Kinetics and thermodynamics of oxidation of some thio acids by tripropylammonium fluorochromate in N, N-dimethyl formamide and acetic acid mixture

Abstract

Kinetics and mechanism of oxidation of thioglycolic acid (TGA). Thiolactic acid (TLA) and thiomalic acid (TMA) by tripropylammonium fluorochromate (TriPAFC) have been studied in N, N-dimethyl formamide (DMF). The reaction is first order with respect to TriPAFC and thioacids (TA). p-Toluene sulfonic acid (TsOH) is used as a source of hydrogen ions. The reaction is acid catalyzed. The hydrogen ion dependence has the form: kobs = a + b [H+]. The reaction has been studied in different percentage of DMF–acetic acid mixture. The effect of dielectric constant of the medium indicates the reaction to be of ion–dipole type. Various thermodynamic parameters for the oxidation have been reported and discussed along with the validity of isokinetic relationship. A suitable mechanism has been proposed.

Keywords

• Thioacid
• Tripropylammonium fluorochromate
• Kinetics
• Oxidation