Abstract: The invention is a catalyst system including a monocyclopentadienyl titanium compound, where the monocyclopentadienyl group is bonded to a silylene-imido moiety which is further bonded to the titanium atom, and an alumoxane component which is highly productive for polymerizing ethylene and &agr;-olefins to produce a high molecular weight ethylene-&agr;-olefin copolymer having a high content of &agr;-olefin.

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: Substituted metallocenes which have a substituent selected from the group consisting of aryl alkyl, aryl alkyl silyl, and aryl silyl groups, catalyst systems resulting from the combination of such metallocenes and a cocatalyst, and for producing olefins using such catalyst systems.

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: 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 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: 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: 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: A specified transition metal compound having two transition metals and two cyclopentadiene type anion skeletone in tis molecule and said metals are linked through an atom of Group XVI of the Periodic Table of the Elements, and olefin polymerization catalyst component comprising said transition metal compound, an olefin polymerization catalyst comprising said transition metal compound, a specific organoaluminum compound, and a specific boron compound, and a process for producing an olefin polymer using said olefin polymerization catalyst.

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: Zirconocene compounds with two indenyl ligands linked in the 2 position by means of a two-carbon-atoms divalent bridging group can be suitably used as components of catalysts for the polymerization of olefins. Particularly it is possible to prepare, with high yields, ethylene (co)polymers having low molecular weights and narrow molecular weight distributions, without the need of using considerable amounts of molecular weight regulators, such as hydrogen.

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 method for the preparation of titanium-containing metallocene compounds, including constrained geometry titanium complexes, useful as olefin polymerization catalysts is disclosed. Pursuant to the invention, titanium tetrachloride is converted to titanium trichloride by reaction with a metal compound in a non-interfering solvent to produce a mixture useful directly for reaction with a deprotonated metallocene ligand. The titanocene compounds produced pursuant to the invention are free of trace amounts of aluminum which can adversely affect the polymerization reaction.

Abstract: Disclosed are a novel transition metal compound represented by the following general formula (I), a catalyst component for olefin polymerization comprising same, a catalyst for olefin polymerization comprising said catalyst component, and a process for the preparation of an &agr;-olefin polymer: where the definition of formula (I) is described in the specification.

Abstract: A class of bridged or unbridged metallocene compounds is disclosed, wherein the cyclopentadienyl ligands have two or four adjacent substituents forming one or two alkylenic cycles of from 4 to 8 carbon atoms. These metallocenes are useful as catalyst components for the polymerization of olefins, particularly for the (co)polymerization of ethylene and for the polymerization of propylene.

Abstract: A metallocene complex in which the cyclopentadienyl group is substituted with an alkanediyl silyl group. The yield of the metallocene complex is high, and it can be used as the catalyst for preparing high molecular weight olefin polymers.

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: Disclosed is a process for the preparation of metallocone complexes wherein stereoisomers of metallocene complexes formed at the time of synthesis can easily be separated. The gist of the present invention resides in separation of a part of an isomeric mixture of specific metallocene complexes bridged with a transition metal represented by the formula (1) as a complex having M—O bond. In particular, preferable is a process for separating a part of an isomeric mixture of a metallocene complex represented by the formula (2) as a &mgr;-oxo-complex represented by the formula (3).

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: 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: Chemically homogeneous cycloolefin copolymers of polycyclic olefins, such as, for example, norbornene or tetracyclododecene, with cycloolefins and/or acyclic olefins are obtained without ring opening and in a high space-time yield if a catalyst system is used which comprises an aluminoxane and a stereorigid metallocene compound of an element from groups IVb to VIb, of the formula the part of the metallocene molecule formed by M1 and the substituents R16-R17 having C1-symmetry or being in the meso-form.

Abstract: A metallocene compound is provided wherein to a transition metal compound is bonded a multidentate compound wherein a substituted cycloalkadienyl ring CA1 having therein a heteroaromatic group Ra containing an oxygen, sulfur or nitrogen atom on a cycloalkadienyl ring, preferably the five-membered ring thereof, and an unsubstituted or substituted cycloalkadienyl group CA2 or —(R1)N—, —O—, —S— or —(R1)P—, preferably CA2, more preferably a substituted cycloalkadienyl group identical with CA1 are bonded through a divalent linking group. The metallocene compound is suitable as a principal ingredient of a catalyst for the polymerization of olefins, particularly achieving a very high effect in making the molecular weight of a polypropylene higher.

Abstract: The invention relates to 1,2-ferrocenyldiphosphines which contain a functional group in the 1′ position either directly or via a bridging group, and also a process for their preparation. The compounds are important for transition metal complexes containing d-8 metals such as Rh, Ru, Pd or Ir. These transition metal complexes are widely used in the hydrogenation of organic double or triple bonds, in particular olefinic double bonds and carbon-heteroatom double bonds. The complexes are particularly suitable for enantioselective hydrogenation using chiral ferrocenyldiphosphines and corresponding prochiral unsaturated compounds. Ferrocenyldiphosphines having a functional group in the 1′ position are also important intermediates for ferrocenyldiphosphine ligands and their metal complexes of d-8 metals such as rhodium, ruthenium, palladium or iridium which are bound to inorganic polymeric supports via this functional group.

Abstract: Novel tripodal cyclopentadiene derivatives have the formula (I) ##STR1## where E are identical or different and are --N(R)(R), --P(R)(R), --As(R)(R), --Sb(R)(R), --OR, --SR, --SeR, --TeR, where R are identical or different and are each hydrogen, a C.sub.1 -C.sub.20 -carboorganic radical or a C.sub.1 -C.sub.30 -organosilicon radical, or E is a leaving group X andR.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5, R.sup.6 are identical or different and are each hydrogen, a C.sub.1 -C.sub.20 -carboorganic radical or a C.sub.1 -C.sub.30 -organosilicon radical,Z is a cyclopentadienyl radical or a substituted cyclopentadienyl structural unit andT is hydrogen, a C.sub.1 -C.sub.20 -carboorganic radical or a C.sub.1 -C.sub.30 -organosilicon radical or a group E--Y--, where E is --N(R)(R), --P(R)(R), --As(R)(R), --Sb(R)(R), --OR, --SR, --SeR, --TeR or a leaving group X, where R are identical or different and are each hydrogen, a C.sub.1 -C.sub.20 -carboorganic radical or a C.sub.1 -C.sub.

Abstract: Novel, highly effective catalyst compositions are described in which a low cost co-catalyst can be employed at very low aluminum loadings. Such compounds are composed of a cation derived from d-block or f-block metal compound, such as a metallocene, by loss of a leaving group, and an aluminoxate anion derived by transfer of a proton from a stable or metastable hydroxyaluminoxane to such leaving group. These catalyst compositions have extememly high catalytic activity and typically have high solubility in paraffinic solvents. Moreover they yield reduced levels of ash and result in improved clarity in polymers formed from such catalysts.

Abstract: Group 3-6 or Lanthanide metal complexes possessing two metal centers, 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: A process of preparing in high yield racemic ansa-metallocene complexes by reacting a chelated bisamide group 4 metal complex with an ansa-bis-cyclopentodrenyl dianion reagent. The meso isomers are not detectable in the reaction product.

Abstract: A catalyst useful for the polymerization of olefins, comprising the following components (A) and (B):Component (A): A transition metallic compound having the following formula [I]: ##STR1## wherein M: a transition metal selected from Ti, Zr and Hf; R.sup.1 : a monovalent C.sub.1-6 hydrocarbyl group, or a monovalent C.sub.1-6 hydrocarbyl group containing Si;R.sup.2 : a divalent C.sub.4-20 hydrocarbyl group, or a divalent C.sub.4-20 hydrocarbyl group containing Si;R.sup.3 : a divalent C.sub.1-30 hydrocarbyl group, or a divalent C.sub.1-30 hydrocarbyl group containing Si or Ge; andX and Y: H, halogen, a monovalent C.sub.1-20 hydrocarbyl group, or a monovalent C.sub.1-20 hydrocarbyl group containing N, O or Si.Component (B): Alumoxane having the following formula [II] or [III]: ##STR2## wherein m: 4 to 30; and R.sup.4 : a monovalent hydrocarbyl group. A highly stereoregular polyolefin having a high molecular weight can be obtained by the above catalyst.

Abstract: Disclosed is a process for preparing bridged Group 4 metal complexes containing a neutral diene ligand starting from the corresponding novel, metal diene containing complexes by reaction thereof with the divalent derivative of a bridged bidentate ligand compound. The novel, intermediate metal diene complexes, their formation from tetravalent metal salts and an integrated process combining both process steps are claimed.

Abstract: Cyclopentadienylplatinum (IV) compounds having a trisubstituted-silyl aliphatic group attached to platinum by carbon-platinum linkages have been found to be photo-active and effective as hydrosilylation catalysts in irradiation-curable silicone mixtures.

Abstract: Polysubstituted cyclopentadiene compound, in which at least one substituent is of the form -RDR'.sub.n, in which R is a bonding group, D is a hetero atom selected from group 15 or 16 of the Periodic System of the Elements, R' is a substituent and n is the number of R' groups bonded to D, and in that at least one further substituent is a branched alkyl group.

Abstract: A new family of metallacycles, which are preferably zirconacycles, is characterized by having a unique halogenated substituent. The metallacycles are useful for the preparation of main group heterocycles, especially two novel families of heterocycles. The first new family of heterocycles preferably contains a halosilyl substituent. A preferred group of the second family of novel heterocycles contains a silyl group having a leaving group bonded thereto. The preferred group of these heterocycles is suitable for preparing novel organometallic complexes having a bridged bidentate heterocyclic ligand. These novel organometallic complexes may be used as catalyst components in olefin polymerization. The subject catalyst components are particularly well suited for use in the medium pressure solution process to prepare linear low density polyethylene.

Abstract: Metal complexes useful as components of addition polymerization catalysts are prepared by oxidizing Group 4 or Lanthanide metal containing complexes using an organic halide oxidizing agent in a unique one electron oxidation.

Abstract: Metallocene compound and its use as catalyst component The present invention relates to a multinuclear metallocene compound of the formula I, ##STR1## where M.sup.1 is a tetravalent metal, L.sup.1 are, independently of one another, identical or different and are each a substituted cyclopentadienyl group, L.sup.2 and L.sup.3 are, independently of one another, identical or different and are each a .pi. ligand, B are, independently of one another, identical or different and are each a divalent bridging unit, X are, independently of one another, identical or different and are each a hydrogen atom, a halogen atom, a C.sub.1 -C.sub.10 -fluorocarbon radical or a hydrocarbon-containing radical having 1-40 carbon atoms, and k is an integer from 0 to 10. The metallocene compound of the present invention is suitable as a catalyst component for preparing olefin polymers.

Abstract: The present invention relates to nietallocene compounds characterized by the following formulas:(LR.sub.k).sub.z [LR.sub.k-f (R.sup.I OH).sub.f ].sub.x MX.sub.yI ##STR1## wherein: L, equal to or different from each other, is selected from the group comprising: cyclopentadienyl, indenyl, tetrahydroindenyl, fluorenyl, octahydrofluorenyl or benzoindenyl; each R is independently selected from hydrogen, C.sub.1 -C.sub.20 alkyl, C.sub.3 -C.sub.20 cycloalkyl, C.sub.6 -C.sub.20 aryl, C.sub.3 -C.sub.20 alkenyl C.sub.7 -C.sub.20 arylalkyl, C.sub.7 -C.sub.20 alkylaryl, C.sub.8 -C.sub.20 arylalkenyl, linear or branched, optionally substituted by 1 to 10 halogen atoms, or a group SiR.sup.II.sub.3 ; each R.sup.I equal to or different from each other, is a group SiR.sup.II.sub.

Abstract: Provided is method of synthesizing stereorigid metallocene having chiral center and enriching its rac isomer content; comprising steps of:a) selecting desired cyclopentadienyl ring-containing compound capable of forming metallocene with chiral center and dissolving compound in suitable solvent;b) contacting mixture of a), under suitable conditions of mixing and temperature for sufficient time to react, with suitable alkyl alkali metal compound;c) dissolving solid created in b) with sufficient suitable solvent;d) contacting solution created in c) with suitable halogenated compound with which bridge between two cyclopentadienyl ring-containing compounds may be formed, under suitable conditions of mixing and temperature for sufficient time to react;e) removing solvent, and, optionally, removing residual starting cyclopentadienyl ring-containing compound;f) dissolving solid created in e) in suitable solvent and contacting with suitable alkyl alkali metal compound under suitable conditions of temperature and mixin

Abstract: A method for purifying a transition metal compound, which comprises conducting crystallization of a transition metal compound from a solution containing the transition metal compound while stirring.According to the present invention, it is possible to purify and produce efficiently a transition metal compound at high purity under industrially and economically advantageous conditions.

Abstract: Disclosed are novel cyclopentadienyl transition metal compounds that are stable under a wide variety of conditions, particularly under conditions that include exposure to water and oxygen containing media. These novel compounds can be utilized in preparing novel catalyst systems useful in polymerizing olefins. The cyclopentadienyl compound can specifically be [(C5H4CH2CH2N[H]Me2)TiCl3]+B[C6F5]4-. Also disclosed are processes for preparing the novel cyclopentadienyl transition metal compounds.

Abstract: Novel metallocene compounds are provided which are useful as polymerization catalysts, particularly in the polymerization of addition polymerizable monomers such as olefinic or vinyl monomers. Preferred polymer compositions prepared using the novel catalysts are bimodal or multimodal in nature, typically having a bimodal or multimodal molecular weight distribution. The metallocenes are binuclear or multinuclear, and contain two or more chemically distinct active sites. Methods for synthesizing the novel catalysts are also provided, as are methods for using the novel compounds as homogeneous or heterogeneous polymerization catalysts.

Abstract: Abstract of the Disclosure: Catalyst systems for the polymerization of C.sub.2 -C.sub.10 -alk-1-enes contain, as active components,a) a metallocene complex of the general formula I ##STR1## where M is titanium, zirconium, hafnium, vanadium, niobium or tantalum, X is halogen or C.sub.1 -C.sub.8 -alkyl, Y is carbon, phosphorus, sulfur, silicon or germanium, Z is C.sub.1 -C.sub.8 -alkyl, C.sub.3 -C.sub.10 -cycloalkyl or C.sub.6 -C.sub.10 -aryl, R.sup.1 and R.sup.2 are identical or different and are each C.sub.1 -C.sub.4 -alkyl, R.sup.3 to R.sup.6 are identical or different and are each hydrogen or C.sub.1 -C.sub.8 -alkyl, or two adjacent radicals R.sup.3 and R.sup.4 and R.sup.5 and R.sup.6 in each case together form a hydrocarbon ring system of 4 to 15 carbon atoms and n is 0, 1 or 2, andb) an open-chain or cyclic alumoxane compound of the general formula II or III ##STR2## where R.sup.7 is C.sub.1 -C.sub.4 -alkyl and n is from 5 to 30.

Abstract: The present invention relates to a transition metal compound of the formula I ##STR1## where M.sup.1 is a metal of group IIIb, IVb or Vb of the Periodic Table of the Elements,R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are identical or different and are each a hydrogen atom, a halogen atom, a C.sub.1 -C.sub.40 -hydrocarbon-containing group, an --SiR.sup.5.sub.3, --NR.sup.5.sub.2, --Si(OR.sup.5).sub.3, --Si(SR.sup.5).sub.3 or --PR.sup.5.sub.2 radical, where R.sup.5 are identical or different and are each a halogen atom, a C.sub.1 -C.sub.10 -alkyl group or a C.sub.6 -C.sub.10 -aryl group, or two or more radicals R.sup.1, R.sup.2, R.sup.3 or R.sup.4 together with the atoms connecting them form a ring system,Y are identical or different and are each a hydrogen atom, a C.sub.1 -C.sub.40 -hydrocarbon-containing group, an OH group, a halogen atom or an NR.sup.5.sub.2 group,k is an integer which corresponds to the valence of the transition metal atom M.sup.1 minus two and if Y is a butadiene unit, k is 1,A is a bridge,R.

Abstract: Titanium and zirconium complexes comprising one or more, cyclic, delocalized .pi.-bonded ligand groups wherein the metal of said complexes is in the +2 formal oxidation state are prepared in high yield and purity by reaction of the corresponding titanium or zirconium halides in the +3 or +4 oxidation state with a di(C.sub.1-20 alkyl) magnesium reagent. The complexes are used as catalyst components for olefin polymerization catalysts.

Abstract: There is disclosed a method for producing an alkoxytitanium complex of formula (I), ##STR1## wherein Cp is a group having cyclopentadiene-type anion skeleton, A represents a carbon atom or silicon atom, R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5 and R.sup.6 each independently represent a hydrogen atom, an alkyl group having 1 to 10 carbon atoms which optionally may be substituted and the like, and R.sup.7 each independently represents an alkyl group having 1 to 10 carbon atoms which may be substituted and the like.

Abstract: Novel Si--N--Si bridged metallocenes of the formula [L--Si--Me.sub.2 NRSiMe.sub.2 L]MX.sub.2 wherein L is a C.sub.5 H.sub.4, C.sub.9 H.sub.6, or C.sub.13 H.sub.8 radical, R is alkyl and M is zirconium, titanium, or hafnium, and X is selected from the group consisting of chlorine, bromine, iodine, methyl and diethyl amine, are provided via a novel amine elimination reaction followed by cyclization of the ligand sphere of the amino silyl functionalized metallocene dichloride complex. Further, there is provided novel unbridged metallocene precursors of the formula [RNH--SiMe.sub.2 --L].sub.2 MX.sub.2. Such Si--N--Si bridged metallocenes in combination with an organometallic compound of metals of Group IA, IIA, and IIB form a catalyst system which is highly active in the polymerization of alpha-olefins.

Abstract: A catalyst component for the polymerization of alpha-olefins, represented by the following formula [I]: ##STR1## wherein R.sup.1 -R.sup.3 =H, a halogen, a C.sub.1-10 hydrocarbon radical, a Si-containing C.sub.1-18 hydrocarbon radical, or a halogen-containing C.sub.1-10, hydrocarbon radical (provided that R.sup.1 and R.sup.2 cannot be hydrogen at the same time); n=2 to 7; Q=a C.sub.1-20 hydrocarbon radical, a silylene or oligosilylene group having or not having a C.sub.1-20 hydrocarbon radical, a germylene group having or not having a C.sub.1-20 hydrocarbon radical; X and Y=H, a halogen, a C.sub.1-20 hydrocarbon radical, or an O- or N-containing C.sub.1-20 hydrocarbon radical; and M=a transition metal selected from the groups IVB-VIB; a catalyst for the polymerization of alpha-olefins, comprising the catalyst component; and a process for producing alpha-olefin polymers, where use is made of the catalyst.

Abstract: Disclosed is a process for preparing bridged Group 4 metal complexes containing a neutral diene ligand starting from the corresponding novel, metal diene containing complexes by reaction thereof with the divalent derivative of a bridged bidentate ligand compound. The novel, intermediate metal diene complexes, their formation from tetravalent metal salts and an integrated process combining both process steps are claimed.

Abstract: Catalyst compositions that are highly tolerant of catalyst poisons comprising a cationic or zwitterionic Group 4 metal complex of the constrained geometry type and an organoaluminum hydrocarbyloxide compound according to the formula R.sup.1.sub.2 Al(OR.sup.2),wherein R.sup.1 and R.sup.2 independently each ocurrence are C.sub.1-30 hydrocarbyl,the molar ratio of complex to organoaluminum hydrocarbyloxide compound being from 1:0.1 to 1:100.

Abstract: A process is provided for preparing polymer compositions which are multimodal in nature. The process involves contacting, under polymerization conditions, a selected addition polymerizable monomer with a metallocene catalyst having two or more distinct and chemically different active sites, and a catalyst activator.

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.