Thermal behaviour of tri(O,O'-diisopropyldithiophosphate)cobalt(III), Co(dptp)3 and bis (O,O'-diethyldithiophosphate)nickel(II), Ni(detp)2 and its adducts with pyridine, Ni(detp)2(py)2 or 4-methylpyridine, Ni(detp)(mpy)2 in a dynamic nitrogen atmosphere was investigated by TG-DTG and DSC techniques, which showed a medium endothermic peak for
the evolution process of pyridine(or 4-methylpyridine) and a strong exothermic peak for that of O,O'-diethyldithiophosphate.
The thermal stability and decomposition patterns for these compounds were compared and interpreted in terms of structural
features such as bond character and steric effects. The kinetic parameters and mechanisms of every decomposition stage involved
for all these complexes were obtained employing the non-isothermal kinetic analysis method suggested by Malek et al., which
showed the kinetics mechanism for pyrolysis of pyridine(or 4-methylpyridine) is an S-B empirical model with lower activation
energy, while that of O,O'-dialkyldithiophosphate is a diffusion model. These results are in accord with the fact that two
ligands are of different type.