2-Amino-5-methylpyridinium 2-carboxybenzoate

In the title salt, C6H9N2 +·C8H5O4 −, the hydrogen phthalate anion is essentially planar, with a maximum deviation of 0.011 (2) Å. In the crystal structure, the protonated N atom of the pyridine ring and the 2-amino group of the cation are hydrogen bonded to the carboxylate O atoms of the anion via a pair of N—H⋯O hydrogen bonds, forming an R 2 2(8) ring motif. In the hydrogen phthalate anion, there is a very strong, almost symmetric, intramolecular O—H⋯O hydrogen bond, generating an S(7) motif [O⋯O = 2.382 (3) Å]. Furthermore, these two molecular motif rings are connected by a bifurcated N—H⋯(O,O) hydrogen-bonded motif R 1 2(4), forming a supramolecular ribbon along the b axis. The crystal structure is further stabilized by π–π interactions between the cations and anions [centroid–centroid distance = 3.6999 (10) Å].