Thermal decomposition of mixed ligand complexes of manganese(II), copper(II), zinc(II) and cadmium(II) containing N-(2-hydroxyethyl)-ethylenediamine and oxalate

Abstract

The kinetics of the thermal decomposition of mixed ligand complexes of Mn(II), Cu(II), Zn(II) and Cd(II) containing N-(2-hydroxyethyl)-ethylenediamine and oxalate have been studied employing thermogravimetry (TG) and differential scanning calorimetry (DSC). The activation energy of the first order reaction in which the complex loses one molecule of the amine was calculated using the equations of Dharwadkar and Karkhanavala (modified Horowitz and Metzger equation) and Coats and Redfern from the TG data, and Swarin and Wims from the DSC data. These values are 23.45, 16.83, 19.62 and 19.25 kcal mole −1 respectively, using the method of Dharwadkar and Karkhanavala. Infrared spectral studies of these complexes were carried out to determine the coordinating behaviour of the ligand in these complexes.