Chemical Properties of the Gas-Phase Benzvalene Radical Cation

The nature of the gas-phase benzvalene radical cation has been explored by means of comparative ion-molecule reactions studied by Fourier transform mass spectrometry and by comparative collision-induced dissociation spectra obtained by mass spectrometry/mass spectrometry. It is found that this C₆H₆ radical cation has a unique structure different from previously studied C₆H₆ radical cations, including ionized benzene. We conclude that the structure is similar to that of its neutral precursor. The rate constant of the reaction with neutral butadiene has also been measured and compared with the rate constant of the reaction of ionized fulvene and butadiene.