Reactions of Gaseous, Halogenated Propene Radical Cations with Ammonia: A Study of the Mechanism by Fourier Transform Ion Cyclotron Resonance

Abstract

Gas-phase ion-molecule reactions of radical cations with ammonia have been investigated. The addition of an ammonia molecule to the ionized double bond of 2-halogenopropenes is so fast that it competes successfully with the very exothermic proton transfer from the methyl group (below). In fact, deprotonation of the unsaturated radical cation may occur by an addition-elimination mechanism via the excited β-distonic radical cation. In the gas phase the further decomposition of this intermediate by loss of the halogen depends on the energy released during the addition step.