Silica-coated alumina activator-supports, and catalyst compositions containing these activator-supports, are disclosed. Methods also are provided for preparing silica-coated alumina activator-supports, for preparing catalyst compositions, and for using the catalyst compositions to polymerize olefins.

The invention relates to a method for the preparation of cyclic compounds in the metathesis of olefins from acyclic dienes comprising terminal and/or non-terminal C═C double bonds; the invention also relates to the use of homogeneous ruthenium complexes and homogeneous ruthenium complexes deposited on a solid support as catalysts and/or pre-catalysts for the preparation of cyclic olefins in olefin metathesis reactions.

The invention relates to polyoxometalates represented by the formula (A.sub.n).sup.m+[M′M.sub.12O.sub.y(RCOO).sub.zH.sub.q].sup.m− or solvates thereof, corresponding supported polyoxometalates, and processes for their preparation, as well as corresponding metal clusters, optionally in the form of a dispersion in a liquid carrier medium or immobilized on a solid support, and processes for their preparation, as well as their use in reductive conversion of organic substrate.

Novel compositions and systems for closure of wounds are disclosed. The compositions provide devices of improved flexibility and elasticity and are readily applied to wound sites or over wound closure devices. The present invention is also directed to a novel platinum catalyst for use in such compositions. The catalyst provides for rapid curing on topical surfaces such as skin and bonds to such surfaces in about 2-5 minutes.

Presented herein is a coupling method for the preparation of 1,2-di(thiophen-2-yl)ethane-1,2-diol compounds, including (E)-1,2-di(thiophen-2-yl)ethene-1,2-diol, via a Cu(II) catalyst.

The present invention relates to improvements in known gold containing catalysts. In particular, the present invention relates to improving the stability and/or inhibition of deactivation of gold containing catalysts via the addition of an inorganic oxide, hydroxide, oxo-salt or oxo-acid. There is also disclosed a method for preparing said catalyst most suitably via an impregnation method. Such catalysts are useful in the production of vinyl chloride monomer.

Platinum complexes having ferrocene-diphosphine ligands for catalysis of the hydroxycarbonylation of ethylenically unsaturated compounds.

Catalyst systems suitable for tetramerizing ethylene to form 1-octene may include a catalyst having a structure according to Formula (VI) or Formula (VII). In Formulas (VI) and (VII), X is a halogen, a (C.sub.2-C.sub.30) carboxylate, acetylacetonate, or a (C.sub.1-C.sub.30) hydrocarbyl; L.sub.1 is a neutral coordinating ligand; n is an integer from 0 to 6; Y is a (C.sub.6-C.sub.20)fluorine-substituted aryl, a (C.sub.6-C.sub.20)fluorine-substituted aryloxy, or a (C.sub.1-C.sub.20)fluorine-substituted alkoxy; and L∩L is a bidentate chelating ligand. The catalyst system may also include an aluminum containing agent which includes a reaction product of an organoaluminum compound and an antifouling compound. The antifouling compound may include one or more quaternary salts.

Catalyst systems suitable for tetramerizing ethylene to form 1-octene may include a catalyst having a structure according to Formula (VI) or Formula (VII). In Formulas (VI) and (VII), X is a halogen, a (C.sub.2-C.sub.30) carboxylate, acetylacetonate, or a (C.sub.1-C.sub.30) hydrocarbyl; L.sub.1 is a neutral coordinating ligand; n is an integer from 0 to 6; Y is a (C.sub.6-C.sub.20)fluorine-substituted aryl, a (C.sub.6-C.sub.20)fluorine-substituted aryloxy, or a (C.sub.1-C.sub.20)fluorine-substituted alkoxy; and L∩L is a bidentate chelating ligand. The catalyst system may also include an aluminum containing agent which includes a reaction product of an organoaluminum compound and an antifouling compound. The antifouling compound may include one or more organic acids, organic acid salts, esters, anhydrides, or combinations of these.

This invention relates to a supported catalyst system comprising: (i) at least one first catalyst component comprising a group 4 bis(phenolate) complex; (ii) at least one second catalyst component comprising a 2,6-bis(imino)pyridyl iron complex; (iii) activator; and (iv) support. The catalyst system may be used for preparing polyolefins, such a bimodal polyethylene, typically in a gas phase polymerization.