen bonds, forming a three-dimensional supramolecular framework. Two strong pi-pi stacking interactions [centroid-centroid distances = 3.4112 (14) and 3.4104 (14) angstrom] also occur between the centroids of the imidazole rings of like cations.