Reactions of the negative oxygen ion (O−·) with carbonyl compounds

Abstract

Reactions of O^−· ions with some aliphatic carbonyl compounds have been studied using ion cyclotron resonance spectrometry. With ketones, major products are OH^–, (M—H)^–, (M—H₂)^−· and (M—R)^– ions; at higher pressures, OH^– ions react further to yield (M—H)^– ions. Limiting low and high pressure behaviour is used to derive relative rate constants for these reactions. Deuterium-labelling experiments suggest that the (M—H₂)^−· ion is formed by abstraction of a hydrogen atom and a proton exclusively from positions α to the carbonyl function. A brief study was also made of reactions with acetaldehyde and methyl acetate.