CN111116787B - Diamine ligand, diamine complex, and catalyst comprising diamine complex - Google Patents

Abstract

The invention discloses a diamine ligand which has a structure shown in a formula I, wherein R in the formula I¹‑R¹⁰Each independently selected from H, halogen, C₁‑C₂₄Saturated or unsaturated hydrocarbon groups and C₁‑C₂₄Saturated or unsaturated hydrocarbyloxy radicals, R¹‑R³、R⁹、R¹⁰Optionally form a ring with each other, R⁴‑R⁸Optionally forming a ring with each other; r₁‑R₄Each independently selected from H, halogen and C₁‑C₃₀A saturated or unsaturated hydrocarbon group, said C₁‑C₃₀The saturated or unsaturated hydrocarbon group being optionally substituted by substituents R₁‑R₄Optionally forming a ring with each other. The complex formed by the diamine ligand has high catalytic activity when applied to olefin polymerization, and the molecular weight distribution of the obtained product is narrow.

Description

Diamine ligand, diamine complex, and catalyst comprising diamine complex

Technical Field

The invention relates to a diamine ligand, a diamine complex and a catalyst containing the diamine complex.

Background

China is the country with the fastest increase of the consumption of synthetic resin and the largest import country of the synthetic resin, and the polyolefin yield accounts for nearly 60 percent at present. Compared with other resin materials, the olefin resin has excellent environmental compatibility, is used as a material for important popularization in the automobile industry of developed countries, and has the worldwide production of 8330 ten thousand tons in 2003, wherein polyethylene is synthetic resin which is fastest in development, has the largest production and extremely wide application, and has the quantity of 5110 ten thousand tons in the same year. The industrial polyethylene catalyst includes Ziegler-Natta catalyst, Phillips catalyst, metallocene catalyst and late transition metal complex catalyst for high efficiency ethylene oligomerization and polymerization.

Nickel alpha-diimine catalysts are of great interest because of their high activity and because the molecular weight and degree of branching of the polymer can be controlled over a wide range. The alpha-nickel diimine catalyst can catalyze oligomerization or polymerization of ethylene with high activity at normal temperature or low temperature under the action of methylaluminoxane or alkylaluminium. However, the molecular weight distribution of the polymer obtained by using the nickel diimine catalyst is wide, and the active polymerization is difficult to realize; diamine complexes have been studied to prepare polymers having a low molecular weight distribution, but the diamine complexes have low catalytic activity. The current post-transition metal catalyst ethylene living polymerization modes are one mode of reducing the polymerization temperature and limiting the occurrence of chain transfer at low temperature (<5 ℃) to achieve living polymerization, and the other mode of inhibiting the chain transfer by increasing the steric hindrance of a ligand to achieve the living polymerization at higher temperature. However, too low a temperature is not suitable for the existing industrial reaction device, and too large ligand steric hindrance makes the design synthesis of the catalyst more difficult. Therefore, the development and synthesis of the high-temperature resistant active polymerization catalyst are simple, and the important significance is achieved.

Disclosure of Invention

The invention provides a novel diamine ligand, when the complex formed by the diamine ligand is applied to olefin polymerization, the complex can have high activity at higher temperature to obtain a polymer with narrow molecular weight distribution, and when the complex is used for catalyzing olefin active polymerization, polyolefins with different molecular weights can be prepared by adjusting the structure and polymerization conditions of the complex.

According to a first aspect of the present invention, there is provided a diamine ligand having the structure shown in formula i:

in the formula I, R¹-R¹⁰Each independently selected from H, halogen, C₁-C₃₀Saturated or unsaturated hydrocarbon groups and C₁-C₃₀Saturated or unsaturated hydrocarbyloxy radicals, R¹-R³、R⁹、R¹⁰Optionally form a ring with each other, R⁴-R⁶、R⁷、R⁸Optionally forming a ring with each other; r₁-R₄Each independently selected from H, halogen and C₁-C₃₀A saturated or unsaturated hydrocarbon group, said C₁-C₃₀The saturated or unsaturated hydrocarbon radicals are optionally substituted by substituents, preferably chosen from halogen, C₁-C₁₀Alkoxy, one or more of the groups containing oxygen, nitrogen, boron, sulfur, phosphorus, silicon, germanium and tin atoms, R₁-R₄Optionally forming a ring with each other.

According to a preferred embodiment of the invention, in formula I, R¹-R¹⁰Each independently selected from H, halogen, C₁-C₂₄Saturated or unsaturated hydrocarbon groups and C₁-C₂₄Saturated or unsaturated hydrocarbyloxy groups.

According to a preferred embodiment of the invention, in formula I, R¹-R¹⁰Each independently selected from H, C₁-C₁₀Alkyl and C₁-C₁₀Alkoxy, preferably selected from H, C₁-C₆Alkyl and C₁-C₆An alkoxy group; for example, R¹-R¹⁰Each independently selected from H,Methyl, ethyl, n-propyl, isopropyl, butyl, pentyl, methoxy, ethoxy and propoxy; further preferably, R¹-R⁶Each independently selected from H and C₁-C₆Alkyl radical, R⁷-R¹⁰Is H.

According to a preferred embodiment of the invention, in formula I, R₁-R₄Each independently selected from H and C₁-C₂₀Saturated or unsaturated hydrocarbon radicals, R₁-R₄Optionally forming a ring with each other.

According to a preferred embodiment of the invention, in formula I, R₁-R₄Each independently selected from H or C₁-C₆Alkyl, preferably R₁And R₄Bonded to form a ring.

According to a preferred embodiment of the invention, the diamine ligand has the structure shown in formula II:

R¹-R¹⁰have the same definitions as in formula I.

In some embodiments of the invention, the diamine ligand represented by formula II may be selected from one or more of the following ligands:

ligand 1: r¹＝R³＝R⁴＝R⁶＝iPr，R²＝R⁵＝R⁷＝R⁸＝R⁹＝R¹⁰＝H；

Ligand 2: r¹＝R³＝R⁴＝R⁶＝Me，R²＝R⁵＝R⁷＝R⁸＝R⁹＝R¹⁰＝H；

Ligand 3: r¹＝R²＝R³＝R⁴＝R⁵＝R⁶＝Me，R⁷＝R⁸＝R⁹＝R¹⁰＝H；

Ligand 4: r¹＝R³＝R⁴＝R⁶＝Et，R²＝R⁵＝R⁷＝R⁸＝R⁹＝R¹⁰＝H；

Ligand 5: r¹＝R²＝R³＝R⁴＝R⁵＝R⁶＝Et，R⁷＝R⁸＝R⁹＝R¹⁰＝H；

Ligand 6: r¹＝R²＝R³＝R⁴＝R⁵＝R⁶＝iPr，R⁷＝R⁸＝R⁹＝R¹⁰＝H。

According to another aspect of the present invention, there is provided a process for preparing the ligand, comprising contacting a diimine compound of formula III with lithium aluminum hydride to obtain a ligand of formula I,

in the formula III, R¹-R¹⁰And R₁-R₄Have the same definitions as in formula I.

According to a preferred embodiment of the invention, the molar ratio of lithium aluminium hydride to the diimine compound of formula III is from 2.0 to 6.0:1, preferably from 2.0 to 4.0: 1.

According to a preferred embodiment of the present invention, the conditions for the contact reaction of the diimine compound represented by formula III and lithium aluminum hydride include: the temperature is 20-120 ℃, preferably 40-80 ℃; and/or for a period of time of from 2 hours to 24 hours, preferably from 4 hours to 12 hours.

According to a preferred embodiment of the invention, when the ligand of formula I has the structure of formula II, the diimine compound of formula III has the structure of formula IV,

in the formula IV, R¹-R¹⁰The same definition as in formula II.

According to yet another aspect of the present invention, there is provided a diamine complex having a structure represented by formula v:

in formula V, R¹-R¹⁰And R₁-R₄Have the same definitions as in formula I; m is a group VIII metal, preferably nickel; x, which are identical or different, are chosen from halogen, saturated or unsaturated hydrocarbon radicals and saturated or unsaturated hydrocarbonoxy radicals, preferably halogen and C₁-C₁₀An alkyl group; n is an integer satisfying the valence of M.

According to a preferred embodiment of the invention, X is halogen, preferably bromine or chlorine.

According to a preferred embodiment of the invention, the diamine complex has the structure shown in formula VI:

in formula VI, M, X, n and R¹-R¹⁰Have the same definitions as in formula V.

The invention also provides a preparation method of the complex, which comprises the step of carrying out coordination reaction on the diamine ligand and MXn or MXn derivatives to obtain the diamine complex.

In some embodiments of the invention, MXn comprises nickel halides, such as nickel bromide and nickel chloride, and derivatives of MXn comprise 1, 2-dimethoxyethane nickel halides, such as 1, 2-dimethoxyethane nickel bromide and 1, 2-dimethoxyethane nickel chloride.

According to still another aspect of the present invention, there is provided a catalyst for olefin polymerization, comprising the above diamine complex as a main catalyst; optionally, the catalyst further comprises a cocatalyst. The cocatalyst is selected from an organoaluminum compound and/or an organoboron compound. According to a preferred embodiment of the present invention, the cocatalyst is selected from one or more of alkylaluminoxanes, alkylaluminums, alkylaluminium halides, arylboronates and borates, more preferably from one or more of trimethylaluminium, triethylaluminium, triisobutylaluminium, tri-N-butylaluminium, tri-N-hexylaluminium, tri-N-pentylaluminium, tri-N-octylaluminium, diethylaluminium chloride, ethylaluminium dichloride, tris (pentafluorophenyl) boron, N-dimethylanilinium tetrakis (pentafluorophenyl) borate and triphenylmethyl tetrakis (pentafluorophenyl) borate.

According to a preferred embodiment of the present invention, when the cocatalyst is an organoaluminum compound, the molar ratio of the metal aluminum in the cocatalyst and the metal in the procatalyst is (200-: 1. when the cocatalyst is an organoboron compound, the molar ratio of boron in the cocatalyst to M in the procatalyst is (0.1-1000):1, for example, 0.1:1, 0.2:1, 0.5:1, 1:1, 2:1, 3:1, 5:1, 8:1, 10:1, 20:1, 50:1, 100:1, 200:1, 300:1, 500:1, 700:1, 800:1, 1000:1 and any value therebetween, preferably (0.1-500): 1.

According to a further aspect of the present invention there is provided a process for the polymerisation of olefins comprising subjecting an olefin, preferably selected from C, to a polymerisation reaction in the presence of a catalyst as described above₂-C₁₆The alpha-olefin is preferably selected from one or more of ethylene, propylene, butene, pentene, hexene, heptene and octene.

According to a preferred embodiment of the invention, the polymerization conditions comprise: the temperature is-78-200 ℃, preferably-20-150 ℃; and/or the pressure is 0.01 to 10.0MPa, preferably 0.01 to 3.0 MPa.

According to a preferred embodiment of the invention, the polymerization is carried out in the presence of a solvent, preferably selected from alkanes, aromatic hydrocarbons or halogenated hydrocarbons. Preferably selected from one or more of hexane, pentane, heptane, benzene, toluene, dichloromethane, chloroform, dichloroethane, most preferably selected from one or more of hexane, toluene, heptane.

The invention provides a novel ligand, and a complex formed by the ligand is used as a main catalyst for olefin polymerization reaction, has good capability of catalyzing the polymerization of ethylene and high alpha-olefin, has high copolymerization activity, and can obtain a polymer with narrow molecular weight distribution.

Detailed Description

The present invention will be described in detail with reference to examples, but the present invention is not limited to the examples.

The analytical characterization instrument used in the present invention was as follows:

nuclear magnetic resonance apparatus: bruker DMX 300(300MHz), Tetramethylsilicon (TMS) as an internal standard.

Molecular weight and molecular weight distribution PDI (PDI ═ Mw/Mn) of the polymer: measured at 150 ℃ using PL-GPC220 in trichlorobenzene (standard: PS, flow rate: 1.0mL/min, column: 3 XPlgel 10um M1 XED-B300X 7.5 nm).

For the purpose of conciseness and clarity in the examples, the ligands and complexes are illustrated below:

a1 is an alpha-diimine compound of formula IV, wherein R is¹＝R²＝R³＝R⁴＝R⁵＝R⁶＝Me，R⁷＝R⁸＝R⁹＝R¹⁰＝H；

A2 is an alpha-diimine compound of formula IV, wherein R is¹＝R³＝R⁴＝R⁶＝iPr，R²＝R⁵＝R⁷＝R⁸＝R⁹＝R¹⁰＝H；

A3 is an alpha-diimine compound of formula IV, wherein R is¹＝R³＝R⁴＝R⁶＝CH₃，R²＝R⁵＝R⁷＝R⁸＝R⁹＝R¹⁰＝H；

Ligand L1 is a diamine compound represented by formula II, wherein R is¹＝R²＝R³＝R⁴＝R⁵＝R⁶＝Me，R⁷＝R⁸＝R⁹＝R¹⁰＝H；

Ligand L2 is a diamine of formula IIA base compound wherein R¹＝R³＝R⁴＝R⁶＝iPr，R²＝R⁵＝R⁷＝R⁸＝R⁹＝R¹⁰＝H；

Ligand L3 is a diamine compound represented by formula II, wherein R is¹＝R³＝R⁴＝R⁶＝CH₃，R²＝R⁵＝6⁷＝R⁸＝R⁹＝R¹⁰＝H；

The complex 1 is a complex shown as a formula VI, wherein R¹＝R²＝R³＝R⁴＝R⁵＝R⁶＝Me，R⁷＝R⁸＝R⁹＝R¹⁰＝H，M＝Ni，X＝Br；

The complex 2 is a complex shown as a formula VI, wherein R¹＝R³＝R⁴＝R⁶＝iPr，R²＝R⁵＝R⁷＝R⁸＝R⁹＝R¹⁰＝H，M＝Ni，X＝Br；

The complex 3 is a complex shown as a formula VI, wherein R¹＝R³＝R⁴＝R⁶＝iPr，R²＝R⁵＝R⁷＝R⁸＝R⁹＝R¹⁰＝H，M＝Ni，X＝Cl；

The complex 4 is a complex shown as a formula VI, wherein R¹＝R³＝R⁴＝R⁶＝CH₃，R²＝R⁵＝R⁷＝R⁸＝R⁹＝R¹⁰＝H，M＝Ni，X＝Br；

The structures in complex A and complex B used in the comparative examples are as follows:

example 1

1) Preparation of the ligand:

alpha-diimine compound A13.20g (8mmol), and then 50 parts of the mixture were added in this orderml of tetrahydrofuran, 0.61g (16mmol) of lithium aluminum hydride, was stirred at 60 ℃ for 6 hours. After cooling, the reaction was quenched with aqueous sodium hydroxide, and the organic phase was extracted with ethyl acetate, dried, filtered and recrystallized to yield colorless crystals as ligand L1 in 78% yield.¹H-NMR(CDCl₃，300MHz)6.71(s,4H,Ar-H),2.82(s,2H,NH),2.42(t,1H),2.32(d,1H),2.26(s,6H,CH₃),2.12(s,12H),1.56(m,4H,CH₂),1.15(m,1H),1.08(s,3H,CH₃),0.92(s,6H,CH₃).

2) Preparation of Complex 1: 10ml of (DME) NiBr₂(277mg,0.9mmol) of a dichloromethane solution was added dropwise to a solution of 10ml of ligand L1(364mg,0.9mmol) in dichloromethane, and stirred at room temperature for 6 hours to precipitate, which was washed with ether by filtration and dried to give a red powdery solid in 86% yield. Elemental analysis (C)₂₈H₄₀Br₂N₂Ni): c, 53.97; h, 6.47; n, 4.50; experimental values (%): c, 54.17; h, 6.53; n, 4.74.

3)10atm ethylene polymerization: continuously drying a 1L stainless steel polymerization kettle equipped with mechanical stirring at 130 deg.C for 6hrs, vacuumizing while it is hot, and adding N₂Replace qi for 3 times. 6.2mg (10. mu. mol) of complex 1 are added and then evacuated and replaced 3 times with ethylene. 500ml of hexane was added, and 6.5ml of Methylaluminoxane (MAO) (1.53mol/l toluene solution) was added thereto to make Al/Ni 1000. The reaction was vigorously stirred at 20 ℃ for 30min while maintaining an ethylene pressure of 10 atm. And neutralizing with 5% ethanol solution acidified by hydrochloric acid to obtain polyethylene.

Example 2

10atm ethylene polymerization: continuously drying a 1L stainless steel polymerization kettle equipped with mechanical stirring at 130 deg.C for 6hrs, vacuumizing while it is hot, and adding N₂Replace qi for 3 times. 6.2mg (10. mu. mol) of complex 1 are added and then evacuated and replaced 3 times with ethylene. 500ml of hexane was added, and 6.5ml of Methylaluminoxane (MAO) (1.53mol/l toluene solution) was added thereto to make Al/Ni 1000. The reaction was vigorously stirred at 20 ℃ for 10min while maintaining an ethylene pressure of 10 atm. And neutralizing with 5% ethanol solution acidified by hydrochloric acid to obtain polyethylene.

Example 3

10atm ethylene polymerization: will be equipped with mechanical stirring 1L stainless steelThe polymerization vessel was dried continuously at 130 ℃ for 6hrs, evacuated while hot and charged with N₂Replace qi for 3 times. 6.2mg (10. mu. mol) of complex 1 are added and then evacuated and replaced 3 times with ethylene. 500ml of hexane was added, and 6.5ml of Methylaluminoxane (MAO) (1.53mol/l toluene solution) was added thereto to make Al/Ni 1000. The reaction was vigorously stirred at 20min with maintaining ethylene pressure of 10atm at 20 ℃. And neutralizing with 5% ethanol solution acidified by hydrochloric acid to obtain polyethylene.

Example 4

10atm ethylene polymerization: continuously drying a 1L stainless steel polymerization kettle equipped with mechanical stirring at 130 deg.C for 6hrs, vacuumizing while it is hot, and adding N₂Replace qi for 3 times. 6.2mg (10. mu. mol) of complex 1 are added and then evacuated and replaced 3 times with ethylene. 500ml of hexane was added, and 6.5ml of Methylaluminoxane (MAO) (1.53mol/l toluene solution) was added thereto to make Al/Ni 1000. The reaction was vigorously stirred at 20 ℃ for 60min while maintaining the ethylene pressure at 10 atm. And neutralizing with 5% ethanol solution acidified by hydrochloric acid to obtain polyethylene.

Example 5

10atm ethylene polymerization: continuously drying a 1L stainless steel polymerization kettle equipped with mechanical stirring at 130 deg.C for 6hrs, vacuumizing while it is hot, and adding N₂Replace qi for 3 times. 6.2mg (10. mu. mol) of complex 1 are added and then evacuated and replaced 3 times with ethylene. 500ml of hexane was added, and 6.5ml of Methylaluminoxane (MAO) (1.53mol/l toluene solution) was added thereto to make Al/Ni 1000. The reaction was vigorously stirred at 60 ℃ for 30min while maintaining an ethylene pressure of 10 atm. And neutralizing with 5% ethanol solution acidified by hydrochloric acid to obtain polyethylene.

Example 6

1) Preparation of the ligand:

after 23.88g (8mmol) of the alpha-diimine compound, 50ml of tetrahydrofuran and 0.61g (16mmol) of lithium aluminum hydride were sequentially added thereto, and the mixture was stirred at 60 ℃ for 6 hours. After cooling, the reaction was quenched with aqueous sodium hydroxide, and the organic phase was extracted with ethyl acetate, dried, filtered and recrystallized to give ligand L2 as colorless crystals in 58% yield.¹HNMR(CDCl₃，300MHz)7.06(d,4H,Ar-H),6.80(t,2H,Ar-H),2.88(m,4H,CH(CH₃)₂),2.72(s,2H,NH),2.42(t,1H),2.32(d,1H),1.58(m,4H,CH₂),1.18(d,24H),1.13(m,1H,),1.08(s,3H,CH₃),0.92(s,6H,CH₃).

2) Preparation of Complex 2: 10ml of (DME) NiBr₂(277mg,0.9mmol) of a dichloromethane solution was added dropwise to a solution of 10ml of ligand L2(440mg,0.9mmol) in dichloromethane, and stirred at room temperature for 6 hours to precipitate, which was washed with ether for filtration and dried to give a red powdery solid in a yield of 78%. Elemental analysis (C)₃₄H₅₂Br₂N₂Ni): c, 57.74; h, 7.41; n, 3.96; experimental values (%): c, 57.65; h, 7.68; and N, 3.62.

3)10atm ethylene polymerization: continuously drying a 1L stainless steel polymerization kettle equipped with mechanical stirring at 130 deg.C for 6hrs, vacuumizing while it is hot, and adding N₂Replace qi for 3 times. 7.1mg (10. mu. mol) of complex 2 are added and then a further vacuum is applied and the mixture is replaced 3 times with ethylene. 500ml of hexane was added, and 6.5ml of Methylaluminoxane (MAO) (1.53mol/l toluene solution) was added thereto to make Al/Ni 1000. The reaction was vigorously stirred at 20 ℃ for 30min while maintaining an ethylene pressure of 10 atm. And neutralizing with 5% ethanol solution acidified by hydrochloric acid to obtain polyethylene.

Example 7

10atm ethylene polymerization: continuously drying a 1L stainless steel polymerization kettle equipped with mechanical stirring at 130 deg.C for 6hrs, vacuumizing while it is hot, and adding N₂Replace qi for 3 times. 7.1mg (10. mu. mol) of complex 2 are added and then a further vacuum is applied and the mixture is replaced 3 times with ethylene. 500ml of hexane was added, and 6.5ml of Methylaluminoxane (MAO) (1.53mol/l toluene solution) was added thereto to make Al/Ni 1000. The reaction was vigorously stirred at 60 ℃ for 30min while maintaining an ethylene pressure of 10 atm. And neutralizing with 5% ethanol solution acidified by hydrochloric acid to obtain polyethylene.

Example 8

Preparation of Complex 3: 10ml of (DME) NiCl₂(198mg,0.9mmol) of dichloromethane solution was added dropwise to a solution of 10ml ligand L2(440mg,0.9mmol) in dichloromethane, stirred at room temperature for 6 hours, the precipitate precipitated, filtered, washed with ether and dried to give a red powder solid in 78% yield. Elemental analysis (C)₃₄H₅₂Cl₂N₂Ni): c, 66.04; h, 8.48; n, 4.53; experimental values (%): c, 65.85; h, 8.68; n, 4.62.

3)10atm ethylene polymerization: continuously drying a 1L stainless steel polymerization kettle equipped with mechanical stirring at 130 deg.C for 6hrs, vacuumizing while it is hot, and adding N₂Replace qi for 3 times. 6.2mg (10. mu. mol) of complex 3 are added and then a further vacuum is applied and the mixture is replaced 3 times with ethylene. 500ml of hexane was added, and 6.5ml of Methylaluminoxane (MAO) (1.53mol/l toluene solution) was added thereto to make Al/Ni 1000. The reaction was vigorously stirred at 20 ℃ for 30min while maintaining an ethylene pressure of 10 atm. And neutralizing with 5% ethanol solution acidified by hydrochloric acid to obtain polyethylene.

Example 9

1) Synthesis of alpha-diamine ligand L3

2.98g (8mmol) of the alpha-diimine compound A3 was placed in a 100ml three-necked flask equipped with a reflux condenser, and then 50ml of tetrahydrofuran and 0.61g (16mmol) of lithium aluminum hydride were sequentially added thereto, followed by stirring at 60 ℃ for 6 hours. After cooling, the reaction was quenched with aqueous sodium hydroxide, and the organic phase was extracted with ethyl acetate, dried, filtered and recrystallized to give ligand L3 as colorless crystals in 80% yield.¹HNMR(CDCl₃，300MHz)6.88(d,4H,Ar-H),6.80(t,2H,Ar-H),2.82(s,2H,NH),2.42(t,1H),2.32(d,1H),2.13(s,12H,CH₃),1.57(m,4H,CH₂),1.14(m,1H,),1.09(s,3H,CH₃),0.93(s,6H,CH₃).

2) Preparation of Complex 4: 10ml of (DME) NiBr₂(277mg,0.9mmol) of a dichloromethane solution was added dropwise to a solution of 10ml of ligand L3(339mg,0.9mmol) in dichloromethane, and stirred at room temperature for 6 hours to precipitate, which was washed with ether by filtration and dried to give a red powdery solid in 88% yield. Elemental analysis (C)₂₆H₃₆Br₂N₂Ni): c, 52.48; h, 6.10; n, 4.71; experimental values (%): c, 52.56; h, 6.33; n, 4.56.

3)10atm ethylene polymerization: continuously drying a 1L stainless steel polymerization kettle equipped with mechanical stirring at 130 deg.C for 6hrs, vacuumizing while it is hot, and adding N₂Replace qi for 3 times. 6.0mg (10. mu. mol) of complex 4 are added and then a further vacuum is applied and the mixture is replaced 3 times with ethylene. 500ml of hexane was added, and 6.5ml of Methylaluminoxane (MAO) (1.53mol/l toluene solution) was added thereto to make Al/Ni 1000. Maintaining ethylene pressure of 10atm at 20 deg.C, stirring vigorouslyIt should be 30 min. And neutralizing with 5% ethanol solution acidified by hydrochloric acid to obtain polyethylene.

Example 10

10atm ethylene polymerization: continuously drying a 1L stainless steel polymerization kettle equipped with mechanical stirring at 130 deg.C for 6hrs, vacuumizing while it is hot, and adding N₂Replace qi for 3 times. 6.0mg (10. mu. mol) of complex 4 are added and then a further vacuum is applied and the mixture is replaced 3 times with ethylene. 500ml of hexane was added, and 6.5ml of Methylaluminoxane (MAO) (1.53mol/l toluene solution) was added thereto to make Al/Ni 1000. The reaction was vigorously stirred at 40 ℃ for 30min while maintaining an ethylene pressure of 10 atm. And neutralizing with 5% ethanol solution acidified by hydrochloric acid to obtain polyethylene.

Example 11

10atm ethylene polymerization: continuously drying a 1L stainless steel polymerization kettle equipped with mechanical stirring at 130 deg.C for 6hrs, vacuumizing while it is hot, and adding N₂Replace qi for 3 times. 6.0mg (10. mu. mol) of complex 4 are added and then a further vacuum is applied and the mixture is replaced 3 times with ethylene. 500ml of hexane was added, and 6.5ml of Methylaluminoxane (MAO) (1.53mol/l toluene solution) was added thereto to make Al/Ni 1000. The reaction was vigorously stirred at 60 ℃ for 30min while maintaining an ethylene pressure of 10 atm. And neutralizing with 5% ethanol solution acidified by hydrochloric acid to obtain polyethylene.

Example 12

10atm ethylene polymerization: continuously drying a 1L stainless steel polymerization kettle equipped with mechanical stirring at 130 deg.C for 6hrs, vacuumizing while it is hot, and adding N₂Replace qi for 3 times. 6.0mg (10. mu. mol) of complex 4 are added and then a further vacuum is applied and the mixture is replaced 3 times with ethylene. 500ml of hexane was poured in, and 1.0ml of diethylaluminum monochloride (2.0mol/l in toluene) was added thereto so that Al/Ni became 200. The reaction was vigorously stirred at 60 ℃ for 30min while maintaining an ethylene pressure of 10 atm. And neutralizing with 5% ethanol solution acidified by hydrochloric acid to obtain polyethylene.

Example 13

10atm ethylene polymerization: continuously drying a 1L stainless steel polymerization kettle equipped with mechanical stirring at 130 deg.C for 6hrs, vacuumizing while it is hot, and adding N₂Replace qi for 3 times. 6.0mg (10. mu. mol) of complex 4 are added and then a further vacuum is applied and the mixture is replaced 3 times with ethylene. 500ml of hexane were injected, 6.5ml of Methylaluminoxane (MAO) (1.53mol/l in toluene) were added,let Al/Ni be 1000. The reaction was vigorously stirred at 20 ℃ for 10min while maintaining an ethylene pressure of 10 atm. And neutralizing with 5% ethanol solution acidified by hydrochloric acid to obtain polyethylene.

Example 14

10atm ethylene polymerization: continuously drying a 1L stainless steel polymerization kettle equipped with mechanical stirring at 130 deg.C for 6hrs, vacuumizing while it is hot, and adding N₂Replace qi for 3 times. 6.0mg (10. mu. mol) of complex 4 are added and then a further vacuum is applied and the mixture is replaced 3 times with ethylene. 500ml of hexane was added, and 6.5ml of Methylaluminoxane (MAO) (1.53mol/l toluene solution) was added thereto to make Al/Ni 1000. The reaction was vigorously stirred at 20min with maintaining ethylene pressure of 10atm at 20 ℃. And neutralizing with 5% ethanol solution acidified by hydrochloric acid to obtain polyethylene.

Example 15

10atm ethylene polymerization: continuously drying a 1L stainless steel polymerization kettle equipped with mechanical stirring at 130 deg.C for 6hrs, vacuumizing while it is hot, and adding N₂Replace qi for 3 times. 6.0mg (10. mu. mol) of complex 4 are added and then a further vacuum is applied and the mixture is replaced 3 times with ethylene. 500ml of hexane was added, and 6.5ml of Methylaluminoxane (MAO) (1.53mol/l toluene solution) was added thereto to make Al/Ni 1000. The reaction was vigorously stirred at 20 ℃ for 60min while maintaining the ethylene pressure at 10 atm. And neutralizing with 5% ethanol solution acidified by hydrochloric acid to obtain polyethylene.

Example 16

10atm ethylene polymerization: continuously drying a 1L stainless steel polymerization kettle equipped with mechanical stirring at 130 deg.C for 6hrs, vacuumizing while it is hot, and adding N₂Replace qi for 3 times. 6.0mg (10. mu. mol) of complex 4 are added and then a further vacuum is applied and the mixture is replaced 3 times with ethylene. 500ml of hexane was added, and 6.5ml of Methylaluminoxane (MAO) (1.53mol/l toluene solution) was added thereto to make Al/Ni 1000, 10ml of 1-hexene. The reaction was vigorously stirred at 20 ℃ for 30min while maintaining an ethylene pressure of 10 atm. And neutralizing with 5% ethanol solution acidified by hydrochloric acid to obtain polyethylene.

Comparative example 1

10atm ethylene: continuously drying a 1L stainless steel polymerization kettle equipped with mechanical stirring at 130 deg.C for 6hrs, vacuumizing while it is hot, and adding N₂Replace qi for 3 times. 7.2mg (10. mu. mol) of comparative catalyst A, whose structure is given in the following formula (I), are added and then extractedVacuum and replace 3 times with ethylene. 500ml of hexane was added, and 6.5ml of Methylaluminoxane (MAO) (1.53mol/l toluene solution) was added thereto to make Al/Ni 1000, 10ml of hexene. The reaction was vigorously stirred at 60 ℃ for 30min while maintaining an ethylene pressure of 10 atm. And neutralizing with 5% ethanol solution acidified by hydrochloric acid to obtain polyethylene.

Comparative example 2

10atm ethylene: continuously drying a 1L stainless steel polymerization kettle equipped with mechanical stirring at 130 deg.C for 6hrs, vacuumizing while it is hot, and adding N₂Replace qi for 3 times. 5.1mg (10. mu. mol) of comparative catalyst B, whose structure is given below in formula (II), are added and then a vacuum is applied and the reaction mixture is replaced 3 times with ethylene. 500ml of hexane was added, 6.5ml of Methylaluminoxane (MAO) (1.53mol/l toluene solution) was added thereto to make Al/Ni 1000, and the mixture was stirred vigorously at 60 ℃ under an ethylene pressure of 10atm for 30 min. And neutralizing with 5% ethanol solution acidified by hydrochloric acid to obtain polyethylene.

Comparative example 3

10atm ethylene: continuously drying a 1L stainless steel polymerization kettle equipped with mechanical stirring at 130 deg.C for 6hrs, vacuumizing while it is hot, and adding N₂Replace qi for 3 times. 7.2mg (10. mu. mol) of comparative catalyst A, whose structure is given in the following formula (I), are added and then evacuated and replaced 3 times with ethylene. 500ml of hexane was added, and 6.5ml of Methylaluminoxane (MAO) (1.53mol/l toluene solution) was added thereto to make Al/Ni 1000, 10ml of hexene. The reaction was vigorously stirred at 20 ℃ for 30min while maintaining an ethylene pressure of 10 atm. And neutralizing with 5% ethanol solution acidified by hydrochloric acid to obtain polyethylene.

TABLE 1

As can be seen from Table 1, when the metal complex of the present invention is used as a procatalyst, the polymerization activity under high temperature polymerization conditions is much higher, the molecular weight of the obtained polymer is significantly higher than that of the comparative example, and the molecular weight distribution is narrower, compared to the complex of the comparative example.

It should be noted that the above-mentioned embodiments are only for explaining the present invention, and do not constitute any limitation to the present invention. The present invention has been described with reference to exemplary embodiments, but the words which have been used herein are words of description and illustration, rather than words of limitation. The invention can be modified, as prescribed, within the scope of the claims and without departing from the scope and spirit of the invention. Although the invention has been described herein with reference to particular means, materials and embodiments, the invention is not intended to be limited to the particulars disclosed herein, but rather extends to all other methods and applications having the same functionality.

Claims (18)

1. A diamine ligand having the structure shown in formula ii:

the diamine ligand shown in the formula II is selected from one or more of the following ligands:

ligand 1: r¹＝R³＝R⁴＝R⁶＝iPr，R²＝R⁵＝R⁷＝R⁸＝R⁹＝R¹⁰＝H；

Ligand 2: r¹＝R³＝R⁴＝R⁶＝Me，R²＝R⁵＝R⁷＝R⁸＝R⁹＝R¹⁰＝H；

Ligand 3: r¹＝R²＝R³＝R⁴＝R⁵＝R⁶＝Me，R⁷＝R⁸＝R⁹＝R¹⁰ ₂＝H；

Ligand 4: r¹＝R³＝R⁴＝R⁶＝Et，R²＝R⁵＝R⁷＝R⁸＝R⁹＝R¹⁰＝H；

Ligand 5: r¹＝R²＝R³＝R⁴＝R⁵＝R⁶＝Et，R⁷＝R⁸＝R⁹＝R¹⁰＝H；

Ligand 6: r¹＝R²＝R³＝R⁴＝R⁵＝R⁶＝iPr，R⁷＝R⁸＝R⁹＝R¹⁰＝H。

2. A process for preparing the ligand of claim 1, comprising contacting a diimine compound of formula IV with lithium aluminum hydride to obtain a ligand of formula II,

in formula IV, the diimine compound is selected from one or more of the following ligands:

diimine compound 1: r¹＝R³＝R⁴＝R⁶＝iPr，R²＝R⁵＝R⁷＝R⁸＝R⁹＝R¹⁰＝H；

Diimine compound 2: r¹＝R³＝R⁴＝R⁶＝Me，R²＝R⁵＝R⁷＝R⁸＝R⁹＝R¹⁰＝H；

Diimine compound 3: r¹＝R²＝R³＝R⁴＝R⁵＝R⁶＝Me，R⁷＝R⁸＝R⁹＝R¹⁰ ₂＝H；

Diimine compound 4: r¹＝R³＝R⁴＝R⁶＝Et，R²＝R⁵＝R⁷＝R⁸＝R⁹＝R¹⁰＝H；

Diimine compound 5: r¹＝R²＝R³＝R⁴＝R⁵＝R⁶＝Et，R⁷＝R⁸＝R⁹＝R¹⁰＝H；

Diimine compound 6: r¹＝R²＝R³＝R⁴＝R⁵＝R⁶＝iPr，R⁷＝R⁸＝R⁹＝R¹⁰＝H。

3. The method of claim 2, wherein the molar ratio of lithium aluminum hydride to the diimine compound of formula IV is 2.0-6.0: 1.

4. The method of claim 2, wherein the molar ratio of lithium aluminum hydride to the diimine compound of formula IV is 2.0-4.0: 1.

5. The method of claim 2, wherein the conditions of the contact reaction comprise: the temperature is 20-120 ℃.

6. The method of claim 2, wherein the conditions of the contact reaction comprise: the temperature is 40-80 ℃.

7. The method of claim 2, wherein the conditions of the contact reaction comprise: the time is 2 hours to 24 hours.

8. The method of claim 2, wherein the conditions of the contact reaction comprise: the time is 4 hours to 12 hours.

9. A diamine complex having a structure according to formula vi:

in formula VI, M is a group VIII metal; x, which are identical or different, are chosen from halogen, saturated or unsaturated hydrocarbon radicals and saturated or unsaturated hydrocarbonoxy radicals; n is an integer satisfying the valence of M;

the diamine complex shown in the formula VI is selected from one or more of the following complexes:

diamine complex 1: r¹＝R³＝R⁴＝R⁶＝iPr，R²＝R⁵＝R⁷＝R⁸＝R⁹＝R¹⁰＝H；

Diamine complex 2: r¹＝R³＝R⁴＝R⁶＝Me，R²＝R⁵＝R⁷＝R⁸＝R⁹＝R¹⁰＝H；

Diamine complex 3: r¹＝R²＝R³＝R⁴＝R⁵＝R⁶＝Me，R⁷＝R⁸＝R⁹＝R¹⁰ ₂＝H；

Diamine complex 4: r¹＝R³＝R⁴＝R⁶＝Et，R²＝R⁵＝R⁷＝R⁸＝R⁹＝R¹⁰＝H；

Diamine complex 5: r¹＝R²＝R³＝R⁴＝R⁵＝R⁶＝Et，R⁷＝R⁸＝R⁹＝R¹⁰＝H；

Diamine complex 6: r¹＝R²＝R³＝R⁴＝R⁵＝R⁶＝iPr，R⁷＝R⁸＝R⁹＝R¹⁰＝H。

10. The complex of claim 9, wherein M is nickel.

11. The complex of claim 9, wherein X is halogen and C1-10 alkyl.

12. A catalyst for olefin polymerization comprising the complex of any one of claims 9 to 11 as a procatalyst; optionally, the catalyst further comprises a cocatalyst selected from an organoaluminum compound and/or an organoboron compound.

13. The catalyst of claim 12 wherein the cocatalyst is selected from one or more of alkylaluminoxanes, alkylaluminums, alkylaluminium halides, arylborohydrides and borates.

14. The catalyst of claim 12 wherein the cocatalyst is selected from one or more of trimethylaluminum, triethylaluminum, triisobutylaluminum, tri-N-butylaluminum, tri-N-hexylaluminum, tri-N-pentylaluminum, tri-N-octylaluminum, diethylaluminum chloride, ethylaluminum dichloride, methylalumoxane, modified methylalumoxane, tris (pentafluorophenyl) boron, N-dimethylanilinium tetrakis (pentafluorophenyl) borate, and triphenylmethyl tetrakis (pentafluorophenyl) borate.

15. The catalyst as claimed in any one of claims 12 to 14, wherein when the cocatalyst is an organoaluminum compound, the molar ratio of the metallic aluminum in the cocatalyst to the M in the main catalyst is 200-; when the cocatalyst is an organic boron compound, the molar ratio of boron in the cocatalyst to M in the main catalyst is 0.1-1000: 1.

16. The catalyst as claimed in claim 15, wherein when the cocatalyst is an organoaluminum compound, the molar ratio of the metallic aluminum in the cocatalyst to the M in the main catalyst is 200-5000: 1.

17. A process for the polymerization of olefins comprising subjecting an olefin to a polymerization reaction in the presence of the catalyst of any one of claims 12-16.

18. The catalyst of claim 17 wherein the olefin is C₂-C₁₆Alpha-olefin.