beta-cyclodextrin-micelle mixed systems as a reaction medium. Denitrosation of N-methyl-N-nitroso-p-toluenesulfonamide

The kinetics of the acid hydrolysis of N- methyl-N- nitroso-p- toluenesulfo namide (MNTS) were studied in media containing different cationic micellar aggregates (lauryltrimethylammonium bromide, tetradecyltrimethyl-ammonium b romide and cetyltrimethylammonium chloride) and beta -cyclodextrin (beta -C D). The results were interpreted in terms of the pseudo-phase model. The mo del takes into account the formation of both beta -CD-surfactant and beta - CD-MNTS complexes. The presence of beta -CD has no effect on existing micel les but raises the cmc. Complexation of surfactant by beta -CD makes the cm c dependent on beta -CD concentration because the cme is now the sum of the concentrations of free and complexed surfactant when micelles begin to for m. At surfactant concentrations above the cmc, competition between the mice llization and complexation processes leads to the existence of a significan t concentration of free cyclodextrin. Copyright (C) 2000 John Wiley & Sons, Ltd.