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

Abstract: Described are methods of preparing organometallic complexes, including cyclopentadienyliron (II) arene complexes.

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: A compound useful as a catalyst or as a cocatalyst in combination with a Group 3-10 metal for addition polymerizations corresponding to the formula: [M′Q12L′I′]+(Arf3MQ2)— wherein: M′ is aluminum, gallium, or indium.

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: 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: Penta-coordinated ruthenium or osmium catalysts for metathesis reactions of olefins, which are cationic complexes represented by formulas I, II or III: wherein M is ruthenium or osmium; each of X1 and X2, which may be the same or different, is an optionally substituted C3-C20 hydrocarbon group having an allyl moiety as an end group bonded to the central metal atom M, or X1 and X2 together form a group, optionally substituted, which results from dimerization of an alkene and has at each end an allyl moiety bonded to the central metal atom M, L1 is a neutral electron donor ligand; L2 is a carbene group; L3 is a neutral electron donor ligand which may be the same as or different from L1, or L3 is a halide group; L11 is a neutral electron donor ligand; L12 is a solvent molecule capable of coordination to the central metal atom M; L13 is an alkyl group; L14 is an alkyl, a carbene, a solvent molecule capable of coordination to the central metal atom M, or a halide; L{circumflex over ( )}L is a bid

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 ferroceneylphosphine ligand and complexes prepared therefrom for homogeneous catalytic enantioselective hydrogenation, the ligand having the formula (I): Another aspect of the invention is directed to a ferroceneylphosphine ligand of formula (II),

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

Abstract: Novel aminomethylphosphine ligands have particular substituents on the central carbon atom. Such ligands form coordination complexes that may be catalysts for the polymerization of monomers or other catalytic induced reactions.

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: The present invention relates to novel onium gallates or gallates of organometallic compounds and polymerizable compositions containing the same. The onium gallates include an anionic gallate moiety and a cationic moiety. The anionic gallate moiety has the formulaGaX.sub.a R.sub.b.sup.-in which X is a halogen or a hydroxy group, R is an aryl group, a and b represent integers ranging from 0 to 4 and the sum of a and b is 4. The cationic moiety is selected from the group consisting of iodonium, pyrylium, thiapyrylium, sulphonium, phosphonium, ferrocenium, and diazonium ions. The novel onium gallates are useful as cationic initiators of polymerization.

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: A novel organometallic compound of formula M[(.mu.-OR').sub.2 M'R.sub.2 ].sub.2 can be vaporized at a low temperature and advantageously employed in the CVD of a heterometallic oxide film of the MM'.sub.2 O.sub.4 type, wherein M is a divalent element such as Be, Mg, Zn or Cd; M' is a Group 13 element such as Al or Ga; and R and R' are each independently a C.sub.1-10 alkyl group, with the proviso that if M is Mg, M' is not Al.

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 invention relates to chiral ferrocenyls of formula (I) ##STR1## wherein R.sub.a is --P(R.sub.10 R.sub.11) or --SR.sub.12 ;R.sub.b is --P(R'.sub.10 R'.sub.11), --SR'.sub.12, --CH.dbd.NR.sub.12, --CH.sub.2 --NH--R.sub.12 or --CH.sub.2 --O--P(R.sub.10 R.sub.11); and the other substituents are as defined in claim 1,which may be used as ligands for transition metal catalysts in enantioselective reactions.

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: The present invention provides methods for the preparation of compounds of the formula (Formula I):L.sub.y M(CO).sub.zwherein M is Ru or Os, each L is independently a neutral ligand, y=1-4, and z=1-5. These methods involve the reaction of Ru.sub.3 (CO).sub.12 or Os.sub.3 (CO).sub.12 with a neutral ligand in a solvent system having a boiling point higher than that of benzene at atmospheric pressure.

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: 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: The present invention is directed to a zinc-molybdenum-based dithiocarbamate derivative which is a complex salt having the metallic components of zinc and molybdenum in the same molecule. When used as a lubricant additive, it imparts a notable friction-reducing effect to the lubricant composition in which it is incorporated, reducing its friction coefficient and improving its stability of friction coefficient at both low and high temperature, particularly at high temperature. In particular, it improves friction-related characteristics much more notably than a combination of a molybdenum and zinc compound.

Abstract: The present invention relates to a new bimetallic complex catalyst system having the empirical formula of M.sup.1.sub.a M.sup.2.sub.b X.sub.m (L.sub.1).sub.n, wherein M.sup.1 is Rh or Ru, M.sup.2 is Ru or a lanthanide, when M.sup.1 is Rh, M.sup.2 is Ru or a lanthanide; when M.sup.1 is Ru, M.sup.2 is a lanthanide; X is H, Cl, Br or the combinations thereof; L.sub.1 is the ligand to the metal salt; 1.ltoreq.a.ltoreq.4; 1.ltoreq.b.ltoreq.2; 3.ltoreq.m.ltoreq.6; 6.ltoreq.n.ltoreq.15. The present invention also relates to a corresponding improved process for the hydrogenation of unsaturated copolymers, particularly NBR type rubber, wherein the above mentioned new bimetallic complex catalyst system is used.

Abstract: Mixed oxide vanadium/antimony/titanium ammoxidation catalysts, particularly suited for the ammoxidation of alkanes and exhibiting X-ray diffraction spectra which are characteristic of a crystallographic phase of rutile TiO.sub.2, are prepared by (a) dissolving respective soluble compounds of vanadium, of antimony and of titanium in at least one saturated alcohol, (b) contacting the alcoholic solution thus obtained with water and precipitating the mixed oxide therefrom, and (c) separating and calcining the mixed oxide thus precipitated.

Abstract: Novel one-source compounds for producing (Ba,Sr)TiO.sub.3 films having high dielectric constants and ferroelectric (Sr,Ba)Nb.sub.2 O.sub.6 films by the CVD method, which are in the form of a liquid at the source temperature and contain Ba and Sr at a specified ratio; processes for producing these novel compounds; and processes for producing films by using the same.Because of having a melting point of 160.degree. C., being in the form of a liquid and having enough vapor pressure at 200.degree. C., the novel compounds barium strontium .beta.-diketonate [Ba.sub.2 Sr(dpm).sub.6 and BaSr.sub.2 (dpm).sub.6 ] can be quantitatively supplied by gas bubbling as a feedstock in the CVD method while maintaining the Ba/Sr ratio at a constant ratio. Thus, barium strontium-containing oxide dielectric films can be produced at a high reproducibility by thermal decomposition on a substrate in an oxidative atmosphere. These compounds can be produced by reacting dpmh with Ba and Sr, Ba(dpm).sub.2 with Sr(dpm).sub.

Abstract: Novel aminomethylphosphine ligands have particular substituents on the central carbon atom. Such ligands form coordination complexes that may be catalysts for the polymerization of monomers or other catalytic induced reactions.

Abstract: This invention relates to a process for polymerizing ethylene comprising contacting ethylene and optional comonomers with a catalyst system comprising an activator and a transition metal compound represented by the formula: ##STR1## Wherein R.sub.1 and R2 are independently hydrogen or a group having up to 100 carbon atoms, Cp.sub.1 is a bulky ligand; Cp.sub.2 is a bulky ligand or a heteroatom optionally bound to a C.sub.1 to C.sub.50 hydrocarbyl group, n is the valence state of the transition metal, Tm is a Group 3 to 10 metal, and each X is independently an anionic leaving group.

Abstract: The present invention provides: a composition of the formula M.sup.+x (Ga(Y).sub.4.sup.-).sub.x where M is a metal selected from the group consisting of lithium, sodium, potassium, cesium, calcium, strontium, thallium, and silver, x is an integer selected from the group consisting of 1 or 2, each Y is a ligand selected from the group consisting of aryl, alkyl, hydride and halide with the proviso that at least one Y is a ligand selected from the group consisting of aryl, alkyl and halide; a composition of the formula (R).sub.x Q.sup.+ Ga(Y).sub.4.sup.

Abstract: The invention is directed to manganese-containing polyoxometallates of the formula (1)(Q).sub.q (Mn.sub.p A.sub.a X.sub.x Y.sub.y M.sub.m O.sub.d Z.sub.z (H.sub.2 O).sub.b)cH.sub.2 O (1)where Q is one or more cations selected from the group consisting of H, Li, K, Na, Rb, Cs, Ca, Mg, Sr, Ba, Al, PR.sup.1 R.sup.2 R.sup.3 R.sup.4 and NR.sup.1 R.sup.2 R.sup.3 R.sup.4 where R.sup.1, R.sup.2, R.sup.3 and R.sup.4 =H or C.sub.1 -C.sub.20 -alkyl, C.sub.5 -C.sub.8 -cycloalkyl or aryl;Mn is manganese;A is a heterometal and is one or more transition metals from transition groups II to VIII apart from Zn, in particular Ru, V, Ti, Zr, Cr, Fe, Co, Cu, Sn, Ni, Re or Os;X is one or more elements selected from the group consisting of Ga, B, P, Si, Ge, As, F, Cl, Br and I;Y is Sb, S, Te, Se and Bi;M is one or more transition metals selected from the group consisting of Mo, W, Nb, Ta and V;Z is one or more anions selected from the group consisting of OH.sup.-, F.sup.-, Cl.sup.-, Br.sup.-, I.sup.-, N.sub.3.sup.-, NO.sub.3.sup.

Abstract: Tantalum and titanium source reagents are described, including tantalum amide and tantalum silicon nitride precursors for the deposition of tantalum nitride material on a substrate by processes such as chemical vapor deposition, assisted chemical vapor deposition, ion implantation, molecular beam epitaxy and rapid thermal processing. The precursors may be employed to form diffusion barrier layers on microlectronic device structures enabling the use of copper metallization and ferroelectric thin films in device construction.

Abstract: A practical and scalable process for the synthesis of constrained geometry metallocene catalyst is described.

Abstract: Compounds of formulae I: (DIP)IrX.sub.q Y.sub.r (Z), Ia: (DIP)IrX.sub.s Y.sub.t (Z).sub.2 and Ib: (DIP)Ir(Z).sub.3 or mixtures of at least two of those compounds, wherein DIP is a ditertiary diphosphine, the two phosphine groups of which are bonded to a C.sub.2 -, C.sub.3 - or C.sub.4 -carbon chain, with the result that the diphosphine forms a 5- to 7-membered ring together with the Ir atom, X is Cl, Br or I, Y is a hydrogen atom, q and r are 0, 1 or 2 and the sum of q+r is 2, s and t are 0 or 1 and the sum of s+t is 1, and Z is the anion of an organic oxy acid that contains a group C(.dbd.O), S(.dbd.O)O or P(.dbd.O)O in the anion. The compounds are excellent catalysts for the hydrogenation of imines, especially for the enantioselective hydrogenation of prochiral imines.

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

Abstract: A novel organometallic compound of formula M[(.mu.-OR').sub.2 M'R.sub.2 ].sub.2 can be vaporized at a low temperature and advantageously employed in the CVD of a heterometallic oxide film of the MM'.sub.2 O.sub.4 type, wherein M is a divalent element such as Be, Mg, Zn or Cd; M' is a Group 13 element such as Al or Ga; and R and R' are each independently a C.sub.1-10, alkyl group, with the proviso that if M is Mg, M' is not Al.

Abstract: A method for producing a bridged type transition metal complex represented by the following formula (1), comprising the following steps (i) and (ii):step (i); a step for reacting a specific cyclopentadiene compound with an organic alkaline metal compound or an organomagnesium compound to produce an alkaline metal salt compound or a magnesium salt compound of the cyclopentadiene compound; andstep (ii); a step for reacting the alkaline metal salt compound or magnesium salt compound of the cyclopentadiene compound with a specific transition metal compound, wherein at least the step (ii) is performed in the presence of an amine compound.According to the present invention, there can be provided a method for producing a bridged type transition metal complex having one cyclopentadiene type anion skeleton on an industrial scale in high yield without requiring an industrially disadvantageous low temperature and replacement of the solvent, which is capable of reducing the number of the steps.

Abstract: The present invention provides methods for the preparation of compounds of the formula (Formula I):L.sub.y M(CO).sub.zwherein M is Ru or Os, each L is independently a neutral ligand, y=1-4, and z=1-5. These methods involve the reaction of Ru.sub.3 (CO).sub.12 or Os.sub.3 (CO).sub.12 with a neutral ligand in a solvent system having a boiling point higher than that of benzene at atmospheric pressure.

Abstract: Metallocene complexes of a metal M selected from titanium, zirconium and hafnium, comprising at least one anionic group A containing an .eta..sup.5 -cyclopentadienyl ring co-ordinated with the metal M, wherein the anionic group is substituted in at least one position of the cyclopentadienyl ring with a radical having the formula:Ph*--(CR.sup.6 R.sup.7).sub.nwherein: R.sup.6 and R.sup.7 are independently hydrogen, halogen or a C.sub.1 -C.sub.4 alkyl group, preferably hydrogen, "n" is 0 or 1, preferably 1, Ph* is a C.sub.6 -C.sub.14 group comprising an aromatic ring linked to --CR.sup.6 R.sup.7 -- or to A and substituted with at least one and up to a maximum of three electron-attractor groups, on the condition that, when A is an .eta..sup.5 -indenyl group and "n" is 0, at least one Ph group is linked to A in position 1 or 3 of indenyl.These complexes can be used in (co)polymerization processes of .alpha.

Abstract: An x-ray contrast medium containing a multinuclear complex of the formula (M.sub.6 (.mu..sub.3 B).sub.8 A.sub.v).sub.x L.sub.w, wherein M is Mo, W, Re Tc, V, Nb, Ta, Ru, or Fe; .mu..sub.3 B represent a tridentate bridging atom; A is a non-bridging atom; L is a ligand coordinately bonded to at least one M atom; x is a positive integer; and v and w are independently zero or positive integers.

Abstract: The invention relates to a process for the preparation of a compound of the formula IV or IVa ##STR1## in which R.sup.1 -R.sup.5 are preferably hydrogen or alkyl, which comprises reacting a compound I ##STR2## with a compound II ##STR3## in which X.sup.1 and X.sup.2 are preferably halogen, to give the corresponding indanones, which are converted into the compounds IV and IVa by reduction and dehydration. The compounds IV and IVa are important intermediate products for the preparation of chiral metallocene complexes which are suitable catalyst components for olefin polymerization.

Abstract: A method is provided for preparing organic hydroperoxides by oxidizing aryl alkyl hydrocarbons having a benzylic hydrogen with an oxygen containing gas using as a catalyst an oxo (hydroxo) bridged tetranuclear metal complex having a mixed metal core, one metal of the core being a divalent metal selected from Zn, Cu Fe, Co, Ni, Mn or mixtures thereof and another metal being a trivalent metal selected from In, Fe, Mn, Ga, and Al.

Abstract: Chiral compounds of the formula I ##STR1## where the variables are as described in the specification.

Abstract: Metallocene complexes of the formula I ##STR1## where M is titanium, zirconium, hafnium, vanadium, niobium or tantalum,n is an integer from 0 to 10,R.sup.5 is ##STR2## R.sup.11 to R.sup.14 are as designated in the disclosure, n.sup.1 is an integer from 0 to 10,X.sup.1 to X.sup.4 are each fluorine, chlorine, bromine, iodine, hydrogen, C.sub.1 -C.sub.10 -alkyl, C.sub.6 -C.sub.15 -aryl, alkylaryl having 1 to 10 carbon atoms in the alkyl radical and 6 to 20 carbon atoms in the aryl radical, --OR.sup.15 --, --NR.sup.15 R.sup.16 or ##STR3## R.sup.15 to R.sup.21 are as designated in the disclosure, and o, p, q, r are each an integer from 0 to 4, the sum o+p+q+r+1 corresponding to the valency of M,which were used as active catalyst components in the preparation of polymers of C.sub.2 -C.sub.10 -alkenes, are recovered by a process wherein the polymerization is stopped by adding an acid and the metallocene complexes of the formula I are recovered by extraction from the reaction mixture.

Abstract: The conversion of the achiral meso form of an ansa-metallocene complex into the chiral rac form is carried out photochemically in the presence of a chiral auxiliary reagent.

Abstract: The present invention relates to a process for preparing racemic ansa-metallocene complexes I ##STR1## tin compounds II ##STR2## and a process for preparing tin compounds II. R.sup.1 to R.sup.9, M, and X are defined herein.

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: Metal complexes useful as olefin polymerization catalysts corresponding to the formula: ##STR1## or a dimer, solvated adduct, chelated derivative or mixture thereof, wherein:Q is a cyclic group or Y*, that is bound to M by means of a delocalized .pi.-bond, said group containing up to 50 nonhydrogen atoms;M is a metal of Group 3, 4 or the Lanthanide series of the Periodic Table of the Elements;Z is a covalently bound, divalent substituent of up to 50 non-hydrogen atoms having the formula, --(ER.sub.2).sub.m --, wherein E independently each occurrence is carbon, silicon or germanium, R independently each occurrence is selected from the group consisting of hydrocarbyl, hydrocarbyloxy, silyl, and germyl of up to 20 atoms other than hydrogen, and m is an integer from 1 to 3;Y* is an allyl or a hydrocarbyl-, silyl- or germyl-substituted allyl group containing up to 20 nonhydrogen atoms bonded to Z and bonded via an .eta..sup.3 -.pi.

Abstract: The present invention relates to a stereorigid metallocene compound which has as ligands at least two substituted or unsubstituted cyclopentadienyl groups which are connected to one another via a five-membered ring, where at least one cyclopentadienyl group is fuzed to the five-membered ring and the ligand system of the stereorigid metallocene compound is different from 4-?(.eta..sup.5 -3'-alkyl-cyclopentadienyl)-4,6,6-trimethyl-(.eta..sup.5 -2-alkyl-4,5-tetrahydropentalene)!. The metallocene compound of the invention is suitable as a catalyst component for olefin polymerization.