CN112011034B

CN112011034B - Dimethoxy column [ n ] arene knotting conjugated polymer and preparation method and application thereof

Info

Publication number: CN112011034B
Application number: CN202010834202.1A
Authority: CN
Inventors: 张琳; 李恒业; 虞文杰; 张丹; 陈桂勇; 高峰
Original assignee: Yancheng Customs Comprehensive Technical Service Center
Current assignee: Yancheng Customs Comprehensive Technical Service Center
Priority date: 2020-08-19
Filing date: 2020-08-19
Publication date: 2021-09-28
Anticipated expiration: 2040-08-19
Also published as: CN112011034A

Abstract

The invention discloses a dimethoxy column [ n ] arene knotting conjugated polymer and a preparation method and application thereof, belonging to the technical field of organic synthesis.A dimethoxy column [ n ] arene knotting conjugated polymer is synthesized by taking an aromatic compound as a raw material, dimethoxy column [ n ] arene as a cross-linking agent and Lewis acid as a catalyst through Friedel-Crafts reaction; the method creatively adopts dimethoxy column [ n ] arene as a cross-linking agent, adopts cheap Lewis acid as a catalyst, synthesizes the knotted conjugated polymer material containing the column [ n ] arene structure with high yield, can quickly and efficiently adsorb organic pollutants in water by the synthesized knotted conjugated polymer containing the column [ n ] arene unit, can clean and regenerate the adsorbed material through a simple organic solvent, can be repeatedly used for many times and keeps the adsorption efficiency, and well makes up the defects of the existing method for preparing the polymer containing the column [ n ] arene unit.

Description

Dimethoxy column [ n ] arene knotting conjugated polymer and preparation method and application thereof

Technical Field

The invention belongs to the technical field of organic synthesis, and particularly relates to a dimethoxy column [ n ] arene knotting conjugated polymer, and a preparation method and application thereof.

Background

Organic pollutants such as plastics, dyes, medicines, antibiotics and the like have become serious environmental problems worldwide, and seriously threaten water resources and human health. Therefore, it is necessary to develop an effective method for removing organic contaminants from water. The adsorption method has the advantages of low cost, simple operation, high efficiency and the like, and is the most common decontamination method. Inorganic adsorbents such as activated carbon, zeolite and the like are the most widely used adsorbents at present, but have inherent problems of low capacity, slow pollutant absorption, high energy consumption in the regeneration process and the like. The column [ n ] arene is a high-grade organic polymer containing a host-guest recognition unit, is a new porous polymer material, and has obviously better performance than the traditional adsorbent due to the capability of fast adsorbing pollutants and good reproducibility under mild conditions. However, the existing methods for preparing column [ n ] aromatics still have some problems to be solved urgently:

(1) low polymer yield, such as 48% yield for the preparation of polymeric materials containing pillared [5] arenes as reported in j.mater.chem.a,2017,5, 2514; matrix, chem.a,2017,5,24217 reported that the yield of polymer material containing column [5] arene was only 76%;

(2) expensive noble metal catalysts, such as expensive palladium catalysts, are generally required;

(3) for different polymers of pillared [ n ] arenes, synthesis of monomers with specific functional groups is generally required to complete the polymerization reaction, and lacks versatility, as the preparation of polymer materials containing pillared [5] arenes reported in j. mater. chem.a,2017,5,24217 employs amidation of carboxyl and amino groups, but it first requires synthesis of carboxylated pillared [5] arenes by a multi-step reaction.

The above problems hinder the preparation of the column [ n ] arene polymer, thereby also limiting its applications.

Disclosure of Invention

In order to solve the problems, the invention discloses a dimethoxy column [ n ] arene knotting conjugated polymer, a preparation method and application thereof; the preparation method takes dimethoxy column [ n ] arene as an external cross-linking agent, takes Lewis acid as a catalyst, and synthesizes the knotted conjugated polymer material containing the column [5] arene structure through Friedel-Crafts reaction with aromatic compounds with high yield, and the product is high, low in cost and universal; the synthesized knotted conjugated polymer containing the column [ n ] arene unit can quickly and efficiently adsorb organic pollutants in water, and the adsorbed material can be cleaned and regenerated by a simple organic solvent, can be repeatedly used for many times and keeps the adsorption efficiency.

The first purpose of the invention is to provide a preparation method of a dimethoxy column [ n ] arene knotted conjugated polymer, which comprises the following steps:

taking an aromatic compound as a raw material, dimethoxyl [ n ] arene as a cross-linking agent and Lewis acid as a catalyst, and synthesizing the dimethoxyl [ n ] arene knotted conjugated polymer through Friedel-Crafts reaction.

Preferably, the aromatic compound is substituted or unsubstituted C₆-C₅₀Aromatic hydrocarbons, when said aromatic hydrocarbons are substituted, these substituents being phenyl or C₁-C₂₀An alkyl group.

Preferably, the aromatic compound is benzene, biphenyl, mesitylene or tetraphenylmethane.

Preferably, the dimethoxy column [ n ] arene is dimethoxy column [5] arene or dimethoxy column [6] arene.

Preferably, the lewis acid is anhydrous ferric trichloride or anhydrous aluminum trichloride.

Preferably, the dimethoxycolumn [ n ] arene: an aromatic compound: the dosage ratio of the Lewis acid is 1: 2.5-5: 22.7-25.

Preferably, the solvent is nitrobenzene, and the dosage ratio of the Lewis acid to the nitrobenzene is 1 mol: 2-3L.

Preferably, the Friedel-Crafts reaction process is as follows: the reaction solution is reacted for 5h at 77-82 ℃ and then for 24h at 115-123 ℃.

The second object of the present invention is to provide a dimethoxy column [ n ] arene knotted conjugated polymer prepared by the above preparation method.

The third purpose of the invention is to provide the application of the dimethoxy column [ n ] arene knotted conjugated polymer in the aspect of purifying organic polluted wastewater.

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

(1) the preparation method takes dimethoxyl column [ n ] arene as an external cross-linking agent, takes Lewis acid as a catalyst, and can prepare the knotted conjugated polymer material containing the column [ n ] arene structure through Friedel-Crafts reaction with an aromatic compound by only one step, and has simple operation and high yield (more than 96 percent);

(2) the existing method for preparing the column [ n ] arene generally needs to use a noble metal catalyst with high price, and the invention uses the Lewis acid with low price and easy obtainment as the catalyst, thereby reducing the cost of materials;

(3) the existing method for preparing the column [ n ] arene needs to synthesize a monomer with a specific functional group to complete a polymerization reaction, and lacks universality, but the method has wide universality on reaction monomers, and the monomers containing aryl can be reacted with the dimethoxy column [ n ] arene through simple one-step Friedel-Crafts reaction to prepare the dimethoxy column [ n ] arene knotted conjugated polymer, so that the complex monomer synthesis step is avoided;

(4) the knotted conjugated polymer containing the column [ n ] arene structure prepared by the method has the advantages that the host-guest recognition capability of the knotted conjugated polymer enables the material to be capable of efficiently and quickly removing organic pollutants in water, and the material can be washed and regenerated by a simple organic solvent, can be repeatedly used and has huge practical application value.

Drawings

FIG. 1(a) shows CP-DMPA [5] prepared in example 1]-1 and DMPA [5]]Fourier transform infrared spectrogram of (1); (b) is CP-DMPA [5] prepared in example 1]-1 and DMPA [5]]Of (2) a solid¹³C nuclear magnetic resonance spectrum;

FIG. 2(a) is a graph of the time-dependent removal efficiency of CP-DMPA [5] -1 prepared in example 1 for measured contaminants; (b) is the percentage removal efficiency of CP-DMPA 5-1 prepared in example 1 for each contaminant at contact times of 30s and 5 min;

wherein SMP is sulfadimethoxine; the 2,4-DCP is 2, 4-dichlorophenol; BPA is bisphenol A; 2-NO is 2-naphthol; MO is methyl orange; CR is Congo red; RB is rhodamine B; FS is fluorescein sodium;

FIG. 3(a) is the adsorption time dependence of CP-DMPA [5] -1 and activated carbon prepared in example 1 on methyl orange and sodium fluorescein; (b) is the removal rate of methyl orange and fluorescein sodium of CP-DMPA 5-1 prepared in example 1 and active carbon in different contact time;

FIG. 4 is an adsorption isotherm of the organic contaminants being measured on CP-DMPA [5] -1 prepared in example 1, wherein (a)2, 4-DCP; (b) BPA; (c) 2-NO; (d) MO;

FIG. 5 is a Langmuir isotherm of adsorption of organic contaminants by CP-DMPA [5] -1 prepared in example 1; wherein (a)2, 4-DCP; (b) BPA; (c) 2-NO; (d) MO;

FIG. 6(a) is a photograph of a glass syringe filled with CP-DMPA [5] -1 prepared in example 1 used in a flow experiment; (b) photos of stock solution, residual solution and methanol eluent of rhodamine b in a regeneration experiment; (c) high performance liquid chromatography spectrum of rhodamine b stock solution and residual amount of five continuous adsorption/desorption cycles;

FIG. 7(a) contaminant removal rate in flow experiments; (b) flow removal of rhodamine b by CP-DMPA [5] -1 prepared in example 1 after successive regeneration cycles.

Detailed Description

In order to make the technical solutions of the present invention better understood and implemented by those skilled in the art, the present invention is further described below with reference to the following specific embodiments and the accompanying drawings, but the embodiments are not meant to limit the present invention.

The detection methods and experimental methods mentioned in the following examples are all conventional methods unless otherwise specified; the starting materials and reagents are commercially available unless otherwise specified.

The invention provides a preparation method of a dimethoxy column [ n ] arene knotting conjugated polymer, which comprises the following steps:

Taking dimethoxy column [5] arene as an example, the synthetic route is as follows:

wherein, the monomers containing aromatic groups can be synthesized into knotted conjugated polymers with a column [ n ] arene structure through the Friedel-Crafts reaction, and the dimethoxy column [ n ] arene is dimethoxy column [5] arene or dimethoxy column [6] arene. The above method will be specifically described below by way of examples only. It is to be understood that the described embodiments are merely exemplary of the invention, and not restrictive of the full scope of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the scope of the present invention.

Example 1

A preparation method of dimethoxy column [5] arene knotting conjugated polymer 1(CP-DMPA [5] -1) comprises the following steps:

synthesis of S1 dimethoxyl column [5] arene (DMPA [5])

1, 4-dimethoxybenzene (5.52 g, 40 mmol) and paraformaldehyde (1.20 g, 40 mmol) were weighed out and dissolved in 1, 2-dichloroethane (380 ml), trifluoroacetic acid (20 ml) was then added, and the reaction solution was refluxed at 95 ℃ for 2 hours; after the reaction is finished, cooling the reaction liquid to room temperature, pouring the reaction liquid into methanol, and collecting separated precipitates; dissolving the generated crude product in chloroform, and then adding acetone to separate out white crystals; the mixture was allowed to stand overnight and a white crystalline precipitate was collected as the product (4.32 g, 72% yield).

S2 Synthesis of CP-DMPA [5] -1

DMPA [5] (2.52 g, 3.30 mmol) prepared in S1 and benzene (1.3 g, 16.67 mmol) were weighed out and dissolved in nitrobenzene (150 ml), and anhydrous ferric chloride (12.20 g, 75.10 mmol) was added and stirred magnetically for several minutes to form a homogeneous mixture; then, reacting the reaction solution at 80 ℃ for 5 hours, and reacting at 120 ℃ for 24 hours; after the reaction is finished, cooling the reaction liquid to room temperature; the resulting solid was collected by filtration, whereupon it was washed with dichloromethane, hydrochloric acid and methanol until the filtrate was colorless; the resulting solid was soaked in methanol and stirred for 24 hours, the solid was collected by filtration and dried under vacuum at 60 ℃ for 24 hours to give CP-DMPA [5] -1(2.70 g, 99% yield).

Example 2

A preparation method of dimethoxy column [5] arene knotting conjugated polymer 2(CP-DMPA [5] -2) comprises the following steps:

s1, DMPA [5] synthesis steps as in example 1;

s2 Synthesis of CP-DMPA [5] -2

DMPA [5] (2.52 g, 3.30 mmol) and biphenyl (2.57 g, 16.67 mmol) prepared in S1 were weighed out and dissolved in nitrobenzene (150 ml), and anhydrous ferric chloride (12.20 g, 75.10 mmol) was added thereto and stirred magnetically for several minutes to form a uniform mixture; then, reacting the reaction solution at 80 ℃ for 5 hours, and reacting at 120 ℃ for 24 hours; after the reaction is finished, cooling the reaction liquid to room temperature; the resulting solid was collected by filtration, whereupon it was washed with dichloromethane, hydrochloric acid and methanol until the filtrate was colorless; the filter cake was dried under vacuum at 60 deg.C for 24 hours to give CP-DMPA [5] -2(3.98 g, 98% yield).

Example 3

A synthetic method of dimethoxy column [5] arene knotting conjugated polymer 3(CP-DMPA [5] -3) comprises the following steps:

s1, DMPA [5] synthesis steps as in example 1;

s2, synthesizing CP-DMPA 5-3;

DMPA [5] (1.53 g, 2.00 mmol) and mesitylene (1.84 g, 6.00 mmol) from S1 were weighed out and dissolved in nitrobenzene (150 ml), and anhydrous ferric chloride (8.14 g, 50.10 mmol) was added and stirred magnetically for several minutes to form a homogeneous mixture; then, reacting the reaction solution at 80 ℃ for 5 hours, and reacting at 120 ℃ for 24 hours; after the reaction, the reaction solution was cooled to room temperature. The resulting solid was collected by filtration, whereupon it was washed with dichloromethane, followed by methanol until the filtrate was colorless; the filter cake was dried under vacuum at 60 deg.C for 24 hours to give CP-DMPA [5] -3(2.70 g, 98% yield).

Example 4

A synthetic method of dimethoxy column [5] arene knotting conjugated polymer 4(CP-DMPA [5] -4) comprises the following steps:

s1, DMPA [5] synthesis steps as in example 1;

s2, synthesizing CP-DMPA 5-4;

DMPA [5] (2.52 g, 3.30 mmol) and tetraphenylmethane (2.64 g, 8.25 mmol) prepared in S1 were weighed out and dissolved in nitrobenzene (150 ml), and anhydrous ferric chloride (12.20 g, 75.10 mmol) was added thereto and stirred magnetically for several minutes to form a uniform mixture; then, reacting the reaction solution at 80 ℃ for 5 hours, and reacting at 120 ℃ for 24 hours; after the reaction is finished, cooling the reaction liquid to room temperature; the resulting solid was collected by filtration, whereupon it was washed with dichloromethane, hydrochloric acid and methanol until the filtrate was colorless; the filter cake was dried under vacuum at 60 deg.C for 24 hours to give CP-DMPA [5] -4(3.97 g, 96% yield).

Example 5

A synthetic method of dimethoxy column [6] arene knotting conjugated polymer comprises the following steps:

dimethoxycolumn [6] arene (2.52 g, 3.30 mmol) and tetraphenylmethane (2.64 g, 8.25 mmol) were weighed out and dissolved in nitrobenzene (150 ml), and anhydrous ferric chloride (12.20 g, 75.10 mmol) was added and stirred magnetically for several minutes to form a homogeneous mixture; then, reacting the reaction solution at 80 ℃ for 5 hours, and reacting at 120 ℃ for 24 hours; after the reaction is finished, cooling the reaction liquid to room temperature; the resulting solid was collected by filtration, whereupon it was washed with dichloromethane, hydrochloric acid and methanol until the filtrate was colorless; the filter cake was vacuum dried at 60 ℃ for 24 hours to give dimethoxypillared [6] arene-knotted conjugated polymer (4.01 g, 97% yield).

Example 6

A preparation method of dimethoxy column [5] arene knotting conjugated polymer 1(CP-DMPA [5] -1) is the same as example 1, except that anhydrous ferric trichloride is replaced by anhydrous aluminum trichloride.

Hereinafter, the dimethoxy pristine [ n ] arene knotted conjugated polymer prepared in the above example is characterized, and the dimethoxy pristine [ n ] arene knotted conjugated polymer prepared in examples 1 to 6 is similar to the dimethoxy pristine [ n ] arene knotted conjugated polymer prepared in the above example, and only example 1 is described below.

FIG. 1(a) is a photograph of example 1 preparationCP-DMPA [5]]-1 and DMPA [5]]Fourier transform infrared spectrogram of (1); (b) is CP-DMPA [5] prepared in example 1]-1 and DMPA [5]]Of (2) a solid¹³C nuclear magnetic resonance spectrum; from FIG. 1, the column [5] was confirmed]Successfully synthesizing the aromatic hydrocarbon knotted conjugated polymer.

SMP (sulfadimethoxine), 2,4-DCP (2, 4-dichlorophenol), BPA (bisphenol A), 2-NO (2-naphthol), MO (methyl orange), CR (Congo red), RB (rhodamine B) and FS (sodium fluorescein) are respectively prepared into 50 mu g mL^-1Aqueous solution, dimethoxy column [5] obtained in example 1]Aromatic knotted conjugated Polymer was added to the above aqueous solution (1.00mg mL)^-1) Sampling at different time points, filtering, and measuring the concentration of the pollutants in the supernatant by HPLC, wherein the pollutant removal efficiency is calculated by the following formula:

removal efficiency ═ C₀-C_t)/C₀×100％

As can be seen from fig. 2(a), the removal rate of each pollutant gradually increases with the time, and as can be seen from fig. 2(b), the removal rate of each organic matter is greater than 60% at 30s, and the removal is faster; therefore, the synthesized column [5] arene knotted conjugated polymer has extremely high adsorption rate and adsorption efficiency on various organic pollutants tested.

Using activated carbon as a comparison, methyl orange and sodium fluorescein as examples, the dimethoxy column [5] prepared in example 1 of the invention was used]Aromatic knotted conjugated polymer and activated carbon were separately tested for adsorption, and FIG. 3(a) is CP-DMPA [5] prepared in example 1]-1(1.00mg mL^-1) And activated charcoal (1.00mg mL)^-1) Adsorption time dependence on methyl orange (50. mu.g mL-1) and fluorescein sodium (50. mu.g mL-1); (b) is CP-DMPA [5] prepared in example 1]-1 removal rate of methyl orange and fluorescein sodium by contacting with activated carbon for 1min, 5min, 10min and 60 min; from FIG. 3, it can be seen that: column [5] synthesized by the invention]The adsorption performance of the aromatic knotted conjugated polymer on methyl orange and fluorescein sodium is superior to that of activated carbon.

FIG. 4 is an adsorption isotherm of the organic contaminants being measured on CP-DMPA [5] -1 prepared in example 1, wherein (a)2, 4-DCP; (b) BPA; (c) 2-NO; (d) MO, from FIG. 4: the relation between the adsorption quantity and the equilibrium adsorption quantity of the synthesized column [5] arene knotted conjugated polymer to organic pollutants conforms to a Langmuir adsorption isotherm model.

The CP-DMPA [5] prepared in example 1 was taken]-1(5mg) added to 15mL of aqueous solutions of contaminants with different concentrations (0.33 mg mL of adsorbent)^-1) After stirring overnight, it was filtered. The concentration of contaminants in the filtrate was determined by HPLC. The Langmuir adsorption isotherm is calculated as follows: c_e/q_e＝C_e/q_max,e+1/q_max,eK, wherein q_e(mg g^-1) Is the amount of contaminant adsorbed on the material at equilibrium, q_max,e(mg g^-1) Is the maximum equilibrium adsorption capacity of the contaminant, C_e(mg L^-1) Is the concentration of residual contaminants at equilibrium, K (L mol)^-1) Is the equilibrium constant. From FIG. 5, CP-DMPA [5]]Maximum adsorption of-1 to 2,4-DCP 625mg g^-1The equilibrium constant is 4727L mol^-1(ii) a Maximum adsorption of BPA 417mg g^-1The equilibrium constant is 30716L mol^-1(ii) a The maximum adsorption quantity of 2-NO is 588mg g^-1With an equilibrium constant of 5728L mol^-1(ii) a The maximum adsorption capacity for MO was 435mg g^-1The equilibrium constant is 3477L mol^-1。

Filling a layer of absorbent cotton at the inner outlet of a glass syringe with an inner diameter of 5mm, and then filling 100mg of CP-DMPA 5]-1. Then, an aqueous solution of the contaminant (50. mu.g mL) was taken^-14mL) was added to the syringe and the solution was passed through the syringe in 20 seconds, pushing with the injection rod, and the concentration of residual contaminants in the filtrate was determined by HPLC. The removal efficiency was calculated as follows:

removal efficiency ═ C₀-C_t)/C₀×100％

FIG. 6(a) is a filled glass syringe; as can be seen from FIG. 6(b), the rhodamine b solution becomes colorless after being treated, the small column adsorbing the rhodamine b can successfully elute the adsorbed rhodamine b after being washed by methanol; as can be seen from FIG. 6(c), the chromatograms obtained after 5 times of repeated adsorption were substantially identical, demonstrating that the column could be reused. As can be seen from fig. 7(a), the pillars have high adsorption efficiency for the tested 8 pollutants, and the removal rate is close to 100%; as can be seen from FIG. 7(b), the adsorption efficiency of the small column to rhodamine b is not obviously reduced after 5 times of adsorption-desorption operations.

In conclusion, the knotted conjugated polymer material containing the column [ n ] arene structure can be prepared by one-step reaction by taking dimethoxy column [ n ] arene as an external cross-linking agent and Lewis acid as a catalyst and carrying out Friedel-Crafts reaction with an aromatic compound, and the preparation method is simple to operate and high in yield (more than 96%); the invention uses the Lewis acid which is low in price and easy to obtain as the catalyst, thereby reducing the cost of the material; the invention has wide universality on reaction monomers, any monomer containing aryl can be reacted with dimethoxy column [ n ] arene through simple one-step Friedel-Crafts reaction to prepare the dimethoxy column [ n ] arene knotting conjugated polymer, thereby avoiding complex monomer synthesis steps; the knotted conjugated polymer containing the column [ n ] arene structure prepared by the method has the advantages that the host-guest recognition capability of the knotted conjugated polymer enables the material to be capable of efficiently and quickly removing organic pollutants in water, and the material can be washed and regenerated by a simple organic solvent, can be repeatedly used and has huge practical application value.

It will be apparent to those skilled in the art that various changes and modifications may be made in the present invention without departing from the spirit and scope of the invention. Thus, it is intended that such changes and modifications be included within the scope of the appended claims and their equivalents.

Claims

1. The preparation method of the dimethoxy column [ n ] arene knotting conjugated polymer is characterized by comprising the following steps:

taking an aromatic compound as a raw material, dimethoxyl [ n ] arene as a cross-linking agent, Lewis acid as a catalyst and nitrobenzene as a solvent, and synthesizing the dimethoxyl [ n ] arene knotting conjugated polymer through Friedel-Crafts reaction;

the aromatic compound is benzene, biphenyl, mesitylene or tetraphenylmethane.

2. The method for preparing the dimethoxy columnar [ n ] arene knotted conjugated polymer according to claim 1, wherein the dimethoxy columnar [ n ] arene is dimethoxy columnar [5] arene or dimethoxy columnar [6] arene.

3. The method for preparing dimethoxy knob [ n ] arene knotted conjugated polymer according to claim 1, wherein the Lewis acid is anhydrous ferric trichloride or anhydrous aluminum trichloride.

4. The method for preparing the dimethoxy pristine [ n ] arene knotted conjugated polymer according to claim 1, wherein the dimethoxy pristine [ n ] arene: an aromatic compound: the molar ratio of Lewis acid is 1: 2.5-5: 22.7-25.

5. The method for preparing dimethoxy columnar [ n ] arene knotted conjugated polymer according to claim 1, wherein the dosage ratio of Lewis acid to nitrobenzene is 1 mol: 2-3L.

6. The preparation method of the dimethoxy phenylic knotted conjugated polymer of claim 1, wherein the Friedel-Crafts reaction process comprises the following steps: the reaction solution is reacted for 5h at 77-82 ℃ and then for 24h at 115-123 ℃.