The reaction of copper(II) nitrate with the proton-transfer compound piperazinediium pyridine-2,6-dicarboxylate, or (pipzH2)(pydc), in aqueous solution leads to the formation of the title compound, (C4H12N2)[Cu(C7H3NO4)2]4H2O. The title compound is a six-coordinate complex with a distorted octahedral geometry around the central atom. In the crystal structure, a wide range of non-covalent interactions consisting of hydrogen bonding and – stacking connect the various components into a supramolecular structure.
