Synthesis,Crystal Structure and Thermal Behavior of a New 2D Barium（Ⅱ） Coordination Polymer with 1H-benzimi-dazole-5,6-dicarboxylate as the Single Ligand

The self-assembly of 1H-benzimidazole-5,6-dicarboxylic acid with barium chloride under hydrothermal conditions afforded a new 2D coordination polymer,[Ba2(L)(HL)Cl]n(1,L = 1H-benzimidazole-5,6-dicarboxylate),which was characterized by elemental analysis,infrared spectroscopy,thermogravimetric analysis,and single-crystal X-ray diffraction.Compound 1 is of monoclinic system,space group P21/c with a = 10.0145(6),b=25.6854(15),c=7.3116(4) ?,β = 99.4980(10)°,V = 1854.95(19)3,C18H9Ba2ClN4O8,Z = 4,Mr=719.42,Dc = 2.576 g/cm3,μ(MoKα) = 4.427 mm-1,F(000) = 1352,the final R = 0.0202 and wR=0.0465 for 3051 observed reflections with I > 2σ(I).It exhibits an interesting two-dimensional network structure and high thermal stability(up to 420 ℃).