Substituent effect on ion–molecule reaction of disubstituted benzenes with acetone plasma

Abstract

We investigated the ion–molecule reactions of disubstituted benzenes with acetone or acetone-d 6 as reagent gases under chemical ionization conditions, and the fragmentation reactions of the adduct ions (mostly acetyl ion and protonated acetone adducts) using collision-induced dissociation (CID) technique. The CID results of [M+A dD] + ions of phenylamine derivatives suggest that the phenylamine derivatives have higher proton affinities than acetone. Our experiments also suggest: (1) electron-releasing substituents favor the adduct reactions, while electron-withdrawing groups do not; (2) the position and properties of substituting groups have an effect on the relative abundances of the adduct ions; (3) the fragmentation reaction of the acetyl adduct ion formed by the reaction of ortho-phenylenediamine with acetyl ion is similar to the reductive alkylation reaction in the liquid phase.