A comparison of shape resonant behaviour in the inner-shell photoabsorption and valence-level photoelectron spectra of SF 6, SF 5Cl and SeF 6

Abstract

Inner-shell photoabsorption and valence-level photoelectron spectra of gaseous SF 6, SF 5Cl, and SeF 6 have been obtained using synchrotron radiation spanning a 21.2–215 eV energy range. The resulting total photoabsorption cross sections of sulphur 2p (l II,III) in SF 6, sulphur and chlorine 2p (L II,III) in SF 5Cl, and selenium 3p (M II,III)) in SeF 6 are reported here. Variations in corresponding valence-level branching ratios are then compared. The well-known intense shape resonances of SF 6 are maintained in the SF 5Cl spectra, with subtle differences due to the change in symmetry and in one ligand. In contrast, the Se 3p spectrum is dramatically different, with much broader and weaker features. These observations are interpreted in terms of the potential barrier effect.