CN100425599C - Organic electroluminescent material and its application - Google Patents

Abstract

The present invention relates to a novel compound and an organic electroluminescent device comprising the compound. The structure general formula of the compound is as following: n is an integer from one to four; Ar and Ar' are respectively and independently selected from hydrogen atoms, replacing or non-replacing aromatic radical, heterocyclic ring aromatic radical, condensed ring aromatic radical or fused heterocycle aromatic radical. In addition, Ar and Ar' are not simultaneously hydrogen atoms. R1 and R2 are respectively selected from halogen atoms, replacing or non-replacing alkyl group, alkoxyl group, alkyl group of amino group, alkyl sulphide radical, aromatic group or heterocyclic ring aromatic group. The present invention overcomes problems of color purity, luminous efficiency, etc. of the existing generally used luminescent material. The material of the present invention can be preferentially used as a luminous body and is independently used as a luminescent layer or doped dye for emitting light. In addition, the present invention can be used for electronic transmission and hole barrier material simultaneously. The electroluminescent device prepared by utilizing the material of the present invention presents high performance of high color purity, high brightness and high efficiency.

Description

A kind of organic electroluminescent material and its application

technical field

The invention relates to an organic electroluminescence material and its application in an organic electroluminescence device, belonging to the technical field of organic electroluminescence display.

Background technique

Organic electroluminescent devices (hereinafter referred to as organic EL) are widely used in various fields due to their ultra-thin, fully cured, self-luminous, fast response, good temperature characteristics, and flexible display.

Research on organic EL began in the 1960s. In 1963, Pope et al. (J.Chem.Phys.1963, 38:2042～2043) studied the blue electroluminescence of anthracene single crystal (10～20μm), because the anthracene single crystal light-emitting layer was thick and the electrodes used Due to the constraints of materials (silver colloid and sodium chloride solution), the luminous starting voltage of the device is as high as 400V, and the efficiency and brightness are low. However, the discovery opens up a new field of light-emitting technology. In the following two decades, the research on organic EL has progressed slowly. It was not until 1987 that C.W.Tang et al. (Appl. Phys. Lett. 1987, 51: 913-915) of Kodak Corporation of the United States made a milestone breakthrough. They adopted a double-layer device with 8-hydroxyquinoline aluminum (Alq3) as the light-emitting layer, aromatic diamine as the hole transport layer, ITO as the anode, and Mg:Ag (10:1) alloy as the cathode. High quantum efficiency (1%) and luminous efficiency (1.5lm/W): devices with high brightness (>1000cd/m2) and lower driving voltage (≤10V). This progress has reawakened the application of organic EL in full-color flat panel displays The research of materials and devices has rapidly become a research hot spot. In 1988, Adchi et al. [J.Appl.Phys.1988,27(2):L269～L271] introduced a multi-layer sandwich structure, which greatly expanded the organic EL material selection range.

After 20 years of development, organic EL materials have fully realized red, blue, and green luminescence, and the application field has also expanded from small molecules to polymers and metal complexes. Theoretically, organic electroluminescent display technology has matured, and some products have entered the market, but there are still many problems to be solved in the process of commercialization. Especially for various organic materials used to make devices, many problems have not been solved, such as carrier injection, transport performance, material electroluminescence performance, service life, color purity, matching between materials and electrodes, etc. . At the same time, new materials with better performance are constantly being discovered and used, and device manufacturing technology and device performance are constantly improving.

The basic structure of an organic EL device includes anode/hole injection and transport layer/organic light-emitting layer/electron injection layer/cathode. Attenuation is quite fast, so it is still difficult to apply to actual production.

Contents of the invention

The object of the present invention is to provide a novel organic electroluminescent material having excellent luminous efficiency and heat resistance, long life and excellent color purity of emission, and an organic electroluminescent device using the material.

After long-term research, the inventors have discovered that the benzoxadiazole compound with a specific structure has good thermal stability, high-efficiency luminescence performance, simple synthesis method and purification steps, and then applies it to the device, and the obtained The device has high color purity and efficiency. It is based on this recognition that the invention has been accomplished.

The present invention proposes a compound represented by the following general formula:

Wherein n is an integer of 1-4, Ar and Ar' are independently selected from hydrogen atoms, substituted or unsubstituted aromatic groups, heterocyclic aromatic groups, fused ring aromatic groups or fused heterocyclic aromatic groups, and Ar and Ar' are not hydrogen atoms at the same time;

R ₁ and R ₂ are respectively selected from the same or different halogen atoms, or selected from the same or different substituted or unsubstituted alkyl, alkoxy, alkylamino, alkylthio, aryl or heterocyclic aromatic base.

In the above structural formula, Ar and Ar' are preferably hydrogen atoms; preferably aryl or substituted aryl groups containing C _6-20 , such as phenyl, naphthyl, biphenyl, p-terphenyl, anthracenyl, bianthryl , p-tert-butylphenyl, 2,4-difluorophenyl, 4-(N,N-dimethylamino)phenyl, etc., among which the most preferred are naphthyl, p-terphenyl, anthracenyl; It is preferably a condensed ring aryl group containing C _6-20 such as pyrenyl, naphthacene, phenanthrenyl, triphenylene, benzanthracene, benzopyrenyl, fluorenyl, etc., wherein the most preferred is pyrenyl, Benzanthryl, fluorenyl; preferably heterocyclic aryl or condensed heterocyclic aryl containing C _4-20 such as pyridyl, quinolinyl, benzothienyl, benzofuran, indolyl, benzimidazole base, benzothiazolyl, etc., among which the most preferred are pyridyl and quinolinyl.

In the above structural formula, R ₁ and R ₂ are respectively selected from hydrogen atom, C _1-30 alkyl or substituted alkyl, C _1-30 alkoxy or substituted alkoxy, C _2-30 alkylamino Or substituted alkylamino, such as methyl, trifluoromethyl, ethyl, isopropyl, tert-butyl, methoxy, ethoxy, isopropoxy, tert-butyloxy, N,N- Dimethylamino, N, N-diethylamino; C _1-30 alkylthio or substituted alkylthio, such as methylthio, ethylthio, isopropylthio, tert-butylthio ; C _6-20 aryl or substituted aryl, C _6-20 fused ring aryl or C _4-20 heterocyclic aryl or fused heterocyclic aryl, such as phenyl, naphthyl, biphenyl, Pyrenyl, fluorenyl, pyridyl, quinolinyl.

In order to describe the content of the present invention more clearly, the preferred structures of the types of compounds involved in the present invention are specifically described below but not limited.

i, Ar and Ar' are the same, and are aryl or condensed ring aryl, and the molecular structure is symmetrical:

ii. Ar is the same as Ar', which is a heterocyclic aryl group or a condensed heterocyclic aryl group:

iii. Ar is different from Ar', each is an aryl group, a substituted aryl group, a heterocyclic aryl group or a condensed heterocyclic aryl group

The material of the present invention has the following advantages:

The organic electroluminescent material of the present invention can be preferentially used as a luminescent body, including as a luminescent layer alone, or as a doped dye to emit light, and can also be used as an electron transport and hole blocking material at the same time.

The organic electroluminescent device prepared by using the luminescent material of the invention can exhibit superior performances of high purity, high brightness and high efficiency.

Description of drawings

Fig. 1 is the mass spectrogram of material 4 of the present invention, 7-two (4'-biphenyl)-2,1,3-benzoxadiazole (compound i-4);

Fig. 2 is the electroluminescence figure of device OLED-1～OLED-3;

FIG. 3 is an electroluminescence diagram of devices OLED-4-OLED-5.

Detailed ways

Preferred embodiment: the compounds of the present invention are all prepared by reacting aryl or heterocyclic aryl boronic acid with the precursor of dibromobenzoxadiazole compounds.

Preparation of raw material arylboronic acid:

Most of the aryl boronic acid raw materials used in the present invention are purchased from Bailingwei Company, and the parent body of dibromobenzoxadiazole and part of aryl boronic acid are synthesized according to the following method.

Synthesis of 4-biphenylboronic acid:

Reaction formula:

Process: In a 100ml three-neck flask equipped with magnetic stirring, reflux condenser and nitrogen protection device, dissolve 5.83 grams of 4-bromobiphenyl (0.025mol) in 20mlTHF, add 0.85 grams of magnesium chips (0.035mol), 0.5ml bromoethane, warm to start the reaction, reflux for 2 hours. Cool 3.12 grams (3.25ml, 0.03mol) of trimethyl borate to -5°C to -10°C with an ice-salt bath, slowly add 4-bromobiphenyl Grignard reagent under nitrogen protection, and maintain the temperature of the reaction flask Below 0°C, the addition was completed and stirred at room temperature for 12 hours. Add hydrochloric acid solution (5ml concentrated hydrochloric acid, 15ml water) dropwise, stir for 30 minutes, extract with ethyl acetate, separate the organic layer, which is yellow, and extract the aqueous layer with 2×50ml ethyl acetate, combine the organic layers, wash with saturated salt Wash with water until neutral, dry over anhydrous magnesium sulfate, and spin dry to obtain an oily liquid, which is hot-washed with 60 ml of petroleum ether to obtain 3.2 g of pale white powdery solid 4-biphenylboronic acid with a yield of 65%.

Other aryl boronic acids were synthesized in the same way.

Preparation of raw material dibromobenzoxadiazole precursor:

According to the literature Organic Syntheses, Coll.Vol.4, 74, Organic Process Research & Development2003, 7, 1043～1047, Journal of Organic Chemistry, 1974, 11, 813～814 and Russian Journal of Organic Chemistry, 2003, 39, 957～962 synthesized by the reported method.

The structural formula of each matrix when n=1～4 is as follows:

(1) Synthesis of parent 1:

i) Synthesis of 2,1,3-benzoxadiazole-N-oxides:

Add 18.0 g (321 mmol) of potassium hydroxide and 255 mL of 95% ethanol into a 1000 mL three-neck flask equipped with mechanical stirring, stir and heat to dissolve. Add 41.7 g (290 mmol) o-nitroaniline into the above hot lye, stir and dissolve to obtain a red solution. Under rapid stirring, the solution was cooled in an ice-salt bath to below 0°C, and under good stirring, 375 mL of sodium hypochlorite solution was added dropwise into the reaction system, and the temperature was controlled below 5°C. Stir for an additional 10 minutes after the addition is complete. Stop, filter with suction, wash the filter cake with water, and dry to obtain 36.1 g of a yellow solid, with a yield of 91.6%.

ii) Synthesis of 2,1,3-benzoxadiazoles:

Add 8.8 g (64.2 mmol) of benzoxadiazole-N-oxide and 40 mL of tetrahydrofuran into a 100 mL three-neck flask equipped with a nitrogen protection device, a magnetic stirrer, and a reflux condenser, and stir to dissolve. Under nitrogen protection and magnetic stirring, a solution of 20.8 g (77.0 mmol) of triphenylphosphine dissolved in 25 mL of tetrahydrofuran was slowly added dropwise from a constant pressure dropping funnel. The exothermic reaction caused the temperature to rise by itself. After the dropwise addition was completed, the stirring reaction was continued at room temperature for 18 hours. After the reaction was completed, steam distillation was carried out until no solid was distilled out. Collect the solid, dissolve it in 25 mL of hot ethanol, and slowly add the hot ethanol solution into a beaker with 120 mL of distilled water under stirring, and a large amount of white precipitates are precipitated. Filter under reduced pressure, wash with water, and dry in the air to obtain 4.3 g of white solid with a yield of 55.2%.

iii) Synthesis of 4,5,6,7-tetrabromo-2,1,3 cyclohexaneoxadiazole:

12.1 g (101.4 mmol) of benzoxadiazole, 100 mL of hydrobromic acid (47%) and 27.8 mL (506.4 mmol) of bromine were added to a 250 mL three-necked flask equipped with mechanical stirring, and the reaction was stirred at 35°C for 24 hours.

Stop responding. The reaction mixture was poured into 700 mL of 5% sodium sulfite ice-cold solution, and the brown color faded. Filter with suction, wash the solid with water, and dry to obtain an off-white solid. Recrystallized with 95% ethanol and dried under vacuum at 70°C to obtain 30.1 g of white needle-like crystals, with a yield of 67.5%.

iv) Synthesis of parent 1:

5.4 grams (12.0 mmol) of 4,5,6,7-tetrabromo-2,1,3 cyclohexane and oxadiazole, 0.009 grams (0.03 mmol) of tetrabutylammonium bromide and 30 mL of dimethyl sulfoxide Add it into a 100mL three-neck flask equipped with mechanical stirring, stir and dissolve with slight heat. While maintaining good stirring, slowly add 30 mL of 50% aqueous potassium hydroxide solution dropwise, and then stir for another 10 minutes to react.

Stop responding. Liquid separation. Add 100 mL of ethyl acetate to the upper organic phase, and wash with water until neutral. The aqueous layer was extracted with ethyl acetate (30 mL*2), washed with water, and the organic phases were combined and dried over anhydrous sodium sulfate. The dried solution was passed through a flash column with silica gel as the stationary phase, rinsed with ethyl acetate, and the solvent was evaporated to dryness to obtain brownish-yellow crystals, which were recrystallized with 85% methanol to obtain 1.5 g of colorless needle-shaped crystals, with a yield of 45.4%. .

The reaction formula is as follows:

(2) Synthesis of parent 2:

Add 0.86g (3.1mmol) of precursor 1 into a 100mL three-neck flask, under nitrogen protection, add 15mL of dry THF, and cool to -78～-80°C. Slowly add 1.94mL n-butyllithium (1.6M) and stir for 30min. Raise the temperature to -50～-45°C, then add dropwise a solution of 0.427g ZnCl ₂ dissolved in 15mL dry THF, stir after the addition and let it rise to room temperature naturally. A solution of 0.803 g (3.1 mmol) of precursor 1 and 0.0018 g (0.015 mmol) of Pd(PPh ₃ ) ₄ dissolved in 20 mL of dry THF was slowly added dropwise. Stir at room temperature for 2 h after the addition. Adjust the reaction solution to pH=7-8 with 10% NaOH solution. Suction filtration, the organic phase was separated, and the aqueous layer was extracted with 20 mL×2 ethyl acetate. The organic phases were combined, washed with water, and separated by column chromatography to obtain 0.42 g of a white solid with a yield of 35.8%.

Product MS (m/e): 395.9; elemental analysis (C ₁₂ H ₄ Br ₂ N ₄ O ₂ ): theoretical value C: 36.40, H: 1.02, N: 14.15; found value C: 36.32, H: 1.99, N : 14.03.

The reaction formula is as follows:

(3) Synthesis of parent 3:

The process is the same as (2), except that the amount of the precursor 1 in the first step remains unchanged, and the amounts of the other reagents are correspondingly increased by 1 times. 0.68 g of white solid was obtained, with a yield of 43.2%.

Product MS (m/e): 514.0; elemental analysis (C ₁₈ H ₆ Br ₂ N ₆ O ₃ ): theoretical value C: 42.05, H: 1.18, N: 16.35; found value C: 42.00, H: 1.16, N : 16.26.

The reaction formula is as follows:

(4) Synthesis of parent 4:

The process is the same as (3), except that the raw material matrix 1 in the first step is replaced with matrix 2. 0.79 g of white solid was obtained, and the yield was 40.5%.

Product MS (m/e): 632.1; elemental analysis (C ₂₄ H ₈ Br ₂ N ₈ O ₄ ): theoretical value C: 45.60, H: 1.28, N: 17.22; found value C: 45.54, H: 1.26, N : 17.16.

The reaction formula is as follows:

The following are synthetic examples of compounds of the present invention:

Example 1 4,7-diphenyl-2,1,3-benzoxadiazole (compound i-4)

Reaction formula:

process:

In a 100mL three-necked flask equipped with a magnetic stirrer, a condensing reflux device and a nitrogen protection device, 4,7-dibromobenzoxadiazole (1.50 g, 5.2 mmol), anhydrous potassium carbonate (3.59 gram, 26.0mmol), 4-biphenylboronic acid (2.52 gram, 12.5mmol), two (triphenylphosphine) palladium dichloride (0.70 gram, 1.0mmol) and by toluene, ethanol and water (volume ratio is 3: 3:2) of the mixed solution consisting of 65 mL, heated to reflux under the protection of nitrogen, and reacted for 24 hours. Remove from heat and cool to room temperature.

Pour the reaction solution into 50 mL of water, filter under reduced pressure, rinse the filter cake with water and ethyl acetate in sequence, dry the solid, and recrystallize with toluene to obtain a yellow product.

Product MS (m/e): 424.2; elemental analysis (C ₃₀ H ₂₀ N ₂ O): theoretical value C: 85.16, H: 4.90, N: 6.62; found value C: 85.13, H: 4.90, N: 6.57.

Example two 4,-bis(1-naphthyl)-2,1,3-benzoxadiazole (compound i-5)

Reaction formula:

The process is the same as in Example 1, except that the raw material is replaced with 1-naphthylboronic acid to obtain a yellow product.

Product MS (m/e): 372.4; elemental analysis (C ₂₆ H ₁₆ N ₂ O): theoretical value C: 83.85, H: 4.33, N: 7.52; found value C: 83.82, H: 4.30, N: 7.47.

Example 3 4,7-bis(2-naphthyl)-2,1,3-benzoxadiazole (compound i-6)

Reaction formula:

The process is the same as in Example 1, except that the raw material is replaced with 2-naphthylboronic acid to obtain a yellow product.

Product MS (m/e): 372.4; elemental analysis (C ₂₆ H ₁₆ N ₂ O): theoretical value C: 83.85, H: 4.33, N: 7.52; found value C: 83.80, H: 4.31, N: 7.48.

Example 4 4,7-bis(9-anthracenyl)-2,1,3-benzoxadiazole (compound i-7)

Reaction formula:

The process is the same as in Example 1, except that the raw material is replaced with 9-anthraceneboronic acid to obtain a yellow product.

Product MS (m/e): 472.5; elemental analysis (C ₃₄ H ₂₀ N ₂ O): theoretical value C: 86.42, H: 4.27, N: 5.93; found value C: 86.40, H: 4.26, N: 5.87.

Example five 4,7-bis(2'-perylenyl)-2,1,3-benzoxadiazole (compound i-9)

Reaction formula:

The process is the same as in Example 1, except that the raw material is replaced with 2-peryleneboronic acid to obtain a dark yellow product.

Product MS (m/e): 620.7; elemental analysis (C ₄₆ H ₂₄ N ₂ O): theoretical value C: 89.01, H: 3.90, N: 4.51; found value C: 88.98, H: 3.90, N: 4.46.

Example six 4,-two (1'-pyrenyl)-2,1,3-benzoxadiazole (compound i-10)

Reaction formula:

The process is the same as in Example 1, except that the raw material is replaced with 1-pyreneboronic acid to obtain a light yellow product.

Product MS (m/e): 520.5; elemental analysis (C ₃₈ H ₂₀ N ₂ O): theoretical value C: 87.67, H: 3.87, N: 5.38; found value C: 87.64, H: 3.85, N: 5.35.

Example 7 4,7-bis(5'-phenanthrenyl)-2,1,3-benzoxadiazole (compound i-11)

Reaction formula:

The process is the same as in Example 1, except that the raw material is replaced with 5-phenanthrene boronic acid to obtain a light yellow product.

Product MS (m/e): 472.5; elemental analysis (C ₃₄ H ₂₀ N ₂ O): theoretical value C: 86.42, H: 4.27, N: 5.93; found value C: 86.40, H: 4.27, N: 5.88.

Example eight 4,7-bis[(4'-benzyloxy)-4"-phenyl]-2,1,3-benzoxadiazole (compound i-12)

Reaction formula:

The process is the same as in Example 1, except that the raw material is replaced with 4-benzyloxyphenylboronic acid to obtain a light yellow product.

Product MS (m/e): 456.4; elemental analysis (C ₃₀ H ₂₀ N ₂ O ₃ ): theoretical value C: 78.93, H: 4.42, N: 6.14; found value C: 78.91, H: 4.41, N: 6.09 .

Example 9 4,7-bis(4'-(2",2"-diphenylvinyl)phenyl-2,1,3-benzoxadiazole (compound i-13)

Reaction formula:

The process is the same as in Example 1, except that the raw material is replaced with 4-(2,2-diphenylvinyl)phenylboronic acid to obtain a colored product.

Product MS (m/e): 628.7; elemental analysis (C ₄₆ H ₃₂ N ₂ O): theoretical value C: 87.87, H: 5.13, N: 4.46; found value C: 87.81, H: 5.11, N: 4.39.

Example 10 4,7-bis(9',9'-dioctylfluorene-3'-)-2,1,3-benzoxadiazole (compound i-14)

Reaction formula:

The process is the same as in Example 1, except that the raw material is replaced with 9,9-dioctylfluorene-3-boronic acid to obtain a light yellow product.

Product MS (m/e): 901.4; elemental analysis (C ₆₄ H ₈₈ N ₂ O): theoretical value C: 85.28, H: 9.84, N: 3.11; found value C: 85.23, H: 9.84, N: 3.17.

Example 11 4,4'-bis(2,4-difluorophenyl)-7,7'-bi-2,1,3-benzoxadiazole (compound i-15)

Reaction formula:

The process is the same as in Example 1, except that the raw materials are replaced with the precursor 2 and 2,4-difluorophenylboronic acid to obtain a yellow product.

Product MS (m/e): 462.3; elemental analysis (C ₂₄ H ₁₀ F ₄ N ₄ O ₂ ): theoretical value C: 62.35, H: 2.18, N: 12.12; found value C: 62.27, H: 2.17, N : 12.08.

Example twelve 4,7-bis(2'-quinolyl)-2,1,3-benzoxadiazole (compound ii-1)

Reaction formula:

The process is the same as in Example 1, except that the raw material is replaced with 2-quinolineboronic acid to obtain a light yellow product.

Product MS (m/e): 374.3; elemental analysis (C ₂₄ H ₁₄ N ₄ O): theoretical value C: 76.99, H: 3.77, N: 14.96; found value C: 76.91, H: 3.75, N: 14.94.

Example 13 4,7-two [4'-(2"-quinolyl) phenyl]-2,1,3-benzoxadiazole (compound ii-2)

Reaction formula:

The process is the same as in Example 1, except that the raw material of the first step is replaced by p-bromophenylboronic acid, and the raw material of the second step is replaced by 2-quinolineboronic acid to obtain a dark yellow product.

Product MS (m/e): 526.5; elemental analysis (C ₃₆ H ₂₂ N ₄ O): theoretical value C: 82.11, H: 4.21, N: 10.64; found value C: 82.13, H: 4.21, N: 10.58.

Example 14 4,7-two [4'-(4"-pyridyl) phenyl]-2,1,3-benzoxadiazole (compound ii-4)

Reaction formula:

The process is the same as the second step of Example 12, except that the raw material is replaced with 4-pyridineboronic acid to obtain a light yellow product.

Product MS (m/e): 426.4; elemental analysis (C ₂₈ H ₁₈ N ₄ O): theoretical value C: 78.86, H: 4.25, N: 13.14; found value C: 78.80, H: 4.23, N: 13.10.

Example fifteen 4,7-bis(N-phenylbenzindole-3'-)-2,1,3-benzoxadiazole (compound ii-5)

Reaction formula:

The process is the same as in Example 1, except that the raw material is replaced with N-phenylbenzindole-3-boronic acid to obtain a dark yellow product.

Product MS (m/e): 502.5; elemental analysis (C ₃₄ H ₂₂ N ₄ O): theoretical value C: 81.26, H: 4.41, N: 11.15; found value C: 81.20, H: 4.40, N: 11.07.

Example 16 4,7-two (2'-thienyl)-2,1,3-benzoxadiazole (compound ii-6)

Reaction formula:

The process is the same as in Example 1, except that the raw material is replaced with benzothiophene-2-boronic acid to obtain a light yellow product.

Product MS (m/e): 384.4; elemental analysis (C ₂₂ H ₁₂ N ₂ OS ₂ ): theoretical value C: 68.73, H: 3.15, N: 7.29; found value C: 68.70, H: 3.15, N: 7.32 .

Example seventeen 4-(4'-biphenyl)-7-(9-anthracenyl)-2,1,3-benzoxadiazole (compound iii-1)

Reaction formula:

The process is the same as in Example 1, except that the raw material ratio in the first step is 1:1, and the raw material is replaced with 9-anthracenboronic acid in the second step to obtain a dark yellow product.

Product MS (m/e): 448.5; elemental analysis (C ₃₂ H ₂₀ N ₂ O): theoretical value C: 85.69, H: 4.49, N: 6.25; found value C: 85.63, H: 4.48, N: 6.21.

Embodiment 18 4-(4 "-biphenyl)-7-[4 "-(2", 2 "-diphenylvinyl) phenyl]-2,1,3-benzoxadiazole ( Compound iii-5)

Reaction formula:

The process is the same as the second step in Example 16, except that the raw material is changed to 4-(2,2-diphenylvinyl)phenylboronic acid boric acid to obtain a dark yellow product.

Product MS (m/e): 526.6; elemental analysis (C ₃₈ H ₂₆ N ₂ O): theoretical value C: 86.67, H: 4.98, N: 5.32,; found value C: 86.62, H: 4.99, N: 5.27 ;.

Below are the application examples of the compounds of the present invention:

Preferred embodiment of the device:

The typical structure of an OLED device is: substrate/anode/hole transport layer (HTL)/organic light-emitting layer/electron transport layer (ETL)/cathode.

The substrate is transparent, which can be glass or flexible substrate. The flexible substrate is made of polyester and polyimide compounds; the anode layer can be made of inorganic materials or organic conductive polymers. Inorganic materials are generally Metal oxides such as indium tin oxide (hereinafter referred to as ITO), zinc oxide, tin-zinc oxide, or metals with high work functions such as gold, copper, and silver, the optimal choice is ITO, and the organic conductive polymer is preferably polythiophene/ Sodium polyvinylbenzene sulfonate (hereinafter referred to as PEDOT:PSS), polyaniline (hereinafter referred to as PANI) is a material; the cathode layer generally uses metals with low work functions such as lithium, magnesium, calcium, strontium, aluminum, and indium Or they and copper, gold, silver alloy, or the electrode layer that metal and metal fluoride form alternately, the present invention is preferably sequential Mg:Ag alloy layer, Ag layer and successive LiF layer, Al layer; Hole transport layer Generally, triarylamine materials are used, and the present invention is preferably N, N'-di-(1-naphthyl)-N, N'-diphenyl-1,1-biphenyl-4,4-diamine (NPB ); the electron transport layer is generally a metal-organic complex, preferably as three (8-hydroxyquinoline) aluminum, three (8-hydroxyquinoline) gallium, (salicylaldehyde acetal amine phenol)-(8-hydroxyquinoline) phenanthroline) gallium(III) (hereinafter referred to as Alq ₃ , Gaq ₃ , Ga(Saph-q) respectively), or o-phenanthrolines, such as 4,7-diphenyl-1,10-phenanthrole Phenyl (hereinafter referred to as Bphen), etc., the organic light-emitting layer can generally use small molecule materials, and can be doped with fluorescent materials or phosphorescent dyes. The organic light-emitting layer of the present invention includes the organic light-emitting material proposed by the present invention, which can directly emit light. It can also be used as a dye doped in the corresponding host material to emit light, and the preferred host material is Alq ₃ , Gaq ₃ , Ga(Saph-q).

Prepare a series of organic electroluminescent devices of the present invention according to the following methods:

(1) Use cleaning agent, deionized water and organic solution to clean the glass substrate with anode in several steps;

(2) Evaporating the hole transport layer of the device by vacuum evaporation;

(3) Continue to vapor-deposit the light-emitting layer comprising the red-light material of the present invention;

(4) Continue to evaporate the electron transport layer of the device;

(5) Prepare a metal cathode by evaporation or sputtering.

Example 19 Preparation of Devices OLED-1～OLED-3

Preparation of OLED-1: The glass plate coated with the ITO transparent conductive layer was ultrasonically treated in a commercial cleaning agent, rinsed in deionized water, ultrasonically degreased in acetone:ethanol mixed solvent, and baked in a clean environment until completely removed Moisture, irradiated with a UV light cleaner for 10 minutes, and bombarded the surface with a low-energy positive ion beam.

Put the above-mentioned glass substrate with an anode in a vacuum chamber, evacuate to 1×10 ^-5 ~ 9×10 ^-3 Pa, continue to evaporate NPB on the above-mentioned anode layer as a hole transport layer, and the evaporation rate 0.1nm/s, the vapor deposition film thickness is 50nm;

On the hole transport layer, continue to vapor-deposit one layer of _Alq3 doped with compound (i-4) as the light-emitting layer of the device, the evaporation rate ratio of compound (i-4) and _Alq3 is 1:100, The doping concentration of compound (i-4) in Alq ₃ is 1wt%, the total evaporation rate is 0.1nm/s, and the total evaporation film thickness is 30nm;

Continue to evaporate a layer of Alq ₃ material as the electron transport layer of the device, the evaporation rate is 0.1nm/s, and the total film thickness of evaporation is 20nm;

Finally, a Mg:Ag alloy layer and an Ag layer are sequentially evaporated on the above-mentioned electron transport layer as the cathode layer of the device, wherein the evaporation rate of the Mg:Ag alloy layer is 2.0-3.0nm/s, the thickness is 100nm, and the Ag layer The evaporation rate is 0.3nm/s, and the thickness is 100nm.

OLED-2 and OLED-3 were prepared according to the above method, only the doping concentration of compound (i-4) in _Alq3 was changed, and the performance of the device is shown in Table 1:

Table 1:

part number Device Structure Luminescence wavelength nm Current density A/m² Brightnesscd/m2 Efficiency cd/A OLED-1 ITO/NPB(50nm)/Alq₃: 1wt% compound (i-4)(30nm)/Alq₃(20nm)/MgAg:Ag 520 50 98 1.8 OLED-2 ITO/NPB(50nm)/Alq₃: 4wt% compound (i-4)(30nm)/Alq₃(20nm)/MgAg:Ag 520 50 72 1.4 OLED-3 ITO/NPB(50nm)/Alq₃: 8wt% compound (i-4)(30nm)/Alq₃(20nm)/MgAg:Ag 520 50 26 0.5

Example 20 Preparation of devices OLED-4 and OLED-5

The method is the same as in Example 18, except that the light-emitting layer is replaced by ii-2. The performance of the device is detailed in Table 2:

Table 2:

part number Device Structure Luminescence wavelength nm Current density A/m² Brightnesscd/m2 Efficiency cd/A OLED-4 ITO/NPB(50nm)/Alq₃: 1wt% compound (ii-2)(30nm)/Alq₃(20nm)/MgAg:Ag 532 50 230 4.5 OLED-5 ITO/NPB(50nm)/Alq₃: 100wt% Compound (ii-2)(30nm)/Alq₃(20nm)/MgAg:Ag 548 50 197 3.8

Although the present invention has been described in conjunction with preferred embodiments, the present invention is not limited to the above-mentioned embodiments and accompanying drawings. It should be understood that under the guidance of the inventive concept, those skilled in the art can make various modifications and improvements, and the appended The claims outline the scope of the invention.

Claims (7)

1, a kind of compound, general structure is as follows:

Wherein n is the integer of 1-4, and Ar and Ar ' are independently selected from C respectively _6-20Aryl, the C of replacement _6-20Aryl, C _6-20Fused ring aryl, C _4-20Heterocyclic aryl or C _4-20The fused heterocycle aromatic group.

According to the compound of claim 1, it is characterized in that 2, Ar is identical with Ar ', is selected from C _6-20Aryl, the C of replacement _6-20Aryl, C _6-20Fused ring aryl, C _4-20Heterocyclic aryl or C _4-20The fused heterocycle aromatic group.

According to the compound of claim 1, it is characterized in that 3, Ar is different with Ar ', independently be selected from C respectively _6-20Aryl, the C of replacement _6-20Aryl, C _6-20Fused ring aryl, C _4-20Heterocyclic aryl or C _4-20The fused heterocycle aromatic group.

4, compound according to claim 1, it is characterized in that Ar and Ar ' independently are selected from phenyl, xenyl, naphthyl, anthryl, pyrenyl, fluorenyl, naphthacenyl, pyridyl, quinolyl, benzothienyl, cumarone, indyl, benzimidazolyl-, benzothiazolyl respectively.

5, compound according to claim 1 is characterized in that, Ar and Ar ' independently are selected from the phenyl to tert-butyl-phenyl, 2,4 difluorobenzene base or 4-(N, N-dimethyl amido) respectively.

6, the application of the described compound of claim 1 in organic electroluminescence device is characterized in that as luminescent material or electric transmission and hole barrier materials.

7, a kind of organic electroluminescence device comprises first electrode and second electrode, and the organic function layer between two electrodes, it is characterized in that, the one deck at least in the organic function layer comprises the compound with following structural:

Wherein n is the integer of 1-4, and Ar and Ar ' are independently selected from C respectively _6-20Aryl, the C of replacement _6-20Aryl, C _6-20Fused ring aryl, C _4-20Heterocyclic aryl or C _4-20The fused heterocycle aromatic group.

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