2-Amino-5-methyl-pyridinium 3-carb-oxy-4-hy-droxy-benzene-sulfonate

The asymmetric unit of the title salt, C(6)H(9)N(2) (+)·C(7)H(5)O(6)S(-), contains two crystallographically independent 2-amino-5-methylpyridinium cations and two sulfosalicylate anions. In the crystal structure, the sulfonate group of each 3-carb-oxy-4-hy-droxy-benzene-sulfonate anion inter-acts with the corresponding 2-amino-5-methyl-pyridinium cation via a pair of N-H⋯O hydrogen bonds, forming an R(2) (2)(8) ring motif. The ionic units are linked by N-H⋯O, O-H⋯O and C-H⋯O hydrogen bonds. Furthermore, the crystal structure is stabilized by π-π inter-actions between the benzene and pyridine rings [centroid-centroid distances = 3.5579 (8) and 3.8309 (8) Å]. There are also intra-molecular O-H⋯O hydrogen bonds in the anions, which generate S(6) ring motifs.