Nitrogen-doped anthryl-containing porous organic polymer and preparation method thereof

Abstract

The invention relates to the technical field of porous organic polymers, in particular to a nitrogen-doped anthracene-based porous organic polymer and a preparation method thereof.9, 10-dibromoanthracene serves as an initial monomer raw material, coupling is conducted through a Suzuki coupling reaction, and the novel nitrogen-doped anthracene-based porous organic polymer is designed and synthesized through Cichibabin; a unique framework of the porous polymer endows the porous polymer with relatively good electron donating ability, and the porous polymer has a large specific surface area and multiple active sites, and an extensible pi-pi conjugated network realizes selective recognition of transition metal ions, so that the problem that an existing porous polymer is insufficient in application in the field of heavy metal ion sensing is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of porous organic polymers, and particularly to a nitrogen-doped anthracene-based porous organic polymer and a preparation method thereof. Background Art

[0002] Porous Organic Polymers (POPs), as novel functional materials, have attracted much attention in the field of materials science due to their unique structural characteristics. Such materials not only have a tunable pore structure and diverse topological configurations, but also exhibit excellent chemical stability and are easy to functionalize. Their porous structure can construct a microenvironment for interacting with guest molecules. By precisely controlling the pore size distribution and the type of active sites, the material can exhibit selective recognition ability for specific ions, which provides a theoretical basis for its innovative applications in the field of chemical sensing. It should be noted that the sensing performance of the material essentially depends on the structural characteristics of its molecular building blocks. Therefore, developing suitable building units is the key to endowing the material with excellent sensing performance. Anthracene and its derivatives (such as pyrene, naphthalene, carbazole, etc.) are widely used as fluorescent chromophores due to their unique chemical structures and optical properties. As a classic polycyclic aromatic hydrocarbon, anthracene, with its rigid π-conjugated backbone and intrinsic fluorescence characteristics, has become a common building block for POPs. By introducing anthracene monomers with a rigid planar structure, the π-π stacking generated can effectively improve the stability of the material, thereby preventing pore collapse and exposing more active sites. In addition, the anthracene group can be used as a fluorescent signal unit, which can significantly improve the fluorescence performance of the material when constructing porous organic polymers.

[0003] However, the recognition ability of single anthracene-based materials for metal ions is limited, and specific functional groups need to be introduced to enhance selectivity. The introduced pyridine group, as a typical Lewis basic site, the lone pair electrons on its nitrogen atom can form strong coordination bonds with metal ions such as Fe 2+ 、Fe 3+ etc., which significantly changes the electron transition path, resulting in quenching or enhancement of the fluorescence intensity of the material, thereby achieving the functions of fluorescence signal conversion and metal recognition. And experimental data show that this system has no obvious response to common interfering ions, showing excellent selectivity. Summary of the Invention

[0004] The purpose of the present invention is to provide a nitrogen-doped anthracene-based porous organic polymer and a preparation method thereof, aiming to solve the problem of insufficient application of existing porous polymers in the field of heavy metal ion sensing.

[0005] To achieve the above purpose, in the first aspect, the present invention provides a preparation method of a nitrogen-doped anthracene-based porous organic polymer, including the following steps:

[0006] Weigh 9,10-dibromoanthracene, 4-formylphenylboronic acid and anhydrous potassium carbonate and add them to the first two-necked round-bottom flask. Measure a preset amount of tetrahydrofuran solution, aqueous solution and tetrakis(triphenylphosphine)palladium(0) and add them to the first two-necked round-bottom flask. Then, under argon protection, carry out a heating reaction to obtain a reaction solution.

[0007] After rotary evaporation of the reaction solution, add dichloromethane to dissolve it, pour it into water for extraction until it becomes clear, then collect the extract, carry out rotary evaporation and vacuum drying until constant weight to obtain an intermediate product.

[0008] Pretreat the intermediate product to obtain a semi-finished product.

[0009] After subjecting the semi-finished product to Soxhlet extraction and purification using dichloromethane, methanol and acetone respectively, place it in an oven for vacuum drying to obtain a porous organic polymer.

[0010] Among them, in the step of "pretreating the intermediate product to obtain a semi-finished product", the following steps are included:

[0011] Weigh the intermediate product, 1,4-diacetylbenzene and ammonium acetate and add them to the second two-necked round-bottom flask, dissolve them with a preset amount of pyridine to obtain a solution.

[0012] Under argon protection, heat the solution to a preset temperature for reaction, then obtain a mixture and cool it to room temperature.

[0013] Filter the mixture to obtain a precipitate, and wash the precipitate with methanol and water in sequence to obtain a semi-finished product.

[0014] Among them, in the step of "weigh 9,10-dibromoanthracene, 4-formylphenylboronic acid and anhydrous potassium carbonate and add them to the first two-necked round-bottom flask. Measure a preset amount of tetrahydrofuran solution, aqueous solution and tetrakis(triphenylphosphine)palladium(0) and add them to the first two-necked round-bottom flask. Then, under argon protection, carry out a heating reaction to obtain a reaction solution", the heating temperature is 70 °C and the reaction time is 24 hours.

[0015] Among them, in the step of "under argon protection, heat the solution to a preset temperature for reaction, then obtain a mixture and cool it to room temperature", the preset heating temperature of the solution is 115 °C and the reaction time is 24 hours.

[0016] Among them, in the step of "after subjecting the semi-finished product to Soxhlet extraction and purification using dichloromethane, methanol and acetone respectively, place it in an oven for vacuum drying to obtain a porous organic polymer", the purification time of the semi-finished product is 96 hours and the vacuum drying time is 24 hours.

[0017] Second aspect, a nitrogen-doped anthracene-based porous organic polymer is prepared by using the preparation method of the nitrogen-doped anthracene-based porous organic polymer described in the first aspect, and includes 9,10-dibromoanthracene, 4-formylphenylboronic acid, anhydrous potassium carbonate, an intermediate product, 1,4-diacetylbenzene, ammonium acetate, tetrahydrofuran, water, tetrakis(triphenylphosphine)palladium, and pyridine;

[0018] The weighed amount of 9,10-dibromoanthracene is 1 mole part; the weighed amount of 4-formylphenylboronic acid is 2 mole parts; the weighed amount of anhydrous potassium carbonate is 5 mole parts; the weighed amount of the intermediate product is 1 mole part; the weighed amount of 1,4-diacetylbenzene is 2.2 mole parts; the weighed amount of ammonium acetate is 30 mole parts; the measured amount of tetrahydrofuran is 4.32 mole parts; the measured amount of water is 0.1 mole part; the weighed amount of tetrakis(triphenylphosphine)palladium is 0.03 mole part; the measured amount of pyridine is 3.16 mole parts.

[0019] The preparation method of a nitrogen-doped anthracene-based porous organic polymer of the present invention includes the following steps: Weigh 9,10-dibromoanthracene, 4-formylphenylboronic acid and anhydrous potassium carbonate and add them to a first two-necked round-bottom flask, and measure a preset amount of tetrahydrofuran solution, aqueous solution and tetrakis(triphenylphosphine)palladium and add them to the first two-necked round-bottom flask, and carry out a heating reaction under argon protection to obtain a reaction solution; After the reaction solution is rotary evaporated, it is dissolved in dichloromethane, poured into water for extraction until it is clarified, then collected and rotary evaporated and vacuum dried to constant weight to obtain an intermediate product; The intermediate product is pretreated to obtain a semi-finished product; After the semi-finished product is Soxhlet extracted and purified by dichloromethane, methanol and acetone respectively, it is placed in an oven for vacuum drying to obtain a porous organic polymer. The present invention uses 9,10-dibromoanthracene as the initial monomer raw material, couples through the Suzuki coupling reaction, and designs and synthesizes a novel nitrogen-doped anthracene-based porous organic polymer through Chichibabin. Its unique framework endows it with good electron-donating ability. Its large specific surface area, multiple active sites and extendable π-conjugated network achieve the selective recognition of transition metal ions, thus solving the problem of insufficient application range of existing porous polymers in the field of heavy metal ion sensing. Description of the Drawings

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0021] Figure 1 is a flow chart of a preparation method of a nitrogen-doped anthracene-based porous organic polymer provided by the present invention.

[0022] Figure 2 This is the synthetic route of nitrogen-doped anthracene-based porous organic polymer POP-En in the embodiments of the present invention. In the figure: i is 4-formylphenylboronic acid, anhydrous potassium carbonate, tetrahydrofuran, water, tetrakis(triphenylphosphine)palladium; ii is 1,4-diacetylbenzene, pyridine, ammonium acetate.

[0023] Figure 3 This is the molecular structure diagram of polymer POP-En in the embodiments of the present invention.

[0024] Figure 4 This is the infrared test chart of nitrogen-doped anthracene-based porous organic polymer POP-En in the embodiments of the present invention. In the figure: 9,10-Dibromoanthracene is 9,10-dibromoanthracene. The abscissa Wavelength is the wavelength; the unit is nanometer (nm).

[0025] Figure 5 This is the solvent response degree chart of nitrogen-doped anthracene-based porous organic polymer POP-En in the embodiments of the present invention. In the figure: CHCl3 is chloroform; THF is tetrahydrofuran; DMF is N,N-dimethylformamide; DOX is 1,4-dioxane; H2O is water; MeOH is methanol; Acetone is acetone. The ordinate FL Intensity is the fluorescence intensity; the abscissa Wavelength is the wavelength; the unit is nanometer (nm).

[0026] Figure 6 For POP-En to Ca 2+ 、Mn 2+ 、Co 2+ 、K + 、Fe 3+ 、Hg 2+ 、Zn 2+ 、Ba 2+ 、Ni + 、Al 3+ 、Mg 2+ 、Na + 、Fe 2+ 、Cr 3 + Selectivity experiment of metal ions. The ordinate FL Intensity is the fluorescence intensity; the abscissa Wavelength is the wavelength; the unit is nanometer (nm).

[0027] Figure 7 This is the 1H NMR spectrum of intermediate Y-E in the embodiments of the present invention. The abscissa δ (ppm) is the chemical shift; the unit is ppm.

[0028] Figure 8 This is the flowchart for obtaining semi-finished products by preprocessing the intermediate product. Detailed implementation manners

[0029] The embodiments of the present invention will be described in detail below. Examples of the embodiments are shown in the accompanying drawings, where the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary and are intended to explain the present invention, and should not be construed as a limitation of the present invention.

[0030] Please refer to Figures 1 to 8 , in a first aspect, the present invention provides a method for preparing a nitrogen-doped anthracene-based porous organic polymer, comprising the following steps:

[0031] S1 Weigh 9,10-dibromoanthracene, 4-formylphenylboronic acid and anhydrous potassium carbonate and add them into a first two-necked round-bottom flask. Measure a preset amount of tetrahydrofuran solution, aqueous solution and tetrakis(triphenylphosphine)palladium and add them into the first two-necked round-bottom flask, and carry out a heating reaction under argon protection to obtain a reaction solution;

[0032] The heating temperature is 70 °C and the reaction time is 24 hours.

[0033] The weighed amount of 9,10-dibromoanthracene is 1 mole part; the weighed amount of 4-formylphenylboronic acid is 2 mole parts; the weighed amount of anhydrous potassium carbonate is 5 mole parts; the weighed amount of tetrakis(triphenylphosphine)palladium is 0.03 mole parts.

[0034] Specifically, weigh 9,10-dibromoanthracene, 4-formylphenylboronic acid and anhydrous potassium carbonate and add them into a first two-necked round-bottom flask. Measure a preset amount of tetrahydrofuran solution, aqueous solution and tetrakis(triphenylphosphine)palladium and add them into the first two-necked round-bottom flask to carry out a heating reaction under argon protection to obtain a reaction solution; the weighed amount of 9,10-dibromoanthracene is 1 mole part; the weighed amount of 4-formylphenylboronic acid is 2 mole parts; the weighed amount of anhydrous potassium carbonate is 5 mole parts; the weighed amount of tetrakis(triphenylphosphine)palladium is 0.03 mole parts. The heating temperature of the heating reaction is 70 °C and the reaction time is 24 hours.

[0035] S2 After the reaction solution is rotary evaporated, add dichloromethane to dissolve it, pour it into water for extraction until it is clear, then collect it, rotary evaporate it and vacuum dry it to constant weight to obtain an intermediate product;

[0036] S3 Pretreat the intermediate product to obtain a semi-finished product;

[0037] S31 Weigh the intermediate product, 1,4-diacetylbenzene, and ammonium acetate and add them into a second two-necked round-bottom flask. Measure a preset amount of pyridine to dissolve them to obtain a dissolved solution;

[0038] Specifically, in a second two-necked round-bottom flask, intermediate product, 1,4-diacetylbenzene and ammonium acetate were placed, and a preset amount of pyridine solution was measured and added to the second two-necked flask to completely dissolve, obtaining a solution. The weighed amount of the intermediate product was 1 mole portion, the weighed amount of 1,4-diacetylbenzene was 2.2 mole portions, the weighed amount of ammonium acetate was 30 mole portions, and the preset amount of pyridine was 3.16 mole portions.

[0039] S32 Under argon protection, the solution was heated to a preset temperature for reaction, obtaining a mixture and then cooled to room temperature;

[0040] The preset heating temperature of the solution was 115 °C, and the reaction time was 24 hours.

[0041] Specifically, under argon protection, the solution was heated to 115 °C for reaction for 24 hours, obtaining a mixture and then cooled to room temperature.

[0042] S33 The mixture was filtered to obtain a precipitate, and the precipitate was washed successively with methanol and water to obtain a semi-finished product.

[0043] The purification time of the semi-finished product was 96 hours, and the vacuum drying time was 24 hours.

[0044] Specifically, the precipitate obtained by filtering the mixture was washed successively with methanol and water to obtain a semi-finished product.

[0045] S4 The semi-finished product was purified by Soxhlet extraction with dichloromethane, methanol and acetone respectively, and then placed in an oven for vacuum drying to obtain a porous organic polymer.

[0046] Specifically, the semi-finished product was further purified by Soxhlet extraction with dichloromethane, methanol and acetone for 96 hours. Finally, it was placed in an 80 °C oven for vacuum drying for 24 hours to obtain a light yellow powder POP-En, and POP-En is a porous organic polymer.

[0047] Example:

[0048] Synthesis of Intermediate Y-E: Weigh 9,10-dibromoanthracene (2 g, 5.95 mmol), 4-formylphenylboronic acid (2.7 g, 18 mmol), and anhydrous potassium carbonate (1.38 g, 10 mmol) and add them to a 250 mL two-necked round-bottom flask. Measure 60 mL of tetrahydrofuran solution and 5 mL of aqueous solution, pour them into the two-necked round-bottom flask, and dissolve the raw materials thoroughly. Then add tetrakis(triphenylphosphine)palladium (0.2 g, 0.17 mmol) to the solution, heat the mixture to 70 °C, stir magnetically, and reflux for 24 h under argon protection. Subsequently, spin-dry the reaction solution, extract it with dichloromethane and water multiple times until it is clear, collect the organic phase, spin-dry it, separate it by silica gel column chromatography (dichloromethane / petroleum ether, gradient elution), collect the product, spin-dry it, and dry it in a vacuum drying oven to constant weight to obtain intermediate product Y-E with a yield of 89%. 1H NMR (500 MHz, Chloroform-d) δ 10.25 (s, 2H), 8.18 (d, J = 7.7 Hz, 4H), 7.71 (d, J = 7.7 Hz, 4H), 7.66–7.62 (m, 4H), 7.40 (dd, J = 7.0, 3.2 Hz, 4H).

[0049] Synthesis of Target Molecule POP-En: Add intermediate product Y-E (1 g, 2.6 mmol) and 1,4-diacetylbenzene (0.927 g, 5.71 mmol) to a 100 mL dry two-necked round-bottom flask respectively, dissolve them with 40 mL of pyridine, then add ammonium acetate (4.62 g, 60 mmol) to the solution, heat it to 115 °C on a magnetic stirrer, and reflux under argon protection. Stop the reaction after 24 hours. Wait for the mixture to cool to room temperature, and wash the filtered precipitate with methanol and water successively. The product is further purified by Soxhlet extraction with dichloromethane, methanol, and acetone for 96 hours. Finally, place it in an 80 °C oven and vacuum dry it for 24 hours to obtain yellow powder POP-En.

[0050] From the infrared test chart ( Figure 3 ), it can be seen that the appearance of the C=O absorption peak near 1680 cm -1 indicates the successful synthesis of the carbonyl-containing intermediate Y-E. The disappearance of the C-H absorption peak of POP-En at 2731 cm -1 , the significant weakening of the C=O absorption peak at 1680 cm -1 , the appearance of the C-N peak at 1261 cm -1 , and the increase in the proportion of the C=N absorption peak at 1600 cm -1 indicate the successful synthesis of the pyridine ring and prove the successful synthesis of the organic polymer POP-En.

[0051] Second aspect: A nitrogen-doped anthracene-based porous organic polymer is prepared by using the preparation method of the nitrogen-doped anthracene-based porous organic polymer described in the first aspect, and includes 9,10-dibromoanthracene, 4-formylphenylboronic acid, anhydrous potassium carbonate, intermediate product, 1,4-diacetylbenzene, ammonium acetate, tetrahydrofuran, water, tetrapalladium, and pyridine;

[0052] The weighed amount of the 9,10-dibromoanthracene is 1 mole part; the weighed amount of the 4-formylphenylboronic acid is 2 mole parts; the weighed amount of the anhydrous potassium carbonate is 5 mole parts; the weighed amount of the intermediate product is 1 mole part; the weighed amount of the 1,4-diacetylbenzene is 2.2 mole parts; the weighed amount of the ammonium acetate is 30 mole parts; the amount of tetrahydrofuran taken is 4.32 mole parts; the amount of water taken is 0.1 mole part; the weighed amount of the tetrapalladium is 0.03 mole part; the amount of pyridine taken is 3.16 mole parts.

[0053] The above-disclosed content is only the preferred embodiment of a nitrogen-doped anthracene-based porous organic polymer and its preparation method of the present invention. Of course, the scope of the rights of the present invention cannot be limited thereby. Those of ordinary skill in the art can understand all or part of the processes of implementing the above embodiments, and the equivalent changes made according to the claims of the present invention still fall within the scope covered by the invention.

Claims

1. A preparation method of a nitrogen-doped anthracene-based porous organic polymer, characterized in that It includes the following steps: Weigh 9,10-dibromoanthracene, 4-formylphenylboronic acid and anhydrous potassium carbonate and add them into the first two-necked round-bottom flask. Then measure a preset amount of tetrahydrofuran solution, aqueous solution and tetrakis(triphenylphosphine)palladium(0) and add them into the first two-necked round-bottom flask. Then carry out a heating reaction under argon protection to obtain a reaction solution; After rotary evaporation of the reaction solution, add dichloromethane to dissolve it, pour it into water for extraction until it is clear, then collect the extract, carry out rotary evaporation and vacuum drying until constant weight to obtain an intermediate product; Pretreat the intermediate product to obtain a semi-finished product; After subjecting the semi-finished product to Soxhlet extraction and purification with dichloromethane, methanol and acetone respectively, place it in an oven for vacuum drying to obtain a porous organic polymer.

2. The preparation method of the nitrogen-doped anthracene-based porous organic polymer according to claim 1, wherein, In "Pretreat the intermediate product to obtain a semi-finished product", it includes the following steps: Weigh the intermediate product, 1,4-diacetylbenzene and ammonium acetate and add them into the second two-necked round-bottom flask, and dissolve them with a preset amount of pyridine to obtain a solution; Under argon protection, heat the solution to a preset temperature for reaction, then obtain a mixture and cool it to room temperature; Filter the mixture to obtain a precipitate, and wash the precipitate with methanol and water in sequence to obtain a semi-finished product.

3. The preparation method of the nitrogen-doped anthracene-based porous organic polymer according to claim 1, wherein In "Weigh 9,10-dibromoanthracene, 4-formylphenylboronic acid and anhydrous potassium carbonate and add them into the first two-necked round-bottom flask. Then measure a preset amount of tetrahydrofuran solution, aqueous solution and tetrakis(triphenylphosphine)palladium(0) and add them into the first two-necked round-bottom flask. Then carry out a heating reaction under argon protection to obtain a reaction solution", the heating temperature is 70 °C and the reaction time is 24 hours.

4. The preparation method of the nitrogen-doped anthracene-based porous organic polymer according to claim 2, characterized in that, In "Under argon protection, heat the solution to a preset temperature for reaction, then obtain a mixture and cool it to room temperature", the preset heating temperature of the solution is 115 °C and the reaction time is 24 hours.

5. The preparation method of the nitrogen-doped anthracene-based porous organic polymer according to claim 1, characterized in that, In "After subjecting the semi-finished product to Soxhlet extraction and purification with dichloromethane, methanol and acetone respectively, place it in an oven for vacuum drying to obtain a porous organic polymer", the purification time of the semi-finished product is 96 hours and the vacuum drying time is 24 hours.

6. A nitrogen-doped anthracene-based porous organic polymer prepared by the method for preparing a nitrogen-doped anthracene-based porous organic polymer according to any one of claims 1-6, characterized in that, It includes 9,10-dibromoanthracene, 4-formylphenylboronic acid, anhydrous potassium carbonate, intermediate product, 1,4-diacetylbenzene, ammonium acetate, tetrahydrofuran, water, tetrakis(triphenylphosphine)palladium(0) and pyridine; The weighed amount of 9,10-dibromoanthracene is 1 molar part; the weighed amount of 4-formylphenylboronic acid is 2 molar parts; the weighed amount of anhydrous potassium carbonate is 5 molar parts; the weighed amount of the intermediate product is 1 molar part; the weighed amount of 1,4-diacetylbenzene is 2.2 molar parts; the weighed amount of ammonium acetate is 30 molar parts; the measured amount of tetrahydrofuran is 4.32 molar parts; the measured amount of water is 0.1 molar part; the weighed amount of tetrakis(triphenylphosphine)palladium(0) is 0.03 molar part; the measured amount of pyridine is 3.16 molar parts.

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