Copolymerization of ethylene and 1‐decene by metallocenes: Direct comparison of Me 2 C(Cp)(Flu)ZrMe 2 with Et(Cp)(Flu)ZrMe 2

Copolymerizations of ethylene with 1‐decene have been carried out by using two syndiospecific metallocenes synthesized by modifying the bridge: highly syndiospecific isopropylidene(1‐η 5 ‐cyclopentadienyl)(1‐η 5 ‐fluorenyl)‐dimethylzirconium (Me 2 C(Cp)(Flu)ZrMe 2 , 1 ) and less syndiospecific (1‐fluorenyl‐2‐cyclopentadienylethane)‐dimethylzirconium (Et(Cp)(Flu)ZrMe 2 , 2 ), in the presence of [Ph 3 C][B(C 6 F 5 ) 4 ] as a cocatalyst. The ethano bridged 2 compound of smaller dihedral angle showed much higher activity than 1 compound. The catalytic activities of the two compounds were enhanced about twice when a suitable amount of 1‐decene comonomer is present in the feed. The compound 1 showed better comonomer reactivity than 2 . The properties ( T m , density, and crystallinity) of copolymers seem not to be affected by the type of bridge of the metallocenes, and mainly depend on 1‐decene content in the copolymer.