Cu(II)/Cd(II) coordination polymers based on polycarboxylate and 2-(2-pyridyl)benzimidazole.

Three polycarboxylate coordination polymers containing 2-(2-pyridyl)benzimidazole as co-ligand, [Cu(Bdc)(2-PyBIm)]n (1), [Cu(HBtc)(2-PyBIm)]n (2) and [Cd2(HBtc)2(2-PyBIm)2]n ·; nH2O (3) (H2Bdc = 1,4-benzenedicarboxylic acid; H3Btc = 1,3,5-benzenetricarboxylic acid), have been synthesized and characterized by elemental analyses, IR spectra, TG-DSC and X-ray structural analyses. Complex 1 is a one-dimensional zigzag chain in which the Cu(II) is cis six-coordinated by two chelating carboxyl groups and a 2-PyBIm ligand. Complex 2 is a two-dimensional (4, 4) network in which H3Btc is partially deprotonated. Complex 3 has a three-dimensional framework in which one Cd(II) is six-coordinate and the other is seven-coordinate. All 2-PyBIm groups are neutral, chelating, bidentate ligands in 1-3. These complexes are quite thermally stable. The luminescence of 3 has also been investigated. [ABSTRACT FROM AUTHOR]