Jahn-Teller coupling and fragmentation after core-shell excitation in CF4 investigated by partial-ion-yield spectroscopy

We investigate fragmentation processes induced by core-level photoexcitation in CF4 at both the carbon and fluorine K edges by means of partial-ion-yield spectroscopy. The molecule CF4 is a textbook example of systems in which Jahn-Teller coupling strongly manifests itself in the photoabsorption spectrum. Spectral features related to Jahn-Teller and quasi-Jahn-Teller splitting are observed, and important differences in the fragmentation pathways are revealed depending on the symmetries of the core-excited states. We interpret these experimental observations on the grounds of symmetry lowering from the T-d to the C-3v point group as well as preferential orientation with respect to the polarization vector of the incident radiation.