Kinetic studies in mass spectrometry—VI: The [M ? CH3] reaction in substituted ethylbenzenes

The M] → M ? CH₃] reaction in a series of m- and p-X substituted ethylbenzenes has been studied by wide range electron energy kinetics and metastable ion characteristics techniques. By this approach, qualitative measures of activation evergy differences between XC₆H₄CH₂]⁺ ions derived from m- and p-X isomer substrates have been secured, for both their formation and further decomposition. These evergy differences are consistent with (but do not prove) ion structures that have been suggested by previous work in this area, involving the use of isotope labeling, and ionization and appearance potential methods.