A binuclear catalyst based on anthracene β-keto monoimine, its preparation method and application

Abstract

This invention relates to a binuclear catalyst based on anthracene β-ketone monoimine, its preparation method, and its application. The binuclear catalyst has the following general structural formula (1): Formula (1); wherein R1, R2, R3, and R4 are each independently selected from H, halogens, C1-C12 straight-chain or branched alkyl groups, C3-C8 cycloalkyl groups, C6-C15 substituted or unsubstituted aryl groups, or C6-C15 aralkyl groups; R5 is selected from C6-C15 substituted or unsubstituted aryl groups; R6 is selected from halogens, alkyl groups, aralkyl groups, amino groups, and alkoxy groups; M is selected from Ti, Zr, and Hf metals. The catalytic activity of this binuclear catalyst can reach 19-24 kg / (mmol·h) at a polymerization temperature of 110 °C.

Description

Technical Field

[0001] This invention relates to the field of non-ceramic transition metal polyolefin catalyst technology, specifically to a binuclear catalyst based on anthracene β-keto monoimine, its preparation method, and its application. Background Technology

[0002] Polyolefins, as bulk chemical products, are widely used in agriculture, packaging, electronics, electrical appliances, automobiles, machinery, and daily necessities, making them the most important synthetic polymer materials in industrial production and daily life. Catalyst technology, as the lifeblood of the polyolefin industry, determines the development of the polyolefin field. From the heterogeneous Ziegler-Natta catalysts that emerged in the 1950s to the metallocene olefin polymerization catalysts that arose in the 1980s, the polyolefin industry has successfully achieved control over polymerization behavior and polymer structure.

[0003] Non-metallocene transition metal polyolefin catalysts exhibit high olefin polymerization activity and relatively simple synthesis, possessing enormous development potential. Significant progress has been made in the research of non-metallocene transition metal polyolefin catalysts over the past 30 years. In the last two decades, non-metallocene olefin polymerization catalysts, as a new generation of highly promising α-olefin homopolymerization or copolymerization catalysts, have attracted widespread attention from industry and academia. They are defined as organometallic complexes that do not contain cyclopentadiene or its derivative groups, commonly using oxygen, nitrogen, phosphorus, or sulfur as coordinating atoms, and with a transition metal element as the metal center. This new generation of catalysts not only retains the advantages of metallocene catalysts, such as high catalytic activity, ease of introducing various comonomers, and controllable polymer structure, but also possesses advantages such as structural diversity, good stability, and low production cost.

[0004] However, existing non-metallic transition metal polyolefin catalysts often suffer from low catalytic activity at high polymerization temperatures. Summary of the Invention

[0005] This invention provides a binuclear catalyst based on anthracene β-keto monoimine, which is suitable for higher catalytic temperatures and has high catalytic activity.

[0006] The present invention also provides a method for preparing the above-mentioned anthracene β-keto monoimine-based binuclear catalyst, which has a simple and efficient synthetic route and can obtain the product in high yield.

[0007] The present invention also provides an olefin polymerization catalyst that maintains high catalytic activity at higher temperatures.

[0008] The present invention also provides a method for olefin polymerization, which can efficiently prepare polymer products with high weight-average molecular weight.

[0009] The present invention achieves the above objectives through the following technical solutions:

[0010] A binuclear catalyst based on anthracene β-keto monoimine, the binuclear catalyst having the general structural formula shown in formula (1): ;

[0011] R1, R2, R3, and R4 are each independently selected from H, halogens, C1-C12 straight-chain or branched alkyl groups, C3-C8 cycloalkyl groups, C6-C15 substituted or unsubstituted aryl groups, or C6-C15 aralkyl groups; R5 is selected from C6-C15 substituted or unsubstituted aryl groups; R6 is selected from halogens, alkyl groups, aralkyl groups, amino groups, and alkoxy groups; M is selected from Ti, Zr, and Hf metals.

[0012] In the binuclear catalyst described above, in the general structural formula (1) of the binuclear catalyst, R1, R2, R3, and R4 are each independently selected from H, halogens, C1-C8 straight-chain or branched alkyl groups, C5-C8 cycloalkyl groups, C6-C10 substituted or unsubstituted aryl groups, or C6-C10 aralkyl groups; R5 is selected from C6-C10 substituted or unsubstituted aryl groups; R6 is selected from halogens, alkyl groups, aralkyl groups, amino groups, and alkoxy groups; and M is selected from Ti, Zr, and Hf metals.

[0013] In the binary catalyst described above, in the general structural formula (1), R1, R2, R3, and R4 are each independently selected from methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, n-pentyl, isopentyl, n-hexyl, isohexyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, phenyl, p-tolyl, o-tolyl, or benzyl; R5 is selected from substituted or unsubstituted aryl groups; R6 is selected from halogen, alkyl, aralkyl, amine, and alkoxy groups; and M is selected from Ti, Zr, and Hf metals.

[0014] This invention also provides a method for preparing the above-mentioned anthracene β-keto monoimine-based binuclear catalyst, comprising the following steps:

[0015] The anthraquinone monoimide complex shown in formula (2) is reacted with a metal compound containing titanium, zirconium, or hafnium in an organic solvent. After the reaction is complete, the mixture is washed, filtered, and dried to obtain the final product.

[0016] The reaction equations for the coordination compounds and metal compounds are as follows:

[0017] ;

[0018] Among them, R1, R2, R3, R4, and R5 are defined as described above; MX4, where M is metal Ti, Zr, or Hf, and X is a halogen; M(R6)4, where M is metal Ti, Zr, or Hf, and R is dimethylamino or benzyl.

[0019] In the preparation method described above, the molar ratio of the anthracene β-keto monoimine complex to the metal compound is 1:1 to 1:3; preferably, the molar ratio is 1:1 to 1:1.5; and / or

[0020] The reaction temperature of anthracene β-keto monoimine complexes with metal compounds is not higher than 0°C; preferably, the reaction temperature is -40 to 0°C; and / or

[0021] The reaction time of the anthracene β-keto monoimine complex with the metal compound is 18-24 h; preferably, the reaction time is 20-24 h.

[0022] In the preparation method described above, the organic solvent is toluene or dichloromethane.

[0023] The preparation method described above, the preparation of the compound represented by formula (2) includes the following steps:

[0024] 9,10-Anthracene dicarboxaldehyde was reacted with 2,2,2-trimethoxy-4,5-dimethyl-1,3,2-dioxocyclophosphene in a solvent at room temperature to give anthracene diacetylacetone.

[0025] The mixture containing anthracene diacetylacetone, aniline, p-toluenesulfonic acid, and mesitylene was refluxed and the water was removed. After the reaction was completed, the compound shown in formula (2) was obtained by separation.

[0026] The preparation method described above, the preparation of the compound represented by formula (2) includes the following steps:

[0027] 9,10-Anthracene dicarboxaldehyde was dissolved in dichloromethane, and 2,2,2-trimethoxy-4,5-dimethyl-1,3,2-dioxocyclophosphene was added dropwise at room temperature. After the addition was complete, the mixture was stirred overnight. The reaction progress was detected by thin-layer chromatography. After the reaction was complete, the solvent was removed under reduced pressure, anhydrous ethanol was added, and the mixture was refluxed at 70-90°C to separate anthracene diacetylacetone.

[0028] Anthracene diacetylacetone, aniline, and p-toluenesulfonic acid were mixed, and thiamethoxam was added and refluxed to remove water. After the reaction was completed, the mixture was concentrated by rotary evaporation and separated by column chromatography to obtain a light yellow solid product, namely the compound shown in formula (2).

[0029] In the preparation method described above, in the preparation steps of the compound shown in formula (2), the molar ratio of 9,10-anthracene dicarboxaldehyde to 2,2,2-trimethoxy-4,5-dimethyl-1,3,2-dioxocyclophosphene is 1:(5-12), and the molar ratio of anthracene diacetylacetone to aniline is 1:(1-20).

[0030] The present invention also provides the application of the above-mentioned anthracene-β-ketomonimine-based binuclear catalyst in catalytic olefin polymerization; preferably, the anthracene-β-ketomonimine-based binuclear catalyst together with the co-catalyst organoaluminum forms a catalytic system for catalytic olefin polymerization.

[0031] The anthracene-β-keto monoimine-based binuclear catalyst provided by this invention provides better protection for the active center of the catalytic system by introducing a sterically hindered aniline onto the highly rigid anthracene skeleton, thereby enhancing the stability and activity of catalytic olefin polymerization. The catalytic activity of this binuclear catalyst can reach 19-24 Kg / (mmol·h) at a polymerization temperature of 110°C. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions in the embodiments of this invention will be clearly and completely described below in conjunction with the embodiments of this invention. Obviously, the described embodiments are only some embodiments of this invention, not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0033] Non-metallocene olefin polymerization catalysts, as a new generation of highly promising α-olefin homopolymerization or copolymerization catalysts, often suffer from low catalytic activity at high polymerization temperatures. This is especially true for liquid-phase polymerization reactions, where most raw materials need to remain in the liquid phase at high temperatures. Therefore, high requirements are placed on the high-temperature stability and catalytic activity of the catalysts.

[0034] Based on this, the first aspect of the present invention provides a novel binuclear catalyst based on anthracene β-keto monoimine, the binuclear catalyst having the general structural formula shown in formula (1) below: ;

[0035] R1, R2, R3, and R4 are each independently selected from H, halogens, C1-C12 straight-chain or branched alkyl groups, C3-C8 cycloalkyl groups, C6-C15 substituted or unsubstituted aryl groups, or C6-C15 aralkyl groups; R5 is selected from C6-C15 substituted or unsubstituted aryl groups; R6 is selected from halogens, alkyl groups, aralkyl groups, amino groups, and alkoxy groups; M is selected from Ti, Zr, and Hf metals.

[0036] This anthracene-β-keto monoimine-based binuclear catalyst enhances the stability and activity of catalytic olefin polymerization by introducing a sterically hindered aniline onto a highly rigid anthracene skeleton to protect the active center of the catalytic system. The binuclear catalyst achieves a catalytic activity of 19-24 Kg / (mmol·cat·h) at a polymerization temperature of 110 °C.

[0037] In detail, when the general formula (1) of the binuclear catalyst is composed of R1, R2, R3, and R4, each independently selected from H, halogen, C1-C8 straight-chain or branched alkyl, C5-C8 cycloalkyl, C6-C10 substituted or unsubstituted aryl, or C6-C10 aralkyl; R5 selected from C6-C10 substituted or unsubstituted aryl; R6 selected from halogen, alkyl, aralkyl, amino, and alkoxy groups; and M selected from Ti, Zr, and Hf metals, the polymerization performance is superior.

[0038] Furthermore, when the general formula (1) of the binuclear catalyst is composed of R1, R2, R3, and R4, each independently selected from methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, n-pentyl, isopentyl, n-hexyl, isohexyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, phenyl, p-tolyl, o-tolyl, or benzyl; R5 is selected from substituted or unsubstituted aryl groups; R6 is selected from halogen, alkyl, aralkyl, amine, and alkoxy groups; and M is selected from Ti, Zr, and Hf metals, the polymerization performance is the most superior.

[0039] A second aspect of the present invention provides a method for preparing the above-mentioned anthracene β-keto monoimine-based binuclear catalyst, comprising the following steps:

[0040] 9,10-Anthracene dicarboxaldehyde was reacted with 2,2,2-trimethoxy-4,5-dimethyl-1,3,2-dioxocyclophosphene to obtain anthracene diacetylacetone, and anthracene diacetylacetone was reacted with aniline to obtain the anthracene β-keto monoimine complex shown in formula (2).

[0041] The anthraquinone monoimide complex shown in formula (2) is reacted with a metal compound containing titanium, zirconium, or hafnium in an organic solvent. After the reaction is complete, the mixture is washed, filtered, and dried to obtain the final product.

[0042] The reaction equations for the complexes and metal compounds are as follows:

[0043] ;

[0044] Wherein, R1, R2, R3, R4, and R5 are defined as described in claim 1; MX4, where M is metal Ti, Zr, or Hf, and X is a halogen; M(R6)4, where M is metal Ti, Zr, or Hf, and R is dimethylamino or benzyl.

[0045] The reaction of the aforementioned complex with the metal compound follows a conventional method for preparing anthracene β-keto monoimine metal complexes from anthracene β-keto monoimine complexes with titanium, zirconium, or hafnium-containing metal compounds. The synthetic route is simple. Specifically, the anthracene β-keto monoimine complex is used as the substrate in the reaction with a titanium, zirconium, or hafnium-containing metal compound. The molar ratio of the anthracene β-keto monoimine complex to the metal compound is typically 1:1 to 1:3. A molar ratio between 1:1 and 1:1.5 results in a more complete reaction. The reaction temperature is usually no higher than 0°C, and more commonly, a temperature between -40°C and 0°C is used. The reaction time is typically 18-24 hours, commonly 20-24 hours, ensuring sufficient reaction time.

[0046] In this reaction system, toluene or dichloromethane (DCM) is usually used as the solvent to maintain an anhydrous reaction system. After the reaction is complete, the solid obtained is the corresponding product after routine washing, filtration and separation, and vacuum drying. The yield is generally between 45-65%.

[0047] In this invention, the compound shown in formula (2) can be prepared by the following steps: 9,10-anthracene dicarboxaldehyde is reacted in a solvent at room temperature with 2,2,2-trimethoxy-4,5-dimethyl-1,3,2-dioxocyclophosphene to obtain anthracene diacetylacetone; anthracene diacetylacetone is mixed with aniline and p-toluenesulfonic acid, and mesitylene is added and refluxed to remove water. After the reaction is completed, the compound shown in formula (2) is obtained by separation.

[0048] In some specific embodiments, the preparation of the compound shown in formula (2) includes the following steps: 9,10-anthracene dicarboxaldehyde is dissolved in dichloromethane, and 2,2,2-trimethoxy-4,5-dimethyl-1,3,2-dioxocyclophosphene is added dropwise at room temperature. After the addition is complete, the mixture is stirred overnight. The reaction progress is detected by thin-layer chromatography. After the reaction is complete, the solvent is removed under reduced pressure, anhydrous ethanol is added, and the mixture is refluxed to separate anthracene diacetylacetone. Anthracene diacetylacetone, aniline, and p-toluenesulfonic acid are mixed, and mesitylene is added and refluxed to separate water. After the reaction is complete, the mixture is concentrated by rotary evaporation and separated by column chromatography to obtain a light yellow solid product, which is the compound shown in formula (2).

[0049] In the preparation steps of the compound shown in formula (2), the molar ratio of 9,10-anthracene dicarboxaldehyde to 2,2,2-trimethoxy-4,5-dimethyl-1,3,2-dioxocyclophosphene is 1:(5-12), and the molar ratio of anthracene diacetylacetone to aniline is 1:(1-20).

[0050] In this invention, the precursor compound 9,10-anthracenedicarboxaldehyde is a known compound that can be purchased or synthesized using the following synthetic route:

[0051] ;

[0052] ;

[0053] .

[0054] A third aspect of the present invention provides an olefin polymerization catalyst, comprising a main catalyst and a co-catalyst, wherein the main catalyst is the aforementioned anthraquinone-based binuclear catalyst and the co-catalyst is an organoaluminum. This catalyst can efficiently catalyze olefin polymerization at higher temperatures.

[0055] A fourth aspect of the present invention provides an olefin polymerization method, comprising at least the step of catalyzing olefin polymerization using the above-described olefin polymerization catalyst, wherein the olefin polymerization is carried out at 110°C and the product has a high weight-average molecular weight.

[0056] Those skilled in the art will understand that this binuclear catalyst can form a catalytic system together with a co-catalyst (such as organoaluminum) when catalyzing olefin polymerization.

[0057] The present invention will be further described below through specific embodiments.

[0058] Example 1

[0059] This embodiment uses the preparation of anthracene β-keto monoimine complexes with R1, R2, R3, and R4 being H and R5 being 2,4,6-trimethyl as an example. The specific structural formula of the anthracene β-keto monoimine complex (anthrayl ligand) is as follows: .

[0060] 10.3 g (57.8 mmol) of anthracene was weighed and added to a 500 mL three-necked flask, along with 200 mL of chloroform as a solvent. The system was cooled to 0–10 °C using a cold trap alcohol bath and liquid nitrogen, and maintained at this temperature. 18.8 g (113.1 mmol) of liquid bromine was weighed and dissolved in 50 mL of chloroform. The bromine solution was slowly added dropwise to the three-necked flask using a constant-pressure dropping funnel, maintaining the temperature below 10 °C. The generated hydrogen bromide gas was passed through a saturated potassium hydroxide solution for tail gas absorption. After approximately 2 hours, the addition was complete, and the reaction was allowed to proceed overnight at room temperature. Thin-layer chromatography was used to monitor the reaction progress. After the reaction was complete, a large amount of yellow-green precipitate appeared in the system, and the solution turned reddish-brown. The precipitate was filtered out under reduced pressure. The mother liquor was concentrated under vacuum, and the product was crystallized. The products were combined, and a wet weight of 16 g was obtained. After vacuum drying, the product 9,10-dibromoanthracene was obtained, with a dry weight of 15.58 g, yielding a yield of 82%.

[0061]

[0062] Weigh 15.08 g (44.87 mmol) of 9,10-dibromoanthracene into a 1 L three-necked flask and add it to 400 mL of anhydrous diethyl ether. Purge the three-necked flask and the constant-pressure dropping funnel with nitrogen as a protective gas. Under nitrogen protection, use a syringe to draw 39.3 mL (98.22 mmol, 2.5 mol / L) of n-butyllithium solution and add it to the constant-pressure dropping funnel. Cool the 9,10-dibromoanthracene suspension to -10 °C and slowly add n-butyllithium dropwise, maintaining the temperature below -10 °C. After the addition of n-butyllithium, the suspension turns deep orange, and the solid gradually dissolves. After the addition is complete, stir the suspension at 0 °C for 30 minutes, and an orange solid precipitates. Then react at room temperature for one hour, using a liquid nitrogen-alcohol bath to lower the system temperature to -78 °C. 14.5 g (198.4 mmol) of N,N-dimethylformamide was weighed and added to a constant-pressure dropping funnel. N,N-dimethylformamide was slowly added dropwise. After the addition was complete, the temperature of the system was maintained at approximately -78°C, and the reaction was allowed to proceed for two hours. After the reaction was complete, water was added to quench the reaction, and most of the product precipitated. The crude product was obtained by filtration under reduced pressure. The product was deep orange in color. The mother liquor was extracted with dichloromethane, and the liquid was separated. The organic phase was dried over anhydrous magnesium sulfate, filtered, and the solvent was removed under vacuum to obtain a red byproduct. The crude product was dissolved in dichloromethane, dried over anhydrous magnesium sulfate, filtered, and the solvent was removed under vacuum to obtain 6 g of the product 9,10-anthracene dicarboxaldehyde, with a yield of 57.4%.

[0063]

[0064] 1.5 g (6.4 mmol) of 9,10-anthracene dicarboxaldehyde was added to a dry 500 mL round-bottom flask and dissolved in 50 mL of dry dichloromethane. 11.5 g (54.7 mmol) of 2,2,2-trimethoxy-4,5-dimethyl-1,3,2-dioxocyclophosphene was added dropwise to the round-bottom flask at room temperature using a constant-pressure dropping funnel. The reaction mixture remained a brownish-red solution with no significant change. The mixture was stirred overnight, and the reaction progress was monitored using thin-layer chromatography. The solvent was removed under reduced pressure, and 40 mL of anhydrous methanol was added. The mixture was refluxed at 80 °C for 6 h. The target product was obtained by column chromatography using a 1:9 (v / v) solution of ethyl acetate and petroleum ether as the eluent.

[0065]

[0066] Weigh 3.74 g (10.0 mmol) of anthracene diacetylacetone, 13.52 g (100.0 mmol) of 2,4,6-trimethylaniline, and 100 mg of p-toluenesulfonic acid into a 250 mL round-bottom flask. Add 120 mL of mesitylene and reflux to separate the water. Monitor the reaction progress by TLC (the reaction proceeds very slowly). After the reaction is complete, concentrate by rotary evaporation, and then use a 1:9 (v / v) solution of ethyl acetate and petroleum ether as eluent. Separate by column chromatography to obtain a pale yellow solid product, with a yield of 47%.

[0067]

[0068] Example 2

[0069] This embodiment uses the preparation of anthracene β-keto monoimine complexes with R1, R2, R3, and R4 as H and R5 as a sterically hindered phenyl group as an example. The specific preparation method is as follows:

[0070] Weigh 3.74 g (10.0 mmol) of anthracene diacetylacetone, 49.53 g (40.0 mmol) of sterically hindered aniline, and 100 mg of p-toluenesulfonic acid into a 250 mL round-bottom flask. Add 120 mL of mesitylene and reflux to separate the water. Monitor the reaction progress by TLC (the reaction proceeds very slowly). After the reaction is complete, concentrate by rotary evaporation and separate by column chromatography to obtain a pale yellow solid product, with a yield of 32%.

[0071]

[0072] Example 3

[0073] The anthracene β-keto monoimine metal complex in this embodiment has the following structural formula: .

[0074] The preparation method specifically includes the following steps:

[0075] 0.3051 g (0.5 mmol) of the anthracene ligand from Example 1 was placed in a 100 mL Schlenk flask and dissolved in 10 mL of toluene. The temperature was lowered to -40°C, and 0.189 g (1 mmol) of titanium tetrachloride was added. The color changed from colorless to orange-red, and upon returning to room temperature, the color turned yellow. The solvent was dried under reduced pressure, washed with n-hexane, and filtered to obtain a pale yellow powder solid with a yield of 61%.

[0076] Elem.Anal. 55.26% C, 4.75% H, while the calculated 55.12% C, 4.63% H.

[0077] Example 4

[0078] The anthracene β-keto monoimine metal complex in this embodiment has the following structural formula: .

[0079] The preparation method specifically includes the following steps:

[0080] 0.3051 g (0.5 mmol) of the anthracene ligand from Example 1 was placed in a 100 mL Schlenk flask and dissolved in 10 mL of toluene. The temperature was lowered to -40°C, and 0.2332 g (1 mmol) of zirconium tetrachloride was added. The color changed from colorless to orange-red, and upon returning to room temperature, the color turned yellow. The solvent was dried under reduced pressure, washed with n-hexane, and filtered to obtain a pale yellow powder solid with a yield of 63%.

[0081] Elem.Anal. 50.49% C, 4.46% H, while the calculated 50.35% C, 4.23% H.

[0082] Example 5

[0083] The anthracene β-keto monoimine metal complex in this embodiment has the following structural formula: .

[0084] The preparation method specifically includes the following steps:

[0085] 0.3051 g (0.5 mmol) of the anthracene ligand from Example 1 was placed in a 100 mL Schlenk flask and dissolved in 10 mL of toluene. The temperature was lowered to -40°C, and 0.3203 g (1 mmol) of hafnium tetrachloride was added. The color changed from colorless to orange-red, and upon returning to room temperature, the color turned yellow. The solvent was dried under reduced pressure, washed with n-hexane, and filtered to obtain a pale yellow powder solid with a yield of 60%.

[0086] Elem.Anal. 42.80% C, 3.56% H, while the calculated 42.88% C, 3.60% H.

[0087] Example 6

[0088] The anthracene β-keto monoimine metal complex in this embodiment has the following structural formula: .

[0089] The preparation method specifically includes the following steps:

[0090] 0.3051 g (0.5 mmol) of the anthracene ligand from Example 1 was placed in a 100 mL Schlenk flask and dissolved in 10 mL of toluene. The temperature was lowered to -40°C, and 0.4124 g (1 mmol) of tetrabenzyltitanium was added. The color changed from colorless to orange-red, and upon returning to room temperature, the color turned yellow. The solvent was dried under reduced pressure, washed with n-hexane, and filtered to obtain a pale yellow powder solid with a yield of 62%.

[0091] Elem.Anal. 80.86% C, 6.82% H, while the calculated 80.76% C, 6.78% H.

[0092] Example 7

[0093] The anthracene β-keto monoimine metal complex in this embodiment has the following structural formula: .

[0094] The preparation method specifically includes the following steps:

[0095] 0.3051 g (0.5 mmol) of the anthracene ligand from Example 1 was placed in a 100 mL Schlenk flask and dissolved in 10 mL of toluene. The temperature was lowered to -40°C, and 0.2242 g (1 mmol) of tetrakis(dimethylamino)titanium was added. The color changed from colorless to orange-red, and upon returning to room temperature, the color turned yellow. The solvent was dried under reduced pressure, washed with n-hexane, and filtered to obtain a pale yellow powder solid with a yield of 63%.

[0096] Elem.Anal. 67.21% C, 8.16% H, while the calculated 67.07% C, 8.13% H.

[0097] Example 8

[0098] The anthracene β-keto monoimine metal complex in this embodiment has the following structural formula: .

[0099] The preparation method specifically includes the following steps:

[0100] 0.417 g (0.5 mmol) of the anthracene ligand from Example 2 was placed in a 100 mL Schlenk flask and dissolved in 10 mL of toluene. The temperature was lowered to -40°C, and 0.189 g (1 mmol) of titanium tetrachloride was added. The color changed from colorless to orange-red, and upon returning to room temperature, the color turned yellow. The solvent was dried under reduced pressure, washed with n-hexane, and filtered to obtain a pale yellow powder solid with a yield of 52%.

[0101] Elem.Anal. 71.86% C, 5.69% H, while the calculated 71.94% C, 5.54% H.

[0102] Example 9

[0103] The anthracene β-keto monoimine metal complex in this embodiment has the following structural formula: .

[0104] The preparation method specifically includes the following steps:

[0105] 0.417 g (0.5 mmol) of the anthracene ligand from Example 2 was placed in a 100 mL Schlenk flask and dissolved in 10 mL of toluene. The temperature was lowered to -40°C, and 0.2242 g (1 mmol) of tetrakis(dimethylamino)titanium was added. The color changed from orange-red to yellow upon returning to room temperature. The solvent was dried under reduced pressure, washed with n-hexane, and filtered to obtain a pale yellow powder solid with a yield of 46%.

[0106] Elem.Anal. 78.36% C, 7.43% H, while the calculated 78.27% C, 7.52% H.

[0107] Example 10

[0108] The anthracene β-keto monoimine metal complex in this embodiment has the following structural formula: .

[0109] The preparation method specifically includes the following steps:

[0110] 0.417 g (0.5 mmol) of the anthracene ligand from Preparation Example 2 was placed in a 100 mL Schlenk flask and dissolved in 10 mL of toluene. The temperature was lowered to -40 °C, and 0.4124 g (1 mmol) of tetrabenzyltitanium was added. The color changed from colorless to orange-red, and upon returning to room temperature, the color turned yellow. The solvent was dried under reduced pressure, washed with n-hexane, and filtered to obtain a pale yellow powder solid with a yield of 48%.

[0111] Elem.Anal. 85.45% C, 6.86% H, while the calculated 85.34% C, 6.75% H.

[0112] Comparative Example 1

[0113] The catalyst involved in this comparative example is a typical non-metallocene catalyst, dimethyltitanium compound, with the following structural formula: .

[0114] The polymerization experiment was conducted as follows: Ethylene / propylene (co)polymerization was carried out in toluene using a 500 mL reactor. Toluene (250 mL) was introduced into the nitrogen-purged reactor, pressurized to 0.2 MPa with nitrogen, and heated to 110 °C. An ethylene / propylene mixture (ethylene:propylene = 6:4, molar ratio) was added to 0.6 MPa. After 10 minutes, under stirring, 1.0 mL of a 1.25 M toluene solution of MAO (methylaluminoxane) was added to the reactor (MAO addition amount was 1.25 mmol based on Al). Anthrayl β-keto monoimine metal complexes (5.0 μmol) Cat-1 (corresponding to Example 3), Cat-2 (corresponding to Example 4), Cat-3 (corresponding to Example 5), Cat-4 (corresponding to Example 6), Cat-5 (corresponding to Example 7), Cat-6 (corresponding to Example 8), Cat-7 (corresponding to Example 9), Cat-8 (corresponding to Example 10), and Cat-9 (dimethyltitanium compound in Comparative Example 1) were dissolved in 5 mL of anhydrous toluene and then added to the reactor to initiate copolymerization. After 0.5 hours, the gas feed was stopped, heating was stopped, and isobutanol (3 mL) was injected to stop the polymerization. After cooling to room temperature, the resulting mixture was poured into acidified methanol (1 L contains 2 mL of hydrochloric acid). The copolymer was collected by filtration, washed with methanol, and then vacuum dried at 130 °C for 10 hours. The polymerization results are shown in Table 1 below.

[0115] Table 1

[0116]

[0117] Where Mw is the weight-average molecular weight, in g / mol; Mw / Mn is the molecular weight distribution index.

[0118] As can be seen from the above results, the catalytic activity and molecular weight of the polymer synthesized in the examples (i.e., Cat-1~8) are higher than those of the comparative examples.

[0119] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A binuclear catalyst based on anthracene-β-ketomonimine, characterized in that, The binuclear catalyst has the general structural formula shown in equation (1): ； R1, R2, R3, and R4 are each independently selected from H, halogens, C1-C12 straight-chain or branched alkyl groups, C3-C8 cycloalkyl groups, C6-C15 substituted or unsubstituted aryl groups, or C6-C15 aralkyl groups; R5 is selected from C6-C15 substituted or unsubstituted aryl groups; R6 is selected from halogens, alkyl groups, aralkyl groups, amino groups, and alkoxy groups; M is selected from Ti, Zr, and Hf metals.

2. The binuclear catalyst based on anthracene β-keto monoimine according to claim 1, characterized in that, In the general formula (1) of the binuclear catalyst, R1, R2, R3, and R4 are each independently selected from H, halogens, C1-C8 straight-chain or branched alkyl groups, C5-C8 cycloalkyl groups, C6-C10 substituted or unsubstituted aryl groups, or C6-C10 aralkyl groups; R5 is selected from C6-C10 substituted or unsubstituted aryl groups; R6 is selected from halogens, alkyl groups, aralkyl groups, amino groups, and alkoxy groups; M is selected from Ti, Zr, and Hf metals.

3. The binuclear catalyst based on anthracene β-ketomonimine according to claim 1, characterized in that, In the general formula (1) of the binuclear catalyst, R1, R2, R3, and R4 are each independently selected from methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, n-pentyl, isopentyl, n-hexyl, isohexyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, phenyl, p-tolyl, o-tolyl, or benzyl; R5 is selected from substituted or unsubstituted aryl groups; R6 is selected from halogen, alkyl, aralkyl, amine, and alkoxy groups; and M is selected from Ti, Zr, and Hf metals.

4. A method for preparing a binuclear catalyst, characterized in that, The binuclear catalyst is the anthracene β-keto monoimine-based binuclear catalyst according to any one of claims 1-3, and the preparation method includes the following steps: The anthraquinone monoimide complex shown in formula (2) is reacted with a metal compound containing titanium, zirconium, or hafnium in an organic solvent. After the reaction is complete, the mixture is washed, filtered, and dried to obtain the final product. The reaction equations for the coordination compounds and metal compounds are as follows: ， Wherein, R1, R2, R3, R4, and R5 are defined as described in claim 1; MX4, where M is metal Ti, Zr, or Hf, and X is a halogen; M(R6)4, where M is metal Ti, Zr, or Hf, and R is dimethylamino or benzyl.

5. The preparation method according to claim 4, characterized in that, The molar ratio of the anthracene β-keto monoimine complex to the metal compound is 1:1 to 1:3; preferably, the molar ratio is 1:1 to 1:1.5; and / or The reaction temperature of anthracene β-keto monoimine complexes with metal compounds is not higher than 0°C; preferably, the reaction temperature is -40 to 0°C; and / or The reaction time of the anthracene β-keto monoimine complex with the metal compound is 18-24 h; preferably, the reaction time is 20-24 h.

6. The preparation method according to claim 4, characterized in that, The preparation of the compound shown in formula (2) includes the following steps: 9,10-Anthracene dicarboxaldehyde was reacted with 2,2,2-trimethoxy-4,5-dimethyl-1,3,2-dioxocyclophosphene in a solvent at room temperature to give anthracene diacetylacetone. Anthracene diacetylacetone was mixed with aniline and p-toluenesulfonic acid, and then thiamethoxam was added and the mixture was refluxed to remove water. After the reaction was completed, the compound shown in formula (2) was obtained by separation.

7. The preparation method according to claim 6, characterized in that, The preparation of the compound shown in formula (2) includes the following steps: 9,10-Anthracene dicarboxaldehyde was dissolved in dichloromethane, and 2,2,2-trimethoxy-4,5-dimethyl-1,3,2-dioxocyclophosphene was added dropwise at room temperature. After the addition was complete, the mixture was stirred overnight. The reaction progress was detected by thin-layer chromatography. After the reaction was complete, the solvent was removed under reduced pressure, anhydrous ethanol was added, and the mixture was refluxed to separate anthracene diacetylacetone. Anthracene diacetylacetone, aniline, and p-toluenesulfonic acid were mixed, and thiamethoxam was added and refluxed to remove water. After the reaction was completed, the mixture was concentrated by rotary evaporation and separated by column chromatography to obtain a light yellow solid product, namely the compound shown in formula (2).

8. The preparation method according to claim 6 or 7, characterized in that, In the preparation steps of the compound shown in formula (2), the molar ratio of 9,10-anthracene dicarboxaldehyde to 2,2,2-trimethoxy-4,5-dimethyl-1,3,2-dioxocyclophosphene is 1:(5-12), and the molar ratio of anthracene diacetylacetone to aniline is 1:(1-20).

9. An olefin polymerization catalyst, characterized in that, It includes a main catalyst and a co-catalyst, wherein the main catalyst is the anthracene β-keto monoimine-based binuclear catalyst as described in claim 1, and the co-catalyst is organoaluminum.

10. A method for olefin polymerization, characterized in that, It includes at least the step of catalyzing olefin polymerization using the olefin polymerization catalyst of claim 9.

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