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

Abstract

Thremogravimetric (TG) studies of a new series of organotin(IV) carboxylates of the general formula R n SnL 4-n (where R = CH 3 , C 2 H 5 , C 4 H 9 , C 6 H 5 , C 6 H 11 and C 8 H 17 , 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, (CH 3 ) 2 SnL 2 < (C 2 H 5 ) 2 SnL 2 < (C 4 H 9 ) 2 SnL 2 < (C 8 H 17 ) 2 SnL 2 . This is attributed to steady increase in chain length of the alkyl groups. However, triorganotin compounds do not show such behavior.

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

“…Recently in the material science, the solid state kinetic data obtained from external stimuli, such as thermal activation by thermogravimetry (TG), differential thermal analysis (DTA) and differential scanning calorimetry (DSC) have become highly useful in designing the formulation and characterization of materials and technological processes. [1][2][3][4][5] The thermal properties are expressed in term of various kinetic and thermodynamic parameters that are evaluated on the basis of a well established TG and DSC scans recorded at specific heating rate and atmospheric conditions (under nitrogen, helium, air flow or vacuum). 6 Thermal decomposition of a solid is highly complicated, taking place in the heterogeneous phase system where various stages can be identified on the basis of heat exchanged along with the formation of new solid phase or the knockout of gaseous products.…”