A triphenylenoxazole compound and application thereof

Abstract

The application provides a triphenylenoxazole compound and application thereof, and the structure of the triphenylenoxazole compound is shown as formula I: wherein L, L 1 , L 2 , L 3 , L 4 , L 5 , L 6 , L 7 , L 8 are independently selected from a single bond, a substituted or unsubstituted C6-C30 arylene group. The triphenylenoxazole compound provided by the application is applied to an organic electroluminescent device, and can effectively improve the current efficiency and service life of the device.

Description

Technical Field

[0001] This invention belongs to the field of organic electroluminescent materials, specifically relating to a tribenzoxazole compound and its applications, and more particularly to a tribenzoxazole compound with high current efficiency and its applications. Background Technology

[0002] Recently, with the increase in display size, there has been growing interest in flat panel display elements that occupy less space. In this field, organic light-emitting diode (OLED) displays, including OLEDs as flat panel display elements, have developed rapidly. OLEDs emit light by annihilating holes and electrons from hole injection electrodes (anodes) and electron injection electrodes (cathodes) into an emitter layer between the anode and cathode, creating electron-hole pairs. Such OLEDs can be formed on flexible transparent substrates such as plastics, operate at low voltages, consume relatively low power, and have good color reproduction.

[0003] In 1987, Tang et al. of Eastman Kodak first developed OLEDs, a small-molecule green organic electroluminescent device consisting of a light-emitting layer and an electron transport layer. Since then, research on organic electroluminescent devices has rapidly progressed and they have been successfully commercialized.

[0004] CN108290875A discloses a new compound capable of improving the luminous efficiency, stability, and lifetime of electronic devices, as well as organic electronic components and electronic devices utilizing this compound. This compound improves the luminous efficiency, driving voltage, and heat resistance of electronic devices, and also enhances color purity and lifetime. The structure of this compound is as follows:

[0005]

[0006] As the requirements for organic light-emitting diodes (OLEDs) become increasingly stringent, the need for novel OLED materials is becoming more urgent. Furthermore, for displays requiring long-term use and high resolution, OLEDs with higher luminous efficiency and / or longer lifespans are needed. Therefore, providing a high-efficiency, long-life material for OLEDs has become a pressing issue. Summary of the Invention

[0007] To address the shortcomings of existing technologies, the present invention aims to provide a tribenzoxazole compound and its applications, particularly a tribenzoxazole compound with high current efficiency and its applications. The tribenzoxazole compound provided by the present invention, when applied to organic electroluminescent devices, can effectively improve the current efficiency and lifespan of the devices.

[0008] To achieve this objective, the present invention adopts the following technical solution:

[0009] In a first aspect, the present invention provides a triphenylenebenzoxazole compound, the structure of which is shown in Formula I:

[0010]

[0011] Among them, L, L 1 L 2 L 3 L 4 L 5 L 6 L 7 L 8 Aryl groups independently selected from single-bonded, substituted, or unsubstituted C6-C30 groups.

[0012] Ar, R 1 R 2 R 3 R 4 R 5 R 6 R 7 R 8 Independently selected from hydrogen, deuterium, halogen, cyano, substituted or unsubstituted C1-C30 alkyl, substituted or unsubstituted C1-C30 alkyl with one or more non-adjacent methylene groups independently substituted by O or S atoms, substituted or unsubstituted C2-C30 alkenyl, substituted or unsubstituted C2-C30 alkenyl with one or more non-adjacent methylene groups independently substituted by O or S atoms, substituted or unsubstituted C7-C60 aralkyl, substituted or unsubstituted C6-C60 aryl, substituted or Any one of the following: unsubstituted C3-C60 heteroaryl, substituted or unsubstituted C4-C60 heteroarylalkyl, substituted or unsubstituted C3-C30 cycloalkyl, substituted or unsubstituted C3-C30 heterocycloalkyl, substituted or unsubstituted C3-C30 cycloalkenyl, substituted or unsubstituted C1-C30 alkylamino, substituted or unsubstituted C6-C60 arylamino, substituted or unsubstituted C3-C60 heteroarylamino, and substituted or unsubstituted C6-C60 arylC3-C60 heteroarylamino.

[0013] The substituent is selected from any one of deuterium, halogen, cyano, unsubstituted or R'-substituted C1-C6 alkyl, unsubstituted or R'-substituted C6-C12 aryl, and unsubstituted or R'-substituted C2-C20 heteroaryl.

[0014] R' is selected from any one of deuterium, halogen, cyano, deuterated methyl or halogenated methyl.

[0015] The application of the aforementioned tribenzoxazole compounds with specific structures in organic electroluminescent devices can effectively improve the current efficiency and lifespan of the devices.

[0016] Preferably, the Ar is an electron transport group;

[0017] Preferably, the Ar is selected from...

[0018] Z 1 Selected from N or CR Z1 Z 2 Selected from N or CR Z2 Z 3 Selected from N or CR Z3 Z 4 Selected from N or CR Z4 Z 5 Selected from N or CR Z5 .

[0019] R Z1 R Z2 R Z3 R Z4 R Z5 Independently selected from any one of hydrogen, deuterium, halogen, cyano, substituted or unsubstituted C1-C30 alkyl, substituted or unsubstituted C1-C30 alkyl with one or more non-adjacent methylene groups independently substituted by O or S atoms, substituted or unsubstituted C7-C60 aralkyl, substituted or unsubstituted C6-C60 aryl, substituted or unsubstituted C3-C60 heteroaryl, substituted or unsubstituted C4-C60 heteroaryl, substituted or unsubstituted C3-C30 cycloalkyl, substituted or unsubstituted C3-C30 heterocycloalkyl, substituted or unsubstituted C3-C30 cycloalkenyl, R Z1 R Z2 R Z3 R Z4 R Z5 Each exists independently or two adjacent rings are connected to form a ring C, wherein the ring C is selected from substituted or unsubstituted C6-C30 aromatic rings and substituted or unsubstituted C3-C30 heteroaromatic rings.

[0020] Preferably, the Ar is selected from... Z 2 Z 4 It has the same scope of limitation as described above.

[0021] Preferably, the Ar is selected from... Z 2 Z 3 Z 4 It has the same scope of limitation as described above.

[0022] Preferably, the Ar is selected from... Z 2 Z 4 Z 5 It has the same scope of limitation as described above.

[0023] Preferably, the ring C is a benzene ring.

[0024] Preferably, the Ar is selected from... Where R Z2 It has the same scope of limitation as described above.

[0025] Preferably, the Ar is selected from... Where R Z1 It has the same scope of limitation as described above.

[0026] Preferably, the R Z1 R Z2 R Z3 R Z4 R Z5 Independently selected from hydrogen, deuterium, halogen, cyano, or any of the following groups, substituted or unsubstituted: phenyl, biphenyl, terphenyl, naphthyl, phenanthryl, anthracene, phenyl-substituted naphthyl, naphthyl-substituted phenyl, pyridyl, cyclopyridyl, dibenzofuranyl, dibenzothiopheneyl, carbazoleyl (selected from...) ), dimethylfluorenyl (9'9-dimethylfluorenyl, selected from ), diphenylfluorenyl (9'9-diphenylfluorenyl, selected from ), spirodifluorenyl, dibenzofuran-substituted phenyl, dibenzothiophene-substituted phenyl, dimethylfluorenyl-substituted phenyl, benzocarbazolyl, benzonaphthofuranyl, benzonaphthothiophene.

[0027] Preferably, the Ar is selected from any one of the following groups:

[0028]

[0029]

[0030]

[0031]

[0032] Preferably, the Ar is a hole-transporting group.

[0033] Preferably, the Ar is selected from...

[0034] Among them, Ar 1 Ar 2It is independently selected from any one of hydrogen, deuterium, halogen, cyano, substituted or unsubstituted C1-C30 alkyl, substituted or unsubstituted C1-C30 alkyl with one or more non-adjacent methylene groups independently substituted by O or S atoms, substituted or unsubstituted C7-C60 aralkyl, substituted or unsubstituted C6-C60 aryl, substituted or unsubstituted C3-C60 heteroaryl, substituted or unsubstituted C4-C60 heteroaryl, substituted or unsubstituted C3-C30 cycloalkyl, substituted or unsubstituted C3-C30 heterocycloalkyl, and substituted or unsubstituted C3-C30 cycloalkenyl.

[0035] L P1 L P2 Aryl groups independently selected from single-bonded, substituted, or unsubstituted C6-C30 groups.

[0036] Preferably, the Ar 1 Ar 2 The group is independently selected from any one of the following groups: hydrogen, deuterium, halogen, cyano, substituted or unsubstituted: phenyl, biphenyl, terphenyl, naphthyl, phenanthryl, anthracene, phenyl-substituted naphthyl, naphthyl-substituted phenyl, pyridyl, cyclopyridyl, dibenzofuranyl, dibenzothiophene, carbazolyl, dimethylfluorenyl, diphenylfluorenyl, spirodifluorenyl, benzocarbazolyl, benzonaphthofuranyl, benzonaphthothiophene.

[0037] Preferably, the Ar is selected from any one of the following groups:

[0038]

[0039]

[0040] Preferably, the L 1 L 2 L 3 L 4 L 5 L 6 L 7 L 8 Selected from hydrogen, R 1 R 2 R 3 R 4 R 5 R 6 R 7 R 8 Selected from hydrogen.

[0041] Preferably, the L is selected from phenylene.

[0042] Preferably, the L P1 Selected from single bonds or phenylene.

[0043] Preferably, the L P2 Selected from single bonds or phenylene.

[0044] Preferably, the tribenzoxazole compound is an electron transport compound, and the electron transport compound is selected from any one of the following compounds N-1 to N-64:

[0045]

[0046]

[0047]

[0048]

[0049]

[0050] Preferably, the tribenzoxazole compound is a hole-transporting compound, and the hole-transporting compound is selected from any one of the following compounds P-1 to P-84:

[0051]

[0052]

[0053]

[0054]

[0055]

[0056]

[0057] The above-mentioned tribenzoxazole compounds can be exemplarily prepared by a reaction comprising the following steps:

[0058] Ar selected The synthesis route is as follows:

[0059]

[0060] The raw materials first undergo a nitration reaction, then nitro reduction and cyclization are carried out using DDQ reagent, and finally the product is obtained by suzuki coupling.

[0061] Ar selected The synthesis route is as follows:

[0062]

[0063] The raw material is first converted from bromine to boric acid in the presence of a palladium catalyst, and then Suzuki coupling is performed to obtain the product.

[0064] Among them, L, L 1 L 2 L 3 L 4 L 5 L 6 L 7 L 8 Ar, R 1 R 2 R 3 R 4 R 5 R 6 R 7 R 8 It has the same scope of limitation as described above.

[0065] In a second aspect, the present invention provides a composition comprising the tribenzoxazole compound as described above.

[0066] Preferably, the composition comprises any one of the electron transport compounds and any one of the hole transport compounds as described above.

[0067] Preferably, the mass ratio of the electron transport compound to the hole transport compound is 1:9 to 9:1, wherein the mass ratio of the electron transport compound can be 1, 2, 3, 4, 5, 6, 7, 8 or 9, etc., and the mass ratio of the hole transport compound can be 1, 2, 3, 4, 5, 6, 7, 8 or 9, etc., but is not limited to the values ​​listed above. Other unlisted values ​​within the above range are also applicable.

[0068] Preferably, the mass ratio of the electron transport compound to the hole transport compound is 2:8-8:2.

[0069] Preferably, the mass ratio of the electron transport compound to the hole transport compound is 3:7-7:3.

[0070] Preferably, the mass ratio of the electron transport compound to the hole transport compound is 4:6 to 6:4.

[0071] Thirdly, the present invention provides the use of the triphenyloxazole compounds or the compositions described above in the preparation of organic light-emitting diodes.

[0072] Fourthly, the present invention provides an organic light-emitting diode, the organic light-emitting device comprising a first electrode, a second electrode, and an organic layer between the first electrode and the second electrode, the organic layer comprising at least one tribenzoxazole compound as described above and / or at least one composition as described above.

[0073] Preferably, the organic layer includes any one or a combination of at least two of the following: a hole injection layer, a first hole transport layer, a second hole transport layer, an electron blocking layer, a light emitting layer, a hole blocking layer, an electron transport layer, or an electron injection layer. For example, a combination of a hole injection layer and a first hole transport layer, a combination of a first hole transport layer and a second hole transport layer, or a combination of an electron transport layer and an electron injection layer, etc., but not limited to the combinations listed above. Other combinations not listed within the above range are also applicable.

[0074] Preferably, the hole-blocking layer comprises at least one tribenzoxazole compound as described above.

[0075] Preferably, the electron transport layer comprises at least one tribenzoxazole compound as described above.

[0076] Preferably, the light-emitting layer contains at least one triphenyloxazole compound as described above.

[0077] Preferably, the light-emitting layer comprises the composition described above.

[0078] Fifthly, the present invention also provides an organic electroluminescent device, the organic electroluminescent device comprising the organic electroluminescent diode as described above.

[0079] Compared with the prior art, the present invention has the following beneficial effects:

[0080] This invention provides a tribenzoxazole compound with a specific structure, which, when applied to organic electroluminescent devices, can effectively improve the current efficiency and lifespan of the devices. Attached Figure Description

[0081] Figure 1 This is a schematic diagram of the organic electroluminescent device in Application Examples 1-3, where 1-substrate, 2-anode, 3-hole injection layer, 4-hole transport layer, 5-light-emitting layer, 6-electron buffer layer, 7-electron transport layer, 8-electron injection layer, and 9-cathode. Detailed Implementation

[0082] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention in any way.

[0083] As used in this invention, the term "organic electroluminescent compound" means a compound that can be used in an organic electroluminescent device and can be included, as needed, in any layer constituting the organic electroluminescent device.

[0084] As used in this invention, the term "organic electroluminescent material" refers to a material that can be used in an organic electroluminescent element and may contain at least one compound. If desired, the organic electroluminescent material may be contained in any layer constituting the organic electroluminescent element. For example, the organic electroluminescent material may be a hole injection material, a hole transport material, an electron blocking material, a light-emitting auxiliary material, a light-emitting layer material (comprising a host material and a dopant material), an electron buffer material, a hole blocking material, an electron transport material, an electron injection material, etc.

[0085] The organic electroluminescent material disclosed herein may contain at least one compound represented by Formula 1. While not limited thereto, a compound having Formula 1 may be contained in the luminescent layer. In this case, the compound having Formula 1 may be contained as a host. If desired, the host material may contain two or more compounds of Formula 1. Furthermore, a compound having Formula 1 may be contained in the electron transport region, and / or a compound having Formula 1 may be contained in the electron buffer layer, and is not limited thereto.

[0086] The following describes each layer of an organic electroluminescent element comprising a compound of Formula 1 of the present invention.

[0087] substrate

[0088] Organic EL elements are typically fabricated on a light-transmitting substrate. This light-transmitting substrate is used to support the organic EL element, and its transmittance of light in the visible region with wavelengths of 400-700 nm is preferably 50% or more, and a smooth substrate is even more preferred.

[0089] Examples of such light-transmitting substrates include glass plates and synthetic resin plates. Examples of glass plates include those made from soda-lime glass, barium / strontium-containing glass, lead glass, aluminosilicate glass, borosilicate glass, barium borosilicate glass, and quartz. Examples of synthetic resin plates include those made from polycarbonate resin, acrylic resin, polyethylene terephthalate resin, polyether sulfide resin, and polysulfone resin.

[0090] anode

[0091] The anode serves to inject holes into the hole transport layer or the light-emitting layer, and a work function of 4 eV or higher (preferably 4.45 eV or higher) is effective. Specific examples of anode materials include carbon, aluminum, vanadium, iron, cobalt, nickel, tungsten, silver, gold, platinum, palladium, 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.

[0092] cathode

[0093] As the cathode, metals, alloys, conductive compounds, and mixtures thereof with low work functions (less than 4 eV) can be used as the cathode electrode material. Specific examples of such electrode materials include magnesium, calcium, tin, lead, titanium, yttrium, lithium, ruthenium, manganese, aluminum, lithium fluoride, and their alloys; there are no particular limitations on these materials. Representative examples of such alloys include magnesium / silver, magnesium / indium, and lithium / aluminum; there are no particular limitations on these alloys. The alloy ratio is controlled by the temperature, atmosphere, and vacuum level of the vapor deposition source, and an appropriate ratio is selected. The anode and cathode can also be formed by two or more layers as needed.

[0094] Emissive layer

[0095] The luminescent layer combines carrier injection, carrier transport, and light emission functions. The luminescent layer materials include host materials and guest materials. Guest materials include phosphorescent guest materials, fluorescent guest materials, and TADF guest materials, among others.

[0096] Hole injection layer / hole transport layer

[0097] A hole injection layer / hole transport layer is a layer that facilitates the injection of holes into the light-emitting layer and the transport of holes to the light-emitting region. It has a high hole mobility and an ionization energy typically below 5.7 eV. 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, high when an electric field is applied at 10... 4 -10 6 When the electric field is 10 V / cm -4 cm 2 / V·second or higher. Examples of materials known as hole transport layer materials include bis(N-(1-naphthyl-n-phenyl))benzidine (α-NPD), N,N'-bis(naphthyl-1-yl)-N,N'-biphenylbenzidine (NPB), or N,N'-biphenyl-N,N'-bis(3-methylphenyl)-1,1'-biphenyl-4,4'-diamine (TPD), etc.

[0098] Electron injection layer / electron transport layer

[0099] The electron injection layer / electron transport layer is a layer that facilitates the injection of electrons into the light-emitting layer and the transport of electrons to the light-emitting region, exhibiting high electron mobility. The adhesion improvement layer is an electron injection layer containing a material that adheres particularly well to the cathode.

[0100] Materials used in the electron injection layer include, specifically, LiF, Liq, Li2O, BaO, NaCl, CsF, etc., without any particular limitation.

[0101] The functionality of an OLED can be achieved by combining the various layers described above, or by omitting some layers entirely. It may also include other layers not explicitly described. Within each layer, optimal performance can be achieved using a single material or a mixture of multiple materials. Any functional layer may include several sublayers. For example, a light-emitting layer may have two different light-emitting materials to achieve the desired emission spectrum.

[0102] To form each layer of the organic electroluminescent device of this disclosure, dry film-forming methods such as vacuum evaporation, sputtering, plasma, and ion plating can be used, or wet film-forming methods such as inkjet printing, nozzle printing, slot coating, spin coating, dip coating, and flow coating can be used. The organic electroluminescent compounds of this disclosure can be formed into films by co-evaporation or mixture evaporation.

[0103] As used in this invention, the term "halogen" may include fluorine, chlorine, bromine or iodine, preferably fluorine.

[0104] As used in this invention, the term "C1-C30 alkyl" refers to a monovalent substituent derived from a straight-chain or branched saturated hydrocarbon having 1 to 30 carbon atoms, examples of which include, but are not limited to, methyl, ethyl, propyl, isobutyl, sec-butyl, tert-butyl, pentyl, isopentyl, and hexyl.

[0105] As used in this invention, the term "C3-C30 cycloalkyl" refers to a monocyclic or polycyclic hydrocarbon derived from a main chain of 1 to 30 carbon atoms, including cyclopropyl, cyclobutyl, adamantyl, etc.

[0106] As used in this invention, the term "C3-C30 heterocyclic alkyl" refers to a monocyclic or polycyclic hydrocarbon having 1 to 30 carbon atoms in its main ring chain, wherein at least one carbon atom is replaced by a heteroatom selected from at least one of O, S, N, Si, and P, preferably O, S, or N. Additionally, the heterocyclic alkyl may optionally be substituted.

[0107] As used herein, the term "C2-C30 alkenyl" refers to and includes both straight-chain and branched alkenyl groups. An alkenyl group is essentially an alkyl group comprising at least one carbon-carbon double bond in an alkyl chain. A cycloalkenyl group is a cycloalkyl group comprising at least one carbon-carbon double bond in a cycloalkyl ring.

[0108] As used in this invention, the term "C1-C30 alkylamino" refers to

[0109] As used in this invention, the term "C6-C60 arylamino" refers to

[0110] As used in this invention, the term "C3-C60 heteroarylamino" refers to

[0111] As used in this invention, the term "C6-C60 arylC3-C60 heteroarylamino" refers to...

[0112] In this invention, aryl and arylene groups include monocyclic, polycyclic, or fused-ring aryl groups, and the rings may be interrupted by short non-aromatic units, and may contain spiro structures, including but not limited to phenyl, biphenyl, terphenyl, naphthyl, phenanthryl, anthraceneyl, fluorenyl, spirodifluorenyl, etc.

[0113] In this invention, heteroaryl and hypoaryl groups include monocyclic, polycyclic or fused-ring heteroaryl groups, and the rings can be interrupted by short non-aromatic units. The heteroatoms include nitrogen, oxygen and sulfur. Including but not limited to furanyl, phenylthio, pyrroloyl, imidazolyl, pyrazolyl, thiazolyl, thiadiazolyl, isothiazolyl, isoxazolyl, oxazolyl, oxadiazolyl, triazinyl, tetraazinyl, triazolyl, tetraazolyl, furazolyl, pyridinyl, pyrazinyl, pyrimidinyl, pyridazinyl, benzofuranyl, benzothiopheneyl, isobenzofuranyl, dibenzofuranyl, dibenzothiopheneyl, benzimidazolyl, benzothiazolyl, benziisothiazolyl, benziisooxazolyl, benzooxazolyl, isoindolyl, indolyl, inzolyl, benzothiadiazolyl, quinolinyl, isoquinolinyl, cenolinyl, quinazolinyl, quinoxolinyl, carbazole, phenoxazinyl, phenthiazinyl, phenanthidyl, benzo-m-dioxacyclopentenyl, dihydroacridinyl, and their derivatives.

[0114] As used in this invention, the term "substituted" means that a hydrogen atom in a compound is replaced by another substituent. This position is not limited to a specific position, as long as the hydrogen at that position can be replaced by a substituent. When two or more substituents are present, the two or more substituents can be the same or different.

[0115] As used in this invention, unless otherwise stated, a hydrogen atom includes protium, deuterium, and tritium.

[0116] In this invention, the definition of a group specifies a range of carbon atoms, and the number of carbon atoms is any integer within the defined range, such as C6-C60 aryl. The number of carbon atoms representing an aryl group 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.

[0117] In this invention, This represents the substitution site of the substituent.

[0118] Synthesis of intermediates

[0119]

[0120] 1. Synthesis of intermediate 1-1: Raw material 1 (CAS: 76885-34-2, 10 mmol) was added to glacial acetic acid (10 mL), and a solution of fuming nitric acid (20 mmol) in glacial acetic acid (5 mL) was added dropwise under ice bath. After the addition was complete, the mixture was stirred at 20 °C for 2 hours. 20 mL of ice water was added, and the mixture was filtered. The filter cake was washed until neutral and dried under reduced pressure to obtain intermediate 1-1 (2.75 g, yield 95%).

[0121] MS(APCI)m / z[M+H] + Theoretical value: 290.07; Measured value: 290.21.

[0122] 2. Synthesis of intermediate 1-2: Intermediate 1-1 (10 mmol) was added to a mixed solution of ethyl acetate and 1,2-dichlorobenzene. Pd / C (10% Pd) was added under nitrogen protection. The reaction system was stirred at 20°C for 2 hours under 1 atm hydrogen pressure. The reaction solution was filtered with diatomaceous earth and the organic solvent was removed by vacuum distillation to obtain intermediate 1-2 (2.39 g, yield 92%).

[0123] MS(APCI)m / z[M+H] + Theoretical value: 260.10; Measured value: 261.27.

[0124] 3. Synthesis of intermediates 1-3: Intermediate 1-2 (12 mmol) and starting material 2 (10 mmol) were added separately to anhydrous ethanol (20 mL), stirred at 20 °C for 1 hour, DDQ (10 mmol) was added, and stirred at room temperature for 2 hours. The reaction solution was filtered, and the filtered product was washed with dichloromethane. The organic phases were combined, washed with saturated sodium bicarbonate, dried over anhydrous sodium sulfate, and the organic solvent was removed by vacuum distillation. The crude product was separated by column chromatography (dichloromethane:n-hexane = 1:20, v / v) to give intermediate 1-3 (3.64 g, yield 86%).

[0125] MS(APCI)m / z[M+H] + Theoretical value: 424.03; Measured value: 424.09.

[0126] 4. Synthesis of Intermediate 1: Intermediates 1-3 (10 mmol), pinacol diborate (12 mmol), sodium acetate (20 mmol), tris(dibenzylacetone)dipalladium (0.5 mmol), and 2-biscyclohexylphosphine-2',6'-dimethoxybiphenyl (1.5 mmol) were added to 1,4-dioxane (20 mL), and the mixture was purged with nitrogen three times. Under nitrogen protection, the mixture was heated to 100 °C. After the reaction was completed, the mixture was quenched with water, extracted with dichloromethane, and the organic solvent was removed by rotary evaporation. The crude product was separated by column chromatography (ethyl acetate:n-hexane = 1:50, v / v) to give intermediate 1 (3.03 g, yield 78%).

[0127] MS(APCI)m / z[M+H] + Theoretical value: 390.12; Measured value: 390.02.

[0128] Using intermediate 1-2 as the raw material, and by changing other raw materials, intermediates 2-3 and 3-3 are obtained respectively, thus obtaining intermediate 2 and intermediate 3:

[0129]

[0130]

[0131] Example 1

[0132] This embodiment provides a tribenzoxazole compound N-2, the synthesis reaction formula of which is as follows:

[0133]

[0134] Synthesis of N-2: Intermediate 1 (10 mmol), starting material 5 (10 mmol), sodium bicarbonate (23 mmol), tetrakis(triphenylphosphine)palladium (0.5 mmol), and dichlorodi-tert-butyl-(4-dimethylaminophenyl)phosphine-palladium (0.5 mmol) were added to toluene (25 mL) and ethanol (7 mL), along with water (7 mL). The mixture was purged three times with nitrogen. Under nitrogen protection, the mixture was heated to 80 °C and reacted for 8 hours. After the reaction, the mixture was extracted with ethyl acetate. The extract was then dried with magnesium sulfate, filtered, and evaporated to dryness. The crude product was purified by chromatography (ethyl acetate:n-hexane = 1:10, v / v) to give N-2 (4.89 g, yield 75%).

[0135] MS(APCI)m / z[M+H] + Theoretical value: 653.23; Measured value: 653.34.

[0136] Examples 2-8

[0137] Referring to the preparation method in Example 1, different products were obtained by changing different raw materials, as detailed below:

[0138]

[0139]

[0140]

[0141] Example 9

[0142] This embodiment provides a tribenzoxazole compound P-1, the synthesis reaction formula of which is as follows:

[0143]

[0144] Synthesis of P-1: Intermediate 1-3 (10 mmol), starting material 6 (10 mmol), Pd2(dba)3 (0.5 mmol), 50% tri-tert-butylphosphine solution (1 mmol), NaO t Bu (22 mmol) and toluene (30 mL) were mixed and refluxed with stirring for 5 hours. After the reaction was completed, the mixture was cooled to room temperature, and the organic solvent was removed by vacuum distillation. The crude product was purified by chromatography (ethyl acetate: hexane = 1:10 v / v) to give P-1 (4.33 g, yield 72%).

[0145] MS(APCI)m / z[M+H] + Theoretical value: 603.20; Measured value: 603.32.

[0146] Examples 10-13

[0147] Referring to the preparation method of Example 9, different products were obtained by changing different raw materials, as detailed below:

[0148]

[0149]

[0150] Application Example 1-13 and Comparative Application Example 1

[0151] The tribenzoxazole compounds provided in the above embodiments are used to prepare organic electroluminescent devices, which have the following layer structure: substrate (indium tin oxide (ITO) as the anode-coated glass substrate) / hole injection layer (HIL) / hole transport layer (HTL) / light emission layer (EML) / electron buffer layer (optional) / electron transport layer (ETL) / electron injection layer (EIL), and finally a cathode. The structural schematic diagrams in Examples 1-3 are shown below. Figure 1As shown, 1 is the substrate, 2 is the anode, 3 is the hole injection layer, 4 is the hole transport layer, 5 is the light-emitting layer, 6 is the electron buffer layer, 7 is the electron transport layer, 8 is the electron injection layer, and 9 is the cathode.

[0152] The materials required to manufacture OLEDs are as follows:

[0153]

[0154] The preparation method is as follows:

[0155] (1) Substrate cleaning: The glass substrate coated with transparent ITO is ultrasonically treated in an aqueous cleaning agent (the composition and concentration of the aqueous cleaning agent are: ethylene glycol solvent ≤10wt%, triethanolamine ≤1wt%), 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 removed, and then cleaned with ultraviolet light and ozone.

[0156] (2) Evaporation of organic light-emitting functional layer:

[0157] The glass substrate with the anode layer was placed in a vacuum chamber and evacuated to a vacuum level of 1×10⁻⁶. -6 Up to 2×10 -4 Pa, a mixture of HATCN and HT is vacuum-deposited on the above-mentioned anodic layer film, wherein the mass ratio of HATCN to HT is 3:97, as a hole injection layer (HIL), and the deposition thickness is 10 nm.

[0158] A hole transport layer (HTL, material HT) is deposited on the hole injection layer, with a film thickness of 80 nm.

[0159] A light-emitting layer (EML) is deposited on the hole transport layer. The specific preparation method is as follows: the light-emitting host material (selected from the compounds provided in the examples and CBP) and the guest material (piq)2Ir(acac) are vacuum deposited by co-evaporation, and the total film thickness is 30nm.

[0160] (Optional) An electron buffer layer (materials N-2, N-39 and N-62) is deposited on the light-emitting layer, with a total deposition thickness of 10 nm;

[0161] An electron transport layer (ETL) is deposited on the light-emitting layer (or an electron buffer layer if present). The specific preparation method is as follows: BCP and LiQ are vacuum deposited by co-evaporation, and the total film thickness is 30 nm.

[0162] An electron injection layer (EIL, material LiQ) was vacuum-deposited on the electron transport layer, with a total film thickness of 1 nm.

[0163] Al was deposited on the electron injection layer, with a total film thickness of 90 nm.

[0164] The material parameters for each layer are as follows:

[0165]

[0166]

[0167]

[0168] Performance testing:

[0169] The organic electroluminescent devices provided in Application Examples 1-13 and Comparative Application Example 1 were tested using a PR650 spectral scanning luminance meter and a Keithley K 2400 digital source meter system simultaneously. The photoelectric properties were tested under the following conditions: a current density of 10 mA / cm². 2 The life test conditions were a current density of 10 mA / cm². 2 The recording time (in hours) when the device brightness dropped to 96% of its original brightness is as follows:

[0170]

[0171] The above results demonstrate that the use of the compounds provided by this invention to prepare organic electroluminescent devices can significantly improve the current efficiency and lifespan of the products.

[0172] The applicant declares that this invention illustrates the tribenzoxazole compounds and their applications through the above embodiments, but the invention is not limited to the above embodiments, that is, it does not mean that the invention must rely on the above embodiments to be implemented. Those skilled in the art should understand that any improvements to this invention, equivalent substitutions of the raw materials in the product of this invention, addition of auxiliary components, and selection of specific methods, etc., all fall within the protection scope and disclosure scope of this invention.

[0173] 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 solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.

[0174] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not describe the various possible combinations separately.

Claims

1. A tribenzoxazole compound, characterized in that, The structure of the tribenzoxazole compounds is shown in Formula I: ； Where L is selected from phenylene; L 1 L 2 L 3 L 4 L 5 L 6 L 7 L 8 Independently selected from single bonds; Ar selected , , or ; Among them, Z 2 Selected from CR Z2 Z 4 Selected from CR Z4 ; R Z1 R Z2 R Z4 It is independently selected from unsubstituted phenyl, unsubstituted biphenyl, unsubstituted dibenzofuranyl or unsubstituted 9,9-dimethylfluorenyl; L P1 L P2 Independently selected from single bonds or phenylene; Ar 1 Ar 2 It is independently selected from unsubstituted phenyl, unsubstituted biphenyl, unsubstituted dibenzofuranyl, unsubstituted N-pyridylcarbazoyl or unsubstituted 9,9-dimethylfluorenyl; R 1 R 2 R 3 R 4 R 5 R 6 R 7 R 8 It is independently selected from hydrogen.

2. The tribenzoxazole compound according to claim 1, characterized in that, The Ar is selected from , or ; Among them, Z 2 Selected from CR Z2 Z 4 Selected from CR Z4 ; R Z1 R Z2 R Z4 It is independently selected from unsubstituted phenyl, unsubstituted biphenyl, unsubstituted dibenzofuranyl or unsubstituted 9,9-dimethylfluorenyl.

3. The tribenzoxazole compound according to claim 2, characterized in that, The Ar is selected from any one of the following groups: ； ； ； ； ； ； ； ； ； ； ； ； ； ； 。 4. The tribenzoxazole compound according to claim 1, characterized in that, The Ar is selected from ; Among them, L P1 L P2 Independently selected from single bonds or phenylene; Ar 1 Ar 2 It is independently selected from unsubstituted phenyl, unsubstituted biphenyl, unsubstituted dibenzofuranyl, unsubstituted N-pyridylcarbazoyl or unsubstituted 9,9-dimethylfluorenyl.

5. The tribenzoxazole compound according to claim 4, characterized in that, The Ar is selected from any one of the following groups: ； ； ； ； ； ； 。 6. The tribenzoxazole compound according to claim 1, characterized in that, The tribenzoxazole compounds are electron transport compounds, and the electron transport compounds are selected from any one of the following compounds: ； ； ； ； ； ； ； ； 。 7. The tribenzoxazole compound according to claim 1, characterized in that, The tribenzoxazole compounds are hole-transporting compounds, and the hole-transporting compounds are selected from any one of the following compounds: ； ； ； ； ； ； ； ； ； 。 8. A composition, characterized in that, The composition comprises any one of the tribenzoxazole compounds according to claims 1-7.

9. The composition according to claim 8, characterized in that, The composition comprises any one of the electron transport compounds of claim 6 and any one of the hole transport compounds of claim 7.

10. The composition according to claim 9, characterized in that, The mass ratio of the electron transport compound to the hole transport compound is 1:9-9:

1.

11. The composition according to claim 10, characterized in that, The mass ratio of the electron transport compound to the hole transport compound is 2:8-8:

2.

12. The composition according to claim 11, characterized in that, The mass ratio of the electron transport compound to the hole transport compound is 3:7-7:

3.

13. The composition according to claim 12, characterized in that, The mass ratio of the electron transport compound to the hole transport compound is 4:6 to 6:

4.

14. The use of any one of the tribenzoxazole compounds of claims 1-7 or any one of the compositions of claims 8-13 in the preparation of organic light-emitting diodes.

15. An organic light-emitting diode, characterized in that, The organic light-emitting diode comprises a first electrode, a second electrode, and an organic layer between the first electrode and the second electrode, wherein the organic layer comprises at least one tribenzoxazole compound as described in any one of claims 1-7 and / or at least one composition as described in any one of claims 8-13.

16. The organic light-emitting diode according to claim 15, characterized in that, The organic layer includes any one or a combination of at least two of the following: a hole injection layer, a first hole transport layer, a second hole transport layer, an electron blocking layer, a light-emitting layer, a hole blocking layer, an electron transport layer, or an electron injection layer.

17. The organic light-emitting diode according to claim 16, characterized in that, The hole-blocking layer comprises at least one tribenzoxazole compound as described in any one of claims 1-7.

18. The organic light-emitting diode according to claim 16, characterized in that, The electron transport layer comprises at least one tribenzoxazole compound as described in any one of claims 1-7.

19. The organic light-emitting diode according to claim 16, characterized in that, The luminescent layer comprises at least one tribenzoxazole compound as described in any one of claims 1-7.

20. The organic light-emitting diode according to claim 16, characterized in that, The light-emitting layer comprises the composition according to any one of claims 8-13.

21. An organic electroluminescent device, characterized in that, The organic electroluminescent device includes the organic electroluminescent diode as described in any one of claims 15-20.

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