Syntheses,Crystal Structure and Luminescent Property of 1D Chain-Like Coordination Polymer [Pb_2(C_8H_7O_2)_4(H_2O)_2]_n

The coordination polymer [Pb2(m-ta)4·(H2O)2]n (H m-ta=m-toluic acid) was synthesized under hydrothermal conditions and characterized via IR, CHN elemental analysis, and single crystal X-ray diffraction analysis. The complex belongs to monoclinic system, space group P21/n with a=0.717 45(3) nm, b=4.274 5 (2) nm, c=1.071 26(5) nm, β=90.765 0(10) °, V=3.285 0(3) nm3, Z=4, Dc=2.004 g·cm-3, F(000)=1 872, μ=10.291 mm-1, R1=0.035 2, wR2= 0.065 1. The asymmetric unit contains two Pb Ⅱ atoms, four m-ta ligands and two water molecules. Each Pb Ⅱ is heptacoordinated, belonging to the hemidirected coordination geometry. The Pb atoms are bridged through the carboxylate O atoms, leading to a central Pb2O2 core. The coordinating water molecules and carboxylate O atoms are involved in extensive O-H…O hydrogen-bonding interactions. The complex has an extended chain structure and the chains are assembled by hydrogen bonds and π-π interactions (centroid-centroid distance=0.362 46 nm) into a three-dimensional supramolecular structure. The luminescent property in solid state of complex has been further studied and discussed.