CN115124677A

CN115124677A - Meltable metal organic framework material and covalent organic framework material, preparation method and application thereof

Info

Publication number: CN115124677A
Application number: CN202210748788.9A
Authority: CN
Inventors: 万重庆; 辜小玲; 李国强
Original assignee: Capital Normal University
Current assignee: Capital Normal University
Priority date: 2022-06-28
Filing date: 2022-06-28
Publication date: 2022-09-30
Anticipated expiration: 2042-06-28
Also published as: CN115124677B

Abstract

The invention discloses a meltable metal organic framework material, a covalent organic framework material, a preparation method and application thereof. The preparation of glassy state a by modification of metal-organic framework materials and covalent organic framework materials by an internal salt structure R and by the introduction of Bronsted acids _g MOF-R-HA and a _g The COF-R-HA material can be heated and melted at a medium and low temperature, so that the melting processing of the material is realized, and the inevitable problem of grain boundary in the processing process of a polycrystalline material is solved. The MOF/COF material after melt processing has the characteristics of a glass structure, is beneficial to obtaining high conductivity and planar two-dimensional materials, and expands the application of the material in different fields including proton or lithium ion conduction and the like.

Description

Meltable metal organic framework material and covalent organic framework material, preparation method and application thereof

Technical Field

The invention relates to the field of advanced material processing, in particular to a covalent organic framework material modified by an inner salt structure, a preparation method and application thereof, and more particularly relates to a glassy material prepared by using an ionic liquid functionalized metal organic framework material and a covalent organic framework material through low-temperature hot melting and low-temperature processing.

Background

Metal Organic Framework (MOF) and Covalent Organic Framework (COF) as porous crystalline materials with large surface area, customizable pore size, ligand modifiability, and tunable three-dimensional structureThe pore canal is widely used in the fields of gas adsorption and storage, separation, catalysis, sensing, electric conduction and the like. At present, many industrial applicability problems are faced in the application, such as that these materials exist in powder form and cannot form films or fibers with high mechanical strength by themselves. Generally, methods such as high-pressure granulating agent, interfacial polymerization, vacuum filtration and the like are used for forming metal organic framework materials and covalent organic framework material powder, but the processing methods obviously reduce the performance of the materials, and the COF/MOF membrane materials with no defects and strong mechanical properties can not be prepared on a large scale. To overcome these disadvantages, the ideal solution is to melt the metal organic framework materials and covalent organic framework materials before the thermal decomposition temperature, cast the liquid COF/MOF and then quench to obtain COF/MOF glass. However, only a few nitrogen-containing heterocyclic ligands and divalent metals Zn are present in MOF materials ²⁺ Or Co ²⁺ The ZIFs formed by ion coordination can be thermally melted, and the decomposition temperature of the COF material is often lower than the melting temperature of the COF material, so that the COF material is decomposed without being melted during heating, and a liquid COF material cannot be obtained, thereby greatly limiting the COF/MOF material.

Attempts have been made to modify COF materials, for example in the document Accumulation of glass Polymer (ethylene oxide) absorbed in a volatile Organic Framework as a Solid-State Li ⁺ Electroyte, Gen Zhang et al, j.am. chem. soc.2019,141,1227-1234, wherein a self-assembly method of introducing 3-molecule polymerized, 6-molecule polymerized and 9-molecule polymerized polyethylene oxide (PEO) chains into the internal space of a two-dimensional COF from bottom to top is reported, the accumulated PEO chains are highly dynamic and exhibit a glassy state, and rapid transport can be achieved by dissolving lithium ions through their segmental motion. However, the surface modification is only carried out on the COF framework material, the added PEO chain does not realize the melting of COFs, and the heat melting of a pure COF material is not reported; in addition, in the prior art, coding Polymer Glasses with Lava and health adherence for High-Performance Gas Sieving, Jie Li et al (Angew. chem. int. Ed.10.1002/anie.202102047), and Liquid, glass and atmospheric solids of coding polymers and metal-organic frames, T.D Bennett et al (nat. reviews doi. org/10.1038/s41578-018-0054-3) disclose the use of transformed glassy inorganic porous membranes for efficient gas separation by facilitating the melting of Coordination Polymers (CP) or metal-organic frames (MOF) by simple heating or hot pressing methods. However, these results are limited to nitrogen-containing heterocyclic ligands and divalent metal Zn ²⁺ 、Co ²⁺ There has been no report of thermal fusion of CP or MOF formed by ion coordination to the most stable and most diverse carboxylic ligand species in the family.

There is therefore still a need to develop new methods of MOF/COF materials that are capable of hot-melting. The MOF/COF material modified by the inner salt structure can realize medium-low temperature hot melting, so that a new processing path of the MOF/COF material is developed, the defect that MOF/COF powder is difficult to process is overcome, and the application of the MOF/COF material in separation and purification, proton conduction and lithium ion conduction is expanded. Realizes large-scale preparation of MOF/COF film materials with flexibility, no defects and strong machinability.

Disclosure of Invention

In order to solve the problems, the invention provides an MOF or COF material which can be melted at a medium-low temperature, wherein a metal organic framework material or a covalent organic framework material (MOF/COF-DHz-R) with an inner salt structure modification is synthesized firstly, and then different kinds of Bronsted acid (HA) are doped into the MOF/COF-DHz-R, so that the MOF-R-HA or COF-DHz-R-HA which can be melted at the medium-low temperature is prepared, and a vitreous body a can be further prepared by heating and quenching _g MOF-R HA or a _g COF-DHz-R.HA, which can be used for fast ion conducting material, embedding and loading substance (harmful substance, medicine), and the solvent activation material can be used for preparing membrane material with separation and purification functions.

According to one aspect of the invention, it is an object of the invention to provide an inner salt structure modified covalent organic framework material consisting of C ₃ Symmetrical aldehyde monomer and C modified with inner salt structure R ₂ Symmetric hydrazide monomer (DHz-R) by Schiff base condensationObtained by reaction wherein C ₃ Symmetrical aldehyde monomer and C modified with inner salt structure R ₂ The molar ratio of the symmetrical hydrazide monomers was 2: 3.

Wherein, the C ₃ The symmetrical aldehyde monomer is selected from the following compounds:

c modified with inner salt structure R ₂ The symmetrical hydrazide monomers are selected from the compounds shown below:

wherein R is selected from the following structures:

wherein n is an integer of 2,3, 4 or 5;

preferably, when R is selected from

When n is an integer of 3,4 or 5;

preferably, when R is selected from

When n is an integer of 3,4 or 5;

preferably, when R is selected from

When n is an integer of 3 or 4.

According to another aspect of the present invention, it is another object of the present invention to provide a meltable material made from said internal salt structure modified covalent organic framework material structure, said meltable material being formed by reacting said internal salt structure modified covalent organic framework material with a bronsted acid (HA), wherein said bronsted acid is selected from the group consisting of: methanesulfonic acid (MSA), ethanesulfonic acid (ESA), trifluoromethanesulfonic acid (TFA), bistrifluoromethylsulfonyl imide (TFSA), phosphoric acid (H) ₃ PO ₄ ) Sulfuric acid (H) ₂ SO ₄ ) Any one of them.

Preferably, in the preparation of the meltable material with the covalent organic framework structure modified by the inner salt structure, the covalent organic framework material modified by the inner salt structure and the Bronsted acid (HA) are ground until the covalent organic framework material and the Bronsted acid are mixed uniformly and completely, then the mixture is heated at a medium and low temperature of 100-250 ℃ for 30-40 min to obtain a melt, and a glassy product is prepared by cooling and quenching, wherein the molar ratio of the covalent organic framework material modified by the inner salt structure to the HA is 1: 1-1: 10, and preferably 1:1.

According to still another aspect of the present invention, it is still another object of the present invention to provide a method for preparing the inner salt structure-modified covalent organic framework material, the method comprising the steps of:

(1) preparation of C2 symmetric hydrazide monomer modified with inner salt structure R (DHz-R):

c modified with inner salt structure R is obtained by utilizing C2 symmetric amino/imidazole/pyridyl modified hydrazide monomer (DHz) and sultone/dicyanovinyl lactone to carry out ring opening reaction or amino/imidazole/pyridyl modified hydrazide precursor (DHz) and substitution and dealcoholization reaction of different alkyl bromo-carboxylic acid esters ₂ A symmetric hydrazide monomer (DHz-R);

(2) preparation of covalent organic framework COF material modified by inner salt structure:

modifying the C modified with the inner salt structure R obtained in the step (1) ₂ Symmetrical hydrazide monomer (DHz-R) and corresponding C ₃ Placing symmetrical aldehyde monomer in mixed solventAdding a protonic acid catalyst, ultrasonically mixing, vacuumizing, sealing a reaction system, reacting at 120-130 ℃ for 3-8 days, cooling the reaction system after the reaction is finished, centrifuging to obtain a precipitate, cleaning the precipitate, drying, and activating to obtain the covalent organic framework COF material (COF-DHz-R) modified by the inner salt structure.

Preferably, C modified with an inner salt structure R in step (1) ₂ The symmetrical hydrazide monomers are selected from the compounds shown below:

preferably, the corresponding inner salt having the structure of R in step (1) is selected from the group consisting of inner salts of sulfamic acid, inner salts of aminocarboxylic acid, inner salts of aminodicyanovinic acid, inner salts of imidazolesulfonic acid, inner salts of imidazolecarboxylic acid, inner salts of imidazoldicyanovinic acid, inner salts of pyridinesulfonic acid, inner salts of pyridinecarboxylic acid, inner salts of pyridinedicyanovinic acid

Further preferably, in step (1) said R is selected from the following structures:

wherein n is an integer of 2,3, 4 or 5;

preferably, when R is selected from

When n is an integer of 3,4 or 5;

preferably, when R is selected from

When n is an integer of 3,4 or 5;

preferably, when R is selected from

When n is an integer of 3 or 4.

More preferably, the corresponding inner salt of the R structure is selected from APS (aminopropanesulphonate, n ═ 3), ABS (aminobutanesulphonate, n ═ 4), MIMPS (imidazolepropanesulphonate, n ═ 3) and MIMBS (imidazolbutanesulphonate, n ═ 4).

Preferably, said C in step (2) ₃ The symmetrical aldehyde monomer is selected from the following compounds:

preferably, the mixed solvent in the step (2) is mesitylene and 1, 4-dioxane in a volume ratio of 9:1 or o-dichlorobenzene and n-butanol in a volume ratio of 1:1.

Preferably, the protonic acid catalyst in step (2) is trifluoroacetic acid or an aqueous acetic acid solution.

According to a further aspect of the present invention, it is a further object of the present invention to provide a method for preparing said meltable material having said internal salt structure modified covalent organic framework structure, said method comprising the steps of:

grinding a certain amount of covalent organic framework COF (COF-DHz-R) material modified by an inner salt structure in a mortar until the powder is fluffy, quantitatively transferring different types of Bronsted acid (HA), continuously grinding until the materials are uniformly mixed, heating at a medium and low temperature of 100-250 ℃ for 30-40 min to obtain a melt, and cooling and quenching to obtain a glassy product a _g COF-DHz-R·HA。

Preferably, the molar ratio of the COF-DHz-R material to bronsted acid (HA) is between 1:1 and 1:10, preferably 1: 1; the heating temperature is 100-160 ℃; the heating time is 1-5 min.

Preferably, said Bronsted acid (HA)Are methanesulfonic acid (MSA), ethanesulfonic acid (ESA), trifluoromethanesulfonic acid (TFA), bistrifluoromethanesulfonylimide (TFSA), phosphoric acid (H) ₃ PO ₄ ) Sulfuric acid (H) ₂ SO ₄ ) Any one of them.

According to one aspect of the invention, the invention aims to provide an internal salt structure modified Metal-organic framework material, wherein the Metal-organic framework material is formed by Metal ions (M) or Metal clusters (Metal cluster) and internal salt modified dicarboxylic acid organic ligands (L-R) through coordination bonds to form a porous MOF material;

transition metal ions in which the metal M is a valence of 3 to 4, selected from Fe, Cr, Zr, Ti or Hf, and may be selected, for example, from Fe ³⁺ 、Cr ³⁺ 、Zr ⁴⁺ Ti or Hf ⁴⁺ ；

The metal cluster is selected from [ M ₃ (μ ₃ -O/OH)(COO) ₆ ](M＝Fe ³⁺ ，Cr ³⁺ ，MiL-101，MiL-100)、 [MO ₄ (OH) ₂ ](M＝Al ³⁺ DUT-5) and [ M ₆ O ₄ (μ ₃ -OH) ₄ ](M＝Zr ⁴⁺ 、Ti ⁴⁺ Or Hf ⁴⁺ UiO-66/67/68(Zr) or UiO-66/67/68(Ti) or UiO-66/67/68 (Hf)).

Wherein the dicarboxylic acid organic ligand L-R is selected from the following compounds:

preferably, when R is selected from

When n is an integer of 3,4 or 5;

preferably, when R is selected from

When n is an integer of 3,4 or 5;

preferably, when R is selected from

When n is an integer of 3 or 4.

More preferably, the corresponding internal salt of the R structure is selected from APS (aminopropanesulphonate, n ═ 3), ABS (aminobutanesulphonate, n ═ 4), MPPS (pyridylpropanesulphonate, n ═ 3).

According to another aspect of the invention, it is another object of the invention to provide a meltable material (MOF-R-HA) having said internal salt structure modified metal-organic framework structure, said meltable material being formed by reacting said internal salt structure modified metal-organic framework material with a bronsted acid (HA), wherein said bronsted acid is selected from the group consisting of: methanesulfonic acid (MSA), ethanesulfonic acid (ESA), trifluoromethanesulfonic acid (TFA), bistrifluoromethylsulfonylimide (TFSA), phosphoric acid (H) ₃ PO ₄ ) Sulfuric acid (H) ₂ SO ₄ ) Any one of them.

Preferably, in the preparation of the meltable material with the metal organic framework material modified by the inner salt structure, the metal organic framework material modified by the inner salt structure and Bronsted acid (HA) are ground until the metal organic framework material and the Bronsted acid are uniformly and completely mixed, then the mixture is heated at a medium and low temperature of 100-250 ℃ for 30-40 min to obtain a melt, and then the melt is cooled and quenched to obtain a glassy product, wherein the molar ratio of a ligand L-R to the HA in the MOF framework material modified by the inner salt structure is 1: 3-1: 10, and preferably 1: 4.

According to another aspect of the present invention, it is another object of the present invention to provide a method for preparing the inner salt structure modified metal organic framework material (MOF-R), the method comprising the steps of:

(1) preparation of dicarboxylic acid organic ligand L-R modified by inner salt structure

Performing a ring opening reaction on the corresponding reaction precursor amino/pyridyl modified dicarboxylic acid organic ligand and sultone/dicyanovinyl lactone, or performing substitution and dealcoholization reaction on the amino/pyridyl modified dicarboxylic acid organic ligand and different alkyl bromocarboxylates to obtain a dicarboxylic acid organic ligand (L-R) modified with an inner salt structure R;

(2) preparation of the metal organic framework MOF-R material modified by the inner salt structure:

and (2) placing the dicarboxylic acid organic ligand (L-R) modified by the inner salt and the Metal salt corresponding to the Metal (M) or the Metal cluster (Metal cluster) in a N, N-Dimethylformamide (DMF) solvent, adding a protonic acid regulator, ultrasonically mixing, reacting in a polytetrafluoroethylene-lined reaction kettle at the temperature of 80-180 ℃, cooling the reaction system after the reaction is finished, centrifuging to obtain a reaction precipitate, cleaning, drying and activating the precipitate to obtain the porous MOF-R material with the inner salt modified structure.

Preferably, the ratio of the organic ligand (L-R) to the metal salt in step (2) is 1:1.

Preferably, in step (2), the protonic acid regulator is preferably 75 equivalents of acetic acid based on 1 equivalent of the metal salt.

Preferably, the metal M in step (2) is a transition metal ion having a valence of 3 to 4, selected from Fe, Cr, Zr or Hf, and may be selected from Fe ³⁺ 、Cr ³⁺ 、Zr ⁴⁺ Or Hf ⁴⁺ ；

The metal cluster is selected from [ M ₃ (μ ₃ -O/OH)(COO) ₆ ](M＝Fe ³⁺ ，Cr ³⁺ ，MiL-101，MiL-100)、 [MO ₄ (OH) ₂ ](M＝Al ³⁺ DUT-5) and [ M ₆ O ₄ (μ ₃ -OH) ₄ ](M＝Zr ⁴⁺ Or Hf ⁴⁺ UiO-66(Zr) or UiO-66 (Hf)).

Preferably, the dicarboxylic acid organic ligand L-R in the step (1) is selected from the compounds shown as follows:

preferably, when R is selected from

When n is an integer of 3,4 or 5;

preferably, when R is selected from

When n is an integer of 3,4 or 5;

preferably, when R is selected from

When n is an integer of 3 or 4.

According to another aspect of the present invention, another object of the present invention is to provide a method for preparing the meltable material having the metal-organic framework structure with the internal salt structure modification, the method comprising the following steps:

grinding a certain amount of the MOF-R material in a mortar until the powder is fluffy, quantitatively transferring Bronsted acid (HA) into the mortar, continuously grinding until the mixture is uniformly and completely mixed, heating at a medium and low temperature of 100-250 ℃ for 30-40 min to obtain a melt, and cooling and quenching to obtain a glassy state product a _g MOF-R·HA。

Preferably, the melting points of the samples are controlled by controlling different amounts of acid, so as to obtain MOF-R-HA with different melting points, wherein the molar ratio of dicarboxylic organic ligands L-R to HA in the MOF-R is between 1:3 and 1:10, preferably 1: 4; the heating temperature is 100-160 ℃.

Preferably, the Bronsted acid (HA) is methanesulfonic acid (MSA), ethanesulfonic acid (ESA), trifluoromethanesulfonic acid (TFA), bis-Trifluoromethanesulfonimide (TFSA), phosphoric acid (H) ₃ PO ₄ ) Sulfuric acid (H) ₂ SO ₄ ) Any one of them.

According to another aspect of the invention, it is another object of the invention to provide meltable material of said COF with said internal salt structure modified covalent organic framework structure or of MOF of metal organic framework material as ion conducting material (such as H ⁺ 、Li ⁺ 、Na ⁺ 、K ⁺ Etc.), optical devices, multifunctional glasses, gas adsorption separation membranes, etc.

Compared with the prior art, the invention has the beneficial effects that:

the MOF-R.HA material modified by the ionic liquid prepared by the invention can be heated and melted at a medium and low temperature to form a glassy state a _g The MOF-R-HA material HAs the advantages of uniformity, continuity, no defect and light transmission, is beneficial to the application of metal organic framework material MOF on ion conductive materials, and can be used as a novel optical device material.

The binary ionic liquid is introduced into the metal organic framework, so that the melt processing of MOFs materials, such as film material preparation and material molding, is promoted, the characteristics of the host material and the guest material can realize pore structure recovery by a method for removing guest molecules, and the application requirements of the pore materials in the aspects of adsorption, separation and the like can be met.

The covalent organic framework material synthesized by the invention belongs to beta-ketoenamine COF, and can maintain chemical stability in strong acid, strong base and different solvents.

The preparation method comprises the steps of carrying out Schiff base reaction on a hydrazide monomer modified by an inner salt structure and an aldehyde group monomer to prepare beta-ketoenamine COFs, introducing different types of Bronsted acids into a covalent organic framework material by a grinding and dipping method, and preparing the COF material modified by the ionic liquid. The glass state COF material is heated and melted at a certain temperature, has the advantages of uniformity, continuity and no defect, and is beneficial to the further development of covalent organic framework materials in proton conduction and lithium ion conduction materials.

The invention designs the synthesized covalent organic framework material modified by the meltable inner salt structure, overcomes the difficult problem of difficult processing of COF materials, is beneficial to synthesizing uniform separation membranes with strong processability, and expands the application of the covalent organic framework material in separation and purification.

The invention designs the synthesized covalent organic framework material modified by the meltable inner salt structure, overcomes the inevitable grain boundary problem of the polycrystalline conductive material, has enough sites for the COF material after melting processing, is beneficial to obtaining high conductivity, and expands the application of the covalent organic framework material in proton conduction and lithium ion conduction.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and other drawings can be obtained by those skilled in the art without creative efforts.

FIG. 1 is an X-ray powder diffraction diagram of the material COF-DHz-APS obtained according to example 1.

FIG. 2 is an IR spectrum of the material COF-DHz-APS obtained according to example 1.

FIG. 3 shows the materials COF-DHz-APS. MSA, COF-DHz-APS. ESA, a obtained according to example 3 _g COF-DHz-APS·MSA，a _g COF-DHz-APS. ESA in X-ray powder diffraction pattern.

FIG. 4 is a differential scanning calorimetry chart of the materials COF-DHz-APS, COF-DHz-APS. MSA obtained in examples 1 and 3.

FIG. 5 shows the materials COF-DHz-APS, a obtained according to examples 1 and 3 _g COF-DHz-APS·MSA， a _g SAXS diagram of COF-DHz-APS. ESA, and reference polycarbonate, silica glass plate.

FIG. 6 shows a material a obtained according to example 3 _g A polarized light microscope image of COF-DHz-APS & MSA.

FIG. 7 shows the materials COF-DHz-APS, a obtained according to examples 1 and 3 _g SEM picture of COF-DHz-APS. MSA.

FIG. 8 shows the materials COF-DHz-APS, a obtained according to examples 1 and 3 _g COF-DHz-APS. MSA.

Fig. 9 is an X-ray powder diffraction pattern of the material COF-DHz-MIMPS obtained according to example 2.

Fig. 10 is an ir spectrum of the material COF-DHz-MIMPS obtained according to example 2.

FIG. 11 is an optical microscope photograph of the material COF-DHz-MIMPS. MSA obtained in examples 2 and 4 before and after heating.

FIG. 12 shows a material a obtained in example 4 _g COF-DHz-MIMPS. MSA.

FIG. 13 is the material COF-DHz-MIMPS, a obtained according to examples 2 and 4 _g COF-DHz-MIMPS. MSA conductivity diagram.

FIG. 14 shows materials UiO-66, UiO-66-APS. MSA, UiO-66-APS. ESA, a obtained in examples 5 to 6 _g UiO-66-APS MSA and a _g Powder X-ray diffraction pattern of UiO-66-APS & ESA.

FIG. 15 is optical micrographs of the materials UiO-66-APS. MSA and UiO-66-APS. ESA obtained in example 5 according to the invention before and after heating.

FIG. 16 Material a obtained in example 5 _g UiO-66-APS MSA and UiO-66-APS ESA are obtained by parallel polarization detection and orthogonal polarization detection under a polarized light microscope with an upper analyzer and a lower analyzer at an angle of 45 degrees.

FIG. 17 shows the materials UiO-66-APS. MSA, UiO-66-APS. ESA, a obtained in examples 5 to 6 _g UiO-66-APS MSA and a _g SEM picture of UiO-66-APS. ESA.

FIG. 18 is a differential scanning calorimetry chart of the materials UiO-66-APS-MSA and UiO-66-APS-ESA obtained in example 5.

FIG. 19 shows a material a obtained in example 6 _g UiO-66-APS MSA and a _g UiO-66-APS. ESA.

FIG. 20 shows the materials UiO-67, UiO-67-MPPS, UiO-66-MPPS. MSA, a obtained according to examples 7 and 8 _g Powder X-ray diffraction pattern of UiO-66-MPPS. MSA.

FIG. 21 shows optical micrographs of the material UiO-67-MPPS. MSA obtained in example 7 before and after heating.

FIG. 22 is a photograph under an optical microscope before and after heating of the material UiO-67-MPPS. MSA obtained in examples 7 and 8, and photographs under parallel polarization detection and orthogonal polarization detection by a polarizing microscope.

FIG. 23 shows the material UiO-67-MPPS. MSA, a obtained according to example 5 _g SEM picture of UiO-67-MPPS. MSA.

FIG. 24 is a differential scanning calorimetry chart of the material UiO-67-MPPS-MSA obtained in example 7.

Detailed Description

Hereinafter, preferred embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. Before the description, it should be understood that the terms used in the specification and the appended claims should not be construed as limited to general and dictionary meanings, but interpreted based on the meanings and concepts corresponding to technical aspects of the present invention on the basis of the principle that the inventor is allowed to define terms appropriately for the best explanation. Accordingly, the description herein is intended as a preferred example for the purpose of illustration only and is not intended to limit the scope of the present invention, so it should be understood that other equivalent implementations and modifications could be made without departing from the spirit and scope of the present invention.

The covalent organic framework materials (COF-DHz-R) modified by the inner salt structure according to the invention consist of C ₃ Symmetrical aldehyde-based monomers and C modified with an inner salt structure R ₂ Symmetric hydrazide monomers (DHz-R) are obtained by schiff base condensation reactions, exemplified by COF-DHz-APS and COF-DHz-MIMPS, i.e. R is an sulfamate (APS) group (n ═ 3) or R is an imidazolium sulfonate (MIMPS) group (n ═ 3), and the structural formula is as follows:

in the preparation method of the covalent organic framework material modified by the inner salt structure, the method comprises the following steps:

(a) when the inner salt structure of hydrazide monomer DHz-R is ammonium, DHz-R is prepared as shown in equation 1 below:

the general chemical reaction is hydrazide precursor DHz-NH modified by amino group ₂ With sultone, dicyanovinyl lactone, or amino-modified hydrazide precursor DHz-NH ₂ Substitution and dealcoholization reaction with different alkyl bromo-carboxylic acid esters to prepare DHz-R modified by ammonium salt inner salt.

Synthesis of hydrazide monomer DHz-APS modified with a specific ammoniopropanesulfonate APS inner salt (n ═ 3): fully grinding and uniformly mixing dimethyl 2-amino terephthalate (3.77g,18mmol) and liquid nitrogen cooled 1, 3-propane sultone (1494ul,18mmol) in a mortar, transferring the mixture into a 20ml single-mouth bottle, reacting for 1-8 hours, preferably 3 hours, at 90-150 ℃, preferably 130 ℃, cooling the reaction system after the reaction is finished, washing the obtained dark red solid with acetic acid (17M) for 2-4 times, then washing with acetone twice, and drying to obtain white ammonium propane sulfonic acid inner salt (APS) structure modified dimethyl terephthalate powder. And then putting the hydrazine hydrate solution and the hydrazine hydrate solution in absolute ethyl alcohol according to the molar ratio of 1:2, carrying out reaction at room temperature to 120 ℃, preferably at 80 ℃, carrying out reaction for 1-48 hours, preferably 36 hours, centrifuging to obtain a precipitate, and drying the precipitate to obtain the yellow hydrazide monomer DHz-APS modified by the APS inner salt structure.

(b) When the internal salt structure of the hydrazide monomer DHz is imidazole or pyridine, the chemical reaction is shown in the following reaction formula 2:

the general chemical reaction is that imidazole/pyridyl modified hydrazide precursor and different sultone/dicyan lactone ring-opening reaction or the substitution and dealcoholization reaction of imidazole/pyridyl modified hydrazide precursor and different alkyl bromo-carboxylate.

Example of synthesis of hydrazide monomer DHz-MIMPS modified with MIMPS of specific imidazolylpropylsulfonate inner salt structure (n ═ 3): dimethyl 2- (imidazolylmethyl) biphenyl-4, 4' -dicarboxylate (2.0g,5.71mmol) was dissolved in acetone, and 1, 3-propanesultone (0.697g,5.71mmol) was slowly added. The solution is stirred for 2 to 7 days, preferably 5 days at room temperature, filtered and precipitated, and is washed by acetone and dried to obtain white powder of the biphenyl-4, 4' -dicarboxylic acid dimethyl ester modified by the imidazole sulfonate inner salt group MIMPS. And then putting the hydrazine hydrate solution and the hydrazine hydrate solution in absolute ethyl alcohol according to the molar ratio of 1:2, carrying out reaction at room temperature to 120 ℃, preferably at 80 ℃, carrying out reaction for 1-48 hours, preferably for 36 hours, centrifuging to obtain a precipitate, and drying the precipitate to obtain the white MIMPS inner salt structure modified hydrazide monomer DHz-MIMPS.

modifying C modified with inner salt structure R obtained in step (1) ₂ Symmetrical hydrazide monomer (DHz-R) and corresponding C ₃ Putting symmetrical aldehyde monomers into a mixed solvent, adding a protonic acid catalyst, ultrasonically mixing, vacuumizing, sealing a reaction system, reacting for 3-8 days at 120-130 ℃, cooling the reaction system after the reaction is finished, centrifuging to obtain a precipitate, cleaning, drying and activating the precipitate to obtain the covalent organic framework COF material (COF-DHz-R) modified by the inner salt structure.

Preferably, in step (a) of step (1), the molar ratio of the amino-modified DHz precursor to sultone (n ═ 3, 4)/bromocarboxylate (n ═ 3,4, 5)/dicyanovinolactone (n ═ 2,3) is 1:1 to 1:5, and the reaction temperature is 90 to 160 ℃.

Preferably, in step (b) of step (1), the molar ratio of imidazole/pyridine-modified hydrazide precursor DHz to sultone (n ═ 3, 4)/bromocarboxylate (n ═ 3,4, 5)/dicyanovinolactone (n ═ 2,3) is 1:1 to 1:5, and the reaction temperature is from room temperature to 160 ℃.

The Metal organic framework MOF material modified by the inner salt structure consists of Metal ions (M) or Metal clusters (Metal cluster) and dicarboxylic acid organic ligands modified by the inner salt(L-R) Forming a porous MOF-R material by coordinative bonding, wherein UiO-66-APS is taken as an example, the structural formula is as follows: (wherein the polyhedron represents M) ₆ O ₄ (μ ₃ -OH) ₄ Cluster building block):

the preparation method of the inner salt structure modified metal organic framework material (MOF-R) comprises the following steps:

(a) when the carboxylic acid organic ligand (L-R) modified by the inner salt structure is an amino modified ligand, the general chemical reaction for preparing the L-R is as follows: ligand precursor (L-NH) modified by dicyanovinyl lactone/sultone through amino ₂ ) And (3) carrying out ring opening reaction or bromine-containing carboxylate to prepare the dicarboxylic acid organic ligand modified by the inner salt structure through bromine substitution reaction. L-NH ₂ The compound is reacted with sultone (n ═ 3, 4)/bromocarboxylate (n ═ 3,4, 5)/dicyanovinyl lactone (n ═ 2,3) at a molar ratio of 1:1 to 1:5 and at a reaction temperature of 90 to 160 ℃, and the chemical reaction prepared is as shown in the following reaction formula 3:

concretely, a terephthalic acid ligand H modified with an aminopropanesulfonate APS inner salt group (n-3) ₂ BDC-APS (n ═ 3) is an example, the synthesis proceeds as follows: dimethyl 2-aminoterephthalate and 1, 3-propane sultone are uniformly mixed in a molar ratio of 1:1 to 1:1.5, preferably 1:1. At 90-And (3) reacting at 150 ℃, preferably at 130 ℃ for 1-8 hours, preferably for 3 hours, and cooling the reaction system after the reaction is finished. Washing the solid product with 1-17M acetic acid for 2-4 times, preferably washing with 17M acetic acid for 3 times. Centrifugal drying to obtain the dimethyl terephthalate modified by the ammonio propane sulfonic acid inner salt (APS) structure. Then placing the APS and potassium hydroxide into a mixed solution of water and methanol according to a molar ratio of 1:4, reacting at room temperature to 120 ℃, preferably 80 ℃, for 8-24 hours, preferably 12 hours, dropwise adding hydrochloric acid to acidify until the pH value is 1-3, preferably 1, filtering to obtain a precipitate, and drying the precipitate to obtain the H modified with the APS inner salt structure ₂ BDC-APS。

(b) When the dicarboxylic acid organic ligand L-R modified by the inner salt structure is pyridinium ions, sulfonate groups, carboxylate groups and dicyanovinate anions, the general chemical reaction is as follows: the method comprises the following steps of carrying out a ring opening reaction on a pyridyl modified dicarboxylic acid precursor (L-cy) and different sultones/dicyanovinolactones or carrying out substitution and dealcoholization reactions on different alkyl bromocarboxylates to prepare a dicarboxylic acid organic ligand (L-R) for modifying an imidazole/pyridinium ionic inner salt structure, wherein the molar ratio of the L-cy to the sultones (n-3, 4)/bromocarboxylates (n-3, 4, 5)/dicyanovinolactones (n-2, 3) is 1: 1-1: 5, the reaction temperature is between room temperature and 160 ℃, and the chemical reaction is shown in the following reaction formula 4:

biphenyl dicarboxylic acid ligand H modified with pyridine propyl sulfonate group MPPS (n is 3) with inner salt structure ₂ Example of synthesis of BPDC-MPPS (n ═ 3): dimethyl 2- (pyridylmethyl) biphenyl-4, 4' -dicarboxylate and 1, 3-propanesultone are dissolved in acetone in a molar ratio of from 1:3 to 1:8, preferably 1: 8. Stirring the solution at room temperature for 2-7 days, preferably 5 days, filtering the precipitate, washing with acetone, and drying to obtain white dimethyl bipyridyl-4, 4' -dicarboxylate powder modified by pyridinium sulfonate inner salt group MPPS. Then placing it and lithium hydroxide at a molar ratio of 1:2 to 1:4, preferably 1:4, in a mixed solution of water and methanol at room temperature to 120 deg.CPreferably, the reaction is carried out at 80 ℃ for 8-24 hours, preferably 12 hours, then hydrochloric acid is dripped to acidify to pH 1-3, preferably pH 1, precipitate is obtained by filtration, and the precipitate is dried to obtain H modified with MPPS inner salt structure ₂ BPDC-MPPS(L)。

and (2) placing the dicarboxylic acid organic ligand (L-R) modified by the inner salt and Metal salt corresponding to the Metal (Mteal) or the Metal cluster (Metal cluster) in a solvent, adding a protonic acid regulator, ultrasonically mixing, reacting in a polytetrafluoroethylene-lined reaction kettle at the temperature of 80-180 ℃, cooling the reaction system after the reaction is finished, centrifuging to obtain reaction precipitate, cleaning, drying and activating the precipitate to obtain the porous MOF-R material with the inner salt modified structure.

The preparation of UiO-66-APS modified with the inner salt group of aminopropyl sulfonate APS is taken as an example: ZrCl is treated by ultrasonic waves in a 40ml polytetrafluoroethylene lined reaction kettle ₄ (326mg, 1.39mmol) and H ₂ BDC-APS is dissolved in 27ml of ultra dry DMF at a molar ratio of 1:1 to 1:1.5, preferably 1:1, for about 5 to 10 minutes, preferably 10 minutes. Adding 45-100 equivalents of acetic acid regulator into the DMF solution, preferably 75 equivalents, ultrasonically dispersing for 5 minutes again, and statically storing the reaction kettle in an oven at 80-180 ℃ for 24-72 hours, preferably 120 ℃ for 24 hours. After the temperature of the oven is cooled to room temperature, the solution is centrifugally separated, the obtained yellow (UiO-66-APS) precipitate is washed with DMF and methanol for 2-5 times, preferably 3 times, and finally soaked in methanol for 48-72 hours, preferably 72 hours, and fresh methanol is replaced every 24 hours. And finally, centrifuging the obtained solid, and drying the solid for 5 to 8 hours, preferably for 8 hours at 150 ℃ in a vacuum oven at 100 to 150 ℃ to prepare a desolventized and activated UiO-66-APS sample.

The preparation of UiO-67-MPPS modified with the inner salt structure MPPS of pyridine propyl sulfonate is taken as an example: ZrCl is treated by ultrasonic waves in a 20ml polytetrafluoroethylene lined reaction kettle ₄ (56mg,0.27mmol) and H ₂ BPDC-MPPS is dissolved in 10ml of ultra-dry DMF for about 5 to 10 minutes, preferably 10 minutes, according to a molar ratio of 1:1 to 1:1.5, preferably 1:1. In the above DMF solutionAdding 35-75 equivalents of acetic acid regulator, preferably 45 equivalents, ultrasonically dispersing for 5 minutes again, and statically storing the reaction kettle in an oven at 80-180 ℃ for 24-72 hours, preferably 120 ℃ for 24 hours. After the temperature of the oven is cooled to room temperature, the solution is centrifugally separated, the obtained white (UiO-67-MPPS) precipitate is washed with DMF and methanol for 2-5 times, preferably 3 times, respectively, and finally soaked in methanol for 48-72 hours, preferably 72 hours, and fresh methanol is replaced every 24 hours. And finally, centrifuging the obtained solid, and drying the solid for 5 to 8 hours, preferably for 8 hours at 150 ℃ in a vacuum oven at 100 to 150 ℃ to prepare a desolventized and activated UiO-67-MPPS sample.

All features or conditions defined herein in the form of numerical ranges or percentage ranges are for brevity and convenience only. Accordingly, the description of numerical ranges or percentage ranges should be considered to have covered and specifically disclosed all possible subranges and individual numerical values within the ranges, particularly integer numerical values. For example, a description of a range of "1 to 8" should be considered to have specifically disclosed all subranges such as 1 to 7, 2 to 8, 2 to 6, 3 to 6, 4 to 8, 3 to 8, and so forth, particularly subranges bounded by all integer values, and individual values such as 1, 2,3, 4,5, 6, 7, 8, and so forth, within the specifically disclosed range. Unless otherwise indicated, the foregoing explanatory methods apply to all matters contained in the entire disclosure, whether broad or not.

If an amount or other value or parameter is expressed as a range, preferred range, or a list of upper and lower limits, it should be understood that all ranges subsumed therein for any pair of that range's upper or preferred value and that range's lower or preferred value, whether or not such ranges are separately disclosed. Further, when a range of numerical values is recited herein, unless otherwise stated, the range is intended to include the endpoints thereof, and all integers and fractions within the range.

In this context, numerical values should be understood to have the same degree of accuracy as the number of significant digits in the numerical value, provided that the invention is capable of achieving the stated purpose. For example, the number 40.0 should be understood to cover a range from 39.50 to 40.49.

The following examples are given by way of illustration of embodiments of the invention and are not to be construed as limiting the invention, and it will be understood by those skilled in the art that modifications may be made without departing from the spirit and scope of the invention. Unless otherwise specified, reagents and equipment used in the following examples are commercially available products.

Example 1

The preparation of the COF-DHz-APS material comprises the following specific implementation steps:

fully grinding and uniformly mixing dimethyl 2-amino terephthalate (3.77g,18mmol) and liquid nitrogen cooled 1, 3-propane sultone (1494ul,18mmol) in a mortar, transferring to a 20ml single-mouth bottle, reacting for 3 hours at 130 ℃, cooling a reaction system after the reaction is finished, washing the obtained dark red solid with acetic acid (17M) for 2-4 times, then washing with acetone twice, and drying to obtain white dimethyl terephthalate powder modified by an ammonium propane sulfonic acid inner salt (APS) structure. And then putting the hydrazine hydrate solution and the hydrazine hydrate solution in absolute ethyl alcohol according to the molar ratio of 1:2, reacting for 36 hours at 80 ℃, centrifuging to obtain a precipitate, and drying the precipitate to obtain yellow hydrazide monomer DHz-APS modified by the APS inner salt structure.

Putting 0.15mmol of DHz-APS and 0.10mmol of 2,4, 6-trihydroxybenzene-1, 3, 5-trimethylaldehyde into a 18ml heat-resistant glass tube, heating a mixed solvent of 2.7ml of mesitylene and 0.3ml of 1, 4-dioxane into the heat-resistant glass tube, adding 128 ul of trifluoroacetic acid, performing ultrasonic dispersion for 10 minutes, performing degassing circulation treatment of three times of freezing, vacuumizing, filling nitrogen and unfreezing in a double-row tube, sealing the glass tube by using flame after vacuumizing, reacting for 5 days at 120 ℃, centrifuging a reaction system after the temperature is reduced to room temperature to obtain reaction precipitate, cleaning the precipitate by using tetrahydrofuran (3 x 10ml) and acetone (3 x 10ml), and drying at 60 ℃ for 8 hours in a nitrogen environment to obtain brick red solid powder.

FIG. 1 is an X-ray powder diffraction diagram of the material COF-DHz-APS obtained according to example 1; stronger characteristic diffraction peaks were shown at 3.55 °, 7.62 ° and 9.73 °, and weaker broad characteristics at 26.66 °, corresponding to (100), (200), (120), (001) planes, respectively. Comparing the experimental data with PXRD curves (including AA stacking and AB stacking) of COF-DHz-APS calculated by a material o studio simulation, the COF-DHz-APS is found to be well matched with the AA stacking mode, and the successful synthesis of the COF-DHz-APS is indicated.

FIG. 2 is an IR spectrum of the material COF-DHz-APS obtained according to example 1, from which it can be seen that after polymerization the characteristic peak for the aldehyde group (1643) of monomeric TFP (trialdehyde phloroglucinol) disappears, indicating complete consumption of the reactants. And C ═ O (1636 cm) appears ^-1 )，C＝C(1616cm ^-1 )，C-N(1258cm ^-1 )，S＝O(1041cm ^-1 ) And characteristic bonds indicate that the material is successfully synthesized and belongs to a covalent organic framework material connected in a beta-ketoenamine manner.

Example 2

The preparation of the COF-DHz-MIMPS material comprises the following specific implementation steps:

dimethyl 2- (imidazolylmethyl) biphenyl-4, 4' -dicarboxylate (2.0g,5.71mmol) was dissolved in acetone, and 1, 3-propanesultone (0.697g,5.71mmol) was slowly added. The solution is stirred for 5 days at room temperature, filtered and precipitated, washed by acetone and dried to obtain white biphenyl-4, 4' -dicarboxylic acid dimethyl ester powder modified by imidazole sulfonate inner salt group MIMPS. Then putting the hydrazine hydrate solution and the hydrazine hydrate solution in absolute ethyl alcohol according to the molar ratio of 1:2, reacting for 36 hours at 80 ℃, centrifuging to obtain a precipitate, and drying the precipitate to obtain the white hydrazine monomer DHz-MIMPS with the modified inner salt structure of the MIMPS.

Putting 0.15mmol of DHz-MIMPS and 0.10mmol of 2,4, 6-trihydroxybenzene-1, 3, 5-trimethylaldehyde into an 18ml heat-resistant glass tube, heating a mixed solvent of 2ml of o-dichlorobenzene and 2.0ml of n-butyl alcohol into the heat-resistant glass tube, adding 400ul of acetic acid, ultrasonically dispersing for 10 minutes, performing degassing circulation treatment of three times of freezing, vacuumizing, filling nitrogen and unfreezing in a double-row tube, sealing the glass tube by using flame after vacuumizing, reacting for 5 days at 130 ℃, centrifuging a reaction system after the temperature is reduced to room temperature to obtain reaction precipitate, cleaning the precipitate by using tetrahydrofuran (3 x 10ml) and acetone (3 x 10ml), and drying for 8 hours at 60 ℃ in a nitrogen environment to obtain brick red solid powder.

FIG. 9 is the X-ray powder diffraction pattern of the material COF-DHz-MIMPS obtained in example 2; in which a strong characteristic diffraction peak is shown at 4.8 deg. and a weak broad characteristic is shown at 22.1 deg., corresponding to (100), (001) planes, respectively. The small angle of peaking indicates the successful synthesis of COF-DHz-MIMPS.

FIG. 10 is an IR spectrum of the material COF-DHz-MIMPS obtained in accordance with example 2, from which it can be seen that after polymerization, the characteristic peak of aldehyde group (1639) of monomeric TFP (trialdehyde phloroglucinol) disappears, indicating complete consumption of the reactant. And C ═ O (1637 cm) appears ^-1 )，C＝C(1618cm ^-1 )，C-N(1280cm ^-1 )，S＝O(1174，104,3cm ^-1 ) Characteristic bonds and the like indicate that the material is successfully synthesized and belongs to a covalent organic framework material connected in a beta-keto enamine manner.

Example 3

COF-DHz-APS·MSA、COF-DHz-APS·ESA、a _g COF-DHz-APS·MSA、 a _g The preparation of COF-DHz-APS.ESA material comprises the following specific implementation steps:

10mg of the COF-DHz-APS material prepared in example 1 was put in a mortar and ground until the powder became fluffy, 1.5ul of MSA or 1.8ul of ESA was quantitatively transferred and dropped into the mortar and continuously ground until it was completely and uniformly absorbed by the COF-DHz-APS material, and the powder was collected, sealed and stored in a dry box to obtain COF-DHz-APS MSA and COF-DHz-APS ESA. Placing on a heating plate, heating at 120-130 deg.C for 3-5min to obtain a glass state product a with fluidity _g COF-DHz-APS MSA and a _g COF-DHz-APS·ESA。

FIG. 3 shows the materials COF-DHz-APS. MSA, COF-DHz-APS. ESA, a obtained according to example 3 _g COF-DHz-APS·MSA，a _g X-ray powder diffractogram of COF-DHz-APS. ESA; the figure shows that the COF-DHz-APS & MSA, COF-DHz-APS & ESA and COF-DHz-APS keep similar diffraction peaks and show good crystallinity, which indicates that the material is structurally stable in organic acid MSA and ESA; after melting by heating, a _g COF-DHz-APS·MSA，a _g The COF-DHz-APS ESA diffraction peak disappeared and an amorphous pattern appeared.

FIG. 4 shows the materials COF-DHz-APS, COF-DHz-AP obtained according to examples 1 and 3Differential scanning calorimetry map of the S MSA; from the observation of the graph (a), it can be seen that the COF-DHz-APS shows no endothermic or exothermic peaks during the heating-cooling cycle at 0 to 180 ℃, indicating that no structural change occurs in the COF-DHz-APS. In the graph (b), the first heating process of COF-DHz-APS & MSA showed an endothermic peak at 145 ℃ combined with the heating phenomenon, and was assigned to the melting temperature T _m . During the second temperature increase a jump of the plateau is seen at 102 ℃ corresponding to the glass transition temperature Tg of the sample. Of note is T _g /T _m ＝102/145＝0.70>2/3，T _g /T _m Represents the glass forming ability and is generally considered to be when T _g /T _m >2/3, the system has a higher glass forming ability, T _g /T _m The larger the viscosity increases faster with decreasing temperature, the more rapidly the molecules are immobilized without being able to migrate to the lowest state, thereby inhibiting the crystallization process.

FIG. 5 shows the materials COF-DHz-APS, a obtained according to examples 1 and 3 _g COF-DHz-APS·MSA， a _g SAXS diagram of COF-DHz-APS. ESA, and reference polycarbonate, silica glass plate; tests have shown that in the q-range 0.025-0.25, the heated material shows a similar tendency to polycarbonate PC, silica glass plates, indicating a _g COF-DHz-APS·MSA，a _g COF-DHz-APS-ESA was in a uniform state, and no particles were present, and the crystal morphology disappeared, and the transition from the crystalline state to the amorphous state was successful.

FIG. 6 shows a material a obtained in example 3 _g A polarized light microscope image of COF-DHz-APS & MSA. Polarized light microscopy is used to identify whether a substance is mono-refractive (isotropic) or birefringent (anisotropic), which is a fundamental property of crystals. When the lens barrel is rotated so that the light is in the orthogonal state, the field of view is dark, if the object to be inspected is anisotropic, the field of view becomes bright, and if the object to be inspected is isotropic, the field of view remains dark. In the figure, under the condition of being orthogonal at 90 degrees, the field of view is dark, which shows that the detected object has isotropy and accords with the characteristics of glassy substances.

FIG. 7 is a graph showing the results ofThe materials COF-DHz-APS, a obtained in examples 1 and 3 _g SEM picture of COF-DHz-APS. MSA; it can be seen from the figure that the COF-DHz-APS powder is in the form of uniform small spheres with a size of about 150 nm; after melting by heating, a _g The surface of COF-DHz-APS & MSA is smooth, flat and free of defects.

FIG. 8 is the COF-DHz-APS material obtained according to examples 1 and 3 _g A conductivity diagram of COF-DHz-APS-MSA; it can be seen from the figure that the electrical conductivity of the heated material is always higher than that of the unheated material, reaching 1.2X 10 at 80 deg.C ^-2 (S·cm ^-1 ) It is shown that the glassy COF material eliminates grain boundary resistance, achieving higher conductivity.

Example 4

COF-DHz-MIMPS·MSA、COF-DHz-MIMPS·ESA、a _g COF-DHz-MIMPS·MSA、 a _g The preparation of the COF-DHz-MIMPS.ESA material comprises the following specific implementation steps:

taking 10mg of the COF-DHz-MIMPS material prepared in example 2, grinding the material in a mortar until the powder is fluffy, then respectively quantitatively transferring 1.2ul MSA or 1.5ul ESA, dripping the material into the mortar, continuously grinding until the material is completely and uniformly absorbed by the COF-DHz-MIMPS material, collecting the powder, sealing and storing in a drying box to obtain COF-DHz-MIMPS & MSA and COF-DHz-MIMPS & ESA. Placing on a heating plate, heating at 120-130 deg.C for 3-5min to obtain a glass state product a with fluidity _g COF-DHz-MIMPS. MSA and a _g COF-DHz-MIMPS·ESA。

FIG. 11 is an optical micrograph of the material COF-DHz-MIMPS. MSA obtained in accordance with examples 2 and 4 before and after heating, (a) shows that the COF-DHz-MIMPS. MSA is in a powder state at room temperature, and (b) shows that a _g COF-DHz-MIMPS. MSA is a transparent bulk solid.

FIG. 12 shows a material a obtained in example 4 _g COF-DHz-MIMPS. MSA.

In the figure, under the condition of being orthogonal at 90 degrees, the field of view is dark, which shows that the detected object has isotropy and accords with the characteristics of glassy substances.

Figure 13 is the material COF-DHz-MIMPS obtained according to examples 2 and 4,a _g a conductivity diagram of COF-DHz-MIMPS. MSA; it can be seen from the figure that the electrical conductivity of the heated material is always higher than that of the unheated material, reaching 2.0X 10 at 30 deg.C ^-2 (S·cm ^-1 ) It is shown that the glassy COF material eliminates grain boundary resistance, achieving higher conductivity.

Example 5

The preparation method of UiO-66-APS comprises the following specific steps:

uniformly mixing 2-amino dimethyl terephthalate and 1, 3-propane sultone according to the ratio of 1:1. Reacting at 130 ℃ for 3 hours, and cooling the reaction system after the reaction is finished. And washing the solid product for 3 times by using 1-17M acetic acid. Centrifugal drying to obtain the dimethyl terephthalate modified by the ammonium propyl propane sulfonic acid inner salt (APS) structure. Then placing the APS and potassium hydroxide into a mixed solution of water and methanol according to a molar ratio of 1:4, reacting for 12 hours at 80 ℃, then dropwise adding hydrochloric acid to acidify until the pH value is 1, filtering to obtain a precipitate, and drying the precipitate to obtain H modified with an APS inner salt structure ₂ BDC-APS。

ZrCl is treated by ultrasonic waves in a 40ml polytetrafluoroethylene lined reaction kettle ₄ (326mg, 1.39mmol) and acetic acid modulator (6ml, 105mmol) were dissolved in 27ml of ultra dry DMF for about 5 minutes. Organic ligand H ₂ BDC-APS (474 mg, 1.39mmol) was dissolved by addition to the clear solution and after approximately 5 minutes of ultrasonic dispersion, it was stored statically in an oven at 120 ℃ for 24 hours. After the oven temperature was cooled to room temperature, the solution was centrifuged, the resulting yellow (UiO-66-APS) precipitate was washed 3 times with DMF and methanol, respectively, and finally soaked in methanol for 72 hours to remove unreacted organic ligand and metal salts and further dried under vacuum at 80 ℃ for 8 hours, and the desolvated activated sample was stored in a glove box.

Example 6

The preparation of the materials UiO-66-APS & MSA, UiO-66-APS & ESA, agUiO-66-APS & MSA and agUiO-66-APS & ESA comprises the following specific implementation steps:

50mg of activated UiO-66-APS was ground in a mortar with 28ul of methanesulfonic acid (MSA) or 28ul of ethanesulfonic acid (ESA) for 2 minutes, and the ground sample was placed in a vacuum oven at 50 ℃ for 6 hours to allow the sample to standThe obtained methanesulfonic acid or the ethanesulfonic acid is evenly diffused and fully mixed in the UiO-66-APS to obtain light yellow solid powder which is respectively named as UiO-66-APS MSA and UiO-66-APS ESA. The process is carried out under the protection of inert gas in a glove box, so as to avoid absorbing water vapor in the air. Heating at 120-150 deg.C for 30min to obtain a fluid vitreous body a _g UiO-66-APS MSA and a _g UiO-66-APS·ESA。

FIG. 14 shows materials UiO-66, UiO-66-APS. MSA, UiO-66-APS. ESA, a obtained in examples 5 to 6 _g UiO-66-APS MSA and a _g Powder X-ray diffraction pattern of UiO-66-APS & ESA; the Bragg diffraction peak positions of UiO-66-APS and UiO-66 are the same, the diffraction of the (1,1, 1) and (2,0,0) crystal planes at the low angles of 7.35 degrees and 8.54 degrees respectively have stronger diffraction, and the ligand (H) with the aminopropanesulfonic acid side chain is shown ₂ BDC-APS) has the same framework structure as the parent UiO-66. After the UiO-66-APS & MSA and the UiO-66-APS & ESA are loaded with methanesulfonic acid or ethanesulfonic acid, the whole diffraction line becomes wide, and due to the relative disorder of guest molecules, the diffraction intensity of the original crystalline MOF is reduced, but the framework lattice structure of the material is still maintained. a is _g UiO-66-APS MSA and a _g UiO-66-APS.ESA is a sample after melt quenching, the original Bragg diffraction peak disappears, and only diffuse scattering signals of a glass state exist, which indicates that the sample after melt quenching is in the glass state.

FIG. 15 is a photomicrograph of the materials UiO-66-APS-MSA and UiO-66-APS-ESA obtained in example 6, taken before and after heating, the (a) and (c) graphs showing that UiO-66-APS-MSA and UiO-66-APS-ESA, respectively, are in the form of powders at room temperature, and the (c) and (d) graphs showing that a _g UiO-66-APS MSA and a _g UiO-66-APS & ESA is a transparent bulk vitreous body.

FIG. 16 Material a obtained in example 6 _g UiO-66-APS & MSA and UiO-66-APS & ESA are used for parallel deviation detection, and the upper and lower analyzers are at 45-degree angle and orthogonal deviation detection under a polarized light microscope. Under the parallel polarization detection position, the upper polarization analyzer and the lower polarization analyzer are parallel to each other, the visual field is brightest, and transparent samples can be seen; the upper and lower analyzers are in 45 degree angle, the visual field is darkThe article also appeared dark; under the orthogonal polarization detection position, the upper analyzer and the lower analyzer are mutually vertical, the visual field is darkest, and the sample darkens along with the slide glass, so that the sample after melting quenching does not have a crystalline structure, but is an isotropic vitreous body.

FIG. 17 shows the materials UiO-66-APS. MSA, UiO-66-APS. ESA, a obtained according to example 6 _g UiO-66-APS MSA and a _g SEM picture of UiO-66-APS. ESA; it can be seen from the figure that the morphology of UiO-66-APS & MSA and UiO-66-APS & ESA is spherical particles, and a is heated and melted _g UiO-66-APS MSA and a _g The surface of UiO-66-APS.ESA is smooth, flat and flawless.

FIG. 18 is a differential scanning calorimetry chart of the materials UiO-66-APS-MSA and UiO-66-APS-ESA obtained in example 6, and it can be seen that UiO-66-APS-MSA is the endothermic peak end point at 138 ℃ in the first heating process, and we attribute it to the melting temperature T in combination with the heating phenomenon _m . The jump of the plateau at 77 ℃ is seen during the second temperature increase, corresponding to the glass transition temperature T of the sample _g . The endothermic peak end point temperature of the UiO-66-APS.ESA sample was 134 ℃ corresponding to the melting temperature T _m The glass transition point T at 48 ℃ is observed during the second temperature rise _g Compared with UiO-66-APS MSA, the method is not obvious, and the viscosity is gradually increased in the sample cooling process, so that the method belongs to a slow phase transition process.

FIG. 19 shows a material a obtained in example 6 _g UiO-66-APS MSA and a _g UiO-66-APS.ESA, MOFs as glassy samples can be obtained by melt quenching and have excellent proton conductivity, a _g UiO-66-APS MSA reaches 10 ℃ at 10 DEG C ^-3 S/cm, and has high potential application value.

Example 7

The preparation method of UiO-67-MPPS comprises the following specific steps:

dimethyl 2- (picolyl) biphenyl-4, 4' -dicarboxylate and 1, 3-propane sultone were dissolved in acetone in a 1:8 molar ratio. Stirring the solution at room temperature for 5 days, filtering and precipitating, washing with acetone, and drying to obtain white MPPS modification of pyridine sulfonate inner salt groupPowder of diphenyl-4, 4' -dicarboxylic acid dimethyl ester. Then placing the MPPS/MPPS mixture and lithium hydroxide into a mixed solution of water and methanol according to a molar ratio of 1:4, reacting for 12 hours at 80 ℃, dropwise adding hydrochloric acid to acidify until the pH value is 1, filtering to obtain a precipitate, and drying the precipitate to obtain H modified with an MPPS inner salt structure ₂ BPDC-MPPS。

ZrCl is treated by ultrasonic waves in a 40ml polytetrafluoroethylene lined reaction kettle ₄ (56mg,0.27mmol) and acetic acid modulator (0.695ml, 13mmol) were dissolved in 10ml of ultra dry DMF for about 5 minutes. Organic ligand H ₂ BPDC-MPPS (119mg, 0.27mmol) was dissolved in the clear solution and after approximately 5 minutes of ultrasonic dispersion, it was stored statically in an oven at 120 ℃ for 24 hours. After the oven temperature was cooled to room temperature, the solution was centrifuged, the resulting white (UiO-67-MPPS) precipitate was washed 3 times with DMF and methanol, respectively, and finally soaked in methanol for 72 hours to remove unreacted organic ligands and metal salts, and further dried under vacuum at 80 ℃ for 8 hours, and the sample after solvent removal activation was stored in a glove box.

Example 8

UiO-67-MPPS. MSA and a _g The preparation method of the UiO-67-MPPS & MSA material comprises the following specific implementation steps:

80mg of activated UiO-67-MPPS and 32ul of methanesulfonic acid are ground in a mortar for 2 minutes, and the ground sample is placed in a vacuum oven at 60 ℃ for 6 hours, so that the methanesulfonic acid is uniformly diffused and fully mixed in the UiO-67-MPPS to obtain white solid powder, and the white solid powder is named as UiO-67-MPPS & MSA. The process is carried out under the protection of inert gas in a glove box, so as to avoid absorbing water vapor in air. Heating at 120-150 deg.C for 30min to obtain a fluid vitreous body a _g UiO-67-MPPS·MSA。

FIG. 21 is an optical microscope photograph of the material UiO-67-MPPS. MSA obtained in example 7 before and after heating, (a) the photograph shows that the UiO-67-MPPS. MSA is in a powder state at room temperature, respectively, (b) the photograph shows that _g UiO-67-MPPS. MSA is transparentA clear bulk glass body.

FIG. 22 is a photograph under an optical microscope of the material UiO-67-MPPS. MSA obtained in examples 7 and 8 before and after heating, and a photograph under parallel and orthogonal polarization detection by a polarizing microscope. Under the parallel deviation detection position, the upper deviation detector and the lower deviation detector are mutually parallel, the visual field is brightest, and transparent samples can be seen; under orthogonal polarization detection, the upper and lower analyzers are perpendicular to each other, the field of view is darkest, and the sample becomes dark as the slide glass.

FIG. 23 shows the material UiO-67-MPPS. MSA, a obtained according to example 8 _g SEM picture of UiO-67-MPPS. MSA; from the figure, UiO-67-MPPS. MSA is seen to be changed into a smooth, flat and blocky plane from particles after being heated and melted.

FIG. 24 is a differential scanning calorimetry diagram of the material UiO-67-MPPS. MSA obtained in example 8, it being observed that during the first heating of UiO-67-MPPS. MSA, an endothermic peak appears at 138.3 ℃ which, combined with the heating phenomenon, we attribute to it the melting temperature T _m . The jump of the plateau was seen at 123.5 ℃ during the second temperature rise, corresponding to the glass transition temperature T of the sample _g 。

Test example 1

COF-DHz-APS、a _g COF-DHz-APS·MSA、COF-DHz-MIMPS、 a _g COF-DHz-MIMPS·MSA、a _g UiO-66-APS·MSA、a _g UiO-66-APS ESA and a _g The specific implementation steps of the measurement of the conductivity of the UiO-67-MPPS & MSA material are as follows:

the ac impedance values of the materials were tested in the range of-60 ℃ to 130 ℃ using the ac impedance test method of the electrochemical workstation, and the resulting Nyquist plot (not shown). Obtaining COF-DHz-APS and a according to a Nyquist map _g The conductivity of COF-DHz-APS-MSA is shown in FIG. 8; obtaining COF-DHz-MIMPS and a _g The electrical conductivity of COF-DHz-MIMPS & MSA is shown in FIG. 13; a is _g UiO-66-APS·MSA、a _g The conductivity of UiO-66-APS.ESA is shown in FIG. 19.

The above description is only for the specific embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present invention, and the changes or substitutions should be covered within the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. An inner salt structure modified covalent organic framework material, which consists of C ₃ Symmetrical aldehyde monomer and C modified with inner salt structure R ₂ The symmetrical hydrazide monomer (DHz-R) is obtained by Schiff base condensation reaction, wherein C ₃ Symmetrical aldehyde monomer and C modified with inner salt structure R ₂ The molar ratio of the symmetrical hydrazide monomers is 2: 3;

wherein R is selected from the following structures:

wherein n is an integer of 2,3, 4 or 5;

preferably, when R is selected from

When n is an integer of 3,4 or 5;

preferably, when R is selected from

When n is an integer of 3,4 or 5;

preferably, when R is selected from

When n is an integer of 3 or 4.

2. A meltable material made from the internal salt structure modified covalent organic framework material of claim 1, wherein the meltable material is formed by reacting the internal salt structure modified covalent organic framework material of claim 1 with a bronsted acid (HA), wherein the bronsted acid is selected from the group consisting of: methanesulfonic acid (MSA), ethanesulfonic acid (ESA), trifluoromethanesulfonic acid (TFA), bistrifluoromethylsulfonylimide (TFSA), phosphoric acid (H) ₃ PO ₄ ) Sulfuric acid (H) ₂ SO ₄ ) Any one of the above;

preferably, in the preparation of the meltable material with the covalent organic framework structure modified by the inner salt structure, the covalent organic framework material modified by the inner salt structure and the Bronsted acid (HA) are ground until the covalent organic framework material and the Bronsted acid are mixed uniformly and completely, then the mixture is heated at a medium and low temperature of 100-250 ℃ for 30-40 min to obtain a melt, and then the melt is cooled and quenched to obtain a glassy product, wherein the molar ratio of the covalent organic framework material modified by the inner salt structure to the HA is 1: 1-1: 10, and preferably 1:1.

3. The method of preparing an inner salt structure modified covalent organic framework material of claim 1, comprising the steps of:

(1) c modified with inner salt structure R ₂ Symmetrical hydrazide monomer (DHz-R)The preparation of (1):

by C ₂ Symmetric amino/imidazole/pyridyl modified hydrazide monomer (DHz) and sultone/dicyanovinolactone ring-opening reaction, or substitution and dealcoholization reaction of amino/imidazole/pyridyl modified hydrazide precursor (DHz) and different alkyl bromo-carboxylic acid esters to obtain C modified with inner salt structure R ₂ A symmetric hydrazide monomer (DHz-R);

modifying the C modified with the inner salt structure R obtained in the step (1) ₂ Symmetrical hydrazide monomer (DHz-R) and corresponding C ₃ Putting symmetrical aldehyde monomers into a mixed solvent, adding a protonic acid catalyst, ultrasonically mixing, vacuumizing, sealing a reaction system, reacting for 3-8 days at 120-130 ℃, cooling the reaction system after the reaction is finished, centrifuging to obtain a precipitate, cleaning, drying and activating the precipitate to obtain a covalent organic framework COF material (COF-DHz-R) modified by an inner salt structure;

preferably, the corresponding inner salt having the structure of R in step (1) is selected from the group consisting of inner sulfamate, inner aminocarboxylate, inner aminodicyanovinate, inner imidazolesulfonate, inner imidazolecarboxylate, inner pyridinesulfonate, inner pyridinecarboxylate and inner pyridinedicyanovinate;

wherein n is an integer of 2,3, 4 or 5;

preferably, whenR is selected from

When n is an integer of 3,4 or 5;

preferably, when R is selected from

When n is an integer of 3,4 or 5;

preferably, when R is selected from

When n is an integer of 3 or 4;

more preferably, the corresponding internal salt of the R structure is selected from APS (aminopropanesulphonate, n ═ 3), ABS (aminobutanesulphonate, n ═ 4), MIMPS (imidazolepropanesulphonate, n ═ 3) and MIMBS (imidazolbutanesulphonate, n ═ 4);

preferably, the mixed solvent in the step (2) is mesitylene and 1, 4-dioxane in a volume ratio of 9:1 or o-dichlorobenzene and n-butanol in a volume ratio of 1: 1;

4. A method of preparing a meltable material as claimed in claim 2, comprising the steps of:

taking a certain amount of the covalent organic framework material (COF-DHz-R) modified by the inner salt structure according to claim 1, grinding the material in a mortar until the powder is fluffy, quantitatively transferring different types of Bronsted acid (HA), continuously grinding the material until the materials are uniformly mixed, heating the material at a medium and low temperature of 100-250 ℃ for 30-40 min to obtain a melt, and cooling and quenching the melt to obtain a glassy product a _g COF-DHz-R·HA；

Preferably, the molar ratio of the COF-DHz-R material to bronsted acid (HA) is between 1:1 and 1:10, preferably 1: 1; the heating temperature is 100-160 ℃; heating for 1-5 min;

5. An inner salt structure modified Metal organic framework material, wherein the Metal organic framework material is formed by Metal ions (M) or Metal clusters (Metal cluster) and dicarboxylic acid organic ligands (L-R) modified by inner salt through coordination bonds to form a porous MOF material;

The metal cluster is selected from [ M ₃ (μ ₃ -O/OH)(COO) ₆ ](M＝Fe ³⁺ ，Cr ³⁺ ，MiL-101，MiL-100)、[MO ₄ (OH) ₂ ](M＝Al ³⁺ DUT-5) and [ M ₆ O ₄ (μ ₃ -OH) ₄ ](M＝Zr ⁴⁺ 、Ti ⁴⁺ Or Hf ⁴⁺ UiO-66/67/68(Zr) or UiO-66/67/68(Ti) or UiO-66/67/68 (Hf));

preferably, when R is selected from

When n is an integer of 3,4 or 5;

preferably, when R is selected from

When n is an integer of 3,4 or 5;

preferably, when R is selected from

When n is an integer of 3 or 4;

6. A meltable material made from the internal salt structure-modified metal organic framework material of claim 5, wherein the meltable material is formed by reacting the internal salt structure-modified metal organic framework material of claim 6 with a bronsted acid (HA), wherein the bronsted acid is selected from the group consisting of: methanesulfonic acid (MSA), ethanesulfonic acid (ESA), trifluoromethanesulfonic acid (TFA), bistrifluoromethylsulfonylimide (TFSA), phosphoric acid (H) ₃ PO ₄ ) Sulfuric acid (H) ₂ SO ₄ ) Any one of the above;

preferably, in the preparation of the meltable material, the metal organic framework material modified by the inner salt structure according to claim 6 and Bronsted acid (HA) are ground until the mixture is uniformly and completely mixed, then the mixture is heated at a medium and low temperature of 100-250 ℃ for 30-40 min to obtain a melt, and then the melt is cooled and quenched to obtain a glassy product, wherein the molar ratio of ligand L-R to HA in the MOF framework material modified by the inner salt structure is 1: 3-1: 10, preferably 1: 4.

7. The method for preparing an inner salt structure modified metal organic framework material according to claim 5, comprising the following steps:

Carrying out a ring-opening reaction on the corresponding reaction precursor amino/pyridyl modified dicarboxylic acid organic ligand and sultone/dicyanovinyl lactone, or carrying out substitution and dealcoholization reaction on the amino/pyridyl modified dicarboxylic acid organic ligand and different alkyl bromo-carboxylic acid esters to obtain a dicarboxylic acid organic ligand (L-R) modified with an inner salt structure R;

(2) preparation of inner salt structure modified metal organic framework MOF-R material:

putting the dicarboxylic acid organic ligand (L-R) modified by inner salt and Metal salt corresponding to the Metal (M) or the Metal cluster (Metal cluster) into N, N-Dimethylformamide (DMF) solvent, adding a protonic acid regulator, ultrasonically mixing, reacting in a polytetrafluoroethylene-lined reaction kettle at the temperature of 80-180 ℃, cooling a reaction system after the reaction is finished, centrifuging to obtain reaction precipitate, cleaning, drying and activating the precipitate to obtain the porous MOF-R material with the inner salt modified structure;

preferably, the organic ligand (L-R) and metal salt ratio in step (2) is 1: 1;

preferably, in step (2), the protonic acid regulator is preferably 75 equivalents of acetic acid based on 1 equivalent of the metal salt;

preferably, in step (2) the metal M is a transition metal ion having a valence of 3 to 4, selected from Fe, Cr, Zr or Hf, and may be selected from Fe ³⁺ 、Cr ³⁺ 、Zr ⁴⁺ Or Hf ⁴⁺ ；

The metal cluster is selected from [ M ₃ (μ ₃ -O/OH)(COO) ₆ ](M＝Fe ³⁺ ，Cr ³⁺ ，MiL-101，MiL-100)、[MO ₄ (OH) ₂ ](M＝Al ³⁺ DUT-5) and [ M ₆ O ₄ (μ ₃ -OH) ₄ ](M＝Zr ⁴⁺ Or Hf ⁴⁺ UiO-66(Zr) or UiO-66 (Hf));

preferably, when R is selected from

When n is an integer of 3,4 or 5;

preferably, when R is selected from

When n is an integer of 3,4 or 5;

preferably, when R is selected from

When n is an integer of 3 or 4.

8. A method of preparing a meltable material as defined in claim 6, comprising the steps of:

grinding a certain amount of the metal organic framework material modified by the inner salt structure according to claim 5 in a mortar until the powder is fluffy, quantitatively transferring the Bronsted acid (HA) into the mortar, continuously grinding until the mixture is uniformly and completely mixed, heating at a medium and low temperature of 100-250 ℃ for 30-40 min to obtain a melt, and cooling and quenching to obtain a glassy product a _g MOF-R·HA；

Preferably, the melting points of the samples are controlled by controlling different amounts of acid, so as to obtain MOF-R-HA with different melting points, wherein the molar ratio of dicarboxylic organic ligands L-R to HA in the MOF-R is between 1:3 and 1:10, preferably 1: 4; the heating temperature is 100-160 ℃;

preferablyThe Bronsted acid (HA) is methanesulfonic acid (MSA), ethanesulfonic acid (ESA), trifluoromethanesulfonic acid (TFA), bis-Trifluoromethanesulfonimide (TFSA), phosphoric acid (H) ₃ PO ₄ ) Sulfuric acid (H) ₂ SO ₄ ) Any one of them.

9. The COF with said internal salt structure modified covalent organic framework structure of claim 1, or the meltable material of claim 2 made from said internal salt structure modified covalent organic framework material of claim 1, or the internal salt structure modified metal organic framework material of claim 6, or the meltable material of claim 7 made from said internal salt structure modified metal organic framework material of claim 6, as ion conducting material (such as H) ⁺ 、Li ⁺ 、Na ⁺ 、K ⁺ Etc.), optical devices, multifunctional glasses, and gas adsorption separation membranes.