A fluorescent probe, a synthesis method thereof, and an application thereof in detecting hydroxyl group-containing solvents

Abstract

The present invention relates to a fluorescent probe for detecting hydroxyl-containing solvents in organic solutions and a preparation method. The fluorescent probe has the following structural formula: #imgabs0#. The probe is synthesized from 2,7-dibromo-9-fluorenone, 4-triphenylamine borate, tetrakistriphenylphosphine palladium, and potassium carbonate. The fluorescent probe can be used to detect the content of hydroxyl-containing solvents and has the advantages of high sensitivity, low cost, and high detection efficiency. It can also detect and analyze a variety of hydroxyl-containing solvents.

Description

Technical Field

[0001] The present invention relates to a fluorescent probe, in particular to a fluorescent probe for highly sensitive detection of hydroxyl-containing solvents, a synthesis method and application thereof. Background Art

[0002] Hydroxyl-containing solvents, such as water, methanol, and ethanol, are common solvents that play an important role in life and the environment. The detection of hydroxyl-containing solvents has attracted considerable attention from researchers in recent years. It is not only of great significance to daily life and environmental protection, but also plays a vital role in industrial applications such as food, textiles, ceramics, electronics, pharmaceuticals, petroleum, and environmental monitoring. Therefore, the detection of hydroxyl-containing solvents is of great practical significance.

[0003] Currently, the common methods for detecting hydroxyl-containing solvents mainly use some large-scale instrument analysis, such as gas chromatography, liquid chromatography, etc. Although these analysis methods can realize the detection of hydroxyl-containing solvents, they are not popularized due to some disadvantages of instrument analysis.

[0004] Therefore, developing new detection methods for trace hydroxyl solvents has become a hot topic in current research. Fluorescence detection, as a new detection method, has gained popularity due to its high sensitivity, good selectivity, low detection cost, convenient operation, and real-time detection. It is necessary to study new fluorescent probes and fluorescent probe detection methods for detecting hydroxyl solvents in conventional solutions.

[0005] Fluorenone-based fluorescent molecules are widely used and studied due to their high fluorescence quantum yield, stable optical properties, and easily modifiable periphery. Fluorenone molecules contain a rigid surface and exposed oxygen atoms, which can interact with other molecules through hydrogen bonds (C=O···HO), altering fluorescence and thus achieving detection. Summary of the Invention

[0006] In view of the deficiencies of the prior art, the present invention aims to provide a fluorescent probe for highly sensitive detection of hydroxyl-containing solvents and its application.

[0007] In order to achieve the above object, the technical solution adopted by the present invention is:

[0008] A fluorescent probe with the molecular formula C 49 H 34 N2O, the structural formula is as follows:

[0009]

[0010] The preparation method of the fluorescent probe is as follows:

[0011] 2,7-Dibromo-9-fluorenone, 4-triphenylamine borate, tetrakistriphenylphosphine palladium and potassium carbonate were added to a two-necked flask. After vacuuming, argon was passed through three times. Tetrahydrofuran and pure water were added, and the mixture was heated to 85°C and refluxed. After the reaction was completed, the solvent was dried and the crude product was extracted and washed with dichloromethane to obtain the crude product, which was separated and purified by silica gel column chromatography to obtain the probe TPAF.

[0012] The fluorescent probe is used in detecting the content of hydroxyl-containing solvents.

[0013] The detection method of the hydroxyl-containing solvent is:

[0014] (1) Add different concentrations of hydroxyl-containing solvents to the fluorescent probe test solution and stir for 10 seconds to obtain a standard solution for later use;

[0015] (2) Add the test solution to the fluorescent probe test solution, stir for 10 seconds, and set aside;

[0016] (3) measuring the fluorescence intensity of the test solution and the standard solution at 600 nm respectively;

[0017] (4) Establish a linear relationship between the standard solution and the fluorescence intensity and calculate the hydroxyl solvent content in the solution.

[0018] In the application, the volume content of the hydroxyl-containing solvent is 0-1.5%.

[0019] Beneficial effects of the present invention:

[0020] 1. The red fluorescent probe of the present invention can detect conventional hydroxyl-containing solvents, reflecting the sensitivity and accuracy of the probe, and has the advantages of high detection sensitivity, low cost, and high detection efficiency, and can realize the analysis of a variety of hydroxyl-containing solvents.

[0021] 2. This invention utilizes a fluorescent probe, a fluorenone derivative (TPAF). When detecting hydroxyl-containing solvents, water molecules and the fluorescent probe molecule TPAF complex through hydrogen bonding, resulting in intermolecular charge transfer and a decrease in the probe's fluorescence. This allows for simple, rapid, and sensitive detection of hydroxyl-containing solvents.

[0022] 3. Compared with traditional instrument detection methods, the present invention simplifies sample preparation, is easy to operate, and can detect in real time, significantly reducing detection costs. The probe of the present invention can detect hydroxyl-containing solvents such as water in conventional organic solutions, achieving the beneficial effect of rapid and real-time detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 UV-visible absorption and fluorescence spectra of the fluorescent probe TPAF.

[0024] The left side shows the absorbance of TPAF, and the right side shows the fluorescence spectrum under 470 nm excitation.

[0025] Figure 2 Fluorescence spectra of different hydroxyl-containing solvents.

[0026] Wherein, A represents the fluorescence change of TPAF when water is added to tetrahydrofuran solution; B represents the fluorescence change of TPAF when methanol is added to tetrahydrofuran solution; C represents the fluorescence change of TPAF when ethanol is added to tetrahydrofuran solution.

[0027] Figure 3 Linear relationship between water content and fluorescence intensity of different hydroxyl-containing solvents. DETAILED DESCRIPTION

[0028] The specific embodiments of the present invention are further described in detail below with reference to the examples. Unless otherwise specified, the instruments and equipment involved in the examples are all conventional instruments and equipment; the raw materials involved are all commercially available conventional raw materials; and the experimental methods involved are all conventional methods.

[0029] In the examples, the fluorescent probe fluorenone derivative (TPAF) is abbreviated as TPAF. The TPAF solution is prepared using conventional dry pure tetrahydrofuran solvent.

[0030] Example 1. Synthesis of fluorescent probe TPAF

[0031] Weigh 2.0 g of 2,7-dibromo-9-fluorenone (C 13 H6Br2O, molar number 5.92mmol), 3.77g 4-triphenylamine borate (C 18 H 16 BNO2, molar number 13.02mmol), 136.8mg tetrakistriphenylphosphine palladium (C 72 H 60 P4Pd, molar number 0.12mmol) and 8.2g potassium carbonate (K2CO3, molar number 59.2mmol) were added to a 250mL two-necked flask, vacuumed and then purged with argon three times, 120mL tetrahydrofuran and 120mL pure water were added, and the mixture was heated to 85℃ and refluxed for 12 hours. After the reaction, the solvent was dried and the mixture was extracted and washed with dichloromethane. The crude product was separated and purified by silica gel column chromatography using a mobile phase of dichloromethane: petroleum ether in a volume ratio of 1:1 to obtain 3.6g of red solid TPAF (C 49 H 34 N2O, molar number 5.4 mmol, yield 91%).

[0032] The characterization data of TPAF by hydrogen nuclear magnetic resonance spectrum, carbon spectrum and mass spectrum are as follows:

[0033] 1The H NMR chemical shifts are: 1 H NMR (400MHz, CDCl3) δ7.87 (s, 2H), 7.66 (d, J = 6.3Hz, 2H), 7.56-7.44 (m, 6H), 7.27 (t, J = 7.5Hz, 8H), 7.13 (d, J = 7.9Hz, 12H), 7.05 (t, J = 7.2Hz, 4H).

[0034] 13 The C NMR chemical shifts are: 13 C NMR (101MHz, CDCl3) δ193.98,147.82,147.51,142.62,141.50,135.25,133.39,132.57,129.39,127.44,124.69,123.52,123.25,122.42,120.68.

[0035] Mass spectrometry detection: HRMS (ESI) m / z calcd for C 49 H 35 N2O + (M+H) + 667.27439,found667.27417.

[0036] Example 2: UV-Vis Absorption Spectrum and Fluorescence Spectrum Test of Fluorescent Compound TPAF

[0037] Sample preparation: Accurately weigh TPAF and prepare a 1 mmol / L tetrahydrofuran stock solution. Dilute the resulting stock solution to a 10 μmol / L tetrahydrofuran solution for testing.

[0038] UV-visible absorption spectrum test: first test blank tetrahydrofuran to remove background interference, then put 10 μmol / L TPAF tetrahydrofuran solution into the card slot for testing.

[0039] Fluorescence spectrum test: Use the maximum absorption wavelength in the ultraviolet absorption spectrum as the excitation wavelength, set the fluorescence spectrum parameters, and perform the test.

[0040] The spectral results are as follows Figure 1As shown, multiple absorption peaks can be observed in a tetrahydrofuran solution of TPAF. The absorption peaks at approximately 278, 311, and 376 nm are attributed to the π-π* and n-π* transitions in TPAF, while the absorption peak at approximately 470 nm is due to intramolecular charge transfer (ICT) between the triphenylamine moiety (electron-donating) and the fluorenone moiety (electron-withdrawing). In contrast to the absorption spectrum, the fluorescence spectrum of the compound TPAF was measured using the maximum absorption wavelength (470 nm) as the excitation wavelength. TPAF exhibited broad and high fluorescence emission from 450 to 800 nm, with a maximum emission wavelength at 600 nm.

[0041] Example 3: Fluorescence titration experiment of fluorescent probe TPAF to detect hydroxyl-containing solvents

[0042] Accurately weigh TPAF and prepare a 1 mmol / L tetrahydrofuran mother solution. Dilute the resulting mother solution to a 10 μmol / L tetrahydrofuran solution. Then, transfer the 10 μmol / L tetrahydrofuran solution (2.0 mL) into a 1 cm standard quartz cell and titrate with the hydroxyl-containing solvent dropwise. After each addition of the hydroxyl-containing solvent, stir the mixture for a period of time, and then measure the fluorescence emission spectrum at room temperature. The excitation wavelength of the fluorescence emission spectrum is 470 nm, and the emission wavelength range is 490 nm to 850 nm.

[0043] Example 4: Quantitative Detection of Hydroxyl-Containing Solvents

[0044] The total concentration of the fluorescent probe of the present invention is 1.0×10 -5 To different hydroxyl-containing solvent standard solutions of 1 mol / L (according to the method of Example 2), different concentrations of hydroxyl-containing solvents were added (the volume proportions of the hydroxyl-containing solution were 0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 1.1, 1.2, 1.3, 1.4, and 1.5%, respectively), the mixture was allowed to stand and stirred evenly, and the fluorescence emission spectrum was measured with a fixed excitation wavelength of 470 nm.

[0045] Test results such as Figure 2 As shown in the figure, different concentrations of hydroxyl-containing solvents cause different degrees of fluorescence reduction in the fluorescent probe solution (the curve in the figure goes from top to bottom, and the corresponding hydroxyl-containing solvent content increases and the fluorescence gradually decreases). The corresponding fluorescence intensity is strongest at a wavelength of 600nm. Therefore, the fluorescence emission spectrum is measured with a fixed excitation wavelength of 600nm.

[0046] The method for detecting the content of hydroxyl solvent in the solution using a fluorescent probe is:

[0047] (1) To a total concentration of 1.0×10 -5mol / L fluorescent probe solution was added with the solution to be tested or hydroxyl-containing solvents of different concentrations, stirred for 10 seconds and set aside.

[0048] (2) Measure the fluorescence intensity of the test solution and different proportions of hydroxyl-containing solvents at 600 nm.

[0049] (3) Draw a linear relationship diagram between the hydroxyl-containing solvent standard solution and the fluorescence intensity, and calculate the hydroxyl-containing solvent content in the test solution.

[0050] According to the linear relationship between different concentrations of hydroxyl-containing solvents (c) and fluorescence intensity (I), the linear range of the response of hydroxyl-containing solvents in organic solutions is 0-1.5%. Under the condition of a signal-to-noise ratio (S / N) of 3, the detection limits calculated according to 3σ / ρ (where σ is the standard deviation of the blank sample and ρ is the slope of the linear relationship between the fluorescence intensity of the solution and the concentration of the hydroxyl compound) are 0.00005% (water, I = 6.981c + 1.772, R 2 =0.98), 0.00014% (methanol, I = 2.282c + 0.996, R 2 =0.99), 0.00019% (ethanol, I = 1.740c + 1.155, R 2 =0.99), the results are as follows Figure 3 This indicates that the fluorescence change has a good linear relationship with the content of hydroxyl-containing solvents and can be accurately detected.

Claims

1. Application of a fluorescent probe in detecting the content of a hydroxyl-containing solvent, characterized in that: The fluorescent probe molecular formula is C 49 H 34 N2O, the structural formula is as follows: The specific detection methods are: (1) Add different concentrations of hydroxyl-containing solvents to the fluorescent probe test solution and stir for 10 seconds to obtain a standard solution for later use; (2) Add the test solution to the fluorescent probe test solution, stir for 10 seconds, and set aside; (3) measuring the fluorescence intensity of the test solution and the standard solution at 600 nm respectively; (4) Establish a linear relationship between the standard solution and the fluorescence intensity and calculate the hydroxyl solvent content in the solution; The volume content of the hydroxyl-containing solvent is 0-1.5%.

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