Electronic spectroscopy of bromopentafluorobenzene by high-resolution vacuum ultraviolet photoabsorption, electron impact, and photoelectron spectroscopies

The electronic transitions of bromopentafluorobenzene (C6F5Br) have been investigated by high-resolution photoabsorption spectroscopy in the energy range 4–10.8 eV. In addition, the electron energy loss spectrum (EELS) was recorded in non-strictly electric dipolar interaction conditions (40 eV incident energy, 10° scattering angle) over the range 4–13.0 eV. The present spectra provide the first experimental data on the electronic states of bromopentafluorobenzene. The characteristics of the electronic excited states are discussed and the terrestrial atmospheric photolysis rates have been derived from the absolute photoabsorption cross-sections. The ionisation energies of the occupied molecular orbitals have been measured by high-resolution He(I) photoelectron spectroscopy, allowing a precise value of 9.679 ± 0.002 eV to be derived for the ionic ground state.