Hydrothermal Synthesis and Crystal Structure of a Novel Binuclear Cd(Ⅱ) Coordination Polymer Based on 1,2-Benzenedicarboxylate and Imidazole

The hydrothermal reaction of Cd(OAc)2·H2O with 1,2-benzenedicarboxylate(1,2-BDC),imidazole and H2O resulted in the formation of a binuclear polymeric Cd(Ⅱ) complex {Cd2(1,2-BDC)2(Im)4]·(H2O)}n which was then characterized by elemental analyses and single-crystal X-ray diffraction analysis.The crystal is of monoclinic system,space group P21/c with a = 14.6455(3),b = 9.3530(2),c = 23.7838(5) ,β = 106.6290(10)°,C112H104Cd8N32O36,Mr = 3373.47,V = 3121.64(11) 3,Dc = 1.795 g/cm3,F(000) = 1672,μ = 1.428 cm-1 and Z = 1.The final R = 0.0316 and wR = 0.0687 for 5045 reflections with I > 2σ(I).In the title complex,the two Cd(Ⅱ) ions are in different coordination environments with distorted octahedral and pengonal bipyramidal geometries,respectively.Two Cd polyhedra are linked together through one μ2-η1:η1 and one μ2-η1:η2 carboxylate groups from different 1,2-BDC ligands,giving rise to a binuclear Cd(Ⅱ) cluster,and such clusters are connected by bridged 1,2-BDC ligands to form a 2-D structure along the c axis.The inter-and intermolecular hydrogen bonds further connect the 2-D structures into a 3-D supramolecular network.