Amino­[(1H-benzimidazol-2-yl)amino]­methaniminium 4-methyl­benzene­sulfonate

The asymmetric unit of the title salt, C₈H₁₀N₅⁺·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...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...O and C—H...O hydrogen bonds, forming a three-dimensional supra­molecular framework. Two strong π–π stacking inter­actions [centroid–centroid distances = 3.4112 (14) and 3.4104 (14) Å] also occur between the centroids of the imidazole rings of like cations.