Poly[diaqua-μ(3)-4-nitro­phthalato-copper(II)]

In the title complex, [Cu(C(8)H(3)NO(6))(H(2)O)(2)](n), the two carboxyl­ate groups of the 4-nitro­phthalate dianion ligands have monodentate and 1,3-bridging bonding modes, respectively. The Cu atom shows an approximate square-pyramidal coordination as it is bonded to O atoms from the carboxyl­ate groups of three 4-nitro­phthalate ligands and two O atoms of the non-equivalent coordinated water mol­ecules. Other Cu atoms in the coordination polymer are connected into a two-dimensional layer in the ab plane. The layers are aggregated to a three-dimensional structure through inter­layer hydrogen bonding involving an O atom of a nitro group. The whole three-dimensional structure is further maintained and stabilized by intra­layer hydrogen bonds between the O atoms of the carboxyl­ate groups and the coordinated water mol­ecules.