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- Gao, Weiming, et al.
(författare)
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An azadithiolate bridged Fe2S2 complex as active site model of FeFe-hydrogenase covalently linked to a Re(CO)(3)(bpy)(py) photosensitizer aiming for light-driven hydrogen production
- 2008
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Ingår i: Comptes rendus. Chimie. - : Elsevier BV. - 1631-0748 .- 1878-1543. ; 11:8, s. 915-921
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Tidskriftsartikel (refereegranskat)abstract
- In order to create photoactive catalysts for hydrogen production, a novel trimetallic Re-Fe2S2 complex 4 was synthesized by the coordination of the free -PPh2 group of the ligand of the rhenium photosensitizer 6 to an azadithiolate (ADT)-bridged diiron complex 8 with the assistance of the decarbonylation reagent Me3NO. Complex 4 was characterized by H-1, C-13, P-31 NMR and HRMS spectra. The IR, UV-vis and electrochemical data indicate some interactions between Re and Fe2S2 moieties, and the photo-induced electron transfer from the excited state of the Re moiety to the Fe2S2 catalyst is thermodynamically feasible.
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| 2. |
- Gao, Weiming, et al.
(författare)
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Binuclear iron-sulfur complexes with bidentate phosphine ligands as active site models of Fe-hydrogenase and their catalytic proton reduction
- 2007
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Ingår i: Inorganic Chemistry. - : American Chemical Society (ACS). - 0020-1669 .- 1520-510X. ; 46:6, s. 1981-1991
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Tidskriftsartikel (refereegranskat)abstract
- The displacement of CO in a few simple Fe(I)-Fe(I) hydrogenase model complexes by bisphosphine ligands Ph2P-(CH2)(n)-PPh2 [with n = 1 (dppm) or n = 2 (dppe)] is described. The reaction of [{mu-(SCH2)(2)CH2}Fe-2(CO)(6)] (1) and [{mu-(SCH2)(2)N(CH2CH2CH3)}Fe-2(CO)(6)] (2) with dppe gave double butterfly complexes [{mu-(SCH2)(2)CH2}Fe-2(CO)(5)(Ph2PCH2)](2) (3) and [{mu-(SCH2)(2)N(CH2CH2CH3)}Fe-2(CO)(5)(Ph2PCH2)](2) (4), where two Fe2S2 units are linked by the bisphosphine. In addition, an unexpected byproduct, [{mu-(SCH2)(2)N(CH2CH2CH3)}Fe-2(CO)(5){Ph2PCH2CH2(Ph2PS)}] (5), was isolated when 2 was used as a substrate, where only one phosphorus atom of dppe is coordinated, while the other has been converted to PS, presumably by nucleophilic attack on bridging sulfur. By contrast, the reaction of 1 and 2 with dppm under mild conditions gave only complexes [{mu-(SCH2)(2)CH2}Fe-2(CO)(5)(Ph2PCH2PPh2)] (6) and [{mu-(SCH2)(2)N(CH2CH2CH3)}Fe-2(CO)(5)(Ph2PCH2PPh2)] (8), where one ligand coordinated in a monodentate fashion to one Fe2S2 unit. Furthermore, under forcing conditions, the complexes [{mu-(SCH2)(2)CH2}Fe-2(CO)(4){mu-(Ph2P)(2)CH2}] (7) and [{mu-(SCH2)(2)N(CH2CH2CH3)}Fe-2(CO)(4){mu-(Ph2P)(2)CH2}] (9) were formed, where the phosphine acts as a bidentate ligand, binding to both the iron atoms in the same molecular unit. Electrochemical studies show that the complexes 3, 4, and 9 catalyze the reduction of protons to molecular hydrogen, with 4 electrolyzed already at -1.40 V versus Ag/AgNO3 (-1.0 V vs NHE).
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