L-edge x-ray-absorption spectra ofPdAl3andPdCl2: A study of charge redistribution in compounds of an element with a nearly full 4dshell

Abstract

Using the x-ray-absorption near-edge structure technique discussed in the preceding paper, we have studied the Pd L-edge absorption spectra of ${\mathrm{PdAl}}_3$ and ${\mathrm{PdCl}}_2$. It is found that the Pd 4d population at the Pd site in these compounds is depleted relative to pure Pd metal upon compound formation in both cases. The results are discussed in terms of a d and non-d charge-compensation model for the metallic compound and a molecular-orbital approach for the molecular complex. It is also found that when compared with Pd metal the intensity ratio of the $L_{\mathrm{III}}$- and the $L_{\mathrm{II}}$-edge ‘‘white line’’ in these compounds is much closer to the statistical ratio. The implications of these observations are discussed.