Porous organic molecular framework material as well as preparation method and application thereof

Abstract

The invention discloses a porous organic molecular framework material POM-FPDT constructed by non-covalent pi accumulation as well as a preparation method and application of the porous organic molecular framework material POM-FPDT. The porous organic molecular framework material POM-FPDT constructed by non-covalent pi accumulation provided by the invention has an elliptical permanent one-dimensional through pore channel, has good thermal stability, recyclability and high selectivity, and can effectively realize efficient separation of ethanol / water and acetonitrile / water.

Description

Technical Field

[0001] This application relates to a porous organic molecular framework material, its preparation method, and its application, belonging to the field of fine chemical separation technology. Background Technology

[0002] Acetonitrile and ethanol, as common low-boiling-point organic solvents, play a crucial role in modern chemistry and related industries. From a chemical synthesis perspective, acetonitrile and ethanol, with their excellent solubility and unique chemical properties, can dissolve numerous organic, inorganic, and gaseous substances, providing ideal media for various complex organic synthesis reactions. However, the readily available acetonitrile and ethanol form azeotropes with water, making their acquisition difficult. Traditional separation methods (distillation, rectification, extraction) for azeotropes suffer from excessive energy consumption, complex operations, and environmental pollution. While traditional inorganic molecular sieves offer good separation capabilities for water, acetonitrile, and ethanol, the strong interaction between water molecules and inorganic molecular sieves results in high regeneration temperatures (approximately 250°C), leading to significant energy waste during regeneration. As an alternative, adsorption-based separation methods are considered energy-efficient and environmentally friendly due to their high selectivity and ease of regeneration.

[0003] Crystalline porous organic molecular framework materials are a new type of porous material formed by the self-assembly of organic ligands through CH···π, π···π interactions and van der Waals forces. Due to their advantages such as high specific surface area, porosity, strong designability, mild synthesis conditions, and recyclability, they are widely used in gas adsorption and separation, molecular recognition, proton conduction, and biomedicine. Summary of the Invention

[0004] In view of the above, the purpose of this application is to provide a non-covalent π-stacking porous organic molecular framework material POM-FPDT, its preparation method and application, so as to achieve adsorption separation of acetonitrile / water and ethanol / water.

[0005] The first aspect of this application provides a non-covalently π-stacked porous organic molecular framework material POM-FPDT, wherein the organic ligand in POM-FPDT includes a 3-fluoropyridine-triazine derivative FPDT, and the FPDT has the structure shown in Formula I: Formula I The POM-FPDT contains an elliptical permanent one-dimensional through-hole.

[0006] In this application, the "permanent" one-dimensional channels of the porous organic molecular framework material refer to irreversible pore structures that remain stable even after the removal of guest molecules.

[0007] Optionally, the chemical structural formula of the POM-FPDT is (C 47 H 30 FN7) n , where n represents the number of structural units. Optionally, the POM-FPDT is constructed using FPDT with a linear molecular structure as the building block, and is linked by multiple CH···F hydrogen bonds and CH···π interactions; Preferably, the structural unit of the POM-FPDT is a monoclinic crystal system; Preferably, the porosity of the POM-FPDT is 10% to 12%; Preferably, the specific surface area of ​​the POM-FPDT is 300–350 m². 2 ·g -1 .

[0008] Preferably, the size of the one-dimensional channel is p×m, where p is 5.07~5.67 Å and m is 11.49~12.09 Å.

[0009] The second aspect of this application provides a method for preparing the non-covalent π-stacking porous organic molecular framework material POM-FPDT described in the first aspect of this application, comprising the following steps: 1) 2,5-Dibromo-3-fluoropyridine, 2,4-diphenyl-6-(4-(4,4,5,5)-tetramethyl-1,3,2-dioxacyclopentaborane-2-yl)phenyl)-1,3,5-triazine, a first organic solvent, and a catalyst are mixed and reacted to obtain the 3-fluoropyridine-triazine derivative FPDT; wherein the catalyst contains at least one first component selected from rubidium carbonate, cesium carbonate, potassium carbonate, and sodium carbonate, and a second component selected from tetrakis(triphenylphosphine)palladium(II); preferably, the catalyst contains potassium carbonate and tetrakis(triphenylphosphine)palladium(II); 2) The 3-fluoropyridine-triazine derivative FPDT is dissolved in a second organic solvent and crystallized to obtain the non-covalent π-stacking porous organic molecular framework material POM-FPDT.

[0010] Preferably, the molar ratio of the 2,5-dibromo-3-fluoropyridine to the 2,4-diphenyl-6-(4-(4,4,5,5)-tetramethyl-1,3,2-dioxacyclopentaborane-2-yl)phenyl)-1,3,5-triazine is 1:(2-3).

[0011] In some embodiments of this application, the first organic solvent may be any solvent capable of dissolving both 2,5-dibromo-3-fluoropyridine and 2,4-diphenyl-6-(4-(4,4,5,5)-tetramethyl-1,3,2-dioxacyclopentaborane-2-yl)phenyl)-1,3,5-triazine. Those skilled in the art can select a suitable organic solvent based on the solubility of the two reactants; this application does not impose any limitations on this selection. Optionally, the first organic solvent may be selected from 1,4-dioxane or a mixed solvent containing 1,4-dioxane, toluene, and water; preferably, the volume ratio of 1,4-dioxane, toluene, and water is (2-3):(1-1.5):1. Preferably, in the catalyst, the molar ratio of the first component to the second component is (20-40):1; Preferably, the molar ratio of 2,5-dibromo-3-fluoropyridine to tetrakis(triphenylphosphine)palladium(II) is (5-10):1; Preferably, the mass-to-volume ratio of 2,5-dibromo-3-fluoropyridine to the first organic solvent is 1 g: (100-150) ml; Preferably, step 1) further includes a vacuum degassing step before the reaction; preferably, the vacuum degassing includes a vacuum degassing step of the 2,5-dibromo-3-fluoropyridine, 2,4-diphenyl-6-(4-(4,4,5,5)-tetramethyl-1,3,2-dioxacyclopentaborane-2-yl)phenyl)-1,3,5-triazine and the first organic solvent; preferably, the vacuum degassing step occurs before the 2,5-dibromo-3-fluoropyridine, 2,4-diphenyl-6-(4-(4,4,5,5)-tetramethyl-1,3,2-dioxacyclopentaborane-2-yl)phenyl)-1,3,5-triazine are mixed with the first solvent. It should be noted that, in some embodiments of this application, the step of mixing 2,5-dibromo-3-fluoropyridine, 2,4-diphenyl-6-(4-(4,4,5,5)-tetramethyl-1,3,2-dioxacyclopentaborane-2-yl)phenyl)-1,3,5-triazine, the first organic solvent, and the catalyst can be achieved by first mixing the two reaction substrates, 2,5-dibromo-3-fluoropyridine and 2,4-diphenyl-6-(4-(4,4,5,5)-tetramethyl-1,3,2-dioxacyclopentaborane-2-yl)phenyl)-1,3,5-triazine, the first organic solvent, and the catalyst. The reaction mixture is made of alkyl-2-yl)phenyl)-1,3,5-triazine and then mixed with a first organic solvent and a catalyst; alternatively, the two reaction substrates can be dissolved separately in an organic solvent to achieve the mixing of the three. In some embodiments of this application, the vacuum degassing step occurs before the two reaction substrates are mixed with the first organic solvent. That is, the two substrates and the organic solvent can be vacuum degassed separately and then the three can be mixed. Alternatively, the two reaction substrates can be mixed first, then vacuum degassed, and then mixed with the vacuum degassed first organic solvent.

[0012] Preferably, in step 1), the reaction is carried out in an inactive atmosphere, and preferably, the gas in the inactive atmosphere includes at least one of nitrogen, helium, and argon. Preferably, in step 1), the reaction temperature is 80-150°C; more preferably, it is 110-130°C. Preferably, in step 1), the reaction time is 18-30 hours; Preferably, in step 1), the reaction further includes a step of cooling to room temperature; Preferably, in step 1), the reaction further includes steps of solvent removal, washing, and purification; In this application, solvent removal, washing, and purification can be carried out using conventional techniques in the field, as long as they can achieve the purpose of this application. This application does not limit these techniques. For example, solvent removal can be carried out by rotary evaporation; washing can be carried out by ethanol and distilled water; purification can be carried out by recrystallization purification, etc.

[0013] Preferably, the solvent used for recrystallization purification can be a second organic solvent. For example, when N,N-dimethylformamide is used as the second organic solvent, N,N-dimethylformamide is also selected as the solvent for recrystallization purification.

[0014] Optionally, the second solvent is used to dissolve the 3-fluoropyridine-triazine derivative FPDT. Those skilled in the art can select a suitable second solvent according to the actual situation. Preferably, in step 2), the second organic solvent is selected from N-dimethylformamide or a mixed solvent containing N,N-dimethylformamide and tetrahydrofuran; preferably, in the mixed solvent, the volume ratio of N,N-dimethylformamide and tetrahydrofuran is 1:(0.8-1.2).

[0015] In some embodiments of this application, crystallization after dissolution in step 2) is a conventional operation in the art, and those skilled in the art are capable of obtaining suitable crystallization conditions, such as cooling crystallization, which will not be described in detail here.

[0016] The third aspect of this application provides the application of the non-covalent π-stacking porous organic molecular framework material POM-FPDT of the first aspect of this application in the separation of acetonitrile / water mixtures. The fourth aspect of this application provides the application of the non-covalent π-stacking porous organic molecular framework material POM-FPDT of the first aspect of this application in the separation of ethanol / water mixtures. The fifth aspect of this application provides the application of POM-FPDT, a porous organic molecular framework material constructed by non-covalent π stacking as described in the first aspect of this application, as a packing material for gas chromatography separation columns.

[0017] In some embodiments, the gas chromatography column can be used to separate acetonitrile / water mixtures.

[0018] In some embodiments, the gas chromatography column can be used to separate ethanol / water mixtures.

[0019] The sixth aspect of this application provides a 3-fluoropyridine-triazine derivative FPDT having the structure shown in Formula I: Formula I.

[0020] The seventh aspect of this application provides a method for preparing the 3-fluoropyridine-triazine derivative FPDT provided in the fifth aspect of this application, comprising the following steps: S1) 2,5-Dibromo-3-fluoropyridine, 2,4-diphenyl-6-(4-(4,4,5,5)-tetramethyl-1,3,2-dioxacyclopentaborane-2-yl)phenyl)-1,3,5-triazine, a first organic solvent, and a catalyst are mixed and reacted to obtain the 3-fluoropyridine-triazine derivative FPDT; wherein the catalyst contains at least one first component selected from rubidium carbonate, cesium carbonate, potassium carbonate, and sodium carbonate, and a second component selected from tetrakis(triphenylphosphine)palladium(II); preferably, the catalyst contains potassium carbonate and tetrakis(triphenylphosphine)palladium(II); S2) Remove the organic solvent from the reaction product obtained in step S1) to obtain the crude FPDT product.

[0021] Preferably, the molar ratio of the 2,5-dibromo-3-fluoropyridine to the 2,4-diphenyl-6-(4-(4,4,5,5)-tetramethyl-1,3,2-dioxacyclopentaborane-2-yl)phenyl)-1,3,5-triazine is 1:(2-3); Preferably, the first organic solvent is selected from 1,4-dioxane or a mixed solvent containing 1,4-dioxane, toluene and water; preferably, the volume ratio of 1,4-dioxane, toluene and water is (2-3):(1-1.5):1. Preferably, in the catalyst, the molar ratio of the first component to the second component is (20-40):1; Preferably, the molar ratio of 2,5-dibromo-3-fluoropyridine to tetrakis(triphenylphosphine)palladium(II) is (5-10):1; Preferably, the mass-to-volume ratio of 2,5-dibromo-3-fluoropyridine to the first organic solvent is 1 g: (100-150) ml; Preferably, step S1) further includes a vacuum degassing step before the reaction; preferably, the vacuum degassing includes a vacuum degassing step of the 2,5-dibromo-3-fluoropyridine, 2,4-diphenyl-6-(4-(4,4,5,5)-tetramethyl-1,3,2-dioxacyclopentaborane-2-yl)phenyl)-1,3,5-triazine and the first organic solvent; preferably, the vacuum degassing step occurs before the 2,5-dibromo-3-fluoropyridine, 2,4-diphenyl-6-(4-(4,4,5,5)-tetramethyl-1,3,2-dioxacyclopentaborane-2-yl)phenyl)-1,3,5-triazine are mixed with the first solvent.

[0022] Preferably, in step S1), the reaction is carried out in an inactive atmosphere; preferably, the gas in the inactive atmosphere includes at least one of nitrogen, helium, and argon.

[0023] Preferably, in step S1), the reaction temperature is 80-150°C; more preferably, it is 110-130°C. Preferably, in step S1), the reaction time is 18-30 hours; Preferably, in step S1), the reaction further includes a step of cooling to room temperature; In some embodiments, the preparation method of the 3-fluoropyridine-triazine derivative FPDT further includes step S3), washing and purifying the crude FPDT; preferably, the purification is recrystallization purification.

[0024] This application provides an eighth aspect of the application of the 3-fluoropyridine-triazine derivative FPDT provided in the sixth aspect of this application in the preparation of porous organic molecular framework materials with non-covalent π-stacking structures. The 3-fluoropyridine-triazine derivative FPDT serves as a building block, linked by multiple CH···F hydrogen bonds and CH···π interactions to form a porous organic molecular framework material POM-FPDT with elliptical permanent one-dimensional through-pores.

[0025] The beneficial effects that this application can produce include: 1) The POM-FPDT material of this application has a large specific surface area and porosity, good stability, and the interior of the elliptical one-dimensional channels can interact with acetonitrile and ethanol to form CH···O, CH···N, CH···F, etc., thereby realizing the separation of acetonitrile / water mixtures and ethanol / water mixtures; the selective adsorption separation technology based on the novel porous material can effectively improve the separation efficiency, reduce industrial energy consumption, and promote the development of green separation technology.

[0026] 2) The organic ligand is dissolved in N,N-dimethylformamide and rapidly cooled to obtain white microcrystals (POM-FPDT). The preparation is simple and the synthesis conditions are mild.

[0027] 3) This application uses a gas chromatography column filled with POM-FPDT material to achieve the separation of acetonitrile / water and ethanol / water under different temperatures, ratios and other conditions; and the material can be recycled. Attached Figure Description

[0028] Figure 1 Example 1 describes the preparation of linear molecular FPDT. 1 H-NMR spectrum; Figure 2 This is a schematic diagram of the three-dimensional structure of the organic molecular framework material POM-FPDT prepared in Example 2, which has an elliptical permanent one-dimensional through-pore. Figure 3 The CO2 adsorption curve of the organic molecular framework material synthesized in Preparation Example 2 is shown at 195 K. Figure 4 This is the GC separation curve of the acetonitrile / water mixture in Example 1; Figure 5 The GC separation curve is the cyclic performance of the acetonitrile / water mixture in Example 1; Figure 6 This is the GC separation curve of the ethanol / water mixture in Example 1; Figure 7 This is the GC separation curve of the ethanol / water mixture cycle performance in Example 1. Detailed Implementation

[0029] The present application is described in detail below with reference to the embodiments, but the present application is not limited to these embodiments.

[0030] Unless otherwise specified, the raw materials and catalysts used in the embodiments of this application were all purchased commercially.

[0031] The structural data of the crystal were collected using XtaLAB Synergy R, HyPix diffractometer with Cu Kα diffractometer. The proton nuclear magnetic resonance (NMR) spectrometry was performed using a Bruker AV-400 spectrometer (400 MHz). Carbon dioxide adsorption at 195 K was tested using the Micromeritics 3FLEX surface area analyzer, and the data were used for BET analysis. Column penetration separation analysis was performed using the Agilent 7890B GC system. In the embodiments of this application, the yield is calculated as follows: the yield calculation formula is (actual yield / theoretical yield) × 100%.

[0032] Preparation Example 1: Preparation of 3-fluoropyridine-triazine derivative monomer FPDT

[0033] 2,5-Dibromo-3-fluoropyridine (CAS No.: 156772-60-0, 2.0 g, 7.85 mmol), 2,4-diphenyl-6-(4-(4,4,5,5)-tetramethyl-1,3,2-dioxane-2-yl)phenyl)-1,3,5-triazine (CAS No.: 1219956-23-6, 6.8 g, 15.69 mmol), potassium carbonate (6.5 g, 47.08 mmol), and tetra(triphenylphosphine)palladium(II) (1.8 g, 1.569 mmol) were added to a Schleeck flask (500 mL) equipped with a magnetic stirrer. The mixture was degassed under vacuum for 30 minutes, and nitrogen was pumped in under vacuum. This process was repeated three times. Then, 250 mL of the degassed mixed solvent of 1,4-dioxane, toluene, and water (volume ratio 2:1:1) was transferred to the flask. The solution was heated at 120 °C for 24 hours under a nitrogen atmosphere. After the reaction was complete, the mixture was cooled to room temperature, and the organic solvent was removed by rotary evaporation. The crude product was washed with ethanol (3 × 100 mL) and distilled water (3 × 200 mL), and then purified by recrystallization with N,N-dimethylformamide to give 5.0 g (7.85 mmol) of a yellowish-white solid, which is the 3-fluoropyridine-triazine derivative monomer FPDT, with a yield of 90%. 1 See H-NMR spectrum Figure 1 .

[0034] Preparation Example 2: Preparation of Porous Organic Molecular Framework Material POM-FPDT 1 g of the organic ligand FPDT obtained in Example 1 was dissolved in N,N-dimethylformamide (DMF, 200-300 mL) by heating. After cooling to room temperature, a large amount of crystals rapidly precipitated. The crystals were filtered, washed with ethanol, and observed as strip-shaped white crystals under an optical microscope. This is the prepared non-covalent π-stacking porous organic molecular framework material POM-FPDT. Its structure was determined by single-crystal diffraction, and the results showed that its structural formula is (C... 47 H 30 FN7) n It belongs to the monoclinic crystal system and has the space group [missing information]. P2 1 / c The unit cell parameters are a =10.7803(4) Å, b =3.7965(2) Å,c =45.510(2) Å, α = γ =90°, β =96.162°, cell volume is 1851.86(15) Å 3 Z=4, Dc=1.361 g / cm³ 3 Each monomer molecule is connected to two adjacent molecules through multiple CH···π, CH···N, and CH···F interactions, self-assembling to form a two-dimensional supramolecular layer. These layers further stack through strong π··π interactions to form a two-dimensional organic framework. This hydrogen-bonded organic framework possesses elliptical one-dimensional channels along the a-axis, with a channel size of approximately 11.79 Å × 5.37 Å. After activation, the material exhibits permanent one-dimensional channels, achieving a porosity of 11.2%. Figure 2 At 195 K and 1 bar, the saturated adsorption capacity of CO2 reached 95.47 cm⁻¹. 3 ·g -1 ( Figure 3 The specific surface area of ​​BET is as high as 322.44 m². 2 ·g -1 .

[0035] Example 1: Separation performance test of acetonitrile / water and ethanol / water Material activation: In order to remove solvent molecules in the material channels and obtain activated crystal material, POM-FPDT is exchanged with ethanol for 4-7 days, and then activated under vacuum and 100-120℃ for 10-24 hours to finally obtain activated crystal material that can be used for acetonitrile / water and ethanol / water separation.

[0036] Gas chromatography column breakthrough separation experiment: Activated POM-FPDT material (0.8 g) was first packed into a stainless steel column (5 mm (inner diameter) × 180 mm (length)), and the column ends were sealed with a sufficient amount of quartz wool. The column was then activated with He gas at 100-120℃ for 8-12 hours. During testing, acetonitrile / water or ethanol / water mixtures were vaporized at 100-150℃ and flowed through the column at a flow rate of 20 mL / min under He purging, detected by a gas chromatograph. GC separation curves showed that the POM-FPDT packed column could effectively separate acetonitrile / water and ethanol / water binary mixtures. Acetonitrile / water mixtures (1 / 1, V / V) could achieve effective baseline separation under optimized conditions. When the column temperature reached 100℃, the retention time of water was 1.36 minutes, and the retention time of acetonitrile was 18.12 minutes. Figure 4Ethanol / water mixtures (1 / 1, V / V) also achieved baseline separation at 100 °C, with retention times of 1.36 and 10.64 minutes for water and ethanol, respectively. Figure 6 The material underwent three adsorption-separation-regeneration cycles, and the GC separation curve of the acetonitrile / water mixture is shown below. Figure 5 As shown, the GC separation curve of the ethanol / water mixture is as follows: Figure 7 As shown, the results indicate that the column exhibits excellent cyclic stability. Longer-term repeated experiments revealed good separation stability of the packed column; after six weeks, no significant change in separation time was observed. These experiments demonstrate that the POM-FPDT packed column can be used for the gas chromatographic separation of acetonitrile / water mixtures and ethanol / water mixtures.

[0037] Comparative Example 1 When ethanol and water were separated using HBCbpeCl as the gas chromatography stationary phase, ethanol eluted at approximately 0.20 min, while water eluted at approximately 9.12 min. (Zhang, Y.-J.; Chen, C.; Cai, L.-X.; Tan, B.; Yang, X.-D.; Zhang, J.; Ji, M., Post-cycloaddition modification of a porous MOF for improved GC separation of ethanol and water.) Dalton Trans 2017, 46, 7092-7097).

[0038] Comparative Example 2 Among them, [Co2(btta)(bib)] n When 2nH2O was used as the stationary phase in gas chromatography to separate ethanol and water, ethanol eluted at approximately 3.34 minutes, while water eluted at approximately 59.30 minutes, indicating that the elution time for water was too long. (Di, Z.; Pang, J.; Hu, F.; Wu, M.; Hong, M., An ultra-stable microporous supramolecular framework with highly selective adsorption and separation of water overethanol.) Nano. Res. 2021, 14, 2584-2588). The above description is merely a few embodiments of this application and is not intended to limit this application in any way. Although this application discloses preferred embodiments as described above, it is not intended to limit this application. Any changes or modifications made by those skilled in the art without departing from the scope of the technical solution of this application using the disclosed technical content are equivalent to equivalent implementation cases and fall within the scope of the technical solution.

Claims

1. A porous organic molecular framework material POM-FPDT constructed with non-covalent π-stacking, characterized in that, The organic ligand in the POM-FPDT includes the 3-fluoropyridine-triazine derivative FPDT, which has the structure shown in Formula I: Equation I The POM-FPDT contains an elliptical permanent one-dimensional through-hole.

2. The porous organic molecular framework material POM-FPDT constructed with non-covalent π-stacking as described in claim 1, characterized in that, The chemical structural formula of the POM-FPDT is (C 46 H 30 FN7) n wherein n represents the number of structural units; Preferably, the POM-FPDT is constructed using the FPDT as the building block, and is linked by multiple CH···F hydrogen bonds and CH···π interactions; Preferably, the structural unit of the POM-FPDT is a monoclinic crystal system; Preferably, the size of the one-dimensional channel is p×m, where p is 5.07~5.67 Å and m is 11.49~12.09 Å; Preferably, the porosity of the POM-FPDT is 10%~12%; Preferably, the specific surface area of ​​the POM-FPDT is 300–350 m². 2 ·g -1 .

3. The method for preparing the non-covalent π-stacking porous organic molecular framework material POM-FPDT as described in claim 1 or 2, characterized in that, Includes the following steps: 1) 2,5-Dibromo-3-fluoropyridine, 2,4-diphenyl-6-(4-(4,4,5,5)-tetramethyl-1,3,2-dioxacyclopentaborane-2-yl)phenyl)-1,3,5-triazine, a first organic solvent, and a catalyst are mixed and reacted to obtain the 3-fluoropyridine-triazine derivative FPDT; wherein, the catalyst contains at least one first component selected from rubidium carbonate, cesium carbonate, potassium carbonate, and sodium carbonate, and a second component selected from tetrakis(triphenylphosphine)palladium(II); preferably, the catalyst contains potassium carbonate and tetrakis(triphenylphosphine)palladium(II); 2) Dissolve the 3-fluoropyridine-triazine derivative FPDT in a second organic solvent and crystallize to obtain the non-covalent π-stacking porous organic molecular framework material POM-FPDT.

4. The method according to claim 3, characterized in that, The molar ratio of the 2,5-dibromo-3-fluoropyridine to the 2,4-diphenyl-6-(4-(4,4,5,5)-tetramethyl-1,3,2-dioxacyclopentaborane-2-yl)phenyl)-1,3,5-triazine is 1:(2-3). Preferably, the first organic solvent is selected from 1,4-dioxane or a mixed solvent containing 1,4-dioxane, toluene and water; preferably, the volume ratio of 1,4-dioxane, toluene and water is (2-3):(1-1.5):

1. Preferably, in the catalyst, the molar ratio of the first component to the second component is (20-40):1; Preferably, the molar ratio of 2,5-dibromo-3-fluoropyridine to tetrakis(triphenylphosphine)palladium(II) is (5-10):1; Preferably, the mass-to-volume ratio of 2,5-dibromo-3-fluoropyridine to the first organic solvent is 1 g: (100-150) ml; Preferably, step 1) further includes a vacuum degassing step before the reaction; Preferably, in step 1), the reaction is carried out in an inactive atmosphere, and preferably, the gas in the inactive atmosphere includes at least one of nitrogen, helium, and argon. Preferably, in step 1), the reaction temperature is 80-150°C; more preferably, it is 110-130°C. Preferably, in step 1), the reaction time is 18-30 hours; Preferably, in step 1), the reaction further includes a step of cooling to room temperature; Preferably, in step 1), the reaction further includes steps of solvent removal, washing, and purification; Preferably, in step 2), the second organic solvent is selected from N,N-dimethylformamide or a mixed solvent containing N,N-dimethylformamide and tetrahydrofuran; preferably, in the mixed solvent, the volume ratio of N,N-dimethylformamide and tetrahydrofuran is 1:(0.8-1.2).

5. The application of the non-covalent π-stacking porous organic molecular framework material POM-FPDT as described in claim 1 or 2 in the separation of acetonitrile / water mixtures.

6. The application of the non-covalent π-stacking porous organic molecular framework material POM-FPDT as described in claim 1 or 2 in the separation of ethanol / water mixtures.

7. The application of the non-covalent π-stacking porous organic molecular framework material POM-FPDT as described in claim 1 or 2 as a packing material for gas chromatography separation columns.

8. A 3-fluoropyridine-triazine derivative FPDT, characterized in that, It has the structure shown in Equation I: Equation I.

9. The method for preparing the 3-fluoropyridine-triazine derivative FPDT according to claim 8, characterized in that, Includes the following steps: S1) 2,5-Dibromo-3-fluoropyridine, 2,4-diphenyl-6-(4-(4,4,5,5)-tetramethyl-1,3,2-dioxacyclopentaborane-2-yl)phenyl)-1,3,5-triazine, a first organic solvent, and a catalyst are mixed and reacted to obtain the 3-fluoropyridine-triazine derivative FPDT; wherein the catalyst contains at least one first component selected from rubidium carbonate, cesium carbonate, potassium carbonate, and sodium carbonate, and a second component selected from tetrakis(triphenylphosphine)palladium(II); preferably, the catalyst contains potassium carbonate and tetrakis(triphenylphosphine)palladium(II); S2) Remove the organic solvent from the reaction product obtained in step S1) to obtain the crude FPDT product; Preferably, the molar ratio of the 2,5-dibromo-3-fluoropyridine to the 2,4-diphenyl-6-(4-(4,4,5,5)-tetramethyl-1,3,2-dioxacyclopentaborane-2-yl)phenyl)-1,3,5-triazine is 1:(2-3); Preferably, the first organic solvent is selected from 1,4-dioxane or a mixed solvent containing 1,4-dioxane, toluene and water; preferably, the volume ratio of 1,4-dioxane, toluene and water is (2-3):(1-1.5):

1. Preferably, in the catalyst, the molar ratio of the first component to the second component is (20-40):1; Preferably, the molar ratio of 2,5-dibromo-3-fluoropyridine to tetrakis(triphenylphosphine)palladium(II) is (5-10):1; Preferably, the mass-to-volume ratio of 2,5-dibromo-3-fluoropyridine to the first organic solvent is 1 g: (100-150) ml; Preferably, in step S1), a vacuum degassing step is included before the reaction; Preferably, in step S1), the reaction is carried out in an inactive atmosphere, and preferably, the gas in the inactive atmosphere includes at least one of nitrogen, helium, and argon. Preferably, in step S1), the reaction temperature is 80-150°C; more preferably, it is 110-130°C. Preferably, in step S1), the reaction time is 18-30 hours; Preferably, in step S1), the reaction further includes a step of cooling to room temperature; Preferably, the method further includes step S3), washing and purifying the crude FPDT to obtain a purified FPDT product; preferably, the purification is recrystallization purification.

10. The application of the 3-fluoropyridine-triazine derivative FPDT according to claim 8 in the preparation of non-covalent π-stacking porous organic molecular framework material POM-FPDT.

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