The title compound, C3H12N2 2+C7H3NO4 2H2O, contains one dicationic fragment, one dianionic fragment and one water molecule. The two carboxylate groups of the pyridine- 2,3-dicarboxylate (pydc2) fragment are almost perpendicular to each other [dihedral angle 83.10 (8)]. In the crystal structure, intermolecular N—H O, N—H N, O—H O and C—H O hydrogen bonds and edge-to-face – stacking, together with ion pairing, are responsible for extending the structure in three dimensions, resulting in a supramolecular network.
