One- to two-electron reduction of an [FeFe]-hydrogenase active site mimic: the critical role of fluxionality of the [2Fe2S] core.
The one- to two-electron reduction of mu-(1,2-ethanedithiolato)diironhexacarbonyl that has been observed under electrochemical conditions is dependent on scan rate and temperature, suggesting activation of a structural rearrangement. This structural rearrangement is attributed to fluxionality of the [2Fe2S] core in the initially formed anion. Computations support this assessment. Upon an initial one-electron reduction, the inherent fluxionality of the [2Fe2S] complex anion allows for a second one-electron reduction at a less negative potential to form a dianionic species. The structure of this dianion is characterized by a rotated iron center, a bridging carbonyl ligand, and, most significantly, a dissociated Fe-S bond. This fluxionality of the [2Fe2S] core upon reduction has direct implications for the chemistry of [FeFe]-hydrogenase mimics and for iron-sulfur cluster chemistry in general.
Felton
Greg A N
GA
Department of Chemistry and Biochemistry, The University of Arizona, Tucson, Arizona 85721, USA.
Petro
Benjamin J
BJ
Glass
Richard S
RS
Lichtenberger
Dennis L
DL
Evans
Dennis H
DH
D032701:Biomimetics; D002384:Catalysis; D020134:Catalytic Domain; D055664:Electrochemical Techniques; D004583:Electrons; D005296:Ferrous Compounds / Q000737:chemistry*; D006864:Hydrogenase / Q000737:chemistry*; D007506:Iron-Sulfur Proteins / Q000737:chemistry*; D008958:Models, Molecular; D010084:Oxidation-Reduction
D005296:Ferrous Compounds; D007506:Iron-Sulfur Proteins; C545491:mu-(1,2-ethanedithiolato)diironhexacarbonyl; D006864:Hydrogenase