Secondary α-deuterium kinetic isotope effects in the decomposition of simple α-acetoxydialkylnitrosamines: Nitrosiminium ion intermediates

Article abstract of DOI:10.1016/S0040-4020(97)00687-X

Secondary α-deuterium kinetic isotope effects for the pH independent decay of two (N-nitrosoalkylamino)methylacetates (4) and two (N-nitrosoalkylamino)propyl acetates (5) have been determined at 52°C in aqueous solution, ionic strength 1 M. In all cases the isotope effects are k(obsd)(H)/k(obsd)(D) ~1.1-1.2 (per hydrogen). It is concluded that the direction and magnitude of the isotope effects are inconsistent with mechanisms involving rate limiting reaction at the carbonyl group; and, are consistent with the formation of N-nitrosiminium ions in, or prior to, the rate limiting step.