149342-08-5Relevant articles and documents
MESO-SELECTIVE SYNTHESIS OF ANSA-METALLOCENES
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Page/Page column 16-17, (2008/06/13)
The present invention relates to a process for the meso-selective preparation of ansa-metallocene complexes of the formula (I), which comprises reacting a ligand starting compound of the formula (II) with a transition metal compound of the formula III, where R1, R1 are identical or different and are each hydrogen or an organic radical having from 1to 40 carbon atoms, R2, R2 are identical or different and are each hydrogen or an organic radical having from 1 to 40 carbon atoms, R3 is a bulky organic radical which has at least 3 carbon atoms, is bound to the oxygen atom via a nonaromatic carbon or silicon atom and may be substituted by halogen atoms or further organic radicals having from 1 to 20 carbon atoms and may also contain heteroatoms selected from the group consisting of Si, N, P, O and S, T, T’ are identical or different and are each a divalent organic group which has from 1 to 40 carbon atoms and together with the cyclopentadienyl ring forms at least one further saturated or unsaturated, substituted or unsubstituted ring system having a ring size of from 5 to 12 atoms, where T and T’ may contain the heteroatoms Si, Ge, N, P, As, Sb, O, S, Se or Te within the ring system fused to the cyclopentadienyl ring, A is a bridge consisting of a divalent atom or a divalent group, M1 is an element of group 3, 4, 5 or 6 of the Periodic Table of the Elements or the lanthanides, the radicals X are identical or different and are each an organic or inorganic radical which is able to be replaced by a cyclopentadienyl anion, x is a natural number from 1 to 4, M2 is an alkali metal, an alkaline earth metal or a magnesium monohalide fragment, p is 1 in the case of doubly positively charged metal ions or 2 in the case of singly positively charged metal ions or metal ion fragments, LB is an uncharged Lewis base ligand, and y is a natural number from 0 to 6, and also the subsequent reaction of these complexes to form ansa-metallocenes of the formula (IV), the use of transition metal compounds of the formula (III) for preparing metallocenes and also transition metal compounds of the formula (III), ansa-metallocene complexes of the formula (I) and the use of these as constituents of catalyst systems for the polymerization of olefines.
