Permanganate transfer and reduction by D∼glucose in benzene-catyltrimethylammoniumbromide aqueous solution:: A kinetic study

The addition of cationic surfactant, cetlytrimethylammoniumbromide (CTAB), in benzene and aqueous potassium permanganate solution brought the MnO4- from 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 vertical bar CTAB vertical bar, The effect of vertical bar CTAB vertical bar 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 H2SO4, there was a decrease in the rate constants. There is evidence for the existence of manganese as a water-soluble colloidal MnO2. A detailed mechanism with the associated reaction kinetics is presented and discussed. (C) 2008 Wiley Periodicals, Inc.