Post-transition metal complexes, methods of making and using the same

Abstract

The application discloses a kind of post-transition metal complexes and preparation method and application thereof, and the post-transition metal complex provided by the application can be applied to the polymerization of ethylene as catalyst, and the molecular weight of polymer is regulated by changing ligand structure and polymerization condition;Especially by changing its metal center, the molecular weight distribution of polyethylene has obvious regulating effect, wherein the polyethylene obtained by iron complex catalysis has relatively wide molecular weight distribution (M w / M n :2.0-10.7), and the molecular weight of polyethylene obtained by cobalt complex catalysis is mostly narrow (M w / M n :1.6-2.2), and both can be used to prepare highly linear polyethylene.The preparation method of the complex described in the application has the advantages of mild conditions, short cycle, simple operation, etc.The complex prepared by the method shows high catalytic activity, which can be up to 2.56×10 7 g (PE) (mol Fe) ‑1 h ‑1 , and high thermal stability, which meets the operating temperature of industrial production and has further industrial application prospect.

Description

Technical Field

[0001] The present invention relates to the technical field of polyolefin catalysts, in particular to a late transition metal iron-cobalt complex for preparing highly linear polyethylene, and a preparation method and application thereof. Background Art

[0002] Polyethylene (PE) has become the most produced general-purpose synthetic resin due to its excellent mechanical properties, good processing characteristics, stable chemical properties, and low price. It is widely used in daily life, packaging, automotive, construction, agriculture, and military applications. my country is currently the world's largest importer and second-largest consumer of PE. The properties and industrial applications of polyethylene materials are largely determined by their chain size and topology. Linear polyethylene, a type of polyethylene with only short side chains and no long side chains on the main molecule, typically includes high-density polyethylene (HDPE), ultra-high molecular weight polyethylene (UHMWPE), linear low-density polyethylene (LLDPE), and very low-density polyethylene (VLDPE). It is primarily produced by polymerization under low pressure using Ziegler-Natta or Phillips catalysts. However, due to limitations in the synthesis process, the narrow molecular weight distribution of the polymers cannot be achieved. Therefore, researchers have turned their attention to late transition metal complexes, which have attracted considerable attention due to their excellent properties and the highly linear nature of the resulting polymers.

[0003] The inventors' research group has been dedicated to the design and development of olefin polymerization catalysts and the exploration of catalytic processes, focusing on late-transition metal catalysts and ligands such as N^N and N^N^N. Their research has shown that by manipulating the steric and electronic effects of the ligands, their ethylene catalytic performance can be controlled, maintaining high catalytic activity while further enhancing thermal stability. This has garnered attention and recognition from international peers. Furthermore, the iron complex A developed by the inventors' research group exhibits extremely high ethylene oligomerization activity (up to 4.91×10 6 g(PE)(mol Fe) -1 h -1 ), and the α-olefins produced have high selectivity (>94%) and conform to the Schulz-Flory distribution (Organometallics 2006, 25, 666-677). Currently, this catalyst has been used in a pilot reaction for the preparation of 500 tons of α-olefins per year, and has received attention and recognition in the industrial field.

[0004] The pyridinediimine iron and cobalt complexes reported by the inventors' research group include B–E in Formula 1. Based on the classic pyridinediimine N^N^N iron / cobalt complex, the N-aryl group is modified by introducing sterically hindered diphenylmethyl or dibenzocycloheptyl groups at the 2- and / or 4-positions to enhance the catalytic activity and thermal stability of the catalyst system. Compared with complex B (Formula 1, Dalton Trans. 2013, 42, 9188–9197), complex C (Formula 1, Polym. Chem. 2012, 3, 787-793; Polymer 2012, 53, 130-137) introduced another diphenylmethyl group at the para position, and showed higher catalytic activity when MAO or MMAO was used as a co-catalyst; cobalt complex D (Formula 1, Sci China Chem 2016, 59, 1291-1300) did not show significant improvement in the activity and thermal stability of catalytic ethylene polymerization; cobalt complex E (Formula 1, Molecules 2019, 24, 2007) made further breakthroughs in thermal stability. When MAO was used as a co-catalyst, the catalytic activity could be maintained at 10 at the optimal reaction temperature of 60°C. 6 g(PE)(mol Co) -1 h -1 At the same level, the relative molecular weight is 8-70 kg·mol -1 These research results serve as a good reference for us to design catalysts with high activity and high thermal stability, and also lay a good foundation for further research.

[0005]

[0006] As a new type of olefin polymerization catalyst, late transition metal complexes still face difficulties in related basic research and constraints on promoting industrialization. For example, the thermal stability of late transition metal complexes is poor, which causes the properties of the resulting polymer to change with temperature, and places high demands on temperature control during the polymerization process. Therefore, in addition to improving preparation conditions and efficiency, how to obtain high-activity ethylene polymerization catalysts with better thermal stability to adapt to industrial production has become the core content of scholars' research and is also the key to whether industrialization can be promoted as soon as possible.

[0007] In view of this, the present invention is proposed. Summary of the Invention

[0008] The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art. The present invention provides a late transition metal iron-cobalt complex for preparing highly linear polyethylene, and a preparation method and application thereof.

[0009] In order to solve the above technical problems, the basic concept of the technical solution adopted by the present invention is:

[0010] The present invention provides a late transition metal iron-cobalt complex having a structure as shown in formula (I):

[0011]

[0012] Wherein, M is a metal, preferably a late transition metal, more preferably any one of iron, cobalt, nickel, and palladium, more preferably iron or cobalt;

[0013] Each X is the same or different and is independently selected from F, Cl, Br, I;

[0014] Each R 1 、R 2 、R 3 、R 4 、R 5 、R 6 The same or different, each independently selected from one or more R a The following groups substituted: H, C 1-6 Alkyl, C 1-6 Alkoxy, C 3-12 Cycloalkyl, 3-10 membered heterocyclic group, C 3-10 Cycloalkyloxy, C 6-20 Aryl, C 6-20 Aryloxy, C 6-20 Aryl C 1-6 Alkyl or di-C 6-20 Aryl C 1-6 alkyl;

[0015] Each R a The same or different, each independently selected from H, F, Cl, Br, I, C 1-6 Alkyl, C 1-6 Alkoxy, C 3-12 Cycloalkyl, C 3-10 Cycloalkoxy, C 6-20 Aryl, C 6-20 Aryloxy or C 6-20 Aryl C 1-6 alkyl;

[0016] The heteroatom N can be replaced by O or S;

[0017] Preferably, each R 1 The same or different, each independently selected from H or C 1-6 Alkyl; each R 2 、R 6 The same or different, each independently selected from H or C 1-6 Alkyl; each R 3 、R 4 、R 5 The same or different, each independently selected from the following groups: H, C3-12 Cycloalkyl, 3-10 membered heterocyclic group, C 6-20 Aryl, C 6-20 Aryloxy, C 6-20 Aryl C 1-6 Alkyl or di-C 6-20 Aryl C 1-6 alkyl;

[0018] Further preferably, each R 1 are all selected from methyl; each R 2 、R 6 are all selected from H; each R 3 、R 4 、R 5 the same or different, each independently selected from H, cyclopentyl, cyclohexyl, cyclooctyl, cyclododecyl, benzhydryl;

[0019] More preferably, each R 1 are all methyl; each R 3 are all diphenylmethyl; each R 4 are the same and are selected from cyclopentyl, cyclohexyl, cyclooctyl or cyclododecyl; each R 2 、R 5 、R 6 Both are H.

[0020] In some embodiments, the late transition metal complex represented by formula (I) of the present invention includes but is not limited to complexes having the following group definitions:

[0021] Complex Fe-1: R 1 =Me, R 3 =CHPh2,R 4 =C5H9, M=Fe, X is selected from Cl, and the other groups are H;

[0022] Complex Fe-2: R 1 =Me, R 3 =CHPh2,R 4 =C6H 11 , M=Fe, X is selected from Cl, and other groups are H;

[0023] Complex Fe-3: R 1 =Me, R 3 =CHPh2,R 4 =C8H 15 , M=Fe, X is selected from Cl, and other groups are H;

[0024] Complex Fe-4: R 1 =Me, R 3 =CHPh2,R 4 =C12 H 23 , M=Fe, X is selected from Cl, and other groups are H;

[0025] Complex Co-1: R 1 =Me, R 3 =CHPh2,R 4 =C5H9, M=Co, X is selected from Cl, and the other groups are H;

[0026] Complex Co-2: R 1 =Me, R 3 =CHPh2,R 4 =C6H 11 , M=Co, X is selected from Cl, and other groups are H;

[0027] Complex Co-3: R 1 =Me, R 3 =CHPh2,R 4 =C8H 15 , M=Co, X is selected from Cl, and other groups are H;

[0028] Complex Co-4: R 1 =Me, R 3 =CHPh2,R 4 =C 12 H 23 , M=Co, X is selected from Cl, and other groups are H;

[0029] The present invention also provides a ligand compound having a structure as shown in formula (II) or formula (III);

[0030]

[0031]

[0032] Wherein, R in the formula (II) 1 、R 2 、R 3 、R 4 、R 5 、R 6 and R in the above formula (I) 1 、R 2 、R 3 、R 4 、R 5 、R 6 Same; R in the formula (III) 1 、R 2 、R 6 and R in the above formula (I) 1 、R 2、R 6 same;

[0033] In some embodiments, the ligand compound represented by formula (II) of the present invention includes but is not limited to a complex having the following group definitions:

[0034] Ligand L1: R 1 =Me, R 3 =CHPh2,R 4 =C5H9, other groups are H;

[0035] Ligand L2: R 1 =Me, R 3 =CHPh2,R 4 =C6H 11 , other groups are H;

[0036] Ligand L3: R 1 =Me, R 3 =CHPh2,R 4 =C8H 15 , other groups are H;

[0037] Ligand L4: R 1 =Me, R 3 =CHPh2,R 4 =C 12 H 23 , other groups are H;

[0038] Preferably, the ligand compound of formula (III) includes a compound having a structure as shown in formula (III-1):

[0039]

[0040] The present invention also provides a method for preparing the late transition metal complex as described above, wherein the late transition metal complex is prepared by complexing the ligand compound of formula (II) and compound MX2;

[0041] Wherein, M and X in the compound MX2 are the same as M and X in the formula (I); preferably, the compound MX2 is selected from at least one of an iron- or cobalt-containing halide, a hydrate or a solvate of an iron- or cobalt-containing halide; preferably, the compound MX2 is selected from at least one of FeCl2, FeCl2·4H2O, CoCl2 or CoCl2·6H2O;

[0042] Preferably, the preparation method of the late transition metal complex comprises step S1: mixing the ligand compound of formula (II) and the compound MX2 in an organic solvent A at a molar ratio of (1-1.5):1, and reacting at 10-35° C. for 8-16 hours to obtain the late transition metal complex;

[0043] Preferably, the complexation reaction is carried out under anaerobic conditions; the complexation reaction time is 11 to 13 hours; the molar ratio of the ligand compound of formula (II) to the compound MX2 is (1 to 1.3):1; the organic solvent A is selected from at least one of an alcohol solvent and a halogenated alkane solvent;

[0044] Preferably, the complexation reaction is carried out under an inert gas; preferably, the complexation reaction is carried out under nitrogen;

[0045] Preferably, the molar ratio of the ligand compound of formula (II) to the compound MX2 is 1.1:1; and the organic solvent A is selected from at least one of anhydrous ethanol and dichloromethane.

[0046] In some embodiments, the method for preparing the late transition metal complex further comprises: purifying the late transition metal complex prepared in step S1, wherein the purification comprises the following steps:

[0047] Step S2-1: extracting the solvent from the late transition metal complex prepared in step S1, and then dissolving it in an organic solvent B for precipitation to obtain a precipitation system;

[0048] Step S2-2: performing solid-liquid separation on the precipitate system obtained in step S2-1, washing the solid phase with an organic solvent B and drying the solid phase to obtain a purified late transition metal complex;

[0049] Preferably, in step S2-1, a vacuum pump is used to extract the solvent from the late transition metal complex; the organic solvent B in steps S2-1 and S2-2 is an anhydrous organic solvent, and the anhydrous organic solvent is at least one of anhydrous ether and anhydrous n-hexane.

[0050] The present invention also provides a method for preparing the ligand compound as described above:

[0051] The ligand compound of formula (II) is prepared by condensing the ligand compound of formula (III) with an aniline compound of formula (IV-1);

[0052]

[0053] Wherein, R in the formula (IV-1) 3 、R 4、R 5 and R in the formula (I) 3 、R 4 、R 5 same;

[0054] Preferably, the preparation method of the ligand compound of formula (II) comprises the following steps:

[0055] Step S1: The ligand compound of formula (III) and the aniline compound of formula (IV-1) are mixed in an organic solvent C at a molar ratio of (1-2):1, and reacted under heating reflux and catalysis of an organic acid a for 6-12 hours to obtain the ligand compound of formula (II);

[0056] Preferably, the molar ratio of the ligand compound of formula (III) to the aniline compound of formula (IV-1) is 1.5:1; the condensation reaction time is 8 to 10 hours;

[0057] Preferably, the organic acid a is selected from at least one of formic acid, acetic acid, and p-toluenesulfonic acid; more preferably, the organic acid a is selected from p-toluenesulfonic acid;

[0058] Preferably, the organic solvent C is an aromatic hydrocarbon solvent; more preferably, the organic solvent C is toluene;

[0059] Preferably, the method for preparing the ligand compound of formula (II) further comprises: purifying the ligand compound of formula (II) prepared in step S1, wherein the purification process comprises the following steps:

[0060] Step S2-1: dissolving the ligand compound of formula (II) prepared in step S1 in dichloromethane to obtain a solution;

[0061] Step S2-2: using basic alumina for support, performing column chromatography on a silica basic alumina column, eluting the solution obtained in step S2-1 with a mixed solvent of petroleum ether and ethyl acetate as an eluent, and detecting the eluted fraction by thin layer chromatography;

[0062] Step S2-3: The solvent is removed again to obtain a purified ligand compound of formula (II).

[0063] The present invention also provides a method for preparing the ligand compound as described above:

[0064] The ligand compound of formula (III) is prepared by a substitution reaction between a 2,6-diacetylpyridine compound of formula (V) and an aniline compound of formula (IV-2);

[0065]

[0066] Wherein, R in the formula (V) 6 and R in the formula (I) 6 Same; R in the formula (IV-2) 1 、R 2 and R in the formula (I) 1 、R 2 same;

[0067] Preferably, the preparation method of the ligand compound of formula (III) comprises the following steps:

[0068] Step (1): The 2,6-diacetylpyridine compound of formula (V) and the aniline compound of formula (IV-2) are mixed in an organic solvent D at a molar ratio of 1: (1 to 1.3), and reacted at 10 to 35° C. for 12 to 36 hours under the catalysis of an organic acid b to obtain the ligand compound of formula (III);

[0069] Preferably, the molar ratio of the 2,6-diacetylpyridine compound of formula (V) to the aniline compound of formula (IV-2) is 1:1; the substitution reaction time is 15 to 20 hours;

[0070] Preferably, the organic solvent D is an alcohol solvent, more preferably, the organic solvent D is methanol;

[0071] Preferably, the organic acid b is selected from at least one of formic acid, acetic acid, and p-toluenesulfonic acid; more preferably, the organic acid is formic acid;

[0072] Preferably, the method for preparing the ligand compound of formula (III) further comprises: purifying the ligand compound of formula (III) prepared in step (1), wherein the purification process comprises the following steps:

[0073] Step (2): The ligand compound of formula (III) prepared in step (1) is subjected to solid-liquid separation, and the solid phase is washed with anhydrous methanol and dried to obtain a purified ligand compound of formula (III).

[0074] The present invention also provides an application of the ligand compound as described above, including the application of the ligand compound of formula (II) in the preparation of the late transition metal complex and the application of the ligand compound of formula (III) in the preparation of the ligand compound of formula (II).

[0075] The present invention also provides a use of the late transition metal complex as described above in catalyzing olefin polymerization reactions; preferably, in catalyzing ethylene polymerization reactions.

[0076] The present invention also provides a catalyst composition comprising: a main catalyst and a co-catalyst, wherein the main catalyst is the late transition metal complex described above, and the co-catalyst is at least one selected from aluminoxane, alkyl aluminum and alkyl aluminum chloride;

[0077] Preferably, the molar ratio of the metal Al in the co-catalyst to the central metal M in the late transition metal complex is (500-4000):1; further preferably, the molar ratio is (1000-3500):1; more preferably, the molar ratio is selected from any one of 1000:1, 1500:1, 1750:1, 2000:1, 2250:1, 2500:1, 2750:1, and 3250:1;

[0078] Preferably, the aluminoxane is selected from at least one of methylaluminoxane and triisobutylaluminum-modified methylaluminoxane; the alkylaluminum is selected from at least one of diethylaluminum and dimethylaluminum; the alkylaluminum chloride is selected from at least one of diethylaluminum chloride and dimethylaluminum chloride;

[0079] Preferably, when the co-catalyst is methylaluminoxane, the molar ratio of the metal Al in the methylaluminoxane to the central metal M in the late transition metal complex is (2000-3000):1; preferably, the molar ratio is 2500:1;

[0080] Preferably, when the cocatalyst is triisobutylaluminum-modified methylaluminoxane, the molar ratio of the metal Al in the triisobutylaluminum-modified methylaluminoxane to the central metal M in the late transition metal complex is (1750-2750):1; preferably, the molar ratio is 2250:1;

[0081] Preferably, the alkyl group in the alkylaluminum and alkylaluminum chloride is selected from alkyl groups having 1 to 3 carbon atoms.

[0082] The present invention also provides a method for preparing polyolefins, comprising: catalyzing an olefin polymerization reaction under the action of the catalyst composition described above to obtain the olefin polymer;

[0083] Preferably, the polymerization reaction temperature is 30 to 100° C.; preferably, the polymerization reaction temperature is 40 to 90° C.; preferably, the polymerization reaction temperature is 40° C., 50° C., 60° C., 70° C., 80° C. or 90° C.;

[0084] Preferably, the reaction time of the polymerization reaction is 5 to 60 minutes; preferably, the reaction time of the polymerization reaction is 20 to 40 minutes; preferably, the reaction time of the polymerization reaction is 30 minutes;

[0085] Preferably, the polymerization reaction pressure is 0.5 to 10 atm; preferably, the polymerization reaction pressure is 10 atm;

[0086] Preferably, the polymerization reaction is carried out under an ethylene atmosphere, and the catalyst composition is dissolved in an organic solvent E; the organic solvent E is selected from at least one of toluene, o-xylene, dichloromethane, ethanol, tetrahydrofuran, hexane or cyclohexane.

[0087] After adopting the above technical solution, the present invention has the following beneficial effects compared with the prior art:

[0088] 1. The present invention provides a class of late transition metal complexes that introduce bulky cycloalkyl and diphenylmethyl groups into the N-aryl group to form an asymmetric diiminopyridine intermediate and a late transition metal complex. Compared to the previous method of controlling steric hindrance by placing methyl, ethyl, and isopropyl groups at the ortho position of one aniline, the present invention further controls steric hindrance by introducing cyclopentyl, cyclohexyl, cyclooctyl, and cyclododecyl groups of varying carbon numbers at the ortho position of the bulky sterically hindered aniline substituent, thereby regulating the chemical environment of the central metal. Furthermore, due to the steric hindrance of the ortho diphenylmethyl and cycloalkyl groups, the plane of the aryl imine is essentially perpendicular to the coordination plane, effectively protecting the metal active center. Therefore, the complexes described in the present invention are highly active and stable.

[0089] 2. The preparation process of the late transition metal complex provided by the present invention has the advantages of mild reaction conditions, short cycle, and simple operating conditions.

[0090] 3. The use of the late transition metal complex provided by the present invention can be used as a catalyst in ethylene polymerization reaction, has high reaction activity, and has a strong control performance on the molecular weight of polyethylene; by changing its metal center, the molecular weight distribution of polyethylene can be controlled, and the molecular weight distribution of polyethylene catalyzed by the iron complex has a wide distribution (M w / M n :2.0–10.7); while the molecular weight of polyethylene obtained from cobalt complexes (except Co-4) has a narrow distribution (M w / M n : 1.6–2.2), highly linear polyethylene can be prepared.

[0091] 4. The late transition metal complex provided by the present invention has the following structural characteristics as a catalyst: the aniline on either side of the metal center is asymmetric, with the 2,4 positions of the aniline on one side being sterically hindered by a diphenylmethyl substituent and a cycloalkyl group at the 6 position, while the 2,4,6 positions of the aniline on the other side are methyl groups. The synergistic effect of these structures favorably stabilizes the positive charge of the central metal, exhibiting Lewis acidity and increasing the probability of ethylene insertion. The asymmetric diiminopyridine structure can fully utilize the sterically hindered ortho-cycloalkyl group, hindering the deactivation of the active center caused by chain transfer to the cocatalyst during the polymerization process, thereby giving the system higher catalytic activity and stability. For example, when methylaluminoxane (MAO) or triisobutylaluminum-modified methylaluminoxane (MMAO) is used as a cocatalyst, the activity of the cobalt complex in catalyzing ethylene polymerization at 60°C can reach 1.03×10 7 g(PE)(mol Co) -1 h -1 ; The iron complex showed 2.56×10 7 g(PE)(mol Fe) -1 h -1 The catalytic activity of the polyethylene prepared by this type of catalyst is M w 11.3–150.9 kg·mol -1 It fluctuates between the two levels and can be used to prepare special high-end commercial polyethylene products.

[0092] 5. When the late transition metal complexes provided by the present invention are used as catalysts, the number of carbon atoms in the ortho-cycloalkyl group significantly affects the catalytic activity of the complexes. When the ortho-cycloalkyl group is cyclopentyl or cyclohexyl, the catalytic activity of the complexes is significantly better than when the ortho-cycloalkyl group is cyclooctyl or cyclododecyl.

[0093] 6. The late transition metal complexes provided by the present invention exhibit extremely high thermal stability in catalyzing ethylene polymerization. For the iron complex, the catalytic activity can still be maintained at 1.14×10 7 g(PE)(mol Fe) -1 h -1 , which is in line with the operating temperature of industrial production and has the prospect of further industrial application.

[0094] 7. The polymerization method for preparing polyethylene provided by the present invention is simple to operate, the reaction conditions are easy to control, and the obtained product has a controllable molecular weight and melting point (melting point is greater than 120°C). For the cobalt complex, it can catalyze ethylene polymerization to obtain polyethylene products with narrow molecular weight distribution (PDI value <2.0), with a molecular weight range of 10–60 kg·mol -1, showing the characteristics of highly linear end group saturation, can be used as films, fibers and various types of pipes, etc., and shows potential applications in the production of long-chain copolymers, functional polymers and coating materials.

[0095] Definition and explanation of terms:

[0096] The term "C 1-6 The term "alkyl" refers to a straight or branched chain alkyl group having 1 to 6 carbon atoms, such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, sec-butyl, pentyl, and neopentyl.

[0097] The term "C 1-6 "Alkoxy" is understood to mean preferably a linear or branched saturated monovalent hydrocarbon radical of the formula -O-alkyl, wherein the term "C 1-6 "Alkyl" has the above definition, for example, methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, sec-butoxy, tert-butoxy, pentyloxy, isopentyloxy, hexyloxy or its isomers. In particular, "alkoxy" is "C 1-4 Alkoxy", "C 1-3 Alkoxy", methoxy, ethoxy or propoxy, preferably methoxy, ethoxy or propoxy. More preferably "C 1-2 "alkoxy", especially methoxy or ethoxy.

[0098] The term "C 3-12 "Cycloalkyl" is understood to mean preferably a linear or branched saturated monovalent monocyclic hydrocarbon ring containing, for example, 3, 4, 5, 6, 7, 8 or 12 carbon atoms. 3-8 Cycloalkyl is, for example, a monocyclic hydrocarbon ring, such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl or cyclooctyl. In particular, the cycloalkyl is C 4-6 Cycloalkyl, C 5-6 Cycloalkyl or cyclohexyl. For example, the term "C 3-6 "Cycloalkyl" is understood to be preferably a saturated monovalent monocyclic hydrocarbon ring containing, for example, 3, 4, 5 or 6 carbon atoms. In particular, C 3-6 Cycloalkyl is a monocyclic hydrocarbon ring, for example cyclopropyl, cyclobutyl, cyclopentyl or cyclohexyl.

[0099] The term "C 3-10 "Cycloalkyloxy" is understood to mean preferably a radical of the formula -O-cycloalkyl, in which the term "C 3-10 "Cycloalkyl" has the same meaning as above.

[0100] The term "3-10 membered heterocyclyl" means a saturated monovalent monocyclic or bicyclic hydrocarbon ring containing 1-5, preferably 1-3, heteroatoms selected from N, O and S. The heterocyclyl may be attached to the rest of the molecule via any one of the carbon atoms or the nitrogen atom (if present). In particular, the heterocyclyl may include, but is not limited to, a 4-membered ring such as azetidinyl, oxetanyl, a 5-membered ring such as tetrahydrofuranyl, dioxolyl, pyrrolidinyl, imidazolidinyl, pyrazolidinyl, pyrrolinyl, or a 6-membered ring such as tetrahydropyranyl, piperidinyl, morpholinyl, dithianyl, thiomorpholinyl, piperazinyl or trithianyl, or a 7-membered ring such as diazepanyl. Optionally, the heterocyclyl may be benzo-fused. The heterocyclic group may be bicyclic, for example, but not limited to, a 5,5-membered ring such as a hexahydrocyclopenta[c]pyrrol-2(1H)-yl ring, or a 5,6-membered bicyclic ring such as a hexahydropyrrolo[1,2-a]pyrazin-2(1H)-yl ring. The ring containing the nitrogen atom may be partially unsaturated, i.e., it may contain one or more double bonds, for example, but not limited to, 2,5-dihydro-1H-pyrrolyl, 4H-[1,3,4]thiadiazinyl, 4,5-dihydrooxazolyl or 4H-[1,4]thiazinyl, or it may be benzo-fused, for example, but not limited to, dihydroisoquinolinyl. According to the present invention, the heterocyclic group is non-aromatic. The term "C 6-20 "Aryl" is understood to mean preferably a monovalent aromatic or partially aromatic monocyclic, bicyclic or tricyclic hydrocarbon ring having 6 to 20 carbon atoms, preferably "C 6-14 Aryl". The term "C 6-14 The term "aryl" is understood to mean preferably a monovalent aromatic or partially aromatic monocyclic, bicyclic or tricyclic hydrocarbon ring having 6, 7, 8, 9, 10, 11, 12, 13 or 14 carbon atoms ("C6-14 aryl"), in particular a ring having 6 carbon atoms ("C6 aryl"), for example phenyl or biphenyl, or a ring having 9 carbon atoms ("C9 aryl"), for example indanyl or indenyl, or a ring having 10 carbon atoms ("C 10 aryl) such as tetrahydronaphthyl, dihydronaphthyl or naphthyl, or a ring having 13 carbon atoms ("C 13 aryl), such as fluorenyl, or a ring having 14 carbon atoms ("C 14 "aryl"), for example anthracenyl.

[0101] The term "C 6-20 "Aryloxy" is understood to mean preferably a radical of the formula -O-aryl or -O-heteroaryl, in which the term "C 6-20 "Aryl" or "heteroaryl" has the above definition.

[0102] Examples of monocyclic 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 benzo derivatives thereof, such as benzofuranyl, benzothienyl, benzoxazolyl, benzisoxazolyl, benzimidazolyl, benzotriazolyl, indazolyl, indole, benzothiophene ... Indole, isoindole, etc.; or pyridyl, pyridazinyl, pyrimidinyl, pyrazinyl, triazinyl, etc., and benzo derivatives thereof, such as quinolyl, quinazolinyl, isoquinolyl, etc.; or acinyl, indolizinyl, purinyl, etc. and benzo derivatives thereof; or cinnolinyl, phthalazinyl, quinazolinyl, quinoxalinyl, naphthyridinyl, pteridinyl, carbazolyl, acridinyl, phenazinyl, phenothiazinyl, phenoxazinyl, etc.

[0103] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0104] Figure 1 This is a reaction flow chart for preparing the complexes of Examples 1-13 of the present invention.

[0105] Figure 2 Schematic diagram of the crystal structure of complex Co-2 prepared in Example 11.

[0106] Figure 3 These are the high-temperature H-NMR spectrum and high-temperature C-NMR spectrum of the polymer prepared in Example 26(g). DETAILED DESCRIPTION

[0107] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments are clearly and completely described below. It should be understood that the following embodiments are only exemplary illustrations and explanations of the present invention and should not be construed as limiting the scope of protection of the present invention. All technologies implemented based on the above content of the present invention are included in the scope of protection intended by the present invention.

[0108] Unless otherwise specified, the raw materials and reagents used in the following examples can be obtained from commercial sources or prepared by known methods. The experimental methods used in the following examples, unless otherwise specified, are conventional methods known in the art. The concentrations in the following examples, unless otherwise specified, are all molar concentrations.

[0109] Methylaluminoxane (MAO) and triisobutylaluminum-modified methylaluminoxane (MMAO) used in the examples were purchased from AkzoNobel, USA. In the following examples, Al / Fe is defined as the molar ratio of the metallic Al in the cocatalyst MAO or MMAO to the Fe in the metal complex, and Al / Co is defined as the molar ratio of the metallic Al in the cocatalyst MAO or MMAO to the Co in the metal complex, rather than the molar ratio of aluminum to Fe or aluminum to Co.

[0110] The molecular weight (M) of the polymers obtained in the ethylene polymerization examples 14-29 w ) were determined using conventional high-temperature GPC methods, and the melting point (T m ) were determined according to the conventional DSC method, and the polymerization activity of the polymers were calculated according to the following formula: polymerization activity = polymer yield / (catalyst amount*polymerization time).

[0111] The identities of all the synthesized compounds described below were confirmed by infrared and elemental analyses.

[0112] Example 1

[0113] In this embodiment, 2(1-(2,4,6-trimethylanilino)ethyl)-6-acetylpyridine having a structure shown in formula (III-1) was prepared.

[0114] Under an inert atmosphere (nitrogen), 1.63 g (10.0 mmol) of 2,6-diacetylpyridine and 1.35 g (10.0 mmol) of 2,4,6-trimethylaniline were weighed and added to a reaction flask. 5 mL of formic acid and 50 mL of anhydrous methanol were then added. The mixture was stirred at room temperature for 18 hours. A solid product precipitated. The precipitate was collected by filtration after solid-liquid separation and then washed with anhydrous methanol (3 × 5 mL). After vacuum drying, 1.82 g of a yellow powder, the compound represented by formula (III-1), was obtained in a 65% yield.

[0115] The structural confirmation data are as follows:

[0116] 1 H NMR (400MHz, CDCl3, TMS): δ8.56 (d, J = 8.0Hz, 1H), 8.12 (d, J = 7.6Hz, 1H), 7.93 (t, J=7.8Hz,1H),6.90(s,2H),2.79(s,3H),2.30(s,3H),2.23(s,3H,),2.00(s,6H).

[0117] 13C NMR (100MHz, CDCl3, TMS): δ200.1,166.8,155.7,152.5,146.0,137.2,132.4,128.6,125.1,124.5,122.5,25.6,20.7,17.8,16.2.

[0118] FT-IR (cm -1 ):2942(w),2910(w),2852(w),1695(s),1633(m),1575(w),1472(w),1353(s),1298(m),1243 (m),1213(m),1117(m),1074(m),993(w),951(m),849(s),821(vs),790(m),737(m),686(w).

[0119] Elemental analysis: C 18 H 20 N2O (280.37) theoretical values: C, 77.11; H, 7.19; N, 9.99%. Found values: C, 69.90; H, 7.47; N, 9.63%.

[0120] Example 2

[0121] In this embodiment, 2(1-(2,4,6-trimethylanilino)ethyl)-6(1-(2,4-bis(diphenylmethyl)-6-cyclopentylanilino)ethyl)pyridine (ligand L1) having a structure as shown in formula (II) was prepared.

[0122] 0.84 g (3.0 mmol) of 2-(1-(2,4,6-trimethylanilino)ethyl)-6-acetylpyridine (the compound represented by formula (III-1)) and 0.99 g (2.0 mmol) of 2,4-bis(diphenylmethyl)-6-cyclopentylaniline were weighed and added to a reaction flask. A catalytic amount of p-toluenesulfonic acid (15%) was then added to the flask, followed by addition of 50 mL of toluene solvent. The reaction mixture was heated under reflux for 8 h. After completion of the reaction as determined by TLC, the mixture was cooled to room temperature, and the volatiles were evaporated under reduced pressure. The resulting crude residual solid was then dissolved in dichloromethane, supported on basic alumina, and eluted by column chromatography on a silica alkaline alumina column using a mixture of petroleum ether and ethyl acetate (200:1 v / v). The third fraction was collected and the solvent removed to yield 0.42 g of a yellow powder, ligand L1, in a 28% yield.

[0123] The structural confirmation data are as follows:

[0124] 1H NMR (400MHz, CDCl3, TMS): δ8.43(d,J=8.0Hz,1H),8.33(d,J=7.2Hz,1H),7.88(t,J=8.0Hz,1H),7.24–6.89(m,23H),6.58(s,1H),5.42(s),5.35(s,1 H),2.72(m,1H),2.30(m,3H),2.16(m,3H,),2.05(m,3H),2.00(m,3H),1.9 4(m,1H),1.79(m,1H),1.63(m,1H),1.61(m,3H),1.45(m,1H),1.26(m,1H).

[0125] 13 C NMR (100MHz, CDCl3, TMS): δ168.7,155.2,146.2,142.7,136.6,133.8,132.2,129.8,129.3,128.6,128.5,128.1,1 28.0,127.9,126.0,125.8,125.6,125.3,122.1,56.6,52.3,39.9,34.4,33.9,25.7,25.6,20.7,17.8,17.0,16.3.

[0126] FT-IR (cm -1 ):3060(w),3024(w),2959(m),2916(m),2864(m),1640(s),1602(w),1566(w),1490(w ),1450(s),1362(m),1259(s),1097(s),1076(s),1021(s),797(vs),743(s),697(vs).

[0127] Elemental analysis: C 55 H 53 N3 (756.05) theoretical values: C, 87.38; H, 7.07; N, 5.56%. Found values: C, 81.90; H, 7.47; N, 5.56%.

[0128] Example 3

[0129] In this embodiment, 2(1-(2,4,6-trimethylanilino)ethyl)-6(1-(2,4-bis(diphenylmethyl)-6-cyclohexylanilino)ethyl)pyridine (ligand L2) having a structure as shown in formula (II) was prepared.

[0130] 0.84 g (3.0 mmol) of 2-(1-(2,4,6-trimethylanilino)ethyl)-6-acetylpyridine (the compound represented by formula (III-1)) and 1.01 g (2.0 mmol) of 2,4-bis(diphenylmethyl)-6-cyclohexylaniline were weighed and added to a reaction flask. A catalyst-equivalent amount of p-toluenesulfonic acid (15%) was then added to the flask, followed by addition of 50 mL of toluene solvent. The reaction mixture was heated under reflux for 8 h. After completion of the reaction as determined by TLC, the mixture was cooled to room temperature, and the volatiles were evaporated under reduced pressure. The resulting crude residual solid was then dissolved in dichloromethane, supported on basic alumina, and eluted by column chromatography on a silica alkaline alumina column using a mixture of petroleum ether and ethyl acetate (200:1 v / v). The third fraction was collected and the solvent removed to yield 0.59 g of a yellow powder, ligand L2, in a 38% yield.

[0131] The structural confirmation data are as follows:

[0132] 1 H NMR (400MHz, CDCl3, TMS): δ8.45(d,J=8.0Hz,1H),8.32(d,J=7.6Hz,1H),7.89(t,J=8.0Hz,1H),7.24–6.88(m,23H),6.58(s,1H),5.42(s,1H),5 .35(s,1H),2.30(m,3H),2.24(m,1H),2.17(m,3H),2.05(m,3H),2.02(m ,3H),1.88(m,1H),1.67(m,4H),1.59(m,3H),1.13(m,1H),1.09(m,4H).

[0133] 13 C NMR (100MHz, CDCl3, TMS): δ168.6,167.5,155.2,146.2,144.7,143.7,142.7,137.9,136.6,1 32.4,129.4,128.1,125.9,122.1,56.6,52.4,38.8,33.9,32.9,27.1,26.1,20.7,17.9,16.3.

[0134] FT-IR (cm -1 ):3057(w),3027(w),2923(m),2850(m),1637(s),1602(m),1566(w),1489(w),14 48(s),1362(m),1260(s),1097(s),1075(s),1026(s),800(s),742(s),697(vs).

[0135] Elemental analysis: C 56 H 55 N3 (770.08) theoretical values: C, 87.34; H, 7.20; N, 5.46%. Found values: C, 81.71; H, 7.53; N, 5.69%.

[0136] Example 4

[0137] In this embodiment, 2(1-(2,4,6-trimethylanilino)ethyl)-6(1-(2,4-bis(diphenylmethyl)-6-cyclooctylanilino)ethyl)pyridine (ligand L3) having a structure as shown in formula (II) was prepared.

[0138] 0.84 g (3.0 mmol) of 2-(1-(2,4,6-trimethylanilino)ethyl)-6-acetylpyridine (the compound represented by formula (III-1)) and 1.07 g (2.0 mmol) of 2,4-bis(diphenylmethyl)-6-cyclooctylaniline were weighed and added to a reaction flask. A catalytic amount of p-toluenesulfonic acid (15%) was then added to the flask, followed by addition of 50 mL of toluene solvent. The reaction mixture was heated under reflux for 8 h. After completion of the reaction as determined by TLC, the mixture was cooled to room temperature, and the volatiles were evaporated under reduced pressure. The crude residual solid was then dissolved in dichloromethane, supported on basic alumina, and eluted by column chromatography on a silica alkaline alumina column using a mixture of petroleum ether and ethyl acetate (200:1 v / v). The third fraction was collected and the solvent removed to yield 0.67 g of a yellow powder, ligand L3, in a 42% yield.

[0139] The structural confirmation data are as follows:

[0140] 1 H NMR (400MHz, CDCl3, TMS): δ8.43(d,J=7.6Hz,1H),8.30(d,J=7.6Hz,1H),7.88(t,J=8.0Hz,1H),7.12–6.88(m,23H),6.56(s,1H),5 .41(s,1H),5.36(s,1H),2.56(m,1H),2.30(m,3H),2.15(m,3H),2.05(m,3H),2.01(m,3H),1.65(m,4H),1.61(m,3H),1.43(m,10H).

[0141] 13C NMR (100MHz, CDCl3, TMS): δ168.9,167.5,155.4,155.2,146.3,144.8,143.7,142.8,137.2,132.3 ,129.3,128.5,127.8,126.0,125.8,122.0,56.6,52.4,37.1,34.5,33.3,26.9,26.6,25.8,20.7.

[0142] FT-IR (cm -1 ):3057(w),3025(w),2918(m),2854(m),1640(m),1600(w),1567(m),1491(m),1448(s),1340( m),1260(s),1212(s),1028(s),1115(s),1074(s),1026(s),852(m),812(s),740(s),696(vs).

[0143] Elemental analysis: C 58 H 59 N3 (798.13) theoretical values: C, 87.28; H, 7.45; N, 5.26%. Found values: C, 85.16; H, 7.40; N, 5.07%.

[0144] Example 5

[0145] In this embodiment, 2(1-(2,4,6-trimethylanilino)ethyl)-6(1-(2,4-bis(diphenylmethyl)-6-cyclododecylanilino)ethyl)pyridine (ligand L4) having a structure as shown in formula (II) was prepared.

[0146] 0.84 g (3.0 mmol) of 2-(1-(2,4,6-trimethylanilino)ethyl)-6-acetylpyridine (the compound represented by formula (III-1)) and 1.18 g (2.0 mmol) of 2,4-bis(diphenylmethyl)-6-cyclododecylaniline were weighed and added to a reaction flask. A catalytic amount of p-toluenesulfonic acid (15%) was then added to the flask, followed by addition of 50 mL of toluene solvent. The reaction mixture was heated under reflux for 8 h. After completion of the reaction as determined by TLC, the mixture was cooled to room temperature, and the volatiles were evaporated under reduced pressure. The resulting crude residual solid was then dissolved in dichloromethane, supported on basic alumina, and eluted by column chromatography on a silica alkaline alumina column using a mixture of petroleum ether and ethyl acetate (200:1 v / v). The third fraction was collected and the solvent removed to yield 0.51 g of a yellow powder, ligand L4, in a 30% yield.

[0147] The structural confirmation data are as follows:

[0148] 1 H NMR (400MHz, CDCl3, TMS): δ8.41(d,J=8.0Hz,1H),8.09(d,J=8.0Hz,1H),7.89(t,J=8.0Hz,1H),7.23–6.91(m,23H),6.56(s,1H),5 .42(s,1H),5.32(s,1H),2.70(m,3H),2.54(m,1H),2.21(m,3H),2.17(m,6H),1.65(m,4H),1.63(m,3H),1.21(m,10H),0.87(m,8H).

[0149] 13 C NMR (100MHz, CDCl3, TMS): δ168.1,164.3,155.7,155.3,146.4,144.7,143.7,142.7,138.0,136.9,129.8,1 28.5,128.0,127.8,126.2,126.0,125.8,124.6,56.5,52.5,32.4,31.1,25.5,24.7,24.6,23.4,23.0,22.8.

[0150] FT-IR (cm -1 ):3027(w),2927(m),2902(m),2852(m),1641(s),1599(m),1576(w),1492(m),14 46(s),1361(m),1261(m),1234(s),1113(s),1025(s),815(s),740(s),698(vs).

[0151] Elemental analysis: C 62 H 67 N3 (854.24) theoretical values: C, 87.17; H, 7.91; N, 4.92%. Exp. values: C, 85.33; H, 7.72; N, 4.87%.

[0152] Example 6

[0153] In this embodiment, a 2-(1-(2,4,6-trimethylanilino)ethyl)-6-(1-(2,4-bis(diphenylmethyl)-6-cyclopentylanilino)ethyl)pyridine ferrous chloride complex (complex Fe-1) having a structure as shown in formula (I) was prepared.

[0154] 0.151 g (0.20 mmol) of 2-(1-(2,4,6-trimethylanilino)ethyl)-6-(1-(2,4-bisbenzhydryl-6-cyclopentylanilino)ethyl)pyridine (ligand L1) and 0.036 g (0.18 mmol) of FeCl2·4H2O were placed in a reaction flask under a nitrogen atmosphere. 2 mL of dichloromethane and 8 mL of anhydrous ethanol were added. The reaction was stirred at room temperature for 12 h to ensure complete reaction. The volatiles were then evaporated under reduced pressure using a vacuum pump. A large amount of anhydrous ether was then added to produce a precipitate. The precipitate was separated by solid-liquid separation and collected by filtration. Finally, it was washed with anhydrous ether (3 × 5 mL). After vacuum drying, 0.121 g of a blue powder, the complex Fe-1, was obtained, with a yield of 76%.

[0155] The structural confirmation data are as follows:

[0156] FT-IR (cm -1 ):3069(w),2955(m),2862(w),1626(m),1587(s),1494(s),1447(s),1370( s),1258(s),1214(s),1079(s),1029(s),851(m),811(s),748(m),700(vs).

[0157] Elemental analysis: C 55 H 53 Cl2FeN3 (882.80) theoretical values: C, 74.83; H, 6.05; N, 4.76%. Found values: C, 75.08; H, 6.06; N, 4.52%.

[0158] Example 7

[0159] In this embodiment, a 2-(1-(2,4,6-trimethylanilino)ethyl)-6-(1-(2,4-bis(diphenylmethyl)-6-cyclohexylanilino)ethyl)pyridine ferrous chloride complex (complex Fe-2) having a structure as shown in formula (I) was prepared.

[0160] 0.154 g (0.20 mmol) of 2-(1-(2,4,6-trimethylanilino)ethyl)-6-(1-(2,4-bisbenzhydryl-6-cyclohexylanilino)ethyl)pyridine (ligand L2) and 0.036 g (0.18 mmol) of FeCl2·4H2O were placed in a reaction flask under a nitrogen atmosphere. 2 mL of dichloromethane and 8 mL of anhydrous ethanol were added. The mixture was stirred at room temperature for 12 h to ensure complete reaction. The volatiles were then evaporated under reduced pressure using a vacuum pump. A large amount of anhydrous ether was added to produce a precipitate. The precipitate was separated by solid-liquid separation and collected by filtration. Finally, it was washed with anhydrous ether (3 × 5 mL). After vacuum drying, 0.108 g of a blue powder, the complex Fe-2, was obtained, with a yield of 67%.

[0161] The structural confirmation data are as follows:

[0162] FT-IR (cm -1 ):3088(w),3026(m),2917(m),2852(m),1628(m),1588(s),1475(s),1446(s),1 370(s),1261(s),1219(s),1154(w),1028(m),854(s),811(s),744(s),701(vs).

[0163] Elemental analysis: C 56 H 55 Cl2FeN3 (896.82) theoretical values: C, 75.00; H, 6.18; N, 4.69%. Found values: C, 74.75; H, 6.30; N, 4.32%.

[0164] Example 8

[0165] In this embodiment, a 2-(1-(2,4,6-trimethylanilino)ethyl)-6-(1-(2,4-bis(diphenylmethyl)-6-cyclooctylanilino)ethyl)pyridine ferrous chloride complex (complex Fe-3) having a structure as shown in formula (I) was prepared.

[0166] 0.159 g (0.20 mmol) of 2-(1-(2,4,6-trimethylanilino)ethyl)-6-(1-(2,4-bisbenzhydryl-6-cyclooctylanilino)ethyl)pyridine (ligand L3) and 0.036 g (0.18 mmol) of FeCl2·4H2O were placed in a reaction flask under a nitrogen atmosphere. 2 mL of dichloromethane and 8 mL of anhydrous ethanol were added. The mixture was stirred at room temperature for 12 h to ensure complete reaction. The volatiles were then evaporated under reduced pressure using a vacuum pump. A large amount of anhydrous ether was added to produce a precipitate. The precipitate was separated by solid-liquid separation and collected by filtration. Finally, it was washed with anhydrous ether (3 × 5 mL). After vacuum drying, 0.135 g of a blue powder, the complex Fe-3, was obtained, with a yield of 81%.

[0167] The structural confirmation data are as follows:

[0168] FT-IR (cm -1 ):3062(w),2914(m),2849(w),1609(m),1598(s),1581(s),1494(m),1447( s),1370(s),1264(s),1219(m),1028(m),855(s),811(s),746(s),701(vs)

[0169] Elemental analysis: C 58 H 59 Cl2FeN3 (924.88) theoretical value: 75.32; H, 6.43; N, 4.54%. Found value: C, 75.02; H, 6.06; N, 4.22%.

[0170] Example 9

[0171] In this embodiment, a 2-(1-(2,4,6-trimethylanilino)ethyl)-6-(1-(2,4-bis(diphenylmethyl)-6-cyclododecylanilino)ethyl)pyridine ferrous chloride complex (complex Fe-4) having a structure as shown in formula (I) was prepared.

[0172] 0.170 g (0.20 mmol) of 2-(1-(2,4,6-trimethylanilino)ethyl)-6-(1-(2,4-bisbenzhydryl-6-cyclododecylanilino)ethyl)pyridine (ligand L4) and 0.036 g (0.18 mmol) of FeCl2·4H2O were placed in a reaction flask under a nitrogen atmosphere. 2 mL of dichloromethane and 8 mL of anhydrous ethanol were added. The mixture was stirred at room temperature for 12 h to ensure complete reaction. The volatiles were then evaporated under reduced pressure using a vacuum pump. A large amount of anhydrous ether was added to produce a precipitate. The precipitate was separated by solid-liquid separation and collected by filtration. It was then washed with anhydrous ether (3 × 5 mL). After vacuum drying, 0.132 g of a blue powder, the complex Fe-4, was obtained, with a yield of 75%.

[0173] The structural confirmation data are as follows:

[0174] FT-IR (cm -1 ):3060(w),3028(w),2941(s),2855(m),1591(s),1495(s),1467(s),1447( s),1364(s),1246(s),1206(m),1029(m),908(w),803(s),748(s),698(vs)

[0175] Elemental analysis: C 62 H 67 Cl2FeN3 (980.98) theoretical values: C, 75.91; H, 6.88; N, 4.28%. Found values: C, 75.56; H, 6.49; N, 4.12%.

[0176] Example 10

[0177] In this embodiment, a 2-(1-(2,4,6-trimethylanilino)ethyl)-6-(1-(2,4-bis(diphenylmethyl)-6-cyclopentylanilino)ethyl)pyridine cobalt chloride complex (complex Co-1) having a structure as shown in formula (I) was prepared.

[0178] 0.151 g (0.20 mmol) of 2-(1-(2,4,6-trimethylanilino)ethyl)-6-(1-(2,4-bis(diphenylmethyl)-6-cyclopentylanilino)ethyl)pyridine (ligand L1) and 0.043 g (0.18 mmol) of CoCl2·6H2O were placed in a reaction flask under a nitrogen atmosphere. 2 mL of dichloromethane and 8 mL of anhydrous ethanol were added. The mixture was stirred at room temperature for 12 h to ensure complete reaction. The volatiles were then evaporated under reduced pressure using a vacuum pump. A large amount of anhydrous ether was added to produce a precipitate. The precipitate was separated by solid-liquid separation and collected by filtration. Finally, it was washed with anhydrous ether (3 × 5 mL). After vacuum drying, 0.143 g of a brown powder, complex Co-1, was obtained, with a yield of 90%.

[0179] The structural confirmation data are as follows:

[0180] FT-IR (cm -1 ):3089(w),2915(m),2857(w),1630(m),1589(s),1480(s),1374(s),1 260(s),1219(s),1064(vs),1029(s),854(s),814(s),746(m),652(s).

[0181] Elemental analysis: C 55 H 53 Cl2CoN3 (885.88) theoretical values: C, 74.57; H, 6.03; N, 4.74%. Found values: C, 74.38; H, 6.09; N, 5.04%.

[0182] Example 11

[0183] In this embodiment, a 2-(1-(2,4,6-trimethylanilino)ethyl)-6-(1-(2,4-bis(diphenylmethyl)-6-cyclohexylanilino)ethyl)pyridine cobalt chloride complex (complex Co-2) having a structure as shown in formula (I) was prepared.

[0184] 0.154 g (0.20 mmol) of 2-(1-(2,4,6-trimethylanilino)ethyl)-6-(1-(2,4-bisbenzhydryl-6-cyclohexylanilino)ethyl)pyridine (ligand L2) and 0.043 g (0.18 mmol) of CoCl2·6H2O were placed in a reaction flask under a nitrogen atmosphere. 2 mL of dichloromethane and 8 mL of anhydrous ethanol were added. The reaction was stirred at room temperature for 12 h to ensure complete reaction. The volatiles were then evaporated under reduced pressure using a vacuum pump. A large amount of anhydrous ether was added to produce a precipitate. The precipitate was separated by solid-liquid separation and collected by filtration. Finally, it was washed with anhydrous ether (3 × 5 mL). After vacuum drying, 0.133 g of a brown powder, complex Co-2, was obtained, with a yield of 82%.

[0185] The crystal structure diagram of the complex Co-2 is shown in Figure 2 shown.

[0186] As can be seen from the figure, the central metal Co of the complex Co-2 adopts a five-coordinated structure, connected to three nitrogen atoms N1, N2, N3 and two chlorine atoms Cl1, Cl2, respectively, forming a distorted square pyramid structure. The three nitrogen atoms and the Cl1 atom form the bottom of the square pyramid, and Cl2 occupies the top of the square pyramid. Due to the steric effect, the distance between the Co atom and the Cl2 atom at the top of the pyramid is about The distances between the substrate atoms and the Co atoms are N(1)–Co(1), N(3)–Co(1), N(2)–Co(1), and Cl(1)–Co(1) respectively. and

[0187] The structural confirmation data are as follows:

[0188] FT-IR (cm -1 ):2926(m),2852(w),2160(w),1978(w),1617(m),1583(m),1494(m),1450(m),1370(m),1 263(s),1222(m),1188(w),1080(m),1028(m),856(m),812(m),779(m),747(s),703(vs).

[0189] Elemental analysis: C 56 H 55 Cl2CoN3 (899.91) theoretical values: C, 74.74; H, 6.16; N, 4.67%. Found values: C, 74.45; H, 6.07; N, 4.45%.

[0190] Example 12

[0191] In this embodiment, a 2-(1-(2,4,6-trimethylanilino)ethyl)-6-(1-(2,4-bis(diphenylmethyl)-6-cyclooctylanilino)ethyl)pyridine cobalt chloride complex (complex Co-3) having a structure as shown in formula (I) was prepared.

[0192] 0.159 g (0.20 mmol) of 2-(1-(2,4,6-trimethylanilino)ethyl)-6-(1-(2,4-bis(diphenylmethyl)-6-cyclooctylanilino)ethyl)pyridine (ligand L3) and 0.043 g (0.18 mmol) of CoCl2·6H2O were placed in a reaction flask under a nitrogen atmosphere. 2 mL of dichloromethane and 8 mL of anhydrous ethanol were added. The mixture was stirred at room temperature for 12 h to ensure complete reaction. The volatiles were then evaporated under reduced pressure using a vacuum pump. A large amount of anhydrous ether was added to produce a precipitate. The precipitate was separated by solid-liquid separation and collected by filtration. Finally, it was washed with anhydrous ether (3 × 5 mL). After vacuum drying, 0.143 g of a brown powder, complex Co-3, was obtained, with a yield of 86%.

[0193] The structural confirmation data are as follows:

[0194] FT-IR (cm -1 ):3060(w),2913(m),2850(w),1582(s),1491(m),1447(s),1369(s),1262(s),1219(m),1028(s),854(s),811(s),746(s),701(s).

[0195] Elemental analysis: C 58 H 59 Cl2CoN3 (927.96) theoretical value: 75.07; H, 6.41; N, 4.53%. Found value: C, 75.29; H, 6.35; N, 4.39%.

[0196] Example 13

[0197] In this embodiment, a 2-(1-(2,4,6-trimethylanilino)ethyl)-6-(1-(2,4-bis(diphenylmethyl)-6-cyclododecylanilino)ethyl)pyridine cobalt chloride complex (complex Co-4) having a structure as shown in formula (I) was prepared.

[0198] 0.170 g (0.20 mmol) of 2-(1-(2,4,6-trimethylanilino)ethyl)-6-(1-(2,4-bisbenzhydryl-6-cyclododecylanilino)ethyl)pyridine (ligand L4) and 0.043 g (0.18 mmol) of CoCl2·6H2O were placed in a reaction flask under a nitrogen atmosphere. 2 mL of dichloromethane and 8 mL of anhydrous ethanol were added. The reaction was stirred at room temperature for 12 h to ensure complete reaction. The volatiles were evaporated under reduced pressure using a vacuum pump. A large amount of anhydrous ether was added to produce a precipitate. The precipitate was separated by solid-liquid separation and collected by filtration. Finally, it was washed with anhydrous ether (3 × 5 mL). After vacuum drying, 0.138 g of a brown powder, complex Co-4, was obtained, with a yield of 78%.

[0199] The structural confirmation data are as follows:

[0200] FT-IR (cm -1 ):3078(w),3036(w),2940(s),2855(m),1591(s),1492(s),1447(s),1 366(s),1244(s),1206(m),1029(m),907(w),802(s),747(s),698(vs).

[0201] Elemental analysis: C 62 H 67 Cl2CoN3 (984.07) theoretical values: C, 75.67; H, 6.86; N, 4.27%. Found values: C, 75.26; H, 6.95; N, 4.00%.

[0202] Example 14

[0203] In this embodiment, the main catalyst (complex Fe-1) and the co-catalyst (MMAO) jointly catalyze ethylene polymerization under high pressure:

[0204] (a) Under an ethylene atmosphere, 25 mL of a toluene solution of the primary catalyst Fe-1 (1 μmol) was injected into a 250 mL stainless steel autoclave equipped with a mechanical stirrer. Then, 25 mL of toluene and 1.0 mL of a 1.93 mol / L n-hexane solution of the cocatalyst MMAO were added. Further toluene was added to bring the total solvent volume to 100 mL. The Al / Fe ratio now equaled 2000:1. Mechanical stirring was initiated at 400 rpm. When the polymerization temperature reached 50°C, ethylene was added to the autoclave to initiate the polymerization reaction. The polymerization reaction was stirred at 50°C, maintaining an ethylene pressure of 10 atm, for 30 min. The reaction solution was neutralized with ethanol solution acidified with 10% hydrochloric acid to obtain a polymer precipitate, which was washed several times with ethanol and dried under vacuum at 60°C to constant weight. 4.7 g of polymer was weighed.

[0205] Polymerization activity: 9.4×10 6 g(PE)(mol Fe) -1 h -1 , the molecular weight of the obtained polymer M w =26.0 kg·mol -1 , molecular weight distribution M w / M n =7.5(M w is the weight average molecular weight of the polymer, M n is the number average molecular weight of the polymer, obtained by GPC test), polymer T m =129.0℃(T mis the melting temperature of the polymer, obtained by DSC testing).

[0206] (b) is basically the same as in Example (a), except that the polymerization temperature is 60°C. Polymerization activity: 1.32×10 7 g(PE)(mol Fe) -1 h -1 , polymer molecular weight M w =24.1 kg·mol -1 , molecular weight distribution M w / M n =3.9, polymer T m =131.2℃.

[0207] (c) is basically the same as in Example (a), except that the polymerization temperature is 70°C. Polymerization activity: 1.94×10 7 g(PE)(mol Fe) -1 h -1 , polymer molecular weight M w =23.4 kg·mol -1 , molecular weight distribution M w / M n =3.3, polymer T m =131.4℃.

[0208] (d) is basically the same as Example (a), except that the polymerization temperature is 80°C. Polymerization activity: 1.31×10 7 g(PE)(mol Fe) -1 h -1 , polymer molecular weight M w =22.8 kg·mol -1 , molecular weight distribution M w / M n =3.9, polymer T m =130.8℃.

[0209] (e) Same as Example (a), except that the polymerization temperature was 90°C. Polymerization activity: 1.14×10 7 g(PE)(mol Fe) -1 h -1 , polymer molecular weight M w =21.5 kg·mol -1 , molecular weight distribution M w / M n =3.0, polymer T m =131.0℃.

[0210] (f) Same as Example (c), except that 0.9 mL of MMAO (1.93 mol / L in n-hexane) was used to increase the Al / Fe ratio to 1750:1. Polymerization activity: 1.76 × 10 7 g(PE)(mol Fe) -1 h -1 , polymer molecular weight M w =24.3 kg·mol -1 , molecular weight distribution M w / M n =2.4, polymer T m =131.9℃.

[0211] (g) Same as Example (c), except that 1.2 mL of cocatalyst MMAO (1.93 mol / L in n-hexane) was used to adjust the Al / Fe ratio to 2250:1. Polymerization activity: 2.56 × 10 7 g(PE)(mol Fe) -1 h -1 , polymer molecular weight M w =23.8 kg·mol -1 , molecular weight distribution M w / M n =2.6, polymer T m =131.7℃.

[0212] (h) Same as Example (c), except that 1.3 mL of MMAO (1.93 mol / L in n-hexane) was used to make the Al / Fe ratio 2500:1. Polymerization activity: 2.16 × 10 7 g(PE)(mol Fe) -1 h -1 , polymer molecular weight M w =24.8 kg·mol -1 , molecular weight distribution M w / M n =3.5, polymer T m =131.2℃.

[0213] (i) Same as Example (c), except that 1.4 mL of MMAO (1.93 mol / L in n-hexane) was used to increase the Al / Fe ratio to 2750:1. Polymerization activity: 1.87 × 10 7 g(PE)(mol Fe) -1 h -1 , polymer molecular weight M w =19.1 kg·mol -1 , molecular weight distribution M w / M n=2.8, polymer T m =130.2℃.

[0214] Example 15

[0215] In this embodiment, the main catalyst (complex Fe-2) and the co-catalyst (MMAO) jointly catalyze ethylene polymerization under high pressure:

[0216] Basically the same as Example 14(g), except that the main catalyst is Fe-2. Polymerization activity: 2.82×10 7 g(PE)(molFe) -1 h -1 , polymer molecular weight M w =11.3 kg·mol -1 , molecular weight distribution M w / M n =2.0, polymer T m =130.2℃.

[0217] Example 16

[0218] In this embodiment, the main catalyst (complex Fe-3) and the co-catalyst (MMAO) jointly catalyze ethylene polymerization under high pressure:

[0219] Basically the same as Example 14(g), except that the main catalyst is Fe-3. Polymerization activity: 2.42×10 7 g(PE)(molFe) -1 h -1 , polymer molecular weight M w =24.1 kg·mol -1 , molecular weight distribution M w / M n =2.5, polymer T m =131.2℃.

[0220] Example 17

[0221] In this embodiment, the main catalyst (complex Fe-4) and the co-catalyst (MMAO) jointly catalyze ethylene polymerization under high pressure:

[0222] The same as Example 14(g) except that the main catalyst is Fe-4. This catalytic combination shows no catalytic activity for ethylene polymerization.

[0223] Example 18

[0224] In this embodiment, the main catalyst (complex Fe-1) and the co-catalyst (MAO) jointly catalyze ethylene polymerization under high pressure:

[0225] (a) Under an ethylene atmosphere, 25 mL of a toluene solution of Fe-1 catalyst (1 μmol) was injected into a 250 mL stainless steel autoclave equipped with a mechanical stirrer. Then, 25 mL of toluene was added, followed by 1.7 mL of a toluene solution of cocatalyst MAO (1.46 mol / L). Further toluene was added until the total solvent volume reached 100 mL. At this point, the ratio of Al / Fe was 2500:1. Mechanical stirring was initiated and maintained at 400 rpm. When the polymerization temperature reached 40°C, ethylene was added to the reactor to initiate the polymerization reaction. The polymerization reaction was stirred at 40°C and maintained at an ethylene pressure of 10 atm for 30 min. The reaction solution was neutralized with ethanol solution acidified with 10% hydrochloric acid to obtain a polymer precipitate. The precipitate was washed several times with ethanol and dried under vacuum at 60°C to constant weight. The polymer was weighed to yield 2.1 g, with a polymerization activity of 4.2 × 10 6 g(PE)(mol Fe) -1 h -1 , the molecular weight of the obtained polymer M w =63.7 kg·mol -1 , molecular weight distribution M w / M n =10.7(M w is the weight average molecular weight of the polymer, M n is the number average molecular weight of the polymer, obtained by GPC test), polymer T m =131.3℃(T m is the melting temperature of the polymer, obtained by DSC testing).

[0226] (b) is basically the same as Example (a), except that the polymerization temperature is 50°C. Polymerization activity: 6.3×10 6 g(PE)(mol Fe) -1 h -1 , polymer molecular weight M w =98.4 kg·mol -1 , molecular weight distribution M w / M n =8.3, polymer T m =133.3℃.

[0227] (c) is basically the same as Example (a), except that the polymerization temperature is 60°C. Polymerization activity: 2.22×10 7 g(PE)(mol Fe) -1 h -1 , polymer molecular weight M w =150.9 kg·mol -1 , molecular weight distribution M w / M n =8.4, polymer T m =134.4℃.

[0228] (d) is basically the same as in Example (a), except that the polymerization temperature is 70°C. Polymerization activity: 2.02×10 7 g(PE)(mol Fe) -1 h -1 , polymer molecular weight M w =55.6 kg·mol -1 , molecular weight distribution M w / M n =4.3, polymer T m =132.7℃.

[0229] (e) Same as Example (a), except that the polymerization temperature was 80°C. Polymerization activity: 4.8×10 6 g(PE)(mol Fe) -1 h -1 , polymer molecular weight M w =37.0 kg·mol -1 , molecular weight distribution M w / M n =3.7, polymer T m =132.8℃.

[0230] (f) Same as Example (c), except that 1.5 mL of cocatalyst MAO (1.46 mol / L in toluene) was used to adjust the Al / Fe ratio to 2250:1. Polymerization activity: 1.8×10 6 g(PE)(mol Fe) -1 h -1 , polymer molecular weight M w =63.7 kg·mol -1 , molecular weight distribution M w / M n =4.2, polymer T m =132.9℃.

[0231] (g) Same as Example (c), except that 1.9 mL of cocatalyst MAO (1.46 mol / L in toluene) was used to adjust the Al / Fe ratio to 2750:1. Polymerization activity: 1.55 × 10 7 g(PE)(mol Fe) -1 h -1 , polymer molecular weight M w =71.9 kg·mol -1 , molecular weight distribution M w / M n =3.7, polymer T m =133.5℃.

[0232] (h) Same as Example (c), except that 2.1 mL of cocatalyst MAO (1.46 mol / L in toluene) was used to make the Al / Fe ratio 3000:1. Polymerization activity: 1.09×10 7 g(PE)(mol Fe) -1 h -1 , polymer molecular weight M w =60.4 kg·mol -1 , molecular weight distribution M w / M n =4.0, polymer T m =133.0℃.

[0233] Example 19

[0234] In this embodiment, the main catalyst (complex Fe-2) and the co-catalyst (MAO) jointly catalyze ethylene polymerization under high pressure:

[0235] Basically the same as Example 18(c), except that the main catalyst is Fe-2. Polymerization activity: 1.82×10 7 g(PE)(molFe) -1 h -1 , polymer molecular weight M w =55.2 kg·mol -1 , molecular weight distribution M w / M n =4.0, polymer T m =133.6℃.

[0236] Example 20

[0237] In this embodiment, the main catalyst (complex Fe-3) and the co-catalyst (MAO) jointly catalyze ethylene polymerization under high pressure:

[0238] Basically the same as Example 18(c), except that the main catalyst is Fe-3. Polymerization activity: 3.3×10 6 g(PE)(molFe) -1 h -1 , polymer molecular weight M w =127.6 kg·mol -1 , molecular weight distribution M w / M n =5.5, polymer T m =134.6℃.

[0239] Example 21

[0240] In this embodiment, the main catalyst (complex Fe-4) and the co-catalyst (MAO) jointly catalyze ethylene polymerization under high pressure:

[0241] Basically the same as Example 18(c), except that the main catalyst is Fe-4. Polymerization activity: 0.3×10 6 g(PE)(molFe) -1 h -1 , polymer molecular weight M w =93.6 kg·mol -1 , molecular weight distribution M w / M n =10.1, polymer T m =133.7℃.

[0242] Example 22

[0243] In this embodiment, the main catalyst (complex Co-3) and the co-catalyst (MMAO) jointly catalyze ethylene polymerization under high pressure:

[0244] (a) Under an ethylene atmosphere, 25 mL of a toluene solution of catalyst Co-3 (1 μmol) was injected into a 250 mL stainless steel autoclave equipped with a mechanical stirrer. Then, 25 mL of toluene was added, followed by 1.0 mL of a n-hexane solution of the cocatalyst MMAO (1.93 mol / L). Further toluene was added to bring the total solvent volume to 100 mL. At this point, the Al / Co ratio was 2000:1. Mechanical stirring was initiated and maintained at 400 rpm. When the polymerization temperature reached 40°C, ethylene was added to the reactor to initiate the polymerization reaction. The polymerization reaction was stirred at 40°C, maintaining an ethylene pressure of 10 atm, for 30 min. The reaction solution was neutralized with an ethanol solution acidified with 10% hydrochloric acid to obtain a polymer precipitate. The precipitate was washed several times with ethanol and dried under vacuum at 60°C to constant weight. The polymer was weighed to yield 1.6 g, with a polymerization activity of 3.2 × 10 6 g(PE)(mol Co) -1 h -1 , the molecular weight of the obtained polymer M w =42.3 kg·mol -1 , molecular weight distribution M w / M n =1.9(M w is the weight average molecular weight of the polymer, M n is the number average molecular weight of the polymer, obtained by GPC test), polymer T m =133.5℃(T m is the melting temperature of the polymer, obtained by DSC testing).

[0245] (b) is basically the same as Example (a), except that the polymerization temperature is 50°C. Polymerization activity: 3.7×10 6 g(PE)(mol Co) -1 h -1 , polymer molecular weight M w =31.7 kg·mol -1 , molecular weight distribution M w / M n =1.9, polymer T m =132.8℃.

[0246] (c) is basically the same as in Example (a), except that the polymerization temperature is 60°C. Polymerization activity: 5.0×10 6 g(PE)(mol Co) -1 h -1 , polymer molecular weight M w =26.3 kg·mol -1 , molecular weight distribution M w / M n =1.7, polymer T m =133.2℃.

[0247] (d) is basically the same as Example (a), except that the polymerization temperature is 70°C. Polymerization activity: 3.3×10 6 g(PE)(mol Co) -1 h -1 , polymer molecular weight M w =18.0 kg·mol -1 , molecular weight distribution M w / M n =1.6, polymer T m =132.0℃.

[0248] (e) is basically the same as in Example (a), except that the polymerization temperature is 80°C. Polymerization activity: 1.7×10 6 g(PE)(mol Co) -1 h -1 , polymer molecular weight M w =19.0 kg·mol -1 , molecular weight distribution M w / M n =1.7, polymer T m =131.7℃.

[0249] (f) Same as Example (c), except that 0.9 mL of cocatalyst MMAO (1.93 mol / L in n-hexane) was used to adjust the Al / Co ratio to 1750:1. Polymerization activity: 3.4 × 10 6g(PE)(mol Co) -1 h -1 , polymer molecular weight M w =26.1 kg·mol -1 , molecular weight distribution M w / M n =2.1, polymer T m =131.9℃.

[0250] (g) Same as Example (c), except that 1.2 mL of cocatalyst MMAO (1.93 mol / L in n-hexane) was used to adjust the Al / Co ratio to 2250:1. Polymerization activity: 5.4 × 10 6 g(PE)(mol Co) -1 h -1 , polymer molecular weight M w =22.8 kg·mol -1 , molecular weight distribution M w / M n =1.8, polymer T m =131.5℃.

[0251] (h) Same as Example (c), except that 1.3 mL of MMAO (1.93 mol / L in n-hexane) was used to make the Al / Co ratio 2500:1. Polymerization activity: 3.5×10 6 g(PE)(mol Co) -1 h -1 , polymer molecular weight M w =26.5kg·mol -1 , molecular weight distribution M w / M n =1.7, polymer T m =132.7℃.

[0252] (i) Same as Example (c), except that 1.4 mL of cocatalyst MMAO (1.93 mol / L in n-hexane) was used to adjust the Al / Co ratio to 2750:1. Polymerization activity: 2.6 × 10 6 g(PE)(mol Co) -1 h -1 , polymer molecular weight M w =26.2 kg·mol -1 , molecular weight distribution M w / M n =1.8, polymer T m =133.4℃.

[0253] Example 23

[0254] In this embodiment, the main catalyst (complex Co-1) and the co-catalyst (MMAO) jointly catalyze ethylene polymerization under high pressure:

[0255] Basically the same as Example 22(g), except that the main catalyst is Co-1. Polymerization activity: 5.6×10 6 g(PE)(molCo) -1 h -1 , polymer molecular weight M w =28.1 kg·mol -1 , molecular weight distribution M w / M n =1.7, polymer T m =130.0℃.

[0256] Example 24

[0257] In this embodiment, the main catalyst (complex Co-2) and the co-catalyst (MMAO) jointly catalyze ethylene polymerization under high pressure:

[0258] Basically the same as Example 22(g), except that the main catalyst is Co-2. Polymerization activity: 3.1×10 6 g(PE)(molCo) -1 h -1 , polymer molecular weight M w =33.6 kg·mol -1 , molecular weight distribution M w / M n =1.7, polymer T m =131.9℃.

[0259] Example 25

[0260] In this embodiment, the main catalyst (complex Co-4) and the co-catalyst (MMAO) jointly catalyze ethylene polymerization under high pressure:

[0261] Basically the same as Example 22(g), except that the main catalyst is Co-4. Polymerization activity: 0.2×10 6 g(PE)(molCo) -1 h -1 , polymer molecular weight M w =22.6 kg·mol -1 , molecular weight distribution M w / M n =10.6, polymer T m =128.5℃.

[0262] Example 26

[0263] In this embodiment, the main catalyst (complex Co-3) and the co-catalyst (MAO) jointly catalyze ethylene polymerization under high pressure:

[0264] (a) Under an ethylene atmosphere, 25 mL of a toluene solution of catalyst Co-3 (1 μmol) was injected into a 250 mL stainless steel autoclave equipped with a mechanical stirrer. Then, 25 mL of toluene was added, followed by 1.4 mL of a toluene solution of cocatalyst MAO (1.46 mol / L). Further toluene was added until the total solvent volume reached 100 mL. At this point, the Al / Co ratio was 2000:1. Mechanical stirring was initiated and maintained at 400 rpm. When the polymerization temperature reached 40°C, ethylene was added to the autoclave to initiate the polymerization reaction. The polymerization reaction was stirred at 40°C and maintained at an ethylene pressure of 10 atm for 30 min. The reaction solution was neutralized with ethanol solution acidified with 10% hydrochloric acid to obtain a polymer precipitate. The precipitate was washed several times with ethanol and dried under vacuum at 60°C to constant weight. The polymer was weighed to yield 1.4 g, with a polymerization activity of 2.8 × 10 6 g(PE)(mol Co) -1 h -1 , the molecular weight of the obtained polymer M w =56.1 kg·mol -1 , molecular weight distribution M w / M n =1.8(M w is the weight average molecular weight of the polymer, M n is the number average molecular weight of the polymer, obtained by GPC test), polymer T m =136.4℃(T m is the melting temperature of the polymer, obtained by DSC testing).

[0265] (b) is basically the same as Example (a), except that the polymerization temperature is 50°C. Polymerization activity: 3.2×10 6 g(PE)(mol Co) -1 h -1 , polymer molecular weight M w =41.5 kg·mol -1 , molecular weight distribution M w / M n =1.9, polymer T m =133.3℃.

[0266] (c) is basically the same as in Example (a), except that the polymerization temperature is 60°C. Polymerization activity: 7.1×10 6 g(PE)(mol Co) -1 h -1 , polymer molecular weight M w =34.3 kg·mol -1, molecular weight distribution M w / M n =1.9, polymer T m =132.4℃.

[0267] (d) is basically the same as in Example (a), except that the polymerization temperature is 70°C. Polymerization activity: 3.6×10 6 g(PE)(mol Co) -1 h -1 , polymer molecular weight M w =33.0 kg·mol -1 , molecular weight distribution M w / M n =1.8, polymer T m =133.8℃.

[0268] (e) is basically the same as in Example (a), except that the polymerization temperature is 80°C. Polymerization activity: 2.8×10 6 g(PE)(mol Co) -1 h -1 , polymer molecular weight M w =21.7 kg·mol -1 , molecular weight distribution M w / M n =1.8, polymer T m =133.2℃.

[0269] (f) Same as Example (c), except that 1.5 mL of cocatalyst MAO (1.46 mol / L in toluene) was used to adjust the Al / Co ratio to 2250:1. Polymerization activity: 7.2 × 10 6 g(PE)(mol Co) -1 h -1 , polymer molecular weight M w =34.4 kg·mol -1 , molecular weight distribution M w / M n =1.7, polymer T m =133.2℃.

[0270] (g) Same as Example (c), except that 1.7 mL of cocatalyst MAO (1.46 mol / L in toluene) was used to make the Al / Co ratio 2500:1. Polymerization activity: 8.4×10 6 g(PE)(mol Co) -1 h -1 , polymer molecular weight M w =35.1 kg·mol -1 , molecular weight distribution M w / Mn =1.8, polymer T m =132.4℃.

[0271] Take 10 mg of the obtained polymer and dissolve it in 3 ml of deuterated 1,1,2,2-tetrachloroethane. Test the polymer at 100 °C. 1 H data, such as Figure 3 As shown, the signal is accumulated 64 times.

[0272] Take 60 mg of the obtained polymer and dissolve it in 3 ml of deuterated 1,1,2,2-tetrachloroethane. Test the polymer at 100 °C. 13 C data, such as Figure 3 The signal is accumulated 3000 times.

[0273] (h) Same as Example (c), except that 1.9 mL of cocatalyst MAO (1.46 mol / L in toluene) was used to adjust the Al / Co ratio to 2750:1. Polymerization activity: 6.8 × 10 6 g(PE)(mol Co) -1 h -1 , polymer molecular weight M w =34.7 kg·mol -1 , molecular weight distribution M w / M n =1.9, polymer T m =132.6℃.

[0274] (i) Same as Example (c), except that 2.1 mL of cocatalyst MAO (1.46 mol / L in toluene) was used to make the Al / Co ratio 3000:1. Polymerization activity: 5.5×10 6 g(PE)(mol Co) -1 h -1 , polymer molecular weight M w =35.4 kg·mol -1 , molecular weight distribution M w / M n =1.7, polymer T m =132.5℃.

[0275] Example 27

[0276] In this embodiment, the main catalyst (complex Co-1) and the co-catalyst (MAO) jointly catalyze the polymerization of ethylene under high pressure:

[0277] Basically the same as Example 26(g), except that the main catalyst is Co-1. Polymerization activity: 1.03×10 7 g(PE)(molCo) -1h -1 , polymer molecular weight M w =24.8 kg·mol -1 , molecular weight distribution M w / M n =2.2, polymer T m =131.3℃.

[0278] Example 28

[0279] In this embodiment, the main catalyst (complex Co-2) and the co-catalyst (MAO) jointly catalyze ethylene polymerization under high pressure:

[0280] Basically the same as Example 26(g), except that the main catalyst is Co-2. Polymerization activity: 8.6×10 6 g(PE)(molCo) -1 h -1 , polymer molecular weight M w =36.0 kg·mol -1 , molecular weight distribution M w / M n =1.8, polymer T m =132.6℃.

[0281] Example 29

[0282] In this embodiment, the main catalyst (complex Co-4) and the co-catalyst (MAO) jointly catalyze ethylene polymerization under high pressure:

[0283] Basically the same as Example 26(g), except that the main catalyst is Co-4. Polymerization activity: 0.3×10 6 g(PE)(molCo) -1 h -1 , polymer molecular weight M w =22.0 kg·mol -1 , molecular weight distribution M w / M n =12.1, polymer T m =127.9℃.

[0284] The above description is merely a preferred embodiment of the present invention and does not constitute any form of limitation to the present invention. Although the present invention has been disclosed as above in terms of a preferred embodiment, it is not intended to limit the present invention. Any technician familiar with this patent can make slight changes or modifications to equivalent embodiments using the above technical content without departing from the scope of the technical solution of the present invention. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the solution of the present invention.

Claims

1. A late transition metal complex characterized by: Having the structure shown in formula (I): Wherein, M is iron or cobalt; Each X is the same or different and is independently selected from F, Cl, Br, I; Each R 1 The same or different, each independently selected from H or C 1-6 alkyl; Each R 3 are all diphenylmethyl; R 4 is selected from cyclopentyl, cyclohexyl, cyclooctyl or cyclododecyl; Each R 2 、R 5 、R 6 Both are H.

2. A late transition metal complex according to claim 1, characterized in that Each R 1 are all methyl; each R 3 are all diphenylmethyl; R 4 is selected from cyclopentyl, cyclohexyl, cyclooctyl or cyclododecyl; each R 2 、R 5 、R 6 Both are H.

3. The late transition metal complex according to claim 1, characterized in that Each R 1 are all methyl; each R 3 are all diphenylmethyl; R 4 is selected from cyclopentyl, cyclohexyl or cyclooctyl; each R 2 、R 5 、R 6 Both are H.

4. A ligand compound, characterized in that Having a structure as shown in formula (II); Wherein, R in the formula (II) 1 、R 2 、R 3 、R 4 、R 5 、R 6 R in the formula (I) according to claim 1 1 、R 2 、R 3 、R 4 、R 5 、R 6 same.

5. A method for preparing a late transition metal complex according to claim 1, characterized in that: The late transition metal complex is prepared by complexing the ligand compound of formula (II) described in claim 4 with compound MX2; Wherein, M and X in the compound MX2 are the same as M and X in the formula (I).

6. The method for preparing a late transition metal complex according to claim 5, wherein The compound MX2 is selected from at least one of an iron- or cobalt-containing halide, a hydrate or a solvate of an iron- or cobalt-containing halide.

7. The method for preparing a late transition metal complex according to claim 5, wherein The compound MX2 is selected from at least one of FeCl2, FeCl2·4H2O, CoCl2 or CoCl2·6H2O.

8. The method for preparing a late transition metal complex according to claim 5, wherein The preparation method of the late transition metal complex includes step S1: the ligand compound of formula (II) and the compound MX2 are mixed in an organic solvent A at a molar ratio of (1 to 1.5):1, and a complexation reaction is carried out at 10 to 35°C for 8 to 16 hours to obtain the late transition metal complex.

9. The method for preparing a late transition metal complex according to claim 8, wherein The complexation reaction is carried out under anaerobic conditions; the complexation reaction time is 11 to 13 hours; the molar ratio of the ligand compound of formula (II) to the compound MX2 is (1 to 1.3):1; the organic solvent A is selected from at least one of an alcohol solvent and a halogenated alkane solvent.

10. The method for preparing a late transition metal complex according to claim 8, wherein The complexation reaction is carried out under an inert gas.

11. The method for preparing a late transition metal complex according to claim 10, wherein: The complexation reaction is carried out under nitrogen conditions.

12. The method for preparing a late transition metal complex according to claim 8, wherein The molar ratio of the ligand compound of formula (II) to the compound MX2 is 1.1:1; the organic solvent A is selected from at least one of anhydrous ethanol and dichloromethane.

13. The method for preparing a late transition metal complex according to any one of claims 8 to 12, characterized in that: The method for preparing the late transition metal complex further comprises: purifying the late transition metal complex prepared in step S1, wherein the purification process comprises the following steps: Step S2-1: extracting the solvent from the late transition metal complex prepared in step S1, and then dissolving it in an organic solvent B for precipitation to obtain a precipitation system; Step S2-2: performing solid-liquid separation on the precipitation system obtained in step S2-1, washing the solid phase with an organic solvent B and drying the solid phase to obtain a purified late transition metal complex.

14. The method for preparing a late transition metal complex according to claim 13, wherein: In step S2-1, a vacuum pump is used to extract the solvent in the late transition metal complex; the organic solvent B in step S2-1 and step S2-2 is an anhydrous organic solvent, and the anhydrous organic solvent is at least one of anhydrous ether and anhydrous n-hexane.

15. A method for preparing the ligand compound according to claim 4, characterized in that: The ligand compound of formula (II) is prepared by condensing the ligand compound of formula (III) with an aniline compound of formula (IV-1); R in the formula (III) 1 、R 2 、R 6 R in the formula (II) according to claim 4 1 、R 2 、R 6 same; Wherein, R in the formula (IV-1) 3 、R 4 、R 5 and R in the formula (II) 3 、R 4 、R 5 same.

16. The method for preparing the ligand compound according to claim 15, characterized in that: The preparation method of the ligand compound of formula (II) comprises the following steps: Step S1: The ligand compound of formula (III) and the aniline compound of formula (IV-1) are mixed in an organic solvent C at a molar ratio of (1-2):1, and reacted for 6-12 hours under heating reflux and catalysis of organic acid a to obtain the ligand compound of formula (II).

17. The method for preparing the ligand compound according to claim 16, characterized in that: The molar ratio of the ligand compound of formula (III) to the aniline compound of formula (IV-1) is 1.5:1; and the condensation reaction time is 8 to 10 hours.

18. The method for preparing the ligand compound according to claim 17, characterized in that: The organic acid a is selected from at least one of formic acid, acetic acid and p-toluenesulfonic acid.

19. The method for preparing the ligand compound according to claim 18, characterized in that: The organic acid a is selected from p-toluenesulfonic acid.

20. The method for preparing the ligand compound according to claim 16, wherein: The organic solvent C is an aromatic hydrocarbon solvent.

21. The method for preparing the ligand compound according to claim 20, characterized in that: The organic solvent C is toluene.

22. The method for preparing the ligand compound according to any one of claims 16 to 21, characterized in that: The method for preparing the ligand compound of formula (II) further comprises: purifying the ligand compound of formula (II) prepared in step S1, wherein the purification process comprises the following steps: Step S2-1: dissolving the ligand compound of formula (II) prepared in step S1 in dichloromethane to obtain a solution; Step S2-2: using basic alumina for support, performing column chromatography on a silica basic alumina column, eluting the solution obtained in step S2-1 with a mixed solvent of petroleum ether and ethyl acetate as an eluent, and detecting the eluted fraction by thin layer chromatography; Step S2-3: The solvent is removed again to obtain a purified ligand compound of formula (II).

23. A use of the ligand compound according to claim 4, characterized in that: The invention also comprises the use of the ligand compound of formula (II) in preparing the late transition metal complex.

24. Use of the late transition metal complex according to claim 1 in catalyzing olefin polymerization.

25. The use according to claim 24, characterized in that Application in catalytic ethylene polymerization.

26. A catalyst composition, characterized in that include: A main catalyst and a co-catalyst, wherein the main catalyst is the late transition metal complex according to claim 1, and the co-catalyst is selected from at least one of aluminoxane, alkylaluminum and alkylaluminum chloride.

27. The catalyst composition according to claim 26, characterized in that The molar ratio of the metal Al in the co-catalyst to the central metal M in the late transition metal complex is (500-4000):

1.

28. The catalyst composition according to claim 27, characterized in that The molar ratio is (1000-3500):

1.

29. The catalyst composition according to claim 27, characterized in that The molar ratio is selected from any one of 1000:1, 1500:1, 1750:1, 2000:1, 2250:1, 2500:1, 2750:1, and 3250:

1.

30. The catalyst composition according to claim 26, characterized in that The aluminoxane is selected from at least one of methylaluminoxane and triisobutylaluminum-modified methylaluminoxane; the alkylaluminum is selected from at least one of diethylaluminum and dimethylaluminum; and the alkylaluminum chloride is selected from at least one of diethylaluminum chloride and dimethylaluminum chloride.

31. The catalyst composition according to claim 30, characterized in that When the co-catalyst is methylaluminoxane, the molar ratio of the metal Al in the methylaluminoxane to the central metal M in the late transition metal complex is (2000-3000):

1.

32. The catalyst composition according to claim 31, characterized in that The molar ratio is 2500:

1.

33. The catalyst composition according to claim 30, characterized in that When the co-catalyst is triisobutylaluminum-modified methylaluminoxane, the molar ratio of the metal Al in the triisobutylaluminum-modified methylaluminoxane to the central metal M in the late transition metal complex is (1750-2750):

1.

34. The catalyst composition according to claim 33, characterized in that The molar ratio is 2250:

1.

35. The catalyst composition according to claim 30, characterized in that The alkyl group in the alkylaluminum and alkylaluminum chloride is selected from alkyl groups having 1 to 3 carbon atoms.

36. A method for preparing an olefin polymer, characterized in that: include: Under the action of the catalyst composition according to claim 26, olefins are catalyzed to undergo polymerization reaction to obtain the olefin polymer.

37. The method for preparing an olefin polymer according to claim 36, wherein: The polymerization reaction temperature is 30-100°C.

38. The method for preparing an olefin polymer according to claim 37, wherein: The polymerization reaction temperature is 40-90°C.

39. The method for preparing an olefin polymer according to claim 37, wherein: The polymerization reaction temperature is 40°C, 50°C, 60°C, 70°C, 80°C or 90°C.

40. The method for preparing an olefin polymer according to claim 36, wherein: The reaction time of the polymerization reaction is 5 to 60 minutes.

41. The method for preparing an olefin polymer according to claim 40, wherein: The reaction time of the polymerization reaction is 20 to 40 minutes.

42. The method for preparing an olefin polymer according to claim 40, wherein: The reaction time of the polymerization reaction is 30 min.

43. The method for preparing an olefin polymer according to claim 36, wherein: The polymerization reaction pressure is 0.5 to 10 atm.

44. The method for preparing an olefin polymer according to claim 43, wherein The polymerization reaction pressure was 10 atm.

45. The method for preparing an olefin polymer according to claim 36, wherein: The polymerization reaction is carried out under an ethylene atmosphere, and the catalyst composition is dissolved in an organic solvent E; the organic solvent E is selected from at least one of toluene, o-xylene, dichloromethane, ethanol, tetrahydrofuran, hexane or cyclohexane.

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