4-Cyano­pyridinium dihydrogen phosphate–isonicotinonitrile–phospho­ric acid (1/1/1)

The asymmetric unit of the title compound, C(6)H(5)N(2) (+)·H(2)PO(4) (−)·C(6)H(4)N(2)·H(3)PO(4), contains one 4-cyano­pyridinium cation, one H(2)PO(4) (−) anion, one independent isonicotinonitrile mol­ecule and one independent H(3)PO(4) mol­ecule. The dihedral angle between the mean planes of the separate protonated and unprotonated pyridine rings is 9.93 (8)°. In the crystal, N—H⋯O and O—H⋯N hydrogen bonds and weak C—H⋯O and C—H⋯N inter­molecular inter­actions connect the organic mol­ecules into a two-dimensional network parallel to the ac plane. O—H⋯O hydrogen-bonding inter­actions involving the H(2)PO(4) (−) anions and H(3)PO(4) mol­ecules provide additional support from the inorganic groups Weak π–π stacking inter­actions between the pyridine rings of neighbouring organic mol­ecules [centroid–centroid distances = 3.711 (4) and 3.784 (2) Å] further link the layers into a three-dimensional network.