The reaction of propane-1,2-diamine (pn) and pyridine-2,6- dicarboxylic acid (pydcH2) in a 1:2 molar ratio in aqueous solution resulted in the formation of the title compound, C3H12N2 2+2C7H4NO42H2O or (pnH2)(pydcH)22H2O. The structure contains two monoanionic deprotonated forms of pyridine-2,6-dicarboxylic acid molecules (pydcH), a diprotonated propane-1,2-diamine (pnH2)2+, and two water molecules. A significant – stacking interaction is observed between the pyridyl rings of the (pydcH) fragments, with a face-to-face distance of 3.6194 (9) A ° . In the crystal structure, a wide range of non-covalent interactions consisting of ion pairing, hydrogen bonding [of the types of O—H O, N— H O, N—H N and C—H O, with D A distances in the range 2.454 (2)–3.222 (2)A° ] and – stacking interactions [centroid–centroid distance = 3.6194 (9) A ° ] connect the components into a supramolecular structure.
