Materials for organic electric field light-emitting elements and organic electric field light-emitting elements

Abstract

This invention provides a high-efficiency organic EL element with high driving stability and a suitable material for the organic EL element. The organic EL element material comprises an indole-carbazole compound represented by general formula (1). Here, ring a is represented by formula (1a), X is NR, S, O, or CR2, and Ar... 1 Ar 2 The aromatic heterocyclic group represented by formula (1b) is Y, which is N or CR, but at least one of them is N, L 1 It is an aromatic hydrocarbon group. The material used in the organic EL element is suitable as the main body of the light-emitting layer or the hole-blocking layer of the organic EL element.

Description

Technical Field

[0001] This invention relates to a material for an organic electric field light-emitting element and an organic electric field light-emitting element using the same. Background Technology

[0002] By applying a voltage to an organic field-emitting element (called an organic electroluminescence (EL) element), holes are injected into the emissive layer from the anode, and electrons are injected into the emissive layer from the cathode. Furthermore, in the emissive layer, the injected holes and electrons recombine to generate excitons. At this point, according to the statistical law of electron spin, singlet and triplet excitons are generated in a 1:3 ratio. The internal quantum efficiency limit of a fluorescent organic EL element using singlet exciton-based luminescence is approximately 25%. On the other hand, it is known that a phosphorescent organic EL element using triplet exciton-based luminescence achieves an internal quantum efficiency of up to 100% when intersystem crossings are efficiently performed from singlet excitons.

[0003] However, further improvements in efficiency and low-voltage characteristics for phosphorescent organic EL devices remain technical challenges.

[0004] High-efficiency organic electroluminescent (EL) devices utilizing delayed fluorescence are currently being developed. For example, an organic EL device utilizing the triplet-triplet fusion (TTF) mechanism, one of the mechanisms of delayed fluorescence, is known. The TTF mechanism utilizes the phenomenon of generating a singlet exciton through the collision of two triplet excitons, and is theoretically believed to increase the internal quantum efficiency to 40%. However, compared to phosphorescent organic EL devices, the efficiency is lower, thus requiring further improvements in efficiency.

[0005] Patent Document 1 discloses an organic EL device utilizing a thermally activated delayed fluorescence (TADF) mechanism. The TADF mechanism utilizes the phenomenon that in materials with a small energy difference between singlet and triplet levels, an inverse intersystem crossing occurs from a triplet exciton to a singlet exciton, theoretically increasing the internal quantum efficiency to 100%. However, similar to phosphorescent luminescent devices, further improvements in efficiency and low voltage characteristics are required.

[0006] Existing technical documents

[0007] Patent documents

[0008] Patent Document 1: WO2011 / 070963 A

[0009] Patent Document 2: KR 2014094408 A

[0010] Patent Document 3: KR ​​2017060836 A

[0011] Patent Document 4: CN 103193717 A

[0012] Patent Document 5: WO2011 / 005060 A

[0013] Patent Documents 2 and 3 disclose a compound having two triazine rings.

[0014] Patent documents 4 and 5 disclose a compound having two pyrimidine rings and being formed by linking the pyrimidine rings with phenylene.

[0015] However, these do not specify the compounds of the present invention, nor do they demonstrate the usefulness of organic EL elements using the compounds. Summary of the Invention

[0016] To apply organic EL elements to display devices such as flat panel displays, it is necessary to improve the luminous efficiency of the elements while ensuring sufficient stability during driving. In view of the above-mentioned situation, the present invention aims to provide a practically useful organic EL element with high efficiency and low voltage characteristics, and a suitable compound thereof.

[0017] The inventors have conducted intensive research and found that using condensed aromatic heterocyclic compounds represented by the following general formula (1) in organic EL elements exhibits excellent properties, thus completing the present invention.

[0018] The present invention is a material for an organic electric field light-emitting element comprising a compound represented by general formula (1).

[0019] [Chemistry 1]

[0020]

[0021] Here, ring a is represented by equation (1a), and ring a and its adjacent rings are condensed at any position.

[0022] X is NR 11 S, O or CR 12 R 13 R 11 R 12 and R 13Each of these can be independently represented as an aliphatic hydrocarbon group having 1 to 10 carbon atoms, an aromatic hydrocarbon group having 6 to 30 carbon atoms (substituted or unsubstituted), an aromatic heterocyclic group having 3 to 16 carbon atoms (substituted or unsubstituted), or a substituted or unsubstituted linked aromatic group consisting of 2 to 5 of these aromatic rings.

[0023] R independently represents hydrogen, deuterium, an aliphatic hydrocarbon group having 1 to 10 carbon atoms, an aromatic hydrocarbon group having 6 to 30 carbon atoms (substituted or unsubstituted), or an aromatic heterocyclic group having 3 to 16 carbon atoms (substituted or unsubstituted).

[0024] Ar 1 and Ar 2 Independently represented by the aromatic heterocyclic group of formula (1b),

[0025] Ar 3 Independently refers to an aromatic hydrocarbon group having 6 to 30 carbon atoms, substituted or unsubstituted aromatic heterocyclic group having 3 to 16 carbon atoms, or a substituted or unsubstituted linked aromatic group consisting of 2 to 5 of these aromatic rings.

[0026] R 14 Independently representing hydrogen, deuterium, an aliphatic hydrocarbon group having 1 to 10 carbon atoms, an aromatic hydrocarbon group having 6 to 30 carbon atoms (substituted or unsubstituted), an aromatic heterocyclic group having 3 to 16 carbon atoms (substituted or unsubstituted), or a substituted or unsubstituted linked aromatic group consisting of 2 to 5 of these aromatic rings.

[0027] Y independently represents N or CR 14 At least one of them is N.

[0028] L 1 It indicates an aromatic hydrocarbon group with 6 to 30 carbon atoms, whether substituted or unsubstituted.

[0029] As L 1 The following examples can be listed as phenylene compounds represented by formula (1c) or formula (1d).

[0030] [Chemistry 2]

[0031]

[0032] X can be NR 11 Here, R 11 R in general formula (1) 11 They have the same meaning.

[0033] As compounds represented by general formula (1), compounds represented by general formula (2) can be listed.

[0034] [Chemistry 3]

[0035]

[0036] Here, rings a, R, R 14 L 1 Ar 2 Ar 3 These have the same meaning as those in general formula (1).

[0037] More specifically, compounds represented by any of the general formulas (3) to (8) can be listed.

[0038] [Chemistry 4]

[0039]

[0040] [Chemistry 5]

[0041]

[0042] (Here, R, L) 1 Ar 2 Ar 3 These have the same meaning as in general formula (1), R 15 R in general formula (1) 11 (meaning the same thing)

[0043] Among them, compounds represented by any one of general formulas (3) to (5) may be preferably listed.

[0044] The compound represented by general formula (1) ideally has an absolute value of electron affinity (EA) greater than 2.6 eV and an absolute value of ionization potential (IP) less than 6.1 eV.

[0045] The present invention is an organic electric field light-emitting element, which is formed by stacking an anode, an organic layer and a cathode on a substrate, wherein at least one of the organic layers is an organic layer containing the material of the organic electric field light-emitting element.

[0046] The organic layer containing the material for the organic electric field light-emitting element may be at least one layer selected from the group consisting of a light-emitting layer, an electron transport layer, and a hole blocking layer.

[0047] The light-emitting layer comprises a host material and a light-emitting dopant material, which may be an organometallic complex comprising at least one metal selected from the group consisting of ruthenium, rhodium, palladium, silver, rhenium, osmium, iridium, platinum, and gold. Preferably, the light-emitting layer comprises a material for organic electric field light-emitting elements as the host material.

[0048] The luminescent dopant material may also be a thermally activated delayed fluorescence dopant material.

[0049] Alternatively, a hole blocking layer may be disposed adjacent to the light-emitting layer, and the hole blocking layer contains the material for the organic electric field light-emitting element.

[0050] The organic EL element material of the present invention has a structure represented by general formula (1). In compounds with this structural characteristic, the lowest unoccupied molecular orbital (LUMO), which affects the electron injection transport properties of the material, is distributed centered on a nitrogen-containing 6-membered ring. Furthermore, the compounds of the present invention have two or more nitrogen-containing 6-membered rings; therefore, by changing the number or linkage of the connecting groups present between the nitrogen-containing 6-membered rings, for example, the LUMO orbitals can be expanded, thereby improving the electron injection transport properties and thus controlling the electron injection transport properties of the material at a high level.

[0051] On the other hand, the highest occupied molecular orbital (HOMO) that affects the hole injection transport properties of a material is located on the condensed aromatic heterocycle represented by indobenzocarbazole. The distribution of the HOMO orbital can be adjusted by changing the ring-condensation form of the condensed aromatic heterocycle, the type of substituent, or the substituent introduction site, thereby controlling the hole injection transport properties of the material to a high degree.

[0052] Because of the characteristics described above, the material of this invention is a material with two-charge (electron / hole) injection transport properties suitable for the device structure. By using the material in organic EL devices, it is possible to reduce the driving voltage of the device and achieve high luminous efficiency.

[0053] In addition, the organic EL element material of the present invention exhibits good amorphous properties and high thermal stability, while being extremely stable in the excited state. Therefore, the organic EL element using the material has a long driving life and practical-level durability. Attached Figure Description

[0054] Figure 1 This is a cross-sectional view showing a structural example of an organic EL element. Detailed Implementation

[0055] The material for the organic electric field light-emitting element of the present invention is represented by the general formula (1).

[0056] In general formula (1), ring a is the ring represented by formula (1a), and ring a is condensed at any position with the adjacent ring.

[0057] Ar 1 and Ar 2Independently, it represents the aromatic heterocyclic group as shown in formula (1b). Here, Y independently represents N or CR. 14 At least one of them is N. Preferably, at least two of Y in formula (1b) are N, more preferably all of Y are N.

[0058] R 14 Independently representing hydrogen, deuterium, an aliphatic hydrocarbon group having 1 to 10 carbon atoms, an aromatic hydrocarbon group having 6 to 30 carbon atoms (substituted or unsubstituted), an aromatic heterocyclic group having 3 to 16 carbon atoms (substituted or unsubstituted), or a linked aromatic group having substituted or unsubstituted aromatic rings of these groups. Preferably, it is an aromatic hydrocarbon group having 6 to 30 carbon atoms (substituted or unsubstituted) or an aromatic heterocyclic group having 3 to 16 carbon atoms (substituted or unsubstituted). More preferably, it is an aromatic hydrocarbon group having 6 to 10 carbon atoms (substituted or unsubstituted). Further preferably, it is phenyl.

[0059] In this specification, the term "linked aromatic group" refers to an aromatic hydrocarbon group or an aromatic heterocyclic group whose aromatic rings are linked by single bonds. These linkages can be linear or branched, and the aromatic rings can be the same or different.

[0060] Ar 3 The aromatic hydrocarbon group having 6 to 30 carbon atoms (substituted or unsubstituted), an aromatic heterocyclic group having 3 to 16 carbon atoms (substituted or unsubstituted), or a linked aromatic group having 2 to 5 of these aromatic rings linked together, preferably an aromatic hydrocarbon group having 6 to 10 carbon atoms (substituted or unsubstituted), or an aromatic heterocyclic group having 3 to 12 carbon atoms (substituted or unsubstituted), more preferably an aromatic hydrocarbon group having 6 to 10 carbon atoms (substituted or unsubstituted). The aromatic heterocyclic group preferably contains N, O, or S as a heteroatom.

[0061] As Ar 3Specific examples of unsubstituted aromatic hydrocarbon groups and unsubstituted aromatic heterocyclic groups include those derived from benzene, naphthalene, anthracene, fluoranthene, phenanthrene, triphenylene, pyridine, pyrimidine, triazine, thiophene, isothiazole, thiazole, pyridazine, pyrrole, pyrazole, imidazole, pyrazine, furan, isoxazole, oxazole, quinoline, isoquinoline, quinoxaline, quinazoline, benzotriazole, phthalazine, indole, benzofuran, benzothiophene, benzooxazole, benzothiazole, indazole, benzoimidazolium, benzoisothiazolium, benzothiadiazole, dibenzofuran, dibenzothiophene, dibenzoselenophene, benzocarbazole, benzonaphthothiophene, benzonaphthofuran, phenanthrene, or carbazole. Preferably, the aromatic group can be derived from benzene, naphthalene, pyridine, pyrimidine, triazine, thiophene, isothiazole, thiazole, pyridazine, pyrrole, pyrazole, imidazole, triazole, thiadiazole, pyrazine, furan, isoxazole, oxazole, quinoline, isoquinoline, quinoxaline, quinazoline, phthalazine, indole, benzofuran, benzothiophene, benzoxazole, benzothiazole, indazole, benzimazole, benzoisothiazolium, or benzothiadiazole, dibenzofuran, dibenzothiophene, or carbazole. More preferably, the aromatic group derived from benzene is a phenyl group.

[0062] L 1 It is an aromatic hydrocarbon group with 6 to 30 carbon atoms, either substituted or unsubstituted, preferably a p-phenylene or meta-phenylene represented by formula (1c) or formula (1d). Specific examples of aromatic hydrocarbon groups are similar to Ar. 3 The same applies to aromatic hydrocarbon groups.

[0063] X is NR 11 S, O or CR 12 R 13 NR is preferred. 11 .

[0064] R 11 R 12 and R 13 Each of these aromatic groups is independently an aliphatic hydrocarbon group having 1 to 10 carbon atoms, an aromatic hydrocarbon group having 6 to 30 carbon atoms (substituted or unsubstituted), an aromatic heterocyclic group having 3 to 16 carbon atoms (substituted or unsubstituted), or a linked aromatic group consisting of 2 to 5 of these aromatic rings. Preferably, it is an aromatic hydrocarbon group having 6 to 30 carbon atoms (substituted or unsubstituted), or an aromatic heterocyclic group having 3 to 16 carbon atoms (substituted or unsubstituted), and more preferably, it is an aromatic hydrocarbon group having 6 to 10 carbon atoms (substituted or unsubstituted). Furthermore, it is also preferred to be a linked aromatic group consisting of 2 to 3 aromatic rings of an aromatic hydrocarbon group having 6 to 10 carbon atoms.

[0065] R independently represents hydrogen, deuterium, an aliphatic hydrocarbon group having 1 to 10 carbon atoms, an aromatic hydrocarbon group having 6 to 30 carbon atoms, or an aromatic heterocyclic group having 3 to 16 carbon atoms. Preferably, it is hydrogen, deuterium, phenyl, or an aromatic heterocyclic group having 3 to 12 carbon atoms. More preferably, it is hydrogen, deuterium, phenyl, or carbazole.

[0066] R, R 14 and Ar 3 As a monovalent base, when these notations appear multiple times in the formula, they can be the same or different each time they appear.

[0067] In R, R 11 R 12 R 13 and R 14 When the group is an aliphatic hydrocarbon with 1 to 10 carbon atoms, it can be linear, branched, or cyclic. Specific examples include: methyl, ethyl, propyl, butyl, tert-butyl, pentyl, hexyl, cyclohexyl, heptyl, octyl, nonyl, decyl, etc. Alkyl groups with 1 to 4 carbon atoms are preferred.

[0068] As R, R 11 R 12 R 13 and R 14 Specific examples of aromatic hydrocarbon groups or aromatic heterocyclic groups include those derived from benzene, naphthalene, anthracene, fluoranthene, phenanthrene, triphenylene, pyridine, pyrimidine, triazine, thiophene, isothiazole, thiazole, pyridazine, pyrrole, pyrazole, imidazole, pyrazine, furan, isoxazole, oxazole, quinoline, isoquinoline, quinoxaline, quinazoline, benzotriazole, phthalazine, indole, benzofuran, benzothiophene, benzooxazole, benzothiazole, indazole, benzoimidazolium, benzoisothiazolium, benzothiadiazole, dibenzofuran, dibenzothiophene, dibenzoselenophene, benzocarbazole, benzonaphthothiophene, benzonaphthofuran, phenanthrene, or carbazole. Preferably, the aromatic group can be derived from benzene, naphthalene, pyridine, pyrimidine, triazine, thiophene, isothiazole, thiazole, pyridazine, pyrrole, pyrazole, imidazole, triazole, thiadiazole, pyrazine, furan, isoxazole, oxazole, quinoline, isoquinoline, quinoxaline, quinazoline, phthalazine, indole, benzofuran, benzothiophene, benzoxazole, benzothiazole, indazole, benzimazole, benzoisothiazolium, or benzothiadiazole, dibenzofuran, dibenzothiophene, or carbazole. More preferably, the aromatic group is derived from benzene or carbazole.

[0069] In this specification, aromatic hydrocarbon groups, aromatic heterocyclic groups, and linked aromatic cyclic groups may have substituents. Preferred substituents, in the case of aromatic hydrocarbon groups, aromatic heterocyclic groups, and linked aromatic cyclic groups, include: alkyl groups having 1 to 5 carbon atoms, alkenyl groups having 2 to 5 carbon atoms, alkoxy groups having 1 to 5 carbon atoms, deuterium, halogens, amino groups, cyano groups, etc.

[0070] As a preferred form of the compound represented by general formula (1), there is a compound represented by general formula (2) or any of general formulas (3) to (8), and more preferably a compound represented by any of general formulas (3) to (5). In general formulas (2) to (8), the symbols used in general formula (1) have the same meaning.

[0071] Furthermore, it is preferable that the absolute value of the electron affinity (EA) of the compound represented by general formula (1) is greater than 2.6 eV and the absolute value of the ionization potential (IP) is less than 6.1 eV. The value of IP can be the value of the ionization potential (IP) obtained by photoelectron spectroscopy in a thin film obtained by vapor deposition of the material, and EA can be calculated using the value of the energy gap and the IP value, the value of which is determined by measuring the absorption spectrum and based on its absorption end.

[0072] The following are specific examples of compounds represented by general formula (1), but are not limited to these exemplified compounds.

[0073] [Chemistry 6]

[0074]

[0075] [Chemistry 7]

[0076]

[0077] [Chemistry 8]

[0078]

[0079] [Chemistry 9]

[0080]

[0081] [Chemistry 10]

[0082]

[0083] [Chemistry 11]

[0084]

[0085] [Chemistry 12]

[0086]

[0087] [Chemistry 13]

[0088]

[0089] [Chemistry 14]

[0090]

[0091] [Chemistry 15]

[0092]

[0093] [Chemistry 16]

[0094]

[0095] [Chemistry 17]

[0096]

[0097] The organic field light-emitting element material of the present invention (also referred to as the compound of the present invention or the compound represented by general formula (1) or azazine compound) provides an excellent organic field light-emitting element by being contained in at least one organic layer of an organic EL element formed by stacking an anode, multiple organic layers and a cathode on a substrate. The organic layer contained herein is suitable as a light-emitting layer, an electron transport layer or a hole blocking layer. Here, in the case of using it as a light-emitting layer, in addition to being used as a host material for a light-emitting layer containing dopants with fluorescent, delayed fluorescent or phosphorescent properties, the compound of the present invention can also be used as an organic light-emitting material with radiofluorescence and delayed fluorescence. The compound of the present invention is particularly preferably contained as a host material for a light-emitting layer containing phosphorescent dopants.

[0098] When used as an organic light-emitting material for both radiofluorescence and delayed fluorescence (also known as a thermally activated delayed fluorescence dopant material), it is preferable to use other organic compounds whose excitation singlet energy or excitation triplet energy has a higher value than that of the compound of the present invention as the host material.

[0099] Next, an organic EL element using the organic electric field light-emitting element material of the present invention will be described.

[0100] The organic EL element of the present invention has an organic layer comprising at least one light-emitting layer between the anode and cathode stacked on a substrate, wherein the at least one organic layer comprises the organic field light-emitting element material of the present invention. Advantageously, the light-emitting layer simultaneously comprises a phosphorescent dopant and the organic field light-emitting element material of the present invention.

[0101] Secondly, the structure of the organic EL element of the present invention will be described with reference to the accompanying drawings, but the structure of the organic EL element of the present invention is not limited by any of the illustrations.

[0102] Figure 1This is a cross-sectional view showing a typical organic EL element structure used in this invention. 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. In the organic EL element of this invention, an exciton blocking layer may be provided adjacent to the light-emitting layer. Additionally, an electron blocking layer may be provided between the light-emitting layer and the hole injection layer. The exciton blocking layer may be inserted into either the anode side or the cathode side of the light-emitting layer, or simultaneously into both sides. In the organic EL element of this invention, a substrate, an anode, a light-emitting layer, and a cathode are required layers. Among the layers other than the required layers, a hole injection transport layer and an electron injection transport layer are preferred. Furthermore, a hole blocking layer is preferred between the light-emitting layer and the electron injection transport layer. Furthermore, a hole injection transport layer refers to either or both of the hole injection layer and the hole transport layer, and an electron injection transport layer refers to either or both of the electron injection layer and the electron transport layer.

[0103] Furthermore, it can also be used with Figure 1 In the opposite structure, the cathode 7, electron transport layer 6, light-emitting layer 5, hole transport layer 4, and anode 2 are sequentially stacked on the substrate 1. In this case, layers may be added or omitted as needed.

[0104] -Substrate-

[0105] The organic EL element of the present invention is preferably supported by a substrate. The substrate is not particularly limited, as long as it is a substrate commonly used in organic EL elements, such as a substrate containing glass, transparent plastic, quartz, etc.

[0106] -anode-

[0107] As the anode in an organic EL element, anodes with a high work function (4 eV or higher) such as metals, alloys, conductive compounds, and mixtures thereof are preferably used as electrode materials. Specific examples of such electrode materials include metals such as Au, CuI, indium tin oxide (ITO), SnO2, and ZnO, which are conductive transparent materials. Alternatively, amorphous materials such as IDIXO (In2O3-ZnO) that can be used to form transparent conductive films can also be used. The anode can be formed into a thin film by methods such as vapor deposition or sputtering, and a pattern of the desired shape can be formed by photolithography. Alternatively, if pattern precision is not critical (around 100 μm or higher), a pattern can be formed by separating the desired shape of the mask during the vapor deposition or sputtering of the electrode material. Alternatively, when using a coatingable material such as an organic conductive compound, wet film formation methods such as printing or coating can be used. Ideally, the transmittance should be greater than 10% when light is emitted from the anode, and the sheet resistance of the anode is preferably several hundred Ω / Y or less. Furthermore, the film thickness also depends on the material, but is usually selected in the range of 10nm to 1000nm, preferably 10nm to 200nm.

[0108] -cathode-

[0109] On the other hand, cathodes can be made using metals (called electron-injecting metals), alloys, conductive compounds, and mixtures thereof with low work functions (below 4 eV) as electrode materials. Specific examples of such electrode materials include: sodium, sodium-potassium alloys, magnesium, lithium, magnesium / copper mixtures, magnesium / silver mixtures, magnesium / aluminum mixtures, magnesium / indium mixtures, aluminum / alumina (Al₂O₃) mixtures, indium, lithium / aluminum mixtures, rare earth metals, etc. Among these, in terms of electron injection performance and durability against oxidation, mixtures of electron-injecting metals and a second metal that is stable and has a work function greater than that are suitable, such as magnesium / silver mixtures, magnesium / aluminum mixtures, magnesium / indium mixtures, aluminum / alumina (Al₂O₃) mixtures, lithium / aluminum mixtures, aluminum, etc. Cathodes can be fabricated by forming thin films from these electrode materials using methods such as vapor deposition or sputtering. Furthermore, the sheet resistance of the cathode is preferably several hundred Ω / Y or less, and the film thickness is typically selected in the range of 10 nm to 5 μm, preferably 50 nm to 200 nm. Furthermore, in order to allow the emitted light to pass through, if either the anode or cathode of the organic EL element is transparent or translucent, the luminous brightness will be increased appropriately.

[0110] Furthermore, after fabricating the cathode with a film thickness of 1 nm to 20 nm using the metal, a conductive transparent material listed in the description of fabricating the anode is then fabricated on it. This allows for the fabrication of a transparent or translucent cathode. By applying the method described above, it is possible to fabricate elements where both the anode and cathode are transmissive.

[0111] -Emitting Layer-

[0112] The light-emitting layer is a layer that emits light by generating excitons through the recombination of holes and electrons injected from the anode and cathode, respectively. The light-emitting layer contains organic light-emitting materials and host materials.

[0113] When the light-emitting layer is a fluorescent light-emitting layer, at least one fluorescent light-emitting material can be used alone, but it is preferable to use the fluorescent light-emitting material as a fluorescent light-emitting dopant and include the host material.

[0114] As a fluorescent material in the luminescent layer, azazine compounds represented by general formula (1) can be used, and from these, as is known from numerous patent documents, etc. Examples include: benzoxazole derivatives, benzothiazole derivatives, benzimidazole derivatives, styrene derivatives, polyphenyl derivatives, diphenylbutadiene derivatives, tetraphenylbutadiene derivatives, naphthalimide derivatives, coumarin derivatives, condensed aromatic compounds, perinone derivatives, oxadiazole derivatives, oxazine derivatives, aldazine derivatives, cyclopentadiene derivatives, bis(styrene)anthracene derivatives, quinacridone derivatives, pyrrolopyridine derivatives, thiadiazopyridine derivatives, styrene-amine derivatives, diketolpyrrolopyrrole derivatives, aromatic dimethylidyne compounds, metal complexes of 8-hydroxyquinoline derivatives or metal complexes of pyrrolemethylene derivatives, rare earth complexes, various metal complexes represented by transition metal complexes, polymer compounds such as polythiophene, polyphenylene, and polyphenylacetylene, and organosilanes, etc. Preferably, the compounds include condensed aromatic compounds, styryl compounds, diketylpyrrolopyrrole compounds, oxazine compounds, pyrrole methylene metal complexes, transition metal complexes, and lanthanide complexes; more preferably, the compounds include tetraphenylene, pyrene, and... (chrysene), triphenylene, benzo[c]phenanthrene, benzo[a]anthracene, pentanebenzene, perylene, fluoranthene, acenaphthofluoranthene, dibenzo[a,j]anthracene, dibenzo[a,h]anthracene, benzo[a]tetraphenyl, hexaphenyl, anthrathrene, naphtho[2,1-f]isoquinoline, α-naphtaphenanthridine, phenanthrooxazole, quinolino[6,5-f]quinoline, benzothiophanthrene, etc. These may have alkyl, aryl, aromatic heterocyclic, or diarylamino groups as substituents.

[0115] As the fluorescent host material in the luminescent layer, azazine compounds represented by general formula (1) can be used. Furthermore, as is known from numerous patent documents, etc., these can also be selected. For example, naphthalene, anthracene, phenanthrene, pyrene, etc., can be used. Compounds or their derivatives containing condensed aryl rings, such as tetraphenyl, triphenylene, perylene, fluoranthene, fluorene, and indene; aromatic amine derivatives such as N,N'-dinaphthyl-N,N'-diphenyl-4,4'-diphenyl-1,1'-diamine; metal chelated oxynoid compounds represented by tris(8-hydroxyquinoline)aluminum(III); bis(styrene) derivatives such as styreneylbenzene derivatives; tetraphenylbutadiene derivatives; indene derivatives; coumarin derivatives; oxadiazole derivatives; pyrrolopyridine derivatives; violetone derivatives; cyclopentadiene derivatives; pyrrolopyrrole derivatives; thiadiazopyridine derivatives; dibenzofuran derivatives; carbazole derivatives; indolecarbazole derivatives; triazine derivatives; and polymer systems such as polyphenylacetylene derivatives, poly(p-phenylene) derivatives, polyfluorene derivatives, polyvinylcarbazole derivatives, and polythiophene derivatives, but without particular limitation.

[0116] When the fluorescent luminescent material is used as a fluorescent luminescent dopant and includes the host material, the amount of the fluorescent luminescent dopant contained in the luminescent layer is preferably in the range of 0.01 wt% to 20 wt%, preferably 0.1 wt% to 10 wt%.

[0117] Typically, organic EL elements emit light by injecting charges into a luminescent material from both the anode and cathode electrodes, generating an excited-state luminescent material. In the case of charge-injection type organic EL elements, it can be said that 25% of the generated excitons are excited to singlet excited states, and the remaining 75% are excited to triplet excited states. As shown in *Advanced Materials*, 2009, 21, 4802-4806, the energy of a specific fluorescent luminescent material transitions to a triplet excited state through intersystem crossings, and then undergoes a reverse intersystem crossing to a singlet excited state through triplet-triple annihilation or thermal absorption, emitting fluorescence, thus exhibiting thermally activated delayed fluorescence. Delayed fluorescence can also be exhibited in the organic EL element of this invention. In this case, both fluorescent emission and delayed fluorescence emission may be included. However, the emission may also be partly or partially derived from the host material.

[0118] When the light-emitting layer is a delayed fluorescence light-emitting layer, at least one delayed light-emitting material can be used alone, but it is preferable to use the delayed fluorescence material as a delayed fluorescence light-emitting dopant and include the host material.

[0119] As a delayed fluorescence luminescent material in the luminescent layer, the azazine compound represented by general formula (1) can be used if the energy difference between the singlet and triplet energy levels is small. However, it can also be selected from known delayed fluorescence luminescent materials. Examples include tin complexes, indolocarbazole derivatives, copper complexes, carbazole derivatives, etc. Specifically, compounds described in the following non-patent literature and patent literature can be listed, but are not limited to these compounds.

[0120] 1) Advanced Materials, 2009, 21, 4802-4806; 2) Applied Physics Letters, 98, 083302 (2011); 3) Japanese Patent Application Publication No. 2011-213643; 4) Journal of the American Chemical Society, 2012, 134, 14706-14709.

[0121] Specific examples of delayed-emission materials are shown, but are not limited to the following compounds.

[0122] [Chemistry 18]

[0123]

[0124] When the delayed fluorescence luminescent material is used as a delayed fluorescence luminescent dopant and includes the host material, the amount of the delayed fluorescence luminescent dopant contained in the luminescent layer is preferably in the range of 0.01 wt% to 50 wt%, preferably 0.1 wt% to 20 wt%, and more preferably 0.01 wt% to 10 wt%.

[0125] As the host material for delayed fluorescence in the luminescent layer, azazine compounds represented by general formula (1) can be used, but other compounds can also be selected. For example, naphthalene, anthracene, phenanthrene, pyrene, etc. can be used. Compounds or their derivatives containing condensed aryl rings, such as tetraphenylene, triphenylene, perylene, fluoranthene, fluorene, and indene; aromatic amine derivatives such as N,N'-dinaphthyl-N,N'-diphenyl-4,4'-diphenyl-1,1'-diamine; metal chelated oxynoid compounds represented by tris(8-hydroxyquinoline)aluminum(III); bis(styrene) derivatives such as styreneylbenzene derivatives; tetraphenylbutadiene derivatives; indene derivatives; coumarin derivatives; oxadiazole derivatives; pyrrolopyridine derivatives; violetone derivatives; cyclopentadiene derivatives; pyrrolopyrrole derivatives; thiadiazopyridine derivatives; dibenzofuran derivatives; carbazole derivatives; indololocarbazole derivatives; triazine derivatives; and polymer systems such as polyphenylacetylene derivatives, poly(p-phenylene) derivatives, polyfluorene derivatives, polyvinylcarbazole derivatives, polythiophene derivatives, and arylsilane derivatives, but not limited to these.

[0126] When the light-emitting layer is a phosphorescent light-emitting layer, the light-emitting layer comprises a phosphorescent dopant and a host material. The phosphorescent dopant material is preferably an organometallic complex containing at least one metal selected from ruthenium, rhodium, palladium, silver, rhenium, osmium, iridium, platinum, and gold.

[0127] Preferred phosphorescent dopants include complexes such as Ir(ppy)3 with noble metal elements like Ir as the central metal, and Ir(bt). 2· Complexes such as acac3 and PtOEt3. Specific examples of these complexes are shown below, but the list is not limited to the compounds described below.

[0128] [Chemistry 19]

[0129]

[0130] The amount of phosphorescent dopant contained in the luminescent layer is preferably in the range of 2% to 40% by weight, and more preferably 5% to 30% by weight.

[0131] When the light-emitting layer is a phosphorescent light-emitting layer, the azine compound of the present invention is preferably used as the host material in the light-emitting layer. However, when the azine compound is used in any other organic layer besides the light-emitting layer, other host materials may be used. Furthermore, the compound of the present invention may be used in combination with other host materials. Moreover, a variety of known host materials may also be used in combination.

[0132] As known host compounds, compounds with hole transport capability, electron transport capability, long wavelength to prevent luminescence, and high glass transition temperature are preferred.

[0133] Other main materials are known from numerous patent documents, and therefore can be selected from these. Specific examples of main materials are not particularly limited, but can include: indole derivatives, carbazole derivatives, indole-carbazole derivatives, triazole derivatives, oxazole derivatives, oxadiazole derivatives, imidazole derivatives, polyarylalkane derivatives, pyrazoline derivatives, pyrazolineone derivatives, phenylenediamine derivatives, arylamine derivatives, amino-substituted chalcone derivatives, styrene-anthracene derivatives, fluorenone derivatives, hydrazone derivatives, stilbene derivatives, silazane derivatives, aromatic tertiary amine compounds, styrene-amine compounds, and aromatic dimethylamine compounds. Metal complexes represented by dene-based compounds, porphyrin-based compounds, anthraquinone dimethane derivatives, anthrone derivatives, diphenylquinone derivatives, thiamium dioxide derivatives, heterocyclic tetracarboxylic anhydrides of perylene, etc., phthalocyanine derivatives, metal complexes of 8-hydroxyquinoline derivatives or metal phthalocyanines, benzoxazole or benzothiazole derivatives; polysilane-based compounds, poly(N-vinylcarbazole) derivatives, aniline copolymers, thiophene oligomers, polythiophene derivatives, polyphenylene derivatives, polyphenylacetylene derivatives, polyfluorene derivatives, and other polymers.

[0134] The light-emitting layer can be any of a fluorescent light-emitting layer, a delayed fluorescent light-emitting layer, or a phosphorescent light-emitting layer, but is preferably a phosphorescent light-emitting layer.

[0135] -Injection Layer-

[0136] An injection layer is a layer placed between the electrode and the organic layer to reduce the driving voltage or increase the luminous brightness. It includes both hole injection layers and electron injection layers, and can also exist between the anode and the luminescent layer or hole transport layer, or between the cathode and the luminescent layer or electron transport layer. The injection layer can be set as needed.

[0137] -hole blocking layer-

[0138] In a broad sense, hole blocking layers function as electron transport layers. They include hole blocking materials that have the ability to transport electrons but have a significantly lower ability to transport holes. By transporting electrons and blocking holes, they can increase the probability of electron-hole recombination.

[0139] In the hole-blocking layer, the azazine compound of the present invention is preferably used. When using the compound in any other organic layer, known hole-blocking layer materials may also be used. Alternatively, electron transport layer materials described later may be used as the hole-blocking layer material, depending on the need.

[0140] -Electron blocking layer-

[0141] Electron blocking layers contain materials that have the ability to transport holes but have a significantly lower ability to transport electrons. They can increase the probability of electron-hole recombination by transporting holes and blocking electrons.

[0142] The electron blocking layer material can be any material described later, as needed, used for the hole transport layer. The thickness of the electron blocking layer is preferably 3 nm to 100 nm, more preferably 5 nm to 30 nm.

[0143] -Exciton blocking layer-

[0144] An exciton blocking layer is used to prevent excitons generated in the light-emitting layer due to the recombination of holes and electrons from diffusing into the charge transport layer. By inserting this layer, excitons can be efficiently sealed within the light-emitting layer, thereby improving the luminous efficiency of the device. The exciton blocking layer can be inserted adjacent to the light-emitting layer on either the anode or cathode side, or simultaneously on both sides.

[0145] As the material for the exciton blocking layer, materials for the hole transport layer or the electron transport layer described later may be used as needed. Alternatively, azazine compounds represented by general formula (1) may be used as other materials, such as 1,3-dicarbazolylbenzene (mCP) or bis(2-methyl-8-hydroxyquinoline)-4-phenylphenolaluminum(III) (BAlq).

[0146] -Hole transport layer-

[0147] The hole transport layer contains hole transport material with the function of transporting holes, and the hole transport layer can be a single layer or multiple layers.

[0148] Hole transport materials are materials that possess either hole injection or transport or electron barrier properties, and can be either organic or inorganic. Any of these can be selected from known hole transport materials that are currently usable. Examples of known hole transport materials that are currently usable include triazole derivatives, oxadiazole derivatives, imidazole derivatives, polyaryl alkane derivatives, pyrazoline derivatives and pyrazolineone derivatives, phenylenediamine derivatives, arylamine derivatives, amino-substituted chalcone derivatives, oxazole derivatives, styrene-anthracene derivatives, fluorenone derivatives, hydrazone derivatives, stilbene derivatives, silazane derivatives, aniline copolymers, and conductive polymeric oligomers, particularly thiophene oligomers. Porphyrin compounds, aromatic tertiary amine compounds, and styrene-based amine compounds are preferred, and aromatic tertiary amine compounds are more preferred. Additionally, azazine compounds represented by general formula (1) can be used as hole transport materials.

[0149] -Electron transport layer-

[0150] The electron transport layer contains materials that can transport electrons, and the electron transport layer can be a single layer or multiple layers.

[0151] As an electron transport material (and sometimes a hole-blocking material), it is sufficient to have the function of transporting electrons injected from the cathode to the light-emitting layer. The azazine compound of the present invention can also be used in the electron transport layer, but any known compound can be selected, such as nitro-substituted fluorene derivatives, diphenylquinone derivatives, thiamethane dioxide derivatives, carbodiimides, fluorenemethane derivatives, anthraquinone dimethane and anthrone derivatives, oxadiazole derivatives, etc. Furthermore, among the oxadiazole derivatives, thiadiazole derivatives formed by replacing the oxygen atom of the oxadiazole ring with a sulfur atom, and quinoxaline derivatives having a quinoxaline ring known to have an electron-withdrawing group, can also be used as electron transport materials. Furthermore, polymer materials incorporating these materials into polymer chains or using these materials as the backbone of polymers can also be used. Moreover, the difference in electron affinity (EA) between the electron transport material (including those also acting as hole-blocking materials) and the organic light-emitting dopant material or host is preferably 0.3 eV.

[0152] Example

[0153] The present invention will be described in more detail below through embodiments, but the present invention is not limited to these embodiments and can be implemented in various ways as long as it does not depart from its spirit.

[0154] Azazine compounds, which are used as materials for organic electric field light-emitting elements, are synthesized via the pathway shown below. Furthermore, the compound numbers correspond to the numbers designated in the chemical formulas described.

[0155] Example 1

[0156] Compounds 1-6 are synthesized according to the following reaction formula.

[0157] [Chemistry 20]

[0158]

[0159] Under nitrogen atmosphere, 12.0 g (23.0 mmol) of intermediate (B), 10.0 g (23.0 mmol) of intermediate (C), 1.33 g (1.15 mmol) of catalyst A, 15.0 g of cesium carbonate, and 200 ml of N,N'-dimethylacetamide (DMA) were added, and the mixture was heated at 130 °C with stirring for 30 minutes. After cooling to room temperature, the reaction solution was added to a mixture of methanol (400 ml) and distilled water (400 ml) with stirring, and the resulting precipitated solid was collected by filtration. The obtained solid was purified by silica gel column chromatography and crystallization to obtain 8.1 g (10.2 mmol, yield 44.1%) of compounds 1-6 as a yellow solid (Atmospheric Pressure Chemical Ionization Time-of-Flight Mass Spectrometry (APCI-TOFMS), m / z 796 [M+H)). + ).

[0160] Here, catalyst A is tetrakis(triphenylphosphine)palladium(0), and DMA is N,N'-dimethylacetamide.

[0161] Example 2

[0162] Compounds 1-7 were synthesized according to the following reaction formula.

[0163] [Chemistry 21]

[0164]

[0165] Under nitrogen atmosphere, 3.1 g (4.5 mmol) of intermediate (D), 1.15 g (4.95 mmol) of 2-bromo-6-phenylpyridine, 0.26 g (0.22 mmol) of catalyst A, 2.93 g of cesium carbonate, and 50 mL of 1,4-dioxane were added, and the mixture was heated and stirred at 120 °C for 2 hours. After cooling to room temperature, the reaction solution was added to a mixture of methanol (150 mL) and distilled water (100 mL) while stirring. The obtained precipitated solid was filtered off. The obtained solid was purified in the same manner as in Example 1 to obtain 2.3 g (3.2 mmol, 71.1% yield) of compounds 1-7 as a pale yellow solid (APCI-TOFMS, m / z 717 [M+H]). + ).

[0166] Example 3

[0167] Compounds 1-16 were synthesized according to the following reaction formula.

[0168] [Chemistry 22]

[0169]

[0170] Under nitrogen atmosphere, 7.0 g (16.1 mmol) of intermediate (C), 9.6 g (16.1 mmol) of intermediate (E), 0.47 g (0.40 mmol) of catalyst A, 10.5 g of cesium carbonate, and 200 ml of DMA were added, and the mixture was heated and stirred overnight at 120 °C. After cooling to room temperature, the reaction solution was added to a mixture of methanol (400 ml) and distilled water (240 ml) while stirring, and the resulting precipitated solid was collected by filtration. The obtained solid was purified in the same manner as in Example 1, yielding 5.7 g (6.55 mmol, 40.7% yield) of compound 1-16 as a yellow solid (APCI-TOFMS, m / z 871 [M+H]). + ).

[0171] Example 4

[0172] Compound 1-137 was synthesized according to the following reaction formula.

[0173] [Chemistry 23]

[0174]

[0175] Under nitrogen atmosphere, 9.0 g (13.0 mmol) of intermediate (D), 4.0 g (14.3 mmol) of intermediate (F), 0.75 g (0.65 mmol) of catalyst A, 8.5 g of cesium carbonate, and 50 ml of DMA were added, and the mixture was heated and stirred at 120 °C for 4 hours. After cooling to room temperature, the reaction solution was added to a mixture of methanol (400 ml) and distilled water (240 ml) while stirring. The obtained precipitated solid was filtered off. The obtained solid was purified in the same manner as in Example 1, yielding 7.2 g (8.9 mmol, 68.5% yield) of compound 1-137 (APCI-TOFMS, m / z 806 [M+H]) as a pale yellow solid. + ).

[0176] According to the synthesis examples described above, in addition to synthesizing compounds 1-6, 1-7, 1-16, and 1-137, compounds 1-1, 1-5, 1-12, 1-27, 1-28, and 1-198 were also synthesized. Furthermore, compounds H-1, H-2, H-3, and H-4 were synthesized for comparison.

[0177] [Chemistry 24]

[0178]

[0179] The measured values ​​of ionization potential (IP) in this specification can be obtained by photoelectron spectroscopy in the host material thin film. The measured values ​​of electron affinity (EA) can be calculated using the values ​​of ionization potential and band gap, which are determined by measuring the absorption spectrum and based on its absorption end.

[0180] Table 1 shows the absolute values ​​of electron affinity (EA) and ionization potential (IP) for compounds 1-6, 1-7, 1-16, 1-137, H-1, H-2, H-3, and H-4.

[0181] [Table 1]

[0182] compound EA(eV) IP(eV) 1-6 2.9 6.0 1-7 2.9 6.0 1-12 3.0 6.0 1-16 2.8 5.9 1-137 3.0 6.0 H-1 2.9 6.3 H-2 3.0 6.3 H-3 2.7 5.9 H-4 2.6 5.9

[0183] Example 5

[0184] On a glass substrate with an ITO-containing anode having a film thickness of 110 nm, a vacuum evaporation method was used to deposit the film at a vacuum degree of 4.0 × 10⁻⁶. -5 Pa is used to stack various thin films. First, CuPc is formed on ITO with a thickness of 25 nm as a hole injection layer, and then NPD is formed on ITO with a thickness of 30 nm as a hole transport layer. Next, HT-1 is formed on ITO with a thickness of 10 nm as an electron blocking layer. Then, compound 1-1 as the host material and Ir(ppy)3 as the light-emitting dopant are co-deposited from different evaporation sources to form a light-emitting layer with a thickness of 40 nm. At this time, the concentration of Ir(ppy)3 is 10 wt%. Next, compound H-3 is formed on ITO with a thickness of 10 nm as a hole blocking layer. Next, ET-1 is formed on ITO with a thickness of 10 nm as an electron transport layer. Next, LiF is formed on the electron transport layer with a thickness of 1 nm as an electron injection layer. Finally, Al is formed on the electron injection layer with a thickness of 70 nm as a cathode, thereby fabricating an organic EL device.

[0185] When an external power supply was connected to the obtained organic EL element and a DC voltage was applied, a emission spectrum with a maximum wavelength of 517 nm was observed, indicating that emission from Ir(ppy)3 was obtained.

[0186] Examples 6 to 14

[0187] Except that compounds 1-5, 1-6, 1-7, 1-12, 1-16, 1-27, 1-28, 1-137, and 1-198 were used instead of compound 1-1 as the host material for the luminescent layer in Example 5, an organic EL element was fabricated in the same manner as in Example 5. An external power supply was connected to the obtained organic EL element and a DC voltage was applied, resulting in the observation of a emission spectrum with a maximum wavelength of 517 nm.

[0188] Comparative Examples 1 to 2

[0189] Except for using compounds H-1 and H-3 as the main materials for the luminescent layer in Example 5, an organic EL element was fabricated in the same manner as in Example 5. An external power supply was connected to the obtained organic EL element and a DC voltage was applied, resulting in the observation of a emission spectrum with a maximum wavelength of 517 nm.

[0190] The evaluation results of the fabricated organic EL elements are shown in Table 2. In the table, brightness, driving voltage, and luminous efficiency are calculated based on a driving current of 20 mA / cm². 2 The value at time represents the initial characteristics. LT70 is the time required for the brightness to decay to 70% of its initial value, representing the lifetime characteristics.

[0191] [Table 2]

[0192]

[0193] Example 15

[0194] On a glass substrate with an ITO-containing anode having a film thickness of 110 nm, a vacuum evaporation method was used to deposit the film at a vacuum degree of 4.0 × 10⁻⁶. -5Pa is used to stack various thin films. First, CuPc is formed on ITO with a thickness of 25 nm as a hole injection layer, followed by NPD with a thickness of 45 nm as a hole transport layer. Then, HT-1 is formed with a thickness of 10 nm as an electron blocking layer. Next, compound 1-1 as the host material and Ir(piq)2acac as a dopant are co-deposited from different evaporation sources to form a light-emitting layer with a thickness of 40 nm. At this time, the concentration of Ir(piq)2acac is 6.0 wt%. Then, compound H-3 is formed with a thickness of 10 nm as a hole blocking layer. Next, ET-1 is formed with a thickness of 27.5 nm as an electron transport layer. Then, LiF is formed on the electron transport layer with a thickness of 1 nm as an electron injection layer. Finally, Al is formed on the electron injection layer with a thickness of 70 nm as a cathode, thereby fabricating an organic EL device. When an external power supply was connected to the obtained organic EL element and a DC voltage was applied, a emission spectrum with a maximum wavelength of 620 nm was observed, indicating that emission from Ir(piq)2acac was obtained.

[0195] Examples 16 to 24

[0196] Organic EL elements were fabricated in the same manner as in Example 15, except that compounds 1-5, 1-6, 1-7, 1-12, 1-16, 1-27, 1-28, 1-137, and 1-198 were used instead of compound 1-1 as the host material for the luminescent layer in Example 15. A DC voltage was applied to the obtained organic EL element, and a emission spectrum with a maximum wavelength of 620 nm was observed.

[0197] Comparative Examples 3 to 5

[0198] Except that compounds H-1, H-2, and H-3 were used as the host materials for the luminescent layer in Example 15, an organic EL element was fabricated in the same manner as in Example 15. A DC voltage was applied to the obtained organic EL element, and a emission spectrum with a maximum wavelength of 620 nm was observed.

[0199] The evaluation results of the fabricated organic EL elements are shown in Table 3. The evaluation conditions were the same as in Examples 5 to 14, and LT90 was the time required for the brightness to decay to 90% of the initial brightness.

[0200] [Table 3]

[0201]

[0202] As can be seen from Tables 2 and 3, the power efficiency and lifespan characteristics of Examples 5 to 24 are improved, and they exhibit good performance.

[0203] Example 25

[0204] On a glass substrate with an ITO-containing anode having a film thickness of 110 nm, a vacuum evaporation method was used to deposit the film at a vacuum degree of 4.0 × 10⁻⁶. -5 Pa is used to stack various thin films. First, CuPc is formed on ITO with a thickness of 25 nm as a hole injection layer, followed by NPD with a thickness of 30 nm as a hole transport layer. Next, HT-1 is formed with a thickness of 10 nm as an electron blocking layer. Then, compound H-1 as the host material and Ir(ppy)3 as the light-emitting dopant are co-deposited from different evaporation sources to form a light-emitting layer with a thickness of 40 nm. At this time, the concentration of Ir(ppy)3 is 10 wt%. Next, compound 1-1 is formed with a thickness of 5 nm as a hole blocking layer. Next, ET-1 is formed with a thickness of 15 nm as an electron transport layer. Then, LiF is formed on the electron transport layer with a thickness of 1 nm as an electron injection layer. Finally, Al is formed on the electron injection layer with a thickness of 70 nm as a cathode, thereby fabricating an organic EL device.

[0205] Examples 26 to 34

[0206] Organic EL elements were fabricated in the same manner as in Example 25, except that compounds 1-5, 1-6, 1-7, 1-12, 1-16, 1-27, 1-28, 1-137, and 1-198 were used in place of compound 1-1 as the hole blocking layer in Example 25.

[0207] Example 35

[0208] The organic EL element was fabricated in the same manner as in Example 25, except that compound 1-1 was used instead of compound H-1 as the main material of the light-emitting layer.

[0209] Comparative Examples 6-7

[0210] Organic EL elements were fabricated in the same manner as in Example 25, except that compounds H-1 and H-3 were used as hole blocking layers.

[0211] The evaluation results of the fabricated organic EL elements are shown in Table 4.

[0212] [Table 4]

[0213]

[0214] The compounds used in the examples are shown below.

[0215] [Chemistry 25]

[0216]

Claims

1. A material for an organic electric field light-emitting element, comprising a compound represented by any one of general formulas (3) to (8); Here, R independently represents hydrogen or deuterium; R 15 It refers to a substituted or unsubstituted aromatic hydrocarbon group with 6 carbon atoms, or a substituted or unsubstituted linked aromatic group formed by two linked aromatic rings of such hydrocarbons; Ar 2 Independently represented by the aromatic heterocyclic group of formula (1b), Ar 3 Independently representing an aromatic hydrocarbon group having 6 to 30 carbon atoms, a substituted or unsubstituted aromatic heterocyclic group having 3 to 16 carbon atoms, or a substituted or unsubstituted linked aromatic group consisting of 2 to 5 of these aromatic rings. Y independently represents N or CR 14 At least one of them is N; R 14 Independently represents hydrogen, deuterium, or a substituted or unsubstituted aromatic hydrocarbon group with 6 carbon atoms; L 1 Indicates substituted or unsubstituted phenylene; Here, when the aromatic hydrocarbon group, the aromatic heterocyclic group, or the linked aromatic cyclic group has a substituent, the substituent is selected from any one of the group consisting of alkyl with 1 to 5 carbon atoms, alkenyl with 2 to 5 carbon atoms, alkoxy with 1 to 5 carbon atoms, deuterium, halogen, amino, and cyano.

2. The material for organic electric field light-emitting elements according to claim 1, wherein, L 1 The phenylene is represented by formula (1c) or formula (1d) below; 。 3. The material for organic electric field light-emitting elements according to claim 1, comprising a compound represented by any one of general formulas (3) to (5).

4. The material for organic electric field light-emitting elements according to claim 1, characterized in that, The compounds represented by any of the general formulas (3) to (5) have an absolute value of electron affinity greater than 2.6 eV and an absolute value of ionization potential less than 6.1 eV.

5. An organic electric field light-emitting element, characterized in that, It is formed by stacking an anode, an organic layer and a cathode on a substrate, wherein at least one of the organic layers is an organic layer containing the material for an organic electric field light-emitting element as described in any one of claims 1 to 4.

6. The organic electric field light-emitting element according to claim 5, wherein, The organic layer containing the material for the organic electric field light-emitting element is at least one layer selected from the group consisting of a light-emitting layer, an electron transport layer, and a hole blocking layer.

7. The organic electric field light-emitting element according to claim 5, wherein, The organic layer containing the material used in the organic electric field light-emitting element is the light-emitting layer.

8. The organic electric field light-emitting element according to claim 7, characterized in that, The light-emitting layer comprises a host and a light-emitting dopant material, which is an organometallic complex comprising at least one metal selected from the group consisting of ruthenium, rhodium, palladium, silver, rhenium, osmium, iridium, platinum and gold.

9. The organic electric field light-emitting element according to claim 7, characterized in that, The luminescent layer comprises a host and a luminescent dopant material, which is a thermally activated delayed fluorescence luminescent dopant material.

10. The organic electric field light-emitting element according to claim 5, characterized in that, A hole blocking layer is disposed adjacent to the light-emitting layer, and the hole blocking layer contains the material for the organic electric field light-emitting element.

11. A material for an organic electric field light-emitting element, characterized in that, It includes any one of the following compounds: 1-1, 1-7, 1-13, 1-14, 1-22, 1-28, 1-34, 1-35, 1-42, 1-48, 1-54, 1-55, 1-62, 1-68, 1-74, 1-75, 1-82, 1-88, 1-94, 1-95, 1-102, 1-108, 1-114, 1-115, 1-122, 1-128, 1-130, 1-137, 1-139, 1-165, 1-199; 。 12. The material for an organic electric field light-emitting element according to claim 11, characterized in that, The compound has an absolute value of electron affinity greater than 2.6 eV and an absolute value of ionization potential less than 6.1 eV.

13. An organic electric field light-emitting element, characterized in that, It is formed by stacking an anode, an organic layer and a cathode on a substrate, wherein at least one of the organic layers is an organic layer containing the material for an organic electric field light-emitting element as described in claim 11.

14. The organic electric field light-emitting element according to claim 13, wherein, The organic layer containing the material for the organic electric field light-emitting element is at least one layer selected from the group consisting of a light-emitting layer, an electron transport layer, and a hole blocking layer.

15. The organic electric field light-emitting element according to claim 13, wherein, The organic layer containing the material used in the organic electric field light-emitting element is the light-emitting layer.

16. The organic electric field light-emitting element according to claim 15, characterized in that, The light-emitting layer comprises a host and a light-emitting dopant material, which is an organometallic complex comprising at least one metal selected from the group consisting of ruthenium, rhodium, palladium, silver, rhenium, osmium, iridium, platinum and gold.

17. The organic electric field light-emitting element according to claim 15, characterized in that, The luminescent layer comprises a host and a luminescent dopant material, which is a thermally activated delayed fluorescence luminescent dopant material.

18. The organic electric field light-emitting element according to claim 15, characterized in that, A hole blocking layer is disposed adjacent to the light-emitting layer, and the hole blocking layer contains the material for the organic electric field light-emitting element.

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