Syntheses, crystal structures and thermal properties of six coordination polymers based on 2-(p-methylphenyl)-imidazole dicarboxylate.

Through solvothermal reactions of 2-(p-methylphenyl)-1H-imidazole-4,5-dicarboxylic acid (p-MePhH3IDC) with transition-metal ions, six coordination polymers [Pb2(p-MePhHIDC)(p-MePhH2IDC)2(phen)2]n (phen = 1,10-phenanthroline) (), [Pb(p-MePhH2IDC)2]n (), [Cd3(p-MePhHIDC)2(p-MePhH2IDC)2(H2O)2]n (), {[Cd(p-MePhHIDC)(H2O)]4·H2O}n (), {[Cd2(p-MePhHIDC)2(4,4'-bipy)]·4H2O}n (4,4'-bipy = 4,4'-bipyridine) () and [Mn3(p-MePhHIDC)2(p-MePhH2IDC)2(4,4'-bipy)]n () have been synthesized successfully. X-ray single-crystal analyses show that polymers have rich structural chemistry ranging from one-dimensional (), two-dimensional () to three-dimensional polymers (, , and ). In these polymers, the p-MePhH3IDC ligand shows flexible coordination modes tuned by different synthetical conditions, including the addition of coligands, temperature, pH value and so on. Furthermore, the polymers have been investigated by solid-state ultraviolet spectra and thermogravimetric analyses.