Bis[1-(2,3-di-methyl-phen-yl)piperazine-1,4-diium] bis-(oxonium) cyclo-hexa-phosphate dihydrate

In the title compound, 2C12H20N2 (2+)·2H3O(+)·P6O18 (6-)·2H2O, a protonated water mol-ecule bridges the centrosymmetrical anionic P6O18 ring via O-H⋯O hydrogen bonds. The centrosymmetric hydrogen-bonded rings formed by four oxonium cations and four phosphate anions can be described by an R 4 (8)(36) graph-set motif. The ring motifs are connected by hydrogen bonds into inorganic layers perpendicular to [100]. The 1-(2,3-di-methyl-phen-yl)piperazine-1,4-diium cations are located between the layers, compensating their negative charge and establishing N-H⋯O hydrogen bonds with the O atoms of the anionic framework.