Tetrahydroindazole biphenyl fluorescent probe for detecting hydrazine as well as preparation method and application of tetrahydroindazole biphenyl fluorescent probe

Abstract

The invention discloses a tetrahydroindazole biphenyl fluorescent probe for detecting hydrazine as well as a preparation method and application of the tetrahydroindazole biphenyl fluorescent probe. The fluorescent probe is (3-(4-((2, 5, 8, 11-tetraoxa tridecane-13-oxyl)-4 '-(6, 6-dimethyl-2-(4-nitrophenyl)-4, 5, 6, 7-tetrahydro-2H-5, 7-methylene indazole-3-yl)-1, 1'-biphenyl-3-yl)-2-(pyridine-4-yl) acrylonitrile (TOPIB-PAN for short), and the fluorescent probe has the structural formula shown in the specification. According to the preparation method, 4-((2, 5, 8, 11-tetraoxa tridecane-13-oxyl)-4 '-(6, 6-dimethyl-2-(4-nitrophenyl)-4, 5, 6, 7-tetrahydro-2H-5, 7-methylene indazole-3-yl)-1, 1'-biphenyl-3-formaldehyde (for short, TOPIB-CA) is used as a raw material, the raw material and 4-pyridine acetonitrile are subjected to aldol condensation reaction, and the compound TOPIB-PAN is obtained. The compound TOPIB-PAN can be subjected to a specific reaction with hydrazine, a solution containing the compound emits green fluorescence under the irradiation of ultraviolet light with the wavelength of 365 nm, and the fluorescence color of the solution is changed from green to colorless after hydrazine is added into the solution, so that the compound can be used as a fluorescent probe for detecting hydrazine and has the characteristics of low detection limit (7.9 * 10 <-8 > mol / L), wide pH application range (3-11) and high light stability (gt; 1800 min), and the like, and has a good application prospect.

Description

Technical Field

[0001] The invention belongs to the technical field of fine organic synthesis and relates to a tetrahydroindazole biphenyl type fluorescent probe for detecting hydrazine and a preparation method and application thereof. Background Art

[0002] Hydrazine (N2H4) is an important industrial raw material with a wide range of applications in medicine, pesticides and textile dyes. However, hydrazine is volatile and highly toxic. The widespread use of hydrazine inevitably causes serious harm to water, soil, air and organisms. The absorption of N2H4 directly through the skin and eyes can cause shortness of breath and headaches in the short term, and can cause damage to the liver, kidneys and nervous system in the long term. N2H4 is also classified as a possible human carcinogen by the U.S. Environmental Protection Agency (EPA). Therefore, the development of an analytical method for real-time monitoring of hydrazine levels in the environment is crucial for environmental protection and human health.

[0003] At present, the main methods for detecting hydrazine include chromatography, chemiluminescence, colorimetry, mass spectrometry, electrochemical method, etc. Compared with these traditional detection methods, fluorescent probes are favored due to their advantages such as simple synthesis, good selectivity and high sensitivity. A tetrahydroindazole biphenyl type fluorescent probe 3-(4-((2,5,8,11-tetraoxatridecan-13-oxy)-4′-(6,6-dimethyl-2-(4-nitrophenyl)-4,5,6,7-tetrahydro-2H-5,7-bridged methylindazole-3-yl)-1,1′-biphenyl-3-carboxaldehyde (abbreviated as TOPIB-CA) was synthesized as a raw material for detecting hydrazine. TOPIB-PAN is a rapid, direct and real-time quantitative detection method for hydrazine in food, biological systems and the environment, which is of great significance for environmental protection and human health. Summary of the invention

[0004] In view of the deficiencies in the prior art, the technical problem to be solved by the present invention is to provide a tetrahydroindazole biphenyl type fluorescent probe for detecting hydrazine, which can meet the use requirements. Another technical problem to be solved by the present invention is to provide a method for preparing the fluorescent probe TOPIB-PAN. Another technical problem to be solved by the present invention is to provide an application of the fluorescent probe TOPIB-PAN.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0006] A tetrahydroindazole biphenyl type fluorescent probe for detecting hydrazine is 3-(4-((2,5,8,11-tetraoxatridecan-13-oxy)-4′-(6,6-dimethyl-2-(4-nitrophenyl)-4,5,6,7-tetrahydro-2H-5,7-oxodimethanoindazole-3-yl)-1,1′-biphenyl-3-yl)-2-(pyridin-4-yl)acrylonitrile (TOPIB-PAN for short), and its structural formula is:

[0007]

[0008] The preparation method of the tetrahydroindazole biphenyl type fluorescent probe for detecting hydrazine, 4-((2,5,8,11-tetraoxatridecane-13-oxy)4′-(6,6-dimethyl-2-(4-nitrophenyl)-4,5,6,7-tetrahydro-2H-5,7-bridged methyl indazole-3-yl)-1,1′-biphenyl-3-carboxaldehyde (abbreviated as TOPIB-CA) is used as a raw material, and an aldol condensation reaction is carried out with 4-pyridine acetonitrile to obtain TOPIB-PAN. Specifically, the method comprises the following steps:

[0009] (1) 0.1 mol of compound TOPIB-CA, 0.2-0.4 mol of 4-pyridineacetonitrile, 1.5-2 mL of triethylamine, and 15-20 mL of anhydrous ethanol were sequentially added into a three-necked flask equipped with a stirrer, a reflux condenser, and a thermometer, and refluxed for 10-12 hours;

[0010] (2) The reaction solution is distilled to recover the solvent, thereby obtaining a crude TOPIB-PAN product;

[0011] (3) The crude TOPIB-PAN product was purified by silica gel chromatography (CH2Cl2:CH3OH=10:1, v / v) to obtain yellow oily TOPIB-PAN.

[0012] The compound TOPIB-PAN can selectively identify hydrazine. Under 365nm ultraviolet light, the solution fluorescence color changes from green to colorless. The compound can sensitively detect the hydrazine content in the solution, with a detection limit as low as 7.9×10 -8 mol / L.

[0013] Beneficial effects: Compared with the prior art, the present invention uses TOPIB-CA as a raw material and undergoes an aldol condensation reaction with 4-pyridineacetonitrile to obtain a compound TOPIB-PAN. The compound can specifically identify hydrazine and can sensitively detect the content of hydrazine in a solution. As a fluorescent probe for detecting hydrazine, it has many advantages such as convenient synthesis, good selectivity, high sensitivity, etc., and has good application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1This is the fluorescence spectrum of the compound TOPIB-PAN acting on hydrazine at different concentrations;

[0015] Figure 2 It is the fluorescence spectrum of the compound TOPIB-PAN interacting with different analytes such as metal ions, anions, and biogenic amines. DETAILED DESCRIPTION

[0016] The present invention will be further described below in conjunction with specific embodiments.

[0017] Example 1

[0018] The synthesis reaction of the compound TOPIB-PAN is as follows:

[0019]

[0020] The specific steps are as follows:

[0021] 0.1 mol TOPIB-CA, 1.5-2 mL 4-pyridineacetonitrile and 15-20 mL anhydrous ethanol were sequentially added into a three-necked flask equipped with a stirrer, and the mixture was refluxed at 78-85°C for 10-12 hours. The reaction solution was distilled to recover the solvent to obtain a crude TOPIB-PAN product, which was then purified by silica gel chromatography (CH2Cl2:CH3OH=10:1, v / v) to obtain a yellow oily TOPIB-PAN. 1 H NMR (600MHz, CDCl3) δ: 8.72 (d, J = 5.5Hz, 2H), 8.52 (d, J = 2.2Hz, 1H), 8.35 (d, J = 9.4Hz, 3H), 8.02 (d, J = 8.2Hz, 2H), 7.76 (dd, J=8.6, 2.3Hz, 1H), 7.73-7.65 (m, 7H), 7.09 (d, J=8.7Hz, 1H), 4.30 (t, J= 4.8Hz, 2H), 3.93 (t, J= 4.8Hz, 2H), 3.74 (dd, J= 5.9, 3 .6Hz, 2H), 3.69-3.58 (m, 10H), 3.52 (dd, J=5.8, 3.5Hz, 2H), 3.19 (t, J=5.2Hz, 1H), 3.13 (dd, J=15.6, 3.0Hz, 1H), 3.04 (dd, J= 15.5, 2.7Hz, 1H), 2.80 (dt, J=9.5, 5.8Hz, 1H), 2.47 (tt, J=5.7, 2.9Hz, 1H), 1.56 (d, J=9.6Hz, 1H), 1.49 (s, 3H), 0.85 (s, 3H); 13C NMR (150MHz, CDCl3) δ: 157.17, 150.36, 150.17, 149.60, 145.62, 144.59, 142.32 ,140.58,139.19,133.87,132.46,131.40,127.17,127.01,126.97,124.95,123 .04, 120.20, 117.28, 113.59, 112.95, 109.37, 71.91, 70.89, 70.67, 70.63, 70.59, 70.51, 69.56, 68.60, 59.02, 41.61, 41.40, 32.19, 29.70, 26.86, 26.27, 21.65.

[0022] Example 2

[0023] The compound TOPIB-PAN was prepared into 1×10 -5 M PBS buffer solution (pH = 7.4, 1% DMSO, 10 mM), and hydrazine was dissolved in PBS buffer to prepare concentrations of 0, 0.2, 0.4, 0.6, 0.8, 1.0, 1.2, 1.4, 1.6, 1.8, 2.0, 2.2, 2.4, 2.6, 2.8, 3.0, 3.2, 3.4, 3.6 (×10 -5 The fluorescence emission spectrum of the compound TOPIB-PAN in the presence of different concentrations of hydrazine was measured on a fluorescence spectrophotometer using a fluorescence spectrum titration method, such as Figure 1 The results show that as the hydrazine concentration in the solution gradually increases from 0 to 3.6×10 -5 M, the fluorescence emission intensity of the compound at 512 nm gradually decreased. This shows that the compound can be used as a fluorescent probe for sensitive detection of hydrazine.

[0024] Example 3

[0025] The compound TOPIB-PAN was prepared into 1×10 -5 M PBS buffer solution (pH = 7.4, 1% EtOH, 10 mM), and different analytes such as metal ions, anions, and biogenic amines were dissolved in PBS buffer to a concentration of 2.0 × 10 -4 The fluorescence emission spectra of the compound TOPIB-PAN in the presence of different analytes such as metal ions, anions, bioactive small molecules and reactive oxygen species were measured using a fluorescence spectrophotometer using a fluorescence spectrophotometer. Figure 2 As shown. The compound has a strong fluorescence emission peak at 512nm, and the fluorescence emission peak disappears after reacting with hydrazine. 2+ , Al 3+, Fe 2+ , Cd 2+ , Cu 2+ , Ni 2+ ,Ag 2+ , Hg 2+ , Fe 3+ , Ba 2+ ,Cr 2+ ), anion (H2PO4 - ,CO3 2- , HCO3 - ,NO2 - ), biogenic amines (hydroxylamine, ethylamine, ammonium carbonate, tetrafluoroborate, benzylamine, 2-hydroxyethylhydrazine) and other analytes, the fluorescence spectrum of the compound did not change significantly. This shows that the compound can be used as a fluorescent probe for selective detection of hydrazine.

Claims

1. A tetrahydroindazole biphenyl fluorescent probe for detecting hydrazine and its preparation method and application, characterized in that: Its structural formula is:

2. The method for preparing the tetrahydroindazole biphenyl type fluorescent probe for detecting hydrazine according to claim 1, characterized in that: 4-((2,5,8,11-tetraoxatridecane-13-oxy)-4′-(6,6-dimethyl-2-(4-nitrophenyl)-4,5,6,7-tetrahydro-2H-5,7-methanoindazol-3-yl)-1,1′-biphenyl-3-carboxaldehyde (abbreviated as TOPIB-CA) is subjected to condensation reaction with 4-pyridineacetonitrile to obtain 3-(4-((2,5,8,11-tetraoxatridecane-13-oxy)-4′-(6,6-dimethyl-2-(4-nitrophenyl)-4,5,6,7-tetrahydro-2H-5,7-methanoindazol-3-yl)-1,1′-biphenyl-3-yl)-2-(pyridin-4-yl)acrylonitrile (abbreviated as TOPIB-PAN).

3. The method for preparing a tetrahydroindazole biphenyl type fluorescent probe for detecting hydrazine according to claim 2, characterized in that: The specific preparation method of the fluorescent probe TOPIB-PAN includes: (1) 0.1 mol of compound TOPIB-CA, 0.2-0.4 mol of 4-pyridineacetonitrile, 1.5-2 mL of triethylamine, and 15-20 mL of anhydrous ethanol were sequentially added into a three-necked flask equipped with a stirrer, a reflux condenser, and a thermometer, and refluxed for 10-12 hours; (2) The reaction solution is distilled to recover the solvent, thereby obtaining a crude TOPIB-PAN product; (3) The crude TOPIB-PAN product was purified by silica gel column chromatography (CH2Cl2:CH3OH=10:1, v / v) to obtain yellow oily TOPIB-PAN.

4. Use of the tetrahydroindazole biphenyl fluorescent probe TOPIB-PAN according to claim 1 in detecting hydrazine.

5. The use according to claim 4, characterized in that: The fluorescent probe TOPIB-PAN can react specifically with hydrazine. Under irradiation with 365nm ultraviolet light, the fluorescence color of the probe solution changes from green to colorless.

6. The use according to claim 4, characterized in that: The fluorescent probe TOPIB-PAN was used to detect the content of hydrazine in the solution. The detection concentration range was 0-36 μM, and the detection limit was as low as 7.9×10 -8 mol / L.

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