Syntheses, Crystal Structures and Luminescent Properties of Two New Zinc(II) Complexes Based on Bifunctional Ligand

By using solvothermal method, two novel coordination polymers based on 4-(4-carboxyphen-yl)-1,2,4-triazole (Hcpt) and Zn(II) cations, [Zn(cpt)(OH)](n)center dot H2O (FJU-32) and [Zn(cpt)(atrz)](n) (FJU-33) (Hatrz = 3-amino-1,2,4-triazolate), were synthesized and characterized by single-crystal X-ray diffraction analyses, elemental analyses, FT-IR and powder X-ray diffraction. FJU-32 crystallizes in monoclinic, space group P2(1)/c with a = 3.7441(3), b = 23.0384(19), c = 11.8562(10) angstrom, beta = 99.069(8)degrees, V = 1009.91(15) angstrom(3), D-c = 1.898 g/cm(3), C9H9N3O4Zn, M-r = 288.57, F(000) = 916, mu(MoKa) = 2.439 mm(-1), Z = 4, R = 0.0600 and wR = 0.1306 for 2412 observed reflections (I > 2 sigma(I)), and R = 0.0704 and wR = 0.1349 for all data. FJU-33 crystallizes in monoclinic space group P2(1)/c with a = 12.7483(5), b = 9.9922(3), c = 9.8403(3) angstrom, beta = 100.756(4)degrees, V = 1231.47(7) angstrom(3), D-c = 1.816 g/cm(3), C11H9N7O2Zn, Mr = 336.62, F(000) = 680, mu(CuK alpha) = 2.957 mm(-1), Z = 4, R = 0.0478 and wR = 0.1184 for 2466 observed reflections (I > 2 sigma(I)), and R = 0.0687 and wR = 0.1309 for all data. In FJU-32, Zn(II) is coordinated to three mu(3)-OH groups forming an unprecedented 1D zigzag-like double chain, and the 1D double chains are connected to four neighbouring double chains by the cpt ligands to form an extended 3D porous coordination polymer. In FJU-33, the adjacent [Zn(atrz)] 2D layers are further connected by the cpt ligands via Zn-O coordinated bonds and neighboring interlayer hydrogen-bonding interactions to give rise to an overall 3D pillared layer structure. The neutron triazole group of the cpt ligand has weaker coordination ability than the triazolate anion of atrz ligand. Furthermore, FJU-32 and FJU-33 display high thermal stability up to 300 degrees C, and the solid state fluorescence reveals that two new complexes are potential optical materials.