Diphenylphosphide-Bridged Diiron Derivatives of [Fe2(5-C5H5)2(g src="http://
详细信息 查看全文
- 作者：Celedonio M. Alvarez ; M. Esther Garcí ; a ; Miguel A. Ruiz ; and Neil G. Connelly
- 刊名：Organometallics
- 出版年：2004
- 出版时间：September 27, 2004
- 年：2004
- 卷：23
- 期：20
- 页码：4750 - 4758
- 全文大小：138K
- 年卷期：v.23,no.20(September 27, 2004)
- ISSN：1520-6041
文摘
The complex trans-[Fe2Cp2(G SRC="/images/entities/mgr.gif">-H)(
ges/entities/mgr.gif">-PPh2)(CO)2] is obtained in 91% yield by refluxing toluenesolutions of [Fe2Cp2(CO)4] (Cp = ges/gifchars/eta.gif" BORDER=0 >5-C5H5) and the secondary phosphine PPh2H. Thiscompound isomerizes upon irradiation with visible-UV light under a CO atmosphere toyield cis-[Fe2Cp2(ges/entities/mgr.gif">-H)(ges/entities/mgr.gif">-PPh2)(CO)2]. The above hydride complexes react under photochemicalconditions with 1 equiv of secondary phosphines PR2H (R = Et, Ph) to give the correspondingmonocarbonyl compounds [Fe2Cp2(ges/entities/mgr.gif">-PPh2)(ges/entities/mgr.gif">-PR2)(ges/entities/mgr.gif">-CO)] via the hydride intermediates [Fe2Cp2(ges/entities/mgr.gif">-H)(ges/entities/mgr.gif">-PPh2)(CO)(PR2H)] (detected and isolated for R = Et). Deprotonation of trans-[Fe2Cp2(ges/entities/mgr.gif">-H)(ges/entities/mgr.gif">-PPh2)(CO)2] with LiBu gives the binuclear anion [Fe2Cp2(ges/entities/mgr.gif">-PPh2)(CO)2]-. Thishighly nucleophilic carbonylate reacts rapidly with [AuCl(PiPr3)] or MeI to give thecorresponding gold diiron cluster [AuFe2Cp2(ges/entities/mgr.gif">-PPh2)(CO)2(PiPr3)] or methyl derivative [Fe2Cp2(Me)(ges/entities/mgr.gif">-PPh2)(ges/entities/mgr.gif">-CO)(CO)2], respectively. Both hydrides cis- and trans-[Fe2Cp2(ges/entities/mgr.gif">-H)(ges/entities/mgr.gif">-PPh2)(CO)2] can be reversibly oxidized at low temperature to the corresponding cation radicalscis- and trans-[Fe2Cp2(ges/entities/mgr.gif">-H)(ges/entities/mgr.gif">-PPh2)(CO)2]+. At room temperature, however, the transdicarbonyl cation isomerizes to its cis isomer, which in turn experiences a degradation processinvolving the reductive elimination of the bridging groups. The structures of the newcomplexes are analyzed on the basis of the corresponding IR and NMR (1H, 31P and 13C)spectroscopic data. The nature of the new radical cations is analyzed also on the basis ofcyclic voltammetry and ESR measurements.