Organic compounds, organic layers and their applications, organic electroluminescent devices

Abstract

This application discloses an organic compound, an organic layer and its uses, and an organic electroluminescent device, relating to the field of organic electroluminescent materials technology. The general formula of the organic compound is shown in Formula I or Formula II. The molecular structure of the organic compound has cross-hyperconjugated properties, which gives the molecular structure good thermal stability and charge transport capability. Therefore, when it is applied to organic electroluminescent devices, it can not only improve the efficiency and service life of the device, but also reduce the operating voltage of the device.

Description

Technical Field

[0001] This application relates to the field of organic electroluminescent materials technology, specifically to an organic compound, an organic layer and its uses, and an organic electroluminescent device. Background Technology

[0002] Organic light-emitting devices (such as organic light-emitting diodes, or OLEDs for short) are a new type of display technology with unique advantages such as self-illumination, wide viewing angle, low energy consumption, high efficiency, thinness, rich colors, fast response speed, wide applicable temperature range, low driving voltage, the ability to make flexible, bendable and transparent display panels, and environmental friendliness. They can be used in flat panel displays and next-generation lighting, and can also be used as backlights for LCDs.

[0003] With the rapid development of display and lighting technologies, higher demands are being placed on the performance of organic electroluminescent devices. Therefore, it is necessary to continuously develop high-performance organic electroluminescent materials to improve the performance of organic electroluminescent devices and meet market needs. Summary of the Invention

[0004] The technical problem addressed by this application is to improve the performance of organic electroluminescent devices.

[0005] To solve the above-mentioned technical problems, this application provides the following technical solution:

[0006] A first aspect of this application provides an organic compound, the structural formula of which is shown in Formula I or Formula II: In Formulas I and II: X and Y are selected from the group consisting of O, S, Se, and NR each time they appear, either identically or differently, wherein R is selected from the group consisting of: acyl, carbonyl, carboxylic acid, ester, cyano, isocyano, thiocyano, isocyanate, pentafluorosulfonyl, sulfinyl, sulfonyl, phosphoxy, partially fluorinated or perfluorinated C1-C12 alkyl, partially fluorinated or perfluorinated C3-C12 cycloalkyl, substituted or unsubstituted C6-C24 aryl, substituted or unsubstituted C3-C24 heteroaryl; R1-R 12 When present, they are selected from the group consisting of, either identically or differently from, hydrogen, deuterium, halogen, nitrosyl, nitro, acyl, carbonyl, carboxylic acid, ester, cyano, isocyanate, thiocyanate, isocyanate, pentafluorosulfonyl, sulfinyl, sulfonyl, phosphooxy, substituted or unsubstituted C6-C24 aryl, substituted or unsubstituted C3-C24 heteroaryl; A1, A2, and A3 are selected from, either identically or differently from, formula III or formula IV: When Ar1 is present, it is selected from substituted or unsubstituted C6-C24 aryl groups and substituted or unsubstituted C3-C24 heteroaryl groups; when R', R”, and R”’ are present, they are selected from electron-withdrawing groups in the same or different ways.

[0007] A second aspect of this application provides an organic layer comprising any of the organic compounds described above.

[0008] A third aspect of this application provides the use of any of the above-described organic compounds or organic layers in organic electroluminescent devices.

[0009] A fourth aspect of this application provides an organic electroluminescent device, including a first electrode, a second electrode, and the aforementioned organic layer located between the first electrode and the second electrode.

[0010] The organic compounds of this application possess cross-hyperconjugated molecular structures, resulting in excellent thermal stability and charge transport capabilities. Specifically, by employing electron-withdrawing substituents to complement the cross-hyperconjugated π bonds, the thermal stability and charge transport capabilities of the molecules are significantly enhanced. Therefore, when using the organic compounds of this application to fabricate organic electroluminescent devices, not only can the device efficiency and lifespan be improved, but the operating voltage can also be reduced. Attached Figure Description

[0011] The following accompanying drawings describe in detail the exemplary embodiments disclosed in this application. The same reference numerals denote similar structures in several views of the drawings. Those skilled in the art will understand that these embodiments are non-limiting and exemplary, and the drawings are for illustrative purposes only and are not intended to limit the scope of this application. Other embodiments may similarly fulfill the inventive intent of this application. It should be understood that the drawings are not drawn to scale. Wherein:

[0012] Figure 1 This is a schematic diagram of the structure of the organic electroluminescent device prepared in Example 10 of this application;

[0013] Figure 2 This is a schematic diagram of the structure of the organic electroluminescent device prepared in Example 19 of this application. Detailed Implementation

[0014] The following description provides specific application scenarios and requirements for this application, intended to enable those skilled in the art to make and use the content of this application. Various partial modifications to the disclosed embodiments will be apparent to those skilled in the art, and the general principles defined herein can be applied to other embodiments and applications without departing from the spirit and scope of this application. Therefore, this application is not limited to the embodiments shown, but rather to the widest scope consistent with the claims.

[0015] The following is a detailed explanation of some terms used in this application:

[0016] Substituted or unsubstituted: refers to substitution with one or more substituents, or no substitution at all. Substituents can be selected from, for example, the following: deuterium, halogen, fluorine, trifluoromethyl, cyano, nitro, hydroxyl, carbonyl, ester, imide, amino, phosphoxy, alkoxy, aryloxy, sulfone, sulfoxide, alkylthio, arylthio, alkylsulfonyl, arylsulfonyl, silyl, boron, alkyl, cycloalkyl, alkenyl, aryl, heteroaryl, aralkyl, arylenyl, alkylaryl, alkylamine, aralkylamine, heteroarylamine, arylamine, arylphosphinyl, heterocyclic, carboxyl derivative groups, etc.; or substitution with substituents that connect to two or more of the substituents listed above. For example, "substituents that connect to two or more substituents" can include biphenyl, i.e., biphenyl can be aryl, or a substituent that connects to two phenyl groups. When substituted with two or more substituents, adjacent substituents can also bond to form a ring. As an example, cyclization can be achieved through chemical bonding or through fusion.

[0017] Aryl group: Not particularly limited, it can be monocyclic or polycyclic aryl. In some embodiments, monocyclic aryl includes, but is not limited to, phenyl, biphenyl, terphenyl, tetraphenyl, pentaphenyl, etc. Polycyclic aryl includes, but is not limited to, naphthyl, anthracene, phenanthryl, pyrene, perylene, fluorene, etc. The fluorene group can be substituted, such as 9,9'-dimethylfluorenel, 9,9'-dibenzofluorenel, etc. In addition, two of the substituents can combine with each other to form a spirocyclic structure, such as 9,9'-spirodifluorenel, etc.

[0018] The above description of aryl groups can be applied to aryl groups in the following categories: aryloxy, arylsilyl, arylgermanium, arylthio, arylsulfonyl, arylphosphinyl, arylalkyl, arylalkylamine, arylenyl, alkylaryl, arylamine, and arylheteroarylamine.

[0019] Heteroaryl groups: Containing one or more of B, N, O, P, S, Si, and Se as heteroatoms. Heteroaryl groups include, but are not limited to, pyridinyl, pyrrolyl, pyrimidinyl, pyridazinyl, furanyl, thiopheneyl, imidazolyl, pyrazolyl, azole, isozolyl, thiazolyl, isothiazolyl, triazolyl, diazolyl, thiadiazolyl, dithiazolyl, tetrazolyl, pyranyl, thiaranyl, pyrazinyl, azinyl, thiazolyl, dioxazinyl, dioxazinyl, triazinyl, tetraazinyl, quinolinyl, isoquinolinyl, quinolinyl, quinazolinyl, quinoxalinyl, naphridinyl, acridineyl, xanthyl, phenanthridineyl, diazanaphthyl, triazaindenyl, indoleyl, dihydroindoleyl, nitro-indenyl, phthalazinyl, pyridopyrimidinyl, pyridopyrazinyl, pyrazinyl Pyrazinyl, benzothiazolyl, benzoxazolyl, benzoimidazolyl, benzothiophene, benzofuranyl, dibenzothiophene, dibenzofuranyl, carbazoleyl, benzocarbazoleyl, dibenzocarbazoleyl, indolocarbazoleyl, indocarbazoleyl, phenazinyl, imidazopyridyl, phenazinyl, phenanthrinyl, phenthiazolyl, imidazopyridyl, imidazophenanthrinyl, benzoimidazoquinazolinyl, benzoimidazophenanthrinyl, spiro[fluorene-9,9'-oxazanthracene], phenylbinaphthyl, dinaphthofuranyl, naphthobenzofuranyl, dinaphthiophene, naphthobenzothiophene, triphenylphosphine oxide, triphenylborane, etc.

[0020] The above description of heteroaryl groups can be applied to heteroaryl groups in heteroaryl amines and aryl heteroaryl amines.

[0021] Alkyl groups: may be straight-chain or branched, including but not limited to methyl, ethyl, propyl, n-propyl, isopropyl, butyl, n-butyl, isobutyl, tert-butyl, sec-butyl, 1-methyl-butyl, 1-ethyl-butyl, pentyl, n-pentyl, isopentyl, neopentyl, tert-pentyl, hexyl, n-hexyl, 1-methylpentyl, 2-methylpentyl, 4-methyl-2-pentyl, 3,3-dimethylbutyl, 2-ethylbutyl, heptyl, n-heptyl, 1-methylhexyl, cyclopentylmethyl, cyclohexylmethyl, octyl, n-octyl, tert-octyl, 1-methylheptyl, 2-ethylhexyl, 2-propylpentyl, n-nonyl, 2,2-dimethylheptyl, 1-ethyl-propyl, 1,1-dimethyl-propyl, isohexyl, 4-methylhexyl, 5-methylhexyl.

[0022] The above description of alkyl groups can also be used for alkyl groups in aralkyl, alkylgermanium, aralkylamine, alkylaryl, and alkylamine groups.

[0023] Cycloalkyl groups: also known as cyclic saturated hydrocarbon groups, such as cyclopropyl, cyclobutyl, cyclopentyl, 3-methylcyclopentyl, 2,3-dimethylcyclopentyl, cyclohexyl, 3-methylcyclohexyl, 4-methylcyclohexyl, 2,3-dimethylcyclohexyl, 3,4,5-trimethylcyclohexyl, 4-tert-butylcyclohexyl, cycloheptyl, cyclooctyl, etc.

[0024] Electron-withdrawing groups are groups that can attract electrons, thereby reducing the electron cloud density of the atoms or groups attached to them. Examples include fluorine, cyano, and trifluoromethyl.

[0025] A first aspect of this application provides an organic compound, the structural formula of which is shown in Formula I or Formula II:

[0026]

[0027] In Formulas I and II, X and Y, each time appearing, are selected from the group consisting of O, S, Se, and NR, either identically or differently, wherein R is selected from the group consisting of: acyl, carbonyl, carboxylic acid, ester, cyano, isocyano, thiocyanate, isocyanate, pentafluorosulfonyl, sulfinyl, sulfonyl, phosphoxy, partially fluorinated or perfluorinated C1-C12 alkyl, partially fluorinated or perfluorinated C3-C12 cycloalkyl, substituted or unsubstituted C6-C24 aryl, substituted or unsubstituted C3-C24 heteroaryl. In the case of R, "substituted or unsubstituted," the substituent is preferably selected from one or more of deuterium, nitro, cyano, halogen, partially fluorinated or perfluorinated C1-C12 alkyl, and partially fluorinated or perfluorinated C1-C6 alkoxy, wherein the substituents may be the same as or different from each other.

[0028] R1~R 12 When present, they are selected from the group consisting of, either identically or differently from, hydrogen, deuterium, halogen, nitrosyl, nitro, acyl, carbonyl, carboxylic acid, ester, cyano, isocyanate, thiocyanate, isocyanate, pentafluorosulfonyl, sulfinyl, sulfonyl, phosphoxy, substituted or unsubstituted C6-C24 aryl, substituted or unsubstituted C3-C24 heteroaryl. The R1-R... 12 In the phrase "substituted or unsubstituted", the substituent is preferably selected from one or more of the following: deuterium, halogen, nitroso, nitro, acyl, carbonyl, carboxylic acid, ester, cyano, isocyano, thiocyano, isocyanate, pentafluorosulfonyl, sulfinyl, sulfonyl, phosphoxy, partially fluorinated or perfluorinated C1-C12 alkyl, and partially fluorinated or perfluorinated C1-C6 alkoxy, wherein the substituents may be the same as or different from each other.

[0029] A1, A2, and A3 may be selected from Equation III or Equation IV, either identically or differently: When Ar1 is present, it is selected from substituted or unsubstituted C6-C24 aryl groups and substituted or unsubstituted C3-C24 heteroaryl groups; when R', R”, and R”’ are present, they are selected from electron-withdrawing groups, either the same or different. In Ar1, the substituents in “substituted or unsubstituted” are preferably one or more of deuterium, nitro, cyano, halogen, partially fluorinated or perfluorinated C1-C12 alkyl groups, and partially fluorinated or perfluorinated C1-C6 alkoxy groups, wherein the substituents are the same or different from each other. The electron-withdrawing groups are preferably from the group consisting of: halogen, nitroso, nitro, acyl, carbonyl, carboxylic acid, ester, cyano, isocyano, thiocyanate, isocyanate, pentafluorosulfonyl, sulfinyl, sulfonyl, phosphoxy, and haloalkyl.

[0030] In some embodiments, the organic compound has the structural formula shown in Formula I; preferably, Formula I satisfies any one or more of the following characteristics:

[0031] 1) X is selected from O, S, and Se;

[0032] 2) R1 to R 12 The radicals are selected from hydrogen, fluorine, cyano, isocyano, thiocyano, substituted or unsubstituted phenyl groups, either identically or differently; further, R1 to R... 12 In this context, the substituents are preferably selected from one or more of fluorine, cyano, isocyano, and thiocyano, wherein the substituents may be the same or different from each other; more preferably, R1 to R... 12 At least two of the molecules are electron-withdrawing groups, which, together with the cross-conjugated π bonds, greatly enhance the molecule's thermal stability and charge transport capacity.

[0033] 3) A1, A2 and A3 are selected from Formula IV in the same or different ways; more preferably, in Formula IV, R” and R”’ are selected from cyano, isocyano and thiocyano in the same or different ways.

[0034] In some preferred embodiments, the organic compound is represented by any of the following structural formulas:

[0035]

[0036] Among them, R5~R 12 When present, they are selected from hydrogen and fluorine, either identically or differently.

[0037] In some more preferred embodiments, the organic compound is selected from the group consisting of:

[0038]

[0039] In some embodiments, the organic compound has the structural formula shown in Formula II; preferably, Formula II satisfies any one or more of the following characteristics:

[0040] A) X and Y are selected from O, S, and Se each time they appear, whether the same or different.

[0041] B) R1 to R8 are selected from hydrogen, fluorine, cyano, isocyano, thiocyano, substituted or unsubstituted phenyl groups, either identically or differently; further, in R1 to R8, the substituents are preferably one or more of fluorine, cyano, isocyano, and thiocyano, wherein the substituents are identical or different from each other; preferably, at least two of R1 to R8 are groups with electron-withdrawing groups, which, in conjunction with cross-conjugated π bonds, greatly enhance the thermal stability and charge transport capacity of the molecule;

[0042] C) A1, A2 and A3 are selected from Formula IV in the same or different ways; preferably, in Formula IV, R” and R”' are selected from cyano, isocyano and thiocyano in the same or different ways.

[0043] In some preferred embodiments, the organic compound is represented by any of the following structural formulas:

[0044]

[0045] Among them, R5 to R8 are selected from fluorine and cyano groups, either the same or different.

[0046] In some more preferred embodiments, the organic compound is selected from the group consisting of:

[0047]

[0048] A second aspect of this application provides an organic layer comprising the organic compound described in the first aspect of this application.

[0049] The third aspect of this application provides the use of the organic compounds described in the first aspect or the organic layers described in the second aspect of this application in organic electroluminescent devices.

[0050] A fourth aspect of this application provides an organic electroluminescent device, comprising a first electrode, a second electrode, and an organic layer located between the first electrode and the second electrode. As an example, the first electrode is an anode, and the second electrode is a cathode; the cathode may be one or more layers. The organic layer may be a single-layer structure or a multilayer tandem structure with two or more organic layers laminated together. The organic layer may include at least one organic functional layer selected from the following: a hole injection layer, a hole transport layer, an electron blocking layer, a light-emitting layer, a hole blocking layer, an electron transport layer, and an electron injection layer; each organic functional layer may be a single layer or multiple layers.

[0051] When an organic light-emitting device (OLED) uses a single light-emitting layer, holes and electrons are injected from the anode and cathode, respectively, eliminating the need for a charge generation layer. When an OLED uses two or more light-emitting layers, a charge generation layer is required between the light-emitting layers to achieve the effects of charge generation, injection, and transport. The light emission direction of the OLED can be either from the anode side or the cathode side. When emitting from the cathode side, a capping layer needs to be added to the cathode side.

[0052] In some preferred embodiments, the organic layer includes a hole injection layer and / or a charge generation layer, and the hole injection layer and / or charge generation layer contains the organic compound described in the first aspect of this application.

[0053] The following describes some specific functional layers in the organic electroluminescent device.

[0054] Substrate:

[0055] The substrate is generally located below the anode. The substrate can be made of plastic or glass, and can be rigid or flexible. The substrate has a driving unit that can drive the corresponding pixel to emit light.

[0056] anode:

[0057] Organic EL (Organic Electro-Luminescence) devices typically require the anode to have good conductivity, a smooth surface, and be resistant to cracking. They also have certain requirements for work function, mainly to match the hole injection layer and achieve the hole injection effect.

[0058] When using a top-emitting method (cathode-side light emission), the anode is a metal compound with a work function of 4.2 eV or higher, such as indium tin oxide, tin oxide, indium zinc oxide, gold, silver, platinum, copper, carbon nanotubes, carbon nanowires, graphene, etc. The thickness is 10 nm to 200 nm, preferably 10 nm to 50 nm. A reflective electrode is placed below the anode (near the substrate end). The reflective electrode is generally made of metal or metal alloy, such as silver, copper, aluminum, gold, or alloys of these metals with other metals. The reflective electrode has high reflectivity, requiring a reflectivity of over 90%, and its thickness is typically between 100 nm and 500 nm, preferably in the range of 80 nm to 150 nm.

[0059] When bottom-emitting (substrate-side light emission) is used, the anode is a metal compound with a work function of 4.2 eV or higher, such as indium tin oxide, tin oxide, indium zinc oxide, gold, silver, platinum, copper, carbon nanotubes, carbon nanowires, graphene, etc. The thickness is 10 nm to 1 μm, preferably 50 nm to 200 nm.

[0060] The anode can be made by forming a thin film from the electrode material using methods such as vapor deposition, sputtering, or coating.

[0061] Hole injection layer:

[0062] The thickness of the hole injection layer is typically 3 nm to 20 nm. The hole injection layer uses a mixture of P-type and hole transport materials. The purpose of using P-type materials is to accept holes from the anode and transfer them to the hole transport material. The weight percentage of P-type materials in the hole injection layer is typically 0.5% to 10%. When the weight percentage is 0.5% to 3%, the absolute value of the difference between the lowest unoccupied molecular orbital (LUMO) energy level of the P-type material and the highest occupied molecular orbital (HOMO) energy level of the HTL material must not exceed 0.3 eV. When the weight percentage is 3% to 5%, the absolute value of the difference between the lowest unoccupied molecular orbital (LUMO) energy level of the P-type material and the highest occupied molecular orbital (HOMO) energy level of the HTL material must not exceed 0.5 eV. When the weight percentage is 5% to 10%, the absolute value of the difference between the lowest unoccupied molecular orbital (LUMO) energy level of the P-type material and the highest occupied molecular orbital (HOMO) energy level of the HTL material must not exceed 1 eV.

[0063] P-type materials can be metal oxides, such as molybdenum oxide, vanadium oxide, tungsten oxide, etc.; or organic compounds, such as 4,4',4”-((1E,1'E,1”E)-cyclopropane-1,2,3-trimethylenetris(cyanoformyl))tris(2,3,5,6-tetrafluorobenzyl) (PD1, CAS No.: 1224447-88-4), tetracyanoquinone dimethyl (TCNQ), 2,3,5,6-tetrafluoro-tetracyano-1,4-benzoquinone dimethyl (F4-TCNQ), 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazatriphenylene (HAT-CN), and are not limited thereto. Compared with the above-mentioned existing materials, when the P-type material adopts the organic compound of the first aspect of this application, the performance of the organic electroluminescent device can be effectively improved.

[0064] The hole transport material used in conjunction with the P-type material can be selected from the material of the second hole transport layer, and can be the same as or different from the material of the second hole transport layer.

[0065] First hole transport layer:

[0066] The thickness of the first hole transport layer is typically 3 nm to 500 nm. When there is no second hole transport layer, the thickness of the first hole transport layer is typically 40 nm to 500 nm; when there is a second hole transport layer, the thickness of the first hole transport layer is typically 3 nm to 40 nm.

[0067] Second hole transport layer:

[0068] The thickness of the second hole transport layer is generally 5nm to 150nm, and it often uses compounds containing aryl amines, such as monoaryl amines or polyaryl amines.

[0069] Electron blocking layer:

[0070] The electron blocking layer can simultaneously possess both hole transport and electron blocking functions. Furthermore, the higher triplet excitation energy level of the electron blocking layer can confine excitons generated in the emissive layer within it, thereby improving the device's luminous efficiency.

[0071] Emissive layer:

[0072] The materials of the light-emitting layer generally include a host material and a dopant material, with the content of the host material being greater than that of the dopant material.

[0073] Cavity blocking layer:

[0074] To enhance the balance between hole and electron concentrations, a hole blocking layer is inserted to balance carrier concentration and prevent exciton quenching. Typically, the hole blocking layer is located between the emitting layer and the electron transport layer, and the hole blocking layer material must meet conditions such as high stability, good film-forming properties, and a sufficiently high highest molecular occupied orbital.

[0075] First electron transport layer:

[0076] The thickness of the first electron transport layer can typically be 3nm–40nm, 3nm–10nm, 10nm–20nm, 20nm–30nm, 30nm–40nm, or 20nm–40nm. When there is no second electron transport layer, the thickness of the first electron transport layer is typically 20nm–40nm; when there is a second electron transport layer, the thickness of the first electron transport layer is typically 20nm–30nm. The first electron transport layer is in direct contact with the emitting layer, and therefore, similar to the first hole transport layer, it also undergoes electronic changes during electron transport, leading to increased molecular vibration and deformation. Furthermore, the interaction between the excitons of the emitting layer and the polarons of the electron transport material can easily generate reactive free radicals, which can damage the electron transport material. Electron transport materials can be single compounds or mixtures with other metal compounds, such as Liq.

[0077] Second electron transport layer:

[0078] The thickness of the second electron transport layer is generally 10 nm to 40 nm. The material of the second electron transport layer may include a mixture of organic electron transport materials and metal compounds, or a mixture of organic electron transport materials and metals.

[0079] When organic electron transport materials are mixed with metal compound materials, such as alkali metal compounds, alkaline earth metal compounds, and rare earth metal compounds, more specifically, they can be mixed with lithium metal compounds, calcium metal compounds, Mg metal compounds, samarium metal compounds, ytterbium metal compounds, etc., and even more specifically, they can be mixed with lithium 8-hydroxyquinoline, lithium fluoride, magnesium fluoride, ytterbium fluoride, calcium fluoride, etc. When used in combination with metal compounds, the mass percentage of the organic electron transport material can be 20%–80%, 20%–40%, 40%–60%, or 60%–80%, etc.

[0080] When organic electron transport materials are used in combination with metals, such as alkali metals, alkaline earth metals, and rare earth metals, or more specifically, with lithium metal, magnesium metal, calcium metal, ytterbium metal, and samarium metal, the mass ratio of the organic electron transport material can be 80%–99%, 80%–89%, 89%–99%, 80%–85%, 85%–90%, 90%–95%, or 95%–99%, etc.

[0081] Electron injection layer:

[0082] The electron injection layer can lower the potential barrier for electrons to be injected from the cathode into the organic layer, improve electron injection efficiency, and thus optimize device performance. The selection of materials for the electron injection layer needs to consider its work function matching with the cathode material, and can be selected from alkali metals, alkaline earth metals, rare earth metals, or their inorganic or coordination compounds.

[0083] Charge generation layer:

[0084] When using two or more light-emitting layers, a charge-generating layer is disposed between the two light-emitting layers. This layer is typically composed of two P / N type materials, where the P-type material can be selected from the hole injection materials mentioned earlier. In particular, when the P-type material of the charge-generating layer is an organic compound as described in the first aspect of this application, the performance of the organic electroluminescent device can be effectively improved.

[0085] The N-type material of the charge generation layer is a mixture of organic electron transport material and metal. The organic electron transport layer material is selected from the second electron transport layer mentioned earlier, and the metal is selected from alkali metals, alkaline earth metals, rare earth metals, and more specifically, lithium, magnesium, calcium, ytterbium, and samarium. When the organic electron transport material is mixed with the metal, the mass ratio of the organic electron transport material can be 80%–99%, 80%–89%, 89%–99%, 80%–85%, 85%–90%, 90%–95%, or 95%–99%, etc.

[0086] cathode:

[0087] The cathode requires materials with good electrical conductivity and a smooth surface. To improve electron injection capability, materials with a low work function are typically chosen. Cathode materials can be single-layer, double-layer, or multi-layer cathodes, generally made of metals or metal alloys. For single-layer cathodes, silver, copper, aluminum, gold, or alloys of these metals with other metals, such as rare earth metals, alkali metals, and alkaline earth metals, can be used. Examples include magnesium-indium alloys, magnesium-aluminum alloys, aluminum-potassium alloys, aluminum-scandium-potassium alloys, magnesium-silver alloys, silver-ytterbium alloys, and silver-samarium alloys. If a double-layer metal cathode is used, the cathode layer closer to the light-emitting layer can be made of alkali metals, alkaline earth metals, or rare earth metals, such as lithium, calcium, magnesium, and ytterbium, to increase electron injection capability. The cathode layer farther from the light-emitting side is mainly used to improve conductivity, and generally uses silver, copper, aluminum, gold, or alloys of these metals with other metals, such as alloys with rare earth metals, alkali metals, or alkaline earth metals. Examples include magnesium-indium alloys, magnesium-aluminum alloys, aluminum-potassium alloys, aluminum-scandium-potassium alloys, magnesium-silver alloys, silver-ytterbium alloys, and silver-samarium alloys. The cathode can also be formed into a thin film using methods such as vapor deposition or sputtering.

[0088] When light comes out from the anode side, the cathode must be opaque, and a cathode with a thickness greater than 100 nm can be deposited. When light comes out from the cathode side, the cathode must be transparent, with a transmittance greater than 40% and a thickness of 10 nm to 20 nm.

[0089] Overlay:

[0090] When light exits from the cathode side, photons resonate with electrons in the cathode metal, reducing the light extraction efficiency. Adding a capping layer on the side of the cathode furthest from the light-emitting layer can reduce this effect and effectively improve the light efficiency. When adding a capping layer, a capping layer material with high refractive index and low absorption coefficient should be used directly. For example, a material with a refractive index greater than 1.9 and an absorption rate less than 0.01% at a wavelength of 460 nm is preferred, a material with a refractive index greater than 2.0 and an absorption rate less than 0.01% at a wavelength of 460 nm is preferred, and a material with a refractive index greater than 2.1 and an absorption rate less than 0.01% at a wavelength of 460 nm is even more preferred.

[0091] The technical solution of this application will be clearly and completely described below with reference to the embodiments of this application. Unless otherwise specified, the reagents and raw materials used can be purchased commercially. Experimental methods in the following embodiments that do not specify specific conditions are generally determined according to national standards. If there is no corresponding national standard, then general international standards, conventional methods and conditions, or conditions recommended by the manufacturer, or the product instructions shall be followed. Unless otherwise stated, all parts are parts by weight, and all percentages are weight percentages.

[0092] The initial raw materials and solvents used in the following examples were purchased from Sinopharm, some commonly used OLED intermediates were purchased from domestic OLED intermediate manufacturers, and various palladium catalysts and ligands were purchased from Sigma-Aldrich. HPLC data were determined using a Shimadzu LC20AD high-performance liquid chromatograph; LC-MS (liquid chromatography-mass spectrometry) was performed on a Waters Corporation H-class+SQD2 instrument.

[0093] Compound Examples

[0094] Example 1

[0095] Synthesis of Compound 1

[0096]

[0097]

[0098] 1) Synthesis of intermediate 1-1

[0099] Under a nitrogen atmosphere, 28.0 g (200 mmol) of compound 1-A, 18.8 g (200 mmol) of compound 1-B, 3.4 g (60 mmol) of granular potassium hydroxide, and 500 mL of anhydrous ethanol were added sequentially to a reaction vessel, and the mixture was heated to reflux for 24 hours. The reaction mixture was concentrated to remove the solvent, and then subjected to column chromatography (eluent V). EA / V PE =1 / 10 to 1 / 3), concentrated to obtain 29.3 g of intermediate 1-1, HPLC purity 98.4%, yield 74%. LC-MS: M / Z 198.2 (M+).

[0100] 2) Synthesis of intermediates 1-2

[0101] At room temperature, 27.7 g (140 mmol) of intermediate 1-1 and 600 mL of anhydrous DMF were added to a reaction vessel, followed by the addition of 52.3 g (294 mmol) of NBS in portions. The mixture was stirred at room temperature for 12 hours. The reaction solution was then poured into 1800 mL of ice water, resulting in the precipitation of a solid. The mixture was stirred for 1 hour, filtered, washed with water and methanol, and the solid was dried under vacuum to obtain 45.3 g of intermediate 1-2 with an HPLC purity of 98.1% and a yield of 91%. LC-MS: M / Z 356.0 (M+).

[0102] 3) Synthesis of intermediates 1-3

[0103] To a reaction vessel, add 42.7 g (120 mmol) of intermediate 1-2, 63.6 g (252 mmol) of organic compound 1-C, 49.8 g (360 mmol) of potassium carbonate, 2.5 g (3.6 mmol) of Pd(PPh3)2Cl2, 800 mL of tetrahydrofuran, and 400 mL of water. The reaction system was purged with nitrogen three times, heated to 80 °C under reflux for 24 hours, cooled, extracted with ethyl acetate, concentrated, and subjected to rapid silica gel column chromatography (eluting with toluene). The solvent was concentrated to remove most of the solvent, and the residue was refluxed to dissolve the solids. Crystallization was achieved by adding n-hexane, followed by filtration after cooling, yielding 38.1 g of intermediate 1-3 with an HPLC purity of 98.8% and a yield of 83%. LC-MS: M / Z 382.4 (M+).

[0104] 4) Synthesis of intermediates 1-4

[0105] Intermediate 1-3 34.4 g (90 mmol) and 800 mL of dichloromethane, 800 mL of 0.3 M potassium hydroxide aqueous solution, and 59.3 g (180 mmol) of K3[Fe(CN)6] were added sequentially to the reaction vessel. The reaction was carried out at room temperature for 5 hours. The reaction was monitored by TLC until complete. The mixture was extracted and separated. The organic phase was washed with saturated brine, dried over anhydrous sodium sulfate, filtered, concentrated, and subjected to rapid column chromatography (eluent V). DCM / V PE =1 / 1), concentrated, the product was recrystallized with ethyl acetate and n-hexane, filtered, and the filter cake was dried under vacuum to give 21.6 g of intermediate 1-4, HPLC purity 97.5%, yield 63%. LC-MS: M / Z 380.4 (M+).

[0106] 5) Synthesis of Compound 1

[0107] Add 20.9 g (55 mmol) of intermediate 1-4, 36.4 g (550 mmol) of malononitrile, and 1000 mL of chlorobenzene to the reaction vessel. Heat to 100 °C. Add 104.3 g (550 mmol) of titanium tetrachloride and 52.2 g (660 mmol) of pyridine in three portions, 2 hours apart. After the additions are complete, continue the reaction for 48 hours. Cool down, pour the reaction mixture into an ice-cold saturated ammonium chloride aqueous solution, extract and separate the liquid, concentrate the organic phase, and perform silica gel column chromatography (eluent V). EA / V PE =1 / 10 to 1 / 1), concentrated, the solid product was vacuum dried, and the product was purified by sublimation to give 9.5 g of compound 1, with an HPLC purity of 99.7% and a yield of 33%. LC-MS: M / Z 524.5 (M+).

[0108] Examples 2-6

[0109] Compounds 2–6 shown in Table 1 were prepared according to the preparation method in Example 1.

[0110] Table 1. Raw materials and product compounds Example 7

[0111] Synthesis of Compound 7

[0112]

[0113]

[0114] 1) Synthesis of intermediate 7-1

[0115] Under a nitrogen atmosphere, 21.0 g (150 mmol) of compound 1-A, 58.5 g (150 mmol) of compound 7-B, 2.6 g (45 mmol) of granular potassium hydroxide, and 500 mL of anhydrous ethanol were added sequentially to a reaction vessel, and the mixture was heated to reflux for 24 hours. The reaction mixture was concentrated to remove the solvent, and then subjected to column chromatography (eluent V). EA / V PE =1 / 10 to 1 / 4), concentrated to obtain 57.8 g of intermediate 7-1, HPLC purity 98.6%, yield 78%. LC-MS: M / Z 494.3 (M+).

[0116] 2) Synthesis of intermediate 7-2

[0117] At room temperature, 54.4 g (110 mmol) of 7-1 and 800 mL of anhydrous DCM were added to the reaction vessel. The mixture was cooled in an ice-water bath, and 99.3 g (231 mmol) of [bis(trifluoroacetoxy)iodo]benzene and 53.3 g (231 mmol) of iodine were added in portions. After the addition was complete, the mixture was allowed to return to room temperature and stirred for 12 hours. The reaction solution was then poured into 1600 mL of saturated sodium sulfite ice-water solution. The organic phase was separated, dried over anhydrous sodium sulfate, concentrated, recrystallized with toluene and ethanol, filtered, and dried under vacuum to obtain 62.3 g of intermediate 7-2 with an HPLC purity of 98.7% and a yield of 76%. LC-MS: M / Z 746.1 (M+).

[0118] 3) Synthesis of intermediate 7-3

[0119] 59.6 g (80 mmol) of intermediate 7-2, 30.1 g (100 mmol) of compound 7-C, 40.8 g (168 mmol) of sodium carbonate, 2.8 g (2.4 mmol) of Pd(PPh3)4, 600 mL of tetrahydrofuran, and 200 mL of water were added to a reaction vessel. The reaction system was purged with nitrogen three times, heated to 80 °C under reflux for 3 hours, cooled, extracted with ethyl acetate, concentrated, subjected to rapid silica gel column chromatography, eluted with toluene, concentrated to remove some solvent, added n-hexane, cooled to crystallize, filtered, and the solid product was subjected to secondary crystallization with THF / EA, filtered, and dried under vacuum to obtain 59.7 g of intermediate 7-3 with an HPLC purity of 99.3% and a yield of 84%. LC-MS: M / Z 888.3 (M+).

[0120] 4) Synthesis of intermediate 7-5

[0121] Under a nitrogen atmosphere, 5.3 g of sodium hydride (60%, 132 mmol) and 600 mL of anhydrous ethylene glycol dimethyl ether (DME) were added to a reaction vessel. The mixture was cooled to 0 °C, and 8.7 g (132 mmol) of malononitrile was added in portions. After stirring for 1 hour, 53.2 g (60 mmol) of compound 7-3 and 3.5 g (3 mmol) of Pd(PPh3)4 were added in portions, and the mixture was heated to reflux for 24 hours. The reaction mixture was cooled to room temperature, concentrated to remove the solvent, dissolved in 800 mL of dichloromethane, and 51.6 g (120 mmol) of [bis(trifluoroacetoxy)iodo]benzene (PIFA) was added in portions. The mixture was reacted at room temperature for 24 hours, and the reaction solution was poured into ice water. The mixture was extracted and separated, the organic phase was concentrated, and silica gel column chromatography (eluent DCM) was performed. The concentrate yielded 37.5 g of intermediate 7-5 with an HPLC purity of 97.8%. The overall yield of intermediates 7-4 and 7-5 was 73%. LC-MS: M / Z 856.6 (M+).

[0122] 5) Synthesis of intermediate 7

[0123] Under a nitrogen atmosphere, 34.2 g (40 mmol) of intermediate 7-5, 4.0 g (60 mmol) of malononitrile, and 600 mL of chloroform were added to a reaction vessel. 15.2 g (80 mmol) of titanium tetrachloride was added dropwise, followed by the addition of 6.3 g (80 mmol) of anhydrous pyridine after 30 minutes. The mixture was heated to reflux for 48 hours. After cooling, the reaction solution was poured into an ice-cold saturated ammonium chloride aqueous solution and stirred for 1 hour. The mixture was filtered, and the filter cake was washed with water and ethanol. The filter cake was then refluxed and washed with chloroform, cooled, filtered again, and vacuum dried. The product was purified by sublimation to give 13.4 g of compound 7 with an HPLC purity of 99.3% and a yield of 37%. LC-MS: M / Z 904.6 (M+).

[0124] Examples 8-9

[0125] Compounds 8-9 shown in Table 2 were prepared according to the preparation method in Example 7.

[0126] Table 2. Raw materials and product compounds

[0127]

[0128] Device Examples

[0129] Example 10

[0130] refer to Figure 1 This embodiment provides a single-layer organic electroluminescent device, the fabrication method of which includes the following steps:

[0131] (1) A transparent ITO film with a thickness of 150 nm is formed on a glass substrate 10 by magnetron sputtering process, which serves as the anode 11.

[0132] (2) A mixture of compound 1 and compound M1 of this application with a mass ratio of 3:97 is deposited on the surface of anode 11 by vacuum evaporation to form a hole injection layer 12 with a thickness of 100 angstroms.

[0133] (3) A compound M1 is deposited on the surface of the hole injection layer 12 to form a first hole transport layer 13 with a thickness of 1000 angstroms.

[0134] (4) A compound M2 is vapor-deposited on the surface of the first hole transport layer 13 to form a second hole transport layer 14 with a thickness of 400 angstroms.

[0135] (5) Compounds M3, M4 and M5 are co-deposited on the surface of the second hole transport layer 14 in a mass ratio of 45:45:10 to form a light-emitting layer 15 with a thickness of 300 angstroms.

[0136] (6) A hole blocking layer 16 with a thickness of 50 angstroms is formed by vapor deposition of compound M6 on the surface of the light-emitting layer 15.

[0137] (7) A mixture of compounds M7 and LiQ with a mass ratio of 98:2 is vapor-deposited on the surface of the hole blocking layer 16 to form an electron transport layer 17 with a thickness of 300 angstroms.

[0138] (8) Magnesium (Mg) and silver (Ag) are mixed and deposited on electron transport layer 17 at a vapor deposition rate of 1:10 to form cathode 18 with a thickness of 1000 angstroms, thus completing the fabrication of organic electroluminescent device.

[0139] Examples 11-18

[0140] Except that, when forming the hole injection layer 12, compounds 2 to 9 of this application were used to replace compound 1, the organic electroluminescent device was prepared using the same method as in Example 10.

[0141] Comparative Example 1

[0142] Except that compound M8 was used instead of compound 1 when forming hole injection layer 12, the organic electroluminescent device was prepared using the same method as in Example 10.

[0143] The structural formulas of the compounds involved in the above preparation methods are shown in Table 3 below:

[0144] Table 3 Structural formulas of related compounds

[0145]

[0146] The operating voltage and current efficiency of the device were measured using a computer-controlled Keithley 2400 test system (test current 10mA / cm). 2 Using a Fostar lifetime measurement system equipped with a power supply and photodiode as detection units, the LT95 lifetime of the device was tested under dark conditions (ambient temperature 25°C, constant current 50mA / cm). 2 LT95 lifetime refers to the time required for the brightness to decrease from its initial brightness to 95%. Each set of examples and comparative examples was produced and tested in the same batch. With the operating voltage, current efficiency, and LT95 lifetime of the device in Comparative Example 1 set at 100%, the operating voltage, current efficiency, and LT95 lifetime are shown in Table 4.

[0147] Table 4 Device Performance Test Results

[0148]

[0149]

[0150] Example 19

[0151] refer to Figure 2 This embodiment provides a stacked organic electroluminescent device, the fabrication method of which includes the following steps:

[0152] (1) A transparent ITO film with a thickness of 150 nm is formed on a glass substrate 100 by magnetron sputtering process, which serves as the anode 110.

[0153] (2) A mixture of compound M1 and compound M8 with a mass ratio of 97:3 is deposited on the surface of anode 110 by vacuum evaporation to form a hole injection layer 200 with a thickness of 100 angstroms.

[0154] (3) A compound M1 is deposited on the surface of the hole injection layer 200 to form a first hole transport layer 311 with a thickness of 200 angstroms.

[0155] (4) A compound M2 is deposited on the surface of the first hole transport layer 311 with a thickness of 200 angstroms to form a second hole transport layer 321 with a thickness of 50 angstroms.

[0156] (5) On the surface of the second hole transport layer 321 with a thickness of 50 angstroms, compounds M3, M4 and M5 are co-deposited in a mass ratio of 45:45:10 to form the first light-emitting layer 400 with a thickness of 300 angstroms.

[0157] (6) A hole blocking layer 500 with a thickness of 50 angstroms is formed by vapor deposition of compound M6 on the surface of the first light-emitting layer 400.

[0158] (7) A mixture of compound M7 and LiQ with a mass ratio of 1:1 is vapor-deposited on the surface of the hole blocking layer 500 of the first layer to form an electron transport layer 610 with a thickness of 100 angstroms.

[0159] (8) A 200-angstrom n-type charge generation layer 710 is formed by vapor deposition of a mixture of compound M9 and metal Yb in a mass ratio of 98:2 on an electron transport layer 610 with a thickness of 100 angstroms.

[0160] (9) A mixture of compound 1 and compound M1 of Example 1 of this application with a mass ratio of 3:97 is deposited on the surface of the n-type charge generation layer 710 to form a p-type charge generation layer 720 with a thickness of 100 angstroms.

[0161] (10) A first hole transport layer 312 of 4000 angstroms is formed by vapor deposition of compound M1 on the p-type charge generation layer 720.

[0162] (11) A second hole transport layer 322 of 300 angstroms is formed by vapor deposition of compound M2 on the surface of a first hole transport layer 312 with a thickness of 4000 angstroms.

[0163] (12) On the surface of the second hole transport layer 322 with a thickness of 300 angstroms, compounds M3, M4 and M5 with a mass ratio of 45:45:10 are co-deposited to form a second light-emitting layer 400 with a thickness of 300 angstroms.

[0164] (13) Compound M6 is deposited on the second light-emitting layer 400 to form a second hole-blocking layer 500 with a thickness of 50 angstroms.

[0165] (14) A mixture of compound M7 and LiQ in a mass ratio of 1:1 is deposited on the hole blocking layer 500 of the second layer to form an electron transport layer 620 of 300 Å, and then a metal Yb of 10 Å is deposited to form an electron injection layer 800.

[0166] (15) Magnesium (Mg) and silver (Ag) are mixed and deposited on the electron injection layer 800 at a vapor deposition rate of 1:10 to form a cathode 900 with a thickness of 1000 angstroms, thus completing the fabrication of the organic electroluminescent device.

[0167] Examples 20-27

[0168] Except that when forming the p-type charge generation layer 720, compound 1 was replaced by compounds 2 to 9 of this application, the organic electroluminescent device was prepared using the same method as in Example 19.

[0169] Comparative Example 2

[0170] Except that compound M8 was used instead of compound 1 when forming the p-type charge generation layer 720, the organic electroluminescent device was prepared using the same method as in Example 19.

[0171] The structural formulas of the compounds involved in the above preparation methods are shown in Table 3.

[0172] The operating voltage, current efficiency, and LT95 lifetime of the devices prepared in Examples 19-27 and Comparative Example 2 were tested using the aforementioned device testing methods. Taking the operating voltage, current efficiency, and LT95 lifetime of the device in Comparative Example 2 as 100%, the operating voltage, current efficiency, and LT95 lifetime are shown in Table 5.

[0173] Table 5 Device Performance Test Results

[0174] Devices Charge generation layer material Operating voltage Current efficiency LT95 lifespan Comparative Example 2 Compound M8 100％ 100％ 100％ Example 19 Compound 1 90％ 130％ 135％ Example 20 Compound 2 90％ 125％ 130％ Example 21 Compound 3 95％ 120％ 125％ Example 22 Compound 4 90％ 110％ 115％ Example 23 Compound 5 90％ 125％ 120％ Example 24 Compound 6 90％ 130％ 130％ Example 25 Compound 7 95％ 115％ 110％ Example 26 Compound 8 90％ 130％ 125％ Example 27 Compound 9 95％ 110％ 120％

[0175] As shown in Tables 4 and 5, compared with compound M8, when organic electroluminescent devices are fabricated using the organic compounds of this application as hole injection layer materials or charge generation layer materials, the operating voltage is reduced by at least 5%, and the current efficiency and lifetime are improved by at least 10%. Therefore, the organic compounds of this application can improve the performance of organic electroluminescent devices.

[0176] The above description of the embodiments is intended to enable those skilled in the art to understand and apply this application. It will be apparent to those skilled in the art that various modifications can be easily made to these embodiments, and the general principles described herein can be applied to other embodiments without creative effort. Therefore, this application is not limited to the embodiments described herein, and any improvements and modifications made by those skilled in the art based on the disclosure of this application without departing from the scope and spirit of this application are within the scope of this application.

Claims

1. An organic compound, characterized in that, The structural formula of the organic compound is shown in Formula I or Formula II: In Equations I and II: X and Y are selected from the group consisting of O, S, Se and NR each time they appear, either the same or different, where R is selected from the group consisting of: acyl, carbonyl, carboxylic acid, ester, cyano, isocyano, thiocyano, isocyanate, pentafluorosulfonyl, sulfinyl, sulfonyl, phosphoxy, partially fluorinated or perfluorinated C1-C12 alkyl, partially fluorinated or perfluorinated C3-C12 cycloalkyl, substituted or unsubstituted C6-C24 aryl, substituted or unsubstituted C3-C24 heteroaryl; R1~R 12 When present, they are selected from the group consisting of, either identically or differently from, hydrogen, deuterium, halogen, nitrosyl, nitro, acyl, carbonyl, carboxylic acid, ester, cyano, isocyanate, thiocyanate, isocyanate, pentafluorosulfonyl, sulfinyl, sulfonyl, phosphooxy, substituted or unsubstituted C6-C24 aryl, substituted or unsubstituted C3-C24 heteroaryl; A1, A2, and A3 are selected from, either identically or differently from, formula III or formula IV: When Ar1 is present, it is selected from substituted or unsubstituted C6-C24 aryl groups and substituted or unsubstituted C3-C24 heteroaryl groups; When R', R”, and R”' are present, they are selected from electron-withdrawing groups, either in the same or different ways.

2. The organic compound according to claim 1, characterized in that, Equation I or Equation II satisfies any one or more of the following characteristics: (1) In the R, the substituent is selected from one or more of deuterium, nitro, cyano, halogen, partially fluorinated or perfluorinated C1 to C12 alkyl, partially fluorinated or perfluorinated C1 to C6 alkoxy, wherein the substituents are the same or different from each other; (2) The R1~R 12 In this context, the substituents are selected from one or more of the following: deuterium, halogen, nitroso, nitro, acyl, carbonyl, carboxylic acid, ester, cyano, isocyano, thiocyano, isocyanate, pentafluorosulfonyl, sulfinyl, sulfonyl, phosphoxy, partially fluorinated or perfluorinated C1-C12 alkyl, and partially fluorinated or perfluorinated C1-C6 alkoxy, wherein the substituents may be the same as or different from each other; (3) In the Ar1, the substituent is selected from one or more of deuterium, nitro, cyano, halogen, partially fluorinated or perfluorinated C1 to C12 alkyl, partially fluorinated or perfluorinated C1 to C6 alkoxy, wherein the substituents are the same or different from each other; (4) The electron-withdrawing group is selected from the group consisting of: halogen, nitroso, nitro, acyl, carbonyl, carboxylic acid, ester, cyano, isocyano, thiocyano, isocyanate, pentafluorosulfonyl, sulfinyl, sulfonyl, phosphoxy, and haloalkyl.

3. The organic compound according to claim 1, characterized in that, The organic compound has the structural formula shown in Formula I, and Formula I satisfies any one or more of the following characteristics: 1) X is selected from O, S, and Se; 2) R1 to R 12 The radicals are selected from hydrogen, fluorine, cyano, isocyano, thiocyano, substituted or unsubstituted phenyl groups, either identically or differently; further, R1 to R... 12 In this context, the substituents are preferably selected from one or more of fluorine, cyano, isocyano, and thiocyano, wherein the substituents may be the same or different from each other; preferably, R1 to R2 are... 12 At least two of them are groups with electron-withdrawing groups; 3) A1, A2 and A3 are selected from Formula IV in the same or different ways; preferably, in Formula IV, R” and R”' are selected from cyano, isocyano and thiocyano in the same or different ways.

4. The organic compound according to claim 3, characterized in that, The organic compound is represented by any of the following structural formulas: Among them, R5~R 12 When present, they are selected from hydrogen and fluorine, either identically or differently.

5. The organic compound according to claim 4, characterized in that, The organic compounds are selected from the following group:

6. The organic compound according to claim 1, characterized in that, The organic compound has the structural formula shown in Formula II, and Formula II satisfies any one or more of the following characteristics: A) X and Y are selected from O, S, and Se each time they appear, whether the same or different. B) R1 to R8 are selected from hydrogen, fluorine, cyano, isocyano, thiocyano, substituted or unsubstituted phenyl groups, either identically or differently; further, in R1 to R8, the substituents are preferably one or more of fluorine, cyano, isocyano, and thiocyano, wherein the substituents are identical or different from each other; preferably, at least two of R1 to R8 are groups having electron-withdrawing groups. C) A1, A2 and A3 are selected from Formula IV in the same or different ways; preferably, in Formula IV, R” and R”' are selected from cyano, isocyano and thiocyano in the same or different ways.

7. The organic compound according to claim 6, characterized in that, The organic compound is represented by any of the following structural formulas: Among them, R5 to R8 are selected from fluorine and cyano groups, either the same or different.

8. The organic compound according to claim 7, characterized in that, The organic compounds are selected from the following group:

9. An organic layer, characterized in that, It includes the organic compound according to any one of claims 1 to 8.

10. Use of the organic compound according to any one of claims 1 to 8 or the organic layer according to claim 9 in an organic electroluminescent device.

11. An organic electroluminescent device, characterized in that, It includes a first electrode, a second electrode, and an organic layer as described in claim 9 located between the first electrode and the second electrode.

12. The organic electroluminescent device according to claim 11, characterized in that, The organic layer includes a hole injection layer and / or a charge generation layer, wherein the hole injection layer and / or charge generation layer comprises an organic compound according to any one of claims 1 to 8.

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