Triazine compound containing carbazole and benzocarbazole and application thereof

Abstract

The invention provides a triazine compound containing carbazole and benzocarbazole, and relates to the technical field of organic photoelectric materials. When the triazine compound containing carbazole and benzocarbazole is used as an electron transport layer material in the organic electroluminescent device, the driving voltage of the organic electroluminescent device can be effectively reduced, the current efficiency of the organic electroluminescent device is improved, and the service life of the organic electroluminescent device is prolonged.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of organic optoelectronics, and particularly relates to a triazine compound containing carbazole and benzocarbazole and application thereof. BACKGROUND

[0002] An organic light-emitting diode (OLED) has the advantages of light weight, small volume, wide viewing angle, fast response, wide temperature range of use, low energy consumption, high efficiency, good color purity, high definition, good flexibility, etc., and can meet new demands of consumers on display technology, and has good application prospects in the fields of lighting and display.

[0003] An organic electroluminescent element is a self-light-emitting element that utilizes the following principle: a fluorescent substance is made to emit light by the recombination energy of a hole injected from an anode and an electron injected from a cathode by applying an electric field. It has the following structure: an anode, a cathode, and an organic material layer interposed therebetween. In order to improve the efficiency and stability of the organic electroluminescent element, the organic material layer usually includes multiple layers having 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 having a specific wavelength when migrating to the ground state. The hole transport layer can change the hole transport efficiency of holes to the light-emitting layer, the light-emitting efficiency, the lifetime, and the like.

[0004] At present, research on organic electroluminescent materials has been widely carried out in academia and industry, and the design and search for compounds that can be used as new materials for OLEDs to overcome the deficiencies in the practical application process are the focus and future research and development trend of OLED material research work. SUMMARY

[0005] In view of the deficiencies of the prior art, the purpose of the present application is to provide a triazine compound containing carbazole and benzocarbazole and application thereof.

[0006] To achieve this purpose, the present application adopts the following technical solutions:

[0007] In a first aspect, the present application provides a triazine compound containing carbazole and benzocarbazole, which has a structure as shown in formula I:

[0008]

[0009] Formula I

[0010] R1 is selected from , any one of substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C3-C30 heteroaryl; R2 is selected from substituted or unsubstituted C6-C30 aryl;

[0011] L1 is selected from any one of C6-C30 arylene;

[0012] n is selected from an integer of 0-1;

[0013] In R1, R2, the substituted substituent is independently selected from any one of -D, -F, cyano, C1-C12 alkyl, C6-C30 aryl.

[0014] The triazine compound containing carbazole and benzocarbazole provided by the application has a specific molecular structure and spatial configuration, which endows it with excellent electron transport property and film-forming property, makes the electron transport layer more closely arranged, is conducive to the transport of carriers, reduces the driving voltage of the device, promotes the improvement of the efficiency of the device, prolongs the service life of the device, and comprehensively improves the comprehensive performance of the organic electroluminescent device.

[0015] Preferably, the hydrogen atoms in the compound shown in formula I can be independently substituted by any one of -D, -F, cyano, C1-C12 alkyl, C6-C30 aryl.

[0016] Preferably, the hydrogen atoms in the compound shown in formula I can be independently substituted by any one of -D, -F, cyano, C1-C12 alkyl, C6-C30 aryl.

[0017] Preferably, in R1, the C6-C30 aryl is selected from any one of phenyl, biphenyl, terphenyl, naphthyl, anthryl, indenyl, fluorenyl, perylenyl, phenanthryl, pyrenyl, fluoranthenyl, benzophenanthryl, the C3-C30 heteroaryl is selected from any one of benzofuranyl, benzothiophenyl, pyridyl, dibenzofuranyl, pyrimidyl, dibenzothiophenyl, carbazoyl, diarylamine, benzofuranocarbazoyl, benzofuranothiophenyl, triazinyl.

[0018] Preferably, in R1, the C6-C30 aryl is selected from any one of phenyl, biphenyl, naphthyl, fluorenyl, the C3-C30 heteroaryl is selected from any one of dibenzofuranyl, carbazoyl.

[0019] Preferably, in R2, the C6-C30 aryl is selected from any one of phenyl, biphenyl, terphenyl, naphthyl, anthryl, indenyl, fluorenyl, perylenyl, phenanthryl, pyrenyl, fluoranthenyl, benzophenanthryl.

[0020] Preferably, in R2, the C6-C30 aryl is selected from any one of phenyl, biphenyl, naphthyl.

[0021] Preferably, in R1, R2, each of the substituents is independently selected from any one of -D, -F, cyano, methyl, tert-butyl, phenyl, naphthyl.

[0022] Preferably, in L1, the C6-C30 arylene group is selected from any one of phenylene, biphenylene, terphenylene, naphthylene, anthrylene, indenylene, fluorenylene, pyrenylene, phenanthrylene, pyrenylene, chrysenylene, phenanthrolinylene.

[0023] Preferably, in L1, the C6-C30 arylene group is selected from any one of phenylene, biphenylene.

[0024] In the present application, when the substituents are contained in the substituted or unsubstituted groups, the number of substituents can be one or more than one, for example, the substituted or unsubstituted fluorenyl group can be 9,9-dimethylfluorenyl. When two or more substituents are simultaneously substituted on a group, the two or more substituents can be the same or different.

[0025] Preferably, the triazine compound containing carbazole and benzocarbazole is selected from any one of the following substituted or unsubstituted compounds:

[0026]

[0027]

[0028] ;

[0029] The substitution means that each of the hydrogen atoms in the above-mentioned triazine compound containing carbazole and benzocarbazole can be replaced by a deuterium atom.

[0030] Preferably, the triazine compound containing carbazole and benzocarbazole is selected from any one of compounds 1-12:

[0031] .

[0032] The present application lists some specific structural forms of the triazine compound containing carbazole and benzocarbazole, but the triazine compound containing carbazole and benzocarbazole of the present application is not limited to the listed chemical structures, and any structure based on the structure shown in formula I, L1, R1, R2 satisfying the above-mentioned limitation conditions should be included.

[0033] In a second aspect, the present application provides the use of the triazine compound containing carbazole and benzocarbazole as an electron transport material for an organic electroluminescent device.

[0034] Thirdly, the present invention provides an organic electroluminescent device comprising a triazine compound containing carbazole and benzocarbazole as described in the first aspect.

[0035] 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 organic layer includes the triazine compound containing carbazole and benzocarbazole.

[0036] Preferably, the organic layer includes an electron transport layer, which includes the aforementioned triazine compound containing carbazole and benzo[a]carbazole.

[0037] Fourthly, the present invention provides a display device comprising the organic electroluminescent device as described in the third aspect.

[0038] Compared with the prior art, the present invention has the following beneficial effects:

[0039] The triazine compounds containing carbazole and benzocarbazole provided by this invention have specific molecular structures and spatial configurations, endowing them with excellent electron transport properties and film-forming properties, making the electron transport layer more compact and facilitating carrier transport. As an electron transport layer material in organic electroluminescent devices, it can effectively reduce the driving voltage of organic electroluminescent devices, improve the current efficiency of organic electroluminescent devices, and improve the lifetime of organic electroluminescent devices. Detailed Implementation

[0040] To facilitate understanding of the present invention, the following embodiments are provided. Those skilled in the art should understand that these embodiments are merely illustrative and should not be construed as limiting the scope of the invention.

[0041] Synthesis Example 1

[0042] This embodiment provides a method for synthesizing compound 1, the method of which is as follows:

[0043]

[0044] (1) Synthesis of intermediate A1

[0045] 0.08 mol of raw material a1, 0.08 mol of raw material b1, 0.008 mol of dichlorodi-tert-butyl-(4-dimethylaminophenyl)phosphine palladium(II), 0.12 mol of potassium carbonate, and 600 mL of toluene were added to a reaction flask and heated to reflux for 8 h. The reaction was monitored by TLC until complete. The reaction solution was filtered through diatomaceous earth and washed with purified water until neutral. The organic phase was concentrated to obtain a solid. The obtained solid was washed with water and methanol, dried, and then separated by silica gel column chromatography. The solid was eluted with an eluent (composed of petroleum ether, ethyl acetate, and dichloromethane in a volume ratio of 3:1:1) to obtain intermediate A1.

[0046] The mass spectrometry data of intermediate A1 were tested, and the mass spectrometry m / z was measured to be 318.12.

[0047] (2) Synthesis of Compound 1

[0048] 0.06 mol of intermediate A1, 0.06 mol of starting material C1, 0.12 mmol of cesium carbonate, and 600 mL of DMF were added to a reaction flask and heated to reflux for 12 h. The reaction was monitored by TLC until complete. The reaction solution was poured into water and then filtered. The filter cake was washed with ethanol and recrystallized with toluene to obtain compound 1.

[0049] The mass spectrometry data of compound 1 were tested, and the mass spectrum m / z was measured to be 638.22.

[0050] Synthesis Example 2

[0051] Synthesis of compound 4:

[0052]

[0053] Following the same synthesis method as compound 1, compound 4 was obtained by replacing raw material c1 in synthesis example 1 with raw material c4, while keeping other conditions unchanged.

[0054] The mass spectrometry data of compound 4 were tested, and the mass spectrum m / z was measured to be 764.27.

[0055] Synthesis Example 3

[0056] Synthesis of compound 5:

[0057]

[0058] Following the same synthesis method as compound 1, compound 5 was obtained by replacing raw material c1 in synthesis example 1 with raw material c5, while keeping other conditions unchanged.

[0059] The mass spectrometry data of compound 5 were tested, and the mass spectrometry m / z was measured to be 896.31.

[0060] Synthesis Example 4

[0061] Synthesis of compound 7:

[0062]

[0063] Following the synthesis method of compound 1, compound 7 was obtained by replacing raw material c1 in synthesis example 1 with raw material c7, while keeping other conditions unchanged.

[0064] The mass spectrometry data of compound 7 were tested, and the mass spectrometry m / z was measured to be 830.32.

[0065] Synthesis Example 5

[0066] Synthesis of compound 8:

[0067]

[0068] Following the same synthesis method as compound 1, compound 8 was obtained by replacing raw material c1 in synthesis example 1 with raw material c8, while keeping other conditions unchanged.

[0069] The mass spectrometry data of compound 8 were tested, and the mass spectrum m / z was measured to be 804.26.

[0070] Synthesis Example 6

[0071] Synthesis of compound 11:

[0072]

[0073] (1) Synthesis of intermediate A11

[0074] 0.08 mol of raw material a1, 0.08 mol of raw material b1, 0.008 mol of dichlorodi-tert-butyl-(4-dimethylaminophenyl)phosphine palladium(II), 0.12 mol of potassium carbonate, and 600 mL of toluene were added to a reaction flask and heated to reflux for 8 h. The reaction was monitored by TLC until complete. The reaction solution was filtered through diatomaceous earth and washed with purified water until neutral. The organic phase was concentrated to obtain a solid. The obtained solid was washed with water and methanol, dried, and then separated by silica gel column chromatography. The eluent was composed of petroleum ether, ethyl acetate, and dichloromethane in a volume ratio of 5:1:1 to obtain intermediate A11.

[0075] The mass spectrometry data of intermediate A11 were tested, and the mass spectrometry m / z was measured to be 368.13.

[0076] (2) Synthesis of compound 11

[0077] 0.05 mol of intermediate A11, 0.05 mol of starting material c1, 0.1 mmol of cesium carbonate, and 600 mL of DMF were added to a reaction flask and heated to reflux for 12 h. The reaction was monitored by TLC until complete. The reaction solution was poured into water and then filtered. The filter cake was washed with ethanol and recrystallized with chlorobenzene to obtain compound 11.

[0078] The mass spectrometry data of compound 11 were tested, and the mass spectrum m / z was measured to be 764.27.

[0079] Synthesis Example 7

[0080] Synthesis of Compound 12

[0081]

[0082] (1) Synthesis of intermediate A12

[0083] Following the synthesis method of intermediate A11, raw material b12 was used to replace raw material b11 in synthesis example 6, while other conditions remained unchanged, to obtain intermediate A12.

[0084] The mass spectrometry data of intermediate A12 were tested, and the mass spectrometry m / z was measured to be 394.15.

[0085] (2) Synthesis of compound 12

[0086] Following the synthesis method of compound 11, intermediate A12 was substituted for intermediate A11 in synthesis example 6, while other conditions remained unchanged, to obtain compound 12.

[0087] The mass spectrometry data of compound 12 were tested, and the mass spectrum m / z was measured to be 790.28.

[0088] 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.

[0089]

[0090] .

[0091] The following device examples use the compounds of the present invention as electron transport materials in organic electroluminescent devices, while the device comparative examples use E1 to E3 as electron transport materials in organic electroluminescent devices.

[0092] Device Example 1

[0093] The structure of the organic electroluminescent device is as follows:

[0094] ITO / HT (40nm) / BH-1:BD-1 3% / Compound 1 (30nm) / LiF (0.5nm) / Al (150nm).

[0095] The fabrication method of the above-mentioned organic electroluminescent device is as follows:

[0096] The glass substrate coated with an ITO transparent conductive layer (as the anode) was ultrasonically treated in a cleaning agent, then rinsed in deionized water, then ultrasonically degreased in a mixed solvent of acetone and ethanol, then baked in a clean environment until completely dehydrated, cleaned with ultraviolet light and ozone, and bombarded with a low-energy cation beam to improve the surface properties and enhance the bonding ability with the hole injection layer.

[0097] The glass substrate was placed inside a vacuum chamber, and the vacuum was evacuated to 1×10⁻⁶. -5 ~9×10 -5 Pa, HT is vacuum-deposited on the anode as a hole transport layer at a deposition rate of 0.1 nm / s and a film thickness of 40 nm;

[0098] A light-emitting layer was vacuum-deposited on top of the hole transport layer at a deposition rate of 0.1 nm / s and a film thickness of 30 nm. The main material of the light-emitting layer was BH-1, and the doping material was BD-1. The 3% refers to the doping ratio of the doping material, that is, the volume ratio of the main material of the light-emitting layer to the doping material is 97:3.

[0099] Compound 1, an electron transport material, was vacuum-deposited as an electron transport layer on top of the luminescent layer at a deposition rate of 0.1 nm / s to achieve a film thickness of 30 nm. 0.5 nm of LiF and 150 nm of Al were then vacuum-deposited on the electron transport layer as an electron injection layer and a cathode, respectively. The brightness, driving voltage, current efficiency, and lifetime of the fabricated organic electroluminescent device were measured.

[0100] Device Examples 2-7

[0101] Device Examples 2-7 each provide an organic electroluminescent device, which differs from Device Example 1 only in that the electron transport material is different (see Table 1 below), while other conditions are the same as those in Device Example 1.

[0102] Device Comparison Examples 1-3

[0103] Comparative Examples 1 to 3 each provide an organic electroluminescent device, which differs from Device Example 1 only in that the electron transport material is different (see Table 1 below), while other conditions are the same as Device Example 1.

[0104] Performance testing

[0105] Test Method: The driving voltage, current efficiency, and lifetime LT90 of the OLED devices provided above were tested. LT90 refers to the time required for the brightness to decrease to 90% of its original brightness while maintaining an initial brightness of 1000 nits at a constant current density. Test items included the brightness, driving voltage, current efficiency, and lifetime LT90 of the organic light-emitting diode. The driving voltage, current efficiency, and LT90 data were all based on a brightness of 1000 cd / m². 2 The relative values ​​at different times (based on Comparative Example 1). The performance test results of the organic electroluminescent devices are shown in Table 1 below:

[0106] Table 1

[0107]

[0108] As shown in Table 1, this invention has obtained triazine compounds containing carbazole and benzocarbazole through molecular design, which can be used as electron transport materials for OLED light-emitting devices, enabling OLED light-emitting devices to have lower driving voltage, higher current efficiency and longer lifespan.

[0109] The present invention has been illustrated with the above embodiments to describe the detailed process flow of the present invention. However, the present invention is not limited to the above detailed process flow, that is, it does not mean that the present invention must rely on the above detailed process flow to be implemented. Those skilled in the art should understand that any improvements to the present invention, equivalent substitutions of the 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 containing carbazole and benzo carbazole, characterized by, The triazine compound containing carbazole and benzocarbazole has a structure as shown in Formula I: Formula I R1is selected from any one of R2is selected from substituted or unsubstituted C6-C30aryl; L1 is selected from any one of C6~C30 arylene groups; n is selected from an integer of 0~1; In R1, R2, the substituted substituent is independently selected from any one of -D, -F, cyano, C1~C12 alkyl, C6~C30 aryl.

2. The triazine compound containing carbazole and benzo carbazole according to claim 1, characterized by, In the compound of Formula I, the hydrogen atom can be independently substituted by any one of -D, -F, cyano, C1~C12 alkyl, C6~C30 aryl; Preferably, in the compound of Formula I, the hydrogen atom can be independently substituted by any one of -D, -F, cyano, methyl, tert-butyl, phenyl, naphthyl.

3. The triazine compound containing carbazole and benzo carbazole according to claim 1, characterized by, In R1, the C6~C30 aryl is selected from any one of phenyl, biphenyl, terphenyl, naphthyl, anthryl, indenyl, fluorenyl, perylenyl, phenanthryl, pyrenyl, fluoranthenyl, benzophenanthryl, and the C3~C30 heteroaryl is selected from any one of benzofuranyl, benzothiophenyl, pyridyl, dibenzofuranyl, pyrimidyl, dibenzothiophenyl, carbazolyl, diarylamino, benzofuranocarbazolyl, benzofuranothiophenyl, triazinyl. Preferably, in R1, the C6~C30 aryl is selected from any one of phenyl, biphenyl, naphthyl, fluorenyl, and the C3~C30 heteroaryl is selected from any one of dibenzofuranyl, carbazolyl.

4. The triazine compound containing carbazole and benzo carbazole according to claim 1, characterized by In R2, the C6~C30 aryl is selected from any one of phenyl, biphenyl, terphenyl, naphthyl, anthryl, indenyl, fluorenyl, perylenyl, phenanthryl, pyrenyl, fluoranthenyl, benzophenanthryl. Preferably, in R2, the C6~C30 aryl is selected from any one of phenyl, biphenyl, naphthyl.

5. The triazine compound containing carbazole and benzo carbazole according to claim 1, characterized by, In R1, R2, the substituted substituent is independently selected from any one of -D, -F, cyano, methyl, tert-butyl, phenyl, naphthyl.

6. The triazine compound containing carbazole and benzo carbazole according to claim 1, characterized by In L1, the C6~C30 arylene is selected from any one of phenylene, biphenylene, terphenylene, naphthylene, anthrylene, indenylene, fluorenylene, perylenylene, phenanthrylene, pyrenylene, fluoranthenylene, benzophenanthrylene. Preferably, in L1, the C6~C30 arylene is selected from any one of phenylene, biphenylene.

7. The triazine compound containing carbazole and benzo carbazole according to claim 1, characterized by, The triazine compound containing carbazole and benzocarbazole is selected from any one of the following substituted or unsubstituted compounds: ； The substitution means that the hydrogen atom in the above-mentioned triazine compound containing carbazole and benzocarbazole can be replaced by a deuterium atom independently; Preferably, the triazine compound containing carbazole and benzocarbazole is selected from any one of compounds 1~12: 。 8. Use of the triazine compound containing carbazole and benzocarbazole according to any one of claims 1~7 as an electron transport material of an organic electroluminescent device.

9. An organic electroluminescent device, characterized by The organic electroluminescent device comprises the triazine compound containing carbazole and benzocarbazole according to any one of claims 1~7.

10. The organic electroluminescent device according to claim 9, 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 organic layer comprises the triazine compound containing carbazole and benzocarbazole. Preferably, the organic layer includes an electron transport layer, and the electron transport layer includes the triazine compound containing carbazole and benzocarbazole. Preferably, the organic layer includes an electron transport layer, and the electron transport layer includes the triazine compound containing carbazole and benzocarbazole.

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