Disclosed are processes, systems, and reaction systems for the oligomerization of ethylene to form an oligomer product in a reaction zone using a catalyst system having i) a chromium component comprising an N.sup.2-phosphinyl amidine chromium compound complex, an N.sup.2-phosphinyl formamidine chromium compound complex, an N.sup.2-phosphinyl guanidine chromium compound complex, or any combination thereof, and ii) an aluminoxane. Ethylene can be contacted with an organic reaction medium to form an ethylene feedstock mixture prior to contact with the catalyst system. The ethylene feedstock mixture can be contacted with the catalyst system inside or outside of the reaction zone.

Disclosed 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 comprising (a) a chromium component comprising an N.sup.2-phosphinyl amidine chromium compound complex, an N.sup.2-phosphinyl formamidine chromium compound complex, an N.sup.2-phosphinyl guanidine chromium compound complex, or any combination thereof, and (b) 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.

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.

Disclosed herein are processes, systems, and reaction systems for the oligomerization of ethylene to form an 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. Ethylene can be contacted with an organic reaction medium to form an ethylene feedstock mixture prior to contact with the catalyst system. The ethylene feedstock mixture can be contacted with the catalyst system inside or outside of the reaction zone.

The present invention provides novel Ruthenium-based transition metal complex catalysts comprising specific ligands, their preparation and their use in hydrogenation processes. Such complex catalysts are inexpensive, thermally robust, and olefin selective.

The invention relates to a novel process for the preparation of 2,2′-bis indenyl biphenyl ligands of following formula (3): The invention also relates to metallocene complexes prepared using the novel process for the preparation of 2,2-bis indenyl biphenyl ligands. The invention also relates to novel intermediates used in the process for the preparation of 2,2′-bis indenyl biphenyl ligands. ##STR00001##

The present invention relates to a ligand compound, a catalyst system for olefin oligomerization, and a method for olefin oligomerization using the same. The present ligand compound is a compound having a certain new structure and enables provision of a catalyst system for olefin oligomerization that can oligomerize ethylene with higher catalytic activity.

The invention relates to oligomerization of olefins, such as ethylene, to higher olefins, such as a mixture of 1-hexene and 1-octene, using a catalyst system that comprises a) a source of chromium b) one or more activators and c) a phosphacycle-containing ligating compound. Additionally, the invention relates to a phosphacycle-containing ligating compound and a process for making said compound.

The invention relates to oligomerization of olefins, such as ethylene, to higher olefins, such as a mixture of 1-hexene and 1-octene, using a catalyst system that comprises a) a source of chromium b) one or more activators and c) a phosphacycle-containing ligating compound. Additionally, the invention relates to a phosphacycle-containing ligating compound and a process for making said compound.

The selective oligomerization of ethylene to produce a mixture comprising octene and hexene is conducted in the presence of a catalyst system comprising a source of chromium; two different P—N—P ligands and an activator. The phosphorus atoms of both ligands have ortho-fluoro phenyl substituents. The nitrogen atom of the first ligand has an isopropyl substituent. The nitrogen of the second ligand has a larger/bulkier hydrocarbyl substituent on the N atom. The hexene produced by the process of this invention has very high alpha selectivity.