TWI676656B - Having an aggregation-inducing properties of green luminescent dye and application thereof - Google Patents

Abstract

The invention relates to a green light dye with aggregation-induced luminescence properties. The structure shown in formula (I) has been tested for its photophysical properties. The molecule shown in formula (I) has a high fluorescence quantum yield in a solid state and can be applied to green light conversion film materials.

Description

Green light dye with aggregation-induced luminescence property and use thereof

The invention relates to a novel organic color conversion film material for flat display, and particularly relates to a class of green light dyes containing tetrastyrene groups with aggregation-induced luminescence properties, which are made into thin films by solution spin coating, and can be applied to flat displays.

With the continuous breakthrough of display industry technology and increasing market demand, flat panel displays have risen rapidly with a series of advantages such as small size, light weight, low power consumption, small radiation, and good electromagnetic compatibility, and have become the 21st century display technology. Mainstream. The way in which the flat panel display is made plays a very important role in its production process. Its quality directly determines the color rendering effect, production cost and service life of the flat panel display.

The current mainstream technology for flat-panel displays to achieve color display is to print red, green, and blue three-color fluorescent materials. However, due to the large differences in the life and attenuation of three-color fluorescent materials, it is easy to cause color discoloration in color displays. Moreover, the manufacturing process of the three primary color devices is relatively complicated and the cost is relatively high. In order to solve these problems, people have proposed a new idea of color conversion, namely "blue source into color". "Blue source into color" technology uses a single blue phosphor with a high brightness as the backlight source. The blue light emitted by the backlight source is converted into red and green light by a color conversion film, thereby realizing RGB full color display. This technology can not only greatly simplify the production process of electroluminescent flat display, improve the color stability and uniformity of the display, but also significantly reduce the production cost of the display. Material used for color conversion film Divided into two categories of inorganic and organic. Compared with inorganic phosphors, it has been found that organic conversion materials not only have higher color conversion efficiency, but also more saturated colors, which can achieve a wider color gamut. Moreover, raw materials are cheap and readily available, and it is easier to tailor molecules and Retouched for better display.

In the 1990s, the Leising team used Coumarin 102 as a green light material and Lumogen F300 as a red light dye dispersed in PMMA to prepare green and red light conversion films, and achieved a red light conversion efficiency greater than 10% ( References: Adv. Mater. , 1997, 9 (1), 33-36). In recent years, domestic research teams have also reported the preparation of organic light conversion films (References: Optoelectronics Letters , 2010, 6 (4), 245-248, CN105267059 A, CN103647003 A), and obtained a wide color gamut and light conversion rate. High organic light conversion film.

Organic fluorescent color conversion film generally uniformly disperses organic fluorescent dyes with different colors in a polymer solid film through UV curing or thermal curing, and then uses a high-brightness blue backlight to stimulate organic fluorescent color conversion. The dye molecules in the film are used to achieve color conversion. The converted red, green, and blue light of the background form three primary colors of light, and finally, a full-color display of the electroluminescent element can be realized.

However, the commonly used organic dyes are prone to aggregation between molecules and cause fluorescence quenching, and hardly emit light in the thin film state. Therefore, in these light conversion film materials, organic dyes are generally used at very low concentrations (a few thousandths). ) Dispersed in a transparent polymer resin, too low a concentration will often cause the film to absorb light inadequately. In order to obtain a sufficient light conversion effect, the thickness of the film must be increased, thereby causing the thickness of the entire display panel to increase.

Academician Tang Benzhong of the Hong Kong University of Science and Technology proposed the concept of aggregate-induced luminescence (AIE). These AIE-type molecules have a high quantum yield in the solid state. Molecules composed of benzothiadiazole and tetrastyrene have solid-state quantum The yield (QY) reached 89% (Reference: Chem. Commun. , 2011, 47, 8847-8849). Such molecules are widely used in biological fluorescent probes, ion detection, oled light-emitting layer materials, etc., but Its application in organic light conversion film materials has not been reported. The high quantum yield of AIE-type molecules in the solid state gives them natural advantages in this field.

Aiming at the above light conversion film material, the present invention provides a green light dye molecule having aggregation-induced luminescence (AIE) properties, which is dispersed in a polymer resin such as methyl methacrylate (PMMA) and cured to prepare a light conversion film. The invention first applied such AIE-type dye molecules to organic light conversion film materials.

A green light dye with aggregation-induced luminescence properties, and its molecular structure is as described in formula (I),

Among them, R1 and R2 are independently represented as hydrogen, C1-C8 alkyl, C1-C8 alkoxy or halogen; Ar is independently represented as alkyl-substituted or unsubstituted carbon-carbon double or triple bond C6-C30 benzene ring or heterocyclic ring, an integer between n = 0-3.

Preferably: wherein, R1 and R2 are independently represented as hydrogen, C1-C4 alkyl or alkoxy group, and Ar is independently represented as a carbon-carbon double or triple bond C6-C20 benzene ring or heterocyclic ring Aromatic ring, an integer between n = 0-2.

Preferably: R1 and R2 are the same.

Preferably: R1 and R2 are represented by hydrogen, t-butyl.

Preferably: wherein R1 and R2 are preferably represented by hydrogen, t-butyl, Ar is independently represented by and is not limited to the following aromatic rings or heterocyclic rings, and an integer between n = 0-2:

The compound described by formula (I) is preferably a compound having the following structure:

Synthesis of green light dye GA1:

In the first step, brominated tetrastyrene is prepared by condensing a benzyl methane derivative with a benzophenone derivative.

The second step uses butyl lithium to carry out the substitution reaction to prepare tetrastyrene borate.

The third step is to prepare the target dye molecule GA1 by Suzuki coupling reaction.

Synthesis of green light dye GA2:

The first step is the preparation of a bisphenyl substituted benzothiadiazole by a Suzuki coupling reaction.

The second step is bromination using liquid bromine.

The third step is to prepare the target dye molecule GA2 by Suzuki coupling reaction.

A light conversion film is composed of the above green light dye and a cured polymer resin.

The cured polymer resin is acrylate, epoxy resin or polyurethane.

The total thickness of the light conversion film is 1-100 μm.

Application of the above green light dye in a light conversion film.

The application is to dissolve the green light dye and the cured polymer resin in toluene, then spin-coat to form a film, and then cure and dry to prepare an organic light conversion film. The organic light conversion film is fixed on a backlight and applied to a flat display to realize Full color display.

The curing preparation method is thermal curing or ultraviolet curing.

The backlight source is a blue light source, and the cured polymer resin is methyl methacrylate (PMMA) polymer resin.

450nm)有很好的吸收，發射出的光為綠光，GA1和GA2在溶液中的螢光較弱(QY<50%)，製成固體或PMMA薄膜後表現出了很強的螢光，本發明首次將AIE型染料分子應用於有機光轉換膜材料，染料在固態強的發光應用於有機光轉換膜材料具有很大的優勢。 The experiments show that the CCF films prepared with GA1 and GA2 are effective against background blue light (λ _max

450nm) has good absorption, the emitted light is green, GA1 and GA2 have weak fluorescence in solution (QY <50%), and show strong fluorescence after being made into solid or PMMA film. The invention applies AIE type dye molecules to organic light conversion film materials for the first time. The strong light emission of dyes in solid state has great advantages when applied to organic light conversion film materials.

FIG. 1 is a schematic view of a synthetic route of the green light dye GA1 of the present invention; FIG. 2 is a schematic view of a synthetic route of the green light dye GA2 of the present invention; Figure 3 is the UV-visible absorption spectrum of the green light dye GA1 of the present invention in toluene, dichloromethane, and PMMA films and solids; Figure 4 is the green light dye GA1 of the present invention in toluene, dichloromethane, and PMMA films and solids Fluorescence emission spectrum; Figure 5 is the UV-visible absorption spectrum of the green light dye GA2 of the present invention in toluene, dichloromethane, and PMMA films and solid state; Figure 6 is the green light dye GA2 of the present invention in toluene, dichloromethane, and PMMA Fluorescence emission spectrum of thin film and solid state; and FIG. 7 is a light conversion film prepared by the green light dye GA1 of the present invention.

In order to describe the present invention in more detail, the following examples are given, but are not limited thereto.

Synthesis of green light dye GA1:

In the first step, brominated tetrastyrene is prepared by condensing a benzyl methane derivative with a benzophenone derivative.

The second step uses butyl lithium to carry out the substitution reaction to prepare tetrastyrene borate.

The third step is to prepare the target dye molecule GA1 by Suzuki coupling reaction.

Synthesis of green light dye GA2:

The first step is the preparation of a bisphenyl substituted benzothiadiazole by a Suzuki coupling reaction.

The second step is bromination using liquid bromine.

The third step is to prepare the target dye molecule GA2 by Suzuki coupling reaction.

Example 1 Synthesis of green light dye GA1:

(1) Synthesis of compound 3a

Synthesis step: Compound 1a (commercially available) (5.61g, 20mmol) was dissolved in anhydrous THF (100mL) under nitrogen protection, the reaction solution was cooled to 0 ° C, and butyllithium (2.2M, 14mL) was slowly added dropwise under stirring. After completion of the dropwise addition, stirring was continued at a low temperature for 1 h, and then compound 2a (commercially available) (10.45 g, 40 mmol) was added to the reaction solution, and the stirring was continued at a low temperature for 1 h. The reaction was then warmed to room temperature and stirred overnight.

Post-reaction treatment: After the reaction, the reaction solution was poured into water, and EA (100 mL * 3) was extracted and separated. The organic layers were combined, dried over anhydrous sodium sulfate, and evaporated to dryness under reduced pressure. The crude product was used in the next reaction without purification.

(2) Synthesis of compound 4a

Synthesis step: The crude product of compound 3a obtained in the previous step was dissolved in anhydrous toluene (50 mL) under the protection of nitrogen, and TOHOH ₂ O (380 mg, ₂ mmol) was added to the reaction solution, and the reaction was heated to reflux for 12 hours. The reaction of compound 3a was detected by TLC. .

Post-reaction treatment: Stop the reaction, pour the reaction solution into water, extract and separate the solution with EA (100 mL * 2), combine the organic layers, dry over anhydrous sodium sulfate, and evaporate to dryness under reduced pressure. The crude product was subjected to column chromatography to obtain a pale yellow compound 4a (5.7 g, yield 54.5%). ¹ H NMR (400MHz, CHLOROFORM-d) δ = 7.23-7.15 (m, 2 H), 7.15-7.04 (m, 7 H), 7.04-6.83 (m, 8 H), 1.29-1.25 (m, 9 H ), 1.24 (s, 13 H).

(3) Synthesis of compound 5a

Synthesis steps: Compound 4a (5.7g, 10.9mmol), Pd (dppf) Cl ₂ (400mg, 5%), bis pinacol borate (4.2g, 16.4mmol), potassium acetate (2.1 g, 21.8 mmol) was dissolved in anhydrous 1,4-dioxane (70 mL), and the reaction solution was heated to reflux temperature for 12 hours under stirring, and the reaction of compound 4a was detected by TLC.

Post-reaction treatment: Stop the reaction, pour the reaction solution into water, extract and separate the solution with EA (100 mL * 2), combine the organic layers, dry over anhydrous sodium sulfate, and evaporate to dryness under reduced pressure. The crude product was subjected to column chromatography to obtain compound 5a (5.7 g, yield 54.5%). ¹ H NMR (400MHz, CHLOROFORM-d) δ = 7.52 (d, J = 8.1Hz, 2 H), 7.11-7.01 (m, 10 H), 6.97-6.88 (m, 5 H), 1.32 (s, 9 H), 1.26-1.23 (m, 21 H).

(4) Synthesis of GA1

Synthesis steps: In a 250 mL reaction flask, add compound 5a (627 mg, 1.1 mmol), compound 6a (commercially available) (147 mg, 0.5 mmol), Pd ₂ (dba) ₃ (51 mg, 5%), tri-tert-butylphosphine ( _{22mg, 10%), K 2} CO 3 (304mg, 2.2mmol), toluene (5mL) and water (1mL). Nitrogen was evacuated three times, and the temperature was raised to 100 ° C., the temperature was maintained, and the reaction was performed for 12 hours. The reaction of compound 5a was detected by TLC.

Post-reaction treatment: Stop heating, reduce the temperature to 20 ° C, pour the reaction solution into water, extract and separate with ethyl acetate (50 mL * 2), combine the organic layers, dry over anhydrous sodium sulfate, and evaporate to dryness under reduced pressure. The crude product was subjected to column chromatography to obtain a pale yellow compound GA1 (0.35 g, yield 68.6%). ¹ H NMR (400MHz, CHLOROFORM-d) δ = 7.74 (s, 2 H), 7.72 (d, J = 1.8Hz, 4 H), 7.17 (s, 2 H), 7.15 (d, J = 3.8Hz, 4 H), 7.13-7.08 (m, 16 H), 7.02 (d, J = 8.3 Hz, 4 H), 6.96 (d, J = 8.3 Hz, 4 H), 1.25 (s, 36 H).

Example 2 Synthesis of green light dye GA1:

(1) Synthesis of compound 3b

Synthesis steps: In a 250 mL reaction flask, add compound 6a (commercially available) (2.93 g, 10 mmol), compound 2b (commercially available) (2.68 g, 22 mmol), tetratriphenylphosphine palladium (1.15 g, 5%), K ₂ CO ₃ (4.14 g, 30 mmol), toluene (100 mL) and water (20 mL). Nitrogen was evacuated three times, and the temperature was raised to 80 ° C., the temperature was maintained, and the reaction was performed for 8 hours. The reaction of compound 6a was detected by TLC.

Post-reaction treatment: Stop heating, lower the temperature to 20 ° C, pour the reaction solution into water, extract and separate the liquid with EA (100mL * 3), combine the organic layers, dry over anhydrous sodium sulfate, and evaporate to dryness under reduced pressure. The crude product was subjected to column chromatography to obtain a pale yellow compound 3b (2.3 g, yield 79.8%). ¹ H NMR (400MHz, CHLOROFORM-d) δ = 7.97 (d, J = 7.2Hz, 4 H), 7.80 (s, 2 H), 7.61-7.53 (m, 4 H), 7.51-7.43 (m, 2 H).

(2) Synthesis of compound 4b

Synthesis step: Dissolve compound 3b (2.3g, 8.0mmol) in 50mL chloroform, and add liquid bromine (2.82g, 17.6mmol) dropwise to the reaction solution with stirring at room temperature. After the dropwise addition, continue stirring at room temperature overnight. TLC detection Compound 3b reacted completely.

Post-reaction treatment: the reaction solution was poured into a saturated aqueous sodium hydrogen sulfite solution, and the mixture was extracted and separated with dichloromethane (50 mL * 3). The organic layers were combined, dried over anhydrous sodium sulfate, and evaporated to dryness under reduced pressure. The crude product was subjected to column chromatography to obtain pale yellow compound 4b (2.2 g, yield 49.3%). ¹ H NMR (400 MHz, CHLOROFORM-d) δ = 7.86 (d, J = 8.4 Hz, 4 H), 7.78 (s, 2 H), 7.68 (d, J = 8.4 Hz, 4 H).

(3) Synthesis of GA2

Synthesis steps: In a 250 mL reaction flask, add compound 4b (223 mg, 0.5 mmol), 5a (627 mg, 1.1 mmol), Pd ₂ (dba) ₃ (51 mg, 5%), tri-tert-butylphosphine (22 mg, 10%) _{, K 2 CO 3 (304mg,} 2.2mmol), toluene (5mL) and water (1mL). Nitrogen was evacuated three times, and the temperature was raised to 100 ° C., the temperature was maintained, and the reaction was performed for 12 hours. The reaction of compound 4b was detected by TLC.

Post-reaction treatment: Stop heating, reduce the temperature to 20 ° C, pour the reaction solution into water, extract and separate with ethyl acetate (50 mL * 2), combine the organic layers, dry over anhydrous sodium sulfate, and evaporate to dryness under reduced pressure. The crude product was subjected to column chromatography to obtain the pale yellow compound GA2 (0.42 g, yield 71.6%). ¹ H NMR (400MHz, CHLOROFORM-d) δ = 8.03 (d, J = 8.3Hz, 4 H), 7.86-7.81 (m, 2 H), 7.74 (d, J = 8.4Hz, 4 H), 7.42 ( d, J = 8.3 Hz, 4 H), 7.15-7.08 (m, 22 H), 6.98 (dd, J = 8.4, 15.7 Hz, 8 H), 1.27 (s, 18 H), 1.26 (s, 18 H ).

Example 3 Photophysical properties of green light dyes GA1 and GA2:

450nm)有很好的吸收，發射出的光為綠光，GA1和GA2在溶液中的螢光較弱(QY<50%)，製成固體或PMMA薄膜後表現出了很強的螢光，具有典型的AIE性質，本發明首次將AIE型染料分子應用於有機光轉換膜材料，染料在固態強的發光應用於有機光轉換膜材料具有很大的優勢。 The photophysical properties of the green dyes GA1 and GA2 in the solution were determined by dissolving the corresponding dyes in toluene or dichloromethane. The concentration of the solution was 1 × 10 ^-5 mol / L. The dye-based CCF film was the dye and the corresponding The proportion of PMMA is dissolved in toluene, prepared by spin coating and then dried. The photophysical properties of the dye film are measured after the dye is dissolved in THF and spin-coated to prepare the film. CCF film prepared with GA1 and GA2 against background blue light (λmax

450nm) has good absorption, the emitted light is green, GA1 and GA2 have weak fluorescence in solution (QY <50%), and show strong fluorescence after being made into solid or PMMA film. With typical AIE properties, the present invention applies AIE-type dye molecules to organic light conversion film materials for the first time. The strong light emission of dyes in the solid state has great advantages when applied to organic light conversion film materials.

Claims (2)

A use of a green light dye in a light conversion film is to dissolve the green light dye and a cured polymer resin in toluene, then spin-coat to form a film, and then cure and prepare an organic light conversion film, which is fixed on a backlight. The backlight source is a blue light source, and the green light dye is one of the compounds having the following structure: The use according to item 1 of the scope of the patent application, wherein the cured polymer resin is acrylate, epoxy resin or polyurethane, the curing preparation method is heat curing or ultraviolet curing, and the backlight source is Blue light source.