The mechanism of the decomposition of the entitled compounds and their complexes is studied. Adenine, its Schiff base of salicylaldehyde,
and its azo resorcinol derivatives are ended with carbon. However, oxalonitrile compound is appeared as a final product for
adenine acetylacetone and an intermediate for adenine. The thermodynamic parameters of the decomposition reaction were evaluated
and discussed. The change of entropy values, ΔS#, showed that the transition states are more ordered than the reacting complexes. The thermal processes proceed in complicated
mechanisms where the bond between the central metal ion and the ligands dissociates after losing small molecules such as H2O, NH3, or HCl. In most cases, the free radical species of the ligands are assigned to exist through decomposition mechanisms. The
copper adenine and nickel salicylaldehyde complexes are ended with the metal as a final product. However, the cobalt adenine,
its acetylacetone, its salicylaldehyde, cadmium and mercury guanine complexes are ended with metal oxides.