Diferrous Cyanides as Models for the Fe-only Hydrogenases
详细信息 查看全文
- 作者：Christine A. Boyke ; Jarl Ivar van der Vlugt ; Thomas B. Rauchfuss ; Scott R. Wilson ; Giuseppe Zampella ; and Luca De Gioia
- 刊名：Journal of the American Chemical Society
- 出版年：2005
- 出版时间：August 10, 2005
- 年：2005
- 卷：127
- 期：31
- 页码：11010 - 11018
- 全文大小：499K
- 年卷期：v.127,no.31(August 10, 2005)
- ISSN：1520-5126
文摘
The first systematic study of diferrous dicyano dithiolates is described. Oxidation of[Fe2(S2C2H4)(CN)2(CO)4]2- in the presence of cyanide and tertiary phosphines and of Fe2(S2C2H4)(CO)4(PMe3)2 in the presence of cyanide affords a series of diferrous cyanide derivatives that bear astoichiometric, structural, and electronic relationship to the Hoxair state of the Fe-only hydrogenases. WithPPh3 as the trapping ligand, we obtained an unsymmetrical isomer of Fe2(S2C2H4)(
ages/entities/mgr.gif">-CO)(CN)2(PPh3)2(CO)2, as confirmed crystallographically. This diferrous cyanide features the semibridging CO-ligand, withFe-ages/entities/mgr.gif">C bond lengths of 2.15 and 1.85 Å. Four isomers of Fe2(S2C2H4)(ages/entities/mgr.gif">-CO)(CN)2(PMe3)2(CO)2 wereobserved, the initial product again being unsymmetrical but more stable isomers being symmetrical. DFTcalculations confirm that the most stable isomers of Fe2(S2C2H4)(ages/entities/mgr.gif">-CO)(CN)2(PMe3)2(CO)2 have cyanidetrans to ages/entities/mgr.gif">-CO. Oxidative decarbonylation also afforded the new tetracyanide [Fe2(S2C2H4)(ages/entities/mgr.gif">-CO)(CN)4(CO)2]2-. Insights into the oxidative decarbonylation mechanism of these syntheses come from thespectroscopic characterization of the tetracarbonyl [Fe2(S2C2H4)(ages/entities/mgr.gif">-CO)(CN)3(CO)3]-. This species reactswith PEt3 to produce the stable adduct [Fe2(S2C2H4)(ages/entities/mgr.gif">-CO)(CN)3(CO)2(PEt3)]-.