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A class of large sterically hindered α-diimine ligands, nickel catalysts, preparation methods and applications thereof

A diimine ligand and catalyst technology, applied in the preparation of imino compounds, organic chemistry, etc., can solve the problems of high temperature and high pressure, harsh conditions, and low molecular weight of copolymers

Active Publication Date: 2021-12-24
CHANGCHUN INST OF APPLIED CHEMISTRY - CHINESE ACAD OF SCI
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0006] However, the α-diimine catalysts in the prior art have the following two problems: 1) the molecular weight of the obtained copolymer is very low, generally below 10,000; 2) the conditions are relatively harsh, usually requiring high temperature and high pressure

Method used

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  • A class of large sterically hindered α-diimine ligands, nickel catalysts, preparation methods and applications thereof
  • A class of large sterically hindered α-diimine ligands, nickel catalysts, preparation methods and applications thereof
  • A class of large sterically hindered α-diimine ligands, nickel catalysts, preparation methods and applications thereof

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0074] Step 1, the preparation of 4-methyl-2,6-bis(4,4,5,5-tetramethyl-1,3,2-dioxaborolane) aniline

[0075]

[0076] Under a nitrogen atmosphere, 2,6-dibromo-4-methylaniline (0.50g, 1.9mmol), bis(pinacol)diborane (1.44g, 5.7mmol), potassium acetate (0.55g, 5.6 mmol) and [1,1′-bis(diphenylphosphino)ferrocene]palladium dichloride (0.028 g) were dissolved in dimethyl sulfoxide (20 mL), then stirred at 80° C. for 24 h. After the reaction was completed, the black-red liquid mixture was poured into ice water (50 mL) and the precipitate was filtered. The precipitate was redissolved in dichloromethane, the organic layer was washed with water, separated and dried over sodium sulfate. After filtration, the organic phase was concentrated by rotary evaporation. By flash column chromatography (silica gel; PE / CH 2 Cl 2 = 3:1) to purify the resulting residue and then use CH 2 Cl 2 / CH 3 Recrystallization from OH afforded 0.40 g (60% yield) of the product as yellow-white crystals. ...

Embodiment 2-21

[0088] Step 1-Step 4 are the same as in Example 1, except for the variables in Tables 1-3, other conditions are unchanged. In the table, the substitute for 4-methyl-2,6-bis(4,4,5,5-tetramethyl-1,3,2-dioxaborolane)aniline of Example 1 is designated A , the substitute for 4-trityl iodobenzene is denoted as B, the substitute for 4-methyl-2,6-bis[(4-trityl)phenyl]aniline is denoted as C, 2,3- The substitute of butanedione is recorded as D, the substitute of bis-[2,6-bis(4-trityl)phenyl-4-methylphenyl)butanedione-1,2-diimine Denoted as E, [(MeN^N)NiBr 2 The substitute is designated as F.

[0089] Table 1 Example 2-22 Step 2 Synthesis C reactant (reaction temperature: 90°C, reaction time: 24h)

[0090]

[0091]

[0092]

[0093]

[0094]

[0095]

[0096] Table 3 Example 2-22 Step 4 Synthesis of F reactants (reaction time: 24h, 25°C)

[0097]

[0098]

[0099]

[0100]

Embodiment 23-44

[0102] A 350 mL glass pressure reactor connected to a high pressure gas line was first vacuum dried at 90 °C for at least 1 h. Then adjust the reactor to 30°C, add 98 mL of toluene and 500 μmol of MMAO into the reactor under an inert atmosphere, and then dissolve 1 μmol of Ni catalyst in 2 mL of dichloromethane (or chloroform) and inject it into the polymerization system through a syringe middle. Under rapid stirring (over 750 rpm), ethylene was introduced and kept at 8 atm. After 10 minutes, the pressure reactor was emptied, and a large amount of ethanol (or methanol) solution with a concentration of 5 wt% hydrochloric acid was added to quench the polymerization reaction, filtered, and dried in a vacuum oven to constant weight.

[0103] Wherein, the structural general formula of nickel catalyst is shown in formula (II), R 2 =CH 3 , R 3 =R 4 =R 5 = Ph, R 1 , R 8 , R 9 See Table 4.

[0104] (R 1 , R 8 , R 9 ) The performance of the polyethylene obtained by catalyzi...

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Abstract

The invention relates to a class of large steric hindrance α-diimine ligands, a nickel catalyst and a preparation method and application thereof, belonging to the technical field of catalysts. It solves two problems existing in the α-diimine catalyst in the prior art: 1) the molecular weight of the obtained copolymer is very low, generally below 10,000; 2) the conditions are relatively harsh, usually requiring high temperature and high pressure. The nickel catalyst of the present invention has a structural formula as shown in formula (II). The nickel catalyst has super large axial steric hindrance, can effectively inhibit chain transfer, and has the advantage of high activity (up to 6.9×10 7 gmol ‑1 h ‑1 ), and can still maintain high activity at high temperatures, and also has excellent thermal stability, and ultra-high molecular weight functionalized polyolefin materials can be prepared at normal temperature and pressure.

Description

technical field [0001] The invention belongs to the technical field of catalysts, and in particular relates to a class of large steric hindered α-diimine ligands, nickel catalysts and their preparation methods and applications, and in particular to the application of the nickel catalysts in the synthesis of polar functionalized ultra-high molecular weight polyethylene . Background technique [0002] Since Karl Ziegler and Giulio Natta won the Nobel Prize for their great achievements in olefin coordination polymerization in the last century, the entire polyolefin industry has experienced extremely rapid development in the past half a century, whether in academia or industry, olefins Aggregation studies have all achieved great success. At present, due to its excellent performance and relatively low price, polyolefin materials have become the polymer materials with the largest output and widest uses in synthetic resins. [0003] Among polyolefin materials, polyethylene has ma...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C08F110/02C08F4/70C07C251/08C07C251/24C07C251/20C07C249/02
CPCC08F110/02C07C251/08C07C251/24C07C251/20C07C249/02C07C2603/20C07C2603/88C07C2602/42C08F4/7006C08F2500/01
Inventor 简忠保胡小强
Owner CHANGCHUN INST OF APPLIED CHEMISTRY - CHINESE ACAD OF SCI
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