Triazine compounds, organic electroluminescent device, display apparatus

Abstract

The application provides a triazine compound, an organic electroluminescent device and a display device, and relates to the technical field of organic optoelectronics.The triazine compound has the following structure shown in formula I.The triazine compound has good luminescent performance, and can be used for preparing an organic electroluminescent device, especially as an electron transport layer material in the organic electroluminescent device, so that the current efficiency of the organic electroluminescent device can be effectively improved, and the service life of the organic electroluminescent device can be improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of organic optoelectronics, in particular to a triazine compound, an organic electroluminescent device and a display device. BACKGROUND

[0002] Organic light emitting diode (OLED) has the advantages of light weight, small size, wide viewing angle, fast response, wide temperature range, low energy consumption, high efficiency, good color purity, high definition, good flexibility, etc., which can meet the new needs of consumers for display technology, and has good application prospect in the fields of lighting and display.

[0003] An organic electroluminescent element is a self-luminous element that utilizes the principle of making a fluorescent substance emit light by the recombination energy of holes injected from an anode and electrons injected from a cathode by applying an electric field. 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 usually 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 resulting excitons produce light of a specific wavelength when they migrate to the ground state. The hole transport layer can change the hole transport efficiency of the holes to the light emitting layer, the light emitting efficiency, the lifetime, etc.

[0004] At present, the research on organic electroluminescent materials has been widely carried out in academia and industry. The light emitting material is an important part of the organic electroluminescent device, and the transmission performance and light emitting efficiency of the light emitting material restrict the industrialization of the light emitting device. Therefore, designing and finding a compound as a new material for OLED to overcome the deficiencies in the actual application process is the focus and future research and development trend of OLED material research work. SUMMARY

[0005] (I) Technical problems to be solved

[0006] In view of the deficiencies of the prior art, the purpose of the present application is to provide a triazine compound, an organic electroluminescent device and a display device. The triazine compound obtained by designing the structure of the triazine compound has excellent performance and is suitable for use as an electron transport material in an organic electroluminescent device.

[0007] (II) Technical solutions

[0008] In order to achieve the above purpose, the present application is realized by the following technical solutions:

[0009] In a first aspect, the present application provides a triazine compound having the following formula I:

[0010]

[0011] wherein R1, R2 and R3 are each independently selected from any one of or a combination of C1-C 12 alkyl, C6-C 30 aryl, C3-C 30 heteroaryl;

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

[0013] said C6-C 30 aryl is selected from any one of phenyl, biphenyl, terphenyl, naphthyl, anthryl, indenyl, fluorenyl, perylenyl, phenanthryl, pyrenyl, fluoranthenyl, or triphenylenyl, and the like.

[0014] said C3-C 30 heteroaryl has a heteroatom selected from any one of oxygen, sulfur, and nitrogen.

[0015] said C3-C 30 arylheteroaryl is selected from any one of benzofuranyl, benzothiophenyl, pyridyl, dibenzofuranyl, pyrimidyl, dibenzothiophenyl, carbazolyl, phenyl-substituted carbazolyl, diarylamine, benzofuranocarbazolyl, benzofuranothiophenyl, triazinyl.

[0016] The following are preferred technical solutions of the present application, but not as a limitation on the technical solutions provided by the present application, through the following preferred technical solutions, the purpose and beneficial effects of the present application can be better achieved and realized.

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

[0018]

[0019]

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

[0021]

[0022] The present application lists some specific structural forms of the triazine compound, but the present application is not limited to the specific structural forms listed in the present application.

[0023] The triazine compounds are not limited to the chemical structures listed, and any structure based on the structure shown in Formula I, and R1, R2, and R3 satisfying the above defined conditions should be included.

[0024] In a second aspect, the present application provides an organic electroluminescent device comprising the triazine compound according to 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 comprises the triazine compound according to the first aspect.

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

[0028] The material of the electron transport layer comprises the triazine compound according to the first aspect.

[0029] In a third aspect, the present application provides a display device comprising the organic electroluminescent device according to the second aspect.

[0030] (III) Advantages

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

[0032] The triazine compound obtained by designing the structure of the triazine compound has good luminescent performance, and can be used to prepare an organic electroluminescent device, 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 prolong the service life of the organic electroluminescent device. DETAILED DESCRIPTION

[0033] In order to make the objectives, technical solutions, and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application are described clearly and completely. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0034] The application provides a triazine compound, an organic electroluminescent device and a display device. The triazine compound has a structure shown in formula I. The application designs the structure of a fluorene compound, the structure of the compound is that the fluorene is connected with a dibenzo five-membered ring through a carbon-carbon bond, the carbon-carbon bond connection improves the chemical stability of the material, avoids the exposure of the active position of the branched group, and the whole molecule is a larger rigid structure, has a high triplet energy level (T1), and has a large steric hindrance and is not easy to rotate, and the spatial structure is more stable, so that the compound has a high glass transition temperature and a high molecular thermal stability; the organic electroluminescent device prepared by using the compound as an electron transport material has a low driving voltage, a high current efficiency and a long service life.

[0035]

[0036] In order to better understand the above technical solutions, the above technical solutions will be described in detail in combination with specific embodiments.

[0037] Synthesis example 1

[0038] The embodiment provides a synthesis method of the compound 1, as follows:

[0039]

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

[0041] 2-bromo-9-(4-chlorophenyl)-9-phenyl-9H-fluorene (100 mmol), 2-nitrophenylboronic 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, and refluxed under nitrogen protection for 4 h. After the reaction was completed, the temperature was lowered, toluene was added, and the organic layer was dried by spinning to obtain the intermediate 1-a which was recrystallized with a toluene and ethanol mixed solvent.

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

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

[0044] The intermediate 1-a (40 mmol), phenylboronic acid (40 mmol), dichloro-di-tert-butyl-(4-dimethylaminophenyl) palladium (II) (0.4 mmol), potassium carbonate (60 mmol), toluene 300 mL were added to a reaction bottle and heated to reflux for 8 h. The reaction was monitored by TLC, and after filtration with diatomite, pure water was added for neutralization. The organic phase was concentrated, and the obtained solid was recrystallized with a toluene and ethanol mixed solvent to obtain the intermediate 1-b.

[0045] The mass spectrum data of the intermediate 1-b was tested, and the mass spectrum m / z was 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 a reaction bottle, and refluxed under nitrogen protection for 6 h. After the reaction was completed, o-dichlorobenzene was directly distilled off, the residue was dissolved with toluene, and column chromatography purification was performed. The obtained solid after rotary evaporation of the column chromatography liquid was recrystallized with a toluene and ethanol mixed solvent to obtain 1-c.

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

[0049] (4) Synthesis of compound 1

[0050] The 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, heated to reflux, and reacted for 12 h. TLC was used to monitor the completion of the reaction. The reaction liquid was poured into water and stirred, filtered, and the filter cake was washed with ethanol and recrystallized with toluene to obtain compound 1.

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

[0052] Synthesis Example 2

[0053] This example provides a synthesis method of compound 2, as follows:

[0054]

[0055] Referring to the synthesis method of compound 1, 2-chloro-4-(2-dibenzofuranyl)-6-phenyl-1,3,5-triazine was used to replace 2-bromo-4,6-diphenyl-1,3,5-triazine in synthesis example 1, and other conditions were unchanged, and compound 2 could be obtained.

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

[0057] Synthesis Example 3

[0058] This example provides a synthesis method of compound 5, as follows:

[0059]

[0060] Referring to the synthesis method of compound 1, 2, 4-bis ([1, 1'-biphenyl]-4-yl)-6-chloro-1, 3, 5-triazine is used to replace 2-bromo-4, 6-diphenyl-1, 3, 5-triazine in synthesis example 1, and other conditions remain unchanged to obtain compound 5.

[0061] The mass spectrometry data of compound 5 is tested, and the mass spectrometry m / z is 866.34.

[0062] Synthesis example 4

[0063] This example provides a synthesis method of compound 6, which is as follows:

[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 is used to replace 2-bromo-4, 6-diphenyl-1, 3, 5-triazine in synthesis example 1, and other conditions remain unchanged to obtain compound 6.

[0066] The mass spectrometry data of compound 6 is tested, and the mass spectrometry m / z is 854.30.

[0067] Synthesis example 5

[0068] This example provides a synthesis method of compound 7, which is as follows:

[0069]

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

[0071] 2-bromo-9-(4-chlorophenyl)-9-phenyl-9H-fluorene (100 mmol), 2-nitrophenylboronic acid pinacol ester (100 mmol), tetrakis (triphenylphosphine) palladium 1 mmol, potassium carbonate (120 mmol), water 50 mL, dioxane 300 mL, are added to the reaction bottle, and refluxed under nitrogen protection for 4 h. After the reaction is completed, the temperature is lowered, toluene is added, and the liquid is separated. The organic layer is rotary dried, and the obtained solid is recrystallized with a mixture solvent of toluene and ethanol to obtain intermediate 1-a.

[0072] The mass spectrometry data of intermediate 7-a is tested, and the mass spectrometry m / z is 473.12.

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

[0074] Into a reaction flask was placed intermediate 7-a (40 mmol), 4-biphenylboronic acid (40 mmol), dichlorobis-(4-dimethylaminophenyl) palladium (II) (0.4 mmol), potassium carbonate (60 mmol), toluene 300 mL, heated to reflux for 8 h, TLC monitored the reaction was complete, filtered through celite, then added purified water to neutral, the organic phase was concentrated, the obtained solid was recrystallized with toluene and ethanol to obtain intermediate 7-b.

[0075] The mass spectrometry data of intermediate 7-b was tested, and the mass spectrometry m / z was 591.22.

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

[0077] Into a reaction flask was placed intermediate 7-b (50 mmol), triphenylphosphine (100 mmol), o-dichlorobenzene 150 mL, refluxed for 6 h under nitrogen protection, the reaction was complete, o-dichlorobenzene was distilled off directly, the residue was dissolved with toluene, purified by column chromatography, and the obtained solid was recrystallized with toluene and ethanol to obtain 7-c.

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

[0079] (4) Synthesis of compound 7

[0080] Into a reaction flask was placed 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), DMF (300 mL), heated to reflux for 12 h, TLC monitored the reaction was complete, the reaction liquid was poured into water, stirred, filtered, the filter cake was washed with ethanol, and recrystallized with toluene to obtain compound 7.

[0081] The mass spectrometry data of compound 7 was tested, and the mass spectrometry m / z was 942.37.

[0082] Synthesis Example 6

[0083] This example provides a synthesis method of compound 9, as follows:

[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 other conditions were unchanged, and compound 9 could be obtained.

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

[0087] Synthesis Example 7

[0088] This example provides a method for synthesizing compound 10, which is as follows:

[0089]

[0090] Referring to the synthesis method of compound 1, compound 10 can be obtained by replacing 2-bromo-4,6-diphenyl-1,3,5-triazine in Synthesis Example 1 with 9-[4-(4-chloro-6-phenyl-1,3,5-triazin-2-yl)phenyl]-9H-carbazole, and other conditions remain unchanged.

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

[0092] Other compounds not specifically listed in the synthesis steps can be prepared by common knowledge in the art, combined with the above examples.

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

[0094]

[0095] Device Example 1

[0096] This device example selects the compound of the present application as an electron transport material in an organic electroluminescent device.

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

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

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

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

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

[0102] Vacuum evaporate the comparative compound and the compound of the present application as electron transport layer of the organic electroluminescent device on the organic light-emitting layer, respectively; the evaporation rate is 0.1 nm / s, and the total evaporation film thickness is 30 nm;

[0103] Vacuum evaporate 0.5 nm of LiF and 150 nm of Al as electron injection layer and cathode on the electron transport layer.

[0104] The luminance, driving voltage, current efficiency and lifetime test LT90 of the prepared organic electroluminescent device are measured.

[0105] Device examples 2-7

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

[0107] Device comparative examples 1 and 2

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

[0109] Performance test

[0110] Test method: test the driving voltage, current efficiency and lifetime LT90 of the OLED device provided above; wherein LT90 refers to the time required for the luminance to drop to 90% of the original luminance while keeping the current density unchanged at the initial luminance of 1000 nit, and the test items include the luminance, driving voltage, current efficiency of the organic electroluminescent device, and the driving voltage and current efficiency, LT90 data are all relative values (based on the device comparative example 1) when the luminance is 1000 cd / m 2 The performance test results of the organic electroluminescent device are shown in Table 1.

[0111] Table 1: electron transport materials used in each device example and device comparative example and device performance test

[0112]

[0113] From the content of Table 1, it can be seen that the triazine compound is obtained by molecular design. The triazine compound provided by the present application can be used as an electron transport material of an OLED light-emitting device, so that the OLED light-emitting device has a lower driving voltage, a higher current efficiency and a longer service life.

[0114] It is to be noted that the relationship terms such as first and second, and the like, are used merely to differentiate one entity or action from another entity or action, and do not necessarily require or imply that there is any such actual relationship or order between such entities or actions. In addition, the terms "comprising", "including", or any other variant thereof are intended to cover a non-exclusive inclusion, such that processes, methods, articles, or apparatuses that comprise a list of elements are not required to include only those elements recited, but can include other elements not expressly listed or inherent to such processes, methods, articles, or apparatuses. Without further limitation, an element preceded by "comprises a" does not, without more constraints, foreclose the existence of additional identical elements in the process, method, article, or apparatus that comprises the recited element.

[0115] The above embodiments are only used to illustrate the technical solutions of the present application, but not intended to limit the present application; even though the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can be made to the technical solutions recorded in the foregoing embodiments, or equivalent replacements can be made to some of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

[0116] The present application is described by the above embodiments to illustrate the detailed process flow of the present application, but the present application is not limited to the above detailed process flow, that is, it does not mean that the present application must rely on the above detailed process flow to be implemented. Those skilled in the art should understand that any improvement of the present application, equivalent replacement of each raw material of the product of the present application, addition of auxiliary ingredients, selection of specific modes, etc., all fall within the protection scope and disclosure scope of the present application.

Claims

1. A triazine compound, characterized by, The triazine compound has a structure as shown in formula I: Wherein, R1, R2, and R3 are each independently selected from C1 to C2. 12 Alkyl group, 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, wherein At least one of the following conditions is met: The C1~C 12 The alkane group is selected from any one of methyl, ethyl, propyl, isopropyl, butyl, tert-butyl, pentyl, p-pentyl, n-hexyl, cyclohexyl, and methoxy. The C6~C 30 The aryl group is selected from any one of phenyl, biphenyl, terphenyl, naphthyl, anthracene, indole, fluorenyl, perylene, phenanthryl, pyrene, fluoranyl, or benzophenanthryl.

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

4. The triazine compound according to claim 1, wherein said C3-C20cycloalkyl is selected from cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, and cyclooctyl; 30 said aromatic hetero group is selected from any one of benzofuranyl, benzothiophenyl, pyridyl, dibenzofuranyl, pyrimidyl, dibenzothiophenyl, carbazolyl, phenyl- substituted carbazolyl, diaromatic aminyl, benzofuranocarbazolyl, benzofuranothiophenyl, triazinyl.

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

6. The triazine compound according to claim 1, wherein The triazine compound is selected from any one of compounds 1-12:

7. An organic electroluminescent device, characterized by The organic electroluminescent device includes the triazine compound according to any one of claims 1-6.

8. The organic electroluminescent device according to claim 7, wherein the organic electroluminescent device is a white organic electroluminescent device. 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 the triazine compound.

9. The organic electroluminescent device according to claim 8, wherein the organic electroluminescent device is a white organic electroluminescent device. The organic layer includes an electron transport layer. The material of the electron transport layer includes the triazine compound.

10. A display device, characterized by comprising: The display device includes the organic electroluminescent device according to any one of claims 7-9.

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