Fluoro Complexes of Permethyltantalocene, Cp*<sub>2</sub>TaF<sub>3</sub> and [Cp*<sub>2</sub>TaF<sub>2</sub>][BF<sub>4</sub>]: Facile Formation of a Tetrafluoroborate Complex via Corrosion of Borosilicate Glass
作者:Jun Ho Shin、Gerard Parkin
DOI:10.1021/om980549v
日期:1998.12.1
The trihydride complex Cp*2TaH3 is a convenient precursor to a series of halide derivatives, which include unusual examples of organometallic fluoride complexes. Most interestingly, reaction of Cp*2TaH3 with (C5H5N)(HF)(x) affords the trifluoride complex Cp*2TaF3 when carried out in a plastic vessel, but the tetrafluoroborate complex [Cp*2TaF2][BF4] when performed ina borosilicate glass vessel. In contrast, reaction of Cp*2TaH3 with [Et3N(HF)(3)] results in cleavage of one of the pentamethylcyclopentadienyl ligands to yield the half-sandwich complex [Et3NH][Cp*TaF5]. Cp*2TaF3 and [Cp*2TaF2][BF4] may be readily interconverted. Thus, treatment of Cp*2TaF3 with either Et2O . BF3 or LiBF4 yields [Cp*2TaF2][BF4], while reaction of the latter complex with excess NaF regenerates Cp*2TaF3. Furthermore, Cp*2TaF3 is converted to the cyano fluoride complex Cp*Ta-2(CN)(2)F upon reaction with excess Me3SiCN. Sequential replacement of the hydride ligands of Cp*2TaH3 is observed in the reaction with Mel to give Cp*2TaH2I and Cp-2*TaHI2; likewise, the reactions of Cp*2TaH3 with either HCl, CHCl3, pr CCl4 give Cp*2TaH2Cl and Cp*2TaHCl2. The molecular structures of [Cp*2TaF2][BF4], [Et3NH][Cp*TaF5], and Cp*2TaHCl2 have been determined by X-ray diffraction.