Metallocene compound and preparation method therefor and use thereof

Abstract

Provided are a metallocene compound and a preparation method therefor and a use thereof. The metallocene compound is a bridged Cs-symmetric large-conjugated-coordination metallocene compound, exhibiting high catalytic activity, and polypropylene produced by a catalytic reaction exhibits high tacticity.

Description

A metallocene compound, its preparation method and application

[0001] This application claims priority to Chinese Patent Application No. 202411530467.7, filed on October 30, 2024, entitled "A metallocene compound and its preparation method and application", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This invention relates to a metallocene compound, and more particularly to a metallocene compound, its preparation method, and its application, belonging to the field of olefin catalyst technology. Background Technology

[0003] Metallocene catalysts can be used to catalyze the polymerization of olefins such as ethylene and propylene to prepare polymers. Metallocene catalysts have several advantages, including: (1) Metallocene catalysts can precisely control the arrangement of monomers in polymers, thereby controlling the hardness, melting point and transparency of polymers, achieving high product selectivity; (2) The narrow molecular weight distribution of polymers is beneficial to improving the stability of polymer performance and facilitating the efficient preparation of high-quality polymers; (3) Metallocene catalysts have high catalytic activity, which means that metallocene catalysts can efficiently polymerize monomers to obtain polymers, reducing the total amount of metallocene catalysts used and helping to reduce production costs; (4) The structure of metallocene catalysts is well-defined, making it easier to better understand and optimize the performance of metallocene catalysts.

[0004] In the existing technology, metallocene catalysts face several constraints on their development, including: (1) the complex preparation process of metallocene catalysts increases their production cost, making them more expensive than Ziegler-Natta catalysts; (2) metallocene catalysts are sensitive to moisture and air, requiring stringent handling and storage conditions; and (3) metallocene catalysts are incompatible with all types of monomers or additives used in the polymerization process, resulting in limited compatibility. Researching the preparation methods of metallocene compounds and modifying them may provide insights into addressing these constraints. Furthermore, modifying metallocene compounds can alter the microstructure of polymers to improve their macroscopic properties. Therefore, researching the preparation and modification methods of metallocene compounds has been a continuous exploration in the polyolefin industry. For example, patent document CN101838363B discloses a method for manufacturing propylene copolymers, in which propylene is polymerized with at least one monomer selected from α-olefins and polyenes other than propylene in the presence of a catalyst for olefin polymerization. The catalyst contains (a-2) a crosslinked metallocene compound as shown in formula [1-1] below, and (b) at least one compound selected from (b-1) an organoaluminum oxide compound, (b-2) a compound that forms ion pairs, and (b-3) an organoaluminum compound.

[0005] In equation [1-1], R 1 R 2 R 3 and R 4 For hydrogen atoms; R 5 R 8 R 9 and R 12 Atoms or groups selected from hydrogen atoms, hydrocarbon groups, and silicon-containing groups; R 6 R 11 R is selected from the same atom or the same group, which is composed of hydrogen atoms, hydrocarbon groups, and silicon-containing groups; 7 R 10 R is selected from the same atom or the same group, which is composed of hydrogen atoms, hydrocarbon groups, and silicon-containing groups; 6 R 7 R 10 R 11 They are not both hydrogen atoms at the same time; R 5 ~R 12 Adjacent bases in the middle can combine with each other to form rings; R 13 and R 14 , where M is chloroaryl, etc.; , where T is Ti, etc.; , where Y is carbon, etc.; , where Q is halogen, etc.; and j is an integer from 1 to 4.

[0006] Patent document CN1280300C discloses a heterocyclic metallocene compound and its use in a catalyst system for the production of olefin polymers. The metallocene compound is: LGZMXp, where L is a divalent group, Z is a part of formula [1-2], and R3 and R... 4 Selected from hydrogen and hydrocarbon groups; A and B are selected from S, O, or CR5, and A or B is different from CR. 5 G is a part of equation [1-3], where R 6 R 7 R 8 and R 9 Selected from hydrogen and hydrocarbon groups,

[0007] Patent document CN101056901B discloses a solution polymerization method for obtaining isotactic, crystalline, or crystallizable 1-butene / propylene polymers. The method includes contacting 1-butene and propylene under polymerization conditions at a temperature range of 50°C to 90°C in the presence of a catalyst system. The catalyst system can be obtained by contacting the following substances: a) at least one metallocene compound; b) an aluminoxane or a compound capable of forming alkyl metallocene cations; and optionally c) an organoaluminum compound. The polymerization medium consists of a mixture of 1-butene and propylene, with the propylene content in the liquid phase ranging from 1% to 60% by weight.

[0008] In addition to the problems mentioned above, metallocene catalysts also have issues such as the need to improve catalytic activity and the regularity of the syndiotactic polypropylene catalytic product. There is still considerable room for improvement in the catalytic activity of metallocene catalysts, and the polypropylene prepared by propylene polymerization catalyzed by metallocene catalysts still has the problem of low regularity. Summary of the Invention

[0009] This invention provides a metallocene compound, its preparation method, and its application, which can improve the catalytic activity of metallocene compounds in the polymerization of propylene to prepare polypropylene and improve the regularity of polypropylene.

[0010] The present invention also provides a method for preparing a metallocene compound, which can be used to prepare the aforementioned metallocene compound with high catalytic activity, and the polypropylene prepared by the metallocene compound has high regularity.

[0011] The first aspect of this invention provides a metallocene compound, the structure of which is shown in Formula I:

[0012] In Formula I, Z1, Z2, Z3, and Z4 are each independently selected from N, O, S, or C; X1 and X2 are each independently selected from halogens or alkyl groups; E is selected from silicon chains or carbon chains; M is selected from transition metals in Group IVB of the periodic table; and R is selected from alkyl groups.

[0013] Optionally, the structure of the metallocene compound... Selected from:

[0014] Optionally, the halogen is selected from F, Cl, Br or I; and / or, the alkyl group is selected from alkyl groups having 1 to 6 carbon atoms; and / or, the E group is selected from isopropylidene, ethylidene, dimethylsilyl or dimethylsilyl; and / or, the M group is selected from zirconium or hafnium.

[0015] A second aspect of the present invention provides a method for preparing the metallocene compound described in the first aspect, comprising the following steps: 1) subjecting the compound shown in Formula II and the compound shown in Formula III to a first reaction to obtain the compound shown in Formula IV.

[0016] In Formula II, Y1, Y2, Y3, and Y4 are each independently selected from halogens; in Formula III, Y5 is selected from halogens; and in Formula IV, Y6 and Y7 are each independently selected from halogens.

[0017] 2) The compound shown in Formula IV and the compound shown in Formula V undergo a second reaction to obtain the compound shown in Formula VI.

[0018] In Formula VI, Z1, Z2, Z3, and Z4 are each independently selected from N, O, S, or C; in Formula V, Z5 and Z6 are each independently selected from N, O, S, or C; and in Formula V, Y8 is selected from halogens.

[0019] 3) The compound shown in formula VI is subjected to a hydrogenation-to-TMS removal reaction and an alkynyl cyclization rearrangement reaction sequentially to obtain the compound shown in formula VII.

[0020] 4) The compound shown in formula VII is subjected to a reduction reaction to obtain the compound shown in formula VIII.

[0021] 5) The compound shown in Formula VIII and the starting material containing cyclopentene compounds are subjected to a third reaction to obtain the compound shown in Formula XI;

[0022] Wherein, the raw material containing cyclopentene compounds includes the compound shown in Formula IX and / or the compound shown in Formula X; or, the raw material containing cyclopentene compounds includes the compound shown in Formula XII and the compound shown in Formula XIII;

[0023] In formula IX, R1, R2, and R3 are each independently selected from alkyl groups; in formula X, R4 and R5 are each independently selected from alkyl groups; in formula XII, at least one of R6, R7, R8, and R9 is a halogen, and the others are each independently selected from alkyl groups; in formula XIII, R... 10 Selected from alkyl groups;

[0024] In formula XI, R is selected from alkyl groups;

[0025] 6) The compound shown in Formula XI and the compound containing element M are subjected to a complexation reaction to obtain the metallocene compound shown in Formula I.

[0026] Optionally, in step 1), the compound represented by formula II includes 2,2',6,6'-tetrahalodiphenyl; and / or, in step 1), the compound represented by formula III includes methyl formate; and / or, in step 2), the compound represented by formula V includes 3-bromo-2-((trimethylsilyl)ethynyl)-1H-pyrrole, ((3-bromothiophen-2-yl)ethynyl)trimethylsilane, ((3-bromofuran-2-yl)ethynyl)trimethylsilane, 4-bromo-5-((trimethylsilyl)ethynyl)oxazole, 4-bromo-5-((trimethylsilyl) One or more of ethynylthiazole or 4-bromo-5-((trimethylsilyl)ethynyl)-1H-imidazolium; and / or, in step 5), the compound represented by formula IX includes 6,6-dimethylfulne; and / or, in step 5), the compound represented by formula X includes 5-ethylenecyclopentane-1,3-diene; and / or, in step 5), the compound represented by formula XII includes one or more of trimethylchlorosilane and dichlorodimethylsilane; and / or, in step 5), the compound represented by formula XIII includes one or more of cyclopentadienyl sodium and methylcyclopentadienyl sodium.

[0027] Optionally, in step 1), the temperature of the first reaction is -100 to -60°C, and the time of the first reaction is 20 to 60 min; and / or, in step 4), the temperature of the reduction reaction is 100 to 200°C, and the time of the reduction reaction is 10 to 30 h; and / or, in step 5), the temperature of the third reaction is -100 to -60°C, and the time of the third reaction is 6 to 20 h; and / or, in step 6), the temperature of the complexation reaction is -100 to -60°C, and the time of the complexation reaction is 1 to 4 h.

[0028] Optionally, in step 1), n-butyllithium is added to a mixed solution of the compound of formula II and anhydrous tetrahydrofuran, and then the compound of formula III is added to carry out a first reaction. After the first reaction is completed, the first reaction is quenched, and the mixture is extracted, dried, filtered, and concentrated to obtain the compound of formula IV; and / or, in step 2), the compound of formula V is cooled to -100 to -80°C and a first catalyst is added, then the temperature is raised to 50 to 80°C and zinc chloride is added, and finally the compound of formula IV and tetra(triphenylphosphine)platinum are added to carry out a second reaction. After the second reaction is completed, the second reaction is quenched, and the mixture is extracted, dried, filtered, and concentrated to obtain the compound of formula VI; wherein the first catalyst includes tert-butyllithium; And / or, in step 3), the alkynyl cyclization rearrangement reaction is carried out under the action of a fifth catalyst, the fifth catalyst including PtCl2; and / or, in step 4), the compound shown in formula VII is reduced with hydrazine under alkaline conditions to obtain the compound shown in formula VIII; and / or, in step 6), the compound containing element M includes a halide containing element M, and the complexation reaction process includes complexing the compound shown in formula XI with the halide containing element M to obtain the metallocene compound shown in formula I, or complexing the compound shown in formula XI with the halide containing element M and then reacting it with an alkylating agent to obtain the metallocene compound shown in formula I; and / or, in step 6), the complexation reaction is carried out under the action of n-butyllithium.

[0029] A third aspect of the present invention provides a catalyst comprising a metallocene compound as described above or a metallocene compound prepared by the preparation method described above.

[0030] Optionally, the catalyst further includes a co-catalyst; the co-catalyst includes an alkylaluminoxane compound or an organoboron compound; in the catalyst, the molar ratio of the metallocene compound to the co-catalyst is (400-4000):1; preferably, the alkylaluminoxane compound includes one or more of methylaluminoxane, ethylaluminoxane, butylaluminoxane, pentylaluminoxane, decylaluminoxane, and methylaluminoxane modified with triisobutylaluminum; preferably, the organoboron compound includes one or more of organoborane compounds and borates; wherein the organoborane compound includes a fluorinated organoborane compound, the fluorinated organoborane compound includes one or more of tris(pentafluorophenyl)borane and tris[3,5-bis(trifluoromethyl)phenyl]borane; the borate includes a fluorinated organoborate compound, the fluorinated organoborate compound includes one or more of tetra(2,3,5,6-tetrafluorophenyl)borate, tetra(pentafluorophenyl)borate, and N,N-dimethylaniline[3,5-bis(trifluoromethyl)phenyl]borate.

[0031] A fourth aspect of the present invention provides a catalytic reaction, said catalytic reaction being a polypropylene polymerization reaction using the catalyst described above.

[0032] This invention provides a metallocene compound, its preparation method, and its application. This metallocene compound can catalyze the synthesis of syndiotactic polypropylene with higher regularity from propylene, and has high catalytic activity. It is also beneficial for increasing the molecular weight of syndiotactic polypropylene. Detailed Implementation

[0033] 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.

[0034] This invention provides a metallocene compound, the structure of which is shown in Formula I:

[0035] In Formula I, Z1, Z2, Z3, and Z4 are each independently selected from N, O, S, or C; X1 and X2 are each independently selected from halogens or alkyl groups; E is selected from silicon chains or carbon chains; M is selected from transition metals in Group IVB of the periodic table; and R is selected from alkyl groups.

[0036] According to the inventors' research and analysis, the metallocene compound shown in Formula I has a bridged Cs-symmetric structure. The M transition metal is flanked by a cyclopentenyl ligand derivative with small steric hindrance and a cyclopentenyl ligand derivative with large steric hindrance. Based on the migration-insertion mechanism of polymer chain growth, during the polymerization of propylene to polypropylene catalyzed by the above metallocene compound, the growing chain of polypropylene migrates alternately between the two ligands, resulting in two adjacent monomer units in polypropylene having opposite stereoconfigurations, thus yielding syndiotactic polypropylene. Furthermore, due to the significant steric hindrance of the cyclopentenyl ligand derivative on the growing chain, the aforementioned significant hindrance... Under the influence of the metallocene compound, the first C-C bond in the growing polypropylene chain always points to a sterically hindered ligand, reducing the probability of erroneous insertion of 2,1- and 1,3- ligands. This results in higher selectivity and control over the polypropylene chain growth configuration, enhancing the accuracy of polypropylene spatial orientation and leading to higher regularity in the resulting syndiotactic polypropylene. Furthermore, the electron-withdrawing effect of the large π-bond in the conjugated terminal heterocycle of the metallocene compound in Formula I reduces the electron cloud density around the transition metal atom, improving the active coordination of the olefin molecule to the metal and thus enhancing the catalytic activity of the metallocene compound. Therefore, the metallocene compound of this invention can synthesize syndiotactic polypropylene with high catalytic activity, and the resulting syndiotactic polypropylene exhibits high regularity and molecular weight.

[0037] In Equation 1, Z1, Z2, Z3, and Z4 are each independently selected from N, O, S, or C. It is understood that N may include NH, and C may include CH.

[0038] In some embodiments, the structure of the above-mentioned metallocene compound

[0039] Selected from:

[0040] Introducing these helical olefin heterocyclic derivatives into metallocene compounds allows the sterically hindered ligands in the metallocene compound structure to exert a greater hindrance on the growing chain. This ensures that the first C-bond in the growing chain of polypropylene always points to the sterically hindered ligand, reducing the probability of erroneous insertion of 2,1- and 1,3- ligands. Consequently, the accuracy of the spatial orientation of polypropylene is enhanced, resulting in syndiotactic polypropylene with higher regularity. This also helps to improve the molecular weight and other properties of syndiotactic polypropylene.

[0041] For example, the halogens mentioned above can be selected from F, Cl, Br or I.

[0042] Furthermore, in order to avoid R affecting the sterically hindered cyclopentenyl ligand derivative in Formula I, the alkyl group can be selected from alkyl groups having 1 to 6 carbon atoms.

[0043] In Formula I, E acts as a connecting bridge. In some embodiments, E is selected from isopropylidene, ethylidene, dimethylsilyl or dimethylsilyl.

[0044] In some embodiments, M is selected from zirconium or hafnium.

[0045] This invention also provides a method for preparing the above-mentioned metallocene compound, comprising the following steps:

[0046] 1) The compound shown in Formula II and the compound shown in Formula III undergo a first reaction to obtain the compound shown in Formula IV.

[0047] In Formula II, Y1, Y2, Y3, and Y4 are each independently selected from halogens; in Formula III, Y5 is selected from halogens; and in Formula IV, Y6 and Y7 are each independently selected from halogens.

[0048] 2) The compound shown in Formula IV and the compound shown in Formula V undergo a second reaction to obtain the compound shown in Formula VI.

[0049] In Formula VI, Z1, Z2, Z3, and Z4 are each independently selected from N, O, S, or C; in Formula V, Z5 and Z6 are each independently selected from N, O, S, or C; and in Formula V, Y8 is selected from halogens.

[0050] 3) The compound shown in formula VI is subjected to a hydrogenation-to-TMS removal reaction and an alkynyl cyclization rearrangement reaction sequentially to obtain the compound shown in formula VII.

[0051] 4) The compound shown in formula VII is reduced to obtain the compound shown in formula VIII.

[0052] 5) The compound shown in Formula VIII and the starting material containing cyclopentene compounds are subjected to a third reaction to obtain the compound shown in Formula XI; wherein the starting material containing cyclopentene compounds includes the compound shown in Formula IX and / or the compound shown in Formula X; or, the starting material containing cyclopentene compounds includes the compound shown in Formula XII and the compound shown in Formula XIII.

[0053] In formula IX, R1, R2, and R3 are each independently selected from alkyl groups; in formula X, R4 and R5 are each independently selected from alkyl groups; in formula XII, at least one of R6, R7, R8, and R9 is a halogen, and the others are each independently selected from alkyl groups; in formula XIII, R... 10 Selected from alkyl groups;

[0054] In formula XI, R is selected from alkyl groups;

[0055] 6) The compound shown in Formula X and the compound containing element M are subjected to a complexation reaction to obtain the metallocene compound shown in Formula I.

[0056] The preparation method provided in this invention involves first obtaining a compound with a relatively simple structure, as shown in Formula IV. Then, based on the compound shown in Formula IV, a compound shown in Formula VI is obtained. Subsequently, compounds shown in Formula VII, Formula VIII, and Formula XI are obtained sequentially. Finally, based on the compound shown in Formula XI, a metallocene compound shown in Formula I is obtained. This stepwise reaction method for obtaining the metallocene compound shown in Formula I makes the preparation process more controllable, improves the preparation efficiency of metallocene compounds, ensures the clear structure of the metallocene compounds, and thus helps to ensure the performance of the metallocene compounds. In addition, in the above preparation method, the raw materials are inexpensive, readily available, and have high utilization rates, which helps to save production costs.

[0057] In some embodiments, in step 1), the compound represented by formula II includes 2,2',6,6'-tetrahalodiphenyl.

[0058] In some embodiments, in step 1), the compound represented by formula III includes methyl formate.

[0059] In some embodiments, in step 2), the compound represented by formula V includes one or more of 3-bromo-2-((trimethylsilyl)ethynyl)-1H-pyrrole, ((3-bromothiophen-2-yl)ethynyl)trimethylsilane, ((3-bromofuran-2-yl)ethynyl)trimethylsilane, 4-bromo-5-((trimethylsilyl)ethynyl)oxazole, 4-bromo-5-((trimethylsilyl)ethynyl)thiazole, or 4-bromo-5-((trimethylsilyl)ethynyl)-1H-imidazolium.

[0060] In some embodiments, in step 5), the compound represented by formula IX includes 6,6-dimethylfulne.

[0061] In some embodiments, in step 5), the compound represented by formula X includes 5-ethylenecyclopentane-1,3-diene.

[0062] In some embodiments, in step 5), the compound represented by formula XII includes one or more of trimethylchlorosilane and dichlorodimethylsilane.

[0063] In some embodiments, in step 5), the compound represented by formula XIII includes one or more of cyclopentadienyl sodium and methylcyclopentadienyl sodium.

[0064] In some embodiments, in step 1), n-butyllithium is added to a mixed solution of the compound shown in Formula II and anhydrous tetrahydrofuran, and then the compound shown in Formula III is added to carry out a first reaction. After the first reaction is completed, the first reaction is quenched, and the mixture is extracted, dried, filtered, and concentrated to obtain the compound shown in Formula IV.

[0065] Under the action of n-butyllithium, the compound shown in Formula II underwent a lithium halide exchange reaction to obtain a disubstituted benzene-type lithium reagent intermediate; the halogen of the compound shown in Formula III and the above-mentioned disubstituted benzene-type lithium reagent intermediate underwent a nucleophilic substitution reaction. Based on the reaction principle that the reaction between the sterically hindered ester group (α hydrogen is substituted) and the organolithium compound (disubstituted benzene-type lithium reagent intermediate) will remain at the ketone stage, the compound shown in Formula IV was obtained.

[0066] In addition, after quenching the first reaction, an organic layer containing the compound shown in Formula IV can be obtained by extraction with diethyl ether. The organic layer is then dried with magnesium sulfate, filtered and concentrated under reduced pressure to obtain a yellow solid, which is the compound shown in Formula IV. The above operation is beneficial to improving the yield of the compound shown in Formula IV.

[0067] Furthermore, in step 1), the temperature of the first reaction is -100 to -60°C, and the reaction time is 20 to 60 minutes, which helps to promote the smooth progress of the first reaction and increase the yield of the compound shown in Formula IV.

[0068] Understandably, stirring can be performed during the first reaction to make the reaction more complete.

[0069] In addition, in practice, the first reaction can be quenched by adding a saturated NH4Cl aqueous solution to the mixed solution after the first reaction.

[0070] In some embodiments, in step 2), the compound shown in formula V is cooled to -100 to -80°C and a first catalyst is added. Then, the temperature is raised to 50 to 80°C and zinc chloride is added. Finally, the compound shown in formula IV and tetra(triphenylphosphine)platinum are added and the temperature is raised to 50 to 80°C to carry out a second reaction. After the second reaction is completed, the second reaction is quenched and then extracted, dried, filtered, and concentrated to obtain the compound shown in formula VI. The first catalyst includes tert-butyllithium.

[0071] The compound shown in Formula V reacts with zinc chloride under the action of a first catalyst to prepare the organozinc reagent of the compound shown in Formula V; the organozinc reagent of the compound shown in Formula V undergoes a Negishi cross-coupling reaction with the compound shown in Formula IV, that is, carbon-carbon coupling, to obtain the compound shown in Formula VI.

[0072] In addition, after quenching the second reaction, the second reaction system can be concentrated under reduced pressure, and then extracted with dichloromethane to obtain an organic layer containing the compound shown in formula VI. After washing the organic layer with brine, the organic layer is dried with magnesium sulfate, and then filtered and concentrated under reduced pressure to obtain a yellow solid, which is the compound shown in formula VI. The above operation is beneficial to improving the yield of the compound shown in formula VI.

[0073] For example, the brine solution includes a sodium chloride solution and / or a potassium chloride solution, wherein the concentration of sodium chloride in the sodium chloride solution is 0.5 to 1.5 mol / L, for example, 0.5 mol / L, 1 mol / L, 1.5 mol / L or any combination thereof, and the concentration of potassium chloride in the potassium chloride solution is 0.5 to 1.5 mol / L, for example, 0.5 mol / L, 1 mol / L, 1.5 mol / L or any combination thereof.

[0074] Understandably, stirring can be performed during the second reaction to make the reaction more complete.

[0075] In addition, in practice, the second reaction can be quenched by adding a saturated NH4Cl aqueous solution to the mixed solution after the second reaction.

[0076] In some embodiments, in step 3), the mixture of the compound shown in Formula VI, potassium carbonate, dichloromethane, and methanol is vigorously stirred until the hydrogenation removal of TMS is completed. Then, the hydrogenation removal of TMS is quenched, and the mixture is extracted with dichloromethane to obtain an organic layer. The organic layer is dried using magnesium sulfate, and then filtered and concentrated under reduced pressure to obtain the TMS-removed yellow intermediate, i.e., the compound shown in Formula XIV.

[0077] In the above hydrogenation reaction for TMS removal, potassium carbonate provides alkaline conditions, dichloromethane is the organic solvent, and methanol is the proton donor used to remove TMS from the compound shown in formula VI.

[0078] Furthermore, in practice, the first reaction can be quenched by adding water to the mixed solution after the hydrogenation removal of TMS. Next, using toluene as an organic solvent, the compound shown in Formula XIV undergoes an alkynyl cyclization rearrangement reaction in the presence of a fifth catalyst, which includes PtCl2, to obtain the compound shown in Formula VII.

[0079] The TMS mentioned above refers to trimethylsilyl.

[0080] In addition, after the above alkynyl cyclization rearrangement reaction is completed, the reaction system can be concentrated under reduced pressure, and the product can be recrystallized with hexane / CH2Cl2 to obtain a red solid, namely the compound shown in formula VII.

[0081] In some embodiments, in step 4), the compound shown in formula VII is reduced with hydrazine under alkaline conditions to obtain the compound shown in formula VIII.

[0082] Specifically, the compound shown in Formula VII and hydrazine are added to KOH and diethylene glycol for a reduction reaction, which reduces the carbonyl group in the compound shown in Formula VII to a methylene group. The reduction reaction system is then neutralized with concentrated hydrochloric acid solution, filtered, and the colorless precipitate is collected and washed with water to obtain a colorless solid, which is the compound shown in Formula VIII.

[0083] Furthermore, in step 4), the temperature of the reduction reaction is 100–200 °C, and the time of the reduction reaction is 10–30 h, which is conducive to promoting the smooth progress of the reduction reaction and increasing the yield of the compound shown in formula VIII.

[0084] In step 5), a solution of lithium methyl ether is first added dropwise to the compound of formula VIII dissolved in THF to induce a dehydrogenation reaction in the compound of formula VIII, yielding a cyclopentadienyl lithium intermediate. Next, the reaction system containing the cyclopentadienyl lithium intermediate is cooled to -80°C to -76°C, for example, -80°C, -78°C, -76°C, or any combination thereof. Then, a starting material containing a cyclopentene compound is added dropwise. The reaction system is then heated to room temperature and stirred overnight to generate the compound of formula XI.

[0085] Furthermore, after heating the reaction system to room temperature and stirring overnight, the compound shown in Formula XI can be obtained through steps such as separating the organic layer, drying the organic layer, concentration, and precipitation. Magnesium sulfate can be used as a drying agent for the drying process, evaporation concentration can be used for the concentration process, and the precipitation process involves first dissolving the concentrated material in chloroform, then adding excess methanol to form a white powdery precipitate, which is the compound shown in Formula XI.

[0086] In some embodiments, the process of cooling the reaction system containing the cyclopentadienyl lithium intermediate to -80°C to -76°C includes: after the gas overflow in the reaction system containing the cyclopentadienyl lithium intermediate stops, stirring the reaction system (orange / deep orange / red solution) containing the cyclopentadienyl lithium intermediate for several hours (e.g., 1 to 5 hours) and then cooling it to -80°C to -76°C.

[0087] When the raw material containing cyclopentene compounds includes the compound shown in Formula IX and / or the compound shown in Formula X, E in the compound shown in Formula XI is a carbon chain; when the raw material containing cyclopentene compounds includes the compound shown in Formula XII and the compound shown in Formula XIII, E in the compound shown in Formula XI is a silicon chain.

[0088] Furthermore, in step 5), the temperature of the third reaction is -100 to -60°C, and the time of the third reaction is 6 to 20 hours, which is conducive to promoting the smooth progress of the reduction reaction and increasing the yield of the compound shown in formula XI.

[0089] In some embodiments, in step 6), the compound containing element M includes a halide containing element M, and the complexation reaction process includes complexing the compound shown in formula XI with the halide containing element M to obtain the metallocene compound shown in formula I. In this case, X1 and X2 in formula I are both halogens.

[0090] In other embodiments, the compound shown in Formula XI is complexed with a halide containing element M, and then reacted with an alkylating agent to obtain the metallocene compound shown in Formula I. Since the alkyl group in the alkylating agent replaces the halogen introduced by the halide, X1 and X2 in Formula I are both alkyl groups.

[0091] Furthermore, in step 6), the complexation reaction is carried out under the action of n-butyllithium.

[0092] In addition, in step 6), the temperature of the complexation reaction is -100 to -60°C and the time of the complexation reaction is 1 to 4 hours, which helps to promote the smooth progress of the complexation reaction and increase the yield of the metallocene compound shown in Formula I.

[0093] In one specific embodiment, step 6) specifically includes: dissolving the compound shown in formula XI in THF, then adding n-butyllithium dropwise, reacting for a period of time, evaporating the solvent in the reaction system, and washing and purifying with dry deoxypentane to obtain a solid red dilithium salt; dissolving the solid red dilithium salt in dichloromethane at a temperature of -80 to -76°C, for example -80°C, -78°C, -76°C, or any combination thereof, and adding an isothermal and equal amount of a mixed slurry of zirconium chloride and dichloromethane for a complexation reaction, stirring for a period of time (for example, 1 to 2 hours), and then slowly raising the temperature of the system to 23 to 27°C, for example 23°C, 25°C, 27°C, or elsewhere. The mixture is stirred for 10–14 hours (e.g., 10h, 12h, 14h, or any combination thereof) within the range of any two of the above. The resulting white LiCl solid precipitate is filtered to obtain a brown / yellow dichloromethane solution. This brown / yellow dichloromethane solution is cooled to -22 to -18°C (e.g., -22°C, -20°C, -18°C, or any combination thereof) and allowed to stand for 10–14 hours (e.g., 10h, 12h, 14h, or any combination thereof). The supernatant is then aspirated through a tube and evaporated and concentrated to obtain a yellow powder, which is the metallocene compound represented by Formula I. In this case, X1 and X2 in Formula I are both chlorine. During the above process, the compound represented by Formula XI undergoes a dehydrogenation reaction under the action of n-butyllithium to form a cyclopentadienyl-like anionic intermediate. This cyclopentadienyl-like anionic intermediate undergoes a metallocene reaction with zirconium chloride to form the metallocene compound represented by Formula I.

[0094] This invention also provides a catalyst comprising the aforementioned metallocene compound or a metallocene compound prepared using the aforementioned method. This catalyst has effects corresponding to those of the aforementioned metallocene compounds, which will not be elaborated further here.

[0095] The catalyst may also include a co-catalyst; the co-catalyst includes alkylaluminoxane compounds or organoboron compounds; in the catalyst, the molar ratio of the metallocene compound to the co-catalyst is (400 to 4000):1, for example 400:1, 800:1, 1200:1, 2000:1, 2500:1, 3000:1, 3500:1, 4000:1 or any combination thereof.

[0096] Furthermore, the alkylaluminoxane compounds include one or more of methylaluminoxane, ethylaluminoxane, butylaluminoxane, pentylaluminoxane, decylaluminoxane, and methylaluminoxane modified with triisobutylaluminum.

[0097] Organoboron compounds include one or more of organoborane compounds and borates; wherein, organoborane compounds include fluorinated organoborane compounds, which include one or more of tris(pentafluorophenyl)borane and tris[3,5-bis(trifluoromethyl)phenyl]borane; borates include fluorinated organoborate compounds, which include one or more of tetra(2,3,5,6-tetrafluorophenyl)borate, tetra(pentafluorophenyl)borate, and N,N-dimethylaniline[3,5-bis(trifluoromethyl)phenyl]borate.

[0098] This invention also provides a catalytic reaction, which is a polypropylene polymerization reaction using the above-described catalyst.

[0099] The process of polypropylene polymerization using the catalyst described above includes: polymerizing propylene under the action of the catalyst to obtain polypropylene.

[0100] As mentioned above, propylene can be efficiently polymerized under the action of the aforementioned metallocene compounds to obtain syndiotactic polypropylene, which has high regularity and molecular weight.

[0101] Syndiotactic polypropylene has advantages such as faster crystallization rate, lower melting point, potential biocompatibility and higher chemical resistance. These advantages make it widely used in the field of specialty materials. For example, the faster crystallization rate and potential biocompatibility make it suitable for medical devices with specific functions and rapid processing requirements; the potential heat resistance and chemical resistance make it suitable for specific electronic components.

[0102] In some embodiments, the above-mentioned catalytic reaction, i.e., the polypropylene polymerization reaction, includes the following steps: passing propylene gas into a mixture containing an organic solvent, a metallocene compound and a co-catalyst, stirring the reaction for a period of time, and then terminating the reaction with 10% hydrochloric acid ethanol to obtain polypropylene.

[0103] The aforementioned organic solvents may include toluene.

[0104] Generally, the propylene gas is continuously introduced at a constant pressure, for example, 0.5 MPa. The propylene gas is then stopped after the polymerization reaction is completed. At the same time, the polymerization reaction can be terminated with 10% hydrochloric acid ethanol.

[0105] The aforementioned alkylaluminoxane compound can be a commercially available solution, or it can be obtained by repeatedly dissolving and distilling the commercially available solution to remove free alkylaluminum and perform BHT modification and silica modification. Typically, in the above polypropylene preparation method, the amount of alkylaluminoxane compound used can be determined according to a certain range of the molar ratio of aluminum provided by the alkylaluminoxane compound to the transition metal element in the metallocene compound. For example, when the transition metal is Zr, the above molar ratio is n[Al] / n[Zr] = 900, which helps to improve the preparation efficiency of polypropylene.

[0106] The embodiments of the present invention do not impose any particular limitation on the method of polypropylene polymerization reaction, and it can be any method in the prior art, such as gas phase, slurry, solution polymerization and other methods.

[0107] In some embodiments, the temperature of the above-mentioned catalytic reaction (polymerization reaction) is 70-80°C, which is beneficial to improving the catalytic activity of the metallocene compound.

[0108] The present invention will now be described in more detail through specific embodiments.

[0109] Examples 1 to 13

[0110] Example 1

[0111] 1) Butyllithium (2.68M hexane solution, 3.2 mL, 8.5 mmol) was added to a mixed solution of 2,2',6,6'-tetrabromodiphenyl (2.0 g, 4.3 mmol) and anhydrous THF (260 mL). After stirring at -80 °C for 2 h, methyl chloroformate (0.96 mL, 12.8 mmol) was added, and the mixture was stirred for 30 min to initiate the first reaction. After the first reaction was completed, saturated NH4Cl aqueous solution (3 mL) was added, and the mixture was stirred for 30 min to quench the first reaction. Water (20 mL) was then added, and the mixture was extracted with diethyl ether to obtain an organic layer. The organic layer was dried with anhydrous sodium sulfate, filtered, and concentrated under reduced pressure to obtain... The compound was obtained as a yellow solid. ¹H-NMR analysis of this compound yielded 1H NMR (400 MHz, CDCl₃) δ = 7.76–7.70 (m, 4H), 7.26–7.21 (m, 2H), confirming that the yellow solid compound was indeed the compound shown in Formula IV. Simultaneously, the theoretical yield of the compound shown in Formula IV was calculated based on the amount of raw materials used, and the actual yield was obtained by weighing. The yield of the compound shown in Formula IV was calculated to be 78% using the ratio of the actual yield to the theoretical yield. The specific structure of the compound shown in Formula IV is shown in Formula IV-1.

[0112] 2) A mixed solution of 3-bromo-2-((trimethylsilyl)ethynyl)-1H-pyrrole (6.05 g, 25.0 mmol) and THF (100 mL) was cooled to -80 °C, and then n-butyllithium (1.60 M pentane solution, 30.7 mL, 52.1 mmol) was added. After stirring for 40 min, the solution was heated to 0 °C and transferred to a mixture of zinc chloride (3.64 g, 26.4 mmol) and THF (100 mL). After stirring for 30 min, the compound shown in Formula IV-1 (3.34 g, 9.88 mmol) and THF were added. A mixed solution of (70 mL) and tetra(triphenylphosphine)platinum (2.28 g, 1.90 mmol) was added, and the mixture was heated to room temperature and refluxed for 22 h to carry out the second reaction. After the second reaction was completed, a saturated NH4Cl aqueous solution was added to quench the second reaction. The quenched second reaction system was then concentrated under reduced pressure. The residue after concentration was successively extracted with dichloromethane, washed with sodium chloride solution (sodium chloride concentration of 0.1 mol / L), dried with MgSO4, filtered, and concentrated under reduced pressure to obtain a yellow solid compound. The yellow solid compound was subjected to 1H-NMR, and the result was 1H NMR (500MHz, Chloroform-d) values ​​were 7.91 (t, J = 7.8Hz, 2H), 7.79 (dd, J = 7.9, 1.3Hz, 2H), 7.73 (dd, J = 7.7, 1.3Hz, 2H), 7.17 (s, 2H), 6.31 (d, J = 2.9Hz, 2H), and 0.25 (s, 9H). These results confirmed that the yellow solid compound was indeed the compound represented by formula VI. Furthermore, the theoretical yield of the compound represented by formula VI was calculated based on the amount of raw materials used, and the actual yield was obtained by weighing. The ratio of the actual yield of the compound represented by formula VI to the theoretical yield of the compound represented by formula IV yielded a yield of 35% for the compound represented by formula VI. The specific structure of the compound represented by formula VI is shown in formula VI-1.

[0113] 3) A mixture of the compound shown in Formula VI (4.5 g, 8.6 mmol), K₂CO₃ (2.6 g, 19 mmol), CH₂Cl₂ (20 mL), and MeOH (200 mL) was vigorously stirred until the hydrogenation removal of TMS was completed. The hydrogenation removal of TMS was then quenched with water (10 mL), and the organic layer was extracted with dichloromethane. This organic layer was washed with sodium chloride solution (0.1 mol / L), dried with magnesium sulfate, filtered, and concentrated under reduced pressure to obtain a yellow intermediate with removed TMS. The yellow intermediate (2.72 g, 7.15 mmol) and PtCl₂ (190 mg, 0.715 mmol) were mixed in toluene (200 mL) and refluxed for 18 h. After the reaction was complete, the reaction mixture was concentrated under reduced pressure and recrystallized from hexane / CH₂Cl₂ to obtain a red solid compound. The red solid compound was subjected to 1H-NMR, and the result was [missing information - likely a 1H NMR value]. NMR (500MHz, Chloroform-d) values ​​were δ 9.74 (s, 2H), δ 8.04 (d, J = 8.0Hz, 2H), 8.02–7.97 (m, 2H), 7.97–7.91 (m, 2H), 7.44–7.37 (m, 4H), and 7.26 (s, 2H). These results confirmed that the red solid compound was indeed the compound represented by formula VII. Furthermore, the theoretical yield of the compound represented by formula VII was calculated based on the amount of raw materials used, and the actual yield was obtained by weighing. The ratio of the actual yield to the theoretical yield of the compound represented by formula VII yielded a yield of 81%. The specific structure of the compound represented by formula VII is shown in formula VII-1.

[0114] 4) The compound shown in Formula VII-1 (47 g, 0.13 mol), hydrazine monohydrate (0.10 L, 3.2 mmol), and KOH (22 g, 0.40 mol) were mixed in diethylene glycol (6 L) and heated at 170 °C for 24 h to carry out the reduction reaction. After cooling to room temperature, the reduction reaction mixture was poured into a concentrated HCl solution at 0 °C. The resulting colorless precipitate was collected by filtration, washed with water, and a colorless solid was obtained. The colorless solid was subjected to 1H-NMR, and the result was 1H NMR. NMR (500MHz, Chloroform-d) values ​​were δ 10.12 (d, J = 6.1Hz, 2H), 7.94 (d, J = 8.2Hz, 2H), 7.87 (d, J = 8.1Hz, 2H), 7.75 (d, J = 8.6Hz, 2H), 7.39 (d, J = 8.5Hz, 2H), 7.29–7.22 (m, 4H), and 5.69 (d, J = 1.4Hz, 2H). These results confirmed that the colorless solid was indeed the compound represented by formula VIII. Furthermore, the actual yield of the compound represented by formula VIII was obtained by weighing, and the yield was calculated to be 89% by using the ratio of the actual yield to the theoretical yield.

[0115] 5) In a round-bottom flask equipped with a side arm and a dropping funnel, a mixed solution of methyllithium (0.25 mol) and diethyl ether (1.4 M) was added dropwise to the compound of formula VIII (86.1 g, 0.25 mol) dissolved in THF (250 mL) under stirring. After the gas escape stopped, the remaining orange solution was stirred for 6 hours and cooled to -78 °C. Then, THF (100 mL) containing 6,6-dimethylfulne (0.25 mol, 26.5 g) was added dropwise. The reaction system was then heated to room temperature and stirred overnight. Water (200 mL) was added and stirred for 10 min. After separating the organic layer, the organic layer was dried with magnesium sulfate. Then, the diethyl ether was evaporated to obtain a yellow solid residue. The yellow solid residue was dissolved in chloroform (500 mL) and excess methanol was added to obtain a white powdery precipitate. The white powdery precipitate was subjected to 1H-NMR, and the result was 1H NMR (500MHz, DMSO-d6) δ11.41(d,J=6.5Hz,2H),7.94(d,J=8.2Hz,2H),7.88(d,J=7.3Hz,2H),7.66(d,J=7.3Hz,2H),7.39(d, J=8.5Hz,2H),7.33(dd,J=6.7,3.6Hz,2H),7.26(d,J=3.9Hz,2H),6.14–6.06(m,2H),5.76(dt,J=2.8,1.3Hz,1H),5.66(td,J= The results, using the parameters 7.0, 2.8Hz, 2H), 1.79 (dddd, J = 7.3, 6.2, 3.2, 1.6Hz, 1H), and 1.14 (t, J = 1.6Hz, 6H), confirmed that the white powdery precipitate was indeed the compound represented by formula XI. Furthermore, the theoretical yield of the compound represented by formula XI was calculated based on the amount of raw materials used, and the actual yield was obtained by weighing. The yield of the compound represented by formula XI was calculated to be 62% using the ratio of the actual yield to the theoretical yield. The specific structure of the compound represented by formula XI is shown in formula XI-1.

[0116] 6) The compound shown in Formula XI (0.025 mol) was dissolved in THF (200 mL), and then n-butyllithium (0.05 mol) was added dropwise. After reacting for a period of time, the solvent in the reaction system was evaporated, and the mixture was washed and purified with dry deoxypentane to obtain a solid red dilithium salt. The solid red dilithium salt was dissolved in dichloromethane at -78 °C, and an isothermal mixture of equal amounts of zirconium chloride (5.83 g, 0.025 mol) and dichloromethane (125 mL) was added to carry out a complexation reaction. After stirring for 2 h, the system was slowly heated to 25 °C and stirred for 12 h. The resulting white solid LiCl precipitate was filtered to obtain a brown dichloromethane solution. The brown dichloromethane solution was cooled to -20 °C and allowed to stand for 12 hours. The supernatant was aspirated with a tube and then evaporated and concentrated to obtain a yellow powder. The yellow powder was subjected to 1H-NMR, and the result was 1H NMR(500MHz,Chloroform-d)δ7.76(dt,J=8.5,0.6Hz,2H),7.66–7.60(m,2H),7.56(dt,J=8.1,0.9Hz,2H ),6.33(q,J=1.7Hz,2H),6.19(d,J=8.4Hz,2H),5.93(q,J=1.8Hz,2H),4.43(t,J=3.0Hz,2H),3.62(q,J=3 The results showed that the yellow powder was indeed the metallocene compound represented by Formula I. Simultaneously, the theoretical yield of the metallocene compound represented by Formula I was calculated based on the amount of raw materials used, and the actual yield was obtained by weighing. The yield of the metallocene compound represented by Formula I was calculated to be 59% using the ratio of the actual yield to the theoretical yield.

[0117] 7) After replacing a 250 mL three-necked flask with propylene three times, place it in a 70 °C constant temperature water bath and add 50 mL of toluene, 2.0 μmol of the metallocene compound shown in Formula I, and 1 g of a 10% (w / w) methylaluminoxane toluene solution (n[Al] / n[Zr] = 900). Propylene gas is continuously introduced under normal pressure, and the reaction is stirred for 30 min to carry out the polymerization reaction. Then, the propylene gas cylinder is closed and the polymerization reaction is terminated with 10% hydrochloric acid ethanol. The product is dried to obtain polypropylene.

[0118] Example 2

[0119] This embodiment is basically the same as Embodiment 1, except that:

[0120] In step 2), 3-bromo-2-((trimethylsilyl)ethynyl)-1H-pyrrole (6.05 g, 25.0 mmol) was replaced with ((3-bromothiophen-2-yl)ethynyl)trimethylsilane (6.48 g, 25.0 mmol);

[0121] In step 6), zirconium chloride (5.83 g, 0.025 mol) is replaced with hafnium chloride (8.01 g, 0.025 mmol);

[0122] All other conditions remain unchanged.

[0123] The 1H-NMR results of the metallocene compound represented by Formula I in Example 2 are as follows: 1H NMR (500MHz, Chloroform-d) 1H NMR (500MHz, DMSO-d6) δ 8.02 (d, J = 5.4Hz, 2H), 7.95 (d, J = 6.9Hz, 2H), 7.88 (d, J = 7.9Hz, 2H), 7.80 (d, J = 7.0Hz, 2H), 7.76–7.68 (m, 4H), 5.69 (s, 1H), 3.63 (q, J = 3.5Hz, 2H), 3.26–3.16 (m, 2H), 1.22 (s, 6H). The specific structure of the metallocene compound represented by Formula I in Example 2 is shown in Formula (Example 2):

[0124] (Example 2)

[0125] Example 3

[0126] This embodiment is basically the same as Embodiment 1, except that:

[0127] In step 2), 3-bromo-2-((trimethylsilyl)ethynyl)-1H-pyrrole (6.05 g, 25.0 mmol) was replaced with ((3-bromofuran-2-yl)ethynyl)trimethylsilane (6.08 g, 25.0 mmol);

[0128] In step 5), 6,6-dimethylfulne (0.25 mol, 26.5 g) is replaced with 5-ethylenecyclopentane-1,3-diene (0.25 mol, 23.0 g);

[0129] All other conditions remain unchanged.

[0130] The 1H-NMR results of the metallocene compound represented by Formula I in Example 3 are as follows: 1H NMR (500MHz, DMSO-d6) δ 7.88 (dd, J = 13.0, 7.7Hz, 4H), 7.76–7.71 (m, 2H), 7.52 (d, J = 1.6Hz, 2H), 7.42 (d, J = 7.3Hz, 2H), 7.04 (d, J = 1.5Hz, 2H), 5.55 (s, 1H), 3.67 (q, J = 3.5Hz, 2H), 3.25–3.16 (m, 2H), 1.22 (s, 3H). The specific structure of the metallocene compound represented by Formula I in Example 3 is shown in Formula (Example 3):

[0131] (Example 3)

[0132] Example 4

[0133] This embodiment is basically the same as Embodiment 1, except that:

[0134] In step 2), 3-bromo-2-((trimethylsilyl)ethynyl)-1H-pyrrole (6.05 g, 25.0 mmol) was replaced with 4-bromo-5-((trimethylsilyl)ethynyl)oxazole (6.10 g, 25.0 mmol);

[0135] All other conditions remain unchanged.

[0136] The 1H-NMR results of the metallocene compound of Formula I in Example 4 are as follows: 1H NMR (500MHz, DMSO-d6) δ 7.90 (d, J = 8.0Hz, 2H), 7.80 (d, J = 8.0Hz, 2H), 7.75 (d, J = 8.0Hz, 2H), 7.53–7.47 (m, 4H), 3.66 (q, J = 3.5Hz, 2H), 3.26–3.16 (m, 2H), 1.27 (s, 6H). The specific structure of the metallocene compound of Formula I in Example 4 is shown in Formula (Example 4):

[0137] (Example 4)

[0138] Example 5

[0139] This embodiment is basically the same as Embodiment 1, except that:

[0140] In step 2), 3-bromo-2-((trimethylsilyl)ethynyl)-1H-pyrrole (6.05 g, 25.0 mmol) was replaced with 4-bromo-5-((trimethylsilyl)ethynyl)thiazole (6.51 g, 25.0 mmol);

[0141] In step 5), 6,6-dimethylfulne (0.25 mol, 26.5 g) is replaced with dichlorodimethylsilane (0.25 mol, 32.3 g) and sodium cyclopentadienyl (0.25 mol, 22.02 g);

[0142] All other conditions remain unchanged.

[0143] The 1H-NMR results of the metallocene compound of Formula I in Example 5 are as follows: 1H NMR (500MHz, DMSO-d6) δ 9.31 (s, 2fH), 8.12 (d, J = 7.6Hz, 2H), 7.84 (dd, J = 18.3, 8.0Hz, 4H), 7.75 (d, J = 8.0Hz, 2H), 3.58 (q, J = 3.5Hz, 2H), 3.22–3.11 (m, 2H), 0.88 (s, 6H). The specific structure of the metallocene compound of Formula I in Example 5 is shown in Formula (Example 5):

[0144] (Example 5)

[0145] Example 6

[0146] This embodiment is basically the same as Embodiment 1, except that:

[0147] In step 2), 3-bromo-2-((trimethylsilyl)ethynyl)-1H-imidazolium (6.08 g, 25.0 mmol) was replaced with 4-bromo-5-((trimethylsilyl)ethynyl)-1H-pyrrole (6.05 g, 25.0 mmol).

[0148] In step 5), 6,6-dimethylfulne (0.25 mol, 26.5 g) is replaced with dichlorodimethylsilane (0.25 mol, 32.3 g) and sodium methylcyclopentadienyl (0.25 mol, 25.5 g);

[0149] All other conditions remain unchanged.

[0150] The 1H-NMR results of the metallocene compound represented by Formula I in Example 6 are as follows: 1H NMR (500MHz, DMSO-d6) δ 10.16 (d, J = 5.7Hz, 2H), 8.34 (d, J = 6.0Hz, 2H), 7.90 (d, J = 9.3Hz, 2H), 7.85 (d, J = 8.0Hz, 2H), 7.76 (d, J = 8.0Hz, 2H), 7.68 (d, J = 9.2Hz, 2H), 3.55 (q, J = 3.5Hz, 2H), 3.22–3.10 (m, 1H), 1.45 (dt, J = 5.7, 1.2Hz, 3H). The specific structure of the metallocene compound represented by Formula I in Example 6 is shown in Formula (Example 6):

[0151] (Example 6)

[0152] Example 7

[0153] This embodiment is basically the same as Embodiment 1, except that:

[0154] 2,2',6,6'-tetrabromodiphenyl was replaced with 4.3 mmol of 2,2',6,6'-tetrachlorodiphenyl (2.0 g, 4.3 mmol), while other conditions remained unchanged. The specific structure of the metallocene compound of Formula I in Example 7 is the same as that of the metallocene compound of Formula I in Example 1.

[0155] Example 8

[0156] This embodiment is basically the same as Embodiment 1, except that:

[0157] The 2,2',6,6'-tetrabromodiphenyl ether (2.0 g, 4.3 mmol) was replaced with 4.3 mmol of 2,2',6,6'-tetrafluorodiphenyl ether, while all other conditions remained unchanged. The specific structure of the metallocene compound of Formula I in Example 8 is the same as that of the metallocene compound of Formula I in Example 1.

[0158] Example 9

[0159] This embodiment is basically the same as Embodiment 1, except that:

[0160] Replace 3-bromo-2-((trimethylsilyl)ethynyl)-1H-pyrrole (6.05 g, 25.0 mmol) with 25.0 mmol of ((3-bromothiophen-2-yl)ethynyl)trimethylsilane, while keeping other conditions unchanged.

[0161] The 1H-NMR results of the metallocene compound of Formula I in Example 9 are as follows: 1H NMR (500MHz, DMSO-d6) δ 7.88 (dd, J = 13.0, 7.7Hz, 4H), 7.76–7.71 (m, 2H), 7.52 (d, J = 1.6Hz, 2H), 7.42 (d, J = 7.3Hz, 2H), 7.04 (d, J = 1.5Hz, 2H), 3.67 (q, J = 3.5Hz, 2H), 3.25–3.16 (m, 2H), 1.22 (s, 6H).

[0162] The specific structure of the metallocene compound represented by Formula I in Example 9 is shown in Formula (Example 9):

[0163] (Example 9)

[0164] Example 10

[0165] This embodiment is basically the same as Embodiment 1, except that:

[0166] Replace 3-bromo-2-((trimethylsilyl)ethynyl)-1H-pyrrole (6.05 g, 25.0 mmol) with 25.0 mmol of 4-bromo-5-((trimethylsilyl)ethynyl)thiazole, while keeping all other conditions unchanged.

[0167] The 1H-NMR results for the metallocene compound of Formula I in Example 10 are as follows: 1H NMR (500 MHz, DMSO-d6) δ 9.31 (s, 2fH), 8.12 (d, J = 7.6 Hz, 2H), 7.84 (dd, J = 18.3, 8.0 Hz, 4H), 7.75 (d, J = 8.0 Hz, 2H), 3.58 (q, J = 3.5 Hz, 2H), 3.22–3.11 (m, 2H), 1.22 (s, 6H).

[0168] The specific structure of the metallocene compound represented by Formula I in Example 10 is shown in Formula (Example 10):

[0169] (Example 10)

[0170] Example 11

[0171] This embodiment is basically the same as Embodiment 1, except that:

[0172] Replace 3-bromo-2-((trimethylsilyl)ethynyl)-1H-imidazol (6.05 g, 25.0 mmol) with 25.0 mmol of 4-bromo-5-((trimethylsilyl)ethynyl)-1H-imidazol, while keeping all other conditions unchanged.

[0173] The 1H-NMR results of the metallocene compound of Formula I in Example 11 are as follows: 1H NMR (500MHz, DMSO-d6) δ 10.16 (d, J = 5.7Hz, 2H), 8.34 (d, J = 6.0Hz, 2H), 7.90 (d, J = 9.3Hz, 2H), 7.85 (d, J = 8.0Hz, 2H), 7.76 (d, J = 8.0Hz, 2H), 7.68 (d, J = 9.2Hz, 2H), 3.55 (q, J = 3.5Hz, 2H), 3.22–3.10 (m, 2H);

[0174] The specific structure of the metallocene compound represented by Formula I in Example 11 is shown in Formula (Example 11):

[0175] (Example 11)

[0176] Example 12

[0177] This embodiment is basically the same as Embodiment 1, except that:

[0178] Replace 6,6-dimethylfulne (0.25 mol, 26.5 g) with 0.25 mol of 5-ethylenecyclopentane-1,3-diene, while keeping other conditions unchanged.

[0179] The 1H-NMR results of the metallocene compound of Formula I in Example 12 are as follows: 1H NMR (500MHz, Chloroform-d) δ 7.75 (dt, J = 8.5, 0.6Hz, 2H), 7.66–7.60 (m, 2H), 7.56 (dt, J = 8.1, 0.9Hz, 2H), 6.33 (q, J = 1.7Hz, 2H), 6.19 (d, J = 8.4Hz, 2H), 5.94 (q, J = 1.8Hz, 2H), 4.43 (t, J = 3.0Hz, 2H), 3.62 (q, J = 3.5Hz, 2H), 3.26–3.13 (m, 2H), 1.28 (s, 3H), 1.11 (s, 1H);

[0180] The specific structure of the metallocene compound represented by Formula I in Example 12 is shown in Formula (Example 12):

[0181] (Example 12)

[0182] Example 13

[0183] This embodiment is basically the same as Embodiment 1, except that:

[0184] Replace 6,6-dimethylfulne (0.25 mol, 26.5 g) with 0.25 mol trimethylchlorosilane and sodium cyclopentadienyl, while keeping other conditions unchanged.

[0185] The 1H-NMR results of the metallocene compound of Formula I in Example 13 are as follows: 1H NMR (500MHz, Chloroform-d) δ 7.76 (dt, J = 8.5, 0.6Hz, 2H), 7.64–7.61 (m, 2H), 7.54 (dt, J = 8.1, 0.9Hz, 2H), 6.34 (q, J = 1.7Hz, 2H), 6.11 (d, J = 8.4Hz, 2H), 5.90 (q, J = 1.8Hz, 2H), 4.43 (t, J = 3.0Hz, 2H), 3.62 (q, J = 3.5Hz, 2H), 3.26–3.13 (m, 2H), 0.23 (s, 6H).

[0186] The specific structure of the metallocene compound represented by Formula I in Example 13 is shown in Formula (Example 13): (Example 13)

[0187] Comparative Examples 1 to 2

[0188] Comparative Example 1

[0189] This comparative example provides a method for preparing polypropylene, which specifically includes the following steps:

[0190] A 250 mL three-necked flask was purged with propylene three times and placed in a 70 °C constant temperature water bath. 50 mL of toluene, 2.0 μmol of compound [Me2C(Flu)(Cp)]ZrCl2 (commercially purchased reagent from Witco, USA), and 1 g of 10% methylaluminoxane toluene solution (n[Al] / n[Zr] = 900) were added sequentially. Propylene gas was continuously introduced under normal pressure, and the reaction was stirred for 30 min to carry out the polymerization reaction. Then, the propylene gas cylinder was closed, and the polymerization reaction was terminated with 10% hydrochloric acid ethanol. The product was dried to obtain polypropylene.

[0191] Comparative Example 2

[0192] This comparative example is basically the same as Comparative Example 1, except that:

[0193] Replace compound [Me2C(Flu)(Cp)]ZrCl2 (commercially available, reagent from Witco, USA) with compound [Me2C(2-Ph-Ind)(Cp)]ZrCl2 (commercially available, reagent from Witco, USA); keep all other conditions unchanged.

[0194] Test case

[0195] 1. The following parameters of the above embodiments and comparative examples were tested:

[0196] 1) Catalytic activity of catalyst in polypropylene preparation process: The catalytic activity of catalyst is expressed as the mass of polypropylene produced by catalyst per unit time and per molar amount of catalyst. Specific results are shown in Table 1.

[0197] 2) Molecular weight and molecular weight distribution of polypropylene: The molecular weight and molecular weight distribution were tested using an Ailance GPC V2000 GPC analyzer. The specific results are shown in Table 1.

[0198] 3) Regularity of polypropylene: The regularity of polypropylene was calculated based on the carbon NMR spectrum of polypropylene. The specific results are shown in Table 1.

[0199] 2. Test Results

[0200] Table 1. Catalyst and Polypropylene Performance

[0201] Data analysis: The catalysts prepared in Examples 1-13 have high catalytic activity, and the polypropylene prepared by catalysis has high molecular weight and high regularity.

[0202] 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 metallocene compound, characterized in that, The structure of the metallocene compound is shown in Formula I: In Formula I, Z1, Z2, Z3, and Z4 are each independently selected from N, O, S, or C; X1 and X2 are each independently selected from halogens or alkyl groups; E is selected from silicon chains or carbon chains; M is selected from transition metals in Group IVB of the periodic table; and R is selected from alkyl groups.

2. The metallocene compound according to claim 1, characterized in that, The structure of the metallocene compound Selected from:

3. The metallocene compound according to claim 1 or 2, characterized in that, The halogen is selected from F, Cl, Br or I; And / or, the alkyl group is selected from alkyl groups having 1 to 6 carbon atoms; And / or, the E is selected from isopropylidene, ethylidene, dimethylsilyl or dimethylsilyl; And / or, M is selected from zirconium or hafnium.

4. A method for preparing the metallocene compound according to any one of claims 1-3, characterized in that, Includes the following steps: 1) The compound shown in Formula II and the compound shown in Formula III undergo a first reaction to obtain the compound shown in Formula IV. In Formula II, Y1, Y2, Y3, and Y4 are each independently selected from halogens; in Formula III, Y5 is selected from halogens; and in Formula IV, Y6 and Y7 are each independently selected from halogens. 2) The compound shown in Formula IV and the compound shown in Formula V undergo a second reaction to obtain the compound shown in Formula VI. In Formula VI, Z1, Z2, Z3, and Z4 are each independently selected from N, O, S, or C; in Formula V, Z5 and Z6 are each independently selected from N, O, S, or C; and in Formula V, Y8 is selected from halogens. 3) The compound shown in formula VI is subjected to a hydrogenation-to-TMS removal reaction and an alkynyl cyclization rearrangement reaction sequentially to obtain the compound shown in formula VII. 4) The compound shown in formula VII is subjected to a reduction reaction to obtain the compound shown in formula VIII. 5) The compound shown in Formula VIII and the starting material containing cyclopentene compounds are subjected to a third reaction to obtain the compound shown in Formula XI; Wherein, the raw material containing cyclopentene compounds includes the compound shown in Formula IX and / or the compound shown in Formula X; or, the raw material containing cyclopentene compounds includes the compound shown in Formula XII and the compound shown in Formula XIII; In formula IX, R1, R2, and R3 are each independently selected from alkyl groups; in formula X, R4 and R5 are each independently selected from alkyl groups; in formula XII, at least one of R6, R7, R8, and R9 is a halogen, and the others are each independently selected from alkyl groups; in formula XIII, R... 10 Selected from alkyl groups; In formula XI, R is selected from alkyl groups; 6) The compound shown in Formula XI and the compound containing element M are subjected to a complexation reaction to obtain the metallocene compound shown in Formula I.

5. The preparation method according to claim 4, characterized in that, In step 1), the compound represented by formula II includes 2,2',6,6'-tetrahalodiphenyl; And / or, in step 1), the compound represented by formula III includes methyl chloride formate; And / or, in step 2), the compound represented by formula V includes one or more of 3-bromo-2-((trimethylsilyl)ethynyl)-1H-pyrrole, ((3-bromothiophen-2-yl)ethynyl)trimethylsilane, ((3-bromofuran-2-yl)ethynyl)trimethylsilane, 4-bromo-5-((trimethylsilyl)ethynyl)oxazole, 4-bromo-5-((trimethylsilyl)ethynyl)thiazole, or 4-bromo-5-((trimethylsilyl)ethynyl)-1H-imidazolium; And / or, in step 5), the compound represented by formula IX includes 6,6-dimethylfulne; And / or, in step 5), the compound represented by formula X includes 5-ethylenecyclopentane-1,3-diene; And / or, in step 5), the compound represented by formula XII includes one or more of trimethylchlorosilane and dichlorodimethylsilane; And / or, in step 5), the compound represented by formula XIII includes one or more of cyclopentadienyl sodium and methylcyclopentadienyl sodium.

6. The preparation method according to claim 4, characterized in that, In step 1), the temperature of the first reaction is -100 to -60°C, and the reaction time is 20 to 60 minutes. And / or, in step 4), the temperature of the reduction reaction is 100-200°C, and the time of the reduction reaction is 10-30 h; And / or, in step 5), the temperature of the third reaction is -100 to -60°C, and the time of the third reaction is 6 to 20 hours; And / or, in step 6), the temperature of the complexation reaction is -100 to -60°C, and the time of the complexation reaction is 1 to 4 hours.

7. The preparation method according to claim 4, characterized in that, In step 1), n-butyllithium is added to a mixed solution of the compound shown in Formula II and anhydrous tetrahydrofuran, and then the compound shown in Formula III is added to carry out a first reaction. After the first reaction is completed, the first reaction is quenched, and the mixture is extracted, dried, filtered, and concentrated to obtain the compound shown in Formula IV. And / or, in step 2), the compound shown in formula V is cooled to -100 to -80°C and a first catalyst is added, then the temperature is raised to 50 to 80°C and zinc chloride is added, and finally the compound shown in formula IV and tetra(triphenylphosphine)platinum are added to carry out the second reaction. After the second reaction is completed, the second reaction is quenched, and the mixture is extracted, dried, filtered, and concentrated to obtain the compound shown in formula VI; wherein, the first catalyst includes tert-butyllithium; And / or, in step 3), the alkynyl cyclization rearrangement reaction is carried out in the presence of a fifth catalyst, which includes PtCl2; And / or, in step 4), the compound shown in formula VII is reduced with hydrazine under alkaline conditions to obtain the compound shown in formula VIII; And / or, in step 6), the compound containing element M includes a halide containing element M, and the complexation reaction process includes complexing the compound shown in formula XI with the halide containing element M to obtain the metallocene compound shown in formula I, or complexing the compound shown in formula XI with the halide containing element M and then reacting it with an alkylating agent to obtain the metallocene compound shown in formula I. And / or, in step 6), the complexation reaction is carried out under the action of n-butyllithium.

8. A catalyst, characterized in that, The catalyst comprises a metallocene compound as described in any one of claims 1-3 or a metallocene compound prepared by any one of claims 4-7.

9. The catalyst according to claim 8, characterized in that, The catalyst further includes a co-catalyst; the co-catalyst includes an alkylaluminoxane compound or an organoboron compound; in the catalyst, the molar ratio of the metallocene compound to the co-catalyst is (400-4000):1; Preferably, the alkylaluminoxane compound includes one or more of methylaluminoxane, ethylaluminoxane, butylaluminoxane, pentylaluminoxane, decylaluminoxane, and methylaluminoxane modified with triisobutylaluminum; Preferably, the organoboron compound includes one or more of organoborane compounds and borates; wherein the organoborane compound includes a fluorinated organoborane compound, the fluorinated organoborane compound including one or more of tris(pentafluorophenyl)borane and tris[3,5-bis(trifluoromethyl)phenyl]borane; the borate includes a fluorinated organoborate compound, the fluorinated organoborate compound including one or more of tetrakis(2,3,5,6-tetrafluorophenyl)borate, tetrakis(pentafluorophenyl)borate, and N,N-dimethylaniline[3,5-bis(trifluoromethyl)phenyl]borate.

10. A catalytic reaction, characterized in that, The catalytic reaction is a polypropylene polymerization reaction carried out using the catalyst described in claim 8 or 9.

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