Specific anion binding to sulfobetaine micelles and kinetics of nucleophilic reactions.
With fully micellar bound substrates reactions of OH- with benzoic anhydride, Bz(2)O, and of Br- with methyl naphthalene-2-sulfonate, MeONs, in micellized sulfobetaines are strongly inhibited by NaClO4 which displaces the nucleophilic anions from the micellar pseudophases. Micellar incorporations of ClO4- and Br- are estimated with an ion-selective electrode and by electrophoresis, and partitioning of Br- between water and micelles is related to changes in NMR spectral (79)Br- line widths. Extents of inhibition by ClO4- of these nucleophilic reactions in the micellar pseudophase are related to quantitative displacement of the reactive anions from the micelles by ClO4-. The kinetic data are correlated with physical evidence on the strong interactions between sulfobetaines and ClO4-, which turn sulfobetaine micelles anionic and effectively provoke displacement of OH- and Br-.
CEMIN, Dipartimento di Chimica, Università di Perugia, 06100 Perugia, Italy.
Luisa
L
Marte
Rosane C
RC
Beber
M Akhyar
MA
Farrukh
Gustavo A
GA
Micke
Ana C O
AC
Costa
Nicholas D
ND
Gillitt
Clifford A
CA
Bunton
Pietro
P
Di Profio
Gianfranco
G
Savelli
Faruk
F
Nome