Catalyst system for preparing isotactic polyolefins, is obtainable by reacting chiral transition metal compounds having two bidentate chelating ligands connected to one another via bridge and further monodentate ligand, and cocatalysts

摘要

A catalyst system is obtainable by reacting chiral transition metal compound(s) and cocatalyst(s) to convert the chiral transition metal compound into a cation. The chiral transition metal compound contains two bidentate chelating ligands connected to one another via a bridge and, if desired, further monodentate ligand(s). A catalyst system for preparing isotactic polyolefins is obtainable by reacting chiral transition metal compound(s) and cocatalyst(s) to convert the chiral transition metal compound into a cation. The chiral transition metal compound contains two bidentate chelating ligands connected to one another via a bridge and, if desired, further monodentate ligand(s). The four coordinating atoms of the two chelating ligands are in an approximately planar arrangement around the transition metal ion and up to two further ligands located above and below this approximately planar coordination sphere formed by the four coordinating atoms of the two chelating ligands and, in the case of two further ligands, these being in the transposition relative to one another. Independent claims are also included for: (a) use of a chiral transition metal compound of structure (Ib) or one of its enantiomers of structure (Ib*) for preparing a catalyst system for the polymerization of olefins; (b) a process for preparing the inventive catalyst system for olefin polymerization, comprising contacting transition metal compound(s) of structures (Ib) or (Ib*) with cation-forming compound(s); (c) a process for preparing isotactic polyolefins by polymerization of alpha -olefin(s) in the presence of the inventive catalyst system; (d) a polyolefin obtained by the above process; (e) a polyolefin composition comprising the above polyolefin; and (f) a film, fiber, or molding produced from the polyolefin composition. [Image] M : zirconium or hafnium.