Micellar catalysis on the redox reaction of glycolic acid with chromium(VI)

Chromium(VI) oxidation of glycolic acid in the absence and presence of cety ltrimethylammonium bromide (CTAB) and cetylpyridinium bromide (CPB) followe d the same mechanism as shown by kinetic study. The reaction followed secon d-order kinetics, first-order in each reactant. The oxidation is strongly c atalyzed by manganese(II) and cationic micelles or CTAB or CPB. The catalyt ic effect of micelles can be fitted to a model in which the reaction rate d epends upon the concentration of both reactants in the micellar pseudophase . Some added inorganic salts (NaCl, NaBr, NaNO3, and Na2SO4) reduce the mic ellar catalysis by excluding glycolic acid from tile reaction site The reac tivity of glycolic acid towards chromium(VI) has been discussed and also co mpared with those obtained previously for the reaction be tween chromium(VI ) and the reductants oxalic and lactic acids On the basis of the observed r esults. probable mechanisms have been proposed. (C) 2001 John Wiley & Sons, Inc.