Photocatalytic Hydrogen Evolution from Rhenium(I) Complexes to [FeFe] Hydrogenase Mimics in Aqueous SDS Micellar Systems: A Biomimetic Pathway

To offer an intriguing access to photocatalytic H-2 generation in an aqueous solution, the hydrophobic photosensitizer, Re(I)(4,4'-dimethylbpy)(CO)(3)Br (1) or Re(I)(1,10-phenanthroline)(CO)(3)Br (2), and [FeFe] H(2)ases mimics, [Fe-2(CO)(6)(mu-adt)CH2C6H5] (3) or [Fe-2(CO)(6)(mu-adt)C6H5] (4) [mu-adt = N(CH2S)(2)], have been successfully incorporated into an aqueous sodium dodecyl sulfate (SDS) micelle solution, in which ascorbic acid (H(2)A) was used as a sacrificial electron donor and proton source. Studies on the reaction efficiency for H-2 generation reveal that both the close contact and the driving force for electron transfer from the excited Re(I) complexes and [FeFe] H(2)ases mimics are crucial for efficient H-2 generation with visible light irradiation. Steady-state and time-resolved investigations demonstrate that the electron transfer takes place from the excited Re(I) complex 1 or 2 to [FeFe] H(2)ases mimic catalyst 3, leading to the formation of the long-lived Fe(I)Fe(0) charge-separated state that can react with a proton to generate Fe(I)Fe(II).H. an intermediate for H-2 production. As a result, a reaction vessel for the photocatalytic H-2 production in an aqueous solution is established.