CN102603935B - Metal bridging bis-guanyl zirconium catalyst and preparation method and application thereof - Google Patents

Abstract

The invention provides a metal bridging bis-guanyl zirconium catalyst and a preparation method of the metal bridging bis-guanyl zirconium catalyst, in particular relates to a guanyl ligand zirconium complex catalyst taking zirconium as a central atom and having N-C-N characteristic. The preparation method comprises the following steps: using cyclohexane as a starting material under the protection of nitrogen, converting the cyclohexane to a lithium salt by utilizing butyl lithium, then adding cyanophenyl for an addition reaction, then reacting the ligand with zirconium tetrachloride, and then reacting with butyl lithium to prepare the metal bridging bis-guanyl zirconium catalyst. The synthetic method has wide applicability, the reaction condition is mild, materials are easily accessible, the price is low, the steps are simple, and the yield is high. The catalyst has good catalytic activity for a vinyl polymerization reaction.

Description

Metal-bridged bis-amidino zirconium catalyst and its preparation method and application

technical field

The invention relates to a transition metal catalyst for ethylene polymerization, in particular to a metal-bridged bisamidinyl zirconium catalyst with an N-C-N skeleton and a preparation method and application thereof.

Background technique

At present, industrialized olefin polymerization catalysts include Ziegler-Natta catalysts, Phillips catalysts and metallocene catalysts, etc. These catalysts can control the catalytic activity and polymer properties by adjusting the structure of the ligand. Brintzinger reported that a class of bridged metallocene catalysts not only has high activity, but also can control the stereo configuration of polymers (H. Schnutenhaus, H.H. Brintzinger, Angew. Chem, Int. Ed., 1979, 18, 777.). However, they all have defects such as harsh synthesis conditions and low total catalyst yield. In addition, the storage conditions of the catalyst are also very harsh, easy to deactivate, and the synthesis method is complicated, and the raw materials are not suitable for preparation. Therefore, new non-metallocene catalysts It has become a research hotspot in recent years. Not long ago, our research group designed a class of bridged diamidinyl ligands and successfully explored its preparation route (Sheng-Di Bai, Jian-Ping Guo, Dian-Sheng Liu, Dalton Trans., 2006, 2244. ), further using this kind of ligands to synthesize bridged bis-amidino Group IV metal compounds, a new type of non-metallocene catalytic system can be obtained. , the reaction conditions are milder, easy to store, and has two activation centers, so the development and research of this new type of high-efficiency metal-bridged bis-amidino zirconium catalyst has practical value.

Contents of the invention

The object of the present invention is to provide a metal-bridged bisamidinyl zirconium catalyst, which has simple synthesis method, mild reaction conditions, easy-to-obtain raw materials, and good catalytic activity for ethylene polymerization.

A kind of metal-bridged bisamidinyl zirconium catalyst provided by the invention, its structural formula is:

The present invention also provides a kind of preparation method of metal-bridged bisamidinyl zirconium catalyst, comprising the steps of:

Under the protection of nitrogen and ice-water bath, cyclohexylamine and n-butyllithium are mixed and reacted according to the molar ratio of 1:1, the solvent is tetrahydrofuran, and its volume is 20-25 times of the volume of n-butyllithium, stirred, and naturally heated to Keep stirring at room temperature for 2-3 hours to obtain a lithiated product solution, place the resulting solution under an ice-water bath, then add benzonitrile equivalent to one times the molar ratio of the lithiated product to the above solution, stir, and naturally heat up to Keep stirring at room temperature for 5-6 hours to obtain the addition product; place the addition product under an ice-water bath, add zirconium tetrachloride equivalent to one times the molar ratio of the addition product in the previous step, naturally warm up to room temperature, and keep stirring After reacting for 5-6 hours, place the obtained product under an ice-water bath, add butyllithium in a molar ratio of one time, naturally raise the temperature to room temperature, and keep stirring for 2-3 hours to obtain a metal-bridged bisamidozirconium catalyst.

Compared with the prior art, the advantages and effects of the present invention are: the raw materials used in the synthesis catalyst of the present invention are simple and easy to obtain, the price is low, the preparation method is simple, and the yield is high, and there are two activation centers; the catalyst is used for ethylene polymerization. catalytic activity.

Description of drawings

The single crystal X-ray structure figure of Fig. 1 metal bridged bisamidinyl zirconium catalyst of the present invention

Detailed ways

The following are only specific examples given to describe the present invention in detail, and these examples are not intended to limit the protection scope of the present invention.

Preparation and characterization of embodiment 1 catalyst

(1) Preparation of metal-bridged bis-amidino zirconium catalyst

D_x＝1.431g/cm³，and Z＝4，μ(Mo-Kα)＝0.760mm^-1，R₁＝0.0671，wR₂＝0.1604。单晶X射线结构图见图1。Under the protection of nitrogen and ice-water bath, cyclohexylamine (0.68ml, 5.88mmol) was dissolved in tetrahydrofuran (15cm ³ ), and under stirring, a n-hexane solution of butyllithium (2.2mol·dm ^{- 3} , 2.67cm ³ , 5.88mmol), and continue to stir for 2 hours after the reaction mixture returns to room temperature, cool the reaction solution to 0°C, add benzonitrile (0.59cm3, 5.88mmol) with a syringe, and wait for the reaction mixture to return to Continue stirring for 5 hours after room temperature, then cool the reaction solution to 0°C, add zirconium tetrachloride (1.43g, 5.88mmol), continue stirring for 5 hours after the reaction mixture returns to room temperature, and cool the reaction solution to 0°C. Slowly add n-hexane solution of butyllithium (2.2mol·dm ^-3 , 2.67cm ³ , 5.88mmol), and continue to stir for 2 hours after the reaction mixture returns to room temperature. Dissolve in toluene, filter, concentrate the filtrate, add a small amount of tetrahydrofuran, and crystallize to obtain a white crystalline metal-bridged bisamidinyl zirconium catalyst. The yield was 92%. partial bond length Bond angle (°): Zr(1)-N(3)2.242(6), Zr(1)-N(2)2.265(6), Zr(1)-O(1)2.282(5), Zr (1)-N(1) 2.284(6), Zr(1)-N(4) 2.297(6), Zr(1)-Cl(2) 2.403(2), Zr(1)-Cl(1) 2.471(2), Zr(1)-C(14) 2.654(8)Zr(1)-C(7) 2.694(8), Zr(1)-Zr(2) 3.2510(13), Zr(2) -N(2) 1.981(6), Zr(2)-N(3) 1.987(6), Zr(2)-O(3) 2.324(6), Zr(2)-O(2) 2.333(6) ), Zr(2)-Cl(4) 2.453(3), Zr(2)-Cl(3) 2.482(2), N(3)-Zr(1)-N(2) 73.8(2), N (3)-Zr(1)-O(1) 85.9(2), N(2)-Zr(1)-O(1) 83.6(2), N(3)-Zr(1)-N(1 )132.6(2), N(2)-Zr(1)-N(1) 58.9(2), O(1)-Zr(1)-N(1) 90.0(2), N(3)-Zr (1)-N(4) 59.3(2), N(2)-Zr(1)-N(4) 132.8(2), O(1)-Zr(1)-N(4) 88.3(2) , N(1)-Zr(1)-N(4) 167.8(2), N(3)-Zr(1)-Cl(2) 93.86(16), N(2)-Zr(1)-Cl (2)97.03(16), O(1)-Zr(1)-Cl(2) 179.28(16), N(1)-Zr(1)-Cl(2) 90.68(16), N(4) -Zr(1)-Cl(2) 90.96(17)N(3)-Zr(1)-Cl(1) 140.84(17), N(2)-Zr(1)-Cl(1) 140.33(16 ), O(1)-Zr(1)-Cl(1) 81.62(14), N(1)-Zr(1)-Cl(1) 84.49(16), N(4)-Zr(1)- Cl(1) 83.31(18), Cl(2)-Zr(1)-Cl(1) 98.16(8)N(3)-Zr(1)-C(14) 30.3(2), N(2) -Zr(1)-C(14) 104.0(2), O(1)-Zr(1)-C(14) 90.8(2), N(1)-Zr(1)-C(14) 162.7( 2), N(4)-Zr(1)-C(14) 29.5(2), Cl(2 )-Zr(1)-C(14) 88.64(17)Cl(1)-Zr(1)-C(14) 112.8(2), N(3)-Zr(1)-C(7) 103.6( 2), N(2)-Zr(1)-C(7) 29.87(19), O(1)-Zr(1)-C(7) 87.7(2), N(1)-Zr(1) -C(7) 29.06(19), N(4)-Zr(1)-C(7) 162.6(2)Cl(2)-Zr(1)-C(7) 93.03(16), Cl(1 )-Zr(1)-C(7) 112.76(17), C(14)-Zr(1)-C(7) 133.7(2), N(3)-Zr(1)-Zr(2) 36.96 (16), N(2)-Zr(1)-Zr(2) 36.90(14), O(1)-Zr(1)-Zr(2) 85.03(13)N(1)-Zr(1) -Zr(2) 95.70(15), N(4)-Zr(1)-Zr(2) 96.19(17), Cl(2)-Zr(1)-Zr(2) 95.19(6), Cl( 1)-Zr(1)-Zr(2) 166.64(6), C(14)-Zr(1)-Zr(2) 67.13(19), C(7)-Zr(1)-Zr(2) 66.64(16)N(2)-Zr(2)-N(3) 86.0(2), N(2)-Zr(2)-O(3) 96.5(2), N(3)-Zr(2 )-O(3) 176.4(2), N(2)-Zr(2)-O(2) 176.5(2), N(3)-Zr(2)-O(2) 97.3(2), O (3)-Zr(2)-O(2) 80.1(2)N(2)-Zr(2)-Cl(4) 96.82(18), N(3)-Zr(2)-Cl(4) 99.13(19), O(3)-Zr(2)-Cl(4) 83.09(17), O(2)-Zr(2)-Cl(4) 83.47(18), N(2)-Zr( 2)-Cl(3) 97.09(18), N(3)-Zr(2)-Cl(3) 94.89(18)O(3)-Zr(2)-Cl(3) 82.33(17), O (2)-Zr(2)-Cl(3) 81.86(19), Cl(4)-Zr(2)-Cl(3) 160.86(9), N(2)-Zr(2)-Zr(1 ) 43.37(16), N(3)-Zr(2)-Zr(1) 42.73(17), O(3)-Zr(2)-Zr(1) 139.87(15)O(2)-Zr( 2)-Zr(1) 140.02(16), Cl(4 )-Zr(2)-Zr(1) 98.93(7), Cl(3)-Zr(2)-Zr(1) 100.21(6), C(7)-N(1)-Zr(1) 93.1 (4), C(1)-N(1)-Zr(1) 141.2(5), C(7)-N(2)-Zr(2) 165.5(5)C(7)-N(2) -Zr(1) 93.0(4), Zr(2)-N(2)-Zr(1) 99.7(2), C(14)-N(3)-Zr(2) 166.2(6), C( 14)-N(3)-Zr(1) 92.1(5), Zr(2)-N(3)-Zr(1) 100.3(3), C(14)-N(4)-Zr(1) 90.6(5)C(21)-N(4)-Zr(1) 142.2(5), C(27)-O(1)-Zr(1) 124.6(5), C(30)-O(1 )-Zr(1) 125.1(5), C(31)-O(2)-Zr(2) 124.4(7), C(34)-O(2)-Zr(2) 128.9(7), C (38)-O(3)-Zr(2) 123.2(6)C(35)-O(3)-Zr(2) 129.5(7), N(1)-C(7)-Zr(1) 57.8(4), N(2)-C(7)-Zr(1) 57.1(4), C(8)-C(7)-Zr(1) 175.0(5), N(4)-C( 14)-Zr(1) 59.9(4), N(3)-C(14)-Zr(1) 57.6(4)C(15)-C(14)-Zr(1) 168.2(5) crystal parameters : Chemical formula C ₃₈ H ₅₆ C ₁₂₄ N ₄ O ₃ Zr ₂ , monoclinic crystal system, space group P2(1)/n, unit cell parameter a=10.601(4)Ab=17.226(6)A c=24.093(9 )Aα=90°, β=96.936(8)°, γ=90°,

D _x = 1.431 g/cm ³ , and Z = 4, μ(Mo-Kα) = 0.760 mm ^-1 , R ₁ = 0.0671, wR ₂ = 0.1604. The single crystal X-ray structure diagram is shown in Figure 1.

Example 2

1. The preparation of catalyst is the same as in Example 1.

2. Ethylene polymerization: Vacuumize a 250 ml stainless steel kettle equipped with a mechanical stirrer and a thermocouple, replace it with nitrogen for 3 times, and then replace it with ethylene for 2 times. After heating up to 50°C, add catalyst (4.9mg, 5μmol) in toluene solution and a certain amount of toluene in sequence, then add methylaluminoxane (2.4mol/L, 1.04ml) to make Al/Zr=500, and finally add a certain amount of Measure the total volume of toluene to 100 mL. The ethylene pressure was immediately raised to 10 atm and stirred vigorously at 50°C for 40 minutes. The reaction solution was poured out, neutralized by adding 5% hydrochloric acid ethanol solution, and a white solid was precipitated, which was filtered and dried naturally. 0.4465 g of the product was obtained, and the polymerization activity was 1.33×10 ⁵ g·mol(Zr) ^-1 ·h ^-1 .

Example 3

1. The preparation of catalyst is the same as in Example 1.

2. Ethylene polymerization: Vacuumize a 250 ml stainless steel kettle equipped with a mechanical stirrer and a thermocouple, replace it with nitrogen for 3 times, and then replace it with ethylene for 2 times. After the temperature was raised to 50°C, the toluene solution of catalyst 2a (4.8mg, 5μmol) and a certain amount of toluene were sequentially added, and then methylaluminoxane (2.4mol/L, 2.1ml) was added to make Al/Zr=1000, and finally The total volume of a certain amount of toluene is 100 ml. The ethylene pressure was immediately raised to 10 atm and stirred vigorously at 50°C for 40 minutes. The reaction solution was poured out, neutralized by adding 5% hydrochloric acid ethanol solution, and a white solid was precipitated. Filter and dry naturally. 0.6175 g of the product was obtained, and the polymerization activity was 1.84×10 ⁵ g·mol(Zr) ^-1 ·h ^-1 .

Example 4

1. The preparation of catalyst is the same as in Example 1.

2. Ethylene polymerization: Vacuumize a 250 ml stainless steel kettle equipped with a mechanical stirrer and a thermocouple, replace it with nitrogen for 3 times, and then replace it with ethylene for 2 times. After the temperature was raised to 50°C, the toluene solution of catalyst 2a (4.8mg, 5μmol) and a certain amount of toluene were sequentially added, and then methylaluminoxane (2.4mol/L, 3.2ml) was added to make Al/Zr=1500, and finally The total volume of a certain amount of toluene is 100 ml. The ethylene pressure was immediately raised to 10 atm and stirred vigorously at 50°C for 40 minutes. The reaction solution was poured out, neutralized by adding 5% hydrochloric acid ethanol solution, and a white solid was precipitated. Filter and dry naturally. 0.6265 g of the product was obtained, and the polymerization activity was 1.87×10 ⁵ g·mol(Zr) ^-1 ·h ^-1 .

Example 5

1. The preparation of catalyst is the same as in Example 1.

2. Ethylene polymerization: Vacuumize a 250 ml stainless steel kettle equipped with a mechanical stirrer and a thermocouple, replace it with nitrogen for 3 times, and then replace it with ethylene for 2 times. After heating up to 50°C, add catalyst (5.0mg, 5μmol) in toluene solution and a certain amount of toluene in sequence, then add methylaluminoxane (2.4mol/L, 4.2ml) to make Al/Zr=2000, and finally add a certain amount of Measure the total volume of toluene to 100 mL. The ethylene pressure was immediately raised to 10 atm and stirred vigorously at 50°C for 40 minutes. The reaction solution was poured out, neutralized by adding 5% hydrochloric acid ethanol solution, and a white solid was precipitated. Filter and dry naturally. 0.8427 g of the product was obtained, and the polymerization activity was 2.52×10 ⁵ g·mol(Zr) ^-1 ·h ^-1 .

Example 6

1. The preparation of catalyst is the same as in Example 1.

2. Ethylene polymerization: Vacuumize a 250 ml stainless steel kettle equipped with a mechanical stirrer and a thermocouple, replace it with nitrogen for 3 times, and then replace it with ethylene for 2 times. After raising the temperature to 70°C, sequentially add the toluene solution of catalyst 2a (5.0 mg, 5 μmol) and a certain amount of toluene, then add methylaluminoxane (2.4mol/L, 5.2ml) to make Al/Zr=2500, and finally add The total volume of a certain amount of toluene is 100 ml. The ethylene pressure was immediately raised to 10 atm and stirred vigorously at 50°C for 40 minutes. The reaction solution was poured out, neutralized by adding 5% hydrochloric acid ethanol solution, and a white solid was precipitated. Filter and dry naturally. 0.7244 g of the product was obtained, and the polymerization activity was 2.16×10 ⁵ g·mol(Zr) ^-1 ·h ^-1 .

Claims (3)

1. two amidino groups Zr catalysts of a metal bridging is characterized in that structural formula is:

2. the preparation method of the two amidino groups Zr catalysts of a kind of metal bridging as claimed in claim 1, is characterized in that, comprises the steps:

Under the protection and ice-water bath of nitrogen, by hexahydroaniline and n-Butyl Lithium, according to 1: 1 hybrid reaction of mol ratio, solvent is tetrahydrofuran (THF), the 20-25 that its volume is the n-Butyl Lithium volume doubly, stirs, and naturally is warmed up to room temperature, keep stirring reaction 2-3 hour, obtain lithiated product solution, gained solution is placed under ice-water bath, then in above-mentioned solution, add the cyanobenzene that is equivalent to one times of mol ratio of lithiated product, stir, naturally be warmed up to room temperature, keep stirring reaction 5-6 hour, obtain adduct; Adduct is placed under ice-water bath again, add the zirconium tetrachloride that is equivalent to one times of mol ratio of previous step adduct, naturally be warmed up to room temperature, keep stirring reaction 5-6 hour, the product obtained is placed under ice-water bath again, adds the butyllithium of one times of mol ratio, naturally is warmed up to room temperature, keep stirring reaction 2-3 hour, obtain the two amidino groups Zr catalysts of metal bridging.

3. the two application of amidino groups Zr catalyst in vinyl polymerization of metal bridging as claimed in claim 1.

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