Oxidation of Diiron and Triiron Sulfurdithiolato Complexes: Mimics for the Active Site of [FeFe]‐Hydrogenase

The oxidation of the hexacarbonyl(1,3‐dithiolato‐ S , S ′)diiron complexes 4a – 4c with varying amounts of dimethyldioxirane (DMD) was systematically studied. The chemoselectivity of the oxidation products depended upon the substituent R (R=H, Me, 1/2 (CH 2 ) 5 ). For R=H, four oxidation products, 6a – 6d , have been obtained. In the case of R=Me, three products, 7a – 7c , were formed, and for R=1/2 (CH 2 ) 5 , only complex 8 was observed. These observations are due to steric and electronic effects caused by the substituent R. Additionally, oxidation of the triiron complex 5 with DMD was performed to yield the products 9a and 9b . X‐Ray diffraction analyses were performed for 6a – 6d, 7a , and 7c , as well as for 9a and 9b . The electronic properties were determined by density‐functional theory (DFT) calculations.