CN107857881B

CN107857881B - Benzoxazole-linked covalent organic framework material and synthesis method thereof

Info

Publication number: CN107857881B
Application number: CN201710986362.6A
Authority: CN
Inventors: 王为; 魏丕峰; 丁三元
Original assignee: Lanzhou University
Current assignee: Lanzhou University
Priority date: 2017-10-20
Filing date: 2017-10-20
Publication date: 2020-09-11
Anticipated expiration: 2037-10-20
Also published as: CN107857881A

Abstract

The invention discloses a covalent organic framework material connected by benzoxazole and a synthetic method thereof. The synthetic method of the benzoxazole-linked covalent organic framework material comprises the following steps: 2,4, 6-tri (4-formylphenyl) -1,3, 5-triazine or 1,3,6, 8-tetra (4-formylphenyl) pyrene and 2, 5-dihydroxy-1, 4-p-phenylenediamine hydrochloride are uniformly mixed in an organic solvent and react under the catalysis of a weak alkaline catalyst to obtain the covalent organic framework material. The benzoxazole-linked covalent organic framework material prepared by the invention has a large specific surface area and a regular pore structure, and is good in stability.

Description

Benzoxazole-linked covalent organic framework material and synthesis method thereof

Technical Field

The invention relates to the field of organic synthesis and functional materials, in particular to a covalent organic framework material connected by benzoxazole and a synthesis method thereof.

Background

The materials change the world, and in the development process of the modern society, the materials are indispensable components. In all aspects, there is a wide range of applications, particularly for porous materials, which, because of their good properties, are of great importance. In the application process, the stability of the material is of great importance, the development prospect of the material is directly influenced, and the development of the material is also restricted. In response to such a situation, it is of great importance to develop a stable material.

The covalent organic framework material is a new molecular sieve material, has attracted extensive attention in recent years, and has been primarily applied in the fields of gas adsorption/separation/storage, drug sustained release, photoelectricity (devices), catalysis and the like. The covalent organic framework material has various synthetic precursors, and the structure and the performance of the covalent organic framework material can be regulated and controlled by changing the precursors; meanwhile, the catalyst has large specific surface area and ordered pore channels, so that the reaction raw materials and products are conveniently conveyed; however, the stability of the covalent organic framework material limits its application. Therefore, the synthesis of stable covalent organic framework materials is very important, and the real function of the covalent organic framework materials can be realized.

Disclosure of Invention

In order to solve the problems in the prior art, the invention provides a covalent organic framework material connected with benzoxazole and a synthesis method thereof.

Specifically, the invention provides a synthetic method of a benzoxazole-linked covalent organic framework material

Which comprises the following steps:

2,4, 6-tri (4-formylphenyl) -1,3, 5-triazine or 1,3,6, 8-tetra (4-formylphenyl) pyrene and 2, 5-dihydroxy-1, 4-p-phenylenediamine hydrochloride are uniformly mixed in an organic solvent and react under the catalysis of a weak alkaline catalyst to obtain the covalent organic framework material.

For example, 2,4, 6-tris (4-formylphenyl) -1,3, 5-triazine and 2, 5-dihydroxy-1, 4-p-phenylenediamine hydrochloride are uniformly mixed in an organic solvent and then react under the catalysis of a weak alkaline catalyst to obtain the covalent organic framework material A.

1,3,6, 8-tetra (4-formylphenyl) pyrene and 2, 5-dihydroxy-1, 4-p-phenylenediamine hydrochloride are uniformly mixed in an organic solvent and react under the catalysis of a weak alkaline catalyst to obtain a covalent organic framework material B.

Wherein the molar ratio of the 2,4, 6-tri (4-formylphenyl) -1,3, 5-triazine or 1,3,6, 8-tetra (4-formylphenyl) pyrene to the 2, 5-dihydroxy-1, 4-p-phenylenediamine hydrochloride is 1 (1-2). In addition, the molar ratio is preferably 1: 1.5.

The total concentration of 2,4, 6-tri (4-formylphenyl) -1,3, 5-triazine and 2, 5-dihydroxy-1, 4-p-phenylenediamine hydrochloride or the total concentration of 1,3,6, 8-tetra (4-formylphenyl) pyrene and 2, 5-dihydroxy-1, 4-p-phenylenediamine hydrochloride is 1-100 g/L.

In addition, the organic solvent is a mixture of N-methylpyrrolidone and mesitylene, or a mixture of 1, 3-dimethylimidazolidinone and mesitylene.

In addition, the weakly basic catalyst is one of benzimidazole, imidazole, quinoline or isoquinoline.

In addition, the dosage of the weak alkaline catalyst is 0.8 to 40 times of the molar dosage of the 2, 5-dihydroxy-1, 4-p-phenylenediamine hydrochloride.

In addition, the reaction was carried out at 150 ℃ and 250 ℃.

In addition, in the synthesis method of the invention, the reaction preferably occurs in a sealed reactor, the reaction time is five days, and the covalent organic framework material connected with the benzoxazole can be obtained after centrifugation and drying.

The invention also provides a benzoxazole-linked covalent organic framework material prepared by the synthesis method.

The benzoxazole-linked covalent organic framework material has a long-range ordered structure and regular pore channels. The benzoxazole-linked covalent organic framework material is a new material synthesized by adopting an oxazole ring linking mode, can fully maintain the stability of the material in different solvent environments, keeps the original properties of the material unchanged, particularly keeps the crystal form and the ordered pore passage of the material unchanged after being soaked in strong acid and strong alkali for three days, and does not decompose the material.

Drawings

FIG. 1 is an X-ray diffraction pattern of the product of example 1.

FIG. 2 is a solid nuclear magnetic spectrum of LZU-191.

FIG. 3 is an infrared spectrum of LZU-191.

FIG. 4 shows a nitrogen adsorption/desorption curve and a pore size distribution curve of LZU-191.

FIG. 5 is a thermogravimetric plot of LZUI-191.

FIG. 6 is an X-ray diffraction pattern of the product of example 2.

FIG. 7 is a solid nuclear magnetic spectrum of LZU-192.

FIG. 8 is an infrared spectrum of LZU-192.

FIG. 9 shows a nitrogen adsorption/desorption curve and a pore size distribution curve of LZU-192.

FIG. 10 is a thermogravimetric plot of LZU-192.

FIG. 11 is a powder X-ray diffraction pattern of material LZU-191 after treatment with boiling water, trifluoroacetic acid, 9M hydrochloric acid solution, and 9M sodium hydroxide solution, respectively.

FIG. 12 is a powder X-ray diffraction pattern of material LZU-192 after treatment with boiling water, trifluoroacetic acid, 9M hydrochloric acid solution, and 9M sodium hydroxide solution, respectively.

Detailed Description

The preferred conditions of the present invention are further illustrated below in conjunction with the following examples, it being understood that the preferred examples described herein are intended to illustrate and explain the present invention, and are not intended to limit the present invention.

If not specifically stated, 2,4, 6-tri (4-formylphenyl) -1,3, 5-triazine and 2, 5-dihydroxy-1, 4-p-phenylenediamine hydrochloride are uniformly mixed in an organic solvent and react under the catalysis of a weak alkaline catalyst to obtain a covalent organic framework material A, wherein the covalent organic framework material A has the following chemical formula: LZU-191.

1,3,6, 8-tetra (4-formylphenyl) pyrene and 2, 5-dihydroxy-1, 4-p-phenylenediamine hydrochloride are uniformly mixed in an organic solvent and react under the catalysis of a weak alkaline catalyst to obtain a covalent organic framework material B, wherein the covalent organic framework material B is named as follows: LZU-192.

Example 1: synthesis of benzoxazole-linked covalent organic framework material LZU-191

26.1mg of 2,4, 6-tris (4-formylphenyl) -1,3, 5-triazine and 21.3mg of 2, 5-dihydroxy-1, 4-p-phenylenediamine hydrochloride were charged to a 10mL ampule. Then 35.4mg of benzimidazole was added, followed by shaking and addition of 0.5mL of N-methylpyrrolidone and 0.5mL of mesitylene. The ampoule was placed in liquid nitrogen and after the solution solidified, it was evacuated to 0mbar and then sealed. The mixture was placed in an oven and reacted at 180 ℃ for five days. After the reaction, a solid was generated at the bottom of the ampule, and the solid was transferred to a centrifuge tube and washed 3 times with acetone and tetrahydrofuran, respectively. The solid was dried at 100 ℃ to give LZU-19128.5 mg as a brown solid in 78% yield.

FIG. 1 is an X-ray diffraction pattern of the product of example 1, wherein FIG. 1a corresponds to LZU-191, FIG. 1b corresponds to 2,4, 6-tris (4-formylphenyl) -1,3, 5-triazine, and FIG. 1c corresponds to 2, 5-dihydroxy-1, 4-p-phenylenediamine hydrochloride. By comparing the powder X-ray diffraction pattern of the LZU-191 and the raw material, the invention can be confirmed to successfully synthesize a new crystal form material.

FIG. 2 is a solid nuclear magnetic spectrum of LZU-191.

FIG. 3 is an infrared spectrum of LZU-191 wherein FIG. 3a corresponds to 2, 5-dihydroxy-1, 4-p-phenylenediamine hydrochloride, FIG. 3b corresponds to 2,4, 6-tris (4-formylphenyl) -1,3, 5-triazine, and FIG. 3c corresponds to LZU-191.

FIG. 4 is a nitrogen adsorption and desorption curve and a pore size distribution curve of LZU-191, and the data show that the material has larger specific surface area and regular pore channel structure.

FIG. 5 is a thermogravimetric plot of LZUI-191.

Example 2: synthesis of benzoxazole-linked stable covalent organic framework material LZU-192

Synthesized and characterized as in example 1. 30.9mg of 1,3,6, 8-tetrakis (4-formylphenyl) pyrene and 21.3mg of 2, 5-dihydroxy-1, 4-p-phenylenediamine hydrochloride gave LZU-19233.4mg as a yellow solid powder in 81% yield.

FIG. 6 is an X-ray diffraction pattern of the product of example 2, wherein FIG. 6a corresponds to LZU-192, FIG. 6b corresponds to 1,3,6, 8-tetrakis (4-formylphenyl) pyrene, and FIG. 6c corresponds to 2, 5-dihydroxy-1, 4-p-phenylenediamine hydrochloride. By comparing the powder X-ray diffraction pattern of the LZU-192 and the raw material, the invention can be confirmed to successfully synthesize a new crystal form material.

FIG. 7 is a solid nuclear magnetic spectrum of LZU-192.

FIG. 8 is an infrared spectrum of LZU-192, wherein FIG. 8a corresponds to 2, 5-dihydroxy-1, 4-p-phenylenediamine hydrochloride, FIG. 8b corresponds to 1,3,6, 8-tetrakis (4-formylphenyl) pyrene, and FIG. 8c corresponds to LZU-192.

FIG. 9 shows the nitrogen desorption curve and the pore size distribution curve of LZU-192, which indicates that the material has a large specific surface area and a regular pore structure.

FIG. 10 is a thermogravimetric plot of LZU-192.

Test example: stability testing of LZU-191 and LZU-192

The obtained LZU-191 and LZU-192 materials are respectively placed in boiling water, trifluoroacetic acid, 9M hydrochloric acid solution and 9M sodium hydroxide solution for soaking for three days, then the materials are obtained again by suction filtration, and the powder X-ray diffraction and nitrogen adsorption experiments are tested after the materials are dried.

The crystal form of the material after the treatment method can be kept, the material is not decomposed in the treatment process, ordered pore channels of the material can be seen to be not damaged through a pore size distribution test, and the specific surface area can be well kept.

Finally, it should be noted that: although the present invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that changes may be made in the embodiments and/or equivalents thereof without departing from the spirit and scope of the invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A benzoxazole-linked covalent organic framework material, characterized in that the preparation method of the material comprises the following steps:

uniformly mixing 2,4, 6-tri (4-formylphenyl) -1,3, 5-triazine or 1,3,6, 8-tetra (4-formylphenyl) pyrene and 2, 5-dihydroxy-1, 4-p-phenylenediamine hydrochloride in an organic solvent, and reacting under the catalysis of a weak alkaline catalyst to obtain a covalent organic framework material;

the molar ratio of the 2,4, 6-tri (4-formylphenyl) -1,3, 5-triazine or 1,3,6, 8-tetra (4-formylphenyl) pyrene to the 2, 5-dihydroxy-1, 4-p-phenylenediamine hydrochloride is 1 (1-2);

the total concentration of 2,4, 6-tri (4-formylphenyl) -1,3, 5-triazine and 2, 5-dihydroxy-1, 4-p-phenylenediamine hydrochloride or the total concentration of 1,3,6, 8-tetra (4-formylphenyl) pyrene and 2, 5-dihydroxy-1, 4-p-phenylenediamine hydrochloride is 1-100 g/L;

the organic solvent is a mixture of N-methyl pyrrolidone and mesitylene, or a mixture of 1, 3-dimethyl imidazolidinone and mesitylene;

the weak base catalyst is one of benzimidazole, imidazole, quinoline or isoquinoline, and the dosage of the weak base catalyst is 0.8-40 times of the molar dosage of 2, 5-dihydroxy-1, 4-p-phenylenediamine hydrochloride;

the reaction is carried out at 150 ℃ and 250 ℃.