THERMAL-DECOMPOSITION KINETICS .17. KINETICS AND MECHANISM OF THERMAL-DECOMPOSITION OF BIS(ETHYLENEDIAMINE)COPPER(II) HALIDE MONOHYDRATE

The thermal decomposition studies of bis(ethylenediamine)copper(II) chloride monohydrate and bis(ethylenediamine)copper(II) bromide monohydrate were carried out using thermogravimetry (TG), derivative thermogravimetry (DTG) and differential thermal analysis (DTA). The kinetics and mechanism of the dehydration and the deamination stages of both the complexes were evaluated. The different stages of decomposition were identified from TG, DTG, and DTA. The intermediate and residue analysis done using optical microscopy and X-ray diffraction showed the formation of CuCl and CuBr at about 450-degrees-C and copper as fine linear wires at about 700-degrees-C. The kinetic parameters for the dehydration and the deamination reactions were evaluated from the TG and DTA curves using four integral methods. For both the complexes the dehydration and the deamination processes follow the mechanism of random nucleation with the formation of one nucleus on each particle (Mampel equation). The heat of reaction for each stage of decomposition was determined using DTA.