526201-07-0Relevant academic research and scientific papers
Cationic and neutral phosphido-bridged pentamethylcyclopentadienyl-chromium dimers
Wei, Pingrong,Stephan, Douglas W.
, p. 1712 - 1717 (2008/10/08)
The species [(Cp*Cr)2(μ-Cl)3]X (X = [AlCl4] (3), [GaCl4] (4), [B(C6F5)4] (5)) were generated from (Cp*CrCl(μ-Cl))2 (1) via reaction with a chloride abstraction reagent. Using a similar synthetic route, the reaction of 1, generated in situ, with MeLi and the borane B(C6F5)3 gave crystals of the salt [(Cp*Cr)2(μ-Cl)3][MeB(C6 F5)3] (6), while the complex [(Cp*Cr)2(μ-Cl)3][Me2B(C6 F5)2] (7) was obtained, albeit in low yield, from the reaction of [Cp*CrMe(μ-Cl)]2 with HB(C6F5)2. Monoalkylation of 5 with MeLi gave [(Cp*Cr(μ-Cl))2(μ-Me)][B(C6 F5)4] (8), while the related mono(phosphide)-bridged cationic species [(Cp*Cr)2(μ-PPh2) (μ-Cl)2]-[B(C6F5)4] (9) was derived from 5 via reaction with Ph2PLi. The bis(phosphide)-bridged species [(Cp*Cr(μ-PPh2))2(μ-Cl)] [AlMe3Cl] (10) was derived from reaction mixtures of 1, Ph2PLi, and AlMe3, while monoalkylation of 1 with MeLi followed by treatment with Ph2PLi and AlMe3 yielded [(Cp*Cr(μ-PPh2))2(μ-Me)][(Me3 Al)2(μ-Cl)] (11). The neutral phosphide-bridged species (Cp*Cr(μ-PPh2))2(μ-CH2) (12) and (Cp*Cr)2(μ-PPh2)(μ-Cl)(μ-CH2) (13) were obtained from reactions of 1, MeLi, and Ph2PLi. X-ray structural data are reported from compounds 5-13. The synthetic routes and the structural data are discussed.
