Abstract: A catalyst used for trimerization of ethylene into 1-hexene is descrobed, which comprises (i) a specific organometallic complex having a neutral multidentate ligand having a tripod structure, (ii) an alkylaluminoxane, and an optional ingredient selected from: (iii) a halogenated inorganic compound, (iv) a specific alkyl group-containing compound, (v) a combination of a halogenated inorganic compound with a specific alkyl group-containing compound, (vi) an amine compound and/or an amide compound, and (vii) a combination of an amine compound and/or an amide compound with a specific alkyl group-containing compound.

Abstract: An oligomerization process for the production of higher aliphatic olefins is disclosed. In the process, a liquid oligomerization feed stream comprising lighter aliphatic olefins is passed to a reactor vessel. The liquid oligomerization feed stream is transported upwardly in the reactor vessel against gravity through a fixed bed of solid oligomerization catalyst under oligomerization conditions. The catalyst has a Hammett acidity value of ?4 or less. A liquid oligomerization effluent stream is recovered comprising product higher aliphatic olefins.

Abstract: The invention relates to a process 1-olefins b telomerization of compounds having conjugated double bonds with a telogen in the presence of a noble metal telomerization catalyst, hydrogenation of the telomer and cleavage of the hydrogenated intermediate. Use of he 1-olefin as comonomer.

Abstract: The invention relates to a process for preparing 1-octene by reacting 1,3-butadiene with a telogen of the formula H—X—Y—H, where X is O, N, S or P and Y is C, N or Si and X and Y bear, depending on their valence, further substituents, in the presence of a telomerization catalyst to form a telomer of the formula H2C═CH—CH2—CH2—CH2—CH═CH—CH2—X—Y—H, partially hydrogenating the telomer to form a 1-substituted 2-octene of the formula H3C—CH2—CH2—CH2—CH2—CH═CH—CH2—X—Y—H and dissociating the 1-substituted 2-octene to give 1-octene.

Abstract: A catalytic composition comprising at least one nickel compound mixed or complexed with at least one tertiary phosphine or a phosphite carrying a functional group, at least partly dissolved in a non-aqueous medium with an ionic nature resulting from bringing at least one aluminum halide into contact with at least one quaternary ammonium halide and/or at least one quaternary phosphonium halide, is useful for dimerizing, co-dimerizing and oligomerizing olefins. Functional groups include, but are not limited to, an amine, a cyclic amine, a nitrogen-containing heterocycle, an ester, an acid, an alcohol, a quaternary ammonium, a quaternary phosphonium, a sulfonium, a sulfonate or a phosphonate group.

Abstract: The invention is a method and catalyst for selectively and efficiently producing short chain linear &agr;-olefins. The method includes contacting olefinic monomers under oligomerization conditions with the catalyst composition which comprises a composition prepared in situ by reacting a nickel compound selected from the group consisting of halides, hydrides, triflates, acetates, borates, C1, through C12 alkyl, C1 through C12 alkoxy, C3 through C12 cycloalkyl, C3 through C12 cycloalkoxy, aryl, thiolates, carbon monoxide, cyanate, olefins including diolefins and cycloolefins, and any other moiety into which a monomer can insert and mixtures thereof, with an amine ligand wherein said ligand is a nitrogen-containing ligand having one or more nitrogen atoms.

Abstract: This invention is to a method of oligomerizing an olefin feed stream. The olefin feed stream contains at least one C2 to C12 olefin to obtain an olefin feed stream and has from about 1,000 ppm to about 10 percent by weight oxygenated hydrocarbon. The olefin is oligomerized by contacting with an acid based oligomerization catalyst.

Abstract: A catalytic composition for the dimerization, the codimerization or the oligomerization of olefins is obtained by bringing into contact at least one nickel compound that contains a heterocyclic carbene with at least one hydrocarbylaluminum halide and optionally at least one organic solvent. It is used in a process of dimerization, codimerization or oligomerization of olefins.

Abstract: The invention relates to novel transition metal complexes of the formula (I) 1

Abstract: The invention pertains to a process of removing phosphorous-containing impurities and preferably also dienes, from an olefin stream using a sorbent selected from the group consisting of an acidic ion exchange resin, an acidic zeolite, an acidic alumina, a neutral alumina, and an activated carbon. The olefin stream preferably comprises primarily olefins having at least 6 carbon atoms.

Abstract: A process is described for carrying out olefin oligomerisation in two catalysis steps of different types, using an organic feed containing at least one olefin. The cut to be treated, containing at least one olefin (Cn), is introduced into a first reaction zone where, in a first step, it undergoes catalytic oligomerisation either of the homogeneous liquid phase type, or of the heterogeneous type with a solid support. The effluent produced is generally sent to a heat exchanger traversed by a cold liquid, the effluent thus being cooled before being sent to a second reaction zone where it undergoes catalytic oligomerisation in a liquid—liquid two-phase medium, the invention being characterized in that at least an ethylenic hydrocarbon containing 3 to 5 carbon atoms per molecule is added to the inlet to the second reaction zone.

Abstract: The invention relates to a complex of ruthenium of the structural formula I, where X1 and X2 are identical or different and are each an anionic ligand, R1 and R2 are identical or different and can also contain a ring, and R1 and R2 are each hydrogen or/and a hydrocarbon group, the ligand L1 is an N-heterocyclic carbene and the ligand L2 is an uncharged electron donor, in particular an N-heterocyclic carbene or an amine, imine, phosphine, phosphite, stibine, arsine, carbonyl compound, carboxyl compound, nitrile, alcohol, ether, thiol or thioether, where R1, R2, R3 and R4 are hydrogen or/and hydrocarbon groups.

Abstract: A catalyst composition for use in dimerizing, co-dimerizing or oligomerizing olefins results from dissolving a nickel compound, optionally mixed or complexed with a ligand, in a medium resulting from mixing:

Abstract: Deaminatively generated carbocations to initiate addition polymerization are disclosed. The high reactivity of the carbocation allows initiation of polymerization with virtually all alkenes, alkynes, alicyclic and aromatic monomers, regardless whether multisubstituted or conjugated. In addition, the carbocation initiates a polymerization reaction that generates an extremely high molecular weight polymer. In particular polystyrene of viscosity average molecular weight of approximately 106 was obtained.

Abstract: Non-symmetrical ligands of formula (I); 1

Abstract: A catalyst comprising A) a stationary acid component selected from the group consisting of a perfluorinated ion exchange polymer on an inert support, a silane modified perfluorosulfonic acid, and a sulfated metal oxide; and B) a mobile acid component selected from the group consisting of chlorosulfonic acid, fluorosulfonic acid, a fluorinated monosulfonic acid, a fluorinated sulfonimide, a fluorinated disulfonic acid, and an adjunct acid mixture is disclosed.

Abstract: Mixed bis-imine pyridine ligands of formula (I), wherein Z1, which is different from Z2, is an optionally substituted aryl group; and Z2 comprises an optionally substituted heterohydrocarbyl moiety, or an optionally substituted aryl group in combination with a metal, said optionally substituted aryl group being &pgr;-co-ordinated to the metal; 1

Abstract: A manufacturing process for &agr;-olefins using certain iron containing ethylene oligomerization catalysts together with alkylaluminum cocatalysts, in which using a low ratio of Al:Fe in the process results in a lowered formation of undesired polyethylene waxes and polymer. This results in less fouling of the process lines and vessels in the manufacturing plant.

Abstract: An efficient manufacturing process for &agr;-olefins using certain iron containing ethylene oligomerization catalysts, comprises one or more liquid full reactors which are approximately at the bubble point of reacting ethylene, and optionally a final reactor which is at a lower pressure than the first reactor, both operating under other specified conditions. This process minimizes both the capital and operating costs for the plant. The &agr;-olefins produced are useful as monomers for polymers and as chemical intermediates, for example for making detergents.

Abstract: This invention relates to a method to oligomerize ethylene comprising combining ethylene with a catalyst system comprising an activator and one or more phenoxide group metal compounds represented by the formula: wherein R3, R4, R5, R8, R9 and R10 may each independently be hydrogen, a halogen, a heteroatom containing group or a C1 to C100 group, provided that at least one of these groups has a Hammett &sgr;p value (Hansch, et al Chem. Rev. 1991, 91, 165) greater than 0.20; R2 and R7 may each independently be alkyl, aryl or silyl groups; R1 and R6 may each independently be an alkyl group, an aryl group, an alkoxy group, or an amino group; N is nitrogen; H is hydrogen; O is oxygen; M is a group 4 transition metal; and each X may each independently be an anionic ligand or a dianionic ligand.

Abstract: Reaction mixtures and methods using catalysts and reaction conditions to produce significantly improved yields (and thereby higher purity) of olefin metathesis products, with greatly reduced amounts of impurities. These techniques include in one instance reduction in temperature of reaction, and in another, the use of chemical compounds that act as reaction inhibitors of unwanted reactions to minimize or prevent formation of unwanted impurities.

Abstract: The invention is directed towards a composition comprising the formula LMX(X′)n wherein n equals 0 or 1; X and X′ are independently selected from the group consisting of halides, hydride, triflate, acetates, borates, C1 through C12 alkyl, C1 through C12 alkoxy, C3 through C12 cycloalkyl, C3 through C12 cycloalkoxy, aryl, thiolates, carbon monoxide, cyanate, olefins, and any other moiety into which a monomer can insert; M is selected from the group consisting of nickel, palladium, and platinum and L is a nitrogen-containing bidentate ligand with more than two nitrogen atoms. The composition possesses a tetrahedral or pseudo-tetrahedral structure. The invention also provides a method for using the composition in conjunction with an activating cocatalyst to form short chain &agr;-olefins.

Abstract: In order to carry out selective dimerization of propylene principally into branched dimers, a catalytic composition resulting from at least partly dissolving a nickel compound mixed or complexed with a tertiary phosphine carrying a functional group is used in a medium resulting from mixing at least one quaternary ammonium halide and/or at least one quaternary phosphonium halide, at least one aluminum halide and optionally at least one organometallic aluminum compound.

Abstract: The present invention intends to provide an ethylene/&agr;-olefin copolymer of specific structure, exhibiting excellent performance as a lubricant oil additive, capable of having various functional groups in high ratio, and serviceable as raw material for various solubilizing agents. The ethylene/&agr;-olefin copolymer of the present invention is composed of ethylene and an &agr;-olefin having 3 to 10 carbon atoms, and characterized by specific characteristics.

Abstract: A process for oligomerising olefins in an organic feed containing at least one olefin comprises two steps with different types of catalysis. The cut to be treated containing at least one olefin (Cn) is introduced via line 1 into a reaction zone R1 where in a first step it undergoes catalytic oligomerisation, either of a liquid phase homogeneous type, or heterogeneous with a solid support. The effluent produced is sent via line 2 to a heat exchanger E1 traversed by a cold liquid. The effluent is thus cooled before being sent via line 3 to a second reaction zone R2 where it undergoes catalytic oligomerisation in a liquid-liquid two-phase medium. After reaction, the effluent is fed via line 4 to a zone L1 where it is washed. After washing, the hydrocarbon fraction is sent via line 5 to separator S1.

Abstract: Ethylene is oligomerized with certain catalysts based on iron and cobalt complexes of 2,6-pyridinecarboxaldehydebis(imine) and 2,6-diacylpyridine-bis(imine) tridentate ligands.

Abstract: An oligomerization process for the production of higher aliphatic olefins is disclosed. In the process, a liquid oligomerization feed stream comprising lighter aliphatic olefins is passed to a reactor vessel. The liquid oligomerization feed stream is transported upwardly in the reactor vessel against gravity through a fixed bed of solid oligomerization catalyst under oligomerization conditions. The catalyst has a Hammett acidity value of −4 or less. A liquid saturate stream comprising paraffins is passed into contact with the feed stream and the catalyst. A liquid oligomerization effluent stream is recovered comprising the paraffins and product higher aliphatic olefins.

Abstract: A process is described for carrying out olefin oligomerisation in two catalysis steps of different types, using an organic feed containing at least one olefin. The cut to be treated, containing at least one olefin (Cn), is introduced into a first reaction zone where, in a first step, it undergoes catalytic oligomerisation either of the homogeneous liquid phase type, or of the heterogeneous type with a solid support. The effluent produced is generally sent to a heat exchanger traversed by a cold liquid, the effluent thus being cooled before being sent to a second reaction zone where it undergoes catalytic oligomerisation in a liquid-liquid two-phase medium, the invention being characterized in that at least an ethylenic hydrocarbon containing 3 to 5 carbon atoms per molecule is added to the inlet to the second reaction zone.

Abstract: The invention is a method and catalyst for selectively and efficiently producing short chain linear &agr;-olefins. The method includes contacting olefinic monomers under oligomerization conditions with the catalyst composition which comprises a composition prepared in situ by reacting a nickel compound selected from the group consisting of halides, hydrides, triflates, acetates, borates, C1, through C12 alkyl, C1 through C12 alkoxy, C3 through C12 cycloalkyl, C3 through C12 cycloalkoxy, aryl, thiolates, carbon monoxide, cyanate, olefins including diolefins and cycloolefins, and any other moiety into which a monomer can insert and mixtures thereof, with an amine ligand wherein said ligand is a nitrogen-containing ligand having one or more nitrogen atoms.

Abstract: An efficient manufacturing process for &agr;-olefins using certain iron containing ethylene oligomerization catalysts, comprises one or more liquid full reactors which are approximately at the bubble point of reacting ethylene, and optionally a final reactor which is at a lower pressure than the first reactor, both operating under other specified conditions. This process minimizes both the capital and operating costs for the plant. The &agr;-olefins produced are useful as monomers for polymers and as chemical intermediates, for example for making detergents.

Abstract: A process for oligomerization of C4 and C5 isoolefins or the etherification thereof with C1 to C6 alcohols wherein the reactants are contacted first in a partial liquid phase reactor (boiling point reactor) with a fixed bed acid cation exchange resin catalyst at an LHSV of 5 to 20, pressure of 0 to 400 psig and temperature of 120 to 300° F., at a pressure to maintain the reaction mixture at its boiling point whereby at least a portion but less than all of the reaction mixture is vaporized and the entire reaction stream is directed to a catalytic distillation column reactor for further reaction of the reactants, where the improvement is having a decoupling drum between the boiling point reactor and the catalytic distillation column reactor. The addition of a decoupler drum allows the reactors to operate at a pressure independent of each other.

Abstract: A process for carrying out a reaction on an organic feed, for example dimerization, co-dimerization, oligomerization or metathesis of olefins, as described in which the catalyst is a catalytic metal compound dissolved in a non-aqueous ionic medium which is not or is only slightly miscible with hydrocarbons. The reaction is carried out in a system comprising at least two treatment loops each comprising at least one reaction zone and at least one zone for separating the organic and polar phases between which the polar medium containing the catalytic metal compound, and the organic phase circulate. Fresh polar phase is injected into the second loop and used polar phase is eliminated from the first loop. The hydrocarbon to be transformed is injected into the first loop and the products are withdrawn from the second loop. The invention also concerns a unit for carrying out the process.

Abstract: A catalyst and a process are provided for oligomerizing ethylene. A heterogeneous catalyst system comprises: (1) a chelating ligand, preferably 2-diphenyl phosphino benzoic acid (DPPBA); (2) a nickel precursor, preferably nickel chloride hexahydrate (NiCl2.6H2O); (3) a catalyst activator, preferably sodium tetraphenylborate (NaBPh4); and (4) silica. A 1:1:1 molar ratio of Ni:DPPBA:BPh4 catalyst components are fixed on a silica support using low-temperature fixation. The catalyst components are dispersed in a diluent, preferably ethanol, and silica is added. The ethanol is evaporated using freeze-drying equipment to form a silica-supported catalyst system. The silica-supported catalyst is slurried in ethanol in a reactor, and ethylene is added. The reactor pressure and temperature are maintained at about 725 psig and 100° C., respectively, for about two hours.

Abstract: A process for producing an .alpha.-olefin oligomer, comprising subjecting an .alpha.-olefin to oligomerization in a reaction solution containing a chromium-based catalyst produced by bringing at least a chromium compound (a), a pyrrole ring-containing compound (b), an alkyl aluminum compound (c) and a halogen-containing compound (d) into contact with each other, wherein the chromium-based catalyst is a catalyst produced by bringing the pyrrole ring-containing compound (b), the alkyl aluminum compound (c) and the halogen-containing compound (d) into contact with each other in a hydrocarbon and/or halogenated hydrocarbon solvent, and then bringing the resultant mixed solution into contact with the chromium compound (a); or a catalyst produced by bringing the chromium compound (a), the pyrrole ring-containing compound (b), the alkyl aluminum compound (c) and the halogen-containing compound (d) into contact with each other in a hydrocarbon and/or halogenated hydrocarbon solvent in the absence of .alpha.

Abstract: The present invention provides a novel catalyst system which can be preferably used in the trimerization, oligomerization reaction or polymerization reaction of an olefin, and a method for the trimerization, oligomerization or polymerization reaction of an olefin, which comprises using the catalyst system. A catalyst system obtained by contacting the following components (A) to (C):(A) a chromium compound,(B) an imine compound, and(C) a metal alkyl compound, and a method for the trimerization, oligomerization or polymerization reaction of an olefin, which comprises using the catalyst system are disclosed.

Abstract: Alpha-olefins are manufactured in high yield and with very high selectivity by contacting ethylene with an iron complex of a selected 2,6-pyridinedicarboxaldehyde bisimine or a selected 2,6-diacylpyridine bisimine, and in some cases a selected activator compound such as an alkyl aluminum compound. Novel bisimines and their iron complexes are also disclosed. The .alpha.-olefins are useful as monomers and chemical intermediates.

Abstract: Functionalized cyclic olefins and methods for making the same are disclosed. Methods include template-directed ring-closing metathesis ("RCM") of functionalized acyclic dienes and template-directed depolymerization of functionalized polymers possessing regularly spaced sites of unsaturation. Although the template species may be any anion, cation, or dipolar compound, cationic species, especially alkali metals, are preferred. Functionalized polymers with regularly spaced sites of unsaturation and methods for making the same are also disclosed. One method for synthesizing these polymers is by ring-opening metathesis polymerization ("ROMP") of functionalized cyclic olefins. The metathesis catalysts for both RCM and ROMP reaction are ruthenium or osmium carbene complex catalysts of the formula ##STR1## where M is Os or Ru; R and R.sup.1 each may be hydrogen, C.sub.2 -C.sub.20 alkenyl, C.sub.2 -C.sub.20 alkynyl, C.sub.1 -C.sub.20 alkyl, aryl, C.sub.1 -C.sub.20 carboxylate, C.sub.1 -C.sub.20 alkoxy, C.sub.2 -C.sub.

Abstract: Propylene may be oligomerized by contact with cobalt complexes corresponding to the following structure: ##STR1## wherein R.sup.1 -R.sup.7 are hydrogen, hydrocarbyl or inert functional groups, and X is an anion. The resulting olefins are useful as chemical intermediates.

Abstract: Catalysts and processes are described to make low molecular weight, essentially terminally-unsaturated, viscous poly(1-olefin) or copoly(1-olefin) having a high terminal vinylidine content from a feed stock containing one or more 1-olefin and other volatile hydrocarbon liquids using a Ziegler catalyst made from a Group IVb metallocene and an aluminoxane cocatalyst, particularly bis(cyclopentadienyl) and bis(indenyl) titanium(IV), zirconium(IV) or hafnium(IV) compounds and methylaluminoxane. A particularly useful feed stock is a refinery stream containing 1-olefins and isobutylene which is used to make polyisobutylene.

Abstract: A method is provided for regenerating a fixed bed of olefin polymerization catalyst which can be performed without taking the catalyst bed out of service. The method involves the use of two different olefin-containing feedstocks, wherein the first feedstock is a conventional olefin-containing feedstock which contains little if any content of aromatic compounds. The second feedstock contains a significant concentration of aromatic compounds. In the practice of the invention, the second feedstock is substituted for the first feedstock whenever catalyst regeneration is deemed appropriate, and the flow of the second feedstock to the catalyst bed is continued for a period of time which is effective to at least partially regenerate the catalyst.

Abstract: A process to maximize the production of low molecular weight alpha olefins from ethylene is disclosed. The process comprises oligomerizing ethylene in the presence of a catalyst, of titanium aryloxide and/or titanium alkoxide; alkyl aluminum halide and triaryl phosphine and/or trialkyl phosphine in the temperature range of 80.degree. C. to 110.degree. C. at substantially low pressures of from 60 to 150 psi. A continuous supply of ethylene is maintained.

Abstract: A process for the continuous oligomerization of ethylene to produce linear alpha olefins by oligomerizing ethylene in a polar phase comprising a solution of transition metal catalyst system at oligomerization conditions including a temperature and pressure greater than the critical temperature and pressure of ethylene. The resulting hydrocarbon phase containing oligomers and unreacted ethylene is subjected to physical treatment which tends to render the ethylene a nonsolvent for oligomers and thereby produce a liquid stream rich in unreacted ethylene which may be recycled to the oligomerization reaction zone by pumping.

Abstract: A process for the preparation of halogen-free, reactive polyisobutene having a content of terminal double bonds of more than 50 mol % and an average molecular weight M.sub.n of from 500 to 5000 dalton by the cationic polymerization of isobutene or isobutene-containing hydrocarbon mixtures in the liquid phase, wherein the polymerization is carried out at a temperature of from -30.degree. to +40.degree. C. over a heterogeneous polymerization catalyst containing at least one element acting as promoter and selected from Group IB, Group IIB, Group IIIB, Group IVB, Group VB, Group VIIB, or Group VIIIB of the Periodic Table or from Group IIA, Group IIIA, Group IVA, Group VA, or Group VIA of the Periodic Table or a number of said elements in each case in the form of an oxygen-containing compound and zirconium in the form of an oxygen-containing compound, said polymerization catalyst containing no industrially effective amounts of halogens.

Abstract: A method is provided which can be used to quickly and easily take a fixed-bed of solid acid olefin polymerization catalyst out of service without causing any significant catalyst deactivation. The method involves substituting a substantially olefin-free hydrocarbon fluid for at least a portion of the olefin-containing feedstock to the polymerization process, wherein the substantially olefin-free hydrocarbon fluid boils within the range from about 20.degree. to about 250.degree. C. and contains at least about 5 vol. % aromatics.

Abstract: Alpha-olefin oligomers are produced by oligomering alpha-olefin monomer with a catalyst system comprising boron trifluoride, a protic promoter, and a special type of modifier. The modifier is a compound that satisfies the following criteria: (a) it has at least one moiety in which a carbonyl group is directly bonded to a nitrogen atom which is in turn bonded to two separate carbon atoms, (b) it is devoid of any nitrogen atom other than a nitrogen atom that is either (i) directly bonded to two separate carbon atoms and to a carbonyl group or (ii) is triply bonded to a single carbon atom, and (c) it is devoid of any protonic functional substituent. These modifiers control the oligomer product distribution and provide higher percentages of lower oligomers, especially dimers.

Abstract: The disclosure described a process for producing an .alpha.-olefin oligomer, which comprises carrying out oligomerization of an .alpha.-olefin in a solvent in the presence of a catalytically effective amount of a chromium-based catalyst system composed of a combination of at least (a) a chromium compound, (b) a nitrogen-containing compound of at least one selected from the group consisting of an amine, an amide and an imide, (c) an alkylaluminum compound and (d) a halogen-containing compound,wherein each of the .alpha.-olefin, the chromium compound (a), the nitrogen-containing compound (b) of at least one selected from the group consisting of an amine, an amide and an imide, the alkylaluminum compound (c) and the halogen-containing compound (d) is supplied to a reaction system in a mode that the chromium compound (a) and the alkylaluminum compound (c) do not contact each other before each of said compounds (a) to (d) and the .alpha.-olefin coexists in the reaction solvent and the oligomerization of an .alpha.

Abstract: Disclosed herein are processes for polymerizing ethylene, acyclic olefins, and/or selected cyclic olefins, and optionally selected olefinic esters or carboxylic acids, and other monomers. The polymerizations are catalyzed by selected transition metal compounds, and sometimes other co-catalysts. Since some of the polymerizations exhibit some characteristics of living polymerizations, block copolymers can be readily made. Many of the polymers produced are often novel, particularly in regard to their microstructure, which gives some of them unusual properties. Numerous novel catalysts are disclosed, as well as some novel processes for making them. The polymers made are useful as elastomers, molding resins, in adhesives, etc. Also described herein is the synthesis of linear .alpha.-olefins by the oligomerization of ethylene using as a catalyst system a combination a nickel compound having a selected .alpha.-diimine ligand and a selected Lewis or Bronsted acid, or by contacting selected .alpha.

Abstract: The present invention relates to a process for producing an .alpha.-olefin oligomer by subjecting .alpha.-olefin to oligomerization in a reaction zone in the presence of a reaction solution containing a chromium-based catalyst, which comprises,continuously conducting said oligomerization of .alpha.-olefin by using said chromium-based catalyst comprising at least a chromium compound (a), a nitrogen-containing compound (b) selected from the group consisting of amines, amides and imides, and an alkyl aluminum compound (c) while maintaining a molar ratio of the .alpha.-olefin oligomer to .alpha.-olefin in the range of 0.05 to 1.00.

Abstract: The invention concerns an improved process for the conversion of ethylene into light alpha olefins wherein the ethylene is brought into contact with a catalyst obtained by mixing a compound of zirconium with an organic compound selected from the class of acetals and ketals, esters, ketones, ethers, amines, nitrites, anhydrides, chlorides of acids, amides, aldehydes, thioethers, sulphides and disulphides, thiophenes, thioureas and phosphines, and with a chloro or bromo compound of aluminium hydrocarbyl, in the presence of an additive formed by at least one quaternary ammonium salt.

Abstract: Ethylene is trimerized to form 1-hexene by using a catalyst comprising an aluminoxane and polydentate phosphine, arsine, and/or stibine coordination complex of a chromium salt. Catalysts, complexes, and ligands enabling production of 1-hexene in extremely high yields and purity are also described.