Hydrogen bond organic framework material, preparation method and application thereof, and organic amine fluorescence sensor

Abstract

The invention discloses a hydrogen bond organic framework material, a preparation method and application thereof, and an organic amine fluorescence sensor. The organic building unit of the hydrogen bond organic framework material disclosed by the invention is 1, 1, 2, 2-tetra (4-carboxyl phenyl) ethylene; the material is of a triple interpenetrating non-porous structure of a P21 / n space group of a monoclinic system, and the cell parameters are as follows: a is equal to 9.82, b is equal to 14.48, c is equal to 17.04, beta is equal to 92.79 degrees, and the cell volume is 2419.043. Selective adsorption, self-adaptive phase change and fluorescence enhancement response are perfectly combined into the FDU-HHOF-8 material for the first time, opening type, high-selectivity and anti-interference sensing of organic amine is achieved, the limitation that a traditional sensing material is single in function or insufficient in performance is broken through, the worldwide problem of non-specific adsorption of a porous material is solved, and the application prospect is wide. The accuracy of a detection result in a complex environment is ensured; the material is good in light stability and high in photobleaching resistance, the detection limit of NEM is as low as the ppm level, the requirements of actual environment monitoring and industrial safety early warning are met, the preparation process is simple and mild, and application and popularization are convenient.

Description

Technical Field

[0001] This invention relates to the fields of functional materials and chemical sensing technology, and in particular to a hydrogen-bonded organic framework material, its preparation method, applications, and an organic amine fluorescent sensor. Background Technology

[0002] Organic amines are important commercial chemicals with wide applications in numerous fields, including agricultural production, industrial manufacturing, and medical diagnostics. However, organic amines are typical volatile organic compounds, and their vapors can easily be exposed to the environment during improper use. Humans can come into contact with organic amines through inhalation or skin absorption, posing a serious threat to their health. Therefore, developing non-contact organic amine sensing technology with interference resistance has become a key need in this field.

[0003] Currently, gas sensors based on changes in parameters such as conductivity, photoluminescence, capacitance, and fluorescence have been extensively studied. However, existing gas sensing materials generally suffer from severe cross-interference problems when detecting multi-component gas mixtures containing volatile organic compounds, H2O, CO2, and other vapors. Non-porous sensing materials (such as metal oxide semiconductors, conductive polymers, and carbon-based materials) lack selective recognition sites and are highly susceptible to interference from air components, resulting in poor selectivity for organic amines and difficulty in accurately identifying target substances. While porous sensing materials (such as conjugated polymers, metal-organic frameworks, covalent organic frameworks, and zeolites) possess modifiable active sites, their structural characteristics often lead to co-adsorption of analytes and environmental factors, causing signal deviations and false alarms. This non-specific adsorption behavior has become a major bottleneck in the development of non-contact sensing technology.

[0004] Previous studies have found that nonporous adaptive crystals formed by macrocyclic molecules (such as columnar and calixarenes) can capture guest molecules by driving an adaptive phase transition process through weak interactions such as CH···π and π···π. This adaptive phase transition behavior provides a new approach to solving the problem of poor specificity in non-contact sensing.

[0005] Hydrogen-bonded organic frameworks (HOFs) are novel porous materials formed by the self-assembly of organic molecules through intermolecular hydrogen bonds. These materials can be prepared under mild conditions and possess advantages such as high structural predictability, large specific surface area, good processability, and renewability, showing great promise for applications in gas storage and separation, chiral separation, chemical sensing, proton conduction, and catalysis. As novel adaptive materials, HOFs, with their hydrogen bond networks, possess both long-range structural order and dynamic flexibility, demonstrating significant potential in stimulus-response properties for fluorescence sensing and host-guest recognition. Previous studies have shown that carboxylic acid-functionalized HOFs (such as FDU-HOF-3) can capture ammonia through acid-base triggered phase transitions, highlighting the potential of carboxylic acid-based flexible HOFs for the selective adsorption of organic amines with anti-interference capabilities.

[0006] Based on the above background, this invention develops an expandable hydrogen-bonded organic framework material with structural adaptability and applies it to the anti-interference sensing research of organic amines in the air to overcome the shortcomings of existing sensing materials. Summary of the Invention

[0007] The purpose of this invention is to provide a hydrogen-bonded organic framework material, its preparation method, applications, and an organic amine fluorescence sensor, thereby overcoming the technical bottlenecks of poor selectivity and susceptibility to interference in complex environments of existing organic amine sensing materials. To achieve the above objective, this invention provides the following technical solution: The first aspect of this invention provides a hydrogen-bonded organic framework material, the organic building block of which is 1,1,2,2-tetra(4-carboxyphenyl)ethylene; the material has a triple interpenetrating nonporous structure in the monoclinic P21 / n space group, with cell parameters of a=9.82Å, b=14.48Å, c=17.04Å, β=92.79°, and a cell volume of 2419.04Å. 3 .

[0008] According to the hydrogen-bonded organic framework material provided by the present invention, when the material comes into contact with organic amine vapor, it undergoes a single-crystal-to-single-crystal structural transformation, transforming into a porous structure containing one-dimensional channels, accompanied by significant cell volume expansion.

[0009] According to the hydrogen-bonded organic framework material provided by the present invention, the single-crystal-to-single-crystal structural transformation is driven by charge-assisted hydrogen bonds formed between organic amines and carboxyl groups, the organic building blocks of the material, wherein the hydrogen bond length is 2.47-2.79 Å.

[0010] In the hydrogen-bonded organic framework material provided by the present invention, the organic amine is N-ethylmorpholine or triethylamine.

[0011] According to the hydrogen-bonded organic framework material provided by the present invention, the material transforms into a monoclinic crystal system with space group C2 / c after adsorbing N-ethylmorpholine, and the cell volume expands to 4222.75 Å. 3 .

[0012] According to the hydrogen-bonded organic framework material provided by the present invention, the material transforms into a triclinic crystal system after adsorbing triethylamine. The space group has a cell volume expansion to 4462.74 Å. 3 .

[0013] A second aspect of the present invention also provides a method for preparing the hydrogen-bonded organic framework material as described above, the method comprising the following steps: dissolving the organic building blocks in methanol, crystallizing, and obtaining the hydrogen-bonded organic framework material.

[0014] According to the method for preparing hydrogen-bonded organic framework materials provided by the present invention, the crystallization step is carried out at 90°C by solvent evaporation.

[0015] A third aspect of the present invention also provides the application of the hydrogen-bonded organic framework material described above in the specific recognition and sensing of organic amine molecules.

[0016] A fourth aspect of the present invention also provides an organic amine fluorescent sensor, wherein the sensing element of the organic amine fluorescent sensor is prepared using the hydrogen-bonded organic framework material as described above.

[0017] The beneficial effects of this invention are as follows: (1) This invention is the first to perfectly combine selective adsorption, adaptive phase transition and fluorescence enhancement response into FDU-HOF-8 material, realizing "open" type, high selectivity and anti-interference sensing of organic amines, breaking through the limitations of traditional sensing materials with single function or insufficient performance. (2) Excellent anti-interference: Based on the unique acid-base response phase transition mechanism, FDU-HOF-8 material only responds to organic amines with alkalinity, and effectively avoids the influence of water, carbon dioxide and common organic solvents, solving the world problem of non-specific adsorption of porous materials and ensuring the accuracy of detection results in complex environments. (3) Practical sensing performance: FDU-HOF-8 material has good photostability and strong resistance to photobleaching, and can be used stably for a long time; and the detection limit of FDU-HOF-8 material for NEM is as low as 7.43ppm, reaching the ppm level, which can meet the needs of actual environmental monitoring and industrial safety early warning, and has broad application prospects. (4) Simple preparation and testing process: The preparation process of FDU-HOF-8 material is mild and does not require complicated equipment. It can be obtained by dissolving in methanol and evaporating the solvent at 90°C. The process is simple, the steam concentration is controllable, the anti-interference test is easy to operate, and it is easy to promote and apply. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the molecular structure and hydrogen bond connections of the FDU-HOF-8 material of the present invention.

[0019] Figure 2 The diagram shows the structural simulation and hydrogen bond parameters of the interaction between the FDU-HOF-8 material of the present invention and organic amines.

[0020] Figure 3 This is a schematic diagram of the gas path device for the FDU-HOF-8 organic amine sensing experiment of the present invention.

[0021] Figure 4 This is a schematic diagram comparing the working mechanisms of the non-porous and porous sensing materials of the present invention with those of FDU-HOF-8 (expandable HOF).

[0022] Figure 5 This diagram illustrates the mechanism of anti-interference sensing of the hydrogen-bonded organic framework material FDU-HOF-8 in Example 1.

[0023] Figure 6 The image shows the anti-interference adsorption of the hydrogen-bonded organic framework material FDU-HOF-8 in Example 1.

[0024] Figure 7 This is a competitive transmittance diagram of the hydrogen-bonded organic framework material FDU-HOF-8 in Example 1.

[0025] Figure 8 The image shows the electrostatic potential energy diagram of the hydrogen-bonded organic framework material FDU-HOF-8 and the test substance in Example 1.

[0026] Figure 9 This is the formation energy diagram of the hydrogen-bonded organic framework material FDU-HOF-8 in Example 1 with the detection substance and interfering substance.

[0027] Figure 10 The image shows the powder X-ray diffraction pattern of FDU-HOF-8, the hydrogen-bonded organic framework material in Example 1.

[0028] Figure 11 The image shows the powder X-ray diffraction pattern of the anti-interference material of FDU-HOF-8, the hydrogen-bonded organic framework material in Example 1.

[0029] Figure 12 This is a photobleaching test result from the FDU-HOF-8 hydrogen-bonded organic framework sensing platform in Example 1.

[0030] Figure 13 The image shows the response of the FDU-HOF-8 hydrogen-bonded organic framework sensing platform in Example 1 to detect organic amines.

[0031] Figure 14 This is a schematic diagram of the fluorescence response mechanism of the FDU-HOF-8 hydrogen-bonded organic framework sensing platform in Example 1.

[0032] Figure 15 The diagram shows the response of other materials to organic amines in Example 1, which is an anti-interference detection diagram. Detailed Implementation

[0033] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0034] The preparation method of the hydrogen-bonded organic framework material of the present invention includes the following steps: dissolving 1,1,2,2-tetra(4-carboxyphenyl)ethylene organic building units (hereinafter referred to as H4TCPE building units) in methanol to form a homogeneous solution; crystallizing the above solution at 90°C by solvent evaporation to finally obtain a rhombic crystal hydrogen-bonded organic framework material (hereinafter referred to as FDU-HOF-8).

[0035] The basic structural feature of the hydrogen-bonded organic framework material (FDU-HOF-8) of this invention is that the organic building block of FDU-HOF-8 is 1,1,2,2-tetrakis(4-carboxyphenyl)ethylene. In its initial state, FDU-HOF-8 belongs to the monoclinic crystal system, space group P21 / n, and has a triple interpenetrating non-porous structure with the following cell parameters: a = 9.82 Å, b = 14.48 Å, c = 17.04 Å, β = 92.79°, and a cell volume of 2419.04 Å. 3 .

[0036] The microstructure details of the FDU-HOF-8 material are as follows: each H4TCPE building unit is connected to four adjacent units through OH···O resonance-assisted hydrogen bonds between carboxyl dimers, forming a two-dimensional network structure; wherein, the hydrogen bond spacing is in the range of 2.60 Å to 2.79 Å; the two-dimensional network structure is further interwoven to form a triple interlocking structure, thereby effectively stabilizing the entire HOF network.

[0037] The structural transformation characteristic of FDU-HOF-8 material is as follows: upon contact with organic amine vapor, FDU-HOF-8 undergoes a single-crystal-to-single-crystal structural transformation, converting into a porous structure containing one-dimensional channels, accompanied by significant cell volume expansion. This structural transformation is driven by charge-assisted hydrogen bonds formed between the organic amine and the carboxyl groups of the organic building blocks of FDU-HOF-8 material. These hydrogen bonds have a bond length of 2.47–2.79 Å and a bond energy higher than ordinary hydrogen bonds. This process effectively breaks the triple interlocking of the initial structure, inducing significant lattice expansion and achieving a transformation from a non-porous to a porous state, thus exhibiting extremely high selectivity for organic amine molecules.

[0038] The organic amine can be either N-ethylmorpholine (NEM) or triethylamine (TEA). After adsorbing N-ethylmorpholine, the FDU-HOF-8 material transforms into a monoclinic crystal system with space group C2 / c, and the cell volume expands to 4222.75 Å. 3 The expansion rate is 174%; after adsorbing triethylamine, the FDU-HOF-8 material transforms into a triclinic crystal system. The space group has a cell volume expansion to 4462.74 Å. 3 The expansion rate is 185%.

[0039] This invention verifies the anti-interference capability of the hydrogen-bonded organic framework material (FDU-HOF-8) through anti-interference testing. The testing procedure is as follows: See Figure 3 FDU-HOF-8 crystals were placed in the detection bottle; for organic amine vapor detection, the corresponding solvent or organic amine was placed in the vapor generator bottle, and the vapor concentration was precisely controlled by adjusting the flow rates of the two flow meters to ensure the stability and repeatability of the detection conditions; the anti-interference test of hydrogen-bonded organic frameworks was performed.

[0040] The anti-interference test was conducted in an environment with interference from water vapor, carbon dioxide, and / or other organic solvent vapors. The results showed that the fluorescence response of FDU-HOF-8 to N-ethylmorpholine exhibited signal fluctuations of less than 5% under the presence of interfering substances, and its fluorescence "on" effect on NEM remained stable in complex environments. Furthermore, it was able to effectively distinguish organic amines from interfering substances with a discrimination ratio greater than 96.7%; the fluorescence detection limit of FDU-HOF-8 for the organic amine N-ethylmorpholine was 7.43 ppm.

[0041] In summary, the non-porous but expandable hydrogen-bonded organic framework material (FDU-HOF-8) prepared in this invention undergoes a structural transformation upon contact with organic amines due to strong acid-base hydrogen bonding. This transformation results in an adaptive phase transition accompanied by a significant fluorescence enhancement effect, achieving selective capture and fluorescence response. During this process, its unit volume can expand to 174% (N-ethylmorpholine) and 185% (triethylamine). This is the first demonstration that a material can selectively capture organic amines from the air under interference from organic vapors, H2O, and CO2. This dynamic acid-base response mechanism provides fundamental insights into the adaptive structural changes of flexible frameworks, successfully achieving the ability of FDU-HOF-8 to maintain a stable response under various interference conditions, while efficiently and accurately detecting organic amine vapors. This solves the problem that traditional sensing materials struggle to address and broadens the application prospects of scalable hydrogen-bonded organic framework materials.

[0042] The present invention will be further described below with reference to specific embodiments.

[0043] Example 1: Construction of an anti-interference organic amine fluorescence sensing platform based on FDU-HOF-8. It should be noted that all chemical reagents used in this example were purchased from Jilin Zhongke Yanshen Co., Ltd. and Shanghai Titan Technology Co., Ltd.

[0044] Approximately 5 mg of FDU-HOF-8 powder was evenly spread on the bottom of a quartz cuvette to form a fluorescence sensing platform.

[0045] To evaluate its photostability, the cuvette was placed in the sample chamber of a fluorescence spectrometer and continuously irradiated with a 365 nm light source for 600 seconds, with the fluorescence intensity at 455 nm recorded every 10 seconds. The experimental results showed that the fluorescence intensity fluctuated within ±3.3% over 600 seconds, demonstrating that the sensing platform possesses excellent resistance to photobleaching and can operate stably for extended periods.

[0046] To verify the selectivity of FDU-HOF-8 for organic amines, this invention systematically tested its fluorescence response to various interfering substances. The specific steps are as follows: 1.1 Blank baseline measurement: First, place a cuvette containing FDU-HOF-8 into a sealed test chamber with a volume of 50 mL filled with high-purity nitrogen (as carrier gas and background atmosphere), measure and record its initial fluorescence intensity I0 as a blank control.

[0047] 1.2 Interference Tests: Various interferences (including deionized water, saturated CO2 atmosphere, and vapors of methanol, toluene, acetone, n-hexane, tetrahydrofuran, cyclohexane, and n-pentane) were introduced into the test chamber individually. After each test, the chamber was purged with high-purity nitrogen for at least 30 minutes to restore the FDU-HOF-8 to its initial state and ensure that the fluorescence intensity returned to the baseline (initial fluorescence intensity I0) before proceeding to the next set of tests. The fluorescence intensity I in the presence of each interference was recorded, and the fluorescence change rate (I-I0) / I0*100% was calculated.

[0048] 1.3 Target analyte testing: Similarly, vapor containing trace amounts of NEM (concentration of approximately 100 ppm) was introduced into the test chamber, and its fluorescence intensity was recorded.

[0049] 1.4 Data Processing and Analysis: Hierarchical cluster analysis was performed on the fluorescence response data of all substances (NEM and various interfering substances). The results showed that the fluorescence enhancement effect induced by NEM was unique, and its distinction from the interfering substance cluster was greater than 96.7%. The fluorescence change rate caused by all interfering substances did not exceed 3.1%, which fully demonstrates that FDU-HOF-8 has extremely high detection selectivity for organic amines.

[0050] 1.5 Sensitivity and Detection Limit Test: To determine the detection sensitivity and limit of detection of FDU-HOF-8 for NEM, we conducted the following concentration gradient experiments: 1.5.1 Preparation of standard concentration gases: A series of NEM vapor standard gases with known concentrations are prepared by dynamic gas mixing or static volumetric method, covering a concentration range of 0 to 50 ppm.

[0051] 1.5.2 Fluorescence Response Measurement: The FDU-HOF-8 sensing platform was sequentially exposed to NEM vapor of different concentrations for 5 minutes each time to ensure adsorption equilibrium, and the fluorescence intensity value at 455 nm was recorded. Each concentration point was tested three times.

[0052] 1.5.3 Plotting the Standard Curve: A calibration curve was plotted with NEM concentration on the x-axis and fluorescence intensity on the y-axis. This curve exhibited good linearity in the range of 0-50 ppm, with the linear regression equation being y = 4.89171 × 10⁻⁶. -4 x + 4.46596 × 10 -6 linear correlation coefficient R 2 The value was 0.99683. The fluorescence intensity of a blank sample (i.e., in high-purity nitrogen only) was measured 11 times consecutively, and its standard deviation σ was calculated. Following IUPAC recommendations, the detection limit for NEM was calculated to be 7.43 ppm using the formula LOD = 3σ / k (where k is the slope of the standard curve).

[0053] 1.5.4 Comparative Experiment: To highlight the unique performance of FDU-HOF-8, we selected two comparative materials, Zr-TCPE and TPE-Br, for parallel testing. Zr-TCPE and TPE-Br powders were prepared into sensing platforms in the same manner. The two materials were sequentially exposed to NEM, water vapor, and acetone vapor, and their mass changes (adsorption capacity) were monitored using a quartz crystal microbalance, while simultaneously recording changes in fluorescence spectra. The results showed that the selectivity and sensitivity of Zr-TCPE and TPE-Br to organic amines were significantly lower than those of FDU-HOF-8, and they were more susceptible to interference, further demonstrating the superiority of the FDU-HOF-8 material in organic amine sensing.

[0054] Analysis of experimental results: pass Figure 5 The diagram shows the mechanism of anti-interference sensing of FDU-HOF-8, a hydrogen-bonded organic framework material. It shows the structural simulation, hydrogen bonding details and cell volume changes of FDU-HOF-8 before and after adsorption of NEM and TEA, and clarifies the driving mechanism of structural transformation. pass Figure 6 The adsorption diagram of the hydrogen-bonded organic framework material FDU-HOF-8 against interference reflects the differences in adsorption capacity of FDU-HOF-8 for NEM and various interfering substances (such as THF, TOL, H2O, etc.), and intuitively demonstrates its adsorption selectivity. pass Figure 7 The competitive transmission curves of the hydrogen-bonded organic framework material FDU-HOF-8 show the selective adsorption and transmission curves of FDU-HOF-8 to NEM in the presence of H2O, verifying its anti-interference ability. pass Figure 8 Electrostatic potential energy diagrams of the hydrogen-bonded organic framework material FDU-HOF-8 and the detected substances were obtained. The specificity of the interaction between FDU-HOF-8 and organic amine molecules was explained by the analysis of electrostatic potential energy distribution. pass Figure 9 The formation energy diagrams of the hydrogen-bonded organic framework material FDU-HOF-8 with the detection substance and the interfering substance demonstrate from an energy perspective that the stability of the complex formed by FDU-HOF-8 with organic amines is higher than that of the complex formed with the interfering substance, revealing the essential reason for its selectivity. pass Figure 10 The powder X-ray diffraction pattern of the hydrogen-bonded organic framework material FDU-HOF-8 verifies the crystal structure and purity of FDU-HOF-8. pass Figure 11 The powder X-ray diffraction pattern of the hydrogen-bonded organic framework material FDU-HOF-8 in the presence of anti-interference substances shows that the interfering substances do not change the crystal structure of FDU-HOF-8, further proving its anti-interference stability. pass Figure 12 The photobleaching properties of the FDU-HOF-8 hydrogen-bonded organic framework sensing platform were measured, recording the changes in fluorescence intensity of the material under continuous illumination, demonstrating its excellent photostability. pass Figure 13 The response diagram of the FDU-HOF-8 hydrogen-bonded organic framework sensing platform for detecting organic amines includes changes in fluorescence spectra, standard curves, and comparisons of responses to different substances, visually demonstrating its detection performance. pass Figure 14 A schematic diagram of the fluorescence response mechanism of the FDU-HOF-8 hydrogen-bonded organic framework sensing platform clearly shows the process of fluorescence enhancement after the material adsorbs organic amines and undergoes a PET (photoinduced electron transfer) effect. pass Figure 15 The response diagrams of other materials (such as Zr-TCPE and TPE-Br) for the detection of organic amines against interference are compared with the response results of FDU-HOF-8, highlighting the performance advantages of the material of the present invention.

[0055] This invention, through in-situ X-ray diffraction and single-crystal X-ray diffraction experiments in Example 1, determined that the interaction between FDU-HOF-8 and organic amine molecules is not a simple physical adsorption, but a dynamic adaptive phase transition process driven by acid-base reactions, accompanied by charge transfer and hydrogen bond network reconstruction. Compared with the prior art, the hydrogen-bonded organic framework material (FDU-HOF-8) of this invention has the following significant advantages: (1) High performance in a three-in-one: This invention is the first to perfectly combine selective adsorption, adaptive phase transition and fluorescence enhancement response into FDU-HOF-8 material, realizing “open” type, high selectivity and anti-interference sensing of organic amines, breaking through the limitations of traditional sensing materials with single function or insufficient performance. (2) Excellent anti-interference: Based on the unique acid-base response phase transition mechanism, FDU-HOF-8 material only responds to organic amines with alkalinity, and effectively avoids the influence of water, carbon dioxide and common organic solvents, solving the world problem of non-specific adsorption of porous materials and ensuring the accuracy of detection results in complex environments. (3) Practical sensing performance: FDU-HOF-8 material has good photostability and strong resistance to photobleaching, and can be used stably for a long time; and the detection limit of FDU-HOF-8 material for NEM is as low as 7.43ppm, reaching the ppm level, which can meet the needs of actual environmental monitoring and industrial safety early warning, and has broad application prospects. (4) Simple preparation and testing process: The preparation process of FDU-HOF-8 material is mild and does not require complicated equipment. It can be obtained by dissolving in methanol and evaporating the solvent at 90°C. The process is simple, the steam concentration is controllable, the anti-interference test is easy to operate, and it is easy to promote and apply.

[0056] Based on this, the hydrogen-bonded organic framework material (FDU-HOF-8) of the present invention can be effectively applied to the specific recognition and sensing of organic amine molecules.

[0057] In one exemplary embodiment, the hydrogen-bonded organic framework material (FDU-HOF-8) of the present invention is applied to an organic amine fluorescence sensor. Specifically, the sensing element of the organic amine fluorescence sensor is prepared using the hydrogen-bonded organic framework material (FDU-HOF-8) of the present invention.

[0058] In summary, the hydrogen-bonded organic framework material (FDU-HOF-8) and its preparation method and application provided by this invention effectively overcome the technical bottlenecks of existing organic amine sensing materials, and provide a new solution for the high selectivity and anti-interference detection of organic amines. It has important theoretical significance and practical application value in the fields of functional materials and chemical sensing.

[0059] Regarding the embodiments of the present invention, it should also be noted that, without conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other to obtain new embodiments.

[0060] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. The scope of protection of the present invention should be determined by the scope of the claims. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A hydrogen-bonded organic framework material, wherein the organic building block is 1,1,2,2-tetrakis(4-carboxyphenyl)ethylene; characterized in that, The material is a triple interpenetrating non-porous structure of monoclinic P21 / n space group with cell parameters: a = 9.82 A, b = 14.48 A, c = 17.04 A, β = 92.79°, cell volume of 2419.04 A 3 .

2. The hydrogen-bonded organic framework material according to claim 1, characterized in that, When the material comes into contact with organic amine vapor, it undergoes a single-crystal-to-single-crystal structural transformation, transforming into a porous structure containing one-dimensional channels, accompanied by significant cell volume expansion.

3. The hydrogen-bonded organic framework material according to claim 2, characterized in that, The single-crystal-to-single-crystal structural transformation is driven by charge-assisted hydrogen bonds formed between the organic amine and the carboxyl group of the organic building unit of the material, with a bond length of 2.47-2.79 Å.

4. The hydrogen-bonded organic framework material according to claim 3, characterized in that, The organic amine is N-ethylmorpholine or triethylamine.

5. The hydrogen-bonded organic framework material according to claim 4, characterized in that, After adsorbing N-ethylmorpholine, the material transforms into a monoclinic crystal system with space group C2 / c, and the cell volume expands to 4222.75 Å. 3 .

6. The hydrogen-bonded organic framework material according to claim 4, characterized in that, The material transforms into a triclinic crystal system after adsorbing triethylamine. The space group has a cell volume expansion to 4462.74 Å. 3 .

7. A method for preparing a hydrogen-bonded organic framework material as described in any one of claims 1 to 6, characterized in that, The preparation method includes the following steps: dissolving the organic building block in methanol, crystallizing, and obtaining a hydrogen-bonded organic framework material.

8. The preparation method according to claim 7, characterized in that, The crystallization step is carried out at 90°C by solvent evaporation.

9. The application of a hydrogen-bonded organic framework material as described in any one of claims 1 to 6 in the specific recognition and sensing of organic amine molecules.

10. An organic amine fluorescence sensor, characterized in that, The sensing element of the organic amine fluorescent sensor is prepared using the hydrogen-bonded organic framework material as described in any one of claims 1 to 6.

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