Ionic halogen-based two-dimensional hydrogen bond organic framework material as well as preparation method and application thereof

Abstract

The embodiment of the invention relates to an ionic halogen-based two-dimensional hydrogen bond organic framework material as well as a preparation method and application thereof, and belongs to the technical field of porous organic framework materials. The ionic halogen-based two-dimensional hydrogen bond organic framework material is composed of tri (4-(pyridinium-4-yl) aryl) amine cations and halogen anions, the halogen anions serve as connecting nodes of the tri (4-(pyridinium-4-yl) aryl) amine cations and form triple hydrogen bonds with three peripheral pyridinium groups, and the material is of a two-dimensional honeycomb structure; the residual self-confinement halogen anions in the one-dimensional pore channel of the ionic halogen-based two-dimensional hydrogen bond organic framework material endow the material with strong polarity and strong hydrophilicity, are beneficial to efficient water vapor adsorption, and can be used as a water adsorption material. The preparation method of the ionic halogen-based two-dimensional hydrogen bond organic framework material is simple and efficient to operate.

Description

Technical Field

[0001] The present invention relates to the technical field of porous organic framework materials, and in particular to an ionic halogen two-dimensional hydrogen bond organic framework material and a preparation method and application thereof. Background Art

[0002] Water is an important source of life, however, many regions around the world are facing serious water shortages. Collecting water from the air, or atmospheric water harvesting (AWH), provides a simple and energy-saving strategy to address this crisis. In this context, many porous crystalline solid materials, including zeolites, MOFs, COFs, and organic salts, have been developed and applied to capture and release water. Among them, MOF is a porous network-like crystalline material, usually composed of metal ions coordinated with organic ligands; COF is a similar molecular material formed by covalent bonds between different organic structural units; both materials have permanent porous channels formed by two-dimensional (2D) or three-dimensional (3D) topological structures.

[0003] At present, some MOFs and COFs show high water adsorption capacity and cyclic stability due to their stable porous structures. However, MOFs and COFs have a common disadvantage that their synthesis is usually very time-consuming and requires harsh heat treatment in high-boiling organic solvents. In addition, porous materials need to have high water absorption and small desorption activation energy when used for atmospheric water collection, that is, low water release temperature (Ton), so that they can accommodate enough water molecules, and if the water molecules enclosed in medium-sized nanochannels can show a certain degree of water mobility, it is conducive to low-temperature water desorption. At present, water absorption can be enhanced by adding external hygroscopic salts (such as LiCl or CaCl2) to porous materials, because there is a strong interaction between water molecules and ions. However, these materials may have problems with salt leakage and high Ton values.

[0004] Hydrogen-bonded organic frameworks (HOFs) are an emerging class of porous crystalline materials, which are organic framework materials assembled by hydrogen-bonding interactions between functional molecular building blocks. Due to the dynamic nature of hydrogen bonds, HOFs have high stimulus responsiveness and self-healing properties, making them promising for application in various biomedical, sensing and photonic devices. However, although HOFs are rich in polar functional groups and have high water affinity, the currently reported HOFs have low water absorption and poor water stability, so their application potential in AWH remains to be explored. Summary of the invention

[0005] In view of the above analysis, the embodiments of the present invention aim to provide an ionic halogen two-dimensional hydrogen-bonded organic framework material and a preparation method and application thereof, so as to solve at least one of the problems of existing organic framework materials for water vapor capture, such as harsh preparation conditions, time-consuming preparation process, high dehydration temperature, low water absorption capacity, and poor cycle stability.

[0006] On the one hand, an embodiment of the present invention provides an ionic halogen two-dimensional hydrogen-bonded organic framework material, which is composed of a tri(4-(pyridinium-4-yl)aryl)amine cation and a halogen anion, wherein the halogen anion is a connecting node of the tri(4-(pyridinium-4-yl)aryl)amine cation.

[0007] Furthermore, the halogen anions serve as connecting nodes and are connected with three adjacent tri(4-(pyridin-4-yl)aryl)amine cations through hydrogen bonds to form an ionic halogen two-dimensional hydrogen-bonded organic framework material with a two-dimensional topological structure; three adjacent tri(4-(pyridin-4-yl)aryl)amine cations are connected through halogen anions to form a one-dimensional hexagonal channel, and the inner wall of the channel has self-limiting halogen anions.

[0008] Furthermore, the structural formula of the ionic halogen two-dimensional hydrogen-bonded organic framework material is:

[0009] or

[0010]

[0011] Where n represents the number of double bonds, n≥0; X ﹣ represents a halogen anion.

[0012] Furthermore, the halogen anion is a chloride ion or a bromide ion.

[0013] Furthermore, the ionic halogen-based two-dimensional hydrogen-bonded organic framework material is obtained by the following preparation method: tri(4-(pyridin-4-yl)aryl)amine and a hydrohalic acid aqueous solution are mixed in a solvent, and heated and stirred to completely dissolve them to obtain a mixed solution;

[0014] The mixed solution is cooled and crystallized to obtain crystals;

[0015] The crystals and the solution are separated to obtain an ionic halogen-based two-dimensional hydrogen-bonded organic framework material.

[0016] On the other hand, an embodiment of the present invention provides a method for preparing an ionic halogen two-dimensional hydrogen-bonded organic framework material, which comprises:

[0017] Mixing tri(4-(pyridin-4-yl)aryl)amine and a hydrohalic acid aqueous solution in a solvent, and heating and stirring to completely dissolve them to obtain a mixed solution;

[0018] The mixed solution is cooled and crystallized to obtain crystals;

[0019] The crystals and the solution are separated to obtain an ionic halogen-based two-dimensional hydrogen-bonded organic framework material.

[0020] Furthermore, the molar ratio of tri(4-(pyridin-4-yl)aryl)amine to hydrohalic acid is 1:3 to 1:3000.

[0021] Furthermore, the heating temperature during heating and dissolving is 60 to 100° C., and the heating time is 0.5 to 1 hour.

[0022] Furthermore, when the mixed solution is cooled and crystallized, the cooling crystallization rate is 5 to 50° C. / h.

[0023] Furthermore, the solvent is one of methanol, ethanol, N,N-dimethylformamide, dimethyl sulfoxide, tetrahydrofuran, 1,4-dioxane, and water.

[0024] Furthermore, the prepared ionic halogen two-dimensional hydrogen-bonded organic framework material is composed of tris(4-(pyridinium-4-yl)aryl)amine cations and halogen anions, and the halogen anions are the connecting nodes of the tris(4-(pyridinium-4-yl)aryl)amine cations;

[0025] Preferably, the ionic halogen two-dimensional hydrogen-bonded organic framework material has a one-dimensional hexagonal channel, the inner wall of the channel has a self-limiting halogen anion, and its structural formula is:

[0026] or

[0027]

[0028] On the other hand, an embodiment of the present invention further provides an application of an ionic halogen two-dimensional hydrogen-bonded organic framework material, and the ionic halogen two-dimensional hydrogen-bonded organic framework material prepared by the preparation method in the above embodiment is used for gas adsorption or separation.

[0029] Furthermore, the ionic halogen two-dimensional hydrogen-bonded organic framework material is activated by vacuum heating, and the activated ionic halogen two-dimensional hydrogen-bonded organic framework material is used to adsorb water vapor.

[0030] Furthermore, the heating temperature of the vacuum heating activation is 60 to 150° C., and the activation time is 12 to 72 hours.

[0031] The ionic halogen two-dimensional hydrogen-bonded organic framework material of the present invention and its preparation method and application can achieve at least one of the following beneficial effects:

[0032] 1. The present invention uses halogen anions as connecting nodes to connect tri(4-(pyridin-4-yl)aryl)amine cations to construct a porous two-dimensional hydrogen-bonded organic framework material with a novel structure.

[0033] 2. The two-dimensional hydrogen-bonded organic framework material of the present invention has regular one-dimensional hexagonal channels, which are relatively large and stable. There are residual self-limiting anions in the channels, which enable them to have strong interactions with water molecules, have high water stability and strong hydrophilicity, and thus have a higher water adsorption capacity; at the same time, the present invention expands the pores of the material by introducing larger tripyridyltriphenylamine cations, so that it has a higher water adsorption capacity and a lower water desorption temperature, which is conducive to the effective adsorption and desorption of water vapor.

[0034] 3. The preparation method of the present invention uses halogen anions as connecting nodes to construct porous two-dimensional hydrogen-bonded organic framework materials, which overcomes the lengthy and complex preparation process and structural unpredictability of traditional porous materials. Compared with traditional porous framework materials, the preparation method is simple and efficient, low-cost, green and environmentally friendly, and has strong universality. It can also achieve the preparation of kilogram-level ionic halogen-based two-dimensional hydrogen-bonded organic framework material single crystals while ensuring high purity and high yield.

[0035] 4. The ionic halogen-based two-dimensional hydrogen-bonded organic framework material of the present invention is used as a water vapor adsorption material, has a high adsorption capacity, an extremely low dehydration temperature and good cycle stability, and can be applied to atmospheric water collection devices, etc.

[0036] 5. The ionic halogen two-dimensional hydrogen-bonded organic framework material of the present invention has good water adsorption / desorption performance as a water capture agent, and its maximum adsorption capacity is 0.87 g / g. The adsorption amount does not change significantly after multiple water adsorption / desorption cycles, and has good cycle stability.

[0037] In the present invention, the above-mentioned technical solutions can also be combined with each other to achieve more preferred combination solutions. Other features and advantages of the present invention will be described in the subsequent description, and some advantages can become obvious from the description, or can be understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained through the contents particularly pointed out in the description and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] The drawings are only for the purpose of illustrating particular embodiments and are not to be considered limiting of the present invention. Like reference symbols denote like components throughout the drawings.

[0039] Figure 1 Schematic diagram of the single crystal structure of ionic halogen two-dimensional hydrogen-bonded organic framework materials according to some embodiments of the present invention.

[0040] Figure 2This is a scanning electron microscope image of the ionic halogen two-dimensional hydrogen-bonded organic framework material in Example 1 and Example 3 of the present invention.

[0041] Figure 3 The powder X-ray diffraction spectra of the ionic halogen two-dimensional hydrogen-bonded organic framework materials of Examples 1 to 4 of the present invention are shown.

[0042] Figure 4 The water vapor adsorption / desorption isotherms of the ionic halogen two-dimensional hydrogen-bonded organic framework materials of Examples 1 to 4 of the present invention are shown.

[0043] Figure 5 This is a water adsorption stability curve of the ionic halogen two-dimensional hydrogen-bonded organic framework material of Example 1 of the present invention. DETAILED DESCRIPTION

[0044] In order to make the purpose, technical solutions and advantages of the present invention clearer, exemplary embodiments of the present invention will be described below in conjunction with the accompanying drawings. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. For the sake of clarity and conciseness, not all features of the actual implementation are described in the specification.

[0045] In order to solve the problems of difficulty in preparing existing porous materials, high dehydration temperature, low water absorption capacity, poor cycle stability, etc., an embodiment of the present invention provides an ionic halogen-based two-dimensional hydrogen-bonded organic framework material.

[0046] The ionic halogen two-dimensional hydrogen bond organic framework material of the invention consists of tris(4-(pyridinium-4-yl)aryl)amine cations and halogen anions with C3 symmetry, wherein the halogen anions are connecting nodes of the tris(4-(pyridinium-4-yl)aryl)amine cations.

[0047] The invention uses halogen anions as connection nodes to connect tri(4-(pyridin-4-yl)aryl)amine cations to construct a two-dimensional hydrogen bond organic framework material with a novel structure.

[0048] like Figure 1 As shown, the halogen anion acts as a connecting node and is connected to the pyridinium NH of the three surrounding tri(4-(pyridin-4-yl)aryl)amine cations through hydrogen bonds to form an ionic halogen two-dimensional hydrogen-bonded organic framework material with a two-dimensional topological structure. The three adjacent tri(4-(pyridin-4-yl)aryl)amine cations are connected through the halogen anion to form a one-dimensional hexagonal channel, thereby stabilizing and regularizing the two-dimensional honeycomb porous structure, and making the material have regular one-dimensional hexagonal channels; and due to the introduction of the tri(4-(pyridinium-4-yl)aryl)amine cation, the formed hexagonal channel is larger, which increases the water adsorption capacity of the material, reduces the dehydration temperature, and is conducive to the effective adsorption and desorption of water vapor.

[0049] At the same time, the remaining two-thirds of halogen anions are on the inner wall of the pores, which are self-limited anions and are connected to the cation framework through weak hydrogen bonds. The weak hydrogen bond distance is The pores have strong polarity, can interact strongly with water molecules, have strong hydrophilicity and water stability, are conducive to the adsorption of polar gas molecules such as water vapor, and improve the adsorption capacity.

[0050] It should be noted that Figure 1 The black atoms in the pores of the meso-crystals represent the oxygen atoms in the water molecules. During the preparation process, the crystals will adsorb water from the mixed solution, resulting in the presence of guest water molecules in the pores of the crystal product.

[0051] In some embodiments, the ionic halogen-based two-dimensional hydrogen-bonded organic framework material is a regular hexagonal crystal with high crystallinity and regularity.

[0052] In some embodiments, the structural formula of the ionic halogen two-dimensional hydrogen-bonded organic framework material is: or

[0053] Where n represents the number of double bonds, n≥0; X ﹣ represents a halogen anion.

[0054] It should be noted that, since the ionic halogen-based two-dimensional hydrogen-bonded organic framework material of the present invention has excellent water adsorption performance, water molecules are usually adsorbed in its one-dimensional hexagonal pores; when water is desorbed, the water molecules in its one-dimensional hexagonal pores can be removed. The above two structural formulas represent the structures of the ionic halogen-based two-dimensional hydrogen-bonded organic framework material when water is adsorbed and when water is not adsorbed, respectively.

[0055] Preferably, n is 0 or 1. The raw materials of these two structures are easy to obtain and synthesize.

[0056] In addition, n may also be greater than 1. When n≥2, phenyl groups are connected between adjacent double bonds in the structural formula.

[0057] Preferably, the halogen anion is a chloride ion or a bromide ion. Using chloride ions or bromide ions as halogen anions can obtain an organic framework material with a stable structure as shown in the above structural formula; if fluoride ions are used, the electronegativity of fluoride ions is large and the atomic radius is small, and the material shown in the above structural formula may not be obtained or the formed structure is unstable; and iodide ions cannot form the structure shown in the above structural formula.

[0058] On the other hand, an embodiment of the present invention further provides a method for preparing an ionic halogen two-dimensional hydrogen-bonded organic framework material, characterized in that it comprises:

[0059] Mixing tri(4-(pyridin-4-yl)aryl)amine and a hydrohalic acid aqueous solution in a solvent, and heating and stirring to completely dissolve them to obtain a mixed solution;

[0060] The mixed solution is cooled and crystallized to obtain crystals;

[0061] The crystals and the solution are separated to obtain an ionic halogen-based two-dimensional hydrogen-bonded organic framework material.

[0062] Compared with the preparation of traditional organic framework materials, the preparation method of the hydrogen-bonded organic framework material in the present invention is simple, low-cost, and environmentally friendly. It does not require the high-temperature and high-pressure reaction required for the preparation of traditional organic framework materials (MOF, COF, etc.), and has strong universality, and can achieve large-scale preparation of porous materials.

[0063] Specifically, the reaction formula involved in the preparation process is as follows:

[0064]

[0065] In some embodiments, the molar ratio of tris(4-(pyridin-4-yl)aryl)amine to the hydrohalic acid is 1:3 to 1:3000. For example, the molar ratio of tris(4-(pyridin-4-yl)aryl)amine to the hydrohalic acid can be 1:3, 1:30, 1:300, 1:3000.

[0066] In order to ensure that the yield of the ionic halogen two-dimensional hydrogen-bonded organic framework material is above 90%, the molar ratio of tri(4-(pyridin-4-yl)aryl)amine and hydrohalic acid is set to 1:3-1:3000. Among them, hydrohalic acid is not only used as a reaction raw material, but also can provide an acidic environment for the reaction system. The larger the amount used, that is, the smaller the molar ratio of tri(4-(pyridin-4-yl)aryl)amine and hydrohalic acid, the smaller the pH of the solution, the greater the solubility of the crystal, the larger the size of the crystal precipitated during the cooling crystallization process, and the lower the crystal yield; on the contrary, when the molar ratio is larger, the larger the solution pH, the smaller the solubility of the crystal, the more the crystal in the solution reaches a saturated state, the smaller the size of the crystal precipitated during the cooling crystallization process, and the higher the yield.

[0067] The hydrohalic acid is preferably hydrochloric acid or hydrobromic acid. Thus, the tri(4-(pyridin-4-yl)aryl)amine cation is connected with the chloride ion or bromide ion as the connection node to construct a porous two-dimensional hydrogen-bonded organic framework material, which can ensure that the following is obtained: Figure 1 The structurally stable organic framework material shown.

[0068] In some embodiments, the solvent is one of methanol, ethanol, N,N-dimethylformamide (DMF), dimethyl sulfoxide (DMSO), tetrahydrofuran (THF), 1,4-dioxane, and water. It should be noted that the organic solvents used in the present invention are miscible with water to ensure that the hydrohalic acid aqueous solution can be dissolved in the solvent.

[0069] Preferably, the solvent is water, which makes the preparation process more environmentally friendly.

[0070] In some embodiments, the amount of solvent used is determined based on the amount of tri(4-(pyridin-4-yl)aryl)amine used to ensure that the concentration of the prepared monomer solution is within a predetermined range to ensure that the tri(4-(pyridin-4-yl)aryl)amine can be completely dissolved. Specifically, the concentration of tri(4-(pyridin-4-yl)aryl)amine in the reaction system is 2 to 10 mg / mL, for example, 2 mg / mL, 4 mg / mL, 6 mg / mL, 8 mg / mL, and 10 mg / mL.

[0071] In some embodiments, the heating temperature during heating and dissolving is 60 to 100°C, for example, the heating temperature can be 60°C, 70°C, 80°C, 90°C, 100°C; the heating time is 0.5 to 1h, for example, the heating time can be 0.5h, 0.6h, 0.7h, 0.8h, 0.9h, 1.0h. Among them, the higher the heating temperature during heating and dissolving, the shorter the time required for heating; the lower the heating temperature, the longer the time required for heating. When the heating temperature is too low, the raw materials cannot be completely dissolved, the reaction effect is not good, and the resulting product is impure; too high a reaction temperature is disadvantageous both from a safety perspective and from an energy-saving and environmental protection perspective. The present invention can improve the reaction efficiency while ensuring reaction safety, energy saving and environmental protection by controlling the temperature during heating and dissolving.

[0072] In some embodiments, after the tri(4-(pyridin-4-yl)aryl)amine and the hydrohalic acid are completely dissolved, they need to be slowly cooled to room temperature to crystallize. Specifically, when the mixed solution is cooled and crystallized, the cooling crystallization rate is 5 to 50°C / h. For example, the cooling crystallization rate can be 5°C / h, 10°C / h, 20°C / h, 30°C / h, 40°C / h, and 50°C / h. The cooling crystallization rate is within this range, which can ensure that the resulting product has high crystallinity and phase purity and excellent performance. If the cooling rate is too fast, the crystallinity of the product will be reduced and the purity of the product will be affected; if the cooling rate is too slow, it will take too long and waste time costs.

[0073] After the mixed solution is cooled to room temperature, a large number of crystals are generated in the solution. When separating the crystals and the solution, the crystals can be separated by filtration, centrifugation and the like, and then dried to obtain a large number of single crystals of ionic halogen two-dimensional hydrogen-bonded organic framework materials.

[0074] The preparation method of the ionic halogen two-dimensional hydrogen-bonded organic framework material provided by the embodiment of the present invention is simple and efficient to operate, only requires pure water as a solvent, is green and environmentally friendly, and can also ensure a high purity of ≥98% and a high yield of >90% when the preparation is scaled up to the kilogram level, thus overcoming the lengthy and complicated preparation process, high synthesis cost and structural unpredictability of traditional porous materials. The prepared materials all have a regular two-dimensional porous honeycomb structure. The strategy of constructing a porous hydrogen-bonded organic framework material by introducing halogen anions as connecting nodes in the present invention is universal and efficient.

[0075] An embodiment of the present invention also provides an application method of an ionic halogen two-dimensional hydrogen-bonded organic framework material, wherein the ionic halogen two-dimensional hydrogen-bonded organic framework material prepared by the preparation method of the above embodiment is used for gas adsorption or separation, especially the adsorption and separation of polar gas molecules.

[0076] The ionic halogen two-dimensional hydrogen-bonded organic framework material of the present invention has a stable porous structure and a one-dimensional channel with strong polarity, and can be used as a gas adsorption material. Due to the presence of polar groups in the pores, it is conducive to the attachment of polar gas molecules and can accommodate a large number of guest molecules.

[0077] In some embodiments, when an ionic halogen two-dimensional hydrogen-bonded organic framework material is used as a water vapor adsorbent, the ionic halogen two-dimensional hydrogen-bonded organic framework material is vacuum-heated and activated to eliminate guest solvent molecules in the material pores; and then the activated ionic halogen two-dimensional hydrogen-bonded organic framework material is used to adsorb water vapor.

[0078] The ionic halogen-based two-dimensional hydrogen-bonded organic framework material prepared by the present invention introduces a larger tripyridyltriphenylamine cation, further expanding the pores of the material, so that it has a higher water adsorption capacity and a lower water desorption temperature. There are residual self-limiting halogen anions in the pores of the ionic halogen-based two-dimensional hydrogen-bonded organic framework material, which can generate a strong interaction with water molecules, further improving the water adsorption capacity of the material.

[0079] In some embodiments, the heating temperature of vacuum heating activation is 60-150°C, for example, the heating temperature can be 60°C, 70°C, 80°C, 90°C, 100°C, 110°C, 120°C, 130°C, 140°C, 150°C; the activation time is 12-72h, for example, the activation time can be 12h, 24h, 36h, 48h, 60h, 72h.

[0080] The present invention can ensure that the guest water molecules in the pores of the ionic halogen two-dimensional hydrogen-bonded organic framework material are completely removed by limiting the heating temperature and activation time of vacuum heating activation, which is beneficial to subsequent applications such as gas separation and water vapor adsorption. If the heating temperature is too low or the time is too short, the guest water molecules in the pores will remain, resulting in a decrease in the adsorption amount in the gas adsorption application; if the heating temperature is too high or the time is too long, the framework structure of the material may be destroyed, resulting in structural instability.

[0081] The ionic halogen two-dimensional hydrogen-bonded organic framework material of the embodiment of the present invention is used as a water adsorbent, which has high adsorption capacity and cyclic stability. Its maximum adsorption capacity (the mass of water molecules adsorbed per gram of material) can reach 0.87g / g. The adsorption amount does not change significantly after multiple water adsorption / desorption cycles, and the cyclic stability is high.

[0082] In addition, compared with traditional organic framework materials that require dehydration temperatures of 30 to 200°C to desorb water molecules, the ionic halogen-based two-dimensional hydrogen-bonded organic framework materials of the present invention can desorb water at room temperature. When the ambient humidity is extremely low (for example, the humidity is below 10%), the materials of the present invention can even desorb water at conditions below room temperature.

[0083] The strategy of using halogen anions as connecting nodes to construct porous two-dimensional hydrogen-bonded organic framework materials in the present invention is of great value in the development of efficient water capture agents, and this type of two-dimensional porous material will have very good application prospects in the field of gas adsorption / separation.

[0084] The ionic halogen two-dimensional hydrogen-bonded organic framework material of the present invention and its preparation method and application are further illustrated below with specific examples.

[0085] Example 1

[0086] The ionic halogen-based two-dimensional hydrogen-bonded organic framework material of this embodiment is composed of tris(4-(pyridin-4-yl)phenyl)amine cations and chloride ions with C3 symmetry. The chloride ions are connected to the pyridinium NH of the three surrounding cations through hydrogen bonds as connecting nodes. The hydrogen bond distance is A regular two-dimensional honeycomb porous structure is formed, and the pore width is

[0087] Specifically, the structural formula of the ionic halogen two-dimensional hydrogen-bonded organic framework material of this embodiment is as follows:

[0088]

[0089] The hydrogen-bonded organic framework material of this embodiment was prepared using the following synthetic route:

[0090]

[0091] The preparation method of the ionic halogen two-dimensional hydrogen bond organic framework material is as follows:

[0092] 20 mg of tri(4-(pyridin-4-yl)phenyl)amine and 100 μL of concentrated hydrochloric acid (i.e., the molar ratio is about 1:30) were suspended in 5 mL of distilled water, heated and stirred at 60°C for 0.5 h, and then slowly cooled to room temperature at a cooling crystallization rate of 15°C / h. A large amount of crystals precipitated, and after filtration, vacuum drying was obtained to obtain 22.6 mg of orange rod-shaped crystals represented by structural formula (II-1), with a yield of 92% and a purity greater than 99.5%.

[0093] The obtained product was characterized by hydrogen nuclear magnetic resonance, and the characterization results are as follows:

[0094] 1 H NMR (400 MHz, DMSO-d6): δ8.97-8.89 (d, J = 6.8 Hz, 6H), 8.44-8.36 (d, J = 6.8 Hz, 6H), 8.18-8.09 (d, J = 8.8 Hz, 6H), 7.39-7.30 (d, J = 8.8 Hz, 6H). The characterization results show that the product has the structure shown in structural formula (II-1).

[0095] Example 2

[0096] The structural formula of the ionic halogen two-dimensional hydrogen-bonded organic framework material of this embodiment is as follows:

[0097]

[0098] The two-dimensional hydrogen-bonded organic framework material uses bromide ions as connecting nodes and connects with the pyridinium NH of the three surrounding cations through hydrogen bonds to form a regular two-dimensional honeycomb porous structure with a pore width of

[0099] The preparation method of the above-mentioned ionic halogen two-dimensional hydrogen-bonded organic framework material is as follows:

[0100] 15 mg of tri(4-(pyridin-4-yl)phenyl)amine and 100 μL of concentrated hydrobromic acid (i.e., the molar ratio is about 1:40) were suspended in 5 mL of distilled water, heated and stirred at 60°C for 0.5 h, and slowly cooled to room temperature at a cooling crystallization rate of 10°C / h. A large amount of crystals precipitated, and after filtration, vacuum drying was obtained to obtain 21.5 mg of orange rod-shaped crystals represented by structural formula (II-2), with a yield of 95% and a purity greater than 99.5%.

[0101] During the preparation process, tri(4-(pyridin-4-yl)phenyl)amine reacts with hydrobromic acid as follows:

[0102]

[0103] The obtained product was characterized by hydrogen nuclear magnetic resonance, and the characterization results are as follows:

[0104] 1 H NMR (400MHz, DMSO-d6): δ 8.96 (d, J=6.9Hz, 6H), 8.43 (d, J=7.0Hz, 6H), 8.15 (d, J=8.8Hz, 6H), 7.36 (d, J=8.8Hz, 6H).

[0105] Example 3

[0106] The ionic halogen-based two-dimensional hydrogen-bonded organic framework material of this embodiment is composed of tris(4-((E)-2-(pyridin-4-yl)vinyl)phenyl)amine cations and chloride ions with C3 symmetry, with the chloride ions as connecting nodes connected to the pyridinium NH of the three surrounding cations through hydrogen bonds to form a regular two-dimensional honeycomb porous structure with a pore width of

[0107] The structural formula of the ionic halogen two-dimensional hydrogen-bonded organic framework material of this embodiment is as follows:

[0108]

[0109] The product was prepared by using tri(4-((E)-2-(pyridin-4-yl)vinyl)phenyl)amine and hydrochloric acid according to the following synthetic route:

[0110]

[0111] The preparation method of the ionic halogen two-dimensional hydrogen-bonded organic framework material of this embodiment includes:

[0112] 10 mg of tri(4-((E)-2-(pyridin-4-yl)vinyl)phenyl)amine and 100 μL of concentrated hydrochloric acid (i.e., the molar ratio is about 1:65) were suspended in 10 mL of distilled water, heated and stirred at 80°C for 0.5 h, and slowly cooled to room temperature at a cooling crystallization rate of 10°C / h. A large amount of crystals precipitated, and after filtration, vacuum drying was performed to obtain 11.3 mg of red rod-shaped crystals represented by structural formula (III-1), with a yield of 95% and a purity greater than 99.5%.

[0113] The obtained product was characterized by hydrogen nuclear magnetic resonance, and the characterization results are as follows:

[0114] 1H NMR (400MHz, DMSO-d6): δ8.80 (d, J=6.7Hz, 6H), 8.15 (d, J=6.8Hz, 6H), 7.99 (d, J= 16.3Hz, 3H), 7.76 (d, J=8.8Hz, 6H), 7.45 (d, J=16.3Hz, 3H), 7.18 (d, J=8.7Hz, 6H).

[0115] Example 4

[0116] The structural formula of the ionic halogen two-dimensional hydrogen-bonded organic framework material of this embodiment is as follows:

[0117]

[0118] The pore width of the two-dimensional hydrogen-bonded organic framework material is

[0119] The preparation method of the above-mentioned ionic halogen two-dimensional hydrogen-bonded organic framework material comprises:

[0120] 10 mg of tri(4-((E)-2-(pyridin-4-yl)vinyl)phenyl)amine and 100 μL of concentrated hydrobromic acid (i.e., the molar ratio is about 1:65) were suspended in 8 mL of distilled water, heated with stirring at 80°C for 0.5 h, and slowly cooled to room temperature at a cooling crystallization rate of 8°C / h. A large amount of crystals precipitated, and after filtration, vacuum drying was performed to obtain 13.75 mg of red rod-shaped crystals represented by structural formula (III-2), with a yield of 96% and a purity greater than 99.5%.

[0121] During the preparation process, tri(4-((E)-2-(pyridin-4-yl)vinyl)phenyl)amine reacts with concentrated hydrobromic acid as follows:

[0122]

[0123] The obtained product was characterized by hydrogen nuclear magnetic resonance, and the characterization results are as follows:

[0124] 1 H NMR (400MHz, DMSO-d6): δ8.83 (d, J=6.4Hz, 6H), 8.20 (d, J=6.9Hz, 6H), 8.03 (d, J= 16.2Hz, 3H), 7.78 (d, J=8.7Hz, 6H), 7.48 (d, J=16.2Hz, 3H), 7.19 (d, J=8.4Hz, 6H).

[0125] The ionic halogen two-dimensional hydrogen-bonded organic framework material samples in Example 1 and Example 3 were tested by scanning electron microscope. The test results are as follows: Figure 2As shown. The ionic halogen-based two-dimensional hydrogen-bonded organic framework materials in each embodiment are all regular hexagonal crystals with a length of 0.5 to 2 mm. From the end face of the crystal, it can be seen that the material is a hollow hexagonal morphology, wherein the outer diameter of the crystal in Example 1 is 50 to 100 μm, the inner diameter is 30 to 60 μm, and the outer diameter of the crystal in Example 3 is 1 to 2 μm, and the inner diameter is 0.5 to 0.8 μm.

[0126] The powder X-ray diffraction pattern test of the ionic halogen two-dimensional hydrogen-bonded organic framework material samples in Examples 1 to 4 is as follows: Figure 3 As shown. Figure 3 It can be seen that each sample has a sharp diffraction peak, indicating that each sample has high crystallinity and regularity.

[0127] Application Examples

[0128] The ionic halogen two-dimensional hydrogen-bonded organic framework materials in Examples 1 to 4 are respectively used as water adsorbents, and the specific methods are as follows:

[0129] The ionic halogen two-dimensional hydrogen-bonded organic framework materials prepared in Examples 1 to 4 were respectively evacuated at room temperature for 2 h, and then vacuum-heated at 80° C. and a high vacuum of <0.2 Pa for 24 h to completely eliminate the guest solvent molecules in the material pores and fully activate the material.

[0130] The activated material was used for water vapor adsorption, and the Quantachrome Autosorb IQ instrument was used to measure the volume adsorption / desorption isotherms of water. The water vapor adsorption analysis was performed using a constant temperature water bath with a circulating cooler. In addition, before the measurement, the dried material was evacuated at room temperature for 2 hours, and then evacuated at 80°C and <0.2Pa for 6 hours to avoid the presence of guest solvent molecules in the material pores, which would affect the accuracy of the test results.

[0131] The volume adsorption / desorption isotherms of water of each example sample were measured, as shown in FIG. Figure 4 As shown, the samples in each embodiment have good water adsorption performance, and the maximum adsorption capacities of the samples in Examples 1 to 4 are 0.53 g / g, 0.38 g / g, 0.87 g / g and 0.62 g / g, respectively.

[0132] Take the sample of Example 1 and conduct multiple water vapor adsorption / desorption cycle experiments. Figure 5 As shown, after 10 cycles, the sample can still maintain a high adsorption capacity, and the adsorption capacity has no obvious change in the range of 0.47 to 0.54 g / g, indicating that the material has excellent cycle stability.

[0133] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by any technician familiar with the technical field within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

Claims

1. An ionic halogen two-dimensional hydrogen-bonded organic framework material, characterized in that: The ionic halogen two-dimensional hydrogen-bonded organic framework material is composed of tris(4-(pyridinium-4-yl)aryl)amine cations and halogen anions, wherein the halogen anions are connecting nodes of the tris(4-(pyridinium-4-yl)aryl)amine cations.

2. The ionic halogen two-dimensional hydrogen-bonded organic framework material according to claim 1, characterized in that: The halogen anion serves as a connecting node and is connected with three adjacent tris(4-(pyridin-4-yl)aryl)amine cations through hydrogen bonds to form an ionic halogen two-dimensional hydrogen-bonded organic framework material with a two-dimensional topological structure; Three adjacent tri(4-(pyridin-4-yl)aryl)amine cations are connected by halogen anions to form a one-dimensional hexagonal channel, and the inner wall of the channel has self-limiting halogen anions.

3. The ionic halogen two-dimensional hydrogen-bonded organic framework material according to claim 2, characterized in that: The structural formula of the ionic halogen two-dimensional hydrogen-bonded organic framework material is: Where n represents the number of double bonds, n≥0; X ﹣ represents a halogen anion; Preferably, the halogen anion is a chloride ion or a bromide ion.

4. The ionic halogen two-dimensional hydrogen-bonded organic framework material according to any one of claims 1 to 3, characterized in that: The ionic halogen two-dimensional hydrogen-bonded organic framework material is obtained by the following preparation method: Mixing tri(4-(pyridin-4-yl)aryl)amine and a hydrohalic acid aqueous solution in a solvent, and heating and stirring to completely dissolve them to obtain a mixed solution; Cooling the mixed solution for crystallization to obtain crystals; The crystals and the solution are separated to obtain the ionic halogen two-dimensional hydrogen-bonded organic framework material.

5. A method for preparing an ionic halogen two-dimensional hydrogen-bonded organic framework material, characterized in that: include: Mixing tri(4-(pyridin-4-yl)aryl)amine and a hydrohalic acid aqueous solution in a solvent, and heating and stirring to completely dissolve them to obtain a mixed solution; Cooling the mixed solution for crystallization to obtain crystals; The crystals and the solution are separated to obtain the ionic halogen two-dimensional hydrogen-bonded organic framework material.

6. The preparation method according to claim 5, characterized in that: The molar ratio of the tri(4-(pyridin-4-yl)aryl)amine to the hydrohalic acid is 1:3 to 1:3000; and / or The solvent is one of methanol, ethanol, N,N-dimethylformamide, dimethyl sulfoxide, tetrahydrofuran, 1,4-dioxane and water.

7. The preparation method according to claim 5, characterized in that: The heating temperature during heating and dissolving is 60 to 100° C. and the heating time is 0.5 to 1 hour; and / or When the mixed solution is cooled and crystallized, the cooling crystallization rate is 5 to 50° C. / h.

8. The preparation method according to any one of claims 5 to 7, characterized in that: The prepared ionic halogen two-dimensional hydrogen-bonded organic framework material is composed of tris(4-(pyridinium-4-yl)aryl)amine cations and halogen anions, wherein the halogen anions are connecting nodes of the tris(4-(pyridinium-4-yl)aryl)amine cations; Preferably, the ionic halogen two-dimensional hydrogen-bonded organic framework material has a one-dimensional hexagonal channel, the inner wall of the channel has a self-limiting halogen anion, and its structural formula is:

9. An application of an ionic halogen two-dimensional hydrogen-bonded organic framework material, characterized in that: The ionic halogen two-dimensional hydrogen-bonded organic framework material as described in any one of claims 1 to 4 or the ionic halogen two-dimensional hydrogen-bonded organic framework material prepared by the preparation method as described in any one of claims 5 to 8 is used for gas adsorption or separation.

10. The use according to claim 9, characterized in that: Performing vacuum heating activation on the ionic halogen two-dimensional hydrogen-bonded organic framework material, and using the activated ionic halogen two-dimensional hydrogen-bonded organic framework material to adsorb water vapor; Preferably, the heating temperature of the vacuum heating activation is 60-150° C., and the activation time is 12-72 hours.

Images