CN115785365B

CN115785365B - Porous crystalline quinolyl organic framework rich in (N≡N) -coordination motifs, preparation method and application thereof

Info

Publication number: CN115785365B
Application number: CN202211461993.3A
Authority: CN
Inventors: 黄胜利; 李彦霖; 薛瑞
Original assignee: Beijing Institute of Technology BIT
Current assignee: Beijing Institute of Technology BIT
Priority date: 2022-11-17
Filing date: 2022-11-17
Publication date: 2023-07-18
Anticipated expiration: 2042-11-17
Also published as: CN115785365A

Abstract

The invention relates to a porous crystalline quinolyl organic framework rich in (N-N) -coordination primitives, a preparation method and application thereof, and belongs to the technical field of crystalline organic frameworks. The organic framework takes 1,3, 5-tri (2-formylpyridin-5-yl) benzene as a monomer, and N atoms on the 1,3, 5-tri (2-formylpyridin-5-yl) benzene and N atoms on a quinoline ring form a (N≡N) -coordination primitive of a five-membered ring. The quinolyl organic framework has the advantages of good chemical stability, firm pore channel structure, enhanced coordination capacity of (N≡N) -primitives and the like, and can be used as a metal catalyst carrier to play a good role in supporting and stabilizing a metal catalyst.

Description

Porous crystalline quinolyl organic framework rich in (N≡N) -coordination motifs, preparation method and application thereof

Technical Field

The invention relates to a porous crystalline quinolyl organic framework rich in (N-N) -coordination primitives, a preparation method and application thereof, and belongs to the technical field of crystalline organic frameworks.

Background

Conventional porous materials such as porous carbon materials, metal oxides, molecular sieves, etc. are often used as commercial metal catalyst carriers and have been widely used in the chemical, pharmaceutical, energy industries, etc. However, the pore structure of the traditional commercial carrier is not easy to control and the pore size distribution is not uniform, and the catalyst has no strong interaction with the metal catalyst, so that the catalyst cannot be uniformly dispersed, and metal particles are easy to fall off in the catalytic process, thereby causing the loss of active centers. In addition, the pore canal of the carrier is not easy to control, the specific surface area is small, and the like, so that the diffusion of the reaction substrate to the active center and the product selectivity induced by the space limitation are limited, and the development of the novel catalyst carrier is of great significance.

Covalent organic frameworks are periodic network structures of porous crystalline states formed by covalent bonding of organic molecular monomers composed of light elements. The porous organic polymer is widely applied to the applications of gas adsorption and separation, chemical sensing, catalysis, photoelectron, energy storage and the like due to the high specific surface area, structural designability, chemical diversity and functional adjustability, and is a novel porous organic polymer. Along with the research, the chelating locus including N, O, S element is introduced into a covalent organic framework to form a metal catalyst carrier, and the chelating locus is coordinated with metal ions, so that metal particles can be uniformly dispersed in the carrier, the catalyst is anchored on the carrier and is not easy to fall off, the catalytic capacity of a metal active center is regulated, and the high activity and high stability of the catalyst are realized. In addition, the covalent organic framework is easy to carry out functional modification, so that the selectivity of the substrate is improved, the substrate diffusion can be accelerated due to the high specific surface area and the regular and ordered pore structure, and the contact with metal catalytic sites is greatly improved. Therefore, the use of covalent organic frameworks as catalyst supports to support metal active sites for the preparation of heterogeneous catalysts has become a hotspot in research in the field of materials.

The formation and the fracture of the dynamic covalent bond with weak bond energy are reversible, and the construction of the crystalline organic framework is easier to realize by using the dynamic covalent bond. However, organic frameworks constructed by dynamic covalent bonds have poor chemical stability and the frameworks collapse during use. For example, a boroxine-linked covalent organic framework is susceptible to water molecules and other protic solvents. The amino and aldehyde group precursors are widely available, and the formation conditions of the imine bond are mild and easy to control, so that the imine bond is widely applied to the construction of crystalline organic frameworks. However, imine bonds are typically dynamic covalent bonds, are relatively easy to form and break, have poor chemical stability, and limit their application in the catalytic field. At present, few catalyst organic framework carriers with high chemical stability are reported. The development of a catalyst support with high stability and high efficiency has become a challenging topic in the field of crystalline organic frameworks.

When the organic frame structure with high chemical stability is constructed, the monomers need to be connected by covalent bonds with high bond energy. In recent years, some researchers have attempted to construct stable covalent organic frameworks using high bond energy covalent bonds, including one-pot and post-modification methods. The one-pot method has short time consumption and simple steps. For example, matthew J.R et al use a hydrothermal rearrangement recrystallization process to achieve crystalline amide bond frameworks with better chemical stability. However, the reversible conversion of amide bonds requires a high-temperature and high-pressure environment, and the conditions are severe, so that the reversible conversion is not suitable for wide use. Wei Wang et al constructed a stable imidazole-linked covalent organic framework using the Debucs-La Ji Xiefu St method. Yubin Dong et al constructed covalent organic frameworks based on alpha-aminonitriles and on quinoline motifs, respectively, using the Style and Povarov reactions. Arne Thomas et al constructed vinyl covalent organic frameworks by cyclic trimerization and aldol condensation. YIngjie Zhao et al constructed a C-C bond-linked two-dimensional crystalline framework by [2+2] cycloaddition dimerization based on pi-pi stacking between monomer layers. The crystalline frameworks are synthesized by a stable covalent bond one-pot method. The bond energy of different covalent bonds determines the dynamic reversibility and the difficulty of the structure of the crystalline organic frame. When a high-chemical stable frame is constructed by a one-pot method, the frame part which is not arranged with low entropy is not easy to realize self-repair due to weak reversibility of a covalent bond with high bond energy, and the frame crystallization quality is very easy to be poor. In contrast, covalent bonds with weaker bond energy have stronger dynamic reversibility, and the construction of crystalline frameworks is easy to realize by using the covalent bonds. The post-modification method adopts dynamic covalent bonds with weaker bond energy to obtain crystalline organic frameworks, and then the dynamic covalent bonds are converted into high-stability covalent bonds through organic reactions with mild conditions, so that the crystalline organic frameworks with high chemical stability are obtained. Currently, more and more covalent organic frameworks are modified by post-modification to obtain porous materials with various functions and maintained topological structures, and the method has proved to be a very effective method. For example, yaghi et al demonstrate that imine-linked frameworks can be converted to more stable amide-or thiazole-linked covalent organic frameworks by single-or multi-step post-modification. Yi Liu et al converted the imine to quinoline by Povarov reaction to prepare a covalent organic framework with significant chemical stability enhancement, pore surface functionality and pi electron delocalization modification. In general, although the post-modification method has more reaction steps than the one-pot method, the problem of difficult crystallization of the frame in the process of covalent bond connection with high bond energy can be overcome, and the transition from low stability to high stability of the constructed crystalline organic frame can be realized, so that the improvement and improvement of chemical stability can be realized on the premise of keeping the crystalline structure of the organic frame.

In this context, it is very challenging to develop a highly chemically stable organic framework containing metal coordination sites and as a support for metal catalysts, thereby constructing a highly active, highly selective and chemically stable organic framework metal catalyst system.

Disclosure of Invention

In view of the above, the present invention aims to provide a porous crystalline quinolinyl organic framework rich in (N≡N) -ligand, a preparation method and application thereof.

In order to achieve the above purpose, the technical scheme of the invention is as follows:

a porous crystalline quinolyl organic framework rich in (N≡N) -coordination motifs has the structural formula:

wherein, the liquid crystal display device comprises a liquid crystal display device,is->H ₂ N-R-NH ₂ Is->

The preparation method of the porous crystalline quinolyl organic framework rich in (N≡N) -coordination motifs comprises the following steps:

(1) 1,3, 5-mesitylene and ethanol with the volume ratio of 1:1-5:1 are taken as mixed solvents, 1,3, 5-tri (2-formylpyridinium-5 yl) benzene and a multidentate amino precursor which are weighed according to the stoichiometric ratio are dissolved, and the mixed solution of reactants is obtained after uniform mixing;

(2) Adding glacial acetic acid water solution serving as a catalyst into the reactant mixed solution, and reacting for 30-80 hours at the temperature of 100-150 ℃; after the reaction is finished, filtering, washing and drying to obtain an imine bond framework compound;

(3) Uniformly dispersing the imine bond framework compound and aromatic alkyne in toluene, and reacting for 24-72 hours at 100-150 ℃ by taking boron trifluoride diethyl ether and tetrachlorobenzoquinone as catalysts; after the reaction is finished, filtering, washing and drying to obtain a porous crystalline quinolyl organic framework rich in (N≡N) -coordination elements;

wherein the multi-tooth amino precursor is a bidentate amino precursor or a tridentate amino precursor; the bidentate amino precursor is 1, 4-phenylenediamine or 4,4' -diaminobiphenyl; the tridentate amino precursor is 2,4, 6-tris (4-aminophenyl) -1,3, 5-triazine or 1,3, 5-tris (4-aminophenyl) benzene.

Preferably, in the step (2), the concentration of the glacial acetic acid aqueous solution is 3-9 mol/L, and the volume ratio of the glacial acetic acid aqueous solution to the mixed solvent in the step (1) is 1:10-1:20.

Preferably, in the step (3), the molar ratio of the imine bond framework compound to the aromatic alkyne is 1:1-1:3; the molar ratio of boron trifluoride diethyl etherate, tetrachlorobenzoquinone and aromatic alkyne is 1:1:2-10.

Preferably, in the step (3), the aromatic alkyne is phenylacetylene, p-nitroacetylene, 4-ethynyl-alpha, alpha-benzotrifluoride, 4-dimethylaminophenylacetylene or 4-tert-butylphenylacetylene.

The invention discloses application of a porous crystalline quinolyl organic framework rich in (N≡N) -coordination motifs, which is used as a metal catalyst carrier.

Preferably, the porous crystalline quinolyl organic framework is uniformly dispersed in acetonitrile solution of metal salt, the reaction temperature is controlled to be 60-120 ℃, and the mixture is stirred and reacted for 5-20 hours; after the reaction is finished, filtering, washing and drying to obtain the metal-loaded quinolyl covalent organic framework.

Preferably, the molar ratio of the porous crystalline quinolyl organic framework to the metal salt is 200:1-1:3. The metal loading is 0.5-95%. The loadable metal comprises more than one of Cu, pt, ir, pd, ni, co, ir and Ru.

Preferably, the metal-loaded quinolinyl covalent organic framework is used as a catalyst for photocatalytic hydrogen production.

Preferably, the metal-loaded quinolinyl covalent organic framework is used as a catalyst for photocatalytic hydrogenation.

Advantageous effects

The invention provides a porous crystalline quinolyl organic framework rich in (N-N) -coordination units, which takes 1,3, 5-tri (2-formylpyridyl-5-yl) benzene as a monomer, has novel covalent organic framework structure and good framework stability, and N atoms on 1,3, 5-tri (2-formylpyridyl-5-yl) benzene and N atoms on quinoline rings form (N-N) -coordination units of five-membered rings, so that the porous crystalline quinolyl organic framework has stronger coordination capability than a single N-coordination unit, can have high anchoring capability of the covalent organic framework to a metal catalytic center, and can enhance the catalytic activity of the metal center.

The invention provides a preparation method of a porous crystalline quinolyl organic framework rich in (N-N) -coordination motifs, which not only greatly improves the chemical stability of the organic framework and maintains the crystalline structure of the organic framework by modifying the quinolyl organic framework after a Povarov reaction. The N atom of the quinoline ring has stronger coordination ability than the N atom of the imine bond. The formation of quinoline motifs can enhance the conjugation of the framework, and the electron abundance of the framework and the (N≡N) -coordination motifs can be regulated and controlled by changing the types of alkynyl substrates, thereby affecting the overall catalytic performance.

The invention provides an application of a porous crystalline quinolyl organic framework rich in (N-N) -coordination primitives, which has the advantages of good chemical stability, firm pore channel structure, enhanced coordination capacity of the (N-N) -primitives and the like, and can be used as a metal catalyst carrier to play a good role in supporting and stabilizing a metal catalyst.

Drawings

FIG. 1 is a simulated graph of COF-I-N as described in example 1.

FIG. 2 is a simulated graph of COF-Q-N as described in example 1.

FIG. 3 is an X-ray diffraction pattern of the materials described in examples 1-4 and comparative example 1.

FIG. 4 is an infrared spectrum of the materials described in examples 1-4 and comparative example 1.

FIG. 5 shows the results of hydrogen production for recycling Pt@COF-Q-N described in example 14.

FIG. 6 is a graph of the nitrogen adsorption and desorption curve and pore size distribution of Pt@COF-Q-N described in example 14.

FIG. 7 is a graph showing the adsorption and desorption curves and pore size distribution of nitrogen after the application of Pt@COF-Q-N described in example 14.

FIG. 8 is a graph showing the results of hydrogen production using the Pt@COF-I-N recycling described in comparative example 2.

FIG. 9 is a graph showing the adsorption and desorption curves and pore size distribution of nitrogen using Pt@COF-I-N as described in comparative example 2.

FIG. 10 is a graph showing the adsorption and desorption curves and pore size distribution of nitrogen after the application of Pt@COF-I-N described in comparative example 2.

Detailed Description

The present invention will be described in further detail with reference to specific examples.

The reaction flow of the invention is as follows:

wherein, the liquid crystal display device comprises a liquid crystal display device, represents a metal ion, I represents an imine bond, Q represents a quinoline moiety, x represents an element, x is N or C, N represents a benzene ring number, N is 1 or 2, and COF represents a covalent organic framework.

In the following examples and comparative examples, (1) photocatalytic hydrogen generator performance test: 1-50 mg of porous organic framework loaded with metal catalyst is dispersed in deionized water and transferred into a 10mL special photocatalytic bottle under the nitrogen atmosphere at the temperature of 25-35 ℃. The concentration of the ascorbic acid as an electron sacrificial agent is 0.1-10 mmol/mL. The LED lamp with the power of 10W and the wavelength of 450nm is used as a light source, and the illumination time is 1-40 hours. After the reaction is finished, taking gas in the bottle, detecting the hydrogen production amount by gas chromatography, and researching the photocatalytic hydrogen production effect. (2) photocatalytic hydrogenation Performance test: 1-50 mg of the porous organic framework loaded with the metal catalyst is dispersed in methanol and transferred into a 10mL special photocatalytic bottle under the nitrogen atmosphere at the temperature of 25-35 ℃. Nitrobenzene is used as a reaction substrate, ascorbic acid is used as an electron sacrificial agent, the concentration of the reaction substrate is controlled to be 0.001-1 mmol/mL, and the concentration of the sacrificial agent is controlled to be 0.1-10 mmol/mL. The LED lamp with the power of 10W and the wavelength of 450nm is used as a light source, and the illumination time is 1-40 hours. And after the reaction is finished, taking liquid in the bottle, filtering to remove the catalyst, and analyzing the product by gas chromatography to study the effect of the photocatalytic hydrogenation reaction.

Comparative example 1

1,3, 5-tris (2-formylpyridin-5-yl) benzene (11.79 mg,0.03 mmol) and 2,4, 6-tris (4-aminophenyl) -1,3, 5-triazine (10.62 mg,0.03 mmol) were added to the ampoule, 1mL of N, N-dimethylformamide was further added thereto, and the mixture was sonicated for 10 minutes to obtain a homogeneous reaction solution, and an aqueous glacial acetic acid solution having a concentration of 6mol/L was used as a catalyst (the ratio of the addition amount of the aqueous glacial acetic acid solution to the total solvent volume was 1:15), and the reaction temperature was controlled to 120℃to react in the ampoule for 72 hours. Filtering after the reaction is finished, washing a filter cake by tetrahydrofuran, and drying to obtain a powdery product. The product was characterized by powder X-ray diffractometer, the spectrum was peak-free, indicating that the product was amorphous.

Comparative example 2

1,3, 5-tris (2-formylpyridin-5-yl) benzene (11.79 mg,0.03 mmol) and 2,4, 6-tris (4-aminophenyl) -1,3, 5-triazine (10.62 mg,0.03 mmol) were added to the ampoule, 1mL of 1,3, 5-mesitylene was further added, and the mixture was sonicated for 10 minutes to obtain a homogeneous reaction solution, and an aqueous glacial acetic acid solution having a concentration of 6mol/L was used as a catalyst (the ratio of the addition amount of the aqueous glacial acetic acid solution to the total solvent volume was 1:15), and the reaction temperature was controlled to 120℃to react in the ampoule for 72 hours. Filtering after the reaction is finished, washing a filter cake by tetrahydrofuran, and drying to obtain a powdery product. The product was characterized by powder X-ray diffractometer, the spectrum was peak-free, indicating that the product was amorphous.

Comparative example 3

1,3, 5-tris (2-formylpyridin-5-yl) benzene (11.79 mg,0.03 mmol) and 2,4, 6-tris (4-aminophenyl) -1,3, 5-triazine (10.62 mg,0.03 mmol) were added to the ampoule, and 1mL of ethanol was further added thereto, followed by sonication for 10 minutes to obtain a homogeneous reaction solution, and an aqueous glacial acetic acid solution having a concentration of 6mol/L was used as a catalyst (the ratio of the addition amount of the aqueous glacial acetic acid solution to the total solvent volume was 1:15), and the reaction temperature was controlled to 120℃to react in the ampoule for 72 hours. Filtering after the reaction is finished, washing a filter cake by tetrahydrofuran, and drying to obtain a powdery product. The product was characterized by powder X-ray diffractometer, the spectrum was peak-free, indicating that the product was amorphous.

Comparative example 4

1,3, 5-tris (2-formylpyridin-5-yl) benzene (11.79 mg,0.03 mmol) and 2,4, 6-tris (4-aminophenyl) -1,3, 5-triazine (10.62 mg,0.03 mmol) were added to an ampoule, and then 1mL of a mixed solvent of 1,3, 5-mesitylene and ethanol (volume ratio: 1:2) was added thereto, followed by sonication for 10 minutes to obtain a homogeneous reaction solution, and an aqueous solution of glacial acetic acid having a concentration of 6mol/L was used as a catalyst (the ratio of the addition amount of the aqueous solution of glacial acetic acid to the volume of the total solvent: 1:15), and the reaction temperature was controlled at 120℃to react in the ampoule for 72 hours. Filtering after the reaction is finished, washing a filter cake by tetrahydrofuran, and drying to obtain a powdery product. Powder X-ray diffraction patterns have a weak peak at 2θ=4.1°, indicating that a product with a good crystalline state is not obtained.

Comparative example 5

1,3, 5-tris (2-formylpyridin-5-yl) benzene (11.79 mg,0.03 mmol) and 2,4, 6-tris (4-aminophenyl) -1,3, 5-triazine (10.62 mg,0.03 mmol) were added to an ampoule, and then 1mL of a mixed solvent of 1,3, 5-mesitylene and ethanol (volume ratio: 10:1) was added thereto, followed by sonication for 10 minutes to obtain a homogeneous reaction solution, and an aqueous solution of glacial acetic acid having a concentration of 6mol/L was used as a catalyst (the ratio of the addition amount of the aqueous solution of glacial acetic acid to the volume of the total solvent: 1:15), and the reaction temperature was controlled at 120℃to react in the ampoule for 72 hours. Filtering after the reaction is finished, washing a filter cake by tetrahydrofuran, and drying to obtain a powdery product. Powder X-ray diffraction patterns have weak peaks at 2θ=4.1°, indicating that no well-crystalline product is obtained.

Example 1

1,3, 5-tris (2-formylpyridin-5-yl) benzene (11.79 mg,0.03 mmol) and 2,4, 6-tris (4-aminophenyl) -1,3, 5-triazine (10.62 mg,0.03 mmol) were added to an ampoule, and then 1mL of a mixed solvent of 1,3, 5-mesitylene and ethanol (volume ratio: 1:1) was added thereto, followed by sonication for 10 minutes to obtain a homogeneous reaction solution, and an aqueous solution of glacial acetic acid having a concentration of 6mol/L was used as a catalyst (the ratio of the addition amount of the aqueous solution of glacial acetic acid to the volume of the total solvent: 1:15), and the reaction temperature was controlled at 120℃to react in the ampoule for 72 hours. After the reaction, the mixture was filtered, and the filter cake was washed with tetrahydrofuran and dried to give a powdery product, an imine bond covalent organic framework (COF-I-N), in a yield of 94%. Powder X-ray diffraction patterns have a medium strong peak at 2θ=4.1°, and a weak peak at 2θ=6.9 °, 7.9 °, 10.3 °; consistent with the simulation software simulation of Materials Studio 2020, the product was shown to be crystalline. A simulation diagram obtained by the Materials Studio 2020 simulation software is shown in FIG. 1. The unit cell parameters of COF-I-N are: the space group is P-6, α＝β＝90°,γ＝120°。

The COF-I-N and phenylacetylene are uniformly dispersed in toluene solution according to the mass ratio of 1:2, boron trifluoride diethyl etherate and tetrachlorobenzoquinone (the mass ratio of boron trifluoride diethyl etherate, tetrachlorobenzoquinone and phenylacetylene is 1:1:2) are used as catalysts, the reaction temperature is controlled to be 110 ℃, and the reaction is carried out for 48 hours. After the reaction is finished, filtering, washing filter cakes respectively by using saturated sodium bicarbonate aqueous solution and tetrahydrofuran, and drying to obtain the porous crystalline quinolyl organic framework COF-Q-N rich in (N≡N) -coordination elements, wherein the conversion rate is 48%. A simulation diagram obtained by the Materials Studio2020 simulation software is shown in FIG. 2. The unit cell data for COF-Q-N are as follows: the space group is P-6,α＝β＝90°,γ＝120°。

the COF-I-N is dispersed in 6mol/L hydrochloric acid and 6mol/L sodium hydroxide aqueous solution in turn at normal temperature, the soaking time is 12 hours, then the solution is filtered, filter cakes are respectively washed by water and tetrahydrofuran, and the filter cakes are characterized by a powder X-ray diffractometer and a Fourier transform infrared spectrometer after being dried. After being soaked in strong acid and alkali solution, the X-ray diffraction spectrogram and the infrared spectrum spectrogram are changed, and the spectrum peak of the X-ray diffraction spectrogram at 2 theta=4.1 DEG disappears, which indicates that the COF-I-N framework structure is destroyed and the chemical stability is poor.

The COF-Q-N is dispersed in 12mol/L hydrochloric acid and 12mol/L sodium hydroxide aqueous solution in turn at normal temperature, the soaking time is 24 hours, then the solution is filtered, filter cakes are respectively washed by water and tetrahydrofuran, and after drying, the filter cakes are characterized by a Fourier transform infrared spectrometer and a powder X-ray diffractometer, and the results are shown in figures 3-4. The infrared spectrum and the X-ray diffraction spectrum of the COF-Q-N are almost unchanged before and after soaking in strong acid and strong alkali solutions, which shows that the COF-Q-N has better chemical stability.

Example 2

1,3, 5-tris (2-formylpyridin-5-yl) benzene (11.79 mg,0.03 mmol) and 2,4, 6-tris (4-aminophenyl) -1,3, 5-triazine (10.62 mg,0.03 mmol) were added to an ampoule, and then 1mL of a mixed solvent of 1,3, 5-mesitylene and ethanol (volume ratio: 2:1) was added thereto, followed by sonication for 10 minutes to obtain a homogeneous reaction solution, and an aqueous solution of glacial acetic acid having a concentration of 6mol/L was used as a catalyst (the ratio of the addition amount of the aqueous solution of glacial acetic acid to the volume of the total solvent: 1:15), and the reaction temperature was controlled at 120℃to react in the ampoule for 72 hours. After the reaction is finished, filtering, washing a filter cake by tetrahydrofuran, and drying to obtain a powdery product of an imine bond covalent organic framework (COF-I-N) with the yield of 96%. The powder X-ray diffraction pattern had strong peaks at 2θ=4.1°, weak peaks at 2θ=6.9 °, 7.9 °, 10.3 °, consistent with the material Studio 2020 simulation software simulation, indicating that the product was crystalline and exhibited the strongest crystalline state in the solvent conditions tried.

The COF-I-N and the p-nitroacetylene are uniformly dispersed in toluene solution according to the mass ratio of 1:2, boron trifluoride diethyl etherate and chloranil (the mass ratio of boron trifluoride diethyl etherate, chloranil and the p-nitroacetylene is 1:1:2) are used as catalysts, the reaction temperature is controlled to be 110 ℃, and the reaction is carried out for 48 hours. After the reaction is finished, filtering, washing filter cakes by saturated sodium bicarbonate aqueous solution and tetrahydrofuran respectively, and drying to obtain the porous crystalline quinolyl organic framework COF-Q-N rich in (N≡N) -coordination elements, wherein the conversion rate is 56%.

The COF-Q-N is sequentially dispersed in 12mol/L hydrochloric acid and 12mol/L sodium hydroxide aqueous solution at normal temperature, the soaking time is 24 hours, then the solution is filtered, filter cakes are respectively washed by water and tetrahydrofuran, the filter cakes are dried and are characterized by a Fourier transform infrared spectrometer and a powder X-ray diffractometer, the results are shown in the figures 3-4, and the results show that the infrared spectrogram and the X-ray diffractometer are almost unchanged before and after soaking in strong acid and strong alkali solutions, so that the COF-Q-N has better chemical stability.

Example 3

1,3, 5-tris (2-formylpyridin-5-yl) benzene (11.79 mg,0.03 mmol) and 2,4, 6-tris (4-aminophenyl) -1,3, 5-triazine (10.62 mg,0.03 mmol) were added to an ampoule, and then 1mL of a mixed solvent of 1,3, 5-mesitylene and ethanol (volume ratio: 5:1) was added thereto, followed by sonication for 10 minutes to obtain a homogeneous reaction solution, and an aqueous solution of glacial acetic acid having a concentration of 6mol/L was used as a catalyst (the ratio of the addition amount of the aqueous solution of glacial acetic acid to the volume of the total solvent: 1:15), and the reaction temperature was controlled at 120℃to react in the ampoule for 72 hours. After the reaction is finished, filtering, washing a filter cake by tetrahydrofuran, and drying to obtain a powdery product of an imine bond covalent organic framework (COF-I-N) with the yield of 95%. The powder X-ray diffraction pattern had a median peak at 2θ=4.1°, and a weak peak at 2θ=6.9 °, 7.9 °, 10.3 °, all consistent with the material Studio 2020 simulation software simulation, indicating that the product was crystalline.

COF-I-N and 4-ethynyl- α, α, α -benzotrifluoride were uniformly dispersed in toluene solution at a mass ratio of 1:2, boron trifluoride diethyl etherate and chloranil (the mass ratio of boron trifluoride diethyl etherate, chloranil to 4-ethynyl- α, α, α -benzotrifluoride was 1:1:2) were used as catalysts, and the reaction temperature was controlled at 110 ℃ for 48 hours. After the reaction is finished, filtering, washing filter cakes by saturated sodium bicarbonate water solution and tetrahydrofuran respectively, and drying to obtain COF-Q-N with the conversion rate of 38%.

Example 4

1,3, 5-tris (2-formylpyridin-5-yl) benzene (11.79 mg,0.03 mmol) and 2,4, 6-tris (4-aminophenyl) -1,3, 5-triazine (10.62 mg,0.03 mmol) were added to an ampoule, and then 1mL of a mixed solvent of 1,3, 5-mesitylene and ethanol (volume ratio: 2:1) was added thereto, followed by sonication for 10 minutes to obtain a homogeneous reaction solution, and an aqueous solution of glacial acetic acid having a concentration of 6mol/L was used as a catalyst (the ratio of the addition amount of the aqueous solution of glacial acetic acid to the volume of the total solvent: 1:15), and the reaction temperature was controlled at 120℃to react in the ampoule for 72 hours. After the reaction is finished, filtering, washing a filter cake by tetrahydrofuran, and drying to obtain COF-I-N, wherein the yield is 96%.

The COF-I-N and 4-dimethylaminophenylacetylene are uniformly dispersed in toluene solution according to the mass ratio of 1:2, boron trifluoride diethyl etherate and chloranil (the mass ratio of boron trifluoride diethyl etherate, chloranil and 4-dimethylaminophenylacetylene is 1:1:2) are used as catalysts, the reaction temperature is controlled to be 110 ℃, and the reaction is carried out for 48 hours. After the reaction is finished, filtering, washing filter cakes by saturated sodium bicarbonate water solution and tetrahydrofuran respectively, and drying to obtain COF-Q-N with the conversion rate of 51%.

Example 5

The COF-I-N and the 4-tertiary butyl phenyl acetylene are uniformly dispersed in toluene solution according to the mass ratio of 1:2, boron trifluoride diethyl etherate and chloranil (the mass ratio of boron trifluoride diethyl etherate, chloranil and the 4-tertiary butyl phenyl acetylene is 1:1:2) are used as catalysts, the reaction temperature is controlled to be 110 ℃, and the reaction is carried out for 48 hours. After the reaction is finished, filtering, washing filter cakes by saturated sodium bicarbonate water solution and tetrahydrofuran respectively, and drying to obtain COF-Q-N with the conversion rate of 45%.

The COF-Q-N is dispersed in 12mol/L hydrochloric acid and 12mol/L sodium hydroxide aqueous solution in turn at normal temperature, the soaking time is 24 hours, then the filter cake is filtered, the filter cake is washed by water and tetrahydrofuran respectively, and the filter cake is characterized by a Fourier transform infrared spectrometer and a powder X-ray diffractometer after being dried, and the result shows that the infrared spectrogram and the X-ray diffractogram are almost unchanged before and after being soaked in strong acid and strong alkali solution, thus indicating that the COF-Q-N has better chemical stability.

Example 6

1,3, 5-tris (2-formylpyridin-5-yl) benzene (11.79 mg,0.03 mmol) and 1, 4-phenylenediamine (4.87 mg,0.045 mmol) were added to an ampoule, and then 1mL of a mixed solvent of 1,3, 5-mesitylene and ethanol (volume ratio: 2:1) was added thereto, followed by ultrasonic treatment for 10 minutes to obtain a homogeneous reaction solution, and an aqueous glacial acetic acid solution having a concentration of 6mol/L was used as a catalyst (the ratio of the addition amount of the aqueous glacial acetic acid solution to the total solvent volume: 1:15), and the reaction temperature was controlled to 120℃to react in the ampoule for 72 hours. After the reaction, the mixture was filtered, and the filter cake was washed with tetrahydrofuran and dried to give COF-I-1 in a yield of 91%.

The COF-I-1 and phenylacetylene are uniformly dispersed in toluene solution according to the mass ratio of 1:2, boron trifluoride diethyl etherate and tetrachlorobenzoquinone (the mass ratio of boron trifluoride diethyl etherate, chloranil and phenylacetylene is 1:1:2) are used as catalysts, the reaction temperature is controlled to be 110 ℃, and the reaction is carried out for 48 hours. After the reaction is finished, filtering, washing filter cakes by saturated sodium bicarbonate water solution and tetrahydrofuran respectively, and drying to obtain the COF-Q-1 with the conversion rate of 48%.

The COF-Q-1 is dispersed in 12mol/L hydrochloric acid and 12mol/L sodium hydroxide aqueous solution in turn at normal temperature, the soaking time is 24 hours, then the solution is filtered, filter cakes are respectively washed by water and tetrahydrofuran, and the filter cakes are characterized by a Fourier transform infrared spectrometer and a powder X-ray diffractometer after being dried. The infrared spectrum and the X-ray diffraction spectrum of the COF-Q-1 are almost unchanged before and after soaking in strong acid and strong alkali solutions, which shows that the COF-Q-1 has better chemical stability.

Example 7

1,3, 5-tris (2-formylpyridin-5-yl) benzene (11.79 mg,0.03 mmol) and 4,4' -diaminobiphenyl (8.29 mg,0.045 mmol) were added to an ampoule, and then 1mL of a mixed solvent of 1,3, 5-mesitylene and ethanol (volume ratio: 2:1) was added thereto, followed by ultrasonic treatment for 10 minutes to obtain a homogeneous reaction solution, and an aqueous glacial acetic acid solution having a concentration of 6mol/L was used as a catalyst (the ratio of the addition amount of the aqueous glacial acetic acid solution to the total solvent volume: 1:15), and the reaction temperature was controlled to 120℃to react in the ampoule for 72 hours. After the reaction, the mixture was filtered, and the filter cake was washed with tetrahydrofuran and dried to give COF-I-2 in a yield of 91%.

The COF-I-2 and phenylacetylene are uniformly dispersed in toluene solution according to the mass ratio of 1:2, boron trifluoride diethyl etherate and tetrachlorobenzoquinone (the mass ratio of boron trifluoride diethyl etherate, chloranil and phenylacetylene is 1:1:2) are used as catalysts, the reaction temperature is controlled to be 110 ℃, and the reaction is carried out for 48 hours. After the reaction is finished, filtering, washing filter cakes by saturated sodium bicarbonate water solution and tetrahydrofuran respectively, and drying to obtain COF-Q-2, wherein the conversion rate is 48%.

The COF-Q-2 is dispersed in 12mol/L hydrochloric acid and 12mol/L sodium hydroxide aqueous solution in turn at normal temperature, the soaking time is 24 hours, then the solution is filtered, filter cakes are respectively washed by water and tetrahydrofuran, and the filter cakes are characterized by a Fourier transform infrared spectrometer and a powder X-ray diffractometer after being dried. The infrared spectrum and the X-ray diffraction spectrum of the COF-Q-2 are almost unchanged before and after soaking in strong acid and strong alkali solutions, which shows that the COF-Q-2 has better chemical stability.

Example 8

1,3, 5-tris (2-formylpyridin-5-yl) benzene (11.79 mg,0.03 mmol) and 1,3, 5-tris (4-aminophenyl) benzene (10.53 mg,0.03 mmol) were added to the ampoule, and then 1mL of a mixed solvent of 1,3, 5-mesitylene and ethanol (volume ratio: 2:1) was added thereto, followed by sonication for 10 minutes to obtain a homogeneous reaction solution, and an aqueous solution of glacial acetic acid having a concentration of 6mol/L was used as a catalyst (the ratio of the addition amount of the aqueous solution of glacial acetic acid to the volume of the total solvent: 1:15), and the reaction temperature was controlled to 120℃to react in the ampoule for 72 hours. After the reaction, the mixture was filtered, and the filter cake was washed with tetrahydrofuran and dried to give COF-I-C in a yield of 91%.

The COF-I-C and phenylacetylene are uniformly dispersed in toluene solution according to the mass ratio of 1:2, boron trifluoride diethyl etherate and tetrachlorobenzoquinone (the mass ratio of boron trifluoride diethyl etherate, chloranil and phenylacetylene is 1:1:2) are used as catalysts, the reaction temperature is controlled to be 110 ℃, and the reaction is carried out for 48 hours. After the reaction is finished, filtering, washing filter cakes by saturated sodium bicarbonate water solution and tetrahydrofuran respectively, and drying to obtain COF-Q-C with the conversion rate of 48%.

The COF-Q-C is dispersed in 12mol/L hydrochloric acid and 12mol/L sodium hydroxide aqueous solution in turn at normal temperature, the soaking time is 24 hours, then the solution is filtered, filter cakes are respectively washed by water and tetrahydrofuran, and the filter cakes are characterized by a Fourier transform infrared spectrometer and a powder X-ray diffractometer after being dried. The infrared spectrum and the X-ray diffraction spectrum of the COF-Q-C are almost unchanged before and after soaking in strong acid and strong alkali solutions, which shows that the COF-Q-C has better chemical stability.

Example 9

The COF-Q-N prepared in example 1 was uniformly dispersed in acetonitrile solution of cuprous iodide, the ratio of the amount of (N≡N) -ligand in the quinolinyl covalent organic framework to the amount of cuprous iodide was 2:1, the reaction temperature was controlled at 120℃and the stirring speed was 300rpm for 24 hours. Filtering after the reaction is finished, washing a filter cake by acetonitrile, and drying to obtain Cu@COF-Q-N with a metal loading amount of 40%.

Cu@COF-Q-N is dispersed in 12mol/L hydrochloric acid and 12mol/L sodium hydroxide aqueous solution in turn at normal temperature, soaking time is 24 hours, then filtering is carried out, filter cakes are respectively washed by water and tetrahydrofuran, a Fourier transform infrared spectrometer and a powder X-ray diffractometer are used for characterization after drying, and the infrared spectrogram and the X-ray diffractometer are almost unchanged before and after soaking by strong acid and strong alkali, so that the Cu@COF-Q-N keeps the original topological structure and pore canal size and has good chemical stability.

Example 10

The COF-Q-C prepared in example 8 was uniformly dispersed in acetonitrile solution of palladium chloride, the ratio of the amount of (N≡N) -ligand in the quinolinyl covalent organic framework to the amount of the substance of palladium chloride was 10:1, the reaction temperature was controlled to 80℃and the stirring speed was 300rpm for 12 hours. After the reaction is finished, filtering, washing a filter cake by acetonitrile, and drying to obtain Pd@COF-Q-C, wherein the metal loading amount is 10%.

Pd@COF-Q-C is dispersed in 12mol/L hydrochloric acid and 12mol/L sodium hydroxide aqueous solution in turn at normal temperature, soaking time is 24 hours, then filtering is carried out, filter cakes are respectively washed by water and tetrahydrofuran, a Fourier transform infrared spectrometer and a powder X-ray diffractometer are used for characterization after drying, and the infrared spectrogram and the X-ray diffractometer are almost unchanged before and after soaking by strong acid and strong alkali, which indicates that Pd@COF-Q-C keeps the original topological structure and pore channel size and has good chemical stability.

Example 11

The COF-Q-1 prepared in example 6 was uniformly dispersed in acetonitrile solution of platinum chloride, the ratio of the amount of (N≡N) -ligand in the quinolinyl covalent organic framework to the amount of the substance of platinum chloride was 20:1, the reaction temperature was controlled to 120℃and the stirring speed was 300rpm for 24 hours. Filtering after the reaction is finished, washing a filter cake by acetonitrile, and drying to obtain Pt@COF-Q-1 with 5% metal loading.

Dispersing Pt@COF-Q-1 in 12mol/L hydrochloric acid and 12mol/L sodium hydroxide aqueous solution in turn at normal temperature for 24 hours, filtering, washing filter cakes with water and tetrahydrofuran respectively, drying, and characterizing by a Fourier transform infrared spectrometer and a powder X-ray diffractometer, wherein the infrared spectrogram and the X-ray diffractometer are almost unchanged before and after soaking with strong acid and strong alkali, which indicates that the Pt@COF-Q-1 keeps the original topological structure and pore channel size and has good chemical stability.

Example 12

The COF-Q-2 prepared in example 7 was uniformly dispersed in acetonitrile solution of nickel chloride, the ratio of the amount of (N≡N) -ligand in the quinolinyl covalent organic framework to the amount of the substance of nickel chloride was 2:3, the reaction temperature was controlled at 120℃and the stirring speed was 300rpm for 24 hours. Filtering after the reaction is finished, washing a filter cake by acetonitrile, and drying to obtain the Ni@COF-Q-2 with the metal loading of 51%.

Ni@COF-Q-2 is dispersed in 12mol/L hydrochloric acid and 12mol/L sodium hydroxide aqueous solution in turn at normal temperature, soaking time is 24 hours, then filtering is carried out, filter cakes are respectively washed by water and tetrahydrofuran, a Fourier transform infrared spectrometer and a powder X-ray diffractometer are used for characterization after drying, and the infrared spectrogram and the X-ray diffractometer are almost unchanged before and after soaking by strong acid and strong alkali, which indicates that the Ni@COF-Q-2 keeps the original topological structure and pore canal size and has good chemical stability.

Example 13

The COF-Q-C prepared in example 8 was uniformly dispersed in acetonitrile solution of platinous chloride, the ratio of the amount of (N≡N) -ligand in the quinolinyl covalent organic framework to the amount of platinous chloride was 200:1, the reaction temperature was controlled at 120℃and the stirring speed was 300rpm for 12 hours. Filtering after the reaction is finished, washing a filter cake by acetonitrile, and drying to obtain Pt@COF-Q-C, wherein the metal loading amount is 0.5%.

Dispersing Pt@COF-Q-C in 12mol/L hydrochloric acid and 12mol/L sodium hydroxide aqueous solution in turn at normal temperature for 24 hours, filtering, washing filter cakes with water and tetrahydrofuran respectively, drying, and characterizing by a Fourier transform infrared spectrometer and a powder X-ray diffractometer, wherein the infrared spectrogram and the X-ray diffractometer are almost unchanged before and after soaking with strong acid and strong alkali, which indicates that the Pt@COF-Q-C maintains the original topological structure and pore canal size and has good chemical stability.

Example 14

The COF-Q-N prepared in example 1 was uniformly dispersed in acetonitrile solution of platinous chloride, the ratio of the amount of (N≡N) -ligand in the quinolinyl covalent organic framework to the amount of platinous chloride was 200:1, the reaction temperature was controlled at 120℃and the stirring speed was 300rpm for 24 hours. Filtering after the reaction is finished, washing a filter cake by acetonitrile, and drying to obtain Pt@COF-Q-N, wherein the metal loading amount is 0.5%.

Dispersing Pt@COF-Q-N in 12mol/L hydrochloric acid and 12mol/L sodium hydroxide aqueous solution in turn at normal temperature for 24 hours, filtering, washing filter cakes with water and tetrahydrofuran respectively, drying, and characterizing by a Fourier transform infrared spectrometer and a powder X-ray diffractometer, wherein the infrared spectrogram and the X-ray diffractometer are almost unchanged before and after soaking with strong acid and strong alkali, which indicates that the Pt@COF-Q-N keeps the original topological structure and pore canal size and has good chemical stability.

At 25℃under nitrogen, 2mg of Pt@COF-Q-N were taken, dispersed in deionized water and transferred to a 10mL photocatalytic special bottle. Ascorbic acid was used as an electron-sacrificial agent at a concentration of 1mmol/mL. The LED lamp with the power of 10W and the wavelength of 450nm is used as a light source, and the illumination time is 10 hours. After the reaction was completed, the gas in the flask was taken, and the hydrogen production amount was 2.22 mmol/(g.h) as measured by gas chromatography. The infrared spectrogram and the X-ray diffraction spectrogram of Pt@COF-Q-N after use are almost unchanged and can be recycled, as shown in FIG. 5. The nitrogen adsorption and desorption curves are shown in FIG. 6, and the results show that Pt@COF-Q-N has a mesoporous structure, and the pore size distribution diagram shows that the pore size of Pt@COF-Q-N is mainly distributed in Consistent with the simulation results. The nitrogen adsorption and desorption curve and pore size distribution after use are shown in figure 7, and the result shows that the mesoporous structure still existsThe original aperture is maintained. The Pt@COF-Q-N maintains the original topological structure and pore canal size in the photocatalysis process, and has good chemical stability.

Example 15

2mg of Pt@COF-Q-N as described in example 14 was dispersed in methanol and transferred to a 10mL photocatalytic-dedicated bottle under nitrogen at 25 ℃. Nitrobenzene was used as the reaction substrate at a concentration of 0.018mmol/mL, ascorbic acid was used as the electron sacrificial agent, and the sacrificial agent concentration was controlled at 1mmol/mL. The LED lamp with the power of 10W and the wavelength of 450nm is used as a light source, and the illumination time is 5 hours. After the reaction was completed, the liquid in the flask was taken, the catalyst was removed by filtration, and the product was analyzed by gas chromatography to obtain aniline in 94% yield. The infrared spectrogram and the X-ray diffraction spectrogram of Pt@COF-Q-N after the photocatalytic hydrogenation reaction are almost unchanged, the Pt@COF-Q-N can be recycled, and the performance is reduced by less than 5% after five times of recycling. The Pt@COF-Q-N maintains the original topological structure and pore canal size in the photocatalysis process, and has good chemical stability.

Example 16

The COF-Q-N prepared in example 1 was uniformly dispersed in an acetonitrile solution of platinous chloride, and the ratio of the amount of (N≡N) -ligand in the quinolinyl covalent organic framework to the amount of platinous chloride was 200:1. The reaction temperature was controlled at 120℃and the stirring speed was 300rpm, followed by reaction for 24 hours. After the reaction is finished, filtering, washing a filter cake by acetonitrile, and drying to obtain Pt@COF-Q-N. The Pt@COF-Q-N obtained is uniformly dispersed in an acetonitrile solution of (2-phenylpyridine) iridium chloride, and the ratio of the amount of (N≡N) -coordination unit in the quinolinyl covalent organic framework to the amount of (2-phenylpyridine) iridium chloride is 10:1. The reaction temperature was 80℃and the stirring speed was 300rpm for 12 hours. Filtering after the reaction is finished, washing a filter cake by acetonitrile, and drying to obtain (Ir+Pt) @ COF-Q-N, wherein the Pt metal loading amount is 0.5%; the Ir metal loading was 10%. Wherein Ir groups can be used as photosensitizers to enhance the absorption of light by the organic framework.

2mg (Ir+Pt) @ COF-Q-N was dispersed in methanol and transferred to a 10mL photocatalytic dedicated bottle under nitrogen at 25 ℃. Nitrobenzene was used as the reaction substrate at a concentration of 0.018mmol/mL and ascorbic acid was used as the electron sacrificial agent at a concentration of 1mmol/mL. The LED lamp with the power of 10W and the wavelength of 450nm is used as a light source, and the illumination time is 2 hours. After the reaction, the liquid in the bottle was taken, the catalyst was removed by filtration, and the product analysis was performed by gas chromatography to obtain aniline with a yield of 93%. The addition of Ir metal enhances the photocatalytic hydrogenation performance of (Ir+Pt) @ COF-Q-N, and can be recycled. It is shown that (Ir+Pt) @ COF-Q-N has a good stabilizing effect on Ir and Pt.

Comparative example 1 was used

The COF-I-N prepared in example 1 was uniformly dispersed in acetonitrile solution of platinous chloride, the ratio of the amount of (N≡N) -ligand in the quinolinyl covalent organic framework to the amount of platinous chloride was 200:1, the reaction temperature was controlled at 120℃and the stirring speed was 300rpm for 24 hours. Filtering after the reaction is finished, washing a filter cake by acetonitrile, and drying to obtain Pt@COF-I-N with metal loading of 0.5%.

Dispersing Pt@COF-I-N in 6mol/L hydrochloric acid and 6mol/L sodium hydroxide aqueous solution in turn at normal temperature for 12 hours, filtering, washing filter cakes with water and tetrahydrofuran respectively, drying, and characterizing by a Fourier transform infrared spectrometer and a powder X-ray diffractometer, wherein the result is shown in figures 3-4, the infrared spectrogram and the X-ray diffractogram are obviously changed after strong acid and strong alkali are soaked, and the spectral peak of the X-ray diffractogram disappears at 2 theta = 4.1 degrees, which indicates that the crystallinity of Pt@COF-I-N disappears and the chemical stability is poor.

Comparative example 2 was used

2mg of Pt@COF-I-N as described in application comparative example 1 was dispersed in deionized water and transferred to a 10mL photocatalytic-dedicated bottle under nitrogen atmosphere at 25 ℃. Ascorbic acid was used as an electron-sacrificial agent at a concentration of 1mmol/mL. An LED lamp with the wavelength of 450nm and the power of 10W is used as a light source, and the illumination time is 10 hours. After the reaction was completed, the gas in the flask was taken, and the hydrogen production amount was 2.15 mmol/(g.h) as measured by gas chromatography. The infrared spectrum and the X-ray diffraction spectrum of pt@cof-I-N after use were both changed, the spectrum peak of the X-ray diffraction spectrum disappeared at 2θ=4.1°, and the recyclability was poor, as shown in fig. 8. The nitrogen adsorption and desorption curves and pore size distribution are shown in FIG. 9, and the results are shown The Pt@COF-I-N has a mesoporous structure, and a pore size distribution diagram shows that the Pt@COF-I-N pore size isConsistent with the analog values. After use, the nitrogen adsorption and desorption curve and the pore size distribution are shown in fig. 10, and the result shows that the mesoporous structure is lost, the pore size distribution is irregular, the numerical value is larger, and most of the numerical values are gaps between the collapsed fragments of the framework. The Pt@COF-I-N is poor in stability in the photocatalysis process.

Comparative example 3 was used

2mg of Pt@COF-I-N as described in application comparative example 1 was dispersed in methanol and transferred to a 10mL photocatalytic dedicated bottle under nitrogen at 25℃with a Pt metal loading of 0.5%. Nitrobenzene was the substrate at a concentration of 0.018mmol/mL and ascorbic acid was the electron sacrificial agent at a concentration of 1mmol/mL. An LED lamp with the wavelength of 450nm and the power of 10W is used as a light source, and the illumination time is 5 hours. After the reaction, the liquid in the bottle was taken, the catalyst was removed by filtration, and the product analysis was performed by gas chromatography to obtain aniline with a yield of 90%. The infrared spectrogram and the X-ray diffraction spectrogram of the Pt@COF-I-N after the photocatalytic hydrogenation reaction are changed, the spectrum peak of the X-ray diffraction spectrogram at 2 theta=4.1 DEG disappears, and the recycling property is poor, which indicates that the Pt@COF-I-N has poor stability in the photocatalytic process.

Comparative example 4 was used

2mg of COF-Q-N was dispersed in deionized water at 25℃under nitrogen, and transferred to a 10mL photocatalytic dedicated bottle. Ascorbic acid is used as an electron sacrificial agent, and the concentration of the sacrificial agent is controlled to be 1mmol/mL. An LED lamp with the wavelength of 450nm and the power of 10W is used as a light source, and the illumination time is 10 hours. After the completion of the reaction, the gas in the flask was taken, and the hydrogen production amount was measured by gas chromatography and found to be 0.001 mmol/(g.h). Therefore, the porous crystalline organic frame without the supported metal catalyst has little photocatalytic hydrogen production effect under the irradiation of visible light.

Comparative example 5 was used

1,3, 5-tris (p-formylphenyl) benzene was used in place of 1,3, 5-tris (2-formylpyridin-5-yl) benzene, with the other conditions consistent with the synthesis conditions of Pt@COF-Q-N, to construct a quinolinyl covalent organic framework containing only a single N coordination moiety, and designated Pt@COF'. Under nitrogen atmosphere at 25 ℃, 2mg of pt@cof' was dispersed in deionized water and transferred to a 10mL photocatalytic dedicated bottle, wherein the Pt metal loading was 0.5%. Ascorbic acid was used as an electron-sacrificial agent at a concentration of 1mmol/mL. An LED lamp with the wavelength of 450nm and the power of 10W is used as a light source, and the illumination time is 10 hours. After the reaction was completed, the gas in the flask was taken, and the hydrogen production amount was 2.15 mmol/(g.h) as measured by gas chromatography. The circulation experiment shows that the photocatalytic hydrogen production performance is reduced by 8% after the Pt@COF' is used for five times. The recycling performance of Pt@COF' of a single N coordination element is not as good as that of Pt@COF-Q-N rich in (N≡N) -coordination elements.

Comparative example 6 was used

1,3, 5-tris (p-formylphenyl) benzene was used in place of 1,3, 5-tris (2-formylpyridin-5-yl) benzene, the other conditions being consistent with the synthesis conditions of (Ir+Pt) @ COF-Q-N, a quinolinyl covalent organic framework containing only a single N-coordination moiety was constructed and named (Ir+Pt) @ COF'. Under nitrogen atmosphere at 25 ℃, 2mg (ir+pt) @ COF' was dispersed in methanol and transferred to a 10mL photocatalytic dedicated bottle, wherein the Ir metal loading was 1% and the Pt metal loading was 0.5%. Nitrobenzene was used as the reaction substrate at a concentration of 0.018mmol/mL and ascorbic acid was used as the electron sacrificial agent at a concentration of 1mmol/mL. The LED lamp with the power of 10W and the wavelength of 450nm is used as a light source, and the illumination time is 2 hours. After the reaction is finished, taking the liquid in the bottle, filtering to remove the catalyst, and analyzing the product by gas chromatography to obtain the aniline with the yield of 35 percent and poor photocatalytic hydrogenation effect. In connection with example 16, it is demonstrated that the single N-coordination unit (Ir+Pt) @ COF' does not stabilize Ir and Pt well.

The porous crystalline organic framework rich in (N-N) -coordination units and having high chemical stability has novel structure, simple preparation process, low cost and easy obtainment, and compared with an imine bond framework, the crystalline framework of the quinolyl covalent organic framework in strong acid or alkali solution is maintained, so that the porous crystalline organic framework has good chemical stability. The quinolinyl porous crystalline organic framework rich in (N-N) -coordination units has stronger coordination capacity than that of a quinolinyl porous crystalline organic framework constructed by a single N-coordination unit, improves the anchoring capacity of a covalent organic framework to a metal catalytic center, can enhance the catalytic activity of the metal center, and can be used as an ideal metal catalyst carrier. The porous crystalline organic framework containing quinoline groups and rich in (N-N) -coordination elements can be used for photocatalytic hydrogen production and photocatalytic hydrogenation after being loaded with Pt metal catalysts, and has good chemical stability and recycling property.

In view of the foregoing, it will be appreciated that the invention includes but is not limited to the foregoing embodiments, any equivalent or partial modification made within the spirit and principles of the invention.

Claims

1. A porous crystalline quinolinyl organic framework rich in (N≡N) -coordination motifs is characterized in that: the structural formula is as follows:

wherein, the liquid crystal display device comprises a liquid crystal display device,is->

2. A preparation method of a porous crystalline quinolyl organic framework rich in (N≡N) -coordination motifs is characterized by comprising the following steps: the method comprises the following steps:

3. The method of preparing a porous crystalline quinolinyl organic framework rich in (N) -coordination moieties of claim 2, characterized by: in the step (2), the concentration of the glacial acetic acid aqueous solution is 3-9 mol/L, and the volume ratio of the glacial acetic acid aqueous solution to the mixed solvent in the step (1) is 1:10-1:20.

4. The method of preparing a porous crystalline quinolinyl organic framework rich in (N) -coordination moieties of claim 2, characterized by: in the step (3), the molar ratio of the imine bond framework compound to the aromatic alkyne is 1:1-1:3; the molar ratio of boron trifluoride diethyl etherate, tetrachlorobenzoquinone and aromatic alkyne is 1:1:2-1:1:10.

5. The method for preparing a porous crystalline quinolinyl organic framework rich in (N≡N) -ligand moieties of claim 4, wherein the method comprises the steps of: in the step (3), the aromatic alkyne is phenylacetylene, p-nitroacetylene, 4-ethynyl-alpha, alpha-benzotrifluoride, 4-dimethylaminophenylacetylene or 4-tert-butylphenylacetylene.

6. Use of the (N-N) -ligand-rich porous crystalline quinolinyl organic framework of claim 1, characterized by: the porous crystalline quinolinyl organic frameworks are used as metal catalyst supports.

7. Use of a porous crystalline quinolinyl organic framework rich in (N-coordination) motifs as in claim 6, characterized in that: uniformly dispersing the porous crystalline quinolyl organic framework in acetonitrile solution of metal salt, controlling the reaction temperature to be 60-120 ℃, and stirring for reaction for 5-20 hours; after the reaction is finished, filtering, washing and drying to obtain the metal-loaded quinolyl covalent organic framework.

8. Use of a porous crystalline quinolinyl organic framework rich in (N-coordination) motifs as in claim 7, characterized by: the molar ratio of the porous crystalline quinolyl organic framework to the metal salt is 200:1-1:3; the metal includes one or more of Cu, pt, ir, pd, ni, co and Ru.

9. Use of a porous crystalline quinolinyl organic framework rich in (N-coordination) motifs as in claim 7, characterized by: the metal-loaded quinolinyl covalent organic framework is used as a catalyst for photocatalytic hydrogen production.

10. Use of a porous crystalline quinolinyl organic framework rich in (N-coordination) motifs as in claim 7, characterized by: the metal-loaded quinolinyl covalent organic framework is used as a catalyst for photocatalytic hydrogenation.