Compound and organic electroluminescent device

Abstract

To provide a novel blue light-emitting material which has a narrow width of an emission spectrum, can realize high colorimetric purity, and may improve luminescence efficiency of an organic electroluminescence device.SOLUTION: The invention provides a compound having a rigid structure in which aromatic hydrocarbon rings or heteroaromatic rings are condensed, such as formula (3). In the formula, Ar31 to Ar35 are each independently an aromatic hydrocarbon ring having 6-14 ring-forming atoms or a heteroaromatic ring having 5-14 ring-forming atoms; and R31 to R35 are each independently a deuterium atom, a halogen atom, a substituted or unsubstituted alkyl group, or the like.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a compound and an organic electroluminescence device. [Background technology]

[0002] Organic electroluminescence elements are being actively developed as image display devices. Organic electroluminescence elements are so-called self-luminous display devices that realize display by causing the organic light-emitting material contained in the light-emitting layer to emit light by recombining holes and electrons injected from the first electrode and the second electrode in the light-emitting layer.

[0003] Known organic electroluminescence elements include, for example, an element that includes a first electrode, a light-emitting layer disposed on the first electrode, and a second electrode disposed on the light-emitting layer. In this element, holes are injected from the first electrode, and the holes are injected into the light-emitting layer. Meanwhile, electrons are injected from the second electrode, and the electrons are injected into the light-emitting layer. The holes and electrons injected into the light-emitting layer are recombined to generate excitons in the light-emitting layer. This element emits light by utilizing the light generated when the excitons fall to the ground state.

[0004] Various compounds have been investigated as light-emitting materials for use in organic electroluminescence devices. In particular, fused ring compounds containing heteroatoms have been investigated as blue-emitting materials (Patent Documents 1 to 4).

[0005] In addition, it is expected that organic electroluminescence elements can emit light more efficiently by utilizing triplet excitons in addition to singlet excitons. In light of this background, materials that exhibit thermally activated delayed fluorescence have been studied in recent years (Non-Patent Document 1).

[0006] TADF (Thermally Activated Delayed Fluorescence) is a method to detect the energy difference between the singlet and triplet levels (ΔE STThis utilizes the phenomenon that reverse intersystem crossing from triplet excitons to singlet excitons occurs thermally when a material with a small intersystem charge is used. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] China Patent Application Publication No. 110790782 [Patent Document 2] International Publication No. 2018 / 186404 [Patent Document 3] China Patent Application Publication No. 107501311 [Patent Document 4] International Publication No. 2015 / 102118 [Non-patent literature]

[0008] [Non-Patent Document 1] T.Taniguchi et al.,Chem.Lett.2019,48,1160-1163 Summary of the Invention [Problem to be solved by the invention]

[0009] In order to cover a wide color gamut, organic electroluminescence elements require light-emitting materials with high color purity for each of the red, green, and blue (R, G, B) colors. Color purity is related to the emission spectrum width, and the narrower the emission spectrum width, the higher the color purity.

[0010] However, it is known that it is difficult to achieve emission of high color purity, particularly in blue light-emitting materials. The materials described in the above patent documents and non-patent documents have problems such as a wide emission spectrum width and insufficient color purity.

[0011] Therefore, an object of the present invention is to provide a novel blue light-emitting material that has a narrow emission spectrum width, can realize high color purity, and can improve the luminous efficiency of an organic electroluminescence device. [Means for solving the problem]

[0012] The above-mentioned object of the present invention can be achieved by the following means. That is, one aspect of the present invention is a compound represented by the following formula (1) and formula (2):

[0013] [ka]

[0014] In the above formula (1) and the above formula (2), Ar 1 ~Ar 5 are each independently an aromatic hydrocarbon ring having 6 to 14 ring atoms or an aromatic heterocycle having 5 to 14 ring atoms, R 1 ~R 5 each independently represents a deuterium atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted haloalkyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted alkylthio group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, a substituted or unsubstituted aryloxy group, a substituted or unsubstituted heteroaryloxy group, a substituted or unsubstituted arylthio group, a substituted or unsubstituted heteroarylthio group, or a substituted or unsubstituted amino group; n1 is 0, 1, 2, 3, 4, 5, or 6; n2 and n5 are each independently 0, 1, 2, 3, 4, 5, 6, 7, or 8; n3 and n4 are each independently 0, 1, 2, 3, 4, 5, 6, or 7; When any of n1 to n5 is 2 or more, each R 1 , each R 2 , each R 3 , each R 4or each R 5 may be the same or different, The two bonds * in the formula (2) are Ar 1 the ring-forming atoms of the formula (1), 2 or Ar 3 is bonded to a ring-forming atom of Effect of the Invention

[0015] According to the present invention, a novel blue light-emitting material can be provided which has a narrow emission spectrum width, can realize high color purity, and can improve the luminous efficiency of an organic electroluminescence device. [Brief description of the drawings]

[0016] [Figure 1] 1 is a schematic cross-sectional view showing an organic electroluminescence element according to one embodiment of the present invention. [Diagram 2] FIG. 4 is a schematic cross-sectional view showing an organic electroluminescence element according to another embodiment of the present invention. [Diagram 3] FIG. 4 is a schematic cross-sectional view showing an organic electroluminescence element according to another embodiment of the present invention. [Figure 4] FIG. 1 shows a 1H-NMR spectrum of compound (15). [Diagram 5] FIG. 1 shows a 1H-NMR spectrum of compound (16). DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] The following describes the embodiments of the present invention. Note that the present invention is not limited to the following embodiments. Unless otherwise specified, the operation and measurement of physical properties are performed under the conditions of room temperature (20°C to 25°C) and relative humidity of 40% RH to 50% RH.

[0018] In this specification, "X and Y are each independently" means that X and Y may be the same or different.

[0019] In addition, in this specification, the term "group derived from a ring" refers to a group obtained by removing hydrogen atoms directly bonded to ring-forming atoms from a ring structure in an amount equal to the valence number, resulting in a free valence.

[0020] <Fused ring compounds> One aspect of the present invention is a compound represented by the following formulas (1) and (2):

[0021] [ka]

[0022] In the above formula (1) and the above formula (2), Ar 1 ~Ar 5 are each independently an aromatic hydrocarbon ring having 6 to 14 ring atoms or an aromatic heterocycle having 5 to 14 ring atoms, R 1 ~R 5 each independently represents a deuterium atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted haloalkyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted alkylthio group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, a substituted or unsubstituted aryloxy group, a substituted or unsubstituted heteroaryloxy group, a substituted or unsubstituted arylthio group, a substituted or unsubstituted heteroarylthio group, or a substituted or unsubstituted amino group; n1 is 0, 1, 2, 3, 4, 5, or 6; n2 and n5 are each independently 0, 1, 2, 3, 4, 5, 6, 7, or 8; n3 and n4 are each independently 0, 1, 2, 3, 4, 5, 6, or 7; When any of n1 to n5 is 2 or more, each R 1 , each R 2 , each R 3 , each R 4 or each R 5may be the same or different, The two bonds * in the above formula (2) are Ar 1 The ring-forming atoms of the above formula (1) are 2 or Ar 3 is bonded to a ring-forming atom of

[0023] In the above formula (1) and the above formula (2), n1, n2, n3, n4, or n5 is 0, the corresponding R 1 , R 2 , R 3 , R 4 or R 5 That is, in the above formula (1) and the above formula (2), the substituent R 1 , R 2 , R 3 , R 4 or R 5 A ring-forming atom to which the formula may be bonded is unsubstituted, and a hydrogen atom is bonded to the ring-forming atom.

[0024] Hereinafter, the compound according to the present invention will also be simply referred to as a “fused ring compound.” Furthermore, the organic electroluminescence device will also be simply referred to as an “organic EL device.”

[0025] The fused ring compound according to the present invention has a narrow emission spectrum width, can realize high color purity, and can improve the luminous efficiency of an organic EL device.

[0026] The present inventors presume that the mechanism by which the above-mentioned configuration solves the problem is as follows.

[0027] The compounds represented by the above formula (1) and formula (2) have a rigid structure in which an aromatic hydrocarbon ring or an aromatic heterocycle is condensed, so that structural relaxation in the excited state is suppressed. As a result, the width of the blue emission spectrum of the compound is narrowed and the color purity is high. In addition, the compounds represented by the above formula (1) and formula (2) have a spatial separation between the HOMO and the LUMO, so that ΔE STTherefore, the light emitting efficiency of the organic EL element can be improved.

[0028] The above mechanism is based on speculation, and the correctness or incorrectness of the mechanism does not affect the technical scope of the present invention. Similarly, the correctness or incorrectness of other speculations in this specification does not affect the technical scope of the present invention.

[0029] Formula (2) has two asterisks "*", which indicate the points of attachment to the partial structure represented by formula (1). The two "*"s indicate the points of attachment to the Ar 1 The ring-forming atoms of formula (1) are 2 or Ar 3 to form a compound.

[0030] The compound may have one, two, or three groups represented by the above formula (2). That is, examples of the form in which the group represented by the above formula (2) is bonded to the partial structure represented by the above formula (1) include the following: 1. The embodiment having one group represented by (2) above (1-1) The group represented by formula (2) is Ar 1 Bonding only to ring-forming atoms (1-2) The group represented by formula (2) is Ar 2 Bonding only to ring-forming atoms (1-3) The group represented by formula (2) is Ar 3 Bonding only to ring-forming atoms 2. The embodiment having two groups represented by (2) above (2-1) One group represented by formula (2) is Ar 1 and another group represented by formula (2) is Ar 2 The form of bonding to the ring-forming atoms of (2-2) One group represented by formula (2) is Ar 1 and another group represented by formula (2) is Ar 3 The form of bonding to the ring-forming atoms of (2-3) One group represented by formula (2) is Ar 2 and another group represented by formula (2) is Ar 3 The form of bonding to the ring-forming atoms of 3. The embodiment having three groups represented by (2) above (3-1) One group represented by formula (2) is Ar 1 and another group represented by formula (2) is Ar 2 and another group represented by formula (2) is bonded to a ring-forming atom of Ar 3 The form of bonding to the ring-forming atoms of Preferably, the group represented by the formula (2) is Ar 1 This is a form in which the ring is bonded only to the ring-forming atoms.

[0031] The compounds represented by the above formulas (1) and (2) are preferably compounds represented by the following formula (3): By having the structure represented by the following formula (3), the width of the blue emission spectrum can be narrowed, higher color purity can be achieved, and the luminous efficiency of the organic EL element can be improved.

[0032] [ka]

[0033] In the above formula (3), Ar 31 ~Ar 35 are each independently an aromatic hydrocarbon ring having 6 to 14 ring atoms or an aromatic heterocycle having 5 to 14 ring atoms, R 31 ~R 35each independently represents a deuterium atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted haloalkyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted alkylthio group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, a substituted or unsubstituted aryloxy group, a substituted or unsubstituted heteroaryloxy group, a substituted or unsubstituted arylthio group, a substituted or unsubstituted heteroarylthio group, or a substituted or unsubstituted amino group; m1 is 0, 1, 2, 3, 4, 5, or 6; m2 and m5 are each independently 0, 1, 2, 3, 4, 5, 6, 7, or 8; m3 and m4 are each independently 0, 1, 2, 3, 4, 5, 6, or 7; If any of m1 to m5 is 2 or more, each R 31 , each R 32 , each R 33 , each R 34 or each R 35 may be the same or different.

[0034] In the above formula (3), m1, m2, m3, m4, or m5 is 0, the corresponding R 31 , R 32 , R 33 , R 34 or R 35 That is, in the above formula (3), the substituent R 31 , R 32 , R 33 , R 34 or R 35 A ring-forming atom to which the formula may be bonded is unsubstituted, and a hydrogen atom is bonded to the ring-forming atom.

[0035] The compound represented by the above formula (1) or (2) is also preferably a compound represented by the following formula (4): By having the structure represented by the following formula (4), the width of the blue emission spectrum can be narrowed, higher color purity can be achieved, and the luminous efficiency of the organic EL element can be improved.

[0036] [ka]

[0037] In the above formula (4), Ar 41 ~Ar 45 are each independently an aromatic hydrocarbon ring having 6 to 14 ring atoms or an aromatic heterocycle having 5 to 14 ring atoms, R 41 ~R 45 each independently represents a deuterium atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted haloalkyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted alkylthio group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, a substituted or unsubstituted aryloxy group, a substituted or unsubstituted heteroaryloxy group, a substituted or unsubstituted arylthio group, a substituted or unsubstituted heteroarylthio group, or a substituted or unsubstituted amino group; l1 is 0, 1, 2, 3, 4, 5, or 6; l2 and l5 are each independently 0, 1, 2, 3, 4, 5, 6, 7, or 8; l3 and l4 are each independently 0, 1, 2, 3, 4, 5, 6, or 7; If any of l1 to l5 is 2 or more, each R 41 , each R 42 , each R 43 , each R 44 or each R 45 may be the same or different.

[0038] In the above formula (4), when l1, l2, l3, l4, or l5 is 0, the corresponding R 41 , R 42 , R 43 , R 44 or R 45 That is, in the above formula (4), the substituent R 41 , R 42 , R 43 , R 44 or R 45 A ring-forming atom to which the formula may be bonded is unsubstituted, and a hydrogen atom is bonded to the ring-forming atom.

[0039] In the above formulas (1) to (4), the aromatic hydrocarbon ring may be a single ring or a condensed ring. The number of ring-forming atoms in the aromatic hydrocarbon ring is 6 to 14, preferably 6 to 10, and more preferably 6. Specific examples of aromatic hydrocarbon rings having 6 to 14 ring-forming atoms include, but are not limited to, a benzene ring, a naphthalene ring, an anthracene ring, and a phenanthrene ring. Among these, a benzene ring is preferred.

[0040] In the above formulas (1) to (4), the aromatic heterocycle may be a single ring or a condensed ring. The aromatic heterocycle may be a ring having one or more heteroatoms (e.g., nitrogen atom (N), oxygen atom (O), phosphorus atom (P), sulfur atom (S), silicon atom (Si), etc.) as ring-forming atoms, and the remaining ring-forming atoms are carbon atoms (C). Among these, N, O, or S is preferred, and N is more preferred. The number of ring-forming atoms in the aromatic heterocycle is 5 to 14, preferably 5 to 13. The number of ring-forming atoms in the aromatic heterocycle is more preferably 5 to 12, and even more preferably 5 to 10. The number of heteroatoms in the aromatic heterocycle is not particularly limited, but is preferably 1 to 3. The number of heteroatoms in the aromatic heterocycle is more preferably 1 to 2, and even more preferably 1. The aromatic heterocycle is not particularly limited, and examples thereof include a furan ring, a benzofuran ring, an isobenzofuran ring, a pyrrole ring, an indole ring, an isoindole ring, a thiophene ring, a benzothiophene ring, a benzo(c)thiophene ring, a selenophene ring, a benzoselenophene ring, a benzo(c)selenophene ring, an imidazole ring, a benzimidazole ring, a purine ring, a pyrazole ring, an indazole ring, an oxazole ring, a benzoxazole ring, an isoxazole ring, a benzisoxazole ring, a thiazole ring, a benzothiazole ring, a pyridine ring, a quinoline ring, an isoquinoline ring, a pyrazine ring, a quinoxaline ring, an acridine ring, a pyrimidine ring, a quinazoline ring, a pyridazine ring, a cinnoline ring, a phthalazine ring, a 1,2,3-triazine ring, a 1,2,4-triazine ring, a 1,3,5-triazine ring, a dibenzofuran ring, and a dibenzothiophene ring. Among these, a pyridine ring, a pyridazine ring, a pyrimidine ring, or a pyrazine ring is preferable.

[0041] In order to more efficiently obtain the effects of the present invention, in one embodiment of the present invention, Ar 1 is preferably a benzene ring, a pyridine ring, a pyridazine ring, a pyrimidine ring, or a pyrazine ring. 1 ~Ar 5More preferably, all of are benzene rings.

[0042] In order to more efficiently obtain the effects of the present invention, in one embodiment of the present invention, Ar 31 is preferably a benzene ring, a pyridine ring, a pyridazine ring, a pyrimidine ring, or a pyrazine ring. 31 ~Ar 35 More preferably, all of are benzene rings.

[0043] In order to more efficiently obtain the effects of the present invention, in one embodiment of the present invention, Ar 41 is preferably a benzene ring, a pyridine ring, a pyridazine ring, a pyrimidine ring, or a pyrazine ring. 41 ~Ar 45 More preferably, all of are benzene rings.

[0044] In the above formulas (1) to (4), the alkyl group may be linear, branched, or cyclic, but is preferably linear or branched. The number of carbon atoms in the alkyl group is not particularly limited, but is preferably 1 or more. The number of carbon atoms in the alkyl group is preferably 20 or less, more preferably 10 or less, and even more preferably 4 or less. Specific examples of the alkyl group are not particularly limited, but include methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, isobutyl, 2-ethylbutyl, 3,3-dimethylbutyl, n-pentyl, isopentyl, neopentyl, tert-pentyl, cyclopentyl, 1-methylpentyl, 3-methylpentyl, 2-ethylpentyl, 4-methyl-2-pentyl, n-hexyl, 1-methylhexyl, 2-ethyl ... Examples of such groups include an aryl group, an arylhexyl group, a 2-butylhexyl group, a cyclohexyl group, a 4-methylcyclohexyl group, a 4-tert-butylcyclohexyl group, an n-heptyl group, a 1-methylheptyl group, a 2,2-dimethylheptyl group, a 2-ethylheptyl group, a 2-butylheptyl group, an n-octyl group, a tert-octyl group, a 2-ethyloctyl group, a 2-butyloctyl group, a 2-hexyloctyl group, a 3,7-dimethyloctyl group, a cyclooctyl group, an n-nonyl group, an n-decyl group, and an adamantyl group.

[0045] In the above formula (1) to formula (4), the haloalkyl group may be linear, branched, or cyclic, but is preferably linear or branched. The number of carbon atoms in the haloalkyl group is not particularly limited, but is preferably 1 or more. The number of carbon atoms in the haloalkyl group is preferably 20 or less, more preferably 10 or less, and even more preferably 4 or less. Specific examples of the haloalkyl group are not particularly limited, but include groups in which at least one hydrogen atom of the alkyl group exemplified above is substituted with a halogen atom. The halogen atom may be any of a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. More specific examples include a fluoromethyl group, a difluoromethyl group, a trifluoromethyl group, a chloromethyl group, a dichloromethyl group, a trichloromethyl group, a bromomethyl group, a dibromomethyl group, a tribromomethyl group, an iodomethyl group, a diiodomethyl group, a triiodomethyl group, a fluoroethyl group, a chloroethyl group, a bromoethyl group, and an iodoethyl group.

[0046] In the above formulas (1) to (4), the alkoxy group may be linear, branched, or cyclic, but is preferably linear or branched. The number of carbon atoms in the alkoxy group is not particularly limited, but is preferably 1 or more. The number of carbon atoms in the alkoxy group is preferably 20 or less, more preferably 10 or less, and even more preferably 4 or less. Specific examples of the alkoxy group are not particularly limited, but include methoxy, ethoxy, n-propyloxy, isopropyloxy, n-butyloxy, sec-butyloxy, tert-butyloxy, isobutyloxy, 2-ethylbutyloxy, 3,3-dimethylbutyloxy, n-pentyloxy, isopentyloxy, neopentyloxy, tert-pentyloxy, cyclopentyloxy, 1-methylpentyloxy, 3-methylpentyloxy, 2-ethylpentyloxy, 4-methyl-2-pentyloxy, n-hexyloxy, 1-methylhexyloxy, 2-ethyl ... Examples of such groups include an n-hexyloxy group, a 2-butylhexyloxy group, a cyclohexyloxy group, a 4-methylcyclohexyloxy group, a 4-tert-butylcyclohexyloxy group, an n-heptyloxy group, a 1-methylheptyloxy group, a 2,2-dimethylheptyloxy group, a 2-ethylheptyloxy group, a 2-butylheptyloxy group, an n-octyloxy group, a tert-octyloxy group, a 2-ethyloctyloxy group, a 2-butyloctyloxy group, a 2-hexyloctyloxy group, a 3,7-dimethyloctyloxy group, a cyclooctyloxy group, an n-nonyloxy group, an n-decyloxy group, and an adamantyloxy group.

[0047] In the above formulas (1) to (4), the aryl group represents a group derived from a hydrocarbon ring having aromaticity in part or as a whole. When the aryl group contains two or more hydrocarbon rings having aromaticity in part or as a whole, these rings may be bonded to each other by a single bond or condensed. When the aryl group contains two or more hydrocarbon rings having aromaticity in part or as a whole, one atom may also serve as a ring-forming atom of any two of these rings. The number of carbon atoms in the aryl group is not particularly limited, but is preferably 6 to 30. The number of carbon atoms in the aryl group is more preferably 6 to 12, and even more preferably 6. Specific examples of the aryl group include, but are not particularly limited to, a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a fluorenyl group, an anthracenyl group, a terphenyl group, a quaterphenyl group, a quinquephenyl group, a sexiphenyl group, a triphenylenyl group, a pyrenyl group, a benzofluorenyl group, a chrysenyl group, and groups consisting of combinations thereof. Among these, a phenyl group is preferable.

[0048] In the above formulas (1) to (4), the heteroaryl group represents a group derived from a heterocycle having aromaticity in part or as a whole. When the heteroaryl group contains two or more heterocycles having aromaticity in part or as a whole, these rings may be bonded to each other in part or as a whole by a single bond. When the heteroaryl group contains two or more heterocycles having aromaticity in part or as a whole, or other rings, these rings may be condensed with each other. In addition, when the heteroaryl group contains two or more heterocycles having aromaticity in part or as a whole, or other rings, one atom may also serve as a ring-forming atom of these rings. The heteroatom contained in the heteroaryl group is not particularly limited, and examples thereof include one or more heteroatoms (e.g., nitrogen atom (N), oxygen atom (O), phosphorus atom (P), sulfur atom (S), silicon atom (Si), selenium atom (Se), germanium atom (Ge)) as ring-forming atoms. The number of carbon atoms in the heteroaryl group is preferably 3 to 30. The number of ring-forming atoms in the heteroaryl group is not particularly limited, but is preferably 5 to 30. The number of ring-forming atoms in the heteroaryl group is more preferably 5 to 14, and even more preferably 5 to 13. The number of heteroatoms in the heteroaryl group is not particularly limited, but is preferably 1 to 3. The number of heteroatoms in the heteroaryl group is more preferably 1 to 2, and even more preferably 1.Specific examples of the heteroaryl group include, but are not limited to, a thienyl group, a furanyl group, a pyronyl group, an imidazolyl group, a thiazolyl group, an oxazolyl group, an oxadiazolyl group, a triazolyl group, a pyridyl group, a bipyridyl group, a pyrimidyl group, a triazinyl group, a triazolyl group, an acridinyl group, a pyridazinyl group, a pyridinyl group, a quinolinyl group, a quinazolinyl group, a quinoxalinyl group, a phenoxazinyl group, a phthalazinyl group, a pyridopyrimidinyl group, a pyridopyrazinyl group, a pyrazinopyrazinyl group, an isoquinolinyl group, a phenyl ... Examples of the alkyl group include an aryl group, an indolyl group, a carbazolyl group, a benzoxazolyl group, a benzimidazolyl group, a benzothiazolyl group, a benzocarbazolyl group, a benzothiophenyl group, a dibenzothiophenyl group, a thienothiophenyl group, a benzofuranyl group, a phenanthrolinyl group, a thiazolyl group, an isoxazolyl group, an oxadiazolyl group, a thiadiazolyl group, a phenothiazinyl group, a dibenzosilolyl group, a dibenzofuranyl group, a xanthonyl group, and groups formed from combinations thereof.

[0049] In the above formulas (1) to (4), the number of carbon atoms in the aryloxy group is not particularly limited, but is preferably 6 or more and 30 or less. The number of carbon atoms in the aryloxy group is more preferably 6 or more and 12 or less, and even more preferably 6. Specific examples of the aryloxy group are not particularly limited, but include a phenyloxy group, a biphenyloxy group, a terphenyloxy group, a naphthyloxy group, a fluorenyloxy group, an anthracenyloxy group, a terphenyloxy group, a quaterphenyloxy group, a quinquephenyloxy group, a triphenylenyloxy group, a pyrenyloxy group, a benzofluorenyloxy group, a chrysenyloxy group, and groups consisting of combinations thereof.

[0050] In the above formulas (1) to (4), the number of carbon atoms in the arylthio group is not particularly limited, but is preferably 6 or more and 30 or less. The number of carbon atoms in the arylthio group is more preferably 6 or more and 12 or less, and even more preferably 6. Specific examples of the arylthio group are not particularly limited, but include a phenylthio group, a biphenylthio group, a terphenylthio group, a naphthylthio group, a fluorenylthio group, an anthracenylthio group, a terphenylthio group, a quaterphenylthio group, a quinquephenylthio group, a triphenylenylthio group, a pyrenylthio group, a benzofluorenylthio group, a chrysenylthio group, and groups consisting of combinations thereof.

[0051] In the above formulas (1) to (4), the heteroatoms as ring-forming atoms of the heteroaryloxy group are not particularly limited, but examples thereof include a nitrogen atom (N), an oxygen atom (O), a phosphorus atom (P), a sulfur atom (S), and a silicon atom (Si). The number of ring-forming atoms of the heteroaryloxy group is not particularly limited, but is preferably 5 to 30. The number of ring-forming atoms of the heteroaryloxy group is more preferably 5 to 14, and even more preferably 5 to 13. The number of heteroatoms as ring-forming atoms of the heteroaryloxy group is not particularly limited, but is preferably 1 to 3. The number of heteroatoms as ring-forming atoms of the heteroaryloxy group is more preferably 1 to 2, and even more preferably 1. Specific examples of the heteroaryloxy group include, but are not limited to, a thienyloxy group, a furanyloxy group, a pyronyloxy group, an imidazolyloxy group, a thiazolyloxy group, an oxazolyloxy group, an oxadiazolyloxy group, a triazolyloxy group, a pyridyloxy group, a bipyridyloxy group, a pyrimidyloxy group, a triazinyloxy group, a triazolyloxy group, an acridinyloxy group, a pyridazinyloxy group, a pyridinyloxy group, a quinolinyloxy group, a quinazolinyloxy group, a quinoxalinyloxy group, a phenoxazinyloxy group, a phthalazinyloxy group, a pyridopyrimidinyloxy group, a pyridopyrazinyloxy group, a pyrazinopyra group, a phenyloxy ... Examples of the alkyl group include a dinyloxy group, an isoquinolinyloxy group, an indolyloxy group, a carbazolyloxy group, a benzoxazolyloxy group, a benzimidazolyloxy group, a benzothiazolyloxy group, a benzocarbazolyloxy group, a benzothiophenyloxy group, a dibenzothiophenyloxy group, a thienothiophenyloxy group, a benzofuranyloxy group, a phenanthrolinyloxy group, a thiazolyloxy group, an isoxazolyloxy group, an oxadiazolyloxy group, a thiadiazolyloxy group, a phenothiazinyloxy group, a dibenzosilolyloxy group, a dibenzofuranyloxy group, a xanthonyloxy group, and a group consisting of a combination thereof.

[0052] In the above formulas (1) to (4), the heteroatoms as ring-forming atoms of the heteroarylthio group are not particularly limited, but examples thereof include a nitrogen atom (N), an oxygen atom (O), a phosphorus atom (P), a sulfur atom (S), and a silicon atom (Si). The number of ring-forming atoms of the heteroarylthio group is not particularly limited, but is preferably 5 to 30. The number of ring-forming atoms of the heteroarylthio group is more preferably 5 to 14, and even more preferably 5 to 13. The number of heteroatoms as ring-forming atoms of the heteroarylthio group is not particularly limited, but is preferably 1 to 3. The number of heteroatoms as ring-forming atoms of the heteroarylthio group is more preferably 1 to 2, and even more preferably 1. Specific examples of the heteroarylthio group include, but are not limited to, a thienylthio group, a furanylthio group, a pyronylthio group, an imidazolylthio group, a thiazolylthio group, an oxazolylthio group, an oxadiazolylthio group, a triazolylthio group, a pyridylthio group, a bipyridylthio group, a pyrimidylthio group, a triazinylthio group, a triazolylthio group, an acridinylthio group, a pyridazinylthio group, a pyridinylthio group, a quinolinylthio group, a quinazolinylthio group, a quinoxalinylthio group, a phenoxazinylthio group, a phthalazinylthio group, a pyridopyrimidinylthio group, a pyridopyrazinylthio group, a pyrazinopyrazinyi ... Examples of such a group include an arylthio group, an isoquinolinylthio group, an indolylthio group, a carbazolylthio group, a benzoxazolylthio group, a benzimidazolylthio group, a benzothiazolylthio group, a benzocarbazolylthio group, a benzothiophenylthio group, a dibenzothiophenylthio group, a thienothiophenylthio group, a benzofuranylthio group, a phenanthrolinylthio group, a thiazolylthio group, an isoxazolylthio group, an oxadiazolylthio group, a thiadiazolylthio group, a phenothiazinylthio group, a dibenzosilolylthio group, a dibenzofuranylthio group, a xanthonylthio group, and groups consisting of combinations thereof.

[0053] In the above formulas (1) to (4), the halogen atom is not particularly limited, but examples thereof include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc. Among these, a fluorine atom is preferable.

[0054] In the above formulas (1) to (4), the amino group is -NH 2 It may be a group, a monosubstituted amino group represented by -NHR, or a disubstituted amino group represented by -NRR' (wherein R and R' are organic groups). Here, R and R' are not particularly limited, but examples thereof include substituted or unsubstituted alkyl groups, substituted or unsubstituted alkenyl groups, substituted or unsubstituted alkynyl groups, substituted or unsubstituted aryl groups, and substituted or unsubstituted heteroaryl groups. R and R' may be the same or different.

[0055] The alkyl group, alkenyl group, and alkynyl group in R and R' may each be linear, branched, or cyclic, but are preferably linear. The number of carbon atoms in the alkyl group is not particularly limited, but is preferably 1 or more. The number of carbon atoms in the alkenyl group and alkynyl group is not particularly limited, but is preferably 2 or more. The number of carbon atoms in the alkyl group, alkenyl group, and alkynyl group is preferably 20 or less, more preferably 10 or less, and even more preferably 4 or less. Specific examples of the alkyl group include, but are not limited to, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, an isobutyl group, a 2-ethylbutyl group, a 3,3-dimethylbutyl group, an n-pentyl group, an isopentyl group, a neopentyl group, a tert-pentyl group, a cyclopentyl group, a 1-methylpentyl group, a 3-methylpentyl group, a 2-ethylpentyl group, a 4-methyl-2-pentyl group, an n-hexyl group, a 1-methylhexyl group, a 2-ethyl ... Examples of such groups include an aryl group, an arylhexyl group, a 2-butylhexyl group, a cyclohexyl group, a 4-methylcyclohexyl group, a 4-tert-butylcyclohexyl group, an n-heptyl group, a 1-methylheptyl group, a 2,2-dimethylheptyl group, a 2-ethylheptyl group, a 2-butylheptyl group, an n-octyl group, a tert-octyl group, a 2-ethyloctyl group, a 2-butyloctyl group, a 2-hexyloctyl group, a 3,7-dimethyloctyl group, a cyclooctyl group, an n-nonyl group, an n-decyl group, and an adamantyl group. Specific examples of alkenyl groups include, but are not limited to, vinyl, 2-propenyl, 2-butenyl, 3-butenyl, 1-methyl-2-propenyl, 2-methyl-2-propenyl, 2-pentenyl, 3-pentenyl, 4-pentenyl, 1-methyl-2-butenyl, 2-methyl-2-butenyl, 3-methyl-2-butenyl, 1-methyl-3-butenyl, 2-methyl-3-butenyl, 3-methyl-3-butenyl, 1,1-dimethyl-2-propenyl, 1,2-dimethyl-2-propenyl, and 1-ethyl-2-propenyl groups.Specific examples of the alkynyl group include, but are not limited to, a 2-butynyl group, a 3-pentynyl group, a hexynyl group, a heptynyl group, an octynyl group, and a decynyl group.

[0056] The aryl group in R and R' is the same as described above. In addition, the aryl group in R and R' is preferably a monovalent group derived from an aromatic hydrocarbon ring having 6 or more ring atoms. In addition, the aromatic hydrocarbon ring having 6 or more ring atoms is the same as described above.

[0057] The heteroaryl group in R and R' is the same as described above. In addition, the heteroaryl group is preferably a monovalent group derived from an aromatic heterocycle having 5 or more ring atoms. In addition, the aromatic heterocycle having 5 or more ring atoms is the same as described above.

[0058] The amino group is preferably a disubstituted amino group represented by -NRR', and in this case, R and R' are each preferably independently an aryl group or a heteroaryl group. That is, the amino group is preferably an N,N-diarylamino group, an N,N-diheteroarylamino group, or an N-aryl-N-heteroarylamino group. R and R' are each more preferably independently a monovalent group derived from an aromatic hydrocarbon ring having 6 to 30 ring atoms, or a monovalent group derived from an aromatic heterocycle having 5 to 30 ring atoms. R and R' are more preferably a monovalent group derived from an aromatic hydrocarbon ring having 6 to 30 ring atoms. Here, the preferred number of ring atoms and specific examples of the aromatic hydrocarbon ring are also the same as those explained above. The preferred number of ring atoms and specific examples of the aromatic heterocycle are also the same as those explained above. Among these, an N,N-diphenylamino group is particularly preferred.

[0059] From the viewpoint of obtaining the effects of the present invention more efficiently, in the above formula (1) and formula (2), R 1 ~R 5At least one of the groups is preferably a deuterium atom, a halogen atom, a linear or branched unsubstituted alkyl group having 1 to 20 carbon atoms, a linear or branched unsubstituted haloalkyl group having 1 to 20 carbon atoms, a linear or branched unsubstituted alkoxy group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, a substituted or unsubstituted heteroaryl group having 3 to 30 carbon atoms, or a disubstituted amino group represented by -NRR'. In this case, R and R' are preferably each independently a monovalent group derived from an aromatic hydrocarbon ring having 6 to 30 ring atoms or a monovalent group derived from an aromatic heterocycle having 5 to 30 ring atoms. In addition, R 1 ~R 5 It is more preferable that at least one of them is a deuterium atom, a halogen atom, a linear or branched unsubstituted alkyl group having from 1 to 20 carbon atoms, or a substituted or unsubstituted aryl group having from 6 to 30 carbon atoms.

[0060] From the viewpoint of obtaining the effects of the present invention more efficiently, in the above formula (3), R 31 ~R 35 At least one of the groups is preferably a deuterium atom, a halogen atom, a linear or branched unsubstituted alkyl group having 1 to 20 carbon atoms, a linear or branched unsubstituted haloalkyl group having 1 to 20 carbon atoms, a linear or branched unsubstituted alkoxy group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, a substituted or unsubstituted heteroaryl group having 3 to 30 carbon atoms, or a disubstituted amino group represented by -NRR'. In this case, R and R' are preferably each independently a monovalent group derived from an aromatic hydrocarbon ring having 6 to 30 ring atoms or a monovalent group derived from an aromatic heterocycle having 5 to 30 ring atoms. In addition, R 1 ~R 5 It is more preferable that at least one of them is a deuterium atom, a halogen atom, a linear or branched unsubstituted alkyl group having from 1 to 20 carbon atoms, or a substituted or unsubstituted aryl group having from 6 to 30 carbon atoms.

[0061] From the viewpoint of obtaining the effects of the present invention more efficiently, in the above formula (4), R 41 ~R 45 At least one of the groups is preferably a deuterium atom, a halogen atom, a linear or branched unsubstituted alkyl group having 1 to 20 carbon atoms, a linear or branched unsubstituted haloalkyl group having 1 to 20 carbon atoms, a linear or branched unsubstituted alkoxy group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, a substituted or unsubstituted heteroaryl group having 3 to 30 carbon atoms, or a disubstituted amino group represented by -NRR'. In this case, R and R' are preferably each independently a monovalent group derived from an aromatic hydrocarbon ring having 6 to 30 ring atoms or a monovalent group derived from an aromatic heterocycle having 5 to 30 ring atoms. In addition, R 1 ~R 5 It is more preferable that at least one of them is a deuterium atom, a halogen atom, a linear or branched unsubstituted alkyl group having from 1 to 20 carbon atoms, or a substituted or unsubstituted aryl group having from 6 to 30 carbon atoms.

[0062] R in the above formulas (1) to (4) 1 ~R 5 , R 31 ~R 35 and R 41 ~R 45In the above, the alkyl group, the haloalkyl group, the aryl group, the heteroaryl group, the aryloxy group, the heteroaryloxy group, the arylthio group, the heteroarylthio group, and the amino group may each be a substituted group. The substituent is not particularly limited, and examples thereof include an alkyl group, an alkenyl group, an alkynyl group, a deuterium atom, a halogen atom, a cyano group, and an alkyl group substituted with a deuterium atom. Among these, the substituent is preferably an alkyl group, and more preferably a methyl group, a tert-butyl group, or a fluorine atom. And, the substituent is further preferably a methyl group or a fluorine atom. In addition, in the above formulas (1) to (4), when the amino group is a mono-substituted amino group or a di-substituted amino group, and a substituent is bonded to the alkyl group, the alkenyl group, or the alkynyl group constituting the amino group, examples of the substituent include a deuterium atom, a halogen atom, and a cyano group. When the amino group is a mono- or di-substituted amino group, and a substituent is bonded to the aryl group or heteroaryl group constituting the amino group, examples of the substituent include an alkyl group, an alkenyl group, an alkynyl group, a deuterium atom, a halogen atom, a cyano group, and an alkyl group substituted with a deuterium atom. When the amino group is an N,N-diarylamino group, an N,N-diheteroarylamino group, or an N-aryl-N-heteroarylamino group, examples of the substituent include an alkyl group, an alkenyl group, an alkynyl group, a deuterium atom, a halogen atom, a cyano group, and an alkyl group substituted with a deuterium atom. In this case, the substituent is preferably an alkyl group or a halogen atom, and more preferably a methyl group, a tert-butyl group, or a fluorine atom. And, the substituent is more preferably a methyl group or a fluorine atom. The alkyl group that is the base of the alkyl group, alkenyl group, alkynyl group, halogen atom, and alkyl group substituted with a deuterium atom as the substituent is the same as described above.

[0063] In addition, the above-mentioned substituents do not substitute the same kind of group. For example, the substituent substituting an alkyl group does not include an alkyl group. Also, for example, the substituent substituting a haloalkyl group does not include an alkyl group or a halogen atom.

[0064] R in the above formulas (1) to (4) 1 ~R 5 , R 31 ~R 35 and R 41 ~R 45 Particularly preferred examples of R include a fluorine atom, a methyl group, a tert-butyl group, a phenyl group, a tert-butylphenyl group, and a 2,4,6-trimethylphenyl group. However, R 1 ~R 5 , R 31 ~R 35 and R 41 ~R 45 are not limited to these.

[0065] The HOMO level of the fused ring compound according to one embodiment of the present invention is not particularly limited, but is preferably -6.5 eV or more. The HOMO level is more preferably -6.3 eV or more. In this range, the driving voltage of the organic EL device is further reduced. In addition, from the viewpoint of matching with the energy diagram of other general materials constituting the light-emitting layer and from the viewpoint of stability in the atmosphere, the HOMO level is preferably -5.0 eV or less.

[0066] The LUMO level of the fused ring compound according to one embodiment of the present invention is not particularly limited, but is preferably -2.5 eV or less. The LUMO level is more preferably -2.6 eV or less. In this range, the driving voltage of the organic EL device is further reduced. From the viewpoint of matching with the energy diagram of other general materials constituting the light-emitting layer, the LUMO level is preferably -4.0 eV or more.

[0067] The HOMO level can be measured and calculated using an atmospheric photoelectron spectrometer, and the LUMO level can be measured and calculated using an atmospheric photoelectron spectrometer and a spectrophotometer. Details of the measurement and calculation methods will be described in the Examples.

[0068] The peak wavelength of the photoluminescence (PL) of the fused ring compound according to one embodiment of the present invention is not particularly limited, but is preferably 430 nm or more. The peak wavelength is more preferably 435 nm or more, and even more preferably 440 nm or more. The peak wavelength is preferably 500 nm or less, more preferably 490 nm or less, and even more preferably 480 nm or less. Within these ranges, the color of blue light emission becomes better.

[0069] The half-width (FWHM) at which the emission intensity is reduced to half at the peak having the peak wavelength in the PL of the fused ring compound according to one embodiment of the present invention is preferably smaller (narrower). Specifically, the half-width is preferably 45 nm or less, more preferably 40 nm or less, and even more preferably 35 nm or less. Within these ranges, the color purity of the emission is further improved.

[0070] The PL peak wavelength and the PL half-width can be measured and calculated using a spectrofluorophotometer. Details of the measurement and calculation methods will be described in the Examples.

[0071] ΔE is a value obtained by subtracting the triplet energy T1 of the phosphorescence spectrum from the singlet energy S1 of the fluorescence spectrum of the fused ring compound according to one embodiment of the present invention. ST The smaller the value, the more preferable. ST is preferably 0.5 eV or less, more preferably 0.4 eV or less, and even more preferably 0.3 eV or less. Within these ranges, the luminous efficiency is further improved.

[0072] Singlet energy S1, triplet energy T1 and ΔE STcan be measured and calculated by measuring the fluorescence spectrum and phosphorescence spectrum at 77 K using a spectrofluorometer. Details of the measurement and calculation methods will be described in the Examples.

[0073] More specific examples of the compound represented by the above formula (3) (compounds 1 to 22) are shown below, however, the present invention is not limited to these specific examples.

[0074] [ka]

[0075] [ka]

[0076] Here, in the above compounds 16 and 17, Ph represents an unsubstituted phenyl group.

[0077] Further, more specific examples of the compound represented by the above formula (4) (compounds 23 to 27) are shown below, however, the present invention is not limited to these specific examples.

[0078] [ka]

[0079] Among these compounds 1 to 27, compounds 1, 2 and 3 are preferred.

[0080] The synthesis method of the fused ring compound according to one embodiment of the present invention is not particularly limited, and can be synthesized based on the knowledge of known synthesis methods. More specifically, it can be synthesized according to the method described in the examples or the method described in the examples. For example, it can be synthesized by changing the raw materials, reaction conditions, etc., adding or removing some steps, or appropriately combining known synthesis methods in the methods described in the examples.

[0081] The method for confirming the structure of the fused ring compound according to one embodiment of the present invention is not particularly limited. The structure of the nitrogen-containing fused ring compound according to the present invention can be confirmed, for example, by a known method (e.g., NMR, LC-MS, etc.).

[0082] <Organic electroluminescence element> Another aspect of the present invention relates to an organic electroluminescence device having an organic layer containing the above-mentioned fused ring compound. Such an organic electroluminescence device can realize light emission with a narrow emission spectrum and high color purity, and can also realize high luminous efficiency.

[0083] The organic EL element according to the present embodiment will be described in detail below with reference to the drawings. Figures 1 to 3 are schematic diagrams showing the organic electroluminescence element according to the present embodiment.

[0084] 1 to 3 are cross-sectional schematic diagrams showing an organic electroluminescence element according to one embodiment of the present invention, however, the structure of the organic electroluminescence element according to the present invention is not limited to the forms shown in FIGS.

[0085] 1 is a schematic cross-sectional view showing an organic electroluminescence element according to one embodiment of the present invention. An organic electroluminescence element 10 according to one embodiment of the present invention includes a substrate 1, a first electrode 2, a hole transport region 3, an emitting layer 4, an electron transport region 5, and a second electrode 6, which are laminated in this order.

[0086] Fig. 2 is a cross-sectional schematic diagram showing an organic electroluminescence element according to another embodiment of the present invention. An organic electroluminescence element 10 according to one embodiment of the present invention includes a substrate 1, a first electrode 2, a hole transport region 3, a light-emitting layer 4, an electron transport region 5, and a second electrode 6, which are stacked in this order. In Fig. 2, the hole transport region 3 includes a hole injection layer 31 and a hole transport layer 32, which are stacked in this order. Also, in Fig. 2, the electron transport region 5 includes an electron transport layer 52 and an electron injection layer 51, which are stacked in this order.

[0087] Fig. 3 is a cross-sectional schematic diagram showing an organic electroluminescence element according to another embodiment of the present invention. An organic electroluminescence element 10 according to one embodiment of the present invention includes a substrate 1, a first electrode 2, a hole transport region 3, a light-emitting layer 4, an electron transport region 5, and a second electrode 6, which are stacked in this order. In Fig. 3, the hole transport region 3 includes a hole injection layer 31, a hole transport layer 32, and an electron blocking layer 33, which are stacked in this order. Also, in Fig. 3, the electron transport region 5 includes a hole blocking layer 53, an electron transport layer 52, and an electron injection layer 51, which are stacked in this order.

[0088] The fused ring compound according to the present invention is contained, for example, in any of the organic layers disposed between the first electrode 2 and the second electrode 6. Examples of the organic layers include a hole injection layer 31, a hole transport layer 32, an emitting layer 4, an electron transport layer 52, and an electron injection layer 51. It is more preferable that the fused ring compound according to the present invention is contained in the emitting layer 4.

[0089] An embodiment of the present invention includes, for example, an organic electroluminescent device including a first electrode, a second electrode, and one or more light-emitting layers. The second electrode is preferably disposed on top of the first electrode.

[0090] In this specification, when a layer, film, region, plate, or other part is described as being "on" or "above" another part, this includes not only when it is "directly above" the other part, but also when there is another part in between. Conversely, when a layer, film, region, plate, or other part is described as being "below" or "below" another part, this includes not only when it is "directly below" the other part, but also when there is another part in between. In addition, in this specification, being "located on" includes not only when it is on the top, but also when it is located on the bottom or lower surface.

[0091] As described above, the fused ring compound according to the present invention is preferably contained in the light-emitting layer. The following describes the embodiment in which the fused ring compound according to the present invention is contained in the light-emitting layer. The fused ring compound according to the present invention contained in the light-emitting layer may be one type alone or two or more types in combination.

[0092] <Light-emitting layer> The light-emitting layer may be a single layer made of a single material, a single layer made of multiple different materials, or a multi-layer structure having multiple layers made of multiple different materials.

[0093] The light-emitting layer is not particularly limited, and may contain, for example, a host material and a dopant material. The above-mentioned fused ring compound may be used as either a host material or a dopant material, but is preferably used as a dopant material.

[0094] Furthermore, the light-emitting layer may contain a known host material. Examples of the host material include at least one of DPEPO (bis[2-(diphenylphosphino)phenyl]ether oxide), CBP (4,4'-bis(carbazol-9-yl)biphenyl), mCBP (3,3'-bis(carbazol-9-yl)biphenyl), mCP (1,3-bis(carbazol-9-yl)benzene), PPF (2,8-bis(diphenylphosphoryl)dibenzo[b,d]furan), TcTa (4,4',4''-tris(carbazol-9-yl)triphenylamine), and TPBi (1,3,5-tris(N-phenylbenzimidazol-2-yl)benzene). However, the host material may be, but is not limited to, Alq 3(tris(8-hydroxyquinolino)aluminum), PVK (poly(n-vinylcarbazole), ADN (9,10-di(naphthalen-2-yl)anthracene), TCTA (4,4',4"-tris(carbazol-9-yl)-triphenylamine), TPBi (1,3,5-tris(N-phenylbenzimidazol-2-yl)benzene), TBADN (3-tert-butyl-9,10-di(naphth-2-yl)anthracene), anthracene), DSA (distyrylarylene), CDBP (4,4'-bis(9-carbazolyl)-2,2'-dimethyl-biphenyl), MADN (2-methyl-9,10-bis(naphthalen-2-yl)anthracene), DPEPO (bis[2-(diphenylphosphino)phenyl]ether oxide), CP1 (hexaphenylcyclotriphosphazene), UGH2 (1,4-bis(triphenylsilyl)benzene), DPSiO 3 (Hexaphenylcyclotrisiloxane), DPSiO 4 (octaphenylcyclotetrasiloxane), PPF (2,8-bis(diphenylphosphoryl)dibenzofuran), etc.

[0095] The light-emitting layer may also contain a known dopant material. For example, styryl derivatives (e.g., 1,4-bis[2-(3-N-ethylcarbazolyl)vinyl]benzene (BCzVB), 4-(di-p-tolylamino)-4'-[(di-p-tolylamino)styryl]stilbene (DPAVB), N-(4-((E)-2-(6-((E)-4-(diphenylamino)styryl)naphthalen-2-yl)vinyl)phenyl)-N-phenylbenzenamine (N-BDAVBi), perylene and its derivatives (e.g., 2,5,8,11-tetra-tert-butylperylene (TBP)), pyrene and its derivatives (e.g., 1,1-dipyrene, 1,4-dipyrenylbenzene, 1,4-bis(N,N-diphenylamino)pyrene), 2,5,8,11-tetra-tert-butylperylene (TBP)), and the like may be included.

[0096] The thickness of the light-emitting layer is not particularly limited, but is preferably from 1 nm to 100 nm, and more preferably from 10 nm to 70 nm.

[0097] The method for forming the light-emitting layer is not particularly limited, and examples thereof include known film-forming methods such as vacuum deposition, spin coating, LB (Langmuir-Blodgett) method, inkjet printing, laser printing, and laser thermal transfer (Laser Induced Thermal Imaging, LITI).

[0098] The emission wavelength of the organic electroluminescence element is not particularly limited. However, it is preferable that the organic electroluminescence element emits light having a peak in the wavelength region of 430 nm or more and 500 nm or less. In addition, it is more preferable that the organic electroluminescence element emits light having a peak in the wavelength region of 435 nm or more and 490 nm or less, and it is even more preferable that the organic electroluminescence element emits light having a peak in the wavelength region of 440 nm or more and 480 nm or less.

[0099] In addition, the smaller the full width at half maximum (FWHM) of the emission spectrum of the organic electroluminescence element, the more preferable. In addition, the full width at half maximum (FWHM) of the emission spectrum is preferably 45 nm or less, more preferably 40 nm or less, and even more preferably 35 nm or less (lower limit greater than 0 nm).

[0100] Further, each region and layer other than the light-emitting layer will be described in detail below.

[0101] (Substrate 1) The organic electroluminescence element 10 may have a substrate 1. A substrate used in a general organic electroluminescence element can be used as the substrate 1. For example, the substrate 1 may be a glass substrate, a semiconductor substrate such as a silicon substrate, a transparent plastic substrate, or the like.

[0102] (1st electrode 2) The first electrode 2 has electrical conductivity. In the organic electroluminescence element according to one embodiment of the present invention, the first electrode 2 is preferably a positive electrode. The first electrode 2 is preferably a pixel electrode. The first electrode 2 is preferably a transmissive electrode, a semi-transmissive electrode, or a reflective electrode.

[0103] The material constituting the first electrode 2 is not particularly limited, and examples thereof include metals, metal alloys, conductive compounds, etc. If the first electrode 2 is a transmissive electrode, the first electrode 2 preferably contains a transparent metal oxide, such as ITO (indium tin oxide), IZO (indium zinc oxide), ZnO (zinc oxide), ITZO (indium tin zinc oxide), etc. If the first electrode 2 is a semi-transmissive electrode or a reflective electrode, the first electrode 2 preferably contains Ag, Mg, Cu, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, LiF / Ca, LiF / Al, Mo, Ti, or a compound or mixture thereof (for example, a mixture of Ag and Mg), etc.

[0104] The first electrode 2 may be a single layer made of a single material, a single layer made of multiple different materials, or a multi-layer structure having multiple layers made of multiple different materials.

[0105] The thickness of the first electrode 2 is not particularly limited, but is preferably 10 nm or more and 1000 nm or less, and more preferably 100 nm or more and 300 nm or less.

[0106] (Hole transport region 3) A hole transport region 3 is provided on the first electrode 2. The hole transport region 3 includes at least one of a hole injection layer 31, a hole transport layer 32, a hole buffer layer (not shown), and an electron blocking layer 33.

[0107] The hole transport region 3 may be a single layer made of a single material, a single layer made of multiple different materials, or a multi-layer structure having multiple layers made of multiple different materials.

[0108] For example, the hole transport region 3 may have a structure of a single layer of a hole injection layer 31 or a hole transport layer 32. For example, the hole transport region 3 may have a structure of a single layer formed of a hole injection material and a hole transport material. For example, the hole transport region 3 may have a structure of a hole injection layer 31 / hole transport layer 32 stacked in order from the first electrode 2. For example, the hole transport region 3 may have a structure of a hole injection layer 31 / hole transport layer 32 / hole buffer layer (not shown). For example, the hole transport region 3 may have a structure of a hole injection layer 31 / hole buffer layer (not shown) stacked in order from the first electrode 2. For example, the hole transport region 3 may have a structure of a hole transport layer 32 / hole buffer layer (not shown) stacked in order from the first electrode 2. Furthermore, for example, the hole transport region 3 may have a structure of a hole injection layer 31 / a hole transport layer 32 / an electron blocking layer 33, which are stacked in this order from the first electrode 2. However, the structure of the hole transport region is not limited to this.

[0109] The hole injection layer 31 and each layer constituting the hole transport region 3 are not particularly limited, and may contain, for example, a known hole injection material. Examples of hole injection materials include phthalocyanine compounds such as copper phthalocyanine, DNTPD (N,N'-diphenyl-N,N'-bis-[4-phenyl-m-tolyl-amino)-phenyl]-biphenyl-4,4'-diamine), m-MTDATA (4,4',4"-tris(3-methylphenylphenylamino)triphenylamine), TDATA (4,4',4"-tris(N,N-diphenylamino)triphenylamine), 2-TNATA (4,4',4"-tris{N,-(2-naphthyl)-N-phenylamino}-triphenylamine), PEDOT / PSS (poly(3,4-ethylenedioxythiophene) / poly(4-styrenesulfonyl)thioacetate), and the like. Examples of suitable polyaniline-containing ether ketones include polyaniline / dodecylbenzenesulfonate (PANI / DBSA), polyaniline / dodecylbenzenesulfonic acid (PANI / CSA), polyaniline / camphorsulfonic acid (PANI / PSS), polyaniline / poly(4-styrenesulfonate), NPB (N,N'-di(naphthalene-1-yl)-N,N'-diphenylbenzidine), triphenylamine-containing polyether ketone (TPAPEK), 4-isopropyl-4'-methyldiphenyliodonium tetrakis(pentafluorophenyl)borate, and HAT-CN (dipyrazino[2,3-f:2',3'-h]quinoxaline-2,3,6,7,10,11-hexacarbonitrile).

[0110] The hole transport layer 32 and each layer constituting the hole transport region 3 are not particularly limited, and may contain, for example, a known hole transport material. Examples of hole transport materials include carbazole derivatives such as N-phenylcarbazole and polyvinylcarbazole, fluorene derivatives, triphenylamine derivatives such as TPD (N,N'-bis(3-methylphenyl)-N,N'-diphenyl-[1,1-biphenyl]-4,4'-diamine) and TCTA (4,4',4"-tris(N-carbazolyl)triphenylamine), NPB (N,N'-di(naphthalene-1-yl) -N,N'-diphenyl-benzidine), TAPC (4,4'-cyclohexylidenebis[N,N-bis(4-methylphenyl)benzenamine]), HMTPD (4,4'-bis[N,N'-(3-tolyl)amino]-3,3'-dimethylbiphenyl), mCP (1,3-bis(carbazol-9-yl)benzene), the following compound HTP1, the following compound AD1, the following compound P-1, and the following compound FA-14.

[0111] [ka]

[0112] The hole transport region 3 may further contain a charge generating material to improve conductivity, in addition to the hole injection material and the hole transport material. The charge generating material is uniformly or non-uniformly dispersed in the hole transport region 3 or in each layer constituting the hole transport region 3. The charge generating material is not particularly limited, and examples thereof include known charge generating materials. Examples of the charge generating material include p-dopants. Examples of the p-dopants include quinone derivatives such as TCNQ (tetracyanoquinodimethane) and F4-TCNQ (2,3,5,6-tetrafluoro-tetracyanoquinodimethane), metal oxides such as tungsten oxide and molybdenum oxide, and cyano group-containing compounds.

[0113] The hole buffer layer (not shown) increases light emission efficiency by compensating for the resonance distance according to the wavelength of light emitted from the light emitting layer 4. The material contained in the hole buffer layer (not shown) is not particularly limited, and the material used in the hole buffer layer (not shown) can be used. For example, the compound that can be contained in the hole transport region 3 as described above can be used.

[0114] The electron blocking layer 33 is a layer that serves to prevent the injection of electrons from the electron transport region 5 to the hole transport region 3. There are no particular limitations on the material contained in the electron blocking layer 33, and any known material used for the electron blocking layer 33 can be used.

[0115] The thickness of the hole transport region 3 is not particularly limited, but is preferably 1 nm or more and 1000 nm or less, and more preferably 10 nm or more and 500 nm or less. In addition, for each layer constituting the hole transport region 3, the thickness of the hole injection layer 31 is not particularly limited, but is preferably 3 nm or more and 100 nm or less. The thickness of the hole transport layer 32 is not particularly limited, but is preferably 3 nm or more and 100 nm or less. The thickness of the electron blocking layer 33 is not particularly limited, but is preferably 1 nm or more and 100 nm or less. The thickness of the hole buffer layer (not shown) is not particularly limited as long as it exhibits the function of the hole buffer layer while not interfering with the function as an organic electroluminescence element. When the thickness of the hole transport region 3, the hole injection layer 31, the hole transport layer 32, or the electron blocking layer 33 satisfies the above range, a better hole transport characteristic can be obtained while suppressing the substantial increase in driving voltage.

[0116] The method for forming the hole transport region 3 and each of the layers that constitute it is not particularly limited, but examples thereof include known film formation methods such as vacuum deposition, spin coating, LB method, inkjet printing, laser printing, and laser thermal transfer.

[0117] (Emitting layer 4) The light-emitting layer 4 is disposed on the hole transport region 3. The details of the light-emitting layer 4 are as described above.

[0118] (Electron transport area 5) Electron transport region 5 is disposed over light emitting layer 4. Electron transport region 5 includes at least one of an electron injection layer 51, an electron transport layer 52, and a hole blocking layer 53, although embodiments are not limited in this respect.

[0119] The electron transport region 5 may be a single layer made of a single material, or may be a single layer made of a plurality of different materials. The electron transport region 5 may also have a multi-layer structure having a plurality of layers made of a plurality of different materials. For example, the electron transport region 5 may have a single layer structure of an electron injection layer 51 or an electron transport layer 52. For example, the electron transport region 5 may have a single layer structure made of an electron injection material and an electron transport material. For example, the electron transport region 5 may have a structure of an electron transport layer 52 / electron injection layer 51, which are stacked in order from the light-emitting layer 4. For example, the electron transport region 5 may have a structure of a hole blocking layer 53 / electron transport layer 52 / electron injection layer 51, which are stacked in order from the light-emitting layer 4. However, the structure of the electron transport region 5 is not limited to these.

[0120] The electron injection layer 51 and other layers constituting the electron transport region 5 are not particularly limited, and may contain, for example, a known electron injection material. Examples of the electron injection material include LiF, Liq ((8-quinolinolato)lithium), Li 2 Examples of the organic metal salt include lanthanum group metals such as O, BaO, NaCl, CsF, and Yb, and metal halides such as RbCl. The electron injection layer 51 is not particularly limited, but may include, for example, an electron transport material described below and an insulating organic metal salt. The organic metal salt is not particularly limited, but may be, for example, a material having an energy band gap of 4 eV or more. Examples of the organic metal salt include metal acetate, metal benzoate, metal acetoacetate, metal acetylacetonate, and metal stearate.

[0121] The electron transport layer 52 and other layers constituting the electron transport region 5 are not particularly limited, but may contain, for example, a known electron transport material. Examples of the electron transport material include anthracene-based compounds, Alq 3 (Tris(8-hydroxyquinolinolato)aluminum), 1,3,5-tri[(3-pyridyl)-phen-3-yl]benzene, 2,4,6-tris(3'-pyridin-3-yl)biphenyl-3-yl)-1,3,5-triazine, 2-(4-(N-phenylbenzoimidazolyl-1-ylphenyl)-9,10-dinaphthylanthracene, TPBi(1,3,5-tri(1-phenyl-1H-benzo[d]imidazol-2-yl)phenyl), BCP(2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline), Bp hen (4,7-diphenyl-1,10-phenanthroline), TAZ (3-(4-biphenyl)-4-phenyl-5-tert-butylphenyl-1,2,4-triazole), NTAZ (4-(naphthalen-1-yl)-3,5-diphenyl-4H-1,2,4-triazole), tBu-PBD (2-(4-biphenyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole), BAlq (bis(2-methyl-8-quinolinolato-N1,O8)-(1,1'-biphenyl-4-olato)aluminum), Bebq 2 (beryllium bis(benzoquinoline-10-olate), ADN (9,10-di(naphthalene-2-yl)anthracene), KLET-01, KLET-02, KLET-03, KLET-10, KLET-M1 (all manufactured by Chemipro Chemical Co., Ltd.), etc.

[0122] The hole blocking layer 53 is a layer that serves to prevent the injection of holes from the hole transport region 3 to the electron transport region 5. The material contained in the hole blocking layer 53 is not particularly limited, and any known material used for the hole blocking layer 53 can be used. The hole blocking layer 53 may contain, for example, a known hole blocking material. Examples of the hole blocking material include BCP (2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline) and Bphen (4,7-diphenyl-1,10-phenanthroline).

[0123] The thickness of the electron transport region 5 is not particularly limited, but is preferably 0.1 nm or more and 210 nm or less, and more preferably 100 nm or more and 150 nm or less. In addition, for each layer constituting the electron transport region 5, the thickness of the electron transport layer 52 is not particularly limited, but is preferably 10 nm or more and 100 nm or less, and more preferably 15 nm or more and 50 nm or less. The thickness of the hole blocking layer 53 is not particularly limited, but is preferably 10 nm or more and 100 nm or less, and more preferably 15 nm or more and 50 nm or less. The thickness of the electron injection layer 51 is not particularly limited, but is preferably, for example, 0.1 nm or more and 10 nm or less, and more preferably 0.3 nm or more and 9 nm or less. When the thickness of the electron injection layer 51 is in the above range, a better electron injection characteristic can be obtained while suppressing a substantial increase in the driving voltage. In addition, when the thickness of the electron transport region 5, the electron injection layer 51, the electron transport layer 52, or the hole blocking layer 53 is in the above range, a better electron transport characteristic can be obtained while suppressing a substantial increase in the driving voltage.

[0124] The method for forming the electron transport region 5 and each of the layers that constitute it is not particularly limited, but examples thereof include known film formation methods such as vacuum deposition, spin coating, LB method, inkjet printing, laser printing, and laser thermal transfer.

[0125] The second electrode 6 is disposed on the electron transport region 5. The second electrode 6 has electrical conductivity. In the organic electroluminescence element according to one embodiment of the present invention, the second electrode 6 is preferably a common electrode or a negative electrode. The second electrode 6 is preferably a transmissive electrode, a semi-transmissive electrode, or a reflective electrode.

[0126] The material constituting the second electrode 6 is not particularly limited, and examples thereof include metals, metal alloys, and conductive compounds. If the second electrode 6 is a transmissive electrode, the second electrode 6 preferably includes a transparent metal oxide, such as ITO, IZO, ZnO, and ITZO. If the second electrode 6 is a semi-transmissive electrode or a reflective electrode, the second electrode 6 preferably includes Ag, Mg, Cu, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, LiF / Ca, LiF / Al, Mo, Ti, or a compound or mixture containing these (for example, a mixture of Ag and Mg).

[0127] The second electrode 6 may be a single layer made of a single material, a single layer made of multiple different materials, or a multi-layer structure having multiple layers made of multiple different materials.

[0128] The thickness of the second electrode 6 is not particularly limited, but is preferably not less than 10 nm and not more than 1000 nm.

[0129] The second electrode 6 may be connected to an auxiliary electrode (not shown). By connecting the second electrode 6 to the auxiliary electrode, the resistance of the second electrode 6 can be further reduced.

[0130] In addition, a capping layer (not shown) may be further disposed on the second electrode 6. The capping layer (not shown) is not particularly limited, but may be, for example, α-NPD, NPB, TPD, m-MTDATA, Alq 3 , CuPc, TPD15 (N4,N4,N4',N4'-tetra(biphenyl-4-yl)biphenyl-4,4'-diamine), TCTA (4,4',4"-tri-9-carbazolyltriphenylamine), N,N'-bis(naphthalene-1-yl), or the like.

[0131] The materials constituting each of the above layers and electrodes may be used alone or in combination of two or more.

[0132] 1 to 3, the above-mentioned fused ring compound or the above-mentioned material for an organic electroluminescence device is preferably contained in the light-emitting layer 4, but may be contained in a layer other than the light-emitting layer 4. In addition, the above-mentioned fused ring compound or the above-mentioned material for an organic electroluminescence device may be contained in the light-emitting layer 4 and a layer other than the light-emitting layer 4.

[0133] 1 to 3, when a voltage is applied to the first electrode 2 and the second electrode 6, holes injected from the first electrode 2 move to the light-emitting layer 4 via the hole transport region 3, and electrons injected from the second electrode 6 move to the light-emitting layer 4 via the electron transport region 5. The electrons and holes recombine in the light-emitting layer 4 to generate excitons, and the excitons emit light as they fall from the excited state to the ground state. EXAMPLES

[0134] The present invention will be described in more detail with reference to the following examples and comparative examples, but the technical scope of the present invention is not limited to the following examples. Mass spectrometry and nuclear magnetic resonance (NMR) spectroscopy of the compounds were performed as follows.

[0135] (mass spectrometry) The compound was dissolved in tetrahydrofuran at a concentration of 0.1% by mass, and then mass spectrometry was performed using an LC-MS measurement device 1260 Infinity-quadrupole 6100MS (manufactured by Agilent Technologies, Inc.).

[0136] (Nuclear Magnetic Resonance (NMR) Spectroscopy) The compound was dissolved in deuterated THF (THF-d 8 ) and measured by proton NMR ( 1 H-NMR spectra were measured.

[0137] [Example 1] (Synthesis Example 1: Synthesis of intermediate (11))

[0138] [ka]

[0139] m-Dibromobenzene (10) (21 g, 89 mmol), aniline (17.4 g, 187 mmol), sodium tert-butoxide (21.4 g, 223 mmol), tris(dibenzylideneacetone)palladium(0) (815 mg, 0.89 mmol), and (±)BINAP (2,2'-bis(diphenylphosphino)-1,1'-binaphthyl, 1.66 g, 2.67 mmol) were placed in a 1 L three-neck flask, followed by the addition of toluene (300 mL) and heating under reflux for 3 hours under a nitrogen atmosphere. After cooling to room temperature, the reaction solution was passed through Florisil and a silica gel pad, and the solvent was then distilled off. The resulting residue was purified by column chromatography (eluent: hexane-ethyl acetate) to give intermediate (11) (yield 7.5 g, 32%).

[0140] (Synthesis Example 2: Synthesis of intermediate (13))

[0141] [ka]

[0142] In a 100 mL Schlenk flask, intermediate (11) (1.56 g, 6.0 mmol), dimethyl 2-iodo-1,3-benzenedicarboxylate (compound (12), 5.8 g, 18 mmol), cesium carbonate (5.5 g, 18 mmol), copper powder (114 mg, 1.8 mmol), and copper iodide (228 mg, 1.2 mmol) were placed, followed by the addition of dibutyl ether (24 mL) and heating under reflux for 5 days under a nitrogen atmosphere. After cooling to room temperature, water was added to the reaction solution. After separating the organic layer, the aqueous layer was extracted with ethyl acetate. The organic layer was washed with saturated saline and dried over anhydrous sodium sulfate. After removing the desiccant, the organic solvent was distilled off. The resulting residue was purified using silica gel column chromatography (eluent: dichloromethane-ethyl acetate) to obtain intermediate (13) (yield 1.65 g, 43%).

[0143] (Synthesis Example 3: Synthesis of intermediate (14))

[0144] [ka]

[0145] Intermediate (13) (1.62 g, 2.5 mmol) was placed in a 100 mL eggplant flask, followed by the addition of dioxane (20 mL), ethanol (20 mL), and water (10 mL). 10 M aqueous sodium hydroxide solution (10 g, 100 mmol) was added, and the mixture was heated under reflux for 2 hours under a nitrogen atmosphere. The mixture was allowed to cool to room temperature, and the organic solvent was distilled off. The residue was cooled to 0°C, and hydrochloric acid was added until the pH was 2 to 3 to make the solution acidic. The precipitated solid was filtered, washed repeatedly with water, and then vacuum dried to obtain intermediate (14) (yield 1.48 g, 100%).

[0146] (Synthesis Example 4: Synthesis of Compound (15) and Compound (16))

[0147] [ka]

[0148] In a 300 mL three-neck flask, intermediate (14) (1.38 g, 2.34 mmol) was placed, followed by the addition of dichloromethane (120 mL). Next, N,N'-dimethylformamide (3 drops) and oxalyl chloride (0.90 mL, 10.5 mmol) were added, followed by heating to reflux. After 2 hours, tin(IV) tetrachloride (1 M dichloromethane solution, 10.5 mL, 10.5 mmol) was added, followed by heating to reflux for another 5 hours. After cooling to 0°C, 1 M aqueous hydrochloric acid solution (100 mL) was added. The organic layer was separated, and the aqueous layer was extracted with dichloromethane. The organic layer was washed with a saturated aqueous ammonium chloride solution, and then dried over anhydrous sodium sulfate. The desiccant was filtered off, and the mixture was passed through a silica gel pad, followed by distilling off the organic solvent. The resulting residue was suspended in dichloromethane, and the solid was collected by filtration to obtain compound (15). The resulting residue was purified by silica gel column chromatography (eluent: dichloromethane-ethyl acetate) to give compound (16): Compound (15): Yield 0.35 g, yield 30%; 1 H-NMR: δ 7.54(brs, 2H),7.70-7.56(m, 3H),8.40-8.43(m, 4H),8.65-8.74(m, 6H),9.40-9.43(brs, 1H) (see Figure 4);LC-MS:517([M+H] + ) Compound (16): Yield 0.33 g, yield 26%; 1 H-NMR: δ 7.25-7.40(m, 2H),7.58-7.68(m, 2H),7.73(t, 1H, J=7.8Hz)7.82-7.89(m, 1H),8.30(d, 1H, LC-MS: 517 ([M+H] + ).

[0149] [Example 2] (Synthesis Example 5: Synthesis of intermediate (17))

[0150] [ka]

[0151] Intermediate (17) was obtained (yield 86%) in the same manner as in Synthesis Example 1 above, except that 4-tert-butylaniline was used instead of aniline.

[0152] (Synthesis Example 6: Synthesis of intermediate (19))

[0153] [ka]

[0154] Compound (19) was obtained (yield 73%) in the same manner as in Synthesis Example 2 above, except that intermediate (17) was used instead of intermediate (11) and compound (18) was used instead of compound (12).

[0155] (Synthesis Example 7: Synthesis of intermediate (20))

[0156] [ka]

[0157] Intermediate (20) was obtained (yield 100%) in the same manner as in Synthesis Example 3 above, except that intermediate (19) was used instead of intermediate (13).

[0158] (Synthesis Example 8: Synthesis of Compound (21) and Compound (22))

[0159] [ka]

[0160] Compounds (21) and (22) were obtained in the same manner as in Synthesis Example 4 above, except that intermediate (20) was used instead of intermediate (14). Compound (21): Yield 30%, LC-MS: 741 ([M+H] + ) Compound (22): Yield 36%, LC-MS: 741([M+H]+ ).

[0161] [Example 3] (Synthesis Example 9: Synthesis of intermediate (23))

[0162] [ka]

[0163] Intermediate (23) was obtained (yield 62%) in the same manner as in Synthesis Example 2 above, except that compound (18) was used instead of compound (12).

[0164] (Synthesis Example 10: Synthesis of compound (24))

[0165] [ka]

[0166] Intermediate (24) was obtained (yield 100%) in the same manner as in Synthesis Example 3 above, except that intermediate (23) was used instead of intermediate (13).

[0167] (Synthesis Example 11: Synthesis of Compound (25) and Compound (26))

[0168] [ka]

[0169] Compounds (25) and (26) were obtained in the same manner as in Synthesis Example 4, except that compound (24) was used instead of compound (14). Compound (25): Yield 20%, LC-MS: 629([M+H] + ) Compound (26): Yield 33%, LC-MS: 629([M+H] + ).

[0170] Comparative Example 1 [Preparation of comparative compound 1] Quinolino[3,2,1-de]acridine-5.9-dione represented by the following chemical formula was prepared as comparative compound 1.

[0171] [ka]

[0172] <Compound evaluation> [HOMO and LUMO measurements] Each of the compounds obtained above and each of the comparative compounds were prepared as a sample solid, and the HOMO and LUMO levels were measured according to the following procedure.

[0173] 1. Preparation of Measurement Sample (1) A sample solution was prepared so that the sample solid was 4 parts by mass per 100 parts by mass of methyl benzoate as a solvent.

[0174] (2) The sample solution prepared in (1) above was applied to an ITO substrate and a quartz substrate by spin coating under conditions that the dry thickness was 50 nm to form a coating film. -1 Heat at 120°C for 1 hour under a vacuum of 10 Pa or less, then -1 The thin film was cooled to room temperature under a vacuum of 100 Pa or less to form a thin film layer (thin film sample).

[0175] 2. Measurement of HOMO level The HOMO level of the thin film sample on the ITO substrate prepared in 1.(2) above was measured using an air photoelectron spectrometer AC-3 (manufactured by Riken Keiki Co., Ltd.).

[0176] 3. Measurement of LUMO level Using the thin film sample on the quartz substrate prepared in 1.(2) above, the energy gap value (Eg) was measured from the absorption edge of the ultraviolet-visible absorption spectrum using a spectrophotometer U-3900 (Hitachi High-Tech Corporation), and the LUMO level was calculated from the following formula. The calculation results are shown in Table 1 below.

[0177]

number

[0178] [Solution photoluminescence (PL) measurements] Each of the compounds obtained above and each of the comparative compounds were dissolved in toluene at a concentration of 1×10 -5 M solution was prepared. This solution was filled into a 1 cm square four-sided transmission cell, and PL measurements were performed at room temperature using a spectrofluorometer F7000 (Hitachi High-Tech Corporation). From the obtained emission spectrum, the peak wavelength, the full width at half maximum (FWHM) at which the emission intensity is reduced to half, and the Stokes shift were calculated. The evaluation results are shown in Table 1 below.

[0179] [S1 value, T1 value, and ΔE ST Value Measurement 1. Preparation of Measurement Sample (1) Each of the compounds obtained above or each of the comparative compounds (sample solids) above was dissolved in toluene and mixed with polymethyl methacrylate (PMMA) in a ratio of PMMA:sample solid = 99.5:0.5 (mass ratio) to prepare a 5 mass% toluene solution.

[0180] (2) The sample solution prepared in (1) above was spin-coated on an ITO substrate and a quartz substrate using a spin coater MS-B100 (Mikasa Co., Ltd.) under conditions that the dry thickness would be 500 nm. Then, the substrate was heated at 120°C for 1 hour to prepare a thin film sample.

[0181] 2. S1 value, T1 value, and ΔE ST Measurement of values Using the thin film sample on the quartz substrate prepared in 1.(2) above, the fluorescence spectrum and phosphorescence spectrum were measured at 77K using a spectrofluorometer F7000 (Hitachi High-Tech Corporation). The singlet energy S1 was calculated from the obtained fluorescence spectrum, and the triplet energy T1 was calculated from the obtained phosphorescence spectrum. In addition, ΔE STThe results are shown in Table 1 below.

[0182]

number

[0183] [PLQY measurement] On a quartz substrate, the compound shown in Table 1 below was applied in a weight ratio of 1% by weight to the host compound mCP. -5 The thin films were co-evaporated at a vacuum of 10 Pa to prepare thin films with a thickness of 50 nm. The PLQY of each emission spectrum of the prepared thin films was measured using a Quantaurus-QY absolute PL quantum yield (PLQY) measurement device C11347-01 manufactured by Hamamatsu Photonics K.K. During the measurement, the excitation wavelength was scanned from 300 nm to 400 nm at 10 nm intervals, and the excitation wavelength region in which the absorption value of the compound showed an excitation light intensity ratio of 10% or more was adopted. The PLQY value was taken as the highest value within the excitation wavelength region adopted.

[0184] The results are shown in Table 1 below.

[0185] [Table 1]

[0186] <Fabrication and evaluation of organic electroluminescence elements (organic EL elements)> Example 4 [Fabrication of organic EL elements] Polymer P-1 represented by the following chemical formula was synthesized according to the method for producing Compound T described in WO 2011 / 159872. The number average molecular weight (Mn) and weight average molecular weight (Mw) of P-1 measured by gel permeation chromatography (GPC) were 141,000 and 511,000, respectively.

[0187] [ka]

[0188] In addition, FA-14 (see the chemical formula below) described in US Patent Application Publication No. 2016 / 0315259 was synthesized by a standard method.

[0189] [ka]

[0190] A glass substrate with striped indium tin oxide (ITO) film of 150 nm thickness was prepared as the first electrode (anode). Poly(3,4-ethylene dioxythiophene) / poly(4-styrene sulfonate): PEDOT / PSS (Sigma-Aldrich) was applied to the glass substrate by spin coating to a dry thickness of 30 nm to form a hole injection layer.

[0191] Next, the above P-1 and FA-14 were dissolved in anisole, a solvent, to prepare a hole transport layer coating solution. P-1 was used in an amount that was 80% by mass relative to the total mass of the hole transport layer, and FA-14 was used in an amount that was 20% by mass relative to the total mass of the hole transport layer. Next, the obtained hole transport layer coating solution was applied onto the hole injection layer by spin coating under conditions that the dry film thickness was 125 nm, forming a coating film. The obtained coating film was left for 10 minutes. -1 Heat at 230°C for 1 hour under a vacuum of 10 Pa or less, then -1 The mixture was cooled to room temperature under a vacuum of 0.1 Pa or less to form a hole transport layer.

[0192] Next, on the hole transport layer, mCP as a host material and the above obtained Compound 15 were co-deposited in a mass ratio of mCP:Compound 15=98.5:1.5 in a vacuum deposition apparatus to form an emitting layer with a thickness of 55 nm.

[0193] Next, on the light-emitting layer, (8-quinolinolato)lithium (Liq):KLET-03 (manufactured by Chemipro Chemical Co., Ltd.) was co-deposited in a vacuum deposition apparatus so as to have a mass ratio of 2:8 to form an electron transport layer having a thickness of 20 nm.

[0194] Next, (8-quinolinolato)lithium (Liq) was deposited on the electron transport layer using a vacuum deposition apparatus to form an electron injection layer with a thickness of 3.5 nm.

[0195] Next, aluminum (Al) was deposited on the electron injection layer using a vacuum deposition apparatus to form a second electrode (cathode) with a thickness of 100 nm.

[0196] [Evaluation of organic EL elements] The emission peak wavelength, half-width and MaxEQE were evaluated according to the following method. A DC constant voltage power supply (KEITHLEY, 2400 source meter) was used to continuously change the voltage applied to the organic EL element to pass electricity through it and cause it to emit light, and the luminance and emission spectrum at this time were measured using a luminance measuring device (Hamamatsu Photonics, multi-channel spectrometer PMA12). The current value and external quantum efficiency EQE (%) were calculated from the measurement results. Furthermore, the wavelength showing the maximum value in the EQE graph against wavelength was defined as the emission peak wavelength (nm), and the wavelength width corresponding to half of that was defined as the half-width at half maximum or the half-width at half maximum FWHM (nm). Note that the MaxEQE shown here is the maximum EQE when the current density calculated from the area of ​​the organic EL element during current driving is 0.1 (mA / m 2 ) was used as the EQE value. However, the EQE (relative value) in Table 2 is expressed as a relative value when the value of Comparative Example 2 is set to 100.

[0197] (Examples 5 to 6 and Comparative Example 2) Organic EL devices were produced and evaluated in the same manner as in Example 1, except that in forming the light-emitting layer, compound 15 was changed to a compound shown in Table 2 below.

[0198] The evaluation results are shown in Table 2 below.

[0199] [Table 2]

[0200] From the results in Table 1, it was confirmed that the fused ring compound according to the present invention emits light with a narrow spectral width having a peak wavelength in the blue wavelength region, and exhibits blue light emission with high color purity. It was also confirmed that the fused ring compound according to the present invention has a narrow ΔEst, and is expected to emit light with high efficiency.

[0201] From the results in Table 2 above, it was confirmed that the organic EL element using the fused ring compound of the present invention emits light with a narrow spectral width and a peak wavelength in the blue wavelength region, and exhibits blue light emission with high color purity.

[0202] Furthermore, as shown in Table 2 above, it was confirmed that the EQE was 1.5 times or more higher and the luminous efficiency was significantly superior in the organic EL element using the compounds within the scope of the present invention shown in Examples 4 to 6 compared to the organic EL element using Comparative Compound 1, which is outside the scope of the present invention.

[0203] Although the present invention has been described above with reference to embodiments and examples, the present invention is not limited to the specific embodiments and examples, and various modifications and changes are possible within the scope of the invention described in the claims. [Explanation of symbols]

[0204] 1 board, 2 first electrode, 3 hole transport region, 4 light-emitting layer, 5 Electron transport area, 6 second electrode, 10 Organic electroluminescence element, 31 hole injection layer, 32 hole transport layer, 33 electron blocking layer, 51 electron injection layer, 52 electron transport layer, 53 Hole blocking layer.

Claims

1. A compound which is any one of the following compounds 5 to 10, 12 to 13, 15 to 23, and 25 to 27: 【Chemistry 1】 【Chemistry 2】 In the compounds 16 and 17, Ph represents an unsubstituted phenyl group.

2. An organic electroluminescence device having an organic layer comprising the compound according to claim 1.

3. The organic electroluminescence device according to claim 2 , wherein the organic layer is a light-emitting layer.

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