Solution-processable two-dimensional halogen-bonded organic frameworks, methods of making and use thereof

Abstract

The application discloses a solution-processable two-dimensional halogen-bonded organic framework and a preparation method and application thereof, and belongs to the technical field of organic polymer compounds. The method has the advantages of high synthesis efficiency and reduced production cost. By introducing long-chain alkyl side chains and optimizing solvent selection, the solubility of the two-dimensional halogen-bonded organic framework is significantly enhanced, so that the two-dimensional halogen-bonded organic framework can maintain good dispersibility in various solvents. By means of a cross-linking strategy and functional group introduction, the structural stability of the XOFs in a solution environment is improved, and the long-term reliability and performance consistency of the material are improved. In combination with the introduction of specific functional groups in the framework, the two-dimensional halogen-bonded organic framework is endowed with multiple functions. The two-dimensional halogen-bonded organic framework prepared has high solubility, strong structural stability and multifunctional characteristics, and has a wide prospect in the fields of electronics and sensors.

Description

Technical Field

[0001] The present invention relates to the technical field of organic polymer compounds, and in particular to a solution-processable two-dimensional halogen bond organic framework, a preparation method thereof, and applications thereof. Background Art

[0002] Organic framework materials, an emerging class of functional materials primarily composed of metal organic frameworks (MOFs) and covalent organic frameworks (COFs), have attracted widespread attention due to their exceptional properties. These materials exhibit high crystallinity, extensive surface area, and multifunctionality, making them promising for applications in a variety of fields, including energy storage, separations, electronics, and medical applications. However, the application of these framework materials is limited by their solubility, particularly in solution processing techniques, which significantly impacts their processability.

[0003] Although MOFs and COFs have shown some solution processing capabilities to some extent through methods such as stripping or introducing charges, organic frameworks based on non-covalent bonds, such as hydrogen-bonded organic frameworks (HOFs) and supramolecular organic frameworks (SOFs), generally exhibit better solubility. Among them, HOFs can be easily recrystallized from solution. However, there are relatively few studies on their periodic structures in solution. Therefore, developing a reliable strategy to construct soluble organic frameworks with stable periodic structures is crucial to promoting their applications requiring solution processing technology.

[0004] Recently, halogen-bonded organic frameworks (XOFs) have attracted extensive attention as an emerging supramolecular framework material. + XOFs constructed with halogen bonds have been successfully developed to exhibit specific functions, such as fatty acid vapor adsorption, halogenation reaction, and catalysis. The presence of halogen cations (halogen I) in the framework of this type of material makes it a unique cationic organic framework that exhibits slight solubility in polar solvents. These [NX + The excellent directionality and stability of the [-N] halogen bond enable XOFs to maintain their periodic framework structure even in solution phase, which provides potential possibilities for their application in solution processing technology.

[0005] Although XOFs show good prospects in terms of functionality and application potential, their application in solution processing technology still faces multiple technical challenges. The first is their insufficient solubility. Although XOFs have unique [NX + -N] The halogen bond structure has solubility to a certain extent, but its overall solubility is still limited, especially in certain specific solvents. This deficiency seriously restricts its handling and processing capabilities in liquid environments. Therefore, how to effectively improve the solubility of XOFs has become a key technical issue in realizing its wide application. The second is structural stability. During solution processing, it is crucial to maintain the periodic framework structure of XOFs. Many existing framework materials will undergo structural collapse in solution due to environmental changes, resulting in performance degradation. Therefore, the development of organic framework materials that can maintain a stable structure under various solvent conditions is a challenge that needs to be urgently addressed. Finally, there is functional customization. The functionality of XOFs is closely related to its structure. How to achieve customization of specific functions (such as piezoelectricity, adsorption or catalysis) through the rational design and synthesis of new halogen bond organic frameworks is the key to improving the application value of materials. It is necessary to explore how to introduce new functional groups or structural units without affecting the stability of the framework.

[0006] In summary, if the solubility, structural stability and multifunctional properties of XOFs can be further improved through reasonable design, they will become ideal candidate materials for devices and sensors that rely on solution processing technology, which will have positive significance for expanding their applications. Summary of the Invention

[0007] In view of the above-mentioned defects of the prior art, in a first aspect of the present invention, a method for preparing a solution-processable two-dimensional halogen-bonded organic framework with high synthesis efficiency and reduced production cost is provided, comprising the following steps:

[0008] (1) 7-tridecanone, NH4OAc, and NaBH3CN are added to a solvent to form a mixed solution, and the mixed solution is reacted under a protective atmosphere. After completion, the product is recovered to obtain compound 1, i.e., N-(1-hexylheptyl)amine;

[0009] (2) Perylene-3,4,9,10-tetracarboxylic dianhydride, compound 1, and imidazole are mixed, and then reacted under a protective atmosphere. After completion, the product is recovered to obtain compound 2;

[0010] (3) [Cp*RhCl2]2, AgSbF6 and solvent are mixed under a protective atmosphere, and then compound 2, NIS, Cu(OAc)2 and solvent are added and reacted. After completion, the product is recovered to obtain compound 3;

[0011] (4) Compound 3, 4-pyridylboronic acid, Cs2CO3, and Pd(PPh3)4 are added to a solvent and reacted under a protective atmosphere. After completion, the product is recovered to obtain PDI;

[0012] (5) AgBF4, PDI, and iodine are dissolved in solvents to form corresponding solutions, respectively. The PDI solution is then added to the AgBF4 solution. After mixing, an iodine solution is added to the resulting solution to react. After completion, the product is recovered to obtain XOF-PDI, a solution-processable two-dimensional halogen-bonded organic framework.

[0013] Compounds 1 and 2 were synthesized based on the method described in the literature (J. Am. Chem. Soc. 2020, 142, 4, 1686-1691). In the synthesis of compound 1, 21.2 mmol of 7-tridecanone, 211 mmol of NH₄OAc, and 21.2 mmol of NaBH₃CN were used. The solvent used was 80 mL of methanol. The reaction was carried out at room temperature for 48 hours.

[0014] In this field, product recovery generally includes operations such as product separation and purification, and technicians can use common technical means in the field to achieve this goal. Regarding the specific operational level, for example, when synthesizing compound 1 under laboratory conditions, thin-layer chromatography (TLC) can be used to detect the complete disappearance of the starting material (color development through anisaldehyde), and then the reaction is terminated by dropwise addition of concentrated hydrochloric acid. The reaction is then concentrated under reduced pressure, and the resulting solid is dispersed in water and adjusted to alkalinity with aqueous sodium hydroxide solution. The mixture is then extracted with dichloromethane, the organic phases are combined and washed with brine, dried, filtered, and the solvent is removed under reduced pressure to obtain compound 1. Those skilled in the art can also choose other appropriate methods based on the actual scale and conditions of the synthesis.

[0015] In the synthesis step of compound 2, the amount of perylene-3,4,9,10-tetracarboxylic dianhydride used was 0.76 mmol, the amount of compound 1 used was 1.91 mmol, and the amount of imidazole used was 55.44 mmol. The reaction temperature in this step was 180°C, and the reaction time was 4.5 hours.

[0016] For the specific operation level, for example, in the synthesis of compound 2 under laboratory conditions, after the reaction is completed, the reaction mixture can be cooled to near room temperature, then diluted with ethanol, followed by the addition of hydrochloric acid and precipitation by standing. The resulting precipitate is collected by suction filtration, washed with distilled water and dried under reduced pressure to obtain the crude product. Finally, using fast column chromatography on a silica gel column with dichloromethane / ethanol as the eluent, compound 2 can be obtained. Other suitable methods can also be selected by those skilled in the art according to the actual synthesis scale and conditions, etc.

[0017] Compound 3, compound 4 is synthesized based on the method provided in the literature (Org. Lett. 2017, 19, 5438−5441). Correspondingly, in the synthesis step of compound 3, the amount of [Cp*RhCl2]2 is 0.014 mmol, the amount of AgSbF6 is 0.17 mmol, the amount of compound 2 is 0.19 mmol, the amount of NIS is 1.53 mmol, and the amount of Cu(OAc)2 is 0.77 mmol; the solvent includes dichloroethane, and the total amount of solvent is 8 mL. The reaction temperature of this step is 80 ℃, and the reaction time is 96 h.

[0018] For the specific operation level, for example, in the synthesis of compound 3 under laboratory conditions, after cooling to room temperature after the reaction is completed, the resulting reaction mixture is diluted with a solvent, and saturated aqueous Na2S2O3 and brine are used for washing. The combined organic layer is dried after washing with brine. The product is purified by silica gel column chromatography using dichloromethane / petroleum ether as the eluent. Finally, compound 3 can be obtained by recrystallization with chloroform / methanol. Other suitable methods can also be selected by those skilled in the art according to the actual synthesis scale and conditions, etc.

[0019] In the synthesis step of compound 4, the amount of compound 3 is 0.16 mmol, the amount of 4-pyridylboronic acid is 1.88 mmol, the amount of Cs2CO3 is 3.13 mmol, the amount of Pd(PPh3)4 is 0.03 mmol, the type and volume ratio of the solvent is toluene:methanol:water=4:1:1, and the amount of solvent is 20-100 mL. The reaction temperature of this step is 85 ℃, and the reaction time is 48 h.

[0020] For the specific operation level, for example, in the synthesis of PDI under laboratory conditions, after cooling to room temperature after the reaction is completed, the product can be concentrated, then purified by flash column chromatography using CH2Cl2 / CH3OH / TEA as the eluent, and PDI can be obtained. Other suitable methods can also be selected by those skilled in the art according to the actual synthesis scale and conditions, etc.

[0021] Preferably, in step (5), 0.10-0.50 mmol of AgBF4 is dissolved in 1-10 mL of solvent to obtain an AgBF4 solution.

[0022] Preferably, in step (5), 0.05-0.25 mmol PDI is dissolved in 1-10 mL solvent to obtain a PDI solution.

[0023] Preferably, in step (5), 0.10-0.5 mmol of iodine is dissolved in 1-10 mL of solvent to obtain an iodine solution.

[0024] Preferably, in step (5), the type of solvent includes methanol.

[0025] Preferably, in step (5), the mixing treatment is carried out at room temperature for 1-5 h.

[0026] Preferably, in step (5), the reaction is carried out at room temperature and the reaction time is 1-3 days.

[0027] For specific operational aspects, such as synthesizing XOF-PDI under laboratory conditions, a PDI solution is preferably added dropwise to an AgBF4 solution. After the reaction, the solvent is evaporated under reduced pressure without heating, and the precipitate is dried in a vacuum overnight. The precipitate is then ultrasonically dispersed in 1,2-dichloroethane and finally dried in a vacuum to obtain XOF-PDI. Those skilled in the art may also select other appropriate methods based on the actual scale and conditions of the synthesis.

[0028] The main synthesis process of the present invention is as follows:

[0029]

[0030]

[0031]

[0032] .

[0033] As shown above, the present invention simplifies the synthesis process. The optimized synthetic route will greatly simplify the production process of XOFs, improve synthesis efficiency, and reduce production costs. This will lay the foundation for large-scale industrial production and promote the commercialization of this type of material. In addition, the preparation focuses on the selection of environmentally friendly solvents and materials during the synthesis and processing, which helps to reduce the impact on the environment and promote the practice of green chemistry.

[0034] In the second aspect of the present invention, a solution-processable two-dimensional halogen-bonded organic framework with high solubility, strong structural stability and multifunctional properties is provided, which is prepared using the preparation method provided by the first aspect of the present invention.

[0035] In the third aspect of the present invention, there is provided an application of the solution-processable two-dimensional halogen-bonded organic framework according to the second aspect of the present invention, specifically an application as a raw material in the preparation of sensors and electronic devices.

[0036] Based on the above technical solutions, the inventive concept and principle of the present invention is to significantly enhance the solubility of XOFs by introducing long-chain alkyl side chains and optimizing solvent selection, so that they can maintain good dispersibility in a variety of solvents:

[0037] (1) Increase intermolecular interactions in a solvent-repellent environment: Long-chain alkyl side chains have strong hydrophobicity and can form a stable hydrophobic effect in the solvent environment, thereby enhancing the solubility of the framework material in solvents of different polarities. This design enables the framework material to have good solubility in both polar and non-polar solvents.

[0038] (2) Reduce molecular stacking: The large size of the alkyl side chain can effectively increase the molecular distance of the framework material and reduce the π-π stacking effect between molecules. This effect of reducing stacking not only improves solubility but also preserves the structural integrity of the material, thus facilitating a periodic stable structure in solution.

[0039] (3) Improved flexibility and solution stability: The long-chain alkyl side chains introduce a certain degree of flexibility into the overall molecular structure, allowing the framework material to be more stably dispersed in the solvent. In addition, this flexibility also increases the fluidity of the material in the solution, further enhancing its solubility.

[0040] Therefore, the two-dimensional halogen-bonded organic framework can be dissolved in most organic solvents, such as high-boiling-point solvents such as DMSO and DMF, alcohol solvents such as ethanol and methanol, and halogenated solvents such as dichloromethane and dichloroethane.

[0041] This progress will greatly expand the application range of XOFs in liquid-phase processing technology. In addition, through cross-linking strategies and the introduction of functional groups, the structural stability of XOFs in solution environments is improved, ensuring that their periodic structure does not collapse during processing and application.

[0042] In this invention, PDI (perylene diimide) is one of the core functional groups. PDI's structure features a planar, large π-electron conjugated system, endowing it with high electron affinity and excellent optoelectronic properties, making it highly valuable in electronic and optical applications. In XOF-PDI, PDI not only provides strong π-π stacking ability but also further modulates the solubility and structural stability of the framework material through the introduction of long-chain alkyl side chains.

[0043] The XOF-PDI of the present invention achieves unique effects through the following mechanisms, which are specifically embodied in:

[0044] (1) Structural stability achieved through halogen bonds: Halogen bonds in XOF-PDI [NX + -N] binding provides strong intermolecular directionality, ensuring the stability of the periodic structure of the framework in solution.

[0045] (2) π-π stacking regulation based on PDI: The π-π stacking property of PDI enables XOF-PDI to possess electron transport capabilities that are not possessed by existing technologies (CN202311292812, CN202311783696). Due to the introduction of long-chain alkyl side chains, this stacking can be finely controlled, avoiding the solubility loss caused by excessive stacking, thereby effectively improving the processability of the framework material and the sustainability of the periodic structure in solution.

[0046] Improved solubility and solution processing adaptability: Through side chain engineering, the solvophobic effect of the long-chain alkyl groups enhances the framework's dispersibility in solvents of varying polarity, resulting in XOF-PDI exhibiting excellent solution processing adaptability. This effect, not seen in the prior art described above by the inventors' research group, underlies the present invention's broad potential for applications in sensors and flexible electronics.

[0047] These effects help improve the material's long-term reliability and performance consistency. Furthermore, by introducing specific functional groups into the framework, the present invention imparts multiple functionalities to XOFs, such as excellent piezoelectricity, electrical conductivity, and catalytic properties. This will enable these materials to possess even greater added value in applications such as sensors, electronic devices, and catalytic reactions.

[0048] Thanks to their excellent solubility and stability, XOFs can be combined with other materials (such as polyvinylidene fluoride (PVDF)) to create high-performance flexible sensors and electronic devices, broadening their application prospects in the electronics and sensor fields. By closely integrating with the industrial chain, this invention effectively transforms research results into marketable products, achieving a smooth transition from the laboratory to the market. This will accelerate the adoption of XOFs in practical applications and bring new technological and product innovations to related industries.

[0049] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0050] The present invention provides a method for preparing a solution-processable two-dimensional halogen bond organic framework, which has the advantages of high synthesis efficiency and reduced production costs.

[0051] The present invention provides a solution-processable two-dimensional halogen bond organic framework with high solubility, strong structural stability and multifunctional properties.

[0052] The present invention provides an application of a solution-processable two-dimensional halogen bond organic framework, which has broad prospects in the fields of electronics and sensors. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] Figure 1 PDI and XOF-PDI in dimethyl sulfoxide-d6 (600 MHz, 298 K) 1 H NMR spectrum;

[0054] Figure 2 I 3d X-ray photoelectron spectroscopy (XPS) of XOF-PDI;

[0055] Figure 3 From left to right in the middle are the N 1s XPS spectra of PDI and XOF-PDI;

[0056] Figure 4 is the Raman spectrum of XOF-PDI under 532 nm laser excitation;

[0057] Figure 5 Dynamic light scattering (DLS) images of PDI and XOF-PDI, and the dissolution process of XOF-PDI in methanol;

[0058] Figure 6 Schematic diagram of the manufacturing process of XOF-PDI / PVDF flexible piezoelectric sensor;

[0059] Figure 7 From left to right, the diagram shows the principle diagram of medium-voltage power sensing for human motion, the optical image and output voltage generated by human wrist flexion, and the optical image and output voltage generated by human elbow flexion.

[0060] Figure 8 For [NI + -N] Schematic diagram of the construction of connected XOF-PDI and the fabrication of flexible devices via solution processing. DETAILED DESCRIPTION

[0061] The present invention is further illustrated by way of examples below, but the present invention is not limited to the scope of the examples. Experimental methods in the following examples where specific conditions are not specified were performed according to conventional methods and conditions, or selected according to the product specifications.

[0062] Example 1

[0063] A method for preparing a solution-processable two-dimensional halogen-bonded organic framework comprises the following steps:

[0064] (1) A 250 mL round-bottom flask was stirred with a magnetic stirrer, and 7-tridecanone (4.2 g, 21.2 mmol), NH4OAc (16.3 g, 211 mmol) and NaBH3CN (1.33 g, 21.2 mmol) were added thereto and dissolved in 80 mL of methanol under argon protection. The mixture was stirred at room temperature for 48 h until TLC showed that the starting material completely disappeared (color development by anisaldehyde), and then the reaction was terminated by dropwise addition of concentrated hydrochloric acid. The reactants were concentrated under reduced pressure, and the resulting solid was dispersed in 250 mL of water and adjusted to pH = 10 with saturated NaOH aqueous solution. The mixture was extracted with dichloromethane, the organic phases were combined and washed with brine, and then dried over MgSO4. After filtration, the solvent was removed under reduced pressure to obtain compound 1, i.e., N-(1-hexylheptyl)amine, which was used directly in the next reaction without further purification.

[0065] (2) Perylene-3,4,9,10-tetracarboxylic dianhydride (0.30 g, 0.76 mmol), compound 1 (0.38 g, 1.91 mmol) and imidazole (3.8 g, 55.44 mmol) were added to a 100 mL round-bottom flask under argon protection. The reaction mixture was stirred at 180 °C for 4.5 h. After the reaction mixture was cooled to near room temperature, it was diluted with ethanol, and then hydrochloric acid (2 mol / L, 50 mL) was added. The mixture was allowed to stand for 1 h. The resulting precipitate was collected by filtration, washed with distilled water and dried under reduced pressure to obtain a crude product. The dark red powder of compound 2 (0.32 g, yield 60%) was obtained by flash column chromatography on silica gel column chromatography using dichloromethane / ethanol as eluent.

[0066] (3) A magnetic stirrer was added to a 50 mL Schlenk tube, and [Cp*RhCl2]2 (0.014 mmol, 8.9 mg) and AgSbF6 (0.17 mmol, 59.4 mg) were added to dry dichloroethane (4.0 mL) under argon atmosphere. The mixture was stirred at room temperature for 30 min. Compound 2 (0.19 mmol, 145.0 mg), NIS (1.53 mmol, 345.6 mg), Cu(OAc)2 (0.77 mmol, 139.5 mg) and dry dichloroethane (4.0 mL) were then added in sequence. The tube was sealed and stirred at 80 °C for 96 min. h; After the reaction was cooled to room temperature, the reaction mixture was diluted with CH2Cl2 and washed with saturated Na2S2O3 aqueous solution and brine. The combined organic layer was washed with brine and dried over MgSO4. The product was purified by silica gel column chromatography using dichloromethane / petroleum ether as eluent and finally recrystallized from chloroform / methanol to obtain compound 3 (196 mg, yield 81%);

[0067] (4) Compound 3 (0.19 g, 0.16 mmol), 4-pyridylboronic acid (0.23 g, 1.88 mmol), anhydrous Cs2CO3 (1.02 g, 3.13 mmol) and Pd(PPh3)4 (36.2 mg, 0.03 mmol) were added to the solution after argon treatment for 30 min, and stirred at 85 °C for 48 h. After the reaction was cooled to room temperature, the product was concentrated to obtain a crude product, which was subjected to flash column chromatography using CH2Cl2:CH3OH:TEA (80:1:0.5, v / v) as an eluent to obtain red powdered PDI (0.15 g, yield 60%).

[0068] (5) After dissolving AgBF4 (18.3 mg, 0.10 mmol) in 1 mL of methanol, the solution was added dropwise to a 1 mL methanol solution of PDI (50.0 mg, 0.05 mmol) and stirred at room temperature for 1 h. Then, a solution of iodine (23.9 mg, 0.10 mmol) dissolved in 1 mL of methanol was added to the solution. The solution was allowed to stand at room temperature for 3 days. The solvent was evaporated under reduced pressure without heating, and the precipitate was dried in a vacuum overnight. The solution was then ultrasonically dispersed at 50 °C for 24 h, heated to 110 °C, and dispersed in 1,2-dichloroethane for 3 h. Finally, it was dried in a vacuum to obtain XOF-PDI, a solution-processable two-dimensional halogen-bonded organic framework.

[0069] Example 2

[0070] This example characterizes the structure of the prepared XOF-PDI. 1 The formation process of XOF-PDI was monitored by H NMR spectroscopy, and the results were as follows: Figure 1 When PDI coordinates with Ag+ / I+ to form MOF-PDI and XOF-PDI, it will cause a significant disturbance in the magnetic environment of PDI. After the formation of XOF-PDI, the Ha and Hb peaks show obvious low-field shifts (ΔδHa = 0.151 ppm, ΔδHb = 0.238 ppm), which is attributed to the [NI + The electron density of the pyridine ring decreases upon formation of the [-N] halogen bond. In contrast, the Hc signal shift on the internal aromatic ring is smaller (ΔδHc = 0.004 ppm) because it is farther away from the pyridine ring and is less affected by the change in electron density.

[0071] Example 3

[0072] This embodiment uses X-ray photoelectron spectroscopy to further analyze the surface chemical state of XOF-PDI and PDI. The I 3d XPS spectrum of XOF-PDI is as follows: Figure 2 XPS shows two I 3d main peak signals at 623.0 eV (I 3d5 / 2) and 634.4 eV (I 3d3 / 2), which indicates the presence of I+ ions and corresponds to the formation of iodine in [NI + -N] spin-orbit splitting in halogen bonds.

[0073] The N 1s XPS spectra of PDI and XOF-PDI are as follows: Figure 3 XPS analysis also revealed a gradual increase in the N 1s binding energy with the addition of I+ from PDI to XOF-PDI, consistent with a decrease in the electron cloud density of the pyridine ring. No Ag 3d signal was detected in XPS, confirming the complete removal of Ag+, which was attributed to the filtration separation of insoluble AgI.

[0074] It should be noted that the above effects differ from the effects of the inventor's research group's prior research (CN202311783696) in the following ways:

[0075] Improvement of crystallinity and structural stability: The literature mentioned that high crystallinity can be obtained by improving the preparation process, but without using the same approach, the present invention [NX + The three-center, four-electron combination of the [-N] halogen bond stabilizes the material's crystallinity and framework structure. The introduction of long-chain alkyl side chains further reduces the effects of molecular stacking and π-π stacking on the crystalline structure, thereby improving overall crystallinity while maintaining its periodicity in solution.

[0076] Versatility Empowered by Side Chain Engineering: The side chain engineering of this invention not only enhances the material's crystallinity and solubility but also further expands its adaptability in solution processing. This molecularly designed solubility enhancement opens new possibilities for subsequent applications of XOFs, such as solution-based flexible electronics, a functional advantage not previously achieved.

[0077] Example 4

[0078] This example verifies the structure and solubility of XOF-PDI. First, the Raman spectrum of XOF-PDI under 532 nm laser excitation is characterized. Figure 4 The Raman spectrum of XOF-PDI shows that -1 The obvious G peak at , similar to the E2g mode of graphene, confirms the existence of two-dimensional structure in XOF-PDI.

[0079] XOF-PDI was measured using dynamic light scattering, and the results were as follows: Figure 5 The results show that the particle size of XOF-PDI increases in methanol solution, which also supports the formation of a two-dimensional framework structure. The photo in the figure reflects the dissolution process of XOF-PDI in methanol with Tyndall effect.

[0080] The excellent solubility of XOF-PDI is attributed to the combination of side chain engineering and electrostatic repulsion (the introduction of alkyl side chains and charged [NI + -N] halogen bond), which makes it exhibit excellent solubility in various organic solvents, demonstrating the successful preparation of a new type of solution-processable XOF material.

[0081] Example 5

[0082] In this example, sensors and electronic components were prepared using XOF-PDI as a raw material to study their effects in practical applications.

[0083] The steps for preparing PVDF naturally evaporated film are as follows:

[0084] 2.0 g of PVDF was dissolved in 10 mL of a mixed solution of DMF and acetone (2:3, v / v). After ultrasonic dispersion, the solution was poured into a 30 cm diameter Petri dish and naturally evaporated at 60 °C for 2 days to form a complete film.

[0085] Preparation of XOF-PDI / PVDF composite electrospun films, such as Figure 6 As shown, the steps are as follows:

[0086] 1.0 g of PVDF was dispersed in a mixed solvent of DMF and acetone in a 4:6 volume ratio. After sonication for 1 hour, 40.0 mg of XOF-PDI was added and sonication continued for 0.5 hour. The fibers were then electrospun at a feed rate of 1 mL / h, a tip-to-collector distance of 15 cm, a voltage of 20 kV, and ambient conditions of 25 ± 2°C and 50% ± 5% humidity. The fibers were collected at a collector speed of 600 rpm. After spinning, the films were dried at 60°C to remove any residual solvent.

[0087] Preparation and testing of piezoelectric sensors:

[0088] The XOF-PDI / PVDF composite electrospun film was sandwiched between two electrodes, using aluminum foil to prevent triboelectric signal interference. Wires connecting the upper and lower electrodes were then encapsulated with Kapton tape. Flexible sensors made from the XOF-PDI / PVDF composite were placed on different parts of the human body (e.g., joints, wrists, elbows), ensuring that the outer side of the sensor was in contact with the stretched area and the inner side with the compressed area to capture positive and negative signals.

[0089] Sensor signal test:

[0090] Schematic diagram of medium-voltage power sensing for human motion, as well as the optical image and output voltage generated by human wrist flexion motion, and the test results of the optical image and output voltage generated by human elbow flexion motion. Figure 7 shown.

[0091] For testing at a joint: Monitor the positive signal from the outer sensor when the joint is moved and the negative signal from the inner sensor when pressure is applied.

[0092] For wrist testing: Place the sensor on your wrist, move your wrist back and forth, and observe the corresponding positive and negative signals generated by the sensor.

[0093] For testing at the elbow: Place the sensor on the inside of the elbow and record the negative signal generated by the sensor as the arm is raised. Note the significant increase in the elbow signal compared to the wrist signal, indicating that the elbow is subjected to greater mechanical force.

[0094] [NI + The construction of XOF-PDI and the fabrication of flexible devices by solution processing are described in detail. Figure 8As shown, combined with the above test results, the present invention significantly enhances the solubility of XOFs by introducing long-chain alkyl side chains and optimizing solvent selection, enabling them to maintain good dispersibility in a variety of solvents. This greatly expands the scope of application of XOFs in liquid phase processing technology. In addition, through cross-linking strategies and the introduction of functional groups, the structural stability of XOFs in a solution environment is improved, ensuring that their periodic structure does not collapse during processing and application. This will help improve the long-term reliability and performance consistency of the material. Not only that, the present invention also gives XOFs a variety of functions, such as excellent piezoelectricity, conductivity and catalytic properties, by introducing specific functional groups into the framework. This will give these materials higher added value in applications such as sensors, electronic devices and catalytic reactions.

[0095] The above describes in detail the preferred embodiments of the present invention. It should be understood that those skilled in the art can make numerous modifications and variations based on the concepts of the present invention without inventive effort. Therefore, any technical solutions that can be derived by those skilled in the art through logical analysis, reasoning, or limited experimentation based on the concepts of the present invention and the prior art should be within the scope of protection defined by the claims.

Claims

1. A method for preparing a solution-processable two-dimensional halogen-bonded organic framework, characterized in that: The steps include: (1) 7-tridecanone, NH4OAc, and NaBH3CN are added to a solvent to form a mixed solution, and the mixed solution is reacted under a protective atmosphere. After completion, the product is recovered to obtain compound 1, i.e., N-(1-hexylheptyl)amine; (2) Perylene-3,4,9,10-tetracarboxylic dianhydride, compound 1, and imidazole are mixed, and then reacted under a protective atmosphere. After completion, the product is recovered to obtain compound 2; (3) [Cp*RhCl2]2, AgSbF6 and solvent are mixed under a protective atmosphere, and then compound 2, NIS, Cu(OAc)2 and solvent are added and reacted. After completion, the product is recovered to obtain compound 3; (4) Compound 3, 4-pyridylboronic acid, Cs2CO3, and Pd(PPh3)4 are added to a solvent and reacted under a protective atmosphere. After completion, the product is recovered to obtain PDI; (5) AgBF4, PDI, and iodine are dissolved in solvents to form corresponding solutions, respectively. The PDI solution is then added to the AgBF4 solution. After mixing, an iodine solution is added to the resulting solution to react. After completion, the product is recovered to obtain XOF-PDI, a solution-processable two-dimensional halogen-bonded organic framework.

2. The method for preparing a solution-processable two-dimensional halogen-bonded organic framework according to claim 1, wherein: In the step (5), 0.10-0.50 mmol of AgBF4 is dissolved in 1-10 mL of solvent to obtain an AgBF4 solution.

3. The method for preparing a solution-processable two-dimensional halogen-bonded organic framework according to claim 1, wherein: In the step (5), 0.05-0.25 mmol of PDI is dissolved in 1-10 mL of solvent to obtain a PDI solution.

4. The method for preparing a solution-processable two-dimensional halogen-bonded organic framework according to claim 1, wherein: In the step (5), 0.10-0.5 mmol of iodine is dissolved in 1-10 mL of solvent to obtain an iodine solution.

5. The method for preparing a solution-processable two-dimensional halogen-bonded organic framework according to claim 1, wherein: In the step (5), the type of solvent includes methanol.

6. The method for preparing a solution-processable two-dimensional halogen-bonded organic framework according to claim 1, wherein: In the step (5), the mixing process is carried out at room temperature for 1-5 hours.

7. The method for preparing a solution-processable two-dimensional halogen-bonded organic framework according to claim 1, wherein: In the step (5), the reaction is carried out at room temperature and the reaction time is 1-3 days.

8. A solution-processable two-dimensional halogen-bonded organic framework, characterized by: The method is as described in any one of claims 1 to 7.

9. A use of the solution-processable two-dimensional halogen-bonded organic framework according to claim 8, characterized in that: Used as raw materials in the preparation of sensors and electronic devices.

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