Specific Anion Binding to Sulfobetaine Micelles and Kinetics of Nucleophilic Reactions

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• 作者：Luisa Marte ; Rosane C. Beber ; M. Akhyar Farrukh ; Gustavo A. Micke ; Ana C. O. Costa ; Nicholas D. Gillitt ; Clifford A. Bunton ; Pietro Di Profio ; Gianfranco Savelli ; Faruk Nome
• 刊名：Journal of Physical Chemistry B
• 出版年：2007
• 出版时间：August 23, 2007
• 年：2007
• 卷：111
• 期：33
• 页码：9762 - 9769
• 全文大小：104K
• 年卷期：v.111,no.33(August 23, 2007)
• ISSN：1520-5207

文摘

With fully micellar bound substrates reactions of OH^- with benzoic anhydride, Bz₂O, and of Br^- with methylnaphthalene-2-sulfonate, MeONs, in micellized sulfobetaines are strongly inhibited by NaClO₄ which displacesthe nucleophilic anions from the micellar pseudophases. Micellar incorporations of ClO₄^- and Br^- are estimatedwith an ion-selective electrode and by electrophoresis, and partitioning of Br^- between water and micelles isrelated to changes in NMR spectral ⁷⁹Br^- line widths. Extents of inhibition by ClO₄^- of these nucleophilicreactions in the micellar pseudophase are related to quantitative displacement of the reactive anions from themicelles by ClO₄^-. The kinetic data are correlated with physical evidence on the strong interactions betweensulfobetaines and ClO₄^-, which turn sulfobetaine micelles anionic and effectively provoke displacement ofOH^- and Br^-.