Abstract: | Polymerization of ethylene and propene were conducted with bis(cyclopentadienylzirconium dichloride) (Cp2ZrCl2) and ethylenebis(1-indenyl)zirconium dichloride (Et(Ind)2ZrCl2) combined with trialkylaluminium compounds using heteropolyacids as the counter-anions, giving linear polyethylene and isotactic polypropene, respectively. No polymer was obtained when using Cp2Zr(CH3)2 instead of Cp2ZrCl2. The mechanism of the formation of active species is briefly discussed on the basis of these results. |