Insights into the C4H8+· potential energy surface: Fourier transform ion cyclotron resonance studies of ion-molecule reactions of D-labeled partners

Abstract

Reactions of [ethylene]+· with ethylene and of [acetylene]+· with ethane were studied by Fourier transform ion cyclotron resonance spectrometry using labeled reactants. The results confirm and clarify the different steps of the mechanism proposed previously and elaborated with other methods. The [[acetylene]+·, ethane] system can either dissociate to give the ethyl cation product, or isomerize into [[ethylene]+·, ethylene]. The latter system can either dissociate to yield ionized ethylene or convert into ionized but‐2‐ene, which undergoes a complete H‐exchange prior to dissociation, leading to methyl radical, hydrogen radical and ethylene losses. The transfers of labeled atoms and the existence of H‐exchange prior to formation of the products were used as a probe to check the different steps of the mechanism. The influence of the initial energy of the system on the reaction pathway is discussed. Copyright © 1999 John Wiley & Sons, Ltd.

10 Gas phase organic ion–molecule reaction chemistry

“…Thissen et al 41 have used an FT-ICR to investigate the reactions of the ethene radical cation with ethene and of the ethyne radical cation with ethane. Using isotopic labels, the details of the reaction mechanisms were explored.…”