Process for preparing low molecular weight olefin polymers, organometallic transition metal compounds biscyclopentadienyl ligand systems and catalyst systems

摘要

The present invention relates to a process for preparing olefin polymers having a molar mass M_w of from 500 to 50 000 g/mol by polymerization or copolymerization of at least one olefin of the formula R^a—CH═CH—R^b, where R^a and R^b are identical or different and are each a hydrogen atom or a hydrocarbon radical having from 1 to 20 carbon atoms, or R^a and R^b together with the atoms connecting them can form a ring, at a temperature of from −60 to 200° C. and a pressure of from 0.5 to 100 bar, in solution, in suspension or in the gas phase, in the presence of hydrogen and in the presence of a catalyst system comprising at least one organometallic transition metal compound and at least one cocatalyst, wherein the organometallic transition metal compound is a compound of the formula (I), specific organometallic transition metal compounds, biscyclopentadienyl ligand systems having such a specific substitution pattern, catalyst systems comprising at least one of the organometallic transition metal compounds of the invention and the use of the biscyclopentadienyl ligand systems of the invention for preparing organometallic transition metal compounds.;