Studies on electron transfer reactions: Reduction of heteropoly 10-tungstodivanadophosphate by thioglycolic acid in aqueous medium

Journal of Chemical Sciences

Kasi Rajasekaran1¹  Kandasamy Venkateshwari¹  Natarajan Mariselvi¹  Arunachalam Sarathi¹  Ponnusamy Sami¹ 

[1] Post Graduate Department of Chemistry, V.H.N. Senthikumara Nadar College, Virudhunagar 626 001$$

关键词: Thioglycolic acid;    heteropoly 10-tungstodivanadophosphate;    outer sphere electron transfer reactions;    Marcus theory;    Rehm-Weller relationship.;   

DOI  :  

来源: Indian Academy of Sciences

【 摘 要 】

Rates of electron transfer reaction of thioglycolic acid with vanadium(V) substituted Keggintype heteropolyanion, [PVVVVW10O40]5-, in acetate-acetic acid buffers have been measured spectrophotometrically at 25°C. The order of the reaction with respect to substrate and oxidant is unity. The reaction shows simple second order kinetics at constant pH. The rate of the reaction increases with increase of pH of the medium. The mono-anion HSCH2COO- and di-anion -SCH2COO- are found to be the reactive species. Rate constants for mono-anion and di-anion are evaluated from rate law derived from the mechanism. By applying Rehm-Weller relationship, self exchange rate constant for the -SCH2COO-/S$^{ullet}$ CH2COO- couple was evaluated as 3.3 × 103 dm3 mol-1 s-1 at 25°C.

【 授权许可】

Unknown