Direct optical spectroscopy of gas-phase molecular ions trapped and mass-selected by ion cyclotron resonance: laser-induced fluorescence excitation spectrum of hexafluorobenzene (C6F6+)

The laser-induced fluorescence (LIF) excitation spectrum of gas-phase hexaf luorobenzene cations (C6F6+) has been measured at room temperature, by ion trapping and cyclotron frequency-based mass-selection. The optical spectral resolution, vibrational state assignments, and their corresponding wavelen gths compare favorably to prior data [J. Chem. Phys. 70 (1979) 138]. The pr esent approach offers a general entry into optical spectroscopy of collisio nally stable gas-phase ions. (C) 2001 Elsevier Science B.V. All rights rese rved.