A compound and its use in organic electroluminescence devices

Abstract

The present invention protects a compound, as shown in the following formula (1): wherein: Ar 4 and Ar 5 are independently selected from one of substituted or unsubstituted C6-C 30 aryl, substituted or unsubstituted C3-C 30 heteroaryl; a and b are selected from 0 or 1; L is selected from a single bond, arylene, heteroarylene; L 1 -L 3 is selected from a single bond, arylene, heteroarylene; Ar 1 -Ar 3 are independently selected from one of C6-C 30 aryl or C3-C 30 heteroaryl; R 1 and R 2 are selected from one of hydrogen, deuterium, C1-C 12 alkyl, C1-C 12 alkoxy, halogen, cyano, nitro, hydroxyl, silyl, amino, C6-C 30 arylamino, C3-C 30 heteroarylamino, C6-C 30 aryl, C3-C 30 heteroaryl; c is an integer from 0 to 4; d is an integer from 0 to 2. The compound of the present invention exhibits excellent device performance and stability as a hole transport material or electron blocking material in OLED devices. The present invention also protects an organic electroluminescent device using the above compound.

Description

TECHNICAL FIELD

[0001] The present application relates to an organic compound which can be used as a hole transport layer material for an organic electroluminescent device, and the application also relates to the use of the compound in an organic electroluminescent device, and an organic electroluminescent device using the novel compound. BACKGROUND

[0002] OLED (Organic light-Emitting diode) display technology has the advantages of self-emission, high contrast, fast response speed, and high color saturation. In particular, it does not contain a backlight, has a simple device structure, a wide working temperature range, and can realize flexible display through a flexible substrate, so that it has become the next generation of display technology after LCD and has gradually shown its broad prospects for commercial applications.

[0003] The simplest OLED device structure is generally to evaporate tens to hundreds of nanometers of organic light-emitting material between two electrodes, and to make the material emit light by applying a certain voltage to the two electrodes. In order to achieve higher luminous efficiency and longer service life, various auxiliary layers need to be introduced to balance the transport of carriers, usually including a hole injection layer, a hole transport layer, an electron blocking layer, a hole blocking layer, an electron transport layer, and an electron injection layer. An organic electroluminescent device with good efficiency and long service life is usually the result of the optimization of the device structure and the combination of various organic materials. In order to achieve a device with lower working voltage, higher luminous efficiency, and longer service life, researchers have been working on the research and development of new organic electroluminescent materials in order to obtain higher performance materials and make OLED light-emitting devices achieve better working conditions.

[0004] In an OLED device, a hole transport material can improve the transport efficiency of holes in the device, which requires it to have a high hole mobility, and its highest molecular occupied orbital energy level (HOMO) to match the functional layer in contact with it, so as to achieve effective injection and transport of holes.

[0005] In patent JP2016084462A, a polycarbazole high molecular compound with carbazole as the skeleton is reported, which is characterized in that the 2,7 position of carbazole is substituted with an alkyl group; the 3,6 position is substituted with an amine group, and a high molecular chain is formed with 3,6 as the repeating unit.

[0006] In patent CN107108497A, a compound substituted at the 1,3 positions of carbazole is reported, which is characterized in that the substituents are independent aromatic amines or carbazole groups, and is a double amine or double carbazole compound structure.

[0007] Patent KR20170096767 reports a 2-amino-substituted, 3-aryl-substituted carbazole compound for use in organic hole transport materials.

[0008] The carbazole compounds reported above have shown good device performance, but in practical applications, it is still necessary to continuously improve and balance the hole mobility of the devices to meet the requirements of low driving voltage, high current efficiency, and long service life. Therefore, developing new hole transport materials remains one of the urgent tasks. Summary of the Invention

[0009] The purpose of this invention is to design a carbazole derivative that, by selecting substituents and substitution positions, ensures that the compound has a large conjugated plane and strong intramolecular electron transfer, thereby obtaining high thermal and optical stability, and in particular, excellent hole transport performance and high carrier mobility.

[0010] This invention provides a compound represented by the following general formula (1),

[0011]

[0012] in,

[0013] Ar 4 and Ar 5 Selected independently from C1 to C 16 Alkyl, C1-C 16 Alkoxy, C1-C 16 alkenyl, C1-C 16 Alkyne group, substituted or unsubstituted C6-C 30 Aryl, substituted or unsubstituted C3-C 30 One of the heterocyclic aryl groups;

[0014] Further preferred, Ar 4 and Ar 5 Each C6 to C6 is independently selected from substituted or unsubstituted C6 to C6. 18 Aryl, substituted or unsubstituted C3-C 18 One of the heterocyclic aryl groups;

[0015] Further optimized, Ar 4 and Ar 5 Each of the following groups, whether substituted or unsubstituted, is independently selected: ethyl, propyl, isopropyl, tert-butyl, vinyl, propynyl, phenyl, naphthyl, anthracene, phenanthryl, biphenyl, terphenyl, spirofluorenyl, carbazole, pyridyl, benzofuranyl, benzothiophene, fluoranyl, and fluorenyl.

[0016] a and b are each independently selected from 0 or 1, and a and b are not both 0 at the same time; preferably, a + b = 1.

[0017] L is selected from single bond, substituted or unsubstituted C6 to C6. 30 aryl, substituted or unsubstituted C3-C 30 One of the heteroaryl groups; preferably, L is a single bond.

[0018] L 1 -L 3 Whether identical or different, each is independently selected from single-bonded, substituted or unsubstituted C6 to C6 bonds. 30 aryl, substituted or unsubstituted C3-C 30 One of the heteroaryl groups; preferably a single bond or a phenylene group.

[0019] Ar 1 -Ar 3 Each C6 to C6 is selected independently from substituted or unsubstituted C6-C6. 30 Aryl or substituted or unsubstituted C3-C 30 Heterocyclic aryl;

[0020] Further preferred: Ar 1 -Ar 3 The following groups, individually or independently selected from substituted or unsubstituted groups: phenyl, biphenyl, fluorenyl, spirofluorenyl, carbazole, terphenyl, naphthyl, phenanthrene, benzo[a]phenanthrene, benzo[a]thiophene, benzo[a]furanyl, terphenyl, tetraphenyl, indene, benzo[a]fluorenyl, indene[a]fluorenyl, fluoranyl, triphenylene, pyrene, perylene, One of the following: benzo[a], tetraphenyl, dibenzothiophene, dibenzofuranyl, or dibenzo[selenophene];

[0021] Further optimized:

[0022] Ar 1 Selected from the following groups, whether substituted or unsubstituted: phenyl, biphenyl, or naphthyl;

[0023] Ar 2 and Ar 3 Each group is independently selected from the following groups, whether substituted or unsubstituted: phenyl, biphenyl, terphenyl, fluorenyl, spirofluorenyl, carbazolyl, naphthyl, phenanthryl, dibenzofuranyl, and dibenzothiopheneyl.

[0024] R 1 and R 2 They may be the same or different, and each is independently selected from hydrogen, deuterium, C1 to C2. 12 Alkyl, C1-C 12 Alkoxy, halogen, cyano, nitro, hydroxyl, silyl, amino, substituted or unsubstituted C6-C 30arylamino, substituted or unsubstituted C3-C 30 heteroarylamino, substituted or unsubstituted C6-C 30 Aryl, substituted or unsubstituted C3-C 30 One of the heteroaryl groups;

[0025] R 1 and R 2 Each can independently fuse with the connected benzene ring to form C9-C12 rings. 30 The aryl or heteroaryl group formed is optionally surrounded by 0, 1, 2, 3, 4, or 5 independently selected C1-C1 atoms, either substituted or unsubstituted. 12 Alkyl, halogen, cyano, nitro, hydroxyl, silyl, substituted or unsubstituted C6-C 30 Aryl, substituted or unsubstituted C3-C 30 Substituents in heteroaryl groups are replaced.

[0026] c is an integer from 0 to 4; d is an integer from 0 to 2.

[0027] Furthermore, d can be either 0 or 1.

[0028] Further preferred, R 1 and R 2 They may be the same or different, and each is independently selected from one of methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, cyclohexyl, trifluoromethyl, vinyl, propenyl, ethynyl, propynyl, benzene, naphthalene, anthracene, fluoranthene, biphenyl, fluorene, spirodifluorene, furan, thiophene, and pyridine.

[0029] When the above groups contain substituents, the substituents are independently selected from halogens, cyano groups, C1-C1 groups, etc. 10 Alkyl or cycloalkyl, C2-C6 alkenyl or cycloalkenyl, C1-C6 alkoxy or thioalkoxy, C6-C 30 aryl, C3~C 30 Heterocyclic aryl groups.

[0030] Furthermore, general formula (1) is preferably shown in general formula (2-1) or (2-2) as follows:

[0031]

[0032] In general formulas (2-1) and (2-2), the definitions of each substituent group are the same as in general formula (1).

[0033] Examples of preferred structures for the compounds involved in this invention include compounds with the structures shown in C1 to C252, but are not limited to these compounds.

[0034]

[0035]

[0036]

[0037]

[0038]

[0039]

[0040]

[0041]

[0042]

[0043]

[0044]

[0045] The research finds that the compound of the above general formula has good film forming property, and is suitable for being used as a hole transport material or an electron blocking material in an organic electroluminescent device.

[0046] The compound of the present application takes carbazole as a mother nucleus, introduces an amine group at the 3-position, makes the lone pair of electrons on the nitrogen atom and the aromatic system realize a large degree of n-pi conjugation, improves the HOMO energy level of the molecule, is beneficial to the injection of holes, and at the same time, introduces a specific substituent group at the ortho position of the amine group, so that the space configuration of the triarylamine is twisted due to the influence of the specific substituent group, increases the steric hindrance of the original triarylamine molecule, makes the space configuration of the molecule not easy to deflect, thereby enhancing the molecular junction stability, and further increasing the charge mobility of the molecule.

[0047] The compound of the present application can further specifically optimize and design the arylamine connected L2-Ar 2 and L3-Ar 3 groups on the basis of the general mother nucleus structure, and such a molecular structure can ensure that the compound of the present application has good charge transport capacity.

[0048] The compound of the present application can further introduce other substituents on the carbazole ring on the basis of the above structure, broaden the conjugation of the molecule, further regulate the HOMO energy level of the molecule, optimize the spatial configuration of the molecule, improve the stereoscopic degree of the spatial structure of the molecule, make the molecule tightly packed in the evaporation process, and enhance the charge transport capacity of the molecule. The introduction of the rigid structure group can also improve the Tg of the compound, enhance the thermal stability, and thus realize higher working efficiency and service life of the device.

[0049] When the compound of the present application is applied to the organic electroluminescent device, the driving voltage of the device can be reduced, the service life of the device can be increased, and better device performance can be obtained. DETAILED DESCRIPTION

[0050] In order to enable those skilled in the art to better understand the present application, the present application will be further described in detail below in combination with specific embodiments.

[0051] The compounds of the synthesis methods not mentioned in the examples are all raw material products obtained by commercial channels. The various chemicals used in the examples, such as petroleum ether, ethyl acetate, toluene, tetrahydrofuran, N,N-dimethylformamide, dichloromethane, cesium carbonate, potassium carbonate, palladium acetate, 2-dicyclohexylphosphine-2,4,6-triisopropylbiphenyl (XPhos), 2-dicyclohexylphosphine-2',6'-dimethoxybiphenyl (SPhos), tetrakis(triphenylphosphine)palladium, bis(4-biphenyl)amine, carbazole, 1-bromo-3-chloro-5-fluorobenzene, 4-biphenylboronic acid, sodium tert-butoxide, and the like basic chemical raw materials can be purchased in the domestic chemical product market.

[0052] The analysis and detection of the intermediates and compounds in the present application use ABSCIEX mass spectrometer (4000QTRAP) and Bruker nuclear magnetic resonance instrument (400M).

[0053] The present application will be described more specifically with reference to the following examples, but the present application is not limited to these examples. The compound represented by the general formula (1) of the present application can obtain the desired compound by the synthesis route shown below.

[0054] The general synthesis route of the compounds (1-168) described in the present application:

[0055]

[0056] The synthesis route of the compounds (169-240) described in the present application

[0057]

[0058] Synthesis of Example 1:

[0059] Synthesis of compound C1

[0060]

[0061] Synthesis of intermediate 1-1

[0062] In a four-necked flask equipped with a condenser, the starting compound N-phenyl-2-hydroxycarbazole (25.9 g, 0.1 mol) was dissolved in dichloromethane (500 mL) and the reaction system was cooled to 0 °C in an ice-water bath. Then NBS (5.6 g, 0.1 mmol) was slowly added to the above solution in batches, and the reaction temperature was controlled. After NBS was completely added to the system, stirring was continued for 1 h, and TLC monitoring was performed until the starting material disappeared. Then the reaction solution was poured into 500 mL of an aqueous ammonium chloride solution and extracted. The aqueous phase was extracted with 200 mL of dichloromethane, and the combined organic phases were dried over anhydrous sodium sulfate and concentrated to obtain a yellow solid. The crude product was further purified by silica gel column chromatography to obtain a light yellow solid 25 g.

[0063] Synthesis of intermediate 1-2

[0064] In a three-necked flask equipped with a condenser, compound 1-1 (15 g, 44 mmol) and triethylamine (5.8 g, 57.6 mmol) were dissolved in 200 mL of dichloromethane, and then cooled to 0 °C in an ice-water bath. Acetyl chloride (4.2 g, 53.2 mmol) was dissolved in 15 mL of dichloromethane, and slowly added to the above solution through a constant pressure dropping funnel. The solution color became dark, and after the addition was completed, the reaction system was slowly warmed to room temperature and stirring was continued for 2 h. TLC monitoring was performed until the starting material completely reacted. Then the solution was poured into a saturated ammonium chloride solution, and extracted. The aqueous phase was extracted with 50 mL of dichloromethane, and the combined organic phases were dried over anhydrous sodium sulfate and concentrated to obtain a brownish yellow oil, which was directly used in the next step.

[0065] Synthesis of intermediate 1-3

[0066] Compound 1-2 (17 g, 44.3 mmol), bis(4-biphenyl)amine (17.24 g, 53.7 mmol), and sodium tert-butoxide (6.45 g, 67.1 mmol) were added to 250 mL of toluene, stirred and dissolved, and then replaced with nitrogen. Pd2(dba)3 (410 mg, 0.447 mmol) and SPhos (734 mg, 1.79 mmol) were added. Under the protection of nitrogen, the reaction was warmed to reflux for 20 h, and TLC monitoring was performed until the starting material completely reacted. Then the temperature was lowered to room temperature, and the solution was extracted with a saturated ammonium chloride solution. The aqueous phase was extracted with toluene (150 mL*2), and the combined organic phases were washed once more with saturated brine, dried over anhydrous sodium sulfate, filtered, and concentrated to obtain the crude product. Further purification by silica gel column chromatography yielded a yellow solid 18 g.

[0067] Synthesis of intermediate 1-4

[0068] Compound 1-3 (18 g) was added to methanol (100 mL) and THF (100 mL), then 1 N NaOH solution was added, and the reaction was stirred for 24 h. The system was extracted with ethyl acetate and dried over anhydrous sodium sulfate. The crude product was concentrated and directly used in the next step after being dried thoroughly.

[0069] Synthesis of intermediate 1-5

[0070] Compound 1-4 (15 g, 25.9 mmol) and pyridine (4.1 g, 51.8 mmol) were dissolved in chloroform (250 mL) and stirred thoroughly. The solution was cooled to 0°C in an ice water bath, and then trifluoromethanesulfonic anhydride (9.5 g, 33.7 mmol) was added dropwise. After the addition was completed, the solution was gradually warmed to room temperature and reacted for 3 h until the starting material was completely reacted. Then the solution was poured into a saturated ammonium chloride solution, extracted with dichloromethane, and the organic phase was washed once with a saturated NaCl solution, dried over anhydrous sodium sulfate, filtered, and concentrated to obtain a brown oil. The product was purified by column chromatography to obtain 15 g of a yellow solid.

[0071] Synthesis of compound C1

[0072] Compound 1-4 (14 g, 19.7 mmol), phenylboronic acid (2.9 g, 23.64 mmol), and potassium carbonate (4.1 g, 29.6 mmol) were added to a three-necked flask containing toluene (150 mL), ethanol (70 mL), and water (70 mL) and stirred thoroughly. Then, under nitrogen protection, tetrakis(triphenylphosphine)palladium (228 mg, 0.197 mmol) was added, and the reaction system was warmed to 90°C and reacted for 20 h. After cooling, the reaction solution was poured into 300 mL of a saturated ammonium chloride aqueous solution and extracted, and the aqueous phase was extracted twice with toluene (100 mL). The combined organic phase was dried over anhydrous sodium sulfate, concentrated, and the crude product was purified by silica gel column chromatography (petroleum ether / dichloromethane = 8 / 1) to obtain a yellow solid. The solid was recrystallized with toluene and methanol to obtain a light yellow solid (8 g).

[0073] Synthesis Example 2:

[0074] Synthesis of compound C9

[0075] For the synthesis of a typical reference compound C1, bis(4-biphenyl)amine M1 was replaced with an equivalent amount of 9-1.

[0076]

[0077] Synthesis Example 3:

[0078] Synthesis of compound C13

[0079] Synthesis of a typical reference compound C1, replacing di(4- biphenyl)amine M1 by an equivalent amount of 17-1.

[0080]

[0081] Synthesis example 4:

[0082] Synthesis of compound C17

[0083] Synthesis of a typical reference compound C1, replacing di(4- biphenyl)amine M1 by an equivalent amount of 17-1.

[0084]

[0085] Synthesis example 5:

[0086] Synthesis of compound C18

[0087] Synthesis of a typical reference compound C1, replacing di(4- biphenyl)amine M1 by an equivalent amount of 18-1.

[0088]

[0089] Synthesis example 6:

[0090] Synthesis of compound C25

[0091] Synthesis of a typical reference compound C1, replacing di(4- biphenyl)amine M1 by an equivalent amount of 25-1.

[0092]

[0093] Synthesis example 7:

[0094] Synthesis of compound C63

[0095] Synthesis of a typical reference compound C1, replacing di(4- biphenyl)amine M1 by an equivalent amount of 63-1.

[0096]

[0097] Synthesis example 8:

[0098] Synthesis of compound C66

[0099] Synthesis of a typical reference compound C1, replacing phenylboronic acid M2 by an equivalent amount of 1 -naphthaleneboronic acid.

[0100] Synthesis example 9:

[0101] Synthesis of compound C117

[0102] Synthesis of a typical reference compound C1, replacing phenylboronic acid M2 with an equivalent amount of 2-naphthylboronic acid.

[0103] Synthesis of Example 10:

[0104] Synthesis of compound C199

[0105]

[0106] Synthesis of intermediate 199-1

[0107] Dissolve N-phenyl-2,7-dibromocarbazole (25 g, 62.3 mmol) in acetic acid (400 mL), add nitric acid (5.89 g, 93.5 mmol), heat to 60 °C, then slowly add concentrated sulfuric acid (6.72 g, 68.6 mmol) into the above solution through a constant pressure dropping funnel, solid gradually precipitates, after the dropping is completed, continue stirring for 2 h, then cool down. Pour the reaction solution into 1 L of ice water, stir well, collect the solid by filtration, wash the solid with water, and dry to obtain 25 g, which is directly used in the next step.

[0108] Synthesis of intermediate 199-2

[0109] Put compound 199-1 (25 g, 56.0 mmol), phenylboronic acid (15.0 g, 23.3 mmol) and potassium carbonate (23.2 g, 168.1 mmol) into a three-necked flask containing dioxane (300 mL) and water (100 mL), fully replace with nitrogen, add Pd(PPh3)4 (1.3 g, 1.12 mmol), heat to 100 °C and react for 20 h. Cool down, pour the reaction solution into 500 mL of saturated aqueous ammonium chloride solution, extract with ethyl acetate (200 mL*3), combine the organic phases, wash once with saturated brine, and dry over anhydrous sodium sulfate. Concentrate to obtain an oil, purify on a silica gel column (PE / EA, 10 / 1) to obtain 20 g of a yellow solid.

[0110] Synthesis of intermediate 199-3

[0111] Put the above compound 199-2 (20 g) into a single-necked flask containing methanol (200 mL) and THF (200 mL), add Pd / C hydrate (1 g), then fully replace the air in the flask with a hydrogen gas bag, and keep the hydrogen pressure, fully stir for 24 h. After the reaction is completed, remove the palladium carbon in the filtrate by filtration, concentrate the filtrate to obtain a light yellow solid, and purify the solid on a silica gel column to obtain a white solid (15 g).

[0112] Synthesis of compound C199

[0113] Compound 199-3 (15 g, 36.5 mmol), 4-bromobiphenyl (18.7 g, 80.4 mmol) and potassium carbonate (15.2 g, 109.6 mmol) were put into a three-necked flask, toluene (200 mL) was added, nitrogen was sufficiently replaced, then Pd2(dba)3(669 mg, 0.731 mmol), SPhos (900 mg, 2.19 mmol) were added under nitrogen protection, the temperature was increased to reflux under sufficient stirring, and the reaction was carried out for 20 h. After cooling, the reaction solution was poured into 500 mL of saturated ammonium chloride solution, extracted, the aqueous phase was extracted once with toluene (200 mL), the organic phases were combined, dried over anhydrous sodium sulfate, and concentrated to obtain a brown oil. The crude product was purified by silica gel column (PE / DCM, 8 / 1) to obtain a yellow solid, which was recrystallized with toluene and n-hexane to obtain a light yellow solid 12 g.

[0114] Different target compounds can be obtained by replacing different Ar-X2 (sometimes referred to as aryl halide in the art). It should be noted that the Buchwald-Hartwig coupling method is used in the above-mentioned synthesis method of arylamine, but it is not limited to this coupling method, and other methods can also be selected by those skilled in the art, such as Stille coupling method, Grignard reagent method, Kumada-Tamao and other known methods, but not limited to these methods, any equivalent synthesis method can be selected as needed to achieve the purpose of connecting substituents A1 and A2 to the benzopyrene ring.

[0115] Device example

[0116] Embodiment

[0117] The OLED includes a first electrode and a second electrode, and an organic material layer between the electrodes. The organic material can be further divided into multiple regions. For example, the organic material layer can include a hole transport region, a light emitting layer, and an electron transport region.

[0118] In specific embodiments, a substrate can be used below the first electrode or above the second electrode. The substrate is a glass or a polymer material with excellent mechanical strength, thermal stability, waterproofness, and transparency. In addition, a thin film transistor (TFT) can also be provided on the substrate for display.

[0119] The first electrode can be formed by sputtering or depositing a material used as the first electrode on the substrate. When the first electrode is used as an anode, an oxide transparent conductive material such as indium tin oxide (ITO), indium zinc oxide (IZO), tin dioxide (Sn02), zinc oxide (ZnO), and the like, and any combination thereof can be used. When the first electrode is used as a cathode, a metal or an alloy such as magnesium (Mg), silver (Ag), aluminum (Al), aluminum-lithium (Al-Li), calcium (Ca), magnesium-indium (Mg-In), magnesium-silver (Mg-Ag), and the like, and any combination thereof can be used.

[0120] The organic material layer can be formed on the electrode by vacuum thermal evaporation, spin coating, printing, or the like. The compound used as the organic material layer can be an organic small molecule, an organic macromolecule, and a polymer, and combinations thereof.

[0121] The hole transport zone is located between the anode and the light emitting layer. The hole transport zone can be a single layer structure of a hole transport layer (HTL), including a single layer hole transport layer containing only one compound and a single layer hole transport layer containing multiple compounds. The hole transport zone can also be a multi-layer structure including at least one of a hole injection layer (HIL), a hole transport layer (HTL), and an electron blocking layer (EBL).

[0122] The material of the hole transport zone can be selected from, but not limited to, a phthalocyanine derivative such as CuPc, a conductive polymer or a polymer containing a conductive dopant such as polyphenylene vinylene, polyaniline / dodecylbenzenesulfonic acid (Pani / DBSA), poly(3,4-ethylenedioxythiophene) / poly(4-styrenesulfonate) (PEDOT / PSS), polyaniline / camphor sulfonic acid (Pani / CSA), polyaniline / poly(4-styrenesulfonate) (Pani / PSS), an aromatic amine derivative such as the compounds shown in HT-1 to HT-34 below; or any combination thereof.

[0123]

[0124]

[0125] The hole injection layer is located between the anode and the hole transport layer. The hole injection layer can be a single compound material or a combination of multiple compounds. For example, the hole injection layer can use one or more of the compounds of HT-1 to HT-35 described above, or one or more of the compounds of HI1-HI3 described below; or one or more of the compounds of HT-1 to HT-35 doped with one or more of the compounds of HI1-HI3 described below.

[0126]

[0127] The light-emitting layer can include light-emitting dyes (i.e., dopants) that can emit different wavelengths of light, and can also include host materials. The light-emitting layer can be a single-color light-emitting layer that emits a single color such as red, green, blue, etc. Multiple single-color light-emitting layers of different colors can be arranged in a planar pattern according to a pixel pattern, or can be stacked together to form a color light-emitting layer. When different color light-emitting layers are stacked together, they can be separated from each other, or can be connected to each other. The light-emitting layer can also be a single-color light-emitting layer that can emit multiple colors such as red, green, blue, etc. simultaneously.

[0128] Depending on the technology, the light-emitting layer material can employ fluorescent electroluminescent materials, phosphorescent electroluminescent materials, thermally activated delayed fluorescence light-emitting materials, etc. In an OLED device, a single light-emitting technology can be employed, or a combination of multiple different light-emitting technologies can be employed. These different light-emitting materials classified by technology can emit the same color of light, or can emit different colors of light.

[0129] In an aspect of the present application, the light-emitting layer employs phosphorescent electroluminescent technology. The host material of the light-emitting layer can be selected from, but not limited to, a combination of one or more of GPH-1 to GPH-80.

[0130]

[0131]

[0132]

[0133]

[0134] In an aspect of the present application, the light-emitting layer employs phosphorescent electroluminescent technology. The phosphorescent dopant of the light-emitting layer can be selected from, but not limited to, a combination of one or more of GPD-1 to GPD-47 listed below.

[0135]

[0136]

[0137] In an aspect of the present application, the light-emitting layer employs phosphorescent electroluminescent technology. The host material of the light-emitting layer can be selected from, but not limited to, a combination of one or more of RH-1 to RH-31.

[0138]

[0139]

[0140] In one aspect of the present application, the light-emitting layer employs phosphorescent electroluminescent technology. The phosphorescent dopant of the light-emitting layer can be selected from, but not limited to, a combination of one or more of RPD-1 to RPD-28 listed below.

[0141]

[0142]

[0143] In one aspect of the present application, the light-emitting layer employs phosphorescent electroluminescent technology. The phosphorescent dopant of the light-emitting layer can be selected from, but not limited to, a combination of one or more of YPD-1 to YPD-11 listed below.

[0144]

[0145]

[0146] In one aspect of the present application, the light-emitting layer employs fluorescent electroluminescent technology. The fluorescent host material of the light-emitting layer can be selected from, but not limited to, a combination of one or more of BFH-1 to BFH-16 listed below.

[0147]

[0148] In one aspect of the present application, the light-emitting layer employs fluorescent electroluminescent technology. The fluorescent dopant of the light-emitting layer can be selected from, but not limited to, a combination of one or more of BFD-1 to BFD-12 listed below.

[0149]

[0150]

[0151] The OLED organic material layer can further include an electron transport zone between the light-emitting layer and the cathode. The electron transport zone can be an electron transport layer (ETL) in a single layer structure, including a single layer electron transport layer containing only one compound and a single layer electron transport layer containing multiple compounds. The electron transport zone can also be a multi-layer structure including at least one of an electron injection layer (EIL), an electron transport layer (ETL), and a hole blocking layer (HBL).

[0152] In one aspect of the present application, the electron transport layer material can be selected from, but not limited to, a combination of one or more of ET-1 to ET-57 listed below.

[0153]

[0154]

[0155]

[0156]

[0157] An electron injection layer can also be included in the device between the electron transport layer and the cathode, and the electron injection layer material includes, but is not limited to, one or more of the following in combination.

[0158] LiQ, LiF, NaCl, CsF, Li2O, Cs2CO3, BaO, Na, Li, Ca.

[0159] The cathode material can be selected from, but not limited to, a magnesium silver mixture, LiF / Al, ITO and other metals, metal mixtures, oxides.

[0160] The compound of the present application can preferably be used as a hole transport material in the organic functional layer of an organic electroluminescent device, and the compounds HT-17, HT-35, HT36 and HT37 in the prior art are simultaneously selected as the hole transport materials in Comparative Example 1, Comparative Example 2, Comparative Example 3 and Comparative Example 4, respectively.

[0161] The following detailed disclosure of the preparation process of the organic electroluminescent device prepared by the present application is disclosed in each of the comparative examples and examples of the present application:

[0162] The following comparative examples use the compounds in the prior art as hole transport materials.

[0163] Comparative Example 1:

[0164] The glass plate coated with an ITO transparent conductive layer is ultrasonically treated in a commercial cleaning agent, rinsed in deionized water, ultrasonically degreased in an acetone: ethanol mixed solvent, baked in a clean environment until the water is completely removed, cleaned with ultraviolet light and ozone, and the surface is bombarded with a low-energy cation beam;

[0165] The glass substrate with the anode described above is placed in a vacuum chamber, vacuumed to 1 x 10 -5 ~ 9 x 10 -3 Pa, and HI-1 is vacuum evaporated as a hole injection layer on the anode layer film, the evaporation rate is 0.1 nm / s, and the evaporation film thickness is 10 nm;

[0166] HT-17 is vacuum evaporated as a hole transport layer of the device on the hole injection layer, the evaporation rate is 0.1 nm / s, and the total evaporation film thickness is 80 nm;

[0167] The light-emitting layer of the device is vacuum evaporated on the hole transport layer, and the light-emitting layer comprises a host material and a dye material. The host material BFH4 is evaporated at a rate of 0.1 nm / s, and the dye BFD-2 is evaporated at a rate of 3% of the total film thickness, and the total film thickness is 30 nm.

[0168] The electron transport layer material ET29 of the device is vacuum evaporated on the light-emitting layer, and the evaporation rate is 0.1 nm / s, and the total film thickness is 30 nm.

[0169] A LiF layer with a thickness of 0.5 nm is vacuum evaporated on the electron transport layer (ETL) as an electron injection layer, and an Al layer with a thickness of 150 nm is used as the cathode of the device.

[0170] Comparative Example 2

[0171] An organic electroluminescent device is prepared by the same method as in the comparative example, except that HT-17 is replaced by compound HT-35.

[0172] Comparative Example 3

[0173] An organic electroluminescent device is prepared by the same method as in the comparative example, except that HT-17 is replaced by compound HT-36.

[0174] Comparative Example 4

[0175] An organic electroluminescent device is prepared by the same method as in the comparative example, except that HT-17 is replaced by compound HT-37.

[0176] The following examples are preferred specific compounds of the general formula of the application used as hole transport materials.

[0177] Example 1

[0178] An organic electroluminescent device is prepared by the same method as in Comparative Example 1, except that HT-17 is replaced by compound C1 synthesized in the application.

[0179] Example 2

[0180] The compound of the application is used as a hole transport material.

[0181] An organic electroluminescent device is prepared by the same method as in the comparative example, except that HT-17 is replaced by compound C14 synthesized in the application.

[0182] Example 3

[0183] An organic electroluminescence device was prepared by the same method as the comparative example, except that HT-17 was replaced by the compound C20 synthesized in the present application.

[0184] Example 4

[0185] An organic electroluminescence device was prepared by the same method as the comparative example, except that HT-17 was replaced by the compound C26 synthesized in the present application.

[0186] Example 5

[0187] An organic electroluminescence device was prepared by the same method as the comparative example, except that HT-17 was replaced by the compound C36 synthesized in the present application.

[0188] Example 6

[0189] An organic electroluminescence device was prepared by the same method as the comparative example, except that HT-17 was replaced by the compound C48 synthesized in the present application.

[0190] Example 7

[0191] An organic electroluminescence device was prepared by the same method as the comparative example, except that HT-17 was replaced by the compound C70 synthesized in the present application.

[0192] Example 8

[0193] An organic electroluminescence device was prepared by the same method as the comparative example, except that HT-17 was replaced by the compound C74 synthesized in the present application.

[0194] Example 9

[0195] An organic electroluminescence device was prepared by the same method as the comparative example, except that HT-17 was replaced by the compound C97 synthesized in the present application.

[0196] Example 10

[0197] An organic electroluminescence device was prepared by the same method as the comparative example, except that HT-17 was replaced by the compound C199 synthesized in the present application.

[0198] Method for testing the device (including equipment and testing conditions):

[0199] The organic electroluminescence device prepared by the above process was subjected to the following performance determination:

[0200] The driving voltage and current efficiency of the organic electroluminescent devices prepared in the examples and comparative examples were measured using a digital source meter and a luminance meter at the same brightness, and the lifetime of the devices was measured. Specifically, the voltage was increased at a rate of 0.1 V per second, and the voltage at which the brightness of the organic electroluminescent device reached 1000 cd / m 2 was measured, i.e., the driving voltage, and the current density at that time was measured; the ratio of the brightness to the current density was the current efficiency.

[0201] The performance of the organic electroluminescent devices prepared in the present application is shown in Table 1 below.

[0202] Table 1:

[0203] Device example number Number of hole transport material Requesting brightness cd / m 2 ]] Voltage V Current efficiency cd / A Comparative example 1 HT-17 1000.00 5.5 6.0 Comparative example 2 HT-35 1000.00 5.8 6.3 Comparative example 3 HT-36 1000.00 5.6 5.6 Comparative example 4 HT-37 1000.00 4.7 6.3 Example 1 C1 1000.00 4.6 8.6 Example 2 C14 1000.00 4.3 8.8 Example 3 C20 1000.00 4.4 9.5 Example 4 C26 1000.00 4.5 9.6 Example 5 C36 1000.00 4.5 8.8 Example 6 C48 1000.00 4.3 8.5 Example 7 C70 1000.00 4.5 8.8 Example 8 C74 1000.00 4.4 8.6 Example 9 C97 1000.00 4.5 8.9 Example 10 C199 1000.00 4.4 9.2

[0204] As can be seen from the comparison of the performance data of each of the comparative examples and each of the examples in Table 1 above, in the case where the other materials in the structure of the organic electroluminescent device prepared in the present application are the same, the device prepared using the compound of the present application as the hole transport material has a lower starting voltage and improved current efficiency compared to the device using the compound in the prior art as the hole transport material.

[0205] The above results show that the novel organic material of the present application used as the hole transport material in the organic electroluminescent device can effectively reduce the starting voltage, improve the current efficiency, and has good stability.

[0206] Each of the following comparative examples uses a compound in the prior art as the electron blocking material.

[0207] Comparative Example 5:

[0208] The glass plate coated with the ITO transparent conductive layer was ultrasonically treated in a commercial cleaning agent, rinsed in deionized water, ultrasonically degreased in a mixture of acetone and ethanol, baked in a clean environment until the water was completely removed, cleaned with ultraviolet light and ozone, and the surface was bombarded with a low-energy cation beam;

[0209] The glass substrate with the anode was placed in a vacuum chamber, vacuumed to 1 x 10 -5 ~ 9 x 10 -3 Pa, and HI-1 was vacuum deposited as a hole injection layer on the anode layer film at a deposition rate of 0.1 nm / s and a film thickness of 10 nm;

[0210] HT-4 was vacuum deposited as a hole transport layer of the device on the hole injection layer at a deposition rate of 0.1 nm / s and a total film thickness of 80 nm;

[0211] Vacuum deposition of HT-8 as the electron blocking layer of the device on the hole transport layer, the deposition rate is 0.1 nm / s, and the total film thickness is 8 nm;

[0212] Vacuum deposition of the light-emitting layer of the device on the electron blocking layer, the light-emitting layer comprising a host material and a dye material, using the method of multi-source co-evaporation, adjusting the deposition rate of the host material BFH4 to be 0.1 nm / s, the deposition rate of the dye BFD-2 to be 3% proportion, and the total film thickness to be 30 nm;

[0213] Vacuum deposition of the electron transport layer material ET29 of the device on the light-emitting layer, the deposition rate being 0.1 nm / s, and the total film thickness being 30 nm;

[0214] Vacuum deposition of LiF with a thickness of 0.5 nm as the electron injection layer on the electron transport layer (ETL), and deposition of an Al layer with a thickness of 150 nm as the cathode of the device.

[0215] Example 11

[0216] An organic electroluminescent device is prepared by using the same method as in Comparative Example 1, except that HT-8 is replaced by the compound C152 synthesized in the application.

[0217] Example 12

[0218] An organic electroluminescent device is prepared by using the same method as in Comparative Example 1, except that HT-8 is replaced by the compound C175 synthesized in the application.

[0219] Example 13

[0220] An organic electroluminescent device is prepared by using the same method as in Comparative Example 1, except that HT-8 is replaced by the compound C204 synthesized in the application.

[0221] Example 14

[0222] An organic electroluminescent device is prepared by using the same method as in Comparative Example 1, except that HT-8 is replaced by the compound C189 synthesized in the application.

[0223] The performance of the organic electroluminescent device prepared in the application is shown in Table 2 below.

[0224] Table 2:

[0225] Device example number Number of electron blocking layer material Requesting luminance cd / m 2 ]]> Voltage V Current efficiency cd / A Comparative example 5 HT-8 1000.00 5.6 6.0 Example 11 C152 1000.00 4.3 7.8 Example 12 C175 1000.00 4.3 8.2 Example 13 C204 1000.00 4.1 8.5 Example 14 C189 1000.00 4.2 9.3

[0226] The above results show that the novel organic material of the application can be used as the material of the electron blocking layer of the organic electroluminescent device, and compared with the comparative examples, the material of the application has obvious improvement on the voltage and efficiency of the device.

[0227] Although the present application has been described in connection with the embodiments thereof, it will be understood that modifications and improvements can be made thereto without departing from the spirit and scope of the application as set forth in the appended claims.

Claims

1. A compound of the general formula (2-1): ###0001### (2-1) wherein: a is 0 or 1; b is 0 or 1; c is 0 or 1; d is 0; R1 is H, F, Cl, Br, I, CN, N02, CF3, CH3, C2F5, C3F7, C4F9, C5F11, C6F13, C7F15, C8F17, C9F19, C10F21, C11F23, C12F25, C13F27, C14F29, C15F31, C16F33, C17F35, C18F37, C19F39, C20F41, C21F43, C22F45, C23F47, C24F49, C25F51, C26F53, C27F55, C28F57, C29F59, C30F61, C31F63, C32F65, ； ​ Ar 4 each independently selected from one of: phenyl, naphthyl, anthryl, phenanthryl, biphenyl, terphenyl, spirofluorenyl, pyridyl, benzofuranyl, benzothiophenyl, fluoranthenyl, fluorenyl; L is a single bond, L 1 , L 2 and L 3 are each independently selected from a single bond or phenylene; Ar 1 -Ar 3 each independently selected from one of the following groups of substituted or unsubstituted phenyl, biphenyl, fluorenyl, spirofluorenyl, carbazolyl, terphenyl, naphthyl, phenanthryl, benzophenanthryl, benzothiophenyl, benzofuranyl, quaterphenyl, indenyl, benzo-fluorenyl, indenofluorenyl, fluoranthenyl, triphenylenyl, pyrenyl, perylenyl, chrysenyl, naphthacene, tetracene, diphenylchalcogendioyl, diphenylselenophenedioyl, or diphenyldi-oxadioyl; R 2 one selected from the group consisting of phenyl, naphthyl, anthryl, and biphenyl; ​ when the above groups bear substituents, said substituents are each independently selected from halogen, cyano, Ci-C6alkyl or cycloalkyl, C2-C6alkenyl or cycloalkenyl, Ci-C6alkoxy, phenyl. 10 Ci-C6alkyl or cycloalkyl, C2-C6alkenyl or cycloalkenyl, Ci-C6alkoxy, phenyl. ​ ； ； ； ； ； ； ； ； ； 。 ​ 4. An organic electroluminescent device comprising a first electrode, a second electrode and one or more organic layers interposed between said first and second electrodes, characterized in that ​

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