Double ionization of hexafluorobenzene: energies required to populate singlet and triplet electronic states of C 6F 62+

Abstract

The double-ionization energies of hexafluorobenzene to singlet and triplet electronic states of its dication have been measured by double-charge-transfer spectroscopy. Because the energy-loss spectrometer used has a high resolving power, more information about the electronic-state manifolds of C 6F 6 2+ was obtained than existed from the results of previous studies. The values of double-ionization energies determined are compared with those calculated in a previous investigation using the Green's function method. Because the predicted density of singlet and triplet states is high, only the lower energies can be identified with specific electronic transitions. For the higher energies, many states could be populated to generate each of the spectral peaks observed.