Crystal Structure and Photoluminescent Properties of Two Cadmium(II) Complexes with Orotic Acid

Assembly of orotic acid (2,6-dioxo-1,2,3,6-tetrahydropyrimidine-4-carboxylic acid, H3dtpc) and Cd(OAc)2·2H2O gave rise to two complexes [Cd2(H2dtpc)2(H2O)6] (I) and [Cd(H2dtpc)(bpy)(H2O)]n (II) (bpy = 2,2′-bipyridine). Complex (I) and (II) have been characterized by X-ray single crystal diffraction, IR, PXRD, TGA and fluorescence spectra. Structural analyses reveal that (I) is a binuclear structure, and complex (II) possesses a one-dimensional infinite zig-zag chain architecture and the chains are further assembled into 2D supramolecular network by strong hydrogen bonding interactions. Crystal data for (I): Monoclinic, space group P2(1)/n, a = 9.3221(19) A, b = 6.6315(13) A, c = 15.322(3) A, β = 102.31(3)°, V = 925.4(3) A3, Z = 4, R1 = 0.0269, and wR2 = 0.0604; for (II): Monoclinic, space group P2(1)/c, a = 9.9880(2) A, b = 14.5085(2) A, c = 11.6957(2) A, β = 107.976(2)°, V = 1612.10(5) A3, Z = 4, R1 = 0.0234 and wR2 = 0.0554. The Cadmium ions are joined by orotate ligands in different direction to complete a zig-zag chain, which are further assembled by the intermolecular hydrogen bonding to form a two-dimensional structure with remarkable thermal stability.