INNER-SHELL EXCITATION OF PF3, PCL3, PCL2CF3, OPF3 AND SPF3 - PART I - SPECTROSCOPY

Total ion yield spectra of PF3, PCl3, PCl2CF3, OPF3 and SPF3 were reco rded in the region of P 2p, P 2s, S 2p, S 2s and halogen (Cl 2p, F 1s) excitation using synchrotron radiation. The P 2p spectra are interpre ted with GSCF3 ab initio configuration interaction calculations optimi zed for core excitation studies. The experimental-theoretical comparis on is based on both absolute intensities (oscillator strengths) and tr ansition energies. The calculations indicate that several of the discr ete states (e.g., that in PF3 at 136.5 eV) are best described as LS-co upled states because the core-valence electron exchange is very large and thus the singlet-triplet splitting is larger than the spin-orbit s plitting. While the state at 136.5 eV in PF3 is particularly notable, analogous P 2p excited states with large singlet-triplet splittings ar e calculated in PCl3, PCl2CF3, OPF3 and SPF3. Aspects of partial ion y ield measurements (particularly the PF3+ yield of PF3 and the SPF3+ yi eld of SPF,) support this interpretation by revealing isolated single states without a corresponding partner at the spin-orbit splitting. Th e partial ion yields help clarify spectral interpretation by removing interference from overlap with adjacent states having the normal (j,j) -coupled ion core character. (C) 1998 Elsevier Science B.V. All rights reserved.