GAS-PHASE NUCLEOPHILIC DISPLACEMENT-REACTIONS OF NEGATIVE-IONS WITH CARBONYL-COMPOUNDS

The rates of a number of nucleophilic displacement reactions X-+ RCOY → Y-+ RCOX have been studied with pulsed ion cyclotron resonance spectroscopy, where X = F, Cl, CH3O, CN, SH; R = CH3, C2H5, (CH3)3CH, (CH3)3C, C6H5, CF3; Y = Cl, Br. The results suggest that the potential surfaces contain at least two minima separated by a barrier. The kinetic model is analyzed using RRKM theory, which provides an estimate of the barrier height. The estimated stability of the “tetrahedral intermediate” is examined critically in terms of ions of comparable structure. © 1979, American Chemical Society. All rights reserved.