A pyridinamine ligand-scandium complex, a preparation method thereof and application thereof in catalytic preparation of polyisobutylene

Abstract

The application provides a pyridine amine ligand-scandium complex, a preparation method thereof and application thereof in catalytic preparation of polyisobutylene, and belongs to the technical field of catalysts.The pyridine amine ligand-scandium complex provided by the application has a structure shown in any one of formula I to formula III.The pyridine amine ligand (pyridine imine or pyridine amine) is used to complex with trivalent scandium, the structure of polyisobutylene and the reaction rate can be better controlled by changing the skeleton of the ligand, and the polymerization of isobutylene can be better realized.The results of examples show that, by using the pyridine amine ligand-scandium complex as a catalyst and by using a cocatalyst, the polymerization reaction of isobutylene can be realized at room temperature of 25 DEG C, and low-molecular-weight polyisobutylene is obtained.

Description

Technical Field

[0001] This invention relates to the field of catalyst technology, and in particular to a pyridine amine ligand-scandium complex, its preparation method, and its application in the catalytic preparation of polyisobutylene. Background Technology

[0002] Polyisobutylene is a colorless, odorless, and non-toxic homopolymer of isobutylene, and its chemical structure is a typical linear saturated polymer. The main part of its molecular backbone consists of repeating units -CH2-C(CH3)2-, with a head of -CH3 and ends of -CH2-C(CH3)=CH2 or -CH=C(CH3)2. Due to differences in preparation methods and production processes, the molecular weight of polyisobutylene can vary within a wide range. Based on molecular weight, polyisobutylene can be classified into high molecular weight polyisobutylene (Mn>100,000), medium molecular weight polyisobutylene (Mn 10,000–100,000), and low molecular weight polyisobutylene (Mn<10,000).

[0003] Polyisobutylene (POI) possesses excellent properties such as resistance to acids, alkalis, water, salts, ozone, and aging, as well as good gas barrier properties and electrical insulation. It also exhibits good compatibility with asphalt, waxes, and polyethylene. Currently, the PII industry has developed various polymerization methods to obtain PII. From the perspective of catalysts, they can be divided into two categories: aluminum-based PII and boron-based PII. Essentially, these are cationic polymerizations, where aluminum or boron reagents form cations in the reaction system, thereby inducing monomer polymerization. During polymerization, intramolecular rearrangement, transfer, and isomerization side reactions are prone to occur, making the structure of PII difficult to control and susceptible to explosive polymerization. Therefore, the reaction process must be carried out at extremely low temperatures (-60°C). Summary of the Invention

[0004] In view of this, the present invention aims to provide a pyridine amine ligand-scandium complex, its preparation method, and its application in the catalytic preparation of polyisobutylene. When the pyridine amine ligand-scandium complex provided by the present invention is used as a catalyst for the synthesis of polyisobutylene, it enables the room-temperature synthesis of polyisobutylene.

[0005] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0006] This invention provides a pyridineamine ligand-scandium complex having the structure shown in any one of Formulas I to III:

[0007]

[0008] In Equations I to III, R 1 It can be a hydrogen atom or a methyl group;

[0009] R 3 It is a hydrogen atom;

[0010] R 2 It is a hydrogen atom or the structure shown in any one of Formulas 1 to 11:

[0011]

[0012] X is either Cl or acac.

[0013] Preferably, it has the structure shown in any one of Sc-1 to Sc-15:

[0014]

[0015]

[0016] This invention provides a method for preparing the above-mentioned pyridineamine ligand-scandium complex, comprising the following steps:

[0017] A soluble trivalent scandium source, pyridine amine ligands, and an organic solvent were mixed and subjected to a complexation reaction to obtain pyridine amine ligand-scandium complexes.

[0018] The soluble trivalent scandium source is ScCl3 or Sc(acac)3;

[0019] The pyridineamine ligand has the structure shown in any one of formulas (1) to (3):

[0020]

[0021] Preferably, the complexation reaction is carried out at a temperature of 0–30°C for a time of 12–72 h.

[0022] Preferably, the molar ratio of the soluble trivalent scandium source to the pyridineamine ligand is 1:1 to 5.

[0023] Preferably, the method for preparing the pyridineamine ligand having the structure shown in formula (2) includes the following steps:

[0024] In the presence of a catalyst, a primary amine having the structure shown in formula a undergoes an amine-aldehyde condensation reaction with a pyridine-2-carboxaldehyde compound having the structure shown in formula b to obtain a pyridine amine ligand having the structure shown in formula (2).

[0025] R 2 -NH2 formula a;

[0026] The method for preparing the pyridineamine ligand having the structure shown in formula (1) includes the following steps:

[0027] The pyridine amine ligand having the structure shown in formula (2) is hydrogenated with sodium borohydride to obtain the pyridine amine ligand having the structure shown in formula (1).

[0028] This invention provides the application of the above-mentioned pyridine amine ligand-scandium complex in the catalytic preparation of polyisobutylene.

[0029] This invention provides a method for the catalytic preparation of polyisobutylene using pyridine amine ligand-scandium complexes, comprising the following steps:

[0030] Isobutylene monomer, pyridine amine ligand-scandium complex, co-catalyst and solvent are mixed and polymerized to obtain polyisobutylene;

[0031] The pyridine amine ligand-scandium complex is the aforementioned pyridine amine ligand-scandium complex.

[0032] Preferably, the co-catalyst comprises a MAO catalyst;

[0033] The molar ratio of the pyridine amine ligand-scandium complex to the cocatalyst is 1:50 to 2000.

[0034] Preferably, the molar ratio of the pyridine amine ligand-scandium complex to the isobutylene monomer is 1:50 to 100000;

[0035] The polymerization reaction is carried out at a temperature of 0–50°C for a duration of 2–12 hours.

[0036] This invention provides a pyridine amine ligand-scandium complex having the structure shown in any one of Formulas I to III. This invention uses a pyridine amine ligand (pyridineimide or pyridineamine) to complex with trivalent scandium. By modifying the ligand skeleton, the structure and reaction rate of polyisobutylene can be better controlled, resulting in better isobutylene polymerization. Compared to existing cationic polymerization methods for preparing polyisobutylene, this invention uses a pyridine amine ligand-scandium complex as a catalyst, enabling isobutylene polymerization at room temperature via coordination polymerization. Example results show that this invention, using a pyridine amine ligand-scandium complex as a catalyst and supplemented with a co-catalyst, can achieve the polymerization reaction of isobutylene at room temperature (25°C) to obtain low molecular weight polyisobutylene. Detailed Implementation

[0037] This invention provides a pyridineamine ligand-scandium complex having the structure shown in any one of Formulas I to III:

[0038]

[0039] In Equations I to III, R 1 It can be a hydrogen atom or a methyl group;

[0040] R 3 It is a hydrogen atom;

[0041] R 2It is a hydrogen atom or the structure shown in any one of Formulas 1 to 11:

[0042]

[0043] X is either Cl or acac.

[0044] In this invention, the pyridineamine ligand-scandium complex preferably has the structure shown in any one of Sc-1 to Sc-5:

[0045]

[0046] This invention provides a method for preparing the above-mentioned pyridineamine ligand-scandium complex, comprising the following steps:

[0047] A soluble trivalent scandium source, pyridine amine ligands, and an organic solvent were mixed and subjected to a complexation reaction to obtain pyridine amine ligand-scandium complexes.

[0048] The soluble trivalent scandium source is ScCl3 or Sc(acac)3;

[0049] The pyridineamine ligand has the structure shown in any one of formulas (1) to (3):

[0050]

[0051] In this invention, the pyridine amine ligands are either commercially available or prepared in-house.

[0052] In this invention, the pyridineamine ligand preferably has the structure shown in any one of Formulas 1 to 15:

[0053]

[0054] In this invention, the method for preparing the pyridineamine ligand having the structure shown in formula (2) preferably includes the following steps:

[0055] Under catalytic conditions, a primary amine having the structure shown in formula a undergoes an amine-aldehyde condensation reaction with a pyridine-2-carboxaldehyde compound having the structure shown in formula b, yielding a pyridineamine ligand having the structure shown in formula (2):

[0056] R 2 -NH2 formula a;

[0057] In this invention, the catalyst is preferably... Molecular sieve.

[0058] In this invention, the amine-aldehyde condensation reaction is preferably carried out under a protective atmosphere, preferably argon. In this invention, the molar ratio of the primary amine having the structure shown in formula a to the pyridine-2-carboxaldehyde compound having the structure shown in formula b is preferably 1:1.

[0059] In this invention, the amine-aldehyde condensation reaction is preferably carried out in an organic solvent, preferably dichloromethane.

[0060] In this invention, the temperature of the amine-aldehyde condensation reaction is preferably 10-40°C, more preferably 20-30°C; and the time is preferably overnight.

[0061] In this invention, after the amine-aldehyde condensation reaction, the resulting amine-aldehyde condensation reaction solution is preferably subjected to post-treatment, which preferably includes the following steps:

[0062] After the reaction of the raw materials was completed as detected by TLC plate, the amine-aldehyde condensation reaction solution was sequentially filtered, column chromatography, evaporated, and dried under vacuum to obtain pyridine amine ligands with the structure shown in formula (2).

[0063] In this invention, the method for preparing the pyridineamine ligand having the structure shown in formula (1) preferably includes the following steps:

[0064] The pyridine amine ligand having the structure shown in formula (2) is hydrogenated with sodium borohydride to obtain the pyridine amine ligand having the structure shown in formula (1);

[0065] In this invention, the molar ratio of the pyridineamine ligand having the structure shown in formula (2) to sodium borohydride is preferably 1:1.

[0066] In this invention, the hydrogenation reaction is preferably carried out in a solvent, preferably methanol.

[0067] In this invention, the temperature of the hydrogenation reaction is preferably 10-40°C, more preferably 20-30°C; and the time is preferably overnight.

[0068] In this invention, after the hydrogenation reaction, the resulting hydrogenation reaction solution is preferably post-treated, and the post-treatment preferably includes the following steps:

[0069] After the reaction of the raw materials was completed as detected by TLC plate, the hydrogenation reaction solution was extracted, the organic phase was collected, and dried to obtain pyridineamine ligands with the structure shown in formula (1).

[0070] In this invention, the extractant used for extraction is preferably an aqueous sodium carbonate solution; the drying is preferably anhydrous sodium sulfate drying.

[0071] In this invention, the pyridineamine ligand having the structure shown in formula (3) is preferably sourced from commercially available sources.

[0072] After obtaining the pyridine amine ligand, the present invention mixes a soluble trivalent scandium source, the pyridine amine ligand, and an organic solvent to carry out a complexation reaction, thereby obtaining a pyridine amine ligand-scandium complex. In the present invention, the soluble trivalent scandium source is ScCl3 or Sc(acac)3. In the present invention, the complexation reaction is preferably carried out in a glove box. In the present invention, the organic solvent is preferably dichloromethane.

[0073] In this invention, the molar ratio of the soluble trivalent scandium source to the pyridine amine ligand is preferably 1:1 to 5, more preferably 1:1.05.

[0074] In this invention, the preferred method of mixing is to dissolve the pyridine amine ligand in an organic solvent and add the resulting solution dropwise to a test tube containing a soluble trivalent scandium source.

[0075] In this invention, the temperature of the complexation reaction is preferably 0-30°C, more preferably 10-25°C, and the time is preferably 12-72h, more preferably 24-48h.

[0076] Following the complexation reaction, the present invention preferably performs post-treatment on the obtained complexation reaction solution, the post-treatment preferably including the following steps:

[0077] The complexation reaction solution was filtered under an argon atmosphere, and the resulting solid was washed and dried to obtain a pyridine amine ligand-scandium complex.

[0078] In this invention, the detergent for washing is preferably n-hexane; the drying method is preferably vacuum drying.

[0079] This invention provides the application of the above-mentioned pyridine amine ligand-scandium complex in the catalytic preparation of polyisobutylene. In this invention, the polyisobutylene is preferably low molecular weight polyisobutylene.

[0080] This invention provides a method for the catalytic preparation of polyisobutylene using pyridine amine ligand-scandium complexes, comprising the following steps:

[0081] Isobutylene monomer, pyridine amine ligand-scandium complex, co-catalyst and solvent are mixed and polymerized to obtain polyisobutylene;

[0082] The pyridine amine ligand-scandium complex is described above.

[0083] In this invention, the molar ratio of the isobutylene monomer to the pyridine amine ligand-scandium complex is preferably 1:400.

[0084] In this invention, the cocatalyst preferably comprises an MAO catalyst. In this invention, the molar ratio of the pyridine amine ligand-scandium complex to the cocatalyst is preferably 1:200. In this invention, the cocatalyst's function is to abstract a chlorine atom from the complex, thereby enhancing the activity of the metal center and making it easier to react with the monomer.

[0085] In this invention, the solvent is preferably anhydrous toluene or n-hexane.

[0086] In this invention, the temperature of the polymerization reaction is preferably 0 to 50°C, more preferably 25°C; the time is preferably 2 to 12 hours, more preferably 5 to 10 hours.

[0087] The following examples illustrate the pyridine amine ligand-scandium complex, its preparation method, and its application in the catalytic preparation of polyisobutylene provided by the present invention. However, these examples should not be construed as limiting the scope of protection of the present invention.

[0088] Example 1

[0089] The preparation of pyridineimine ligands L1 to L8 is carried out using the following steps:

[0090] Add to a 100mL dry reaction flask The molecular sieve was baked for 30 minutes. Under an argon atmosphere, dry dichloromethane, a primary amine (1.0 eq.), and pyridine-2-carboxaldehyde (1.0 eq.) were added sequentially. The reaction was carried out overnight at room temperature, and the reaction was confirmed to be complete by TLC. The mixture was filtered, subjected to column chromatography, evaporated to dryness, and then dried under vacuum to obtain the target ligand.

[0091] The reaction process is as follows:

[0092]

[0093] The primary amines used in L1 through L8 are as follows:

[0094]

[0095] The specific characterization data are as follows:

[0096]

[0097] White solid, 2.5g, yield: 88%. 1H NMR (400MHz, CDCl3, 298K) δ: 8.58-8.57 (d, J = 4.44Hz, 1H), 8.52 (s, 1H), 8.19-8.17 (d, J = 7.92Hz, 1H), 7.66-7.62 (dt, J = 7.6 8Hz, J=0.96Hz, 1H), 7.39-7.38 (d, J=7.40Hz, 4H), 7.31-7.27 (t, J=7.36Hz, 4H), 7.22-7.18 (t, J=7.36Hz, 3H), 5.68 (s, 1H); 13 C NMR (100MHz, CDCl3, 298K), δ: 161.8, 154.5, 149.1, 143.1, 136.2, 128.3, 127.5, 126.9, 124.6, 121.3, 77.5.

[0098]

[0099] Colorless liquid, 1.8g, yield: 90%. 1 H NMR (400MHz, CDCl3, 298K) δ: 8.65-8.63 (m, 1H), 8.49 (s, 1H), 8.20-8.18 (d, J = 7.92Hz, 1H), 7.78-7.74(dt,J=1.24Hz,J=7.6Hz,1H),7.34-7.30(m,5H),7.04-6.99(m,4H),5.65(s,1H); 13 C NMR (100MHz, CDCl3, 298K) δ163.1,162.1,160.7,154.4,149.4,138.9,138.8,136.5,129.2,129.12,125.0,121.5,115.4,115.2,76.0.

[0100]

[0101] Colorless liquid, 0.6 g, yield: 68%; 1 H NMR (400MHz, CDCl3, 298K) δ8.63-8.62(m,1H),8.47(s,1H),8.21-8.19(d,J=7.92Hz,1H),7.76-7. 71(dt,J=1.40Hz,J=7.64Hz,1H),7.32-7.25(m,5H),6.87-6.84(m,4H),5.62(s,1H),3.78(s,6H); 13C NMR (100MHz, CDCl3, 298K) δ161.4,158.6,154.8,149.3,136.4,135.7,128.7,124.7,121.4,113.8,55.2.

[0102]

[0103] White solid, 2.52 g, yield: 83%. 1 H NMR (400MHz, CDCl3, 298K) δ: 8.64-8.63 (d, J = 4.44Hz, 1H), 8.10 (s, 1H), 8.08-8.06 (d, J = 7.88Hz, 1H), 7.7 4-7.70(d,J=7.32Hz,1H),7.45-7.07(m,11H),4.59-4.55(t,J=6.80Hz,1H),3.25-3.23(d,J=6.88Hz,2H); 13 C NMR (100MHz, CDCl3, 298K) δ: 161.0, 154.4, 149.1, 143.2, 138.4, 136.3, 129.6, 128.3, 128.0, 127.0, 126.1, 124.5, 121.3, 76.8, 45.3.

[0104]

[0105] 1.40g of light yellow liquid was produced, with a yield of 85%. 1 H NMR (400MHz, CDCl3, 298K) δ: 8.75-8.69 (m, 1H), 8.61 (s, 1H), 8.21 (d, J = 8.0Hz, 1H), 7.84-7.80 (m, 1H), 7.46-7.35 (m, 3H), 7.31-7.27 (m, 3H); 13 C NMR (100MHz, CDCl3, 298K) δ160.6,154.5,150.9,149.6,136.7,129.2,126.7,125.1,121.9,121.1.

[0106]

[0107] Yellow liquid, 2.5g, yield: 68%. 1H NMR (400MHz, CDCl3, 298K) δ: 8.64-8.63 (m, 1H), 8.49 (s, 1H), 8.06 (d, J = 7.6Hz, 1H), 7.74-7.69 (m, 1H), 7.74-7.69 (m, 6H), 4.87 (s, 2H); 13 CNMR (100MHz, CDCl3, 298K) δ: 162.88, 154.61, 149.47, 138.76, 136.59, 128.63, 128.23, 127.22, 124.87, 121.40, 77.48, 77.16, 76.84, 64.98.

[0108]

[0109] Colorless liquid: 1.8g, yield: 80%. 1 H NMR (400MHz, CDCl3, 298K) δ: 8.63-8.60 (m, 1H), 8.34 (s, 1H), 8.12 (d, J = 8.0Hz, 1H), 7.73-7.6 7(m,1H),7.43(dd,J=8.4,1.0Hz,2H),7.33(t,J=7.8Hz,2H),7.28-7.19(m,2H),1.67(s,6H). 13 C NMR (100MHz, CDCl3, 298K) δ: 158.2, 155.3, 149.2, 147.5, 136.4, 128.2, 126.4, 126.0, 124.55, 121.0, 63.0, 29.5.

[0110]

[0111] Colorless liquid, 0.78 g, yield: 73%. 1 H NMR(400MHz,,CDCl3,298K)δ:8.63(d,J=4.6Hz,1H),8.33(s,1H),8.04(d,J=8.0Hz,1H),7.73(td,J=7.8, 1.6Hz, 1H), 7.29 (ddd, J=7.4, 5.0, 1.4Hz, 1H), 1.65 (q, J=7.6Hz, 2H), 1.26 (s, 6H), 0.85 (t, J=7.6Hz, 3H). 13 C NMR (100MHz, CDCl3, 298K) δ: 156.9, 155.7, 149.3, 136.6, 124.4, 120.9, 60.3, 35.8, 26.6, 8.7.

[0112] Example 2

[0113] The preparation of pyridineamine ligands L9–L14 is carried out using the following steps:

[0114] Add to a 100mL dry reaction flask Molecular sieves were baked for 30 minutes. Under an argon atmosphere, dry dichloromethane, primary amine (1.0 eq.), and pyridine-2-carboxaldehyde (1.0 eq.) were added sequentially, and the reaction was monitored by TLC until the starting material was completely reacted. The mixture was filtered, evaporated to dryness, and then dried under vacuum to obtain pyridineimide. Then, methanol, pyridineimide (1.0 eq.), and sodium borohydride (10.0 eq.) were added sequentially to a 100 mL two-necked flask, and the mixture was stirred overnight at room temperature, and the reaction was monitored by TLC until the starting material was completely reacted. After quenching the reaction with sodium carbonate aqueous solution, the mixture was extracted with DCM, the organic phase was collected, and concentrated to obtain the crude product of the target ligand. The crude product was then purified by column chromatography to obtain the pyridineimide ligand.

[0115] The structural formula of the primary amine used is as follows:

[0116]

[0117] Pale yellow liquid, 1.01 g, yield: 62%. 1 H NMR (400MHz, CDCl3, 298K) δ: 8.61-8.52 (m, 1H), 7.63 (td, J = 7.8, 1.8Hz, 1H), 7.39-7.29 ( m,5H),7.24(d,J=6.8Hz,1H),7.18-7.13(m,1H),3.93(s,2H),3.84(s,2H),2.19(s,1H). 13 C NMR (100MHz, CDCl3, 298K) δ: 159.9, 149.4, 140.2, 136.5, 128.5, 128.4, 127.1, 122.4, 122.0, 54.6, 53.6.

[0118]

[0119] Pale yellow liquid, 0.64 g, yield: 69%. 1 H NMR (400MHz, CDCl3, 298K) δ:8.59-8.53(m,1H),7.65(td,J=7.6,1.8Hz,1H),7.38(d,J=7.8H z,1H),7.19-7.12(m,1H),6.83(s,2H),3.99(s,2H),3.77(s,2H),2.33(s,6H),2.24(s,3H). 13C NMR (100MHz, CDCl3, 298K) δ: 160.3, 149.3, 137.2, 136.6, 136.5, 133.6, 129.1, 122.5, 122.0, 55.6, 47.3, 21.0, 19.6.

[0120]

[0121] Pale yellow liquid, 0.93g, yield: 80%. 1 H NMR (400MHz, CDCl3, 298K) δ: 8.57 (dt, J=5.0, 1.4Hz, 1H), 7.64 (td, J=7.6, 1.8Hz, 1H), 7.58 (d, J=8.0Hz ,2H),7.49(d,J=8.0Hz,2H),7.29(d,J=7.8Hz,1H),7.17(m,1H),3.92(s,2H),3.91(s,2H),2.13(s,1H). 13 C NMR (100MHz, CDCl3, 298K) δ: 159.5, 149.5, 144.4, 136.6, 129.4, 128.5, 125.4, 124.4, 122.5, 122.2, 54.6, 53.1.

[0122]

[0123] Pale yellow liquid, 0.31 g, yield: 91%. 1 H NMR (400MHz, CDCl3, 298K) δ: 8.59-8.51 (m, 1H), 7.64 (tt, J = 7.6, 1.8Hz, 1H), 7.35-7.19 (m, 3H), 7.15 (ddd,J=7.6,4.8,1.2Hz,1H),6.92-6.81(m,2H),3.91(s,2H),3.79(s,3H),3.78(s,2H),2.14(s,1H). 13 C NMR (100MHz, CDCl3, 298K) δ: 159.9, 158.8, 149.4, 136.5, 132.4, 129.6, 122.5, 122.0, 113.9, 55.4, 54.6, 53.0.

[0124]

[0125] Pale yellow liquid, 1.45g, yield: 80%. 1H NMR (400MHz, CDCl3, 298K) δ: 8.59 (ddd, J=4.9, 1.7, 0.9Hz, 1H), 7.64 (td, J=7.7, 1.8Hz, 1H ),7.34(d,J=7.9Hz,1H),7.24-7.14(m,3H),6.77-6.64(m,3H),4.76(s,1H),4.47(s,2H). 13 C NMR (100MHz, CDCl3, 298K) δ: 158.6, 149.3, 148.0, 136.7, 129.3, 122.2, 121.7, 117.7, 113.1, 49.4.

[0126]

[0127] Pale yellow liquid, 1.51g, yield: 74%. 1 H NMR (400MHz, CDCl3, 298K) δ: 8.54 (ddd, J=4.8, 1.8, 1.0Hz, 1H), 7.61 (td, J=7.6, 1.8Hz, 1H), 7.47-7.40 (m, 4H), 7.33-7.25(m,5H),7.23-7.17(m,2H),7.14(ddd,J=7.6,4.8,1.2Hz,1H),4.87(s,1H),3.87(s,2H),2.52(s,1H). 13 CNMR (100MHz, CDCl3, 298K) δ: 159.8, 149.4, 143.9, 136.4, 128.6, 127.5, 127.1, 122.6, 122.0, 67.1, 53.5.

[0128] The pyridineamine ligand L15 is commercially available.

[0129] L15.

[0130] Example 3

[0131] The preparation process of pyridine amine ligand-scandium complex involves the following steps:

[0132] In a glove box, anhydrous ScCl3 (1.0 eq.) and dichloromethane (8 mL) were added sequentially to a dry Schlenk tube (50 mL). The pyridine amine ligands from Examples 1-2 (1.05 eq.) were dissolved in dichloromethane (10 mL) and added dropwise to the ScCl3-containing Schlenk tube with stirring. The mixture was stirred at room temperature for 48 hours. After the reaction was complete, the mixture was filtered under an argon atmosphere, and the filtrate or solid was collected, dried under vacuum, and then the solid was washed three times with n-hexane and dried under vacuum to obtain the target complexes, designated Sc-1 to Sc-15.

[0133] The structural characterization of the obtained pyridineamine ligand-scandium complex is as follows:

[0134] Sc-1

[0135] HRMS-ESI(m / z)::Calcd for[C 19 H 16 Cl2ScN2]:387.0250; Found 387.0249;

[0136] ATR-IR (cm) -1 ):1596,1495,1454,1308,1268,1230,1156,1085,1019,1005,991,928,864,822,796,766,741.

[0137] Sc-2

[0138] HRMS-ESI(m / z):Calcd for [C 19 H 14 Cl2F2ScN2] + :423.0061; Found:423.0058;

[0139] ATR-IR (cm) -1 ):1598,1507,1443,1414,1308,1227,1159,1103,1052,1018,967,910,863,839,788,767,745.

[0140] Sc-3

[0141] HRMS-ESI(m / z):Calcd for [C 21 H 20 Cl2ScN2O2] + :447.0461; Found:447.0460;

[0142] ATR-IR(cm -1 ):1608,1510,1463,1442,1306,1250,1177,1115,1029,907,836,818,784,767,748.

[0143] Sc-4

[0144] HRMS-ESI(m / z):Calcd for[C 21 H 21 Cl2ScN2] + :416.0461;Found:416.0460;

[0145] ATR-IR(cm -1 ):1593,1492,1443,1366,1306,1265,1219,1160,1024,979,921,906,773,753,728.

[0146] Sc-9

[0147] HRMS-ESI(m / z):Calcd for[C 13 H 14 Cl2ScN2] + :523.1119;Found:523.1122;

[0148] ATR-IR(cm -1 ):3250,3026,2942,1605,1571,1488,1442,1335,1306,1149,1088,1021,995,912,880,765.

[0149] Sc-10

[0150] HRMS-ESI(m / z):Calcd for[C 16 H 20 Cl2ScN2] + :355.0563;Found,355.0562;

[0151] ATR-IR(cm -1 ):3290,2979,2948,1608,1573,1486,1441,1363,1312,1151,1080,1051,1022,981,894,869,813,761.

[0152] Sc-11

[0153] HRMS-ESI(m / z):Calcd for [C 14 H 13 Cl2F3ScN2] + :380.9967; Found:380.9966;

[0154] ATR-IR (cm) -1 ):3251,2941,1606,1571,1436,1329,1164,1115,1066,1020,986,900,815,765.

[0155] Sc-12

[0156] HRMS-ESI(m / z):Calcd for [C 14 H 16 Cl2ScN2O] + :343.0199; Found:343.0199;

[0157] ATR-IR (cm) -1 ):3249,2939,2836,2354,1698,1610,1572,1513,1486,1441,1324,1301,1251,1180,1050,1032,994,899,815,765.

[0158] Application Example 1

[0159] Under an argon atmosphere, scandium complex Sc-5 (10 μmol, 1 equiv.), anhydrous toluene, co-catalyst MAO (2 mmol, 200 equiv., 1.5 M toluene solution, purchased from Aladdin), and isobutylene (4 mmol, 400 equiv.) were added sequentially to a 25 mL Schlenk flask. The system was placed at 25 °C and reacted for 12 h. The reaction was quenched with methanol, washed with methanol, filtered, and vacuum dried to obtain a colorless viscous polymer, namely low molecular weight polyisobutylene.

[0160] In this embodiment, the yield of low molecular weight polyisobutylene was 42%, the molecular weight was 2729 g / mol, and the PDI was 2.3.

[0161] Application Example 2

[0162] Under an argon atmosphere, scandium complex Sc-1 (10 μmol, 1 equiv.), anhydrous toluene, co-catalyst MAO (2 mmol, 200 equiv., 1.5 M toluene solution), and isobutylene (4 mmol, 400 equiv.) were added sequentially to a 25 mL Schlenk flask. The system was placed at 25 °C and reacted for 12 h. The reaction was quenched with methanol, washed with methanol, filtered, and vacuum dried to obtain a colorless viscous polymer, namely low molecular weight polyisobutylene.

[0163] In this embodiment, the yield of low molecular weight polyisobutylene was 50%, the molecular weight was 3257 g / mol, and the PDI was 2.4.

[0164] Application Example 3

[0165] Under an argon atmosphere, scandium complex Sc-2 (10 μmol, 1 equiv.), anhydrous toluene, co-catalyst MAO (2 mmol, 200 equiv., 1.5 M toluene solution), and isobutylene (4 mmol, 400 equiv.) were added sequentially to a 25 mL Schlenk flask. The system was placed at 25 °C and reacted for 12 h. The reaction was quenched with methanol, washed with methanol, filtered, and vacuum dried to obtain a colorless viscous polymer, namely low molecular weight polyisobutylene.

[0166] In this embodiment, the yield of low molecular weight polyisobutylene was 47%, the molecular weight was 2209 g / mol, and the PDI was 2.3.

[0167] Application Example 4

[0168] Under an argon atmosphere, scandium complex Sc-3 (10 μmol, 1 equiv.), anhydrous toluene, co-catalyst MAO (2 mmol, 200 equiv., 1.5 M toluene solution), and isobutylene (4 mmol, 400 equiv.) were added sequentially to a 25 mL Schlenk flask. The system was placed at 25 °C and reacted for 12 h. The reaction was quenched with methanol, washed with methanol, filtered, and vacuum dried to obtain a colorless viscous polymer, namely low molecular weight polyisobutylene.

[0169] In this embodiment, the yield of low molecular weight polyisobutylene was 62%, the molecular weight was 3659 g / mol, and the PDI was 2.4.

[0170] Application Example 5

[0171] Under an argon atmosphere, scandium complex Sc-4 (10 μmol, 1 equiv.), anhydrous toluene, co-catalyst MAO (2 mmol, 200 equiv., 1.5 M toluene solution), and isobutylene (4 mmol, 400 equiv.) were added sequentially to a 25 mL Schlenk flask. The system was placed at 25 °C and reacted for 12 h. The reaction was quenched with methanol, washed with methanol, filtered, and vacuum dried to obtain a colorless viscous polymer, namely low molecular weight polyisobutylene.

[0172] In this embodiment, the yield of low molecular weight polyisobutylene was 69%, the molecular weight was 2003 g / mol, and the PDI was 2.5.

[0173] Application Example 6

[0174] Under an argon atmosphere, scandium complex Sc-6 (10 μmol, 1 equiv.), anhydrous toluene, co-catalyst MAO (2 mmol, 200 equiv., 1.5 M toluene solution), and isobutylene (4 mmol, 400 equiv.) were added sequentially to a 25 mL Schlenk flask. The system was placed at 25 °C and reacted for 12 h. The reaction was quenched with methanol, washed with methanol, filtered, and vacuum dried to obtain a colorless viscous polymer, namely low molecular weight polyisobutylene.

[0175] In this embodiment, the yield of low molecular weight polyisobutylene was 38%, the molecular weight was 2637 g / mol, and the PDI was 2.5.

[0176] Application Example 7

[0177] Under an argon atmosphere, scandium complex Sc-7 (10 μmol, 1 equiv.), anhydrous toluene, co-catalyst MAO (2 mmol, 200 equiv., 1.5 M toluene solution), and isobutylene (4 mmol, 400 equiv.) were added sequentially to a 25 mL Schlenk flask. The system was placed at 25 °C and reacted for 12 h. The reaction was quenched with methanol, washed with methanol, filtered, and vacuum dried to obtain a colorless viscous polymer, namely low molecular weight polyisobutylene.

[0178] In this embodiment, the yield of low molecular weight polyisobutylene was 33%, the molecular weight was 2519 g / mol, and the PDI was 2.5.

[0179] Application Example 8

[0180] Under an argon atmosphere, scandium complex Sc-8 (10 μmol, 1 equiv.), anhydrous toluene, co-catalyst MAO (2 mmol, 200 equiv., 1.5 M toluene solution), and isobutylene (4 mmol, 400 equiv.) were added sequentially to a 25 mL Schlenk flask. The system was placed at 25 °C and reacted for 12 h. The reaction was quenched with methanol, washed with methanol, filtered, and vacuum dried to obtain a colorless viscous polymer, namely low molecular weight polyisobutylene.

[0181] In this embodiment, the yield of low molecular weight polyisobutylene was 33%, the molecular weight was 2519 g / mol, and the PDI was 2.5.

[0182] Application Example 9

[0183] Under an argon atmosphere, scandium complex Sc-9 (10 μmol, 1 equiv.), anhydrous toluene, co-catalyst MAO (2 mmol, 200 equiv., 1.5 M toluene solution), and isobutylene (4 mmol, 400 equiv.) were added sequentially to a 25 mL Schlenk flask. The system was placed at 25 °C and reacted for 12 h. The reaction was quenched with methanol, washed with methanol, filtered, and vacuum dried to obtain a colorless viscous polymer, namely low molecular weight polyisobutylene.

[0184] In this embodiment, the yield of low molecular weight polyisobutylene was 46%, the molecular weight was 2990 g / mol, and the PDI was 2.5.

[0185] Application Example 10

[0186] Under an argon atmosphere, scandium complex Sc-10 (10 μmol, 1 equiv.), anhydrous toluene, co-catalyst MAO (2 mmol, 200 equiv., 1.5 M toluene solution), and isobutylene (4 mmol, 400 equiv.) were added sequentially to a 25 mL Schlenk flask. The system was placed at 25 °C and reacted for 12 h. The reaction was quenched with methanol, washed with methanol, filtered, and vacuum dried to obtain a colorless viscous polymer, namely low molecular weight polyisobutylene.

[0187] In this embodiment, the yield of low molecular weight polyisobutylene was 34%, the molecular weight was 2856 g / mol, and the PDI was 2.6.

[0188] Application Example 11

[0189] Under an argon atmosphere, scandium complex Sc-11 (10 μmol, 1 equiv.), anhydrous toluene, co-catalyst MAO (2 mmol, 200 equiv., 1.5 M toluene solution), and isobutylene (4 mmol, 400 equiv.) were added sequentially to a 25 mL Schlenk flask. The system was placed at 25 °C and reacted for 12 h. The reaction was quenched with methanol, washed with methanol, filtered, and vacuum dried to obtain a colorless viscous polymer, namely low molecular weight polyisobutylene.

[0190] In this embodiment, the yield of low molecular weight polyisobutylene was 39%, the molecular weight was 2900 g / mol, and the PDI was 2.7.

[0191] Application Example 12

[0192] Under an argon atmosphere, scandium complex Sc-12 (10 μmol, 1 equiv.), anhydrous toluene, co-catalyst MAO (2 mmol, 200 equiv., 1.5 M toluene solution), and isobutylene (4 mmol, 400 equiv.) were added sequentially to a 25 mL Schlenk flask. The system was placed at 25 °C and reacted for 12 h. The reaction was quenched with methanol, washed with methanol, filtered, and vacuum dried to obtain a colorless viscous polymer, namely low molecular weight polyisobutylene.

[0193] In this embodiment, the yield of low molecular weight polyisobutylene was 33%, the molecular weight was 3952 g / mol, and the PDI was 3.0.

[0194] Application Example 13

[0195] Under an argon atmosphere, scandium complex Sc-13 (10 μmol, 1 equiv.), anhydrous toluene, co-catalyst MAO (2 mmol, 200 equiv., 1.5 M toluene solution), and isobutylene (4 mmol, 400 equiv.) were added sequentially to a 25 mL Schlenk flask. The system was placed at 25 °C and reacted for 12 h. The reaction was quenched with methanol, washed with methanol, filtered, and vacuum dried to obtain a colorless viscous polymer, namely low molecular weight polyisobutylene.

[0196] In this embodiment, the yield of low molecular weight polyisobutylene was 29%, the molecular weight was 3620 g / mol, and the PDI was 2.7.

[0197] Application Example 14

[0198] Under an argon atmosphere, scandium complex Sc-14 (10 μmol, 1 equiv.), anhydrous toluene, co-catalyst MAO (2 mmol, 200 equiv., 1.5 M toluene solution), and isobutylene (4 mmol, 400 equiv.) were added sequentially to a 25 mL Schlenk flask. The system was placed at 25 °C and reacted for 12 h. The reaction was quenched with methanol, washed with methanol, filtered, and vacuum dried to obtain a colorless viscous polymer, namely low molecular weight polyisobutylene.

[0199] In this embodiment, the yield of low molecular weight polyisobutylene was 30%, the molecular weight was 3853 g / mol, and the PDI was 2.4.

[0200] Application Example 15

[0201] Under an argon atmosphere, scandium complex Sc-15 (10 μmol, 1 equiv.), anhydrous toluene, co-catalyst MAO (2 mmol, 200 equiv., 1.5 M toluene solution), and isobutylene (4 mmol, 400 equiv.) were added sequentially to a 25 mL Schlenk flask. The system was placed at 25 °C and reacted for 12 h. The reaction was quenched with methanol, washed with methanol, filtered, and vacuum dried to obtain a colorless viscous polymer, namely low molecular weight polyisobutylene.

[0202] In this embodiment, the yield of low molecular weight polyisobutylene was 60%, the molecular weight was 5853 g / mol, and the PDI was 2.7.

[0203] Comparative Example 1

[0204] Under an argon atmosphere, scandium complex Sc-5 (10 μmol, 1 equiv.), anhydrous toluene, and isobutylene (4 mmol, 400 equiv.) were added sequentially to a 25 mL Schlenk flask. The system was placed at 25 °C and reacted for 12 h. The reaction was quenched with methanol, washed with methanol, filtered, and vacuum dried. No polyisobutylene was produced.

[0205] Comparative Example 2

[0206] Under an argon atmosphere, scandium complex Sc-5 (10 μmol, 1 equiv.), anhydrous toluene, co-catalyst AlMe3 (2 mmol, 200 equiv., 1.5 M toluene solution), and isobutylene (4 mmol, 400 equiv.) were added sequentially to a 25 mL Schlenk flask. The system was placed at 25 °C and reacted for 12 h. The reaction was quenched with methanol, washed with methanol, filtered, and vacuum dried. No polyisobutylene was produced.

[0207] Comparative Example 3

[0208] Under an argon atmosphere, scandium complex Sc-5 (10 μmol, 1 equiv.), anhydrous toluene, co-catalyst AlEt3 (2 mmol, 200 equiv., 1.5 M toluene solution), and isobutylene (4 mmol, 400 equiv.) were added sequentially to a 25 mL Schlenk flask. The system was placed at 25 °C and reacted for 12 h. The reaction was quenched with methanol, washed with methanol, filtered, and vacuum dried. No polyisobutylene was produced.

[0209] Comparative Example 4

[0210] Under an argon atmosphere, scandium complex Sc-5 (10 μmol, 1 equiv.), anhydrous toluene, co-catalyst Ali-Bu3 (2 mmol, 200 equiv., 1.5 M toluene solution), and isobutylene (4 mmol, 400 equiv.) were added sequentially to a 25 mL Schlenk flask. The system was placed at 25 °C and reacted for 12 h. The reaction was quenched with methanol, and after washing with methanol, filtration, and vacuum drying, no polyisobutylene was produced.

[0211] Comparative Examples 2-4 show that the co-catalysts AlMe3, AlEt3, and Ali-Bu3 cannot remove chlorine from the metal complex to form an active metal center.

[0212] Comparative Example 5

[0213] In an argon atmosphere, anhydrous toluene, co-catalyst MAO (2 mmol, 200 equiv., 1.5 M toluene solution), and isobutylene (4 mmol, 400 equiv.) were placed in a 25 mL Schlenk flask and reacted at 25 °C for 12 h. The reaction was quenched with methanol, washed with methanol, filtered, and vacuum dried. No polyisobutylene was produced.

[0214] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A pyridineamine ligand-scandium complex having the structure shown in any one of Formulas I to III: Formula I; Formula II; Formula III; In formulae I to III, R 1 is a hydrogen atom or a methyl group; R 3 is a hydrogen atom; R 2 is any one of the structures shown in Formulas 1-4, 6-11: ； X is either Cl or acac.

2. A pyridineamine ligand-scandium complex having any one of the following structures: 。 3. The method for preparing the pyridineamine ligand-scandium complex according to claim 1 or 2, comprising the following steps: A soluble trivalent scandium source, pyridine amine ligands, and an organic solvent were mixed and subjected to a complexation reaction to obtain pyridine amine ligand-scandium complexes. The soluble trivalent scandium source is ScCl3 or Sc(acac)3; The pyridineamine ligands have the structures shown in any one of formulas (1) to (3): Formula (1); Formula (2); Equation (3).

4. The preparation method according to claim 3, characterized in that, The complexation reaction is carried out at a temperature of 0~30℃ for a time of 12~72h.

5. The preparation method according to claim 3, characterized in that, The molar ratio of the soluble trivalent scandium source to the pyridine amine ligand is 1:1~5.

6. The preparation method according to claim 3, characterized in that, The method for preparing the pyridineamine ligand having the structure shown in formula (2) includes the following steps: In the presence of a catalyst, a primary amine having the structure shown in formula a undergoes an amine-aldehyde condensation reaction with a pyridine-2-carboxaldehyde compound having the structure shown in formula b to obtain a pyridine amine ligand having the structure shown in formula (2). Formula a; Formula b; The method for preparing the pyridineamine ligand having the structure shown in formula (1) includes the following steps: The pyridine amine ligand having the structure shown in formula (2) is hydrogenated with sodium borohydride to obtain the pyridine amine ligand having the structure shown in formula (1).

7. The application of the pyridine amine ligand-scandium complex according to claim 1 or 2, or the pyridine amine ligand-scandium complex prepared by any one of claims 3 to 6, in the catalytic preparation of polyisobutylene.

8. A method for preparing polyisobutylene catalyzed by a pyridine amine ligand-scandium complex, comprising the following steps: Isobutylene monomer, pyridine amine ligand-scandium complex, co-catalyst and solvent are mixed and polymerized to obtain polyisobutylene; the co-catalyst includes MAO catalyst; The pyridine amine ligand-scandium complex is the pyridine amine ligand-scandium complex according to claim 1 or 2, or the pyridine amine ligand-scandium complex prepared by any one of the preparation methods according to claims 3 to 6.

9. The method according to claim 8, characterized in that, The molar ratio of the pyridine amine ligand-scandium complex to the cocatalyst is 1:50~2000.

10. The method according to claim 8 or 9, characterized in that, The molar ratio of the pyridine amine ligand-scandium complex to the isobutylene monomer is 1:50~100000; The polymerization reaction is carried out at a temperature of 0~50℃ for 2~12 hours.

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