Limitations of the Pseudophase Model of Micellar Catalysis. The Dehydrochlorination of 1,1,1-Trichloro-2,2-bis(p-chlorophenyl)ethane and Some of Its Derivatives

Article abstract of DOI:10.1021/j100207a030

The dehydrochlorination of 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane (DDT), 1,1-dichloro-2,2-bis(p-chlorophenyl)ethane (DDD), and 1-chloro-2,2-bis(p-chlorophenyl)ethane (DDM) with hydroxide ion was studied in the presence of hexadecyltrimethylammonium bromide (CTAB) micelles at 25.0 deg C.The experimental results indicate that there is good agreement between the experimental results and theoretical models of micellar catalysis for (OH) in the range of 1E-3-1E-2 M.For (OH) values higher than 1E-2 M, the pseudophase model fails there is a significant deviation between the theoretically calculated and observed values of the pseudo-first-order rate constant.The experimental results can be explained by considering an additional reaction pathway across the micellar boundary, in which hydroxide ion in the aqueous phase reacts directly with the organic substrate in the micelle.This additional reaction pathway is probably of a phase transfer catalysis type.