Spin-Polarization-Induced Preedge Transitions in the Sulfur K-Edge XAS Spectra of Open-Shell Transition-Metal Sulfates: Spectroscopic Validation of σ-Bond Electron Transfer.

ABSTRACT: Sulfur K-edge X-ray absorption spectroscopy (XAS) spectra of the monodentate sulfate complexes [M^II(itao)(SO₄)(H₂O)_0,1] (M = Co, Ni, Cu) and [Cu(Me₆tren)(SO₄)] exhibit well-defined preedge transitions at 2479.4, 2479.9, 2478.4, and 2477.7 eV, respectively, despite having no direct metal-sulfur bond, while the XAS preedge of [Zn(itao)(SO₄)] is featureless. The sulfur K-edge XAS of [Cu(itao)(SO₄)] but not of [Cu(Me₆tren)(SO₄)] uniquely exhibits a weak transition at 2472.1 eV, an extraordinary 8.7 eV below the first inflection of the rising K-edge. Preedge transitions also appear in the sulfur K-edge XAS of crystalline [M^II(SO₄)(H₂O)] (M = Fe, Co, Ni,

SUBMITTER: Frank P 

PROVIDER: S-EPMC5733802 | biostudies-literature | 2017 Feb

REPOSITORIES: biostudies-literature