Metal L-edges

Metal L-edge XAS mostly focuses on transitions from the 2p6 core. The 2p —> 3d and 2p —> 4s are electric dipole allowed with the p - - d channel being 20-fold more intense.52 Therefore, L-edges are a more direct method to study d valence levels relative to the metal K-edges. Also, the spectra are taken at much lower photon... 

Fig. 1 Energy level diagram comparing d — d transitions, metal L-edge and metal K-edge excitations for first transition series elements...

Chamock JM, Henderson CMB, Mosselmans JFW, Pattrick RAD (1996) 3d transitional metal L-edge X-ray absorption studies of the dichalcogenides of Fe, Co and Ni. Phys Chem Minerals 23 403-408 Charlet L, Manceau A (1992a) In situ characterization of heavy metal surface reactions the chromium case. Int J Environ Anal Chem 46 97-108... 

Metal L edge 3- to 4-fold higher resolution than metal K edge allowed 2p-3d transitions are observed metal L edge contains information on spin state, oxidation state, and LF splitting of d orbitals intensity probes metal-ligand covalency L edge MCD possesses similar information content to MCD described above... 

Time-Dependent Density Functional Theory Calculations of Ligand K Edge and Metal L Edge X-ray Absorption of a Series of Oxomolybdenum Complexes. 

Roemelt M, Maganas D, DeBeer S, Neese F. A combined DFT and restricted open-shell configuration interaction method including spin-orbit coupling Application to transition metal L-edge X-ray absorption spectroscopy. J Chem Phys. 2013 138 204101. 

Figure 2 Surface EXAFS spectra above the Pd L edge for a 1.5 monolayer evaporated film of Pd on Sid 11) and for bulk palladium ailicide, Pd2Si and metallic Pd.

The Fine Structure Before and After Each Edge. ELNES is the term use to describe the energy-loss near edge structure, and this can be quite different for an element in different compounds. For example the shape of the aluminium L edges are quite different in EELS spectra from metallic aluminium and aluminium oxide, so that the chemical form of a given element may be indentified from these small variations in intensity after the edge. 

Figure 7. Ground-state wave function of plastocyanin. A HOMO wave function contour for plastocyanin (28). B HOMO wave function contour for the thiolate copper complex tet b (34/ C Copper L-edge (38) and sulfur K-edge (34) spectra as probes of metal-ligand covalency. D Absorption, single-crystal polarized absorption, and low-temperature MCD spectra of plastocyanin. The absorption spectrum has been Gaussian resolved into its component bands as in reference 33.

X-ray MCD spectroscopy based on L-edge absorption experiments can be used to analyze localized spin states at specific metal sites. 

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