Kinetics and Mechanism of SDS Catalyzed Reaction between Ethanol and N-bromobenzamide.

Abstract

A reaction between ethanol and N-bromobenzamide (NBB) in
acidic medium has been found to be catalyzed by an anionic surfactant
SDS. The log (a -x) vs. t curve displays an inflection. i.e.,
slow first stage followed by relatively faster second stage. In both
the stages the reaction follows first order behaviour with respect to
substrate and N-bromobenzamide. The cause of autocatalysis has
been attributed to Br ^- ions, which was further substantiated by the
removal of first stage on initial addition of potassium bromide. The
pre-micellar kinetics has been rationalised in the light of pseudophase
model. The positive cooperativity index has been computed
(n = 1.47). The solvent composition variation and addition of benzamide
have also been studied. On the basis of the various observations
and product characterization, most plausible mechanisms .
have been envisaged.