Electrochemical Behavior of Mono‐Substituted [FeFe]‐Hydrogenase H‐Cluster Mimic Mediated by Stannylated Dithiolato Ligand

Abstract

In this research work we present the synthesis and characterization of asymmetrical [FeFe]‐hydrogenase mimic, [Fe2(CO)5P(OMe)3{μ‐(SCH2)2SnPh2}] (2), obtained from replacing one of the CO ligands of the parent hexacarbonyl complex [Fe2(CO)6{μ‐(SCH2)2SnPh2}] (1) with the monodentate phosphite P(OMe)3. The molecular structure of complex 2 was confirmed by X‐ray diffraction analysis. Moreover, the electrochemistry of complexes 1 and 2 was investigated to explore the influence of the steric bulk of the Ph‐ring at the bridgehead Sn atom with the nearby P(OMe)3 ligand. In addition, both complexes show their potentials toward hydrogen formation in the presence of weak acid, such as acetic acid (AcOH), suggesting an ECEC (E=electron transfer, C=chemical process) mechanism for hydrogen production.

Phosphite Bearing [(μ-ADT)RFe2(CO)6] (ADT = Azadithiolate) Moieties: A Tool for the Building of Multimetallic [FeFe]-Hydrogenase Mimics

“…In this context, we devised the incorporation of phosphite groups in the [FeFe] structure as a strategy to add an anchoring point to the [FeFe] mimic suitable to coordinate to diverse metal centers and surfaces. Phosphite groups have been widely employed as ligands of the Fe centers of [FeFe]-hydrogenase mimics − to modify the electronic properties of the metal or to study the mechanism of the HER . Nevertheless, to the best of our knowledge, the use of a phosphite group to coordinate [FeFe]-hydrogenase mimics to metal centers has not been described.…”