An organic electroluminescent compound and its application

Abstract

The present invention provides an organic electroluminescent compound and its application. The structure of the organic electroluminescent compound is shown in Formula I, wherein L, L<supgt;1< / supgt>, and L<supgt;2< / supgt> are independently selected from any one of a single bond, a substituted or unsubstituted C6-C30 arylene group, and a substituted or unsubstituted C3-C30 heteroarylene group; Ar<supgt;1< / supgt> and Ar<supgt;2< / supgt> are independently selected from hydrogen, deuterium, halogen, cyano group, a substituted or unsubstituted C1-C30 alkyl group, a substituted or unsubstituted C3-C30 cycloalkyl group, a substituted or unsubstituted C6-C60 aryl group, and a substituted or unsubstituted C3-C60 heteroaryl group. The organic electroluminescent device made of the organic electroluminescent compound provided by the present invention has the characteristics of high current efficiency and long service life.

Description

Technical Field

[0001] The present invention belongs to the field of organic electroluminescent materials, and particularly relates to an organic electroluminescent compound and its application, and more particularly to an organic electroluminescent compound with high current efficiency and its application. Background Art

[0002] Recently, with the increase in the size of displays, people have become increasingly interested in flat display elements that occupy less space. In this field, the technology of organic light-emitting displays including organic light-emitting diodes (OLEDs) as flat display elements has developed rapidly. An organic light-emitting diode emits light by annihilating a pair of holes and electrons generated by injecting holes and electrons from a hole injection electrode (anode) and an electron injection electrode (cathode) into an emission layer between the anode and the cathode. Such an organic light-emitting diode can be formed on a flexible transparent substrate such as plastic, can be operated at a low voltage, consumes relatively low power, and has good color reproduction.

[0003] CN108780853A discloses a variety of host materials and an organic electroluminescent device comprising the variety of host materials. By including a variety of host compounds in a specific combination, the organic electroluminescent device can have improved lifetime properties. The structure of the host compound is as follows:

[0004]

[0005] CN108290875A discloses a new compound capable of improving the luminous efficiency, stability and lifetime of an element, and an organic electronic element and an electronic device using the compound. By using this compound, the high luminous efficiency, low driving voltage, and high heat resistance of the element can be improved, and the color purity and lifetime can be increased. The structure of the compound is as follows:

[0006]

[0007] Since the requirements for organic electroluminescent devices by people are gradually increasing, the demand for materials for new organic electroluminescent devices is more urgent. Therefore, how to provide a material for an organic electroluminescent device with high efficiency and long lifetime has become an urgent problem to be solved. Summary of the Invention

[0008] Aiming at the deficiencies of the prior art, the purpose of the present invention is to provide an organic electroluminescent compound and its application, and more particularly to provide an organic electroluminescent compound with high current efficiency and its application. The organic electroluminescent device made of the organic electroluminescent compound provided by the present invention has the characteristics of high current efficiency and long service life.

[0009] To achieve the purpose of this invention, the present invention adopts the following technical solutions:

[0010] In a first aspect, the present invention provides an organic electroluminescent compound, and the structure of the organic electroluminescent compound is shown in Formula I:

[0011]

[0012] Wherein L, L 1 , L 2 are independently selected from any one of a single bond, a substituted or unsubstituted C6-C30 arylene group, and a substituted or unsubstituted C3-C30 heteroarylene group.

[0013] Ar 1 , Ar 2 are independently selected from any one of hydrogen, deuterium, halogen, cyano, a substituted or unsubstituted C1-C30 alkyl group, a substituted or unsubstituted C3-C30 cycloalkyl group, a substituted or unsubstituted C6-C60 aryl group, and a substituted or unsubstituted C3-C60 heteroaryl group.

[0014] The organic electroluminescent device made of the organic electroluminescent compound with the above specific structure has the characteristics of high current efficiency and long service life.

[0015] Preferably, the organic electroluminescent compound has a structural general formula shown in any one of the following:

[0016] Preferably Wherein, the protection scopes of L, L 1 , L 2 , Ar 1 , Ar 2 are the same as those above.

[0017] Preferably, L, L 1 , L 2 are independently selected from a single bond or a phenylene group.

[0018] Preferably, L 2 is selected from a dibenzofuranyl group or a dibenzothiophenyl group.

[0019] Preferably, L 2 is selected from a dibenzofuranyl group.

[0020] Preferably, Ar 1 is selected from hydrogen, deuterium, halogen, or any one of the following substituted or unsubstituted groups: phenyl, biphenyl, terphenyl, naphthyl, phenyl-substituted naphthyl, naphthyl-substituted phenyl, dibenzofuranyl, dibenzothiophenyl, phenyl-substituted carbazolyl, 9,9'-dimethylfluorenyl (selected from ), 9,9'-diphenylfluorenyl (selected from ) or spirobifluorenyl.

[0021] Preferably, Ar 2 It is selected from hydrogen, deuterium, halogen, methyl, deuterated methyl or any one of the following substituted or unsubstituted groups: phenyl, biphenyl, naphthyl, phenyl-substituted naphthyl, naphthyl-substituted phenyl, dibenzofuranyl or 9,9'-dimethylfluorenyl.

[0022] Preferably, the substituted substituent group is selected from any one of deuterium, halogen, methyl or phenyl.

[0023] Preferably, the organic electroluminescent compound is selected from any one of the following structures:

[0024]

[0025]

[0026]

[0027]

[0028]

[0029] The above organic electroluminescent compound can be prepared illustratively by a method comprising the following steps:

[0030] When L is selected from a single bond, coupling to obtain the organic electroluminescent compound;

[0031] When L is selected from substituted or unsubstituted C6-C30 arylene, substituted or unsubstituted C3-C30 heteroarylene, and Coupled with coupling to obtain the organic electroluminescent compound.

[0032] Among them, X, X 1 Selected from halogen, L 1 , L 2 ,Ar 1 ,Ar 2 Having the same limited range as above, Ar 9 Any one selected from a substituted or unsubstituted C6-C30 arylene group and a substituted or unsubstituted C3-C30 heteroarylene group.

[0033] In a second aspect, the present invention provides use of the organic electroluminescent compound as described above in the preparation of an organic electroluminescent diode.

[0034] In a third aspect, the present invention also provides an organic light-emitting diode, which includes a first electrode, a second electrode, and an organic layer between the first electrode and the second electrode, and the material of the organic layer includes at least one of the organic electroluminescent compounds described above.

[0035] Preferably, the organic layer includes a hole transport layer, a light-emitting auxiliary layer, a light-emitting layer, a hole blocking layer, and an electron transport layer that are sequentially stacked.

[0036] Preferably, the hole transport layer contains the organic electroluminescent compound described above.

[0037] Preferably, the light-emitting auxiliary layer contains the organic electroluminescent compound described above.

[0038] Preferably, the light-emitting layer contains a host material and a guest material, the guest material is an Ir-containing complex, and the host material contains an aromatic amine compound.

[0039] Preferably, the host material further contains a triazine compound.

[0040] Preferably, the structure of the aromatic amine compound is as shown in formula P:

[0041]

[0042] wherein, L 6 、L 7 、L 8 are independently selected from any one of a single bond, a substituted or unsubstituted C6-C30 arylene group, and a substituted or unsubstituted C3-C30 heteroarylene group.

[0043] Ar 6 、Ar 7 、Ar 8 are independently selected from any one of hydrogen, deuterium, halogen, cyano group, substituted or unsubstituted C1-C30 alkyl group, substituted or unsubstituted C3-C30 cycloalkyl group, substituted or unsubstituted C6-C60 aryl group, and substituted or unsubstituted C3-C60 heteroaryl group.

[0044] Preferably, the structure of the triazine compound is as shown in formula N:

[0045]

[0046] where L 3 、L 4 、L 5 are independently selected from any one of a single bond, a substituted or unsubstituted C6-C30 arylene group, and a substituted or unsubstituted C3-C30 heteroarylene group.

[0047] Ar3 、Ar 4 、Ar 5 are independently selected from any one of hydrogen, deuterium, halogen, cyano, substituted or unsubstituted C1-C30 alkyl, substituted or unsubstituted C3-C30 cycloalkyl, substituted or unsubstituted C6-C60 aryl, and substituted or unsubstituted C3-C60 heteroaryl.

[0048] Preferably, L 3 、L 4 、L 5 、L 6 、L 7 、L 8 are independently selected from a single bond or phenylene.

[0049] Preferably, Ar 3 、Ar 4 、Ar 5 、Ar 6 、Ar 7 、Ar 8 are independently selected from hydrogen, deuterium, halogen, and the following substituted or unsubstituted groups: phenyl, biphenyl, terphenyl, naphthyl, naphthyl-substituted phenyl, phenyl-substituted naphthyl, dibenzofuranyl, dibenzothiophenyl, 9,9'-dimethylfluorenyl, 9,9'-diphenylfluorenyl, spirobifluorenyl, carbazolyl, or pyridyl.

[0050] Preferably, at least one of Ar 6 、Ar 7 、Ar 8 is selected from substituted or unsubstituted carbazolyl.

[0051] Preferably, only one of Ar 6 、Ar 7 、Ar 8 is selected from substituted or unsubstituted carbazolyl.

[0052] Preferably, at least one of Ar 3 、Ar 4 、Ar 5 is selected from dibenzofuranyl.

[0053] Preferably, only one of Ar 3 、Ar 4 、Ar 5 is selected from dibenzofuranyl.

[0054] Preferably, at least one of Ar 3 、Ar 4 、Ar 5 is selected from 9,9'-dimethylfluorenyl or 9,9'-diphenylfluorenyl or spirobifluorenyl.

[0055] Preferably, Ar 3 、Ar 4 、Ar 5 Only one of them is selected from 9,9'-dimethylfluorenyl, 9,9'-diphenylfluorenyl or spirobifluorenyl.

[0056] Preferably, the substituted substituent group is selected from any one of deuterium, halogen, cyano, methyl, tert-butyl, phenyl, pyridyl, naphthyl or biphenyl.

[0057] Preferably, the arylamine compound is selected from any one of the following structures:

[0058]

[0059]

[0060] Preferably, the triazine compound is selected from any one of the following structures:

[0061]

[0062]

[0063]

[0064] The arylamine compound and triazine compound with the above specific structures, when used in combination with the above organic electroluminescent compound, can further improve the current efficiency and service life of the fabricated organic electroluminescent device.

[0065] Compared with the prior art, the present invention has the following beneficial effects:

[0066] The present invention provides an organic electroluminescent compound with a specific structure. The fabricated organic electroluminescent device has the characteristics of high current efficiency and long service life; by selecting arylamine compounds and triazine compounds with specific structures and using them in combination with the above organic electroluminescent compound, the current efficiency and service life of the fabricated organic electroluminescent device can be further improved. Description of the Drawings

[0067] Figure 1 It is a schematic structural diagram of the organic electroluminescent device in the application example, where 1 - substrate, 2 - anode, 3 - hole injection layer, 4 - hole transport layer, 5 - light-emitting auxiliary layer, 6 - light-emitting layer, 7 - electron transport layer, 8 - electron injection layer, 9 - cathode. Detailed Embodiments

[0068] The technical solutions of the present invention will be further described below through specific embodiments. Those skilled in the art should understand that the embodiments are only for helping to understand the present invention and should not be regarded as specific limitations on the present invention.

[0069] As used in the present invention, the term "organic electroluminescent compound" means a compound that can be used in an organic electroluminescent device and can be included in any layer constituting the organic electroluminescent device as needed.

[0070] As used in the present invention, the term "organic electroluminescent material" refers to a material that can be used in an organic electroluminescent element and can contain at least one compound. If necessary, the organic electroluminescent material can be included in any layer constituting the organic electroluminescent element. For example, the organic electroluminescent material can be a hole injection material, a hole transport material, an electron blocking material, a luminescence assisting material, a luminescent layer material (including a host material and a doping material), an electron buffer material, a hole blocking material, an electron transport material, an electron injection material, etc.

[0071] The organic electroluminescent material disclosed in the present invention can contain at least one compound represented by Formula 1. Although not limited thereto, the compound having Formula 1 can be included in the hole transport layer, and / or the compound having Formula 1 can be included in the luminescence assisting layer, and is not limited thereto.

[0072] Hereinafter, each layer of the organic electroluminescent element composed of the compound of Formula 1 of the present invention will be described.

[0073] Substrate

[0074] An organic EL element is usually fabricated on a light-transmissive substrate. The light-transmissive substrate is a substrate for supporting the organic EL element, and the transmittance of light in the visible region of wavelengths 400 - 700 nm is preferably 50% or more, and a smooth substrate is further preferably used.

[0075] Examples of such a light-transmissive substrate include a glass plate, a synthetic resin plate, etc. Examples of the glass plate include plates formed of soda-lime glass, barium- and strontium-containing glass, lead glass, aluminosilicate glass, borosilicate glass, borosilicate barium glass, quartz, etc. In addition, examples of the synthetic resin plate include plates of polycarbonate resin, acrylic resin, polyethylene terephthalate resin, polyether sulfide resin, polysulfone resin, etc.

[0076] Anode

[0077] The anode functions to inject holes into the hole transport layer or the luminescent layer, and it is effective to have a work function of 4 eV or more (preferably 4.45 eV or more). Specific examples of the anode material include carbon, aluminum, vanadium, iron, cobalt, nickel, tungsten, silver, gold, platinum, palladium, etc. and their alloys, metal oxides such as tin oxide and indium oxide used in ITO substrates and NESA substrates, and organic conductive resins such as polythiophene or polypyrrole.

[0078] Cathode

[0079] As the cathode, a cathode using a metal, alloy, conductive compound, or a mixture thereof having a small work function (less than 4 eV) as an electrode material can be used. As specific examples of such electrode materials, magnesium, calcium, tin, lead, titanium, yttrium, lithium, ruthenium, manganese, aluminum, lithium fluoride, etc. and their alloys can be used, and there is no particular limitation on them. As representative examples of the alloy, magnesium / silver, magnesium / indium, lithium / aluminum, etc. can be cited, and there is no particular limitation on them. The ratio of the alloy is controlled by the temperature, atmosphere, vacuum degree, etc. of the evaporation source, and an appropriate ratio is selected. The anode and cathode can also be formed by two or more layers as needed.

[0080] Light-emitting layer

[0081] The light-emitting layer has functions of carrier injection, carrier transport, and light emission. The light-emitting layer materials include host materials and guest materials, and the guest materials include phosphorescent guest materials, fluorescent guest materials, TADF guest materials, etc.

[0082] Hole injection layer / hole transport layer

[0083] The hole injection layer / hole transport layer is a layer that helps inject holes into the light-emitting layer and transport the holes to the light-emitting region. It has a large hole mobility and an ionization energy usually as small as 5.7 eV or less. As such a hole injection layer / hole transport layer, a material that transports holes to the light-emitting layer with a lower electric field strength is preferred. More preferably, the hole mobility is, for example, 10 4 -10 6 V / cm of electric field is 10 -4 cm 2 / V·s or more. Examples of materials known as hole transport layer materials include bis(N-(1-naphthyl-n-phenyl))benzidine (α-NPD), N,N'-di(naphthalen-1-yl)-N,N'-biphenylbenzidine (NPB), or N,N'-biphenyl-N,N'-bis(3-methylphenyl)-1,1'-biphenyl-4,4'-diamine (TPD), etc.

[0084] Light-emitting auxiliary layer

[0085] The light-emitting auxiliary layer is used to reduce the potential barrier for holes to transport to the light-emitting layer, and also helps to block electrons, preventing electrons from overflowing from the light-emitting layer to the hole transport layer and improving the light-emitting efficiency.

[0086] Electron buffer layer

[0087] The electron buffer layer helps to block holes in the light-emitting layer and also helps to transport electrons to the light-emitting layer to promote the combination of electrons and holes in the light-emitting layer and improve the light-emitting efficiency.

[0088] Electron injection layer / electron transport layer

[0089] The electron injection layer / electron transport layer is a layer that helps inject electrons into the light-emitting layer and transport electrons to the light-emitting region, and has a large electron mobility. The adhesion improvement layer is an electron injection layer containing a material with particularly good adhesion to the cathode.

[0090] Specific examples of the material used in the electron injection layer include, but are not particularly limited to, LiF, Liq, Li2O, BaO, NaCl, CsF, etc.

[0091] The functions of the OLED can be achieved by combining the various layers described above, or some layers can be completely omitted. It can also include other layers not explicitly described. Within each layer, a single material or a mixture of multiple materials can be used to achieve optimal performance. Any functional layer can include several sub-layers. For example, the light-emitting layer can have two different light-emitting materials to achieve the desired emission spectrum.

[0092] To form each layer of the organic electroluminescent device disclosed in the present invention, dry film-forming methods such as vacuum evaporation, sputtering, plasma, ion plating methods, etc., or wet film-forming methods such as inkjet printing, nozzle printing, slot coating, spin coating, dip coating, flow coating methods, etc. can be used. The organic electroluminescent compounds disclosed in the present invention can be formed into a film by co-evaporation method or mixture evaporation method.

[0093] The product is applied in optoelectronics, medicine, biotechnology, optical fibers, lighting devices, electrophotographic photoreceptors, photoelectric converters, organic solar cells, switching elements, organic light-emitting field-effect transistors, image sensors, or dye lasers.

[0094] Definition of substituent terms

[0095] As used in the present invention, the term "halogen" can include fluorine, chlorine, bromine, or iodine.

[0096] As used in the present invention, the term "C1-C30 alkyl" refers to a monovalent substituent derived from a straight-chain or branched-chain saturated hydrocarbon having 1 to 30 carbon atoms, and examples thereof include, but are not limited to, methyl, ethyl, propyl, isobutyl, sec-butyl, tert-butyl, pentyl, isopentyl, and hexyl.

[0097] As used in the present invention, the term "C3-C30 cycloalkyl" refers to a monocyclic hydrocarbon or polycyclic hydrocarbon derived from a ring main-chain hydrocarbon having 1 to 30 carbon atoms, and the cycloalkane can include cyclopropyl, cyclobutyl, adamantyl, etc.

[0098] In the present invention, aryl and arylene include monocyclic, polycyclic or fused-ring aryl, the rings of which may be interrupted by short non-aromatic units and may include a spiro structure, including but not limited to phenyl, biphenyl, terphenyl, naphthyl, phenanthryl, anthryl, fluorenyl, spirobifluorenyl, etc.

[0099] In the present invention, heteroaryl and heteroarylene include monocyclic, polycyclic or fused-ring heteroaryl, the rings of which may be interrupted by short non-aromatic units, and the heteroatoms include nitrogen, oxygen and sulfur. It includes but not limited to furyl, phenylthio, pyrrolyl, imidazolyl, pyrazolyl, thiazolyl, thiadiazolyl, isothiazolyl, isoxazolyl, oxazolyl, oxadiazolyl, triazinyl, tetrazinyl, triazolyl, tetrazolyl, furazanyl, pyridyl, pyrazinyl, pyrimidinyl, pyridazinyl, benzofuryl, benzothienyl, isobenzofuryl, dibenzofuryl, dibenzothienyl, benzimidazolyl, benzothiazolyl, benzoisothiazolyl, benzoisoxazolyl, benzoxazolyl, isoindolyl, indolyl, indazolyl, benzothiadiazolyl, quinolinyl, isoquinolinyl, cinnolinyl, quinazolinyl, quinoxalinyl, carbazolyl, phenoxazinyl, phenothiazinyl, phenanthridinyl, benzodioxolyl, dihydroacridinyl, and their derivatives, etc.

[0100] As used in the present invention, the term "substituted" means that a hydrogen atom in a compound is replaced by another substituent. The position is not limited to a specific position as long as the hydrogen at this position can be replaced by a substituent. When there are two or more substituents, the two or more substituents may be the same or different.

[0101] As used in the present invention, unless otherwise specified, hydrogen atoms include protium, deuterium and tritium.

[0102] In the present invention, the range of the number of carbon atoms is defined in the definition of the group, and the number of carbon atoms is any integer within the defined range. For example, C6-C60 aryl means that the number of carbon atoms of the aryl can be any integer within the range of 6-60, such as 6, 8, 10, 15, 20, 30, 35, 40, 45, 50, 55 or 60, etc.

[0103] Example 1

[0104] This example provides an organic electroluminescent compound, and the synthesis route is as follows:

[0105]

[0106] The specific steps are as follows:

[0107] Synthesis of Compound 1: Add raw material 1 (10 mmol), raw material 2 (10 mmol), sodium tert-butoxide (15 mmol), tris(dibenzylideneacetone)dipalladium(0) (0.2 mmol), (8% eq) S-phos (0.8 mmol) and 80 mL of toluene into a 250 mL two-necked flask filled with N2, and then reflux and stir. After cooling to room temperature, extract the organic layer with ethyl acetate and H2O. The extracted organic layer is dried over MgSO4 and filtered. Concentrate the filtrate under reduced pressure and purify it by silica gel column chromatography (DCM / hexane), and then perform recrystallization purification using a mixed solvent of DCM / acetone to obtain Compound 1 (5.03 g, yield: 73%).

[0108] The characterization data are as follows:

[0109] MS(APCI) m / z [M+H] + : 690.47

[0110] Example 2

[0111] This example provides an organic electroluminescent compound, and the synthesis route is as follows:

[0112]

[0113] The specific steps are as follows:

[0114] Synthesis of Compound 5: The same as the synthesis of Compound 1, except that raw material 3 is used to replace raw material 2, to obtain Compound 5 (5.18 g, yield: 69%).

[0115] The characterization data are as follows:

[0116] MS(APCI) m / z [M+H] + : 752.68

[0117] Example 3

[0118] This example provides an organic electroluminescent compound, and the synthesis route is as follows:

[0119]

[0120] The specific steps are as follows:

[0121] Synthesis of Compound 12: The same as the synthesis of Compound 1, except that raw material 4 is used to replace raw material 2, to obtain Compound 12 (5.03 g, yield: 67%).

[0122] The characterization data are as follows:

[0123] MS(APCI) m / z [M+H] + : 752.49

[0124] Example 4

[0125] This example provides an organic electroluminescent compound, and the synthesis route is as follows:

[0126]

[0127] The specific steps are as follows:

[0128] Synthesis of Compound 15: Similar to the synthesis of Compound 1, except that raw material 5 is used instead of raw material 2, to obtain Compound 15 (4.90 g, yield: 64%).

[0129] The characterization data are as follows:

[0130] MS(APCI) m / z [M+H] + : 766.46

[0131] Example 5

[0132] This example provides an organic electroluminescent compound, and the synthesis route is as follows:

[0133]

[0134] The specific steps are as follows:

[0135] Synthesis of Intermediate 45-1: In a 250 ml three-necked flask, add raw material 6 (10 mmol), raw material 8 (10 mmol), 60 mL of toluene, 20 mL of ethanol, 20 mL of water, palladium tetrakis(triphenylphosphine) (0.4 mmol), potassium carbonate (20 mmol), heat to 80 °C, react for 5 hours, track the reaction by TLC until the raw materials react completely and then stop the reaction. After cooling to room temperature, extract the organic layer with ethyl acetate and H2O. The extracted organic layer is dried over MgSO4 and filtered. The filtrate is concentrated under reduced pressure and purified by silica gel column chromatography (DCM / hexane) to obtain Intermediate 45-1 (1.82 g, yield: 40%).

[0136] Synthesis of Compound 45: Similar to the synthesis of Compound 1, except that raw material 8 is used instead of raw material 2, and Intermediate 45-1 is used instead of raw material 1, to obtain Compound 45 (4.51 g, yield: 60%).

[0137] The characterization data are as follows:

[0138] MS(APCI) m / z [M+H] + : 752.51

[0139] Example 6

[0140] This example provides an organic electroluminescent compound, and the synthesis route is as follows:

[0141]

[0142] The specific steps are as follows:

[0143] Synthesis of Intermediate 49-1: The same as the synthesis of Compound 1, except that raw material 9 is used to replace raw material 2, and raw material 11 is used to replace raw material 1, to obtain Intermediate 49-1 (2.39 g, yield: 48%).

[0144] Synthesis of Compound 49: The same as the synthesis of Compound 1, except that Intermediate 49-1 is used to replace raw material 2, to obtain Compound 49 (5.97 g, yield: 67%).

[0145] The characterization data are as follows:

[0146] MS(APCI) m / z [M+H] + : 842.30

[0147] Example 7

[0148] This example provides an organic electroluminescent compound, and the synthesis route is as follows:

[0149]

[0150] The specific steps are as follows:

[0151] Synthesis of Intermediate 52-1: The same as the synthesis of Compound 1, except that raw material 12 is used to replace raw material 2, and raw material 13 is used to replace raw material 1, to obtain Intermediate 52-1 (2.85 g, yield: 44%).

[0152] Synthesis of Compound 52: The same as the synthesis of Compound 1, except that Intermediate 52-1 is used to replace raw material 2, to obtain Compound 52 (6.04 g, yield: 61%).

[0153] The characterization data are as follows:

[0154] MS(APCI) m / z [M+H] + : 992.27

[0155] Example 8

[0156] This example provides an organic electroluminescent compound, and the synthesis route is as follows:

[0157]

[0158] The specific steps are as follows:

[0159] Synthesis of Intermediate 61-1: 38.3 mL of phenylmagnesium bromide (2.9 M in THF) was added to a 250 mL three-necked flask equipped with a magnetic stirrer. 10 g of 9-fluorenone was dissolved in 100 mL of tetrahydrofuran solution and added to a constant pressure dropping funnel. The system was purged with nitrogen three times. At 0 °C, the tetrahydrofuran solution of 9-fluorenone was added dropwise. After the addition, the reaction was allowed to proceed at room temperature. The reaction was monitored by TLC until the raw materials were completely reacted and then the reaction was stopped. After the reaction, an appropriate amount of saturated aqueous ammonium chloride solution was added to quench the reaction. The mixture was allowed to stand and layer using a separatory funnel. The organic phase was collected, and the aqueous phase was extracted three times with dichloromethane. The organic phases were combined and dried over anhydrous sodium sulfate. Purification by silica gel column chromatography (DCM / hexane) gave Intermediate 61-1 (12.8 g, yield 52%).

[0160] Synthesis of Intermediate 61-2: Intermediate 61-1 (12.8 g) and Raw Material 16 (12.8 g) were added to a 250 mL three-necked flask equipped with a magnetic stirrer. The mixture was dissolved in 128 mL of dichloromethane, and the system was purged with nitrogen three times. Under nitrogen protection, 15.4 g of Eaton's reagent was added dropwise at room temperature. The reaction was monitored by TLC until the raw materials were completely reacted and then the reaction was stopped. After the reaction, the mixture was poured into saturated brine. The mixture was allowed to stand and layer using a separatory funnel. The organic phase was collected, and the aqueous phase was extracted three times with dichloromethane. The organic phases were combined and dried over anhydrous sodium sulfate. Purification by silica gel column chromatography (DCM / hexane) gave Intermediate 61-2 (8 g, yield 46%).

[0161] Synthesis of Compound 61: Intermediate 61-2 (8 g), Raw Material 1 (8 g), Pd2(dba)3 (0.3 g), SPhos (0.3 g), t-BuONa (3 g), and 80 mL of toluene were added to a 250 mL three-necked flask equipped with a magnetic stirrer and a reflux condenser. The system was purged with nitrogen three times. Under nitrogen protection, the reaction was carried out at 110 °C. The reaction was monitored by TLC until the raw materials were completely reacted (2 h) and then the reaction was stopped. After the reaction, water was added to quench the reaction. The mixture was extracted with ethyl acetate and dried over anhydrous sodium sulfate. Purification by silica gel column chromatography (DCM / hexane) gave Compound 61 (11 g, yield 82%).

[0162] The characterization data are as follows:

[0163] MS(APCI) m / z [M+H] + : 842.37

[0164] Application Examples 1-15 and Comparative Application Examples 1-2

[0165] Application Examples 1-15 and Comparative Application Examples 1-2 respectively provide an OLED having the following structure stacked in sequence: a substrate (indium tin oxide (ITO) coated glass substrate) / hole injection layer (HIL) / hole transport layer (HTL-1) / luminescence assisting layer (HTL-2) / emission layer (EML) / electron transport layer (ETL) / optional electron injection layer (EIL), and finally a cathode. The schematic structural diagram is as Figure 1 shown, where 1 is the substrate, 2 is the anode, 3 is the hole injection layer, 4 is the hole transport layer, 5 is the luminescence assisting layer, 6 is the emission layer, 7 is the electron transport layer, 8 is the electron injection layer, and 9 is the cathode.

[0166] The materials used are as follows:

[0167]

[0168] The preparation steps are as follows:

[0169] 1) Substrate cleaning:

[0170] The glass substrate coated with the ITO transparent electrode is ultrasonically treated in an aqueous cleaning agent (the composition and concentration of the aqueous cleaning agent: 10 wt% ethylene glycol solvent, 1 wt% triethanolamine), rinsed in deionized water, ultrasonically degreased in an acetone-ethanol mixed solvent (volume ratio 1:1), baked in a clean environment until all moisture is completely removed, and then cleaned with ultraviolet light and ozone;

[0171] 2) Evaporation:

[0172] Place the above-mentioned glass substrate with the anode in a vacuum chamber, evacuate to between 1×10 -6 and 2×10 -4 Pa, and vacuum evaporate the hole injection layer (HIL) material on the above-mentioned anode layer film in a co-evaporation manner. The evaporation rates of PD and NPB are adjusted according to the mass ratio, and the total evaporation rate is 0.1 nm / s, and the evaporation thickness is 10 nm;

[0173] 3) Evaporate the hole transport layer (HTL-1) on the hole injection layer, with an evaporation rate of 0.1 nm / s and an evaporation film thickness of 60 nm;

[0174] 4) Evaporate the luminescence assisting layer (HTL-2, using the organic electroluminescent compounds and REF-1 provided in Examples 1-9 respectively) on the hole transport layer, with an evaporation rate of 0.1 nm / s and an evaporation film thickness of 20 nm;

[0175] 5) Evaporate the emission layer (EML) on the luminescence assisting layer, and vacuum evaporate the host material and the guest material of the emission layer in a co-evaporation manner. The evaporation rates of the host material and the guest material are adjusted according to the mass ratio, and the total evaporation rate is 0.1 nm / s, and the total evaporation film thickness is 30 nm;

[0176] 6) A layer of electron transport layer (ETL) is vacuum-evaporated on the light-emitting layer. Adjust the evaporation rate according to the mass ratio of compound ET to LiQ. The total evaporation rate is 0.1 nm / s, and the total film thickness of evaporation is 30 nm;

[0177] 7) A layer of electron injection layer (EIL) is vacuum-evaporated on the electron transport layer. Its evaporation rate is 0.05 nm / s, and the total film thickness of evaporation is 1 nm;

[0178] 8) Evaporate the cathode on the electron injection layer. For metal Al, the total evaporation rate is 0.1 nm / s, and the total film thickness of evaporation is 100 nm.

[0179] The materials and parameters of each application example are as follows:

[0180]

[0181]

[0182]

[0183] After that, use a PR 650 spectral scanning luminance meter and a Keithley K 2400 digital source meter system to test the driving voltage, current efficiency, and service life of the OLEDs in the above examples. Among them, the optoelectronic property test conditions: the current density is 10 mA / cm 2 ; Life test: The current density is 50 mA / cm 2 , and record the time (in hours) when the device brightness drops to 95% of the original brightness. The results are as follows:

[0184]

[0185] The above results show that the organic electroluminescent device made of the organic electroluminescent compound provided by the present invention has the characteristics of high current efficiency and long service life compared with conventional materials; at the same time, by comparing Application Examples 1, 2, 7-15, it can also be found that the present invention can further improve the current efficiency and service life of the made organic electroluminescent device by using arylamine compounds and triazine compounds with specific structures in combination with the above organic electroluminescent compounds.

[0186] The applicant declares that the present invention uses the above embodiments to illustrate the organic electroluminescent compound and its application of the present invention, but the present invention is not limited to the above embodiments, that is, it does not mean that the present invention must rely on the above embodiments to be implemented. Those skilled in the art should understand that any improvement to the present invention, the equivalent replacement of each raw material of the product of the present invention, the addition of auxiliary components, the selection of specific methods, etc., all fall within the protection scope and the disclosure scope of the present invention.

[0187] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solutions of the present invention, and these simple modifications all fall within the protection scope of the present invention.

[0188] In addition, it should be noted that, in the various specific technical features described in the above specific embodiments, they can be combined in any suitable manner without conflict. In order to avoid unnecessary repetition, the present invention will not separately describe various possible combination manners.

Claims

1. An organic electroluminescent compound, characterized in that, The structure of the organic electroluminescent compound is shown in Formula I: wherein L, L 1 , L 2 are independently selected from any one of a single bond, a substituted or unsubstituted C6-C30 arylene group, and a substituted or unsubstituted C3-C30 heteroarylene group; Ar 1 selected from any one of substituted or unsubstituted C6-C60 aryl and substituted or unsubstituted C3-C60 heteroaryl; Ar 2 selected from any one of methyl, substituted or unsubstituted C6-C60 aryl; The substituted substituent group is selected from any one of deuterium, halogen, methyl or phenyl.

2. The organic electroluminescent compound according to claim 1, wherein The organic electroluminescent compound has a structural general formula shown in any one of the following:

3. The organic electroluminescent compound according to claim 2, wherein The organic electroluminescent compound has a structural general formula shown in any one of the following: Wherein, L, L 1 , L 2 , Ar 1 , Ar 2 The scope of protection is the same as that of claim 1.

4. The organic electroluminescent compound according to claim 1, wherein L, L 1 , L 2 are independently selected from a single bond or a phenylene group.

5. The organic electroluminescent compound according to claim 1, L 2 is selected from dibenzofurandiylidene groups.

6. The organic electroluminescent compound according to claim 1, wherein Ar 1 selected from any one of the following substituted or unsubstituted groups: phenyl, biphenyl, terphenyl, naphthyl, phenyl-substituted naphthyl, naphthyl-substituted phenyl, dibenzofuranyl, dibenzothiophenyl, phenyl-substituted carbazolyl, 9,9'-dimethylfluorenyl, 9,9'-diphenylfluorenyl or spirobifluorenyl.

7. The organic electroluminescent compound according to claim 1, characterized in that, Ar 2 selected from methyl or any one of the following substituted or unsubstituted groups: phenyl, biphenyl, naphthyl, phenyl-substituted naphthyl, naphthyl-substituted phenyl, dibenzofuranyl or 9,9'-dimethylfluorenyl.

8. The organic electroluminescent compound according to claim 1, characterized in that, The organic electroluminescent compound is selected from any one of the following structures:

9. Use of the organic electroluminescent compound according to any one of claims 1-8 in the preparation of an organic light emitting diode.

10. An organic light-emitting diode, characterized in that, The organic light emitting diode includes a first electrode, a second electrode, and an organic layer between the first electrode and the second electrode, and the material of the organic layer includes at least one organic electroluminescent compound according to any one of claims 1-8.

11. The organic light emitting diode according to claim 10, wherein The organic layer includes a hole transport layer, a light emitting auxiliary layer, a light emitting layer, a hole blocking layer, and an electron transport layer which are sequentially stacked.

12. The organic light-emitting diode according to claim 11, wherein The hole transport layer contains the organic electroluminescent compound according to any one of claims 1-8.

13. The organic light emitting diode according to claim 11, wherein The light emitting auxiliary layer contains the organic electroluminescent compound according to any one of claims 1-8.

14. The organic light emitting diode according to claim 11, characterized in that, The light emitting layer contains a host material and a guest material, the guest material is an Ir-containing complex, and the host material contains an aromatic amine compound.

15. The organic light emitting diode according to claim 14, characterized in that, The host material further contains a triazine compound.

16. The organic light-emitting diode according to claim 14, wherein The structure of the aromatic amine compound is shown in Formula P: Among them, L 6 , L 7 , L 8 is independently selected from any one of a single bond, a substituted or unsubstituted C6-C30 arylene group, and a substituted or unsubstituted C3-C30 heteroarylene group; Ar 6 、Ar 7 、Ar 8 independently selected from any one of hydrogen, deuterium, halogen, cyano, substituted or unsubstituted C1-C30 alkyl, substituted or unsubstituted C3-C30 cycloalkyl, substituted or unsubstituted C6-C60 aryl, and substituted or unsubstituted C3-C60 heteroaryl; The substituted substituent group is selected from any one of deuterium, halogen, cyano, methyl, tert-butyl, phenyl, pyridyl, naphthyl or biphenyl.

17. The organic light emitting diode according to claim 15, wherein The structure of the triazine compound is shown in Formula N: wherein L 3 and L 4 and L 5 are independently selected from any one of a single bond, a substituted or unsubstituted C6-C30 arylene group, and a substituted or unsubstituted C3-C30 heteroarylene group; Ar 3 、Ar 4 、Ar 5 independently selected from any one of hydrogen, deuterium, halogen, cyano, substituted or unsubstituted C1-C30 alkyl, substituted or unsubstituted C3-C30 cycloalkyl, substituted or unsubstituted C6-C60 aryl, and substituted or unsubstituted C3-C60 heteroaryl; The substituted substituent group is selected from any one of deuterium, halogen, cyano, methyl, tert-butyl, phenyl, pyridyl, naphthyl or biphenyl.

18. The organic light emitting diode according to claim 16, wherein, L 6 、L 7 、L 8 are independently selected from a single bond or a phenylene group.

19. The organic light-emitting diode according to claim 16, wherein Ar 6 、Ar 7 、Ar 8 independently selected from hydrogen, deuterium, halogen, and substituted or unsubstituted groups such as any one of phenyl, biphenyl, terphenyl, naphthyl, naphthyl-substituted phenyl, phenyl-substituted naphthyl, dibenzofuranyl, dibenzothiophenyl, 9,9'-dimethylfluorenyl, 9,9'-diphenylfluorenyl, spirobifluorenyl, carbazolyl or pyridyl.

20. The organic light-emitting diode according to claim 17, characterized in that, L 3 、L 4 、L 5 are independently selected from a single bond or a phenylene group.

21. The organic light emitting diode according to claim 17, wherein Ar 3 、Ar 4 、Ar 5 independently selected from hydrogen, deuterium, halogen, and a substituted or unsubstituted group selected from any one of the following: phenyl, biphenyl, terphenyl, naphthyl, naphthyl-substituted phenyl, phenyl-substituted naphthyl, dibenzofuranyl, dibenzothiophenyl, 9,9'-dimethylfluorenyl, 9,9'-diphenylfluorenyl, spirobifluorenyl, carbazolyl, or pyridyl.

22. The organic light-emitting diode according to claim 16, wherein, Ar 6 、 Ar 7 、 Ar 8 At least one of them is selected from a substituted or unsubstituted carbazolyl group.

23. The organic light-emitting diode according to claim 16, wherein, Ar 6 、 Ar 7 、 Ar 8 Only one of them is selected from a substituted or unsubstituted carbazolyl group.

24. The organic light emitting diode according to claim 17, wherein Ar 3 、Ar 4 、Ar 5 At least one of them is selected from dibenzofuranyl groups.

25. The organic light-emitting diode according to claim 17, wherein Ar 3 、 Ar 4 、 Ar 5 Only one of them is selected from dibenzofuranyl.

26. The organic light-emitting diode according to claim 17, wherein Ar 3 、Ar 4 、Ar 5 At least one of them is selected from 9,9'-dimethylfluorenyl or 9,9'-diphenylfluorenyl or spirobifluorenyl.

27. The organic light emitting diode according to claim 17, wherein Ar 3 、Ar 4 、Ar 5 Only one of them is selected from 9,9'-dimethylfluorenyl or 9,9'-diphenylfluorenyl or spirobifluorenyl.

28. The organic light emitting diode according to claim 14, wherein The aromatic amine compound is selected from any one of the following structures:

29. The organic light emitting diode according to claim 15, wherein The triazine compound is selected from any one of the following structures:

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