A blue luminescent binuclear cadmium-orotate coordination polymer: synthesis, crystal structure, and thermogravimetric analysis

Assembly of orotic acid (H-3 Or, 1,2,3,6-tetrahydro-2,6-dioxo-4-pyrimidinecarboxylic) and Cd(NO3)center dot 6H(2)O yielded a coordination polymer, [(Cd(Hor)center dot 2.5H(2)O)(2)](n) (1), which has been characterized by X-ray single-crystal diffraction, TGA, and fluorescence spectra. Single-crystal X-ray structural analyses reveal that 1 is a hydrogen-bonded binuclear Cd-orotate coordination polymer in which both Cd2+ ions have different coordination environments with identical distorted octahedral geometry. Crystal data for 1: monoclinic, space group P2(1)/n, a = 7.0209(10) angstrom, b = 13.974(2) angstrom, c = 17.541(3) angstrom, beta = 98.842(2)degrees, V = 1700.5(4) angstrom, Z = 4, R1 = 0.0269, wR2 = 0.0612, theta(max) = 25.960. The emission spectrum of the Cd-complex recorded with 265 nm excitation wavelength reveals the complex has strong blue luminescence with the peak maximum 420 nm (2.95 eV) as a result of the n-pi* and pi-pi* transitions on the H-3 Or ligand. GRAPHICS