Dimethylammonium 5-carboxy-2-(1-oxo-1λ5-pyridin-2-yl)-1H-imidazole-4-carboxylate

In the title salt, C2H8N+·C10H6N3O5−, the imidazolecarboxylate anion is essentially planar [maximum deviation from the least-squares plane = 0.046 (5) Å], with a dihedral angle between the rings of 2.7 (2)°. This conformation is maintained by the presence of both intramolecular carboxy–carboxylate O—H...O and imidazole–oxide N—H...O hydrogen bonds. Iin the crystal, cation–carboxylate N—H...O and cation–imidazole N—H...N hydrogen bonds result in chains along the b axis.