Gauging Iron-Sulfur Cubane Reactivity from Covalency: Trends with Oxidation State.

ABSTRACT: We investigated room-temperature metal and ligand K-edge X-ray absorption (XAS) spectra of a complete redox series of cubane-type iron-sulfur clusters. The Fe K-edge position provides a qualitative but convenient alternative to the traditional spectroscopic descriptors used to identify oxidation states in these systems, which we demonstrate by providing a calibration curve based on two analytic methods. Furthermore, high energy resolution fluorescence detected XAS (HERFD-XAS) at the S K-edge was used to measure Fe-S bond covalencies and record their variation with the average valence of the Fe atoms. While the Fe-S(thiolate) covalency evolves linearly, gaining 11 ± 0.4% per bond and hole, the Fe-S(μ³) covalency evolves asystematically, reflecting changes in the magnetic exchange

SUBMITTER: Grunwald L 

PROVIDER: S-EPMC11040707 | biostudies-literature | 2024 Apr

REPOSITORIES: biostudies-literature