Iodopentafluorobenzene: Electronic state spectroscopy by high-resolution vacuum ultraviolet photoabsorption and photoelectron spectroscopy

The electronic transitions of iodopentafluorobenzene (C6F5I) have been investigated experimentally for the first time by high-resolution photoabsorption spectroscopy in the energy range 3.6-10.7 eV. The character of the valence excited states has been discussed taking into account calculations available in the literature. The ionisation energies of the molecule in its electronic ground state have been measured by high-resolution He(I) photoelectron spectroscopy. The energies of the ionic bands are shifted by about 0.5 eV compared to the earliest literature values but they agree with the most recently published measurements. All the spectra presented in this paper represent highest resolution measurements of their kind for iodopentafluorobenzene. The absolute photoabsorption cross-sections have been used to model photolysis rates and residence times in the terrestrial atmosphere.