We describe reactions of the dilithioallene precursor Li₂(Me₃SiC₃SiMe₃) (1) with Cp₂HfCl₂, which depending on the stoichiometric ratio furnishes either a highly sensitive dinuclear allenediide bridged hafnocene dichloride complex (2-Hf) or a chemically robust dihafnacyclooctatetraene (3-Hf). Both complexes were fully characterized, and their formation was analyzed by in situ NMR spectroscopy. Other than that described before for the Zr analogues, the generation of both isolated complexes occurs via a Li containing, yet structurally elusive, metallocene intermediate.

中文翻译：

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双核阿连二胺桥连铪茂(IV)配合物的合成与表征

我们描述了二锂硫代丙二烯前体 Li ₂ (Me ₃ SiC ₃ SiMe ₃ ) ( 1 ) 与 Cp ₂ HfCl _{2 的反应}，这取决于化学计量比，提供高度敏感的双核丙二烯桥连二氯化铪配合物 ( 2-Hf ) 或化学稳定的二卤环辛四烯 ( 3-Hf )。两种配合物都得到了充分表征，并通过原位核磁共振光谱分析了它们的形成。除了之前描述的 Zr 类似物之外，两种分离的配合物的产生都是通过含有锂但结构上难以捉摸的茂金属中间体发生的。