Spectroscopic Studies on Complex Systems

70 dominated in the reaction mixture the assignment of the signals for 69 was confirmed by the in situ synthesis of [Cp2Ti( Li-Me)2AlMe2] [B(C6F5)4] [103]. 

Using C-labelled Cp2Zr( CFl3)2 in combination with MAO at Al/Zr ratios of 10 1 to 40 1, as well as B(C6F5)3 for comparison, Tritto et al. identified compounds 

Whether such products, obtained at high [Zr] after lengthy work-up at room temperature, are characteristic of the species responsible for the high activity of AlBu 3-containing systems under catalytic conditions, i. e. in situ generation at very low [Zr], is not dear at present. However, Bryliakov et al. recently observed the forma- 

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