Abstract: The invention provides a process for producing an olefin polymerization catalyst, comprising an organometallic compound of a transition metal or of an actinide or lanthanide, in the form of solid catalyst particles, comprising forming a liquid/liquid emulsion system which comprises a solution of one or more catalyst components dispersed in a solvent immiscible therewith; and solidifying said dispersed phase to convert said droplets to solid particles comprising the catalyst and optionally recovering said particles.

Abstract: A supported catalyst composition having improved flow properties is disclosed comprising an alkylalumoxane, a metallocene-alkyl an inorganic oxide support having an average particle size of from 0.1 to 50 ?m and calcined at a temperature greater than 600° C., and optionally an antifoulant agent and. In one embodiment, the metallocene-alkyl is a Group 4, 5 or 6 metallocene-alkyl, and in another embodiment is a hafnocene-alkyl. Also disclosed is a method of polymerization using such a supported catalyst composition.

Abstract: A method for the preparation of a supported transition metal catalyst system which includes the steps of: (i) mixing together in a suitable solvent (a) an aluminoxane and (b) an ionic activator containing a cation and an anion, wherein the anion has at least one substituent containing a moiety having an active hydrogen, (ii) addition of the mixture from step (i) to a support material, and (iii) addition of a transition metal compound in a suitable solvent. The use of tetraisobutylaluminoxane as the aluminoxane results in a more stable activity profile and improved polymer properties in particular melt strength.

Abstract: The present invention relates to an adduct comprising MgCl2, an alcohol (ROH) in which R is a C1-C10 hydrocarbon group, and a compound containing a transition metal M selected from the Groups 3 to 11 or the lanthanide or actinide groups of the Periodic Table of the Elements (new IUPAC version) in an amount such as to give a weight of M atoms lower than 10% based on the total weight of the adduct. The catalyst components that are obtained by reacting the adducts with halogenating agents show very high specific activity.

Abstract: Alpha-olefin are manufactured in high yield and with very high selectivity by contacting ethylene with an iron complex of a selected 2,6-pyridinedicarboxaldehyde bisimine or a selected 2,6-diacylpyridine bisimine, and in some cases a selected activator compound such as an alkyl aluminum compound. Novel bisimines and their iron complexes are also disclosed. The ?-olefin are useful as monomers and chemical intermediates.

Abstract: This invention relates to a method to support one or more catalyst compounds comprising contacting the catalyst compounds with a pretreatment agent comprising an aluminum alkyl and or an alumoxane in solution and thereafter contacting the combination with a supported activator.

Abstract: Disclosed herein are a method for preparing a cis-1,4-polybutadiene with a controlled molecular weight distribution, comprising polymerizing butadiene monomers using a rare-earth catalyst system comprising: (a) at least one aliphatic hydrocarbon-soluble organometallic compound comprising at least one metal element chosen from the elements of atomic numbers 51-71 in the periodic table; (b) at least one organoaluminum compound of the formula: AlR1R22, (c) at least one aliphatic hydrocarbon-soluble halogen-containing compound; (d) optionally at least one alkylaluminum alkoxide; and (e) at least one conjugated double bond-containing organic compound, and methods of preparing the rare-earth catalyst system.

Abstract: Process to polymerize olefins comprising contacting, in a polymerization system, olefins having three or more carbon atoms with a catalyst compound, activator, optionally comonomer, and optionally diluent or solvent, at a temperature above the cloud point temperature of the polymerization system and a pressure no lower than 10 MPa below the cloud point pressure of the polymerization system, where the polymerization system comprises any comonomer present, any diluent or solvent present, the polymer product, where the olefins having three or more carbon atoms are present at 40 weigh % or more.

Abstract: Bisimine compounds of the formula (I) where the symbols have the following meanings: A is a nonmetal selected from among N, S, O and P, R1 is a radical of the formula NR5R6, R2 is a radical of the formula NR5R6 or NR7R8, alkyl, aryl or cycloalkyl, R5 and R6 together with the N atom form a 5-, 6- or 7-membered ring in which one or more of the —CH— or —CH2— groups may be replaced by suitable heteroatom groups and which may be saturated or unsaturated and unsubstituted or substituted or be fused with further carbacyclic or heterocarbacyclic 5- or 6-membered rings which may in turn be saturated or unsaturated and substituted or unsubstituted, and R7 and R8 are, independently of one another, alkyl, aryl or cycloalkyl radicals, and R3, R4 are, independently of one another, H or alkyl, aryl or cycloalkyl radicals, and n is 1 or 2, are used to prepare bisimidinato complexes which can be used in the polymerization of unsaturated compounds.

Abstract: The present invention relates to a novel fulvene compound and a preparation method thereof, and more particularly to a fulvene compound having substituted groups in the 2- and 5-positions, prepared from an unsaturated ketone having a substituted group in the ?-position and a halogen atom in the ?-position, and a preparation method thereof. The present invention also relates to a metallocene catalyst having a substituted group in the ?-position carbon of the bridge of the cyclopentadienyl group only by reaction of a fulvene compound and an anion group including the cyclopentadienyl group, and a preparation method of a polyolefin copolymer using the same.

Abstract: A process to produce ethylene polymers is provided.

Abstract: A method for producing a catalyst for use in the dehydrogenation of ethylbenzene to styrene is disclosed. The catalyst of the present invention comprises a high purity metal and at least one promoter in the form of solid oxides, oxide hydrates, hydroxides, hydroxycarbonates or metals. The catalyst is prepared via a method which comprises the preparation of at least one high purity iron precursor with or without an additional support material and which uses a nominal amount of water in the catalyst production. The catalyst pellets prepared with the high purity metal precursor are essentially free of sulfur and chloride contaminants.

Abstract: A compound of the formula Ia or Ib; where, in the formula Ia, E1 is O, S, Se, Te, NR, CR2, or PR; E2, E3 are each CR, N, or P; E4 is N, or P; E5 is OH, SH, NHR, OR?, SR?, or NRR?; E6 is NH, PH, NR?, or PR?; R5, R6 are each hydrogen or a linear, branched or cyclic alkyl radical or an aryl radical; R1, R2, R3, R4 are each hydrogen, a linear, branched or cyclic alkyl radical, an aryl radical, a halogen or a nitro group; R is hydrogen, a linear, branched or cyclic alkyl radical; R? is a linear, branched or cyclic alkyl radical; where at least one of the groups E5 and E6 contains a hydrogen atom; and in the formula Ib, the symbols E1, E4, E5, E6, R5, R6, R1, R2, R3, R4, R and R? are as defined in formula Ia; and E?2 and E?3 are each O, S, Se, Te, NR, CR2, or PR.

Abstract: A catalyst precursor composition comprising a) a source of chromium, molybdenum or tungsten; b) a first ligand having the general formula (I); (R1)(R2)P—X—P(R3)(R4)??(I) wherein X is a bivalent organic bridging group; R1 and R3 are independently selected from, hydrocarbyl, substituted hydrocarbyl, heterohydrocarbyl and substituted heterohydrocarbyl groups, with the proviso that when R1 and R3 are aromatic groups they do not contain a polar substituent at any of the ortho-positions; R2 and R4 are independently selected from optionally substituted aromatic groups, each R2 and R4 bearing a polar substituent on at least one of the ortho-positions; and c) a second ligand having the general formula (II); (R1?)(R2?)P—X?—P(R3?)(R4?)??(II) wherein X? is a bridging group of the formula —N(R5?)—, wherein R5? is selected from hydrogen, a hydrocarbyl group, a substituted hydrocarbyl group, a heterohydrocarbyl group, a substituted heterohydrocarbyl group, a silyl group or derivative thereof; and R1?, R2?, R3? and R4?

Abstract: The present invention refers to a metallocene catalyst component for producing polyolefins according to formula (I) R?s (CpRn)g (CpRn) M Q3-g (I) or according to formula (II) R?(CpRn)MeXQ (II) wherein—each Cp is a substituted or unsubstituted cyclopentadienyl ring with the bridge-head position of at least one of the cyclopentadienyl rings being occupied by a silicon atom;—each R is the same or different and is hydrogen or a hydrocarbyl radical such as alkyl, alkenyl, aryl, alkylaryl or arylalkyl radical containing from 1 to 20 carbon atoms or two carbon atoms are joined together to form a C4-C6 ring; —R? is a structural bridge between two Cp rings;—M is a group IIIB, IVB, VB or VIB metal;—Q is a hydrocarbyl radical such as aryl, alkyl, alkenyl, alkylaryl or arylalkyl radical having from 1 to 20 carbon atoms, a hydrocarboxy radical having from 1 to 20 carbon atoms or a halogen and can be the same or different from each other;—s is 0 or 1, g is 0, 1 or 2 and s is 0 when g is 0, n is 4 when s is 1 and n is 5 whe

Abstract: A metallocene compound represented by the following Chemical Formula 1: wherein M is a transition metal of Group 4; Cp denotes a cyclopentadienyl ring unsubstituted or substituted by hydrogen, alkyl, cycloalkyl, aryl, alkenyl, alkylaryl, arylalkyl or arylalkenyl radicals; Qs, which are the same or different, are halogen radicals, alkyl, alkenyl, aryl, alkylaryl, or arylakyl radicals having 1 to 20 carbon atoms, or alkylidene radicals having 1 to 20 carbon atoms; A? is methoxymethyl, t-butoxymethyl, tetrahydropyranyl, tetrahydrofuranyl, 1-ethoxyethyl, 1-methyl-1-methoxyethyl, or t-butyl; and a is an integer of 4 to 8. The metallocene compounds in this invention can be strongly supported on the inorganic support, and the supported catalyst of this invention allows for an olefin polymerization process without any fouling in the reactor, and produces a polymer with better morphology and bulk density.

Abstract: A metallocene compound of formula (I): wherein M is zirconium, titanium and hafnium; X is a hydrogen atom, a halogen atom or a hydrocarbon radical; R1 is a linear C1-C20-alkyl radical; R2 is a hydrogen atom or hydrocarbon R3, R4, R5, R6, R7, and R8, are hydrogen atoms or hydrocarbon radicals, A is a sulphur (S) atom or an oxygen (O) atom; Q is a radical of formula (II), (III) or (IV) being bonded to the indenyl at the position indicated by the symbol *; (II), (III), (IV) wherein T1 is a sulphur atom, an oxygen (O) atom or a NR; R9, R10 and R11 are hydrogen atoms or hydrocarbon radicals; T2, T3, T4, T5, and T6 are carbon atoms (C) or nitrogen atoms (N); m1, m2, m3, m4 and m5 are 0 or 1; R12, R13, R14, R15 and R16 are hydrogen atoms or hydrocarbon radicals with the provisos that at least one of R12, R13, R14, R15 and R16 is different from hydrogen atoms, and that no more than two of T2, T3, T4, T5 and T6 are nitrogen atoms.

Abstract: A new class of heterocyclic metallocenes, a catalytic system containing them and a process for polymerizing addition polymerizable monomers using said catalytic system are disclosed; the heterocyclic metallocenes correspond to the formula (I): YjR?iZjjMeQkPl wherein Y is a coordinating group containing a six ? electron central radical directly coordinating Me, to which are associated one or more radicals containing at least one non-carbon atom selected from B, N, O, Al, Si, P, S, Ga, Ge, As, Se, In, Sn, Sb and Te; R? is a divalent bridge between the Y and Z groups; Z is a coordinating group, optionally being equal to Y; Me is a transition metal; Q is halogen or hydrocarbon substituents; P is a counterion; i is 0 or 1; j is 1–3; jj is 0–2; k is 1–3; and l is 0–2.

Abstract: A tethered ligand comprising the reaction product of an organofunctional silica and a ligand containing a functional group capable of reaction with said organofunctional silica, wherein the organofunctional silica is prepared from an alkyl silicate and an organofunctional silane is described. A supported catalyst is also described comprising additionally a source of catalytically-active metal. Methods for preparing the tethered ligand and supported catalyst are provided and uses of the supported catalyst for performing asymmetric reactions are claimed. The catalysts are readily separable from the reaction mixtures and may be re-used if desired.

Abstract: A process for the preparation of a catalyst system includes the steps of combining a Lewis base, an organic compound having at least one functional group containing active hydrogen, and an organometallic component with a particulate support material to provide an intermediate composition, and then combining the intermediate composition with one or more metallocene compound. The catalyst system is advantageously used for olefin polymerization.

Abstract: The present invention is for a process for making a catalyst for production of unsaturated aldehydes, such as methacrolein, by gas phase catalytic oxidation of olefins, such as isobutylene, said catalyst containing oxides of molybdenum, bismuth, iron, cesium, tungsten, cobalt, nickel, antimony, magnesium and zinc. The process is a two-part synthesis of the catalyst with the water insoluble components in one part and the water soluble components in the other part. The water insoluble components are co-precipitated to form an intermediate catalyst precursor of a precipitated support incorporating oxides of the metal components. The intermediate catalyst precursor is filtered and washed to remove nitrates. The intermediate catalyst precursor is slurried with the remaining water soluble components. A final catalyst precursor is formed by removing the water and incorporating the water soluble components. This two-part process reduces the amount of nitrates in the final catalyst precursor.

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: This invention relates to transition metal catalyst compounds represented by the formula: LMX2 wherein M is a Group 7 to 11 metal; L is a tridentate or tetradentate neutrally charged ligand that is bonded to M by least three or four nitrogen atoms, and at least one terminal nitrogen atom is part of a pyridinyl ring, a different terminal nitrogen atom is substituted with one C3–C50 hydrocarbyl, and one hydrogen atom or two hydrocarbyls; wherein at least one hydrocarbyl is a C3–C50 hydrocarbyl, and the central nitrogen atom is bonded to at least three different carbon atoms or two different carbon atoms, and one hydrogen atom; X is independently a monoanionic ligand or both X are joined together to form a bidentate dianionic ligand.

Abstract: Catalyst component for the polymerization of alpha-olefins in solution, in suspension, in gas phase at low and high pressure and temperature or in mass at high pressures and high or low temperatures, characterized in that is defined by general formulas I or II wherein: R, equal to or different from each other, is hydrogen or a radical which contains from 1 to 20 carbon atoms; this group optionally contains heteroatoms of groups 14 to 16 of the periodic table of the elements and boron; at least one group R contains a group OSiR?3, Q is selected from a group comprising: boron or an element from groups 14 or 16 of the periodic table; m value can change from 1 to 4 and it preferably is 1 or 2; L, equal to or different from each other, is a cyclic organic group united to M through a ? bond, or it is an atom from groups 15 or 16 of the periodic table; L1 and L2, equal to or different from each other, have the same meaning of L; M is a metal from groups 3, 4, 10 of the periodic table, lanthanide or actinide.

Abstract: A catalyst is synthesized by a method in which a catalytic metal such as platinum or another noble metal is dispersed onto a support member. A transition metal macrocycle is also adsorbed onto the support, and the support is heat treated so as to at least partially pyrolyze the macrocycle and anchor the transition metal to the support. The catalytic metal is alloyed with the transition metal either during the pyrolysis step, or in a separate step. The catalyst has significant utility in a variety of applications including use as an oxygen reduction catalyst in fuel cells.

Abstract: A production process and a catalyst are provided, which can be less decreased in activity of the catalyst even when CO2, water and the like are present in the starting material and/or the reaction system, and which can produce a formic ester or a methanol at a low temperature and a low pressure. The present invention relates to a process for producing methanol, comprising reacting carbon monoxide with an alcohol in the presence of an alkali metal-type catalyst, and/or an alkaline earth metal-type catalyst to produce a formic ester, wherein a hydrogenolysis catalyst of formic ester and hydrogen are allowed to be present together in the reaction system to hydrogenate the produced formic ester and thereby obtain a methanol.

Abstract: The invention is a catalyst system including a Group IV B transition metal component and an alumoxane component which may be employed to polymerize olefins to produce a high molecular weight polymer.

Abstract: Monocyclopentadienyl complexes in which the cyclopentadienyl system bears at least one uncharged donor bound via a boron-containing bridge and comprising one or more atoms of group 15 and/or 16 of the Periodic Table of the Elements and is bound to a metal selected from the group consisting of titanium in the oxidation state 3, vanadium, chromium, molybdenum and tungsten, a catalyst system comprising at least one of the monocyclopentadienyl complexes, the use of the catalyst system for the polymerization or copolymerization of olefins and a process for preparing polyolefins by polymerization or copolymerization of olefins in the presence of the catalyst system and polymers obtainable in this way.

Abstract: A catalyst for the oligomerization of olefins, especially ethylene contains: at least one nickel complex e.g. Li2 Ni X2 that results from bringing into contact a nickel salt e.g. a nickel carboxylate with a bidentate chelating ligand containing a nitrogen-containing heterocyclic compound with an alcohol e.g. Ha-C(OH)RR?; and at least one hydrocarbylaluminum compound from tris(hydrocarbyl)aluminum compounds, chlorinated or brominated hydrocarbylaluminum compounds or at least one aluminoxane.

Abstract: The invention provides ethylene/?-olefin copolymers exhibiting improved environmental stress cracking resistance properties, and methods for the production of the copolymers in a single reactor by means of a bimetallic catalyst including a Ziegler component and a metallocene component.

Abstract: A 3+ metal complex for coordination polymerization of olefins is disclosed. The precursor metal complex is stabilized by a anionic multidentate ligand and at least two monoanionic ligands. The multidentate ligand and the transition metal form a metallocycle having at least five primary atoms, counting any ?-bound cyclopentadienyl group in the metallocycle as two primary atoms. Olefin polymerization is exemplified.

Abstract: The application describes a mixed olefin polymerization catalyst composition comprising a support, a reaction product of at least one first organometallic compound and a first activator capable of rendering the first organometallic compound active for insertion polymerization, and at least one second organometallic compound, the activator incapable of rendering the second organometallic compound active for polymerization of the monomers. The mixed catalyst composition can be used to prepare a first polymer component in a first polymerization reactor stage and then, when an effective activator is added for the second organometallic compound, the catalyst composition can be used to prepare a second polymer composition that is homogeneously blended with the first polymer component.

Abstract: The invention relates to a process for preparing racemic metallocene biphenoxide complexes by reacting bridged transition metal complexes with cyclopentadienyl derivatives of alkali metals or alkaline earth metals and heating the reaction mixture obtained in this way to a temperature in the range from ?78 to 250° C., to the corresponding metallocene biphenoxide complexes and to their use as catalysts or as constituents of catalysts for the polymerization of olefinically unsaturated compounds or as reagents or catalysts in stereoselective synthesis.

Abstract: A method for preparing an olefin polymerization catalyst is disclosed. An inorganic oxide is contacted with plasma and a transition metal compound is supported on the contacted inorganic oxide. The method is fast, convenient, and avoids many of the problems associated with known methods of supporting catalysts.

Abstract: A process for hydrogenation of an unsaturated polymer. The conjugated diene polymer in an inert organic solvent is brought into contact with hydrogen in the presence of a hydrogenation catalyst composition to selectively hydrogenate the unsaturated double bonds in the conjugated diene units of the conjugated diene polymer. The hydrogenation catalyst composition includes: (a) a titanium compound; (b) a compound represented by formula (II) or formula (III): wherein L1 is a Group IVA element, L2 is a Group IVA element, R3 is C1–C12 alkyl or C1–C12 cycloalkyl, R4 is C2–C12 alkyl or C3–C12 cycloalkyl, and X1, X2, and X3 can be the same or different and are C1–C12 alkyl, C1–C12 alkoxy, C1–C12 cycloalkoxy, phenyl, or phenoxy; and (c) a trialkylaluminum compound.

Abstract: Copolymerization of Ni(H) or Co(II) acenaphthene diimine complexes containing olefinic substituents on aryl groups in the presence of a free radical initiator results in polymerized late transition metal catalysts which can be used for olefin polymerization or oligomerization. These catalysts have high catalyst activity for olefin polymerization or oligomerization.

Abstract: The invention relates to highly active spherical metal support catalysts with a metal content of 10 to 70% by mass, and a process for their production with the use of a mixture of polysaccharides and at least one metal compound which is dropped into a metal salt solution.

Abstract: Bimetallic catalysts, and methods of producing a bimetallic catalyst comprising a modified Ziegler-Natta catalyst and a metallocene are provided, in one embodiment the method including combining: (a) a Ziegler-Natta catalyst comprising a Group 4, 5 or 6 metal halide and/or oxide, optionally including a magnesium compound, with (b) a modifier compound (“modifier”), wherein the modifier compound is a Group 13 alkyl compound, to form a modified Ziegler-Natta catalyst. Also provided is a method of olefin polymerization using the bimetallic catalyst of the invention. The modified Ziegler-Natta catalyst is preferably non-activated, that is, it is unreactive towards olefin polymerization alone. In one embodiment, the molar ratio of the Group 13 metal (of the modifier) to the Group 4, 5 or 6 metal halide and/or oxide is less than 10:1 in one embodiment.

Abstract: This invention relates to the field of olefin polymerization catalyst compositions, and methods for the polymerization and copolymerization of olefins, including polymerization methods using a supported catalyst composition. In one aspect, the present invention encompasses a catalyst composition comprising the contact product of at least one metallocene compound, at least one organochromium compound, at least one chemically-treated solid oxide, and at least one organoaluminum compound.

Abstract: The present invention relates to a method for preparing neodymium-carbon-nanotube and a process for preparing 1,4-cis-polybutadiene utilizing the same and more particularly, neodymium-carbon-nanotube. Neodymium is introduced by coordination with carboxylic acid, which is formed on the surface of carbon nanotube. In 1,3-butadiene polymerization with the neodymium-catalyst comprising the neodymium-carbon nanotube, a particular halogen compound, and a particular organometallic compound in an appropriate ratio, high 1,4-cis polybutadiene having molecular weight of 10,000 to 2,000,000 is produced, which exhibits excellent mechanical properties such as elasticity and durability.

Abstract: The present invention describes a novel group of specific transition metal compounds, referred to as nonmetallocene compounds, and catalyst systems prepared therefrom. These catalyst systems which have become obtainable for the first time are suitable for the polymerization of olefins.

Abstract: Heterogeneous catalytic compositions obtained by reacting a porous inorganic support with an alumoxane and subsequently supporting at least one metallocene compound thereon. A process for polymerization of ?-olefins in a slurry or in a gas phase, the process catalyzed by such heterogeneous catalytic compositions.

Abstract: A polymerization catalyst system, containing a specified ratio of two iron complexes of a bisimine of 2,6-diacylpyridine or a bisimine of a 2,6-pyridinedicarboxaldehyde which produce polyolefins of differing molecular weights, is useful for producing polyolefins, especially polyethylenes, which are particularly useful for blow molding.

Abstract: This invention is based upon the discovery that a catalyst system which is comprised of (a) palladium or a palladium compound and (b) a fluorinated alcohol is effective for polymerizing norbornene-functional monomers into polynorbornene-functional polymers. It has been further discovered that this catalyst system is more effective in polymerizing certain norbornene-functional monomers that are difficult to polymerize, such as norbornene ester monomers, than prior art catalyst systems. The activity of the catalyst systems of this invention can be further improved with respect to polymerizing some monomers by including a Lewis acid and/or a ligand, such as a phosphine or a carbene, in the system. In any case, the catalyst systems of this invention offer the advantage of being soluble in a wide variety of solvents, relatively inexpensive, and capable of polymerizing many norbornene-functional monomers that are difficult to polymerize with conventional catalyst systems.

Abstract: There are provided (1) a process for producing a compound, which comprises the step of contacting a compound (A) defined by the formula, M1L13, a compound (B) defined by the formula, R1t-1TH, and a compound (C) defined by the formula, R2t-2TH2; (2) a catalyst component for addition polymerization, which comprises a compound produced by said process; (3) a process for producing a polymerization catalyst, which comprises the step of contacting said catalyst component with a transition metal compound and an optional organoaluminum compound; and (4) a process for producing an addition polymer, which comprises the step of addition polymerizing an addition polymerizable monomer in the presence of a catalyst produced by said process.

Abstract: Metallocenes and catalyst systems for olefin polymerization derived therefrom. The metallocenes may be represented by the formula: wherein M1 preferably is zirconium or hafnium; and R12 is different from hydrogen.

Abstract: A metallocene compound of general formula (I): LGZMXp, wherein L is a divalent group, Z is a moiety of formula (II), wherein R3 and R4 are selected from hydrogen and hydrocarbon groups; A and B are selected from S, O or CR5, wherein R5 is selected from hydrogen and hydrocarbon groups, either A or B being different from CR5; G is a moiety of formula (III), wherein R6, R7, R8 and R9 are selected from hydrogen and hydrocarbon groups, M is an atom of a transition metal, X is selected from a halogen atom, a R10, OR10, OSO2CF3, OCOR10, SR10, NR102 or PR102 group, wherein the substituents R10 is hydrogen and a hydrocarbon group; p is an integer from 0 to 3.

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 of high stereospecificity and high melting point.

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 of high stereospecificity and high melting point.

Abstract: The present invention relates to zwitterionic neutral transition metal compounds. The compounds are suitable as catalyst components for the polymerization of olefins.