| abstract |
Metallocenes containing ligands of 2-substituted indenyl derivatives, process for their preparation, and their use as catalysts in the polymerization of olefins. The novel metallocenes of the formula I in which, preferably, M1 is Zr or Hf, R1 and R2 are alkyl or halogen, R3 and R4 are hydrogen, R5 and R6 are alkyl or haloalkyl, -(CR8R9)m-R7-(CR8R9)n- is a single- or multi-membered chain in which R7 may also be a (substituted) hetero atom, m + n is zero or 1, and R10 is hydrogen, form, together with aluminoxanes as cocatalysts, a very effective catalyst system for the preparation of polyolefins of high stereospecificity and high melting point. |