Molybdenum L_II,III Edge Studies

Abstract

X-ray absorption edge structure has proven quite useful in the study of first-row transition metals; Some of these applications are discussed elsewhere in this book. There have been fewer studies of edge structure for second-row transition metals, due in part to the fact that the K absorption edges for these metals occur at higher energy (>17keV). At higher energy, the monochromator energy bandpass and the intrinsic (core hole lifetime) broadening of the edge features both increase. These effects combine to give an effective resolution of, for example, 10 eV or worse at the Mo K edge. Low resolution thus hinders detailed studies of the edge structure of many important metalloproteins. These resolution degrading effects are less severe at lower energies, thus suggesting that edge structure which is unresolvable at the Mo K edge may be resolved at the L edges. An additional advantage of L edge spectroscopy is the ability to study both s and p symmetry initial states, thereby enhancing the electronic information which can be obtained.