Fully-conjugated covalent organic framework material as well as preparation method and application thereof
The construction of fully conjugated COFs connected by carbon-carbon bonds by solvothermal method solves the problem of insufficient stability and crystallinity of existing COFs, achieves high stability and excellent photoelectric performance, and expands its application in multiple fields.
Patent Information
- Application Number
- CN202510774670.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-11
- Publication Date
- 2025-08-15
AI Technical Summary
The existing covalent organic frame materials (COFs) have shortcomings in stability and crystallinity, especially the weak crystallinity of fully conjugated COFs connected with carbon-carbon bonds, which affects their application in optoelectronic devices and other fields.
The sp2 carbon bond was constructed by coupling reaction, and fully conjugated COFs connected with carbon-carbon bonds were prepared by solvothermal method to form a material with high stability and high crystallinity.
It achieves high stability and excellent photoelectric properties of the material, and is suitable for optoelectronic devices, adsorption, catalysis, sensors, energy storage and conversion, gas storage and separation, nanofiltration materials and other fields.
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Figure CN120484236A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of covalent organic framework materials, and in particular relates to a fully conjugated covalent organic framework material and a preparation method and application thereof. Background Art
[0002] Covalent organic frameworks (COFs) are an emerging class of crystalline porous materials (CPMs) composed of organic building blocks linked by strong covalent bonds, consisting of light elements such as carbon (C), oxygen (O), boron (B), nitrogen (N), and hydrogen (H). They have attracted widespread attention due to their unique characteristics of light weight, excellent thermal stability, permanent and periodic porosity, tunable pore size, and large surface area. Over the past decade, COFs have attracted significant attention in a variety of applications, such as gas storage and separation, adsorption, catalysis, sensors, optoelectronic devices, drug delivery, and energy storage and conversion. Unlike traditional amorphous organic polymers, COFs allow reversible condensation between building blocks, primarily synthesized using reversible condensation reactions of boroxines or imines. Error correction during crystallization leads to the construction of highly ordered crystalline structures. As an emerging class of porous materials, fully conjugated COFs are characterized by high stability and crystallinity. Their well-defined π electron delocalization and porosity exhibit excellent optoelectronic properties.
[0003] Most COFs are constructed using reversible covalent bonds linked by heteroatoms, such as boronate and imine bonds. These bonds exhibit self-regulating properties and facilitate the formation of ordered structures. However, these bonding schemes result in significant stability drawbacks for COFs. The intralayer π-electron delocalization of heteroatom-linked COFs can be disrupted by non-conjugated polar bonds (such as boronate or imine bonds), hindering their application in applications requiring highly delocalized π-electron systems, such as organic semiconductors, photocatalysis, and ferromagnetic materials. Therefore, the preparation of stable, fully conjugated carbon-carbon bonded COFs with excellent optoelectronic properties is a key challenge in this field. To overcome these limitations, the use of irreversible covalent bonds to prepare stable and highly crystalline COFs is considered an important approach to address this challenge. Compared to the extensively reported heteroatom-linked COFs, carbon-carbon bonded COFs are an emerging class of COFs. Current carbon-carbon bonded fully conjugated COFs exhibit relatively poor crystallinity. This is particularly challenging due to their generally low reversibility, which hinders self-regulation. The design and preparation of highly crystalline and stable novel fully conjugated COFs for application in optoelectronic devices remains a major challenge. To address this issue, the present invention proposes a solvothermal method for synthesizing carbon-carbon bonded fully conjugated COFs using a coupling reaction. Summary of the Invention
[0004] Aiming at the problems of poor stability and weak conjugation of the reversible covalent bond commonly used in constructing COFs, the present invention provides a fully conjugated covalent organic framework material and its preparation method and application, and adopts coupling reaction to construct sp 2 Carbon bond strategy, through the solvothermal method to obtain carbon-carbon bond connected fully conjugated COFs, sp 2 The carbon conjugated framework has the advantages of high stability, greater electron delocalization and adjustable porosity, which makes the material exhibit excellent crystallinity, stability and optoelectronic properties.
[0005] In a first aspect, the present invention provides a fully conjugated covalent organic framework material, which is a fully conjugated two-dimensional organic crystalline polymer constructed by a monomer A having an Ar1 structure and a monomer B having an Ar2 structure through carbon-carbon bonds.
[0006] Monomer A is one of the following three structures: a C3 symmetric unit with 3 reaction sites, a C2 symmetric unit with 4 reaction sites, and a C3 symmetric unit with 6 reaction sites; monomer B is a linear C2 symmetric unit with 2 reaction sites; among them, C2, C3, and C4 represent symmetrical building units.
[0007] The reaction site is a functional group in the building block that participates in forming a covalent bond. The functional group of monomer A and the functional group of monomer B form a covalent bond through a carbon-carbon coupling reaction.
[0008] Furthermore, the functional group in monomer A is , the functional group in monomer B is ; Or, the functional group in monomer A is , the functional group in monomer B is .
[0009] Furthermore, when monomer A is a C3 symmetric unit having three reaction sites, Ar1 is selected from one of the following structures:
[0010] Among them, the dotted line represents the connection bond between the parent group and the functional group (corresponding to the reaction site) in Ar1.
[0011] Furthermore, when monomer A is a C2 symmetric unit having four reaction sites, Ar1 is selected from one of the following structures:
[0012] Among them, the dotted line represents the connection bond between the parent group and the functional group (corresponding to the reaction site) in Ar1.
[0013] Furthermore, when monomer A is a C3 symmetric unit having 6 reaction sites, Ar1 is selected from one of the following structures:
[0014] Among them, the dotted line represents the connection bond between the parent group and the functional group (corresponding to the reaction site) in Ar1.
[0015] Further, Ar2 is selected from one of the following structures: Among them, the dotted line represents the connection bond between the parent group and the functional group (corresponding to the reaction site) in Ar2.
[0016] Furthermore, the fully conjugated covalent organic framework material is one of the following structures:
[0017]
[0018]
[0019]
[0020] The above structural formula represents the smallest structural unit in the fully conjugated covalent organic framework material, and the wavy lines represent omitted repeated structural units.
[0021] In a second aspect, the present invention provides a method for preparing a fully conjugated covalent organic framework material, comprising the following steps: Monomer A, monomer B and a catalyst are added to a reaction tube, and then an organic solvent and an alkaline aqueous solution are added to form a mixed solution, and the mixed solution is ultrasonically treated to form a dispersion; the reaction tube is subjected to liquid nitrogen freezing, vacuuming, and thawing cycle degassing treatment, and the reaction is carried out at 20-200°C for 1-30 days. After the reaction is completed, the reactants are filtered and collected, and then washed and dried to obtain a fully conjugated covalent organic framework material.
[0022] Furthermore, the organic solvent is one of toluene, dioxane, trimethylbenzene, dimethyl sulfoxide, dimethylformamide, and tetrahydrofuran.
[0023] Furthermore, the alkaline substance in the alkaline aqueous solution is one of sodium carbonate, potassium carbonate, cesium carbonate, potassium phosphate, potassium tert-butoxide, sodium tert-butoxide, sodium hydroxide, and potassium hydroxide.
[0024] Furthermore, the catalyst is one of Pd(PPh3)4, Pd(OAc)2, Pd(dba)2, PdCl2(dppf), and PdCl2(PPh3)2.
[0025] Furthermore, the solvent used for washing is one or more of methanol, ethanol, tetrahydrofuran, dichloromethane, acetone, and water.
[0026] In a third aspect, the present invention also provides applications of the fully conjugated covalent organic framework material, which is used in optoelectronic devices, adsorption, catalysis, sensors, energy storage and conversion, gas storage and separation, nanofiltration materials and other fields.
[0027] Beneficial Effects: The method for preparing the fully conjugated covalent organic framework (COF) material disclosed herein differs from conventional covalent organic frameworks in that it is composed of irreversible covalent bonds. Carbon-carbon bonds are introduced into the COF backbone to replace heteroatom bonds, ensuring stability while maintaining high crystallinity. The unique reaction synthesis mechanism and high yield of the present invention contribute to the product's excellent stability and optoelectronic properties, enabling applications in optoelectronic devices, adsorption, catalysis, sensors, energy storage and conversion, gas storage and separation, and nanofiltration materials. BRIEF DESCRIPTION OF THE DRAWINGS
[0028] Figure 1 This is the Fourier infrared spectrum of the fully conjugated covalent organic framework material prepared in Example 1-4.
[0029] Figure 2 This is the experimental powder X-ray diffraction spectrum of the fully conjugated covalent organic framework material prepared in Example 1-4.
[0030] Figure 3 These are experimental SEM images of the fully conjugated covalent organic framework materials prepared in Examples 1-4.
[0031] Figure 4 TGA spectra of the thermodynamic stability test of the fully conjugated covalent organic framework materials prepared in Examples 2 and 4.
[0032] Figure 5 These are the UV-visible absorption spectra and photoluminescence spectra of the fully conjugated covalent organic framework materials prepared in Examples 2-5.
[0033] Figure 6 Graphs showing the electrical properties of the fully conjugated covalent organic framework materials prepared in Examples 1-2 and 6.
[0034] Figure 7 Graph showing the device performance of the fully conjugated covalent organic framework materials prepared in Examples 2 and 5. DETAILED DESCRIPTION
[0035] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments:
[0036] Example 1 Weigh (50.2 mg, 0.11 mmol), (107.2 mg, 0.34 mmol) and tetrabutylammonium bromide (15.82 mg, 0.05 mmol) were added to a reaction tube, and 10 mL of KOH aqueous solution (168.1 mg, 0.3 mmol) was prepared. 2 mL of KOH aqueous solution was added to the tube, and 6 mL of toluene was added. The mixture was ultrasonically dispersed to form a uniform dispersion. Pd(PPh3)4 (7.9 mg, 0.007 mmol) was then quickly added to the mixed solution. The reaction tube was sealed and frozen-evacuated-thawed with liquid nitrogen. The mixed solution was stirred in an oil bath at 120°C for 48 hours. The reaction was shut down and allowed to cool to room temperature. It was then filtered and the filtered solid was washed with tetrahydrofuran and acetone in a Soxhlet extractor to remove unreacted starting materials. The resulting solid was dried for 24 hours to obtain the target product with a yield of 61%. It is numbered COF-9 and its structure is shown below:
[0037] The Fourier infrared spectrum of the covalent organic framework material prepared in this embodiment is as follows: Figure 1 Shown: COF-9 at 1482 cm -1 C=C stretching vibration at 1002 cm -1 In-plane bending vibration of CC at 810 cm -1 The appearance of these three characteristic peaks proves the integrity of the structure; its X-ray diffraction pattern is as follows Figure 2 (a) shows the experimental PXRD curve at 2 θ =1.9°, indicating that the material is highly crystalline. The SEM characterization of the fully conjugated organic framework material is shown in Figure 3 As shown in (a), the morphology of the fully conjugated covalent organic framework material is lamellar; the thermal decomposition temperature of the material is 387.1 ° C, indicating that it has good thermal stability. The temperature-resistance curve of the fully conjugated organic framework material is characterized as follows Figure 6 As shown in (a), as the temperature rises, the resistance and resistivity of COF-9 decrease, showing the electrical properties of semiconductor materials.
[0038] Example 2 Weigh (52.3 mg, 0.1 mmol), (48.5 mg, 0.29 mmol) and tetrabutylammonium bromide (10.1 mg, 0.03 mmol) were added to a reaction tube, and 10 mL of NaOH aqueous solution (200 mg, 0.5 mmol) was prepared. 2 mL of NaOH aqueous solution was added to the tube, and 6 mL of trimethylbenzene was added. The mixture was ultrasonically dispersed to form a uniform dispersion. Pd(OAc)2 (5.2 mg, 0.005 mmol) was then quickly added to the mixed solution. The reaction tube was sealed and frozen, vacuumized, and thawed with liquid nitrogen. The mixed solution was stirred in an oil bath at 90°C for 12 hours. The reaction was shut down and allowed to cool to room temperature. It was then filtered and the filtered solid was washed with dichloromethane and acetone in a Soxhlet extractor to remove unreacted starting materials. The resulting solid was dried for 24 hours to obtain the target product with a yield of 66%. It is numbered COF-7 and its structure is shown below:
[0039] The Fourier infrared spectrum of the covalent organic framework material prepared in this embodiment is as follows: Figure 1 Shown: COF-7 at 1403 cm -1 C=C stretching vibration at 1055 cm -1 In-plane bending vibration of CC at 810 cm -1 The appearance of these three characteristic peaks proves the integrity of the structure; its X-ray diffraction is as follows Figure 2 (b) shows the experimental PXRD curve at 2 θ =2°, there is a sharp diffraction peak, indicating that the material has a high degree of crystallinity. The TGA spectrum of the thermodynamic stability test is as follows Figure 4 As shown: the thermal decomposition temperature of the material is 449 ° C, indicating that it has good thermal stability; the SEM characterization of the fully conjugated organic framework material is shown in Figure 3 As shown in (b), it shows that the morphology of the fully conjugated covalent organic framework material is lamellar. The UV-visible absorption spectrum and photoluminescence spectrum of the fully conjugated organic framework material are shown in Figure 5 As shown: Figure 5 (a) shows that COF-7 exhibits double absorption peaks at 299 nm and 375 nm. Figure 5 (b) shows a strong emission peak at around 470 nm, showing green fluorescence emission with a fluorescence quantum efficiency of 8.13%. The temperature-resistance curve of the fully conjugated organic framework material is characterized as follows Figure 6 As shown in (b), as the temperature rises, the resistance and resistivity of COF-7 decrease, showing the electrical properties of semiconductor materials; the fully conjugated organic framework material is used as the light-emitting layer in the OLED device to conduct electroluminescence performance testing, and the results are as follows Figure 7(a) shows: the turn-on voltage is 5.5V and the brightness is 70 cd / m 2 .
[0040] Example 3 Weigh (51.3 mg, 0.1 mmol), (70.1 mg, 0.3 mmol) and tetrabutylammonium bromide (12.3 mg, 0.04 mmol) were added to a reaction tube, and 10 mL of K2CO3 aqueous solution (691.05 mg, 0.5 mmol) was prepared. 2 mL of K2CO3 aqueous solution was added to the tube, followed by 6 mL of dioxane and sonication to form a uniform dispersion. Pd(dba)2 (6.12 mg, 0.005 mmol) was then quickly added to the mixed solution. The reaction tube was sealed and frozen, vacuumed, and thawed with liquid nitrogen. The mixed solution was stirred in an oil bath at 80°C for 144 hours. The reaction was shut down and allowed to cool to room temperature. It was then filtered and the filtered solid was washed with tetrahydrofuran and ethanol in a Soxhlet extractor to remove unreacted starting materials. The resulting solid was dried for 24 hours to obtain the target product with a yield of 68%. It is numbered COF-10 and its structure is shown below:
[0041] The Fourier infrared spectrum of the covalent organic framework material prepared in this embodiment is as follows: Figure 1 Shown: COF-10 at 1400 cm -1 C=C stretching vibration at 1003 cm -1 In-plane bending vibration of CC at 813 cm -1 The appearance of these three characteristic peaks proves the integrity of the structure; its X-ray diffraction is as follows Figure 2 (c) shows the experimental PXRD curve at 2 θ = 2°, indicating that the material is highly crystalline. The SEM characterization of the fully conjugated organic framework material is shown in Figure 3 As shown in (c), the morphology of the fully conjugated covalent organic framework material is lamellar; the thermal decomposition temperature of the material is 356.2℃, indicating that it has good thermal stability; the UV-visible absorption spectrum and photoluminescence spectrum of the fully conjugated organic framework material are shown in Figure 5 As shown: Figure 5 (a) shows that COF-10 exhibits a broad absorption peak at 410 nm. Figure 5 Middle (b) shows a strong emission peak at around 530 nm, exhibiting yellow fluorescence emission with a fluorescence quantum efficiency of 33.43%.
[0042] Example 4 Weigh (51.5 mg, 0.07 mmol), (48.1 mg, 0.29 mmol) and tetrabutylammonium bromide (10.3 mg, 0.03 mmol) were added to a reaction tube, and 10 mL of Na2CO3 aqueous solution (529.95 mg, 0.5 mmol) was prepared. 2 mL of Na2CO3 aqueous solution was added to the tube, followed by 6 mL of trimethylbenzene and sonication to form a uniform dispersion. PdCl2(PPh3)2 (5.1 mg, 0.004 mmol) was then quickly added to the mixed solution. The reaction tube was sealed and frozen with liquid nitrogen, vacuumed, and thawed. The mixed solution was stirred in an oil bath at 180°C for 72 hours. The reaction was shut down and allowed to cool to room temperature. It was then filtered and the filtered solid was washed with tetrahydrofuran and acetone in a Soxhlet extractor to remove unreacted starting materials. The resulting solid was dried for 24 hours to obtain the target product with a yield of 64% and designated COF-5. Its structure is shown below:
[0043] The Fourier infrared spectrum of the covalent organic framework material prepared in this embodiment is as follows: Figure 1 Shown: COF-5 at 1485 cm -1 C=C stretching vibration at 1004 cm -1 In-plane bending vibration of CC at 812 cm -1 The appearance of these three characteristic peaks proves the integrity of the structure; its X-ray diffraction pattern is as follows: Figure 2 (d) shows the experimental PXRD curve at 2 θ = 2.1°, indicating that the material is highly crystalline. The TGA spectrum of the thermodynamic stability test is as follows: Figure 4 As shown: the thermal decomposition temperature of the material is 400.2℃, indicating that it has good thermal stability; the SEM characterization of its fully conjugated organic framework material is shown in Figure 3 As shown in (d), it shows that the morphology of the fully conjugated covalent organic framework material is lamellar; the UV-visible absorption spectrum and photoluminescence spectrum of the fully conjugated organic framework material are shown in Figure 5 As shown: Figure 5 (a) shows that COF-5 exhibits a broad absorption peak at 325 nm. Figure 5 Middle (b) shows a strong emission peak around 408 nm, exhibiting blue fluorescence emission.
[0044] Example 5 Weigh (51.7 mg, 0.14 mmol), (118.2 mg, 0.4 mmol) and tetrabutylammonium bromide (17.2 mg, 0.05 mmol) were added to a reaction tube, and 10 mL of Cs2CO3 aqueous solution (1629.1 mg, 0.5 mmol) was prepared. 2 mL of Cs2CO3 aqueous solution was added to the tube, and 6 mL of toluene was added and sonicated to form a uniform dispersion. PdCl2(dppf) (8.5 mg, 0.007 mmol) was then quickly added to the mixed solution. The reaction tube was sealed and frozen-evacuated-thawed with liquid nitrogen. The mixed solution was stirred in an oil bath at 75°C for 24 hours. The reaction was shut down and allowed to cool to room temperature. It was then filtered and the filtered solid was washed with methanol and acetone in a Soxhlet extractor to remove unreacted starting materials. The resulting solid was dried for 24 hours to obtain the target product with a yield of 48%. It is numbered COF-2 and its structure is shown below:
[0045] The UV-visible absorption spectrum and photoluminescence spectrum of the covalent organic framework material prepared in this embodiment are as follows: Figure 5 As shown: Figure 5 (a) shows that COF-2 exhibits a double peak absorption at 295 nm and 475 nm. Figure 5 (b) shows a strong emission peak at around 630 nm, showing red fluorescence emission; the PXRD curve of the material is at 2 θ = 2.2°, indicating that the material is highly crystalline. The thermal decomposition temperature of the material is 385.6°C, indicating that it has good thermal stability. The fully conjugated organic framework material is used as the light-emitting layer in the OLED device to conduct electroluminescence performance testing. The results are as follows: Figure 7 (b) shows the turn-on voltage is 10 V and the brightness is 40 cd / m 2 .
[0046] Example 6 Weigh (50.2 mg, 0.13 mmol), (93.8 mg, 0.4 mmol) and tetrabutylammonium bromide (14.42 mg, 0.04 mmol) were added to a reaction tube, and 10 mL of K3PO4 aqueous solution (1061.4 mg, 0.3 mmol) was prepared. 2 mL of K3PO4 aqueous solution was added to the tube, followed by 6 mL of dimethylformamide and sonication to form a uniform dispersion. Pd(PPh3)4 (7.2 mg, 0.006 mmol) was then quickly added to the mixed solution. The reaction tube was sealed and frozen, vacuumed, and thawed with liquid nitrogen. The mixed solution was stirred in an oil bath at 150°C for 108 hours. The reaction was shut down and allowed to cool to room temperature. It was then filtered and the filtered solid was washed sequentially with tetrahydrofuran and dichloromethane in a Soxhlet extractor to remove unreacted starting materials. The resulting solid was dried for 24 hours to obtain the target product with a yield of 51%. It is numbered COF-3 and its structure is shown below:
[0047] The temperature-resistance curve of the covalent organic framework material prepared in this embodiment is characterized as follows Figure 6 As shown in (a), as the temperature rises, the resistance and resistivity of COF-3 decrease, showing the electrical properties of semiconductor materials; the PXRD curve of the material is at 2 θ =2°, indicating that the material is highly crystalline. The thermal decomposition temperature of the material is 413.2°C, indicating that it has good thermal stability.
[0048] Example 7 Weigh (52.3 mg, 0.07 mmol), (45.2 mg, 0.27 mmol) and tetrabutylammonium bromide (9.8 mg, 0.03 mmol) were added to a reaction tube, and 10 mL of potassium tert-butoxide aqueous solution (561.1 mg, 0.5 mmol) was prepared. 2 mL of potassium tert-butoxide aqueous solution was added to the tube, followed by 6 mL of dimethyl sulfoxide and sonication to form a uniform dispersion. Pd(OAc)2 (4.91 mg, 0.004 mmol) was then quickly added to the mixed solution. The reaction tube was sealed and frozen, vacuumized, and thawed with liquid nitrogen. The mixed solution was stirred in an oil bath at 60°C for 96 hours. The reaction was shut down and allowed to cool to room temperature. It was then filtered and the filtered solid was washed with tetrahydrofuran and acetone in a Soxhlet extractor to remove unreacted starting materials. The resulting solid was dried for 24 hours to obtain the target product, numbered COF-6, with the structure shown below:
[0049] The PXRD curve of the covalent organic framework material COF-6 prepared in this example is 2 θ =2.2°, indicating that the material is highly crystalline. The temperature-resistance curve shows that as the temperature rises, the resistance and resistivity of COF-6 decrease, showing the electrical properties of semiconductor materials. The thermal decomposition temperature of the material is 357.8°C, indicating that it has good thermal stability.
[0050] Example 8 Weigh (50.8 mg, 0.06 mmol), (30.8 mg, 0.19 mmol) and tetrabutylammonium bromide (8.3 mg, 0.03 mmol) were added to a reaction tube, and 10 mL of sodium tert-butoxide aqueous solution (480.6 mg, 0.3 mmol) was prepared. 2 mL of sodium tert-butoxide aqueous solution was added to the tube, followed by 6 mL of dioxane and sonication to form a uniform dispersion. Pd(dba)2 palladium (4.1 mg, 0.004 mmol) was then quickly added to the mixed solution. The reaction tube was sealed and frozen, vacuumed, and thawed with liquid nitrogen. The mixed solution was stirred in an oil bath at 150°C for 120 hours. The reaction was shut down and allowed to cool to room temperature. The solution was then filtered and the filtered solid was washed with methanol and acetone in a Soxhlet extractor to remove unreacted starting materials. The resulting solid was dried for 24 hours to obtain the target product, numbered COF-8, with the structure shown below:
[0051] The PXRD curve of the covalent organic framework material COF-8 prepared in this embodiment is 2 θ =1.9°, indicating that the material is highly crystalline. The thermal decomposition temperature of the material is 435.2°C, indicating that it has good thermal stability. The fully conjugated organic framework material is used as the light-emitting layer in the OLED device. The electroluminescence performance test shows that its turn-on voltage is 6V and the brightness is 55 cd / m 2 .
[0052] Example 9 Weigh (52.2 mg, 0.11 mmol), (54.2 mg, 0.33 mmol) and tetrabutylammonium bromide (10.8 mg, 0.03 mmol) were added to a reaction tube, and 10 mL of Na2CO3 aqueous solution (529.95 mg, 0.3 mmol) was prepared. 2 mL of Na2CO3 aqueous solution was added to the tube, and 6 mL of trimethylbenzene was added and sonicated to form a uniform dispersion. Pd(PPh3)4 (5.3 mg, 0.005 mmol) was then quickly added to the mixed solution. The reaction tube was sealed and frozen-vacuumed-thawed with liquid nitrogen. The mixed solution was stirred in an oil bath at 100°C for 24 hours. The reaction was shut down and allowed to cool to room temperature. It was then filtered and the filtered solid was washed with tetrahydrofuran and acetone in a Soxhlet extractor to remove unreacted starting materials. The resulting solid was dried for 24 hours to obtain the target product, numbered COF-1, with the structure shown below:
[0053] The temperature-resistance curve of the covalent organic framework material prepared in this embodiment shows that as the temperature rises, the resistance and resistivity of COF-1 decrease, showing the electrical properties of semiconductor materials; the PXRD curve of the material is 2 θ =2.1°, indicating that the material is highly crystalline. The thermal decomposition temperature of the material is 348.9°C, indicating that it has good thermal stability.
[0054] Example 10 Weigh (50.6 mg, 0.11 mmol), (81.3 mg, 0.34 mmol) and tetrabutylammonium bromide (13.3 mg, 0.04 mmol) were added to a reaction tube, and 10 mL of KOH aqueous solution (168.1 mg, 0.3 mmol) was prepared. 2 mL of KOH aqueous solution was added to the tube, followed by 6 mL of dioxane and sonication to form a uniform dispersion. PdCl2(PPh3)2 (6.6 mg, 0.006 mmol) was then quickly added to the mixed solution. The reaction tube was sealed and frozen, vacuumed, and thawed with liquid nitrogen. The mixed solution was stirred in an oil bath at 80°C for 36 hours. The reaction was shut down and allowed to cool to room temperature. It was then filtered and the filtered solid was washed with ethanol and acetone in a Soxhlet extractor to remove unreacted starting materials. The resulting solid was dried for 24 hours to obtain the target product with a yield of 57%. It is numbered COF-2 and its structure is shown below:
[0055] The UV-visible absorption spectrum and photoluminescence spectrum of the covalent organic framework material prepared in this embodiment show that COF-2 has an absorption peak at 365 nm and a strong emission peak at around 440 nm; the PXRD curve of the material is 2 θ =1.9°, indicating that the material is highly crystalline. The thermal decomposition temperature of the material is 428.6°C, indicating that it has good thermal stability. The temperature-resistance curve of the fully conjugated organic framework material shows that as the temperature rises, the resistance and resistivity of COF-2 decrease, showing the electrical properties of semiconductor materials.
[0056] Finally, it should be noted that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any form. Any non-innovative changes and modifications made to the technical solution of the present invention using the above description, without departing from the scope of the technical solution of the present invention, such as changes to the ratio of raw material and reagent addition, reaction time, and operating procedures, shall be included within the scope of protection of the present invention.
Claims
1. A fully conjugated covalent organic framework material, characterized in that: The fully conjugated organic framework material is a fully conjugated two-dimensional organic crystalline polymer constructed by monomer A with an Ar1 structure and monomer B with an Ar2 structure through carbon-carbon bonds; Monomer A is one of the following three structures: a C3 symmetric unit with 3 reaction sites, a C2 symmetric unit with 4 reaction sites, and a C3 symmetric unit with 6 reaction sites; Monomer B is a linear C2 symmetric unit with 2 reaction sites; wherein C2, C3, and C4 represent symmetrical building blocks; The reaction site is a functional group in the building block that participates in forming a covalent bond. The functional group of monomer A and the functional group of monomer B form a covalent bond through a carbon-carbon coupling reaction.
2. The fully conjugated covalent organic framework material according to claim 1, characterized in that The functional groups in monomer A are , the functional group in monomer B is ; Or, the functional group in monomer A is , the functional group in monomer B is .
3. The fully conjugated covalent organic framework material according to claim 1, characterized in that Ar1 is selected from one of the following structures: 。 4. The fully conjugated covalent organic framework material according to claim 1, characterized in that Ar1 is selected from one of the following structures: 。 5. The fully conjugated covalent organic framework material according to claim 1, characterized in that Ar1 is selected from one of the following structures: 。 6. The fully conjugated covalent organic framework material according to claim 1, characterized in that Ar2 is selected from one of the following structures: 。 7. The fully conjugated covalent organic framework material according to claim 1, characterized in that The fully conjugated covalent organic framework material is one of the following structures: ； ； ； ； 。 8. The method for preparing the fully conjugated covalent organic framework material according to claim 1, characterized in that: The steps include: Monomer A, monomer B and a catalyst are added to a reaction tube, and then an organic solvent and an alkaline aqueous solution are added to form a mixed solution, and the mixed solution is ultrasonically treated to form a dispersion; the reaction tube is subjected to liquid nitrogen freezing, vacuuming, and thawing cycle degassing treatment, and the reaction is carried out at 20-200°C for 1-30 days. After the reaction is completed, the reactants are filtered and collected, and then washed and dried to obtain a fully conjugated covalent organic framework material.
9. The preparation method according to claim 8, characterized in that The organic solvent is one of toluene, dioxane, trimethylbenzene, dimethyl sulfoxide, dimethylformamide, and tetrahydrofuran; The alkaline substance in the alkaline aqueous solution is one of sodium carbonate, potassium carbonate, cesium carbonate, potassium phosphate, potassium tert-butoxide, sodium tert-butoxide, sodium hydroxide, and potassium hydroxide; The catalyst is one of Pd(PPh3)4, Pd(OAc)2, Pd(dba)2, PdCl2(dppf), and PdCl2(PPh3)2; The solvent used for washing is one or more of methanol, ethanol, tetrahydrofuran, dichloromethane, acetone and water.
10. The use of the fully conjugated covalent organic framework material according to claim 1, characterized in that: The fully conjugated covalent organic framework material is used for optoelectronic devices, adsorption, catalysis, sensors, energy storage and conversion, gas storage and separation, and nanofiltration materials.