Triazine-containing carbazole compound and application thereof

Abstract

The application provides a triazine-containing carbazole compound and application thereof, and the triazine-containing carbazole compound has a structure shown in formula I. The triazine-containing carbazole compound is obtained by designing the structure of the triazine-containing carbazole compound, has good light emitting performance, and can be used for preparing an organic electroluminescent device, especially as a green light host material in the organic electroluminescent device, so that the driving voltage of the organic electroluminescent device can be effectively reduced, and the current efficiency of the organic electroluminescent device can be improved.

Description

Technical Field

[0001] This invention belongs to the field of organic optoelectronic technology, specifically relating to a carbazole compound containing triazine and its applications. Background Technology

[0002] Organic light emission diodes (OLED) technology can be used to manufacture new display products as well as new lighting products, and is expected to replace existing liquid crystal displays and fluorescent lighting, with a very wide range of applications.

[0003] Organic Light Emitting Diode (OLED) displays are self-emissive displays. They consist of a "sandwich" structure made up of a very thin coating of organic material and a glass substrate. The entire structure includes a hole transport layer (HTL), an emissive layer (EL), and an electron transport layer (ETL). When an appropriate voltage is applied, these organic light-emitting materials emit specific light. Due to the self-emissive nature of OLEDs, they do not require a backlight, have low voltage requirements and are energy-efficient. Furthermore, OLEDs offer stable performance and excellent color display, making them promising for applications in the display and lighting fields.

[0004] Currently, although the application scope of OLED is constantly expanding and OLED display technology has gradually been industrialized, there are still shortcomings. The research and development of luminescent materials is a popular direction for solving these problems. For the field of OLED technology, it is particularly important to develop a high-performance OLED luminescent material. Through material innovation, the driving voltage of the device can be optimized, the luminous efficiency and display effect of the OLED device can be improved, and the lifespan of the OLED device can be extended. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the present invention aims to provide a triazine-containing carbazole compound and its applications. The present invention designs a triazine-containing carbazole compound structure, resulting in a triazine-containing carbazole compound with excellent properties, suitable as a green light host material in organic electroluminescent devices.

[0006] To achieve this objective, the present invention adopts the following technical solution: On one hand, the present invention provides a triazine-containing carbazole compound having the structure shown in Formula I: R1 and R2 are each independently selected from C6~C40 aryl groups; R3 and R4 are each independently selected from C6~C 40 aryl or C3~C30 heteroaryl groups; In the compound of formula I, the hydrogen atoms can be independently replaced by at least one of deuterium, F, CN, C1-C10 alkyl or C6-C20 aryl.

[0007] Preferably, the C6-C40 aryl group is selected from any one of phenyl, diphenyl, terphenyl, naphthyl, anthracene, phenanthryl, dibenzofluorenyl, pyrene, perylene, or triphenylene.

[0008] Preferably, the heteroatom in the C3~C30 heteroaryl group is an oxygen or sulfur atom; Preferably, the heteroaryl group of C3 to C30 is selected from any one of benzofuran, benzothiophene, dibenzofuran, or dibenzothiophene.

[0009] Preferably, each hydrogen atom in the compound of formula I can be independently substituted by at least one of -D, F, CN, methyl, ethyl, propyl, butyl or phenyl.

[0010] Preferably, the compound comprises any one of the following compounds: .

[0011] Preferably, the triazine-containing carbazole compound is selected from any one of compounds 1-20: .

[0012] This invention lists some specific structural forms of the triazine-containing carbazole compounds, but the triazine-containing carbazole compounds of this invention are not limited to these listed chemical structures. Any structure based on the structure shown in Formula I, where R1, R2, R3, and R4 satisfy the above-mentioned limiting conditions should be included.

[0013] In a second aspect, the present invention provides an organic electroluminescent device, the organic electroluminescent device comprising a carbazole compound containing triazine as described in the first aspect.

[0014] Preferably, the organic electroluminescent device includes a first electrode, a second electrode, and an organic layer disposed between the first electrode and the second electrode; the material of the organic layer includes a carbazole compound containing triazine as described in the first aspect.

[0015] Preferably, the organic layer includes a light-emitting layer; the material of the light-emitting layer includes a carbazole compound containing triazine as described in the first aspect.

[0016] Thirdly, the present invention provides a display device comprising the organic electroluminescent device as described in the second aspect.

[0017] Compared with the prior art, the present invention has the following beneficial effects: This invention designs the structure of triazine-containing carbazole compounds to obtain triazine-containing carbazole compounds with good luminescence properties. These compounds can be used to prepare organic electroluminescent devices, especially as the green light host material in organic electroluminescent devices. They can effectively reduce the driving voltage of organic electroluminescent devices and improve the current efficiency of organic electroluminescent devices. Detailed Implementation

[0018] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention in any way.

[0019] Synthesis Example 1 This embodiment provides a method for synthesizing compound 1, as follows: Synthesis of Intermediate I 0.1 mol of 8-bromo-5-phenyl-11H-benzo[a]carbazole, 0.11 mol of (4,6-diphenyl-1,3,5-triazin-2-yl)boric acid, 0.15 mol of potassium carbonate, 0.003 mol of tetra(triphenylphosphine)palladium, 300 mL of toluene, 100 mL of ethanol, and 100 mL of water were added to a reaction flask. The mixture was heated to reflux under nitrogen protection and reacted for 5 h. After the reaction was completed, the reaction solution was allowed to cool naturally to room temperature. The mixture was then separated, and the aqueous phase was extracted with 200 mL of toluene. The organic phases were combined, dried over anhydrous magnesium sulfate, and filtered to remove the anhydrous magnesium sulfate. The filtrate was passed through a silica gel column to remove the catalyst. The column chromatography solution was concentrated and recrystallized from ethanol and toluene to obtain intermediate I.

[0020] The mass spectrometry data of intermediate I were tested, and the mass spectrometry m / z was measured to be 524.20.

[0021] Synthesis of Compound 1 0.1 mol of intermediate I, 0.11 mol of iodobenzene, 0.003 mol of tris(dibenzylacetone)dipalladium, 0.006 mol of (2-dicyclohexylphosphine-2',4',6'-triisopropylbiphenyl), 0.12 mol of sodium tert-butoxide, and 300 ml of xylene were added to a reaction flask. Under nitrogen protection, the mixture was heated to reflux and reacted for 12 h. After the reaction was completed, the mixture was cooled to room temperature and 500 ml of n-heptane and 200 ml of distilled water were added. The mixture was stirred for 30 min and filtered. The filter cake was then added to 200 ml of distilled water and stirred for 30 min. The mixture was then filtered again and 200 ml of ethanol was added to the filter cake and stirred for 30 min. The mixture was then filtered again and the filter cake was dried under vacuum to obtain compound 1.

[0022] The mass spectrometry data of compound 1 were tested, and the mass spectrum m / z was measured to be 600.23.

[0023] Synthesis Example 2 This embodiment provides a method for synthesizing compound 2, as follows: Synthesis of Intermediate II The specific preparation method of intermediate II is the same as that of intermediate I in synthesis example 1. The only difference between intermediate II and intermediate I is that intermediate 8-bromo-5-phenyl-11H-benzo[a]carbazole is replaced with 8-bromo-5-chloro-11H-benzo[a]carbazole to obtain intermediate II.

[0024] The mass spectrometry data of intermediate II were tested, and the mass spectrometry m / z was measured to be 482.13.

[0025] Synthesis of Intermediate III 0.1 mol of intermediate II, 0.11 mol of 2-naphtholic boric acid, 0.003 mol of Pd(PPh3)4, and 0.15 mol of potassium carbonate were dissolved in 500 mL of THF and 250 mL of distilled water. The mixture was heated to reflux under nitrogen protection for 6 hours. After the reaction was complete, the mixture was filtered, and the filter cake was added to 400 mL of toluene and heated until dissolved. The solution was then passed through a silica gel column. The column chromatography solution was concentrated to 100 mL, and 400 mL of ethanol was added. The mixture was stirred at room temperature for 1 hour, filtered, and the filter cake was dried under vacuum to obtain intermediate III.

[0026] The mass spectrometry data of intermediate III were tested, and the mass spectrometry m / z was measured to be 574.22.

[0027] Synthesis of Compound 2 The specific preparation method of compound 2 is the same as that of compound 1 in synthesis example 1. The only difference between compound 2 and compound 1 is that intermediate I is replaced with intermediate III to obtain compound 2.

[0028] The mass spectrometry data of compound 2 were tested, and the mass spectrum m / z was measured to be 650.25.

[0029] Synthesis Example 3 This embodiment provides a method for synthesizing compound 3, as follows: Synthesis of intermediate IV The specific preparation method of intermediate IV is the same as that of intermediate III in synthesis example 2. The only difference between intermediate IV and intermediate III is that 2-naphthoboronic acid is replaced with dibenzo[b,d]furan-4-ylboronic acid to obtain intermediate IV.

[0030] The mass spectrometry data of intermediate IV were tested, and the mass spectrometry m / z was measured to be 614.21.

[0031] Synthesis of Compound 3 The specific preparation method of compound 3 is the same as that of compound 1 in Synthesis Example 1. The only difference between compound 3 and compound 1 is that intermediate I is replaced with intermediate IV and iodobenzene is replaced with 1-bromonaphthalene to obtain compound 3.

[0032] The mass spectrometry data of compound 4 were tested, and the mass spectrum m / z was measured to be 740.26.

[0033] Synthesis Example 4 This embodiment provides a method for synthesizing compound 4, as follows: Synthesis of intermediate V The specific preparation method of intermediate V is the same as that of intermediate II in synthesis example 2. The only difference between intermediate V and intermediate II is that (4,6-diphenyl-1,3,5-triazin-2-yl)boronic acid is replaced with (4-(naphthyl-2-yl)-6-phenyl-1,3,5-triazin-2-yl)boronic acid to obtain intermediate V.

[0034] The mass spectrometry data of intermediate V were tested, and the mass spectrometry m / z was measured to be 532.15.

[0035] Synthesis of intermediate VI The specific preparation method of intermediate VI is the same as that of intermediate III in synthesis example 2. The only difference between intermediate VI and intermediate III is that 2-naphthoboronic acid is replaced with dibenzothiophene-3-ylboronic acid and intermediate II is replaced with intermediate V to obtain intermediate VI.

[0036] The mass spectrometry data of intermediate VI were tested, and the mass spectrometry m / z was measured to be 680.20.

[0037] Synthesis of Compound 4 The specific preparation method of compound 4 is the same as that of compound 2 in synthesis example 2. The only difference between compound 4 and compound 2 is that intermediate I is replaced with intermediate VI and iodobenzene is replaced with 2-bromonaphthalene to obtain compound 4.

[0038] The mass spectrometry data of compound 4 were tested, and the mass spectrometry m / z was measured to be 806.25.

[0039] As shown in Table 1, the raw materials for the preparation of compounds 5-10 and the mass spectrometry detection data are shown in Table 1.

[0040] Table 1 Other compounds for which specific synthesis steps are not listed can be prepared using common knowledge in the art, in conjunction with the above examples.

[0041] The specific structures of the compounds used in the following device embodiments and device comparative examples are shown below: Device Application Example 1 Application Example 1 of this device provides an organic electroluminescent device, in which the compound provided by this invention is selected as the green light host material in the organic electroluminescent device.

[0042] The structure of the organic electroluminescent device is as follows: ITO / NPB (20nm) / green light host material (35nm): Ir(ppy)3 [10%] / TPBI (10nm) / Alq3 (15nm) / LiF (0.5nm) / Al (150nm). Here, "Ir(ppy)3 [10%]" refers to the doping ratio of the green dye, i.e., the volume ratio of the green light host material to Ir(ppy)3 is 90:10.

[0043] The fabrication process of the organic electroluminescent device is as follows: (1) The glass plate coated with ITO transparent conductive layer was ultrasonically treated in commercial cleaning agent, rinsed in deionized water, ultrasonically degreased in acetone: ethanol mixed solvent, baked in a clean environment until the moisture was completely removed, cleaned with ultraviolet light and ozone, and bombarded with low-energy cation beam. (2) Place the glass substrate with the anode into the vacuum chamber and evacuate to 1×10⁻⁶. -5 ~9×10 -4 Pa, a hole transport layer NPB is vacuum-deposited on the above-mentioned anodic layer film at a deposition rate of 0.1 nm / s and a film thickness of 20 nm. (3) A green light host material and dye Ir(ppy)3 were vacuum-deposited on the hole transport layer as the light-emitting layer of the organic electroluminescent device. The deposition rate was 0.1 nm / s and the total deposition film thickness was 35 nm. (4) Electron transport layers TPBI and Alq3 are vacuum-deposited sequentially on the light-emitting layer at a deposition rate of 0.1 nm / s and a film thickness of 10 nm and 15 nm, respectively. (5) 0.5 nm of LiF was vacuum-deposited on the electron transport layer, and 150 nm of Al was used as the electron injection layer and cathode.

[0044] Device Examples 2-10 Device Examples 2-10 each provide an organic electroluminescent device, which differs from Device Example 1 only in that the green light host material is different (see Table 2 below), while other conditions are the same as Device Example 1.

[0045] Device Comparison Examples 1-3 Comparative Examples 1-3 each provide an organic electroluminescent device, which differs from Device Example 1 only in that the green light host material is different (see Table 2 below), while other conditions are the same as Device Example 1.

[0046] Performance testing: The brightness, driving voltage, current efficiency, and lifetime test LT90 of the organic electroluminescent devices provided above were tested. The lifetime test LT90 refers to maintaining a constant current density (1000 cd / m²) at room temperature (25-27°C) while retaining the initial brightness. 2 The time required for the brightness to decrease to 90% of the initial brightness. In the table below, the driving voltage, current efficiency, and LT90 lifetime are all relative values ​​(based on the test data of Device Comparison 1). The test results are detailed in Table 2 below.

[0047] Table 2 As shown in Table 2, this invention has obtained triazine-containing carbazole compounds through molecular design. The triazine-containing carbazole compounds provided by this invention can be used as the green light host material for OLED light-emitting devices, enabling the OLED light-emitting devices to have lower driving voltage, higher current efficiency, and longer lifetime.

[0048] The applicant declares that this invention illustrates the triazine-containing carbazole compounds and their applications through the above embodiments, but this invention is not limited to the above embodiments, that is, it does not mean that this invention must rely on the above embodiments to be implemented. Those skilled in the art should understand that any improvements to this invention, equivalent substitutions of the raw materials of the product of this invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of this invention.

Claims

1. A carbazole compound containing triazine, characterized in that, The triazine-containing carbazole compound has the structure shown in Formula I: R1 and R2 are each independently selected from any one of phenyl, diphenyl, triphenyl, naphthyl, anthraceneyl, phenanthrene or triphenylene; R3 and R4 are each independently selected from any one of phenyl, diphenyl, triphenyl, naphthyl, anthraquinone, phenanthrene, dibenzofluorenyl, triphenylene, benzofuran, benzothiophene, dibenzofuran or dibenzothiophene; In the compound of formula I, the hydrogen atoms can be independently replaced by at least one of deuterium, F, CN, C1-C10 alkyl or phenyl.

2. The triazine-containing carbazole compound according to claim 1, characterized in that, In the compound of Formula I, each hydrogen atom can be independently substituted by at least one of -D, F, CN, methyl, ethyl, propyl, butyl, or phenyl.

3. A carbazole compound containing triazine, characterized in that, The compound includes any one of the following compounds: 。 4. The triazine-containing carbazole compound according to claim 3, characterized in that, The triazine-containing carbazole compound is selected from any one of compounds 1-20: 。 5. An organic electroluminescent device, characterized in that, The organic electroluminescent device comprises a carbazole compound containing triazine as described in any one of claims 1-4.

6. The organic electroluminescent device according to claim 5, characterized in that, The organic electroluminescent device includes a first electrode, a second electrode, and an organic layer disposed between the first electrode and the second electrode; the material of the organic layer includes a carbazole compound containing triazine as described in any one of claims 1-4.

7. The organic electroluminescent device according to claim 6, characterized in that The organic layer includes a light-emitting layer; the material of the light-emitting layer includes a carbazole compound containing triazine as described in any one of claims 1-4.

8. A display device, characterized by comprising: The display device includes an organic electroluminescent device as described in any one of claims 5-7.

Images