Synthesis methods, products and applications of non-bridging symmetric metallocene catalysts

Abstract

This invention discloses a method for synthesizing a non-bridged symmetric metallocene catalyst, its product, and its applications. The method uses group IV metal chlorides, C1-C3 alkyl metal reagents, and cyclopentadiene derivatives as raw materials, reacting them in an organic solvent under nitrogen or argon atmosphere. This invention has advantages such as fewer reaction steps, simple operation, high efficiency, and broad substrate applicability.

Description

TECHNICAL FIELD

[0001] The present application relates to a method for synthesizing a non-bridged symmetrical metallocene catalyst, its product and application. BACKGROUND

[0002] Metallocene compound generally refers to a kind of organic complex composed of transition metal or rare earth metal and at least one cyclopentadiene or its derivative as ligand. Two identical metallocene rings are coordinated with the central metal atom, thereby forming a sandwich structure, i.e. the so-called non-bridged symmetrical bimetallic catalyst, such as Cp2MCl2, (Ind)2MCl2 (M is titanium, zirconium, hafnium; Cp is cyclopentadienyl; Ind is indenyl).

[0003] At present, there are two methods for effectively synthesizing non-bridged symmetrical metallocene catalyst. Method 1: cyclopentadiene derivative is reacted with a strong basic compound to generate a cyclopentadiene ligand salt, and then the ligand salt is reacted with a transition metal halide or its complex to obtain the catalyst; Method 2: cyclopentadiene derivative is first reacted with a strong basic compound to generate a cyclopentadiene ligand salt, then reacted with trimethylchlorosilane to obtain a trimethylsilyl cyclopentadiene derivative, and finally reacted with a transition metal halide to obtain the target product.

[0004] The above methods can effectively prepare non-bridged symmetrical metallocene catalysts, but have the disadvantages of multiple reaction steps and complicated operation. Since the solubility of cyclopentadiene derivative ligand salt or transition metal halide in organic solvent is poor, solid feeding or slurry feeding is often required in the reaction process, and the reaction needs to be carried out under anhydrous and anaerobic conditions, which further increases the difficulty and safety risk of reaction operation.

[0005] In 2001, Eisch et al. (Organometallics 2001, 20, 4132-4134.) reported a new method for the preparation of non-bridged symmetrical metallocene compounds. The method uses a one-pot two-step process, first by reacting 2 equivalents of n-butyllithium with zirconium tetrachloride to obtain zirconium dibutyl dichloride, and then by reacting with 2 equivalents of cyclopentadiene to obtain bis(cyclopentadienyl)zirconium dichloride with a yield of more than 95%. Compared with the traditional method, the process has the advantages of fewer reaction steps, simple operation, and low safety risk. However, in the process of applying the method to the synthesis of symmetrical metallocene compounds, it was found that although the process can effectively prepare bis(cyclopentadienyl)zirconium dichloride, bis(indenyl)zirconium dichloride, and bis(methylcyclopentadienyl)zirconium dichloride, the reaction results are poor for preparing non-bridged symmetrical metallocene compounds such as bis(pentamethylcyclopentadienyl)zirconium dichloride, bis(2-phenylindenyl)zirconium dichloride, bis(1-methylindenyl)zirconium dichloride, bis(trimethylsilylcyclopentadienyl)zirconium dichloride, bis(pentamethylcyclopentadienyl)zirconium dichloride, or bis(pentamethylcyclopentadienyl)hafnium dichloride, with a yield of only 20-35%. SUMMARY

[0006] In order to at least partially solve the technical defects existing in the prior art, the inventors have made the present application.

[0007] As an aspect of the present application, a method for preparing a non-bridged symmetrical metallocene catalyst is provided, which uses a fourth sub-group metal chloride, a C1-C3 alkyl metal reagent, and a cyclopentadiene derivative as raw materials, and reacts in an organic solvent under a nitrogen or argon environment to obtain a non-bridged symmetrical metallocene catalyst through a one-pot two-step reaction.

[0008] Specifically, the method for preparing a non-bridged symmetrical metallocene catalyst comprises:

[0009] (1) first adding 2 equivalents of a C1-C3 alkyl metal reagent to a mixture of a fourth sub-group metal chloride and an organic solvent at a certain feeding temperature, and reacting at room temperature to obtain a mixture;

[0010] (2) adding 2 equivalents of a cyclopentadiene derivative to the mixture obtained in step (1) at a certain feeding temperature, and reacting at a certain reaction temperature.

[0011] In a specific embodiment, the fourth sub-group metal chloride has a general formula of MCl4, wherein M is elemental titanium, zirconium, or hafnium.

[0012] In a specific embodiment, the C1-C3 alkyl metal reagent is RLi, R2Zn, or RMgX; wherein R is a C1-C3 normal alkyl group, and X is a halogen chloride, bromine, or iodine.

[0013] In one specific embodiment, the cyclopentadiene derivative may be selected from the following compounds:

[0014]

[0015] Among them, R 1 For alkyl, benzyl, or trimethylsilyl groups with C2-C4 carbon chains; n is an integer from 2 to 5; when R 3 When it is hydrogen, R 2 It can be an alkyl, benzyl, or trimethylsilyl group with a C1-C4 carbon chain; when R 2 When it is hydrogen, R 3 It can be an alkyl, benzyl, phenyl, 4-methylphenyl, or 4-methoxyphenyl group with a C1-C4 carbon chain; R 2 and R 3 It can be both methyl and ethyl; R 4 It can be hydrogen, methyl, or phenyl.

[0016] In one specific embodiment, the certain feeding temperature is -78 to 0 degrees Celsius, preferably -40 to -10 degrees Celsius; the certain reaction temperature is 25 to 140 degrees Celsius, preferably 60 to 110 degrees Celsius.

[0017] In one specific embodiment, the organic solvent is n-hexane, n-heptane, toluene, o-xylene, tetrahydrofuran, 2-methyltetrahydrofuran, diethyl ether, or ethylene glycol dimethyl ether.

[0018] In one specific implementation, the reaction time for step (1) is 4-8 hours; the reaction time for step (2) is 5-10 hours.

[0019] As another aspect of the present invention, it relates to a non-bridged symmetric metallocene catalyst prepared by the above method.

[0020] As another aspect of the present invention, the application of the above-mentioned non-bridged symmetric metallocene catalysts in olefin polymerization reactions is involved.

[0021] As another aspect of the invention, there is a connection to an olefin polymerization reaction using the non-bridged symmetric metallocene catalyst of claim 10. Specifically, the olefin polymerization reaction is a 1-decene polymerization reaction.

[0022] The di-n-butyl dichloro metal intermediate obtained during the reaction is unstable and easily decomposes into a dichloro metal compound. This compound cannot continue to react with the cyclopentadiene derivative to obtain the target product. When using polysubstituted cyclopentadiene derivatives or trimethylsilylcyclopentadiene derivatives for the preparation of symmetrical metallocene compounds, the electronic effects and steric hindrance of the substituents affect the reactivity of the cyclopentadiene derivatives. When the reactivity of the cyclopentadiene derivative is low, the probability of side reactions increases, resulting in the formation of dichloro metal compounds, which prevents the target reaction from occurring and leads to a low product yield.

[0023] Through reaction process exploration, we found that using C1-C3 alkyl metal reagents such as methyllithium, ethyllithium, methylmagnesium chloride, ethylmagnesium chloride, propylmagnesium chloride, or diethylzinc increases the stability of dialkyl metal intermediates and reduces the probability of side reactions, thereby improving the yield of the target product, the non-bridged symmetric metallocene compound, and expanding the substrate applicability of the original method.

[0024] This invention uses Group IV submetal chlorides, C1-C3 alkyl metal reagents, and cyclopentadiene derivatives as raw materials to prepare non-bridged symmetric metallocene catalysts through a one-pot, two-step reaction at a certain temperature under nitrogen or argon atmosphere. It has the advantages of fewer reaction steps, simple operation, high efficiency, and strong substrate applicability. Detailed Implementation

[0025] The embodiments of the present invention will be described in detail below with reference to examples. However, those skilled in the art will understand that the following examples are for illustrative purposes only and should not be considered as limiting the scope of the invention. Where specific conditions are not specified in the examples, they are performed under conventional conditions or conditions recommended by the manufacturer. Reagents, instruments, or methods used in the embodiments of the present invention whose source is not specified are all conventional products that can be obtained commercially or from the applicant. Invention Overview:

[0027] This invention employs a one-pot, two-step reaction in a nitrogen or argon atmosphere and an organic solvent. The first step involves adding 2 equivalents of a C1-C3 alkyl metal reagent (RM') to a mixture of a Group IV submetal chloride and a solvent at a specific feeding temperature, and reacting at room temperature to prepare a dialkyl metal intermediate. The second step involves adding 2 equivalents of a cyclopentadiene derivative (Cp'H) to the dialkyl metal intermediate without separation or purification, and reacting at a specific temperature to prepare a non-bridged symmetric metallocene catalyst. The synthetic route is shown in the following reaction formula:

[0028]

[0029] The preferred technical solution to the problem solved by this invention is as follows:

[0030] In one specific embodiment, the general formula of the fourth subgroup metal chloride is MCl4, where M is the element titanium, zirconium, or hafnium.

[0031] In one specific embodiment, the alkyl metal reagent (RM') is alkyl lithium (RLi), dialkyl zinc (R2Zn), or alkyl magnesium halide (RMgX); wherein R is a C1-C3 normal alkyl group, and X is a halogen chlorine, bromine, or iodine.

[0032] In one specific embodiment, the cyclopentadiene derivative (Cp'H) is a monosubstituted cyclopentadiene, a polymethyl substituted cyclopentadiene, a polysubstituted indene, or a fluorene, with the following structural formula:

[0033]

[0034] Among them, R 1 For alkyl, benzyl, or trimethylsilyl groups with C2-C4 carbon chains; n is an integer from 2 to 5; when R 3 When it is hydrogen, R 2 It can be an alkyl, benzyl, or trimethylsilyl group with a C1-C4 carbon chain; when R 2 When it is hydrogen, R 3 It can be an alkyl, benzyl, phenyl, 4-methylphenyl, or 4-methoxyphenyl group with a C1-C4 carbon chain; R 2 and R 3 It can be both methyl and ethyl; R 4 It can be hydrogen, methyl, or phenyl.

[0035] In one specific embodiment, the feeding temperature is -78 to 0 degrees Celsius, preferably -40 to -10 degrees Celsius; the reaction temperature is 25 to 140 degrees Celsius, preferably 60 to 110 degrees Celsius.

[0036] In one specific embodiment, the organic solvent is n-hexane, n-heptane, toluene, o-xylene, tetrahydrofuran, 2-methyltetrahydrofuran, diethyl ether, or ethylene glycol dimethyl ether.

[0037] In one specific implementation, the reaction time for the first step is 4-8 hours; the reaction time for the second step is 5-10 hours.

[0038] Example 1

[0039] Step 1: Under nitrogen atmosphere, zirconium tetrachloride (2.33 g, 10 mmol) was added to toluene (80 mL). At -78°C (addition temperature), a methyllithium / 2-methyltetrahydrofuran solution (1.0 mol / L) (20 mL) was added. The reaction system was heated to room temperature (25°C) and stirred for 4 hours to obtain a dialkyl metal intermediate. Step 2: The dialkyl metal intermediate did not need to be separated. At -78°C (addition temperature), pentamethylcyclopentadiene (2.72 g, 20 mmol) was added to the mixture. After addition, the reaction system was heated to room temperature (25°C), then to 110°C (reaction temperature) and the reaction continued for 10 hours. After the reaction was completed, the mixture was cooled to room temperature and then subjected to post-processing: filtration, vacuum distillation, recrystallization, and vacuum drying to obtain a pale yellow powdery solid, which was the target product bis(pentamethylcyclopentadienyl)zirconium dichloride 1a (3.67 g, yield 85%).

[0040] Example 2

[0041] The reaction steps and operations were the same as in Example 1, except that the gas environment was argon. The reaction was stopped, and the target product 1a (3.76 g, yield 87%) was obtained after post-processing.

[0042] Example 3

[0043] The reaction steps and operations were the same as in Example 1, except that the reaction solvent was o-xylene. The reaction was stopped, and the target product 1a (3.61 g, yield 84%) was obtained after post-treatment.

[0044] Example 4

[0045] The reaction steps and operations were the same as in Example 1, except that the reaction solvent was n-heptane and the reaction temperature was 98 degrees Celsius. The reaction was stopped, and after post-treatment, the target product 1a (3.76 g, yield 87%) was obtained.

[0046] Example 5

[0047] The reaction steps and operations were the same as in Example 1, except that the reaction solvent was n-hexane and the reaction temperature was 69 degrees Celsius. The reaction was stopped, and after post-treatment, the target product 1a (3.33 g, yield 77%) was obtained.

[0048] Example 6

[0049] The reaction steps and operations were the same as in Example 1, except that the reaction solvent was tetrahydrofuran and the reaction temperature was 66 degrees Celsius. The reaction was stopped, and after post-treatment, the target product 1a (3.24 g, yield 75%) was obtained.

[0050] Example 7

[0051] The reaction steps and operations were the same as in Example 1, except that the reaction solvent was diethyl ether and the reaction temperature was 25 degrees Celsius. The reaction was stopped, and after post-treatment, the target product 1a (1.86 g, yield 43%) was obtained.

[0052] Example 8

[0053] The reaction steps and operations were the same as in Example 1, except that the reaction time in the first step was 8 hours. The reaction was stopped, and the target product 1a (3.80 g, yield 88%) was obtained after post-processing.

[0054] Example 9

[0055] The reaction steps and operations were the same as in Example 1, except that the reaction time in the second step was 5 hours. The reaction was stopped, and the target product 1a (2.72 g, yield 63%) was obtained after post-processing.

[0056] Example 10

[0057] The reaction steps and operations were the same as in Example 8, except that the reaction time in the second step was 5 hours. The reaction was stopped, and the target product 1a (2.94 g, yield 68%) was obtained after post-processing.

[0058] Example 11

[0059] The reaction steps and operations were the same as in Example 1, except that the feeding temperature was -40 degrees Celsius. The reaction was stopped, and the target product 1a (3.54 g, yield 82%) was obtained after post-processing.

[0060] Example 12

[0061] The reaction steps and operations were the same as in Example 1, except that the feeding temperature was -10 degrees Celsius. The reaction was stopped, and the target product 1a (3.19 g, yield 74%) was obtained after post-processing.

[0062] Example 13

[0063] The reaction steps and operations were the same as in Example 1, except that the feeding temperature was 0 degrees Celsius. The reaction was stopped, and the target product 1a (2.82 g, yield 65%) was obtained after post-processing.

[0064] Example 14

[0065] The reaction steps and operations were the same as in Example 1, except that the reaction temperature was 25 degrees Celsius. The reaction was stopped, and the target product 1a (1.73 g, yield 40%) was obtained after post-processing.

[0066] Example 15

[0067] The reaction steps and operations were the same as in Example 1, except that the reaction temperature was 60 degrees Celsius. The reaction was stopped, and the target product 1a (3.07 g, yield 71%) was obtained after post-processing.

[0068] Example 16

[0069] The reaction steps and operations were the same as in Example 1, except that the reaction solvent was o-xylene and the reaction temperature was 140 degrees Celsius. The reaction was stopped, and after post-treatment, the target product 1a (3.73 g, yield 86%) was obtained.

[0070] Example 17

[0071] The reaction procedure and operation were the same as in Example 1, except that the alkyl metal reagent was a dimethyl zinc / n-hexane solution (1.0 mol / L) (20 mL). The reaction was stopped, and the target product 1a (3.76 g, yield 87%) was obtained after post-treatment.

[0072] Example 18

[0073] The reaction procedure and operation were the same as in Example 1, except that the alkyl metal reagent was an ethyllithium / cyclohexane solution (0.5 mol / L) (40 mL). The reaction was stopped, and the target product 1a (3.16 g, yield 73%) was obtained after post-treatment.

[0074] Example 19

[0075] The reaction procedure and operation were the same as in Example 1, except that the alkyl metal reagent was a diethylzinc / n-hexane solution (1.0 mol / L) (20 mL). The reaction was stopped, and the target product 1a (3.02 g, yield 70%) was obtained after post-treatment.

[0076] Example 20

[0077] The reaction procedure and operation were the same as in Example 1, except that the alkyl metal reagent was a 1.0 mol / L (20 mL) solution of n-propyllithium / n-hexane. The reaction was stopped, and the target product 1a (2.73 g, yield 63%) was obtained after post-treatment.

[0078] Example 21

[0079] The reaction procedure and operation were the same as in Example 1, except that the alkyl metal reagent was a methylmagnesium iodide / diethyl ether solution (3.0 mol / L) (6.68 mL). The reaction was stopped, and after post-treatment, the target product 1a (3.58 g, yield 83%) was obtained.

[0080] Example 22

[0081] The reaction procedure and operation were the same as in Example 1, except that the alkyl metal reagent was a methyl magnesium chloride / tetrahydrofuran solution (3.0 mol / L) (6.68 mL). The reaction was stopped, and after post-treatment, the target product 1a (3.72 g, yield 86%) was obtained.

[0082] Example 23

[0083] The reaction procedure and operation were the same as in Example 1, except that the alkyl metal reagent was a methyl magnesium bromide / tetrahydrofuran solution (3.0 mol / L) (6.68 mL). The reaction was stopped, and after post-treatment, the target product 1a (3.50 g, yield 81%) was obtained.

[0084] Example 24

[0085] The reaction procedure and operation were the same as in Example 1, except that the alkyl metal reagent was an ethyl magnesium bromide / tetrahydrofuran solution (1.0 mol / L) (20 mL). The reaction was stopped, and the target product 1a (3.02 g, yield 70%) was obtained after post-treatment.

[0086] Example 25

[0087] The reaction procedure and operation were the same as in Example 1, except that the alkyl metal reagent was n-propylmagnesium chloride / diethyl ether solution (2.0 mol / L) (10 mL). The reaction was stopped, and the target product 1a (2.68 g, yield 62%) was obtained after post-treatment.

[0088] Example 26

[0089] The reaction procedure and operation were the same as in Example 1, except that the fourth subgroup metal chloride was titanium tetrachloride (1.90 g, 10 mmol). The reaction was stopped, and the target product 1b (2.49 g, yield 64%) was obtained after post-treatment.

[0090] Example 27

[0091] The reaction steps and operations were the same as in Example 1, except that the fourth subgroup metal chloride was hafnium tetrachloride (3.20 g, 10 mmol). The reaction was stopped, and the target product 1c (3.80 g, 73% yield) was obtained after post-processing.

[0092] Example 28

[0093] The reaction procedure and operation were the same as in Example 1, except that the cyclopentadiene derivative (Cp'H) was 5-trimethylsilylcyclopentadiene (2.76 g, 20 mmol). The reaction was stopped, and the target product 1d (3.84 g, 88% yield) was obtained after post-treatment.

[0094] Example 29

[0095] The reaction procedure and operation were the same as in Example 1, except that the cyclopentadiene derivative (Cp'H) was 5-n-butylcyclopentadiene (2.44 g, 20 mmol). The reaction was stopped, and the target product 1e (3.03 g, 75% yield) was obtained after post-treatment.

[0096] Example 30

[0097] The reaction procedure and operation were the same as in Example 1, except that the cyclopentadiene derivative (Cp'H) was 5-benzylcyclopentadiene (3.12 g, 20 mmol). The reaction was stopped, and the target product 1f (3.44 g, 73% yield) was obtained after post-treatment.

[0098] Example 31

[0099] The reaction procedure and operation were the same as in Example 1, except that the cyclopentadiene derivative (Cp'H) was 1,2-dimethyl-1,3-cyclopentadiene (1.88 g, 20 mmol). The reaction was stopped, and after post-treatment, 1 g (3.03 g, yield 87%) of the target product was obtained.

[0100] Example 32

[0101] The reaction procedure and operation were the same as in Example 1, except that the cyclopentadiene derivative (Cp'H) was 1,3-dimethyl-1,3-cyclopentadiene (1.88 g, 20 mmol). The reaction was stopped, and the target product was obtained after post-treatment (3.06 g, yield 88%).

[0102] Example 33

[0103] The reaction procedure and operation were the same as in Example 1, except that the cyclopentadiene derivative (Cp'H) was fluorene (3.32 g, 20 mmol). The reaction was stopped, and the target product 1i (2.95 g, 60% yield) was obtained after post-processing.

[0104] Example 34

[0105] The reaction procedure and operation were the same as in Example 1, except that the cyclopentadiene derivative (Cp'H) was 2-phenylindene (3.84 g, 20 mmol). The reaction was stopped, and the target product 1j (3.92 g, 72% yield) was obtained after post-treatment.

[0106] Example 35

[0107] The reaction procedure and operation were the same as in Example 1, except that the cyclopentadiene derivative (Cp'H) was 1-methylindene (2.60 g, 20 mmol). The reaction was stopped, and the target product 1k (2.94 g, 70% yield) was obtained after post-treatment.

[0108] Example 36

[0109] The reaction procedure and operation were the same as in Example 1, except that the cyclopentadiene derivative (Cp'H) was 1-trimethylsilylindene (3.77 g, 20 mmol). The reaction was stopped, and the target product 1l (3.87 g, yield 72%) was obtained after post-treatment.

[0110] Example 37

[0111] The reaction procedure and operation were the same as in Example 1, except that the cyclopentadiene derivative (Cp'H) was 1,2,3-trimethyl-1,3-cyclopentadiene (2.16 g, 20 mmol). The reaction was stopped, and the target product 1m (3.12 g, yield 83%) was obtained after post-treatment.

[0112] Example 38

[0113] The reaction procedure and operation were the same as in Example 1, except that the cyclopentadiene derivative (Cp'H) was 1,2,4-trimethyl-1,3-cyclopentadiene (2.16 g, 20 mmol). The reaction was stopped, and the target product 1n (3.20 g, 85% yield) was obtained after post-treatment.

[0114] Example 39

[0115] The reaction procedure and operation were the same as in Example 1, except that the cyclopentadiene derivative (Cp'H) was 1,2,3,4-tetramethyl-1,3-cyclopentadiene (2.44 g, 20 mmol). The reaction was stopped, and the target product 1o (3.60 g, 89% yield) was obtained after post-treatment.

[0116] Example 40

[0117] The reaction procedure and operation were the same as in Example 1, except that the cyclopentadiene derivative (Cp'H) was 5-ethylcyclopentadiene (1.88 g, 20 mmol). The reaction was stopped, and the target product 1p (2.51 g, yield 72%) was obtained after post-treatment.

[0118] Example 41

[0119] The reaction procedure and operation were the same as in Example 1, except that the cyclopentadiene derivative (Cp'H) was 1-n-butylindene (3.44 g, 20 mmol). The reaction was stopped, and the target product 1q (3.58 g, 71% yield) was obtained after post-treatment.

[0120] Example 42

[0121] The reaction procedure and operation were the same as in Example 1, except that the cyclopentadiene derivative (Cp'H) was 1-benzylindene (4.12 g, 20 mmol). The reaction was stopped, and the target product 1r (3.90 g, yield 68%) was obtained after post-treatment.

[0122] Example 43

[0123] The reaction procedure and operation were the same as in Example 1, except that the cyclopentadiene derivative (Cp'H) was 2-n-butylindene (3.44 g, 20 mmol). The reaction was stopped, and after post-treatment, the target product 1s (3.28 g, 65% yield) was obtained.

[0124] Example 44

[0125] The reaction procedure and operation were the same as in Example 1, except that the cyclopentadiene derivative (Cp'H) was 2-benzylindene (4.12 g, 20 mmol). The reaction was stopped, and after post-treatment, 1 t (4.01 g, 70% yield) of the target product was obtained.

[0126] Example 45

[0127] The reaction procedure and operation were the same as in Example 1, except that the cyclopentadiene derivative (Cp'H) was 2-(4-methoxyphenyl)indene (4.44 g, 20 mmol). The reaction was stopped, and after post-treatment, the target product 1u (4.54 g, yield 75%) was obtained.

[0128] Example 46

[0129] The reaction procedure and operation were the same as in Example 1, except that the cyclopentadiene derivative (Cp'H) was 2-(4-methylphenyl)indene (4.12 g, 20 mmol). The reaction was stopped, and the target product 1v (4.13 g, 72% yield) was obtained after post-treatment.

[0130] Example 47

[0131] The reaction procedure and operation were the same as in Example 1, except that the cyclopentadiene derivative (Cp'H) was 1,2-dimethylindene (2.88 g, 20 mmol). The reaction was stopped, and after post-treatment, the target product 1w (2.92 g, yield 65%) was obtained.

[0132] Example 48

[0133] The reaction procedure and operation were the same as in Example 1, except that the cyclopentadiene derivative (Cp'H) was 1,2,5-trimethylindene (3.16 g, 20 mmol). The reaction was stopped, and after post-treatment, the target product 1x (3.57 g, 75% yield) was obtained.

[0134] Example 49

[0135] The reaction procedure and operation were the same as in Example 1, except that the cyclopentadiene derivative (Cp'H) was 1,2-dimethyl-5-phenylindene (4.41 g, 20 mmol). The reaction was stopped, and the target product 1y (3.67 g, yield 61%) was obtained after post-treatment.

[0136] Example 50

[0137] The reaction procedure and operation were the same as in Example 1, except that the cyclopentadiene derivative (Cp'H) was cyclopentadiene (1.32 g, 20 mmol). The reaction was stopped, and the target product 1z (2.81 g, 96% yield) was obtained after post-processing.

[0138] Example 51

[0139] The reaction procedure and operation were the same as in Example 1, except that the cyclopentadiene derivative (Cp'H) was indene (2.32 g, 20 mmol). The reaction was stopped, and the target product 1aa (2.76 g, 70% yield) was obtained after post-treatment.

[0140] Example 52

[0141] The reaction procedure and operation were the same as in Example 5, except that the cyclopentadiene derivative (Cp'H) was indene (2.32 g, 20 mmol). The reaction was stopped, and the target product 1aa (3.36 g, 86% yield) was obtained after post-processing.

[0142] Compare with Example 1

[0143] The preparation of bis(pentamethylcyclopentadienyl)zirconium dichloride 1a was carried out according to the method described in reference (Organometallics 2001, 20, 4132-4134). Reaction steps: First reaction: Under nitrogen atmosphere, zirconium tetrachloride (2.33 g, 10 mmol) was added to toluene (80 mL). At -78°C, a 2.5 mol / L solution of n-butyllithium / n-hexane (8 mL) was added, and the system was slowly restored to 20°C over 8 hours. Second reaction: The reaction system was cooled again to -78°C, and pentamethylcyclopentadiene (3.40 g, 25 mmol) was added to the mixture. After the addition was complete, the reaction system was stirred at -78°C for 1 hour, then restored to room temperature and heated to 110°C, and stirred for another 4 hours. After the reaction was completed, the mixture was cooled to room temperature and then subjected to post-processing: filtration, vacuum distillation, recrystallization, and vacuum drying to obtain a pale yellow powdery solid, which was the target product, bis(pentamethylcyclopentadienyl)zirconium dichloride 1a (0.86 g, yield 20%).

[0144] Compare with Example 2

[0145] The reaction procedure and operation were the same as in Control Example 1, except that the reaction solvent was n-hexane (80 mL), and the second step reaction was continued at 69 degrees Celsius for 4 hours. The reaction was stopped, and the target product 1a (0.43 g, yield 10%) was obtained after post-processing.

[0146] Compare with Example 3

[0147] The reaction procedure and operation were the same as in Control Example 1, except that the reaction solvent was n-hexane (80 mL), and the second step reaction was continued at 69 degrees Celsius for 10 hours. The reaction was stopped, and the target product 1a (0.52 g, yield 12%) was obtained after post-treatment.

[0148] Compare with Example 4

[0149] The reaction procedure and operation were the same as in Control Example 1, except that the second step reaction was continued at 110 degrees Celsius for 10 hours. The reaction was then stopped, and the target product 1a (1.38 g, yield 32%) was obtained after post-processing.

[0150] Comparative Examples 5 to 6

[0151] The reaction steps and operations are the same as in Control Example 4, except that a Group 4 submetal chloride is used instead.

[0152] Comparative Example Fourth transition metal chlorides (MCl4) Product Yield (%) 5 Titanium tetrachloride (1.90 g, 10 mmol) 1b 13 6 Hafnium tetrachloride (3.20 g, 10 mmol) 1c 28

[0153] Comparative Examples 7 to 20

[0154] The reaction steps and operations are the same as in Control Example 4, except that a cyclopentadiene derivative (Cp'H) is used:

[0155] Comparative Example Cyclopentadiene derivative (Cp'H) Product Yield (%) 7 5-Trimethylsilyleyclopetadiene (2.76 g, 20 mmol) 1d 27 8 5-Benzylcyclopentadiene (3.12 g, 20 mmol) 1f 22 9 1,3-Dimethyl-1,3-cyclopentadiene (1.88 g, 20 mmol) 1h 33 10 Fluorene (3.32 g, 20 mmol) 1i 17 11 2-Phenylindene (3.84 g, 20 mmol) 1j 32 12 1-Methylindene (2.60 g, 20 mmol) 1k 35 13 1-Trimethylsilylindene (3.77 g, 20 mmol) 1l 33 14 1,2,4-Trimethyl-1,3-cyclopentadiene (2.16 g, 20 mmol) 1n 28 15 1,2,3,4-Tetramethyl-1,3-cyclopentadiene (2.44 g, 20 mmol) 1o 33 16 1-n-Butylindene (3.44 g, 20 mmol) 1q 27 17 1-Benzylindene (4.12 g, 20 mmol) 1r 28 18 2-n-Butylindene (3.44 g, 20 mmol) 1s 25 19 1,2-Dimethylindene (2.88 g, 20 mmol) 1w 21 20 1,2,5-Trimethylindene (3.16 g, 20 mmol) 1x 20

[0156] Application Example 1

[0157] Using non-bridged symmetric metallocene complexes as catalysts can effectively promote the oligomerization of 1-decene, yielding low-viscosity poly-α-olefin products. Specific applications are as follows:

[0158] Preparation of metallocene catalyst: Weigh bis(1-methylindenyl)zirconium dichloride (1k) (13.5 mg, 0.032 mmol) and dissolve it in 10 ml toluene solution (metallocene amount 0.0086 mol%). Add 6.0 ml of 1.5 M methylaluminoxane toluene solution (co-catalyst) (co-catalyst / (metallocene (1k) = 281 (molar ratio)), stir for 30 minutes and set aside.

[0159] Polymerization reaction: A 250 mL Schlenk reaction flask was evacuated and purged with nitrogen three times. Under nitrogen conditions, 1-decene (70 mL, 51.9 g, 370 mmol) that had been treated to be anhydrous and oxygen-free was added. The reaction system was heated to 90°C, and after 15 minutes, a pre-prepared metallocene catalyst was added, and the reaction was started with stirring. After the reaction was carried out under nitrogen at atmospheric pressure for 2 hours, samples were taken and analyzed by gas chromatography with internal standard method. The conversion rate of the raw material was 99.1%, and the dimer selectivity was 23.4%. The reaction was stopped, and 10 mL of 5% hydrochloric acid ethanol solution was added to the system. The reaction was quenched by stirring for another 30 minutes. The solution was filtered through diatomaceous earth to obtain a crude product solution. The solvent, unreacted 1-decene, and low-boiling components were removed by vacuum distillation to obtain the oligomer product (36.4 g), with a yield of 70.1%. The hydrogenation of the oligomer was carried out in a 500 mL high-pressure reactor using a nickel catalyst. The reaction temperature was 130 °C, the reaction pressure was 4 MPa, and the reaction time was 4 h. After post-processing, the metallocene PAO product was obtained, and its kinematic viscosity (100 °C) was determined to be 4.4 mmHg according to the relevant standards. 2 / s, viscosity index 134, pour point -57 degrees Celsius.

[0160] The test methods for various viscosity-temperature properties of PAO in the application examples are as follows:

[0161] a. Determination and Calculation of Kinematic Viscosity of Petroleum Products: GB / T 265-88

[0162] b. Calculation method for viscosity index of petroleum products: GB / T 1995-1998

[0163] c. Determination of Pour Point of Petroleum Products: GB / T 3535-2006

[0164] Application Example 2

[0165] The reaction procedure and operation were the same as in Application Example 1, except that the metallocene catalyst used in the reaction was bis(pentamethylcyclopentadienyl)zirconium dichloride (1a). After the reaction, gas chromatography with internal standard analysis showed a feed conversion rate of 98.9%, a dimer selectivity of 29.6%, and an oligomer yield of 66.2%. The kinematic viscosity (100 degrees Celsius) of the metallocene PAO was determined to be 4.1 mm. 2 / s, viscosity index 135, pour point -54 degrees Celsius.

[0166] The above-described embodiments are merely preferred embodiments provided to fully illustrate the present invention, and the scope of protection of the present invention is not limited thereto. Equivalent substitutions or modifications made by those skilled in the art based on the present invention are all within the scope of protection of the present invention. The scope of protection of the present invention is defined by the claims.

Claims

1. A process for the preparation of a non-bridged symmetrical metallocene catalyst characterized in that, The non-bridged symmetrical metallocene catalyst is obtained by one-pot two-step reaction of a fourth sub-group metal chloride, a C1-C3 alkyl metal reagent and a cyclopentadiene derivative in a nitrogen or argon environment and in an organic solvent; The method comprises: (1) adding 2 equivalents of the C1-C3 alkyl metal reagent to a mixture of the fourth sub-group metal chloride and the organic solvent at a certain feeding temperature, and reacting at room temperature to obtain a mixture; (2) adding 2 equivalents of the cyclopentadiene derivative to the mixture obtained in step (1) at a certain feeding temperature, and reacting at a certain reaction temperature; The certain feeding temperature is -78-0 °C, and the certain reaction temperature is 25-140 °C; the fourth sub-group metal chloride has a general formula of MCl4, wherein M is titanium, zirconium or hafnium; The C1-C3 alkyl metal reagent is RLi, R2Zn or RMgX; wherein R is a C1-C3 normal alkyl group, and X is halogen chloride, bromine or iodine; The cyclopentadiene derivative is selected from the following compounds: ； wherein R 1 is a C2-C4 carbon chain alkyl, benzyl, trimethylsilyl group; n is an integer from 2 to 5; when R 3 is hydrogen, R 2 is a C1-C4 carbon chain alkyl, benzyl, trimethylsilyl group; when R 2 is hydrogen, R 3 is a C1-C4 carbon chain alkyl, benzyl, phenyl, 4-methylphenyl, 4-methoxyphenyl; or R 2 and R 3 are simultaneously methyl or ethyl; R 4 is hydrogen, methyl, phenyl.

2. The method of claim 1 for the preparation of a non-bridged symmetrical metallocene catalyst, characterized in that, The certain feeding temperature is -40--10 °C, and the certain reaction temperature is 60-110 °C.

3. The method of claim 1 for the preparation of a non-bridged symmetrical metallocene catalyst, characterized in that, The organic solvent is n-hexane, n-heptane, toluene, o-xylene, tetrahydrofuran, 2-methyltetrahydrofuran, diethyl ether or glycol dimethyl ether.

4. The method of claim 1 for the preparation of a non-bridged symmetrical metallocene catalyst, characterized in that, The reaction time of step (1) is 4-8 hours, and the reaction time of step (2) is 5-10 hours.

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