Poly[1,4-bis(4-pyridylmethyl)piperazinediium [[tetraaquacobaltate(II)]- #956;-pyromellitato- #954;2O1:O4] dihydrate]

In the title compound, {(C16H22N4)[Co(C10H2O8)(H2O)4]·2H2O}n, the octahedrally coordinated CoII atom is situated on an inversion center and possesses four aqua ligands. The Co atoms are linked into an anionic coordination polymer chain by bis-monodentate pyromellitate ligands. The chain motifs are connected into a supramolecular layer by hydrogen bonding mediated by uncoordinated water molecules. Charge balance is provided by doubly protonated bis(4-pyridylmethyl)piperazine units, which are anchored to the coordination polymer chain motifs by N—H...O hydrogen bonding.