Haiqing Hu, P. Wenthold
Jul 1, 2001
Citations
0
Influential Citations
3
Citations
Journal
Journal of the American Society for Mass Spectrometry
Abstract
The structure of ionized 1,5-hexadiene, prepared by charge transfer between 1,5-hexadiene and CS2+., is examined using energy-resolved collision-induced dissociation (CID). By comparing the product distributions and product appearance curves with those of authentic low-energy C6H10+. ions, it is determined that 1,5-hexadiene cation spontaneously rearranges to cyclohexene cation in the gas-phase. The proposed mechanism for formation of cyclohexene cation in the gas phase is analogous to that determined for this process under matrix isolation conditions, where it proceeds via a Cope rearrangement to the cyclohexane-1,4-diyl cation, followed by isomerization to cyclohexene cation. It is shown that electron ionization (EI) of 1,5-hexadiene gives a different molecular ion than is obtained upon chemical ionization (CI). The energy-resolved CID mass spectrum for the EI product is consistent with what would be obtained for a mixture of low energy ion isomers.