Sandwich type large steric hindrance amine, neutral nickel catalyst, preparation method and application thereof in olefin polymerization

文档序号:547945 发布日期:2021-06-04 浏览:38次 中文

阅读说明:本技术 一类夹心型大位阻胺、中性镍催化剂、制备方法及其在烯烃聚合中的应用 (Sandwich type large steric hindrance amine, neutral nickel catalyst, preparation method and application thereof in olefin polymerization ) 是由 简忠保 王超群 于 2021-01-28 设计创作,主要内容包括:本发明提供一类夹心型大位阻胺、中性镍催化剂、制备方法及其在烯烃聚合中的应用,属于催化剂制备方法领域。该一类夹心型大位阻胺结构式如式(I)所示,中性镍催化剂结构式如式(Ⅱ)所示,该催化剂是将通式为式(I)的夹心型大位阻胺、通式为(c)的水杨醛骨架和催化剂在有机溶剂中反应,得到通式为(d)的配体;将通式为(d)的配体、(tmeda)NiMe-2和吡啶在有机溶剂中反应得到的。本发明还提供上述中性镍催化剂在烯烃聚合中的应用。本发明催化剂首次实现在130℃高温下高活性得到高分子量M-w达12.7万的聚乙烯。本发明获得的支化高分子量聚乙烯以及超高分子量聚乙烯科潜在用于航空航天、国防军工、民用、医疗等诸多领域。(The invention provides a sandwich type high steric hindrance amine and neutral nickel catalyst, a preparation method and application thereof in olefin polymerization, belonging to the field of catalyst preparation methods. The structural formula of the sandwich type high steric hindrance amine is shown as a formula (I), the structural formula of the neutral nickel catalyst is shown as a formula (II), and the catalyst is prepared by filling a sandwich with the general formula (I)Reacting the type large steric hindrance amine, the salicylaldehyde framework with the general formula (c) and a catalyst in an organic solvent to obtain a ligand with the general formula (d); ligand with general formula (d), (tmeda) NiMe 2 And pyridine in an organic solvent. The invention also provides the application of the neutral nickel catalyst in olefin polymerization. The catalyst of the invention realizes high activity at a high temperature of 130 ℃ for the first time to obtain high molecular weight M w Up to 12.7 million polyethylenes. The branched high molecular weight polyethylene and the ultrahigh molecular weight polyethylene obtained by the method are potentially used in the fields of aerospace, national defense and military industry, civil use, medical treatment and the like.)

1. A sandwich type large steric hindrance amine is characterized in that the structural formula is shown as the formula (I):

in the general formula (I): r3An alkyl group represented by H, C1 to C20,tBu、F、OCH3、CF3Or NO2

R4Representation O, S, N (CH)3)、CH=CH、CH2O、CH2S or (CH)2)nWherein n is 0, 1,2, 3;

R5h, a C1-C20 alkyl group,tBu、Ph、F、Cl、OCH3、CF3Or NO2

2. The sandwich-type sterically hindered amine according to claim 1, wherein the structural formula is as shown in formulae 1 to 60:

3. the method for preparing sandwich type large hindered amine according to claim 1, which comprises the following steps:

aniline with a general formula (a) and a compound with a general formula (b) are mixed, and then Lucas reagent is added for reaction to obtain sandwich type large steric hindrance amine with a general formula (I);

4. a neutral nickel catalyst is characterized in that the structural formula is shown as the formula (II):

in the general formula (II), R1An alkyl group having a carbon number of 1-20,tBu、、I、Br、Cl、F、OCH3、CF3、NO2Phenyl and its derivatives, naphthyl and its derivatives or anthryl and its derivatives;

R2an alkyl group represented by H, C1 to C20,tBu、、I、Br、Cl、F、OCH3、CF3Or NO2

R3An alkyl group represented by H, C1 to C20,tBu、F、OCH3、CF3Or NO2

R4Representation O, S, N (CH)3)、CH=CH、CH2O、CH2S or (CH)2)nWherein n is 0, 1,2, 3;

R5an alkyl group represented by H, C1 to C20,tBu、Ph、F、Cl、OCH3、CF3Or NO2

5. The neutral nickel catalyst of claim 4, wherein the structural formula is shown in formulas 1-64:

6. the method for preparing a neutral nickel catalyst of claim 4, comprising:

the method comprises the following steps: reacting sandwich type large steric hindrance amine with a general formula (I), a salicylaldehyde framework with a general formula (c) and a catalyst in an organic solvent to obtain a ligand with a general formula (d);

step two: ligand with general formula (d), (tmeda) NiMe2Reacting with pyridine in an organic solvent to obtain a neutral nickel catalyst shown in a formula (II);

7. the method for preparing neutral nickel catalysts according to claim 6, wherein the reaction temperature in the first step is above 70 ℃ and the reaction time is above 24 h.

8. The method for preparing a neutral nickel catalyst of claim 6, wherein the molar ratio of the salicylaldehyde skeleton represented by the general formula (c) to the sandwich type large hindered amine represented by the general formula (I) is 1: n, wherein N is more than or equal to 1.

9. The method of claim 6, wherein the ligand of formula (d) and (tmeda) NiMe are2The molar ratio is 1: n, wherein N is more than or equal to 1, and the quantity ratio of the ligand with the general formula (d) to the pyridine substance is 1: m, wherein M is more than or equal to 10.

10. Use of the neutral nickel catalyst of claim 4 in olefin polymerization.

Technical Field

The invention belongs to the field of catalyst preparation methods, and particularly relates to a sandwich type high-steric hindrance amine and neutral nickel catalyst, a preparation method and application thereof in olefin polymerization.

Background

The polyolefin material has low price and excellent comprehensive performance, is a high polymer material with the largest output and the widest application, and plays an important role in national economic development. Since Ziegler and Natta gained the nobel prize in 1963, the polyolefin field has had great success both in the academia and in the industry. The transition metal catalyzed olefin polymerization can customize the structure of polyolefin, synthesize high performance polyolefin materials with different performances and be applied to different fields. Therefore, the metal catalyst is the 'soul' of the polyolefin industry, and the updating of the catalyst technology brings about a huge breakthrough in the field. The nickel salicylaldiminate system has gained vigorous development since the first pioneering work in 1998-2000 by Grubbs published neutral nickel salicylaldiminate catalyzed olefin polymerization. Nickel salicylaldiminate catalysts have many advantages: (1) the catalyst is stable, the synthesis is convenient, the catalyst can catalyze the polymerization in a single component, a large amount of aluminum reagents or expensive boron salts are not needed for matching, the polymerization process is simplified, and the cost is reduced; (2) the active center is neutral, and the tolerance to polar functional groups is stronger; (3) in addition to the usual polymerization media toluene, hexane, the system can also be used in polar solvents such as Tetrahydrofuran (THF) and water to give polymers of high molecular weight. For many years, researchers have made a lot of work on structural optimization and mechanism research of nickel salicylaldiminate, but there is always a difficult-to-break bottleneck-high temperature performance (poor heat resistance and low polymer molecular weight), so that it is difficult for the catalyst to have multiple characteristics of high heat resistance, high activity and high molecular weight. The key scientific problem is that the nickel salicylaldiminate catalyst is very sensitive to temperature, the reported literature shows that the polymerization temperature is mostly less than 70 ℃, and the molecular weight is reduced along with the temperature change in a cliff-type manner, which is not beneficial to industrial application. In the invention, after a large steric hindrance rotation limitation strategy (CN202010391690.3) is proposed, a 'large steric hindrance rotation limitation + sandwich' strategy is developed, the lower part of the metal center is shielded and protected by a benzene ring, the upper part of the metal center is shielded and protected by a spatial repulsion effect of a bridging mode, the rotation of the benzene ring around a C-C single bond at high temperature is inhibited, the central metal is protected, and a single-component single-activity center salicylaldehyde imine nickel catalyst with high heat resistance, high activity and high molecular weight is constructed and used for ethylene polymerization. The high-activity salicylaldehyde imine nickel catalyst formed by the novel strategy can perform ethylene polymerization reaction with high molecular weight (hundreds of thousands) and moderate branching at high temperature (more than or equal to 130 ℃), and simultaneously can obtain ultrahigh molecular weight polyethylene (with the highest Mw reaching 602.0 ten thousands) at low temperature of 30-70 ℃.

At present, the nickel salicylaldimine catalyst has a difficult-to-break bottleneck-poor high-temperature performance (poor heat resistance and low polymer molecular weight), so that the catalyst is difficult to simultaneously have multiple characteristics of high heat resistance, high activity and high molecular weight. The gas phase polymerization temperature is usually in the range of 70 ℃ to 110 ℃ and thus prevents industrial application thereof.

Disclosure of Invention

The invention aims to provide a sandwich type high steric hindrance amine, a neutral nickel catalyst, a preparation method and an application thereof in olefin polymerization, wherein the nickel catalyst is used for ethylene polymerization, and ultra-high molecular weight polyethylene (Mw reaching 523.8 ten thousands) with ultra-low branching degree (Brs <0.1/1000C) is obtained with high activity under the condition of 40 ℃ and toluene solvent; ultra-high molecular weight polyethylene (Mw up to 602.0 ten thousand) with ultra-low branching degree (Brs ═ 0.5/1000C) is obtained with high activity under the condition of THF solvent at 50 ℃; under the condition of high temperature (>90 ℃), the catalyst can keep high activity and obtain high molecular weight (Mw: 12.7-100.2 ten thousand) polyethylene with adjustable branching degree (26-65).

The invention firstly provides sandwich type high steric hindrance amine, the structural formula is shown as the formula (I):

in the general formula (I): r3An alkyl group represented by H, C1 to C20,tBu、F、OCH3、CF3Or NO2

R4Representation O, S, N (CH)3)、CH=CH、CH2O、CH2S or (CH)2)nWherein n is 0, 1,2, 3;

R5an alkyl group having a carbon number of 1-20,tBu、Ph、F、Cl、OCH3、CF3Or NO2

The invention also provides a preparation method of the sandwich type large steric hindrance amine, which comprises the following steps:

aniline with a general formula (a) and a compound with a general formula (b) are mixed, and then Lucas reagent is added for reaction to obtain sandwich type large steric hindrance amine with a general formula (I);

the invention also provides a neutral nickel catalyst, the structural formula is shown as the formula (II):

in the general formula (II), R1An alkyl group having a carbon number of 1-20,tBu、、I、Br、Cl、F、OCH3、CF3、NO2Phenyl and its derivatives, naphthyl and its derivatives or anthryl and its derivatives;

R2an alkyl group represented by H, C1 to C20,tBu、、I、Br、Cl、F、OCH3、CF3Or NO2

R3An alkyl group represented by H, C1 to C20,tBu、F、OCH3、CF3Or NO2

R4Representation O, S, N (CH)3)、CH=CH、CH2O、CH2S or (CH)2)nWherein n is 0, 1,2, 3;

R5an alkyl group having a carbon number of 1-20,tBu、Ph、F、Cl、OCH3、CF3Or NO2

The invention also provides a preparation method of the neutral nickel catalyst, which comprises the following steps:

the method comprises the following steps: reacting sandwich type large steric hindrance amine with a general formula (I), a salicylaldehyde framework with a general formula (c) and a catalyst in an organic solvent to obtain a ligand with a general formula (d);

step two: ligand with general formula (d), (tmeda) NiMe2Reacting with pyridine in an organic solvent to obtain a neutral nickel catalyst shown in a formula (II);

the invention also provides the application of the neutral nickel catalyst in olefin polymerization.

The invention has the advantages of

The invention provides a sandwich type large steric hindrance amine, a neutral nickel catalyst, a preparation method and application thereof in olefin polymerization, wherein the sandwich type large steric hindrance amine is utilized to invent a single-component and single-activity center salicylaldehyde imine nickel catalyst with high heat resistance, high activity and high molecular weight characteristics, and the catalyst is used for ethylene high-activity high molecular weight polymerization, so that the continuous 1-hour polymerization of the catalyst at 110 ℃ is realized without inactivation, high molecular weight polyethylene (33.0 ten thousand) is obtained, the heat resistance of a salicylaldehyde imine nickel catalytic system is also improved, and the novel salicylaldehyde imine nickel catalyst synthesized by the invention shows excellent performance in the aspect of ethylene polymerization. Compared with all reported salicylaldehyde imine nickel catalysts in the literature, the catalyst of the invention realizes high activity at a high temperature of 130 ℃ to obtain high molecular weight (M) for the first timewUp to 12.7 ten thousand) polyethylene. Meanwhile, the molecular weight of the super-high molecular weight polyethylene prepared by polymerizing the salicylaldehyde imine nickel catalyst system reported in the prior literature in toluene is further improved to 523.8 ten thousand under the condition of 40 ℃, and the branching degree is extremely low (the catalyst is prepared by the method of (1)<1/1000C), fraction of polymer obtained by polymerization at 50 ℃ in THFThe quantum is greatly increased to MwUp to 602.0 ten thousand. The branched high molecular weight polyethylene and the ultrahigh molecular weight polyethylene obtained by the method are potentially used in the fields of aerospace, national defense and military industry, civil use, medical treatment and the like.

Drawings

FIG. 1 is a nuclear magnetic resonance hydrogen spectrum of a sandwich type sterically hindered amine compound C prepared in example 1 of the present invention;

FIG. 2 is a nuclear magnetic resonance hydrogen spectrum of sandwich type sterically hindered amine compound E prepared in example 2 of the present invention;

FIG. 3 is a nuclear magnetic resonance hydrogen spectrum of sandwich type sterically hindered amine compound G prepared in example 3 of the present invention;

FIG. 4 is a NMR spectrum of ligand I prepared in example 5 of the present invention;

FIG. 5 is a NMR chart of ligand J prepared in example 6 of the present invention;

FIG. 6 is a NMR chart of ligand K prepared in example 7 of the present invention;

FIG. 7 is a NMR chart of a neutral nickel catalyst L prepared in example 9 of the present invention;

FIG. 8 is a NMR chart of neutral nickel catalyst M prepared in example 10 of the present invention;

FIG. 9 is a NMR chart of neutral nickel catalyst N prepared in example 11 of the present invention;

FIG. 10 is a single crystal diffractogram of neutral nickel catalyst L prepared in example 9 of the present invention;

Detailed Description

The invention firstly provides sandwich type high steric hindrance amine, the structural formula is shown as the formula (I):

in the general formula (I), R3An alkyl group represented by H, C1 to C20,tBu (tert-butyl), F, OCH3、CF3Or NO2

R4Representation O, S, N (CH)3)、CH=CH、CH2O、CH2S or (CH)2)nWherein n is 0, 1,2, 3;

R5an alkyl group having a carbon number of 1-20,tBu (tert-butyl), Ph (phenyl), F, Cl, OCH3、CF3Or NO2

Further, in the above-mentioned case,

when R is3H or CH3In (para position), R4Representation O, S, N (CH)3)、CH=CH、CH2O、CH2S or (CH)2)nWherein n is 1, 3; r5An alkyl group represented by H, C1 to C20,tBu、Ph、F、Cl、OCH3、CF3Or NO2

When R is3=CH3(para) and R4=(CH2)nWhen (n is 0), R5An alkyl group having a carbon number of 2-20,tBu、Ph、Cl、CF3Or NO2

When R is3Represents CH3(meta-position, ortho-position), C2-C20 alkyl,tBu、F、OCH3、CF3Or NO2When R is4Representation O, S, N (CH)3)、CH=CH、CH2O、CH2S or (CH)2)nWherein n is 0, 1,2, 3; r5An alkyl group represented by H, C1 to C20,tBu、Ph、F、Cl、OCH3、CF3Or NO2

Preferably, the sandwich type large steric hindrance amine has a structural formula shown as formula 1-60:

the invention also provides a preparation method of the sandwich type large steric hindrance amine, which comprises the following steps:

mixing aniline of formula (a) and a compound of formula (b) in a molar ratio of aniline of formula (a) to compound of formula (b) of preferably 1:2, and then dissolving the mixture in liquid form by heating, preferably at 100 ℃ to 150 ℃, and then mixing the mixture in an amount ratio to the substance of formula (a) of 1: 0.5 adding Lucas reagent, completing dropwise adding, heating to 160-180 ℃, reacting for more than 1h, cooling to room temperature, dissolving with dichloromethane, sequentially washing with 1mol/L sodium hydroxide aqueous solution and deionized water for 3 times, drying with anhydrous sodium sulfate, and removing the solvent in vacuum to obtain the sandwich type high steric hindrance amine with the general formula (I); the Lucas reagent is preferably ZnCl2A hydrochloric acid solution; the reaction route is as follows:

the invention also provides a neutral nickel catalyst, the structural formula is shown as the formula (II):

in the general formula (II), R1An alkyl group having a carbon number of 1-20,tBu (tert-butyl), I, Br, Cl, F, OCH3、CF3、NO2(phenyl and its derivatives, R6=H、CH3tBu (tert-butyl), OCH3、CF3Or NO2(R6At meta-or para-),(naphthyl and its derivatives, R6=H、CH3tBu (tert-butyl), OCH3、CF3Or NO2)、(Anthracene radical and derivatives thereof, R6=H、CH3tBu (tert-butyl), OCH3、CF3Or NO2)、

R2An alkyl group represented by H, C1 to C20,tBu、、I、Br、Cl、F、OCH3、CF3Or NO2

R3An alkyl group represented by H, C1 to C20,tBu、F、OCH3、CF3Or NO2

R4Representation O, S, N (CH)3)、CH=CH、CH2O、CH2S or (CH)2)nWherein n is 0, 1,2, 3;

R5an alkyl group having a carbon number of 1-20,tBu、Ph、F、Cl、OCH3、CF3Or NO2

Preferably, the neutral nickel catalyst has a structural formula shown in formulas 1-64:

the invention also provides a preparation method of the neutral nickel catalyst, which comprises the following steps:

the method comprises the following steps: reacting sandwich type large steric hindrance amine with a general formula (I), a salicylaldehyde framework with a general formula (c) and a catalyst in an organic solvent, placing a reaction mixture in a sealed pressure-resistant bottle, wherein the reaction temperature is preferably more than 70 ℃, more preferably more than 100 ℃, and the reaction time is preferably more than 24 hours, more preferably 72 hours, so as to obtain a ligand with a general formula (d); the organic solvent is preferably methanol, and the catalyst is preferably p-toluenesulfonic acid monohydrate, formic acid or acetic acid; the molar ratio of the salicylaldehyde skeleton of the general formula (c) to the sandwich-type sterically bulky amine of the general formula (I) is 1: n (N is more than or equal to 1), preferably 1: 1.2; the reaction route is as follows:

step two: the ligand of the general formula (d) and (tmeda) NiMe2(tmeda ═ tetramethylethylenediamine) is added into an organic solvent, the organic solvent is preferably toluene, then pyridine is added for reaction, the reaction temperature is preferably room temperature, the reaction time is preferably more than 12h, more preferably 24h, the filtrate is collected by filtration, the filtrate is vacuumized and concentrated, the filtrate is dripped into the organic solvent (such as n-hexane and diethyl ether) for sedimentation, yellow solid is separated out, the yellow solid is filtered, the solid is collected and dried in vacuum, and the neutral nickel catalyst shown in the formula (II) is obtained; the ligand with the general formula (d) and (tmeda) NiMe2The (tmeda ═ tetramethylethylenediamine) molar ratio is preferably 1: n (N.gtoreq.1), more preferably 1: 1.2; the ratio of the amount of ligand of formula (d) to the amount of pyridine species is preferably 1: m (M.gtoreq.10), more preferably 1: 10. The reaction route is as follows:

the invention also provides the application of the neutral nickel catalyst in olefin polymerization.

The invention also provides a method for catalyzing polyethylene by using the neutral nickel catalyst, which comprises the following steps:

drying the reactor preferably at 90 ℃ for more than 1h, connecting the reactor with a high-pressure gas line, adjusting the temperature of the reactor to 40-130 ℃, adding a solvent into the reactor under an inert atmosphere, then dissolving a nickel catalyst in the solvent to obtain a catalyst solution, injecting the solvent, preferably toluene, into the reactor, stirring at a stirring speed of preferably more than 750 revolutions, introducing ethylene and keeping the pressure at 8-40bar, after reacting for 5-120min, evacuating the pressure reactor, adding ethanol to quench the polymerization reaction, filtering the polymer, and drying in a vacuum oven to obtain polyethylene.

The present invention is described in further detail below with reference to specific examples, in which the starting materials are all commercially available.

EXAMPLE 1 preparation of Sandwich-type sterically hindered Amines

A (6.8g, 32.3mmol) and B (4.0g, 16.2mmol) were placed in a 100mL flask, melted at 100 ℃ and ZnCl was added dropwise with stirring2Concentrated hydrochloric acid solution (ZnCl) of2: 1.1g, 8.1mmol, concentrated hydrochloric acid: 1.35mL, 16.2mmol), after the dropwise addition, heating to 160 ℃, stirring for reaction for 3 hours, stopping the reaction, cooling to room temperature, adding dichloromethane for dissolution, washing with NaOH aqueous solution for three times, washing with distilled water for three times, separating an organic layer, and adding anhydrous Na2SO4Drying and vacuum drying of the solvent gave product C (9.6g, 94.1% yield).

1H NMR(500MHz,298K,CDCl3,7.26ppm):δ=8.33(d,1H,aryl-H),7.42(d,2H,aryl-H),7.27(t,2H,aryl-H),7.15-7.06(m,9H,aryl-H),7.02(d,1H,aryl-H),6.99(s,2H,aryl-H),6.91(m,6H,aryl-H),5.74(s,1H,CHPh2),5.10(s,1H,CHPh2),4.01(s,2H,NH2),2.73(m,4H,CH2Ph),2.39(m,4H,CH2Ph),2.29(s,6H, Ph-Me). The nuclear magnetic hydrogen spectrum is shown in FIG. 1.

EXAMPLE 2 preparation of Sandwich-type sterically hindered Amines

A (4.0g, 19.0mmol) and D (3.4g, 9.5mmol) were placed in a 100mL flask, melted at 100 deg.C, and while stirring, concentrated hydrochloric acid solution of ZnCl2 (ZnCl 2: 0.65g, 4.8mmol, concentrated hydrochloric acid: 0.8mL, 9.5mmol) was added dropwise, after the addition was completed, the reaction was warmed to 160 deg.C, stirred for 3h, stopped, cooled to room temperature, dissolved by adding dichloromethane, washed three times with aqueous NaOH solution, washed three times with distilled water, the organic layer was separated, dried over anhydrous Na2SO4, and the solvent was dried under vacuum to give product E (6.0g, 85.3% yield).

1H NMR (500MHz,298K, CDCl3,7.26ppm): δ ═ 8.45(d,1H, aryl-H),7.85(s,1H, aryl-H),7.79(s,2H, aryl-H),7.44(d,2H, aryl-H),7.34(t,2H, aryl-H),7.27(d,2H, aryl-H),7.17-7.10(m,8H, aryl-H),7.07(m,2H, aryl-H),6.97-6.90(m,4H, aryl-H),5.77(s,1H, CH 2),5.12(s,1H, CHPh2),3.65(s,2H, NH2),2.73(m,4H, CH2Ph),2.41(m, 2 Ph). The nuclear magnetic hydrogen spectrum is shown in FIG. 2.

EXAMPLE 3 preparation of Sandwich-type sterically hindered Amines

F (3.1G, 16.9mmol) and D (3.0G, 8.4mmol) are placed in a 100mL flask, after melting at 90 ℃, concentrated hydrochloric acid solution of ZnCl2 (ZnCl 2: 0.57G, 4.2mmol, concentrated hydrochloric acid: 0.7mL, 8.4mmol) is added dropwise with stirring, after completion of the dropwise addition, the reaction is stopped by heating to 160 ℃, after stirring for 3 hours, cooling to room temperature, adding dichloromethane for dissolution, washing three times with NaOH aqueous solution, washing three times with distilled water, separating an organic layer, drying anhydrous Na2SO4, and vacuum drying the solvent to obtain a pure product G (5.6G, 96.6% yield).

1H NMR (500MHz,298K, CDCl3,7.26 ppm). delta. delta.8.04 (d,1H, aryl-H),7.92(s,2H, aryl-H),7.87(s,1H, aryl-H),7.35(t,1H, aryl-H),7.21-7.12(m,13H, aryl-H),6.98(m,8H, aryl-H),6.47(s,1H, aryl-H),6.12(s,1H, CHPh2),5.47(s,1H, CHPh2),3.40(s,2H, NH 2). The nuclear magnetic hydrogen spectrum is shown in FIG. 3.

Example 4

Table 1 shows the reaction conditions and yields of aniline of partial formula (I), prepared according to the procedures of examples 1-3, except that the functional groups are changed and the melting temperature is changed depending on the melting point of the starting alcohol, the reactants and conditions are unchanged.

TABLE 1

The molar ratios of reactant (a) and reactant (b) in table 1 are both 1: 2.

EXAMPLE 5 preparation of ligand of formula (d)

A suspension of H (0.6g, 2.0mmol), C (1.5g, 2.4mmol) and p-toluenesulfonic acid (20mg) in methanol (50mL) was sealed in a pressure bottle, stirred at 100 ℃ for reaction for 3d, filtered while hot, collected as a yellow-white solid, purified by column chromatography, and dried under vacuum to give product I as a bright yellow solid (1.3g, 72.2% yield).

1H NMR (500MHz,298K, CDCl3,7.26ppm): delta ═ 12.81(s,1H, OH),8.57(s,1H, aryl-H),8.45(d,1H, aryl-H),8.10(s,2H, aryl-H),7.81(d,2H, aryl-H),7.55(m,3H, aryl-H),7.39(t,2H, aryl-H),7.33(m,3H, aryl-H),7.24-7.01(m,10H, aryl-H),7.00-6.74(m,8H, aryl-H),6.68(s,2H, aryl-H),6.38(s,1H, aryl-H),5.88(s,1H, CH 2),5.45(s,2H, aryl-H), 2H, 2M, 2H, 2M, 3H, 2H, 3H, 2H, 3H, 1.74(s,3H, Ph-Me). The nuclear magnetic hydrogen spectrum is shown in FIG. 4.

EXAMPLE 6 preparation of ligands of formula (d)

A suspension of H (0.4g, 1.34mmol), E (1.2g, 1.6mmol) and p-toluenesulfonic acid (20mg) in methanol (50mL) was sealed in a pressure bottle, the reaction stirred at 100 ℃ for 3d, filtered while hot, and the off-white solid collected, washed three times with methanol, three times with hexane, and dried under vacuum to give product J as an off-white solid (1.08g, 79.4% yield).

1H NMR (500MHz,298K, CDCl3,7.26ppm): delta ═ 12.11(s,1H, OH),8.56(s,1H, aryl-H),8.53(d,1H, aryl-H),8.09(d,2H, aryl-H),7.76-7.60(m,4H, aryl-H),7.59-7.51(m,3H, aryl-H),7.45-7.29(m,7H, aryl-H),7.21(m,3H, aryl-H),7.16-7.05(m,6H, aryl-H),7.03-6.92(m,4H, aryl-H),6.91-6.80(m,3H, aryl-H),6.76(dd,1H, aryl-H),6.65(m,1H, 6.88H, 56.83, 6.8H, 6H, 6.7H, 36632H, 3663H, Ph (m, 362H, 3663H, 3638H, 3663, Ph, CH2Ph),2.36(m,2H, CH2Ph),2.12(m,2H, CH2 Ph). The nuclear magnetic hydrogen spectrum is shown in FIG. 5.

EXAMPLE 7 preparation of ligand of formula (d)

A suspension of H (0.5G, 1.68mmol), G (1.26G, 1.84mmol) and p-toluenesulfonic acid (20mg) in methanol (50mL) was sealed in a pressure bottle, stirred at 100 ℃ for reaction 3d, filtered while hot, collected as a yellow-white solid, washed three times with methanol and dried under vacuum to give product K as a yellow-white solid (1.2G, 75.0% yield).

1H NMR (500MHz,298K, CDCl3,7.26ppm): δ ═ 11.99(s,1H, OH),8.53(s,1H, aryl-H),8.13(d,1H, aryl-H),8.08(d,2H, aryl-H),7.63-7.37(m,10H, aryl-H),7.25-7.13(m,9H, aryl-H),7.04(m,10H, aryl-H),6.88(t,1H, aryl-H),6.78(d,4H, aryl-H),6.70(d,1H, aryl-H),6.68(s,1H, aryl-H),6.22(s,1H, CHPh2),5.58(s,1H, CHPh 2). The nuclear magnetic hydrogen spectrum is shown in FIG. 6.

Example 8

Table 2 shows the reaction conditions and yields of the ligands of partial formula (d), the detailed procedures refer to examples 5-7.

TABLE 2

The molar ratio of salicylaldehyde skeleton of formula (H) to aniline of formula (I) in Table 2 is 1: 1.2.

EXAMPLE 9 preparation of neutral Nickel catalyst

I (200mg, 0.22mmol) and (tmeda) NiMe2(67.42mg, 0.33mmol) were dissolved in 15ml of toluene, followed by addition of pyridine (174.0mg, 2.2mmol), reaction stirred at room temperature for 24 hours, collection of the filtrate by filtration, concentration of the filtrate under vacuum, precipitation into n-hexane dropwise, precipitation of a yellow solid, filtration, collection of the solid and drying under vacuum to give pure catalyst L (200mg, 85.8% yield).

1H NMR (500MHz,298K, CDCl3,7.26ppm): delta ═ 8.60(dd,1H, aryl-H),8.23(d,1H, aryl-H),8.18(m,4H, aryl-H),7.92(d,1H, aryl-H),7.88(d,1H, aryl-H),7.80-7.71(m,4H, aryl-H),7.61(s,1H, aryl-H),7.50(t,1H, aryl-H),7.42(d,1H, aryl-H),7.35(t,1H, aryl-H),7.25(d,1H, aryl-H),7.23(m,3H, aryl-H),7.13-7.03(m,8H, aryl-H), 7.00-6.00 (m,6H, 89H, 6-H), 2.57-H, 6-H, 2H, 6-H, aryl-H, 82 (m,2H, 6-H, 82, 2H, 1H, CHPh2),6.39(m,2H, aryl-H),6.31(t,1H, aryl-H),5.92(s,1H, CHPh2),5.64(t,2H, aryl-H),3.36(m,1H, CH2Ph),3.11(m,1H, CH2Ph),2.66(m,1H, CH2Ph),2.50(m,3H, CH2Ph),2.15(s,3H, Ph-Me),2.13(s,3H, Ph-Me),2.09(m,1H, CH2Ph), -0.98(s,3H, Ni-Me). The nuclear magnetic hydrogen spectrum is shown in FIG. 7. The single crystal diffraction pattern is shown in fig. 10.

EXAMPLE 10 preparation of neutral Nickel catalyst

J (300mg, 0.29mmol) and (tmeda) NiMe2(72.4mg, 0.353mmol) were dissolved in 15ml of toluene, followed by addition of pyridine (232.6mg, 2.94mmol), reaction at room temperature with stirring for over 24 hours, collection of the filtrate by filtration, concentration of the filtrate under vacuum, dropwise addition to n-hexane to precipitate a yellow solid, filtration, collection of the solid and vacuum drying to give pure catalyst M (310mg, 90.1% yield).

1H NMR (500MHz,298K, CDCl3,7.26ppm): delta ═ 8.77(s,1H, aryl-H),8.64(d,1H, aryl-H),8.17(s,2H, aryl-H),8.06(d,1H, aryl-H),7.99(s,2H, aryl-H),7.90(m,3H, aryl-H),7.72(d,1H, aryl-H),7.67(d,2H, aryl-H),7.64(s,1H, aryl-H),7.55(t,1H, aryl-H),7.43(t,2H, aryl-H),7.30-7.20(m,4H, aryl-H),7.13-6.99(m,8H, aryl-H),6.94(t,2H, aryl-H),6.79 (ddH, ddH-H, 2H, aryl-H, 79, aryl-H),6.55(d,1H, aryl-H),6.46(m,2H, aryl-H),6.34(m,2H, aryl-H),5.91(s,1H, CHPh2),5.70(t,2H, aryl-H),3.26(m,1H, CH2Ph),3.04(m,1H, CH2Ph),2.64(m,1H, CH2Ph),2.51(m,3H, CH2Ph),2.23(m,1H, CH2Ph),2.13(m,1H, CH2Ph), -1.03(s,3H, Ni-Me). The nuclear magnetic hydrogen spectrum is shown in FIG. 8.

EXAMPLE 11 preparation of neutral Nickel catalyst

K (250mg, 0.26mmol) and (tmeda) NiMe2(58.2mg, 0.28mmol) were dissolved in 15ml of toluene, followed by addition of pyridine (203.8mg, 2.94mmol), reaction at room temperature with stirring for over 24 hours, collection of the filtrate by filtration, concentration of the filtrate under vacuum, precipitation into N-hexane dropwise, precipitation of a yellow solid, filtration, collection of the solid and drying under vacuum to give pure catalyst N (250mg, 86.8% yield).

1H NMR (500MHz,298K, CDCl3,7.26ppm): delta-8.76 (s,1H, aryl-H),8.45(s,1H, aryl-H),8.20(d,1H, aryl-H),8.15(s,1H, aryl-H),8.04(d,1H, aryl-H),8.01(s,1H, aryl-H),7.88(dd,2H, aryl-H),7.73(d,1H, aryl-H),7.62-7.51(m,3H, aryl-H),7.40(t,1H, aryl-H),7.34(m,4H, aryl-H),7.15-7.08(m,6H, aryl-H),7.08-6.90(m,16H, aryl-H),6.67 (t, 6H-H, 357.84H), 7.42H, 18H, 6H-7.58H, 7.42H (t, 3H, 6H, 7.42H, aryl-H),5.60(t,2H, aryl-H), -0.76(s,3H, Ni-Me). The nuclear magnetic hydrogen spectrum is shown in FIG. 9.

Example 12

Table 3 shows the synthesis conditions and yields of part of the catalysts of general formula (II), the specific procedures being referred to in examples 9 to 11.

TABLE 3

In Table 3, the Ni sources are all (tmeda) NiMe2, the reaction temperature is 25 ℃, and the molar ratios of the ligand of the structural formula (d) and pyridine are all 1: 10.

EXAMPLE 13 use of the catalyst

A350 mL glass pressure reactor connected to a high pressure gas line was first dried under vacuum at 90 ℃ for at least 1 h. The reactor was then adjusted to 40 ℃, 98mL of toluene was added to the reactor under an inert atmosphere, and then 5 μmol of Ni catalyst was dissolved in 2mL of toluene and injected into the polymerization system through a syringe. Under rapid stirring (750 revolutions), ethylene was passed in and maintained at 8 bar. After 15min, the pressure reactor was evacuated, 200mL of ethanol was added to quench the polymerization, the polymer was filtered, and dried in a vacuum oven to constant weight. The effect of different nickel catalysts on ethylene polymerization is shown in table 4.

TABLE 4 Effect of different nickel catalysts (varying substituent R3) on ethylene polymerization

Reaction conditions are as follows: nickel catalyst (5 μmol), toluene (100mL), ethylene pressure (8bar), polymerization time (15min), polymerization temperature (40 ℃), all data being based at least on the results of two parallel experiments (unless otherwise stated). Activity: in units of 106g mol-1 h-1. Mw, Mw/Mn: weight average molecular weight, polymer dispersibility index, respectively, at 150 ℃ in 1,2, 4-trichlorobenzene, relative to polystyrene standards, determined by GPC. The degree of branching is the number of branches per 1000 carbons and is determined by nuclear magnetic resonance hydrogen spectroscopy.

Note: items 1 to 16: nickel catalyst (R)1R2=H,R4=CH2CH2,R5=H,R6=H)。

Table 4 illustrates: when the catalyst substituent R is controlled1、R2、R4、R5、R6Without changing, by changing the substituents R3In the case of the same polymerization conditions (time, temperature, pressure are the same), R3If it is an electron withdrawing group (CF)3、NO2F) is an electron donating group (CH) compared to it3、OCH3tBu) has higher activity, lower molecular weight, and lower branching;

when the catalyst substituent R is controlled1、R2、R4、R5、R6Without changing, by changing the substituents R3At the same position, R is equal under the same polymerization conditions (time, temperature, pressure are the same)3Possess higher activity, higher molecular weight and a comparable degree of branching at the para position compared to the meta position.

EXAMPLE 14 use of the catalyst

A350 mL glass pressure reactor connected to a high pressure gas line was first dried under vacuum at 90 ℃ for at least 1 h. The reactor was then adjusted to 40 ℃, 98mL of toluene was added to the reactor under an inert atmosphere, and then 5 μmol of Ni catalyst was dissolved in 2mL of toluene and injected into the polymerization system through a syringe. Under rapid stirring (750 revolutions), ethylene was passed in and maintained at 8 bar. After 15min, the pressure reactor was evacuated, 200mL of ethanol was added to quench the polymerization, the polymer was filtered, and dried in a vacuum oven to constant weight. The effect of different nickel catalysts on ethylene polymerization is shown in table 5.

TABLE 5 different Nickel catalysts (varying substituent R)1、R2、R6) Influence on ethylene polymerization

Reaction conditions are as follows: nickel catalyst (5 μmol), toluene (100mL), ethylene pressure (8bar), polymerization time (15min), polymerization temperature (40 ℃), all data being based at least on the results of two parallel experiments (unless otherwise stated). Activity: at 106g mol-1h-1Is a unit. Mw、Mw/Mn: weight average molecular weight, polymer dispersibility index, respectively, at 150 ℃ in 1,2, 4-trichlorobenzene, relative to polystyrene standards, determined by GPC. The degree of branching is the number of branches per 1000 carbons and is determined by nuclear magnetic resonance hydrogen spectroscopy.

Note: items 1 to 22: nickel catalyst (R)3=CF3,R4=CH2CH2,R5H); items 13 to 16: nickel catalyst (R)1) (ii) a Items 17 to 19: nickel catalyst (R)1) (ii) a Items 20 to 22: nickel catalyst (R)1)。

Table 5 illustrates: when the catalyst substituent R is controlled3、R4、R5Without changing, by changing the substituents R1And R2In the case of the same polymerization conditions (time, temperature, pressure are the same), R1And R2By conversion to small radicals (CH)3tBu、I、CF3、NO2) The activity and molecular weight are reduced and the degree of branching is increased, in which R1And R2If it is an electron withdrawing group (I, CF)3、NO2) Compared with that ofElectron donating group (CH)3tBu) have higher molecular weights; when R is2Invariable, R1By substitution into a bulky radical with R1The increase of the group volume, the increase of the activity and the gradual increase of the molecular weight are caused by the large group volume in the catalyst, the central metal is protected, and the catalyst is not easy to generate beta-H elimination to deactivate the catalyst. When the catalyst substituent R is controlled1、R2、R3、R4、R5Without changing, by changing the substituents R6In the case of the same polymerization conditions (time, temperature, pressure are the same), R6If it is an electron withdrawing group (CF)3) Compared with it being an electron donating group (CH)3) Having a higher molecular weight and a lower degree of branching, R6In the meta position, it is less reactive than in the para position, but has a higher molecular weight and the electronic effect is more influential when the substituent is in the meta position than in the para position.

Example 15

A350 mL glass pressure reactor connected to a high pressure gas line was first dried under vacuum at 90 ℃ for at least 1 h. The reactor was then adjusted to 40 ℃, 98mL of toluene was added to the reactor under an inert atmosphere, and then 5 μmol of Ni catalyst was dissolved in 2mL of toluene and injected into the polymerization system through a syringe. Under rapid stirring (750 revolutions), ethylene was passed in and maintained at 8 bar. After 15min, the pressure reactor was evacuated, 200mL of ethanol was added to quench the polymerization, the polymer was filtered, and dried in a vacuum oven to constant weight. The effect of different nickel catalysts on ethylene polymerization is shown in table 6.

TABLE 6 different Nickel catalysts (varying substituent R)4、R5) Influence on ethylene polymerization

Reaction conditions are as follows: nickel catalyst (5 μmol), toluene (100mL), ethylene pressure (8bar), polymerization time (15min), polymerization temperature (40 ℃), all data being based at least on the results of two parallel experiments (unless otherwise stated). Activity: at 106g mol-1h-1Is a unit. Mw、Mw/Mn: weight average molecular weight, polymer dispersibility index, respectively, at 150 ℃ in 1,2, 4-trichlorobenzene, relative to polystyrene standards, determined by GPC. The degree of branching is the number of branches per 1000 carbons and is determined by nuclear magnetic resonance hydrogen spectroscopy.

Note: items 1 to 15: nickel catalyst (R)1R2=H,R3=CF3,R6=H)。

Table 6 illustrates: when the catalyst substituent R is controlled1、R2、R3、R5、R6Without changing, by changing the substituents R4In the case of the same polymerization conditions (time, temperature, pressure are the same), with R4Group CH2The number of bridges is increased, the activity and molecular weight are increased when R4The group being a heteroatom or a heteroatom group (O, S, N (CH)3) In particular, the activity and molecular weight are reduced, and the degree of branching is increased. When the catalyst substituent R is controlled1、R2、R3、R4、R6Without changing, by changing the substituents R5In the case of the same polymerization conditions (time, temperature, pressure are the same), R5If it is an electron withdrawing group (F, CF)3) Compared with it being an electron donating group (CH)3) The reactivity is slightly reduced, but there is a higher molecular weight and a lower degree of branching, and the electronic effect is more influential when the substituent is in the meta position than in the para position.

EXAMPLE 16 use of the catalyst

First, a 350mL glass pressure reactor or a 200mL steel kettle reactor, connected to a high pressure gas line, was dried under vacuum at 90 ℃ for at least 1 h. The reactor was then adjusted to the desired temperature, 98mL of solvent was added to the reactor under an inert atmosphere, and then a specific amount of Ni catalyst was dissolved in 2mL of the same solvent and injected into the polymerization system by syringe. Under rapid stirring (750 revolutions), ethylene was passed in and maintained at the desired pressure. After a certain time, the pressure reactor was evacuated, 200mL of ethanol was added to quench the polymerization, the polymer was filtered and dried in a vacuum oven to constant weight. The effect of different reaction conditions on the nickel salicylaldimine catalyst for the polymerization of ethylene is shown in table 7.

TABLE 7 Effect of reaction conditions on Nickel salicylaldiminate catalysts for ethylene polymerization

Reaction conditions are as follows: nickel catalyst (R)1R2=H,R3=CF3,R4=(CH2)2,R5=H,R6H), all data are based on at least the results of two parallel experiments (unless otherwise stated). Pressure: taking bar as a unit; time: taking min as a unit; temperature: in units of ℃ C; activity of 106g mol-1h-1Is a unit. Mw、Mw/Mn: weight average molecular weight, polymer dispersibility index, respectively, at 150 ℃ in 1,2, 4-trichlorobenzene, relative to polystyrene standards, determined by GPC. The degree of branching is the number of branches per 1000 carbons, as determined by nuclear magnetic resonance hydrogen spectroscopy.

Note: entries 1 to 4: the dosage of the nickel catalyst is 2 mu mol; items 5-11, 15-22, 25-30: the dosage of the nickel catalyst is 1 mu mol; items 12-14, 23-24: the amount of nickel catalyst used was 3. mu. mol.

Table 7 illustrates: control of nickel catalyst1R2=H,R3=H,R4=(CH2)2,R5=CH3,R6H), polymerization in toluene at constant temperature (40 ℃ C.), maintaining the ethylene pressure constant (8bar), the polymerization activity and the molecular weight of the polymer gradually increasing with time,is a living polymerization. Polymerization in THF was carried out while keeping the ethylene pressure constant (40bar), and the polymerization activity and the molecular weight of the polymer gradually increased with the lapse of time, and the polymerization was also living. When the ethylene pressure is 40bar, the polymerization time is 30min, the polymerization temperature is from 30 ℃ to 130 ℃, the molecular weight and the activity are firstly increased and then reduced, and the branching degree is increased; when the ethylene pressure is kept constant (40bar), the polymerization time is 120min, the temperature is 30 ℃, 40 ℃ and 50 ℃, the polymerization activity is gradually increased, the molecular weight is increased and then decreased, and the highest molecular weight (M) in the toluene polymerization is obtained at 40 DEG Cw523.8 ten thousand); when THF is used as a polymerization solvent, the polymerization time is 30min, and the ethylene pressure is 40bar, the polymerization activity and the polymer molecular weight are increased and then reduced along with the increase of the temperature, the activity and the molecular weight are highest at 60 ℃, and the branching degree is increased along with the increase of the temperature; the molecular weight is highest (M) at 50 ℃ when the temperature is 50 ℃ and 60 ℃ and the reaction time is 120minw602.0 ten thousand); when hexane, acetone, ethyl acetate and water are used as solvents, polymerization activity is reduced, the molecular weight of the polymer is reduced, and the degree of branching is increased.

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