阅读说明：本技术 一种含偶氮苯多孔聚季鏻盐离子液体的合成方法 (Method for synthesizing porous polyquaternary phosphonium salt ionic liquid containing azobenzene ) 是由 熊玉兵 何梦婷 周宁 戴志锋 于 2021-09-22 设计创作，主要内容包括：本发明属于合成领域,具体涉及一种含偶氮苯多孔聚季鏻盐离子液体的合成方法,包括：步骤1,三(4-乙烯基苯基)膦的合成：以4-溴苯乙烯为原材料制备三(4-乙烯基苯基)膦；步骤2,多孔有机聚合物POP的合成：以三(4-乙烯基苯基)膦和偶氮二异丁腈为原料制备聚三(4-乙烯基苯基)膦；步骤3,2-溴乙基-4-偶氮苯基醚(AzoC2Br)的合成：以4-羟基偶氮苯和溴乙烷为原料制备2-溴乙基-4-偶氮苯基醚；步骤4,偶氮修饰多孔聚季鏻盐离子液体的合成：以POP和2-溴乙基-4-偶氮苯基醚为原料制备含偶氮苯多孔聚季鏻盐离子液体。本发明解决了现有技术的空白,采用溶剂热法成功合成了多孔聚合物,然后季鏻化引入偶氮基团制备了含偶氮苯多孔聚季鏻盐离子液体。(The invention belongs to the field of synthesis, and particularly relates to a synthesis method of porous poly-quaternary phosphonium salt ionic liquid containing azobenzene, which comprises the following steps: step 1, synthesis of tris (4-vinylphenyl) phosphine: preparing tri (4-vinyl phenyl) phosphine by taking 4-bromostyrene as a raw material; and 2, synthesizing a porous organic polymer POP: preparing poly (tri (4-vinylphenyl) phosphine by taking tri (4-vinylphenyl) phosphine and azodiisobutyronitrile as raw materials; step 3, synthesis of 2-bromoethyl-4-azophenyl ether (AzoC2 Br): preparing 2-bromoethyl-4-azophenyl ether by using 4-hydroxyazobenzene and bromoethane as raw materials; step 4, synthesis of azo modified porous polyquaternary phosphonium salt ionic liquid: preparing porous poly-quaternary phosphonium salt ionic liquid containing azobenzene by using POP and 2-bromoethyl-4-azophenyl ether as raw materials. The method solves the blank of the prior art, successfully synthesizes the porous polymer by adopting a solvothermal method, and then introduces azo groups into quaternary phosphonylation to prepare the porous poly-quaternary phosphonium salt ionic liquid containing azobenzene.)

1. A synthetic method of porous poly-quaternary phosphonium salt ionic liquid containing azobenzene is characterized by comprising the following steps: the method comprises the following steps:

step 1, synthesis of tris (4-vinylphenyl) phosphine: preparing tri (4-vinyl phenyl) phosphine by taking 4-bromostyrene as a raw material;

and 2, synthesizing a porous organic polymer POP: preparing poly (tri (4-vinylphenyl) phosphine by taking tri (4-vinylphenyl) phosphine and azodiisobutyronitrile as raw materials;

step 3, synthesis of 2-bromoethyl-4-azophenyl ether (AzoC2 Br): preparing 2-bromoethyl-4-azophenyl ether by using 4-hydroxyazobenzene and bromoethane as raw materials;

step 4, synthesis of azo modified porous polyquaternary phosphonium salt ionic liquid: preparing porous poly-quaternary phosphonium salt ionic liquid containing azobenzene by using POP and 2-bromoethyl-4-azophenyl ether as raw materials.

2. The method for synthesizing porous poly-quaternary phosphonium salt ionic liquid containing azobenzene according to claim 1, wherein: the 4-bromostyrene in the step 1 is purified by reduced pressure distillation before use.

3. The method for synthesizing porous poly-quaternary phosphonium salt ionic liquid containing azobenzene according to claim 1, wherein: the specific steps in the step 1 are as follows: s1, adding magnesium powder into a three-neck round-bottom flask under the protection of nitrogen, vacuumizing and drying, heating the flask and a glass instrument for 20min by a hot air blower, and drying the magnesium powder; s2, adding THF, adding ethyl bromide, and activating magnesium powder; s3, slowly adding 4-bromostyrene under the ice bath condition, and controlling the temperature to be 10-20 ℃; s4, slowly adding phosphorus trichloride, and keeping the temperature at 10-20 ℃; cooling in ice bath, slowly adding saturated ammonium chloride solution for quenching to obtain a mixture; s5, extracting the mixture with diethyl ether, suction-filtering the organic layer, collecting the filtrate and concentrating to obtain the crude product, purifying the crude product by column chromatography, wherein the eluent is petroleum ether: ethyl acetate (100: 1 by volume) was rotary evaporated to remove the solvent to give a white solid powder, i.e., tris (4-vinylphenyl) phosphine.

4. The method for synthesizing porous poly-quaternary phosphonium salt ionic liquid containing azobenzene according to claim 1, wherein: the specific steps in the step 2 are as follows: t1, adding tris (4-vinylphenyl) phosphine into a single-neck round-bottom flask, adding Tetrahydrofuran (THF) and Azobisisobutyronitrile (AIBN), transferring the mixture into a reaction kettle, and reacting at 100 ℃; t2, after reacting for 24h, cooling the reaction liquid to room temperature, washing with dichloromethane, filtering, drying in a vacuum drying oven to obtain white solid powder, namely the poly-tri (4-vinylphenyl) phosphine (POP).

5. The method for synthesizing porous poly-quaternary phosphonium salt ionic liquid containing azobenzene according to claim 1, wherein: the specific steps in the step 3 are as follows: a1, adding 4-hydroxyazobenzene, bromoethane and potassium carbonate into a round-bottom flask filled with acetone, carrying out reflux reaction on a reaction system at 70 ℃ under the protection of nitrogen atmosphere, cooling to room temperature after the reaction is finished, and adding hydrochloric acid to dissolve the potassium carbonate in the system; a2, extracting with dichloromethane, washing the organic phase with distilled water and saturated brine respectively, removing the solvent by rotary evaporation, and drying the product at 60 ℃ overnight to obtain an orange powdery solid.

6. The method for synthesizing porous poly-quaternary phosphonium salt ionic liquid containing azobenzene according to claim 1, wherein: the specific steps in the step 4 are as follows: adding POP into a single-neck round-bottom flask, and adding N, N-Dimethylformamide (DMF) and AzoC₂Br, reflux reaction at 70 ℃ in nitrogen atmosphere; and after 48h of reaction, cooling to room temperature, carrying out suction filtration on the mixture to obtain light yellow solid powder, extracting the light yellow solid powder for 48h by using a Soxhlet extractor, collecting the solid powder, and carrying out vacuum drying at 60 ℃ for 8h to obtain the target product, namely the porous poly-quaternary phosphonium salt ionic liquid (Azo-POP) containing azobenzene.

Technical Field

The invention belongs to the field of synthesis, and particularly relates to a method for synthesizing porous poly-quaternary phosphonium salt ionic liquid containing azobenzene.

Background

The Porous Organic Polymers (POPs) are novel porous materials, have a large specific surface area, adjustable pore size, easy surface functionalization modification and other excellent properties, and therefore have wide application in the fields of gas absorption, separation, storage, conversion and the like. However, the porous organic polymer shows weakness in photoresponse, and the actual use value of the porous organic polymer is greatly reduced.

Disclosure of Invention

Aiming at the problems in the prior art, the invention provides a method for synthesizing porous polyquaternary phosphonium salt ionic liquid containing azobenzene, which solves the blank in the prior art, successfully synthesizes porous polymer by adopting a solvothermal method, and then introduces azo groups into the quaternary phosphonium to prepare the porous polyquaternary phosphonium salt ionic liquid containing azobenzene.

In order to achieve the technical purpose, the technical scheme of the invention is as follows:

a synthetic method of porous poly-quaternary phosphonium salt ionic liquid containing azobenzene comprises the following steps:

step 1, synthesis of tris (4-vinylphenyl) phosphine: preparing tri (4-vinyl phenyl) phosphine by taking 4-bromostyrene as a raw material; the method comprises the following specific steps: 4-bromostyrene is purified by reduced pressure distillation before use; s1, adding magnesium powder into a three-neck round-bottom flask under the protection of nitrogen, vacuumizing and drying, heating the flask and a glass instrument for 20min by a hot air blower, and drying the magnesium powder; s2, adding THF, adding ethyl bromide, and activating magnesium powder; s3, slowly adding 4-bromostyrene under the ice bath condition, and controlling the temperature to be 10-20 ℃; s4, slowly adding phosphorus trichloride, and keeping the temperature at 10-20 ℃; cooling in ice bath, slowly adding saturated ammonium chloride solution for quenching to obtain a mixture; s5, extracting the mixture with diethyl ether, suction-filtering the organic layer, collecting the filtrate and concentrating to obtain the crude product, purifying the crude product by column chromatography, wherein the eluent is petroleum ether: ethyl acetate (100: 1) by volume ratio, and removing the solvent by rotary evaporation to obtain white solid powder, namely tris (4-vinylphenyl) phosphine;

and 2, synthesizing a porous organic polymer POP: the preparation method of the poly (tri (4-vinylphenyl) phosphine by using the tri (4-vinylphenyl) phosphine and the azobisisobutyronitrile as raw materials comprises the following steps: t1, adding tris (4-vinylphenyl) phosphine to a single-neck round-bottom flask, adding 10mL of Tetrahydrofuran (THF) and Azobisisobutyronitrile (AIBN), transferring the mixture to a reaction kettle (20mL), and reacting at 100 ℃; t2, after reacting for 24 hours, cooling the reaction liquid to room temperature, washing with dichloromethane, filtering, drying in a vacuum drying oven to obtain white solid powder, namely poly tri (4-vinylphenyl) phosphine (POP);

step 3, synthesis of 2-bromoethyl-4-azophenyl ether (AzoC2 Br): the method for preparing the 2-bromoethyl-4-azophenyl ether by using the 4-hydroxyazobenzene and bromoethane as raw materials comprises the following steps: a1, adding 4-hydroxyazobenzene, bromoethane and potassium carbonate into a round-bottom flask filled with 50mL of acetone, carrying out reflux reaction on a reaction system at 70 ℃ under the protection of nitrogen atmosphere, cooling to room temperature after the reaction is finished, and adding hydrochloric acid to dissolve the potassium carbonate in the system; a2, extracting by using dichloromethane, washing an organic phase by using distilled water and saturated salt water respectively, removing a solvent by rotary evaporation, and drying a product at 60 ℃ overnight to obtain an orange powdery solid;

step 4, synthesis of azo modified porous polyquaternary phosphonium salt ionic liquid: preparing porous polyquaternary phosphonium salt ionic liquid containing azobenzene by using POP and 2-bromoethyl-4-azophenyl ether as raw materials, and specifically comprising the following steps: POP was added to a 100mL single neck round bottom flask, followed by N, N-Dimethylformamide (DMF) and AzoC₂Br, reflux reaction at 70 ℃ in nitrogen atmosphere; and after 48h of reaction, cooling to room temperature, carrying out suction filtration on the mixture to obtain light yellow solid powder, extracting the light yellow solid powder for 48h by using a Soxhlet extractor, collecting the solid powder, and carrying out vacuum drying at 60 ℃ for 8h to obtain the target product, namely the porous poly-quaternary phosphonium salt ionic liquid (Azo-POP) containing azobenzene.

From the above description, it can be seen that the present invention has the following advantages:

1. the method solves the blank of the prior art, successfully synthesizes the porous polymer by adopting a solvothermal method, and then introduces azo groups into quaternary phosphonylation to prepare the porous poly-quaternary phosphonium salt ionic liquid containing azobenzene.

2. The introduction of azobenzene adopted by the invention improves the CO content of the porous organic polymer₂Can reversibly adjust the affinity of the porous organic polymer to CO by light and heat treatment₂The adsorption capacity of (1).

3. In the invention, the cis-trans isomerization of the azobenzene side group is realized by ultraviolet irradiation and heat treatment, so that the pore structure of the Azo-POPs has adjustability.

Drawings

FIG. 1 shows POP and AzoC in example 1₂FT-IR spectra of Br and Azo-POP;

FIG. 2 is a UV-vis analysis of porous organic polymers containing azobenzene, wherein (a) the ultraviolet-visible diffuse reflectance spectrum of Azo-POP under ultraviolet light (wavelength 365nm) and (b) the ultraviolet-visible diffuse reflectance spectrum of Azo-POP under visible light (indoor natural light);

FIG. 3 is a graph showing the pore properties of an azobenzene-containing porous polyquaternary phosphonium salt ionic liquid, wherein (a) N of POP, Azo-POP and a blank control sample (a sample obtained by subjecting POP to the same reaction conditions as those for synthesizing Azo-POP)₂Adsorption and desorption isotherms, (b) pore size distribution maps of POP, Azo-POP and blank control samples;

FIG. 4 is CO of porous organic polymer containing azobenzene₂Adsorption Performance analysis, in which (a)273K and (b)298K CO of Azo-POP₂Adsorption isotherms, initial (black), after 24h uv irradiation (red) and after heating (blue).

Detailed Description

An embodiment of the present invention is described in detail with reference to fig. 1 to 4, but the present invention is not limited in any way by the claims.

Example 1

A synthetic method of porous poly-quaternary phosphonium salt ionic liquid containing azobenzene comprises the following steps:

step 1, synthesis of tris (4-vinylphenyl) phosphine: preparing tri (4-vinyl phenyl) phosphine by taking 4-bromostyrene as a raw material; the method comprises the following specific steps: 4-bromostyrene is purified by reduced pressure distillation before use; s1, adding magnesium powder (3.60g, 150mmol) into a three-neck round-bottom flask under nitrogen protection, vacuum-drying, heating the flask and a glass instrument for 20min with a hot air blower, and drying the magnesium powder; s2, adding 80mL of HF, adding bromoethane (0.5mL), and activating magnesium powder; s3, slowly adding 4-bromostyrene (18.33g, 100mmol) under the ice-bath condition, and controlling the temperature to be 10-20 ℃; s4, phosphorus trichloride (3.43g, 25mmol) was added slowly and the temperature was maintained at 10-20 ℃; cooling in ice bath, and slowly adding saturated ammonium chloride solution (100mL) for quenching to obtain a mixture; s5, extracting the mixture with diethyl ether, suction-filtering the organic layer, collecting the filtrate and concentrating to obtain the crude product, purifying the crude product by column chromatography, wherein the eluent is petroleum ether: ethyl acetate 100:1 (volume ratio), removing the solvent by rotary evaporation to obtain white solid powder, namely tris (4-vinylphenyl) phosphine, and obtaining the yield: 3.93g, 46.2%; the synthesis process comprises the following steps:

and 2, synthesizing a porous organic polymer POP: the preparation method of the poly (tri (4-vinylphenyl) phosphine by using the tri (4-vinylphenyl) phosphine and the azobisisobutyronitrile as raw materials comprises the following steps: t1, tris (4-vinylphenyl) phosphine (1.09g, 3.21mmol) was added to a single neck round bottom flask, 10mL of Tetrahydrofuran (THF) and Azobisisobutyronitrile (AIBN) (0.04g, 0.21mmol) were added, the mixture was transferred to a reaction vessel (20mL) and reacted at 100 ℃; t2, after reacting for 24h, cooling the reaction liquid to room temperature, washing with dichloromethane, filtering, drying in a vacuum drying oven to obtain white solid powder, namely the product poly (4-vinylphenyl) phosphine (POP), with the yield: 1.05g, 96.7%, and the specific synthesis process is as follows:

step 3, synthesis of 2-bromoethyl-4-azophenyl ether (AzoC2 Br): the method for preparing the 2-bromoethyl-4-azophenyl ether by using the 4-hydroxyazobenzene and bromoethane as raw materials comprises the following steps: a1, adding 4-hydroxyazobenzene (2.9841g,15.03mmol), bromoethane (10.9803g,45.00mmol) and potassium carbonate (5.5321g,40.01mmol) into a round-bottom flask containing 50mL of acetone, refluxing the reaction system at 70 ℃ under the protection of nitrogen, cooling to room temperature after the reaction is finished, and adding potassium carbonate in a hydrochloric acid dissolving system; a2, extracted with dichloromethane (50mL), the organic phase was washed with distilled water and saturated brine, the solvent was removed by rotary evaporation, and the product was dried overnight at 60 ℃ to give an orange powdery solid in yield: 3.13g, 67.2%, the specific synthesis was as follows:

step 4, synthesis of azo modified porous polyquaternary phosphonium salt ionic liquid: preparing porous polyquaternary phosphonium salt ionic liquid containing azobenzene by using POP and 2-bromoethyl-4-azophenyl ether as raw materials, and specifically comprising the following steps: POP (0.14g, 0.4mmol) was charged to a 100mL single neck round bottom flask, and 12mL of N, N-Dimethylformamide (DMF) and AzoC were added₂Br (0.12g, 0.4mmol), reflux reaction at 70 ℃ under nitrogen atmosphere; after 48 hours of reaction, cooling to room temperature, carrying out suction filtration on the mixture to obtain light yellow solid powder, extracting the light yellow solid powder by using a Soxhlet extractor with chloroform for 48 hours, collecting the solid powder, and carrying out vacuum drying at 60 ℃ for 8 hours to obtain the target product, namely, porous poly-quaternary phosphonium salt ionic liquid (Azo-POP) containing azobenzene, wherein the yield is as follows: 0.12g, 85.7%, the specific synthesis is as follows:

and (3) performance detection:

FT-IR analysis: as shown in FIG. 1, POP and AzoC are shown₂FTIR spectra of Br and Azo-POP. Some typical peaks can be identified, such as: 1597cm^-12820cm from the stretching vibration peak of the benzene ring skeleton^-1And (3) a stretching vibration peak of C-H on methylene. In particular, in the IR spectrum of Azo-POP, 1365cm^-1An expansion vibration peak of N-N is generated, which indicates that the azo group is successfully formedPOP is modified, and the porous organic polymer containing azo is successfully synthesized.

2. Ultraviolet-visible diffuse reflectance spectrum: as shown in fig. 2, fig. 2a and 2b are ultraviolet-visible diffuse reflectance spectra of Azo-POP under ultraviolet light (wavelength 365nm) and visible light (indoor natural light), respectively. As can be seen from FIG. 2a, after 10min of ultraviolet irradiation (wavelength 365nm), the absorption peak at 353nm is obviously weakened, while the absorption peak at 460nm is strengthened, which indicates that the azo group in the porous organic polymer is changed from trans configuration to cis configuration under the ultraviolet irradiation. This is because the molecular fairness becomes poor after isomerization of the azobenzene group, and the conjugated system is broken to cause a decrease in molar absorption coefficient. Then the sample is irradiated by visible light (indoor natural light) for 10min, as shown in FIG. 2b, the absorption peak at the wavelength of 460nm is weakened, and the absorption peak at 353nm is obviously strengthened, which shows that the azobenzene group is changed from cis configuration to trans configuration again under the irradiation of the visible light. It is demonstrated to have photo-reversible cis-trans isomerism properties.

3. Analysis of pore properties: as shown in FIG. 3, N was measured at 77K₂Adsorption isotherms were used to characterize the porosity of the porous samples. As shown in FIG. 3a, N₂And the adsorption isotherm shows that the porous structure of the POP is reserved after the POP modifies the azo group. And the BET specific surface area of the Azo-POP obtained after modification of the Azo group was from 1088.7m²The/g is reduced to 776.2m²The average pore size also decreased, from 8.13nm to 5.73nm (FIG. 3 b).

4.CO₂And (3) analysis of adsorption performance: as shown in FIG. 4, the initial state of Azo-POP, the first UV light treatment and the heat-treated CO at 273K and 298K₂Adsorption isotherms, it can be observed that after UV irradiation for 24h, the Azo-POP is CO at temperatures of 273K and 298K and a pressure of 760mmHg₂The absorption values are all reduced and reversible changes occur after heat treatment. Prove it to CO₂The adsorption capacity of (b) can be adjusted by ultraviolet light irradiation and heat treatment.

In summary, the invention has the following advantages:

1. the method solves the blank of the prior art, successfully synthesizes the porous polymer by adopting a solvothermal method, and then introduces azo groups into quaternary phosphonylation to prepare the porous poly-quaternary phosphonium salt ionic liquid containing azobenzene.

2. The introduction of azobenzene adopted by the invention improves the CO content of the porous organic polymer₂Can reversibly adjust the affinity of the porous organic polymer to CO by light and heat treatment₂The adsorption capacity of (1).

3. In the invention, the cis-trans isomerization of the azobenzene side group is realized by ultraviolet irradiation and heat treatment, so that the pore structure of the Azo-POPs has adjustability.

It should be understood that the detailed description of the invention is merely illustrative of the invention and is not intended to limit the invention to the specific embodiments described. It will be appreciated by those skilled in the art that the present invention may be modified or substituted equally as well to achieve the same technical result; as long as the use requirements are met, the method is within the protection scope of the invention.