Hydrogen bond organic framework material as well as preparation method and application thereof

Abstract

According to the hydrogen-bond organic framework material and the preparation method and application thereof, the preparation process is simple, mild and low in cost, the prepared hydrogen-bond organic framework material HOF-BTB-NH2 is one of a few of HOF materials with permanent pore channels, and the porous material has great development potential; the BTB-NH2 linker is connected with carboxyl on an adjacent linker through a hydrogen bond on the carboxyl, a firm 3D porous material is further formed through face-to-face pi-pi stacking interaction between benzene rings, and the 3D porous material is provided with one-dimensional porous channels in the a-axis direction; according to the HOF-BTB-NH2 fluorescent probe, the rigid organic construction molecules enable the HOF-BTB-NH2 fluorescent probe to show excellent fluorescence performance, the porosity and large specific surface area of the HOF-BTB-NH2 material are beneficial to full contact with an analyte and promote interaction with guest molecules, so that the detection sensitivity is improved, and the HOF-BTB-NH2 fluorescent probe has high selectivity due to difference recognition of binding sites. By adopting the fluorescence characteristic of the new material HOF-BTB-NH2, the sensitive and specific detection on the metal ion Cu < 2 + > can be realized.

Description

Technical Field

[0001] The invention relates to the field of hydrogen-bonded organic framework materials, and in particular to a hydrogen-bonded organic framework material and a preparation method and application thereof. Background Art

[0002] Metal ion pollution is of particular concern, such as copper ions, which have attracted much attention due to their potential toxicity. Cu and Fe are important nutrients required for human health and are widely present in industrial wastewater, agricultural discharge and domestic sewage. However, excessive iron or copper will not only damage the living environment of aquatic organisms, but may also cause bioaccumulation and accumulation of toxic substances in the food chain, thus posing a potential threat to human health. Therefore, it is necessary to develop highly sensitive and selective detection methods for Cu. 2+ The method is crucial for environmental protection and health monitoring. Traditional large-scale instrument detection methods are expensive, complicated, and can only be performed in professional analytical laboratories, which is not suitable for real-time monitoring and early warning in emergency situations. In contrast, fluorescence sensing technology has attracted much attention due to its high efficiency, high sensitivity and portability.

[0003] Fluorescence sensors can detect a variety of pollutants such as gases, anions, metal ions and drugs qualitatively and quantitatively by using the change in the intensity or color of the fluorescence signal. Various types of fluorescent probes have been developed, however, many existing fluorescent probes have low sensitivity and complex preparation processes.

[0004] Therefore, it is necessary to develop a fluorescent probe with good fluorescence performance and simple process for accurate detection of Cu in water environment. 2+ This is a problem that needs to be solved urgently. Summary of the invention

[0005] The purpose of the present invention is to overcome the shortcomings and deficiencies of the prior art and to provide a hydrogen bond organic framework material and a preparation method and application thereof.

[0006] The technical solution adopted by the present invention is as follows: The first aspect of the present invention is to provide a method for preparing a hydrogen-bonded organic framework material, comprising the following steps:

[0007] S1. dissolving 2,4,6-tris(4-carboxyphenyl)aniline in an organic solvent to obtain an organic solution;

[0008] S2. Add the antisolvent dropwise into the above organic solution for reaction, let it stand, filter, wash and dry to obtain a hydrogen-bonded organic framework material.

[0009] Preferably, in step S1, the organic solvent includes at least one of tetrahydrofuran, N,N-dimethylformamide and dimethyl sulfoxide.

[0010] Preferably, in step S2, the antisolvent includes at least one of acetonitrile, ethanol and acetone.

[0011] Preferably, the ratio of 2,4,6-tris(4-carboxyphenyl)aniline to antisolvent is (1-5) mg:1 mL.

[0012] Preferably, in step S2, the antisolvent is dripped into the organic solution and stirred to react for 0.2-1 h and then allowed to stand for 24-72 h.

[0013] The second aspect of the present invention is to provide a hydrogen bond organic framework material prepared by the preparation method as described above for use in the removal of metal ions Cu in water. 2+ Detection.

[0014] Preferably, the method comprises the following steps:

[0015] (A) Cu in standard solution 2+ Content detection: The hydrogen bond organic framework material prepared by the above preparation method was dispersed in deionized water to obtain a HOF-BTB-NH2 suspension. Under the excitation of excitation light, the addition of different concentrations of Cu 2+ Fluorescence spectrum of HOF-BTB-NH2 suspension after standard solution sample, a standard working line is established according to the relationship between the concentration of standard solution sample and fluorescence spectrum I0 / I; where I0 represents the original fluorescence of HOF-BTB-NH2 suspension itself, and I represents the concentration of Cu 2+ The fluorescence emitted later;

[0016] (B) Cu in water 2+ Content detection: Detect the fluorescence spectrum of the water body and calculate the Cu content in the water body based on the obtained standard working straight line 2+ The content.

[0017] Preferably, in step (A), the concentration of the HOF-BTB-NH2 suspension is 0.05-0.2 g / L.

[0018] Preferably, in step (A), the wavelength of the excitation light is 381 nm.

[0019] The beneficial effects of the present invention are as follows:

[0020] (1) The preparation process of the present invention is simple, mild and low-cost. The prepared hydrogen-bonded organic framework material HOF-BTB-NH2 is one of the few HOF materials with permanent pores, and the porous material has great development potential; the BTB-NH2 linker is connected to the carboxyl group on the adjacent linker through the hydrogen bond on the carboxyl group, and further forms a solid 3D porous material through the face-to-face π-π stacking interaction between the benzene rings, which has a one-dimensional porous channel along the a-axis direction;

[0021] (2) The rigid organic building molecules of the hydrogen-bonded organic framework material prepared by the present invention make it exhibit excellent fluorescence properties. The porosity and large specific surface area of ​​the HOF-BTB-NH2 material help to fully contact with the analyte and promote the interaction with the guest molecule, thereby improving the detection sensitivity. The differential recognition of the binding site makes it highly selective. The fluorescence properties of the new material HOF-BTB-NH2 can achieve the metal ion Cu 2+ Sensitive and specific detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, without paying creative labor, other drawings obtained based on these drawings still belong to the scope of the present invention.

[0023] Figure 1 is the structural formula of 2,4,6-tris(4-carboxyphenyl)-aniline;

[0024] Figure 2 Experimental synthesis and single crystal simulation for PXRD;

[0025] Figure 3 SEM image of HOF-BTB-NH2;

[0026] Figure 4 HOF-BTB-NH2 was dispersed at a concentration of 4.41×10 -4 Excitation and emission spectra of M in aqueous solution;

[0027] Figure 5 To add different Cu 2+ PL spectra of HOF-BTB-NH2 with different ion concentrations

[0028] Figure 6 Cu 2+ Stern Volmer fitting diagram of ions

[0029] Figure 7 For different Cu 2+ Fitting curve of HOF-BTB-NH2 emission intensity under ion concentration;

[0030] Figure 8 To add different metal ions (Al 3+ , Ca 2+ 、Cd 2+ and Co 2+) concentration of HOF-BTB-NH2 PL spectra;

[0031] Fig. 9 To add different metal ions (Fe 3+ , K + Sc 3+ and Zr 4+ ) concentration of HOF-BTB-NH2. DETAILED DESCRIPTION

[0032] In order to make the objectives, technical solutions and advantages of the present invention more clear, the present invention will be further described in detail below with reference to the accompanying drawings.

[0033] Example 1

[0034] This embodiment provides a method for synthesizing HOF-BTB-NH2 material:

[0035] Weigh 100 mg of raw material (2,4,6-tris(4-carboxyphenyl)-aniline) into a test tube containing 10 mL of tetrahydrofuran solution, transfer the test tube to an ultrasonic machine, and evenly disperse the raw material into the tetrahydrofuran solution. Measure 40 mL of acetonitrile antisolvent into a beaker, put it into a magnetic rotor, transfer the beaker to a stirring table, and set a certain speed for uniform stirring. After preparation, use a rubber dropper to absorb the evenly dispersed solution in the test tube, slowly drip it into a beaker containing 40 mL of acetonitrile antisolvent until it is finished and stir for 30 minutes, move it to a table and let it stand for 2 days, slowly filter out the supernatant, wash it several times with acetonitrile solution, and finally air-dry it to obtain green crystals, namely HOF-BTB-NH2 material.

[0036] The morphology of the HOF-BTB-NH2 material prepared in Example 1 was characterized, and the results were as follows:

[0037] The powder X-ray diffraction (PXRD) pattern of HOF-BTB-NH2 sample was collected by X-ray diffractometer (D8 PHASER), where The scanning rate is 5° / min and the scanning range is 5-40 ° The synthesized HOF-BTB-NH2 was analyzed by PXRD analysis method. Figure 2 The experimentally synthesized peaks are consistent with the single crystal diffraction simulation peaks, confirming the purity of the synthesized sample.

[0038] The size and morphology of the HOF-BTB-NH2 sample were obtained by field emission scanning electron microscopy (FE-SEM), where the setting parameters (acceleration voltage) were 10 kV. The shape and size were further studied by scanning electron microscopy (SEM), such as Figure 3 As shown, the HOF material appears in the form of long blocks with a size of micrometers.

[0039] The fluorescence performance of the HOF-BTB-NH2 material prepared in Example 1 was tested. Figure 4 HOF-BTB-NH2 is dispersed in a concentration of 4.41×10 -4 M Photoluminescence (PL) behavior in water system. HOF-BTB-NH2 exhibits excellent fluorescence emission in water, with a blue light emission of 489 nm, where the excitation wavelength is 381 nm.

[0040] Example 2

[0041] This embodiment provides a hydrogen bond organic framework material on Cu 2+ The application of detection includes the following steps:

[0042] (A) Cu in standard solution 2+ Content detection: 10 mg of the hydrogen-bonded organic framework material prepared in Example 1 was dispersed in 100 mL of deionized water by ultrasonic dispersion to obtain a HOF-BTB-NH2 suspension. At this time, 2 mL of the uniformly dispersed HOF-BTB-NH2 suspension was taken and transferred to a quartz cuvette, and various analytes were gradually added to the cuvette for fluorescence sensing experiments.

[0043] Under 381nm excitation, the addition of different concentrations of Cu 2+ Fluorescence spectrum of HOF-BTB-NH2 suspension after standard solution sample, a standard working line is established according to the relationship between the concentration of standard solution sample and fluorescence spectrum I0 / I; where I0 represents the original fluorescence of HOF-BTB-NH2 suspension itself, and I represents the concentration of Cu 2+ The fluorescence emitted later;

[0044] (B) Cu in water 2+ Content detection: Detect the fluorescence spectrum of the water body and calculate the Cu content in the water body based on the obtained standard working straight line 2+ The content.

[0045] Based on the fluorescence titration method, different concentrations of metal ions Cu were gradually added to the suspension of HOF-BTB-NH2. 2+ , the emission spectrum is as Figure 5 As shown, with the addition of Cu 2+ As the concentration increases, the luminescence intensity gradually quenches. 2+ The quenching efficiency of ions can be quantitatively explained by the Stern-Volmer equation I0 / I=1+KSV[Q], where I0 is the fluorescence intensity of HOF-BTB-NH2 aqueous solution, and I is the fluorescence intensity of Cu 2+ ions, [Q] is the fluorescence intensity of Cu 2+ion concentration. It is worth noting that HOF-BTB-NH2 solution reacts with Cu 2+ ions have a linear relationship. 2+ When the ion concentration was 82.5 μM, the quenching efficiency reached 76.1%.

[0046] HOF-BTB-NH2 in the detection of Cu in water samples 2+ It has higher selectivity and sensitivity.

[0047] The sensing performance of HOF-BTB-NH2 to different metal ions was tested. 2+ When , the PL emission of HOF-BTB-NH2 is significantly quenched ( Figure 5 ), and adding other metal ions, such as Al 3+ , Ca 2+ 、Cd 2+ 、Co 2+ , Fe 3+ , K + Sc 3+ and Zr 4+ When , the PL emission of HOF-BTB-NH2 has no obvious change ( Figure 8 , 9 ). The fluorescence intensity of HOF-BTB-NH2 solution is similar to that of Cu in the low concentration range. 2+ The addition amount of is linearly related. This relationship can be explained by the Stern-Volmer equation. The calculated quenching coefficient Ksv is about 4.1×10 4 M -1 , the detection limit was 2.624μM( Figure 6 , 7 ).

[0048] The above disclosure is only the preferred embodiment of the present invention, which certainly cannot be used to limit the scope of the present invention. Therefore, equivalent changes made according to the claims of the present invention are still within the scope of the present invention.

Claims

1. A method for preparing a hydrogen-bonded organic framework material, characterized in that: The steps include: S1. dissolving 2,4,6-tris(4-carboxyphenyl)aniline in an organic solvent to obtain an organic solution; S2. Add the antisolvent dropwise into the above organic solution for reaction, let it stand, filter, wash and dry to obtain a hydrogen-bonded organic framework material.

2. The method for preparing a hydrogen-bonded organic framework material according to claim 1, characterized in that: In step S1, the organic solvent includes at least one of tetrahydrofuran, N,N-dimethylformamide, and dimethyl sulfoxide.

3. The method for preparing a hydrogen-bonded organic framework material according to claim 1, characterized in that: In step S2, the anti-solvent includes at least one of acetonitrile, ethanol, and acetone.

4. The method for preparing a hydrogen-bonded organic framework material according to claim 1, characterized in that: The ratio of the 2,4,6-tris(4-carboxyphenyl)aniline to the antisolvent is (1-5) mg:1 mL.

5. The method for preparing a hydrogen-bonded organic framework material according to claim 1, characterized in that: In step S2, the antisolvent is dropped into the organic solution, stirred to react for 0.2-1 h, and then allowed to stand for 24-72 h.

6. The hydrogen-bonded organic framework material prepared by the preparation method according to any one of claims 1 to 5 is used for the removal of metal ions Cu in water. 2+ Detection.

7. The use according to claim 6, characterized in that The steps include: (A) Cu in standard solution 2+ Content detection: The hydrogen bond organic framework material prepared by any preparation method of claim 1-5 is dispersed in deionized water to obtain a HOF-BTB-NH2 suspension. Under the excitation of excitation light, the addition of different concentrations of Cu 2 + Fluorescence spectrum of HOF-BTB-NH2 suspension after standard solution sample, a standard working line is established according to the relationship between the concentration of standard solution sample and fluorescence spectrum I0 / I; where I0 represents the original fluorescence of HOF-BTB-NH2 suspension itself, and I represents the concentration of Cu 2+ The fluorescence emitted later; (B) Cu in water 2+ Content detection: Detect the fluorescence spectrum of the water body and calculate the Cu content in the water body based on the obtained standard working straight line 2+ The content.

8. The use according to claim 7, characterized in that: In step (A), the concentration of the HOF-BTB-NH2 suspension is 0.05-0.2 g / L.

9. The use according to claim 7, characterized in that: In step (A), the wavelength of the excitation light is 381 nm.

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