Synthesis, Crystal Structures, and Thermal Analyses of Copper(II) and Manganese(II) Mixed-Ligand Coordination Polymers Constructed from Benzimidazole-5,6-dicarboxylic Acid and N-Donor Ligands

The coordination polymers, {[Cu(Hbidc)(2,2'-bpy)(H2O)]center dot 2H(2)O}(n) (1) and {[Mn(Hbidc)(2,2'-bpy)(H2O)(2)]center dot 2H(2)O}(n) (2) (H(3)bidc = benzimidazole-5,6-dicarboxylic acid, 2,2'-bpy = 2,2'-bipyridine), were synthesized in solution and characterized by elemental analysis, IR spectroscopy, thermogravimetric analysis (TGA), and single-crystal X-ray diffraction. Complexes 1 and 2 consist of different 1D chain structures. In both compounds, 2,2'-bpy is chelating in a bidentate manner, whereas the Hbidc ligands in complexes 1 and 2 display chelating-bridging tridentate and bridging bidentate coordination modes. The two complexes are further extended into 3D supramolecular structures through O-H center dot center dot center dot O and N-H center dot center dot center dot O hydrogen bonds. The thermal stabilities of complexes 1 and 2 were studied by thermogravimetric analyses (TGA).