Synthesis and Equilibrium Studies of the Metal Complexes of Heterocyclic Azo Compounds

Abstract

The formation equilibria of the complexes of some transition metal ions and triazolylazonaphthol (TAN) have been investigated by a potentiometric technique. The stepwise formation constants of the complexes formed in solution were calculated using the non-linear least-squares computer program MINIQUAD. The concentration distribution of the complex species was resolved. Complexes of Cu(II), Co(II), Ni(II), Cd(II), Zn(II), UO₂(VI) and Pd(II) have been synthesised and characterized by elemental analyses, electrolytic conductance, spectral and magnetic measurements. The ligand forms 1:2 complexes (metal ion : ligand), except for Pd(II), where 1:1 complex is formed. The Ni(II) and Co(II) complexes are octahedral and of the general formula ML₂, where L is the uninegatively charged tridentate ligand (ONN donor set). The Cu(II) complex is binuclear with a ligand-bridged structure.