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• 作者：Celedonio M. Alvarez ; M. Esther Garc&iacute ; a ; M. Teresa Rueda ; Miguel A. Ruiz ; David Sá ; ez ; and Neil G. Connelly
• 刊名：Organometallics
• 出版年：2005
• 出版时间：February 14, 2005
• 年：2005
• 卷：24
• 期：4
• 页码：650 - 658
• 全文大小：163K
• 年卷期：v.24,no.4(February 14, 2005)
• ISSN：1520-6041

文摘

Reaction of the hydride complexes [M₂Cp₂(mages/entities/mgr.gif">-H)(mages/entities/mgr.gif">-PPh₂)(CO)₄] (M = Mo, W; Cp = mages/gifchars/eta.gif" BORDER=0 >⁵-C₅H₅)with [FeCp₂]BF₄ proceeds in a 1:2 ratio to give the unsaturated tetracarbonyl salts [M₂Cp₂(mages/entities/mgr.gif">-PPh₂)(CO)₄]BF₄, which spontaneously (M = Mo) or in the presence of CO (M = W)transform into the corresponding electron-precise pentacarbonyls [M₂Cp₂(mages/entities/mgr.gif">-PPh₂)(mages/entities/mgr.gif">-CO)(CO)₄]BF₄. In contrast, reaction of the above hydride complexes with [FeCp₂](BAr'₄) (Ar' =3,5-C₆H₃(CF₃)₂) proceeds in a 1:1 ratio to give the paramagnetic salts [M₂Cp₂(mages/entities/mgr.gif">-H)(mages/entities/mgr.gif">-PPh₂)(CO)₄](BAr'₄). No further reaction takes place with [FeCp₂](BAr'₄) unless a proton acceptorsuch as water or tetrahydrofuran is present, in which case the corresponding salts [M₂Cp₂(mages/entities/mgr.gif">-PPh₂)(CO)₄](BAr'₄) or [M₂Cp₂(mages/entities/mgr.gif">-PPh₂)(mages/entities/mgr.gif">-CO)(CO)₄](BAr'₄) are rapidly formed. Reactionsof the anions [M₂Cp₂(mages/entities/mgr.gif">-PPh₂)(CO)₄]^- (as (H-DBU)⁺ salts, DBU = 1,8-diazabicyclo[5.4.0]undec-7-ene) with [FeCp₂]BF₄ proceed stepwise to give first the 33-electron radicals [M₂Cp₂(mages/entities/mgr.gif">-PPh₂)(CO)₄], which can be isolated as very air-sensitive green solids, and then theunsaturated salts [M₂Cp₂(mages/entities/mgr.gif">-PPh₂)(CO)₄]BF₄, which are identical to those formed from theneutral hydrides. The structure and dynamic behavior of the new compounds are analyzedon the basis of solution IR, ¹H, ³¹P, and ¹³C NMR or ESR spectroscopic data. In addition,the redox and other chemical transformations connecting all the new compounds arediscussed on the basis of the synthetic and structural data, as well as cyclic voltammetrymeasurements carried out in dichloromethane on the neutral hydrides [M₂Cp₂(mages/entities/mgr.gif">-H)(mages/entities/mgr.gif">-PPh₂)(CO)₄] and the anions [M₂Cp₂(mages/entities/mgr.gif">-PPh₂)(CO)₄]^- (as [N(PPh₃)₂]⁺ salts).