Compound and organic electroluminescent element

Abstract

To provide a compound having a peak wavelength of an emission spectrum within a blue wavelength region, and capable of realizing emission of high purity and high efficiency, and an organic electroluminescent element having an emission layer containing the compound.SOLUTION: The present invention relates to compounds having a specific nitrogen-containing condensed ring structure. Furthermore, the present invention also relates to an organic electroluminescent element having a light-emitting layer that includes compounds with a specific nitrogen-containing condensed ring structure. Additionally, the present invention also relates to an organic electroluminescent element with a light-emitting layer that includes compounds having a specific nitrogen-containing condensed ring structure and phosphorescent complexes.SELECTED DRAWING: None

Description

[Technical field]

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

[0002] In recent years, organic electroluminescence elements (hereinafter also referred to as "organic EL elements") have been used as various light-emitting devices including smartphones and televisions. A light-emitting material is used in the light-emitting layer of an organic EL element, and as light-emitting materials, fluorescent materials, phosphorescent materials, thermally delayed activation fluorescent materials, etc. have been reported (Non-Patent Document 1). Due to the light-emitting principle of organic EL elements, organic EL elements using fluorescent materials that utilize only fluorescent emission from singlet have been put to practical use, but the luminous efficiency of normal organic EL elements is 5% or less. In addition, organic EL elements using phosphorescent materials have a luminous efficiency of over 20%, and have already been put to practical use in green and red. However, fluorescent emission is still used for blue from the viewpoint of element life, and there is a demand for improved performance.

[0003] In recent years, as a method for improving the luminous efficiency while extending the life of organic EL elements, an organic EL element with a light-emitting method combining a phosphor sensitizer and a light-emitting material has been proposed (Non-Patent Document 2). In conventional organic EL elements, a host material and a light-emitting material are used in the light-emitting layer, and excitons generated on the molecules of the host material in the light-emitting layer transfer energy to the light-emitting material to emit light. In this case, if a fluorescent material is used as the light-emitting material, the light-emitting efficiency is a maximum of 5%. However, if a phosphor sensitizer is added to the light-emitting layer, triplet energy, which was previously unavailable, can also be used for light emission, improving the light-emitting efficiency of the organic EL element to 10% or more. It has also been reported that the element life is longer than that when a phosphor sensitizer is used as the light-emitting material, and it is attracting attention as a candidate for the next generation of organic EL elements.

[0004] In recent years, BT.2100, a new international standard for television broadcasting, has been announced, and in order to comply with this standard, further improvements in the color purity of the emission wavelength of light-emitting elements are required. By introducing a microcavity structure into organic EL light-emitting elements using conventional light-emitting materials, the color purity is improved and the half-width of the emission wavelength is narrowed. However, in the case of light-emitting elements with a wide spectrum, light that deviates from the target wavelength is not utilized, which causes a problem of reduced luminous efficiency of the light-emitting element. Therefore, there is a demand for light-emitting materials with a narrower half-width of the emission spectrum.

[0005] In order to reduce the half-width of the emission spectrum of a light-emitting material, it is necessary to suppress vibrational excitation within the molecule and to minimize the change in molecular conformation and bond length between the ground state and the excited state. In order to suppress the molecular conformation, a condensed compound in which the bond distance between atoms is suppressed is desirable. The synthesis and basic physical properties of nitrogen-containing condensed polycyclic compound S1, which has a blue emission wavelength, are reported in Non-Patent Documents 3 and 4. In the report, it is shown that nitrogen-containing condensed polycyclic compound S1 is promising as a light-emitting material because it gives an emission spectrum with a small Stokes shift and a narrow half-width in a solution state.

[0006] [ka]

[0007] In addition, it has been reported that a derivative having a nitrogen-containing condensation compound S1 as a basic skeleton is applied to an organic electronic device. Patent Document 1 reports that when a derivative of the nitrogen-containing condensation compound S1 is used as an active layer of an organic transistor, it shows p-type channel characteristics and high hole mobility. Patent Document 2 reports that a derivative of the nitrogen-containing condensation compound S1 into which an aryl group is introduced as a substituent functions as a light-emitting material for an organic EL device, and the organic EL device shows high light-emitting efficiency. Thus, it can be seen that the nitrogen-containing condensation compound S1 is excellent as a basic skeleton of an organic semiconductor material. Patent Document 2 also shows that an organic EL device using a derivative of the nitrogen-containing condensation compound S1 as a light-emitting material in combination with a phosphorescent complex can be fabricated with a light-emitting efficiency of 5% or more, blue light emission with a half-width of 20 nm or less, and a small spectral half-width. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] International Publication No. 2013 / 084805 [Patent Document 2] JP 2020-107742 A [Non-patent literature]

[0009] [Non-Patent Document 1] Adachi Chihaya (ed.), "Device Properties of Organic Semiconductors", Kodansha, March 22, 2012 [Non-Patent Document 2] Nature Communications, 2018, 9, 4990. DOI:10.1038 / s41467-018-07432-2 [Non-Patent Document 3] Tetrahedron. 2013, 69, 3302-3307 [Non-Patent Document 4] New J. Chem.. 2010, 34, 1243-1246 Summary of the Invention [Problem to be solved by the invention]

[0010] However, further improvement in efficiency (superior luminous efficiency) is required for practical use in current organic EL devices. That is, further improvement in efficiency (superior luminous efficiency) is required for practical use of derivatives having the nitrogen-containing condensation compound S1 as a basic skeleton in current organic EL devices.

[0011] Therefore, an object of the present invention is to provide a compound having a peak wavelength of an emission spectrum in the blue wavelength region, high color purity, and capable of realizing highly efficient emission. Another object of the present invention is to provide an organic electroluminescence device having an emission layer containing the compound. And, another object of the present invention is to provide a means for realizing an organic electroluminescence device having a peak wavelength of an emission spectrum in the blue wavelength region, high color purity, and highly efficient emission. [Means for solving the problem]

[0012] In order to solve the above problems, the present inventors have conducted intensive research. The present inventors have found that the above problems can be solved by a compound having a specific nitrogen-containing condensed ring structure, and by forming an organic electroluminescent element with an emitting layer containing the compound, particularly by forming an emitting layer containing the compound in combination with a phosphorescent material. As a result, the present inventors have completed the present invention. Although the use of the compound is not limited to this method, by being contained in the emitting layer, particularly by being contained in the emitting layer in combination with a phosphorescent material, the organic electroluminescent element can have a significantly high efficiency (significantly excellent luminous efficiency).

[0013] That is, at least one of the above-mentioned objects of the present invention can be achieved by the following means: A compound represented by the following formula (1):

[0014] [ka]

[0015] In formula (1), R 1 ~R 16 At least one of the following formula (2):

[0016] [ka]

[0017] (* indicates the bonding position to the benzene ring) R other than the above-mentioned substituent W 1 ~R 16 each independently represents the following (a1) to (a10): (a1) a hydrogen or deuterium atom; (a2) a halogen atom; (a3) a cyano group; (a4) a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms; (a5) a substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms; (a6) a substituted or unsubstituted arylamino group having 6 to 20 carbon atoms; (a7) a substituted or unsubstituted triarylsilyl group, an alkyldiarylsilyl group, a dialkylarylsilyl group, or a trialkylsilyl group (wherein the aryl group is an aryl group having from 6 to 20 carbon atoms; and the alkyl group is an alkyl group having from 1 to 20 carbon atoms); (a8) a substituted or unsubstituted aromatic hydrocarbon group having 6 to 30 carbon atoms; (a9) a substituted or unsubstituted heterocyclic group having 3 to 30 ring atoms; and (a10)R 1 ~R 16 A substituted or unsubstituted saturated hydrocarbon group or saturated heterocyclic group having 5 to 9 ring atoms formed by bonding two adjacent groups among the above; is any atom or group of

[0018] At least one of the above-mentioned objects of the present invention can be achieved by the following means: In the compound represented by the above formula (1), R 2 , R 3 , R 6 , R 7 , R 10 , R 11 , R 14 and R 15 At least two of the following are the substituent W:

[0019] At least one of the above-mentioned objects of the present invention can be achieved by the following means: An organic electroluminescence device having a light-emitting layer containing a compound having a structure represented by the above formula (1).

[0020] At least one of the above-mentioned objects of the present invention can be achieved by the following means: An organic electroluminescence device having an emitting layer containing a compound having a structure represented by the above formula (1) and a phosphorescent complex. Effect of the Invention

[0021] According to one embodiment of the present invention, it is possible to provide a compound having an emission spectrum with a peak wavelength in the blue wavelength region, with high color purity, and with high efficiency. According to another embodiment of the present invention, it is possible to provide an organic electroluminescence element including the compound. According to another embodiment of the present invention, it is possible to provide a means for realizing an organic electroluminescence element having an emission spectrum with a peak wavelength in the blue wavelength region, with high color purity, and with high efficiency. [Brief description of the drawings]

[0022] [Figure 1] 1 is a schematic cross-sectional view showing an organic electroluminescence element according to one embodiment of the present invention. [Diagram 2]FIG. 4 is a schematic cross-sectional view showing an organic electroluminescence element according to another embodiment of the present invention. [Diagram 3] FIG. 4 is a schematic cross-sectional view showing an organic electroluminescence element according to another embodiment of the present invention. [Figure 4] 1 shows emission spectra of a toluene solution of a compound according to one embodiment of the present invention and a comparative compound. [Diagram 5] 1 shows an emission spectrum of a thin film formed by co-evaporating a compound according to one embodiment of the present invention or a comparative compound and a host compound. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0023] Hereinafter, the embodiments of the present invention will be described. Note that the present invention is not limited to the following embodiments, and can be modified in various ways within the scope of the claims. In addition, the embodiments described in this specification can be combined in any manner to form other embodiments.

[0024] In this specification, "X to Y" means "X or more and Y or less", with the numerical values ​​(X and Y) written before and after it being included as the lower and upper limits. In this specification, "P and Q are each independently" means that P and Q may be the same or different. In this specification, "A and / or B" means that A and B are each included, and a combination thereof. In addition, unless otherwise specified, the concentration and % represent mass concentration and mass %, respectively, and the ratio is mass ratio, unless otherwise specified. In addition, unless otherwise specified, the operation and measurement of physical properties are performed under the conditions of room temperature (20 to 25°C) / relative humidity 40 to 50% RH.

[0025] In addition, in this specification, the term "group derived from a ring" refers to a group obtained by removing hydrogen atoms directly bonded to ring-forming atoms from a ring structure in an amount equal to the valence, resulting in a free valence. Here, the ring-forming atoms refer to atoms that directly form the ring structure. For example, in the case of a benzene ring, the ring-forming atoms are carbon atoms, and hydrogen atoms are not included in the ring-forming atoms.

[0026] According to the present invention, a compound capable of realizing high efficiency of an organic EL device without impairing optical properties is provided. In the present invention, in consideration of existing technologies, a compound in which a bulky substituent 2,4,6-tri-tert-butylphenyl group (substituent W; a substituent represented by formula (2)) is introduced into a nitrogen-containing condensation compound S1, that is, a compound represented by formula (1), which is expected to have a high aggregation suppression effect, has been designed as a method for achieving high efficiency of an organic EL device without impairing the optical properties of a light-emitting material. The compound represented by formula (1) makes it possible to provide a blue light-emitting material having a narrow spectrum width emission with an emission peak wavelength of 440 to 480 nm and an emission spectrum width (FWHM; full width at half maximum) of 20 nm or less, a composition using the same, an organic EL device, and an organic EL display equipped with the organic EL device. In the present invention, the substituent represented by formula (2) may be referred to as "substituent W" or "2,4,6-tri-tert-butylphenyl group" hereinafter.

[0027] <Compound represented by formula (1)> The present invention relates to a compound represented by the following formula (1):

[0028] [ka]

[0029] In formula (1), R 1 ~R 16 At least one of the following formula (2):

[0030] [ka]

[0031] (* indicates the bonding position to the benzene ring) R other than the above-mentioned substituent W 1 ~R 16each independently represents the following (a1) to (a10): (a1) a hydrogen or deuterium atom; (a2) a halogen atom; (a3) a cyano group; (a4) a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms; (a5) a substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms; (a6) a substituted or unsubstituted arylamino group having 6 to 20 carbon atoms; (a7) a substituted or unsubstituted triarylsilyl group, an alkyldiarylsilyl group, a dialkylarylsilyl group, or a trialkylsilyl group (wherein the aryl group is an aryl group having from 6 to 20 carbon atoms; and the alkyl group is an alkyl group having from 1 to 20 carbon atoms); (a8) a substituted or unsubstituted aromatic hydrocarbon group having 6 to 30 carbon atoms; (a9) a substituted or unsubstituted heterocyclic group having 3 to 30 ring atoms; and (a10)R 1 ~R 16 A substituted or unsubstituted saturated hydrocarbon group or saturated heterocyclic group having 5 to 9 ring atoms formed by bonding two adjacent groups among the above; is any atom or group of

[0032] Hereinafter, the compound represented by formula (1) according to the present invention may be simply referred to as "a compound of formula (1)".

[0033] The present inventors presume that the mechanism by which the above-mentioned configuration solves the problem is as follows.

[0034] The emission wavelength of a light-emitting material varies not only with the skeletal structure but also with the type of substituent. As a result of the introduction of a specific substituent (substituent W) into the compound of formula (1), the peak wavelength of the emission spectrum is lengthened so that it falls within the blue wavelength region. As a result, the compound satisfies sufficient characteristics as a light-emitting material for an organic electroluminescence element, particularly as a blue light-emitting material. In particular, the introduction of a substituent suppresses intermolecular aggregation, improves the solubility of the molecule itself, and improves the accuracy of purification, thereby improving the color purity of the emitted light.

[0035] When the highly planar nitrogen-containing condensation compound S1 is used as an emitting material for an organic electroluminescence device, the distance from adjacent host molecules in the emitting layer becomes short, and Dexter-type energy transfer is likely to occur. In addition, because the nitrogen-containing condensation compound S1 is a planar molecule, aggregation of the emitting materials is likely to occur, and it is thought that the color purity of the emission spectrum will decrease if aggregation occurs. Therefore, as a means to solve these problems, we devised a method of introducing a three-dimensionally bulky substituent into the nitrogen-containing condensation compound S1.

[0036] Known bulky substituents include a mesityl group, a p-tert-butylphenyl group, and a 3,5-di-tert-butylphenyl group, and compounds in which these substituents are introduced into the molecular skeleton or the aryl group of a diarylamino group have been reported as luminescent materials (e.g., JP 2012-176928 A, WO 2017 / 188111 A, etc.).

[0037] These bulky substituents are generally introduced by the Suzuki-Miyaura coupling reaction or the Buchwald-Hatwig reaction to form carbon-carbon or carbon-nitrogen bonds. When introducing these substituents into compounds, the o-position substituents of aryl groups such as mesityl groups are not bulky and do not inhibit the reaction, so they can be easily introduced.

[0038] The present inventors considered introducing a 2,4,6-tri-tert-butylphenyl group into the nitrogen-containing condensation compound S1 in order to obtain a compound having a bulkier substituent. However, when they attempted to synthesize the nitrogen-containing condensation compound S1 by introducing a 2,4,6-tri-tert-butylphenyl group (substituent W) into the nitrogen-containing condensation compound S1 by the Suzuki-Miyaura coupling reaction, they were unable to obtain the desired compound. It is believed that the 2,4,6-tri-tert-butylphenyl group does not proceed in the Suzuki-Miyaura coupling reaction because a bulky tert-butyl group is present at the o-site (ortho site) of the phenyl group.

[0039] As a result of intensive research, the present inventors have found that a 2,4,6-tri-tert-butylphenyl group (substituent W) can be introduced into a nitrogen-containing condensation compound S1 by utilizing the Negishi coupling reaction, and that a compound of formula (1) can be produced. The inventors have also found that the compound of formula (1) thus obtained exhibits excellent luminescence properties, and have thus completed the present invention.

[0040] For example, in the benzene rings located on the outer sides of the compound of formula (1) (four benzene rings other than the central benzene ring), there are four positions to introduce a substituent. For example, the substitution positions of the benzene ring are set to positions 1 to 4 in order from the side closest to the condensed carbon atom closest to the nitrogen atom (for example, R 1 ~R 4 In the benzene ring having R 1 is ranked 1st, R 2 2nd place, R 3 3rd place, R 4 4th place; R 5 ~R 8 In the benzene ring having R 5 is ranked 1st, R 6 2nd place, R 7 3rd place, R 8 In the present invention, the compound of formula (1) can exhibit excellent optical properties regardless of the position of the benzene ring to which the substituent W is introduced, but it is preferable that the substituent W is introduced at either the 2-position or the 3-position, and it is more preferable that the two opposing benzene rings each have a substituent W at the 2-position or the 3-position.

[0041] As described above, it is presumed that the compound of formula (1) suppresses Dexter-type energy transfer, while the bulkiness of the substituent W makes it more difficult for the molecules of the compound of formula (1) to approach each other. This suppresses the aggregation between the molecules of the compound of formula (1). In general light-emitting materials, the aggregation between the molecules causes light emission due to the aggregation state, which tends to broaden the width of the emission spectrum and reduce color purity. However, the compound of formula (1) is less likely to cause aggregation between the molecules, so that the color purity is less likely to decrease and light emission with high color purity can be achieved. In addition, as a result of these, the luminous efficiency can be improved. When the amount of the compound of formula (1) added is increased, aggregation is more likely to occur, but the compound of formula (1) is suppressed from causing aggregation even when the amount of the compound added is increased, and light emission with high color purity and high efficiency can be achieved. In addition, when the compound of formula (1) is used in combination with a phosphorescent complex, it is also possible to achieve a significant increase in the efficiency of an organic electroluminescence element. As described above, it is believed that the compound of formula (1) can maintain excellent optical properties and exhibit high luminous efficiency when used as a light-emitting material in an organic EL device.

[0042] 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.

[0043] Thus, one aspect of the present invention relates to a compound represented by the above formula (1). Another aspect of the present invention also relates to an organic electroluminescence device having an emitting layer containing the compound represented by the above formula (1). And, another aspect of the present invention also relates to an organic electroluminescence device having an emitting layer containing a compound represented by the following formula (1) and a phosphorescent complex described below.

[0044] Hereinafter, the compound represented by the above formula (1) according to one embodiment of the present invention and the compound represented by the above formula (1) contained in the light-emitting layer of the organic electroluminescence element according to one embodiment of the present invention will be described.

[0045] In the above formula (1), R 1 ~R 16 At least one of the following formula (2):

[0046] [ka]

[0047] In this embodiment, R 1 ~R 16 Preferably, two of R are substituents W (2,4,6-tri-tert-butylphenyl groups). 1 ~R 16 Any of the above may be the substituent W, but in the above formula (1), R 2 , R 3 , R 6 , R 7 , R 10 , R 11 , R 14 and R 15 More preferably, at least two of R are substituents W. 1 ~R 16 When two of the groups are W, for example, R 2 and R 9 ;R 3 and R 10 ;R 6 and R 14 ; or R 7 and R 15 It is more preferred that W is a combination of:

[0048] In the above formula (1), R other than the substituent W 1 ~R 16 are each independently any one of the following atoms or groups (a1) to (a10): (a1) a hydrogen or deuterium atom; (a2) a halogen atom; (a3) a cyano group; (a4) a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms; (a5) a substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms; (a6) a substituted or unsubstituted arylamino group having 6 to 20 carbon atoms; (a7) a substituted or unsubstituted triarylsilyl group, an alkyldiarylsilyl group, a dialkylarylsilyl group, or a trialkylsilyl group (wherein the aryl group is an aryl group having from 6 to 20 carbon atoms; and the alkyl group is an alkyl group having from 1 to 20 carbon atoms); (a8) a substituted or unsubstituted aromatic hydrocarbon group having 6 to 30 carbon atoms; (a9) a substituted or unsubstituted heterocyclic group having 3 to 30 ring atoms; and (a10)R 1 ~R 16 A substituted or unsubstituted saturated hydrocarbon group or saturated heterocyclic group having 5 to 9 ring atoms formed by bonding two adjacent groups among the above.

[0049] In the above formula (1), among the atoms or groups of the above (a1) to (a10), the above atoms or groups of the (a1), (a4), (a7), (a8), and (a10) are preferred, and the atoms or groups of the (a1), (a4), and (a10) are more preferred.

[0050] In the above formula (1), when the groups (a3) ​​to (a10) are substituted groups, the substituents substituting these groups are not particularly limited. However, in the above formula (1), the substituents substituting the groups (a3) ​​to (a10) are each independently at least one substituent selected from the group consisting of a halogen atom, a cyano group, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted haloalkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms, a substituted or unsubstituted alkylamino group having 1 to 20 carbon atoms, a substituted or unsubstituted arylamino group having 6 to 20 carbon atoms, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 30 carbon atoms, and a substituted or unsubstituted heterocyclic group having 3 to 30 ring atoms.

[0051] In the case of the hydrogen atom (H) in (a1) above, the benzene ring is unsubstituted. In addition, the deuterium atom in (a1) is one of the stable isotopes of hydrogen whose nucleus consists of one proton and one neutron. A deuterium atom is 2 It is written as H or D (the first letter of deuterium).

[0052] The halogen atom of (a2) is not particularly limited, and examples thereof include a fluorine atom (F), a chlorine atom (Cl), a bromine atom (Br), an iodine atom (I), etc. Among these, a fluorine atom is preferred from the viewpoint of luminous efficiency.

[0053] The cyano group in (a3) ​​above is represented as CN.

[0054] The alkyl group having 1 to 20 carbon atoms in the above (a4) is not particularly limited, and may be linear, branched, or cyclic. Among these, from the viewpoint of color purity of light emission, branched is preferable. From the viewpoint of solubility and color purity of light emission, the number of carbon atoms in the alkyl group is preferably 2 or more, more preferably 3 or more, and even more preferably 4 or more. From the viewpoint of luminous efficiency, the number of carbon atoms in the alkyl group is preferably 10 or less, more preferably 8 or less, and even more preferably 6 or less. From these viewpoints, the number of carbon atoms in the alkyl group is particularly preferably 4. Specific examples of the alkyl group include, but are not limited to, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an s-butyl group (sec-butyl group), a t-butyl group (tert-butyl group), an i-butyl group, a 2-ethylbutyl group, a 3,3-dimethylbutyl group, an n-pentyl group, an i-pentyl group, a neopentyl group, a t-pentyl group, a cyclopentyl group, a 1-methylpentyl group, a 3-methylpentyl group, a 2-ethylpentyl group, a 4-methyl-2-pentyl group, an n-hexyl group, a 1-methylhexyl group, a 2-ethylhexyl group, a 2-butylhexyl group, a cyclohexyl group, a 4-methylcyclohexyl group, a 4-t-butylcyclohexyl group, an n-heptyl group, a 1-methylheptyl group, a 2,2-dimethylheptyl group, a 2-ethyl ... ethylheptyl, 2-butylheptyl, n-octyl, t-octyl, 2-ethyloctyl, 2-butyloctyl, 2-hexyloctyl, 3,7-dimethyloctyl, cyclooctyl, n-nonyl, n-decyl, adamantyl, 2-ethyldecyl, 2-butyldecyl, 2-hexyldecyl, 2-octyldecyl, n-undecyl Examples of the alkyl group include a 2-methyl-2-phenylene group, an n-dodecyl group, a 2-ethyldodecyl group, a 2-butyldodecyl group, a 2-hexyldodecyl group, a 2-octyldecyl group, a n-tridecyl group, a n-tetradecyl group, a n-pentadecyl group, a n-hexadecyl group, a 2-ethylhexadecyl group, a 2-butylhexadecyl group, a n-heptadecyl group, a n-octadecyl group, a n-nonadecyl group, and a n-icosyl group. Among these, a branched alkyl group is preferable, an isopropyl group or a tert-butyl group is more preferable, and a tert-butyl group is even more preferable.

[0055] The term "substituted alkyl group having 1 to 20 carbon atoms" refers to a group in which an unsubstituted alkyl group having 1 to 20 carbon atoms is substituted with a substituent. Therefore, the number of carbon atoms in the substituted alkyl group may be more than 20.

[0056] The alkoxy group having 1 to 20 carbon atoms in the above (a5) is not particularly limited, and the alkoxy group may be linear, branched, or cyclic. Among these, linear is preferable from the viewpoint of luminous efficiency. The number of carbon atoms in the alkoxy group is preferably 1 to 10 from the viewpoint of luminous efficiency. From the same viewpoint, the number of carbon atoms in the alkoxy group is more preferably 1 to 8, further preferably 1 to 6, and particularly preferably 1. The alkyl group constituting the alkoxy group is not particularly limited, but includes, for example, those described in the above description of the alkyl group. Specific examples of the alkoxy group are not particularly limited, but include, 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. Among these, a methoxy group is preferable.

[0057] The term "substituted alkoxy group having 1 to 20 carbon atoms" refers to an unsubstituted alkoxy group having 1 to 20 carbon atoms substituted with a substituent. Therefore, the number of carbon atoms in the substituted alkoxy group may be more than 20.

[0058] The nitrogen atom of the arylamino group having 6 to 20 carbon atoms in the above (a6) is bonded to a ring-forming carbon atom of a benzene ring (four benzene rings other than the central benzene ring) located on the outer side of the compound of the above formula (1) by a single bond. In this specification, even if a group contains a nitrogen atom, if the nitrogen atom is a ring-forming atom of a heterocycle, the group is treated as a heterocyclic group described later, rather than an arylamino group. The aryl group constituting the arylamino group is not particularly limited, but may be, for example, an aromatic hydrocarbon group having 6 to 20 carbon atoms in the below-mentioned (a8). The arylamino group is not particularly limited, and may be a monoarylamino group or a diarylamino group. Specific examples of the arylamino group are not particularly limited, but may be an N-phenylamino group, an N-biphenylamino group, an N-terphenylamino group, an N,N-diphenylamino group, and an N-biphenyl-N-phenylamino group.

[0059] The term "substituted arylamino group having 6 to 20 carbon atoms" refers to a group in which an unsubstituted arylamino group having 6 to 20 carbon atoms is substituted with a substituent. Therefore, the number of carbon atoms in the substituted arylamino group may be more than 20.

[0060] The silicon (Si) group of the triarylsilyl group, alkyldiarylsilyl group, dialkylarylsilyl group, or trialkylsilyl group in (a7) above is bonded to the ring-forming carbon atom of the benzene ring (four benzene rings other than the central benzene ring) located on the outer side of the compound of formula (1) above by a single bond. The aryl group constituting the triarylsilyl group, alkyldiarylsilyl group, and dialkylarylsilyl group is an aryl group having 6 to 20 carbon atoms, and examples of the aromatic hydrocarbon groups described below having 6 to 20 carbon atoms are given below. The alkyl group constituting the alkyldiarylsilyl group, dialkylarylsilyl group, and trialkylsilyl group is an alkyl group having 1 to 20 carbon atoms, and the groups exemplified as the alkyl group having 1 to 20 carbon atoms in (a4) above can be applied in the same manner. Specific examples of the triarylsilyl group are not particularly limited, and examples thereof include a triphenylsilyl group, a tri(tert-butylphenyl)silyl group, and a di-tert-butylphenyl(phenyl)silyl group. Specific examples of alkyldiarylsilyl groups include, but are not limited to, diphenylmethylsilyl groups, diphenyl(tert-butyl)silyl groups, di-tert-butylphenyl(methyl)silyl groups, di-tert-butylphenyl(tert-butyl)silyl groups, etc. Specific examples of dialkylarylsilyl groups include, but are not limited to, dimethylphenylsilyl groups, etc. Specific examples of trialkylsilyl groups include, but are not limited to, trimethylsilyl groups, tri-tert-butylsilyl groups, di-tert-butyl(methyl)silyl groups, etc.

[0061] The term "substituted triarylsilyl group, alkyldiarylsilyl group, dialkylarylsilyl group, or trialkylsilyl group" refers to a group in which an unsubstituted aryl group having from 6 to 20 carbon atoms and an alkyl group having from 1 to 20 carbon atoms are substituted with a substituent. Thus, the number of carbon atoms in the aryl group of the substituted triarylsilyl group, alkyldiarylsilyl group, and dialkylarylsilyl group may be more than 20, and the number of carbon atoms in the alkyl group of the substituted alkyldiarylsilyl group, dialkylarylsilyl group, and trialkylsilyl group may be more than 20.

[0062] The aromatic hydrocarbon group having 6 to 30 carbon atoms in the above (a8) refers to a group derived from a hydrocarbon ring having one or more aromatic properties. In this specification, a hydrocarbon ring having aromatic properties refers to a hydrocarbon ring having aromatic properties in part or as a whole.

[0063] When the aromatic hydrocarbon group contains two or more aromatic hydrocarbon rings, these rings may be bonded to each other by a single bond or condensed. When the aromatic hydrocarbon group contains two or more aromatic hydrocarbon rings, one atom may also serve as a ring-forming atom of any of these rings.

[0064] The aromatic hydrocarbon group preferably has 6 or more and 20 or less, more preferably 6 or more and 12 or less, and further preferably 6, from the viewpoint of the color purity of the emitted light.

[0065] Specific examples of aromatic hydrocarbon groups include, but are not limited to, phenyl, mesityl, tert-butylphenyl, bis(tert-butyl)phenyl, biphenyl, terphenyl, naphthyl, fluorenyl, anthracenyl, terphenyl, quaterphenyl, quinquephenyl, sexiphenyl, triphenylenyl, pyrenyl, benzofluorenyl, chrysenyl, and combinations thereof.

[0066] The term "substituted aromatic hydrocarbon group" refers to an unsubstituted aromatic hydrocarbon group substituted with a substituent. Therefore, when the aromatic hydrocarbon group has a specific upper limit of carbon number, such as 30 or less, the substituted aromatic hydrocarbon group may have a carbon number exceeding the upper limit.

[0067] The heterocyclic group having 3 to 30 ring atoms in the above (a9) refers to a group derived from one or more heterocycles. The heterocyclic group is not particularly limited, and may be an aromatic heterocyclic group or a non-aromatic heterocyclic group. Among these, an aromatic heterocyclic group is preferable from the viewpoint of color purity of light emission.

[0068] The aromatic heterocyclic group refers to a group derived from a heterocycle having one or more aromatic rings. In this specification, the aromatic heterocycle refers to a heterocycle having aromaticity in part or as a whole. When a part of the aromatic heterocycle has aromaticity, the aromaticity may be derived from the heterocyclic part in the ring, or may be derived from the hydrocarbon ring part in the ring. The aromatic heterocycle is not particularly limited, and examples thereof include rings 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). In addition, when the carbon atoms constituting the ring structure form a ketone group (C=O group), a thioketone group (C=S group), or a C=NH group, or when the sulfur atoms constituting the ring structure form a sulfinyl group (S=O group) or a sulfonyl group (S(=O)=O group), the atoms constituting the ring structure may be bonded to an atom outside the ring through a double bond. In this case, in the present specification, the exocyclic atom forming a double bond with an atom constituting a ring structure is considered to be a part of the aromatic heterocycle. In addition, when the exocyclic atom forming the double bond is bonded to a hydrogen atom via a single bond, the hydrogen atom is also considered to be a part of the aromatic heterocycle.Specific examples of the heterocycle having aromaticity include, but are not limited to, 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, and an imidazole. ring, benzimidazole ring, pyrazole ring, indazole ring, oxazole ring, isoxazole ring, benzoxazole ring, benzisoxazole ring, thiazole ring, isothiazole ring, benzothiazole ring, benzisothiazole ring, imidazolinone ring, benzimidazolinone ring, imidazopyridine ring, imidazopyrimidine ring, imidazophenanthridine ring, benzimidazophenanthridine ring, azadibenzofuran ring, azacarbazole ring, azadibenzothiophene ring, diazadibenzofuran ring, diazacarbazole ring, diazadibenzothiophene ring, xanthone ring, thioxanthone ring, and the like.

[0069] When the aromatic heterocyclic group contains two or more aromatic heterocyclic rings, these rings may be bonded to each other by a single bond or condensed. When the aromatic heterocyclic group contains two or more aromatic heterocyclic rings, one atom may also serve as a ring-forming atom of any of these rings.

[0070] The number of ring-forming atoms (the total number of ring-forming carbon atoms and ring-forming heteroatoms) of the aromatic heterocyclic group is 3 or more and 30 or less, and from the viewpoint of the peak wavelength of the emission spectrum and the color purity of the emission, it is preferably 5 or more and 20 or less, and more preferably 6 or more and 14 or less. The number of ring-forming heteroatoms of the aromatic heterocyclic group is not particularly limited, but from the viewpoint of the peak wavelength of the emission spectrum and the color purity of the emission, it is preferably 1 or more and 10 or less. From the same viewpoint, the number of ring-forming heteroatoms of the aromatic heterocyclic group is more preferably 1 or more and 5 or less, and even more preferably 1 or more and 3 or less. As mentioned above, the ring-forming atoms refer to atoms that directly form a ring structure.

[0071] Specific examples of the aromatic heterocyclic group include, but are not limited to, a thienyl group, a furanyl group, a pyrrolyl group, an imidazolyl group, a thiazolyl group, an oxazolyl group, an oxadiazolyl group, a triazolyl group, a pyridyl group, a bipyridyl group, a pyrimidyl group, a triazinyl group, an acridinyl group, a pyridazinyl group, a pyrazinyl 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 isopropyl group, a phenyl ... Examples of such groups include isoquinolinyl group, indolyl group, carbazolyl group, benzoxazolyl group, benzimidazolyl group, benzothiazolyl group, benzocarbazolyl group, benzothiophenyl group, dibenzothiophenyl group, thienothienyl group, benzofuranyl group, phenanthrolinyl group, thiazolyl group, isoxazolyl group, oxadiazolyl group, thiadiazolyl group, phenothiazinyl group, dibenzosilolyl group, dibenzofuranyl group, xanthonyl group, etc. Among these, triazinyl group, carbazolyl group, benzoxazolyl group, and xanthonyl group are preferred.

[0072] In addition, the non-aromatic heterocyclic group refers to a group derived from one or more non-aromatic heterocycles. In this specification, the non-aromatic heterocycle refers to a heterocycle that does not have aromaticity either in part or as a whole. The non-aromatic heterocycle is not particularly limited, but examples thereof include rings 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). As the heteroatom, a nitrogen atom (N) or an oxygen atom (O) is preferable from the viewpoint of the peak wavelength of the emission spectrum and the color purity of the emission. Note that, in some cases, the atoms constituting the ring structure are bonded to atoms outside the ring via a double bond, such as when the carbon atoms constituting the ring structure form a ketone group (C=O group), a thioketone group (C=S group), or a C=NH group, or when the sulfur atoms constituting the ring structure form a sulfinyl group (S=O group) or a sulfonyl group (S(=O)=O group). In this case, in the present specification, the atom outside the ring that forms a double bond with the atom that forms the ring structure is considered to be a part of the non-aromatic heterocycle. In addition, when the atom outside the ring that forms the double bond is bonded to a hydrogen atom via a single bond, the hydrogen atom is also considered to be a part of the non-aromatic heterocycle. Specific examples of the non-aromatic heterocycle include, but are not limited to, a pyrrolidine ring, a tetrahydrofuran ring, a tetrahydrothiophene ring, a piperidine ring, a tetrahydropyran ring, a tetrahydrothiopyran ring, a dioxane ring, a morpholine ring, and a dioxolane ring.

[0073] When a non-aromatic heterocyclic group contains two or more non-aromatic heterocyclic rings, these rings may be bonded to each other by a single bond or condensed. When a non-aromatic heterocyclic group contains two or more non-aromatic heterocyclic rings, one atom may also serve as a ring-forming atom of any of these rings.

[0074] The number of ring-forming atoms (the total number of ring-forming carbon atoms and ring-forming heteroatoms) of the non-aromatic heterocyclic group is 3 or more and 30 or less, and from the viewpoint of the peak wavelength of the emission spectrum and the color purity of the emission, it is preferably 5 or more and 20 or less, and more preferably 6 or more and 14 or less. The number of ring-forming heteroatoms of the non-aromatic heterocyclic group is not particularly limited, but from the viewpoint of the peak wavelength of the emission spectrum and the color purity of the emission, it is preferably 1 or more and 10 or less. In addition, from the same viewpoint, the number of ring-forming heteroatoms of the non-aromatic heterocyclic group is more preferably 1 or more and 5 or less, and even more preferably 1 or more and 3 or less. As mentioned above, the ring-forming atom refers to an atom that directly forms a ring structure. Thus, when there is an atom outside the ring that forms a double bond with an atom that forms a ring structure, the atom is not included in the ring-forming atoms.

[0075] Specific examples of non-aromatic heterocyclic groups include, but are not limited to, a pyrrolidinyl group, a tetrahydrofuranyl group, a tetrahydrothienyl group, a piperidinyl group, a tetrahydropyranyl group, a tetrahydrothiopyranyl group, a dioxanyl group, a morpholinyl group, and a dioxolanyl group.

[0076] The term "substituted heterocyclic group" refers to a group in which an unsubstituted heterocyclic group is substituted with a substituent. Therefore, when the heterocyclic group has a specific upper limit on the number of ring atoms, such as 30 or less, and the substituent forms a ring structure, the number of ring atoms in the substituted heterocyclic group may exceed the upper limit.

[0077] R in (a10) above 1 ~R 16 The substituted or unsubstituted saturated hydrocarbon group or saturated heterocyclic group having 5 to 9 ring atoms formed by bonding two adjacent groups to each other is R bonded to the ring carbon atom of the benzene ring (four benzene rings other than the central benzene ring) located on the outer side of the compound of the above formula (1). 1 ~R 16 Two adjacent groups (e.g., R 1 and R 2 ;R2 and R 3 ; or R 3 and R 4 ) are bonded to the ring-forming carbon atoms of the benzene ring by single bonds and to each other by single bonds. That is, the group (a10) is R 1 ~R 16 Two adjacent groups among R are bonded to each other to form a saturated hydrocarbon group or saturated heterocyclic group having 5 to 9 ring atoms condensed with a benzene ring. 1 ~R 16 The positions of the fused ring formed by two adjacent groups (the fused positions on the benzene ring) are preferably the 2-position and the 3-position on the benzene ring. 2 and R 3; R 6 and R 7 ;R 10 and R 11 ; or R 14 and R 15 are preferably bonded together to form a saturated hydrocarbon group or a saturated heterocyclic group having 5 to 9 ring atoms. 2 and R 3; And R 10 and R 11 are bonded to each other to form a saturated hydrocarbon group or a saturated heterocyclic group having 5 to 9 ring atoms, or R 6 and R 7 ; and R 14 and R 15 More preferably, R 1 and R 2 are bonded to each other to form a saturated hydrocarbon group or a saturated heterocyclic group having 5 to 9 ring atoms. 1 ~R 16 When a condensed ring with a benzene ring is formed by the formula (I), it is preferable that the condensed ring has two condensed rings.

[0078] Examples of the fused ring (saturated hydrocarbon ring) formed by a saturated hydrocarbon group having 5 to 9 ring atoms include a cyclopentane ring, a cyclohexane ring, a cycloheptane ring, a cyclooctane ring, and a cyclononane ring. Examples of the fused ring (saturated heterocycle) formed by a saturated heterocyclic group having 5 to 9 ring atoms include the above-mentioned non-aromatic heterocyclic groups having 5 to 9 ring atoms. Specific examples of the fused ring (saturated heterocycle) formed by a saturated heterocyclic group having 5 to 9 ring atoms include a pyrrolidine ring, a tetrahydrofuran ring, a tetrahydrothiophene ring, a piperidine ring, a tetrahydropyran ring, a tetrahydrothiopyran ring, a dioxane ring, a morpholine ring, and a dioxolane ring.

[0079] The term "substituted saturated hydrocarbon group or saturated heterocyclic group having 5 to 9 ring atoms" refers to a group in which an unsubstituted saturated hydrocarbon group or saturated heterocyclic group is substituted with a substituent. Therefore, when a saturated hydrocarbon group or saturated heterocyclic group has a specific upper limit on the number of ring atoms, such as 9 or less ring atoms, and the substituent forms a ring structure, the number of ring atoms of the substituted saturated hydrocarbon group or saturated heterocyclic group may exceed the upper limit.

[0080] The substituents substituting the groups in (a4) to (a10) above, namely, a halogen atom, a cyano group, an unsubstituted alkyl group having from 1 to 20 carbon atoms, an unsubstituted alkoxy group having from 1 to 20 carbon atoms, an unsubstituted arylamino group having from 6 to 20 carbon atoms, an unsubstituted aromatic hydrocarbon group having from 6 to 30 carbon atoms, and an unsubstituted heterocyclic group having from 3 to 30 ring atoms, are each the same as the unsubstituted groups in the description of (a2) to (a10) above.

[0081] The unsubstituted haloalkyl group having 1 to 20 carbon atoms, which is a substituent substituting the groups (a4) to (a10), includes the alkyl group described in (a4) above, in which at least one hydrogen atom is substituted with a halogen atom described in (a2) above. From the viewpoint of luminous efficiency, the halogen atom is preferably a fluorine atom. Specific examples of the haloalkyl group include a trifluoromethyl group, a trichloromethyl group, a tribromomethyl group, and a triiodomethyl group. Among these, a fluorinated alkyl group is preferable, and a trifluoromethyl group is more preferable.

[0082] In the unsubstituted alkylamino group having 1 to 20 carbon atoms, which is a substituent substituting the groups (a4) to (a10) above, any atom constituting the unsubstituted groups (a4) to (a10) above is bonded to the nitrogen atom thereof by a single bond in the above formula (1). The alkyl group constituting the alkylamino group is not particularly limited, but is, for example, the same as the explanation of (a3) ​​above. The alkylamino group is not particularly limited, and may be a monoalkylamino group or a dialkylamino group. Specific examples of alkylamino groups include, but are not limited to, an N-methylamino group, an N-ethylamino group, an N-propylamino group, an N-isopropylamino group, an N-butylamino group, an N-isobutylamino group, an N-sec-butylamino group, an N-tert-butylamino group, an N-pentylamino group, an N-hexylamino group, an N,N,N-dimethylamino group, an N-methyl-N-ethylamino group, an N,N-diethylamino group, an N,N-dipropylamino group, an N,N-diisopropylamino group, an N,N-dibutylamino group, an N,N-diisobutylamino group, an N,N-dipentylamino group, and an N,N-dihexylamino group.

[0083] Here, preferred substituents for substituting the groups (a4) to (a10) above are halogen atoms, cyano groups, unsubstituted alkyl groups having 1 to 20 carbon atoms, unsubstituted alkoxy groups having 1 to 20 carbon atoms, and unsubstituted arylamino groups having 6 to 20 carbon atoms. Among these, halogen atoms and unsubstituted alkyl groups having 1 to 20 carbon atoms are more preferred, and fluorine atoms and unsubstituted linear or branched alkyl groups having 1 to 20 carbon atoms are even more preferred. And fluorine atoms, methyl groups, ethyl groups, isopropyl groups, and tert-butyl groups are particularly preferred.

[0084] In one embodiment, preferred substituents for substituting the groups (a4) to (a10) are unsubstituted aromatic hydrocarbon groups having a carbon number of 6 to 30. Among these, groups derived from a benzene ring are preferred.

[0085] In one embodiment, preferred substituents for substituting the groups (a4) to (a10) are unsubstituted heterocyclic groups having 3 to 30 ring atoms. Among these, heterocyclic groups containing oxygen or nitrogen atoms as heteroatoms are preferred, and dibenzofuranyl, carbazolyl, and benzoxazolyl groups are more preferred. Furthermore, dibenzofuranyl and carbazolyl groups are even more preferred.

[0086] Preferred substituents for substituting the group (a4) above are halogen atoms and unsubstituted alkyl groups having 1 to 20 carbon atoms. Therefore, the substituents of the "substituted alkyl group having 1 to 20 carbon atoms" are preferably halogen atoms and unsubstituted alkyl groups having 1 to 20 carbon atoms. Among these, unsubstituted linear or branched alkyl groups having 1 to 20 carbon atoms are more preferred. Furthermore, a methyl group, an ethyl group, an isopropyl group, and a t-butyl group are even more preferred.

[0087] Preferred substituents for substituting the group (a7) above are halogen atoms and unsubstituted alkyl groups having 1 to 20 carbon atoms. Therefore, the substituents for the "substituted triarylsilyl group, alkyldiarylsilyl group, dialkylarylsilyl group, or trialkylsilyl group" are preferably halogen atoms and unsubstituted alkyl groups having 1 to 20 carbon atoms. Among these, unsubstituted linear or branched alkyl groups having 1 to 20 carbon atoms are more preferred. Furthermore, methyl groups, ethyl groups, isopropyl groups, and t-butyl groups are even more preferred.

[0088] Preferred substituents for the group (a10) are halogen atoms and unsubstituted alkyl groups having 1 to 20 carbon atoms. 1 ~R 16 Among these, the substituent of the "substituted saturated hydrocarbon group or saturated heterocyclic group having 5 to 9 ring atoms formed by bonding two adjacent groups to each other" is preferably a halogen atom or an unsubstituted alkyl group having 1 to 20 carbon atoms. Among these, an unsubstituted linear or branched alkyl group having 1 to 20 carbon atoms is more preferable. Furthermore, a methyl group, an ethyl group, an isopropyl group, and a t-butyl group are further preferable.

[0089] When the groups (a4) to (a10) are substituted groups, the substituent may be a group substituted with a further substituent. The further substituent is not particularly limited, and examples thereof include those exemplified as the substituents when the groups (a4) to (a10) are substituted groups, and groups in which these groups are further substituted with these groups.

[0090] In one embodiment, in the compound of formula (1), R 1 ~R 16 It is preferable that R contains at least one group selected from the following group (X) as a group other than the substituent W. That is, in a preferred embodiment of the present invention, in the compound of formula (1), 1 ~R 16 At least one (preferably two or more) of R 1 ~R16 At least one (preferably two or more) of R 1 ~R 4 At least one of and R 9 ~R 12 At least one of R is a substituent W; 5 ~R 8 At least one of and R 13 ~R 16 At least one of the above is a group selected from the following group (X):

[0091] [ka]

[0092] In the above substituents, the substituent having two bonding positions (*) to the benzene ring is R 1 ~R 16 and bonded to adjacent two positions of the benzene ring to form a fused ring. For example, the following group (a-1) is fused with a benzene ring to form a five-membered ring (a-2), and the following group (b-1) is fused with a benzene ring to form a six-membered ring (b-2).

[0093] [ka]

[0094] Also, in one embodiment, in the compound of formula (1), R 1 ~R 16 It is preferable that R contains at least one group selected from the following group (Y) as a group other than the substituent W. That is, in a preferred embodiment of the present invention, in the compound of formula (1), 1 ~R 16 At least one (preferably two or more) of R 1 ~R 16 At least one (preferably two or more) of R 1 ~R 4At least one of and R 9 ~R 12 At least one of R is a substituent W; 5 ~R 8 At least one of and R 13 ~R 16 At least one of the above is a group selected from the following group (Y):

[0095] [ka]

[0096] Specific examples of the compound of formula (1) according to one embodiment of the present invention are given below. However, the present invention is not limited to these specific examples. For example, the compound of formula (1) according to one embodiment of the present invention includes the following compounds (100) to (117).

[0097] [ka]

[0098] [ka]

[0099] Preferred compounds include, for example, compounds 101, 102, 105, 108, 110, 111, 113, and the like.

[0100] The compound of formula (1) according to the present invention can realize emission with a peak wavelength of the emission spectrum in the blue wavelength region and high color purity. In the present specification, the blue wavelength region refers to a wavelength range of 380 nm to 500 nm. The peak wavelength of emission in the photoluminescence (PL) of the compound of formula (1) according to the present invention is not particularly limited, but is preferably in the range of 440 nm to 480 nm. In addition, the peak wavelength is more preferably in the wavelength range of 445 nm to 470 nm, more preferably in the range of 450 nm to 470 nm, and particularly preferably in the range of 450 nm to 465 nm. When the peak wavelength is in the above range, good emission, especially good blue emission, can be obtained. The preferred range of the full width at half maximum (FWHM) of the peak of the emission spectrum in photoluminescence (PL) is preferably 30 nm or less, more preferably 20 nm or less, and even more preferably 15 nm or less (lower limit: more than 0 nm). The peak wavelength of PL emission and the full width at half maximum (FWHM) of the peak of the emission spectrum in PL can be measured using a spectrofluorometer F-7000 manufactured by Hitachi High-Tech Corporation. More specifically, when the compound of formula (1) according to the present invention is 1×10 -5 M (=mol / dm 3 The fluorescence intensity can be evaluated by measuring a toluene solution (100 mol / L) of the compound of formula (1) according to the present invention and a host molecule by vapor deposition using a method described in the Examples below, at room temperature with the spectrofluorometer at an excitation wavelength of 360 nm.

[0101] The narrow FWHM and FWQM, TADF characteristics, and emission wavelength required for molecules used as dopants can be predicted using quantum chemical calculations.

[0102] The synthesis method of the compound of formula (1) according to the present invention is not particularly limited, and can be synthesized based on the knowledge of known synthesis methods. More specifically, it can be synthesized according to the method described in the examples or the method described in the examples. For example, it can be synthesized by changing the raw materials, reaction conditions, etc., adding or removing some steps, or appropriately combining known synthesis methods in the methods described in the examples.

[0103] The method for confirming the structure of the compound of formula (1) according to the present invention is not particularly limited. The structure of the compound of formula (1) according to the present invention can be confirmed by, for example, a known method (e.g., NMR, LC-MS, etc.).

[0104] <Materials for organic electroluminescence devices> Another aspect of the present invention relates to a material for an organic electroluminescence device, comprising the compound of the above formula (1). The material is more preferably a material for an emission layer.

[0105] The organic electroluminescence device material according to one embodiment of the present invention preferably contains the compound of formula (1) and other materials used in the organic electroluminescence device. The other materials used in the organic electroluminescence device are not particularly limited, but are preferably a phosphorescent compound or a host material. Also, it is more preferable that the compound of formula (1) is used as a dopant material, and the phosphorescent complex is used as an auxiliary dopant material. By using the compound of formula (1) and the phosphorescent complex or the host material (preferably the phosphorescent complex and the host material) together, the luminous efficiency is significantly improved. The reason for this is presumed to be as follows. When the material for the organic electroluminescence device contains a host material, the phosphorescent complex receives energy from the host material. Then, the phosphorescent complex transfers energy to the compound of formula (1) by a FRET mechanism (Fluorescence Resonance Energy Transfer). As a result, highly efficient energy transfer occurs from the phosphorescent complex to the compound of formula (1). In addition, other materials used in the organic electroluminescence device may be other materials known in the art.

[0106] The content of the compound of the above formula (1) relative to the total mass of the material for organic electroluminescence device (particularly, the material for 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. In this range, an organic electroluminescence device with excellent color purity of light emission and high light-emitting efficiency can be obtained. The content of the compound of the above formula (1) relative to the total mass of the material for organic electroluminescence device (particularly, the material for the light-emitting layer) is not particularly limited, but 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. In this range, an organic electroluminescence device with excellent color purity of light emission and high light-emitting efficiency can be obtained. The preferred content of the compound of the above formula (1) relative to the total mass of the light-emitting layer in the light-emitting layer of the organic electroluminescence device described later is also the same as above.

[0107] (Phosphorescent complex) The organic electroluminescence device material according to one embodiment of the present invention preferably further contains a phosphorescent complex in addition to the compound of formula (1). By containing the phosphorescent complex, the luminous efficiency is significantly improved. By using the compound of formula (1) together with the phosphorescent complex, the luminous efficiency is significantly improved. The reason for this is presumed to be as follows. The phosphorescent complex transfers energy to the compound of formula (1) by a FRET mechanism (Fluorescence Resonance Energy Transfer). As a result, highly efficient energy transfer occurs from the phosphorescent complex to the nitrogen-containing condensed ring compound. It is presumed that the above effect is achieved because highly efficient energy transfer is possible from the phosphorescent complex to the compound of formula (1).

[0108] The phosphorescent complex is not particularly limited, but is preferably a metal complex from the viewpoint of luminous efficiency. From the same viewpoint, it is more preferably a platinum complex or a palladium complex, and is even more preferably a platinum complex. Therefore, in the material for organic electroluminescence device according to a preferred embodiment of the present invention, for example, the phosphorescent complex is a platinum complex.

[0109] The phosphorescent complex is not particularly limited, but from the viewpoints of color purity and luminous efficiency of emitted light, a preferred example is a compound having a structure of the following formula (4).

[0110] [ka]

[0111] In the above formula (4), M is a metal ion having a coordination number of 4, R 41 , R 42 , R 43 , and R 44 are each independently a substituted or unsubstituted hydrocarbon ring group, or a substituted or unsubstituted heterocyclic group; L 41 is R 41 and R 42 is a linking group connecting L 42 is R 42 and R 43 is a linking group connecting L 43 is R 43 and R 44 is a linking group that links

[0112] In the above formula (4), the hydrocarbon ring group represents a group derived from one or more hydrocarbon rings. When the hydrocarbon ring group contains two or more hydrocarbon rings, some or all of these rings may be bonded to each other by single bonds or condensed. When the hydrocarbon ring group contains two or more hydrocarbon rings, one atom may also serve as a ring-forming atom of any of these rings.

[0113] In the above formula (4), the heterocyclic group is the same as the monovalent heterocyclic group described in the description of the above group (a9) in the above formula (1), except that the valence may be different.

[0114] The substituent substituting the hydrocarbon ring group or the heterocyclic group in the above formula (4) is not particularly limited, but is preferably one of the substituents exemplified as the substituents substituting the above groups (a4) to (a10) in the above formula (1).

[0115] In the above formula (4), M is a platinum (Pt) ion or a palladium (Pd) ion. It is preferable that the ion is a platinum (Pt) ion.

[0116] As the phosphorescent complex, a known compound may be used. For example, see "Tyler Fleetham et al., "Efficient "Pure" Blue OLEDs Employing Tetradentate Pt Complexes with The platinum complexes described in "A Narrow Spectral Bandwidth", Advanced Materials, 2014, 26, 7116-7121", the platinum complexes described in European Patent Application Publication No. 3670520, the platinum complexes and palladium complexes described in JP-A-2019-029500, and the platinum complexes described in U.S. Patent Application Publication No. 2015 / 0162552 may also be used.

[0117] Specific examples of phosphorescent complexes according to one embodiment of the present invention are given below, however, the present invention is not limited to these specific examples.

[0118] [ka]

[0119] [ka]

[0120]

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[0121]

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[0123]

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[0125]

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[0128] The content of the phosphorescent complex relative to the total mass of the material for organic electroluminescence device (particularly, the material for the light-emitting layer) is not particularly limited, but is preferably 0.1% by mass or more, more preferably 0.2% by mass or more. The content is more preferably 0.5% by mass or more, and even more preferably 1% by mass or more. The content is particularly preferably 3% by mass or more, and even more preferably 5% by mass or more. In this range, an organic electroluminescence device having excellent color purity of light emission and high light-emitting efficiency can be obtained. In addition, the content of the phosphorescent complex relative to the total mass of the material for organic electroluminescence device (particularly, the material for the light-emitting layer) is not particularly limited, but is preferably 50% by mass or less. The content is more preferably 40% by mass or less, and even more preferably 30% by mass or less. In this range, an organic electroluminescence device having excellent color purity of light emission and high light-emitting efficiency can be obtained. The preferred content of the phosphorescent complex relative to the total mass of the light-emitting layer in the light-emitting layer of the organic electroluminescence device described later is the same as above.

[0129] When the material for organic electroluminescence device (particularly, the material for the light-emitting layer) contains a phosphorescent complex, the content is preferably 100 parts by mass or more relative to 100 parts by mass of the compound of the above formula (1). 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 compound of the above formula (1). In this range, an organic electroluminescence device having excellent color purity of light emission and high light-emitting efficiency can be obtained. In addition, the content of the phosphorescent complex is not particularly limited, but is preferably 10,000 parts by mass or less relative to 100 parts by mass of the compound of the above formula (1). 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 compound of the above formula (1). In this range, an organic electroluminescence device having excellent color purity of light emission and high light-emitting efficiency can be obtained. The preferred content (parts by mass) of the phosphorescent complex relative to 100 parts by mass of the compound of the above formula (1) in the light-emitting layer of the organic electroluminescence device described later is also the same as above.

[0130] (Host material) The material for an organic electroluminescence device according to one embodiment of the present invention preferably further comprises a host material in addition to the compound of formula (1) above. By using the compound of formula (1) above as a dopant material in combination with the host material, excellent luminous efficiency can be achieved in an organic electroluminescence device.

[0131] The host material is not particularly limited and can be a known host material. For example, the known host material can be an anthracene derivative, a pyrene derivative, a fluoranthene derivative, a chrysene derivative, a dihydrobenzoanthracene derivative, or a triphenylene derivative. As the anthracene derivative, 9-(1-naphthyl)-10-(2-naphthyl)anthracene (compound HT4 shown below) is preferably used.

[0132] [ka]

[0133] Preferred examples of the host material include compounds having a carbazole ring structure (excluding the compounds represented by the above general formula (1)), compounds having a ring structure in which one or more ring-forming carbon atoms of the carbazole ring are replaced by nitrogen atoms (excluding the compounds represented by the above general formula (1) and the compounds having the above carbazole ring structure), and compounds having a triazine ring structure (excluding the compounds represented by the above general formula (1), the compounds having the above carbazole ring structure, and the compounds having a ring structure in which one or more ring-forming carbon atoms of the carbazole ring are replaced by nitrogen atoms). Among these, compounds having a carbazole ring structure are more preferred. By using these compounds as the host material, efficient energy transfer in the light-emitting layer can be promoted. In addition, the balance of carrier mobility between electrons and holes can be further improved. In the carbazole ring structure, the ring structure in which one or more ring-forming carbon atoms of the carbazole ring are replaced by nitrogen atoms, and the triazine ring structure in these compounds, hydrogen atoms bonded to the ring-forming atoms constituting these rings may be replaced by other atoms or substituents. In addition, two or more of these substituents may form a ring structure.

[0134] The compound having the above-mentioned carbazole ring structure or the compound having a ring structure in which one or more of the ring-forming carbon atoms of the above-mentioned carbazole ring are substituted with a nitrogen atom is not particularly limited, but a compound having a structure represented by the following formula (5) is preferable.

[0135] [ka]

[0136] In the above formula (5), Z 51 , CH, CR 51 or N, Z 52 , CH, CR 52 or N, Z 53 , CH, CR 53 or N, Z 54 , CH, CR 54 or N, Z 55 , CH, CR 55 or N, Z 56 , CH, CR 56 or N, Z 57 , CH, CR 57 or N, Z 58 , CH, CR 58 or N, R 51 ~R 58 are each independently any one of the following groups (5a) to (5h), (5a) a cyano group, (5b) a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms; (5c) a substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms, (5d) a substituted or unsubstituted arylamino group having 6 to 20 carbon atoms, (5e) Substituted or unsubstituted phosphoryl groups (-POH 2 basis), (5f) Substituted or unsubstituted silyl groups (-SiH 3 basis), (5g) Substituted or unsubstituted monovalent aromatic hydrocarbon groups, (5h) a substituted or unsubstituted monovalent heterocyclic group, Ar 51 is a group containing at least one of an aromatic hydrocarbon group and a heterocyclic group, m is 1, 2, 3, 4, 5 or 6; Here, the R 51 and the above R 52 , R 52 and the above R 53 , R 53 and the above R 54 , R 55 and the above R56 , R 56 and the above R 57 or the R 57 and the above R 58 may form an aliphatic hydrocarbon ring, an aromatic hydrocarbon ring, or a heterocyclic ring containing the carbon atoms to which they are each attached.

[0137] In the above formula (5), the explanations of the groups (5b) to (5d), (5g) and (5h) are the same as the explanations of the groups (a4) to (a6), (a8) and (a9) in the above formula (1), respectively.

[0138] Also, Ar 51 In the above, the aromatic hydrocarbon group is the same as the monovalent aromatic hydrocarbon group described in the description of the group (a8) in the above formula (1), except that the valence may be different.

[0139] And Ar 51 In the above, the heterocyclic group is the same as the monovalent heterocyclic group described in the description of the group (a9) in the above formula (1), except that the valence may be different.

[0140] In the above formula (5), Z 51 ~Z 58 It is preferable that all of Z are not N or only one is N. 51 ~Z 58 More preferably, n is not all N.

[0141] In the above formula (5), when the groups (5b) to (5h) are substituted groups, the substituents substituting these groups are not particularly limited. For example, they may be the groups (5a) to (5h). Specific examples of the substituents substituting these groups are not particularly limited, but include a cyano group, an unsubstituted alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms substituted with a monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms further substituted with an unsubstituted alkenyl group having 2 to 30 carbon atoms, a substituted or unsubstituted arylamino group having 6 to 20 carbon atoms, an unsubstituted monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms, an alkoxy group having 1 to 20 carbon atoms substituted with a cyano group, and the like. monovalent aromatic hydrocarbon groups having from 6 to 30 carbon atoms and substituted with an unsubstituted alkenyl group having from 2 to 30 carbon atoms; monovalent aromatic hydrocarbon groups having from 6 to 30 carbon atoms and substituted with an unsubstituted arylamino group having from 6 to 20 carbon atoms; unsubstituted monovalent heterocyclic groups having from 3 to 30 ring atoms; and monovalent heterocyclic groups having from 3 to 30 ring atoms and substituted with an unsubstituted monovalent aromatic hydrocarbon group having from 6 to 30 carbon atoms.

[0142] In the above formula (5), Ar 51 is not particularly limited as long as it is at least one of an aromatic hydrocarbon group and a heterocyclic group. For example, it may be a substituted or unsubstituted aromatic hydrocarbon group, a substituted or unsubstituted heterocyclic group, a group in which one or more substituted or unsubstituted aromatic hydrocarbon groups and one or more substituted or unsubstituted heterocyclic groups are bonded via a single bond, or a group in which two or more substituted or unsubstituted aromatic hydrocarbon groups or substituted or unsubstituted heterocyclic groups are bonded via a linking group other than these groups.

[0143] In the group in which two or more substituted or unsubstituted aromatic hydrocarbon groups or substituted or unsubstituted heterocyclic groups are bonded via a linking group other than these groups, the linking group is not particularly limited.Specific examples include a Si group, an N group, a P=O group, an S(=O)=O group, and a C=O group.

[0144] In the above formula (5), Ar 51 When the group constituting the formula is a substituted group, the substituent substituting the group is not particularly limited. For example, it may be the group of the above (5a) to (5h). Specific examples of the substituent substituting the group are not particularly limited, but include a cyano group, an unsubstituted alkyl group having 1 to 20 carbon atoms, and a monovalent heterocyclic group having 3 to 30 ring atoms substituted with an unsubstituted alkyl group having 1 to 20 carbon atoms.

[0145] Here, the substituents of the groups (5b) to (5h) above, or Ar 51 In the substituents of the group constituting the formula (a), the alkyl group having 1 to 20 carbon atoms, the alkoxy group having 1 to 20 carbon atoms, the arylamino group having 6 to 20 carbon atoms, the monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms, and the monovalent heterocyclic group having 3 to 30 ring atoms are the same as those described above for the groups (a4) to (a10) in formula (1).

[0146] In addition, the substituents of the groups (5c) to (5h) above, Ar 51 The alkenyl group having 2 to 30 carbon atoms in the substituent of the group constituting the formula (I) is not particularly limited, and may be linear, branched, or cyclic. Specific examples of the alkenyl group are not particularly limited, and include, for example, vinyl group, 2-propenyl group, 2-butenyl group, 3-butenyl group, 1-methyl-2-propenyl group, 2-methyl-2-propenyl group, 2-pentenyl group, 3-pentenyl group, 4-pentenyl group, 1-methyl-2-butenyl group, 2-methyl-2-butenyl group, 3-methyl-2-butenyl group, 1-methyl-3-butenyl group, 2-methyl-3-butenyl group, 3-methyl-3-butenyl group, 1,1-dimethyl-2-propenyl group, 1,2-dimethyl-2-propenyl group, and 1-ethyl-2-propenyl group.

[0147] m is preferably 1, 2, 3 or 4, and more preferably 2.

[0148] Specific examples of the host material according to one embodiment of the present invention, which are a compound having a carbazole ring structure and a compound having a ring structure in which one or more of the ring-forming carbon atoms of the carbazole ring are substituted with a nitrogen atom, are given below, but the present invention is not limited to these specific examples.

[0149] [ka]

[0150] [ka]

[0151] [ka]

[0152] [ka]

[0153] [ka]

[0154] [ka]

[0155] [ka]

[0156] [ka]

[0157] From these facts, an example of a material for an organic electroluminescence device according to a preferred embodiment of the present invention is a material for an organic electroluminescence device, which includes a compound of the above formula (1), the above phosphorescent complex, and a host material, and the host material includes a compound having a structure represented by the above formula (5). In addition, an example of a preferred embodiment of an organic electroluminescence device described later is an organic electroluminescence device, which includes a compound of the above formula (1) and a host material, and the host material includes a compound having a structure represented by the above formula (5). A preferred embodiment of an organic electroluminescence device is an organic electroluminescence device, which includes a compound of the above formula (1), the above phosphorescent complex, and a host material, and the host material includes at least two compounds having a structure represented by the above formula (5). In this case, for example, the compound having a structure represented by the above formula (5) preferably includes the above HT1 and HT2.

[0158] The compound having a triazine ring structure is not particularly limited, but is preferably a compound having a structure represented by the following formula (6).

[0159] [ka]

[0160] In the above formula (6), Ar 61 ~Ar 63 are each independently a substituted or unsubstituted monovalent aromatic hydrocarbon group, or a substituted or unsubstituted monovalent heterocyclic group.

[0161] In the above formula (6), the substituted or unsubstituted monovalent aromatic hydrocarbon group is the same as that described for the group (a8) in the above formula (1), and the substituted or unsubstituted monovalent heterocyclic group is the same as that described for the group (a9) in the above formula (1).

[0162] The substituent substituting the monovalent aromatic hydrocarbon group or monovalent heterocyclic group in the above formula (6) is not particularly limited, but is preferably one of those listed as the substituent substituting the groups (a4) to (a10) in the above formula (1). It is also preferable that the silyl group is substituted with an unsubstituted monovalent aromatic hydrocarbon group. The unsubstituted monovalent aromatic hydrocarbon group is the same as the unsubstituted group in the group (a8).

[0163] Among the compounds having a triazine ring structure, compounds containing a silyl group (compounds having a triazine ring structure with a silyl group) are preferred.

[0164] The compound having a triazine ring structure is preferably used in combination with the compound having the above-mentioned carbazole ring structure, or the compound having a ring structure in which one or more of the ring-forming carbon atoms of the carbazole ring are substituted with a nitrogen atom.

[0165] Specific examples of compounds having a triazine ring structure that are host materials according to one embodiment of the present invention are given below, although the present invention is not limited to these specific examples.

[0166] [ka]

[0167] From these facts, an example of a material for an organic electroluminescence device according to a preferred embodiment of the present invention is a material for an organic electroluminescence device that includes a compound of the above formula (1), the above phosphorescent complex, and a host material, the host material including a compound having a structure represented by the above formula (6). Also, an example of a material for an organic electroluminescence device according to a more preferred embodiment of the present invention is a material for an organic electroluminescence device that includes a compound of the above formula (1), the above phosphorescent complex, and a host material, the host material including a compound having a structure represented by the above formula (5) and a compound having a structure represented by the above formula (6). Also, an example of a preferred embodiment of an organic electroluminescence device described later is an organic electroluminescence device that includes a compound of the above formula (1) and a host material, the host material including a compound having a structure represented by the above formula (6). A more preferred embodiment of the organic electroluminescence element includes an organic electroluminescence element comprising a compound of the above formula (1) and a host material, the host material comprising a compound having a structure represented by the above formula (5) and a compound having a structure represented by the above formula (6).

[0168] The content of the host material relative to the total mass of the material for organic electroluminescence device (particularly, the material for 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. In this range, an organic electroluminescence device with excellent color purity of light emission and high light-emitting efficiency can be obtained. The content of the host material relative to the total mass of the material for organic electroluminescence device (particularly, the material for the light-emitting layer) is not particularly limited, but is preferably 99% by mass or less. The content is more preferably 98% by mass or less, and even more preferably 95% by mass or less. In this range, an organic electroluminescence device with excellent color purity of light emission and high light-emitting efficiency can be obtained. 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 electroluminescence device described later is also the same as above.

[0169] When the material for organic electroluminescence devices contains a host material, the content is preferably 1000 parts by mass or more relative to 100 parts by mass of the compound of the above formula (1). 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 compound of the above formula (1). Within this range, an organic electroluminescence device with excellent color purity of light emission and high light emission efficiency can be obtained. The content of the host material is not particularly limited, but is preferably 200000 parts by mass or less relative to 100 parts by mass of the compound of the above formula (1). 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 compound of the above formula (1). Within this range, an organic electroluminescence device with excellent color purity of light emission and high light emission efficiency can be obtained. The preferred content (parts by mass) of the host material relative to 100 parts by mass of the compound of the above formula (1) in the light-emitting layer of the organic electroluminescence device described later is also the same as above.

[0170] <Liquid Composition> Another aspect of the present invention relates to a liquid composition comprising the compound of formula (1) above, the material for an organic electroluminescence device above, and a solvent.

[0171] 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 in the above range, the film-forming property and processability in the wet film-forming method, particularly the inkjet method, are improved. The solvent having a boiling point of 100°C or more and 350°C or less at atmospheric pressure is not particularly limited, and known solvents can be appropriately adopted. Specific examples of solvents having a boiling point of 100°C or more and 350°C or less at atmospheric pressure are shown below, but the present invention is not limited to these specific examples. Examples of hydrocarbon solvents include octane, nonane, decane, undecane, and dodecane. Examples of aromatic hydrocarbon solvents 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 ether-based solvents include 1,4-dioxane, 1,2-diethoxyethane, diethylene glycol dimethylether, diethylene glycol diethylether, anisole, ethoxybenzene, 3-methylanisole, m-dimethoxybenzene, etc. Examples of ketone-based solvents 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.

[0172] In one embodiment of the present invention, the contents of the compound of formula (1) and the material for an organic electroluminescence device in the liquid composition are not particularly limited.

[0173] In one embodiment of the present invention, the liquid composition is preferably used as a coating liquid for forming an organic layer of an organic electroluminescence element. Among the coating liquids for forming an organic layer, the liquid composition is preferably used as a coating liquid for forming a light-emitting layer.

[0174] <Organic electroluminescence element> Another aspect of the present invention relates to an organic electroluminescence device having an emission layer containing the compound of formula (1). In addition, in the organic electroluminescence device, the emission layer preferably contains the compound of formula (1) and a phosphorescent complex, and more preferably contains a host material in addition to the compound of formula (1) and the phosphorescent complex. In this case, the phosphorescent complex is more preferably a platinum complex.

[0175] Another aspect of the present invention relates to an organic electroluminescence device including the material for organic electroluminescence devices. In the organic electroluminescence device, the material for organic electroluminescence devices preferably further includes the host material. In the organic electroluminescence device, the phosphorescent complex contained therein is more preferably a platinum complex.

[0176] In the organic electroluminescence device, the host material contained therein is preferably a compound having the above carbazole ring structure, a compound having a ring structure in which one or more of the ring-forming carbon atoms of the carbazole ring are substituted with a nitrogen atom, or a compound having the above triazine ring structure. In addition, in the organic electroluminescence device, the host material contained therein preferably contains a compound having a structure represented by the above formula (5). In addition, in the organic electroluminescence device, the host material contained therein more preferably contains a compound having a structure represented by the above formula (6). In addition, in the organic electroluminescence device, the host material contained therein more preferably contains a compound having a structure represented by the above formula (5) and a compound having a structure represented by the above formula (6). In addition, in the organic electroluminescence device, the host material contained therein further preferably contains a compound having a structure represented by the above formula (5) and a compound having a structure represented by the above formula (6).

[0177] In the organic electroluminescence device, the phosphorescent complex contained therein is preferably a compound having a structure represented by the above formula (4).

[0178] An organic electroluminescence device according to an embodiment of the present invention includes, but is not limited to, a first electrode, a second electrode, and one or more organic layers. The second electrode is disposed on the first electrode.

[0179] 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.

[0180] An organic electroluminescent device according to one embodiment of the present invention comprises a first electrode, a second electrode, and a single or multiple layers disposed between the first and second electrodes. Here, the layers include at least one organic layer, and at least one of the organic layers includes the compound of formula (1) above or the material for organic electroluminescent devices above. The organic layer including the compound of formula (1) above or the material for organic electroluminescent devices above preferably includes an emitting layer. These organic electroluminescent devices can achieve light emission with high color purity.

[0181] Thus, the light-emitting layer preferably comprises at least one compound of formula (1) above.

[0182] 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.

[0183] The light-emitting layer is not particularly limited, and may contain, for example, a host material and a dopant material. The compound of the above formula (1) may be used as either a host material or a dopant material, but is preferably used as a dopant material.

[0184] From these viewpoints, a preferred embodiment of the present invention includes an organic electroluminescence device including an emission layer, the emission layer including the compound of the above formula (1) or the above material for organic electroluminescence devices. The emission layer is more preferably composed of the above material for organic electroluminescence devices. From the viewpoints of the peak wavelength of the emission spectrum, the color purity of the emission, and the emission efficiency, the material for organic electroluminescence devices preferably includes the above host material in addition to the compound of the above formula (1). From the same viewpoint, the material for organic electroluminescence devices more preferably includes the above phosphorescent complex and the above host material in addition to the compound of the above formula (1). The preferred ranges of the content and content ratio of the compound of the above formula (1), the phosphorescent complex, and the host material in the emission layer are the same as the preferred content and content ratio in the material for organic electroluminescence devices.

[0185] 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 50 nm.

[0186] 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).

[0187] The emission wavelength of the organic electroluminescence element is not particularly limited. The preferred range of the emission wavelength of the organic electroluminescence element is, for example, the same as the peak wavelength of the emission in PL of the compound of formula (1) according to the present invention. Among these, from the specifications of currently commercialized products, in the case of blue light emission, it is preferable to emit light having a peak in the wavelength region of 445 nm or more and 470 nm or less, it is particularly preferable to emit light having a peak in the wavelength region of 450 nm or more and 470 nm or less, and it is extremely preferable to emit light having a peak in the wavelength region of 450 nm or more and 465 nm or less.

[0188] In addition, the smaller the full width at half maximum (FWHM) of the emission spectrum peak of the organic electroluminescence element, the more preferable. In addition, the full width at half maximum (FWHM) of the emission spectrum peak is preferably 30 nm or less, more preferably 25 nm or less, and further preferably 20 nm or less (lower limit value: more than 0 nm).

[0189] Hereinafter, with reference to the attached drawings, a detailed description will be given of an organic electroluminescence device according to an embodiment of the present invention having 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 in the drawings are exaggerated for the convenience of explanation, and may differ from the actual ratios.

[0190] 1 to 3 are schematic cross-sectional views showing an organic electroluminescence element according to one embodiment of the present invention, however, the structure of the organic electroluminescence element according to the present invention is not limited to the forms shown in FIGS.

[0191] 1 is a schematic cross-sectional view showing an organic electroluminescence element according to one embodiment of the present invention. An organic electroluminescence element 10 according to one embodiment of the present invention includes a substrate 1, a first electrode 2, a hole transport region 3, a light-emitting layer 4, an electron transport region 5, and a second electrode 6, which are laminated in this order.

[0192] Fig. 2 is a cross-sectional schematic diagram showing an organic electroluminescence element according to another embodiment of the present invention. An organic electroluminescence element 10 according to one embodiment of the present invention includes a substrate 1, a first electrode 2, a hole transport region 3, a light-emitting layer 4, an electron transport region 5, and a second electrode 6, which are stacked in this order. In Fig. 2, the hole transport region 3 includes a hole injection layer 31 and a hole transport layer 32, which are stacked in this order. Also, in Fig. 2, the electron transport region 5 includes an electron transport layer 52 and an electron injection layer 51, which are stacked in this order.

[0193] Fig. 3 is a schematic cross-sectional view showing an organic electroluminescence element according to another embodiment of the present invention. An organic electroluminescence element 10 according to one embodiment of the present invention includes a substrate 1, a first electrode 2, a hole transport region 3, a light-emitting layer 4, an electron transport region 5, and a second electrode 6, which are stacked in this order. In Fig. 3, the hole transport region 3 includes a hole injection layer 31, a hole transport layer 32, and an electron blocking layer 33, which are stacked in this order. Also, in Fig. 3, the electron transport region 5 includes a hole blocking layer 53, an electron transport layer 52, and an electron injection layer 51, which are stacked in this order.

[0194] The substrate, and each region and layer will now be described in detail.

[0195] (Substrate 1) The organic electroluminescence element 10 may have a substrate 1. A substrate used in a general organic electroluminescence element can be used as the substrate 1. For example, the substrate 1 may be a glass substrate, a semiconductor substrate such as a silicon substrate, a transparent plastic substrate, or the like.

[0196] (1st electrode 2) The first electrode 2 has electrical conductivity. In the organic electroluminescence element according to one embodiment of the present invention, the first electrode 2 is preferably a positive electrode. The first electrode 2 is preferably a pixel electrode. The first electrode 2 is preferably a transmissive electrode, a semi-transmissive electrode, or a reflective electrode.

[0197] The material constituting the first electrode 2 is not particularly limited, and examples thereof include metals, metal alloys, conductive compounds, etc. If the first electrode 2 is a transmissive electrode, the first electrode 2 preferably contains a transparent metal oxide, such as ITO (indium tin oxide), IZO (indium zinc oxide), ZnO (zinc oxide), ITZO (indium tin zinc oxide), etc. If the first electrode 2 is a semi-transmissive electrode or a reflective electrode, the first electrode 2 preferably contains Ag, Mg, Cu, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, LiF / Ca, LiF / Al, Mo, Ti, or a compound or mixture thereof (for example, a mixture of Ag and Mg), etc.

[0198] 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.

[0199] 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 50 nm or more and 300 nm or less.

[0200] (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.

[0201] 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.

[0202] 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 is not limited to this.

[0203] 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.

[0204] 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 HTM1, the following compound HTM2, and the following compound HT3.

[0205] [ka]

[0206] 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.

[0207] The hole buffer layer (not shown) compensates for the resonance distance according to the wavelength of the light emitted from the light emitting layer 4 to increase the light emission efficiency. The material contained in the hole buffer layer (not shown) is not particularly limited, and the material used in the hole buffer layer (not shown) can be used. For example, the compound that can be contained in the hole transport region 3 as described above can be used.

[0208] The electron blocking layer 33 is a layer that serves to prevent the injection of electrons from the electron transport region 5 to the hole transport region 3. There are no particular limitations on the material contained in the electron blocking layer 33, and any known material used for the electron blocking layer 33 can be used. For example, the host material contained in the above-mentioned light-emitting layer (material for organic electroluminescence device) can be mentioned, and the above-mentioned compounds H55, H86, H87, etc., which are host materials, can be mentioned as preferred examples.

[0209] 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 200 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. The thickness of the electron blocking layer 33 is not particularly limited, but is preferably 1 nm or more and 100 nm or less. The thickness of the hole buffer layer (not shown) is not particularly limited as long as it exhibits the function of the hole buffer layer while not interfering with the function as an organic electroluminescence element. When the thickness of the hole transport region 3, the hole injection layer 31, the hole transport layer 32, or the electron blocking layer 33 satisfies the above range, a better hole transport characteristic can be obtained while suppressing the substantial increase in driving voltage.

[0210] 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.

[0211] (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.

[0212] (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.

[0213] 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.

[0214] 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 LiF, LiQ (lithium quinolate), Li 2Examples of the organic metal salt include lanthanum group metals such as O, BaO, NaCl, CsF, and Yb, and metal halides such as RbCl. The electron injection layer 51 is not particularly limited, but may include, for example, an electron transport material described below and an insulating organic metal salt. The organic metal salt is not particularly limited, but may be, for example, a material having an energy band gap of 4 eV or more. Examples of the organic metal salt include metal acetate, metal benzoate, metal acetoacetate, metal acetylacetonate, and metal stearate.

[0215] 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(naphthalene-2-yl)anthracene), LiQ (lithium quinolate), the following compounds ET1 and H91, and the like. Further examples include TRE314 (manufactured by Toray Industries, Inc., electron transport material), and the like.

[0216] [ka]

[0217] 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 (material for organic electroluminescence element), and the above-mentioned compounds H77 and H87, which are host materials, are preferred examples.

[0218] The thickness of the electron transport region 5 is not particularly limited, but is preferably 0.1 nm or more and 200 nm or less, and more preferably 30 nm or more and 150 nm or less. In addition, for each layer constituting the electron transport region 5, the thickness of the electron transport layer 52 is not particularly limited, but is preferably 10 nm or more and 100 nm or less, and more preferably 15 nm or more and 50 nm or less. The thickness of the hole blocking layer 53 is not particularly limited, but is preferably 1 nm or more and 100 nm or less, and more preferably 5 nm or more and 30 nm or less. The thickness of the electron injection layer 51 is not particularly limited, but is preferably, for example, 0.1 nm or more and 10 nm or less, and more preferably 0.3 nm or more and 9 nm or less. When the thickness of the electron injection layer 51 is in the above range, a better electron injection characteristic can be obtained while suppressing a substantial increase in the driving voltage. In addition, when the thickness of the electron transport region 5, the electron injection layer 51, the electron transport layer 52, or the hole blocking layer 53 is in the above range, a better electron transport characteristic can be obtained while suppressing a substantial increase in the driving voltage.

[0219] 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.

[0220] The second electrode 6 is disposed on the electron transport region 5. The second electrode 6 has electrical conductivity. In the organic electroluminescence element according to one embodiment of the present invention, the second electrode 6 is preferably a common electrode or a negative electrode. The second electrode 6 is preferably a transmissive electrode, a semi-transmissive electrode, or a reflective electrode.

[0221] The material constituting the second electrode 6 is not particularly limited, and examples thereof include metals, metal alloys, and conductive compounds. If the second electrode 6 is a transmissive electrode, the second electrode 6 preferably includes a transparent metal oxide, such as ITO, IZO, ZnO, and ITZO. If the second electrode 6 is a semi-transmissive electrode or a reflective electrode, the second electrode 6 preferably includes Ag, Mg, Cu, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, LiF / Ca, LiF / Al, Mo, Ti, or a compound or mixture containing these (for example, a mixture of Ag and Mg).

[0222] 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.

[0223] 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.

[0224] 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.

[0225] In addition, a capping layer (not shown) may be further disposed on the second electrode 6. The capping layer (not shown) is not particularly limited, but may be, for example, α-NPD, NPB, TPD, m-MTDATA, Alq 3 , CuPc, TPD15 (N4,N4,N4',N4'-tetra(biphenyl-4-yl)biphenyl-4,4'-diamine), TCTA (4,4',4"-tri-9-carbazolyltriphenylamine), N,N'-bis(naphthalene-1-yl), or the like.

[0226] The materials constituting each of the above layers and electrodes may be used alone or in combination of two or more.

[0227] In the organic electroluminescence device 10 of FIGS. 1 to 3, the compound of the above formula (1) or the above material for an organic electroluminescence device may be contained in the light-emitting layer 4. Although it is preferable, the compound of formula (1) or the material for an organic electroluminescence device may be contained in the light-emitting layer 4 and an organic layer other than the light-emitting layer 4.

[0228] 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.

[0229] Although the embodiments of the present invention have been described in detail, it is apparent that the same are illustrative and exemplary, not restrictive, and the scope of the present invention should be interpreted by the appended claims.

[0230] The present invention encompasses the following aspects and configurations.

[0231] [1] A compound represented by the following formula (1):

[0232] [ka]

[0233] In formula (1), R 1 ~R 16 At least one of the following formula (2):

[0234] [ka]

[0235] (* indicates the bonding position to the benzene ring) R other than the above-mentioned substituent W 1 ~R 16 each independently represents the following (a1) to (a10): (a1) a hydrogen or deuterium atom; (a2) a halogen atom; (a3) a cyano group; (a4) a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms; (a5) a substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms; (a6) a substituted or unsubstituted arylamino group having 6 to 20 carbon atoms; (a7) substituted or unsubstituted triarylsilyl groups, alkyldiarylsilyl groups, dialkylarylsilyl groups and trialkylsilyl groups (wherein the aryl group is an aryl group having 6 to 20 carbon atoms; the alkyl group is an alkyl group having 1 to 20 carbon atoms); (a8) a substituted or unsubstituted aromatic hydrocarbon group having 6 to 30 carbon atoms; (a9) a substituted or unsubstituted heterocyclic group having 3 to 30 ring atoms; (a10)R 1 ~R 16 A substituted or unsubstituted saturated hydrocarbon group or saturated heterocyclic group having 5 to 9 ring atoms formed by bonding two adjacent groups among the above; is any atom or group of

[0236] [2] R 2 , R 3 , R 6 , R 7 , R 10 , R 11 , R 14 and R 15 At least two of the following are the substituent W:

[0237] [3] An organic electroluminescence device having a light-emitting layer containing the compound according to [1] or [2] above.

[0238] [4] The organic electroluminescence device according to the above [3], wherein the light-emitting layer further contains a phosphorescent complex. EXAMPLES

[0239] 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.

[0240] <Synthesis of Compounds> Compounds 1 to 4 were synthesized according to the following synthesis examples for use in the manufacture of organic electroluminescence devices. Comparative compounds C1 to C4 were also prepared for use in the manufacture of comparative organic electroluminescence devices.

[0241] [ka]

[0242] [Synthesis Example 1] Compound 1 was synthesized according to the following scheme.

[0243] [ka]

[0244] (Synthesis of intermediate 1) Under a nitrogen atmosphere, 6-bromoindole (15 g, 76.5 mmol) and N,N-dimethylformamide (DMF) (600 mL) were placed in a 1 L three-neck flask, and then cooled to 0°C. Sodium hydride (3.7 g, 91.8 mmol) (60 mass% sodium hydride dispersed in liquid paraffin) was added in three portions, and the resulting reaction solution was stirred at 0°C for 1 hour. The reaction solution was then warmed to room temperature, stirred for 1 hour, and cooled to 0°C. 2-(chloromethoxy)ethyltrimethylsilane ("SEM-Cl" in the above scheme) (15.3 g, 91.8 mmol) was gradually added dropwise to the cooled reaction solution, and the solution was stirred at room temperature for 12 hours. Next, the reaction solution was poured onto ice, and the resulting water suspension was extracted with hexane (200 mL x 3). The extracted organic layer was washed with saturated saline (200 mL) and then dried with anhydrous sodium sulfate (desiccant). After removing the anhydrous sodium sulfate from the organic layer, the solvent in the organic layer was distilled off under reduced pressure. The resulting residue was purified using a silica gel column (eluent: hexane) to obtain Intermediate 1 as a colorless liquid. In the above scheme, "SEM" = "(CH 3 ) 3 SiCH 2 CH 2 OCH 2 " The yield of intermediate 1 was 25.5 g (85% yield).

[0245] (Synthesis of intermediate 2) Under a nitrogen atmosphere, magnesium (3.74 g, 153 mmol) and anhydrous tetrahydrofuran (THF) (150 mL) were placed in a 1 L three-neck flask, and a small amount of 1,2-dibromoethane was added and stirred at room temperature for 30 minutes. A solution of 2,4,6-tri-tert-butylbromobenzene (25 g, 76.9 mmol) in anhydrous tetrahydrofuran (150 mL) was gradually added dropwise to this reaction solution, and the mixture was stirred at 60°C for 2 hours to prepare a Grignard solution. In a separate 1 L three-neck flask, intermediate 1 (12.5 g, 38.4 mmol), tris(dibenzylideneacetone)dipalladium(0) (see "Pd 2 (dba) 3") (1.76 g, 1.92 mmol), 2-dicyclohexylphosphino-2'-6'-dimethoxybiphenyl ("SPhos" in the above scheme) (1.58 g, 3.84 mmol) and toluene (100 mL) were added and stirred. The Grignard solution prepared above was added dropwise to this solution at room temperature, and the resulting reaction solution was stirred at 70 ° C for 10 hours. The reaction solution was then cooled to room temperature, and the insoluble components of the reaction solution were removed using Celite. The organic layer of the reaction solution was washed with saturated saline (200 mL x 2), and then the organic layer was dried with anhydrous sodium sulfate (desiccant). After removing the anhydrous sodium sulfate from the organic layer, the solvent of the organic layer was distilled off under reduced pressure. The resulting residue was dissolved in DMF (100 mL), and tetrabutylammonium fluoride hydrate (30.1 g, 115 mmol) and ethylenediamine (6.92 g, 115 mmol) were added to this solution, and the mixture was stirred at 100 ° C for 6 hours. The resulting reaction solution was cooled to room temperature, added to 200 ml of water, and the solution was extracted with ethyl acetate (200 mL x 3). The extracted organic layer was washed with saturated saline (300 mL) and then dried over anhydrous sodium sulfate (desiccant). After removing the anhydrous sodium sulfate from the organic layer, the solvent in the organic layer was distilled off under reduced pressure. The resulting residue was purified using a silica gel column (eluent; hexane:ethyl acetate (volume ratio) = 95:5). Intermediate 2 was obtained as a white solid. Yield of intermediate 2 was 7.0 g (yield 50%).

[0246] (Synthesis of intermediate 3) Under a nitrogen atmosphere, 5-tert-butyl-2-chlorobenzaldehyde (2.2 g, 11.1 mmol), intermediate 2 (4.0 g, 11.1 mmol) and 110.6 mL of acetonitrile were placed in a 100 mL three-neck flask. The resulting reaction solution was heated to 80°C, and then 57% by mass hydroiodic acid (0.3 mL, 2.2 mmol) was added and stirred for 2 hours. The reaction solution was allowed to cool to room temperature, and the precipitated solid was filtered off and washed with chilled acetonitrile to obtain intermediate 3 as a white powder. Yield of intermediate 3 was 4.3 g (yield 73%).

[0247] (Synthesis of Compound 1) Under a nitrogen atmosphere, intermediate 3 (4.3 g, 4.1 mmol), tetrabutylammonium hydroxide (37% by mass solution in methanol) (17.2 mL, 20.3 mmol), copper (I) iodide (3.9 g, 20.3 mmol) and dimethylformamide (41 mL) were placed in a 100 mL three-neck flask, and the resulting reaction solution was heated and stirred at 140 ° C. The reaction solution was reacted for 24 hours while adding tetrabutylammonium hydroxide (37% by mass solution in methanol) (17.2 mL, 20.3 mmol) and copper (I) iodide (3.9 g, 20.3 mmol) every 8 hours. After that, the reaction solution was allowed to cool to room temperature, and the precipitated solid was filtered off. The filtered solid, 200 mL of methanol and 50 mL of ethylenediamine were added to a 500 mL Erlenmeyer flask, stirred, and the solid was filtered off. The obtained solid was dispersed and washed with THF-acetone, and compound 1 was obtained as a yellow solid. Yield of compound 1: 1.5 g (35% yield) LC-MS: 1005 ([M+H] + ).

[0248] [Compound data for compound 1 (identification data)] The structure of the obtained compound 1 was confirmed by nuclear magnetic resonance ( 1 Identification by H-NMR: NMR data (400MHz, CD 2 Cl 2 )(ppm) 1.24(36H,s),1.47(18H,s),1.85(18H,s),7.61(2H,dd,J=7.8,1.2Hz),7.69(4H,s),7.76(2H,dd,J=8 .7,1.8Hz),8.03(2H,d,J=8.7Hz),8.14(2H,d,J=1.2Hz),8.55(2H,d,J=7.8Hz),8.69(2H,d,J=1.8Hz).

[0249] [Synthesis Example 2] Compound 2 was synthesized according to the following scheme.

[0250] [ka]

[0251] (Synthesis of intermediate 4) The synthesis was carried out in the same manner as for intermediate 3. Intermediate 4 was obtained using intermediate 2 (3.96 g, 10.95 mmol) and 3',5'-di-(tert-butyl)-3-chloro-4-formyl-[1,1'-biphenyl] (3.6 g, 10.95 mmol). Yield: 4.64 g (63%).

[0252] (Synthesis of compound 2) The synthesis was carried out in the same manner as for compound 1. The synthesis was carried out using intermediate 4 (2.32 g, 1.73 mmol), and compound 2 was obtained as a yellow solid. Yield: 1.75 g (80%) LC-MS: 1269 ([M] + ).

[0253] [Synthesis Example 3] Compound 3 was synthesized according to the following scheme.

[0254] [ka]

[0255] (Synthesis of intermediate 5) The synthesis was carried out in the same manner as for intermediate 1. Intermediate 5 was obtained as a colorless liquid using 5-bromoindole (15 g, 76.5 mmol). Yield: 25.7 g (85%).

[0256] (Synthesis of intermediate 6) The synthesis was carried out in the same manner as for intermediate 2. Intermediate 6 was obtained as a white solid using intermediate 5 (25 g, 127 mmol). Yield 7.0 g (30%).

[0257] (Synthesis of intermediate 7) The synthesis was carried out in the same manner as for intermediate 3. Intermediate 7 was obtained using intermediate 6 (3.96 g, 10.95 mmol) and 3',5'-di-(tert-butyl)-3-chloro-4-formyl-[1,1'-biphenyl] (3.6 g, 10.95 mmol). Yield: 3.1 g (43%).

[0258] (Synthesis of compound 3) The synthesis was carried out in the same manner as for compound 1. The synthesis was carried out using intermediate 7 (2.12 g, 1.58 mmol), and compound 3 was obtained as a yellow solid. Yield: 1.2 g (60%) LC-MS: 1269 ([M] + ).

[0259] [Synthesis Example 4] Compound 4 was synthesized according to the following scheme.

[0260] [ka]

[0261] (Synthesis of intermediate 8) The synthesis was carried out in the same manner as for intermediate 3. Intermediate 8 was obtained using intermediate 6 (2.7 g, 7.6 mmol) and 3-chloro-5,5,8,8-tetramethyl-2-formyl-5,6,7,8-tetrahydronaphthalene (1.9 g, 7.6 mmol). Yield: 3.6 g (40%).

[0262] (Synthesis of compound 4) The synthesis was carried out in the same manner as for compound 1. The reaction was carried out using intermediate 8 (3.0 g, 2.5 mmol), and compound 4 was obtained as a yellow solid. Yield: 1.9 g (68%) LC-MS: 1114 ([M+H] + ).

[0263] <Emission spectrum of solution> [Measurement method] The concentration of the compound is 1×10 -7 M (=mol / dm 3A toluene solution of 1,2-dichlorophenyl ether (1,2-dichlorophenyl ether, 1,2-dichlorophenyl ether) was measured at room temperature using a Hitachi High-Tech F-7000 spectrofluorophotometer with an excitation wavelength of 320 nm to obtain a photoluminescence (PL) fluorescence emission spectrum. The peak wavelength and emission spectrum width were read from the emission spectrum measurement results. The wavelength showing the maximum value of the emission spectrum was defined as the "emission peak wavelength," the wavelength width corresponding to half the maximum value as the "half width at half maximum (FWHM)," and the wavelength width corresponding to a quarter of the maximum value as the "FWQM."

[0264] 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 475 nm or less.

[0265] In this evaluation, it is considered that the smaller the emission spectral widths FWHM and FWQM, the more preferable, and the higher the color purity.

[0266] Table 1 shows the emission peak wavelengths (nm) and emission spectral widths (FWHM and FWQM) of the emission spectra of the toluene solutions of Compounds 1 to 4 and Comparative Compound C1 measured by the above method.

[0267] FIG. 4 shows the emission spectra of the toluene solutions of compound 1 and comparative compound C1 measured by the above method.

[0268] [Table 1]

[0269] As shown in Table 1, the emission peak wavelengths of compounds 1 to 4 of the present invention were 454 to 460 nm, and they emitted blue light. In addition, the FWQM of compounds 1 to 4 was 17 to 22 nm, which was 13 to 18 nm smaller than that of comparative compound C1. This is considered to be the result of suppressing the secondary emission peak intensity due to the effect of the substituent W (tri-tert-butylphenyl group) introduced into compounds 1 to 4. As shown in the emission spectrum in FIG. 4, the emission spectrum peak of compound 1 of the present invention is longer than that of comparative compound C1, and it can be seen that it is suitable for blue light emission.

[0270] <Thin film properties> [Method of preparing thin film] On a quartz substrate, the compounds shown in Tables 2 and 3 were each deposited in a weight ratio of 1% by mass relative to the host compound. -5 The compound HT1 and the compound HT2 were used as host compounds, and the mass ratio of the compound HT1 to the compound HT2 was 60:40. The structures of HT1 and HT2 are as follows:

[0271] [ka]

[0272] [Photoluminescence (PL) measurement (FWHM)] A thin film (host dispersion film) made using the compound in Table 2 was cut into a 6 mm wide strip and PL measurement was performed at room temperature using a Hitachi High-Technologies Corporation F-7000 spectrofluorophotometer. From the obtained emission spectrum, the peak wavelength (maximum emission wavelength) and the wavelength width at which the emission intensity is reduced by half (FWHM) were calculated. The evaluation results are shown in Table 2 below.

[0273] FIG. 5 shows the emission spectra of the thin films (host-dispersed films) prepared using compound 1 and comparative compound C1.

[0274] [Table 2]

[0275] The emission wavelengths of the compounds 1 and 2 of the present invention are 459 nm and 466 nm, which are blue light emission, similar to the solution. Furthermore, the FWHM of the emission spectrum of the compounds 1 and 2 of the present invention is 17 nm and 19 nm, and the difference from the FWHM of the spectrum in solution is smaller than that of the comparative compound C1. This is thought to be because the newly introduced sterically bulky substituent W of the compounds 1 and 2 of the present invention effectively suppresses the aggregation between molecules in the host dispersion state, thereby reducing the increase in FWHM. On the other hand, the comparative compound C1 has an emission wavelength of 457 nm, which is blue light emission, but the FWHM is a large value of 24 nm, and the spectral shape is also different from that of the solution. This is thought to be because the comparative compound C1 is a planar molecule, and aggregation occurs between the comparative compounds C1, which increases the FWQM.

[0276] [PLQY measurement] The PLQY of the thin film (host dispersion film) prepared using the compounds in Table 3 was measured using a Quantaurus-QY absolute PL quantum yield (PLQY) measurement device C11347-01 manufactured by Hamamatsu Photonics K.K. During the measurement, the excitation wavelength was scanned from 280 nm to 350 nm at 10 nm intervals, and the excitation wavelength region in which the absorption value of the compound showed an excitation light intensity ratio of 20% or more was adopted. The PLQY value was taken as the highest value within the excitation wavelength region adopted. These evaluation results are shown in Table 3 below.

[0277] [Table 3]

[0278] It can be seen that Compound 1 of the present invention has a 11% higher PLQY than Comparative Compound C1. Also, it can be seen that Compound 1 has a significantly higher PLQY than Comparative Compound C4 which has a bulky substituent of di-tert-butylphenyl group instead of substituent W (tri-tert-butylphenyl group). From this, it can be understood that the aggregation inhibitory effect by substituent W (tri-tert-butylphenyl group) is high, and Compound 1 is excellent as a light-emitting dopant.

[0279] <OLED Device Evaluation> [Fabrication of Organic EL Device] (Preparation of Materials for Forming Each Layer) As materials used for forming each layer of the organic EL device, in addition to the above-obtained Compound 1 and Compound 2, and Comparative Compound C1, the following materials were prepared.

[0280]

Chemical Formula

[0281] ≪Fabrication of Organic EL Device 1≫ (Example 1) The ITO glass substrate with an electrode pattern was cut into a size of 50 mm × 50 mm × 0.7 mm, ultrasonically cleaned in acetone, isopropyl alcohol, and pure water in that order for 15 minutes each, and then UV ozone cleaned for 30 minutes. On the ITO electrode (anode) on this glass substrate, the following layers were deposited using a vacuum deposition apparatus.

[0282] First, HAT-CN was deposited on the above ITO electrode to form a hole injection layer with a film thickness of 10 nm. Next, Compound HT3 was deposited on the hole injection layer to form a hole transport layer with a film thickness of 140 nm. Subsequently, Compound HT1 was deposited on the hole transport layer to form an electron blocking layer with a thickness of 5 nm. In this way, a hole transport region was formed.

[0283] Compound HT1, compound HT2, and compound 1 obtained above were co-deposited on the hole transport region obtained above to form an emitting layer having a thickness of 40 nm. Here, the emitting layer was formed so that the mass ratio of compound HT1 and compound HT2 in the emitting layer was compound HT1:compound HT2=60:40. The emitting layer was also formed so that the concentration of compound 1 in the emitting layer was 1.5 mass% with respect to the total mass of compound HT1, compound HT2, and compound 1 (i.e., the total mass of the emitting layer). Compound HT1 and compound HT2 are host materials.

[0284] Compound HT2 was vacuum-deposited on the light-emitting layer obtained above to form a hole-blocking layer with a thickness of 5 nm. Compound H91 and LiQ were then co-deposited on the hole-blocking layer in a mass ratio of compound H91:LiQ=5:5 (unit: parts by mass) to form an electron-transporting layer with a thickness of 30 nm. LiQ was then vapor-deposited on the electron-transporting layer to form an electron-injecting layer with a thickness of 1 nm. In this manner, an electron-transporting region was formed.

[0285] An organic EL device was prepared by depositing Al (cathode) having a thickness of 100 nm on the electron injection layer obtained above.

[0286] 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 can with a desiccant and an ultraviolet curing resin (MORESCO, product name WB90US). In this way, the organic EL element was completed.

[0287] Example 2 An organic EL element was produced in the same manner as in Example 1, except that in the film formation of the light-emitting layer in Example 1, compound 1 in the light-emitting layer was changed to compound 2, and the organic EL element was completed by sealing.

[0288] Comparative Example 1 An organic EL element was produced in the same manner as in Example 1, except that in the film formation of the light-emitting layer in Example 1, compound 1 in the light-emitting layer was changed to comparative compound C1, and the organic EL element was completed by sealing.

[0289] <<Preparation of organic EL element 2>> Example 3 The ITO glass substrate with the electrode pattern was cut to a size of 50 mm x 50 mm x 0.7 mm, and ultrasonically cleaned with 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.

[0290] First, HAT-CN was evaporated on the ITO electrode to form a hole injection layer with a thickness of 10 nm. Then, compound HT3 was evaporated on the hole injection layer to form a hole transport layer with a thickness of 140 nm. Then, compound HT1 was evaporated on the hole transport layer to form an electron blocking layer with a thickness of 5 nm. In this way, a hole transport region was formed.

[0291] On the hole transport region obtained above, compound HT1, compound HT2, phosphorescent complex P1, and compound 1 obtained above were co-deposited to form an emitting layer having a thickness of 40 nm. Here, the emitting layer was formed so that the mass ratio of compound HT1, compound HT2, and phosphorescent complex P1 in the emitting layer was compound HT1: compound HT2: phosphorescent complex P1 = 60: 40: 13. The emitting layer was also formed so that the concentration of compound 1 in the emitting layer was 0.4 mass% with respect to the total mass of compound HT1, compound HT2, phosphorescent complex P1, and compound 1 (i.e., the total mass of the emitting layer). Compound HT1 and compound HT2 are host materials.

[0292] Compound HT2 was vacuum-deposited on the light-emitting layer obtained above to form a hole-blocking layer with a thickness of 5 nm. Compound H91 and LiQ were then co-deposited on the hole-blocking layer in a mass ratio of compound H91:LiQ=5:5 (unit: parts by mass) to form an electron-transporting layer with a thickness of 30 nm. LiQ was then vapor-deposited on the electron-transporting layer to form an electron-injecting layer with a thickness of 1 nm. In this manner, an electron-transporting region was formed.

[0293] An organic EL device was prepared by depositing Al (cathode) having a thickness of 100 nm on the electron injection layer obtained above.

[0294] 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 can with a desiccant and an ultraviolet curing resin (MORESCO, product name WB90US). In this way, the organic EL element was completed.

[0295] Example 4 An organic EL element was produced in the same manner as in Example 3, except that in the film formation of the light-emitting layer in Example 3, compound 1 in the light-emitting layer was changed to compound 2, and the organic EL element was completed by sealing.

[0296] Comparative Example 2 An organic EL element was produced in the same manner as in Example 3, except that in the film formation of the light-emitting layer in Example 3, compound 1 in the light-emitting layer was changed to comparative compound C1, and the organic EL element was completed by sealing.

[0297] <Evaluation of organic EL elements> The organic EL devices of Examples 1 to 4 and Comparative Examples 1 and 2 were measured for a luminance of 1,000 cd / m according to the following method. 2 The emission peak wavelength, emission spectral width (FWHM), and external quantum yield were evaluated.

[0298] [External quantum yield] Using a DC constant voltage power supply (KEITHLEY, source meter 2400 type), 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 (Hamamatsu Photonics K.K., multichannel spectrometer PMA12).

[0299] Here, the external quantum yield was calculated from the emission spectrum, luminance, and the current value at the time of measurement. 2 The external quantum yield at was defined as EQE [%].

[0300] [Emission peak wavelength and emission spectral width (FWHM)] The emission peak wavelength and the emission spectrum width (FWHM) were read from the emission spectrum measurement results.

[0301] 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 475 nm or less.

[0302] In this evaluation, the smaller the emission spectrum width (FWHM), the more preferable it is, and it is judged to be excellent in high color purity.

[0303] The evaluation results of the organic EL devices of Examples 1 to 4 and Comparative Examples 1 and 2 are shown in Tables 4 and 5.

[0304] [Table 4]

[0305] [Table 5]

[0306] The organic EL devices prepared using the compounds 1 and 2 of the present invention as luminescent materials have higher external quantum yields than the organic EL devices prepared using the comparative compound C1 as luminescent materials. This is because the sterically bulky substituents in the compounds of the present invention contribute to improved efficiency by suppressing aggregation. In addition, the FWHMs of Examples 1 to 4 are smaller than those of the corresponding Comparative Examples 1 and 2, respectively, and it is clear that the compounds of the present invention are excellent as luminescent dopants.

[0307] As described above, it was confirmed that the organic EL devices of Examples 1 to 4, which contain the compound according to the present invention, have narrower half-width FWHM of the emission spectrum, realize emission with high color purity, and have excellent external quantum yield. That is, by using the compound according to the present invention as a light-emitting material, it is possible to prepare a blue electroluminescent device with narrower spectrum width than conventional light-emitting materials, high efficiency, and high performance and color purity.

[0308] Thus, the compound according to the present invention exhibited precisely adjusted blue emission color, good high color purity, and high luminous efficiency in an organic EL device. In particular, when used in combination with a phosphorescent material, it exhibited a remarkable improvement in luminous efficiency. These results are considered to fully satisfy the specifications required for future wide-gamut devices such as BT2100, and will enable the realization of high-definition next-generation displays.

[0309] The present invention has been described above with reference to embodiments and examples. However, the present invention is not limited to the specific embodiments and examples, and various modifications and changes are possible within the scope of the invention described in the claims. [Explanation of symbols]

[0310] 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 element.

Claims

1. A compound represented by the following formula (1): 【Chemistry 1】 In formula (1), R １ ~R １６ At least one of the following formula (2): 【Chemistry 2】 (* represents the bonding position to the benzene ring), R other than the substituent W １ ~R １６ each independently represents the following (a1) to (a10): (a1) a hydrogen or deuterium atom; (a2) a halogen atom; (a3) a cyano group; (a4) a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms; (a5) a substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms; (a6) a substituted or unsubstituted arylamino group having 6 to 20 carbon atoms; (a7) a substituted or unsubstituted triarylsilyl group, alkyldiarylsilyl group, dialkylarylsilyl group, or trialkylsilyl group (wherein the aryl group is an aryl group having from 6 to 20 carbon atoms; the alkyl group is an alkyl group having from 1 to 20 carbon atoms); (a8) a substituted or unsubstituted aromatic hydrocarbon group having 6 to 30 carbon atoms; (a9) a substituted or unsubstituted heterocyclic group having 3 to 30 ring atoms; and (a10) R １ ~R １６ a substituted or unsubstituted saturated hydrocarbon group or saturated heterocyclic group having 5 to 9 ring atoms formed by bonding two adjacent groups among the above; is any atom or group of

2. R ２ , R ３ , R ６ , R 7 , R １０ , R １１ , R １４ and R １５ The compound according to claim 1 , wherein at least two of the following are the substituent W:

3. An organic electroluminescence device having a light-emitting layer comprising the compound according to claim 1 or 2.

4. The organic electroluminescence device according to claim 3 , wherein the light-emitting layer further comprises a phosphorescent complex.

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