The bulky substituted cyclopentadienyllithium derivatives, LiC 5 H 4 (CHMeR) (R = C 6 H 5 ( 1 ), 1-naphthyl ( 2 ), 9-anthryl ( 3 )), were synthesized from the reaction of 6-phenylfulvene, 6-(1-naphthyl)fulvene or 6-(9-anthryl)fulvene with LiMe. The ansa -bis(cyclopentadiene) ligands Me 2 Si(C 5 HMe 4 ){C 5 H 4 (CHMeR)} (R = C 6 H 5 ( 4 ), 1-naphthyl ( 5 ), 9-anthryl ( 6 )), and their lithium derivatives Li 2 (Me 2 Si(C 5 Me 4 ){C 5 H 3 (CHMeR)}) (R = C 6 H 5 ( 7 ), 1-naphthyl ( 8 ), 9-anthryl ( 9 )) have been prepared. The zirconocene complexes, [Zr(η 5 -C 5 H 5 ){η 5 -C 5 H 4 - (CHMeR)}Cl 2 ] (R = C 6 H 5 ( 10 ), 1-naphthyl ( 11 ), 9-anthryl ( 12 )) and [Zr{η 5 -C 5 H 4 (CHMeR)} 2 Cl 2 ] (R = C 6 H 5 ( 13 ), 1-naphthyl ( 14 ), 9-anthryl ( 15 )), were synthesized by the reaction of lithium derivatives 1 - 3 and [Zr(η 5 -C 5 H 5 )Cl 3 ] or ZrCl 4 , respectively. The reaction of the lithium ansa -derivatives 7 - 9 and zirconium tetrachloride yielded the ansa -zirconocene complexes, [Zr(Me 2 Si(η 5 -C 5 Me 4 ){η 5 -C 5 H 3 (CHMeR)})Cl 2 ] (R = C 6 H 5 ( 16 ), 1-naphthyl ( 17 ), 9-anthryl ( 18 )). The zirconocene complexes have been tested in the polymerization of ethene and propene. The polymerization of propene with the ansa -zirconocene catalysts 16 - 18 gave polypropylene with 70% mmmm pentads and the symmetric zirconocene catalysts 13 - 15 30-60% mmmm pentads.