A compound and its application

Abstract

The invention relates to a compound and application thereof. The compound has a structure shown in formula I. The compound uses a multi-conjugated fused ring carbazole structure as a parent core, and an electron-withdrawing group quinoxaline group or quinazoline group is substituted on N of the carbazole. The structure can improve the planarity of the molecule and reduce the carrier transmission barrier. When matched with a specific electron-withdrawing group, a device containing the compound has the advantages of low voltage and high efficiency. In addition, the molecule has a rigid structure of multi-conjugated fused rings, strong molecular chemical stability, excellent thermal stability, and good performance in the device. The life span is also shown.

Description

Technical Field

[0001] The invention relates to the technical field of organic electroluminescence, and in particular to a compound and application thereof. Background Art

[0002] In recent years, optoelectronic devices based on organic materials have become increasingly popular. The inherent flexibility of organic materials makes them very suitable for manufacturing on flexible substrates. Beautiful and cool optoelectronic products can be designed and produced according to demand, gaining unparalleled advantages over inorganic materials. Examples of such organic optoelectronic devices include organic light-emitting diodes (OLEDs), organic field-effect transistors, organic photovoltaic cells, organic sensors, etc. Among them, OLED has developed particularly rapidly and has achieved commercial success in the field of information display. OLED can provide highly saturated red, green, and blue colors. Full-color display devices made of OLEDs do not require additional backlight sources and have the advantages of brilliant colors, lightness, thinness, and softness.

[0003] The core of OLED devices is a thin film structure containing a variety of organic functional materials. Common functionalized organic materials include: hole injection materials, hole transport materials, hole blocking materials, electron injection materials, electron transport materials, electron blocking materials, luminescent host materials and luminescent guest (dyes), etc. When power is turned on, electrons and holes are injected and transported to the luminescent area respectively and recombine there, thereby generating excitons and emitting light.

[0004] People have developed a variety of organic materials, combined with various unique device structures, which can improve carrier mobility, regulate carrier balance, break through electroluminescence efficiency, and delay device attenuation. For quantum mechanical reasons, common fluorescent luminescent bodies mainly use singlet excitons generated when electrons and holes combine to emit light, and are still widely used in various OLED products. Some metal complexes, such as iridium complexes, can simultaneously use triplet excitons and singlet excitons to emit light, and are called phosphorescent luminescent bodies. Their energy conversion efficiency can be increased by up to four times that of traditional fluorescent luminescent bodies. Thermally excited delayed fluorescence (TADF) technology promotes the transformation of triplet excitons to singlet excitons. Without the use of metal complexes, triplet excitons can still be effectively utilized to achieve higher luminescence efficiency. Thermally excited sensitized fluorescence (TASF) technology uses materials with TADF properties to sensitize luminescent bodies through energy transfer, which can also achieve higher luminescence efficiency.

[0005] However, the existing red light host materials have the following problems: the carrier transmission barrier is high, a higher voltage is required, and the luminous efficiency and molecular structure stability are also poor.

[0006] Therefore, the industry urgently needs to develop new material systems to meet the ever-increasing demand for the optoelectronic performance and service life of OLED devices. Summary of the invention

[0007] One of the purposes of the present invention is to provide a compound, when the compound is applied to an organic electroluminescent device, the device has excellent photoelectric performance and service life.

[0008] To achieve this object, the present invention adopts the following technical solutions:

[0009] The present invention provides a compound having a structure shown in Formula I;

[0010]

[0011] In Formula I, the Y 1 , Y 2 , Y 3 , Y 4 , Y 5 , Y 6 , Y 7 , Y 8 , Y 9 , Y 10 , Y 11 , Y 12 , Y 13 , Y 14 , Y 15 and Y 16 Each independently selected from CH, CR 1 , CR 2 or one of N;

[0012] The R 1 One selected from substituted or unsubstituted C6-C30 (e.g., C10, C12, C14, C16, C18, C20, C26, C28, etc.) aryl, substituted or unsubstituted C3-C30 (e.g., C4, C6, C8, C12, C15, C18, C20, C23, C25, C28, etc.) heteroaryl, substituted or unsubstituted C6-C30 (e.g., C10, C12, C14, C16, C18, C20, C26, C28, etc.) arylamino, substituted or unsubstituted C3-C30 (e.g., C4, C6, C8, C12, C15, C18, C20, C23, C25, C28, etc.) heteroarylamino;

[0013] The R 2One selected from C1-C12 (e.g., C2, C3, C4, C5, C6, C7, C8, C9, C10, etc.) chain alkyl, C3-C12 (e.g., C4, C5, C6, C7, C8, C9, C10, etc.) cycloalkyl, C1-C12 (e.g., C2, C3, C4, C5, C6, C7, C8, C9, C10, etc.) alkoxy, halogen, cyano, nitro, hydroxyl, silane, and amino;

[0014] In Formula I, Ar has a structure shown in Formula II or Formula III;

[0015]

[0016] In Formula II, the L 1 One selected from a single bond, a substituted or unsubstituted C6-C30 (e.g., C10, C12, C14, C16, C18, C20, C26, C28, etc.) arylene, and a substituted or unsubstituted C3-C30 (e.g., C4, C6, C8, C12, C15, C18, C20, C23, C25, C28, etc.) heteroarylene;

[0017] In formula II, m is an integer from 0 to 5, such as 1, 2, 3, 4, etc.;

[0018] When m is an integer greater than or equal to 2, that is, there are two or more R substituted on the parent core 3 When these two or more R 3 They can be the same group or different groups. n and R 4 Similarly;

[0019] In Formula III, the L 2 One selected from substituted or unsubstituted C6-C30 (e.g., C10, C12, C14, C16, C18, C20, C26, C28, etc.) arylene, and substituted or unsubstituted C3-C30 (e.g., C4, C6, C8, C12, C15, C18, C20, C23, C25, C28, etc.) heteroarylene;

[0020] In formula III, n is an integer from 0 to 5, such as 1, 2, 3, 4, etc.;

[0021] In Formula II and Formula III, the R 3 and R 4Each is independently selected from substituted or unsubstituted C6-C30 (e.g., C10, C12, C14, C16, C18, C20, C26, C28, etc.) aryl, substituted or unsubstituted C3-C30 (e.g., C4, C6, C8, C12, C15, C18, C20, C23, C25, C28, etc.) heteroaryl, substituted or unsubstituted C1-C10 (e.g., C2, C3, C4, C5, C6, C7, C8, C9, C10, etc.) chain alkyl, substituted or unsubstituted C3-C10 ( For example, C3, C4, C5, C6, C7, C8, C9, C10, etc.) cycloalkyl, substituted or unsubstituted C1-C10 (for example, C2, C3, C4, C5, C6, C7, C8, C9, C10, etc.) alkoxy, halogen, cyano, nitro, hydroxyl, silanyl, amino, substituted or unsubstituted C6-C30 (for example, C4, C6, C8, C12, C15, C18, C20, C23, C25, C28, etc.) arylamino, substituted or unsubstituted C3-C30 heteroarylamino;

[0022] In formula II and formula III, * represents the access bond of the group;

[0023] When the above-mentioned groups have substituents, the substituents are selected from halogen, cyano, C1-C12 (e.g., C2, C3, C4, C5, C6, C7, C8, C9, C10, etc.) chain alkyl, C3-C12 cycloalkyl (e.g., C4, C5, C6, C7, C8, C9, C10, etc.), C1-C6 (e.g., C2, C3, C4, C5, etc.) alkoxy, C1-C6 (e.g., C2, C3, C4, C5, etc.) thioalkoxy, C6-C30 (e.g., C10, C12, C14, C16, C18, C20, C26, C28, etc.) arylamino, C3-C30 (e.g., C4 C6-C30 (e.g., C10, C12, C14, C16, C18, C20, C26, C28, etc.) heteroarylamino, C6-C30 (e.g., C10, C12, C14, C16, C18, C20, C26, C28, etc.) monocyclic aryl, C10-C30 condensed ring aryl, C3-C30 (e.g., C4, C6, C8, C12, C15, C18, C20, C23, C25, C28, etc.) monocyclic heteroaryl, C6-C30 (e.g., C10, C12, C14, C16, C18, C20, C26, C28, etc.) condensed ring heteroaryl, or a combination of at least two of them. The above-mentioned "substituted or unsubstituted" group may be substituted with one substituent or with multiple substituents. When there are multiple substituents, they may be selected from different substituents.

[0024] In the present invention, the heteroatom of the heteroaryl group is usually selected from N, O, and S.

[0025] In the present invention, the expression of a ring structure crossed by “—” indicates that the connection site is at any position on the ring structure that can form a bond.

[0026] The present invention provides a novel compound, which uses a multi-conjugated fused ring carbazole structure as a parent core, can improve the planarity of the molecule, reduce the carrier transmission barrier, and make the device have the advantages of low voltage and high efficiency. In addition, the molecule has a rigid structure of multi-conjugated fused rings, strong molecular chemical stability, excellent thermal stability, and the performance in the device also shows a good lifespan;

[0027] In addition, the N of carbazole is substituted with an electron-withdrawing group, a quinoxaline group (Formula II) or a quinazoline group (III). This fixed combination reduces the overlapping region of the HOMO and LUMO energy levels of the material of the present invention, resulting in a smaller energy difference between the singlet state and the triplet state, reducing the non-radiative transition of the main material, further reducing the voltage and improving the efficiency.

[0028] When Ar is selected from the structure of formula III, a bridging group L2 must be set between carbazole and quinazoline. Setting a bridging group between these two groups can distort the molecular spatial configuration. The distorted molecular configuration can avoid the luminescence quenching effect caused by the π-π interaction between molecules in the aggregated state, thereby achieving efficient luminescence of organic compounds.

[0029] Preferably, the Y 1 , Y 2 , Y 3 , Y 4 , Y 5 , Y 6 , Y 7 , Y 8 , Y 9 , Y 10 , Y 11 , Y 12 , Y 13 , Y 14 , Y 15 and Y 16 Each independently selected from CH, CR 1 or N; where R 1 Has the same range of options as before.

[0030] Preferably, the Y 1 , Y 2 , Y 3 and Y 4 Each independently selected from CH, CR 1 or one of N, Y 5 , Y 6 , Y 7 , Y 8 , Y 9, Y 10 , Y 11 , Y 12 , Y 13 , Y 14 , Y 15 and Y 16 Each independently selected from CH or CR 1 ; where R 1 Has the same range of options as before.

[0031] Preferably, the Y 1 , Y 2 , Y 3 , Y 4 , Y 5 , Y 6 , Y 7 , Y 8 , Y 9 , Y 10 , Y 11 , Y 12 , Y 13 , Y 14 , Y 15 and Y 16 Each is independently selected from CH.

[0032] The present invention preferably 1 ~Y 16 All of them are CH. This is because when all of them are CH, the HOMO energy level of this type of molecule just matches the energy level of the adjacent layer material, and has good transmission performance. When substituents are added to the power supply parent core, the HOMO energy level will change.

[0033] Preferably, the R 1 The invention is selected from a substituted or unsubstituted phenyl group, a substituted or unsubstituted pyridyl group, a substituted or unsubstituted biphenyl group, a substituted or unsubstituted carbazolyl group, a substituted or unsubstituted thienyl group, and a substituted or unsubstituted triarylamine group, preferably a substituted or unsubstituted pyridyl group, a substituted or unsubstituted carbazolyl group, a substituted or unsubstituted thienyl group, and a substituted or unsubstituted triarylamine group.

[0034] Preferably, Ar has a structure shown in Formula IV or Formula V;

[0035]

[0036] In formula IV and formula V, * represents the access bond of the group;

[0037] The R 3 , R 4 , L 1 and L 2 Each independently has the same scope as Formula II and Formula III.

[0038] Preferably, Ar has a structure shown in Formula IV.

[0039] Preferably, Ar has a structure shown in Formula V.

[0040] Preferably, the R 3 and R 4 Each is independently selected from a substituted or unsubstituted phenyl group, a substituted or unsubstituted naphthyl group, a substituted or unsubstituted biphenyl group, a substituted or unsubstituted dibenzofuranyl group, a substituted or unsubstituted dibenzothienyl group, a substituted or unsubstituted 9,9-dimethylfluorenyl group, a substituted or unsubstituted pyridyl group, and a substituted or unsubstituted phenanthryl group.

[0041] Preferably, the R 3 and R 4 Each is independently selected from one of phenyl, naphthyl, biphenyl, dibenzofuranyl, dibenzothiophenyl, 9,9-dimethylfluorenyl, pyridyl and phenanthryl.

[0042] Preferably, the L 1 It is one selected from the group consisting of a single bond, a phenylene group, a pyridylene group, a pyridine-substituted phenylene group, and a cyano-substituted phenylene group, preferably a single bond or a phenylene group.

[0043] Preferably, the L 2 It is one selected from the group consisting of phenylene, naphthylene, pyridine-substituted phenylene, and cyano-substituted phenylene, preferably phenylene.

[0044] Preferably, the compound has the structure shown in P1 to P80 below:

[0045]

[0046]

[0047]

[0048]

[0049]

[0050] The second object of the present invention is to provide an application of the compound described in the first object, wherein the compound is applied to an organic electroluminescent device.

[0051] Preferably, the compound is used as a light-emitting layer material of the organic electroluminescent device, preferably as a light-emitting layer host material.

[0052] The third object of the present invention is to provide an organic electroluminescent device, comprising a substrate, a first electrode, a second electrode and at least one organic layer located between the first electrode and the second electrode, wherein the organic layer contains at least one compound described in one of the objects.

[0053] Preferably, the organic layer comprises a light-emitting layer, and the light-emitting layer contains at least one compound described in one of the purposes.

[0054] Preferably, the compound is used as a host material of the light-emitting layer.

[0055] Specifically, an organic electroluminescent device (OLED) includes a first electrode, a second electrode, and an organic material layer between the electrodes. The organic material can be divided into multiple regions. For example, the organic material layer can include a hole transport region, a light emitting layer, and an electron transport region.

[0056] In a specific embodiment, a substrate may be used below the first electrode or above the second electrode. The substrate is a glass or polymer material with excellent mechanical strength, thermal stability, water resistance, and transparency. In addition, a thin film transistor (TFT) may also be provided on the substrate used as a display.

[0057] The first electrode can be formed by sputtering or depositing the material used as the first electrode on the substrate. When the first electrode is used as an anode, an oxide transparent conductive material such as indium tin oxide (ITO), indium zinc oxide (IZO), tin dioxide (SnO2), zinc oxide (ZnO) and any combination thereof can be used. When the first electrode is used as a cathode, a metal or alloy such as magnesium (Mg), silver (Ag), aluminum (Al), aluminum-lithium (Al-Li), calcium (Ca), magnesium-indium (Mg-In), magnesium-silver (Mg-Ag) and any combination thereof can be used.

[0058] The organic material layer can be formed on the electrode by vacuum thermal evaporation, spin coating, printing, etc. The compound used as the organic material layer can be organic small molecules, organic macromolecules and polymers, and combinations thereof.

[0059] The hole transport region is located between the anode and the light-emitting layer. The hole transport region can be a hole transport layer (HTL) of a single-layer structure, including a single-layer hole transport layer containing only one compound and a single-layer hole transport layer containing multiple compounds. The hole transport region can also be a multi-layer structure including at least one layer of a hole injection layer (HIL), a hole transport layer (HTL), and an electron blocking layer (EBL).

[0060] The material of the hole transport region can be selected from, but not limited to, phthalocyanine derivatives such as CuPc, conductive polymers or polymers containing conductive dopants such as polyphenylene ethylene, polyaniline / dodecylbenzenesulfonic acid (Pani / DBSA), poly(3,4-ethylenedioxythiophene) / poly(4-styrenesulfonate) (PEDOT / PSS), polyaniline / camphorsulfonic acid (Pani / CSA), polyaniline / poly(4-styrenesulfonate) (Pani / PSS), aromatic amine derivatives such as the compounds shown in HT-1 to HT-34 below; or any combination thereof.

[0061]

[0062]

[0063]

[0064] The hole injection layer is located between the anode and the hole transport layer. The hole injection layer can be a single compound material or a combination of multiple compounds. For example, the hole injection layer can use one or more compounds of HT-1 to HT-34 mentioned above, or one or more compounds of HI-1 to HI-3 below; or one or more compounds of HT-1 to HT-34 can be doped with one or more compounds of HI-1 to HI-3 below.

[0065]

[0066] The light-emitting layer includes a light-emitting dye (i.e., dopant) that can emit different wavelength spectra, and may also include a host material (Host). The light-emitting layer can be a monochrome light-emitting layer that emits a single color such as red, green, and blue. A plurality of monochrome light-emitting layers of different colors can be arranged in a plane according to a pixel pattern, or they can be stacked together to form a color light-emitting layer. When light-emitting layers of different colors are stacked together, they can be separated from each other or connected to each other. The light-emitting layer can also be a single color light-emitting layer that can simultaneously emit different colors such as red, green, and blue.

[0067] According to different technologies, the light-emitting layer material can be made of different materials such as fluorescent electroluminescent materials, phosphorescent electroluminescent materials, and thermally activated delayed fluorescent materials. In an OLED device, a single light-emitting technology can be used, or a combination of multiple different light-emitting technologies can be used. These different light-emitting materials classified by technology can emit light of the same color or different colors.

[0068] In one aspect of the present invention, the light-emitting layer adopts phosphorescent electroluminescence technology, and the main material of the light-emitting layer is selected from, but not limited to, one or more combinations of GPH-1 to GPH-80.

[0069]

[0070]

[0071]

[0072] In one aspect of the present invention, the light-emitting layer adopts phosphorescent electroluminescence technology. The phosphorescent dopant of the light-emitting layer can be selected from, but not limited to, one or more combinations of RPD-1 to RPD-28 listed below.

[0073]

[0074]

[0075] The OLED organic material layer may further include an electron transport region between the light emitting layer and the cathode. The electron transport region may be a single-layer electron transport layer (ETL), including a single-layer electron transport layer containing only one compound and a single-layer electron transport layer containing multiple compounds. The electron transport region may also be a multilayer structure including at least one layer of an electron injection layer (EIL), an electron transport layer (ETL), and a hole blocking layer (HBL).

[0076] In one aspect of the present invention, the electron transport layer material can be selected from, but not limited to, one or more combinations of ET-1 to ET-57 listed below.

[0077]

[0078]

[0079]

[0080]

[0081] The device may also include an electron injection layer located between the electron transport layer and the cathode. The electron injection layer material includes but is not limited to one or more combinations of the following: LiQ, LiF, NaCl, CsF, Li2O, Cs2CO3, BaO, Na, Li and / or Ca.

[0082] Compared with the prior art, the present invention has the following beneficial effects:

[0083] The present invention provides a novel compound, which uses a multi-conjugated fused ring carbazole structure as a parent core, can improve the planarity of the molecule, reduce the carrier transmission barrier, and make the device have the advantages of low voltage and high efficiency. In addition, the molecule has a rigid structure of multi-conjugated fused rings, strong molecular chemical stability, excellent thermal stability, and the performance in the device also shows a good lifespan;

[0084] In addition, the N of carbazole is substituted with an electron-withdrawing group, a quinoxaline group (Formula II) or a quinazoline group (III). This fixed combination reduces the overlapping region of the HOMO and LUMO energy levels of the material of the present invention, resulting in a smaller energy difference between the singlet state and the triplet state, reducing the non-radiative transition of the main material, further reducing the voltage and improving the efficiency. DETAILED DESCRIPTION

[0085] The technical solution of the present invention is further described below by specific implementation methods. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0086] The representative synthesis route of the compound of formula I of the present invention is as follows:

[0087]

[0088] Among them, Ar, Y 1 To Y 16 All have the same meanings as in Formula I.

[0089] More specifically, the following synthesis examples provide methods for preparing specific compounds:

[0090] Synthesis Example 1: Synthesis of Compound P1

[0091]

[0092] 10-Bromobenzo[g]chrysene (100 mmol), o-nitrobenzeneboric acid (120 mmol), potassium carbonate (45 mmol), dioxane (200 mL), tetrakis(triphenylphosphine)palladium 1.2 g, and water (50 mL) were added to a reaction flask and heated to reflux for 6 h. The reaction was monitored by thin layer chromatography (TLC) until completion, and the mixture was added to water, extracted with ethyl acetate, and the organic phase was concentrated to obtain intermediate A.

[0093] Intermediate A (60 mmol), triphenylphosphine (180 mmol) and 200 mL of o-dichlorobenzene were added to a reaction bottle, heated to reflux for 4 h, and the reaction was completed under the control of TLC. The product was directly concentrated to dryness and purified by column chromatography to obtain B.

[0094] Intermediate B (30 mmol), 2-(4-fluorophenyl)-4-phenylquinazoline (35 mmol), cesium carbonate (60 mmol) and N,N-dimethylformamide (DMF, 150 mL) were added to a reaction bottle and refluxed for 8 h. After the reaction was complete, the temperature was cooled to room temperature, the reaction solution was poured into water and filtered, the filter cake was washed once with ethanol and then recrystallized from toluene to obtain compound P1.

[0095] Synthesis Example 2: Synthesis of Compound P15

[0096] The synthesis method is different from that of Synthesis Example 1 in that 2-(4-fluorophenyl)-4-phenylquinazoline is replaced with an equal amount of 2-(2-fluoropyridin-5-yl)-4-phenylquinazoline to obtain compound P15.

[0097] Synthesis Example 3: Synthesis of Compound P22

[0098] The synthesis method is different from that of Synthesis Example 1 in that 2-(4-fluorophenyl)-4-phenylquinazoline is replaced with an equal amount of 2-(3-biphenyl)-3-chloroquinoxaline to obtain compound P22.

[0099] Synthesis Example 4: Synthesis of Compound P27

[0100] The synthesis method is different from that of Synthesis Example 1 in that 2-(4-fluorophenyl)-4-phenylquinazoline is replaced with an equal amount of 2-(4-fluorophenyl)-3-phenylquinazoline to obtain compound P27.

[0101] Synthesis Example 5: Synthesis of Compound P41

[0102]

[0103] Intermediate B (30 mmol), 3-bromo-5-cyanofluorobenzene (30 mmol), potassium carbonate (50 mmol), and 200 mL of N,N-dimethylformamide (DMF) were added into a reaction flask and refluxed for 3 h. The reaction solution was poured into water and filtered. The filter cake was washed with methanol and dried to obtain intermediate 41-A.

[0104] 41-A (20 mmol), bipyraclostrobin (30 mmol), potassium acetate (30 mmol), ([1,1'-bis(diphenylphosphino)ferrocene]palladium dichloride, 0.2 mmol), and 300 mL of dioxane were added into a reaction bottle and refluxed for 4 h under nitrogen protection. After the reaction was completed, water was added, and the organic phase was separated and concentrated after extraction with dichloromethane to obtain intermediate 41-B.

[0105] 41-B (15 mmol), 2-chloro-3-phenylquinoxaline (20 mmol), potassium carbonate (30 mmol), dioxane (150 mL), tetrakis(triphenylphosphine)palladium 0.5 g, and water (30 mL) were added to a reaction flask and heated to reflux for 6 h. The reaction was monitored by TLC to be complete. After cooling, the mixture was directly filtered. The filter cake was dissolved in dichloromethane and then filtered by column chromatography. After concentration, the mixture was recrystallized from xylene to obtain P41.

[0106] Synthesis Example 6: Synthesis of Compound P53

[0107] The synthesis method is different from that of Synthesis Example 1 in that o-nitrophenylboric acid is replaced with an equal amount of 4-nitro-3-pyridinepinacol ester to obtain compound P53.

[0108] Synthesis example 7:

[0109] Synthesis of compound P72

[0110]

[0111] Intermediate B (30 mmol) and DMF 200 mL were added to a reaction flask, cooled to 0°C, and N-bromosuccinimide (NBS, 35 mmol) was added dropwise. After the addition was complete, the mixture was reacted at room temperature for 2 h. After the reaction was completed under HPLC monitoring, the mixture was poured into water and filtered to obtain intermediate 72-A.

[0112] 72-A (20 mmol), triphenylamine-4-boric acid (20 mmol), potassium carbonate (30 mmol), dioxane (150 mL), tetrakis(triphenylphosphine)palladium 0.5 g, and water (30 mL) were added to a reaction flask and heated to reflux for 4 h. The reaction was completed after TLC monitoring. After cooling, water and dichloromethane were added for extraction, and the organic phase was concentrated to obtain 72-B.

[0113] 72-B (15 mmol), 2-chloro-3-phenylquinoxaline (20 mmol), cesium carbonate (30 mmol) and DMF (150 mL) were added to a reaction bottle and refluxed for 8 h. After the reaction was complete, the temperature was cooled to room temperature. The reaction solution was poured into water and filtered. The filter cake was washed once with ethanol and then recrystallized from toluene to obtain compound P72.

[0114] In order to verify the certainty of the above molecular structure, we confirmed it through elemental analysis (measuring instrument: Thermo Fisher FLASH2000CHNS / O organic element analyzer) and mass spectrometry information (measuring instrument: ZAB-HS mass spectrometer, manufactured by Micromass, UK), as shown in Table 1.

[0115] Table 1

[0116] Compound Elemental analysis (%) Mass spectrometry P1 C, 89.00; H, 4.51; N, 6.49 647.2 P15 C, 87.01; H, 4.35; N, 8.64 648.2 P22 C, 89.00; H, 4.51; N, 6.49 647.2 P27 C, 89.00; H, 4.51; N, 6.49 647.2 P41 C, 87.48; H, 4.19; N, 8.33 672.2 P53 C, 87.01; H, 4.35; N, 8.64 648.2 P72 C, 88.43; H, 4.70; N, 6.87 814.3

[0117] Example 1

[0118] This embodiment provides an organic electroluminescent device, and the specific preparation method is as follows:

[0119] The glass plate coated with the ITO transparent conductive layer was ultrasonically treated in a commercial cleaning agent, rinsed in deionized water, ultrasonically degreased in a mixed solvent of acetone:ethanol, baked in a clean environment to completely remove the moisture, cleaned with ultraviolet light and ozone, and bombarded with a low-energy cation beam;

[0120] Place the glass substrate with the anode in a vacuum chamber and evacuate to a vacuum of <1×10 -5 Pa, on the above anode layer film, 10nm of HT-4:HI-3 (97 / 3, w / w) mixture was vacuum-evaporated in sequence as a hole injection layer, 60nm of compound HT-4 as a hole transport layer, 40nm of compound P1:RPD-8 (100:3, w / w) binary mixture as a light-emitting layer, 25nm of compound ET-46:ET-57 (50 / 50, w / w) mixture as an electron transport layer, 1nm of LiF as an electron injection layer, and 150nm of metal aluminum as a cathode. The total evaporation rate of all organic layers and LiF was controlled at 0.1nm / sec, and the evaporation rate of the metal electrode was controlled at 1nm / sec.

[0121] The difference between Examples 2 to 10 and Comparative Examples 1 to 2 and Example 1 is only that the main material of the light-emitting layer is replaced, as shown in Table 2 for details.

[0122] The structures of the main materials of the light-emitting layers in Comparative Examples 1 and 2 are as follows:

[0123]

[0124] For details of compounds C1 and C2, see WO2017109722A1 and CN109956876A, respectively;

[0125] Performance Testing

[0126] (1) Under the same brightness, the driving voltage and current efficiency of the organic electroluminescent devices prepared in the examples and comparative examples were measured using a PR 750 photoradiometer, ST-86LA luminance meter (Beijing Normal University Photoelectric Instrument Factory) and Keithley 4200 test system. Specifically, the voltage was increased at a rate of 0.1 V per second, and the current efficiency of the organic electroluminescent device was measured when the current density reached 10 mA / cm 2 The voltage at this time is the driving voltage, and the brightness at this time is measured at the same time; the ratio of brightness to current density is the current efficiency;

[0127] The above performance test results are shown in Table 2.

[0128] Table 2

[0129]

[0130]

[0131] It can be seen from Table 2 that when the compound provided by the present invention is used as the main material of the light-emitting layer of an organic electroluminescent device, the device has both a lower driving voltage and a higher current efficiency, wherein the driving voltage is 3.5 to 3.8 V and the current efficiency is 14.3 to 15.8 cd / A.

[0132] Compared with compound C1 (Comparative Example 1), compound P1 (Example 1) is very similar in structure, but the difference is that the ring closing direction of carbazole is different, and they are two different material structures. The specific mother core structure of the present invention enables compound P1 to have better performance in voltage and efficiency. It is speculated that the mother core structure of the present invention increases the steric hindrance of the material, prevents the mutual quenching of excitons, and improves the material performance of the present invention.

[0133] In comparative example 2, two electron-withdrawing groups, a carbazole group and a triazine group, are introduced into the main material C2 of the light-emitting layer. Compared with all the embodiments, the device performance of comparative example 2 is poor, specifically, the voltage is increased and the current efficiency is reduced, which proves that the present invention can effectively improve the device performance by replacing a specific electron-withdrawing group on the N of carbazole. This is because this fixed combination reduces the overlapping area of ​​the HOMO and LUMO energy levels of the material of the present invention, resulting in a smaller energy difference between the singlet state and the triplet state, reducing the non-radiative transition of the main material, and reducing its voltage while having higher efficiency.

[0134] The present invention illustrates the detailed method of the present invention through the above-mentioned embodiments, but the present invention is not limited to the above-mentioned detailed method, that is, it does not mean that the present invention must rely on the above-mentioned detailed method to be implemented. Those skilled in the art should understand that any improvement of the present invention, equivalent replacement of various raw materials of the product of the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A compound, characterized in that The compound has a structure shown in Formula I; In Formula I, the Y 3 Selected from CH, CR 1 or one of N; The Y 11 Select from CH or CR 2 One of the following; Y 1 , Y 2 , Y 4 , Y 5 , Y 6 , Y 7 , Y 8 , Y 9 , Y 10 , Y 12 , Y 13 , Y 14 , Y 15 and Y 16 for CH; The R 1 One selected from phenyl and pyridyl; The R 2 is cyano; In Formula I, Ar has a structure shown in Formula IV or Formula V; In Formula IV and Formula V, * represents the access bond of the group; 3 and R 4 Each is independently selected from one of phenyl, naphthyl, biphenyl, dibenzofuranyl, dibenzothiophenyl, 9,9-dimethylfluorenyl, pyridyl and phenanthryl; the L 1 is selected from the group consisting of a single bond, a phenylene group, a pyridylene group, a pyridine-substituted phenylene group, and a cyano-substituted phenylene group, wherein L 2 One selected from the group consisting of phenylene, naphthylene, pyridine-substituted phenylene, and cyano-substituted phenylene.

2. The compound according to claim 1, characterized in that The Y 1 , Y 2 , Y 3 , Y 4 , Y 5 , Y 6 , Y 7 , Y 8 , Y 9 , Y 10 , Y 11 , Y 12 , Y 13 , Y 14 , Y 15 and Y 16 Each is independently selected from CH.

3. The compound according to claim 1, characterized in that The Ar has a structure shown in Formula IV.

4. The compound according to claim 1, characterized in that The Ar has a structure shown in Formula V.

5. It has the structure shown in P1 to P80 below:

6. Use of a compound according to any one of claims 1 to 5, characterized in that: The compound is applied to organic electroluminescent devices.

7. The use according to claim 6, characterized in that: The compound is used as a light-emitting layer material of the organic electroluminescent device.

8. The use according to claim 7, characterized in that: The compound is used as a host material of a light-emitting layer of an organic electroluminescent device.

9. An organic electroluminescent device, characterized in that: The organic electroluminescent device comprises a substrate, a first electrode, a second electrode and at least one organic layer located between the first electrode and the second electrode, wherein the organic layer comprises at least one compound according to any one of claims 1 to 5.

10. The organic electroluminescent device according to claim 9, characterized in that: The organic layer includes a light-emitting layer, and the light-emitting layer contains at least one compound according to any one of claims 1 to 5.

11. The organic electroluminescent device according to claim 10, characterized in that: The compound serves as a host material of the light-emitting layer.

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