KR102026889B1

KR102026889B1 - Ligand compound, organic chromium compound, catalyst system for oligomerization of olefins and method for oligomerization of olefins using the catalyst system

Info

Publication number: KR102026889B1
Application number: KR1020150112517A
Authority: KR
Inventors: 신은지; 이기수; 이용호; 손경선; 박종은
Original assignee: 주식회사 엘지화학; 충남대학교산학협력단
Priority date: 2015-08-10
Filing date: 2015-08-10
Publication date: 2019-09-30
Also published as: KR20170018636A

Abstract

The present invention relates to a ligand compound, a catalyst system for olefin oligomerization and a method for oligomerization of olefins using the same. The ligand compound according to the present invention can be applied to a catalyst system for olefin oligomerization to exhibit improved 1-hexene selectivity and catalytic activity.

Description

Ligand compound, organochrome compound, catalyst system for olefin oligomerization, and method for oligomerization of olefin using the same

The present invention relates to a ligand compound, an organochrome compound, a catalyst system for olefin oligomerization comprising the ligand compound or organochrome compound, and a method for oligomerization of olefins using the same.

Linear alpha-olefins such as 1-hexene and 1-octene are used as detergents, lubricants, plasticizers, etc., and are particularly used as comonomers for controlling the density of polymers in the production of linear low density polyethylene (LLDPE). Used.

These linear alpha-olefins were produced primarily through the Shell Higher Olefin Process. However, since the method synthesizes alpha-olefins of various lengths simultaneously according to the Schultz-Flory distribution, it is cumbersome to undergo a separate separation process in order to obtain specific alpha-olefins.

In order to solve this problem, a method of selectively synthesizing 1-hexene through trimerization of ethylene or selectively synthesizing 1-octene through tetramerization of ethylene has been proposed. Many studies have been made on catalyst systems that enable the oligomerization of such selective ethylene.

However, oligomerization catalyst systems of olefins to date have not had sufficient catalytic activity and selectivity for alpha-olefins. In addition, the previous catalyst system is not able to sufficiently secure the production efficiency of the polyolefin wax, the situation is required to compensate for this.

The present invention is to provide a novel ligand compound capable of exhibiting improved 1-hexene selectivity and catalytic activity in the oligomerization reaction of olefins.

In addition, the present invention is to provide a novel chromium complex that can exhibit improved 1-hexene selectivity and catalytic activity in the oligomerization reaction of olefins.

In addition, the present invention is to provide a catalyst system for olefin oligomerization comprising the ligand compound or chromium complex compound.

The present invention also provides a method for oligomerization of olefins using the catalyst system.

According to the present invention, there is provided a ligand compound represented by the following formula (1):

[Formula 1]

In Chemical Formula 1,

N is nitrogen;

B is phosphorus (P), arsenic (As) or antimony (Sb);

R ¹ to R ¹⁴ are each independently hydrogen, a C 1-10 hydrocarbyl group or a hetero hydrocarbyl group,

At least one of R ¹ to R ⁴ , at least one of R ⁵ to R ⁹ , or at least one of R ¹⁰ to R ¹⁴ are each independently a C 1-10 hydrocarbyl group or hetero hydrocarbyl group, or

The R ⁹ and R ¹⁰ are connected to form a single bond and the remaining group is hydrogen.

In addition, according to the present invention, a complex compound in which a chromium compound is coordinated with the ligand compound is provided.

And, according to the present invention, i) a chromium source, the ligand compound and a promoter; Or ii) an olefin oligomerization catalyst system comprising the complex and a cocatalyst.

In addition, according to the present invention, there is provided a method for oligomerization of olefins comprising the step of multimerizing olefins in the presence of the catalyst system.

Hereinafter, a ligand compound, a chromium complex compound, a catalyst system for olefin oligomerization, and a method for oligomerization of olefins using the same according to embodiments of the present invention will be described in more detail.

Prior to this, the terminology is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention unless explicitly stated throughout this specification.

As used herein, the singular forms “a,” “an” and “the” include plural forms as well, unless the phrases clearly indicate the opposite.

In addition, the meaning of "include" as used herein specifies a particular characteristic, region, integer, step, operation, element and / or component, and other specific characteristics, region, integer, step, operation, element, component and / or It does not exclude the presence or addition of groups.

In the present specification, the term 'catalyst system' refers to a three component including a chromium source, a ligand compound and a promoter, or alternatively, two components of the chromium complex and the promoter are added simultaneously or in any order to increase activity. It means the state which can be obtained with the catalyst composition which exists. Three or two components of the catalyst system may be added in the presence or absence of a solvent and monomer, and may be used in a supported or unsupported state.

I. Ligand Compounds

According to one embodiment of the invention, there is provided a ligand compound represented by the following formula (1):

[Formula 1]

In Chemical Formula 1,

N is nitrogen;

B is phosphorus (P), arsenic (As) or antimony (Sb);

As a result of continuous studies by the present inventors, it was confirmed that when the ligand compound represented by Chemical Formula 1 is applied to a catalyst system for oligomerization of olefins, it can exhibit improved 1-hexene selectivity and catalytic activity.

The ligand compound is compared with the compound which is not substituted as substituents are introduced into at least one of the R ¹ to R ⁴ , at least one of the R ⁵ to R ⁹ , or at least one of the R ¹⁰ to R ¹⁴ in Formula 1 It can exhibit a significant difference between the electronic and three-dimensional effect. Due to this property, in particular, the ligand compound can exhibit high 1-hexene selectivity as well as high catalytic activity even under low olefin pressure.

In Formula 1, B may be phosphorus (P), arsenic (As) or antimony (Sb), and preferably phosphorus (P).

In addition, in Formula 1, R ¹ to R ¹⁴ are each independently hydrogen, a C 1-10 hydrocarbyl group, or a hetero hydrocarbyl group; At least one of R ¹ to R ⁴ , at least one of R ⁵ to R ⁹ , or at least one of R ¹⁰ to R ¹⁴ are each independently a C 1-10 hydrocarbyl group or hetero hydrocarbyl group, or The R ⁹ and R ¹⁰ are connected to form a single bond and the remaining group is hydrogen.

Preferably, at least one of R ¹ to R ⁴ , at least one of R ⁵ to R ⁹ , or at least one of R ¹⁰ to R ¹⁴ each independently represent a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms. , Substituted or unsubstituted cycloalkyl group having 4 to 10 carbon atoms, substituted or unsubstituted aryl group having 6 to 10 carbon atoms, substituted or unsubstituted arylalkyl group having 7 to 10 carbon atoms, or substituted or unsubstituted carbon atom 1 to 10 It may be an alkoxy group. Here, at least one hydrogen contained in the alkyl group, cycloalkyl group, aryl group, arylalkyl group, and alkoxy group may be substituted with an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, a halogen atom, or a cyano group. .

Preferably, each of R ¹ to R ⁴ may be hydrogen; At least one of the R ⁵ to R ⁹ and at least one of the R ¹⁰ to R ¹⁴ are each independently methyl, ethyl, propyl, propenyl, propynyl, Butyl, trifluoromethyl, cyclohexyl, 2-methylcyclohexyl, 2-ethylcyclohexyl, 2-isopropylcyclohexyl (2- isopropylcyclohexyl, benzyl, phenyl, tolyl, xylyl, o-methylphenyl, o-ethylphenyl, o-isopropylphenyl (o -isopropylphenyl, ot-butylphenyl, o-methoxyphenyl, o-isopropoxyphenyl, cumyl, mesityl, biphenyl (biphenyl), naphthyl, anthracenyl, methoxy, ethoxy, phenoxy, tolyloxy, dimethylamino, thiomethyl ), Or a trimethylsilyl group.

The ligand compound can be represented by the following examples:

;

;

;

;

;

;

;

;

;

;

;

;

;

;

;

;

;

;

.

In addition to the representative examples, the ligand compound may have various structures in the above-described range.

In addition, the ligand compound may be synthesized according to, for example, the following scheme.

[Scheme]

In the scheme, X is halogen, Et ₃ N is triethylamine, THF is tetrahydrofuran.

More detailed synthetic methods for such ligand compounds are described in the Examples section.

II. Complex

Meanwhile, according to another embodiment of the present invention, a complex compound in which a chromium compound is coordinated with the ligand compound described above is provided.

The complex compound is a chromium complex compound of the ligand compound described above, and may have a form in which two ligand compounds and chromium (Cr) of a chromium source form a coordination bond.

As a non-limiting example, the complex may be represented by the following Chemical Formula 2:

[Formula 2]

In Chemical Formula 2,

N is nitrogen;

B is phosphorus (P), arsenic (As) or antimony (Sb);

R ¹ to R ¹⁴ are each independently hydrogen, a hydrocarbyl group or heterohydrocarbyl group having 1 to 10 carbon atoms; At least one of R ¹ to R ⁴ , at least one of R ⁵ to R ⁹ , or at least one of R ¹⁰ to R ¹⁴ are each independently a C 1-10 hydrocarbyl group or hetero hydrocarbyl group, or R ⁹ and R ¹⁰ are joined to form a single bond, and the remaining groups are hydrogen;

Cr is chromium;

Y ¹ to Y ³ are each independently halogen, hydrogen, oxygen, or a hydrocarbyl group having 1 to 10 carbon atoms.

Such chromium complexes can be synthesized by conventional methods for preparing the ligand compounds.

In addition, the complex may be applied to a catalyst system for oligomerization of olefins to exhibit improved 1-hexene selectivity and catalytic activity.

III. Olefin For oligomerization Catalyst system

According to another embodiment of the invention,

i) chromium sources, ligand compounds and cocatalysts described above; or

ii) the above complexes and promoters

Provided is a catalyst system for olefin oligomerization.

That is, the catalyst system for olefin oligomerization comprises: i) a three component catalyst system comprising a chromium source, the above-described ligand compound, and a promoter; Or ii) a two-component catalyst system comprising the complex and cocatalyst described above.

In the catalyst system, the chromium source is an organic or inorganic chromium compound in which the oxidation state of chromium is 0 to 6, for example, a chromium metal, or a compound in which any organic or inorganic radical is bonded to chromium. Here, the organic radical may be alkyl, alkoxy, ester, ketone, amido radical, etc. having 1 to 20 carbon atoms per radical, and the inorganic radical may be a halide, sulfate, oxide, or the like.

Preferably, the chromium source is a compound that can exhibit high activity in oligomerization of olefins and is easy to use and obtain, such as chromium (III) acetylacetonate, chromium (III) chloride tetrahydrofuran, chromium (III) 2 At least one compound selected from the group consisting of ethylhexanoate, chromium (III) acetate, chromium (III) butyrate, chromium (III) pentanoate, chromium (III) laurate, and chromium (III) stearate Can be.

In addition, the promoter included in the catalyst system may be any organometallic compound capable of activating a main compound included in the catalyst system. Preferably, the promoter is an organometallic compound including a Group 13 metal, and may be applied without particular limitation as long as it can be used when polymerizing olefins under a catalyst of a transition metal compound.

For example, the promoter may be at least one compound selected from the group consisting of compounds represented by the following Chemical Formulas 3 to 5:

[Formula 3]

-[Al (R ³¹ ) -O] _c-

In Formula 3, R ³¹ is the same as or different from each other, and each independently a halogen radical, a hydrocarbyl radical having 1 to 20 carbon atoms, or a hydrocarbyl radical having 1 to 20 carbon atoms substituted with halogen, c is an integer of 2 or more, and ,

[Formula 4]

D (R ⁴¹ ) ₃

In Formula 4, D is aluminum or boron, R ⁴¹ is a hydrocarbyl having 1 to 20 carbon atoms or a hydrocarbyl having 1 to 20 carbon atoms substituted with halogen,

[Formula 5]

[LH] ⁺ [Q (E) ₄ ] ^-

In Chemical Formula 5,

L is a neutral Lewis base, [LH] ⁺ is a Bronsted acid, Q is boron or aluminum in a +3 type oxidation state, each E is independently at least one hydrogen atom is halogen, a hydrocarbyl having 1 to 20 carbon atoms, An aryl group having 6 to 20 carbon atoms or an alkyl group having 1 to 20 carbon atoms which is unsubstituted or substituted with an alkoxy functional group or a phenoxy functional group.

According to one embodiment, the compound represented by Formula 3 may be alkyl aluminoxane, such as methyl aluminoxane, ethyl aluminoxane, isobutyl aluminoxane, butyl aluminoxane. In addition, the alkyl aluminoxane may be a modified alkyl aluminoxane (MMAO) mixed with two or more kinds.

According to one embodiment, the compound represented by Formula 4 is trimethylaluminum, triethylaluminum, triisobutylaluminum, tripropylaluminum, tributylaluminum, dimethylchloroaluminum, dimethylisobutylaluminum, dimethylethylaluminum, di Ethylchloroaluminum, triisopropylaluminum, triisobutylaluminum, tri-s-butylaluminum, tricyclopentylaluminum, tripentylaluminum, triisopentylaluminum, trihexylaluminum, ethyldimethylaluminum, methyldiethylaluminum, triphenyl Aluminum, tri-p-tolyl aluminum, dimethyl aluminum methoxide, dimethyl aluminum ethoxide, trimethyl boron, triethyl boron, triisobutyl boron, tripropyl boron, tributyl boron and the like.

Further, according to one embodiment, the compound represented by Formula 5 is triethylammonium tetraphenylboron, tributylammonium tetraphenylboron, trimethylammonium tetraphenylboron, tripropylammonium tetraphenylboron, trimethylammonium Tetra (p-tolyl) boron, tripropylammonium tetra (p-tolyl) boron, triethylammonium tetra (o, p-dimethylphenyl) boron, trimethylammonium tetra (o, p-dimethylphenyl) boron, tri Butyl ammonium tetra (p-trifluoromethylphenyl) boron, trimethyl ammonium tetra (p-trifluoromethylphenyl) boron, tributyl ammonium tetrapentafluorophenyl boron, N, N-diethylanilinium tetraphenyl Boron, N, N-diethylanilinium tetraphenylboron, N, N-diethylanilinium tetrapentafluorophenylboron, diethylammonium tetrapentafluorophenylboron, triphenylphosphonium tetraphenylboron,Limethyl phosphonium tetraphenyl boron, triethyl ammonium tetraphenyl aluminum, tributyl ammonium tetraphenyl aluminum, trimethyl ammonium tetraphenyl aluminum, tripropyl ammonium tetraphenyl aluminum, trimethyl ammonium tetra (p-tolyl) aluminum, Tripropylammonium tetra (p-tolyl) aluminum, triethylammonium tetra (o, p-dimethylphenyl) aluminum, tributylammonium tetra (p-trifluoromethylphenyl) aluminum, trimethylammonium tetra (p-tri Fluoromethylphenyl) aluminum, tributylammonium tetrapentafluorophenylaluminum, N, N-diethylanilinium tetraphenylaluminum, N, N-diethylanilinium tetraphenylaluminum, N, N-diethylaniyl Linium tetrapentafluorophenylaluminum, diethylammonium tetrapentafluorophenylaluminum, triphenylphosphonium tetraphenylaluminum, trimethylfo Phosphorus tetraphenylaluminum, triphenylcarbonium tetraphenylboron, triphenylcarbonium tetraphenylaluminum, triphenylcarbonium tetra (p-trifluoromethylphenyl) boron, triphenylcarbonium tetrapentafluorophenyl boron And so on.

In addition, the promoter may be an organoaluminum compound, an organoboron compound, an organomagnesium compound, an organozinc compound, an organolithium compound, or a mixture thereof.

For example, the promoter is preferably an organoaluminum compound, more preferably trimethyl aluminum, triethyl aluminum, triisopropyl aluminum, triisobutyl aluminum ), Ethylaluminum sesquichloride, diethylaluminum chloride, ethyl aluminum dichloride, methylaluminoxane, and modified methylaluminoxane It may be one or more compounds selected from the group.

Meanwhile, the content ratio of the components constituting the catalyst system may be determined in consideration of catalyst activity and selectivity for linear alpha-olefins. According to one embodiment, in the three component catalyst system, the molar ratio of ligand compound: chromium source: cocatalyst is about 1: 1: 1 to 10: 1: 10,000, or about 1: 1: 100 to 5: 1 It is advantageous to adjust to: 3,000. And, in the case of the two-component catalyst system, the molar ratio of the complex compound: promoter is advantageously controlled to be 1: 1 to 1: 10,000, or 1: 1 to 1: 5,000, or 1: 1 to 1: 3,000.

In addition, the catalyst system may further include a carrier. That is, the ligand compound and the complex compound may be applied to ethylene oligomerization in a form supported on a carrier. The carrier may be a metal, a metal salt, a metal oxide, or the like applied to a conventional supported catalyst. As a non-limiting example, the carrier may be silica, silica-alumina, silica-magnesia, and the like, and oxides, carbonates, sulfates, vaginas of metals such as Na ₂ O, K ₂ CO ₃ , BaSO ₄ , Mg (NO ₃ ) _2, and the like. It may comprise a trisalt component.

The components constituting the catalyst system can then be added simultaneously or in any order, in the presence or absence of suitable solvents and monomers, to act as a catalytic system having activity. At this time, a suitable solvent may be heptane, toluene, diethyl ether, tetrahydrofuran, acetonitrile, dichloromethane, chloroform, chlorobenzene, methanol, acetone and the like.

IV. Olefin Oligomerization Way

On the other hand, according to another embodiment of the present invention, there is provided a method for oligomerization of olefins comprising the step of multimerizing olefins in the presence of the catalyst system described above.

The process for oligomerization of olefins according to the invention can be carried out by applying the above-described catalyst system, conventional apparatus and contacting techniques with olefins (for example ethylene) as raw materials. As a non-limiting example, the oligomerization reaction of the olefin may be a homogeneous liquid phase reaction in the presence or absence of an inert solvent, or a slurry reaction in which the catalyst system is partially or completely insoluble, or the product alpha-olefin is the main medium. It can be carried out in a bulk phase reaction, or a gas phase reaction.

The oligomerization reaction of the olefin can be carried out under an inert solvent. As a non-limiting example, the inert solvent may be benzene, toluene, xylene, cumene, heptane, cyclohexane, methylcyclohexane, methylcyclopentane, n-hexane, 1-hexene, 1-octene and the like.

In addition, the oligomerization reaction of the olefin may be performed at a temperature of about 0 to 200 ℃, or about 0 to 150 ℃, or about 30 to 100 ℃, or about 50 to 100 ℃. In addition, the reaction may be carried out under a pressure of about 1 to 300 bar or 2 to 150 bar.

Ligand compounds and complex compounds according to the present invention can be included in the catalyst system for olefin oligomerization can exhibit improved 1-hexene selectivity and catalytic activity.

1 is an NMR spectrum of a ligand compound according to Synthesis Example 1. FIG.
2 is an NMR spectrum of a ligand compound according to Synthesis Example 2. FIG.
3 is an NMR spectrum of a ligand compound according to the control example.

Hereinafter, preferred embodiments will be presented to aid in understanding the invention. However, the following examples are only to illustrate the invention, not limited to the invention only.

Synthesis Example One

Pyrrole (20 mmol), triethylamine ( 20 mmol), and tetrahydrofuran (5 mL) for, chlorodi- the p -tolylphosphine (4.6 mmol) was dropwise at 0 ℃ addition, move to the Schlenk flask. The reaction was stirred at 0 ° C. for 30 minutes and then heated to room temperature for 30 minutes. After that, the reaction was performed while refluxing for 15 hours.

The resulting precipitate was filtered off and washed with THF, and the filtrate was dried under vacuum. After drying the filter, and rinsed and the resulting oil with hexane, purified by column chromatography to give 1- (di-p-tolylphosphino) -1 H -pyrrole. ¹ H NMR (CDCl ₃ ) spectra and ³¹ P NMR (CDCl ₃ ) spectra for the compounds are shown in FIG. 1.

Synthesis Example 2

Except for using bis (3,5-bis (trifluoromethyl) phenyl) chlorophosphine instead of chlorodi- p -tolylphosphine, 1- (bis (3,5-bis (trifluoromethyl) phenyl) phosphino)- 1 H -pyrrole was obtained. ¹ H NMR (CDCl ₃ ) spectra and ³¹ P NMR (CDCl ₃ ) spectra for the compounds are shown in FIG. 2.

Control

except that instead of diphenylphosphine chlorodi- p -tolylphosphine, and in the same manner as in Synthesis Example 1 1- (diphenylphosphino) -1 H -pyrrole was obtained a. ¹ H NMR (CDCl ₃ ) spectra and ³¹ P NMR (CDCl ₃ ) spectra for the compound are shown in FIG. 3.

Production Example One

A 125 mL Parr reactor equipped with a pressure controller was prepared. Methylcyclohexane (47 mL) and aluminum cocatalyst were added to the reactor. After saturation with nitrogen gas the solution was stirred for 15 minutes.

A catalyst solution containing chromium (III) acetylacetonate (0.01 mmol), a ligand (0.02 mmol) according to Synthesis Example 1, and methylcyclohexane (3 mL) was prepared.

When the catalyst solution was injected with ethylene gas into the reactor was considered a time zero. After 30 minutes, the reaction was terminated by stopping the ethylene feed and cooling the reactor (below 5 ° C).

After venting excess ethylene from the reactor, nonane (1 mL) was added as an internal standard for GC-FID analysis of the liquid phase. A small amount of the reaction solution was taken to confirm the distribution of oligomers by GC-FID analysis. A mixture of methanol and dilute HCl was added to the remaining reaction solution, and the solids were analyzed by stirring.

Production Example 2 to 6

As shown in Table 1 and Table 2, Preparation Example 1, except that the ligand according to Synthesis Example 2 or the control instead of the ligand according to Synthesis Example 1, respectively, and adjusted the ratio of the promoter and the pressure of ethylene In the same manner as the oligomerization of ethylene was carried out.

Preparation Example 1 Preparation Example 2 Preparation Example 3 Ligand Synthesis Example 1 Synthesis Example 2 Control Promoter
(DMAO eq / TiBAl eq to Cr) 500/50 500/50 500/50 Ethylene pressure (bar) 10 10 10 Catalytic activity (g / g Cr / hr) 214.1 582.7 232.2 Olefin
in liquid
(wt%) 1-C ₆ 94.7 96.3 88.3 1-C ₈ 2.4 0.8 3.2 C ₁₀ to C ₄₀ 1.5 0.5 1.0 Solid (wt%) 14.4 6.2 13.7

Preparation Example 4 Preparation Example 5 Preparation Example 6 Ligand Synthesis Example 2 Synthesis Example 2 Synthesis Example 2 Promoter
(DMAO eq / TiBAl eq to Cr) 500/50 500/100 100/500 Ethylene pressure (bar) 20 20 20 Catalytic activity (g / g Cr / hr) 1550 2200 1937 Olefin
in liquid
(wt%) 1-C ₆ 99.0 99.1 98.7 1-C ₈ 0.5 0.4 0.5 C ₁₀ to C ₄₀ 0.4 0.4 0.4 Solid (wt%) 4.8 3.2 1.8

Referring to Tables 1 and 2 above, Preparation Example 1, in which the compound of Synthesis Example 1 was applied as a ligand, showed improved catalytic activity, and improved 1-hexene selectivity, compared to Preparation Example 3, in which the compound of Comparative Example was used as a ligand. Indicated.

In particular, Preparation Example 2 showed more than twice the improved catalytic activity and high 1-hexene selectivity compared to Preparation Example 3. In the case of Preparation Examples 4 to 6, it was confirmed that the catalyst activity and 1-hexene selectivity were significantly improved by increasing the pressure of ethylene and changing the composition of the promoter.

Claims

Ligand compound represented by the following formula (1):
[Formula 1]

In Chemical Formula 1,
N is nitrogen;
B is phosphorus (P), arsenic (As) or antimony (Sb);
R ¹ to R ¹⁴ are each independently hydrogen, a C 1-10 hydrocarbyl group or a hetero hydrocarbyl group,
R ¹ to R ⁴ are each hydrogen,
At least one of R ⁵ to R ⁹ , or at least one of R ¹⁰ to R ¹⁴ is each independently a hydrocarbyl group or heterohydrocarbyl group having 1 to 10 carbon atoms, or
The R ⁹ and R ¹⁰ are connected to form a single bond and the remaining group is hydrogen.

The method of claim 1,
Wherein B is phosphorus (P), ligand compound.

The method of claim 1,
At least one of the R ⁵ to R ⁹ , or at least one of the R ¹⁰ to R ¹⁴ are each independently an alkyl group having 1 to 10 carbon atoms, a cycloalkyl group having 4 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, and 7 carbon atoms. As an arylalkyl group of 10 to 10, an alkoxy group of 1 to 10 carbon atoms,
At least one hydrogen contained in the alkyl group, the cycloalkyl group, the aryl group, the arylalkyl group, and the alkoxy group is unsubstituted or substituted with an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, a halogen atom, or a cyano group Phosphorus, ligand compounds.

A complex compound in which a chromium compound is coordinated with a ligand compound according to claim 1.

i) a chromium source, the ligand compound according to claim 1 and a promoter; or
ii) complexes and promoters according to claim 4
Catalyst system for olefin oligomerization comprising a.

The method of claim 5,
The chromium source is chromium (III) acetylacetonate, chromium (III) chloride tetrahydrofuran, chromium (III) 2-ethylhexanoate, chromium (III) acetate, chromium (III) butyrate, chromium (III) pentano A catalyst system for olefin oligomerization, which is at least one compound selected from the group consisting of eight, chromium (III) laurate, and chromium (III) stearate.

The method of claim 5,
The promoter is trimethyl aluminum, triethyl aluminum, triisopropyl aluminum, triisobutyl aluminum, ethyl aluminum sesquichloride, diethyl aluminum A catalyst system for olefin oligomerization, which is at least one compound selected from the group consisting of chloride, ethyl aluminum dichloride, methylaluminoxane, and modified methylaluminoxane.

A process for oligomerization of olefins comprising multimerizing the olefins in the presence of a catalyst system according to claim 5.

The method of claim 8,
The step is carried out under the temperature of 0 to 200 ℃ and a pressure of 1 to 300 bar oligomerization method.

The method of claim 8,
And said olefin is ethylene.