Organic compound 1, 3, 6, 8-tetra (m-aniline) pyrene, one-dimensional covalent organic framework and preparation method and application thereof

Abstract

The invention discloses an organic compound 1, 3, 6, 8-tetra (m-aniline) pyrene, a one-dimensional covalent organic framework and a preparation method and application thereof, and belongs to the field of materials. The one-dimensional covalent organic framework is prepared by taking 1, 3, 6, 8-tetra (m-aniline) pyrene (3-Py-NH2) as a building block and reacting the building block with 2, 2 '-bipyridine-5, 5'-diformaldehyde (Bpy-CHO). The one-dimensional covalent organic framework is constructed based on a linear photosensitizer element, serves as a novel one-dimensional covalent organic framework material and a photocatalyst, and has the capacity of generating an acidic H2O2 synthesis system. The method is used for synthesizing the ethylene glycol through light-heat one-pot series connection, and a light-heat series connection catalysis strategy for preparing the ethylene glycol through one-pot ethylene oxide is provided for the first time.

Description

Technical Field

[0001] The present application relates to an organic compound 1,3,6,8-tetra(m-aniline)pyrene, a one-dimensional covalent organic framework, and a preparation method and application thereof, belonging to the field of materials. Background Art

[0002] As an important chemical, ethylene glycol (EG) had a global consumption of 42 million tons in 2023. Industrially, the synthesis of ethylene glycol is divided into two steps. First, ethylene is oxidized to ethylene oxide (EO) using an expensive silver-based catalyst under high temperature and pressure with oxygen, and then hydrolysis is carried out using a strong acid to obtain ethylene glycol. Therefore, developing green and efficient EG synthesis is a crucial research content at present.

[0003] Wang Lei et al. reported a tandem reaction for the electrocatalytic oxidation-reduction preparation of hydrogen peroxide and ethylene oxidation. He not only needed multiple reactors, an additional separation step, and an additional acid to catalyze the hydrolysis of ethylene oxide (DOI: 10.1038 / s41929-023-00977-6). Lu Anhui reported a one-pot tandem reaction: electrocatalytic oxygen reduction and ethylene oxidation. Although he avoided the intermediate separation, an additional acid was needed (DOI: 10.1002 / anie.202302466).

[0004] Compared with oxygen, hydrogen peroxide (H 2 O 2 ) combined with titanium silicalite (TS-1) catalyst can achieve the epoxidation of ethylene under mild conditions, and then hydrolysis in an acidic solution to form EG. As a clean and renewable energy source, using photocatalytic oxygen reduction (ORR) to prepare H 2 O 2 and coupling with TS-1 for ethylene oxidation to prepare EO is a promising method. Nevertheless, an additional acid is necessary for the hydrolysis of EO. Since photocatalytic O 2 reduction and water oxidation (WOR) are one-pot reactions, using the protons (H + ) released by WOR to catalyze the hydrolysis of EO is an effective way to avoid the use of additional acid. Compared with ORR, WOR is usually the rate-determining step for photocatalytic H 2 O 2 synthesis. Therefore, the long-term existence of H + in the reaction system is unlikely. So an acidic H 2 O 2 synthesis system has not been reported yet. Summary of the Invention

[0005] The present application designed and synthesized 1,3,6,8-tetra(m-aniline)pyrene (3-Py-NH 2Building blocks, and then using 3-Py-NH 2 and 2,2'-bipyridine-5,5'-dicarboxaldehyde (Bpy-CHO) to prepare a novel one-dimensional COF (1D COF-Bpy). As a novel one-dimensional covalent organic framework material, as a photocatalyst, it has the ability to generate acidic H 2 O 2 in the synthesis system.

[0006] According to the first aspect of the present application, there is provided an organic compound 1,3,6,8-tetra(m-aminophenyl)pyrene. This compound is different from the existing 1,3,6,8-tetra(p-aminophenyl)pyrene. The p-position is easily obtained, and the m-position has not been reported.

[0007] An organic compound, the organic compound is 1,3,6,8-tetra(m-aminophenyl)pyrene, and the structural formula is as follows:

[0008]

[0009] According to the second aspect of the present application, there is provided a preparation method of an organic compound 1,3,6,8-tetra(m-aminophenyl)pyrene.

[0010] The preparation method of the above-mentioned organic compound, the preparation method includes:

[0011] Reacting a mixture containing 1,3,6,8-tetrabromopyrene, 3-aminophenylboronic acid pinacol ester, a base, a catalyst and a solvent to obtain the organic compound 1,3,6,8-tetra(m-aminophenyl)pyrene.

[0012] Optionally, the molar ratio of 1,3,6,8-tetrabromopyrene to 3-aminophenylboronic acid pinacol ester is 1:5 to 7.

[0013] Optionally, the base is selected from at least one of potassium carbonate, sodium carbonate, cesium carbonate, cesium fluoride, potassium phosphate, barium hydroxide;

[0014] The catalyst is selected from at least one of Pd(PPh 3 ) 4 , AsPh 3 , n-Bu 3 P, (MeO) 3 P, dppe, dppp;

[0015] The solvent is selected from at least one of dioxane, ethanol, toluene, DMF.

[0016] Optionally, the base is potassium carbonate;

[0017] The catalyst is Pd(PPh 3 ) 4 ;

[0018] The solvent is dioxane.

[0019] Optionally, the reaction is carried out under reflux in an inert atmosphere.

[0020] To obtain meta-1,3,6,8-tetra(m-aminophenyl)pyrene, the special feature lies in that the synthesis raw materials are 1,3,6,8-tetrabromopyrene and 3-aminophenylboronic acid pinacol ester. The types and dosages of the base, catalyst, and solvent, as well as the reaction conditions, are selected according to the conventional operation methods in the art.

[0021] According to the third aspect of the present application, a one-dimensional covalent organic framework is provided.

[0022] A one-dimensional covalent organic framework, the structural formula of the one-dimensional covalent organic framework is as follows:

[0023]

[0024] According to the fourth aspect of the present application, a preparation method of a one-dimensional covalent organic framework is provided. The one-dimensional covalent organic framework is constructed based on linear photosensitizer units. By synthesizing 1,3,6,8-tetra(m-aminophenyl)pyrene (3-Py-NH 2 ), building blocks, and then using 3-Py-NH 2 and 2,2'-bipyridine-5,5'-dicarboxaldehyde (Bpy-CHO) to prepare a novel one-dimensional COF (1DCOF-Bpy). When the raw material is 1,3,6,8-tetra(p-aminophenyl)pyrene, a two-dimensional covalent organic framework (2DCOF-Bpy) is obtained.

[0025] The preparation method of the above-mentioned one-dimensional covalent organic framework, the preparation method includes:

[0026] Degas a mixture containing 1,3,6,8-tetra(m-aminophenyl)pyrene, 2,2'-bipyridine-5,5'-dicarboxaldehyde, an acid, and a solvent under a freeze-pump-thaw cycle, heat and react under sealed conditions, separate, wash, and dry to obtain the one-dimensional covalent organic framework.

[0027] Optionally, the molar ratio of 1,3,6,8-tetra(m-aminophenyl)pyrene to 2,2'-bipyridine-5,5'-dicarboxaldehyde is 1:1.5 - 2.5.

[0028] Optionally, the acid is selected from at least one of acetic acid, trifluoroacetic acid, hydrochloric acid, and p-toluenesulfonic acid.

[0029] Optionally, the solvent is dioxane and mesitylene.

[0030] Optionally, the freezing is rapid freezing at a temperature of 77 - 150 K.

[0031] Optionally, repeat 2 to 5 times.

[0032] Optionally, the conditions for the heating reaction are: temperature 90 - 180 °C, time 72 - 120 h.

[0033] Optionally, after uniformly mixing 1,3,6,8 - tetra(m - aminophenyl)pyrene, 2,2'-bipyridine - 5,5'-dicarboxaldehyde, and a solvent, an aqueous acetic acid solution is added to obtain a mixture.

[0034] According to the fifth aspect of the present application, there is provided an application of a one - dimensional covalent organic framework. This one - dimensional covalent organic framework, as a photocatalyst, has the ability to generate an acidic H 2 O 2 synthesis system. It is used for the synthesis of ethylene glycol in a one - pot photo - thermal tandem reaction, which is the first proposed photo - thermal tandem catalytic strategy for the one - pot preparation of ethylene glycol from ethylene oxide. It photocatalytically reduces oxygen to prepare hydrogen peroxide, then couples with a thermal catalyst to in - situ oxidize ethylene to ethylene oxide, and finally uses an acidic system to hydrolyze ethylene oxide to obtain ethylene glycol.

[0035] The above - mentioned application of the one - dimensional covalent organic framework as a photocatalyst.

[0036] Optionally, in the one - pot preparation of ethylene glycol from ethylene oxide, the one - dimensional covalent organic framework serves as a photocatalyst, couples with a thermal catalyst to in - situ oxidize ethylene to ethylene oxide, and then uses an acidic system to hydrolyze ethylene oxide to obtain ethylene glycol.

[0037] The beneficial effects that the present application can produce include:

[0038] The organic compound 1,3,6,8 - tetra(m - aminophenyl)pyrene, the one - dimensional covalent organic framework, and their preparation methods and applications provided by the present application. This one - dimensional covalent organic framework is constructed based on linear photosensitizer units. As a novel one - dimensional covalent organic framework material, as a photocatalyst, it has the ability to generate an acidic H 2 O 2 synthesis system. It is used for the synthesis of ethylene glycol in a one - pot photo - thermal tandem reaction, which is the first proposed photo - thermal tandem catalytic strategy for the one - pot preparation of ethylene glycol from ethylene oxide. It photocatalytically reduces oxygen to prepare hydrogen peroxide, then couples with a thermal catalyst to in - situ oxidize ethylene to ethylene oxide, and finally uses an acidic system to hydrolyze ethylene oxide to obtain ethylene glycol. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 Schematic diagram for the preparation of 1D COF - Bpy in Example 1 of the present invention;

[0040] Figure 2 XRD pattern of 1D COF - Bpy in Example 1 of the present invention;

[0041] Figure 3 Photocurrent diagrams of 1D COF-Bpy prepared in Example 1, 2D COF-Bpy prepared in Comparative Example 1, and 1D COF-Bph prepared in Comparative Example 2;

[0042] Figure 4 Time-resolved fluorescence lifetime diagrams of 1D COF-Bpy prepared in Example 1, 2D COF-Bpy prepared in Comparative Example 1, and 1D COF-Bph prepared in Comparative Example 2;

[0043] Figure 5 Performance diagrams of the tandem photothermal catalytic synthesis of ethylene glycol using 1D COF-Bpy prepared in Example 1, 2D COF-Bpy prepared in Comparative Example 1, and 1D COF-Bph prepared in Comparative Example 2;

[0044] Figure 6 Long-term ethylene glycol synthesis stability diagram of 1D COF-Bpy prepared in Example 1. Detailed implementation manners

[0045] The present application will be described in detail below with reference to the examples, but the present application is not limited to these examples.

[0046] Unless otherwise specified, the raw materials and catalysts in the examples of the present application are all purchased through commercial channels.

[0047] Unless otherwise specified, the test methods are all conventional methods, and the instrument settings are all the settings recommended by the manufacturer.

[0048] The 1,3,6,8-tetrabromopyrene and 3-aminophenylboronic acid pinacol ester used are from Adamas.

[0049] The analysis methods in the examples of the present application are as follows:

[0050] The powder X-ray spectral data is collected using a SmartLab X-ray diffractometer (Rigaku).

[0051] The fluorescence spectrum is measured using an Edinburgh FL / FS1000.

[0052] For the 600 MHz 1 The instrument model of the H-NMR spectrometer is JNM-ECZ600R, JEOL.

[0053] The photocurrent diagram is measured using an instrument model of Zahner (IM6). The analysis and testing process is as follows: 2 mg of the well-ground sample and 2 ml of ethanol (5% Nafion) are mixed under ultrasound for 30 minutes to fully disperse the sample. The obtained slurry is dropped on a piece with a covering area of 1 cm 2onto a fluorine-doped tin oxide (FTO) glass substrate. The uncoated part of the electrode was coated with epoxy resin. It was air-dried naturally. The photocurrent was recorded by an electrochemical workstation (IM6). A platinum mesh electrode and an Ag / AgCl electrode were used as the counter electrode and the working electrode, respectively. The working electrode was immersed in 0.2 M Na 2 SO 4 aqueous solution. The working electrode was irradiated with a xenon lamp.

[0054] Figure 1 For Example 1 of the present invention, the preparation schematic diagram of 1D COF-Bpy. 1,3,6,8-Tetra(m-aminophenyl)pyrene (3-Py-NH 2 ) was used as the building block and reacted with 2,2'-bipyridine-5,5'-dicarbaldehyde (Bpy-CHO) to prepare 1D COF-Bpy.

[0055] Example 1

[0056] Preparation method of 1D COF-Bpy photocatalyst:

[0057] 1. To 1,3,6,8-tetrabromopyrene (500 mg, 0.96 mmol), 3-aminophenylboronic acid pinacol ester (1.27 g, 5.8 mmol), K 2 CO 3 (1.05 g, 7.6 mmol) and dioxane (20 mL), Pd(PPh 3 ) 4 (0.06 g, 0.05 mmol) was added. The resulting mixture was stirred and refluxed for 3 days under N 2 . After cooling to a constant temperature, the solid was filtered off and extracted 3 times with ethyl acetate / H 2 O. The organic phase was evaporated after drying over MgSO 4 to obtain the crude product. The crude product was purified by silica gel column chromatography to obtain 3-Py-NH 2 .

[0058] 2. In a Pyrex tube, 3-Py-NH 2 (0.02 mmol, 11.3 mg), Bpy-CHO (0.04 mmol, 8.5 mg), 250 μL of dioxane and 750 μL of mesitylene were added. The tube was immersed in an ultrasonic bath for 15 minutes; after ultrasonic treatment, 100 mL of 6 M acetic acid aqueous solution was added. The tube was quickly frozen at 77 K and degassed under three cycles of freeze-pump-thaw. The tube was flame-sealed and heated at 120 °C for 3 days. The solid was located at the bottom of the tube, separated by filtration, washed with tetrahydrofuran, and air-dried to obtain 1D COF-Bpy.

[0059] Comparative Example 1

[0060] According to the same method as in Example 1, except that 3-Py-NH 2 was replaced with 1,3,6,8-tetra(p-aniline)pyrene, a pyrene-containing two-dimensional covalent organic framework (denoted as 2D COF-Bpy) was synthesized.

[0061] Comparative Example 2

[0062] According to the same method as in Example 1, except that Bpy-CHO was replaced with 4,4-biphenyldicarboxaldehyde, a biphenyl-containing one-dimensional covalent organic framework (denoted as 1D COF-Bph) was synthesized.

[0063] Characterization and Testing

[0064] Figure 2 This is the XRD pattern of 1D COF-Bpy in Example 1 of the present invention. It can be seen that there is a small difference factor (Rp = 3.3%, Rwp = 4.2%) between the experimentally tested XRD and the theoretical simulation, indicating that 1D COF-Bpy was successfully synthesized.

[0065] Figure 3 This is the photocurrent diagram of 1D COF-Bpy prepared in Example 1, 2D COF-Bpy prepared in Comparative Example 1, and 1D COF-Bph prepared in Comparative Example 2. It can be seen that compared with 2D COF-Bpy and 1D COF-Bph, 1D COF-Bpy has the highest photocurrent intensity, indicating that 1D COF-Bpy is more conducive to the separation of photo-generated carriers and the improvement of photocatalytic reaction performance.

[0066] Figure 4 This is the time-resolved fluorescence lifetime diagram of 1D COF-Bpy prepared in Example 1, 2D COF-Bpy prepared in Comparative Example 1, and 1D COF-Bph prepared in Comparative Example 2. It can be seen that 1D COF-Bpy has the longest fluorescence lifetime, indicating that it is not easily de-excited, which will be conducive to the progress of the photocatalytic reaction.

[0067] Application Example

[0068] Disperse 1D COF-Bpy (5 mg) in 10 mL of aqueous solution in a quartz reactor and sonicate for 30 minutes. Then add 300 mg of TS-1 to the above system. Degas the quartz reactor with a vacuum pump and then backfill with oxygen and ethylene. This process is repeated three times. After the last cycle, backfill the flask with oxygen and ethylene (1.0 atm). Keep the reaction solution at 25 °C, stir for 30 minutes, and irradiate under a Xe lamp with a λ≥400 nm cut-off filter. After the photocatalytic reaction is completed, the suspension is filtered through a 0.45 μm nylon 66 filter to remove the photocatalyst particles. With D 2O and DMSO were used as the locking solvent and internal standard respectively. 600 μL of the solution after photocatalysis was mixed with 80 μL of D 2 O and 0.08 μL of dimethyl sulfoxide (DMSO) as the internal standard, and the concentration of ethylene glycol (EG) was measured on a 600 MHz 1 1H NMR.

[0069] According to the above steps, 1D COF-Bpy was replaced with 2D COF-Bpy prepared in Comparative Example 1 and 1D COF-Bph prepared in Comparative Example 2 respectively, and their performance in photocatalytic tandem synthesis of ethylene glycol was tested. As Figure 5 shown, it can be seen that due to the efficient separation of photo-generated carriers and the long-lived excited state, 1D COF-Bpy has a higher EG yield.

[0070] The long-term ethylene glycol synthesis stability of 1D COF-Bpy prepared in Example 1 was tested. As Figure 6 shown, it can be seen that due to the high chemical stability, 1D COF-Bpy can achieve continuous production of EG for 96 hours.

[0071] The above are only several embodiments of the present application, and do not impose any form of limitation on the present application. Although the present application is disclosed as above with preferred embodiments, it is not intended to limit the present application. Any person skilled in the art, without departing from the scope of the technical solution of the present application, makes some changes or modifications using the technical content disclosed above, which are equivalent to equivalent implementation cases and all fall within the scope of the technical solution.

Claims

1. An organic compound, characterized in that The organic compound is 1,3,6,8-tetrakis(m-aniline)pyrene, and the structural formula is as follows:

2. The method for preparing an organic compound according to claim 1, characterized in that: The preparation method comprises: A mixture containing 1,3,6,8-tetrabromopyrene, 3-aminophenylboronic acid pinacol ester, a base, a catalyst and a solvent is reacted to obtain the organic compound 1,3,6,8-tetrakis(m-anilino)pyrene.

3. The preparation method according to claim 2, characterized in that: The molar ratio of 1,3,6,8-tetrabromopyrene and 3-aminophenylboronic acid pinacol ester is 1:5-7; Preferably, the base is selected from at least one of potassium carbonate, sodium carbonate, cesium carbonate, cesium fluoride, potassium phosphate, and barium hydroxide; The catalyst is selected from at least one of Pd(PPh3)4, AsPh3, n-Bu3P, (MeO)3P, dppe, and dppp; The solvent is selected from at least one of dioxane, ethanol, toluene and DMF; Preferably, the reaction is carried out under reflux in an inert atmosphere.

4. A one-dimensional covalent organic framework, characterized in that The structural formula of the one-dimensional covalent organic framework is as follows:

5. The method for preparing the one-dimensional covalent organic framework according to claim 4, characterized in that: The preparation method comprises: Degassing a mixture containing 1,3,6,8-tetrakis(m-aniline)pyrene, 2,2'-bipyridine-5,5'-dicarboxaldehyde, an acid, and a solvent under a freeze-evacuate-thaw cycle, heating for reaction under sealed conditions, separating, washing, and drying to obtain the one-dimensional covalent organic framework; The 1,3,6,8-tetrakis(m-anilino)pyrene is the organic compound according to claim 1.

6. The preparation method according to claim 5, characterized in that: The molar ratio of 1,3,6,8-tetrakis(m-aniline)pyrene to 2,2'-bipyridine-5,5'-dicarboxaldehyde is 1:1.5-2.5; Preferably, the acid is selected from at least one of acetic acid, trifluoroacetic acid, hydrochloric acid and p-toluenesulfonic acid; The solvents are dioxane and mesitylene.

7. The preparation method according to claim 5, characterized in that: The freezing is quick freezing at a temperature of 77 to 150 K; Preferably, the cycle is 2 to 5 times; Preferably, the heating reaction conditions are: temperature of 90 to 180° C. and time of 72 to 120 h.

8. The preparation method according to claim 5, characterized in that: After 1,3,6,8-tetrakis(m-aniline)pyrene, 2,2'-bipyridine-5,5'-dicarbaldehyde and a solvent are uniformly mixed, an acetic acid aqueous solution is added to obtain a mixture.

9. Use of the one-dimensional covalent organic framework according to claim 4 as a photocatalyst.

10. The use according to claim 9, characterized in that: In the one-pot oxidation of ethylene to ethylene glycol, a one-dimensional covalent organic framework acts as a photocatalyst, coupled with a thermal catalyst to in situ oxidize ethylene to ethylene oxide, and then an acidic system is used to hydrolyze ethylene oxide to obtain ethylene glycol.

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