Syntheses, structures and chemical sensing properties of three complexes with mixed ligands of carboxylate and bipyridine.

Three mixed-ligand coordination polymers, [Cu(oda)(2,2′-bipy)]2 (1), Ni2(oda)2(4,4′-bipy)·DMF (2), and [{Ni(oda)(H2O)2}2(μ-4,4′-bipy)]·2H2O (3) were synthesized and characterized. Complex 1 features a 1D chain via intermolecular π-π interactions. Complex 2 is a novel 3D microporous coordination polymer with 1D polarized channels. Complex 3 forms a 3D network via extensive hydrogen bonding interactions. Thermogravimetric analyses have been studied. The chemical sensing properties have been investigated in situ by quartz crystal microbalance (QCM). Complex 1 has a good sensitivity to toluene, complexes 2 and 3 have exceptionally high selectivity and sensitivity to water over organic solvents.