Reactions of alkaline earth metal or al slurries with bis-cyclopentadienyl complexes of some early transition metals

Slurries of Mg, Ca, Ba and Al, prepared by cocondensation of metal vapour with volatile organic solvents, especially toluene, at -196°C, reacted at ambient temperature with some bis-cyclopentadienyl complexes of Ti, Zr, Hf, V and Cr. [TiCl₂Cp₂] (Cp = ?⁵-C₅H₅) with slurries Al in hexane or toluene, or Mg or Ba, in toluene, formed [TiClCp₂]₂ accompanied by side-products. From related reactions with slurries of Mg in tetrahydrofuran (THF), [TiCl₂Cp(THF)] was obtained and with Ca-toluene slurries an unstable paramagnetic dihydrido complex of Ti(III) was observed by using ESR spectroscopy. Reactions of [TiPh₂Cp₂ with slurries of Al or Ba in toluene yielded a form of "titanocene" (TiC₁₀H₁₀) and ESR studies of these reactions revealed related paramagnetic species in solution. Reaction of slurries of Al, Mg or Ba with [TiMe₂Cp₂] produced several different paramagnetic products which were studied by ESR spectroscopy, and the reaction of metal slurries with the complexes [MR₂Cp₂] (M = Ti, R = OPh; M = Zr or Hf, R = Cl or Me), [VRCp₂] (R = Cl or Me), and [CrCp₂] are also reported. © 1986.