An anthracene-based fluorescent polymer, its preparation method and application

Abstract

The present invention relates to the technical field of fluorescent polymers, and specifically relates to an anthracene-based fluorescent polymer, a preparation method thereof, and an application thereof. Pure Ar-PIs do not have fluorescence and cannot be directly applied to light-emitting devices. In view of the above problems, the present invention provides an anthracene-based fluorescent polymer. An anthracene-based luminescent group is introduced into the molecular structure of the polyimide. The obtained anthracene-based fluorescent polymer has good solubility in a variety of organic solvents and can be prepared into a fluorescent probe or a fluorescent polymer film with recognition and detection functions, having good application prospects.

Description

Technical Field

[0001] The present invention relates to the technical field of fluorescent polymers, and specifically relates to an anthracene-based fluorescent polymer, a preparation method thereof, and an application thereof. Background Art

[0002] In recent years, the applications of luminescent materials in chemical sensing, fluorescent probes, optical imaging, anti-counterfeiting labels, drug traceability, etc. have received increasing attention. Rare earth materials, semiconductor quantum dots, and organic polymer fluorescent materials have been widely studied. Rare earth fluorescent materials and semiconductor quantum dots are favored for their narrow emission bands, rich colors, long fluorescence lifetimes, etc. However, both of the above two luminescent materials have problems such as poor solubility, biotoxicity, and mechanical flexibility. In contrast, organic polymer fluorescent materials have attracted much attention due to their stable physical, chemical, and luminescent properties, and have many advantages such as high molecular weight, good solubility, and fast response. Therefore, photoconductors, biosensors, and fluorescent probes based on organic polymer fluorescent materials have also been designed, synthesized, and modified into various types.

[0003] As a kind of high-performance engineering polymer, fully aromatic polyimide (Ar-PIs) has excellent thermal stability, chemical resistance, radiation resistance, mechanical strength, and flexibility. At the same time, it has a high glass transition temperature and can better adapt to the use in harsh environments. However, pure Ar-PIs has poor film-forming ability and does not have fluorescence, which greatly limits its wide application in light-emitting devices. Summary of the Invention

[0004] The problems existing in the prior art are that pure Ar-PIs does not have fluorescence and is difficult to form a film, and cannot be directly applied to light-emitting devices. In view of the above problems, the present invention provides an anthracene-based fluorescent polymer, which has the following structural formula:

[0005]

[0006] In the above structural formula, m = 5 - 20, n = 80 - 95.

[0007] Preferably, the preparation method of the anthracene-based fluorescent polymer includes the following steps:

[0008] (1) 9,10-dibromoanthracene and 3-nitrobenzeneboric acid are added to a reactor, and solvent I, reducing agent I, and catalyst I are added under nitrogen protection. The temperature of the reaction system is raised to 80°C, and then a phase transfer agent and sodium carbonate aqueous solution are added. The temperature of the reaction system is then raised to 105°C, and the reaction is stirred for 4-8 hours. After the reaction is completed, the reaction solution is subjected to vacuum distillation to remove the solvent and water in the reaction system. The reaction product is purified by silica gel chromatography and then vacuum dried at 120°C for 6 hours to obtain yellow compound I. The chemical structure of the yellow compound is as follows:

[0009]

[0010] (2) Yellow compound I is placed in a reactor. Under nitrogen protection, solvent II, reducing agent II, and catalyst II are added to the reaction system. The temperature of the reaction system is then raised to 90-100°C and stirred for 5-7 hours. When the reaction system turns clear and translucent black, the reaction is completed. After the catalyst II and reducing agent II are removed by hot filtration, the filtrate is allowed to stand until the solid matter in the filtrate is completely precipitated, and the solid product is collected by filtration. After vacuum drying at 60°C for 12 hours, yellow compound II is obtained. The reaction process diagram is shown in the attached specification. Figure 1 The chemical structural formula of the yellow compound II is as follows:

[0011]

[0012] (3) Under nitrogen protection, yellow compound II, 2,6-diaminotoluene, 3,3,4,4'-benzophenone tetracarboxylic dianhydride, solvent III and catalyst III are added to the reactor, the temperature of the reaction system is raised to 170-200 ° C, and the reaction is stirred for 3-4 hours. After the reaction is completed, the reaction solution is poured into anhydrous ethanol and naturally precipitated. When the solid product in the reaction solution no longer precipitates, the reaction solution is filtered to remove solvent III. The obtained solid product is washed and dried to obtain anthracene-based fluorescent polymer. The reaction process diagram is shown in the attached specification. Figure 2 shown.

[0013] Preferably, in step (1), the molar ratio of 9,10-dibromoanthracene to 3-nitrobenzeneboric acid is 1:2.

[0014] Preferably, in step (1), the reducing agent I is sodium carbonate, and the amount added is twice the mass of 9,10-dibromoanthracene;

[0015] In step (1), catalyst I is tetrakis(triphenylphosphine)palladium, and the amount added is 0.1-0.3 times the mass of 9,10-dibromoanthracene;

[0016] In step (1), solvent I is toluene, and the amount added is 2-5 times the mass of 9,10-dibromoanthracene;

[0017] In step (1), the phase transfer agent is ethylene glycol dimethyl ether, and the addition amount is 2 - 5 times the mass of 9,10-dibromoanthracene;

[0018] In step (1), the mass concentration of the aqueous sodium carbonate solution is 10%, and the addition amount is 2 - 5 times the mass of 9,10-dibromoanthracene.

[0019] Preferably, the solvent II in step (2) is ethylene glycol methyl ether, and the addition amount is 5 - 10 times the mass of the yellow compound I;

[0020] The reducing agent II in step (2) is hydrazine hydrate, and the addition amount is 0.1 times the mass of the yellow compound I;

[0021] The catalyst II in step (2) is palladium-carbon catalyst, and the addition amount is 0.1 - 0.3 times the mass of the yellow compound I.

[0022] Preferably, the solvent III in step (3) is m-cresol, and the addition amount is 5 - 10 times the mass of the yellow compound II;

[0023] The catalyst III in step (3) is isoquinoline, and the mass concentration of the isoquinoline in m-cresol is 1 - 4%;

[0024] In step (3), the total molar amount of 2,6-diaminotoluene and 3,3,4,4'-benzophenone tetracarboxylic dianhydride is equal to the molar amount of the yellow compound II.

[0025] A fluorescent probe, which uses the anthracene-based fluorescent polymer obtained by the present invention as a fluorophore, and the preparation method includes the following steps:

[0026] Mix the anthracene-based fluorescent polymer with an organic solvent evenly so that the anthracene-based fluorescent polymer is completely dissolved in the organic solvent, and a fluorescent probe solution is obtained. The mass concentration of the fluorescent probe solution is 2 - 8%.

[0027] Preferably, the organic solvent includes at least one of N,N-dimethylacetamide, N,N-dimethylformamide, chloroform, tetrahydrofuran, N-methylpyrrolidone, and dimethyl sulfoxide.

[0028] A fluorescent sensing film, which uses the anthracene-based fluorescent polymer obtained by the present invention as a fluorescent substance, and the preparation method includes the following steps:

[0029] Mix the anthracene-based fluorescent polymer with an organic solvent so that the anthracene-based fluorescent polymer is completely dissolved in the organic solvent to obtain a fluorescent coating. The mass concentration of the anthracene-based fluorescent polymer in the organic solvent is 10 - 15%. Then coat the fluorescent coating on the surface of a substrate, and then place it in a vacuum drying oven for drying to obtain the fluorescent sensing film.

[0030] Preferably, the vacuum drying temperature is 100 °C and the drying time is 6 - 8 h.

[0031] The present invention has the following beneficial effects:

[0032] (1) The anthracene-based fluorescent polymer obtained in the present invention has good fluorescence and can be made into light-emitting devices such as fluorescent probes or fluorescent sensing films, showing good application prospects;

[0033] (2) The anthracene-based fluorescent polymer obtained in the present invention has good solubility in a variety of organic solvents and can be dissolved in organic solvents such as N,N-dimethylacetamide, N,N-dimethylacetamide, N-methylpyrrolidone, etc. at room temperature;

[0034] (3) Traditional polyimides have poor solubility in organic solvents and it is impossible to obtain a polymer solution with good solubility in a variety of solvents. Their film-forming method requires two steps. The solubility of polyamic acid is relatively good. Usually, polyamic acid is first dissolved to prepare a film, and then imidization is carried out by heating or chemical methods to obtain a polyimide film. However, in the present invention, by introducing anthracene groups into the polyimide structure, the steric hindrance between polyimide molecular chains is increased, greatly improving the solubility of polyimide in organic solvents. The anthracene-based fluorescent polymer obtained in the present invention can be directly dissolved in organic solvents for film formation, and not only has good solubility in a variety of organic solvents, but also has good fluorescence stability. Description of the Drawings

[0035] Figure 1 : Schematic diagram of the reaction process for the preparation of yellow compound II.

[0036] Figure 2 : Schematic diagram of the reaction process for the preparation of anthracene-based fluorescent polymer.

[0037] Figure 3 : 1H NMR spectra of yellow compound I and yellow compound II obtained in Example 1.

[0038] Figure 4 : 1H NMR spectrum of the anthracene-based fluorescent polymer obtained in Example 1.

[0039] Figure 5 : 1H NMR spectrum of the anthracene-based fluorescent polymer obtained in Example 2.

[0040] Figure 6 : 1H NMR spectrum of the anthracene-based fluorescent polymer obtained in Example 3.

[0041] Figure 7 : 1H NMR spectrum of the anthracene-based fluorescent polymer obtained in Example 4.

[0042] Figure 8: Fluorescence spectrum of anthracene-based polymer solution probe.

[0043] Figure 9 : Fluorescence spectrum of anthracene-based polymer sensing film. Detailed implementation mode

[0044] The present invention will be described in detail below with reference to embodiments. However, it should be understood that the following embodiments are only illustrative examples of the implementation modes of the present invention, rather than limiting the scope of the present invention.

[0045] Example 1

[0046] (1) The synthesis steps of yellow compound I are as follows:

[0047] Under a nitrogen atmosphere, 60 mmol of 9,10-dibromoanthracene, 128 mmol of 3-nitrobenzeneboronic acid, and 2.4 mmol of the catalyst tetrakis(triphenylphosphine)palladium were mixed evenly in 250 ml of toluene. Then, while continuously stirring, the temperature of the reaction system was raised to 80 °C. Then, 100 mL of the co-solvent ethylene glycol dimethyl ether was added to the reaction system. Then, 250 mL of sodium carbonate solution (120 mmol) was added to the reaction system. Then, the reaction system was stirred and heated to 105 °C. The reaction was carried out until a solid precipitated in the reaction system. After the solid had precipitated for 4 h, toluene and water in the reaction solution were removed by reduced pressure distillation. Then, the reaction solution was filtered. The obtained solid product was dried at 60 °C for 6 h. Then, it was purified by a silica gel chromatographic column to obtain a yellow solid. The obtained yellow solid was vacuum dried at 120 °C for 6 h to obtain yellow compound I. The eluent used was dichloromethane. The 1H NMR spectrum of the obtained yellow compound I is as shown in the attached Figure 3 shown;

[0048] (2) The preparation steps of yellow compound II are as follows:

[0049] 20 mmol of yellow compound I and 0.85 g of palladium carbon catalyst (Pd / C, 5%) were stirred and mixed evenly in 150 mL of ethylene glycol methyl ether. Then, the reaction system was stirred and heated to 95 °C. Then, within 1 h, 15 ml of 50% hydrazine hydrate aqueous solution was added dropwise to the reaction system. Then, the reaction was stirred for 5 - 7 h. The reaction was carried out until the reaction system became a homogeneous, transparent black solution. Then, it was filtered while it was hot. The obtained filtrate was allowed to stand. After no more yellow solid precipitated from the filtrate, the solid product was obtained by filtration. The obtained solid product was dried at 60 °C for 12 h to obtain yellow compound II. The 1H NMR spectrum of the obtained yellow compound II is as shown in the attached Figure 3 shown;

[0050] (3) The preparation method of the anthracene-based fluorescent polymer is as follows:

[0051] In a three-necked flask, 0.5 mmol of yellow compound II, 9.5 mmol of methylphenylenediamine, and 10 mmol of benzophenone tetracarboxylic dianhydride (CAS No.: 2421-28-5) were added. Then, 20 mL of m-cresol was added as a solvent. After that, the temperature of the reaction system was raised to 190 °C. Then, 0.4671 g of isoquinoline was added as a catalyst to the reaction system, and the mixture was stirred for 4 h. After the reaction was completed, the reaction solution was poured into 250 mL of absolute ethanol. After the solid product in the solution had completely settled naturally, the solution was filtered and washed, and then dried in a forced-air oven at 60 °C for 12 h and then dried under vacuum at 200 °C for 2 h to obtain an anthracene-based fluorescent polymer. In the molecular structural formula of the anthracene-based fluorescent polymer, m = 5 and n = 95. The nuclear magnetic resonance hydrogen spectrum of the obtained anthracene-based fluorescent polymer is as shown in the appendix of the specification Figure 4 as shown.

[0052] Example 2 was the same as Example 1, except that the preparation method of the anthracene-based fluorescent polymer in Example 2 was as follows:

[0053] In a three-necked flask, 1 mmol of yellow compound II (i.e., anthracene diamine monomer), 9 mmol of methylphenylenediamine, and 10 mmol of benzophenone tetracarboxylic dianhydride (CAS No.: 2421-28-5) were added. Then, 20 mL of m-cresol was added as a solvent. After that, the temperature of the reaction system was raised to 190 °C. Then, 0.4671 g of isoquinoline was added as a catalyst to the reaction system, and the mixture was stirred for 4 h. After the reaction was completed, the reaction solution was poured into 250 mL of absolute ethanol. After the solid product in the solution had completely settled naturally, the solution was filtered and washed, and then dried in a forced-air oven at 60 °C for 12 h and then dried under vacuum at 200 °C for 2 h to obtain an anthracene-based fluorescent polymer. In the molecular structural formula of the anthracene-based fluorescent polymer, m = 10 and n = 90. The nuclear magnetic resonance hydrogen spectrum of the obtained anthracene-based fluorescent polymer is as shown in the appendix of the specification Figure 5 as shown.

[0054] Example 3 was the same as Example 1, except that the preparation method of the anthracene-based fluorescent polymer in Example 2 was as follows:

[0055] In a three-necked flask, 1.5 mmol of yellow compound II (i.e., anthracene diamine monomer), 8.5 mmol of methylphenylenediamine and 10 mmol of benzophenone tetracarboxylic dianhydride (CAS No.: 2421-28-5) were added. Then, 20 mL of m-cresol was added as a solvent. After that, the temperature of the reaction system was raised to 190 °C. Then, 0.4671 g of isoquinoline was added as a catalyst to the reaction system, and the mixture was stirred for 4 h. After the reaction was completed, the reaction solution was poured into 250 mL of absolute ethanol. After the solid product in the solution settled completely naturally, the solution was filtered and washed, and then dried in a blast dryer at 60 °C for 12 h and then dried in vacuo at 200 °C for 2 h to obtain the anthracene-based fluorescent polymer. In the molecular structural formula of the anthracene-based fluorescent polymer, m = 15 and n = 85. The 1H NMR spectrum of the obtained anthracene-based fluorescent polymer is as shown in the appendix of the specification Figure 6 as shown.

[0056] Example 4 was the same as Example 1, except that the preparation method of the anthracene-based fluorescent polymer in Example 2 was as follows:

[0057] In a three-necked flask, 2 mmol of yellow compound II (i.e., anthracene diamine monomer), 8 mmol of methylphenylenediamine and 10 mmol of benzophenone tetracarboxylic dianhydride (CAS No.: 2421-28-5) were added. Then, 20 mL of m-cresol was added as a solvent. After that, the temperature of the reaction system was raised to 190 °C. Then, 0.4671 g of isoquinoline was added as a catalyst to the reaction system, and the mixture was stirred for 4 h. After the reaction was completed, the reaction solution was poured into 250 mL of absolute ethanol. After the solid product in the solution settled completely naturally, the solution was filtered and washed, and then dried in a blast dryer at 60 °C for 12 h and then dried in vacuo at 200 °C for 2 h to obtain the anthracene-based fluorescent polymer. In the molecular structural formula of the anthracene-based fluorescent polymer, m = 20 and n = 80. The 1H NMR spectrum of the obtained anthracene-based fluorescent polymer is as shown in the appendix of the specification Figure 7 as shown.

[0058] Solubility experiment

[0059] The anthracene-based fluorescent polymer obtained in Example 1 was dissolved in N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone, dimethyl sulfoxide solvent, chloroform, and tetrahydrofuran at room temperature, respectively.

[0060] The anthracene-based fluorescent polymer obtained in Example 2 was dissolved in N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone, dimethyl sulfoxide solvent, chloroform, and tetrahydrofuran at room temperature, respectively.

[0061] The anthracene-based fluorescent polymers obtained in Example 3 were separately dissolved in N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone, dimethyl sulfoxide solvent, chloroform, and tetrahydrofuran at room temperature. At room temperature, 10 mg of the anthracene-based fluorescent polymer swelled in 1 mL of chloroform and tetrahydrofuran.

[0062] The anthracene-based fluorescent polymers obtained in Example 4 could be dissolved in N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone, dimethyl sulfoxide solvent, chloroform, and tetrahydrofuran at room temperature.

[0063] The summary of the solubility of the anthracene-based fluorescent polymers obtained in Examples 1-4 of the present invention in different organic solvents is shown in Table 1.

[0064] Table 1

[0065]

[0066] Specific applications

[0067] (1) Preparation of fluorescent probes

[0068] 1.041 g of the anthracene-based fluorescent polymers obtained in Examples 1-4 were separately dissolved in 10 mL of N,N-dimethylacetamide, and the obtained fluorescence intensities were 41938, 34689, 27551, and 18571, respectively.

[0069] (2) Preparation of sensing membranes

[0070] 1.041 g of the anthracene-based fluorescent polymers obtained in Examples 1-4 were separately dissolved in 10 mL of N,N-dimethylacetamide to prepare a 10 wt% fluorescent polymer solution. After filtering the solution, it was cast on the surface of a 5×5 cm glass plate with a scraper and baked at 100 °C for 8 h to obtain anthracene-based polymer sensing membranes, respectively.

[0071] Inspired by the ideal embodiments of the present invention described above, through the above description, relevant staff can completely make various changes and modifications without departing from the technical idea of the present invention. The technical scope of the present invention is not limited to the content in the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. An anthracene-based fluorescent polymer, characterized in that, It has the following structural formula: ， In the above structural formula, m = 5 - 20 and n = 80 - 95.

2. The anthracene-based fluorescent polymer according to claim 1, wherein The preparation method includes the following steps: (1) Add 9,10-dibromoanthracene and 3-nitrobenzeneboronic acid to a reactor. Under nitrogen protection, add solvent I, reducing agent I, and catalyst I. Raise the temperature of the reaction system to 80 °C, then add a phase transfer agent and an aqueous sodium carbonate solution, and then raise the temperature of the reaction system to 105 °C. Stir and react for 4 - 8 h to end the reaction. After the reaction ends, the reaction solution is distilled under reduced pressure to remove the solvent and water in the reaction system. The reaction product is purified by a silica gel chromatography column and then vacuum dried at 120 °C for 6 h to obtain yellow compound I. The chemical structural formula of the yellow compound is as follows: ； (2) Place yellow compound I in a reactor. Under nitrogen protection, add solvent II, reducing agent II, and catalyst II to the reaction system. Then raise the temperature of the reaction system to 90 - 100 °C and stir and react for 5 - 7 h. When the reaction system becomes clear and transparent black, after the reaction ends, filter while it is hot to remove catalyst II and reducing agent II. Let the filtrate stand still until solid substances in the filtrate precipitate, and then collect the solid product by filtration. Then vacuum dry it at 60 °C for 12 h to obtain yellow compound II. The chemical structural formula of the yellow compound II is as follows: ； (3) Under nitrogen protection, add yellow compound II, 2,6-diaminotoluene, and 3,3',4,4'-benzophenonetetracarboxylic dianhydride to a reactor, and then add solvent III and catalyst III. Raise the temperature of the reaction system to 170 - 200 °C and stir and react for 3 - 4 h. After the reaction ends, pour the reaction solution into absolute ethanol for natural sedimentation. After the sedimentation ends, filter the reaction solution to remove solvent III. The obtained solid product is washed and dried to obtain an anthracene-based fluorescent polymer.

3. The anthracene-based fluorescent polymer according to claim 2, characterized in that, In step (1), the molar ratio of 9,10-dibromoanthracene to 3-nitrobenzeneboronic acid is 1:

2.

4. The anthracene-based fluorescent polymer according to claim 2, wherein In step (1), the reducing agent I is sodium carbonate, and the addition amount is 2 times the mass of 9,10-dibromoanthracene; In step (1), the catalyst I is tetrakis(triphenylphosphine)palladium, and the addition amount is 0.1 - 0.3 times the mass of 9,10-dibromoanthracene; In step (1), the solvent I is toluene, and the addition amount is 2 - 5 times the mass of 9,10-dibromoanthracene; In step (1), the phase transfer agent is ethylene glycol dimethyl ether, and the addition amount is 2 - 5 times the mass of 9,10-dibromoanthracene; In step (1), the mass concentration of the aqueous sodium carbonate solution is 10%, and the addition amount is 2 - 5 times the mass of 9,10-dibromoanthracene.

5. The anthracene-based fluorescent polymer according to claim 2, characterized in that, In step (2), the solvent II is ethylene glycol methyl ether, and the addition amount is 5 - 10 times the mass of yellow compound I; In step (2), the reducing agent II is hydrazine hydrate, and the addition amount is 0.1 times the mass of yellow compound I; In step (2), the catalyst II is palladium-carbon catalyst, and the addition amount is 0.1 - 0.3 times the mass of yellow compound I.

6. The anthracene-based fluorescent polymer according to claim 2, wherein In step (3), the solvent III is m-cresol, and the addition amount is 5 - 10 times the mass of yellow compound II; In step (3), the catalyst III is isoquinoline, and the mass concentration of isoquinoline in m-cresol is 1 - 4%; In step (3), the total molar amount of 2,6-diaminotoluene and 3,3',4,4'-benzophenonetetracarboxylic dianhydride is equal to the molar amount of the yellow compound II.

7. A fluorescent probe, characterized in that, Using the anthracene-based fluorescent polymer obtained by any one of claims 1-6 as a fluorophore, the preparation method includes the following preparation steps: Mix the anthracene-based fluorescent polymer with an organic solvent evenly so that the anthracene-based fluorescent polymer is completely dissolved in the organic solvent, and a fluorescent probe solution is obtained. The mass concentration of the fluorescent probe solution is 2-8%.

8. A fluorescent probe according to claim 7, wherein The organic solvent includes at least one of N,N-dimethylacetamide, N,N-dimethylformamide, chloroform, tetrahydrofuran, N-methylpyrrolidone, and dimethyl sulfoxide.

9. A fluorescence sensing film, characterized in that, Using the anthracene-based fluorescent polymer obtained by any one of claims 1-6 as a fluorescent substance, the preparation method includes the following steps: Mix the anthracene-based fluorescent polymer with an organic solvent so that the anthracene-based fluorescent polymer is completely dissolved in the organic solvent to obtain a fluorescent coating. The mass concentration of the anthracene-based fluorescent polymer in the organic solvent is 10-15%. Then coat the fluorescent coating on the surface of the substrate and then place it in a vacuum drying oven for drying to obtain a fluorescent sensing film.

10. A fluorescence sensing film according to claim 9, characterized in that, The vacuum drying temperature is 100 °C and the drying time is 6-8 h.

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