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 specific amount of a low molecular weight vinyl siloxane is blended with a platinum-vinyl siloxane complex to provide a platinum complex catalyst, which is prevented from deterioration with time at elevated temperatures and from blackening and precipitation, and maintains its catalytic activity unaffected.

Abstract: The present invention relates to silica gel supported bis-cinchona alkaloid compounds of the formula: ##STR1## wherein Q is dihydroquininyl or dihydroquinindinyl; X is a compound having 4 carbon atoms; and R is methoxy, ethoxy or methyl; and methods of preparation and use thereof. The silica gel supported bis-cinchona alkaloid derivatives of this invention are useful re-useable catalysts for preparing vicinal diols by asymmetric dihydroxylation of olefins.

Abstract: The present invention provides a hydroformylation process comprising: (1) forming a reaction mixture containing: (a) an olefinic compound, (b) hydrogen, (c) carbon monoxide, (d) a phosphite in which each phosphorus atom is bonded to three oxygen atoms and at least one such oxygen atom is bonded to a carbon atom of an aromatic ring that is adjacent to another carbon atom of said ring having a pendant monovalent group having a steric hindrance at least as great as the steric hindrance of the isopropyl group, (e) a catalytic amount of rhodium, and (f) a Group VIII metal (other than a rhodium) in an amount sufficient to reduce the rhodium-catalyzed decomposition of the phosphite during the hydroformylation process; and (2) maintaining the reaction mixture under conditions at which the olefinic compound reacts with the hydrogen and carbon monoxide to form an aldehyde.

Abstract: A catalyst/cross-linking agent composition, containing at least onea) vinyltrialkoxysilane as cross-linking agent,b) dialkyltin oxide as catalyst,c) optional organic acid for the control of the reaction time,d) optional inert solvent, ande) optional dye or colored pigment,is especially useful for condensation/cross-linking of polysiloxanes, such as OH-endstopped polydimethylsiloxane, in making moldings. Especially useful for impression taking in the dental field.

Abstract: Porous microcomposites comprising a perfluorinated ion-exchange polymer (PFIEP) containing pendant metal cation exchanged sulfonate groups, metal cation exchanged carboxylate groups, or metal cation exchanged sulfonate and carboxylate groups, wherein the metal cation may be ligand coordinated, and optionally pendant sulfonic acid groups, carboxylic acid groups, or sulfonic acid and carboxylic acid groups, the PFIEP being entrapped within and highly dispersed throughout a network of metal oxide, a network of silica or a network of metal oxide and silica can be prepared from PFIEP and one or more precursors selected from the group consisting of a metal oxide precursor, a silica precursor, and a metal oxide and silica precursor using an in situ process. Preferred metal cations are Cr, Sn, Al, Fe, Os, Co, Zn, Hg, Li, Na, Cu, Pd or Ru. Such microcomposites have a first set of pores having a pore size diameter ranging from about 0.

Abstract: An catalyst composition for preparing high-syndiotacticity polystyrene polymers which comprises: (a) a titanium complex represented by the following formula of TiR'.sub.1 R'.sub.2 R'.sub.3 R'.sub.4 or TiR'.sub.1 R'.sub.2 R'.sub.3, wherein R'.sub.1, R'.sub.2, R'.sub.3, and R'.sub.4 are, independently, an alkyl group, an aryl group, an alkoxy group, an aryloxy group, an amino group, a hydrogen atom, or a halogen atom; (b) a cyclopentadienyl complex of silicon (Si), germanium (Ge), or tin (Sn) represented by the following formula: ##STR1## wherein R.sub.1, R.sub.2, R.sub.3, R.sub.4 and R.sub.

Abstract: A catalyst enables hydrosilylation of aliphatically unsaturated carbon-carbon bonds by silicon-bonded hydrogen to be conducted rapidly in water. The catalyst provides a rapid method of carrying out hydrosilylation in water. An emulsion form of catalyst includes a dispersion in water of liquid catalyst, the main component of which is a platinum and alkenylsiloxane complex. The volumetric average particle size of liquid catalyst dispersed is less than or equal to 1 .mu.m. Hydrosilylation of an aliphatically unsaturated carbon-carbon bond by silicon-bonded hydrogen is carried out in water using the catalyst.

Abstract: The present invention provides a catalyst system that exhibits unprecedented catalyst efficiencies and control of desired properties in the polymer product. The catalyst system includes a new generation titanium catalyst in combination with an electron donor described by the formula: ##STR1## wherein R.sub.1 is an alkyl group containing a primary carbon atom attached to the silicon atom; R.sub.2 and R.sub.3 are alkyl or aryl groups; and R.sub.4 is an alkyl group with a primary carbon atom attached to the silicon atom; R.sub.1 and R.sub.4 are the same or different. R.sub.1 and R.sub.4 are preferably chosen from the group consisting of n-propyl, n-butyl and methyl; most preferably n-propyl and n-butyl with R.sub.1 and R.sub.4 being the same or, alternatively, most preferably, R.sub.1 is methyl and R.sub.4 is C.sub.3 or higher. The system has a catalyst efficiency of over 30 kg/g-cat.multidot.h as the Si/Ti mole ratio varies from 4-20 in the system. The system easily achieves efficiencies over 30 kg/g-cat.

Abstract: Ionic compounds represented by general formula (I), method of their production, olefin polymerization catalyst components, and olefin polymerization catalysts containing the components are provided.?M(R.sup.1).sub.k (R.sup.2).sub.1 (R.sup.3).sub.m (R.sup.4 -L).sub.n !.sup.- ?D!.sup.+ (I)(wherein, M is an element belonging to the Group 13; R.sup.1, R.sup.2 and R.sup.3 are pentafluorophenyl, etc., R.sup.4 is a substituted phenylene group, etc., k, l and m being each 0 or an integer of 1 to 3, and n being an integer of 1 to 4 such that k+l+m+n=4; L is trichlorosilyl, methyldichlorosilyl, dimethylchlorosilyl group, etc.; and D is a monovalent cation).

Abstract: A catalyst precursor of the formula: ##STR1## wherein: R.sup.1 is a cycloalkadienyl ligand;R.sup.2, R.sup.3, R.sup.4, and R.sup.5 are independently hydrogen, a hydrocarbyl group containing 1 to 20 carbon atoms, or a silyl group, and may be connected to R.sup.1 through a bridging group comprising at least two Group IVA atoms; with the proviso that one of R.sup.3, R.sup.4, and R.sup.5 is a negative charge stabilizing group selected from the group consisting of Group IVA trialkyl groups, aryl groups, heteroaromatic groups, ethylenically unsaturated hydrocarbon groups, acetylenically unsaturated hydrocarbon groups, ketonic groups, and aromatic organometallic moieties, is provided. When combined with a compound comprising a metal from Groups IIIB to VIII or the Lanthanide series of the Periodic Table of elements and an activating cocatalyst, the catalyst precursor is useful for the polymerization of olefins.

Abstract: A solid catalyst component for the polymerization and copolymerization of ethylene and alpha- olefins, containing a metallocene supported on an inorganic solid carrier constituted by a porous silicon oxide, the supported metallocene having the formula (I): ##STR1## wherein M is a group of metal, R' and R" are dialkylamide groups, R'" has the same definition as R' or is a cyclopentadienyl consisting ligand, and A is an anion containing an .eta..sup.5 -cyclopentadienyl ring coordinated to metal M, and wherein a carbon atom of the .eta..sup.5 -cyclopentadienyl ring of anion A is covalently bonded to the surface of the porous inorganic solid carrier.

Abstract: A cationic metallocene complex with trisperfluorobiphenyl borate for use as a polymerization catalyst.

Abstract: The invention relates to cobalt carbonyl catalysts of the formula (I) ##STR1## where R is --CH(CH.sub.2 OCH.sub.2 CH.sub.3).sub.2 or --C.sub.2 H.sub.4 (OCH.sub.2 CH.sub.2).sub.n OY, with n=1 to 12 and Y=H or CH.sub.3, and also a process for their preparation and their use as hydroformylation catalysts.

Abstract: An olefin polymerization catalyst component is represented by the general formula (1); ##STR1## wherein M is titanium, zirconium or hafnium; each of A and A' is the same or different and is a hydrocarbon or halogenated hydrocarbon having 1 to 50 carbon atoms, or a hydrocarbon or halogenated hydrocarbon group having 1 to 50 carbon atoms and a substituent containing an oxygen atom; E is a residual group of an element of the 13th to 15th Groups capable of forming three bonds; each of R and R' is the same or different and is a halogen atom or a hydrocarbon group having 1 to 20 carbon atoms; R" represents a hydrocarbon or halogenated hydrocarbon group containing at least one hetero atom and having 1 to 20 carbon atoms. This component is used in a catalyst to produce an olefin polymer.

Abstract: In the process for the production of acetic acid by carbonylation of methanol and/or a reactive derivative thereof the water concentration in the liquid reaction composition is maintained at a steady-state concentration by at least one process step selected from the group consisting of (i) recovery and disposing of water from at least part of the overhead process stream from the light ends column and (ii) replacing at least a portion of the methanol feed with a component selected from the group consisting of methyl acetate, dimethyl ether, acetic anhydride and mixtures thereof. The recovered aqueous effluent from this and other processes may be purified of carboxylic acid by reactive distillation with at least one C.sub.1 to C.sub.3 alcohol.

Abstract: A catalyst component is disclosed for use in the homo- or copolymerization of olefinic hydrocarbons. The catalyst component is comprised of a first compound of the formula M.sup.1 (OR.sup.1).sub.p R.sup.2.sub.q X.sup.1.sub.4-p-q, M.sup.1 being titanium a second compound of the formula M.sup.2 (OR.sup.3).sub.m R.sup.4.sub.n X.sup.2.sub.z-m-n, with M.sup.2 being a metal of Groups Ia-IIIa or IIb of the Periodic Table, and a third compound which is an organocyclic compound having two or more conjugated double bonds. A process is also disclosed for the production of hydrocarbon polymers in which the above catalyst component is combined with a modified organoaluminum compound to form a catalyst composition capable of providing controlled molecular weight, wide distribution thereof and other desirable qualities in the polymer product.

Abstract: Porous microcomposites comprising a perfluorinated ion-exchange polymer (PFIEP) containing pendant sulfonic acid and/or carboxylic acid groups entrapped within and highly dispersed throughout a network of metal oxide, a network of silica, or a network of metal oxide and silica are prepared from PFIEP and one or more precursors selected from the group consisting of a metal oxide precursor, a silica precursor, and a metal oxide and silica precursor using an in situ process. Such microcomposites have a first set of pores having a pore size diameter ranging from about 0.5 nm to about 75 nm and may further comprise a second set of pores having a diameter ranging from about 75 nm to about 1000 nm. These microcomposites possess high surface area and exhibit high catalytic activity for a variety of reactions including, but not limited to, nitrations, esterifications, dimerizations, alkylations, polymerizations, acylations, and isomerizations.

Abstract: The invention relates to a bidentate phosphine ligand, the phosphorus atoms of the phosphine being connected via a bridge group, the bridge group of the bidentate phosphine ligand consisting of an ortho-anellated annular system, comprising two aryl groups, which aryl groups are connected by two bridges, the first bridge consisting of an --O-- or an --S-- atom and the second bridge being a group that contains an oxygen, sulphur, nitrogen, silicon or carbon atom or a combination of these atoms, the two phosphorus atoms being connected to the two aryl groups of the bridge group at the ortho-position relative to the --O-- or --S-- atom of the first bridge.The invention also relates to the use of this bidentate phosphium ligand in a catalyst system comprising also a transition metal compound which is used in the following type of reactions: hydroformylation hydrogenation, hydrocyanation, polymerization, isomerisation, carboxylation, cross coupling and metathesis.

Abstract: A platinum catalyst containing (A) a platinum complex having a vinyl-containing organosiloxane ligand and (B) a vinyl-containing organopolysiloxane is prepared by mixing components (A) and (B) such that at least 2 mol of vinyl group in component (B) is available per mol of platinum atom in component (A) and heating the mixture at 40.degree.-100.degree. C. for at least 1 hour. When blended in an addition reaction curing type organosiloxane composition, the platinum catalyst has the advantage that even after long-term storage at elevated temperatures, it remains stable and active enough to cause the organosiloxane composition to cure.

Abstract: The present invention provides new catalyst formats which comprise a supported catalyst tethered to a second and different catalyst by a suitable tethering ligand. A preferred system comprises a heterogeneous supported metal catalyst tethered to a homogeneous catalyst. This combination of homogeneous and heterogeneous catalysts has a sufficient lifetime and unusually high catalytic activity in arene hydrogenations, and potentially many other reactions as well, including, but not limited to hydroformylation, hydrosilation, olefin oxidation, isomerization, hydrocyanation, olefin metathesis, olefin polymerization, carbonylation, enantioselective catalysis and photoduplication. These catalysts are easily separated from the products, and can be reused repeatedly, making these systems very economical.

Abstract: A microparticle catalyst for hydrosilylation reactions which contains microparticles of an average particle diameter of 0.1 to 20 .mu.m made of a metallic catalyst for hydrosilylation reactions; a disiloxane having the general formula (R.sup.1 R.sup.2 ArSi).sub.2 O, wherein, R.sup.1 is an alkenyl group, R.sup.2 is a monovalent hydrocarbon group and Ar is an aryl group; and a resin having a glass transition temperature of 40.degree. to 200.degree. C. and thermosetting silicone composition containing the microparticle catalyst.

Abstract: A non-supported solid catalyst comprising (a) an ionic compound comprising a.1) a cation and a.2) an anion having up to 100 nonhydrogen atoms and said anion containing at least one substituent comprising an active hydrogen moiety, (b) a transition metal compound, and (c) an organometal compound wherein the metal is selected from the Groups 1-14 of the Periodic Table of the Elements; a supported solid catalyst comprising (a), (b), (c), and (d) a support material, obtainable by combining components (a), (b), (c), and (d) in any order, and wherein during at least one step in the preparation of the solid catalyst, component (a) dissolved in a diluent in which (a) is soluble, is converted into solid form; a method for preparing the solid catalysts; and a process of polymerization using these solid catalysts.

Abstract: The invention relates to ferrocenyldiphosphine ligands containing a silylene group, ferrocenyldiphosphines bound to inorganic or polymeric organic supports by this silylene group, their preparation and also their metal complexes with transition metals such as rhodium or iridium. The invention also relates to the use of these complexes for hydrogenating 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 diphosphines and prochiral unsaturated compounds.

Abstract: According to the present invention, a catalyst is provided which is represented by the formula ?RC(YR').sub.2 !.sub.2 CrX, wherein R and R' are individually selected from the group consisting of carbyl and carbylsilyl groups; Y is N, C or P; and X is a halogen, halogen alkyl, Si, alkylsilyl or a carbyl group. Also provided is a process for preparing the catalyst and an oligomerization process employing the catalyst. The process produces linear alpha-olefins with low amounts of polymer, vinylidine and isomerized olefins.

Abstract: The invention relates to a catalyst for preparing organosiloxanes and polyorganosiloxanes which are obtained primarily by polycondensation processes. The catalyst of the invention is a reaction product of phosphonitrilic chloride with a compound of the general formula ?R.sub.3 SiO(R.sub.2 SiO).sub.m !.sub.3 P.dbd.O (I), where R are, independently of one another, identical or different, unsaturated and/or saturated monovalent hydrocarbon radicals having from 1 to 6 carbon atoms or hydrogen, with the proviso that only one hydrogen atom is bound to each silicon atom and m has a value between 0 and 1000. Volatile chlorine-containing silicon compounds formed during the reaction can, if required, be completely or partially removed.

Abstract: The present invention relates to a metallocene compound of the formula I which is suitable for olefin polymerization ##STR1## where M is a metal of group IVb, Vb or VIb of the Periodic Table.X are each a hydrogen atom, a halogen atom or a C.sub.1 -C.sub.40 -radical OR.sup.4 or NR.sup.4.sub.2, where R.sup.4 are a C.sub.1 -C.sub.20 hydrocarbon radicalm and p are 1, 2 or 3,n is 1 or 2,L each a .pi. ligand which coordinates to the central atom M,M.sup.2 are each a silicon atom, a germanium atom or a tin atom,R.sup.1 are a C.sub.1 -C.sub.20 -radical,R.sup.2 are a C.sub.1 -C.sub.20 -radical or a .pi. ligand which coordinates to the central atom M,A are each a bidentate C.sub.1 -C.sub.40 -hydrocarbon group,Z are each a boron atom, a silicon atom, a germanium atom or a tin atom,R.sup.3 are each a hydrogen atom or a C.sub.1 -C.sub.20 -radical,o is zero, 1 or 2,Hal are each a halogen atom, andwhere n is 1 if R.sup.2 is a .pi. ligand which coordinates to the central atom M and n is 2 if R.sup.2 is a C.sub.1 -C.sub.

Abstract: A novel titanium (III)-based .beta.-diketonate-coordinated compound is disclosed for catalyzing the polymerization reaction of syndiotactic polystyrenes. The titanium (III)-based compound is represented by the following formula 1: ##STR1## wherein X is a C.sub.1 .about.C.sub.12 alkoxy or amine group, or a halogen atom; R is a C.sub.1 .about.C.sub.12 alkyl, aryl, or alkylsilane group. Preferably, X is N(SiMe.sub.3).sub.2 -- or OMe--, and R is phenyl, methyl, or t-butyl. The titanium (III)-based compounds are prepared by reacting titanium trichloride with diketone and tetrahydrofuran to form an intermediate product, then reacting the intermediate product Ti(AcAc)Cl.sub.2 (THF).sub.2 with either aminosilane or alcohol.

Abstract: Disclosed is a supported catalyst which is the reaction product of(a) a silylamine polymer having the general formula ##STR1## where each R is independently selected from alkyl from C.sub.1 to C.sub.6 or aryl from C.sub.6 to C.sub.10, R.sub.1 is a divalent aliphatic or aromatic group from C.sub.2 to C.sub.20, "m" is 1 to about 100, and "n" is 2 to about 500, with(b) an organometallic compound having the general formulaQ--M--(X).sub.3where Q is a stabilizing ligand, each X is independently selected from halogen, alkyl from C.sub.1 to C.sub.6, or dialkylamino from C.sub.1 to C.sub.6, M is zirconium, titanium, or hafnium and M is bonded to a nitrogen in said silylamine polymer, and the ratio nitrogens bondable to M in said silylamine polymer to M atoms is 1:1 to 3:1.

Abstract: This invention relates to a conventional supported heterogeneous Ziegler-Natta catalyst for the polymerization of olefins. It has been found that adding a lithium compound to a transition metal catalyst component and then adding an organoaluminum co-catalyst and an organosilicon electron donor produces a catalyst which yields polymer with increased molecular weight. The lithium compound is of the general formula LiCp wherein Cp is a cyclopentadienyl or substituted cyclopentadienyl and is preferably lithium cyclopentadienide or lithium indene. Preferably, the molar ratio of lithium compound/transition metal is at least 0.2.

Abstract: The invention relates to an organometallic compound of the formula I, ##STR1## where M is a tetravalent metal, L are, independently of one another, identical or different and are each a .pi. ligand, T are, independently of one another, identical or different and are each a bridge and A are, independently of one another, identical or different and are each a .pi. ligand or another electron donor.

Abstract: Addition polymerization catalysts-comprising 1) a Group 4 metal complex in the .sup.+ 3 oxidation state containing two delocalized .pi.-bonding moieties, and a stabilizing ligand covalently bonded to the metal and also datively bonded to the metal via lone pair electrons of an amine, phosphine, ether or thioether group and 2) an activating cocatalyst.

Abstract: Catalyst compositions comprising metallocene complexes having polymerisable olefinic groups substituent on an organic group containing a cyclopentadienyl nucleus may be used for the preparation of polyolefins. The catalyst compositions may be in the form of polymers comprising the metallocene complex and may be suitably supported on inorganic supports. Polymers having a broad range of density and melt indices as well as low hexane extractables and excellent powder morphology and flowability may be obtained by use of the catalyst compositions. Preferred metallocene complexes are zirconium complexes in which the polymerisable olefinic group is vinyl.

Abstract: The invention relates to new transition metal compounds useful as olefin polymerization catalysts. They are characterized by the formula (V)(E)(W)M(L), which in which M is a transition metal, V, E, and W, is e.g.

Abstract: The invention relates to catalysts for the preparation and processing of polyorganosiloxanes, in particular for processing silicone resins, for example for solvent-free production of mica insulating materials. The catalysts are silanized organometallic compounds.

Abstract: Disclosed is a process for the preparation of bistriphenylsilyl chromate, wherein triphenylchlorosilane, potassium dichromate and any one selected from alkali metal oxides, alkali hydroxides and alkali metal carbonates are reacted in, as solvent, a mixture of glacial acetic acid and a hydrocarbon solvent at a certain temperature, whereby bistriphenylsilyl chromate having high purity can be obtained with high yield.

Abstract: A process for the polymerization of one or more conjugated dienes by means of a rare earth based catalyst in which the catalyst is formed by bringing together in liquid hydrocarbon medium in the presence of a small portion of conjugated diene: a) a rare earth salt, b) an organo aluminum and c) a silicon halide or organosilicon halide and aging the catalyst before contact with the conjugated diene(s) to be polymerized. This catalyst formation procedure offers the possibility of producing a diene polymer of high cis content with a narrower molecular weight distribution and/or smaller high molecular weight fraction which is reflected in improved processing characteristics and reduced viscosity in styrene.

Abstract: The invention relates to a process for preparing organosilanes which contain at least one Si-bonded hydrogen in the presence of a phosphonium catalyst, the phosphonium catalyst itself and also a process for its preparation.

Abstract: A vanadium-containing catalyst system particularly suited to the polymerization of olefin polymers. The catalyst system includes a supported, first catalyst component prepared by contacting silica with hexaalkyldisilazane and thereupon with (1) a compound or complex which includes at least one carbon to magnesium covalent bond and (2) a compound which includes at least one carbon to Group 13 metal covalent bond. The sequence of contact of the silica with compound or complex (1) and compound (2) is optional. However, unless the compound or complex (1) and the compound (2) contact the silica simultaneously, the product of this contact is next contacted with whichever of compound (1) or (2) does not initially contact the silica. The product of the step of contacting with compounds (1) and (2) is washed and then contacted with a vanadium compound which includes at least one halogen atom. Finally, the product of the vanadium compound contacting step is contacted with an alcohol.

Abstract: The present invention relates a process for stereoselective or regioselective chemical synthesis which generally comprises reacting a nucleophile and a chiral or prochiral cyclic substrate in the presence of a non-racemic chiral catalyst to produce a steroisomerically or regioselectively enriched product.

Abstract: A catalyst component useful in the polymerization of olefins which includes a support formed of a copolymer of an olefin and a silane monomer having at least one unsaturated hydrocaryl substitutent. A process for making the catalyst component as well as a catalyst composition which includes the catalyst component is also set forth.

Abstract: Double bound metallocenes, i.e. metallocenes having a cyclopentadienyl-containing radical that is bound to a transition metal both by a pi bond and by a sigma carbon bond of a substituent of that same cyclopentadienyl-containing radical can be prepared by reducing metallocenes having a cyclopentadienyl-containing radical having at least one an unsaturated substituent. Also a process for producing polymers comprising contacting at least one olefinic monomer under suitable polymerization conditions with such double bound metallocenes.

Abstract: An catalyst composition for preparing high-syndiotacticity polystyrene polymers which comprises: (a) a titanium complex represented by the following formula of TiR'.sub.1 R'.sub.2 R'.sub.3 R'.sub.4 or TiR'.sub.1 R'.sub.2 R'.sub.3, wherein R'.sub.1, R'.sub.2, R'.sub.3, and R'.sub.4 are, independently, an alkyl group, an aryl group, an alkoxy group, an aryloxy group, an amino group, a hydrogen atom, or a halogen atom; (b) a cyclopentadienyl complex of silicon (Si), germanium (Ge), or tin (Sn) represented by the following formula: ##STR1## wherein R.sub.1, R.sub.2, R.sub.3, and R.sub.

Abstract: Compounds useful as catalyst components for olefin polymerization. The compounds comprise derivatives of cyclopentadienyl complexes of the ZR or HF.

Abstract: A novel photoinitiator which includes an organometallic complex salt grafted onto a polyorganosiloxane skeleton is provided.

Abstract: The invention relates to ferrocenyldiphosphine ligands containing a silylene group, ferrocenyldiphosphines bound to inorganic or polymeric organic supports by this silylene group, their preparation and also their metal complexes with transition metals such as rhodium or iridium. The invention also relates to the use of these complexes for hydrogenating 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 diphosphines and prochiral unsaturated compounds.The preparation of these immobilized ferrocenyldiphosphines has only been made possible by the provision of correspondingly functionalized ferrocenyldiphosphines. These compounds and their preparation are likewise novel.Accordingly, the invention also provides compounds of the formula I ##STR1## in which R.sub.1 is C.sub.1 -C.sub.8 alkyl, phenyl or phenyl substituted by from 1 to 3 C.sub.1 -C.sub.4 alkyl or C.sub.1 -C.sub.

Abstract: Catalyst systems useful in addition polymerization reactions comprising a Group 4 metal complex and a silylium salt activating cocatalyst are prepared by contacting the metal complex with a silylium salt of a compatible, non-coordinating anion, optionally the silylium salt is prepared by electrochemical oxidation and splitting of the corresponding disilane compound.

Abstract: The invention relates to a catalyst for the epoxidation of alkenes using alkylhydroperoxide, the catalyst comprising an ion of one or more of the metals molybdenum, wolfram, titanium or vanadium on an inorganic carrier, characterised in that the metal ion is bound to the carrier via a polydentate organic ligand.The invention also relates to a process for the preparation of an alkene oxide by an alkene having 3 or more carbon atoms with an alkylhydroperoxide, using the catalyst described above.

Abstract: A process for preparing titanium or zirconium hydrocarbyloxide complexes in a reduced oxidation state comprising contacting the corresponding complex in an elevated oxidation state with lithium alkyl reducing agent and recovering the resulting product.

Abstract: A method is provided for forming a supported cyclopentadiene-type compound comprising contacting a cyclopentadiene-type compound containing an active halogen with an inorganic support having surface hydroxyl group. Also there is provided a method of preparing a supported metallocene comprising reacting the supported cyclopentadiene-type compound with a transition metal compound under suitable conditions. There is also provided a process for producing bridged cyclopentadiene-type ligands having a bridge having branch that has a terminal vinyl group. Also metallocenes of these ligands are provided. Still further there is provided a process for producing bridged cyclopentadiene-type ligands having a bridge having a branch that has a terminal active halogen. The resulting new ligands and supported metallocenes produced therefrom are also provided.