An asymmetrically modified camphor skeleton ni complex and a synthesis method and application thereof

Abstract

The application discloses an asymmetrically modified camphor skeleton Ni complex and a synthesis method and application thereof. The complex has a structure as shown in the formula I. The complex has good catalytic activity and thermal stability in catalyzing an olefin polymerization reaction, and the polymer obtained by catalysis has high molecular weight and polyethylene branching degree, and the obtained polyethylene material has good elastic performance.

Description

Technical Field

[0001] This invention belongs to the field of olefin polymerization catalysts, specifically relating to an asymmetric modified camphene-based Ni complex, its synthesis method, and its application. Background Technology

[0002] Polyolefin elastomers prepared by copolymerization of ethylene and α-olefins are currently a research hotspot in polyolefin materials. These materials possess advantages such as wide availability of raw materials, low cost, simple synthesis processes, strong chemical resistance, and excellent mechanical properties, making them widely used in high-value-added fields such as plastic compatibilizers, shoe sole substrates, photovoltaic encapsulation films, microelectronic packaging materials, and elastic fibers. However, given the insufficient supply of α-olefin monomers in my country, the development of novel catalysts that can overcome the limitations of traditional copolymerization systems is particularly urgent. Brookhart-type α-diimine nickel(II) complex catalysts can directly prepare polyethylene elastomers through the polymerization of ethylene alone, representing a catalytic system with significant industrialization potential. This catalyst follows a "chain-walking" mechanism during ethylene polymerization; by controlling the electronic effects and steric hindrance of the ligands, it can not only effectively regulate catalytic activity but also precisely control the branched structure of the resulting polyethylene, achieving "tailoring" of the polymer's microstructure. Based on this, polyethylene elastomers with narrow molecular weight distribution and controllable structure can be obtained, covering a variety of products from low molecular weight highly branched (suitable for pour point depressants), medium molecular weight medium branched (suitable for membrane materials) to high molecular weight highly branched (suitable for high-strength resins).

[0003] Highly active and controllable olefin polymerization technology has significant advantages in polymer microstructure regulation, enabling the synthesis of structurally precise polyolefins. However, achieving both high activity and controllability in olefin polymerization remains a serious challenge, especially at higher temperatures, due to chain termination caused by β-H elimination and chain transfer reactions caused by co-catalysts or monomers. Short catalyst active site lifetimes and rapid deactivation rates also restrict the development of this technology. Currently reported highly active controllable polymerizations mostly require low-temperature, short-reaction-time conditions. Although α-diimine nickel catalysts have made some progress in the controllable polymerization of α-olefins such as propylene, 1-hexene, and 4-methyl-1-pentene, examples of highly active controllable polymerization at high temperatures (above room temperature) are still extremely limited. Of particular note is the cycloalkyl α-diimine nickel catalyst developed by Guan's research group, which achieved the living / controllable polymerization of propylene and 1-hexene at 50°C, providing an important reference for controllable polymerization under high-temperature conditions.

[0004] In summary, developing highly stable post-transition metal catalysts, combined with chain-walking technology and active controllable polymerization strategies, to prepare polyolefin materials with novel microstructures has become an important direction for development in this field.

[0005] Although α-diimine catalysts exhibit high catalytic activity, their poor thermal stability is a major drawback. Palladium and nickel-based catalytic systems tend to decompose rapidly at temperatures exceeding 60°C. Increased temperature leads to intensified aniline fragment rotation and promotes CH activation and chain transfer processes. To improve the thermal stability of these catalytic systems, researchers have primarily focused on N-aryl fragment substitution and ligand skeleton modification. Currently, acenaphthene and ArN=C(R)-C(R)=NAr (R = Me, H) skeletons are the most widely used α-diimine skeletons. Increasing the size of the substituents helps improve stability; therefore, replacing hydrogen substituents with methyl groups can enhance stability. To investigate the influence of skeleton structure on the activity of catalysts in ethylene polymerization, the camphene (camphyl) skeleton, as a bulky and thermally stable structure, has attracted widespread attention. Catalysts containing the camphene skeleton can be stable up to 80°C in polymerization reactions; this stability stems from its rigid and bulky bicyclic skeleton structure. Furthermore, the presence of numerous aliphatic chains in the camphene group can significantly improve the poor solubility of nickel-based catalysts.

[0006] Therefore, we have invented a novel asymmetric modified camphene-based framework Ni complex, its synthesis method and application, which not only ensures the polymerization stability of the catalyst under high temperature conditions, but also solves the problem of poor solubility of traditional nickel-based catalysts. Summary of the Invention

[0007] To address the numerous problems existing in the polymerization of ethylene using nickel-based catalysts, the present invention aims to provide an asymmetrically modified camphene-based nickel complex. This complex exhibits significantly superior catalytic performance compared to symmetrically modified camphene-based nickel complexes. Through the combined effects of ligand steric hindrance and electronic effects, it demonstrates better catalytic activity and excellent thermal stability in the ethylene polymerization reaction. The resulting polymer has a higher molecular weight and degree of branching in polyethylene, and the obtained polyethylene material exhibits excellent elastic properties.

[0008] The technical solution of the present invention is as follows: The complex shown in Formula I,

[0009] Formula I Among them, R 1 Ra is unsubstituted, or optionally substituted by at least one Rs; said Rs are selected from C 1-6 Alkyl, F, Cl, Br, I, NO2 or C 1-6 Alkoxy; R 2 R 3 R 4 They are either the same or different, and are independently selected from H, F, Cl, Br, I, and C.1-6 Alkyl, C 3-6 cycloalkyl, halogenated C 1-6 Alkyl groups, halogenated C 3-6 Cycloalkyl, at least one Rb-substituted C 1-6 Alkyl group, or at least one halogenated Rc-substituted C 1-6 alkyl; Ra, Rb, and Rc may be the same or different, and are independently selected from C. 6-14 aryl or C 5-14 Mixed aromatics; X is selected from F, Cl, Br, I, C 1-6 Alkyl group, where the two Xs are the same or different.

[0010] According to embodiments of the present invention, Ra, Rb, and Rc may be the same or different, and are independently selected from biphenyl, phenyl, naphthyl, or anthracene.

[0011] According to an embodiment of the present invention, R 1 The following groups are either unsubstituted or optionally substituted with at least one Rs: biphenyl, phenyl, naphthyl, or anthracene.

[0012] According to an embodiment of the present invention, Rs is selected from C 1-3 Alkyl, F, Cl, Br, I, NO2 or C 1-3 Alkyl group.

[0013] According to an embodiment of the present invention, R 2 R 3 R 4 They are either the same or different, and are independently selected from H, F, Cl, Br, I, and C. 1-3 Alkyl, C 3-6 cycloalkyl, halogenated C 1-6 Alkyl groups, halogenated C 3-6 Cycloalkyl, phenyl-substituted methyl, diphenyl-substituted methyl, monohalophenyl-substituted methyl, or methyl substituted by two halophenyl groups.

[0014] According to an embodiment of the present invention, X is selected from F, Cl, Br or I, and the two Xs may be the same or different.

[0015] According to an embodiment of the present invention, R 1 for , , or .

[0016] According to an embodiment of the present invention, R 2 R 3 R 4They may be the same or different, and are independently selected from H, F, Cl, Br, I, methyl, ethyl, and isopropyl. In some embodiments, R 2 For H. In some implementations, R 3 Selected from H, methyl, ethyl, isopropyl, Cl, or Br. In some embodiments, R 4 Selected from H, methyl, ethyl, isopropyl, Cl, or Br. In some embodiments, R 2 and R 3 The same. In some implementations, R 4 and R 3 same.

[0017] According to an embodiment of the present invention, the two X's are identical and are selected from Cl or Br.

[0018] According to an embodiment of the present invention, the complex is selected from any one of Ni1 to Ni14: Complex Ni1: The R 1 = R 2 = R 3 = H, R 4 = Me, X is selected from Br; Complex Ni2: The R 1 = R 2 = H, R 3 = R 4 = Me, X is selected from Br; Complex Ni3: The R 1 = R 2 = H, R 3 = R 4 = i -Pr, X is selected from Br; Complex Ni4: The R 1 = R 2 = H, R 3 = R 4 = Et, X is selected from Br; Complex Ni5: The R 1 = R 2 = H, R 3 = R 4 = Cl, X is selected from Br; Complex Ni6: The R 1 = R 2 = H, R 3 = R 4= Br, X is selected from Br; Complex Ni7: The R 1 = R 2 = R 3 = H, R 4 = Me, X is selected from Br; Complex Ni8: The R 1 = R 2 = H, R 3 = R 4 = Me, X is selected from Br; Complex Ni9: The R 1 = R 2 = H, R 3 = R 4 = i -Pr, X is selected from Br; Complex Ni10: The R 1 = R 2 = H, R 3 = R 4 = Et, X is selected from Br; Complex Ni11: The R 1 = R 2 = H, R 3 = R 4 = Cl, X is selected from Br; Complex Ni12: The R 1 = R 2 = H, R 3 = R 4 = Br, X is selected from Br; Complex Ni13: The R 1 = R 2 = R 3 = H, R 4 = Me, X is selected from Br; Complex Ni14: The R 1 = R 2 = R 3 = H, R 4 = Me, X is selected from Br.

[0019] The present invention also provides a method for preparing the complex represented by Formula I, comprising the following steps; Compounds IIa, IIb, and IIc react with compound NiX2 to obtain the complex shown in Formula I;

[0020] Among them, R 1 R 2 R 3 R 4 X has the definition described above.

[0021] According to an embodiment of the present invention, R 1 R 3 R 4 If the definitions are the same or different, that is, when the complex shown in Formula I has an asymmetric structure, compound IIa is first subjected to formic acid reflux reaction with any one of IIb and IIc, the resulting product is then subjected to toluene reflux reaction with the remaining one of compounds IIb and IIc, and finally reacted with compound NiX2.

[0022] According to some embodiments of the present invention, the preparation method includes the following steps: Compound IIa and compound IIb were subjected to formic acid reflux, and the reaction solution was dried by rotary evaporation and recrystallized to obtain product I. Product I, compound IIc, and alkyl aluminum (e.g., trimethylaluminum) are refluxed in toluene, then cooled to room temperature. Product II is dissolved in toluene until the system changes color. The reaction is then heated again, cooled to 0±2℃ (e.g., 0℃) in an ice-water bath, and the reaction is terminated by adding alkali. The organic phase is extracted and collected, washed, evaporated to dryness, and precipitated to obtain the ligand. The ligand reacts with NiX2 at room temperature to obtain the complex shown in Formula I.

[0023] According to some embodiments of the present invention, the preparation method includes the following steps: Compound IIa and compound IIc were subjected to formic acid reflux, and the reaction solution was dried by rotary evaporation and recrystallized to obtain product one. Product I, compound IIb, and alkyl aluminum (e.g., trimethylaluminum) were refluxed in toluene, then cooled to room temperature. Product II was dissolved in toluene until the system changed color. The reaction was then heated again, cooled to 0°C in an ice-water bath, and the reaction was terminated by adding alkali. The organic phase was extracted and collected, washed, evaporated to dryness, and precipitated to obtain the ligand. The ligand reacts with NiX2 at room temperature to obtain the complex shown in Formula I.

[0024] According to an embodiment of the present invention, the molar ratio of compound IIa, compound IIb and compound IIc is (5~15):(5~15):1, for example (7~12):(7~12):1, and exemplary ratios are 8:8:1, 9:9:1, 10:10:1, 11:11:1.

[0025] According to an embodiment of the present invention, the molar ratio of compound IIa and compound IIb is 1:1.

[0026] According to an embodiment of the present invention, the molar ratio of the ligand to NiX2 is 1:(0.8~1.2), for example 1:1 or 1:1.1.

[0027] According to an embodiment of the present invention, the temperature of the heating and reflux reaction is 100~140℃ (e.g. 110~130℃), and the time is 1~4h (e.g. 2~3h).

[0028] According to an embodiment of the present invention, the temperature of the reheating reaction is 100~140℃ (e.g. 110~130℃), and the time is 3~10h (e.g. 4~7h).

[0029] According to an exemplary embodiment of the present invention, compound IIb is selected from 2-aminobiphenyl, 1-aminonaphthalene, 2-aminonaphthalene or 9-aminoanthracene.

[0030] According to an exemplary embodiment of the present invention, the compound IIc is selected from 2-methylaniline, 2,6-dimethylaniline, 2,6-diisopropylaniline, 2,6-diethylaniline, 2,6-dichloroaniline or 2,6-dibromoaniline.

[0031] According to an exemplary embodiment of the present invention, the compound NiX2 is selected from NiCl2, NiBr2, (DME)NiBr2 or (DME)NiCl2.

[0032] The present invention also provides a catalyst for olefin polymerization, comprising the complex shown in Formula I above.

[0033] The present invention also provides a catalyst composition comprising the complex shown in Formula I above.

[0034] According to an embodiment of the present invention, the catalyst composition is used to catalyze an olefin polymerization reaction, wherein the olefin is preferably ethylene.

[0035] According to an embodiment of the present invention, the polymerization is a polymerization of the same olefin monomer or a copolymerization reaction of two or more olefin monomers.

[0036] According to an embodiment of the present invention, the catalyst composition further includes an auxiliary agent.

[0037] According to an embodiment of the present invention, the auxiliary agent is one or more of aluminoxane, alkylaluminum or alkylaluminum chloride, for example Et2AlCl.

[0038] According to an embodiment of the present invention, the molar ratio of metal Al in the additive to metal Ni in the complex shown in Formula I is (100~2000):1, for example (200~1800):1, (300~1500):1 or (500~1000):1, with an exemplary ratio of 1000:1.

[0039] According to an embodiment of the present invention, the auxiliary agent is at least one of sesquiethylaluminum chloride (EASC) and Et2AlCl.

[0040] According to an embodiment of the present invention, when the additive is sesquiethylaluminum chloride (EASC), the molar ratio of metal Al in the additive to metal Ni in the complex shown in Formula I is (100~2000):1, for example (100~1500):1.

[0041] According to an embodiment of the present invention, when the additive is Et2AlCl, the molar ratio of metallic Al in the additive to metallic Ni in the complex shown in Formula I is (100~2000):1, for example (100~1200):1, and exemplarily 1000:1.

[0042] The present invention also provides a method for catalyzing olefin polymerization, comprising polymerizing olefins in the presence of a complex or catalyst composition as shown in Formula I as described above.

[0043] According to an embodiment of the present invention, the olefin is preferably ethylene.

[0044] According to an embodiment of the present invention, the polymerization is a polymerization of the same olefin monomer or a copolymerization reaction of two or more olefin monomers.

[0045] According to an embodiment of the present invention, the polymerization reaction temperature is 30~80°C, for example 30°C, 40°C, 50°C, 60°C, 70°C or 80°C.

[0046] Beneficial effects This invention provides a novel asymmetric modified camphene-based Ni complex for use as a catalyst in the polymerization of olefins (e.g., ethylene). The stability of this complex stems from its robust and bulky bicyclic framework. Furthermore, the presence of numerous aliphatic chains in the camphene group significantly improves the poor solubility of nickel-based catalysts, ensuring polymerization stability at high temperatures while resolving the poor solubility issue of traditional nickel-based catalysts. This high thermal stability gives the catalyst promising prospects for industrial applications. Moreover, polyethylene samples catalyzed by this complex exhibit improved branching degree and molecular weight, along with good elasticity and toughness.

[0047] The post-processing method provided by this invention uses recrystallization, avoiding the need for cumbersome chromatography column separation to synthesize the target catalyst. The method has advantages such as mild reaction conditions, simple operation, and easy post-processing, providing a new approach for preparing asymmetric modified camphene-based Ni complexes.

[0048] Terminology Definitions and Explanations Unless otherwise stated, the definitions of terms recorded in this application specification and claims, including definitions as examples, exemplary definitions, preferred definitions, and definitions of specific compounds in the embodiments, can be arbitrarily combined and combined with each other. Such combinations and combinations shall fall within the scope of this application specification.

[0049] Unless otherwise stated, the numerical ranges described in this specification and claims are equivalent to describing at least each specific integer value therein. For example, the numerical range "1-6" is equivalent to describing each integer value in the numerical range "1-6", namely 1, 2, 3, 4, 5, or 6.

[0050] The term "at least one" refers to one, two, or three or more.

[0051] The term "halogen" includes F, Cl, Br, and I.

[0052] Term "C" 1-6 "Alkyl" should be understood to refer to straight-chain and branched alkyl groups having 1 to 6 carbon atoms, specifically straight-chain and branched alkyl groups having 1, 2, 3, 4, 5, or 6 carbon atoms. Examples include methyl, ethyl, propyl, butyl, pentyl, hexyl, isopropyl, isobutyl, sec-butyl, tert-butyl, isopentyl, 2-methylbutyl, 1-methylbutyl, 1-ethylpropyl, 1,2-dimethylpropyl, neopentyl, 1,1-dimethylpropyl, 4-methylpentyl, 3-methylpentyl, 2-methylpentyl, 1-methylpentyl, 2-ethylbutyl, 1-ethylbutyl, 3,3-dimethylbutyl, 2,2-dimethylbutyl, 1,1-dimethylbutyl, 2,3-dimethylbutyl, 1,3-dimethylbutyl, or 1,2-dimethylbutyl, or their isomers.

[0053] Term "C" 1-6 "Alkoxy" should be understood as a group formed by an alkyl group (straight-chain or branched-chain) with 1 to 6 carbon atoms bonded to an oxygen atom, representing straight-chain and branched alkoxy groups with 1, 2, 3, 4, 5, or 6 carbon atoms. Examples include methoxy, ethoxy, n-propoxy, n-butoxy, n-pentoxy, n-hexoxy, isopropoxy, isobutoxy, sec-butoxy, tert-butoxy, isopentoxy, neopentoxy, tert-pentoxy, 2-hexoxy, 3-hexoxy, etc.

[0054] Term "C" 3-6 "Cycloalkyl" should be understood as referring to a cyclic alkyl group having 3 to 6 carbon atoms, specifically a cyclic alkyl group having 3, 4, 5, or 6 carbon atoms. Examples include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, methylcyclopropyl, methylcyclobutyl, dimethylcyclopropyl, methylcyclopentyl, ethylcyclobutyl, or dimethylcyclobutyl.

[0055] Term "C" 6-14 "Aryl" should be understood as an aromatic ring group having 6 to 14 carbon atoms, specifically an aromatic ring group having 6, 10, or 14 carbon atoms. Examples include phenyl, naphthyl (1-naphthyl, 2-naphthyl), anthraceneyl (1-anthrayl, 2-anthrayl, 9-anthrayl), and phenanthryl (1-phenanthryl, 2-phenanthryl, 3-phenanthryl, 4-phenanthryl, 9-phenanthryl).

[0056] Term "C" 5-14 "Heteroaryl" refers to an aromatic ring group containing 5 to 14 ring atoms, at least one of which is a heteroatom (such as N, O, S, etc.). Examples include furanyl, thiophene, pyrrole, pyridyl, indolyl, benzofuranyl, quinolinyl, etc. Attached Figure Description

[0057] Figure 1 The graph shows a comparison of the solubility of complex Ni1 with traditional acenaphthene-based Ni complexes and symmetrically modified camphene-based Ni complexes (prepared as 1 mol / L n-hexane solutions).

[0058] Figure 2 This is a schematic diagram of the 1H NMR spectrum of ligand L1 prepared in Example 1.

[0059] Figure 3 This is a schematic diagram of the infrared spectrum of the catalyst Ni1 prepared in Example 1.

[0060] Figure 4 This is a schematic diagram of the 1H NMR spectrum of ligand L2 prepared in Example 2.

[0061] Figure 5 This is a schematic diagram of the infrared spectrum of the Ni2 catalyst prepared in Example 2.

[0062] Figure 6 This is a schematic diagram of the 1H NMR spectrum of ligand L3 prepared in Example 3.

[0063] Figure 7 This is a schematic diagram of the infrared spectrum of the Ni3 catalyst prepared in Example 3.

[0064] Figure 8 The image shows the carbon NMR spectrum of the polymer obtained by polymerization of Ni3 catalyst in Example 3 at 100 °C. Detailed Implementation

[0065] The technical solution of the present invention will be further described in detail below with reference to specific embodiments. It should be understood that the following embodiments are merely illustrative and explanatory of the present invention, and should not be construed as limiting the scope of protection of the present invention. All technologies implemented based on the above content of the present invention are covered within the scope of protection intended by the present invention.

[0066] Unless otherwise stated, the raw materials and reagents used in the following examples are commercially available products or can be prepared by known methods.

[0067] The diethylaluminum chloride (Et2AlCl) used in the following examples and comparative examples was purchased from Anhui Zesheng Technology Co., Ltd.

[0068] This application Figure 1 The structure of the acenaphthene-based framework Ni complex in Example 15:

[0069] This application Figure 1 The structure of the Ni-symmetric modified camphor framework complex in Example 15:

[0070] The Ni1 to Ni14 were prepared in Examples 1 to 14 below, and their structures are as follows: .

[0071] Example 1 Preparation of (1S, 2Z, 3E, 4S)- N 2 -([1,1'-biphenyl]-2-yl)-1,7,7-trimethyl- N 3 -(o-tolyl)bicyclo[2.2.1]heptane-2,3-diimine·nickel(II) bromide complex, Ni1 In a 100 ml side-necked flask, 6.11 g of 2-aminobiphenyl (36 mmol) and 5.98 g of camphorquinone (36 mmol) were added, followed by 50 ml of methanol. A catalytic amount of formic acid was then added dropwise, and the mixture was refluxed overnight. After the solvent was evaporated by rotary evaporation, the solution was recrystallized from methanol to give an orange-yellow crystalline product with a yield of 58.3%. In another side-necked flask, 10 mL of toluene and 0.5 mL of 2-methylaniline (4.4 mmol) were added sequentially. Then, 2.2 mL of trimethylaluminum (2.0 M in toluene, 4.4 mmol) was slowly added using a syringe, and the reaction temperature was raised to 120 °C. o The reaction proceeds at step C, releasing methane gas. After 2 hours of reaction, the reaction temperature is lowered to room temperature. 1.27 g (4 mmol) of the single-sided product is dissolved in 5 ml of toluene and slowly added dropwise to the reaction system. At this point, the reaction system changes from colorless to dark green and releases a large amount of heat. At 120°C... o The reaction continued at C for 6 hours, followed by cooling to 0°C in an ice-water bath. o C. The reaction was terminated with 5% sodium hydroxide solution. The organic phase was extracted with ethyl acetate, washed with saturated NaCl aqueous solution, and dried over anhydrous Na₂SO₄. The solvent was evaporated under reduced pressure to give a dark red oily substance, which precipitated in methanol to give a bright yellow solid powder (i.e., ligand L1, 1H NMR spectrum shown). Figure 2 ), with a yield of 65.1%.

[0072] Under nitrogen protection, ligand L1 407 mg (1.0 mmol) and (DME)NiBr2 339 mg (1.1 mmol) were added to a 100 mL side-necked flask, with 20 mL of dichloromethane as the solvent. The solution turned dark red, and the reaction was stirred at room temperature for 12 hours. Then, the solvent was evaporated under reduced pressure to about 5 mL at room temperature, and 20 mL of n-hexane was added, at which point a large amount of precipitate was formed. The precipitate was filtered through a filter ball, washed with 3 × 10 mL of n-hexane, and then dried under vacuum to obtain a brownish-yellow solid powder, namely the complex Ni1, with a yield of 85.4%.

[0073] The structure of the complex Ni1 is characterized as follows: MS (ESI) + , m / z): 545.2 [M-Br] + , 465.3 [M-2Br] + Elem Anal calcd for C 29 H 30 Br2N2Ni: C, 55.72; H, 4.84; N, 4.48. Found: C, 55.93; H, 4.61; N, 4.27. ATR (cm -1 ): 1685.34, 1648.05 (w,v C=N ). Figure 3 The infrared spectrum of the complex Ni1.

[0074] Figure 1 The results showed that the complex Ni1 formed a clear solution compared to traditional acenaphthoquinone skeleton Ni complexes and symmetrically modified camphene skeleton Ni complexes.

[0075] Example 2 Preparation of (1S, 2Z, 3E, 4S)- N 2 -([1,1'-biphenyl]-2-yl)- N 3 -(2,6-dimethylphenyl)-1,7,7-trimethylbicyclo[2.2.1]heptane-2,3-diimine·nickel(II) bromide complex, Ni2 Similar to Example 1, 2-methylaniline was replaced with 2,6-dimethylaniline, and the amounts of other substances were adjusted according to the corresponding molar ratios, with similar procedures. A red powder Ni2 (81.8%) was obtained.

[0076] Figure 4 This is the 1H NMR spectrum of ligand L2 in this embodiment.

[0077] The structure of the complex Ni2 is characterized as follows: MS (ESI) + , m / z): 559.2 [M-Br] + , 479.1 [M-2Br] + Elem Anal calcd for C 30 H 32 Br2N2Ni : C, 56.38; H, 5.05; N, 4.38. Found: C, 56.55; H, 4.87; N, 4.16. ATR (cm -1 ): 1644.43, 1601.02 (w, v C=N ). Figure 5 The infrared spectrum of the complex Ni2.

[0078] Example 3 Preparation of (1S, 2Z, 3E, 4S)- N 2 -([1,1'-biphenyl]-2-yl)- N 3 -(2,6-diisopropylphenyl)-1,7,7-trimethylbicyclo[2.2.1]heptane-2,3-diimine·nickel(II) bromide complex, Ni3 Figure 6 This is the 1H NMR spectrum of ligand L3 in this embodiment.

[0079] The process for complex Ni3 was similar to that in Example 1, except that 2-methylaniline was replaced with 2,6-diisopropylaniline, and the amounts of other substances were adjusted according to the corresponding molar ratios. The operation was similar. Ni3 was obtained as a reddish-brown solid with a yield of 85.7%.

[0080] The structure is characterized as follows: MS (ESI) + , m / z): 615.4 [M-Br] + 535.0 [M-2Br] + Elem.Anal. calcd for C 34 H 40 Br2N2Ni : C, 58.74; H, 5.80; N, 4.03. Found: C, 58.91; H,5.66; N, 4.11. ATR (cm -1 ): 1675.74, 1639.79 (w, v C=N ). Figure 7 The infrared spectrum of the complex Ni3 is shown below. Figure 8 The image shows the carbon NMR spectrum of the polymer obtained by polymerizing the Ni3 complex at 100 °C.

[0081] Example 4 Preparation of (1S, 2Z, 3E, 4S)- N 2 -([1,1'-biphenyl]-2-yl)- N 3 -(2,6-diethylphenyl)-1,7,7-trimethylbicyclo[2.2.1]heptane-2,3-diimine·nickel(II) bromide, Ni4 Similar to Example 1, 2-methylaniline was replaced with 2,6-diethylaniline, and the amounts of other substances were adjusted according to the corresponding molar ratios, with similar procedures. A red powder, Ni4 (87.3%), was obtained.

[0082] The structure is characterized as follows: MS (ESI) + , m / z): 587.3 [M-Br] + 507.4 [M-2Br] + Elem.Anal. calcd for C 32 H 36 Br2N2Ni : C, 57.61; H, 5.44; N, 4.20. Found: C, 57.72; H,5.46; N, 4.17. ATR (cm -1): 1681.43, 1626.72 (w, v C=N ).

[0083] Example 5 Preparation of (1S, 2Z, 3E, 4S)- N 2 -([1,1'-biphenyl]-2-yl)- N 3 -(2,6-dichlorophenyl)-1,7,7-trimethylbicyclo[2.2.1]heptane-2,3-diimine·nickel(II) bromide, Ni5 Similar to Example 1, 2-methylaniline was replaced with 2,6-dichloroaniline, and the amounts of other substances were adjusted according to the corresponding molar ratios, with similar procedures. A red powder, Ni5 (66.6%), was obtained.

[0084] The structure is characterized as follows: MS (ESI) + , m / z): 600.0 [M-Br] + , 520.1 [M-2Br] + Elem.Anal. calcd for C 28 H 26 Br2N2Ni: C, 49.46; H, 3.85; N, 4.12. Found: C, 49.49; H, 3.80; N, 4.07. ATR (cm -1 ): 1676.03, 1645.86 (w, v C=N ).

[0085] Example 6 Preparation of (1S, 2Z, 3E, 4S)- N 2 -([1,1'-biphenyl]-2-yl)- N 3 -(2,6-dibromophenyl)-1,7,7-trimethylbicyclo[2.2.1]heptane-2,3-diimine·nickel(II) bromide, Ni6 Similar to Example 1, 2-methylaniline was replaced with 2,6-dibromoaniline, and the amounts of other substances were adjusted according to the corresponding molar ratios, with similar procedures. A brownish-yellow Ni6 powder (68.5%) was obtained.

[0086] The structure is characterized as follows: MS (ESI) + , m / z): 688.9 [M-Br] + , 609.0 [M-2Br] + Elem.Anal. calcd for C28 H 26 Br2N2Ni: C, 43.74; H, 3.41; N, 3.64. Found: C, 43.80; H, 3.45; N, 3.69. ATR (cm -1 ): 1650.33, 1623.29 (w, v C=N ).

[0087] Example 7 Preparation of (1S, 2Z, 3E, 4S)- N 3 -(o-methylphenyl)-1,7,7-trimethyl- N 2 -(naphthyl-1-yl)bicyclo[2.2.1]heptane-2,3-diimine·nickel(II) bromide, Ni7 Similar to Example 1, 2-aminobiphenyl was replaced with 1-aminonaphthalene, and the amounts of other substances were adjusted according to the corresponding molar ratios, with similar procedures. A brownish-red powder, Ni7 (73.5%), was obtained.

[0088] The structure is characterized as follows: MS (ESI) + , m / z): 519.1 [M-Br] + , 439.2 [M-2Br] + Elem.Anal. calcd for C 27 H 28 Br2N2Ni: C, 54.14; H, 4.71; N, 4.68. Found: C, 54.10; H, 4.78; N, 4.69. ATR (cm -1 ): 1692.13, 1624.44 (w, v C=N ).

[0089] Example 8 Preparation of (1S, 2Z, 3E, 4S)- N 3 -(2,6-dimethylphenyl)-1,7,7-trimethyl- N 2 -(naphthyl-1-yl)bicyclo[2.2.1]heptane-2,3-diimine·nickel(II) bromide, Ni8 Similar to Example 1, 2-aminobiphenyl was replaced with 1-aminonaphthalene and 2-methylaniline was replaced with 2,6-dimethylaniline. The amounts of other substances were adjusted according to the corresponding molar ratios, and the operation was similar. A brownish-red powder Ni8 (70.6%) was obtained.

[0090] The structure is characterized as follows: MS (ESI) + , m / z): 533.2 [M-Br] + , 453.3 [M-2Br] + Elem.Anal. calcd for C 28 H 30 Br2N2Ni: C, 54.86; H, 4.93; N, 4.57. Found: C, 54.82; H, 4.98; N, 4.59. ATR (cm -1 ): 1687.10, 1618.04 (w, v C=N ).

[0091] Example 9 Preparation of (1S, 2Z, 3E, 4S)- N 3 -(2,6-diisopropylphenyl)-1,7,7-trimethyl- N 2 -(naphthyl-1-yl)bicyclo[2.2.1]heptane-2,3-diimine·nickel(II) bromide, Ni9 Similar to Example 1, 2-aminobiphenyl was replaced with 1-aminonaphthalene and 2-methylaniline was replaced with 2,6-diisopropylaniline. The amounts of other substances were adjusted according to the corresponding molar ratios, and the operation was similar. A brownish-red powder Ni9 (81.2%) was obtained.

[0092] The structure is characterized as follows: MS (ESI) + , m / z): 589.3 [M-Br] + 509.4 [M-2Br] + Elem.Anal. calcd for C 32 H 38 Br2N2Ni: C, 57.44; H, 5.72; N, 4.19. Found: C, 57.48; H, 5.76; N, 4.15. ATR (cm -1 ): 1679.17, 1619.57 (w, v C=N ).

[0093] Example 10 Preparation of (1S, 2Z, 3E, 4S) - N 3 -(2,6-diethylphenyl)-1,7,7-trimethyl- N 2-(naphthyl-1-yl)bicyclo[2.2.1]heptane-2,3-diimine·nickel(II) bromide, Ni10 Similar to Example 1, 2-aminobiphenyl was replaced with 1-aminonaphthalene and 2-methylaniline was replaced with 2,6-diethylaniline. The amounts of other substances were adjusted according to the corresponding molar ratios, and the operation was similar. A red powder Ni10 (0.11 g, 74.4%) was obtained.

[0094] The structure is characterized as follows: MS (ESI) + , m / z): 561.2 [M-Br] + , 481.3 [M-2Br] + Elem.Anal. calcd for C 30 H 34 Br2N2Ni : C, 56.20; H, 5.35; N, 4.37. Found: C, 56.28; H,5.39; N, 4.35. ATR (cm -1 ): 1672.19, 1626.42 (w, v C=N ).

[0095] Example 11 Preparation of (1S, 2Z, 3E, 4S)- N 3 -(2,6-dichlorophenyl)-1,7,7-trimethyl- N 2 -(naphthyl-1-yl)bicyclo[2.2.1]heptane-2,3-diimine·nickel(II) bromide, Ni11 Similar to Example 1, 2-aminobiphenyl was replaced with 1-aminonaphthalene and 2-methylaniline was replaced with 2,6-dichloroaniline. The amounts of other substances were adjusted according to the corresponding molar ratios, and the operation was similar. A red powder Ni11 (68.4%) was obtained.

[0096] The structure is characterized as follows: MS (ESI) + , m / z): 574.0 [M-Br] + , 494.1 [M-2Br] + Elem.Anal. calcd for C 26 H 24 Br2N2Ni: C, 47.76; H, 3.70; N, 4.28. Found: C, 47.70; H, 3.76; N, 4.31. ATR (cm -1 ): 1671.63, 1629.03 (w, vC=N ).

[0097] Example 12 Preparation of (1S, 2Z, 3E, 4S)- N 3 -(2,6-dibromophenyl)-1,7,7-trimethyl- N 2 -(naphthyl-1-yl)bicyclo[2.2.1]heptane-2,3-diimine·nickel(II) bromide, Ni12 Similar to Example 1, 2-aminobiphenyl was replaced with 1-aminonaphthalene and 2-methylaniline was replaced with 2,6-dibromoaniline. The amounts of other substances were adjusted according to the corresponding molar ratios, and the operation was similar. A red powder Ni12 (70.1%) was obtained.

[0098] The structure is characterized as follows: MS (ESI) + , m / z): 574.0 [M-Br] + 583.0 [M-2Br] + Elem.Anal. calcd for C 26 H 24 Br2N2Ni: C, 42.04; H, 3.26; N, 3.77. Found: C, 42.10; H, 3.22; N, 3.79. ATR (cm -1 ): 1676.23, 1631.65 (w, v C=N ).

[0099] Example 13 Preparation of (1S,2Z,3E,4S)-1,7,7-trimethyl- N 2 -(naphthyl-2-yl)- N 3 -(o-tolyl)bicyclo[2.2.1]heptane-2,3-diimine·nickel(II) bromide complex, Ni13 Similar to Example 1, 2-aminobiphenyl was replaced with 2-aminonaphthalene, and the amounts of other substances were adjusted according to the corresponding molar ratios, with similar procedures. A brownish-red powder, Ni13 (82.7%), was obtained.

[0100] The structure is characterized as follows: MS (ESI) + , m / z): 519.1 [M-Br] + , 439.2 [M-2Br] + Elem.Anal. calcd for C 27 H 28Br2N2Ni: C, 54.14; H, 4.71; N, 4.68. Found: C, 54.10; H, 4.76; N, 4.63. ATR (cm -1 ): 1690.12, 1623.75 (w, v C=N ).

[0101] Example 14 Preparation of (1S, 2Z, 3E, 4S)- N 2 -(9-anthrayl)-1,7,7-trimethyl- N 3 -(o-tolyl)bicyclo[2.2.1]heptane-2,3-diimine·nickel(II) bromide complex, Ni14 Similar to Example 1, 2-aminobiphenyl was replaced with 9-aminoanthracene, and the amounts of other substances were adjusted according to the corresponding molar ratios, with similar procedures. A brownish-red Ni14 powder (78.9%) was obtained.

[0102] The structure is characterized as follows: MS (ESI) + , m / z): 569.2 [M-Br] + , 489.3 [M-2Br] + Elem.Anal. calcd for C 31 H 30 Br2N2Ni: C, 57.36; H, 4.66; N, 4.32. Found: C, 57.33; H, 4.70; N, 4.37. ATR (cm -1 ): 1665.12, 1601.32 (w, v C=N ).

[0103] Example 15: Application of Aggregate Evaluation The polymerization evaluation conditions were: catalyst Ni complex 0.1 mmol, co-catalyst: Et2AlCl (Al:Ni = 1000:1), polymerization temperature: 30-80 °C. o C, Ethylene pressure: 2.0 MPa, n-hexane volume ratio: 40%, reaction time: 0.5 h. Ethylene polymerization was carried out. Catalytic performance and polymer sample properties are shown in Tables 1 and 2.

[0104] Table 1

[0105] Furthermore, using Et2AlCl as a co-catalyst, the catalytic activity of Ni1 can reach 1.0 × 10⁻⁶ at a polymerization temperature of 70 °C. 7 g·mol -1 (Ni)·h -1 Under the same catalytic conditions, it is 1.2 to 1.5 times more potent than acenaphthene-based framework catalysts; at a polymerization temperature of 80℃, using Et2AlCl as a co-catalyst, the catalytic activity of Ni2 can reach 4.6 × 10⁻⁶. 6 g·mol -1 (Ni)·h -1 Under the same conditions, the activity of acenaphthene-based framework complexes is less than 1×10⁻⁶. 6 g·mol -1 (Ni)·h -1 .

[0106] The catalyst of this invention can catalyze the preparation of polyethylene (52~192 / 1000C's) with low to medium-high branching or even hyperbranching, and has a wide range of applications. The melting points of the resulting polymers are mostly distributed in the range of 30~110℃. The weight-average molecular weight (Mw) of the prepared polyethylene can range from 3 to 28 × 10⁻⁶. 4 g·mol -1 Interval regulation, and a narrow molecular weight distribution (can be less than 2).

[0107] The mechanical properties of the polymer samples obtained, numbered 4, 5, and 6, were evaluated, and the comparison is shown in Table 2.

[0108] Table 2

[0109] The results show that product No. 4, synthesized using the Ni1 catalyst obtained by the method of this invention, has superior mechanical properties, with an average tensile strength of 18.7745 MPa and an average elongation at break of 1020.0001%. The average elongation at break of product No. 4 is significantly improved compared to product No. 5 synthesized using a traditional acenaphthene-based Ni catalyst and product No. 6 synthesized using a symmetrically modified camphene-based Ni catalyst. Furthermore, under the same conditions (60... o C) The catalytic activity of the Ni1 catalyst is as high as 1.51 × 10⁻⁶. 7 g·mol -1 (Ni)·h -1 The catalytic activity is significantly higher than that of traditional acenaphthene-based Ni catalysts (5.7 × 10⁻⁶). 6 g·mol -1 (Ni)·h -1 The catalytic activity of the symmetrically modified camphene-based Ni catalyst is 7.9 × 10⁻⁶. 6 g·mol -1 (Ni)·h -1 .

[0110] In summary, the complexes of this application exhibit significantly superior catalytic activity compared to traditional acenaphthene-based Ni catalysts or symmetrically modified camphene-based Ni catalysts under the same conditions. Furthermore, the catalytic activity of the complexes of this invention at high temperatures is also significantly superior to the aforementioned two types of compounds. In other words, the complexes of this application possess significant advantages in both catalytic activity and thermal stability.

[0111] Furthermore, the test results also show that the elastic properties and toughness of the polymer obtained by the complex catalyst of the present invention are significantly better than those of the Ni complex catalyst without modification of the acenaphthene-based framework.

[0112] The embodiments of the present invention have been described above. However, the present invention is not limited to the above embodiments. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A nickel complex, characterized in that, The nickel complex has the structure shown in Formula I: Formula I Among them, R 1 Ra is unsubstituted, or optionally substituted by at least one Rs; said Rs are selected from C 1-6 Alkyl, F, Cl, Br, I, NO2 or C 1-6 Alkoxy; R 2 R 3 R 4 They are either the same or different, and are independently selected from H, F, Cl, Br, I, and C. 1-6 Alkyl, C 3-6 cycloalkyl, halogenated C 1-6 Alkyl groups, halogenated C 3-6 Cycloalkyl, at least one Rb-substituted C 1-6 Alkyl group, or at least one halogenated Rc-substituted C 1-6 alkyl; Ra, Rb, and Rc may be the same or different, and are independently selected from C. 6-14 aryl or C 5-14 Mixed aromatics; X is selected from F, Cl, Br, I, C 1-6 Alkyl group, where the two Xs are the same or different.

2. The nickel complex according to claim 1, characterized in that, Ra, Rb, and Rc may be the same or different, and are independently selected from biphenyl, phenyl, naphthyl, or anthracene; And / or, the Rs are selected from C 1-3 Alkyl, F, Cl, Br, I, NO2 or C 1-3 Alkyl group.

3. The nickel complex according to claim 1, characterized in that, R 1 The following groups are either unsubstituted or optionally substituted with at least one Rs: biphenyl, phenyl, naphthyl, or anthracene; And / or, R 2 R 3 R 4 They are either the same or different, and are independently selected from H, F, Cl, Br, I, and C. 1-3 Alkyl, C 3-6 cycloalkyl, halogenated C 1-6 Alkyl groups, halogenated C 3-6 Cycloalkyl, phenyl-substituted methyl, diphenyl-substituted methyl, monohalophenyl-substituted methyl, or methyl substituted by two halophenyl groups; And / or, X is selected from F, Cl, Br or I.

4. The nickel complex according to claim 1, characterized in that, R 1 for , , or ; And / or, R 2 R 3 R 4 They may be the same or different, and are independently selected from H, F, Cl, Br, I, methyl, ethyl, and isopropyl. And / or, both X's are the same, selected from Cl or Br.

5. The nickel complex according to claim 1, characterized in that, The nickel complex is selected from any one of Ni1 to Ni14: Complex Ni1: The R 1 = R 2 = R 3 = H, R 4 = Me, X is selected from Br; Complex Ni2: The R 1 = R 2 = H, R 3 = R 4 = Me, X is selected from Br; Complex Ni3: The R 1 = R 2 = H, R 3 = R 4 = i -Pr, X is selected from Br; Complex Ni4: The R 1 = R 2 = H, R 3 = R 4 = Et, X is selected from Br; Complex Ni5: The R 1 = R 2 = H, R 3 = R 4 = Cl, X is selected from Br; Complex Ni6: The R 1 = R 2 = H, R 3 = R 4 = Br, X is selected from Br; Complex Ni7: The R 1 = R 2 = R 3 = H, R 4 = Me, X is selected from Br; Complex Ni8: The R 1 = R 2 = H, R 3 = R 4 = Me, X is selected from Br; Complex Ni9: The R 1 = R 2 = H, R 3 = R 4 = i -Pr, X is selected from Br; Complex Ni10: The R 1 = R 2 = H, R 3 = R 4 = Et, X is selected from Br; Complex Ni11: The R 1 = R 2 = H, R 3 = R 4 = Cl, X is selected from Br; Complex Ni12: The R 1 = R 2 = H, R 3 = R 4 = Br, X is selected from Br; Complex Ni13: The R 1 = R 2 = R 3 = H, R 4 = Me, X is selected from Br; Complex Ni14: The R 1 = R 2 = R 3 = H, R 4 = Me, X is selected from Br.

6. The method for preparing the nickel complex according to any one of claims 1 to 5, characterized in that, The preparation method includes the following steps: Compounds IIa, IIb, and IIc react with compound NiX2 to obtain the complex shown in Formula I; 。 7. The preparation method according to claim 6, characterized in that, The preparation method includes the following steps: Compound IIa and compound IIb were subjected to formic acid reflux, and the reaction solution was dried by rotary evaporation and recrystallized to obtain product I. Product 1, compound IIc, and alkylaluminum were refluxed in toluene and then cooled to room temperature. Product 2 was dissolved in toluene until the system changed color. The reaction was then heated again and cooled to 0±2℃ in an ice-water bath. The reaction was terminated by adding alkali. The organic phase was extracted and collected, washed, evaporated to dryness, and precipitated to obtain the ligand. The ligand reacts with NiX2 at room temperature to obtain the complex shown in Formula I. Alternatively, the preparation method includes the following steps: Compound IIa and compound IIc were subjected to formic acid reflux, and the reaction solution was dried by rotary evaporation and recrystallized to obtain product one. Product 1, compound IIb, and alkylaluminum were refluxed in toluene and then cooled to room temperature. Product 2 was dissolved in toluene until the system changed color. The reaction was then heated again and cooled to 0±2℃ in an ice-water bath. The reaction was terminated by adding alkali. The organic phase was extracted and collected, washed, evaporated to dryness, and precipitated to obtain the ligand. The ligand reacts with NiX2 at room temperature to obtain the complex shown in Formula I.

8. The preparation method according to claim 6, characterized in that, The compound IIb is selected from 2-aminobiphenyl, 1-aminonaphthalene, 2-aminonaphthalene, or 9-aminoanthracene; And / or, the compound IIc is selected from 2-methylaniline, 2,6-dimethylaniline, 2,6-diisopropylaniline, 2,6-diethylaniline, 2,6-dichloroaniline or 2,6-dibromoaniline; And / or, the compound NiX2 is selected from NiCl2, NiBr2, (DME)NiBr2 or (DME)NiCl2.

9. A catalyst or catalyst composition for olefin polymerization, characterized in that, The catalyst or catalyst composition for olefin polymerization comprises the nickel complex according to any one of claims 1 to 5.

10. A method for olefin polymerization, characterized in that, The method includes polymerizing olefins in the presence of the nickel complex of any one of claims 1 to 5, the catalyst of claim 9, or a catalyst composition thereof.

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