Cobalt complex, preparation method thereof, catalyst and application

Abstract

The invention provides a cobalt complex, a preparation method thereof, a catalyst and application, the complex has a structure as shown in formula (1), in the formula (1), R1, R2, R3, R4 and R5 are respectively and independently selected from H, C1-6 alkyl substituted or unsubstituted by Ra, C1-6 alkoxy substituted or unsubstituted by Ra, C6-20 aryl substituted or unsubstituted by Ra, and C6-20 heteroatom aryl substituted or unsubstituted by Ra, and R1, R2, R3, R4 and R5 are respectively and independently selected from H, C1-6 alkyl substituted or unsubstituted by Ra, C6-20 alkoxy substituted or unsubstituted by Ra, C6-20 heteroatom aryl substituted or unsubstituted by Ra, C6-20 heteroatom aryl substituted or unsubstituted by Ra, and C6-20 heteroatom aryl substituted or unsubstituted by Ra. The complex provided by the invention has higher activity, can control the microstructure of a polymer during olefin polymerization, and obtains a high-linearity polyethylene product with good heat resistance, a double bond at the end group and a weight-average molecular weight of 10-30 kg.mol <-1 >.

Description

Technical Field

[0001] This invention belongs to the field of polyolefin catalyst technology, specifically relating to a cobalt complex, its preparation method, catalyst, and application. Background Technology

[0002] Polyolefins are widely used in many fields such as military, agriculture, industry, medical, and healthcare due to their excellent mechanical and thermodynamic properties, ease of processing and crystallization, and non-toxicity and safety. Furthermore, through copolymerization and modification, the relevant properties of polyolefin materials can be improved, such as impact resistance, heat resistance, thermal conductivity, heat-sealing temperature, transparency, and shielding properties, resulting in high-performance polyolefin materials. Polyethylene is the most produced polyolefin material, and its properties are mainly determined by its microstructure. The key to controlling the polymer microstructure is the selection of catalysts, including the type of central metal, the valence state of the active material, and the steric hindrance and electronic effects of the ligands. In addition, the properties of the polymerization products are also highly dependent on the polymerization method and reaction conditions. Based on different production processes, the polymerization products can be mainly classified into various topologies such as highly linear crystalline, linear semi-crystalline, moderately branched, and highly branched amorphous polyethylene; in addition, there are other polymerization products with unique properties.

[0003] Generally, α-olefins refer to olefins terminated by unsaturated double bonds. This type of material is easily further functionalized. Therefore, these materials are widely used as chemical intermediates, building blocks, and starting materials, and the development prospects of the corresponding chemicals are broad. As comonomers, α-olefins continue to see development in applications such as detergents, plasticizers, lubricants, and additives. Depending on the carbon number, α-olefins have different application ranges.

[0004] Linear, low molecular weight polyethylene has excellent mechanical properties, wear and heat resistance, good lubricity, dispersibility and flowability, and good compatibility with other polyolefin resins. It can be used as a processing aid for pipes, films, cables and other plastics and rubbers.

[0005] Therefore, it is possible to design and synthesize materials with high linearity, good heat resistance, and a weight-average molecular weight of 10-30 kg·mol⁻¹. -1 Catalysts for polyethylene products are currently the core focus of research, aiming to meet the growing societal demand for high-end polyethylene products. Summary of the Invention

[0006] This invention provides a cobalt complex to address the difficulty in synthesizing high-linearity, heat-resistant compounds with a weight-average molecular weight of 10-30 kg·mol⁻¹ in existing technologies. -1 Polyethylene products between.

[0007] This invention provides a method for preparing cobalt complexes, which has the advantages of mild reaction conditions, short cycle and simple operation.

[0008] This invention provides a catalyst comprising the above-described complex and the complex prepared by the above-described preparation method, which can be used in ethylene polymerization to produce polyethylene products with high linearity and low molecular weight, and has excellent controllability over the structure of polyethylene products.

[0009] The present invention also provides the application of the above-mentioned complex and the complex prepared by the above preparation method as a catalyst in the catalytic polymerization of olefins.

[0010] In a first aspect, the present invention provides a cobalt complex having the structure shown in formula (1):

[0011]

[0012] Each X is independently selected from at least one of F, Cl, Br, and I;

[0013] R 1 R 2 R 3 R 4 R 5 Each is independently selected from H and R. a C with or without substitution 1-6 Alkyl, R a C with or without substitution 1-6 Alkyl groups, by R a C with or without substitution 6-20 Aryl, R a C with or without substitution 6-20 heteroatomic aryl;

[0014] Each R a Each is independently selected from F, Cl, Br, I, and C. 1-6 Alkyl, C 1-6 Alkoxy, C 3-10 Heterocyclic group, C 6-20 Aryl or C 6-20 Heteroatomic aryl group.

[0015] Furthermore, R 1 Selected from C 1-3 alkyl.

[0016] Furthermore, R 2 Selected from C 1-3 alkyl.

[0017] Furthermore, R 3 R 4 Each is independently selected from H or C1-6 alkyl.

[0018] Furthermore, R 1 and R 2 All are methyl groups, X is Cl, R 3 R 4 R 5 All are H; or,

[0019] R 1 and R 2 All are ethyl groups, X is Cl, and R is... 3 R 4 R 5 All are H; or,

[0020] R 1 and R 2 All are isopropyl, X is Cl, R 3 R 4 R 5 All are H; or,

[0021] R 1 For methyl, R 2 For ethyl, X is Cl, R 3 R 4 R 5 All are H.

[0022] In a second aspect, the present invention provides a method for preparing the complex described in the first aspect, comprising the following steps:

[0023] 2,6-Diacetylpyridine was condensed with an aniline compound as shown in formula (2) and compound CoX2 to obtain the complex shown in formula (1);

[0024]

[0025] Each X is independently selected from at least one of F, Cl, Br, and I;

[0026] R 1 R 2 R 3 R 4 R 5 Each is independently selected from H and R. a C with or without substitution 1-6 Alkyl, R a C with or without substitution 1-6 Alkyl groups, by R a C with or without substitution 6-20 Aryl, R a C with or without substitution 6-20 heteroatomic aryl;

[0027] Each R a Each is independently selected from F, Cl, Br, I, and C. 1-6 Alkyl, C 1-6 Alkoxy, C 3-10 Heterocyclic group, C 6-20 Aryl or C 6-20 Heteroatomic aryl group.

[0028] Furthermore, the molar ratio of the compound CoX2 to the aniline compound is 1:(2-3).

[0029] Thirdly, the present invention provides a catalyst comprising the complex described in the first aspect or the complex prepared by the preparation method described in the second aspect.

[0030] Furthermore, it also includes co-catalysts;

[0031] The co-catalyst comprises methylaluminoxane, wherein the molar ratio of Al in the methylaluminoxane to Co in the complex is (1000-3000):1; and / or,

[0032] The cocatalyst comprises triisobutylaluminum-modified methylaluminoxane, wherein the molar ratio of Al in the triisobutylaluminum-modified methylaluminoxane to Co in the complex is (1000-2500):1; and / or,

[0033] The co-catalyst comprises alkylaluminum, wherein the molar ratio of Al to Co in the complex is (200-2000):1; and / or,

[0034] The co-catalyst includes alkyl aluminum chloride, wherein the molar ratio of Al to Co in the complex is (200-2000):1.

[0035] Fourthly, the present invention relates to the application of the complex described in the first aspect, the complex prepared by the method described in the second aspect, and the catalyst described in the third aspect in the catalytic polymerization of olefins.

[0036] This invention provides a cobalt complex comprising an arylthionyl group with an introduced N-aryl group. The arylthionyl group can coordinate with the central cobalt metal to form unique steric hindrance and electronic effects, giving the complex higher activity. This allows for control of the polymer's microstructure during olefin polymerization, resulting in a complex with good heat resistance, double bonds at the end groups, and a weight-average molecular weight of 10-30 kg·mol⁻¹. -1 High linear polyethylene products have excellent lubricity, dispersibility and flowability, and good compatibility with other polyolefin resins. They can be used as processing aids for pipes, films, cables and other plastics and rubbers. Attached Figure Description

[0037] Figure 1 This is a schematic diagram of the crystal structure of the complex Co-4 obtained in Example 4;

[0038] Figure 2 The above is the heated 1H NMR and 1C NMR spectrum of the polymer obtained in experimental group 21 of Experimental Example 1. Detailed Implementation

[0039] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions in the embodiments of this invention will be clearly and completely described below in conjunction with the embodiments of this invention. Obviously, the described embodiments are only some embodiments of this invention, not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0040] In a first aspect, the present invention provides a cobalt complex having the structure shown in formula (1):

[0041]

[0042] Each X is independently selected from at least one of F, Cl, Br, and I;

[0043] R 1 R 2 R 3 R 4 R 5 Each is independently selected from H and R. a C with or without substitution 1-6 Alkyl, R a C with or without substitution 1-6 Alkyl groups, by R a C with or without substitution 6-20 Aryl, R a C with or without substitution 6-20 heteroatomic aryl;

[0044] Each R a Each is independently selected from F, Cl, Br, I, and C. 1-6 Alkyl, C 1-6 Alkoxy, C 3-10 Heterocyclic group, C 6-20 Aryl or C 6-20 Heteroatomic aryl group.

[0045] Among them, “C” 1-6 "Alkyl" includes straight-chain or branched alkyl groups having 1 to 6 carbon atoms. For example, alkyl groups can be methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, sec-butyl, pentyl, neopentyl, etc.

[0046] Optionally, "C" 1-6 "Alkoxy" includes straight-chain or branched saturated monovalent hydrocarbon groups with the formula "-O-alkyl" having 1 to 6 carbon atoms, such as methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, sec-butoxy, tert-butoxy, pentoxy, isopentoxy, hexoxy or their isomers.

[0047] Optionally, "C" 3-10 Heterocyclic groups include groups with the formula "-N / O / S-cycloalkyl" having 3-10 carbon atoms. The heterocyclic group can be attached to the rest of the molecule via any one of the carbon atoms or a nitrogen atom (if present). Specifically, heterocyclic groups can include, but are not limited to: 4-membered rings, such as azirrobutyl or oxobutyl; 5-membered rings, such as tetrahydrofuranyl, dioxacyclopentenyl, pyrrolyl, imidazoalkyl, pyrazolyl, or pyrrololinyl; or 6-membered rings, such as tetrahydropyranyl, piperidinyl, morpholinyl, dithiaalkyl, thiomorpholinyl, piperazineyl, or trithiaalkyl; or 7-membered rings, such as diazacycloheptyl. Optionally, the heterocyclic group can be... Benzofused. The heterocyclic group can be bicyclic, such as, but not limited to, a 5,5-membered ring, like a hexahydrocyclopentano[c]pyrrole-2(1H)-yl ring, or a 5,6-membered bicyclic ring, like a hexahydropyrrolo[1,2-a]pyrazin-2(1H)-yl ring. The nitrogen-containing ring can be partially unsaturated, i.e., it can contain one or more double bonds, such as, but not limited to, 2,5-dihydro-1H-pyrrole, 4H-[1,3,4]thiadiazinyl, 4,5-dihydrooxazolyl, or 4H-[1,4]thiazinyl, or it can be benzofused, such as, but not limited to, dihydroisoquinolinyl. According to the invention, the heterocyclic group is non-aromatic;

[0048] Optionally, "C" 6-20 "Aryl" includes monocyclic, bicyclic, or tricyclic hydrocarbon rings with monovalent aromatic or partially aromatic properties having 6 to 20 carbon atoms, and can further be "C 6-14 "Aryl"; among which, "C" 6-14 "Aryl" includes monovalent aromatic or partially aromatic monocyclic, bicyclic, or tricyclic hydrocarbon rings ("C") having 6, 7, 8, 9, 10, 11, 12, 13, or 14 carbon atoms. 6-14 Aryl), particularly a ring with 6 carbon atoms (“C6 aryl”), such as phenyl; or biphenyl, or a ring with 9 carbon atoms (“C9 aryl”), such as indenyl or indenyl, or a ring with 10 carbon atoms (“C9 aryl”). 10 Aryl groups, such as tetrahydronaphthyl, dihydronaphthyl, or naphthyl, or rings with 13 carbon atoms (“C”). 13 Aryl groups, such as fluorene groups, or rings with 14 carbon atoms (“C”). 14Aryl), for example, anthracene;

[0049] Optionally, "C" 6-20 "Heteroatom aryl" includes groups of the formula -N-aryl or -N-heteroaryl having 6 to 20 carbon atoms. Monocyclic examples of heteroaryl groups include, but are not limited to, thiophene, furanyl, pyrrole, oxazolyl, thiazolyl, imidazolyl, pyrazolyl, isoxazolyl, isothiazolyl, oxadiazolyl, triazolyl, thiadiazolyl, thia-4H-pyrazolyl, and their benzo[a] derivatives, such as benzofuranyl, benzothiophene, benzooxazolyl, benzoisooxazolyl, etc. Benzimidazolyl, benzotriazolyl, indazole, indolyl, isoindolyl, etc.; or pyridyl, pyridazinyl, pyrimidinyl, pyrazinyl, triazinyl, etc., and their benzo derivatives, such as quinolinyl, quinazolinyl, isoquinolinyl, etc.; or acrylinyl, inazinyl, purinyl, etc., and their benzo derivatives; or cinolinyl, phthalazinyl, quinazolinyl, quinoxalinyl, naphthidyl, pteridinyl, carbazoyl, acrylinyl, phenazinyl, phenothiazinyl, phenotoxazinyl, etc.

[0050] The present invention provides a cobalt complex having the structure shown in formula (1), comprising an arylthionyl group with an introduced N-aryl group. The arylthionyl group can coordinate with the central metallic cobalt to form unique steric hindrance and electronic effects, making the complex more active. It can control the microstructure of the polymer during olefin polymerization, resulting in a product with good heat resistance, double bonds at the end groups, and a weight-average molecular weight of 10-30 kg·mol⁻¹. -1 High linear polyethylene products have excellent lubricity, dispersibility and flowability, and good compatibility with other polyolefin resins. They can be used as processing aids for pipes, films, cables and other plastics and rubbers.

[0051] Furthermore, R 1 Selected from C 1-3 Alkyl groups; in this case, the cobalt complex provided by the present invention enables the synthesized polyethylene product to have higher linearity, heat resistance and a more suitable weight-average molecular weight.

[0052] Furthermore, R 2 Selected from C 1-3 Alkyl groups; similarly, the complexes at this point can enable the synthesized polyethylene products to have higher linearity, heat resistance, and a more suitable weight-average molecular weight.

[0053] Optionally, R 3 R 4 Each is independently selected from H or C 1-6 alkyl.

[0054] When R 3 R 4 Each is independently selected from H or C 1-6When alkyl groups are used to catalyze ethylene polymerization, they can further enhance polymerization activity, resulting in polymers with higher linearity and ideal weight-average molecular weight.

[0055] In one specific implementation, R 1 and R 2 All are methyl groups, X is Cl, R 3 R 4 R 5 All are H;

[0056] In one specific implementation, R 1 and R 2 All are ethyl groups, X is Cl, and R is... 3 R 4 R 5 All are H;

[0057] In one specific implementation, R 1 and R 2 All are isopropyl, X is Cl, R 3 R 4 R 5 All are H;

[0058] In one specific implementation, R 1 For methyl, R 2 For ethyl, X is Cl, R 3 R 4 R 5 All are H.

[0059] Through long-term research on olefin polymerization catalysts, the inventors discovered that the substituent selection method in the specific embodiments given above can further enhance the polymerization activity of the cobalt complex provided by this invention during ethylene polymerization, resulting in the synthesis of a highly linear, heat-resistant complex with a weight-average molecular weight of 10-30 kg·mol⁻¹. -1 Polyethylene products between.

[0060] Secondly, a method for preparing a cobalt complex provided in the first aspect includes the following steps:

[0061] 2,6-Diacetylpyridine was condensed with an aniline compound as shown in formula (2) and compound CoX2 to obtain the complex shown in formula (1);

[0062]

[0063] Each X is independently selected from at least one of F, Cl, Br, and I;

[0064] R 1 R 2 R 3 R4 R 5 Each is independently selected from H, F, Cl, Br, I, and R. a C with or without substitution 1-6 Alkyl, R a C with or without substitution 1-6 Alkyl groups, by R a C with or without substitution 6-20 Aryl, R a C with or without substitution 6-20 heteroatomic aryl;

[0065] Each R a Each is independently selected from F, Cl, Br, I, and C. 1-6 Alkyl, C 1-6 Alkoxy, C 3-10 Heterocyclic group, C 6-20 Aryl or C 6-20 Heteroatomic aryl group.

[0066] Among them, “C” 1-6 Alkyl", C 1-6 Alkoxy, C 3-10 Heterocyclic group, C 6-20 Aryl", "C" 6-20 The meanings of "heteroatomic aryl" are the same as in the first aspect, and will not be repeated here.

[0067] This invention does not limit the source of raw materials and reagents; they can be commercially available products or prepared by known methods.

[0068] The present invention does not limit the form of the compound CoX2, which can be a cobalt halide, or a hydrate or solvate of a halide, such as CoCl2 or CoCl2·6H2O.

[0069] The present invention provides a method for preparing cobalt complexes, which has the advantages of mild reaction conditions, short cycle and simple operation.

[0070] Furthermore, the molar ratio of compound CoX2 to aniline compound is 1:(2-3).

[0071] When the molar ratio of compound CoX2 to the aniline compound shown in formula (2) is 1:(2-3), the resulting complex can have higher activity, and the synthesized complex has high linearity, good heat resistance, and a weight-average molecular weight of 10-30 kg·mol⁻¹. -1 The above-mentioned polyethylene products are in the range of 1:(2-2.5), and in the specific embodiment, it is 1:2.5.

[0072] Furthermore, the condensation reaction is carried out under anaerobic conditions, such as under a protective atmosphere of an inert gas; optionally, the inert gas is nitrogen.

[0073] In one specific embodiment, the condensation reaction is carried out under the catalysis of an organic acid; the organic acid may be at least one of formic acid, acetic acid, and p-toluenesulfonic acid; further, the organic acid is acetic acid.

[0074] Specifically, the condensation reaction is carried out under reflux conditions for 6-12 hours, which can be further refined to 8-10 hours.

[0075] It is understood that the complexes obtained by the preparation method provided by this invention may contain impurities and can be purified, including the following steps:

[0076] (1) The complex shown in formula (1) is subjected to concentration treatment, precipitation treatment and solid-liquid separation treatment in sequence to obtain a solid phase;

[0077] (2) The solid phase was washed and dried to obtain the purified complex.

[0078] Specifically, the concentration process is used to remove volatile substances from the complex to obtain a concentrated solution;

[0079] The concentrated solution is added to an organic solvent for precipitation treatment. Further, the organic solvent is an anhydrous organic solvent. After precipitation treatment, solid-liquid separation is performed to obtain a solid phase.

[0080] The solid phase was washed with an anhydrous organic solvent; the purified complex was then obtained after drying.

[0081] Alternatively, the aniline compound shown in formula (2) can be prepared by the following method:

[0082] 2-R2-3-R4-5-R3-6-R1 aniline and 9-hydroxythioanthracene were mixed and stirred to melt under nitrogen at 120-140℃, and ZnCl2 in HCl solution was added dropwise to obtain an intermediate feedstock system. The intermediate feedstock system was heated at 120-140℃ for 2-4 hours, and after cooling, the solid was dissolved in dichloromethane (DCM) and washed three times with a saturated solution of ammonium chloride and sodium chloride. The organic fraction was collected by separating it through a separatory funnel and dried with anhydrous magnesium sulfate. Most of the solvent was removed, leaving the product dissolved in only a small amount of DCM. A large amount of n-heptane solvent was added for recrystallization to obtain a white crystalline solid, which is the aniline compound.

[0083] Thirdly, the present invention provides a catalyst comprising the complex of the first aspect or the complex prepared by the preparation method of the second aspect.

[0084] The catalyst provided by this invention can be used in ethylene polymerization to produce polyethylene products with high linearity and low molecular weight, and has excellent control over the structure of the polyethylene products; it can also make the obtained complexes more active, and synthesize products with high linearity, good heat resistance, and a weight-average molecular weight of 10-30 kg·mol⁻¹. -1 Polyethylene products between.

[0085] Furthermore, it also includes co-catalysts;

[0086] The co-catalyst includes methylaluminoxane, and the molar ratio of Al in methylaluminoxane to Co in the complex is (1000-3000):1.

[0087] The co-catalyst includes triisobutylaluminum-modified methylaluminoxane, wherein the molar ratio of Al in the triisobutylaluminum-modified methylaluminoxane to Co in the complex is (1000-2500):1;

[0088] The co-catalyst includes alkylaluminum, and the molar ratio of Al to Co in the complex is (200-2000):1.

[0089] The co-catalyst includes alkyl aluminum chloride, in which the molar ratio of Al to Co in the complex is (200-2000):1.

[0090] The catalyst provided by the present invention includes a main catalyst and a co-catalyst; the main catalyst is a complex of the first aspect or a complex prepared by the preparation method of the second aspect, and the co-catalyst includes at least one of aluminoxane, alkylaluminum and alkylaluminum chloride;

[0091] The aluminum oxane is methylaluminoxane (MAO) and / or triisobutylaluminum modified methylaluminoxane (MMAO);

[0092] The alkyl group in alkylaluminum and alkylaluminum chloride is selected from C10. 1-3 Alkyl group; alkyl aluminum chloride may be further selected from at least one of diethylaluminum chloride (Et2AlCl) and dimethylaluminum chloride (Me2AlCl);

[0093] Through long-term research by the inventors, it has been found that when the molar ratio of the metal Al element in the co-catalyst to the central metal Co element in the cobalt complex is (500-4000):1, the catalyst used in the ethylene polymerization reaction can produce polyethylene products with high linearity and low molecular weight, and further improve the control performance of the polyethylene product structure.

[0094] The above molar ratio can be further refined to (1000-3500):1, and in a specific embodiment, it is 1000:1, 1500:1, 1750:1, 2000:1, 2250:1, 2500:1, 2750:1, 3000:1, 3500:1;

[0095] In one specific embodiment, when the co-catalyst includes methylaluminoxane, the molar ratio of Al element in methylaluminoxane to Co element in the complex is (1000-3000):1;

[0096] In one specific embodiment, when the co-catalyst comprises triisobutylaluminum-modified methylaluminoxane, the molar ratio of Al element in the triisobutylaluminum-modified methylaluminoxane to Co element in the complex is (1000-2500):1;

[0097] In another specific embodiment, when the co-catalyst includes alkylaluminum, the molar ratio of Al element in the alkylaluminum to Co element in the complex is (200-2000):1;

[0098] In another specific embodiment, when the co-catalyst includes alkyl aluminum chloride, the molar ratio of Al element in alkyl aluminum chloride to Co element in the complex is (200-2000):1;

[0099] In the above specific embodiments, by further limiting the type of co-catalyst and the ratio of co-catalyst to complex when different types of co-catalysts are selected, the activity of the catalyst can be further improved, the linearity and heat resistance of the synthesized polyethylene product can be further improved, and the weight-average molecular weight can be further controlled within 10-30 kg·mol⁻¹. -1 between.

[0100] Fourthly, the present invention provides a complex of the first aspect, a complex obtained by the preparation method of the second aspect, and a catalyst of the third aspect in the application of catalytic olefin polymerization.

[0101] The application method provided by this invention can efficiently catalyze olefin polymerization to synthesize olefins with high linearity, good heat resistance, and a weight-average molecular weight of 10-30 kg·mol⁻¹. -1 Polyethylene products between.

[0102] Furthermore, the present invention does not specifically limit the reaction conditions for catalytic olefin polymerization; optionally, the reaction temperature can be 20-100℃, specifically 20℃, 30℃, 40℃, 50℃, 60℃, 70℃, 80℃, or 90℃, and further, the reaction temperature can be refined to 30-80℃; the polymerization reaction time can be 5-60 min, specifically 30 min; the polymerization reaction pressure can be 0.5-10 atm, specifically 10 atm; the solvent for the polymerization reaction can be selected from one or more of toluene, o-xylene, dichloromethane, ethanol, tetrahydrofuran, hexane, or cyclohexane.

[0103] The following is a detailed description of a cobalt complex provided by the present invention through specific embodiments.

[0104] Examples 1-4 and Comparative Example 1 were prepared using the following reaction procedure:

[0105]

[0106] Example 1

[0107] (1) Preparation of 2,6-dimethyl-4-thioxanthracene aniline (A1):

[0108] 2,6-Dimethylaniline (1.45 g, 12 mmol) and 9-hydroxythioxanthracene (3 g, 15 mmol) were placed in a 250 mL round-bottom flask. The mixture was stirred for 30 minutes at 130 °C under nitrogen, and then a catalytic amount of ZnCl2 in HCl solution was added dropwise. The reaction mixture was further heated for 2 hours, and after cooling, the solid was dissolved in DCM (200 mL). It was filtered and washed twice with a saturated solution of ammonium chloride and sodium chloride. The organic fraction was collected, dried over anhydrous Na2SO4, and concentrated under reduced pressure. The product was recrystallized from DCM using n-heptane to give a white crystalline solid (1.20 g, 33%).

[0109] The structural verification data is as follows:

[0110] 1 H NMR (400MHz, CDCl3, TMS): 1 H NMR (400MHz, CDCl3, TMS): δ7.68(d,J=3.8Hz,2H,Ar-H),7.33(t,J=3.8Hz,2H,Ar-H),7.03(t,J=7.0Hz,2H,Ar-H),6.98(s,2H,Ar-H m ),6.56(s,2H,-CH-)5.3(s,1H,-CH-),2.10(s,6H,-CH3).

[0111] 13C NMR (100MHz, CDCl3, TMS): δ145.5,140.9,134.0,133.2,130.8,128.8,127.9,127.7,127.3,122.1,51.9,17.9.

[0112] (2) Preparation of 2,6-bis[1-(4-thioxanthracene-2,6-dimethylphenylimino)ethyl]-pyridyl cobalt dichloride (Co-1):

[0113] The cobalt complex Co-1 was synthesized in a one-pot reaction. Schlenk tubes containing 2,6-diacetylpyridine (0.03 g, 0.20 mmol), 2,6-dimethyl-4-thioxanthylaniline (0.20 g, 0.60 mmol), and CoCl2 (0.02 g, 0.20 mmol) were refluxed with acetic acid (30 mL). The reaction was continued at 120 °C for 6 hours, and the evaporation was evaporated using a pump to obtain a concentrated solution. The cobalt complex was precipitated with diethyl ether (20 mL), filtered, washed with diethyl ether (3 × 15 mL), and separated into an air-stable green powder in good yield (0.15 g, 78%).

[0114] The structural verification data is as follows:

[0115] FT-IR (cm) -1 ):3310(w),2980(w)1652(ν(C=N),m),1495(w),1477(w),

[0116] 1436(w),1379(s),1380(s),1322(w),1303(w),1301(w),1250(s),1214(w),1148( w),1118(w),1118(w),1096(w),1032(w),946(w),879(m),811(w),751(s),658(w).

[0117] Elemental analysis: C 51 H 43 Theoretical values ​​for Cl2CoN3S2 (891.88%): C, 68.68; H, 4.86; N, 4.71%. Experimental values: C, 68.50; H, 5.05; N, 4.66.

[0118] Example 2

[0119] (1) Preparation of 2,6-diethyl-4-thioxanthracene aniline (A2):

[0120] 2,6-Diethylaniline (1.79 g, 12 mmol) and 9-hydroxythioxanthracene (3 g, 15 mmol) were placed in a 250 mL round-bottom flask. The mixture was stirred for 30 minutes at 130 °C under nitrogen, and then a catalytic amount of ZnCl2 in HCl solution was added dropwise. The reaction mixture was further heated for 2 hours, and after cooling, the solid was dissolved in DCM (200 mL). It was filtered and washed twice with a saturated solution of ammonium chloride and sodium chloride. The organic fraction was collected, dried over anhydrous Na2SO4, and concentrated under reduced pressure. The product was recrystallized from DCM using n-heptane to give a white crystalline solid (1.26 g, 38%).

[0121] The structural verification data is as follows:

[0122] 1 H NMR (400MHz, CDCl3, TMS): δ7.69 (d, J=3.8Hz, 2H, Ar-H), 7.33 (m, 2H, Ar-H), 6.96-7.03 (m, 4H, Ar-H), 6.88 (s, 2H, Ar-H m ),5.34(s,1H,-CH-),5.32(s,2H,NH2),2.58(m,4H,-CH2-),1.12(t,J=7.6Hz,6H,-CH3).

[0123] 13 C NMR (100MHz, CDCl3, TMS): δ145.5,139.7,134.0,133.2,130.8,128.8,127.9,127.7,126.8,126.0,51.9,23.7,14.5.

[0124] (2) Preparation of 2,6-bis[1-(4-thioxanthracene-2,6-diethylphenylimino)ethyl]-pyridyl cobalt dichloride (Co-2):

[0125] The cobalt complex Co-2 was synthesized in a one-pot reaction. Schlenk tubes containing 2,6-diacetylpyridine (0.03 g, 0.20 mmol), 2,6-diethyl-4-thioxanthylaniline (0.20 g, 0.60 mmol), and CoCl2 (0.02 g, 0.20 mmol) were refluxed with acetic acid (30 mL). The reaction was continued at 120 °C for 6 hours, and the evaporation was evaporated using a pump to obtain a concentrated solution. The cobalt complex was precipitated with diethyl ether (20 mL), filtered, washed with diethyl ether (3 × 15 mL), and separated into an air-stable green powder in good yield (0.17 g, 94%).

[0126] The structural verification data is as follows:

[0127] FT-IR (cm) -1 ):2932(w),2875(w),1623(ν(C=N),w),1576(m),1543(w),

[0128] 1478(s),1450(s),1371(w),1323(w),1301(w),1251(w),1211(m),1184(w),1 150(w),1118(w),1095(w),1030(w),981(w),940(w),881(m),808(w),749(s).

[0129] Elemental analysis: C 55 H 51 Theoretical values ​​for Cl2CoN3S2 (947.99%): C, 69.69%; H, 5.42%; N, 4.43%. Experimental values: C, 69.52%; H, 5.62%; N, 4.56%.

[0130] Example 3

[0131] (1) Preparation of 2,6-diisopropyl-4-thioxanthracene aniline (A3):

[0132] 2,6-Diisopropylaniline (2.12 g, 12 mmol) and 9-hydroxythioxanthracene (3 g, 15 mmol) were placed in a 250 mL round-bottom flask. The mixture was stirred for 30 minutes at 130 °C under nitrogen, and then a catalytic amount of ZnCl2 in HCl solution was added dropwise. The reaction mixture was further heated for 2 hours, and after cooling, the solid was dissolved in DCM (200 mL). It was filtered and washed twice with a saturated solution of ammonium chloride and sodium chloride. The organic fraction was collected, dried over anhydrous Na2SO4, and concentrated under reduced pressure. The product was recrystallized from DCM using n-heptane to give a white crystalline solid (1.30 g, 36%).

[0133] The structural verification data is as follows:

[0134] 1 H NMR (400MHz, CDCl3, TMS): δ7.69 (d, J=6.8Hz, 2H, Ar-H), δ7.33 (t, J=3.8Hz, 2H, Ar-H), 7.03-6.98 ( m,6H,Ar-H),5.34(s,1H,-CH-),5.32(s,2H,NH2),2.88(m,2H,-CH-),1.18(t,J=4.4Hz,12H,-CH3).

[0135] 13C NMR (100MHz, CDCl3, TMS): δ145.5,136.5,134.0,132.8,130.8,128.8,127.7,127.3,125.2,51.9,28.7,23.3.

[0136] (2) Preparation of 2,6-bis[1-(4-thioxanthracene-2,6-diisopropylphenylimino)ethyl]-pyridyl cobalt dichloride (Co-3):

[0137] The cobalt complex Co-3 was synthesized in a one-pot reaction. Schlenk tubes containing 2,6-diacetylpyridine (0.03 g, 0.20 mmol), 2,6-diisopropyl-4-thioxanthylaniline (0.21 g, 0.60 mmol), and CoCl2 (0.02 g, 0.20 mmol) were refluxed with acetic acid (30 mL). The reaction was continued at 120 °C for 6 hours, and the evaporation was evaporated using a pump to obtain a concentrated solution. The cobalt complex was precipitated with diethyl ether (20 mL), filtered, washed with diethyl ether (3 × 15 mL), and separated into an air-stable green powder in good yield (0.09 g, 53%).

[0138] The structural verification data is as follows:

[0139] FT-IR (cm) -1 ):2961(m),2868(w),1602(ν(C=N),w),1570(w),1550(w),

[0140] 1473(m),1449(s),1369(w),1303(w),1251(s),1211(w),1079(w),1028(w),944(w),833(w),812(w),751(s).

[0141] Elemental analysis: C 59 H 59 Theoretical values ​​for Cl2CoN3S2(1002.29): C, 70.58; H, 5.92; N, 4.18%. Experimental values: C, 70.40; H, 5.90; N, 4.19%.

[0142] Example 4

[0143] (1) Preparation of 2-methyl-6-ethyl-4-thioxanthracene aniline (A4):

[0144] 2-Methyl-6-ethylaniline (1.62 g, 12 mmol) and 9-hydroxythioxanthracene (3 g, 15 mmol) were placed in a 250 mL round-bottom flask. The mixture was stirred for 30 minutes at 130 °C under nitrogen, and then a catalytic amount of ZnCl2 in HCl solution was added dropwise. The reaction mixture was further heated for 2 hours, and after cooling, the solid was dissolved in DCM (200 mL). It was filtered and washed twice with a saturated solution of ammonium chloride and sodium chloride. The organic fraction was collected, dried over anhydrous Na2SO4, and concentrated under reduced pressure. The product was recrystallized from DCM using n-heptane to give a white crystalline solid (1.01 g, 32%).

[0145] The structural verification data is as follows:

[0146] 1 H NMR (400MHz, CDCl3, TMS): δ7.69(t,J=4.2Hz,2H,Ar-H),7.33(t,J=4.2Hz,2H,Ar-H),7.03-6.88(m,6H,Ar-H),6.56(t,J =4Hz,1H,Ar-H),5.34(s,1H,-CH-),5.32(s,2H,NH2),2.58(m,2H,-CH2-),2.12(s,3H,-CH3),1.39(t,J=4Hz,3H,-CH3).

[0147] 13 C NMR (100MHz, CDCl3, TMS): δ145.5,141.0,134.0,133.2,130.8,128.8,127.7,127.3 126.6,126.0,122.1,51.9,23.7,17.9,14.5.

[0148] (2) Preparation of 2,6-bis[1-(4-thioxanthracene-2-methyl-6-ethylphenylimino)ethyl]-pyridyl cobalt dichloride (Co-4):

[0149] The cobalt complex Co-4 was synthesized in a one-pot reaction. Schlenk tubes containing 2,6-diacetylpyridine (0.03 g, 0.20 mmol), 2-methyl-4-ethyl-4-thioxanthylaniline (0.19 g, 0.60 mmol), and CoCl2 (0.02 g, 0.20 mmol) were refluxed with acetic acid (30 mL). The reaction was continued at 120 °C for 6 hours, and the evaporation was evaporated using a pump to obtain a concentrated solution. The cobalt complex was precipitated with diethyl ether (20 mL), filtered, washed with diethyl ether (3 × 15 mL), and separated into an air-stable green powder in good yield (0.12 g, 53%).

[0150] The structural verification data is as follows:

[0151] FT-IR (cm) -1 ):2962(w),2284(w),2121(w),1604(ν(C=N),w),1543(m),

[0152] 1478(m),1448(s),1373(w),1304(w),1251(s),1210(w),1116(w),1095(w),1029(w),945(w),880(w),812(w),753(s).

[0153] Elemental analysis: C 53 H 47 Theoretical values ​​for Cl2CoN3S2(918.19): C, 69.20; H, 5.15; N, 4.57%. Experimental values: C, 69.16; H, 5.19; N, 4.62%.

[0154] Comparative Example 1

[0155] Preparation of 2,6-chloro-4-thionthaneaniline (A5):

[0156] 2,6-Dichloroaniline (1.94 g, 12 mmol) and 9-hydroxythioxanthracene (3 g, 15 mmol) were placed in a 250 mL round-bottom flask. The mixture was stirred for 30 minutes at 130 °C under nitrogen, and then a catalytic amount of ZnCl2 in HCl solution was added dropwise. The reaction mixture was further heated for 2 hours, and after cooling, the solid was dissolved in DCM (200 mL). It was filtered and washed twice with a saturated solution of ammonium chloride and sodium chloride. The organic fraction was collected, dried over anhydrous Na2SO4, and concentrated under reduced pressure. The product was recrystallized from DCM using n-heptane to give a white crystalline solid (1.30 g, 36%).

[0157] The structural verification data is as follows:

[0158] 1 H NMR (400MHz, CDCl3, TMS): δ7.69(t,J=3.8Hz,2H,Ar-H),7.33(t,J=3.8Hz,2H,Ar-H),7.09-6.98(m,6H,Ar-H),5.34(s,1H),5.32(s,2H,NH2).

[0159] 13 C NMR (100MHz, CDCl3, TMS): δ145.5,138.4,136.2,134.0,130.8,128.8 127.7,127.1,126.9,50.3.

[0160] (2) Preparation of 2,6-bis[1-(4-thioxanthracene-2,6-dichlorophenylimino)ethyl]-pyridyl cobalt dichloride (Co-5)

[0161] The cobalt complex Co-5 was synthesized in a one-pot reaction. Schlenk tubes containing 2,6-diacetylpyridine (0.03 g, 0.20 mmol), 2,6-dichloro-4-thioxanthylaniline (0.21 g, 0.60 mmol), and CoCl2 (0.02 g, 0.20 mmol) were refluxed with acetic acid (30 mL). The reaction was continued at 120 °C for 6 hours, and the evaporation was evaporated using a pump to obtain a concentrated solution. The cobalt complex was precipitated with diethyl ether (20 mL), filtered, washed with diethyl ether (3 × 15 mL), and separated into an air-stable green powder in good yield (0.30 g, 56%).

[0162] The structural verification data is as follows:

[0163] FT-IR (cm) -1 ):2962(w),1604(ν(C=N),w),1547(w),1478(m),1448(s),

[0164] 1371(w),1304(w),1251(s),1210(w),1116(w),1095(w),1028(w),944(w),880(w),812(w),752(s).

[0165] Elemental analysis: C 47 H 31 Theoretical values ​​for Cl6CoN3S2 (969.94%): C, 57.99%; H, 3.21%; N, 4.32%. Experimental values: C, 58.18%; H, 3.29%; N, 4.34%.

[0166] Experimental Example 1

[0167] Under an ethylene atmosphere, 25 mL of a toluene solution containing 1.5 μmol of catalysts Co-1 to Co-5 prepared in the above examples and comparative examples was injected into a 250 mL stainless steel autoclave equipped with a mechanical stirrer. Then, 25 mL of toluene was added, followed by the required amount of co-catalyst. Toluene was continued to be added until the total solvent volume reached 100 mL. Mechanical stirring was initiated and maintained at 400 rpm. When the polymerization temperature reached the set value, ethylene was introduced into the reactor, and the polymerization reaction began. The polymerization reaction was carried out at 30 °C with an ethylene pressure of 10 atm and stirred for 30 min. The reaction solution was neutralized with an ethanol solution acidified with 10% hydrochloric acid to obtain a polymer precipitate. This precipitate was washed several times with ethanol and dried under vacuum at 60 °C to constant weight to obtain the polymer.

[0168] The methylaluminoxane (MAO) and triisobutylaluminum-modified methylaluminoxane (MMAO) used were both purchased from AkzoNobel, USA. The Al / Co ratio below refers to the molar ratio of metallic Al in the co-catalyst MAO or MMAO to Co in the added main catalyst.

[0169] The experimental conditions for each experimental group are shown in Table 1.

[0170] Table 1

[0171]

[0172]

[0173] The weight-average molecular weight (Mb) of the polymers obtained in the above experimental groups was determined using the conventional high-temperature GPC method. w The melting temperature (T) was determined using conventional DSC methods. m );

[0174] The polymerization activity of the polymers was calculated according to the following formula: Polymer activity = Polymer yield / (Catalyst dosage * Polymerization time); The test results are shown in Table 2;

[0175] Table 2

[0176]

[0177] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A cobalt complex, characterized in that, It has the structure shown in equation (1): Each X is independently selected from at least one of F, Cl, Br, and I; R 1 R 2 R 3 R 4 R 5 Each is independently selected from H and R. a C with or without substitution 1-6 Alkyl, R a C with or without substitution 1-6 Alkyl groups, by R a C with or without substitution 6-20 Aryl, R a C with or without substitution 6-20 heteroatomic aryl; Each R a Each is independently selected from F, Cl, Br, I, and C. 1-6 Alkyl, C 1-6 Alkoxy, C 3-10 Heterocyclic group, C 6-20 Aryl or C 6-20 Heteroatomic aryl group.

2. The complex according to claim 1, characterized in that, R 1 Selected from C 1-3 alkyl.

3. The complex according to claim 1 or 2, characterized in that, R 2 Selected from C 1-3 alkyl.

4. The complex according to claim 3, characterized in that, R 3 R 4 Each is independently selected from H or C 1-6 alkyl.

5. The complex according to claim 1, characterized in that, R 1 and R 2 All are methyl groups, X is Cl, R 3 R 4 R 5 All are H; or, R 1 and R 2 All are ethyl groups, X is Cl, and R is... 3 R 4 R 5 All are H; or, R 1 and R 2 All are isopropyl, X is Cl, R 3 R 4 R 5 All are H; or, R 1 For methyl, R 2 For ethyl, X is Cl, R 3 R 4 R 5 All are H.

6. A method for preparing the complex according to any one of claims 1-5, characterized in that, Includes the following steps: 2,6-Diacetylpyridine was condensed with an aniline compound as shown in formula (2) and compound CoX2 to obtain the complex shown in formula (1); Each X is independently selected from at least one of F, Cl, Br, and I; R 1 R 2 R 3 R 4 R 5 Each is independently selected from H and R. a C with or without substitution 1-6 Alkyl, R a C with or without substitution 1-6 Alkyl groups, by R a C with or without substitution 6-20 Aryl, R a C with or without substitution 6-20 heteroatomic aryl; Each R a Each is independently selected from F, Cl, Br, I, and C. 1-6 Alkyl, C 1-6 Alkoxy, C 3-10 Heterocyclic group, C 6-20 Aryl or C 6-20 Heteroatomic aryl group.

7. The preparation method according to claim 6, characterized in that, The molar ratio of the compound CoX2 to the aniline compound is 1:(2-3).

8. A catalyst, characterized in that, This includes the complexes described in any one of claims 1-5 or the complexes prepared by the method described in claim 6 or 7.

9. The catalyst according to claim 8, characterized in that, It also includes co-catalysts; The co-catalyst comprises methylaluminoxane, wherein the molar ratio of Al in the methylaluminoxane to Co in the complex is (1000-3000):1; and / or, The cocatalyst comprises triisobutylaluminum-modified methylaluminoxane, wherein the molar ratio of Al in the triisobutylaluminum-modified methylaluminoxane to Co in the complex is (1000-2500):1; and / or, The co-catalyst comprises alkylaluminum, wherein the molar ratio of Al to Co in the complex is (200-2000):1; and / or, The co-catalyst includes alkyl aluminum chloride, wherein the molar ratio of Al to Co in the complex is (200-2000):

1.

10. The use of a complex according to any one of claims 1-5, a complex prepared by the preparation method according to claim 6 or 7, and a catalyst according to claim 8 or 9 in the catalytic polymerization of olefins.

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