Quantitative studies of the photoabsorption and photoionization of PCl3 in the valence and inner (P 2p,2s; Cl 2p,2s) shell regions

Dissociative Multiple Photoionization of GeCl4: The Ge(3d,3p,3s) and Cl(2p,2s) Inner-Shell Excitation in the Range 88∼1006 eV

“…12 Not surprisingly, Rydberg series corresponding to the Ge(3p) and Ge(3s) excitations are not observed, being consistent with a previous observation in the photoabsorption of PCl 3 , 10,16 in which the stronger transitions to the σ* than to the Rydberg orbitals occur because of the slight overlap between the Rydberg state wave function and the initial inner-shell state one. 10,15,16 The pre-edge features corresponding to the Ge(3p,3s) f σ* transitions in the Ge(3p,3s) spectra arise from the presence of the electronegative chlorine ligand, which gives rise to the backscattering of the escaping photoelectron. 15,16 This strong repulsive force acting on the escaping electron would bring about an effective potential barrier, which separates the molecular field into an inner-well region in which the virtual valence excited-state resides, as well as an outer-well region, in which Rydberg state is located.…”

“…Here the term value for the Ge(3s) corehole state is estimated as 3.5 eV, being less than the reported term value of 4.8 eV. 12 Not surprisingly, Rydberg series corresponding to the Ge(3p) and Ge(3s) excitations are not observed, being consistent with a previous observation in the photoabsorption of PCl 3 , 10,16 in which the stronger transitions to the σ* than to the Rydberg orbitals occur because of the slight overlap between the Rydberg state wave function and the initial inner-shell state one. 10,15,16 The pre-edge features corresponding to the Ge(3p,3s) f σ* transitions in the Ge(3p,3s) spectra arise from the presence of the electronegative chlorine ligand, which gives rise to the backscattering of the escaping photoelectron.…”

“…Hydrogen, , carbon(IV), phosphorus(III), and germanium(IV) chorides , together with atomic chlorine , have been the subject of photoabsorption and photoionization in the X-ray region. These studies have demonstrated that the photoionization cross sections (or yields or differential oscillator strength) in the energy range above the Cl(2p) threshold are dominated by strong lines of overlapped numerous discrete resonances due to the Cl(2p,2s) excitations, which are similar to each other in shape and strength, but showing some shift in the energy dependence of the photoionization cross section.…”

“…For a probe of competition between electronic relaxation and photochemical degradation of the core−hole state, we have chosen the GeCl 4 molecule in which the central Ge atom is surrounded by strongly electronegative chlorine atoms which can create an effective potential barrier, and consequently the large overlap between the valence state wave function and the initial inner-shell state could give rise to strongly enhanced spectral features. ,, Although the previous ab initio studies and X-ray absorption, inner-shell electron energy loss, electron transmission, and dissociative electron attachment spectroscopic studies of GeCl 4 11,12 by Guillot et al are quite informative as to the photoabsorption positions and spectral features of the various core−hole states, additional information on the relative importance of individual ions in the photoionization is necessary to derive individual photoionization cross sections. Furthermore, study of dissociation processes associated with various discrete core excitation channels could become a viable approach to the understanding of the core ionization structure.…”