A metal complex comprising a naphthalene ring bridge and its use for catalysing the polymerisation of olefins

Abstract

The present application provides a metal complex containing naphthalene ring bridging, which has a structure as shown in formula (I). The present application also provides a catalyst composition containing the metal complex and an olefin polymerization method, especially a propylene polymerization method. The metal complex containing naphthalene ring bridging provided by the present application can tolerate a higher polymerization temperature, and can ensure high stereoregularity of a polymerization product at a high polymerization temperature, and has very high catalytic activity, and can efficiently catalyze homopolymerization or copolymerization of various olefin substrates, and the polymerization product prepared has the characteristics of adjustable molecular weight, narrow molecular weight distribution, adjustable copolymer monomer ratio, etc.

Description

Technical Field

[0001] This invention relates to the field of olefin catalytic polymerization technology, specifically to a metal complex containing a naphthalene ring bridge and its uses, and also to a catalyst composition containing the metal complex and a method for olefin polymerization, particularly a method for propylene polymerization. Background Technology

[0002] Since the 1950s, the discovery of ferrocene (FeCp2), the elucidation of π-bond sandwich structures, and the discovery and use of Ziegler-Natta catalysts have made it possible to prepare polymers from ethylene monomers under mild conditions, and the application of polyolefin materials has gradually become widespread. Nevertheless, with the rise and development of characterization techniques such as NMR and single-crystal diffraction, in-depth research on the coordination polymerization mechanism of olefins has only been a matter of the past two or three decades.

[0003] Correspondingly, adjusting the catalyst structure to control the molecular weight, molecular weight distribution, and primary structure (chain structure) of the polymer products is a widely studied and researched topic. Among these, metallocene catalysts and post-metallocene catalysts play a crucial role in the preparation of polyolefin materials due to their single active center, high polymerization activity, and narrow distribution of polymer products. Ewen et al. (J.Am.Chem.Soc.1987,109,6544-6545.) used a chiral bridged bismetallocene catalyst to prepare polypropylene with a narrow distribution and moderate stereoregularity. Furthermore, atactic polypropylene can be prepared using non-bridged bismetallocene catalysts (J.Am.Chem.Soc.1984,106,6355-6364.).

[0004] Although polypropylene with stereoregularity far exceeding that of amorphous polypropylene, but not highly stereoregular, can be prepared through steric hindrance and electronic effects of substituent groups, the preparation of highly isotropic polypropylene still presents significant challenges in terms of catalyst requirements. On the other hand, for the preparation of copolymers of propylene with ethylene or other α-olefins, especially polypropylene containing stereoregularity in the propylene sequence, excellent catalytic properties should include: high catalytic efficiency of the comonomer, high-temperature thermal stability, controllable stereoselectivity, homogeneous polymer composition, and high molecular weight.

[0005] In this regard, the advantages of post-metallocene catalysts over metallocene catalysts are obvious. First, the synthesis of the catalyst is simpler. On the other hand, since they are not limited by the substitution structure of the cyclic rings, the structures of post-metallocene catalysts are also more diverse.

[0006] Chinese patent CN 101490096B discloses a zirconium tetraoxane-type metal catalyst, which, by changing the carbon number and steric hindrance of the bridging aliphatic groups between the two oxygen atoms, as well as the steric hindrance and electronic effects of the substituents on the adjacent aryl groups, catalyzes the copolymerization of ethylene and propylene to prepare high molecular weight (22.9 × 10⁻⁶) catalysts under reaction conditions of ≥100℃ and 3.7 MPa. 4 g / mol ~ 24.3 × 10 4 The copolymer contains g / mol of propylene monomers. At the same time, while ensuring a high conversion rate of ethylene monomers, the conversion rate of propylene monomers is also generally high, ranging from 62.5% to 80.1%.

[0007] Chinese patent CN 116323694A discloses a bi(heterocyclic-alkoxide) Lewis base catalyst, which exhibits high stability and high activity under high-temperature polymerization conditions. Furthermore, the molecular weight of the polymerization product is adjustable (ultra-high molecular weight or low molecular weight). In addition, this type of catalyst can achieve isotactic polymerization of propylene. The structural characteristic of this catalyst is that the group attached to one of the coordinating oxygen atoms is a heteroaromatic ring, which enhances the electron-donating ability of the ligand skeleton structure and inhibits chain transfer reactions.

[0008] Chinese patent CN 116194491A discloses a catalytic system containing a diphenylphenoxy metal-ligand complex, which employs a solution polymerization method and can simultaneously maintain catalyst efficiency, reactivity, and the ability to generate polymers with good physical properties.

[0009] Other referenced patent documents include: CN 101484475B, US 6841502B2, US 6525157B2 and CN105121558A, etc.

[0010] For the diverse range of propylene-based olefin polymers, most applications require elastomer materials with high melting points, i.e., high isotactic regularity of the polypropylene segments. However, in the preparation of propylene-based elastomers, increasing the polymerization temperature is generally detrimental to isotactic regularity; therefore, the polymerization temperature is typically controlled below 120°C. On the other hand, due to the viscoelasticity of propylene-based elastomers, the mainstream production process is solution polymerization. Considering the removal of polymerization heat during production, as well as post-processing devolatilization and solvent recycling, increasing the polymerization temperature can reduce production costs and improve production efficiency.

[0011] In summary, there is currently a high demand for propylene-based polymers that can be prepared at high polymerization temperatures (preferably solution polymerization) with tunable molecular weight, high stereoregularity, and narrow molecular weight distribution. Summary of the Invention

[0012] The inventors obtained a metal complex that is very suitable as an olefin polymerization catalyst by introducing a rigid naphthalene ring as a bridging group into a tetradentate metal complex. It has high catalytic activity and can ensure the chain structure characteristics of the polymer while increasing the polymerization temperature (≥120℃), thereby improving polymerization efficiency and reducing production costs. Based on this, the present invention was derived.

[0013] Therefore, one object of the present invention is to provide a metal complex comprising a naphthalene ring bridge and its use therein.

[0014] Another object of the present invention is to provide a catalyst composition comprising the metal complex and its use therein.

[0015] Another object of the present invention is to provide a method for olefin polymerization, particularly a method for propylene polymerization.

[0016] A first aspect of the present invention provides a metal complex comprising a naphthalene ring bridge having a structure as shown in formula (I):

[0017]

[0018] In formula (I), R1, R2, R3 and R4 each independently represent H, halogen, C1-C10 alkyl, C1-C10 alkoxy, C1-C10 haloalkyl, C1-C10 haloalkoxy, C3-C10 cycloalkyl or C6-C20 aryl; or any two groups of R1, R2, R3 and R4 are connected and fused with a naphthalene ring to form a substituted or unsubstituted C12-C20 aryl group. When a substituted group is represented, the substituent is selected from halogen, C1-C6 alkyl, C1-C6 alkoxy, C3-C10 cycloalkyl or C6-C12 aryl.

[0019] R5 may be the same or different, R6 may be the same or different, and R5 and R6 may each independently represent halogen, C1-C10 alkyl, C1-C10 alkoxy, C1-C10 haloalkyl, C1-C10 haloalkoxy, C3-C10 cycloalkyl, C6-C20 aryl or 5-20 heteroaryl.

[0020] M represents titanium (Ti), zirconium (Zr), or hafnium (Hf);

[0021] X may be the same or different, representing halogen, NR7R8, C1-C10 alkyl, C1-C10 alkoxy or C6-C20 aryl; R7 and R8 each independently represent H or C1-C10 alkyl.

[0022] In some preferred embodiments, in formula (I), R1, R2, R3 and R4 each independently represent H, halogen, C1-C6 alkyl, C1-C6 alkoxy, C1-C6 haloalkyl, C1-C6 haloalkoxy, C3-C8 cycloalkyl or C6-C12 aryl; or any two groups of R1, R2, R3 and R4 are connected and fused with a naphthalene ring to form a substituted or unsubstituted C12-C16 aryl group, wherein when a substituted group is represented, the substituent is selected from halogen or C1-C6 alkyl;

[0023] R5 and R6 each independently represent a C1-C6 alkyl group or a 10-18 membered heteroaryl group;

[0024] M represents Zr or Hf;

[0025] X represents F, Cl, Br, or an amino group (-NH2).

[0026] In some preferred embodiments, in formula (I), R1, R2, R3 and R4 each independently represent H, C1-C4 alkyl, C1-C4 alkoxy, C1-C4 haloalkyl, C1-C4 haloalkoxy or C6-C12 aryl; or in one or two groups of R1 and R2, R2 and R3, R3 and R4, two groups are linked together and fused with a naphthalene ring to form a substituted or unsubstituted C12-C16 aryl group, and when a substituted group is represented, the substituent is selected from halogen or C1-C4 alkyl;

[0027] R5 and R6 each independently represent a C1-C4 alkyl group or a 10-15 membered heteroaryl group;

[0028] M represents Zr or Hf;

[0029] X represents Cl or Br.

[0030] In some further preferred embodiments, R1, R2, R3 and R4 each independently represent H, methyl, ethyl, n-propyl, isopropyl, n-butyl, 2-methylbutyl, isobutyl, tert-butyl, methoxy, ethoxy, trifluoromethoxy, methyl or phenyl substituted with 1 to 3 chlorine or bromine atoms;

[0031] Alternatively, any two groups of R1, R2, R3, and R4 may be linked together to form one of the following structures:

[0032]

[0033] R5 and R6 each independently represent methyl, ethyl, n-propyl, isopropyl, n-butyl, 2-methylbutyl, isobutyl, tert-butyl, or carbazole.

[0034] In some preferred embodiments, the metal complex is selected from:

[0035]

[0036]

[0037]

[0038] Wherein, M represents Zr or Hf. When M represents Zr, the metal complexes are numbered C1-Zr to C20-Zr, and when M represents Hf, the metal complexes are numbered C1-Hf to C20-Hf.

[0039] A second aspect of the present invention provides a ligand compound comprising a naphthalene ring bridge having a structure as shown in formula (II):

[0040]

[0041] In equation (II), R1 to R6 are each defined independently as in any of the above technical solutions.

[0042] A third aspect of the present invention provides a catalyst composition comprising a main catalyst and a co-catalyst, wherein the main catalyst is a metal complex containing a naphthalene ring bridge as described in any of the above-described technical solutions.

[0043] In the catalyst composition provided by this invention, the co-catalyst can be any type commonly found in the art, such as aluminum oxanes, alkyl aluminum oxanes, alkyl aluminum chlorides, etc. In some preferred embodiments, the co-catalyst is one or two of alkyl aluminum oxanes and modified alkyl aluminum oxanes, such as one or two of methyl aluminum oxane (MAO) and modified methyl aluminum oxane (MMAO).

[0044] In the catalyst composition provided by the present invention, the molar ratio of metal Al in the co-catalyst to the central metal M of the metal complex containing naphthalene ring bridging can be adjusted according to different application scenarios (e.g., different types of polyolefins). Generally, it can be 10 to 30,000:1, and more specifically, it can be 100 to 20,000:1. For example, it can be 100:1, 500:1, 1000:1, 2000:1, 3000:1, 4000:1, 5000:1, 6000:1, 7000:1, 8000:1, 9000:1, 10000:1, 11000:1, 12000:1, 13000:1, 14000:1, 15000:1, 16000:1, 17000:1, 18000:1, 19000:1, 20000:1, or any molar ratio range.

[0045] The catalyst composition provided by this invention may further include other auxiliaries or additives commonly found in the art. In some preferred embodiments, the catalyst composition may also include a borate activator, such as one or both of N,N-dimethylaniline-onium tetra(perfluorophenyl)borate and triphenylcarbazium tetra(perfluorophenyl)borate.

[0046] A fourth aspect of the present invention provides the use of the metal complex containing naphthalene ring bridging as described in any of the above-described technical solutions, or the catalyst composition as described in any of the above-described technical solutions, in the catalytic polymerization of olefins.

[0047] In some preferred embodiments, the olefin may be a straight-chain or branched olefin of C2 to C20.

[0048] In some preferred embodiments, the olefin polymerization can be propylene polymerization, for example, homopolymerization of propylene, or copolymerization of propylene with ethylene or C4-C20 α-olefins. In some more preferred embodiments, the α-olefin can be 1-hexene or 1-octene.

[0049] The fifth aspect of the present invention provides an olefin polymerization method, which uses a metal complex containing a naphthalene ring bridge as described in any of the above technical solutions, or a catalyst composition as described in the above technical solutions, as a catalyst, under the catalytic action of the catalyst, the olefin monomer undergoes a polymerization reaction.

[0050] In some preferred embodiments, the olefin may be a straight-chain or branched olefin of C2 to C20.

[0051] In some preferred embodiments, the olefin polymerization can be propylene polymerization, for example, homopolymerization of propylene, or copolymerization of propylene with ethylene or C4-C20 α-olefins. In some more preferred embodiments, the α-olefin can be 1-hexene or 1-octene.

[0052] The olefin polymerization method provided by this invention can be a solution polymerization method commonly used in the art. In some preferred embodiments, the olefin polymerization can be carried out in an organic solvent. In some more preferred embodiments, the organic solvent can be one or more of ethers, aromatic hydrocarbons, alkanes, nitriles, and halogenated hydrocarbons, such as C8 isoalkane solvents Isopar E, isohexanes, toluene, etc.

[0053] In the olefin polymerization method provided by this invention, the reaction temperature of the polymerization reaction can be increased to ≥100℃, for example, to ≥120℃. In some preferred embodiments, the reaction temperature of the polymerization reaction can be 120~160℃, for example, 140℃.

[0054] In the olefin polymerization method provided by the present invention, other process conditions can be common process conditions in the art, or can be appropriately adjusted by those skilled in the art according to the actual reaction conditions such as the type of comonomer and the performance requirements of the polymerization product.

[0055] The olefin polymerization method provided by this invention may further include the following processes:

[0056] (1) Add organic solvents, co-catalysts, monomers and other optional auxiliaries or additives to the polymerization reaction vessel;

[0057] (2) When the temperature and pressure of the polymerization system reach the set value, add the main catalyst to initiate the polymerization reaction (e.g., polymerization reaction for 5 to 60 minutes), and quench the reaction after the reaction is completed (e.g., add the reaction solution to an appropriate amount of ethanol to quench the reaction).

[0058] (3) The polymer product obtained by sedimentation is repeatedly washed (e.g., using ethanol) and dried to constant weight to obtain the target polyolefin product.

[0059] In the olefin polymerization method provided by the present invention, when propylene is copolymerized with ethylene or other α-olefins, the methyl branching in the resulting polymer can be 0.5 to 950 per 1000 carbon atoms, the long chain (carbon number ≥ 2) branching ratio can be 1.0 to 40.0%, the melting temperature range of the polymer product can be 50 to 160°C, and the glass transition temperature range can be -40 to 10°C.

[0060] The technical solution provided by this invention has the following advantages:

[0061] (1) The metal complex containing naphthalene ring bridging provided by the present invention contains a rigid naphthalene ring as a bridging group, which can significantly enhance the rigidity of the metal complex, thus enabling it to withstand higher polymerization temperatures and ensure the high stereoregularity of the polymerization product at high polymerization temperatures. Therefore, it is a catalyst with great application potential for olefin polymerization.

[0062] (2) The metal complex containing naphthalene ring bridged by the present invention has high catalytic activity and can efficiently catalyze the homopolymerization or copolymerization of a variety of olefin substrates, especially the homopolymerization of propylene and the copolymerization of propylene with ethylene or α-olefins. It has a wider substrate applicability and a wider range of applications. The polymer products obtained have the characteristics of adjustable molecular weight, narrow molecular weight distribution and adjustable comonomer ratio.

[0063] (3) The method for preparing metal complexes containing naphthalene ring bridging provided by the present invention is simple, easy to operate and easy to control, and does not require high costs, thus having strong industrial applicability. Detailed Implementation

[0064] The following describes specific embodiments of the catalyst system of the present invention. It should be clearly understood first that the catalyst system disclosed in this invention has different forms and should not be construed or interpreted as being limited to the specific embodiments described herein. Furthermore, the purpose of providing embodiments is to make the disclosure of this invention more thorough and complete, and to fully convey the intent and scope of the subject matter to those skilled in the art. Therefore, any other supplementary embodiments without inventive step should fall within the protection scope of this invention.

[0065] The following are some common abbreviations: Me: methyl; Et: ethyl; Ph: phenyl; i-Pr: isopropyl; t-Bu: tert-butyl; Carba: carbazole (9-azafluorene); MAO: methylaluminoxane; MMAO: modified methylaluminoxane.

[0066] Unless otherwise defined, the terminology used in this invention should be considered to have the ordinary meaning that can be understood by those skilled in the art. Some common terms are introduced and explained below:

[0067] The singular forms used in this article, such as “a,” “an,” “the,” “the,” “the above,” etc., contain both singular and plural referents.

[0068] The use of "include" or "include" in this article is open-ended rather than restrictive, meaning that it does not exclude unlisted types, elements, or methods or steps.

[0069] As used herein, "one embodiment" specifically refers to the particular feature, structure, or property of the described subject when the phrase appears. Therefore, "one embodiment" appearing in different places herein does not necessarily refer to the same embodiment. On the other hand, some specific embodiments may include some features of other embodiments but not all features of other embodiments. In such cases, combinations of embodiments with different features, although not listed herein, should be assumed to be included in the claims and statements herein.

[0070] As used herein, "C1-Cn" includes C1-C2, C1-C3, ..., C1-Cn. For example, the "C1-C10" group refers to a portion having 1 to 10 carbon atoms, i.e., the group contains 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 carbon atoms. Therefore, for example, "C1-C4 alkyl" refers to an alkyl group containing 1 to 4 carbon atoms, i.e., the alkyl group is selected from methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, sec-butyl, and tert-butyl. Numerical ranges, such as "1-6", refer to integers within a given range.

[0071] The term "alkyl" as used alone or in combination in this article refers to molecules with a molecular formula conforming to C10000. n H 2n+1 The alkyl group of the general formula, wherein n is an integer greater than or equal to 1. The alkyl group can be linear or branched. The alkyl group of the present invention contains 1 to 10 carbon atoms, preferably 1 to 8 carbon atoms, and more preferably 1 to 6 carbon atoms. Non-limiting examples of alkyl groups include methyl, ethyl, n-propyl, isopropyl, 2-methyl-1-propyl, 2-methyl-2-propyl, 2-methyl-1-butyl, 3-methyl-1-butyl, 2-methyl-3-butyl, 2,2-dimethyl-1-propyl, 2-methyl-1-pentyl, 3-methyl-1-pentyl, 4-methyl-1-pentyl, 2-methyl-2-pentyl, 3-methyl-2-pentyl, 4-methyl-2-pentyl, 2,2-dimethyl-1-butyl, 3,3-dimethyl-1-butyl, 2-ethyl-1-butyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, isopentyl, neopentyl, tert-pentyl, and hexyl, as well as longer alkyl groups such as heptyl and octyl, and their respective isomers.

[0072] The term "alkyl" as used in this article refers to an alkyl group linked to other groups, such as alkyl in alkoxy or alkyl in haloalkyl, and is defined the same as when used alone.

[0073] The term “halogenated” as used alone or in combination herein refers to the substitution of one or more hydrogen atoms (including all hydrogen atoms) in a group by one or more halogens, the definition of which is the same as when used alone.

[0074] The term "alkoxy" as used alone or in combination herein refers to an alkyl ether group, denoted as "alkyl-O-". Non-limiting examples of alkoxy groups include methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, sec-butoxy, tert-butoxy, etc.

[0075] As used alone or in combination herein, the term "cycloalkyl" refers to a non-aromatic saturated carbocyclic ring, which may include a single-carbon ring (having one ring), a double-carbon ring (having two rings), or a multi-carbon ring (having more than two rings), and the rings may be bridged or spirocyclic. A cycloalkyl group may have 3 to 10 cyclic carbon atoms, for example, 3 to 6 cyclic carbon atoms. Non-limiting examples of cycloalkyl groups include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, etc.

[0076] The term "aryl" as used alone or in combination herein refers to an optionally substituted aromatic hydrocarbon group having 6 to 20, such as 6 to 16, 6 to 12, or 6 to 10 cyclic carbon atoms. It can be a monocyclic aryl, bicyclic aryl, or more cyclic aryl groups. A bicyclic aryl or more cyclic aryl group can be a monocyclic aryl group fused with other independent rings, such as alicyclic or aromatic rings. Non-limiting examples of aryl groups include phenyl, biphenyl, naphthyl, 1,2,3,4-tetrahydronaphthyl, indenyl, 5-, 6-, 7-, or 8-tetrahydronaphthyl, anthracene, fluorenyl, azulel, pyrene, etc.

[0077] The term “heteroaryl” as used alone or in combination herein refers to an optionally substituted aromatic hydrocarbon group having 1 to 4 atoms selected from nitrogen, oxygen and / or sulfur in its ring atom, having a total of 5 to 20, such as 5 to 18, 10 to 18 or 10 to 15 cyclic atoms, which can be monocyclic heteroaryl, bicyclic heteroaryl or more cyclic heteroaryl.

[0078] The terms “halogen,” “halogen atom,” or “halogen atom,” used alone or in combination herein, refer to fluorine (F), chlorine (Cl), bromine (Br), or iodine (I). “Metal halide” or “halide” refers to the anionic form of a halogen atom.

[0079] The term "α-olefin" as used alone or in combination herein refers to a monoolefin with a double bond at the end of the molecular chain, and its molecular formula may be represented as R-CH=CH2, where R represents "C2-C10 alkyl". The α-olefin has, but is not limited to, 4 to 20 carbon atoms; for example, it may have 4 to 12 carbon atoms, 4 to 10 carbon atoms, or 4 to 8 carbon atoms. The double bond in these groups may be in either a cis or trans conformation and should be understood to include both isomers. The olefin as defined herein may be a single type of olefin or a mixture of multiple olefins.

[0080] The term "methylaluminoxane" used alone or in combination herein is sometimes also referred to in the art as "aluminoxane" or "MAO". It has the molecular formula -Al(R)-O- and is soluble in toluene. It exists in solvents mainly in the form of free state, linear oligomers, and cage-like oligomers. It acts as an activator for transition metal complexes. On the one hand, "methylaluminoxane" can attack the transition metal center to form metal alkylates. At the same time, excess methylaluminoxane can also remove impurities in the reaction system.

[0081] The term “modified methylaluminoxane” as used alone or in combination herein is sometimes referred to in the art as “MMAO”, which refers to a mixture of methylaluminoxane and trialkylaluminum, and has the same effect as methylaluminoxane.

[0082] The technical solution of the present invention will be further described in detail below with reference to specific embodiments.

[0083] Unless otherwise specified, all raw materials or reagents used in the embodiments of this invention are commercially available products, such as those purchased from companies like Xinweier, Inokai, and Sinopharm. Some solvents (e.g., Isopar E) and polymerization monomers (e.g., 1-hexene monomer) are treated as follows: high-purity nitrogen (≥99.0%) is inserted into the bottom of the solvent storage bottle via a pipeline, and the mixture is bubbled at 1 bar for 2 hours. Afterward, an appropriate amount of treated molecular sieve is added and the mixture is soaked for at least 48 hours.

[0084] Unless otherwise specified, all percentages used in the embodiments of the present invention are mass percentages.

[0085] In embodiments of the present invention, the polymer performance testing method is as follows:

[0086] (1) The weight-average molecular weight and molecular weight distribution of olefin polymers were determined by gel permeation chromatography-infrared spectroscopy (GPC-IR).

[0087] (2) The content and stereoregularity of ethylene monomer and 1-hexene monomer in olefin polymer were determined by nuclear magnetic resonance spectrometry. The specific peak assignments and calculations are referenced in the literature (Macromolecules, 1999, 32, 1620-1625).

[0088] Example 1

[0089] The synthetic routes for catalysts C1-Zr, C2-Zr, C3-Zr, C5-Zr-C15-Zr, C18-Zr, C19-Zr, and C20-Zr are as follows:

[0090]

[0091] Step 1: Synthesis of compound 2 (2-bromo-4,6-dimethylphenol)

[0092] Br2 (50 mmol) was dissolved in 30 mL of dichloromethane to prepare a solution, and 2,4-dimethylphenol (50 mmol) was dissolved in 150 mL of dichloromethane solution. The solutions were transferred to a 500 mL round-bottom flask, stirred magnetically, and the Br2 solution was added dropwise to the 2,4-dimethylphenol solution in dichloromethane under a 0°C cold bath. Simultaneously, nitrogen gas was bubbled through the reaction mixture to remove the generated HBr. After the addition was complete, the cold bath was removed. The bottom flask was slowly heated to room temperature and the reaction was allowed to proceed for 2 hours. After the reaction was complete, 100 ml of deionized water was added to quench the reaction. The mixed solution was transferred to a separatory funnel to separate the dichloromethane organic phase. The aqueous phase was extracted three times with 50 ml of dichloromethane. All organic phases were collected, dried with Mg2SO4, and filtered. The dichloromethane solvent was removed by rotary evaporation. The fraction collected at 50-60 °C was then fractionally distilled to obtain a colorless oily substance, which was compound 2 (40 mmol, yield 80.0%).

[0093] The second step is the synthesis of compound 3.

[0094] Compound 2 (54.3 mmol) was dissolved in 150 mL of dichloromethane and transferred to a 250 mL round-bottom flask. BnBr (54.3 mmol) and K2CO3 (60 mmol) were added simultaneously. The mixture was stirred with a magnetic stirrer and refluxed at 60 °C for 12 h. After the reaction was completed, the mixture was cooled to room temperature, the precipitate was filtered, dried with Mg2SO4, and filtered again. The dichloromethane solvent was removed by rotary evaporation to obtain compound 3 (40 mmol, yield 82.9%).

[0095] The third step is the synthesis of compound 5 (1,8-bis(2-bromophenol)naphthalene).

[0096] Using compound 4 (1,8-dibromonaphthalene) and 2-bromophenol as starting materials, compound 5 (32.7 mmol, yield 74.1%) was obtained by following the synthetic procedure in step 2.

[0097] Step 4: Synthesis of Compound 6

[0098] Compound 5 (55.8 mmol) was added to a 1000 mL three-necked round-bottom flask under a nitrogen atmosphere. Simultaneously, 400 mL of purified tetrahydrofuran was transferred to the three-necked flask via a tubing. The three-necked flask was placed in a dry ice / acetone cold bath at -78 °C. 2.5 M n-butyllithium (25.6 mL, 58.9 mmol) was slowly added dropwise to the three-necked flask through a funnel over 30 minutes. After the addition was complete, stirring was continued for another 30 minutes. Then, triisopropionate (58.9 mmol) was dissolved in 50 mL of tetrahydrofuran and added dropwise to the three-necked flask through a dropping funnel over 30 minutes. After the addition was complete, stirring was continued at -78 °C for 2 hours. The cold bath was removed, and the mixture was slowly brought to room temperature overnight. Once the reaction was complete, 400 mL of... The reaction was quenched with 1M hydrochloric acid aqueous solution. 100 ml of diethyl ether was added to the mixture for extraction and separation. This process was repeated three times. The three diethyl ether extracts were mixed, dried with MgSO4, and filtered. The solvent was removed by rotary evaporation. The mixture was then separated by column chromatography (SiO2 powder as packing material, hexane / ethyl acetate volume ratio = 3:1) to obtain a white solid, which was compound 6 (40.16 mmol, yield 62%).

[0099] Step 5, Synthesis of Compound 7

[0100] In a glove box, at room temperature, compound 6 (4.0 mmol), compound 3 (8.00 mmol), 10 mL of 2 M Na₂CO₃ aqueous solution, and 35 mL of dimethoxyethane were added to a 100 mL Shrek flask. A magnetic stirrer was added, and then Pd(PPh₃)₄ (0.8 mmol) was added to the solution. The solution was heated to 90 °C and refluxed for 68 h. After the reaction was completed, 40 mL of ethyl acetate was added to quench the reaction. The solution was washed three times with deionized water and once with saturated NaCl aqueous solution to separate the organic phase. The organic phase was dried with MgSO₄ and filtered. The organic solvent was removed by rotary evaporation. The solution was separated by column chromatography (SiO₂ powder as packing material, hexane / ethyl acetate volume ratio = 50:1) to obtain a white solid, which was compound 7 (2.5 mmol, yield 63%).

[0101] Step 6, Synthesis of Compound 8

[0102] Compound 7 (3.3 mmol) and 5% Pd / C (2.00 g) were added to a pressure-resistant 304 stainless steel reactor, followed by 12 ml of ethyl acetate and 12 ml of ethanol. Finally, five drops of glacial acetic acid were added using a glass dropper. The reactor was pressurized with 100 psi H2 and heated to 60 °C. The mixture was stirred for 11 h. After the reaction was completed, the mixture was cooled to room temperature and filtered using a diatomaceous earth-filled sand core funnel. The filter residue was thoroughly washed with 100 ml of ethyl acetate and 100 ml of ethanol to recover the product. All organic phases were mixed, dried with MgSO4, and filtered. The organic solvent was removed using a rotary evaporator to obtain a white solid. The white solid was washed with hexane to obtain compound 8 (2.9 mmol, yield 91%).

[0103] Step 7: Synthesis of compound C1-Zr

[0104] In a glove box, weigh ZrCl4 (3.3 mmol), 0.5 g Na2CO3, and 30 ml tetrahydrofuran into a 100 ml round-bottom flask and add magnetic stirring. Simultaneously, weigh compound 8 (3.5 mmol) and dissolve it in 10 ml tetrahydrofuran. At room temperature, add the tetrahydrofuran solution of compound 8 dropwise to the round-bottom flask. After the addition is complete, let the reaction proceed overnight at room temperature. After the reaction is complete, vacuum dry the tetrahydrofuran solvent and add 20 ml toluene to slurry. Filter using a sintered funnel with diatomaceous earth. Add magnetic stirring to vigorously stir the toluene solution and slowly add 80 ml hexane dropwise. After the hexane addition is complete, filter the precipitate using filter paper and wash the obtained solid powder three times with 30 ml hexane. Then, dry the solid powder with the solvent to obtain a white solid, which is Cl-Zr (1.7 mmol, yield 50%).

[0105] C1-Zr: Elemental analysis: Measured (calculated) C, 64.03 (64.00); H, 4.24 (4.26); Cl, ​​9.95 (9.90); O, 8.98 (8.95); Zr, 12.80 (12.83).

[0106] Using similar raw materials, catalysts C2-Zr, C3-Zr, C5-Zr-C15-Zr, C18-Zr, C19-Zr and C20-Zr were prepared according to the above synthesis method.

[0107] C2-Zr: Elemental analysis: Measured (calculated) C, 66.31 (66.28); H, 5.31 (5.34); Cl, ​​8.90 (8.90); O, 8.03 (8.06); Zr, 11.45 (11.50).

[0108] C3-Zr: Elemental analysis: Measured (calculated) C, 68.16 (68.16); H, 6.18 (6.15); Cl, ​​8.05 (8.08); O, 7.26 (7.24); Zr, 10.35 (10.37).

[0109] C5-Zr: Elemental analysis: Measured (calculated) C, 66.31 (66.35); H, 5.31 (5.27); Cl, ​​8.90 (8.88); O, 8.03 (8.05); Zr, 11.45 (11.45).

[0110] C6-Zr: Elemental analysis: Measured (calculated) C, 68.43 (68.40); H, 6.31 (6.34); Cl, ​​7.92 (7.95); O, 7.15 (7.12); Zr, 10.19 (10.19).

[0111] C7-Zr: Elemental analysis: Measured (calculated) C, 68.70 (68.74); H, 6.43 (6.39); Cl, ​​7.80 (7.82); O, 7.04 (7.02); Zr, 10.03 (10.05).

[0112] C8-Zr: Elemental analysis: Measured (calculated) C, 67.51 (67.52); H, 6.32 (6.33); Cl, ​​7.66 (7.64); O, 8.65 (8.64); Zr, 9.86 (9.87).

[0113] C9-Zr: Elemental analysis: Measured (calculated) C, 67.23 (67.20); H, 6.20 (6.23); Cl, ​​7.78 (7.77); O, 8.78 (8.79); Zr, 10.01 (10.00).

[0114] C10-Zr: Elemental analysis: Measured (calculated) C, 62.87 (62.89); H, 5.68 (5.69); Br, 8.18 (8.20); Cl, ​​7.26 (7.28); O, 6.59 (6.57); Zr, 9.40 (9.37).

[0115] C11-Zr: Elemental analysis: Measured (calculated) C, 69.62 (69.65); H, 6.04 (6.06); Cl, ​​7.65 (7.61); O, 6.85 (6.87); Zr, 9.78 (9.80).

[0116] C12-Zr: Elemental analysis: Measured (calculated) C, 69.23 (69.20); H, 6.65 (6.67); Cl, ​​7.60 (7.57); O, 6.86 (6.83); Zr, 9.73 (9.73).

[0117] C13-Zr: Elemental analysis: Measured (calculated) C, 69.40 (69.45); H, 6.75 (6.78); Cl, ​​7.50 (7.45); O, 6.76 (6.73); Zr, 9.63 (9.59).

[0118] C14-Zr: Elemental analysis: Measured (calculated) C, 70.13 (70.10); H, 7.10 (7.13); Cl, ​​7.14 (7.17); O, 6.44 (6.47); Zr, 9.18 (9.21).

[0119] C15-Zr: Elemental analysis: Measured (calculated) C, 72.07 (72.10); H, 6.05 (6.08); Cl, ​​6.86 (6.89); O, 6.19 (6.15); Zr, 8.83 (8.85).

[0120] C18-Zr: Elemental analysis: Measured (calculated) C, 67.33 (67.30); H, 5.19 (5.16); Cl, ​​8.69 (8.64); O, 7.85 (7.80); Zr, 11.14 (11.11).

[0121] C19-Zr: Elemental analysis: Measured (calculated) C, 67.70 (67.74); H, 5.71 (5.69); Cl, ​​8.36 (8.33); O, 7.54 (7.52); Zr, 10.75 (10.72).

[0122] C20-Zr: Elemental analysis: Measured (calculated) C, 67.65 (67.61); H, 5.34 (5.31); Cl, ​​8.51 (8.49); O, 7.65 (7.66); Zr, 10.90 (10.93).

[0123] The NMR characterization results of some metal complex catalysts are as follows:

[0124] C1-Zr: 1¹H NMR (400MHz, CDCl₃) δ 7.75(d, 2H), 7.73(s, 2H), 7.43(m, 4H), 7.37(t, 2H), 7.23(t, 2H), 7.20(d, 2H), 6.89(s, 2H), 6.71(d, 2H), 2.34(s, 6H), 2.15(s, 6H). Mass spectrometry: Calculated molecular weight: 712.77, Measured value: 712.03 [m] + ].

[0125] C2-Zr: 1 H NMR(400MHz, CDCl3)δ7.71(d,2H),7.53(s,2H),7.49(m,4H),7.36(t,2H),7. 31(t,2H),7.20(d,2H),6.89(s,2H),6.71(d,2H),2.15(s,6H),1.35(d,18H).

[0126] C3-Zr: 1 H NMR (400MHz, CDCl3) δ7.70(d,2H),7.51(s,2H),7.30(m,4H),7.29(t,2H),7.11(t,2H),7.00(d,2H),6.89(s,2H),6.71(d,2H),1.35(m,36H).

[0127] C5-Zr: 1 H NMR(400MHz, CDCl3)δ7.73(m,4H),7.43(m,4H),7.37(t,2H),7.23(t,2H),7.20(d,2H) ,6.89(s,2H),6.71(d,2H),2.55(m,2H),2.15(s,6H),1.20~1.50(m,10H),0.70(s,6H).

[0128] C6-Zr: 1 H NMR(400MHz, CDCl3)δ7.81(d,2H),7.51(s,2H),7.30(m,4H),7.29(t,2H),7.11(t,2 H),7.00(d,2H),6.89(s,2H),6.71(d,2H),2.15(s,6H),2.62(s,3H),1.35(m,36H).

[0129] Example 2

[0130] The synthetic routes for the catalysts C4-Zr, C16-Zr, and C17-Zr are as follows:

[0131]

[0132]

[0133] Step 1, Synthesis of Compound 11

[0134] Starting with compound 9, compound 10 was first prepared according to step 2 of Example 1, and then compound 11 was prepared according to step 4 of Example 1.

[0135] The second step is the synthesis of compound 12.

[0136] In a glove box at room temperature, compound 11 (23.9 mmol), bromocarbazole (28.7 mmol), 24 ml of 2M Na2CO3 aqueous solution, and 20 ml of dimethoxyethane were added to a 100 ml Shrek flask. Then, Pd(PPh3)4 (2.39 mmol) was weighed and added to the solution. The mixture was stirred and refluxed for 72 h. After the reaction was completed, 150 ml of ethyl acetate and 200 ml of deionized water were added to quench the reaction and the uppermost organic solvent layer was separated. 100 ml of hexane was added, and the mixture was filtered using filter paper. The filtrate was dried with MgSO4 and filtered again. The organic solvent was removed using a rotary evaporator, leaving a brown solid. The solid was separated by column chromatography (SiO2 powder as packing material, hexane / ethyl acetate volume ratio = 10:1) to obtain a pale yellow solid, which was compound 12.

[0137] The third step is the synthesis of compound 13.

[0138] Compound 13 was prepared using compound 12 as a raw material, following the first step of Example 1.

[0139] Step 4: Synthesis of compound C16-Zr

[0140] C16-Zr was prepared using compounds 6 and 13 as raw materials, following steps five through seven of Example 1.

[0141] C16-Zr: Elemental analysis: Measured (calculated) C, 72.15 (72.11); H, 4.80 (4.77); Cl, ​​6.48 (6.45); N, 2.58 (2.55); O, 5.85 (5.82); Zr, 8.33 (8.30).

[0142] Using similar raw materials, catalysts C4-Zr and C17-Zr were prepared respectively according to the above synthesis method.

[0143] C4-Zr: Elemental analysis: Measured (calculated) C, 70.99 (70.95); H, 3.97 (4.02); Cl, ​​6.99 (6.98); N, 2.76 (2.77); O, 6.30 (6.30); Zr, 8.99 (8.99).

[0144] C17-Zr: Elemental analysis: Measured (calculated) C, 73.39 (73.36); H, 5.69 (5.66); Cl, ​​5.90 (5.85); N, 2.34 (2.31); O, 5.25 (5.28); Zr, 7.55 (7.53).

[0145] The NMR characterization results of some metal complexes are as follows:

[0146] C4-Zr: 1 H NMR (400MHz, CDCl3) δ8.00(d,4H),7.70(d,2H),7.51~7.63(m,6H),7.50(t,4H),7. 29~7.30(m,10H),7.11(t,2H),7.00(d,2H),6.89(s,2H),6.71(d,2H),2.02(m,6H).

[0147] C16-Zr: 1 H NMR (400MHz, CDCl3) δ8.12(d,4H),7.70(d,2H),7.51~7.63(m,6H),7.50(t,4H),7.2 9~7.30(m,10H),7.11(t,2H),7.00(d,2H),6.89(s,2H),6.71(d,2H),1.35(m,18H).

[0148] C17-Zr: 1 H NMR(400MHz, CDCl3)δ7.84(d,4H),7.55~7.71(m,8H),7.50(t,4H),7.29~7.30(m,10 H),7.11(t,2H),7.00(d,2H),6.89(s,2H),6.71(d,2H),1.48(m,18H),1.35(m,18H).

[0149] Example 3

[0150] The catalyst C1-Hf-C20-Hf was prepared according to Examples 1 and 2, except that ZrCl4 was replaced with an equimolar amount of HfCl4.

[0151] Example 4

[0152] Different metal complexes prepared in the examples were selected as main catalysts to catalyze the copolymerization reaction of propylene and 1-hexene.

[0153] 2.5 ml of co-catalyst MAO (10 wt.% toluene solution), 200 ml of 1-hexene monomer that has undergone dehydration and deoxygenation treatment, and 400 ml of solvent Isopar E were mixed and added to a 1 L polymerization reactor. The polymerization reaction temperature was set to 140 °C. After the reactor reached the set temperature, propylene was introduced until the reactor pressure reached 24.6 bar. The temperature was maintained for 10 minutes. The main catalyst (0.2 μmol, dissolved in 2-10 ml toluene solution) was added to initiate the polymerization. The polymerization reaction time was 5 minutes. Industrial ethanol was added and thoroughly mixed to terminate the reaction. After precipitation, filtration, washing, and drying to constant weight, the propylene / 1-hexene copolymer was obtained. The characterization results are shown in Table 1.

[0154] Table 1

[0155]

[0156]

[0157] Example 5

[0158] Different metal complexes prepared in the examples were selected as main catalysts to catalyze the copolymerization reaction of propylene and ethylene.

[0159] 2.5 ml of co-catalyst MAO (10 wt.% toluene solution) and 400 ml of solvent Isopar E were mixed and added to a 1 L polymerization reactor. The polymerization temperature was set to 140 °C. After the reactor reached the set temperature, 3.0 bar of ethylene monomer was first introduced, followed by propylene until the reactor pressure reached 24.6 bar. The temperature was maintained for 10 minutes. Then, the main catalyst (0.2 μmol, dissolved in 2-10 ml of toluene solution) was added to initiate polymerization. The polymerization reaction was carried out for 5 minutes. Industrial ethanol was added and thoroughly mixed to terminate the reaction. The polymer was precipitated, filtered, washed, and dried to constant weight to obtain the propylene / ethylene copolymer. The characterization results are shown in Table 2.

[0160] Table 2

[0161]

[0162]

[0163] As can be seen from the results in Tables 1 and 2, when the metal complex containing naphthalene ring bridging described in this invention is used as the main catalyst for propylene copolymerization, it is possible to maintain high isotactic regularity (up to 99% mm) of the polypropylene segments in the polymer chain at relatively high polymerization temperatures (≥120℃), and the catalytic activity can also reach a very high level (up to 20 × 10⁻⁶). 7 The resulting polymer product has advantages such as adjustable molecular weight, narrow molecular weight distribution, and adjustable comonomer ratio (g / (mol metal))).

[0164] Unless otherwise specified, the terms used in this invention have the meanings commonly understood by those skilled in the art.

[0165] The embodiments described in this invention are for illustrative purposes only and are not intended to limit the scope of protection of this invention. Those skilled in the art can make various other substitutions, changes and improvements within the scope of this invention. Therefore, this invention is not limited to the above embodiments, but is only defined by the claims.

Claims

1. A metal complex comprising a naphthalene ring bridge, having a structure as shown in formula (Ⅰ): Equation (Ⅰ) In formula (Ⅰ), R1, R2, R3 and R4 each independently represent H, halogen, C1-C10 alkyl, C1-C10 alkoxy, C1-C10 haloalkyl, C1-C10 haloalkoxy, C3-C10 cycloalkyl or C6-C20 aryl; or any two groups of R1, R2, R3 and R4 are connected and fused with a naphthalene ring to form a substituted or unsubstituted C12-C16 aryl group. When a substituted group is represented, the substituent is selected from halogen, C1-C6 alkyl or C1-C6 alkoxy. R5 may be the same or different, R6 may be the same or different, and R5 and R6 may each independently represent halogen, C1-C10 alkyl, C1-C10 alkoxy, C1-C10 haloalkyl, C1-C10 haloalkoxy, C3-C10 cycloalkyl or 10-18 heteroaryl. M represents titanium (Ti), zirconium (Zr), or hafnium (Hf); X being the same or different indicates halogen.

2. The metal complex according to claim 1, characterized in that, In formula (Ⅰ), R1, R2, R3 and R4 each independently represent H, halogen, C1-C6 alkyl, C1-C6 alkoxy, C1-C6 haloalkyl, C1-C6 haloalkoxy, C3-C8 cycloalkyl or C6-C12 aryl; or any two groups of R1, R2, R3 and R4 are connected and fused with a naphthalene ring to form a substituted or unsubstituted C12-C16 aryl group. When a substituted group is represented, the substituent is selected from halogen or C1-C6 alkyl. R5 and R6 each independently represent a C1-C6 alkyl group or a 10-18 membered heteroaryl group; M represents Zr or Hf; X represents F, Cl, or Br.

3. The metal complex according to claim 1, characterized in that, In formula (Ⅰ), R1, R2, R3 and R4 each independently represent H, C1-C4 alkyl, C1-C4 alkoxy, C1-C4 haloalkyl, C1-C4 haloalkoxy or C6-C12 aryl; or in one or two groups of R1 and R2, R2 and R3, R3 and R4, two groups are connected and fused with a naphthalene ring to form a substituted or unsubstituted C12-C16 aryl group. When a substituted group is represented, the substituent is selected from halogen or C1-C4 alkyl. R5 and R6 each independently represent a C1-C4 alkyl group or a 10-15 membered heteroaryl group; M represents Zr or Hf; X represents Cl or Br.

4. The metal complex according to claim 1, characterized in that, R1, R2, R3, and R4 each independently represent H, methyl, ethyl, n-propyl, isopropyl, n-butyl, and 2. Methylbutyl, isobutyl, tert-butyl, methoxy, ethoxy, trifluoromethoxy, methyl or phenyl substituted with 1 to 3 chlorine or bromine atoms; Alternatively, any two groups of R1, R2, R3, and R4 may be linked together to form one of the following structures: , , , , , or ; R5 and R6 each independently represent methyl, ethyl, n-propyl, isopropyl, n-butyl, and 2... Methylbutyl, isobutyl, tert-butyl or carbazole.

5. The metal complex according to any one of claims 1-4, characterized in that, The metal complex is selected from one of the following compounds: Wherein, M represents Zr or Hf.

6. A ligand compound comprising a naphthalene ring bridge, having a structure as shown in formula (ⅠⅠ): Equation (ⅠⅠ) In formula (ⅠⅠ), R1 to R6 are each independently defined as in any one of claims 1-5.

7. A catalyst composition comprising a main catalyst and a co-catalyst, characterized in that, The main catalyst is the metal complex containing naphthalene ring bridging as described in any one of claims 1-5.

8. The catalyst composition according to claim 7, characterized in that, The co-catalyst is one or two of alkylaluminoxane and modified alkylaluminoxane.

9. The catalyst composition according to claim 8, characterized in that, The co-catalyst is one or both of methylaluminoxane and modified methylaluminoxane.

10. The catalyst composition according to any one of claims 7-9, characterized in that, The catalyst composition also includes a borate activator.

11. The catalyst composition according to claim 10, characterized in that, The borate activator is tetra(perfluorophenyl)boronic acid. N,N -One or both of dimethylaniline-onium and tetra(perfluorophenyl)borate-triphenylcarboonium.

12. Use of the metal complex comprising naphthalene ring bridging according to any one of claims 1-5, or the catalyst composition according to any one of claims 7-11, in the catalytic polymerization of olefins.

13. The use according to claim 12, characterized in that, The olefin is a straight-chain or branched olefin of C2 to C20.

14. The use according to claim 12, characterized in that, The olefin polymerization is propylene polymerization.

15. The use according to claim 14, characterized in that, The olefin polymerization is a homopolymerization of propylene, or a copolymerization of propylene with ethylene or C4-C20 α-olefins.

16. The use according to claim 15, characterized in that, The α-olefin is 1 Hexene or 1 Octene.

17. A method for olefin polymerization, characterized in that, The olefin monomers undergo polymerization under the catalytic action of the metal complex containing naphthalene ring bridging as described in any one of claims 1-5, or the catalyst composition as described in any one of claims 7-11.

18. The olefin polymerization method according to claim 17, characterized in that, The olefin is a straight-chain or branched olefin of C2 to C20.

19. The olefin polymerization method according to claim 17, characterized in that, The olefin polymerization is propylene polymerization.

20. The olefin polymerization method according to claim 19, characterized in that, The olefin polymerization is a homopolymerization of propylene, or a copolymerization of propylene with ethylene or C4-C20 α-olefins.

21. The olefin polymerization method according to claim 20, characterized in that, The α-olefin is 1 Hexene or 1 Octene.

22. The olefin polymerization method according to claim 17, characterized in that, The olefin polymerization is performed using solution polymerization.

23. The olefin polymerization method according to claim 22, characterized in that, The olefin is polymerized in an organic solvent.

24. The olefin polymerization method according to claim 23, characterized in that, The organic solvent is one or more of the following: ethers, aromatic hydrocarbons, alkanes, nitriles, and halogenated hydrocarbons.

25. The olefin polymerization method according to any one of claims 17-24, characterized in that, The polymerization reaction temperature is ≥100℃.

26. The olefin polymerization method according to claim 25, characterized in that, The polymerization reaction temperature is ≥120℃.

27. The olefin polymerization method according to claim 26, characterized in that, The polymerization reaction is carried out at a temperature of 120–160 °C.

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