Quinoxaline compound containing triazine group and application thereof

Abstract

According to the quinoxaline compound containing the triazine group and the application of the quinoxaline compound containing the triazine group, the quinoxaline compound containing the triazine group has the triazine group and the quinoxaline group connected to the triazine group through a specific position, so that an organic electroluminescent device applying the compound has high efficiency, low driving voltage and long service life.

Description

Technical Field

[0001] The invention belongs to the field of organic electroluminescent materials and relates to a quinoxaline compound containing a triazine group and application thereof. Background Art

[0002] Organic electroluminescence (EL) is a self-luminescent device. When an electric field is applied, holes injected from the anode and electrons injected from the cathode recombine to emit light. Compared with traditional LCDs, organic light-emitting diodes (OLEDs) have superior display characteristics and quality, such as self-luminescence, wide viewing angle, high efficiency, wide color gamut, and flexible display. Therefore, OLEDs have become a new generation of mainstream flat-panel displays.

[0003] The structure of OLED devices generally includes anode, hole injection layer, hole transport layer, light-emitting layer, electron transport layer, electron injection layer and cathode. Therefore, high-performance OLED functional materials are selected and reasonably matched, and the material system is continuously upgraded to give full play to the comprehensive characteristics of high efficiency, long life and low voltage of the device. Organic light-emitting materials should have the following characteristics: high-efficiency fluorescence in the visible light region, high conductivity, good semiconductor properties; good film-forming properties, and the formed film has good uniformity, etc.

[0004] Therefore, in the art, it is desired to develop materials that can enable OLED devices to have lower driving voltage, high current efficiency, and long life. Summary of the invention

[0005] In view of the deficiencies of the prior art, the object of the present invention is to provide a quinoxaline compound containing a triazine group and application thereof.

[0006] To achieve this object, the present invention adopts the following technical solutions:

[0007] In one aspect, the present invention provides a quinoxaline compound containing a triazine group, wherein the quinoxaline compound containing a triazine group has a structure shown in Formula I:

[0008]

[0009] Among them, R 1 and R 2 are the same or different and are independently selected from any one of a C1-C4 straight chain alkyl group or a C1-C4 branched chain alkyl group, or R 1 and R 2 Different, one of them is selected from any one of C1-C4 straight-chain alkyl or C1-C4 branched-chain alkyl, and the other is selected from substituted or unsubstituted C6-C18 aryl;

[0010] L is a direct bond or a phenylene group;

[0011] Ar 1 -Ar 3 Independently selected from substituted or unsubstituted C6-C30 aryl groups.

[0012] The substituent in the substituted C6-C18 aryl or substituted C6-C30 aryl is selected from one or a combination of at least two of phenyl, methyl, isopropyl, isobutyl or tert-butyl.

[0013] The quinoxaline compound containing a triazine group of the present invention can make the OLED device have high efficiency, low driving voltage and long life.

[0014] In the present invention, the C1-C4 may be C1, C2, C3 or C4.

[0015] The C6-C18 may be C6, C9, C10, C12, C13, C14, C15, C16 or C18.

[0016] The C6 to C30 can each independently be C6, C9, C10, C12, C13, C14, C15, C16, C18, C20, C22, C24, C26, C28, C29, etc.

[0017] Preferably, R 1 and R 2 are the same or different and are each independently selected from methyl, ethyl, isopropyl and tert-butyl.

[0018] Preferably, R 1 and R 2 One of them is selected from methyl, ethyl, isopropyl or tert-butyl, and the other is selected from phenyl, methyl, methylphenyl, biphenyl or naphthyl.

[0019] Preferably, Ar 1 -Ar 3 Independently selected from phenyl, methylphenyl, biphenyl, dimethylfluorenyl or naphthyl.

[0020] Preferably, the triazine group-containing quinoxaline compound is any one of the following compounds:

[0021]

[0022]

[0023]

[0024] On the other hand, the present invention provides a method for preparing the above quinoxaline compound containing a triazine group, the preparation method comprising the following steps:

[0025] The intermediate was added to a three-necked flask, and potassium carbonate, tetrakis-(triphenylphosphine)palladium, toluene, ethanol and water were added at the same time, and heated under reflux for 8 hours under nitrogen protection, and then cooled to room temperature, filtered, washed, dried and recrystallized to obtain a white solid product.

[0026]

[0027] In another aspect, the present invention provides an organic electroluminescent material, which comprises the above-mentioned quinoxaline compound containing a triazine group.

[0028] In another aspect, the present invention provides an electron transport material, wherein the electron transport material comprises the triazine group-containing quinoxaline compound as described above.

[0029] In another aspect, the present invention provides an organic electroluminescent device, comprising an anode, a cathode, and an organic thin film layer between the anode and the cathode, wherein the organic thin film layer comprises the triazine group-containing quinoxaline compound as described above.

[0030] Preferably, the organic thin film layer includes any one of a hole injection layer, a hole transport layer, a light emitting layer, an electron blocking layer, an electron transport layer, a hole blocking layer or an electron injection layer, or a combination of at least two of them.

[0031] Preferably, the electron transport layer comprises the triazine group-containing quinoxaline compound as described above.

[0032] In one embodiment, the structure of the organic electroluminescent device includes in sequence: a transparent substrate layer, an anode layer, a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer / hole blocking layer, an electron injection layer, and a cathode layer.

[0033] The substrate can be a substrate in a conventional organic electroluminescent device, such as glass or plastic. The anode material can be a transparent high-conductivity material, such as indium tin oxide (ITO), indium zinc oxide (IZO), tin dioxide (SnO 2 ), zinc oxide (ZnO), etc. In the production of the organic electroluminescent device of the present invention, a glass substrate can be selected and ITO can be used as the anode material.

[0034] The hole transport region can be a single-layer structure formed by a single material, a single-layer structure formed by a plurality of different materials, or a multi-layer structure formed by a plurality of different materials. For example, the hole transport region can be a single-layer structure formed by different materials, or can have a hole injection layer / hole transport layer structure, a hole injection layer / hole transport layer / buffer layer structure, and the hole transport layer uses triarylamine materials such as N,N'-di(3-methylphenyl)-N,N'-diphenyl-[1,1-biphenyl]-4,4'-diamine (TPD) or N,N'-diphenyl-N,N'-di(1-naphthyl)-(1,1'-biphenyl)-4,4'-diamine (NPB). Among them, NPB is a commonly used hole transport material, so NPB is selected as the hole transport material in the preparation of the organic electroluminescent device of the present invention.

[0035] The structure of the organic electroluminescent device can be a single-light-emitting layer or a multi-light-emitting layer structure.

[0036] The electron transport region includes one or more of a hole blocking layer, an electron transport layer and an electron injection layer. For example, the electron transport region can have a structure of an electron transport layer / electron injection layer, a structure of a hole blocking layer / electron transport layer / electron injection layer, but is not limited thereto. The compound of the present invention is applied to the electron transport layer.

[0037] In the preparation of the organic electroluminescent device of the present invention, LiF / Al is preferably used as the cathode material.

[0038] In another aspect, the present invention provides a display panel, comprising the organic electroluminescent device as described above.

[0039] In another aspect, the present invention provides an electronic device, comprising the display panel as described above.

[0040] Compared with the prior art, the present invention has the following beneficial effects:

[0041] The triazine group-containing quinoxaline compound of the present invention has a triazine group and a quinoxaline group connected to the triazine group through a specific position, so that the organic electroluminescent device using the compound has high efficiency, low driving voltage and long life. DETAILED DESCRIPTION

[0042] The technical solution of the present invention is further described below by specific implementation methods. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0043] Example 1

[0044] Preparation of compound 37:

[0045] Intermediate A (9.5g, 0.04mol) and intermediate B (17.5g, 0.04mol) were added to a three-necked flask, and potassium carbonate (11.1g, 0.08mol), tetrakis-(triphenylphosphine) palladium (0.45g), toluene (120ml), ethanol (40ml) and water (20ml) were added at the same time, and heated to reflux for 8h under nitrogen protection. Then cooled to room temperature, filtered, washed, dried and recrystallized to obtain 12g of white target product. After purification by vacuum sublimator, the purity reached 99.95%. Mass spectrum m / z: theoretical value is 631.78; measured value is 631.27.

[0046]

[0047] Device Example:

[0048] This application embodiment provides an OLED device, whose structure includes: a transparent substrate layer, an anode layer, a hole injection layer, a hole transport layer, a light-emitting layer, an electron transport layer / hole blocking layer, an electron injection layer, and a cathode layer.

[0049] The specific structural formula of the materials used in the device is shown below:

[0050]

[0051] The specific preparation process of the above OLED device includes:

[0052] The ITO anode layer on the transparent glass substrate layer was cleaned, and ultrasonically cleaned with deionized water, acetone, and ethanol for 15 minutes each, and then treated in a plasma cleaner for 2 minutes; then HAT-CN was evaporated with a film thickness of 10 nm, which was a hole injection layer; then NPB was evaporated with a film thickness of 50 nm, which was a hole transport layer; then 40 nm of BH and BD were evaporated as a light-emitting layer; then 10 nm of TPBi was evaporated on the light-emitting layer as a hole blocking layer; then, the compound of the present invention was evaporated by vacuum evaporation with a thickness of 35 nm as an electron transport layer; on the electron transport layer, an electron injection layer LiF was vacuum evaporated with a thickness of 1 nm, which was an electron injection layer; on the electron injection layer, a cathode Al (80 nm) was vacuum evaporated, which was a cathode layer.

[0053] Comparative Example 1

[0054] The experiment was performed in the same manner as in Example, except that Compound ET was used instead of the compound of the present invention as the electron transport layer.

[0055]

[0056] The following examples 1-5 and comparative examples illustrate the application effects of the compounds synthesized by the present invention as electron transport layers in OLED devices:

[0057] Table 1

[0058]

[0059]

[0060] The device test performance is based on the comparative example, and the current efficiency is 10mA / cm 2 The life test system is Chroma's MODEL 58131 OLED device life tester.

[0061] From the above device data, it can be seen that the compounds of the present invention can be applied to the manufacture of OLED light-emitting devices. Compared with known materials, the compounds of the present invention can be used as the main material of the light-emitting layer in the manufacture of OLED light-emitting devices. And compared with the comparative example, both the efficiency and the lifespan are greatly improved compared with the known OLED materials, especially the driving lifespan of the device is greatly improved. The organic compounds of the present invention can make the driving voltage of the device as low as 3.81V or less, the current efficiency reaches more than 7cd / A, the luminous efficiency is more than 5.88Lm / W, and the lifespan reaches more than 31h, with good comprehensive performance.

[0062] The applicant declares that the present invention illustrates the nitrogen-containing heterocyclic compound and its application through the above-mentioned embodiments, but the present invention is not limited to the above-mentioned embodiments, that is, it does not mean that the present invention must rely on the above-mentioned embodiments to be implemented. Those skilled in the art should understand that any improvement of the present invention, equivalent replacement of various raw materials of the product of the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A quinoxaline compound containing a triazine group, characterized in that: The triazine group-containing quinoxaline compound has a structure shown in Formula I: wherein R1 and R2 are the same or different and are each independently selected from any one of a C1-C4 straight chain alkyl group or a C1-C4 branched chain alkyl group, or R1 and R2 are different and one is selected from any one of a C1-C4 straight chain alkyl group or a C1-C4 branched chain alkyl group, and the other is selected from a substituted or unsubstituted C6-C18 aryl group; L is a direct bond or a phenylene group; Ar1-Ar3 are independently selected from substituted or unsubstituted C6-C30 aryl groups.

2. The triazine group-containing quinoxaline compound according to claim 1, characterized in that: The substituent in the substituted C6-C18 aryl or substituted C6-C30 aryl is selected from one or a combination of at least two of phenyl, methyl, isopropyl, isobutyl or tert-butyl; Preferably, R1 and R2 are the same or different and are each independently selected from methyl, ethyl, isopropyl, tert-butyl.

3. The triazine group-containing quinoxaline compound according to claim 1 or 2, characterized in that: R1 and R2 are different, one of which is selected from methyl, ethyl, isopropyl or tert-butyl, and the other is selected from phenyl, methyl, methylphenyl, biphenyl or naphthyl.

4. The triazine group-containing quinoxaline compound according to any one of claims 1 to 3, characterized in that: Ar1-Ar3 are independently selected from phenyl, methylphenyl, biphenyl, dimethylfluorenyl or naphthyl.

5. The triazine group-containing quinoxaline compound according to any one of claims 1 to 4, characterized in that: The triazine group-containing quinoxaline compound is any one of the following compounds:

6. An organic electroluminescent material, characterized in that: The organic electroluminescent material comprises the triazine group-containing quinoxaline compound according to any one of claims 1 to 5.

7. An electron transport material, characterized in that The electron transport material comprises the triazine group-containing quinoxaline compound according to any one of claims 1 to 5.

8. An organic electroluminescent device, characterized in that: The organic electroluminescent device comprises an anode, a cathode, and an organic thin film layer located between the anode and the cathode, wherein the organic thin film layer comprises a quinoxaline compound containing a triazine group according to any one of claims 1 to 5; Preferably, the organic thin film layer comprises any one or a combination of at least two of a hole injection layer, a hole transport layer, a light emitting layer, an electron blocking layer, an electron transport layer, a hole blocking layer or an electron injection layer; Preferably, the electron transport layer comprises the triazine group-containing quinoxaline compound according to any one of claims 1 to 5.

9. A display panel, characterized in that: The display panel comprises the organic electroluminescent device as claimed in claim 8. 10 . An electronic device comprising the display panel according to claim 9 .

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