Assembly, characterization and dye adsorption properties of two transition metal coordination polymers constructed from a flexible bis(pyridyl-tetrazole) ligand

Abstract

Two copper(II)/cobalt(II) coordination polymers formulated as [Co(3-bptzp)(1,4-BDC)(1,4-H₂BDC)_0.5] (1) and [Cu(3-bptzp)(1,4-BDC)] (2) have been hydrothermally synthesized by using a flexible bis(pyridyl-tetrazole) ligand (3-bptzp = 1,4-bis(5-(3-pyridyl)tetrazolyl)propane) and an aromatic dicarboxylic acid (1,4-H₂BDC = 1,4-benzenedicarboxylic acid) as mixed ligands. Both complexes have been characterized by single-crystal X-ray diffraction, elemental analyses, infrared spectroscopy and powder X-ray diffraction. There are two different types of 2D layered network in the structures of both complexes. In complex 1, the 2D layered network is formed by 1,4-BDC anions and neutral 1,4-H₂BDC ligands, while the 3-bptzp ligands bridge the adjacent two Co(II) atoms to form a [Co₂(3-bptzp)₂] ring. In complex 2, adjacent Cu(II) atoms are bridged by 1,4-BDC anions to form a 1D [Cu(1,4-BDC)]_n chain, and then adjacent 1D [Cu(1,4-BDC)]_n chains are further linked together by the 3-bptzp ligands to generate a 2D layered network. The electrochemical behaviors and dye adsorption properties of both complexes have been studied.