Hydroxylation of selected hydrocarbon ions on reaction with methanol in the gas phase

The ion‐molecule reactions of selected hydrocarbon cations with methanol which lead to the production of hydroxylated odd‐electron molecular ions in the high‐pressure ion source of a mass spectrometer or in the central quadrupole of a tandem quadrupole mass spectrometer are described. A wide variety of hydrocarbon cations were investigated, including aliphatic and aromatic cations; of these, only those having a vacant site on an aromatic system appear to undergo the hydroxylation reaction in high yield. A mechanism is proposed for the formation of the molecular ion of phenol from the ion‐molecule reaction involving the phenyl cation with methanol. In addition, thermochemical data are provided which support the formation of the postulated species.