Studies on the formation and decomposition of copper(III) and nickel(III) complexes with macrocyclic ligands containing amide groups

Abstract

The spectral characteristics of 13- and 14-membered C-functionalized macrocyclic dioxotetraamine and the corresponding saturated polyamine copper(II), copper(III) and nickel(III) complexes have been studied. It was shown that C-functionalized substituents, although not coordinating to the metal ion, have significant effects on the spectral properties of their M III complexes. As for copper(II) complexes, substituents increase the in-plane ligand field and decrease the wavelength of the d- d absorption of their complexes. Substituents increase the π-CT wavelength and decrease the absorption coefficients. Rate constants and activation parameters for the oxidation of Cu II complexes by peroxodisulfate and decomposition reactions of copper(III) complexes in aqueous solution were also measured. Activation parameters were shown to be dependent on ligand structure.