Self-catalysis in the gas-phase: enolization of the acetone radical cation

Because of a prohibitively large barrier, the solitary acetone radical cation, CH3C(O)CH3+ (1+) does not rearrange, neither spontaneously nor by activation, to its more stable enol isomer, CH2C(OH)CH3+ (1a+). However, this isomerization occurs smoothly by an ion–molecule interaction with neutral acetone itself. The dimer radical cation, [1+⋯1], generated under conditions of chemical ionization dissociates to m/z 58 and collision-induced …