SYNTHESIS AND EQUILIBRIUM STUDIES OF THE METAL-COMPLEXES OF HETEROCYCLIC AZO-COMPOUNDS

The formation equilibria of the complexes of some transition metal ion s and triazolylazonaphthol (TAN) have been investigated by a potentiom etric technique. The stepwise formation constants of the complexes for med in solution were calculated using the non-linear least-squares com puter 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 ele mental analyses, electrolytic conductance, spectral and magnetic measu rements. The ligand forms 1:2 complexes (metal ion : ligand), except f or Pd(II), where 1:1 complex is formed. The Ni(II) and Co(II) complexe s are octahedral and of the general formula ML(2), where L is the unin egatively charged tridentate ligand (ONN donor set). The Cu(II) comple x is binuclear with a ligand-bridged structure.