Kinetics of multi-step processes of thermal degradation of Co(II) complex with N-benzyloxycarbonylglycinato Ligand. deconvolution of DTG curves

Abstract

Thermal decomposition of Co(II) complex with N-benzyloxycarbonylglycinato ligand, [Co(N-Boc-gly)2(H2O)4]·2H2O, in non-isothermal conditions occurs in three complex steps. In order to investigate detail kinetics of first two steps, dehydration and ligand degradation, DTG curves were deconvoluted using product of Gaussian and Lorentzian function. It was shown that process of complex dehydration consists of three, while process of ligand fragmentation consist of five elementary steps. For elementary steps the kinetic triplet (Ea, Z and f(α)) was determinated. Kinetic parameters were obtained by application of IKP method. On the basis of Ma'lek's criteria and Šesták-Berggren's method, Šesták-Berggren's model, f(α)=αM(1-α)N was suggested for all elementary steps, while Master plot method and Perez-Maqueda criteria confirmed suggested reaction models. The thermodynamic activation parameters were calculated for process of complex dehydration, and lifetime for first elementary step of the dehydration and ligand degradation processes was estimated.