Kinetics of the reversible hydration of 1,3-dichloroacetone catalysed by micellar aerosol-OT in carbon tetrachloride

Abstract

The kinetics of the reversible hydration of 1,3-dichloroacetone (DCA) by Aerosol-OT (AOT) solubilized water or D₂O, have been studied in carbon tetrachloride. In the presence of the surfactant, rate constants for hydration or dehydration are faster than those in water–dioxan and/or D₂O–dioxan mixtures. Rate enhancements range from 1 808 to 111 for hydration by water–AOT, and from 1 619 to 124 for hydration by D₂O–AOT. The corresponding ratios for the dehydration reaction range from 508 to 64 and 1 788 to 104 for water–AOT and D₂O–AOT, respectively. Equilibrium constants for hydration are also higher in the presence of AOT than those in water– or D₂O–dioxan mixtures. The results are discussed in terms of the unique properties of AOT solubilized water, as well as participation of the surfactant head-group in the slow water attack.