The Reaction of Vinyl Ions with Methane

Article abstract of DOI:10.1021/j150666a041

The reaction of C2H3⁺ with CH4 have been studied in an ion beam/scattering gas apparatus at collision energies in the range of 0.5-3.2 eV and at CH4 pressures in the range of 0.5-10 mtorr.Persistent collision complexes, C3H7⁺, were not observed even at the highest pressures employed, indicating that the collision-complex lifetime is less than the transit time of the apparatus (20 μs) under all conditions.However, the excellent agreement of the isotopic distributions of allyl ion, propargyl ion, vinyl ion (back-reaction), and a fraction of the methyl ion in the C2D3⁺/CH4 and C2H3⁺/CD4 systems strongly suggests that a significant part of the reaction proceeds via a long-lived C3H7^+* complex.A very significant part of the reaction that produces CH5⁺, CH3⁺, and C3H6⁺ occurs via direct processes.