KR102185162B1 - Chromium complex, ethylene oligomerization catalyst system using the same and manufacturing method for ethylene oligomer - Google Patents

Abstract

The present invention relates to a chromium compound composed of a non-coordinating anion and a chromium trivalent cation, an ethylene oligomerization catalyst system using the same, and a method for producing an ethylene oligomer using the catalyst system. Through this, the present invention omits the use of methylaluminoxane (MAO) or modified-methylaluminoxane (MMAO), and improves the activity and selectivity of the ethylene oligomerization reaction to a remarkably excellent level, so that 1-hexene and 1- It provides a chromium compound capable of producing octene in high yield, suitable for mass commercial processes, and compatible with extremely high activity and excellent economics, an ethylene oligomerization catalyst system using the same, and a method for producing an ethylene oligomer.

Description

Chromium compound, ethylene oligomerization catalyst system using the same, and ethylene oligomer production method {CHROMIUM COMPLEX, ETHYLENE OLIGOMERIZATION CATALYST SYSTEM USING THE SAME AND MANUFACTURING METHOD FOR ETHYLENE OLIGOMER}

The present invention is suitable for mass production and commercial processes, can achieve both extremely high activity and excellent economics, and improves the selectivity of ethylene oligomerization reaction to produce 1-hexene and 1-octene in high yield. It relates to a compound, an ethylene oligomerization catalyst system using the same, and a method for producing an ethylene oligomer.

Ethylene oligomers 1-hexene and 1-octene are compounds that are used in large quantities as comonomers in polymerization of polyolefins such as polyethylene. In recent years, as the production of polyolefins using a homogeneous metallocene catalyst increases, the demand for 1-hexene and 1-octene among ethylene oligomers is steadily increasing.

In the conventional technique, by oligomerizing ethylene in the Shell Higher Olefin Process (SHOP) based on a nickel catalyst, various 1-alkenes having about 4 to about 30 carbon atoms are produced and 1-hexene from this And 1-octene could be obtained by separating separately. Subsequently, a catalyst system capable of producing 1-hexene or 1-hexene and 1-octene in high yield by increasing the selectivity in the ethylene oligomerization reaction was invented.

As an example, the catalyst system developed by Sassol is a chromium trivalent compound (CrCl ₃ or Cr(acac) ₃ ), a bisphosphine ligand (iPrN(PPh ₂ ) ₂ ) and crude It is composed of a catalyst, methylaluminoxane (MAO) or modified-methylaluminoxane (MMAO), and selectively produces 1-octene and 1-hexene (Patent Document 1 and Patent Document 2).

However, such a conventional catalyst system requires the use of a large amount of expensive MAO or MMAO in order to realize the level of activity that is commercially available, and the optimum activity temperature is low at about 60°C, and is an undesired polyethylene (PE) by-product. It has a weakness in its high production rate, which is an obstacle to commercialization.

Specifically, when the conventional catalyst system converts the activity to the activity relative to the input amount of MAO or MMAO, the practical commercial advantage is lowered by using a large amount of expensive MAO or MMAO. In addition, when the optimum activation temperature is as low as about 60°C, the control efficiency of reaction heat by air cooling or water cooling decreases rapidly, and even when only a relatively small amount of polyethylene by-products is produced, a balloon effect may occur, which may impair the advantages of mass production. .

For this reason, in recent years, efforts have been made to develop a catalyst system that does not use MAO or MMAO, has an optimum activation temperature of about 80°C, and can extremely reduce the production of polyethylene by-products. However, it is very difficult to achieve sufficiently high activity without using MAO or MMAO only with conventionally known techniques, and it is also very difficult to mass-produce such a highly active catalyst.

Therefore, the necessity of developing an ethylene oligomerization technology capable of producing 1-hexene and/or 1-octene with high selectivity and excellent productivity when contacted with an ethylene monomer is increased and that can achieve both high activity and economical efficiency. have.

(Prior technical literature)

Patent Document 1: Korean Laid-Open Patent Publication 10-2006-0002742

Patent Document 2: U.S. Patent Publication 7511183B2

Non-Patent Document 1: ACS Omega 2017, 2, 765

Non-Patent Document 2: Angewandte Chemie International Edition 2016, 55, 12351

An object of the present invention is to improve the activity and selectivity of the ethylene oligomerization reaction to a remarkably excellent level while omitting the use of methylaluminoxane (MAO) or modified-methylaluminoxane (MMAO) to achieve 1-hexene and 1-octene. It is to provide a chromium compound that can be prepared in high yield and a catalyst system using the same.

Another object of the present invention is to improve the activity and selectivity of the ethylene oligomerization reaction to a remarkably excellent level while omitting the use of methylaluminoxane (MAO) or modified-methylaluminoxane (MMAO). -It is to provide a method for producing an ethylene oligomer capable of producing octene in high yield, suitable for mass commercial processes, and compatible with extremely high activity and excellent economy.

All of the above and other objects of the present invention can be achieved by the present invention described below.

One embodiment of the present invention relates to a chromium compound represented by the following formula (1).

[Formula 1]

[(RN-{P(C ₆ H ₄ -pZ) ₂ } ₂ )-CrX ₂ ] ⁺ [AY ₄ ] ^-

In Formula 1, R is a substituted or unsubstituted alkyl group having 1 to 60 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 60 carbon atoms; Z is *-Si(R ¹ ) _3-n (R ² ) _n , wherein R ¹ and R ² are each independently an alkyl group having 1 to 25 carbon atoms, and n is 0 to 3 (however, *-Si( R ¹ ) _3-n (R ² ) the sum of carbon number of _n is 4 to 50); Each X is independently halogen, a carbosylate having 2 to 30 carbon atoms, an acetylacetonate, or a hydrocarbyl having 1 to 30 carbon atoms including or not including at least one of an ether group and an amine group; A is boron or aluminum; Y is aryl substituted with fluorine having 6 to 20 carbon atoms, aryloxy substituted with fluorine having 6 to 20 carbon atoms, or alkoxy substituted with fluorine having 1 to 20 carbon atoms.

Another embodiment of the present invention is a chromium compound represented by Formula 1; And it relates to an ethylene oligomerization catalyst system comprising an organic aluminum compound represented by the following formula (2).

[Formula 2]

(R ³ ) ₃ Al

In Formula 2, R ³ is an alkyl group having 1 to 20 carbon atoms.

In the catalyst system, the molar ratio of the chromium compound represented by Chemical Formula 1 and the aluminum compound represented by Chemical Formula 2 may be 1:50 to 1:500.

Another embodiment of the present invention relates to a method for producing an ethylene oligomer comprising the step of selectively preparing 1-hexene and 1-octene by contacting the above-described catalyst system with an ethylene monomer.

In the above embodiments, R in Formula 1 may be an isopropyl group.

In the above embodiments, X in Formula 1 may be Cl.

In the above embodiments, Z in Formula 1 is *-Si(R ¹ ) ₃ having 4 to 50 carbon atoms; Each of R ¹ may be independently ethyl, isopropyl, or n-butyl.

In the above embodiments, of Formula 1 [AY _4] ^- is _{[B (C 6 F 5)} 4] - can be.

In the above embodiments, R ³ in Formula 2 may be an isobutyl group or an ethyl group.

The present invention eliminates the use of methylaluminoxane (MAO) or modified-methylaluminoxane (MMAO), but improves the activity and selectivity of the ethylene oligomerization reaction to a remarkably excellent level, thereby reducing 1-hexene and 1-octene. A chromium compound that can be produced in a yield, is suitable for mass commercial processes, and can be compatible with extremely high activity and excellent economics, an ethylene oligomerization catalyst system using the same, and a method for producing an ethylene oligomer are provided.

1 shows the structure analyzed by X-ray crystallography of the chromium compound prepared in Example 5 of the present invention.
Figure 2 shows the ³¹ P NMR spectrum, ¹ H NMR spectrum, ¹⁹ F NMR spectrum, and EPR spectrum analysis results of the chromium compound prepared in Example 1 of the present invention.

In the present application, symbols such as H, B, C, N, O, F, P, Cr, Cl, and the like represented in the chemical formula mean an atom labeled by each element symbol unless otherwise stated.

In the present application,'*' indicated in the formula means a linking site in a chemical structure unless otherwise stated.

In the present application,'-' indicated in the formula means a bonding site in a chemical structure unless otherwise stated.

In the present application, Me represented in the formula is methyl, Et is ethyl, Pr is propyl, iPr is isopropyl, Bu is butyl, Ph is phenyl, acac is acetylacetonate, and THF is tetrahydrofuran.

<Chrome compound>

The chromium compound of one embodiment of the present invention is a novel chromium trivalent compound composed of a non-coordinating anion and a chromium trivalent cation, and is represented by the following formula (1).

[Formula 1]

[(RN-{P(C ₆ H ₄ -pZ) ₂ } ₂ )-CrX ₂ ] ⁺ [AY ₄ ] ^-

In Formula 1,

R is a substituted or unsubstituted alkyl group having 1 to 60 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 60 carbon atoms; Z is *-Si(R ¹ ) _3-n (R ² ) _n , wherein R ¹ and R ² are each independently an alkyl group having 1 to 25 carbon atoms, and n is 0 to 3 (however, *-Si( R ¹ ) _3-n (R ² ) the sum of carbon number of _n is 4 to 50); Each X is independently halogen, a carbosylate having 2 to 30 carbon atoms, an acetylacetonate, or a hydrocarbyl having 1 to 30 carbon atoms including or not including at least one of an ether group and an amine group; A is boron or aluminum; Y is aryl substituted with fluorine having 6 to 20 carbon atoms, aryloxy substituted with fluorine having 6 to 20 carbon atoms, or alkoxy substituted with fluorine having 1 to 20 carbon atoms.

For the reason that the chromium trivalent compound of Formula 1 generally takes 6 coordination, ether, sulfide, amine, nitrile, H ₂ O, etc. are additionally coordinated or the Cl ligand contained in Formula 1 is formed by two chromium atoms. It can exist as a compound in the form of a µ2-Cl dyneuglare that is shared to form a bridge. Ether, sulfide, amine, nitrile, H ₂ O ligand further coordinated with Formula 1 is decoordinated and removed when the alkylaluminum compound of Formula 2 is activated by contacting it, and the bridged Cl ligand is also a chemical formula It is converted into an alkyl group by the alkyl aluminum of 2 and has little effect on the implementation of the catalytic reaction.

1 is an exemplary chromium compound of Formula 1 according to the present invention (compound of Formula 1-4 of Example 5 [(iPrN[P(C ₆ H ₄ -p-Si(iPr)Et ₂ ] ₂ )-CrCl ₂ ] ⁺ [B(C ₆ F ₅ ) ₄ ] ^- ) shows the structure analyzed by X-ray crystallography. Referring to Fig. 1, the chromium compound of Formula 1 according to the present invention is nitrile It can be seen that the ligand is further coordinated to the chromium atom, and the Cl ligand is shared by two chromium atoms to form a bridge in the form of a μ2-Cl dinuclere.

Through this, the chromium compound of one embodiment of the present invention is applied to the ethylene oligomerization reaction, thereby omitting the use of methylaluminoxane (MAO) or modified-methylaluminoxane (MMAO), while reducing the activity and selectivity of the ethylene oligomerization reaction. By improving to a remarkably good level, 1-hexene and 1-octene can be produced in high yield.

When the chromium compound of one embodiment of the present invention is applied to the ethylene oligomerization reaction, the optimum activity temperature is 60° C. or higher, specifically 70° C. or higher, more specifically 80° C. or higher and 100° C. or lower, for example, 70° C., 80° C. , May be 90 ℃. Through this, it is possible to further increase the reaction heat control efficiency by air cooling or water cooling, excellent applicability to mass production processes, and a commercial advantage can be further improved.

The chromium compound of one embodiment of the present invention is applied to the ethylene oligomerization reaction, so that the amount of polyethylene produced can be significantly reduced compared to the conventional technology. In this case, while effectively preventing the balloon effect due to the accumulation of by-products applied to the mass production process, the commercial advantage can be further improved.

Specifically, R in Formula 1 may be an alkyl group having 1 to 30 carbon atoms or an aryl group having 6 to 30 carbon atoms. More specifically, R in Formula 1 may be an alkyl group represented by [CH ₃ (CH ₂ ) _d ] ₂ CH-* (d is 0 to 20). In this case, when the chromium compound of Formula 1 is applied to a catalyst system for an ethylene oligomerization reaction, the solubility in an aliphatic hydrocarbon solvent is further improved, and the polymerization reaction and the uniformity of the reaction product may be further improved.

In one embodiment, R in Formula 1 may be an isopropyl group ((CH ₃ ) ₂ CH-*). In this case, there is an advantage in that the chromium compound of Formula 1 can be prepared by using isopropylamine, which is inexpensive, as a raw material. In addition, there is an advantage of high 1-octene selectivity while implementing high activity when applied to a catalyst system for ethylene oligomerization reaction.

Z in Formula 1 is a silyl group bonded to the para position (-p-, para) of the phenyl moieties (-C ₆ H ₄ -) bonded to the phosphorus (P) atom in the chromium compound (*- Si(R ¹ ) _3-n (R ² ) _n ). The chromium compound in the form of Formula 1 consisting of a ligand that does not have a conventional silyl group substituent (for example, [{iPrN(P(C ₆ H ₅ ) ₂ ) ₂ }-CrCl ₂ ] ⁺ [AY ₄ ] ^- ) Silver ligands are easily converted to a compound in the 6-coordinated form in which two ligands are coordinated (ie, [{iPrN(P(C ₆ H ₅ ) ₂ ) ₂ } ₂ -CrCl ₂ ] ⁺ [AY ₄ ] ^- ). As described above, it is known that a compound of the conventional 6 coordination form in which two ligands are coordinated has no catalytic activity. On the other hand, the chromium compound according to Formula 1 of the present invention is a steric hindrance implemented by a silyl group (*-Si(R ¹ ) _3-n (R ² ) _n ) bonded to the para position (-p-, para) As an effect, a compound in which the compound of Formula 1 is coordinated with two ligands having no activity (ie, [{RN-(P(C ₆ H ₄ -pZ) ₂ ) ₂ } ₂ -CrX ₂ ] ⁺ [AY ₄ ] ^- In addition, in the chromium compound of Formula 1, the Hammett substituent constant (σ) of the silyl group is -0.07, which is the constant value of hydrogen (0). Similar to that, it is possible to maximize the effect of realizing high activity by inducing only steric hindrance effect while minimizing the electronic influence of the phosphine ligand.

Z in Formula 1 is a ligand coordinated in Formula 1 by introducing a silyl group (*-Si(R ¹ ) _3-n (R ² ) _n ) at the para position (-p-, para) in the chromium compound. (RN-(P(C ₆ H ₄ -pZ) ₂ ) ₂ ) There is an effect of limiting the rotation of the PN bond present in the ligand so that the ligand is strongly attached to chromium. In Chemical Formula 1, when Z is a ligand (ie, RN-(P(C ₆ H ₅ ) ₂ ) ₂ ) that is H instead of a silyl group as in the present invention, rotation of the PN bond is relatively easy. Accordingly, the ligand becomes the cause of decoordinating from chromium, which is a large amount of polyethylene (PE) at high temperature in the case of a catalyst made of a ligand (ie, RN-(P(C ₆ H ₅ ) ₂ ) ₂ ) where Z is H. ) It causes the generation of by-products. On the other hand, the chromium compound of Formula 1 of the present invention prepared from a ligand substituted with a silyl group (*-Si(R ¹ ) _3-n (R ² ) _n ) has a relatively stable ligand and minimizes the amount of PE produced even at high temperatures. High activity can be implemented.

Specifically, Z in Formula 1 may be an alkyl substituted silyl group having 4 to 50 carbon atoms. In the case of a silyl group (e.g., *-SiMe ₃ ) having less than 4 carbon atoms, for example, 3 alkyl-substituted silyl groups, the steric hindrance effect is insufficient, so that the inactive ligand does not prevent the conversion to a compound coordinated with 2 It is not possible to realize high activity.

More specifically, Z in Formula 1 is *-Si(R ¹ ) _3-n (R ² ) _n ; The R ¹ and R ² are each independently a branched or straight chain alkyl group having 1 to 25 carbon atoms, and n may be 0 to 3 (however, *-Si(R ¹ ) _3-n (R ² ) _n The sum of carbon numbers is 4 to 50). More specifically, Z in Formula 1 is *-Si(R ¹ ) ₃ or *-Si-[(CH ₂ ) _p CH ₃ ] _3-n [CH ₃ ] _n ; In this case, p is an integer of 4 to 20, and n may be an integer of 1 to 3. In this case, when the chromium compound of Formula 1 is applied to a catalyst system for an ethylene oligomerization reaction, the chromium compound can significantly improve the activity while reducing the amount of generation of the polymeric polyethylene compound as a by-product, which may be more advantageous for stable process operation.

For example, R ¹ and R ² are each independently consisting of methyl, ethyl, propyl, isopropyl, butyl, isobutyl, pentyl, isopentyl, neopentyl, hexyl, heptyl, octyl, nonyl, or a combination thereof. It may be an alkyl group or the like. In this case, the chromium compound of Formula 1 may further improve the effect of limiting rotation of a portion adjacent to the PN bond in the molecular structure.

In one embodiment, Z in Formula 1 may be a silyl group (*-Si(n-Butyl) ₃ ) in which a butyl group (n-butyl, nBu) is substituted. In this case, when the chromium compound of Formula 1 is applied to a catalyst system for an ethylene oligomerization reaction, the activity and selectivity can be further remarkably improved, and the amount of the polymer polyethylene compound as a by-product can be further reduced.

Specifically, X in Formula 1 may be halogen, more specifically fluorine (F), chlorine (Cl), bromine (Br), iodine (I), for example, chlorine (Cl). In this case, the mass productivity of the chromium compound represented by Formula 1 is further improved, and the supply of raw materials is easy.

Specifically, in Formula 1, Y is C ₆ F ₅ , 3,5-(CF ₃ ) ₂ C ₆ H ₃ , OC (CF _{3) 3} can be, for example, [AY _4] ^- is _{[B (C 6 F 5)} 4] -, [B ((3,5- (CF 3) 2 C 6 H 3) _4] ^-, or _{[Al (OC (CF 3)} 3) 4] -. this may be the case, and the mass productivity of the chromium compound improved more of the formula 1, which is an easy supply of the raw material.

In one embodiment, the chromium compounds of the formula (I) R is an isopropyl group, X is Cl, Z is _{* -Si (n-Butyl) 3} , [AY 4] - is _{[B (C 6 F 5)} 4] ^- it may be in. For example, such a chromium compound may be a compound represented by the following Formula 1-1. When the chromium compound of such a structural example is applied to a catalyst system for an ethylene oligomerization reaction, it is possible to further significantly improve the activity and selectivity while further reducing the amount of the polymer polyethylene compound as a by-product.

<Formula 1-1>

In another embodiment, in the chromium compound of Formula 1, R is an isopropyl group; X is Cl; Z is *-Si(iso-Propyl) ₃ , *-Si(Ethyl) ₃ , *-Si(iso-Propyl)(Ethyl) ₂ , *-Si(iso-Propyl)(Methyl) ₂ , or *-Si (1-Octyl)(Methyl) ₂ ; [AY _4] ^- is _{[B (C 6 F 5)} 4] - is; Can be. When the chromium compound of such a structural example is applied to a catalyst system for an ethylene oligomerization reaction, it is possible to further significantly improve the activity and selectivity while further reducing the amount of the polymer polyethylene compound as a by-product.

<Ethylene oligomerization catalyst system>

The catalyst system of another embodiment of the present invention includes a chromium compound represented by the above-described formula 1 as a main catalyst; And an organoaluminum compound represented by the following formula (2) as a cocatalyst. The catalyst system is very useful for the reaction of selectively converting ethylene to 1-hexene and 1-octene. In addition, this catalyst system eliminates the use of methylaluminoxane (MAO) or modified-methylaluminoxane (MMAO), while improving the activity and selectivity of the ethylene oligomerization reaction to remarkably excellent levels, resulting in 1-hexene and 1- Since octene can be produced in high yield, it is suitable for mass commercial processes, and extremely high activity and excellent economics can be achieved.

[Formula 2]

(R ³ ) ₃ Al

In Formula 2, R ³ is each independently an alkyl group having 1 to 20 carbon atoms.

Specifically, in Formula 2, R ³ may be a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a pentyl group, and more specifically an ethyl group or an isobutyl group.

A particularly excellent advantage of the catalyst system of the present invention is that high activity can be achieved while using a compound in which R ³ is ethyl or isobutyl in Formula 2 as a cocatalyst. The compound of Formula 2, wherein R ³ is ethyl or isobutyl, is triethyl aluminum or triisobutyl aluminum which is manufactured and used in large quantities at low prices in the industry. Therefore, the catalyst system of the present invention has high activity and 1-hexene and 1 while using the compound of Formula 2, which is inexpensive to manufacture while omitting the use of expensive modified-methylaluminoxane (MMAO), and is easy to supply raw materials. -High selectivity for octene can be implemented.

Specifically, the catalyst system may have a molar ratio (Cr:Al) of the chromium compound represented by Formula 1 and the organoaluminum compound represented by Formula 2 to be introduced in a range of 1:50 to 1:500. In the above range, the activity of the catalyst system can be further improved.

Specifically, the catalyst system may further include a halogen-substituted or unsubstituted hydrocarbon solvent. When including such a solvent, the catalyst system may exist in the form of a homogeneous solution in which the reactants are dissolved in the solvent.

More specifically, the halogen-substituted or unsubstituted hydrocarbon solvent may include toluene, xylene, chlorobenzene, dichlorobenzene, dichloromethane, methylcyclohexene, cyclohexene, hexane, and the like. In the above-exemplified solvent, the catalyst system of the present invention is easily formed and has more advantageous properties for separating the solvent from the 1-hexene and 1-octene products after the oligomerization reaction.

<Ethylene oligomer production method>

Another embodiment of the present invention relates to a method for producing an ethylene oligomer comprising the step of selectively preparing 1-hexene and 1-octene by contacting the above-described catalyst system with an ethylene monomer.

The catalyst system of the present invention described above may exist in the form of not only a homogeneous solution, but also supported on the carrier, in the form of insoluble particles of the carrier, etc., the method for preparing the ethylene oligomer (ethylene oligomerization reaction) is a liquid or slurry reaction. I can.

In addition, in the method for producing the ethylene oligomer, the reaction conditions may be variously modified depending on the state of the catalyst composition used (homogeneous or heterogeneous (supported)) and polymerization method (solution polymerization, slurry polymerization). The degree of modification thereof can be easily performed by a person skilled in the art.

Specifically, when the ethylene oligomerization reaction (polymerization) is carried out in a liquid phase or a slurry phase, a halogen-substituted or unsubstituted hydrocarbon solvent may be used as a medium.

More specifically, as the hydrocarbon solvent, an aliphatic hydrocarbon solvent having 4 to 20 carbon atoms, an aromatic hydrocarbon solvent having 6 to 20 carbon atoms, and a mixture thereof may be used. For example, examples of the halogen-substituted or unsubstituted hydrocarbon solvent include toluene, xylene, chlorobenzene, dichlorobenzene, dichloromethane, methylcyclohexene, cyclohexene, and hessein. When the above-described solvent is used, polymerization activity is high and it is easy to separate the products 1-hexene and 1-octene from the solvent after the oligomerization reaction.

In the method for producing the ethylene oligomer, the amount of the catalyst system is not particularly limited, but since the catalyst system described above of the present invention can achieve high activity, excellent yield can be realized even when the reaction is carried out by adding a small amount. .

In one embodiment, when the oligomerization reaction is carried out by solution polymerization, the molar concentration (based on chromium) of the catalyst system is 0.001 mmol/L to 0.02 mmol/L, for example, 0.05 mmol/L to 0.015 mmol. After the addition so as to be /L, by continuously adding the ethylene monomer and reacting for 10 minutes to 1 hour, 1-hexene and 1-octene can be produced. Ethylene may be continuously added at a pressure of 15 bar to 80 bar, specifically 40 bar to 60 bar, for example, 45 bar.

In addition, the reaction temperature during the ethylene oligomerization reaction may be from room temperature (20°C) to 110°C, for example, from 60°C to 90°C.

In addition, during the ethylene oligomerization reaction, the optimum activity temperature may be 60°C or more, specifically 70°C or more and 100°C or less, for example, 80°C to 90°C. Through this, it is possible to further increase the reaction heat control efficiency by air cooling or water cooling, excellent applicability to mass production processes, and a commercial advantage can be further improved.

In addition, the oligomerization reaction may be carried out in a batch, semi-continuous or continuous manner.

<Method for producing a chromium compound of Formula 1>

Another embodiment of the present invention relates to a method of preparing a chromium compound represented by Formula 1 above.

In one example, the method for preparing a chromium compound represented by Formula 1 of the present invention includes an ionic compound represented by the following Formula A; And reacting by adding a chromium precursor compound to the following formula (B), and then adding a bisphosphine ligand compound represented by the following formula (C) to react.

[Formula A]

[R ⁴ -N(H)(R ⁵ ) ₂ ] ⁺ [AY] ^-

In Formula A, R ⁴ is a substituted or unsubstituted aryl group having 6 to 60 carbon atoms; Each R ⁵ is independently a substituted or unsubstituted alkyl group having 1 to 60 carbon atoms; A is boron or aluminum; Y is aryl substituted with fluorine having 6 to 20 carbon atoms, aryloxy substituted with fluorine having 6 to 20 carbon atoms, or alkoxy substituted with fluorine having 1 to 20 carbon atoms. Detailed contents of A and Y are as described above.

[Formula B]

Cr(X ² ) ₃ (X ³ ) _m

In Formula B, X ² is each independently a halogen group, an acetylacetonate group, and a carboxylate group, X ³ is an ether-containing functional group having 2 to 20 carbon atoms or acetonitrile, and m is 0 or 3. . Detailed contents of X are as described above.

[Formula C]

RN-{P(-C ₆ H ₄ -pZ) ₂ } ₂

In Formula C, R is a substituted or unsubstituted alkyl group having 1 to 60 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 60 carbon atoms, and Z is *-Si(R ¹ ) _3-n (R ² ) _n , wherein R ¹ and R ² are each independently an alkyl group having 1 to 25 carbon atoms, and n is 0 to 3 (however, *-Si(R ¹ ) _3-n (R ² ) the sum of carbon atoms of _n is 4 to 50). Details of the R and Z are as described above.

Through this, the present invention can provide a chromium compound having remarkably excellent reaction activity and excellent selectivity for 1-hexene and 1-octene when applied to an ethylene oligomerization reaction.

The reaction of the ionic compound represented by Formula A with the chromium precursor compound represented by Formula B includes, for example, the ionic compound represented by Formula A; and the chromium precursor compound represented by Formula B; May be dispersed or dissolved in a solvent, and reacted by mixing them. At this time, the reaction temperature may be room temperature (20 ℃) to 100 ℃, specifically, 20 ℃ to 50 ℃, more specifically 20 ℃, the reaction time is 1 hour to 24 hours, specifically 1 hour to 12 hours, more Specifically, it may be 12 hours, but is not limited thereto.

Subsequently, in which the bisphosphine ligand compound represented by Formula C is added and reacted, for example, a bisphosphine ligand compound represented by Formula C dispersed or dissolved in a solvent is an ionic compound represented by Formula A; And It may be added to the reactant of the chromium precursor compound represented by Formula B and reacted. At this time, the reaction temperature may be room temperature (20 ℃) to 100 ℃, specifically, 20 ℃ to 50 ℃, more specifically 20 ℃, the reaction time is 10 minutes to 5 hours, specifically 10 minutes to 3 hours, more Specifically, it may be 2 hours, but is not limited thereto.

The solvent is not particularly limited as long as it has excellent dispersibility or solubility without inhibiting the reaction between the components. Specifically, the solvent may be acetonitrile (CH ₃ CN), dichloromethane (CH ₂ Cl ₂ ), or the like.

In one embodiment, the reaction for preparing the chromium compound of Formula 1 may be represented by the following Scheme 1.

[Scheme 1]

In the scheme 1 to a compound of formula _{A [PhN (H) Me 2} ] + [B (C 6 F 5) 4] - to use, using CrCl ₃ (THF) ₃ with a compound of formula B, formula C The reaction that occurs when iPrN[P(C ₆ H ₄ -p-Si(nBu) ₃ ) ₂ ] ₂ is used as a compound of is exemplarily shown. In the example of this reaction scheme 2, [PhN (H) Me 2] + [B (C 6 F 5) 4] - and CrCl ₃ (THF) ₃ is in a state dissolved in each of acetonitrile solvent (CH ₃ CN) They are mixed and the reaction proceeds while stirring for about 12 to 30 hours at room temperature. Then, after evaporation of the solvent the dichloro-methane (CH ₂ Cl ₂₎ was dissolved in a solvent and dichloro methane (CH ₂ Cl ₂₎ the state of iPrN [P (C ₆ dissolved in a solvent H ₄ -p-Si ( nBu) ₃ ) ₂ ] ₂ was added, and the reaction was carried out at room temperature for about 1 to 5 hours to [(iPrN[P(C ₆ H ₄ -p-Si(nBu) ₃ ) ₂ ] ₂ )-CrCl ₂ ] ⁺ [B(C ₆ F ₅ ) ₄ ] ^-A chromium compound having a structure can be prepared.

In this example of Scheme 1, the finally prepared [(iPrN[P(C ₆ H ₄ -p-Si(nBu) ₃ ) ₂ ] ₂ )-CrCl ₂ ] ⁺ [B(C ₆ F ₅ ) ₄ ] ^- may implement a more favorable effect on the separation, so insoluble in cyclohexane and purified ^- the chromium compound is methylcyclopentadienyl one it can be dissolved in a solvent such as hexane, a by-product of _{[PhN (H) Me 2]} + [Cl].

In another example, the method for preparing a chromium compound represented by Formula 1 of the present invention includes an ionic compound represented by the following Formula D; And a bisphosphine ligand compound represented by the following formula (C);

[Formula D]

[CrCl ₂ (NCCH ₃ ) ₄ ] ⁺ [AY] ^-

In Formula A, A is boron or aluminum; Y is aryl substituted with fluorine having 6 to 20 carbon atoms, aryloxy substituted with fluorine having 6 to 20 carbon atoms, or alkoxy substituted with fluorine having 1 to 20 carbon atoms. Detailed contents of A and Y are as described above.

[Formula C]

RN-{P(-C ₆ H ₄ -pZ) ₂ } ₂

In Formula C, R is a substituted or unsubstituted alkyl group having 1 to 60 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 60 carbon atoms, and Z is *-Si(R ¹ ) _3-n (R ² ) _n , wherein R ¹ and R ² are each independently an alkyl group having 1 to 25 carbon atoms, and n is 0 to 3 (however, *-Si(R ¹ ) _3-n (R ² ) the sum of carbon atoms of _n is 4 to 50). Details of the R and Z are as described above.

Through this, the present invention can provide a chromium compound having remarkably excellent reaction activity and excellent selectivity for 1-hexene and 1-octene when applied to an ethylene oligomerization reaction.

The ionic compound represented by Formula D; and the chromium precursor compound represented by Formula C may be reacted by, for example, dispersing or dissolving each component in a solvent, and mixing them to react. At this time, the reaction temperature may be room temperature (20 ℃) to 50 ℃, specifically, 20 ℃ to 30 ℃, more specifically 20 ℃, the reaction time is 10 minutes to 5 hours, specifically 30 minutes to 3 hours, more Specifically, it may be 2 hours to 3 hours, but is not limited thereto.

The solvent is not particularly limited as long as it has excellent dispersibility or solubility without inhibiting the reaction between the components. Specifically, the solvent may be dichloromethane (CH ₂ Cl ₂ ).

In another embodiment, the reaction for preparing the compound of Formula 1 may be represented by, for example, Scheme 2 below.

[Scheme 2]

Reaction Scheme 2, a compound of formula _{D [CrCl 2 (NCCH 3)} 4] + [B (C 6 F 5) 4] - and the use, iPrN to the compound of formula _{C [P (C 6 H 4} -p- The reaction that occurs when Si(nBu) ₃ ) ₂ ] ₂ is used is exemplarily shown. In the example of Scheme 2, each component is mixed in a state dissolved in a dichloromethane (CH ₂ Cl ₂ ) solvent, and the reaction proceeds while stirring at room temperature for 2 to 3 hours, [(iPrN[P( _{C 6 H 4 -p-Si (} nBu) 3) 2] 2) -CrCl 2] + [B (C 6 F 5) 4] - can be prepared chromium compound having the following structure.

Example

Hereinafter, the configuration and operation of the present invention will be described in more detail through preferred embodiments of the present invention. However, this is presented as a preferred example of the present invention and cannot be construed as limiting the present invention in any sense.

The components used in the following Preparation Examples and Comparative Examples were prepared as described in (1) to (3) below.

(1) [PhN(H)Me ₂ ] ⁺ [B(C ₆ F ₅ ) ₄ ] The ionic compound represented by ^- was purchased from TCI.

_{(2) [CrCl 2 (NCCH} 3) 4] + [B (C 6 F 5) 4] - a compound represented by was synthesized according to the method reported in the literature (Non-Patent Document 1: ACS Omega 2017, 2, 765).

(3) The compound represented by ClP[C ₆ H ₄ -p-Si(R ¹ ) _3-n (R ² ) _n ] ₂ was synthesized according to the method reported in the literature (Non-Patent Document 2: Angewandte Chemie International Edition 2016, 55, 12351).

[Scheme A]

Preparation Example 1:

A solution of iPrNH ₂ (0.174 g, 2.94 mmol) in CH ₂ Cl ₂ (10 mL) was dissolved in ClP[C ₆ H ₄ -p-Si(nBu) ₃ ] ₂ (3.64 g, 5.89 mmol) and Et ₃ N ( 2.98 g, 29.4 mmol) was added dropwise to a solution containing CH ₂ Cl ₂ (30 mL). After the reaction was allowed to stand overnight while stirring at room temperature, volatile components were removed through a vacuum line. After the residue was treated with hexane (40 mL), an insoluble by-product (Et ₃ NH) ⁺ Cl ^- was removed by filtration (Celite-aided filtration). The filtered liquid was passed through a short pad of silica gel pretreated with hexane/Et ₃ N (v/v, 50:1).

Through the above process, the resultant was obtained in the form of a colorless oil from which the solvent was removed (2.72 g, 70%). The isolated compound was subjected to NMR spectral analysis to achieve a degree of purity that did not require further purification. It was confirmed that the reaction product had a structure of the following formula C1.

[Chemical Formula C1]

iPrN[P(C ₆ H ₄ -p-Si(nBu) ₃ ) ₂ ] ₂

¹ H NMR (600 MHz, C ₆ D ₆ ): δ 8.10-7.27 (br, 8H), 7.50 (d, J = 7.2 Hz, 8H), 3.86 (m, NCH, 1H), 1.42-1.33 (br, 48H), 1.24 (d, J = 7.2 Hz, NCHCH ₃ , 6H), 0.92 (t, J = 6.6 Hz, CH ₃ , 36H), 0.87-0.82 (br, SiCH ₂ , 24H) ppm. ¹³ C{ ¹ H} NMR (150 MHz, C ₆ D ₆ ): δ 12.58 (nBu), 14.05 (nBu), 14.37, 23.07, 24.51 (t, J _PC = 7.2 Hz), 26.54 (nBu), 27.22 ( nBu), 31.99, 132.4-133.0 (br), 134.2 (d, J _PC = 5.7 Hz), 138.83 ppm. ³¹ P (243 MHz, C ₆ D ₆ ): δ 42.17, 54.96 ppm. HRMS (FAB): m/z calcd (M ⁺ C ₇₅ H ₁₃₁ NP ₂ Si ₄ ) 1219.8834, found 1219.8829.

Preparation Example 2:

Except for using _{ClP [C 6 H 4 -p-} Si (nBu) 3] 2 instead of _{ClP [C 6 H 4 -p-} Si (iPr) 3] 2 (1.00 g, 1.88 mmol) , and as in Preparation Example 2 The compound was prepared in the same way.

Through the above process, a compound having an analytically high purity was obtained by recrystallization in toluene at -30°C (0.160 g, 19%). It was confirmed that the reaction product had a structure of the following formula C2.

[Formula C2]

iPrN[P(C ₆ H ₄ -p-Si(iPr) ₃ ) ₂ ] ₂

¹ H NMR (600 MHz, C ₆ D ₆ ): δ 8.12-7.26 (br, 8H), 7.45 (d, J = 6.6 Hz, 8H), 3.83 (m, NCH, 1H), 1.32 (m, SiCH, 12H), 1.23 (d, J = 6.6 Hz, NCHCH ₃ , 6H), 1.10 (t, J = 7.8 Hz, CH ₃ , 72H) ppm. ¹³ C{ ¹ H} NMR (150 MHz, C ₆ D ₆ ): δ 11.10, 18.83, 21.44, 24.41 (t, J _PC = 5.7 Hz), 132.1-132.9 (br), 135.33 (d, J _PC = 5.7 Hz) ), 135.49-135.65 (br) ppm. ³¹ P (243 MHz, C ₆ D ₆ ): δ 43.63, 54.34 ppm.

Preparation Example 3:

In the same manner as in Preparation Example 2, except that ClP[C ₆ H ₄ -p-SiEt ₃ ] ₂ (1.00 g, 2.23 mmol) was used instead of ClP[C ₆ H ₄ -p-Si(nBu) ₃ ] ₂ The compound was prepared.

Through the above process, the resultant was obtained in the form of a viscous colorless viscous oil (0.428 g, 50%). It was confirmed that the reaction product had a structure of the following formula C3.

[Chemical Formula C3]

iPrN[P(C ₆ H ₄ -p-SiEt ₃ ) ₂ ] ₂

¹ H NMR (600 MHz, C ₆ D ₆ ): 8.16-7.20 (br, 8H), 7.44 (d, J = 6.6 Hz, 8H), 3.87 (m, NCH, 1H), 1.32 (m, SiCH, 12H ), 1.27 (d, J = 6.0 Hz, NCHCH ₃ , 6H), 0.98 (t, J = 7.8 Hz, CH ₃ , 36H), 0.74 (q, J = 7.2 Hz, SiCH ₂ , 24H) ppm. ¹³ C{ ¹ H} NMR (150 MHz, C ₆ D ₆ ): δ 3.70, 7.72, 24.58 (t, J _PC = 5.7 Hz), 133.1-132.5 (br), 134.32, 137.97, 141.02-141.58 (br) ppm . ³¹ P (243 MHz, C ₆ D ₆ ): δ 43.01, 54.90 ppm.

Preparation Example 4:

ClP[C ₆ H ₄ -p-Si(nBu) ₃ ] ₂ Instead of ClP[C ₆ H ₄ -p-Si(iPr)Et ₂ ] (1.58 g, 3.30 mmol) was used, and Preparation Example 2 The compound was prepared in the same way.

Through the above process, a resultant product in the form of a white glassy solid was obtained (1.02 g, 68%). It was confirmed that the reaction product had a structure of the following formula C4.

[Chemical Formula C4]

iPrN[P(C ₆ H ₄ -p-Si(iPr)Et ₂ ] ₂

¹ H NMR (600 MHz, C ₆ D ₆ ): 8.05-7.24 (br, 8H), 7.44 (d, J = 7.2 Hz, 8H), 3.85 (m, NCH, 1H), 1.25 (d, J = 6.6 Hz, NCHCH ₃ , 6H), 1.06-0.95 (br, 52H), 0.80 (q, J = 7.2 Hz, SiCH ₂ , 24H) ppm. ¹³ C{ ¹ H} NMR (150 MHz, C ₆ D ₆ ): δ 2.28, 7.89, 12.12, 18.19, 24.53 (t, J _PC =5.7 Hz), 52.70 (t, J _PC =10.1 Hz), 132.22- 133.09 (br), 134.70 (d, J _PC = 5.7 Hz), 137.07 ppm. ³¹ P (243 MHz, C ₆ D ₆ ): δ 43.18, 54.62 ppm.

Preparation Example 5:

_{ClP [C 6 H 4 -p-} Si (nBu) 3] 2 instead of _{ClP [C 6 H 4 -p-} Si (iPr) Me 2], preparation 2 except for using ₂ (0.56 g, 1.3 mmol) A compound was prepared in the same manner as described above.

Through the above process, a resultant product in the form of a white glassy solid was obtained (0.25 g, 45%). It was confirmed that the reaction product had a structure of the following formula C5.

[Chemical Formula C5]

iPrN[P(C ₆ H ₄ -p-Si(iPr)Me ₂ ] ₂

¹ H NMR (600 MHz, C ₆ D ₆ ): 8.09-7.20 (br, 8H), 7.44 (d, J = 6.0 Hz, 8H), 3.90 (m, NCH, 1H), 1.29 (d, J = 6 Hz, NCHCH ₃ , 6H), 0.97 (d, J = 6.0 Hz, 24H), 0.89 (m, SiCH, 4H), 0.19 (d, J = 4.8 Hz, SiCH ₃ , 24H) ppm. ¹³ C{ ¹ H} NMR (150 MHz, C ₆ D ₆ ): δ -5.2, 14.09, 17.84, 24.64 (t, J _PC =5.7 Hz), 132.41-132.89 (br), 134.07 (d, J _PC = 5.9 Hz), 139.17 ppm. ³¹ P (243 MHz, C ₆ D ₆ ): δ 43.43, 54.23 ppm.

Preparation Example 6:

Preparation, except that ClP[C ₆ H ₄ -p-Si(1-octyl)Me ₂ ] ₂ (1.82 g, 3.24 mmol) was used instead of ClP[C ₆ H ₄ -p-Si(nBu) ₃ ] ₂ A compound was prepared in the same manner as in Example 2.

Through the above process, the resultant was obtained in the form of a viscous colorless viscous oil (1.22 g, 68%). It was confirmed that the reaction product had a structure of the following formula C6.

[Chemical Formula C6]

iPrN[P(C ₆ H ₄ -p-Si(1-octyl)Me ₂ ] ₂

¹ H NMR (600 MHz, C ₆ D ₆ ): 8.14-7.22 (br, 8H), 7.48 (d, J = 6.6 Hz, 8H), 3.92 (m, NCH, 1H), 1.41-1.19 (br, 48H) ), 1.31 (d, J = 6.6 Hz, NCHCH ₃ , 6H), 0.92 (t, J = 7.2 Hz, CH ₃ , 12H), 0.78-0.72 (br, SiCH ₂ , 8H), 0.25 (d, J = 1.8 Hz, SiCH ₃ , 24H) ppm. ¹³ C{ ¹ H} NMR (150 MHz, C ₆ D ₆ ): δ -2.82, 14.41, 16.07, 23.14, 24.38, 24.69, 29.8 (d, J _PC = 5.7 Hz), 32.39, 34.10, 132.8 (d,) J _PC = 21.45 Hz), 133.73 (d, J _PC = 5.7 Hz), 140.32 ppm. ³¹ P (243 MHz, C ₆ D ₆ ): δ 42.90, 54.96 ppm.

Manufacturing Example 7:

In the same manner as in Preparation Example 2, except that ClP[C ₆ H ₄ -p-SiMe ₃ ] ₂ (1.54 g, 4.23 mmol) was used instead of ClP[C ₆ H ₄ -p-Si(nBu) ₃ ] ₂ The compound was prepared.

Through the above process, the resultant was obtained in the form of a viscous colorless viscous oil (0.564 g, 37%). It was confirmed that the reaction product had a structure of the following formula C7.

[Chemical Formula C7]

iPrN[P(C ₆ H ₄ -p-SiMe ₃ ) ₂ ] ₂

¹ H NMR (600 MHz, C ₆ D ₆ ): 7.93-7.32 (br, 8H), 7.43 (d, J = 7.2 Hz, 8H), 3.94 (m, NCH, 1H), 1.33 (d, J = 6.6 Hz, NCHCH ₃ , 6H), 0.20 (s, J = 7.2 Hz, SiCH ₃ , 36H) ppm. ¹³ C{ ¹ H} NMR (150 MHz, C ₆ D ₆ ): δ -1.10, 23.15, 24.76 (t, J _PC =5.7 Hz), 26.66, 26.82, 33.02,35.71, 52.52 (t, J _PC =10.1 Hz), 132.80 (d, J _PC = 20.1 Hz), 133.50 (d, J _PC = 4.2 Hz), 140.98 ppm. ³¹ P (243 MHz, C ₆ D ₆ ): δ 43.40, 54.62 ppm.

Example 1

A chromium compound having the structure of Formula 1-1 was prepared by the following method.

[Formula 1-1]

[(iPrN[P(C ₆ H ₄ -p-Si(nBu) ₃ ) ₂ ] ₂ )-CrCl ₂ ] ⁺ [B(C ₆ F ₅ ) ₄ ] ^-

: [PhN(H)Me ₂ ] ⁺ [B(C ₆ F ₅ ) ₄ ] ^- (0.15 g,. 0.23 mmol) solution dissolved in acetonitrile (2.9 mL) was added to acetonitrile (2.9 mL). mL) was added to a solution of CrCl ₃ (THF) ₃ (0.085 g, 0.23 mmol) dissolved in it. After the reaction was allowed to stand overnight while stirring at 25° C., volatile components were removed through a vacuum line. After dissolving the obtained green residue in CH ₂ Cl ₂ (2.0 mL), iPrN [P(C ₆ H ₄ -p-Si(nBu)) prepared in Preparation Example 2 was dissolved in CH ₂ Cl ₂ (4.6 mL). _{A solution in which 3} ) ₂ ] ₂ (0.28 g, 0.23 mmol) was dissolved was added dropwise. Thereafter, the color of the reaction solution immediately changed from green to bluish-green. Subsequently, after stirring at 25° C. for 2 hours, the solvent was removed through a vacuum line. After the residue was dissolved in methylcyclohexane, the insoluble portion was removed by filtration (Celite-aided filtration). A reaction product in the form of a viscous bluish-green viscous oil from which the solvent was removed was obtained (0.46 g, 99% based on the formula of [(iPrN[P(C ₆ H ₄ -p-Si(nBu))) ₃ ) ₂ ] ₂ )-CrCl ₂ ] ⁺ [B(C ₆ F ₅ ) ₄ ] ^- ).

Using CH ₂ Cl ₂ , the insoluble part (white solid mixed with a small amount of green solid, separated solid) was vertically from the top of Celite.

After removing the solvent of the residue, ¹ H NMR spectrum analysis was performed to confirm a signal corresponding to N,N-dimethylaniline unit. The weight (41 mg) of the separated solid content roughly coincided with the expected generation amount (36 mg) of the by-product [PhN(H)Me ₂ ] ⁺ Cl ⁻ . The isolated solid was dissolved in CH ₃ CN (1.0 mL), was treated with a solution obtained by dissolving the _{AgNO 3 (78 mg, 0.46 mmol} ) in CH ₃ CN (1.0 mL). A white solid precipitate (38 mg) was produced, which roughly matched the theoretical expected weight (33 mg) of AgCl.

The ³¹ P NMR spectrum, ¹ H NMR spectrum, ¹⁹ F NMR spectrum, and EPR spectrum analysis results of the chromium compound prepared in Example 1 are shown in FIG. 2.

Example 2

A chromium compound having the structure of Formula 1-1 was prepared by the following method.

[Formula 1-1]

[(iPrN[P(C ₆ H ₄ -p-Si(nBu) ₃ ) ₂ ] ₂ )-CrCl ₂ ] ⁺ [B(C ₆ F ₅ ) ₄ ] ^-

: A solution of iPrN[P(C ₆ H ₄ -p-Si(nBu) ₃ ) ₂ ] ₂ (0.10 g, 0.082 mmol) prepared in Preparation Example 2 in CH ₂ Cl ₂ (1.8 mL) was dissolved in CH ₂ [CrCl ₂ (NCCH ₃ ) ₄ ] ⁺ [B(C ₆ F ₅ ) ₄ ] ^- (0.079 g, 0.082 mmol) was dissolved in Cl ₂ (0.5 mL) and added dropwise to the prepared solution.

After the reaction was stirred at room temperature for 2.5 hours, the solvent was removed using a vacuum line to obtain a result in the form of a viscous light green oil (0.16 mg, 99% based on the formula of [ (iPrN[P(C ₆ H ₄ -p-Si(nBu) ₃ ) ₂ ] ₂ )-CrCl ₂ ] ⁺ [B(C ₆ F ₅ ) ₄ ] ^- ).

Example 3

A chromium compound having the structure of Formula 1-2 was prepared in the same manner as in Example 2, except that the bisphosphine ligand prepared in Preparation Example 2 was used instead of Preparation Example 1. A dark green solid reaction (0.086 g, 98%) was obtained.

[Formula 1-2]

[(iPrN[P(C ₆ H ₄ -p-Si(iPr) ₃ ) ₂ ] ₂ )-CrCl ₂ ] ⁺ [B(C ₆ F ₅ ) ₄ ] ^-

Example 4

A chromium compound having the structure of Formula 1-3 was prepared in the same manner as in Example 2, except that the bisphosphine ligand prepared in Preparation Example 3 was used instead of Preparation Example 1. A dark green solid reaction (0.052 g, 98%) was obtained.

[Formula 1-3]

[(iPrN[P(C ₆ H ₄ -p-SiEt ₃ ) ₂ ] ₂ )-CrCl ₂ ] ⁺ [B(C ₆ F ₅ ) ₄ ] ^-

Example 5

A chromium compound having the structure of Formula 1-4 was prepared in the same manner as in Example 2, except that the bisphosphine ligand prepared in Preparation Example 4 was used instead of Preparation Example 1. A dark green solid reaction (0.092 g, 99%) was obtained.

[Formula 1-4]

[(iPrN[P(C ₆ H ₄ -p-Si(iPr)Et ₂ ] ₂ )-CrCl ₂ ] ⁺ [B(C ₆ F ₅ ) ₄ ] ^-

In addition, the structure analyzed by X-ray crystallography of the chromium compound prepared in Example 5 is shown in FIG. 1.

Example 6

A chromium compound having the structure of Formula 1-5 was prepared in the same manner as in Example 2, except that the bisphosphine ligand prepared in Preparation Example 5 was used instead of Preparation Example 1. A dark green solid reaction (0.096 g, 98%) was obtained.

[Formula 1-5]

[(iPrN[P(C ₆ H ₄ -p-Si(iPr)Me ₂ ] ₂ )-CrCl ₂ ] ⁺ [B(C ₆ F ₅ ) ₄ ] ^-

Example 7

A chromium compound having the structure of Formula 1-6 was prepared in the same manner as in Example 2, except that the bisphosphine ligand prepared in Preparation Example 6 was used instead of Preparation Example 1. A reactant (0.084 g, 98%) in the form of a viscous green oil was obtained.

[Formula 1-6]

[(iPrN[P(C ₆ H ₄ -p-Si(1-octyl)Me ₂ ] ₂ )-CrCl ₂ ] ⁺ [B(C ₆ F ₅ ) ₄ ] ^-

Comparative Example 1

A chromium compound having the structure of Formula 1-7 was prepared in the same manner as in Example 2, except that the bisphosphine ligand having 3 carbon atoms of Z prepared in Preparation Example 7 was used instead of Preparation Example 1. A dark green solid reaction (0.103 g, 97%) was obtained.

[Formula 1-7]

[(iPrN[P(C ₆ H ₄ -p-SiMe ₃ ) ₂ ] ₂ )-CrCl ₂ ] ⁺ [B(C ₆ F ₅ ) ₄ ] ^-

Comparative Example 2

By the methods reported in the literature _{iPrN [P (C 6 H 5} ) 2] 2 and _{[CrCl 2 (NCCH 3) 4} ] + [B (C 6 F 5) 4] - with the structure of Formula 1-8 A chromium compound of was prepared (Non-Patent Document 1: ACS Omega, 2017, 2, 765).

[Formula 1-8]

[(iPrN[P(C ₆ H ₅ ) ₂ ] ₂ )-CrCl ₂ ] ⁺ [B(C ₆ F ₅ ) ₄ ] ^-

Comparative Example 3

[CH ₃ (CH ₂ ) ₁₆ ] ₂ CHN[P(C ₆ H ₅ ) ₂ ] ₂ and [CrCl ₂ (NCCH ₃ ) ₄ ] ⁺ [B(C ₆ F ₅ ) ₄ ] by the method reported in the literature ^were prepared using the chromium compounds of structure of formula 1-9 (non-Patent Document 1: ACS Omega, 2017, 2 , 765).

[Formula 1-9]

{[CH ₃ (CH ₂ ) ₁₆ ] ₂ CHN[P(C ₆ H ₅ ) ₂ ] ₂ )-CrCl ₂ } ⁺ [B(C ₆ F ₅ ) ₄ ] ^-

Example 8: Ethylene oligomerization reaction

Methylcyclohexane (19 mL) and a chromium compound of Formula 1-1 prepared in Example 1 (0.41 mg, 0.20 μmol) were added to a dried reactor (75 mL bomb reactor) in a glove box. After the reactor was assembled, it was taken out of the glove box. After dissolving iBu ₃ Al (15.9 mg, 0.080 mmol) in methylcyclohexane (1 mL), it was injected into the reactor using a syringe at room temperature, and then ethylene gas was immediately introduced at a pressure of 45 bar. The temperature of the reactor was spontaneously increased from 20° C. to 90° C. by an exothermic reaction for 3.5 minutes. When the temperature reached 90° C., the fan was operated to remove the heat. The temperature was further increased for 5 minutes to reach 96°C, and then gradually lowered to 88°C for 25 minutes. After the ethylene oligomerization reaction proceeded for 25 minutes, the reactor was cooled by putting it in a water bath containing ice, and ethylene gas was discharged to terminate the reaction.

For gas chromatography analysis (GC analysis) of the resulting material, Nonane (0.700 g) was added to the final reactant according to an internal standard. Oligomers (1-octene (1-C8), 1-hexene (1-C6), methylcyclopentane + methylenecyclopentane (cy-C6), and higher oligomers above C10 (> C10) generated through gas chromatography analysis (GC analysis) After measuring the content of ), it was converted to a percentage based on the weight. The produced solid polyethylene (PEs) was separated through filtration at 80°C, and the weight was measured, and the weight of PE through the formula of [Production PE weight (g) / ethylene weight (g) used in reaction] % Was calculated.

Example 9: Ethylene oligomerization reaction

Instead of the chromium compound of Formula 1-1 prepared in Example 1, the chromium compound of Formula 1-1 prepared in Example 2 was used, and the reaction temperature was adjusted to 24°C to 98°C, and the reaction time was adjusted to 30 minutes. Except, the ethylene oligomerization reaction was carried out in the same manner as in Example 8.

Example 10: Ethylene oligomerization reaction

The ethylene oligomerization reaction was carried out in the same manner as in Example 9, except that the reaction temperature was adjusted to 28°C to 75°C and the reaction time was adjusted to 30 minutes.

Example 11: Ethylene oligomerization reaction

The ethylene oligomerization reaction was carried out in the same manner as in Example 9, except that the reaction temperature was adjusted to 26°C to 60°C and the reaction time was adjusted to 30 minutes.

Example 12: Ethylene oligomerization reaction

Ethylene oligomer in the same manner as in Example 8, except that the chromium compound of Formula 1-2 was used instead of the chromium compound of Formula 1-1, and the reaction temperature was adjusted to 25°C to 84°C, and the reaction time was adjusted to 30 minutes. The reaction proceeded.

Example 13: Ethylene oligomerization reaction

Ethylene oligomer in the same manner as in Example 8, except that the chromium compound of Formula 1-3 was used instead of the chromium compound of Formula 1-1, and the reaction temperature was adjusted to 25°C to 85°C and the reaction time was adjusted to 30 minutes. The reaction proceeded.

Example 14: Ethylene oligomerization reaction

Ethylene oligomer in the same manner as in Example 8, except that the chromium compound of Formula 1-4 was used instead of the chromium compound of Formula 1-1, and the reaction temperature was adjusted to 22°C to 89°C and the reaction time was adjusted to 30 minutes. The reaction proceeded.

Example 15: Ethylene oligomerization reaction

Ethylene oligomer in the same manner as in Example 8, except that the chromium compound of Formula 1-5 was used instead of the chromium compound of Formula 1-1, and the reaction temperature was adjusted to 25°C to 79°C, and the reaction time was adjusted to 30 minutes. The reaction proceeded.

Example 16: Ethylene oligomerization reaction

Ethylene oligomer in the same manner as in Example 8, except that the chromium compound of Formula 1-6 was used instead of the chromium compound of Formula 1-1, and the reaction temperature was adjusted to 24°C to 82°C, and the reaction time was adjusted to 30 minutes. The reaction proceeded.

Comparative Example 4: Ethylene oligomerization reaction

Ethylene oligomer in the same manner as in Example 8, except that the chromium compound of Formula 1-7 was used instead of the chromium compound of Formula 1-1, and the reaction temperature was adjusted to 25°C to 35°C and the reaction time was adjusted to 35 minutes. The reaction proceeded.

Comparative Example 5: Ethylene oligomerization reaction

The ethylene oligomerization reaction was carried out in the same manner as in Example 8, except that the chromium compound of Formula 1-8 was used instead of the chromium compound of Formula 1-1, and the reaction temperature was adjusted to 45°C and the reaction time was adjusted to 30 minutes. Proceeded.

Comparative Example 6: Ethylene oligomerization reaction

The ethylene oligomerization reaction was carried out in the same manner as in Example 8, except that the chromium compound of Formula 1-9 was used instead of the chromium compound of Formula 1-1, and the reaction temperature was adjusted to 45°C and the reaction time was adjusted to 30 minutes. Proceeded.

The activity of the olefin polymerization reaction of Examples 8 to 16 and Comparative Examples 4 to 6, and the composition of the prepared polymer are shown in Table 1 below.

Chromium compound temp (°C); time (min) activity (Kg/g-Cr/h) 1-C8
(wt%) 1-C6
(wt%) cy-C6 (wt%) > C10 (wt%) PE (wt%) Example 8 Formula 1-1 20-96; 25 4700 45.4 32.4 3.0 19.0 0.01 Example 9 Formula 1-1 24-98; 15 6310 45.1 34.5 3.0 17.2 0.03 Example 10 Formula 1-1 28~75;30 4420 52.8 25.7 3.6 17.8 0.03 Example 11 Formula 1-1 26~60;30 3640 67.0 15.9 3.4 13.4 0.03 Example 12 Formula 1-2 25-84; 30 3020 55.8 27.2 3.2 13.7 0.05 Example 13 Formula 1-3 25-85; 30 2760 58.1 25.6 3.3 12.7 0.18 Example 14 Formula 1-4 22-89; 30 3260 53.8 28.6 3.1 14.3 0.02 Example 15 Formula 1-5 25-79; 30 2430 63.0 21.8 3.8 11.15 0.01 Example 16 Formula 1-6 24-82; 30 2890 55.5 25.3 3.5 15.5 0.06 Comparative Example 4 Formula 1-7 25~35 0 - - - - - Comparative Example 5 Formula 1-8
(Z = H; R = iPr) 45; 30 26 68.0 10.5 4.5 14.9 1.3 Comparative Example 6 Formula 1-9
(Z = H; R = [CH ₃ (CH ₂ ) ₁₆ ] ₂ CH) 45; 30 84 70.3 14.3 4.7 9.4 1.0

As can be seen from the experimental results of Table 1, the formulas 1-1 to having a *-Si(R ¹ ) _3-n (R ² ) _n substituent having 4 to 50 carbon atoms at the para-position of the present invention When the chromium compound of Formula 1-6 was applied to a catalyst system for an ethylene oligomerization reaction, the activity was very remarkably excellent at 2400 to 6300 Kg/g-Cr/h or more.

On the other hand, a chromium compound of Formula 1-7 having a silyl group having 3 carbon atoms (Z = *-SiMe ₃ ) with insufficient steric hindrance and a silyl group having 0 carbon atoms (Z = H) Formula 1-8 and Formula 1- In the case of Comparative Examples 4 to 6 using the chromium compound of 9, it can be seen that the reaction activity is significantly lower (1/30 to 1/250 level) compared to Examples 8 to 16 of the present invention.

In particular, when the chromium compound of Formula 1-1 having a large sterically hindered *-Si(nBu) ₃ substituent according to the present invention is included, the maximum activity is very high at 6300 Kg/g-Cr/h, and polyethylene (PE) It can be seen that the amount of by-products is very low (0.01 wt%), and it operates as a catalyst even at a high temperature of about 90° C. and is suitable for commercial process input.

Simple modifications or changes of the present invention can be easily implemented by those of ordinary skill in the art, and all such modifications or changes can be considered to be included in the scope of the present invention.

Claims (10)

Chromium compound represented by the following formula (1):
[Formula 1]
[(RN-{P(C ₆ H ₄ -pZ) ₂ } ₂ )-CrX ₂ ] ⁺ [AY ₄ ] ^-
In Formula 1, Cr is coordinated to two Ps,
R is an alkyl group having 1 to 20 carbon atoms; Z is *-Si(R ¹ ) _3-n (R ² ) _n , wherein R ¹ and R ² are each independently an alkyl group having 1 to 25 carbon atoms, and n is 0 to 3 (however, *-Si( R ¹ ) _3-n (R ² ) the sum of carbon number of _n is 4 to 50); Each X is independently halogen; A is boron; Y is an aryl having 6 to 20 carbon atoms substituted with fluorine.
The method of claim 1,
Of Formula 1 [AY _4] ^- is _{[B (C 6 F 5)} 4] - a chromium compound.
The method of claim 1,
Z in Formula 1 is *-Si(R ¹ ) ₃ ;
Each of R ¹ is independently ethyl, isopropyl, or n-butyl.
The method of claim 1,
R in Formula 1 is an isopropyl group, a chromium compound.
The method of claim 1,
X in Formula 1 is a chromium compound of Cl.
A chromium compound represented by the following formula (1); And
Ethylene oligomerization catalyst system comprising an organoaluminum compound represented by the following Formula 2:
[Formula 1]
[(RN-{P(C ₆ H ₄ -pZ) ₂ } ₂ )-CrX ₂ ] ⁺ [AY ₄ ] ^-
In Formula 1, Cr is coordinated to two Ps,
R is an alkyl group having 1 to 20 carbon atoms; Z is *-Si(R ¹ ) _3-n (R ² ) _n , wherein R ¹ and R ² are each independently an alkyl group having 1 to 25 carbon atoms, and n is 0 to 3 (however, *-Si( R ¹ ) _3-n (R ² ) the sum of carbon number of _n is 4 to 50); Each X is independently halogen; A is boron; Y is an aryl having 6 to 20 carbon atoms substituted with fluorine;
[Formula 2]
(R ³ ) ₃ Al
In Formula 2, R ³ is an alkyl group having 1 to 20 carbon atoms.
The method of claim 6,
R ³ of Formula 2 is an isobutyl group or an ethyl group, an ethylene oligomerization catalyst system.
The method of claim 6,
The catalyst system is an ethylene oligomerization catalyst system in which the molar ratio of the chromium compound represented by Formula 1 and the aluminum compound represented by Formula 2 to be introduced is 1:50 to 1:500.
The method of claim 6,
R in Formula 1 is an isopropyl group; X is Cl; Z is *-Si(R ¹ ) ₃ and R ¹ is each independently ethyl, isopropyl, or n-butyl; [AY _4] ^- is _{[B (C 6 F 5)} 4] -; Phosphorus ethylene oligomerization catalyst system.
A method for producing an ethylene oligomer comprising the step of selectively preparing 1-hexene and 1-octene by contacting the catalyst system according to any one of claims 6 to 9 with an ethylene monomer.

Images