Biphenyl dinaphthalene substituted arylamine compound and application thereof

Abstract

The invention relates to the technical field of organic light-emitting display, in particular to a biphenyl-naphthalene substituted arylamine compound and application, and provides a compound shown in a formula (I) which can be used for hole transport materials. The compound has a parent structure of biphenyl and naphthalene substituted arylamine, is high in bond energy between atoms, has good thermal stability, is beneficial to solid-state accumulation between molecules, is high in hole transition capability, and can effectively reduce the voltage of a device and prolong the service life of the material when being used as a hole transport material. The invention also provides an organic electroluminescent device and a display device containing the compound shown in the formula (I).

Description

Technical Field

[0001] This invention relates to the field of organic light-emitting display technology, specifically to a biphenyl-naphthalene-substituted aromatic amine compound and its applications. Background Technology

[0002] Electroluminescence (EL) refers to the phenomenon where luminescent materials emit light when excited by an electric field and current. It is a process that directly converts electrical energy into light energy. Organic electroluminescent displays (OLEDs) possess a series of advantages, including self-illumination, low-voltage DC drive, all-solid-state operation, wide viewing angle, light weight, and simple composition and manufacturing process. Compared to liquid crystal displays (LCDs), OLEDs do not require a backlight, have a wider viewing angle, lower power consumption, and a response speed up to 1000 times faster than LCDs, while their manufacturing cost is lower than that of LCDs with equivalent resolution. Therefore, organic electroluminescent devices have a very broad application prospect.

[0003] With the continuous advancement of OLED technology in the fields of lighting and display, people are paying more attention to the research of high-efficiency organic materials that affect the performance of OLED devices. A high-efficiency, long-life organic electroluminescent device is usually the result of the optimized combination of device structure and various organic materials, which provides chemists with great opportunities and challenges to design and develop functional materials with various structures.

[0004] Compared to inorganic light-emitting materials, organic electroluminescent materials have many advantages, such as: good processing performance, allowing for film deposition on any substrate via evaporation or spin coating, enabling flexible and large-area displays; and the ability to adjust the optical, electrical, and stability properties of the material by altering its molecular structure, providing a wide range of material choices. The most common OLED device structures typically include the following types of organic materials: hole injection materials, hole transport materials, electron transport materials, and various colored luminescent materials (dyes or doped guest materials) and corresponding host materials. Among these, hole transport materials, as an important functional material, directly affect hole mobility and ultimately the luminous efficiency of the OLED. However, currently used hole transport materials in OLEDs achieve relatively low hole mobility, poor energy level matching with adjacent layers, and cannot simultaneously achieve both efficiency and lifetime, severely restricting the display functionality and development of OLED display devices. Summary of the Invention

[0005] In view of the shortcomings of the prior art, the purpose of this invention is to provide a biphenyl-naphthalene-substituted aromatic amine compound and its application, which can improve the working efficiency and extend the service life of organic electroluminescent devices.

[0006] To achieve the above objectives, the following technical solution is adopted:

[0007] The first aspect of this invention aims to provide a biphenyl-naphthalene-substituted aromatic amine compound having a structure as shown in formula (I):

[0008]

[0009] R 1 R 2 They are independently selected from C1-C4 alkanes, C6-C 30 Aromatic group, C3-C 30 heteroaryl, R 1 R 2 They can be connected to form a ring;

[0010] R 3 -R 6 They are independently selected from hydrogen, deuterium, C1-C4 alkanes, and C5-C6 alkanes. 10 Cycloalkanes, C6-C 30 Aromatic group, C3-C 30 The heteroaryl group can be linked with adjacent R substituents to form a ring;

[0011] R 7 R 8 They are independently selected from hydrogen, deuterium, and C1-C. 20 Alkanes, C5-C 20 Cycloalkanes, C6-C 30 Aromatic group, C3-C 30 heteroaryl groups, and R 7 R 8 The spaces can be connected to form a ring;

[0012] L is selected from chemical bonds, C6-C 30 Aromatic group, C3-C 30 heteroaryl groups;

[0013] Ar is selected from C6-C 30 Aromatic group, C3-C 30 heteroaryl groups;

[0014] The heteroatoms on the heteroaryl group are each independently selected from O, S, and N;

[0015] The hydrogen atoms on the aromatic and heteroaryl groups can each be independently substituted by Ra, wherein Ra is independently selected from deuterium, halogen, nitro, cyano, C1-C4 alkyl, C5-C 20 Cycloalkyl, phenyl, biphenyl, terphenyl, naphthyl.

[0016] Preferably, the R 1 R 2They are independently selected from C1-C4 alkanes, C6-C 30 Aromatic group, C3-C 30 heteroaryl groups, and R 1 R 2 At least one of them is selected from C 12 -C 20 Aromatic or heteroaryl, R 1 R 2 They can be connected to form a ring.

[0017] More preferably, R 1 R 2 The following groups, independently selected from methyl, ethyl, isopropyl, unsubstituted or substituted by Ra: phenyl, biphenyl, terphenyl, naphthyl, phenanthrene, triphenylene, fluorenyl, benzofuranyl, dibenzofuranyl, benzothiophene, dibenzothiophene, 9,9-dimethylfluorenyl, spirofluorenyl, aromatic amino, carbazole.

[0018] Preferably, R 3 -R 6 The following groups are selected independently from hydrogen, deuterium, C1-C4 alkanes, unsubstituted or substituted by Ra: phenyl, biphenyl, terphenyl, naphthyl, phenanthrene, triphenylene, fluorenyl, benzofuranyl, dibenzofuranyl, benzothiophene, dibenzothiophene, 9,9-dimethylfluorenyl, spirofluorenyl, aromatic amino, carbazole;

[0019] Preferably, R 7 -R 8 The groups are independently selected from hydrogen, deuterium, methyl, ethyl, isopropyl, tert-butyl, cyclopentyl, cyclohexyl, adamantyl, and the following groups, either unsubstituted or substituted with Ra: phenyl, biphenyl, terphenyl, naphthyl, phenanthrene, triphenylene, fluorenyl, benzofuranyl, dibenzofuranyl, benzothiophene, dibenzothiophene, 9,9-dimethylfluorenyl, spirofluorenyl, aromatic amino, and carbazole.

[0020] Preferably, Ar is selected from the following groups, either unsubstituted or substituted by Ra: phenyl, biphenyl, terphenyl, naphthyl, phenanthrene, triphenylene, fluorenyl, benzofuranyl, dibenzofuranyl, benzothiophene, dibenzothiophene, 9,9-dimethylfluorenyl, spirofluorenyl, aromatic amino, carbazole.

[0021] Preferably, L is selected from the following groups that are chemically bonded, unsubstituted, or substituted by Ra: phenyl, biphenyl, terphenyl, naphthyl, phenanthrene, triphenylene, fluorenyl, benzofuranyl, dibenzofuranyl, benzothiophene, dibenzothiophene, 9,9-dimethylfluorenyl, spirofluorenyl, aromatic amino, carbazole.

[0022] More preferably, the biphenyl-naphthalene-substituted aromatic amine compound is selected from the compounds shown in A1 to A35:

[0023]

[0024]

[0025]

[0026] A second aspect of the present invention aims to provide a hole transport material comprising at least one of the biphenyl-naphthyl-substituted aromatic amine compounds provided in the first aspect of the present invention.

[0027] A third aspect of the present invention aims to provide an organic electroluminescent device comprising at least one of the hole transport materials provided in the second aspect of the present invention.

[0028] A fourth aspect of the present invention is to provide a display device comprising the organic electroluminescent device provided in the third aspect of the present invention.

[0029] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0030] The compound disclosed in this invention has a parent structure of biphenyl-naphthalene-substituted aromatic amines, with high interatomic bond energy, good thermal stability, and is conducive to solid-state stacking between molecules. It has strong hole transition capability and can be used as a hole transport layer material to effectively reduce device voltage and improve material lifetime. At the same time, the naphthyl fragment has a certain steric hindrance protection effect on the aromatic amine center, reducing the HOMO energy level of the material and protecting the active center, thus improving lifetime.

[0031] The compounds described in this invention, when applied in hole transport layers, have suitable energy level levels with adjacent layers, which is beneficial for hole injection and migration, effectively reducing the driving voltage. At the same time, the high hole migration rate enables good luminous efficiency in devices. The compounds of this invention have long conjugated planar chains, which is beneficial for molecular stacking and can increase the glass transition temperature of the material, exhibiting good thermodynamic stability and long lifetime in devices.

[0032] Meanwhile, the preparation process of the derivatives described in this invention is simple and easy to implement, the raw materials are readily available, and it is suitable for industrial production. Attached Figure Description

[0033] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only one embodiment of the present invention. For those skilled in the art, other embodiments can be obtained based on these drawings.

[0034] Figure 1 This is a schematic diagram of a typical organic electroluminescent device. Reference numerals: 1. Substrate; 2. Reflective anode electrode; 3. Hole injection layer; 4. Hole transport layer; 5. Emitting layer; 6. Electron transport layer; 7. Electron injection layer; 8. Cathode electrode. Detailed Implementation

[0035] The technical solutions of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are merely some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention are within the scope of protection of the present invention.

[0036] In this invention, there are no particular restrictions on the type and structure of organic electroluminescent devices, as long as the hole transport material provided by this invention can be used.

[0037] The organic electroluminescent device of the present invention can be a top-emitting device, for example, comprising an anode, a hole injection layer, a hole transport layer, an emitting layer, an electron transport layer, an electron injection layer, and a transparent or semi-transparent cathode in sequence on a substrate.

[0038] The organic electroluminescent device of the present invention can also be a bottom-emitting device, for example, comprising a transparent or semi-transparent anode, a hole injection layer, a hole transport layer, an emitting layer, an electron transport layer, an electron injection layer and a cathode structure in sequence on a substrate.

[0039] The organic electroluminescent device of the present invention can also be a light-emitting device with a dual-sided light-emitting structure, for example, comprising a transparent or semi-transparent anode, a hole injection layer, a hole transport layer, a light-emitting layer, an electron transport layer, an electron injection layer and a transparent or semi-transparent cathode structure in sequence on a substrate.

[0040] In the organic electroluminescent device of the present invention, except for the hole transport layer which contains the hole transport material provided by the present invention, other layers may use any material used for the layers in the prior art.

[0041] Figure 1 A schematic diagram of a typical organic electroluminescent device is shown, in which, from bottom to top, a substrate 1, a reflective anode electrode 2, a hole injection layer 3, a hole transport layer 4, a light-emitting layer 5, an electron transport layer 6, an electron injection layer 7, and a cathode electrode 8 are arranged sequentially.

[0042] Understandable. Figure 1The diagram only schematically illustrates the structure of a typical organic electroluminescent device. This invention is not limited to this structure, and the hole transport material of this invention can be used in any type of organic electroluminescent device. For example, organic electroluminescent devices may also include an electron blocking layer, a hole blocking layer, a light extraction layer, etc. In practical applications, these layers can be added or omitted depending on the specific circumstances.

[0043] For convenience, the following references Figure 1 The organic electroluminescent device of the present invention will be described, but this does not imply any limitation on the scope of protection of the present invention. It is understood that all organic electroluminescent devices capable of using the hole transport material of the present invention are within the scope of protection of the present invention.

[0044] In this invention, the substrate 1 is not particularly limited and can be a conventional substrate used in organic electroluminescent devices in the prior art, such as glass, polymer materials, and glass and polymer materials with TFT components.

[0045] In this invention, the material of the reflective anode electrode 2 is not particularly limited. It can be selected from transparent conductive materials known in the prior art such as indium tin oxide (ITO), indium zinc oxide (IZO), tin dioxide (SnO2), zinc oxide (ZnO), and low-temperature polycrystalline silicon (LTPS). It can also be metallic materials such as silver and its alloys, aluminum and its alloys, organic conductive materials such as PEDOT (poly(3,4-ethylenedioxythiophene)), or multilayer structures of the above materials.

[0046] In this invention, the material of the hole injection layer 3 is not particularly limited, and hole injection materials known in the art or hole transport materials provided by this invention can be selected as hole injection materials.

[0047] For example, the material of the hole injection layer 3 may be selected from at least one of the following HT-1 to HT-31 compounds:

[0048]

[0049]

[0050] In this invention, the hole injection layer 3 may further include a p-type dopant. The type of p-type dopant is not particularly limited, and various p-type dopants known in the art can be used. For example, the p-type dopant may be selected from at least one of the following compounds:

[0051]

[0052] In this invention, the amount of p-type dopant used is not particularly limited and can be any amount known to those skilled in the art.

[0053] In this invention, the hole transport layer 4 comprises at least one of the hole transport materials of this invention. The hole transport layer 4 may also comprise any combination of at least one of the hole transport materials of this invention and known hole transport materials. Currently known hole transport materials may be selected from at least one of the compounds HT-1 to HT-31 described above, but are not limited to the compounds listed above.

[0054] In this invention, the luminescent material of the luminescent layer 5 is not particularly limited, and any luminescent material known to those skilled in the art can be used. For example, the luminescent material may comprise a host material and a guest material. For instance, it may be selected from, but is not limited to, at least one of the following RH-1 to RH-13 compounds:

[0055]

[0056]

[0057] The host material for the luminescent layer 5 can also be at least one of the green luminescent layer host materials known in the art. For example, it can be at least one of the following GPH-1 to GPH-80 compounds:

[0058]

[0059]

[0060]

[0061] The host material for the luminescent layer can also be at least one of the blue luminescent layer host materials known in the art. For example, it can be at least one of the following compounds, but not limited to: BH-1 to BH-10.

[0062]

[0063] The luminescent layer guest material can be a red luminescent layer guest material, for example, it can be selected from, but is not limited to, at least one of the following RPD-1 to RPD-28 compounds:

[0064]

[0065]

[0066] The luminescent layer guest material can be a green luminescent layer guest material, for example, it can be selected from at least one of the following GD01 to GD04 compounds:

[0067]

[0068] The luminescent layer guest material can be a blue luminescent layer guest material, for example, it can be selected from, but is not limited to, at least one of the following BD-1 to BD-9 compounds:

[0069]

[0070]

[0071] In this invention, the material of the electron transport layer 6 is not particularly limited and can be made of electron transport materials known in the art. For example, the material of the electron transport layer 6 can be selected from at least one of the following ET-1 to ET-57 compounds:

[0072]

[0073]

[0074]

[0075] In this invention, the electron transport layer 6 may further include an n-type dopant. The type of n-type dopant is not particularly limited, and various n-type dopants known in the art can be used. For example, the n-type dopant may be a compound represented by the following formula:

[0076]

[0077] In this invention, the amount of the n-type dopant is not particularly limited and can be any amount known to those skilled in the art.

[0078] In this invention, the material of the electron injection layer 7 is not particularly limited, and electron injection materials known in the art can be used, such as, but not limited to, at least one of the following materials in the prior art: LiQ, LiF, NaCl, CsF, Li2O, Cs2CO3, BaO, Na, Li, Ca, etc.

[0079] In this invention, the material of the cathode electrode 8 is not particularly limited. For example, it can be selected from, but is not limited to, magnesium-silver mixtures, LiF / Al, ITO, Al and other metals, metal mixtures, oxides and the like.

[0080] The present invention provides a display device comprising the organic electroluminescent device provided by the present invention. The display device includes, but is not limited to, monitors, televisions, tablet computers, and mobile communication terminals.

[0081] There are no particular limitations on the method for preparing the organic electroluminescent device of the present invention, and any method known in the art can be used. For example, the present invention can be prepared by the following method:

[0082] (1) Clean the reflective anode electrode 2 on the substrate 1 of the top-emitting OLED device. In the cleaning machine, the electrode is cleaned by chemical washing, water washing, brushing, high-pressure water washing, air knife and other steps, and then heated.

[0083] (2) Hole injection material is vacuum-deposited on the reflective anode electrode 2 as a hole injection layer 3;

[0084] (3) Hole transport material is vacuum-deposited on hole injection layer 3 as hole transport layer 4;

[0085] (4) A light-emitting layer 5 is vacuum-deposited on the hole transport layer 4, the light-emitting layer 5 containing a host material and a guest material;

[0086] (5) Electron transport material is vacuum-deposited on the light-emitting layer 5 as electron transport layer 6;

[0087] (6) Vacuum evaporation of electron injection material on electron transport layer 6 to form electron injection layer 7. The electron injection material is selected from one or a combination of several materials such as LiQ, LiF, NaCl, CsF, Li2O, Cs2CO3, BaO, Na, Li, and Ca.

[0088] (7) Vacuum evaporation of cathode material on electron injection layer 7 as cathode electrode 8.

[0089] The above description only illustrates the structure and fabrication method of a typical organic electroluminescent device. It should be understood that the present invention is not limited to this structure. The hole transport material of the present invention can be used in organic electroluminescent devices of any structure, and the organic electroluminescent device can be fabricated using any fabrication method known in the art.

[0090] The synthesis method of the compounds of the present invention is not particularly limited, and any method known to those skilled in the art can be used for synthesis. The following examples illustrate the synthesis process of the compounds of the present invention.

[0091] Synthesis Example 1: Synthesis of Compound A2

[0092]

[0093] 100 mmol of 2,6-dibromonaphthalene, 100 mmol of 4-biphenylboronic acid, 41.4 g of potassium carbonate (300 mmol), 800 mL of tetrahydrofuran (THF), and 200 mL of water were added to a reaction flask, along with 1 mol% of tetra(triphenylphosphine)palladium (Pd(PPh3)4). The reaction was carried out at 60 °C for 12 h. After the reaction was completed, the reaction was stopped, and the reactants were cooled to room temperature. Water was added, and the organic phase was concentrated to obtain a white solid. The solid was filtered, washed with water, and purified by recrystallization from toluene to obtain a white powder M1. The amount of Pd(PPh3)4 added was 1 mol% of 2,6-dibromonaphthalene.

[0094] 100 mmol of 2-amino-9,9-dimethylfluorene, 100 mmol of M1, 28.83 g of sodium tert-butoxide (300 mmol), and 800 mL of xylene were added to a reaction flask, along with 1 mol% of bis(dba)2 dibenzylacetone palladium (Pd(dba)2). The reaction was carried out at 120 °C for 12 h. After the reaction was completed, the reaction was stopped, and the reactants were cooled to room temperature. Water was added, the mixture was filtered, washed with water, and the resulting solid was purified by recrystallization from toluene to obtain a white powder M2. The amount of Pd(dba)2 added was 1 mol% of 2-amino-9,9-dimethylfluorene.

[0095] 100 mmol of M2, 100 mmol of bromobenzene, 28.83 g of sodium tert-butoxide (300 mmol), and 800 mL of xylene were added to a reaction flask, along with 1 mol% of bis(dba)2-dibenzylacetone palladium (Pd(dba)2). The reaction was carried out at 120 °C for 12 h. After the reaction was completed, the reaction was stopped, and the reactants were cooled to room temperature. Water was added, the mixture was filtered, washed with water, and the resulting solid was purified by recrystallization from toluene to obtain a white powder A2. The amount of Pd(dba)2 added was 1 mol% of M2.

[0096] 1 H NMR(400MHz,Chloroform)δ7.92(d,J=7.2Hz,1H),7.86(d,J=8.0Hz,1H),7.82(d,J=7.2Hz,1H),7.75(d,J=8.0Hz,2H),7.58-7.45(m,5H) ,7.40(t,J=6.8Hz,2H),7.35(d,J=7.2Hz,3H),7.28-7.21(m,6H),7.17(s,1H),7.10(t,J=7.6Hz,4H),7.00(t,J=7.2Hz,1H),1.69(s,6H).

[0097] Synthesis Example 2: Synthesis of Compound A11

[0098]

[0099] 100 mmol of 2,6-dibromonaphthalene, 100 mmol of 4-biphenylboronic acid, 41.4 g of potassium carbonate (300 mmol), 800 mL of tetrahydrofuran (THF), and 200 mL of water were added to a reaction flask, along with 1 mol% of tetra(triphenylphosphine)palladium (Pd(PPh3)4). The reaction was carried out at 60 °C for 12 h. After the reaction was completed, the reaction was stopped, and the reactants were cooled to room temperature. Water was added, and the organic phase was concentrated to obtain a white solid. The solid was filtered, washed with water, and purified by recrystallization from toluene to obtain a white powder M1. The amount of Pd(PPh3)4 added was 1 mol% of 2,6-dibromonaphthalene.

[0100] 100 mmol of 2-amino-9,9-dimethylfluorene, 100 mmol of M1, 28.83 g of sodium tert-butoxide (300 mmol), and 800 mL of xylene were added to a reaction flask, along with 1 mol% of bis(dba)2 dibenzylacetone palladium (Pd(dba)2). The reaction was carried out at 120 °C for 12 h. After the reaction was completed, the reaction was stopped, and the reactants were cooled to room temperature. Water was added, the mixture was filtered, washed with water, and the resulting solid was purified by recrystallization from toluene to obtain a white powder M2. The amount of Pd(dba)2 added was 1 mol% of 2-amino-9,9-dimethylfluorene.

[0101] 100 mmol of 2-iodo-3-bromophenol, 100 mmol of 4-chloro-2-fluorophenylboronic acid, 41.4 g of potassium carbonate (300 mmol), 800 mL of tetrahydrofuran (THF), and 200 mL of water were added to a reaction flask, along with 1 mol% of tetra(triphenylphosphine)palladium (Pd(PPh3)4). The reaction was carried out at 60 °C for 12 h. After the reaction was completed, the reaction was stopped, and the reactants were cooled to room temperature. Water was added, and the organic phase was concentrated to obtain a white solid. The solid was filtered, washed with water, and purified by recrystallization from toluene to obtain a white powder M3. The amount of Pd(PPh3)4 added was 1 mol% of 2-iodo-3-bromophenol.

[0102] 100 mmol of M3, 41.4 g of potassium carbonate (300 mmol), and 800 mL of N,N-dimethylformamide (DMF) were added to a reaction flask, and the mixture was reacted at 120 °C for 12 h. After the reaction was completed, the reaction was stopped, and the reactants were cooled to room temperature. Water was added, and the organic phase was concentrated to obtain a white solid. The solid was filtered, washed with water, and then purified by recrystallization from toluene to obtain a white powder, M4.

[0103] 100 mmol of M4, 100 mmol of phenylboronic acid, 41.4 g of potassium carbonate (300 mmol), 800 mL of tetrahydrofuran (THF), and 200 mL of water were added to a reaction flask, along with 1 mol% of tetra(triphenylphosphine)palladium (Pd(PPh3)4). The reaction was carried out at 60 °C for 12 h. After the reaction was completed, the reaction was stopped, and the reactants were cooled to room temperature. Water was added, and the organic phase was concentrated to obtain a white solid. The solid was filtered, washed with water, and then purified by recrystallization from toluene to obtain a white powder, M5. The amount of Pd(PPh3)4 added was 1 mol% of M4.

[0104] 100 mmol of M2, 100 mmol of M5, 28.83 g of sodium tert-butoxide (300 mmol), and 800 mL of xylene were added to a reaction flask, along with 1 mol% of bis(dba)2-dibenzylacetone palladium (Pd(dba)2). The reaction was carried out at 120 °C for 12 h. After the reaction was completed, the reaction was stopped, and the reactants were cooled to room temperature. Water was added, the mixture was filtered, washed with water, and the resulting solid was purified by recrystallization from toluene to obtain a white powder, Al1. The amount of Pd(dba)2 added was 1 mol% of M2.

[0105] 1 H NMR (400MHz, Chloroform) δ8.03 (s, 1H), 7.94-7.76 (m, 7H), 7.60-7.51 (m, 7H), 7.46 (d, J = 7.6Hz, 4H),7.42-7.35(m,5H),7.32(d,J=7.2Hz,2H),7.26-7.20(m,4H),7.17-7.08(m,3H),1.69(s,6H).

[0106] Synthesis Example 3: Synthesis of Compound A20

[0107]

[0108] 100 mmol of 2-bromofluorenone and 200 mL of THF were added to a reaction flask. 100 mmol of methyl magnesium bromide was added dropwise at 0 °C. After the addition was complete, the reaction was maintained at 0 °C for 1 h, then increased to room temperature and reacted for 12 h. After the reaction was complete, water was added, the organic phase was separated, and the mixture was concentrated to obtain intermediate M1.

[0109] Add 100 mmol of M1 and 200 mL of benzene to a reaction flask. At 0 °C, add 20 mL of trifluoromethanesulfonic acid dropwise. After the addition is complete, control the temperature and react for 1 h, then raise the temperature to reflux and react for 12 h. After the reaction is complete, add water, separate the organic phase, concentrate, and obtain intermediate M2.

[0110] 100 mmol of aniline, 100 mmol of M2, 28.83 g of sodium tert-butoxide (300 mmol), and 800 mL of xylene were added to a reaction flask, along with 1 mol% of bis(dba)2-dibenzylacetone palladium (Pd(dba)2). The reaction was carried out at 120 °C for 12 h. After the reaction was completed, the reaction was stopped, and the reactants were cooled to room temperature. Water was added, the mixture was filtered, washed with water, and the resulting solid was purified by recrystallization from toluene to obtain a white powder M3. The amount of Pd(dba)2 added was 1 mol% of aniline.

[0111] 100 mmol of 5-bromo-2-chloro-iodobenzene, 100 mmol of phenylboronic acid, 41.4 g of potassium carbonate (300 mmol), 800 mL of tetrahydrofuran (THF), and 200 mL of water were added to a reaction flask, along with 1 mol% of tetra(triphenylphosphine)palladium (Pd(PPh3)4). The reaction was carried out at 60 °C for 12 h. After the reaction was completed, the reaction was stopped, and the reactants were cooled to room temperature. Water was added, and the organic phase was concentrated to obtain a white solid. The solid was filtered, washed with water, and then purified by recrystallization from toluene to obtain a white powder M4. The amount of Pd(PPh3)4 added was 1 mol% of 5-bromo-2-chloro-iodobenzene.

[0112] 100 mmol of M4, 100 mmol of phenylboronic acid, 41.4 g of potassium carbonate (300 mmol), 800 mL of tetrahydrofuran (THF), and 200 mL of water were added to a reaction flask, along with 1 mol% of tetra(triphenylphosphine)palladium (Pd(PPh3)4). The reaction was carried out at 60 °C for 12 h. After the reaction was completed, the reaction was stopped, and the reactants were cooled to room temperature. Water was added, and the organic phase was concentrated to obtain a white solid. The solid was filtered, washed with water, and then purified by recrystallization from toluene to obtain a white powder, M5. The amount of Pd(PPh3)4 added was 1 mol% of M4.

[0113] 100 mmol of M5, 100 mmol of pinacol diborate, 28.83 g of sodium tert-butoxide (300 mmol), and 800 mL of xylene were added to a reaction flask, along with 1 mol% of palladium dibenzylacetone (Pd(dba)2). The reaction was carried out at 120 °C for 12 h. After the reaction was completed, the reaction was stopped, and the reactants were cooled to room temperature. Water was added, the mixture was filtered, washed with water, and the resulting solid was purified by recrystallization from toluene to obtain a white powder, M6. The amount of Pd(dba)2 added was 1 mol% of M5.

[0114] 100 mmol of M6, 100 mmol of 2,6-dibromonaphthalene, 41.4 g of potassium carbonate (300 mmol), 800 mL of tetrahydrofuran (THF), and 200 mL of water were added to a reaction flask, along with 1 mol% of tetra(triphenylphosphine)palladium (Pd(PPh3)4). The reaction was carried out at 60 °C for 12 h. After the reaction was completed, the reaction was stopped, and the reactants were cooled to room temperature. Water was added, and the organic phase was concentrated to obtain a white solid. The solid was filtered, washed with water, and purified by recrystallization from toluene to obtain a white powder, M7. The amount of Pd(PPh3)4 added was 1 mol% of M6.

[0115] 100 mmol of M3, 100 mmol of M7, 28.83 g of sodium tert-butoxide (300 mmol), and 800 mL of xylene were added to a reaction flask, along with 1 mol% of bis(dba)2-dibenzylacetone palladium (Pd(dba)2). The reaction was carried out at 120 °C for 12 h. After the reaction was completed, the reaction was stopped, and the reactants were cooled to room temperature. Water was added, the mixture was filtered, washed with water, and the resulting solid was purified by recrystallization from toluene to obtain a white powder, A20. The amount of Pd(dba) added was 1 mol% of M3.

[0116] 1 H NMR (400MHz, Chloroform) δ8.16(d,J=8.4Hz,2H),7.90(d,J=7.2Hz,1H),7.86(d,J=8.0Hz,1H),7.82(d,J=7.2Hz,2H),7.77(d,J=7.6Hz,3H) ,7.62-7.54(m,3H),7.48-7.40(m,7H),7.37-7.22(m,11H),7.20(d,J=8.0Hz,2H),7.10(t,J=7.6Hz,3H),7.00(t,J=7.2Hz,1H),2.28(s,3H).

[0117] Synthesis Example 4: Synthesis of Compound A22

[0118]

[0119] 100 mmol of 2,6-dibromonaphthalene, 100 mmol of 4-biphenylboronic acid, 41.4 g of potassium carbonate (300 mmol), 800 mL of tetrahydrofuran (THF), and 200 mL of water were added to a reaction flask, along with 1 mol% of tetra(triphenylphosphine)palladium (Pd(PPh3)4). The reaction was carried out at 60 °C for 12 h. After the reaction was completed, the reaction was stopped, and the reactants were cooled to room temperature. Water was added, and the organic phase was concentrated to obtain a white solid. The solid was filtered, washed with water, and purified by recrystallization from toluene to obtain a white powder M1. The amount of Pd(PPh3)4 added was 1 mol% of 2,6-dibromonaphthalene.

[0120] 100 mmol of 2-amino-9,9-dimethylfluorene, 100 mmol of M1, 28.83 g of sodium tert-butoxide (300 mmol), and 800 mL of xylene were added to a reaction flask, along with 1 mol% of bis(dba)2 dibenzylacetone palladium (Pd(dba)2). The reaction was carried out at 120 °C for 12 h. After the reaction was completed, the reaction was stopped, and the reactants were cooled to room temperature. Water was added, the mixture was filtered, washed with water, and the resulting solid was purified by recrystallization from toluene to obtain a white powder M2. The amount of Pd(dba)2 added was 1 mol% of 2-amino-9,9-dimethylfluorene.

[0121] 100 mmol of pentafluorobromobenzene, 100 mmol of 4-chlorophenylboronic acid, 41.4 g of potassium carbonate (300 mmol), 800 mL of tetrahydrofuran (THF), and 200 mL of water were added to a reaction flask, along with 1 mol% of tetra(triphenylphosphine)palladium (Pd(PPh3)4). The reaction was carried out at 60 °C for 12 h. After the reaction was complete, the reaction was stopped, and the reactants were cooled to room temperature. Water was added, and the organic phase was concentrated to obtain a white solid. The solid was filtered, washed with water, and then purified by recrystallization from toluene to obtain a white powder M3. The amount of Pd(PPh3)4 added was 1 mol% of the pentafluorobromobenzene.

[0122] 100 mmol of M2, 100 mmol of M3, 28.83 g of sodium tert-butoxide (300 mmol), and 800 mL of xylene were added to a reaction flask, along with 1 mol% of palladium dibenzylacetone (Pd(dba)2). The reaction was carried out at 120 °C for 12 h. After the reaction was complete, the reaction was stopped, and the reactants were cooled to room temperature. Water was added, the mixture was filtered, washed with water, and the resulting solid was purified by recrystallization from toluene to obtain a white powder, A22. The amount of Pd(dba)2 added was 1 mol% of M2.

[0123] 1H NMR (400MHz, Chloroform) δ7.92(d,J=7.2Hz,1H),7.86(d,J=8.0Hz,1H),7.82(d,J=7.2Hz,1H),7.76(d,J=7.6Hz,2 H),7.58-7.50(m,5H),7.46-7.40(m,3H),7.38-7.28(m,6H),7.26-7.19(m,6H),7.10(d,J=7.2Hz,1H),1.69(s,6H).

[0124] Other compounds of the present invention can be synthesized by selecting suitable raw materials according to the ideas of the above-described synthesis examples 1-4, or by selecting any other suitable methods and raw materials.

[0125] Example 1

[0126] The glass substrate 1 coated with the ITO transparent conductive layer was 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 all moisture was removed, cleaned with ultraviolet light and ozone, and bombarded with a low-energy cation beam.

[0127] The glass substrate 1 with the above-mentioned reflective anode electrode 2 is placed in a vacuum chamber and evacuated to less than 10-5 Torr. HT-27 is vacuum-deposited on the above-mentioned reflective anode electrode 2 film as a hole injection layer 3. The deposition rate is 0.1 nm / s and the deposition film thickness is 10 nm.

[0128] A2 material was vacuum-deposited on top of the hole injection layer 3 as the hole transport layer 4, with a deposition rate of 0.1 nm / s and a film thickness of 80 nm.

[0129] A light-emitting layer 5 is vacuum-deposited on top of the hole transport layer 4. The light-emitting layer 5 includes a host material BH-6 and a dye material BD-3. The deposition is carried out using a multi-source co-evaporation method. The deposition rate of the host material BH-6 is adjusted to 0.1 nm / s, the deposition rate of the dye BD-3 is 3% of the deposition rate of the host material, and the total deposition film thickness is 20 nm.

[0130] An electron transport layer 6 is vacuum-deposited on top of the light-emitting layer 5. ET-27 is selected as the electron transport material, with a deposition rate of 0.1 nm / s and a deposition film thickness of 30 nm.

[0131] A 0.5 nm thick LiF layer was vacuum-deposited on the electron transport layer (ETL) 6 as the electron injection layer 7 at a deposition rate of 0.1 nm / s.

[0132] Finally, an aluminum layer with a thickness of 150 nm is deposited on the electron injection layer 7 as the cathode electrode 8 of the organic electroluminescent device, with a deposition rate of 0.1 nm / s.

[0133] Examples 2-4

[0134] Except for replacing A2 with A11, A20, and A22 respectively, the rest is the same as in Example 1.

[0135] Comparative Example 1

[0136] Except for replacing A2 with HT-27, everything else is the same as in Example 1.

[0137] Comparative Example 2

[0138] Except for replacing A2 with R, everything else is the same as in Example 1.

[0139]

[0140] The organic electroluminescent devices prepared by the above process were subjected to the following performance measurements:

[0141] Under the same brightness, the driving voltage and current efficiency, as well as the lifetime of the organic electroluminescent devices prepared in the examples and comparative examples, were measured using a digital source meter and a luminance meter. Specifically, the voltage was increased at a rate of 0.1V per second, and the measurement was performed when the brightness of the organic electroluminescent device reached 1000 cd / m². 2 The voltage at that time is the driving voltage, and the current density at that time is measured simultaneously; the ratio of brightness to current density is the current efficiency; the life test of LT95 is as follows: using a luminance meter at 1000 cd / m² 2 At a constant current, the brightness of the organic electroluminescent device decreased to 950 cd / m² under the specified brightness. 2 The time units are hours, and the results are shown in Table 1.

[0142] Table 1. Performance results of organic electroluminescent devices

[0143]

[0144] As can be seen from the data in the table above, the compound prepared by this invention can be used as a hole transport material for organic electroluminescent devices, which can effectively reduce the driving voltage, improve the current efficiency, and extend the device life. It is a high-performance hole transport material.

[0145] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention are included within the scope of protection of the present invention.

Claims

1. A biphenyl-naphthalene-substituted aromatic amine compound, characterized in that, It has a structure as shown in equation (I): R 1 R 2 They are independently selected from C1-C4 alkanes, C6-C 30 Aromatic group, C3-C 30 heteroaryl, R 1 R 2 They can be connected to form a ring; R 3 -R 6 They are independently selected from hydrogen, deuterium, C1-C4 alkanes, and C5-C6 alkanes. 10 Cycloalkanes, C6-C 30 Aromatic group, C3-C 30 The heteroaryl group can be linked with adjacent R substituents to form a ring; R 7 R 8 They are independently selected from hydrogen, deuterium, and C1-C. 20 Alkanes, C5-C 20 Cycloalkanes, C6-C 30 Aromatic group, C3-C 30 heteroaryl groups, and R 7 R 8 The spaces can be connected to form a ring; L is selected from chemical bonds, C6-C 30 Aromatic group, C3-C 30 heteroaryl groups; Ar is selected from C6-C 30 Aromatic group, C3-C 30 heteroaryl groups; The heteroatoms on the heteroaryl group are each independently selected from O, S, and N; The hydrogen atoms on the aromatic and heteroaryl groups can each be independently substituted by Ra, wherein Ra is independently selected from deuterium, halogen, nitro, cyano, C1-C4 alkyl, C5-C 20 Cycloalkyl, phenyl, biphenyl, terphenyl, naphthyl.

2. The biphenyl-naphthalene-substituted aromatic amine compound according to claim 1, characterized in that, The R 1 R 2 They are independently selected from C1-C4 alkanes, C6-C 30 Aromatic group, C3-C 30 heteroaryl groups, and R 1 R 2 At least one of them is selected from C 12 -C 20 Aromatic or heteroaryl, R 1 R 2 They can be connected to form a ring.

3. The biphenyl-naphthalene-substituted aromatic amine compound according to claim 1, characterized in that, R 1 R 2 The following groups, independently selected from methyl, ethyl, isopropyl, unsubstituted or substituted by Ra: phenyl, biphenyl, terphenyl, naphthyl, phenanthrene, triphenylene, fluorenyl, benzofuranyl, dibenzofuranyl, benzothiophene, dibenzothiophene, 9,9-dimethylfluorenyl, spirofluorenyl, aromatic amino, carbazole.

4. The biphenyl-naphthalene-substituted aromatic amine compound according to claim 1, characterized in that, R 3 -R 6 The following groups are selected independently from hydrogen, deuterium, C1-C4 alkanes, unsubstituted or substituted by Ra: phenyl, biphenyl, terphenyl, naphthyl, phenanthrene, triphenylene, fluorenyl, benzofuranyl, dibenzofuranyl, benzothiophene, dibenzothiophene, 9,9-dimethylfluorenyl, spirofluorenyl, aromatic amino, carbazole; R 7 -R 8 The groups are independently selected from hydrogen, deuterium, methyl, ethyl, isopropyl, tert-butyl, cyclopentyl, cyclohexyl, adamantyl, and the following groups, either unsubstituted or substituted with Ra: phenyl, biphenyl, terphenyl, naphthyl, phenanthrene, triphenylene, fluorenyl, benzofuranyl, dibenzofuranyl, benzothiophene, dibenzothiophene, 9,9-dimethylfluorenyl, spirofluorenyl, aromatic amino, and carbazole.

5. The biphenyl-naphthalene-substituted aromatic amine compound according to claim 1, characterized in that, Ar is selected from the following groups, either unsubstituted or substituted by Ra: phenyl, biphenyl, terphenyl, naphthyl, phenanthrene, triphenylene, fluorenyl, benzofuranyl, dibenzofuranyl, benzothiophene, dibenzothiophene, 9,9-dimethylfluorenyl, spirofluorenyl, aromatic amino, carbazole.

6. The biphenyl-naphthalene-substituted aromatic amine compound according to claim 1, characterized in that, L is selected from the following groups that are chemically bonded, unsubstituted, or substituted by Ra: phenyl, biphenyl, terphenyl, naphthyl, phenanthrene, triphenylene, fluorenyl, benzofuranyl, dibenzofuranyl, benzothiophene, dibenzothiophene, 9,9-dimethylfluorenyl, spirofluorenyl, aromatic amino, carbazole.

7. The biphenyl-naphthalene-substituted aromatic amine compound according to claim 1, characterized in that, Compounds selected from A1 to A35:

8. A hole transport material, characterized in that, It includes at least one of the biphenyl-naphthalene-substituted aromatic amine compounds according to any one of claims 1 to 7.

9. An organic electroluminescent device, characterized in that, It includes at least one of the hole transport materials of claim 8.

10. A display device, characterized in that, It includes the organic electroluminescent device as described in claim 9.

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