CN114149471A

CN114149471A - Transition metal complex and preparation method and application thereof

Info

Publication number: CN114149471A
Application number: CN202010933290.0A
Authority: CN
Inventors: 孙文华; 张秋月; 马艳平
Original assignee: Institute of Chemistry CAS
Current assignee: Institute of Chemistry CAS
Priority date: 2020-09-08
Filing date: 2020-09-08
Publication date: 2022-03-08

Abstract

The invention discloses a transition metal complex and a preparation method and application thereof. The structural formula of the compound is shown as the following formula (I):

in the formula (I), M is selected from iron or cobalt; r¹、R²Are all selected from H, F, Cl, Br, I, unsubstituted C_1‑6Alkyl or C_1‑6Alkoxy, by one or more R^aSubstituted C_1‑6Alkyl or C_1‑6At least one of alkoxy, and each R¹、R²Are the same or different; r³、R⁴、R⁵Are all selected from H, F, Cl, Br, I, by one or more R^bSubstituted of the following groups: c_1‑6Alkyl radical, C_1‑6Alkoxy radical, C_3‑10Cycloalkyl radical, C_3‑10Cycloalkyloxy, aryl, aryloxy or C_1‑6Alkylene aryl, and each R³、R⁴、R⁵Are the same or different; x is selected from F, Cl, Br and I, and two X are the same or different. The preparation method comprises the following steps: a compound represented by the formula (II) and a compound MX₂Or a hydrate thereof is subjected to a complex reaction to obtain a complex shown in the formula (I);

Description

Transition metal complex and preparation method and application thereof

Technical Field

The invention relates to a transition metal complex and a preparation method and application thereof, belonging to the technical field of polyolefin catalysts.

Background

The polyethylene wax (PEW) is low-molar-mass polyethylene with the molar mass of 500-5000 g/mol, the melting point of more than 90 ℃ and the relative density of 0.92-0.936 g/cm³In the meantime. The rubber has the advantages of low toxicity, no corrosion, high hardness, high softening point, low melt viscosity, wear resistance, heat resistance, good lubricity, dispersibility, fluidity and the like, can be used as a lubricant, a low-viscosity dispersant and the like to be widely applied to various fields, can also effectively improve the processing efficiency of pipes, films, cables and other plastic rubbers, and has wide development and utilization prospects. At present, the polyethylene wax is mainly prepared by a polyethylene cracking method, a byproduct refining method and an ethylene synthesis method. The polyethylene wax prepared by the synthesis method is directly synthesized by taking ethylene as a raw material, and the polyethylene synthesized by the method has high purity, small relative molecular mass distribution, adjustable product chain length and crystallization degree and stable quality, and can be used for producing high-quality and diversified polyethylene wax.

Polyethylene wax is produced in 1939 by adopting a high-pressure polymerization technology; after 1953, the product can be prepared by low-pressure Ziegler method; since the beginning of the 90 s in the 20 th century, the catalyst is produced by adopting a method of initiating synthesis by using a metallocene catalyst of the latest generation. This also illustrates the design and development of olefin polymerization catalysts, which are key to the further development of polyethylene wax products.

At present, the majority of polyethylene wax catalysts used are Ziegler-Natta catalysts and metallocene catalysts. The inventor subjects to research and discover that the metal complex taking transition metals of iron, cobalt and chromium as centers can catalyze ethylene polymerization (shown as A-F in formula 1) with high activity to obtain ethylene oligomerization products with low molecular weight or narrow distributionThe highly linear polyolefin wax of (4). Wherein the chromium (II) complex of the heterocyclic pyridine with the unilateral hexatomic (2, 8-diarylimine-5, 6, 7-trihydroquinoline) or heptatomic heterocyclic structure (2, 9-diarylimine-5, 6,7, 8-tetrahydrocycloheptene pyridine) (formula 1, B, Eur.J.Inorg.Chem.,2017, 4158-4166; Dalton Trans.,2018,47, 13487-13497) and the bilateral heptatomic heterocyclic structure (alpha, alpha' -diarylimine-2, 3:5, 6-bis (pentamethylene) pyridine) (formula 1, C, Dalton Trans.,2017,46, 6948-6957) can catalyze ethylene polymerization at 70 ℃ or 80 ℃ to obtain low molecular weight (2 kg mol) under the condition of MAO or MMAO as cocatalyst^-1) The activity of the narrow-distribution unsaturated linear polyethylene can almost reach 10⁷g·mol^-1(Cr)·h^-1. In addition to the chromium catalyst, iron cobalt complexes based on diaryliminepyridine skeletons containing flexible seven-membered rings also exhibit the ability to catalyze the polymerization of ethylene to polyethylene wax after the introduction of benzhydryl or difluorobenzyl groups. D (Organometallics,2019,38, 4455-4470) showed up to 3.93X 10 when MAO or MMAO was used as cocatalyst⁷g·mol^-1(Fe)·h^-1To a highly linear, low molecular weight (0.85-5.06 kg mol)^-1) And narrow dispersibility (M)_w/M_nThe range is as follows: 1.1-2.7) Polyethylene (PEs). However, neither the catalytic activity nor the thermal stability of the cobalt complexes is comparable to that of iron and chromium complexes in ethylene catalytic processes, e.g. E in formula 1 (Dalton transformations, 2020,49,9425) having an optimum experimental temperature of 60 ℃ and an optimum activity of 7.47X 10⁶g·mol^-1(Co)·h^-1Ultimately resulting in a high degree of linearity (T)_m>121 ℃) with narrow dispersibility (M)_w/M_nThe range is as follows: 1.7-2.9) low molecular weight polyethylene waxes (molecular weight range: 1.47-5.00 kg mol^–1)。

The late transition metal complex olefin polymerization catalyst as a novel ethylene polymerization catalyst system still has some difficulties of basic research and restriction factors for promoting industrialization. For example, the late transition metal cobalt complex has poor thermal stability during the reaction, thereby easily causing the activity of the catalyst to decrease as the reaction temperature increases. Secondly, the catalytic activity of the cobalt catalyst is far inferior to that of the iron homologues, and further improvement of the activity of the cobalt catalyst through improvement of the framework structure is also a great challenge in the development of the cobalt catalyst. Therefore, in addition to the improvement of the catalytic performance of the catalyst and the improvement of the preparation conditions and efficiency, obtaining a catalyst with higher activity and high thermal stability is one of the important matters of research, and is the key to advance the chemical industrialization as soon as possible.

Disclosure of Invention

The invention aims to provide a transition metal complex and a preparation method and application thereof.

The invention provides a transition metal complex, which has a structural formula shown as the following formula (I):

in the formula (I), M is selected from iron or cobalt;

R¹、R²are all selected from H, F, Cl, Br, I, unsubstituted C_1-6Alkyl or C_1-6Alkoxy, by one or more R^aSubstituted C_1-6Alkyl or C_1-6At least one of alkoxy, and each R¹、R²Are the same or different;

R³、R⁴、R⁵are all selected from H, F, Cl, Br, I, by one or more R^bSubstituted of the following groups: c_1-6Alkyl radical, C_1-6Alkoxy radical, C_3-10Cycloalkyl radical, C_3-10Cycloalkyloxy, aryl, aryloxy or C_1-6Alkylene aryl, and each R³、R⁴、R⁵Are the same or different;

x is selected from F, Cl, Br and I, and two X are the same or different;

R^aselected from H, F, Cl, Br, I, unsubstituted or arbitraryIs selected by one or more R^cSubstituted C_1-6Alkyl radical, C_1-6Alkoxy radical, C_3-10Cycloalkyl radical, C_3-10Cycloalkyloxy, aryl or aryloxy, and each R^aThe same or different;

R^bselected from H, F, Cl, Br, I, unsubstituted or optionally substituted by one or more R^cSubstituted C_1-6Alkyl radical, C_1-6Alkoxy radical, C_3-10Cycloalkyl radical, C_3-10Cycloalkyloxy, aryl or aryloxy, and each R^bThe same or different;

R^cselected from H, F, Cl, Br, I, C_1-6Alkyl radical, C_1-6Alkoxy radical, C_3-10Cycloalkyl radical, C_3-10Cycloalkyloxy, aryl or aryloxy, and each R^cThe same or different.

In the above transition metal complex, in the formula (I), R¹、R²Are all selected from H, C_1-3Alkyl, and each R¹、R²Are the same or different; specifically, the compound can be selected from H, methyl, ethyl, n-propyl and isopropyl;

R³、R⁴、R⁵are all selected from H, F, Cl, Br, I or C_1-3Alkyl, and each R³、R⁴、R⁵The same or different;

R^a、R^b、R^care all selected from H, C_1-3Alkyl or C_1-3Alkoxy, and each R^a、R^b、R^cThe same or different;

x is selected from Cl or Br, and two X are the same or different.

In a specific embodiment of the present invention, the substituent of the complex represented by the formula (I) is a complex having the following substituent:

complex Co-1: wherein R is¹Me, X is selected from Cl, the other groups are H;

complex Co-2: wherein R is¹Et, X is selected from Cl, the other groups are H;

complex Co-3: wherein R is¹i-Pr, X being selected from Cl, other radicalsThe cluster is H;

complex Co-4: wherein R is¹＝Me，R²Me, X is selected from Cl, the other groups are H;

complex Co-5: wherein R is¹＝Et，R²Me, X is selected from Cl and the other groups are H.

The invention also provides a compound, the structural formula of which is shown as the following formula (II):

in the formula (II), R¹、R²、R³、R⁴、R⁵The same as in the transition metal complex represented by the above formula (I).

In a specific embodiment of the invention, the group in the compound of formula (II) has a ligand compound defined by:

ligand L1: r¹Me, other groups are H;

ligand L2: r¹Et, other groups are H;

ligand L3: r¹i-Pr, other groups are H;

ligand L4: r¹＝Me，R²Me, other groups are H;

ligand L5: r¹＝Et，R²Me, the other groups are H.

The invention also provides a preparation method of the compound shown in the formula (II), which comprises the following steps:

carrying out condensation reaction on a compound shown in a formula (III) and a compound shown in a formula (IV) to obtain a ligand compound shown in a formula (II);

in the formulae (III) and (IV), R¹、R²、R³、R⁴、R⁵And the transition metal represented by the above formula (I)Same in the complex.

In the preparation method, the condensation reaction is carried out under the catalysis of p-toluenesulfonic acid, and the solvent can be at least one of toluene, o-xylene and o-dichlorobenzene, preferably toluene; the heating reflux time can be 7-10 h, and the preferable time can be 10 h;

the molar ratio of the compound shown in the formula (III) to the compound shown in the formula (IV) is 1: 1-1.5, and the preferred molar ratio is 1: 1.2.

The compound shown in the formula (II) is applied to the preparation of the transition metal complex shown in the formula (I).

The invention also provides a preparation method of the transition metal complex shown in the formula (I), which comprises the following steps: reacting a compound represented by the formula (II) with a compound MX₂Or a hydrate thereof is subjected to a complex reaction to obtain a complex shown in the formula (I);

wherein M, X is the same as in the transition metal complex represented by the above formula (I).

Further, the complexation reaction is performed under oxygen-free conditions; for example under the protection of an inert gas such as nitrogen;

said compound MX₂The molar ratio of the compound represented by the formula (II) to the compound represented by the formula (II) may be 1:1 to 1.5, preferably 1:1 to 1.3, and more preferably 1: 1.1.

The transition metal complex shown in the formula (I) is applied to catalyzing olefin polymerization reaction.

In the present invention, the transition metal complex represented by the above formula (I) is particularly applicable to catalyzing ethylene polymerization.

The invention also provides a catalyst composition, which consists of a main catalyst and a cocatalyst;

wherein the main catalyst is the transition metal complex shown in the formula (I);

the cocatalyst is selected from at least one of aluminoxane, alkyl aluminum and alkyl aluminum chloride.

In the invention, the molar ratio of the central metal M of the main catalyst to the metal Al in the cocatalyst can be specifically 500-4000: 1.

In the present invention, the aluminoxane is specifically selected from Methylaluminoxane (MAO) and/or triisobutylaluminum-Modified Methylaluminoxane (MMAO);

the alkyl in the alkyl aluminum and the alkyl chloride is specifically selected from alkyl with 1-3 carbon atoms.

In the invention, the molar ratio of the metal Al in the cocatalyst to the central metal (specifically Co) of the complex shown in the formula (I) is (500-4000): 1, preferably (1000-3000): 1, specifically 1000:1, 1500:1, 1750:1, 2000:1, 2250:1, 2500:1 and 3000: 1;

preferably, when the cocatalyst is Methylaluminoxane (MAO), the molar ratio of the metal Al in the Methylaluminoxane (MAO) to the central metal (specifically, Co) of the complex represented by formula (I) may be (1000-3000): 1, and more preferably, the molar ratio is 2000: 1;

preferably, when the cocatalyst is triisobutylaluminum-Modified Methylaluminoxane (MMAO), the molar ratio of metal Al in the triisobutylaluminum-Modified Methylaluminoxane (MMAO) to the central metal (specifically Co) of the complex shown in formula (I) is (1000-3000): 1, and more preferably is 2500: 1.

The invention further provides a preparation method of the olefin polymer, which comprises the following steps: catalyzing olefin to carry out polymerization reaction under the action of the transition metal complex shown in the formula (I) or the catalyst composition to obtain the olefin polymer.

In the invention, the temperature of the polymerization reaction is specifically 30-100 ℃, and specifically can be 40 ℃, 50 ℃, 60 ℃, 70 ℃, 80 ℃, 90 ℃ or 40-90 ℃;

the polymerization reaction time is specifically 5-60 min, specifically 5min, 15min, 45min and 60 min;

the pressure of the polymerization reaction is specifically 0.5-10 atm, and specifically can be 1atm, 5atm or 10 atm.

In the present invention, the olefin may specifically be ethylene, i.e. the polymerization reaction is carried out under an ethylene atmosphere.

In the present invention, the term "C_1-6Alkyl "means a straight or branched alkyl group having 1 to 6 carbon atoms, such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, sec-butyl, pentyl, neopentyl.

The term "C_1-6Alkoxy "is to be understood as preferably meaning a straight-chain or branched, saturated monovalent hydrocarbon radical of the formula-O-alkyl, where the term" alkyl "has the above-mentioned definition and is, for example, methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, sec-butoxy, tert-butoxy, pentyloxy, isopentyloxy, hexyloxy or isomers thereof. In particular, "alkoxy" is "C_1-6Alkoxy group "," C_1-4Alkoxy group "," C_1-3Alkoxy ", methoxy, ethoxy or propoxy, preferably methoxy, ethoxy or propoxy. Further preferred is "C_1-2Alkoxy ", in particular methoxy or ethoxy.

The term "C_3-10Cycloalkyl "is to be understood as preferably meaning a straight-chain or branched, saturated, monovalent, monocyclic hydrocarbon ring which contains, for example, 3, 4, 5,6,7 or 8 carbon atoms. C_3-8Cycloalkyl is, for example, a monocyclic hydrocarbon ring, such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl or cycloheptyl. In particular, said cycloalkyl is C_4-6Cycloalkyl radical, C_5-6Cycloalkyl or cyclohexyl. For example, the term "C_3-6Cycloalkyl "is understood as preferably meaning a saturated monovalent monocyclic hydrocarbon ring which contains, for example, 3, 4, 5 or 6 carbon atoms. Specifically, C_3-6Cycloalkyl is a monocyclic hydrocarbon ring, such as cyclopropyl, cyclobutyl, cyclopentyl or cyclohexyl.

The term "C_3-10Cycloalkyloxy is to be understood as preferably meaning a radical of the formula-O-cycloalkyl in which the term "C" is intended_3-10Cycloalkyl "has the definition as described above.

The term "aryl" is understood to mean preferably a mono-, bi-or tricyclic hydrocarbon ring having a monovalent aromatic or partially aromatic character of 6 to 20 carbon atoms, preferably "C_6-14Aryl ". The term "C_6-14Aryl "is to be understood as preferably meaning having 6,7,8, 9,10. Monocyclic, bicyclic or tricyclic hydrocarbon ring of monovalent or partial aromaticity of 11, 12, 13 or 14 carbon atoms ("C)_6-14Aryl group "), in particular a ring having 6 carbon atoms (" C₆Aryl "), such as phenyl; or biphenyl, or is a ring having 9 carbon atoms ("C₉Aryl), such as indanyl or indenyl, or a ring having 10 carbon atoms ("C₁₀Aryl radicals), such as tetralinyl, dihydronaphthyl or naphthyl, or rings having 13 carbon atoms ("C₁₃Aryl radicals), such as the fluorenyl radical, or a ring having 14 carbon atoms ("C)₁₄Aryl), such as anthracenyl.

Examples of monocyclic rings of heteroaryl groups include, but are not limited to, thienyl, furyl, pyrrolyl, oxazolyl, thiazolyl, imidazolyl, pyrazolyl, isoxazolyl, isothiazolyl, oxadiazolyl, triazolyl, thiadiazolyl, thia-4H-pyrazolyl and the like and their benzo derivatives, such as benzofuranyl, benzothienyl, benzoxazolyl, benzisoxazolyl, benzimidazolyl, benzotriazolyl, indazolyl, indolyl, isoindolyl and the like; or pyridyl, pyridazinyl, pyrimidinyl, pyrazinyl, triazinyl, and the like, and benzo derivatives thereof, such as quinolyl, quinazolinyl, isoquinolyl, and the like; or azocinyl, indolizinyl, purinyl and the like and benzo derivatives thereof; or cinnolinyl, phthalazinyl, quinazolinyl, quinoxalinyl, naphthyridinyl, pteridinyl, carbazolyl, acridinyl, phenazinyl, phenothiazinyl, phenoxazinyl, and the like.

The term "aryloxy" is to be understood as preferably meaning a radical of the formula-O-aryl or-O-heteroaryl, where the term "aryl" has the abovementioned meaning.

The term "aryl C_1-6Alkylene "is understood as preferably meaning C_1-6One substituent of the alkylene group is a group of aryl group. Wherein, C_1-6Alkylene means C_1-6The alkyl group further has a substitution site, wherein the terms "aryl", "C" and "C" are used_1-6Alkyl "has the above definition.

The invention has the following advantages:

1. the invention provides a high-heat-stability fluorine-containing and fluorine-containing large-steric-hindrance benzhydryl-containing asymmetric pyridine diimine ligand compound for preparing polyethylene wax and a preparation method of a transition metal complex thereof. The preparation process of the compound has the advantages of mild reaction conditions, short period, simple operation conditions and the like.

2. The invention provides a high-heat-stability fluorine-containing and fluorine-containing large-steric-hindrance benzhydryl substituent asymmetric pyridine diimine ligand compound for preparing polyethylene wax and a transition metal complex thereof. The complex has an asymmetric structure, and a unilateral benzene ring has the characteristic of ortho-position isosubstituent, the structure contains electron-withdrawing substituent fluorine and a large steric hindrance substituent bis (4-fluorophenyl) methyl, the complex has a single catalytic activity center, the regulation and control of the molecular weight of a polymer can be realized by changing the structure of a ligand and the polymerization reaction conditions, and the complex has the advantages of outstanding thermal stability, high catalytic activity, low cost and the like. For example, the catalytic activity of MAO is 10.27-11.67X 10at 50-70 deg.C⁶g·mol^-1(Co)h^-1Small floating, high thermal stability, even at 90 deg.C, the catalytic activity can still be maintained at 2.83X 10⁶g·mol^-1(Co)h^-1The method meets the operation temperature of industrial production and has a wide application prospect.

3. The invention provides a high-heat-stability fluorine-containing and fluorine-containing large-steric-hindrance bis (4-fluorophenyl) methyl-containing asymmetric pyridine diimine ligand compound and application of a transition metal complex thereof. The asymmetric diimine-based metal cobalt complex prepared by an intermediate is used as a catalyst for ethylene polymerization reaction. The complex has the following structural characteristics: the aniline on two sides of the metal center has an asymmetric structure, and the unilateral aniline has a fluorine-containing substituent with large steric hindrance at 2,4 positions and a strong electron-withdrawing fluorine substituent at 6 positions. Under the synergistic effect of the structures, particularly the existence of a strong electron-withdrawing fluorine substituent, the stronger positive electricity characteristic of the central metal and stronger Lewis acidity are favorably stabilized, the probability of ethylene insertion is improved, and the high catalytic activity and stability of the system are ensured. For example, at 70 ℃, the activity of the cobalt complex for catalyzing ethylene polymerization can be up to 11.6710⁶g·mol^-1(Co)·h^-1. Polyethylene prepared by the catalyst has weight average molecular weight M_wSmall, mostly 0.8-2.2 kg/mol^-1The polyethylene wax has fluctuation, belongs to typical polyethylene wax, can be used for preparing special high-end commercial polyethylene wax products, and simultaneously shows extremely strong regulation and control performance on the molecular weight of polyethylene.

4. The invention provides a synthetic molecular weight of 0.8-2.2 kg/mol^-1The polyethylene wax containing terminal double bonds with fluctuation and narrow molecular weight distribution (mostly less than 2.0) can be used as special high-end polyethylene wax, such as food-grade polyethylene wax, and also can be used as comonomer, and shows potential application in the aspects of producing long-chain copolymers, functional polymers and coating materials.

5. In the pyridine diimine compound structure containing bulky benzhydryl substituent groups designed and synthesized by the invention, the aryl imine plane and the coordination plane are basically in vertical positions due to the steric hindrance of the ortho-position benzhydryl, and the active center of metal can be effectively protected. Therefore, the complex has higher activity and better thermal stability.

Drawings

FIG. 1 is a reaction scheme for preparing ligands according to examples 1-5 and complexes according to examples 6-10 of the present invention.

FIG. 2 is a schematic diagram of the crystal structure of the complex Co-1 prepared in example 6.

FIG. 3 is a schematic diagram of the crystal structure of the complex Co-5 prepared in example 10.

FIG. 4 shows a nuclear magnetic thermogram and a nuclear magnetic carbon spectrogram of the polymer obtained in example 11 d).

FIG. 5 shows a nuclear magnetic hydrogen spectrum and a nuclear magnetic carbon spectrum of the polymer obtained in example 16 h).

Detailed Description

The experimental procedures used in the following examples are all conventional procedures unless otherwise specified.

Materials, reagents and the like used in the following examples are commercially available unless otherwise specified.

Both Methylaluminoxane (MAO) and Modified Methylaluminoxane (MMAO) were obtained from Akzo Nobel, USA. In the following examples 11 to 20, Al/Co is defined as the molar ratio of the metal Al in the cocatalyst MAO or MMAO to the Co in the complex.

Example 1 preparation of 2- (1- (2, 4-bis (4-fluorophenyl) methyl-6-fluoroanilino) ethyl) -6- (1- (2, 6-dimethyl-anilino) ethyl) pyridine (ligand L1) represented by the following formula

0.67g (2.50mmol) of 2-acetyl-6- (1- ((2, 6-dimethylphenyl) imino) ethyl) pyridine and 1.55g (3.00mmol) of 2, 4-bis (4-fluorophenyl) methyl) -6-fluoroaniline are weighed out into a reaction flask, about 30mL of toluene solvent are added, heating and stirring are carried out under reflux, half an hour thereafter catalytic equivalents (20%, 0.086g) of p-toluenesulfonic acid are added to the reaction flask, and the reaction mixture is heated and refluxed for 10 hours. Cool to room temperature and evaporate volatiles in vacuo. Then, the obtained crude residual solid was subjected to column chromatography (100:1v/v) using a mixed solvent of petroleum ether and ethyl acetate as an eluent) through an alkaline alumina column to elute, and the solvent was removed to obtain 0.74g of a pale yellow powder, i.e., L1, 2- (1- (2, 4-bis (4-fluorophenyl) methyl-6-fluoroanilino) ethyl) -6- (1- (2, 6-dimethyl-anilino) ethyl) pyridine, in a yield: 39 percent.

The structure validation data is as follows:

FT-IR(cm^-1):3072(w),3046(w),2963(m),1656(ν(C＝N),m),1640(m),1600(m),1574(w),1504(s),1468(m),1433(m),1409(w),1364(m),1301(w),1259(m),1223(s),1203(w),1158(m),1087(m),1016(m),869(m),841(m),794(s),764(m),694(w).

¹H NMR(400MHz,CDCl₃,TMS):δ8.46(d,J＝8.0Hz,1H,Py-H_m),8.30(d,J＝8.0Hz,1H,Py-H_m),7.89(t,J＝8.0Hz,1H,Py-H_p),7.09(d,J＝8.0Hz,2H,aryl-H),6.99-6.87(m,17H,aryl-H),6.74(d,J＝8.0Hz,1H,aryl-H(o-F)),6.40(s,1H,aryl-H),5.57(s,1H,CH(p-FPh)₂),5.41(s,1H,CH(p-FPh)₂),2.18(s,3H,N＝CCH₃),2.06(s,6H,2×CH₃),1.90(s,3H,N＝CCH₃).

¹³C NMR(100MHz,CDCl₃,TMS):δ171.0,167.1,162.8,162.6,160.3,160.2,155.1,154.6,152.0,149.6,148.7,136.8,130.7,130.6,127.9,125.4,123.0,122.4,122.3,115.4,115.2,115.0,54.5,50.6,18.0,17.0,16.4.

¹⁹F NMR(470MHz,CDCl₃):δ–116.21,–116.40,–126.30.

elemental analysis: c₄₉H₃₈F₅N₃(763.86) theoretical value: c, 77.05; h, 5.01; n,5.50. experimental values: c, 76.93; h, 5.16; n,5.42.

Example 2 preparation of 2- (1- (2, 4-bis (4-fluorophenyl) methyl-6-fluoroanilino) ethyl) -6- (1- (2, 6-diethyl-anilino) ethyl) pyridine (ligand L2) of the formula

0.74g (2.50mmol) of 2-acetyl-6- (1- ((2, 6-diethylphenyl) imino) ethyl) pyridine and 1.55g (3.00mmol) of 2, 4-bis (4-fluorophenyl) methyl) -6-fluoroaniline are weighed into a reaction flask, about 30mL of toluene solvent is added, heating and stirring are carried out under reflux, half an hour after which catalytic equivalents (20%, 0.086g) of p-toluenesulfonic acid are added to the reaction flask, and the reaction mixture is heated and refluxed for 10 hours. Cool to room temperature and evaporate volatiles in vacuo. Then, the obtained crude residual solid was subjected to column chromatography (100:1v/v) using a mixed solvent of petroleum ether and ethyl acetate as an eluent) on an alkaline alumina column to elute and remove the solvent, to obtain 0.53g of a pale yellow powder, i.e., L2, 2- (1- (2, 4-bis (4-fluorophenyl) methyl-6-fluoroanilino) ethyl) -6- (1- (2, 6-diethyl-anilino) ethyl) pyridine, in a yield: 27 percent.

The structure validation data is as follows:

FT-IR(cm^-1):3072(w),3046(w),2968(m),1648(ν(C＝N),m),1600(m),1573(m),1504(s),1451(m),1301(w),1222(s),1158(m),1099(m),1018(m),870(m),840(m),794(s),766(m),697(w).

¹H NMR(400MHz,CDCl₃,TMS):δ8.45(d,J＝8.0Hz,1H,Py-H_m),8.30(d,J＝8.0Hz,1H,Py-H_m),7.90(t,J＝6.0Hz,1H,Py-H_p),7.13(d,J＝8.0Hz,2H,aryl-H),7.07-6.85(m,17H,aryl-H),6.74(d,J＝8.0Hz,1H,aryl-H(o-F)),6.41(s,1H,aryl-H),5.57(s,1H,CH(p-FPh)₂),5.41(s,1H,CH(p-FPh)₂),2.48-2.31(m,4H,2×CH₂CH₃),2.20(s,3H,N＝CCH₃),1.90(s,3H,N＝CCH₃),1.16(t,J＝8.0Hz,6H,2×CH₂CH₃).

¹³C NMR(100MHz,CDCl₃,TMS):δ170.1,165.8,161.7,159.3,159.1,154.1,153.6,151.0,148.5,146.7,138.9,138.8,138.0,137.0,136.4,135.8,134.0,133.9,130.1,124.6,122.3,121.4,114.0,113.9,113.7,53.5,49.5,23.6,16.0,15.7,12.7.

¹⁹F NMR(470MHz,CDCl₃):δ–116.21,–116.41,–126.29.

elemental analysis: c₅₁H₄₂F₅N₃(791.91) theoretical value: c, 77.35; h, 5.35; n,5.31. experimental values: c, 77.13; h, 5.42; and N,5.22.

Example 3 preparation of 2- (1- (2, 4-bis (4-fluorophenyl) methyl-6-fluoroanilino) ethyl) -6- (1- (2, 6-diisopropyl-anilino) ethyl) pyridine (ligand L3) having the formula

0.81g (2.50mmol) of 2-acetyl-6- (1- ((2, 6-diisopropylphenyl) imino) ethyl) pyridine and 1.55g (3.00mmol) of 2, 4-bis (4-fluorophenyl) methyl) -6-fluoroaniline are weighed into a reaction flask, about 30mL of toluene solvent is added, heating and stirring are carried out under reflux, half an hour thereafter catalytic equivalents (20%, 0.086g) of p-toluenesulfonic acid are added to the reaction flask, and the reaction mixture is heated under reflux for 10 hours. Cool to room temperature and evaporate volatiles in vacuo. Then, the obtained crude residual solid was subjected to column chromatography (100:1v/v) using a mixed solvent of petroleum ether and ethyl acetate as an eluent) on an alkaline alumina column to elute, and the solvent was removed to obtain 0.62g of a pale yellow powder, i.e., L3, 2- (1- (2, 4-bis (4-fluorophenyl) methyl-6-fluoroanilino) ethyl) -6- (1- (2, 6-diisopropyl-anilino) ethyl) pyridine, in a yield: 30 percent.

The structure validation data is as follows:

FT-IR(cm^-1):3069(w),3041(w),2964(m),1638(ν(C＝N),m),1602(m),1570(m),1505(s),1464(m),1434(m),1408(w),1365(m),1301(w),1222(s),1158(m),1124(m),1100(m),1010(m),831(m),790(s),761(m),718(w),652(m).

¹H NMR(400MHz,CDCl₃,TMS):δ8.45(d,J＝8.0Hz,1H,Py-H_m),8.29(d,J＝8.0Hz,1H,Py-H_m),7.89(t,J＝8.0Hz,1H,Py-H_p),7.18(d,J＝8.0Hz,2H,aryl-H),7.11(t,J＝8.0Hz,1H,aryl-H),6.99-6.85(m,16H,aryl-H),6.74(d,J＝8.0Hz,1H,aryl-H(o-F)),6.40(s,1H,aryl-H),5.56(s,1H,CH(p-FPh)₂),5.40(s,1H,CH(p-FPh)₂),2.79-2.72(m,2H,-CH(CH₃)₂,2.21(s,3H,N＝CCH₃),1.91(s,3H,N＝CCH₃),1.17(d,J＝8.0Hz,12H,-CH(CH₃)₂).

¹³C NMR(100MHz,CDCl₃,TMS):δ163.1,162.9,160.6,160.5,155.5,155.0,152.3,149.9,146.7,140.2,139.3,138.4,138.3,137.7,137.0,136.0,131.0,130.9,130.8,126.0,123.9,123.3,122.7,122.5,115.6,115.5,115.4,115.3,115.0,54.8,50.9,28.6,23.5,23.1,17.3,17.2.

¹⁹F NMR(470MHz,CDCl₃):δ–116.21,–116.40,–126.27.

elemental analysis: c₅₃H₄₆F₅N₃(819.96) theoretical value: c, 77.64; h, 5.65; n,5.12. experimental values: c, 77.53; h, 5.66; and N,5.23.

Example 4 preparation of 2- (1- (2, 4-bis (4-fluorophenyl) methyl-6-fluoroanilino) ethyl) -6- (1- (2,4, 6-trimethyl-anilino) ethyl) pyridine of the formula (ligand L4)

0.70g (2.50mmol) of 2-acetyl-6- (1- ((2,4, 6-trimethylphenyl) imino) ethyl) pyridine and 1.55g (3.00mmol) of 2, 4-bis (4-fluorophenyl) methyl) -6-fluoroaniline are weighed into a reaction flask, about 30mL of toluene solvent is added, heating and stirring are carried out for reflux, after half an hour, p-toluenesulfonic acid of catalytic equivalent (20%, 0.086g) is added into the reaction flask, and the reaction mixture is heated and refluxed for 10 hours. Cool to room temperature and evaporate volatiles in vacuo. Then, the obtained crude residual solid was subjected to column chromatography (100:1v/v) using a mixed solvent of petroleum ether and ethyl acetate as an eluent) through an alkaline alumina column to elute, and the solvent was removed to obtain 0.46g of a pale yellow powder, i.e., L4, 2- (1- (2, 4-bis (4-fluorophenyl) methyl-6-fluoroanilino) ethyl) -6- (1- (2,4, 6-trimethyl-anilino) ethyl) pyridine, in a yield: 24 percent.

The structure validation data is as follows:

FT-IR(cm^-1):3072(w),3046(w),2996(m),1661(ν(C＝N),m),1640(m),1601(m),1574(w),1505(s),1470(m),1432(m),1364(m),1300(w),1223(s),1158(m),1122(m),1091(m),996(m),842(m),823(m),791(m),757(m),699(w).

¹H NMR(400MHz,CDCl₃,TMS):δ8.44(d,J＝8.0Hz,1H,Py-H_m),8.28(d,J＝8.0Hz,1H,Py-H_m),7.88(t,J＝8.0Hz,1H,Py-H_p),7.00-6.84(m,18H,aryl-H),6.73(d,J＝8.0Hz,1H,aryl-H(o-F)),6.39(s,1H,aryl-H),5.56(s,1H,CH(p-FPh)₂),5.40(s,1H,CH(p-FPh)₂),2.30(s,3H,CH₃),2.17(s,3H,N＝CCH₃),2.01(s,6H,2×CH₃),1.88(s,3H,N＝CCH₃).

¹³C NMR(100MHz,CDCl₃,TMS):δ171.1,167.3,162.8,162.6,160.3,160.2,155.3,154.6,152.0,149.6,146.2,139.9,139.1,139.0,138.1,138.0,137.5,136.8,135.1,134.9,132.3,130.7,130.6,130.5,128.6,125.7,125.3,123.4,122.2,115.4,115.2,115.0,114.9,114.7,54.5,50.6,20.8,17.9,17.0,17.2.

¹⁹F NMR(470MHz,CDCl₃):δ–116.33,–116.52,–126.41.

elemental analysis: c₅₀H₄₀F₅N₃(777.88) theoretical value: c, 77.20; h, 5.18; n,5.40. experimental values: c, 77.17; h, 5.23; and N,5.22.

Example 5 2- (1- (2, 4-bis (4-fluorophenyl) methyl-6-fluoroanilino) ethyl) -6- (1- (2, 6-diethyl-4-methyl-anilino) ethyl) pyridine (ligand L5)

0.77g (2.50mmol) of 2-acetyl-6- (1- ((2, 6-diethyl-4-methyl-phenyl) imino) ethyl) pyridine and 1.55g (3.00mmol) of 2, 4-bis (4-fluorophenyl) methyl) -6-fluoroaniline are weighed into a reaction flask, about 30mL of toluene solvent are added, heating and stirring are carried out under reflux, half an hour later, catalytic equivalents (20%, 0.086g) of p-toluenesulfonic acid are added into the reaction flask, and the reaction mixture is heated and refluxed for 10 hours. Cool to room temperature and evaporate volatiles in vacuo. Then, the obtained crude residual solid was subjected to column chromatography (100:1v/v) using a mixed solvent of petroleum ether and ethyl acetate as an eluent) through an alkaline alumina column to elute, and the solvent was removed to obtain 0.59g of a pale yellow powder, i.e., L5, 2- (1- (2, 4-bis (4-fluorophenyl) methyl-6-fluoroanilino) ethyl) -6- (1- (2, 6-diethyl-4-methyl-anilino) ethyl) pyridine, in terms of yield: 29 percent.

The structure validation data is as follows:

FT-IR(cm^-1):3072(w),3046(w),2969(m),1642(ν(C＝N),m),1601(m),1571(m),1505(s),1460(m),1363(w),1297(w),1223(s),1158(m),1092(m),1017(m),841(m),793(m),757(m),699(w).

¹H NMR(400MHz,CDCl₃,TMS):δ8.44(d,J＝8.0Hz,1H,Py-H_m),8.29(d,J＝8.0Hz,1H,Py-H_m),7.89(t,J＝6.0Hz,1H,Py-H_p),6.99-6.85(m,18H,aryl-H),6.74(d,J＝8.0Hz,1H,aryl-H(o-F)),6.40(s,1H,aryl-H),5.56(s,1H,CH(p-FPh)₂),5.41(s,1H,CH(p-FPh)₂),2.44-2.27(m,7H,2×CH₂CH₃,CH₃),2.19(s,3H,N＝CCH₃),1.90(s,3H,N＝CCH₃),1.14(t,J＝8.0Hz,6H,2×CH₂CH₃).

¹³C NMR(100MHz,CDCl₃,TMS):δ171.2,167.1,162.9,162.7,160.4,160.3,155.4,154.7,152.1,149.7,145.3,140.0,139.2,139.1,138.2,138.1,137.5,136.9,135.2,135.1,132.6,131.2,130.8,130.7,130.6,126.8,125.8,122.5,122.3,115.5,115.3,115.1,115.0,114.8,54.6,50.7,24.7,21.1,17.1,16.8,14.0.

¹⁹F NMR(470MHz,CDCl₃):δ–116.22,–116.42,–126.29.

elemental analysis: c₅₂H₄₄F₅N₃(805.94) theoretical value: c, 77.50; h, 5.50; n,5.21. experimental values: c, 77.43; h, 5.56; and N,5.12.

EXAMPLE 6 preparation of 2- (1- (2, 4-bis (4-fluorophenyl) methyl-6-fluoroanilino) ethyl) -6- (1- (2, 6-dimethyl-anilino) ethyl) pyridine Co Complex (Co-1)

150mg (0.20mmol) of 2- (1- (2, 4-bis (4-fluorophenyl) methyl-6-fluoroanilino) ethyl) -6- (1- (2, 6-dimethyl-anilino) ethyl) pyridine (L1) and 250mg (0.19mmol) of C.degree.C.. L₂Dissolved in 10mL of ethanol under a nitrogen atmosphere. After the stirring was turned on, the color of the solution quickly turned brown. The suspension was stirred at room temperature for 12h to ensure adequate reaction. All solvents were removed by evaporation in vacuo, the residue was dissolved with a small amount of dichloro (2mL) and recrystallized from ether (6mL) and hexane (15mL) to give a precipitate. The precipitate was collected by filtration and washed with hexane (3X 5 mL). 129mg of a tan powder was obtained, namely Co-1, yield: 76 percent.

A schematic diagram of the Co-1 crystal structure is shown in FIG. 2.

As can be seen from FIG. 2, the central metal Co of the complex Co-1 is connected with three nitrogen atoms N1, N2 and N3 and two chlorine atoms Cl1 and Cl2 respectively in a penta-coordinate manner, and is in a twisted tetragonal pyramid structure. Three of the nitrogen atoms form a tetragonal pyramid base with Cl2 atoms, and Cl1 occupies the tetragonal pyramid tip. Due to steric effect, the Co atoms are spaced from the cone top Cl1 atoms by about

The distance between each atom of the substrate and the Co atom is N (1) -Co (1), N (3) -Co (1), N (2) -Co (1) and Cl (1) -Co (1) in sequence

And

furthermore, the imine group is nearly coplanar with the pyridine ring, the plane of the 2, 4-bis (4-fluorophenyl) methyl) -6-fluoro-phenyl group on one side is nearly perpendicular to the planar backbone of the pyramid base, the twist angle is 89.17 °, and the twist angle between the plane of the aryl ring on the other side and the planar backbone of the pyramid base is slightly smaller, 87.48 °.

The structure validation data is as follows:

FT-IR(cm^-1):3072(w),3046(w),2963(m),1628(ν(C＝N),m),1589(m),1506(s),1474(m),1432(m),1373(m),1297(w),1262(m),1221(s),1158(m),1098(m),1027(m),1016(m),1001(m),823(m),792(s),776(m),763(m),723(m),670(w).

¹⁹F NMR(470MHz,CDCl₃):δ–114.95,–115.43,–116.30,–119.76,–154.81.

elemental analysis: c₄₉H₃₈Cl₂CoF₅N₃(893.69) theoretical value C, 65.85; h, 4.29; n,4.70. experimental values: c, 65.73; h, 4.36; and N,4.66.

EXAMPLE 7 preparation of 2- (1- (2, 4-bis (4-fluorophenyl) methyl-6-fluoroanilino) ethyl) -6- (1- (2, 6-diethyl-anilino) ethyl) pyridine Co Complex (Co-2)

79mg (0.10mmol) of 2- (1- (2, 4-bis (4-fluorophenyl) methyl-6-fluoroanilino) ethyl) -6- (1- (2, 6-diethyl-anilino) ethyl) pyridine (L2) and 125mg (0.095mmol) of CoCl₂Dissolved in 10mL of ethanol under a nitrogen atmosphere. After the stirring was turned on, the color of the solution quickly turned brown. The suspension was stirred at room temperature for 12h to ensure adequate reaction. All solvents were removed by evaporation in vacuo, the residue was dissolved with a small amount of dichloro (2mL) and recrystallized from ether (6mL) and hexane (15mL) to give a precipitate. The precipitate was collected by filtration and washed with hexane (3X 5 mL). 71mg of a tan powder was obtained, namely Co-2, yield: 81 percent.

The structure validation data is as follows:

FT-IR(cm^-1):3072(w),3046(w),2972(m),1602(ν(C＝N),m),1583(m),1507(s),1477(m),1434(m),1374(s),1301(m),1264(m),1227(s),1159(m),1098(m),1022(m),814(m),770(m),669(w).

¹⁹F NMR(470MHz,CDCl₃):δ–114.96,–115.35,–116.42,–119.57,–151.80.

elemental analysis: c₅₁H₄₂Cl₂CoF₅N₃(921.74) theoretical value: c, 66.46; h, 4.59; n,4.56. experimental values: c, 66.19; h, 4.81; and N,4.50.

EXAMPLE 8 preparation of 2- (1- (2, 4-bis (4-fluorophenyl) methyl-6-fluoroanilino) ethyl) -6- (1- (2, 6-diisopropyl-anilino) ethyl) pyridine Co complex (Co-3)

82mg (0.10mmol) of 2- (1- (2, 4-bis (4-fluorophenyl) methyl-6-fluoroanilino) ethyl) -6- (1- (2, 6-diisopropyl-anilino) ethyl) pyridine (L3) and 125mg (0.095mmol) of CoCl₂Dissolved in 10mL of ethanol under a nitrogen atmosphere. After the stirring was turned on, the color of the solution quickly turned brown. The suspension was stirred at room temperature for 12h to ensure adequate reaction. All solvents were removed by evaporation in vacuo, the residue was dissolved with a small amount of dichloro (2mL) and recrystallized from ether (6mL) and hexane (15mL) to give a precipitate. The precipitate was collected by filtration and washed with hexane (3X 5 mL). 71mg of a tan powder was obtained, namely Co-3, yield: 79 percent.

The structure validation data is as follows:

FT-IR(cm^-1):3067(w),3041(w),2962(m),1609(ν(C＝N),m),1583(m),1510(s),1474(m),1428(m),1373(m),1323(w),1295(w),1267(m),1222(s),1158(m),1122(m),831(s),796(m),769(m),720(w),693(m).

¹⁹F NMR(470MHz,CDCl₃):δ–114.99,–115.25,–117.53,–117.84,–139.63.

elemental analysis C₅₃H₄₆Cl₂CoF₅N₃(949.80) theoretical value: c, 67.02; h, 4.88; n,4.42. experimental values: c, 66.93; h, 4.89; and N,4.29.

EXAMPLE 9 preparation of 2- (1- (2, 4-bis (4-fluorophenyl) methyl-6-fluoroanilino) ethyl) -6- (1- (2,4, 6-trimethyl-anilino) ethyl) pyridine Co Complex (Co-4)

78mg (0.10mmol) of 2- (1- (2, 4-bis (4-fluorophenyl) methyl-6-fluoroanilino) ethyl) -6- (1- (2,4, 6-trimethyl-anilino) ethyl) pyridine (L4) and 125mg (0.095mmol) of CoCl₂Dissolved in 10mL of ethanol under a nitrogen atmosphere. After the stirring was turned on, the color of the solution quickly turned brown. The suspension was stirred at room temperature for 12h to ensure adequate reaction. All solvents were removed by evaporation in vacuo, the residue was dissolved with a small amount of dichloro (2mL) and recrystallized from ether (6mL) and hexane (15mL) to give a precipitate. The precipitate was collected by filtration and washed with hexane (3X 5 mL). 53mg of tan powder were obtained, namely Co-4, yield: 61 percent.

The structure validation data is as follows:

FT-IR(cm^-1):3072(w),3046(w),2996(m),1631(ν(C＝N),m),1597(m),1506(s),1479(m),1429(m),1373(m),1295(w),1262(m),1225(s),1157(m),1097(m),996(m),857(m),832(s),789(m),761(m),739(w),700(m).

¹⁹F NMR(470MHz,CDCl₃):δ–114.78,–115.24,–116.02,–119.67,–154.41.

elemental analysis: c₅₀H₄₀Cl₂CoF₅N₃(907.72) theoretical value: c, 66.16; h, 4.44; n,4.63. experimental values: c, 65.98; h, 4.56; n,4.52.

EXAMPLE 10 preparation of 2- (1- (2, 4-bis (4-fluorophenyl) methyl-6-fluoroanilino) ethyl) -6- (1- (2, 6-diethyl-4-methyl-anilino) ethyl) pyridine Co Complex (Co-5)

81mg (0.10mmol) of 2- (1- (2, 4-bis (4-fluorophenyl) methyl-6-fluoroanilino) ethyl) -6- (1- (2, 6-diethyl-4-methylanilino) ethyl) pyridine (L1) and 125mg (0.095mmol) of CoCl₂Dissolved in 10mL of ethanol under a nitrogen atmosphere. After the stirring was turned on, the color of the solution quickly turned brown. The suspension was stirred at room temperature for 12h to ensure adequate reaction. All solvents were removed by evaporation in vacuo, the residue was dissolved with a small amount of dichloro (2mL) and recrystallized from ether (6mL) and hexane (15mL) to give a precipitate. The precipitate was collected by filtration and washed with hexane (3X 5 mL). 63mg of tan powder were obtained, namely Co-5, yield: 71 percent.

A schematic diagram of the Co-5 crystal structure is shown in FIG. 3.

As can be seen from the figure, the central metal Co of the complex Co-5 is connected with three nitrogen atoms N1, N2 and N3 and two chlorine atoms Cl1 and Cl2 respectively in a penta-coordination mode, and is in a twisted tetragonal pyramid structure. Three of the nitrogen atoms form a tetragonal pyramid base with Cl2 atoms, and Cl1 occupies the tetragonal pyramid tip. Due to steric effect, the Co atoms are spaced from the cone top Cl1 atoms by about

The distance between each atom of the substrate and the Co atom is N (1) -Co (1), N (3) -Co (1), N (2) -Co (1) and Cl (2) -Co (1) in sequence

2.028(4) and

furthermore, the imine group is nearly coplanar with the pyridine ring, the plane of the 2, 4-bis (4-fluorophenyl) methyl) -6-fluoro-phenyl group on one side is nearly perpendicular to the planar backbone of the pyramid base, the twist angle is 85.77 °, and the twist angle between the plane of the aryl ring on the other side and the planar backbone of the pyramid base is 86.56 ° and slightly smaller.

The structure validation data is as follows:

FT-IR(cm^-1):3072(w),3046(w),2966(m),1602(ν(C＝N),m),1585(m),1506(s),1467(m),1373(w),1298(w),1262(m),1225(s),1158(m),1097(m),1022(m),822(s),792(m),761(m),670(m).

¹⁹F NMR(470MHz,CDCl₃):δ–114.96,–115.37,–116.40,–119.71,–151.73.

elemental analysis: c₅₂H₄₄Cl₂CoF₅N₃(935.77) theoretical value: c, 66.74; h, 4.74; n,4.49 experimental values: c, 66.55; h, 4.88; and N,4.60.

Example 11 Co-catalysis of ethylene polymerization under high pressure with Complex Co-1 and cocatalyst MAO

a) 30ml of a toluene solution of the catalyst Co-1(2. mu. mol) were injected under an ethylene atmosphere into 250ml of a machine equipped with a stirrerA stirred stainless steel autoclave was then charged with 30mL of toluene, the desired amount of 2.7mL of co-catalyst MAO (1.46mol/L in toluene) was added, and the toluene addition was continued to bring the total volume of the reaction solution to 100 mL. At this point, Al/Co is 2000: 1. Mechanical stirring is started, 400 rpm is maintained, and when the polymerization temperature reaches 40 ℃, ethylene is charged into the reaction kettle, and the polymerization reaction starts. The polymerization was carried out for 30min with stirring while maintaining the ethylene pressure of 10atm at 40 ℃. Neutralizing the reaction solution with 10% hydrochloric acid acidified ethanol solution to obtain polymer precipitate, washing with ethanol for several times, drying at 50 deg.C under vacuum to constant weight, weighing to obtain 6.32g polymer, polymerization activity: 6.32X 10⁶g/mol(Co)h^-1Polymerization molecular weight M_w＝1337g mol^-1Molecular weight distribution M_w/M_nIs 1.8 (M)_wIs the mass average molecular weight of the polymer, M_nNumber average molecular weights of the polymers, all by GPC measurement) of the polymer T_m＝120.8℃(T_mMelting temperature of the polymer, obtained by DSC test).

b) Basically, the method a) in the embodiment is different: the polymerization temperature was 50 ℃. Polymerization Activity: 10.27X 10⁶g/mol(Co)h^-1Polymerization molecular weight M_w＝1223g mol^-1Molecular weight distribution M_w/M_nIs 1.8, Polymer T_m＝120.0℃。

c) Basically, the method a) in the embodiment is different: the polymerization temperature was 60 ℃. Polymerization Activity: 10.97X 10⁶g/mol(Co)h^-1Polymerization molecular weight M_w＝1017g mol^-1Molecular weight distribution M_w/M_nIs 1.6, Polymer T_m＝121.3℃。

d) Basically, the method a) in the embodiment is different: the polymerization temperature was 70 ℃. Polymerization Activity: 11.67X 10⁶g/mol(Co)h^-1Polymerization molecular weight M_w＝924g mol^-1Molecular weight distribution M_w/M_nIs 1.4, polymer T_m＝119.2℃。

The polymer obtained was taken at 100mg and dissolved in 3ml of deuterated 1,1,2, 2-tetrachloroethane, and the polymer was tested at 100 ℃¹H data, e.g.As shown in fig. 4. The signal was accumulated 100 times, two sets of multiple signal peaks were obtained at shifts 5.89(ppm) and 5.02(ppm), which proved to be vinyl groups (-CH ═ CH)₂)。

The polymer obtained was taken at 100mg and dissolved in 3ml of deuterated 1,1,2, 2-tetrachloroethane, and the polymer was tested at 100 ℃¹³C data, as shown in fig. 4. The signal was accumulated 3000 times and two sets of signal peaks were obtained at the shifts 113.80(ppm) and 138.87(ppm), indicating vinyl ends of long chains of polyethylene, demonstrating that the resulting polymer is a highly linear polyethylene.

e) Basically, the method a) in the embodiment is different: the polymerization temperature was 80 ℃. Polymerization Activity: 4.97X 10⁶g/mol(Co)h^-1Polymerization molecular weight M_w＝901g mol^-1Molecular weight distribution M_w/M_nIs 1.5, Polymer T_m＝119.6℃。

f) Basically, the method a) in the embodiment is different: the polymerization temperature was 90 ℃. Polymerization Activity: 2.83X 10⁶g/mol(Co)h^-1Polymerization molecular weight M_w＝872g mol^-1Molecular weight distribution M_w/M_nIs 1.5, Polymer T_m＝122.0℃。

g) Basically the same as the method d) in the embodiment, the difference is that: cocatalyst MAO (1.46mol/L in toluene) was used in an amount of 1.4mL such that Al/Co ═ 1000: 1. polymerization Activity: 0.70X 10⁶g/mol(Co)h^-1Polymerization molecular weight M_w＝986g mol^-1Molecular weight distribution M_w/M_nIs 1.4, polymer T_m＝121.6℃。

h) Basically the same as the method d) in the embodiment, the difference is that: cocatalyst MAO (1.46mol/L in toluene) was used in an amount of 2.1mL such that Al/Co 1500: 1. polymerization Activity: 1.36X 10⁶g/mol(Co)h^-1Polymerization molecular weight M_w＝981g mol^-1Molecular weight distribution M_w/M_nIs 1.5, Polymer T_m＝121.1℃。

i) Basically the same as the method d) in the embodiment, the difference is that: cocatalyst MAO (1.46mol/L in toluene) was used in an amount of 2.4mL such that Al/Co 1750: 1. polymerization Activity: 4.34X 10⁶g/mol(Co)h^-1Polymerization molecular weight M_w＝950g mol^-1Molecular weight distribution M_w/M_nIs 1.6, Polymer T_m＝122.8℃。

j) Basically the same as the method d) in the embodiment, the difference is that: cocatalyst MAO (1.46mol/L in toluene) was used in an amount of 3.1mL such that Al/Co 2250: 1. polymerization Activity: 9.87X 10⁶g/mol(Co)h^-1Polymerization molecular weight M_w＝872kg mol^-1Molecular weight distribution M_w/M_nIs 1.6, Polymer T_m＝121.3℃。

k) Basically the same as the method d) in the embodiment, the difference is that: cocatalyst MAO (1.46mol/L in toluene) was used in an amount of 3.4mL such that Al/Co ═ 2500: 1. polymerization Activity: 8.54X 10⁶g/mol(Co)h^-1Polymerization molecular weight M_w＝862g mol^-1Molecular weight distribution M_w/M_nIs 1.6, Polymer T_m＝119.5℃。

l) is basically the same as the method d) in the embodiment, except that: cocatalyst MAO (1.46mol/L in toluene) was used in 4.1mL so that Al/Co 3000: 1. polymerization Activity: 5.57X 10⁶g/mol(Co)h^-1Polymerization molecular weight M_w＝816g mol^-1Molecular weight distribution M_w/M_nIs 1.6, Polymer T_m＝121.1℃。

m) is basically the same as the method d) in the embodiment, except that: the polymerization time was 5 min. Polymerization Activity: 27.30X 10⁶g/mol(Co)h^-1Polymerization molecular weight M_w＝808g mol^-1Molecular weight distribution M_w/M_nIs 1.6, Polymer T_m＝119.2℃。

n) is basically the same as the method d) in the embodiment, except that: the polymerization time was 15 min. Polymerization Activity: 14.12X 10⁶g/mol(Co)h^-1Polymerization molecular weight M_w＝911g mol^-1Molecular weight distribution M_w/M_nIs 1.5, Polymer T_m＝122.5℃。

o) is basically the same as the method d) in the embodiment, except that: the polymerization time was 45 min. Polymerization Activity: 9.17X 10⁶g/mol(Co)h^-1Polymerization molecular weight M_w＝1005g mol^-1Molecular weight distribution M_w/M_nIs 1.7, Polymer T_m＝122.1℃。

p) is basically the same as the method d) in the embodiment, except that: the polymerization time was 60 min. Polymerization Activity: 7.10X 10⁶g/mol(Co)h^-1Polymerization molecular weight M_w＝1126g mol^-1Molecular weight distribution M_w/M_nIs 1.8, Polymer T_m＝122.9℃。

q) is basically the same as the method d) in the embodiment, except that: the polymerization pressure was 1 atm. Polymerization Activity: 0.27X 10⁶g/mol(Co)h^-1Polymerization molecular weight M_w＝824g mol^-1Molecular weight distribution M_w/M_nIs 1.4, polymer T_m＝115.7℃。

r) is basically the same as the method d) in the embodiment, except that: the polymerization pressure was 5 atm. Polymerization Activity: 5.77X 10⁶g/mol(Co)h^-1Polymerization molecular weight M_w＝851g mol^-1Molecular weight distribution M_w/M_nIs 1.5, Polymer T_m＝120.1℃。

Example 12 polymerization of ethylene under pressure Using Co-2 Complex and MAO in combination

Essentially the same as example 11d), except that: the main catalyst is Co-2. Polymerization Activity: 6.72X 10⁶g/mol(Co)h^-1Polymerization molecular weight M_w＝1448g mol^-1Molecular weight distribution M_w/M_nIs 1.9, Polymer T_m＝124.1℃。

Example 13 polymerization of ethylene under pressure Using Co-3 Complex and MAO in combination

Essentially the same as example 11d), except that: a main catalyst Co-3. Polymerization Activity: 3.66X 10⁶g/mol(Co)h^-1Polymerization molecular weight M_w＝4782g mol^-1Molecular weight distribution M_w/M_nIs 2.4, Polymer T_m＝127.7℃。

Example 14 polymerization of ethylene under pressure Using Co-4 Complex and MAO in combination

Essentially the same as example 11d), except that: the main catalyst is Co-4. Polymerization Activity: 8.07X 10⁶g/mol(Co)h^-1Polymerization molecular weight M_w＝945g mol^-1Molecular weight distribution M_w/M_nIs 1.7, Polymer T_m＝121.1℃。

Example 15 polymerization of ethylene under pressure Using Co-5 Complex and MAO in combination

Essentially the same as example 11d), except that: the main catalyst is Co-5. Polymerization Activity: 5.77X 10⁶g/mol(Co)h^-1Polymerization molecular weight M_w＝1771g mol^-1Molecular weight distribution M_w/M_nIs 1.9, Polymer T_m＝123.4℃。

Example 16 polymerization of ethylene under pressure Using Co-1 and MMAO complexes in combination

a) 30mL of a toluene solution of the catalyst Co-1 (2.0. mu. mol) was injected under an ethylene atmosphere into a 250mL stainless steel autoclave equipped with mechanical stirring, followed by addition of 30mL of toluene, addition of the required amount of 2.0mL of the cocatalyst MMAO (2.0mol/L in toluene), and further addition of toluene so that the total volume of the reaction solution became 100 mL. At this point, Al/Co is 2000: 1. Mechanical stirring is started, 400 rpm is maintained, and when the polymerization temperature reaches 40 ℃, ethylene is charged into the reaction kettle, and the polymerization reaction starts. The polymerization was carried out for 30min with stirring while maintaining the ethylene pressure of 10atm at 40 ℃. Neutralizing the reaction solution with 10% hydrochloric acid acidified ethanol solution to obtain polymer precipitate, washing with ethanol for several times, drying at 50 deg.C under vacuum to constant weight, weighing to obtain 4.21g polymer, polymerization activity: 4.21X 10⁶g/mol(Co)h^-1Polymerization molecular weight M_w＝1255g mol^-1Molecular weight distribution M_w/M_nIs 1.7 (M)_wIs the mass average molecular weight of the polymer, M_nNumber average molecular weights of the polymers, all by GPC measurement) of the polymer T_m＝120.1℃(T_mMelting temperature of the polymer, obtained by DSC test).

b) Basically, the method a) in the embodiment is different: the polymerization temperature was 50 ℃. Polymerization Activity: 10.28X 10⁶g/mol(Co)h^-1Polymerization molecular weight M_w＝974g mol^-1Molecular weight distribution M_w/M_nIs 1.7, Polymer T_m＝118.2℃。

c) Basically, the method a) in the embodiment is different: the polymerization temperature was 60 ℃. Polymerization Activity: 10.53X 10⁶g/mol(Co)h^-1Polymerization molecular weight M_w＝963g mol^-1Molecular weight distribution M_w/M_nIs 1.7, Polymer T_m＝118.3℃。

d) Basically, the method a) in the embodiment is different: the polymerization temperature was 70 ℃. Polymerization Activity: 6.22X 10⁶g/mol(Co)h^-1Polymerization molecular weight M_w＝943g mol^-1Molecular weight distribution M_w/M_nIs 1.7, Polymer T_m＝118.2℃。

e) Basically, the method a) in the embodiment is different: the polymerization temperature was 80 ℃. Polymerization Activity: 3.59X 10⁶g/mol(Co)h^-1Polymerization molecular weight M_w＝901g mol^-1Molecular weight distribution M_w/M_nIs 1.6, Polymer T_m＝119.6℃。

f) Basically the same as the method c) in the embodiment, the difference is that: cocatalyst MMAO (2.0mol/L in toluene) was used in an amount of 1.0mL such that Al/Co is 1000: 1. polymerization Activity: 7.95X 10⁶g/mol(Co)h^-1Polymerization molecular weight M_w＝1049g mol^-1Molecular weight distribution M_w/M_nIs 1.7, Polymer T_m＝119.5℃。

g) Basically the same as the method c) in the embodiment, the difference is that: cocatalyst MMAO (2.0mol/L in toluene) was used in an amount of 1.5mL such that Al/Co is 1500: 1. polymerization Activity: 8.56X 10⁶g/mol(Co)h^-1Polymerization molecular weight M_w＝982g mol^-1Molecular weight distribution M_w/M_nIs 1.7, Polymer T_m＝117.9℃。

h) Basically the same as the method c) in the embodiment, the difference is that: cocatalyst MMAO (2.0mol/L in toluene) was used in an amount of 2.5mL such that Al/Co ═ 2500: 1. polymerization Activity: 10.99X 10⁶g/mol(Co)h^-1Polymerization molecular weight M_w＝962g mol^-1Molecular weight distribution M_w/M_nIs 1.7, Polymer T_m＝118.3℃。

The polymer obtained, 100mg, was dissolved in 3ml of deuterated 1,1,2, 2-tetrachloroethane and tested at 135 ℃¹H data, as shown in fig. 5. The signals are accumulated 128 times.

The polymer obtained, 100mg, was dissolved in 3ml of deuterated 1,1,2, 2-tetrachloroethane and tested at 135 ℃¹³C data, as shown in fig. 5. The signal is accumulated 3000 times.

i) Basically the same as the method c) in the embodiment, the difference is that: cocatalyst MMAO (2.0mol/L in toluene) was used in an amount of 3.0mL such that Al/Co was 3000: 1. polymerization Activity: 9.25X 10⁶g/mol(Co)h^-1Polymerization molecular weight M_w＝946g mol^-1Molecular weight distribution M_w/M_nIs 1.7, Polymer T_m＝118.3℃。

j) Basically, the method h in the embodiment is different in that: the polymerization time was 5 min. Polymerization Activity: 26.16X 10⁶g/mol(Co)h^-1Polymerization molecular weight M_w＝891g mol^-1Molecular weight distribution M_w/M_nIs 1.5, Polymer T_m＝120.9℃。

k) Basically the same as the method h) in the embodiment, the difference is that: the polymerization time was 15 min. Polymerization Activity: 14.46X 10⁶g/mol(Co)h^-1Polymerization molecular weight M_w＝928g mol^-1Molecular weight distribution M_w/M_nIs 1.7, Polymer T_m＝120.1℃。

l) is basically the same as the method h) in the embodiment, except that: the polymerization time was 45 min. Polymerization Activity: 8.37X 10⁶g/mol(Co)h^-1Polymerization molecular weight M_w＝1019g mol^-1Molecular weight distribution M_w/M_nIs 1.7, Polymer T_m＝119.2℃。

m) is substantially the same as method h) in the present embodiment, except that: the polymerization time was 60 min. Polymerization Activity: 6.88X 10⁶g/mol(Co)h^-1Molecular weight of polymerizationM_w＝1206g mol^-1Molecular weight distribution M_w/M_nIs 1.6, Polymer T_m＝118.5℃。

n) is basically the same as the method h) in the embodiment, except that: the polymerization pressure was 1 atm. Polymerization Activity: 0.18X 10⁶g/mol(Co)h^-1Polymerization molecular weight M_w＝794g mol^-1Molecular weight distribution M_w/M_nIs 1.2, Polymer T_m＝117.3℃。

o) is basically the same as the method h) in the embodiment, except that: the polymerization pressure was 5 atm. Polymerization Activity: 5.14X 10⁶g/mol(Co)h^-1Polymerization molecular weight M_w＝854g mol^-1Molecular weight distribution M_w/M_nIs 1.5, Polymer T_m＝119.2℃。

Example 17 polymerization of ethylene under pressure Using Co-2 and MMAO complexes in combination

Essentially the same as example 16h), except that: the main catalyst is Co-2. Polymerization Activity: 6.58X 10⁶g/mol(Co)h^-1Polymerization molecular weight M_w＝1827g mol^-1Molecular weight distribution M_w/M_nIs 2.0, polymer T_m＝122.2℃。

Example 18 polymerization of ethylene under pressure Using Co-3 Complex and MMAO in combination

Essentially the same as example 16h), except that: the main catalyst is Co-3. Polymerization Activity: 3.48X 10⁶g/mol(Co)h-¹Polymerization molecular weight M_w＝5550gmol-¹Molecular weight distribution M_w/M_nIs 2.2, Polymer T_m＝127.9℃。

Example 19 polymerization of ethylene under pressure Using Co-4 and MMAO complexes in combination

Essentially the same as example 16h), except that: the main catalyst is Co-4. Polymerization Activity: 7.20X 10⁶g/mol(Co)h^-1Polymerization molecular weight M_w＝1096g mol^-1Molecular weight distribution M_w/M_nIs 1.7, Polymer T_m＝119.6℃。

Example 20 polymerization of ethylene under pressure Using Co-5 and MMAO complexes in combination

Essentially the same as example 16h), except that: the main catalyst is Co-5. Polymerization Activity: 5.30X 10⁶g/mol(Co)h^-1Polymerization molecular weight M_w＝2186g mol^-1Molecular weight distribution M_w/M_nIs 2.0, polymer T_m＝123.3℃。

The experiments show that 1, the catalytic activity of the catalyst is 10.27-11.67 x 10 under the condition of 50-70 ℃ by using MAO as a cocatalyst⁶g·mol^-1(Co)h^-1Small floating, high thermal stability, even at 90 deg.C, the catalytic activity can still be maintained at 2.83X 10⁶g·mol^-1(Co)h^-1The operation temperature of industrial production is met; 2. the cocatalyst has little influence on polymerization activity and polymer molecular weight in a preferable dosage range, and the synthesized molecular weight is low, and most of the cocatalyst is 0.8-2.2kg & mol^-1Fluctuate between; 3. the influence on the polymerization activity is not large in the preferable reaction time, and the catalytic life of the complex in the polymerization process is longer; 4. the catalytic performance of different main catalysts in examples 17-20 of the present invention is excellent, but the catalytic activity and the properties of the obtained polymer of the complexes with different structures are different, which indicates that the activity and the properties of the polymer are related to the steric hindrance and the electronic effect of the catalyst, because in the structure of the pyridine diimine complex containing bulky benzhydryl substituents designed and synthesized by the present invention, the aryl imine plane and the coordination plane are basically in the vertical position due to the steric hindrance of the ortho-benzhydryl group, and effective protection can be formed on the metal active center, for example, the activity of the cobalt complex catalyzing ethylene polymerization can be as high as 11.67 × 10at 70 ℃⁶g·mol^-1(Co)·h^-1。

Claims

1. A transition metal complex having the formula (I):

in the formula (I), M is selected from iron or cobalt;

x is selected from F, Cl, Br and I, and two X are the same or different;

R^aselected from H, F, Cl, Br, I, unsubstituted or optionally substituted by one or more R^cSubstituted C_1-6Alkyl radical, C_1-6Alkoxy radical, C_3-10Cycloalkyl radical, C_3-10Cycloalkyloxy, aryl or aryloxy, and each R^aThe same or different;

2. The transition metal complex according to claim 1, characterized in that: in the formula (I), R¹、R²Are all selected from H, C_1-3Alkyl radicalAnd each R is¹、R²Are the same or different; specifically, the compound can be selected from H, methyl, ethyl, n-propyl and isopropyl;

x is selected from Cl or Br, and two X are the same or different.

3. A compound having the formula (II):

in the formula (II), R¹、R²、R³、R⁴、R⁵The same as in the transition metal complex represented by the formula (I) of claim 1 or 2.

4. A process for the preparation of a compound of formula (II) according to claim 3, comprising the steps of:

in the formulae (III) and (IV), R¹、R²、R³、R⁴、R⁵The same as in the transition metal complex represented by the formula (I) of claim 1 or 2.

5. The method of claim 4, wherein: the condensation reaction is carried out under the catalysis of p-toluenesulfonic acid, and the solvent is at least one of toluene, o-xylene and o-dichlorobenzene; the heating reflux time is 7-10 h;

6. Use of a compound of formula (II) for the preparation of said transition metal complex of formula (I) according to claim 1 or 2.

7. A process for preparing the transition metal complex of formula (I) according to claim 1 or 2, comprising the steps of: reacting a compound of formula (II) according to claim 3 with a compound MX₂Or a hydrate thereof is subjected to a complex reaction to obtain a complex shown in the formula (I);

wherein M, X is the same as in the transition metal complex represented by the formula (I) of claim 1 or 2;

and/or, the complexation reaction is performed under anaerobic conditions;

said compound MX₂The molar ratio of the compound to the compound represented by the formula (II) is 1:1 to 1.5, preferably 1:1 to 1.3, and more preferably 1: 1.1.

8. Use of the transition metal complex of formula (I) according to claim 1 or 2 for catalyzing the polymerization of olefins.

9. A catalyst composition characterized by: the catalyst composition consists of a main catalyst and a cocatalyst;

wherein the procatalyst is the transition metal complex represented by formula (I) of claim 1 or 2;

the cocatalyst is selected from at least one of aluminoxane, alkyl aluminum and alkyl aluminum chloride; the aluminoxane is specifically selected from methylaluminoxane and/or triisobutyl aluminum modified methylaluminoxane; the alkyl in the alkyl aluminum and the alkyl chloride is specifically selected from alkyl with 1-3 carbon atoms;

the molar ratio of the central metal M of the main catalyst to the metal Al in the cocatalyst is specifically 500-4000: 1.

10. A process for producing an olefin polymer, comprising the steps of: catalyzing olefin to carry out polymerization reaction under the action of the transition metal complex shown in the formula (I) of claim 1 or 2 or the catalyst composition shown in the claim 9 to obtain an olefin polymer;

the temperature of the polymerization reaction is specifically 30-100 ℃;

the polymerization reaction time is specifically 5-60 min;

the pressure of the polymerization reaction is specifically 0.5-10 atm.