Abstract: The reduction of a titanium tetrahalide with titanium in the presence of an ether which forms an adduct with titanium trihalide, wherein an adduct insoluble in said ether is produced.

Abstract: Star polymers obtainable by polymerization of vinylaromatic monomers with a branching monomer unit containing at least two vinylaromatic functional radicals in the presence of a catalyst obtainable from A) a transition-metal complex from sub-group II to VIII, B) a cation-forming agent and C), if desired, an aluminum compound.

Abstract: An organometallic complex of formula(I) having a low evaporation temperature can be used as a precursor for the MOCVD of a metal compound thin film on semiconductor devices wherein, M is Ti or Zr; R1, R2, R3 and R4 are each independently H or C1-4 alkyl; and m is an integer ranging from 2 to 5.

Abstract: Star polymers obtainable by polymerization of vinylaromatic monomers with a branching monomer unit containing at least two vinylaromatic functional radicals in the presence of a catalyst obtainable from A) a transition-metal complex from sub-group II to VIII, B) a cation-forming agent and C), if desired, an aluminum compound.

Abstract: A chiral ligand of the formula (II) or formula (II′), was synthesized. The chiral ligand (II) or formula (II′) can chelate to metals to form a catalytic complex to catalyze the addition of trimethylsilyl cyanide to aldehydes to give optically active cyanohydrin, individually.

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: An aqueous tannin stain-inhibiting coating composition comprising a titanate coupling agent. Also, a process for inhibiting tannin staining in a tannin-containing substrate is disclosed which involves applying to the substrate a coating composition comprising a titanate coupling agent.

Abstract: Process for transesterifying &agr;-ketocarboxylic esters in an anhydrous alcohol as reaction medium in the presence of tin catalysts, titanium catalysts, zirconium catalysts or lithium catalysts or of acetylacetonates as catalysts.

Abstract: Disclosed is an olefin polymerization catalyst comprising: a transition metal compound comprising one transition metal selected from the group consisting of Ti, Zr and Hf, and at least two ligands, wherein one ligand is a group having a cyclopentadienyl skeleton, and the remaining at least one ligand is a monovalent, bidentate, anionic chelating ligand having two coordinating atoms each coordinated to the transition metal, one of which atoms is selected from the group consisting of O, S, Se and Te, and the other of which atoms is selected from the group consisting of N, S, Se and Te, and wherein one of the remaining at least one ligand is optionally bonded to the group having a cyclopentadienyl skeleton through a bridging group. Also disclosed is a method for efficiently producing an olefin homopolymer or olefin copolymer by using this catalyst.

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

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

Abstract: It is made possible to carry out asymmetric organic syntheses such as an asymmetric imono aldol reaction etc. catalytically with high reactivity and selectivity. An asymmetric zirconium catalyst having a structure that zirconium (IV) being an active central atom of the catalyst and being bonded via oxygen atoms to two molecules of optically active binaphthyl groups is proposed.

Abstract: A catalyst precursor having the formula: ##STR1## wherein M is a Group IVB metal; each L is a monovalent, bivalent, or trivalent anion;X and Y are each heteroatoms;each Cyclo is a cyclic moiety;each R.sup.1 is a group containing 1 to 50 atoms selected from the group consisting of hydrogen and Group IIIA to Group VIIA elements, and two or more adjacent R.sup.1 groups may be joined to form a cyclic moiety;each R.sup.2 is a group containing 1 to 50 atoms selected from the group consisting of hydrogen and Group IIIA to Group VIIA elements, and two or more adjacent R.sup.2 groups may be joined to form a cyclic moiety;W is a bridging group; andeach m is independently an integer from 0 to 5.

Abstract: A catalyst composition for the polymerization of olefins is provided, comprising a bis(hydroxy aromatic nitrogen ligand) transition metal catalyst precursor and an activating cocatalyst.

Abstract: In metal complexes of the formula I ##STR1## the substituents have the following meanings: M is a metal of transition group III, IV, V or VI of the Periodic Table of the Elements or a metal of the lanthanide series,Y is a negative leaving atom or a negative leaving group,X and X.sup.1 are negatively charged or uncharged atoms of main group IV, V or VI of the Periodic Table of the Elements,Z is hydrogen, C.sub.1 -C.sub.10 -alkyl, C.sub.3 -C.sub.10 -cycloalkyl, C.sub.1 -C.sub.10 -alkoxy, C.sub.1 -C.sub.10 -alkylthio or dialkylamido having from 1 to 4 carbon atoms in each alkyl radical,R.sup.1 to R.sup.11 are hydrogen, carboorganic or organosilicon radicals,n is 0, 1 or 2 andthe valence of M is 2+n.

Abstract: A class of metallocene compounds having two substituted cyclopentadienyl rings bridged by an alkylidene group wherein the cyclopentadienyl groups can be indenyl groups. The metallocene compounds have the following structures: ##STR1## The metallocenes are characterized by three principal features: (i) the cyclopentadienyl groups are substituted at the 3-position with a substituent other than hydrogen, while R.sup.2 in the 2-position bears a hydrogen (formula (I)) or is part of a condensed benzene ring (formula (II)); (ii) the bridge is a substituted-methylene bridge, i.e. a methylene group bearing at least one substituent other than hydrogen (R.sup.6 is always different from hydrogen); and (iii) the cyclopentadienyl groups are identically substituted (page 2, line 23). These metallocene compounds can be suitably used as catalyst components for the polymerization of olefins.

Abstract: Metal complexes having constrained geometry and a process for preparation thereof, addition polymerization catalysts formed therefrom, processes for preparation of such addition polymerization catalysts, methods of use, and novel polymers formed thereby, including ElPE resins and pseudo-random copolymers, are disclosed and claimed.

Abstract: An ultrafine titanium dioxide powder is disclosed that can be produced by hydrothermal treating an amino titanium oxalate composition. Ultrafine titanium dioxide powders are useful in cosmetic and other applications for controlling exposure to ultraviolet (UV) light.

Abstract: A metallocene having one or two hydrocarbyl groups bonded to a Group 4 metal are produced from a crude impure pasty or non-wet mixture containing at least 50% by weight of a metallocene having two halogen atoms bonded to a Group 4 metal atom, by (a) mixing liquid aromatic hydrocarbon with the crude impure pasty or non-wet mixture; (b) mixing a solution of an organolithium compound in a suitable anhydrous ether or paraffinic hydrocarbon solvent or a mixture thereof, with the mixture from (a) and agitating the resulting mixture so that lithium halide solids are formed; and (c) separating the solids and recovering the resultant liquid portion which is mainly a solution of the metallocene having one or two hydrocarbyl groups bonded to a Group 4 metal. Additional optional steps include (d) replacing the original solvent from the solution from (c) with a liquid paraffinic hydrocarbon diluent to form a slurry of product solids; and (e) recovering the product metallocene solids.

Abstract: Inorganic oxides of substantially uniform particle size distribution are prepared by contacting aqueous solutions of an inorganic salt and an inorganic base across a porous membrane wherein the membrane contains a plurality of pores which allows for precipitation of a substantially mono-disbursed size inorganic oxide particles on one side of the membrane and precipitation of a salt of the corresponding base on a second side of the membrane.

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 process for the preparation of multinuclear cluster compounds by reacting a metal carbonyl with iodine, and use of these clusters and clusters derived from them, in diagnostic imaging. Novel multinuclear cluster compounds are also disclosed.

Abstract: The object of the invention resides in the development of an improved process for synthesizing metallocene compounds useful as olefin polymerization catalysts.A new process for synthesizing metallocene compounds of formulae (IV) and (IV') comprises a reaction of formula (I) with formula (II) or (II') to afford formula (III) or (III'), and then a reaction of a halogenating agent.In formulae (IV) and (IV') described below, M.sup.1 is a group IV transition-metal atom, L.sup.1 and L.sup.2 can be each other identical or different and are substituted or unsubstituted cyclopentadienyl, substituted or unsubstituted indenyl or substituted or unsubstituted fluorenyl groups, B is a hydrocarbon having 1-20 carbon atoms, silylene having 1-20 carbon atoms, oligosilylene or germylene groups, binding to L.sup.1 and L.sup.2, Y can be identical or different and is each independently of one another a halogen atom. Further, M.sup.1 can be coordinated with an ether or an amine at any coordination number.

Abstract: Metallocene complexes having a cationic bridge of the formula ##STR1## where the substituents have the following meanings: M is a metal of transition group III, IV, V or VI of the Periodic Table of the Elements or a metal of the lanthanide group,X is fluorine, chlorine, bromine, iodine, hydrogen, C.sub.1 -C.sub.10 -alkyl, C.sub.6 -C.sub.15 -aryl or --OR.sup.5,R.sup.1 to R.sup.12, Y, Z and n having the meanings set out in the specification, said complexes can be prepared via ligand systems of the formula II ##STR2## as intermediates.

Abstract: A novel trivalent Group IVB metal complex for preparing syndiotactic vinyl aromatic polymers is disclosed which is coordinated by a bidentate ligand and is represented by the formula (I):(C.sub.5 R.sub.n H.sub.5-n)M(BD).sub.m Y.sub.p (I)wherein C.sub.5 R.sub.n H.sub.5-n is a substituted or unsubstituted cyclopentadienyl group, n is an integer between 0 and 5, and R is C.sub.1 to C.sub.12 alkyl, aryl, substituted alkyl, or substituted aryl; M is a trivalent Group IVB metal; (BD) is a bidentate ligand with -1 valence, having a coordinating group which is capable of forming a coordinating bond or a chelating bond with the metal M; Y is selected from the group consisting of alkyl, aryl, aralkyl, halogen and hydrogen; m is an integer of 1 or 2; and m+p=2.

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: 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: Process for the preparation of N-alkyl substituted metal carbamate solutions characterized in that a water solution of the salt of the metal of which the corresponding carbamate is to be obtained, is reacted with an organic solution, basically consisting of an aprotic solvent and a secondary amine, saturated with carbon dioxide.The above solutions can be used as catalysts in polymerization reactions of unsaturated monomers or for supporting metals on inorganic oxides.

Abstract: Metallocene compounds of a Group 4 or 5 metal having two fluorenyl ligands bridged with a single silicon or germanium atom, said atom having two substituent groups containing a total of at least four carbon atoms, are useful as catalyst components for the polymerization of olefins. Particularly, it is possible to prepare high molecular weight atactic polypropylene with improved yields with respect to the known catalysts.

Abstract: A process is disclosed for preparing a perfluoroalkyl sulfonate of the formula R.sub.a MX.sub.b-c O.sub.g ?(SO.sub.3).sub.d (R.sub.f).sub.e !.sub.c. This process involves reacting a reagent of the fonnula R.sub.a MX.sub.b O.sub.g and a second reagent of the formula R'.sub.x E?(SO.sub.3).sub.d (R.sub.f).sub.e !.sub.y,whereR is selected from the group consisting of C.sub.1 to C.sub.6 alkyl, C.sub.1 to C.sub.6 perfluoroalkyl, cyclopentadienyl (i.e., C.sub.5 H.sub.5), phenyl and perfluorophenyl;M is selected from the group consisting of transistion metals of groups 3 to 12, main group elements of group 13 to 16 and lanthanide metals;X is selected from the group consisting of F, Cl and Br;R.sub.f is selected from the group consisting of C.sub.h F.sub.2h+1, C.sub.h F.sub.2h, wherein h is an integer from 0 to 10, perfluorophenyl, C.sub.6 F.sub.4 (CF.sub.2).sub.2 i, wherein i is an integer from 0 to 6, provided that when E is boron, R.sub.f is selected from the group consisting of C.sub.h' F.sub.

Abstract: A catalyst composition comprising a bis-amide compound represented by the formula ##STR1## wherein M is zirconium, hafnium or titanium; each N is a three coordinate nitrogen atom; each e is Si, Ge or Sn; each Z is, independently, a hydride or R; each R is, independently, a hydrocarbyl one or more carbon atoms of which may be substituted by an element selected from Si, O, P, N and S; L is a neutral Lewis base and m is a number from 0 to 2; or a dimer thereof and a second component. Preferably the second component is a compound which is capable of providing a bulky and labile anion ?A!.sup.-, which anion is substantially non-coordinating under the reaction conditions and contains at least one boron atom. Also provided is a process for oligomerizing or co-oligomerizing alpha olefins in the presence of this catalyst composition.

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: A process for the preparation of multinuclear cluster compounds by reacting a metal carbonyl with iodine, and use of these clusters and clusters derived from them, in diagnostic imaging. Novel multinuclear cluster compounds are also disclosed.

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: Reaction mixtures prepared from tetraalkyl titanates and mixtures of glycols, said reaction mixtures comprising titanium bisglycoxide oligomers, may be used as depolymerization catalysts for conversion of linear polyesters to macrocyclic polyester oligomers.

Abstract: Polyolefins with a molecular weight distribution M.sub.w /M.sub.n .gtoreq.3.0, which may be monomodal, bimodal or multimodal, can be obtained by polymerization or copolymerization of olefins with a catalyst system consisting of an aluminoxane and a transition metal component (metallocene), in which the transition metal component consists of at least one zirconocene of the formula I and at least one zirconocene of the formula Ia ##STR1## or alternatively of at least 2 zirconocenes of the formula I.

Abstract: An organometallic zirconium precursor, represented by following formula:L.sub.x .multidot.Zr(THD).sub.4 ?I!wherein L is an electron donor ligand selected from the group consisting of NR.sub.3 (R.dbd.H, CH.sub.3) gas and Cl.sub.2 gas; THD denotes 2,2',6,6'-tetramethyl-3,5-heptanedione; and x is in the range of 0.3 to 1.5 with the proviso that L is NR.sub.3 or in the range of 0.5 to 2 with the proviso that L is Cl.sub.2, is prepared by flowing a gas phase electron donor into a bubbler containing bis (2,2',6,6'-tetramethyl-3,5-heptanedione)Zr at a predetermined temperature, to synthesize, in-situ, an adduct. The precursor exhibits a remarkable improvement in volatility, and in stability at the vaporization point.Lead-zirconium-titanium thin films prepared from the precursor, display superior reproducibility and reliability.

Abstract: Mo adsorbent for .sup.99 Mo-.sup.99m Tc generators has a skeleton structure having mainly repeating units represented by the general formula; ##STR1## wherein X is a halogen atom or alkoxide group having one to six carbon atoms, 10% or more of X is halogen, R is an alkylene, polymethylene, or carbon chain having unsaturated bond, repeating unit (D) is bonded to any one of repeating units (A), (B), and (C), the branch structure is controlled by the content of repeating units (A), (B), and (C), the adsorbent is insoluble in water and adsorbs selectively only Mo from an aqueous solution containing Mo, and elutes .sup.99m Tc generated from a radioactive isotope .sup.99 Mo. This Mo adsorbent uses .sup.99 Mo obtained from natural Mo by (n, .gamma.) method, therefore, a generator having the same size as conventional .sup.99m Tc generators is realized.

Abstract: Diethylenetriaminepentaacetic acid monoamide derivatives, their complexes and complex salts, containing an element of atomic numbers 21-29, 31, 32, 39, 42-44, 49 or 57-83, pharmaceutical agents containing these compounds, their use as contrast media and process for their production.

Abstract: Octahydrofluorenyl metal complexes, such as octahydrofluorenyltitanium trichloride, or ring substituted octahydrofluorenyl metal complexes wherein the metal is in the +2, +3 or +4 formal oxidation state are prepared by reduction of tetra- or hexa-hydrofluorenyl metal complexes. The reduction reaction may be carried out at ambient pressure and temperature in the presence of a catalyst. The process of the present invention permits preparation of octahydrofluorenyltitanium metal complexes from a series of high yield reactions starting with fluorene.

Abstract: Chiral catalysts for enantioselectively epoxidizing a prochiral olefin and for enantioselectively oxidizing a prochiral sulfide are disclosed, together with methods of using such catalysts. In accordance with one aspect of the invention, the catalyst is a salen derivative which has the following general structure: ##STR1## In accordance with another aspect of the present invention is a method of, producing an epoxychroman using a chiral catalyst. In accordance with this method, a chromene derivative, an oxygen atom source, and a chiral catalyst are reacted under such conditions and for such time as is needed to epoxidize said chromene derivative. In accordance with yet another aspect of this invention is a method of enantioselectively epoxidizing a cis-cinnamate derivative to make taxol or an analog thereof. In accordance with another aspect a method of disproportionation of hydrogen peroxide using the catalysts of the present invention is disclosed.

Abstract: A process for rendering polymer compositions antistatic and the products of such process are described. The polymeric material is treated with a combination of selected trineoalkoxy amino zirconates and trineoalkoxy sulfonyl zirconates. These latter materials are soluble in the polyolefins, polyesters, polyamides, polyethers, polycarbonates, and polystyrenes and remain stable during the processing of these polymers. Furthermore, the antistatic agents of the invention are thermally stable to temperatures up to 825.degree. F., do not "bloom" during the polymer processing, and are colorless, permanent, non-blooming and non-moisture dependent.

Abstract: Bridged monocyclopentadienyl derivatives of a Group 4 metal are prepared by contacting a corresponding bis(cyclopentadienyl) metal complex with an alkali metal derivative or alkaline earth metal derivative of a hydrocarbyl ligand R, which is optionally substituted with one or more amino, phosphino, ether, thioether, or silyl groups. The bis(cyclopentadienyl) Group 4 metal complexes can be prepared by contacting a compound corresponding to one of the formulas (Cp).sub.3 MQ.sub.n X.sub.t, (Cp).sub.2 MQ.sub.n X.sub.t+1, or CpMQ.sub.n X.sub.t+2 and a dianionic salt compound corresponding to the formula: (L.sup.+x).sub.y (Cp*-Z-Y).sup.-2 or ((LX').sup.+x).sub.y (Cp*-Z-Y).sup.-2. An addition polymerization catalyst comprising a bis(cyclopentadienyl) Group 4 metal complex and an activating cocatalyst, and an addition polymerization process using such a catalyst.

Abstract: In accordance with the present invention there is provided a cyclopentadienyl-type ligand represented by the formula ZA, wherein Z is a cyclopentadienyl-type group, wherein A is --YPR.sub.2, --YNR.sub.2, or --NR.sub.2, wherein Y is an alkylene group containing 1 to 24 carbon atoms, wherein each R is individually selected from alkyl groups containing 1 to 20 carbon atoms. Another aspect of the invention is to provide a metallocene represented by the formula ZAMX.sub.3, wherein Z and A are as described above, M is a Group IVB or VB transition metal, and X is a halide. Other aspects of the present invention include catalyst systems comprising the metallocenes and an organoaluminoxane, processes for preparing the above defined ligands, metallocenes and catalyst systems, and polymerization processes employing the catalyst systems.

Abstract: Methods of using chiral catalysts for enantioselectively epoxidizing a prochiral olefin and for enantioselectively oxidizing a prochiral sulfide are disclosed. In accordance with one aspect of the invention, the catalyst used is a salen derivative which has the following general structure: ##STR1## In accordance with another aspect of the present invention is a method of producing an epoxychroman using a chiral catalyst. In accordance with this method, a chromene derivative, an oxygen atom source, and a chiral catalyst are reacted under such conditions and for such time as is needed to epoxidize said chromene derivative. In accordance with yet another aspect of this invention is a method of enantioselectively epoxidizing a cis-cinnamate derivative to make taxol or an analog thereof. In accordance with another aspect a method of disproportionation of hydrogen peroxide using the catalysts of the present invention is disclosed.

Abstract: Disclosed is a novel bidentate pyridine transition metal catalyst having the general formula ##STR1## where Y is O, S, NR, ##STR2## each R is independently selected from hydrogen or C.sub.1 to C.sub.6 alkyl, each R' is independently selected from C.sub.1 to C.sub.6 alkyl, C.sub.1 to C.sub.6 alkoxy, C.sub.6 to C.sub.16 aryl, halogen, or CF.sub.3, M is titanium, zirconium, or hafnium, each X is independently selected from halogen, C.sub.1 to C.sub.6 alkyl, C.sub.1 to C.sub.6 alkoxy, or ##STR3## L is X, cyclopentadienyl, C.sub.1 to C.sub.6 alkyl substituted cyclopentadienyl, indenyl, fluorenyl, or ##STR4## and "n" is 1 to 4. Also disclosed is a method of making a poly-.alpha.-olefin comprising polymerizing an .alpha.-olefin monomer using that catalyst or a catalyst that has the general formula ##STR5## where Y, M, L, X, and R' were previously defined.

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

Abstract: The invention is a catalyst system including a monocyclopentadienyl titanium compound and an alumoxane component which is highly productive for polymerizing ethylene and .alpha.-olefins to produce a high molecular weight ethylene-.alpha.-olefin copolymer having a high content of .alpha.-olefin.

Abstract: Metallocene compounds and processes for preparing such metallocene compounds are provided. Such processes for preparing such metallocene compounds comprise reacting an alkynyl ligand, an alkali metal compound, and a transition metal-containing compound.

Abstract: The invention is a catalyst system including a monocyclopentadienyl titanium compound and an alumoxane component which is highly productive for polymerizing ethylene and &agr;-olefins to produce a high molecular weight ethylene-&agr;-olefin copolymer having a high content of &agr;-olefin.