Architectural Mimics of FeFe-Hydrogenase H-Cluster : Synthesis, Characterization and Electrochemical studies

The utilization of H2 for energy was probably a crucial feature of very early life on this planet. Therefore, the tendency to find a proper way to produce H2 is an interest area for research in the scientific community. In Fact, the nature has high ability to catalyze the reversible reduction of protons to molecular hydrogen through metalloenzymes known as hydrogenases. These metalloenzymes can be classified into [Fe]-hydrogenases (Hmd), [NiFe]-hydrogenases and [FeFe]-hydrogenases. In the case of the latter, the reaction takes place at the “H-cluster”, which consists of an [4Fe4S] cubane attached through a cysteinyl residue to a butterfly [2Fe2S] sub-cluster. The [2Fe2S] unit features a bridging azadithiolato ligand as well as biologically unusual CO and CN- ligands. Over the past decades, numerous synthetic models which mimic the H-cluster have been reported to provide a better understanding of the structure and function of the active site of the enzyme-mimic models. Moreover, these models have been extended to diiron complexes containing diselenato and ditellurato ligands.