A bulky diimine nickel catalyst, its preparation and use

Abstract

The present application provides a class of bulky α The application relates to a preparation method of a diimine nickel catalyst and application of the diimine nickel catalyst in preparation of polyethylene and ethylene / methyl acrylate copolymer. Different substituted ortho-diaryl groups are introduced into the diimine nickel system, the space effect is used to effectively protect the metal nickel center, and the electronic effect of different substitutions is further used to adjust the polymerization capacity of the catalyst. The synthesized nickel catalyst can efficiently realize ethylene homogeneous polymerization, and greatly improves the thermal stability, catalytic activity and polymer molecular weight of the catalyst. In the ethylene polymerization, the catalyst has high activity, and high-molecular-weight branched polyethylene is obtained. Very importantly, the catalyst effectively realizes the copolymerization of ethylene and methyl acrylate, and copolymer with different polar monomer insertion rates is obtained. The nickel catalyst of the present application has important industrial application value in the field of olefin polymerization.

Description

Technical Field

[0001] This invention belongs to the field of olefin polymerization technology, and relates to a metal catalyst for catalyzing olefin polymerization, its preparation method and its application in catalyzing ethylene homopolymerization, and also relates to its application in ethylene / polar monomer coordination copolymerization. Background Technology

[0002] Polyolefins generally refer to thermoplastic resins such as ethylene, propylene, and norbornene. They have many advantages, such as abundant raw materials, low price, good high temperature resistance, easy processing and molding, and excellent comprehensive performance. Therefore, polyolefin materials are widely used in building materials, electrical components, household products, transportation, industrial and agricultural films and other industries.

[0003] Since Brookhart et al. first reported in 1995 that nickel- and palladium-based diimine catalysts could be used to produce high molecular weight polyethylene (LK Johnson, CM Killian, M. Brookhart, New Pd(II)- and Ni(II)-based catalysts for polymerization of ethylene and α (e.g., olefins, J. Am. Chem. Soc. 1995, 117, 6414.) Since then, these olefin polymerization catalysts have been extensively studied. Although they possess excellent performance, their lack of thermal stability limits industrial production. At high temperatures, these catalysts rapidly decompose, leading to loss of activity, and their activity in copolymerization is greatly reduced, resulting in a significant decrease in molecular weight.

[0004] Catalysts are the core of olefin polymerization, and developing new catalysts is key to achieving high-performance polyolefins. Further research has found that catalysts with camphor-based diimide skeletons have shown the ability to polymerize ethylene at temperatures up to 80°C, but they slowly deactivate during polymerization. In pursuit of catalysts with higher thermal stability, Long and colleagues (Rhinehart JL, Brown LA, Long BK. A Robust Ni(II)) α-Diimine Catalyst for High Temperature Ethylene Polymerization[J]. Journal of the American Chemical Society, 2013, 135(44):16316-9.) reported in 2013 space-crowded catalysts that are active at ethylene polymerization temperatures up to 100°C, while generating high molecular weight polymers. Diimine nickel and palladium catalysts also show good results in catalyzing the copolymerization of ethylene with polar monomers. Zou W, Chen C. Influence of Backbone Substituents on the Ethylene (Co) polymerization Properties of α -diimine Pd (II) and Ni (II) Catalysts[J]. Organometallics, 2016, 35(11):1794-1801.) Synthesize a series of compounds with diacetone and acenaphthoquinone skeletons. α The effects of 1-diimine ligands and their corresponding palladium and nickel catalysts on the copolymerization and properties of ethylene-methyl acrylate were studied, and good results were obtained. Summary of the Invention

[0005] Therefore, this invention provides a bulky nickel diimine catalyst, its preparation method, and its application. The catalyst has a bulky acenaphthoquinone framework. α -Diimine nickel complexes exhibit high thermal stability and activity in olefin polymerization, and the polymers prepared have ultra-high molecular weight and low branching degree.

[0006] There are no particular restrictions on the source of any raw materials used in this invention; they can be purchased from the market or prepared using conventional methods known to those skilled in the art.

[0007] There are no particular restrictions on the purity of any raw materials used in this invention, but analytical grade is preferred.

[0008] This invention contains a bulky diimine nickel catalyst, which is a catalyst with a bulky acenaphthoquinone framework. α - Diimine nickel complex, structure as shown in (Ⅰ): Wherein, R1 is independent of methanol, ethanol, 1-hexanol, and isooctanol; R2 is independent of methyl, isopropyl, and tert-butyl; and R3 is independent of hydrogen, methyl, and methoxy.

[0009] The present invention also provides a method for preparing the complex of the above formula (I), the method being as follows: Step (1) Synthesis of compound (II): Under a nitrogen atmosphere, 4-bromophenol and triphenylphosphine were added to a solvent and placed in a low-temperature stirrer. 1.2 equivalents of the corresponding alcohol and diisopropyl azodicarbonate were added and stirred for 5-25 min. Then, the mixture was stirred overnight at room temperature. The solvent was evaporated, petroleum ether was added to precipitate the solid, the solid was filtered off, the filtrate was evaporated, and the product, compound (II), was obtained by column chromatography. The reaction formula is as follows: Where R1 represents methanol, ethanol, 1-hexanol, and isooctanol; Step (2) Synthesis of compound (III): Under a nitrogen atmosphere, dissolve compound (II) in a solvent and place it in a low-temperature stirrer. Add n-butyllithium and react for 1-2 h. Then add benzaldehyde with the para-substituent and react for 1-2 h. Stir overnight at room temperature, evaporate the solvent, extract three times with CH2Cl2, and dry with anhydrous magnesium sulfate. Filter off the magnesium sulfate, evaporate the filtrate to dryness, and obtain the product (compound (III)) by column chromatography. The reaction formula is as follows: Where R1 represents methanol, ethanol, 1-hexanol, and isooctanol; and R2 represents methyl, isopropyl, and tert-butyl. Step (3) Synthesis of compound (IV): Take 2.5 equivalents of formula (III) and aniline with the corresponding substituents, heat to 120℃, slowly add concentrated hydrochloric acid solution of zinc chloride, then raise the temperature to 160℃ and react for 1~2 h. Cool the reactants to room temperature, extract three times with CH2Cl2, and dry with anhydrous magnesium sulfate. Filter off the magnesium sulfate, evaporate the filtrate to dryness, and separate the product, i.e., compound (IV), by column chromatography. The reaction formula is as follows: Wherein, R1 is independent of methanol, ethanol, 1-hexanol, and isooctanol; R2 is independent of methyl, isopropyl, and tert-butyl; and R3 is independent of hydrogen, methyl, and methoxy. Step (4) Synthesis of compound (V): Dissolve acenaphthene and zinc chloride in a solvent, stir at 140°C and add aniline obtained from formula (IV). After reacting for 3-5 h, cool to room temperature, add methanol to precipitate the solid, filter, wash with methanol, dissolve the solid in a solvent, add potassium oxalate, stir overnight at room temperature, extract three times with CH2Cl2, dry with anhydrous magnesium sulfate, filter off the magnesium sulfate, concentrate the filtrate, recrystallize with methanol to obtain the product, compound (V), with the following reaction formula: Wherein, R1 is independent of methanol, ethanol, 1-hexanol, and isooctanol; R2 is independent of methyl, isopropyl, and tert-butyl; and R3 is independent of hydrogen, methyl, and methoxy. Step (5) Synthesis of Formula (I) Complex: Under a nitrogen atmosphere, the compound synthesized in step (4) is reacted with (DME)NiBr2 in a solvent at a 1:1 equivalent ratio for 6-12 h. After filtration, washing, and drying, the acenaphthoquinone skeleton is synthesized. α -Diimine nickel complex (VI), reaction formula is as follows: Wherein, R1 is independent of methanol, ethanol, 1-hexanol, and isooctanol; R2 is independent of methyl, isopropyl, and tert-butyl; R3 is independent of hydrogen, methyl, and methoxy; DME = 1,2-dimethoxyethane.

[0010] Generally, the solvents used in steps (1), (2), (4), and (5) are one or a mixture of several of tetrahydrofuran, acetic acid, dichloromethane, petroleum ether, and ethyl acetate.

[0011] This invention provides a class of large-volume α - Diimine ligands and nickel catalysts: These catalysts have large steric hindrance, which can effectively inhibit chain transfer. They also have high activity, high activity at high temperatures, and good thermal stability. They can be used to prepare ultra-high molecular weight polyethylene and have high activity and insertion rate in the copolymerization of ethylene and polar monomers.

[0012] (1) Ethylene homopolymerization Solvent and co-catalyst were added to a 350 mL pressure-resistant bottle under anhydrous and oxygen-free conditions. The pressure-resistant bottle was connected to a high-pressure polymerization pipeline and ethylene was introduced. Then, the complex dissolved in the solvent was injected through a syringe. The ethylene pressure was controlled at 1~20 atm, the reaction temperature at 0~120 ℃, and the reaction time at 5~30 min. After the reaction was completed, an alcohol solution containing hydrochloric acid was added to quench the reaction. The mixture was then filtered and dried to obtain polyethylene.

[0013] The co-catalyst is MAO, MMAO, or AlEt2Cl.

[0014] The solvent is toluene, n-heptane, or dichloromethane; the amount of the co-catalyst and complex is 100-500; the alcohol solution containing hydrochloric acid is a methanol solution with a hydrochloric acid concentration of 5 wt% or higher, or an ethanol solution with a hydrochloric acid concentration of 5 wt% or higher.

[0015] (2) Copolymerization of ethylene with polar monomers Solvent and co-catalyst were added to a 350 mL pressure vessel under anhydrous and oxygen-free conditions. The pressure vessel was connected to a high-pressure polymerization pipeline and ethylene was introduced. The complex dissolved in the solvent was then injected through a syringe, followed by the injection of the polar monomer. The ethylene pressure was controlled at 1–5 atm, the reaction temperature at 0–100 °C, and the reaction time at 1–12 h. After the reaction was completed, an alcohol solution containing hydrochloric acid was added to quench the reaction. The mixture was then filtered, dried, and the copolymer was obtained.

[0016] The co-catalyst is MAO, MMAO, or AlEt2Cl.

[0017] The solvent is toluene, n-heptane, or dichloromethane; the amount of the co-catalyst and complex is 100-500; the alcohol solution containing hydrochloric acid is a methanol solution with a hydrochloric acid concentration of 5 wt% or higher, or an ethanol solution with a hydrochloric acid concentration of 5 wt% or higher.

[0018] The polar monomer is one or more of the following: methyl methacrylate, methyl acrylate, methyl 10-undecenoate, 10-undecen-1-ol, allyltrimethoxysilane, allyl chloride, 6-chloro-1-hexene, styrene, allylbenzene, ethyl allyl ether, and vinyl ethyl ether.

[0019] This invention introduces ortho- and tertiary alkyl groups with different substitutions into a nickel diimine system, effectively protecting the nickel center pair through steric effects, and further utilizing the electronic effects of different substitutions to adjust the catalyst's polymerization ability. The synthesized nickel catalyst can efficiently achieve homogeneous polymerization of ethylene, significantly improving the catalyst's thermal stability, catalytic activity, and polymer molecular weight. In ethylene polymerization, the catalyst exhibits high activity, yielding high-molecular-weight polyethylene with different branching structures. Importantly, this type of catalyst effectively achieves the copolymerization of ethylene and methyl acrylate, obtaining copolymers with monomer insertion rates of different polarities. The non-polarity of polyolefins has always been a significant challenge limiting their application. Therefore, the nickel-based catalyst of this invention has important industrial application value in the field of olefin polymerization. Attached Figure Description

[0020] Figure 1 The 1H NMR spectrum of the homopolymer prepared according to an example of the present invention.

[0021] Figure 2 The proton NMR spectrum of the copolymer prepared according to an example of the present invention. Detailed Implementation

[0022] To better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to embodiments. However, it should be understood that these descriptions are only for further illustrating the features and advantages of the present invention, and are not intended to limit the scope of the claims of the present invention.

[0023] Example 1 Preparation of complex formula (1)-1 (Formula (1)-1, where R1 is isooctyl alcohol, R2 is tert-butyl, and R3 is methoxy).

[0024] Step 1: Under a nitrogen atmosphere, 4-bromophenol (0.17 g, 1.0 mmol) and triphenylphosphine (0.34 g, 1.3 mmol) were added to 40 mL of tetrahydrofuran and placed in a low-temperature stirrer. Isooctyl alcohol (0.16 g, 1.2 mmol) and diisopropyl azodicarbonate (0.24 g, 1.2 mmol) were added and stirred for 15 min. Then, the mixture was stirred overnight at room temperature. The tetrahydrofuran was evaporated to dryness, and petroleum ether (100 mL) was added to precipitate the solid. The solid was filtered, and the filtrate was evaporated to dryness. The product (II) was obtained by column chromatography (PE / EA = 100 / 1) (70% yield). 1 ¹H NMR (400 MHz, CDCl₃, ppm) d 7.4 - 7.34 (m, 2H), 6.79 (dd, J= 9.0, 1.2 Hz, 2H), 3.81 (d, J = 5.8 Hz, 2H), 1.73 (dt, J = 12.1, 5.2 Hz,1H), 1.55 - 1.26 (m, 8H), 0.98 - 0.87 (m, 6H). 13 C NMR (100 MHz, CDCl3) d 158.53, 132.17, 116.33, 112.48, 77.37, 77.06, 76.74, 70.75, 39.35, 31.64, 30.51, 29.10, 26.96, 23.85, 23.08, 22.71, 14.17, 14.12, 11.12.

[0025] Step 2: Under a nitrogen atmosphere, dissolve formula (II) (0.29 g, 1 mmol) in tetrahydrofuran (50 mL) and place at -78 °C. Add n-butyllithium (0.48 mL, 1.2 mmol) and react for 2 h. Then add p-tert-butylbenzaldehyde (0.16 g, 1 mmol) and continue the reaction for 1 h. Stir overnight at room temperature, evaporate tetrahydrofuran to dryness, extract three times with CH2Cl2 (3 × 30 mL), and dry with anhydrous magnesium sulfate. Filter off the magnesium sulfate, evaporate the filtrate to dryness, and separate by column chromatography (PE / EA = 50 / 1) to obtain product (III) (75% yield). 1¹H NMR (400 MHz, CDCl₃, ppm) d 7.88 - 7.78 (m, 2H), 7.77 -7.65 (m, 2H), 7.54 - 7.41 (m, 2H), 7.02 - 6.88 (m, 2H), 3.93 (dd, J = 5.7,1.2 Hz, 2H), 1.82 - 1.72 (m, 1H), 1.57 - 1.24 (m, 18H), 1.01 - 0.83 (m, 7H). 13 C NMR (100 MHz, CDCl3) d 195.30, 162.96, 155.48, 135.58, 132.49, 130.14, 129.83, 125.14, 113.97, 77.41, 77.09, 76.77, 70.69, 53.45, 39.32, 35.05, 31.20, 30.50, 29.09, 23.84, 23.06, 22.73, 14.12, 11.14.

[0026] Step 3: Take formula (Ⅲ) (0.92 g, 2.5 mmol) and p-methoxyaniline (0.12 g, 1 mmol), heat to 120 °C, slowly add concentrated hydrochloric acid solution of zinc chloride, then heat to 160 °C and react for 1 h. Cool the reaction mixture to room temperature, extract three times with CH2Cl2 (3 × 30 mL), dry with anhydrous magnesium sulfate, filter off the magnesium sulfate, evaporate the filtrate to dryness, and separate by column chromatography (PE / EA = 50 / 1) to obtain product (Ⅳ) (50% yield). 1 ¹H NMR (400 MHz, CDCl₃, ppm) d 7.28(d, J = 1.8 Hz, 2H), 7.27 (d, J = 2.0 Hz, 2H), 7.03 - 6.97 (m, 8H), 6.83 -6.78 (m, 4H), 6.21 (s, 2H), 5.39 (s, 2H), 3.82 - 3.78 (m, 4H), 3.45 (s, 3H), 1.70 (dt, J = 12.2, 5.8 Hz, 2H), 1.36 - 1.25 (m, 31H), 1.00 - 0.84 (m, 15H). 13 C NMR (100 MHz, CDCl3) d158.04, 151.70, 149.20, 139.83, 135.94, 134.43, 131.37, 131.34, 130.95, 130.33, 129.02, 128.86, 127.75, 126.14, 125.30, 114.42, 114.40, 114.06, 77.36, 77.04, 76.73, 70.40, 70.37, 65.60, 55.18, 51.22, 39.44, 34.40, 31.40, 30.55, 29.12, 23.87, 23.08, 19.21, 14.13, 13.77, 11.15, 0.03.

[0027] Step 4: Dissolve acenaphthene (0.18 g, 1 mmol) and zinc chloride (0.15 g, 1.1 mmol) in acetic acid (10 mL), stir at 140 °C and add aniline (1.73 g, 2.1 mmol) obtained from formula (Ⅳ). After reacting for 4 h, cool to room temperature, add methanol (10 mL) to precipitate the solid, filter, wash with methanol (50 mL), dissolve the solid in dichloromethane, add potassium oxalate (0.46 g, 2.5 mmol) aqueous solution, stir overnight at room temperature, extract three times with CH2Cl2 (3 × 30 mL), dry with anhydrous magnesium sulfate, filter off the magnesium sulfate, concentrate the filtrate, recrystallize with methanol to obtain product (Ⅴ) (45% yield). 1 ¹H NMR (400MHz, CDCl₃, ppm) d 7.51 - 7.38 (m, 2H), 7.19 - 7.12 (m, 4H), 7.08 - 6.94 (m,10H), 6.87 - 6.57 (m, 21H), 6.23 - 6.09 (m, 5H), 5.70 - 5.56 (m, 4H), 3.80 -3.64 (m, 11H), 3.41 (d, J = 27.9 Hz, 3H), 1.76 - 1.62 (m, 3H), 1.42 - 1.27(m, 36H), 1.24 (d, J = 3.6 Hz, 21H), 0.95 - 0.82 (m, 37H). 13 C NMR (100 MHz, CDCl3) d157.57, 157.07, 155.53, 148.46, 148.00, 142.81, 140.53, 139.84, 130.68, 130.38, 129.32, 129.04, 126.55, 124.96, 124.58, 114.11, 114.03, 113.66, 77.38, 77.06, 76.74, 70.36, 69.97, 55.26, 50.24, 39.36, 34.29, 33.96, 33.88, 31.39, 31.13, 31.08, 30.54, 29.09, 23.83, 23.11, 14.15, 11.23, 11.13, 1.06.

[0028] Step 5: Under a nitrogen atmosphere, compound (V) was reacted with (DME)NiBr2 in dichloromethane at a 1:1 equivalence ratio for 10 h. After filtration through diatomaceous earth, washing with dichloromethane, and drying, the acenaphthoquinone skeleton was synthesized. α -Diimine nickel complex (VI) (80% yield). Elemental analysis: C, 75.18; H, 7.81; N, 1.39.

[0029] Example 2 Preparation of complex (1)-2 (Formula (1)-2, where R1 is 1-hexanol, R2 is tert-butyl, and R3 is methoxy).

[0030] Step 1: Under a nitrogen atmosphere, 4-bromophenol (0.17 g, 1.0 mmol) and triphenylphosphine (0.34 g, 1.3 mmol) were added to 40 mL of tetrahydrofuran and placed in a low-temperature stirrer. 1-Hexanol (0.12 g, 1.2 mmol) and diisopropyl azodicarbonate (0.24 g, 1.2 mmol) were added and stirred for 15 min. The mixture was then stirred overnight at room temperature. The tetrahydrofuran was evaporated to dryness, and petroleum ether (100 mL) was added to precipitate the solid. The solid was filtered, and the filtrate was evaporated to dryness. The product (II) was obtained by column chromatography (PE / EA = 100 / 1) (78% yield). 1 ¹H NMR (400 MHz, CDCl₃, ppm) d7.44 - 7.32 (m, 2H), 6.84 -6.68 (m, 2H), 3.91 (t, J = 6.6 Hz, 2H), 1.88 - 1.65 (m, 2H), 1.52 - 1.27 (m,6H), 1.02 - 0.80 (m, 3H). 13 C NMR (100 MHz, CDCl3) d 158.27, 132.20, 116.30, 112.55, 77.38, 77.06, 76.74, 68.26, 31.60, 29.17, 25.71, 22.63, 14.07.

[0031] Step 2: Under a nitrogen atmosphere, dissolve formula (II) (0.26 g, 1 mmol) in tetrahydrofuran (50 mL) and place at -78 °C. Add n-butyllithium (0.48 mL, 1.2 mmol) and react for 2 h. Then add p-tert-butylbenzaldehyde (0.16 g, 1 mmol) and continue the reaction for 1 h. Stir overnight at room temperature, evaporate tetrahydrofuran to dryness, extract three times with CH2Cl2 (3 × 30 mL), and dry with anhydrous magnesium sulfate. Filter off the magnesium sulfate, evaporate the filtrate to dryness, and separate by column chromatography (PE / EA = 50 / 1) to obtain product (III) (73% yield). 1 ¹H NMR (400 MHz, CDCl₃, ppm) d 7.36 - 7.31 (m, 2H), 7.30 -7.22 (m, 4H), 6.90 - 6.76 (m, 2H), 5.74 (s, 1H), 4.00 - 3.84 (m, 2H), 1.84 -1.69 (m, 2H), 1.51 - 1.18 (m, 15H), 0.96 - 0.81 (m, 3H). 13 C NMR (100 MHz, CDCl3) d 158.57, 150.30, 141.22, 136.09, 136.07, 127.83, 126.95, 126.21, 125.52, 125.37, 114.41, 77.42, 77.10, 76.79, 75.67, 68.04, 34.53, 31.64, 31.41, 29.29, 25.78, 22.67, 14.11.

[0032] Step 3: Take formula (Ⅲ) (0.85 g, 2.5 mmol) and p-methoxyaniline (0.12 g, 1 mmol), heat to 120 °C, slowly add concentrated hydrochloric acid solution of zinc chloride, then heat to 160 °C and react for 1 h. Cool the reaction mixture to room temperature, extract three times with CH2Cl2 (3 × 30 mL), dry with anhydrous magnesium sulfate, filter off the magnesium sulfate, evaporate the filtrate to dryness, and separate by column chromatography (PE / EA = 50 / 1) to obtain product (Ⅳ) (55% yield). 1 ¹H NMR (400 MHz, CDCl₃, ppm) d 7.27(d, J = 2.0 Hz, 2H), 7.25 (s, 2H), 6.99 (d, J = 8.0 Hz, 8H), 6.84 - 6.75 (m,4H), 6.19 (d, J = 1.1 Hz, 2H), 5.38 (s, 2H), 3.99 - 3.83 (m, 4H), 3.44 (d, J= 0.9 Hz, 3H), 1.82 - 1.68 (m, 4H), 1.49 - 1.12 (m, 32H), 0.90 (d, J = 2.3Hz, 4H). 13 C NMR (100 MHz, CDCl3) d 157.86, 151.79, 149.24, 139.88, 139.86, 136.02, 134.63, 134.60, 131.42, 131.40, 130.96, 130.43, 129.09, 128.90, 125.34, 125.33, 124.85, 114.46, 114.44, 114.15, 113.97, 111.22, 77.44, 77.13, 76.81, 67.96, 65.60, 55.18, 51.29, 35.51, 34.44, 31.68, 31.46, 30.66, 29.38, 26.99, 26.51, 25.84, 25.68, 22.68, 19.27, 14.12, 13.81.

[0033] Step 4: Dissolve acenaphthene (0.18 g, 1 mmol) and zinc chloride (0.15 g, 1.1 mmol) in acetic acid (10 mL), stir at 140 °C and add aniline (1.61 g, 2.1 mmol) obtained from formula (Ⅳ). After reacting for 4 h, cool to room temperature, add methanol (10 mL) to precipitate the solid, filter, wash with methanol (50 mL), dissolve the solid in dichloromethane, add potassium oxalate (0.46 g, 2.5 mmol) aqueous solution, stir overnight at room temperature, extract three times with CH2Cl2 (3 × 30 mL), dry with anhydrous magnesium sulfate, filter off the magnesium sulfate, concentrate the filtrate, recrystallize with methanol to obtain product (Ⅴ) (40% yield). 1 ¹H NMR (400MHz, CDCl₃, ppm) d 7.55 - 7.39 (m, 2H), 7.21 - 7.09 (m, 5H), 7.08 - 6.92 (m,9H), 6.90 - 6.63 (m, 18H), 6.58 (ddd, J = 8.3, 4.0, 2.7 Hz, 2H), 6.27 - 6.03(m, 6H), 5.69 - 5.56 (m, 4H), 3.91 - 3.81 (m, 4H), 3.73 - 3.62 (m, 6H), 3.60- 3.41 (m, 3H), 3.31 - 3.22 (m, 1H), 1.78 - 1.69 (m, 5H), 1.64 - 1.51 (m,5H), 1.47 - 1.39 (m, 5H), 1.37 - 1.29 (m, 20H), 1.24 (dt, J = 2.7, 1.4 Hz,18H), 0.97 (dd, J = 5.4, 2.3 Hz, 7H), 0.91 (ddd, J = 7.7, 3.8, 2.3 Hz, 21H). 13 C NMR (100 MHz, CDCl3) d164.41, 157.30, 157.27, 156.85, 156.71, 155.51, 148.48, 148.06, 147.99, 142.79, 140.73, 140.45, 135.99, 134.35, 133.52, 130.70, 130.67, 130.39, 130.37, 129.33, 129.26, 129.04, 129.00, 128.36, 127.54, 126.55, 124.97, 124.93, 124.59, 124.54, 114.03, 113.97, 113.67, 113.59, 88.01, 77.26, 77.05, 76.84, 67.89, 67.87, 67.52, 67.41, 55.25, 55.23, 55.20, 50.34, 50.30, 50.23, 50.11, 34.28, 33.94, 33.85, 31.66, 31.64, 31.62, 31.52, 31.37, 31.36, 31.10, 31.03, 30.57, 30.13, 29.71, 29.30, 29.24, 29.22, 25.80, 25.78, 25.77, 22.66, 22.64, 19.20, 14.08.

[0034] Step 5: Under a nitrogen atmosphere, compound (V) was reacted with (DME)NiBr2 in dichloromethane at a 1:1 equivalence ratio for 10 h. After filtration through diatomaceous earth, washing with dichloromethane, and drying, the acenaphthoquinone skeleton was synthesized. α -Diimine nickel complex (VI) (85% yield). Elemental analysis: C, 74.56; H, 7.42; N, 1.47.

[0035] Example 3 Preparation of complex (1)-3 (Formula (1)-3, where R1 is ethanol, R2 is tert-butyl, and R3 is methoxy).

[0036] Step 1: Under a nitrogen atmosphere, 4-bromophenol (0.17 g, 1.0 mmol) and triphenylphosphine (0.34 g, 1.3 mmol) were added to 40 mL of tetrahydrofuran and placed in a low-temperature stirrer. Ethanol (0.06 g, 1.2 mmol) and diisopropyl azodicarbonate (0.24 g, 1.2 mmol) were added and stirred for 15 min. Then, the mixture was stirred overnight at room temperature. The tetrahydrofuran was evaporated to dryness, and petroleum ether (100 mL) was added to precipitate the solid. The solid was filtered, and the filtrate was evaporated to dryness. The product (II) was obtained by column chromatography (PE / EA = 100 / 1) (75% yield). 1 ¹H NMR (400 MHz, CDCl₃, ppm) d 7.43 - 7.30 (m, 2H), 6.77 (dd, J= 8.5, 1.3 Hz, 2H), 4.06 - 3.92 (m, 2H), 1.48 - 1.36 (m, 3H). 13 C NMR (100MHz, CDCl 3 ) d 158.14, 137.35, 137.25, 133.91, 133.72, 132.26, 128.81, 128.63, 128.56, 116.32, 112.65, 77.56, 77.24, 76.92, 63.68, 14.84.

[0037] Step 2: Under a nitrogen atmosphere, dissolve formula (II) (0.20 g, 1 mmol) in tetrahydrofuran (50 mL) and place at -78 °C. Add n-butyllithium (0.48 mL, 1.2 mmol) and react for 2 h. Then add p-tert-butylbenzaldehyde (0.16 g, 1 mmol) and continue the reaction for 1 h. Stir overnight at room temperature, evaporate tetrahydrofuran to dryness, extract three times with CH2Cl2 (3 × 30 mL), and dry with anhydrous magnesium sulfate. Filter off the magnesium sulfate, evaporate the filtrate to dryness, and separate by column chromatography (PE / EA = 50 / 1) to obtain product (III) (74% yield). 1 ¹H NMR (400 MHz, CDCl₃, ppm) d 7.39 - 7.30 (m, 2H), 7.29 -7.20 (m, 4H), 6.85 - 6.80 (m, 2H), 5.72 (s, 1H), 3.98 (q, J = 7.0 Hz, 2H), 1.41 - 1.24 (m, 12H). 13 C NMR (100 MHz, CDCl3) d 158.40, 158.33, 150.49, 150.18, 150.07, 141.43, 139.66, 138.16, 136.45, 135.72, 134.48, 128.90, 128.74, 128.65, 128.01, 127.76, 127.10, 127.02, 126.95, 126.40, 125.45, 125.35, 114.45, 81.96, 79.36, 77.64, 77.32, 77.00, 75.56, 70.27, 64.81, 63.51, 34.63, 34.59, 31.55, 14.98.

[0038] Step 3: Take formula (III) (0.71 g, 2.5 mmol) and p-methoxyaniline (0.12 g, 1 mmol), heat to 120 °C, slowly add concentrated hydrochloric acid solution of zinc chloride, then heat to 160 °C and react for 1 h. Cool the reaction mixture to room temperature, extract three times with CH2Cl2 (3 × 30 mL), dry with anhydrous magnesium sulfate, filter off the magnesium sulfate, evaporate the filtrate to dryness, and separate by column chromatography (PE / EA = 50 / 1) to obtain product (IV) (53% yield). 1 ¹H NMR (400 MHz, CDCl₃, ppm) d 7.30- 7.23 (m, 5H), 7.03 - 6.97 (m, 7H), 6.82 - 6.77 (m, 4H), 6.19 (d, J = 1.8Hz, 2H), 5.38 (s, 2H), 4.03 - 3.94 (m, 4H), 3.44 (d, J = 1.2 Hz, 3H), 1.44 -1.36 (m, 6H), 1.29 (d, J = 1.1 Hz, 19H). 13 C NMR (100 MHz, CDCl3) d 157.61,151.77, 149.24, 139.76, 135.92, 134.69, 134.65, 131.39, 130.40, 129.03,125.29, 114.40, 114.11, 77.35, 77.03, 76.72, 63.35, 55.17, 51.22, 34.40,31.39, 14.90.

[0039] Step 4: Dissolve acenaphthene (0.18 g, 1 mmol) and zinc chloride (0.15 g, 1.1 mmol) in acetic acid (10 mL), stir at 140 °C and add aniline (1.38 g, 2.1 mmol) obtained from formula (Ⅳ). After reacting for 4 h, cool to room temperature, add methanol (10 mL) to precipitate the solid, filter, wash with methanol (50 mL), dissolve the solid in dichloromethane, add potassium oxalate (0.46 g, 2.5 mmol) aqueous solution, stir overnight at room temperature, extract three times with CH2Cl2 (3 × 30 mL), dry with anhydrous magnesium sulfate, filter off the magnesium sulfate, concentrate the filtrate, recrystallize with methanol to obtain product (Ⅴ) (38% yield). 1 ¹H NMR (400MHz, CDCl₃, ppm) d 7.56 - 7.40 (m, 2H), 7.22 - 7.10 (m, 4H), 7.08 - 6.48 (m,29H), 6.34 - 5.92 (m, 7H), 5.71 - 5.52 (m, 4H), 3.94 (q, J = 8.0, 7.5 Hz, 4H), 3.72 - 3.33 (m, 10H), 1.36 (t, J = 6.9 Hz, 6H), 1.29 - 1.16 (m, 42H). 13 CNMR (100 MHz, CDCl3) d 155.62, 148.52, 130.72, 130.42, 129.28, 129.03, 124.98, 124.55, 114.04, 113.75, 63.30, 55.25, 50.35, 34.28, 33.85, 31.94, 31.64, 31.38, 31.11, 31.02, 14.91, 14.76, 14.13.

[0040] Step 5: Under a nitrogen atmosphere, compound (V) was reacted with (DME)NiBr2 in dichloromethane at a 1:1 equivalence ratio for 10 h. After filtration through diatomaceous earth, washing with dichloromethane, and drying, the acenaphthoquinone skeleton was synthesized. α -Diimine nickel complex (VI) (85% yield). Elemental analysis: C, 73.08; H, 6.19; N, 1.67.

[0041] Application Example 1 Applications of catalytic ethylene polymerization Under anhydrous and oxygen-free conditions, a magnetic stir bar, 20 mL of n-heptane, and the co-catalyst Et2AlCl were added to a 350 mL pressure-resistant bottle. The pressure-resistant bottle was connected to a high-pressure polymerization pipeline, and ethylene was introduced. Then, a complex dissolved in dichloromethane (1 μmol, 2 mL) was injected through a syringe. The ethylene pressure was controlled at 8 atm, the reaction temperature was controlled, and the reaction time was controlled at 10 minutes. After the reaction was completed, a 5% ethanol-hydrochloric acid solution was added to precipitate a solid. The solid was washed three times with pure ethanol and dried in a vacuum oven for 24 hours to constant weight to obtain polyethylene.

[0042] Application Example 2 Applications of catalytic copolymerization of ethylene and methyl acrylate Under anhydrous and oxygen-free conditions, a magnetic stir bar, 20 mL of n-heptane, and the co-catalyst Et2AlCl were added to a 350 mL pressure-resistant bottle. Methyl acrylate (Macrylate concentration: 0.5 mol / L) was then added. The pressure-resistant bottle was connected to a high-pressure polymerization pipeline, and ethylene was introduced. Then, the complex dissolved in dichloromethane (10 μmol, 2 mL) was injected through a syringe. The ethylene pressure was controlled at 1 atm, the reaction temperature was controlled, and the reaction time was controlled at 2 hours. After the reaction was completed, a 5% ethanol-hydrochloric acid solution was added to precipitate a solid. The solid was washed three times with pure ethanol and dried in a vacuum oven for 24 hours to constant weight to obtain the copolymer.

[0043] Table 1 below shows the experimental conditions for ethylene polymerization provided by this invention; catalyst (Cat.), temperature (T), yield (Yield), catalytic activity (Act.), polymer molecular weight (…). M n Polymerization results data such as polymer molecular weight distribution (PDI) and degree of branching (B).

[0044] Table 2 below shows the experimental conditions for the copolymerization of ethylene and methyl acrylate provided by this invention; catalyst (Cat.), temperature (T), methyl acrylate concentration (M), yield (Yield), catalytic activity (Act.), polymer molecular weight (M). M n Polymerization results data such as polymer molecular weight distribution (PDI) and degree of branching (B).

[0045] Table 1 Ethylene Polymerization a .

[0046] a Polymerization conditions: catalyst 1 μmol, dichloromethane = 2 mL, [Al] / [Ni] = 500, n-heptane = 20 mL, ethylene pressure 8 atm, time = 10 minutes; bThe unit of active Act is 10. 6 g mol -1 h -1 ; c polymer molecular weight M n The molecular weight distribution of PDI was determined by gel permeation chromatography (GPC) at 150 °C in trichlorobenzene and polystyrene standards; d Branching degree refers to the number of branches per 1000 carbon atoms, determined by... 1 Determined by H NMR nuclear magnetic resonance method; e Melting point T m Measured by differential scanning calorimetry (DSC).

[0047] Table 2. Copolymerization of ethylene and methyl acrylate a .

[0048] a Polymerization conditions: catalyst 10 μmol, dichloromethane = 2 mL, [Al] / [Ni] = 500, n-heptane = 20 mL, methyl acrylate = 0.5 mol / L, time = 2 hours; b The unit of active Act is 10. 4 g mol -1 h -1 ; c polymer molecular weight M n The molecular weight distribution of PDI was determined by gel permeation chromatography (GPC) at 150 °C in trichlorobenzene and polystyrene standards; d Polar monomer insertion ratio X m Depend on 1 Measured by H NMR nuclear magnetic resonance method; e Melting point T m Measured by differential scanning calorimetry (DSC).

[0049] The foregoing has provided a detailed description of the preparation method of the compound, complex catalyst, catalyst composition, and olefin polymer provided by the present invention. Specific examples have been used to illustrate the principles and embodiments of the invention, but the invention is not limited to the specific embodiments described herein. Those skilled in the art will understand that other modifications and variations can be made without departing from the scope of the invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

Claims

1. A catalyst containing a large volume of diimine nickel, characterized in that... The catalyst has a large-volume acenaphthoquinone framework. α - Diimine nickel complex, the structure of which is shown in formula (I): In this context, R1 is ethoxy, hexoxy, or 2-ethylhexoxy; R2 is tert-butyl; and R3 is methoxy.

2. A method for preparing a large-volume nickel diimine catalyst as described in claim 1, characterized in that: The preparation steps of the coordination compound are as follows: Step (1) Synthesis of compound (II): Under a nitrogen atmosphere, 4-bromophenol and triphenylphosphine were added to a solvent and placed in a low-temperature stirrer. 1.2 equivalents of the corresponding alcohol and diisopropyl azodicarbonate were added and stirred for 5-25 min. Then, the mixture was stirred overnight at room temperature. The solvent was evaporated, petroleum ether was added to precipitate the solid, the solid was filtered off, the filtrate was evaporated, and the product, compound (II), was obtained by column chromatography. The reaction formula is as follows: R1 is ethoxy, hexoxy, or 2-ethylhexoxy; Step (2) Synthesis of compound (III): Under a nitrogen atmosphere, dissolve compound (II) in a solvent and place it in a low-temperature stirrer. Add n-butyllithium and react for 1-2 h. Then add benzaldehyde with the para-substituent and react for 1-2 h. Stir overnight at room temperature, evaporate the solvent, extract three times with CH2Cl2, and dry with anhydrous magnesium sulfate. Filter off the magnesium sulfate, evaporate the filtrate to dryness, and obtain the product (compound (III)) by column chromatography. The reaction formula is as follows: R1 is ethoxy, hexoxy, or 2-ethylhexoxy; R2 is tert-butyl. Step (3) Synthesis of compound (IV): Take 2.5 equivalents of formula (III) and aniline with the corresponding substituents, heat to 120℃, slowly add concentrated hydrochloric acid solution of zinc chloride, then raise the temperature to 160℃ and react for 1~2 h. Cool the reactants to room temperature, extract three times with CH2Cl2, and dry with anhydrous magnesium sulfate. Filter off the magnesium sulfate, evaporate the filtrate to dryness, and separate the product, i.e., compound (IV), by column chromatography. The reaction formula is as follows: In this context, R1 is ethoxy, hexoxy, or 2-ethylhexoxy; R2 is tert-butyl; and R3 is methoxy. Step (4) Synthesis of compound (V): Dissolve acenaphthene and zinc chloride in a solvent, stir at 140°C and add aniline obtained from formula (IV). After reacting for 3-5 h, cool to room temperature, add methanol to precipitate the solid, filter, wash with methanol, dissolve the solid in a solvent, add potassium oxalate, stir overnight at room temperature, extract three times with CH2Cl2, dry with anhydrous magnesium sulfate, filter off the magnesium sulfate, concentrate the filtrate, recrystallize with methanol to obtain the product, compound (V), with the following reaction formula: In this context, R1 is ethoxy, hexoxy, or 2-ethylhexoxy; R2 is tert-butyl; and R3 is methoxy. Step (5) Synthesis of Formula (I) Complex: Under a nitrogen atmosphere, the compound synthesized in step (4) is reacted with (DME)NiBr2 in a solvent at a 1:1 equivalent ratio for 6-12 h. After filtration, washing, and drying, the acenaphthoquinone skeleton is synthesized. α -Diimine nickel complex (VI), reaction formula is as follows: In this context, R1 is ethoxy, hexoxy, or 2-ethylhexoxy; R2 is tert-butyl; and R3 is methoxy.

3. The preparation method of the large-volume diimine nickel catalyst as described in claim 2, characterized in that: The solvents mentioned in steps (1), (2), (4), and (5) are one or a mixture of several of tetrahydrofuran, acetic acid, dichloromethane, petroleum ether, and ethyl acetate.

4. An application of the nickel catalyst containing a large volume diimine as described in claim 1, characterized in that: The complex and co-catalyst form a catalytic system used in the catalytic polymerization of ethylene to prepare high molecular weight polyethylene or in the copolymerization of ethylene with polar monomers, as detailed below: In the catalytic preparation of high molecular weight polyethylene from ethylene: under anhydrous and oxygen-free conditions, solvent and co-catalyst are added to a 350 mL pressure-resistant bottle. The pressure-resistant bottle is connected to a high-pressure polymerization pipeline, and ethylene is introduced. Then, the complex dissolved in the solvent is injected through a syringe. The ethylene pressure is controlled at 1~20 atm, the reaction temperature is 0~120 ℃, and the reaction time is 5~30 min. After the reaction is completed, an alcohol solution containing hydrochloric acid is added to quench the reaction. After filtration and drying, polyethylene is obtained. Used in the copolymerization of ethylene and polar monomers: Under anhydrous and oxygen-free conditions, solvent and co-catalyst are added to a 350 mL pressure-resistant bottle. The pressure-resistant bottle is connected to a high-pressure polymerization pipeline and ethylene is introduced. Then, the complex dissolved in the solvent is injected through a syringe, followed by the injection of the polar monomer. The ethylene pressure is controlled at 1~5 atm, the reaction temperature at 0~100 ℃, and the reaction time at 1~12 h. After the reaction is completed, an alcohol solution containing hydrochloric acid is added to quench the reaction. The mixture is then filtered, dried, and the copolymer is obtained. The co-catalyst is MAO, MMAO, or AlEt2Cl.

5. The application of the bulky nickel diimine catalyst as described in claim 4, characterized in that: The solvent is toluene, n-heptane, or dichloromethane; the alcohol solution containing hydrochloric acid is a methanol solution with a hydrochloric acid concentration of 5 wt% or higher, or an ethanol solution with a hydrochloric acid concentration of 5 wt% or higher.

6. The application of the nickel catalyst containing large-volume diimine as described in claim 4, characterized in that: The polar monomer is one or more of the following: methyl methacrylate, methyl acrylate, methyl 10-undecenoate, 10-undecen-1-ol, allyltrimethoxysilane, allyl chloride, 6-chloro-1-hexene, styrene, allylbenzene, ethyl allyl ether, and vinyl ethyl ether.

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