Thermal Decomposition Kinetics of Some Di‐ and Triorganotin(IV) Carboxylates Derived from para‐Nitrophenylethanoic Acid

Thermogravimetric (TG) investigations of organotin(IV) carboxylates with the general formula R_mSnL_4−m (where R=CH₃, C₂H₅, n‐C₄H₉, C₆H₅, cyclo‐C₆H₁₁, n‐C₈H₁₇, m=2, 3, and L=para‐nitrophenylethanoate anion) have been performed. Derivative thermogravimetry (DTG) and differential thermal analysis (DTA) techniques, Horowitz‐Metzger method and the fundamental thermodynamic relations are used to evaluate the thermokinetic parameters of each thermal degradation pattern. Results reveal that the thermal stability is functional to Sn C and Sn O bonds. In the case of R₂SnL₂, activation energy, reaction order and pre‐exponential factor associated with the bulk degradation processes increase as the alkane chain length increases. Hence, Oct₂SnL₂ is thermally more stable than Bu₂SnL₂, which in turn is more resistant to thermal dissociation than Et₂SnL₂. The same phenomenon is not observed for R₃SnL compounds because their degradation is highly irregular. Furthermore, R₂SnL₂ has larger values of kinetic parameters than those of corresponding triorganotin(IV) para‐nitrophenylethanotes. Thermodynamic parameters of these compounds also reinforce the above facts.