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The state-selective dissociation dynamics for anionic and excited neutral fragments of gaseous SiCl 4 following Cl 2p and Si 2p core-level excitations were characterized by combining measurements of the photoninduced anionic dissociation, x-ray absorption and UV/visible dispersed fluorescence. The transitions of core electrons to high Rydberg states/doubly excited states in the vicinity of both Si 2p and Cl 2p ionization thresholds of gaseous SiCl 4 lead to a remarkably enhanced production of anionic, Si − and Cl − , fragments and excited neutral atomic, Si * , fragments. This enhancement via core-level excitation near the ionization threshold of gaseous SiCl 4 is explained in terms of the contributions from the Auger decay of doubly excited states, shake-modified resonant Auger decay, or/and post-collision interaction. These complementary results provide insight into the state-selective anionic and excited neutral fragmentation of gaseous molecules via core-level excitation.

Edge shifts, Δ E, and effective nuclear charges, Z eff, for several polymeric copper(II) complexes of salicylhydroxamic acids have been estimated from copper K-absorption discontinuity using a 40 cm curved crystal spectrograph. The shifts show a parabolic dependence on the effective atomic charge, Z eff, of copper, indicating that an expression of the type Δ E=a Z eff+b(Z eff)2, where Z eff is the effective atomic charge on the atom in a binary compound, is equally applicable to the complex systems. Finally, the XANES is analyzed critically in terms of edge shifts as well as of effective nuclear charge. Increase of the edge shift due to metal-metal interaction is not observed in the present case.

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X-ray absorption edge shifts for a number of cobalt complexes are reported and an empirical correlation between the shift and the effective nuclear charge (Z eff) of the cobalt atom and the sum of the ligand electronegativity differences from that of cobalt are proposed following regression analysis of the data.