Premicellar/Micellar Inhibition in Alkaline KMnO4Oxidation of Reducing Sugars: A Kinetic Study

An inactive premicellar {Surfactant- } aggregate in case of sodium lauryl sulphate (NaLS, anionic surfactant), cetyltrimethyl ammonium bromide (CTAB, cationic surfactant) and an inactive micellar {Surfactant- } aggregate/complex in case of Triton X-100 (Tx-100, nonionic surfactant) has been observed during the alkaline KMnO4 oxidation of glucose and fructose in micellar medium. The reaction showed a first-order dependence of rate with respect to . The order of reaction in substrate and alkali was found to decrease from unity at higher [Substrate] and [OH–], respectively. An inhibition effect of each surfactant on the rate of oxidation has been observed. A mechanism involving an inactive {Surfactant- } aggregate/complex and consistent with kinetic data has been proposed. The observed rate constants were in the order of which has been explained in terms of electrostatic and hydrophobic forces.