| Abstract: | The sodium-hydrogen ion exchange constant for the system sodium 1-dodecanesulfonate-hydrochloric acid in aqueous acetonitrile has been determined from the pseudo-phase ion exchange model for surfactant catalytic effects. The results indicate that the micellar system behaves similarly for the aqueous and the aqueous acetonitrile (2.106 M) solvent systems. The influence of substrate molecular structure on micellar catalysis by perfluorooctanoic acid of the hydrolysis of hydroxamic acids (R—CO—NHOH) in aqueous acetonitrile has been explored. Data for substrate structures of fifteen compounds with R=alkyl, aralkyl, alicyclylalkyl, phenylalkyl, alkyl-substituted phenylalkyl, and with chain branching at the α, β, and γ positions are compared. Relative binding constant values indicate that substrates with aromatic groups are less well solubilized in the perfluoro micellar environment than are substrates with saturated groups. There is now evidence for specific micellar effects on the reaction rate as well as general micellar catalysis. © 1997 John Wiley & Sons, Inc. |
