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5325946 
Journal Article 
SN2 REACTIONS OF A SULFONATE ESTER IN MIXED CATIONIC NONIONIC MICELLES 
Bunton, CA; Wright, S; Holland, PM; Nome, F 
1993 
1 
Langmuir
ISSN: 0743-7463
EISSN: 1520-5827 
9 
1 
117-120 
English 
WOS:A1993KJ10100027 
Addition of the nonionic surfactant C10E4 (n-C10H21(OCH2CH2)3OCH2CH2OH) to aqueous cetyltrimethylammonium bromide ((CTA)Br) inhibits the micellar-mediated reaction of Br− with methyl naphthalene-2-sulfonate (MeONs) under conditions in which MeONs is essentially fully micellar-bound. Fractional micellar ionization, a, of (CTA)Br is increased by C10E4, and the loss of Br− from the micellar surface is a major cause of the inhibition. First-order rate constants at the micellar surface are proportional to the mole ratio of bound Br− to total micellized surfactant, and second-order rate constants in the micellar pseudophase are very similar to those at the surface of a (CTA)Br micelle. These second-order rate constants are almost unaffected by incorporation of C10E4 or a moderately hydrophobic alcohol in the micellar pseudophase, probably because reaction occurs preferentially adjacent to cationic head groups at the micellar surface. © 1993, American Chemical Society. All rights reserved.