Synthesis and crystal structure of two zinc-containing complexes of triethanolamine

Abstract

Two new zinc-containing complexes [Zn2(TEA)(C6H5COO)3] (1) and ([Zn(TEA)(H2O)2]SO4)·H2O (2) were synthesized and characterized by IR spectroscopy, elemental analysis, DSC and TG analysis. Their structure was determined by single-crystal X-ray diffraction. In the binuclear, mixed-ligand [Zn2(TEA)(C6H5COO)3] complex, one zinc atom is six-coordinated by nitrogen and three oxygen atoms of tetradentate triethanolamine (TEA) and two oxygen atoms of two different benzoate ligands, forming the distorted octahedron of the ZnNO5 type. The second zinc atom is five-coordinated, forming the distorted trigonal bipyramid. Two zinc atoms are bridged by two carboxylate groups of two benzoate ligands and one oxygen atom of the deprotonated hydroxyethyl group of TEA. Cationic complex 2 consists of [Zn(TEA)(H2O)2]2+ cations and SO42− anions. The coordination polyhedron around the zinc atom corresponds to a distorted octahedron (ZnNO5 type). The TEA ligand is tetradentately coordinated to the cation, forming three chelate rings. The coordination sphere of the Zn cation is completed by two aqua ligands.