CN110746468A - Star-shaped pyridine imine nickel-based catalyst and preparation method and application thereof - Google Patents

Star-shaped pyridine imine nickel-based catalyst and preparation method and application thereof Download PDF

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CN110746468A
CN110746468A CN201910995468.1A CN201910995468A CN110746468A CN 110746468 A CN110746468 A CN 110746468A CN 201910995468 A CN201910995468 A CN 201910995468A CN 110746468 A CN110746468 A CN 110746468A
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nickel
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张娜
王俊
李翠勤
毛国梁
陈丽铎
王玲
翟岩亮
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Northeast Petroleum University
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    • B01J31/16Catalysts comprising hydrides, coordination complexes or organic compounds containing coordination complexes
    • B01J31/18Catalysts comprising hydrides, coordination complexes or organic compounds containing coordination complexes containing nitrogen, phosphorus, arsenic or antimony as complexing atoms, e.g. in pyridine ligands, or in resonance therewith, e.g. in isocyanide ligands C=N-R or as complexed central atoms
    • B01J31/1805Catalysts comprising hydrides, coordination complexes or organic compounds containing coordination complexes containing nitrogen, phosphorus, arsenic or antimony as complexing atoms, e.g. in pyridine ligands, or in resonance therewith, e.g. in isocyanide ligands C=N-R or as complexed central atoms the ligands containing nitrogen
    • B01J31/181Cyclic ligands, including e.g. non-condensed polycyclic ligands, comprising at least one complexing nitrogen atom as ring member, e.g. pyridine
    • B01J31/1815Cyclic ligands, including e.g. non-condensed polycyclic ligands, comprising at least one complexing nitrogen atom as ring member, e.g. pyridine with more than one complexing nitrogen atom, e.g. bipyridyl, 2-aminopyridine
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    • C07C2/04Preparation of hydrocarbons from hydrocarbons containing a smaller number of carbon atoms by addition between unsaturated hydrocarbons by oligomerisation of well-defined unsaturated hydrocarbons without ring formation
    • C07C2/06Preparation of hydrocarbons from hydrocarbons containing a smaller number of carbon atoms by addition between unsaturated hydrocarbons by oligomerisation of well-defined unsaturated hydrocarbons without ring formation of alkenes, i.e. acyclic hydrocarbons having only one carbon-to-carbon double bond
    • C07C2/08Catalytic processes
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    • C07C2/32Catalytic processes with hydrides or organic compounds as complexes, e.g. acetyl-acetonates
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    • B01J2231/00Catalytic reactions performed with catalysts classified in B01J31/00
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    • B01J2531/02Compositional aspects of complexes used, e.g. polynuclearity
    • B01J2531/0238Complexes comprising multidentate ligands, i.e. more than 2 ionic or coordinative bonds from the central metal to the ligand, the latter having at least two donor atoms, e.g. N, O, S, P
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    • B01J2531/80Complexes comprising metals of Group VIII as the central metal
    • B01J2531/84Metals of the iron group
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Abstract

The application relates to the technical field of organic synthesis and petrochemical industry, in particular to a star-shaped pyridine imine nickel catalyst, and a preparation method and application thereof. The structural formula (I) of the star-shaped pyridine imine nickel catalyst is as follows:
Figure DDA0002239584270000011
wherein R is selected from H, Br and CH3One kind of (1). The star-shaped pyridine imine nickel catalyst has the characteristics of both a homogeneous catalyst and a heterogeneous catalyst, has good catalytic activity and high-carbon olefin selectivity, and is easy to separate and convenient to recycle.

Description

Star-shaped pyridine imine nickel-based catalyst and preparation method and application thereof
Technical Field
The application relates to the technical field of organic synthesis and petrochemical industry, in particular to a star-shaped pyridine imine nickel catalyst, and a preparation method and application thereof.
Background
α -olefin is usually used as an important comonomer to produce high-performance polyolefin products due to good tear resistance, and the high-performance polyolefin products have good tensile breaking stress, tensile yield stress, tear strength and other properties.
The ethylene polymerization catalyst is a key element for synthesizing linear α -olefin by using an ethylene polymerization method, and common catalytic systems comprise transition metal catalysts such as Zr series, Ni series, Ti series, Fe series, Cr series and the like.
Disclosure of Invention
The application aims to provide a star-shaped pyridine imine nickel catalyst, and a preparation method and application thereof, so as to solve the problems that the existing ethylene polymerization catalyst is difficult to have high catalytic activity and good separation effect at the same time.
In a first aspect, the present application provides a star-shaped pyridine imine nickel-based catalyst, wherein the structural formula (I) of the star-shaped pyridine imine nickel-based catalyst is:
wherein R is selected from H, Br and CH3One kind of (1).
In a second aspect, the present application provides a preparation method of a star-shaped pyridine imine nickel-based catalyst, including the following steps:
s1, adding pyridine-2 formaldehyde or a pyridine-2 formaldehyde substituent and a water absorbent into a first organic solvent to form a reaction system, cooling the reaction system to-5 ℃ under the condition of inert gas, adding an organic solution of a compound with a structural formula (II), reacting for 15-60min, stirring and heating to 20-40 ℃, continuously stirring and reacting for 20-40h, and filtering after reaction to obtain a filtrate;
Figure BDA0002239584250000022
s2, reacting the filtrate with an organic solution of nickel chloride hexahydrate under the condition of inert gas at the temperature of 20-40 ℃ for 20-40 hours under stirring to obtain the star-shaped pyridine imine nickel catalyst, wherein the structural formula (I) of the star-shaped pyridine imine nickel catalyst is as follows:
Figure BDA0002239584250000031
wherein R is selected from H, Br and CH3One kind of (1).
The amount of the first organic solvent, the amount of the organic solution used in the organic solution of the compound of formula (II), and the amount of the organic solution used in the organic solution of nickel chloride hexahydrate are not limited strictly, and those skilled in the art can select and determine the amount of the first organic solvent according to practical situations, for example, the amount of the first organic solvent can be more than the amount of the first organic solvent used in the reaction and the amount of the second organic solvent used in the post-treatment, and will not be described in detail herein.
It is understood that the temperature reduction to-5 to 5 ℃ in said step of S1 includes any value within this range, for example to-5 ℃, -3 ℃, -1 ℃, 0 ℃, 2 ℃, 4 ℃ or 5 ℃; the reaction time of 15-60min includes any point value in the time range, such as 15min, 20min, 30min, 45min, 50min or 60 min; heating to 20-40 deg.C with stirring, including any point in this temperature range, for example, heating to 20 deg.C, 25 deg.C, 30 deg.C, 35 deg.C, or 40 deg.C with stirring; stirring the reaction for 20-40h includes any point within the time range, for example stirring the reaction for 20h, 24h, 30h, or 40 h. In the S2 step, the reaction temperature is 20-40 ℃ including any point in the temperature range, for example, the reaction temperature is 20 ℃, 25 ℃, 30 ℃, 35 ℃ or 40 ℃; the stirring reaction time is 20-40h and includes any point in the time range, such as 20h, 24h, 30h or 40 h.
In addition, pyridine-2-carbaldehyde, substituted pyridine-2-carbaldehyde, a compound of formula (II), and nickel chloride hexahydrate are well known in the art and are commercially available from a variety of sources and will not be described in detail herein.
Further, the step S1 is: adding pyridine-2-formaldehyde or a pyridine-2-formaldehyde substitute and the water absorbent into the first organic solvent at room temperature to form a reaction system, cooling the reaction system to 0 ℃ under the condition of inert gas, adding the organic solution of the compound of the structural formula (II), reacting for 30min, stirring and heating to 25 ℃, continuously stirring and reacting for 24h, and filtering under negative pressure after the reaction to obtain the filtrate; wherein the molar ratio of the compound of the structural formula (II) to the pyridine-2-carbaldehyde or the substituent of the pyridine-2-carbaldehyde is 1:5-1: 6.
Further, the step S2 is: slowly dropwise adding the organic solution of nickel chloride hexahydrate into the filtrate under the condition of inert gas to form a reaction solution, stirring and reacting for 24 hours at 25 ℃, and carrying out post-treatment on the reaction solution after reaction to obtain the star-shaped pyridine imine nickel catalyst; wherein the molar ratio of the compound shown in the structural formula (II) to the nickel chloride hexahydrate is 1:3-1: 4.
Further, in the step S2, the post-processing is: and adding ether into the reaction solution after the reaction to separate out a green solid, filtering and collecting the green solid, washing the green solid with anhydrous ether, and drying the washed green solid to constant weight under a vacuum condition to obtain the star-shaped pyridine imine nickel catalyst.
Further, in the preparation method, the substitute of pyridine-2-carbaldehyde is selected from 6-methyl-2-pyridinecarbaldehyde or 6-bromo-2-pyridinecarbaldehyde, and the water absorbent is selected from anhydrous sodium sulfate, anhydrous magnesium sulfate or anhydrous calcium chloride; the inert gas is selected from nitrogen, helium or argon; the first organic solvent in the step S1 is one or a mixture of two of methanol and ethanol; the solvent used in the organic solution of the compound of the structural formula (II) and the solvent used in the organic solution of the nickel chloride hexahydrate are both selected from one or a mixture of two of methanol and ethanol.
In the right 7-third aspect, the application provides the use of the star-shaped pyridine imine nickel-based catalyst in the preparation of α -olefin by ethylene oligomerization.
In the right 8-fourth aspect, the application provides a method for preparing α -olefin, which is to dissolve the star-shaped pyridine imine nickel-based catalyst in a second organic solvent, add a cocatalyst, and introduce ethylene to react to obtain the α -olefin.
Further, the method comprises the steps of dissolving the star-shaped pyridine imine nickel catalyst in the second organic solvent, adding a cocatalyst, introducing ethylene to 0.1-1.0MPa, keeping the ethylene pressure constant, and stirring and reacting at 10-50 ℃ to obtain α -olefin, wherein the cocatalyst is methylaluminoxane, and the molar ratio of aluminum elements in the methylaluminoxane to nickel elements in the star-shaped pyridine imine nickel catalyst is 300:1-1500: 1.
It is understood that in the method for preparing α -olefin, the constant pressure reaction time is not particularly required, as long as the activity of the catalyst for catalyzing the oligomerization of ethylene and the selectivity of the product can be ensured, for example, the activity can be calculated by the difference between the mass before and after the reaction, the selectivity of the product can be detected by gas chromatography, and the skilled person can select the appropriate reaction time according to the actual situation, and the detailed description is omitted.
Further, in the method, the second organic solvent is one or a mixture of toluene, methylcyclohexane or cyclohexane.
Preferably, the method comprises the steps of dissolving the star-shaped pyridine imine nickel catalyst in toluene, adding methylaluminoxane, introducing ethylene to 1.0MPa, keeping the ethylene pressure constant, and stirring at 10 ℃ for reaction to obtain α -olefin, wherein the molar ratio of aluminum in the methylaluminoxane to nickel in the star-shaped pyridine imine nickel catalyst is 500: 1.
Compared with the prior art, the beneficial effects of this application are as follows:
firstly, the application provides a nickel catalyst with a novel structure, namely a star-shaped pyridine imine nickel catalyst, and the ligand of the catalyst is star-shaped pyridine imine, so that the catalyst has a unique main structure and a unique microenvironment, and further has unique physical and chemical properties including a wide cavity structure, a nano-scale size and molecular dissolving capacity, so that the catalyst has the characteristics of a homogeneous catalyst and a heterogeneous catalyst, and the problems of difficult separation of the homogeneous catalyst, poor catalytic capacity of the heterogeneous catalyst and the like are well solved.
Specifically, due to the synthesis of the star-shaped pyridine imine ligand structure, the nickel-based catalyst has a highly branched three-dimensional structure and a wide cavity structure, and has at least two advantages. On one hand, although the catalyst is a heterogeneous catalyst on the macroscopic scale and is insoluble in a reaction system, the star-shaped pyridine imine ligand structure enables the nickel-based catalyst to reach the nanoscale size and the dissolving capacity of nano molecules, and the characteristics of the nano material can ensure that the nickel-based catalyst has better dispersibility in the catalytic reaction system, is more fully contacted with catalytic reaction materials, embodies better catalytic activity, and is equivalent to a homogeneous catalyst. That is, the nickel-based catalyst has the characteristics that when the catalytic reaction is carried out, the dispersibility is good due to the nanometer characteristic, and the nickel-based catalyst can be used as a homogeneous catalyst to be fully contacted with reaction materials and shows higher catalytic activity; after the reaction is finished, the nickel catalyst is insoluble in a reaction system, embodies the characteristics of a heterogeneous catalyst, can be conveniently separated from the reaction system, and is high in cyclic utilization rate and long in service life.
The nickel catalyst has the characteristic of flexible molecular chains and does not contain a plurality of benzene ring structures, so that the nickel catalyst can be used for catalyzing ethylene oligomerization by combining the further exploration on the ethylene oligomerization catalytic reaction condition on the basis of the flexible nickel catalyst and adjusting the cavity size of the nickel catalyst molecule to obtain the purposes of narrow distribution and high selectivity of ethylene oligomerization products5g/(mol Ni. h), high value-added olefin C8To C18Higher olefin content, higher C in the product8-C18The mass percentage content is more than 31 percent, and the high-purity C can be obtained by simple separation8-C18An olefin.
Finally, the star-shaped pyridine imine nickel catalyst has the advantages of easily obtained preparation raw materials, simple preparation steps and mild reaction conditions, so that the preparation method has low cost, strong practicability and wide applicability.
Drawings
FIG. 1 is an infrared spectrum of a star-shaped pyridine imine nickel catalyst in the embodiment of the present application.
FIG. 2 is an ESI-MS spectrum of a star-shaped pyridine imine nickel catalyst in the example of the present application.
FIG. 3 is an infrared spectrum of the tri-star type nickel pyridine imine catalyst in the embodiment of the present application.
FIG. 4 is an ESI-MS spectrum of a starburst nickel pyridinimine catalyst according to the example of the present application.
FIG. 5 is an infrared spectrum of a penta-form nickel pyridinimine catalyst according to example of the present application.
FIG. 6 is an ESI-MS spectrum of a pentastar type nickel pyridinimine catalyst according to the examples of the present application.
Detailed Description
The technical solutions in the embodiments of the present application will be described clearly and completely below, and it should be apparent that the described embodiments are only a part of the embodiments of the present application, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.
It should be noted that the terms "comprises" and "comprising," and any variations thereof, in the embodiments of this application, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.
In addition, the reaction raw materials used in the examples of the present application are all commercially available.
Example one
This example provides a star-type pyridine imine nickel catalyst, which has the structural formula (I):
Figure BDA0002239584250000071
wherein R represents H.
The embodiment also provides a preparation method of the star-shaped pyridine imine nickel catalyst, which comprises the following steps: s1, adding pyridine-2-formaldehyde and anhydrous sodium sulfate into methanol at room temperature to form a reaction system, cooling the reaction system to 0 ℃ under the condition of nitrogen, adding an organic solution of a compound shown in a structural formula (II), wherein the organic solvent in the organic solution is methanol, reacting for 30min, stirring and heating to 25 ℃, continuously stirring and reacting for 24h, and filtering under negative pressure after the reaction is finished to obtain a filtrate; wherein the molar ratio of the compound shown in the structural formula (II) to the pyridine-2-carbaldehyde is 1:5, and the mass of the anhydrous sodium sulfate is 3.0 g.
Figure BDA0002239584250000081
S2, slowly dropwise adding an organic solution of nickel chloride hexahydrate into the filtrate obtained in the step S1 under the condition of nitrogen to form a reaction solution, wherein an organic solvent adopted in the organic solution of nickel chloride hexahydrate is methanol, and the molar ratio of the compound in the structural formula (II) to the nickel chloride hexahydrate is 1: 3.5; stirring and reacting for 24h at 25 ℃, adding 100mL of diethyl ether into the reaction solution after the reaction is finished for post-treatment to separate out a green solid, filtering and collecting the green solid, repeatedly washing the green solid for 3 times by using anhydrous diethyl ether, and drying the washed green solid to constant weight under a vacuum condition to obtain the star-shaped pyridine imine nickel catalyst of the embodiment. The yield of the star-shaped pyridinimine nickel-based catalyst of this example was calculated to be 72.19%.
The star-shaped pyridine imine nickel-based catalyst of the present example was subjected to structural analysis, and as shown in FIG. 1, it was observed at 3228cm in an infrared spectrum-1And 3069cm-1Near the absorption peaks of N-H on amido bond and C-H telescopic vibration characteristic absorption peaks on pyridine ring respectively appear at 1608cm-1A stretching vibration characteristic absorption peak of-C-N-appears nearby, which shows that the terminal primary amine of the compound with the structural formula (II) and pyridine-2-formaldehyde have Schiff base reaction;
as shown in FIG. 2, an excimer ion peak [ M ] of a starburst nickel pyridinimide compound at M/z 1016 was observed in the ESI-MS spectrum]+(ii) a M/z 803 is a fragment ion peak [ M-6Cl ] formed by 6Cl loss during compound cleavage]+(ii) a Further cracking to lose 3Ni formed fragment ion peak [ M-6Cl-3Ni]+Appearing at m/z 626. The ESI-MS is electrospray ionization mass spectrometry, and is called electrophoresis ionization mass spectrometry for short.
Example two
This example provides a star-type pyridine imine nickel catalyst, which has the structural formula (I):
Figure BDA0002239584250000091
wherein R represents H.
The embodiment also provides a preparation method of the star-shaped pyridine imine nickel catalyst, which comprises the following steps:
s1, adding pyridine-2-formaldehyde and anhydrous sodium sulfate into ethanol at room temperature to form a reaction system, cooling the reaction system to 0 ℃ under the condition of nitrogen, adding an organic solution of a compound shown in a structural formula (II), wherein the organic solvent in the organic solution is ethanol, reacting for 30min, stirring and heating to 35 ℃, continuously stirring and reacting for 24h, and filtering under negative pressure after the reaction is finished to obtain a filtrate; wherein the molar ratio of the compound shown in the structural formula (II) to the pyridine-2-carbaldehyde is 1:6, and the mass of the anhydrous sodium sulfate is 3.0 g.
Figure BDA0002239584250000092
S2, slowly dropwise adding an organic solution of nickel chloride hexahydrate into the filtrate obtained in the step S1 under the condition of nitrogen to form a reaction solution, wherein an organic solvent adopted in the organic solution of nickel chloride hexahydrate is ethanol, and the molar ratio of the compound in the structural formula (II) to the nickel chloride hexahydrate is 1: 4; stirring and reacting for 24h at 25 ℃, adding 100mL of diethyl ether into the reaction solution after the reaction is finished for post-treatment to separate out a green solid, filtering and collecting the green solid, repeatedly washing the green solid for 3 times by using anhydrous diethyl ether, and drying the washed green solid to constant weight under a vacuum condition to obtain the star-shaped pyridine imine nickel catalyst of the embodiment.
The infrared spectrum and ESI-MS spectrum of this example are the same as those of the first example, and are not provided and described herein.
EXAMPLE III
This example provides a star-type pyridine imine nickel catalyst, which has the structural formula (I):
Figure BDA0002239584250000101
wherein R represents CH3
The embodiment also provides a preparation method of the star-shaped pyridine imine nickel catalyst, which comprises the following steps:
s1, adding 6-methyl-2-pyridinecarboxaldehyde and anhydrous sodium sulfate into methanol at room temperature to form a reaction system, cooling the reaction system to 0 ℃ under the condition of nitrogen, adding an organic solution of a compound shown in a structural formula (II), wherein an organic solvent in the organic solution is methanol, reacting for 30min, stirring and heating to 25 ℃, continuously stirring and reacting for 24h, and filtering under negative pressure after the reaction is finished to obtain a filtrate; wherein the molar ratio of the compound shown in the structural formula (II) to 6-methyl-2-pyridinecarbaldehyde is 1:5, and the mass of the anhydrous sodium sulfate is 3.0 g.
Figure BDA0002239584250000111
S2, slowly dropwise adding an organic solution of nickel chloride hexahydrate into the filtrate obtained in the step S1 under the condition of nitrogen to form a reaction solution, wherein an organic solvent adopted in the organic solution of nickel chloride hexahydrate is methanol, and the molar ratio of the compound in the structural formula (II) to the nickel chloride hexahydrate is 1: 3.5; stirring and reacting for 24h at 25 ℃, adding 100mL of diethyl ether into the reaction solution after the reaction is finished for post-treatment to separate out a green solid, filtering and collecting the green solid, repeatedly washing the green solid for 3 times by using anhydrous diethyl ether, and drying the washed green solid to constant weight under a vacuum condition to obtain the star-shaped pyridine imine nickel catalyst of the embodiment.
The structure of the star-shaped pyridinimine nickel-based catalyst of this example was analyzed, and as shown in FIG. 3, it was observed at 3228cm in an infrared spectrum-1And 3069cm-1Near the absorption peaks of N-H on amido bond and C-H telescopic vibration characteristic absorption peaks on pyridine ring respectively appear at 1608cm-1A stretching vibration characteristic absorption peak of-C-N-appears nearby, which shows that the terminal primary amine of the compound with the structural formula (II) and pyridine-2-formaldehyde have Schiff base reaction;
as shown in FIG. 4, an excimer ion peak [ M ] of a starburst nickel pyridinimide compound at M/z 1058 was observed in the ESI-MS spectrum]+(ii) a M/z 845 is the fragment ion peak [ M-6Cl ] formed by 6Cl loss during compound cleavage]+(ii) a Further cracking to lose 3Ni formed fragment ion peak [ M-6Cl-3Ni]+Appearing at m/z 668.
Example four
This example provides a star-type pyridine imine nickel catalyst, which has the structural formula (I):
Figure BDA0002239584250000121
wherein R represents CH3
The embodiment also provides a preparation method of the star-shaped pyridine imine nickel catalyst, which comprises the following steps:
s1, adding 6-methyl-2-pyridinecarboxaldehyde and anhydrous sodium sulfate into ethanol at room temperature to form a reaction system, cooling the reaction system to 0 ℃ under the condition of nitrogen, adding an organic solution of a compound shown in a structural formula (II), wherein the organic solvent in the organic solution is ethanol, reacting for 30min, stirring and heating to 35 ℃, continuously stirring and reacting for 24h, and filtering under negative pressure after the reaction is finished to obtain a filtrate; wherein the molar ratio of the compound shown in the structural formula (II) to 6-methyl-2-pyridinecarbaldehyde is 1:6, and the mass of the anhydrous sodium sulfate is 3.0 g.
Figure BDA0002239584250000122
S2, slowly dropwise adding an organic solution of nickel chloride hexahydrate into the filtrate obtained in the step S1 under the condition of nitrogen to form a reaction solution, wherein an organic solvent adopted in the organic solution of nickel chloride hexahydrate is ethanol, and the molar ratio of the compound in the structural formula (II) to the nickel chloride hexahydrate is 1: 4; stirring and reacting for 24h at 25 ℃, adding 100mL of diethyl ether into the reaction solution after the reaction is finished for post-treatment to separate out a green solid, filtering and collecting the green solid, repeatedly washing the green solid for 3 times by using anhydrous diethyl ether, and drying the washed green solid to constant weight under a vacuum condition to obtain the star-shaped pyridine imine nickel catalyst of the embodiment.
The infrared spectrum and ESI-MS spectrum of this example are the same as those of the example, and are not provided and described herein.
EXAMPLE five
This example provides a star-type pyridine imine nickel catalyst, which has the structural formula (I):
Figure BDA0002239584250000131
wherein R represents Br.
The embodiment also provides a preparation method of the star-shaped pyridine imine nickel catalyst, which comprises the following steps:
s1, adding 6-bromo-2-pyridinecarboxaldehyde and anhydrous sodium sulfate into methanol at room temperature to form a reaction system, cooling the reaction system to 0 ℃ under the condition of nitrogen, adding an organic solution of a compound shown in a structural formula (II), wherein an organic solvent in the organic solution is methanol, reacting for 30min, stirring and heating to 25 ℃, continuously stirring and reacting for 24h, and filtering under negative pressure after the reaction is finished to obtain a filtrate; wherein the molar ratio of the compound shown in the structural formula (II) to 6-methyl-2-pyridinecarbaldehyde is 1:5, and the mass of the anhydrous sodium sulfate is 3.0 g.
Figure BDA0002239584250000141
S2, slowly dropwise adding an organic solution of nickel chloride hexahydrate into the filtrate obtained in the step S1 under the condition of nitrogen to form a reaction solution, wherein an organic solvent adopted in the organic solution of nickel chloride hexahydrate is methanol, and the molar ratio of the compound in the structural formula (II) to the nickel chloride hexahydrate is 1: 3.5; stirring and reacting for 24h at 25 ℃, adding 100mL of diethyl ether into the reaction solution after the reaction is finished for post-treatment to separate out a green solid, filtering and collecting the green solid, repeatedly washing the green solid for 3 times by using anhydrous diethyl ether, and drying the washed green solid to constant weight under a vacuum condition to obtain the star-shaped pyridine imine nickel catalyst of the embodiment.
To this implementationStructural analysis of the star-shaped pyridinimine nickel-based catalyst was carried out, and it was observed at 3228cm in an infrared spectrum as shown in FIG. 5-1And 3069cm-1Near the absorption peaks of N-H on amido bond and C-H telescopic vibration characteristic absorption peaks on pyridine ring respectively appear at 1608cm-1A stretching vibration characteristic absorption peak of-C-N-appears nearby, which shows that the terminal primary amine of the compound with the structural formula (II) and pyridine-2-formaldehyde have Schiff base reaction;
as shown in FIG. 6, an excimer ion peak [ M ] of a starburst nickel pyridinimide compound at M/z 1253 was observed in the ESI-MS spectrum]+(ii) a At M/z 1040 is the fragment ion peak [ M-6Cl ] formed by 6Cl loss during compound cleavage]+(ii) a Further cracking to lose 3Ni formed fragment ion peak [ M-6Cl-3Ni]+At m/z 863.
EXAMPLE six
This example provides a star-type pyridine imine nickel catalyst, which has the structural formula (I):
Figure BDA0002239584250000151
wherein R represents Br.
The embodiment also provides a preparation method of the star-shaped pyridine imine nickel catalyst, which comprises the following steps:
s1, adding 6-bromo-2-pyridinecarboxaldehyde and anhydrous sodium sulfate into ethanol at room temperature to form a reaction system, cooling the reaction system to 0 ℃ under the condition of nitrogen, adding an organic solution of a compound shown in a structural formula (II), wherein an organic solvent in the organic solution is ethanol, reacting for 30min, stirring and heating to 35 ℃, continuously stirring and reacting for 24h, and filtering under negative pressure after the reaction is finished to obtain a filtrate; wherein the molar ratio of the compound shown in the structural formula (II) to 6-methyl-2-pyridinecarbaldehyde is 1:6, and the mass of the anhydrous sodium sulfate is 3.0 g.
Figure BDA0002239584250000152
S2, slowly dropwise adding an organic solution of nickel chloride hexahydrate into the filtrate obtained in the step S1 under the condition of nitrogen to form a reaction solution, wherein an organic solvent adopted in the organic solution of nickel chloride hexahydrate is ethanol, and the molar ratio of the compound in the structural formula (II) to the nickel chloride hexahydrate is 1: 4; stirring and reacting for 24h at 25 ℃, adding 100mL of diethyl ether into the reaction solution after the reaction is finished for post-treatment to separate out a green solid, filtering and collecting the green solid, repeatedly washing the green solid for 3 times by using anhydrous diethyl ether, and drying the washed green solid to constant weight under a vacuum condition to obtain the star-shaped pyridine imine nickel catalyst of the embodiment.
The infrared spectrum and ESI-MS spectrum of this example are the same as those of example V, and are not provided and described herein.
The star-shaped pyridine imine nickel-based catalyst obtained in the first to sixth embodiments of the application has a wide cavity structure and a nano-scale size, so that the nickel-based catalyst has the characteristics of a homogeneous catalyst and a heterogeneous catalyst. On one hand, the catalyst presents the characteristics of nano particles through a star-shaped structure, so that after the star-shaped pyridine imine nickel catalyst is put into a catalytic reaction system, the star-shaped pyridine imine nickel catalyst can be fully contacted with reaction materials by virtue of the nano-scale size of the star-shaped pyridine imine nickel catalyst, good molecular dissolving capacity is realized, catalytic reaction activity is improved, and the characteristics of a homogeneous catalyst are embodied. On the other hand, the nickel-based catalyst is not dissolved in the reaction system, so that the nickel-based catalyst can be separated from the reaction system by conventional means such as centrifugation after the reaction is finished, and can be recycled, so that the nickel-based catalyst has a long service life, and the problems that the homogeneous catalyst is difficult to separate or the separation loss rate is high cannot occur.
Moreover, the structural characteristics of the star-shaped pyridine imine nickel catalyst can also show that the ligand structure of the catalyst has no more benzene ring structures, only a small amount of ring structures are arranged at the tail end of the whole structure, but the middle of the structure is a longer flexible molecular chain, and the star-shaped structures with more flexible molecular chains ensure that the rigidity of the nickel catalyst is not too strong, so that when the catalyst is used for catalyzing ethylene oligomerization, the adjustment of the molecular cavity size of the nickel catalyst can be further realized by exploring reaction conditions, and the purposes of narrowing the product distribution and obtaining high-selectivity olefin products are achieved.
Preparation example 1
The preparation example provides application of a star-type pyridine imine nickel catalyst in preparation of α -olefin by ethylene oligomerization, and specifically provides application of the star-type pyridine imine nickel catalyst in preparation of α -olefin.
The preparation method of α -olefin comprises the steps of vacuumizing a reaction system with a drying function and a stirring function, replacing the reaction system with ethylene for three times, adding the star-shaped pyridinimine nickel-based catalyst of the first embodiment, toluene as a second organic solvent and methylaluminoxane as a cocatalyst, introducing ethylene to the reaction system until the pressure is 0.5MPa, keeping the ethylene pressure constant, stirring the reaction system at 10 ℃ for 30min, and emptying the reaction system to normal pressure to obtain α -olefin, wherein the molar ratio of aluminum in the methylaluminoxane to nickel in the star-shaped pyridinimine nickel-based catalyst is 500: 1.
Wherein the structural formula of the star-shaped pyridine imine nickel catalyst is as follows:
Figure BDA0002239584250000171
wherein R is H.
Preparation example two
The present preparation example differs from the first preparation example only in the catalyst used in the present preparation example. The structural formula of the star-shaped pyridine imine nickel catalyst used in the preparation example is as follows:
Figure BDA0002239584250000181
wherein R is CH3
The α -olefin is prepared by vacuumizing a reaction system with a drying function and a stirring function, replacing the reaction system with ethylene for three times, adding the star-shaped pyridinimine nickel-based catalyst of the third embodiment, toluene as a second organic solvent and methylaluminoxane as a cocatalyst, introducing ethylene to the reaction system until the pressure is 0.5MPa, keeping the ethylene pressure constant, stirring the mixture at 10 ℃ for reaction for 30min, and emptying the reaction system to normal pressure to obtain α -olefin, wherein the molar ratio of aluminum in the methylaluminoxane to nickel in the star-shaped pyridinimine nickel-based catalyst is 500: 1.
Preparation example three
The present preparation example differs from the first preparation example only in the catalyst used in the present preparation example. The structural formula of the star-shaped pyridine imine nickel catalyst used in the preparation example is as follows:
Figure BDA0002239584250000191
wherein R is Br.
The α -olefin is prepared by vacuumizing a reaction system with a drying function and a stirring function, replacing the reaction system with ethylene for three times, adding the star-shaped pyridinimine nickel-based catalyst of the fifth embodiment, toluene as a second organic solvent and methylaluminoxane as a cocatalyst, introducing ethylene to the reaction system until the pressure is 0.5MPa, keeping the ethylene pressure constant, stirring the mixture at 10 ℃ for reaction for 30min, and emptying the reaction system to normal pressure to obtain α -olefin, wherein the molar ratio of aluminum in the methylaluminoxane to nickel in the star-shaped pyridinimine nickel-based catalyst is 500: 1.
Preparation example four
The present preparation example differs from preparation example three only in that methylcyclohexane is used as the second organic solvent in the present preparation example.
Preparation example five
The present preparation example differs from preparation example three only in that cyclohexane is used as the second organic solvent in the present preparation example.
Preparation example six
The preparation example differs from the third preparation example only in that the temperature of the catalytic reaction in this example is 20 ℃.
Preparation example seven
The preparation example differs from the third preparation example only in that the temperature of the catalytic reaction in this example is 30 ℃.
Preparation example eight
The preparation example differs from the third preparation example only in that the temperature of the catalytic reaction in this example is 40 ℃.
Preparation example nine
The preparation example differs from the third preparation example only in that the temperature of the catalytic reaction in this example is 50 ℃.
Preparation example ten
The difference between the preparation example and the third preparation example is that the molar ratio of the aluminum element in the methylaluminoxane to the nickel element in the star-shaped pyridine imine nickel-based catalyst is 300: 1.
Preparation example eleven
The difference between the preparation example and the third preparation example is that the molar ratio of the aluminum element in the methylaluminoxane to the nickel element in the star-shaped pyridine imine nickel-based catalyst in the preparation example is 700: 1.
Preparation example twelve
The difference between the preparation example and the third preparation example is that the molar ratio of the aluminum element in the methylaluminoxane to the nickel element in the star-shaped pyridine imine nickel-based catalyst is 1000: 1.
Preparation example thirteen
The difference between the preparation example and the third preparation example is that the molar ratio of the aluminum element in the methylaluminoxane to the nickel element in the star-shaped pyridine imine nickel-based catalyst is 1500: 1.
Preparation example fourteen
The difference between the preparation example and the third preparation example is that ethylene was introduced into the reaction vessel to a pressure of 0.1 MPa.
Preparation example fifteen
The difference between the preparation example and the third preparation example is that ethylene was introduced into the reaction vessel to a pressure of 0.3 MPa.
Preparation example sixteen
The difference between the preparation example and the third preparation example is that ethylene was introduced into the reaction vessel to a pressure of 0.7 MPa.
Preparation example seventeen
The difference between the preparation example and the third preparation example is that ethylene was introduced into the reaction vessel to a pressure of 1.0 MPa.
Comparative preparation example 1
The comparative preparation example is different from the third preparation example only in that the catalyst used in the comparative preparation example is a conventional non-star-shaped nickel pyridinimine catalyst.
The preparation method of α -olefin comprises the steps of vacuumizing a reaction system with a drying function and a stirring function, replacing the reaction system with ethylene for three times, adding a non-star-shaped pyridimine nickel catalyst with the structural formula (III), toluene as a second organic solvent and methylaluminoxane as a cocatalyst, introducing ethylene to the reaction system until the pressure is 0.5MPa, keeping the ethylene pressure constant, stirring the reaction system at 10 ℃ for 30min, and emptying the reaction system to normal pressure to obtain α -olefin, wherein the molar ratio of aluminum elements in the methylaluminoxane to nickel elements in the non-star-shaped pyridimine nickel catalyst with the structural formula (III) is 500: 1.
Figure BDA0002239584250000211
Comparative preparation example 2
The comparative preparation example is different from the third preparation example only in that the catalyst used in the comparative preparation example is a conventional non-star-shaped nickel pyridinimine catalyst.
The preparation method of α -olefin comprises the steps of vacuumizing a reaction system with a drying function and a stirring function, replacing the reaction system with ethylene for three times, adding a non-star-shaped pyridimine nickel catalyst with the structural formula (IV), toluene as a second organic solvent and methylaluminoxane as a cocatalyst, introducing ethylene to the reaction system until the pressure is 0.5MPa, keeping the ethylene pressure constant, stirring the reaction system at 10 ℃ for 30min, and emptying the reaction system to normal pressure to obtain α -olefin, wherein the molar ratio of aluminum elements in the methylaluminoxane to nickel elements in the non-star-shaped pyridimine nickel catalyst with the structural formula (IV) is 500: 1.
Figure BDA0002239584250000221
Performance testing
1. Effect of different types of catalysts on catalytic Activity and Selectivity
The results of gas phase analysis of the catalytic activity of the catalysts of preparation example three, comparative preparation example one and comparative preparation example two and the products after the reaction are shown in table 1:
Figure BDA0002239584250000222
table 1: catalytic activity and product analysis results of preparation example three, comparative preparation example one and comparative preparation example two
As can be seen from the results in table 1, the nickel-based catalyst of the present invention has excellent catalytic activity and selectivity to higher olefins. Compared with the existing non-star-shaped pyridine imine nickel catalyst, the star-shaped pyridine imine nickel catalyst in the embodiment of the application has higher catalytic activity, and C in the oligomerization product8-C18The content of the olefin is high and can reach 26.76%, which shows that the nickel-based catalyst can obviously improve the catalytic activity and the selectivity to high-carbon olefin in the application of preparing α olefin.
2. Effect of different functional groups on catalytic Activity and Selectivity
In order to study the influence of functional groups with different structures on catalytic activity and selectivity, the catalytic activity and the products after reaction of the star-type pyridine imine nickel catalysts in the first to third preparation examples are subjected to gas phase analysis, and the results are shown in table 2:
Figure BDA0002239584250000223
Figure BDA0002239584250000231
table 2: catalytic activity and product analysis results of preparation examples one to three
From the results in table 2, it can be seen that the star-type nickel pyridinimine catalyst, especially the star-type nickel pyridinimine, can indeed exhibit good catalytic activity in the method for preparing α -olefin by oligomerization of ethylene using the star-type nickel pyridinimine catalyst of the present application exampleWhen R in the catalyst is Br, the catalytic activity can reach 1.34 multiplied by 105g/(mol Ni. h)). The structure of the nickel-based catalyst in the embodiment of the present application is analyzed by combining the results in table 1, and the applicant believes that as the electron withdrawing effect of the star-type pyridine imine nickel-based catalyst is enhanced, the electron cloud density of the active metal center is reduced, which is beneficial to activating the cocatalyst to form an active center with an empty orbit for ethylene molecule coordination, so that the number of effective active centers in the system is increased, and ethylene participating in coordination and insertion reactions is increased, so that the catalytic activity is increased.
In addition, the electron-withdrawing effect is beneficial to the chain growth reaction, and C in the oligomerization product is added along with the enhancement of the electron-withdrawing effect8-C18The olefin content is gradually increased, and good selectivity for high-carbon olefin is shown; especially when R in the star-shaped pyridine imine nickel-based catalyst is Br, the catalyst is opposite to C8-C18The selectivity of olefin reaches 26.76 wt%. The star-shaped pyridine imine nickel catalyst has good application prospect and industrial popularization value in the field of petrochemical industry due to the catalytic characteristics.
3. Influence of different organic solvents on catalytic activity and selectivity
In order to study the influence of different organic solvents on the catalytic activity and selectivity in the process of preparing α -olefin, the application performs gas phase analysis on the catalytic activity of the three to five star-shaped pyridine imine nickel catalysts in the preparation examples and the products after the reaction, and the results are shown in table 3:
table 3: catalytic activity and product analysis results of preparation examples three to five
As can be seen from the above Table 3, although α -olefin prepared by using the same star-type nickel pyridinimine catalyst has better catalytic performance, different solvents used in the preparation process have certain influence on the catalytic activity and product distribution of the catalystC8-C18The selectivity of olefin is best (C)8-C18High olefins are very important target products), catalytic activity is reduced when methylcyclohexane and cyclohexane are used as the second organic solvent, and C8-C18The olefin selectivity also decreases.
4. Influence of different reaction temperatures on catalytic activity and selectivity
The application carries out gas-phase analysis on the catalytic activity of the star-shaped pyridine imine nickel catalyst in preparation example three, preparation example six to preparation example nine and the product after reaction so as to research the influence of different catalytic reaction temperatures on the catalytic performance in the method for preparing α -olefin, and the results are shown in table 4:
Figure BDA0002239584250000241
table 4: catalytic activity and product analysis results of preparation example three and preparation examples six to nine
As can be seen from the above Table 4, although α -olefin prepared by using the same star-shaped pyridine imine nickel-based catalyst has better catalytic performance, the temperature of the catalytic reaction in the preparation process has a certain influence on the catalytic activity and the product distribution of the catalyst, specifically, when the reaction temperature is 10 ℃, the catalytic activity is the maximum, and C is the maximum8-C18The selectivity to olefin is also optimal and as temperature continues to rise, the catalytic activity decreases. The applicant analyzes and believes that the reason is that the ethylene molecule solubility in an oligomerization system is reduced along with the increase of the temperature, the effective ethylene molecular weight participating in the reaction is reduced, the oligomerization reaction rate is reduced, and the catalytic activity is reduced; at the same time, the rate of catalyst deactivation increases with increasing temperature, which is another major cause of reduced catalytic activity. In addition, as the temperature increases, the rate of chain growth decreases and C in the oligomeric product8-C18The preferred reaction temperature for the preparation of α -olefin herein is 10 c, all in all considerations.
5. Influence of different Al/Ni molar ratios on catalytic activity and selectivity
The present application carried out gas phase analysis on the catalytic activity of the star-type pyridine imine nickel catalyst in preparation example three, preparation example ten to thirteen and the product after reaction to study the influence of different Al/Ni molar ratios on the catalytic performance in the method for preparing α -olefin, the results are shown in Table 5:
Figure BDA0002239584250000242
table 5: catalytic activity and product analysis results of preparation example three, preparation examples ten to thirteen
As can be seen from the above Table 5, although α -olefin prepared by using the same star-shaped pyridine imine nickel catalyst has better catalytic performance, the molar ratio of Al to Ni in the preparation process has a certain influence on the catalytic activity and the product distribution of the catalyst8-C18The selectivity to olefin then shows a decreasing trend. The analysis reason is that when the molar ratio of Al/Ni is small, part of methylaluminoxane is used for eliminating water and oxygen remained in the reaction system, the remained methylaluminoxane is not enough for activating the catalyst into active species completely, and the number of the activated active species of the catalyst is increased along with the increase of the molar ratio of Al/Ni, so that the catalytic activity is improved; when the molar ratio of Al/Ni is more than 1000:1, an excessive amount of methylaluminoxane accumulates at the metal active site, resulting in deactivation of the catalyst, thereby deteriorating catalytic activity. Furthermore, as the Al/Ni molar ratio increases, the chain transfer rate increases, and C8-C18The olefin selectivity decreases. The catalytic activity is highest when the molar ratio of Al/Ni is 1000:1, but in this case, for C8-C18The selectivity to olefin is somewhat low; when the molar ratio of Al to Ni is 300:1, for C8-C18The selectivity to olefins is higher but the catalytic activity is slightly lower. In order to combine catalytic activity and selectivity of higher olefins, the molar ratio of Al/Ni is defined hereinThe molar ratio is preferably 500: 1.
6. Effect of different ethylene pressures on catalytic Activity and Selectivity
The application carries out gas phase analysis on the catalytic activity of the star-shaped pyridine imine nickel catalyst in preparation example III and preparation example fourteen to seventeen and the product after reaction so as to research the influence of different reaction pressures on the catalytic performance in the method for preparing α -olefin, and the results are shown in Table 6:
Figure BDA0002239584250000252
table 6: preparation example III, preparation examples fourteen to seventeen catalytic activity and product analysis results
As can be seen from the above Table 6, although α -olefin prepared by using the same star-shaped pyridinimine nickel-based catalyst has better catalytic performance, the ethylene pressure condition in the preparation process has a certain influence on the catalytic activity and product distribution of the catalyst8-C18The selectivity to olefin also gradually increases. This phenomenon occurs because the solubility of ethylene molecules in the system increases with increasing pressure, the amount of ethylene reacting with the active sites per unit time increases, and the catalytic activity increases; in addition, as the ethylene pressure increases, the rate of chain extension reaction increases by a greater extent than the rate of chain transfer reaction, so C in the product8-C18The higher olefin selectivity increases with increasing ethylene pressure. When the ethylene pressure is 1.0MPa, the catalytic activity reaches 4.39 multiplied by 105g/(molNi. h), for C8-C18The selectivity to olefin is 31.93%, so the present application preferably uses reaction conditions where the ethylene pressure is 1.0 MPa.
In conclusion, the nickel-based catalyst with the star-shaped pyridine imine structure is designed and prepared, and the unique main structure and the unique microenvironment of the nickel-based catalyst are utilized, so that the nickel-based catalyst has the dual advantages of a homogeneous catalyst and a heterogeneous catalyst. In addition, the star-shaped pyridine imine nickel catalyst has the advantages of easily obtained raw materials, simple method steps, mild and mild conditions, and the nickel catalyst has good industrial applicability and wide industrial application prospect.
The star-shaped pyridine imine nickel catalyst is used in the ethylene oligomerization reaction, and shows good selectivity on high-carbon olefin, which is difficult to achieve by nickel catalysts with other star-shaped structures or other structures, thereby showing that the star-shaped structure with more flexible molecular chains and longer flexible molecular chains can really have good catalytic activity and good product selectivity.
The star-shaped pyridine imine nickel-based catalyst disclosed in the embodiment of the application, the preparation method and the application thereof are described in detail, the principle and the implementation mode of the application are explained by applying specific examples, and the description of the examples is only used for helping to understand the method and the core idea of the application; meanwhile, for a person skilled in the art, according to the idea of the present application, there may be variations in the specific embodiments and the application scope, and in summary, the content of the present specification should not be construed as a limitation to the present application.

Claims (10)

1. The star-shaped pyridine imine nickel catalyst is characterized in that the structural formula (I) of the star-shaped pyridine imine nickel catalyst is as follows:
Figure FDA0002239584240000011
wherein R is selected from H, Br and CH3One kind of (1).
2. The preparation method of the star-shaped pyridine imine nickel-based catalyst according to claim 1, characterized by comprising the following steps:
s1, adding pyridine-2 formaldehyde or a pyridine-2 formaldehyde substituent and a water absorbent into a first organic solvent to form a reaction system, cooling the reaction system to-5 ℃ under the condition of inert gas, adding an organic solution of a compound with a structural formula (II), reacting for 15-60min, stirring and heating to 20-40 ℃, continuously stirring and reacting for 20-40h, and filtering after reaction to obtain a filtrate;
and S2, reacting the filtrate with an organic solution of nickel chloride hexahydrate under the condition of inert gas at the temperature of 20-40 ℃ for 20-40 hours under stirring to obtain the star-shaped pyridine imine nickel catalyst.
3. The method of claim 2, wherein the step of S1 is: adding pyridine-2-formaldehyde or a pyridine-2-formaldehyde substitute and the water absorbent into the first organic solvent at room temperature to form a reaction system, cooling the reaction system to 0 ℃ under the condition of inert gas, adding the organic solution of the compound of the structural formula (II), reacting for 30min, stirring and heating to 25 ℃, continuously stirring and reacting for 24h, and filtering under negative pressure after the reaction to obtain the filtrate; wherein the molar ratio of the compound of the structural formula (II) to the pyridine-2-carbaldehyde or the substituent of the pyridine-2-carbaldehyde is 1:5-1: 6.
4. The method of claim 2, wherein the step of S2 is: slowly dropwise adding the organic solution of nickel chloride hexahydrate into the filtrate under the condition of inert gas to form a reaction solution, stirring and reacting for 24 hours at 25 ℃, and carrying out post-treatment on the reaction solution after reaction to obtain the star-shaped pyridine imine nickel catalyst; wherein the molar ratio of the compound shown in the structural formula (II) to the nickel chloride hexahydrate is 1:3-1: 4.
5. The method of claim 4, wherein: in the step S2, the post-processing is: and adding ether into the reaction solution after the reaction to separate out a green solid, filtering and collecting the green solid, washing the green solid with anhydrous ether, and drying the washed green solid to constant weight under a vacuum condition to obtain the star-shaped pyridine imine nickel catalyst.
6. The production method according to any one of claims 2 to 5, characterized in that: in the preparation method, the substitute of the pyridine-2-formaldehyde is selected from 6-methyl-2-pyridine-formaldehyde or 6-bromo-2-pyridine-formaldehyde, and the water absorbent is selected from anhydrous sodium sulfate, anhydrous magnesium sulfate or anhydrous calcium chloride; the inert gas is selected from nitrogen, helium or argon; the first organic solvent in the step S1 is one or a mixture of two of methanol and ethanol; the solvent used in the organic solution of the compound of the structural formula (II) and the solvent used in the organic solution of the nickel chloride hexahydrate are both selected from one or a mixture of two of methanol and ethanol.
7. Use of the star-type nickel pyridinimine catalyst of claim 1 in the oligomerization of ethylene to α -olefin.
8. A method for preparing α -olefin, which is characterized in that the method comprises the steps of dissolving the star-shaped pyridine imine nickel-based catalyst prepared by the preparation method of any one of claims 2 to 6 in a second organic solvent, adding a cocatalyst, and introducing ethylene for reaction to obtain the α -olefin.
9. The method of claim 8, which is characterized in that the star-shaped pyridine imine nickel catalyst is dissolved in the second organic solvent, a cocatalyst is added, ethylene is introduced to 0.1-1.0MPa, the ethylene pressure is constant, and the mixture is stirred and reacted at 10-50 ℃ to obtain α -olefin, wherein the cocatalyst is methylaluminoxane, the molar ratio of aluminum elements in the methylaluminoxane to nickel elements in the star-shaped pyridine imine nickel catalyst is 300:1-1500:1, and the second organic solvent is one or a mixture of toluene, methylcyclohexane or cyclohexane.
10. The method of claim 9, wherein the star-shaped pyridine imine nickel catalyst is dissolved in toluene, methylaluminoxane is added, ethylene is introduced to 1.0MPa, the ethylene pressure is constant, and the mixture is stirred and reacted at 10 ℃ to obtain the α -olefin, wherein the molar ratio of aluminum in the methylaluminoxane to nickel in the star-shaped pyridine imine nickel catalyst is 500: 1.
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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113880885A (en) * 2021-09-27 2022-01-04 东北石油大学 Catalyst for ethylene oligomerization, preparation method thereof and catalysis method
CN114702529A (en) * 2022-05-09 2022-07-05 东北石油大学 Phthalocyanine nickel complex, preparation method thereof and application thereof in ethylene oligomerization

Non-Patent Citations (4)

* Cited by examiner, † Cited by third party
Title
NA ZHANG等: "Iron, cobalt and nickel complexes bearing hyperbranched iminopyridyl ligands: Synthesis, characterization and evaluation as ethylene oligomerization catalysts", 《INORGANICA CHIMICA ACTA》 *
XINXIN ZHAO等: "Synthesis and cytotoxic activities of chloropyridylimineplatinum(Ⅱ) and chloropyridyliminecopper(Ⅱ) surface-functionalized poly(amidoamine) dendrimers", 《JOURNAL OF INORGANIC BIOCHEMISTRY》 *
张娜: "超支化金属催化剂的合成及催化乙烯齐聚性能研究", 《中国博士学位论文全文数据库工程科技Ⅰ辑》 *
鲁慧霞等: "聚酰胺-胺-2-吡啶甲醛席夫碱树枝状大分子钯配合物的制备、表征及催化性能", 《应用化学》 *

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113880885A (en) * 2021-09-27 2022-01-04 东北石油大学 Catalyst for ethylene oligomerization, preparation method thereof and catalysis method
CN114702529A (en) * 2022-05-09 2022-07-05 东北石油大学 Phthalocyanine nickel complex, preparation method thereof and application thereof in ethylene oligomerization
CN114702529B (en) * 2022-05-09 2023-08-11 东北石油大学 Nickel phthalocyanine complex, preparation method thereof and application thereof in ethylene oligomerization

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