Kinetics and mechanism of thermolysis of hexammine metal perchlorates

Abstract The thermal decomposition studies on four transition metal hexammine perchlorates, viz. [Cu(NH3)6](CIO4)2, [Co(NH3)6](CIO4)2, [Ni(NH3)6](CIO4)2 and [Zn(NH3)6](CIO4)2. have been carried out using Thermogravimetry (TG), derivative thermogravimetry (DTG) and explosion delay (DE) measurements. Although, the kinetics of thermolysis of these complexes were evaluated by fitting isothermal TG data in nine mechanism-based kinetic models but the contracting area (n=2) and contracting cube (n=3) give the best fits. It has been observed that deammination takes place at lower temperatures and ammine metal perchlorates and/or metal perchlorates are formed as intermediates which decompose to metal oxides at higher temperatures. The decomposition pathways for hexammine metal perchlorates have also been suggested.