Synthesis, Crystal Structure and Fluorescence Property of a Zinc(Ⅱ) Coordination Polymer with a Theoretical Calculatio

We have designed and synthesized a new luminescent coordination polymer [Zn;（NO;）(NCP);（H;O）;]n·2 nH;O(1, HNCP = 2-（2-carboxyphenyl） imidazo-[4,5-f]-1,10-phenanthroline) under hydrothermal conditions, which has been structurally characterized by single-crystal X-ray diffraction analyses. 1 crystallizes in monoclinic, space group P21/n, with a = 13.7748（3）, b = 19.2651（4）, c = 19.9543（4） ?, β = 95.339（2）o, V = 5272.35（19） ?;, C;H;N;O;Zn;, Mr = 1286.80, Dc = 1.621 g/cm;, Z = 4, μ（Mo Ka） = 2.118, F（000） = 2629, the final R = 0.0598 and w R = 0.1483. In 1, the organic ligand NCP-displays two different bridging modes to connect adjacent Zn（II） ions into a 1 D chain along the c-direction. Photoluminescent analyses reveal that 1 exhibits a strong green emission with a fluorescent lifetime of 5.57 ns. The first-principle calculation results show that the luminescence mainly originates from ligand-centered charge transition.