EFFECTS OF COPPER(II) MIXED MICELLES ON AUTOOXIDATION OF 3,5-DI-TERT-BUTYLCATECHOL AND HYDROLYSIS OF P-NITROPHENYL DIPHENYLPHOSPHATE

The rates of autooxidation of 3,5-di-tert-butylcatechol and hydrolysis of p-nitrophenyl diphenyl phosphate in various mixed micelles formed from copper(II) surfactants and sodium dodecyl sulphate, cetyltrimethy lammonium bromide and octaethylene glycol monododecyl ether were measu red under the condition which obeys the first-order kinetic law. When compared to the pure copper(II) surfactant alone, the autooxidation ra te of 3,5-di-tert-butylcatechol was found to be significantly increase d in mixed micellar medium where octaethylene glycol monododecyl ether is the co-surfactant. The other two co-surfactants have relatively sm aller effects on the rates as compared to the neutral co-surfactant. I n the hydrolysis of p-nitrophenyl diphenyl phosphate, other than a sma ll increase in rate on addition of small amount of co-surfactant in so me cases, the overall effect of the co-surfactant is to decrease the r ate. Various reasons are presented to account for the observed rate ef fects. (C) 1997 Elsevier Science B.V.