Effect of Metallocene Structures on their Performance in Ethene Polymerisation

Six (Cp)(4‐phenyl‐indenyl)MCl2 (A) and four (Cp)(1‐phenyl‐indenyl)MCl2 (C) (M = Zr/Hf) based complexes were tested in ethene homo‐ and copolymerisation under different conditions to explain how the differences in the complex structure affect the polymerisation process and the formed polymer. Polymerisation experiments reveal that hafnocene catalysts need a higher amount of MAO to reach the maximum activity than zirconocenes. Hafnocenes also incorporate better 1‐hexene. Catalysts with the Cp* or 1,2,4‐Me3Cp ligand show higher activity, and work well with [HNMe2Ph][B(C6F5)4]/TIBA as cocatalyst, but produce polymers with lower $\overline M _{\rm n} $ than the corresponding catalyst with a plain Cp ligand. The Cp* ligand seems to prevent 1‐hexene incorporation. A methyl group in the 2‐position of (Cp)(4‐PhInd)ZrCl2 decreases the activity and $\overline M _{\rm n} $ but favours 1‐hexene insertion. Polymerisation activity is higher with catalysts with a 1‐PhInd‐ligand than with a 4‐PhInd‐ligand.