Organometallic transition metal compound, biscyclopentadienyl ligand system, catalyst system and process for preparing polyolefins

A process for preparing an organometallic transition metal compound, which comprises reacting a biscyclopentadienyl ligand system or a bisanion prepared therefrom with a transition metal compound, the biscyclopentadienyl ligand system comprising a compound of formula (II):

• or its double bond isomers.
• where
• R1 is hydrogen or a cyclic, branched or unbranched C1-C20-alkyl radical, a C2-C20-alkenyl radical, an arylalkyl radical having from 1 to 10 carbon atoms in the alkyl part and from 6 to 22 carbon atoms in the aryl part or a C4-C24-heteroaromatic radical selected from the group consisting of substituted or unsubstituted thienyl radicals or of substituted or unsubstituted furyl radicals,
• R2 is a substituted or unsubstituted C6-C40-aryl radical,
• R3 is hydrogen or a cyclic, branched or unbranched C1-C20-alky radical, C2-C20-alkenyl radical, an arylalkyl radical having from 1 to 10 carbon atoms in the alkyl part and from 6 to 22 carbon atoms in the aryl part, or the radicals R2 and R3 to together form a ring system,
• R4 is hydrogen or a cyclic, branched or unbranched C1-C20-alky radical, a C2-C20-alkenyl radical, an arylalkyl radical having from 1 to 10 carbon atoms in the alkyl part and from 6 to 22 carbon atoms in the aryl part,
• R5 is a cyclic, branched or unbranched C1-C20-alkyl radical, a C2-C20-alkenyl radical, an arylalkyl radical having from 1 to 10 carbon atoms in the alkyl part and from 6 to 22 carbon atoms in the aryl part, and
• Z is a divalent group CR8R9—CR10R11, where R8, R9, R10 and R11 are identical or different and are each hydrogen or a trimethylsilyl group, a C1-C10-alkyl group, a C1-C10-fluoroalkyl group, a C6-C10-fluoroaryl group, a C6-C10-aryl group, a C8-C40-arylalkenyl group, a C7-C40-arylalkyl group or a C7-C40-alkylaryl group or two adjacent radicals together with the atoms connecting them form a saturated or unsaturated ring having from 4 to 15 carbon atoms.

A biscyclopentadienyl ligand system of formula (II):

• or its double bond isomers,
• where
• R1 is hydrogen or a cyclic, branched or unbranched C1-C20-alkyl radical, a C2-C20-alkenyl radical, an arylalkyl radical having from 1 to 10 carbon atoms in the alkyl part and from 6 to 22 carbon atoms in the aryl part or a C4-C24 heteroaromatic radical selected from the group consisting of substituted or unsubstituted thienyl radicals or of substituted or unsubstituted furyl radicals,
• R2 is a substituted or unsubstituted C6-C40-aryl radical,
• R3 is hydrogen or a cyclic, branched or unbranched C1-C20-alkyl radical, C2-C20-alkenyl radical, an arylalkyl radical having from 1 to 10 carbon atoms in the alkyl part and from 6 to 22 carbon atoms in the aryl part, or the radicals R2 and R3 together form a ring system,
• R4 is hydrogen or a cyclic, branched or unbranched C1-C20-alkyl radical, a C2-C20-alkenyl radical, an arylalkyl radical having from 1 to 10 carbon atoms in the alkyl part and from 6 to 22 carbon atoms in the aryl part,
• R5 is a cyclic, branched or unbranched C1-C20-alkyl radical, a C2-C20-alkenyl radical, an arylalkyl radical having from 1 to 10 carbon atoms in the alkyl part and from 6 to 22 carbon atoms in the aryl part, and
• Z is a divalent group CR8R9—CR10R11, where R8, R9, R10 and R11 are identical or different and are each hydrogen or a trimethylsilyl group, a C1-C10-alkyl group, a C1-C10-fluoroalkyl group, a C6-C10-fluoroaryl group, a C6-C10-aryl group, a C8-C40-arylalkenyl group, a C7-C40-arylalkyl group or a C7-C40-alkylaryl group or two adjacent radicals together with the atoms connecting them form a saturated or unsaturated ring having from 4 to 15 carbon atoms.