Metal complex as well as preparation method and application thereof

Abstract

The invention relates to a metal complex as well as a preparation method and application thereof. The metal complex has a structure as shown in a formula II. The metal complex provided by the invention can strengthen protection on an active metal center, has high and durable catalytic activity, and can tolerate higher polymerization temperature, the thermal stability of the catalyst is obviously improved, and the service life is also greatly prolonged. The catalyst composition provided by the invention can be used for catalyzing polymerization of various olefins to generate corresponding copolymers with high comonomer content and high molecular weight, and can be used for producing polyolefin products such as high-performance binary and ethylene propylene diene monomer, polyolefin elastomers, cycloolefin copolymers and the like. # imgabs0 #

Description

Technical Field

[0001] The present invention belongs to the technical field of olefin polymerization catalysts, and particularly relates to a metal complex, a preparation method thereof and an application thereof. Background Art

[0002] In the field of olefin polymerization, catalysts play a crucial role, and their performance directly affects many key parameters such as the microstructure, molecular weight and stereoselectivity of the polymerization products, thus directly determining their performance. Metallocene catalysts have attracted wide attention in the academic and industrial fields due to their high catalytic activity, good controllability of polymer structure and excellent copolymerization performance.

[0003] At present, many types of metallocene catalysts have been reported, but due to the difficulties faced in the synthesis of metallocenes and the production process of polyolefins, few can meet the requirements of industrial plant production. For example, the polyolefin elastomer produced by copolymerizing ethylene and 1-octene using the constrained geometry configuration (CGC) single-metallocene titanium complex (European patent EP0416815A2) developed by The Dow Chemical Company in the United States has a relatively low molecular weight, and its highest weight-average molecular weight is only 160,000, and the mechanical strength cannot meet the requirements of many high-end applications.

[0004] CGC catalysts containing aryloxy side chains have diverse structures, and the ortho-substituents of aryloxy have an important influence on the catalytic performance of the catalysts. For example, the single-metallocene titanium catalyst with an ortho-H-containing aryloxy side chain reported in Organometallics 1997, 16, 5958-5963 can only catalyze ethylene polymerization with relatively low activity; by adjusting the substituents, such catalysts can catalyze ethylene homopolymerization and copolymerization with high activity to obtain copolymers with a high comonomer content; for example, the catalyst disclosed in the invention patent CN1068884C of Sumitomo Chemical Co., Ltd. can be used for the homopolymerization and copolymerization of ethylene, and the activity can reach 10 7 g mol -1 h -1 , but the molecular weight of the polymer is relatively low, not exceeding 12×10 4 g mol -1 . During the synthesis process, the establishment of the bridging structure in the ligand structure of such catalysts usually requires the use of high-cost and dangerous reagents such as n-butyllithium, which increases the difficulty of scale-up synthesis. At the same time, it is usually difficult to obtain polymers with relatively high molecular weights or to be applicable to high-temperature polymerization for such catalysts.

[0005] In summary, although the above-known catalysts show excellent performance in some aspects, there are certain defects in the synthesis and catalytic olefin polymerization. Therefore, in the field of polyolefin products, there is still a need to develop catalysts with the characteristics of low cost, high catalytic activity, high selectivity, and certain copolymerization performance, which are suitable for preparing polyolefins by high-temperature solution polymerization. Summary of the Invention

[0006] To overcome the above-mentioned defects existing in the prior art, an object of the present invention is to provide a metal complex. The synthetic route of such complexes is simple, the bridging group can be constructed at low cost, and the polymerization of olefins can be catalyzed with high activity and selectivity to obtain polymers with high molecular weight and comonomer content.

[0007] Another object of the present invention is to provide a preparation method of the metal complex.

[0008] Another object of the present invention is to provide the use of the metal complex in the catalysis of olefin polymerization.

[0009] Another object of the present invention is to provide a polymerization method of ethylene.

[0010] To achieve the above objects, the present invention adopts the following technical solutions:

[0011] In the first aspect, the present invention provides a ligand precursor compound having the structural formula shown in Formula I below:

[0012]

[0013] In Formula I,

[0014] Cp’ is a substituted or unsubstituted cyclopentadienyl group, a substituted or unsubstituted indenyl group, or a substituted or unsubstituted benzoindenyl group. In the case of being substituted, the substituents are selected from the group consisting of C1-C30 alkyl groups, C1-C30 alkyl groups substituted with amino groups, 5-6 membered heterocyclic groups containing N heteroatoms, C6-C30 aryl groups, and C7-C30 aralkyl groups, and the aralkyl groups may optionally be further substituted with halogens or C1-C30 alkyl groups;

[0015] Y is CR 5 or N,

[0016] R 5 is selected from H, C1-C30 alkyl groups, C6-C30 aryl groups, and C7-C30 aralkyl groups;

[0017] R 1 and R 2 are each independently selected from C1-C30 alkyl groups, C3-C30 cycloalkyl groups, substituted or unsubstituted C6-C30 aryl groups, substituted or unsubstituted C7-C30 aralkyl groups, and substituted or unsubstituted C5-C30 monocyclic or fused heteroaryl groups containing N heteroatoms, and the substitution means that they can be substituted with C1-C30 alkyl groups, C3-C30 cycloalkyl groups, C6-C30 aryl groups, C7-C30 aralkyl groups, C2-C30 dialkylamino groups, or C3-C30 silyl groups;

[0018] R3 and R 4 are each independently H, a C1-C30 alkyl group, a C6-C30 aryl group, a C7-C30 aralkyl group, or R 3 , R 4 and the carbon atom to which it is attached together form a cyclic structure.

[0019] In a specific embodiment, the ligand precursor compound of formula I can be represented by the following formula I-1:

[0020]

[0021] In the above formula I-1, R 6 -R 9 are each independently H, a C1-C30 alkyl group, a C6-C30 aryl group, a C7-C30 aralkyl group, and the remaining substituents are as defined above.

[0022] In a specific embodiment, the ligand precursor compound of formula I-1 can further be represented by the following formula I-1-1 or I-1-2:

[0023]

[0024] In the above formulas I-1-1 and I-1-2, each substituent is as defined above.

[0025] In a specific embodiment, the ligand precursor compound of formula I can be represented by the following formula I-2:

[0026]

[0027] In the above formula I-2, R 3 and R 4 are each independently H, a C1-C30 alkyl group, a C6-C30 aryl group, a C7-C30 aralkyl group, and the remaining substituents are as defined above.

[0028] In a specific embodiment, the ligand precursor compound of formula I-2 can further be represented by the following formula I-2-1 or I-2-2:

[0029]

[0030] In the above formulas I-1-1 and I-1-2, R 3 and R 4 are each independently H, a C1-C30 alkyl group, a C6-C30 aryl group, a C7-C30 aralkyl group, and the remaining substituents are as defined above.

[0031] In a specific embodiment, in the above formulas,

[0032] Cp' can be selected from cyclopentadienyl, monomethylcyclopentadienyl, dimethylcyclopentadienyl, trimethylcyclopentadienyl, tetramethylcyclopentadienyl, methylethylcyclopentadienyl, methylpropylcyclopentadienyl, methylbutylcyclopentadienyl, dimethyldiphenylcyclopentadienyl, diphenylcyclopentadienyl, indenyl, monomethylindenyl, dimethylindenyl, benzindenyl, 2-methylbenzindenyl, 3-dimethylaminoindenyl, 3-diethylaminoindenyl, 3-pyrrolidinylindenyl, 3-piperidinylindenyl, 2-methyl-4-phenylindenyl, 2-benzylindenyl, 2-p-methylbenzylindenyl, 2-p-fluorobenzylindenyl, etc.;

[0033] R 1 and R 2 can be selected from ethyl, n-propyl, isopropyl, n-butyl, 2-butyl, isobutyl, tert-butyl, n-pentyl, 2-pentyl, 3-pentyl, isopentyl, tert-pentyl, n-hexyl, 2-hexyl, 3-hexyl, isohexyl, tert-hexyl, n-heptyl, 2-heptyl, 3-heptyl, 4-heptyl, isoheptyl, tert-heptyl, n-octyl and various isomeric octyls, n-nonyl and various isomeric nonyls, n-decyl and various isomeric decyls, adamantyl (Ad), phenyl, naphthyl, anthracenyl, phenyl substituted by halogen or C1-C6 alkyl or phenyl, naphthyl substituted by halogen or C1-C6 alkyl or phenyl, anthracenyl substituted by halogen or C1-C6 alkyl or phenyl, C1-C6 alkyl substituted by phenyl or tolyl, carbazolyl, carbazolyl substituted by C1-C6 alkyl;

[0034] R 3 and R 4 are each independently H, C1-C30 alkyl, C6-C30 aryl, C7-C30 aralkyl;

[0035] R 5 -R 9 can be H, C1-C30 alkyl, C6-C30 aryl, C7-C30 aralkyl.

[0036] In specific embodiments, in the above formulas,

[0037] Cp' can be selected from tetramethylcyclopentadienyl, indenyl, indenyl substituted by methyl or phenyl;

[0038] R 1 can be selected from tert-butyl, wherein, R 10 -R 12 are each independently selected from C1-C5 alkyl, C6-C20 aryl, C7-C20 alkylaryl, R 13 and R 14 are each independently selected from H or C1-C6 alkyl;

[0039] R 2is tert-butyl;

[0040] R 3 and R 4 are each independently H, a C1-C30 alkyl group, a C6-C30 aryl group, or a C7-C30 aralkyl group;

[0041] R 5 -R 9 can be H, a C1-C30 alkyl group, a C6-C30 aryl group, or a C7-C30 aralkyl group.

[0042] In a specific embodiment, the ligand precursor compound is selected from the following:

[0043]

[0044]

[0045] In a second aspect, the present invention provides a metal complex formed from the above ligand precursor compound, which is represented by the following formula II:

[0046]

[0047] In formula II, M is titanium, zirconium, or hafnium;

[0048] X is each independently selected from halogen, a C1-C30 alkyl group, a C1-C30 alkoxy group, a dialkylamino group, a C6-C20 aryl group, or a C7-C30 aralkyl group;

[0049] The definitions of the other substituents are as defined in the general formula I above, respectively.

[0050] In a specific embodiment, the metal complex of formula II can be represented by formula II-1 or II-2:

[0051]

[0052]

[0053] In a specific embodiment, the metal complex of formula II-1 can further be represented by formula II-1-1 or II-1-2:

[0054]

[0055]

[0056] In a specific embodiment, the metal complex of formula II-2 can further be represented by formula II-2-1 or II-2-2:

[0057]

[0058] Among them, in each of the general formulas representing the metal complexes above, except for R in Formulas II-2, II-2-1, and II-2-2 3 and R 4 which are each independently H, C1-C30 alkyl, C6-C30 aryl, or C7-C30 aralkyl, the remaining substituents are as defined above respectively.

[0059] In a specific embodiment, the metal complex is selected from the following:

[0060]

[0061]

[0062] In a third aspect, a method for preparing the metal complex described in the second aspect of the present invention is provided, and the method includes the following steps:

[0063]

[0064] In the above reaction route, X' represents a halogen, and the definitions of other substituents are as defined above respectively,

[0065] 1) The compound of Formula 1 reacts with the compound of Formula 2 in the presence of a base to obtain an intermediate product 3;

[0066] 2) Under an inert atmosphere, the aforementioned intermediate product 3 is successively reacted with n-butyllithium, (substituted) cyclopentenone or (substituted) indanone, and then dehydrated under acidic conditions to obtain a ligand precursor compound 4;

[0067] 3) Under anhydrous and anaerobic conditions, an alkyllithium is added to the ligand precursor compound of Formula 4 to form a dilithium salt of the ligand precursor compound, and then a metal precursor compound MX4 where X is a halogen is added to react to form a metal complex where X is a halogen, or,

[0068] An alkyllithium or a Grignard reagent RM' is added to the aforementioned metal complex where X is a halogen to obtain a corresponding dialkyl-, aryl-, or aralkyl-substituted metal complex,

[0069] Or,

[0070] Under anhydrous and anaerobic conditions, in a toluene solvent, the ligand precursor compound shown in Formula 4 directly reacts with a metal precursor compound MX4 where X is an alkyl, aralkyl, or dialkylamino group to form a metal complex,

[0071] Among them, the metal precursor compound can be a metal dialkylamidate, a metal halide, a metal alkoxide, a metal dibenzyldihalide, or a metal bis(trimethylsilylmethyl)dihalide, and the metal in the metal precursor compound is selected from titanium, zirconium, or hafnium.

[0072] It should be noted that the synthesis of the metal complex is not limited to the aforementioned synthesis method, and those skilled in the art can synthesize the metal complex by different methods according to the existing chemical knowledge.

[0073] Fourthly, the present invention also provides the use of the metal complex described in the second aspect in the catalytic olefin polymerization.

[0074] In the specific embodiments, the olefin polymerization can be ethylene homopolymerization, copolymerization of ethylene and α-olefin, copolymerization of propylene and α-olefin, copolymerization of ethylene and cycloolefin, copolymerization of propylene and cycloolefin, or terpolymerization of ethylene, propylene and cycloolefin.

[0075] Fifthly, the present invention also provides a catalyst composition, which comprises:

[0076] i. the metal complex described in the second aspect as the main catalyst, and

[0077] ii. a cocatalyst selected from alkylaluminoxane or modified alkylaluminoxane or a composite system of alkylaluminum / organic boron compound or a composite system of alkylaluminum chloride / organic boron compound.

[0078] In the specific embodiments, the alkylaluminoxane can be common types in the art. In some preferred embodiments, the alkylaluminoxane includes but is not limited to methylaluminoxane (MAO), etc.

[0079] In the specific embodiments, the modified alkylaluminoxane can be common types in the art. In some preferred embodiments, the modified aluminoxane includes but is not limited to modified methylaluminoxane (MMAO), etc.

[0080] In the specific embodiments, the alkylaluminum can be common types in the art. In some preferred embodiments, the alkylaluminum includes but is not limited to trimethylaluminum, triethylaluminum, triisobutylaluminum, etc., and preferably triisobutylaluminum.

[0081] In the specific embodiments, the alkylaluminum chloride can be common types in the art. In some preferred embodiments, the alkylaluminum chloride includes but is not limited to diethylaluminum chloride, sesquialteraluminum chloride, etc.

[0082] In the specific embodiments, the organoboron compounds can be common types in the art. In some preferred embodiments, the organoboron compounds include, but are not limited to, Ph3CB(C6F5)4, B(C6F5)3, Me3OB(C6F5)4, Ph3CB[C6H3(CF3)2]4, B[C6H3(CF3)2]3, Me3OB[C6H3(CF3)2]4, and PhR a 2HNB(C6F5)4 and PhR a 2HNB[C6H3(CF3)2]4, where R a is a C1-C18 alkyl group. In some more preferred embodiments, the organoboron compound can be Ph3CB(C6F5)4 or PhMe2HNB(C6F5)4.

[0083] In the specific embodiments, when the cocatalyst is methylaluminoxane (MAO), the molar ratio of aluminum in the cocatalyst to the metal in the main catalyst is 5-10000:1. In some preferred embodiments, the molar ratio of Al to metal M can be 100-2000:1; in some more preferred embodiments, the molar ratio of Al to metal M can be 1000-1500:1.

[0084] In the specific embodiments, when the cocatalyst is an alkylaluminum / organoboron compound composite system or an alkylaluminum chloride / organoboron compound composite system, the molar ratio of aluminum in the cocatalyst to the metal in the main catalyst is 5-10000:1. In some preferred embodiments, the molar ratio of Al to metal M can be 50-150:1; in some more preferred embodiments, the molar ratio of Al to metal M can be 50-75:1. The molar ratio of boron in the cocatalyst to the metal in the main catalyst is 1-2:1.

[0085] Sixthly, the present invention also provides a method for polymerizing ethylene, which includes catalyzing olefin polymerization in the presence of the catalyst composition of the fifth aspect above.

[0086] In the specific embodiments, the olefin polymerization includes: homopolymerization of ethylene, copolymerization of ethylene and α-olefin, copolymerization of propylene and α-olefin, copolymerization of ethylene and cycloolefin, copolymerization of propylene and cycloolefin, or terpolymerization of ethylene, propylene and cycloolefin.

[0087] In some embodiments, the α-olefin used as a comonomer can be common types in the art and can be a C3-C12 α-olefin. In some preferred embodiments, the α-olefin can be 1-propene, 1-butene, 1-pentene, 1-hexene, 1-heptene or 1-octene.

[0088] In the specific embodiments, the cycloolefins used as comonomers can be common types in the art, and the cycloolefins can be cyclopentadiene, norbornene, ethylidene norbornene, dicyclopentadiene and other cycloolefins.

[0089] In the polymerization method provided by the present invention, the polymerization temperature in the polymerization reaction (including homopolymerization and copolymerization) can be 0 to 200 °C. In some preferred embodiments, the polymerization temperature can be 100 to 180 °C. In some more preferred embodiments, the polymerization temperature can be 120 to 180 °C, such as 120 °C, 130 °C, 140 °C, 150 °C, 160 °C, 170 °C, 180 °C.

[0090] In the polymerization method provided by the present invention, the pressure of the ethylene monomer in the polymerization reaction can be 0.05 to 5 MPa. In some preferred embodiments, the ethylene monomer pressure can be 0.1 to 1 MPa.

[0091] In the polymerization method provided by the present invention, other process conditions except the above process parameters can be conventional process parameters, or can be appropriately adjusted by those skilled in the art according to the actual reaction conditions such as the polymerization type.

[0092] Beneficial effects

[0093] The metal complex provided by the present invention and the ethylene polymerization method using the same as a polymerization catalyst have the following advantages:

[0094] (1) The structure of the metal complex of the present invention can strengthen the protection of the active metal center, has high and persistent catalytic activity, can withstand higher polymerization temperatures, the thermal stability of the catalyst is significantly improved, and the service life is also greatly extended.

[0095] (2) The metal complex of the present invention can not only catalyze the homopolymerization of ethylene, but also catalyze the copolymerization of ethylene with α-olefins such as propylene, 1-butene, 1-hexene, 1-octene, 1-decene and cycloolefins such as norbornene, ethylidene norbornene, dicyclopentadiene with high activity, to generate corresponding copolymers with high comonomer content and high molecular weight, which can be used to produce polyolefin products such as high-performance binary and ternary ethylene-propylene rubbers, polyolefin elastomers, cycloolefin copolymers, etc. The substrate applicability is wider, the types of polymerization products are more, and thus the application fields are also wider.

[0096] (3) The preparation method of the metal complex of the present invention is simple, does not require complex process steps and high costs, and can adapt to large-scale production and use.

[0097] In summary, the metal complex and the ethylene polymerization method of the present invention can significantly improve the catalytic activity and service life of the catalyst, and are suitable for a variety of polymerization processes, can improve the production efficiency and product quality of ethylene polymers, and have broad prospects for large-scale industrial applications. Detailed implementation manners

[0098] The present invention will be further described in detail below in conjunction with specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but do not limit the present invention in any form. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can be made. These all belong to the protection scope of the present invention.

[0099] Terms

[0100] The numerical ranges in this application refer to those that include the endpoints of the range and any values between its two endpoints. For example, C1-C30 can represent C1, C2, C3, C4, C5, C6, C7, C8, C9, C10, C11, C12, C13, C14, C15, C16, C17, C18, C19, C20, C21, C22, C23, C24, C25, C26, C27, C28, C29 or C30, and other ranges can be understood and interpreted similarly.

[0101] Unless otherwise specified, the experimental methods used in the following examples are all conventional methods. Most of the chemical reagents and materials used can be obtained commercially, and individual chemical reagents are synthesized according to the literature methods.

[0102] Example 1: Preparation of ligand precursor compounds L1-L18

[0103] Under an ice-water bath, NaH (0.22 g, 8.97 mmol, 1.12 equiv) was added portionwise to a solution of (substituted)-2-bromo-1H-pyrrole or (substituted)-2-bromo-1H-indole (8.15 mmol) in DMF (20 ml). After completion, the system was warmed to room temperature and stirred for 1 hour, and then a solution of 2-(bromomethyl)-4-R 2 -6-R 1 -phenol in DMF (5 mL) was added dropwise to the above-mentioned system. After the resulting mixed system was stirred at room temperature for 12 hours, it was quenched with 30 mL of saturated NH4Cl aqueous solution and extracted with ethyl acetate (50 mL×3). The organic phase was dried over MgSO4 and filtered, and the filtrate was evaporated under reduced pressure to remove the volatiles. The resulting crude product could be directly used for the next reaction.

[0104] Under an inert atmosphere, the anhydrous methyl tert-butyl ether solution (100 mL) of the product from the previous step (5.00 mmol) was cooled in an ice-water bath, and n-BuLi (11.00 mmol, 4.58 mL, 2.4 M / L in n-hexane) was added dropwise thereto. After the addition was completed, the mixture was kept warm for 30 minutes, then heated to room temperature and stirred for 2 hours. The temperature of the reaction system was lowered to 0 °C, and after completion, stirring was continued at room temperature for 3 hours. The aforementioned reaction system was cooled in an ice-water bath, and an anhydrous methyl tert-butyl ether solution (5 mL) of (substituted) cyclopentenone or (substituted) indanone (5.00 mmol) was slowly added dropwise thereto. After the addition was completed, the resulting solution was heated to room temperature and stirred overnight. The reaction was quenched with a saturated NH4Cl aqueous solution (30 mL), the organic layer was separated, treated with concentrated hydrochloric acid (30 mL), neutralized with a saturated sodium carbonate solution, and then washed with water (3 × 60 mL), dried over MgSO4, filtered, the solvent was removed under vacuum, and the residue was eluted by silica gel column chromatography using petroleum ether and ethyl acetate (v / v, 50:1) as the eluent to obtain the corresponding ligand precursor compound.

[0105] Example 2: Preparation of Ligand Precursor Compounds L19 - L24

[0106] Under an ice-water bath, NaH (0.22 g, 8.97 mmol, 1.12 equiv) was added portionwise to a DMF (20 ml) solution of (substituted)-1H-imidazole or (substituted)-1H-benzimidazole (8.15 mmol). After completion, the system was heated to room temperature and stirred for 1 hour, and a DMF (5 mL) solution of 2-bromomethyl-4-R 2 -6-R 1 -phenol was added dropwise to the aforementioned system. After the resulting mixture was stirred at room temperature for 12 hours, it was quenched with 30 mL of a saturated NH4Cl aqueous solution and extracted with ethyl acetate (50 mL × 3). The organic phase was dried over MgSO4 and filtered, and the volatile components were removed from the filtrate under reduced pressure. The resulting crude product could be directly used in the next reaction.

[0107] Under an inert atmosphere, the anhydrous methyl tert-butyl ether solution (100 mL) of the product from the previous step (5.00 mmol) was cooled in an ice-water bath, and n-BuLi (11.00 mmol, 4.58 mL, 2.4 M / L in n-hexane) was added dropwise thereto. After the addition was completed, the mixture was kept warm for 30 minutes, then heated to room temperature and stirred for 2 hours. The temperature of the reaction system was lowered to 0 °C, and after completion, stirring was continued at room temperature for 3 hours. The aforementioned reaction system was cooled in an ice-water bath, and an anhydrous methyl tert-butyl ether solution (5 mL) of (substituted) cyclopentenone or (substituted) indanone (5.00 mmol) was slowly added dropwise thereto. After the addition was completed, the resulting solution was heated to room temperature and stirred overnight. The reaction was quenched with a saturated NH4Cl aqueous solution (30 mL), the organic layer was separated, treated with concentrated hydrochloric acid (30 mL), neutralized with a saturated sodium carbonate solution, and then washed with water (3 × 60 mL), dried over MgSO4, filtered, the solvent was removed under vacuum, and the residue was eluted by silica gel column chromatography using petroleum ether and ethyl acetate (v / v, 50:1) as the eluent to obtain the corresponding ligand precursor.

[0108] Among them, the structures of ligands L1-L24 are as follows:

[0109]

[0110]

[0111] Example 3: Synthesis of metal complexes C1-C24

[0112] Under an inert atmosphere, ligand precursors L1-L24 (5.00 mmol) were weighed into a 250 mL Schlenk flask, 100 mL of toluene was added, and a n-hexane solution of n-BuLi (4.00 mL, 10.00 mmol, 2.50 mol / L) was added at -30 °C. Subsequently, the mixture was heated to room temperature and stirred for 1 h. At room temperature, a toluene (30 mL) solution of titanium tetrachloride (0.95 g, 5.00 mmol) was slowly added to the resulting lithium salt solution of the ligand. The reaction mixture was stirred at room temperature for 1 h, and then reacted at 70 °C overnight. The generated precipitate was filtered off, the solvent in the filtrate was removed under vacuum to obtain the crude product, and the crude product was recrystallized with a dichloromethane / n-hexane mixed solvent to obtain the corresponding metal complexes C1-C24.

[0113] The corresponding relationship between the metal complexes and their corresponding ligand precursor compounds is as follows:

[0114] C1: L1; Yield 1.77 g, Yield rate, 61.8%. Elemental analysis (%): Found (Calculated) C, 67.17 (67.14); H, 6.85 (6.87); N, 2.43 (2.45).

[0115] C2: L2; Yield 1.87 g, yield rate 57.5%. Elemental analysis (%) : found (calculated) C, 70.13 (70.16); H, 6.99 (6.97); N, 2.14 (2.15).

[0116] C3: L3; Yield 1.93 g, yield rate 60.8%. Elemental analysis (%) : found (calculated) C, 70.01 (70.04); H, 6.54 (6.51); N, 2.23 (2.21).

[0117] C4: L4; Yield 2.23 g, yield rate 58.8%; Elemental analysis (%) : found (calculated) C, 74.36 (74.41); H, 6.01 (5.98); N, 1.83 (1.85).

[0118] C5: L5; Yield 2.37 g, yield rate 59.2%; Elemental analysis (%) : found (calculated) C, 75.05 (75.00); H, 6.40 (6.42); N, 1.73 (1.75).

[0119] C6: L6; Yield 2.13 g, yield rate 62.5%; Elemental analysis (%) : found (calculated) C, 70.53 (70.49); H, 5.60 (5.62); N, 4.09 (4.11).

[0120] C7: L7; Yield 2.37 g, yield rate 59.7%; Elemental analysis (%) : found (calculated) C, 72.60 (72.63); H, 6.89 (6.86); N, 3.55 (3.53).

[0121] C8: L8; Yield 1.76 g, yield rate 60.2%; Elemental analysis (%) : found (calculated) C, 67.86 (67.82); H, 6.71 (6.73); N, 2.38 (2.40).

[0122] C9: L9; Yield 2.08 g, yield rate 58.7%; Elemental analysis (%) : found (calculated) C, 72.85 (72.89); H, 6.14 (6.12); N, 1.99 (1.98).

[0123] C10: L10; Yield 2.30 g, yield rate 61.3%; Elemental analysis (%) : found (calculated) C, 73.63 (73.60); H, 6.56 (6.58); N, 1.85 (1.87).

[0124] C11: L11; Yield 2.01 g, Yield Rate 63.8%; Elemental Analysis (%) : Found (Calculated) C, 66.52 (68.48); H, 5.73 (5.75); N, 4.42 (4.44).

[0125] C12: L12; Yield 2.23 g, Yield Rate 59.97%; Elemental Analysis (%) : Found (Calculated) C, 71.03 (71.06); H, 7.07 (7.05); N, 3.78 (3.77).

[0126] C13: L13; Yield 2.22 g, Yield Rate 59.0%; Elemental Analysis (%) : Found (Calculated) C, 75.04 (75.01); H, 5.20 (5.22); N, 1.85 (1.86).

[0127] C14: L14; Yield 1.95 g, Yield Rate 55.5%; Elemental Analysis (%) : Found (Calculated) C, 73.55 (73.51); H, 5.29 (5.31); N, 1.98 (1.99).

[0128] C15: L15; Yield 2.16 g, Yield Rate 58.6%; Elemental Analysis (%) : Found (Calculated) C, 71.62 (71.65); H, 6.31 (6.29); N, 3.81 (3.80).

[0129] C16: L16; Yield 2.41 g, Yield Rate 61.2%; Elemental Analysis (%) : Found (Calculated) C, 73.16 (73.19); H, 6.16 (6.14); N, 3.58 (3.56).

[0130] C17: L17; Yield 2.54 g, Yield Rate 63.3%; Elemental Analysis (%) : Found (Calculated) C, 73.44 (73.41); H, 6.26 (6.29); N, 3.47 (3.49).

[0131] C18: L18; Yield 2.54 g, Yield Rate 58.8%; Elemental Analysis (%) : Found (Calculated) C, 75.06 (75.09); H, 6.10 (6.07); N, 3.22 (3.24).

[0132] C19: L19; Yield 1.79 g, Yield Rate 58.8%; Elemental Analysis (%) : Found (Calculated) C, 68.08 (68.04); H, 6.32 (6.34); N, 3.39 (4.41).

[0133] C20: L20; Output: 2.81 g, Yield: 70.8%; Elemental analysis (%) : Found (Calcd.) C, 71.06 (71.03); H, 6.70 (6.72); N, 5.27 (5.29).

[0134] C21: L21; Output: 1.67 g, Yield: 57.0%; Elemental analysis (%) : Found (Calcd.) C, 65.69 (65.65); H, 6.53 (6.54); N, 4.77 (4.79).

[0135] C22: L22; Output: 1.94 g, Yield: 55.3%; Elemental analysis (%) : Found (Calcd.) C, 68.34 (68.38); H, 6.48 (6.46); N, 6.00 (5.98).

[0136] C23: L23; Output: 1.58 g, Yield: 50.2%; Elemental analysis (%) : Found (Calcd.) C, 68.72 (68.69); H, 5.43 (5.44); N, 4.42 (4.45).

[0137] C24: L24; Output: 1.67 g, Yield: 57.6%; Elemental analysis (%) : Found (Calcd.) C, 66.36 (66.34); H, 5.60 (5.57); N, 4.82 (4.84).

[0138] Example 4: Homopolymerization of Ethylene

[0139] The polymerization reaction was carried out in a 250 mL stainless - steel autoclave. The autoclave equipped with mechanical stirring was heated to 120 °C, evacuated for 1 h, adjusted to the required temperature conditions for polymerization, filled with ethylene gas at 0.1 MPa, and a 60 mL toluene solution containing an appropriate amount of Al i Bu3 which had been dried and purified was added. After maintaining the temperature for a period until it was constant, ethylene gas at 0.5 MPa was introduced, and then the main catalyst and Ph3CB(C6F5)4 were added, followed by stirring for a period of time. After the polymerization reaction was completed, the residual ethylene gas was released. The autoclave was opened, and the obtained polymerization reaction mixture was poured into a mixed solution of 3 M hydrochloric acid and ethanol with a volume ratio of 1:1. After stirring for 5 min, it was filtered and the polyethylene product was dried in a vacuum oven. Its mass was weighed and its molecular weight was measured. The results are shown in Table 1.

[0140] Table 1 Results of Ethylene Homopolymerization Catalyzed by C1 - C24 as Main Catalysts a

[0141]

[0142]

[0143] a Polymerization conditions: The dosage of the main catalyst is 2 μmol; Al i Bu3 / Ph3CB(C6F5)4 / main catalyst = 35.5 / 1.5 / 1; b The unit is 10 6 g (mol M) -1 h -1 ; c M w is measured by GPC at 135 °C using trichlorobenzene as the solvent, and the unit is 10 4 g mol -1 .

[0144] Example 5: Copolymerization reaction of ethylene and α-olefin (1-hexene or 1-octene)

[0145] The polymerization reaction is carried out in a 250 mL stainless steel autoclave. The autoclave equipped with mechanical stirring is heated to 120 °C, evacuated for 1 h, filled with ethylene gas at 0.1 MPa, adjusted to the polymerization temperature condition, and a 60 mL toluene mixed solution containing a certain amount of alkyl aluminum and a certain concentration of α-olefin (1-hexene or 1-octene) is added to the autoclave. After maintaining the temperature for a period of time until the temperature is constant, 0.5 MPa ethylene gas is introduced, and then the main catalyst and Ph3CB(C6F5)4 are added, and stirred for a period of time. After the polymerization reaction is completed, the residual ethylene gas is released, the autoclave is opened, the obtained polymerization reaction mixture is poured into a mixed solution of 3 M hydrochloric acid and ethanol with a volume ratio of 1:1, stirred for 5 min and then filtered, dried in a vacuum oven, weighed, its molecular weight and molecular weight distribution are measured, and the comonomer insertion rate is measured by carbon spectrum. The results are shown in Tables 2 and 3.

[0146] Table 2 Results of copolymerization of ethylene and 1-hexene a

[0147]

[0148]

[0149]

[0150] a Polymerization conditions: The polymerization temperature is 150 °C; the polymerization time is 3 min; the dosage of the main catalyst C1 - C24 is 1 μmol, and the cocatalyst is Al i Bu3 / Ph3CB(C6F5)4, Al i Bu3 / Ph3CB(C6F5)4 / main catalyst = 75 / 1.5 / 1; b The unit is 10 7 g (mol M) -1 h -1 ; c M w is measured by GPC at 135 °C using trichlorobenzene as the solvent, and the unit is 104 g mol -1 ; d was measured by 13 13C NMR, referring to J.Macromol.Sci.Rev.Macromo.Chem.Phys., 1989, C29(2&3): 201-317.

[0151] Table 3 Results of copolymerization of ethylene and 1-octene a

[0152] Serial number Main catalyst Output / g <![CDATA b active]]> <![CDATA c M w > <![CDATA d Insertion rate (mol%)]]> 1 C1 0.73 1.46 12.6 17.5 2 C2 1.35 2.70 13.1 14.3 3 C3 1.96 3.92 17.0 23.9 4 C4 2.16 4.32 21.1 30.1 5 C5 2.18 4.36 23.9 13.6 6 C6 0.97 1.94 26.8 17.3 7 C7 0.91 1.82 29.2 20.4 8 C8 1.42 2.84 15.0 8.9 9 C9 2.00 4.00 21.3 12.2 10 C10 2.23 4.46 21.3 15.0 11 C11 0.86 1.72 25.1 6.7 12 C12 0.89 1.78 24.6 9.5 13 C13 2.17 4.34 24.7 11.7 14 C14 1.93 3.86 19.4 13.3 15 C15 1.05 2.1 27.7 15.8 16 C16 1.16 2.32 28.5 18.6 17 C17 1.25 2.5 30.1 10.2 18 C18 1.07 2.14 25.3 12.5 19 C19 1.71 3.42 15.6 15.9 20 C20 0.77 1.54 26.4 14.1 21 C21 1.38 2.76 14.8 17.6 22 C22 0.79 1.58 26.1 19.9 23 C23 1.74 3.48 16.0 9.2 24 C24 1.38 2.76 14.6 13.5

[0153] a Polymerization conditions: polymerization temperature was 150 °C; polymerization time was 3 min; 1-octene concentration was 1.5 mol / L; the dosage of the main catalyst C1-C24 was 1 μmol, and the cocatalyst was Al i Bu3 / Ph3CB(C6F5)4, Al i Bu3 / Ph3CB(C6F5)4 / main catalyst = 75 / 1.5 / 1; b The unit is 10 7 g(mol M) -1 h -1 ; c M w was measured by GPC in trichlorobenzene at 135 °C, and the unit is 10 4 gmol -1 ; d was measured by 13 13C NMR, referring to J.Macromol.Sci.Rev.Macromo.Chem.Phys., 1989, C29(2&3): 201-317.

[0154] Comparative Example 1

[0155] The polymerization reaction was carried out in a 250 mL stainless steel autoclave. The autoclave equipped with mechanical stirring was heated to 120 °C, evacuated for 1 h, adjusted to 150 °C, filled with 0.1 MPa of ethylene gas. A 60 mL toluene solution containing 75 μmol of alkyl aluminum after drying and purification was added to the autoclave, kept warm until the temperature was constant, 0.5 MPa of ethylene gas was introduced, then 1 μmol of the main catalyst (the structural formula is shown below, prepared by referring to Organometallics 2004, 23, 540-546) and Ph3CB(C6F5)4 were added, and the reaction was stirred for 10 min. After the polymerization reaction was completed, the residual ethylene gas was discharged, the autoclave was opened, the obtained polymerization reaction mixture was poured into a mixed solution of 3M hydrochloric acid and ethanol with a volume ratio of 1:1, stirred for 5 min and then filtered, and the polyethylene product was dried in a vacuum oven, weighed, and its molecular weight was measured. The polymer yield was 0.17 g, and the molecular weight Mw was 1.1×10 4 g / mol.

[0156] From the comparison of the data in this comparative example with the data in Entry 1 of Table 1, it can be seen that the main catalyst in the present invention can catalyze ethylene polymerization under the same conditions to obtain a polymer with a significantly higher molecular weight at a higher activity than in Comparative Example 1.

[0157]

[0158] Comparative Example 2

[0159] The polymerization reaction was carried out in a 250 mL stainless steel autoclave. The autoclave equipped with mechanical stirring was heated to 120 °C, evacuated for 1 h, filled with ethylene gas at 0.1 MPa, the system was adjusted to 150 °C, and a 60 mL toluene mixed solution of 75 μmol of alkylaluminum and 1 - hexene at 1 mol / L (the concentration of hexene in the solution was 1 mol / L) was added to the autoclave. After maintaining the temperature until it was constant, ethylene gas at 0.5 MPa was introduced, and then the main catalyst (the same as in Comparative Example 1) and Ph3CB(C6F5)4 were added, and the mixture was stirred for 3 min. After the polymerization reaction was completed, the residual ethylene gas was released, the autoclave was opened, the obtained polymerization reaction mixture was poured into a mixed solution of 3M hydrochloric acid and ethanol with a volume ratio of 1:1, stirred for 5 min and then filtered, and dried in a vacuum oven. Its mass was weighed and its molecular weight was measured. The polymer yield was 0.08 g, and the molecular weight Mw was 0.7×10 4 g / mol.

[0160] From the comparison of the data in this comparative example with the data in Entry 2 of Table 2, it can be seen that under the same polymerization conditions, relative to Comparative Example 2, the catalyst in the present invention, even though it has the same substituents as the main catalyst in the comparative example, has higher activity based on its specifically modified structure, and the obtained polymer has a significantly higher molecular weight.

Claims

1. A ligand precursor compound having the structural formula shown in Formula I below: In Formula I, Cp' is a substituted or unsubstituted cyclopentadienyl group, a substituted or unsubstituted indenyl group, or a substituted or unsubstituted benzoindenyl group, wherein In the case of being substituted, the substituent is selected from the group consisting of: C1-C30 alkyl, C1-C30 alkyl substituted by amino, 5-6 membered heterocyclic group containing N heteroatom, C6-C30 aryl, C7-C30 aralkyl, which may be optionally further substituted by halogen or C1-C30 alkyl; Y is CR 5 or N, R 5 is selected from H, C1-C30 alkyl, C6-C30 aryl, C7-C30 aralkyl; R 1 , R 2 Each is independently selected from C1-C30 alkyl, C3-C30 cycloalkyl, substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C7-C30 aralkyl, substituted or unsubstituted C5-C30 monocyclic or condensed heteroaryl containing N heteroatom, wherein the substitution means that the substitution may be by C1-C30 alkyl, C3-C30 cycloalkyl, C6-C30 aryl, C7-C30 aralkyl, C2-C30 dialkylamino or C3-C30 silyl; R 3 and R 4 Each is independently H, C1-C30 alkyl, C6-C30 aryl, C7-C30 aralkyl, or R 3 , R 4 The carbon atoms to which they are attached are linked together to form a ring structure.

2. The ligand precursor compound according to claim 1, wherein The ligand precursor compound of formula I is represented by the following formula I-1: In the above formula I-1, R 6 -R 9 Each is independently H, C1-C30 alkyl, C6-C30 aryl, C7-C30 aralkyl, and the remaining substituents are as defined in claim 1, Specifically, the ligand precursor compound of formula I-1 is further represented by the following formula I-1-1 or I-1-2: 。 3. The ligand precursor compound according to claim 1, wherein The ligand precursor compound of formula I is represented by the following formula I-2: In the above formula I-2, R 3 and R 4 Each is independently H, C1-C30 alkyl, C6-C30 aryl, C7-C30 aralkyl, and the remaining substituents are as defined in claim 1, Specifically, the ligand precursor compound of formula I-2 is further represented by the following formula I-2-1 or I-2-2: 。 4. The ligand precursor compound according to any one of claims 1 to 3, wherein Cp' is selected from cyclopentadienyl, monomethylcyclopentadienyl, dimethylcyclopentadienyl, trimethylcyclopentadienyl, tetramethylcyclopentadienyl, methylethylcyclopentadienyl, methylpropylcyclopentadienyl, methylbutylcyclopentadienyl, dimethyldiphenylcyclopentadienyl, diphenylcyclopentadienyl, indenyl, monomethylindenyl, dimethylindenyl, benzoindenyl, 2-methylbenzoindenyl, 3-dimethylaminoindenyl, 3-diethylaminoindenyl, 3-tetrahydropyrrolylindenyl, 3-piperidinylindenyl, 2-methyl-4-phenylindenyl, 2-benzylindenyl, 2-p-methylbenzylindenyl, 2-p-fluorobenzylindenyl; R 1 , R 2 Each is independently selected from ethyl, n-propyl, isopropyl, n-butyl, 2-butyl, isobutyl, tert-butyl, n-pentyl, 2-pentyl, 3-pentyl, isopentyl, tert-pentyl, n-hexyl, 2-hexyl, 3-hexyl, isohexyl, tert-hexyl, n-heptyl, 2-heptyl, 3-heptyl, 4-heptyl, isoheptyl, tert-heptyl, n-octyl and various isomeric octyl, n-nonyl and various isomeric nonyl, n-decyl and various isomeric decyl, adamantyl (Ad), phenyl, naphthyl, anthracenyl, phenyl substituted with halogen or C1-C6 alkyl or phenyl, naphthyl substituted with halogen or C1-C6 alkyl or phenyl, anthracenyl substituted with halogen or C1-C6 alkyl or phenyl, C1-C6 alkyl substituted with phenyl or tolyl, carbazolyl, carbazolyl substituted with C1-C6 alkyl; R 3 and R 4 Each is independently H, C1-C30 alkyl, C6-C30 aryl, C7-C30 aralkyl; R 5 -R 9 is H, C1-C30 alkyl, C6-C30 aryl, C7-C30 aralkyl, Preferably, Cp' is selected from tetramethylcyclopentadienyl, indenyl, indenyl substituted with methyl or phenyl; R 1 Selected from tert-butyl, Among them, R 10 -R 12 Each is independently selected from C1-C5 alkyl, C6-C20 aryl, C7-C20 alkylaryl, R 13 and R 14 Each independently selected from H or C1-C6 alkyl; R 2 is tert-butyl; R 3 and R 4 Each is independently H, C1-C30 alkyl, C6-C30 aryl, C7-C30 aralkyl; R 5 -R 9 It is H, C1-C30 alkyl, C6-C30 aryl, C7-C30 aralkyl.

5. The ligand precursor compound according to claim 1, wherein The ligand precursor compound is selected from the following:

6. A metal complex formed by the ligand precursor compound according to any one of claims 1 to 5, which is represented by the following formula II: In formula II, M is titanium, zirconium or hafnium; X is independently selected from halogen, C1-C30 alkyl, C1-C30 alkoxy, dialkylamino, C6-C20 aryl, C7-C30 aralkyl; The definitions of other substituents are as defined in claim 1, Specifically, the metal complex of formula II is represented by the following formula II-1 or II-2: More specifically, the metal complex of formula II-1 is further represented by the following formula II-1-1 or II-1-2: The metal complex of formula II-2 is further represented by the following formula II-2-1 or II-2-2: in, In the above general formulas representing metal complexes, except for R in formula II-2, II-2-1, and II-2-2 3 and R 4 Each of the substituents is independently H, C1-C30 alkyl, C6-C30 aryl, or C7-C30 aralkyl, and the remaining substituents are as defined in claim 1.

7. The metal complex according to claim 6, wherein The metal complex is selected from the following: 。 8. The method for preparing the metal complex according to claim 6, comprising the following steps: In the above reaction scheme, X' represents halogen, and the definitions of other substituents are as defined in claim 6, 1) reacting a compound of formula 1 with a compound of formula 2 in the presence of a base to obtain an intermediate product 3; 2) Under an inert atmosphere, the intermediate product 3 is sequentially reacted with n-butyl lithium, (substituted) cyclopentenone or (substituted) indanone, and then dehydrated under acidic conditions to obtain a ligand precursor compound 4; 3) under anhydrous and oxygen-free conditions, adding alkyl lithium to the ligand precursor compound of formula 4 to generate a dilithium salt of the ligand precursor compound, and then adding a metal precursor compound MX4 in which X is a halogen to react and generate a metal complex in which X is a halogen, or, Adding alkyl lithium or Grignard reagent RM' to the aforementioned metal complex where X is a halogen to obtain a corresponding dialkyl, aryl or aralkyl substituted metal complex, or, Under anhydrous and oxygen-free conditions, in a toluene solvent, the ligand precursor compound shown in formula 4 directly reacts with the metal precursor compound MX4 in which X is an alkyl group, an aralkyl group, or a dimethylamine group to generate a metal complex. The metal precursor compound is a metal-based compound, a metal halide, a metal alkoxide, a metal dibenzyl dihalide or a metal bis(trimethylsilylmethyl) dihalide, and the metal in the metal precursor compound is selected from titanium, zirconium or hafnium.

9. Use of the metal complex as claimed in claim 6 in catalyzing olefin polymerization.

10. A catalyst composition comprising: i. The metal complex as claimed in claim 6 as a main catalyst, and ii. a co-catalyst selected from alkylaluminoxane or modified alkylaluminoxane or alkylaluminum / organoboron compound composite system or alkylaluminum chloride / organoboron compound composite system, Preferably, The alkylaluminoxane includes methylaluminoxane (MAO), The modified alkylaluminoxane includes modified methylaluminoxane (MMAO), The alkyl aluminum includes trimethyl aluminum, triethyl aluminum, triisobutyl aluminum, The alkylaluminum chloride includes diethylaluminum chloride and sesquiethylaluminum chloride. The organic boron compounds include Ph3CB(C6F5)4, B(C6F5)3, Me3OB(C6F5)4, Ph3CB[C6H3(CF3)2]4, B[C6H3(CF3)2]3, Me3OB[C6H3(CF3)2]4, and PhR a 2HNB(C6F5)4 and PhR a 2HNB[C6H3(CF3)2]4, where R a is a C1-C18 alkyl group, Preferably, when the co-catalyst is methylaluminoxane (MAO), the molar ratio of aluminum in the co-catalyst to the metal in the main catalyst is 5-10000:1, preferably 100-2000:1; more preferably 1000-1500:1, When the co-catalyst is an alkyl aluminum / organoboron compound composite system or an alkyl aluminum chloride / organoboron compound composite system, the molar ratio of aluminum in the co-catalyst to the metal in the main catalyst is 5-10000:1, preferably 50-150:1, more preferably 50-75:

1. Preferably, the molar ratio of boron in the co-catalyst to the metal in the main catalyst is 1-2:

1.

11. A method for polymerizing ethylene, comprising catalyzing olefin polymerization in the presence of the catalyst composition as claimed in claim 10, Optionally, the olefin polymerization is selected from: ethylene homopolymerization, copolymerization of ethylene and α-olefin, copolymerization of propylene and α-olefin, copolymerization of ethylene and cycloolefin, copolymerization of propylene and cycloolefin, or terpolymerization of ethylene, propylene and cycloolefin. Optionally, the α-olefin is 1-propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene or 1-octene, Optionally, the cycloolefin is cyclopentadiene, norbornene, ethylidene norbornene or dicyclopentadiene, Preferably, the polymerization temperature in the polymerization reaction is 0 to 200° C., and the pressure of the ethylene monomer in the polymerization reaction is 0.05 to 5 MPa.

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