Compound, composition, organic electroluminescent element, organic el display device, and organic el lighting

Abstract

To provide a compound that serves as a green light-emitting material, the compound exhibiting high luminous efficiency and superior solubility in organic solvents.SOLUTION: A compound represented by formula 1.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a compound, a composition, an organic electroluminescent device, an organic EL display device, and an organic EL lighting device. [Background technology]

[0002] In recent years, organic electroluminescent devices using organic thin films have been actively developed as thin-film electroluminescent devices, replacing those using inorganic materials. Organic electroluminescent devices (sometimes abbreviated as OLED) usually have a hole injection layer, a hole transport layer, an organic light-emitting layer, an electron transport layer, etc. between an anode and a cathode, and materials suitable for each of these layers are being developed, and development is also progressing for each of the emitted colors: red, green, and blue.

[0003] Methods for forming the organic layers of organic electroluminescent devices include vacuum deposition and wet film-forming (coating) methods. Vacuum deposition has the advantage of facilitating lamination, improving charge injection from the anode and / or cathode, and facilitating exciton confinement in the emissive layer. On the other hand, wet film-forming does not require a vacuum process, making it easy to achieve large-area devices. Furthermore, by using a coating solution containing a mixture of multiple materials with various functions, it is possible to easily form layers containing multiple materials with various functions. For this reason, in recent years, research and development of organic electroluminescent devices using film-forming methods has been actively conducted.

[0004] The light-emitting layer of an organic electroluminescent device requires a compound that exhibits high luminous efficiency and a narrow half-width, and the compound also needs to be soluble in an organic solvent used in a wet film-forming method. For example, Patent Document 1 describes a method for improving the solubility of a compound having a structure in which a six-membered aromatic heterocyclic group such as an azine ring is bonded to a DABNA skeleton, by changing one of the substituents of the azine ring to an alkyl group such as a tert-butyl group, thereby reducing the symmetry of the molecule and increasing the solubility. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] International Publication No. 2022 / 092046 Summary of the Invention [Problem to be solved by the invention]

[0006] However, the method described in Patent Document 1 does not provide sufficient luminous efficiency as a green light-emitting material, and the solubility in organic solvents when used in a wet film-forming method is also insufficient. In view of the above problems, an object of the present invention is to provide a compound that has good luminous efficiency and good solubility in organic solvents and can be used as a green luminescent material. [Means for solving the problem]

[0007] The gist of the present invention is as follows.

[0008] Aspect 1 of the present invention is The present invention relates to a compound represented by the following formula 1.

[0009] [ka]

[0010] (In formula 1, X 1 , X 2 are each independently NR, O or S. The R is an aromatic hydrocarbon group, an aromatic heterocyclic group, or an alkyl group. X 1 When R is NR, R is -O-, -S-, -C(R a ) It may be bonded to the benzene ring a by a 2- or single bond. X 2 When R is NR, R is -O-, -S-, -C(R a ) It may be bonded to the benzene ring b by a 2- or single bond. R a are each independently an alkyl group or an aromatic hydrocarbon group. Y 1 , Y 2 , Y 3 are each independently C or N, and at least one is N. Z 1 and Z 2 are each independently -C(R b )2-, O, N-R' or S. R b are each independently an alkyl group or an aromatic hydrocarbon group. The R' is an aromatic hydrocarbon group, an aromatic heterocyclic group, or an alkyl group. m and n are each independently an integer of 0 or greater.

[0011] Aspect 2 of the present invention relates to the compound of Aspect 1, wherein Said Z 1 and Z 2 -C(R b )2-.

[0012] A third aspect of the present invention is the compound of the second aspect, wherein R b is an alkyl group.

[0013] A fourth aspect of the present invention is a compound according to any one of the first to third aspects, wherein The compound wherein m and n are 1.

[0014] A fifth aspect of the present invention relates to a compound of any one of the first to fourth aspects, wherein The Y 1 and Y 2 is N.

[0015] A sixth aspect of the present invention relates to a compound of any one of the first to fifth aspects, wherein X 1 and X 2 is NR.

[0016] A seventh aspect of the present invention is the compound of the sixth aspect, wherein The compound wherein R is an aromatic hydrocarbon group.

[0017] Aspect 8 of the present invention is The present invention relates to a composition comprising the compound according to any one of Aspects 1 to 7 and an organic solvent.

[0018] A ninth aspect of the present invention is The present invention relates to an organic electroluminescent device comprising the compound of any one of embodiments 1 to 7.

[0019] A tenth aspect of the present invention is The present invention relates to an organic EL display device including the organic electroluminescent device of embodiment 9.

[0020] An eleventh aspect of the present invention is The present invention relates to an organic EL lighting device including the organic electroluminescent device of embodiment 9. [Effects of the Invention]

[0021] The compound of the present invention has good luminous efficiency and good solubility in organic solvents, and can be used as a green luminescent material. Furthermore, by using a composition using the compound of the present invention in the light-emitting layer of an organic electroluminescent element, an organic electroluminescent element with high luminous efficiency can be obtained. Furthermore, the compound of the present invention also has excellent solubility in organic solvents when used in a wet film-forming method. [Brief explanation of the drawings]

[0022] [Figure 1] FIG. 1 is a cross-sectional view showing a structural example of an organic electroluminescent device of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0023] Compounds according to embodiments of the present invention have a structure represented by Formula 1.

[0024] [ka]

[0025] (In formula 1, X 1 , X 2 are each independently NR, O or S. The R is an aromatic hydrocarbon group, an aromatic heterocyclic group, or an alkyl group. X 1 When R is NR, R is -O-, -S-, -C(R a ) It may be bonded to the benzene ring a by a 2- or single bond. X 2 When R is NR, R is -O-, -S-, -C(R a ) It may be bonded to the benzene ring b by a 2- or single bond. R a are each independently an alkyl group or an aromatic hydrocarbon group. Y 1 , Y 2 , Y 3 are each independently C or N, and at least one is N. Z 1 and Z 2 are each independently -C(R b )2-, O, N-R' or S. R b are each independently an alkyl group or an aromatic hydrocarbon group. The R' is an aromatic hydrocarbon group, an aromatic heterocyclic group, or an alkyl group. m and n are each independently an integer of 0 or greater.

[0026] <X 1 , X 2 > X 1 , X 2 are each independently NR, O or S. From the viewpoint of easily adjusting the emission wavelength to a preferred range, it is preferable to use X 1 , X 2 At least one of X is NR, more preferably X 1 and X 2 is NR. The R is an aromatic hydrocarbon group, an aromatic heterocyclic group, or an alkyl group.

[0027] The aromatic hydrocarbon group generally has 6 or more carbon atoms, and generally has 36 or less carbon atoms, preferably 30 or less carbon atoms, more preferably 24 or less carbon atoms, and most preferably 18 or less carbon atoms. Examples of aromatic hydrocarbon groups include a phenyl group, a biphenyl group, a terphenyl group, a quaterphenyl group, a naphthyl group, a phenanthrenyl group, a triphenylene group, and a naphthylphenyl group.

[0028] The number of carbon atoms in the aromatic heterocyclic group is usually 3 or more, preferably 4 or more, more preferably 5 or more, and is usually 36 or less, preferably 30 or less, more preferably 24 or less, and most preferably 18 or less. The aromatic heterocyclic group refers to an aromatic heterocycle having at least one free electron valence. Examples of the aromatic heterocycle include a pyridine ring, a pyrimidine ring, a pyrazine ring, a triazine ring, an imidazole ring, an oxazole ring, a thiazole ring, a benzothiazole ring, a benzoxazole ring, a benzimidazole ring, a quinoline ring, an isoquinoline ring, a quinoxaline ring, a quinazoline ring, a naphthyridine ring, and a phenanthridine ring. Of these, a pyridine ring, a pyrazine ring, a pyrimidine ring, a quinoline ring, an isoquinoline ring, a quinoxaline ring, and a quinazoline ring are preferred, a pyridine ring, a quinoline ring, and an isoquinoline ring are more preferred, and a pyridine ring is most preferred.

[0029] The alkyl group usually has 1 or more carbon atoms, preferably 3 or more carbon atoms, and more preferably 4 or more carbon atoms, and usually has 24 or less carbon atoms, preferably 12 or less carbon atoms, and more preferably 8 or less carbon atoms. The alkyl group may be a linear, branched, or cyclic alkyl group, and is preferably a linear or branched alkyl group from the viewpoint of solubility in an organic solvent when the compound according to the embodiment of the present invention is formed into a film by wet film formation as the light-emitting layer of an organic electroluminescent device. From the viewpoint of solubility, a linear alkyl group is more preferred, and a branched alkyl group is even more preferred from the viewpoint of shielding the molecule and reducing unnecessary quenching processes due to interactions with the outside. Examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, an n-hexyl group, a cyclohexyl group, a dodecyl group, and a cyclohexyl group.

[0030] The R is preferably an aromatic hydrocarbon group in order to improve the durability of the organic electroluminescent device and adjust the emission wavelength to a preferred range.

[0031] X 1 When R is NR, R is -O-, -S-, -C(R a ) It may be bonded to the benzene ring a by a 2- or single bond. X 2 When R is NR, R is -O-, -S-, -C(R a ) It may be bonded to the benzene ring b by a 2- or single bond. When R of the NR is an aromatic hydrocarbon group and this aromatic hydrocarbon group R is bonded to the benzene ring a or the benzene ring b via a single bond, the structure formed together with the benzene ring a or the benzene ring b is preferably a carbazole structure.

[0032] R a are each independently an alkyl group or an aromatic hydrocarbon group. The preferred range and specific examples are the same as those of R. From the viewpoint of solubility, R a is more preferably an alkyl group.

[0033] The hydrogen atoms of R may each be independently substituted with a substituent W.

[0034] Examples of the substituent W include deuterium, an alkyl group, an alkenyl group, an alkynyl group, an alkoxy group, an aryloxy group, a heteroaryloxy group, an alkoxycarbonyl group, a dialkylamino group, a diarylamino group, an arylalkylamino group, an acyl group, a halogen atom, a haloalkyl group, an alkylthio group, an arylthio group, a silyl group, a siloxy group, a cyano group, an aromatic hydrocarbon group, an aromatic heterocyclic group, an aralkyl group, and a heteroaralkyl group.

[0035] In order to adjust the solubility in an organic solvent and the emission wavelength within a preferred range when forming a film from the compound according to an embodiment of the present invention by wet film formation, the substituent W is preferably an alkyl group, an alkoxy group, a diarylamino group, a halogen atom, a cyano group, an aromatic hydrocarbon group, an aromatic heterocyclic group, or an aralkyl group, more preferably an alkyl group, a diarylamino group, an aromatic hydrocarbon group, or an aromatic heterocyclic group, and most preferably an alkyl group.

[0036] <Y 1 , Y 2 , Y 3 > Y 1 , Y 2 , Y 3 are each independently C or N, and at least one is N. The ring has high electron-withdrawing properties and is more likely to assume a planar structure, which is preferable from the viewpoint of quantum yield. 1 , Y 2 , Y 3 Preferably, two or more of Y are N. 1 and Y 2 More preferably, Y is N, 1 , Y 2 , Y 3 are most preferably all N.

[0037] <Z 1 , Z 2 > Z 1 and Z 2 are each independently -C(R b )2-, O, N-R' or S. From the viewpoint of solubility, Z 1 and Z 2 But -C(R b )2- is preferred.

[0038] R b are each independently an alkyl group or an aromatic hydrocarbon group. The preferred range and specific examples are the same as those of R. From the viewpoint of solubility, R b is more preferably an alkyl group. The R' is an aromatic hydrocarbon group, an aromatic heterocyclic group, or an alkyl group. The preferred range and specific examples are the same as those of R. In addition, the above R b and R' may each independently be substituted with the substituent W described above.

[0039] From the viewpoint of solubility in an organic solvent when the compound according to the embodiment of the present invention is formed into a film by wet film formation, the substituent W is preferably an alkyl group or an aralkyl group, and most preferably an alkyl group.

[0040] <m、n> m and n are each independently an integer of 0 or greater. From the viewpoint of solubility, both are preferably 1 or greater and 3 or less, more preferably 1 or greater and 2 or less, and most preferably 1.

[0041] <Benzene ring a, benzene ring b> In formula 1, the hydrogen atoms of the benzene rings a and b may each be independently substituted with the substituent W described above.

[0042] In order to adjust the solubility in an organic solvent when forming a film from the compound according to an embodiment of the present invention by wet film formation and the emission wavelength to a preferred range, the substituent W is preferably an alkyl group, an alkoxy group, a diarylamino group, a halogen atom, a cyano group, an aromatic hydrocarbon group, an aromatic heterocyclic group, or an aralkyl group, more preferably an alkyl group, a diarylamino group, an aromatic hydrocarbon group, or an aromatic heterocyclic group, and most preferably an alkyl group. From the viewpoint of solubility, the number of substituents W on the benzene ring a and the benzene ring b in formula 1 is preferably 1 or more and 2 or less, and most preferably 1 for both.

[0043] In one embodiment, the substituent W may be further substituted with deuterium, F, an alkyl group, or an aromatic hydrocarbon group. From the viewpoints of adjusting the emission wavelength and solubility, preferred types of substituents are deuterium, F, an alkyl group, an aromatic hydrocarbon group, or an aralkyl group, more preferred types are deuterium, F, an alkyl group, or an aromatic hydrocarbon group, and even more preferred types are deuterium or an alkyl group.

[0044] <Molecular weight> When forming a film from the compound according to the embodiment of the present invention by a coating method, from the viewpoints of solubility in an organic solvent and adjusting the emission wavelength to a green emission region, the molecular weight of the compound represented by formula 1 is preferably from 679 to 10,000, more preferably from 800 to 5,000, and even more preferably from 1,000 to 3,000.

[0045] <Specific examples of compounds represented by formula 1> Examples of the compound represented by formula 1 include the following compounds.

[0046] [ka]

[0047] [ka]

[0048] [ka]

[0049] [ka]

[0050] [ka]

[0051] The compound according to the embodiment of the present invention can be used in the light-emitting layer of an organic electroluminescent device.

[0052] The organic electroluminescent device has a light-emitting layer between an anode and a cathode, and may further have a hole injection layer, a hole transport layer, an electron transport layer, an electron injection layer, and the like. The structure and manufacturing method of an organic electroluminescent device having a hole injection layer, a hole transport layer, and an electron transport layer may be any known structure as described in WO 2024 / 004963.

[0053] The light-emitting layer can be produced by known methods such as vacuum deposition, wet film formation, etc. The wet film formation method is preferred because it is easy to produce a large-area layer and can form a layer containing a plurality of materials with various functions. The wet film-forming method is a method in which a composition dissolved in an organic solvent is applied, and then dried to remove the organic solvent, thereby forming a film of an emitting layer. Examples of the application method include wet film-forming methods such as spin coating, dip coating, die coating, bar coating, blade coating, roll coating, spray coating, capillary coating, inkjet printing, nozzle printing, screen printing, gravure printing, and flexographic printing, and the applied film is dried to form a film. Among these application methods, spin coating, spray coating, inkjet printing, and nozzle printing are preferred. When manufacturing an organic EL display device equipped with an organic electroluminescent element, the inkjet method or nozzle printing method is preferred, and the inkjet method is particularly preferred.

[0054] <Composition> The composition according to the embodiment of the present invention can include the compound according to the embodiment of the present invention and an organic solvent. Such a composition can be used for wet film formation.

[0055] Examples of the organic solvent include alkanes such as n-decane, cyclohexane, ethylcyclohexane, decalin, and bicyclohexane; aromatic hydrocarbons such as toluene, xylene, mesitylene, phenylcyclohexane, tetralin, and methylnaphthalene; halogenated aromatic hydrocarbons such as chlorobenzene, dichlorobenzene, and trichlorobenzene; and aromatic hydrocarbons such as 1,2-dimethoxybenzene, 1,3-dimethoxybenzene, anisole, phenetole, 2-methoxytoluene, 3-methoxytoluene, 4-methoxytoluene, 2,3-dimethylanisole, 2,4-dimethylanisole, and diphenyl ether. Examples of suitable solvents include ethers, aromatic esters such as phenyl acetate, phenyl propionate, methyl benzoate, ethyl benzoate, propyl benzoate, and n-butyl benzoate, alicyclic ketones such as cyclohexanone, cyclooctanone, and fenchone, alicyclic alcohols such as cyclohexanol and cyclooctanol, aliphatic ketones such as methyl ethyl ketone and dibutyl ketone, aliphatic alcohols such as butanol and hexanol, and aliphatic ethers such as ethylene glycol dimethyl ether, ethylene glycol diethyl ether, and propylene glycol-1-monomethyl ether acetate (PGMEA). Among these, from the viewpoints of viscosity and boiling point, alkanes, aromatic hydrocarbons, and aromatic esters are preferred, with aromatic hydrocarbons and aromatic esters being particularly preferred.

[0056] The boiling point of the organic solvent is usually 80°C or higher, preferably 100°C or higher, more preferably 120°C or higher, and usually 350°C or lower, preferably 330°C or lower, more preferably 300°C or lower. If the boiling point of the organic solvent is below this range, evaporation of the solvent from the composition during wet film formation may reduce film formation stability. If the boiling point of the organic solvent is above this range, residual solvent remaining after film formation may reduce film formation stability during wet film formation. From the viewpoint of forming a uniform coating film, it is preferable to combine two or more organic solvents having a boiling point of 150°C or higher.

[0057] The content of the compound relative to the total mass of the composition is preferably 0.001% by mass or more, more preferably 0.01% by mass or more, and is preferably 30.0% by mass or less, more preferably 20.0% by mass or less.

[0058] The composition may contain an organometallic compound, and the content of the organometallic compound relative to the total mass of the composition is preferably 0.001 mass% or more, more preferably 0.01 mass% or more, and is preferably 30.0 mass% or less, more preferably 20.0 mass% or less.

[0059] By setting the content of the compound and the organometallic compound within this range, holes and electrons can be efficiently injected from an adjacent layer (e.g., a hole transport layer or a hole blocking layer) into the light-emitting layer, thereby reducing the driving voltage.

[0060] The composition may contain only one of the compounds and organometallic compounds, or may contain a combination of two or more of them.

[0061] The organometallic compound contains a metal selected from Groups 7 to 11 of the long-form periodic table (hereinafter, unless otherwise specified, the term "periodic table" refers to the long-form periodic table). Preferred examples of the metal selected from Groups 7 to 11 of the periodic table include ruthenium, rhodium, palladium, silver, rhenium, osmium, iridium, platinum, and gold, with iridium or platinum being more preferred. The organometallic compound is preferably a Werner complex or an organometallic complex. The ligand of the complex is preferably a ligand in which a (hetero)aryl group is linked to pyridine, pyrazole, phenanthroline, or the like, such as a (hetero)arylpyridine ligand or a (hetero)arylpyrazole ligand, and more preferably a phenylpyridine ligand or a phenylpyrazole ligand. Here, the term "(hetero)aryl" refers to an aryl group or a heteroaryl group.

[0062] The composition may further contain other compounds, preferably phenols such as dibutylhydroxytoluene and dibutylphenol, which are known as antioxidants.

[0063] <Structure of organic electroluminescent device> As an example of the structure of an organic electroluminescent device according to an embodiment of the present invention, Fig. 1 shows a schematic diagram (cross section) of an example of the structure of an organic electroluminescent device 8. In Fig. 1, 1 represents a substrate, 2 represents an anode, 3 represents a hole injection layer, 4 represents a hole transport layer, 5 represents a light-emitting layer, 6 represents an electron transport layer, and 7 represents a cathode. The substrate, anode, hole injection layer, hole transport layer, electron transport layer, and cathode may have any known configuration as described in WO 2024 / 004963.

[0064] <Organic electroluminescent device and method for manufacturing the organic electroluminescent device> The organic electroluminescent device according to the embodiment of the present invention contains the compound according to the embodiment of the present invention, and an organic electroluminescent device having any layer structure can be manufactured by a known method including a step of forming an emitting layer by a wet film formation method using the composition according to the embodiment of the present invention.

[0065] <Organic EL display device> The organic EL display device (organic electroluminescent device display device) according to the embodiment of the present invention includes the organic electroluminescent device according to the embodiment of the present invention. The type and structure of the organic EL display device according to the embodiment of the present invention are not particularly limited, and the organic electroluminescent device according to the embodiment of the present invention can be assembled according to a conventional method using the organic electroluminescent device according to the embodiment of the present invention. For example, an organic EL display device according to an embodiment of the present invention can be formed by a method such as that described in "Organic EL Display" (Ohmsha, published August 20, 2004, by Tokito Shizuo, Adachi Chinaya, and Murata Hideyuki).

[0066] <Organic EL lighting> The organic EL lighting (organic electroluminescent element lighting) according to an embodiment of the present invention includes an organic electroluminescent element according to an embodiment of the present invention. There are no particular restrictions on the type and structure of the organic EL lighting according to an embodiment of the present invention, and it can be assembled according to a conventional method using the organic electroluminescent element according to an embodiment of the present invention.

Example

[0067] Hereinafter, embodiments of the present invention will be described with reference to examples. In the following synthesis examples, all reactions were carried out under a nitrogen stream. The solvents and solutions used in the reactions were degassed by an appropriate method such as nitrogen bubbling. Each evaluation was performed by the following method.

[0068] <Emission peak wavelength, full width at half maximum> The compounds obtained in the examples and comparative examples described below were dissolved in toluene (manufactured by Fujifilm Wako Pure Chemical Corporation, for spectroscopic analysis) at room temperature to prepare a 1×10 -5 mol / L solution. This solution was placed in a quartz cell with a Teflon (registered trademark) cock, and after nitrogen bubbling was carried out for 20 minutes or more, the phosphorescence spectrum was measured at room temperature. The wavelength showing the maximum value of the obtained phosphorescence spectrum intensity was defined as the maximum emission wavelength.

[0069] Also, the width of the spectrum intensity at half of the maximum emission wavelength was defined as the full width at half maximum. The full width at half maximum was obtained by reading the shorter wavelength exceeding a height of 0.5 and the longer wavelength below a height of 0.5 from the spectrum data normalized to a conversion height of 1, and taking the difference. If the maximum emission wavelength is 530 nm or more and the full width at half maximum is 30 nm or less, it can be judged as excellent.

[0070] Note that the following equipment was used for measuring the emission spectrum. · Device: Organic EL Quantum Yield Measurement Device C9920-02 manufactured by Hamamatsu Photonics K.K. · Light source: Monochromatic light source L9799-01 · Detector: Multi-channel detector PMA-11 · Excitation light: 380 nm

[0071] <Measurement of PL quantum yield> The PL quantum yield was measured as the luminous efficiency. PL quantum yield is an index that indicates the efficiency with which light is emitted from the light (energy) absorbed by a material. A PL quantum yield of 0.96 or higher is considered excellent.

[0072] The PL quantum yield was measured using the following equipment. Equipment: Hamamatsu Photonics OLED quantum yield measurement equipment C9920-02 Light source: Monochrome light source L9799-01 Detector: Multi-channel detector PMA-11 Excitation light: 380nm

[0073] <Solubility> The compound was mixed with cyclohexylbenzene to a concentration of 0.2% by mass, dissolved at 100°C, and heated. After heating, samples that were visually inspected for residual insoluble matter were rated as "A," and samples that contained residual insoluble matter were rated as "B."

[0074] [Example 1 (Compound 1)] <Reaction 1>

[0075] [ka]

[0076] A 1L recovery flask was charged with 19.2 g of 2-bromo-9,9-dihexylfluorene, 18.3 g of bis(pinacolato)diboron, 2.7 g of [1,1'-bis(diphenylphosphino)ferrocene]palladium(II) dichloride dichloromethane adduct, 13.7 g of potassium acetate, and 160 mL of 1,4-dioxane, and stirred in a 90°C oil bath for 7 hours. After cooling to room temperature, 500 mL of water was added and the mixture was extracted three times with ethyl acetate. The oil phase was dried over magnesium sulfate, and the solvent was removed under reduced pressure. The resulting residue was purified by silica gel column chromatography (ethyl acetate / hexane = 1 / 9) to yield 20.3 g of 2-(9,9-dihexylfluorene)-boronic acid pinacol ester.

[0077] <Reaction 2>

[0078] [ka]

[0079] A 300 mL recovery flask was charged with 3.9 g of 2-(9,9-dihexylfluorene)-boronic acid pinacol ester, 2.4 g of 1-bromo-3-iodobenzene, 0.06 g of bis(triphenylphosphine)palladium(II) dichloride, 10 mL of 2 M aqueous potassium phosphate solution, 10 mL of ethanol, and 20 mL of toluene, and the mixture was stirred in an oil bath at 90°C for 7 hours. Brine was added, the mixture was shaken, the aqueous phase was removed, and the oil phase was dried over magnesium sulfate. The solvent was removed under reduced pressure, and the resulting residue was purified by silica gel column chromatography (hexane) to yield 2.1 g of 2-(3-bromophenyl)-9,9-dihexylfluorene.

[0080] <Reaction 3>

[0081] [ka]

[0082] A 50 mL two-necked recovery flask was charged with 2.1 g of 2-(3-bromophenyl)-9,9-dihexylfluorene and 5 mL of tetrahydrofuran. After dissolving, 3 mL of 1.6 M n-butyllithium in n-hexane was added dropwise in an acetone bath at -78 °C and stirred for 1 hour to prepare the lithiation solution. A separate 50 mL recovery flask was charged with 400 mg of cyanuric chloride and 5 mL of tetrahydrofuran. After dissolving, the lithiation solution was added dropwise in an acetone bath at -78 °C. The mixture was warmed to room temperature and stirred for 3 hours. Water was added in an ice bath, followed by separation with dichloromethane. The oil phase was dried over magnesium sulfate. The solvent was removed under reduced pressure, and the resulting residue was purified by silica gel column chromatography (dichloromethane / hexane = 1 / 9 to 1 / 4) to obtain 0.7 g of 2-chloro-4,6-bis[3-(9,9-dihexylfluoren-2-yl)phenyl]-1,3,5-triazine.

[0083] <Reaction 4>

[0084] [ka]

[0085] In a 100 mL two-necked flask, 0.66 g of intermediate 1 (synthesized according to the method for producing intermediate 2 described in WO 2022 / 092046), 0.84 g of 2-chloro-4,6-bis[3-(9,9-dihexylfluoren-2-yl)phenyl]-1,3,5-triazine, 0.05 g of [tetrakis(triphenylphosphine)palladium(0)], 1.3 mL of 2 M aqueous potassium phosphate solution, 7 mL of ethanol, and 14 mL of toluene were added and stirred in a 90 ° C oil bath for 1.5 hours. After cooling to room temperature, tetrahydrofuran was added, followed by drying over magnesium sulfate and filtration. The solvent in the filtrate was removed under reduced pressure, and the resulting residue was washed with toluene to obtain 0.71 g of compound 1. The evaluation results of Compound 1 are shown in Table 1.

[0086] [Comparative Example 1 (Compound 2)] Compound 2 shown in the following formula was synthesized according to the production method of compound D-2 described in WO 2022 / 092046. The evaluation results of Compound 2 are shown in Table 1.

[0087] [ka]

[0088] [Comparative Example 2 (Compound 3)] Compound 3 shown in the following formula was synthesized according to the production method of compound D-3 described in WO 2022 / 092046. The evaluation results of Compound 3 are shown in Table 1.

[0089] [ka]

[0090] [Table 1]

[0091] The compound of Comparative Example 1 (Compound 2) was insufficient in both luminous efficiency and solubility in organic solvents. The compound of Comparative Example 2 (Compound 3) did not sufficiently shift the maximum emission wavelength to the long wavelength side, resulting in insufficient green emission. In contrast, the compound of Example 1 (Compound 1) had sufficient luminous efficiency and solubility in organic solvents, and emitted green light.

[0092] The charge transporting polymer compounds used in the hole transport layers of the organic electroluminescent devices in the following Examples, Comparative Examples, and Reference Examples were synthesized by the method described in WO 2019 / 177175.

[0093] [Example 2] An organic electroluminescent device was fabricated in the following manner. A 50-nm-thick indium tin oxide (ITO) transparent conductive film (Geomatec Co., Ltd., sputter-deposited) was deposited on a glass substrate and patterned into 2-mm-wide stripes using standard photolithography and hydrochloric acid etching to form the anode. The substrate with the ITO pattern formed was then ultrasonically cleaned with a surfactant solution, rinsed with ultrapure water, ultrasonically cleaned with ultrapure water, and rinsed with ultrapure water again, followed by drying with compressed air and finally cleaning with ultraviolet ozone.

[0094] A composition for forming a hole injection layer was prepared by dissolving 3.0 wt % of a hole transporting polymer compound having a repeating structure of the following formula (P-1) and 0.6 wt % of an electron accepting compound (HI-1) in ethyl benzoate.

[0095] [ka]

[0096] [ka]

[0097] This solution was spin-coated onto the substrate in the atmosphere and dried on a hot plate in the atmosphere at 240° C. for 30 minutes to form a uniform thin film with a thickness of 40 nm, which served as a hole injection layer.

[0098] Next, 100 parts by mass of a charge transporting polymer compound having the following structural formula (HT-1) was dissolved in mesitylene to prepare a 2.5% by mass solution.

[0099] [ka]

[0100] This solution was spin-coated in a nitrogen glove box onto the substrate on which the hole injection layer had been coated, and dried on a hot plate in the nitrogen glove box at 230°C for 30 minutes to form a uniform thin film with a thickness of 60 nm, which served as a hole transport layer.

[0101] Subsequently, as materials for the light-emitting layer, 75 parts by mass of a compound represented by the following structural formula (H-1), 25 parts by mass of a compound represented by the following structural formula (H-2), 20 parts by mass of a compound represented by the following structural formula (D-1), and 2 parts by mass of the aforementioned compound 1 were weighed out and dissolved in cyclohexylbenzene to prepare a 6.0% by mass solution.

[0102] [ka]

[0103] This solution was spin-coated in a nitrogen glove box onto the substrate on which the hole transport layer had been coated, and dried on a hot plate in the nitrogen glove box at 120°C for 20 minutes to form a uniform thin film with a thickness of 55 nm, which served as the light-emitting layer.

[0104] The substrate on which the light-emitting layer had been formed was placed in a vacuum deposition device, and the inside of the device was heated to 2 × 10 -4The pressure was evacuated until it reached a pressure of 0.1 Pa or less.

[0105] Next, a compound represented by the following structural formula (HB-1) and 8-hydroxyquinolinolatolithium were co-deposited on the light-emitting layer at a thickness ratio of 2:3 by vacuum deposition at a rate of 1 Å / sec to form a hole-blocking layer with a thickness of 30 nm.

[0106] [ka]

[0107] Next, a 2 mm wide striped shadow mask was attached to the substrate as a mask for cathode deposition, perpendicular to the ITO stripes of the anode, and the substrate was placed in another vacuum deposition apparatus. Aluminum was then heated using a molybdenum boat, and an 80 nm thick aluminum layer was formed at a deposition rate of 1 to 8.6 Å / sec to form the cathode. In this way, an organic electroluminescent device with a 2 mm x 2 mm light-emitting area was obtained.

[0108] Comparative Example 3 An organic electroluminescent device was produced in the same manner as in Example 2, except that Compound 2 was used instead of Compound 1 as the material for the light-emitting layer.

[0109] Comparative Example 4 An organic electroluminescent device was produced in the same manner as in Example 2, except that Compound 3 was used instead of Compound 1 as the material for the light-emitting layer.

[0110] Comparative Example 5 An organic electroluminescent device was produced in the same manner as in Example 2, except that Compound 4 represented by the following structural formula was used instead of Compound 1 as the material for the light-emitting layer.

[0111] [ka]

[0112] Comparative Example 6 An organic electroluminescent device was produced in the same manner as in Example 2, except that Compound 5 represented by the following structural formula was used instead of Compound 1 as the material for the light-emitting layer.

[0113] [ka]

[0114] The organic electroluminescent devices obtained in Example 2 and Comparative Examples 3 to 6 were measured to obtain a luminance of 1,000 cd / m 2 The current efficiency (cd / A) and external quantum yield (%) were measured.

[0115] Table 2 shows the ratios of the current efficiencies of the organic electroluminescent devices of Example 2 and Comparative Examples 3 to 5 (hereinafter referred to as "relative current efficiencies") when the current efficiency of the organic electroluminescent device of Comparative Example 6 is taken as 1.

[0116] Table 2 also shows the ratios of the external quantum yields of the organic electroluminescent devices of Example 2 and Comparative Examples 3 to 5 (hereinafter referred to as "relative external quantum yields") when the external quantum yield of the organic electroluminescent device of Comparative Example 6 is taken as 1.

[0117] [Table 2]

[0118] From the results in Table 2, it was found that the organic electroluminescent device using the compound of the present invention had high current efficiency and external quantum yield, and exhibited good device characteristics. [Industrial Applicability]

[0119] The organic electroluminescent device according to the embodiment of the present invention and the composition according to the embodiment of the present invention can be suitably used in, for example, organic EL display devices and organic EL lighting. [Explanation of symbols]

[0120] 1 board 2 Anode 3. Hole injection layer 4. Hole transport layer 5. Light-emitting layer 6 Electron transport layer 7 Cathode 8. Organic electroluminescent device

Claims

1. A compound represented by the following formula 1: 【Chemical 1】 (In formula 1, X １ , X ２ are each independently N—R, O or S. The R is an aromatic hydrocarbon group, an aromatic heterocyclic group, or an alkyl group. X １ is N-R, the R is -O-, -S-, -C(R ａ ) ２ Alternatively, it may be bonded to the benzene ring a via a single bond. X ２ is N-R, the R is -O-, -S-, -C(R ａ ) ２ Alternatively, it may be bonded to the benzene ring b via a single bond. The R ａ are each independently an alkyl group or an aromatic hydrocarbon group. Y １ , Y ２ , Y ３ are each independently C or N, and at least one is N. Z １ and Z ２ are each independently -C(R ｂ ) ２ -, O, N--R' or S. The R ｂ are each independently an alkyl group or an aromatic hydrocarbon group. The R' is an aromatic hydrocarbon group, an aromatic heterocyclic group, or an alkyl group. m and n are each independently an integer of 0 or more.

2. Said Z １ and Z ２ -C(R ｂ ) ２ The compound of claim 1, wherein

3. The R ｂ The compound of claim 2, wherein is an alkyl group.

4. The compound of claim 1 , wherein m and n are 1.

5. The Y １ and Y ２ The compound of claim 1 , wherein is N.

6. The X １ and X ２ The compound of claim 1 , wherein is N—R.

7. The compound of claim 6 , wherein R is an aromatic hydrocarbon group.

8. A composition comprising the compound according to any one of claims 1 to 7 and an organic solvent.

9. An organic electroluminescent device comprising the compound according to any one of claims 1 to 7.

10. An organic EL display device comprising the organic electroluminescent device according to claim 9 .

11. An organic electroluminescent lighting device comprising the organic electroluminescent device according to claim 9.

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