Synthesis and structural characterization of 2D Zn(II), Cd(II), and Co(II) coordination polymers containing 3-chloro-1,2-benzenedicarboxylate and positional isomers of triazole-bipyridine

Abstract

Three compounds, [Zn2L2(4,4′-bpt)2] n (1), [Cd2L2(3,4′-bpt)(H2O)2] n (2) and {[CoL(3,3′-bpt)(H2O)]∙H2O} n (3) (L = 3-Cl-1,2-benzenedicarboxylate dianion, 4,4′-bpt = 1H-3,5-bs(4-pyridyl)-1,2,4-itriazole, 3,4′-bpt = 1H-3-(3-pyridyl)-5-(4-pyridyl)-1,2,4-triazole and 3,3′-bpt = 1H-3,5-bis(3-pyridyl)-1,2,4-triazole), based on three positionally isomeric triazole-bipyridine ligands, were synthesized. Structural analyses of 1–3 reveal diverse 2-D network structures, which are based on different [ML] n (M = Zn, Cd, Co) chains. In the [ZnL] n chains of 1, the carboxylic groups of L connect the adjacent Zn(II) centers with a monodentate bridging coordination mode (μ2-η1 / η1 ). In 2, [CdL] n is a double chain connected by the carboxylic groups of L with μ3-η1 / η2/η2 and μ3-η1 / η1 / η2 bridges. The [CoL] n chains of 3 are formed by the carboxylic groups of L with the μ2-η1 / η2 coordination mode. The powder X-ray diffraction and the thermal stability of 1–3, the luminescent properties of 1 and 2, and the magnetic behavior of 3 have been briefly investigated.