| 摘要 |
Organometallic transition metal compounds of the formula (I) where M<SUP>1 </SUP>is an element of group 3, 4, 5 or 6 of the Periodic Table of the Elements or the lanthanides; X are identical or different and are each halogen, hydrogen, C<SUB>1</SUB>-C<SUB>20</SUB>-alkyl, C<SUB>2</SUB>-C<SUB>20</SUB>-alkenyl, C<SUB>6</SUB>-C<SUB>22</SUB>-aryl, alkylaryl or arylalkyl having from 1 to 10 carbon atoms in the alkyl part and from 6 to 22 carbon atoms in the aryl part, -OR<SUP>5 </SUP>or -NR<SUP>5</SUP>R<SUP>6</SUP>, where two radicals X may also be joined to one another or two radicals X may together form a substituted or unsubstituted diene ligand, in particular a 1,3-diene ligand; where R<SUP>5 </SUP>and R<SUP>6 </SUP>are each C<SUB>1</SUB>-C<SUB>10</SUB>-alkyl, C<SUB>6</SUB>-C<SUB>15</SUB>-aryl, alkylaryl, arylalkyl, fluoroalkyl or fluoroaryl each having from 1 to 10 carbon atoms in the alkyl radical and from 6 to 22 carbon atoms in the aryl radical; n is a natural number from 1 to 4 which is equal to the oxidation number of M<SUP>1 </SUP>minus 2; R<SUP>1 </SUP>is a C<SUB>2</SUB>-C<SUB>40 </SUB>radical which is branched in the alpha position; R<SUP>2 </SUP>is hydrogen or a C<SUB>1</SUB>-C<SUB>40 </SUB>radical which may be branched or unbranched in the alpha position; R<SUP>3</SUP>, R<SUP>3a </SUP>and R<SUP>3b </SUP>are identical or different and are each hydrogen or a C<SUB>1</SUB>-C<SUB>40 </SUB>radical, where at least one of the radicals R<SUP>3</SUP>, R<SUP>3a</SUP>, R<SUP>3b </SUP>is not hydrogen; R<SUP>4 </SUP>is a substituted or unsubstituted C<SUB>6</SUB>-C<SUB>40</SUB>-aryl radical or C<SUB>2</SUB>-C<SUB>40</SUB>-heteroaromatic radical containing at least one heteroatom selected from the group consisting of O, N, S and P; T is a divalent C<SUB>1</SUB>-C<SUB>40 </SUB>group which together with the cyclopentadienyl ring forms a further saturated or unsaturated ring system having a ring size of from 5 to 12 atoms, where T may contain the heteroatoms Si, Ge, N, P, O or S withing the ring system fused onto the cyclopentadienyl ring; and Z is a bridge consisting of a divalent atom or a divalent group, can be used in catalyst systems for preparing polyolefins by polymerization or copolymerization of at least one olefin. Biscyclopentadienyl ligand systems which have such a substitution pattern and can be used for preparing these organometallic transition metal compounds are also provided |
