阅读说明：本技术 一种基于咪唑并[1,2-a]吡啶连接的共价有机框架材料及其合成方法 (Covalent organic framework material based on imidazo [1,2-a ] pyridine connection and synthetic method thereof ) 是由 王为 丁三元 刘姣 杨侗 于 2020-11-20 设计创作，主要内容包括：本发明公开了一类咪唑并[1,2-a]吡啶连接的共价有机框架材料(LZU-561,LZU-563)的合成方法。以易得且可大量制备的化合物(1,3,5-三(3,3",3”’-三氟-4’,4”,4”’-三(对甲酰基苯基)苯,1,3,5-三(4-异腈基苯基)苯和2-氨基吡啶或2-氨基-4-氯吡啶为单体,在催化剂对甲基苯磺酸一水合物的溶剂热条件下,构筑了稳定的咪唑并[1,2-a]吡啶连接的COFs。具有密度小,比表面积大,通过基于组分数目的优势,其中的组分醛和异腈作为构筑单元形成COFs的拓扑结构,另外的一个组分吡啶胺作为功能单元引入功能,吡啶胺也参与咪唑并[1,2-a]吡啶连接方式的形成。(The invention discloses a synthetic method of a covalent organic framework material (LZU-561, LZU-563) connected by imidazo [1,2-a ] pyridine. The compounds (1,3, 5-tri (3,3 ' -trifluoro-4 ', 4' -tri (p-formylphenyl) benzene, 1,3, 5-tri (4-isonitrile phenyl) benzene and 2-aminopyridine or 2-amino-4-chloropyridine) which are easy to obtain and can be prepared in large quantity are taken as monomers, under the solvothermal condition of a catalyst p-toluenesulfonic acid monohydrate, stable imidazo [1,2-a ] pyridine-linked COFs are constructed, and the catalyst has the advantages of small density, large specific surface area and component number-based advantages, the components of aldehyde and isonitrile are used as building units to form a topological structure of COFs, the other component of pyridylamine is used as a functional unit to introduce functions, and the pyridylamine also participates in the formation of an imidazo [1,2-a ] pyridine connection mode.)

1. An imidazo [1,2-a ] pyridine linked covalent organic framework material, characterized in that said covalent organic framework material is prepared from 1,3, 5-tris (3,3",3 '" -trifluoro-4', 4 ", 4 '" -tris (p-formylphenyl) benzene, 1,3, 5-tris (4-isonitrile-phenyl) benzene, 2-aminopyridine or 2-amino-4-chloropyridine, p-toluenesulphonic acid monohydrate, and said 1,3, 5-tris (3,3", 3'" -trifluoro-4 ',4 ", 4'" -tris (p-formylphenyl) benzene, 1,3, 5-tris (4-isonitrile-phenyl) benzene, 2-aminopyridine or 2-amino-4-chloropyridine, The molar ratio of p-toluenesulfonic acid monohydrate is 1:0.9 (3-10) to 0.5-1.

2. The covalent organic framework material of claim 1 wherein the molar ratio of 1,3, 5-tris (3,3",3 '" -trifluoro-4 ',4 ", 4 '" -tris (p-formylphenyl) benzene, 1,3, 5-tris (4-isonitrile-phenyl) benzene, 2-aminopyridine or 2-amino-4-chloropyridine to p-toluenesulphonic acid monohydrate is 1:0.9 (3-6): 0.5-1.

3. The method of preparing a covalent organic framework material of claim 1 or 2, comprising the steps of:

(1) adding 1,3, 5-tri (3,3 ' -trifluoro-4 ', 4' -tri (p-formylphenyl) benzene, 1,3, 5-tri (4-isonitrile phenyl) benzene, 2-aminopyridine or 2-amino-4-chloropyridine and p-toluenesulfonic acid monohydrate into a reactor according to a proportion, and sequentially adding an organic solvent;

(2) reacting at high temperature, centrifuging after the reaction is finished, washing, and drying to obtain a solid, namely the covalent organic framework material.

4. The method according to claim 3, wherein the organic solvent used in step (1) is selected from the group consisting of ethanol, mesitylene, n-butanol, and o-dichlorobenzene.

5. The method according to claim 4, wherein the volume ratio of ethanol to mesitylene in step (1) is 1: 3; the volume ratio of n-butanol to o-dichlorobenzene is 2: 3.

6. the method of claim 3, wherein the concentration of 1,3, 5-tris (3,3",3 '" -trifluoro-4 ',4 ", 4 '" -tris (p-formylphenyl) benzene of step (1) is 10-100 μmol/mL.

7. The method according to claim 3, wherein the high temperature and high pressure in step (2) are carried out by heating and reacting through a thick-walled pressure-resistant tube, or by freezing a tube sealing system with liquid nitrogen, then vacuumizing, and sealing the tube opening with flame.

8. The method of claim 3, wherein the reaction temperature in step (2) is 25 ℃ to 180 ℃.

9. The method of claim 3, wherein the reaction time in step (2) is 1d to 15 d.

10. The method according to claim 3, wherein the solvents used in the washing in step (2) are dimethylformamide and ethanol.

Technical Field

The invention belongs to the field of organic synthesis and functional materials (COFs), and particularly relates to an imidazo [1,2-a ] pyridine-linked covalent organic framework material and a synthesis method thereof.

Background

Covalent organic framework materials (COFs) are crystalline porous materials which are connected by pure organic components through covalent bonds, and have the characteristics of light weight, large specific surface area, easy functionalization and the like. Because the directionality, saturation and stability of covalent bonds endow the covalent organic framework with definite connection and stable structure, COFs are gradually used in the fields of gas adsorption/separation/storage, photoelectricity (devices), catalysis and the like.

In recent years, efforts have been made to construct covalent organic framework materials with stable linkages, and great progress has been made in the direct construction of stable COFs by irreversible reactions. Although various stable connection mode COFs have been successfully prepared at present, except that the structure has a certain function so as to realize the application of the COFs, functional groups of the stable connection mode COFs are obtained through post-modification at present, and the post-modification can not enable chemical bonds in the material to be completely converted, so that the functional groups of the post-modified material are further unevenly distributed in the pore channel, and the further application of the COFs is not facilitated. In the face of the problem that stable COFs are not easy to be directly functionalized, a multi-component reaction is adopted to construct the COFs, and the COFs with stable functional groups linked on the side are expected to be simply and directly constructed.

Based on the advantages of multi-component reaction components, the stable COFs connected by imidazo [1,2-a ] pyridine is constructed by utilizing the multi-component reaction participated by isonitrile, namely Groebke-Black burn-Bienayme (GBB) reaction, and the accurate regulation and control of the stable COFs functional structure is realized. Two components are selected as a construction unit, the other component is selected as a functional unit, under the condition that the construction unit is not changed, the functional unit is changed to realize the functionalization of the COFs side chain, and the prepared COFs can be applied to the fields of gas adsorption/separation/storage, photoelectricity (devices), catalysis and the like.

Disclosure of Invention

The invention provides an imidazo [1,2-a ] pyridine-linked covalent organic framework material, which is prepared from 1,3, 5-tri (3,3 '-trifluoro-4', 4 '-tri (p-formylphenyl) benzene, 1,3, 5-tri (4-isonitrile phenyl) benzene, 2-aminopyridine or 2-amino-4-chloropyridine and p-methylbenzenesulfonic acid monohydrate, wherein the 1,3, 5-tri (3, 3' -trifluoro-4 ', 4' -tri (p-formylphenyl) benzene, 1,3, 5-tri (4-isonitrile phenyl) benzene, 2-aminopyridine or 2-amino-4-chloropyridine is, The molar ratio of p-toluenesulfonic acid monohydrate is 1:0.9 (3-10) to 0.5-1.

Preferably, the molar ratio of the 1,3, 5-tri (3,3 ' -trifluoro-4 ', 4' -tri (p-formylphenyl) benzene, 1,3, 5-tri (4-isonitrile phenyl) benzene, 2-aminopyridine or 2-amino-4-chloropyridine to p-toluenesulfonic acid monohydrate is 1:0.9 (3-6): 0.5-1.

The invention also provides a preparation method of the covalent organic framework material, which comprises the following steps:

(1) adding 1,3, 5-tri (3,3 ' -trifluoro-4 ', 4' -tri (p-formylphenyl) benzene, 1,3, 5-tri (4-isonitrile phenyl) benzene, 2-aminopyridine or 2-amino-4-chloropyridine and p-toluenesulfonic acid monohydrate into a reactor according to a proportion, and sequentially adding an organic solvent;

(2) reacting at high temperature, centrifuging after the reaction is finished, washing, and drying to obtain a solid, namely the covalent organic framework material.

Preferably, the organic solvent in step (1) may be ethanol and mesitylene or n-butanol and o-dichlorobenzene.

Preferably, the volume ratio of the ethanol to the mesitylene in the step (1) is 1: 3; the volume ratio of n-butanol to o-dichlorobenzene is 2: 3.

preferably, the concentration of 1,3, 5-tris (3,3", 3" ' -trifluoro-4 ',4 ", 4" ' -tris (p-formylphenyl) benzene in step (1) is 10-100 μmol/mL.

Preferably, the high temperature and high pressure in step (2) are heated and reacted through a thick-wall pressure-resistant pipe, or the pipe sealing system is frozen by liquid nitrogen and then vacuumized, and the pipe orifice is sealed by flame and then reacted.

Preferably, the reaction temperature in step (2) is 25 ℃ to 180 ℃.

Preferably, the reaction time in step (2) is 1d-15 d.

Preferably, the solvents used for the washing in step (2) are dimethylformamide and ethanol.

The invention introduces multicomponent reaction participated by isonitrile into the synthesis of COFs, provides a new way for the precise construction of stable functional COFs, realizes the industrial application of a covalent organic framework, and provides a synthetic method of an imidazole [1,2-a ] pyridine-connected ultrastable covalent organic framework material (LZU-561).

Preferably, the reaction vessel of the present invention is a thick-walled pressure-resistant tube or ampoule.

The invention has the beneficial effects that: the covalent organic framework material connected by the imidazo [1,2-a ] pyridine obtained by the synthesis method has the characteristics of small density (only containing carbon, hydrogen, nitrogen and fluorine elements) and large specific surface area. And the inventor can form a topological structure of COFs by selecting two components of aldehyde and isonitrile as building units based on the advantages of component numbers, and the other component of pyridylamine is used as a functional unit to introduce functions, and meanwhile, the pyridylamine also participates in the formation of an imidazo [1,2-a ] pyridine connection mode. The covalent organic framework material prepared by the invention has a long-range ordered two-dimensional hexagonal structure and a regular ordered pore channel, and has excellent thermal stability and chemical stability. The material has the advantages of simple synthetic route, large preparation capacity and large specific surface area, and the type and the number of substituent groups on pyridylamine can be changed in the structure, so that different functional groups can be introduced into the COFs material.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention and not to limit the invention. In the drawings:

FIG. 1 is a powder X-ray diffraction pattern of LZU-561 synthesized by the present invention and a raw material.

FIG. 2 is a solid nuclear magnetic spectrum of LZU-561 synthesized by the present invention.

FIG. 3 is a Fourier infrared spectrum of LZU-561 and starting materials synthesized by the present invention.

FIG. 4 is a nitrogen desorption isotherm and pore size distribution curve of the LZU-561 synthesized by the present invention.

FIG. 5 is a thermogravimetric analysis curve of the synthesized LZU-561 of the present invention.

FIG. 6 is a powder X-ray diffraction pattern of LZU-563 synthesized by the present invention and a starting material.

FIG. 7 is a solid nuclear magnetic spectrum of LZU-563 synthesized in accordance with the present invention.

FIG. 8 is a Fourier infrared spectrum of LZU-563 and starting materials synthesized by the present invention.

FIG. 9 is a nitrogen sorption desorption isotherm and pore size distribution curve for the LZU-563 synthesized in accordance with the present invention.

FIG. 10 is a thermogravimetric analysis curve of the LZU-563 synthesized in accordance with the present invention.

FIG. 11 is an X-ray diffraction pattern of a powder of LZU-563 synthesized in accordance with the present invention after solvent treatment.

Detailed Description

The protection scope of the present invention is described below with reference to specific embodiments, but it should be understood that the preferred embodiments described herein are only for illustrating and explaining the technical solutions of the present invention, and are not intended to limit the protection scope of the present invention.

The precursors used for synthesizing the material are all products available in the market.

EXAMPLE I Synthesis and Property Studies of imidazo [1,2-a ] pyridine-linked two-dimensional covalent organic framework Material LZU-561

1,3, 5-tris (3,3 ' -trifluoro-4 ', 4' -tris (p-formylphenyl) benzene (22.5mg,0.050mmol), 2-aminopyridine (17mg,0.18mmol), 1,3, 5-tris (4-isonitrile-phenyl) benzene (17.6mg,0.046mmol), and p-toluenesulphonic acid monohydrate (7mg,0.036mmol) as a catalyst were added to a 10mL ampoule, ethanol (0.10mL) and mesitylene (0.30 mL) were added as solvents, the ampoule was placed on a vacuum adsorption line, after the solvent was frozen by liquid nitrogen, the ampoule was sealed with a flame gun after the pressure in the ampoule was evacuated to 0mbar, the ampoule was warmed to room temperature, the ampoule was placed in an oven, warmed to 120 ℃ and left to stand for 5d to obtain a yellowish brown solid, the solid material therein was returned to room temperature by extracting DMF and ethanol, respectively, for 24h, unreacted monomers and products having a lower degree of polymerization are removed. Drying at 80 ℃ for 8h gave LZU-561 as a yellow-brown powder (36.8mg, 69%).

Referring to FIG. 1, by comparing the powder X-ray diffraction patterns of LZU-561 and the starting material, wherein the curve shown in 1a corresponds to 2-aminopyridine, the curve shown in 2 corresponds to 1,3, 5-tris (3,3 ' -trifluoro-4 ', 4' -tris (p-formylphenyl) benzene, and the curve shown in 3 corresponds to 1,3, 5-tris (4-isonitrile phenyl) benzene, it was found that a new crystalline form of material LZU-561 was successfully synthesized by the method of the present invention.

As shown in FIG. 2, it is understood that the presence of signals of 122ppm and 142ppm in the solid nuclear magnetic spectrum of LZU-561 suggested that the imidazo [1,2-a ] pyridine structure was formed by condensation reaction between the monomers.

The Fourier infrared spectrum of the LZU-561 synthesized by the invention and the raw material is shown in figure 3, the curve shown by the LZU-561 is corresponding to the LZU-561, 1a is corresponding to the infrared absorption curve of 2-aminopyridine, 2 is corresponding to the infrared absorption curve of 1,3, 5-tri (3,3 ' -trifluoro-4 ', 4' -tri (p-formylphenyl) benzene, and 3 is corresponding to the infrared absorption curve of 1,3, 5-tri (4-isonitrile phenyl) benzene, which proves that the covalent organic framework material connected by imidazo [1,2-a ] pyridine is obtained.

As shown in FIG. 4, the nitrogen adsorption-desorption curve (left) and the pore size distribution curve (right) of LZU-561 indicate that the material has a large specific surface area (BET surface area of 321 m)²/g) and pore structure

As shown in fig. 5, it was found by thermogravimetric analysis that LZU-561 was stable to at least 300 ℃ under nitrogen atmosphere without significant decomposition.

EXAMPLE two Synthesis and Property Studies of imidazo [1,2-a ] pyridine-linked two-dimensional covalent organic framework Material LZU-563

1,3, 5-tris (3,3 ' -trifluoro-4 ', 4' -tris (p-formylphenyl) benzene (11.3mg,0.025mmol), 2-amino-4-chloropyridine (19.5mg,0.151mmol), 1,3, 5-tris (4-isonitrile-phenyl) benzene (9.7mg,0.025mmol) and the catalyst p-toluenesulfonic acid monohydrate (3.5mg,0.018mmol) were added to a 10mL ampoule, n-butanol (0.40mL) and o-dichlorobenzene (0.60mL) were added as solvents, the ampoule was attached to a vacuum adsorption line, after the solvent was frozen by liquid nitrogen, the ampoule was sealed with a flame gun after the pressure in the ampoule was pumped to 0mbar, the reaction was warmed to room temperature, the ampoule was placed in an oven, warmed to 120 ℃ and left to stand for 5d to obtain a yellow solid, the reaction was returned to room temperature, the solid material was extracted with DMF and ethanol for 24h, respectively, to remove unreacted monomers and products with lower degree of polymerization. Drying at 80 ℃ for 8h gave LZU-563 as a yellow powder (20.3mg, 69%).

As shown in fig. 6, by comparing the powder X-ray diffraction patterns of LZU-563 with that of the starting material, it was found that a new crystalline material was successfully synthesized by the method of the present invention. Wherein 1c in FIG. 6 corresponds to 2-amino-4-chloropyridine, 2 in FIG. 6 corresponds to 1,3, 5-tris (3,3 ' -trifluoro-4 ', 4' -tris (p-formylphenyl) benzene, and 3 in FIG. 6 corresponds to 1,3, 5-tris (4-isonitrile phenyl) benzene;

referring to FIG. 7, the presence of 121ppm and 141ppm signals in the solid NMR spectrum of LZU-563 indicates that the imidazo [1,2-a ] pyridine structure is formed by condensation reaction between the monomers.

The fourier infrared spectra of the LZU-563 and the starting material synthesized in the present invention are shown in fig. 8, where 1c corresponds to 2-amino-4-chloropyridine, 2 corresponds to 1,3, 5-tris (3,3", 3" ' -trifluoro-4 ',4 ", 4" ' -tris (p-formylphenyl) benzene, and 3 corresponds to 1,3, 5-tris (4-isonitrile phenyl) benzene, confirming that we have obtained an imidazo [1,2-a ] pyridine linked covalent organic framework material.

As shown in FIG. 9, the nitrogen desorption curve (left) and the pore size distribution curve (right) of LZU-563 show that the material has a large specific surface area (BET surface area of 554 m)²/g) and pore structure

As shown in fig. 10, it was found by thermogravimetric analysis that LZU-563 was stable to at least 300 ℃ under nitrogen atmosphere without significant decomposition.

As shown in fig. 11, LZU-563 has excellent chemical stability as found by a powder X-ray diffraction pattern and a nitrogen adsorption and desorption curve. Good ordered structure and pore structure are maintained in water, DMF,9M HCl and 9M NaOH.

In summary, the first embodiment and the second embodiment of the present invention respectively prepare different two-dimensional covalent organic framework materials, which indicates that the type and number of the substituent groups on pyridylamine can be changed, and different functional groups can be introduced into COFs materials, thereby preparing covalent organic framework materials with different functions. The material prepared by the invention has the characteristics of small density (only containing carbon, hydrogen, nitrogen and fluorine elements) and large specific surface area. And the inventor can form a topological structure of COFs by selecting two components of aldehyde and isonitrile as building units based on the advantages of component numbers, and the other component of pyridylamine is used as a functional unit to introduce functions, and meanwhile, the pyridylamine also participates in the formation of an imidazo [1,2-a ] pyridine connection mode. The covalent organic framework material prepared by the invention has a long-range ordered two-dimensional hexagonal structure and a regular ordered pore channel, and has excellent thermal stability and chemical stability. The material has the advantages of simple synthetic route, large preparation capacity and large specific surface area, and the type and the number of substituent groups on pyridylamine can be changed in the structure, so that different functional groups can be introduced into the COFs material.