Synthesis and Characterization of a Cobalt Complex with Maleate and Pyridine

A new polymeric cobalt complex [Co(u-male)(py)(H2O)]n (male=maleate; py =pyridine) 1 was prepared by cobalt chloride hexahydrate with disodium maleate and pyridine in an alcohol-aqueous solution. Single-crystal X-ray analysis has revealed that 1 crystallizes in the orthorhombic system, space group Pnma with a=18.001(1), b=7.6001(6), c=7.4731(6) A, V=1022.4(1)A3, Z=4, C9H9CoNO5, Mr=270.10, Dc= 1.755 g/cm3, F(000)=548, μ(MoKa)=1.683 mm-1, S =1.002, the final R=0.0280 and wR=0.0746 for 883 observed reflections with I ＞ 2σ(I). The structure analysis shows an approximate octahedral coordination environment of metal center. The Co(Ⅱ) ions are bridged by maleic anions in a rare tetradentate coordination fashion with a syn-anti coplanar conformation of the carboxyl group, forming a two-dimensional corrugated 2-D structure which is further attached into a three-dimensional framework via non-classical C-H…O interactions between adjacent layers.