Supported chromium catalysts with an average valence less than +6 and having a hydrocarbon-containing or halogenated hydrocarbon-containing ligand attached to at least one bonding site on the chromium are disclosed, as well as ethylene-based polymers with terminal alkane, aromatic, or halogenated hydrocarbon chain ends. Another ethylene polymer characterized by at least 2 wt. % of the polymer having a molecular weight greater than 1,000,000 g/mol and at least 1.5 wt. % of the polymer having a molecular weight less than 1000 g/mol is provided, as well as an ethylene homopolymer with at least 3.5 methyl short chain branches and less than 0.6 butyl short chain branches per 1000 total carbon atoms.

Disclosed herein are a chromium compound represented by Formula 1a or 1b and a catalyst system including the same, exhibiting superior catalytic activity in an olefin trimerization reaction:

[{CH.sub.3(CH.sub.2).sub.3CH(CH.sub.2CH.sub.3)CO.sub.2}.sub.2Cr(OH)]  [Formula 1a]

[{CH.sub.3CH.sub.2CH(CH.sub.2CH.sub.3)CO.sub.2}.sub.2Cr(OH)]  [Formula 1b].

The present invention relates to an oligomerization catalyst including a transition metal or transition metal precursor, a halogen-substituted organic ligand, and a heteroatom ligand, and to a method for selectively preparing 1-hexene or 1-octene from ethylene using the catalyst.

A method comprising obtaining a control catalyst set having a plurality of members each having a control characteristic, wherein the members of the control catalyst set comprise a transition metal and an organic ligand, selecting an intermediate formed during a catalytic cycle of each member of the control catalyst set, geometrically and energetically optimizing a structure of the intermediate, determining one or more characteristics of the geometrically and energetically optimized structure of the intermediate, determining a mathematical relationship between the control characteristic and the one or more characteristics of the geometrically and energetically optimized structure of the intermediate, utilizing the mathematical relationship to identify one or more members of a sample catalyst set having a control characteristic within a desired range, contacting the identified sample catalyst with a reactant under conditions suitable for the formation of product, and recovering the product.

The present specification relates to an olefin oligomerization method and specifically to an olefin oligomerization method comprising the step of subjecting an olefin to a multimerization reaction by controlling a reaction temperature such that the weight ratio of 1-hexene to 1-octene within a product comprising 1-hexene and 1-octene has a predetermined value, in the presence of an oligomerization catalyst system comprising a ligand compound, a transition metal compound, and a cocatalyst, wherein the predetermined value for the weight ratio of 1-hexene to 1-octene within the product is selected in a range of 1:0.5 to 1:7. By the method, 1-hexene and 1-octene can be produced in a desired ratio.

Catalyst compositions and processes for the oligomerization of ethylene to 1-hexene are described. The catalyst composition includes a triamino bisphospino (NPNPN) ligand system with specific phosphorous and nitrogen ligands. The terminal nitrogen atoms include linear alkyl hydrocarbons that differ in the number of carbon atoms by 3.

The present invention relates to a compound represented by the chemical formula 1, a catalyst system for olefin oligomerization comprising the same, and a method for oligomerizign olefins using the same, and the catalyst system for olefin oligomerization according to the present invention has excellent catalytic activity as well as high selectivity for 1-hexene or 1-octene, thereby enabling more efficient preparation of alpha-olefins.

Catalyst preparation systems and methods for preparing reduced chromium catalysts are disclosed, and can comprise irradiating a supported chromium catalyst containing hexavalent chromium with a light beam having a wavelength within the UV-visible light spectrum. Such reduced chromium catalysts have improved catalytic activity compared to chromium catalysts reduced by other means. The use of the reduced chromium catalyst in polymerization reactor systems and olefin polymerization processes also is disclosed, resulting in polymers with a higher melt index.

Compounds can be used as catalysts, particularly in ring-opening polymerization reactions, including ring-opening co-polymerization (ROCOP) reactions, or in isocyanate trimerization reactions. The compounds have the formula L-M-X.sub.n, where L is a pyridyl-bis(iminophenolate) ligand, M is a metal ion, X is a co-ligand to balance the charge of the compound, and n is an integer from 0 to 7. The compounds can be prepared by base condensation of a pyridyl-diamine compound with an aldehyde or ketone.

A process for the carbonylation of epoxides in the presence of catalyst systems, wherein the carbonylation takes place in the presence of carbon monoxide, and wherein the catalyst system contains a molybdenum-based compound. Carbonylation products as well as carbonylation derivatives and to the use of the claimed catalyst systems for the carbonylation of epoxides are also provided.