✦ LIBER ✦

Effects of ionic and non-ionic micelles on rate of hydroxide ion-catalyzed hydrolysis of securinine

✍ Scribed by Nordin H. Lajis; Mohammad Niyaz Khan

Publisher: John Wiley and Sons
Year: 1998
Tongue: English
Weight: 130 KB
Volume: 11
Category: Article
ISSN: 0894-3230
DOI: 10.1002/(sici)1099-1395(199803)11:3<209::aid-poc995>3.0.co;2-t

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✦ Synopsis

The effects of micelles of cetyltrimethylammonium bromide (CTABr), tetradecyltrimethylammonium bromide (TTABr), sodium dodecyl sulfate (SDS) and polyoxyethylene 10 lauryl ether (C 12 E 10 ) on the rates of alkaline hydrolysis of securinine were studied at a constant [ À OH] (0.05 M). An increase in the total concentrations of CTABr, TTABr, SDS and C 12 E 10 from 0.0 to 0.2 M causes a decrease in the observed pseudo-first-order rate constants (k obs ) by factors of ca 2.5, 3, 7 and 4, respectively. The observed data are explained in terms of pseudophase and pseudophase ion-exchange (PIE) models of micelle. The binding constants, K S , of securinine with SDS, C 12 E 10 , CTABr and TTABr micelles are 32.4, 14.8, 22.1, and 9.1 M À1 , respectively. The magnitudes of the second-order rate constants, k M , for the reactions in the micellar pseudophase are negligible compared with the corresponding rate constant, k W , for the reaction occurring in the aqueous pseudophase for CTABr, TTABr, SDS and C 12 E 10 .

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