A fully flexible alpha-diimine catalyst and its catalytic applications

Abstract

The application discloses a kind of full flexible alpha-diimine catalyst and its catalytic application.The present application uses 1,2-cyclohexanedione as core skeleton, ingeniously grafts flexible and big steric cycloalkylimine group on it, this innovative design greatly improves the efficiency of catalytic system, promotes the generation of higher branching degree and higher molecular weight polyethylene.The prepared polyethylene material is expected to become the darling of new high-performance thermoplastic elastomer by its excellent mechanical properties and excellent elastic recovery capacity.In the palladium-catalyzed ethylene polymerization reaction, this kind of full flexible palladium catalyst shows moderate catalytic activity, and the generated polyethylene product not only has high branch density, but also has significantly improved molecular weight.More strikingly, under the copolymerization experimental conditions, the present application successfully realizes the efficient incorporation of polar monomer methyl acrylate, and prepares copolymer with considerable polar monomer content, which opens up a new path for the modification and functionalization of polyethylene material.

Description

Technical Field

[0001] This invention belongs to the field of catalysis and olefin polymerization, specifically relating to a fully flexible α-diimide catalyst and its catalytic applications. Background Technology

[0002] In late-stage transition metal-catalyzed ethylene polymerization, the axial shielding effect plays a crucial role. This effect primarily stems from its inhibition of β-H elimination and subsequent chain transfer. Since the development of the Brookhart system in the mid-1990s, various axial shielding substituents have been widely applied in late-stage transition metal-catalyzed α-diimine systems.

[0003] Based on their conformational flexibility, these axially shielded substituents can be broadly classified into two categories: rigid substituents and flexible substituents. Representative rigid α-diimide catalysts include o-aryl aryl catalysts, o-aryldimethyl catalysts, and 8-arylnaphthyl catalysts. These catalysts effectively suppress chain transfer reactions during polymerization, thereby producing high-molecular-weight and even ultra-high-molecular-weight polyethylene. Furthermore, the different orientations of these rigid aryl groups significantly influence the branching density of the resulting polyethylene. Compared to rigid substituents, introducing flexible alkyl or cycloalkyl groups at the axial position of the catalytic center can create a dynamically variable steric environment. This flexibility effectively promotes the coordination and insertion reactions of ethylene in most cases, thereby enhancing catalytic activity. In addition, the spatial environment near the catalytic center is also conducive to chain travel and branching formation. In recent years, sterically hindered rigid frameworks have frequently been incorporated into the design of α-diimide catalysts, with the dibenzo[a]benzene framework being particularly well-known. This axial steric framework, in synergy with axial substituents, has promoted the realization of living polymerization and even high-temperature living polymerization in numerous catalytic systems. In addition to exhibiting the common characteristics of living polymerization, these catalysts can also synthesize hyperbranched polyethylene with monomethyl branching. However, these classic and rigid catalysts suffer from drawbacks such as poor solubility, easy deposition and clogging of pipelines in industrial production, and limited catalytic activity. These limitations restrict their use in certain industrial scale-up applications, especially where efficient large-scale production is required.

[0004] Given the poor solubility of classic and rigid framework catalysts in alkane solvents, often requiring toluene as the reaction solvent, the innovative, fully flexible catalyst designed in this invention exhibits significant advantages in commonly used industrial alkane polymerization solvents. By introducing a large number of solubilizing cycloalkyl substituents, this catalyst achieves highly efficient dispersion in commonly used industrial alkanes, effectively avoiding production problems such as catalyst deposition and pipeline blockage. Furthermore, its fully flexible substituent structure not only enhances the catalyst's adaptability but also significantly improves the activity of ethylene polymerization, bringing higher efficiency and benefits to industrial production. Summary of the Invention

[0005] To address the shortcomings of the existing technology, this invention provides an α-diimine catalyst with a flexible cyclohexyl framework and axially flexible cycloalkyl substituents, and uses it to catalyze olefin polymerization.

[0006] The present invention relates to an α-diimine catalyst having a flexible cyclohexyl framework and axially flexible cycloalkyl substituents, the general structural formula of which is shown below:

[0007] .

[0008] R = cyclopentyl (Cp) or cyclohexyl (Ch), etc.;

[0009] M = Ni, X = Y = Br; or, M = Pd, X = Cl, Y = Me.

[0010] The α-diimine catalyst is preferably:

[0011] Ni1: R = Cp, X = Y = Br;

[0012] Ni2: R = Ch, X = Y = Br;

[0013] Pd1: R = Cp, X = Cl, Y = Me;

[0014] Pd2: R = Ch, X = Cl, Y = Me.

[0015]

[0016] The present invention discloses a method for preparing an α-diimine catalyst having a flexible cyclohexyl framework and axially flexible cycloalkyl substituents, comprising the following steps:

[0017] Step 1: Preparation of ligands

[0018] A methanol solution (5 mL) containing 3 mmol of tricycloalkyl aromatic amine (A1 or A2) was added to 1.4 mmol of 1,2-cyclohexanedione, and a few drops of acetic acid were added as a catalyst. The mixture was stirred at room temperature for two days. After the reaction was completed, the precipitate was separated by filtration, washed with methanol (3 × 2 mL), and dried under vacuum to obtain ligand L1 or L2. No further purification was required, and it was used directly for the preparation of subsequent catalysts.

[0019] In step 1, the molar ratio of 1,2-cyclohexanedione to tricycloalkylarylamine is 1:2.0-2.5.

[0020] Step 2: Catalyst Preparation

[0021] 2a. Under a nitrogen atmosphere, a mixture containing 0.2 mmol of ligand and an equimolar amount of (DME) NiBr2 was dissolved in 10 mL of dichloromethane and stirred at room temperature for 8-12 h until the solution color deepened significantly. After the reaction was completed, the solvent was partially evaporated, and the remaining mixture was diluted with 20 mL of anhydrous ether to precipitate an orange-red solid. The solid was separated by filtration, thoroughly washed with diethyl ether, and dried under vacuum to obtain the target product Ni1 or Ni2 compound.

[0022] 2b. Under a nitrogen atmosphere, a mixture containing 0.4 mmol of ligand and an equimolar amount (COD) of PdMeCl was dissolved in 10 mL of dichloromethane and stirred at room temperature for 8–12 h. After the reaction was complete, part of the solvent was removed, and the remaining mixture was diluted with 20 mL of diethyl ether to obtain an orange-red solid precipitate. The solid was filtered, washed with diethyl ether, and dried under vacuum to obtain the target product, Pd1 or Pd2 compound.

[0023] The synthesis route is shown below:

[0024]

[0025] This invention relates to the application of α-diimine catalysts with a flexible cyclohexyl skeleton and axially flexible cycloalkyl substituents in catalytic olefin polymerization reactions.

[0026] The olefin is preferably ethylene.

[0027] The polymerization reaction is carried out in a composite catalytic system formed by a catalyst and a co-catalyst, wherein the co-catalyst is Et2AlCl or NaBArF.

[0028] Furthermore, during the catalytic homopolymerization of ethylene:

[0029] The catalyst is Ni1 or Ni2, and the co-catalyst is Et2AlCl. The molar ratio of catalyst to co-catalyst Et2AlCl is 1:200 to 1:1000, and the amount of catalyst used is 1 to 10 micromoles. The temperature of the ethylene polymerization reaction is controlled between 30°C and 90°C, the ethylene polymerization pressure is maintained at 6 to 30 atm, 40 to 100 mL of cyclohexane is used as solvent, and the reaction time lasts for 30 to 60 minutes.

[0030] The catalyst is Pd1 or Pd2, and the co-catalyst is NaBArF. The molar ratio of the catalyst to NaBArF is in the range of 1:1 to 1:3, and the amount of catalyst used is 2 to 10 micromoles. The temperature of the ethylene polymerization reaction is controlled between 30°C and 70°C, the ethylene pressure is maintained at 6 to 10 atmospheres, 40 to 100 mL of dichloromethane is used as the solvent, and the reaction time lasts for 60 to 120 minutes.

[0031] Furthermore, in the copolymerization process of catalyzing ethylene and acrylate monomers:

[0032] The catalyst is Pd1 or Pd2, and the co-catalyst is NaBArF. The molar ratio of the catalyst to the co-catalyst NaBArF ranges from 1:1 to 1:3, the amount of catalyst used is 10 to 20 micromoles, and the concentration of the acrylate monomer is 1 to 2 mol / L. The reaction temperature is controlled between 30 and 70°C, the ethylene pressure is maintained at 2 to 10 atm, 20 to 100 mL of dichloromethane is used as the solvent, and the reaction time lasts for 3 to 12 hours.

[0033] The preferred acrylate monomer is methyl acrylate.

[0034] The fully flexible α-diimine nickel catalyst of this invention, with its backbone and axially cycloalkyl substituents, exhibits high efficiency (10) in ethylene homopolymerization. 6 g·mol -1 ·h -1 This study utilizes a flexible nickel catalyst to produce polyethylene materials with high molecular weight (up to 1022 kg / mol) and high branch density (up to 10³ / 1000C). These polyethylenes exhibit high branch density and low melting point, displaying the characteristics of polyolefin elastomers. Tensile tests show that these polyethylenes exhibit low tensile strength (2.1–7.0 MPa) and high fracture strain (592–2248%) at fracture. Furthermore, hysteresis tests demonstrate that these materials possess good elastic recovery, making them high-performance thermoplastic elastomers. Interestingly, the flexible nickel catalyst reported in this study exhibits higher polymerization activity and yields higher molecular weight polyethylene products compared to previously reported nickel catalysts with classic and rigid frameworks.

[0035] Meanwhile, the fully flexible α-diimine palladium catalyst of the present invention exhibits moderate polymerization activity (10) in ethylene homopolymerization. 5 g·mol -1 ·h -1 This process yields high molecular weight (56-203 kg / mol) and high branch density (87-99 / 1000C) polyethylene. Due to the strong tolerance of palladium catalysts to polar groups, we applied them to the copolymerization of ethylene and methyl acrylate (EMA). These catalysts exhibit lower copolymerization activity (10...). 3 g·mol -1 ·h -1 It can generate highly branched (96-120 / 1000C) and medium molecular weight (16-40 kg / mol) E-MA copolymers, in which the MA incorporation rate is 1.53-4.54 mol%. Although the copolymerization activity decreases and the molecular weight of the resulting copolymer also decreases, the branching density remains relatively stable.

[0036] This invention uses 1,2-cyclohexanedione as its core framework and ingeniously grafts flexible and sterically hindered cycloalkylimine groups onto it. This innovative design greatly enhances the efficiency of the catalytic system, promoting the formation of polyethylene with higher branching density and higher molecular weight. The resulting polyethylene material, with its excellent mechanical properties and superior elastic recovery, is expected to become a new favorite among high-performance thermoplastic elastomers. In palladium-catalyzed ethylene polymerization, this type of fully flexible palladium catalyst exhibits moderate catalytic activity, and the resulting polyethylene product not only has high branching density but also significantly increased molecular weight. More notably, under copolymerization experimental conditions, this invention successfully achieved the efficient incorporation of the polar monomer methyl acrylate (MA), obtaining copolymers with a considerable content of polar monomers, opening up new pathways for the modification and functionalization of polyethylene materials. Attached Figure Description

[0037] Figure 1 The figures (a), molecular weight (b), and branching density (c) of polyethylene prepared using the catalysts of Examples 1 and 2 at 30°C–90°C are shown. Figure 1 As can be seen, both flexible nickel catalysts exhibited extremely high polymerization activity in the presence of 200 equivalents of co-catalyst, with minimal activity changes at different temperatures, demonstrating good thermal stability. Furthermore, under the exploratory conditions, these catalysts efficiently produced polyethylene materials with high molecular weight (up to 1022 kg / mol) and high branching density (up to 10³ / 1000°C). The molecular weight of the resulting polyethylene decreased with increasing temperature, while the branching density increased accordingly. Regarding the effect of axial cycloalkyl ring size on the polymerization results, the cyclohexyl catalyst with larger rings exhibited slightly lower polymerization activity compared to the cyclopentyl catalyst, but produced polyethylene with higher molecular weight and higher branching density.

[0038] Figure 2 This section compares the activity, molecular weight, and branching density of the catalyst in Example 2 with those of previously reported nickel catalysts with classical and rigid frameworks for ethylene polymerization under similar conditions. Figure 2 As can be seen, compared with the classic butyl nickel catalyst BD-Ni, the Ni2 catalyst with a flexible cyclohexyl framework produced polyethylene with a significantly higher molecular weight and slightly higher branching density under similar conditions, while exhibiting higher catalytic activity. Furthermore, compared with the dibenzo-p-benzene nickel catalyst DB-Ni, Ni2 produced polyethylene with a similar molecular weight under the same conditions, but with a significantly lower branching density and a markedly higher activity. These results indicate that the combination of skeletal flexibility and the adaptability of axial cyclohexyl shielding can effectively suppress chain transfer and promote chain growth during nickel-catalyzed ethylene polymerization.

[0039] Figure 3The stress-strain curves of polyethylene prepared from catalysts of Example 1 (a) and Example 2 (b) at 30°C-90°C are shown. Figure 3 As can be seen, the polyethylene obtained exhibits low tensile strength at break (2.1-7.0 MPa) and high elongation at break (592%-2248%). Furthermore, as the production temperature increases, the tensile strength gradually decreases while the elongation at break gradually increases.

[0040] Figure 4 Hysteresis curves are shown for polyethylene prepared using catalysts (ad) of Example 1 and (eh) of Example 2 at 30°C–90°C after 10 cycles at 300% strain. Figure 4 As can be seen, these materials have good elastic recovery capabilities. It is worth noting that the strain recovery (SR) value does not always increase with increasing temperature; it peaks at 50°C (for Ni1) or 70°C (for Ni2) and then begins to decline.

[0041] Figure 5 The yield (a), molecular weight (b), and branch density (c) of polyethylene prepared using the catalysts of Examples 3 and 4 at 30°C-70°C are shown. Figure 4 As can be seen, these palladium complexes exhibit moderate polymerization activity and produce polyethylene with high molecular weight (56-203 kg / mol) and high branching density (87-99 / 1000°C). In most cases, both polymerization activity and the molecular weight of the resulting polyethylene decrease with increasing temperature, while the branching density of the resulting polyethylene remains relatively stable. The size of the axial cycloalkyl group also plays a crucial role in palladium-catalyzed ethylene polymerization, with cyclohexylpalladium catalysts exhibiting lower polymerization activity and producing polyethylene with higher molecular weight and lower branching density.

[0042] Figure 6 The yield (a), MA insertion ratio (b), molecular weight (c), and degree of branching (d) of the catalysts used in Examples 3 and 4 for the preparation of ethylene and MA copolymers at 30°C are shown. Figure 6 As can be seen, these catalysts exhibit low copolymerization activity and produce medium molecular weight (16-40 kg / mol) and highly branched (96120 / 1000C) ethylene-methyl acrylate (E-MA) copolymers, with MA incorporation ranging from 1.53% to 4.54% mol. With increasing MA concentration, the copolymerization activity decreases, the molecular weight of the resulting copolymer also decreases, while the branching density remains relatively stable.

[0043] Figure 7 Detailed carbon spectral assignments are provided for the preparation of ethylene and MA copolymers using the catalyst in Example 4 at 30°C and a concentration of 1M MA. From... Figure 7 As can be seen, these ethylene-methyl acrylate (E-MA) copolymers contain various types of branched structures, mainly long-chain branching, with polar groups located at the ends of these long-chain branchings. Detailed Implementation

[0044] 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 not for limiting the scope of the claims of the present invention. Reagents and raw materials used in the embodiments: All organometallic reactions were carried out under nitrogen protection, and all solvents were dried and deoxygenated. Ethanol was analytical grade and used directly.

[0045] Example 1:

[0046] 1. Synthesis of L1, a fully flexible catalyst ligand

[0047] A methanol solution (5 mL) containing 3 mmol of 2,4,6-tricyclopentyl-1-aniline was added to 1.4 mmol of 1,2-cyclohexanedione, followed by a few drops of acetic acid. The synthesized mixture was then stirred at room temperature for two days. Subsequently, the precipitate was separated by filtration and washed with methanol (3 × 2 mL). Ligand L1 was dried under vacuum and used directly in subsequent steps without further purification, with a yield of 75%.

[0048] The preparation reaction formula is as follows:

[0049]

[0050] NMR analysis: 1 H NMR (400 MHz, CDCl3) δ 7.03 (d, J = 10.7 Hz, 4H, Ar-H), 6.32 (s, 1H, -CH=C-), 4.77 (s, 1H, -NH-), 3.24 (p, J = 8.5 Hz, 2H, -CH-), 3.06-2.73 (m, 4H, -CH-), 2.28-1.93 (m, 13H, -CH2-), 1.91-1.35 (m, 41H, -CH2-). 13C NMR (101 MHz, CDCl3) δ 162.35 (C=N), 145.43, 144.71, 143.95, 139.24,135.81, 133.76, 130.14, 122.77, 122.31, 122.23, 104.72 (C=C-CH2-), 46.34 (-CH-), 46.31 (-CH-), 46.18 (-CH-), 46.06 (-CH-), 40.93 (-CH-), 40.54 (-CH-), 35.24 (-CH2-), 35.04 (-CH2-), 34.94 (-CH2-), 34.88 (-CH2-), 33.79 (-CH2-),32.52 (-CH2-), 29.59 (-CH2-), 26.07 (-CH2-), 25.92 (-CH2-), 25.87 (-CH2-),25.65 (-CH2-), 25.62 (-CH2-), 25.56 (-CH2-), 25.35 (-CH2-), 24.35 (-CH2-), 23.66 (-CH2-).

[0051] Mass spectrometry analysis: APCI-MS (m / z): calcd for C 48 H 67 N2 + : 671.5299, Found, 671.5268,[M+H] + .

[0052] 2. Synthesis of Ni1 complex

[0053] Under a nitrogen atmosphere, a mixture containing 0.2 mmol of the ligand and an equal amount of (DME)NiBr2 was introduced into 10 mL of dichloromethane. This mixture was then stirred overnight at room temperature, resulting in a significant deepening of the solution's color. After the reaction was complete, the solvent was partially evaporated under reduced pressure. The remaining mixture was then diluted with 20 mL of anhydrous ether, causing a precipitate of an orange-red solid. The solid was then separated by filtration, rigorously washed with diethyl ether, and finally dried under vacuum to obtain the target Ni1 compound in 88% yield.

[0054] The preparation reaction formula is as follows:

[0055]

[0056] Mass spectrometry analysis: MALDI-TOF-MS (m / z): calcd for C 48 H 66BrN2Ni: 807.3757, Found,807.3768, [M-Br] + .

[0057] Example 2:

[0058] 1. Synthesis of L2, a fully flexible catalyst ligand

[0059] Replace 2,4,6-tricyclopentyl-1-aniline in step 1 of Example 1 with 2,4,6-tricyclohexyl-1-aniline, and the rest of the operation is the same as step 1 of Example 1, with a yield of 60%.

[0060] NMR analysis: 1 H NMR (400 MHz, CDCl3) δ 6.96 (d, J = 14.7 Hz, 4H, Ar-H), 6.15 (s, 1H, -CH=C-), 4.68 (d, J = 4.7 Hz, 1H, -NH-), 2.84 (t, J = 11.4 Hz,2H, -CH-), 2.46 (t, J = 12.0 Hz, 4H, -CH-), 2.19 (q, J = 7.1, 5.7 Hz, 4H, -CH2-), 1.79 (dtd, J = 53.0, 26.3, 25.7, 10.8 Hz, 32H, -CH2-), 1.36 (ddd, J =45.1, 21.6, 10.8 Hz, 30H, -CH2-). 13C NMR (101 MHz, CDCl3) δ 162.81 (C=N),145.78, 145.43, 143.54, 143.52, 142.48, 139.41, 135.30, 135.25, 133.69,133.62, 122.54, 122.02, 104.45 (C=C-CH2-), 44.65 (-CH-), 44.47 (-CH-), 39.12(-CH-), 39.02 (-CH-), 34.80 (-CH2-), 34.77 (-CH2-), 34.63 (-CH2-), 34.22 (-CH2-), 34.18 (-CH2-), 33.77 (-CH2-), 29.77 (-CH2-), 27.44 (-CH2-), 27.39 (-CH2-), 27.34 (-CH2-), 27.30 (-CH2-), 27.26 (-CH2-), 27.21 (-CH2-), 27.15 (-CH2-), 27.11 (-CH2-), 27.07 (-CH2-), 27.02 (-CH2-), 26.39 (-CH2-), 26.38 (-CH2-), 26.32 (-CH2-), 26.29 (-CH2-), 24.40 (-CH2-), 24.39 (-CH2-), 24.36 (-CH2-), 23.67 (-CH2-), 23.64 (-CH2-).

[0061] Mass spectrometry analysis: APCI-MS (m / z): calcd for C 54 H 79 N2 + : 755.6238, Found, 755.6237,[M+H] + .

[0062] 2. Synthesis of Ni2 complex

[0063] Replace L1 with L2 in step 2 of Example 1, and the rest of the operation is the same as step (2) of Example 1, with a yield of 90%.

[0064] Mass spectrometry analysis: MALDI-TOF-MS (m / z): calcd for C 54 H 78 BrN2Ni: 891.4696, Found,891.4679, [M-Br] + .

[0065] Example 3: Synthesis of Pd1 complex

[0066] A mixture containing 0.4 mmol of ligand L1 and an equal amount of (COD) PdMeCl was introduced into 10 mL of dichloromethane. The resulting solution was stirred overnight at room temperature, during which its color intensified. After the reaction was complete, some of the solvent was removed under reduced pressure, and the remaining mixture was diluted with 20 mL of diethyl ether to give an orange-red solid precipitate. Subsequently, the solid was filtered, washed with diethyl ether, and dried under vacuum to give the target product Pd1. The yield was 75%. The preparation reaction formula is as follows:

[0067]

[0068] NMR analysis: 1 H NMR (400 MHz, CDCl3) δ 7.07 (d, J = 15.2 Hz, 4H, Ar-H), 3.03 (dp, J = 48.3, 8.6 Hz, 6H, -CH-), 2.43 (p, J = 5.6 Hz, 2H, -CH2-), 2.24(dt, J = 25.3, 6.1 Hz, 6H, -CH2-), 2.14-1.97 (m, 5H, -CH2-), 1.91-1.50 (m,43H, -CH2-), 0.53 (s, 3H, Pd-CH3). 13C NMR (101 MHz, CDCl3) δ 175.13 (C=N),170.42 (C=N), 145.32, 144.06, 141.13, 140.56, 135.64, 134.47, 123.69, 122.90,122.42, 45.96 (-CH-), 45.93 (-CH-), 45.80 (-CH-), 41.30 (-CH-), 40.55 (-CH-), 40.52 (-CH-), 35.58 (-CH2-), 34.72 (-CH2-), 34.64 (-CH2-), 34.60 (-CH2-)),34.43 (-CH2-), 34.39 (-CH2-), 34.29 (-CH2-), 34.08 (-CH2-), 33.89 (-CH2-),33.80 (-CH2-), 33.39 (-CH2-), 33.34 (-CH2-), 32.31 (-CH2-), 32.20 (-CH2-),32.03 25.48 (-CH2-), 25.44(-CH2-), 23.87 (-CH2-), 21.60 (-CH2-), 21.57 (-CH2-), 2.76 (Pd-CH3).

[0069] Mass spectrometry analysis: MALDI-TOF-MS (m / z): calcd for C 48 H 66 N2Pd: 776.4255, Found,776.4285, [M-Cl-Me] + .

[0070] Example 4: Synthesis of Pd2 complex

[0071] Replace L1 with L2 in step 1 of Example 3, and the rest of the operation is the same as step (1) of Example 3, with a yield of 60%.

[0072] NMR analysis: 11H NMR (400 MHz, CDCl3) δ 7.01 (d, J = 16.4 Hz, 4H, Ar-H), 2.47 (d, J = 24.4 Hz, 6H, -CH-), 2.27 (d, J = 9.7 Hz, 4H, -CH2-), 1.85 (s, 20H, -CH2-), 1.58 (d, J = 32.0 Hz, 32H, -CH2-), 1.42 (d, J = 10.0 Hz, 12H, -CH2-), 0.52 (s, 3H, Pd-CH3). 13 13C NMR (101 MHz, CDCl3) δ 175.32 (C=N), 170.61 (C=N), 148.09, 137.36, 136.95, 136.23, 123.10, 122.86, 122.46, 44.42 (-CH-), 44.37 (-CH-), 43.35 (-CH-), 40.37 (-CH-), 39.85 (-CH-), 39.25 (-CH-), 34.86 (-CH2-), 34.75 (-CH2-), 34.53 (-CH2-), 34.48 (-CH2-), 34.46 (-CH2-), 34.36 (-CH2-), 33.73 (-CH2-), 33.58 (-CH2-), 33.43 (-CH2-), 29.80 (-CH2-), 29.73 (-CH2-), 29.35 (-CH2-), 27.28 (-CH2-), 27.23 (-CH2-), 27.20 (-CH2-), 27.03 (-CH2-), 26.97 (-CH2-), 26.92 (-CH2-), 26.26 (-CH2-), 26.18 (-CH2-), 26.17 (-CH2-), 26.10 (-CH2-), 1.05 (Pd-CH3).

[0073] Mass spectrometry: MALDI-TOF-MS (m / z): calcd for C 54 H 78 N2Pd: 860.5194, Found, 860.5211, [M-Cl-Me] + .

[0074] Example 5:

[0075] 1. Applications of Ni1 and Ni2 in catalytic ethylene polymerization

[0076] In the standard experimental procedure, a 350 mL thick-walled glass pressure vessel was dried in a hot air circulating oven at 60 °C for 2 hours. After cooling to room temperature, 40 mL of cyclohexane and 200 g of diethylaluminum chloride were injected into the vessel under nitrogen-rich conditions. 1 μmol of Ni(II) catalyst was dissolved in 1 mL of CH₂Cl₂ and injected into the polymerization system using a syringe. The reactor was pressurized to maintain a constant 6 atm ethylene concentration under vigorous stirring at 350 RPM. After 30 minutes, the reactor was depressurized, and the resulting polymer precipitated in ethanol. Subsequently, the polymer was filtered and then dried under vacuum at 50 °C for at least 24 hours.

[0077] 2. Applications of Pd1 and Pd2 in catalytic ethylene polymerization

[0078] In a typical experiment, a 350 mL thick-walled glass pressure vessel was dried in a hot air circulating oven at 60 °C for 2 hours. After cooling to room temperature, 40 mL of CH₂Cl₂ and 2 equal volumes of NaBArF were added to the vessel under a nitrogen atmosphere. 2 μmol of Pd(II) catalyst was added to 2 mL of CH₂Cl₂ and injected into the polymerization system via a syringe. The reactor was pressurized and maintained at 6 atm of ethylene under rapid stirring (350 rpm). After 1 hour, the pressure reactor was vented, and the polymer was dried under reduced pressure using a rotary evaporator.

[0079] 3. Application of Pd1 and Pd2 in the catalytic copolymerization of ethylene and methyl acrylate

[0080] In a typical experiment, a 350 mL thick-walled glass pressure vessel was dried in a hot air circulating oven at 60 °C for 2 hours. After cooling to room temperature, 18 mL of CH₂Cl₂, 2 equal amounts of NaBArF, and 20 or 40 mmol of methyl acrylate monomer were added to the vessel under a nitrogen atmosphere. 10 μmol of Pd(II) catalyst was added to 2 mL of CH₂Cl₂ and injected into the polymerization system via a syringe. The reactor was pressurized and maintained at 2 atm of ethylene under rapid stirring (350 rpm). After 12 hours, the pressure reactor was vented, and the polymer was dried under reduced pressure using a rotary evaporator.

[0081] The table below shows the experimental conditions for ethylene polymerization using the catalyst provided by this invention; Complex, Temperature (T), Yield, Catalytic Activity (Act). b .), polymer molecular weight (M) n c ), branching degree (brs) dAggregated results data such as )

[0082]

[0083] a Polymerization conditions: catalyst 1 μmol, dichloromethane = 2 mL, [Al] / [Ni] = 200 equivalents, cyclohexane = 40 mL, ethylene pressure 6 atm, time = 30 min;

[0084] b The unit of active Act is 10. 6 g·mol -1 ·h -1 ;

[0085] c Polymer molecular weight M n and M w and molecular weight (M) w / M n The distribution was determined by GPC in trichlorobenzene at 150°C;

[0086] d Branching degree refers to the number of branches per 1000 carbon atoms, determined by... 1 Measured by H NMR nuclear magnetic resonance method;

[0087] e The polymer melting point was determined by differential scanning calorimetry (DSC).

[0088]

[0089] a Polymerization conditions: catalyst 2 μmol, dichloromethane = 40 mL, NaBArF = 2 equivalents, ethylene pressure 6 atm, time = 60 min;

[0090] b The unit of active Act is 10. 5 g·mol -1 ·h -1 ;

[0091] c Polymer molecular weight M n and M w and molecular weight (M) w / M n The distribution was determined by GPC in THF at 40°C;

[0092] d Branching degree refers to the number of branches per 1000 carbon atoms, determined by... 1 Determined by H NMR nuclear magnetic resonance method.

[0093]

[0094] a Polymerization conditions: catalyst 10 μmol, dichloromethane and MA = 40 mL, NaBArF = 2 equivalents, ethylene pressure 2 atm, time = 12 hours, temperature 30℃;

[0095] b The unit of active Act is 10. 3 g·mol -1 ·h -1 ;

[0096] c MA insertion ratio is determined by 1 Measured by H NMR nuclear magnetic resonance method;

[0097] c Polymer molecular weight M n and M w and molecular weight (M) w / M n The distribution was determined by GPC in THF at 40°C;

[0098] d Branching degree refers to the number of branches per 1000 carbon atoms, determined by... 1 Determined by H NMR nuclear magnetic resonance method.

[0099] This invention details a method for preparing ligand compounds, complex catalysts, catalyst combinations, and olefin polymers. To more clearly illustrate the principles and implementation methods of this invention, specific examples are provided in detail. However, it should be emphasized that the application of this invention is not limited to the specific embodiments described herein. Those skilled in the art should understand that various modifications and variations can be made to this invention without departing from its core scope. These improvements and modifications based on the principles of this invention also fall within the protection scope of the claims of this invention.

Claims

1. A fully flexible α-diimine catalyst, characterized in that... Its general structural formula is as follows: ； R = cyclopentyl or cyclohexyl; M = Ni, X = Y = Br; or, M = Pd, X = Cl, Y = Me.

2. The fully flexible α-diimine catalyst according to claim 1, characterized in that... Its structure is as follows: 。 3. The method for preparing the fully flexible α-diimine catalyst according to claim 1, characterized in that... Includes the following steps: Step 1: Preparation of ligands A methanol solution containing tricyclic alkyl aromatic amines was added to 1,2-cyclohexanedione, and acetic acid was added dropwise as a catalyst. The mixture was stirred at room temperature for two days. After the reaction was completed, the precipitate was separated by filtration, washed with methanol, and dried under vacuum to obtain ligands L1 or L2. Step 2: Catalyst Preparation 2a. Under a nitrogen atmosphere, the ligand obtained in step 1 and an equimolar amount of (DME) NiBr2 were dissolved in dichloromethane and stirred at room temperature for 8-12 h. After the reaction was completed, the solvent was partially evaporated, the remaining mixture was diluted with anhydrous ether, an orange-red solid was precipitated, the solid was separated by filtration, washed with diethyl ether and dried under vacuum to obtain the target product Ni1 or Ni2 compound. 2b. Under a nitrogen atmosphere, the ligand obtained in step 1 and an equimolar amount (COD) of PdMeCl were dissolved in dichloromethane and stirred at room temperature for 8-12 h. After the reaction was completed, part of the solvent was removed, and the remaining mixture was diluted with diethyl ether to obtain an orange-red solid precipitate. The solid was separated by filtration, washed with diethyl ether and dried under vacuum to obtain the target product Pd1 or Pd2 compound. The synthesis route is shown below: 。 4. The preparation method according to claim 3, characterized in that: In step 1, the molar ratio of 1,2-cyclohexanedione to tricycloalkylarylamine is 1:2.0-2.

5.

5. The application of the fully flexible α-diimine catalyst according to claim 1 in the catalytic polymerization reaction of olefins, characterized in that: The polymerization reaction is carried out in a composite catalytic system formed by a catalyst and a co-catalyst, wherein the co-catalyst is Et2AlCl or NaBArF.

6. The application according to claim 5, characterized in that: The olefin is ethylene.

7. The application according to claim 6, characterized in that: In the process of catalytic ethylene homopolymerization: The catalyst is Ni1 or Ni2, and the co-catalyst is Et2AlCl; the molar ratio of catalyst to co-catalyst Et2AlCl is 1:200-1:1000, and the amount of catalyst used is 1-10 micromoles; the temperature of the ethylene polymerization reaction is controlled between 30℃ and 90℃, the ethylene polymerization pressure is maintained at 6-30 atm, 40mL-100mL of cyclohexane is used as solvent, and the reaction time lasts for 30-60 minutes.

8. The application according to claim 6, characterized in that: In the process of catalytic ethylene homopolymerization: The catalyst is Pd1 or Pd2, and the co-catalyst is NaBArF; the molar ratio of the catalyst to NaBArF is in the range of 1:1-1:3, and the amount of catalyst used is 2-10 micromoles; the temperature of the ethylene polymerization reaction is controlled between 30℃ and 70℃, the ethylene pressure is maintained at 6-10 atm, 40mL-100mL of dichloromethane is used as solvent, and the reaction time lasts for 60-120 minutes.

9. The application according to claim 6, characterized in that: In the copolymerization process of catalyzed ethylene and acrylate monomers: The catalyst is Pd1 or Pd2, and the co-catalyst is NaBArF; the molar ratio of the catalyst to the co-catalyst NaBArF is in the range of 1:1-1:3, the amount of catalyst used is 10-20 micromoles, and the concentration of acrylate monomer is 1-2 mol / L; the reaction temperature is controlled between 30-70℃, the ethylene pressure is maintained at 2-10 atm, 20mL-100mL of dichloromethane is used as solvent, and the reaction time lasts for 3-12 hours.

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