Kinetic and mechanistic studies involving the nitroso group

Abstract

Nitrosation is a major area of work in physical organic chemistry, which is of interest as an academic study in its own right but is also of wider interest owing to the carcinogenicity of some N-nitroso compounds. The present work has boon concerned with some of the reactions involving the nitroso group at nitrogen, oxygen and sulphur sites,, The approach has been to determine rate constants for the reactions involved and to use these to establish mechanism and relative reactivities. The work covers four areas; (i) Denitrosation of N-nitrosoamines in solvents other than water It has been found that some solvents do enhance the rate of denitrosation relative to that in water. (ii) Diazotisation of aromatic amines. This reaction proceeds via the formation of an N=nitroso intermediate. The relative reactivities of a number of nitrosating species in this reaction have been established. (iii) Nitrosation of thiols. Few kinetic studies have been made of S-nitrosation (compared to N-nitrosation), here the rates of reaction of some tbiocarboxylie acids toward nitrosating species have been determined and comparisons with other substrates drawn. (iv) Nitrosation of alcohols. The kinetics of nitrosation of alcohols has already been studied in some detail and here the aim has been to use this reaction to throw some light on the nature of the intermediate in aqueous nitrosation.