2,6-Diamino­pyridinium dihydrogen phosphate

In the crystal structure of the title compound, C(5)H(8)N(3) (+)·H(2)PO(4) (−), N—H⋯O hydrogen bonds, involving the unprotonated amino-group and the NH(+) group in the pyridinium ring and dihydrogenphosphate O atoms, link the cations and anions. A long chain-like stacking of dihydrogenphosphate anions along the c-axis direction is constructed by O—H⋯O hydrogen bonds. Also along the c-axis direction, π–π stacking between inversion-related pyridinium rings [centroid–centroid distance = 3.8051 (10) Å] forms columnar stacks of cations.