Crystal structure of bis[4-(dimethylamino)pyridinium] aquabis(oxalato)oxidovanadate(IV) dihydrate

The title organic-inorganic hybrid salt, (C7H11N2)(2)[V(C2O4)(2)O(H2O)]center dot 2H(2)O, shows a distorted octahedral coordination environment for the vanadium(IV) atom in the anion (point group symmetry 2), with four O atoms from two symmetry-related chelating oxalate dianions and two O atoms in trans configuration from a coordinating water molecule and a terminal vanadyl O atom. In the crystal, (001) layers of cations and anions alternate along [001]. The anionic layers are built up by intermolecular O-H center dot center dot center dot O hydrogen bonds involving the coordinating and solvent water molecules. The cationic layers are linked to the anionic layers via N-H center dot center dot center dot O hydrogen bonds between the pyridinium group and the non-coordinating O atoms of the oxalate group. The 4-(dimethylamino) pyridinium cations are also engaged in pi-pi stacking with their antiparallel neighbours [centroid-to-centroid distance = 3.686 (2) angstrom]. Considering all supramolecular features, a three-dimensional network structure is accomplished.