Bis{tris-[3-(2-pyrid-yl)-1H-pyrazole]manganese(II)} dodeca-molybdo(V,VI)phosphate hexa-hydrate

Bis{tris-[3-(2-pyrid-yl)-1H-pyrazole]nickel(II)} dodeca-molybdo(V,VI)phosphate hexa-hydrate

The hydro­thermally prepared title compound, [Ni(C₈H₇N₃)₃]₂[PMo₁₂O₄₀]·6H₂O, is a member of the isotypic series [(M(C₈H₇N₃)₃]₂[PMo₁₂O₄₀]·6H₂O where M is Mn, Cd, and Fe. The Ni²⁺ 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 PO₄ group ( 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.

Bis{tris-[3-(2-pyrid-yl)-1H-pyrazole]iron(II)} dodeca-molybdo(V,VI)phosphate hexa-hydrate

Crystals of the title compound, [Fe(C₈H₇N₃)₃]₂[PMo₁₂O₄₀]·6H₂O, prepared under hydro­thermal conditions, are isotypic with the Mn²⁺ and Cd²⁺ analogues. The Fe²⁺ cation is in a distorted octa­hedral coordination by six N atoms from three chelating 3-(2-pyrid­yl)-1H-pyrazole ligands. The heteropoly­anion [PMo₁₂O₄₀]⁴⁻ is a one-electron reduced species in which two O atoms of the central PO₄ group ( symmetry) are equally disordered about an inversion centre. N—H⋯O and O—H⋯O hydrogen bonds make a contribution to the crystal packing. The Fe—N bond lengths [2.085 (19)—2.15 (2) Å] are somewhat shorter than the Mn—N and Cd—N bond lengths [2.224 (6)–2.283 (5) and 2.316 (7)–2.334 (6) Å, respectively]. All other bond lengths and angles and the hydrogen-bonding motifs are very similar in the isotypic structures.

Bis{tris-[3-(2-pyrid-yl)-1H-pyrazole]cadmium(II)} dodeca-molybdo(V,VI)phosphate hexa-hydrate

The hydro­thermally prepared title compound, [Cd(C₈H₇N₃)₃]₂[PMo₁₂O₄₀]·6H₂O, is isotypic with its Mn^II analogue [Hao et al. (2010 ▶). Acta Cryst. E66, m231–m232]. The Cd^II cation is in a distorted octa­hedral environment, coordinated by six N atoms from three chelating 3-(2-pyrid­yl)-1H-pyrazole ligands. In the reduced heteropolyanion, two O atoms of the central PO₄ group ( 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 Mn^II analogue, the Cd—N bond lengths are longer at 2.316 (7)–2.334 (6) Å, versus 2.224 (6)–2.283 (5) Å for Mn—N, whereas all other bond lengths and angles and the hydrogen-bonding motifs are very similar in the two structures.