Permanganate transfer and reduction by D ‐glucose in benzene–cetyltrimethylammoniumbromide aqueous solution: A kinetic study

The addition of cationic surfactant, cetlytrimethylammoniumbromide (CTAB), in benzene and aqueous potassium permanganate solution brought the MnO   − 4from the aqueous phase to the organic phase. At 525 nm, the absorbance of the organic phase increased until it reached a maximum, and then decreased with [CTAB]. The effect of [CTAB] on the reduction of permanganate by D ‐glucose in a benzene–CTAB system has been studied spectrophotmetrically. The observed effect on the rate constant is catalytic up to a certain concentration of CTAB; thereafter, a saturation phenomenon is observed with an increased concentration of CTAB. The oxidation reaction obeyed the first‐order kinetics with respect to the D ‐glucose. On addition of H 2 SO 4 , there was a decrease in the rate constants. There is evidence for the existence of manganese as a water‐soluble colloidal MnO 2 . A detailed mechanism with the associated reaction kinetics is presented and discussed. © 2008 Wiley Periodicals, Inc. 40: 496–503, 2008