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DOE OSTI · 2471696

Sulfur-Ligated [2Fe-2C] Clusters as Synthetic Model Systems for Nitrogenase

Yogendra, Sivathmeehan·Wilson, Daniel N.·Hahn, Anselm W.·Weyhermüller, Thomas·Van Stappen, Casey·Holland, Patrick·DeBeer, Serena
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Abstract

Metal clusters featuring carbon and sulfur donors have coordination environments comparable to the active site of nitrogenase enzymes. Here, we report a series of di-iron clusters supported by the dianionic yldiide ligands, in which the Fe sites are bridged by two μ 2 -C atoms and four pendant S donors. The [L 2 Fe 2 ] (L = {[Ph 2 P(S)] 2 C} 2– ) cluster is isolable in two oxidation levels, all-ferrous Fe 2 II and mixed-valence Fe II Fe III . The mixed-valence cluster displays two peaks in the Mössbauer spectra, indicating slow electron transfer between the two sites. The addition of the Lewis base 4-dimethylaminopyridine to the Fe2 II cluster results in coordination with only one of the two Fe sites, even in the presence of an excess base. Conversely, the cluster reacts with 8 equiv of isocyanide t BuNC to give a monometallic complex featuring a new C–C bond between the ligand backbone and the isocyanide. The electronic structure descriptions of these complexes are further supported by X-ray absorption and resonant X-ray emission spectroscopies.

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37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRYCluster chemistryInorganic carbon compoundsLigandsMolecular structurePeptides and proteins

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Yogendra, Sivathmeehan, Wilson, Daniel N., Hahn, Anselm W., Weyhermüller, Thomas, Van Stappen, Casey, Holland, Patrick, DeBeer, Serena. 2023-01-30. Sulfur-Ligated [2Fe-2C] Clusters as Synthetic Model Systems for Nitrogenase. https://doi.org/10.1021/acs.inorgchem.2c03693

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