CN107540644B - A kind of dicarboxylic acid organic ligand and its preparation method and application - Google Patents

Abstract

The invention discloses a dicarboxylic acid organic ligand, a preparation method and application thereof, wherein the dicarboxylic acid organic ligand is di- (3-formic acid-benzene) furan-2, 5-diamide, and the molecular formula is as follows: c₂₀H₁₄N₂O₇. A zinc complex with the molecular formula { [ Zn (C) { [₂₀H₁₂N₂O₇)(H₂O)₃]·3H₂O·DMF}_nWherein, C₂₀H₁₂N₂O₇For the dicarboxylic acid organic ligand, DMF is N, N-dimethylformamide, N represents an integer greater than 1. The zinc complex can be used for identifying Fe³⁺Or nitrobenzene, and also methylene blue. The invention can be used for identifying Fe with high sensitivity and high selectivity³⁺Or nitrobenzene, and has simple preparation process, easily controlled chemical components, good repeatability and high yield.

Description

A kind of dicarboxylic acid organic ligand and its preparation method and application

technical field

The invention relates to the field of fluorescent probes, in particular to a dicarboxylic acid organic ligand and a preparation method and application thereof.

Background technique

Fluorescent probes have characteristic fluorescence in the ultraviolet-visible-near-infrared region, and their fluorescence properties (such as excitation and emission wavelength, intensity, lifetime, polarization, etc.) can vary with the properties of the environment (such as polarity, refractive index, viscosity, etc.) A class of fluorescent molecules that are sensitive to changes in properties). Fluorescent probes have a wide range of applications in environmental detection and biochemistry. For example, in environmental detection, fluorescence methods using fluorescent probes have better selectivity, higher sensitivity, simpler instruments, and easier operation than traditional environmental detection methods. It has become a fast, sensitive and efficient environmental detection and analysis technology. In the prior art, the preparation of fluorescent probe materials that recognize metal ions or small molecules with high sensitivity and selectivity is an important research topic in the current fluorescent probe field.

SUMMARY OF THE INVENTION

In view of the above deficiencies in the prior art, the present invention provides a dicarboxylic acid organic ligand and a preparation method and application thereof, which can not only be used as a high-sensitivity, high-selectivity identification Fe ³⁺ or nitrobenzene ligand The fluorescent probe has the advantages of simple preparation process, easy control of chemical components, good repeatability and high yield.

The purpose of this invention is to realize through the following technical solutions:

A dicarboxylic acid organic ligand, the dicarboxylic acid organic ligand is bis-(3-formic acid-benzene)furan-2,5-diamide, its molecular formula is: C ₂₀ H ₁₄ N ₂ O ₇ , and its structural formula is as follows:

A method for preparing a dicarboxylic acid organic ligand, comprising: placing both 2,5-furandicarboxylic acid and thionyl chloride in a reaction vessel, heating under reflux for 72 hours, and then evaporating the liquid in the reaction vessel completely , and then add anhydrous dimethylacetamide to the reaction vessel to obtain a brownish-yellow solution; dissolve 3-aminobenzoic acid and 4-(methylamino)pyridine in anhydrous dimethylacetamide, and then add The brownish-yellow solution was stirred and reacted for 36 hours, and then 5% dilute hydrochloric acid was added to obtain a white precipitate; the white precipitate was washed and dried to obtain the dicarboxylic acid described in the above technical scheme. organic ligands;

Among them, the proportional relationship of each raw material is as follows:

A zinc complex whose molecular formula is {[Zn(C ₂₀ H ₁₂ N ₂ O ₇ )(H ₂ O) ₃ ]·3H ₂ O·DMF} _n , wherein C ₂₀ H ₁₂ N ₂ O ₇ is the above For the dicarboxylic acid organic ligand described in the technical solution, DMF is N,N-dimethylformamide, n represents an integer greater than 1, and its crystal structure data is shown in Table 1 below:

Table 1 Crystallographic parameters of {[Zn(C ₂₀ H ₁₂ N ₂ O ₇ )(H ₂ O) ₃ ]·3H ₂ O·DMF} _n

Preferably, the preparation method of the zinc complex is as follows: mixing zinc chloride with the dicarboxylic acid organic ligand described in the above technical scheme, adding it to an aqueous solution of N,N-dimethylformamide, stirring 10 minutes, then placed in an oven at 120°C for 48 hours, and the zinc complex was obtained after cooling; the zinc complex was a colorless bulk crystal;

Among them, the proportional relationship of each raw material is as follows:

Zinc chloride 0.27～2.7g,

0.39-3.9 g of the dicarboxylic acid organic ligand,

N,N-Dimethylformamide 50～500ml.

Preferably, a single crystal diffractometer is used to determine the structure of the zinc complex, and the zinc complex emits blue fluorescence when excited by incident light with a wavelength of 372 nm.

The zinc complexes described in the above technical solutions are used as fluorescent probes for recognizing Fe ³⁺ .

The zinc complex described in the above technical scheme is used as a fluorescent probe for recognizing nitrobenzene.

The zinc complex described in the above technical scheme is used for the adsorption of methylene blue.

It can be seen from the above technical solutions provided by the present invention that the dicarboxylic acid organic ligands provided by the present invention can be made into zinc complexes, and the zinc complexes can identify Fe ³⁺ in various metal ions through the quenching effect , can also achieve good recognition effect for nitrobenzene in many organic solvents, and can also play a good adsorption effect on the cationic dye methylene blue, so the zinc complex can be used as a good fluorescent probe. It can be seen that the present invention can not only be used as a fluorescent probe for identifying Fe ³⁺ or nitrobenzene with high sensitivity and selectivity, but also has a simple preparation process, easy control of chemical components, good repeatability and high yield.

Description of drawings

In order to illustrate the technical solutions of the embodiments of the present invention more clearly, the following briefly introduces the accompanying drawings used in the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can also be obtained from these drawings without any creative effort.

Figure 1 is a schematic diagram of the asymmetric unit of the zinc complex prepared in Example 2 of the present invention.

2 is a schematic diagram of the fluorescence spectrum of the zinc complex prepared in Example 3 of the present invention.

FIG. 3 is a schematic diagram showing the detection of fluorescence properties of zinc complexes in aqueous solutions of different metal ions in Example 3 of the present invention.

FIG. 4 is a schematic diagram showing the detection of the fluorescence properties of the zinc complexes in Example 3 of the present invention in small molecules in different solvents.

5 is a graph showing the adsorption of methylene blue by the zinc complex prepared in Example 3 of the present invention.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present invention.

The dicarboxylic acid organic ligands provided by the present invention and their preparation methods and applications are described in detail below.

Example 1

A dicarboxylic acid organic ligand, the preparation method comprising: placing 10 mmol of 2,5-furandicarboxylic acid and 256 mmol of thionyl chloride into the same 100 ml round-bottomed flask, heating under reflux for 72 hours, and then placing the round-bottomed The liquid in the flask was slowly and completely evaporated, and 20 ml of anhydrous dimethylacetamide was added to the round-bottomed flask to obtain a brownish-yellow solution, which was transferred to a 50 ml constant pressure dropping funnel. Dissolve 21mmol 3-aminobenzoic acid and 2.1mmol 4-(methylamino)pyridine in 50ml anhydrous dimethylacetamide, then slowly drop the brownish-yellow solution in the 50ml constant pressure dropping funnel into it, and The reaction was stirred at room temperature for 36 hours, and then 60ml of dilute hydrochloric acid with a mass fraction of 5% was added to obtain a white precipitate; the solid-liquid was separated, and 15ml of deionized water, 15ml of ethanol and 30ml of 5% of the white precipitate were sequentially used for the white precipitate. Washed with dilute hydrochloric acid, and then dried in a vacuum oven at 60° C. for 24 hours to obtain the dicarboxylic acid organic ligand with a yield of about 72%. Elemental analysis of the dicarboxylic acid organic ligands was carried out, and the obtained results were as follows: theoretical value (%): C, 60.30; H, 3.52; N, 7.04; experimental value (%): C, 59.57; H, 3.39; N, 6.91.

Example 2

A zinc complex, the preparation method comprising: mixing 0.27 g of zinc chloride with 0.39 g of the dicarboxylic acid organic ligand prepared in Example 1 of the present invention, and adding it to 50 ml of N,N-dimethylformamide In the aqueous solution of ZnO, stirred for 10 minutes, then placed in an oven at 120 °C for 48 hours, and cooled to obtain zinc complexes; the zinc complexes were colorless bulk crystals.

2.70°≤θ≤23.20°，从而得到如下结果：本发明实施例2所制得的锌配合物属于正交晶系，空间群皆为Ccca，晶胞参数大约为

α＝90°，β＝90°，γ＝90°。使用Diamond软件绘制该锌配合物的晶体结构，得到如图1所示的最小不对称单元示意图。Specifically, the zinc complex prepared in Example 2 of the present invention with a size of 0.22 × 0.20 × 0.18 mm ³ was selected for single crystal structure analysis, and the single crystal diffraction data was collected by Bruker-AXS SMART APEX2CCD diffractometer, and the single crystal diffraction data was collected with a single-crystal graphite Monochromatic Mokα rays

2.70°≤θ≤23.20°, the following results are obtained: the zinc complex prepared in Example 2 of the present invention belongs to the orthorhombic system, the space group is Ccca, and the unit cell parameter is about

α=90°, β=90°, γ=90°. The crystal structure of the zinc complex was drawn using Diamond software, and the schematic diagram of the minimal asymmetric unit shown in Figure 1 was obtained.

Example 3

A zinc complex, the preparation method comprising: mixing 0.54 g of zinc chloride with 0.78 g of the dicarboxylic acid organic ligand prepared in Example 1 of the present invention, and adding it to 100 ml of N,N-dimethylformamide In the aqueous solution of ZnO, stirred for 10 minutes, then placed in an oven at 120 °C for 48 hours, and cooled to obtain zinc complexes; the zinc complexes were colorless bulk crystals.

Specifically, the following performance tests were carried out on the zinc complex prepared in Example 3 of the present invention:

(1) A single crystal diffractometer was used to perform a fluorescence test on the zinc complex prepared in Example 3 of the present invention, and the incident light wavelength was 372 nm, so that the fluorescence spectrum curve as shown in Figure 2 could be obtained; in Figure 2, the abscissa It is wavenumber (that is, wavelength, and its unit is nm), and the ordinate is intensity (that is, intensity). It can be seen from FIG. 2 that the zinc complex prepared in Example 3 of the present invention emits blue fluorescence under the excitation of incident light with a wavelength of 372 nm.

(2) MCl _x (M=K ⁺ , Co ²⁺ , Cd ²⁺ , Cu ²⁺ , Ba ^{2 +} , Mg ²⁺ , Mn ²⁺ , Ni) of twelve metal ions with a concentration of 1 mmol/L were prepared respectively ²⁺ , Pb ²⁺ , Fe ³⁺ , Al ³⁺ ) aqueous solution was used as the liquid to be tested, and metal chlorides were used to eliminate the interference caused by different anions. Take 3ml of each of the twelve kinds of liquids to be tested and add them to twelve 10ml reaction flasks respectively, and then add 3mg of the zinc complex prepared in Example 3 of the present invention to the twelve reaction flasks respectively, and ultrasonically treat 3～ For 4 minutes, the zinc complex was uniformly dispersed in the liquid to be tested, and then λex=372 nm, which is consistent with the solid fluorescence test, was used as the excitation wavelength, and the slit width was 1.5 nm, and the zinc complexes in the twelve reaction bottles were tested. The fluorescence behavior of the substance is obtained, thereby obtaining the schematic diagram of the fluorescence performance detection of different metal ion aqueous solutions as shown in Figure 3; wherein, the abscissa of Figure 3 represents the wavelength, and the ordinate of Figure 3 represents the relative intensity. It can be seen from Fig. 3 that only the zinc complex in the reaction flask containing Fe ³⁺ solution to be tested has very obvious fluorescence quenching (quenching exceeds 95%), and the change of this fluorescence intensity can be observed with the naked eye, which shows the embodiment of the present invention. 3 The prepared zinc complexes have the ability to recognize Fe ³⁺ as a fluorescent probe.

(3) Ten kinds of liquid small molecules (respectively: water, tetrahydrofuran, chloroform, N,N-dimethylformamide, acetone, cyclohexanone, methanol, nitrobenzene, toluene, and ethyl acetate) were prepared respectively. as the liquid to be tested. Take 3ml of each of the ten liquid small molecules and add them to ten 10ml reaction flasks respectively, and then add 3mg of the zinc complex prepared in Example 3 of the present invention into the ten reaction flasks respectively, and ultrasonically treat them for 3 to 4 minutes. The zinc complexes are uniformly dispersed in the liquid to be tested, and the excitation wavelength of λex=372 nm, which is consistent with the solid fluorescence test, is used as the excitation wavelength, and the slit width is 1.5 nm to test the fluorescence behavior of the zinc complexes in these ten reaction flasks. , thereby obtaining the schematic diagram of fluorescence performance detection in different solvent small molecules as shown in Figure 4; wherein, the abscissa of Figure 4 represents the wavelength, and the ordinate of Figure 4 represents the relative intensity. It can be seen from Figure 4 that only the fluorescence quenching of the zinc complex in the reaction flask containing nitrobenzene is obvious, and it can be seen that the zinc complex prepared in Example 3 of the present invention can be used as a fluorescent probe that specifically recognizes nitrobenzene .

(4) take by weighing 10mg of the zinc complex prepared in Example 3 of the present invention and soak it into 5ml concentration of the ethanolic solution of methylene blue of 20mg/L, and carry out centrifugation to the ethanolic solution of methylene blue at regular intervals, then centrifuge the The obtained supernatant was tested for changes in absorbance using a UV-Vis spectrophotometer, thereby obtaining a graph of the adsorption of methylene blue by zinc complexes as shown in Figure 5; wherein, the abscissa of Figure 5 represents the wavelength, and the ordinate of Figure 5 represents degree of absorption. It can be seen from Figure 5 that the zinc complex prepared in Example 3 of the present invention has a remarkable absorption effect on methylene blue, and nearly 100% of methylene blue is absorbed after standing for 24 hours.

From the above, it can be seen that the embodiment of the present invention can not only be used as a fluorescent probe for identifying Fe ³⁺ or nitrobenzene with high sensitivity and selectivity, but also has a simple preparation process, easy control of chemical components, good repeatability and high yield. .

The above description is only a preferred embodiment of the present invention, but the protection scope of the present invention is not limited to this. Substitutions should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims (8)

1. A zinc complex whose molecular formula is {[Zn(C ₂₀ H ₁₂ N ₂ O ₇ )(H ₂ O) ₃ ]·3H ₂ O·DMF} _n , wherein C ₂₀ H ₁₂ N ₂ O ₇ is an organic ligand of dicarboxylic acid, DMF is N,N-dimethylformamide, and n represents an integer greater than 1; The dicarboxylic acid organic ligand is bis-(3-formic acid-benzene)furan-2,5-diamide, its molecular formula is: C ₂₀ H ₁₄ N ₂ O ₇ , and its structural formula is as follows:

2. zinc complex according to claim 1, is characterized in that, its crystal structure data is as shown in table 1 below: Table 1 Crystallographic parameters of {[Zn(C ₂₀ H ₁₂ N ₂ O ₇ )(H ₂ O) ₃ ]·3H ₂ O·DMF} _n

3. zinc complex according to claim 1 and 2, is characterized in that, its preparation method is: mix zinc chloride and described dicarboxylic acid organic part, and join N,N-dimethyl In the aqueous solution of formamide, stirred for 10 minutes, then placed in an oven at 120 ° C for 48 hours, and the zinc complex was obtained after cooling; Among them, the proportional relationship of each raw material is as follows: Zinc chloride 0.27～2.7g, 0.39-3.9 g of the dicarboxylic acid organic ligand, N,N-Dimethylformamide 50～500ml. 4. The zinc complex according to claim 1 or 2, wherein the zinc complex is a colorless bulk crystal. 5. The zinc complex according to claim 1 or 2, wherein a single crystal diffractometer is used to measure the structure of the zinc complex, and the zinc complex is excited by incident light with a wavelength of 372 nm, and emits blue fluorescent. 6. The zinc complex of any one of the preceding claims 1 to 5 is used as a fluorescent probe recognizing Fe ³⁺ . 7. The zinc complex of any one of the preceding claims 1 to 5 is used as a fluorescent probe for recognizing nitrobenzene. 8. The zinc complex of any of the preceding claims 1 to 5 is used for the adsorption of methylene blue.

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