A Silicon-Heteroaromatic System as Photosensitizer for Light-Driven Hydrogen Production by Hydrogenase Mimics


  • Dedicated to Professor Wolfgang Beck


The utilization of light and inexpensive catalysts to afford hydrogen represents a huge challenge. Following our interest in silicon-containing [FeFe]-hydrogenase ([FeFe]-H2ase) mimics, we report a new model approach for a photocatalytic [FeFe]-H2ase mimic 1, which contains a 1-silafluorene unit as a photosensitizer. Thereby, the photoactive ligand is linked to the [2Fe2S] cluster through S–CH2–Si bridges. Photochemical H2 evolution experiments were performed and revealed a turnover number (TON) of 29. This is the highest reported photocatalytic efficiency for an [FeFe]-H2ase model complex in which the photosensitizer is covalently linked to the catalytic center.