E.i. Dupont De Nemours and Company

Leland Stanford Junior University

Other

Brookhaven Science Associates, Lcc

Elisabeth Muriel Hauptman

Lynda Kaye Johnson

Steven Dale Ittel

Lin Wang

Robert M Waymouth

Alison Margaret Anne Bennett

R Morris Bullock

Geoffrey W Coates

Ying Wang

Jerald Feldman

Paul Joseph Fagan

Edward Bryan Coughlin

Anju Parthasarathy

Robert D Simpson

Marcel Schlaf

Alex Sergey Ionkin

Maurice S Brookhart

Elizabeth Forrester McCord

Kerwin D Dobbs

Catherine E Radzewich

Barbara F M Kimmich

Transition metal complexes of selected monoanionic phosphine ligands, which also contain a selected Group 15 or 16 (IUPAC) element and which are coordinated to a Group 3 to 11 (IUPAC) transition metal or a lanthanide metal, are polymerization catalysts for the (co)polymerization of olefins such as ethylene and &#x3b1;-olefins, and the copolymerization of such olefins with polar group-containing olefins. These and other nickel complexes of neutral and monoanionic bidentate ligands copolymerize ethylene and polar comonomers, especially acrylates, at relatively high ethylene pressures and surprisingly high temperatures, and give good incorporation of the polar comonomers and good polymer productivity. These copolymers are often unique structures, which are described.

Catalysts for olefin polymerization

The present invention is a process for the catalytic hydrogenation of ketones and aldehydes to alcohols at low temperatures and pressures using organometallic molybdenum and tungsten complexes and the catalyst used in the process. The reactants include a functional group which is selected from groups represented by the formulas R*(C&boxH;O)R&prime; and R*(C&boxH;O)H, wherein R* and R&prime; are selected from hydrogen or any alkyl or aryl group. The process includes reacting the organic compound in the presence of hydrogen and a catalyst to form a reaction mixture. The catalyst is prepared by reacting Ph C A with a metal hydride. A represents an anion and can be BF , PF , CF SO or Bar&prime; , wherein Ar&prime;&equals;3,5-bis(trifluoromethyl)phenyl. The metal hydride is represented by the formula: HM(CO) &lsqb;&eegr; :&eegr; &mdash;C H (XH ) PR &rsqb; wherein M represents a molybdenum (Mo) atom or a tungsten (W) atom; X is a carbon atom, a silicon atom or a combination of carbon (C) and silicon (Si) atoms; n is any positive integer; R represents two hydrocarbon groups selected from H, an aryl group and an alkyl group, wherein both R groups can be the same or different. The metal hydride is reacted with Ph C A either before reacting with the organic compound or in the reaction mixture.

Catalytic ionic hydrogenation of ketones using tungsten or molybdenum catalysts with increased lifetimes

Selected olefins such as ethylene and &agr;-olefins are polymerized by nickel &lsqb;II&rsqb; complexes of certain monoanionic ligands. The polyolefins are useful in many applications such as molding resins, film, fibers and others. Also described are many novel nickel compounds and their precursors, as well a novel ligands.

Polymerization of olefins

This invention is directed to novel catalysts the structure and activity of which can be controlled to produce a wide range of alpha olefin polymers and co-polymers, and preferably for the production of stereoblock poly alpha olefins comprising a wide range of preselected amorphous and crystalline segments for precise control of the physical properties thereof, principally elastomeric thermoplastic properties. More specifically, this invention is directed to novel catalysts and catalysts systems for producing stereoblock polypropylene comprising alternating isotactic and atactic diastereosequences, which result in a wide range of elastomeric properties. The amount and numbers of crystalline sections, the isotactic pentad content, the number and length of intermediate atactic chains and overall molecular weight are all controllable by the steric structure of the catalysts and the process conditions. The novel catalysts provided by the present invention are ligand-bearing non-rigid metallocenes the geometry of which can be controlled on a time scale that is slower than the rate of olefin insertion, but faster than the average time to construct (polymerize) a single polymer chain, in order to obtain a stereoblock structure in the produced polyolefins. The symmetry of the catalyst structure is such that upon isomerization the catalyst symmetry alternates between a chiral and an achiral geometry. This geometry alteration can be controlled by selecting ligand type and structure, and through control of polymerization conditions to precisely control the physical properties of the resulting polymers.

Catalysts for thermoplastic elastomeric olefin polymers

Secondary alcohols, specifically diols and polyols, are dehydroxylated to the corresponding primary alcohols using a homogeneous organometallic ruthenium complex catalyst.

Catalytic dehydroxylation of diols and polyols

Polymers are produced using transition metal complexes that have sites capable of binding a Lewis acid in close proximity to the metal center.

Ketones and aldehydes are hydrogenated to the corresponding alcohol or alkyl group, using H gas as the stoichiometric reductant, and organometallic ruthenium complexes as the catalysts.

Catalytic reduction of ketones and aldehydes using organometallic ruthenium complexes

Thermoplastic elastomeric olefin polymers

Disclosed is a process for the production of chemical intermediates by the cross dimerization of two compounds containing carbon-carbon double bonds, wherein said process is catalyzed by a nickel II catalyst which is a complex with .eta..sup.3 carbon-based allyl or substituted allyl, trisubstituted phosphine, and a weakly coordinating ligand. This catalyst may be used to selectively cross-dimerizes ethylene and methyl acrylate to give methyl 4-pentenoate, a nylon 6,6 intermediate.

Cross-dimerization of olefins

Thermoplastic elastomeric olefin polymers, method of production and

Growing community of inventors

Wilmington, DE, United States of America

Elisabeth Muriel Hauptman