A method for the synthesis of benzoporphyrin molecules for hydrogen storage

Abstract

The application provides a synthesis method of a benzoparacyclophane molecule for hydrogen storage, and belongs to the technical field of hydrogen storage of organic heterocyclic aromatic hydrocarbon molecules. The synthesis method prepares the benzoparacyclophane molecule by taking an N1 molecule as an initial reactant; wherein, the chemical structural formula of the N1 molecule is: and the chemical structural formula of the benzoparacyclophane molecule is: by taking the N1 molecule as the initial reactant, the application reduces by-products in the reaction process, greatly improves the yield of the intermediate product and the reaction success rate, and finally realizes the great improvement of the synthesis yield, yield and efficiency of the benzoparacyclophane molecule.

Description

Technical Field

[0001] This application belongs to the field of hydrogen storage technology for organic heterocyclic aromatic hydrocarbon molecules, specifically relating to a method for synthesizing benzo[a]-p-dipyrrole molecules for hydrogen storage. Background Technology

[0002] The benzo[a]-dipyrrole molecule described in this application is an organic heterocyclic aromatic hydrocarbon molecule that can be used for hydrogen storage. Articles such as "Synthesis and Photoelectric Properties of Novel Narrow Bandgap Polysaccharide Cyanide" mention that the benzo[a]-dipyrrole molecule can be applied to the field of solar cells; however, the synthesis process of this molecule exhibits shortcomings such as low yield, low production volume, and slow efficiency, making it unable to meet the needs of industrial production and limiting its practical application. Summary of the Invention

[0003] This application provides a method for synthesizing benzo[a]-p-dipyrrole molecules for hydrogen storage, thereby solving the current problem. The synthesis process exhibits problems such as low yield, low output, and slow efficiency.

[0004] This application provides a method for synthesizing benzo[a]-dipyrrole molecules for hydrogen storage, wherein the method uses N1 molecules as initial reactants to prepare benzo[a]-dipyrrole molecules;

[0005] The chemical structural formula of the N1 molecule is as follows:

[0006]

[0007] The chemical structural formula of the benzo[a]-dipyrrole molecule is as follows:

[0008]

[0009] Preferably, the synthetic method for preparing benzene-p-dipyrrole molecules using N1 molecules as initial reactants includes:

[0010] Step 1: In an ice-water bath, dissolve the N1 molecule in concentrated sulfuric acid, then add concentrated nitric acid dropwise to obtain a solidified first reaction solution. After cooling for 5-20 minutes, perform the first post-treatment to obtain the N2 molecule; wherein, the chemical structural formula of the N2 molecule is:

[0011]

[0012] Step 2: Under nitrogen protection, the N2 molecules are dissolved in N,N-dimethylformamide. When the temperature reaches 80–100°C, N,N-dimethylformamide diethyl acetal is added. The temperature is then raised to 110–130°C, and the reaction is carried out for 20–30 hours. After cooling to room temperature, a second reaction solution is obtained. The second reaction solution is filtered to obtain N3 molecules. The chemical structural formula of the N3 molecule is:

[0013]

[0014] Step 3: dissolving the N3 molecule in tetrahydrofuran to obtain a third reaction liquid, adding Pd / C catalyst with 10% noble metal mass content, and reacting with hydrogen gas under preset conditions until the third reaction liquid no longer absorbs hydrogen gas to obtain a fourth reaction liquid, and performing second post-treatment on the fourth reaction liquid to obtain the benzoparacyclophane molecule.

[0015] Preferably, in the step 1, 2.0-3.0 ml of the concentrated sulfuric acid and 0.6-1.5 ml of the concentrated nitric acid are needed for every 1.0 ml of the N1 molecule.

[0016] Preferably, in the step 1, the first post-treatment comprises:

[0017] The solidified first reaction liquid is washed with deionized water to remove residual concentrated sulfuric acid and concentrated nitric acid to obtain a solid;

[0018] The solid is dried in a vacuum drying box at 60°C for 3-6 h and then recrystallized to obtain the N2 molecule.

[0019] Preferably, in the step 2, 2.0-4.0 ml of the N,N-dimethylformamide and 3.0-4.0 ml of N,N-dimethylformamide diethyl acetal are needed for every 1.0 g of the N2 molecule.

[0020] Preferably, in the step 2, the second reaction liquid is filtered to obtain the N3 molecule, and the filtering comprises natural filtering or vacuum filtration.

[0021] Preferably, in the step 3, 1.0-3.0 ml of the tetrahydrofuran and 0.1-0.5 g of the Pd / C catalyst with 10% noble metal mass content are needed for every 1.0 g of the N3 molecule.

[0022] Preferably, in the step 3, the preset conditions comprise:

[0023] The reaction is performed in a complete hydrogen gas atmosphere, and the reaction temperature is 25-30°C.

[0024] Preferably, in the step 3, the second post-treatment comprises:

[0025] The fourth reaction liquid is purified by silica gel chromatography column using dichloromethane and petroleum ether to obtain the benzoparacyclophane molecule.

[0026] Compared with the prior art, the present application has the following advantages:

[0027] (1) the prior art uses 1,3-xylene as the initial reaction substrate, so that the reaction product contains a large amount of 1,3-dimethyl-2,5-dinitrobenzene and incompletely reacted 1,3-dimethyl-4-nitrobenzene and 1,3-dimethyl-5-nitrobenzene, and the final desired reaction product The selectivity is about 60%, and due to the structural similarity of the by-products and , it is difficult to purify them, thereby affecting the yield of the next step. The present application uses instead of 1,3-xylene as the initial reactant, which does not produce the above-mentioned by-products during the reaction, avoids the occurrence of the above-mentioned problems, greatly improves the yield of , and makes the yield reach more than 95%, and the success rate of step 1 reaches 100%;

[0028] (2) the prior art removes the reaction solvent N,N-dimethylformamide in step 2 by low-pressure distillation, which easily causes the product to splash during application, causing a large amount of waste and not purifying the product of step 2, thereby reducing the reaction yield of step 3 (not more than 20%). The present application uses natural filtration or vacuum filtration to remove the reaction solvent N,N-dimethylformamide in step 2 and a small amount of impurities dissolved in N,N-dimethylformamide, which does not cause the product to splash during operation, avoids the waste of the product of step 2 and can purify the reaction product of step 2, is simple and convenient to operate, greatly reduces the influence of other unnecessary impurities on the reaction yield of step 3, and can make the yield of the final purified product benzoparadipyrrone molecule stable at more than 70%;

[0029] (3) the prior art selects room temperature as the reaction temperature of step 3, and does not indicate a more appropriate temperature range, so that the reaction yield and reaction time of step 3 are uncertain. The present application determines through experiments that keeping the reaction temperature of step 3 in the range of 25-30°C can make the reaction of step 3 complete within 48h, and the yield before purification reaches more than 80%, so that the yield of the final purified product benzoparadipyrrone molecule is stable at more than 70%;

[0030] (4) in step 3, the prior art first introduces hydrogen gas and then adds Pd / C catalyst in a closed environment after dissolving the product of step 2 in tetrahydrofuran, which is difficult to operate and easy to introduce air, which can affect the reaction of step 3. The present application chooses to add Pd / C catalyst first and then react in a complete hydrogen atmosphere, which avoids the introduction of air and reduces the operation difficulty of step 3, so that the yield of the final purified product benzoparadipyrrone molecule is stable at more than 70%;

[0031] (5)Optimization of the ratio of reactants, catalysts and solvents, reducing the loss of product in the reaction process and purification process, so that the yield of the final product benzoparacyclophane is more than 70%;

[0032] (6)The synthesis method provided by the application can be scaled up in the same proportion according to the demand for products, and the reaction process is stable and controllable. BRIEF DESCRIPTION OF DRAWINGS

[0033] Figure 1 The synthesis scheme of the reaction end product M1 molecule in the embodiment of the application is shown in the following formula (1) :

[0034] Figure 2 The synthesis scheme of the reaction end product M1 molecule in the embodiment of the application is shown in the following formula (1) :

[0035] Figure 3 The nuclear magnetic resonance hydrogen spectrum of the step 1 reaction product N2 molecule in the embodiment of the application is shown in the following formula (2) :

[0036] Figure 4 The nuclear magnetic resonance hydrogen spectrum of the step 2 reaction product N3 molecule in the embodiment of the application is shown in the following formula (3) :

[0037] Figure 5 The nuclear magnetic resonance hydrogen spectrum of the step 3 reaction product M1 molecule in the embodiment of the application is shown in the following formula (4). DETAILED DESCRIPTION

[0038] In order to make the above-mentioned purposes, features and advantages of the application more obvious and easy to understand, the preferred embodiments of the application will be described in detail below. It should be understood that the following examples are given only for the purpose of illustration and are not intended to limit the scope of the application. Those skilled in the art can make various modifications and substitutions to the application without departing from the spirit and principles of the application. The materials, reagents, etc. used in the following examples, if not specifically stated, can be obtained from commercial channels.

[0039] The applicant found that in the synthesis process of the molecule benzoparacyclophane shown in the following formula (1), the problems of low yield, small output and slow efficiency are particularly obvious. Therefore, the synthesis process of the benzoparacyclophane molecule of the chemical structure is optimized in the application.

[0040]

[0041] Referring to Figure 1 The synthesis scheme of the reaction end product M1 molecule in the embodiment of the application is shown in the following formula (1) : Figure 1 The synthesis scheme of the reaction end product M1 molecule in the embodiment of the application is shown in the following formula (1) : The synthesis method provided by the application is a synthesis method for a benzoparacyclophane molecule for hydrogen storage, which is prepared from an N1 molecule as an initial reactant.

[0042] The chemical structural formula of the N1 molecule is as follows:

[0043]

[0044] The chemical structural formula of the benzoparacyclophane molecule is as follows:

[0045]

[0046] In this embodiment, the present application uses instead of 1,3-dimethylbenzene as the initial reactant, avoiding the generation of a large amount of by-products, such as 1,3-dimethyl-2,5-dinitrobenzene, incompletely reacted 1,3-dimethyl-4-nitrobenzene and 1,3-dimethyl-5-nitrobenzene, greatly improving the yield of the reaction product to more than 95%, and making the success rate of the reaction of step 1 reach 100%. The above-mentioned by-products have structural similarity with the reaction product, making the reaction product difficult to be purified, which will affect the yield of the next step reaction. The present application selects as the initial reactant, and the above-mentioned by-products are not generated in the reaction process, avoiding the generation of the above-mentioned problems and further improving the yield of the next step reaction.

[0047] For example, the N1 molecule is dissolved in concentrated sulfuric acid in an ice water bath, and concentrated nitric acid is added dropwise until the reaction solution is frozen. Deionized water is used for washing until the acid is completely removed. After the solid is dried and recrystallized, the N2 molecule is obtained. Under the protection of nitrogen, the N2 molecule is dissolved in N,N-dimethylformamide, and the temperature is raised to 80°C. N,N-dimethylformamide diethyl acetal is added, and then the temperature is raised to 120°C. After reacting for 24 h, the solvent is removed by low-pressure distillation to obtain a mixed crude product of N3 molecules. The N3 molecule crude product is dissolved in tetrahydrofuran, and hydrogen is introduced. Then, Pd / C catalyst is added in a sealed environment. The reaction temperature is set to room temperature. After the reaction is complete, dichloromethane and petroleum ether are used for purification by a silica gel chromatographic column to obtain the M1 molecule.

[0048] Referring to FIG. 1, a specific synthesis path scheme of the final reaction product M1 molecule in the embodiment of the present application is shown. As shown in FIG. 2, the specific synthesis scheme includes: Figure 2 Figure 2

[0049] Step 1: In an ice water bath, the N1 molecule is dissolved in concentrated sulfuric acid, and concentrated nitric acid is added dropwise to obtain a frozen first reaction solution. After cooling for 5-20 min, the first post-treatment is performed to obtain the N2 molecule. The chemical structural formula of the N2 molecule is as follows:

[0050]

[0051] Referring to FIG. 1, a specific synthesis path scheme of the final reaction product M1 molecule in the embodiment of the present application is shown. As shown in FIG. 2, the specific synthesis scheme includes:​​Figure 3 As shown, the nuclear magnetic resonance hydrogen spectrum of the above-mentioned N2 molecule, 1H NMR, d6-DMSO: 8.59 (1H), 7.67 (1H), 2.48 (6H).

[0052] In this embodiment, 2.0-3.0 ml of concentrated sulfuric acid and 0.6-1.5 ml of concentrated nitric acid are needed per 1.0 ml of N1 molecule. When the amount of concentrated sulfuric acid is less than 2 ml, the N1 molecule cannot be completely dissolved; when the amount of concentrated sulfuric acid is 3 ml, the N1 molecule has been completely dissolved and there is no need to add additional concentrated sulfuric acid. When the amount of concentrated nitric acid is less than 0.6 ml, the reaction cannot be completed; when the amount of concentrated nitric acid is 1.5 ml, the reaction has been completely completed and there is no need to add additional concentrated nitric acid.

[0053] The first post-treatment includes:

[0054] The coagulated first reaction liquid is washed with deionized water to remove residual concentrated sulfuric acid and concentrated nitric acid, thereby obtaining a solid.

[0055] The solid is dried in a vacuum drying oven at 60°C for 3-6 h and then recrystallized to obtain the N2 molecule.

[0056] In specific implementation, the amount of deionized water can be added according to specific conditions.

[0057] Step 2: Under nitrogen protection, the N2 molecule is dissolved in N,N-dimethylformamide, and when the temperature rises to 80-100°C, N,N-dimethylformamide diethyl acetal is added, and then the temperature is raised to 110-130°C. After 20-30 h of reaction, the temperature is lowered to room temperature to obtain a second reaction liquid. The second reaction liquid is filtered to obtain an N3 molecule; the chemical structural formula of the N3 molecule is:

[0058]

[0059] Reference Figure 4 As shown, the nuclear magnetic resonance hydrogen spectrum of the above-mentioned N3 molecule, 1H NMR, d6-DMSO: 8.52 (1H), 7.70 (d, 2H), 7.56 (1H), 5.87 (d, 2H), 2.96 (12H).

[0060] In this embodiment, when the N2 molecule is dissolved in N,N-dimethylformamide, the temperature needs to be raised to 80-100°C. When the temperature is lower than 80°C, the dissolution speed of the N2 molecule is slow; when the temperature is higher than 100°C, the pressure in the reactor is too high due to gas expansion, and the reaction cannot continue.

[0061] After adding N,N-dimethylformamide diethyl acetal, the temperature needs to be raised to 110-130°C. When the temperature is lower than 110°C, the reaction efficiency is lower; when the temperature is higher than 130°C, the reactor pressure is too high due to gas expansion, which causes safety hazards.

[0062] In this embodiment, for every 1.0 g of N2 molecules, 2.0-4.0 ml of N,N-dimethylformamide and 3.0-4.0 ml of N,N-dimethylformamide diethyl acetal are needed. When the amount of N,N-dimethylformamide is less than 2 ml, the N2 molecule dissolves slowly; when the amount of N,N-dimethylformamide is 4 ml, the N2 molecule has already been completely dissolved, and there is no need to add additional N,N-dimethylformamide. When the amount of N,N-dimethylformamide diethyl acetal is less than 3.0 ml, the reaction conversion rate is lower; when the amount of N,N-dimethylformamide diethyl acetal is 4.0 ml, the reaction has already been completely complete, and there is no need to add additional N,N-dimethylformamide diethyl acetal.

[0063] In this embodiment, natural filtration or vacuum filtration is selected to filter the second reaction liquid, which is simple and convenient. In the prior art, low-pressure distillation is often selected to remove the reaction solvent N,N-dimethylformamide in step 2 and the impurities dissolved in N,N-dimethylformamide, which easily causes the product to splash during application, resulting in a large amount of waste and not purifying the product of step 2, so that the reaction yield of step 3 is lower (not more than 20%). In this application, natural filtration or vacuum filtration is selected instead of low-pressure distillation to remove the reaction solvent N,N-dimethylformamide in step 2 and a small amount of impurities dissolved in N,N-dimethylformamide. During the operation process, the product will not splash, which can not only avoid the waste of the product of step 2, but also purify it, greatly reducing the influence of other unnecessary impurities on the reaction yield of step 3, so that the molecular yield of the final purified product of benzoparadipyrrole can be stabilized at more than 70%.

[0064] Step 3: Dissolve the N3 molecules in tetrahydrofuran to obtain a third reaction liquid, add a Pd / C catalyst with a noble metal mass content of 10%, and react with hydrogen gas under preset conditions until the third reaction liquid no longer absorbs hydrogen gas to obtain a fourth reaction liquid. The fourth reaction liquid is subjected to a second post-treatment to obtain the benzoparadipyrrole molecules.

[0065] Referring to Figure 5 As shown in the figure, the nuclear magnetic resonance hydrogen spectrum of the above-mentioned benzoparadipyrrole molecules is shown, 1H NMR, d6-DMSO: 10.49 (2H), 7.57 (1H), 7.28 (1H), 7.18 (2H), 6.33 (2H).

[0066] In the embodiment, 1.0-3.0 ml of tetrahydrofuran and 0.1-0.5 g of Pd / C catalyst with a noble metal content of 10% are needed per 1.0 g of N3 molecules. When the amount of tetrahydrofuran is less than 1 ml, N3 molecules cannot be completely dissolved; when the amount of tetrahydrofuran is 3 ml, N3 molecules have been completely dissolved, and no additional tetrahydrofuran needs to be added. When the amount of Pd / C catalyst is less than 0.1 g, the reaction efficiency is relatively low; when the amount of Pd / C catalyst is 0.5 g, the reaction efficiency has met the current reaction requirements, and no additional Pd / C catalyst needs to be added.

[0067] The preset condition includes:

[0068] The reaction is performed in a complete hydrogen atmosphere, and the reaction temperature is 25-30°C.

[0069] In the embodiment, when the reaction temperature is lower than 25°C, the reaction efficiency is too low. According to experiments conducted by the applicant, the reaction temperature is kept in the range of 25-30°C, so that the reaction in step 3 is completely reacted within 48 h, the yield before purification is more than 80%, and the yield of the final product, benzoparadipyrrone molecules, is stably more than 70% after purification.

[0070] The second post-treatment includes:

[0071] The fourth reaction solution is purified by silica gel chromatography column using dichloromethane and petroleum ether to obtain the benzoparadipyrrone molecules.

[0072] In the embodiment, after the third reaction solution is obtained, the Pd / C catalyst is added first, and then hydrogen is introduced for reaction, which is different from the prior art in which hydrogen is introduced first, and then the Pd / C catalyst is added in a sealed environment. The operation difficulty is reduced, and the influence of air on the reaction in step 3 is avoided.

[0073] In specific implementation, the air can be replaced by argon or nitrogen before hydrogen is introduced, so as to ensure that there is no air remaining in the reaction environment.

[0074] On the basis of common sense in the art, the above-mentioned preferred conditions can be combined with each other to obtain the specific embodiments.

[0075] Embodiment 1

[0076] Step 1: In an ice water bath, 10.0 ml of N1 molecules are dissolved in 20.0 ml of concentrated sulfuric acid, and then 6.0 ml of concentrated nitric acid is added to obtain a solidified first reaction solution. After being cooled for 10 min, the solidified first reaction solution is washed with deionized water to remove residual concentrated sulfuric acid and concentrated nitric acid, and then a solid is obtained. The solid is dried in a vacuum drying box at 60°C for 6 h and then recrystallized to obtain about 13.8 g of N2 molecules.

[0077] Step 2: Dissolve 13.8 g of N2molecule in 27.6 ml of N,N-dimethylformamide under nitrogen protection, wait for the temperature to rise to 80°C, add 41.4 ml of N,N-dimethylformamide diethyl acetal, then raise the temperature to 110°C, and after 20 h of reaction, lower the temperature to room temperature to obtain a second reaction liquid. After natural filtration of the second reaction liquid, about 17.7 g of N3molecule is obtained.

[0078] Step 3: Dissolve 17.7 g of N3molecule in 17.7 ml of tetrahydrofuran to obtain a third reaction liquid. Add 1.77 g of Pd / C catalyst with a noble metal mass content of 10%. Set the reaction temperature to 25°C. React under a complete hydrogen atmosphere until the third reaction liquid no longer absorbs hydrogen to obtain a fourth reaction liquid. Purify the fourth reaction liquid using dichloromethane and petroleum ether through a silica gel chromatographic column to obtain about 7.5 g of benzoparacyclophane molecule.

[0079] Example 2

[0080] Step 1: Dissolve 5.0 ml of N1molecule in 12.0 ml of concentrated sulfuric acid in an ice water bath, then add 5.0 ml of concentrated nitric acid to obtain a solidified first reaction liquid. After cooling for 10 min, wash the solidified first reaction liquid with deionized water to remove residual concentrated sulfuric acid and concentrated nitric acid, and obtain a solid. Dry the solid in a vacuum drying oven at 60°C for 4 h, then recrystallize to obtain about 7.1 g of N2molecule.

[0081] Step 2: Dissolve 7.1 g of N2molecule in 20.0 ml of N,N-dimethylformamide under nitrogen protection. Wait for the temperature to rise to 85°C, then add 22.0 ml of N,N-dimethylformamide diethyl acetal. Then raise the temperature to 115°C, and after 24 h of reaction, lower the temperature to room temperature to obtain a second reaction liquid. After natural filtration of the second reaction liquid, about 10.0 g of N3molecule is obtained.

[0082] Step 3: Dissolve 10.0 g of N3molecule in 15.0 ml of tetrahydrofuran to obtain a third reaction liquid. Add 2.2 g of Pd / C catalyst with a noble metal mass content of 10%. Set the reaction temperature to 26°C. React under a complete hydrogen atmosphere until the third reaction liquid no longer absorbs hydrogen to obtain a fourth reaction liquid. Purify the fourth reaction liquid using dichloromethane and petroleum ether through a silica gel chromatographic column to obtain about 4.2 g of benzoparacyclophane molecule.

[0083] Example 3

[0084] Step 1 : Dissolve 1.2 ml of N1 molecules in 3.0 ml of concentrated sulfuric acid, then add 1.5 ml of concentrated nitric acid dropwise to obtain a solidified first reaction solution, and after cooling for 5 min, wash the solidified first reaction solution with deionized water to remove residual concentrated sulfuric acid and concentrated nitric acid, and obtain a solid. Dry the solid in a vacuum drying oven at 60°C for 3 h, and then recrystallize to obtain about 1.67 g of N2 molecules.

[0085] Step 2: Dissolve 1.67 g of N2 molecules in 5.0 ml of N,N-dimethylformamide under nitrogen protection, and when the temperature rises to 90°C, add 5.8 ml of N,N-dimethylformamide diethyl acetal, then heat to 120°C, and after 20 h of reaction, cool to room temperature to obtain a second reaction solution. After natural filtration of the second reaction solution, about 2.43 g of N3 molecules are obtained.

[0086] Step 3: Dissolve 2.43 g of N3 molecules in 5.0 ml of tetrahydrofuran to obtain a third reaction solution, add 0.6 g of Pd / C catalyst with a noble metal mass content of 10%, set the reaction temperature to 25°C, and react under a complete hydrogen atmosphere until the third reaction solution no longer absorbs hydrogen to obtain a fourth reaction solution. Purify the fourth reaction solution using dichloromethane and petroleum ether through a silica gel chromatographic column to obtain about 1.3 g of benzoparacyclophane molecules.

[0087] Example 4

[0088] Step 1 : Dissolve 25.0 ml of N1 molecules in 3.0 ml of concentrated sulfuric acid in an ice water bath, then add 55.0 ml of concentrated nitric acid dropwise to obtain a solidified first reaction solution, and after cooling for 20 min, wash the solidified first reaction solution with deionized water to remove residual concentrated sulfuric acid and concentrated nitric acid, and obtain a solid. Dry the solid in a vacuum drying oven at 60°C for 6 h, and then recrystallize to obtain about 35.51 g of N2 molecules.

[0089] Step 2: Dissolve 35.51 g of N2 molecules in 90.0 ml of N,N-dimethylformamide under nitrogen protection, and when the temperature rises to 95°C, add 120.0 ml of N,N-dimethylformamide diethyl acetal, then heat to 125°C, and after 30 h of reaction, cool to room temperature to obtain a second reaction solution. After vacuum filtration of the second reaction solution, about 49.9 g of N3 molecules are obtained.

[0090] Step 3: Dissolve 49.9 g of N3 molecules in 80.0 ml of tetrahydrofuran to obtain a third reaction solution, add 15.5 g of Pd / C catalyst with a noble metal mass content of 10%, set the reaction temperature to 28°C, and react under a complete hydrogen atmosphere until the third reaction solution no longer absorbs hydrogen to obtain a fourth reaction solution. Purify the fourth reaction solution using dichloromethane and petroleum ether through a silica gel chromatographic column to obtain about 20.6 g of benzoparacyclophane molecules.

[0091] Example 5

[0092] Step 1 : In an ice water bath, 8.0 ml of N1 molecules were dissolved in 18.0 ml of concentrated sulfuric acid, and then 10.0 ml of concentrated nitric acid was added dropwise to obtain a solidified first reaction solution. After cooling for 10 min, the solidified first reaction solution was washed with deionized water to remove residual concentrated sulfuric acid and concentrated nitric acid, and a solid was obtained. The solid was dried in a vacuum drying oven at 60°C for 4 h and then recrystallized to obtain about 11.41 g of N2 molecules.

[0093] Step 2: Under nitrogen protection, 11.4 g of N2 molecules were dissolved in 35.0 ml of N,N-dimethylformamide, and the temperature was raised to 85°C. Then 40.0 ml of N,N-dimethylformamide diethyl acetal was added, and then the temperature was raised to 125°C. After 28 h of reaction, the temperature was lowered to room temperature to obtain a second reaction solution. The second reaction solution was vacuum filtered to obtain about 16.4 g of N3 molecules.

[0094] Step 3: 16.4 g of N3 molecules were dissolved in 26.0 ml of tetrahydrofuran to obtain a third reaction solution. 2.5 g of Pd / C catalyst with a noble metal mass content of 10% was added, and the reaction temperature was set to 30°C. The reaction was carried out under a complete hydrogen atmosphere until the third reaction solution no longer absorbed hydrogen to obtain a fourth reaction solution. The fourth reaction solution was purified using dichloromethane and petroleum ether through a silica gel chromatographic column to obtain about 7.0 g of benzoparacyclophane molecules.

[0095] Example 6

[0096] Step 1 : In an ice water bath, 13.0 ml of N1 molecules were dissolved in 32.0 ml of concentrated sulfuric acid, and then 15.0 ml of concentrated nitric acid was added dropwise to obtain a solidified first reaction solution. After cooling for 10 min, the solidified first reaction solution was washed with deionized water to remove residual concentrated sulfuric acid and concentrated nitric acid, and a solid was obtained. The solid was dried in a vacuum drying oven at 60°C for 4 h and then recrystallized to obtain about 18.4 g of N2 molecules.

[0097] Step 2: Under nitrogen protection, 18.4 g of N2 molecules were dissolved in 65.0 ml of N,N-dimethylformamide, and the temperature was raised to 90°C. Then 70.0 ml of N,N-dimethylformamide diethyl acetal was added, and then the temperature was raised to 115°C. After 24 h of reaction, the temperature was lowered to room temperature to obtain a second reaction solution. The second reaction solution was vacuum filtered to obtain about 25.5 g of N3 molecules.

[0098] Step 3: 20.7 g of N3 molecules were dissolved in 62.1 ml of tetrahydrofuran to obtain a third reaction solution, 10.35 g of Pd / C catalyst with a precious metal mass content of 10% was added, the reaction temperature was set to 30°C, and the reaction was carried out under a complete hydrogen atmosphere until the third reaction solution no longer absorbed hydrogen to obtain a fourth reaction solution, the fourth reaction solution was purified by silica gel chromatography column using dichloromethane and petroleum ether to obtain about 9.3 g of benzoparacyclophane molecules.

[0099] Example 7

[0100] Step 1: 10.0 ml of N1 molecules were dissolved in 30.0 ml of concentrated sulfuric acid in an ice water bath, and 15.0 ml of concentrated nitric acid was added dropwise to obtain a solidified first reaction solution, which was cooled for 10 min and then washed with deionized water to remove residual concentrated sulfuric acid and concentrated nitric acid, obtaining a solid, which was dried in a vacuum drying oven at 60°C for 6 h and then recrystallized to obtain about 14.4 g of N2 molecules.

[0101] Step 2: 14.4 g of N2 molecules were dissolved in 57.6 ml of N,N-dimethylformamide under nitrogen protection, and the temperature was raised to 100°C, 57.6 ml of N,N-dimethylformamide diethyl acetal was added, then the temperature was raised to 130°C, and the reaction was carried out for 30 h, then the temperature was lowered to room temperature to obtain a second reaction solution, which was vacuum filtered to obtain about 20.7 g of N3 molecules.

[0102] Step 3: 20.7 g of N3 molecules were dissolved in 62.1 ml of tetrahydrofuran to obtain a third reaction solution, 10.35 g of Pd / C catalyst with a precious metal mass content of 10% was added, the reaction temperature was set to 30°C, and the reaction was carried out under a complete hydrogen atmosphere until the third reaction solution no longer absorbed hydrogen to obtain a fourth reaction solution, the fourth reaction solution was purified by silica gel chromatography column using dichloromethane and petroleum ether to obtain about 9.3 g of benzoparacyclophane molecules.

[0103] For the method embodiments, they are all described as a series of action combinations for the sake of simple description, but those skilled in the art should know that the application is not limited by the order of the described actions, because according to the application, certain steps can be performed in other orders or simultaneously. Secondly, those skilled in the art should know that the embodiments described in the specification are all preferred embodiments, and the actions and components involved are not necessarily required by the application.

[0104] The synthesis method of the benzoparacyclophane molecule for hydrogen storage provided by the application is described in detail above, and specific examples are applied to the principle and implementation manner of the application. The above description of the examples is only used to help understand the method of the application and its core idea; at the same time, for those skilled in the art, according to the idea of the application, the specific implementation manner and application range will be changed, and the above description should not be understood as a limitation on the application.

Claims

1. A method for synthesizing benzo[a]-p-dipyrrole molecules for hydrogen storage, characterized in that, The synthetic method uses N1 molecules as initial reactants to prepare benzene-p-dipyrrole molecules; The chemical structural formula of the N1 molecule is as follows: The chemical structural formula of the benzo[a]-dipyrrole molecule is as follows: The synthetic method, which uses N1 molecules as initial reactants to prepare benzene-p-dipyrrole molecules, includes the following steps: Step 1: In an ice-water bath, 10.0 ml of the N1 molecules were dissolved in 30.0 ml of concentrated sulfuric acid, and then 15.0 ml of concentrated nitric acid was added dropwise to obtain a solidified first reaction solution. After cooling for 10 minutes, a first post-treatment was performed to obtain 14.4 g of N2 molecules. The first post-treatment included: washing the solidified first reaction solution with deionized water to remove residual concentrated sulfuric acid and concentrated nitric acid, obtaining a solid; drying the solid in a vacuum drying oven at 60°C for 6 hours, and then recrystallizing to obtain the N2 molecules. The yield of the N2 molecules was 97.3%, and the chemical structural formula of the N2 molecules was: Step 2: Under nitrogen protection, 14.4g of the N2 molecules were dissolved in 57.6ml of N,N-dimethylformamide. When the temperature reached 100℃, 57.6ml of N,N-dimethylformamide diethyl acetal was added, and the temperature was then raised to 130℃. After reacting for 30 hours, the mixture was cooled to room temperature to obtain a second reaction solution. The second reaction solution was filtered to obtain 20.7g of N3 molecules. The filtration included natural filtration or vacuum filtration. The yield of the N3 molecules was 89.6%, and the chemical structural formula of the N3 molecules was: Step 3: Dissolve 20.7g of the N3 molecules in 62.1ml of tetrahydrofuran to obtain the third reaction solution. Add 10.35g of Pd / C catalyst with a noble metal mass content of 10%. Set the reaction temperature to 30℃ and react under a completely hydrogen atmosphere until the third reaction solution no longer absorbs hydrogen to obtain the fourth reaction solution. Purify the fourth reaction solution using dichloromethane and petroleum ether via silica gel chromatography to obtain approximately 9.3g of benzene and p-dipyrrole molecules. The yield of the benzo[a]-dipyrrole molecule was 79%.

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