HK1236984A - A green dyestuff having an aggregate-induced luminescent property - Google Patents

Description

Green dye with aggregation-induced emission property

Technical Field

The invention relates to a novel organic color conversion film material for plane display, in particular to a green dye containing tetraphenylethylene groups and having aggregation-induced emission properties, which is prepared into a thin film by solution spin coating and can be applied to plane display.

Background

With the continuous breakthrough of display industry technology and the increasing market demand, flat panel displays rapidly rise with a series of advantages of small size, light weight, power saving, small radiation, good electromagnetic compatibility and the like, and become the mainstream of display technology in the 21 st century. The color formation of the flat panel display plays an important role in the production process, and the quality of the color formation directly determines the color development effect, the production cost and the service life of the flat panel display.

At present, the mainstream technology for realizing color display of a flat panel display is to print red, green and blue tricolor fluorescent materials to prepare devices, however, the color cast of the color display is easily caused due to the large difference of the service life and the attenuation degree of the tricolor fluorescent materials, and the manufacturing process of the tricolor devices is complex and has high cost. In order to solve these problems, a new concept of color conversion, namely "blue source coloring", is proposed. The blue source color forming technology adopts a single high-brightness blue phosphor as a backlight source, and blue light emitted by the backlight source is converted into red light and green light through a color conversion film, so that RGB full-color display is realized. The technology not only can greatly simplify the production process of the electroluminescent flat panel display, improve the color stability and uniformity of the display, but also can obviously reduce the production cost of the display. Materials for color conversion films can be classified into two major categories, inorganic and organic. Research shows that compared with inorganic fluorescent powder, the organic conversion material has higher color conversion efficiency and more saturated color, so that a wider color gamut can be realized, the raw materials are cheap and easy to obtain, and molecular cutting and modification are easier to perform so as to obtain a better display effect.

In the 90 s of the 20 th century, the Leising group used Coumarin dye Coumarin 102 as a green material, and Lumogen F300 as a red dye dispersed in PMMA to prepare green and red light conversion films, and the red light conversion efficiency of more than 10% was obtained (reference: Adv. Mater.,1997,9(1), 33-36). In recent years, the preparation of organic light conversion films has been reported by domestic research groups (references: Optoelectronics Letters,2010,6(4), 245-.

The organic fluorescent color conversion film generally disperses organic fluorescent dyes with different colors in a high molecular solid film uniformly by means of ultraviolet curing or thermosetting and the like, then excites dye molecules in the organic fluorescent color conversion film by a high-brightness blue backlight source to realize color conversion, and red light, green light and blue light of a background obtained by conversion form three primary colors of light, and finally full-color display of an electroluminescent element can be realized.

However, in these light conversion film materials, the organic dye is generally dispersed in a transparent polymer resin at a very low concentration (several thousandths), and an excessively low concentration tends to result in insufficient light absorption by the film, so that the film thickness must be increased to obtain a sufficient light conversion effect, thereby increasing the thickness of the entire display panel.

The concept of aggregation-induced emission (AIE) is proposed by Tang-loyal academy of hong Kong scientific university, the AIE type molecule has very high quantum yield in solid state, the solid state Quantum Yield (QY) of the molecule composed of benzothiadiazole and tetraphenylethylene reaches 89% (refer to chem. Commun.,2011,47, 8847-8849), and the molecule is widely applied to bioluminescent probes, ion detection, oled luminescent layer materials and the like, however, the application of the molecule in organic light conversion film materials is not reported, and the high quantum yield of the AIE type molecule in solid state makes the application of the molecule in the field have natural advantages.

Disclosure of Invention

Aiming at the light conversion film material, the invention provides green dye molecules with Aggregation Induced Emission (AIE) properties, and the green dye molecules are dispersed in high polymer resin such as methyl methacrylate (PMMA) and the like to be cured to prepare the light conversion film.

A green dye with aggregation-induced emission property has a molecular structure shown in formula (I),

wherein R1 and R2 independently represent hydrogen, C1-C8 alkyl, C1-C8 alkoxy or halogen; ar independently represents an alkyl substituted or unsubstituted carbon-carbon double bond or triple bond, a C6-C30 benzene ring or a heterocycle, both vicinal and unvicinal, and n is an integer between 0 and 3.

Preferably: wherein R1 and R2 independently represent hydrogen, C1-C4 alkyl or alkoxy, Ar independently represents a carbon-carbon double bond or a triple bonded or unbonded C6-C20 benzene ring or heterocyclic aromatic ring, and n is an integer between 0 and 2.

Preferably: r1 and R2 are the same.

Preferably: r1 and R2 are hydrogen and tert-butyl.

Preferably: wherein R1 and R2 preferably represent hydrogen, tert-butyl, Ar independently represents and is not limited to the aromatic or heterocyclic rings listed below, and n is an integer between 0 and 2:

the compound of formula (I) is preferably a compound having the following structure:

synthesis of green dye GA 1:

in the first step, a phenyl methane derivative and a benzophenone derivative are condensed to prepare the brominated tetraphenylethylene.

In the second step, butyl lithium is used for substitution reaction to prepare the tetraphenylethylene borate.

And thirdly, preparing a target dye molecule GA1 through a Suzuki coupling reaction.

Synthesis of green dye GA 2:

in the first step, the diphenyl substituted benzothiadiazole is prepared by Suzuki coupling reaction.

In the second step, liquid bromine is used for bromination.

And thirdly, preparing a target dye molecule GA2 through a Suzuki coupling reaction.

The light conversion film consists of the green light dye and cured high polymer resin.

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

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

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

The application comprises the steps of dissolving the green-light dye and the cured high polymer resin in toluene, then spin-coating to form a film, drying, curing to prepare the organic light conversion film, fixing the organic light conversion film on a backlight source, and applying the organic light conversion film to planar 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.

Experiments showed that CCF films prepared with GA1 and GA2 were resistant to background blue light (. lamda.)_maxAbout 450nm) has good absorption, emits green light, and has weak fluorescence in solution (QY) of GA1 and GA2<50%) and shows strong fluorescence after being made into solid or PMMA film, the invention applies AIE type dye molecules to organic light conversion film material for the first time, and the strong luminescence of the dye in solid state is applied to the organic light conversion film material and has great advantages.

Drawings

FIG. 1 schematic diagram of the synthetic route of the green dye GA1 of the present invention

FIG. 2 is a schematic diagram of the synthesis scheme of the green dye GA2 of the present invention;

FIG. 3 UV-VISIBLE ABSORPTION SPECTRUM OF GREEN DYE GA1 OF THE INVENTION IN TOluene, DICHLOROEROMETER, AND PMMA THIN FILM AND SOLID STATE

FIG. 4 shows fluorescence emission spectra of the green dye GA1 of the present invention in toluene, dichloromethane, and PMMA thin film and solid state;

FIG. 5 UV-VISIBLE absorption spectra of the green dye GA2 of the present invention in toluene, dichloromethane, and PMMA film and solid state;

FIG. 6 shows fluorescence emission spectra of the green dye GA2 of the present invention in toluene, dichloromethane, and PMMA thin film and solid state;

FIG. 7A light conversion film made of the green dye GA1 of the present invention.

Detailed Description

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

Synthesis of green dye GA 1:

in the first step, a phenyl methane derivative and a benzophenone derivative are condensed to prepare the brominated tetraphenylethylene.

In the second step, butyl lithium is used for substitution reaction to prepare the tetraphenylethylene borate.

And thirdly, preparing a target dye molecule GA1 through a Suzuki coupling reaction.

Synthesis of green dye GA 2:

in the first step, the diphenyl substituted benzothiadiazole is prepared by Suzuki coupling reaction.

In the second step, liquid bromine is used for bromination.

And thirdly, preparing a target dye molecule GA2 through a Suzuki coupling reaction.

Example 1 synthesis of green dye GA 1:

(1) synthesis of Compound 3a

The synthesis steps are as follows: after compound 1a (commercially available) (5.61g,20mmol) was dissolved in anhydrous THF (100mL) under nitrogen, the reaction was cooled to 0 deg.C, butyllithium (2.2M,14mL) was slowly added dropwise with stirring, and stirring at low temperature was continued for 1h, compound 2a (commercially available) (10.45g,40mmol) was added to the reaction solution, and stirring at low temperature was continued for 1 h. The reaction was then warmed to room temperature and stirred overnight.

And (3) post-reaction treatment: after the reaction, the reaction mixture was poured into water, EA (100mL × 3) was extracted and separated, and 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

The synthesis steps are as follows: the crude compound 3a obtained in the previous step is dissolved in anhydrous toluene (50mL) under the protection of nitrogen, and then TSOH is added to the reaction solution^.H₂O (380mg,2mmol), heated to reflux for 12 h and TLC checked for completion of compound 3a reaction. And (3) post-reaction treatment: the reaction was stopped, the reaction solution was poured into water, EA (100mL × 2) was extracted and separated, and the organic layers were combined, dried over anhydrous sodium sulfate, and evaporated to dryness under reduced pressure. The crude product is subjected to column chromatography to obtain light yellowCompound 4a (5.7g, 54.5% yield).¹H NMR(400MHz,CHLOROFORM-d)＝7.23-7.15(m,2H),7.15-7.04(m,7H),7.04-6.83(m,8H),1.29-1.25(m,9H),1.24(s,13H)。

(3) Synthesis of Compound 5a

The synthesis steps are as follows: compound 4a (5.7g,10.9mmol), Pd (dppf) Cl under nitrogen₂(400mg, 5%), bis (pinacolato) borate (4.2g,16.4mmol), potassium acetate (2.1g,21.8mmol) were dissolved in anhydrous 1, 4-dioxane (70mL), and then the reaction solution was heated to reflux temperature with stirring for 12 hours, and compound 4a was detected by TLC to be completely reacted.

And (3) post-reaction treatment: the reaction was stopped, the reaction solution was poured into water, EA (100mL × 2) was extracted and separated, and the organic layers were combined, dried over anhydrous sodium sulfate, and evaporated to dryness under reduced pressure. Column chromatography of the crude product gave compound 5a (5.7g, 54.5% yield) as a pale yellow solid.¹HNMR(400MHz,CHLOROFORM-d)＝7.52(d,J＝8.1Hz,2H),7.11-7.01(m,10H),6.97-6.88(m,5H),1.32(s,9H),1.26-1.23(m,21H)。

(4) Synthesis of GA1

The synthesis steps are as follows: to a 250mL reaction flask was added compound 5a (627mg,1.1mmol), compound 6a (commercially available) (147mg,0.5mmol), Pd₂(dba)₃(51mg, 5%), tri-tert-butylphosphine (22mg, 10%), K₂CO₃(304mg,2.2mmol), toluene (5mL) and water (1 mL). The nitrogen was evacuated 3 times, heated to 100 ℃ and maintained at this temperature for 12 hours, and compound 5a was detected by TLC to be completely reacted.

And (3) post-reaction treatment: stopping heating, cooling to 20 deg.C, pouring the reaction solution into water, extracting with ethyl acetate (50 mL. multidot.2), separating, combining organic layers, drying with anhydrous sodium sulfate, and evaporating under reduced pressure. Column chromatography of the crude product gave compound GA1(0.35g, 68.6% yield) as a pale yellow solid.

¹H NMR(400MHz,CHLOROFORM-d)＝7.74(s,2H),7.72(d,J＝1.8Hz,4H),7.17(s,2H),7.15(d,J＝3.8Hz,4H),7.13-7.08(m,16H),7.02(d,J＝8.3Hz,4H),6.96(d,J＝8.3Hz,4H),1.25(s,36H)。

Example 2 synthesis of green dye GA 1:

(1) synthesis of Compound 3b

The synthesis steps are as follows: a250 mL reaction flask was charged with Compound 6a (commercially available) (2.93g,10mmol), Compound 2b (commercially available) (2.68g,22mmol), Tetratriphenylphosphine palladium (1.15g, 5%), K₂CO₃(4.14g,30mmol), toluene (100mL) and water (20 mL). The nitrogen was evacuated 3 times, heated to 80 ℃ and maintained at this temperature for 8 hours, and compound 6a was detected by TLC to be completely reacted.

And (3) post-reaction treatment: stopping heating, cooling to 20 ℃, pouring the reaction solution into water, extracting and separating by EA (100mL × 3), combining organic layers, drying by anhydrous sodium sulfate, and then evaporating to dryness under reduced pressure. Column chromatography of the crude product gave compound 3b (2.3g, 79.8% yield) as a pale yellow solid.¹H NMR(400MHz,CHLOROFORM-d)＝7.97(d,J＝7.2Hz,4H),7.80(s,2H),7.61-7.53(m,4H),7.51-7.43(m,2H)。

(2) Synthesis of Compound 4b

The synthesis steps are as follows: compound 3b (2.3g,8.0mmol) was dissolved in 50mL of chloroform, liquid bromine (2.82g,17.6mmol) was added dropwise to the reaction mixture with stirring at room temperature, and after completion of the addition, stirring was continued overnight at room temperature, and completion of the reaction of Compound 3b was detected by TLC.

And (3) post-reaction treatment: the reaction solution was poured into a saturated aqueous sodium hydrogen sulfite solution, and dichloromethane (50mL × 3) was used to extract the separated liquid, and the organic layers were combined, dried over anhydrous sodium sulfate, and evaporated to dryness under reduced pressure. Column chromatography of the crude product gave compound 4b (2.2g, 49.3% yield) as a pale yellow solid.¹H NMR(400MHz,CHLOROFORM-d)＝7.86(d,J＝8.4Hz,4H),7.78(s,2H),7.68(d,J＝8.4Hz,4H)。

(3) Synthesis of GA2

The synthesis steps are as follows: into a 250mL reaction flask was added compound 4b (223mg,0.5mmol), 5a (627mg,1.1mmol), Pd₂(dba)₃(51mg, 5%), tri-tert-butylphosphine (22mg, 10%), K₂CO₃(304mg,2.2mmol), toluene (5mL) and water (1 mL). The nitrogen was evacuated 3 times, heated to 100 ℃ and maintained at this temperature for 12 hours, and compound 4b was detected by TLC to be completely reacted.

And (3) post-reaction treatment: stopping heating, cooling to 20 deg.C, pouring the reaction solution into water, extracting with ethyl acetate (50 mL. multidot.2), separating, combining organic layers, drying with anhydrous sodium sulfate, and evaporating under reduced pressure. Column chromatography of the crude product gave compound GA2(0.42g, 71.6% yield) as a pale yellow solid.¹H NMR(400MHz,CHLOROFORM-d)＝8.03(d,J＝8.3Hz,4H),7.86-7.81(m,2H),7.74(d,J＝8.4Hz,4H),7.42(d,J＝8.3Hz,4H),7.15-7.08(m,22H),6.98(dd,J＝8.4,15.7Hz,8H),1.27(s,18H),1.26(s,18H)。

Example 3 photophysical property testing of green dyes GA1 and GA 2:

the photophysical properties of the green dyes GA1 and GA2 in solution were tested by dissolving the respective dyes in toluene or dichloromethane at a concentration of 1 × 10^-5mol/L, dye-based CCF film is prepared by mixing a dye and a phasePMMA with a corresponding proportion is dissolved in toluene, the PMMA is prepared by spin coating and then drying, and the photophysical property of the dye film is measured after the dye is dissolved in THF and then is spin-coated to prepare the film. CCF films prepared with GA1 and GA2 against background blue light (. lamda.) (B)_maxAbout 450nm) has good absorption, emits green light, and has weak fluorescence in solution (QY) of GA1 and GA2<50%) and shows strong fluorescence after being made into solid or PMMA film, and has typical AIE property.

Claims (10)

1. A green dye with aggregation-induced emission property has a molecular structure shown in formula (I),

wherein R1 and R2 independently represent hydrogen, C1-C8 alkyl, C1-C8 alkoxy or halogen; ar independently represents an alkyl substituted or unsubstituted carbon-carbon double bond or triple bond, a C6-C30 benzene ring or a heterocycle, both vicinal and unvicinal, and n is an integer between 0 and 3.

2. The green dye according to claim 1, wherein R1 and R2 independently represent hydrogen, C1-C4 alkyl or alkoxy, Ar independently represent a carbon-carbon double bond or a triple bond C6-C20 benzene ring or heterocyclic aromatic ring, and n ═ an integer between 0 and 2.

3. The green dye of claim 2, R1, R2 being the same.

4. The green dye of claim 3, R1 and R2 represent hydrogen, tert-butyl.

5. The green dye according to claim 1, wherein R1 and R2 represent hydrogen, tert-butyl, Ar independently represents one of the aromatic rings listed below, n ═ an integer between 0 and 3:

6. the green dye according to claim 5, which is a compound having the following structure:

7. a synthesis method of green dye GA1, according to claim 6, comprising the following steps:

in the first step, a benzene methane derivative and a benzophenone derivative are condensed to prepare brominated tetraphenylethylene,

in the second step, butyl lithium is used for substitution reaction to prepare tetraphenylethylene borate,

and thirdly, preparing a target dye molecule GA1 through a Suzuki coupling reaction.

8. A synthesis method of green dye GA2, according to claim 6, comprising the following steps:

firstly, preparing diphenyl substituted benzothiadiazole by Suzuki coupling reaction,

in the second step, liquid bromine is used for bromination reaction,

and thirdly, preparing a target dye molecule GA2 through a Suzuki coupling reaction.

9. The use of the green dye of any of claims 1-6 in a light conversion film, wherein the green dye and the cured polymer resin are dissolved in toluene, spin-coated to form a film, dried and cured to prepare an organic light conversion film, and the organic light conversion film is fixed on a backlight source and used in a flat panel display to realize full color display.

10. The use according to claim 9, wherein the cured polymer resin is acrylate, epoxy resin or polyurethane, the curing preparation method is thermal curing or ultraviolet curing, and the backlight source is a blue light source.