Chemistry of Highly Electrophilic Binuclear Cations. 2. Oxidation Reactions of [W 2 ( η 5 -C 5 H 5 ) 2 (CO) 4 ( μ -Ph 2 PCH 2 PPh 2 )] with [FeCp 2 ][B{3,5-C 6 H 3 (CF 3 ) 2 } 4 ]

Chemical oxidation of the title compound [W 2 Cp 2 (CO) 4 (μ-dppm)] (Cp = η 5 -C 5 H 5; dppm = Ph 2 PCH 2 PPh 2 ) with 1 equiv of [FeCp 2 ](BAr‘ 4 ) (Ar‘ = 3,5-C 6 H 3 (CF 3 ) 2 ) leads to the tetracarbonyl radical [W 2 Cp 2 (CO) 4 (μ-dppm)](BAr‘ 4 ), which experiences spontaneous decarbonylation to give the 31-electron radical [W 2 Cp 2 (μ-CO)(CO) 2 (μ-dppm)](BAr‘ 4 ). Oxidation of [W 2 Cp 2 (CO) 4 (μ-dppm)] with 2 equiv of [FeCp 2 ](BAr‘ 4 ) gives the tricarbonyl derivative [W 2 Cp 2 (μ-CO)(CO) 2 (μ-dppm)](BAr‘ 4 ) 2 . The same result is obtained when oxidizing the radical [W 2 Cp 2 (μ-CO)(CO) 2 (μ-dppm)](BAr‘ 4 ) with [FeCp 2 ](BAr‘ 4 ). The triply bonded complex [W 2 Cp 2 (μ-CO)(CO) 2 (μ-dppm)](BAr‘ 4 ) 2, which displays fluxional behavior in solution, reacts with P(OMe) 3 to give [W 2 Cp 2 (μ-CO)(CO){P(OMe) 3 }(μ-dppm)](BAr‘ 4 ) 2, the structure of which has been solved through a single-crystal X-ray diffraction study. Reaction of [W 2 Cp 2 (μ-CO)(CO) 2 (μ-dppm)](BAr‘ 4 ) 2 with salts of halide ions X - (X = Cl, Br, I) gives the corresponding halo derivatives [W 2 Cp 2 (μ-X)(μ-CO)(CO) 2 (μ-dppm)](BAr‘ 4 ). When X = I, a mixture of two isomers differing in the relative positions of the bridging halide and carbonyl is obtained. The same halide compounds were obtained in the reactions of paramagnetic [W 2 Cp 2 (μ-CO)(CO) 2 (μ-dppm)](BAr‘ 4 ) with halogens X 2 . The tricarbonyl radical was found to react slowly with water to give the known hydroxycarbyne derivative [W 2 Cp 2 (μ-COH)(CO) 2 (μ-dppm)](BAr‘ 4 ).