Ion–molecule reactions in gaseous hydrogen + pentane mixtures

Abstract

The reactions of H⁺₃ and D⁺₃ with n-C₅D₁₂ and n-C₅H₁₂, respectively, have been studied. The protonating species have been generated from hydrogen by ⁶⁰Co γ-rays at 10 Torr or by electron impact in an ion-cyclotron-resonance apparatus at 10^–4 Torr. Using both techniques the relative probability of fragmentation reactions of the pentonium ion was measured and the reaction mechanism is discussed. The transferred proton is shown to be retained to a different extent in the fragment alkyl ions. The pentyl ion isomerizes to the tertiary structure and yields mainly 2-methylbut-2-ene, 2-methylbut-1-ene, and isobutene after being neutralized.