Department of Inorganic Spectroscopy, Max Planck Institute for Chemical Energy Conversion, Stiftstrasse 34-36, 45470, Mülheim an der Ruhr, Germany.
European XFEL, Holzkoppel 4, 22869, Schenefeld, Germany.
Angew Chem Int Ed Engl. 2021 Apr 26;60(18):10112-10121. doi: 10.1002/anie.202015669. Epub 2021 Mar 23.
The ability of resonant X-ray emission spectroscopy (XES) to recover physical oxidation state information, which may often be ambiguous in conventional X-ray spectroscopy, is demonstrated. By combining Kβ XES with resonant excitation in the XAS pre-edge region, resonant Kβ XES (or 1s3p RXES) data are obtained, which probe the 3d final-state configuration. Comparison of the non-resonant and resonant XES for a series of high-spin ferrous and ferric complexes shows that oxidation state assignments that were previously unclear are now easily made. The present study spans iron tetrachlorides, iron sulfur clusters, and the MoFe protein of nitrogenase. While 1s3p RXES studies have previously been reported, to our knowledge, 1s3p RXES has not been previously utilized to resolve questions of metal valency in highly covalent systems. As such, the approach presented herein provides chemists with means to more rigorously and quantitatively address challenging electronic-structure questions.
共振 X 射线发射光谱（XES）能够恢复物理氧化态信息，这在常规 X 射线光谱中往往是不明确的，这一点得到了证明。通过将 Kβ XES 与 XAS 预边区域的共振激发相结合，获得了共振 Kβ XES（或 1s3p RXES）数据，该数据探测 3d 末态构型。对一系列高自旋亚铁和铁配合物的非共振和共振 XES 的比较表明，以前不清楚的氧化态赋值现在可以很容易地确定。本研究涵盖了四氯化铁、铁硫簇和固氮酶的 MoFe 蛋白。虽然以前已经报道了 1s3p RXES 研究，但据我们所知，1s3p RXES 以前并未用于解决高度共价体系中金属价态的问题。因此，本文提出的方法为化学家提供了更严格和定量地解决具有挑战性的电子结构问题的手段。
