Bis (pentamethylcyclopentadieny1) hafnium dichloride (Cp*, HfClz, Cp*= q5-CsMe6) is obtained by treatment of HfC14 with lithium pentamethylcyclopentadienide in refluxing xylenes. The dioodide derivative is obtained from Cp*, HfClz with BIB. The dihydrido derivative is obtained via treatment of Cp* 2HfClz with n-butyllithium under an atmosphere of H2 Treatment of Cp*, HfHz with alkyl halides (RX) affords either Cp* &fX2 or Cp*, HfHX ...