Abstract
The title compound, C(10)H(15)N(2) (+)·H(2)PO(4) (-), is built up from 4-phenyl-piperazin-1-ium cations and dihydrogen phosphate anions. The inter-connection between two adjacent anions is assured by two strong O-H⋯O hydrogen bonds, which lead to the formation of infinite wave-like chains which spread along the a axis. The organic cations connect these chains via N-H⋯O hydrogen bonds. The crystal cohesion and stability are ensured by electrostatic and van der Waals inter-actions which, together with N-H⋯O and O-H⋯O hydrogen bonds, build up a two-dimensional network.