Comparison of reactivities of methyl naphthalene-2-sulfonate, MeONs, and its 6-sulfonate derivative, MeONsS−, toward H2O, OH−, and Br− in water and in cationic micelles of cetyl trialkylammonium surfactants, n-C16H33N+R3X−,R = Me, n-Pr, n-Bu, CTA+, CTPA+, CTBA+, X = OH, Br, and CH3SO3 has been investigated. For reactions in water, the introduction of the negative charge ac- celerates hydrolysis by a factor of ca. 2, but does not affect reactivity of OH− and Br−. For reactions in micelles, the negative charge de-creases values of kM for reactions with water, with OH− and Br− by a factor of ca. 2; differences for the two substrates decrease with bulking the surfactant head group for a reaction with Br− but not for a reaction with OH−.
Micellar SN2 Reaction of Methylnaphtalene-2 sulfonate and its 6-Sulfonate Derivative: Effect of the Negative Charge
BRINCHI, Lucia;DI PROFIO, Pietro;GERMANI, Raimondo;MARTE, Luisa;SAVELLI, Gianfranco;
2001
Abstract
Comparison of reactivities of methyl naphthalene-2-sulfonate, MeONs, and its 6-sulfonate derivative, MeONsS−, toward H2O, OH−, and Br− in water and in cationic micelles of cetyl trialkylammonium surfactants, n-C16H33N+R3X−,R = Me, n-Pr, n-Bu, CTA+, CTPA+, CTBA+, X = OH, Br, and CH3SO3 has been investigated. For reactions in water, the introduction of the negative charge ac- celerates hydrolysis by a factor of ca. 2, but does not affect reactivity of OH− and Br−. For reactions in micelles, the negative charge de-creases values of kM for reactions with water, with OH− and Br− by a factor of ca. 2; differences for the two substrates decrease with bulking the surfactant head group for a reaction with Br− but not for a reaction with OH−.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
