Bis{tris­[3-(2-pyrid­yl)-1H-pyrazole]nickel(II)} dodeca­molybdo(V,VI)phosphate hexa­hydrate

The hydro­thermally prepared title compound, [Ni(C(8)H(7)N(3))(3)](2)[PMo(12)O(40)]·6H(2)O, is a member of the isotypic series [(M(C(8)H(7)N(3))(3)](2)[PMo(12)O(40)]·6H(2)O where M is Mn, Cd, and Fe. The Ni(2+) cation is in a distorted octa­hedral environment, coordinated by six N atoms from three chelating 3-(2-pyrid­yl)-1H-pyrazole ligands. In the one-electron reduced heteropolyanion, two O atoms of the central PO(4) group ([Image: see text] symmetry) are equally disordered about an inversion centre. N—H⋯O and O—H⋯O hydrogen bonds contribute to the crystal packing. Compared with the isotypic structures, the main difference is related with the M—N bond lengths, whereas all other bond lengths, angles and the hydrogen-bonding motifs are very similar.