Compound and electron blocking layer material, hole transport layer material and organic electroluminescent device comprising same

Abstract

The invention provides a compound and an electron blocking layer material, a hole transport layer material and an organic electroluminescent device containing the same, the structural formula of the compound is shown in a general formula (I) or a general formula (II), the compound is composed of a dibenzo six-membered heterocycle, a dibenzo heterocycle and an amino group, and under the synergistic effect of all groups, the compound can be used for preparing an organic electroluminescent device. The HOMO energy level of the obtained compound is at a proper level, the interface Gap with a luminescent layer can be reduced, hole injection is facilitated, so that holes and electrons are compounded at higher efficiency, and charge accumulation can be reduced. When the compound is used for an electron barrier layer material and a hole transport layer material of the organic light-emitting device, the voltage of the organic light-emitting device can be reduced, the efficiency is improved, and the service life is prolonged. # imgabs0 #

Description

Technical Field

[0001] The present application relates to the technical field of organic light-emitting devices, and particularly to a compound, an electron blocking layer material, a hole transport layer material, and an organic electroluminescent device containing the same. Background Art

[0002] With the development of technology, organic electroluminescent devices (OLEDs) have a series of advantages such as being all-solid-state, having a fast response speed, and a wide operating temperature range, and have received increasing attention from the academic and industrial circles. After years of continuous and active exploration, and further optimization of the device structure, process, and related materials, OLEDs have made great progress and have been industrialized at present. Although many compounds for OLED electron blocking layer materials have been reported in the past, the prepared OLEDs still have problems such as low efficiency and short lifespan. Therefore, new electron blocking layer materials still need to be developed. Summary of the Invention

[0003] The purpose of the present application is to provide a compound that can improve the efficiency and extend the lifespan of an organic electroluminescent device when used as a hole transport layer material and / or an electron blocking layer material. The specific technical solutions are as follows:

[0004] The first aspect of the present application provides a compound, and the structural formula of the compound is shown as general formula (I) or general formula (II):

[0005]

[0006] In general formula (I), Ar1 and Ar2 are respectively selected from formula (A1) and formula (A2);

[0007] In general formula (II), Ar1 and Ar5 are respectively selected from formula (A1) and formula (A2);

[0008]

[0009] Q1, Q2, and Q3 are each independently selected from C(R5)2, Si(R5)2, O, S, N(Ar6);

[0010] R1, R2, R3, R4, and R5 are each independently selected from H, D, T, unsubstituted or D-substituted C1-C39 alkyl, unsubstituted or D-substituted C3-C39 cycloalkyl, unsubstituted or D-substituted C6-C39 aryl, unsubstituted or D-substituted C5-C60 heteroaryl, unsubstituted or D-substituted C1-C39 alkoxy, unsubstituted or D-substituted C6-C39 arylamino, unsubstituted or D-substituted C3-C39 heterocycloalkyl; R1, R2, R3, R4, and R5 may be the same or different and two adjacent groups among R1, R2, R3, R4, and R5 may be joined to form a ring;

[0011] Ar3, Ar4, and Ar6 are each independently selected from unsubstituted or D-substituted C6-C39 aryl, unsubstituted or D-substituted C5-C60 heteroaryl, unsubstituted or D-substituted C6-C60 aryloxy;

[0012] L1 and L2 are each independently selected from a single bond, C6-C30 arylene, C6-C30 heteroarylene;

[0013] The heteroatoms in the heteroaryl and the heteroarylene are selected from O, S, N;

[0014] represents a connection site.

[0015] The second aspect of the present application provides a hole transport layer material, which comprises at least one of the compounds described in the first aspect of the present application.

[0016] The third aspect of the present application provides an electron blocking layer material, which comprises at least one of the compounds described in the first aspect of the present application.

[0017] The fourth aspect of the present application provides an organic electroluminescent device, which comprises at least one of the hole transport layer materials described in the second aspect of the present application, and / or at least one of the electron blocking layer materials described in the third aspect of the present application.

[0018] The fifth aspect of the present application provides a display device, which comprises the organic electroluminescent device described in the fourth aspect of the present application.

[0019] Advantages of the present application:

[0020] The present application provides a compound, a hole transport layer material, an electron blocking layer material, an organic electroluminescent device, and a display device including the same. The compound is composed of a dibenzo six-membered heterocycle, a dibenzo heterocycle, and an amino group. Under the synergistic action of each group, the HOMO energy level of the obtained compound is at an appropriate level, which can reduce the interface Gap with the light-emitting layer and is beneficial to the injection of holes. As a result, holes and electrons can recombine with higher efficiency, and charge accumulation can be reduced. By adjusting the HOMO energy level and accordingly adjusting the charge balance, when the obtained compound is used as an electron blocking layer material and a hole transport layer material for an organic electroluminescent device, the voltage of the organic electroluminescent device can be reduced, the efficiency can be improved, and the lifespan can be extended.

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

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for the description of the embodiments. 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 an organic electroluminescent device according to some embodiments of the present application;

[0024] Figure 2 It is a capacitance-voltage curve of the embodiments and comparative examples of the present application.

[0025] Reference numerals: 10 - substrate, 11 - first electrode, 12 - hole injection layer, 13 - hole transport layer, 14 - electron blocking layer, 15 - light-emitting layer, 16 - hole blocking layer, 17 - electron transport layer, 18 - electron injection layer, 19 - second electrode. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0026] The following will clearly and completely describe the technical solutions in the present application in conjunction with the embodiments and drawings of the present application. Obviously, the described embodiments are only some embodiments of the present application, rather than all embodiments. All other embodiments obtained by those skilled in the art based on the present application belong to the scope of protection of the present application.

[0027] The first aspect of the present application provides a compound, and the structural formula of the compound is shown as general formula (I) or general formula (II):

[0028]

[0029] In general formula (I), Ar1 and Ar2 are each independently selected from formula (A1) and formula (A2);

[0030] In general formula (II), Ar1 and Ar5 are each independently selected from formula (A1) and formula (A2);

[0031]

[0032] Q1, Q2 and Q3 are each independently selected from C(R5)2, Si(R5)2, O, S, N(Ar6);

[0033] R1, R2, R3, R4 and R5 are each independently selected from H, D, T, unsubstituted or D-substituted C1-C39 alkyl, unsubstituted or D-substituted C3-C39 cycloalkyl, unsubstituted or D-substituted C6-C39 aryl, unsubstituted or D-substituted C5-C60 heteroaryl, unsubstituted or D-substituted C1-C39 alkoxy, unsubstituted or D-substituted C6-C39 arylamino, unsubstituted or D-substituted C3-C39 heterocycloalkyl; R1, R2, R3, R4 and R5 may be the same or different and two adjacent groups among R1, R2, R3, R4 and R5 may be linked to form a ring;

[0034] Ar3, Ar4 and Ar6 are each independently selected from unsubstituted or D-substituted C6-C39 aryl, unsubstituted or D-substituted C5-C60 heteroaryl, unsubstituted or D-substituted C6-C60 aryloxy;

[0035] L1 and L2 are each independently selected from a single bond, C6-C30 arylene, C6-C30 heteroarylene;

[0036] The heteroatoms in the heteroaryl and the heteroarylene are selected from O, S, N;

[0037] represents the connection site.

[0038] Preferably, the general formula (I) is selected from the following structural formulas:

[0039]

[0040]

[0041] Preferably, the general formula (II) is selected from the following structural formulas:

[0042]

[0043] Preferably, R1, R2, R3, R4, and R5 are each independently selected from H, C1-C10 alkyl which is unsubstituted or substituted with D, C3-C12 cycloalkyl which is unsubstituted or substituted with D, C6-C20 aryl which is unsubstituted or substituted with D, C5-C20 heteroaryl which is unsubstituted or substituted with D, C1-C12 alkoxy which is unsubstituted or substituted with D, C6-C20 arylamino which is unsubstituted or substituted with D, C3-C12 heterocycloalkyl which is unsubstituted or substituted with D; R1, R2, R3, R4, and R5 may be the same or different and two adjacent groups among R1, R2, R3, R4, and R5 may be linked to form a ring.

[0044] Preferably, Ar3, Ar4, and Ar6 are each independently selected from C6-C20 aryl which is unsubstituted or substituted with D, C5-C20 heteroaryl which is unsubstituted or substituted with D, C6-C20 aryloxy which is unsubstituted or substituted with D.

[0045] Preferably, L1 and L2 are each independently selected from a single bond, C6-C12 arylene, C6-C12 heteroarylene.

[0046] More preferably, R1, R2, R3, R4, and R5 are each independently selected from H, C1-C6 alkyl which is unsubstituted or substituted with D, C3-C6 cycloalkyl which is unsubstituted or substituted with D, C6-C12 aryl which is unsubstituted or substituted with D, C5-C12 heteroaryl which is unsubstituted or substituted with D, C1-C6 alkoxy which is unsubstituted or substituted with D, C6-C12 arylamino which is unsubstituted or substituted with D, C3-C6 heterocycloalkyl which is unsubstituted or substituted with D; R1, R2, R3, R4, and R5 may be the same or different and two adjacent groups among R1, R2, R3, R4, and R5 may be linked to form a ring.

[0047] More preferably, Ar3, Ar4, and Ar6 are each independently selected from the following groups:

[0048]

[0049] wherein, * represents the connection site.

[0050] More preferably, L1 and L2 are each independently selected from a single bond, phenylene.

[0051] In some embodiments, the compounds represented by the general formula (I) are selected from the following compounds:

[0052]

[0053]

[0054]

[0055]

[0056]

[0057]

[0058]

[0059]

[0060]

[0061]

[0062]

[0063]

[0064]

[0065]

[0066]

[0067]

[0068]

[0069]

[0070]

[0071]

[0072]

[0073]

[0074]

[0075]

[0076]

[0077]

[0078]

[0079]

[0080]

[0081]

[0082]

[0083]

[0084]

[0085]

[0086]

[0087]

[0088]

[0089]

[0090]

[0091]

[0092]

[0093]

[0094]

[0095]

[0096]

[0097]

[0098]

[0099]

[0100]

[0101]

[0102]

[0103]

[0104]

[0105]

[0106]

[0107]

[0108] In some embodiments, the compound represented by the general formula (II) is selected from the following compounds:

[0109]

[0110]

[0111]

[0112]

[0113]

[0114]

[0115]

[0116]

[0117]

[0118]

[0119]

[0120]

[0121]

[0122] The inventors have found through research that the compound provided by this application is composed of a dibenzo six-membered heterocycle, a dibenzo heterocycle, and an amino group. Among them, the dibenzo six-membered heterocycle, dibenzofuran / thiophene, and amino group are connected in the specific connection manner described in this application. Under the synergistic effect of each group, the HOMO energy level of the obtained compound is at an appropriate level, which can reduce the interface Gap with the light-emitting layer and is conducive to the injection of holes. As a result, holes and electrons can recombine with higher efficiency, and charge accumulation can be reduced. By adjusting the HOMO energy level and accordingly adjusting the charge balance, when the obtained compound is used as the electron blocking layer material and hole transport layer material of an organic light-emitting device, the voltage of the organic light-emitting device can be reduced, the efficiency can be improved, and the lifespan can be extended. Among them, the compound composed of a dibenzo six-membered heterocycle, carbazole, and an amino group has a deeper HOMO energy level. When used as a green light electron blocking layer (GP), a better cyclic voltammetry (CV) curve can be obtained, and it is suitable as the electron blocking layer of a blue organic light-emitting device. The organic light-emitting device prepared with this compound has a low voltage and thus low power consumption.

[0123] The second aspect of this application provides a hole transport layer material, which includes at least one of the compounds described in the first aspect of this application. When at least one of the compounds provided in the first aspect of this application is used as the hole transport layer material, it is conducive to the injection of holes, so that holes and electrons can recombine with higher efficiency, charge accumulation can be reduced, and an OLED device with a small voltage rise, high efficiency, and long lifespan can be obtained.

[0124] The third aspect of this application provides an electron blocking layer material, which includes at least one of the compounds described in the first aspect of this application. When at least one of the compounds provided in the first aspect of this application is used as the electron blocking layer material, it can effectively block the spillage of excitons, and an OLED device with a small voltage rise, high efficiency, and long lifespan can be obtained.

[0125] The fourth aspect of this application provides an organic light-emitting device, which includes at least one of the hole transport layer materials described in the second aspect of this application, and / or at least one of the electron blocking layer materials described in the third aspect of this application. The organic light-emitting device provided by this application has a lower voltage, higher current efficiency, and longer service life.

[0126] In the present application, there is no particular limitation on the type and structure of the organic electroluminescent device, and it can be organic electroluminescent devices of different types and structures known in the art, as long as the hole transport layer material and the electron blocking layer material provided in the present application can be used. The organic electroluminescent device includes an anode, a cathode, and one or more light-emitting units may be included between the anode and the cathode; each light-emitting unit includes: (1) a light-emitting layer (EML); (2) a hole transport region including at least one selected from a hole injection layer (HIL), a hole transport layer (HTL), and an electron blocking layer (EBL); and (3) an electron transport region including an electron transport layer (ETL) and at least one selected from a hole blocking layer (HBL) and an electron injection layer (EIL).

[0127] Specifically, the organic electroluminescent device of the present application may be a top-emitting structure light-emitting device. For example, as Figure 1 shown, on the substrate 10, there are sequentially included a first electrode (anode) 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, and a second electrode (cathode) 19.

[0128] The organic electroluminescent device of the present application may be a bottom-emitting structure light-emitting device. For example, on the substrate, there are sequentially included a first electrode (anode), a hole injection layer, a hole transport layer, an electron blocking layer, a light-emitting layer, a hole blocking layer, an electron transport layer, an electron injection layer, and a second electrode (cathode).

[0129] The organic electroluminescent device of the present application may also be a double-sided emitting structure light-emitting device. For example, on the substrate, there are sequentially included a first electrode (anode), a hole injection layer, a hole transport layer, an electron blocking layer, a light-emitting layer, a hole blocking layer, an electron transport layer, an electron injection layer, and a second electrode (cathode).

[0130] The present application has no particular limitation on the thickness of the above-mentioned each layer, as long as the object of the present application can be achieved. For example, the organic electroluminescent device may sequentially include on the substrate a first electrode (anode) (50 nm to 100 nm) made of a metal or a metal oxide, a hole injection layer (5 nm to 40 nm), a hole transport layer (30 nm to 130 nm), an electron blocking layer (5 nm to 80 nm), a light-emitting layer (15 nm to 80 nm), a hole blocking layer (5 nm to 20 nm), an electron transport layer (5 nm to 60 nm), an electron injection layer (0.5 nm to 3 nm), and a second electrode (cathode) (10 nm to 200 nm).

[0131] In this application, there is no particular limitation on the material of the substrate, and conventional substrates known in the art can be selected. For example, glass, polymer materials, and glass and polymer materials with thin-film transistor (TFT) components, etc.

[0132] In this application, there is no particular limitation on the material of the first electrode (anode electrode), and transparent conductive materials known in the art 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, etc. can also be selected. Organic conductive materials such as poly(3,4-ethylenedioxythiophene) (PEDOT), etc. can also be selected, or a multilayer structure of the above materials, etc.

[0133] In this application, there is no particular limitation on the material of the hole injection layer (HIL), and hole injection materials well-known in the art can be used. For example, the hole injection layer material can be:

[0134]

[0135] In this application, there is no particular limitation on the material of the hole transport layer (HTL), and hole transport materials known in the art can be selected. For example, the hole transport material can be:

[0136]

[0137] In this application, for the light-emitting layer, it can include a host material and a guest material, and there is no particular limitation on their specific materials, and materials known in the art can be selected. For example, when the light-emitting layer emits blue light, the host material can include but is not limited to BH, and the guest material can include but is not limited to BD:

[0138]

[0139] For example, when the light-emitting layer emits green light, the host material can include at least one of but is not limited to GH-1 and GH-2, and the guest material can include but is not limited to GD-1:

[0140]

[0141] For example, when the light-emitting layer emits red light, the host material can include but is not limited to RH-1, and the guest material can include but is not limited to GD-1:

[0142]

[0143] In this application, there is no particular limitation on the dosages of the host material and the guest material, and the dosages well-known to those skilled in the art can be used.

[0144] In this application, the material of the hole blocking layer (HBL) is not particularly limited, and hole blocking layer materials known in the art can be used. For example, the hole blocking material can be:

[0145]

[0146] In this application, the material of the electron transport layer (ETL) is not particularly limited, and electron transport materials known in the art can be used. For example, the electron transport material can be:

[0147]

[0148] In this application, the material of the electron injection layer (EIL) is not particularly limited, and electron injection materials well-known in the art can be used. For example, the electron injection material can be:

[0149]

[0150] In this application, the material of the second electrode (cathode) is not particularly limited, and electron injection materials well-known in the art can be used. For example, the second electrode (cathode) material can be selected from at least one of materials such as Al, Mg, Ag, Mg:Ag, etc.

[0151] This application does not particularly limit the preparation method of the organic electroluminescent device, and any method well-known in the art can be adopted. For example, it can include but is not limited to the following steps:

[0152] (1) Clean the substrate coated with the first electrode (anode), and perform cleaning by a combination of one or several methods such as chemical washing, water washing, brush, high-pressure water washing, air knife, UV irradiation, nitrogen treatment, oxygen treatment, etc., and then perform heat treatment;

[0153] (2) Vacuum deposit a hole injection material on the first electrode (anode) as the hole injection layer;

[0154] (3) Vacuum deposit a hole transport material on the hole injection layer as the hole transport layer;

[0155] (4) Vacuum deposit an electron blocking material on the hole transport layer as the electron blocking layer;

[0156] (5) Vacuum deposit a light-emitting layer on the electron blocking layer, and the light-emitting layer contains a host material and a guest material;

[0157] (6) Vacuum deposit a hole blocking material on the light-emitting layer as the hole blocking layer;

[0158] (7) Vacuum deposit an electron transport material on the hole blocking layer as the electron transport layer;

[0159] (8) Vacuum deposit an electron injection material on the electron transport layer as the electron injection layer;

[0160] (9) Vacuum deposit a cathode material on the electron injection layer as the second electrode (cathode).

[0161] The above only describes the structure of a typical organic electroluminescent device and its preparation method. It should be understood that this application is not limited to this structure. The hole transport layer material and electron blocking layer material of this application can be used in organic electroluminescent devices of any structure, and any preparation method well known in the art can be used to prepare the organic electroluminescent device.

[0162] The fifth aspect of this application provides a display device, which includes the organic electroluminescent device described in the fourth aspect of this application.

[0163] The display device described in this application includes but is not limited to displays, televisions, tablet computers, mobile communication terminals, etc.

[0164] The specific compounds provided in this application can all be further reacted with the halides, especially the bromides (C) formed in this way, by methods familiar to those of ordinary skill in the art, such as C-C coupling (such as Suzuki, Negishi, Yamamoto, Grignard Cross, Stille, Heck coupling, etc.) or C-N coupling (such as Buchwald or Ullmann coupling, silylation, phosphination, boration, polycondensation, etc.).

[0165] The reaction general formula is as follows:

[0166]

[0167] The following gives a specific synthesis method, and the specific synthesis route is not limited to this.

[0168] Synthesis Example 1: Synthesis of Compound 1

[0169]

[0170] Step 1: Under nitrogen, the starting material (1-I) 1-bromobenzo[B,D]furan-2-amine (CAS: 667937-51-1) (10 g, 38.2 mmol), the starting material (1-II) dibenzo[b,e][1,4]dioxin-2-ylboronic acid (CAS: 868380-13-6) (10.15 g, 44.5 mmol), and potassium carbonate (11.86 g, 85.80 mmol) were added to a dry three-necked flask. Toluene (100 ml), ethanol (35 ml), and deionized water (35 ml) were added and heated with stirring until dissolved. Tetrakis(triphenylphosphine)palladium (CAS: 14221-01-3) (0.74 g, 0.64 mmol) was then added and heated to reflux. The reaction was monitored by thin layer chromatography (TLC). After the reaction, the product was washed with water, extracted with dichloromethane, and the solvent was removed by rotary evaporation. Then, n-heptane and dichloromethane (volume ratio 10:1) were used to remove the solvent by rotary evaporation on a silica gel column. The obtained light yellow solid was recrystallized, filtered, and dried in vacuo to obtain the product, i.e., intermediate (1-III) (yield: 78%, purity: 98% (10.81 g); MS [M+H] +: 365.83).

[0171] Step 2: Dissolve the intermediate (1-III) (7.3 g, 20 mmol) and the reactant (1-IV) 4-bromobiphenyl (CAS: 92-66-0) (9.79 g, 42 mmol) in toluene solvent and stir under nitrogen to reflux. Then, sodium tert-butoxide, 2-dicyclohexylphosphine-2',4',6'-triisopropylbiphenyl (X-phos), and tris(dibenzylideneacetone)dipalladium (Pd2(dba)3) were added in sequence and heated under reflux. The reaction was allowed to react overnight. After the reaction was completed and the temperature was cooled to room temperature, distilled water was added to the reaction solution and the reaction solution was extracted with an organic solvent, dichloromethane (DCM). The extracted organic layer was then dried over magnesium sulfate, and the solvent was removed using a rotary evaporator. The remaining material was purified by column chromatography, and the solvent was removed using a rotary evaporator. The solid was recrystallized from toluene / n-heptane to obtain the product, compound 1 (purity: 99.63%, yield: 86%, MS [M+H] +: 670.5, C 48 H 31 NO3).

[0172] With reference to the synthesis process of Synthesis Example 1, the raw materials, products, yields, purities and mass spectrometry data in the synthesis process of compounds 2-13, 41 and 42 are shown in Synthesis Example 2-15, respectively.

[0173] Synthesis Example 2: Synthesis of Compound 2

[0174]

[0175] 4-iodo-2-dibenzofuranamine

[0176] CAS: 1402853-24-0

[0177]

[0178] Yield of intermediate (2-III): 78.5%; Purity: 98.7%; MS [M+H]+: 366.19.

[0179] Yield of compound 2: 72.5%; Purity: 99.67%; MS [M+H]+: 670.4.

[0180] Synthesis Example 3: Synthesis of Compound 3

[0181]

[0182] 3-Bromo-2-dibenzofuranamine

[0183] CAS: 876475-71-7

[0184]

[0185] Yield of intermediate (3-III): 76.8%; Purity: 98.6%; MS [M+H]+: 366.11.

[0186] Yield of compound 3: 73%; Purity: 99.82%; MS [M+H]+: 670.2.

[0187] Synthesis Example 4: Synthesis of Compound 4

[0188]

[0189] 2-Bromo-3-dibenzofuranamine

[0190] CAS: 83660-06-4

[0191]

[0192] Yield of intermediate (4-III): 78.3%; Purity: 98.1%; MS [M+H]+: 366.13.

[0193] Yield of compound 4: 76.1%; Purity: 99.97%; MS [M+H]+: 670.7.

[0194] Synthesis Example 5: Synthesis of Compound 5

[0195]

[0196] 2-Bromo-4-dibenzofuranamine

[0197] CAS: 186821-98-7

[0198]

[0199] Yield of intermediate (5-III): 78.5%; Purity: 98.2%; MS [M+H]+: 366.09.

[0200] Yield of compound 5: 81%; Purity: 99.8%; MS [M+H]+: 670.5.

[0201] Synthesis Example 6: Synthesis of Compound 6

[0202]

[0203] 1-Bromo-9,9-dimethyl-9H-fluoren-2-amine

[0204] CAS: 2254099-03-9

[0205]

[0206] Yield of intermediate (6-III): 76.35%; Purity: 98.2%; MS [M+H]+: 392.58. Yield of compound 6: 73%; Purity: 99.56%; MS [M+H]+:696.5.

[0207] Synthesis Example 7: Synthesis of Compound 7

[0208]

[0209] 9,9-Dimethyl-2-bromofluorene

[0210] CAS: 28320-31-2

[0211] Yield of intermediate (7-V): 61.3%; Purity: 98.67%; MS [M+H]+: 518.3. Yield of compound 7: 71.7%; Purity: 99.67%; MS [M+H]+: 709.2.

[0212] Synthesis Example 8: Synthesis of Compound 8

[0213]

[0214]

[0215] 9,9-Dimethyl-2-bromofluorene

[0216] CAS: 28320-31-2

[0217] Yield of intermediate (8-V): 62.9%; Purity: 98.21%; MS [M+H]+: 518.2. Yield of compound 8: 70%; Purity: 99.82%; MS [M+H]+: 710.4.

[0218] Synthesis Example 9: Synthesis of Compound 9

[0219]

[0220] 9,9-Dimethyl-2-bromofluorene

[0221] CAS: 28320-31-2

[0222] Yield of intermediate (9-V): 62.5%; Purity: 97.7%; MS [M+H]+: 516.1. Yield of compound 9: 70.6%; Purity: 99.97%; MS [M+H]+: 710.2.

[0223] Synthesis Example 10: Synthesis of Compound 10

[0224]

[0225] 9,9-Dimethyl-2-bromofluorene

[0226] CAS: 28320-31-2

[0227] Yield of intermediate (10-V): 67.1%; Purity: 97.23%; MS [M+H]+: 518.1. Yield of compound 10: 71%; Purity: 99.8%; MS [M+H]+: 710.5.

[0228] Synthesis Example 11: Synthesis of Compound 11

[0229]

[0230] 9,9-Dimethyl-2-bromofluorene

[0231] CAS: 28320-31-2

[0232] Yield of intermediate (11-V): 66.2%; Purity: 96.97%; MS [M+H]+: 517.9. Yield of compound 11: 73%; Purity: 99.56%; MS [M+H]+: 710.4.

[0233] Synthesis Example 12: Synthesis of Compound 12 <0,

[0234]

[0235] 9,9-Dimethyl-2-bromofluorene

[0236] CAS: 28320 - 31 - 2

[0237] Yield of intermediate (12 - Ⅴ): 66.1%; Purity: 97.67%; MS[M + H]+: 544.03. Yield of compound 12: 71%; Purity: 99.56%; MS[M + H]+: 737.1.

[0238] Synthesis Example 13: Synthesis of Compound 13

[0239]

[0240] CAS: 952431 - 31 - 1

[0241] The reaction conditions, solvents, catalysts, etc. are the same as those in the second step of Synthesis Example 1.

[0242] Yield of compound 13: 67%; Purity: 99.53%; MS[M + H]+: 746.1.

[0243] Synthesis Example 14: Synthesis of Compound 41

[0244] Except that raw material (1 - II) is replaced by raw material (41 - II) to obtain compound 41 by reaction, the rest is the same as Synthesis Example 1.

[0245]

[0246] CAS: 1246021 - 99 - 7

[0247] Yield of compound 41: 65%; Purity: 99.47%; MS[M + H]+: 819.7.

[0248] Synthesis Example 15: Synthesis of Compound 42

[0249] Except that raw material (1 - II) is replaced by raw material (42 - II) to obtain compound 42 by reaction, the rest is the same as Synthesis Example 1.

[0250]

[0251] CAS: 1801610 - 26 - 3

[0252] Yield of compound 42: 69%; Purity: 99.76%; MS[M + H]+: 721.9.

[0253] Other compounds of this application can be synthesized by selecting appropriate raw materials according to the ideas of the above - mentioned Synthesis Examples 1 - 15, or any other appropriate methods and raw materials can also be selected for synthesis.

[0254] The material physical properties of the compounds 1-42 of the present application and the prior art compounds D1-D3 were measured as follows:

[0255] (1) Measurement of HOMO energy level, LUMO energy level and Eg:

[0256] For the measurement of the HOMO energy level and LUMO energy level in the present application, a photoelectron spectrophotometer AC3 was used. By irradiating the sample with ultraviolet light, the kinetic energy of the secondary electrons at the low-energy end was measured, and then the HOMO energy level position of the material was determined. Specifically, when the sample was irradiated with ultraviolet light of a specific wavelength, a part of the energy was used to overcome the electron binding energy, and the remaining part enabled the electrons to obtain kinetic energy. By analyzing the positions of these physical parameters in the spectrum, the HOMO energy level of the material could be obtained. The absorption spectrum of the test material was measured, and the intersection of the rising tangent of the absorption spectrum and the abscissa was divided by 1240 to obtain Eg, and LUMO = HOMO - Eg.

[0257] (2) Measurement of hole recombination energy (ROE):

[0258] In the present application, quantum chemical calculation methods, especially the density functional theory (DFT) method, were relied on to explore the electron transfer process and measure the hole recombination energy.

[0259] (3) Measurement of mass spectrometry data:

[0260] It was tested using a matrix-assisted laser desorption / ionization time-of-flight mass spectrometer.

[0261] Among the compounds measured, the structures of compounds 1-13, 41 and 42 are as shown in Synthesis Examples 1-15, and the structures of D1-D3 and compounds 14-40 are as follows:

[0262]

[0263]

[0264]

[0265] The measured results are shown in Table 1.

[0266] Table 1

[0267]

[0268]

[0269] Hereinafter, examples and comparative examples will be given to more specifically illustrate the embodiments of the present application. Various tests and evaluations were carried out according to the following methods.

[0270] Example 1-1

[0271] Clean and dry the ITO substrate; sequentially start depositing the HIL material, HTL material, and EBL material on the anode (first electrode); then deposit the emitting layer (EML); deposit the HBL material, ETL material, and EIL material on the emitting layer; and then deposit the cathode (second electrode) to obtain a green organic light-emitting device.

[0272] The structure of the green organic light-emitting device is as follows: the material of the first electrode is ITO; the thickness of the HIL is 10 nm; the thickness of the HTL is 110 nm; the thickness of the EBL is 40 nm; the material of the EML is composed of GH-1 and GD-1, and the thickness of the GD-1 evaporation coating layer accounts for 8% of the total thickness of the emitting layer, and the thickness of the EML is 30 nm; the thickness of the HBL is 5 nm; the thickness of the ETL is 30 nm; the thickness of the EIL is 1 nm; the material of the second electrode is Mg and Ag, and the thickness of the second electrode is 13 nm.

[0273] Among them, the material of the HIL is PD, the material of the HTL is HT-1, the material of the EBL is Compound 1 of this application, the material of the EML is GH-1 and GD-1, the structural formulas of the materials of the HBL and ETL are as shown below, and the material of the EIL is Liq.

[0274]

[0275] Examples 1-2 to 1-8

[0276] Except for selecting the material of the EBL according to Table 2, the rest are the same as Example 1-1.

[0277] Example 1-9

[0278] Except for setting the EBL as a double layer and selecting the material of the EBL according to Table 2, the rest are the same as Example 1-1. Among them, the material of the EBL close to the HTL side is Compound 7 with a thickness of 10 nm, and the material of the EBL close to the EML side is Compound 4 with a thickness of 30 nm.

[0279] Example 1-10

[0280] Except for setting the EBL as a double layer and selecting the material of the EBL according to Table 2, the rest are the same as Example 1-1. Among them, the material of the EBL close to the HTL side is Compound 7 with a thickness of 10 nm, and the material of the EBL close to the EML side is Compound 4 with a thickness of 30 nm.

[0281] Examples 2-1 to 2-8

[0282] Except that the material of the EML is replaced with BH and BD, the thickness of the evaporated coating layer of BD accounts for 2% of the total thickness of the light-emitting layer, and the materials of the EBL are selected according to Table 4 to prepare the blue organic electroluminescent device, the rest is the same as in Example 1-1. The structures of BH and BD are shown below.

[0283]

[0284] Examples 2-9 to 2-13

[0285] Except that the materials of the HTL and EBL are selected according to Table 4, the rest is the same as in Example 2-1.

[0286] Comparative Examples 1-1 to 1-3

[0287] Except that the material of the EBL is adjusted according to Table 2, the rest is the same as in Example 1-1.

[0288] Comparative Example 2-1

[0289] Except that the materials of the HTL and EBL are selected according to Table 4, the rest is the same as in Example 2-1.

[0290] Testing equipment and methods:

[0291] The prepared green organic electroluminescent devices are subjected to performance measurement. The measurement method is as follows: at the same brightness, use a digital source meter and a luminance meter to measure the driving voltage (V), current efficiency (Eff.), and device lifetime (LT95) of different groups of green organic electroluminescent devices. Specifically, measure the voltage corresponding to a current density of 15 mA / cm 2 which is the driving voltage V, and the corresponding efficiency is the current efficiency; the lifetime test of LT95 is as follows: use a luminance meter at a brightness of 1000 nit, keep the current constant, and measure the time when the brightness of the green organic electroluminescent device drops to 950 nit, in hours. The measurement results are calculated with the results of Comparative Example 1-1 as 100%, and the relative results of other groups of green organic electroluminescent devices are calculated. The test results are shown in Table 2.

[0292] The prepared blue organic electroluminescent devices are subjected to performance measurement. The measurement method is as follows: at the same brightness, use a digital source meter and a luminance meter to measure the driving voltage (V), blue light efficiency (BI), and device lifetime (LT95) of different groups of blue organic electroluminescent devices. Specifically, measure the voltage corresponding to a current density of 15 mA / cm 2The voltage corresponding to the time is the driving voltage V, and the corresponding efficiency is the current efficiency. Dividing the current efficiency by the color coordinate CIEy represents the efficiency of the blue light (BI). The life test of LT95 is as follows: Using a luminance meter at a luminance of 1000 nit, keeping the current constant, measure the time when the luminance of the blue organic electroluminescent device drops to 950 nit, and the unit is hours. The measurement results are all calculated with the result of Comparative Example 2-1 as 100%, and the relative results of other groups of blue organic electroluminescent devices are calculated. The test results are shown in Table 4.

[0293] Table 2

[0294]

[0295]

[0296] According to the test results, Compounds 1, 2, 3, 4, 6, and 7 of the present application are composed of dibenzo six-membered heterocycles, dibenzofuran, and amino groups. Among them, the introduction of dibenzofuran can have a lower voltage compared with Comparative Compounds D-1 to D-3, and the life and efficiency are improved. Moreover, the specific connection mode of the compounds in the present application makes the HOMO energy level of the material at an appropriate level, which can reduce the interface Gap with the EML and is beneficial to the injection of holes. As a result, holes and electrons can recombine with the fastest efficiency, reducing charge accumulation. Compounds of the 6th and 17th types of the present application are composed of dibenzo six-membered heterocycles, fluorene, and amino groups, which are similar in structure to Comparative Examples 1-1 to 1-3. However, the different connection sites lead to completely different physical properties of the compounds. It can be seen from the physical property data in Table 1 that the connection mode of the present application is at least one connection at the 1st position of fluorene. It is speculated that this connection site makes the material present a special twisted structure, thus making the compound have completely different physical properties. Furthermore, the T1 energy levels of Compound D3 and Compound 17 are obtained through chemical calculations, as shown in Table 3.

[0297] Table 3

[0298] Material of the electron blocking layer T1 (eV) Examples 1-8 Compound 17 2.77 Comparative Examples 1-3 D-3 2.54

[0299] It can be seen from Table 3 that it further proves that the compounds of the present application are suitable for the EBL layer, can effectively block the exciton overflow, and thus have higher efficiency and longer life.

[0300] As can be seen from Examples 1-1 to 1-8, Compound 13 in Examples 1-7 is composed of a dibenzo six-membered heterocycle, a carbazole class, and an amino group. Due to the introduction of carbazole in this type of compound, it has a deeper HOMO, which is more conducive to the injection into the EML. Therefore, the voltage is slightly lower than that of other examples. Examples 1-9 and 1-10 are double-layer green light EBMs. After the two materials are combined, lower voltage, higher efficiency, and longer lifespan can be obtained, and the CV performance is better. Furthermore, the compound of the present application has a relatively deeper HOMO, which actually causes the green organic light-emitting device of the present application to have a completely different CV curve (as Figure 2 shown), that is, the starting position of the CV peak is relatively backward, and it has a smaller Cmax (peak value). This will be conducive to the matching of RGB, with a better display effect and reduced trailing phenomenon.

[0301] Table 4

[0302]

[0303]

[0304] As can be seen from the device structures in Examples 2-1 to 2-12, the compound of the present application used as an electron blocking layer material and / or a hole transport layer material can also be used in blue organic light-emitting devices, and has the effects of reducing voltage, improving efficiency and lifespan. The compound of the present application can also be used as a hole transport layer material, and when combined with the electron blocking layer material of the present application, the efficiency of the organic light-emitting device can be further improved and its lifespan can be extended.

[0305] The above are only the preferred embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present application shall be included within the scope of protection of the present application.

Claims

1. A compound, the structural formula of which is shown as general formula (I) or general formula (II): In general formula (I), Ar1 and Ar2 are independently selected from formula (A1) and formula (A2); In general formula (II), Ar1 and Ar5 are independently selected from formula (A1) and formula (A2); Q1, Q2 and Q3 are each independently selected from C(R5)2, Si(R5)2, O, S, N(Ar6); R1, R2, R3, R4 and R5 are each independently selected from H, D, T, C1-C39 alkyl which is unsubstituted or substituted by D, C3-C39 cycloalkyl which is unsubstituted or substituted by D, C6-C39 aryl which is unsubstituted or substituted by D, C5-C60 heteroaryl which is unsubstituted or substituted by D, C1-C39 alkoxy which is unsubstituted or substituted by D, C6-C39 arylamino which is unsubstituted or substituted by D, C3-C39 heterocycloalkyl which is unsubstituted or substituted by D; R1, R2, R3, R4 and R5 can be the same or different and two adjacent groups among R1, R2, R3, R4 and R5 can be linked to form a ring; Ar3, Ar4 and Ar6 are each independently selected from C6-C39 aryl which is unsubstituted or substituted by D, C5-C60 heteroaryl which is unsubstituted or substituted by D, C6-C60 aryloxy which is unsubstituted or substituted by D; L1 and L2 are each independently selected from a single bond, C6-C30 arylene, C6-C30 heteroarylene; The heteroatoms in the heteroaryl and the heteroarylene are selected from O, S, N; Indicates the connection site.

2. The compound according to claim 1, wherein, The general formula (I) is selected from the following structural formulas:

3. The compound according to claim 1, wherein The general formula (II) is selected from the following structural formulas:

4. The compound according to claim 1, wherein, R1, R2, R3, R4 and R5 are each independently selected from H, C1-C10 alkyl which is unsubstituted or substituted by D, C3-C12 cycloalkyl which is unsubstituted or substituted by D, C6-C20 aryl which is unsubstituted or substituted by D, C5-C20 heteroaryl which is unsubstituted or substituted by D, C1-C12 alkoxy which is unsubstituted or substituted by D, C6-C20 arylamino which is unsubstituted or substituted by D, C3-C12 heterocycloalkyl which is unsubstituted or substituted by D; R1, R2, R3, R4 and R5 can be the same or different and two adjacent groups among R1, R2, R3, R4 and R5 can be linked to form a ring; Ar3, Ar4 and Ar6 are each independently selected from C6-C20 aryl which is unsubstituted or substituted by D, C5-C20 heteroaryl which is unsubstituted or substituted by D, C6-C20 aryloxy which is unsubstituted or substituted by D; L1 and L2 are each independently selected from a single bond, C6-C12 arylene, C6-C12 heteroarylene.

5. The compound according to claim 1, wherein R1, R2, R3, R4, and R5 are each independently selected from H, C1-C6 alkyl which is unsubstituted or substituted with D, C3-C6 cycloalkyl which is unsubstituted or substituted with D, C6-C12 aryl which is unsubstituted or substituted with D, C5-C12 heteroaryl which is unsubstituted or substituted with D, C1-C6 alkoxy which is unsubstituted or substituted with D, C6-C12 arylamino which is unsubstituted or substituted with D, C3-C6 heterocycloalkyl which is unsubstituted or substituted with D; R1, R2, R3, R4, and R5 may be the same or different and two adjacent groups among R1, R2, R3, R4, and R5 may be linked to form a ring; or, Ar3, Ar4, and Ar6 are each independently selected from the following groups: wherein, * represents the connection site; or, L1 and L2 are each independently selected from a single bond and phenylene.

6. The compound according to claim 1, wherein, The compound represented by the general formula (I) is selected from the following compounds:

7. The compound according to claim 1, wherein The compound represented by the general formula (II) is selected from the following compounds:

8. An electron blocking layer material, wherein, The electron blocking material includes at least one of the compounds described in any one of claims 1 to 7.

9. A hole transport layer material, wherein, The hole transporting material includes at least one of the compounds described in any one of claims 1 to 7.

10. An organic electroluminescent device, wherein, The organic electroluminescent device includes at least one of the electron blocking layer materials described in claim 8 and / or at least one of the hole transporting layer materials described in claim 9.

11. A display device, wherein, The display device includes the organic electroluminescent device described in claim 10.

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