Preparation method of BNF two-dimensional material based on B-N dynamic covalent bond interaction

Abstract

The invention relates to a preparation method of a BNF two-dimensional material based on B <-N dynamic covalent bond interaction. The preparation method comprises the following steps: respectively reacting 4, 4 '-(5'-(4-(4-pyridyl) phenyl)-[1, 1 ': 3', 1 ''-terphenyl]-4, 4''-diyl) bipyridine (N1 for short), tris (4-(4-pyridyl) phenyl) amine (N2 for short) and tris (4-(1H-imidazole-1-yl) phenyl) (N3 for short) with 4, 4 '-(5'-(4-(4-pyridyl) phenyl) (3, 11-diethyl-5, 9-dioxo-13b-boron naphtho [3, 2, 1-de] anthracene) (B for short) to generate BNF-1, BNF-2 and BNF-3 two-dimensional materials; compared with a monomer self-assembly body, the self-assembly body has a fluorescent discoloration characteristic and irritant response, and has a wide application prospect.

Description

Technical Field

[0001] The present invention belongs to the technical field of dynamic covalent bond materials, and in particular relates to a method for preparing a BNF two-dimensional material based on B←N dynamic covalent bond interaction. Background Art

[0002] In the past three decades, the rise of metal organic framework (MOF) chemistry has not only significantly broadened the research field of porous materials, but also triggered a revolution in solid-state materials chemistry (J.Am.Chem.Soc.1998,120,33,8571–8572). The structure and properties of MOF materials can be rationally designed through the so-called reticular chemistry, which makes them show great potential in applications such as gas storage, separation and catalysis. MOF chemistry further pioneered the establishment of covalent organic framework (COF) chemistry (Science355,923–931). With the in-depth study of MOF and covalent organic framework (COF), the scientific community has gradually realized the possibility of new porous materials constructed using weaker interactions. For example, hydrogen bonding is widely used to form porous hydrogen-bonded organic frameworks (HOFs), and these new materials have good reversibility and recyclability (Angew.Chem.Int.Ed.Engl.56,2101–2104).

[0003] In this context, coordinated B←N framework (BNF) as an emerging porous material has attracted the attention of researchers. In 2011, Severin et al. first conducted research on organic frameworks based on coordinated BN bonds. Although early BNF materials had challenges in stability, they laid the foundation for the development of BNF chemistry (Angew. Chem. Int. Ed. 2011, 50, 3034-3037). The binding energy of BN bonds is about 100 kJ / mol, which is significantly higher than traditional hydrogen bonds (usually 10-40 kJ / mol), which means that BNF has the potential to achieve breakthroughs in structural stability and persistent porosity.

[0004] However, BNF materials currently exist in an amorphous state and are easily degraded in high humidity environments, which makes them less stable during solvent exchange and thermal activation. Therefore, developing BNF materials with good stability and persistent porosity has become a key research goal. Summary of the invention

[0005] The purpose of the present invention is to avoid the shortcomings of the prior art and provide a method for preparing BNF two-dimensional materials based on B←N dynamic covalent bond interaction.

[0006] To achieve the above object, the technical solution adopted by the present invention is: a method for preparing BNF two-dimensional materials based on B←N dynamic covalent bond interaction, characterized in that the specific steps are as follows:

[0007] First, the monomer molecule 7,7"-((2,5-docosyl-1,4-phenyl)bis(ethynyl-2,1-diyl))bis(3,11-diethyl-5,9-dioxy-13b-boronaphtho[3,2,1-de]anthracene) was synthesized. The synthesis route is as follows:

[0008]

[0009] Secondly, the monomer molecule 7,7"-((2,5-docosyl-1,4-phenyl)bis(ethynyl-2,1-diyl))bis(3,11-diethyl-5,9-dioxy-13b-boronaphtho[3,2,1-de]anthracene) (abbreviated as B) was reacted with 4,4'-(5'-(4-(4-pyridyl)phenyl)-[1,1':3',1"-terphenyl]-4,4"-diyl)bipyridine (abbreviated as N1), tris(4-(4-pyridyl)phenyl)amine (abbreviated as N2) and tris(4-(1H-imidazol-1-yl)phenyl)amine (abbreviated as N3) to prepare BNF-1 two-dimensional material, BNF-2 two-dimensional material and BNF-3 two-dimensional material respectively;

[0010] The structural formula of the 4,4'-(5'-(4-(4-pyridyl)phenyl)-[1,1':3',1"-terphenyl]-4,4"-diyl)bipyridine is:

[0011]

[0012] The structural formula of the tris(4-(4-pyridyl)phenyl)amine is:

[0013]

[0014] The structural formula of the tris(4-(1H-imidazole-1-yl)phenyl)amine is:

[0015]

[0016] The specific steps of the synthesis method of the monomer molecule 7,7"-((2,5-docosyl-1,4-phenyl)bis(acetylene-2,1-diyl))bis(3,11-diethyl-5,9-dioxy-13b-boronaphtho[3,2,1-de]anthracene) are as follows:

[0017] Step 1: 2,5-dibromo-1,3-difluorobenzene, 3-ethylphenol and potassium carbonate are added to a Schlenk bottle in proportion, and then a solvent N-methylpyrrolidone is added under a nitrogen environment. After stirring at 175-185° C. for 2-3 hours, the temperature is raised to 190-195° C. and stirred for another 2-3 hours; after the reaction is completed and cooled to room temperature, ethyl acetate is added for dilution, and then the reaction mixture is extracted with water and ethyl acetate for 2-3 times, and then anhydrous sodium sulfate is added to dry the combined organic extracts, and the solvent is removed by a rotary evaporator to obtain a crude product, and then the crude product is purified to obtain product 1, and product 1 is specifically 3,3'-((2,5-dibromo-1,3-phenyl)bis(oxy))bis(ethylbenzene);

[0018] Step 2: Add product 1 to a Schlenk bottle, add xylene and n-butyl lithium in sequence under nitrogen and ice bath conditions, then return to room temperature for reaction for 1-2 hours, then add boron tribromide under ice bath conditions, keep ice bath, react for 1-2 hours, keep this temperature, then slowly add N,N-diisopropylethylamine, then raise the temperature to 130-140° C., after the reaction is completed and cooled to room temperature, remove the solvent with a rotary evaporator, extract the mixture with saturated sodium acetate solution and dichloromethane 2-3 times, add anhydrous sodium sulfate to dry the combined organic extracts, remove the solvent with a rotary evaporator to obtain a crude product, and then purify the crude product to obtain product 2, which is specifically 3,3'-((2,5-dibromo-1,3-phenyl)bis(oxy))bis(ethylbenzene);

[0019] Step 3: 1,4-bis(dodecyloxy)-2,5-diethynylbenzene, product 2, tetratriphenylphosphine palladium and cuprous iodide are added to a container in proportion, and solvents diisopropylamine and tetrahydrofuran are added to fully dissolve under a nitrogen atmosphere, and stirred at a constant temperature of 75-80°C for 12-24 hours. After the reaction is completed and cooled to room temperature, the solvents diisopropylamine and tetrahydrofuran are removed by low-pressure evaporation, and then dichloromethane is added, and the filter residue is filtered out, and the filter residue is washed with saturated ammonium chloride solution and methanol for 2-4 times to obtain a crude product, which is then placed in a vacuum environment of 50-60°C for 12-24 hours, and the obtained solid is cooled to room temperature to obtain the target product B. Product B is specifically a monomer molecule 7,7"-((2,5-dodecyl-1,4-phenyl)bis(acetylene-2,1-diyl))bis(3,11-diethyl-5,9-dioxy-13b-boronaphtho[3,2,1-de]anthracene).

[0020] Furthermore, in step 1, 2,5-dibromo-1,3-difluorobenzene, 3-ethylphenol and potassium carbonate are added in a molar ratio of 1:4:5; the amount of N-methylpyrrolidone added is 10-20 mL; the crude product is purified by column chromatography filled with silica gel, and the eluent is petroleum ether.

[0021] In step 2, product 1, n-butyl lithium, boron tribromide and N,N-diisopropylethylamine are added in a molar ratio of 2:2:3:3; the volume of xylene added is 10-20 mL; the time for boron tribromide and N,N-diisopropylethylamine to be added dropwise to the reaction mixture is controlled to be more than 5 minutes;

[0022] In step 2, the crude product is purified by column chromatography using silica gel as filling and petroleum ether as eluent, and then washed with methanol 2-3 times. The washed solid is placed in a vacuum environment at 50-60° C. for 12-24 hours and then cooled to room temperature.

[0023] In step 3, 1,4-bis(dodecyloxy)-2,5-diethynylbenzene, product 2, tetrakistriphenylphosphine palladium and cuprous iodide are added in a molar ratio of 4:6:1:2; the ratio of solvent diisopropylamine and tetrahydrofuran is 1:1, and the total volume is 10-15 mL.

[0024] Furthermore, in step 2, the xylene and N,N-diisopropylethylamine are both dried over 5A molecular sieves; and the solution is heated under a constant temperature oil bath.

[0025] Furthermore, the preparation method of the BNF-1 two-dimensional material is specifically as follows: dissolving the monomer molecules 7,7"-((2,5-dioctyl-1,4-phenyl)bis(acetylene-2,1-diyl))bis(3,11-diethyl-5,9-dioxy-13b-boronaphtho[3,2,1-de]anthracene) and 4,4'-(5'-(4-(4-pyridyl)phenyl)-[1,1':3',1"-terphenyl]-4,4"-diyl)bipyridine in proportion in 5-10 mL of o-dichlorobenzene, heating to 150-160°C for reaction for 24 hours, cooling to room temperature after the reaction and ice bathing for 1 hour, and filtering to obtain the filter residue, which is the BNF-1 two-dimensional material;

[0026] The preparation method of the BNF-2 two-dimensional material is specifically as follows: dissolving monomer molecules 7,7″-((2,5-dioctyl-1,4-phenyl)bis(acetylene-2,1-diyl))bis(3,11-diethyl-5,9-dioxy-13b-boronaphtho[3,2,1-de]anthracene) and tri(4-(4-pyridyl)phenyl)amine in proportion in 5-10 mL of o-dichlorobenzene, heating to 150-160° C. for reaction for 24 h, cooling to room temperature and ice bathing for 1 h after the reaction, and filtering to obtain the filter residue, which is the BNF-2 two-dimensional material;

[0027] The preparation method of the BNF-3 two-dimensional material is specifically as follows: dissolving the monomer molecules 7,7"-((2,5-didecyl-1,4-phenyl)bis(acetylene-2,1-diyl))bis(3,11-diethyl-5,9-dioxy-13b-boronaphtho[3,2,1-de]anthracene) and tri(4-(1H-imidazole-1-yl)phenyl)amine in proportion in 5-10 mL of o-dichlorobenzene, heating to 150-160°C for reaction for 24 hours, cooling to room temperature and placing in an ice bath for 1 hour after the reaction is completed, and filtering to obtain the filter residue, which is the BNF-3 two-dimensional material.

[0028] Further, the molar ratio of the monomer molecules 7,7″-((2,5-docosyl-1,4-phenyl)bis(ethynyl-2,1-diyl))bis(3,11-diethyl-5,9-dioxo-13b-boronaphtho[3,2,1-de]anthracene) to 4,4′-(5′-(4-(4-pyridyl)phenyl)-[1,1′:3′,1″-terphenyl]-4,4″-diyl)bipyridine is 3:2;

[0029] The molar ratio of the monomer molecule 7,7″-((2,5-docosyl-1,4-phenyl)bis(ethynyl-2,1-diyl))bis(3,11-diethyl-5,9-dioxo-13b-boronaphtho[3,2,1-de]anthracene) to tri(4-(4-pyridyl)phenyl)amine is 3:2;

[0030] The molar ratio of the monomer molecule 7,7″-((2,5-docosyl-1,4-phenyl)bis(acetylene-2,1-diyl))bis(3,11-diethyl-5,9-dioxy-13b-boronaphtho[3,2,1-de]anthracene) to tri(4-(1H-imidazol-1-yl)phenyl)amine is 3:2.

[0031] The beneficial effects of the present invention are as follows: the desired monomer molecule tetra-tert-butyl 7,7"-((2,5-docosyl-1,4-phenyl)bis(ethynyl-2,1-diyl))bis(3,11-diethyl-5,9-dioxy-13b-boronaphtho[3,2,1-de]anthracene), referred to as B, is obtained by a series of organic synthesis methods. Three Lewis base molecules are designed: 4,4'-(5'-(4-(4-pyridyl)phenyl)-[1,1':3',1"-terphenyl]-4,4"-diyl)bipyridine, referred to as N1; tris(4-(4-pyridyl)phenyl)amine, referred to as N2; tris(4 -(1H-imidazole-1-yl)phenyl), referred to as N3. N1, N2, N3 and B form BNF-1, BNF-2 and BNF-3 materials with gradually increasing Lewis acidity. The monomer molecule B effectively generates BNF materials through B←N with N1, N2 and N3 in the solution, forming a two-dimensional sheet structure. Compared with the self-assembly of monomers, this sheet material has fluorescent color change characteristics and stimulant response. It further broadens the scope of the force of BNF two-dimensional materials, has potential application prospects in the fields of fluorescence sensing, fluorescence anti-counterfeiting, etc., and provides a new strategy for the preparation of two-dimensional BNF materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a solid fluorescence test diagram of the two-dimensional materials BNF-1, BNF-2 and BNF-3 of the present invention;

[0033] Figure 2 is the hydrogen nuclear magnetic resonance spectrum of the monomer molecule B involved in the present invention;

[0034] Figure 3 is the PXRD pattern of the two-dimensional materials BNF-1, BNF-2 and BNF-3 of the present invention;

[0035] Figure 4 It is the TEM electron microscope image of the two-dimensional materials BNF-1, BNF-2 and BNF-3 of the present invention. DETAILED DESCRIPTION

[0036] The principles and features of the present invention are described below in conjunction with the accompanying drawings. The examples given are only used to explain the present invention and are not intended to limit the scope of the present invention. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used in the specification of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0037] Embodiment 1:

[0038] A method for preparing a BNF two-dimensional material based on B←N dynamic covalent bond interaction, the specific steps are as follows:

[0039] Step 1: 2.3 g of 5-bromoresorcinol, 4.2 g of 3-ethylphenol, and 5.8 g of potassium carbonate were added to a 25 mL Schlenk bottle in sequence, 15 mL of N-methylpyrrolidone was added under nitrogen and stirred evenly, stirred at 180 ° C for 2 hours, heated to 190 ° C and continued to react for 2 hours, cooled to room temperature after the reaction, diluted with ethyl acetate, and then extracted with water and ethyl acetate for three times, anhydrous sodium sulfate was added to the combined organic extracts for drying, and the solvent was removed by rotary evaporator to obtain a crude product. The crude product was purified by column chromatography filled with silica gel, wherein the eluent was petroleum ether, and 3.5 g of 3,3'-((2,5-dibromo-1,3-phenyl)bis(oxy))bis(ethylbenzene) was purified as a colorless oily liquid with a yield of 86.9%.

[0040] Step 2: Add 2.3 g of 3,3'-((2,5-dibromo-1,3-phenyl)bis(oxy))bis(ethylbenzene) into a Schlenk bottle, add 15 mL of ultra-dry xylene dried over 5A molecular sieves and 2 mL of n-butyl lithium (2.3 mol / L) in a nitrogen and ice bath environment, then return to room temperature to react for 1-2 hours, then add 1.2 g of boron tribromide in an ice bath environment, keep the ice bath, react for 1-2 hours, maintain the temperature, and then slowly add 0.7 g of N,N-diisopropylethylamine, then heat to 130°C for 18 hours. After the reaction is completed, cool to room temperature and use a rotary evaporator to evaporate the mixture. The solvent was removed by a ventilator, and the mixture was extracted with a saturated sodium acetate solution and dichloromethane for 2-3 times. Anhydrous sodium sulfate was added to dry the combined organic extracts. The solvent was removed by a rotary evaporator to obtain a crude product, which was purified by column chromatography filled with silica gel, wherein the eluent was petroleum ether. The obtained product was washed with 100 mL of methanol for 3 times, and the washed solid was placed in a vacuum environment at 50-60° C. for 12-24 hours and then cooled to room temperature to obtain 0.83 g of 3,3'-((2,5-dibromo-1,3-phenyl)bis(oxy))bis(ethylbenzene) as a white solid with a yield of 42.6%.

[0041] Step 3: 200 mg of 3,3'-((2,5-dibromo-1,3-phenyl)bis(oxy))bis(ethylbenzene), 97 mg of 1,4-bis(dodecyloxy)-2,5-diethynylbenzene, 70 mg of tetrakistriphenylphosphine palladium and 45 mg of cuprous iodide were added to a 25 mL Schlenk bottle, and 5 mL of tetrahydrofuran and 5 mL of diisopropylamine were added under a nitrogen atmosphere. The mixture was stirred at a constant temperature of 80°C under reflux for 24 h, and the reaction progress was monitored in real time by a thin layer chromatography spot plate. After the reaction was completed and cooled to room temperature, the solvent was evaporated at low pressure, 20 mL of dichloromethane was added and filtered, the filter residue was washed twice with 50 mL of saturated ammonium chloride solution and 50 mL of methanol, and then placed in a vacuum environment at 50° C. for 12 h. The obtained solid was cooled to room temperature to obtain 306 mg of the target product monomer molecule B, which is specifically 7,7″-((2,5-dioctyl-1,4-phenyl)bis(acetylene-2,1-diyl))bis(3,11-diethyl-5,9-dioxy-13b-boronaphtho[3,2,1-de]anthracene), a yellow solid, with a yield of 62.3%.

[0042] The H NMR spectrum of monomer molecule B is shown in Figure 2 .

[0043] Step 4: In a molar ratio of [B]:[N1,N2,N3]=3:2, appropriate amounts of monomer molecules B and 4,4'-(5'-(4-(4-pyridyl)phenyl)-[1,1':3',1"-terphenyl]-4,4"-diyl)bipyridine, tris(4-(4-pyridyl)phenyl)amine and tris(4-(1H-imidazole-1-yl)phenyl) were placed in a 25 mL eggplant-shaped bottle, 10 mL of o-dichlorobenzene was added, and the mixture was heated to 150 °C for 24 h. After the reaction, the mixture was cooled to room temperature and placed in an ice bath for 1 h to obtain BNF-1, BNF-2 and BNF-3 two-dimensional materials, i.e., BNF two-dimensional materials based on B←N dynamic covalent bond interactions.

[0044] The solid fluorescence of BNF-1, BNF-2 and BNF-3 two-dimensional materials was tested, and the test results were blue, yellow and blue, respectively. Figure 1 .

[0045] PXRD results of BNF-1, BNF-2 and BNF-3 2D materials are shown in Figure 3 , it can be seen that the crystallinity of BNF-1, BNF-2 and BNF-3 two-dimensional materials is good.

[0046] TEM images of BNF-1, BNF-2 and BNF-3 two-dimensional materials are shown in Figure 4 , it can be seen that the three prepared BNF materials present a two-dimensional lamellar structure.

[0047] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing BNF two-dimensional materials based on B←N dynamic covalent bond interaction, characterized in that: The specific steps are as follows: First, the monomer molecule 7,7"-((2,5-docosyl-1,4-phenyl)bis(ethynyl-2,1-diyl))bis(3,11-diethyl-5,9-dioxy-13b-boronaphtho[3,2,1-de]anthracene) was synthesized. The synthesis route is as follows: Secondly, the monomer molecule 7,7"-((2,5-docosyl-1,4-phenyl)bis(ethynyl-2,1-diyl))bis(3,11-diethyl-5,9-dioxy-13b-boronaphtho[3,2,1-de]anthracene) (abbreviated as B) was reacted with 4,4'-(5'-(4-(4-pyridyl)phenyl)-[1,1':3',1"-terphenyl]-4,4"-diyl)bipyridine (abbreviated as N1), tris(4-(4-pyridyl)phenyl)amine (abbreviated as N2) and tris(4-(1H-imidazol-1-yl)phenyl)amine (abbreviated as N3) to prepare BNF-1 two-dimensional material, BNF-2 two-dimensional material and BNF-3 two-dimensional material respectively; The structural formula of the 4,4'-(5'-(4-(4-pyridyl)phenyl)-[1,1':3',1"-terphenyl]-4,4"-diyl)bipyridine is: The structural formula of the tri(4-(4-pyridyl)phenyl)amine is: The structural formula of the tris(4-(1H-imidazole-1-yl)phenyl)amine is:

2. The method for preparing the BNF two-dimensional material based on B←N dynamic covalent bond interaction according to claim 1, characterized in that: The specific steps of the synthesis method of the monomer molecule 7,7"-((2,5-docosyl-1,4-phenyl)bis(acetylene-2,1-diyl))bis(3,11-diethyl-5,9-dioxy-13b-boronaphtho[3,2,1-de]anthracene) are as follows: Step 1: 2,5-dibromo-1,3-difluorobenzene, 3-ethylphenol and potassium carbonate are added to a Schlenk bottle in proportion, and then a solvent N-methylpyrrolidone is added under a nitrogen environment. After stirring at 175-185° C. for 2-3 hours, the temperature is raised to 190-195° C. and stirred for another 2-3 hours; after the reaction is completed and cooled to room temperature, ethyl acetate is added for dilution, and then the reaction mixture is extracted with water and ethyl acetate for 2-3 times, and then anhydrous sodium sulfate is added to dry the combined organic extracts, and the solvent is removed by a rotary evaporator to obtain a crude product, and then the crude product is purified to obtain product 1, and product 1 is specifically 3,3'-((2,5-dibromo-1,3-phenyl)bis(oxy))bis(ethylbenzene); Step 2: Add product 1 to a Schlenk bottle, add xylene and n-butyl lithium in sequence under nitrogen and ice bath conditions, then return to room temperature for reaction for 1-2 hours, then add boron tribromide under ice bath conditions, keep ice bath, react for 1-2 hours, keep this temperature, then slowly add N,N-diisopropylethylamine, then raise the temperature to 130-140° C., after the reaction is completed and cooled to room temperature, remove the solvent with a rotary evaporator, extract the mixture with saturated sodium acetate solution and dichloromethane 2-3 times, add anhydrous sodium sulfate to dry the combined organic extracts, remove the solvent with a rotary evaporator to obtain a crude product, and then purify the crude product to obtain product 2, which is specifically 3,3'-((2,5-dibromo-1,3-phenyl)bis(oxy))bis(ethylbenzene); Step 3: 1,4-bis(dodecyloxy)-2,5-diethynylbenzene, product 2, tetratriphenylphosphine palladium and cuprous iodide are added to a container in proportion, and solvents diisopropylamine and tetrahydrofuran are added to fully dissolve under a nitrogen atmosphere, and stirred at a constant temperature of 75-80°C for 12-24 hours. After the reaction is completed and cooled to room temperature, the solvents diisopropylamine and tetrahydrofuran are removed by low-pressure evaporation, and then dichloromethane is added, and the filter residue is filtered out, and the filter residue is washed with saturated ammonium chloride solution and methanol for 2-4 times to obtain a crude product, which is then placed in a vacuum environment of 50-60°C for 12-24 hours, and the obtained solid is cooled to room temperature to obtain the target product B. Product B is specifically a monomer molecule 7,7"-((2,5-dodecyl-1,4-phenyl)bis(acetylene-2,1-diyl))bis(3,11-diethyl-5,9-dioxy-13b-boronaphtho[3,2,1-de]anthracene).

3. The method for preparing the BNF two-dimensional material based on B←N dynamic covalent bond interaction according to claim 2, characterized in that: In step 1, 2,5-dibromo-1,3-difluorobenzene, 3-ethylphenol and potassium carbonate are added in a molar ratio of 1:4:5; the amount of N-methylpyrrolidone added is 10-20 mL; the crude product is purified by column chromatography filled with silica gel, and the eluent is petroleum ether.

4. The method for preparing the BNF two-dimensional material based on B←N dynamic covalent bond interaction according to claim 2, characterized in that: In step 2, product 1, n-butyl lithium, boron tribromide and N,N-diisopropylethylamine are added in a molar ratio of 2:2:3:3; the volume of xylene added is 10-20 mL; and the time for adding boron tribromide and N,N-diisopropylethylamine dropwise to the reaction mixture is controlled to be more than 5 minutes.

5. The method for preparing the BNF two-dimensional material based on B←N dynamic covalent bond interaction according to claim 2, characterized in that: In step 2, the crude product is purified by column chromatography using silica gel as filling and petroleum ether as eluent, and then washed with methanol 2-3 times. The washed solid is placed in a vacuum environment at 50-60° C. for 12-24 hours and then cooled to room temperature.

6. The method for preparing the BNF two-dimensional material based on B←N dynamic covalent bond interaction according to claim 2, characterized in that: In step 3, 1,4-bis(dodecyloxy)-2,5-diethynylbenzene, product 2, tetrakistriphenylphosphine palladium and cuprous iodide are added in a molar ratio of 4:6:1:2; the ratio of solvent diisopropylamine and tetrahydrofuran is 1:1, and the total volume is 10-15 mL.

7. The method for preparing the BNF two-dimensional material based on B←N dynamic covalent bond interaction according to claim 2, characterized in that: In step 2, the xylene and N,N-diisopropylethylamine are both dried over 5A molecular sieves; and the solution is heated in a constant temperature oil bath.

8. The method for preparing the BNF two-dimensional material based on B←N dynamic covalent bond interaction according to claim 1, characterized in that: The preparation method of the BNF-1 two-dimensional material is specifically as follows: dissolving monomer molecules 7,7"-((2,5-docosyl-1,4-phenyl)bis(acetylene-2,1-diyl))bis(3,11-diethyl-5,9-dioxy-13b-boronaphtho[3,2,1-de]anthracene) and 4,4'-(5'-(4-(4-pyridyl)phenyl)-[1,1':3',1"-terphenyl]-4,4"-diyl)bipyridine in proportion in 5-10 mL of o-dichlorobenzene, heating to 150-160° C. for reaction for 24 h, cooling to room temperature and ice bathing for 1 h after the reaction, and filtering to obtain the filter residue, which is the BNF-1 two-dimensional material; The preparation method of the BNF-2 two-dimensional material is specifically as follows: dissolving monomer molecules 7,7″-((2,5-dioctyl-1,4-phenyl)bis(acetylene-2,1-diyl))bis(3,11-diethyl-5,9-dioxy-13b-boronaphtho[3,2,1-de]anthracene) and tri(4-(4-pyridyl)phenyl)amine in proportion in 5-10 mL of o-dichlorobenzene, heating to 150-160° C. for reaction for 24 h, cooling to room temperature and ice bathing for 1 h after the reaction, and filtering to obtain the filter residue, which is the BNF-2 two-dimensional material; The preparation method of the BNF-3 two-dimensional material is specifically as follows: dissolving the monomer molecules 7,7"-((2,5-didecyl-1,4-phenyl)bis(acetylene-2,1-diyl))bis(3,11-diethyl-5,9-dioxy-13b-boronaphtho[3,2,1-de]anthracene) and tri(4-(1H-imidazole-1-yl)phenyl)amine in proportion in 5-10 mL of o-dichlorobenzene, heating to 150-160°C for reaction for 24 hours, cooling to room temperature and placing in an ice bath for 1 hour after the reaction is completed, and filtering to obtain the filter residue, which is the BNF-3 two-dimensional material.

9. The method for preparing the BNF two-dimensional material based on B←N dynamic covalent bond interaction according to claim 8, characterized in that: The molar ratio of the monomer molecules 7,7″-((2,5-docosyl-1,4-phenyl)bis(ethynyl-2,1-diyl))bis(3,11-diethyl-5,9-dioxy-13b-boronaphtho[3,2,1-de]anthracene) to 4,4′-(5′-(4-(4-pyridyl)phenyl)-[1,1′:3′,1″-terphenyl]-4,4″-diyl)bipyridine is 3:2; The molar ratio of the monomer molecule 7,7″-((2,5-docosyl-1,4-phenyl)bis(ethynyl-2,1-diyl))bis(3,11-diethyl-5,9-dioxo-13b-boronaphtho[3,2,1-de]anthracene) to tri(4-(4-pyridyl)phenyl)amine is 3:2; The molar ratio of the monomer molecule 7,7″-((2,5-docosyl-1,4-phenyl)bis(acetylene-2,1-diyl))bis(3,11-diethyl-5,9-dioxy-13b-boronaphtho[3,2,1-de]anthracene) to tri(4-(1H-imidazol-1-yl)phenyl)amine is 3:2.

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