Aggregation-induced emission tetra (3-pyridine biphenyl) vinyl blue light-emitting organic salt and preparation method thereof

Abstract

The invention discloses an aggregation-induced emission tetra (3-pyridine biphenyl) vinyl blue light-emitting organic salt and a preparation method thereof, and relates to the technical field of chemical materials. According to the method, tetraphenylethylene cations (T3Py-TPEBr4) are obtained from commercially available products through simple synthesis steps, then the tetraphenylethylene cations (T3Py-TPEBr4) and aromatic sulfonic acid anionic compounds (divalent or tetravalent) are prepared into blue luminous organic salt crystals through a one-pot method, and the quantum yield can be close to 100%. The wide application of the organic material in the fields of photoelectric devices, fluorescence sensing, light storage and the like is expected to be realized.

Description

Technical Field

[0001] The invention relates to the technical field of chemical materials, and belongs to the synthesis of a eutectic of tetrakis(3-pyridylbiphenyl)vinyl cation and an aromatic di / tetravalent sulfonic acid anion with a blue light-emitting function. Background Art

[0002] Fluorescent materials play an important role in contemporary materials science and optoelectronics. They have attracted much attention due to their diverse luminescence properties and key functions in multiple fields such as display technology, bioimaging, sensor technology, and optoelectronic devices. They are particularly widely used in the field of display technology. Displays usually contain three main colors: red, green, and blue, each with a specific bandgap range. Among them, blue light, specifically, is visible light with a wavelength between 400 and 500nm. It is often called high-energy visible light and plays a key role in display technology and lighting devices due to its ability to enhance color brightness and saturation. Blue light is particularly important because it is the shortest wavelength and highest energy part of the visible spectrum. However, the development of blue light emitting materials is still relatively immature due to the contradiction between optical and electrical properties, which limits the development of efficient blue light fluorescent materials. Therefore, researchers are actively exploring new materials and innovative design strategies to improve the performance of blue light emitters.

[0003] Tetraphenylethylene (TPE) is favored by researchers because of its unique luminescence properties and structural diversity. It is a blue light-emitting molecule. However, its quantum yield is relatively low, usually less than 20%, which limits its application in the field of high-efficiency luminescent materials. To overcome this limitation, researchers have tried to synthesize TPE-based metal organic frameworks (MOFs), covalent organic frameworks (COFs), and TPE-based organic molecules to improve the luminescence performance of blue light-emitting materials. The emission wavelength of these TPE-based blue fluorescent materials ranges from 400–500nm, and their quantum efficiencies are usually between 1.02% and 99%. However, the synthesis process of these materials is relatively complicated. In this context, it is particularly important to explore more efficient and simplified blue light-emitting material design and synthesis strategies. Summary of the invention

[0004] In order to solve the problems in the prior art, the present invention provides an efficient multicolor luminescent organic salt of aggregation-induced luminescence and a preparation method thereof, and the technical solution adopted is:

[0005] Since the bond energy of ionic bonds in organic salts is second only to covalent bonds and has the characteristics of long-range and non-directional, it is not only conducive to the formation of complex organic salt crystal structures, but also convenient for achieving efficient ionic self-assembly and improving the stability of its assembled structure under simplified experimental conditions. Therefore, firstly, organic salt aggregates are obtained by mixing the following solutions of organic cations and organic anions at a certain concentration. The molecular structure involved is as follows:

[0006]

[0007] The anion of the pyridinium salt is Br - The cations of sulfonic acid are H + .

[0008] During the aggregation process, the organic cation and organic anion solutions use deionized water as solvent. The two aqueous solutions are mixed with vigorous stirring, and the stirring state is maintained for a period of time to make the reaction between the two more thorough. It should be noted that the reaction bottle needs to be screwed on to prevent the solvent from volatilizing.

[0009] Further, the preparation method of the cation and anion precipitation is as follows:

[0010] Aqueous solutions of T3Py-TPEBr4 and sulfonic acid anion compounds at a concentration of 10 or 15 mg / mL were prepared, and the T3Py-TPEBr4 solution was mixed with different anion solutions (1,5-NDSH2, BPDSH2, TPMSH4, TPADSH4) according to the charge stoichiometric ratio to achieve the purpose of charge balance of anions and cations. The suspension was then stirred for 24 h and centrifuged to obtain organic salt aggregates, which were washed with deionized water and dried in a vacuum oven set at 25°C.

[0011] Furthermore, after the mixed solution of organic cations and organic anions is stirred for 24 hours, it is kept in an oven at 95°C-99°C for 3 hours-5 hours to accelerate the chemical reaction.

[0012] Furthermore, the temperature is set to drop to 25°C after 30h-75h.

[0013] Furthermore, the single crystal cultivation of the organic salt is completed in a programmed cooling process. Aqueous solutions of organic cations and organic anions are prepared separately at room temperature. After the two are mixed, they are heated or different solvents are added to increase the solubility of the substances, and then programmed cooling is performed. After the end, crystal growth can be observed, or the solution after the cooling is completed is volatilized at room temperature to obtain the target eutectic. The solvent is methanol and / or N,N-dimethylformamide.

[0014] The advantages and beneficial effects of the present invention are:

[0015] The present invention provides a simple method (pyridinium cation T3Py-TPE 4+ ) and four divalent / quaternary anion aromatic sulfonate ligands. After the aqueous solution of pyridinium cation and sulfonate anion is mixed, it will completely polymerize into organic salt within a few seconds to a few minutes, with a yield of more than 90%. The emission peak position of the organic salt crystal can reach 465nm at the bluest, and the blue light quantum yield (Φ f ) reached nearly 100%. It provides new directions and strategies for the future development of new optoelectronic materials with excellent performance from organic salt materials and promotes research progress in related fields. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 Prepared in Example 1 The unit cell diagram of .

[0017] Figure 2 Prepared in Example 2 The unit cell diagram of .

[0018] Figure 3 Prepared in Example 3 The unit cell diagram of .

[0019] Figure 4 Prepared in Example 4 The unit cell diagram of .

[0020] Figure 5 The chromaticity diagrams are of the organic salt crystals and the organic salt aggregate precipitates involved in Examples 1-4.

[0021] Figure 6 These are the emission spectra of the organic salt crystals and organic salt aggregate precipitates involved in Examples 1-4.

[0022] Figure 7 Involved in Example 2 Quantum yield of organic salt crystals. DETAILED DESCRIPTION

[0023] The technical solution of the present invention is further described below in conjunction with the accompanying drawings.

[0024] The high-efficiency multicolor luminescent organic salt of aggregation-induced luminescence provided by the present invention is obtained through strong anion-cation interaction, which is different from the traditional covalent bond interaction. It is prepared by single crystal cultivation. The biphenyl disulfonic acid (sulfonic acid anion abbreviated as BPDS) involved in the 2- ), 1,5-naphthalene disulfonic acid (sulfonic acid anion referred to as 1,5-NDS 2- ), tetraphenylmethanesulfonic acid (sulfonic acid anion referred to as TPMS 4- ), adamantane sulfonic acid (sulfonic acid anion referred to as TPADS 4-) are all commercially available compounds.

[0025] The tetrakis(3-pyridylbiphenyl)vinyl bromide salt (cation part referred to as T3Py-TPE) of the present invention 4+ ) The tetrakis(3-pyridylbiphenyl)ethylene (T3PPE) required for the synthesis is also commercially available, and the synthesis of tetrakis(3-pyridylbiphenyl)vinyl bromide thereof has been reported in the literature.

[0026] The fluorescence emission chromaticity diagram coordinates of all organic salt aggregate precipitations and crystals included in the present invention are shown in Table 1:

[0027] Table 1

[0028]

[0029] Embodiment 1: Single crystal preparation:

[0030] Add 5 mL of 1 mg / mL T3Py-TPEBr4 aqueous solution to a 20 mL glass bottle, then add 2 mL of 1 mg / mL BPDSH2 aqueous solution, then put the mixed solution into a preheated 95 °C oven and keep it warm for 3 hours, then set the program to cool down to 25 °C after 69 hours, and after the cooling is completed, you can see flake crystals growing.

[0031] Embodiment 2: Single crystal preparation:

[0032] Method 1: Add 5 mL of 1 mg / mL T3Py-TPEBr4 aqueous solution to a 40 mL glass bottle, then add 12.5 mL of anhydrous methanol and 5 mL of 1 mg / mL 1,5-NDSH2 aqueous solution, place the open glass bottle on a preheated 40°C hot plate to evaporate to precipitation, then use a pipette to transfer 10 mL of deionized water, place the solution in a preheated 99°C oven and keep it warm for 5 hours, then set the program to cool down to 25°C after 75 hours, filter with a microporous filter membrane (25 mm, 0.22 μm), and the filtrate will evaporate at room temperature for about three weeks before needle-shaped crystals grow.

[0033] Method 2: Add 2 mL of 1 mg / mL T3Py-TPEBr4 aqueous solution to a 20 mL glass bottle, then add 5.5 mL of anhydrous methanol and 2 mL of 1 mg / mL 1,5-NDSH2 aqueous solution, place the mixed solution in a preheated 99 °C oven and keep it warm for 3 hours, then set the program to cool down to 25 °C after 70 hours, filter with a microporous filter membrane (25 mm, 0.22 μm), and the filtrate evaporates at room temperature for about a month before growing needle-shaped crystals.

[0034] Embodiment 3: Single crystal preparation:

[0035] Add 1 mL of 1 mg / mL T3Py-TPEBr4 aqueous solution to a 10 mL glass bottle, then add 5.5 mL of anhydrous methanol and 1 mL of 1 mg / mL TPMSH4 aqueous solution, place the mixed solution in a preheated 99 °C oven and keep it warm for 3 h, then set the program to cool down to 25 °C after 30 h, filter with a microporous filter membrane (25 mm, 0.22 μm), and the filtrate evaporates at room temperature for about a week before growing block crystals.

[0036] Embodiment 4: Single crystal preparation:

[0037] Add 2 mL of 1 mg / mL T4Py-TPEBr4 aqueous solution to a 30 mL high temperature resistant glass bottle, then add 4 mL of deionized water, 2 mL of 1 mg / mL TPADSH4 aqueous solution, then add 4 mL of deionized water, 800 μL of N,N-dimethylformamide, and 1 mL of anhydrous methanol. Place the mixed solution in a preheated 99 °C oven for 3 hours, set the program to cool down to 25 °C after 60 hours, filter the solution after the cooling is completed, and the filtrate will grow flaky crystals after about two weeks of evaporation at room temperature.

[0038] The single crystal structures synthesized in Examples 1 to 4 are as follows Figure 1-4 As shown, the relevant parameters after data collection and structure refinement are summarized in Table 2 below:

[0039] Table 2

[0040]

[0041] Through the above examples, the present invention provides a simple and efficient strategy to construct tetrakis(3-pyridylbiphenyl)vinyl bromide (T3Py-TPE 4+ ) and four di / tetravalent anionic aromatic sulfonate ligands. The yield is as high as over 90% (97.36%) ( Figure 7 ), which is an extremely high luminous efficiency in the field of blue luminescence of organic salts. Moreover, the fluorescence emission wavelength of these organic salt crystals shows a significant blue shift relative to that of organic salt precipitation ( Figure 6 The emission colors of these compounds can be determined from the CIE chromaticity diagram ( Figure 5 ) can be more intuitively observed that the luminescence of the organic salt crystals is in the blue luminescence area, and there is an obvious blue shift relative to the aggregation and precipitation of the organic salt. The CIE coordinate position is shown in Table 1.

Claims

1. Aggregation-induced luminescence tetrakis(3-pyridylbiphenyl)vinyl blue luminescent organic salt, characterized by: The organic salt is dominated by ionic bonds, and the structural formulas of organic cations and organic anions are as follows: The anion of the pyridinium salt is Br - The cations of sulfonic acid are H + .

2. The method for preparing the blue luminescent organic salt of tetrakis(3-pyridylbiphenyl)vinyl with aggregation-induced emission according to claim 1, characterized in that: The solution of the organic cation and the organic anion is prepared with deionized water as solvent. The two aqueous solutions are mixed with vigorous stirring, and the stirring state is maintained for a period of time so that the two can react completely.

3. The method for preparing the blue luminescent organic salt of tetrakis(3-pyridylbiphenyl)vinyl with aggregation-induced emission according to claim 2, characterized in that: The organic salt single crystal is obtained by cooling the mixed solution system or by volatilizing at room temperature after the cooling step is completed.

4. The method for preparing the tetrakis(3-pyridylbiphenyl)vinyl blue luminescent organic salt of aggregation-induced luminescence according to claim 2, characterized in that: The molar equivalents of the organic cations and the organic anions are controlled and proportioned according to the charge ratio.

5. The method for preparing the tetrakis(3-pyridylbiphenyl)vinyl blue luminescent organic salt of aggregation-induced luminescence according to claim 2, characterized in that: The organic cation solution and the organic anion are mixed with different anion solutions to achieve the purpose of charge balance of the anion and cation precipitation.

6. The method for preparing the tetrakis(3-pyridylbiphenyl)vinyl blue luminescent organic salt of aggregation-induced luminescence according to claim 2, characterized in that: Methanol and / or N,N-dimethylformamide are added to obtain a mixed solvent system to increase the solubility of the substance.

7. The method for preparing the tetrakis(3-pyridylbiphenyl)vinyl blue luminescent organic salt of aggregation-induced luminescence according to claim 2, characterized in that: After the mixed solution of organic cations and organic anions is stirred, it is kept at a fixed temperature for a certain period of time to accelerate the chemical reaction rate.

8. The method for preparing the tetrakis(3-pyridylbiphenyl)vinyl blue luminescent organic salt of aggregation-induced luminescence according to claim 2 or 7, characterized in that: The mixed solution of organic cations and organic anions is stirred for 24 hours and then kept in an oven at 95°C-99°C for 3 hours-5 hours.

9. The method for preparing the tetrakis(3-pyridylbiphenyl)vinyl blue luminescent organic salt of aggregation-induced luminescence according to claim 2 or 8, characterized in that: Set the program to cool down to 25℃ after 30h-75h.

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