2-Amino-6-methyl­pyridinium 4-methyl­benzene­sulfonate

In the asymmetric unit of the title salt, C(6)H(9)N(2) (+)·C(7)H(7)O(3)S(−), there are two independent 2-amino-6-methyl­pyridinium cations and two independent 4-methyl­benzene­sulfonate anions. Both cations are protonated at their pyridine N atoms and their geometries reveal amine–imine tautomerism. In the 4-methyl­benzene­sulfonate anions, the carboxyl­ate groups are twisted out of the benzene ring planes by 88.4 (1) and 86.2 (2)°. In the crystal, the sulfonate O atoms of an anion inter­act with the protonated N atoms and the 2-amino groups of a cation via a pair of N—H⋯O hydrogen bonds, forming an R (2) (2)(8) ring motif. These motifs are connected via N—H⋯O hydrogen bonds, forming chains running along the a-axis direction. Within the chains there are weak C—H⋯O hydrogen bonds present. In addition, aromatic π–π stacking inter­actions [centroid–centroid distances = 3.771 (2), 3.599 (2), 3.599 (2) and 3.497 (2) Å] involving neighbouring chains are also observed.