Fused ring compound, composition, material for organic electroluminescent device, electronic device, and organic electroluminescent device

Abstract

To provide a novel light-emitting material that can achieve high color purity, particularly, a novel blue light-emitting material that can achieve high color purity.SOLUTION: The present invention relates to a condensed ring compound of a specific structure in which there are a nitrogen atom (N) having electron-donating properties and a boron atom (B) having electron acceptability, and these and a conjugate system of a specific structure are bonded together so as to have proper arrangement.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a fused ring compound, a composition, a material for an organic electroluminescent device, an electronic device, and an organic electroluminescent device. [Background technology]

[0002] Organic electroluminescent devices are being actively developed as image display devices. Organic electroluminescent devices are so-called self-luminous display devices that realize display by causing holes and electrons injected from the first and second electrodes to recombine in the light-emitting layer, causing the light-emitting material, an organic compound contained in the light-emitting layer, to emit light.

[0003] As an organic electroluminescent device, for example, a device including a first electrode, a light-emitting layer disposed on the first electrode, and a second electrode disposed on the light-emitting layer is known. In this device, 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. Then, this device 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 electroluminescent devices. In particular, fused ring compounds containing heteroatoms have been investigated as blue-emitting materials (Patent Documents 1 to 4, and Non-Patent Documents 1 and 2).

[0005] In addition, in order to cover a wide color gamut, organic electroluminescent devices require luminescent 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. [Prior art documents] [Patent documents]

[0006] [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]

[0007] [Non-Patent Document 1] “Ultrapure Blue Thermally Activated Delayed Fluorescence Molecules: Efficient HOMO-LUMO Separation by the Multiple Resonance Effect” Takuji Hatakeyama, Kazushi Shiren, Kiichi Nakajima, Shintaro Nomura, Soichiro Nakatsuka, Keisuke Kinoshita, Jingping Ni, Yohei Ono, and Toshiaki Ikuta, Advanced Materials 2016, 28, 2777-2781 [Non-Patent Document 2] “Improving Processability and Efficiency of Resonant TADF Emitters: A Design Strategy” David Hall, Subeesh Madayanad Suresh, Paloma L. dos Santos, Eimantas Duda, Sergey Bagnich, Anton Pershin, Pachaiyappan Rajamalli, David B. Cordes, Alexandra MZ Slawin, David Beljonne, Anna K▲oe (lowercase o with umlaut)▼hler, Ifor DW Samuel, Yoann Olivier, and Eli Zysman-Colman, Advanced Optical Materials 2019,1901627 Summary of the Invention [Problem to be solved by the invention]

[0008] However, it is known that it is difficult to achieve emission of high color purity, especially in blue light-emitting materials. The heteroatom-containing fused ring compounds of Patent Documents 1 to 4 and Non-Patent Documents 1 and 2 also have problems in that they have a wide emission spectrum width and insufficient color purity.

[0009] Therefore, an object of the present invention is to provide a novel light-emitting material capable of realizing high color purity, in particular a novel blue light-emitting material capable of realizing high color purity. [Means for solving the problem]

[0010] The above-mentioned object of the present invention can be achieved by the following means.

[0011] A fused ring compound represented by the following general formula (1) or the following general formula (2):

[0012] [ka]

[0013] In the above general formula (1) and the above general formula (2), X 1 , X 2 and Y are each independently O, S, Se, Te, NR, or CR'R'', R, R' and R" are each independently a hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted aryloxy group, a substituted or unsubstituted heteroaryloxy group, a substituted or unsubstituted diarylamino group, a substituted or unsubstituted diheteroarylamino group, or a substituted or unsubstituted arylheteroarylamino group; Cy 1 , Cy 2 and Cy 3 are each independently a substituted or unsubstituted aromatic cyclic group, Cy 1 and Cy 2 At least one of the above is a structure represented by the following chemical formula (3) or a structure in which at least one hydrogen atom of the structure represented by the following chemical formula (3) has been substituted:

[0014] [ka]

[0015] Here, Cy 1 or Cy 2 is a structure represented by the above chemical formula (3) or a structure in which at least one hydrogen atom of the structure represented by the above chemical formula (3) is substituted, one unsubstituted bond constituting one benzene ring in the structure represented by the above chemical formula (3) or the structure in which at least one hydrogen atom of the structure represented by the above chemical formula (3) is substituted is 1 or Cy 2The bonds shown by the solid lines are formed. Effect of the Invention

[0016] According to the present invention, it is possible to provide a novel light-emitting material capable of realizing high color purity, in particular a novel blue light-emitting material capable of realizing high color purity. [Brief description of the drawings]

[0017] [Figure 1] 1 is a schematic cross-sectional view showing an organic electroluminescent device according to one embodiment of the present invention. [Diagram 2] FIG. 4 is a schematic cross-sectional view showing an organic electroluminescent device according to another embodiment of the present invention. [Diagram 3] FIG. 4 is a schematic cross-sectional view showing an organic electroluminescent device according to another embodiment of the present invention. [Figure 4] FIG. 1 is an explanatory diagram for qualitatively explaining the relationship between the energies. [Diagram 5] 1 is a graph showing the FWHM of emission in actually measured PL versus rearrangement energy (eV) calculated by density functional theory for known fused ring compounds R1 to R3. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] 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.

[0019] In the present specification, the phrase "X and Y are each independently" means that X and Y may be the same or different.

[0020] 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-constituting elements from the ring structure in an amount equal to the valence number, resulting in a free valence.

[0021] <Fused ring compounds> One aspect of the present invention relates to a fused ring compound represented by the following general formula (1) or the following general formula (2) (hereinafter, also simply referred to as "fused ring compound"):

[0022] [ka]

[0023] In the above general formula (1) and the above general formula (2), X 1 , X 2 and Y are each independently O, S, Se, Te, NR, or CR'R'', R, R' and R" are each independently a hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted aryloxy group, a substituted or unsubstituted heteroaryloxy group, a substituted or unsubstituted diarylamino group, a substituted or unsubstituted (unsubstituted) diheteroarylamino group, or a substituted or unsubstituted (unsubstituted) arylheteroarylamino group; Cy 1 , Cy 2 and Cy 3 are each independently a substituted or unsubstituted aromatic cyclic group, Cy 1 and Cy 2 At least one of the above is a structure represented by the following chemical formula (3) or a structure in which at least one hydrogen atom of the structure (the structure represented by the following chemical formula (3)) has been substituted,

[0024] [ka]

[0025] Here, Cy 1 or Cy 2is a structure represented by the above chemical formula (3) or a structure in which at least one hydrogen atom of the structure (a structure represented by the following chemical formula (3)) is substituted, one unsubstituted bond constituting one benzene ring in the structure (a structure represented by the above chemical formula (3) or a structure in which at least one hydrogen atom of the structure represented by the above chemical formula (3) is substituted) is 1 or Cy 2 The bonds shown by the solid lines are formed.

[0026] Thus, one aspect of the present invention relates to a fused ring compound represented by the above general formula (1) or (2).

[0027] The present inventors presume that the mechanism by which the above-mentioned configuration solves the problem is as follows.

[0028] “High-Performance Dibenzoheteraborin-Based Thermally Activated Delayed Fluorescence Emitters: Molecular Architectonics for Concurrently Achieving Narrowband Emission and Efficient Triplet-Singlet Spin Conversion” In Seob Park, Kyohei Matsuo, Naoya Aizawa, and Takuma Yasuda, Advanced Functional Materials 2018, 28, 1802031, it is reported that the spectral width of the fluorescence emission (full width at half maximum, FWHM) is approximately 10 times the width of the first excited singlet state (S 1 ) in the stable structure of the ground state (S 0 ) energy [E(S 0 @S 1 )] and the ground state (S 0 ) in the stable structure of the ground state (S 0 ) energy [E(S 0 @S0 Reorganization energy [E(S 0 @S 1 )-E(S 0 @S 0 ) has been shown to be closely related to

[0029] The fused ring compound according to one embodiment of the present invention has a nitrogen atom (N) having electron donating properties and a boron atom (B) having electron accepting properties, and has a structure in which these are bonded to a conjugated system of a specific structure in an appropriate arrangement. In this compound, the ground state (S 0 ) and the first excited state (S 1 ) is suppressed. As a result, emission of high color purity with a narrow spectral width, particularly high purity blue emission with a narrow spectral width, is realized.

[0030] The electronic effect of the above configuration is the first excited singlet state (S 1 This also contributes to increasing the oscillator strength f (hereinafter also simply referred to as "oscillator strength f") in a stable structure of the organic EL element, thereby making it possible to achieve not only high color purity but also sufficient luminous efficiency and sufficient element life.

[0031] 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.

[0032] In this specification, the term "aromatic cyclic group" refers to a cyclic structure that is aromatic in part or in its entirety. That is, the term "aromatic cyclic group" refers to a cyclic structure containing one or more aromatic rings selected from aromatic hydrocarbon rings or aromatic heterocycles. The aromatic cyclic group may be a cyclic structure composed of a single aromatic ring. The aromatic cyclic group may also be a cyclic structure composed of condensed rings of aromatic rings, or a cyclic structure composed of condensed rings of an aromatic ring and a non-aromatic ring.

[0033] Examples of the hydrocarbon ring constituting the aromatic cyclic group include a hydrocarbon ring containing one or more aromatic ring structures. The number of ring carbon atoms of the hydrocarbon ring constituting the aromatic cyclic group is not particularly limited, but is preferably 6 to 30. The number of ring carbon atoms of the hydrocarbon ring constituting the aromatic cyclic group is more preferably 6 to 20, and even more preferably 6 to 15. The number of ring carbon atoms of the hydrocarbon ring constituting the aromatic cyclic group is even more preferably 6 to 12, and especially preferably 6. The hydrocarbon ring constituting the aromatic cyclic group is not particularly limited, but examples thereof include a benzene ring, an indene ring, a naphthalene ring, an anthracene ring, a fluorene ring, a phenanthrene ring, a triphenylene ring, a pyrene ring, and a chrysene ring.

[0034] The heterocycle constituting the aromatic cyclic group includes a ring having one or more heteroatoms (e.g., nitrogen atom (N), oxygen atom (O), phosphorus atom (P), sulfur atom (S), silicon atom (Si)) as ring-forming atoms, and the remaining ring-forming atoms are carbon atoms (C), and includes one or more aromatic ring structures. The number of ring-forming carbon atoms of the heterocycle constituting the aromatic cyclic group is not particularly limited, but is preferably 2 to 30. The number of ring-forming carbon atoms of the heterocycle constituting the aromatic cyclic group is more preferably 2 to 20, and even more preferably 2 to 18. The number of ring-forming carbon atoms of the heterocycle constituting the aromatic cyclic group is particularly preferably 18.

[0035] The heterocycle constituting the aromatic cyclic group is not particularly limited, and examples thereof include a pyridine ring, a pyrazine ring, a pyridazine ring, a pyrimidine ring, a triazine ring, a quinoline ring, an isoquinoline ring, a quinoxaline ring, a quinazoline ring, a naphthyridine ring, an acridine ring, a phenazine ring, a benzoquinoline ring, a benzoisoquinoline ring, a phenanthridine ring, a phenanthroline ring, a benzoquinone ring, a coumarin ring, an anthraquinone ring, a fluorenone ring, a furan ring, a thiophene ring, a benzofuran ring, a benzothiophene ring, a dibenzofuran ring, a dibenzothiophene ring, a pyrrole ring, an indole ring, a carbazole ring, an indolocarbazole ring, Examples of such a ring include an imidazole ring, a benzimidazole ring, a pyrazole ring, an indazole ring, an oxazole ring, an isoxazole ring, a benzoxazole ring, a benzisoxazole ring, a thiazole ring, an isothiazole ring, a benzothiazole ring, a benzisothiazole ring, an imidazolinone ring, a benzimidazolinone ring, an imidazopyridine ring, an imidazopyrimidine ring, an imidazophenanthridine ring, a benzimidazophenanthridine ring, an azadibenzofuran ring, an azacarbazole ring, an azadibenzothiophene ring, a diazadibenzofuran ring, a diazacarbazole ring, a diazadibenzothiophene ring, a xanthone ring, and a thioxanthone ring.

[0036] The aromatic cyclic group preferably contains a benzene ring. Here, in the aromatic cyclic group, one unsubstituted bond constituting the benzene ring is a bond represented by Cy in the general formula (1) or (2). 1 and Cy 2 In addition, the two unsubstituted bonds constituting the benzene ring are preferably those represented by the solid lines in the general formula (1) or the general formula (2). 3 It is preferable to configure the bonds shown by solid lines.

[0037] From these findings, Cy 1 , Cy 2 and Cy 3It is preferable that all of the aromatic cyclic groups contain a benzene ring. In this case, one unsubstituted bond constituting the benzene ring is a bond represented by Cy in the general formula (1) and the general formula (2). 1 and Cy 2 The two unsubstituted bonds constituting the benzene ring are represented by the solid line bonds in the general formula (1) and the general formula (2). 3 It is particularly preferable that the aromatic cyclic group is a benzene ring or a ring represented by the above chemical formula (3) from the viewpoints of color purity, luminous efficiency (particularly, fluorescent luminous efficiency) and element life.

[0038] Examples of the fused ring compound include a fused ring compound represented by the general formula (1), a fused ring compound represented by the general formula (2), or a fused ring compound having a plurality of structures represented by the general formula (1) or the general formula (2).

[0039] When the fused ring compound is a fused ring compound having a plurality of structures represented by the general formula (1) or the general formula (2), the structure is not particularly limited as long as it is a structure having a plurality of structures represented by the general formula (1) or the general formula (2) in one compound. For example, a plurality of structures represented by the general formula (1) or the general formula (2) may be a structure in which the structures are bonded by a linking group such as a single bond, an alkylene group having 1 to 3 carbon atoms, a phenylene group, or a naphthylene group. In addition, for example, any ring (Cy) included in the general formula (1) or the general formula (2) may be bonded by a linking group such as a single bond, an alkylene group having 1 to 3 carbon atoms, a phenylene group, or a naphthylene group. 1 , Cy 2 or Cy 3 For example, any ring (Cy) included in the general formula (1) or the general formula (2) may be bonded to the structure represented by the general formula (1) or the general formula (2) so as to share the ring. 1 , Cy 2 or Cy 3 ) may be condensed with each other, and a plurality of structures represented by the general formula (1) or (2) may be bonded to each other.

[0040] Among these, any ring (Cy) contained in the general formula (1) or the general formula (2) is 1 , Cy 2 or Cy 3 It is preferable that the structure is a structure in which a plurality of structures represented by the general formula (1) or the general formula (2) are bonded together so as to share a common bond between the Cy 1 or Cy 2 It is more preferable that the structure is a structure in which a plurality of structures represented by the general formula (1) or the general formula (2) are bonded together so as to share the same. 1 and Cy 2 at least one of the structures is a structure represented by the chemical formula (3) or a structure in which at least one hydrogen atom of the structure represented by the chemical formula (3) is substituted, and it is further preferable that the structure is a structure in which a plurality of structures represented by the general formula (1) or the general formula (2) are bonded together so as to share these structures.

[0041] When the fused ring compound has a plurality of structures represented by the general formula (1) or the general formula (2), the number of structures represented by the general formula (1) or the general formula (2) in one compound is not particularly limited. However, the number of structures represented by the general formula (1) or the general formula (2) is preferably, for example, 2 or more and 6 or less, more preferably 2 or more and 3 or less, and even more preferably 2.

[0042] When the fused ring compound is a fused ring compound having a plurality of structures represented by the general formula (1) or the general formula (2), the fused ring compound is preferably a fused ring compound having a plurality of structures represented by the general formula (1) or a fused ring compound having a plurality of structures represented by the general formula (2). Also, a fused ring compound having a plurality of structures represented by the general formula (1) is more preferable.

[0043] From these facts, when the fused ring compound is a fused ring compound having a plurality of structures represented by the general formula (1) or the general formula (2), the fused ring compound is preferably a compound having a plurality of Cy structures represented by the general formula (1) or the general formula (2). 1 and Cy 2 at least one of the structures is a structure represented by the chemical formula (3) or a structure in which at least one hydrogen atom of the structure represented by the chemical formula (3) is substituted, and it is particularly preferable that the two structures represented by the general formula (1) or the general formula (2) are bonded together so as to share these structures.

[0044] Among the fused ring compounds represented by the general formula (1), the fused ring compounds represented by the general formula (2), and the fused ring compounds having a plurality of structures represented by the general formula (1) or the general formula (2), the compound represented by the general formula (1) is particularly preferred.

[0045] The fused ring compound according to one embodiment of the present invention is preferably a structure represented by any one of the following general formulae (1-1) to (1-15) and (2-1) to (2-10), or a structure in which at least one hydrogen atom of these structures has been substituted. Also, it is more preferably a structure represented by any one of the following general formulae (1-1) to (1-11), or a structure in which at least one hydrogen atom of these structures has been substituted. Furthermore, it is even more preferably a structure represented by the following general formula (1-1), a structure represented by the following general formula (1-2), a structure represented by the following general formula (1-3), a structure represented by the following general formula (1-8), or a structure in which at least one hydrogen atom of these structures has been substituted. And, it is more preferable that the structure is a structure of the following general formula (1-1), a structure of the following general formula (1-2), a structure of the following general formula (1-3), a structure of the following formula (1-8), a structure in which at least one hydrogen atom of the structure of the following general formula (1-2) is replaced, a structure in which at least one hydrogen atom of the structure of the following general formula (1-3) is replaced, or a structure in which at least one hydrogen atom of the structure of the following general formula (1-8) is replaced. Furthermore, it is particularly preferable that the structure is a structure in which at least one hydrogen atom of the structure of the following general formula (1-2), a structure in which at least one hydrogen atom of the structure of the following general formula (1-3), or a structure in which at least one hydrogen atom of the structure of the following general formula (1-8) is replaced.

[0046] [ka]

[0047] [ka]

[0048] [ka]

[0049] In the above general formulae (1-1) to (1-15) and (2-1) to (2-10), X 1 , X 2, and Y (i.e., X 1 , X 2 , Y, R, R′, and R″ are each independently the same as those described in the general formula (1) and the general formula (2).

[0050] In the general formula (1), the general formula (2), the general formulae (1-1) to (1-15), and the general formulae (2-1) to (2-10), X 1 , X 2 are preferably each independently O, S, Se, NR, or CR'R". 1 , X 2are each independently more preferably O, S, or NR, and even more preferably O or NR. In these cases, R is preferably a substituted or unsubstituted aryl group, or a substituted or unsubstituted heteroaryl group. Also, R is more preferably an aryl group substituted with an alkyl group (unsubstituted alkyl group), an aryl group substituted with a heteroaryl group (unsubstituted heteroaryl group), an aryl group substituted with a diarylamino group (unsubstituted diarylamino group), an unsubstituted aryl group, a heteroaryl group substituted with an alkyl group (unsubstituted alkyl group), or an unsubstituted heteroaryl group. Furthermore, R is more preferably a phenyl group substituted with an alkyl group, a phenyl group substituted with a heteroaryl group, a phenyl group substituted with a diarylamino group, a phenyl group, a biphenyl group, a terphenyl group (preferably an m-terphenyl group), a group derived from a ring represented by the above general formula (3) substituted with an alkyl group, a group derived from an unsubstituted ring represented by the above general formula (3), or a dibenzofuranyl group. And, R is more preferably a phenyl group substituted with a tert-butyl group (t-butyl group), a phenyl group substituted with a carbazolyl group, a phenyl group substituted with a diphenylamino group, a phenyl group, a biphenyl group, a terphenyl group (preferably an m-terphenyl group), a group derived from a ring represented by the above general formula (3) substituted with a tert-butyl group, a group derived from an unsubstituted ring represented by the above general formula (3), or a dibenzofuranyl group. Furthermore, R is particularly preferably a phenyl group substituted with a tert-butyl group, a phenyl group, a group derived from a ring represented by the above general formula (3) substituted with a tert-butyl group, or a group derived from an unsubstituted ring represented by the above general formula (3). Furthermore, R is extremely preferably a phenyl group, or a group derived from a ring represented by the above general formula (3) substituted with a tert-butyl group. Also, in these cases, R' and R" are each preferably independently a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group.Furthermore, it is more preferable that R' and R" are each independently an unsubstituted alkyl group, or a substituted or unsubstituted aryl group. It is further preferable that R' and R" are each independently a methyl group, a phenyl group, or a phenyl group substituted with a substituted or unsubstituted phenyl group. Here, examples of the phenyl group substituted with a substituted or unsubstituted phenyl group include a substituted or unsubstituted biphenyl group and a substituted or unsubstituted m-terphenyl group.

[0051] In the general formula (1), the general formula (2), the general formulae (1-1) to (1-15), and the general formulae (2-1) to (2-10), Y is preferably O, S, Se, NR, or CR'R". In this case, preferred embodiments of R include the above-mentioned X 1 and X 2 In this case, it is preferable that R' and R" are each independently a substituted or unsubstituted alkyl group. It is more preferable that R' and R" are each independently an unsubstituted alkyl group. It is further preferable that R' and R" are each independently a methyl group.

[0052] In the general formula (1), the general formula (2), the general formulae (1-1) to (1-15), and the general formulae (2-1) to (2-10), X 1 , X 2 It is particularly preferred that X and Y are each independently O, S, or NR. 1 , X 2 and Y are each highly preferably independently O or NR. In these cases, preferred embodiments of R are the same as those described above for X 1 and X 2 The preferred embodiments of R in NR are the same as those of R in the above-mentioned formula (1).

[0053] In the general formula (1), the general formula (2), the general formulae (1-1) to (1-15), and the general formulae (2-1) to (2-10), X 1 , X2 and Y are each independently X 1 , X 2 The partial structures in X and Y may be condensed or bonded to form a ring structure. 1 , X 2 and the partial structures in Y are preferably bonded to form a ring structure. The bond may be via a single bond or via a divalent linking group, but is preferably via a single bond.

[0054] In the fused ring compound according to one embodiment of the present invention, the halogen atom is not particularly limited, but examples thereof include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

[0055] In the fused ring compound according to one embodiment of the present invention, the alkyl group may be linear, branched, or cyclic. The number of carbon atoms in the alkyl group is not particularly limited, but is preferably, for example, 1 to 50. The number of carbon atoms in the alkyl group is more preferably 1 to 30, and even more preferably 1 to 20. The number of carbon atoms in the alkyl group is even more preferably 1 to 10, and particularly preferably 1 to 6. Specific examples of the alkyl group include, but are not particularly limited to, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an s-butyl group, and a tert-butyl group (t-butyl group. In this specification, tert- is also referred to as t-).), i-butyl, 2-ethylbutyl, 3,3-dimethylbutyl, n-pentyl, i-pentyl, neopentyl, tert-pentyl (t-pentyl), cyclopentyl, 1-methylpentyl, 3-methylpentyl, 2-ethylpentyl, 4-methyl-2-pentyl, n-hexyl, 1-methylhexyl, 2-ethylhexyl, 2-butylhexyl, cyclohexyl, 4-methylcyclohexyl group, 4-tert-butylcyclohexyl group (4-t-butylcyclohexyl group), n-heptyl group, 1-methylheptyl group, 2,2-dimethylheptyl group, 2-ethylheptyl group, 2-butylheptyl group, n-octyl group, tert-octyl group (t-octyl group), 2-ethyloctyl group, 2-butyloctyl group, 2-hexyloctyl group, 3,7-dimethyloctyl group, cyclooctyl group, n-nonyl group, n-decyl group, adamantyl group n-butyldecyl, 2-ethyldecyl, 2-butyldecyl, 2-hexyldecyl, 2-octyldecyl, n-undecyl, n-dodecyl, 2-ethyldodecyl, 2-butyldodecyl, 2-hexyldodecyl, 2-octyldecyl, n-tridecyl, n-tetradecyl, n-pentadecyl, n-hexadecyl, 2-ethylhexadecyl, 2-butylhexadecyl, 2-hexylhexadecyl, 2-octyl Examples of such alkyl groups include hexadecyl, n-heptadecyl, n-octadecyl, n-nonadecyl, n-icosyl, 2-ethylicosyl, 2-butylicosyl, 2-hexylicosyl, 2-octylicosyl, n-henicosyl, n-docosyl, n-tricosyl, n-tetracosyl, n-pentacosyl, n-hexacosyl, n-heptacosyl, n-octacosyl, n-nonadecyl, and n-triacontyl groups. In the fused ring compound according to one embodiment of the present invention, the aryl group is not particularly limited, but is preferably, for example, a monovalent group derived from a hydrocarbon ring containing one or more aromatic rings. The hydrocarbon ring constituting the aryl group may be a fused ring. And, when the aryl group contains two or more aromatic rings, the two or more aromatic rings may be bonded to each other via a single bond.

[0056] Thus, the aryl group may be a monocyclic aryl group or a polycyclic aryl group. The number of ring carbon atoms of the aryl group is not particularly limited, but is preferably 6 to 30. The number of ring carbon atoms of the aryl group is more preferably 6 to 20, and even more preferably 6 to 18. The number of ring carbon atoms of the aryl group is even more preferably 6 to 15. The number of ring carbon atoms of the aryl group is particularly preferably 6 to 12, and extremely preferably 6. Specific examples of the aryl group are not particularly limited, but include, for example, a phenyl group, a biphenyl group, a terphenyl group (preferably, an m-terphenyl group), a naphthyl group, a fluorenyl group, an anthracenyl group, a phenanthryl group, a biphenylyl group, a terphenylyl group, a quaterphenylyl group, a quinquephenylyl group, a sexiphenylyl group, a triphenylenyl group, a pyrenyl group, a benzofluoranthenyl group, a chrysenyl group, and groups formed by combinations thereof.

[0057] In the fused ring compound according to one embodiment of the present invention, the heteroaryl group is not particularly limited, but is preferably a monovalent group derived from a ring containing one or more aromatic heterocycles, the ring containing one or more heteroatoms (e.g., nitrogen atom (N), oxygen atom (O), phosphorus atom (P), sulfur atom (S), silicon atom (Si)) as ring-forming atoms, and the remaining ring-forming atoms are carbon atoms (C). When two or more heteroatoms are contained, the heteroatoms may be the same or different from each other. In addition, the ring constituting the heteroaryl group may be a fused ring. When the heteroaryl group contains two or more aromatic heterocycles, the two or more aromatic heterocycles may be bonded to each other via a single bond.

[0058] Thus, the heteroaryl group may be a monocyclic heteroaryl group or a polycyclic heteroaryl group. The number of ring carbon atoms of the heteroaryl group is not particularly limited, but is preferably 2 to 30. The number of ring carbon atoms of the heteroaryl group is more preferably 2 to 20, and even more preferably 2 to 10. Specific examples of the heteroaryl group include, but are not limited to, a thiophenyl group, a furanyl group, a pyronyl group, an imidazonyl group, a thiazolyl group, an oxazolyl group, an oxadiazonyl 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, an indolyl group, a carbazolyl group, an N-aryl group, Examples of the alkyl group include an alkylcarbazolyl group, an N-heteroarylcarbazolyl group, an N-alkylcarbazolyl 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 group derived from the ring represented by the above general formula (3), and a group consisting of a combination thereof.

[0059] In the fused ring compound according to one embodiment of the present invention, the alkoxy group may be linear, branched, or cyclic. The alkyl group constituting the alkoxy group is not particularly limited, but may be, for example, those described in the above description of the alkyl group. The number of carbon atoms in the alkoxy group is not particularly limited, but is preferably, for example, 1 to 20, and more preferably, 1 to 10. Specific examples of the alkoxy group are not particularly limited, but may be, for example, a methoxy group, an ethoxy group, an n-propoxy group, an isopropoxy group, a butoxy group, a pentyloxy group, a hexyloxy group, an octyloxy group, a nonyloxy group, and a decyloxy group.

[0060] In the fused ring compound according to one embodiment of the present invention, the aryl group constituting the aryloxy group is not particularly limited. For example, the aryl group described above may be mentioned. Specific examples of the aryloxy group include, but are not particularly limited to, a benzyloxy group, a 1-naphthyloxy group, a 2-naphthyloxy group, a 2-azulenyloxy group, and the like.

[0061] In the fused ring compound according to one embodiment of the present invention, the heteroaryl group constituting the heteroaryloxy group is not particularly limited. For example, the heteroaryl group described above can be mentioned. Specific examples of the heteroaryloxy group include, but are not particularly limited to, a 2-furanyloxy group, a 2-thienyloxy group, a 2-indolyloxy group, a 3-indolyloxy group, a 2-benzofuryloxy group, and a 2-benzothienyloxy group.

[0062] In the fused ring compound according to one embodiment of the present invention, the diarylamino group, the diheteroarylamino group, and the arylheteroarylamino group are not particularly limited. The aryl group and the heteroaryl group constituting the diarylamino group, the diheteroarylamino group, and the arylheteroarylamino group are, for example, those described in the above description of the aryl group and the above heteroaryl group. Specific examples of the diarylamino group are not particularly limited, but include a diphenylamino group, a phenyl(naphthyl)amino group, a di(biphenyl)amino group, and a di(p-terphenyl)amino group. Specific examples of the arylheteroarylamino group are not particularly limited, but include a phenyl(2-pyridyl)amino group. Specific examples of the diheteroarylamino group are not particularly limited, but include a di(2-pyridyl)amino group.

[0063] In the fused ring compound according to one embodiment of the present invention, when any of the sites is substituted, the type of the substituent is not particularly limited.The type of the substituent is preferably a deuterium atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted aryloxy group, a substituted or unsubstituted heteroaryloxy group, a substituted or unsubstituted diarylamino group, a substituted or unsubstituted (unsubstituted) diheteroarylamino group, or a substituted or unsubstituted (unsubstituted) arylheteroarylamino group. In the structures in which at least one hydrogen atom in the structures of the general formulae (1), (2), (1-1) to (1-15), (2-1) to (2-10), and (1-1) to (1-15) and (2-1) to (2-10) is substituted, when there are two or more substituted sites, the types of the substituents may be the same or different.

[0064] When the above-mentioned substituent is further substituted, the type of the substituent is not particularly limited.When the above-mentioned substituent is further substituted, the substituent is preferably a deuterium atom, a halogen atom, an unsubstituted alkyl group, an unsubstituted aryl group, an unsubstituted heteroaryl group, an unsubstituted alkoxy group, an unsubstituted aryloxy group, an unsubstituted heteroaryloxy group, an unsubstituted diarylamino group, an unsubstituted diheteroarylamino group, or an unsubstituted arylheteroarylamino group.When the above-mentioned substituent is further substituted, when there are two or more of the substituents, the types of the substituents may be the same or different from each other.

[0065] Substituents may form a ring structure by condensing or bonding partial structures in a single substituent or in two or more substituents.

[0066] The explanation of each of the above-mentioned substituents and the substituents when the above-mentioned substituents are further substituted is the same as that explained above.

[0067] Among these, the substituent is preferably a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, or a substituted or unsubstituted diarylamino group. Also, it is more preferable that the substituent is a substituted or unsubstituted alkyl group, a substituted or unsubstituted phenyl group, a substituted or unsubstituted carbazolyl group, or a substituted or unsubstituted diphenylamino group. And, it is more preferable that the substituent is an unsubstituted alkyl group, a phenyl group substituted with an alkyl group (unsubstituted alkyl group), a phenyl group, a carbazolyl group, or a diphenylamino group. Furthermore, it is even more preferable that the substituent is an unsubstituted branched alkyl group, a phenyl group, a phenyl group substituted with a linear alkyl group (unsubstituted linear alkyl group), a phenyl group substituted with a branched alkyl group (unsubstituted branched alkyl group), a carbazolyl group, or a diphenylamino group. Furthermore, the substituent is more particularly preferably a tert-butyl group, a phenyl group, a phenyl group substituted with a methyl group, a phenyl group substituted with a tert-butyl group, a carbazolyl group, or a diphenylamino group, and among these, the substituent is most preferably a tert-butyl group.

[0068] In one embodiment of the present invention, Cy 1 , Cy 2 and Cy 3It is preferable that at least one of the above is a substituted aromatic cyclic group. In this case, the substituent substituting the aromatic cyclic group is preferably an unsubstituted alkyl group, a phenyl group substituted with an alkyl group (unsubstituted alkyl group), a phenyl group, a carbazolyl group, or a diphenylamino group. In addition, it is more preferable that the substituent substituting the aromatic cyclic group is an unsubstituted alkyl group, a phenyl group substituted with an alkyl group, or a phenyl group. Here, the phenyl group substituted with an alkyl group is not particularly limited, but preferred examples include a phenyl group substituted with a methyl group, a phenyl group substituted with a tert-butyl group, and the like. The phenyl group substituted with an alkyl group is not particularly limited, but preferred specific examples include a dimethylphenyl group, a tert-butylphenyl group, a di-tert-butyl-phenyl group, and the like. Among these, the substituent substituting the aromatic cyclic group is more preferably an unsubstituted alkyl group, even more preferably an unsubstituted branched alkyl group, and particularly preferably a tert-butyl group.

[0069] In one embodiment of the present invention, Cy 1 and Cy 2 At least one of the above is preferably a structure in which at least one hydrogen atom of the structure represented by the above chemical formula (3) is substituted. In this case, it is preferable that the substituent substituting the structure represented by the above chemical formula (3) is an unsubstituted alkyl group, a phenyl group substituted with an alkyl group (unsubstituted alkyl group), or a phenyl group. Here, the phenyl group substituted with an alkyl group is not particularly limited, but a preferred example thereof is a phenyl group substituted with a tert-butyl group. The phenyl group substituted with an alkyl group is not particularly limited, but a preferred specific example thereof is a tert-butylphenyl group. Among these, the substituent substituting the structure represented by the above chemical formula (3) is more preferably an unsubstituted alkyl group, even more preferably an unsubstituted branched alkyl group, and particularly preferably a tert-butyl group.

[0070] Specific examples of fused ring compounds according to one embodiment of the present invention are shown below, namely, compounds 1 to 102, 201 to 203, 301 to 369, 401 to 413, and 501 to 532. However, the present invention is not limited to these specific examples.

[0071] [ka]

[0072] [ka]

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[0075] [ka]

[0076] [ka]

[0077] [ka]

[0078] [ka]

[0079] [ka]

[0080]

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[0095] [ka]

[0096] [ka]

[0097] Here, in the above compound, Ph represents a phenyl group (an unsubstituted phenyl group).

[0098] Among these, particularly preferred are Compound 2, Compound 14, Compound 97, Compound 100, Compound 101, Compounds 201 to 203, and Compound 301. Also, particularly preferred are Compound 100, Compound 202, and Compound 301. And, Compound 100 and Compound 202 are extremely preferred.

[0099] In the fused ring compound according to one embodiment of the present invention, the HOMO (Highest Occupied Molecular Orbital) energy is not particularly limited, but is preferably -5.8 eV or more. The HOMO energy is more preferably -5.6 eV or more, and even more preferably -5.4 eV or more. On the other hand, the HOMO energy is preferably -4.6 eV or less. The HOMO energy is more preferably -4.8 eV or less, and even more preferably -5.0 eV or less. Within the above range, the difference in HOMO energy with that of a general host material used in an organic electroluminescent device is small. This further suppresses the occurrence of undesirable effects such as an increase in driving voltage due to the formation of hole traps.

[0100] In the fused ring compound according to one embodiment of the present invention, the LUMO (Lowest Unoccupied Molecular Orbital) energy is not particularly limited, but is preferably -2.4 eV or more. The LUMO energy is more preferably -2.2 eV or more, and even more preferably -2.1 eV or more. The LUMO energy is particularly preferably -2.0 eV or more. On the other hand, the LUMO energy is preferably -0.8 eV or less. The LUMO energy is more preferably -1.0 eV or less, and even more preferably -1.1 eV or less. The LUMO energy is particularly preferably -1.2 eV or less. Within the above range, the difference with the LUMO energy of a general host material used in an organic electroluminescent device is small. This further suppresses the occurrence of undesirable effects such as an increase in driving voltage due to the formation of electron traps.

[0101] In the fused ring compound according to one embodiment of the present invention, the adiabatic first excited singlet state (S 1 ) energy (hereinafter referred to as "insulation S 1The peak of the fluorescent wavelength obtained by converting the excitation energy (eV) to the light wavelength (nm) is not particularly limited. Here, the peak of the fluorescent wavelength is preferably 360 nm or more and 515 nm or less. The peak of the fluorescent wavelength is more preferably 380 nm or more and 505 nm or less, and even more preferably 400 nm or more and 500 nm or less. Furthermore, the peak of the fluorescent wavelength is even more preferably 420 nm or more and 490 nm or less. The peak of the fluorescent wavelength is particularly preferably 440 nm or more and 480 nm or less, and even more particularly preferably 440 nm or more and 465 nm or less. Furthermore, the peak of the fluorescent wavelength is extremely preferably 455 nm or more and 465 nm or less. Within the above range, good light emission, particularly good blue light emission, can be obtained.

[0102] In addition, the preferred range of the peak wavelength of fluorescent emission in photoluminescence (PL) is also 1 This is the same as the preferred range of the peak of the fluorescent wavelength obtained by converting the excitation energy into a light wavelength.

[0103] The spectral width of the fluorescent emission in photoluminescence (PL) (full width at half maximum of the peak of the fluorescent emission spectrum, FWHM) is not particularly limited, but the narrower the better. Specifically, the spectral width of the fluorescent emission in PL is preferably 30 nm or less, more preferably 25 nm or less, and even more preferably 20 nm or less (lower limit value: more than 0 nm). Within the above range, light emission with higher color purity can be obtained.

[0104] In the fused ring compound according to one embodiment of the present invention, the first excited singlet state (S 1) is not particularly limited, but is preferably 0.1 or more. The oscillator strength f is more preferably 0.2 or more, and even more preferably 0.3 or more. The oscillator strength f is particularly preferably 0.4 or more. It is considered that a higher fluorescence emission intensity can be obtained within the above range. The theoretical upper limit of the oscillator strength f is the number of electrons contained in the molecule. The upper limit of the oscillator strength f may be, for example, 2 or 3, but is not particularly limited to these.

[0105] In the fused ring compound according to one embodiment of the present invention, the rearrangement energy is preferably 0.1 eV or less. The rearrangement energy is more preferably 0.08 eV or less, and even more preferably 0.07 eV or less. The rearrangement energy is particularly preferably less than 0.065 eV, and extremely preferably 0.06 eV or less (lower limit 0 eV). It is believed that within the above range, emission with a narrower emission spectrum width and high color purity can be obtained.

[0106] The above HOMO, LUMO, and adiabatic S 1 The peak of the fluorescence wavelength obtained by converting the excitation energy into the light wavelength, the oscillator strength f, and the rearrangement energy can be calculated by the density functional theory (DFT) using Gaussian 16 (Gaussian Inc.) as calculation software. Details of each calculation method are described in the Examples.

[0107] The peak wavelength and spectral width of PL fluorescence can be measured using a spectrofluorometer F7000 manufactured by Hitachi High-Tech Science Corporation (formerly Hitachi High-Technologies Corporation). Details of the measurement method will be described in the Examples.

[0108] The synthesis method of the fused ring compound according to one embodiment of the present invention is not particularly limited, and the compound can be synthesized based on the knowledge of known synthesis methods.

[0109] For example, the above compound 2 and the above compound 301 can be synthesized by the method described in the Examples. Other fused ring compounds represented by the above general formula (1-2) and fused ring compounds represented by a structure in which at least one hydrogen atom of the structure of the above general formula (1-2) is substituted can also be synthesized in accordance with this method. For example, in this method, they can be synthesized by changing the raw materials and reaction conditions, adding or removing some steps, or appropriately combining the above synthesis method with a known synthesis method.

[0110] Also, for example, the above compound 14 can be synthesized by the method described in the Examples. Other fused ring compounds represented by the above general formula (1-1) and fused ring compounds represented by a structure in which at least one hydrogen atom of the structure of the above general formula (1-1) is substituted can also be synthesized in accordance with this method. For example, in this method, they can be synthesized by changing the raw materials and reaction conditions, adding or removing some steps, or appropriately combining the above synthesis method with a known synthesis method.

[0111] For example, the above-mentioned compound 97, compound 100 and compound 101 can be synthesized by the method described in the Examples. Other fused ring compounds represented by the above-mentioned general formula (1-3) and fused ring compounds represented by a structure in which at least one hydrogen atom of the structure of the above-mentioned general formula (1-3) is substituted can also be synthesized in accordance with these methods. For example, in these methods, they can be synthesized by changing raw materials, reaction conditions, etc., adding or removing some steps, or combining the above-mentioned synthesis method with a known synthesis method.

[0112] Furthermore, for example, the above compounds 201 to 203 can be synthesized by the methods described in the Examples. Other fused ring compounds represented by the above general formula (1-8) and fused ring compounds represented by a structure in which at least one hydrogen atom of the structure of the above general formula (1-8) is substituted can also be synthesized in accordance with these methods. For example, in these methods, they can be synthesized by changing raw materials, reaction conditions, etc., adding or removing some steps, or combining the above synthesis method with a known synthesis method.

[0113] Furthermore, other fused ring compounds represented by the general formula (1), fused ring compounds represented by the general formula (2), and fused ring compounds having a plurality of structures represented by the general formula (1) or the general formula (2) also have a common skeletal structure with these compounds, or a similar skeletal structure. For this reason, other fused ring compounds represented by the general formula (1), fused ring compounds represented by the general formula (2), and fused ring compounds having a plurality of structures represented by the general formula (1) or the general formula (2) can also be synthesized according to these methods. For example, in these methods, the raw materials and reaction conditions can be appropriately changed, some steps can be added or removed, or the above synthesis method can be appropriately combined with a known synthesis method, etc.

[0114] 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 fused ring compound according to one embodiment of the present invention can be confirmed, for example, by a known method (e.g., NMR, LC-MS, etc.).

[0115] <Composition> Another aspect of the present invention relates to a composition comprising the above-mentioned fused ring compound. The composition according to one embodiment of the present invention preferably comprises the above-mentioned fused ring compound and other materials used in electroluminescent devices. Furthermore, the composition according to one embodiment of the present invention more preferably comprises the above-mentioned fused ring compound and other materials used in organic electroluminescent devices.

[0116] Other materials used in the electroluminescent element and the organic electroluminescent element are not particularly limited, and may include known materials. For example, the other materials used in the organic electroluminescent element may be those mentioned as materials constituting each layer in the description of the organic electroluminescent element described later. Among these, it is preferable to use a dopant material or a host material mentioned in the description of the light-emitting layer of the organic electroluminescent element described later. It is more preferable to use a phosphorescent material (phosphorescent compound), a thermally activated delayed fluorescent material (TADF material, TADF compound), or a host material mentioned in the description of the light-emitting layer of the organic electroluminescent element described later. It is more preferable to use a host material, or a phosphorescent compound or a TADF compound, and a host material. It is particularly preferable to use a phosphorescent compound or a compound having TADF properties, and a host material. It is also extremely preferable to use a phosphorescent compound and a host material. Here, the phosphorescent compound is preferably a phosphorescent complex mentioned in the description of the light-emitting layer of the organic electroluminescent element described later. It is more preferable to use a platinum complex mentioned in the description of the light-emitting layer of the organic electroluminescent element described later.

[0117] Thus, a preferred embodiment of the present invention is a composition that further contains a TADF compound or a phosphorescent compound, which will be described later, in addition to the above-mentioned fused ring compound. In this case, the phosphorescent compound is preferably a phosphorescent complex, and more preferably a platinum complex, which will be described later. When the material for an organic electroluminescent device, particularly the light-emitting layer material, contains a TADF compound or a phosphorescent compound in addition to the above-mentioned fused ring compound, the light-emitting efficiency and element life of the organic electroluminescent device can be significantly improved. The reason for this is as described in the description of the light-emitting layer of the organic electroluminescent device, which will be described later.

[0118] In one embodiment of the present invention, the composition may be a liquid composition further comprising a solvent. The solvent is not particularly limited, but is preferably a solvent having a boiling point of 100°C or more and 350°C or less at atmospheric pressure (101.3 kPa, 1 atm). The boiling point of the solvent at atmospheric pressure is more preferably 150°C or more and 320°C or less, and even more preferably 180°C or more and 300°C or less. When the boiling point of the solvent at atmospheric pressure is within the above range, the film-forming property and processability in the wet film-forming method, particularly the inkjet method, are improved.

[0119] The solvent having a boiling point of 100° C. or more and 350° C. or less at atmospheric pressure is not particularly limited, and any known solvent can be appropriately used. Specific examples of solvents having a boiling point of 100° C. or more and 350° C. or less at atmospheric pressure are given below, but the present invention is not limited to these specific examples.

[0120] Examples of the hydrocarbon solvent include octane, nonane, decane, undecane, and dodecane. Examples of the aromatic hydrocarbon solvent include toluene, xylene, ethylbenzene, n-propylbenzene, iso-propylbenzene, mesitylene, n-butylbenzene, sec-butylbenzene, 1-phenylpentane, 2-phenylpentane, 3-phenylpentane, phenylcyclopentane, phenylcyclohexane, 2-ethylbiphenyl, and 3-ethylbiphenyl. Examples of the ether solvent include Examples of the solvent include 1,4-dioxane, 1,2-diethoxyethane, diethylene glycol dimethylether, diethylene glycol diethylether, anisole, ethoxybenzene, 3-methylanisole, m-dimethoxybenzene, etc. Examples of the ketone solvent include 2-hexanone, 3-hexanone, cyclohexanone, 2-heptanone, 3-heptanone, 4-heptanone, cycloheptanone, etc.Examples of the ester-based solvent include butyl acetate, butyl propionate, butyl butyrate, propylene carbonate, methyl benzoate, ethyl benzoate, 1-propyl benzoate, and 1-butyl benzoate. Examples of the nitrile-based solvent include benzonitrile and 3-methylbenzonitrile. Examples of the amide-based solvent include dimethylformamide, dimethylacetamide, and N-methylpyrrolidone. These solvents may be used alone or in combination of two or more.

[0121] The composition according to one embodiment of the present invention is preferably used as a material for an organic electroluminescent element. That is, another embodiment of the present invention relates to a material for an organic electroluminescent element, comprising the above-mentioned composition. In addition, the material for an organic electroluminescent element is preferably a material for an emission layer.

[0122] As a preferred embodiment of the present invention, the material for organic electroluminescent elements may be, for example, the above-mentioned composition that is not a liquid composition (substantially does not contain a solvent). Even when the material for organic electroluminescent elements is not a liquid composition, the material for organic electroluminescent elements is preferably a material for an emitting layer.

[0123] Here, "substantially free of solvent" means that the content of the solvent in the composition is less than 1% by mass relative to the total mass of the composition. When the material for organic electroluminescent devices is not a liquid composition, it is preferable that the composition substantially does not contain a solvent, and it is preferable that the composition does not contain any solvent at all (0% by mass relative to the total mass of the composition).

[0124] The preferred content of the above-mentioned fused ring compound relative to the total mass of the material for organic electroluminescent elements (particularly, the material for the light-emitting layer) (total mass excluding the solvent in the case of a liquid composition) is the same as the preferred content of the above-mentioned fused ring compound relative to the total mass of the light-emitting layer in the light-emitting layer of an organic electroluminescent element described below.

[0125] Furthermore, the preferred content of the phosphorescent compound or TADF compound (preferably, the phosphorescent compound) relative to the total mass of the material for organic electroluminescent element (particularly, the material for the light-emitting layer) (total mass excluding the solvent in the case of a liquid composition) is the same as the preferred content of the phosphorescent compound or TADF compound (preferably, the phosphorescent compound) relative to the total mass of the light-emitting layer in the light-emitting layer of the organic electroluminescent element described below.

[0126] The preferred content (parts by mass) of the phosphorescent compound or TADF compound (preferably, the phosphorescent compound) relative to 100 parts by mass of the above-mentioned fused ring compound in the material for organic electroluminescent elements (particularly, the material for the light-emitting layer) is also similar to the preferred content (parts by mass) of the phosphorescent compound or TADF compound (preferably, the phosphorescent compound) relative to 100 parts by mass of the above-mentioned fused ring compound in the light-emitting layer of the organic electroluminescent element described later.

[0127] The preferred content of the host material relative to the total mass of the material for the organic electroluminescent element (particularly, the material for the light-emitting layer) (total mass excluding the solvent in the case of a liquid composition) is the same as the preferred content of the host material relative to the total mass of the light-emitting layer in the light-emitting layer of the organic electroluminescent element described below.

[0128] The preferred content (parts by mass) of the host material per 100 parts by mass of the above-mentioned fused ring compound in the material for organic electroluminescent elements (particularly, the material for the light-emitting layer) is also similar to the preferred content (parts by mass) of the host material per 100 parts by mass of the above-mentioned fused ring compound in the light-emitting layer of the organic electroluminescent element described later.

[0129] When the amounts of the above-mentioned fused ring compound, phosphorescent compound or TADF compound, and host material added in the material for organic electroluminescent element (particularly, the material for the light-emitting layer) are within the above-mentioned ranges, an organic electroluminescent element having superior color purity of emitted light, higher luminous efficiency, and longer life can be obtained.

[0130] <Electronic elements> Another aspect of the present invention relates to an electronic device comprising the above-mentioned fused ring compound, the above-mentioned composition, or the above-mentioned material for an organic electroluminescent device.

[0131] An electronic device according to a preferred embodiment of the present invention includes, for example, the above-mentioned fused ring compound or the above-mentioned composition, where the composition is not a liquid composition (does not substantially contain a solvent).

[0132] An electronic device according to an embodiment of the present invention includes, but is not limited to, a first electrode, a second electrode, and a single or multiple layers (e.g., an organic layer, etc.). The second electrode is disposed on the first electrode.

[0133] 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" the other part, this includes not only when it is "directly below" the other part, but also when there is another part in between. In this application, being "located on" includes not only when it is on the top, but also when it is located on the bottom or lower surface.

[0134] In one embodiment of the present invention, the electronic element is preferably an organic electroluminescent element (organic electroluminescence element, organic EL element). That is, another aspect of the present invention relates to an organic electroluminescent element comprising a first electrode, a second electrode, and a single or multiple organic layers disposed between the first electrode and the second electrode, at least one of the organic layers comprising the above-mentioned fused ring compound, the above-mentioned composition, or the above-mentioned material for organic electroluminescent elements. The organic layer comprising the above-mentioned fused ring compound, the above-mentioned composition, or the above-mentioned material for organic electroluminescent elements preferably comprises a light-emitting layer. These organic electroluminescent elements can realize light emission with high color purity, particularly blue light emission with high color purity.

[0135] Thus, the light-emitting layer preferably contains at least one of the above-mentioned fused ring compounds.

[0136] The content of the fused ring compound relative to the total mass of the light-emitting layer is not particularly limited, but is preferably 0.05% by mass or more. The content is more preferably 0.1% by mass or more, and even more preferably 0.2% by mass or more. The content of the fused ring compound relative to the total mass of the light-emitting layer is preferably 50% by mass or less. The content is more preferably 30% by mass or less, and even more preferably 25% by mass or less. Within these ranges, an organic electroluminescent device with superior color purity of light emission, higher luminous efficiency, and longer life can be obtained.

[0137] 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.

[0138] The light-emitting layer is not particularly limited, and may contain, for example, a known light-emitting layer material. Thus, even when the light-emitting layer contains the above-mentioned fused ring compound, the light-emitting layer may further contain other compounds. For example, the light-emitting layer may contain, in addition to the above-mentioned fused ring compound, an anthracene derivative, a pyrene derivative, a fluoranthene derivative, a chrysene derivative, a dihydrobenzoanthracene derivative, or a triphenylene derivative.

[0139] In addition to the above-mentioned fused ring compound, the light-emitting layer preferably contains a known thermally activated delayed fluorescence (TADF) material (TADF compound). TADF is a compound that is characterized by the energy difference (ΔE ST ) is a phenomenon in which reverse intersystem crossing from triplet excitons to singlet excitons occurs in small compounds. TADF compounds are compounds in which this phenomenon occurs.

[0140] Examples of thermally activated delayed fluorescent materials (TADF materials, TADF compounds) include the following compounds.

[0141] [ka]

[0142] [ka]

[0143] [ka]

[0144] In addition, the light-emitting layer preferably contains a phosphorescent material (phosphorescent compound) in addition to the above-mentioned fused ring compound. The phosphorescent compound is not particularly limited and any known phosphorescent material can be used. Among these, phosphorescent complexes are preferred, and platinum complexes are more preferred.

[0145] Examples of phosphorescent materials (phosphorescent compounds) include the following compounds.

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[0150] [ka]

[0151] By including a TADF material (TADF compound) or a phosphorescent material (phosphorescent compound) in the light-emitting layer in addition to the above-mentioned fused ring compound, the light-emitting efficiency and device life of the organic electroluminescent device can be significantly improved. The reason for this is presumed to be as follows.

[0152] As is well known, in the light-emitting layer of an organic electroluminescent device, singlet excitons and triplet excitons are generated by the recombination of holes and electrons at a ratio of 1:3. In an element containing only a fluorescent material as a light-emitting material, only singlet excitons are involved in light emission, whereas in an element containing a TADF compound or a phosphorescent compound as a light-emitting material, both singlet excitons and triplet excitons can be used for light emission. Therefore, in an element containing these, the light-emitting efficiency is significantly improved. On the other hand, excitons generated on a TADF compound or a phosphorescent compound generally have a long life of 1 μs or more. Excitons are in an unstable state with high energy. Therefore, while excitons exist, they may cause material degradation leading to a decrease in the life of the element. When a TADF compound or a phosphorescent compound exists in addition to the above-mentioned fused ring compound in the light-emitting layer, excitons are generated on the TADF compound or the phosphorescent compound with high efficiency. Furthermore, energy is transferred from the exciton to the fused ring compound through the FRET (F▲oe (lowercase o with umlaut)▼raster Resonance Energy Transfer) mechanism. As a result, highly efficient fluorescence emission from the fused ring compound is obtained, and the time that the excitons remain on the TADF compound or phosphorescent compound is shortened. This significantly reduces the possibility of material degradation and significantly improves the device life.

[0153] The content of the TADF compound or phosphorescent compound (preferably, phosphorescent compound) relative to the total mass of the light-emitting layer is not particularly limited, but is preferably 0.1 mass% or more. The content is more preferably 0.5 mass% or more, and even more preferably 1 mass% or more. The content is even more preferably 3 mass% or more, and particularly preferably 5 mass% or more. The content of the TADF compound or phosphorescent compound (preferably, phosphorescent compound) relative to the total mass of the light-emitting layer is preferably 50 mass% or less. The content is more preferably 40 mass% or less, and even more preferably 30 mass% or less. When the light-emitting layer contains both the TADF compound and the phosphorescent compound, it is preferable that the total content of them is within the above range. Within these ranges, an organic electroluminescent device with better color purity of light emission, higher luminous efficiency, and longer life can be obtained.

[0154] When the light-emitting layer contains a TADF compound or a phosphorescent compound (preferably a phosphorescent compound), the content is not particularly limited, but is preferably 100 parts by mass or more relative to 100 parts by mass of the above-mentioned fused ring compound. Moreover, the content is more preferably 150 parts by mass or more, and even more preferably 200 parts by mass or more, relative to 100 parts by mass of the above-mentioned fused ring compound. Moreover, the content is preferably 10,000 parts by mass or less relative to 100 parts by mass of the above-mentioned fused ring compound. Moreover, the content is more preferably 7,500 parts by mass or less, and even more preferably 5,000 parts by mass or less, relative to 100 parts by mass of the above-mentioned fused ring compound. Note that, when the light-emitting layer contains both a TADF compound and a phosphorescent compound, the total content of these is preferably within the above-mentioned range. Within these ranges, an organic electroluminescent device with better color purity of light emission, higher luminous efficiency, and longer life can be obtained.

[0155] The light-emitting layer is not particularly limited, and may contain, for example, a known host material. For example, it may contain 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 light-emitting layer is not limited thereto, and may contain, for example, Alq 3 (tris(8-hydroxyquinolino)aluminum), CBP (4,4'-bis(N-carbazolyl)-1,1'-biphenyl), 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), 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), or PPF (2,8-bis(diphenylphosphoryl)dibenzofuran), etc.

[0156] The light-emitting layer preferably contains a host material having a HOMO of -5.2 eV or less. The light-emitting layer preferably contains a host material having a LUMO of -1.4 eV or less. The use of a host material having low HOMO and LUMO and high electron transport properties provides an advantage in that the driving durability of an organic electroluminescent device, particularly a blue organic electroluminescent device, is improved. Such a material is not particularly limited, but preferred examples include the following compounds disclosed in “An Alternative Host Material for Long-Lifespan Blue Organic Light-Emitting Diodes Using Thermally Activated Delayed Fluorescence” Soo-Ghang Ihn, Namheon Lee, Soon Ok Jeon, Myungsun Sim, Hosuk Kang, Yongsik Jung, Dal Ho Huh, Young Mok Son, Sae Youn Lee, Masaki Numata, Hiroshi Miyazaki, Rafael Go'(lowercase o with acute accent)▼mez-Bombarelli, Jorge Aguilera-Iparraguirre, Timothy Hirzel, Al'(lowercase a with acute accent)▼n Aspuru-Guzik, Sunghan Kim, and Sangyoon Lee, Advanced Science News 2017, 4, 1600502. When a light-emitting layer is formed in combination with such a host material, conventional blue light-emitting materials may become deep hole traps and cause undesirable effects such as an increase in driving voltage, etc. On the other hand, the above-mentioned fused ring compounds have weak hole trapping properties and are expected to act to suppress the occurrence of an increase in driving voltage, etc.

[0157] [ka]

[0158] The light-emitting layer may contain, as a host material, the following compound H-H1 or the following compound H-E1.

[0159] [ka]

[0160] Among these, the light-emitting layer preferably contains, as a host material, the above compound H-H1 or the above compound H-E1, and more preferably contains the above compound H-H1 and the above compound H-E1.

[0161] The content of the host material relative to the total mass of the light-emitting layer is not particularly limited, but is preferably 5% by mass or more. The content is more preferably 10% by mass or more, and even more preferably 20% by mass or more. The content of the host material relative to the total mass of the light-emitting layer is preferably 99% by mass or less. The content is more preferably 95% by mass or less, and even more preferably 90% by mass or less. Within these ranges, an organic electroluminescent device with superior color purity of light emission, higher luminous efficiency, and longer life can be obtained.

[0162] When the light-emitting layer contains a host material, the content is not particularly limited, but is preferably 1000 parts by mass or more relative to 100 parts by mass of the above-mentioned fused ring compound. The content is more preferably 2000 parts by mass or more, and even more preferably 3000 parts by mass or more, relative to 100 parts by mass of the above-mentioned fused ring compound. The content of the host material is preferably 200000 parts by mass or less relative to 100 parts by mass of the above-mentioned fused ring compound. The content is more preferably 150000 parts by mass or less, and even more preferably 100000 parts by mass or less, relative to 100 parts by mass of the above-mentioned fused ring compound. Within these ranges, an organic electroluminescent device with better color purity of light emission, higher luminous efficiency, and longer life can be obtained.

[0163] The light-emitting layer is not particularly limited, and may contain, for example, a known dopant material, such as a styryl derivative (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 or a derivative thereof (e.g., 2,5,8,11-tetra-tert-butylperylene (TBP)), or pyrene or a derivative thereof (e.g., 1,1-dipyrene, 1,4-dipyrenylbenzene, 1,4-bis(N,N-diphenylamino)pyrene), etc.

[0164] 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.

[0165] 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 30 nm.

[0166] The emission wavelength of the light-emitting layer (i.e., the emission wavelength of the organic electroluminescent device having the light-emitting layer) is not particularly limited. However, it is preferable that the light-emitting layer emits light having a peak in a wavelength region of 360 nm or more and 515 nm or less. It is more preferable that the light-emitting layer emits light having a peak in a wavelength region of 380 nm or more and 505 nm or less. It is even more preferable that the light-emitting layer emits light having a peak in a wavelength region of 400 nm or more and 500 nm or less. It is even more preferable that the light-emitting layer emits light having a peak in a wavelength region of 420 nm or more and 490 nm or less. It is particularly preferable that the light-emitting layer emits light having a peak in a wavelength region of 440 nm or more and 480 nm or less, and it is even more preferable that the light-emitting layer emits light having a peak in a wavelength region of 455 nm or more and 470 nm or less. It is also extremely preferable that the light-emitting layer emits light having a peak in a wavelength region of 455 nm or more and 465 nm or less. Within the above range, good light emission, especially good blue light emission, can be obtained.

[0167] The spectral width of the emission from the light-emitting layer (half-width of the peak of the emission spectrum, FWHM) (i.e., the spectral width of the emission from an organic electroluminescent device having a light-emitting layer) is not particularly limited, but the narrower the better. Specifically, the spectral width of the emission is preferably 30 nm or less, more preferably 25 nm or less, and even more preferably 20 nm or less (lower limit value: more than 0 nm). Within the above range, emission with higher color purity can be obtained.

[0168] 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).

[0169] Hereinafter, with reference to the attached drawings, a detailed description will be given of an organic electroluminescent device according to one embodiment of the present invention further including a layer (e.g., an organic layer) other than the light-emitting layer. In the description of the drawings, the same elements are given the same reference numerals, and duplicated descriptions are omitted. In addition, the dimensional ratios of the drawings are exaggerated for the convenience of explanation, and may differ from the actual ratios.

[0170] 1 to 3 are schematic cross-sectional views showing an organic electroluminescence element (organic EL element) which is 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.

[0171] 1 is a schematic cross-sectional view showing an organic electroluminescent device according to one embodiment of the present invention. The organic electroluminescent device 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.

[0172] Fig. 2 is a cross-sectional schematic diagram showing an organic electroluminescent device according to another embodiment of the present invention. An organic electroluminescent device 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.

[0173] Fig. 3 is a cross-sectional schematic diagram showing an organic electroluminescent device according to another embodiment of the present invention. An organic electroluminescent device 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.

[0174] The substrate, and each region and layer will now be described in detail.

[0175] (Substrate 1) The organic electroluminescent device 10 may have a substrate 1. A substrate used in a general organic electroluminescent device may be used as the substrate 1. For example, the substrate 1 may be a glass substrate, a semiconductor substrate such as a silicon substrate, or a transparent plastic substrate.

[0176] (1st electrode 2) The first electrode 2 has electrical conductivity. In an organic electroluminescent device 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.

[0177] The material constituting the first electrode 2 is not particularly limited, and examples thereof include metals, metal alloys, and conductive compounds. 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), or ITZO (indium tin zinc oxide). 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 (e.g., a mixture of Ag and Mg).

[0178] 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.

[0179] 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.

[0180] (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.

[0181] 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.

[0182] For example, the hole transport region 3 may have a structure of a single layer of the hole injection layer 31 or the 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 the 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 the 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 the 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 the hole transport layer 32 / 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 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 3 is not limited to this.

[0183] 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-styrenesulfonate)), and 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'-diphenyl-benzidine), polyether ketone containing triphenylamine (TPAPEK), 4-isopropyl-4'-methyldiphenyliodonium tetrakis(pentafluorophenyl)borate, HAT-CN (dipyrazino[2,3-f:2',3'-h]quinoxaline-2,3,6,7,10,11-hexacarbonitrile), F6-TCNNQ (1,3,4,5,7,8-hexafluorotetracyano-2,6-naphthoquinodimethane), etc.

[0184] Furthermore, the hole transport layer 32 and each of the other layers constituting the hole transport region 3 are not particularly limited, but 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(naphthalen-1-yl)-N,N'-diphenyl-benzidine), TAPC (4,4'-cyclohexylidenebis[N,N-bis(4-methylphenyl)benzeneamine]), HMTPD (4,4'-bis[N,N'-(3-tolyl)amino]-3,3'-dimethylbiphenyl), mCP (1,3-bis(N-carbazolyl)benzene), the following compound H1, the following compound H2, and the following compound HT1.

[0185] [ka]

[0186] [ka]

[0187] The hole transport region 3 may further contain a charge generating material to improve conductivity, in addition to the above-mentioned hole injection material and 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.

[0188] 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 for example, a material used in a known hole buffer layer (not shown) can be used. In addition, for example, a compound that can be contained in the hole transport region 3 as described above can be used.

[0189] 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 material that is used for known electron blocking layers 33 can be used. For example, the host material contained in the above-mentioned light-emitting layer can be used, and the above-mentioned compound H-H1, which is a host material, can be used as a preferred example.

[0190] 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 200 nm or less, and more 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 electroluminescent device. 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.

[0191] 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.

[0192] (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.

[0193] (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 thereto.

[0194] 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.

[0195] The electron injection layer 51 and other layers constituting the electron transport region 5 are not particularly limited, but may contain, for example, a known electron injection material. Examples of the electron injection material include LiQ (lithium quinolate), Li 2Examples of the metal salt include lanthanum group metals such as O, BaO, and Yb, and metal halides such as LiF, NaCl, CsF, and RbCl. The electron injection layer 51 is not particularly limited, but may contain, for example, an electron transport material described below and an insulating organometallic salt. The organometallic 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 organometallic salt include metal acetate, metal benzoate, metal acetoacetate, metal acetylacetonate, and metal stearate.

[0196] 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(benzoquinolin-10-olate), ADN (9,10-di(naphthalen-2-yl)anthracene), LiQ (lithium quinolate), the following compound ET1, etc.

[0197] [ka]

[0198] 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). In addition, examples of the hole blocking material include the host material contained in the above-mentioned light-emitting layer, and the above-mentioned compound H-E1, which is a host material, is a preferred example.

[0199] 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. The thickness of the electron transport region 5 is more preferably 30 nm or more and 150 nm or less, and even more preferably 100 nm or more and 150 nm or less. Regarding 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 is 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 is 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 is 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 driving voltage. Furthermore, 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 within the above range, a substantial increase in driving voltage is suppressed, while more favorable electron transport properties are obtained.

[0200] 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.

[0201] The second electrode 6 is disposed on the electron transport region 5. The second electrode 6 has electrical conductivity. In the organic electroluminescent device 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.

[0202] 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, or 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).

[0203] 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.

[0204] 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.

[0205] 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.

[0206] 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), or N,N'-bis(naphthalen-1-yl), or the like.

[0207] The materials constituting each of the above layers and electrodes may be used alone or in combination of two or more.

[0208] 1 to 3, the above-mentioned fused ring compound, the above-mentioned composition, or the above-mentioned material for organic electroluminescent elements is preferably contained in the light-emitting layer 4, but may be contained in an organic layer other than the light-emitting layer 4. In addition, the above-mentioned fused ring compound, the above-mentioned composition, or the above-mentioned material for organic electroluminescent elements may be contained in the light-emitting layer 4 and an organic layer other than the light-emitting layer 4.

[0209] 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

[0210] The present invention will be described in more detail using the following examples and comparative examples, but the technical scope of the present invention is not limited to only the following examples.

[0211] Hereinafter, compounds 1 to 102, 201 to 203, 301 to 369, 401 to 413, and 501 to 532 respectively represent the same as compounds 1 to 102, 201 to 203, 301 to 369, 401 to 413, and 501 to 532 given as specific examples in the description of the fused ring compound above.

[0212] <Synthesis of fused ring compounds> [Synthesis of compounds 2, 14, 97, 100, 101, 201-203, and 301] [Synthesis of compound 2]

[0213] [ka]

[0214] (Synthesis of intermediate 1) Intermediate 1 was synthesized according to the synthesis method described in paragraphs

[96] to

[0105] of WO 2017 / 142310.

[0215] (Synthesis of intermediate 2) In a three-neck flask, intermediate 1 (1.0 equiv.), resorcinol (0.5 equiv.), palladium acetate (Pd(OAc) 3 , 0.02 equivalents), (2-biphenyl)di-tert-butylphosphine (JohnPhos, 0.04 equivalents), and sodium tert-butoxide (tBuONa, 2.0 equivalents) were reacted in a toluene solvent under an inert atmosphere at 100°C with stirring. After the reaction, the resulting solution was cooled to room temperature and filtered through Celite, and the filtrate was concentrated. Intermediate 2 was then obtained by purifying it using a silica gel column.

[0216] (Synthesis of Compound 2) In a three-neck flask, intermediate 2 (1.0 equivalent) was stirred in o-dichlorobenzene as a solvent under an inert atmosphere. Then, boron triiodide (BI) was added to the resulting solution. 3, 4.0 equivalents) was added and the mixture was reacted under an inert atmosphere with stirring at 180°C. After the reaction was completed, the mixture was extracted with dichloromethane and water, and the solvent in the organic layer was distilled off. The resulting product was purified by column chromatography to obtain compound 2.

[0217] [Synthesis of compound 14]

[0218] [ka]

[0219] (Synthesis of intermediate 3) Intermediate 3 was synthesized according to the synthesis method described in paragraphs

[96] to

[0105] of WO 2017 / 142310.

[0220] (Synthesis of intermediate 4) Intermediate 4 was obtained by the same synthesis method as that of intermediate 2, except that intermediate 1 was changed to intermediate 3 and resorcinol was changed to 1,3-benzenedithiol.

[0221] (Synthesis of compound 14) Compound 14 was obtained in the same manner as in the synthesis of compound 2, except that intermediate 2 was changed to intermediate 4.

[0222] [Synthesis of compound 97]

[0223] [ka]

[0224] (Synthesis of A-1) Carbazole (1.0 equivalent), 4-bromo-2-fluoronitrobenzene (1.0 equivalent), and dimethyl sulfoxide as a solvent were added to a reaction vessel. Then, cesium carbonate (1.2 equivalents) was added to the resulting mixture, and the mixture was stirred at room temperature under a nitrogen atmosphere to react. After the reaction was completed, water was added to the resulting solution, which was then extracted with chloroform, and the organic layer was washed with water. The resulting organic layer was dried over magnesium sulfate, concentrated, and recrystallized from chloroform / hexane to obtain A-1.

[0225] (Synthesis of A-2) A-1 (1.0 equivalent) and ethanol as a solvent were added to a reaction vessel, and hydrochloric acid was added to make it acidic. Then, tin(II) chloride (3.0 equivalents) was added little by little to the resulting mixture, and the mixture was stirred at 70 degrees under a nitrogen atmosphere to react. After the reaction was completed, the resulting solution was returned to room temperature and concentrated under reduced pressure to obtain a residue. A 1N aqueous solution of sodium hydroxide was added to the residue to prepare a suspension, which was stirred at room temperature to produce a solid. The resulting solid was then filtered, dissolved in toluene, and a 1N aqueous solution of sodium hydroxide was added. The mixture was then separated and dried with magnesium sulfate to obtain an organic layer. The resulting organic layer was then concentrated, and then recrystallized with toluene / hexane to obtain A-2.

[0226] (Synthesis of intermediate 5) A-2 (1.0 equivalent), acetic acid, and concentrated sulfuric acid (volume ratio 10:1, 4.5 equivalents as sulfuric acid) were added to the reaction vessel. Next, the reaction vessel was immersed in an ice-water bath under a nitrogen atmosphere to cool the reaction solution to 10 degrees. Sodium nitrite (1.02 equivalents) dissolved in water was then added dropwise to the reaction solution over 15 minutes. The reaction solution was then stirred at 130 degrees to allow the reaction to proceed. After the reaction was completed, the resulting solution was allowed to cool, and water was added to precipitate a solid. The precipitated solid was filtered and suspended and washed in methanol. The resulting solid was then purified by silica gel column chromatography and recrystallized with chloroform / ethanol to obtain the target product (intermediate 5).

[0227] [ka]

[0228] (Synthesis of intermediate 6) In a reaction vessel, 1,3-dibromo-2-chlorobenzene (1.0 equivalent), aniline (2.0 equivalent), and sodium-tert-butoxide (2.5 equivalent) were stirred in a xylene solvent. Then, butyldichlorobis[di-tert-butyl(p-dimethylaminophenyl)phosphino]palladium(II) (0.01 equivalent) was added to the resulting mixture, and the mixture was stirred at 140 degrees under a nitrogen atmosphere to react. After the reaction was completed, the resulting solution was allowed to cool, diluted with toluene, and filtered through Celite to obtain a filtrate. The resulting filtrate was concentrated and purified by column chromatography to obtain intermediate 6.

[0229] [ka]

[0230] (Synthesis of intermediate 7) In a reaction vessel, intermediate 6 (1.0 equivalent), intermediate 5 (2.0 equivalent), and sodium-tert-butoxide (2.5 equivalent) were stirred in a xylene solvent. Then, butyldichlorobis[di-tert-butyl(p-dimethylaminophenyl)phosphino]palladium(II) (0.01 equivalent) was added to the resulting mixture, and the mixture was stirred at 140 degrees under a nitrogen atmosphere to react. After the reaction was completed, the resulting solution was allowed to cool, diluted with toluene, and filtered through Celite to obtain a filtrate. The filtrate was concentrated and purified by column chromatography to obtain intermediate 7.

[0231] (Synthesis of Compound 97) In a reaction vessel, intermediate 7 (1.0 equivalent) was stirred in tert-butylbenzene solvent. Under a nitrogen atmosphere, the reaction solution was cooled to -30 degrees and 1.6M tert-butyllithium pentane solution (1.2 equivalents) was added dropwise. Next, the reaction solution was stirred at 60 degrees for 2 hours, cooled to -30 degrees, boron tribromide (1.2 equivalents) was added, and stirred at room temperature for 30 minutes. Then, the reaction solution was cooled to 0 degrees and N,N-diisopropylethylamine (2.0 equivalents) was added. Then, the mixture was stirred at 120 degrees to react, and allowed to cool to room temperature. Next, an aqueous sodium acetate solution and ethyl acetate were added to the reaction solution, and the organic layer was separated by a liquid separation operation. Then, the obtained organic layer was concentrated and purified by column chromatography to obtain compound 97.

[0232] [Synthesis of compound 100]

[0233] [ka]

[0234] (Synthesis of B-1) B-1 was obtained in the same manner as A-1, except that the starting material carbazole was changed to 3,6-di-tert-butylcarbazole.

[0235] (Synthesis of B-2) B-2 was obtained in the same manner as A-2, except that the starting material A-1 was changed to B-1.

[0236] (Synthesis of intermediate 8) Intermediate 8 was obtained in the same manner as in Intermediate 5, except that the starting material A-2 was changed to B-2.

[0237] [ka]

[0238] (Synthesis of intermediate 9) Intermediate 9 was obtained in the same manner as in intermediate 7, except that the starting material, intermediate 5, was changed to intermediate 8.

[0239] (Synthesis of Compound 100) Compound 100 was obtained in the same manner as Compound 97, except that the starting material, Intermediate 7, was changed to Intermediate 9.

[0240] [Synthesis of compound 101]

[0241] [ka]

[0242] (Synthesis of intermediate 10) Intermediate 10 was obtained in the same manner as in Intermediate 6, except that the starting material aniline was changed to 4-tert-butylaniline.

[0243] [ka]

[0244] (Synthesis of intermediate 11) Intermediate 11 was obtained in the same manner as in intermediate 7, except that the starting material, intermediate 6, was changed to intermediate 10.

[0245] (Synthesis of Compound 101) Compound 101 was obtained in the same manner as Compound 97, except that the starting material, Intermediate 7, was changed to Intermediate 11.

[0246] [Synthesis of compound 201]

[0247] [ka]

[0248] (Synthesis of compound 201) Compound 201 was obtained by synthesizing compound 201 from intermediate 7 in the same manner as compound 97, recrystallizing and column chromatographing, and then isolating compound 97 by recrystallization and purifying the compound.

[0249] [Synthesis of compound 202]

[0250] [ka]

[0251] (Synthesis of compound 202) Compound 202 was obtained by synthesizing compound 202 from intermediate 9 in the same manner as compound 100, recrystallizing and column chromatographing, and then isolating compound 100 by recrystallization and purifying the compound.

[0252] [Synthesis of compound 203]

[0253] [ka]

[0254] (Synthesis of compound 203) Compound 203 was obtained by synthesizing compound 203 from intermediate 11 in the same manner as compound 101, recrystallizing and column chromatographing, and then isolating compound 203 from compound 101 by recrystallization and purifying the compound.

[0255] [Synthesis of compound 301]

[0256] [ka]

[0257] (Synthesis of D-1) 1,3-Dichloro-2-iodobenzene (1.0 equivalent), o-anisidine (0.95 equivalent), sodium tert-butoxide (1.5 equivalent), 1,1'-bis(diphenylphosphino)ferrocene (0.05 equivalent), and palladium acetate (0.05 equivalent) were added to a reaction vessel and dissolved in toluene. The mixture was stirred at 100°C for 12 hours under a nitrogen atmosphere, and then filtered through Celite. Water was added to the resulting solution, and the organic layer was concentrated. The mixture was then purified using a silica gel column to obtain D-1 (yield 40%).

[0258] (Synthesis of D-2) D-1 (1.0 equivalent), palladium acetate (0.05 equivalent), tri-tert-butylphosphonium tetrafluoroborate (0.1 equivalent), and potassium carbonate (2.0 equivalent) were added to a reaction vessel and dissolved in N,N-dimethylacetamide. The mixture was stirred under reflux for 6 hours under a nitrogen atmosphere and then filtered through Celite. Water and ethyl acetate were then added to the resulting solution, which was then separated and the organic layer was concentrated. D-2 was then obtained by purifying the mixture using a silica gel column (yield 85%).

[0259] (Synthesis of D-3) D-2 (1.0 equivalent), 1-tert-butyl-4-iodobenzene (2.0 equivalent), copper iodide (0.1 equivalent), trans-1,2-cyclohexanediamine (0.2 equivalent), and tripotassium phosphate (2.0 equivalent) were added to a reaction vessel and dissolved in 1,4-dioxane. Water was added to the resulting solution, and the organic layer was concentrated. D-3 was then obtained by purifying the solution using a silica gel column (yield 80%).

[0260] (Synthesis of D-4) D-3 (1.0 equivalent), palladium acetate (0.05 equivalent), tri-tert-butylphosphonium tetrafluoroborate (0.1 equivalent), and potassium carbonate (2.0 equivalent) were added to a reaction vessel and dissolved in N,N-dimethylacetamide. The mixture was refluxed under nitrogen for 6 hours and then filtered through Celite. Water and ethyl acetate were then added to the resulting solution, which was then separated and the organic layer was concentrated. D-4 was then obtained by purifying the mixture using a silica gel column (yield 85%).

[0261] (Synthesis of D-5) D-4 (1.0 equivalent) was added to a reaction vessel and dissolved in dichloromethane. The reaction vessel was immersed in an ice bath, and boron tribromide (2.0 equivalent) diluted with dichloromethane was added dropwise. The reaction solution was returned to room temperature and then stirred for 2 hours. 2N hydrochloric acid was added to the reaction solution, and the solution was stirred for 30 minutes. Then, a separation operation was performed, and the organic layer was concentrated to obtain D-5 (yield 85%).

[0262] (Synthesis of D-6) D-5 (1.0 equivalent), 1-bromo-2,6-difluorobenzene (0.45 equivalent), and potassium carbonate (2.0 equivalent) were added to a reaction vessel and dissolved in N-methylpyrrolidone. After stirring at 140°C for 12 hours under a nitrogen atmosphere, the temperature was raised to 160°C and stirring was continued for another 12 hours. After the reaction was completed, water was added to the reaction solution and the precipitated solid was filtered off. Then, D-6 was obtained by purifying the product using a silica gel column (yield 85%).

[0263] (Synthesis of Compound 301) D-6 (1.0 equivalent) and tert-butylbenzene were added to a reaction vessel and stirred. Under a nitrogen atmosphere, the reaction solution was cooled to 0 degrees and 1.6M tert-butyllithium pentane solution (2.0 equivalents) was added dropwise. After stirring at 60°C for 2 hours, low boiling point components were distilled off under reduced pressure. The mixture was cooled to -30°C, boron tribromide (2.0 equivalents) was added, and the mixture was stirred at room temperature for 30 minutes. Then, the mixture was cooled to 0°C, and N,N-diisopropylethylamine (2.0 equivalents) was added. Then, the mixture was heated and stirred at 120°C for 3 hours. Water and methanol were added to the reaction solution, and the precipitated solid was filtered off. Then, the mixture was dispersed and washed with tetrahydrofuran, and compound 301 was obtained. (Yield 30%)

[0264] The structure of the fused ring compound obtained above can be confirmed by, for example, a known method (eg, NMR, LC-MS, etc.).

[0265] As a specific example, the structure of the compound 100 obtained above was determined by a nuclear magnetic resonance spectrometer ( 1 The results of identification by H-NMR are as follows: 1 H-NMR (500MHz, CD 2 Cl 2 ) δ = 9.87 (s, 2H), 8.40 (s, 2H), 8.20 (s, 2H), 8.16 (s, 2H), 7.88 (t, 4H), 7.79 (t, 2H), 7.59 (d, 4H), 7.53 (d, 2H), 7.33 (m, 3H), 7.16 (s, 2H), 6.29 (d, 2H), 1.65 (s, 18H), 1.47 (s, 18H).

[0266] As another specific example, the structure of the compound 202 obtained above was determined by a nuclear magnetic resonance spectrometer ( 1 The results of identification by H-NMR are as follows: 1 H-NMR (500MHz, CD 2 Cl 2 ) δ = 9.70 (s, 1H), 9.20 (d, 1H), 8.49 (d, 1H), 8.31 (d, 2H), 8.28 (s, 1H), 8.24 (s, 1H), 8.19 (s, 1H), 8.14 (s, 1H), 7.97 (s, 1H), 7.85 (t, 2H), 7.78 (t, 1H), 7.71 (d, 1H), 7.54 (m, 5H), 7.41 (m, 2H), 7.30 (m, 2H), 7.14 (s, 1H), 7.00 (d, 1H), 6.35 (d, 1H), 6.26 (d, 1H), 1.67 (s, 18H), 1.47 (s, 9H), 1.45 (s, 9H).

[0267] As another specific example, the structure of the compound 301 obtained above was identified by MALDI-TOF-MS (matrix-assisted laser desorption / ionization time-of-flight mass spectrometry), and the results are shown below: Measured molecular weight (compound 301): 708.75, theoretical (C50H37BN2O2): 708.29.

[0268] [Other fused ring compounds according to the present invention] In addition, fused ring compounds represented by the above general formula (1) or the above general formula (2) other than compounds 2, 14, 97, 100, 101, 201 to 203, and 301, or having a plurality of structures represented by the above general formula (1) or the above general formula (2), have a skeletal structure common to or similar to each of the compounds shown above, and therefore can be synthesized by appropriately changing the raw materials and reaction conditions used in each of the synthesis methods shown above, or by appropriately combining the above synthesis methods with known synthesis methods, etc.

[0269] <Simulation evaluation of fused ring compounds> “High-Performance Dibenzoheteraborin-Based Thermally Activated Delayed Fluorescence Emitters: Molecular Architectonics for Concurrently Achieving Narrowband Emission and Efficient Triplet-Singlet Spin Conversion” In Seob Park, Kyohei Matsuo, Naoya Aizawa, and Takuma Yasuda, Advanced Functional Materials 2018, 28, 1802031, it is reported that the spectral width of the fluorescence emission (full width at half maximum, FWHM) is approximately 10 times the width of the first excited singlet state (S 1 ) in the stable structure of the ground state (S 0 ) energy [E(S 0 @S 1 )] and the ground state (S 0 ) in the stable structure of the ground state (S 0 ) energy [E(S 0 @S 0 Reorganization energy [E(S 0 @S 1 )-E(S 0 @S 0) has been shown to be closely related to

[0270] [Relationship between rearrangement energy and fluorescence spectrum width] First, calculate the rearrangement energy [E(S 0 @S 1 )-E(S 0 @S 0 )] and the spectral width (FWHM) of the fluorescence emission were determined.

[0271] (Calculations using Density Functional Theory (DFT)) The following calculations were carried out for the following known fused ring compounds R1 to R3 by density functional theory (DFT).

[0272] [ka]

[0273] The first excited singlet state (S 1 ) in the stable structure of the ground state (S 0 )Energy [E(S 0 @S 1 )], and the ground state (S 0 ) in the stable structure of the ground state (S 0 ) energy [E(S 0 @S 0 )] and the rearrangement energy [E(S 0 @S 1 )]-[E(S 0 @S 0 )] (eV) was calculated.

[0274] In addition, the first excited singlet state (S 1 ) in the first excited singlet state (S 1 ) energy [E(S 1 @S 1 )] and compare this value with the ground state (S 0 ) in the stable structure of the ground state (S0 ) energy [E(S 0 @S 0 )], the first adiabatic excited singlet state (S 1 )Energy [E(S 1 @S 1 )]-[E(S 0 @S 0 )] (eV) was calculated.

[0275] And the adiabatic first excited singlet state (S 1 ) Energy (eV) was converted to light wavelength (nm) and the fluorescence wavelength (nm) was calculated.

[0276] In addition, the first excited singlet state (S 1 ) was calculated.

[0277] In addition, the HOMO (Highest Occupied Molecular Orbital) energy and the LUMO (Lowest Unoccupied Molecular Orbital) energy were calculated.

[0278] Here, the density functional theory (DFT) calculations were performed using Gaussian 16 (Gaussian Inc.) as calculation software, using the following calculation methods (I), (II), and (III): (I) S 0 Calculation method: Functional B3LYP, basis set 6-31G(d,p), geometry optimization calculation using DFT including toluene solvent effect (PCM); (II) S 1 Calculation method: Geometry optimization calculations using the functional B3LYP, basis set 6-31G(d,p), and time-dependent DFT (TDDFT) including the toluene solvent effect (PCM); (III) S 0 Calculation method: Functional B3LYP, basis set 6-31G(d,p), calculation on input structure using DFT including toluene solvent effect (PCM).

[0279] More specifically, the calculations for each item were performed using the following calculation methods: Ground state (S 0 ) in the stable structure of the ground state (S 0 ) energy [E(S 0 @S 0 )]: the calculation method of (I) above; First excited singlet state (S 1 ) in the first excited singlet state (S 1 )) of the energy [E(S 1 @S 1 )]: the calculation method of (II) above; First excited singlet state (S 1 ) in the stable structure of the ground state (S 0 )Energy [E(S 0 @S 1 )]: the calculation methods (II) and (III) above; Rearrangement energy [E(S 0 @S 1 )]-[E(S 0 @S 0 )]: the calculation methods (I), (II) and (III) above; Adiabatic first excited singlet state (S 1 )Energy [E(S 1 @S 1 )]-[E(S 0 @S 0 )]: the calculation methods (I) and (II) above; Fluorescence wavelength (nm): calculation method (I) above and (II) above; First excited singlet state (S 1 ) oscillator strength f in the stable structure: calculation method (II) above; HOMO and LUMO: Calculation method (I) above.

[0280] FIG. 4 is an explanatory diagram qualitatively explaining the relationship between the energies.

[0281] The results are shown in Table 1 below.

[0282] (Measurement of the spectral width (FWHM) of fluorescence emission) 1×10 of condensed ring compounds R1 to R3 -5 M (=mol / dm 3 For each of the toluene solutions (mol / L), measurements were performed at room temperature using a Hitachi High-Tech Science Corporation (formerly Hitachi High-Technologies Corporation) F7000 spectrofluorophotometer with an excitation wavelength of 320 nm to evaluate the peak wavelength (nm) of fluorescent emission in photoluminescence (PL) and the spectral width of the fluorescent emission (full width at half maximum, FWHM) of the fluorescent emission.

[0283] The results are shown in Table 1 below.

[0284] [Table 1]

[0285] From the results in Table 1 above, it was confirmed that the color of the fluorescence wavelength (nm) calculated by the density functional theory calculation and the actually measured peak wavelength are somewhat close to each other. This confirmed that the color predicted by the density functional theory calculation and the actually measured color are similar.

[0286] Here, a graph of the FWHM of the fluorescence emission in the actually measured PL vs. the rearrangement energy (eV) calculated by the density functional theory for the fused ring compounds R1 to R3 is shown in Figure 5. From the results in Figure 5, it was confirmed that there is a correlation between the rearrangement energy (eV) calculated by the density functional theory and the FWHM of the fluorescence emission, and that the smaller the rearrangement energy (eV), the smaller the FWHM of the fluorescence emission, i.e., the narrower the spectral width of the fluorescence emission.

[0287] [Calculation of rearrangement energy of the compound of the present invention and the comparative compound] Calculations were performed by density functional theory in the same manner as above for the above compounds 1 to 102, 201 to 203, 301 to 369, 401 to 413, and 501 to 532, which are fused ring compounds of the present invention. In addition, calculations were performed by density functional theory in the same manner as above for the following comparative compounds C1 to C3, which are outside the scope of the present invention and do not have an aromatic cyclic group represented by the above chemical formula (3).

[0288] [ka]

[0289] For these compounds, the calculated HOMO (eV), LUMO (eV), and first adiabatic excited singlet state (S 1 The results of the energy (eV), fluorescence wavelength (nm), oscillator strength f, and rearrangement energy (eV) are shown in Tables 2 to 8 below.

[0290] [Table 2]

[0291] [Table 3]

[0292] [Table 4]

[0293] [Table 5]

[0294] [Table 6]

[0295] [Table 7]

[0296] [Table 8]

[0297] Here, as shown in the results of Tables 1 to 8, the compounds 1 to 102, 201 to 203, 301 to 369, 401 to 413, and 501 to 532, which are the fused ring compounds of the present invention, have rearrangement energies of 0.100 eV or less, which are smaller than those of the known fused ring compounds R1 to R3. From this, referring to FIG. 5, it is presumed that the FWHM of the fused ring compounds of the present invention is smaller than those of the known fused ring compounds R1 to R3. And, it is presumed that the color purity of the fused ring compounds of the present invention is also higher than those of the known fused ring compounds R1 to R3, and that the fused ring compounds of the present invention exhibit extremely high color purity.

[0298] On the other hand, the comparative compounds C1 to C3 have rearrangement energies of 0.114 eV or more, which are equal to or greater than those of the known fused ring compounds R1 to R3. From this, referring to FIG. 5, it is estimated that the FWHM of the comparative compounds C1 to C3 is equal to or greater than those of the known fused ring compounds R1 to R3. It is also estimated that the color purity of the comparative compounds C1 to C3 is equal to or lower than those of the known fused ring compounds R1 to R3.

[0299] As shown in Tables 2 to 8, the fused ring compounds of the present invention, Compounds 1 to 102, 201 to 203, 301 to 369, 401 to 413, and 501 to 532, have significantly smaller rearrangement energy (eV) values ​​than the comparative compounds C1 to C3. From this, it is presumed that the FWHM of the fused ring compounds of the present invention is significantly smaller than that of the comparative compounds C1 to C3. It is also presumed that the color purity of the fused ring compounds of the present invention is significantly higher than that of the comparative compounds C1 to C3.

[0300] From these findings, it was confirmed that the fused ring compound of the present invention is expected to emit fluorescent light with a very narrow spectral width and high color purity, in particular blue fluorescent light with high color purity.

[0301] It was also confirmed that the fused ring compound of the present invention has a sufficiently large oscillator strength f and is excellent in fluorescence emission efficiency.

[0302] <Experimental evaluation of fused ring compounds> The properties of the fused ring compounds of the present invention were confirmed by experiments. In the following experiments, Compound 100, Compound 202, and Compound 301 were used as representative fused ring compounds of the present invention.

[0303] (Measurement of the spectral width (FWHM) of fluorescence emission) Compound 100, Compound 202 and Compound 301 according to the present invention at 1×10 -5 M (=mol / dm 3 For each of the toluene solutions (mol / L), measurements were performed at room temperature using a Hitachi High-Tech Science F7000 spectrofluorophotometer with an excitation wavelength of 320 nm to evaluate the peak wavelength (nm) of fluorescent emission in photoluminescence (PL) and the spectral width of the fluorescent emission (full width at half maximum, FWHM) of the peak.

[0304] In this evaluation, the peak wavelength of the fluorescent light is not particularly limited, but is preferably within the blue light emission region, and is particularly preferably 440 nm or more and 465 nm or less.

[0305] In this evaluation, it is determined that the smaller the spectral width FWHM of the fluorescent emission, the more preferable it is, and the higher the color purity is.

[0306] The results are shown in the following Table 9. Table 9 also shows the results of fused ring compounds R1 to R3, which were measured in the same manner as above.

[0307] [Table 9]

[0308] <Fabrication of organic electroluminescence element (organic electroluminescence element, organic EL element)> [Fabrication of organic EL elements] (Element Example 1) The ITO glass substrate was cut to a size of 50 mm x 50 mm x 0.5 mm, and ultrasonically cleaned in acetone, isopropyl alcohol, and pure water, in that order, for 15 minutes each, and then UV ozone cleaned for 30 minutes. The following layers were deposited on the ITO electrode (anode) on this glass substrate using a vacuum deposition device.

[0309] First, F6-TCNNQ was evaporated on the ITO electrode to form a hole injection layer having a thickness of 10 nm. Next, compound HT1 was evaporated on the hole injection layer to form a hole transport layer having a thickness of 126 nm. Next, compound H-H1 was evaporated on the hole transport layer to form an electron blocking layer having a thickness of 10 nm. In this way, a hole transport region was formed.

[0310] Compound H-H1, compound H-E1, and the compound 100 obtained above were co-deposited on the hole transport region to form a 40 nm thick light emitting layer. Here, the light emitting layer was formed so that the mass ratio of compound H-H1 and compound H-E1 in the light emitting layer was compound H-H1: compound H-E1 = 60: 40. The light emitting layer was also formed so that the concentration of compound 100 in the light emitting layer was 1.5 mass % with respect to the total mass of compound H-H1, compound H-E1, and compound 100 (i.e., the total mass of the light emitting layer). Compound H-H1 and compound H-E1 are host materials.

[0311] Compound H-E1 was vacuum-deposited on the light-emitting layer to form a hole-blocking layer having a thickness of 10 nm. Compound ET1 and LiQ were then co-deposited on the hole-blocking layer in a mass ratio of compound ET1:LiQ=5:5 (unit: parts by mass) to form an electron-transporting layer having a thickness of 36 nm. LiQ was then vapor-deposited on the electron-transporting layer to form an electron-injecting layer having a thickness of 0.5 nm. In this manner, an electron-transporting region was formed.

[0312] An 80 nm thick Al (cathode) was deposited on the electron injection layer by vapor deposition to prepare an organic EL device.

[0313] After that, in a nitrogen atmosphere glove box with a moisture concentration of 1 ppm or less and an oxygen concentration of 1 ppm or less, the organic EL element produced in the above process was sealed using a glass sealing tube with a desiccant and an ultraviolet curing resin (MORESCO, product name WB90US). In this way, the organic EL element was completed.

[0314] [ka]

[0315] (Element Example 2) An organic EL element was produced in the same manner as in Device Example 1, except that in the formation of the light-emitting layer, Compound 100 in the light-emitting layer was changed to Compound 202, and the organic EL element was then sealed to complete the production.

[0316] (Element Example 3) An organic EL element was produced and sealed in the same manner as in Example 1, except that the film formation of the light-emitting layer was changed as follows, to complete the organic EL element.

[0317] <<Formation of the light-emitting layer of element example 3>> Compound H-H1, compound H-E1, phosphorescent complex Pt1, and the compound 100 obtained above were co-deposited on the hole transport region to form a 40 nm thick light emitting layer. Here, the light emitting layer was formed so that the mass ratio of compound H-H1, compound H-E1, and phosphorescent complex Pt1 in the light emitting layer was compound H-H1: compound H-E1: phosphorescent complex Pt1 = 60: 40: 10. The light emitting layer was also formed so that the concentration of compound 100 in the light emitting layer was 1.5 mass% with respect to the total mass of compound H-H1, compound H-E1, phosphorescent complex Pt1, and compound 100 (i.e., the total mass of the light emitting layer). Compound H-H1 and compound H-E1 are host materials.

[0318] [ka]

[0319] (Element Example 4) An organic EL element was produced in the same manner as in Device Example 3, except that in the formation of the light-emitting layer, Compound 100 in the light-emitting layer was changed to Compound 202, and the organic EL element was sealed to complete the production.

[0320] (Comparative element example 1) An organic EL element was produced in the same manner as in Device Example 1, except that in the formation of the light-emitting layer, Compound 100 in the light-emitting layer was changed to Compound R1, and the organic EL element was then sealed to complete the production.

[0321] <Evaluation of organic EL elements> [Luminance, external quantum efficiency and device life] According to the following method, brightness is 1,000cd / m 2 The results of evaluation of the emission peak wavelength, emission spectrum width (full width at half maximum of the emission spectrum peak, FWHM), external quantum efficiency, and element lifetime are shown in Table 10 below. LT95 in Table 10 below represents the evaluation result of element lifetime. Here, LT95 in Table 10 below is shown as a relative value with the LT95 [hr] of element comparative example 1 set as 1. Details of LT95 will be described below.

[0322] Using a DC constant voltage power supply (KEITHLEY, source meter type 2400), the organic EL element was made to emit light while changing the applied voltage, and the luminance, emission spectrum, and amount of light emitted at this time were measured using a luminance measuring device (Topcon, SR-3).

[0323] Here, the external quantum efficiency was calculated from the emission spectrum, the amount of light emitted, and the current value during measurement.

[0324] In addition, the element life (durability) is at an initial brightness of 1,000 cd / m 2The device was continuously driven at a current value of 0.01V, and the time it took for the light emission brightness to decrease over time to 95% of the initial brightness was measured as "LT95."

[0325] [Emission peak wavelength and emission spectral width (FWHM)] The emission peak wavelength and the emission spectrum width (full width at half maximum of the emission spectrum peak, FWHM) were read from the measurement results of the emission spectrum.

[0326] In this evaluation, the peak wavelength of the emission is not particularly limited, but is preferably within the blue emission region, and is particularly preferably 455 nm or more and 470 nm or less.

[0327] In this evaluation, it is determined that the smaller the emission spectrum width FWHM, the more preferable it is, and the higher the color purity is.

[0328] [Table 10]

[0329] The results in Table 9 above confirm that Compound 100, Compound 202, and Compound 301, which are the fused ring compounds of the present invention, exhibit blue fluorescent emission with a very narrow spectral width and high color purity in PL fluorescence emission.

[0330] The results in Table 10 above also confirm that Compounds 100 and 202, which are fused ring compounds of the present invention, emit blue fluorescent light with a very narrow spectral width and high color purity in an organic EL device. Also, Compounds 100 and 202, which are fused ring compounds of the present invention, are excellent in external quantum efficiency, and therefore are excellent in luminous efficiency and device life.

[0331] Furthermore, it was confirmed that the device examples 3 and 4, which combine the fused ring compounds of the present invention, Compound 100 and Compound 202, with the phosphorescent complex Pt1, have the same emission peak wavelength and emission spectrum width (FWHM) as the device examples 1 and 2, which use the same fused ring compounds of the present invention alone, and the external quantum efficiency and LT95 are significantly increased. This shows that the luminous efficiency and device life are significantly improved by combining the fused ring compound of the present invention with a phosphorescent compound. In other words, the remarkable effectiveness of the present invention when these combinations are adopted is demonstrated.

[0332] These results tended to coincide with the results in the above simulation evaluation that the rearrangement energy of the fused ring compound of the present invention is smaller than that of the known fused ring compounds R1 to R3, and that the FWHM of the fused ring compound of the present invention is smaller than that of the known fused ring compounds R1 to R3, as shown in Figure 5. From this, it is presumed that the organic electroluminescent device using the fused ring compound of the present invention exhibits fluorescent emission with a narrower spectral width and high color purity, particularly blue fluorescent emission with high color purity, compared with the organic electroluminescent device using the comparative compounds C1 to C3, which are outside the scope of the present invention and do not have the aromatic cyclic group represented by the chemical formula (3).

[0333] In the above experiments, Compound 100, Compound 202, and Compound 301 were used as representative fused ring compounds of the present invention. However, as represented by the above simulation evaluation, it is presumed that other fused ring compounds of the present invention also have similar properties. From this, it is considered that other fused ring compounds of the present invention and organic EL devices using the same also exhibit similar fluorescent emission with high color purity, particularly blue fluorescent emission with high color purity. In addition, it is considered that organic EL devices using other fused ring compounds of the present invention also exhibit excellent luminous efficiency and excellent device life. [Explanation of symbols]

[0334] 1 Board 2 1st electrode 3. Hole transport region 31 Hole injection layer 32 Hole transport layer 33 Electron blocking layer 4. Light-emitting layer 5 Electron transport area 51 Electron injection layer 52 Electron transport layer 53 Hole blocking layer 6 Second electrode 10 Organic electroluminescent device.

Claims

1. A composition comprising at least one fused ring compound selected from the group consisting of compounds 97, 100 to 102, and 201 to 203 below, and a phosphorescent compound, wherein the phosphorescent compound comprises a platinum complex. 【Chemistry 1-1】 【Chemistry 1-2】

2. The composition described in claim 1, wherein the fused ring compound is at least one selected from the group consisting of compound 100 and compound 202.

3. The composition described in claim 1 or 2, wherein the platinum complex comprises at least one selected from the group consisting of the following compounds: 【Chemistry 2-1】 【Chemistry 2-2】 【Chemistry 2-3】 【Chemistry 2-4】

4. The composition described in claim 3, wherein the platinum complex comprises at least one selected from the group consisting of the following compounds: 【Chemistry 3-1】 【Chemistry 3-2】

5. The composition described in claim 4, wherein the platinum complex comprises the following compound: 【Chemistry 4】

6. A material for an organic electroluminescent device, comprising the composition according to any one of claims 1 to 5.

7. An electronic device comprising the composition according to any one of claims 1 to 5, or the material for an organic electroluminescent device according to claim 6.

8. An organic electroluminescent device comprising a first electrode, a second electrode, and a single or multiple organic layers disposed between the first electrode and the second electrode, wherein at least one of the organic layers comprises the composition according to any one of claims 1 to 5 or the material for organic electroluminescent devices according to claim 6.

9. The organic electroluminescent device of claim 8, wherein the organic layer containing the composition or the material for the organic electroluminescent device comprises an emitting layer.

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