Organic fluorescent small molecules containing pyridine betaine and aggregation-induced emission effector groups and their applications

Abstract

The present invention relates to an organic fluorescent small molecule containing a pyridine betaine and an aggregation-induced emission effector group and application thereof. The chemical structural formula of the organic fluorescent small molecule is any one of the following or a combination of any several of them: #imgabs0#, etc.; wherein R is independently selected from any one of hydrogen, fluorine, chlorine, bromine and iodine, and R1, R2 and R3 are independently selected from any one of pyridine, thiophene, furan, tetraphenylethylene, tetrathienylethylene, halogen, OH, NO2, CN, SH, NH2, CF3, OCF3, optionally substituted C1-C12 alkyl, optionally substituted C1-C12 haloalkyl, optionally substituted C2-C12 alkyl, optionally substituted C2-C12 heteroalkyl, optionally substituted C3-C12 cycloalkyl, optionally substituted C2-C12 heterocycloalkyl, optionally substituted C1-C18 heteroaryloxy, optionally substituted C1-C12 alkylamino or acyl. Compared with the prior art, the invention has better photoluminescence quantum yield and aggregation-induced emission effect, simple synthesis steps, good stability, etc.

Description

Technical Field

[0001] The invention belongs to the technical field of fluorescent materials, and relates to an organic fluorescent small molecule containing pyridine betaine and an aggregation-induced emission effector group and application thereof. Background Art

[0002] Fluorescent solar concentrator is an optical device that controls the light transmission process to achieve the convergence of sunlight. It is composed of fluorescent materials, transparent optical waveguide medium and solar cells. The fluorescent material absorbs the incident sunlight, and the generated fluorescence is transmitted to the side-coupled solar cell by total reflection from the optical waveguide medium, and then converted into electrical energy by the solar cell. Fluorescent solar concentrator has the following advantages: 1. It can absorb both direct sunlight and scattered light in the environment, without the need for expensive sunlight tracking systems; 2. Long-wave light energy can pass through the device, avoiding the problem of excessive device temperature caused by high light irradiation intensity after concentration; 3. Strong stability and durability; 4. The device has the characteristics of transparency and adjustable color, which can expand the application scope of traditional photovoltaic power generation systems, meet the light transmittance and aesthetic requirements of glass exterior walls, and can also generate photovoltaic power, build green buildings, and ultimately achieve energy conservation and emission reduction goals.

[0003] Fluorescent dyes, the most important part of fluorescent solar concentrators, are currently mainly divided into organic dyes and inorganic quantum dot materials. Organic dyes are mainly improvements on the structure of traditional organic dyes, and still have obvious disadvantages such as complex synthesis, narrow absorption spectrum, and serious self-absorption. Another fluorescent material, inorganic quantum dot fluorescent dyes, have poor stability, easy decomposition under light conditions (such as perovskite quantum dots, etc.), low photoluminescence quantum yield, low light collection efficiency (such as carbon quantum dots, etc.), some quantum dots are highly toxic, and the preparation process is complex (such as cadmium telluride, cadmium sulfide, copper indium selenide, lead sulfide and other quantum dots). The disadvantages are also not suitable for the application of building materials. Based on this, the present invention synthesizes a series of organic fluorescent small molecules containing pyridine betaine and aggregation-induced emission effector groups. Summary of the invention

[0004] The purpose of the present invention is to provide an organic fluorescent small molecule containing a pyridine betaine and an aggregation-induced emission effector group and its application, wherein the molecule has at least one of the advantages of aggregation-induced emission performance, simple synthesis, good thermal stability, high fluorescence quantum yield, long Stokes shift and easy derivatization.

[0005] The purpose of the present invention can be achieved by the following technical solutions:

[0006] One of the technical solutions of the present invention provides an organic fluorescent small molecule containing a pyridine betaine and an aggregation-induced emission effector group, and its chemical structural formula is any one of the following or any combination of several thereof:

[0007]

[0008] wherein R is independently selected from any one of hydrogen, fluorine, chlorine, bromine and iodine, and R1, R2 and R3 are independently selected from any one of pyridine, thiophene, furan, tetraphenylethylene, tetrathienylethylene, halogen, OH, NO2, CN, SH, NH2, CF3, OCF3, optionally substituted C1-C12 alkyl, optionally substituted C1-C12 haloalkyl, optionally substituted C2-C12 heteroalkyl, optionally substituted C3-C12 cycloalkyl, optionally substituted C2-C12 heterocycloalkyl, optionally substituted C1-C18 heteroaryloxy, optionally substituted C1-C12 alkylamino or acyl ; R4, R5 and R6 are independently selected from pyridine, thiophene, furan, tetraphenylethylene, tetrathienylethylene, halogen, OH, NO2, CN, SH, NH2, CF3, OCF3, optionally substituted C1-C12 alkyl, optionally substituted C1-C12 haloalkyl, optionally substituted C2-C12 heteroalkyl, optionally substituted C3-C12 cycloalkyl, optionally substituted C2-C12 heterocycloalkyl, optionally substituted C1-C18 heteroaryloxy, optionally substituted C1-C12 alkylamino or any one of acyl; R7 can be optionally substituted C1-C12 alkyl or aryl.

[0009] Furthermore, R1 = R2 = R3. In this case, the product synthesis is simple, the synthesis steps are short, and a stable single product can be obtained.

[0010] Furthermore, R4 = R5 = R6. In this case, the product synthesis is simple, the synthesis steps are short, and a stable single product with stable performance can be obtained.

[0011] Furthermore, R1 = R2 = R3 = pyridine. In this case, the product synthesis is simple, the synthesis steps are short, and a stable single product with stable performance can be obtained.

[0012] Furthermore, R4 = R5 = R6 = benzene. In this case, the product synthesis is simple, the synthesis steps are short, and a stable single product with stable performance can be obtained.

[0013] Furthermore, the chemical structure of the organic fluorescent small molecule is selected from any one or a combination of the following:

[0014]

[0015]

[0016] Furthermore, when the organic fluorescent small molecules are first dissolved in a good solvent and then a poor solvent is added, aggregates with significantly enhanced fluorescence intensity will be formed.

[0017] Furthermore, the good solvent may be tetrahydrofuran, dichloromethane, or the like.

[0018] Furthermore, the poor solvent is water or n-hexane.

[0019] The second technical solution of the present invention provides the application of an organic fluorescent small molecule containing a pyridine betaine and an aggregation-induced emission effector group, characterized in that the organic fluorescent small molecule is used in a fluorescent solar concentrator.

[0020] Compared with the prior art, the present invention has the following advantages:

[0021] (1) The molecule has both aggregation-induced emission and fluorescence properties in thin film and solid states;

[0022] (2) Simple synthesis, convenient for industrial production;

[0023] (3) Good thermal stability, thermal decomposition temperature can reach 300℃;

[0024] (4) It has a high fluorescence quantum yield, and some molecular components can reach 100%;

[0025] (5) Longer Stokes shift;

[0026] (6) The synthesis method is flexible and easy to derive. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic diagram of the process flow of the present invention.

[0028] Figure 2 This is the hydrogen nuclear magnetic resonance spectrum (400 MHz, CDCl3, 300 K) of compound 1 obtained in Example 1.

[0029] Figure 3 This is the hydrogen nuclear magnetic resonance spectrum (400 MHz, CDCl3, 300 K) of compound 2 obtained in Example 1.

[0030] Figure 4 This is the hydrogen nuclear magnetic resonance spectrum (400 MHz, CDCl3, 300 K) of compound 3 obtained in Example 1.

[0031] Figure 5 This is the hydrogen nuclear magnetic resonance spectrum (400 MHz, CDCl3, 300 K) of compound 4 obtained in Example 2.

[0032] Figure 6 This is the hydrogen nuclear magnetic resonance spectrum (400 MHz, CDCl3, 300 K) of compound 5 obtained in Example 2.

[0033] Figure 7This is the fluorescence spectrum of compound 2 obtained in Example 1 under the conditions of 0% water / THF to 90% water / THF.

[0034] Figure 8 This is the fluorescence spectrum of compound 3 obtained in Example 1 under the conditions of 0% water / THF to 90% water / THF.

[0035] Fig. 9 This is the fluorescence spectrum of compound 3 obtained in Example 1 under the conditions of 0% hexane / THF to 90% hexane / THF.

[0036] Fig.10 The fluorescence spectra of compound 3 obtained in Example 1 in different solvents.

[0037] Fig.11 This is the fluorescence spectrum of compound 5 obtained in Example 2 under the conditions of 0% water / THF to 90% water / THF.

[0038] Fig.12 This is the fluorescence spectrum of compound 5 obtained in Example 2 in different solvents.

[0039] Fig.13 This is the fluorescence spectrum of compound 5 obtained in Example 2 under the conditions of 0% hexane / THF to 90% hexane / THF.

[0040] Fig.14 The UV spectra of compound 3 obtained in Example 1 in different solvents.

[0041] Fig.15 The UV spectra of compound 5 obtained in Example 2 in different solvents. DETAILED DESCRIPTION

[0042] The present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. This embodiment is implemented based on the technical solution of the present invention, and provides a detailed implementation method and specific operation process, but the protection scope of the present invention is not limited to the following embodiments.

[0043] In the following examples, unless otherwise specified, raw materials or processing techniques are conventional commercially available raw materials or conventional processing techniques in the art.

[0044] Embodiment 1:

[0045] See also Figure 1 The process flow shown in the figure, this embodiment provides a method for synthesizing an aggregation-induced emission organic molecule based on a pyridine betaine group, using the following steps:

[0046] 1) Compound 1 was synthesized according to the literature. (Reference: VINikolayenko, DC Castell, DP van Heerden, LJ Barbour, Angew. Chem. Int. Ed. 2018, 57, 12086.)

[0047] 2) A mixture of 4-(4-bromo-5-methylthiophenol)pyridine (compound 1, 400 mg, 1.57 mmol), 4,4,5,5-tetramethyl-2-(4'-(1,2,2-triphenylvinyl)-[1,1'-biphenyl]-4-yl)-1,3,2-dioxaborane (1.09 g, 2.05 mmol), CaCO3 (870.08 mg, 6.3 mmol) and Pd(PPh3)4 (90.94 mg, 0.078 mol) was dissolved in distilled water (4 mL) and tetrahydrofuran (12 mL) under nitrogen atmosphere. The obtained mixture was stirred at 80°C for 24 hours. After cooling to room temperature, it was extracted with dichloromethane, dried over anhydrous Na2SO4 and filtered. The filtrate was concentrated under reduced pressure and chromatographed on a silica gel column using ethyl acetate / petroleum ether (1:4, v / v) as the eluent to obtain a transparent solid compound 2 (800 mg, 87.37%)

[0048] 3) Compound 2 (160 mg, 0.276 mmol) was dissolved in a mixed solution of 2 ml tetrahydrofuran and 1 ml water, stirred at 0°C for 5 min, then octafluorocyclopentene (58.5 mg, 0.276 mmol) was added, the solution was stirred at 0°C for 20 minutes, then slowly returned to room temperature to react overnight. The solution was concentrated under reduced pressure, the yellow precipitate was collected, and finally washed with ethyl acetate to obtain a yellow solid compound 3 (150 mg, 72%).

[0049] Figure 2 1H-NMR chart of the prepared compound 1.

[0050] Figure 3 1H-NMR chart of the prepared compound 2.

[0051] Figure 4 1H-NMR chart of the prepared compound 3.

[0052] Embodiment 2:

[0053] See also Figure 1 The process flow shown in the figure, this embodiment provides a method for synthesizing an aggregation-induced emission organic molecule based on a pyridine betaine group, using the following steps:

[0054] 1) Compound 1 was synthesized according to the literature. (Reference: VINikolayenko, DC Castell, DP van Heerden, LJ Barbour, Angew. Chem. Int. Ed. 2018, 57, 12086.)

[0055] 2) A mixture of 4-(4-bromo-5-methylthiophenol)pyridine (200 mg, 0.78 mmol), 4,4,5,5-tetramethyl-2-(4-(1,2,2-triphenylvinyl)phenyl)-1,3,2-dioxaborane (468 mg, 1.02 mmol), CaCO3 (433 mg, 3.15 mmol) and Pd(PPh3)4 (45.7 mg, 0.039 mmol) was dissolved in distilled water (4 mL) and tetrahydrofuran (12 mL) under a nitrogen atmosphere. The resulting mixture was stirred at 80°C for 24 hours. After cooling to room temperature, it was extracted with dichloromethane, dried over anhydrous Na2SO4, and filtered. After the filtrate was concentrated under reduced pressure, it was chromatographed on a silica gel column with ethyl acetate / petroleum ether (1:4, v / v) as the eluent to obtain a transparent solid compound 4 (250 mg, 62.8%).

[0056] 3) Compound 4 (150 mg, 0.296 mmol) was dissolved in a mixed solution of 2 ml tetrahydrofuran and 1 ml water, stirred at 0°C for 5 min, then octafluorocyclopentene (60.0 mg, 0.296 mmol) was added, the solution was stirred at 0°C for 20 minutes, then slowly returned to room temperature to react overnight. The solution was concentrated under reduced pressure, the yellow precipitate was collected, and finally washed with ethyl acetate to obtain a yellow solid compound 5 (139 mg, 70%).

[0057] Figure 5 1H-NMR chart of the prepared compound 4. Figure 6 1H-NMR chart of the prepared compound 5.

[0058] Figure 7 The fluorescence spectrum of the prepared compound 2 under the conditions of 0% water / THF to 90% water / THF is shown. It can be clearly seen that as the water content, i.e., the poor solvent, increases, its fluorescence performance becomes better and better, indicating that it does have the aggregation-induced emission effect.

[0059] Figure 8 This is the fluorescence spectrum of compound 3 obtained in Example 1 under the conditions of 0% water / THF to 90% water / THF. It can be clearly seen that as the water content, i.e., the poor solvent, increases, its fluorescence performance becomes better and better, indicating that it does have the aggregation-induced emission effect.

[0060] Fig. 9 The fluorescence spectrum of compound 3 obtained in Example 1 under the conditions of 0% hexane / THF to 90% hexane / THF is shown. It can be clearly seen that as the content of n-hexane, i.e., the poor solvent, increases, its fluorescence performance becomes better and better, indicating that it does have the aggregation-induced emission effect.

[0061] Fig.10 The fluorescence spectra of compound 3 obtained in Example 1 in different solvents.

[0062] Fig.11 This is the fluorescence spectrum of compound 5 obtained in Example 2 under the conditions of 0% water / THF to 90% water / THF. It can be clearly seen that as the water content, i.e., the poor solvent, increases, its fluorescence performance becomes better and better, indicating that it does have the aggregation-induced emission effect.

[0063] Fig.12 This is the fluorescence spectrum of compound 5 obtained in Example 2 in different solvents.

[0064] Fig.13 This is the fluorescence spectrum of compound 5 obtained in Example 2 under the conditions of 0% hexane / THF to 90% hexane / THF. It can be clearly seen that as the content of n-hexane, i.e., the poor solvent, increases, its fluorescence performance becomes better and better, indicating that it does have the aggregation-induced emission effect.

[0065] Fig.14 The UV spectra of compound 3 obtained in Example 1 in different solvents are shown. It can be seen that as the polarity of the solvent increases, a certain red shift is exhibited.

[0066] Fig.15 The UV spectra of compound 5 obtained in Example 2 in different solvents are shown. It can be seen that as the polarity of the solvent increases, a certain red shift is exhibited.

[0067] Table 1 shows the crystal data of compound 3 obtained in Example 1 and compound 5 obtained in Example 2. The details of the two compounds can be seen in more detail. For example, the unit cell types of both are triclinic system; the number of molecules in the unit cell is 4 and 2 respectively.

[0068]

[0069]

[0070] Comparative Examples 1-3:

[0071] Compared with Example 1, most of them are the same, except that the palladium catalyst used in step (2) is adjusted to an equimolar amount of palladium acetate, bis(triphenylphosphine)palladium dichloride or 1,1'-bis(diphenylphosphinothiocene)palladium dichloride. The yields are reduced to 62%, 74.6% and 65.5%, respectively.

[0072] Comparative Examples 4-5:

[0073] Compared with Example 1, most of the steps are the same, except that in step (2), the base used is adjusted to an equimolar amount of sodium carbonate or potassium phosphate, and the yields are reduced to 77.5% and 78.6%, respectively.

[0074] Comparative Examples 6-8:

[0075] Compared with Example 2, most of them are the same, except that the palladium catalyst used in step (2) is adjusted to an equimolar amount of palladium acetate, bis(triphenylphosphine)palladium dichloride or 1,1'-bis(diphenylphosphinothiocene)palladium dichloride. The yields are reduced to 59.2%, 60% and 71.5%, respectively.

[0076] Comparative Example 9:

[0077] Compared with Example 1, most of the steps are the same except that the stirring is carried out at room temperature in step (3). The yield is reduced to 32%.

[0078] The above description of the embodiments is to facilitate the understanding and use of the invention by those skilled in the art. It is obvious that those skilled in the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative work. Therefore, the present invention is not limited to the above embodiments, and improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the present invention should be within the scope of protection of the present invention.

Claims

1. An organic fluorescent small molecule containing a pyridine betaine and an aggregation-induced emission effector group, characterized in that: Its chemical structure is any of the following: 、 。 2. The use of the organic fluorescent small molecule containing pyridine betaine and aggregation-induced emission effector group as claimed in claim 1, characterized in that: The organic fluorescent small molecule is used in a fluorescent solar concentrator.

Images