Formation and nucleophilic capture of N-nitrosiminium ions

A study of the solvolysis of a series of (N-nitrosomethylamino)arylmethyl e sters and azides and the products of nucleophilic trapping of the correspon ding N-nitrosiminium ion intermediates in aqueous media, 25 degrees C, ioni c strength 1 M is reported. Structure-reactivity data for the forward and r everse reactions have been obtained. In three cases, the rate constants for reactions of the cations with nucleophiles have been measured directly by laser flash photolysis. The data allow a comparison of the degree to which the N-methyl-N-nitroso functionality enhances cation stability from a therm odynamic and kinetic perspective. It has been possible to deduce that the c arbon basicity of azide ion is less than 1 kcal/mol greater than that of ac etate ion.