The importance of multiple scattering pathways involving the absorbing atom in the interpretation and analysis of metal K-edge XAFS data of co-ordination compounds

Abstract

The presence of peaks at twice the metal–ligand distance (2R) in the Fourier transform of the Ni K-edge XAFS data of trans-[NiBr₂(PEt₃)₂], and the absence of such peaks in the data of tetrahedral-[NiBr₂(PPh₃)₂] confirm unambiguously that these 2R features are due to multiple scattering pathways involving the central metal atom in linear (or near linear) L–M–L units. Attention is drawn to the dangers of mis-interpreting these 2R features as due to solvation shells or lattice packing.