Acylhydrazone-linked covalent organic framework material as well as preparation method and application thereof

Abstract

The invention discloses an acylhydrazone-linked covalent organic framework material as well as a preparation method and application thereof, and belongs to the technical field of synthesis of covalent organic framework materials. The preparation method of the acylhydrazone-linked covalent organic framework material comprises the following steps: mixing benzo [1, 2-b: 3, 4-b ': 5, 6-b ''] trithiophene-2, 5, 8-tricarboxaldehyde, benzene dihydrazide, o-dichlorobenzene and n-butyl alcohol to obtain a suspension A; adding trifluoroacetic acid into the suspension A, and mixing to obtain a mixture A; sequentially carrying out freezing degassing and heating treatment on the mixture A, and then extracting to obtain a final product. According to the invention, benzo [1, 2-b: 3, 4-b ': 5, 6-b ''] trithiophene-2, 5, 8-tricarboxaldehyde and benzene dihydrazide with a specific structure are taken as main raw materials, and the acylhydrazone connected covalent organic framework material with higher crystallinity and stability is prepared by adjusting the concentration, variety and dosage of a catalyst.

Description

Technical Field

[0001] The invention belongs to the technical field of covalent organic framework material synthesis, and more specifically relates to an acylhydrazone-linked covalent organic framework material and a preparation method and application thereof. Background Art

[0002] With the continuous development of materials science, people have a growing demand for new materials with specific properties and structures. Traditional inorganic porous materials and organic-inorganic hybrid materials have limitations in some aspects, such as high density, poor structural designability, and complex synthesis process. In 2005, Yaghi's research group first reported the synthesis of covalent organic framework materials (COFs) with crystalline structures through boric acid dehydration polycondensation reaction, opening a new era of COFs material research.

[0003] Although there are many methods for synthesizing acylhydrazone-linked COFs materials, there are still some problems, such as the low crystallinity and stability of the prepared acylhydrazone-linked covalent organic framework materials. Therefore, it is necessary to further explore and develop the synthesis methods of acylhydrazone-linked covalent organic framework materials with higher crystallinity and stability to achieve large-scale preparation and application. Summary of the invention

[0004] The purpose of the present invention is to provide an acylhydrazone-linked covalent organic framework material and a preparation method and application thereof, so as to solve the problems existing in the above-mentioned prior art and realize the preparation and application of an acylhydrazone-linked covalent organic framework material with higher crystallinity and stability.

[0005] To achieve the above object, the present invention provides the following solutions:

[0006] One of the technical solutions of the present invention is to provide a covalent organic framework material connected by acylhydrazone, wherein the structural unit of the covalent organic framework material connected by acylhydrazone is:

[0007] Wherein, “﹉” represents an omitted structural repeating unit, and R is selected from -OCH2CH3 or -OCH2CHCH2.

[0008] The second technical solution of the present invention is to provide a method for preparing the acylhydrazone-linked covalent organic framework material, comprising the following steps:

[0009] Mix benzo[1,2-b:3,4-b':5,6-b"]terthiophene-2,5,8-tricarbaldehyde, phthaloylhydrazide, o-dichlorobenzene (o-DCB) and n-butanol to obtain a suspension A;

[0010] Add trifluoroacetic acid (TFA) to the suspension A and mix to obtain a mixture A;

[0011] The mixture A is sequentially subjected to freeze degassing and heating treatments, and then extracted to obtain the acylhydrazone-linked covalent organic framework material.

[0012] The present invention uses benzo[1,2-b:3,4-b':5,6-b"]trithiophene-2,5,8-tricarbaldehyde and phthaloylhydrazide of a specific structure as main raw materials, and adjusts the concentration and dosage of trifluoroacetic acid to prepare an acylhydrazone-connected covalent organic framework material with higher crystallinity and stability. Since the acylhydrazone-connected covalent organic framework material prepared by the present invention contains an acylhydrazone bond, it is ensured that it has higher crystallinity and stability, and higher crystallinity and stability can ensure that the acylhydrazone-connected covalent organic framework material has excellent adsorption effect, separation effect and stability.

[0013] Preferably, the usage ratio of benzo[1,2-b:3,4-b':5,6-b"]terthiophene-2,5,8-tricarbaldehyde, phthaloylhydrazide and o-dichlorobenzene is 0.075-0.085 mmol:0.11-0.14 mmol:1.5 mL.

[0014] Preferably, the volume ratio of o-dichlorobenzene to n-butanol is 1:1.

[0015] The appropriate solubility of the reactants can be ensured by adjusting the volume ratio of o-dichlorobenzene and n-butanol. A volume ratio higher than the upper limit of the range will result in a decrease in crystallinity, while a volume ratio lower than the lower limit of the range will result in a decrease in polymerization degree.

[0016] Preferably, the trifluoroacetic acid is added in the form of a trifluoroacetic acid aqueous solution; the concentration of the trifluoroacetic acid aqueous solution is 3-4 M; the volume ratio of the trifluoroacetic acid aqueous solution to o-dichlorobenzene is 30-40 μL:1.5 mL.

[0017] The solubility and reaction activity of the reaction product can be improved by adjusting the concentration of the catalyst trifluoroacetic acid and the amount of trifluoroacetic acid added. A concentration higher than the upper limit of the range will result in the destruction of crystallinity, and a concentration lower than the lower limit of the range will result in a decrease in the degree of polymerization.

[0018] Preferably, the structural formula of the phthaloylhydrazide is:

[0019] Wherein, R is selected from -OCH2CH3 or -OCH2CHCH2.

[0020] The smooth preparation of acylhydrazone-linked covalent organic framework materials can be ensured by selecting a phthaloylhydrazine with a specific structure. The present invention combines benzo[1,2-b:3,4-b':5,6-b"]terthiophene-2,5,8-tricarbaldehyde with a phthaloylhydrazine with a specific structure, and can improve the stability of the framework structure through the electronic action of the side chains, thereby preparing an acylhydrazone-linked covalent organic framework material with higher crystallinity and stability.

[0021] Preferably, the number of freeze degassing is 2 to 5 times.

[0022] Preferably, the heating treatment is carried out at a temperature of 120 to 180° C. and for a time of 3 to 5 days.

[0023] Preferably, the reagents used for the extraction include tetrahydrofuran and N,N-dimethylformamide; and the extraction time is 48 to 72 hours.

[0024] The third technical solution of the present invention is to provide the application of the acylhydrazone-linked covalent organic framework material in the field of electrochemical energy storage.

[0025] The present invention discloses the following technical effects:

[0026] 1. The present invention uses benzo[1,2-b:3,4-b':5,6-b"]terthiophene-2,5,8-tricarbaldehyde and phthaloylhydrazide of a specific structure as main raw materials, and prepares a covalent organic framework material connected by acylhydrazone with higher crystallinity and stability by adjusting the concentration, type and dosage of the catalyst.

[0027] 2. The present invention has low synthesis requirements, simple preparation process, and the raw materials used are simple and easy to obtain, and has better application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 The schematic diagram of the synthesis of the acylhydrazone-linked covalent organic framework material of the present invention;

[0029] Figure 2 The schematic diagram of the synthesis of the acylhydrazone-linked covalent organic framework material described in Example 1;

[0030] Figure 3 The schematic diagram of the synthesis of the acylhydrazone-linked covalent organic framework material described in Example 2;

[0031] Figure 4 The schematic diagram of the synthesis of the acylhydrazone-linked covalent organic framework material described in Example 3;

[0032] Figure 5 The XRD pattern of the non-characteristic peak of the acylhydrazone-linked covalent organic framework material No. 1 described in Example 1;

[0033] Figure 6 The weak characteristic peak XRD pattern of the covalent organic framework material connected by acylhydrazone with serial number 3 described in Example 1;

[0034] Figure 7 The XRD pattern of the strongly characteristic peak of the covalent organic framework material connected by acylhydrazone with serial number 9 described in Example 1;

[0035] Figure 8 The XRD pattern of the non-characteristic peak of the acylhydrazone-linked covalent organic framework material No. 1 described in Example 2;

[0036] Fig. 9 The weak characteristic peak XRD pattern of the acylhydrazone-linked covalent organic framework material with serial number 3 described in Example 2;

[0037] Fig.10 The XRD pattern of the strongly characteristic peak of the acylhydrazone-linked covalent organic framework material No. 9 described in Example 2;

[0038] Fig.11 The XRD pattern of the non-characteristic peak of the acylhydrazone-linked covalent organic framework material No. 6 described in Example 3;

[0039] Fig.12 The stability test XRD pattern of the acylhydrazone-linked covalent organic framework material No. 6 described in Example 1;

[0040] Fig.13 This is the XRD diagram of the stability test of the acylhydrazone-linked covalent organic framework material No. 6 described in Example 2. DETAILED DESCRIPTION

[0041] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as limiting the present invention, but should be understood as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0042] It should be understood that the terms described in the present invention are only for describing a particular embodiment and are not intended to limit the present invention. In addition, for the numerical range in the present invention, it should be understood that each intermediate value between the upper and lower limits of the scope is also specifically disclosed. The intermediate value in any stated value or stated range, and each smaller range between any other stated value or intermediate value in the described range is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded in the scope.

[0043] Unless otherwise indicated, all technical and scientific terms used herein have the same meanings as those generally understood by those skilled in the art. Although the present invention describes only preferred methods and materials, any methods and materials similar or equivalent to those described herein may also be used in the implementation or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials associated with the documents. In the event of a conflict with any incorporated document, the content of this specification shall prevail.

[0044] It will be apparent to those skilled in the art that various modifications and variations may be made to the specific embodiments of the present invention description without departing from the scope or spirit of the present invention. Other embodiments derived from the present invention description will be apparent to those skilled in the art. The present invention description and examples are exemplary only.

[0045] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0046] The raw materials used in the embodiments of the present invention are described below:

[0047] The benzo[1,2-b:3,4-b':5,6-b"]terthiophene-2,5,8-tricarbaldehyde used was purchased from Bidex Pharmaceuticals.

[0048] The 2,5-diethoxybenzene-1,4-dicarboxylic acid hydrazide used was synthesized in the laboratory.

[0049] The 1,4-diformylhydrazide used was purchased from Adamas.

[0050] The 2,5-bis(allyloxy)terephthaloylhydrazide used was purchased from Bitart Pharmaceuticals.

[0051] The o-dichlorobenzene (o-DCB) used was purchased from Adamas.

[0052] The n-butanol used was purchased from Adamas.

[0053] The trifluoroacetic acid (TFA) used was purchased from Adamas.

[0054] Acetic acid (AcOH) used was purchased from Adamas.

[0055] Other raw materials are commercially available unless otherwise specified.

[0056] The present invention provides a covalent organic framework material connected by acylhydrazone with higher crystallinity and stability. The specific synthesis process is as follows: Figure 1 As shown, the problem in the prior art that covalent organic framework materials are difficult to crystallize and have poor ability to form self-repairing covalent bonds is solved. There are still many difficulties in obtaining covalent organic framework materials with high crystallinity and stable pore structure. The problem that the existing covalent organic framework materials have low stability and are not conducive to later applications is also solved.

[0057] Example 1

[0058] This example verifies that when R in phthaloylhydrazide is selected from -OCH2CH3, a covalent organic framework material connected by acylhydrazone is prepared based on different catalyst types, dosages and concentrations and different heating reaction times, as follows:

[0059] Preparation steps:

[0060] Benzo[1,2-b:3,4-b':5,6-b"]trithiophene-2,5,8-tricarbaldehyde (26.4 mg) and benzodiazepine (33.8 mg) wherein R is selected from -OCH2CH3 are dissolved in o-dichlorobenzene (o-DCB) (1.5 mL), and n-butanol (1.5 mL) is added to obtain a suspension; a catalyst (including acetic acid (AcOH) or trifluoroacetic acid (TFA), both added in the form of an aqueous solution) is then added to the suspension and shaken for 5 min; the sample is subjected to Freeze degassing 3 times; heating at 120°C; after the reaction, cool the sample to room temperature, filter the precipitate, wash it 3 times with acetone (10 mL) and tetrahydrofuran (10 mL) respectively until the eluent is clear, and perform Soxhlet extraction on the obtained solid in a mixed solvent of tetrahydrofuran and N,N-dimethylformamide (the volume ratio of tetrahydrofuran to N,N-dimethylformamide is 1:1) for 72 h, and vacuum dry to obtain a yellow powder, which is an acylhydrazone-linked covalent organic framework material, denoted as BTT-TH-COF.

[0061] The catalyst type, dosage, concentration and heating reaction time corresponding to this embodiment are shown in Table 1.

[0062] Table 1

[0063]

[0064] According to the above preparation method combined with the parameters in Table 1, 9 products were prepared.

[0065] Figure 2 Schematic diagram of the synthesis of the acylhydrazone-linked covalent organic framework material described in Example 1.

[0066] Figure 5 The XRD pattern of the non-characteristic peak of the acylhydrazone-linked covalent organic framework material No. 1 described in Example 1; Figure 6 The weak characteristic peak XRD pattern of the covalent organic framework material connected by acylhydrazone with serial number 3 described in Example 1; Figure 7 This is a strong characteristic peak XRD pattern of the acylhydrazone-linked covalent organic framework material with serial number 9 described in Example 1.

[0067] Example 2

[0068] This example verifies that when R in phthaloylhydrazide is selected from -OCH2CHCH2, a covalent organic framework material connected by acylhydrazone is prepared based on different catalyst types, dosages and concentrations and different heating reaction times, as follows:

[0069] Preparation steps:

[0070] Benzo[1,2-b:3,4-b':5,6-b"]trithiophene-2,5,8-tricarbaldehyde (26.4 mg) and benzodiazepine (33.8 mg) wherein R is selected from -OCH2CHCH2 are dissolved in o-dichlorobenzene (o-DCB) (1.5 mL), and n-butanol (1.5 mL) is added to obtain a suspension; a catalyst (including acetic acid (AcOH) or trifluoroacetic acid (TFA), both added in the form of an aqueous solution) is then added to the suspension and shaken for 5 min; the sample is subjected to The reaction mixture was freeze-degassed for 3 times and heated at 120°C. After the reaction, the sample was cooled to room temperature, the precipitate was filtered, and washed 3 times with acetone (10 mL) and tetrahydrofuran (10 mL) respectively until the eluent was clear. The obtained solid was subjected to Soxhlet extraction in a mixed solvent of tetrahydrofuran and N,N-dimethylformamide (the volume ratio of tetrahydrofuran to N,N-dimethylformamide was 1:1) for 72 h, and vacuum dried to obtain a yellow powder, which was an acylhydrazone-linked covalent organic framework material, denoted as BTT-TH-COF.

[0071] The catalyst type, dosage, concentration and heating reaction time corresponding to this embodiment are shown in Table 2.

[0072] Table 2

[0073]

[0074]

[0075] According to the above preparation method combined with the parameters in Table 1, 9 products were prepared.

[0076] Figure 3 Schematic diagram of the synthesis of the acylhydrazone-linked covalent organic framework material described in Example 2.

[0077] Figure 8 The XRD pattern of the non-characteristic peak of the acylhydrazone-linked covalent organic framework material No. 1 described in Example 2; Fig. 9 The weak characteristic peak XRD pattern of the acylhydrazone-linked covalent organic framework material with serial number 3 described in Example 2; Fig.10 The XRD pattern of the strongly characteristic peak of the acylhydrazone-linked covalent organic framework material No. 9 described in Example 2;

[0078] Example 3

[0079] This example verifies that when R in phthaloylhydrazide is selected from -H, a covalent organic framework material connected by acylhydrazone is prepared based on different catalyst types, dosages and concentrations and different heating reaction times, as follows:

[0080] Preparation steps:

[0081] Benzo[1,2-b:3,4-b':5,6-b"]trithiophene-2,5,8-tricarbaldehyde (26.4 mg) and phthaloylhydrazide (33.8 mg) wherein R is selected from -H are dissolved in o-dichlorobenzene (o-DCB) (1.5 mL), and n-butanol (1.5 mL) is added to obtain a suspension; a catalyst (including acetic acid (AcOH) or trifluoroacetic acid (TFA), both added in the form of an aqueous solution) is then added to the suspension and shaken for 5 min; the sample is subjected to cryo-desorption. The reaction mixture was degassed three times; heated at 120°C; after the reaction, the sample was cooled to room temperature, the precipitate was filtered, and washed three times with acetone (10 mL) and tetrahydrofuran (10 mL) respectively until the eluent was clear. The obtained solid was subjected to Soxhlet extraction in a mixed solvent of tetrahydrofuran and N,N-dimethylformamide (the volume ratio of tetrahydrofuran to N,N-dimethylformamide was 1:1) for 72 h, and vacuum dried to obtain a yellow powder, which was an acylhydrazone-linked covalent organic framework material, denoted as BTT-TH-COF.

[0082] The catalyst type, dosage, concentration and heating reaction time corresponding to this embodiment are shown in Table 3.

[0083] Table 3

[0084]

[0085] According to the above preparation method combined with the parameters in Table 1, 9 products were prepared.

[0086] Figure 4 Schematic diagram of the synthesis of the acylhydrazone-linked covalent organic framework material described in Example 3.

[0087] Fig.11 This is the XRD pattern without characteristic peaks of the acylhydrazone-linked covalent organic framework material No. 6 described in Example 3.

[0088] Performance Verification:

[0089] The crystallinity and stability of the 27 products obtained in Examples 1 to 3 were verified:

[0090] Crystallinity: The crystallinity of the obtained product is related to the strength of the XRD small-angle diffraction peak. As shown in Tables 1 to 3, when R in phthaloyl hydrazide is selected from -H, the obtained product has no crystallinity. However, the product prepared by the present invention has excellent crystallinity.

[0091] Stability: The stability of the product No. 6 obtained in Example 1 and the product No. 6 obtained in Example 2 under different reagents was measured. The results are as follows: Fig.12 and Fig.13 shown.

[0092] Fig.12The stability test XRD pattern of the acylhydrazone-linked covalent organic framework material No. 6 described in Example 1; Fig.13 This is the stability test XRD diagram of the covalent organic framework material connected by acylhydrazone No. 6 described in Example 2. Figure 12-13 It can be seen that the acylhydrazone-linked covalent organic framework material No. 6 described in Example 1 and the acylhydrazone-linked covalent organic framework material No. 6 described in Example 2 both have excellent stability. Since the acylhydrazone-linked covalent organic framework materials synthesized in Example 3 have no crystallinity, the stability is not discussed.

[0093] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0094] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An acylhydrazone-linked covalent organic framework material, characterized in that: The structural unit of the covalent organic framework material connected by the acylhydrazone is: Wherein, "﹉" represents an omitted structural repeating unit, and R is selected from -OCH2CH3 or -OCH2CHCH2.

2. The method for preparing the acylhydrazone-linked covalent organic framework material according to claim 1, characterized in that: The steps include: Mix benzo[1,2-b:3,4-b':5,6-b"]terthiophene-2,5,8-tricarbaldehyde, phthaloylhydrazide, o-dichlorobenzene and n-butanol to obtain a suspension A; Add trifluoroacetic acid to the suspension A and mix to obtain a mixture A; The mixture A is sequentially subjected to freeze degassing and heating treatments, and then extracted to obtain the acylhydrazone-linked covalent organic framework material.

3. The preparation method according to claim 2, characterized in that: The usage ratio of the benzo[1,2-b:3,4-b':5,6-b"]terthiophene-2,5,8-tricarbaldehyde, phthaloylhydrazide and o-dichlorobenzene is 0.075-0.085 mmol:0.11-0.14 mmol:1.5 mL.

4. The preparation method according to claim 2, characterized in that: The volume ratio of o-dichlorobenzene to n-butanol is 1:

1.

5. The preparation method according to claim 2, characterized in that: The trifluoroacetic acid is added in the form of a trifluoroacetic acid aqueous solution; the concentration of the trifluoroacetic acid aqueous solution is 3-4M; the volume ratio of the trifluoroacetic acid aqueous solution to o-dichlorobenzene is 30-40 μL:1.5 mL.

6. The preparation method according to claim 2, characterized in that: The structural formula of the phthaloylhydrazide is: Wherein, R is selected from -OCH2CH3 or -OCH2CHCH2.

7. The preparation method according to claim 2, characterized in that: The number of freeze degassing is 2 to 5 times.

8. The preparation method according to claim 2, characterized in that: The temperature of the heating treatment is 120-180° C., and the time is 3-5 days.

9. The preparation method according to claim 2, characterized in that: The reagents used for the extraction include tetrahydrofuran and N,N-dimethylformamide; the extraction time is 48 to 72 hours.

10. Use of the acylhydrazone-linked covalent organic framework material according to claim 1 in the field of electrochemical energy storage.

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