Abstract 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 ( ...