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

• Published in: Chemistry & biodiversity 2008-10, Vol.5 (10), p.2023-2041
• Main Authors: Windhager, Jochen, Seidel, Raphael A., Apfel, Ulf-Peter, Görls, Helmar, Linti, Gerald, Weigand, Wolfgang
• Format: Article
• Language: English
• Subjects: [FeFe]-Hydrogenase; Binding Sites; Cluster compounds; Crystallography, X-Ray; Density-functional theory (DFT); Hydrogenase - chemistry; Iron complexes; Iron Compounds - chemical synthesis; Iron Compounds - chemistry; Magnetic Resonance Spectroscopy; Models, Chemical; Models, Molecular; Molecular Structure; Oxidation; Oxidation-Reduction; Sulfur Compounds - chemical synthesis; Sulfur Compounds - chemistry; Sulfur dithiolato complexes; X-Ray crystallography
• ISSN: 1612-1872; 1612-1880
• DOI: 10.1002/cbdv.200890185

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 (CH2)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 (CH2)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.