Multiedge X-ray Absorption Spectroscopy Part II: XANES Analysis of Bridging and Terminal Chlorides in Hexachlorodipalladate(II) Complex

Abstract

X-ray absorption spectroscopy is a unique experimental technique that can provide ground state electronic structure information about transition metal complexes with unoccupied d-manifold. The quantitative treatments of pre-edge and rising-edge features have already been developed for the sulfur- and chlorine-ligand K-edge excitations. The complementarity of using multiple core excitation edges from hard, tender, and soft X-ray energy regions has been defined for the first paper of this series. The given study provides compelling evidence for the transferability of the empirical transition dipole integral from ligand K-edge to metal L-edge and back to ligand K-edge in the tender X-ray energy range. The case study was performed for a series of homoleptic chloropalladium compounds at the chlorine K- and palladium L-edges. We propose the method described here to be generally applicable for other core level excitations, where complementarity of ground state electronic structural information from XANES analysis can provide the complete electronic structure description.

Distorted tetrahedral nickel-nitrosyl complexes: spectroscopic characterization and electronic structure

“…The fitting of spectral features and uncertainty analysis were carried out as defined before [44]. The conversion of spectral intensities to orbital compositions was described in detail for complementary ligand K-and metal L-edge multi-edge treatments [45].…”

“…For the studied complexes, we took advantage of the entire energy range of synchrotron radiation that includes hard, tender, and soft X-ray regions for the Ni K-, Cl and P K-, and Ni L-edges, respectively. While individual edges may not give unambiguous information about the metal center's effective/formal oxidation state, ligand field splitting, and ionic/covalent metal-ligand interactions, the combined use of metal K-, ligand K-, and metal L-edges can experimentally define the complete electronic structure of a coordination complex [44,45].…”

Mono- and binuclear tris(3-tert-butyl-2-sulfanylidene-1H-imidazol-1-yl)hydroborate bismuth(III) dichloride complexes: a soft scorpionate ligand can coordinate top-block elements

“…The rising-edge features superimposed on the ionization edge-jump for the Tm tBu ligand are informative about changes in the S-C bonding (Queen et al, 2013). The appearance of multiple preedge features at the Cl K-edge is indicative of the different chemical environments of the terminal and bridging chloride ligands (Barton et al, 2015). Fig.…”

“…The individual fits with the least number of Gaussian/Lorentzian amplitude functions were determined from the number of resolved peaks from the second derivative spectra (see Supporting information). The conversion of spectral intensities to orbital compositions was carried out as described earlier for terminal and bridging chloride (Barton et al, 2015) and sulfur ligands (Queen et al, 2013).…”

“…Relativistic effects were considered by requesting molecular integral evaluations employing the Douglas-Kroll-Hess 4th order relativistic correction including spin-orbit terms. The connection between the experimental and calculated Bi-S/Cl bond covalency was derived using the transition dipole expression (Solomon et al, 2005), as detailed in Barton et al (2015) and Queen et al (2013). The H-atom positions for the sodium salt of the Tm tBu anion and complexes (I) and (II) were refined by structural optimizations.…”