Thermal decomposition kinetics of some metal complexes of N,N-diethyl-n '-benzoylthiourea

Thermogravimetry (TG) and differential thermal analysis (DTA) were performe d on the complexes with general formula (M(DEBT)(n) (where M=Fe, Co, Ni, Cu or Ru; n=2, or 3 and DEBT=N,N-diethyl-N'-benzoylthiourea). Derivative ther mogravimetric (DTG) curves were also recorded in order to obtain decomposit ion data on the complexes. The complexes of Fe(III), Co(II), Ni(II), Cu(II) and Ru(III) displayed two- or three-stage decomposition patterns when heat ed in a dynamic nitrogen atmosphere. Mass loss considerations relating to t he decomposition stages indicated the conversion of the complexes to the su lfides or to the corresponding metal alone (Cu, Ru, NiS, CoS or FeS). Mathe matical analysis of the TG and DTG data showed that the order of reaction v aried between 0.395 and 0.973. Kinetic parameters such as the decomposition energy, the entropy of activation and the pre-exponential factor are repor ted.