Mechanistic Investigation of Oxidation of Diclofenac Sodium by Diperiodatocuprate(Iii) Complex in Aqueous Alkaline Medium

Abstract

The kinetics of oxidation of diclofenac sodium (DFS) by diperiodatocuprate(III) (DPC) in aqueous alkaline medium at a constant ionic strength of 0.60 mol dm−3have been studied spectrophotometrically. The reaction showed first-order kinetics in [DPC] and less than unit order with respect to [DFS] and [alkali] and negative fractional order in [periodate]. The reaction between (DFS) and (DPC) in alkaline medium exhibits 1:2 stoichiometry (DFS): (DPC). The ionic strength and dielectric constant did not affect the rate of reaction. The oxidation products were identified by LC-ESI-MS and IR spectral studies. The reaction constants involved in the different steps of the mechanism were calculated. The activation parameters with respect to the slow step of the mechanism were computed and discussed, and thermodynamic quantities were also determined.