One-dimensional Zn-CP fluorescent probe materials, their preparation methods, and their recognition of CrO4 2- and Cr2O7 2- Application

Abstract

This invention belongs to the field of fluorescent sensing materials, specifically relating to a one-dimensional Zn-CP fluorescent probe material, its preparation method, and its ability to recognize CrO4. 2‑ and Cr2O7 2‑ Applications. The structural formula of this Zn-CP fluorescent probe is: [Zn(L)(H2O)2] n In the structural formula, L 2‑ It is the (4-(3-methyl-4-carboxy-1H-pyrazole)benzoate anion; in Z Monoclinic system with a density of 4 P twenty one / c Crystallization within a space group. The one-dimensional Zn-CP fluorescent probe material preparation method of this invention is simple, has high yield, low cost, and good fluorescence stability. It is effective in detecting CrO4 in water. 2‑ and Cr2O7 2‑ It exhibits excellent recognition performance, as well as good stability and recyclability, and is environmentally friendly.

Description

Technical Field

[0001] This invention belongs to the field of fluorescent sensing materials, and specifically relates to a one-dimensional Zn-CP fluorescent probe material, its preparation method, and its ability to recognize CrO4. 2- and Cr2O7 2- Applications. Background Technology

[0002] In recent years, the threat posed by chemical pollutants to the ecological environment and human health has intensified, attracting widespread attention. Water pollution, particularly industrial wastewater pollution, has been a major concern. Oxygen-containing anions are a primary component of industrial wastewater pollutants and are closely related to daily life. Many oxyanions are harmful to the human body, especially Cr(VI)-containing oxyanions (CrO4). 2- Cr2O7 2- Oxygen anions (AOA) are potent carcinogens and mutagens, causing allergic reactions, genetic defects, and cancer. Therefore, the selective, rapid, and sensitive detection of low concentrations of AOA anions is a pressing issue. Years of research have revealed numerous methods for analyzing and detecting these ions, such as chromatography, mass spectrometry, spectrophotometry, infrared spectroscopy, and ultraviolet spectroscopy. However, the high cost of these instruments and the complex operating procedures severely limit their practical application. Therefore, there is still a desire to find other simpler detection methods. Fluorescence sensing primarily achieves qualitative and quantitative analysis by quenching or enhancing the fluorescence of the probe material after the addition of the analyte. Moreover, it possesses numerous advantages, including simple operation, portability, real-time detection, low cost, high selectivity, and high sensitivity, and is widely used in environmental monitoring, biotechnology, food safety, chemical production, and clinical medicine.

[0003] Coordination polymers (CPs) are a class of multifunctional materials composed of metal ions or metal clusters and organic ligands. They have attracted considerable attention in recent years due to their advantages such as large specific surface area, high crystallinity, ease of preparation, and excellent photoelectric and chemical sensing capabilities. Compared with traditional fluorescent sensing materials, using CPs as fluorescent probe materials is simpler to prepare, lower in cost, less polluting, more stable, more sensitive, and has a faster response, enabling rapid and effective detection of low-concentration pollutants in complex compositions. Summary of the Invention

[0004] The purpose of this invention is to provide a one-dimensional Zn-CP fluorescent probe material, its preparation method, and a method for recognizing Cr(VI) oxyanions (CrO4). 2- Cr2O7 2- Applications of this Zn-CP fluorescent probe material for detecting CrO4 in water. 2- and Cr2O7 2-The detection exhibits high sensitivity, stability, anti-interference ability, and recyclability, and the preparation method is simple, low-cost, and environmentally friendly.

[0005] The technical solution adopted in this invention is as follows:

[0006] A Zn-CP fluorescent probe material with the molecular formula: [Zn(L)(H2O)2] n .

[0007] Among them, L 2- It is a divalent anion of (4-(3-methyl-4-carboxy-1H-pyrazole)benzoate; n is an integer greater than or equal to 1.

[0008] This Zn-CP fluorescent probe material in Z = 4 monoclinic crystal system P twenty one / c Crystallization in space group, unit cell parameters: a =13.945(3) Å, b = 7.6602(15) Å, c = 12.437(3) Å, α = 90°, β = 107.916(7)°, γ = 90°.

[0009] like Figure 2 As shown, in this Zn-CP fluorescent probe material (L1) 2- The N atom on the pyrazole ring in the ligand ion is connected to the carboxylate group of the pyrazole ring via a bidentate bridge, which bridges Zn1 and Zn1D to form the [Zn2(-CO2)2] ring. The carboxylate group of the ligand ion connected to the benzene ring coordinates with Zn1A via a monodentate bridge, forming a one-dimensional chain structure.

[0010] The preparation method of the above-mentioned Zn-CP fluorescent probe material includes the following steps:

[0011] A1. At room temperature, soluble zinc salts are dissolved in H2O and stirred to obtain a colorless and clear solution, which is the zinc salt solution; a mixed solution of H2O and DMF is added dropwise to the surface of the zinc salt solution to form a mixed solution layer of H2O and DMF.

[0012] A2. Dissolve the H2L ligand and base in a mixed solvent of H2O and DMF and stir to obtain a pale yellow clear solution, which is the ligand solution; add the ligand solution dropwise to the surface of the aforementioned mixed solution of H2O and DMF to make it present a three-layer state;

[0013] A3. After sealing and allowing the solution to diffuse statically, and after the product is formed in the mixed solution layer of H2O and DMF, the product is filtered, washed and dried to obtain the Zn-CP fluorescent probe material.

[0014] Preferably, the molar ratio of the soluble zinc salt to the H2L ligand is 1:1 to 1.5. The soluble zinc salt is any one or more of zinc sulfate, zinc acetate, zinc nitrate, and zinc chloride.

[0015] Preferably, the molar ratio of the H₂L ligand to the base is 1:1.5 to 2.5. The base is any one or more of KOH or NaOH.

[0016] Preferably, the volume ratio of the zinc salt solution, the mixed solution of H2O and DMF, and the ligand solution is 2:4:3.

[0017] Preferably, the volume ratio of H2O to DMF in the mixed solution of H2O and DMF is 1~2:2.

[0018] Preferably, the static diffusion temperature is room temperature, and the static diffusion time is 2 to 7 days; more preferably, the static diffusion time is 2 to 3 days.

[0019] Preferably, the washing process involves first washing with deionized water, then washing with DMF, and finally washing with ether.

[0020] Furthermore, the preparation method of the above-mentioned H2L ligand, namely (4-(3-methyl-4-carboxy-1H-pyrazole)benzoic acid, includes the following steps:

[0021] B1. 2-Ethoxymethylene-3-oxo-butyrate ethyl ester was heated and refluxed with p-carboxyphenylhydrazine in isopropanol until the reaction was complete. The brown solid powder was collected, washed and dried to obtain 1-(4-carboxyphenyl)-4-methyl-1h-pyrrole-3-carboxylic acid ethyl ester.

[0022] B2. The brown solid powder 1-(4-carboxyphenyl)-4-methyl-1h-pyrrole-3-carboxylic acid ethyl ester obtained in step B1 was refluxed with NaOH until the reaction was complete. Then, hydrochloric acid was added dropwise until the solid precipitated. The solid was filtered, washed, and dried to obtain the organic ligand 4-(3-methyl-4-carboxy-1H-pyrazole)benzoic acid.

[0023] Preferably, the molar ratio of ethyl 2-ethoxymethylene-3-oxo-butyrate to p-carboxyphenylhydrazine in step B1 is 1-1.1:1-1.1;

[0024] Preferably, the washing in step B1 is performed using petroleum ether;

[0025] Preferably, the drying method described in step B1 is room temperature drying;

[0026] Preferably, the molar ratio of ethyl 1-(4-carboxyphenyl)-4-methyl-1H-pyrrole-3-carboxylate to NaOH in step B2 is 1-1.1:2-2.1;

[0027] Preferably, the heating reflux temperature in step B2 is 90 ℃~110 ℃;

[0028] Preferably, the HCl concentration in step B2 is 5–7 M;

[0029] Preferably, the washing in step B2 is performed using deionized water;

[0030] Preferably, the drying method described in step B2 is vacuum drying at a temperature of 80°C for 8 hours.

[0031] This invention also provides a Zn-CP fluorescent probe material prepared according to the above preparation method as a fluorescent sensor in CrO4. 2- and Cr2O7 2- Applications in ion detection.

[0032] Specifically, the steps include the following:

[0033] S1. Grind the Zn-CP fluorescent probe material, disperse it in deionized water, and sonicate it to form a suspension. Then measure its fluorescence excitation, emission intensity and fluorescence recognition performance.

[0034] S2. Prepare the anion aqueous solution to be tested. Add the prepared anion aqueous solution to the Zn-CP material suspension obtained in step S1 using a pipette, and measure its fluorescence emission intensity to obtain the fluorescence response intensity of Zn-CP and CrO4. 2- or Cr2O7 2- The concentration relationship is used to test the CrO4 content in the sample. 2- and Cr2O7 2- The concentration.

[0035] Preferably, the Zn-CP material described in step S1 is ground in a ball mill for 10 to 20 minutes to a mesh size of 60 to 80.

[0036] Preferably, the ultrasonic dispersion time in step S1 is 0.5–1.5 h, and the power is 50–70 Hz.

[0037] Preferably, in step S1, the mass ratio of Zn-CP material to water in the Zn-CP material suspension is 1:600-700.

[0038] The Zn-CP fluorescent probe material provided by this invention has good fluorescence intensity and stability, and can be used for qualitative and quantitative detection of Cr2O7 in water. 2-and CrO4 2- Anions. Compared with existing detection methods, it exhibits superior sensitivity, selectivity, anti-interference ability, and recyclability. Attached Figure Description

[0039] Figure 1 The NMR spectrum of (4-(3-methyl-4-carboxy-1H-pyrazole)benzoic acid (H2L) is shown.

[0040] Figure 2 A one-dimensional chain-like schematic diagram of a Zn-CP fluorescent probe material;

[0041] Figure 3 X-ray powder diffraction pattern of Zn-CP fluorescent probe material;

[0042] Figure 4 Thermogravimetric curve of Zn-CP fluorescent probe material;

[0043] Figure 5 The fluorescence excitation and emission spectra of the Zn-CP fluorescent probe material are shown.

[0044] Figure 6 Comparison of fluorescence intensity of Zn-CP fluorescent probe material under different interfering anions;

[0045] Figure 7 Zn-CP fluorescent probe material for different concentrations of Cr2O7 2- Fluorescence response spectrum of ions;

[0046] Figure 8 Zn-CP fluorescent probe material for different concentrations of CrO4 2- Fluorescence response spectrum of ions;

[0047] Figure 9 For the detection of Cr2O7 using Zn-CP fluorescent probe materials 2- The post-ion cycling response diagram shows that the horizontal bars represent the initial luminescence intensity, and the vertical bars represent the intensity after the addition of Cr2O7. 2- The intensity of ion emission after ionization, with the horizontal axis representing the number of cycles;

[0048] Figure 10 For the detection of CrO4 by Zn-CP fluorescent probe material 2- The post-ion cycling response diagram shows that the horizontal bars represent the initial luminescence intensity, and the vertical bars represent the intensity after the addition of CrO4. 2- The intensity of ion emission is represented on the x-axis, which is the number of cycles. Detailed Implementation

[0049] The present invention will be further described below with reference to specific embodiments and accompanying drawings.

[0050] Synthetic route of ligand 4-(3-methyl-4-carboxy-1H-pyrazole)benzoic acid:

[0051]

[0052] Synthesis of organic ligand H2L:

[0053] Ethyl 2-ethoxymethylene-3-oxo-butyrate (3.4 mL, 30 mmol) was reacted with p-carboxyphenylhydrazine (4.56 g, 30 mmol) and 80 mL isopropanol (IPA) under reflux. After the reaction was observed to be complete by TLC, the solvent was removed by rotary evaporation, and the product was washed with petroleum ether, dried, and collected to obtain ethyl 1-(4-carboxyphenyl)-4-methyl-1H-pyrrole-3-carboxylic acid as a brown solid powder. Ethyl 1-(4-carboxyphenyl)-4-methyl-1H-pyrrole-3-carboxylate (6.86 g, 25 mmol), NaOH (2.00 g, 50 mmol), and H2O (100 mL) were heated under reflux and observed on TLC until the reaction was complete. After the solution cooled, 6 M HCl solution was added dropwise while stirring continuously until a solid precipitated. The solid was filtered, washed with an appropriate amount of deionized water, and dried under vacuum at 80 °C for 8 h to obtain the organic ligand H2L, with a yield of 94%. Figure 1 The image shows the H NMR spectrum of the ligand H2L. 1 H NMR (500 MHz, DMSO-d6): δ 8.10 (d, 2H, Ar-H), 8.02 (s, 1H, C3HN2-H), 7.70 (d, 2H, Ar-H), 2.57 (s, 3H,CH3-H).

[0054] It should be noted that the purpose of this invention can also be achieved using other raw material ratios and reaction conditions in the synthesis of the above-mentioned organic ligand H2L. The molar ratio of ethyl 2-ethoxymethylene-3-oxo-butyrate to p-carboxyphenylhydrazine can be 1-1.1:1-1.1, and the heating temperature can be controlled to reflux, such as a reflux temperature of 90 ℃ to 110 ℃; the molar ratio of ethyl 1-(4-carboxyphenyl)-4-methyl-1H-pyrrole-3-carboxylic acid to NaOH can be 1-1.1:2-2.1; the heating temperature can be controlled to reflux, such as a reflux temperature of 90 ℃ to 110 ℃; and the HCl concentration can be 5-7 M. Example 1

[0055] The method for Zn-CP fluorescent probe materials includes the following steps:

[0056] At room temperature, a colorless, clear solution obtained by dissolving ZnSO4·7H2O (28.8 mg, 0.10 mmol) in 2 mL of H2O was transferred to the bottom of a 10 mL test tube. A mixture of 2 mL H2O and 2 mL DMF was then slowly added dropwise to the surface of this colorless, clear solution. Next, a pale yellow, clear solution was obtained by dissolving H2L (36.9 mg, 0.15 mmol) and KOH (16.8 mg, 0.30 mmol) in a mixture of 1 mL H2O and 2 mL DMF. This pale yellow, clear solution was then slowly added dropwise to the surface of the H2O and DMF mixture, creating a three-layered structure. The test tube was sealed and allowed to stand for two days. After two days, a product appeared in the middle layer of the H2O and DMF mixture. The product was filtered, washed first with deionized water, then with DMF, and finally with ether. After natural drying at room temperature, 16.1 mg of Zn-CP fluorescent probe material was obtained, with a yield of 89%. Example 2

[0057] At room temperature, a colorless, clear solution obtained by dissolving Zn(CH3COO)2·2H2O (43.8 mg, 0.20 mmol) in 2 mL of H2O was transferred to the bottom of a 10 mL test tube. A mixture of 2 mL H2O and 2 mL DMF was then slowly added dropwise to the surface of this colorless, clear solution. Next, a pale yellow, clear solution was obtained by dissolving H2L (49.2 mg, 0.20 mmol) and KOH (16.8 mg, 0.30 mmol) in a mixture of 1 mL H2O and 2 mL DMF. This pale yellow, clear solution was then slowly added dropwise to the surface of the H2O and DMF mixture, creating a three-layered structure. The test tube was sealed and allowed to stand for three days. After three days, a product appeared in the middle layer of the H2O and DMF mixture. The product was filtered, washed first with deionized water, then with DMF, and finally with diethyl ether. After natural drying at room temperature, 14.7 mg of Zn-CP fluorescent probe material was obtained, with a yield of 85%. Example 3

[0058] At room temperature, a colorless, clear solution obtained by dissolving Zn(NO3)2·6H2O (0.10 mmol, 29.7 mg) in 2 mL of H2O was transferred to the bottom of a 10 mL test tube. A mixture of 2 mL H2O and 2 mL DMF was then slowly added dropwise to the surface of this colorless, clear solution. Next, a pale yellow, clear solution was obtained by dissolving H2L (0.10 mmol, 24.6 mg) and KOH (0.25 mmol, 14 mg) in a mixture of 1 mL H2O and 2 mL DMF. This pale yellow, clear solution was then slowly added dropwise to the surface of the H2O and DMF mixture, creating a three-layered structure. The test tube was sealed and allowed to stand for three days. After three days, a product appeared in the middle layer of the H2O and DMF mixture. The product was filtered, washed first with deionized water, then with DMF, and finally with diethyl ether. After natural drying at room temperature, 13.5 mg of Zn-CP fluorescent probe material was obtained, with a yield of 78%. Example 4

[0059] At room temperature, a colorless, clear solution obtained by dissolving ZnCl2 (0.10 mmol, 13.6 mg) in 2 mL of H2O was transferred to the bottom of a 10 mL test tube. A mixture of 2 mL H2O and 2 mL DMF was then slowly added dropwise to the surface of this colorless, clear solution. Next, a pale yellow, clear solution was obtained by dissolving H2L (0.10 mmol, 24.6 mg) and KOH (0.20 mmol, 11.2 mg) in a mixture of 1 mL H2O and 2 mL DMF. This pale yellow, clear solution was then slowly added dropwise to the surface of the H2O and DMF mixture, creating a three-layered structure. The test tube was sealed and allowed to stand for three days. After three days, a product appeared in the middle layer of the H2O and DMF mixture. The product was filtered, washed first with deionized water, then with DMF, and finally with ether. After natural drying at room temperature, 14.3 mg of Zn-CP fluorescent probe material was obtained, with a yield of 83%. Example 5

[0060] The experimental method was the same as in Example 1, except that KOH was replaced with NaOH. A colorless, clear aqueous solution of zinc sulfate heptahydrate was transferred to the bottom of a 10 mL test tube. A mixed solution of H₂O and DMF was then slowly added dropwise to the surface of the aqueous solution. The H₂L ligand and NaOH were then dissolved in the mixed solvent of H₂O and DMF to obtain a pale yellow, clear solution. This pale yellow, clear solution was slowly added dropwise to the surface of the mixed solution of H₂O and DMF, resulting in a three-layered state. The test tube was sealed and allowed to stand for seven days. The product appeared in the middle layer of the mixed solution of H₂O and DMF. The product was filtered, washed first with deionized water, then with DMF, and finally with ether. After natural drying at room temperature, 11.9 mg of Zn-CP fluorescent probe material was obtained, with a yield of 69%.

[0061] Performance testing experiment

[0062] 1. X-ray single-crystal diffraction analysis was performed on the Zn-CP fluorescent probe material prepared in Example 1 of the present invention (the Zn-CP fluorescent probe materials obtained in Examples 1-5 were the same, only the yields differed). For example... Figure 2 As shown, in Zn-CP (L) 2- In the ligand ion, the nitrogen atom on the pyrazole ring does not participate in coordination. The carboxylate group connected to the pyrazole ring forms a bidentate bridge linking Zn1 and Zn1D, creating a [Zn2(-CO2)2] ring. Meanwhile, the carboxylate group connected to the benzene ring coordinates monodentately with Zn1A, forming a one-dimensional chain structure. This Zn-CP fluorescent probe material... Z = 4 monoclinic crystal system P twenty one / c Crystallization in space group, unit cell parameters: a =13.945(3) Å, b =7.6602(15) Å, c = 12.437(3) Å, α = 90°, β = 107.916(7)°, γ = 90°.

[0063] 2. The phase purity of the Zn-CP fluorescent probe material prepared in Example 1 of the present invention was tested by powder diffraction analysis at room temperature. For example... Figure 3 As shown, a large number of Zn-CP products exhibit good phase purity, which is basically consistent with the simulated peaks.

[0064] 3. The Zn-CP fluorescent probe material prepared in Example 1 of the present invention was subjected to thermogravimetric analysis. Figure 4 It can be seen that as the temperature increases, the Zn-CP material loses 9.15% of its weight in the range of 40-166℃, according to the chemical formula of the complex [Zn(L)(H2O)2].n Calculations show that this is equivalent to losing two coordinated H₂O molecules, with a theoretical value of 10.45%. The weight remains essentially unchanged after 166 °C, and the remaining structure continuously decomposes after 310 °C, stabilizing at 706 °C, leaving 24.35% of the weight, equivalent to one ZnO molecule, with a theoretical value of 23.62%. This indicates that the main framework structure of the Zn-CP material has good thermal stability.

[0065] 4. Perform fluorescence emission spectroscopy detection on the one-dimensional Zn-CP fluorescent probe material prepared in Example 1 of the present invention. For example... Figure 5 As shown, the one-dimensional Zn-CP fluorescent probe material prepared in Example 1 has a maximum emission wavelength of 358 nm when the excitation wavelength is 312 nm.

[0066] 5. A fluorescence detection experiment was performed on the Zn-CP fluorescent probe material prepared in Example 1 of the present invention. The specific steps are as follows: At room temperature, 30 mg of Zn-CP powder sample was placed in a ball mill and ground for 5 min, then dispersed in 30 mL of deionized H2O and sonicated for another 30 min to obtain a uniformly dispersed suspension (1 mg / mL). 1 mL of a 5 × 10⁻⁶ concentration was taken... -3 mol / L anion-containing aqueous solution (Cl) - , Br - , F - , I - NO3 - NO2 - CO3 2- SO4 2- , PO4 2- IO3 - SCN - Cr2O7 2- and CrO4 2- The counter cation is K + and Na + Each of the above-mentioned coordination polymer suspensions was added to 2 mL of the solution, sonicated for 30 s, and allowed to stand for 5 min. The fluorescence emission spectrum of the resulting suspension was then measured. Figure 6 It can be seen that the fluorescence intensity of the coordination polymer changes slightly after the addition of most ions, but the change is negligible. However, for Cr2O7... 2- and CrO4 2- The addition of ions quenches the fluorescence of Zn-CP, with quenching efficiencies reaching 98.71% and 98.51%, respectively. Therefore, Zn-CP quenches the fluorescence of Cr2O7. 2- and CrO4 2-The recognition of anions exhibits excellent selectivity. Even in the presence of interfering ions, the Zn-CP fluorescent probe material shows excellent selectivity for Cr2O7. 2- and CrO4 2- Ion recognition is almost unaffected, indicating that this material is effective against Cr2O7 in water. 2- and CrO4 2- The detection of ions all exhibits good anti-interference capabilities.

[0067] 6. A fluorescence detection experiment was performed on the Zn-CP fluorescent probe material prepared in Example 1 of the present invention. The specific steps are as follows: At room temperature, 30 mg of Zn-CP powder sample was placed in a ball mill and ground for 5 min, then dispersed in 30 mL of deionized H2O and sonicated for another 30 min to obtain a uniformly dispersed suspension (1 mg / mL). 1 mL of Cr2O7 at different concentrations was then used... 2- or CrO4 2- An anionic aqueous solution was added to 2 mL of the above-mentioned coordination polymer suspension, and the suspension was sonicated for 30 s and allowed to stand for 5 min. The fluorescence emission spectrum of the resulting suspension was then measured. Figure 7 Zn-CP fluorescent probe material for different concentrations of Cr2O7 2- Fluorescence response spectrum of ions; Figure 8 Zn-CP fluorescent probe material for different concentrations of CrO4 2- Fluorescence response spectrum of ions. (e.g.) Figure 7 As shown in Figure 8, with Cr2O7 2- CrO4 2- With increasing anion concentration, the emission intensity of the Zn-CP fluorescent probe material was observed to decrease continuously. The relative fluorescence intensity ratio ( I 0 / I )-1 and , The linear relationship between 0 and 0.20 mM indicates that it can quantitatively detect Cr2O7 in water at low concentrations. 2- and CrO4 2- Anions K sv (Cr2O7 2- = 3.59 × 10 4 M -1 R 2 =0.9804, K sv (CrO4 2- ) = 1.38 × 10 4 M -1 , R 2= 0.9982, from the formula LOD (limit of detection) = 3 σ / k Calculations show that Zn-CP affects Cr2O7 2- and CrO4 2- The detection limits for ion recognition are 4.51 μM and 11.7 μM, respectively.

[0068] 7. The Zn-CP fluorescent probe material prepared in Example 1 of the present invention is effective against Cr2O7 in water. 2- CrO4 2- Anion fluorescence detection was performed using cyclic testing. The Zn-CP fluorescent probe material was recovered after 5 titration cycles. The solid sample was centrifuged, washed three times with deionized water, dried at 90 °C for 6 h, ground, and collected. Figure 9 and 10 The results showed that the luminescence intensity of the Zn-CP fluorescent probe material hardly decreased, and the quenching efficiency remained almost unchanged after 5 cycles.

[0069] In summary, this invention designs and synthesizes a novel Zn-CP fluorescent probe material for use in Cr2O7 in water. 2- and CrO4 2- The detection of ions is not only fast, but also exhibits strong sensitivity, thermal stability and anti-interference ability. Furthermore, the method is simple to prepare, low in cost, low in pollution and easy to operate.

[0070] The above-described embodiments are merely preferred experimental schemes of the present invention. It should be noted that, for those skilled in the art, the experimental schemes may be described in different ways, and appropriate modifications may be made to the embodiments of the present invention, but all of these modifications are within the protection scope of the present invention.

Claims

1. A Zn-CP fluorescent probe material, characterized in that: The molecular formula of the Zn-CP fluorescent probe is: [Zn(L)(H2O)2] n L 2- It is a divalent anion of (4-(3-methyl-4-carboxy-1H-pyrazole)benzoate; n is an integer greater than or equal to 1; the Zn-CP fluorescent probe belongs to the monoclinic crystal system. Z =4, space group is P twenty one / c Unit cell parameters: a =13.945(3) Å, b = 7.6602(15) Å, c = 12.437(3) Å, α = 90°, β = 107.916(7)°, γ = 90°.

2. A method for preparing the Zn-CP fluorescent probe material as described in claim 1, characterized in that: Includes the following steps: A1. At room temperature, soluble zinc salts are dissolved in H2O and stirred to obtain a colorless and clear solution, which is the zinc salt solution; a mixed solution of H2O and DMF is added dropwise to the surface of the zinc salt solution to form a mixed solution layer of H2O and DMF. A2. Dissolve the H2L ligand and base in a mixed solvent of H2O and DMF and stir to obtain a pale yellow clear solution, which is the ligand solution; The ligand solution was dropped onto the surface of the aforementioned mixed solution layer of H2O and DMF, causing it to exhibit a three-layer state; A3. After sealing and allowing the solution to diffuse statically, and after the product is formed in the mixed solution layer of H2O and DMF, the product is filtered, washed and dried to obtain the Zn-CP fluorescent probe material.

3. The method for preparing the Zn-CP fluorescent probe material according to claim 2, characterized in that: The molar ratio of soluble zinc salt to H2L ligand is 1:1 to 1.

5.

4. The method for preparing the Zn-CP fluorescent probe material according to claim 2, characterized in that: The molar ratio of H2L ligand to base is 1:1.5~2.

5.

5. The method for preparing the Zn-CP fluorescent probe material according to claim 2, characterized in that: In a mixed solution of H2O and DMF, the volume ratio of H2O to DMF is 1~2:

2.

6. The method for preparing the Zn-CP fluorescent probe material according to claim 2, characterized in that: The volume ratio of the zinc salt solution, the mixed solution of H2O and DMF, and the ligand solution is 2:4:

3.

7. The method for preparing the Zn-CP fluorescent probe material according to claim 2, characterized in that: The static diffusion temperature is room temperature, and the static diffusion time is 2 to 7 days.

8. The method for preparing the Zn-CP fluorescent probe material according to claim 2, characterized in that: The H2L ligand is (4-(3-methyl-4-carboxy-1H-pyrazole)benzoic acid, and its preparation method includes the following steps: B1. 2-Ethoxymethylene-3-oxo-butyrate ethyl ester was reacted with p-carboxyphenylhydrazine in isopropanol under reflux until the reaction was complete. The brown solid powder was collected, washed and dried to obtain 1-(4-carboxyphenyl)-4-methyl-1H-pyrazole-3-carboxylic acid ethyl ester. B2. The brown solid powder 1-(4-carboxyphenyl)-4-methyl-1H-pyrazole-3-carboxylic acid ethyl ester obtained in step B1 was refluxed with NaOH until the reaction was complete. Then, hydrochloric acid was added dropwise until the solid precipitated. The solid was filtered, washed, and dried to obtain the H2L ligand 4-(3-methyl-4-carboxy-1H-pyrazole)benzoic acid. The molar ratio of ethyl 2-ethoxymethylene-3-oxo-butyrate to p-carboxyphenylhydrazine is 1–1.1:1–1.1; the molar ratio of ethyl 1-(4-carboxyphenyl)-4-methyl-1H-pyrazole-3-carboxylic acid to NaOH is 1–1.1:2–2.

1.

9. A Zn-CP fluorescent probe material as described in claim 1, used as a fluorescent sensor in the preparation of CrO4 2- and Cr2O7 2- Applications in ion detection reagents.

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