Abstract: Improved methods for performing atomic layer deposition (ALD) are described. These improved methods provide more complete saturation of the surface reactive sites and provides more complete monolayer surface coverage at each half-cycle of the ALD process. In one embodiment, operating parameters are fixed for a given solvent based precursor. In another embodiment, one operating parameter, e.g. chamber pressure is altered during the precursor deposition to assure full surface saturation.

Abstract: There are provided organic acid anion containing aluminum salt hydroxide particles represented by the following general formula (I): Ma[Al1-xM?x]bAzBy(OH)n.mH2O??(I) (wherein M is at least one cation selected from the group consisting of Na+, K+, NH4+ and H3O+, M? is at least one metal cation selected from the group consisting of Cu2+, Zn2+, Ni2+, Sn4+, Zr4+, Fe2+, Fe3+ and Ti4+, A is at least one organic acid anion, B is at least one inorganic acid anion, and a, b, m, n, x, y and z satisfy 0.7?a?1.35, 2.7?b?3.3, 0?m?5, 4?n?7, 0?x?0.6, 1.7?y?2.4, and 0.001?z?0.5, respectively.) The particles are in the shape of grains, pairs, rectangular parallelepiped, disks (go stones), hexagonal plates, rice grains or cylinders and have a uniform particle diameter.

Abstract: The present invention relates to diarylphenoxyaluminum compounds which are obtainable by reacting a bis(diarylphenol) ligand of the formula (I) with an alkylaluminum compound and/or a complex aluminum hydride. The invention moreover relates to the use of such diarylphenoxyaluminum compounds as catalysts. Moreover, the invention relates to a method of producing isopulegol by cyclization of citronellal in the presence of diarylphenoxyaluminum compounds as catalysts. The invention also relates to a method of producing menthol by cyclization of citronellal in the presence of diarylphenoxyaluminum compounds as catalysts and subsequent hydrogenation.

Abstract: A compound represented by the formula: where: M is a transition metal selected from group 4 of the periodic table; each R1 is independently selected from the group consisting of hydrogen, hydrocarbyl, substituted hydrocarbyl and functional group, and any two R1 groups may be linked, provided that if the two R1 groups are linked, then they do not form a butadiene group when M is Zr; R3 is carbon or silicon; R4 is hydrogen, hydrocarbyl, substituted hydrocarbyl or a functional group; R5 is hydrogen, hydrocarbyl, substituted hydrocarbyl or a functional group, R4 and R5 may be bound together to form a ring; R6 is carbon or silicon; each R7 is hydrogen; each R8 is independently selected from the group consisting of hydrogen, methyl, ethyl, propyl, butyl, pentyl, hexyl and the isomers thereof; R10 is -M2(R16)h— where M2 is B, Al, N, P, Si or Ge, h is 1 or 2; each R9, R11, R13 and R14 and R16 is hydrogen, hydrocarbyl, substituted hydrocarbyl or a functional group, and two R16 groups may be linked together to f

Abstract: The present invention relates to an advanced preparation method of organic-transition metal hydride used as hydrogen storage materials, the method including: preparing organic-transition metal-aluminum hydride complexes by reacting the organic-transition metal halide with metal aluminum hydride compounds; and preparing the organic-transition metal hydride by reacting the organic-transition metal aluminum hydride complexes with Lewis bases. Since the preparation method of the organic-transition metal hydride according to the present invention does not use catalysts, it has advantages that it does not cause problems due to poisoning and can prepare the organic-transition metal hydride at high yield under less stringent conditions. The hydrogen storage materials containing the organic-transition metal hydride prepared from the preparation method can safely and reversibly store a large amount of hydrogen.

Abstract: The present invention mainly relates to a carbon-carbon bond formation catalyzed by a complex comprising a novel and stable ligand and a metal center. The ligand uses a ring, particularly a phenyl group, or a hydrocarbon group to link an amino group and PR1R2, NR1R2, OR1, SR1, or AsR1R2 group for stabling the structure of the ligand.

Abstract: The invention relates to a method for polymerising ethylenically unsaturated monomers, wherein ethylenically unsaturated monomers are polymerised in the presence of a solvent-stable transition metal complex having slightly co-ordinating anions as polymer catalysts. The invention also relates to specific solvent-stable transition metal complexes having slightly co-ordinating anions. The invention also relates to highly reactive copolymers which are made of monomers comprising isobutene and at least one vinylaromatic compound which can be obtained according to said inventive method.

Abstract: Hydrotalcites containing the anion of ethylenediaminetetraacetic acid are partially or fully thermally decomposed to provide catalysts useful for the conversion of ethanol to a reaction product comprising 1-butanol.

Abstract: A method of preparing an ultra-pure organometallic compound comprising using a microchannel device for synthesis in reacting a metal halide with an alkylating agent to produce an ultra-pure alkylmetal compound for processes such as chemical vapor deposition.

Abstract: The binoclear, oxygen-bridged, hetero-bimetallic complexes of general formula [(LM1R3)(Cp2M2R2)]?-O) are suitable as polymerization catalysts for olefin polymerization. (M1=Al, Ge, Zr or Ti; M2=Zr, Ti or Hf; Cp=cyclopentadienyl; R1, R2=methyl, ethyl, i-propyl, t-butyl, halogen, phenyl, alkylphenyl, SiMc3; L=bidental, doubly nitrogen-coordinated organochemical ligand, which together with metal M1 form a 5- or six membered ring). These complexes have very good catalytic activity, good useful life and require less cocatalysts.

Abstract: [PROBLEMS] To provide a metal complex compound capable of being suitably used for manufacturing a metal-containing thin film by the CVD method and a method for preparing a metal-containing thin film. [MEANS FOR SOLVING PROBLEMS] A metal complex compound comprising a ?-diketonato ligand having an alkoxyalkyl-methyl group, and a method for preparing a metal-containing thin film using the metal complex compound by the CVD method.

Abstract: Taught herein is a charge control agent comprising a specific type of gallic acid metal complex represented by the following Chemical Formula (1) or Chemical Formula (2): In the formula (1), R1 represents an alkyl group containing 1-12 carbon atoms, an Alkenyl group containing 1-12 carbon atoms, a substituted or unsubstituted aryl group containing 6-12 carbon atoms, or a hydrogen atom; R2 and R4 can independently represent an alkyl group containing 1-12 carbon atoms, an Alkenyl group containing 2-12 carbon atoms, an alkoxy group containing 1-12 carbon atoms, a substituted or unsubstituted aryl group containing 6-12 carbon atoms, a halogen atom, or a hydrogen atom; R3 represents an alkyl group containing 1-12 carbon atoms, a substituted or unsubstituted aryl group containing 6-12 carbon atoms, a potassium atom, a sodium atom or a hydrogen atom. M represents a divalent to tetravalent metal atom, A is a counterion, m is a number from 1 to 3, and n is 1 or 2.

Abstract: The present invention relates to a porous metal-organic framework comprising AlIII and at least one at least bidentate compound, wherein the at least one at least bidentate organic compound is a six-membered aromatic hydrocarbon ring A in which one or more ring carbons may be replaced by nitrogen and which has three substituents X and optionally one or more substituents selected from the group consisting of R, NRR?, OR, SR, F, Cl and Br, where R, R? are each, independently of one another, hydrogen, methyl which may optionally be substituted by one or more fluorine atoms or ethyl which may optionally be substituted by one or more fluorine atoms and each X is, independently of the others, C(?O)O?, C(?S)O?, C(?O)S?, C(?S)S? or a protonated form thereof. The invention further provides a process for preparing it and provides for the use of the new porous metal-organic framework.

Abstract: The invention relates to the use of nitrogenous aluminium organyl complexes of general formula (I) as co-catalysts in heterogeneous polymerisation reactions of propene. In said formula: R, R?, R1 and R1? independently of one another represent branched or unbranched C1-C7 alkyl, cycloalkyl, alkenyl, cycloalkenyl, aryl or alkynyl; R2 represents unsubstituted, monoalkylated or polyalkylated and/or monofluorinated or polyfluorinated aromatic hydrocarbons from group (II); R3 and R4 independently of one another represent CH2, CF2 oder C(R1)2; m stands for 0, 1 or 2; n stands for 0, 1 or 2; o stands for 0 or 1, all independently of one another.

Abstract: A method of purifying an organometallic compound by heating the organometallic compound in the presence of a trialkyl aluminum compound and a catalyst.

Abstract: A catalyst composition, and olefin polymerization process using same, formed from a mixture of a non-aluminoxane aluminum compound, an inorganic oxide and a transition metal bidentate or tridentate complex in certain prescribed proportions. The composition can be formed in a single step or in-situ in the polymerization reaction zone. The resultant catalyst has high activity and is capable of producing high molecular weight olefin products without reactor fouling.

Abstract: The present invention relates to the use of boron and aluminum compounds in electronics, in particular as electron transport material, as host material of the emission layer and as hole blocking material, in each case in phosphorescent OLEDs, and also to layers produced therefrom in phosphorescent OLEDs.

Abstract: A method is described for the manufacture of hydrotalcites by using at least one compound of a bivalent metal (Component A) and at least one compound of a trivalent metal (Component B), wherein at least one of these components is not used in the form of a solution, characterized in that a) at least one of the Components A and/or B which is not used in the form of a solution, shortly before or during mixing of the components, and/or b) the mixture containing the Components A and B is subjected to intensive grinding until an average particle size (D50) in the range of approx. 0.1 to 5 ?m is obtained, and optionally, after aging treatment or hydrothermal treatment, the resulting hydrotalcite product is separated, dried, and optionally calcinated.

Abstract: The present invention relates to a process for the preparation of hydrogen peroxide from oxygen or oxygen-delivering substances and hydrogen or hydrogen-delivering substances in the presence of at least one catalyst containing a metal-organic framework material, wherein said framework material comprises pores and a metal ion and an at least bidentate organic compound, said bidentate organic compound being coordinately bound to the metal ion. The invention further relates to a novel material consisting of said metal organic framework material wherein the material is brought in contact with at least one additional metal.

Abstract: A composition suitable for use as a catalyst for the reaction of an isocyanate compound or prepolymer thereof with an alcohol to form a polyurethane comprises a mixture of (a)an organometallic compound selected from: (i) a compound of formula M(RO)4, where M is titanium, zirconium, hafnium, aluminium, cobalt or iron or a mixture of these metals and OR is the residue of an alcohol ROH in which R comprises an (optionally substituted) C1-30 cyclic, branched or linear, alkyl, alkenyl, aryl or alkyl-aryl group or a mixture thereof, or; (ii) a complex of titanium, zirconium and/or hafnium and an acetoacetate ester and (b) a coordinating compound selected from a ketone, aldhehyde, carboxylic acid, sulphonic acid, nitride or an imine. An isocyanate composition containing a catalyst of the claimed composition is also described.

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 stabilized aluminum/zirconium/glycine salt comprising a Betaine of Formula I as additive: in a sufficient amount to have (a) an overall (Betaine+glycine)/Zr ratio in the range of 0.1–3.0:1, (b) a ratio of Betaine to glycine of at least 0.001:1; and (c) sufficient Betaine so that at least 0.1% of the ratio of Betaine+glycine is contributed by Betaine.

Abstract: This invention is related to heteroatom containing diamondoids (i.e., “heterodiamondoids”) which are compounds having a diamondoid nucleus in which one or more of the diamondoid nucleus carbons has been substitutionally replaced with a noncarbon atom. These heteroatom substituents impart desirable properties to the diamondoid. In addition, the heterodiamondoids are functionalized affording compounds carrying one or more functional groups covalently pendant therefrom. This invention is further related to polymerizable functionalized heterodiamondoids. In a preferred aspect of this invention the diamondoid nuclei are triamantane and higher diamondoid nuclei. In another preferred aspect, the heteroatoms are selected to give rise to diamondoid materials which can serve as n- and p-type materials in electronic devices can serve as optically active materials.

Abstract: A new class of zwitterionic metallocycles is disclosed. A positively charged Group 4-10 transition metal is chelated to two heteroatoms and one of the heteroatoms has a substituent bearing a negative charge. We have found that substitution in this position stabilizes the zwitterion form of the metallocycle. The zwitterionic metallocycle is useful for olefin polymerizations.

Abstract: Synthetic hydrotalcites of the general formula [M2+1?xM3+x(OH)2]x+[An?x/n.mH2O]x? where M2+ is a divalent cation, M3+ is a trivalent cation and An? is an organic anion selected from straight chain carboxylates of C16-C18 acids, carboxylates of aromatic acids, carboxylates of acrylic acid, unsaturated carboxylates of methacrylic acid and unsaturated carboxylates of vinylacetic acid are disclosed, along with methods of synthesis and uses.

Abstract: A spray drying process for preparing a solid catalyst and composition for use therein comprising a catalyst compound, an activator for the catalyst compound, and at least one compound selected from among siloxanes, polyalkylene glycols, C1-4 alkyl or phenyl ether or diether derivatives of polyalkylene glycols, and crown ethers, and optionally a filler or support.

Abstract: This invention relates to metallocene compositions and their use in the preparation of catalyst systems for olefin polymerization, particularly propylene polymerization. The metallocene compositions may be represented by the formula: wherein R3 are identical or different and are each a halogen atom, a C1-C10 alkyl group which may be halogenated, a C6-C10 aryl group which may be halogenated, a C2-C10 alkenyl group, a C7-C40-arylalkyl group, a C7-C40 alkylaryl group, a C8-C40 arylalkenyl group, a —NR?2, —SR?, —OR?, —OSiR?3 or —PR?2 radical, wherein R? is one of a halogen atom, a C1-C10 alkyl group, or a C6-C10 aryl group, and R9 and R11 are identical or different and are a Group 14 radical having from 1 to 20 carbon atoms or are each primary, secondary or tertiary butyl groups, aryl groups, isopropyl groups, fluoroalkyl groups, trialkyl silyl groups, or other groups of similar size.

Abstract: Compositions containing aluminum trisalkylacetoacetate compounds and glycol ether and to a method for the production and use thereof, particularly as printing ink additives.

Abstract: The present invention relates to a process of producing a fluorided catalyst compound, catalyst compositions, and polymerization methods including such. At least one specific embodiment of the invention includes contacting a chlorinated metallocene catalyst component with a fluorinated inorganic salt, for a time sufficient to form a fluorinated metallocene catalyst component such as described in the following example: wherein R are substituent groups selected from the group consisting of C1 to C10 alkyls in a particular embodiment, and p is 0 or an integer from 1 to 5. The fluorinated inorganic salt is characterized in a particular embodiment as a compound that provides at least one fluoride ion when contacted with a diluent comprising at least 50 wt % water.

Abstract: Process for the polymerization of olefins comprising contacting olefins under polymerization conditions in the presence of a catalyst system comprising the product obtained by contacting: (A) at least one transition metal organometallic compound, pyrolidyl bis(?-cyclopentadienyl)methylzirconium being excluded, and (B) an organometallic compound obtained by contacting: (a) a Lewis base having formula (I): ?wherein Ra, Rb, Rc and Rd, equal to or different from each other, are selected from the group consisting of hydrogen, halogen, linear or branched, saturated or unsaturated, C1-C10 alkyl, C6-C20 aryl, C7-C20 arylalkyl and C7-C20 alkylaryl groups; with b) a Lewis acid of formula (II) MtR13??(II) ?wherein Mt is a metal belonging to Group 13 of the Periodic Table of the Elements; R1, equal to or different from each other, are selected from the group consisting of halogen, halogenated C6-C20 aryl and halogenated C7-C20 alkylaryl groups; and (C) optionally an alkylating agent.

Abstract: A family of novel hetrocyclic-amide type catalyst precursors useful for the polymerization of olefins, such as ethylene, higher alpha-olefins, dienes, and mixtures thereof.

Abstract: Supported metallocene catalysts and processes for the use of such catalysts in isotactic polymerization of a C3+ ethylenically unsaturated monomer. The supported catalysts comprise a particulate silica support, an alkyl alumoxane component, and a metallocene catalyst component. The support has an average particle size of 10-50 microns, a surface area of 200-800 m2/g and a pore volume of 0.9-2.1 milliliters per gram (ml/g). Alumoxane is incorporated onto the support to provide a weight ratio of alumoxane to silica of at least 0.8:1.

Abstract: Epoxides, aziridines, thiiranes, oxetanes, lactones, lactams and analogous compounds are reacted with carbon monoxide in the presence of a catalytically effective amount of catalyst having the general formula [Lewis acid]z+{[QM(CO)x]w?}y where Q is any ligand and need not be present, M is a transition metal selected from the group consisting of Groups 4, 5, 6, 7, 8, 9 and 10 of the periodic table of elements, z is the valence of the Lewis acid and ranges from 1 to 6, w is the charge of the metal carbonyl and ranges from 1 to 4 and y is a number such that w times y equals z, and x is a number such as to provide a stable anionic metal carbonyl for {[QM(CO)x]w?}y and ranges from 1 to 9 and typically from 1 to 4.

Abstract: Synthetic hydrotalcites of the general formula [M2+1-xM3+x(OH)2]x+[An?x/n·mH2O]x? where M2+ is a divalent cation, M3+ is a trivalent cation and An? is an organic anion selected from straight chain carboxylates of C16-C18 acids, carboxylates of aromatic acids, carboxylates of acrylic acid, unsaturated carboxylates of methacrylic acid, unsaturated carboxylates of vinylacetic acid and C2 and higher organic acids containing heteroatoms such as nitrogen, phosphorous, sulfur and halogens are disclosed, along with methods of synthesis and uses.

Abstract: A composite metal polybasic salt containing a trivalent metal, zinc metal and a divalent metal as metal components and having a novel crystal structure, and a method of preparing the same. The invention further deals with a composite metal polybasic salt which has anion-exchanging property, which by itself is useful as an anion-exchanger, capable of introducing anions suited for the use upon anion-exchange, and finds a wide range of applications, and a method of preparing the same. The composite metal polybasic salt has a particular chemical composition and X-ray diffraction peaks, exhibiting peaks at 2&thgr;=2 to 15°, 2&thgr;=19.5 to 24° and 2&thgr;=33 to 50°, and a single peak at 2&thgr;=60 to 64° in the X-ray diffraction (Cu-&agr;).

Abstract: A method for making a solid catalyst component for use in a Ziegler-Natta catalyst includes combining a porous particulate support with a magnesium source in a hydrocarbon solvent to form a mixture, the magnesium source including a hydrocarbon soluble organomagnesium compound and a hydrocarbon insoluble anhydrous inorganic magnesium-halogen compound. The organomagnesium compound is halogenated and the mixture is reacted with a titanium compound or vanadium compound to form the solid catalyst component. The solid catalyst component is then recovered and combined with an organoaluminum cocatalyst to form a Ziegler-Natta catalyst which is advantageously used for the polymerization of olefins, particularly alk-1-enes such as ethylene, propylene, 1-butene, and the like. The catalyst can optionally include internal and external electron donors.

Abstract: This invention relates to metallocene compositions and their use in the preparation of catalyst systems for olefin polymerization, particularly propylene polymerization. The metallocene compositions may be represented by the formula: wherein R9 and R11 are identical or different and are a Group 14 radical having from 1 to 20 carbon atoms or are each primary, secondary or tertiary butyl groups, aryl groups, isopropyl groups, fluoroalkyl groups, trialkyl silyl groups, or other groups of similar size.

Abstract: This invention is directed to a group of novel homologous eight membered ring compounds having a metal, such as copper, reversibly bound in the ring and containing carbon, nitrogen, silicon and/or other metals. A structural representation of the compounds of this invention is shown below: wherein M and M′ are each a metal such as Cu, Ag, Au and Ir; X and X′ can be N or O; Y and Y′ can be Si, C; Sn, Ge, Al, or B; and Z and Z′ can be C, N, or O. Substituents represented by R1, R2, R3, R4, R5, R6, R1′, R2′, R3′, R4′, R5′, and R6′ will vary depending on the ring atom to which they are attached. This invention is also directed to depositing metal and metal-containing films on a substrate, under ALD or CVD conditions, using the above novel compounds as precursors.

Abstract: Surprisingly stable olefin polymerization co-catalysts formed from hydroxyaluminoxanes are revealed. In one embodiment of the invention, a solid composition of matter is formed from a hydroxyaluminoxane and a treating agent, whereby the rate of OH-decay for the solid composition is reduced as compared to that of the hydroxyaluminoxane. Processes for converting a hydroxyaluminoxane into a such a solid composition of matter, supported catalysts formed from such solid compositions of matter, as well as methods of their use, are described.

Abstract: Supported metallocene catalysts and processes for the use of such catalysts in isotactic polymerization of a C3+ethylenically unsaturated monomer. The supported catalysts comprise a particulate silica support, an alkyl alumoxane component, and a metallocene catalyst component. The support has an average particle size of 10-50 microns, a surface area of 200-800 m2/g and a pore volume of 0.9-2.1 milliliters per gram (ml/g). Alumoxane is incorporated onto the support to provide a weight ratio of alumoxane to silica of at least 0.8:1.

Abstract: Use of metallocene catalyst component for the preparation of a syndiotactic polyolefin having a monomer length of up to C10, which component has the general formula: R″(CpR1R2)(Cp′R1′R2′)MQ2 wherein Cp is a cyclopentadienyl ring; Cp′ is a 3,6 disubstituted fluorenyl ring; R1 and R2 are each independently H or a substituent on the cyclopentadienyl ring which is proximal to the bridge, which proximal substituent is linear hydrocarbyl of from 1 to 20 carbon atoms or a group of the formula XR*3 containing up to 7 carbon atoms in which X is chosen from Group IVA, and R* is the same or different and chosen from hydrogen or alkyl; R1′ and R2′ are each independently substituent groups on the fluorenyl ring, each of which is a group of the formula AR′″3, in which A is chosen from Group IVA, and each R′″ is independently hydrogen or a hydrocarbyl having 1 to 20 carbon atoms; M is a Group IVB transition metal or vanadium; each Q is hydrocarbyl having 1 to

Abstract: A particulate, modified chromium oxide catalyst for the polymerisation of ethylene or ethylene with &agr;-olefins, comprising: a) a chromium-oxide catalyst, b) a transition metal compound, and c) a catalyst activator. A method for the preparation of the catalyst comprises the steps of: a) subjecting a chromium oxide catalyst precursor, which comprises a chromium oxide compound combined with an inorganic support, to a temperature in the range of from 400 to 950° C.

Abstract: The present invention provides an improved acyclic anionic six-electron-donor ancillary ligand suitable for being bonded in a transition metal complex. The present invention also provides a transition metal complex that includes at least one acyclic anionic six-electron-donor ancillary ligand which is suitable for use as an olefin polymerization catalyst. The complex includes a Group 3 to 10 transition or lanthanide metal and one or more anionic or neutral ligands in an amount that satisfies the valency of the metal such that the complex has a net zero charge. The present invention also discloses a method for making transition metal complex and a method for using the complex for olefin polymerization.

Abstract: In metallocene complexes of a metal of transition group IV, V or VI of the Periodic Table, at least one substituted or unsubstituted cyclopentadienyl radical is bound to an element of group III of the Periodic Table which is in turn a constituent of a bridge between this cyclopentadienyl radical and the metal atom and bears an organonitrogen, organophosphorus or organosulfur group as sole further substituent.

Abstract: The present invention relates to the use of boron and aluminum compounds in electronics, in particular as electron transport material, as host material of the emission layer and as hole blocking material, in each case in phosphorescent OLEDs, and also to layers produced therefrom in phosphorescent OLEDs.

Abstract: Dicationic or partially dicationic Group 4 metal compounds having utility has addition polymerization catalysts among other uses and a method of preparation.

Abstract: The present invention relates to compounds in which a transition metal is complexed with two ligand systems and the two systems are reversibly bonded together by at least one bridge consisting of a donor and an acceptor, at least one substituent on the acceptor group being a fluorinated aryl radical, to the use of these compounds as catalysts and to a process for the polymerization of olefins.

Abstract: An organometallic compound obtainable by contacting a) a compound having the following formula (I): wherein Ra, Rb, Rc and Rd equal to or different from each other are hydrocarbon groups b) a Lewis acid of formula (II) MtR13   (II) wherein Mt is a metal belonging to Group 13 of the Periodic Table of the Elements (IUPAC); R1, equal to or different from each other, are selected from the group consisting of halogen, halogenated C6-C20 aryl and halogenated C7-C20 alkylaryl groups; two R1 groups can also form with the metal Mt one condensed ring. These compounds are useful as cocatalysts for polymerizing olefins.

Abstract: Described are catalyst systems having aluminium alkyl complexes of the formula (I) described herein applied to magnesium chloride, SiO2 or SiO2 in combination with MgCl2 as support in the presence of titanium halides or vanadium halides and internal and, if desired, external donors act both as cocatalysts and as stereoselectivity promoters in heterogeneous polymerizations of &agr;-olefins. Also described are polymerization methods using these catalyst systems.

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