Boron-containing compound, light-emitting material, and light-emitting element using same

Abstract

The present invention relates to a compound represented by formula (I), a light-emitting material containing the compound, and a light-emitting element containing the light-emitting material. (In the formula, R1 is a C1-4 alkyl group or the like, A1 and A2 are each independently a group represented by formula (II) (R2 and R3 are each independently a hydrogen atom, C1-4 alkyl group or the like, and * is a bonding moiety) or the like. # imgabs0 #

Description

Technical Field

[0001] The present invention relates to a boron-containing compound, a light-emitting material, and a light-emitting element using the same. More specifically, the present invention relates to a boron-containing compound, a light-emitting material, and a light-emitting element using the same having excellent light-emitting properties.

[0002] This application claims priority based on Japanese Patent Application No. 2022-130784 filed in Japan on August 18, 2022, and uses the contents thereof herein. Background Art

[0003] As a boron-containing compound having luminescence, for example, Patent Document 1 proposes the following boron-containing compound.

[0004]

[0005]

[0006] Prior art literature

[0007] Patent Literature

[0008] Patent document 1: US2020 / 0185635A1 Summary of the invention

[0009] An object of the present invention is to provide a novel boron-containing compound having excellent light-emitting properties, a light-emitting material, and a light-emitting element using the light-emitting material.

[0010] In order to solve the above-mentioned problems, the inventors have conducted intensive studies and, as a result, have completed the present invention including the following aspects.

[0011] That is, the present invention is as follows:

[0012] [1] A compound represented by formula (I).

[0013]

[0014] In formula (I),

[0015] R 1 is C1-4 alkyl, substituted or unsubstituted phenyl, substituted or unsubstituted naphthyl, substituted or unsubstituted anthracenyl, or substituted or unsubstituted phenanthrenyl,

[0016] A 1 and A 2 are each independently a group represented by formula (II), a group represented by formula (III), a group represented by formula (IV), a group represented by formula (V), a group represented by formula (VI), a group represented by formula (VII), a group represented by formula (VIII) or a group represented by formula (IX),

[0017]

[0018]

[0019]

[0020] In the above formula (II), formula (III), formula (IV), formula (V), formula (VI), formula (VII), formula (VIII) and formula (IX), R 2 and R 3 are each independently a hydrogen atom, a C1-4 alkyl group, or a substituted or unsubstituted phenyl group,

[0021] * is the bonding part.

[0022] [2] The compound according to [1], wherein in the above formula (II), formula (III), formula (IV), formula (V), formula (VI), formula (VII), formula (VIII) and formula (IX), R 2 and R 3 Each is independently a hydrogen atom or a tert-butyl group.

[0023] [3] A light-emitting material comprising the compound described in [1] or [2].

[0024] [4] A light-emitting element comprising the light-emitting material described in [3].

[0025] The boron-containing compound of the present invention is useful as a light-emitting material. The light-emitting material of the present invention emits delayed fluorescence. A light-emitting element containing the light-emitting material of the present invention can achieve excellent light-emitting efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a diagram showing the results of the absorption spectrum measured in Test Example 1.

[0027] Figure 2 This is a diagram showing the results of PL spectra measured in Experimental Example 1.

[0028] Figure 3 This is a graph showing the results of transient TRPL characteristics measured in Test Example 1.

[0029] Figure 4 This is a diagram showing the results of PL spectra measured in Experimental Example 2.

[0030] Figure 5 This is a graph showing the results of transient TRPL characteristics measured in Test Example 2.

[0031] Figure 6 This is a diagram showing the results of EL spectrum measured in Test Example 3.

[0032] Figure 7 This is a graph showing the results of the voltage-current density-luminance characteristics measured in Test Example 3.

[0033] Figure 8 This is a graph showing the results of measuring the luminance-external quantum efficiency characteristics of the light-emitting element in Test Example 3. DETAILED DESCRIPTION

[0034] The boron-containing compound contained in the light-emitting material of the present invention is a compound represented by formula (I).

[0035]

[0036] In the present invention, the term "unsubstituted" refers to a group that only serves as a parent nucleus. When "substituted" is not mentioned but only the name of the group that serves as a parent nucleus is mentioned, it means "unsubstituted" unless otherwise specified.

[0037] On the other hand, the term "substituted" means that any hydrogen atom in the group that becomes the parent nucleus is replaced by a group (substituent) with the same or different structure as the parent nucleus. Therefore, a "substituent" is another group bonded to the group that becomes the parent nucleus. The substituent can be 1 or more than 2. More than 2 substituents can be the same or different.

[0038] For example, the term "C1-6" means that the number of carbon atoms of the group that becomes the parent core is 1 to 6. This number of carbon atoms does not include the number of carbon atoms present in the substituent. For example, a butyl group having an ethoxy group as a substituent is classified as a C2 alkoxy C4 alkyl group.

[0039] The "substituent" is not particularly limited as long as it is chemically acceptable and has the effects of the present invention.

[0040] The following are examples of groups that can serve as a "substituent".

[0041] C1-6 alkyl groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, n-pentyl, and n-hexyl;

[0042] C2-6 alkenyl groups such as vinyl, 1-propenyl, 2-propenyl (allyl), 1-butenyl, 2-butenyl, 3-butenyl, 1-methyl-2-propenyl, and 2-methyl-2-propenyl;

[0043] C2-6 alkynyl groups such as ethynyl, 1-propynyl, 2-propynyl, 1-butynyl, 2-butynyl, 3-butynyl, and 1-methyl-2-propynyl;

[0044] C3-6 cycloalkyl groups such as cyclopropyl, cyclobutyl, cyclopentyl, and cyclohexyl;

[0045] Aryl groups such as phenyl, tolyl, xylyl, trimethylphenyl, and naphthyl;

[0046] Benzyl, phenethyl and other phenyl C1-6 alkyl groups;

[0047] Three to six-membered heterocyclic group;

[0048] Three to six-membered heterocyclic C1-6 alkyl;

[0049] Hydroxyl;

[0050] C1-6 alkoxy groups such as methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, sec-butoxy, isobutoxy and tert-butoxy;

[0051] C2-6 alkenyloxy groups such as vinyloxy, allyloxy, propyleneoxy, and butenyloxy;

[0052] C2-6 alkynyloxy groups such as ethynyloxy and propynyloxy;

[0053] Phenoxy, naphthoxy;

[0054] Benzyloxy, phenethoxy and other phenyl C1-6 alkoxy groups;

[0055] Thiazolyloxy, pyridyloxy and other five- to six-membered heteroaryloxy groups;

[0056] Thiazolylmethoxy, pyridylmethoxy and other five- to six-membered heteroaryl C1-6 alkoxy groups;

[0057] Formyl;

[0058] C1-6 alkylcarbonyl such as acetyl and propionyl;

[0059] Formyloxy;

[0060] C1-6 alkylcarbonyloxy groups such as acetoxy and propionyloxy;

[0061] Benzoyl;

[0062] C1-6 alkoxycarbonyl such as methoxycarbonyl, ethoxycarbonyl, n-propoxycarbonyl, isopropoxycarbonyl, n-butoxycarbonyl, tert-butoxycarbonyl;

[0063] C1-6 alkoxycarbonyloxy groups such as methoxycarbonyloxy, ethoxycarbonyloxy, n-propoxycarbonyloxy, isopropoxycarbonyloxy, n-butoxycarbonyloxy and tert-butoxycarbonyloxy;

[0064] carboxyl;

[0065] Halogen groups such as fluorine, chlorine, bromine, and iodine;

[0066] C1-6 haloalkyl groups such as chloromethyl, chloroethyl, trifluoromethyl, 1,2-dichloro-n-propyl, 1-fluoro-n-butyl, and perfluoro-n-pentyl;

[0067] C2-6 haloalkenyl such as 2-chloro-1-propenyl and 2-fluoro-1-butenyl;

[0068] C2-6 haloalkynyl such as 4,4-dichloro-1-butynyl, 4-fluoro-1-pentynyl and 5-bromo-2-pentynyl;

[0069] C1-6 haloalkoxy such as trifluoromethoxy, 2-chloro-n-propoxy, 2,3-dichlorobutoxy;

[0070] C2-6 haloalkenyloxy groups such as 2-chloropropenyloxy and 3-bromobutenyloxy;

[0071] C1-6 haloalkylcarbonyl such as chloroacetyl, trifluoroacetyl, trichloroacetyl;

[0072] Amino;

[0073] C1-6 alkyl-substituted amino groups such as methylamino, dimethylamino and diethylamino;

[0074] Phenylamino, naphthylamino;

[0075] Phenyl C1-6 alkylamino groups such as benzylamino and phenethylamino;

[0076] Formylamino;

[0077] C1-6 alkylcarbonylamino groups such as acetylamino, propionylamino, butyrylamino and isopropylcarbonylamino;

[0078] C1-6 alkoxycarbonylamino such as methoxycarbonylamino, ethoxycarbonylamino, n-propoxycarbonylamino and isopropoxycarbonylamino;

[0079] unsubstituted or substituted aminocarbonyl such as aminocarbonyl, dimethylaminocarbonyl, phenylaminocarbonyl and N-phenyl-N-methylaminocarbonyl;

[0080] Imino C1-6 alkyl groups such as iminomethyl, (1-imino)ethyl, (1-imino)-n-propyl;

[0081] Substituted or unsubstituted N-hydroxyimino C1-6 alkyl groups such as N-hydroxy-iminomethyl, (1-(N-hydroxy)-imino)ethyl, (1-(N-hydroxy)-imino)propyl, N-methoxy-iminomethyl, (1-(N-methoxy)-imino)ethyl;

[0082] aminocarbonyloxy;

[0083] C1-6 alkyl-substituted aminocarbonyloxy such as ethylaminocarbonyloxy and dimethylaminocarbonyloxy;

[0084] thiol;

[0085] C1-6 alkylthio groups such as methylthio, ethylthio, n-propylthio, isopropylthio, n-butylthio, isobutylthio, sec-butylthio, and tert-butylthio;

[0086] C1-6 halogenated alkylthio groups such as trifluoromethylthio and 2,2,2-trifluoroethylthio;

[0087] Phenylthio, naphthylthio;

[0088] Thiazolethio, pyridinylthio and other five- to six-membered heteroarylthio groups;

[0089] C1-6 alkylsulfinyl groups such as methylsulfinyl, ethylsulfinyl and tert-butylsulfinyl;

[0090] C1-6 haloalkylsulfinyl groups such as trifluoromethylsulfinyl and 2,2,2-trifluoroethylsulfinyl;

[0091] phenylsulfinyl;

[0092] Thiazolylsulfinyl, pyridylsulfinyl and other five- to six-membered heteroarylsulfinyl groups;

[0093] C1-6 alkylsulfonyl groups such as methylsulfonyl, ethylsulfonyl and tert-butylsulfonyl;

[0094] C1-6 halogenated alkylsulfonyl groups such as trifluoromethylsulfonyl and 2,2,2-trifluoroethylsulfonyl;

[0095] Phenylsulfonyl;

[0096] Thiazolylsulfonyl, pyridylsulfonyl and other five- to six-membered heteroarylsulfonyl groups;

[0097] C1-6 alkylsulfonyloxy groups such as methylsulfonyloxy, ethylsulfonyloxy and tert-butylsulfonyloxy;

[0098] C1-6 haloalkylsulfonyloxy groups such as trifluoromethylsulfonyloxy and 2,2,2-trifluoroethylsulfonyloxy;

[0099] Trimethylsilyl, triethylsilyl, tert-butyldimethylsilyl and other C1-6 alkyl-substituted silyl groups;

[0100] triphenylsilyl;

[0101] Cyano; nitro.

[0102] In addition, these "substituents" may replace any hydrogen atom in the substituent with a group of a different structure. Examples of the "substituent" in this case include C1-6 alkyl, C1-6 haloalkyl, C1-6 alkoxy, C1-6 haloalkoxy, halogen group, cyano, nitro, etc.

[0103] In addition, the above-mentioned "three to six-membered heterocyclic group" refers to a group containing 1 to 4 heteroatoms selected from nitrogen atoms, oxygen atoms and sulfur atoms as constituent atoms of the ring. The heterocyclic group may be any of a monocyclic ring and a polycyclic ring. As for the polycyclic heterocyclic group, as long as at least one ring is a heterocyclic ring, the remaining rings may be any of a saturated alicyclic ring, an unsaturated alicyclic ring or an aromatic ring. As the "three to six-membered heterocyclic group", there can be mentioned a three to six-membered saturated heterocyclic group, a five to six-membered heteroaryl group, a five to six-membered partially unsaturated heterocyclic group, and the like.

[0104] Examples of the "three- to six-membered saturated heterocyclic group" include aziridinyl, epoxy, pyrrolidinyl, tetrahydrofuranyl, thiazolidinyl, piperidinyl, piperazinyl, morpholinyl, dioxolanyl, dimethoxyl, dimethoxycarbonyl ... Alkyl, etc.

[0105] Examples of the "five-membered heteroaryl group" include pyrrolyl, furyl, thienyl, imidazolyl, pyrazolyl, Azolyl, iso Azolyl, thiazolyl, isothiazolyl, triazolyl, oxadiazolyl, thiadiazolyl, tetrazolyl and the like.

[0106] Examples of the "six-membered heteroaryl group" include a pyridyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, and a triazinyl group.

[0107] Examples of the "five- to six-membered partially unsaturated heterocyclic group" include pyrrolinyl, dihydrofuranyl, dihydrothiophenyl, imidazolinyl, pyrazolinyl, Oxazoline, iso oxazolinyl, thiazolinyl, isothiazolinyl and other five-membered partially unsaturated heterocyclic groups; dihydropyranyl and other six-membered partially unsaturated heterocyclic groups.

[0108] In formula (I), R 1 It is C1-4 alkyl, substituted or unsubstituted phenyl, substituted or unsubstituted naphthyl, substituted or unsubstituted anthracenyl or substituted or unsubstituted phenanthrenyl.

[0109] R 1 The "C1-4 alkyl" in the formula may be a straight chain or a branched chain. 1 The "C1-4 alkyl" in the above-mentioned group includes methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl and tert-butyl.

[0110] R 1The "naphthyl" in R may be either 1-naphthyl or 2-naphthyl. 1 The "anthracenyl" in R may be any one of 1-anthracenyl, 2-anthracenyl or 9-anthracenyl. 1 The "phenanthryl" in the above formula may be any one of 1-phenanthryl, 2-phenanthryl, 3-phenanthryl, 4-phenanthryl or 9-phenanthryl.

[0111] As R 1 Preferred substituents on the "phenyl", "naphthyl", "anthryl" and "phenanthryl" in the group include alkyl groups such as methyl, ethyl and tert-butyl; aryl groups such as phenyl, tolyl, xylyl, naphthyl, anthracenyl and phenanthryl; N-arylamino groups such as N-phenylamino and N-tert-butylphenylamino. The phenyl-substituted phenyl group is a biphenyl group. The biphenyl group may be any of 2-biphenyl, 3-biphenyl and 4-biphenyl.

[0112] Among them, R 1 It is preferably a C1-4 alkyl group, and more preferably a methyl group.

[0113] In formula (I), A 1 and A 2 Each is independently a group represented by formula (II), a group represented by formula (III), a group represented by formula (IV), a group represented by formula (V), a group represented by formula (VI), a group represented by formula (VII), a group represented by formula (VIII) or a group represented by formula (IX), preferably a group represented by formula (II), a group represented by formula (III) or a group represented by formula (IV), A 1 and A 2 More preferably, they represent the same group.

[0114]

[0115]

[0116]

[0117] In formula (II), formula (III), formula (IV), formula (V), formula (VI), formula (VII), formula (VIII) and formula (IX), R 2 and R 3 Each is independently a hydrogen atom, a C1-4 alkyl group or a substituted or unsubstituted phenyl group, preferably a hydrogen atom or a C1-4 alkyl group, more preferably a hydrogen atom or a tert-butyl group.

[0118] In formula (II), formula (III), formula (IV), formula (V), formula (VI), formula (VII), formula (VIII) and formula (IX), * is a bonding portion.

[0119] Examples of the group represented by formula (II), formula (III), formula (IV), formula (V), formula (VI), formula (VII), formula (VIII) or formula (IX) include N,N-diphenylaminobenzene-3,4-diyl, N,N-bis(4-C1~4 alkylphenyl)aminobenzene-3,4-diyl, N-(4-C1~4 alkylphenyl)-N-phenyl-aminobenzene-3,4-diyl; 9-phenyl-9H-carbazole-2,3-diyl, 9-(4-C1~4 alkylphenyl)- phenyl)-6-C1~4 alkyl-9H-carbazole-2,3-diyl; 9-phenyl-9H-carbazole-3,4-diyl, 9-(4-C1~4 alkylphenyl)-6-C1~4 alkyl-9H-carbazole-3,4-diyl; 4-(9H-carbazole-9-yl)benzene-3,4-diyl, 4-(3,6-diC1~4 alkyl-9H-carbazole-9-yl)benzene-3,4-diyl, 4-(3-C1~4 alkyl-9H-carbazole-9-yl)benzene-3,4-diyl, etc.

[0120] R 2 or R 3 The "C1-4 alkyl" in the formula may be a straight chain or a branched chain. 1 The "C1-4 alkyl" in the above-mentioned group includes methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl and tert-butyl.

[0121] As R 2 or R 3 Preferred substituents on the "phenyl" in the formula include alkyl groups such as methyl, ethyl, and tert-butyl; aryl groups such as phenyl, tolyl, xylyl, naphthyl, anthracenyl, and phenanthryl; and N-arylamino groups such as N-phenylamino and N-tert-butylphenylamino. The phenyl-substituted phenyl group is a biphenyl group. The biphenyl group may be any of 2-biphenyl, 3-biphenyl, and 4-biphenyl.

[0122] Specific examples of the boron-containing compound of the present invention include the following compounds, among which compounds represented by the following formula (I-1), (I-6) or (I-7) are preferred.

[0123]

[0124]

[0125] The boron-containing compound of the present invention can be obtained by combining known synthesis reactions described in Patent Document 1 and the like.

[0126] For example, the compound represented by formula (I-1) can be obtained by the method shown below.

[0127]

[0128] 5-bromo-1,3-difluoro-2-methylbenzene, 3-(diphenylamino)phenol, Cs 2 CO 3 and N-methyl-2-pyrrolidone (NMP) under a nitrogen atmosphere to obtain compound 1.

[0129]

[0130] The above compound 1, bis(4-(tert-butyl)phenyl)amine, NaO(t-Bu), Pd(OAc) 2 and P(t-Bu) 3 H.BF 4 The mixture was added to dry toluene and reacted under a nitrogen atmosphere to obtain compound 2.

[0131]

[0132] The above compound 2 was dissolved in dry 1,2,4-trichlorobenzene, and BI was slowly added to the obtained solution at room temperature. 3 After the reaction was carried out under nitrogen atmosphere, the resulting solution was diluted with dichloromethane and NEt(i-Pr) was slowly added. 2 , and react to obtain compound 3 represented by formula (I-1).

[0133] For example, the compound represented by formula (I-6) can be obtained by the method shown below.

[0134]

[0135] A mixture of 5-bromo-1,3-difluoro-2-methylbenzene, 9-(4-(tert-butyl)phenyl)9H-carbazole-2-ol and N-methyl-2-pyrrolidone (NMP) was reacted under a nitrogen atmosphere to obtain Compound 5.

[0136]

[0137] Compound 5, bis(4-(tert-butyl)phenyl)amine, NaO(t-Bu), Pd(OAc) 2 and P(t-Bu) 3 H.BF 4 The mixture was reacted under a nitrogen atmosphere to obtain compound 6.

[0138]

[0139] N,N-bis(4-(tert-butyl)phenyl)-3,5-bis((9-(4-(tert-butyl)phenyl)-9H-carbazol-2-yl)oxy)-4-methylaniline was dissolved in dry 1,2-dichlorobenzene, and BI was slowly added at room temperature.3 , react under a nitrogen atmosphere to obtain compound 7 represented by formula (I-6).

[0140] For example, the compound represented by formula (I-7) can be obtained by the method shown below.

[0141]

[0142] 5-bromo-1,3-difluoro-2-methylbenzene, 9-(4-(tert-butyl)phenyl)9H-carbazole-4-ol, Cs 2 CO 3 and N-methyl-2-pyrrolidone (NMP) in a nitrogen atmosphere to obtain compound 9.

[0143]

[0144] Compound 9, bis(4-(tert-butyl)phenyl)amine, NaO(t-Bu), Pd(OAc) 2 and P(t-Bu) 3 H.BF 4 The mixture was heated into dry toluene and reacted under a nitrogen atmosphere to obtain compound 10.

[0145]

[0146] N,N-bis(4-(tert-butyl)phenyl)-3,5-bis((9-(4-(tert-butyl)phenyl)-9H-carbazol-4-yl)oxy)-4-methylaniline was dissolved in dry 1,2-dichlorobenzene, and BI was slowly added to the obtained solution at room temperature. 3 , react under a nitrogen atmosphere to obtain compound 11 represented by formula (I-7).

[0147] The synthesized compound can be purified by purification using column chromatography, adsorption purification using silica gel, activated carbon, activated clay, etc., recrystallization from a solvent, crystallization, etc. The compound can be identified by NMR analysis, etc.

[0148] The luminescent material of the present invention can provide luminescent elements such as organic photoluminescent elements and organic electroluminescent elements. The boron-containing compound used in the luminescent material of the present invention can assist other luminescent materials (host materials) in luminescence and can therefore be doped into other luminescent materials for use.

[0149] The organic photoluminescent element of the present invention is formed by providing a light-emitting layer containing the light-emitting material of the present invention on a substrate. The light-emitting layer can be obtained by coating methods such as spin coating, printing methods such as inkjet printing, vapor deposition, etc.

[0150] The organic electroluminescent element of the present invention is formed by providing an organic layer between an anode and a cathode. The "organic layer" in the present invention refers to a layer substantially composed of organic matter located between the anode and the cathode, and these layers may contain inorganic matter within a range that does not impair the performance of the light-emitting element of the present invention.

[0151] As a structure of an embodiment of the organic electroluminescent element of the present invention, a structure consisting of an anode, a hole injection layer, a hole transport layer, an electron blocking layer, a light-emitting layer, a hole blocking layer, an electron transport layer, and a cathode can be cited in sequence on a substrate, and a structure further having an electron injection layer between the electron transport layer and the cathode can be cited. Several organic layers can be omitted in these multilayer structures, for example, an anode, a hole transport layer, a light-emitting layer, an electron transport layer, an electron injection layer, and a cathode can be sequentially formed on a substrate, or an anode, a hole transport layer, a light-emitting layer, an electron transport layer, and a cathode can be sequentially formed on a substrate. The luminescent material of the present invention can be doped not only in a light-emitting layer, but also in a hole injection layer, a hole transport layer, an electron blocking layer, a hole blocking layer, an electron transport layer, or an electron injection layer.

[0152] The substrate is a support for the light-emitting element, and a silicon plate, a quartz plate, a glass plate, a metal plate, a metal foil, a resin film, a resin sheet, etc. can be used. Glass plates, polyesters, polymethacrylates, polycarbonates, polysulfones and other transparent synthetic resin plates are particularly preferred. When using synthetic resin substrates, attention should be paid to gas barrier properties. If the gas barrier properties of the substrate are too low, the light-emitting element is sometimes degraded due to external air passing through the substrate. Therefore, it is preferred to provide a dense silicon oxide film on any single side or both sides of the synthetic resin substrate to ensure gas barrier properties.

[0153] An anode is provided on the substrate. The anode is generally made of a material with a large work function. Examples of anode materials include metals such as aluminum, gold, silver, nickel, palladium, and platinum; indium oxide, tin oxide, ITO, zinc oxide, In 2 O 3 -ZnO, IGZO and other metal oxides, copper iodide and other metal halides, carbon black, or poly (3-methylthiophene), polypyrrole, polyaniline and other conductive polymers. The formation of the anode is usually carried out by sputtering, vacuum evaporation, etc. In addition, in the case of metal particles such as silver, copper iodide and other particles, carbon black, conductive metal oxide particles, conductive polymer powders, etc., it is also possible to form an anode by dispersing them in a suitable binder resin solution and coating them on a substrate. In addition, in the case of conductive polymers, a thin film can be directly formed on the substrate by electrolytic polymerization, or a conductive polymer can be coated on the substrate to form an anode.

[0154] The anode can also be formed by stacking two or more different substances. The thickness of the anode varies according to the required transparency. When transparency is required, it is preferred that the transmittance of visible light is usually 60% or more, preferably 80% or more. In this case, the thickness is usually 10 to 1000 nm, preferably 10 to 200 nm. In the case of being opaque, the anode can be of the same thickness as the substrate. The sheet resistance of the anode is preferably several hundred Ω / □ or more.

[0155] As the hole injection layer provided as required, in addition to porphyrin compounds represented by copper phthalocyanine, naphthalene diamine derivatives, starburst triphenylamine derivatives, aromatic amine compounds having a structure in which three or more triphenylamine structures are connected by a single bond or a divalent group containing no heteroatoms, triphenylamine trimers and tetramers, acceptor heterocyclic compounds such as hexacyanoazatriphenylene, and coating-type polymer materials can also be used. These materials can also be formed into thin films by known methods such as spin coating and inkjet method in addition to the vapor deposition method.

[0156] As a hole transport material used in a hole transport layer set as needed, it is preferred that the hole injection efficiency from the anode is high and the injected holes can be efficiently transported. For this reason, it is preferred that the ionization potential is small, the transparency to visible light is high, and the hole mobility is large, and the stability is excellent, and it is not easy to produce impurities that become traps during manufacturing and use. In addition to the general requirements mentioned above, in the case of applications for vehicle-mounted displays, it is further preferred that the heat resistance of the element is high. Therefore, a material having a value of 70°C or more as Tg is preferred.

[0157] Examples of the hole transport layer provided as necessary include triazole derivatives, Oxadiazole derivatives, imidazole derivatives, carbazole derivatives, indolecarbazole derivatives, polyarylalkane derivatives, pyrazoline derivatives, pyrazolone derivatives, phenylenediamine derivatives, arylamine derivatives, amino-substituted chalcone derivatives, Azoles derivatives, styrylanthracene derivatives, fluorenone derivatives, hydrazone derivatives, stilbene derivatives, silazane derivatives, aniline copolymers, conductive polymer oligomers, etc. More specifically, compounds containing m-carbazolylphenyl, N,N'-diphenyl-N,N'-di(m-tolyl)-benzidine (hereinafter referred to as TPD), N,N'-diphenyl-N,N'-di(α-naphthyl)-benzidine (hereinafter referred to as NPD), N,N,N',N'-tetraphenylbenzidine and other benzidine derivatives, 1,1-bis[(di-4-tolylamino)phenyl]cyclohexane (hereinafter referred to as TAPC), various triphenylamine trimers and tetramers, carbazole derivatives, etc. They can be used alone or in combination of two or more. The hole transport layer can be a single-layer film or a laminated film. In addition, as the hole injection / hole transport layer, a coating type polymer material such as poly(3,4-ethylenedioxythiophene) (hereinafter referred to as PEDOT) / polystyrenesulfonic acid (hereinafter referred to as PSS) can be used. These materials can be formed into a thin film by a known method such as spin coating, inkjet, etc. in addition to the vapor deposition method.

[0158] In addition, the hole injection layer or the hole transport layer can use a material that is further P-doped with tribromoaniline antimony hexachloride or a polymer compound having a PD structure in a partial structure thereof. As a host material for hole injection and transport properties, carbazole derivatives such as CBP, TCTA, and mCP can be used.

[0159] Preferred compounds (hi1) to (hi7) that can be used as the hole injection material are listed below.

[0160]

[0161]

[0162]

[0163] Preferred compounds (ht1) to (ht38) that can be used as hole transport materials are listed below.

[0164]

[0165]

[0166]

[0167]

[0168]

[0169]

[0170]

[0171]

[0172]

[0173]

[0174]

[0175]

[0176] As the electron blocking layer provided as required, carbazole such as 4,4',4"-tri(N-carbazyl)triphenylamine (hereinafter referred to as TCTA), 9,9-bis[4-(carbazol-9-yl)phenyl]fluorene, 1,3-bis(carbazol-9-yl)benzene (hereinafter referred to as mCP), 1,3-bis(1,8-dimethylcarbazol-9-yl)benzene (hereinafter referred to as mMCP), 2,2-bis(4-carbazol-9-ylphenyl)adamantane (hereinafter referred to as Ad-Cz) can be used. Derivatives, compounds having a triphenylsilyl and triarylamine structure represented by 9-[4-(carbazole-9-yl)phenyl]-9-[4-(triphenylsilyl)phenyl]-9H-fluorene, and the like having an electron blocking effect. They can be used alone or in combination of two or more. The electron blocking layer can be a film of a single-layer structure or a film of a laminated structure. These materials can also be formed into thin films by known methods such as spin coating and inkjet in addition to the evaporation method.

[0177] Preferred compounds (es1) to (es5) that can be used as the electron blocking material are listed below.

[0178]

[0179]

[0180] The light-emitting layer is a layer that emits light by generating excitons by recombination of holes and electrons injected from the anode and the cathode, respectively. The light-emitting layer can be formed by the light-emitting material of the present invention alone, or by doping the light-emitting material of the present invention into a host material. Examples of the host material include metal complexes of quinolinol derivatives such as tris(8-hydroxyquinoline)aluminum (hereinafter referred to as Alq3), anthracene derivatives, bis(styrylbenzene) derivatives, pyrene derivatives, Azoles derivatives, polyparaphenylene vinylene derivatives, compounds having bipyridine and o-terphenyl structures, 1,3-bis(carbazole-9-yl)benzene (hereinafter referred to as mCP), 3,3'-bis(9H-carbazole-9-yl)-1,1'-biphenyl (hereinafter referred to as mCBP), thiazole derivatives, benzimidazole derivatives, polydialkylfluorene derivatives, etc. The light-emitting layer may contain a known dopant. As dopants, quinacridone, coumarin, rubrene, anthracene, perylene and their derivatives, benzopyran derivatives, rhodamine derivatives, aminostyryl derivatives, etc. may be cited. In addition, phosphorescent luminescent bodies such as green phosphorescent luminescent bodies such as Ir(ppy)3, blue phosphorescent luminescent bodies such as FIrpic and FIr6, and red phosphorescent luminescent bodies such as Btp2Ir(acac) may also be used. They may be used alone or in combination of two or more. The light-emitting layer may be a film of a single-layer structure or a film of a laminated structure. These materials can be formed into a thin film by a known method such as a spin coating method, an ink jet method, etc. other than a vapor deposition method.

[0181] When a host material is used, the lower limit of the amount of the light-emitting material of the present invention that can be contained in the light-emitting layer is preferably 0.1 mass %, more preferably 1 mass %, and the upper limit is preferably 50 mass %, more preferably 20 mass %, and further preferably 10 mass %.

[0182] Preferred compounds (e11) to (e140) that can be used as the host material of the light-emitting layer are listed below.

[0183]

[0184]

[0185]

[0186]

[0187]

[0188]

[0189]

[0190]

[0191]

[0192] Examples of the hole blocking layer provided as required include compounds having a bipyridyl group and an o-terphenyl structure, phenanthroline derivatives such as bathocuproin (hereinafter referred to as BCP), metal complexes of quinolinol derivatives such as bis(2-methyl-8-quinolinyl)-4-phenylphenol aluminum (III) (hereinafter referred to as BAlq), various rare earth complexes, Compounds having hole blocking effects such as azole derivatives, triazole derivatives, and triazine derivatives. These materials can also serve as materials for the electron transport layer. They can be used alone or in combination of two or more. The hole blocking layer can be a film of a single-layer structure or a film of a laminated structure. In addition to the evaporation method, these materials can also be formed into a thin film by known methods such as spin coating and inkjet.

[0193] Preferred compounds (hs1) to (hs11) that can be used as the hole blocking material are listed below.

[0194]

[0195]

[0196]

[0197]

[0198] As the electron transport layer provided as required, in addition to metal complexes of quinolinol derivatives represented by Alq3 and BAlq, various metal complexes, triazole derivatives, triazine derivatives, Oxadiazole derivatives, thiadiazole derivatives, carbodiimide derivatives, quinoxaline derivatives, phenanthroline derivatives, silole derivatives, etc. They can be used alone or in combination of two or more. The electron transport layer can be a film of a single layer structure or a film of a laminated structure. These materials can also be formed into thin films by known methods such as spin coating and inkjet in addition to evaporation.

[0199] As the electron injection layer provided as necessary, alkali metal salts such as lithium fluoride and cesium fluoride, alkaline earth metal salts such as magnesium fluoride, metal oxides such as aluminum oxide, etc. can be used, but they can be omitted in the preferred selection of the electron transport layer and the cathode.

[0200] For the electron injection layer or the electron transport layer, a material generally used for the layer may be further N-doped with a metal such as cesium.

[0201] Preferred compounds (et1) to (et30) that can be used as electron transport materials are listed below.

[0202]

[0203]

[0204]

[0205]

[0206]

[0207]

[0208]

[0209]

[0210] Preferred compounds (ei1) to (ei4) that can be used as the electron injecting material are listed below.

[0211]

[0212] Preferred compounds (st1) to (st5) that can be used as the stabilizing material are listed below.

[0213]

[0214]

[0215] The cathode generally uses a material with a small work function. As the cathode material, for example, sodium, sodium-potassium alloy, lithium, tin, magnesium, magnesium / copper mixture, magnesium / aluminum mixture, magnesium / indium mixture, aluminum / aluminum oxide mixture, indium, calcium, aluminum, silver, lithium / aluminum mixture, magnesium-silver alloy, magnesium-indium alloy, aluminum-magnesium alloy, etc. can be used. By using a transparent conductive material, a transparent or translucent cathode can be obtained. The thickness of the cathode is generally 10 to 5000 nm, preferably 50 to 200 nm. The sheet resistance of the cathode is preferably several hundred Ω / □ or more.

[0216] It should be noted that for the purpose of protecting the cathode composed of a low work function metal, if a metal layer with a high work function and stable in the atmosphere such as aluminum, silver, nickel, chromium, gold, platinum is further stacked thereon, the stability of the element can be enhanced, and thus it is preferred. In addition, in order to improve the contact between the cathode and the adjacent organic layer (e.g., electron transport layer, electron injection layer), a cathode interface layer can be provided between the two. As the material used in the cathode interface layer, aromatic diamine compounds, quinacridone compounds, tetracene derivatives, organosilicon compounds, organophosphorus compounds, compounds with N-phenylcarbazole skeletons, N-vinylcarbazole polymers, etc. can be cited.

[0217] The light emitting element of the present invention can be applied to a single element, an element having a structure arranged in an array, or a structure in which an anode and a cathode are arranged in an XY matrix.

[0218] Hereinafter, the present invention will be described with reference to Examples.

[0219] (Example 1)

[0220]

[0221] 5-Bromo-1,3-difluoro-2-methylbenzene (0.25 g, 1.2 mmol), 3-(diphenylamino)phenol (0.68 g, 2.6 mmol), Cs 2 CO 3 A mixture of 1.56 g, 4.8 mmol) and N-methyl-2-pyrrolidone (NMP, 12 mL) was stirred at 170°C for 18 hours under a nitrogen atmosphere. The mixture was cooled to room temperature, and then the obtained solution was added to a large amount of water. The product was extracted with ethyl acetate, and the organic layer was washed with brine and washed with anhydrous Na 2 SO 4 The crude product was filtered and evaporated, and purified by silica gel column chromatography (eluent: hexane / dichloromethane = 6:1, v / v) to obtain Compound 1 as a white solid (yield = 0.65 g, 79 mass %).

[0222]

[0223] The above compound 1 (0.62 g, 0.9 mmol), bis(4-(tert-butyl)phenyl)amine (0.31 g, 1.1 mmol), NaO(t-Bu) (0.17 g, 1.8 mmol), Pd(OAc) 2 (0.002 g, 0.009 mmol) and P(t-Bu) 3 H.BF 4 A mixture of 1,4-dihydro-1,4-dihydro-2-nitropropene (0.003 g, 0.009 mmol) was added to dry toluene (9 mL) and refluxed under a nitrogen atmosphere for 14 hours. The mixture was cooled to room temperature, and then diluted with ethyl acetate and filtered through a CELITE (registered trademark, diatomaceous earth) pad. The filtrate was washed with water and washed with anhydrous Na 2 SO 4 The crude product was filtered and evaporated, and purified by silica gel column chromatography (eluent: hexane / dichloromethane = 3:1, v / v) to obtain Compound 2 as a white solid (yield = 0.62 g, 77 mass %).

[0224]

[0225] The above compound 2 (0.089 g, 0.1 mmol) was dissolved in dry 1,2,4-trichlorobenzene (1.5 mL), and BI was slowly added to the obtained solution at room temperature. 3 (0.098 g, 0.25 mmol). The mixture was stirred at 180°C (bath temperature) for 20 hours under a nitrogen atmosphere. The mixture was cooled to 0°C and then diluted with dichloromethane. NEt(i-Pr) was then slowly added. 2 (0.03 mL, 0.2 mmol), and then stirred at 0°C for 30 minutes. Then, Na 2 SO 3 The aqueous solution was quenched. Then it was extracted with dichloromethane. 2 SO 4 The organic layer was dried, filtered and evaporated, and the resulting crude product was purified by silica gel column chromatography (eluent: hexane / dichloromethane = 4:1, v / v) to obtain Compound 3 (BOBO-Ω) as a yellow solid (yield = 0.030 g, 33 mass %).

[0226] (Example 2)

[0227]

[0228] 5-Bromo-1,3-difluoro-2-methylbenzene (1.00 g, 4.84 mmol), 9-(4-(tert-butyl)phenyl)9H-carbazole-2-ol (Compound 4: 3.20 g, 10.2 mmol), Cs 2 CO 3 A mixture of (4.72 g, 14.4 mmol) and N-methyl-2-pyrrolidone (NMP, 20 mL) was stirred at 170 ° C for 20 hours under a nitrogen atmosphere. It was cooled to room temperature and then added to 100 ml of 5% by volume hydrochloric acid, and the precipitated crystals were extracted with chloroform. The organic layer was washed with brine, dried over anhydrous magnesium sulfate, filtered and evaporated, and the crude product was washed with ether to obtain compound 5 as a white solid (yield = 3.88 g, 87.6 mass%).

[0229]

[0230] The above compound 5 (1.00 g, 1.25 mmol), bis(4-(tert-butyl)phenyl)amine (0.53 g, 1.88 mmol), NaO(t-Bu) (0.22 g, 2.29 mmol), Pd(OAc) 2 (14.0 mg, 0.065 mmol) and P(t-Bu) 3 H.BF 4A mixture of (29.7 mg, 0.10 mmol) was added to dry toluene (16 mL) and refluxed under a nitrogen atmosphere for 6 hours. Cooled to room temperature, the resulting solution was diluted with ethyl acetate and filtered through a CELITE (registered trademark, diatomaceous earth) pad. The filtrate was washed with water and dried over anhydrous magnesium sulfate. Filtration and evaporation were performed, and the crude product was purified by silica gel column chromatography (eluent: hexane / chloroform = 4:1, v / v) to obtain compound 6 as a white solid (yield = 1.16 g, 93.1% by mass).

[0231]

[0232] Compound 6 (1.00 g, 1.0 mmol) was dissolved in dry 1,2-dichlorobenzene (80 mL), and BI was slowly added to the resulting solution at room temperature. 3 (1.37 g, 3.50 mmol). The mixture was stirred at 180°C (bath temperature) for 48 hours under a nitrogen atmosphere. After cooling to 0°C, the resulting solution was diluted with dichloromethane, and then Na 2 SO 3 The mixture was quenched with an aqueous solution (0.50 mol / L, 10 mL). After stirring at 0°C for 10 minutes, the mixture was extracted with dichloromethane. 2 SO 4 The organic layer was dried, filtered and evaporated, and the resulting crude product was purified by silica gel column chromatography (eluent: hexane / dichloromethane = 1:3, v / v) to obtain Compound 7 (BOBO-Ψ) as a yellow solid (yield = 0.08 g, 8 mass %).

[0233] 1 H NMR (400 MHz, CDCl 3 ,δ):9.52(s,2H),9.00(s,2H),8.33(t,4H),7.69(t,6H),7.61(t,6H),7.46(m,4H),7.44-7.38(m,2H),2.79(s,3H),1.61-1.56(m,18H),1.51-1.47(m,18H).MS(MALDI-TOF):m / zcalculated value 1013.53[M]+; found value 1013.76.

[0234] (Example 3)

[0235]

[0236] 5-Bromo-1,3-difluoro-2-methylbenzene (1.00 g, 4.84 mmol), 9-(4-(tert-butyl)phenyl)9H-carbazole-4-ol (Compound 8) (3.20 g, 10.2 mmol), Cs 2 CO 3 A mixture of (4.72 g, 14.4 mmol) and N-methyl-2-pyrrolidone (NMP, 20 mL) was stirred at 170 ° C for 24 hours under a nitrogen atmosphere. After cooling to room temperature, 100 ml of 5% by volume hydrochloric acid was added, and the precipitated crystals were extracted with chloroform. The organic layer was washed with brine, dried over anhydrous magnesium sulfate, filtered and evaporated, and the crude product was washed with ether to obtain compound 9 as a white solid (yield = 3.05 g, 79.1% by mass).

[0237]

[0238] Compound 9 (1.00 g, 1.25 mmol), bis(4-(tert-butyl)phenyl)amine (0.53 g, 1.88 mmol), NaO(t-Bu) (0.22 g, 2.29 mmol), Pd(OAc) 2 (14.0 mg, 0.065 mmol) and P(t-Bu) 3 H.BF 4 (29.7mg, 0.10mmol) was added to dry toluene (10mL) and refluxed under a nitrogen atmosphere for 4 hours. Cooled to room temperature, the resulting solution was diluted with ethyl acetate and filtered through a CELITE (registered trademark, diatomaceous earth) pad. The filtrate was washed with water and dried over anhydrous magnesium sulfate. Filtering and evaporation were performed, and the crude product was washed with a mixed solvent of hexane / chloroform = 4 / 1 to obtain 1.21g of crude crystals of compound 10. Purification was performed by silica gel column chromatography (eluent: hexane / chloroform = 4:1, v / v) to obtain compound 10 as a white solid (yield = 1.10g, 88.3% by mass).

[0239]

[0240] Compound 10 (1.00 g, 1.0 mmol) was dissolved in dry 1,2-dichlorobenzene (80 mL), and BI was slowly added to the resulting solution at room temperature. 3 (1.37 g, 3.50 mmol). The mixture was stirred at 180°C (bath temperature) for 48 hours under a nitrogen atmosphere. After cooling to 0°C, the resulting solution was diluted with dichloromethane, and then Na 2 SO 3The mixture was quenched with an aqueous solution (0.50 mol / L, 10 mL). After stirring at 0°C for 10 minutes, the mixture was extracted with dichloromethane. 2 SO 4 The organic layer was dried, filtered and evaporated, and the resulting crude product was purified by silica gel column chromatography (eluent: hexane / dichloromethane = 4:1, v / v) to obtain compound 11 (BOBO-X) as a light yellow solid (yield = 0.16 g, 16 mass %).

[0241] 1 H NMR (400 MHz, CDCl 3 ,δ):9.15(d,J=7.60Hz,2H),8.85(s,2H),8.80(d,J=8.80Hz,2H),8.30(d,J=8.80Hz,2H),7.69(d,J=8.40Hz,2H),7.64-7.50(m,14H),3.49(s,3H),1.50-1.48(m,36H).MS(MALDI-TOF):m / zcalculated value 1013.53[M]+; found value 1013.67.

[0242] The evaluation of the light emission characteristics shown below was performed using a source meter (Keithley: 2400 series), a spectroradiometer (Konica Minolta: CS-2000), a fluorescence spectrophotometer (JASCO Corporation: FP-8600), and a 100 mmΦ integrating sphere (JASCO Corporation: ILF-835).

[0243] (Test Example 1)

[0244] In a glove box under nitrogen atmosphere, 10 mol of each of BOBO-Ω (compound represented by formula (I-1)), BOBO-Ψ (compound represented by formula (I-6)), and BOBO-X (compound represented by formula (I-7)) were prepared. -5 M toluene solution. The PL spectrum of this solution was measured. The results are shown in Table 1. Figure 1 Each absorption spectrum is shown in . Figure 2 PL spectra (wavelength of fluorescence or phosphorescence emitted at a temperature of 77 K (non-thermal activation)) are shown in FIG. Figure 3 The transient TRPL characteristics are shown in FIG. Figure 3 The “IRF” in stands for the device response function.

[0245] The absorption spectrum was measured using a UV-visible near-infrared spectrophotometer (V-670 manufactured by JASCO Corporation), the PL spectrum was measured using a fluorescence spectrophotometer (FP-8600 manufactured by JASCO Corporation), and the TRPL characteristics were measured by a conventional method using a Quantaurus-Tau small fluorescence lifetime measurement device C-11367 (manufactured by Hamamatsu Photonics).

[0246]

[0247] [Table 1]

[0248]

[0249] λ FWHM : Half peak width (wavelength); E FWHM : Half peak width (energy); Φ PL : Luminescence quantum yield; τ p / τ d : Instantaneous fluorescence lifetime / delayed fluorescence lifetime; k r,s : fluorescence emission rate constant; k ISC : intersystem crossing rate constant; k RISC : reverse intersystem crossing rate constant; Φ p / Φ d : Instantaneous fluorescence quantum yield / delayed fluorescence quantum yield; ΔE ST :S 1 Status and T 1 Energy difference between states

[0250] (Test Example 2)

[0251] Using 3,3'-di(9H-carbazole-9-yl)-1,1'-biphenyl (mCBP) as a host material of the evaporation source and 1% by mass of BOBO-Ω (a compound represented by the formula (I-1)), BOBO-Ψ (a compound represented by the formula (I-6)) or BOBO-X (a compound represented by the formula (I-7)), the evaporation source was stirred for 10 min. -4 The film was deposited on a quartz substrate using a vacuum deposition apparatus E-200 (manufactured by ALS Technology Co., Ltd.) under conditions of Pa or less to obtain a thin film having a thickness of 100 nm.

[0252] Figure 4 PL spectra (wavelength of fluorescence or phosphorescence emitted at a temperature of 77 K (non-thermal activation)) are shown in FIG. Figure 5 The transient TRPL characteristics are shown in FIG. Figure 5The "IRF" in refers to the device response function. The PL spectrum was measured using a fluorescence spectrophotometer (manufactured by JASCO Corporation: FP-8600), and the TRPL characteristics were measured by a conventional method using a Quantaurus-Tau compact fluorescence lifetime measurement device C-11367 (manufactured by Hamamatsu Photonics).

[0253] [Table 2]

[0254]

[0255] (Test Example 3)

[0256] On a glass substrate on which an anode (50 nm thick) composed of indium tin oxide (ITO) was formed, a vacuum deposition method (5.0 × 10 -4 Pa or less) are stacked in sequence: a 10nm thick 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-azatriphenylene (HAT-CN) film, a 40nm thick 1,1-bis[4-[N,N-di(p-tolyl)amino]phenyl]cyclohexane (TAPC) film, a 10nm thick 1,3-bis(1,8-dimethylcarbazole-9-yl)benzene (mMCP) film, a 30nm thick 1 wt% BOBOΩ:3,3'-di(9H-carbazole-9-yl)-1,1'-biphenyl (mCBP) film, a 10nm thick 2,8-bis(diphenylphosphoryl)dibenzo[b,d]furan (PPF) film, and a 30nm thick 1,3-bis[3,5-di(pyridin-3-yl)phenyl]benzene (B3PyPB) film.

[0257] Next, a 1 nm thick 8-hydroxyquinoline lithium film and a 100 nm thick aluminum film were further laminated in this order by vacuum deposition (vacuum deposition apparatus E-200 (manufactured by ALS Technology Co., Ltd.)) to form a cathode, thereby obtaining an organic electroluminescent element.

[0258] An organic electroluminescent device was obtained in the same manner as the above method except that 2 wt % BOBO-Ψ or 2 wt % BOBO-X was used instead of 1 wt % BOBO-Ω.

[0259] The properties of the obtained organic electroluminescent elements were measured. Table 3 shows the light emission properties. Figure 6 EL spectra are shown in FIG. Figure 7 The voltage-current density-luminance characteristics are shown in FIG. Figure 8 The luminance-external quantum efficiency characteristics are shown in . The electroluminescence characteristics were evaluated by a conventional method using a source meter (2400 series manufactured by Keithley) and a spectral emission luminance meter (CS-2000 manufactured by Konica Minolta).

[0260] [Table 3]

[0261]

[0262] V on : On-state voltage; L max : Maximum brightness; CE max : Maximum current efficiency; PE max : Maximum power efficiency; CIE(x,y): CIE chromaticity coordinates (CIE 1931 chromaticity diagram); @10 2 cdm -2 : Brightness 10 2 cdm -2 EQE(%) at 10 3 cdm -2 : Brightness 10 3 cdm -2 EQE at time (%)

[0263] The light-emitting element of the present invention emits blue light in a narrow wavelength band with high external quantum efficiency.

Claims

1. A compound represented by formula (I), In the formula (I), R 1 is C1-4 alkyl, substituted or unsubstituted phenyl, substituted or unsubstituted naphthyl, substituted or unsubstituted anthracenyl, or substituted or unsubstituted phenanthrenyl, A 1 and A 2 are each independently a group represented by formula (II), a group represented by formula (III), a group represented by formula (IV), a group represented by formula (V), a group represented by formula (VI), a group represented by formula (VII), a group represented by formula (VIII) or a group represented by formula (IX), In the formula (II), formula (III), formula (IV), formula (V), formula (VI), formula (VII), formula (VIII) and formula (IX), R 2 and R 3 are each independently a hydrogen atom, a C1-4 alkyl group, or a substituted or unsubstituted phenyl group, * is the bonding part.

2. The compound according to claim 1, wherein In the formula (II), formula (III), formula (IV), formula (V), formula (VI), formula (VII), formula (VIII) and formula (IX), R 2 and R 3 Each is independently a hydrogen atom or a tert-butyl group.

3. A light-emitting material comprising the compound according to claim 1 or 2.

4. A light-emitting element comprising the light-emitting material according to claim 3.

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