Linkage Isomerism for 4-Methylimidazole and a New Coordination Mode of Pyrazine-2,3 Ligand in {[Cd(pzdc)(4-Mim)(5 2]•1/2H2O}n Coordination Polymer

Abstract

A novel one dimensional coordination polymer of Cd(II)-pyrazine-2,3- dicarboxylate with a new coordination mode of pyrazine-2,3-dicarboxylate ligand (pzdc), {[Cd(pzdc)(4-mim)(5-mim)<inf>2</inf>]•1/2H<inf>2</inf>O} <inf>n</inf> (1) (4(5)-methylimidazole = 4(5)-mim), has been synthesized and characterized by elemental, thermal analysis, IR spectrum and single crystal X-ray diffraction technique. In complex 1, the Cd(II) ion has a distorted octahedral geometry, in which the pzdc moiety acts as a bridging ligand. Linkage isomerism of the coordinated 4(5)-methylimidazole ligand was observed in 1. The two adjacent one-dimensional chains connected by interchain hydrogen bonds among the N-H groups of methylimidazoles and carboxylate oxygens of pzdc, leading to a three-dimensional framework. The hydrogen bonds account for the coexistence of two unique coordination forms of methylimidazoles in the same coordination sphere. © 2010 Elsevier B.V. All rights reserved.