The reaction of [η5:C5H4–(CH2)n–C6H5]2MCl2 complexes (n=1–5; M=Zr, Hf) with EtLi

The reaction of metallocene complexes of the type [η5:C5H4–(CH2)n–C6H5]2MCl2 (n=1–5; M=Zr, Hf) with EtLi gives the mono nuclear ethyl derivatives [η5:C5H4–(CH2)n–C6H5]2M(Et)Cl and the metallacycles [η5:C5H4–(CH2)n–C6H5][η5:C5H4–(CH2)n–η1:C6H4]MEt. A large excess of EtLi affords the dinuclear species [η5:C5H4–(CH2)n–η6:C6H5]2M2Cl2 (n=2–5). All types of complexes can be activated with methylalumoxane (MAO) and then be used for catalytic polymerization of ethylene.