Autocatalyzed oxidation of d‐glucitol by alkaline copper (III) periodate complex: A kinetic and mechanistic approach

Abstract

An autocatalyzed oxidation of d‐glucitol (DG) by diperiodatocuprate (III) (DPC) in aqueous alkaline medium at a constant ionic strength of 0.06 mol dm−3 was studied spectrophotometrically. An autocatalysis was observed by one of the products formed, that is, Cu (II). A 1:2 stoichiometry (DG : DPC) exhibited reaction between the DG and DPC in an aqueous alkaline medium. The reaction was of first order in [DPC] when [DPC] < < [DG], while the order with respect to [DG] and [OH−] was less than unity, whereas periodate had retarding effect on the rate of reaction. Ionic strength had a negligible effect on the rate of reaction. The main reaction products were identified by the spot tests and spectroscopic analysis. The product, Cu (II), catalyzed the reaction with a fractional order. A composite mechanism involving uncatalyzed and autocatalyzed reaction paths was proposed. The activation parameters with respect to slow step of the mechanism and also the thermodynamic quantities were determined and discussed.