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: 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: 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 homoaromatic anionic ligand that is &pgr;-bonded to M. Molecular modeling results indicate that single-site catalysts based on homoaromatic anionic ligands (e.g., bicyclo[3.2.1]octa-2,6-dienyl) will rival the performance of catalysts based on cyclopentadienyl and substituted cyclopentadienyl ligands.

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 medium pressure process for the solution polymerization of ethylene at a temperature of from 80° C. to 250° C. in the presence of a catalyst system comprising (1) a catalyst component which is a group 4 metal complex having a delocalized, cyclic, pi-bonded ligand, a (defined, specific) heteroligand and one or two activatable ligands; and (2) an ionic activator which does not contain an active proton. The catalyst component is unbridged and easily synthesized. It is highly active in solution polymerization when properly activated (but is not active when used in combination with an alumoxane). Preferred catalyst systems contain an unbridged monocyclopentadienyl titanium (IV) complex and triphenylcarbenium tetrakis (pentafluorophenyl) borate.

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: 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 bridged chiral metallocene of the formula I and 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: Metallocene compounds of the formula where CpI and CpII are carbanions having a cyclopentadienyl-containing structure, D is a donor atom and A is an acceptor atom, where D and A are linked by a reversible coordinative bond in such a way that the donor group takes on a positive (partial) charge and the acceptor group takes on a negative (partial) charge, M represents a transition metal of transition group III, IV, V or VI of the Periodic Table of the Elements (Mendeleev), X is one anion equivalent and n is, depending on the charge of M, zero, one, two, three or four, are new and can be used as catalysts for the (co)polymerization of olefins, i-olefins, alkines and/or diolefins or for ring-opening polyaddition. A typical X-ray structure analysis is represented by formula 18a.

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: This invention relates to polymer blends and the process for preparing naturally compatibilized polyolefin blends using a “one-pot” polymerization of a single monomer, whereby two homopolymers having different structures are produced as well as a third block copolymer having alternating sequences of the two structural segments of the two homopolymers. The formation of the block copolymer is established by solvent extraction and 13C-NMR spectroscopy. The catalyst compositions enabling the direct synthesis of naturally compatibilized polymer blend is prepared by combining four components. The first two components are organometallic complexes of Group IVB or VIIIB elements. The third component is a cocatalyst which irreversibly reacts with at least one ligand on the transition metal complexes. The fourth component is a hydrocarbyl or oxyhydrocarbyl compound of Group IIIA metals, which functions as a cross-over agent.

Abstract: A di-substituted metallocene compound having good quality can be synthesized completely at a low cost in a high yield in a easy manner by reacting a metallocene dihalide with a Grignard reagent which is a compound represented by formula (I): RMgX (wherein R represents an aryl, benzyl or diaryl phosphinomethylene group which may have a substituent and X represents a halogen element) under specified conditions.

Abstract: A method for producing an alkyl cyclopentadiene by reacting cyclopentadienyl Grignard with an alkyl halide and for converting the alkyl cyclopentadiene to a bis(n-alkyl cyclopentadienyl) Group IV metal dihalide is described.

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: Fluorenyl-containing metallocenes are disclosed along with methods for making the metallocenes. Also disclosed are methods for using the metallocenes as polymerization catalysts. In addition, polymers resulting from such polymerizations are disclosed.

Abstract: A prepolymerized solid catalyst is prepared by reacting a suitable support base with an organoaluminum compound and then reacting that product with an activity promoting amount of water and then reacting the resulting solid cocatalyst with a metallocene and then subjecting that product to prepolymerization in the presence of hydrogen. The prepolymerized solid catalyst is useful in the polymerization of olefins.

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: The present invention relates to a new metallocene having the formula (I) ##STR1## where M is a metal of group IVb, Vb or VIb of the Periodic Table of the Elements, in particular Ti, Zr and Hf,X are identical or different and are each a hydrogen atom, a C.sub.1 -C.sub.40 -hydrocarbon group such as a C.sub.1 -C.sub.10 -alkyl, C.sub.1 -C.sub.10 -alkoxy, C.sub.6 -C.sub.10 -aryl, C.sub.6 -C.sub.10 -aryloxy, C.sub.2 -C.sub.10 -alkenyl, C.sub.7 -C.sub.40 -arylalkyl, C.sub.7 -C.sub.40 -alkylaryl or C.sub.8 -C.sub.40 -arylalkenyl group, an OH group, a halogen atom or a pseudohalogen such as nitrile,R.sup.1 to R.sup.5 are identical or different and, independently of one another, are each a hydrogen atom, a C.sub.1 -C.sub.30 -hydrocarbon radical such as C.sub.1 -C.sub.20 -alkyl or C.sub.6 -C.sub.20 -aryl, or a carbon-containing radical having from 1 to 10 carbon atoms and one or more heteroatoms selected from the group consisting of O, N, Si, Ge and P, where in each case two adjacent radicals R.sup.4 and/or R.sup.

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: Disclosed is a novel transition metal composition of a metallacycle structure represented by the formula ##STR1## wherein M.sup.1 is an element of Group IVB in the Periodic Table, M.sup.2 is an element of Group IIIA in the Periodic Table, R.sup.1 and R.sup.2 each are for instance a cyclopentadienyl group, R.sup.3 and R.sup.4 each are for instance a hydrocarbon group, R5 and R6 each are a hydrogen atom and R7 and R8 indicate an indan ring formed by bonding to each other.

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: Salts of (polyfluoroaryl)fluoroanions of aluminum, gallium, and indium are described. The (polyfluoroaryl)fluoroanions have the formula [ER'R"R'"F].sup..crclbar. wherein E is aluminum, gallium, or indium, wherein F is fluorine, and wherein R', R", and R'" is each a fluorinated phenyl, fluorinated biphenyl, or fluorinated polycyclic group.

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: Production of aryl cyclopentadienyl Group IVA metal dihalides by dehydrogenation of a substituted or unsubstituted bis-(cyclohexenylcyclopentadienyl) Group IVA metal dihalide is described.

Abstract: Polysubstituted cyclopentadiene compound, wherein at least one substituent is of the form --RDR'.sub.n, where R is a bonding group between the cyclopentadiene and the DR'.sub.n group, D is a hetero atom chosen from group 15 or 16 of the Periodic Table of the Elements, R' is a substituent and n is the number of R' groups bonded to D, and in which at least one further substituent is a linear alkyl group comprising at least 2 carbon atoms.

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: 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: 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: A catalyst system comprises an organometallic complex of a group 4 metal having a ketimide ligand. The organometallic complex preferably also contains a cyclic ligand which forms a delocalized pi-bond with the metal (such as a cyclopentadienyl-type ligand). Preferred organometallic complexes may be activated with a so-called "substantially non coordinating anion" to form a low cost cocatalyst system which is excellent for the preparation of olefin copolymers having both high molecular weight and very low density.

Abstract: Metal complexes, addition polymerization catalysts containing the same and olefin polymerization processes using the same comprising a boratabenzene group or divalent derivative thereof are disclosed.

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: 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 process for the preparation of a meso/racemic-(bis(indenyl)ethane zirconium dichloride compound comprising (a) reacting zirconium tetrachloride with the solid reaction product of the bis(indenyl)ethane ligand with an alkyllithium in a solvent as reaction medium and (b) recovering a solid mixture of lithium chloride and meso/racemic composition of (bis(indenyl)ethane) zirconium dichloride, characterized in that the solvent used as reaction medium in a reaction (a) is an ether, pentane or a mixture thereof.

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 asymmetric ethylene-bridged metallocenes useful as catalysts in the polymerization of olefins and process for preparing said metallocenes.The novel metallocenes are represented by the general formula: ##STR1## wherein M represents a transition metal selected from titanium, zirconium and hafnium and X and X' represent a halogen atom. Preferably, the transition metal is Zr and the halogen atoms are both chlorine.

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: 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: 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: 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: 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: 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: 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: Polysubstituted cyclopentadiene-containing compound, in which at least one substituent is has the formula --RDR'.sub.n, in which R is a linking group between the cyclopentadiene and the DR'.sub.n group, D is a hetero atom selected from group 15 or 16 of the Periodic Table of Elements or an aryl group, in which case R has at least the length of an ethylene group, R' is a hydrocarbon radical containing 1-20 carbon atoms (e.g., alkyl, aryl, aralkyl,. and the like, including straight chain, branched, cyclic, and derivatives thereof, and n is the number of R' groups bound to D (note that the R' groups may be identical or different).