Dephosphorylation in Zwitterionic Micelles of Amine Oxide or Betaine Sulfonate Surfactants

Article abstract of DOI:10.1021/jo00226a020

First-order rate constants for reaction of OH^- with p-nitrophenyl diphenyl phosphate (p-NPDPP) go through minima with increasing concentrations of dodecyldimethylamine oxide (DDMAO) or N-hexadecyl-N,N-dimethyl-3-ammonio-1-propanesulfonate (SB3-16).The initial sharp decrease is ascribed to surfactant binding to submicellar aggregates and fully formed zwitterionic micelles appear to bind OH^- weakly, and this binding is decreased by added inert anions.Reactions of bound substrate is faster in micelles of DDMAO than those of SB3-16 because the amine oxide moiety participates in the reaction, probably as a nucleophile.