1,3-disubstituted indene complexes
AssigneeBayer Aktiengesellschaft
InventorsSigurd Becke, Thomas Weiss, Heinrich Lang
Life of this patent
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Abstract
The present invention relates to organometallic compounds of transition metals with an indenyl ligand bonded in the 2-position and substituted in the 1,3-position, a process for their production, and their use as catalysts for the (co)polymerization of olefinic and/or diolefinic monomers.
Claims18
A process for the production of organometallic compounds of transition metals with 2-indenyl as ligand disubstituted in the 1,3-position, that correspond to the general formula (I),
- wherein
- A denotes the benzo system or the tetrahydrocyclohexyl system,
- Q1, Q2 are identical or different and, as substituent of the 2-indenyl system substituted in the 1,3-position, denote hydrogen, C1-C4-alkyl, C6-C14-aryl, C7-C10-aralkyl, C1-C4-alkoxy, C1-C4-alkylthio, phenoxy, phenylthio, di-C1-C4-alkylamino, C6-C14-aryl-C1-C4-alkylamino, di-C6-C14-arylamino, dibenzylamino, tri-C1-C4-alkylsilyl, di-C1-C4-alkylboranyl, phenyl-C1-C4-alkylboranyl, diphenylboranyl, di-C1-C4-alkylphosphoryl, diphenylphosphoryl or phenyl-C1-C4-alkylphos-phoryl,
- Q3 are identical or different and, as substituent of the 2-indenyl system substituted in the 4,5,6,7-position, denote hydrogen, C1-C4-alkyl, C6-C14-aryl, C7-C10-aralkyl, C1-C4-alkoxy, C1-C4-alkylthio, phenoxy, phenylthio, di-C1-C4-alkylamino, C6-C14-aryl-C1-C4-alkylamino, di-C6-C14-arylamino, dibenzylamino, tri-C1-C4-alkylsilyl, di-C1-C4-alkylboranyl, phenyl-C1-C4-alkylboranyl, diphenylboranyl, di-C1-C4-alkylphosphoryl, diphenylphosphoryl or phenyl-C1-C4-alkylphosphoryl,
- M1 is a transition metal from Group IV, V or VI of the Periodic System of the Elements according to IUPAC 1985,
- X denotes an anion,
- n is a number from zero to 4 that is determined by the valency and the bonding state of M1,
- m is a number from zero to 4 that is determined by the number of the radicals Q3,
- Y is a bridge selected from the group consisting of —C(R1R2)—, —Si(R1R2)—, —Ge(R1R2)—, —C(R1R2)—C(R3R4)—, —C(R1R2)—Si(R3R4)— or —Si(R1R2)—Si(R3R4)—, wherein R1, R2, R3 and R4 independently of one another denote hydrogen, halogen, straight-chain or branched C1-C10-alkyl, C5-C8-cycloalkyl, C6-C14-aryl or C7-C10-aralkyl, and
- Z is a second ligand from the group of open-chain and cyclic, optionally anionic π-systems, —N(R5)—, —P(R6)—, |N(R5R7)—, |P(R6R8)—, —O—, —S—, |OR5— or |SR5—, wherein the vertical lines to the left of the element symbol N, P, O and S denotes an electron pair, and the bonding between Z and M1 is ionic, covalent or co-ordinative, and wherein R5, R6, R7 and R8 independently of one another have the same range of meanings as R1 to R4, and R5 and R7 may, in addition denote —Si(R1R2R3), and R6 and R8 may in addition denote —Si(R1R2R3), —OR1, —SR1— or —N(R1R2),
- comprising the step of reacting a halogenated indene substituted in the 1,3-position of the formula
- in which Hal1 denotes Cl, Br or I and Q1, Q2 and Q3 have the above meanings,
- with an elementary metal selected from Groups I, II or XII of the Periodic System according to IUPAC 1985 or a corresponding metal compound in an amount in the range from 1 to 100 moles of elementary metal/metal compound per mole of (II) and with a dihalide of the bridge Y of the formula
- Hal2—Y—Hal3 (III),
- in which
- Hal2 and Hal3 independently of one another denote Cl, Br or I and
- Y has the above range of meanings,
- in an amount of 1 to 20 moles of (III) per mole of (II), wherein if Y has the meaning —Si(R1R2)—, —Ge(R1R2)— or —Si(R1R2)—Si(R3R4)—, the reaction of (II) with (i) elementary metal/metal compound, and of (ii) with (III) may also take place simultaneously, and the reaction product of the formula
- wherein Q1, Q2, Q3, Y, Hal3 and m have the above meanings,
- is reacted, optionally after it has been separated, with a Z derivative of the formula
- ZM2p (Va)
- or
- ZR9p (Vb),
- in which
- M2 denotes Li, Na, K or —MgHal4, wherein Hal4 has the range of meanings of Hal2,
- p represents the number 1 or 2,
- R9 denotes hydrogen, —Si(R1R2R3) or —Sn(R1R2R3), and
- Z, R1, R2 and R3 have the above meanings,
- with the release of a compound of the formula
- M2Hal3 (VIa)
- or
- R9Hal3 (VIb),
- in which M2, R9 and Hal3 have the above meanings,
- optionally in the presence of an auxiliary base to form the 2-indenyl compound of the formula
- in which Q1, Q2, Q3, Y, Z and m have the above meanings and which may be present as a dianion, and in which Z may, furthermore, carry M2, R9 or an electron pair,
- and is then reacted further with a transition metal compound of the formula
- M1Xq (VIII),
- in which
- M1 and X have the above meanings and
- q is a number from 2 to 6 that is determined by the oxidation state of M1.
Organometallic compounds of transition metals with 2-indenyl as ligand substituted in the 1,3-position, that correspond to the general formula (I)
- wherein
- A denotes the benzo system or the tetrahydrocyclohexyl system,
- Q1, Q2are identical or different and, as substituent of the 2-indenyl system substituted in the 1,3-position, denote hydrogen, C1-C4-alkyl, C6-C14-aryl, C7-C10-aralkyl, C1-C4-alkoxy, C1-C4-alkylthio, phenoxy, phenylthio, di-C1-C4-alkylamino, C6-C14-aryl-C1-C4-alkylamino, di-C6-C14-arylamino, dibenzylamino, tri-C1-C4-alkylsilyl, di-C1-C4-alkylboranyl, phenyl-C1-C4-alkylboranyl, diphenylboranyl, di-C1-C4-alkylphosphoryl, diphenylphosphoryl or phenyl-C1-C4-alkylphosphoryl,
- Q3are identical or different and, as substituent of the 2-indenyl system substituted in the 4,5,6,7-position, denote hydrogen, C1-C4-alkyl, C6-C14-aryl, C7-C10-aralkyl, C1-C4-alkoxy, C1-C4-alkylthio, phenoxy, phenylthio, di-C1-C4-alkylamino, C6-C14-aryl-C1-C4-alkylamino, di-C6-C14-arylamino, dibenzylamino, tri-C1-C4-alkylsilyl, di-C1-C4-alkylboranyl, phenyl-C1-C4-alkylboranyl, diphenylboranyl, di-C1-C4-alkylphosphoryl, diphenylphosphoryl or phenyl-C1-C4-alkylphosphoryl,
- M1 is a transition metal from Group IV, V or VI of the Periodic System of the Elements according to IUPAC 1985,
- X denotes an anion,
- n is a number from zero to 4 that is determined by the valency and the bonding state of M1,
- m is a number from zero to 4 that is determined by the number of the radicals Q3,
- Y is a bridge selected from the group consisting of —C(R1R2)—, —Si(R1R2)—, —Ge(R1R2)—, —C(R1R2)—C(R3R4)—, —C(R1R2)—Si(R3R4)— or —Si(R1R2)—Si(R3R 4)—, wherein R1, R2, R3 and R4 independently of one another denote hydrogen, halogen, straight-chain or branched C1-C10-alkyl, C5-C8-cycloalkyl, C6-C14-aryl or C7-C10-aralkyl, and
- Z is a second ligand from the group of open-chain and cyclic, optionally anionic π-systems, —N(R5)—, —P(R6)—, |N(R5R7)—, |P(R6R8)—, —O—, —S—, |OR5— or |SR5—, wherein the vertical lines to the left of the element symbol N, P, O and S denotes an electron pair, and the bonding between Z and M1 is ionic, covalent or co-ordinative, and wherein R5, R6, R7 and R8 independently of one another have the same range of meanings as R1 to R4, and R5 and R7 may in addition denote —Si(R1R2R3), and R6 and R8 may in addition denote —Si(R1R2R3), —OR1, —SR1 or —N(R1R2).
Intermediate products of the formula
- in which
- Q1, Q2are identical or different and, as substituent of the 2-indenyl system substituted in the 1,3-position, denote hydrogen, C1-C4-alkyl, C6-C14-aryl, C7-C10-aralkyl, C1-C4-alkoxy, C1-C4-alkylthio, phenoxy, phenylthio, di-C1-C4-alkylamino, C6-C14-aryl-C1-C4-alkylamino, di-C6-C14-arylamino, dibenzylamino, tri-C1-C4-alkylsilyl, di-C1-C4-alkylboranyl, phenyl-C1-C4-alkylboranyl, diphenylboranyl, di-C1-C4-alkylphosphoryl, diphenyiphosphoryl or phenyl-C1-C4-alkylphosphoryl,
- Q3 are identical or different and, as substituent of the 2-indenyl system substituted in the 4,5,6,7-position, denote hydrogen, C1-C4-alkyl, C6-C14-aryl, C7-C10-aralkyl, C1-C4-alkoxy, C1-C4-alkylthio, phenoxy, phenylthio, di-C1-C4-alkylamino, C6-C14-aryl-C1-C4-alkylamino, di-C6-C14-arylamino, dibenzylamino, tri-C1-C4-alkylsilyl, di-C1-C4-alkylboranyl, phenyl-C1-C4-alkylboranyl, diphenylboranyl, di-C1-C4-alkylphosphoryl, diphenylphosphoryl or phenyl-C1-C4-alkylphosphoryl,
- m is a number from zero to 4 that is determined by the number of the radicals Q3,
- Y is a bridge from the group consisting of —C(R1R2)—, —Si(R1R2)—, —Ge(R1R2)—, —C(R1R2)—C(R3R4)—, —C(R1R2)—Si(R3R4)— or —Si(R1R2)—Si(R3R4)—, wherein R1, R2, R3 and R4 independently of one another denote hydrogen, halogen, straight-chain or branched C1-C10-alkyl, C5-C8-cycloalkyl, C6-C14-aryl or C7-C10-aralkyl, and
- Hal3 denotes Cl, Br or I.
A process for the production of Intermediate products of the formula
- in which
- Q1, Q2 are identical or different and, as substituent of the 2-indenyl system substituted in the 1,3-position, denote hydrogen, C1-C4-alkyl, C6-C14-aryl, C7-C10-aralkyl, C1-C4-alkoxy, C1-C4-alkylthio, phenoxy, phenylthio, di-C1-C4-alkylamino, C6-C14-aryl-C1-C4-alkylamino, di-C6-C14-arylamino, dibenzylamino, tri-C1-C4-alkylsilyl, di-C1-C4-alkylboranyl, phenyl-C1-C4-alkylboranyl, diphenylboranyl, di-C1-C4-alkylphosphoryl, diphenylphosphoryl or phenyl-C1-C4-alkylphos-phoryl,
- Q3 are identical or different and, as substituent of the 2-indenyl system substituted in the 4,5,6,7-position, denote hydrogen, C1-C4-alkyl, C6-C14-aryl, C7-C10-aralkyl, C1-C4-alkoxy, C1-C4-alkylthio, phenoxy, phenylthio, di-C1-C4-alkylamino, C6-C14-aryl-C1-C4-alkylamino, di-C6-C14-arylamino, dibenzylamino, tri-C1-C4-alkylsilyl, di-C1-C4-alkylboranyl, phenyl-C1-C4-alkylboranyl, diphenylboranyl, di-C1-C4-alkylphosphoryl, diphenylphosphoryl or phenyl-C1-C4-alkylphosphoryl,
- m is a number from zero to 4 that is determined by the number of the radicals Q3,
- Y is a bridge selected from the group consisting of —C(R1R2)—, —Si(R1R2)—, —Ge(R1R2)—, —C(R1R2)—C(R3R4)—, —C(R1R2)—Si(R3R4)— or —Si(R1R2)—Si(R3R4)—, wherein R1, R2, R3 and R4 independently of one another denote hydrogen, halogen, straight-chain or branched C1-C10-alkyl, C5-C8-cycloalkyl, C6-C14-aryl or C7-C10-aralkyl, and
- Hal3 denotes Cl, Br or I,
- comprising the step of reacting a 2-halogenated indene disubstituted in the 1,3-position of the formula
- in which
- Hal1 denotes Cl, Br or I,
- with an elementary metal selected from Groups I, II or XII of the Periodic System of the Elements according to IUPAC 1985 or a corresponding metal compound in an amount in the range from 1 to 100 moles of metal/metal compound per mole of (II) and with a dihalide of Y of the formula
- Hal2—Y—Hal3 (III),
- in which
- Hal2 and Hal3 independently of one another denote Cl, Br or I,
- in an amount of 1 to 20 moles of (III) per mole of (II), wherein in the case where Y denotes —Si(R1R2)—, —Ge(R1R2)— or —Si(R1R2)—Si(R3R4)—, the reaction of (II) with (i) elementary metal/metal compound and of (ii) with (III) may also take place simultaneously.
Catalysts for the polymerization of monomers selected from the group consisting of C2-C12-α-olefins, C4-C20-diolefins and cyclo(di)olefins or for the copolymerization of said monomers, said catalysts comprising organometallic compounds of transition metals with 2-indenyl as ligand substituted in the 1,3-position, that correspond to the general formula (I)
- wherein
- A denotes the benzo system or the tetrahydrocyclohexyl system,
- Q1, Q2 are identical or different and, as substituent of the 2-indenyl system substituted in the 1,3-position, denote hydrogen, C1-C4-alkyl, C6-C14-aryl, C7-C10-aralkyl, C1-C4-alkoxy, C1-C4-alkylthio, phenoxy, phenylthio, di-C1-C4-alkylamino, C6-C14-aryl-C1-C4-alkylamino, di-C6-C14-arylamino, dibenzylamino, tri-C1-C4-alkylsilyl, di-C1-C4-alkylboranyl, phenyl-C1-C4-alkylboranyl, diphenylboranyl, di-C1-C4-alkylphosphoryl, diphenylphosphoryl or phenyl-C1-C4-alkylphosphoryl,
- Q3 are identical or different and, as substituent of the 2-indenyl system substituted in the 4,5,6,7-position, denote hydrogen, C1-C4-alkyl, C6-C14-aryl, C7-C10-aralkyl, C1-C4-alkoxy, C1-C4-alkylthio, phenoxy, phenylthio, di-C1-C4-alkylamino, C6-C14-aryl-C1-C4-alkylamino, di-C6-C14-arylamino, dibenzylamino, tri-C1-C4-alkylsilyl, di-C1-C4-alkylboranyl, phenyl-C1-C4-alkylboranyl, diphenylboranyl, di-C1-C4-alkylphosphoryl, diphenylphosphoryl or phenyl-C1-C4-alkylphosphoryl,
- M1 is a transition metal from Group IV, V or VI of the Periodic System of the Elements according to IUPAC 1985,
- X denotes an anion,
- n is a number from zero to 4 that is determined by the valency and the bonding state of M1,
- m is a number from zero to 4 that is determined by the number of the radicals Q3,
- Y is a bridge selected from the group consisting of —C(R1R2)—, —Si(R1R2)—, —Ge(R1R2)—, —C(R1R2)—C(R3R4)—, —C(R1R2)—Si(R3R4)— or —Si(R1R2)—Si(R3R4)—, wherein R1, R2, R3 and R4 independently of one another denote hydrogen, halogen, straight-chain or branched C1-C10-alkyl, C5-C8-cycloalkyl, C6-C14-aryl or C7-C10-aralkyl, and
- Z is a second ligand from the group of open-chain and cyclic, optionally anionic π-systems, —N(R5)—, —P(R6)—, |N(R5R7)—, |P(R6R8)—, —O—, —S—, |OR5— or |SR5—, wherein the vertical lines to the left of the element symbol N, P, O and S denotes an electron pair, and the bonding between Z and M1 is ionic, covalent or co-ordinative, and wherein R5, R6, R7 and R8 independently of one another have the same range of meanings as R1 to R4, and R5 and R7 may in addition denote —Si(R1R2R3), and R6 and R8 may in addition denote —Si(R1R2R3), —OR1, —SR1 or —N(R1R2).
The production of amorphous, substantially atactic polymers comprising organometallic compounds of transition metals with 2-indenyl as ligand substituted in the 1,3-position, that correspond to the general formula (I)
- wherein
- A denotes the benzo system or the tetrahydrocyclohexyl system,
- Q1, Q2are identical or different and, as substituent of the 2-indenyl system substituted in the 1,3-position, denote hydrogen, C1-C4-alkyl, C6-C14-aryl, C7-C10-aralkyl, C1-C4-alkoxy, C1-C4-alkylthio, phenoxy, phenylthio, di-C1-C4-alkylamino, C6-C14-aryl-C1-C4-alkylamino, di-C6-C14-arylamino, dibenzylamino, tri-C1-C4-alkylsilyl, di-C1-C4-alkylboranyl, phenyl-C1-C4-alkylboranyl, diphenylboranyl, di-C1-C4-alkylphosphoryl, diphenylphosphoryl or phenyl-C1-C4-alkylphosphoryl,
- Q3 are identical or different and, as substituent of the 2-indenyl system substituted in the 4,5,6,7-position, denote hydrogen, C1-C4-alkyl, C6-C14-aryl, C7-C10-aralkyl, C1-C4-alkoxy, C1-C4-alkylthio, phenoxy, phenylthio, di-C1-C4-alkylamino, C6-C14-aryl-C1-C4-alkylamino, di-C6-C14-arylamino, dibenzylamino, tri-C1-C4-alkylsilyl, di-C1-C4-alkylboranyl, phenyl-C1-C4-alkylboranyl, diphenylboranyl, di-C1-C4-alkylphosphoryl, diphenylphosphoryl or phenyl-C1-C4-alkylphosphoryl,
- M1 is a transition metal from Group IV, V or VI of the Periodic System of the Elements according to IUPAC 1985,
- X denotes an anion,
- n is a number from zero to 4 that is determined by the valency and the bonding state of M1,
- m is a number from zero to 4 that is determined by the number of the radicals Q3,
- Y is a bridge selected from the group consisting of —C(R1R2)—, —Si(R1R2)—, —Ge(R1R2)—, —C(R1R2)—C(R3R4)—, —C(R1R2)—Si(R3R4)— or —Si(R1R2)—Si(R3R4)—, wherein R1, R2, R3 and R4 independently of one another denote hydrogen, halogen, straight-chain or branched C1-C10-alkyl, C5-C8-cycloalkyl, C6-C14-aryl or C7-C10-aralkyl, and
- Z is a second ligand from the group of open-chain and cyclic, optionally anionic π-systems, —N(R5)—, —P(R6)—, |N(R5R7)—, |P(R6R8)—, —O—, —S—, |OR5— or |SR5—, wherein the vertical lines to the left of the element symbol N, P, O and S denotes an electron pair, and the bonding between Z and M1 is ionic, covalent or co-ordinative, and wherein R5, R6, R7 and R8 independently of one another have the same range of meanings as R1 to R4, and R5 and R7 may in addition denote —Si(R1R2R3), and R6 and R8 may in addition denote —Si(R1R2R3), —OR1, —SR1 or —N(R1R2).
The production of EP(D)M comprising organometallic compounds of transition metals with 2-indenyl as ligand substituted in the 1,3-position, that correspond to the general formula (I)
- wherein
- A denotes the benzo system or the tetrahydrocyclohexyl system,
- Q1, Q2 are identical or different and, as substituent of the 2-indenyl system substituted in the 1,3-position, denote hydrogen, C1-C4-alkyl, C6-C14-aryl, C7-C10-aralkyl, C1-C4-alkoxy, C1-C4-alkylthio, phenoxy, phenylthio, di-C1-C4-alkylamino, C6-C14-aryl-C1-C4-alkylamino, di-C6-C14-arylamino, dibenzylamino, tri-C1-C4-alkylsilyl, di-C1-C4-alkylboranyl, phenyl-C1-C4-alkylboranyl, diphenylboranyl, di-C1-C4-alkylphosphoryl, diphenylphosphoryl or phenyl-C1-C4-alkylphosphoryl,
- Q3 are identical or different and, as substituent of the 2-indenyl system substituted in the 4,5,6,7-position, denote hydrogen, C1-C4-alkyl, C6-C14-aryl, C7-C10-aralkyl, C1-C4-alkoxy, C1-C4-alkylthio, phenoxy, phenylthio, di-C1-C4-alkylamino, C6-C14-aryl-C1-C4-alkylamino, di-C6-C14-arylamino, dibenzylamino, tri-C1-C4-alkylsilyl, di-C1-C4-alkylboranyl, phenyl-C1-C4-alkylboranyl, diphenylboranyl, di-C1-C4-alkylphosphoryl, diphenylphosphoryl or phenyl-C1-C4-alkylphosphoryl,
- M1 is a transition metal from Group IV, V or VI of the Periodic System of the Elements according to IUPAC 1985,
- X denotes an anion,
- n is a number from zero to 4 that is determined by the valency and the bonding state of M1,
- m is a number from zero to 4 that is determined by the number of the radicals Q3,
- Y is a bridge selected from the group consisting of —C(R1R2)—, —Si(R1R2)—, —Ge(R1R2)—, —C(R1R2)—C(R3R4)—, —C(R1R2)—Si(R3R4)— or —Si(R1R2)—Si(R3R4)—, wherein R1, R2, R3 and R4 independently of one another denote hydrogen, halogen, straight-chain or branched C1-C10-alkyl, C5-C8-cycloalkyl, C6-C14-aryl or C7-C10-aralkyl, and
- Z is a second ligand from the group of open-chain and cyclic, optionally anionic π-systems, —N(R5)—, —P(R6)—, |N(R5R7)—, |P(R6R8)—, —O—, —S—, |OR5— or |SR5—, wherein the vertical lines to the left of the element symbol N, P, O and S denotes an electron pair, and the bonding between Z and M1 is ionic, covalent or co-ordinative, and wherein R5, R6, R7 and R8 independently of one another have the same range of meanings as R1 to R4, and R5 and R7 may in addition denote —Si(R1R2R3), and R6 and R8 may in addition denote —Si(R1R2R3), —OR1, —SR1 or —N(R1R2).
The production of atactic polypropylene comprising organometallic compounds of transition metals with 2-indenyl as ligand substituted in the 1,3-position, that correspond to the general formula (I)
- wherein
- A denotes the benzo system or the tetrahydrocyclohexyl system,
- Q1, Q2 are identical or different and, as substituent of the 2-indenyl system substituted in the 1,3-position, denote hydrogen, C1-C4-alkyl, C6-C14-aryl, C7-C10-aralkyl, C1-C4-alkoxy, C1-C4-alkylthio, phenoxy, phenylthio, di-C1-C4-alkylamino, C6-C14-aryl-C1-C4-alkylamino, di-C6-C14-arylamino, dibenzylamino, tri-C1-C4-alkylsilyl, di-C1-C4-alkylboranyl, phenyl-C1-C4-alkylboranyl, diphenylboranyl, di-C1-C4-alkylphosphoryl, diphenylphosphoryl or phenyl-C1-C4-alkylphosphoryl,
- Q3 are identical or different and, as substituent of the 2-indenyl system substituted in the 4,5,6,7-position, denote hydrogen, C1-C4-alkyl, C6-C14-aryl, C7-C10-aralkyl, C1-C4-alkoxy, C1-C4-alkylthio, phenoxy, phenylthio, di-C1-C4-alkylamino, C6-C14-aryl-C1-C4-alkylamino, di-C6-C14-arylamino, dibenzylamino, tri-C1-C4-alkylsilyl, di-C1-C4-alkylboranyl, phenyl-C1-C4-alkylboranyl, diphenylboranyl, di-C1-C4-alkylphosphoryl, diphenylphosphoryl or phenyl-C1-C4-alkylphosphoryl,
- M1 is a transition metal from Group IV, V or VI of the Periodic System of the Elements according to IUPAC 1985,
- X denotes an anion,
- n is a number from zero to 4 that is determined by the valency and the bonding state of M1,
- m is a number from zero to 4 that is determined by the number of the radicals Q3,
- Y is a bridge selected from the group consisting of —C(R1R2)—, —Si(R1R2)—, —Ge(R1R2)—, —C(R1R2)—C(R3R4)—, —C(R1R2)—Si(R3R4)— or —Si(R1R2)—Si(R3R4)—, wherein R1, R2, R3 and R4 independently of one another denote hydrogen, halogen, straight-chain or branched C1-C10-alkyl, C5-C8-cycloalkyl, C6-C14-aryl or C7-C10-aralkyl, and
- Z is a second ligand from the group of open-chain and cyclic, optionally anionic π-systems, —N(R5)—, —P(R6)—, |N(R5R7)—, |P(R6R8)—, —O—, —S—, |OR5— or |SR5—, wherein the vertical lines to the left of the element symbol N, P, O and S denotes an electron pair, and the bonding between Z and M1 is ionic, covalent or co-ordinative, and wherein R5, R6, R7 and R8 independently of one another have the same range of meanings as R1 to R4, and R5 and R7 may in addition denote —Si(R1R2R3), and R6 and R8 may in addition denote —Si(R1R2R3), —OR1, —SR1 or —N(R1R2).
Dependencies are inferred from the claim text.