Thermokinetic studies of organotin(IV) carboxylates derived from para-methoxyphenylethanoic acid

Thremogravimetric (TG) studies of a new series of organotin(IV) carboxylates of the general formula R_nSnL_4-n (where R = CH₃, C₂H₅, C₄H₉, C₆H₅, C₆H₁₁ and C₈H₁₇, n = 2, 3 and L = para-methoxyphenylethanoate anion) have been carried out. Horowitz and Metzger method has been used to calculate thermokinetic parameters. It has been found that diorganotin dicarboxylates have larger activation energy than those of corresponding triorganotin carboxylates. Furthermore, the activation energy, Gibb’s free energy, entropy and enthalpy of diorganotin compounds shows the following trend, (CH₃)₂SnL₂ < (C₂H₅)₂SnL₂ < (C₄H₉)₂SnL₂ < (C₈H₁₇)₂SnL₂. This is attributed to steady increase in chain length of the alkyl groups. However, triorganotin compounds do not show such behavior.