Organometallic Zirconium and Hafnium Complexes

Photolysis of a solution of biscyclo-octatetraenylzirconium in THF in the presence of HCl affords dichlorocyclo-octatetraenylzirconium,THF. X-Ray diffraction shows the cyclo-octatetraenyl ligand to be planar. 

curves have been obtained for Cp2ZrR2 (R = H, Me, or Cp2ZrMe2 

A variety of mixed zirconium-aluminium alkyl complexes have been described. 

Continuing studies of the hydrozirconation system Cp2Zr(Cl)H illustrate its versatility. For example, chloro-olefins such as 4-chlorocyclohexane react to give moderate yields of bicyclo[3,l,0]hexane. Ring formation is believed to occur via Zr—X y-elimination. y5-Unsaturated aldehydes and halides have been obtained from CO insertion into the Zr—C bonds of intermediates obtained from 1,3-dienes and Cp2Zr(Cl)H.3  

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