IVB group metal organic complex as well as preparation method and application thereof

Abstract

The invention relates to the technical field of olefin polymerization catalysts, and discloses an IVB group metal organic complex as well as a preparation method and application thereof. The structural formula of the IVB group metal organic complex is as shown in formula (I). The IVB group metal organic complex disclosed by the invention is applied to olefin polymerization and has higher polymerization activity under similar polymerization conditions, the molecular weight of the obtained polymer is obviously higher than that of a polymer obtained in a contrast, the molecular weight distribution of the obtained polymer is wide, and the molecular weight of a catalyzed polymerization product is in bimodal distribution.

Description

[0001] Cross-references to related applications

[0002] This application claims the benefit of Chinese Patent Application No. 202411246382.6, filed on September 5, 2024, the contents of which are incorporated herein by reference. Technical Field

[0003] This invention relates to the field of olefin polymerization catalyst technology, specifically to a group IVB organometallic complex, its preparation method, and its application. Background Technology

[0004] Polyolefin resins have excellent environmental compatibility compared to other resin materials, and are therefore widely used in industry and daily life. Polyethylene resin is an important polyolefin resin. Industrially used polyethylene catalysts include Ziegler-Natta type catalysts (see, for example, DE Pat 889229 (1953); IT Pat 545332 (1956) and IT Pat 536899 (1955); Chem. Rev., 2000, 100, 1169 and related literature in this issue), Phillips type catalysts (for example, Belg. Pat. 530617 (1955); Chem. Rev. 1996, 96, 3327), and metallocene catalysts (for example, W. Kaminsky, Metalorganic Catalysts for Synthesis and Polymerization, Berlin: Springer, 1999), as well as the highly efficient ethylene oligomerization and polymerization catalysts of the post-transition metal complex type that have been rapidly developed in recent years. In recent years, Dow has reported on the catalytic copolymerization of ethylene / α-olefins using group IVB metal complexes based on imine-amine ligands. Among them, the complexes shown in Formula 1 and Formula 2 exhibit isomerization at higher temperatures (Organometallics 2011, 30(2), 251-262, Organometallics 2013, 32(21), 6488-6499), and have multiple active centers. Although the molecular weight of the polymerized product is high, the insertion rate of 1-octene is low, making it difficult to meet the basic requirements of elastomers. While the catalytic activity of the 8-aminoquinoline complex (as shown in Formula 3, Organometallics 2012, 31, 6244) is lower than that of the former, the insertion rate of 1-octene is higher. However, the reported polymerization temperature is relatively low, which is difficult to meet the requirements of industrial solution polymerization processes. Furthermore, in some applications of POE, such as toughening PP for automobiles, the requirements for POE flowability are becoming increasingly higher. Based on the current market situation, developing POE with high flowability and high melt index has become one of the new research directions.

[0005] Summary of the Invention

[0006] The purpose of this invention is to overcome the problems existing in the prior art and provide a group IVB organometallic complex. The synthesis of this group IVB organometallic complex is relatively simple. When this group IVB organometallic complex is used as the main catalyst for olefin polymerization, it has high catalytic activity and produces olefin polymers with high molecular weight and a wide molecular weight distribution range.

[0007] To achieve the above objectives, the present invention provides a group IVB organometallic complex, the structural formula of which is shown in formula (I):

[0008]

[0009] R1 and R2 are each independently selected from substituted or unsubstituted C1-C30 alkyl, C1-C30 alkoxy, substituted or unsubstituted C3-C30 cycloalkyl, C3-C30 cycloalkoxy, substituted or unsubstituted C6-C30 aryl and C6-C40 aryloxy;

[0010] R3 to R7 are each independently selected from hydrogen, substituted or unsubstituted C1 to C30 alkyl, substituted or unsubstituted C1 to C30 cycloalkyl, substituted or unsubstituted C1 to C30 alkoxy, substituted or unsubstituted C1 to C30 dialkylamino, substituted or unsubstituted C3 to C30 cycloalkoxy, substituted or unsubstituted C3 to C30 dicycloalkylamino, substituted or unsubstituted C6 to C40 aryl, substituted or unsubstituted C7 to C40 aryloxy, substituted or unsubstituted C6 to C40 arylamino, and substituted or unsubstituted C3 to C40 trialkylsilyl, or any two or more of R3 to R7 are linked together to form a cyclic structure.

[0011] X is selected from divalent substituents having 1 to 40 atoms, halogens, or C1 to C20 hydrocarbon groups;

[0012] n is 1 or 2;

[0013] M is selected from group IVB metals.

[0014] Preferably, R1 and R2 are each independently selected from C1-C20 alkyl, C1-C20 alkoxy, C3-C20 cycloalkyl, C3-C20 cycloalkoxy, substituted or unsubstituted C6-C30 aryl and C6-C30 aryloxy.

[0015] Preferably, R3 to R7 are each independently selected from hydrogen, substituted or unsubstituted C1 to C20 alkyl, C1 to C20 alkoxy, C1 to C20 dialkylamino, substituted or unsubstituted C3 to C20 cycloalkyl, C3 to C20 cycloalkoxy, C3 to C20 dicycloalkylamino, substituted or unsubstituted C6 to C30 aryl, C7 to C30 aryloxy, C6 to C30 arylamino, and C3 to C30 trialkylsilyl, or any two or more of R3 to R7 are linked together to form a cyclic structure.

[0016] Preferably, when n is 1, X is a divalent substituent having 1 to 40 atoms; when n is 2, X is a halogen or a C1 to C20 hydrocarbon group.

[0017] Preferably, M is selected from titanium, zirconium, or hafnium.

[0018] Preferably, R1 and R2 are each independently selected from C1-C20 alkyl, C1-C20 alkoxy, C3-C20 cycloalkoxy, substituted or unsubstituted C6-C30 aryl and C6-C30 aryloxy groups.

[0019] Preferably, R1 and R2 are each independently selected from C1-C6 alkyl, phenyl, substituted C7-C20 phenyl, naphthyl, substituted C7-C20 naphthyl, anthracene, indene, fluorenyl, phenoxy, substituted C7-C20 phenoxy, or substituted C7-C20 naphthoxy.

[0020] Preferably, R3 to R7 are each independently selected from hydrogen, substituted or unsubstituted C1 to C20 alkyl, substituted or unsubstituted C3 to C20 cycloalkyl, and substituted or unsubstituted C6 to C30 aryl, or any two or more of R3 to R7 are linked together to form a cyclic structure.

[0021] Preferably, when n is 1, X is selected from alkylene groups having 1 to 20 atoms, aryl groups having 1 to 20 atoms, diamino groups having 1 to 20 atoms, or dienes having 1 to 20 atoms; when n is 2, X is selected from halogens, substituted or unsubstituted C1 to C10 alkyl groups, and substituted or unsubstituted C1 to C10 aryl groups.

[0022] Preferably, M is selected from titanium, zirconium, or hafnium.

[0023] A second aspect of the present invention provides a method for preparing the above-mentioned group IVB organometallic complex, the method comprising:

[0024] In the presence of an organic solvent, the compound shown in formula (II) is reacted with a hydrogen-removing agent in the first reaction, followed by the addition of an M salt in the second reaction, and finally by the addition of an optional Grignard reagent in the reaction.

[0025]

[0026] Wherein, the M salt is a halide of a group IVB metal or a hydrocarbon compound of a group IVB metal;

[0027] The definitions of R1 to R7 are the same as those described above.

[0028] Preferably, the conditions for the first reaction include: a temperature of -78 to 35°C and a time of 1 to 24 hours.

[0029] Preferably, the molar ratio of the compound represented by formula (II) to the dehydrogenating agent is 1:2 to 5, more preferably 1:2 to 4.6.

[0030] Preferably, the hydrogen-removing agent is selected from one or more of sodium hydride, potassium hydride, lithium hydride, tetramethylethylenediamine, bis(trimethylsilylamino)lithium, bis(trimethylsilylamino)sodium, diisopropylaminolithium, and C1-C6 alkyllithium.

[0031] Preferably, the conditions for the second reaction include: a temperature of 60–120°C and a time of 1–30 h.

[0032] Preferably, the molar ratio of the compound represented by formula (II) to the metal M in the M salt is 1:2 to 3, more preferably 1:2 to 2.6.

[0033] Preferably, the organic solvent is selected from one or more of tetrahydrofuran, diethyl ether, pentane, cyclopentane, n-hexane, cyclohexane, heptane, methylcyclohexane, toluene, xylene, chlorobenzene, and o-dichlorobenzene.

[0034] Preferably, the method for preparing the compound shown in formula (II) includes the following steps:

[0035] (1) In the presence of a first solvent and formic acid and / or acetic acid, the compound shown in formula (V) and the compound shown in formula (IV) are subjected to a third reaction to obtain the compound shown in formula (III);

[0036] (2) In the presence of a second solvent, the compound shown in formula (III) and compound A are subjected to a fourth reaction;

[0037]

[0038] Wherein, compound A is LiR1 or Al(R1)3;

[0039] The definitions of R1 to R7 are the same as those described above.

[0040] Preferably, in step (1), the conditions for the third reaction include: a temperature of 50–120°C and a time of 4–24 h.

[0041] Preferably, in step (1), the molar ratio of the compound shown in formula (V) to the compound shown in formula (IV) is 1:2 to 8.

[0042] Preferably, in step (1), the first solvent is selected from one or more of methanol, ethanol, toluene, xylene, benzene, diethyl ether and tetrahydrofuran.

[0043] Preferably, in step (2), the conditions for the fourth reaction include: a temperature of -78 to 120°C and a time of 0.5 to 24 hours.

[0044] Preferably, in step (2), the molar ratio of the compound shown in formula (III) to compound A is 1:2 to 10.

[0045] Preferably, in step (2), the second solvent is selected from one or more of methanol, ethanol, toluene, xylene, benzene, diethyl ether and tetrahydrofuran.

[0046] A third aspect of the present invention provides the application of the above-mentioned group IVB organometallic complexes in olefin polymerization.

[0047] A fourth aspect of the present invention provides a catalyst for olefin polymerization, the catalyst comprising a main catalyst and a co-catalyst, wherein the main catalyst is the aforementioned group IVB organometallic complex;

[0048] The cocatalyst is selected from one or more of aluminoxanes, alkylaluminum compounds, alkylaluminum chlorides, alkylzinc compounds, and optionally organoboron compounds.

[0049] Preferably, the aluminum oxane is methylaluminoxane and / or modified methylaluminoxane.

[0050] Preferably, the alkylaluminum compound is selected from one or more of triethylaluminum, triisobutylaluminum, and trioctylaluminum.

[0051] Preferably, the alkylaluminum chloride is selected from one or more of monochloroethylaluminum, sesquiethylaluminum chloride, and dichloroethylaluminum.

[0052] Preferably, the organoboron compound is selected from one or more of triphenylmethyl tetra(pentafluorophenyl)borate, triphenylmethyl tetra(pentafluorophenyl)borate, tri(pentafluorophenyl)boron, N,N-dimethylaniline tetra(pentafluorophenyl)borate, dioctadecylmethyl tertiary amine tetra(pentafluorophenyl)borate, and dihydrogenated tallow methyl tertiary amine tetra(pentafluorophenyl)borate.

[0053] Preferably, the molar ratio of aluminum in the co-catalyst to metal M in the main catalyst is 1 to 10,000:1; the molar ratio of boron in the co-catalyst to metal M in the main catalyst is 0 to 10:1.

[0054] A fifth aspect of the present invention provides a method for olefin polymerization, comprising carrying out an olefin polymerization reaction in the presence of the catalyst described above for olefin polymerization.

[0055] Preferably, the polymerization temperature is -78℃ to 250℃, more preferably -20℃ to 200℃; the polymerization pressure is 0.1 to 100 atm, more preferably 0.1 to 50 atm.

[0056] Compared with the prior art, the technical solution of the present invention has the following advantages:

[0057] (1) The method for synthesizing group IVB organometallic complexes described in this invention is simple and easy to implement;

[0058] (2) The catalyst for olefin polymerization prepared by the group IVB organometallic complex described in this invention has high catalytic activity and can achieve near-active polymerization. The catalyzed polymerization product has high molecular weight and the molecular weight distribution of the catalyzed polymerization product can be effectively controlled. The molecular weight distribution range is wide (3≤PDI≤40). At the same time, the molecular weight of the catalyzed polymerization product exhibits a bimodal distribution.

[0059] (3) The catalyst for olefin polymerization prepared by the group IVB organometallic complex described in this invention has high catalytic activity and can catalyze olefin homopolymerization, ethylene / α-olefin copolymerization, and especially ethylene copolymerization with higher α-olefins. Detailed Implementation

[0060] The following provides a detailed description of specific embodiments of the present invention. It should be understood that the specific embodiments described herein are for illustrative and explanatory purposes only and are not intended to limit the scope of the invention.

[0061] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0062] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating relative importance or implying the number of technical features indicated. Therefore, unless otherwise stated, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature; "multiple" means two or more. The term "comprising" and any variations thereof mean non-exclusive inclusion, where one or more other features, integers, steps, operations, units, components, and / or combinations thereof may be present or added.

[0063] In one aspect, this invention provides a group IVB organometallic complex, the structural formula of which is shown in formula (I):

[0064]

[0065] R1 and R2 are each independently selected from substituted or unsubstituted C1-C30 alkyl, C1-C30 alkoxy, substituted or unsubstituted C3-C30 cycloalkyl, C3-C30 cycloalkoxy, substituted or unsubstituted C6-C30 aryl and C6-C40 aryloxy;

[0066] R3 to R7 are each independently selected from hydrogen, substituted or unsubstituted C1 to C30 alkyl, substituted or unsubstituted C1 to C30 cycloalkyl, substituted or unsubstituted C1 to C30 alkoxy, substituted or unsubstituted C1 to C30 dialkylamino, substituted or unsubstituted C3 to C30 cycloalkoxy, substituted or unsubstituted C3 to C30 dicycloalkylamino, substituted or unsubstituted C6 to C40 aryl, substituted or unsubstituted C7 to C40 aryloxy, substituted or unsubstituted C6 to C40 arylamino, and substituted or unsubstituted C3 to C40 trialkylsilyl, or any two or more of R3 to R7 are linked together to form a cyclic structure.

[0067] X is selected from divalent substituents having 1 to 40 atoms, halogens, or C1 to C20 hydrocarbon groups;

[0068] n is 1 or 2;

[0069] M is selected from group IVB metals.

[0070] In a preferred embodiment, R1 and R2 are each independently selected from C1-C20 alkyl, C1-C20 alkoxy, C3-C20 cycloalkyl, C3-C20 cycloalkoxy, substituted or unsubstituted C6-C30 aryl, and C6-C30 aryloxy.

[0071] In a more preferred embodiment, R1 and R2 are each independently selected from C1-C20 alkyl, C1-C20 alkoxy, C3-C20 cycloalkoxy, substituted or unsubstituted C6-C30 aryl, and C6-C30 aryloxy.

[0072] According to some specific embodiments of the present invention, R1 and R2 are each independently selected from C1-C6 alkyl, phenyl, substituted C7-C20 phenyl, naphthyl, substituted C7-C20 naphthyl, anthracene, indene, fluorenyl, phenoxy, substituted C7-C20 phenoxy or substituted C7-C20 naphthyloxy.

[0073] In a preferred embodiment, R3 to R7 are each independently selected from hydrogen, substituted or unsubstituted C1 to C20 alkyl, C1 to C20 alkoxy, C1 to C20 dialkylamino, substituted or unsubstituted C3 to C20 cycloalkyl, C3 to C20 cycloalkoxy, C3 to C20 dicycloalkylamino, substituted or unsubstituted C6 to C30 aryl, C7 to C30 aryloxy, C6 to C30 arylamino, and C3 to C30 trialkylsilyl, or any two or more of R3 to R7 are linked together to form a cyclic structure.

[0074] In a more preferred embodiment, R3 to R7 are each independently selected from hydrogen, substituted or unsubstituted C1 to C20 alkyl, substituted or unsubstituted C3 to C20 cycloalkyl, and substituted or unsubstituted C6 to C30 aryl, or any two or more of R3 to R7 are linked together to form a cyclic structure.

[0075] In a preferred embodiment, when n is 1, X is a divalent substituent having 1 to 40 atoms; when n is 2, X is a halogen or a C1 to C20 hydrocarbon group.

[0076] In a more preferred embodiment, when n is 1, X is selected from alkylene having 1 to 20 atoms, arylene having 1 to 20 atoms, diaminoimide having 1 to 20 atoms, or diene having 1 to 20 atoms; when n is 2, X is selected from halogens, substituted or unsubstituted C1 to C10 alkyl groups, and substituted or unsubstituted C1 to C10 aryl groups.

[0077] According to some specific embodiments of the present invention, when n is 1, X is 1,3-butadiene or 1,3-pentadiene; when n is 2, X is selected from halogen, methyl, benzyl or phenyl.

[0078] In a preferred embodiment, M is selected from titanium, zirconium, or hafnium.

[0079] In this invention, "substituted or unsubstituted" means containing a substituent, which can be selected from halogens, hydroxyl groups, C1-C6 alkyl groups, halogenated C1-C6 alkyl groups, C1-C6 alkoxy groups, or halogenated C1-C6 alkoxy groups.

[0080] In this invention, alkyl refers to straight-chain alkyl, branched alkyl, or cycloalkyl, including but not limited to: methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, tert-pentyl, neopentyl, n-hexyl, n-heptyl, n-octyl, n-decyl, cyclopropyl, cyclopentyl, cyclohexyl, 4-methylcyclohexyl, 4-ethylcyclohexyl, 4-n-propylcyclohexyl, and 4-n-butylcyclohexyl.

[0081] In this invention, the alkyl group (such as C1-C20 alkyl or C1-C6 alkyl) may be selected from methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, n-pentyl, isopentyl, n-hexyl, isohexyl or 3,3-dimethylbutyl.

[0082] In this invention, the alkoxy group (such as C1-C6 alkoxy or C1-C20 alkoxy) can be selected from methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, n-pentoxy, isopentoxy, n-hexyloxy, isohexyloxy, or 3,3-dimethylbutoxy.

[0083] In this invention, the aryl group (such as C6 to C30 aryl) can be selected from phenyl, 4-methylphenyl, 4-ethylphenyl, 2-methylphenyl, 2-isopropylphenyl or vinylphenyl.

[0084] In this invention, the halogen is selected from fluorine, chlorine, bromine or iodine.

[0085] In a further preferred embodiment, the group IVB organometallic complex is selected from the group consisting of:

[0086] Complex 1: The complex shown in formula (I), wherein R1 and R2 are methyl, R3 and R7 are isopropyl, R4 to R6 are H, M is Hf, X is Cl, and n is 2;

[0087] Complex 2: The complex shown in formula (I), wherein R1 and R2 are methyl, R3 and R7 are ethyl, R4 to R6 are H, M is Hf, X is Cl, and n is 2;

[0088] Complex 3: The complex shown in formula (I), wherein R1 and R2 are methyl groups, R3 and R7 are methyl groups, R4 to R6 are H, M is Hf, X is Cl, and n is 2;

[0089] Complex 4: The complex shown in formula (I), wherein R1 and R2 are methyl, R3, R5 and R7 are methyl, R4 and R6 are H, M is Hf, X is Cl, and n is 2;

[0090] Complex 5: The complex shown in formula (I), wherein R1 and R2 are methyl, R3 and R7 are phenyl, R4 to R6 are H, M is Hf, X is Cl, and n is 2;

[0091] Complex 6: The complex shown in formula (I), wherein R1 and R2 are methyl, R3 and R7 are cyclohexyl, R4 to R6 are H, M is Hf, X is Cl, and n is 2;

[0092] Complex 7: The complex shown in formula (I), wherein R1 and R2 are methyl, R3 and R7 are trifluoromethyl, R4 to R6 are H, M is Hf, X is Cl, and n is 2;

[0093] Complex 8: The complex shown in formula (I), wherein R1 and R2 are methyl, R3 and R7 are isopropyl, R4 to R6 are H, M is Hf, X is methyl, and n is 2;

[0094] Complex 9: The complex shown in formula (I), wherein R1 and R2 are methyl, R3 and R7 are ethyl, R4 to R6 are H, M is Hf, X is methyl, and n is 2;

[0095] Complex 10: The complex shown in formula (I), wherein R1 and R2 are methyl, R3 and R7 are methyl, R4 to R6 are H, M is Hf, X is methyl, and n is 2;

[0096] Complex 11: The complex shown in formula (I), wherein R1 and R2 are methyl, R3, R5 and R7 are methyl, R4 and R6 are H, M is Hf, X is methyl, and n is 2;

[0097] Complex 12: The complex shown in formula (I), wherein R1 and R2 are methyl, R3 and R7 are phenyl, R4 to R6 are H, M is Hf, X is methyl, and n is 2;

[0098] Complex 13: The complex shown in formula (I), wherein R1 and R2 are methyl groups, R3 and R7 are cyclohexyl groups, R4 to R6 are H groups, M is Hf, X is methyl, and n is 2;

[0099] Complex 14: The complex shown in formula (I), wherein R1 and R2 are methyl, R3 and R7 are trifluoromethyl, R4 to R6 are H, M is Hf, X is methyl, and n is 2;

[0100] Complex 15: The complex shown in formula (I), wherein R1 and R2 are methyl, R3 and R7 are isopropyl, R4 to R6 are H, M is Hf, X is benzyl, and n is 2;

[0101] Complex 16: The complex shown in formula (I), wherein R1 and R2 are methyl, R3 and R7 are ethyl, R4 to R6 are H, M is Hf, X is benzyl, and n is 2;

[0102] Complex 17: The complex shown in formula (I), wherein R1 and R2 are methyl, R3 and R7 are methyl, R4 to R6 are H, M is Hf, X is benzyl, and n is 2;

[0103] Complex 18: The complex shown in formula (I), wherein R1 and R2 are methyl, R3, R5 and R7 are methyl, R4 and R6 are H, M is Hf, X is benzyl, and n is 2;

[0104] Complex 19: The complex shown in formula (I), wherein R1 and R2 are methyl, R3 and R7 are phenyl, R4 to R6 are H, M is Hf, X is benzyl, and n is 2;

[0105] Complex 20: The complex shown in formula (I), wherein R1 and R2 are methyl, R3 and R7 are cyclohexyl, R4 to R6 are H, M is Hf, X is benzyl, and n is 2;

[0106] Complex 21: The complex shown in formula (I), wherein R1 and R2 are methyl, R3 and R7 are trifluoromethyl, R4 to R6 are H, M is Hf, X is benzyl, and n is 2;

[0107] Complex 22: The complex shown in formula (I), wherein R1 is phenyl, R2 is methyl, R3 and R7 are isopropyl, R4 to R6 are H, M is Hf, X is Cl, and n is 2;

[0108] Complex 23: The complex shown in formula (I), wherein R1 is phenyl, R2 is methyl, R3 and R7 are ethyl, R4 to R6 are H, M is Hf, X is Cl, and n is 2;

[0109] Complex 24: The complex shown in formula (I), wherein R1 is phenyl, R2 is methyl, R3 and R7 are methyl, R4 to R6 are H, M is Hf, X is Cl, and n is 2;

[0110] Complex 25: The complex shown in formula (I), wherein R1 is phenyl, R2 is methyl, R3, R5 and R7 are methyl, R4 and R6 are H, M is Hf, X is Cl and n is 2;

[0111] Complex 26: The complex shown in formula (I), wherein R1 is phenyl, R2 is methyl, R3 and R7 are phenyl, R4 to R6 are H, M is Hf, X is Cl, and n is 2;

[0112] Complex 27: The complex shown in formula (I), wherein R1 is phenyl, R2 is methyl, R3 and R7 are cyclohexyl, R4 to R6 are H, M is Hf, X is Cl, and n is 2;

[0113] Complex 28: The complex shown in formula (I), wherein R1 is phenyl, R2 is methyl, R3 and R7 are trifluoromethyl, R4 to R6 are H, M is Hf, X is Cl, and n is 2;

[0114] Complex 29: The complex shown in formula (I), wherein R1 is phenyl, R2 is methyl, R3 and R7 are isopropyl, R4 to R6 are H, M is Hf, X is methyl, and n is 2;

[0115] Complex 30: The complex shown in formula (I), wherein R1 is phenyl, R2 is methyl, R3 and R7 are ethyl, R4 to R6 are H, M is Hf, X is methyl, and n is 2;

[0116] Complex 31: The complex shown in formula (I), wherein R1 is phenyl, R2 is methyl, R3 and R7 are methyl, R4 to R6 are H, M is Hf, X is methyl, and n is 2;

[0117] Complex 32: The complex shown in formula (I), wherein R1 is phenyl, R2 is methyl, R3, R5 and R7 are methyl, R4 and R6 are H, M is Hf, X is methyl, and n is 2;

[0118] Complex 33: The complex shown in formula (I), wherein R1 is phenyl, R2 is methyl, R3 and R7 are phenyl, R4 to R6 are H, M is Hf, X is methyl, and n is 2;

[0119] Complex 34: The complex shown in formula (I), wherein R1 is phenyl, R2 is methyl, R3 and R7 are cyclohexyl, R4 to R6 are H, M is Hf, X is methyl, and n is 2;

[0120] Complex 35: The complex shown in formula (I), wherein R1 is phenyl, R2 is methyl, R3 and R7 are trifluoromethyl, R4 to R6 are H, M is Hf, X is methyl, and n is 2;

[0121] Complex 36: The complex shown in formula (I), wherein R1 is phenyl, R2 is methyl, R3 and R7 are isopropyl, R4 to R6 are H, M is Hf, X is benzyl, and n is 2;

[0122] Complex 37: The complex shown in formula (I), wherein R1 is phenyl, R2 is methyl, R3 and R7 are ethyl, R4 to R6 are H, M is Hf, X is benzyl, and n is 2;

[0123] Complex 38: The complex shown in formula (I), wherein R1 is phenyl, R2 is methyl, R3 and R7 are methyl, R4 to R6 are H, M is Hf, X is benzyl, and n is 2;

[0124] Complex 39: The complex shown in formula (I), wherein R1 is phenyl, R2 is methyl, R3, R5 and R7 are methyl, R4 and R6 are H, M is Hf, X is benzyl, and n is 2;

[0125] Complex 40: The complex shown in formula (I), wherein R1 is phenyl, R2 is methyl, R3 and R7 are phenyl, R4 to R6 are H, M is Hf, X is benzyl, and n is 2;

[0126] Complex 41: The complex shown in formula (I), wherein R1 is phenyl, R2 is methyl, R3 and R7 are cyclohexyl, R4 to R6 are H, M is Hf, X is benzyl, and n is 2;

[0127] Complex 42: The complex shown in formula (I), wherein R1 is phenyl, R2 is methyl, R3 and R7 are trifluoromethyl, R4 to R6 are H, M is Hf, X is benzyl, and n is 2;

[0128] Complex 43: The complex shown in formula (I), wherein R1 and R2 are methyl, R3 and R7 are isopropyl, R4 to R6 are H, M is Zr, X is Cl, and n is 2;

[0129] Complex 44: The complex shown in formula (I), wherein R1 and R2 are methyl, R3 and R7 are ethyl, R4 to R6 are H, M is Zr, X is Cl, and n is 2;

[0130] Complex 45: The complex shown in formula (I), wherein R1 and R2 are methyl, R3 and R7 are methyl, R4 to R6 are H, M is Zr, X is Cl, and n is 2;

[0131] Complex 46: The complex shown in formula (I), wherein R1 and R2 are methyl, R3, R5 and R7 are methyl, R4 and R6 are H, M is Zr, X is Cl, and n is 2;

[0132] Complex 47: The complex shown in formula (I), wherein R1 and R2 are methyl, R3 and R7 are phenyl, R4 to R6 are H, M is Zr, X is Cl, and n is 2;

[0133] Complex 48: The complex shown in formula (I), wherein R1 and R2 are methyl, R3 and R7 are cyclohexyl, R4 to R6 are H, M is Zr, X is Cl, and n is 2;

[0134] Complex 49: The complex shown in formula (I), wherein R1 and R2 are methyl, R3 and R7 are trifluoromethyl, R4 to R6 are H, M is Zr, X is Cl, and n is 2;

[0135] Complex 50: The complex shown in formula (I), wherein R1 and R2 are methyl, R3 and R7 are isopropyl, R4 to R6 are H, M is Zr, X is methyl, and n is 2;

[0136] Complex 51: The complex shown in formula (I), wherein R1 and R2 are methyl, R3 and R7 are ethyl, R4 to R6 are H, M is Zr, X is methyl, and n is 2;

[0137] Complex 52: The complex shown in formula (I), wherein R1 and R2 are methyl, R3 and R7 are methyl, R4 to R6 are H, M is Zr, X is methyl, and n is 2;

[0138] Complex 53: The complex shown in formula (I), wherein R1 and R2 are methyl, R3, R5 and R7 are methyl, R4 and R6 are H, M is Zr, X is methyl, and n is 2;

[0139] Complex 54: The complex shown in formula (I), wherein R1 and R2 are methyl, R3 and R7 are phenyl, R4 to R6 are H, M is Zr, X is methyl, and n is 2;

[0140] Complex 55: The complex shown in formula (I), wherein R1 and R2 are methyl, R3 and R7 are cyclohexyl, R4 to R6 are H, M is Zr, X is methyl, and n is 2;

[0141] Complex 56: The complex shown in formula (I), wherein R1 and R2 are methyl, R3 and R7 are trifluoromethyl, R4 to R6 are H, M is Zr, X is methyl, and n is 2;

[0142] Complex 57: The complex shown in formula (I), wherein R1 is phenyl, R2 is methyl, R3 and R7 are isopropyl, R4 to R6 are H, M is Zr, X is Cl, and n is 2;

[0143] Complex 58: The complex shown in formula (I), wherein R1 is phenyl, R2 is methyl, R3 and R7 are ethyl, R4 to R6 are H, M is Zr, X is C, and n is 2l;

[0144] Complex 59: The complex shown in formula (I), wherein R1 is phenyl, R2 is methyl, R3 and R7 are methyl, R4 to R6 are H, M is Zr, X is Cl, and n is 2;

[0145] Complex 60: The complex shown in formula (I), wherein R1 is phenyl, R2 is methyl, R3, R5 and R7 are methyl, R4 and R6 are H, M is Zr, X is Cl, and n is 2;

[0146] Complex 61: The complex shown in formula (I), wherein R1 is phenyl, R2 is methyl, R3 and R7 are phenyl, R4 to R6 are H, M is Zr, X is Cl, and n is 2;

[0147] Complex 62: The complex shown in formula (I), wherein R1 is phenyl, R2 is methyl, R3 and R7 are cyclohexyl, R4 to R6 are H, M is Zr, X is Cl, and n is 2;

[0148] Complex 63: The complex shown in formula (I), wherein R1 is phenyl, R2 is methyl, R3 and R7 are trifluoromethyl, R4 to R6 are H, M is Zr, X is Cl, and n is 2;

[0149] Complex 64: The complex shown in formula (I), wherein R1 is phenyl, R2 is methyl, R3 and R7 are isopropyl, R4 to R6 are H, M is Zr, X is methyl, and n is 2;

[0150] Complex 65: The complex shown in formula (I), wherein R1 is phenyl, R2 is methyl, R3 and R7 are ethyl, R4 to R6 are H, M is Zr, X is methyl, and n is 2;

[0151] Complex 66: The complex shown in formula (I), wherein R1 is phenyl, R2 is methyl, R3 and R7 are methyl, R4 to R6 are H, M is Zr, X is methyl, and n is 2;

[0152] Complex 67: The complex shown in formula (I), wherein R1 is phenyl, R2 is methyl, R3, R5 and R7 are methyl, R4 and R6 are H, M is Zr, X is methyl, and n is 2;

[0153] Complex 68: The complex shown in formula (I), wherein R1 is phenyl, R2 is methyl, R3 and R7 are phenyl, R4 to R6 are H, M is Zr, X is methyl, and n is 2;

[0154] Complex 69: The complex shown in formula (I), wherein R1 is phenyl, R2 is methyl, R3 and R7 are cyclohexyl, R4 to R6 are H, M is Zr, X is methyl, and n is 2;

[0155] Complex 70: The complex shown in formula (I), wherein R1 is phenyl, R2 is methyl, R3 and R7 are trifluoromethyl, R4 to R6 are H, M is Zr, X is methyl, and n is 2;

[0156] Complex 71: The complex shown in formula (I), wherein R1 and R2 are methyl, R3 and R7 are cyclohexyl, R4 to R6 are H, M is Ti, X is methyl, and n is 2;

[0157] Complex 72: The complex shown in formula (I), wherein R1 is phenyl, R2 is methyl, R3 and R7 are cyclohexyl, R4 to R6 are H, M is Ti, X is methyl, and n is 2.

[0158] A second aspect of the present invention provides a method for preparing the above-mentioned group IVB organometallic complex, the method comprising:

[0159] In the presence of an organic solvent, the compound shown in formula (II) is reacted with a hydrogen-removing agent in the first reaction, followed by the addition of an M salt in the second reaction, and finally by the addition of an optional Grignard reagent in the reaction.

[0160]

[0161] Wherein, the M salt is a halide of a group IVB metal or a hydrocarbon compound of a group IVB metal; the definitions of R1 to R7 are the same as those described above.

[0162] In the method for preparing the above-mentioned group IVB organometallic complexes of the present invention, there are no special requirements for the organic solvent, and any organic solvent conventionally used in the art is acceptable; in a preferred embodiment, the organic solvent is selected from one or more of tetrahydrofuran, diethyl ether, pentane, cyclopentane, n-hexane, cyclohexane, heptane, methylcyclohexane, toluene, xylene, chlorobenzene and o-dichlorobenzene.

[0163] In a preferred embodiment, in order to improve the yield of the compound shown in formula (I), the conditions for the first reaction include: a temperature of -78 to 35°C and a time of 1 to 24 h; preferably: a temperature of -78 to 20°C and a time of 1 to 24 h; specifically, the temperature can be -78°C, -50°C, -20°C, 0°C or 20°C; the time can be 1 h, 5 h, 10 h, 15 h, 20 h or 24 h.

[0164] In a preferred embodiment, in order to further improve the yield of the compound shown in formula (I), the molar ratio of the compound shown in formula (II) to the dehydrogenating agent is 1:2 to 5, preferably 1:2 to 4.6; specifically, the molar ratio of the compound shown in formula (II) to the dehydrogenating agent can be 1:2, 1:2.5, 1:3, 1:3.5, 1:4 or 1:4.6.

[0165] In a preferred embodiment, the hydrogen-removing agent is selected from one or more of sodium hydride, potassium hydride, lithium hydride, tetramethylethylenediamine, bis(trimethylsilylamino)lithium, bis(trimethylsilylamino)sodium, diisopropylaminolithium, and C1-C6 alkyllithium.

[0166] In a preferred embodiment, in order to improve the yield of the compound shown in formula (I), the conditions for the second reaction include: a temperature of 60–120°C and a time of 1–30 h; preferably: a temperature of 70–120°C and a time of 1–12 h; specifically, the temperature can be 70°C, 80°C, 90°C, 100°C, 110°C or 120°C; and the time can be 1 h, 2 h, 4 h, 6 h, 8 h, 10 h or 12 h.

[0167] In a preferred embodiment, in order to further improve the yield of the compound shown in formula (I), the molar ratio of the compound shown in formula (II) to the metal M in the M salt is 1:2 to 3, preferably 1:2 to 2.6; specifically, the molar ratio of the compound shown in formula (II) to the metal M in the M salt can be 1:2, 1:2.2, 1:2.4 or 1:2.6.

[0168] In a preferred embodiment, the M salt is selected from titanium halides, titanium hydrocarbon compounds, zirconium halides, zirconium hydrocarbon compounds, hafnium halides, or hafnium hydrocarbon compounds.

[0169] In a specific embodiment, the M salt is selected from hafnium tetrachloride, zirconium tetrachloride, titanium tetrachloride, tetrabenzyl hafnium, tetrabenzyl zirconium, or tetrabenzyl titanium.

[0170] In a preferred embodiment, the method for preparing the above-mentioned group IVB organometallic complex includes:

[0171] In the presence of an organic solvent, the compound shown in formula (II) is reacted with a dehydrogenating agent in a first reaction, and then the M salt is added to carry out a second reaction;

[0172]

[0173] Wherein, the M salt is a halide of a group IVB metal or a hydrocarbon compound of a group IVB metal; the definitions of R1 to R7 are the same as those described above.

[0174] In one embodiment, the reaction process for preparing the above-mentioned Group IVB organometallic complex is shown in the following reaction formula:

[0175]

[0176] Wherein, the M salt is a halide of a group IVB metal or a hydrocarbon compound of a group IVB metal; the definitions of M, X, n, R1 to R7 are the same as those described above.

[0177] In one specific embodiment, the preparation process of the above-mentioned group IVB organometallic complex includes: in the presence of an organic solvent (e.g., toluene), reacting the compound shown in formula (II) with a hydrogen-removing agent (e.g., n-butyllithium), then adding an M salt (e.g., hafnium tetrachloride) to carry out a second reaction, filtering, drying the toluene and washing with dry n-hexane to obtain the compound shown in formula (I).

[0178] In another embodiment, the method for preparing the above-mentioned group IVB organometallic complexes in which X is non-halogen includes:

[0179] In the presence of an organic solvent, the compound shown in formula (II) is reacted with a dehydrogenating agent in the first reaction, followed by the addition of M salt in the second reaction, and then the addition of Grignard reagent in the reaction.

[0180]

[0181] Wherein, the M salt is a halide of a group IVB metal or a hydrocarbon compound of a group IVB metal; the definitions of R1 to R7 are the same as those described above.

[0182] In a preferred embodiment, the reaction process for preparing the above-mentioned group IVB organometallic complexes where X is non-halogen is shown in the following reaction formula:

[0183]

[0184] Wherein, the M salt is a halide of a group IVB metal or a hydrocarbon compound of a group IVB metal; the definitions of M, n, R1 to R7 are the same as described above, and the definition of X is the same as described above, and X is non-halogen.

[0185] In a preferred embodiment, in order to improve the yield of the compound shown in formula (I), the molar ratio of the compound shown in formula (II) to the Grignard reagent is 1:6-10; preferably 1:6-8; specifically, the molar ratio of the compound shown in formula (II) to the Grignard reagent can be 1:6, 1:6.1, 1:6.2, 1:6.3, 1:6.4, 1:6.5, 1:6.6, 1:6.7, 1:6.8, 1:6.9, 1:7, 1:7.2, 1:7.4, 1:7.6, 1:7.8, or 1:8.

[0186] In a preferred embodiment, in order to improve the yield of the compound shown in formula (I), the reaction conditions include a temperature of 20-80°C and a time of 6-24 h.

[0187] In one specific embodiment, the preparation process of the above-mentioned group IVB organometallic complex includes: in the presence of an organic solvent (e.g., toluene), the compound shown in formula (II) is reacted with a hydrogen-removing agent (e.g., n-butyllithium), followed by the addition of an M salt (e.g., hafnium tetrachloride) for a second reaction, then the addition of a Grignard reagent (e.g., methyl magnesium bromide), stirring at 25°C for 12 h, drying the toluene, adding 15 mL of dry n-hexane, allowing it to stand, filtering and washing with dry n-hexane, drying the filtrate, adding another 15 mL of dry toluene, filtering and collecting the filtrate, and drying the solvent to obtain the compound shown in formula (I).

[0188] In a preferred embodiment, the method for preparing the compound of formula (II) includes the following steps:

[0189] (1) In the presence of a first solvent and formic acid and / or acetic acid, the compound shown in formula (V) and the compound shown in formula (IV) are subjected to a third reaction to obtain the compound shown in formula (III);

[0190] (2) In the presence of a second solvent, the compound shown in formula (III) and compound A are subjected to a fourth reaction;

[0191]

[0192] Wherein, compound A is LiR1 or Al(R1)3; the definitions of R1 to R7 are the same as those described above.

[0193] In the method for preparing the compound of formula (II) according to the present invention, step (1) is carried out under a protective atmosphere selected from nitrogen atmosphere, helium atmosphere, neon atmosphere or argon atmosphere; step (2) is carried out under oxygen-free conditions.

[0194] In the method for preparing the compound of formula (II) according to the present invention, in step (1), the reaction process of the third reaction is as shown in the following reaction formula:

[0195]

[0196] The definitions of R2 to R7 are the same as those described above.

[0197] In a preferred embodiment, in step (1), the conditions for the third reaction include: a temperature of 50 to 120°C and a time of 4 to 24 hours; specifically, the temperature can be 50°C, 80°C, 100°C or 120°C; and the time can be 4 hours, 8 hours, 12 hours, 16 hours, 20 hours or 24 hours.

[0198] In a preferred embodiment, in order to further improve the yield of the compound shown in formula (III), in step (1), the molar ratio of the compound shown in formula (V) to the compound shown in formula (IV) is 1:2 to 8; specifically, the molar ratio of the compound shown in formula (V) to the compound shown in formula (IV) can be 1:2, 1:2.5, 1:3, 1:4, 1:5, 1:6, 1:7 or 1:8.

[0199] In a preferred embodiment, in step (1), the first solvent is selected from one or more of methanol, ethanol, toluene, xylene, benzene, diethyl ether and tetrahydrofuran.

[0200] In a preferred embodiment, step (1) further includes separating and purifying the material after the first reaction, wherein the separation and purification method is column chromatography or recrystallization.

[0201] In one specific embodiment, the preparation process of step (1) includes: dissolving the compound shown in formula (V) in a first solvent (e.g., methanol) in a protective gas atmosphere (e.g., nitrogen), adding the compound shown in formula (IV) (e.g., 2,6-diisopropylaniline) and formic acid at room temperature, heating to 80°C and stirring under reflux for 4 hours, removing 2,6-diisopropylaniline and methanol by vacuum distillation, then precipitating and washing with ethanol, and recrystallizing by dichloromethane / petroleum ether to obtain the compound shown in formula (III).

[0202] In the method for preparing the compound of formula (II) according to the present invention, in step (2), the reaction process of the fourth reaction is shown in the following reaction formula:

[0203]

[0204] The definitions of R1 to R7 are the same as those described above.

[0205] In a preferred embodiment, in order to improve the yield of the compound shown in formula (II), the conditions for the fourth reaction in step (2) include: a temperature of -78 to 120°C and a time of 0.5 to 24 h; specifically, the temperature can be -78°C, -50°C, -20°C, 0°C, 10°C, 35°C, 50°C, 65°C, 80°C, 95°C, 110°C or 120°C; and the time can be 0.5 h, 4 h, 8 h, 12 h, 16 h, 20 h or 24 h.

[0206] In a preferred embodiment, in order to further improve the yield of the compound shown in formula (II), in step (2), the molar ratio of the compound shown in formula (III) to the compound A is 1:2 to 10; preferably 1:2 to 8; more preferably 1:2 to 6; specifically, the molar ratio of the compound shown in formula (III) to the compound A can be 1:2, 1:2.5, 1:3, 1:3.5, 1:4, 1:4.5, 1:5, 1:5.5 or 1:6.

[0207] In a specific implementation, the LiR1 can be phenyl lithium, 2-isopropylphenyl lithium, 2-methyl-phenyl lithium, or tert-butyl lithium.

[0208] In a specific embodiment, Al(R1)3 can be trimethylaluminum, triethylaluminum, triisobutylaluminum, triphenylaluminum or tritert-butylaluminum.

[0209] In a preferred embodiment, in step (2), the second solvent is selected from one or more of methanol, ethanol, toluene, xylene, benzene, diethyl ether and tetrahydrofuran.

[0210] In a preferred embodiment, step (2) further includes separating and purifying the material after the second reaction, wherein the separation and purification method is column chromatography or recrystallization.

[0211] In one specific embodiment, the preparation process of step (2) includes: under anaerobic conditions, dissolving the compound shown in formula (III) in a second solvent (e.g., tetrahydrofuran) at room temperature, cooling to -78°C and adding LiR1 (e.g., phenyl lithium) dropwise, after the addition is complete, heating to room temperature and stirring for 3 hours, adding ammonium chloride aqueous solution to terminate the reaction, and then extracting the organic phase with ethyl acetate, and separating the organic phase by silica gel gel chromatography to obtain the compound shown in formula (II).

[0212] In another specific embodiment, the preparation process of step (2) includes: under anaerobic conditions, dissolving the compound shown in formula (III) in a second solvent (e.g., toluene) at room temperature, cooling to -78°C and adding Al(R1)3 (e.g., trimethylaluminum) dropwise, after the addition is complete, heating to reflux and stirring for 3 hours, adding ammonium chloride aqueous solution to terminate the reaction, and then extracting the organic phase with ethyl acetate, and separating the organic phase by silica gel gel chromatography to obtain the compound shown in formula (II).

[0213] A third aspect of the present invention provides the application of the above-mentioned group IVB organometallic complexes in olefin polymerization.

[0214] In a preferred embodiment, the olefin is selected from ethylene and / or α-olefins.

[0215] In a more preferred embodiment, the α-olefin is selected from one or more of propylene, butene, pentene, 1-hexene, 1-octene, 1-decene, and 4-methyl-1-pentene.

[0216] A fourth aspect of the present invention provides a catalyst for olefin polymerization, the catalyst comprising a main catalyst and a co-catalyst, wherein the main catalyst is the aforementioned group IVB organometallic complex;

[0217] The cocatalyst is selected from one or more of aluminoxanes, alkylaluminum compounds, alkylaluminum chlorides, alkylzinc compounds, and optionally organoboron compounds.

[0218] In a preferred embodiment, the aluminum oxane is methylaluminoxane and / or modified methylaluminoxane.

[0219] In a preferred embodiment, the alkylaluminum compound is selected from one or more of triethylaluminum, triisobutylaluminum, and trioctylaluminum.

[0220] In a preferred embodiment, the alkylaluminum chloride is selected from one or more of monochloroethylaluminum, sesquiethylaluminum chloride, and dichloroethylaluminum.

[0221] In a preferred embodiment, the organoboron compound is selected from one or more of triphenylmethyl tetra(pentafluorophenyl)borate, triphenylmethyl tetra(pentafluorophenyl)borate, tri(pentafluorophenyl)boron, N,N-dimethylaniline tetra(pentafluorophenyl)borate, dioctadecylmethyl tertiary amine tetra(pentafluorophenyl)borate, and dihydrogenated tallow methyl tertiary amine tetra(pentafluorophenyl)borate.

[0222] In a preferred embodiment, the molar ratio of aluminum in the co-catalyst to metal M in the main catalyst is 1 to 10,000:1; the molar ratio of boron in the co-catalyst to metal M in the main catalyst is 0 to 10:1.

[0223] In a more preferred embodiment, the molar ratio of aluminum in the co-catalyst to metal M in the main catalyst is 3 to 1000:1; the molar ratio of boron in the co-catalyst to metal M in the main catalyst is 0 to 4:1.

[0224] In specific embodiments, the molar ratio of aluminum in the co-catalyst to metal M in the main catalyst can be 3:1, 10:1, 100:1, 500:1 or 1000:1; the molar ratio of boron in the co-catalyst to metal M in the main catalyst can be 0:1, 1:1, 2:1, 3:1 or 4:1.

[0225] A fifth aspect of the present invention provides a method for olefin polymerization, comprising carrying out an olefin polymerization reaction in the presence of the catalyst described above for olefin polymerization.

[0226] In a preferred embodiment, the polymerization temperature is -78°C to 250°C, more preferably -20°C to 200°C; the polymerization pressure is 0.1 to 100 atm, more preferably 0.1 to 50 atm.

[0227] In specific embodiments, the polymerization temperature can be -20℃, -10℃, 0℃, 50℃, 100℃, 120℃, 140℃, 160℃, 180℃ or 200℃; the polymerization pressure can be 0.1atm, 1atm, 4atm, 10atm, 20atm or 50atm.

[0228] In this invention, "polymerization pressure" refers to the ethylene pressure in the polymerization system, expressed as absolute pressure.

[0229] According to some embodiments of the present invention, the polymerization reaction is carried out by olefin monomers in a solvent, the solvent being independently selected from one or more of alkanes, aromatic hydrocarbons and halogenated hydrocarbons.

[0230] According to some specific embodiments of the present invention, the polymerization solvent is independently selected from one or more of hexane, pentane, heptane, decane, benzene, toluene, dichloromethane, chloroform and dichloroethane, more preferably from one or more of hexane, decane, toluene and heptane.

[0231] The following examples further illustrate the group IVB organometallic complex, its preparation method, and its applications according to the present invention. The examples are implemented based on the technical solution of the present invention, providing detailed implementation methods and specific operating procedures; however, the scope of protection of the present invention is not limited to the following examples.

[0232] Unless otherwise specified, the experimental methods used in the following embodiments are conventional methods in the art. Unless otherwise specified, the experimental materials used in the following embodiments are commercially available.

[0233] (1) Nuclear magnetic resonance spectrometer: Bruker DMX 300 (300MHz), with tetramethylsilicon (TMS) as internal standard;

[0234] (2) Characterization of polymer molecular weight and molecular weight distribution: Molecular weight and its distribution were determined by gel permeation chromatography (GPC) using a PL-GPC220 chromatograph. The polymer samples were dissolved in 1,2,4-trichlorobenzene at 150℃, with a sample concentration of 1 mg / mL and a solvent flow rate of 1.0 mL / min. The chromatographic column was 3×PLgel 10 μm M1×ED-B300×7.5 nm. Each sample was measured twice.

[0235] (3) Activity measurement method: The polymer was washed with hydrochloric acid ethanol solution, vacuum dried, and the weight of the polymer was obtained; the polymerization activity was calculated as: polymer weight (g) / metal M (mol) × 60 / polymerization time (min);

[0236] (4) Structure analysis of coordination compounds: Single crystal testing and analysis were performed using a Rigaku RAXIS Rapid IP diffractometer;

[0237] (5) Analysis of comonomer content in the polymer: using... 1 H NMR, 13 C NMR spectroscopy was performed on a 400MHz Bruker Avance 400 NMR spectrometer using a 10mm PASEX 13 probe at 120°C to analyze polymer samples dissolved in 1,2,4-trichlorobenzene.

[0238] Example 1

[0239] Complex 8: The complex shown in formula (I), wherein R1 and R2 are methyl, R3 and R7 are isopropyl, R4 to R6 are H, M is Hf, X is methyl, and n is 2;

[0240] In a nitrogen atmosphere, the compound shown in formula (V) (J.Am.Chem.Soc.2020,142,12,5819-5824) (11.10 g, 0.035 mol) was dissolved in methanol (200 mL) at room temperature. Compound 2,6-diisopropylaniline (42 mL, 0.21 mol) and formic acid (0.2 mL, 0.005 mol) were added. The mixture was heated to 80 °C and stirred under reflux for 4 h. 2,6-diisopropylaniline and methanol were removed by vacuum distillation. The mixture was then precipitated with ethanol, washed, and recrystallized from dichloromethane / petroleum ether to obtain compound III-1 shown in formula (III) with a yield of 52.2%. 1 H NMR (400MHz, CDCl3): δ1.15(t,24H),2.34(s,6H),2.80(t,4H),7.08-7.10(m,2H),7.1 2-7.18(m,4H),7.62(t,1H),7.90-7.94(m,4H),7.98(d,2H),8.18(d,2H),9.00(s,1H);

[0241] Compound II-1, represented by formula (II), can be prepared in the following two ways:

[0242] Under anaerobic conditions, compound III-1 (3.2 g, 5 mmol) of formula (III) was dissolved in tetrahydrofuran (500 mL) at room temperature. The solution was cooled to -78 °C, and 1 M trimethylaluminum (25 mL, 25 mmol) was added dropwise. After the addition was complete, the solution was heated to room temperature and stirred for 3 h. The reaction was then terminated by adding an aqueous solution of ammonium chloride. The organic phase was extracted with ethyl acetate, and the organic phase was separated by silica gel gel chromatography to obtain compound II-1 of formula (II) in a yield of 64.2%. LCMS: [M+H] + =667.4; 1 H NMR (600MHz, CDCl3) δ8.76 (s, 1H), 8.20 (dd, 2H), 7.76-7.71 (m, 4H), 7.59 (t, J = 6.6Hz, 1H), 7.5 0(dd,2H),7.07(s,6H),4.53(s,2H),3.36-3.33(m,4H),1.52(s,12H),1.08(d,J=6.0Hz,24H);

[0243] Under anaerobic conditions, compound III-1 (3.2 g, 5 mmol) of formula (III) was dissolved in diethyl ether (500 mL) at room temperature. The solution was cooled to -78 °C, and 1.6 M lithium methyl (10 mL, 16 mmol) was added dropwise. After the addition was complete, the solution was heated to room temperature and stirred for 3 h. The reaction was then terminated by adding an aqueous solution of ammonium chloride. The organic phase was extracted with ethyl acetate, and the organic phase was separated by silica gel gel chromatography to obtain compound II-1 of formula (II) in a yield of 32.1%. LCMS: [M+H] + =667.4;

[0244] In a glove box, 2.67 g of compound II-1 (4.13 mmol) of formula (II) was dissolved in 20 mL of dry toluene. 3.4 mL of a hexane solution of n-butyllithium (8.5 mmol) was slowly added dropwise. The reaction was carried out at 20 °C for 1.5 h. Then, 2.7 g (8.5 mmol) of hafnium tetrachloride was added, and the mixture was heated to 120 °C and refluxed for 2 h. 9.4 mL (28.2 mmol) of methyl magnesium bromide was added, and the mixture was stirred at 25 °C for 12 h. The toluene was dried under vacuum, and 15 mL of dry n-hexane was added. After stirring for 15 min, the mixture was allowed to stand, filtered, and washed with dry n-hexane. The filtrate was dried under vacuum, and another 15 mL of dry toluene was added. The filtrate was collected by filtration, and the solvent was removed under vacuum to obtain a yellow solid, complex 8, with a yield of 60.1%. Elemental analysis showed that C... 50 H 66 Hf2N4: Theoretical values: C, 55.60; H, 6.16; N, 5.19; Test values: C, 55.41; H, 6.32; N, 5.22.

[0245] A 1L stainless steel polymerization reactor equipped with a mechanical stirrer was continuously dried at 130℃ for 3 hours. While still hot, a vacuum was drawn and the reactor was purged with N2 gas three times. 500mL of dried hexane was injected into the polymerization reactor, followed by 1.0mL of triisobutylaluminum (1mol / L hexane solution), 3.2mg of N,N-dimethylaniline tetra(pentafluorophenyl)borate (4μmol), and 2.2mg (2μmol) of complex 8. The reaction was carried out at 60℃ with an ethylene pressure of 10atm and stirred vigorously for 30min. Then, the ethylene was vented, and the reaction solution was neutralized with 10wt% hydrochloric acid-acidified ethanol solution. The precipitated solid was collected, dried to constant weight in a vacuum drying oven at 60℃, weighed, and the sample was analyzed. The number-average molecular weight, molecular weight distribution, and polymerization activity of the obtained polymer are shown in Table 1.

[0246] Example 2

[0247] A 1L stainless steel polymerization reactor equipped with a mechanical stirrer was continuously dried at 130℃ for 3 hours. While still hot, a vacuum was drawn and the reactor was purged with N2 gas three times. 500mL of dried hexane was injected into the polymerization reactor, followed by 20mL of 1-octene, 1.0mL of triisobutylaluminum (1mol / L hexane solution), 3.2mg of N,N-dimethylaniline tetra(pentafluorophenyl)borate (4μmol), and 2.2mg (2μmol) of complex 8. The reaction was carried out at 60℃ with an ethylene pressure of 10atm and stirred vigorously for 30min. Then, the ethylene was vented, and the reaction solution was neutralized with 10wt% hydrochloric acid-acidified ethanol solution. The precipitated solid was collected, dried to constant weight in a vacuum drying oven at 60℃, weighed, and the sample was analyzed. The number-average molecular weight, molecular weight distribution, and polymerization activity of the obtained polymer are shown in Table 1.

[0248] Example 3

[0249] A 1L stainless steel polymerization reactor equipped with a mechanical stirrer was continuously dried at 130℃ for 3 hours. While still hot, a vacuum was drawn and the reactor was purged with N2 gas three times. 500mL of dried decane was injected into the polymerization reactor, followed by 1.0mL of triisobutylaluminum (1mol / L toluene solution), 3.2mg of N,N-dimethylaniline tetra(pentafluorophenyl)borate (4μmol), and 2.2mg (2μmol) of complex 8. The reaction was carried out at 100℃ with an ethylene pressure of 10atm and stirred vigorously for 30min. Then, the ethylene was vented, and the reaction solution was neutralized with 10wt% hydrochloric acid-acidified ethanol solution. The precipitated solid was collected, dried to constant weight in a vacuum drying oven at 60℃, weighed, and the sample was analyzed. The number-average molecular weight, molecular weight distribution, and polymerization activity of the obtained polymer are shown in Table 1.

[0250] Example 4

[0251] A 1L stainless steel polymerization reactor equipped with a mechanical stirrer was continuously dried at 130℃ for 3 hours. While still hot, a vacuum was drawn and the reactor was purged with N2 gas three times. 400mL of dried decane was injected into the polymerization reactor, followed by 100mL of 1-octene, 1.0mL of triisobutylaluminum (1mol / L toluene solution), 3.7mg of triphenyl methyl tetrakis(pentafluorophenyl)borate (4μmol), and 2.2mg (2μmol) of complex 8. The reaction was carried out at 100℃ with an ethylene pressure of 10 atm and the mixture was stirred vigorously for 30 minutes. The ethylene was then vented, and the reaction solution was neutralized with 10wt% hydrochloric acid-acidified ethanol solution. The precipitated solid was collected, dried to constant weight in a vacuum drying oven at 60℃, weighed, and the sample was analyzed. The number-average molecular weight, molecular weight distribution, and polymerization activity of the obtained polymer are shown in Table 1.

[0252] Example 5

[0253] A 1L stainless steel polymerization reactor equipped with a mechanical stirrer was continuously dried at 130℃ for 3 hours. While still hot, a vacuum was drawn and the reactor was purged with N2 gas three times. 300mL of dried decane was injected into the polymerization reactor, followed by 100mL of 1-octene, 1.0mL of triisobutylaluminum (1mol / L toluene solution), 3.7mg of triphenyl methyl tetrakis(pentafluorophenyl)borate (4μmol), and 2.2mg (2μmol) of complex 8. The reaction was carried out at 140℃ with an ethylene pressure of 10atm and the mixture was stirred vigorously for 30min. The ethylene was then vented, and the reaction solution was neutralized with 10wt% hydrochloric acid-acidified ethanol solution. The precipitated solid was collected, dried to constant weight in a vacuum drying oven at 60℃, weighed, and the sample was analyzed. The number-average molecular weight, molecular weight distribution, and polymerization activity of the obtained polymer are shown in Table 1.

[0254] Example 6

[0255] The 50 mL Schlenk reaction tube was vacuum dried for 2 h and purged with N2 gas 3 times. 5 mL of dried toluene solution was added, along with 5 mL of 1-octene, 1.0 mL of triisobutylaluminum (1 mol / L toluene solution), 3.7 mg of triphenyl methyl tetrakis(pentafluorophenyl)borate (4 μmol), and 2.2 mg (2 μmol) of complex 8. The reaction was stirred vigorously at 40 °C for 60 min. The reaction solution was neutralized with ethanol solution acidified with 10 wt% hydrochloric acid. The precipitated solid was collected, dried to constant weight in a vacuum drying oven at 60 °C, weighed, and the sample was analyzed. The results are shown in Table 1.

[0256] Example 7

[0257] Complex 1: The complex shown in formula (I), wherein R1 and R2 are methyl, R3 and R7 are isopropyl, R4 to R6 are H, M is Hf, X is Cl, and n is 2;

[0258] In a glove box, 0.667 g of compound II-1 (1.00 mmol) of formula (II) was dissolved in 20 mL of dry toluene. 0.8 mL of a hexane solution of n-butyllithium (2.0 mmol) was slowly added dropwise. The reaction was carried out at 20 °C for 1.5 h. Then, 0.64 g (2.0 mmol) of hafnium tetrachloride was added, and the mixture was heated to 120 °C and refluxed for 2 h. The mixture was filtered, the toluene was dried, and the solution was washed with dry n-hexane to obtain a yellow solid, which was complex 1, with a yield of 63.2%. Elemental analysis showed that C... 46 H 54 Cl4Hf2N4; Theoretical calculated values: C, 47.56; H, 4.69; N, 4.82; Tested values: C, 47.41; H, 4.72; N, 5.02;

[0259] A 1L stainless steel polymerization reactor equipped with a mechanical stirrer was continuously dried at 130℃ for 3 hours. While still hot, a vacuum was drawn and the reactor was purged with N2 gas three times. 500mL of dried decane was injected into the polymerization reactor, followed by 1.0mL of triisobutylaluminum (1mol / L toluene solution), 3.2mg of N,N-dimethylaniline tetra(pentafluorophenyl)borate (4μmol), and 2.3mg (2μmol) of complex 1. The reaction was carried out at 100℃ with an ethylene pressure of 10atm and the mixture was stirred vigorously for 30min. The ethylene was then vented, and the reaction solution was neutralized with 10wt% hydrochloric acid-acidified ethanol solution. The precipitated solid was collected, dried to constant weight in a vacuum drying oven at 60℃, weighed, and the sample was analyzed. The number-average molecular weight, molecular weight distribution, and polymerization activity of the obtained polymer are shown in Table 1.

[0260] Example 8

[0261] A 1L stainless steel polymerization reactor equipped with a mechanical stirrer was continuously dried at 130℃ for 3 hours. While still hot, a vacuum was drawn and the reactor was purged with N2 gas three times. 500mL of dried decane was injected into the polymerization reactor, followed by 20mL of 1-octene, 1.0mL of triisobutylaluminum (1mol / L hexane solution), 3.2mg of N,N-dimethylaniline tetra(pentafluorophenyl)borate (4μmol), and 2.3mg (2μmol) of complex 1. The reaction was carried out at 100℃ with an ethylene pressure of 10atm and stirred vigorously for 30min. Then, the ethylene was vented, and the reaction solution was neutralized with 10wt% hydrochloric acid-acidified ethanol solution. The precipitated solid was collected, dried to constant weight in a vacuum drying oven at 60℃, weighed, and the sample was analyzed. The number-average molecular weight, molecular weight distribution, and polymerization activity of the obtained polymer are shown in Table 1.

[0262] Example 9

[0263] Complex 11: The complex shown in formula (I), wherein R1 and R2 are methyl, R3, R5 and R7 are methyl, R4 and R6 are H, M is Hf, X is methyl, and n is 2;

[0264] Under a nitrogen atmosphere, the compound shown in formula (V) (synthetic reference J. Am. Chem. Soc. 2020, 142, 12, 5819-5824) (9.5 g, 0.030 mol) was dissolved in methanol (200 mL) at room temperature. Compound 2,4,6-trimethylaniline (28.5 mL, 0.20 mol) and formic acid (0.2 mL, 0.005 mol) were added. The mixture was heated to 80 °C and refluxed with stirring for 4 h. 2,4,6-trimethylaniline and methanol were removed by vacuum distillation. The mixture was then precipitated with ethanol, washed, and recrystallized from dichloromethane / petroleum ether to obtain compound III-2 shown in formula (III), with a yield of 63.8%; LCMS: [M+H] + =552.5;

[0265] Under anaerobic conditions, compound III-2 (2.75 g, 5 mmol) of formula (III) was dissolved in tetrahydrofuran (500 mL) at room temperature. The solution was cooled to -78 °C, and 1 M trimethylaluminum (25 mL, 25 mmol) was added dropwise. After the addition was complete, the solution was heated to room temperature and stirred for 3 h. The reaction was then terminated by adding an aqueous solution of ammonium chloride. The organic phase was extracted with ethyl acetate, and the organic phase was separated by silica gel gel chromatography to obtain compound II-2 of formula (II) in a yield of 66.3%. LCMS: [M+H] + =583.2;

[0266] In a glove box, 2.33 g of compound II-2 (4.0 mmol) of formula (II) was dissolved in 20 mL of dry toluene. 3.2 mL of a hexane solution of n-butyllithium (8.0 mmol) was slowly added dropwise. The reaction was carried out at 20 °C for 1.5 h. Then, 2.55 g (8.0 mmol) of hafnium tetrachloride was added, and the mixture was heated to 120 °C and refluxed for 2 h. 9.4 mL (28.2 mmol) of methyl magnesium bromide was added, and the mixture was stirred at 25 °C for 12 h. The toluene was dried under vacuum, and 15 mL of dry n-hexane was added. After stirring for 15 min, the mixture was allowed to stand, filtered, and washed with dry n-hexane. The filtrate was dried under vacuum, and another 15 mL of dry toluene was added. The filtrate was collected by filtration, and the solvent was removed under vacuum to obtain a yellow solid, namely complex 11, with a yield of 62.5%. Elemental analysis: C 44 H 54 Hf2N4; Theoretical values: C, 53.06; H, 5.47; N, 5.63; Test values: C, 53.21; H, 5.71; N, 5.72;

[0267] A 1L stainless steel polymerization reactor equipped with a mechanical stirrer was continuously dried at 130℃ for 3 hours. While still hot, a vacuum was drawn and the reactor was purged with N2 gas three times. 500mL of dried hexane was injected into the polymerization reactor, followed by 1.0mL of triisobutylaluminum (1mol / L hexane solution), 3.2mg of N,N-dimethylaniline tetra(pentafluorophenyl)borate (4μmol), and 2.0mg (2μmol) of complex 11. The reaction was carried out at 60℃ with an ethylene pressure of 10atm and the mixture was stirred vigorously for 30min. The ethylene was then vented, and the reaction solution was neutralized with 10wt% hydrochloric acid-acidified ethanol solution. The precipitated solid was collected, dried to constant weight in a vacuum drying oven at 60℃, weighed, and the sample was analyzed. The number-average molecular weight, molecular weight distribution, and polymerization activity of the obtained polymer are shown in Table 1.

[0268] Example 10

[0269] A 1L stainless steel polymerization reactor equipped with a mechanical stirrer was continuously dried at 130℃ for 3 hours. While still hot, a vacuum was drawn and the reactor was purged with N2 gas three times. 500mL of dried hexane was injected into the polymerization reactor, followed by 20mL of 1-octene, 1.0mL of triisobutylaluminum (1mol / L hexane solution), 3.2mg of N,N-dimethylaniline tetra(pentafluorophenyl)borate (4μmol), and 2.0mg (2μmol) of complex 11. The reaction was carried out at 60℃ with an ethylene pressure of 10atm and the mixture was stirred vigorously for 30min. The ethylene was then vented, and the reaction solution was neutralized with 10wt% hydrochloric acid-acidified ethanol solution. The precipitated solid was collected, dried to constant weight in a vacuum drying oven at 60℃, weighed, and the sample was analyzed. The number-average molecular weight, molecular weight distribution, and polymerization activity of the obtained polymer are shown in Table 1.

[0270] Example 11

[0271] Complex 50: The complex shown in formula (I), wherein R1 and R2 are methyl, R3 and R7 are isopropyl, R4 to R6 are H, M is Zr, X is methyl, and n is 2;

[0272] In a glove box, 2.00 g of compound II-1 (3 mmol) of formula (II) was dissolved in 10 mL of dry toluene. 2.6 mL of a hexane solution of n-butyllithium (6.5 mmol) was slowly added dropwise. The reaction was carried out at 20 °C for 1.5 h. Then, 1.40 g (6.0 mmol) of zirconium tetrachloride was added, and the mixture was heated to 120 °C and refluxed for 2 h. 6.0 mL (18 mmol) of methyl magnesium bromide was added, and the mixture was stirred at 25 °C for 12 h. The toluene was dried under vacuum, and 20 mL of dry n-hexane was added. After stirring for 15 min, the mixture was allowed to stand, filtered, and washed with dry n-hexane. The filtrate was dried under vacuum, and 30 mL of dry toluene was added. The filtrate was collected by filtration, and the solvent was removed under vacuum to obtain a brownish-green solid, namely complex 50, with a yield of 67.8%. Elemental analysis showed: C 50 H 66 N4Zr2; Theoretical values: C, 66.32; H, 7.35; N, 6.19; Test values: C, 66.21; H, 7.61; N, 6.22;

[0273] A 1L stainless steel polymerization reactor equipped with a mechanical stirrer was continuously dried at 130℃ for 3 hours. While still hot, a vacuum was drawn and the reactor was purged with N2 gas three times. 500mL of dried decane was injected into the polymerization reactor, followed by 20mL of 1-octene, 1.0mL of triisobutylaluminum (1mol / L toluene solution), 3.7mg of triphenyl methyl tetrakis(pentafluorophenyl)borate (4μmol), and 1.8mg of complex 50. The reaction was carried out at 60℃ with an ethylene pressure of 10atm and stirred vigorously for 30min. Then, the ethylene was vented, and the reaction solution was neutralized with 10wt% hydrochloric acid-acidified ethanol solution. The precipitated solid was collected, dried to constant weight in a vacuum drying oven at 60℃, weighed, and the sample was analyzed. The number-average molecular weight, molecular weight distribution, and polymerization activity of the obtained polymer are shown in Table 1.

[0274] Comparative Example 1

[0275] A 1L stainless steel polymerization reactor equipped with a mechanical stirrer was continuously dried at 130℃ for 3 hours. While still hot, a vacuum was drawn and the reactor was purged with N2 gas three times. 300mL of dried decane was injected into the polymerization reactor, followed by 100mL of 1-octene, 1.0mL of triisobutylaluminum (1mol / L toluene solution), 3.7mg of triphenylmethyl tetrakis(pentafluorophenyl)borate (4μmol), and 2.3mg (4μmol) of complex A (synthesis reference ACS Catal., 2017, 7, 6930). The reaction was carried out at 140℃ with an ethylene pressure of 10 atm and the mixture was stirred vigorously for 30 minutes. The ethylene was then vented, and the reaction solution was neutralized with 10wt% hydrochloric acid-acidified ethanol solution. The precipitated solid was collected, dried to constant weight in a vacuum drying oven at 60℃, weighed, and the sample was analyzed. The number-average molecular weight, molecular weight distribution, and polymerization activity of the obtained polymer are shown in Table 1.

[0276]

[0277] Comparative Example 2

[0278] The 50 mL Schlenk reaction tube was vacuum dried for 2 h and purged with N2 gas 3 times. 5 mL of dried toluene solution was added, along with 5 mL of 1-octene, 1.0 mL of triisobutylaluminum (1 mol / L toluene solution), 3.7 mg of triphenyl methyl tetrakis(pentafluorophenyl)borate (4 μmol), and 2.3 mg (4 μmol) of complex A. The reaction was stirred vigorously at 40 °C for 60 min. The reaction solution was neutralized with 10 wt% hydrochloric acid-acidified ethanol solution. The precipitated solid was collected, dried to constant weight in a vacuum drying oven at 60 °C, weighed, and the sample was analyzed. The results are shown in Table 1.

[0279] Table 1

[0280] serial number coordination compounds Polymerization activity (g / mol M.h) <![CDATA[M w ]]> <![CDATA[M w / M n ]]> Example 1 Complex 8 <![CDATA[13.71×10 6 ]]> <![CDATA[88.42×10 4 ]]> 4.73 Example 2 Complex 8 <![CDATA[14.12×10 6 ]]> <![CDATA[67.13×10 4 ]]> 5.16 Example 3 Complex 8 <![CDATA[4.32×10 6 ]]> <![CDATA[16.71×10 4 ]]> 4.53 Example 4 Complex 8 <![CDATA[5.07×10 6 ]]> <![CDATA[22.37×10 4 ]]> 6.51 Example 5 Complex 8 <![CDATA[4.24×10 6 ]]> <![CDATA[13.27×10 4 ]]> 9.82 Example 6 Complex 8 <![CDATA[1.32×10 6 ]]> <![CDATA[14.12×10 4 ]]> 5.62 Example 7 Complex 1 <![CDATA[3.27×10 6 ]]> <![CDATA[24.47×10 4 ]]> 4.16 Example 8 Complex 1 <![CDATA[4.51×10 6 ]]> <![CDATA[22.32×10 4 ]]> 5.16 Example 9 Complex 11 <![CDATA[10.14×10 6 ]]> <![CDATA[41.32×10 4 ]]> 4.63 Example 10 Complex 11 <![CDATA[13.15×10 6 ]]> <![CDATA[37.42×10 4 ]]> 4.47 Example 11 Complex 50 <![CDATA[3.12×10 6 ]]> <![CDATA[6.47×10 4 ]]> 10.31 Comparative Example 1 Complex A <![CDATA[0.73×10 6 ]]> <![CDATA[1.02×10 4 ]]> 2.52 Comparative Example 2 Complex A <![CDATA[0.11×10 6 ]]> <![CDATA[4.6×10 4 ]]> 2.2

[0281] As can be seen from the results in Table 1, when the group IVB organometallic complex described in this invention is applied to olefin polymerization, it exhibits higher polymerization activity under similar polymerization conditions. The molecular weight of the resulting polymer is significantly higher than that of the polymer obtained in the comparative example, and the molecular weight distribution of the resulting polymer is also wider.

[0282] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A Group IVB metal organic complex, characterized in that, The structure of the Group IVB metal organic complex is shown as formula (I): wherein R1and R2are each independently selected from substituted or unsubstituted C1-C30alkyl, C1-C30alkoxy, substituted or unsubstituted C3-C30cycloalkyl, C3-C30cycloalkoxy, substituted or unsubstituted C6-C30aryl, and C6-C40aryloxy; R3-R7are each independently selected from hydrogen, substituted or unsubstituted C1-C30alkyl, substituted or unsubstituted C1-C30cycloalkyl, substituted or unsubstituted C1-C30alkoxy, substituted or unsubstituted C1-C30dialkylamino, substituted or unsubstituted C3-C30cycloalkoxy, substituted or unsubstituted C3-C30dicycloalkylamino, substituted or unsubstituted C6-C40aryl, substituted or unsubstituted C7-C40aryloxy, substituted or unsubstituted C6-C40arylamino, and substituted or unsubstituted C3-C40trihydrocarbylsilyl, or any two or more of R3-R7are connected to form a ring structure; X is selected from a divalent substituent having 1-40 atoms, halogen, or C1-C20hydrocarbyl; n is 1 or 2; M is selected from a Group IVB metal.

2. The Group IVB metal organic complex of claim 1, wherein, R1and R2are each independently selected from C1-C20alkyl, C1-C20alkoxy, C3-C20cycloalkyl, C3-C20cycloalkoxy, substituted or unsubstituted C6-C30aryl, and C6-C30aryloxy; Preferably, R3-R7are each independently selected from hydrogen, substituted or unsubstituted C1-C20alkyl, C1-C20alkoxy, C1-C20dialkylamino, substituted or unsubstituted C3-C20cycloalkyl, C3-C20cycloalkoxy, C3-C20dicycloalkylamino, substituted or unsubstituted C6-C30aryl, C7-C30aryloxy, C6-C30arylamino, and C3-C30trihydrocarbylsilyl, or any two or more of R3-R7are connected to form a ring structure; Preferably, when n is 1, X is a divalent substituent having 1-40 atoms, and when n is 2, X is halogen or C1-C20hydrocarbyl; Preferably, M is selected from titanium, zirconium, or hafnium.

3. The Group IVB metal organic complex of claim 1 or 2, wherein, R1and R2are each independently selected from C1-C20alkyl, C1-C20alkoxy, C3-C20cycloalkoxy, substituted or unsubstituted C6-C30aryl, and C6-C30aryloxy; Preferably, R1and R2are each independently selected from C1-C6alkyl, phenyl, substituted C7-C20phenyl, naphthyl, substituted C7-C20naphthyl, anthryl, indenyl, fluorenyl, phenoxy, substituted C7-C20phenoxy, or substituted C7-C20naphthoxy; Preferably, R3-R7are each independently selected from hydrogen, substituted or unsubstituted C1-C20alkyl, substituted or unsubstituted C3-C20cycloalkyl, and substituted or unsubstituted C6-C30aryl, or any two or more of R3-R7are connected to form a ring structure; Preferably, when n is 1, X is selected from alkylene having 1-20 atoms, arylene having 1-20 atoms, diaminylene having 1-20 atoms or diene having 1-20 atoms; when n is 2, X is selected from halogen, substituted or unsubstituted C1-C10 alkyl and substituted or unsubstituted C1-C10 aryl; Preferably, M is selected from titanium, zirconium or hafnium.

4. A process for producing the Group IVB metal organic complex according to any one of claims 1 to 3, characterized in that The method comprises: in the presence of an organic solvent, a compound represented by formula (II) is subjected to a first reaction with a hydrogen abstractor, then a second reaction with a M salt, and finally a reaction with an optional Grignard reagent; wherein the M salt is a halide of a Group IVB metal or a hydrocarbyl compound of a Group IVB metal; R1-R7 are defined as in claim 1.

5. The method of claim 4, wherein, The conditions of the first reaction include a temperature of -78-35℃ and a time of 1-24h. Preferably, the molar ratio of the compound represented by formula (II) to the hydrogen abstractor is 1:2-5, preferably 1:2-4.

6. Preferably, the hydrogen abstractor is selected from one or more of sodium hydride, potassium hydride, lithium hydride, tetramethylethylenediamine, lithium bis(trimethylsilyl)amide, sodium bis(trimethylsilyl)amide, lithium diisopropylamide and C1-C6 alkyl lithium.

6. The method according to claim 4 or 5, characterized in that, The conditions of the second reaction include a temperature of 60-120℃ and a time of 1-30h. Preferably, the molar ratio of the compound represented by formula (II) to the metal M in the M salt is 1:2-3, preferably 1:2-2.

6. Preferably, the organic solvent is selected from one or more of tetrahydrofuran, diethyl ether, pentane, cyclopentane, n-hexane, cyclohexane, heptane, methylcyclohexane, toluene, xylene, chlorobenzene and o-dichlorobenzene.

7. The method according to claim 5 or 6, characterized in that, The method for preparing the compound represented by formula (II) comprises the following steps: (1) in the presence of a first solvent and formic acid and / or acetic acid, a third reaction of a compound represented by formula (V) and a compound represented by formula (IV) to obtain a compound represented by formula (III); (2) in the presence of a second solvent, a fourth reaction of the compound represented by formula (III) and a compound A; wherein the compound A is LiR1 or Al(R1)3; R1-R7 are defined as in claim 1.

8. The method of claim 7, wherein, In step (1), the conditions of the third reaction include a temperature of 50-120℃ and a time of 4-24h. Preferably, in step (1), the molar ratio of the use amount of the compound represented by formula (V) to the compound represented by formula (IV) is 1:2-8. Preferably, in step (1), the first solvent is selected from one or more of methanol, ethanol, toluene, xylene, benzene, diethyl ether and tetrahydrofuran.

9. The method according to claim 7 or 8, characterized in that, In step (2), the conditions of the fourth reaction include a temperature of -78-120℃ and a time of 0.5-24h. Preferably, in step (2), the molar ratio of the use amount of the compound represented by formula (III) to the compound A is 1:2-10. Preferably, in step (2), the second solvent is selected from one or more of methanol, ethanol, toluene, xylene, benzene, diethyl ether and tetrahydrofuran.

10. Use of the Group IVB metal organic complex according to any one of claims 1 to 3 in the polymerization of olefins.

11. A catalyst for the polymerization of olefins, characterized in that, The catalyst for the polymerization of olefins comprises a main catalyst and a cocatalyst, the main catalyst being the Group IVB metal organic complex according to any one of claims 1 to 3; The cocatalyst is selected from one or more of aluminoxane, alkylaluminum compound, chlorinated alkylaluminum, alkylzinc and optionally an organic boron compound.

12. The catalyst according to claim 11, characterized in that, The aluminoxane is methylaluminoxane and / or modified methylaluminoxane; Preferably, the alkylaluminum compound is selected from one or more of triethylaluminum, triisobutylaluminum and trioctylaluminum; Preferably, the chlorinated alkylaluminum is selected from one or more of monochloroethylaluminum, sesquiethylaluminum chloride and dichloroethylaluminum; Preferably, the organic boron compound is selected from one or more of triphenylmethyl tetra(pentafluorophenyl) borate, triphenylmethyl tetra(pentafluorophenyl) borate, tris(pentafluorophenyl) boron, N,N-dimethylanilinium tetra(pentafluorophenyl) borate, dioctadecylmethyl tertiary amine tetra(pentafluorophenyl) borate and dihydrogenated tallowmethyl tertiary amine tetra(pentafluorophenyl) borate.

13. The catalyst for the polymerization of olefins according to claim 11 or 12, characterized by the fact that, The molar ratio of the metal aluminum in the cocatalyst to the metal M in the main catalyst is 1 to 10000:1; the molar ratio of the element boron in the cocatalyst to the metal M in the main catalyst is 0 to 10:

1.

14. A process for the polymerization of olefins characterized in that, The polymerization of olefins is carried out in the presence of the catalyst for the polymerization of olefins according to any one of claims 11 to 13; Preferably, the temperature of the polymerization reaction is -78°C to 250°C, more preferably -20°C to 200°C; the polymerization pressure is 0.1 to 100 atm, more preferably 0.1 to 50 atm.

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