Polymeric copper(II)-orotato complexes, [(C5H2N2O4)Cu(H2O)2]n

The compound [(C₅H₂N₂O₄)Cu(H₂O)₂]_n has been synthesized and its structure determined at room temperature. The primary coordination sphere at the Cu ion is square planar with the orotate dianion coordinating at the metal through heterocyclic nitrogen atom and adjacent oxygen of the carboxylate group, the remaining coordination sites are occupied by two water molecules. The orotate dianion is tricoordinated to one copper via N₁ and one oxygen of the carboxylato group and to another copper atom via the other oxygen of the carboxylato group. The coordination at copper is extended to five by the other oxygen of the carboxylate group of another orotate molecule. Thus, the molecules are associated to form chains, the carboxylato group acting as a bridge between the metal ions, the orotato-group being tridentate. The title compound crystallizes in the monoclinic space group. P2₁/n₁ with a = 9.515(5), b = 6.925(2), c = 11.861(6) Å, = 95.285(9)°, D_calc = 2.17 g cm^–3, and z = 4.