Gaseous Arenium Ions at Atmospheric Pressure: Elementary Reactions and Internal Solvation Effects

The title species, of paramount importance as key intermediates of electrophilic aromatic substitution reactions, are amenable to mechanistic studies by mass spectrometric and radiolytic techniques. They have proven to be versatile benchmark models for the study of elementary processes such as proton migration, which may occur in both intra- and intermolecular fashions. This Account primarily focuses on proton migration reactions involving arenium ions. Additionally, the effect of a second unsaturated ring bound by an aliphatic chain of variable length on the stability and reactivity of the arenium ion is examined and quantitatively evaluated.