Premium
Micellar effect upon the reaction of hydroxide ion with coumarin
Author(s) -
Malpica A.,
Calzadilla M.,
Linares H.
Publication year - 1998
Publication title -
international journal of chemical kinetics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.341
H-Index - 68
eISSN - 1097-4601
pISSN - 0538-8066
DOI - 10.1002/(sici)1097-4601(1998)30:4<273::aid-kin5>3.0.co;2-p
Subject(s) - chemistry , hydroxide , micelle , cationic polymerization , reaction rate constant , pulmonary surfactant , bromide , sodium dodecyl sulfate , inorganic chemistry , sodium hydroxide , ion , organic chemistry , kinetics , aqueous solution , biochemistry , physics , quantum mechanics
Cationic micelles of cetyltrimethylammonium bromide, CTABr, speed attack of hydroxide ion upon coumarin by a factor of c.a‐2, due to a concentration effect. The first‐order rate constants, k obs , at a given hydroxide ions concentration go through maxima with increasing surfactant concentration. The overall micellar effects in these cationic micelles can be treated in terms of the pseudo‐phase ion exchange model. Analysis of the data shows that second‐order rate constant at the micellar surface is smaller than the second‐order rate constant in water. Anionic micelles of sodium dodecyi sulfate, SDS, inhibit the same reaction. © 1998 John Wiley & Sons, Inc. Int J Chem Kinet 30: 273–276, 1998.