Methods of preparing oligomers of an olefin are provided. The methods can include providing an alkylaluminum compound and irradiating the alkylaluminum compound with microwave radiation to provide an irradiated alkylaluminum compound. The methods can further include mixing the irradiated alkylaluminum compound with a chromium compound, a pyrrole compound, and a zinc compound to provide a catalyst composition. The methods can further include contacting an olefin with the composition to form oligomers of the olefin. The olefin can include ethylene, and the oligomers of the olefin can include 1-hexene.

The present disclosure relates to a ligand compound, a catalyst system for oligomerization, and a method for olefin oligomerization using the same. The catalyst system for oligomerization using the ligand compound according to the present disclosure has excellent catalytic activity, exhibits high selectivity to 1-hexene and 1-octene, and greatly reduces the production of the by-products, thereby enabling efficient preparation of alpha-olefin.

The present invention discloses a homogeneous, single site catalyst of formula (I) and a process for preparation thereof using a ligand. The present invention further discloses a process for preparation of linear polyethylene of high molecular weight and degree of crystallinity by using the homogeneous, single site catalyst of formula I.

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The present disclosure relates to a catalyst system comprising i) (a) an N.sup.2-phosphinyl bicyclic amidine chromium salt or (b) a chromium salt and an N.sup.2-phosphinyl bicyclic amidine and ii) an organoaluminum compound. The present disclosure also relate to a process comprising: a) contacting i) ethylene; ii) a catalyst system comprising (a) an N.sup.2-phosphinyl bicyclic amidine chromium salt complex or (b) a chromium salt and an N.sup.2-phosphinyl bicyclic amidine; ii) an organoaluminum compound, and iii) optionally an organic reaction medium; and b) forming an oligomer product in a reaction zone.

Methods of preparing oligomers of an olefin are provided. The methods can include providing a composition that includes an alkylaluminum compound, a chromium compound, and a hydrocarbon solvent. The hydrocarbon solvent can include n-undecane, a C8-C11 alkane compound having one branch, or a mixture thereof. The methods can further include contacting an olefin with the composition to form oligomers of the olefin. The olefin can include ethylene, and the oligomers of the olefin can include 1-hexene.

A method of precipitating polymer and deactivated organometallic catalyst in an olefin oligomerization reaction is provided. The method includes providing an effluent stream from an olefin oligomerization reaction. The effluent stream can include a polymer and an organometallic catalyst. The method can further include introducing sorbent particles into the effluent stream. The sorbent particles can include a deactivating agent. The deactivating agent can be water, an alcohol, an amine, an amino alcohol, or a combination thereof. At least about 10% of the sorbent particles can have a particle size in a range from 10 μm and 60 μm. The method can further include cooling the effluent stream, thereby precipitating polymer and deactivated organometallic catalyst from the effluent stream to provide a precipitate that includes sorbent, polymer, and deactivated catalyst.

Catalyst compositions and processes for the oligomerization of ethylene to 1-octene 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.

A catalyst system comprising i) a 2-[(phosphinyl)aminyl] cyclic imine transition metal compound complex and ii) an organoaluminum compound. A process comprising contacting i) ethylene, ii) a catalyst system comprising (a) a 2-[(phosphinyl)aminyl] cyclic imine transition metal compound complex, and (b) an organoaluminum compound, and iii) optionally hydrogen to form an oligomer product.

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 processes, systems, and reaction systems for the oligomerization of ethylene to form an ethylene oligomer product in a reaction zone using a catalyst system having i) a chromium component comprising a heteroatomic ligand chromium compound complex of the type disclosed herein, and ii) an aluminoxane. A C.sub.3+ olefin can be present in the reaction zone for a period of time, where the C.sub.3+ olefin is not an ethylene oligomer formed in-situ within the reaction zone.