Bis(4-aminopyridinium) μ6-oxido-dodeca-μ2-oxido-hexaoxido[rhenium(VII)tetratungsten(VI)vanadium(V)]ate heptahydrate

In the title organic–inorganic hybrid compound, (C5H7N2)2[ReVW4O19]·7H2O, the Lindqvist-type polyoxido anion has crystallographically imposed mm2 symmetry and is built up by six MO6 (M = W, V, Re) edge-sharing distorted octahedra. The Re and V atoms share the same crystallographic site in a 0.5:0.5 ratio. The 4-aminopyridinium cations lie on a mirror plane. Three of the four independent water O atoms in the asymmetric unit are located on a mirror plane whereas the remaining O atom has mm2 site symmetry. In the crystal, the cations, anions and water molecules are linked into a three-dimensional network through O—H...O and N—H...O hydrogen-bonding interactions