Strong conjugation covalent organic framework material based on tetrathiophene-anthracene unit as well as preparation method and application of strong conjugation covalent organic framework material

Abstract

The invention discloses a strongly conjugated covalent organic framework material based on a tetrathiophene-anthracene unit as well as a preparation method and application thereof. The preparation method comprises the following steps: S1, reacting and purifying a composition containing 1, 2, 4, 5-tetrabromobenzene for multiple times to prepare ATT; s2, ATT, a pairing reagent and a 6M acetic acid aqueous solution are dissolved in a first solvent for a reaction; when the pairing reagent is TFPPy, COF-ATT is prepared; when the COF-ATTA is TAEPy, COF-ATTA is prepared. Synthesis of two novel COFs with different conjugation degrees is designed based on a tetrathiophene-anthracene structural unit as a raw material, and the two COFs are high in structural rigidity and conjugation degree, have a promoting effect on charge transfer and can improve the conjugation strength of an overall frame structure, so that the light absorption capacity is improved, and rapid transfer of carriers along a molecular skeleton is promoted.

Description

Technical Field

[0001] The present invention relates to the technical field of the synthesis and application of novel covalent organic framework materials (COFs), and particularly to a strongly conjugated covalent organic framework material based on a tetrathiophene-anthracene unit, a preparation method thereof, and an application. Background Art

[0002] Covalent organic framework (COF) materials are novel ordered porous materials connected by covalent bonds constructed through reversible reactions of organic linkers by light elements such as C, H, O, N, and S in a thermodynamically stable state, and their structural units are connected by covalent bonds. In recent years, with the in-depth research, COFs have good application prospects in gas adsorption, molecular separation, drug delivery, catalysis, energy storage and conversion, etc. From the perspective of photocatalysis, the periodic and ordered stacked structure endows it with high crystallinity and high specific surface area, and the one-dimensional pore channels with uniform pore size facilitate the separation and transmission of carriers.

[0003] At present, the most studied pyrene-based π-conjugated structure exhibits excellent optoelectronic activity in the COFs constructed therefrom due to its strong conjugation. However, the photocatalytic performance of pyrene-based π-conjugated COFs is far from reaching the theoretical value and the standard of practical application, and there is a large room for design and improvement. It is found that an expandable π-conjugated structure will broaden the light absorption range, and aggregation state interactions such as π-π stacking can generate more photo-generated carriers, resulting in delocalization of carriers over a larger range and forming channels for the transport and dissociation of excitons, which has great application potential in the field of photocatalysis. Research reports show that the electron cloud arrangement of thiophene is denser than that of the benzene ring, and the natural conjugation is also stronger than that of the benzene ring, and the introduction of S heteroatoms will significantly improve the power supply property. Therefore, it is proposed to introduce a thiophene structure into the benzene ring system to improve the conjugation of the overall molecular structure.

[0004] For example, in Patent Application No. 202110012977.5, a COF material constructed with anthracene as the unit core and a preparation method thereof are proposed. The preparation method includes the following steps: specifically, 2,6-anthracenediamine, tris(4-formylphenyl)amine, a solvent, and a catalyst are placed in a sealed tube, then the sealed tube is deoxygenated, and then polycondensation reaction is carried out at 120-150 °C under the protection of an inert gas or nitrogen for 1-7 days. Finally, the product is eluted and purified with an eluent, and the product is obtained after drying. The anthracene structure mainly used in this patent has weak conjugation / conductivity and poor activity in the catalytic field.

[0005] In view of this, improvements should be made to the existing technology. Summary of the Invention

[0006] The main object of the present invention is to provide a strongly conjugated covalent organic framework material based on a tetrathiophene-anthracene unit, a preparation method thereof, and an application. Two novel COFs with different degrees of conjugation are designed using a tetrathiophene-anthracene structural unit as a raw material. These two COFs have strong structural rigidity and high degrees of conjugation, which promote charge transport, enhance the conjugation strength of the overall framework structure, thereby improving the light absorption ability and facilitating the rapid transfer of carriers along the molecular backbone.

[0007] According to one aspect of the present invention, there is provided a strongly conjugated covalent organic framework material based on a tetrathiophene-anthracene unit, the structural formula of which is shown as COF-ATT or COF-ATTA: COF-ATT: ; COF-ATTA: .

[0008] According to another aspect of the present invention, there is provided a preparation method of a strongly conjugated covalent organic framework material based on the above technical solution, which includes the following steps: S1. React a composition containing 1,2,4,5-tetrabromobenzene under an inert gas condition and purify by column chromatography to obtain 2,2′,2′′,2′′-(1,2,4,5-benzenetetrayl)tetrathiophene; React a composition containing the obtained 2,2′,2′′,2′′-(1,2,4,5-benzenetetrayl)tetrathiophene under an inert gas condition to obtain 2,2′,2′′,2′′-(1,2,4,5-benzenetetrayl)tetrakis[5-bromothiophene]; React a composition containing the obtained 2,2′,2′′,2′′-(1,2,4,5-benzenetetrayl)tetrakis[5-bromothiophene] under an inert gas condition and purify to obtain 2,5,9,12-tetrabromoanthra[1,2-b:4,3-b′:5,6-b′′:8,7-b′′]tetrathiophene; React a composition containing the obtained 2,5,9,12-tetrabromoanthra[1,2-b:4,3-b′:5,6-b′′:8,7-b′′]tetrathiophene under an inert gas condition and purify by pickling to obtain ATT; Wherein, ATT is 4,4',4'',4'''-(anthra[1,2-b:4,3-b':5,6-b'':8,7-b'']tetrathiophene-2,5,9,12-tetrayl)tetrabenzaldehyde, and its structural formula is: ; S2. Dissolve the ATT obtained in step S1, a pairing reagent, and 6M aqueous acetic acid solution in a first solvent and react under an inert gas condition; Among them, when the pairing reagent is TFPPy, COF-ATT is prepared; When the pairing reagent is TAEPy, COF-ATTA is prepared.

[0009] According to an embodiment of the present invention, step S1 specifically includes: S11. Add 1,2,4,5-tetrabromobenzene, bis(triphenylphosphine)palladium(II) chloride, and 2-(tributylstannyl)thiophene into a second solvent, react under an inert gas condition, and purify the crude product by column chromatography to obtain 2,2′,2′′,2′′-(1,2,4,5-benzenetetrayl)tetrathiophene; S12. Add the 2,2′,2′′,2′′-(1,2,4,5-benzenetetrayl)tetrathiophene obtained in step S11 and N-bromosuccinimide into a third solvent, react under an inert gas condition to obtain 2,2′,2′′,2′′-(1,2,4,5-benzenetetrayl)tetra[5-bromothiophene]; S13. Add the 2,2′,2′′,2′′-(1,2,4,5-benzenetetrayl)tetra[5-bromothiophene] obtained in step S12 and iron(III) chloride into a fourth solvent, react under an inert gas condition and purify to obtain 2,5,9,12-tetrabromoanthra[1,2-b:4,3-b′:5,6-b′′:8,7-b′′]tetrathiophene; S14. Add the 2,5,9,12-tetrabromoanthra[1,2-b:4,3-b′:5,6-b′′:8,7-b′′]tetrathiophene obtained in step S13, 4-formylphenylboronic acid, tetrakis(triphenylphosphine)palladium, and potassium carbonate into a fifth solvent, react under an inert gas condition, and purify by acid washing to obtain 4,4',4'',4'''-(anthra[1,2-b:4,3-b':5,6-b'':8,7-b'']tetrathiophene-2,5,9,12-tetrayl)tetrabenzaldehyde.

[0010] According to an embodiment of the present invention, the first solvent includes one or more of mesitylene, dioxane, n-butanol, and absolute ethanol.

[0011] According to an embodiment of the present invention, the second solvent includes N,N-dimethylformamide; the third solvent includes tetrahydrofuran; the fourth solvent includes a mixed solution of chlorobenzene and nitromethane; the fifth solvent includes tetrahydrofuran.

[0012] According to an embodiment of the present invention, in step S2, the reaction under an inert gas condition specifically includes reacting at 115~125 °C for 71~73 h.

[0013] According to an embodiment of the present invention, it further includes: In step S11, the reaction under inert gas conditions specifically includes reacting at 110-130 °C for 15-20 h; In step S12, the reaction under inert gas conditions specifically includes reacting at 20-35 °C for 10-20 h; In step S13, the reaction under inert gas conditions specifically includes reacting at 20-35 °C for 40-80 min; In step S14, the reaction under inert gas conditions specifically includes reacting at room temperature for 2-5 days.

[0014] According to an embodiment of the present invention, in step S2, the addition amounts of the components are as follows: ATT: 0.03-0.05 mmol, TFPPy: 0.03-0.05 mmol, 6M aqueous acetic acid solution: 0.11-0.13 mL; in step S3, the addition amounts of the components are as follows: ATT: 0.03-0.05 mmol, TAEPy: 0.03-0.05 mmol, 6M aqueous acetic acid solution: 0.11-0.13 mL.

[0015] According to an embodiment of the present invention, it further includes: In step S11, the addition amounts of the components are as follows: 1,2,4,5-tetrabromobenzene: 9-11 mmol, bis(triphenylphosphine)palladium(II) chloride: 0.5-1.5 mmol, 2-(tributylstannyl)thiophene: 42-65 mmol; In step S12, the addition amounts of the components are as follows: 2,2′,2′′,2′′-(1,2,4,5-benzenetetrayl)tetrathiophene: 4.5-5 mmol, N-bromosuccinimide: 25-35 mmol; In step S13, the addition amounts of the components are as follows: 2,2′,2′′,2′′-(1,2,4,5-benzenetetrayl)tetrakis[5-bromothiophene]: 1.1-1.5 mmol, iron(III) chloride: 8-10 mmol; In step S14, the addition amounts of the components are as follows: 2,5,9,12-tetrabromoanthra[1,2-b:4,3-b′:5,6-b′′:8,7-b′′]tetrathiophene: 1.5-2.0 mmol, 4-formylphenylboronic acid: 10-12 mmol, tetrakis(triphenylphosphine)palladium: 0.05-0.1 mmol, potassium carbonate: 12-16 mmol.

[0016] According to another aspect of the present invention, there is provided an application of a strongly conjugated covalent organic framework material based on a tetrathiophene-anthracene unit, including: using the strongly conjugated covalent organic framework material based on a tetrathiophene-anthracene unit as a catalyst to photocatalytically reduce O2 to produce H2O2 in a water-ethanol mixed system.

[0017] In the strong conjugated covalent organic framework material based on tetrathiophene-anthracene unit, its preparation method and application according to the embodiments of the present invention, two novel COFs with different conjugation degrees are designed using the tetrathiophene-anthracene structural unit as the raw material. These two COFs have strong structural rigidity and high conjugation degree, which can promote charge transport, enhance the conjugation strength of the overall framework structure, thereby improving the light absorption ability and promoting the rapid transfer of carriers along the molecular backbone. Description of the Drawings

[0018] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0019] Figure 1 Shows a process flow chart of a preparation method of a strong conjugated covalent organic framework material based on tetrathiophene-anthracene unit according to an exemplary embodiment of the present invention; Figure 2 Shows the XRD patterns of COF-ATT and COF-ATTA according to the present invention, where (a) is the XRD pattern of COF-ATT and (b) is the XRD pattern of COF-ATTA; Figure 3 Shows the curve graphs of the change of H2O2 parameters with time under the action of light for COF-ATT and COF-ATTA materials according to the present invention. Among them, (a) is the curve graph of the change of H2O2 concentration with time for COF-ATT material under the action of light, and (b) is the curve graph of the change of H2O2 yield with time for COF-ATTA material under the action of light. Detailed Embodiments

[0020] The following detailed description of the embodiments is used to exemplarily illustrate the principles of the present invention, but cannot be used to limit the scope of the present invention. The present invention can be implemented in many different forms, not limited to the specific embodiments disclosed herein, but including all technical solutions falling within the scope of the claims.

[0021] The present invention provides these embodiments to make the present disclosure thorough and complete, and to fully convey the scope of the present invention to those skilled in the art. It should be noted that: unless otherwise specifically stated, the relative arrangements of components and steps, the components of materials, numerical expressions and values described in these embodiments should be interpreted as merely exemplary, rather than as limitations.

[0022] All terms used in this invention have the same meanings as understood by those of ordinary skill in the art to which this disclosure pertains, unless otherwise specifically defined. It should also be understood that terms defined in a general dictionary, such as those, should be interpreted as having a meaning consistent with their meaning in the context of the relevant art, and should not be interpreted in an idealized or overly formal sense, unless specifically defined as such herein.

[0023] Technologies, methods, and devices known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, these technologies, methods, and devices should be regarded as part of the specification.

[0024] Covalent organic framework materials (COF materials) are currently an emerging type of organic crystal material. Their well-defined molecular structure, rich pore structure, relatively stable chemical / thermodynamic stability, and most importantly, the designability of functional structures have long had great potential application value in catalysis, biology, medical treatment, fluorescence, etc. In the field of catalysis, in organic semiconductor materials, the exciton effect results in an exciton binding energy Eab > 300 eV, which greatly limits the rapid separation and transfer of carriers.

[0025] Research shows that the main reason for the good electrical conductivity of graphene is the conjugation of the 2D structure composed of C-C. Therefore, the regulation of conjugation intensity promotes the rapid transport of carriers. In addition, in the COF structure, strong conjugated structures often also have electron-donating properties, and most current organic monomers with strong conjugated structures are based on pyrene and anthracene structures, which greatly limit the development of functional COFs and the development of network topology chemistry. In addition, in organic materials, strong conjugated structures often also bring fluorescence effects, and the COF materials themselves have no harmful effects on organisms. This fluorescence property can be used as a fluorescent label to carry a certain small drug or target marker and implant it into an organism for in-situ, real-time detection, analysis, or treatment of a specific virus.

[0026] This invention provides a strong conjugated covalent organic framework material based on a tetrathiophene-anthracene unit, and its structural formula is shown as COF-ATT or COF-ATTA: COF-ATT:

[0027] COF-ATTA: .

[0028] The smallest repeating unit that makes up these two COF materials is a covalent organic framework, which is synthesized by the Schiff-base reaction of a tetrathiophene-anthracene structural unit and a paired structural unit. This is the first new type of COF raw material constructed with a tetrathiophene-anthracene structure, and two new types of COFs are creatively prepared therefrom.

[0029] In the strong conjugated covalent organic framework material based on the tetrathiophene-anthracene unit, its preparation method and application according to the embodiments of the present invention, the synthesis of two new types of COFs with different conjugation degrees is designed based on the tetrathiophene-anthracene structural unit. These two COFs have strong structural rigidity and high conjugation degree, which promote charge transport, can increase the conjugation strength of the overall framework structure, thereby improving the light absorption ability and promoting the rapid transfer of carriers along the molecular backbone.

[0030] The structural formula of tetrathiophene-anthracene (ATT) is as follows:

[0031] The structural formula of the paired C4 is as follows:

[0032] TFPPyTAEPy The covalent organic frameworks of the two COF materials include: The covalent organic framework based on ATT and TFPPy, namely COF-ATT; The covalent organic framework based on ATT and TAEPy, namely COF-ATTA.

[0033] As Figure 1 shown, the present invention provides a preparation method of a strong conjugated covalent organic framework material based on a tetrathiophene-anthracene unit, which includes the following steps: S1. React a composition containing 1,2,4,5-tetrabromobenzene under inert gas conditions, and purify by column chromatography to obtain 2,2′,2′′,2′′-(1,2,4,5-benzenetetrayl)tetrathiophene; React a composition containing the obtained 2,2′,2′′,2′′-(1,2,4,5-benzenetetrayl)tetrathiophene under inert gas conditions to obtain 2,2′,2′′,2′′-(1,2,4,5-benzenetetrayl)tetrakis[5-bromothiophene]; React a composition containing the obtained 2,2′,2′′,2′′-(1,2,4,5-benzenetetrayl)tetrakis[5-bromothiophene] under inert gas conditions, and purify to obtain 2,5,9,12-tetrabromoanthra[1,2-b:4,3-b′:5,6-b′′:8,7-b′′]tetrathiophene; React a composition containing the prepared 2,5,9,12-tetrabromoanthra[1,2-b:4,3-b′:5,6-b′′:8,7-b′′]tetrathiophene under inert gas conditions, and purify it by pickling to obtain ATT; The specific reaction process is as follows:

[0034] Among them, Compound 1 is 1,2,4,5-tetrabromobenzene, Compound 2 is 2,2′,2′′,2′′-(1,2,4,5-benzenetetrayl)tetrathiophene, Compound 3 is 2,2′,2′′,2′′-(1,2,4,5-benzenetetrayl)tetrakis[5-bromothiophene], Compound 4 is 2,5,9,12-tetrabromoanthra[1,2-b:4,3-b′:5,6-b′′:8,7-b′′]tetrathiophene, and ATT is 4,4',4'',4'''-(anthra[1,2-b:4,3-b':5,6-b'':8,7-b'']tetrathiophene-2,5,9,12-tetrayl)tetrabenzaldehyde; S2. Dissolve the ATT prepared in step S1, the pairing reagent, and 6M aqueous acetic acid solution in the first solvent, and react under inert gas conditions; When the pairing reagent is TFPPy, COF-ATT is obtained; When the pairing reagent is TAEPy, COF-ATTA is obtained.

[0035] In some specific embodiments, step S1 specifically includes: S11. Add 1,2,4,5-tetrabromobenzene, bis(triphenylphosphine)palladium(II) chloride, and 2-(tributylstannyl)thiophene to the second solvent, react under inert gas conditions, and purify the crude product by column chromatography to obtain 2,2′,2′′,2′′-(1,2,4,5-benzenetetrayl)tetrathiophene; S12. Add the 2,2′,2′′,2′′-(1,2,4,5-benzenetetrayl)tetrathiophene prepared in step S11 and N-bromosuccinimide to the third solvent, and react under inert gas conditions to obtain 2,2′,2′′,2′′-(1,2,4,5-benzenetetrayl)tetrakis[5-bromothiophene]; S13. Add the 2,2′,2′′,2′′-(1,2,4,5-benzenetetrayl)tetrakis[5-bromothiophene] prepared in step S12 and iron(III) chloride to the fourth solvent, react under inert gas conditions and purify to obtain 2,5,9,12-tetrabromoanthra[1,2-b:4,3-b′:5,6-b′′:8,7-b′′]tetrathiophene; S14. Add the 2,5,9,12-tetrabromoanthra[1,2-b:4,3-b′:5,6-b′′:8,7-b′′]tetrathiophene prepared in step S13, 4-formylphenylboronic acid, tetrakistriphenylphosphine palladium, and potassium carbonate into a fifth solvent, react under an inert gas condition, and obtain 4,4',4'',4'''-(anthra[1,2-b:4,3-b':5,6-b'':8,7-b'']tetrathiophene-2,5,9,12-tetrayl)tetrabenzaldehyde after pickling and purification. Among them, the inert gas includes argon, nitrogen, and helium.

[0036] The synthesis principle of step S12 follows the bromination reaction of NBS (N-bromosuccinimide). NBS is a commonly used brominating reagent that can selectively introduce a bromine atom in the reaction. The NB bromination reaction is a commonly used organic synthesis reaction and can be used to synthesize compounds containing bromine groups. In the reaction, NBS can selectively introduce a bromine atom without introducing multiple bromine atoms such as dibromo or tribromo.

[0037] The synthesis principle of step S14 follows the Suzuki coupling reaction principle. The Suzuki coupling reaction is also an important palladium-catalyzed cross-coupling reaction for synthesizing aryl compounds. The principle of the reaction is to use a palladium catalyst to react an aryl halide with an arylboronic acid or borate ester in the presence of a base to generate a coupling product with an aryl-aryl bond. This reaction is usually carried out under mild conditions and has high efficiency, high selectivity, and wide applicability.

[0038] The synthesis principle of step S2 follows the Schiff-base reaction principle. The Schiff-base reaction is an important organic chemical reaction and is usually used to synthesize Schiff bases. The principle of this reaction is to carry out a condensation reaction between an aldehyde or ketone and an amine under acidic conditions to generate an imine containing a C=N bond. The Schiff-base reaction is usually carried out at room temperature or under heating conditions, and imine compounds with diverse structures and functions can be synthesized by selecting different combinations of aldehydes or ketones and amines.

[0039] Based on the above embodiments, the first solvent includes one or more of mesitylene, dioxane, n-butanol, and absolute ethanol. The use of these solvents alone and in combination can take into account solubility, temperature range, side reaction control, and operation efficiency.

[0040] In some specific embodiments, the second solvent includes N,N-dimethylformamide; the third solvent includes tetrahydrofuran; the fourth solvent includes a mixed solution of chlorobenzene and nitromethane; the fifth solvent includes tetrahydrofuran.

[0041] On the basis of the above embodiments, in step S2, the reaction under inert gas conditions specifically includes reacting at 115-125 °C for 71-73 h.

[0042] On the basis of the above embodiments, the preparation method further includes: In step S11, the reaction under inert gas conditions specifically includes reacting at 110-130 °C for 15-20 h; In step S12, the reaction under inert gas conditions specifically includes reacting at 20-35 °C for 10-20 h; In step S13, the reaction under inert gas conditions specifically includes reacting at 20-35 °C for 40-80 min; In step S14, the reaction under inert gas conditions specifically includes reacting at room temperature for 2-5 days.

[0043] In some specific embodiments, in step S2, the addition amounts of the components are as follows: ATT: 0.03-0.05 mmol, TFPPy: 0.03-0.05 mmol, 6M aqueous acetic acid solution: 0.11-0.13 mL; in step S3, the addition amounts of the components are as follows: ATT: 0.03-0.05 mmol, TAEPy: 0.03-0.05 mmol, 6M aqueous acetic acid solution: 0.11-0.13 mL.

[0044] In some specific embodiments, the preparation method further includes: In step S11, the addition amounts of the components are as follows: 1,2,4,5-tetrabromobenzene: 9-11 mmol, bis(triphenylphosphine)palladium(II) chloride: 0.5-1.5 mmol, 2-(tributylstannyl)thiophene: 42-65 mmol; In step S12, the addition amounts of the components are as follows: 2,2′,2′′,2′′-(1,2,4,5-benzenetetrayl)tetrathiophene: 4.5-5 mmol, N-bromosuccinimide: 25-35 mmol; In step S13, the addition amounts of the components are as follows: 2,2′,2′′,2′′-(1,2,4,5-benzenetetrayl)tetrakis[5-bromothiophene]: 1.1-1.5 mmol, iron(III) chloride: 8-10 mmol; In step S14, the addition amounts of the components are as follows: 2,5,9,12-tetrabromoanthra[1,2-b:4,3-b′:5,6-b′′:8,7-b′′]tetrathiophene: 1.5-2.0 mmol, 4-formylphenylboronic acid: 10-12 mmol, tetrakis(triphenylphosphine)palladium: 0.05-0.1 mmol, potassium carbonate: 12-16 mmol.

[0045] On the basis of the above embodiments, the addition amount of the first solvent is 0.1~1 mL; the addition amount of the second solvent is 10~20 mL; the addition amount of the third solvent is 80~110 mL; the addition amount of the fourth solvent is 70~90 mL; the addition amount of the fifth solvent is 25~35 mL.

[0046] The design solution provided by the present invention can innovatively synthesize a novel strongly conjugated organic structural unit, and based on this organic structural unit, stable and functional COFs materials can be reasonably constructed. This type of COFs has potential application value in the fields of environment, energy, and biomedicine, and the design of this structure has an excellent demonstration effect on guiding other functional structures.

[0047] The present invention also proposes an application of a strongly conjugated covalent organic framework material based on a tetrathiophene-anthracene unit, which includes: using the strongly conjugated covalent organic framework material based on the tetrathiophene-anthracene unit as a catalyst to photocatalytically reduce O2 to produce H2O2 in a water-ethanol mixed system.

[0048] Under the conditions of visible light and a mixed solution (10% EtOH), the two COFs materials designed in this application both exhibit good H2O2 photosynthesis activity, demonstrating good photocatalytic activity.

[0049] The following uses specific embodiments to illustrate this application.

[0050] Example 1: Example 1 is to clarify the key raw material, the aldehyde group building unit of the tetrathiophene-anthracene unit, of the COFs material designed by the present invention, and two novel COFs designed based on this structure.

[0051] Specifically, the preparation method of the ATT unit structure is as follows: A1: 2,2′,2′′,2′′-(1,2,4,5-benzenetetrayl)tetrathiophene component; First, add the reaction components to the reactor: 1,2,4,5-tetrabromobenzene: 12.5 mmol, bis(triphenylphosphine)palladium(II) chloride: 1.0 mmol, 2-(tributylstannyl)thiophene: 63 mmol.

[0052] The solvent is N,N-dimethylformamide: 15 mL; Then react at 120 °C for 20 h under an inert gas condition, and the crude product is purified by column chromatography to obtain the target product.

[0053] A2: 2,2′,2′′,2′′-(1,2,4,5-benzenetetrayl)tetrakis[5-bromothiophene]; First, add the reaction components into the reactor: 2,2′,2′′,2′′-(1,2,4,5-benzenetetrayl)tetrathiophene: 4.9 mmol, N-bromosuccinimide: 30 mmol.

[0054] The solvent is tetrahydrofuran: 100 mL.

[0055] Then, react at 25 °C for 18 h under an inert gas condition to obtain the target product.

[0056] A3: 2,5,9,12-tetrabromoanthra[1,2-b:4,3-b′:5,6-b′′:8,7-b′′]tetrathiophene; First, add the reaction components into the reactor: 2,2′,2′′,2′′-(1,2,4,5-benzenetetrayl)tetrakis[5-bromothiophene]: 1.4 mmol, iron(III) chloride: 9.25 mmol.

[0057] The solvent is a mixed solution of chlorobenzene: 50 mL and nitromethane: 30 mL.

[0058] Then, react at 30 °C for 60 min under an inert gas condition, and obtain the target product through a series of purifications.

[0059] A4: 4,4',4'',4'''-(anthra[1,2-b:4,3-b':5,6-b'':8,7-b'']tetrathiophene-2,5,9,12-tetrayl)tetrabenzaldehyde; First, add the reaction components into the reactor: 2,5,9,12-tetrabromoanthra[1,2-b:4,3-b′:5,6-b′′:8,7-b′′]tetrathiophene: 1.8 mmol, 4-formylphenylboronic acid: 12 mmol, tetrakis(triphenylphosphine)palladium(0): 0.1 mmol, potassium carbonate: 15 mmol.

[0060] The solvent is tetrahydrofuran: 30 mL.

[0061] Then, react for 2 days under an inert gas condition, and obtain the final target component after pickling purification.

[0062] A5: Preparation of COF-ATT: First, add the reaction components into the reactor: ATT: 0.05 mmol, TFPPy: 0.05 mmol, 6 M aqueous acetic acid solution: 0.11 mL; The solvent is 0.1 mL of mesitylene; Then, react at 120 °C for 72 h under an inert gas condition to prepare COF-ATT.

[0063] A6: Preparation of COF-ATTA: First, add the reaction components into the reactor: ATT: 0.05 mmol, TAEPy: 0.05 mmol, 6M aqueous acetic acid solution: 0.11 mL; The solvent is 0.3 mL of mesitylene; Then, react at 120 °C for 72 h under an inert gas condition to obtain COF-ATTA.

[0064] Example 2: Example 2 is based on the preparation method in Example 1, and Example 2 mainly elaborates the preparation method under another parameter. Specifically, the preparation method of the ATT unit structure is as follows: A1: 2,2′,2′′,2′′-(1,2,4,5-benzenetetrayl)tetrathiophene component; First, add the reaction components into the reactor: 1,2,4,5-tetrabromobenzene: 13.5 mmol, bis(triphenylphosphine)palladium(II) chloride: 1.2 mmol, 2-(tributylstannyl)thiophene: 65 mmol.

[0065] The solvent is N,N-dimethylformamide: 20 mL; Then, react at 120 °C for 25 h under an inert gas condition, and the crude product is purified by column chromatography to obtain the target product.

[0066] A2: 2,2′,2′′,2′′-(1,2,4,5-benzenetetrayl)tetrakis[5-bromothiophene]; First, add the reaction components into the reactor: 2,2′,2′′,2′′-(1,2,4,5-benzenetetrayl)tetrathiophene: 3.5 mmol, N-bromosuccinimide: 35 mmol.

[0067] The solvent is tetrahydrofuran: 80 mL.

[0068] Then, react at 25 °C for 20 h under an inert gas condition to obtain the target product.

[0069] A3: 2,5,9,12-tetrabromoanthra[1,2-b:4,3-b′:5,6-b′′:8,7-b′′]tetrathiophene; First, add the reaction components into the reactor: 2,2′,2′′,2′′-(1,2,4,5-benzenetetrayl)tetrakis[5-bromothiophene]: 1.6 mmol, iron(III) chloride: 9.3 mmol.

[0070] The solvent is a mixed solution of chlorobenzene: 55 mL and nitromethane: 35 mL.

[0071] Then, react at 30 °C for 75 min under an inert gas condition, and obtain the target product through a series of purifications.

[0072] A4: 4,4',4'',4'''-(Anthra[1,2-b:4,3-b':5,6-b'':8,7-b'']tetrathiophene-2,5,9,12-tetrayl)tetrabenzaldehyde; First, add the reaction components into the reactor: 2,5,9,12-tetra-bromoanthra[1,2-b:4,3-b′:5,6-b′′:8,7-b′′]tetrathiophene: 1.8 mmol, 4-formylphenylboronic acid: 12 mmol, tetrakis(triphenylphosphine)palladium: 0.1 mmol, potassium carbonate: 15 mmol.

[0073] The solvent is tetrahydrofuran: 30 mL.

[0074] Then, react under inert gas conditions for 3 days, and obtain the final target component after purification by pickling.

[0075] A5: Preparation of COF-ATT: First, add the reaction components into the reactor: ATT: 0.05 mmol, TFPPy: 0.05 mmol, 6M aqueous acetic acid solution: 0.11 mL; The solvent is 0.9 mL of dioxane; Then, react at 120 °C for 72 h under inert gas conditions to obtain COF-ATT.

[0076] A6: Preparation of COF-ATTA: First, add the reaction components into the reactor: ATT: 0.05 mmol, TAEPy: 0.05 mmol, 6M aqueous acetic acid solution: 0.11 mL; The solvent is 0.7 mL of dioxane; Then, react at 120 °C for 72 h under inert gas conditions to obtain COF-ATTA.

[0077] Example 3: The description of Example 3 is based on the preparation method in Example 2, and Example 3 mainly elaborates the preparation method under another parameter. Specifically, the preparation method of the ATT unit structure is as follows: A1: 2,2′,2′′,2′′-(1,2,4,5-benzenetetrayl)tetrathiophene component; First, add the reaction components into the reactor: 1,2,—tetrabromobenzene: 12.5 mmol, bis(triphenylphosphine)palladium(II) chloride: 1.0 mmol, 2-(tributylstannyl)thiophene: 63 mmol.

[0078] The solvent is N,N-dimethylformamide: 15 mL; Then, the reaction was carried out at 120 °C for 20 h under an inert gas atmosphere, and the target product was obtained by purifying the crude product through column chromatography.

[0079] A2: 2,2′,2′′,2′′-(1,2,4,5-Benzenetetrayl)tetrakis[5-bromothiophene]; First, the reaction components were added to a reactor: 2,2′,2′′,2′′-(1,2,4,5-benzenetetrayl)tetrathiophene: 4.9 mmol, N-bromosuccinimide: 30 mmol.

[0080] The solvent was tetrahydrofuran: 100 mL.

[0081] Then, the reaction was carried out at 25 °C for 18 h under an inert gas atmosphere to obtain the target product.

[0082] A3: 2,5,9,12-Tetrabromoanthra[1,2-b:4,3-b′:5,6-b′′:8,7-b′′]tetrathiophene; First, the reaction components were added to a reactor: 2,2′,2′′,2′′-(1,2,4,5-benzenetetrayl)tetrakis[5-bromothiophene]: 1.4 mmol, iron(III) chloride: 9.25 mmol.

[0083] The solvent was a mixed solution of chlorobenzene: 50 mL and nitromethane: 30 mL.

[0084] Then, the reaction was carried out at 30 °C for 60 min under an inert gas atmosphere, and the target product was obtained through a series of purification steps.

[0085] A4: 4,4',4'',4'''-(Anthra[1,2-b:4,3-b':5,6-b'':8,7-b'']tetrathiophene-2,5,9,12-tetrayl)tetrabenzaldehyde; First, the reaction components were added to a reactor: 2,5,9,12-tetrabromoanthra[1,2-b:4,3-b′:5,6-b′′:8,7-b′′]tetrathiophene: 1.8 mmol, 4-formylphenylboronic acid: 12 mmol, tetrakis(triphenylphosphine)palladium(0): 0.1 mmol, potassium carbonate: 15 mmol.

[0086] The solvent was tetrahydrofuran: 30 mL.

[0087] Then, the reaction was carried out for 5 days under an inert gas atmosphere, and the final target component was obtained after purification by acid washing.

[0088] A5: Preparation of COF-ATT: First, the reaction components were added to a reactor: ATT: 0.05 mmol, TFPPy: 0.05 mmol, 6 M aqueous acetic acid solution: 0.11 mL; The solvent is 0.9 mL of dioxane; Then, under an inert gas atmosphere, the reaction was carried out at 120 °C for 72 h to obtain COF-ATT.

[0089] A6: Preparation of COF-ATTA: First, the reaction components were added to a reactor: ATTA: 0.05 mmol, TAEPy: 0.05 mmol, 6 M aqueous acetic acid solution: 0.11 mL; The solvent is 0.3 mL of mesitylene; Then, under an inert gas atmosphere, the reaction was carried out at 120 °C for 72 h to obtain COF-ATTA.

[0090] Example 4 This example aims to illustrate the actual application effect of the COFs prepared by the present invention.

[0091] The COFs materials prepared in this application can be used as catalysts to photocatalytically reduce O2 to produce H2O2 in a water-ethanol system. In this example, the excellent catalytic performance of the prepared COFs will be demonstrated by the attached figures.

[0092] Reaction conditions: Visible light (λ ≥ 380 nm), the raw material is high-purity O2, and water and ethanol (sacrificial agent) are the reaction mixed solvents. Reaction parameters: 5 mg of photocatalyst, 60 mL of mixed solution (deionized water: ethanol = 9:1), sampling was taken every 30 min, and the color developer was titanium sulfate solution.

[0093] The reaction principle is: 1. Photocatalyst + hν (illumination) → h + + e – 2. e – + O2 → •O2 – + H + → •OOH 3. •OOH + e – + H + → H2O2 4. h + Is captured by the ethanol sacrificial agent After being irradiated by light, the COFs material is excited to generate excitons. The excitons undergo dissociation and transfer, and the active electrons are transferred to the active sites and finally transferred to the O2 molecules, continuing to activate O2, and finally converted into H2O2 through a series of electron and proton combinations.

[0094] Performance characterization: As Figure 2 shown, Figure 2 (a) is the XRD of COF-ATT, Figure 2(b) is the XRD pattern of COF-ATTA. It can be seen from the figure that the two novel COFs exhibit extremely high crystallinity, which means that their crystal structures are arranged in a very orderly manner, with good crystallization properties, and thus have better stability and catalytic activity.

[0095] Catalytic performance experiment: As Figure 3 shown, under visible light and water (10% ethanol) conditions, both COFs exhibit good H2O2 photosynthesis activity. Figure 3 (a) is the curve of the change in H2O2 concentration over time for the COF-ATT material under light irradiation. Figure 3 (b) is the curve of the change in H2O2 production rate over time for the COF-ATTA material under light irradiation.

[0096] The photosynthesis rates are 3945.38 µmol g -1 h -1 (COF-ATT) and 4875.62 µmol g -1 h -1 (COF-ATTA).

[0097] After the implementation of the present invention, it has at least the following beneficial effects: (1) The COFs material with a high conjugate structure designed in the present invention can improve the conjugate strength of the overall framework structure by constructing a novel tetrathiophene-anthracene molecular crystal framework, thereby enhancing the light absorption ability and promoting the rapid transfer of carriers along the molecular framework. (2) By constructing a well-defined molecular crystal framework with strong conjugation, the present invention greatly enriches the COFs structure system and reduces the time cost for understanding the structure-activity relationship between the conjugation degree and catalytic activity at the molecular level.

[0098] The above are the exemplary embodiments disclosed by the present invention. The order of disclosure of the above embodiments of the present invention is only for description and does not represent the superiority or inferiority of the embodiments. However, it should be noted that the discussion of any above embodiment is only exemplary and is not intended to imply that the scope of disclosure of the embodiments of the present invention (including the claims) is limited to these examples. Without departing from the scope defined by the claims, various changes and modifications can be made. The functions, steps, and / or actions of the method claims according to the disclosed embodiments here do not need to be executed in any specific order. In addition, although the elements disclosed in the embodiments of the present invention can be described or claimed in individual form, they can also be understood as multiple unless explicitly limited to the singular.

[0099] Those of ordinary skill in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope (including the claims) disclosed by the embodiments of the present invention is limited to these examples; under the concept of the embodiments of the present invention, the technical features in the above embodiments or different embodiments can also be combined, and there are many other variations in different aspects of the embodiments of the present invention as described above, and they are not provided in detail for the sake of brevity. Therefore, any omission, modification, equivalent replacement, improvement, etc. made within the spirit and principle of the embodiments of the present invention shall be included within the protection scope of the embodiments of the present invention.

Claims

1. A strongly conjugated covalent organic framework material based on a tetrathiophene-anthracene unit, characterized in that, Its structural formula is shown as COF-ATT or COF-ATTA: COF-ATT: ； COF-ATTA: 。 2. A preparation method of the strongly conjugated covalent organic framework material based on tetrathiophene-anthracene units according to claim 1, characterized in that, It includes the following steps: S1. React a composition containing 1,2,4,5-tetrabromobenzene under inert gas conditions, and purify it by column chromatography to obtain 2,2′,2′′,2′′-(1,2,4,5-benzenetetrayl)tetrathiophene; React a composition containing the obtained 2,2′,2′′,2′′-(1,2,4,5-benzenetetrayl)tetrathiophene under inert gas conditions to obtain 2,2′,2′′,2′′-(1,2,4,5-benzenetetrayl)tetra[5-bromothiophene]; React a composition containing the obtained 2,2′,2′′,2′′-(1,2,4,5-benzenetetrayl)tetra[5-bromothiophene] under inert gas conditions, and purify it to obtain 2,5,9,12-tetrabromoanthra[1,2-b:4,3-b′:5,6-b′′:8,7-b′′]tetrathiophene; React a composition containing the obtained 2,5,9,12-tetrabromoanthra[1,2-b:4,3-b′:5,6-b′′:8,7-b′′]tetrathiophene under inert gas conditions, and purify it by pickling to obtain ATT; Among them, the ATT is 4,4',4'',4'''-(anthra[1,2-b:4,3-b':5,6-b'':8,7-b'']tetrathiophene-2,5,9,12-tetrayl)tetrabenzaldehyde, and its structural formula is: ； S2. Dissolve the ATT obtained in step S1, the pairing reagent, and 6M aqueous acetic acid solution in the first solvent, and react under inert gas conditions; When the pairing reagent is TFPPy, COF-ATT is obtained; When the pairing reagent is TAEPy, COF-ATTA is obtained.

3. The preparation method of the strongly conjugated covalent organic framework material based on tetrathiophene-anthracene units according to claim 2, characterized in that, The specific steps of the above step S1 include: S11. Add 1,2,4,5-tetrabromobenzene, bis(triphenylphosphine)palladium(II) chloride, and 2-(tributylstannyl)thiophene to the second solvent, react under inert gas conditions, and purify the crude product by column chromatography to obtain 2,2′,2′′,2′′-(1,2,4,5-benzenetetrayl)tetrathiophene; S12. Add the 2,2′,2′′,2′′-(1,2,4,5-benzenetetrayl)tetrathiophene obtained in step S11 and N-bromosuccinimide to the third solvent, and react under inert gas conditions to obtain 2,2′,2′′,2′′-(1,2,4,5-benzenetetrayl)tetra[5-bromothiophene]; S13. Add the 2,2′,2′′,2′′-(1,2,4,5-benzenetetrayl)tetra[5-bromothiophene] obtained in step S12 and iron chloride to the fourth solvent, react under inert gas conditions and purify to obtain 2,5,9,12-tetrabromoanthra[1,2-b:4,3-b′:5,6-b′′:8,7-b′′]tetrathiophene; S14. Add the 2,5,9,12-tetrabromoanthra[1,2-b:4,3-b′:5,6-b′′:8,7-b′′]tetrathiophene prepared in step S13, 4-formylphenylboronic acid, tetrakis(triphenylphosphine)palladium, and potassium carbonate into the fifth solvent, react under an inert gas condition, and obtain 4,4',4'',4'''-(anthra[1,2-b:4,3-b':5,6-b'':8,7-b'']tetrathiophene-2,5,9,12-tetrayl)tetrabenzaldehyde after pickling and purification.

4. The preparation method of the strongly conjugated covalent organic framework material based on the tetrathiophene-anthracene unit according to claim 2, characterized in that The first solvent includes one or more of mesitylene, dioxane, n-butanol, and absolute ethanol.

5. The preparation method of the strongly conjugated covalent organic framework material based on tetrathiophene-anthracene unit according to claim 3, characterized in that, The second solvent includes N,N-dimethylformamide; the third solvent includes tetrahydrofuran; the fourth solvent includes a mixed solution of chlorobenzene and nitromethane; the fifth solvent includes tetrahydrofuran.

6. The preparation method of the strongly conjugated covalent organic framework material based on tetrathiophene-anthracene unit according to claim 2, characterized in that, In step S2, the reaction under an inert gas condition specifically includes reacting at 115 - 125 °C for 71 - 73 h.

7. The preparation method of the strongly conjugated covalent organic framework material based on tetrathiophene-anthracene unit according to claim 3, characterized in that, Also included: In step S11, the reaction under an inert gas condition specifically includes reacting at 110 - 130 °C for 15 - 20 h; In step S12, the reaction under an inert gas condition specifically includes reacting at 20 - 35 °C for 10 - 20 h; In step S13, the reaction under an inert gas condition specifically includes reacting at 20 - 35 °C for 40 - 80 min; In step S14, the reaction under an inert gas condition specifically includes reacting at room temperature for 2 - 5 days.

8. The preparation method of the strongly conjugated covalent organic framework material based on tetrathiophene-anthracene unit according to claim 2, wherein, In step S2, the addition amounts of each component are as follows: ATT: 0.03 - 0.05 mmol, TFPPy: 0.03 - 0.05 mmol, 6M aqueous acetic acid solution:

0. I1 - 0.13 mL; in step S3, the addition amounts of each component are as follows: ATT: 0.03 - 0.05 mmol, TAEPy: 0.03 - 0.05 mmol, 6M aqueous acetic acid solution: 0.11 - 0.13 mL.

9. The preparation method of the strongly conjugated covalent organic framework material based on a tetrathiophene-anthracene unit according to claim 3, wherein Also included: In step S11, the addition amounts of each component are as follows: 1,2,4,5-tetrabromobenzene: 9 - 11 mmol, bis(triphenylphosphine)palladium(II) chloride: 0.5 - 1.5 mmol, 2-(tributylstannyl)thiophene: 42 - 65 mmol; In step S12, the addition amounts of each component are as follows: 2,2′,2′′,2′′-(1,2,4,5-benzenetetrayl)tetrathiophene: 4.5 - 5 mmol, N-bromosuccinimide: 25 - 35 mmol; In step S13, the addition amounts of each component are as follows: 2,2′,2′′,2′′-(1,2,4,5-benzenetetrayl)tetrakis[5-bromothiophene]: 1.1 - 1.5 mmol, iron(III) chloride: 8 - 10 mmol; In step S14, the addition amounts of each component are as follows: 2,5,9,12-tetrabromoanthra[1,2-b:4,3-b′:5,6-b′′:8,7-b′′]tetrathiophene: 1.5 - 2.0 mmol, 4-formylphenylboronic acid: 10 - 12 mmol, tetrakis(triphenylphosphine)palladium: 0.05 - 0.1 mmol, potassium carbonate: 12 - 16 mmol.

10. Application of a strongly conjugated covalent organic framework material based on a tetrathiophene-anthracene unit, characterized in that, Included: A strongly conjugated covalent organic framework material based on a tetrathiophene-anthracene unit is used as a catalyst for photocatalytic O2 reduction to produce H2O2 in a water-ethanol mixed system.

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