Coordination properties of ethyl bis(pyridin-2-ylmethyl)phosphate ligand with copper and zinc chloride. X-ray crystal structure of Cu(II) complex

Abstract

A new ethyl bis(pyridin-2-ylmethyl)phosphate (2-bis(pm)Ope) ligand has been synthesized and used for synthesis of copper(II) and zinc(II) complexes of the formula [MCl2(2-bis(pm)Ope)] [M=Cu(II), Zn(II)]. Despite having the same general formula, Cu(II) and Zn(II) complexes are not isostructural. The Zn(II) complex is four coordinated (MCl2N2) forming probably tetrahedral structure whereas the Cu(II) complex of distorted square pyramidal geometry is five coordinated (MCl2ON2). The later compound not only coordinates by two nitrogen atoms of pyridine rings but also by the oxygen atom of pyridin-2-ylmethoxyl residue. The compound (2-bis(pm)Ope) has been obtained as the product of diethyl (pyridin-2-ylmethyl)phosphate’s (2-pmOpe) transestrification. The compounds have been identified and characterized by IR, far-IR, 1H NMR, 31P NMR and elemental analyses. The crystal structure of copper(II) complex i.e. [CuCl2(2-bis(pm)Ope)] has been determined by the X-ray diffraction method. The low temperature magnetic study reveals significant antiferromagnetic interaction between copper centers through the H-bond system.