Double ionization of fluorobenzene to singlet and triplet states of its dication

Double-ionization energies of the fluorobenzene molecule to singlet and triplet electronic states of its dication have been measured using double-charge-transfer spectroscopy. The values obtained are compared with those calculated using a semi-empirical form of the multiple-scattering Xα computational method. The calculated data show that the density of electronic states of C6H5F2+ increases markedly as the energy increases. However, the first six measured energies to triplet states, and the first five to singlet states, closely match the energies of predicted electronic transitions, thereby verifying the association of these measured energies with double ionization to specific states of C6H5F2+.