Tetra­aqua­bis­­(pyridine-3-carbo­nitrile-κN1)nickel(II) benzene-1,4-di­carboxyl­ate tetra­hydrate

A nickel(II) terephthalate complex, viz. [Ni(C6H4N2)2(H2O)4](O2CC6H4CO2)- 4H2O, has been synthesized and studied by single-crystal X-ray diffraction. It crystallizes in the triclinic space group P1. The crystal structure shows an approximately octahedral coordination environment of the complex with the [Ni(H2O)4(3-NCpy)2] 2+ (3-NCpy is pyridine-3-carbonitrile) cation associated with four free water molecules and hydrogen bonded to a terephthalate dianion [graph set R2 2(8)]. The supramolecular structure of the compound is stabilized by a three-dimensional array of O—HO and O—HN hydrogen bonds, along with – stacked pyridine-3-carbonitrile rings and C—HO interactions.