Metal organic complex as well as preparation method and application thereof

Abstract

The invention relates to a metal organic complex as well as a preparation method and application thereof. The metal organic complex has the structural characteristics as shown in the following formula I. The metal organic complex has higher catalytic activity on olefin polymerization. Formula I.

Description

Technical Field

[0001] This application relates to the field of catalyst technology, and in particular to an organometallic complex, its preparation method, and its application. Background Technology

[0002] In the history of catalyst development, traditional metallocene catalysts once held a dominant position. However, with the continuous advancement of science and technology, non-metallocene catalysts have gradually emerged, their development stemming from the ongoing exploration of more efficient and selective catalysts. Researchers have gradually developed high-performance non-metallocene catalysts through the combination and optimization of different metal complexes and organic ligands. Compared with traditional metallocene catalysts, organometallic complex catalysts exhibit advantages such as structural diversity, high activity, high selectivity, and good stability, and can be widely applied in fields such as polymer synthesis, fine chemical synthesis, petroleum refining, and chemical production.

[0003] However, the catalytic activity of traditional organometallic complex catalysts in olefin polymerization, especially in the copolymerization of olefins and α-olefins, needs to be further improved. Summary of the Invention

[0004] Based on this, this application provides a metal-organic complex with higher catalytic activity for olefin polymerization, its preparation method, and its application.

[0005] A first aspect of this application provides a metal-organic complex having the structural features shown in Formula I:

[0006] Formula I

[0007] R1, R3, R5, R7, R9, R 11 R 13 R 15 R 17 Independently, they are: H, C1~C10 alkyl or C6~C14 aryl groups substituted with C1~C10 alkyl;

[0008] X1, X2, and X3 are independently monovalent ligand groups;

[0009] M is a group IVB metal element.

[0010] In one embodiment, R1, R3, R5, R7, R9, R 11 R 13 R 15 R 17 Independently, each is a phenyl group substituted with a C1-C10 alkyl or a C1-C6 alkyl group. Further, R1, R3, R5, R7, R9, R... 11 R 13R 15 R 17 Each of the following is independently: a C1-C4 alkyl or a C1-C4 alkyl-substituted phenyl group.

[0011] In one embodiment, X1, X2, and X3 are independently of each other: halogen, C1-C3 alkyl, or benzyl. Optionally, X1, X2, and X3 are independently of each other: halogen or C1-C3 alkyl. Further optionally, X1, X2, and X3 are independently of each other: halogen.

[0012] In one embodiment, M is titanium, zirconium, or hafnium. Optionally, M is zirconium or hafnium. More preferably, M is zirconium.

[0013] A second aspect of this application provides a method for preparing the organometallic complex described in the first aspect, comprising the following steps:

[0014] The organometallic complex is prepared by complexing the compound shown in Formula II with the halide of M.

[0015] Alternatively, the compound shown in Formula II is complexed with a halide of M, and the product of the complexation reaction is then reacted with Grignard reagent R-Mg-X to prepare the organometallic complex.

[0016] Formula II

[0017] X represents halogen;

[0018] The definition of R is the same as that of X1, X2 or X3; optionally, R is a C1~C3 alkyl or benzyl.

[0019] In one embodiment, the method for preparing the organometallic complex has one or more of the following features:

[0020] (1) The molar ratio of the compound shown in Formula II to the halide of M is 1:(0.5~1);

[0021] (2) The molar ratio of the compound shown in Formula II to the halide of M and the Grignard reagent R-Mg-X is 1:(0.5~1):(2~2.3).

[0022] In one embodiment, the method for preparing the compound represented by Formula II includes the following steps:

[0023] Compounds shown in Formula III: ;

[0024] Compounds shown in Formula IV: ;

[0025] Compound shown in Formula V: ;

[0026] Compound shown in Formula VIII: ;

[0027] The compound shown in Formula VI: ;

[0028] The compound shown in Formula VII: ;

[0029] Compound V is prepared by reacting the compound shown in Formula III with the compound shown in Formula IV in the presence of an inorganic base and 1,2-dibromomethane.

[0030] Compound V is prepared by reacting the compound shown in Formula VIII with the compound shown in Formula VIII in the presence of an inorganic base and a noble metal catalyst.

[0031] The compound shown in formula VI is reacted with iodomethane in the presence of an organic base to prepare the compound shown in formula VII.

[0032] In the presence of an inorganic acid, the compound shown in Formula VII is subjected to a deprotection reaction to prepare the compound shown in Formula II.

[0033] In one embodiment, the method for preparing the compound represented by Formula II has one or more of the following features:

[0034] (1) The molar ratio of inorganic base to 1,2-dibromomethane used in the preparation of compounds shown in Formula III, Formula IV, and Formula V is 1: (0.8~1.2):(2~5):(0.4~0.6);

[0035] (2) The molar ratio of inorganic base to noble metal catalyst used in the preparation of compounds shown in formula V, formula VIII, and formula VI is 1: (0.8~1.2):(2~5):(0.001-0.0015);

[0036] (3) The molar ratio of the compound shown in Formula VI, the organic base and iodomethane is 1:(1.5~3):(1~1.5);

[0037] (4) The molar ratio of the compound shown in formula VII to the inorganic acid is 1:(2~5);

[0038] (5) The noble metal catalyst is palladium;

[0039] (6) The inorganic base used in preparing the compound shown in formula V is one or more of cesium carbonate, sodium carbonate, potassium hydroxide, and sodium hydroxide;

[0040] (7) The inorganic base used in preparing the compound shown in Formula VI is one or more of cesium carbonate, sodium carbonate, potassium hydroxide and sodium hydroxide.

[0041] A third aspect of this application provides the use of the organometallic complex described in the first aspect as a catalyst in the preparation of polyolefins.

[0042] A fourth aspect of this application provides a method for preparing a polyolefin, comprising the following steps:

[0043] In the presence of a catalyst, olefin monomers are polymerized to prepare polyolefins; the catalyst includes the organometallic complex described in the first aspect.

[0044] In one embodiment, the olefin monomer includes ethylene and α-olefin;

[0045] In one embodiment, the catalyst further includes a co-catalyst, which includes one or more of methylaluminoxane, ethylaluminoxane, and boron salt compounds.

[0046] In one embodiment, the cocatalyst comprises one or both of methylaluminoxane and ethylaluminoxane. Further, the molar ratio of Al in the cocatalyst to M in the organometallic complex is 4–300.

[0047] The aforementioned organometallic complex, through a specific ligand molecular structure design, utilizes the coordination of heteroatoms to form three coordinate bonds and four covalent bonds with the central metal M. The central metal has a stable electronic structure, and after forming a cationic active center, it exhibits strong Lewis acidity, thus demonstrating high catalytic activity. Simultaneously, the sterically hindered electron-donating groups contribute to stabilizing the active center and enhancing catalytic activity. Based on this, the organometallic complex can be applied as a catalyst in the catalytic preparation of polyolefins, particularly demonstrating high catalytic activity in the copolymerization of olefins / α-olefin monomers.

[0048] Furthermore, the specific steric hindrance effect ensures that the spontaneous complexation direction between the monomer and the active center is relatively fixed, which is beneficial for improving the regioselectivity of the catalyst and the stereoregularity of the polymer. At the same time, the use of a specific single active center combined with specific steric hindrance effect and strong electron-donating effect is conducive to obtaining polymer products with higher molecular weight, narrower molecular weight distribution, and uniform distribution of comonomers in the polymer backbone.

[0049] Furthermore, by adjusting the electronic and volume effects of the substituent groups, the direction of monomer insertion can be fixed as X1, X2, X3. Therefore, this organometallic complex also exhibits good stereoselectivity and regioselectivity as a catalyst, which is beneficial to improving the insertion rate and regularity of the comonomer. The modification of electron-donating groups also makes chain transfer less likely to occur during the polymerization process, thereby increasing the molecular weight of the polymer. Detailed Implementation

[0050] The organometallic complexes of this application, their preparation methods, and applications are further described in detail below with reference to specific embodiments. This application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the disclosure of this application.

[0051] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0052] In this article, "one or more" refers to any one, two or more of the listed items.

[0053] In this application, terms such as "first aspect," "second aspect," "third aspect," and "fourth aspect" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or quantity, nor should they be construed as implicitly indicating the importance or quantity of the indicated technical features. Moreover, terms such as "first," "second," "third," and "fourth" serve only as a non-exhaustive enumeration and should be understood not to constitute a closed limitation on quantity.

[0054] In this application, the technical features described in an open-ended manner include both closed technical solutions consisting of the listed features and open technical solutions that include the listed features.

[0055] In this application, numerical ranges are referred to as continuous unless otherwise specified, and include the minimum and maximum values ​​of the range, as well as every value between the minimum and maximum values. Furthermore, when the range refers to integers, it includes every integer between the minimum and maximum values ​​of the range. Additionally, when multiple ranges are provided to describe a feature or characteristic, the ranges may be merged. In other words, unless otherwise specified, all ranges disclosed herein should be understood to include any and all subranges to which they are incorporated.

[0056] Unless otherwise specified, the percentage content mentioned in this application refers to mass percentage for solid-liquid mixtures and solid-phase-solid mixtures, and volume percentage for liquid-phase-liquid mixtures.

[0057] Unless otherwise specified, all percentage concentrations mentioned in this application refer to the final concentration. The final concentration refers to the proportion of the added component in the system after the addition of that component.

[0058] Unless otherwise specified, the temperature parameters in this application may be either constant temperature processing or processing within a certain temperature range. The constant temperature processing allows for temperature fluctuations within the precision range controlled by the instrument.

[0059] In this application, room temperature generally refers to 4℃~30℃, and preferably 20±5℃.

[0060] In this document, the term "alkyl" refers to a monovalent residue formed by the loss of a hydrogen atom from a saturated hydrocarbon containing a primary (normal) carbon atom, or a secondary carbon atom, or a tertiary carbon atom, or a quaternary carbon atom, or a combination thereof. Phrases containing this term, such as "C1-9 alkyl," refer to alkyl groups containing 1 to 10 carbon atoms, and each occurrence can be independently C1 alkyl, C2 alkyl, C3 alkyl, C4 alkyl, C5 alkyl, C6 alkyl, C7 alkyl, C8 alkyl, C9 alkyl, and C10 alkyl. Suitable examples include, but are not limited to: methyl (Me, -CH3), ethyl (Et, -CH2CH3), 1-propyl (n-Pr, n-propyl, -CH2CH2CH3), 2-propyl (i-Pr, i-propyl, -CH(CH3)2), 1-butyl (n-Bu, n-butyl, -CH2CH2CH2CH3), 2-methyl-1-propyl (i-Bu, i-butyl, -CH2CH(CH3)2), 2-butyl (s-Bu, s-butyl, -CH(C H3)CH2CH3), 2-methyl-2-propyl (t-Bu, t-butyl, -C(CH3)3), 1-pentyl (n-pentyl, -CH2CH2CH2CH2CH3), 2-pentyl (-CH(CH3)CH2CH2CH3), 3-pentyl (-CH(CH2CH3)2), 2-methyl-2-butyl (-C(CH3)2CH2CH3), 3-methyl-2-butyl (-CH(CH3)CH(CH3)2), 3-methyl-1-butyl (- CH2CH2CH(CH3)2), 2-methyl-1-butyl(-CH2CH(CH3)CH2CH3), 1-hexyl(-CH2CH2CH2CH2CH2CH3), 2-hexyl(-CH(CH3)CH2CH2CH2CH3), 3-hexyl(-CH(CH2CH3)(CH2CH2CH3)), 2-methyl-2-pentyl(-C(CH3)2CH2CH2CH3), 3-methyl-2-pentyl(-CH(CH3)CH( CH3)CH2CH3), 4-methyl-2-pentyl (-CH(CH3)CH2CH(CH3)2), 3-methyl-3-pentyl (-C(CH3)(CH2CH3)2), 2-methyl-3-pentyl (-CH(CH2CH3)CH(CH3)2), 2,3-dimethyl-2-butyl (-C(CH3)2CH(CH3)2), 3,3-dimethyl-2-butyl (-CH(CH3)C(CH3)3 and octyl (-(CH2)7CH3).

[0061] "Aryl" refers to an aromatic hydrocarbon group derived from an aromatic ring compound by removing one hydrogen atom. It can be a monocyclic aryl, a fused-ring aryl, or a polycyclic aryl. For polycyclic compounds, at least one ring must be an aromatic ring system. For example, "C6-C14 aryl" refers to an aryl group containing 6 to 14 carbon atoms, and each occurrence can be independently C6, C10, C12, or C14 aryl. Suitable examples include, but are not limited to: benzene, biphenyl, naphthalene, anthracene, phenanthrene, dinaphthalene, triphenylene, and their derivatives.

[0062] "Halogen" or "halogen group" refers to F, Cl, Br or I.

[0063] Some examples of this application provide a metal-organic complex having the structural features shown in Formula I:

[0064] Formula I

[0065] R1, R3, R5, R7, R9, R 11 R 13 R 15 R 17 Each of the following is independently: H, C1~C6 alkyl or C1~C10 alkyl-substituted C6~C14 aryl;

[0066] X1, X2, and X3 are independently monovalent ligand groups;

[0067] M is a group IVB metal element.

[0068] In some of these examples, R1, R3, R5, R7, R9, R 11 R 13 R 15 R 17 Independently, each is a phenyl group substituted with a C1-C10 alkyl or a C1-C6 alkyl group. Further, R1, R3, R5, R7, R9, R... 11 R 13 R 15 R 17 Each of the following is independently: a C1-C4 alkyl or a C1-C4 alkyl-substituted phenyl group.

[0069] Without restriction, R1, R3, R5, R7, R9, R 11 R 13 R 15 R 17 The following are independent of each other: methyl, ethyl, propyl, isopropyl, methoxy, tert-butyl, cyclohexyl, adamantane, cumene, or diethylbenzene.

[0070] Understandably, X1, X2, and X3 are not H. In some examples, X1, X2, and X3 are independently monovalent ligand groups having 1 to 20 atoms. Further, X1, X2, and X3 are independently halogenated, C1-C3 alkyl, or benzyl. Even further, X1, X2, and X3 are independently halogenated or C1-C3 alkyl. Still even further, X1, X2, and X3 are independently halogenated. Using suitable X1, X2, and X3 can achieve better catalytic effects, higher copolymerization activity, and the resulting polyethylene has a higher molecular weight and a narrower molecular weight distribution.

[0071] Without restriction, X1, X2, and X3 are independently of each other: halogen, methyl, or benzyl.

[0072] In some examples, M is titanium, zirconium, or hafnium. More specifically, M is zirconium or hafnium. Even further, M is zirconium. Using a suitable element M can achieve better catalytic performance, higher copolymerization activity, and result in polyethylene with a higher molecular weight.

[0073] Other examples of this application provide methods for preparing organometallic complexes as described above, including the following steps:

[0074] Option 1: Prepare the organometallic complex by complexing the compound shown in Formula II with the halide of M;

[0075] Alternatively, Option 2: The compound shown in Formula II is complexed with the halide of M, and then the product of the complexation reaction is reacted with Grignard reagent R-Mg-X to prepare the organometallic complex.

[0076] Formula II

[0077] X represents halogen;

[0078] The definition of R is the same as that of X1, X2 or X3; optionally, R is a C1~C3 alkyl or benzyl.

[0079] Understandably, in the above schemes, when X1, X2, and X3 are independently halogens, Scheme 1 is used for preparation; when X1, X2, and X3 are independently monovalent ligand groups other than halogens, Scheme 2 is used, mainly by introducing X1, X2, or X3 through R in the Grignard reagent R-Mg-X. In some examples, R can be a C1-C3 alkyl or benzyl group. Without limitation, R can be methyl or benzyl.

[0080] In some of these examples, the reaction is carried out using an ultra-dry organic solvent (“ultra-dry” means a water content ≤20 ppm). Without limitation, the ultra-dry organic solvent is one or more of toluene, butyl ether, diethyl ether, tetrahydrofuran, n-hexane, and n-heptane.

[0081] In some of these examples, the halide of M is a halide of a Group IVB metal. Without limitation, it can be one or more of a chloride, bromide, and iodide of a Group IVB metal.

[0082] In some of these examples, the Grignard reagent R-Mg-X is one or more of methyl magnesium bromide, methyl magnesium chloride, benzyl magnesium bromide, and benzyl magnesium chloride.

[0083] In some examples, in Scheme 1, the conditions for the complexation reaction include: a temperature of 60°C to 100°C and a time of 4h to 12h. Specifically, the temperature includes, but is not limited to: 60°C, 70°C, 80°C, 90°C, 100°C or any two of the foregoing; the time includes, but is not limited to: 4h, 6h, 8h, 10h, 12h or any two of the foregoing.

[0084] In some examples, in Scheme 1, the molar ratio of the compound represented by Formula II to the halide of M is 1:(0.5~1). Specifically, the molar ratio of the compound represented by Formula II to the halide of M includes, but is not limited to: 1:0.5, 1:0.6, 1:0.8, 1:1 or any range between the two.

[0085] In some examples, in Scheme 2, the conditions for the complexation reaction include: a temperature of 60℃ to 100℃ and a time of 4h to 12h. Specifically, the temperature includes, but is not limited to, 60℃, 70℃, 80℃, 90℃, 100℃, or any range between the two; the time includes, but is not limited to, 4h, 6h, 8h, 10h, 12h, or any range between the two. Without limitation, after the complexation reaction is completed, no post-treatment is required, and the Grignard reagent R-Mg-X is directly added to continue the reaction.

[0086] In some examples, in Scheme 2, the reaction conditions with the Grignard reagent R-Mg-X include a temperature of -10°C to 0°C and a time of 1 h to 3 h. Specifically, the time includes, but is not limited to, 1 h, 2 h, 3 h, or any range between the two.

[0087] In some examples, in Scheme 2, the molar ratio of the compound shown in Formula II to the halide of M and the Grignard reagent R-Mg-X is 1:(0.5~1):(2~2.3). Specifically, the molar ratio of the compound shown in Formula II to the halide of M and the Grignard reagent R-Mg-X includes, but is not limited to: 1:0.5:2, 1:0.6:2.2, 1:0.8:2.3, 1:1:2.3 or any range between the foregoing.

[0088] Furthermore, in some of these examples, the method for preparing the compound represented by Formula II includes the following steps:

[0089] Compounds shown in Formula III: ;

[0090] Compounds shown in Formula IV: ;

[0091] Compound shown in Formula V: ;

[0092] Compound shown in Formula VIII: ;

[0093] The compound shown in Formula VI: ;

[0094] The compound shown in Formula VII: ;

[0095] 1) In the presence of an inorganic base and 1,2-dibromomethane, the compound shown in Formula III is reacted with the compound shown in Formula IV to prepare the compound shown in Formula V;

[0096] 2) In the presence of an inorganic base and a noble metal catalyst, the compound shown in formula V is reacted with the compound shown in formula VIII to prepare the compound shown in formula VI;

[0097] 3) In the presence of an organic base, the compound shown in formula VI is reacted with iodomethane to prepare the compound shown in formula VII;

[0098] 4) In the presence of an inorganic acid, the compound shown in Formula VII is subjected to a deprotection reaction to prepare the compound shown in Formula II.

[0099] In some of these examples, the reaction in steps 1) to 4) is carried out using an ultra-dry organic solvent.

[0100] In some of these examples, in step 1), the compound represented by Formula III is one or more of 2,5-di-tert-butyl-6-bromophenol, 2,5-dimethoxy-6-bromophenol, 2-methyl-5-tert-butyl-6-bromophenol, and 2-tert-butyl-5-methoxy-6-bromophenol.

[0101] In some of these examples, in step 1), the compound represented by formula IV is one or more of 2,5-di-tert-butyl-6-(hydroxytetrahydropyran)phenol, 2,5-dimethoxy-6-(hydroxytetrahydropyran)phenol, 2-methyl-5-tert-butyl-6-(hydroxytetrahydropyran)phenol, and 2-tert-butyl-5-methoxy-(hydroxytetrahydropyran)phenol.

[0102] In some of these examples, in step 1), the inorganic base is one or more of cesium carbonate, sodium carbonate, potassium hydroxide, and sodium hydroxide.

[0103] In some of these examples, in step 1), the solvent used for the reaction is one or more of acetonitrile, tetrahydrofuran, N,N-dimethylformamide, and dimethyl sulfoxide.

[0104] In some examples, in step 1), the molar ratio of the compound of Formula III, the compound of Formula IV, the inorganic base, and 1,2-dibromomethane is 1:(0.8~1.2):(2~5):(0.4~0.6). Specifically, the molar ratio of the compound of Formula III, the compound of Formula IV, the inorganic base, and 1,2-dibromomethane includes, but is not limited to: 1:1:2:0.4, 1:1:2:0.5, 1:1:3:0.6, 1:1:4:0.6, 1:1:5:0.5, 1:1:5:0.4, or any range between the foregoing.

[0105] In some examples, in step 1), the reaction conditions include: a temperature of 0°C to 80°C and a time of 0.5h to 2h. Specifically, the temperature includes, but is not limited to: 0°C, 20°C, 40°C, 50°C, 60°C, 80°C, or any two of the foregoing; the time includes, but is not limited to: 0.5h, 1h, 1.5h, 2h, or any two of the foregoing.

[0106] In some of these examples, in step 2), the inorganic base is one or more of cesium carbonate, sodium carbonate, potassium hydroxide, and sodium hydroxide.

[0107] In some examples, in step 2), the noble metal catalyst is palladium, including but not limited to: (2-dicyclohexylphosphino-2',4',6'-tris-isopropyl-1,1'-biphenyl)(2'-amino-1,1'-biphenyl-2-yl)palladium(II) (Xphos Pd G3), (2-dicyclohexylphosphino-2',4',6'-triisopropyl-1,1'-biphenyl)[2-(2'-amino-1,1'-biphenyl)]palladium(II) (Xphos Pd G2), (2-dicyclohexylphosphino-2',6'-diisopropoxy-1,1'-biphenyl)(2-amino-1,1'-biphenyl-2-yl)palladium(II) (Ruphos Pd G3), tetratriphenylphosphine palladium, palladium acetate, and palladium chloride, or one or more of these.

[0108] In some of these examples, in step 2), the solvent used for the reaction is one or more of methanol, tetrahydrofuran, ethanol, and water.

[0109] In some examples, in step 2), the molar ratio of the compound of formula V, the compound of formula VIII, the inorganic base, and the noble metal catalyst is 1:(0.8~1.2):(2~5):(0.001~0.0015). Specifically, the molar ratio of the compound of formula V, the compound of formula VIII, the inorganic base, and the noble metal catalyst includes, but is not limited to: 1:1:2:0:001, 1:1:3:0.0012, 1:1:4:0.0015, 1:1:5:0.0014, or any range between the two.

[0110] In some examples, in step 2), the reaction conditions include: a temperature of 60°C to 100°C and a time of 2 hours to 8 hours. Specifically, the temperature includes, but is not limited to, 60°C, 70°C, 80°C, 90°C, 100°C or any two of the foregoing; the time includes, but is not limited to, 3 hours, 4 hours, 6 hours, 8 hours or any two of the foregoing.

[0111] In some of these examples, in step 3), the organic base is one or more of triethylamine, diisopropylethylamine, diisopropylaminolithium, hexamethyldisilylaminolithium, and hexamethyldisilylaminosodium.

[0112] In some of these examples, in step 3), the solvent used for the reaction is one or more of butyl ether, tetrahydrofuran, and N,N-dimethylformamide.

[0113] In some examples, in step 3), the molar ratio of the compound of formula VI, the organic base, and iodomethane is 1:(1.5~3):(1~1.5). Specifically, the molar ratio of the compound of formula VI, the organic base, and iodomethane includes, but is not limited to: 1:1.5:1, 1:2:1, 1:3:1.2, 1:2:1.3, 1:3:1.5, or any range between the foregoing.

[0114] In some examples, in step 3), the reaction conditions include: a temperature of 0°C to 80°C and a time of 0.5h to 2h. Specifically, the temperature includes, but is not limited to: 0°C, 20°C, 40°C, 50°C, 60°C, 80°C, or any two of the foregoing; the time includes, but is not limited to: 0.5h, 1h, 2h, or any two of the foregoing.

[0115] In some of these examples, in step 4), the inorganic acid is dilute hydrochloric acid with a mass fraction of 10%.

[0116] In some of these examples, in step 4), the solvent used for the reaction is one or more of methanol, ethanol, and tetrahydrofuran.

[0117] In some examples, in step 4), the molar ratio of the compound represented by Formula VII to the inorganic acid is 1:(2~5). Specifically, the molar ratio of the compound represented by Formula VII to the inorganic acid includes, but is not limited to, 1:2, 1:3, 1:4, 1:5, or any range between the two aforementioned.

[0118] In some examples, in step 4), the reaction conditions include: a temperature of 0°C to 80°C and a time of 0.5h to 2h. Specifically, the temperature includes, but is not limited to: 0°C, 20°C, 40°C, 50°C, 60°C, 80°C, or any two of the foregoing; the time includes, but is not limited to: 0.5h, 1h, 2h, or any two of the foregoing.

[0119] Other examples of this application also provide the use of organometallic complexes as catalysts in the preparation of polyolefins, as described above.

[0120] In other examples of this application, a method for preparing a polyolefin is also provided, comprising the following steps:

[0121] In the presence of a catalyst, olefin monomers are polymerized to prepare polyolefins; the catalyst includes the organometallic complexes described above.

[0122] In some of these examples, the olefin monomer includes ethylene and α-olefins. Without limitation, the α-olefin includes one or more of butene, hexene, and octene.

[0123] In some examples, the aforementioned organometallic complex serves as the main catalyst, co-catalyzing the polymerization reaction with a co-catalyst. Further, the co-catalyst comprises one or more of methylaluminoxane, ethylaluminoxane, and boron salts. Even further, the co-catalyst comprises methylaluminoxane.

[0124] In some examples, the cocatalyst comprises one or both of methylaluminoxane and ethylaluminoxane. Further, the molar ratio (Al / M) of Al in the cocatalyst to M in the organometallic complex is 4–300. Specifically, Al / M includes, but is not limited to, 4, 5, 10, 20, 50, 80, 100, 120, 150, 170, 200, 220, 250, 270, 300, or a range between any two of the foregoing. Even more specifically, Al / M is 50–150.

[0125] In some examples, the polymerization conditions include a temperature of 20°C to 250°C and a pressure of 0.1 MPa to 10 MPa. Specifically, the temperature includes, but is not limited to, 20°C, 40°C, 60°C, 80°C, 100°C, 120°C, 140°C, 150°C, 180°C, 200°C, 220°C, 250°C, or any two of the foregoing, further, 80°C to 150°C, and even further, 80°C to 120°C; the pressure includes, but is not limited to, 0.1 MPa, 0.5 MPa, 1 MPa, 2 MPa, 3 MPa, 5 MPa, 7 MPa, 8 MPa, 10 MPa, or any two of the foregoing, further, 1 MPa to 3 MPa.

[0126] For experimental parameters not specified in the following specific embodiments, please refer to the guidelines given in this application, or consult experimental manuals or other experimental methods known in the art, or refer to the experimental conditions recommended by the manufacturer; unless otherwise specified, the experimental methods are known methods. The compounds in the embodiments were characterized using a nuclear magnetic resonance spectrometer (Brucker ARX-400); "eq" in the preparation method represents molar equivalent, for example, 1eq represents 1 molar equivalent.

[0127] Unless otherwise specified, all concentrations mentioned in the following examples are molar concentrations. The raw materials and reagents used are commercially available or can be prepared by those skilled in the art using known methods. The main sources are as follows:

[0128] 2,5-Di-tert-butyl-6-bromophenol: AR, Innochem;

[0129] 2,5-Di-tert-butyl-6-(hydroxytetrahydropyran)phenol: AR, Innochem;

[0130] n-Butyllithium: AR, Innochem;

[0131] Iodomethane: AR, Innochem;

[0132] 1,2-Dibromomethane: AR, Innochem;

[0133] Ultra-dry tetrahydrofuran: AR, Innochem;

[0134] Anhydrous cesium carbonate: AR, Innochem;

[0135] Anhydrous potassium hydroxide: AR, Innochem;

[0136] Triethylamine: AR, Innochem;

[0137] Anhydrous methanol: AR, Innochem;

[0138] Anhydrous tetrahydrofuran: AR, Innochem;

[0139] Ultra-dry toluene: AR, Innochem;

[0140] Ultra-dry n-hexane: AR, Innochem;

[0141] Petroleum ether: 60–90 °C, Beijing Chemical Reagent Company;

[0142] Silica gel: AR, 200-300 mesh, Shanghai Wusi Chemical Reagent Company;

[0143] Deuterated chloroform: AR, Acros;

[0144] Industrial alcohol: 95%, Beijing Chemical Reagent Company;

[0145] ZrCl4(THF)2: Tokyo Chemical Industry Co., Ltd.;

[0146] HfCl4(THF)2: Tokyo Chemical Industry Co., Ltd.;

[0147] MAO (alkylaluminoxane), MMAO (modified alkylaluminoxane): 10wt% toluene solution, Albemarle;

[0148] Ethylene: 99.9% Beijing Yanshan Chemical Co., Ltd.

[0149] 1-Octenene: 98%, Beijing Innocare Technology Co., Ltd.;

[0150] High-purity nitrogen: Beijing Shunan Qite Gas Co., Ltd.;

[0151] Liquid nitrogen: Beijing Shunan Qite Gas Co., Ltd.;

[0152] Isopar E: ExxonMobil.

[0153] In the examples below, the compounds were synthesized according to the reaction equations below. It can be understood that, as needed, the products of each step can be prepared in multiple batches using the same method, and then combined for the next reaction:

[0154]

[0155] The following examples illustrate the catalyst synthesis using compounds 6 (where M is Zr) and 9 (where M is Zr):

[0156] (1) Preparation of compound 1:

[0157] 10 g (0.04 mol, 1 eq) of 2,5-di-tert-butyl-6-bromophenol and 8 g (0.04 mol, 1 eq) of 2,5-di-tert-butyl-6-(hydroxytetrahydropyran)phenol were dissolved in 200 mL of ultra-dry acetonitrile. Potassium hydroxide (6.7 g, 0.12 mol, 3 eq) was added at room temperature, followed by dropwise addition of 1,2-dibromomethane (3.5 g, 0.02 mol, 0.5 eq). The reaction was carried out at 80 °C for 2 h. After slowly returning to room temperature, 100.0 mL of water was added to quench the reaction mixture. The solution was concentrated by rotary evaporation, extracted with ethyl acetate, and then recrystallized from n-hexane and washed to give 10 g of a white solid, with a yield of 50.1%.

[0158] The NMR structure confirmation data of compound 1 is shown below:

[0159] 1 H NMR (500 MHz, Chloroform ) δ 7.42 (s, 2H), 7.27 (s, 2H), 7.16 (s,2H), 6.84 (s, 2H), 6.20 (s, 4H), 5.39 (s, 2H), 3.74 (s, 1H), 3.64 (s, 1H),2.04 (s, 1H), 1.78 (s, 1H), 1.74 (s, 3H), 1.64 (s, 1H), 1.57 (d, J = 15.0 Hz,4H), 1.40 (s, 36H), 1.32 (s, 18H), 1.27 (s, 18H).

[0160] (2) Preparation of compound 2:

[0161] Compound 1 (10 g, 0.017 mol, 1 eq) and compound 11 (8.4 g, 0.017 mol, 1 eq) were dissolved in 200 mL of a tetrahydrofuran:water mixture (4:1). Potassium hydroxide (2.9 g, 0.051 mol, 3 eq) was added at room temperature, followed by XphosPd G3 (14 mg, 0.001 eq). The reaction was carried out at 80 °C for 2 h. After slowly restoring to room temperature, the reaction mixture was quenched with 100.0 mL of water. The reaction solution was concentrated by rotary evaporation, extracted with ethyl acetate, and then recrystallized from n-hexane and washed to give 5 g of a white solid, with a yield of 25.6%.

[0162] The NMR structure confirmation data of compound 2 are shown below:

[0163] 1 H NMR (500 MHz, Chloroform ) δ 7.73 (s, 1H), 7.58 (s, 1H), 7.39 (s,1H), 7.25 (s, 2H), 7.16 (s, 1H), 6.97 (s, 1H), 6.84 (s, 1H), 6.12 (s, 2H), 5.41 (s, 1H), 4.11 (s, 1H), 1.76 (d, J = 20.0 Hz, 2H), 1.57 (d, J = 15.0 Hz, 2H), 1.53 – 1.20 (m, 82H).

[0164] (3) Preparation of compound 3:

[0165] Compound 2 (10 g, 0.010 mol, 1 eq) was dissolved in 100 mL of tetrahydrofuran. Triethylamine (2.1 g, 0.020 mol, 2 eq) was added dropwise at 0 °C, and the reaction was maintained at this temperature for 0.5 h. Then, iodomethane (1.6 g, 0.011 mol, 1.1 eq) was added dropwise, and the reaction was stopped at 80 °C for 2 h. After slowly restoring to room temperature, 100.0 mL of water was added to quench the reaction. The reaction solution was concentrated by rotary evaporation, extracted with ethyl acetate, and then rotary evaporated. The solution was recrystallized from n-hexane and washed to give 5 g of gray solid, with a yield of 49.5%.

[0166] The NMR structure confirmation data for compound 3 is shown below:

[0167] 1H NMR (500 MHz, Chloroform ) δ 7.73 (s, 1H), 7.58 (s, 1H), 7.39 (s,1H), 7.25 (s, 2H), 7.16 (s, 1H), 6.97 (s, 1H), 6.84 (s, 1H), 6.05 (s, 2H), 4.98 (s, 1H), 3.74 (s, 1H), 3.20 (s, 3H), 1.74 (s, 1H), 1.57 (d, J = 15.0 Hz, 2H), 1.53 – 1.29 (m, 81H).

[0168] (4) Preparation of compound 4:

[0169] Compound 3 (10 g, 0.010 mol, 1 eq) was dissolved in 100 mL of methanol. 5 mL of 0.1 M dilute hydrochloric acid was added dropwise at 0 °C, and the reaction was allowed to proceed for 2 h at 80 °C until completion. After slowly returning to room temperature, 100.0 mL of water was added to quench the reaction mixture. The solution was concentrated by rotary evaporation, extracted with ethyl acetate, and then rotary evaporated again. The solution was recrystallized from n-hexane and washed to give 8 g of a white solid, with a yield of 85%.

[0170] The NMR structure confirmation data of compound 4 are shown below:

[0171] 1 H NMR (500 MHz, Chloroform ) δ 7.73 (s, 1H), 7.58 (s, 1H), 7.39 (s,1H), 7.25 (s, 2H), 7.16 (s, 1H), 6.97 (s, 1H), 6.84 (s, 1H), 6.05 (s, 2H), 4.98 (s, 1H), 3.74 (s, 1H), 3.20 (s, 3H), 1.74 (s, 1H), 1.57 (d, J = 15.0 Hz, 2H), 1.53 – 1.29 (m, 81H).

[0172] (5) Preparation of compound 6:

[0173] In a glove box, 5 g of compound 4 (5 g, 0.006 mol, 1 eq) was dissolved in 50 mL of dry toluene, and then ZrCl4 (1.4 g, 0.006 mol, 1.1 eq) was added. The mixture was heated to 90 °C and refluxed for 4 h. After the reaction was completed, the toluene was dried under vacuum, 15 mL of dry n-hexane was added, the mixture was stirred for 15 min, allowed to stand, filtered, and washed with dry n-hexane. The filtrate was dried under vacuum, and then 20 mL of dry toluene was added. The filtrate was filtered and collected. After the solvent was dried under vacuum, 2.5 g of white solid was obtained, with a yield of 48.62%.

[0174] The NMR structure confirmation data of compound 6 is shown below:

[0175] 1 H NMR (500 MHz, Chloroform ) δ 7.73 (s, 1H), 7.58 (s, 1H), 7.39 (s,1H), 7.25 (s, 2H), 7.16 (s, 1H), 6.97 (s, 1H), 6.84 (s, 1H), 6.05 (s, 2H), 4.98 (s, 1H), 3.74 (s, 1H), 3.20 (s, 3H), 1.74 (s, 1H), 1.57 (d, J = 15.0 Hz, 2H), 1.53 – 1.29 (m, 81H).

[0176] (6) Preparation of compound 9:

[0177] In a glove box, 2.5 g of catalyst 6 (2.5 g, 0.0025 mol, 1.0 eq) was dissolved in 40 mL of dry toluene. A 3 mol / L toluene solution of methyl magnesium bromide (0.66 mL, 0.005 mol, 2.0 eq) was slowly added dropwise. The reaction was carried out at 25 °C for 3 h. The mixture was then filtered and the filtrate was collected. After removing the solvent, 1.5 g of white solid was obtained, with a yield of 62.3%.

[0178] The NMR structure confirmation data of compound 9 are shown below:

[0179] 1H NMR (500 MHz, Chloroform ) δ 7.73 (s, 1H), 7.58 (s, 1H), 7.39 (s,1H), 7.25 (s, 2H), 7.16 (s, 1H), 6.97 (s, 1H), 6.84 (s, 1H), 6.05 (s, 2H), 4.98 (s, 1H), 3.74 (s, 1H), 3.20 (s, 3H), 1.74 (s, 1H), 1.57 (d, J = 15.0 Hz, 2H), 1.53 – 1.29 (m, 81H) , -0.2 – -0.1 (s, 6H).

[0180] The synthesis methods of compounds 5 and 7 are similar to those of compound 6; the synthesis methods of compounds 8 and 10 are similar to those of compound 9.

[0181] The synthesis methods of compounds 11-15 are similar to those of compound 6, with the main difference being the modification of different substituents. The specific structures are shown in Table 1 below.

[0182] Table 1

[0183]

[0184] Comparative compound 1

[0185] Using existing complexes, the structure shown below (M is Hf, X is -CH2-CH3), was prepared according to the description in CN111747976A:

[0186] .

[0187] Comparative compound 2

[0188] Using existing complexes, the structure of which is shown below (M is Zr), it was prepared according to the description in CN117866003A:

[0189] .

[0190] Application Example 1

[0191] A 1L high-pressure reactor, equipped with a weighed ampoule containing 1 μmol of catalyst (compound 5), a temperature sensor, a reflux evaporator, and a mechanical stirrer, was continuously dried at 160°C for 1 hour. The reactor was then evacuated and gradually cooled to 25°C. 50 mL of 0.002 mol / L MMAO-7 (0.1 mmol) diluted in Isopar E and 150 mL of 1-octene were added. The temperature was then raised to 140°C, and ethylene monomer at 3.0 MPa was introduced. The ampoule was then broken, and the polymerization reaction began. Throughout the polymerization process, the stirring rate, polymerization temperature, and ethylene pressure remained constant. After 5 minutes, the gas inside the reactor was purged, nitrogen was used for purging, ethanol was added to precipitate the solid, and the polymer was vacuum-dried to constant weight. 35 g of polymer was obtained.

[0192] Application Example 2

[0193] The polymerization steps were the same as in Application Example 1, the main difference being that compound 5 was replaced by compound 6 as a catalyst in an equal amount. 90g of polymer was obtained.

[0194] Application Example 3

[0195] The polymerization steps were the same as in Application Example 1, the main difference being that compound 5 was replaced by compound 7 as a catalyst in an equal amount. 60g of polymer was obtained.

[0196] Application Example 4

[0197] The polymerization steps were the same as in Application Example 1, with the main difference being: compound 5 was replaced by compound 8 as the catalyst in an equal amount; the Isopar E dilution of MMAO-7 was 25 mL with a concentration of 0.002 mol / L; the temperature reached was 160 °C; and the pressure of the ethylene monomer introduced was 4.0 MPa. 30 g of polymer was obtained.

[0198] Application Example 5

[0199] The polymerization steps are the same as in Application Example 4, the main difference being that compound 8 is replaced by compound 9 as a catalyst in an equal amount to obtain 70g of polymer.

[0200] Application Example 6

[0201] The polymerization steps were the same as in Application Example 4, except that compound 8 was replaced by compound 10 as a catalyst in equal amounts, resulting in 58.2g of polymer.

[0202] Application Example 7

[0203] The polymerization steps were the same as in Application Example 1, except that compound 5 was replaced by compound 11 in an equal amount as a catalyst to obtain 26 g of polymer.

[0204] Application Example 8

[0205] The polymerization steps were the same as in Application Example 1, except that compound 5 was replaced by compound 12 as a catalyst in equal amounts to obtain 29 g of polymer.

[0206] Application Example 9

[0207] The polymerization steps were the same as in Application Example 1, except that compound 5 was replaced by compound 13 as a catalyst in equal amounts to obtain 28 g of polymer.

[0208] Application Example 10

[0209] The polymerization steps were the same as in Application Example 1, except that compound 5 was replaced by compound 14 in an equal amount as a catalyst to obtain 26g of polymer.

[0210] Application Example 11

[0211] The polymerization steps were the same as in Application Example 1, except that compound 5 was replaced by compound 15 as a catalyst in an equal amount, resulting in 29 g of polymer.

[0212] Comparative Application Example 1

[0213] The polymerization steps are the same as in Application Example 1, the main difference being that: Compound 5 is replaced by Comparative Compound 1 in an equal amount as the catalyst.

[0214] Comparative Application Example 2

[0215] The polymerization steps are the same as in Application Example 1, the main difference being that compound 5 is replaced by a comparative compound 2 in equal amounts as the catalyst.

[0216] Test example:

[0217] (1) The copolymerization activity of the polymers is calculated according to the following formula:

[0218] Copolymerization activity = polymer mass / (metal content in catalyst * polymerization time);

[0219] (2) The weight-average molecular weight Mw of the polymer was obtained by testing with PL-GPC220 at 150℃ using three PLgel 10 µm MIXED-B separation columns in series, with 1,2,4-trichlorobenzene as the solvent.

[0220] (3) The polymer dispersibility index (PDI) was measured by GPC-FTIR;

[0221] (4) The melting point Tm of the polymer was determined by DSC (Q2000) method.

[0222] The performance test results of the polyolefin products prepared in each embodiment and comparative example are shown in Table 2 below:

[0223] Table 2

[0224]

[0225] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0226] The embodiments described above are merely illustrative of several implementation methods of this application, intended to facilitate a detailed understanding of the technical solutions of this application, but should not be construed as limiting the scope of protection of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the scope of protection of this application. It should be understood that technical solutions obtained by those skilled in the art based on the technical solutions provided in this application through logical analysis, reasoning, or limited experimentation are all within the scope of protection of the appended claims. Therefore, the scope of protection of this patent application should be determined by the content of the appended claims, and the specification can be used to interpret the content of the claims.

Claims

1. A metal-organic complex having the structural features shown in Formula I: Equation I R1, R3, R5, R7, R9, R 11 R 13 R 15 R 17 Independently, they are: H, C1~C10 alkyl or C6~C14 aryl groups substituted with C1~C10 alkyl; X1, X2, and X3 are independently monovalent ligand groups; M is a group IVB metal element.

2. The organometallic complex according to claim 1, characterized in that, R1, R3, R5, R7, R9, R 11 R 13 R 15 R 17 Each of the following is independently: a phenyl group consisting of C1-C6 alkyl or C1-C6 alkyl-substituted alkyl groups.

3. The organometallic complex according to claim 2, characterized in that, R1, R3, R5, R7, R9, R 11 R 13 R 15 R 17 Each of the following is independently: a C1-C4 alkyl or a C1-C4 alkyl-substituted phenyl group.

4. The organometallic complex according to any one of claims 1 to 3, characterized in that, X1, X2, and X3 are independently of each other: halogen, C1-C3 alkyl, or benzyl; optionally, X1, X2, and X3 are independently of each other: halogen or C1-C3 alkyl; further optionally, X1, X2, and X3 are independently of each other: halogen.

5. The organometallic complex according to any one of claims 1 to 3, characterized in that, M is titanium, zirconium, or hafnium; optionally, M is zirconium or hafnium; further optionally, M is zirconium.

6. The method for preparing the organometallic complex according to any one of claims 1 to 5, characterized in that, Includes the following steps: The organometallic complex is prepared by complexing the compound shown in Formula II with the halide of M. Alternatively, the compound shown in Formula II is complexed with a halide of M, and the product of the complexation reaction is then reacted with Grignard reagent R-Mg-X to prepare the organometallic complex. Formula II X represents halogen; The definition of R is the same as that of X1, X2 or X3; optionally, R is a C1~C3 alkyl or benzyl.

7. The method for preparing the organometallic complex according to claim 6, characterized in that, It has one or more of the following characteristics: (1) The molar ratio of the compound shown in Formula II to the halide of M is 1:(0.5~1); (2) The molar ratio of the compound shown in Formula II to the halide of M and the Grignard reagent R-Mg-X is 1:(0.5~1):(2~2.3).

8. The method for preparing the organometallic complex according to claim 6 or 7, characterized in that, The method for preparing the compound shown in Formula II includes the following steps: Compounds shown in Formula III: ; Compounds shown in Formula IV: ; Compound shown in Formula V: ; Compound shown in Formula VIII: ; The compound shown in Formula VI: ; The compound shown in Formula VII: ; Compound V is prepared by reacting the compound shown in Formula III with the compound shown in Formula IV in the presence of an inorganic base and 1,2-dibromomethane. Compound V is prepared by reacting the compound shown in Formula VIII with the compound shown in Formula VIII in the presence of an inorganic base and a noble metal catalyst. The compound shown in formula VI is reacted with iodomethane in the presence of an organic base to prepare the compound shown in formula VII. In the presence of an inorganic acid, the compound shown in Formula VII is subjected to a deprotection reaction to prepare the compound shown in Formula II; Optionally, the method for preparing the compound shown in Formula II has one or more of the following features: (1) The molar ratio of the inorganic base to 1,2-dibromomethane used in the preparation of the compound shown in Formula III, the compound shown in Formula IV, and the compound shown in Formula V is 1:(0.8~1.2):(2~5):(0.4~0.6); (2) The molar ratio of inorganic base to noble metal catalyst used in the preparation of compounds shown in formula V, formula VIII, and formula VI is 1:(0.8~1.2):(2~5):(0.001~0.0015); (3) The molar ratio of the compound shown in Formula VI, the organic base and iodomethane is 1:(1.5~3):(1~1.5); (4) The molar ratio of the compound shown in formula VII to the inorganic acid is 1:(2~5); (5) The noble metal catalyst is palladium; (6) The inorganic base used in preparing the compound shown in formula V is one or more of cesium carbonate, sodium carbonate, potassium hydroxide, and sodium hydroxide; (7) The inorganic base used in preparing the compound shown in Formula VI is one or more of cesium carbonate, sodium carbonate, potassium hydroxide and sodium hydroxide.

9. The use of the organometallic complex according to any one of claims 1 to 5 as a catalyst in the preparation of polyolefins.

10. A method for preparing a polyolefin, characterized in that, Includes the following steps: In the presence of a catalyst, olefin monomers are polymerized to prepare polyolefins; the catalyst includes the organometallic complex according to any one of claims 1 to 5. Optionally, the olefin monomer includes ethylene and α-olefin; Optionally, the catalyst further includes a co-catalyst, which includes one or more of methylaluminoxane, ethylaluminoxane, and boron salt compounds; more preferably, the co-catalyst includes methylaluminoxane and ethylaluminoxane; even more preferably, the molar ratio of Al in the co-catalyst to M in the organometallic complex is 4 to 300.

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