Triazine compound, organic electroluminescent device and display device

Abstract

The invention provides a triazine compound, an organic electroluminescent device and a display device, and relates to the technical field of organic photoelectricity. The triazine compound has a structure as shown in a formula I in the specification. The triazine compound provided by the invention has good luminescence performance, can be used for preparing the organic electroluminescent device, and can effectively improve the current efficiency of the organic electroluminescent device and prolong the service life of the organic electroluminescent device especially as an electron transport layer material in the organic electroluminescent device.

Description

Technical Field

[0001] The present invention relates to the field of organic photoelectric technology, and in particular to a triazine compound, an organic electroluminescent device and a display device. Background Art

[0002] Organic Light-Emitting Diode (OLED) has the advantages of light weight, small size, wide viewing angle, fast response, wide operating temperature range, low energy consumption, high efficiency, good color purity, high clarity, and good flexibility. It can meet consumers' new demands for display technology and has good application prospects in the fields of lighting and display.

[0003] An organic electroluminescent element is a self-luminous element that utilizes the following principle: by applying an electric field, the fluorescent material emits light by utilizing the recombination energy of holes injected from the anode and electrons injected from the cathode. It has the following structure: an anode, a cathode, and an organic material layer between the two. In order to improve the efficiency and stability of the organic electroluminescent element, the organic material layer generally includes multiple layers with different materials, such as a hole injection layer HIL, a hole transport layer HTL, a light-emitting layer, an electron transport layer ETL, and an electron injection layer EIL. In such an organic light-emitting element, when a voltage is applied between the anode and the cathode, holes from the anode and electrons from the cathode are injected into the organic material layer, and the generated excitons generate light with a specific wavelength when they migrate to the ground state. The hole transport layer can change the hole transfer efficiency, light-emitting efficiency, life, etc. from holes to the light-emitting layer.

[0004] At present, the research on organic electroluminescent materials has been widely carried out in academia and industry. Among them, luminescent materials are an important component of organic electroluminescent devices. The transmission performance and luminous efficiency of luminescent materials restrict the industrialization of luminescent devices. Therefore, designing and finding a compound as a new OLED material to overcome its shortcomings in practical applications is the focus of OLED material research and the future research and development trend. Summary of the invention

[0005] 1. Technical issues to be solved

[0006] In view of the shortcomings of the prior art, the present invention aims to provide a triazine compound, an organic electroluminescent device, and a display device. The present invention is designed through the structure of the triazine compound, and the obtained triazine compound has excellent performance and is suitable for use as an electron transport material in an organic electroluminescent device.

[0007] (II) Technical solution

[0008] To achieve the above objectives, the present invention is implemented through the following technical solutions:

[0009] In a first aspect, the present invention provides a triazine compound having a structure as shown in the following formula I:

[0010]

[0011] Wherein, R1, R2 and R3 are each independently selected from C1 to C 12 Alkyl, C6~C 30 Aryl, C3~C 30 Any one or a combination of two of the heteroaryl groups;

[0012] C1~C 12 The alkyl group is selected from any one of methyl, ethyl, propyl, isopropyl, butyl, tert-butyl, pentyl, tert-pentyl, n-hexyl, cyclohexyl, methoxy and the like.

[0013] C6~C 30 The aryl group is selected from any one of phenyl, biphenyl, terphenyl, naphthyl, anthracenyl, indenyl, fluorenyl, perylenyl, phenanthrenyl, pyrenyl, fluoranthenyl and triphenylenyl.

[0014] C3~C 30 The hetero atom in the heteroaryl group is any one of oxygen, sulfur and nitrogen atoms.

[0015] C3~C 30 The aromatic hetero group is selected from one of benzofuranyl, benzothiophenyl, pyridyl, dibenzofuranyl, pyrimidinyl, dibenzothiophenyl, carbazolyl, phenyl-substituted carbazolyl, diarylideneamine, benzofuranocarbazolyl, benzofuranothiophenyl and triazine.

[0016] The following are preferred technical solutions of the present invention, but are not intended to limit the technical solutions provided by the present invention. Through the following preferred technical solutions, the objectives and beneficial effects of the present invention can be better achieved and realized.

[0017] As a preferred technical solution of the present invention, the triazine compound includes any one of the following compounds:

[0018]

[0019]

[0020] Preferably, the compound represented by formula I is selected from any one of compounds 1 to 12:

[0021]

[0022] The present invention lists some specific structural forms of the triazine compounds, but the present invention

[0023] It is noted that the triazine compounds are not limited to the listed chemical structures, and any structure based on the structure shown in Formula I where R1, R2, and R3 meet the above-mentioned limiting conditions should be included.

[0024] In a second aspect, the present invention provides an organic electroluminescent device, wherein the organic electroluminescent device comprises the triazine compound as described in the first aspect.

[0025] Preferably, the organic electroluminescent device comprises a first electrode, a second electrode and an organic layer disposed between the first electrode and the second electrode;

[0026] The material of the organic layer includes the triazine compound as described in the first aspect.

[0027] Preferably, the organic layer comprises an electron transport layer;

[0028] The material of the electron transport layer includes the triazine compound as described in the first aspect.

[0029] In a third aspect, the present invention provides a display device, comprising the organic electroluminescent device as described in the second aspect.

[0030] (III) Beneficial effects

[0031] The present invention provides a triazine compound, an organic electroluminescent device, and a display device. Compared with the prior art, the triazine compound has the following beneficial effects:

[0032] The triazine compound obtained by the present invention has good luminescent properties by designing the structure of the triazine compound, and can be used to prepare organic electroluminescent devices, especially as an electron transport layer material in the organic electroluminescent device, which can effectively improve the current efficiency of the organic electroluminescent device and increase the life of the organic electroluminescent device. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention are clearly and completely described. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0034] The present invention provides a triazine compound, an organic electroluminescent device, and a display device. The triazine compound has a structure shown in Formula I. The present invention designs the structure of a fluorene compound, wherein the structure of the compound is that fluorene is connected to a dibenzo pentacyclic ring structure through a carbon-carbon bond, and the carbon-carbon bond connection not only improves the chemical stability of the material but also avoids the exposure of the active position of the branched group, and the entire molecule is a relatively large rigid structure with a high triplet energy level (T1); and the steric hindrance is large, it is not easy to rotate, and the three-dimensional space structure is more stable, so the compound has a higher glass transition temperature and molecular thermal stability; the organic electroluminescent device prepared as an electron transport material has a lower driving voltage, a higher current efficiency and a longer life.

[0035]

[0036] In order to better understand the above technical solution, the above technical solution will be described in detail below in conjunction with specific implementation methods.

[0037] Synthesis Example 1

[0038] This embodiment provides a method for synthesizing compound 1, as described below:

[0039]

[0040] (1) Synthesis of intermediate 1-a

[0041] 2-Bromo-9-(4-chlorophenyl)-9-phenyl-9H-fluorene (100 mmol), 2-nitrobenzeneboronic acid pinacol ester (100 mmol), tetrakis(triphenylphosphine)palladium 1 mmol, potassium carbonate (120 mmol), water 50 mL, dioxane 300 mL, were added to a reaction bottle, refluxed for 4 hours under nitrogen protection, cooled after the reaction was complete, toluene was added, the liquids were separated, the organic layer was spin-dried, and the obtained solid was recrystallized from a mixed solvent of toluene and ethanol to obtain intermediate 1-a.

[0042] The mass spectrum data of intermediate 1-a was tested, and the mass spectrum m / z was measured to be 473.12.

[0043] (2) Synthesis of intermediate 1-b

[0044] The intermediate 1-a (40 mmol), phenylboric acid (40 mmol), dichlorodi-tert-butyl-(4-dimethylaminophenyl)phosphine palladium (II) (0.4 mmol), potassium carbonate (60 mmol) and 300 mL of toluene were added into a reaction flask and heated to reflux for 8 h. The reaction was monitored to be complete by TLC. After filtration with diatomaceous earth, purified water was added and washed until neutral. The organic phase was concentrated and the obtained solid was recrystallized with a mixed solvent of toluene and ethanol to obtain the intermediate 1-b.

[0045] The mass spectrum data of intermediate 1-b was tested, and the mass spectrum m / z was measured to be 515.19.

[0046] (3) Synthesis of intermediate 1-c

[0047] The intermediate 1-b (50 mmol), triphenylphosphine (100 mmol) and o-dichlorobenzene 150 mL were added to the reaction bottle, and the reaction was refluxed for 6 h under nitrogen protection. After the reaction was complete, o-dichlorobenzene was directly distilled out, and the residue was dissolved in toluene and purified by column chromatography. The solid obtained after the column liquid was dried was recrystallized with a mixed solvent of toluene and ethanol to obtain 1-c.

[0048] The mass spectrum data of intermediate 1-c was tested, and the mass spectrum m / z was measured to be 483.20.

[0049] (4) Synthesis of Compound 1

[0050] Intermediate 1-c (30 mmol), 2-bromo-4,6-diphenyl-1,3,5-triazine (30 mmol), cesium carbonate (60 mmol) and DMF (300 mL) were added to a reaction bottle and heated to reflux for 12 h. The reaction was completed after monitoring by TLC. The reaction solution was poured into water with stirring and filtered. The filter cake was washed with ethanol and recrystallized from toluene to obtain compound 1.

[0051] The mass spectrum data of compound 1 was tested and the mass spectrum m / z was measured to be 714.28.

[0052] Synthesis Example 2

[0053] This embodiment provides a method for synthesizing compound 2, as described below:

[0054]

[0055] Referring to the synthesis method of compound 1, 2-chloro-4-(2-dibenzofuranyl)-6-phenyl-1,3,5-triazine is used to replace 2-bromo-4,6-diphenyl-1,3,5-triazine in Synthesis Example 1, and compound 2 can be obtained while keeping other conditions unchanged.

[0056] The mass spectrum data of compound 2 was tested and the mass spectrum m / z was measured to be 804.29.

[0057] Synthesis Example 3

[0058] This embodiment provides a method for synthesizing compound 5, as described below:

[0059]

[0060] Referring to the synthesis method of compound 1, 2,4-di([1,1'-biphenyl]-4-yl)-6-chloro-1,3,5-triazine was used to replace 2-bromo-4,6-diphenyl-1,3,5-triazine in Synthesis Example 1, and compound 5 was obtained while keeping other conditions unchanged.

[0061] The mass spectrum data of compound 5 was tested and the mass spectrum m / z was measured to be 866.34.

[0062] Synthesis Example 4

[0063] This embodiment provides a method for synthesizing compound 6, as described below:

[0064]

[0065] Referring to the synthesis method of compound 1, 2-chloro-4-(naphtho[2,3-b]benzofuran-2-yl)-6-phenyl-1,3,5-triazine was used to replace the 2-bromo-4,6-diphenyl-1,3,5-triazine in Synthesis Example 1, and compound 6 was obtained while keeping other conditions unchanged.

[0066] The mass spectrum data of compound 6 was tested and the mass spectrum m / z was measured to be 854.30.

[0067] Synthesis Example 5

[0068] This embodiment provides a method for synthesizing compound 7, as described below:

[0069]

[0070] (1) Synthesis of intermediate 7-a

[0071] 2-Bromo-9-(4-chlorophenyl)-9-phenyl-9H-fluorene (100 mmol), 2-nitrobenzeneboronic acid pinacol ester (100 mmol), tetrakis(triphenylphosphine)palladium 1 mmol, potassium carbonate (120 mmol), water 50 mL, dioxane 300 mL, were added to a reaction bottle, refluxed for 4 hours under nitrogen protection, cooled after the reaction was complete, toluene was added, the liquids were separated, the organic layer was spin-dried, and the obtained solid was recrystallized from a mixed solvent of toluene and ethanol to obtain intermediate 1-a.

[0072] The mass spectrum data of intermediate 7-a was tested, and the mass spectrum m / z was measured to be 473.12.

[0073] (2) Synthesis of intermediate 7-b

[0074] The intermediate 7-a (40 mmol), 4-biphenylboronic acid (40 mmol), dichlorodi-tert-butyl-(4-dimethylaminophenyl)phosphine palladium (II) (0.4 mmol), potassium carbonate (60 mmol) and 300 mL of toluene were added into a reaction flask and heated to reflux for 8 h. The reaction was monitored to be complete by TLC. After filtration with diatomaceous earth, purified water was added and washed until neutral. The organic phase was concentrated and the obtained solid was recrystallized with a mixed solvent of toluene and ethanol to obtain the intermediate 7-b.

[0075] The mass spectrum data of intermediate 7-b was tested and the mass spectrum m / z was measured to be 591.22.

[0076] (3) Synthesis of intermediate 7-c

[0077] The intermediate 7-b (50 mmol), triphenylphosphine (100 mmol) and o-dichlorobenzene 150 mL were added to the reaction bottle, and the reaction was refluxed for 6 h under nitrogen protection. After the reaction was complete, o-dichlorobenzene was directly distilled out, and the residue was dissolved in toluene and purified by column chromatography. The solid obtained after the column liquid was dried was recrystallized with a mixed solvent of toluene and ethanol to obtain 7-c.

[0078] The mass spectrum data of intermediate 7-c was tested, and the mass spectrum m / z was measured to be 559.23.

[0079] (4) Synthesis of Compound 7

[0080] The intermediate 7-c (30 mmol), 2,4-di([1,1'-biphenyl]-4-yl)-6-chloro-1,3,5-triazine (30 mmol), cesium carbonate (60 mmol) and DMF (300 mL) were added to a reaction bottle and heated to reflux for 12 h. The reaction was completed after monitoring by TLC. The reaction solution was poured into water with stirring and filtered. The filter cake was washed with ethanol and recrystallized from toluene to obtain compound 7.

[0081] The mass spectrum data of compound 7 was tested and the mass spectrum m / z was measured to be 942.37.

[0082] Synthesis Example 6

[0083] This embodiment provides a method for synthesizing compound 9, as described below:

[0084]

[0085] Referring to the synthesis method of compound 1, 2-chloro-4-(naphthalen-2-yl)-6-phenyl-1,3,5-triazine was used to replace 2-bromo-4,6-diphenyl-1,3,5-triazine in Synthesis Example 1, and compound 9 was obtained while keeping other conditions unchanged.

[0086] The mass spectrum data of compound 9 was tested, and the mass spectrum m / z was measured to be 764.29.

[0087] Synthesis Example 7

[0088] This embodiment provides a method for synthesizing compound 10, as described below:

[0089]

[0090] Referring to the synthesis method of compound 1, 9-[4-(4-chloro-6-phenyl-1,3,5-triazine-2-yl)phenyl]-9H-carbazole was used to replace the 2-bromo-4,6-diphenyl-1,3,5-triazine in Synthesis Example 1, and compound 10 was obtained while keeping other conditions unchanged.

[0091] The mass spectrum data of compound 10 was tested, and the mass spectrum m / z was measured to be 879.34.

[0092] Other compounds for which specific synthesis steps are not listed can be prepared by common knowledge in the art in combination with the above embodiments.

[0093] The material structure used in the device is as follows:

[0094]

[0095] Device Example 1

[0096] The device embodiment uses the compound of the present application as the electron transport material in the organic electroluminescent device.

[0097] The structure of the organic electroluminescent device is: ITO / NPB (40nm) / EM1 (30nm) / electron transport material (30nm) / LiF (0.5nm) / Al (150nm).

[0098] The preparation process of organic electroluminescent device is as follows:

[0099] The glass substrate coated with an ITO transparent conductive layer (as an anode) is ultrasonically treated in a cleaning agent, then rinsed in deionized water, ultrasonically degreased in a mixed solvent of acetone and ethanol, baked in a clean environment until the water is completely removed, cleaned with ultraviolet light and ozone, and bombarded with a low-energy cation beam to improve the properties of the surface and enhance the binding ability with the hole injection layer;

[0100] The glass substrate was placed in a vacuum chamber and evacuated to 1×10 -6 ~9×10 -5 Pa, vacuum evaporate NPB on the anode as a hole transport layer, the evaporation rate is 0.1nm / s, and the evaporation film thickness is 40nm;

[0101] Vacuum evaporate EM1 on the hole transport layer as the organic light-emitting layer of the device, with an evaporation rate of 0.1 nm / s and a total evaporation film thickness of 30 nm;

[0102] A comparative compound and a compound of the present invention are vacuum-deposited on the organic light-emitting layer as an electron transport layer of an organic electroluminescent device; the evaporation rate is 0.1 nm / s, and the total evaporation film thickness is 30 nm;

[0103] 0.5 nm of LiF and 150 nm of Al were vacuum-deposited on the electron transport layer to serve as an electron injection layer and a cathode.

[0104] The brightness, driving voltage, current efficiency and life test LT90 of the prepared organic electroluminescent device were measured.

[0105] Device Examples 2-7

[0106] Device Examples 2-7 respectively provide an organic electroluminescent device, which differs from Device Example 1 only in that the electron transport material is different (see Table 1 for details), and other conditions are the same as those of Device Example 1.

[0107] Device Comparison Examples 1 and 2

[0108] The device comparative examples 1 and 2 of the present invention respectively provide an organic electroluminescent device, which differs from the device embodiment 1 only in that the electron transport material is different (see Table 1 for details), and other conditions are the same as those of the device embodiment 1.

[0109] Performance Testing

[0110] Test method: Test the driving voltage, current efficiency and life LT90 of the OLED devices provided above; LT90 refers to the time required for the brightness to drop to 90% of the original brightness while maintaining the current density at the initial brightness of 1000nit. The test items include the brightness, driving voltage and current efficiency of the organic electroluminescent device. The driving voltage, current efficiency and LT90 data are all based on a brightness of 1000cd / m 2 The relative value of the device performance test results is shown in Table 1.

[0111] Table 1 Electron transport materials used in various device embodiments and device comparative examples and device performance tests

[0112]

[0113] It can be seen from the contents of Table 1 that the present invention obtains triazine compounds through molecular design. The triazine compounds provided by the present invention can be used as electron transport materials for OLED light-emitting devices, so that the OLED light-emitting devices have lower driving voltage, higher current efficiency and longer life.

[0114] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0115] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

[0116] The present invention illustrates the detailed process flow of the present invention through the above-mentioned embodiments, but the present invention is not limited to the above-mentioned detailed process flow, that is, it does not mean that the present invention must rely on the above-mentioned detailed process flow 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 triazine compound, characterized in that: The triazine compound has a structure as shown in the following formula I: Wherein, R1, R2 and R3 are each independently selected from C1 to C 12 Alkyl, C6~C 30 Aryl, C3~C 30 Any one or a combination of two of the heteroaryl groups.

2. The triazine compound according to claim 1, characterized in that At least one of the following conditions is met: C1~C 12 The alkyl group is selected from any one of methyl, ethyl, propyl, isopropyl, butyl, tert-butyl, pentyl, tert-pentyl, n-hexyl, cyclohexyl and methoxy; C6~C 30 The aryl group is selected from any one of phenyl, biphenyl, terphenyl, naphthyl, anthracenyl, indenyl, fluorenyl, perylenyl, phenanthrenyl, pyrenyl, fluoranthenyl and triphenylenyl.

3. The triazine compound according to claim 1, characterized in that C3~C 30 The heteroatom in the aromatic hetero group is selected from any one of oxygen, sulfur and nitrogen atoms.

4. The triazine compound according to claim 1, characterized in that C3~C 30 The aromatic hetero group is selected from any one of benzofuranyl, benzothiophenyl, pyridyl, dibenzofuranyl, pyrimidinyl, dibenzothiophenyl, carbazolyl, phenyl-substituted carbazolyl, diarylideneamine, benzofuranocarbazolyl, benzofuranothiophenyl and triazine.

5. The triazine compound according to claim 1, characterized in that The triazine compound includes any one of the following compounds:

6. The triazine compound according to claim 1, characterized in that The triazine compound is selected from any one of compounds 1 to 12:

7. An organic electroluminescent device, characterized in that: The organic electroluminescent device comprises the triazine compound according to any one of claims 1 to 6.

8. The organic electroluminescent device according to claim 7, characterized in that: The organic electroluminescent device comprises 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 triazine compounds.

9. The organic electroluminescent device according to claim 8, characterized in that: The organic layer includes an electron transport layer; The material of the electron transport layer includes triazine compounds.

10. A display device, characterized in that: The display device comprises the organic electroluminescent device according to any one of claims 7 to 9.

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