A tetrahydroindazolyl biphenyl type fluorescent probe for detecting hydrazine and a preparation method and application thereof

Abstract

The application discloses a tetrahydroindazole biphenyl type fluorescent probe for detecting hydrazine and a preparation method and application thereof. The fluorescent probe is (3-(4-((2,5,8,11-tetraoxatridecan-13-yloxy)-4'- (6,6-dimethyl-2-(4-nitrophenyl)-4,5,6,7-tetrahydro-2H-5,7-methanobenzimidazole-3-yl)-1,1'-biphenyl-3-yl)-2-(pyridin-4-yl)acrylonitrile (TOPIB-PAN for short). The application uses 4-((2,5,8,11-tetraoxatridecan-13-yloxy)-4'- (6,6-dimethyl-2-(4-nitrophenyl)-4,5,6,7-tetrahydro-2H-5,7-methanobenzimidazole-3-yl)-1,1'-biphenyl-3-formaldehyde (TOPIB-CA for short) as a raw material, and performs an aldol condensation reaction with 4-pyridine acetonitrile to obtain the compound TOPIB-PAN. The compound TOPIB-PAN can specifically react with hydrazine. Under the irradiation of ultraviolet light with a wavelength of 365nm, the solution containing the compound emits green fluorescence. After hydrazine is added into the solution, the fluorescence color of the solution changes from green to colorless. Therefore, the compound can be used as a fluorescent probe for detecting hydrazine, has many advantages such as a low detection limit (7.9*10 ‑ 8 mol / L), a wide pH use range (3-11) and high light stability (>1800min), and has a good application prospect.

Description

TECHNICAL FIELD

[0001] The application 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

[0002] Hydrazine (N2H4) is an important industrial raw material and has a wide application in the fields of medicine, pesticides and textile dyes. However, hydrazine is volatile and toxic, and the wide use of hydrazine inevitably causes serious harm to water, soil, air and organisms, and the absorption of N2H4 directly through the skin and eyes can cause shortness of breath and headache in a short period of time, and can cause damage to the liver, kidneys and nervous system in the long run. N2H4 is also classified as a possible human carcinogen by the United States Environmental Protection Agency (EPA). Therefore, it is of great importance to develop an analysis method for real-time monitoring of the level of hydrazine in the environment for environmental protection and human health.

[0003] At present, the methods for detecting hydrazine mainly include chromatography, chemiluminescence, colorimetry, mass spectrometry and electrochemistry. Compared with these traditional detection methods, fluorescent probes are favored due to their simple synthesis, good selectivity, high sensitivity and other advantages. The tetrahydroindazole biphenyl type fluorescent probe for detecting hydrazine synthesized by using 4-((2,5,8,11-tetraoxatridecan-13-yloxy)-4'-(6,6-dimethyl-2-(4-nitrophenyl)-4,5,6,7-tetrahydro-2H-5,7-bridgemethylinadazole-3-yl)-1,1'-biphenyl-3-formaldehyde (TOPIB-CA for short) as a raw material, 3-(4-((2,5,8,11-tetraoxatridecan-13-yloxy)-4'-(6,6-dimethyl-2-(4-nitrophenyl)-4,5,6,7-tetrahydro-2H-5,7-bridgemethylinadazole-3-yl)-1,1'-biphenyl-3-yl)-2-(pyridin-4-yl)prop-2-enenitrile (TOPIB-PAN for short), is a method for rapid, direct and real-time quantitative detection of hydrazine in food, biological systems and environment, and is of great significance for environmental protection and human health. SUMMARY

[0004] In view of the deficiencies in the prior art, the technical problems to be solved by the present application are 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 application is to provide a preparation method of the fluorescent probe TOPIB-PAN. The present application also aims to solve the technical problem of providing the application of the fluorescent probe TOPIB-PAN.

[0005] To solve the above technical problems, the technical scheme adopted by the present application is as follows:

[0006] A tetrahydroindazolyl biphenyl type fluorescent probe for detecting hydrazine is 3-(4-((2,5,8,11-tetraoxatridecan-13-yloxy)-4'-(6,6-dimethyl-2-(4-nitrophenyl)-4,5,6,7-tetrahydro-2H-5,7-methanobenzazepin-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 tetrahydroindazolyl biphenyl type fluorescent probe for detecting hydrazine, 4-((2,5,8,11-tetraoxatridecan-13-yloxy)-4'-(6,6-dimethyl-2-(4-nitrophenyl)-4,5,6,7-tetrahydro-2H-5,7-methanobenzazepin-3-yl)-1,1'-biphenyl-3-formaldehyde (TOPIB-CA for short) is used as raw material, and the aldol condensation reaction is carried out with 4-pyridine acetonitrile to obtain TOPIB-PAN. Specifically, the following steps are included:

[0009] (1) 0.1 mol of the compound TOPIB-CA, 0.2-0.4 mol of 4-pyridine acetonitrile, 1.5-2 mL of triethylamine and 15-20 mL of anhydrous ethanol are sequentially added into a three-necked flask provided with a stirrer, a reflux condenser and a thermometer, and reflux reaction is carried out for 10-12 h;

[0010] (2) After the reaction solution is subjected to distillation to recover the solvent, TOPIB-PAN crude product is obtained;

[0011] (3) After the TOPIB-PAN crude product is subjected to purification through a silica gel chromatographic column (CH2Cl2:CH3OH=10:1, v / v), TOPIB-PAN in yellow oil form is obtained.

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

[0013] Beneficial effects: Compared with the prior art, the aldol condensation reaction is carried out with TOPIB-CA as raw material and 4-pyridine acetonitrile to obtain the compound TOPIB-PAN. The compound can specifically recognize hydrazine and sensitively detect the content of hydrazine in the solution, and as a fluorescent probe for detecting hydrazine, it has many advantages such as convenient synthesis, good selectivity, high sensitivity and the like, and has a good application prospect. BRIEF DESCRIPTION OF DRAWINGS

[0014] Figure 1The fluorescence spectra of the compound TOPIB-PAN reacting with different concentrations of hydrazine are shown.

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

[0016] The present invention will be further described below with reference to specific embodiments.

[0017] Example 1

[0018] The synthesis reaction of 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 to a three-necked flask equipped with a stirrer. The mixture was refluxed at 78–85 °C for 10–12 h. After distillation to recover the solvent, crude TOPIB-PAN was obtained. This crude product was then purified by silica gel chromatography (CH2Cl2:CH3OH = 10:1, v / v) to obtain a yellow oily substance, 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 formulated into a 1×10⁻⁶ solution. -5 M was prepared in PBS buffer (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 (×10⁻⁶). -5 A solution of M). The fluorescence emission spectra of the compound TOPIB-PAN in the presence of different concentrations of hydrazine were measured using a fluorescence spectrophotometer via fluorescence spectrophotometric titration. For example... Figure 1 As shown in the figure. The results indicate that as the concentration of hydrazine in the solution gradually increases from 0 to 3.6 × 10⁻⁶, -5 M, the fluorescence emission intensity of this compound gradually decreases at 512 nm. This indicates that the compound can be used as a fluorescent probe for the sensitive detection of hydrazine.

[0024] Example 3

[0025] The compound TOPIB-PAN was formulated into a 1×10⁻⁶ solution. -5 M was prepared as a PBS buffer solution (pH = 7.4, 1% EtOH, 10 mM), and different analytes such as metal ions, anions, and biogenic amines were dissolved in the PBS buffer to prepare a solution with a concentration of 2.0 × 10⁻⁶ mM. -4 The solution of M was analyzed. The fluorescence emission spectra of compound TOPIB-PAN in the presence of different analytes, including metal ions, anions, bioactive small molecules, and reactive oxygen species, were measured using a fluorescence spectrophotometer via fluorescence titration. Figure 2 As shown, this compound exhibits a strong fluorescence emission peak at 512 nm, which disappears after reacting with hydrazine. The addition of metal ions (Zn)... 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 - Compared with different analytes such as biogenic amines (hydroxylamine, ethylamine, ammonium carbonate, tetrafluoroborate, benzylamine, and 2-hydroxyethylhydrazine), the fluorescence spectrum of this compound did not change significantly. This indicates that this compound can be used as a fluorescent probe for the selective detection of hydrazine.

Claims

1. A tetrahydroindazole-biphenyl fluorescent probe for detecting hydrazine, characterized in that, Its structural formula is: 。 2. The method for preparing the tetrahydroindazole-biphenyl 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-bridged methyleneindazole-3-yl)-1,1′-biphenyl-3-carboxaldehyde (TOPIB-CA) undergoes a condensation reaction with 4-pyridineacetonitrile to yield 3-(4-((2,5,8,11-tetraoxatridecane-13-oxy)-4′-(6,6-dimethyl-2-(4-nitrophenyl)-4,5,6,7-tetrahydro-2H-5,7-bridged methyleneindazole-3-yl)-1,1′-biphenyl-3-yl)-2-(pyridin-4-yl)acrylonitrile (TOPIB-PAN).

3. The method for preparing a tetrahydroindazole-biphenyl 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 added sequentially to a three-necked flask equipped with a stirrer, a reflux condenser and a thermometer, and the mixture was refluxed for 10-12 h. (2) After the solvent is recovered by distillation, crude TOPIB-PAN product is obtained from the reaction solution; (3) After purification by silica gel column chromatography, the crude TOPIB-PAN product was obtained as a yellow oily product.

4. The application of the tetrahydroindazole biphenyl fluorescent probe of claim 1 in the detection of hydrazine, wherein the application is not for the purpose of disease diagnosis and treatment.

5. The application according to claim 4, characterized in that, The fluorescent probe can react specifically with hydrazine, and under 365nm ultraviolet light irradiation, the fluorescence color of the probe solution changes from green to colorless.

6. The application according to claim 4, characterized in that, The fluorescent probe is used to detect the hydrazine content in the solution, with a detection concentration range of 0–36 μM and a detection limit as low as 7.9 × 10⁻⁶ μM. -8 mol / L.

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