2,6-Diaminopyridinium dihydrogen phosphate

In the crystal structure of the title compound, C5H8N3+center dot H2PO4 (-), N-H center dot center dot center dot 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 center dot center dot center dot O hydrogen bonds. Also along the c-axis direction, pi-pi stacking between inversion-related pyridinium rings [centroidcentroid distance = 3.8051 (10) angstrom] forms columnar stacks of cations.