Notizen: Preparation of Dimeric [(η5-tBu3Cp)CoBr]2 and Convenient Synthesis of the Homodinuclear Cobalt Complex [(η5-tBu3Cp)Co]2H3 therefrom.

The title compound [(η5-tBu3Cp)CoBr]2 1 is prepared in a one pot reaction starting from 1,2,4- tBu3-cyclopentadiene followed by metallation and by reaction of the resulting tBu3Cp-K+ anion salt with anhydrous CoBr2 in THF. 1 was isolated from this reaction in 78% yield as black crystals. 1 reacts with LiAlH4 in THF at 0 °C. Subsequent alcoholysis of the crude reaction mixture with ethanol at -78 °C gives the novel trihydride cluster [(η5-tBu3Cp)Co]2H3 2 in 58% isolated yield as black crystals. 2 has been characterized by 1H NMR, ESR, MS, and IR spectroscopy, as well as by elemental analysis.