Abstract: A metallocene compound having the general formula: CpAXMQ1Q2Cp′A′X′M′Q1′Q2′ wherein Cp and Cp′ are each independently a substituted or unsubstituted cyclopentadienyl moiety; M and M′ are each independently a metal chosen from Group IV B transition metals and vanadium, and coordinate to Cp and Cp′ respectively; X and X′ are each independently a substituted or unsubstituted Group VA or VIA heteroatom and coordinate to M and M″ respectively; A and A′ are bridging groups between Cp and X and between Cp′ and X′ respectively and are independently chosen from —SiR′2—O—SiR′2—, —SinR′m—, —CnR′m— and —CR′2—SiR′2—CR′2—SiR′2—, in which each R′ is independently H or hydrocarbyl having 1 to 20 carbon atoms, n is an integer in the range 1 to 4 and m=2n; each Q1, Q2 and Q1′ and Q2′ is independe

Abstract: There are disclosed new metallocene compounds and catalysts for olefin polymerization. The metallocene compound is a complex of transition metal and cyclopentadienyl-type ligands substituted with silacycloalkyl group. The metallocene catalyst comprises the above metallocene compound and at least one activator such as aluminoxanes, aromatic boron compounds substituted with fluoride, and modified clays. The metallocene catalyst can be used for polymerization of olefin in liquid phase, slurry phase or gas phase process.

Abstract: A metallocene compound having the general formula: CpAXMQ1Q2Cp′A′X′M′Q1′Q2′ wherein Cp and Cp′ are each independently a substituted or unsubstituted cyclopentadienyl moiety; M and M′ are each independently a metal chosen from Group IV B transition metals and vanadium, and coordinate to Cp and Cp′ respectively; X and X′ are each independently a substituted or unsubstituted Group VA or VIA heteroatom and coordinate to M and M′ respectively; A and A′ are bridging groups between Cp and X and between Cp′ and X′ respectively and are independently chosen from —SiR′2—O—SiR′2—, —SinR′m—, —CnR′m— and —CR′2—SiR′2—CR′2—SiR′2—, in which each R′ is independently H or hydrocarbyl having 1 to 20 carbon atoms, n is an integer in the range 1 to 4 and m=2n; each Q1, Q2 and Q1′ and Q2′ is independe

Abstract: A process for preparing a half-vanadocene compound, the process comprising reacting chlorine gas with a vanadocene compound represented by the formula (1)

Abstract: This invention is directed to novel catalysts the structure and activity of which can be controlled to produce a wide range of alpha olefin polymers and co-polymers, and preferably for the production of stereoblock poly alpha olefins comprising a wide range of preselected amorphous and crystalline segments for precise control of the physical properties thereof, principally elastomeric thermoplastic properties. More specifically, this invention is directed to novel catalysts and catalysts systems for producing stereoblock polypropylene comprising alternating isotactic and atactic diastereosequences, which result in a wide range of elastomeric properties. The amount and numbers of crystalline sections, the isotactic pentad content, the number and length of intermediate atactic chains and overall molecular weight are all controllable by the steric structure of the catalysts and the process conditions.

Abstract: Metallocene having two cyclic dienyl groups connected by a single carbon having an aryl substituent and a terminally unsaturated hydrocarbyl substituent, olefin polymerization catalyst systems prepared therefrom, and the use of such catalyst systems are disclosed.

Abstract: Provided is a metallocene catalyst component for use if preparing isotactic polyolefins, which component has the general formula (I): R″ (CpR1R2R3)(Cp′R′n) MQ2 wherein Cp is a substituted cyclopentadienyl ring; Cp′ is substituted or unsubstituted fluorenyl ring; R″ is a structural bridge imparting stereorigidity to the component; R1 is a substituent on the cyclopentadienyl ring which is distal to the bridge, which distal substituent comprises a bulky group of the formula XR*3 in which X is chosen from Group IVA, and each R* is the same or different and chosen from hydrogen or hydrocarbyl of from 1 to 20 carbon atoms, R2 is substituent on the cyclopentadienyl ring which is proximal to the bridge and positioned non-vincinal to the distal substituent, and is of the formula YR#3, in which Y is chosen from Group IVA, and each R# is the same or different and chosen from hydrogen or hydrocarbyl of 1 to 7 carbon atoms, R3 is a substituent on the cyclopentadienyl ring which is pro

Abstract: This invention relates to metallocene compositions and their use in the preparation of catalyst systems for olefin polymerization, particularly propylene polymerization.

Abstract: Metal complexes having constrained geometry and a process for preparation thereof, addition polymerization catalysts formed therefrom, processes for preparation of such addition polymerization catalysts, methods of use, and novel polymers formed thereby, including ElPE resins and pseudo-random copolymers, are disclosed and claimed.

Abstract: A process for producing high-purity hydrotalcites by reacting alcohols or alcohol mixtures with at least one or more divalent metal(s) and at least one or more trivalent metal(s) and hydrolyzing the resultant alcoholate mixture with water. The corresponding metal oxides can be produced by calcination.

Abstract: The present invention relates to catalyst systems, processes for making such catalysts, intermediates for such catalysts, and olefin polymerization processes using such catalysts wherein such catalyst includes a component represented by the following formula 1A: wherein R and R′ independently represent a hydrogen atom, or a substituted or unsubstituted, branched or unbranched hydrocarbyl or organosilyl radical; R1, R2, and R3 independently represent a hydrogen atom, or a substituted or unsubstituted, branched or unbranched hydrocarbyl radical; M is a group IIIB, IVB, VB, VIB, VIIB or VIII transition metal; T independently represents a univalent anionic ligand such as a hydrogen atom, or a substituted or unsubstituted hydrocarbyl halogeno, aryloxido, arylorganosilyl, alkyloriganosilyl, amido, arylamido, phosphido, or arylphosphido group, or two T groups taken together represent an alkylidene or a cyclometallated hydrocarbyl bidentate ligand; L independently represents a sigma donor

Abstract: Metallocenes having a 9-fluorenyl group and another cyclic dienyl group connected by a single carbon having a terminally unsaturated hydrocarbyl substituent wherein the 9-fluorenyl group has a hydrocarbyl substituent in the 4 position, olefin polymerization catalyst systems prepared therefrom, and the use of such catalyst systems are disclosed.

Abstract: The invention provides metallocene catalyst systems for the controlled polymerization of alkenes to a wide variety of polyolefins and olefin coplymers. Catalyst systems are provided that specifically produce isotactic, syndiotactic and steroblock polyolefins. The type of polymer produced can be controlled by varying the catalyst system, specifically by varying the ligand substituents. Such catalyst systems are particularly useful for the polymerization of polypropylene to give elastomeric polypropylenes. The invention also provides novel elastomeric polypropylene polymers characterized by dyad (m) tacticities of about 55% to about 65%, pentad (mmmm) tacticities of about 25% to about 35%, molecular weights (Mw)in the range of about 50,000 to about 2,000,000, and have mmrm+rrmr peak is less than about 5%.

Abstract: The invention is a polymerization catalyst system derived from tethered, heteroatom-bridged monocyclopentadienyl transition metal compound precursor from Group 4 of the Periodic Table of the Elements. The catalyst system comprises an activated, tethered pair of Group 4 transition metal compounds having a bidentate ancillary ligand system consisting of one cyclopentadienyl group bound to the transition metal and a Group 15 or Group 16 atom covalently bound to the transition metal and linked to the cyclopentadienyl group through a bridging group containing a Group 14-15 element. The ligand systems of each transition metal compound are tethered by at least one tethering group comprising a Group 13-16 element connected at both ends to either the Group 15 or Group 16 atom or the Groups 14-15 bridging group element. The catalyst system can be employed to polymerize olefins to produce a high molecular weight polymer.

Abstract: A class of metallocene compounds is disclosed having the general formula (I): wherein Y is a moiety of formula (II) wherein A, B and D, same or different from each other, are selected from an element of the groups 14 to 16 of the Periodic Table of the Elements (new IUPAC version), with the exclusion of nitrogen and oxygen; R1, R2, R3, R4 and R5 are hydrogen or hydrocarbon groups, Z is selected from a moiety of formula (II) as described above and from a moiety of formula (III): wherein R6, R7, R8 and R9, are hydrogen or hydrocarbon groups; L is a divalent bridging group; M is an atom of a transition metal selected from those belonging to group 3, 4, 5, 6 or to the lanthanide or actinide groups in the Periodic Table of the Elements (new IUPAC version), X, same or different, is hydrogen, a halogen, a R10, OR10, OSO2CF3, OCOR10, SR10, NR102 or PR102 group, wherein the substituents R10 are hydrogen or alkyl groups; p is an integer of from 0 to 3, being equal to

Abstract: Metallocene compounds having the general formula (I): R1 are hydrocarbon groups, R2 are hydrogen or hydrocarbon groups; M is a transition metal of group 3, 4, 5, 6 or to the lanthanide or actinide groups in the Periodic Table; M′ is a transition metal selected from those belonging to group 3 or to the lanthanide or actinide groups in the Periodic Table; X is a monoanionic ligand; p is an integer of from 0 to 3, being equal to the oxidation state of M minus two; q is an integer from 3 to 5; and n is an integer from 1 to 4, when the six-membered rings of formula (Ia) are not perhydrated, and is an integer of from 0 to 4, when the six-membered rings of formula (Ia) are perhydrated as well as in the compound of formula (Ib).

Abstract: Bridged and unbridged fluorenyl-containing metallocenes of the formula R″x(FlRn)(CpRm)MQk wherein Fl is a fluorenyl radical, Cp is a cyclopentadienyl, indenyl, tetrahydroindenyl, or fluorenyl radical, each R is an organo radical, R″ is a structural bridge linking (FlRn) and (CpRm), M is a metal selected from the group consisting of IVB, VB, and VIB metals, each Q is selected from the group consisting of hydrocarbyl or hydrocarbyloxy radicals and halogen, x is 1 or 0, k is an integer sufficient to fill out the remaining valences of M, n is in the range of 0 to 7, and m is 0 to 7, further characterized by the fact that if (CpRm) is unsubstituted fluorenyl and metallocene is an unbridged metallocene, then n is 1 to 7 and if R″ is 1,1-dimethylmethylene and (CpRm) is unsubstituted cyclopentadienyl or 3-methylcyclopentadienyl, then n is 1 to 7.

Abstract: Stabilized alumoxane solutions are provided as well as a method for producing such solutions. The method generally involves the use of metallocene catalyst component(s) that when mixed with alumoxane solutions reduce the tendency for such solutions to form gels.

Abstract: A metallocene compound having the general formula: CpAXMQ1Q2Cp′A′X′M′Q1′Q2′ wherein Cp and Cp′ are each independently a substituted or unsubstituted cyclopentadienyl moiety; M and M′ are each independently a metal chosen from Group IV B transition metals and vanadium, and coordinate to Cp and Cp′ respectively; X and X′ are each independently a substituted or unsubstituted Group VA or VIA heteroatom and coordinate to M and M′ respectively; A and A′ are bridging groups between Cp and X and between Cp′ and X′ respectively and are independently chosen from —SiR′2—O—SiR′2—, —SinR′m—, —CnR′m— and —CR′2—SiR′2—CR′2—SiR′2—, in which each R′ is independently H or hydrocarbyl having 1 to 20 carbon atoms, n is an integer in the range 1 to 4 and m=2n; each Q1, Q2 and Q1′ and Q2′ is independe

Abstract: New metallocene compounds are described where the ligand contains at least one open-pentadienyl containing radical characterized by a cyclic or acyclic, six &pgr; electron, delocalized, five atomic center structure. These metallocenes can advantageously be used in catalyst systems for the polymerization of olefins to generate a wide variety of different polymers including HDPE, LLDPE, ethylenelpropylene/(diene) elastomers, tactiospecific C3+&agr;-olefin polymers, intimate mixture thereof and the like.

Abstract: A single-site olefin polymerization catalyst and method of making it are disclosed. The catalyst comprises an activator and an organometallic complex. The complex comprises a Group 3 to 10 transition or lanthanide metal, M, and at least one indenoindolyl ligand that is &pgr;-bonded to M. The key ligand is made in two steps from readily available indanones and aryl hydrazines. Reaction of its anion with a source of the metal completes a remarkably simple synthetic route to a new family of single-site olefin polymerization catalysts.

Abstract: A method is provided for synthesizing metallocene compounds useful as polymerization catalysts and the like. The method involves (a) preparation of an amino alcohol-derived ligand by reacting a silane reactant with an amino alcohol in the presence of base, followed by (b) metallation of the ligand so provided. The metallocenes may be provided in chiral form when the amino alcohol contains an asymmetric center, and are thus useful in catalyzing stereospecific polymerization and other stereospecific bond formation reactions.

Abstract: Metallocene compounds with two indenyl-type ligands linked in the 4 position by means of a divalent bridging group can be suitably used as components of catalysts for the polymerization of olefins. In particular, it is possible to prepare saturated or unsaturated elastomeric copolymers of ethylene characterized by valuable properties, such as low ash content and uniform distribution of the comonomers in the polymer chain.

Abstract: The invention relates to metallocen compounds having &eegr;5 ligands comprising at least four fused rings and having a sum of fused rings in all of its &eegr;5 ligands being at least 6. Such compounds are for example {[1-(7,9-diphenylcyclopent[a]acenaphthadienyle)-1-phenyle-2-(7,9-diphenylcyclopent[a]acenaphthadienyl)]ethane} zirconium dichloride, {[1-(7,9-diphenycyclopent[a]acenaphthadienyl)-1-phenyl-2-flourenyl]ethane} zirconium dichloride, [bis(7,9-diphenylcyclopent[a]acenaphthadienyl)] zirconium dichloride and [bis(7,9-diphenylcyclopent[a]acenaphthadienyl)]hafnium dichloride. The invention also relates to a catalyst composition comprising such as an aluminoxane. The metallocene compound and the catalyst composition can successfully be used to produce high molecular weight polyethene and long-chain branch polypropene.

Abstract: The present invention relates to a catalyst for polymerization of &agr;-olefin, which comprises: an essential component (A) of a transition metal compound, an essential component (B) of an ion exchangeable layer compound except for silicate, or an inorganic silicate, and an optional component (C) of an organoaluminum compound, said component (A) being represented by the general formula (I):

Abstract: Indenyl compound of formula (1) wherein: M is a transition metal from the lanthanides or from group 3, 4, 5 or 6 of the Periodic System of Elements, Q is an anionic ligand to M, k is the number of Q groups, R is a bridging group and Z and X are substituents, wherein R contains at least one sp2-hybridized carbon atom that is bonded to the indenyl group at the 2-position with the exclusion of Ti(deshydronorbiphenacene) dichloride.

Abstract: The invention relates to a process for the preparation of polyolefins by polymerizing olefins of the formula CH2CHR in which R=H or C1-C10 alkyl, on their own or as a mixture, if appropriate together with C4-C12 &agr;,&ohgr;-diolefins, in solvents, liquid monomers or the gas phase, at temperatures between −50° and 200° C.

Abstract: The invention relates to novel targeting drug agents that are targeted for entry into the mitochondria. More specifically, the agents are cisplatin derivatives called mitoplatins which are useful as anti-tumor agents. Mitoplatins are named for their targeting to the mitochondrial DNA via the carnitine-acylcarnitine translocase system. The invention also relates to methods of synthesizing mitoplatins, compositions of matter containing mitoplatins and methods of using the mitoplatins.

Abstract: A cationic catalyst composition comprising a reactive cation and a compatible non-coordinating anion is preferably used at a temperature of 20° C. or less to produce olefin polymers, particularly polymers and copolymers of isobutylene.

Abstract: Metallocenes containing aryl-substituted indenyl derivatives as ligands, process for their preparation, and their use as catalysts.

Abstract: It is disclosed a new class of bridged metallocene compounds of formula (I): wherein R1 and R2 can be hydrogen, alkyl, cycloalkyl, aryl, alkylaryl or arylalkyl radicals; R3 and R4 form a condensed, 5- to 8-membered, aliphatic, aromatic or heterocyclic ring; M is a transition metal of groups 3, 4, 5, lanthanide or actinide; X is hydrogen, halogen, —R, —OR, —OSO2CF3, —OCOR, —SR, —NR2 or PR2, wherein R is an hydrocarbon substituent; and p is 0-3. Furthermore, a catalyst system for olefin polymerization based on the above bridged metallocene compounds and the ligands for their preparation are disclosed.

Abstract: The present invention relates to a metallocene compound containing at least two metallocene fragments L—MX2—L which are different from one another and having the formula I where B is a bridging unit, m is an integer from 2 to 100,000, M is a metal atom of group IVb, Vb or VIb of the Periodic Table of the Elements, X are identical or different in one metallocene fragment L—MX2—L and are each, independently of one another, hydrogen, a C1-C40-hydrocarbon-containing group, an OH group, a halogen atom or a pseudohalogen, L are identical or different in one metallocene fragment and are each, independently of one another, a &pgr; ligand or another electron donor. The metallocene compound can advantageously be used as a catalyst component for olefin polymerization.

Abstract: The (polyfluoroaryl)fluoroanions of aluminum, gallium, and indium are novel weakly coordinating anions which are are highly fluorinated. (Polyfluoroaryl)fluoroanions of one such type contain at least one ring substituent other than fluorine. These (polyfluoroaryl)fluoroanions of aluminum, gallium, and indium have greater solubility in organic solvents, or have a coordinative ability essentially equal to or less than that of the corresponding (polyfluoroaryl)fluoroanion of aluminum, gallium, or indium in which the substituent is replaced by fluorine. Another type of new (polyfluoroaryl)fluoroanion of aluminum, gallium, and indium have 1-3 perfluorinated fused ring groups and 2-0 perfluorophenyl groups.

Abstract: Racemic metallocene complexes are prepared by reacting bridged or unbridged transition metal complexes with cyclopentadienyl derivatives of alkali metals or alkaline earth metals and, if desired, subsequently replacing the aromatic ligands.

Abstract: A very effective catalyst system for the polymerization or copolymerization of olefins comprises a cocatalyst, preferably an aluminoxane or a supported aluminoxane, and a metallocene of the formula I in which, in the preferred form, M1 is Zr or Hf, R1 and R2 are halogen or alkyl, R3 is alkyl, R4 to R12 are alkyl or hydrogen and R13 is a (substituted) alkylene or heteroatom bridge. The metallocenes, in particular the zirconocenes, produce polymers of a very high molecular weight, in the case of prochiral monomers polymers of a very high molecular weight, very high stereoactivity and very high melting point, at high catalyst activities in the industrially particularly interesting temperature range between 50 and 80° C. In addition, reactor deposits are avoided by means of supported catalyst systems.

Abstract: The present invention relates to a process for preparing a methylene-bridged biscyclopentadienyl compound having the formula I where L are, independently of one another, identical or different and are each a cyclopentadienyl group, by reacting one or two cyclopentadienyl compounds LH with formaldehyde in monomeric, oligomeric or polymeric form or formaldehyde-generating reagents in the presence of at least one base and at least one phase transfer catalyst.

Abstract: Chiral metallocenes are prepared by reacting a salt of an asymmetric bis(cyclopentadienyl)-moiety-containing ligand with a tertiary heteroaromiatic amine adduct of a transition, lanthanide, or actinide metal halide in an organic solvent or diluent so as to produce said chiral metallocene.

Abstract: The present invention relates to a catalyst for polymerization of &agr;-olefin, which comprises: an essential component (A) of a transition metal compound, an essential component (B) of an ion exchangeable layer compound except for silicate, or an inorganic silicate, and an optional component (C) of an organoaluminum compound, said component (A) being represented by the general formula (I):

Abstract: Organometallic compounds of transition metals containing optionally tetrahydrogenated 2-indenyl as a first ligand of the formula wherein A represents the benzo system or the tetrahydrocyclohexyl system and the other symbols have the range of meanings given in the description, are prepared by reaction of with Mg or Zn and with a dihalide Hal2—Y—Hal3 (III) to form the novel intermediates further reaction with ZM2p(Va) or ZR9p(Vb) to form and further reaction with a transition metal compound of the formula M1Xq(VIII). Many compounds (I) are not C2-symmetrical. The compounds (I) can be used as catalysts for the (co)polymerization of olefins, diolefins and/or cycloolefins.

Abstract: The invention relates to metallocenes of formula (I), in which M is a metal from the Ti, Zr, Hf, V, Nb, Ta group or an element from the lanthanide group, X1 and X2 stand for an alkyl-, aryl-, alkenyl-, arylalkyl-, alkylaryl- or arylalkenyl group and L1 and L2 are hydrocarbon capable of forming a sandwich structure with M. R stands for C, Si, Ge or Sn, A and B are ferrocenyl-substituted radicals, or B is optionally a radical X1 of X2. The metallocenes are preferably used as catalysts in the polymerization of olefins.

Abstract: Group 3-6 or Lanthanide metal complexes possessing two metal centers joined by means of a divalent bridging group joining trivalent moieties comprising boron or a member of Group 14 of the Periodic Table of the Elements, and optionally also comprising nitrogen, phosphorus, sulfur or oxygen, in the complexes, catalysts derived therefrom by combining the same with strong Lewis acids, Bronsted acid salts, salts containing a cationic oxidizing agent or subjected to bulk electrolysis in the presence of compatible, inert non-coordinating anions and the use of such catalysts for polymerizing olefins, diolefins and/or acetylenically unsaturated monomers are disclosed.

Abstract: Novel heterogeneous catalysts for the which hydrogenation of olefins and arenes with high conversion rates under ambient conditions and the polymerization of olefins have been developed. The catalysts are synthesized from Ziegler-type precatalysts by supporting them on sulfate-modified zirconia.

Abstract: Syndio-isoblock polymers of 1-olefins having molecular chains which contain syndiotactic and isotactic sequences are obtained if the polymerization of the 1-olefins is carried out using a catalyst which is composed of a bridge chiral metallocene of the formula I an an aluminoxane. The polymers have some rubber-like properties.

Abstract: A new process is disclosed, particularly simple, convenient and practical, for the direct synthesis of metallocenes of formula (I): (CP)(ZR1m)n(A)rMLpL′q wherein (ZR1m)n is a divalent group bridging Cp and A; Cp is a substituted or unsubstituted cyclopentadieryl group; A is —O—, —S—, —N(R2)—, wherein R2 is hydrogen, alkyl, cycloalkyl aryl, alkylaryl or arylalkyl, or A has the same meaning of Cp; M is a transition metal belonging to group 3, 4, 5, 6 or to the lanthanide or actinide groups; L is a monoanionic sigma ligand, such as alkyl, cycloalkyl, aryl, alkylaryl or arylalkyl, optionally containing Si or Ge; L′ is halogen or —OR5, R5 being a hydrocarbon radical; m is 1 or 2; n is 0-4; r is 0 or 1; p is 1-3; q is 0-2.

Abstract: Isospecific and/or syndiospecific catalysts and processes for the propagation of an isotactic and/or syndiotactic polymer chain derived from an ethylenically unsaturated monomer which contains 3 or more carbon atoms or is a substituted vinyl compound. The catalysts comprise a stereorigid, stereodirected and stereolocked metallocene and/or metallocene cation catalysts, characterized by having &bgr; stereodirecting substituents and &agr; stereolocking substituents such that the catalysts have overall either Cs or C2 (or pseudo-Cs or C2) symmetry and such that the substituents define the orientation of the growing polymer chain end and resulting in tactioselectivity of successive monomer additions. Methods are also described for the preparation and use of these unique catalysts.

Abstract: Stabilized alumoxane solutions are provided as well as a method for producing such solutions. The method generally involves the use of metallocene catalyst component(s) that when mixed with alumoxane solutions reduce the tendency for such solutions to form gels.

Abstract: A novel multiply crosslinked transition metal compound represented by the formula (I): wherein M is a metallic element of the Groups 3 to 10 or the lanthanide series of the Periodic Table; E1 and E2 are each a &sgr;-bonding or &pgr;-bonding ligand; X is a &sgr;-bonding ligand; Y is a Lewis base; A1, A2, . . . An and D are each a crosslinking group, and at least one of A1, A2, . . . An comprises a crosslink consisting of carbon alone; n is 2 to 4; p is 1 to 4; q is 1 to 5 and equal to the valence of M minus 2; r is 0 to 3; and s is 0 to 4, and a production process thereof. The transition metal compound is useful as a component of a polymerization catalyst for catalyzing the production of an olefin polymer having a uniform composition and a narrow molecular weight distribution in a high yield.

Abstract: The novel metallocenes of the formula I in which, preferably, M1 is Zr or Hf, R1 and R2 are alkyl or halogen, R3 and R4 are hydrogen, R5 and R6 are alkyl or haloalkyl, —(CR8R9)m—R7—(CR8R9)n— is a single- or multi-membered chain in which R7 may also be a (substituted) hetero atom, m+n is zero or 1, and R10 is hydrogen, form, together with aluminoxanes as cocatalysts, a very effective catalyst system for the preparation of polyolefins or high stereospecificity and high melting point. Polyolefins with unique or improved properties are obtained by polymerizing an olefin in the presence of a metallocene combined with a cocatalyst, wherein the metallocene is preferably a zirconocene or a hafnocene, and the Zr or Hf central atom is coordinated with two ligands which are derivatives of 2-substituted indenyl nuclei and which are substituted with at least one and up to four groups (e.g. aliphatic or aromatic groups) on the six-member rings of the indenyl nuclei.

Abstract: The novel metallocenes of the formula I in which, preferably, M1 is Zr or Hf, R1 and R2 are alkyl or halogen, R3 and R4 are hydrogen, R5 and R6 are alkyl or haloalkyl, —(CR8R9)m—R7—(CR8R9)n— is a single- or multi-membered chain in which R7 may also be a (substituted) hetero atom, and m+n is zero or 1, form, together with aluminoxanes as cocatalysts, a very effective catalyst system for the preparation of polyolefins of high molecular weight.

Abstract: Process for the preparation of an olefin polymer using metallocenes containing specifically substituted indenyl ligands A highly effective catalyst system for the polymerization of olefins comprises a cocatalyst, preferably an aluminoxane, and a metallocene of the formula I in which, preferably M1 is Zr or Hf, R1 and R2 are alkyl or halogen, R5 is hydrogen or alkyl, R3 and R4 are alkyl, where R3, R4 and R5 may be halogenated, —(CR7R8)m—R6—(CR7R8)n— is a single- or multi-membered chain in which R6 may also be a (substituted) heteroatom, and m+n is zero or 1.