acid (PSAA) by Cr(VI) in 20% acetonitrile − 80% water (v/v) medium follows overall second order kinetics, first order each with respect to (PSAA) and (Cr(VI)) at constant (H + ) and ionic strength. The reaction is acid catalysed, the order with respect to (H + ) is unity and the active oxidizing species is found to be HCrO3 + . The reaction mechanism involves the rate determining nucleophilic attack
Competitive behavior of nitrogen based axial ligands in the oxovanadium(IV)-salen catalyzed sulfoxidation of phenylmercaptoacetic acid
作者:C. Kavitha、P. Subramaniam
DOI:10.1016/j.poly.2020.114712
日期:2020.10
Abstract The sulfoxidation of twelve phenylmercaptoacetic acids (PMAA) by H2O2 catalyzed by three oxovanadium(IV)-salen complexes, having varied substituents on PMAA and salen with regard to their position, size and inductive effect, has been performed spectrophotometrically in 100% acetonitrile medium. Three nitrogen bases (NB), pyridine (Py), imidazole (ImH) and 1-methylimidazole (MeIm), were used
A paradigm shift in rate determining step from single electron transfer between phenylsulfinylacetic acids and iron(III) polypyridyl complexes to nucleophilic attack of water to the produced sulfoxide radical cation: a non-linear Hammett
Mechanism of oxidative decarboxylation of phenylsulfinylacetic acids (PSAAs) by iron(III) polypyridyl complexes in aqueous acetonitrile medium has been investigated spectrophotometrically. An initial intermediate formation between PSAA and [Fe(NN)3]3+ is confirmed from the observed Michaelis–Menten kinetics and fractional order dependence on PSAA. Significant rate retardation with concentration of
Alteration of electronic effect causes change in rate determining step: Oxovanadium(IV)–salen catalyzed sulfoxidation of phenylmercaptoacetic acids by hydrogen peroxide
作者:C. Kavitha、P. Subramaniam
DOI:10.1016/j.poly.2019.114172
日期:2020.1
) as the active oxidizing species has been evidenced from the appearance of new absorption peak and the initial induction period in the reaction. Introduction of both electron releasing and electron withdrawing substituents in PMAA retard the rate of sulfoxidation. However, substituents in the salen complex followed a different order: acceleration of rate by electron releasing substituents and retardation
Proximal effect of the nitrogen bases in the oxidative decarboxylation of phenylsulfinylacetic acids by oxo(salen)chromium(V) complexes
作者:P. Subramaniam、S. Sugirtha Devi、S. Anbarasan
DOI:10.1016/j.molcata.2014.03.021
日期:2014.8
Oxidative decarboxylation of phenylsulfinylacetic acid (PSAA) and several substituted PSAAs with three oxo(salen)chromium(V) complexes in the presence of nitrogen bases are investigated in 100% acetonitrile medium using spectrophotometric technique. The nitrogenous bases such as imidazole, 1-methyl imidazole and pyridine catalyse the reaction and Michaelis–Menten kinetics is observed with respect to