| Autor: |
Coutinho LH; Physics Institute, Federal University of Rio de Janeiro, Rio de Janeiro, 21941-972, Brazil. lucia@if.ufrj.br., de A Ribeiro F; Federal Institute of Rio de Janeiro, Rio de Janeiro, 26530-060, Brazil., Tenorio BNC; Department of Chemistry, Technical University of Denmark, Kongens Lyngby, 2800, Denmark., Coriani S; Department of Chemistry, Technical University of Denmark, Kongens Lyngby, 2800, Denmark., Dos Santos ACF; Physics Institute, Federal University of Rio de Janeiro, Rio de Janeiro, 21941-972, Brazil. lucia@if.ufrj.br., Nicolas C; Synchrotron SOLEIL, Gif-sur-Yvette, 91192, France., Milosavljevic AR; Synchrotron SOLEIL, Gif-sur-Yvette, 91192, France., Bozek JD; Synchrotron SOLEIL, Gif-sur-Yvette, 91192, France., Wolff W; Physics Institute, Federal University of Rio de Janeiro, Rio de Janeiro, 21941-972, Brazil. lucia@if.ufrj.br. |
| Abstrakt: |
We report on single- and double-charge photofragment formation by synchrotron radiation, following C 1s core excitation and ionization and Cl 2p inner excitation and ionization of chlorobenzene, C 6 H 5 Cl. From a comparison of experimental near-edge X-ray absorption fine structure spectra and theoretical ab initio calculations, the nature of various core and inner shell transitions of the molecule and pure atomic features were identified. To shed light on the normal Auger processes following excitation or ionization of the molecule at the Cl 2p or C 1s sites, we addressed the induced ionic species formation. With energy resolved electron spectra and ion time-of-flight spectra coincidence measurements, the ionic species were correlated with binding energy regions and initial states of vacancies. We explored the formation of the molecular dication C 6 H 5 Cl 2+ , the analogue benzene dication C 6 H 4 2+ , and the singly charged species produced by single loss of a carbon atom, C 5 H n Cl + . The appearance and intensities of the spectral features associated with these ionic species are shown to be strongly site selective and dependent on the energy ranges of the Auger electron emission. Unexpected intensities for the analogue double charged benzene C 6 H 4 2+ ion were observed with fast Auger electrons. The transitions leading to C 6 H 5 Cl 2+ were identified from the binding energy representation of high resolution electron energy spectra. Most C 6 H 5 Cl 2+ ions decay into two singly charged moieties, but intermediate channels are opened leading to other heavy dicationic species, C 6 H 4 2+ and C 6 H 4 Cl 2+ , the channel leading to the first of these being much more favored than the other. |
