Fluorescent organic molecule as well as preparation method and application thereof

Abstract

The invention discloses a fluorescent organic molecule and a preparation method and application thereof.The preparation method of the fluorescent organic molecule comprises the following steps that S1, 4-aminotetraphenyl ethylene is dissolved in acetonitrile, and triethylamine is added; s2, dropwise adding 0.2 mol / L of an acetonitrile solution of a rhodamine B acyl chloride compound into the solution under vigorous stirring, stirring at room temperature, and reacting for 10-20 hours; after the reaction is finished, acetonitrile is removed, and residues are obtained; s3, the residues are dissolved with dichloromethane and washed with a saturated sodium bicarbonate aqueous solution, an obtained organic phase is dried with anhydrous sodium sulfate and filtered, finally, the organic phase is purified through column chromatography, and the faint yellow fluorescent organic molecules are obtained. The prepared fluorescent organic molecule can respectively emit green, blue and orange fluorescence under different induction conditions, shows excellent RGB (Red, Green and Blue) fluorescence characteristics, and has fluorescence characteristics of multiple stimulation responses.

Description

Technical Field

[0001] The invention relates to the technical field of preparation of organic molecules, and in particular to a fluorescent organic molecule and a preparation method and application thereof. Background Art

[0002] In recent years, stimulus-responsive organic fluorescent molecules have attracted much attention. Such molecules can show reversible changes in luminescence properties under external stimuli, such as temperature, pH, light, and chemical reagents. They have unique advantages and broad application prospects in multiple application fields, including display technology, bioimaging, environmental monitoring, disease diagnosis, smart materials, and biomedical engineering. The stimulus-responsive fluorescent molecules that have been reported so far generally have the characteristics of a single response, which makes it difficult to meet the diverse application needs, and the design of multiple stimulus-responsive fluorescent molecules is very challenging.

[0003] At present, the method of achieving full-color display mainly relies on mixing luminescent materials of different colors, but this method has disadvantages such as impure color and narrow color gamut. Realizing RGB luminescence of a single organic molecule is of great significance for the development of high-performance full-color displays and multifunctional sensors. In order to achieve RGB luminescence of a single organic molecule, researchers have proposed a variety of design strategies, such as combining multiple luminescent groups into one molecule or by mixing different forms of fluorescent molecules. However, these methods still have limitations, such as the problem of mixed fluorescence emission.

[0004] Aggregation-induced emission (AIE) refers to the phenomenon that the luminescence of a class of molecules that do not emit light or emit weak light in a solution is significantly enhanced after aggregation. In order to achieve reversible RGB luminescence of a single organic molecule, the AIE group can be combined with a stimulus-responsive fluorescent molecular switch. These molecular switches can undergo structural changes under the action of external stimuli, thereby changing the luminescent color of the molecule. This RGB smart luminescent material has broad application potential in information storage, optical encryption, smart display, and biological detection. Summary of the invention

[0005] One of the purposes of the present invention is to provide a method for preparing fluorescent organic molecules. The technical solution adopted by the present invention is as follows:

[0006] The method for preparing fluorescent organic molecules comprises the following steps:

[0007] S1, dissolving 4-aminotetraphenylethylene in acetonitrile and adding triethylamine;

[0008] S2, adding a 0.2 mol / L acetonitrile solution of rhodamine B acyl chloride compound dropwise to the above solution under vigorous stirring, stirring at room temperature, and the reaction time is 10h-20h; after the reaction is completed, removing the acetonitrile to obtain a residue;

[0009] S3, dissolving the residue with dichloromethane and washing with saturated sodium bicarbonate aqueous solution, drying the obtained organic phase with anhydrous sodium sulfate and filtering, and finally purifying the organic phase by column chromatography to obtain a light yellow fluorescent organic molecule, whose molecular formula is:

[0010]

[0011] The molar ratio of 4-aminotetraphenylethylene to triethylamine is 1.2:9.

[0012] The preparation method of the rhodamine B acyl chloride compound is as follows: dissolving rhodamine B and phosphorus oxychloride in 1,2-dichloroethane, heating and refluxing for 4-8 hours; after the reaction is completed, removing 1,2-dichloroethane to obtain the rhodamine B acyl chloride compound.

[0013] Wherein, the molar ratio of rhodamine to phosphorus oxychloride is 1:6.

[0014] The eluent used in the column chromatography purification includes dichloromethane and ethyl acetate in a volume ratio of 50:1.

[0015] The second object of the present invention is to provide a fluorescent organic molecule. The third object of the present invention is to provide a fluorescent organic molecule for fluorescent material, wherein the fluorescent organic molecule is prepared by the above-mentioned preparation method.

[0016] The steps of using the fluorescent organic molecule for fluorescent material are: dissolving the fluorescent organic molecule in tetrahydrofuran to form a fluorescent mother solution, and then diluting the fluorescent mother solution with a tetrahydrofuran solution containing a color-changing agent, wherein the volume ratio of the color-changing agent to tetrahydrofuran is 0-99:1, and the color-changing agent is water or trifluoroacetic acid.

[0017] The steps of using the fluorescent organic molecule for fluorescent material are as follows: dissolving polymethyl methacrylate, propylene carbonate and the fluorescent organic molecule in dichloromethane, stirring to dissolve, coating on ordinary glass, and obtaining a fluorescent film after the solvent is completely volatilized; wherein the mass ratio of polymethyl methacrylate, propylene carbonate and the fluorescent organic molecule is 80:20:1; and the stirring time is 4 hours.

[0018] Among them, the fluorescent film emits blue fluorescence after being irradiated with ultraviolet light with a wavelength of 365nm at 70°C; the fluorescent film emits green fluorescence after being fumigated with trifluoroacetic acid and irradiated with ultraviolet light with a wavelength of 365nm, and turns into orange-red fluorescence after being heated to 70°C. Then, the fluorescent film emits blue fluorescence after being fumigated with diethylamine and irradiated with ultraviolet light with a wavelength of 365nm.

[0019] Compared with the prior art, the implementation effects of the present invention are as follows: the present invention prepares a fluorescent organic molecule with a novel structure, the preparation method of the fluorescent organic molecule is simple and the cost is low; and the prepared fluorescent organic molecule can emit green, blue and orange-red fluorescence respectively under different induction conditions, showing excellent RGB fluorescence characteristics, and having fluorescence characteristics of multiple stimulus responses. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is the H NMR spectrum of the fluorescent organic molecule in Example 1 of the present invention;

[0021] Figure 2 is the NMR carbon spectrum of the fluorescent organic molecule in Example 1 of the present invention;

[0022] Figure 3 is a high-resolution mass spectrum of the fluorescent organic molecule in Example 1 of the present invention;

[0023] Figure 4 The fluorescence emission spectra of the fluorescent organic molecule in Example 1 of the present invention in a mixed solvent of tetrahydrofuran and water at different ratios under excitation at 365 nm;

[0024] Figure 5 The fluorescence emission spectra of the fluorescent organic molecule in Example 1 of the present invention under the excitation of 365nm in tetrahydrofuran solutions of trifluoroacetic acid at different concentrations;

[0025] Figure 6 The fluorescence excitation and emission spectra of the fluorescent organic molecule tetrahydrofuran solution after ultraviolet irradiation in Example 1 of the present invention;

[0026] Figure 7 This is the fluorescence emission spectrum of the fluorescent film of the fluorescent organic molecules in Example 1 of the present invention under 365nm excitation. DETAILED DESCRIPTION

[0027] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0028] Example 1

[0029] Preparation of fluorescent organic molecules:

[0030] S1, dissolve 2mmol of rhodamine B and 12mmol of phosphorus oxychloride in 10mL of 1,2-dichloroethane and heat to reflux for 4 hours. After the reaction is completed, 1,2-dichloroethane is removed by rotary evaporation to obtain a rhodamine B acyl chloride compound, which is dissolved in 10mL of acetonitrile for standby use, and the concentration of the acetonitrile solution of the rhodamine B acyl chloride compound is 0.2mol / L. The concentration of the acetonitrile solution of the rhodamine B acyl chloride compound of the present embodiment is one of them, and the concentration can be adjusted by the technician in the preparation process.

[0031] S2. Dissolve 2.4 mmol of 4-aminotetraphenylethylene in 20 mL of acetonitrile, add 18 mmol of triethylamine, slowly add the acetonitrile solution of rhodamine B acyl chloride compound dropwise to the above mixture under vigorous stirring, and stir at room temperature for 12 hours. After the reaction is completed, remove the acetonitrile by rotary evaporation, dissolve the residue with dichloromethane, and wash three times with saturated sodium bicarbonate aqueous solution. Dry the organic phase with anhydrous sodium sulfate and filter; the final product is purified by column chromatography (silica, eluent: dichloromethane: ethyl acetate = 50:1) to obtain a light yellow fluorescent organic molecule solid product.

[0032] The preparation reaction steps of the fluorescent organic molecule are:

[0033]

[0034] The prepared fluorescent organic molecule was analyzed by nuclear magnetic resonance to obtain its hydrogen nuclear magnetic resonance spectrum (using a Bruker-400 MHz nuclear magnetic resonance spectrometer from Bruker Company), as shown in FIG. Figure 1 shown. 1 H NMR(400MHz, DMSO-d6)δ7.85(d,J=6.4Hz,1H),7.60-7.47(m,2H),7.11-6.95(m,7H),6.91-6.83(m,2H),6.80-6.72(m,2 H),6.60(d,J=8.2Hz,2H),6.56-6.38(m,6H),6.38-6.20(m,6H),5.07(s,2H),3.35-3.21(m,8H),1.07(t,J=6.9Hz,12H).

[0035] The prepared fluorescent organic molecule was analyzed by nuclear magnetic resonance to obtain its carbon nuclear magnetic resonance spectrum (using a Bruker-400 MHz nuclear magnetic resonance spectrometer from Bruker Company), as shown in FIG. Figure 2 shown. 13C NMR(100MHz,DMSO-d6)δ167.0,153.7,152.7,148.7,147.7,144.4,143.9,142.1,141.6,137.6,135.3,133.8,132.1,131.2,131.1, 131.1,130.6,130.3,128.9,128.8,128.2,127.9,126.6,126.5,125.3,124.3,123.3,113.5,108.5,106.1,97.6,67.0,44.1,12.9.

[0036] The prepared fluorescent organic molecules were analyzed by mass spectrometer (Waters TM Q-TOF Premier) to obtain the result HRMS (ESI) m / z, such as Figure 3 As shown. For C 54 H 50 N4O2[M+H] + The calculated value is 787.4007, the measured value is 787.4006.

[0037] Then the fluorescent organic molecules of this embodiment were subjected to a fluorescence emission test (the test used a HITACHI F-4600 fluorescence spectrophotometer and a Shimadzu UV-3600 ultraviolet-visible (UV-vis) spectrophotometer):

[0038] (1) Fluorescence emission of fluorescent organic molecules in mixed solvents of tetrahydrofuran and water at different volume ratios

[0039] Weigh 7.9 mg of fluorescent organic molecules and dissolve them in 1 mL of tetrahydrofuran. Then, take 25 μL of the solution and dilute it in 10 mL of a mixed solvent of tetrahydrofuran and water in different volume ratios to prepare a concentration of 2.5×10 -5 mol / L fluorescent organic molecule solution, in which the volume ratio of water to tetrahydrofuran is as low as 99:1 and as high as 4:1. The tetrahydrofuran aqueous solution within this concentration range has no special effect on the fluorescence color. The fluorescence emission of the fluorescent organic molecule in a mixed solvent of tetrahydrofuran and water with different volume ratios was tested under 365nm wavelength excitation. The emitted fluorescence is green. The green fluorescence emission spectrum is shown in Figure 4 .

[0040] (2) Fluorescence emission of fluorescent organic molecules in tetrahydrofuran solutions with different concentrations of trifluoroacetic acid

[0041] Weigh 7.9 mg of fluorescent organic molecules and dissolve them in 1 mL of tetrahydrofuran. Then, take 25 uL of the solution and dilute it in 10 mL of tetrahydrofuran containing trifluoroacetic acid (the concentrations of trifluoroacetic acid are: 0.01M, 0.05M, 0.1M, 0.2M, 0.3M, 0.4M, 0.5M, 0.6M, 0.7M, 0.8M, 0.9M, 1.0M). Fluorescent organic molecule tetrahydrofuran solutions containing trifluoroacetic acid of different concentrations can be prepared. The fluorescence emission of fluorescent organic molecules in trifluoroacetic acid tetrahydrofuran of different concentrations was tested under 365 nm wavelength excitation. The emitted fluorescence was orange-red. The orange-red fluorescence emission spectrum is shown in Figure 5 .

[0042] (3) Fluorescence test of tetrahydrofuran solution of fluorescent organic molecules after ultraviolet irradiation

[0043] Weigh 7.9 mg of fluorescent organic molecules and dissolve them in 1 mL of tetrahydrofuran. Then take 25 uL of the solution and dilute it in 10 mL of tetrahydrofuran to prepare a concentration of 2.5×10 -5 mol / L fluorescent organic molecule tetrahydrofuran solution. After irradiation with 365nm ultraviolet light for 5 minutes, the fluorescence emission was tested under 365nm wavelength excitation. The emitted fluorescence was blue. The blue fluorescence emission spectrum is shown in Figure 6 .

[0044] (4) Study on the fluorescence properties of fluorescent films

[0045] 0.8 g of polymethyl methacrylate, 0.2 g of propylene carbonate and 10 mg of fluorescent organic molecules were dissolved in 5 mL of dichloromethane, stirred for 4 hours to dissolve, and coated on ordinary glass. After the solvent evaporated completely, a fluorescent film was obtained.

[0046] The prepared fluorescent film emits blue fluorescence after being irradiated with ultraviolet light of 365nm at 70℃ for 5 minutes ( Figure 7 The fluorescent film emits green fluorescence after being fumigated with trifluoroacetic acid for 1 minute and irradiated with ultraviolet light at a wavelength of 365 nm ( Figure 7 G curve), and turns into orange-red fluorescence after heating to 70℃ ( Figure 7 Then, after the fluorescent film was fumigated with diethylamine for 1 minute, it was irradiated with ultraviolet light of 365nm to emit blue fluorescence.

[0047] Example 2

[0048] The difference from Example 1 is that 2 mmol of rhodamine B and 12 mmol of phosphorus oxychloride are dissolved in 10 mL of 1,2-dichloroethane, and heated under reflux for 6 hours.

[0049] Example 3

[0050] The difference from Example 1 is that 2 mmol of rhodamine B and 12 mmol of phosphorus oxychloride are dissolved in 10 mL of 1,2-dichloroethane, and heated under reflux for 8 hours.

[0051] Example 4

[0052] The difference from Example 1 is that 2.4 mmol of 4-aminotetraphenylethylene is dissolved in 20 mL of acetonitrile, 18 mmol of triethylamine is added, and the acetonitrile solution of rhodamine B acyl chloride is slowly added dropwise to the mixture under vigorous stirring, and the mixture is stirred at room temperature for 10 hours.

[0053] Example 5

[0054] The difference from Example 1 is that 2.4 mmol of 4-aminotetraphenylethylene is dissolved in 20 mL of acetonitrile, 18 mmol of triethylamine is added, and the acetonitrile solution of rhodamine B acyl chloride is slowly added dropwise to the mixture under vigorous stirring, and the mixture is stirred at room temperature for 15 hours.

[0055] Example 6

[0056] The difference from Example 1 is that 2.4 mmol of 4-aminotetraphenylethylene is dissolved in 20 mL of acetonitrile, 18 mmol of triethylamine is added, and the acetonitrile solution of rhodamine B acyl chloride is slowly added dropwise to the mixture under vigorous stirring, and the mixture is stirred at room temperature for 20 h.

[0057] In addition, in the present invention, the heating temperature of the fluorescent film during the fluorescence test may be other than 70°C, such as any temperature between 40°C and 90°C. Therefore, the use of the fluorescent film of the present invention within the temperature range of 40°C to 90°C also falls within the protection scope of the present invention.

[0058] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for preparing a fluorescent organic molecule, characterized in that: The following steps are involved: S1, dissolving 4-aminotetraphenylethylene in acetonitrile and adding triethylamine; S2, adding the acetonitrile solution of rhodamine B acyl chloride compound dropwise to the above solution under vigorous stirring, stirring at room temperature, and the reaction time is 10h-20h; after the reaction is completed, removing the acetonitrile to obtain a residue; S3, dissolving the residue with dichloromethane and washing with saturated sodium bicarbonate aqueous solution, drying the obtained organic phase with anhydrous sodium sulfate and filtering, and finally purifying the organic phase by column chromatography to obtain a light yellow fluorescent organic molecule, whose molecular formula is:

2. The method for preparing fluorescent organic molecules according to claim 1, characterized in that: The molar ratio of the 4-aminotetraphenylethylene to triethylamine is 1.2:

9.

3. The method for preparing fluorescent organic molecules according to claim 1, characterized in that: The preparation method of the rhodamine B acyl chloride compound is as follows: rhodamine B and phosphorus oxychloride are dissolved in 1,2-dichloroethane, and heated under reflux for 4-8 hours; after the reaction is completed, 1,2-dichloroethane is removed to obtain the rhodamine B acyl chloride compound.

4. The method for preparing fluorescent organic molecules according to claim 3, characterized in that: The molar ratio of the rhodamine to phosphorus oxychloride is 1:

6.

5. A fluorescent organic molecule, characterized in that: Prepared by the preparation method according to any one of claims 1 to 5.

6. The use of the fluorescent organic molecule according to claim 5, characterized in that: For fluorescent materials.

7. The use of the fluorescent organic molecule according to claim 5, characterized in that: For fluorescent materials; the steps are: dissolving fluorescent organic molecules in tetrahydrofuran to form a fluorescent mother solution, and then diluting the fluorescent mother solution with a tetrahydrofuran solution containing a color-changing agent, wherein the volume ratio of the color-changing agent to tetrahydrofuran is 0-99:1, and the color-changing agent is water or trifluoroacetic acid.

8. The use of the fluorescent organic molecule according to claim 5, characterized in that: Used for fluorescent materials; the steps are: dissolving polymethyl methacrylate, propylene carbonate and fluorescent organic molecules in dichloromethane, stirring to dissolve, coating on ordinary glass, and removing the solvent to obtain a fluorescent film.

9. The use of fluorescent organic molecules according to claim 8, characterized in that: The mass ratio of polymethyl methacrylate, propylene carbonate and fluorescent organic molecules is 80:20:1; the stirring time is 4h.

10. The use of fluorescent organic molecules according to claim 8, characterized in that: The fluorescent film emits blue fluorescence after being irradiated with ultraviolet light of a wavelength of 365nm at 70°C; the fluorescent film emits green fluorescence after being fumigated with trifluoroacetic acid and irradiated with ultraviolet light of a wavelength of 365nm, which changes into orange-red fluorescence after being heated to 70°C, and then the fluorescent film emits blue fluorescence after being fumigated with diethylamine and irradiated with ultraviolet light of a wavelength of 365nm.

Images