Abstract
New complexes of Co(II), Ni(II) and Cu(II) with di(3-chloro-4-methylphenyl) carbazone having the general formula [M(DCMPC) 2 ] [where M=Co(II), Ni(II) or Cu(II); DCMPC=di(3-chloro-4-methylphenyl)carbazone] have been synthesized and characterized by elemental analyses, magnetic moment measurements, Uv-Vis., IR, EPR and thermal studies. The DCMPC behaves as a bidentate monoanionic ligand coordinating through the ketonic oxygen and azo nitrogen. The interpretation, mathematical analyses of the thermoanalytical data (TG and DTA) and evaluation of kinetic parameters are presented in this communication. The energy of activation for the two clear-cut steps of decomposition for all the complexes are compared by employing the Freeman-Carroll equation, the integration method using the Coats-Redfern equation and the approximation method using the Horowitz-Metzger equation. The Coats-Redfern equation was extended to evaluate other kinetic parameters such as pre-exponential factor and entropy of activation.