Effective nuclear charge and chemical shifts in X-ray absorption spectra of polymeric copper (II) salicylhydroxamates

Edge shifts, ΔE, and effective nuclear charges, Zeff 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, Zeff, of copper, indicating that an expression of the type ΔE=aZeff+b(Zeff)2, where Zeff 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. (author)