Preparation and identification of some metal complexes with new heterocyclic azo dye ligand 2-[2−- (1- Hydroxy -4- Chloro phenyl) azo ]- imidazole and their spectral and thermal studies

Abstract

The preparation and spectral identification of metal complexes for Cr(III), Mn(II), Fe(III), Co(II), Ni(II), Cu(II), Zn(II), Cd(II) and Hg(II) ions with new heterocyclic azo dye as ligand 2-[2−- (1- Hydroxy - 4- Chloro phenyl) azo ]- imidazole (HClPAI) were prepared by reacting adizonium chloride salt solution of 2-amino -4- chloro phenol with imidazole in alkaline ethanolic solution. Azo dye ligand and their metal complexes have been characterized by analytical data, 1H NMR, Mass spectrum, Infrared, Electronic spectral data, XRD, SEM, thermal analysis (TG-DSC-DTG), magnetic susceptibility and molar conductance. The elemental analysis of the metal complexes confirm the stoichiometry of the type [M(L)2] Cl where M = Cr(III), Fe(III), Co(II) and [M(L)2] where M = Mn(II), Ni(II), Cu(II), Zn(II), Cd(II), Hg(II) and L = azo dye ligand. Molar conductance measurements for prepared metal complexes showed 1:1 electrolyte for Cr(III), Fe(III) and Co(III) ions and non-electrolyte the rest metal complexes. The data show that the azo dye ligand behaves a tridentate and coordinates to the metal ion via nitrogen atom of azo group which is the farthest of imidazole molecule, nitrogen atom of azomethine group of heterocyclic imidazole ring and phenolic oxygen. Octahedral environment is suggested for all metal complexes.