阅读说明：本技术 一种对位苯氧基取代的α-二亚胺铁催化剂及其制备方法 (Para-phenoxy substituted alpha-diimine iron catalyst and preparation method thereof ) 是由 吴军化 于 2021-01-22 设计创作，主要内容包括：本发明提供一种对位苯氧基取代的α-二亚胺铁催化剂及其制备方法；该对位苯氧基取代的α-二亚胺铁催化剂由α-二亚胺配体与FeCl-2发生配位反应制得,α-二亚胺配体的对位上含有苯氧基,苯氧基与苯环具有共轭效应,使铁金属中心的电子云密度发生变化,可以催化苯乙烯和降冰片烯共聚,本发明设计的对位苯氧基取代的α-二亚胺铁催化剂在聚合温度在80℃时,聚合活性仍然可以达到10～6g/(mol·h)以上,较高的耐热性有利于工业化应用。(The invention provides a para-phenoxy substituted alpha-diimine iron catalyst and a preparation method thereof; the para-phenoxy substituted alpha-diimine iron catalyst is prepared from alpha-diimine ligand and FeCl 2 The alpha-diimine ligand is prepared by coordination reaction, the para-position of the alpha-diimine ligand contains phenoxy, the phenoxy and a benzene ring have a conjugate effect, so that the electron cloud density of an iron metal center is changed, and the alpha-diimine iron catalyst can catalyze the copolymerization of styrene and norbornene, and the polymerization activity of the para-position phenoxy substituted alpha-diimine iron catalyst can still reach 10 at the polymerization temperature of 80 DEG C 6 g/(mol · h) or more, and higher heat resistance is favorable for industrial application.)

1. A para-phenoxy substituted iron alpha-diimine catalyst, characterized in that: the structural formula of the para-phenoxy substituted alpha-diimine iron catalyst is as follows:

。

2. the method of claim 1 for preparing a para-phenoxy substituted iron alpha-diimine catalyst comprising: the method comprises the following steps:

s1: preparation of para-phenoxy substituted α -diimine ligands:

adding 4-phenoxyaniline and diketone into a flask with a branch mouth by taking anhydrous methanol as a solvent and formic acid as a catalyst, carrying out reflux reaction for 12-24 h, filtering after the reaction is finished, and adding the obtained crude product into CH₃OH/CH₂Cl₂Recrystallizing in mixed solvent of (1), filtering and washing with cold ethanol, and filteringDrying in air to obtain para-phenoxy substituted alpha-diimine ligand;

s2: preparation of para-phenoxy substituted alpha-diimine iron catalyst:

in N₂Protecting, reacting para-phenoxy substituted alpha-diimine ligand with FeCl₂Adding into a flask with a branch mouth, adding solvent CH₂Cl₂Stirring at room temperature for 12-24 h, filtering the mixed solution, removing the solvent from the obtained liquid by rotary evaporation, washing the obtained solid with diethyl ether, and finally drying in vacuum to obtain the para-phenoxy substituted alpha-diimine iron catalyst.

3. The method of claim 2, wherein the iron catalyst is selected from the group consisting of: in step S1, the diketone has the following structural formula:

。

4. the method of claim 2, wherein the iron catalyst is selected from the group consisting of: in step S1, the amount of formic acid is 1-10% of the mass of 4-phenoxyaniline.

5. The method of claim 2, wherein the iron catalyst is selected from the group consisting of: in the step S1, the molar ratio of the 4-phenoxyaniline to the diketone is 2: 1-2.5: 1.

6. The method of claim 2, wherein the iron catalyst is selected from the group consisting of: in step S1, the temperature of the reflux reaction is 25-60 ℃.

7. The method of claim 2, wherein the iron catalyst is selected from the group consisting of: in step S2, stepThe para-phenoxy substituted alpha-diimine ligand and FeCl₂The molar ratio of (a) to (b) is 1:1 to 1: 2.

8. A para-phenoxy substituted iron alpha-diimine catalyst in accordance with claim 1 wherein: the alpha-diimine iron catalyst is used for catalyzing the copolymerization reaction of norbornene and styrene, and the specific process comprises the following steps: a250 mL polymerization flask with a magnetic stirrer was cyclically replaced with vacuum-nitrogen three times in N₂Adding toluene solution, adding norbornene, styrene and MAO under the atmosphere, adding dichloromethane solution of catalyst by using an injector, reacting under rapid stirring, and evaporating the solvent after the reaction is finished to obtain the polymer.

9. A para-phenoxy substituted iron alpha-diimine catalyst in accordance with claim 8, wherein: in the polymerization reaction, the using amount of norbornene is 1-5 g, the using amount of styrene is 1-5 g, the using amount of a catalyst is 1-10 mu mol, the reaction temperature is controlled at 20-80 ℃, the reaction time is 60-360 min, the main catalyst is a para-phenoxy substituted alpha-diimine iron catalyst, the cocatalyst is MAO, and the molar ratio of the cocatalyst to the main catalyst is 600-1000: 1.

Technical Field

The invention belongs to the field of olefin catalytic polymerization, and particularly relates to a para-phenoxy substituted alpha-diimine iron catalyst and a preparation method thereof.

Background

Polynorbornene is a special polymer, has excellent mechanical property, heat resistance, solubility in organic solvent and transparency, and can be used for 193nm ultraviolet lithography. The main disadvantages of this material are brittleness, poor adhesion and low molecular weight, which generally increase the cohesiveness and solubility of the polymer by copolymerization with other materials and decrease the absorbance of the material itself.

The prior preparation methods of norbornene copolymer mainly comprise methods of free radical, active free radical, metal catalyst and the like. Norbornene, tetrafluoroethylene, styrene and acrylate are quaternary copolymerized by a radical method as in a.e.feiring and q.feng, and the norbornene and styrene copolymer photolithographic materials disclosed in Polymers vol.6(2014) are synthesized by a radical method.

The existing synthesis methods have the defects of long reaction time, low copolymer yield, small copolymer molecular weight, low copolymer alternation degree and the like, and therefore, the invention provides the para-phenoxy substituted alpha-diimine iron catalyst which is applied to the copolymerization reaction of norbornene and styrene.

Disclosure of Invention

In order to overcome the defects in the prior art, the para-phenoxy substituted alpha-diimine iron catalyst and the preparation method thereof are provided, and the catalyst can catalyze the copolymerization of norbornene and styrene to obtain the norbornene and styrene copolymer with high molecular weight and high copolymer alternation degree.

In order to achieve the above object, the present invention provides a para-phenoxy substituted α -iron diimine catalyst, wherein the structural formula of the α -iron diimine catalyst is:

a preparation method of a para-phenoxy substituted alpha-diimine iron catalyst comprises the following steps:

s1: preparation of para-phenoxy substituted α -diimine ligands:

adding 4-phenoxyaniline and diketone into a flask with a branch mouth by taking anhydrous methanol as a solvent and formic acid as a catalyst, carrying out reflux reaction for 12-24 h, filtering after the reaction is finished, and adding the obtained crude product into CH₃OH/CH₂Cl₂Recrystallizing in the mixed solvent, filtering, washing with cold ethanol, and vacuum drying to obtain the para-phenoxy substituted alpha-diimine ligand.

S2: preparation of para-phenoxy substituted alpha-diimine iron catalyst:

in N₂Protecting, reacting para-phenoxy substituted alpha-diimine ligand with FeCl₂Adding into a flask with a branch mouth, adding solvent CH₂Cl₂Stirring at room temperature for 12-24 h, filtering the mixed solution, and removing the obtained liquid by rotary evaporationSolvent, washing the obtained solid with ether, and finally drying in vacuum to obtain the para-phenoxy substituted alpha-diimine iron catalyst.

The reaction route of the specific synthesis steps of the reaction is as follows:

further, in step S1, the diketone has the following structural formula:

further, in step S1, the amount of formic acid is 1% to 10% of the mass of the 4-phenoxyaniline.

Further, in step S1, the molar ratio of the 4-phenoxyaniline to the diketone is 2:1 to 2.5: 1.

Further, in step S1, the temperature of the reflux reaction is 25 to 60 ℃.

Further, in step S2, the p-phenoxy substituted alpha-diimine ligand and FeCl₂The molar ratio of (a) to (b) is 1:1 to 1: 2.

Further, the alpha-ferrous diimine catalyst is used for catalyzing the copolymerization reaction of norbornene and styrene, and the specific process comprises the following steps: a250 mL polymerization flask with a magnetic stirrer was cyclically replaced with vacuum-nitrogen three times in N₂Adding toluene solution, adding norbornene, styrene and MAO under the atmosphere, adding dichloromethane solution of catalyst by using an injector, reacting under rapid stirring, and evaporating the solvent after the reaction is finished to obtain the polymer.

Further, the amount of norbornene used in the polymerization reaction is 1-5 g, the amount of styrene used is 1-5 g, the amount of catalyst used is 1-10 μmol, the reaction temperature is controlled at 20-80 ℃, the reaction time is 60-360 min, and the molar ratio of the co-catalyst to the main catalyst is 600-1000: 1.

Compared with the prior art, the invention has the following beneficial effects:

1. the para-position of the alpha-diimine ligand of the alpha-diimine iron catalyst prepared by the invention contains phenoxy, and the phenoxy and a benzene ring have a conjugated effect, so that the iron metal center is obtainedThe density of electron cloud is changed, the copolymerization of styrene and norbornene can be catalyzed, and the polymerization activity of the para-phenoxy substituted alpha-diimine iron catalyst designed by the invention can still reach 10 at the polymerization temperature of 80 DEG C⁶g/(mol · h) or more, and higher heat resistance is favorable for industrial application.

2. The alpha-diimine iron catalyst prepared by the invention is applied to copolymerization of styrene and norbornene, can perfectly replace a free radical polymerization catalyst, reduces the process cost, has mild reaction conditions, does not need to be carried out under harsh anhydrous and anaerobic conditions, greatly reduces the process difficulty, and obtains the norbornene and styrene copolymer with high molecular weight and high copolymer alternation degree.

Drawings

FIG. 1 is a single crystal diffractogram of an alpha-diimine iron catalyst.

Detailed Description

The invention will be further elucidated with reference to the following specific examples.

Example 1

This example is a specific procedure for the preparation of a para-phenoxy substituted iron alpha-diimine catalyst as follows:

s1: synthesis of α -diimine ligand:

dissolving 4-phenoxyaniline (20mmol) and diketone (10mmol) in 30mL of anhydrous methanol, adding 0.25g of formic acid while stirring, refluxing at 45 ℃ for 16h, removing the solvent to obtain a crude product, and adding CH₃OH/CH₂Cl₂(v/v ═ 15:1) mixed solvent was recrystallized, and a solid precipitate was precipitated, filtered and dried to obtain an α -diimine ligand in a yield of 83.4%.

The reaction formula is as follows:

s2: synthesis of alpha-iron diimine catalyst:

in N₂To a 100mL dry flask was added alpha-diimine ligand (6mmol) and FeCl, with protection₂(5mmol) and 30mL CH₂Cl₂The reaction was stirred at room temperature for 24h, the suspension was filtered, the mixture was filtered, the resulting liquid was freed from the solvent in vacuo, the resulting solid was washed three times with diethyl ether (3X 30mL) and finally dried in vacuo to give the solid iron alpha-diimine catalyst in 82.3% yield.

The reaction formula is as follows:

example 2

Warp direction N₂After three times of displacement, N is recharged at 1atm₂Adding 50mL of anhydrous toluene into a 250mL flask with a branch opening, heating and keeping the temperature constant to 20 ℃, respectively adding 1g of norbornene, 1g of styrene, 5 mu mol of the alpha-diimine iron catalyst obtained in example 1 dissolved in dichloromethane and 1mol/L of cocatalyst MAO (the molar ratio of the cocatalyst to the main catalyst is 1000:1), polymerizing for 1h, then adding 10mL of acidified ethanol with the volume percentage concentration of 10% until the reaction is ended, filtering out the polymer, washing with water and ethanol, and drying in a vacuum drying oven at 60 ℃ for 8h to obtain the polymer Mw of 2.5 x 10⁶g/mol, MWD of 2.1,¹³the norbornene content of the polymer was 61% by C NMR.

Example 3

Warp direction N₂After three times of displacement, N is recharged at 1atm₂Adding 50mL of anhydrous toluene into a 250mL flask with a branch opening, heating and keeping the temperature constant to 40 ℃, respectively adding 1g of norbornene, 1g of styrene, 5 mu mol of the alpha-diimine iron catalyst obtained in example 1 dissolved in dichloromethane and 1mol/L of cocatalyst MAO (the molar ratio of the cocatalyst to the main catalyst is 1000:1), polymerizing for 1h, then adding 10mL of acidified ethanol with the volume percentage concentration of 10% until the reaction is ended, filtering out the polymer, washing with water and ethanol, and drying in a vacuum drying oven at 60 ℃ for 8h to obtain the polymer Mw of 2.1 x 10⁶g/mol, MWD of 2.3,¹³the norbornene content of the polymer was determined to be 64% by C NMR.

Example 4

Warp direction N₂After three times of displacement, N is recharged at 1atm₂Adding 50mL of anhydrous toluene into a 250mL flask with a branch opening, heating and keeping the temperature to 60 ℃, respectively adding 1g of norbornene, 1g of styrene, 5 mu mol of the alpha-diimine iron catalyst obtained in example 1 dissolved in dichloromethane and 1mol/L of cocatalyst MAO (the molar ratio of the cocatalyst to the main catalyst is 1000:1), polymerizing for 1h, then adding 10mL of acidified ethanol with the volume percentage concentration of 10% until the reaction is ended, filtering out the polymer, washing with water and ethanol, and drying in a vacuum drying oven at 60 ℃ for 8h to obtain the polymer Mw of 1.9 x 10⁶g/mol, MWD of 2.5,¹³the norbornene content of the polymer was determined to be 67% by C NMR.

Example 5

Warp direction N₂After three times of displacement, N is recharged at 1atm₂Adding 50mL of anhydrous toluene into a 250mL flask with a branch opening, heating and keeping the temperature constant to 80 ℃, respectively adding 1g of norbornene, 1g of styrene, 5 mu mol of the alpha-diimine iron catalyst obtained in example 1 dissolved in dichloromethane and 1mol/L of cocatalyst MAO (the molar ratio of the cocatalyst to the main catalyst is 1000:1), polymerizing for 1h, then adding 10mL of acidified ethanol with the volume percentage concentration of 10% until the reaction is ended, filtering out the polymer, washing with water and ethanol, and drying in a vacuum drying oven at 60 ℃ for 8h to obtain the polymer Mw of 1.5 x 10⁶g/mol, MWD of 2.8,¹³the norbornene content of the polymer was 69% by C NMR.

Example 6

Warp direction N₂After three times of displacement, N is recharged at 1atm₂Adding 50mL of anhydrous toluene into a 250mL flask with a branch opening, heating and keeping the temperature constant to 20 ℃, respectively adding 1g of norbornene, 1g of styrene, 5 mu mol of the alpha-diimine iron catalyst obtained in example 1 dissolved in dichloromethane and 1mol/L of cocatalyst MAO (the molar ratio of the cocatalyst to the main catalyst is 800:1), polymerizing for 1h, then adding 10mL of acidified ethanol with the volume percentage concentration of 10% until the reaction is ended, filtering out the polymer, washing with water and ethanol, and drying in a vacuum drying oven at 60 ℃ for 8h to obtain the polymer Mw of 2.0X 10⁶g/mol，MWThe content of D is 2.3,¹³the norbornene content of the polymer was 63% by C NMR.

Example 7

Warp direction N₂After three times of displacement, N is recharged at 1atm₂Adding 50mL of anhydrous toluene into a 250mL flask with a branch opening, heating and keeping the temperature constant to 40 ℃, respectively adding 1g of norbornene, 1g of styrene, 5 mu mol of the alpha-diimine iron catalyst obtained in example 1 dissolved in dichloromethane and 1mol/L of cocatalyst MAO (the molar ratio of the cocatalyst to the main catalyst is 800:1), polymerizing for 1h, then adding 10mL of acidified ethanol with the volume percentage concentration of 10% until the reaction is ended, filtering out the polymer, washing with water and ethanol, and drying in a vacuum drying oven at 60 ℃ for 8h to obtain the polymer Mw of 1.8 x 10⁶g/mol, MWD of 2.5,¹³the norbornene content of the polymer was determined to be 64% by C NMR.

Example 8

Warp direction N₂After three times of displacement, N is recharged at 1atm₂Adding 50mL of anhydrous toluene into a 250mL flask with a branch opening, heating and keeping the temperature to 60 ℃, respectively adding 1g of norbornene, 1g of styrene, 5 mu mol of the alpha-diimine iron catalyst obtained in example 1 dissolved in dichloromethane and 1mol/L of cocatalyst MAO (the molar ratio of the cocatalyst to the main catalyst is 800:1), polymerizing for 1h, then adding 10mL of acidified ethanol with the volume percentage concentration of 10% until the reaction is ended, filtering out the polymer, washing with water and ethanol, and drying in a vacuum drying oven at 60 ℃ for 8h to obtain the polymer Mw of 1.7 x 10⁶g/mol, MWD of 2.6,¹³the norbornene content of the polymer was 69% by C NMR.

Example 9

Warp direction N₂After three times of displacement, N is recharged at 1atm₂Adding 50mL of anhydrous toluene into a 250mL flask with a branch opening, heating and keeping the temperature constant to 80 ℃, respectively adding 1g of norbornene, 1g of styrene, 5 mu mol of alpha-iron diimine catalyst obtained in example 1 dissolved in dichloromethane and 1mol/L of cocatalyst MAO (the molar ratio of the cocatalyst to the main catalyst is 800:1), polymerizing for 1h, then adding 10mL of acidified ethanol with the volume percentage concentration of 10% until the reaction is ended, filtering and filteringThe polymer was washed with water and ethanol, and then dried in a vacuum oven at 60 ℃ for 8 hours to give a polymer Mw of 1.4X 10⁶g/mol, MWD of 2.9,¹³the norbornene content of the polymer was 71% by C NMR.

Example 10

Warp direction N₂After three times of displacement, N is recharged at 1atm₂Adding 50mL of anhydrous toluene into a 250mL flask with a branch opening, heating and keeping the temperature constant to 20 ℃, respectively adding 1g of norbornene, 1g of styrene, 5 mu mol of the alpha-diimine iron catalyst obtained in example 1 dissolved in dichloromethane and 1mol/L of cocatalyst MAO (the molar ratio of the cocatalyst to the main catalyst is 600:1), polymerizing for 1h, then adding 10mL of acidified ethanol with the volume percentage concentration of 10% until the reaction is ended, filtering out the polymer, washing with water and ethanol, and drying in a vacuum drying oven at 60 ℃ for 8h to obtain the polymer Mw of 1.9 x 10⁶g/mol, MWD of 2.4,¹³the norbornene content of the polymer was determined to be 64% by C NMR.

Example 11

Warp direction N₂After three times of displacement, N is recharged at 1atm₂Adding 50mL of anhydrous toluene into a 250mL flask with a branch opening, heating and keeping the temperature constant to 40 ℃, respectively adding 1g of norbornene, 1g of styrene, 5 mu mol of the alpha-diimine iron catalyst obtained in example 1 dissolved in dichloromethane and 1mol/L of cocatalyst MAO (the molar ratio of the cocatalyst to the main catalyst is 600:1), polymerizing for 1h, then adding 10mL of acidified ethanol with the volume percentage concentration of 10% until the reaction is ended, filtering out the polymer, washing with water and ethanol, and drying in a vacuum drying oven at 60 ℃ for 8h to obtain the polymer Mw of 1.6 x 10⁶g/mol, MWD of 2.7,¹³the norbornene content of the polymer was determined to be 67% by C NMR.

Example 12

Warp direction N₂After three times of displacement, N is recharged at 1atm₂Into a 250mL branched flask, 50mL of anhydrous toluene was added, heated and maintained at a constant temperature of 60 ℃, and 1g of norbornene, 1g of styrene, 5. mu. mol of the iron α -diimine catalyst obtained in example 1 dissolved in methylene chloride, and 1mol/L of co-catalyst MAO (co-catalyst and main catalyst) were addedThe molar ratio of the catalyst is 600:1), the polymerization time is 1h, then 10mL of acidified ethanol with the volume percentage concentration of 10% is added until the reaction is ended, the polymer is filtered, washed by water and ethanol and then dried in a vacuum drying oven at 60 ℃ for 8h, and the Mw of the polymer is 1.5 multiplied by 10⁶g/mol, MWD of 2.8,¹³the norbornene content of the polymer was determined to be 70% by C NMR.

Example 13

Warp direction N₂After three times of displacement, N is recharged at 1atm₂Adding 50mL of anhydrous toluene into a 250mL flask with a branch opening, heating and keeping the temperature constant to 80 ℃, respectively adding 1g of norbornene, 1g of styrene, 5 mu mol of the alpha-diimine iron catalyst obtained in example 1 dissolved in dichloromethane and 1mol/L of cocatalyst MAO (the molar ratio of the cocatalyst to the main catalyst is 1000:1), polymerizing for 1h, then adding 10mL of acidified ethanol with the volume percentage concentration of 10% until the reaction is ended, filtering out the polymer, washing with water and ethanol, and drying in a vacuum drying oven at 60 ℃ for 8h to obtain the polymer Mw of 1.3X 10⁶g/mol, MWD of 3.0,¹³the norbornene content of the polymer was 72% by C NMR.

Example 14

Warp direction N₂After three times of displacement, N is recharged at 1atm₂Adding 50mL of anhydrous toluene into a 250mL flask with a branch opening, heating and keeping the temperature constant to 80 ℃, respectively adding 1g of norbornene, 1g of styrene, 5 mu mol of the alpha-diimine iron catalyst obtained in example 1 dissolved in dichloromethane and 1mol/L of cocatalyst MAO (the molar ratio of the cocatalyst to the main catalyst is 1000:1), polymerizing for 2h, then adding 10mL of acidified ethanol with the volume percentage concentration of 10% until the reaction is ended, filtering out the polymer, washing with water and ethanol, and drying in a vacuum drying oven at 60 ℃ for 8h to obtain the polymer Mw of 1.3X 10⁶g/mol, MWD of 3.1,¹³the norbornene content of the polymer was determined to be 70% by C NMR.

Example 15

Warp direction N₂After three times of displacement, N is recharged at 1atm₂Adding 50mL of anhydrous toluene into a 250mL flask with one opening, heating, keeping the temperature to 80 ℃, and respectively adding 1g of norborneolAlkene, 1g styrene, 5 mu mol alpha-iron diimine catalyst from example 1 dissolved in dichloromethane, 1mol/L cocatalyst MAO (molar ratio of cocatalyst to main catalyst 1000:1), polymerization time 3h, 10mL acidified ethanol with 10% concentration by volume until the reaction is terminated, polymer filtered, washed with water and ethanol, and dried in a vacuum drying oven at 60 ℃ for 8h to obtain polymer Mw of 1.2X 10⁶g/mol, MWD of 3.2,¹³the norbornene content of the polymer was 72% by C NMR.

In this example, the molecular weight and molecular weight distribution of the polymer were measured at 150 ℃ using a PL-GPC220 high temperature gel permeation chromatography system.

The above embodiments are preferred embodiments of the present invention, but the present invention is not limited to the above embodiments, and any other changes, modifications, substitutions, combinations, and simplifications which do not depart from the spirit and principle of the present invention should be construed as equivalents and are included in the scope of the present invention.