Dissociation Dynamics of Energy-Selected C5H10(1+) Ions

Article abstract of DOI:10.1021/ja00323a016

The fragmentation reactions of six C5H10(1+) isomers loosing CH3 and C2H4 have been investigated by using the photoelectron photoion coincidence (PEPICO) technique.Except for the 2-methyl-2-butene ion dissociation all precursors exhibit a two-component decay indicating that dissociation occurs from at least two distinct forms of molecular ions.The observation is rationalized in terms of competition between dissociation from the original ion structure and isomerization to a lower energy isomer subsequently decomposing at a slower rate.The latter isomer is identified as the 2-methyl-2-butene molecular ion.The comparison of the measured absolute rates with those predicted by the statistical theory (RRKM/QET) suggests that the transition-state switching model is necessary for a quantitative agreement.