An experimental and theoretical study of ionized hydroxyacetone: a stable, hydrogen-bridged radical cation

Abstract

Ion-molecule reactions and collision-activated dissociation experiments were used to examine the structure of the long-lived, low-energy molecular ion of hydroxyacetone [CH 3 C(O)CH 2 OH] .+ (1) in a dual-cell Fourier-transform ion cyclotron resonance mass spectrometer (FT-ICR). It is demonstrated that a significant proportion of the nonfragmenting ions have a noncovalent, hydrogen-bridged structure, most likely [CH 3 C=O...H...O=CH 2 ] .+ (2). This hydrogen-bridged ion undergoes reactions which are unique for a radical cation and which can best be described as solvent switching reactions: neutral reagents replace the acetyl radical in the ion