Diaquabis(4,4 '-bipyridine-N)bis(dihydrogenphosphato-O)copper(II): blocking of extended metal-ligand coordination by hydrogen bonding

The title compound, [Cu(H2PO4)(2)(C10H8N2)(2) (H2O)(2)], is a mononuclear c omplex in which the Cu atom is square-planar coordinated by two dihydrogenp hosphate anions and two monodentate 4,4'-bipyridine (4,4'-bipy) groups, and by two more distant aqua ligands to complete a distorted octahedral coordi nation. Metal-etal bridging by 4,4'-bipy is blocked by intermolecular hydro gen bonding from the dihydrogenphosphate to the second N atom of 4,4'-bipy. The crystal packing is controlled both by additional hydrogen bonding betw een the aqua and phosphate ligands and by pi -stacking. These hydrogen-bond ing interactions create two-dimensional networks which are connected by the bipyridine ligands.