Silicon-bridged metallocene catalysts and uses thereof

Abstract

The present invention relates to a silicon-bridged metallocene catalyst and its use, which has a cyclopentadiene ligand, a substituted fluorenyl ligand, and a silicon bridge connecting the two ligands. It also discloses a method for producing olefin polymers using a catalyst system containing such a metallocene compound, which catalyst system comprises at least one of the metallocene catalysts and at least one activator. The catalyst system provided by the present invention has high activity in catalyzing propylene polymerization, high polymer molecular weight, and flexible control of syndiotacticity.

Description

[Technical Field]

[0001] The present invention is in the field of catalyst manufacturing and relates to silicon-bridged metallocene catalysts and their uses. [Background technology]

[0002] Syndiotactic polypropylene has characteristics such as high transparency, excellent impact resistance, and excellent room temperature toughness, and is applied in the fields of medical supplies, packaging materials, and sanitary products. Currently, many petrochemical companies have successfully developed various catalyst systems and processes for the industrial production of syndiotactic polypropylene (US4892851, US5155080, US5225500, US5428121, US6713426, EP0896022). Ewen et al. (Journal of the American Chemical Society 1988, 110 (18), 6255-6256) were the first to synthesize a dimethyl-substituted carbon-bridged metallocene fluorene-type catalyst and apply it to the production of syndiotactic polypropylene, but the molecular weight of polypropylene obtained with this type of catalyst is usually relatively low (M w =3×10 4 ~1.3×10 5 g mol -1 ).

[0003] To improve the molecular weight of syndiotactic polypropylene, diphenyl-substituted carbon-bridged metallocene fluorene catalysts were applied to the propylene polymerization reaction. Compared with dimethyl-substituted carbon-bridged catalysts, the molecular weight of polypropylene obtained using diphenyl-substituted carbon-bridged metallocene fluorene catalysts was improved (M w =5.6×10 5 g mol -1 ), the catalytic activity was obviously reduced (6.82 × 10 4 vs 1.94×10 5 g PP(g Cat.) -1 h -1) In the literature (Journal of Organometallic Chemistry 1993, 459 (1), 117-123), it was reported that the molecular weight of polypropylene obtained by Hf-coordinated metallocene fluorene type catalyst is higher than that obtained by the same type of Zr-coordinated catalyst (M w =7.77×10 5 ), but the activity was also significantly reduced (5.4 × 10 4 g·(g Cat.) -1 h -1 However, Hf-coordinated metallocene compounds usually have a strong tendency for β-R migration, which increases the amount of error fragments inserted in the resulting syndiotactic polypropylene, resulting in a decrease in the regularity of the polymer chain.

[0004] Silicon-bridged bisindene metallocene catalysts have been successfully applied to the production of polypropylene, especially isotactic polypropylene. Compared to carbon-bridged catalysts, silicon-bridged catalysts have better stereoselectivity and regioselectivity. More importantly, compared to the low application temperatures (0°C to 30°C) of most carbon-bridged catalysts, silicon-bridged catalysts have better thermal stability, maintaining excellent activity, stereoregularity, regioregularity, and molecular weight control at industrial production temperatures, with application temperatures reaching 60°C to 120°C. It has been reported in the literature (Journal of Organometallic Chemistry 1996, 509 (1), 63-71; Journal of Molecular Catalysis A: Chemical 1998, 128 (1-3), 245-256; Organometallics, 2021, 40, 4055-4065) that silicon-bridged catalysts can be used to produce higher molecular weight syndiotactic polypropylene, but they still have problems such as low activity and poor syndiotacticity control (Macromolecular Symposia 1995, 89, 181-196; Chemical Reviews 2000, 100 (4), 1253-1345). US6559089 discloses a silicon-bridged metallocene fluorene catalyst modified with multiple substituents on the cyclopentadiene ring, but the catalyst can only be used to produce isotactic polypropylene, and cannot produce syndiotactic polypropylene.

[0005] In summary, there remains a need for novel silicon-bridged metallocene compounds to achieve high activity production of high molecular weight, highly regular syndiotactic polypropylene at high industrial temperatures. Summary of the Invention

[0006] One object of the present invention is to provide a silicon-bridged metallocene catalyst having a structure represented by the following general formula (I): [ka] where M is a Group 4 transition metal element, L is a monovalent anionic ligand; X is C1~C 10 an unsubstituted or substituted alkyl group, a phenyl group, or 1 to 3 C1 to C 10 is an aryl group containing an unsubstituted or substituted alkyl group of the formula R 1 and R 8 are independently hydrogen, a trifluoromethyl group, a phenyl group, a halogen, a C5-C 10 unsubstituted or substituted cycloalkyl groups of the formula C1-C 10 unsubstituted or substituted alkyl groups, C1-C 10 unsubstituted or substituted alkoxy groups, two C1-C 10 an amino group containing an unsubstituted or substituted alkyl group of 3 C1-C 10 a silicon group containing an unsubstituted or substituted alkyl group, 1 to 3 C1 to C 10 and unsubstituted or substituted heteroaryl groups containing unsubstituted or substituted alkyl groups of the formula: R 2 , R 3 , R 6 and R 7 are independently hydrogen, trifluoromethyl group, phenyl group, naphthyl group, anthryl group, phenanthryl group, halogen, C5 to C 10 unsubstituted or substituted cycloalkyl groups of the formula C1-C 10 unsubstituted or substituted alkyl groups, C1-C 10 unsubstituted or substituted alkoxy groups, two C1-C 10 an amino group containing an unsubstituted or substituted alkyl group of 3 C1-C 10 a silicon group containing an unsubstituted or substituted alkyl group, 1 to 3 C1 to C 10 aryl groups containing an unsubstituted or substituted alkyl group of the formula: R 4 and R 5 are independently hydrogen, trifluoromethyl group, halogen, C1-C 10unsubstituted or substituted alkyl groups, C1-C 10 unsubstituted or substituted alkoxy groups, two C1-C 10 an amino group containing an unsubstituted or substituted alkyl group of the formula 10 The silicon group containing the unsubstituted or substituted alkyl group is selected from the group consisting of:

[0007] Furthermore, M is zirconium or hafnium.

[0008] Furthermore, L is halogen or C1 to C 10 Preferably, L is a halogen or a C1 to C6 unsubstituted or substituted alkyl.

[0009] Furthermore, X is a C1-C6 unsubstituted or substituted alkyl group, a phenyl group, or an aryl group containing 1 to 3 C1-C6 unsubstituted or substituted alkyl groups. More preferably, X is a methyl group or a phenyl group.

[0010] Furthermore, R 1 and R 8 are independently selected from hydrogen, trifluoromethyl, and C1 to C6 unsubstituted or substituted alkyl groups. 1 and R 8 are independently selected from hydrogen, a trifluoromethyl group, and a C1 to C6 unsubstituted or substituted alkyl group.

[0011] Furthermore, R 2 , R 3 , R 6 and R 7 are independently hydrogen, a phenyl group, a naphthyl group, a C1-C 10 unsubstituted or substituted alkyl groups, 3 C1-C 10 a silicon group containing an unsubstituted or substituted alkyl group, 1 to 3 C1 to C 10 and unsubstituted or substituted aryl groups containing unsubstituted or substituted alkyl groups of the formula: 2 , R3 , R 6 and R 7 are independently selected from hydrogen, a phenyl group, a C1-C6 unsubstituted or substituted alkyl group, a silicon group containing three C1-C6 unsubstituted or substituted alkyl groups, and an aryl group containing one to three C1-C6 unsubstituted or substituted alkyl groups.

[0012] Furthermore, R 4 and R 5 are independently hydrogen and C1 to C 10 More preferably, R 4 and R 5 are independently selected from hydrogen and C1 to C6 unsubstituted or substituted alkyl groups.

[0013] Further, preferred examples of the compound of formula (I) are as follows: [ka] , [ka] , [ka] , [ka] , [ka] , [ka] , [ka] , [ka] ,

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[0014] Another object of the present invention is to provide the use of silicon-bridged metallocene catalysts in the preparation of catalyst systems for the polymerization of olefins.

[0015] A third object of the present invention is to provide a catalyst system for olefin polymerization comprising an activator, an inert support, and a silicon-bridged metallocene catalyst having the structure represented by formula (I) above.

[0016] Furthermore, the activator is one or more selected from aluminoxanes, alkyl aluminums, and borates.

[0017] Furthermore, the alkylaluminum activator applicable to the present invention is one or more selected from trimethylaluminum, triethylaluminum, triisopropylaluminum, tri-n-propylaluminum, triisobutylaluminum, tri-n-butylaluminum, triisopentylaluminum, tri-n-pentylaluminum, triisohexylaluminum, tri-n-hexylaluminum, triisoheptylaluminum, tri-n-heptylaluminum, triisooctylaluminum, tri-n-octylaluminum, triisononylaluminum, tri-n-nonylaluminum, triisodecylaluminum, and tri-n-decylaluminum.

[0018] Furthermore, the borate activator applicable to the present invention is one or more selected from N,N-dimethylanilinium tetrakis(pentafluorophenyl)borate, N,N-diethylanilinium tetrakis(pentafluorophenyl)borate, N,N-dibutylanilinium tetrakis(pentafluorophenyl)borate, N,N-trimethylammonium tetrakis(pentafluorophenyl)borate, N,N-diethylammonium tetrakis(pentafluorophenyl)borate, and N,N-tributylammonium tetrakis(pentafluorophenyl)borate.

[0019] Furthermore, the aluminoxane activator applied in the present invention is one or more selected from methylaluminoxane, modified methylaluminoxane, triisobutyldialuminoxane, polyisobutylaluminoxane, tetraethyldialuminoxane, pentaisobutyltrialuminoxane, 1,3-dichloro-1,3-diethyldialuminoxane, and 1,3-dichloro-1,3-dimethyldialuminoxane.

[0020] Furthermore, the inert carrier is one or more selected from the group consisting of silicon-containing inorganic porous carriers, aluminum-containing inorganic porous carriers, magnesium-containing inorganic porous carriers, and polymeric organic porous carriers. Preferably, the specific surface area of ​​the carrier is 20 m 2 / g or more.

[0021] Furthermore, the inert carrier applied in the present invention is one or more selected from silica, alumina, montmorillonite, magnesium chloride, molecular sieves, cyclodextrin, polyethylene, polystyrene, polyvinyl alcohol, and mesoporous silica gel fibers, and preferably one or more selected from silica, alumina, montmorillonite, magnesium chloride, and molecular sieves.

[0022] It is yet another object of the present invention to provide a method for producing a propylene polymer, the method comprising the steps of: Step 1) adding the catalyst system described above to a reactor; step 2) after adding the catalyst system, introducing propylene monomer into the reactor and contacting it with the catalyst system; and 3) maintaining the polymerization conditions to obtain a propylene polymer.

[0023] The propylene polymerization reaction of the present invention is carried out in a slurry or gas phase, and the resulting propylene polymer has a weight average molecular weight of 50,000 to 500,000 g / mol and a pentad syndiotacticity of 30% to 90%. DETAILED DESCRIPTION OF THE INVENTION

[0024] The present invention will be described in detail below with reference to specific examples, which are implemented based on the technical solutions of the present invention and provide detailed embodiments and specific operation procedures, but the scope of protection of the present invention is not limited to the following examples.

[0025] In each of the following examples, unless otherwise specified, all raw materials or processing techniques are conventional commercially available raw materials or conventional processing techniques in the art.

[0026] Example 1 Production of 1-methylfluorene [ka] A 100 mL three-neck flask was charged with 433 mg of Pd(PPh3)4 (0.38 mmol) and 3.98 g of Na2CO3 (37.5 mmol). The mixture was purged with nitrogen three times, and then 1.51 g of 2-bromophenylboronic acid (7.50 mmol) and 1.66 g of 2-methylbenzyl bromide (9.00 mmol) were added. 40 mL of ethylene glycol dimethyl ether, 15 mL of water, and 3 mL of ethanol were added. The mixture was heated to 90 °C and reacted for 12 h. The mixture was cooled to room temperature and extracted twice with 25 mL of dichloroethane. The organic phases were combined, washed twice with 10 mL of water, and dried over anhydrous MgSO4. The solvent was removed by filtration to obtain 1-bromo-2-(2-methylbenzyl)benzene.

[0027] A 50 mL reaction flask was charged with 1.3 g of 1-bromo-2-(2-methylbenzyl)benzene (5 mmol), 22.5 mg of Pd(OAc) (0.1 mmol), 84.6 mg of 1,3-di(2,6-diisopropylphenyl)imidazole chloride (0.2 mmol), and 0.69 g of KCO (5 mmol). The mixture was purged with nitrogen three times, 15 mL of N-methylpyrrolidone was added, and the mixture was heated to 130 °C for 12 h. The mixture was cooled to room temperature, extracted twice with 10 mL of n-hexane, and washed twice with 10 mL of water. The organic phase was collected, dried over anhydrous MgSO, and filtered. The solvent was removed to give 2.7 g of 2-methylfluorene.

[0028] 1 H NMR (500 MHz, Chloroform-d) δ 7.79 (d, J=7.5 Hz, 1H), 7.65 (d, J=7.5 Hz, 1H), 7.57 (d, J=7.4 Hz, 1H), 7.38 (t, J=7.4 Hz, 1H), 7.34-7.28 (m, 2H), 7.14 (d, J=7.4 Hz, 1H), 3.80 (s, 2H), 2.44 (s, 3H).

[0029] Example 2 Preparation of dimethyl(cyclopentadienyl)(1-methyl-9-fluorenyl)silylzirconium dichloride (catalyst 1) [ka] 2-Methylfluorene (1 g, 5.05 mmol) was added to a 100 mL Schlenk flask 1, and the flask was purged with nitrogen gas three times. 12 mL of toluene and 3.5 mL of tetrahydrofuran were added. n-BuLi (2.1 mL, 5.3 mmol) was slowly added at -40 °C, and the reaction was carried out at 25 °C for 3.5 h. Furthermore, the atmosphere in a 100 mL Schlenk flask 2 was purged with nitrogen gas three times, and 27 mL of toluene and dimethyldichlorosilane (3.9 g, 30.3 mmol) were added. The solution in flask 1 was added at -25 °C, and the reaction was carried out at 25 °C for 18 h. The reaction solvent was completely aspirated, and 5 mL of toluene was added and completely aspirated. 10 mL of toluene and 2.5 mL of tetrahydrofuran were added. Furthermore, a 25 mL Schlenk flask 3 was purged with nitrogen gas three times, and 13.5 mL of tetrahydrofuran, cyclopentadiene (0.38 g, 5.05 mmol), and 2.1 mL of n-BuLi (5.3 mmol) were added at −75° C., followed by reaction for 2 hours at 25° C. The solution in reaction flask 3 was then added to flask 2 at −45° C. and stirred at 25° C. for 3 hours.

[0030] The reaction solvent was completely aspirated, and 20 mL of toluene and 5 mL of ether were added. At −40°C, n-BuLi (4.1 mL, 10.4 mmol) was added, followed by a reaction at 25°C for 20 h. At −75°C, ZrCl4 (1.23 g, 5.15 mmol) was added, and the mixture was first stirred in an ice bath at −20°C for 3 h, and then reacted at 25°C for 15 h. The reaction solvent was completely aspirated, and 50 mL of toluene was added. The mixture was heated to 75°C, filtered through Celite while still hot, and washed with 20 mL of toluene. The filtrate was crystallized at −40°C and filtered to obtain 0.3 g of an orange solid.

[0031] 1H NMR (500 MHz, Chloroform-d) δ 8.15 (d, J=6.2 Hz, 1H), 8.02 (d, J=8.3 Hz, 1H), 7.79 (d, J=8.7 Hz, 1H), 7.61 (t, J=7.2 Hz, 1H), 7.52-7.47 (m, 1H), 7.34-7.29 (m, 1H), 7.15 (d, J=9.1 Hz, 1H), 6.72-6.68 (m, 1H), 6.51-6.47 (m, 1H), 5.82 (q, J=2.7 Hz, 1H), 5.69 (q, J=2.5 Hz, 1H), 2.59 (s, 3H), 1.21 (d, J = 7.0 Hz, 6H).

[0032] Example 3 Production of 2-methylfluorene [ka] 4.9 g of 2-bromofluorene (20 mmol) was weighed and placed in a 100 mL three-neck flask. 0.22 g of 1,3-bis(diphenylphosphino)propanenickel(II) chloride (0.4 mmol) was added. The mixture was purged with nitrogen gas three times and 20 mL of ether was added. 7.51 mL of methylmagnesium bromide (24 mmol) was added dropwise at 20-30 °C, followed by reaction at 25 °C. The reaction was monitored by gas chromatography. After completion of the reaction, the reaction solution was added to 100 mL of water and extracted twice with 15 mL of toluene solution. The solvent was removed to obtain 3.6 g of 2-methylfluorene with a GC purity of 98.1%.

[0033] 1 H NMR (500 MHz, Chloroform-d) δ 7.78 (d, J = 7.6 Hz, 1H), 7.71 (d, J = 7.7 Hz, 1H), 7.56 (d, J = 7.4 Hz, 1H), 7.42 - 7.37 (m, 2H), 7.31 (t, J = 7.4 Hz, 1H), 7.22 (d, J = 6.9 Hz, 1H), 3.89 (s, 2H), 2.47 (s, 3H).

[0034] Example 4 Preparation of dimethyl(cyclopentadienyl)(2-methyl-9-fluorenyl)silylzirconium dichloride (catalyst 2) [ka] 2-Methylfluorene (3 g, 16.6 mmol) was added to a 100 mL Schlenk flask 1, and the flask was purged with nitrogen gas three times. 35 mL of toluene and 5 mL of tetrahydrofuran were added, and n-BuLi (7 mL, 17.5 mmol) was added at -40 °C. The reaction was carried out at 25 °C for 3 h. Furthermore, the atmosphere in a 250 mL Schlenk flask 2 was purged with nitrogen gas three times, and 40 mL of toluene and dimethyldichlorosilane (12.9 g, 100 mmol) were added. The solution in flask 1 was added at -25 °C, and the reaction was carried out at 25 °C for 18 h. The reaction solvent was completely aspirated, and 40 mL of toluene was added. The mixture was then completely aspirated again, and 40 mL of toluene was added. Furthermore, a 100 mL Schlenk flask 3 was purged with nitrogen gas three times, and 35 mL of toluene and 5 mL of tetrahydrofuran were added, followed by cyclopentadiene (1.10 g, 16.6 mmol), and n-BuLi (7 mL, 17.5 mmol) was slowly added at −75° C., followed by reaction for 2 hours at 25° C. Thereafter, the solution in reaction flask 3 was added to flask 2 at −45° C., followed by stirring at 25° C. for 6 hours.

[0035] The reaction solvent was completely aspirated, and 30 mL of toluene and 7.5 mL of ether were added. At −45°C, n-BuLi (13.6 mL, 34 mmol) was added, and the reaction was continued at 25°C for 20 h. At −75°C, ZrCl4 (3.43 g, 14.6 mmol) was added, and the reaction was continued at 25°C for 20 h. The reaction solvent was completely aspirated, and 250 mL of toluene was added. The mixture was filtered through Celite, and the Celite was washed with 50 mL of toluene. The filtrate was collected, and the solvent was removed. At −40°C, n-hexane was added, and the mixture was stirred for 30 min and filtered to obtain approximately 0.2 g of a red solid.

[0036] 1H NMR (500 MHz, Chloroform-d) δ 8.07 (d, J = 8.3 Hz, 1H), 8.01 (d, J=8.4 Hz, 1H), 7.85 (t, J=6.5 Hz, 1H), 7.78 (d, J=7.7 Hz, 1H), 7.63 (t, J=7.6 Hz, 1H), 7.53 (t, J=7.2 Hz, 1H), 7.48 (d, J=8.9 Hz, 2H), 6.61 (s, 2H), 5.75 (s, 2H), 2.42 (s, 3H), 1.15 (s, 6H).

[0037] Example 5 Preparation of dimethyl(cyclopentadienyl)(3-methyl-9-fluorenyl)silylzirconium dichloride (catalyst 3) [ka] 3-Methylfluorene (1 g, 5.05 mmol) was added to a 100 mL Schlenk flask 1, and the flask was purged with nitrogen gas three times. 12 mL of toluene and 3.5 mL of tetrahydrofuran were added. n-BuLi (2.1 mL, 5.3 mmol) was slowly added at -40 °C, and the reaction was carried out at 25 °C for 3.5 h. Furthermore, the atmosphere in a 100 mL Schlenk flask 2 was purged with nitrogen gas three times, and 27 mL of toluene and dimethyldichlorosilane (3.9 g, 30.3 mmol) were added. The solution in flask 1 was added at -25 °C, and the reaction was carried out at 25 °C for 18 h. The reaction solvent was completely aspirated, and 5 mL of toluene was added and completely aspirated. 10 mL of toluene and 2.5 mL of tetrahydrofuran were added. Furthermore, a 25 mL Schlenk flask 3 was purged with nitrogen gas three times, and 13.5 mL of tetrahydrofuran, cyclopentadiene (0.38 g, 5.05 mmol), and 2.1 mL of n-BuLi (5.3 mmol) were added at −75° C., followed by reaction for 2 hours at 25° C. The solution in reaction flask 3 was then added to flask 2 at −45° C. and stirred at 25° C. for 3 hours.

[0038] The reaction solvent was completely evacuated at 35 °C, and 20 mL of toluene and 5 mL of ether were added. At −45 °C, n-BuLi (4.1 mL, 10.4 mmol) was added, and the mixture was reacted at 25 °C for 20 h. ZrCl (1.23 g, 5.15 mmol) was added at −75 °C, and the mixture was first stirred in an ice bath at −20 °C for 3 h, then transferred to 25 °C and reacted for 15 h. The reaction solvent was completely evacuated, and 50 mL of toluene was added. The mixture was heated to 75 °C, filtered through Celite while still hot, and the Celite was washed with 20 mL of toluene. The filtrate was collected, crystallized at −40 °C, and filtered to obtain 0.6 g of an orange solid.

[0039] 1 H NMR (500 MHz, Chloroform-d) δ 8.07 (d, J = 8.3 Hz, 1H), 8.01 (d, J=8.4 Hz, 1H), 7.85 (t, J=6.5 Hz, 1H), 7.78 (d, J=7.7 Hz, 1H), 7.63 (t, J=7.6 Hz, 1H), 7.53 (t, J=7.2 Hz, 1H), 7.48 (d, J=8.9 Hz, 2H), 6.61 (s, 2H), 5.75 (s, 2H), 2.42 (s, 3H), 1.15 (s, 6H).

[0040] Example 6 Production of 2,7-dimethylfluorene [ka] 6.5 g of 2,7-dibromofluorene (20 mmol) was weighed and placed in a 100 mL three-neck flask. 0.22 g of 1,3-bis(diphenylphosphino)propanenickel(II) chloride (0.4 mmol) was added. The mixture was purged with nitrogen gas three times and 20 mL of ether was added. 7.51 mL of methylmagnesium bromide (24 mmol) was added dropwise at 20-30 °C, followed by reaction at 25 °C. The reaction was monitored by gas chromatography. After completion of the reaction, the reaction solution was added to 100 mL of water and extracted twice with 15 mL of toluene solution. The solvent was removed to obtain 3.88 g of 2,7-dimethylfluorene. GC purity was 100%.

[0041] 1 H NMR (500 MHz, Chloroform-d) δ 7.65 (d, J = 7.6 Hz, 1H), 7.35 (s, 1H), 7.19 (d, J = 7.8 Hz, 1H), 3.84 (s, 1H), 2.45 (s, 3H).

[0042] Example 7 Preparation of dimethyl(cyclopentadienyl)(2,7-dimethyl-9-fluorenyl)silylzirconium dichloride (catalyst 4) [ka] 2,7-dimethylfluorene (2.8 g, 14.4 mmol) was added to a 100 mL Schlenk flask 1, and the flask was purged with nitrogen gas three times. 35 mL of toluene and 5 mL of tetrahydrofuran were added, and n-BuLi (6.05 mL, 15.1 mmol) was added at -40 °C. The reaction was carried out at 25 °C for 3 h. Furthermore, the atmosphere in a 250 mL Schlenk flask 2 was purged with nitrogen gas three times, and 40 mL of toluene and dimethyldichlorosilane (11.20 g, 86.5 mmol) were added. The solution in flask 1 was added at -25 °C, and the reaction was carried out at 25 °C for 18 h. The reaction solvent was completely aspirated, and 40 mL of toluene was added. The mixture was then completely aspirated again, and 40 mL of toluene was added. Furthermore, a 100 mL Schlenk flask 3 was purged with nitrogen gas three times, and 35 mL of toluene and 5 mL of tetrahydrofuran were added, followed by cyclopentadiene (1.002 g, 14.4 mmol), and then n-BuLi (6.05 mL, 15.1 mmol) at −75° C., followed by reaction for 2 hours at 25° C. Thereafter, the solution in reaction flask 3 was added to flask 2 at −45° C., followed by stirring at 25° C. for 3 hours.

[0043] The reaction solvent was completely aspirated, and 30 mL of toluene and 7.5 mL of ether were added. At −45°C, n-BuLi (11.8 mL, 29.5 mmol) was added, and the reaction was continued at 25°C for 20 h. At −75°C, ZrCl4 (3.43 g, 14.6 mmol) was added, and the reaction was continued at 25°C for 3 h. The reaction solvent was completely aspirated, and 100 mL of toluene was added. The mixture was heated to 45°C, filtered through Celite while still hot, and the Celite was washed twice with 20 mL of toluene. The filtrate was collected, crystallized at −20°C, and filtered to obtain 0.35 g of an orange solid.

[0044] 1 H NMR (500 MHz, Chloroform-d) δ 7.95 (d, J=8.5 Hz, 2H), 7.45 (d, J=8.6 Hz, 2H), 7.18 (d, J=7.1 Hz, 2H), 6.62 (t, J=2.4 Hz, 2H), 5.73 (t, J=2.4 Hz, 2H), 2.41 (s, 6H), 1.13 (s, 6H).

[0045] Example 8 Production of 3,6-dimethylfluorene [ka] 6.5 g of 3,6-dibromofluorene (20 mmol) was weighed and placed in a 100 mL three-neck flask. 0.22 g of 1,3-bis(diphenylphosphino)propanenickel(II) chloride (0.4 mmol) was added. The mixture was purged with nitrogen three times and 20 mL of ether was added. At 20-30 °C, 7.51 mL of methylmagnesium bromide (24 mmol) was added dropwise, followed by reaction at 25 °C. The reaction was monitored by gas chromatography. After completion of the reaction, the reaction solution was added to 100 mL of water and extracted twice with 15 mL of toluene solution. The solvent was removed to obtain 3.9 g of 3,6-dimethylfluorene with a GC purity of 99.8%.

[0046] 1H NMR (500 MHz, Chloroform-d) δ 7.58 (s, 2H), 7.41 (d, J = 7.6 Hz, 2H), 7.10 (d, J = 7.6 Hz, 2H), 3.80 (s, 2H), 2.45 (s, 6H).

[0047] Example 9 Preparation of dimethyl(cyclopentadienyl)(3,6-dimethyl-9-fluorenyl)silylzirconium dichloride (catalyst 5) [ka] 3,6-dimethylfluorene (2.8 g, 14.4 mmol) was added to a 100 mL Schlenk flask 1, and the flask was purged with nitrogen gas three times. 35 mL of toluene and 5 mL of tetrahydrofuran were added, and n-BuLi (6.05 mL, 15.1 mmol) was added at -40 °C. The reaction was carried out at 25 °C for 3 h. Furthermore, the atmosphere in a 250 mL Schlenk flask 2 was purged with nitrogen gas three times, and 40 mL of toluene and dimethyldichlorosilane (11.20 g, 86.5 mmol) were added. The solution in flask 1 was added at -25 °C, and the reaction was carried out at 25 °C for 18 h. The reaction solvent was completely aspirated, and 40 mL of toluene was added. The mixture was then completely aspirated again, and 40 mL of toluene was added. Furthermore, a 100 mL Schlenk flask 3 was purged with nitrogen gas three times, and 35 mL of toluene and 5 mL of tetrahydrofuran were added, followed by cyclopentadiene (1.002 g, 14.4 mmol), and then n-BuLi (6.05 mL, 15.1 mmol) at −75° C., followed by reaction for 2 hours at 25° C. Thereafter, the solution in reaction flask 3 was added to flask 2 at −45° C., followed by stirring at 25° C. for 3 hours.

[0048] The reaction solvent was completely aspirated, and 30 mL of toluene and 7.5 mL of ether were added. n-BuLi (11.8 mL, 29.5 mmol) was added at −45° C. and the reaction was continued for 20 h at 25° C. ZrCl4 (3.43 g, 14.6 mmol) was added at −75° C. and the reaction was continued for 3 h at 25° C. The reaction solvent was completely aspirated, and the mixture was washed with toluene (150 mL), filtered, and the filtrate was concentrated to 40 mL. 40 mL of n-hexane was added, filtered, and dried to obtain 0.6 g of a yellow solid.

[0049] 1 H NMR (500 MHz, CDCl3) δ 7.91 (s, 2H), 7.40 (d, J = 8.6 Hz, 2H), 7.14 (dd, J = 8.7, 1.6 Hz, 2H), 6.59 (t, J = 2.4 Hz, 2H), 5.71 (t, J = 2.4 Hz, 2H), 2.61 (s, 6H), 1.11 (s, 6H).

[0050] Example 10 Preparation of 2,7-di(3,5-dimethylphenyl)fluorene [ka] 2,7-Dibromofluorene (3.24 g, 10 mmol), 3,5-dimethylphenylboronic acid (3.19 g, 21.27 mmol), tetrakis(triphenylphosphine)palladium (0.17 g, 0.147 mmol), and anhydrous sodium carbonate (3.20 g, 30.19 mmol) were added to a 100 mL two-neck flask in that order, and the mixture was purged with nitrogen gas three times. 50 mL of ethanol and 4 mL of water were added, and the mixture was refluxed for 24 h. After cooling, 250 mL of water and 100 mL of ethyl acetate were added, and the layers were separated. The organic phase was washed twice with water and dried over anhydrous sodium sulfate. The solvent was then removed to obtain 3.18 g of a solid powder (HPLC purity 98.85%).

[0051] 1H NMR (500 MHz, Chloroform-d) δ 7.84-7.01 (m, 12H), 4.01 (s, 2H), 2.41 (s, 12H).

[0052] Example 11 Preparation of dimethyl(cyclopentadienyl)(2,7-di(3,5-dimethylphenyl)-9-fluorenyl)silylzirconium dichloride (Catalyst 6) [ka] 2,7-di(3,5-dimethylphenyl)fluorene (5.4 g, 14.4 mmol) was added to a 100 mL Schlenk flask 1, and the flask was purged with nitrogen gas three times. 35 mL of toluene and 5 mL of tetrahydrofuran were added, and n-BuLi (6.05 mL, 15.1 mmol) was added at -40 °C. The reaction was carried out at 25 °C for 18 h. Furthermore, the atmosphere in a 250 mL Schlenk flask 2 was purged with nitrogen gas three times, and 40 mL of toluene and dimethyldichlorosilane (11.20 g, 86.5 mmol) were added. The solution in flask 1 was added at -25 °C, and the reaction was carried out at 25 °C for 24 h. The reaction solvent was completely aspirated, and 40 mL of toluene was added. The mixture was then completely aspirated again, and 40 mL of toluene was added. Furthermore, a 100 mL Schlenk flask 3 was purged with nitrogen gas three times, and 35 mL of toluene and 5 mL of tetrahydrofuran were added, followed by cyclopentadiene (1.002 g, 14.4 mmol), and then n-BuLi (6.05 mL, 15.1 mmol) at −75° C., followed by reaction for 2 hours at 25° C. Thereafter, the solution in reaction flask 3 was added to flask 2 at −45° C., followed by stirring at 25° C. for 3 hours.

[0053] The reaction solvent was completely aspirated, and 30 mL of toluene and 7.5 mL of ether were added. n-BuLi (11.8 mL, 29.5 mmol) was added at −45° C. and the reaction was continued for 20 h at 25° C. ZrCl4 (3.43 g, 14.6 mmol) was added at −75° C. and the reaction was continued for 3 h at 25° C. The reaction solvent was completely aspirated, and the mixture was washed with toluene (150 mL), filtered, and the filtrate was concentrated to 40 mL. 40 mL of n-hexane was added, filtered, and dried to obtain 1.43 g of a yellow solid.

[0054] 1 H NMR (500 MHz, CDCl3) δ 7.92-7.05 (m, 12H), 6.60 (t, J = 2.4 Hz, 2H), 5.72 (t, J = 2.4 Hz, 2H), 2.56 (s, 12H), 1.11 (s, 6H).

[0055] Example 12 Preparation of 2,7-di(3,5-di-tert-butylphenyl)fluorene [ka] 2,7-Dibromofluorene (3.24 g, 10 mmol), 3,5-di-tert-butylphenylboronic acid (5.00 g, 21.35 mmol), tetrakis(triphenylphosphine)palladium (0.13 g, 0.11 mmol), and anhydrous sodium carbonate (3.20 g, 30.19 mmol) were added to a 100 mL two-neck flask in that order, and the mixture was purged with nitrogen gas three times. 50 mL of ethanol and 4 mL of water were added, and the mixture was refluxed for 24 h. After cooling, 250 mL of water and 100 mL of ethyl acetate were added, and the layers were separated. The organic phase was washed twice with water and dried over anhydrous sodium sulfate. The solvent was then removed to give 4.08 g of a solid powder (HPLC purity 98.32%).

[0056] 1 H NMR (500 MHz, Chloroform-d) δ 7.89-7.43 (m, 12H), 4.05 (s, 2H), 1.41 (s, 36H).

[0057] Example 13 Preparation of dimethyl(cyclopentadienyl)(2,7-di(3,5-di-tert-butylphenyl)-9-fluorenyl)silylzirconium dichloride (Catalyst 7) [ka] 2,7-di(3,5-di-tert-butylphenyl)fluorene (7.8 g, 14.4 mmol) was added to a 100 mL Schlenk flask 1, and the flask was purged with nitrogen gas three times. 35 mL of toluene and 5 mL of tetrahydrofuran were added, and n-BuLi (6.05 mL, 15.1 mmol) was added at -40 °C. The reaction was carried out at 25 °C for 18 h. Furthermore, the atmosphere in a 250 mL Schlenk flask 2 was purged with nitrogen gas three times, and 40 mL of toluene and dimethyldichlorosilane (11.20 g, 86.5 mmol) were added. The solution in flask 1 was added at -25 °C, and the reaction was carried out at 25 °C for 24 h. The reaction solvent was completely aspirated, and 40 mL of toluene was added. The mixture was then completely aspirated again, and 40 mL of toluene was added. Furthermore, a 100 mL Schlenk flask 3 was purged with nitrogen gas three times, and 35 mL of toluene and 5 mL of tetrahydrofuran were added, followed by cyclopentadiene (1.002 g, 14.4 mmol), and then n-BuLi (6.05 mL, 15.1 mmol) at −75° C., followed by reaction for 2 hours at 25° C. Thereafter, the solution in reaction flask 3 was added to flask 2 at −45° C., followed by stirring at 25° C. for 3 hours.

[0058] The reaction solvent was completely aspirated, and 30 mL of toluene and 7.5 mL of ether were added. n-BuLi (11.8 mL, 29.5 mmol) was added at −45° C. and the reaction was continued for 20 h at 25° C. ZrCl4 (3.43 g, 14.6 mmol) was added at −75° C. and the reaction was continued for 3 h at 25° C. The reaction solvent was completely aspirated, and the mixture was washed with toluene (150 mL), filtered, and the filtrate was concentrated to 40 mL. 40 mL of n-hexane was added, filtered, and dried to obtain 1.6 g of a yellow solid.

[0059] 1H NMR (500 MHz, CDCl3) δ 7.91-7.45 (m, 12H), 6.60 (t, J = 2.4 Hz, 2H), 5.72 (t, J = 2.4 Hz, 2H), 2.55 (s, 36H), 1.11 (s, 6H).

[0060] Example 14 3,6-di(4-tert-butylphenyl)fluorene [ka] 3,6-Dibromofluorene (3.24 g, 10 mmol), 4-tert-butylphenylboronic acid (3.76 g, 21.12 mmol), tetrakis(triphenylphosphine)palladium (0.13 g, 0.11 mmol), and anhydrous sodium carbonate (3.18 g, 30 mmol) were added to a 100 mL two-neck flask in that order, and the mixture was purged with nitrogen gas three times. 50 mL of ethanol and 4 mL of water were added, and the mixture was refluxed for 24 h. After cooling, 250 mL of water and 100 mL of ethyl acetate were added, and the layers were separated. The organic phase was washed twice with water and dried over anhydrous sodium sulfate. The solvent was then removed to obtain 2.36 g of a solid powder (HPLC purity 98.24%).

[0061] 1 H NMR (500 MHz, Chloroform-d) δ 7.84-7.46 (m, 14H), 4.02 (s, 2H), 1.38 (s, 18H).

[0062] Example 15 Preparation of dimethyl(cyclopentadienyl)(3,6-di(4-tert-butylphenyl)-9-fluorenyl)silylzirconium dichloride (Catalyst 8) [ka] 3,6-di(4-tert-butylphenyl)fluorene (6.2 g, 14.4 mmol) was added to a 100 mL Schlenk flask 1, and the flask was purged with nitrogen gas three times. 35 mL of toluene and 5 mL of tetrahydrofuran were added, and n-BuLi (6.05 mL, 15.1 mmol) was added at -40 °C. The reaction was carried out at 25 °C for 18 h. Furthermore, the atmosphere in a 250 mL Schlenk flask 2 was purged with nitrogen gas three times, and 40 mL of toluene and dimethyldichlorosilane (11.20 g, 86.5 mmol) were added. The solution in flask 1 was added at -25 °C, and the reaction was carried out at 25 °C for 24 h. The reaction solvent was completely aspirated, and 40 mL of toluene was added. The mixture was then completely aspirated again, and 40 mL of toluene was added. Furthermore, a 100 mL Schlenk flask 3 was purged with nitrogen gas three times, and 35 mL of toluene and 5 mL of tetrahydrofuran were added, followed by cyclopentadiene (1.002 g, 14.4 mmol), and then n-BuLi (6.05 mL, 15.1 mmol) at −75° C., followed by reaction for 2 hours at 25° C. Thereafter, the solution in reaction flask 3 was added to flask 2 at −45° C., followed by stirring at 25° C. for 3 hours.

[0063] The reaction solvent was completely aspirated, and 30 mL of toluene and 7.5 mL of ether were added. n-BuLi (11.8 mL, 29.5 mmol) was added at −45° C. and the reaction was continued for 20 h at 25° C. ZrCl4 (3.43 g, 14.6 mmol) was added at −75° C. and the reaction was continued for 3 h at 25° C. The reaction solvent was completely aspirated, and the mixture was washed with toluene (150 mL), filtered, and the filtrate was concentrated to 40 mL. 40 mL of n-hexane was added, filtered, and dried to obtain 1.83 g of a yellow solid.

[0064] 1 H NMR (500 MHz, CDCl3) δ 7.86-7.48 (m, 14H), 6.61 (t, J = 2.4 Hz, 2H), 5.73 (t, J = 2.4 Hz, 2H), 2.53 (s, 18H), 1.09 (s, 6H).

[0065] Example 16 Preparation of diphenyl(cyclopentadienyl)(2,7-di(2-methylphenyl)-9-fluorenyl)silylzirconium dichloride (Catalyst 9) [ka] 2,7-di(2-methylphenyl)fluorene (5.0 g, 14.4 mmol) was added to a 100 mL Schlenk flask 1, and the flask was purged with nitrogen gas three times. 35 mL of toluene and 5 mL of tetrahydrofuran were added, and n-BuLi (6.05 mL, 15.1 mmol) was added at -40 °C. The reaction was carried out at 25 °C for 18 h. Furthermore, the atmosphere in a 250 mL Schlenk flask 2 was purged with nitrogen gas three times, and 40 mL of toluene and dimethyldichlorosilane (21.90 g, 86.5 mmol) were added. The solution in flask 1 was added at -25 °C, and the reaction was carried out at 25 °C for 24 h. The reaction solvent was completely aspirated, and 40 mL of toluene was added. The mixture was then completely aspirated again, and 40 mL of toluene was added. Furthermore, a 100 mL Schlenk flask 3 was purged with nitrogen gas three times, and 35 mL of toluene and 5 mL of tetrahydrofuran were added, followed by cyclopentadiene (1.002 g, 14.4 mmol), and then n-BuLi (6.05 mL, 15.1 mmol) at −75° C., followed by reaction for 2 hours at 25° C. Thereafter, the solution in reaction flask 3 was added to flask 2 at −45° C., followed by stirring at 25° C. for 3 hours.

[0066] The reaction solvent was completely aspirated, and 30 mL of toluene and 7.5 mL of ether were added. n-BuLi (11.8 mL, 29.5 mmol) was added at −45° C. and the reaction was continued for 20 h at 25° C. ZrCl4 (3.43 g, 14.6 mmol) was added at −75° C. and the reaction was continued for 3 h at 25° C. The reaction solvent was completely aspirated, and the mixture was washed with toluene (150 mL), filtered, and the filtrate was concentrated to 40 mL. 40 mL of n-hexane was added, filtered, and dried to obtain 2.48 g of a yellow solid.

[0067] 1H NMR (500 MHz, Chloroform-d) δ 8.26 -7.05 (m, 24H), 6.43 (s, 2H), 6.38 (s, 2H), 5.79 (s, 2H), 2.22 (s, 6H).

[0068] Example 17 Preparation of diphenyl(cyclopentadienyl)(2,7-di(2,6-dimethylphenyl)-9-fluorenyl)silylzirconium dichloride (Catalyst 10) [ka] 2,7-di(2,6-dimethylphenyl)fluorene (5.4 g, 14.4 mmol) was added to a 100 mL Schlenk flask 1, and the flask was purged with nitrogen gas three times. 35 mL of toluene and 5 mL of tetrahydrofuran were added, and n-BuLi (6.05 mL, 15.1 mmol) was added at -40 °C. The reaction was carried out at 25 °C for 18 h. Furthermore, the atmosphere in a 250 mL Schlenk flask 2 was purged with nitrogen gas three times, and 40 mL of toluene and dichlorodiphenylsilane (21.90 g, 86.5 mmol) were added. The solution in flask 1 was added at -25 °C, and the reaction was carried out at 25 °C for 24 h. The reaction solvent was completely aspirated, and 40 mL of toluene was added. The mixture was then completely aspirated again, and 40 mL of toluene was added. Furthermore, a 100 mL Schlenk flask 3 was purged with nitrogen gas three times, and 35 mL of toluene and 5 mL of tetrahydrofuran were added, followed by cyclopentadiene (1.002 g, 14.4 mmol), and then n-BuLi (6.05 mL, 15.1 mmol) at −75° C., followed by reaction for 2 hours at 25° C. Thereafter, the solution in reaction flask 3 was added to flask 2 at −45° C., followed by stirring at 25° C. for 3 hours.

[0069] The reaction solvent was completely aspirated, and 30 mL of toluene and 7.5 mL of ether were added. n-BuLi (11.8 mL, 29.5 mmol) was added at −45° C. and the reaction was continued for 20 h at 25° C. ZrCl4 (3.43 g, 14.6 mmol) was added at −75° C. and the reaction was continued for 3 h at 25° C. The reaction solvent was completely aspirated, and the mixture was washed with toluene (150 mL), filtered, and the filtrate was concentrated to 40 mL. 40 mL of n-hexane was added, filtered, and dried to obtain 2.77 g of a yellow solid.

[0070] 1 H NMR (500 MHz, Chloroform-d) δ 8.29-6.97 (m, 22H), 6.45 (s, 2H), 6.37 (s, 2H), 5.83 - 5.73 (m, 2H), 2.07 (s, 6H), 1.99 (s, 6H).

[0071] Example 18 Preparation of dimethyl(cyclopentadienyl)(1,8-dimethyl-9-fluorenyl)silylhafnium dichloride (catalyst 11) [ka] 1,8-dimethylfluorene (2.8 g, 14.4 mmol) was added to a 100 mL Schlenk flask 1, and the flask was purged with nitrogen gas three times. 35 mL of toluene and 5 mL of tetrahydrofuran were added, and n-BuLi (6.05 mL, 15.1 mmol) was added at -40 °C. The reaction was carried out at 25 °C for 3 h. Furthermore, the atmosphere in a 250 mL Schlenk flask 2 was purged with nitrogen gas three times, and 40 mL of toluene and dimethyldichlorosilane (11.20 g, 86.5 mmol) were added. The solution in flask 1 was added at -25 °C, and the reaction was carried out at 25 °C for 18 h. The reaction solvent was completely aspirated, and 40 mL of toluene was added. The mixture was then completely aspirated again, and 40 mL of toluene was added. Furthermore, a 100 mL Schlenk flask 3 was purged with nitrogen gas three times, and 35 mL of toluene and 5 mL of tetrahydrofuran were added, followed by cyclopentadiene (1.002 g, 14.4 mmol), and then n-BuLi (6.05 mL, 15.1 mmol) at −75° C., followed by reaction for 2 hours at 25° C. Thereafter, the solution in reaction flask 3 was added to flask 2 at −45° C., followed by stirring at 25° C. for 3 hours.

[0072] The reaction solvent was completely aspirated, and 30 mL of toluene and 7.5 mL of ether were added. At −45°C, n-BuLi (11.8 mL, 29.5 mmol) was added, and the reaction was continued at 25°C for 20 h. At −75°C, HfCl4 (4.67 g, 14.6 mmol) was added, and the reaction was continued at 25°C for 3 h. The reaction solvent was completely aspirated, and 100 mL of toluene was added. The mixture was heated to 45°C, filtered through Celite while still hot, and the Celite was washed twice with 20 mL of toluene. The filtrate was collected, crystallized at −20°C, and filtered to obtain 1.06 g of an orange solid.

[0073] 1 H NMR (500 MHz, Chloroform-d) δ 7.97- 6.64 (m, 8H), 5.74 (t, J=2.5 Hz, 2H), 2.42 (s, 6H), 1.14(s, 6H).

[0074] Example 19 Preparation of diphenyl(cyclopentadienyl)(2,7-di(2,6-dimethylphenyl)-9-fluorenyl)silylhafnium dichloride (catalyst 12) [ka] 2,7-di(3,5-dimethylphenyl)fluorene (5.4 g, 14.4 mmol) was added to a 100 mL Schlenk flask 1, and the flask was purged with nitrogen gas three times. 35 mL of toluene and 5 mL of tetrahydrofuran were added, and n-BuLi (6.05 mL, 15.1 mmol) was added at -40 °C. The reaction was carried out at 25 °C for 18 h. Furthermore, the atmosphere in a 250 mL Schlenk flask 2 was purged with nitrogen gas three times, and 40 mL of toluene and dimethyldichlorosilane (11.20 g, 86.5 mmol) were added. The solution in flask 1 was added at -25 °C, and the reaction was carried out at 25 °C for 24 h. The reaction solvent was completely aspirated, and 40 mL of toluene was added. The mixture was then completely aspirated again, and 40 mL of toluene was added. Furthermore, a 100 mL Schlenk flask 3 was purged with nitrogen gas three times, and 35 mL of toluene and 5 mL of tetrahydrofuran were added, followed by cyclopentadiene (1.002 g, 14.4 mmol), and then n-BuLi (6.05 mL, 15.1 mmol) at −75° C., followed by reaction for 2 hours at 25° C. Thereafter, the solution in reaction flask 3 was added to flask 2 at −45° C., followed by stirring at 25° C. for 3 hours.

[0075] The reaction solvent was completely aspirated, and 30 mL of toluene and 7.5 mL of ether were added. n-BuLi (11.8 mL, 29.5 mmol) was added at −45° C. and the reaction was continued for 20 h at 25° C. ZrCl4 (3.43 g, 14.6 mmol) was added at −75° C. and the reaction was continued for 3 h at 25° C. The reaction solvent was completely aspirated, and the mixture was washed with toluene (150 mL), filtered, and the filtrate was concentrated to 40 mL. 40 mL of n-hexane was added, filtered, and dried to obtain 1.43 g of a yellow solid.

[0076] 1H NMR (500 MHz, Chloroform-d) δ 8.31-6.98 (m, 22H), 6.54 (s, 2H), 6.43 (s, 2H), 5.85 - 5.75 (m, 2H), 2.09 (s, 6H), 1.88 (s, 6H).

[0077] (Comparative Example 1) Preparation of dimethyl(cyclopentadienyl)(9-fluorenyl)silylzirconium dichloride (catalyst 13) [ka] Fluorene (2.8 g, 16.6 mmol) was added to a 100 mL Schlenk flask 1, and the flask was purged with nitrogen gas three times. 35 mL of toluene and 5 mL of tetrahydrofuran were added, and n-BuLi (7 mL, 17.5 mmol) was added at -40 °C. The reaction was carried out for 3 h at 25 °C. Furthermore, the atmosphere in a 250 mL Schlenk flask 2 was purged with nitrogen gas three times, and 40 mL of toluene was added. dimethyldichlorosilane (12.9 g, 100 mmol) was added, and the solution in flask 1 was added at -25 °C. The reaction was carried out for 18 h at 25 °C. The reaction solvent was completely aspirated, and 40 mL of toluene was added. The mixture was then completely aspirated again, and 40 mL of toluene was added. Furthermore, a 100 mL Schlenk flask 3 was purged with nitrogen gas three times, and 35 mL of toluene and 5 mL of tetrahydrofuran were added, followed by cyclopentadiene (1.10 g, 16.6 mmol), and then n-BuLi (7 mL, 17.5 mmol) at −75° C., followed by reaction for 2 hours at 25° C. Thereafter, the solution in reaction flask 3 was added to flask 2 at −45° C., followed by stirring at 25° C. for 3 hours.

[0078] The reaction solvent was completely aspirated, and 30 mL of toluene and 7.5 mL of ether were added. n-BuLi (13.6 mL, 34 mmol) was slowly added at -45 °C, and the reaction was continued at 25 °C for 20 h. ZrCl4 (3.96 g, 17.0 mmol) was added at -75 °C, and the reaction was continued at 25 °C for 20 h. The reaction solvent was completely aspirated, and 100 mL of toluene was added at 55 °C. The mixture was filtered through Celite while still hot, and the Celite was washed twice with 20 mL of toluene. The filtrate was collected, crystallized at -40 °C, and filtered to obtain approximately 1.05 g of an orange solid.

[0079] 1 H NMR (500 MHz, Chloroform-d) δ 8.12 (d, J = 8.3 Hz, 2H), 7.67 - 7.59 (m, 2H), 7.54 (d, J = 8.6 Hz, 2H), 7.33 - 7.25 (m, 3H), 6.61 (t, J = 2.4 Hz, 2H), 5.75 (t, J = 2.4 Hz, 2H), 1.14 (s, 6H).

[0080] (Comparative Example 2) Preparation of dimethyl(cyclopentadienyl)(2,7-di-tert-butyl-9-fluorenyl)silylzirconium dichloride (catalyst 14) [ka] 2,7-di-tert-butylfluorene (3 g, 10.8 mmol) was added to a 100 mL Schlenk flask 1, and the flask was purged with nitrogen gas three times. 22 mL of toluene and 3 mL of tetrahydrofuran were added, and n-BuLi (4.5 mL, 11.34 mmol) was added at -40 °C. The reaction was carried out at 25 °C for 3 h. Furthermore, the atmosphere in a 250 mL Schlenk flask 2 was purged with nitrogen gas three times, and 30 mL of toluene and dimethyldichlorosilane (8.8 g, 64.8 mmol) were added. The solution in flask 1 was added at -25 °C, and the reaction was carried out at 25 °C for 18 h. The reaction solvent was completely aspirated, and 40 mL of toluene was added. The mixture was then completely aspirated again, and 40 mL of toluene was added. Furthermore, a 100 mL Schlenk flask 3 was purged with nitrogen gas three times, and 22 mL of toluene and 3 mL of tetrahydrofuran were added, followed by cyclopentadiene (0.75 g, 10.8 mmol), and then n-BuLi (4.5 mL, 11.34 mmol) at −75° C., followed by reaction for 2 hours at 25° C. Thereafter, the solution in reaction flask 3 was added to flask 2 at −45° C., followed by stirring at 25° C. for 3 hours.

[0081] The reaction solvent was completely aspirated, and 30 mL of toluene and 7.5 mL of ether were added. n-BuLi (11.8 mL, 29.5 mmol) was added at −45° C. and the reaction was continued for 20 h at 25° C. ZrCl4 (2.51 g, 10.8 mmol) was added at −75° C. and the reaction was continued for 3 h at 25° C. The reaction solvent was completely aspirated, and the mixture was washed with toluene (150 mL), filtered, and the filtrate was concentrated to 40 mL. n-hexane was added, filtered, and dried to obtain 1.01 g of a yellow solid.

[0082] 1 H NMR (500 MHz, Chloroform-d) δ 7.99 (d, J=7.9 Hz, 2H), 7.71 (dd, J=8.8, 1.7 Hz, 2H), 7.43 (s, 2H), 6.60 (t, J=2.4 Hz, 2H), 5.66 (t, J=2.4 Hz, 2H), 1.35 (s, 18H), 1.15 (s, 6H).

[0083] Examples 20 to 38 Catalysts 1 to 12 catalyze the polymerization of propylene.

[0084] 150 mL of n-hexane was added to a 1 L reactor, followed by MAO (30% by mass in toluene) and a catalyst in toluene solution (concentration 0.5 g / L). The mixture was stirred for 5 minutes, and 1.0 MPa propylene was introduced. After 1 hour, ethanol (50 mL) was added to terminate the reaction. The polymer was washed with ethanol, filtered, and vacuum dried to obtain polypropylene. The polymerization activity was calculated. 13 The syndiotacticity (rrrr) of polypropylene was calculated by C NMR. The weight average molecular weight M w The polymerization data are shown in Table 1.

[0085] [Table 1]

[0086] (Comparative Examples 3 to 7) Catalyst 13 and catalyst 14 catalyze the polymerization of propylene.

[0087] 150 mL of n-hexane was added to a 1 L reactor, followed by MAO (30% by mass in toluene) and a catalyst in toluene solution (concentration 1.0 g / L). The mixture was stirred for 5 minutes, and 1.0 MPa propylene was introduced. After 1 hour, ethanol (50 mL) was added to terminate the reaction. The polymer was washed with ethanol, filtered, and vacuum dried to obtain polypropylene. The polymerization activity was calculated. 13 The syndiotacticity (rrrr) of polypropylene was calculated by C NMR. The weight average molecular weight M w The polymerization data are shown in Table 2.

[0088] [Table 2]

[0089] As can be seen from Tables 1 and 2, the weight-average molecular weight of the polypropylene obtained with catalyst 13 was low, and the presence of the 1-methyl group in catalyst 1 not only improved the weight-average molecular weight of the resulting polypropylene, but also improved the polymerization activity. The presence of 2-methyl, 3-methyl, 2,7-dimethyl, and 3,5-dimethyl groups similarly improved the weight-average molecular weight of the resulting polypropylene. The polypropylene obtained with catalyst 14 had a high weight-average molecular weight, but significantly reduced syndiotacticity. The presence of 1-methyl, 2-methyl, 3-methyl, 2,7-dimethyl, and 3,5-dimethyl groups in catalysts 1 to 5 resulted in high syndiotacticity of the resulting polypropylene, higher than that of the polypropylene obtained with catalyst 13. Similarly, the presence of the 2,7-diaryl group in catalysts 6, 7, and 8 resulted in significantly higher weight-average molecular weights of the resulting polypropylene than those obtained with catalysts 13 and 14. Furthermore, the polypropylenes obtained using catalysts 6, 7, and 8 have high syndiotacticity. When the crosslinking group is a diphenyl silicon crosslinking group or the metal atom is hafnium, the weight average molecular weight and polymerization activity of the polypropylenes obtained using catalysts 9 to 12 are both improved.

[0090] The above-described description of the embodiments is intended to facilitate understanding and use of the invention by those skilled in the art. Those skilled in the art can easily make various modifications to these embodiments and can apply the general principles described herein to other embodiments without creative effort. Therefore, the present invention is not limited to the above-described embodiments. All improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the present invention should fall within the scope of protection of the present invention.

Claims

1. A silicon-bridged metallocene catalyst having a structure represented by the following general formula (I): 【Chemistry 1】 where M is a Group 4 transition metal element; L is a monovalent anionic ligand; X is C １ ~C １０ an unsubstituted or substituted alkyl group, a phenyl group, or 1 to 3 C １ ~C １０ is an aryl group containing an unsubstituted or substituted alkyl group of the formula R １ and R ８ are independently hydrogen, a trifluoromethyl group, a phenyl group, a halogen, C ５ ~C １０ an unsubstituted or substituted cycloalkyl group of the formula C １ ~C １０ an unsubstituted or substituted alkyl group of the formula C １ ~C １０ an unsubstituted or substituted alkoxy group of the formula １ ~C １０ an amino group containing an unsubstituted or substituted alkyl group of the formula １ ~C １０ a silicon group containing an unsubstituted or substituted alkyl group of the formula: １ ~C １０ and unsubstituted or substituted heteroaryl groups containing unsubstituted or substituted alkyl groups of the formula: R ２ , R ３ , R ６ and R ７ are independently hydrogen, a trifluoromethyl group, a phenyl group, a naphthyl group, an anthryl group, a phenanthryl group, a halogen, C ５ ~C １０ an unsubstituted or substituted cycloalkyl group of the formula C １ ~C １０ an unsubstituted or substituted alkyl group of the formula C １ ~C １０ an unsubstituted or substituted alkoxy group of the formula １ ~C １０ an amino group containing an unsubstituted or substituted alkyl group of the formula １ ~C １０ a silicon group containing an unsubstituted or substituted alkyl group of the formula: １ ~C １０ aryl groups containing an unsubstituted or substituted alkyl group of the formula: R ４ and R ５ are independently hydrogen, a trifluoromethyl group, a halogen, C １ ~C １０ an unsubstituted or substituted alkyl group of the formula C １ ~C １０ an unsubstituted or substituted alkoxy group of the formula １ ~C １０ an amino group containing an unsubstituted or substituted alkyl group of the formula １ ~C １０ The silicon group containing the unsubstituted or substituted alkyl group is selected from the group consisting of: A silicon-bridged metallocene catalyst characterized by:

2. M is zirconium or hafnium; The silicon-bridged metallocene catalyst according to claim 1 .

3. L is halogen or C １ ~C １０ is an unsubstituted or substituted alkyl group of the formula The silicon-bridged metallocene catalyst according to claim 1 .

4. X is C １ ~C ６ an unsubstituted or substituted alkyl group, a phenyl group, or 1 to 3 C １ ~C ６ is an aryl group containing an unsubstituted or substituted alkyl group of the formula: The silicon-bridged metallocene catalyst according to claim 1 .

5. R １ and R ８ are independently hydrogen, a trifluoromethyl group, and C １ ~C ６ and is selected from the unsubstituted or substituted alkyl groups R ２ , R ３ , R ６ and R ７ are independently hydrogen, a phenyl group, a naphthyl group, C １ ~C １０ an unsubstituted or substituted alkyl group of the formula １ ~C １０ a silicon group containing an unsubstituted or substituted alkyl group of the formula: １ ~C １０ and unsubstituted or substituted aryl groups containing unsubstituted or substituted alkyl groups of the formula: R ４ and R ５ are independently hydrogen and C １ ~C １０ unsubstituted or substituted alkyl selected from the group consisting of The silicon-bridged metallocene catalyst according to claim 1 .

6. Use of the silicon-bridged metallocene catalyst according to any one of claims 1 to 5 in the manufacture of a catalyst system for the polymerization of olefins.

7. an activator, an inert carrier, and the silicon-bridged metallocene catalyst of any one of claims 1 to 5; Catalyst systems for olefin polymerization.

8. the activator is one or more selected from aluminoxanes, alkyl aluminums, and borates; 8. A catalyst system for olefin polymerization according to claim 7.

9. The inert carrier is one or more selected from a silicon-containing inorganic porous carrier, an aluminum-containing inorganic porous carrier, a magnesium-containing inorganic porous carrier, and a polymeric organic porous carrier; 8. A catalyst system for olefin polymerization according to claim 7.

10. 1) adding the catalyst system of claim 7 to a reactor; 2) after adding the catalyst system, introducing propylene monomer into the reactor and contacting it with the catalyst system; and 3) maintaining the polymerization conditions to obtain a propylene polymer. A method for producing a propylene polymer, comprising:

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