Kinetic study of the decomposition of N-chloramines

Article abstract of DOI:10.1002/(SICI)1099-1395(199607)9:7<447::AID-POC778>3.0.CO;2-X

The decomposition of various N-chloroalkylamines and N-chloroalcoholamines was investigated kinetically at pH 4-12 and in strongly alkaline media. The rate of N-chloramine decomposition increased with increasing pH above pH 10, remained virtually constant over the pH range 7-10 and again increased with decreasing pH in the acidic zone. The results are described by a rate equation involving general base catalysts terms. Experimental evidence suggests that the decomposition of N-haloamines proceeds via an elimination mechanism that yields an imine. This β-elimination process is a non-synchronized concerted mechanism where cleavage of the N-X bond has progressed to a greater extent than that of the C_a-H by the time the transition state is reached, which is therefore 'El-like' (i.e. with a transition state having a certain nitrenium character).