An arylamine-substituted dibenzo five-membered ring compound and its application

Abstract

The present application provides a compound represented by formula (I), which can be used as a light extraction material. The compound provided by the present application has a high steric hindrance skeleton, which can reduce the refractive index of the light extraction material. The organic electroluminescent device provided by the present application includes a first light extraction layer and a second light extraction layer, and there is a synergistic effect between the specific first light extraction layer and the second light extraction layer, which can improve the light extraction efficiency of the light extraction layer. Among them, the first light extraction layer contains the compound of the present application as the light extraction material, and the second light extraction layer can contain a high refractive index material commonly used in the art as the light extraction material, so that the refractive index of the first light extraction layer is lower than that of the second light extraction layer, and the refractive index difference between the two is greater than 0.3, which can effectively promote light extraction, thereby improving the luminous efficiency of the organic electroluminescent device. The display device provided by the present application has excellent display effects.

Description

Technical Field

[0001] The present application relates to the field of organic light-emitting displays, and particularly to a compound, a light extraction material, an organic electroluminescent device, and a display device. Background Art

[0002] Electroluminescence (EL) refers to the phenomenon that a luminescent material emits light under the action of an electric field, being excited by current and voltage. It is a luminescence process that directly converts electrical energy into light energy. Organic electroluminescent displays have a series of advantages such as self-luminescence, low-voltage DC drive, all-solid state, wide viewing angle, light weight, simple composition and process. Compared with liquid crystal displays, organic electroluminescent displays do not require a backlight, have a large viewing angle, low power, a response speed that can reach 1000 times that of liquid crystal displays, and a manufacturing cost lower than that of liquid crystal displays with the same resolution. Therefore, organic electroluminescent devices have very broad application prospects.

[0003] An organic electroluminescent device is a multi-layer organic thin film structure, which includes a light-emitting layer and other functional layers located between a cathode and an anode. After being powered on, the light emitted by the light-emitting layer is transmitted from the side of the transparent electrode, and the light is lost due to waveguide effects such as total internal reflection between the various film layers. The light extraction material forms a light extraction layer on the transparent metal electrode on the upper part of the organic electroluminescent device, thereby adjusting the optical interference distance, suppressing extinction caused by external light reflection and surface plasmon movement, etc., and thus can improve the light extraction efficiency.

[0004] The refractive index is the most important index of the light extraction material. Generally, the higher the refractive index of the light extraction layer, the higher the light extraction efficiency from the electrode to the light extraction layer, and the higher the luminous efficiency of the organic electroluminescent device. At present, one solution is to improve the light extraction efficiency by increasing the refractive index of the single-layer structure light extraction material, but the range of increase in the refractive index of the light extraction material is limited, which restricts the improvement of the luminous efficiency of the organic electroluminescent device. Another solution is to improve the light extraction efficiency by setting a double-layer structure. The light extraction layer includes a high-refractive-index layer and a low-refractive-index layer disposed between the high-refractive-index layer and the cathode. When the refractive indices of the low-refractive-index layer material and the high-refractive-index layer material differ by a certain value, the luminous efficiency can be further improved.

[0005] In the prior art, aromatic compounds are usually used as low-refractive layer materials. However, the refractive index of such compounds is generally high, and the difference with the refractive index of common high-refractive layer materials is small. In the prior art, carbazole derivatives, benzimidazole derivatives, triazole derivatives, diamine aromatic compounds, non-aromatic amine fluorine-containing compounds, aromatic amine fluorine-containing compounds and fluorene-containing compounds are also proposed as low-refractive layer materials. The refractive index of the low-refractive layer materials used in the above-mentioned prior art is high, and the difference with the refractive index of the high-refractive layer materials is small, thus limiting the improvement of the luminous efficiency of the organic electroluminescent device. Summary of the invention

[0006] The purpose of the present application is to provide a compound which, when used as a light extraction material of a low refractive layer, can improve the luminous efficiency of an organic electroluminescent device. The specific technical solution is as follows:

[0007] The first aspect of the present application provides a compound, the structure of which is shown in formula (I):

[0008]

[0009] in,

[0010] X is selected from O, S, NR or CRbRc, Rb, Rc, R are each independently selected from methyl and the following groups represented by N-1 to N-10:

[0011]

[0012] R 1 ~R 4 Each independently selected from hydrogen, fluorine, unsubstituted or Ra-substituted C6-C 15 aryl, unsubstituted or substituted C5~C 20 heteroaryl, unsubstituted or substituted C5~C 10 cycloalkyl, unsubstituted or substituted C1~C 10 alkyl, unsubstituted or substituted by Ra C2~C5 heteroatom-containing cycloalkyl, and R 1 ~R 4 Not at the same time hydrogen;

[0013] The substituents Ra of each group are independently selected from fluorine, trifluoromethyl, cyano, amino, and C1-C4 alkyl;

[0014] The heteroatoms on the heteroaryl group or the heteroatom-containing cycloalkyl group are each independently selected from O, S or N.

[0015] A second aspect of the present application provides a light extraction material comprising at least one of the above compounds.

[0016] The third aspect of the present application provides an organic electroluminescent device, which includes a first light extraction layer and a second light extraction layer. The refractive index of the first light extraction layer is less than that of the second light extraction layer, and the first light extraction layer contains at least one of the above-mentioned light extraction materials.

[0017] The fourth aspect of the present application provides a display device, which includes the above-mentioned organic electroluminescent device.

[0018] Advantages of the present application:

[0019] The compound represented by formula (I) provided by the present application can be used as a light extraction material. The compound provided by the present application includes a dibenzo five-membered ring structure substituted with arylamines having high steric hindrance, which can increase the molar volume of the molecule, reduce the packing density between molecules, and is beneficial to improving the propagation rate of light in the medium, that is, it can reduce the ratio of the propagation rate of light in vacuum and the medium, and thus is beneficial to reducing the refractive index of the light extraction material. The first light extraction layer obtained by using the compound of the present application as the light extraction material has good transparency.

[0020] The organic electroluminescent device provided by the present application includes a first light extraction layer and a second light extraction layer. There is a synergistic effect between the specific first light extraction layer and the second light extraction layer. Specifically, the first light extraction layer is also called the low-refractive-index layer, and the second light extraction layer is also called the high-refractive-index layer. The refractive index of the first light extraction layer is lower than that of the second light extraction layer, which can improve the transmittance of the light extraction layer, reduce its reflection, and thus can improve the light extraction efficiency of the light extraction layer. Among them, the first light extraction layer contains the compound of the present application as the light extraction material, and the second light extraction layer can contain a commonly used high-refractive-index material in the art as the light extraction material, so that the refractive index of the first light extraction layer is lower than that of the second light extraction layer, and the refractive index difference between the light extraction material of the first light extraction layer and the light extraction material of the second light extraction layer is greater than 0.3, which can effectively promote light extraction, thereby improving the luminous efficiency of the organic electroluminescent device. The display device provided by the present application has excellent display effects.

[0021] Of course, it is not necessary for any product or method implementing the present application to achieve all the above-mentioned advantages simultaneously. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the present application or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, other embodiments can also be obtained based on these drawings.

[0023] Figure 1 It is a schematic structural diagram of a typical organic electroluminescent device.

[0024] Figure 2 It is the high performance liquid chromatography (HPLC) spectrum of compound A-35 synthesized in Synthesis Example 6 of the present application. Detailed implementation manners

[0025] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art based on the present application belong to the scope of protection of the present application.

[0026] The first aspect of the present application provides a compound, the structure of which is shown in formula (I):

[0027]

[0028]

[0029] Wherein,

[0030] X is selected from O, S, NR or CRbRc, and Rb, Rc, and R are each independently selected from methyl and the groups shown in N-1 to N-10 below:

[0031]

[0032] R 1 ~R 4 are each independently selected from hydrogen, fluorine, an aryl group of C6-C 15 which is unsubstituted or substituted by Ra, a heteroaryl group of C5-C 20 which is unsubstituted or substituted by Ra, a cycloalkyl group of C5-C 10 which is unsubstituted or substituted by Ra, an alkyl group of C1-C 10 and a heteroatom-containing cycloalkyl group of C2-C5 which is unsubstituted or substituted by Ra, and R 1 ~R 4 are not simultaneously hydrogen;

[0033] The substituents Ra of each group are each independently selected from fluorine, trifluoromethyl, cyano, amino, and an alkyl group of C1-C4;

[0034] The heteroatoms on the heteroaryl group or the heteroatom-containing cycloalkyl group are each independently selected from O, S or N.

[0035] Preferably, Rb, Rc, and R are selected from methyl and the following groups:

[0036]

[0037] Preferably, R 1 ~R 4 are each independently selected from hydrogen, fluorine, trifluoromethyl, methyl, tert-butyl and the groups represented by the following R-1 to R-48:

[0038]

[0039]

[0040] More preferably, R 1 ~R 4 are each independently selected from hydrogen, fluorine, trifluoromethyl, methyl, tert-butyl and the groups represented by the following:

[0041]

[0042] For example, the aforementioned compounds are selected from the compounds represented by the following A-1 to A-43:

[0043]

[0044]

[0045]

[0046] The compound provided in the first aspect of the present application has the structure shown in formula (I). This compound includes a dibenzo five-membered ring structure substituted by an arylamine with high steric hindrance, and at least one phenylene group connected to N is ortho-substituted. The molecular structure of this compound has high steric hindrance and the spatial structure tends to be three-dimensional, which can reduce the packing density between compound molecules and is beneficial to the light propagation rate in the medium, that is, it can reduce the ratio of the light propagation rates in vacuum and in the medium. Therefore, the compound provided in the present application has a lower refractive index when used as a light extraction layer. In addition, the substituents of this compound can also include fluorine-containing substituents. Since the electron polarizability of fluorine atoms is extremely small and the electronegativity is extremely high, the bond energy of the C-F bond is very high, and the volume of the fluorine-containing substituents is relatively large, which can cooperate with the dibenzo five-membered ring structure substituted by an arylamine with high steric hindrance to increase the steric hindrance of the compound and reduce the packing density between compound molecules, which is beneficial to increasing the light propagation speed in the medium, thereby reducing the refractive index of the light extraction material. The first light extraction layer obtained by using the compound of the present application as the light extraction material has good transparency, low dielectric constant and refractive index.

[0047] The second aspect of the present application provides a light extraction material containing at least one of the above compounds. When the compound provided in the present application is used as a light extraction material, it has a lower refractive index.

[0048] In some embodiments of the present application, the refractive index of the light extraction material ≤ 1.59; preferably, the refractive index of the light extraction material for red light ≤ 1.50, for green light ≤ 1.55, and for blue light ≤ 1.59.

[0049] The third aspect of the present application provides an organic electroluminescent device, which includes a first light extraction layer and a second light extraction layer. The refractive index of the first light extraction layer is less than that of the second light extraction layer, and the first light extraction layer contains at least one of the above-mentioned light extraction materials. Among them, the first light extraction layer has good transparency. There is a synergistic effect between the first light extraction layer and the second light extraction layer in the organic electroluminescent device provided by the present application, which can improve the light extraction efficiency of the light extraction layer. Among them, the first light extraction layer contains the compound of the present application as the light extraction material, and the second light extraction layer may contain a commonly used high refractive index material in the art as the light extraction material, so that the refractive index of the first light extraction layer is lower than that of the second light extraction layer, which is beneficial to promoting light extraction and improving the luminous efficiency of the organic electroluminescent device. The inventors found that when the difference in refractive index between the light extraction material of the first light extraction layer and the light extraction material of the second light extraction layer is more than 0.3, it can further effectively promote light extraction, thereby further improving the luminous efficiency of the organic electroluminescent device.

[0050] In the present application, there is no particular limitation on the type and structure of the organic electroluminescent device, and it can be various types and structures of organic electroluminescent devices well-known in the art, as long as at least one of the light extraction materials provided by the present application can be used.

[0051] The organic electroluminescent device of the present application can be a top-emitting structure light-emitting device, and examples include an anode, a hole injection layer, a hole transport layer, a light-emitting layer, an electron transport layer, an electron injection layer, a transparent or semi-transparent cathode, a first light extraction layer, and a second light extraction layer sequentially disposed on a substrate.

[0052] The organic electroluminescent device of the present application can also be a bottom-emitting structure light-emitting device, and examples include a second light extraction layer, a first light extraction layer, 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 cathode sequentially disposed on a substrate.

[0053] The organic electroluminescent device of the present application can also be a double-sided emitting structure light-emitting device, and examples include a second light extraction layer, a first light extraction layer, 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, a transparent or semi-transparent cathode, a first light extraction layer, and a second light extraction layer sequentially disposed on a substrate.

[0054] In addition, an electron blocking layer may be provided between the hole transport layer and the light-emitting layer, and a hole blocking layer may be provided between the light-emitting layer and the electron transport layer. However, the structure of the organic electroluminescent device of the present application is not limited to the above specific structure, and if necessary, the above layers may be omitted or added. The present application does not particularly limit the thickness of the above layers, as long as the object of the present application can be achieved. For example, the organic electroluminescent device may sequentially include an anode (100 nm to 150 nm) made of a metal oxide or a metal, a hole injection layer (5 nm to 20 nm), a hole transport layer (80 nm to 140 nm), an electron blocking layer (5 nm to 15 nm), a light-emitting layer (20 nm to 45 nm), a hole blocking layer (5 nm to 15 nm), an electron transport layer (30 nm to 40 nm), an electron injection layer (0.3 nm to 1 nm), a cathode (10 nm to 16 nm), a first light extraction layer (5 nm to 50 nm), and a second light extraction layer (50 nm to 90 nm) on a substrate.

[0055] The present application does not particularly limit the material of the substrate, and conventional substrates used in organic electroluminescent devices in the prior art may be used, such as glass, polymer materials, glass and polymer materials with thin film transistor (TFT) components, and the like.

[0056] Figure 1 FIG. shows a schematic diagram of a typical organic electroluminescent device 100, in which, from bottom to top, a substrate 10, an anode electrode 11, a hole injection layer 12, a hole transport layer 13, an electron blocking layer 14, a light-emitting layer 15, a hole blocking layer 16, an electron transport layer 17, an electron injection layer 18, a cathode electrode 19, and a light extraction layer 21 are sequentially provided, and the light extraction layer 21 includes a first light extraction layer 211 and a second light extraction layer 212.

[0057] It can be understood that Figure 1 only schematically shows the structure of a typical organic electroluminescent device, and the present application is not limited to this structure. The light extraction material of the present application can be used in any type of organic electroluminescent device.

[0058] In the organic electroluminescent device of the present application, except that the light extraction layer contains the light extraction material provided by the present application, various materials used for the layers in the prior art can be used for the other layers.

[0059] For convenience, the organic electroluminescent device of the present application will be described below with reference to Figure 1 However, this does not mean any limitation to the protection scope of the present application. It can be understood that all organic electroluminescent devices that can use the light extraction material of the present application are within the protection scope of the present application.

[0060] In this application, the material of the substrate 10 is not particularly limited, and conventional substrates used in organic electroluminescent devices in the prior art can be used. For example, glass, polymer materials, glass and polymer materials with thin film transistor (TFT) components, etc.

[0061] In this application, the material of the anode electrode 11 is not particularly limited and can be selected from anode electrodes known in the prior art. For example, metals, alloys or conductive compounds with a high work function (≥4 eV), specifically, transparent conductive materials such as indium tin oxide (ITO), indium zinc oxide (IZO), tin dioxide (SnO2), zinc oxide (ZnO), low-temperature polycrystalline silicon (LTPS), etc. can be selected. Metal materials such as silver and its alloys, aluminum and its alloys can also be selected. Organic conductive materials such as poly(3,4-ethylenedioxythiophene) (PEDOT) can also be selected. Amorphous materials that can form a transparent conductive film, such as In2O3-ZnO (IDIXO), can also be selected. Or the anode electrode is a multilayer structure formed of the above materials. The number of layers of the multilayer structure in this application is not particularly limited and can be selected according to actual needs as long as the purpose of this application can be satisfied. For example, 1 layer, 2 layers, 3 layers or more layers. In this application, the thickness of the anode electrode varies according to the material used, as long as it is within the above range of this application and can achieve the purpose of this application.

[0062] In this application, the material of the hole injection layer 12 is not particularly limited, and hole injection layer materials known in the art can be used. For example, a hole transport material (HTM) can be selected as the hole injection material.

[0063] In this application, the hole injection layer 12 may also include a p-type dopant. The type of the p-type dopant is not particularly limited, and various p-type dopants known in the art can be used. For example, the following p-type dopants can be used:

[0064]

[0065] In this application, the dosage of the p-type dopant is not particularly limited and can be the dosage known to those skilled in the art.

[0066] In this application, the material of the hole transport layer 13 is not particularly limited and can be made of hole transport materials (HTM) known in the art. The number of layers of the hole transport layer 13 is not particularly limited and can be adjusted according to actual needs as long as the purpose of this application can be satisfied. For example, 1 layer, 2 layers, 3 layers, 4 layers or more layers.

[0067] For example, the materials for the hole injection layer and the materials for the hole transport layer can each independently be selected from, but not limited to, at least one of the following compounds HT-1 to HT-32:

[0068]

[0069]

[0070] Optionally, the organic electroluminescent device may include an electron blocking layer 14. In the present application, the material of the electron blocking layer 14 is not particularly limited, and the electron blocking layer materials known in the art can be used. For example, it can be selected from, but not limited to, the following EB-1 to EB-5 compounds:

[0071]

[0072] In the present application, the material of the light-emitting layer 15 includes a light-emitting layer host material and a light-emitting layer guest material. Among them, the amounts of the light-emitting layer host material and the light-emitting layer guest material are not particularly limited and can be the amounts well-known to those skilled in the art.

[0073] In the present application, the light-emitting layer host material is not particularly limited, and at least one of the red light-emitting layer host materials known in the art can be used. For example, it can be selected from, but not limited to, at least one of the following RH-1 to RH-14 compounds:

[0074]

[0075] At least one of the green light-emitting layer host materials known in the art can also be used as the light-emitting layer host material. For example, it can be selected from, but not limited to, at least one of the following GPH-1 to GPH-81 compounds:

[0076]

[0077]

[0078]

[0079] At least one of the blue light-emitting layer host materials known in the art can also be used as the light-emitting layer host material. For example, it can be selected from, but not limited to, at least one of the following BH-1 to BH-10 compounds:

[0080]

[0081] The light-emitting layer guest material can be a red light-emitting layer guest material. For example, it can be selected from, but not limited to, at least one of the following RPD-1 to RPD-28 compounds:

[0082]

[0083] The light-emitting layer guest material can be a green light-emitting layer guest material. For example, it can be selected from, but not limited to, at least one of the following GD01 to GD04 compounds:

[0084]

[0085] The host material of the light-emitting layer can be a host material for a blue light-emitting layer. For example, it can be selected from but not limited to at least one of the following compounds BD-1 to BD-10:

[0086]

[0087] Optionally, the organic electroluminescent device may include a hole blocking layer 16. In the present application, the material of the hole blocking layer 16 is not particularly limited, and hole blocking layer materials known in the art can be used. For example, the known hole blocking layer materials can be selected from but not limited to at least one of the following compounds ET-1 to ET-63:

[0088]

[0089]

[0090]

[0091]

[0092] In the present application, the material of the electron transport layer 17 is not particularly limited, and electron transport materials known in the art can be used. For example, the known electron transport materials can be selected from but not limited to at least one of the above compounds ET-1 to ET-61.

[0093] In the present application, the electron transport layer 17 may further include an n-type dopant. The type of the n-type dopant is not particularly limited, and various n-type dopants known in the art can be adopted. For example, the following n-type dopants can be adopted:

[0094]

[0095] In the present application, the amount of the n-type dopant is not particularly limited and can be the amount known to those skilled in the art.

[0096] In the present application, the material of the electron injection layer 18 is not particularly limited, and electron injection materials known in the art can be used. For example, it can include but not limited to at least one of materials such as lithium 8-hydroxyquinoline (LiQ), LiF, NaCl, CsF, Li2O, Cs2CO3, BaO, Yb, Na, Li, Ca, etc.

[0097] In the present application, the material of the cathode electrode 19 is not particularly limited and can be selected from but not limited to metal, oxides such as magnesium-silver mixture, magnesium-aluminum mixture, LiF / aluminum, ITO, aluminum, etc.

[0098] In the present application, the light extraction layer 21 includes a first light extraction layer 211 and a second light extraction layer 212. The first light extraction layer 211 contains at least one of the light extraction materials of the present application, and the refractive index of the first light extraction layer is lower than that of the second light extraction layer, thereby facilitating light extraction. In order to improve the light extraction efficiency, the light extraction layer 21 of the present application is disposed on the transparent electrode on the light emitting side, and the first light extraction layer is disposed between the transparent electrode and the second light extraction layer.

[0099] In the present application, the second light extraction layer 212 may contain a high refractive index material known in the art as the light extraction material, and the refractive index of the selected high refractive index material needs to differ from the refractive index of the light extraction material of the present application by more than 0.3. For example, the known high refractive index materials may be selected from, but not limited to, at least one of the following compounds C-1 to C-63:

[0100]

[0101]

[0102]

[0103] The present application has no particular limitation on the preparation method of the organic electroluminescent device, and any method known in the art can be adopted. For example, it may include, but not limited to, the following steps:

[0104] (1) Clean the anode electrode 11 on the substrate 10 of the top-emitting organic electroluminescent device, and in a cleaning machine, respectively pass through steps such as chemical cleaning, water washing, brushing, high-pressure water washing, air knife, etc., and then perform heat treatment; wherein, the chemical solution used in the chemical cleaning can be a chemical solution known in the art, and the present application does not limit this; the conditions of steps such as water washing, brushing, high-pressure water washing, air knife, etc. can also be conditions known in the art, and the present application does not limit this;

[0105] (2) Vacuum deposit a hole injection layer 12 on the anode electrode 11, and the hole injection layer 12 contains a hole injection material and a p-type dopant;

[0106] (3) Vacuum deposit a hole transporting material as a hole transport layer 13 on the hole injection layer 12;

[0107] (4) Vacuum deposit an electron blocking material as an electron blocking layer 14 on the hole injection layer 13;

[0108] (5) Vacuum deposit a light emitting layer 15 on the electron blocking layer 14, and the light emitting layer 15 contains a host material and a guest material;

[0109] (6) Deposit a hole blocking material as a hole blocking layer 16 on the light emitting layer 15;

[0110] (7) A hole blocking layer 16 is vacuum-evaporated with an electron transport material as an electron transport layer 17, and the electron transport layer 17 contains an electron transport material and an n-type dopant;

[0111] (8) An electron injection material is vacuum-evaporated on the electron transport layer 17 as an electron injection layer 18;

[0112] (9) A cathode material is vacuum-evaporated on the electron injection layer 18 as a cathode electrode 19;

[0113] (10) A material of a first light extraction layer 211 is evaporated on the cathode electrode 19 as the first light extraction layer 211;

[0114] (11) A material of a second light extraction layer 212 is evaporated on the first light extraction layer 211 as the second light extraction layer 212.

[0115] The fourth aspect of the present application provides a display device, which includes the above-mentioned organic electroluminescent device. Therefore, the display device provided by the present application has good display performance. The display device may include, but is not limited to, a display, a television, a tablet computer, a mobile communication terminal, etc.

[0116] Testing methods and equipment:

[0117] Testing of compound purity:

[0118] The high-performance liquid chromatography (HPLC) purity and HPLC chromatogram of the compound are determined using an LC-20AXR high-performance liquid chromatograph, and the wavelength of detector A is 254 nm.

[0119] Testing of refractive index:

[0120] The size of the glass substrate is 200 mm × 200 mm, the thickness of the material thin film is 80 nm. Using a Version-1.0.1.4 spectroscopic ellipsometer of Radiation technology company, and adopting the EMA (Effective Medium Approximation) method, the refractive index (n) of the compounds in each example and comparative example at different wavelengths is determined. Among them, the material thin film is formed by evaporating the compounds of each example or comparative example on the glass substrate, the evaporation rate is 0.1 nm / s, and the evaporation film thickness is 80 nm.

[0121] Performance detection of organic electroluminescent devices:

[0122] A brightness-current density-voltage (BJV) test system is used to test the current efficiency and CIE color coordinates of the organic electroluminescent device.

[0123] For blue light devices, the luminous efficiency is examined using the blue light index (BI). When the emission colors are the same or similar (i.e., the CIE coordinates are the same or similar), the larger the BI value, the better the luminous performance of the blue light device. For green organic electroluminescent devices (green devices) and red organic electroluminescent devices (red devices), the luminous efficiency is mainly evaluated using the current efficiency. When the emission colors are the same or similar (i.e., the CIE coordinates are the same or similar), the larger the current efficiency, the better the luminous performance of the green and red devices.

[0124] There is no particular limitation on the synthesis method of the compounds of the present application, 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 application.

[0125] Synthesis Example

[0126] The raw materials used in the synthesis examples of the present application are all chemical raw materials well-known to those skilled in the chemical industry. The raw material information is as follows:

[0127] F-0: Chinese name, 2-aminophenylboronic acid; CAS NO. 5570-18-3.

[0128] F-1: Chinese name, bromopentafluorobenzene; CAS NO. 344-04-7.

[0129] F-2: Chinese name, 2-bromophenylboronic acid; CAS NO. 244205-40-1.

[0130] F-3: Chinese name, 2-chlorophenylboronic acid; CAS NO. 3900-89-8.

[0131] F-4: Chinese name, 1-chlorodibenzofuran; CAS NO. 84761-86-4.

[0132] F-5: Chinese name, 3,5-bis(trifluoromethyl)bromobenzene; CAS NO. 328-70-1.

[0133] F-6: Chinese name, 4-chlorophenylboronic acid; CAS NO. 1679-18-1.

[0134] F-7: Chinese name, 4-tert-butylbromobenzene; CAS NO. 3972-65-4.

[0135] F-8: Chinese name, 4-aminophenylboronic acid; CAS NO. 89415-43-0.

[0136] F-9: Chinese name, 1-chlorodibenzothiophene; CAS NO. 109014-36-0.

[0137] F-10: Chinese name, 4-chlorocarbazole; CAS NO. 3652-88-8.

[0138] F-11: Chinese name, bromocyclohexane; CAS NO. 108-85-0.

[0139] F-12: Chinese name, 4-amino-9,9-dimethylfluorene; CAS NO. 2249831-75-0.

[0140] F-13: Chinese name, 2-chloroadamantane; CAS NO. 7346-41-0.

[0141] F-14: Chinese name, 2-chlorophenylboronic acid; CAS NO. 3900-89-8.

[0142] F-15: Chinese name, benzophenone; CAS NO. 119-61-9.

[0143] F-16: Chinese name, 3,3’,5,5’-tetrakis(trifluoromethyl)benzophenone; CAS NO. 175136-66-0.

[0144] F-17: Chinese name, 2-bromo-2’-chloro-1,1’-biphenyl; CAS NO. 107208-70-8.

[0145] Synthesis Example 1: Synthesis of Compound A-3

[0146]

[0147] <Preparation of Intermediate M0>

[0148] Add 100 mmol of F-1, 100 mmol of F-0, 41.4 g (300 mmol) of potassium carbonate, 800 ml of tetrahydrofuran (THF), 200 ml of water into the reaction flask, and add 1 mol% of tetrakis(triphenylphosphine)palladium (Pd(PPh3)4). React at 120 °C for 12 h. After the reaction is completed, stop the reaction, cool the reactant to room temperature, add water, concentrate the organic phase to obtain a white solid, filter, wash with water, and recrystallize and purify the obtained solid with toluene to obtain white powder M0. Among them, the addition amount of Pd(PPh3)4 is 1 mol% of F-1.

[0149] <Preparation of Intermediate M1>

[0150] Add 100 mmol of F-1, 100 mmol of F-2, 41.4 g (300 mmol) of potassium carbonate, 800 ml of THF, 200 ml of water into a reaction flask, and add 1 mol% of Pd(PPh3)4. React at 120 °C for 12 h. After the reaction is completed, stop the reaction, cool the reactants to room temperature, add water, concentrate the organic phase to obtain a white solid, filter, wash with water, and recrystallize and purify the obtained solid with toluene to obtain white powder M1. Among them, the addition amount of Pd(PPh3)4 is 1 mol% of F-1.

[0151] <Preparation of Intermediate M2>

[0152] Add 100 mmol of M1, 100 mmol of F-3, 41.4 g (300 mmol) of potassium carbonate, 800 ml of THF, 200 ml of water into a reaction flask, and add 1 mol% of Pd(PPh3)4. React at 120 °C for 12 h. After the reaction is completed, stop the reaction, cool the reactants to room temperature, add water, concentrate the organic phase to obtain a white solid, filter, wash with water, and recrystallize and purify the obtained solid with toluene to obtain white powder M2. Among them, the addition amount of Pd(PPh3)4 is 1 mol% of M1.

[0153] <Preparation of Intermediate M3>

[0154] Add 100 mmol of M2, 100 mmol of M0, 28.83 g (300 mmol) of sodium tert-butoxide, 800 ml of xylene into a reaction flask, and add 1 mol% of bis(benzylideneacetone)palladium (Pd(dba)2). React at 120 °C for 12 h. After the reaction is completed, stop the reaction, cool the reactants to room temperature, add water, filter, wash with water, and recrystallize and purify the obtained solid with toluene to obtain white powder M3. Among them, the addition amount of Pd(dba)2 is 1 mol% of M2.

[0155] <Preparation of Compound A-3>

[0156] Add 100 mmol of F-4, 100 mmol of M3, 28.83 g (300 mmol) of sodium tert-butoxide, 800 ml of xylene into a reaction flask, and add 1 mol% of Pd(dba)2. React at 120 °C for 12 h. After the reaction is completed, stop the reaction, cool the reactants to room temperature, add water, filter, wash with water, and recrystallize and purify the obtained solid with toluene to obtain white powder of Compound A-3. Among them, the addition amount of Pd(dba)2 is 1 mol% of F-4.

[0157] The HPLC purity of the prepared Compound A-3 is 99.9%.

[0158] 1H NMR (300 MHz, Chloroform-d) δ 8.10 - 7.96 (m, 5H), 7.60 - 7.54 (m, 3H), 7.39 - 7.25 (m, 8H), 7.14 (m, 2H), 6.91 (s, 1H).

[0159] Synthesis Example 2: Synthesis of Compound A-4

[0160]

[0161] <Preparation of Intermediate M0> The same as in Synthesis Example 1.

[0162] <Preparation of Intermediate M1>

[0163] Add 100 mmol of F-2, 100 mmol of F-5, 41.4 g (300 mmol) of potassium carbonate, 800 ml of THF, 200 ml of water to a reaction flask, and add 1 mol% of Pd(PPh3)4. React at 120 °C for 12 h. After the reaction is completed, stop the reaction, cool the reactant to room temperature, add water, concentrate the organic phase to obtain a white solid, filter, wash with water, and recrystallize and purify the obtained solid with toluene to obtain white powder M1. Among them, the addition amount of Pd(PPh3)4 is 1 mol% of F-2.

[0164] <Preparation of Intermediate M2>

[0165] Add 100 mmol of M1, 100 mmol of F-3, 41.4 g (300 mmol) of potassium carbonate, 800 ml of THF, 200 ml of water to a reaction flask, and add 1 mol% of Pd(PPh3)4. React at 120 °C for 12 h. After the reaction is completed, stop the reaction, cool the reactant to room temperature, add water, concentrate the organic phase to obtain a white solid, filter, wash with water, and recrystallize and purify the obtained solid with toluene to obtain white powder M2. Among them, the addition amount of Pd(PPh3)4 is 1 mol% of M1.

[0166] <Preparation of Intermediate M3>

[0167] Add 100 mmol of M2, 100 mmol of M0, 28.83 g (300 mmol) of sodium tert-butoxide, 800 ml of xylene to a reaction flask, and add 1 mol% of Pd(dba)2. React at 120 °C for 12 h. After the reaction is completed, stop the reaction, cool the reactant to room temperature, add water, filter, wash with water, and recrystallize and purify the obtained solid with toluene to obtain white powder M3. Among them, the addition amount of Pd(dba)2 is 1 mol% of M2.

[0168] <Preparation of Compound A-4>

[0169] Add 100 mmol of F-4, 100 mmol of M3, 28.83 g (300 mmol) of sodium tert-butoxide, 800 ml of xylene into a reaction flask, and add 1 mol% of Pd(dba)2. React at 120 °C for 12 h. After the reaction is completed, stop the reaction, cool the reactant to room temperature, add water, filter, wash with water, and recrystallize and purify the obtained solid with toluene to obtain white powder of Compound A-4. Among them, the addition amount of Pd(dba)2 is 1 mol% of F-4.

[0170] The HPLC purity of the prepared Compound A-4 is 99.9%.

[0171] 1H NMR (300 MHz, Chloroform-d) δ 8.33 (s, 1H), 8.10 - 7.96 (m, 7H), 7.60 - 7.54 (m, 3H), 7.39 - 7.25 (m, 8H), 7.14 (m, 2H), 6.91 (s, 1H).

[0172] Synthesis Example 3: Synthesis of Compound A-6

[0173]

[0174] <Preparation of Intermediate M0>

[0175] Add 100 mmol of F-7, 100 mmol of F-0, 41.4 g (300 mmol) of potassium carbonate, 800 ml of THF, 200 ml of water into a reaction flask, and add 1 mol% of (Pd(PPh3)4). React at 120 °C for 12 h. After the reaction is completed, stop the reaction, cool the reactant to room temperature, add water, concentrate the organic phase to obtain a white solid, filter, wash with water, and recrystallize and purify the obtained solid with toluene to obtain white powder M0. Among them, the addition amount of Pd(PPh3)4 is 1 mol% of F-7.

[0176] <Preparation of Intermediate M1>

[0177] Add 100 mmol of F-5, 100 mmol of F-3, 41.4 g (300 mmol) of potassium carbonate, 800 ml of THF, 200 ml of water into a reaction flask, and add 1 mol% of Pd(PPh3)4. React at 120 °C for 12 h. After the reaction is completed, stop the reaction, cool the reactants to room temperature, add water, concentrate the organic phase to obtain a white solid, filter, wash with water, and recrystallize and purify the obtained solid with toluene to obtain white powder M1. Among them, the addition amount of Pd(PPh3)4 is 1 mol% of F-5.

[0178] <Preparation of Intermediate M2>

[0179] Add 100 mmol of M1, 100 mmol of M0, 28.83 g (300 mmol) of sodium tert-butoxide, 800 ml of xylene into a reaction flask, and add 1 mol% of Pd(dba)2. React at 120 °C for 12 h. After the reaction is completed, stop the reaction, cool the reactants to room temperature, add water, filter, wash with water, and recrystallize and purify the obtained solid with toluene to obtain white powder M2. Among them, the addition amount of Pd(dba)2 is 1 mol% of M1.

[0180] <Preparation of Compound A-6>

[0181] Add 100 mmol of F-4, 100 mmol of M2, 28.83 g (300 mmol) of sodium tert-butoxide, 800 ml of xylene into a reaction flask, and add 1 mol% of Pd(dba)2. React at 120 °C for 12 h. After the reaction is completed, stop the reaction, cool the reactants to room temperature, add water, filter, wash with water, and recrystallize and purify the obtained solid with toluene to obtain white powder of Compound A-6. Among them, the addition amount of Pd(dba)2 is 1 mol% of F-4.

[0182] The HPLC purity of the prepared Compound A-6 is 99.9%.

[0183] 1H NMR (300 MHz, Chloroform-d) δ 8.33 (s, 1H), 8.10 - 7.98 (m, 5H), 7.54 (s, 1H), 7.39 - 7.30 (m, 11H), 7.25 (s, 1H), 7.14 (m, 2H), 6.91 (s, 1H), 1.33 (m, 9H).

[0184] Synthesis Example 4: Synthesis of Compound A-14

[0185]

[0186] <Preparation of Intermediate M0>

[0187] Add 100 mmol of F-1, 100 mmol of F-8, 41.4 g (300 mmol) of potassium carbonate, 800 ml of THF, 200 ml of water into a reaction flask, and add 1 mol% of Pd(PPh3)4. React at 120 °C for 12 h. After the reaction is completed, stop the reaction, cool the reactants to room temperature, add water, concentrate the organic phase to obtain a white solid, filter, wash with water, and recrystallize and purify the obtained solid with toluene to obtain white powder M0. Among them, the addition amount of Pd(PPh3)4 is 1 mol% of F-1.

[0188] The preparation of <Intermediate M1> and <Intermediate M2> is the same as that in Synthesis Example 2.

[0189] <The preparation of Intermediate M3>

[0190] Add 100 mmol of M2, 100 mmol of M0, 28.83 g (300 mmol) of sodium tert-butoxide, 800 ml of xylene into a reaction flask, and add 1 mol% of Pd(dba)2. React at 120 °C for 12 h. After the reaction is completed, stop the reaction, cool the reactants to room temperature, add water, filter, wash with water, and recrystallize and purify the obtained solid with toluene to obtain white powder M3. Among them, the addition amount of Pd(dba)2 is 1 mol% of M2.

[0191] <The preparation of Compound A-14>

[0192] Add 100 mmol of F-9, 100 mmol of M3, 28.83 g (300 mmol) of sodium tert-butoxide, 800 ml of xylene into a reaction flask, and add 1 mol% of Pd(dba)2. React at 120 °C for 12 h. After the reaction is completed, stop the reaction, cool the reactants to room temperature, add water, filter, wash with water, and recrystallize and purify the obtained solid with toluene to obtain white powder Compound A-14. Among them, the addition amount of Pd(dba)2 is 1 mol% of F-9.

[0193] The HPLC purity of the prepared Compound A-14 is 99.9%.

[0194] 1H NMR (300 MHz, Chloroform-d) δ 8.45 - 8.33 (m, 2H), 8.10 - 7.93 (m, 6H), 7.60 - 7.55 (m, 6H), 7.49 - 7.37 (m, 7H), 7.14 (s, 1H).

[0195] Synthesis Example 5: Synthesis of Compound A-16

[0196]

[0197] The preparation of intermediate M0, the preparation of intermediate M1, and the preparation of intermediate M2 are the same as those in Synthesis Example 3.

[0198] The preparation of intermediate M3

[0199] 100 mmol of F-5, 120 mmol of F-10, 1.9 g (10 mmol) of cuprous iodide, 27.2 g (200 mmol) of anhydrous potassium carbonate, 2.0 g (10 mmol) of 1,10-phenanthroline monohydrate, and 730 g (10 mol) of N,N-dimethylformamide were added to a reaction flask, and the reaction was carried out at 120 °C for 20 h under nitrogen protection. 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 the obtained solid was eluted and purified with petroleum ether to obtain white powder M3.

[0200] The preparation of compound A-16

[0201] 100 mmol of M3, 100 mmol of M2, 28.83 g (300 mmol) of sodium tert-butoxide, 800 ml of xylene were added to a reaction flask, and 1 mol% of Pd(dba)2 was added. 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, and the mixture was filtered and washed with water. The obtained solid was recrystallized and purified with toluene to obtain white powder compound A-16. Among them, the addition amount of Pd(dba)2 was 1 mol% of M3.

[0202] The HPLC purity of the prepared compound A-16 was 99.9%.

[0203] 1H NMR (300 MHz, Chloroform-d) δ 8.33 - 8.19 (m, 2H), 8.10 - 8.07 (m, 6H), 7.87 (s, 1H), 7.60 - 7.50 (m, 3H), 7.39 - 7.20 (m, 10H), 7.14 (m, 2H), 6.40 (s, 1H), 1.33 (m, 9H).

[0204] Synthesis Example 6: Synthesis of compound A-33

[0205]

[0206] The preparation of intermediate M1

[0207] Add 100 mmol of F-1, 100 mmol of F-2, 41.4 g (300 mmol) of potassium carbonate, 800 ml of THF, 200 ml of water to a reaction flask, and add 1 mol% of Pd(PPh3)4. React at 120 °C for 12 h. After the reaction is completed, stop the reaction, cool the reactant to room temperature, add water, concentrate the organic phase to obtain a white solid, filter, wash with water, and recrystallize and purify the obtained solid with toluene to obtain white powder M1. Among them, the addition amount of Pd(PPh3)4 is 1 mol% of F-1.

[0208] <Preparation of Intermediate M2>

[0209] Add 100 mmol of F-2, 100 mmol of M1, 41.4 g (300 mmol) of potassium carbonate, 800 ml of THF, 200 ml of water to a reaction flask, and add 1 mol% of Pd(PPh3)4. React at 120 °C for 12 h. After the reaction is completed, stop the reaction, cool the reactant to room temperature, add water, concentrate the organic phase to obtain a white solid, filter, wash with water, and recrystallize and purify the obtained solid with toluene to obtain white powder M2. Among them, the addition amount of Pd(PPh3)4 is 1 mol% of F-2.

[0210] <Preparation of Compound A-33>

[0211] Add 100 mmol of F-12, 200 mmol of M2, 19.22 g (200 mmol) of sodium tert-butoxide to a reaction flask, and add 1 mol% of tris(dibenzylideneacetone) dipalladium (Pd2(dba)3), 4 mol% of 2-cyclohexylphosphine-2,4,6-triisopropylbiphenyl (X-PHOS). React at 110 °C for 12 h. After the reaction is completed, stop the reaction, cool the reactant to room temperature, add water, concentrate the organic phase to obtain a white solid, filter, wash with water, and recrystallize and purify the obtained solid with toluene to obtain white powder A-33. Among them, the addition amount of Pd2(dba)3 is 1 mol% of F-12, and the addition amount of X-PHOS is 4 mol% of F-12.

[0212] The HPLC purity of the prepared compound A-33 is 99.9%.

[0213] 1H NMR (300 MHz, Chloroform-d) δ 8.10 - 7.90 (m, 7H), 7.60 - 7.55 (m, 5H), 7.39 - 7.37 (m, 5H), 7.28 - 7.21 (m, 3H), 7.16 - 7.14 (m, 3H), 1.69 (m, 6H).

[0214] Synthesis Example 7: Synthesis of Compound A-35

[0215]

[0216] <Preparation of Intermediate M1>

[0217] Add 100 mmol of F-11, 100 mmol of F-2, 41.4 g (300 mmol) of potassium carbonate, 800 ml of THF, 200 ml of water to a reaction flask, and add 1 mol% of Pd(PPh3)4. React at 120 °C for 12 h. After the reaction is completed, stop the reaction, cool the reactant to room temperature, add water, concentrate the organic phase to obtain a white solid, filter, wash with water, and recrystallize and purify the obtained solid with toluene to obtain white powder M1. Among them, the addition amount of Pd(PPh3)4 is 1 mol% of F-11.

[0218] <Preparation of Intermediate M2>

[0219] Add 100 mmol of F-2, 100 mmol of M1, 41.4 g (300 mmol) of potassium carbonate, 800 ml of THF, 200 ml of water to a reaction flask, and add 1 mol% of Pd(PPh3)4. React at 120 °C for 12 h. After the reaction is completed, stop the reaction, cool the reactant to room temperature, add water, concentrate the organic phase to obtain a white solid, filter, wash with water, and recrystallize and purify the obtained solid with toluene to obtain white powder M2. Among them, the addition amount of Pd(PPh3)4 is 1 mol% of F-2.

[0220] <Preparation of Compound A-35>

[0221] Add 100 mmol of F-12, 200 mmol of M2, 19.22 g (200 mmol) of sodium tert-butoxide to a reaction flask, and add 1 mol% of tris(dibenzylideneacetone)dipalladium (Pd2(dba)3), 4 mol% of 2-dicyclohexylphosphino-2,4,6-triisopropylbiphenyl (X-PHOS). React under reflux at 120 °C for 12 h. After the reaction is completed, stop the reaction, cool the reactant to room temperature, add water, concentrate the organic phase to obtain a white solid, filter, wash with water, and recrystallize and purify the obtained solid with toluene to obtain white powder of Compound A-35. Among them, the addition amount of Pd2(dba)3 is 1 mol% of F-12, and the addition amount of X-PHOS is 4 mol% of F-12.

[0222] The HPLC purity of the prepared Compound A-35 is 99.9%, and its HPLC chromatogram is as Figure 2 shown.

[0223] 1H NMR (300 MHz, Chloroform-d) δ 8.10 - 7.90 (m, 3H), 7.77 - 7.51 (m, 5H), 7.40 - 7.21 (m, 12H), 7.16 - 7.14 (m, 3H), 2.72 (m, 2H), 1.86 - 1.43 (m, 26H).

[0224] Synthesis Example 8: Synthesis of Compound A-40

[0225]

[0226] <Preparation of Intermediate M3> The same as Synthesis Example A-16

[0227] <Preparation of Intermediate M1>

[0228] Add 100 mmol of F-6, 100 mmol of M3, 41.4 g (300 mmol) of potassium carbonate, 800 ml of THF, 200 ml of water to a reaction flask, and add 1 mol% of Pd(PPh3)4. React at 120 °C for 12 h. After the reaction is completed, stop the reaction, cool the reactant to room temperature, add water, concentrate the organic phase to obtain a white solid, filter, wash with water, and recrystallize and purify the obtained solid with toluene to obtain white powder M1. Among them, the addition amount of Pd(PPh3)4 is 1 mol% of F-6.

[0229] <Preparation of Intermediate M2>

[0230] Add 100 mmol of F-14, 100 mmol of M1, 41.4 g (300 mmol) of potassium carbonate, 800 ml of THF, 200 ml of water to a reaction flask, and add 1 mol% of Pd(PPh3)4. React at 120 °C for 12 h. After the reaction is completed, stop the reaction, cool the reactant to room temperature, add water, concentrate the organic phase to obtain a white solid, filter, wash with water, and recrystallize and purify the obtained solid with toluene to obtain white powder M2. Among them, the addition amount of Pd(PPh3)4 is 1 mol% of F-14.

[0231] <Preparation of Intermediate M4>

[0232] Add 100 mmol of F-12, 100 mmol of M2, 28.83 g (300 mmol) of sodium tert-butoxide, 800 ml of xylene to a reaction flask, and add 1 mol% of Pd(dba)2. React at 120 °C for 12 h. After the reaction is completed, stop the reaction, cool the reactant to room temperature, add water, filter, wash with water, and recrystallize and purify the obtained solid with toluene to obtain white powder M4. Among them, the addition amount of Pd(dba)2 is 1 mol% of F-12.

[0233] <Preparation of Intermediate M5>

[0234] Add 100 mmol of F-3, 100 mmol of F-13, 41.4 g (300 mmol) of potassium carbonate, 800 ml of THF, 200 ml of water into a reaction flask, and add 1 mol% of Pd(PPh3)4. React at 120 °C for 12 h. After the reaction is completed, stop the reaction, cool the reactant to room temperature, add water, concentrate the organic phase to obtain a white solid, filter, wash with water, and recrystallize and purify the obtained solid with toluene to obtain white powder M5. Among them, the addition amount of Pd(PPh3)4 is 1 mol% of F-3.

[0235] <Preparation of Compound A-40>

[0236] Add 100 mmol of M5, 100 mmol of M4, 28.83 g (300 mmol) of sodium tert-butoxide, 800 ml of xylene into a reaction flask, and add 1 mol% of Pd(dba)2. React at 120 °C for 12 h. After the reaction is completed, stop the reaction, cool the reactant to room temperature, add water, filter, wash with water, and recrystallize and purify the obtained solid with toluene to obtain white powder of compound A-40. Among them, the addition amount of Pd(dba)2 is 1 mol% of M4.

[0237] The HPLC purity of the prepared compound A-40 is 99.9%.

[0238] 1H NMR (300 MHz, Chloroform-d) 8.22 - 8.04 (m, 6H), 7.90 - 7.87 (m, 2H), 7.58 - 7.37 (m, 7H), 7.28 - 6.96 (m, 14H), 3.04 (s, 1H), 2.25 (m, 2H), 1.87 - 1.69 (m, 18H).

[0239] Synthesis Example 9: Synthesis of Compound A-42

[0240]

[0241] <Preparation of Intermediate M3> is the same as that in Synthesis Example 1.

[0242] <Preparation of Intermediate M1>

[0243] Under nitrogen protection, 100 mmol of F-17, 250 ml of THF were added to a reaction flask, and 115 ml of sec-butyllithium was added. The mixture was kept at -70 °C for 1 h, then 100 mmol of F-15 was added, and the reaction was carried out at -70 °C for 1 h. After the reaction was completed, the reaction was stopped, and the reactants were heated to -40 °C. 120 ml of dilute hydrochloric acid (concentration: 1 mol / L) was added to quench the reaction. The mixture was filtered, washed with petroleum ether, and the obtained solid was purified by recrystallization with toluene to obtain white powder M1.

[0244] <Preparation of Intermediate M2>

[0245] 100 mmol of M1, 270 ml of glacial acetic acid and 70 ml of hydrochloric acid were added to a reaction flask, and the reaction was carried out at 130 °C for 1 h. After the reaction was completed, the reaction was stopped, and the reactants were heated to room temperature. The mixture was filtered, washed with aqueous sodium carbonate solution and then with n-hexane. The obtained solid was purified by recrystallization with toluene to obtain white powder compound M2.

[0246] <Preparation of Compound A-40>

[0247] 100 mmol of M2, 100 mmol of M3, 28.83 g (300 mmol) of sodium tert-butoxide and 800 ml of xylene were added to a reaction flask, and 1 mol% of Pd(dba)2 was added. 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, and the mixture was filtered and washed with water. The obtained solid was purified by recrystallization with toluene to obtain white powder compound A-42. Among them, the addition amount of Pd(dba)2 was 1 mol% of M2.

[0248] The HPLC purity of the prepared compound A-42 was 99.9%.

[0249] 1H NMR (300 MHz, Chloroform-d) 8.10 - 7.90 (m, 5H), 7.60 - 7.37 (m, 8H), 7.28 - 7.10 (m, 16H).

[0250] Synthesis Example 10: Synthesis of Compound A-43

[0251]

[0252] <Preparation of Intermediate M2> was the same as that in Synthesis Example 3.

[0253] <Preparation of Intermediate M1>

[0254] Under nitrogen protection, 100 mmol of F-17, 250 ml of THF were added to a reaction flask, and 115 ml of sec-butyllithium was added. The mixture was kept at -70 °C for 1 h, then 100 mmol of F-16 was added, and the reaction was carried out at -70 °C for 1 h. After the reaction was completed, the reaction was stopped, and the reactants were warmed to -40 °C. 120 ml of dilute hydrochloric acid (concentration 1 mol / L) was added to quench the reaction. The mixture was filtered, washed with petroleum ether, and the obtained solid was purified by recrystallization with toluene to obtain white powder M1.

[0255] <Preparation of Intermediate M3>

[0256] 100 mmol of M1, 270 ml of glacial acetic acid and 70 ml of hydrochloric acid were added to a reaction flask, and the reaction was carried out at 130 °C for 1 h. After the reaction was completed, the reaction was stopped, and the reactants were warmed to room temperature. The mixture was filtered, washed with aqueous sodium carbonate solution and then with n-hexane. The obtained solid was purified by recrystallization with toluene to obtain white powder compound M3.

[0257] <Preparation of Compound A-43>

[0258] 100 mmol of M3, 100 mmol of M2, 28.83 g (300 mmol) of sodium tert-butoxide, 800 ml of xylene were added to a reaction flask, and 1 mol% of Pd(dba)2 was added. 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, and the mixture was filtered and washed with water. The obtained solid was purified by recrystallization with toluene to obtain white powder compound A-43. Among them, the addition amount of Pd(dba)2 was 1 mol% of M3.

[0259] The HPLC purity of the prepared compound A-43 was 99.8%.

[0260] 1H NMR (300 MHz, Chloroform-d) 8.33 - 7.81 (m, 5H), 7.90 - 7.81 (m, 3H), 7.55 - 7.37 (m, 12H), 7.30 - 7.14 (m, 8H), 1.33 (m, 9H).

[0261] For other compounds of this application, appropriate raw materials can be selected for synthesis according to the ideas of Synthesis Example 1 to Synthesis Example 8 above, or any other appropriate methods and raw materials can be selected for synthesis.

[0262] Example 1

[0263] The glass substrate coated with an ITO transparent conductive layer with a thickness of 150 nm 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 all moisture is removed, cleaned with ultraviolet light and ozone, and bombarded with a low-energy cation beam on the surface.

[0264] Then, place the above-mentioned glass substrate with a reflective anode in a vacuum chamber, evacuate to less than 10 -5 Torr, and vacuum deposit a 10-nm hole injection layer on the above anode layer film. The material of the hole injection layer includes a hole transport material HT-21 and a p-type dopant p-3, and co-evaporation is carried out using a multi-source co-evaporation method. Among them, the evaporation rate of the hole injection layer material HT-21 is adjusted to 0.1 nm / s, and the evaporation rate of the p-type dopant p-3 is 3% of the evaporation rate of the hole injection layer material HT-11.

[0265] Then, vacuum deposit a 140-nm hole transport layer on the hole injection layer. Among them, the hole transport material is HT-32, and the evaporation rate is 0.1 nm / s.

[0266] Then, vacuum deposit a 5-nm electron blocking layer on the hole injection layer. Among them, the electron blocking layer material is EB-1, and the evaporation rate is 0.1 nm / s.

[0267] Then, vacuum deposit a 20-nm light-emitting layer on the electron blocking layer. The light-emitting layer includes a host material BH-5 and a guest material BD-10, and co-evaporation is carried out using a multi-source co-evaporation method. The evaporation rate of the host material BH-5 is adjusted to 0.1 nm / s, and the evaporation rate of the guest material BD-10 is 3% of the evaporation rate of the host material BH-5.

[0268] Then, vacuum deposit a 5-nm hole blocking layer on the light-emitting layer. Among them, the hole blocking layer material is ET-63, and the evaporation rate is 0.1 nm / s.

[0269] Then, vacuum deposit a 35-nm electron transport layer on the hole blocking layer. The electron transport layer contains an electron transport material ET-61 and an n-type dopant n-1, and the content of the n-type dopant is 50 mol%.

[0270] Then, vacuum deposit a 1-nm ytterbium (Yb) as an electron injection layer on the electron transport layer, and the evaporation rate is 0.1 nm / s.

[0271] Then, deposit a 15-nm aluminum layer as a cathode on the electron injection layer, and the evaporation rate is 1 nm / s.

[0272] Then, a first light extraction layer with a thickness of 15 nm is vacuum-evaporated on the cathode electrode. The material of the first light extraction layer is A-3, and the evaporation rate is 1 nm / s.

[0273] Finally, a second light extraction layer with a thickness of 50 nm is vacuum-evaporated on the first light extraction layer. The material of the second light extraction layer is C-1, and the evaporation rate is 1 nm / s.

[0274] The organic electroluminescent device of this embodiment is a blue organic electroluminescent device.

[0275] Examples 2 to 10

[0276] Except that compounds A-4, A-6, A-14, A-16, A33, A-35, A40, A-42, and A-43 are used to replace compound A-3 in sequence, the rest is the same as in Example 1.

[0277] Example 11

[0278] Except that the light-emitting layer includes the host material GPH-81 and the guest material GD01, and the organic electroluminescent device is a green organic electroluminescent device, the rest is the same as in Example 1.

[0279] Example 12

[0280] Except that the light-emitting layer includes the host material RH-10 and the guest material RPD-1, and the organic electroluminescent device is a red organic electroluminescent device, the rest is the same as in Example 1.

[0281] Comparative Examples 1 to 4

[0282] Except that compounds D-1 to D-4 are used to replace compound A-3 in sequence, the rest is the same as in Example 1.

[0283]

[0284] Comparative Example 5

[0285] Except that compound D-1 is used to replace compound A-3, the rest is the same as in Example 7.

[0286] Comparative Example 6

[0287] Except that compound D-1 is used to replace compound A-3, the rest is the same as in Example 8.

[0288] Comparative Example 7

[0289] Except that the light extraction layer prepared by the following <Preparation of Light Extraction Layer> is used to replace the first light extraction layer and the second light extraction layer, the rest is the same as in Example 1.

[0290] <Preparation of Light Extraction Layer>

[0291] A light extraction layer with a thickness of 65 nm is vacuum-evaporated on the cathode electrode. The material of the light extraction layer is C-1, and the evaporation rate is 1 nm / s.

[0292] Comparative Example 8

[0293] Except that the light-emitting layer includes a host material GPH-81 and a guest material GD01, and the organic electroluminescent device is a green organic electroluminescent device, the rest is the same as Comparative Example 7.

[0294] Comparative Example 9

[0295] Except that the light-emitting layer includes a host material RH-10 and a guest material RPD-1, and the organic electroluminescent device is a green organic electroluminescent device, the rest is the same as Comparative Example 7.

[0296] The performance parameters of each example and comparative example are shown in Table 1 and Table 2.

[0297] Table 1

[0298]

[0299] Referring to Table 1, the refractive indices of different light extraction materials at the same wavelength have certain differences. The compounds provided in this application for the light extraction material have lower refractive indices for blue light, green light, and red light than those of Compound D-1, Compound D-2, Compound D-3, or Compound D-4 in Comparative Examples 1 to 9. This shows that compared with the low refractive index layer materials in the prior art, the compounds provided in this application for the light extraction material have lower refractive indices and are more suitable for use as the low refractive index layer material in a bilayer structure. Among Compounds D-1 to D-4, at least one phenylene group connected to N is para-substituted or meta-substituted. The steric hindrance of the molecular structure of the above compounds is relatively low, the space tends to be planar, and the packing density between compound molecules is large, resulting in a relatively high refractive index when used as the light extraction layer. In the compounds provided in this application, at least one phenylene group connected to N is ortho-substituted. The steric hindrance of the molecular structure of the compound is high, and it has a different spatial configuration from Compounds D-1 to D-4. The spatial structure tends to be three-dimensional, which can reduce the packing density between compound molecules, is beneficial to increasing the propagation rate of light in the medium, that is, can reduce the ratio of the propagation rates of light in vacuum and in the medium. Therefore, the compounds provided in this application have lower refractive indices when used as the light extraction layer. In addition, the compounds provided in this application for the light extraction material have lower refractive indices for blue light, green light, and red light than the known high refractive index material Compound C-1 in the art, and the difference in refractive indices between the two is more than 0.3.

[0300] Table 2

[0301]

[0302] Note: "-" in Table 2 indicates the absence of the parameter.

[0303] The organic electroluminescent devices of Examples 1 to 12 and Comparative Examples 1 to 6 include a first light extraction layer with a low refractive index and a second light extraction layer with a high refractive index. Among them, the first light extraction layer of Examples 1 to 12 contains the compound of the present application as the light extraction material, and the first light extraction layer of Comparative Examples 1 to 6 contains Compound D-1, Compound D-2, Compound D-3, or Compound D-4 as the light extraction material. The second light extraction layer of Examples 1 to 12 and Comparative Examples 1 to 6 contains Compound C-1 as the light extraction material. Referring to Table 2, when the second light extraction layer is the same, the color coordinates (CIEx value and CIEy value) of the blue light device, green light device, and red light device are the same or similar, indicating that their emission colors are the same or similar. Moreover, the current efficiency of the green organic electroluminescent device and red organic electroluminescent device containing the compound of the present application is higher, and the blue light index of the blue organic electroluminescent device containing the compound of the present application is higher, indicating that the organic electroluminescent device containing the compound provided by the present application has better luminous performance.

[0304] Referring to Table 2, when the light extraction layers have the same thickness, the organic electroluminescent devices provided in the examples of the present application include a first light extraction layer and a second light extraction layer. The first light extraction layer contains the compound of the present application as the light extraction material, and the second light extraction layer contains Compound C-1 as the light extraction material. For the organic electroluminescent devices of Comparative Examples 7 to 9, their light extraction layer is a single-layer structure, and the light extraction layer contains Compound C-1 as the light extraction material. The CIEx value and CIEy value of the blue light devices with a double-layer structure light extraction layer containing the compound of the present application obtained in Examples 1 to 10 are the same or similar to those of Comparative Examples 1 to 4, indicating that their emission colors are the same or similar. Moreover, the blue light devices of Examples 1 to 10 have a higher blue light index. The CIEx value and CIEy value of the green light device with a double-layer structure light extraction layer containing the compound of the present application obtained in Example 11 are the same or similar to those of Comparative Example 5, indicating that their emission colors are similar. The CIEx value and CIEy value of the red light device with a double-layer structure light extraction layer containing the compound of the present application obtained in Example 12 are the same or similar to those of Comparative Example 6, indicating that their emission colors are similar. Moreover, the green light device obtained in Example 11 and the red light device obtained in Example 12 of the present application have a higher current efficiency, indicating that the organic electroluminescent device with a double-layer structure light extraction layer containing the compound of the present application has better luminous performance.

[0305] It should be noted that in this text, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements not only includes those elements, but also includes other elements not expressly listed, or further includes elements inherent to such process, method, article or device.

[0306] Each embodiment in this specification is described in a related manner. For the same or similar parts among the embodiments, reference can be made to each other, and the differences between each embodiment and other embodiments are emphasized.

[0307] The above are only the preferred embodiments of the present application and are not used to limit the protection scope of the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present application are included in the protection scope of the present application.

Claims

1. A light extraction material comprising at least one of the compounds having a structure shown in formula (I), wherein at least one of the substituents of the compound is a fluorine-containing substituent group; Among them, X is selected from O, S or CRbRc, and Rb and Rc are each independently selected from methyl and the following groups: R 1 ~R 4 Each independently selected from hydrogen, fluorine, trifluoromethyl, tert-butyl and the groups shown below, and R 1 ~R 4 are not simultaneously hydrogen: The red light refractive index of the light extraction material is ≤1.49, the green light refractive index is ≤1.52, and the blue light refractive index is ≤1.

55.

2. The light extraction material according to claim 1, wherein The compound is selected from the compounds shown in A-1 to A-15, A-21 to A-26, A-28 to A-34, A-36 to A-37, A-41 to A-43:

3. An organic electroluminescent device comprising a first light extraction layer and a second light extraction layer, wherein the refractive index of the first light extraction layer is less than that of the second light extraction layer, and the first light extraction layer contains at least one of the light extraction materials described in any one of claims 1-2.

4. A display device comprising the organic electroluminescent device described in claim 3.

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