Preparation method and application of N, O-type nickel olefin polymerization catalyst based on alpha-imine indolone

Abstract

The invention discloses a preparation method and application of an N, O-type nickel olefin polymerization catalyst based on alpha-imine indolone. The invention provides a novel N, O-type nickel olefin polymerization catalyst based on alpha-imine indolone, and the novel N, O-type nickel olefin polymerization catalyst, an alpha-imine group-Ar near a metal center and indole N-R at a far end form a steric hindrance effect together to adjust the polymerization performance of the nickel catalyst. A nickel complex of the nickel catalyst can initiate homogeneous polymerization of olefin such as ethylene in a single component mode, a metal active center is effectively protected through a large-steric-hindrance group, the thermal stability of the nickel catalyst and the activity of catalyzing ethylene are greatly improved, and a low-branched polyolefin material with excellent mechanical and elastic properties is prepared. The molecular weight, branched chain density, melting point and other parameters of the obtained polyethylene material are all adjustable. The N, O-type innovative catalyst opens up a brand new path for the development of a polyolefin catalyst family, and provides a precious choice.

Description

Technical Field

[0001] The invention relates to olefin polymerization, in particular to a novel indole ketimine nickel complex, a preparation method and application thereof in olefin polymerization. Background Art

[0002] As one of the most widely produced commodity materials, polyolefins are widely used in many fields due to their versatility. To meet the challenges of early transition metal catalysts, late transition metal catalysts, especially cheap nickel catalysts, have attracted a lot of attention from industry and academic research due to their abundant natural reserves and low cost. Over the past half century, transition metal nickel-catalyzed ethylene polymerization has attracted much attention from the global scientific community. This field has undergone remarkable development, and various types of nickel catalyst systems have emerged one after another, among which N,N-type, N,O-type and P,O-type nickel systems are particularly eye-catching. These new catalysts not only enrich our understanding of nickel catalytic mechanisms in theory, but also show great potential in practical applications, promoting the progress of polymer materials science. Through continuous optimization and innovation, these nickel catalyst systems are gradually becoming important tools in modern chemical production, providing new solutions to challenges in the fields of energy, environment and materials. At present, a large number of Ni(II)-based catalysts have been reported to produce high molecular weight polyolefins, such as α-diimine, phosphine sulfonate, pyridine imine, ketone imine, salicylic imine and α-imine formamide. In 1995, Brookhart discovered the pioneering work of α-diimine nickel catalyst (J. Johnson, C. Killian, M. Brookhart, New Pd(II) and Ni(II) based catalysts for polymerization of ethylene and α-olefins. J. Am. Chem. Soc. 1995, 117(23): 6414-6415), which can produce high molecular weight polyethylene with activity comparable to that of early transition metal catalysts. In 2000, Grubbs first published salicylaldehyde imine neutral nickel catalyst (II), which is another important progress in this field (T. R. Younkin, E. F. Connor, J. I. Henderson, S. K. Friedrich, R. H. Grubbs, D. A. Bansleben, Neutral, Single-Component Nickel(II) Polyolefin Catalysts That Tolerate Heteroatoms, Science 2000, 287, 460-462).Recently, our team has developed a new type of sterically hindered pyridine carboxamidate nickel catalyst, which exhibits high activity and good thermal stability in catalytic ethylene polymerization. The resulting high molecular weight polymer (P.Li, H.Liu, W.Tian, ​​Z.Ma, X.Wang, G.Xu, C.Li, M.Qasim, F.Wang, Steric and electronic effects in cationic pyridine carboxamidatenickel mediated ethylene polymerization and copolymerization with methyl 10-undecenoate, Polymer 2023, 280, 126060) is also suitable for copolymerization of ethylene with polar monomers. This is mainly because N,O-type nickel catalysts have stable structures, convenient synthesis, single-component catalytic polymerization, and stronger tolerance to polar functional groups. Recently, a lot of research work has focused on the design and development of N,O-based nickel catalysts, partly due to their potential to produce polar functionalized polyolefins during copolymerization.

[0003] Continuously improving the catalyst structure is the key to developing new and efficient polyolefin metal catalysts. Literature survey shows that nickel catalysts based on indolone imines have not been reported. Based on this, the present invention designs a preparation method and application of an α-iminoindolone N,O-type nickel olefin polymerization catalyst to fill the gap in the field of nickel catalysts based on indolone imines. Summary of the invention

[0004] Purpose of the invention: The purpose of the present invention is to provide a novel α-imidoindolone ligand and its nickel complex, the obtained complex has good thermal stability, high catalytic activity for olefin polymerization, and the obtained polymer has a high molecular weight.

[0005] Technical solution: A N,O-type α-imidoindolone ligand, the general structural formula L of which is shown below:

[0006]

[0007] Wherein, in the general formula, Ar is selected from one of differently substituted phenyl, naphthyl, and anthracenyl; R is selected from one of C1-C20 alkyl, differently substituted phenyl, benzyl, naphthyl, and triarylmethyl.

[0008] Preferably, the bulky hindered N,O-type α-imidoindolone ligand has a ligand structure of one of L1-L5:

[0009]

[0010] The present invention also provides a method for preparing a differently substituted N,O-type α-iminoindolone ligand: under nitrogen or argon, using α,β-indolequinone as a basic reaction raw material, installing different sterically hindered substituent groups R on indole-NH through a substitution reaction, and further introducing different imine substituent groups Ar at the α-position of indolequinone through a condensation reaction to obtain a dual-site driven α-iminoindolone ligand; wherein Ar is selected from one of differently substituted phenyl, naphthyl, and anthracene; and R is selected from one of a C1-C20 alkyl group, a differently substituted phenyl, a benzyl group, a naphthyl group, and a triarylmethyl group.

[0011] The present invention also provides an N,O-type α-imidoindolone nickel complex, the general structural formula C of which is shown below:

[0012]

[0013] Wherein, in the general formula, Ar is selected from one of phenyl, naphthyl and anthracenyl with different substitutions; R is selected from one of C1-C20 alkyl, phenyl with different substitutions, benzyl, naphthyl and triarylmethyl; represents tetrakis(3,5-bis(trifluoromethyl)phenyl)borate anion, connected to Ni It represents allyl.

[0014] Preferably, in the general structural formula of the N,O-type α-imidoindolone nickel complex, Ar is phenyl, benzyl, or trityl; R is 2,6-diisopropylphenyl, 2,6-bis(diphenylmethyl), or 8-toluene-substituted naphthylamino, and the ligand structural formula is one of Ni1-Ni5:

[0015]

[0016] The present invention also provides a method for preparing an N,O-type α-imidoindolone nickel complex: under an argon or nitrogen atmosphere, dissolving an α-imidoindolone ligand in a good solvent to obtain a ligand solution; dissolving sodium tetrakis(3,5-bis(trifluoromethyl)phenyl)borate (NaBAF) and a metal nickel precursor in a good solvent to obtain a metal nickel precursor solution, then adding the ligand solution to the metal nickel precursor solution, reacting at room temperature, and removing the solvent to obtain the nickel complex.

[0017] Preferably, the metallic nickel precursor is allyl nickel chloride [Ni(allyl)Cl] 2 ; The good solvent is one or a mixture of toluene, dichloromethane, chloroform, dichlorobenzene, trichlorobenzene; the reaction time is 1-12h.

[0018] Preferably, the formula for preparing N,O-type α-imidoindolone nickel complex Ni1-Ni3 is as follows:

[0019]

[0020] The invention also provides an application of an N,O-type α-imidoindolone nickel complex as a catalyst for olefin polymerization.

[0021] Preferably, the polymerization reaction is carried out in an anhydrous and oxygen-free organic solvent, the amount of nickel complex used is 1 to 30 μmol / L, the polymerization pressure is 0.1 to 50 MPa, the reaction temperature is controlled to be 0 to 200°C, and the reaction time is 0.05 to 8.00 hours; the polymerization reaction is an ethylene / propylene homopolymerization reaction or a copolymerization reaction with a polar monomer.

[0022] Preferably, the organic solvent is a mixture of one or more of toluene, hexane, n-heptane and chlorobenzene.

[0023] Preferably, the polar monomer is a C2-C20 α-olefin containing a polar group, or a cycloolefin containing a polar group; the polar group is an organic functional group containing oxygen, nitrogen, sulfur or selenium.

[0024] Preferably, the polar group includes a hydroxyl group, a carboxyl group, an ester group, an alkoxy group, a keto group, an amine group, an amide group, a thioether, a silyl ether or a selenoether.

[0025] Preferably, the polymerization reaction method includes one of slurry polymerization, loop polymerization and gas phase polymerization.

[0026] Beneficial effects: The present invention uses α, β-indolequinone as the basic reaction raw material, installs different sterically hindered substituent groups on indole-NH through substitution reaction, and further introduces different imine substituent groups at the α-position of α, β-indolequinone through condensation reaction. The ligand of this type of α-iminoindolone reacts with the nickel precursor to obtain a new type of N, O-type catalyst. Together with the α-imine group -Ar near the metal center and the indole NR at the far end, the steric hindrance around the metal is increased to adjust the polymerization performance of the nickel catalyst. The catalyst regulates the electron cloud density of the metal center by adjusting the steric hindrance effect, improves the coordination and insertion ability of the metal center to olefins, and uses this type of single-component cationic nickel catalyst for homogeneous polymerization of olefins such as ethylene. It has high catalytic activity, good thermal stability, and high polymer molecular weight. In the homogeneous polymerization of ethylene, this type of cationic allyl nickel catalyst has a high activity, reaching 3.4×10 6 g PE(mol Ni) -1 h -1. A less branched polyolefin material with excellent mechanical and elastic properties was prepared, and the parameters such as molecular weight, branch density, melting point, etc. of the synthetic polyethylene can be adjusted. The cationic nickel complex of iminoindolone is a new catalyst that has not been developed yet. This catalyst is N,O-type and innovative. Its appearance has brought a new development direction to the polyolefin catalyst family and provided more choices. Therefore, the single-component nickel catalyst of the present invention has important industrial application value in the field of olefin polymerization. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 The NMR spectrum (400 MHz, CDCl) of the nickel complex Ni2 prepared in Example 2 is 3 );

[0028] Figure 2 The NMR carbon spectrum (100 MHz, CDCl) of the nickel complex Ni2 prepared in Example 2 3 );

[0029] Figure 3 The molecular weight M of the polymer prepared by item 10 in application example Table 1 is n data;

[0030] Figure 4 This is the branching degree data of the polymer prepared by item 10 in Application Example Table 1. DETAILED DESCRIPTION

[0031] In order to make the technical solution of the present invention clearer, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0032] Unless otherwise specified, the test materials and reagents used in the following examples can be obtained from commercial sources.

[0033] If no specific techniques or conditions are specified in the examples, they can be carried out according to the techniques or conditions described in the literature in the art or according to the product instructions.

[0034] The following examples illustrate the specific contents of the present invention. The data provided include the synthesis of the ligand, the synthesis of the complex, and the ethylene polymerization or copolymerization method, wherein the synthesis of the complex and the polymerization process are carried out in the absence of water and oxygen, all sensitive substances are stored in a glove box, all solvents are strictly dried and dehydrated, and ethylene gas is purified by a dehydration and deoxygenation column.

[0035] The silica gel column used 200-300 mesh silica gel, and the nuclear magnetic resonance used a Bruker 400 MHz nuclear magnetic resonance instrument; the molecular weight and molecular weight distribution were determined by GPC (polystyrene type columns, HR2 and HR4, chamber temperature was 160°C, using Water 1515 and Water 2414 pumps; the mobile phase was 1,2,4-trichlorobenzene, the flow rate was 1.0 ml per minute, and polydisperse polystyrene was used as the standard).

[0036] Example 1

[0037] The preparation process of nickel complex Ni1 is as follows:

[0038]

[0039] Preparation of 1-phenylindoledione S1: The 1-phenylindoledione S1 described in Example 1 was sourced from Titan Technology, AR pure.

[0040] Preparation of ligand L1: A solution of 1-phenyl isatin (1.68 g, 7.53 mmol), 2,6-diisopropylaniline (1.34 g, 7.53 mmol) and p-toluenesulfonic acid (20 mg) was placed in 60 mL of toluene and stirred at 120 ° C for 12 hours until a main spot appeared on the thin layer chromatography plate. The reaction mixture was cooled to room temperature and extracted with dichloromethane (3×30 ml). The organic layers were combined, washed with saturated brine, and dried over anhydrous sodium sulfate. The solvent was removed under reduced pressure to obtain a crude product, which was then purified by rapid silica gel column chromatography (ethyl acetate / petroleum ether=1 / 10) to obtain a yellow solid (2.23 g, 81%).

[0041] The results of NMR analysis of L1 are as follows: 1 H NMR(400MHz,Chloroform-d)δ7.60–7.47(m,4H),7.47–7.40(m,1H),7.24(d,J=6.8Hz,4H), 6.83(d,J=8.0Hz,1H),6.74(t,J=7.6,7.6Hz,1H),6.33(d,J=7.7Hz,1H),2.84(m,2H,CH(CH 3 ) 2 ),1.18(d,J=6.9Hz,6H,CH(CH 3 ) 2 ),0.99(d,J=6.9Hz,6H,CH(CH 3 ) 2 ). 13C NMR(101MHz,Chloroform-d)δ162.08(s,C=N),155.13(s,C=O),147.59(s),146.27(s),134.88(s),134.05(s),133.69(s), 129.88(s),128.59(s),126.61(s),126.19(s),125.22(s),123.72(s),123.40(s),116.42(s),110.59(s),28.46(s,CH(CH 3 ) 2 ),23.60(s,CH(CH 3 ) 2 ).

[0042] The elemental analysis results of L1 are as follows: Elem.Anal.Calcd for C 26 H 26 N 2 O:C,81.64;H,6.85;N,7.32.Found:C,81.62;H,6.84;N,7.30.

[0043] Preparation of nickel complex Ni1: In a nitrogen atmosphere, the ligand 3-[(2,6-diisopropylphenyl)amino]-1-phenylindole-2-one L1 (183 mg, 0.48 mmol) prepared in Example 1 and the metal nickel precursor [Ni(allyl)Cl] 2 A mixture of (64.8 mg, 0.24 mmol) and sodium tetrakis(3,5-bis(trifluoromethyl)phenyl)borate NaBAF (425 mg, 0.48 mmol) was placed in 20 mL of dichloromethane and stirred at room temperature for 4 hours. The resulting mixture was filtered through diatomaceous earth and concentrated to obtain a black-red powder (568 mg, 88%). Its structural formula represents tetrakis(3,5-bis(trifluoromethyl)phenyl)borate anion, connected to Ni It represents allyl.

[0044] The NMR analysis results of Ni1 are as follows: 1 H NMR(400MHz,Chloroform-d)δ7.68(s,12H),7.54(s,4H),7.42–7.32(m,5H),6.96(s,2H),6.43 (s,1H),5.91(m,1H,ally),3.37(s,2H,ally),3.17(s,2H,ally),2.58(d,J=13.3Hz,2H,CH(CH 3 ) 2),1.35(s,6H,CH(CH 3 ) 2 ),1.03(s,6H,CH(CH 3 ) 2 ). 13 C NMR(151MHz,Chloroform-d)δ171.84(s,C=N),163.27(s,C=O),162.29(s),16 1.96(s),161.63(s),161.30(s),150.98(s),140.85(s),138.97(s),137.51( s),134.88(s),130.66(s),128.91(s),127.35(s),125.53(s),123.73(s),12 1.92(s),117.93(s),117.59(s),114.61(s),58.55(s,ally),29.46(s,CH(CH 3 ) 2 ),23.49(s,CH(CH 3 ) 2 ).

[0045] The elemental analysis results of Ni1 are as follows: Elem.Anal.Calcd for C 50 H 38 BF 8 N 2 NiO: C, 66.41; H, 4.24; N, 3.10. Found: C, 66.39; H, 4.22; N, 3.09.

[0046] Example 2

[0047] The preparation process of nickel complex Ni2 is as follows:

[0048]

[0049] Preparation of 1-(2,6-dimethylbenzyl)indoledione S2: In a Schlenk flask filled with nitrogen, indole-2,3-dione (7.36 g, 50 mmol) was mixed with 60 mL of N,N-dimethylformamide (DMF), sodium hydride (3.12 g, 65 mmol) was slowly added at 0°C, and stirred for 0.5 hours. Then 2-(bromomethyl)-1,3-dimethylbenzene (11.96 g, 60 mmol) was added, and the reaction mixture was stirred at room temperature for 2 hours. Water (200 mL) was added, filtered and the resulting precipitate was dissolved with dichloromethane, washed with saturated brine, and dried over anhydrous sodium sulfate. The solvent was removed under reduced pressure to obtain a crude product, which was further purified by recrystallization from ethyl acetate. The target skeleton (9.6 g, 73%) was obtained as an orange-red powder.

[0050] The NMR analysis results of S2 are as follows: 1 H NMR(400MHz,Chloroform-d)δ7.56(d,J=7.5Hz,1H),7.31(t,1H),7.14(t,J=7.6Hz,1H),7.08–6.97(m,3H),6.36(d,J=8.0Hz,1H),5.02(s,2H,aryl-CH 2 ),2.36(s,6H,aryl-CH 3 ). 13 C NMR(101MHz,Chloroform-d)δ183.28(s),158.04(s),151.03(s),138.42(s),137.42(s),130 .01(s),129.23(s),128.34(s),125.31(s),123.61(s),117.79(s),111.36(s),40.04(s,N-CH 2 ),20.60(s,aryl-CH 3 ).

[0051] The elemental analysis results of S2 are as follows: Elem.Anal.Calcd for C 17 H 15 NO 2 :C,76.96;H,5.70;N,5.28.Found:C,76.95;H,5.68;N,5.27.

[0052] Preparation of ligand L2: The synthesis steps are the same as L1. The difference is that 1-(2,6-dimethylbenzyl)indole-2,3-dione (2 g, 7.53 mmol) is added. The product is a yellow solid (1.98 g, 62%).

[0053] The NMR analysis results of L2 are as follows: 1 H NMR(400MHz,Chloroform-d)δ7.12(s,3H),7.03(d,J=7.3Hz,1H),6.96(d,J=7.3Hz,3H ),6.51(t,J=7.6Hz,1H),6.23(d,J=8.0Hz,1H),6.12(d,J=7.6Hz,1H),5.05(s,2H,N-CH 2 ),2.72(m,2H,CH(CH 3 ) 2 ),2.30(s,6H,aryl-CH 3 ),1.09(d,J=6.8Hz,6H,CH(CH 3 ) 2 ),0.85(d,J=6.9Hz,6H,CH(CH 3 ) 2 ). 13 C NMR(101MHz,Chloroform-d)δ161.64(s,C=N),154.15(s,C=O),145.61(s),145.26(s),136.19(s),133.65(s),129. 67(s),128.16(s),126.96(s),124.78(s),123.97(s),122.53(s),121.58(s),115.41(s),109.41(s),38.80(s,N-CH 2 ),27.37(s,CH(CH 3 ) 2 ),22.38(s,CH(CH 3 ) 2 ),22.29(s,CH(CH 3 ) 2 ,19.48(s,aryl-CH 3 ).

[0054] The elemental analysis results of L2 are as follows: Elem.Anal.Calcd for C 29 H 32 N 2 O:C,82.04;H,7.60;N,6.60.Found:C,82.02;H,7.61;N,6.58.

[0055] Preparation of nickel complex Ni2: The synthesis steps are the same as Ni1. The difference is that the added ligand L2 is 3-[(2,6-diisopropylphenyl)amino]-1-(2,6-dimethylbenzyl)indol-2-one (203 mg, 0.48 mmol). A black-red powder (532 mg, 80%) was obtained.

[0056] The results of NMR analysis of Ni2 are as follows: 1 H NMR (400MHz, Chloroform-d) δ7.57(s,12H),7.21(d,J=8.0Hz,3H),7.10(d,J=7.7Hz,1H),6.98(d,J=7.6Hz,2H),6.76(s,1H),6.40(d,J=8 .1Hz,1H),6.20(d,J=7.7Hz,1H),5.89–5.75(m,1H,ally),4.92(s,2H),3.26(s,2H,ally)3.00(s,2H,ally),2.48(d,J=13.6Hz,2H,CH(CH 3 ) 2 ),2.21(s,6H,aryl-CH 3 ),1.23(d,J=6.8Hz,6H,CH(CH 3 ) 2 ),0.87(d,J=6.8Hz,6H,CH(CH 3 ) 2 ). 13 C NMR(151MHz,Chloroform-d)δ172.53(s,C=N),163.20(s,C=O),162.25(s),161.94(s),161.60(s),161.26(s),138.99(s),137.29(s),134.86( s),129.77(s),129.08(s),127.32(s),126.79(s),125.51(s),125.16( s),123.70(s),121.89(s,ally),117.58(s),114.74(s),42.09(s,N-CH 2 ),29.52(s,CH(CH 3 ) 2 ),23.74(s,CH(CH 3 ) 2 ),23.36(s,CH(CH 3 ) 2 ),20.16(s,aryl-CH 3 ).

[0057] Figure 1 and Figure 2 The nuclear magnetic hydrogen spectrum and carbon spectrum (400MHz, CDCl 3 ).

[0058] The elemental analysis results of Ni2 are as follows: Elem.Anal.Calcd for C 53 H 44 BF 8 N 2 NiO: C, 67.26; H, 4.69; N, 2.96. Found: C, 67.24; H, 4.70; N, 2.95.

[0059] Example 3

[0060] The preparation process of nickel complex Ni3 is as follows:

[0061]

[0062] Preparation of 1-trityl indoledione S3: The steps are the same as S1, except that triphenylmethyl bromide (21 g, 65 mmol) is added to obtain the target skeleton (11.7 g, 60%) in the form of an orange-red powder.

[0063] The NMR analysis of S3 was consistent with the literature.

[0064] The elemental analysis results of S3 are as follows: Elem.Anal.Calcd for C 27 H 19 NO 2 :C,83.27;H,4.92;N,3.60.Found:C,83.26;H,4.90;N,3.59.

[0065] Preparation of ligand L3: The synthesis steps are the same as L1. The difference is that 1-triphenylindole-2,3-dione (2.93 g, 7.53 mmol) is added. The product is a yellow solid (1.32 g, 32%).

[0066] The results of NMR analysis of L3 are as follows: 1 H NMR(400MHz,Chloroform-d)δ7.49–7.40(m,6H),7.27(m,8H),7.21–7.15(m,3H),7.06(m,1H),6. 88(m,1H),6.56(t,J=7.6Hz,1H),6.32(d,J=8.3Hz,1H),6.21(d,J=7.7Hz,1H),2.72(m,2H,CH(CH 3 ) 2),1.28(d,J=6.7Hz,2H,CH(CH 3 ) 2 ),1.14(dd,J=13.6,6.8Hz,5H,CH(CH 3 ) 2 ),0.93(d,J=6.9Hz,5H,CH(CH 3 ) 2 ). 13 C NMR(101MHz,Chloroform-d)δ163.77(s,C=N),155.14(s,C=O),147.86(s),146.50(s),141.60(s),134.75(s),132.25(s), 129.57(s),128.87(s),127.78(s),127.16(s),125.11(s),123.56(s),122.25(s),117.53(s),117.08(s),75.37(s,N-CPh 3 ),28.39(s,CH(CH 3 ) 2 ),23.45(s,CH(CH 3 ) 2 ).

[0067] The elemental analysis results of L3 are as follows: Elem.Anal.Calcd for C 39 H 36 N 2 O:C,85.37;H,6.61;N,5.11.Found:C,85.36;H,6.59;N,5.12.

[0068] Preparation of nickel complex Ni3: The synthesis steps are the same as Ni1. The difference is that 3-[(2,6-diisopropylphenyl)amino]-1-triphenylindole-2-one (263 mg, 0.48 mmol) is added. A black-red powder (566 mg, 78%) is obtained.

[0069] The NMR analysis results of Ni3 are as follows: 1H NMR(400MHz,Chloroform-d)δ7.72(s,12H),7.31(s,17H),7.12(d,J=7.4Hz,2H),6.89(d,J=8.2Hz,1H),6.59(d,J=8.0Hz ,1H),6.31(d,J=7.8Hz,1H),5.99–5.84(m,1H,ally),3.07(s,2H,ally),2.84(s,2H,ally),2.56(d,J=13.6Hz,2H,CH(CH 3 ) 2 ),1.30(d,J=42.9Hz,12H,CH(CH 3 ) 2 ). 13 C NMR(151MHz,Chloroform-d)δ172.30(s,C=N),162.19(s,C=O),161.29(s),160.96(s),160.63(s),160.30(s),145.55(s),142.99(s),133.82(s), 128.52(s),127.97(s),127.15(s),126.59(s),125.35(s),124.47(s),1 24.06(s),122.67(s),120.86(s),116.60(s),113.88(s),81.68(s,N-CPh 3 ),57.38(s,ally),55.95(s,ally),28.33(s,CH(CH 3 ) 2 ),22.37(s,CH(CH 3 ) 2 ).

[0070] The elemental analysis results of Ni3 are as follows: Elem.Anal.Calcd for C 63 H 48 BF 8 N 2 NiO: C, 70.68; H, 4.52; N, 2.62. Found: C, 70.66; H, 4.51; N, 2.60.

[0071] Example 4

[0072] The preparation process of nickel complex Ni4 is as follows:

[0073]

[0074] Preparation of 1-(2,6-dimethylbenzyl)indoledione S2: The synthesis process of substrate S2 is shown in Example 2.

[0075] Preparation of ligand L4: A solution of 1-(2,6-dimethylbenzyl)indole-2,3-dione (2 g, 7.53 mmol), 2,6-bis(diphenylmethyl)-4-methylaniline (3.31 g, 7.53 mmol) and p-toluenesulfonic acid (20 mg) was placed in 60 mL of toluene and stirred at 120 ° C for 12 hours until a main spot appeared on the thin layer chromatography plate. The reaction mixture was cooled to room temperature and extracted with dichloromethane (3×30 ml). The organic layers were combined, washed with saturated brine, and dried over anhydrous sodium sulfate. The solvent was removed under reduced pressure to obtain a crude product, which was then purified by rapid silica gel column chromatography (ethyl acetate / petroleum ether=1 / 10) to obtain a yellow solid (2.56 g, 50%).

[0076] The results of NMR analysis of L4 are as follows: 1 H NMR(400MHz,Chloroform-d)δ7.27–7.22(m,5H),7.19(d,J=7.1Hz,2H),7.14(d,J=6.8Hz,1H),7.09–7.02(m,6H),6.93(d,J=6.7Hz,4H),6.88(t,J =7.6Hz,4H),6.77(d,J=2.8Hz,1H),6.75(s,1H),6.71(s,2H),6.27(t,J= 7.6Hz,1H),5.93(d,J=7.9Hz,1H),5.80(d,J=8.1Hz,1H),5.37(s,2H,CHPh 2 ),4.98(s,2H,N-CH 2 ),2.40(s,6H,aryl-CH 3 ),2.20(s,3H,aryl-CH 3 ). 13 C NMR(101MHz,Chloroform-d)δ162.66(s,C=N),156.62(s,C=O),145.93(s), 145.50(s),143.07(s),141.88(s),137.45(s),133.42(s),133.26(s),131. 40(s),129.74(s),129.53(s),129.11(s),128.86(s),128.23(s),128.06(s) ),126.28(s),125.99(s),121.69(s),116.18(s),109.13(s),52.12(s,CHPh 2),40.06(s,N-CH 2 ),21.54(s,aryl-CH 3 ),20.65(s,aryl-CH 3 ).

[0077] The elemental analysis results of L4 are as follows: Elem.Anal.Calcd for C 50 H 42 N 2 O:C,87.43;H,6.16;N,4.08.Found:C,87.41;H,6.15;N,4.07.

[0078] Preparation of nickel complex Ni4: The synthesis steps are the same as Ni1. The difference is that 3-[(2,6-diphenylmethyl)amino]-1-(2,6-dimethylbenzyl)indol-2-one (330 mg, 0.48 mmol) is added. A black-red powder (712 mg, 90%) is obtained.

[0079] The results of NMR analysis of Ni4 are as follows: 1 H NMR(400MHz,Chloroform-d)δ7.82(s,12H),7.59(s,7H),7.47(s,4H),7.39(s,2H),7.27(t,J=7.5Hz,3H),7. 11(s,5H),6.99(s,5H),6.84(t,J=7.8Hz,1H),6.43(d,J=8.0Hz,1H),6.30(d,J=7.5Hz,1H),5.56(s,2H,CHPh 2 ),5.52–5.45(m,1H,ally),5.05(s,2H,N-CH 2 ),2.46(s,6H,aryl-CH 3 ),2.32(s,3H,aryl-CH 3 ). 13CNMR(151MHz,Chloroform-d)δ172.35(s,C=N),163.53(s,C=O),162.41(s),162.08(s),1 61.75(s),161.42(s),149.32(s),140.57(s),140.29(s),139.00(s),137.31(s),135.00 (s),129.80(s),129.64(s),129.40(s),129.30(s),128.98(s),127.85(s),127.38(s),1 25.65(s),123.84(s),122.03(s),117.66(s),114.42(s,ally),113.87(s),53.18(s,CHPh 2 ),42.17(s,N-CH 2 ),21.56(s,aryl-CH 3 ),20.34(s,aryl-CH 3 ).

[0080] The elemental analysis results of Ni4 are as follows: Elem.Anal.Calcd for C 74 H 54 BF 8 N 2 NiO: C, 73.53; H, 4.50; N, 2.32. Found: C, 73.51; H, 4.48; N, 2.33.

[0081] Example 5

[0082] The preparation process of nickel complex Ni5 is as follows:

[0083]

[0084] Preparation of 1-(2,6-dimethylbenzyl)indoledione S2: The synthesis process of substrate S2 is shown in Example 2.

[0085] Preparation of ligand L5: The synthesis steps are the same as those of L4, except that 8-(p-tolyl)naphthalene-1-amine (1.76 g, 7.53 mmol) is added to obtain a red solid (2.6 g, 72%).

[0086] The elemental analysis results of L5 are as follows: Elem.Anal.Calcd for C 34 H 28 N 2 O:C,84.97;H,5.87;N,5.83.Found:C,84.93;H,5.85;N,5.85.

[0087] Preparation of nickel complex Ni5: The synthesis steps are the same as Ni1. The difference is that 1-(2,6-dimethylbenzyl)-3-((8-(p-tolyl)naphthalen-1-yl)amino)indol-2-one (230 mg, 0.48 mmol) is added. A black-red powder (665 mg, 96%) is obtained.

[0088] The NMR analysis results of Ni5 are as follows: 1 H NMR(400MHz,Chloroform-d)δ7.69(s,12H),7.61(d,J=7.1Hz,1H),7.48(s,4H),7.44(d,J=7.1Hz,1H),7.24–7.18(m,2H),7.10(m, 4H),6.82(d,J=7.7Hz,1H),6.70(t,J=7.7,1H),6.59(m,2H),6.14(d,J=6.4Hz,1H),5.84(m,1H,ally),4.91(d,J=15.1Hz,1H,N-CH 2 ),4.69(d,J=15.1Hz,1H,N-CH 2 ),2.31(s,9H,aryl-CH 3 ). 13 C NMR(101MHz)δ170.87(s,C=N),161.17(s),160.68(s,C=O),160.18(s),159.69(s),156.33(s),148 .34(s),140.81(s),138.93(s),137.69(s),136.44(s),136.18(s),133.52(s),129.82(s),129.58 (s),128.70(s),128.32(s),128.12(s),127.48(s),127.29(s),126.04(s),125.80(s),124.61(s) ,124.05(s),121.90(s),119.19(s),117.08(s),116.20(s),114.22(s),112.17(s),54.45(s,N-CH 2 ),40.41(s),19.74(s,aryl-CH 3 ),18.90(s,aryl-CH 3 ).

[0089] The elemental analysis results of Ni5 are as follows: Elem.Anal.Calcd for C 61 H46 BF 8 N 2 NiO: C, 70.14; H, 4.44; N, 2.68. Found: C, 70.15; H, 4.41; N, 2.66.

[0090] Application Examples

[0091] The nickel complexes prepared in Examples 1 to 5 were respectively used as catalysts to carry out ethylene polymerization reactions. The specific polymerization methods are as follows:

[0092] In a glove box and under a nitrogen atmosphere, 40 mL of toluene was added to a 350 mL pressure bottle (with a magnetic stirring device, an oil bath heating device and a thermometer), and then the container was connected to a high-pressure pipeline and the pipeline was evacuated and kept warm for 5 minutes; 5 μmol of the nickel complex prepared in Examples 1 to 5 was dissolved in 2 mL of dichloromethane and injected into the pressure bottle through a syringe; then the ethylene valve was opened, ethylene was introduced into the pressure bottle, and the ethylene pressure was adjusted to 8 atmospheres, and the reaction was carried out for 30 minutes; then the reaction was stopped, the pressure bottle was opened, ethanol was added to the pressure bottle to precipitate a solid, the pressure was reduced and filtered, and a white solid was dried in a vacuum drying oven.

[0093] The specific experimental conditions (catalyst Cat. and temperature T), yield (Yield), catalytic activity (Act.), polymer number average molecular weight (M) of the nickel complex prepared in Examples 1 to 5 of the present invention for ethylene polymerization n The polymerization result data such as ), polymer molecular weight distribution (PDI), degree of branching (B) are shown in Table 1 below.

[0094] Table 1 Catalysts for ethylene polymerization a

[0095]

[0096]

[0097] in, a Polymerization conditions: catalyst 5 μmol, toluene = 38 mL, dichloromethane = 2 mL, ethylene = 8 atmospheres, time = 30 minutes, b Activity=10 6 g·mol -1 ·h -1 ; c The number average molecular weight was determined by GPC at 150°C using polystyrene as the standard and trichlorobenzene as the solvent. d The degree of branching refers to the number of branches per 1000 carbon atoms, which is 1 Determined by H NMR nuclear magnetic resonance method. e Melting points were determined using a differential scanning calorimeter.

[0098] In summary, the present invention introduces a series of α-imidoindolone-based N,O-type nickel olefin polymerization catalysts. The single-component nickel catalyst can efficiently polymerize ethylene. As can be seen from Table 1, the catalysts Ni1-Ni5 in Examples 1-5 not only exhibit excellent activity and outstanding thermal stability, but also can efficiently catalyze ethylene polymerization to produce polyethylene materials with higher molecular weight, lower branching degree and higher melting point. The highest activity reached 3.40×10 6 g·mol -1 ·h -1 ; Melting point is 69.1~119.9℃; The maximum number average molecular weight is 4.51×10 5 g / mol (by Figure 3 It can be known that Figure 4 It can be seen that the degree of branching is 13 branches / 1000 carbons.

[0099] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the patent of the present invention. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A N,O-type α-imidoindolone ligand, characterized in that: Its general structural formula L is shown below: Wherein, in the general formula, Ar is selected from one of differently substituted phenyl, naphthyl, and anthracenyl; R is selected from one of C1-C20 alkyl, differently substituted phenyl, benzyl, naphthyl, and triarylmethyl.

2. The N,O-type α-imidinolone ligand according to claim 1, characterized in that: The ligand structural formula is one of L1 to L5:

3. A method for preparing the N,O-type α-imidoindolone ligand as claimed in claim 1 or 2, characterized in that: Under nitrogen or argon, α,β-indolequinone is used as a basic reaction raw material, and different sterically hindered substituent groups R are installed on the indole-NH through a substitution reaction, and then different imine substituent groups Ar are further introduced at the α-position of indolequinone through a condensation reaction to obtain a dual-site driven α-iminoindolone ligand; wherein Ar is selected from one of differently substituted phenyl, naphthyl, and anthracene; and R is selected from one of C1-C20 alkyl, differently substituted phenyl, benzyl, naphthyl, and triarylmethyl.

4. A nickel complex of N,O-type α-imidoindolone ligand as claimed in claim 1 or 2, characterized in that: Its general structural formula C is shown below: Wherein, in the general formula, Ar is selected from one of phenyl, naphthyl and anthracenyl with different substitutions; R is selected from one of C1-C20 alkyl, phenyl with different substitutions, benzyl, naphthyl and triarylmethyl; represents tetrakis(3,5-bis(trifluoromethyl)phenyl)borate anion, connected to Ni It represents allyl.

5. The nickel complex of N,O-type α-imidoindolone ligand according to claim 4, characterized in that: Ar is phenyl, benzyl, or trityl; R is 2,6-diisopropylphenyl, 2,6-diphenylmethyl, or 8-toluene-substituted naphthylamine, and the ligand structural formula is one of Ni1-Ni5:

6. A method for preparing the nickel complex of N,O-type α-imidoindolone ligand as claimed in claim 4 or 5, characterized in that: In an argon or nitrogen atmosphere, an α-imidoindolone ligand is dissolved in a good solvent to obtain a ligand solution; sodium tetrakis(3,5-bis(trifluoromethyl)phenyl)borate (NaBAF) and a metal nickel precursor are dissolved in a good solvent to obtain a metal nickel precursor solution, and then the ligand solution is added to the metal nickel precursor solution, reacted at room temperature, and then the solvent is removed to obtain the nickel complex.

7. The method for preparing the nickel complex of N,O-type α-imidoindolone ligand according to claim 6, characterized in that: The metal nickel precursor is [Ni(allyl)Cl]2; the good solvent is one or a mixture of toluene, dichloromethane, chloroform, dichlorobenzene, trichlorobenzene; and the reaction time is 1-12 hours.

8. Use of the nickel complex of N,O-type α-imidinolone ligand as claimed in any one of claims 4 to 6 as a catalyst for olefin polymerization.

9. Use of the nickel complex of N,O-type α-imidinolone ligand according to claim 8 as a catalyst for olefin polymerization, characterized in that: The polymerization reaction is carried out in an organic solvent, the amount of nickel complex used is 1-30 μmol / L, the polymerization pressure is 0.1-50 MPa, the reaction temperature is controlled to be 0-200° C., and the reaction time is 0.05-8.00 hours; the polymerization reaction is an ethylene / propylene homopolymerization reaction or a copolymerization reaction with a polar monomer.

10. Use of the nickel complex of N,O-type α-imidinolone ligand according to claim 9 as a catalyst for olefin polymerization, characterized in that: The organic solvent is a mixture of one or more of toluene, hexane, n-heptane, and chlorobenzene; the polar monomer is a C2-C20 α-olefin containing a polar group, or a cycloolefin containing a polar group; the polar group is an organic functional group containing oxygen, nitrogen, sulfur, or selenium; the polar group includes a hydroxyl group, a carboxyl group, an ester group, an alkoxy group, a ketone group, an amine group, an amide group, a thioether, a silyl ether, or a selenoether; and the polymerization reaction method includes one of slurry polymerization, ring tube polymerization, and gas phase polymerization.

Images