Polycyclic aromatic compound and organic electroluminescent element

Abstract

A polycyclic aromatic compound represented by formula (1), an organic electroluminescent element, a display device, and a lighting device. The definition of # imgabs0 # formula (1) is the same as that described in the embodiment.

Description

Technical Field

[0001] The present invention relates to polycyclic aromatic compounds. The present invention also relates to materials for organic devices, organic electroluminescent elements, and display devices and lighting devices including the polycyclic aromatic compounds. Background Art

[0002] Previously, display devices using light-emitting elements that perform electroluminescence have been studied in various ways because they can achieve power saving or thinning. Furthermore, organic electroluminescence (EL) elements containing organic materials (sometimes referred to as "organic EL elements" or simply "elements" in this specification) have been actively studied because they can be easily made lightweight or large-sized. In particular, regarding the development of organic materials having light-emitting characteristics such as blue, which is one of the three primary colors of light, and regarding the development of organic materials having charge transport capabilities (with the possibility of becoming semiconductors or superconductors) including holes, electrons, etc., both high-molecular compounds and low-molecular compounds have been actively studied to date.

[0003] An organic EL element has a structure including: a pair of electrodes including an anode and a cathode, and one or more layers disposed between the pair of electrodes and containing an organic compound. In the layer containing the organic compound (sometimes referred to as the "organic layer" in this specification), there are a light-emitting layer, or charge transport / injection layers that transport or inject charges such as holes and electrons, and various organic materials suitable for these layers have been developed.

[0004] Here, Patent Document 1 discloses that polycyclic aromatic compounds formed by linking aromatic rings with hetero elements such as boron, phosphorus, oxygen, nitrogen, and sulfur can be effectively used as materials for organic electroluminescent elements and the like. Regarding the polycyclic aromatic compounds, it has been reported that they have a large highest occupied molecular orbital (HOMO)-lowest unoccupied molecular orbital (LUMO) gap and a high lowest excited triplet energy level (ET), and exhibit thermally activated delayed fluorescence, and thus can be particularly effectively used as fluorescent materials for organic electroluminescent elements.

[0005] Prior Art Documents

[0006] Patent Documents

[0007] (Patent Document 1) Patent Document 1: International Publication No. 2015 / 102118 Summary of the Invention

[0008] Technical Problem to be Solved

[0009] As described above, various materials have been developed as materials used in organic EL elements. However, in order to increase the options for materials for organic EL elements, it is desired to develop a material containing a compound different from those in the past. The subject of the present invention is to provide a novel material that can be effectively used as a material for organic devices such as organic EL elements.

[0010] Another subject of the present invention is to provide an organic electroluminescent element using a combination of new materials. In particular, the subject of the present invention is to provide an organic EL element having a high external quantum efficiency.

[0011] Means for Solving the Problems

[0012] The inventors of the present invention made diligent studies to solve the above problems, and thus succeeded in manufacturing a new compound which is a polycyclic aromatic compound formed by connecting aromatic rings with hetero elements such as boron, phosphorus, oxygen, nitrogen, and sulfur. In addition, it was found that by forming an organic EL element by disposing a layer containing the polycyclic aromatic compound between a pair of electrodes, an excellent organic EL element can be obtained, and thus the present invention was completed. That is, the present invention provides a polycyclic aromatic compound as described below, and further provides a material for organic devices containing a polycyclic aromatic compound as described below.

[0013] <1> A polycyclic aromatic compound represented by the following formula (1):

[0014]

[0015] In the formula (1),

[0016] the A ring, B ring, C ring, D ring, and E ring are each independently a substituted or unsubstituted aryl ring or a substituted or unsubstituted heteroaryl ring,

[0017] wherein at least one of the A ring, B ring, C ring, D ring, and E ring is a substituted or unsubstituted monocyclic heteroaryl ring,

[0018] wherein at least one of the A ring, B ring, C ring, D ring, and E ring has a group represented by the formula (2) as a substituent,

[0019] L are each independently a single bond, >O, >N-R NX , >C(-R CX )2, -C(-R CX )=C(-R CX )-, >Si(-R IX )2, >S, >CO, >CS, >SO, >SO2, >SeO, >SeO2, >PO, >B(-R PX ) or >Se,

[0020] R NX 、R CX 、R IX and R PX are each independently hydrogen, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted alkyl, or substituted or unsubstituted cycloalkyl, and the two R CX may be bonded to each other to form a ring, and the two R IX may be bonded to each other to form a ring.

[0021] In the structure, at least one selected from the group consisting of an aryl ring and a heteroaryl ring may be condensed with at least one cycloalkane, the cycloalkane may be substituted with at least one substituent, and at least one -CH2- in the cycloalkane may be substituted with -O-.

[0022] In formula (2),

[0023] * represents the bonding position to the aryl ring or heteroaryl ring.

[0024] The F ring is a substituted or unsubstituted aryl ring or a substituted or unsubstituted heteroaryl ring.

[0025] R is a substituted or unsubstituted aryl ring, a substituted or unsubstituted heteroaryl ring, a substituted or unsubstituted alkyl, or a substituted or unsubstituted cycloalkyl.

[0026] In formula (1) and formula (2), at least one hydrogen may be substituted with deuterium, cyano or halogen, at least one nitrogen may be substituted with nitrogen-15 ( 15 N), at least one sulfur may be substituted with sulfur-33 ( 33 S), sulfur-34 ( 34 S) or sulfur-36 ( 36 S), at least one oxygen may be substituted with oxygen-17 ( 17 O) or oxygen-18 ( 18 O), at least one carbon may be substituted with carbon-13 ( 13 C), and at least one boron may be substituted with boron-11 ( 11 B).

[0027] <2> In a polycyclic aromatic compound, the formula (1) described in <1> is represented by the following formula (1'):

[0028]

[0029] In formula (1'),

[0030] L has the same definition as L in formula (1),

[0031] Z is independently -C(-R ZE) = or -N=, where at least one of Z is -N=,

[0032] R ZE are each independently selected from the group consisting of hydrogen, deuterium, halogen, cyano, nitro, substituted or unsubstituted silyl, substituted or unsubstituted amino, substituted or unsubstituted alkyl having 1 to 10 carbon atoms, substituted or unsubstituted cycloalkyl having 3 to 30 carbon atoms, substituted or unsubstituted aryl having 6 to 30 carbon atoms, substituted or unsubstituted heteroaryl having 2 to 30 carbon atoms, and the group represented by formula (2'), wherein substituents substituted on adjacent atoms may be bonded to each other to form a ring,

[0033] wherein at least one of R ZE has the group represented by formula (2').

[0034] In formula (2'),

[0035] R has the same definition as R in formula (2), and * represents the bonding position to R ZE .

[0036] <3> In the polycyclic aromatic compound, R described in <2> is a substituted or unsubstituted aryl ring, a substituted or unsubstituted heteroaryl ring, a substituted or unsubstituted alkyl, or a substituted or unsubstituted cycloalkyl.

[0037] <4> In the polycyclic aromatic compound, formula (1') described in <2> is represented by any one of the following chemical formulas (1'-1) to (1'-7):

[0038]

[0039] In chemical formulas (1'-1) to (1'-7),

[0040] L has the same definition as L in formula (1),

[0041] and at least one ring has the group represented by formula (2) as a substituent.

[0042] <5> In the polycyclic aromatic compound, formula (1') described in <2> is represented by the following formula (1"):

[0043]

[0044] In formula (1"),

[0045] Z has the same definition as in formula (1').

[0046] <6>In a polycyclic aromatic compound, the formula (1") described in <5> is represented by any one of the following chemical formulas (1"-1) to (1"-7):

[0047]

[0048] In chemical formulas (1"-1) to (1"-7),

[0049] at least one ring has a group represented by formula (2) as a substituent.

[0050] <7>In a polycyclic aromatic compound, the formula (1") described in <5> is represented by any one of the following chemical formulas (1"-1) to (1"-4), (1"-6), and (1"-7):

[0051]

[0052] In chemical formulas (1"-1) to (1"-4), (1"-6), and (1"-7),

[0053] at least one ring has a group represented by formula (2) as a substituent.

[0054] <8>In a polycyclic aromatic compound, the formula (2) described in <1> is represented by any one of the following chemical formulas (2-1) to (2-7):

[0055]

[0056] In chemical formulas (2-1) to (2-7), * represents the bonding position to an aryl ring or a heteroaryl ring.

[0057] <9>In a polycyclic aromatic compound, the formula (1) described in <1> is represented by any one of the following chemical formulas:

[0058]

[0059]

[0060] <10>An organic electroluminescent element includes: a pair of electrodes composed of an anode and a cathode; and an organic layer disposed between the pair of electrodes, the organic layer including the polycyclic aromatic compound described in any one of <1> to <9>.

[0061] <11>In the organic electroluminescent element, the organic layer described in <10> is a light-emitting layer.

[0062] <12>In an organic electroluminescent element, the light-emitting layer described in <11> includes a host material and the polycyclic aromatic compound as a dopant material.

[0063] <13>In an organic electroluminescent element, the host material described in <12> is an anthracene compound, a fluorene compound, or a dibenzo (dibenzo chrysene) compound.

[0064] <14>In an organic electroluminescent element, the light-emitting layer described in <11> includes a host material, a thermally activated delayed phosphor or a phosphorescent material, and a polycyclic aromatic compound as a light-emitting dopant.

[0065] Technical effects

[0066] According to the present invention, a new polycyclic aromatic compound is provided. The polycyclic aromatic compound of the present invention is useful as a material for organic devices, particularly as a material for a light-emitting layer for forming a light-emitting layer of an organic electroluminescent element. Description of the drawings

[0067] Figure 1 is a schematic cross-sectional view showing an example of an organic EL element. Detailed description

[0068] Hereinafter, the present invention will be described in detail. The description of the constituent elements described below is sometimes based on representative embodiments or specific examples, but the present invention is not limited to such embodiments. In addition, in this specification, the numerical range represented by "~" means a range including the numerical values described before and after "~" as the lower limit value and the upper limit value. In addition, in this specification, "hydrogen" in the description of the structural formula means "hydrogen atom (H)".

[0069] In this specification, when referring to "adjacent groups", it means two groups bonded to two adjacent atoms (two atoms directly bonded by a covalent bond) in the structural formula, respectively.

[0070] In this specification, the chemical structure or substituents are sometimes represented by the number of carbon atoms. However, when a substituent is substituted in the chemical structure, or when a substituent is further substituted on the substituent, etc., the number of carbon atoms refers to the number of carbon atoms of each of the chemical structure or the substituent, and does not refer to the total number of carbon atoms of the chemical structure and the substituent, or the total number of carbon atoms of the substituent and the substituent. For example, the so-called "substituent B having a carbon number of Y substituted with a substituent A having a carbon number of X" means that the "substituent A having a carbon number of X" is substituted on the "substituent B having a carbon number of Y", and the carbon number Y is not the total number of carbon atoms of substituent A and substituent B. In addition, for example, the so-called "substituent B having a carbon number of Y substituted with a substituent A" means that the "(substituent A having an unspecified carbon number)" is substituted on the "substituent B having a carbon number of Y", and the carbon number Y is not the total number of carbon atoms of substituent A and substituent B.

[0071] 1. Polycyclic aromatic compound

[0072] 1-1. Polycyclic aromatic compound

[0073] The present invention relates to a polycyclic aromatic compound represented by formula (1). The polycyclic aromatic compound is useful as a compound for forming elements with high efficiency and long life. In addition, compared with similar compounds having the same molecular weight, it is not easily decomposed during evaporation deposition.

[0074] <Explanation of formula (1)>

[0075] Hereinafter, in this specification, the polycyclic aromatic compound represented by the following formula (1) will be described.

[0076]

[0077] In formula (1), "A", "B", "C", "D" and "E" are each independently a label representing a ring structure.

[0078] In formula (1), the A ring, B ring, C ring, D ring and E ring are each independently a substituted or unsubstituted aryl ring, or a substituted or unsubstituted heteroaryl ring.

[0079] Among them, at least one of the A ring, B ring, C ring, D ring and E ring is a substituted or unsubstituted monocyclic heteroaryl ring.

[0080] As the "aryl ring" in the A ring, B ring, C ring, D ring and E ring in formula (1), for example, an aryl ring having 6 to 30 carbon atoms can be cited, preferably an aryl ring having 6 to 16 carbon atoms, more preferably an aryl ring having 6 to 12 carbon atoms, and particularly preferably an aryl ring having 6 to 10 carbon atoms.

[0081] As specific "aryl rings", examples include: a benzene ring which is a monocyclic system, a biphenyl ring which is a bicyclic system, a naphthalene ring and an indene ring which are condensed bicyclic systems, a terphenyl ring (meta-terphenyl, ortho-terphenyl, para-terphenyl) which is a tricyclic system, an acenaphthene ring, a fluorene ring, a phenalene ring, a phenanthrene ring and an anthracene ring which are condensed tricyclic systems, a triphenylene ring, a pyrene ring, a tetracene ring which are condensed tetracyclic systems, a perylene ring, a pentacene ring and the like which are condensed pentacyclic systems. In addition, the fluorene ring, the benzo[b]fluorene ring and the indene ring respectively contain structures in which a fluorene ring, a benzo[b]fluorene ring, a cyclopentane ring or the like is spiro-bonded. Further, the fluorene ring, the benzo[b]fluorene ring and the indene ring also contain rings in which two of the two hydrogens of the methylene group are respectively substituted with an alkyl group such as a methyl group which is a first substituent described later to form a dimethylfluorene ring, a dimethylbenzo[b]fluorene ring and a dimethylindene ring.

[0082] As the "heteroaryl ring" in ring A, ring B, ring C, ring D and ring E in formula (1), for example, a heteroaryl ring having 2 to 30 carbon atoms can be mentioned, preferably a heteroaryl ring having 2 to 25 carbon atoms, more preferably a heteroaryl ring having 2 to 20 carbon atoms, still more preferably a heteroaryl ring having 2 to 15 carbon atoms, and particularly preferably a heteroaryl ring having 2 to 10 carbon atoms. In addition, as the "heteroaryl ring", for example, a heterocyclic ring containing 1 to 5 heteroatoms selected from oxygen, sulfur and nitrogen as ring-constituting atoms in addition to carbon can be mentioned.

[0083] As specific "heteroaryl rings", for example, the following can be cited: pyrrole ring, oxazole ring, isoxazole ring, thiazole ring, isothiazole ring, imidazole ring, oxadiazole ring, thiadiazole ring, triazole ring, tetrazole ring, pyrazole ring, pyridine ring, pyrimidine ring, pyridazine ring, pyrazine ring, triazine ring, indole ring, isoindole ring, 1H-indazole ring, benzimidazole ring, benzoxazole ring, benzothiazole ring, 1H-benzotriazole ring, quinoline ring, isoquinoline ring, cinnoline ring, quinazoline ring, quinoxaline ring, phthalazine ring, naphthyridine ring, purine ring, pteridine ring, carbazole ring, acridine ring, phenoxathiin ring, phenoxazine ring, phenothiazine ring, phenazine ring, phenazasiline ring, indolizine ring, furan ring, benzofuran ring, isobenzofuran ring, dibenzofuran ring, thiophene ring, benzothiophene ring, dibenzothiophene ring, furazan ring, thianthrene ring, indolocarbazole ring, benzindolocarbazole ring, benzo-benzoindolocarbazole ring, naphthobenzofuran ring, dioxin ring, dihydroacridine ring, xanthene ring, thioxanthene ring, dibenzodioxin ring, dibenzazepine ring, tribenzazepine ring, iminobenzylidene ring, etc. In addition, in the dihydroacridine ring, xanthene ring, and thioxanthene ring, it is also preferable that two of the two hydrogens of the methylene group are each substituted with an alkyl group such as a methyl group which is a first substituent described later to form a dimethyldihydroacridine ring, dimethylxanthene ring, dimethylthioxanthene ring, etc. In addition, a bipyridine ring, phenylpyridine ring, pyridylphenyl ring which are bicyclic systems, and a terpyridine ring, bipyridylphenyl ring, pyridylbiphenyl ring which are tricyclic systems can also be cited as "heteroaryl rings". In addition, a pyran ring is also included in the "heteroaryl ring".

[0084] When at least one hydrogen in the aryl ring or heteroaryl ring is substituted with a substituent, the substituent is preferably a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, a substituted or unsubstituted diarylamino group, a substituted or unsubstituted diheteroarylamino group, a substituted or unsubstituted arylheteroarylamino group (an amino group having an aryl group and a heteroaryl group), a substituted or unsubstituted diarylboron group (two aryl groups can be bonded via a single bond or a linking group), a substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted aryloxy group, a substituted silyl group, a cyano group, a halogen, or -L-Ak. As the substituent when these groups have a substituent, the following can be cited: an aryl group, a heteroaryl group, an alkyl group, a cycloalkyl group, a cyano group, a halogen, or a diarylamino group.

[0085] The "halogen" includes fluorine, chlorine, bromine, or iodine, and is preferably fluorine. Hereinafter, "halogen" is used with the same meaning.

[0086] At least one hydrogen in the "aryl ring" or "heteroaryl ring" may be substituted by a substituted or unsubstituted "aryl", a substituted or unsubstituted "heteroaryl", a substituted or unsubstituted "diaryl amino", a substituted or unsubstituted "diheteroaryl amino", a substituted or unsubstituted "aryl heteroaryl amino", a substituted or unsubstituted "diaryl boron group (the two aryl groups may be bonded via a single bond or a linking group)", a substituted or unsubstituted "alkyl", a substituted or unsubstituted "cycloalkyl", a substituted or unsubstituted "alkoxy", a substituted or unsubstituted "aryloxy", a substituted "silyl", or -L-Ak. Regarding the "aryl" or "heteroaryl", the aryl of "diaryl amino", the heteroaryl of "diheteroaryl amino", the aryl and heteroaryl of "aryl heteroaryl amino", the aryl of "diaryl boron group", and the aryl of "aryloxy" as the first substituent, a monovalent group of the "aryl ring" or "heteroaryl ring" can be cited.

[0087] Specifically, as the "aryl", for example, an aryl having 6 to 30 carbon atoms can be cited, preferably an aryl having 6 to 24 carbon atoms, more preferably an aryl having 6 to 20 carbon atoms, further preferably an aryl having 6 to 16 carbon atoms, particularly preferably an aryl having 6 to 12 carbon atoms, and most preferably an aryl having 6 to 10 carbon atoms.

[0088] As specific aryls, for example, the following can be cited: phenyl which is a monocyclic aryl, (2-, 3-, 4-) biphenyl which is a bicyclic aryl, (1-, 2-) naphthyl, (2-, 3-, 4-, 5-, 6-, 7-) indenyl which are condensed bicyclic aryls, terphenyl (m-terphenyl-2'-yl, m-terphenyl-4'-yl, m-terphenyl-5'-yl, o-terphenyl-3'-yl, o-terphenyl-4'-yl, p-terphenyl-2'-yl, m-terphenyl-2-yl, m-terphenyl-3-yl, m-terphenyl-4-yl, o-terphenyl-2-yl, o-terphenyl-3-yl, o-terphenyl-4-yl, p-terphenyl-2-yl, p-terphenyl-3-yl, p-terphenyl-4-yl) which is a tricyclic aryl, acenaphthylene-(1-, 3-, 4-, 5-)yl, fluorene-(1-, 2-, 3-, 4-, 9-)yl, phenalene-(1-, 2-)yl, (1-, 2-, 3-, 4-, 9-) phenanthryl which are condensed tricyclic aryls, tetraphenyl (5'-phenyl-m-terphenyl-2-yl, 5'-phenyl-m-terphenyl-3-yl, 5'-phenyl-m-terphenyl-4-yl, m-tetraphenyl) which is a tetracyclic aryl, triphenylene-(1-, 2-)yl, pyrene-(1-, 2-, 4-)yl, tetracene-(1-, 2-, 5-)yl which are condensed tetracyclic aryls, perylene-(1-, 2-, 3-)yl, pentacene-(1-, 2-, 5-, 6-)yl and the like which are condensed pentacyclic aryls.

[0089] In addition, as the "heteroaryl", heteroaryls having 2 to 30 carbon atoms can be exemplified, preferably heteroaryls having 2 to 25 carbon atoms, more preferably heteroaryls having 2 to 20 carbon atoms, still more preferably heteroaryls having 2 to 15 carbon atoms, and particularly preferably heteroaryls having 2 to 10 carbon atoms. In addition, as the heteroaryl, for example, heterocycles containing 1 to 5 heteroatoms selected from oxygen, sulfur, and nitrogen as ring-constituting atoms in addition to carbon can be exemplified.

[0090] As specific heteroaryls, for example, the following can be exemplified: furyl, thienyl, pyrrolyl, oxazolyl, isoxazolyl, thiazolyl, isothiazolyl, imidazolyl, pyrazolyl, oxadiazolyl, furazanyl, thiadiazolyl, triazolyl, tetrazolyl, pyridyl, pyrimidinyl, pyridazinyl, pyrazinyl, triazinyl, benzofuryl, isobenzofuryl, dibenzofuryl, benzo[b]thienyl, dibenzothienyl, indolyl, isoindolyl, 1H-indazolyl, benzimidazolyl, benzoxazolyl, benzothiazolyl, 1H-benzotriazolyl, quinolinyl, isoquinolinyl, cinnolinyl, quinazolinyl, quinoxalinyl, phthalazinyl, naphthyridinyl, purinyl, pteridinyl, carbazolyl, acridinyl, phenoxazinyl, phenothiazinyl, phenazinyl, phenoxathiinyl, thianthrenyl, indolizinyl, etc.

[0091] In addition, regarding the "alkyl" as the first substituent, it can be either a straight-chain or a branched-chain, and for example, a straight-chain alkyl having 1 to 24 carbon atoms or a branched-chain alkyl having 3 to 24 carbon atoms can be exemplified. It is preferably an alkyl having 1 to 18 carbon atoms (a branched-chain alkyl having 3 to 18 carbon atoms), more preferably an alkyl having 1 to 12 carbon atoms (a branched-chain alkyl having 3 to 12 carbon atoms), still more preferably an alkyl having 1 to 8 carbon atoms (a branched-chain alkyl having 3 to 8 carbon atoms), particularly preferably an alkyl having 1 to 6 carbon atoms (a branched-chain alkyl having 3 to 6 carbon atoms), and most preferably an alkyl having 1 to 5 carbon atoms (a branched-chain alkyl having 3 to 5 carbon atoms).

[0092] As specific alkyls, the following can be exemplified: methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, isopentyl, neopentyl, tert-pentyl (t-pentyl) (t-amyl), n-hexyl, 1-methylpentyl, 4-methyl-2-pentyl, 3,3-dimethylbutyl, 2-ethylbutyl, n-heptyl, 1-methylhexyl, n-octyl, tert-octyl (1,1,3,3-tetramethylbutyl), 1-methylheptyl, 2-ethylhexyl, 2-propylpentyl, n-nonyl, 2,2-dimethylheptyl, 2,6-dimethyl-4-heptyl, 3,5,5-trimethylhexyl, n-decyl, n-undecyl, 1-methyldecyl, n-dodecyl, n-tridecyl, 1-hexylheptyl, n-tetradecyl, n-pentadecyl, n-hexadecyl, n-heptadecyl, n-octadecyl, n-eicosyl, etc.

[0093] In addition, for example, the following can be cited: 1-ethyl-1-methylpropyl, 1,1-diethylpropyl, 1,1-dimethylbutyl, 1-ethyl-1-methylbutyl, 1,1,4-trimethylpentyl, 1,1,2-trimethylpropyl, 1,1-dimethyloctyl, 1,1-dimethylpentyl, 1,1-dimethylheptyl, 1,1,5-trimethylhexyl, 1-ethyl-1-methylhexyl, 1-ethyl-1,3-dimethylbutyl, 1,1,2,2-tetramethylpropyl, 1-butyl-1-methylpentyl, 1,1-diethylbutyl, 1-ethyl-1-methylpentyl, 1,1,3-trimethylbutyl, 1-propyl-1-methylpentyl, 1,1,2-trimethylpropyl, 1-ethyl-1,2,2-trimethylpropyl, 1-propyl-1-methylbutyl, 1,1-dimethylhexyl, etc.

[0094] As a substituent when at least one hydrogen in the aryl ring or heteroaryl ring is substituted by a substituent, one of the particularly preferred substituents is a tertiary alkyl group represented by the following formula (tR) as a substituent containing the "alkyl". The reason is that by such a bulky substituent, the intermolecular distance increases, and thus the luminescence quantum yield (photoluminescence quantum yield, PLQY) is improved. In addition, it is also preferred that the tertiary alkyl group represented by the formula (tR) is a substituent that substitutes other substituents as the second substituent. Specifically, the following can be cited: a diarylamino group substituted by a tertiary alkyl group represented by (tR), a carbazolyl group (preferably an N-carbazolyl group) substituted by a tertiary alkyl group represented by (tR), or a benzocarbazolyl group (preferably an N-benzocarbazolyl group) substituted by a tertiary alkyl group represented by (tR). Regarding the "diarylamino group", the groups described as the following "first substituent" can be cited. As the substitution form of the group of the formula (tR) for the diarylamino group, the carbazolyl group, and the benzocarbazolyl group, examples in which part or all of the hydrogen in the aryl ring or benzene ring of these groups is substituted by the group of the formula (tR) can be cited.

[0095]

[0096] In the formula (tR), R a , R b and R c are each independently an alkyl group having 1 to 24 carbon atoms, and any -CH2- in the alkyl group can be substituted by -O-, and * is the bonding position.

[0097] As R a , R b and R cThe "alkyl group having 1 to 24 carbon atoms" can be either a straight-chain or a branched-chain one. For example, examples thereof include: a straight-chain alkyl group having 1 to 24 carbon atoms or a branched-chain alkyl group having 3 to 24 carbon atoms, an alkyl group having 1 to 18 carbon atoms (a branched-chain alkyl group having 3 to 18 carbon atoms), an alkyl group having 1 to 12 carbon atoms (a branched-chain alkyl group having 3 to 12 carbon atoms), an alkyl group having 1 to 6 carbon atoms (a branched-chain alkyl group having 3 to 6 carbon atoms), and an alkyl group having 1 to 4 carbon atoms (a branched-chain alkyl group having 3 to 4 carbon atoms).

[0098] R in formula (tR) a , R b and R c The total number of carbon atoms of is preferably 3 to 20 carbon atoms, and particularly preferably 3 to 10 carbon atoms.

[0099] As R a , R b and R c Specific examples of the alkyl group include: methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, isopentyl, neopentyl, tert-pentyl, n-hexyl, 1-methylpentyl, 4-methyl-2-pentyl, 3,3-dimethylbutyl, 2-ethylbutyl, n-heptyl, 1-methylhexyl, n-octyl, tert-octyl, 1-methylheptyl, 2-ethylhexyl, 2-propylpentyl, n-nonyl, 2,2-dimethylheptyl, 2,6-dimethyl-4-heptyl, 3,5,5-trimethylhexyl, n-decyl, n-undecyl, 1-methyldecyl, n-dodecyl, n-tridecyl, 1-hexylheptyl, n-tetradecyl, n-pentadecyl, n-hexadecyl, n-heptadecyl, n-octadecyl, n-eicosyl, etc.

[0100] Examples of the group represented by formula (tR) include: tert-butyl, tert-pentyl, 1-ethyl-1-methylpropyl, 1,1-diethylpropyl, 1,1-dimethylbutyl, 1-ethyl-1-methylbutyl, 1,1,3,3-tetramethylbutyl, 1,1,4-trimethylpentyl, 1,1,2-trimethylpropyl, 1,1-dimethyloctyl, 1,1-dimethylpentyl, 1,1-dimethylheptyl, 1,1,5-trimethylhexyl, 1-ethyl-1-methylhexyl, 1-ethyl-1,3-dimethylbutyl, 1,1,2,2-tetramethylpropyl, 1-butyl-1-methylpentyl, 1,1-diethylbutyl, 1-ethyl-1-methylpentyl, 1,1,3-trimethylbutyl, 1-propyl-1-methylpentyl, 1,1,2-trimethylpropyl, 1-ethyl-1,2,2-trimethylpropyl, 1-propyl-1-methylbutyl, 1,1-dimethylhexyl, etc. Among these, tert-butyl and tert-pentyl are preferred.

[0101] Regarding "cycloalkyl" as the first substituent, examples include: cycloalkyl having 3 to 24 carbon atoms, cycloalkyl having 3 to 20 carbon atoms, cycloalkyl having 3 to 16 carbon atoms, cycloalkyl having 3 to 14 carbon atoms, cycloalkyl having 5 to 10 carbon atoms, cycloalkyl having 5 to 8 carbon atoms, cycloalkyl having 5 to 6 carbon atoms, cycloalkyl having 5 carbon atoms, etc.

[0102] As specific cycloalkyls, examples include: cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl, and C1-C5 alkyl (especially methyl) substituents thereof, or norbornyl (bicyclo[2.2.1]heptyl), bicyclo[1.1.0]butyl, bicyclo[1.1.1]pentyl, bicyclo[2.1.0]pentyl, bicyclo[2.1.1]hexyl, bicyclo[3.1.0]hexyl, bicyclo[2.2.2]octyl, adamantyl, diamantyl, decahydronaphthyl, decahydroazulenyl, etc.

[0103] In addition, regarding "alkoxy" as the first substituent, for example, linear alkoxy having 1 to 24 carbon atoms or branched alkoxy having 3 to 24 carbon atoms can be cited. Preferred is alkoxy having 1 to 18 carbon atoms (branched alkoxy having 3 to 18 carbon atoms), more preferred is alkoxy having 1 to 12 carbon atoms (branched alkoxy having 3 to 12 carbon atoms), still more preferred is alkoxy having 1 to 6 carbon atoms (branched alkoxy having 3 to 6 carbon atoms), and particularly preferred is alkoxy having 1 to 5 carbon atoms (branched alkoxy having 3 to 5 carbon atoms).

[0104] As specific alkoxys, examples include: methoxy, ethoxy, propoxy, isopropoxy, butoxy, isobutoxy, sec-butoxy, tert-butoxy, tert-pentyloxy, pentyloxy, hexyloxy, heptyloxy, octyloxy, etc.

[0105] In addition, regarding "substituted silyl" as the first substituent, for example, silyl substituted with three substituents selected from the group consisting of alkyl, cycloalkyl, and aryl can be cited. Examples include: trialkylsilyl, tricycloalkylsilyl, dialkylcycloalkylsilyl, alkyl dicycloalkylsilyl, triarylsilyl, dialkylarylsilyl, and alkyldiarylsilyl.

[0106] As "trialkylsilyl", a group in which three hydrogens in silyl are independently substituted with alkyl can be cited, and the alkyl can refer to the group described as "alkyl" in the first substituent. Preferred alkyls for substitution are alkyls having 1 to 5 carbon atoms. Specifically, examples include: methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, tert-butyl, tert-pentyl, etc.

[0107] Examples of the specific trialkylsilyl group include: trimethylsilyl, triethylsilyl, tripropylsilyl, triisopropylsilyl, tributylsilyl, tri-sec-butylsilyl, tri-tert-butylsilyl, tri-tert-pentylsilyl, ethyldimethylsilyl, propyldimethylsilyl, isopropyldimethylsilyl, butyldimethylsilyl, sec-butyldimethylsilyl, tert-butyldimethylsilyl, tert-pentyldimethylsilyl, methyldiethylsilyl, propyldiethylsilyl, isopropyldiethylsilyl, butyldiethylsilyl, sec-butyldiethylsilyl, tert-butyldiethylsilyl, tert-pentyldiethylsilyl, methyldipropylsilyl, ethyldipropylsilyl, butyldipropylsilyl, sec-butyldipropylsilyl, tert-butyldipropylsilyl, tert-pentyldipropylsilyl, methyldiisopropylsilyl, ethyldiisopropylsilyl, butyldiisopropylsilyl, sec-butyldiisopropylsilyl, tert-butyldiisopropylsilyl, tert-pentyldiisopropylsilyl, etc.

[0108] Examples of the "tricycloalkylsilyl group" include groups in which three hydrogens in the silyl group are each independently substituted with a cycloalkyl group, and the cycloalkyl group may be the group described as the "cycloalkyl group" in the first substituent. Preferred cycloalkyl groups for substitution are cycloalkyl groups having 5 to 10 carbon atoms. Specifically, examples include: cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl, bicyclo[1.1.1]pentyl, bicyclo[2.1.0]pentyl, bicyclo[2.1.1]hexyl, bicyclo[3.1.0]hexyl, bicyclo[2.2.1]heptyl, bicyclo[2.2.2]octyl, adamantyl, decahydronaphthyl, decahydroazulenyl, etc.

[0109] Examples of the specific tricycloalkylsilyl group include tricyclopentylsilyl, tricyclohexylsilyl, etc.

[0110] Examples of the dialkylcycloalkylsilyl group substituted with two alkyl groups and one cycloalkyl group and the alkylbicycloalkylsilyl group substituted with one alkyl group and two cycloalkyl groups include silyl groups substituted with groups selected from the specific alkyl groups and cycloalkyl groups described above.

[0111] Examples of the dialkylarylsilyl group substituted with two alkyl groups and one aryl group, the alkyl diarylsilyl group substituted with one alkyl group and two aryl groups, and the triarylsilyl group substituted with three aryl groups include silyl groups substituted with groups selected from the specific alkyl groups and aryl groups described above. Specific examples of the triarylsilyl group include triphenylsilyl.

[0112] In addition, for the "aryl" in the "diarylboron group" as the first substituent, the description of the aryl can be cited. Further, the two aryl groups can be bonded via a single bond or a linking group (such as >C(-R)2, >O, >S, or >N-R). Here, R in >C(-R)2 and >N-R is aryl, heteroaryl, diarylamino, alkyl, cycloalkyl, alkoxy, or aryloxy (the above are the first substituents), and the aryl, heteroaryl, alkyl, or cycloalkyl (the above are the second substituents) can be further substituted in the first substituent. As specific examples of these groups, the description of the aryl, heteroaryl, diarylamino, alkyl, cycloalkyl, alkoxy, or aryloxy as the first substituent can be cited.

[0113] In -L-Ak of the first substituent, L is >N-R, >O, or >S, and R in >N-R is optionally substituted aryl, optionally substituted heteroaryl, optionally substituted alkyl, or optionally substituted cycloalkyl. Further, R in >N-R can be bonded to Ak via a linking group or a single bond.

[0114] Ak is hydrogen, optionally substituted alkyl, or optionally substituted cycloalkyl, at least one hydrogen in the alkyl and cycloalkyl can be substituted, and at least one -CH2- in the alkyl and cycloalkyl can be substituted by -O- and -S-.

[0115] L is preferably >N-R.

[0116] When L is >N-R, R is preferably aryl substituted by alkyl or cycloalkyl, heteroaryl substituted by alkyl or cycloalkyl, alkyl, or cycloalkyl, more preferably aryl substituted by alkyl, heteroaryl substituted by alkyl, alkyl, or cycloalkyl, still more preferably aryl substituted by alkyl, and particularly preferably phenyl substituted by methyl.

[0117] Ak is preferably alkyl having 1 to 6 carbon atoms or cycloalkyl having 3 to 14 carbon atoms, and is preferably alkyl having 1 to 4 carbon atoms or cycloalkyl having 3 to 8 carbon atoms, more preferably alkyl having 1 to 4 carbon atoms, and still more preferably methyl.

[0118] When L is >N-R, R can be bonded to Ak via a linking group or a single bond. Examples of the linking group at this time include: >O, >S, or >Si(-R)2, etc. R in >Si(-R)2 is hydrogen, aryl having 6 to 12 carbon atoms, alkyl having 1 to 6 carbon atoms, or cycloalkyl having 3 to 14 carbon atoms. Examples of the structure in which R in >N-R is bonded to Ak via a linking group or a single bond are as follows.

[0119]

[0120] In the above formulas, Me is methyl and is bonded to the ring-forming atom of the aryl ring or heteroaryl ring in ring A, ring B, ring C, ring D, or ring E at the position of *.

[0121] A substituted or unsubstituted "aryl", a substituted or unsubstituted "heteroaryl", a substituted or unsubstituted "diaryl amino", a substituted or unsubstituted "diheteroaryl amino", a substituted or unsubstituted "aryl heteroaryl amino", a substituted or unsubstituted "diaryl boron group (the two aryl groups may be bonded via a single bond or a linking group)", a substituted or unsubstituted "alkyl", a substituted or unsubstituted "cycloalkyl", a substituted or unsubstituted "alkoxy", a substituted or unsubstituted "aryloxy", or a substituted "silyl group", as described as being substituted or unsubstituted, at least one hydrogen thereof may be substituted by a second substituent. As the second substituent, for example, aryl, heteroaryl, alkyl, or cycloalkyl can be cited, and specific examples thereof can be referred to the description of the monovalent group of the "aryl ring" or "heteroaryl ring" and the "alkyl" or "cycloalkyl" as the first substituent. In addition, in the aryl or heteroaryl as the second substituent, a structure in which at least one hydrogen thereof is substituted by an aryl such as phenyl (specific examples are the groups described above), an alkyl such as methyl or tert-butyl (specific examples are the groups described above), or a cycloalkyl such as cyclohexyl (specific examples are the groups described above) is also included in the aryl or heteroaryl as the second substituent. As an example, when the second substituent is a carbazolyl group, a carbazolyl group in which at least one hydrogen at the 9-position is substituted by an aryl such as phenyl, an alkyl such as methyl, or a cycloalkyl such as cyclohexyl is also included in the heteroaryl as the second substituent.

[0122] The emission wavelength can be adjusted by the steric hindrance, electron-donating property, and electron-withdrawing property of the structure of the first substituent. Preferably, it is a group represented by the following structural formula, more preferably methyl, tert-butyl, tert-amyl, tert-octyl, neopentyl, adamantyl, phenyl, o-tolyl, p-tolyl, 2,4-xylyl, 2,5-xylyl, 2,6-xylyl, 2,4,6-mesityl, diphenylamino, di-p-tolylamino, bis(p-(tert-butyl)phenyl)amino, carbazolyl (especially N-carbazolyl), 3,6-dimethylcarbazolyl, 3,6-di-tert-butylcarbazolyl, and phenoxy, and still more preferably methyl, tert-butyl, tert-amyl, tert-octyl, neopentyl, adamantyl, phenyl, o-tolyl, 2,6-xylyl, 2,4,6-mesityl, diphenylamino, di-p-tolylamino, bis(p-(tert-butyl)phenyl)amino, carbazolyl, 3,6-dimethylcarbazolyl, and 3,6-di-tert-butylcarbazolyl. From the viewpoint of ease of synthesis, a group with large steric hindrance is preferred because of selective synthesis. Specifically, preferred are tert-butyl, tert-amyl, tert-octyl, adamantyl, o-tolyl, p-tolyl, 2,4-xylyl, 2,5-xylyl, 2,6-xylyl, 2,4,6-mesityl, di-p-tolylamino, bis(p-(tert-butyl)phenyl)amino, 3,6-dimethylcarbazolyl, and 3,6-di-tert-butylcarbazolyl.

[0123] In the following structural formula, "Me" represents methyl, "tBu" represents tert-butyl, "tAm" represents tert-amyl, "tOct" represents tert-octyl, and * represents the bonding position.

[0124]

[0125]

[0126]

[0127]

[0128]

[0129]

[0130]

[0131]

[0132]

[0133]

[0134]

[0135] When two or three hydrogens bonded to consecutive (adjacent) carbon atoms are substituted, the substituent may be a group represented by formula (A20).

[0136]

[0137] In formula (A20), L S is >N-R, >O, >Si(-R)2 or >S, where R in >N-R is a substituted aryl, a substituted heteroaryl, a substituted alkyl or a substituted cycloalkyl, R in >Si(-R)2 is hydrogen, a substituted aryl, a substituted alkyl or a substituted cycloalkyl, and they may be bonded to each other to form a ring. Additionally, at least one of R in >N-R and R in >Si(-R)2 may be bonded to at least one selected from the group consisting of ring A, ring B, ring C, ring D, ring E and R S through a linking group or a single bond.

[0138] r is an integer from 1 to 4.

[0139] R S are each independently hydrogen, a substituted alkyl or a substituted cycloalkyl, and any R S may be bonded to another arbitrary R S through a linking group or a single bond and bond to each other.

[0140] The group represented by formula (A20) is bonded to two adjacent atoms on the ring of an aryl ring, a heteroaryl ring, or a cycloalkane ring at the two * positions respectively.

[0141] When the group represented by formula (A20) is included in the polycyclic aromatic compound represented by formula (1), the number of such groups is preferably one or two. The group represented by formula (A20) may be a substituent in any one of ring A, ring B, ring C, ring D, and ring E.

[0142] The group represented by formula (A20) is bonded to two adjacent atoms on the ring of an aryl ring or a heteroaryl ring at the two * positions respectively. The group represented by formula (A20) is preferably bonded to two adjacent atoms on an aryl ring or a heteroaryl ring at the two * positions respectively. At this time, the two adjacent atoms on the ring are preferably both carbon atoms. By bonding the group represented by formula (A20) to an aryl ring or a heteroaryl ring, a condensed ring structure is formed. For the compound represented by formula (1) having the condensed ring structure, the compound becomes a more rigid structure. If it becomes rigid, it is expected to suppress the vibration of the molecule, the external quantum efficiency (EQE) is improved, the stability of the molecule is increased, and the device lifetime becomes longer.

[0143] In formula (A20), L Sis >N-R, >O, >Si(-R)2 or >S. By selecting the kind of L in the group represented by formula (A20) S , the HOMO and LUMO of the compound of the present invention can be controlled. When L S is N-R, >O or >S, the HOMO and LUMO become shallower. When L S is Si, the HOMO and LUMO become deeper. If the HOMO and LUMO become shallower, it is expected that the triplet-triplet fusion (TTF) element using the compound will have a long lifetime, high efficiency and low driving voltage. On the other hand, if the HOMO and LUMO become deeper, it is expected that the hole trapping property of the dopant will disappear and the driving voltage will be significantly lowered.

[0144] As L in formula (A20) S , the R of >N-R is a substituted aryl, a substituted heteroaryl, a substituted alkyl or a substituted cycloalkyl. As L in formula (A20) S , the R of >Si(-R)2 is hydrogen, a substituted aryl, a substituted alkyl or a substituted cycloalkyl, and the two Rs may be bonded to each other to form a ring. In addition, at least one of the Rs of the >N-R and the >Si(-R)2 may be bonded to at least one selected from the group consisting of ring A, ring B, ring C, ring D, ring E and R S through a linking group or a single bond. L is preferably >N-R, >O or >S, more preferably >N-R or >O, and still more preferably >N-R.

[0145] L S When L is >N-R, R is preferably an aryl substituted with an alkyl or a cycloalkyl, a heteroaryl substituted with an alkyl or a cycloalkyl, an alkyl or a cycloalkyl, more preferably an aryl substituted with an alkyl or a cycloalkyl, or a heteroaryl substituted with an alkyl or a cycloalkyl, and still more preferably an aryl substituted with an alkyl or a cycloalkyl, and particularly preferably a phenyl substituted with an alkyl or a cycloalkyl.

[0146] In formula (A20), r is an integer of 1 to 4, preferably 2 or 3, and more preferably 2.

[0147] In formula (A20), R S are each independently hydrogen, a substituted alkyl or a substituted cycloalkyl, and any R S may be linked to another arbitrary R S to each other through a linking group or a single bond.

[0148] R SPreferably, any two are bonded to each other through a linking group or a single bond. Examples of the linking group include >O, >S, etc. Examples of the divalent group formed by bonding to each other include an alkylene group. At least one hydrogen in the alkylene group may be substituted with an alkyl group or a cycloalkyl group, and at least one (preferably one) -CH2- in the alkylene group may be substituted with -O- and -S-. As the divalent group formed by bonding to each other, a linear alkylene group having 2 to 5 carbon atoms is preferred, a linear alkylene group having 3 or 4 carbon atoms is more preferred, and a linear alkylene group having 4 carbon atoms (-(CH2)4-) is even more preferred. The linear alkylene group having 4 carbon atoms (-(CH2)4-) is particularly preferably unsubstituted.

[0149] When two Rs bonded to adjacent carbon atoms respectively S are bonded to each other through a linking group or a single bond, the remaining Rs not participating in the bonding S are each independently preferably hydrogen or a substitutable alkyl group, or bonded to the R of >N-R or >Si(-R)2 as L S .

[0150] When two Rs bonded to adjacent carbon atoms respectively S are bonded to each other through a linking group or a single bond, regarding the substitutable alkyl group as the remaining R not participating in the bonding S it is more preferably a substitutable alkyl group having 1 to 6 carbon atoms, even more preferably an unsubstituted alkyl group having 1 to 6 carbon atoms, and most preferably all are methyl groups.

[0151] That is, as a preferred example of the group represented by formula (A20), the group represented by formula (A20-a) can be cited.

[0152]

[0153] In the formula, Me is a methyl group.

[0154] As L S at least one of the Rs of >N-R and >Si(-R)2 can be bonded to at least one selected from the group consisting of ring A, ring B, ring C, ring D, ring E, and R S through a linking group or a single bond. As an example when L S is >N-R, the groups represented by any of the following formulas can be cited, and preferably the group represented by formula (A20-b-1).

[0155]

[0156] In each formula, Me is a methyl group. In each formula, at * it is bonded to two or three atoms consecutive (adjacent) on the ring of an aryl ring, heteroaryl ring, or cycloalkane ring of any one of ring A, ring B, ring C, ring D, and ring E.

[0157] In formula (1), each L is independently a single bond, >O, >N-R NX , >C(-R CX )2, -C(-R CX )=C(-R CX )-, >Si(-R IX )2, >S, >CO, >CS, >SO, >SO2, >SeO, >SeO2, >PO, >B(-R PX ) or >Se, and each R NX , R CX , R IX and R PX is independently hydrogen, a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted cycloalkyl group, and the two Rs CX may be bonded to each other to form a ring, and the two Rs IX may be bonded to each other to form a ring.

[0158] In formula (1), in the structure, at least one selected from the group consisting of an aryl ring and a heteroaryl ring may be condensed with at least one cycloalkane, the cycloalkane may be substituted with at least one substituent, and at least one -CH2- in the cycloalkane may be substituted with -O-.

[0159] Examples of the "cycloalkane" include cycloalkanes having 3 to 24 carbon atoms, cycloalkanes having 3 to 20 carbon atoms, cycloalkanes having 3 to 16 carbon atoms, cycloalkanes having 3 to 14 carbon atoms, cycloalkanes having 5 to 10 carbon atoms, cycloalkanes having 5 to 8 carbon atoms, cycloalkanes having 5 to 6 carbon atoms, cycloalkanes having 5 carbon atoms, etc.

[0160] Specific examples of the cycloalkane include cyclopropane, cyclobutane, cyclopentane, cyclohexane, cycloheptane, cyclooctane, cyclononane, cyclodecane, norbornane (bicyclo[2.2.1]heptane), bicyclo[1.1.0]butane, bicyclo[1.1.1]pentane, bicyclo[2.1.0]pentane, bicyclo[2.1.1]hexane, bicyclo[3.1.0]hexane, bicyclo[2.2.1]heptane, bicyclo[2.2.2]octane, adamantane, diamantane, decahydronaphthalene, decahydroazulene, and C1-C5 alkyl (especially methyl) substituents, halogen (especially fluorine) substituents, and deuterium substituents thereof, etc.

[0161] Among these, a structure in which at least one hydrogen on the carbon at the α-position of the cycloalkane (in the cycloalkyl group condensed with an aryl ring or a heteroaryl ring, the carbon at the position adjacent to the carbon at the condensation site) is substituted is preferred, a structure in which two hydrogens on the carbon at the α-position are substituted is more preferred, and a structure in which a total of four hydrogens on two α-positions are substituted is further preferred. Examples of the substituent include an alkyl group having 1 to 5 carbon atoms (especially a methyl group) substituent, a halogen (especially fluorine) substituent, and a deuterium substituent. A structure in which a partial structure represented by the following formula (B10) is bonded to adjacent carbon atoms in the aryl ring or heteroaryl ring is particularly preferred.

[0162]

[0163] In formula (B10), Me represents a methyl group, and * represents the bonding position.

[0164] In formula (1), at least one of ring A, ring B, ring C, ring D, and ring E has the group represented by formula (2) as a substituent. Formula (2) will be specifically described below.

[0165] In formula (1), at least one hydrogen may be substituted with deuterium, a cyano group, or a halogen, at least one nitrogen may be substituted with nitrogen-15 ( 15 N), at least one sulfur may be substituted with sulfur-33 ( 33 S), sulfur-34 ( 34 S), or sulfur-36 ( 36 S), at least one oxygen may be substituted with oxygen-17 ( 17 O) or oxygen-18 ( 18 O), at least one carbon may be substituted with carbon-13 ( 13 C), and at least one boron may be substituted with boron-11 ( 11 B).

[0166] <Explanation of formula (1')>

[0167]

[0168] Formula (1) can be represented by formula (1').

[0169] In formula (1'), L has the same definition as L in formula (1).

[0170] In formula (1'), Z is independently -C(-R ZE )= or -N=, where at least one of Z is -N=.

[0171] The R ZEEach is independently selected from the group consisting of hydrogen, deuterium, halogen, cyano, nitro, substituted or unsubstituted silyl, substituted or unsubstituted amino, substituted or unsubstituted alkyl having 1 to 10 carbon atoms, substituted or unsubstituted cycloalkyl having 3 to 30 carbon atoms, substituted or unsubstituted aryl having 6 to 30 carbon atoms, substituted or unsubstituted heteroaryl having 2 to 30 carbon atoms, and the group represented by formula (2'), wherein substituents substituted on adjacent atoms may be bonded to each other to form a ring.

[0172] Among them, at least one of R ZE has the group represented by the following formula (2').

[0173]

[0174] In formula (2'), R has the same definition as R in formula (2), and * represents the bonding position with R ZE .

[0175] The formula (1') can be represented by any one of the following chemical formulas (1'-1) to (1'-7):

[0176]

[0177] In the chemical formulas (1'-1) to (1'-7), L has the same definition as L in formula (1), and at least one has the group represented by formula (2) as a substituent.

[0178] <Description of formula (1")>

[0179]

[0180] The formula (1) can be represented by the formula (1").

[0181] In formula (1"), Z has the same definition as in formula (1').

[0182] The formula (1") can be represented by any one of the following chemical formulas (1"-1) to (1"-7):

[0183]

[0184] In the chemical formulas (1"-1) to (1"-7), at least one has the group represented by formula (2) as a substituent.

[0185] The formula (1") can be represented by any one of chemical formulas (1"-1) to (1"-4), chemical formula (1"-6), and chemical formula (1"-7).

[0186] <Description of formula (2)>

[0187] In formula (1), at least one of ring A, ring B, ring C, ring D and ring E has a group represented by formula (2) as a substituent.

[0188]

[0189] In formula (2), * represents the bonding position to an aryl ring or a heteroaryl ring.

[0190] In formula (2), ring F is a substituted or unsubstituted aryl ring, or a substituted or unsubstituted heteroaryl ring.

[0191] In formula (2), R is a substituted or unsubstituted aryl ring, a substituted or unsubstituted heteroaryl ring, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted cycloalkyl group.

[0192] In formula (2), as the "aryl ring" of ring F, for example, an aryl ring having 6 to 30 carbon atoms can be exemplified, preferably an aryl ring having 6 to 16 carbon atoms, more preferably an aryl ring having 6 to 12 carbon atoms, and particularly preferably an aryl ring having 6 to 10 carbon atoms.

[0193] In formula (2), as the "heteroaryl ring" of ring F, for example, a heteroaryl ring having 2 to 30 carbon atoms can be exemplified, preferably a heteroaryl ring having 2 to 25 carbon atoms, more preferably a heteroaryl ring having 2 to 20 carbon atoms, further preferably a heteroaryl ring having 2 to 15 carbon atoms, and particularly preferably a heteroaryl ring having 2 to 10 carbon atoms. In addition, as the "heteroaryl ring", for example, a heterocycle containing 1 to 5 heteroatoms selected from oxygen, sulfur and nitrogen as ring-constituting atoms in addition to carbon can be exemplified.

[0194] In ring F, the aryl ring can be selected from the group consisting of a benzene ring, a biphenyl ring, a terphenyl ring, an indene ring, a naphthalene ring, a fluorene ring, an anthracene ring and a phenanthrene ring, and the heteroaryl ring can be selected from the group consisting of a benzofuran ring, a benzothiophene ring, an indole ring, a dibenzofuran ring, a dibenzothiophene ring, a carbazole ring, a naphthofuran ring, a naphthothiophene ring, a benzoindole ring and a benzoselenophene ring. Ring F is preferably a substituted or unsubstituted benzene ring, a substituted or unsubstituted biphenyl ring, a substituted or unsubstituted terphenyl ring, a substituted or unsubstituted benzothiophene ring, or a substituted or unsubstituted benzofuran ring.

[0195] When at least one hydrogen in the aryl ring or heteroaryl ring is substituted by a substituent, the substituent is preferably a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted diarylamino, a substituted or unsubstituted diheteroarylamino, a substituted or unsubstituted arylheteroarylamino (amino having an aryl and a heteroaryl), a substituted or unsubstituted diarylboron group (two aryls may be bonded by a single bond or a linking group), a substituted or unsubstituted alkyl, a substituted or unsubstituted cycloalkyl, a substituted or unsubstituted alkoxy, a substituted or unsubstituted aryloxy, a substituted silyl, a cyano group, a halogen, or -L-Ak. As substituents when these groups have substituents, examples include: an aryl, a heteroaryl, an alkyl, a cycloalkyl, a cyano group, a halogen, or a diarylamino.

[0196] In formula (2), the "aryl ring" and "heteroaryl ring" of R have the same definitions as the "aryl ring" and "heteroaryl ring" in the F ring described above.

[0197] In formula (2), the "alkyl" as R can be either a straight-chain or a branched-chain one. For example, a straight-chain alkyl having 1 to 24 carbon atoms or a branched-chain alkyl having 3 to 24 carbon atoms can be cited. Preferably, it is an alkyl having 1 to 18 carbon atoms (a branched-chain alkyl having 3 to 18 carbon atoms), more preferably an alkyl having 1 to 12 carbon atoms (a branched-chain alkyl having 3 to 12 carbon atoms), still more preferably an alkyl having 1 to 8 carbon atoms (a branched-chain alkyl having 3 to 8 carbon atoms), particularly preferably an alkyl having 1 to 6 carbon atoms (a branched-chain alkyl having 3 to 6 carbon atoms), and most preferably an alkyl having 1 to 5 carbon atoms (a branched-chain alkyl having 3 to 5 carbon atoms).

[0198] As specific alkyls, examples include: methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, isopentyl, neopentyl, tert-pentyl (t-pentyl) (t-amyl), n-hexyl, 1-methylpentyl, 4-methyl-2-pentyl, 3,3-dimethylbutyl, 2-ethylbutyl, n-heptyl, 1-methylhexyl, n-octyl, tert-octyl (1,1,3,3-tetramethylbutyl), 1-methylheptyl, 2-ethylhexyl, 2-propylpentyl, n-nonyl, 2,2-dimethylheptyl, 2,6-dimethyl-4-heptyl, 3,5,5-trimethylhexyl, n-decyl, n-undecyl, 1-methyldecyl, n-dodecyl, n-tridecyl, 1-hexylheptyl, n-tetradecyl, n-pentadecyl, n-hexadecyl, n-heptadecyl, n-octadecyl, n-eicosyl, etc.

[0199] In addition, for example, the following can be cited: 1-ethyl-1-methylpropyl, 1,1-diethylpropyl, 1,1-dimethylbutyl, 1-ethyl-1-methylbutyl, 1,1,4-trimethylpentyl, 1,1,2-trimethylpropyl, 1,1-dimethyloctyl, 1,1-dimethylpentyl, 1,1-dimethylheptyl, 1,1,5-trimethylhexyl, 1-ethyl-1-methylhexyl, 1-ethyl-1,3-dimethylbutyl, 1,1,2,2-tetramethylpropyl, 1-butyl-1-methylpentyl, 1,1-diethylbutyl, 1-ethyl-1-methylpentyl, 1,1,3-trimethylbutyl, 1-propyl-1-methylpentyl, 1,1,2-trimethylpropyl, 1-ethyl-1,2,2-trimethylpropyl, 1-propyl-1-methylbutyl, 1,1-dimethylhexyl, etc.

[0200] In formula (2), examples of the "cycloalkyl group" as R include: cycloalkyl groups having 3 to 24 carbon atoms, cycloalkyl groups having 3 to 20 carbon atoms, cycloalkyl groups having 3 to 16 carbon atoms, cycloalkyl groups having 3 to 14 carbon atoms, cycloalkyl groups having 5 to 10 carbon atoms, cycloalkyl groups having 5 to 8 carbon atoms, cycloalkyl groups having 5 to 6 carbon atoms, cycloalkyl groups having 5 carbon atoms, etc.

[0201] Specific examples of the cycloalkyl group include: cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl, and alkyl (especially methyl) substituents having 1 to 5 carbon atoms of these, or norbornyl (bicyclo[2.2.1]heptyl), bicyclo[1.1.0]butyl, bicyclo[1.1.1]pentyl, bicyclo[2.1.0]pentyl, bicyclo[2.1.1]hexyl, bicyclo[3.1.0]hexyl, bicyclo[2.2.2]octyl, adamantyl, diamantyl, decahydronaphthyl, decahydroazulenyl, etc.

[0202] In the said formula (2), at least one hydrogen can be substituted by deuterium, cyano or halogen, at least one nitrogen can be substituted by nitrogen-15 ( 15 N), at least one sulfur can be substituted by sulfur-33 ( 33 S), sulfur-34 ( 34 S) or sulfur-36 ( 36 S), at least one oxygen can be substituted by oxygen-17 ( 17 O) or oxygen-18 ( 18 O), at least one carbon can be substituted by carbon-13 ( 13 C), at least one boron can be substituted by boron-11 ( 11 B).

[0203] The said formula (2) can be represented by any one of the following chemical formulas (2-1) to chemical formula (2-7):

[0204]

[0205] In Chemical Formulas (2-1) to (2-7), * represents the bonding position to an aryl ring or a heteroaryl ring.

[0206] <Replacement with deuterium>

[0207] In the polycyclic aromatic compound containing the structural unit represented by Formula (1), all or part of the hydrogen may be deuterium. The same applies to the polycyclic aromatic compounds represented by Formula (1') or Formula (1").

[0208] For example, the hydrogen in the aryl ring or heteroaryl ring of Ring A, Ring B, Ring C, Ring D, Ring E, or Ring F, and the hydrogen in their substituents can be replaced by deuterium. Examples include the form in which all or part of the hydrogen in the aryl or heteroaryl among them is replaced by deuterium. In addition, from the perspective of durability, it is also preferable that all or part of the hydrogen in the polycyclic aromatic compound containing the structural unit represented by Formula (1) is deuterated.

[0209] <Specific examples of polycyclic aromatic compounds>

[0210] As an example of the polycyclic aromatic compound containing the structural unit represented by Formula (1), a compound represented by any of the following structural formulas can be cited. In addition, "Me" in the following structural formulas represents a methyl group, "tBu" represents a tert-butyl group, and "D" represents deuterium.

[0211]

[0212]

[0213]

[0214]

[0215]

[0216]

[0217]

[0218]

[0219]

[0220]

[0221]

[0222]

[0223]

[0224]

[0225]

[0226]

[0227]

[0228]

[0229]

[0230]

[0231]

[0232]

[0233] As an example of the structural unit represented by the formula (2), a group represented by any of the following structural formulas can be cited:

[0234]

[0235]

[0236] 1-2. Reactive compound, polymer compound, polymer crosslink, pendant polymer compound, pendant polymer crosslink

[0237] The polycyclic aromatic compound represented by the formula (1) can also be used as the following polymer compound (the monomer for obtaining the polymer compound has a polymerizable substituent) or polymer crosslink (the polymer compound for obtaining the polymer crosslink has a crosslinkable substituent), or the following pendant polymer compound (the reactive compound for obtaining the pendant polymer compound has a reactive substituent) or pendant polymer crosslink (the pendant polymer compound for obtaining the pendant polymer crosslink has a crosslinkable substituent) for materials for organic devices, such as materials for organic electroluminescent elements, materials for organic field-effect transistors, or materials for organic thin-film solar cells. Here, the polymer compound is obtained by polymerizing a reactive compound having a reactive substituent substituted in each of the polycyclic aromatic compounds as a monomer, the polymer crosslink is obtained by further crosslinking the polymer compound, the pendant polymer compound is obtained by reacting a main-chain polymer with the reactive compound, and the pendant polymer crosslink is obtained by further crosslinking the pendant polymer compound.

[0238] In addition, in this specification, the "high molecular compound" refers to a polymer having a molecular weight distribution and an average molecular weight of polystyrene sulfonic acid of 1×10 3 ~1×10 8 (1×10^3 to 1×10^8). The average molecular weight (Mn) of polystyrene sulfonic acid of the high molecular compound is measured using tetrahydrofuran as the mobile phase, and can be determined by size exclusion chromatography (SEC). Specifically, the measured high molecular compound is dissolved in tetrahydrofuran at a concentration of about 0.05% by mass, and 10 μL is injected into the SEC. The flow rate of the mobile phase is 1.0 mL / min, and PLgel MIXED_B (manufactured by Polymer Laboratories) is used as the chromatography column. A UV-VIS detector (manufactured by Tosoh Corporation, product name: UV-8320GPC) can be used as the detector.

[0239] The average molecular weight of the high molecular compound of the present invention is preferably 2000 to 1×10 8 and more preferably 5000 to 1×10 8 .

[0240] As the reactive substituent (including the polymerizable substituent, the crosslinkable substituent, and the reactive substituent for obtaining a pendant polymer, hereinafter also simply referred to as "reactive substituent"), as long as it is a substituent that can polymerize the polycyclic aromatic compound, a substituent that can further crosslink the high molecular compound obtained in this way, and a substituent that can undergo a pendant reaction in the main-chain polymer, there is no particular limitation, and examples thereof include alkenyl, alkynyl, unsaturated bodies of cycloalkyl (such as cyclobutenyl), groups in which at least one -CH2- in cycloalkyl is substituted with -O- (such as epoxy group), unsaturated bodies of condensed cycloalkanes (such as condensed cyclobutene), etc., and substituents having the following structures are preferred. * in each structural formula represents the bonding position.

[0241]

[0242] L is independently a single bond, -O-, -S-, >C=O, -O-C(=O)-, alkylene having 1 to 12 carbon atoms, oxyalkylene having 1 to 12 carbon atoms, and polyoxyalkylene having 1 to 12 carbon atoms. Among the substituents, groups represented by formula (XLS-1), formula (XLS-2), formula (XLS-3), formula (XLS-9), formula (XLS-10), or formula (XLS-17) are preferred, and groups represented by formula (XLS-1), formula (XLS-3), or formula (XLS-17) are more preferred.

[0243] Details of the uses of such a polymer compound, a polymer crosslinking body, a pendant polymer compound, and a pendant polymer crosslinking body (hereinafter, also simply referred to as "polymer compound and polymer crosslinking body") will be described later.

[0244] 2. Preparation method of polycyclic aromatic compound

[0245] The method for preparing a polycyclic aromatic compound containing the structure represented by formula (1) is basically carried out by bonding the A ring, B ring, and C ring linked to boron through a bonding group (>N) and linking them to the D ring and E ring.

[0246] In the first reaction, for example, in the case of an etherification reaction, general reactions such as nucleophilic substitution reactions and Ullmann reactions can be used. In the case of an amination reaction, general reactions such as Buchwald-Hartwig reactions can be used. In addition, in the second reaction, a tandem hetero-Friedel-Crafts reaction (a continuous aromatic electrophilic substitution reaction, the same applies hereinafter) can be used. Regarding these preparation methods, reference can be made to the methods described in existing documents such as International Publication No. 2015 / 102118.

[0247] 3. Organic device

[0248] The polycyclic aromatic compound of the present invention can be used as a material for organic devices. Examples of organic devices include: organic electroluminescent elements, organic field effect transistors, or organic thin film solar cells, etc.

[0249] 3-1. Organic electroluminescent element

[0250] The organic electroluminescent element has at least a pair of electrodes composed of an anode and a cathode and a light emitting layer disposed between the corresponding pair of electrodes. Hereinafter, the organic EL element of the present embodiment will be described in detail based on the drawings.

[0251] 3-1-1. Structure of organic electroluminescent element

[0252] Figure 1 It is a schematic cross-sectional view of an example of an organic EL element. Figure 1 The organic EL element 100 shown includes: a substrate 101, an anode 102 provided on the substrate 101, a hole injection layer 103 provided on the anode 102, a hole transport layer 104 provided on the hole injection layer 103, a light emitting layer 105 provided on the hole transport layer 104, an electron transport layer 106 provided on the light emitting layer 105, an electron injection layer 107 provided on the electron transport layer 106, and a cathode 108 provided on the electron injection layer 107.

[0253] In addition, the organic EL element 100 may also be formed with the manufacturing order reversed to form, for example, the following structure, which includes: a substrate 101, a cathode 108 provided on the substrate 101, an electron injection layer 107 provided on the cathode 108, an electron transport layer 106 provided on the electron injection layer 107, a light-emitting layer 105 provided on the electron transport layer 106, a hole transport layer 104 provided on the light-emitting layer 105, a hole injection layer 103 provided on the hole transport layer 104, and an anode 102 provided on the hole injection layer 103.

[0254] Not all of the above layers are indispensable. The minimum structural unit is set to a structure including the anode 102, the light-emitting layer 105, and the cathode 108. The hole injection layer 103, the hole transport layer 104, the electron transport layer 106, and the electron injection layer 107 are layers that can be optionally provided. In addition, each of the above layers may include a single layer or multiple layers.

[0255] As the form of the layers constituting the organic EL element, in addition to the structural form of "substrate / anode / hole injection layer / hole transport layer / light-emitting layer / electron transport layer / electron injection layer / cathode", it may also be the structural form of "substrate / anode / hole transport layer / light-emitting layer / electron transport layer / electron injection layer / cathode", "substrate / anode / hole injection layer / light-emitting layer / electron transport layer / electron injection layer / cathode", "substrate / anode / hole injection layer / hole transport layer / light-emitting layer / electron injection layer / cathode", "substrate / anode / hole injection layer / hole transport layer / light-emitting layer / electron transport layer / cathode", "substrate / anode / light-emitting layer / electron transport layer / electron injection layer / cathode", "substrate / anode / hole transport layer / light-emitting layer / electron injection layer / cathode", "substrate / anode / hole transport layer / light-emitting layer / electron transport layer / cathode", "substrate / anode / hole injection layer / light-emitting layer / electron injection layer / cathode", "substrate / anode / hole injection layer / light-emitting layer / electron transport layer / cathode", "substrate / anode / light-emitting layer / electron transport layer / cathode", "substrate / anode / light-emitting layer / electron injection layer / cathode".

[0256] 3-1-2. Substrate in organic electroluminescent element

[0257] The substrate 101 is a support for the organic EL element 100, and quartz, glass, metal, plastic, etc. can generally be used. The substrate 101 is formed into a plate shape, a film shape or a sheet shape according to the purpose, and for example, a glass plate, a metal plate, a metal foil, a plastic film, a plastic sheet, etc. can be used. Here, a glass plate and a plate made of a transparent synthetic resin such as polyester, polymethacrylate, polycarbonate, polysulfone, etc. are preferred. If it is a glass substrate, soda-lime glass or alkali-free glass, etc. can be used. In addition, the thickness only needs to be a thickness sufficient to maintain mechanical strength, so for example, it only needs to be 0.2 mm or more. As the upper limit value of the thickness, for example, it is 2 mm or less, and preferably 1 mm or less. Regarding the material of the glass, since the eluted ions from the glass should be less, alkali-free glass is preferred. Since soda-lime glass with a barrier coat such as SiO2 is also commercially available, the soda-lime glass can be used. In addition, in order to improve the gas barrier property, a gas barrier film such as a fine silicon oxide film can be provided on at least one surface of the substrate 101. In the case where a plate, film or sheet made of a synthetic resin with low gas barrier property is used as the substrate 101, it is particularly preferred to provide a gas barrier film.

[0258] 3-1-3. Anode in organic electroluminescent element

[0259] The anode 102 functions to inject holes into the light-emitting layer 105. In addition, when a hole injection layer 103 and / or a hole transport layer 104 are provided between the anode 102 and the light-emitting layer 105, holes are injected into the light-emitting layer 105 via these layers.

[0260] As the material for forming the anode 102, inorganic compounds and organic compounds can be cited. As the inorganic compounds, for example, metals (such as aluminum, gold, silver, nickel, palladium, chromium, etc.), metal oxides (such as indium oxide, tin oxide, indium-tin oxide (ITO), indium-zinc oxide (IZO), etc.), metal halides (such as copper iodide, etc.), copper sulfide, carbon black, ITO glass or Nesa glass, etc. can be cited. As the organic compounds, for example, polythiophenes such as poly(3-methylthiophene), polypyrrole, conductive polymers such as polyaniline, etc. can be cited. In addition, it can be appropriately selected and used from substances used as the anode of the organic EL element.

[0261] The resistance of the transparent electrode only needs to supply sufficient current for the light emission of the light-emitting element, so there is no limitation. However, from the perspective of the power consumption of the light-emitting element, a low resistance is ideal. For example, an ITO substrate with a resistance of 300 Ω / square or less functions as an element electrode, but now substrates with a resistance of around 10 Ω / square can also be supplied. Therefore, it is particularly ideal to use a low-resistance product with a resistance of, for example, 100 Ω / square to 5 Ω / square, preferably 50 Ω / square to 5 Ω / square. The thickness of the ITO can be arbitrarily selected according to the resistance value, but it is usually used in the range of 50 nm to 300 nm.

[0262] 3-1-4. Hole injection layer and hole transport layer in organic electroluminescent element

[0263] The hole injection layer 103 functions to efficiently inject the holes migrated from the anode 102 into the light-emitting layer 105 or the hole transport layer 104. The hole transport layer 104 functions to efficiently transport the holes injected from the anode 102 or the holes injected from the anode 102 via the hole injection layer 103 to the light-emitting layer 105. The hole injection layer 103 and the hole transport layer 104 are formed by laminating and mixing one or more than two kinds of hole injection / transport materials, or are formed by a mixture of a hole injection / transport material and a polymer binder. In addition, an inorganic salt such as iron(III) chloride can be added to the hole injection / transport material to form a layer.

[0264] As the hole injection / transport material, it is necessary to efficiently inject / transport holes from the positive electrode between the electrodes where an electric field is applied. It is ideal that the hole injection efficiency is high and the injected holes are efficiently transported. Therefore, a substance with a small ionization potential, a large hole mobility, excellent stability, and few impurities that can become traps during preparation and use is preferred.

[0265] As the material for forming the hole injection layer 103 and the hole transport layer 104, any compound can be selected from compounds that have been conventionally used as hole charge transport materials in photoconductive materials, p-type semiconductors, and known compounds used in the hole injection layer and the hole transport layer of organic EL elements since before. Specific examples of these are carbazole derivatives (N-phenylcarbazole, polyvinylcarbazole, etc.), biscarbazole derivatives such as bis(N-arylcarbazole) or bis(N-alkylcarbazole), triarylamine derivatives (polymers having an aromatic tertiary amino group in the main chain or side chain, 1,1-bis(4-di-p-tolylaminophenyl)cyclohexane, N,N'-diphenyl-N,N'-di(3-methylphenyl)-4,4'-diaminobiphenyl, N,N'-diphenyl-N,N'-dinaphthyl-4,4'-diaminobiphenyl, N,N'-diphenyl-N,N'-di(3-methylphenyl)-4,4'-diphenyl-1,1'-diamine, N,N'-dinaphthyl-N,N'-diphenyl-4,4'-diphenyl-1,1'-diamine, N4,N4'-diphenyl-N4,N4'-bis(9-phenyl-9H-carbazol-3-yl)-[1,1'-biphenyl]-4,4'-diamine, N4,N4,N4',N4'-tetra[1,1'-biphenyl]-4-yl)-[1,1'-biphenyl]-4,4'-diamine, 4,4',4”-tris(3-methylphenyl(phenyl)amino)triphenylamine, N-([1,1'-biphenyl]-4-yl)-9,9-dimethyl-N-(4-(9-phenyl-9H-carbazol-3-yl)phenyl)-9H-fluorene-2-amine, N,N-bis(4-(dibenzo[b,d]furan-4-yl)phenyl)-[1,1':4',1”-terphenyl]-4-amine and other triarylamine derivatives, starburst amine derivatives, etc.), stilbene derivatives, phthalocyanine derivatives (metal-free, copper phthalocyanine, etc.), pyrazoline derivatives, hydrazone-based compounds, benzofuran derivatives or thiophene derivatives, oxadiazole derivatives, quinoxaline derivatives (for example, 1,4,5,8,9,12-hexaazatriphenylene-2,3,6,7,10,11-hexacarbonitrile, etc.), porphyrin derivatives and other heterocyclic compounds, polysilanes, etc. In the polymer system, polycarbonates or styrene derivatives having the above monomers in the side chain, polyvinylcarbazole, polysilanes, etc. are preferred, but as long as it is a compound that can form a film required for the production of a light-emitting element, inject holes from the anode, and further transport holes, there is no particular limitation.

[0266] In addition, it is also known that the conductivity of organic semiconductors is strongly affected by doping. The organic semiconductor matrix material contains a compound with good electron-donating properties or a compound with good electron-accepting properties. For doping electron-donating substances, strong electron acceptors such as tetracyanoquinonedimethane (TCNQ) or 2,3,5,6-tetrafluorotetracyano-1,4-benzoquinonedimethane (F4TCNQ) are known (for example, refer to the literature "M. Pfeiffer, A. Beyer, T. Fritz, K. Leo (M.Pfeiffer, A.Beyer, T.Fritz, K.Leo), Appl. Phys. Lett., 73(22), 3202-3204 (1998)" and the literature "J. Blochwitz, M. Pfeiffer, T. Fritz, K. Leo (J.Blochwitz, M.Pfeiffer, T.Fritz, K.Leo), Appl. Phys. Lett., 73(6), 729-731 (1998)"). These generate so-called holes through the electron transfer process of the electron-donating type base material (hole transport material). The conductivity of the base material changes considerably according to the number and mobility of the holes. As matrix materials having hole transport properties, for example, benzidine derivatives (such as N,N'-bis(3-methylphenyl)-N,N'-bis(phenyl)benzidine (TPD)) or starburst amine derivatives (such as 4,4',4”-tris(N,N-diphenylamino)triphenylamine (TDATA)), or specific metal phthalocyanines (especially zinc phthalocyanine (ZnPc), etc.) are known (Japanese Patent Laid-Open No. 2005-167175).

[0267] The materials for the hole injection layer and the hole transport layer can also be used as the following polymer compounds or their polymer crosslinked bodies, or the following pendant polymer compounds or their pendant polymer crosslinked bodies in the materials for the hole layer. Here, the polymer compound is obtained by polymerizing a reactive compound having a reactive substituent substituted in the materials for the hole injection layer and the hole transport layer as a monomer, and the pendant polymer compound is obtained by reacting a main chain polymer with the reactive compound. As the reactive substituent in this case, the description in the polycyclic aromatic compound containing the partial structure represented by the formula (1) can be cited.

[0268] Details of the uses of such polymer compounds and polymer crosslinked bodies will be described later.

[0269] 3-1-5. Light-emitting layer in organic electroluminescent element

[0270] The light-emitting layer 105 emits light by recombining holes injected from the anode 102 and electrons injected from the cathode 108 between electrodes to which an electric field is applied. As the material for forming the light-emitting layer 105, any compound (light-emitting compound) that is excited by the recombination of holes and electrons to emit light may be used, and a compound that can form a stable thin film shape and exhibits strong light-emitting (fluorescent) efficiency in the solid state is preferred. The light-emitting layer may be a single layer or may include multiple layers, either of which is acceptable, and each is formed of a material for the light-emitting layer (host material, dopant material). The host material and the dopant material may each be one kind or a combination of multiple kinds, either of which is acceptable. For example, as the dopant material, an emitting dopant and a co-dopant can be used. The dopant material may be included in the entire host material or may be included in a part of the host material, either of which is acceptable. As the doping method, it can be formed by co-evaporation with the host material, or can be co-evaporated after being mixed with the host material in advance. In addition, the light-emitting layer can also be formed by a wet film-forming method using a light-emitting layer-forming composition prepared by dissolving the material in an organic solvent.

[0271] The polycyclic aromatic compound represented by the formula (1) can preferably be used as a material for forming the light-emitting layer of an organic electroluminescent element. The polycyclic aromatic compound represented by the formula (1) is more preferably used as an emitting dopant or a co-dopant in the light-emitting layer, and further preferably used as an emitting dopant.

[0272] The polycyclic aromatic compound represented by formula (1) is a "thermally activated delayed phosphor", which can be used as an emission dopant for an organic EL element that exhibits thermally activated delayed fluorescence (TADF) (hereinafter, sometimes referred to as a "TADF element"). In a "thermally activated delayed phosphor", by reducing the energy difference between the lowest excited singlet state and the lowest excited triplet state, reverse intersystem crossing migration from the lowest excited triplet state to the lowest excited singlet state, which usually has a low migration probability, is efficiently generated, and luminescence from the singlet state (thermally activated delayed fluorescence, TADF) appears. In ordinary fluorescence emission, 75% of the triplet excitons generated by current excitation are thermally deactivated and thus cannot be taken out as fluorescence. On the other hand, in TADF, all excitons can be used for fluorescence emission, and a highly efficient organic EL element can be realized.

[0273] The polycyclic aromatic compound represented by formula (1) can be used as an emission dopant for a "TADF element", an emission dopant for a TADF element using two types of hosts, an emission dopant for an organic electroluminescent element (TADF-assisted fluorescent element, TAF element) that uses an additional thermally activated delayed phosphor as an auxiliary dopant, and an emission dopant for an organic electroluminescent element (phosphor-sensitized fluorescent element, PSF element) that uses a phosphorescent material as an auxiliary dopant. From the viewpoint that the fewer materials used in the element, the easier it is to fabricate, it is preferably an emission dopant for a TADF element and an emission dopant for a TADF element using two types of hosts, and more preferably an emission dopant for a TADF element. From the viewpoint of efficiency, it is preferably an emission dopant for a TAF element and an emission dopant for a phosphorescent auxiliary element, and more preferably an emission dopant for a TAF element.

[0274] Generally, it is considered that a faster delayed fluorescence has excellent TADF properties. Specifically, when a luminescent material with a delayed fluorescence lifetime of 20 μsec or less is used as an emission dopant in a light-emitting element, high element efficiency and a long element lifetime can be obtained. In addition, generally, the smaller the value of ΔE S1T1 , the more excellent the TADF properties. In addition, ΔE S1T1 is the energy difference between the lowest excited singlet state energy level (E S1 ) and the lowest excited triplet state energy level (E T1 ). Specifically, the value of ΔE S1T1 is preferably 0.20 eV or less, and more preferably 0.15 eV or less.

[0275] The light-emitting layer may contain a host compound. Here, the host compound may be one type or two or more types. All known host compounds can be used as the host compound. Preferred examples of the host compound can be the high T1 compounds described later.

[0276] The light-emitting layer may be a single layer or may contain multiple layers, either is acceptable. Additionally, the host compound, the emission dopant material, and the co-dopant material may be contained within the same layer or each may contain at least one component in multiple layers. The host compound and the dopant material (emission dopant or co-dopant) contained in the light-emitting layer may each be one type or a combination of multiple types, either is acceptable. The co-dopant and the emission dopant may be entirely contained in the host compound as the matrix or may be partially contained in the host compound as the matrix.

[0277] The usage amount of the host material varies depending on the type of the host material and can be determined as long as it is coordinated with the characteristics of the host material. The benchmark of the usage amount of the host material is preferably 50% by mass to 99.999% by mass of the total light-emitting layer material, more preferably 80% by mass to 99.95% by mass, and even more preferably 90% by mass to 99.9% by mass.

[0278] The usage amount of the dopant material varies depending on the type of the dopant material and can be determined as long as it is coordinated with the characteristics of the dopant material. The benchmark of the usage amount of the dopant is preferably 0.001% by mass to 50% by mass of the total light-emitting layer material, more preferably 0.05% by mass to 20% by mass, and even more preferably 0.1% by mass to 10% by mass. If it is within the said range, it is preferable in terms of preventing, for example, the concentration quenching phenomenon.

[0279] On the other hand, in an organic electroluminescent element using a TADF material as the dopant material, in terms of preventing the concentration quenching phenomenon, it is preferable that the usage amount of the dopant material is at a low concentration, but in terms of the efficiency of the thermally activated delayed fluorescence mechanism, it is preferable that the usage amount of the dopant material is at a high concentration. Furthermore, in an organic electroluminescent element using a TADF material as the co-dopant, in terms of the efficiency of the thermally activated delayed fluorescence mechanism of the co-dopant, it is preferable that the usage amount of the emission dopant is at a lower concentration compared to the usage amount of the co-dopant.

[0280] When using an auxiliary dopant material, the usage amounts of the host material, auxiliary dopant, and emissive dopant are respectively 40% to 99% by mass, 59% to 1% by mass, and 20% to 0.001% by mass of the total material for the light-emitting layer. Preferably, they are respectively 60% to 95% by mass, 39% to 5% by mass, and 10% to 0.01% by mass. More preferably, they are 70% to 90% by mass, 29% to 10% by mass, and 5% to 0.05% by mass. When using an auxiliary dopant material, an exciplex can be formed with the host material or the emissive dopant material.

[0281] 3-1-5-1. Dopant material

[0282] The polycyclic aromatic compound represented by formula (1) is preferably used as a dopant material.

[0283] As the dopant material that can be used other than the polycyclic aromatic compound represented by formula (1), there is no particular limitation, and known compounds can be used, and they can be selected from various materials according to the desired emission color. Specifically, for example, phenanthrene, anthracene, pyrene, tetracene, pentacene, perylene, naphthopyrene, dibenzopyrene, rubrene, and Condensed ring derivatives such as isobenzothiazole derivatives, benzoxazole derivatives, benzothiazole derivatives, benzimidazole derivatives, benzotriazole derivatives, oxazole derivatives, oxadiazole derivatives, thiazole derivatives, imidazole derivatives, thiadiazole derivatives, triazole derivatives, pyrazoline derivatives, stilbene derivatives, thiophene derivatives, tetraphenylbutadiene derivatives, cyclopentadiene derivatives, bisstyrylanthracene derivatives or bisstyrylbenzene derivatives (Japanese Patent Laid-Open No. 1-245087), bisstyrylarylene derivatives (Japanese Patent Laid-Open No. 2-247278), diazabenzodindenes, furan derivatives, benzofuran derivatives, phenylisobenzofurans, diisopropylisobenzofurans, bis(2-methylphenyl)isobenzofurans, bis(2-trifluoromethylphenyl)isobenzofurans, phenylisobenzofurans and other isobenzofuran derivatives, dibenzofuran derivatives, 7-dialkylaminocoumarin derivatives, 7-piperidinocoumarin derivatives, 7-hydroxycoumarin derivatives, 7-methoxycoumarin derivatives, 7-acetoxycoumarin derivatives, 3-benzothiazolylcoumarin derivatives, 3-benzimidazolylcoumarin derivatives, 3-benzoxazolylcoumarin derivatives and other coumarin derivatives, dicyanomethylene pyran derivatives, dicyanomethylene thiopyran derivatives, polymethine derivatives, cyanine derivatives, oxobenzanthracene derivatives, xanthene derivatives, rhodamine derivatives, fluorescein derivatives, pyranylium derivatives, quinolone derivatives, acridine derivatives, oxazine derivatives, phenyl ether derivatives, quinacridone derivatives, quinazoline derivatives, pyrrolopyridine derivatives, furanopyridine derivatives, 1,2,5-thiadiazolo pyrene derivatives, pyrromethene derivatives, perinone derivatives, pyrrolopyrrole derivatives, squarylium derivatives, violanthrone derivatives, phenazine derivatives, acridone derivatives, deazaflavin derivatives, fluorene derivatives and benzofluorene derivatives, etc.

[0284] If the coloring light is exemplified respectively, as the blue dopant material to blue-green dopant material, the following can be cited: naphthalene, anthracene, phenanthrene, pyrene, triphenylene, perylene, fluorene, indene, and other aromatic hydrocarbon compounds or their derivatives, furan, pyrrole, thiophene, silole, 9-silafluorene, 9,9'-spirobisfluorene, benzothiophene, benzofuran, indole, dibenzothiophene, dibenzofuran, imidazopyridine, phenanthroline, pyrazine, naphthyridine, quinoxaline, pyrrolopyridine, thioxanthene and other aromatic heterocyclic compounds or their derivatives, bisstyrylbenzene derivatives, tetraphenylbutadiene derivatives, stilbene derivatives, azine derivatives, coumarin derivatives, imidazole, thiazole, thiadiazole, carbazole, oxazole, oxadiazole, triazole and other azole derivatives and their metal complexes and aromatic amine derivatives represented by N,N'-diphenyl-N,N'-bis(3-methylphenyl)-4,4'-diphenyl-1,1'-diamine, etc.

[0285] In addition, examples of the green dopant material to yellow dopant material include: coumarin derivatives, phthalimide derivatives, naphthalenedicarboximide derivatives, perinone derivatives, pyrrolopyrrole derivatives, cyclopentadiene derivatives, acridone derivatives, quinacridone derivatives, and tetracene derivatives such as rubrene. Furthermore, the following compounds can also be cited as preferred examples: compounds obtained by introducing substituents capable of causing a long wavelength shift, such as aryl, heteroaryl, arylvinyl, amino, and cyano groups, into the compounds exemplified as the blue dopant material to blue-green dopant material.

[0286] Furthermore, examples of the orange dopant material to red dopant material include: naphthalenedicarboximide derivatives such as bis(diisopropylphenyl)perylene tetracarboxylic diimide, perinone derivatives, rare earth complexes such as Eu complexes having acetylacetone or benzoylacetone as ligands and phenanthroline, 4-(dicyanomethylene)-2-methyl-6-(p-dimethylaminostyryl)-4H-pyran or its analogs, metal phthalocyanine derivatives such as magnesium phthalocyanine and aluminum chloro phthalocyanine, rhodamine compounds, deazaflavin derivatives, coumarin derivatives, quinacridone derivatives, phenoxazine derivatives, oxazine derivatives, quinazoline derivatives, pyrrolopyridine derivatives, squarylium salt derivatives, violanthrone derivatives, phenazine derivatives, phenoxazinone derivatives, and thiazolopyrene derivatives. Furthermore, the following compounds can also be cited as preferred examples: compounds obtained by introducing substituents capable of causing a long wavelength shift, such as aryl, heteroaryl, arylvinyl, amino, and cyano groups, into the compounds exemplified as the blue dopant material to blue-green dopant material and green dopant material to yellow dopant material.

[0287] In addition, as the dopant, it can be appropriately selected and used from compounds described in, for example, page 13 of the June 2004 issue of Chemical Industry and the references cited therein.

[0288] Among the dopant materials, amines having a stilbene structure, perylene derivatives, borane derivatives, aromatic amine derivatives, coumarin derivatives, pyran derivatives, or pyrene derivatives are particularly preferred.

[0289] The amine having a stilbene structure is represented by the following formula, for example.

[0290]

[0291] In the formula, Ar 1 is an m-valent group derived from an aryl group having 6 to 30 carbon atoms, Ar 2 and Ar 3 are each independently an aryl group having 6 to 30 carbon atoms, and at least one of Ar 1 to Ar 3 has a stilbene structure, Ar1 ~Ar 3 It may be substituted by an aryl, heteroaryl, alkyl, cycloalkyl, trisubstituted silyl (a silyl trisubstituted by an aryl, alkyl and / or cycloalkyl), or cyano group, and m is an integer of 1 to 4.

[0292] The amine having a stilbene structure is more preferably a diaminostilbene represented by the following formula.

[0293]

[0294] In the formula, Ar 2 and Ar 3 are each independently an aryl group having 6 to 30 carbon atoms, and Ar 2 and Ar 3 may be substituted by an aryl, heteroaryl, alkyl, cycloalkyl, trisubstituted silyl (a silyl trisubstituted by an aryl, alkyl and / or cycloalkyl), or cyano group.

[0295] Specific examples of the aryl group having 6 to 30 carbon atoms include: phenyl, naphthyl, acenaphthyl, fluorenyl, phenalenyl, phenanthryl, anthryl, fluoranthenyl, triphenylenyl, pyrenyl, -yl, tetraphenylenyl, perylenyl, stilbenyl, stilbenylphenyl, stilbenylbiphenyl, stilbenylfluorenyl, etc.

[0296] Specific examples of the amine having a stilbene structure include: N,N,N',N'-tetrakis(4-biphenylyl)-4,4'-diaminostilbene, N,N,N',N'-tetrakis(1-naphthyl)-4,4'-diaminostilbene, N,N,N',N'-tetrakis(2-naphthyl)-4,4'-diaminostilbene, N,N'-bis(2-naphthyl)-N,N'-diphenyl-4,4'-diaminostilbene, N,N'-bis(9-phenanthryl)-N,N'-diphenyl-4,4'-diaminostilbene, 4,4'-bis[4”-bis(diphenylamino)styryl]-biphenyl, 1,4-bis[4'-bis(diphenylamino)styryl]-benzene, 2,7-bis[4'-bis(diphenylamino)styryl]-9,9-dimethylfluorene, 4,4'-bis(9-ethyl-3-carbazolylvinyl)-biphenyl, 4,4'-bis(9-phenyl-3-carbazolylvinyl)-biphenyl, etc.

[0297] In addition, amines having a stilbene structure described in Japanese Patent Application Laid-Open No. 2003-347056 and Japanese Patent Application Laid-Open No. 2001-307884 may also be used.

[0298] As perylene derivatives, for example, the following can be cited: 3,10-bis(2,6-dimethylphenyl)perylene, 3,10-bis(2,4,6-trimethylphenyl)perylene, 3,10-diphenylperylene, 3,4-diphenylperylene, 2,5,8,11-tetra-tert-butylperylene, 3,4,9,10-tetraphenylperylene, 3-(1'-pyrenyl)-8,11-di(tert-butyl)perylene, 3-(9'-anthryl)-8,11-di(tert-butyl)perylene, 3,3'-bis(8,11-di(tert-butyl)perylenyl), etc.

[0299] In addition, perylene derivatives described in Japanese Patent Laid-Open No. 11-97178, Japanese Patent Laid-Open No. 2000-133457, Japanese Patent Laid-Open No. 2000-26324, Japanese Patent Laid-Open No. 2001-267079, Japanese Patent Laid-Open No. 2001-267078, Japanese Patent Laid-Open No. 2001-267076, Japanese Patent Laid-Open No. 2000-34234, Japanese Patent Laid-Open No. 2001-267075, and Japanese Patent Laid-Open No. 2001-217077, etc. can also be used.

[0300] As borane derivatives, for example, the following can be cited: 1,8-diphenyl-10-(di-mesitylboranyl)anthracene, 9-phenyl-10-(di-mesitylboranyl)anthracene, 4-(9'-anthryl)di-mesitylboranylnaphthalene, 4-(10'-phenyl-9'-anthryl)di-mesitylboranylnaphthalene, 9-(di-mesitylboranyl)anthracene, 9-(4'-biphenylyl)-10-(di-mesitylboranyl)anthracene, 9-(4'-(N-carbazolyl)phenyl)-10-(di-mesitylboranyl)anthracene, etc.

[0301] In addition, borane derivatives described in International Publication No. 2000 / 40586, etc. can also be used.

[0302] The aromatic amine derivative is represented by the following formula.

[0303]

[0304] In the formula, Ar 4 is an n-valent group derived from an aryl group having 6 to 30 carbon atoms, Ar 5 and Ar 6 are each independently an aryl group having 6 to 30 carbon atoms, Ar 4 to Ar 6 may be substituted with an aryl group, a heteroaryl group, an alkyl group, a cycloalkyl group, a trisubstituted silyl group (a silyl group trisubstituted with an aryl group, an alkyl group, and / or a cycloalkyl group), or a cyano group, and n is an integer of 1 to 4.

[0305] Particularly preferably, the aromatic amine derivative is as follows: Ar4 is a divalent group derived from anthracene, fluorene, benzofluorene or pyrene, Ar 5 and Ar 6 are each independently an aryl group having 6 to 30 carbon atoms, Ar 4 ~Ar 6 may be substituted with an aryl group, a heteroaryl group, an alkyl group, a cycloalkyl group, a trisubstituted silyl group (a silyl group trisubstituted with an aryl group, an alkyl group and / or a cycloalkyl group) or a cyano group, and n is 2.

[0306] Specific examples of the aryl group having 6 to 30 carbon atoms include: phenyl, naphthyl, acenaphthyl, fluorenyl, phenalenyl, phenanthryl, anthryl, fluoranthenyl, triphenylenyl, pyrenyl, chrysenyl, tetraphenylenyl, perylenyl, pentaphenylenyl, etc.

[0307] As the aromatic amine derivative, as the series, for example, can be cited: N,N,N',N'-tetraphenyl -6,12-diamine, N,N,N',N'-tetrakis(p-tolyl) -6,12-diamine, N,N,N',N'-tetrakis(m-tolyl) -6,12-diamine, N,N,N',N'-tetrakis(4-isopropylphenyl) -6,12-diamine, N,N,N',N'-tetrakis(naphthalen-2-yl) -6,12-diamine, N,N'-diphenyl-N,N'-bis(p-tolyl) -6,12-diamine, N,N'-diphenyl-N,N'-bis(4-ethylphenyl) -6,12-diamine, N,N'-diphenyl-N,N'-bis(4-isopropylphenyl) -6,12-diamine, N,N'-diphenyl-N,N'-bis(4-tert-butylphenyl) -6,12-diamine, N,N'-bis(4-isopropylphenyl)-N,N'-bis(p-tolyl) -6,12-diamine, etc.

[0308] In addition, as pyrene-based compounds, for example, the following can be cited: N,N,N',N'-tetraphenylpyrene-1,6-diamine, N,N,N',N'-tetrakis(p-tolyl)pyrene-1,6-diamine, N,N,N',N'-tetrakis(m-tolyl)pyrene-1,6-diamine, N,N,N',N'-tetrakis(4-isopropylphenyl)pyrene-1,6-diamine, N,N,N',N'-tetrakis(3,4-dimethylphenyl)pyrene-1,6-diamine, N,N'-diphenyl-N,N'-bis(p-tolyl)pyrene-1,6-diamine, N,N'-diphenyl-N,N'-bis(4-ethylphenyl)pyrene-1,6-diamine, N,N'-diphenyl-N,N'-bis(4-isopropylphenyl)pyrene-1,6-diamine, N,N'-diphenyl-N,N'-bis(4-tert-butylphenyl)pyrene-1,6-diamine, N,N'-bis(4-isopropylphenyl)-N,N'-bis(p-tolyl)pyrene-1,6-diamine, N,N,N',N'-tetrakis(3,4-dimethylphenyl)-3,8-diphenylpyrene-1,6-diamine, N,N,N,N-tetraphenylpyrene-1,8-diamine, N,N'-bis(biphenyl-4-yl)-N,N'-diphenylpyrene-1,8-diamine, N 1 ,N 6 -diphenyl-N 1 ,N 6 -bis-(4-trimethylsilyl-phenyl)-1H,8H-pyrene-1,6-diamine and the like.

[0309] In addition, as anthracene-based compounds, for example, the following can be cited: N,N,N,N-tetraphenylanthracene-9,10-diamine, N,N,N',N'-tetrakis(p-tolyl)anthracene-9,10-diamine, N,N,N',N'-tetrakis(m-tolyl)anthracene-9,10-diamine, N,N,N',N'-tetrakis(4-isopropylphenyl)anthracene-9,10-diamine, N,N'-diphenyl-N,N'-di(p-tolyl)anthracene-9,10-diamine, N,N'-diphenyl-N,N'-di(m-tolyl)anthracene-9,10-diamine, N,N'-diphenyl-N,N'-bis(4-ethylphenyl)anthracene-9,10-diamine, N,N'-diphenyl-N,N'-bis(4-isopropylphenyl)anthracene-9,10-diamine, N,N'-diphenyl-N,N'-bis(4-tert-butylphenyl)anthracene-9,10-diamine, N,N'-bis(4-isopropylphenyl)-N,N'-di(p-tolyl)anthracene-9,10-diamine, 2,6-di-tert-butyl-N,N,N',N'-tetrakis(p-tolyl)anthracene-9,10-diamine, 2,6-di-tert-butyl-N,N'-diphenyl-N,N'-bis(4-isopropylphenyl)anthracene-9,10-diamine, 2,6-di-tert-butyl-N,N'-bis(4-isopropylphenyl)-N,N'-di(p-tolyl)anthracene-9,10-diamine, 2,6-dicyclohexyl-N,N'-bis(4-isopropylphenyl)-N,N'-di(p-tolyl)anthracene-9,10-diamine, 2,6-dicyclohexyl-N,N'-bis(4-isopropylphenyl)-N,N'-bis(4-tert-butylphenyl)anthracene-9,10-diamine, 9,10-bis(4-diphenylaminophenyl)anthracene, 9,10-bis(4-di(1-naphthylamino)phenyl)anthracene, 9,10-bis(4-di(2-naphthylamino)phenyl)anthracene, 10-di-p-tolylamino-9-(4-di-p-tolylamino-1-naphthyl)anthracene, 10-diphenylamino-9-(4-diphenylamino-1-naphthyl)anthracene, 10-diphenylamino-9-(6-diphenylamino-2-naphthyl)anthracene, etc.

[0310] In addition, the following can be cited: [4-(4-diphenylaminophenyl)naphthalen-1-yl]-diphenylamine, [6-(4-diphenylaminophenyl)naphthalen-2-yl]-diphenylamine, 4,4'-bis[4-diphenylaminonaphthalen-1-yl]biphenyl, 4,4'-bis[6-diphenylaminonaphthalen-2-yl]biphenyl, 4,4”-bis[4-diphenylaminonaphthalen-1-yl]-p-terphenyl, 4,4”-bis[6-diphenylaminonaphthalen-2-yl]-p-terphenyl, etc.

[0311] In addition, aromatic amine derivatives described in Japanese Patent Laid-Open No. 2006-156888 etc. can also be used.

[0312] Examples of the coumarin derivatives include coumarin-6, coumarin-334, etc.

[0313] In addition, coumarin derivatives described in Japanese Patent Application Laid-Open No. 2004-43646, Japanese Patent Application Laid-Open No. 2001-76876, Japanese Patent Application Laid-Open No. 6-298758, etc. can also be used.

[0314] Examples of the pyran derivatives include the following pyran nitrile derivatives (DCM), (E)-4-(dicyanomethylene)-2-tert-butyl-6-(1,1,7,7-tetramethyljulolidin-4-yl-vinyl)-4H-pyran (DCJTB), etc.

[0315]

[0316] In addition, pyran derivatives described in Japanese Patent Application Laid-Open No. 2005-126399, Japanese Patent Application Laid-Open No. 2005-097283, Japanese Patent Application Laid-Open No. 2002-234892, Japanese Patent Application Laid-Open No. 2001-220577, Japanese Patent Application Laid-Open No. 2001-081090, Japanese Patent Application Laid-Open No. 2001-052869, etc. can also be used.

[0317] As the dopant material, the following compounds can be used.

[0318]

[0319] 3-1-5-2. High T1 compound

[0320] In an organic electroluminescent element in which at least one polycyclic aromatic compound represented by the formula (1) is contained in the light-emitting layer, it is preferable that at least one high T1 compound is further contained in the light-emitting layer or an organic layer adjacent to the light-emitting layer, and the high T1 compound has a lowest excited triplet energy level (ET1) (sometimes also referred to as "T1 energy") that is at least 0.01 eV higher than the lowest excited triplet energy level of the polycyclic aromatic compound represented by the formula (1).

[0321] A high-T1 compound can be used as a host compound when, for example, a polycyclic aromatic compound represented by the formula (1) is used as a dopant compound in a light-emitting layer. The high-T1 compound can be included singly or in two or more kinds in the light-emitting layer. When two or more kinds are included, it is preferable to include a hole-transporting host material and an electron-transporting host material that satisfy the following relationship.

[0322] The HOMO (Highest Occupied Molecular Orbital) of the hole-transporting host material (HH) is shallower than the HOMO of the electron-transporting host material (EH).

[0323] The LUMO (Lowest Unoccupied Molecular Orbital) of the electron-transporting host material (EH) is deeper than the LUMO of the hole-transporting host material (HH).

[0324] The E of the high-T1 compound T1 is more preferably 0.03 eV or more higher than that of the polycyclic aromatic compound represented by the formula (1), and still more preferably 0.1 eV or more higher. T1 As the high-T1 compound, preferably: a compound having at least one partial structure selected from partial structure group A, or having at least two partial structures selected from partial structure group A and partial structure group B, and further may have at least one partial structure selected from partial structure group C as a linking group or a substituent. In addition, in each of the following structures, at at least one *, it is bonded to other partial structures other than hydrogen, and at other *s, it is bonded to hydrogen. As can be seen from the following structural formulas, the carbon-carbon bonds connecting the benzene rings in each partial structure and the bonds connecting the partial structures are ortho or meta positions. At this time, high T1 and high charge mobility are obtained. From the viewpoint of high T1, bonding at the ortho position is preferred, and from the viewpoint of high charge mobility, bonding at the meta position is preferred.

[0325] Partial structure group A

[0326] Partial structure group A

[0327]

[0328] Partial structure group B

[0329]

[0330] Partial structure group C

[0331]

[0332] Partial structure group A is preferably partial structure group Aa, partial structure group B is preferably partial structure group Bb, and partial structure group C is preferably partial structure group Cc.

[0333] Partial structural group Aa

[0334]

[0335] Partial structural group Bb

[0336]

[0337] Partial structural group Cc

[0338]

[0339] As high-T1 compounds, for example, the following can be cited: the compound represented by the following formula (H1), the compound represented by the following formula (H3), the compound containing the structure represented by the following formula (H4), the compound represented by the following formula (H5), the compounds represented by the following formula (H6) and the following formula (H8).

[0340]

[0341] 3-1-5-2-1. The compound represented by formula (H1)

[0342]

[0343] In formula (H1), L 1 is an arylene group having 6 to 24 carbon atoms or a heteroarylene group having 5 to 23 carbon atoms, preferably an arylene group having 6 to 16 carbon atoms and a heteroarylene group having 5 to 15 carbon atoms, more preferably an arylene group having 6 to 12 carbon atoms and / or a heteroarylene group having 5 to 11 carbon atoms, particularly preferably an arylene group having 6 to 10 carbon atoms or a heteroarylene group having 5 to 9 carbon atoms. Specifically, divalent or trivalent groups such as benzene ring, biphenyl ring, terphenyl ring, fluorene ring, spirofluorene ring, phenalene ring, triphenylene ring, pyridine ring, pyrimidine ring, triazine ring, bipyridyl ring, biphenylpyrimidine ring and biphenyltriazine ring can be cited.

[0344] In the compound represented by formula (H1), at least one hydrogen can be substituted by an alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 3 to 14 carbon atoms, a cyano group, a halogen or deuterium.

[0345]

[0346] 3-1-5-2-2. Compound represented by formula (H3)

[0347]

[0348] In formula (H3),

[0349] MU are each independently a divalent aromatic group, EC are each independently a monovalent aromatic group, and k is an integer of 2 to 50000.

[0350] More specifically,

[0351] MU is independently an arylene, heteroarylene, diarylarylamino, diarylarylboron, oxaborane-diyl, azaborane-diyl,

[0352] EC is independently hydrogen, aryl, heteroaryl, diarylamino, diheteroarylamino, arylheteroarylamino or aryloxy,

[0353] At least one hydrogen in MU and EC may further be substituted with aryl, heteroaryl, diarylamino, alkyl and cycloalkyl,

[0354] k is an integer from 2 to 50000.

[0355] k is preferably an integer from 20 to 50000, more preferably an integer from 100 to 50000.

[0356] At least one hydrogen in MU and EC in formula (H3) may be substituted with an alkyl having 1 to 24 carbon atoms, a cycloalkyl having 3 to 24 carbon atoms, a halogen or deuterium. Further, any -CH2- in the alkyl may be substituted with -O- or -Si(CH3)2-. Any -CH2- in the alkyl other than the -CH2- directly bonded to EC in formula (H3) may be substituted with an arylene having 6 to 24 carbon atoms. Any hydrogen in the alkyl may be substituted with fluorine.

[0357] As MU, for example, divalent derivatives having the following structures can be cited (for example, a divalent group represented by removing any two hydrogen atoms from any one of the following compounds, a divalent group including a combination of two or more divalent groups represented by removing any two hydrogen atoms from any one of the following compounds, a divalent group in which at least one of the hydrogens in these groups is substituted with an alkyl, etc.).

[0358]

[0359] More specifically, divalent groups having any one of the following structures can be cited. Among these, MU is bonded to another MU or EC at *.

[0360]

[0361]

[0362] In addition, as EC, for example, groups represented by the following formulas can be cited. Among these, EC is bonded to MU at *.

[0363]

[0364]

[0365] In terms of solubility and coatability to form a film, in the compound represented by formula (H3), it is preferred that 10% to 100% of the total number (k) of MUs in the molecule have an alkyl group with 1 to 24 carbon atoms, more preferably 30% to 100% of the total number (k) of MUs in the molecule have an alkyl group with 1 to 18 carbon atoms (branched alkyl group with 3 to 18 carbon atoms), and still more preferably 50% to 100% of the total number (k) of MUs in the molecule have an alkyl group with 1 to 12 carbon atoms (branched alkyl group with 3 to 12 carbon atoms). On the other hand, in terms of in-plane orientation and charge transport, it is preferred that 10% to 100% of the total number (k) of MUs in the molecule have an alkyl group with 7 to 24 carbon atoms, more preferably 30% to 100% of the total number (k) of MUs in the molecule have an alkyl group with 7 to 24 carbon atoms (branched alkyl group with 7 to 24 carbon atoms).

[0366] 3-1-5-2-3. Compound containing structure represented by formula (H4)

[0367] The compound containing the structure represented by formula (H4) is contained in a plurality, preferably 1 to 5, more preferably 1 to 3, still more preferably 1 to 2, and most preferably 1 structure represented by formula (H4). In the case of containing a plurality, the structures are directly bonded to each other by a single bond or bonded through a specific linking group.

[0368]

[0369] In formula (H4), G is "=C(-H)-" or "=N-", and the H in the "=C(-H)-" can be substituted by a substituent or a structure represented by another formula (H4).

[0370] As the compound containing the structure represented by formula (H4), for example, the compounds described in International Publication No. 2012 / 153780 and International Publication No. 2013 / 038650 etc. can be used, and they can be prepared according to the methods described in the said documents.

[0371] Examples of the substituent in the case where the H in the "=C(-H)-" as G is substituted include: aryl group, heteroaryl group, substituted silyl group, substituted phosphine oxide group, and substituted carboxyl group etc.

[0372] Specific examples of the "aryl group" as the substituent include: phenyl group, tolyl group, xylyl group, triphenylenyl group, fluorenyl group, 9,9-dimethylfluorenyl group, benzofluorenyl group, dibenzofluorenyl group, biphenyl group, terphenyl group, quaterphenyl group etc., and preferably phenyl group, biphenyl group, terphenyl group and fluorenyl group etc. can be cited. As the aryl group having a substituent, tolyl group, xylyl group and 9,9-dimethylfluorenyl group etc. can be cited. As shown by the specific examples, the aryl group includes both condensed aryl group and non-condensed aryl group.

[0373] Specific examples of the "heteroaryl group" as a substituent include: pyrrolyl, pyrazolyl, pyrazinyl, pyrimidinyl, pyridazinyl, pyridyl, triazinyl, indolyl, isoindolyl, imidazolyl, benzimidazolyl, indazolyl, imidazo[1,2-a]pyridyl, furyl, benzofuryl, isobenzofuryl, dibenzofuryl, azadibenzofuryl, thienyl, benzothienyl, dibenzothienyl, azadibenzothienyl, quinolinyl, isoquinolinyl, quinoxalinyl, quinazolinyl, naphthyridinyl, carbazolyl, azacarbazolyl, phenanthridinyl, acridinyl, phenazinyl, phenothiazinyl, phenoxazinyl, oxazolyl, oxadiazolyl, furazanyl, benzoxazolyl, thiazolyl, thiadiazolyl, benzothiazolyl, triazolyl, tetrazolyl, etc. Preferred examples include dibenzofuryl, dibenzothienyl, carbazolyl, pyridyl, pyrimidinyl, triazinyl, azadibenzofuryl, and azadibenzothienyl. Further preferred are dibenzofuryl, dibenzothienyl, azadibenzofuryl, or azadibenzothienyl.

[0374] The "substituted silyl group" as a substituent is also preferably a group selected from the group consisting of substituted or unsubstituted trialkylsilyl groups, substituted or unsubstituted arylalkylsilyl groups, and substituted or unsubstituted triarylsilyl groups.

[0375] Specific examples of the substituted or unsubstituted trialkylsilyl group include trimethylsilyl and triethylsilyl. Specific examples of the substituted or unsubstituted arylalkylsilyl group include diphenylmethylsilyl, dimethylxenylmethylsilyl, and phenyldimethylsilyl, etc. Specific examples of the substituted or unsubstituted triarylsilyl group include triphenylsilyl and tritolylsilyl, etc.

[0376] The "substituted phosphinyl group" as a substituent is also preferably a substituted or unsubstituted diarylphosphinyl group. Specific examples of the substituted or unsubstituted diarylphosphinyl group include diphenylphosphine oxide and dimethylxenylphosphine oxide, etc.

[0377] Regarding the "substituted carboxyl group" as a substituent, for example, benzoyloxy, etc. can be cited.

[0378] As the linking group for bonding multiple structures represented by formula (H4), divalent to tetravalent, divalent to trivalent, or divalent derivatives of the aryl or heteroaryl group can be cited.

[0379] Specific examples of the compound containing the structure represented by formula (H4) are shown below.

[0380]

[0381]

[0382] 3-1-5-2-4. Compound represented by formula (H5) and compound represented by formula (H6)

[0383] 3-1-5-2-4-1. Compound represented by formula (H5)

[0384]

[0385] In formula (H5), R 1 ~R 11 are each independently hydrogen, aryl, heteroaryl, diarylamino, diheteroarylamino, arylheteroarylamino or aryloxy, and at least one hydrogen among these may further be substituted with aryl, heteroaryl or diarylamino.

[0386] In addition, at least one (preferably 1 to 3) of the -C(R n )= in formula (H5) (n is 1 to 11) may be substituted with -N=.

[0387] At least one hydrogen in the compound represented by formula (H5) may be substituted with an alkyl group having 1 to 24 carbon atoms, and any -CH2- in the alkyl group may be substituted with -O- or -Si(CH3)2-, any -CH2- other than the -CH2- directly bonded to the compound represented by formula (H5) in the alkyl group may be substituted with an arylene group having 6 to 24 carbon atoms, and any hydrogen in the alkyl group may be substituted with fluorine.

[0388] In addition, at least one hydrogen in the compound represented by formula (H5) may be substituted with a halogen or deuterium.

[0389] 3-1-5-2-4-2. Compound represented by formula (H6)

[0390]

[0391] In formula (H6), R 1 ~R 16 are each independently hydrogen, aryl, heteroaryl, diarylamino, diheteroarylamino, arylheteroarylamino or aryloxy, and at least one hydrogen among these may further be substituted with aryl, heteroaryl or diarylamino.

[0392] In addition, at least one hydrogen in the compound represented by formula (H-6) may be substituted with an alkyl group having 1 to 24 carbon atoms, and any -CH2- in the alkyl group may be substituted with -O- or -Si(CH3)2-, any -CH2- other than the -CH2- directly bonded to the compound represented by formula (H6) in the alkyl group may be substituted with an arylene group having 6 to 24 carbon atoms, and any hydrogen in the alkyl group may be substituted with fluorine.

[0393] In addition, at least one hydrogen in the compound represented by formula (H6) may be substituted with a halogen or deuterium.

[0394] 3-1-5-2-4-3. "R in formula (H5) 1 ～R 11 " and "R in formula (H6) 1 ～R 16 ”

[0395] “R in formula (H5) 1 ~R 11 ” and “R in formula (H6) 1 ~R 16 ” are each independently hydrogen, aryl, heteroaryl, diarylamino, diheteroarylamino, arylheteroarylamino or aryloxy, preferably aryl having 6 to 30 carbon atoms, heteroaryl having 2 to 30 carbon atoms, diarylamino (amino having two aryl groups each having 6 to 30 carbon atoms), diheteroarylamino (amino having two heteroaryl groups each having 2 to 30 carbon atoms), arylheteroarylamino (amino having an aryl group having 6 to 30 carbon atoms and a heteroaryl group having 2 to 30 carbon atoms) or aryloxy having 6 to 30 carbon atoms.

[0396] Examples of the aryl group as “aryl”, “aryl of diarylamino”, “aryl of arylheteroarylamino” and “aryloxy” include: a benzene ring which is a monocyclic system, a biphenyl ring which is a bicyclic system, a naphthalene ring which is a condensed bicyclic system, a terphenyl ring (meta-terphenyl, ortho-terphenyl, para-terphenyl) which is a tricyclic system, an acenaphthene ring, a fluorene ring, a phenalene ring, a phenanthrene ring which are condensed tricyclic systems, a triphenylene ring, a pyrene ring, a tetracene ring which are condensed tetracyclic systems, a perylene ring, a pentacene ring which are condensed pentacyclic systems, etc. Further, as described later, a group in which the following-defined heteroaryl is substituted on these aryl groups is also defined as an aryl group in formula (H5) and formula (H6).

[0397] Examples of the heteroaryl group as “heteroaryl”, “heteroaryl of diheteroarylamino” and “heteroaryl of arylheteroarylamino” include: monovalent groups such as a pyrrole ring, an oxazole ring, an isoxazole ring, a thiazole ring, an isothiazole ring, an imidazole ring, an oxadiazole ring, a thiadiazole ring, a triazole ring, a tetrazole ring, a pyrazole ring, a pyridine ring, a pyrimidine ring, a pyridazine ring, a pyrazine ring, a triazine ring, an indole ring, an isoindole ring, a 1H-indazole ring, a benzimidazole ring, a benzoxazole ring, a benzothiazole ring, a 1H-benzotriazole ring, a quinoline ring, an isoquinoline ring, a cinnoline ring, a quinazoline ring, a quinoxaline ring, a phthalazine ring, a naphthyridine ring, a purine ring, a pteridine ring, a carbazole ring, an acridine ring, a phenoxathiin ring, a phenoxazine ring, a phenothiazine ring, a phenazine ring, an indolizine ring, a furan ring, a benzofuran ring, an isobenzofuran ring, a dibenzofuran ring, a thiophene ring, a benzothiophene ring, a dibenzothiophene ring, a furazan ring, an oxadiazole ring, a thianthrene ring and the heteroaryl group substituted with an N-aryl group, etc. Further, as described later, a group in which the above-defined aryl group is substituted on these heteroaryl groups is also defined as a heteroaryl group in formula (H5) and formula (H6).

[0398] In addition, regarding R in formula (H5) 1 ~R 11 or R in formula (H6) 1 ~R 16 The aryl, heteroaryl, diarylamino, diheteroarylamino, arylheteroarylamino or aryloxy groups described, at least one hydrogen in these may further be substituted by an aryl, heteroaryl or diarylamino group. As the aryl, heteroaryl or diarylamino group for such substitution, those same as the groups described in R 1 ~R 11 or R 1 ~R 16 column can be cited.

[0399] As specific groups for R 1 ~R 11 or R 1 ~R 16 For example, the groups represented by the following formula (RG-1) to formula (RG-10) can be cited. In addition, the groups represented by the following formula (RG-1) to formula (RG-10) are bonded to the a-ring to d-ring in formula (H5) or formula (H6) at the *.

[0400]

[0401] If the specific groups are used as a reference to explain the "aryl" and "heteroaryl" defined in formula (H5) and formula (H6), then formula (RG-1), formula (RG-4) and formula (RG-7) are aryl, formula (RG-2), formula (RG-3) and formula (RG-6) are heteroaryl, formula (RG-9) is a heteroaryl substituted by a heteroaryl, and formula (RG-10) is an aryl substituted by a heteroaryl. In addition, formula (RG-5) is an aryl (phenyl) substituted by a diarylamino (diphenylamino), and formula (RG-8) is a diarylamino (diphenylamino).

[0402]

[0403] 3-1-5-2-4-4. Specific examples of compounds

[0404] Hereinafter, a more specific structure of the compound represented by formula (H5) or formula (H6) is shown.

[0405] The specific structure of the compound represented by the following formula (H5) or formula (H6) can be substituted by an alkyl group having 1 to 24 carbon atoms.

[0406]

[0407]

[0408]

[0409]

[0410]

[0411]

[0412]

[0413]

[0414]

[0415]

[0416]

[0417]

[0418]

[0419]

[0420]

[0421]

[0422]

[0423] 3-1-5-2-4-5. Preparation method of compound represented by formula (H5) or formula (H6)

[0424] The compound represented by formula (H5) first bonds the a-ring to the c-ring using a bonding group (-O-), thereby preparing an intermediate (first reaction). Thereafter, the a-ring to the c-ring are bonded using a bonding group (a group containing B), thereby preparing the final product (second reaction). In addition, the compound represented by formula (H6) first bonds the a-ring to the d-ring using a bonding group (>NH or a single bond), thereby preparing an intermediate (first reaction). Thereafter, the a-ring to the d-ring are bonded using a bonding group (a group containing B), thereby preparing the final product (second reaction). In the first reaction, for example, in the case of an etherification reaction, general reactions such as a nucleophilic substitution reaction or an Ullmann reaction can be used. In the case of an amination reaction, general reactions such as a Buchwald-Hartwig reaction can be used. In addition, in the second reaction, a tandem-type Friedel-Crafts reaction (successive aromatic electrophilic substitution reaction, the same applies hereinafter) can be used.

[0425] <Preparation method: Example of the second reaction of the compound represented by formula (H5)>

[0426] As shown in the following process (1), the second reaction is a reaction for introducing B (boron) that bonds the a-ring, b-ring, and c-ring. As an example, the case of the compound represented by the formula (H5) is shown below. First, ortho-metalation of the hydrogen atom between the two Os is carried out using n-butyllithium, sec-butyllithium, tert-butyllithium, or the like. Subsequently, boron trichloride or boron tribromide is added, and after lithium-boron metal exchange, a Brønsted base such as N,N-diisopropylethylamine is added, whereby a tandem bora-Friedel-Crafts reaction is carried out to obtain the target product. In the second reaction, a Lewis acid such as aluminum trichloride may also be added to promote the reaction.

[0427] Process (1)

[0428]

[0429] In the said process, lithium is introduced at the desired position by ortho-metalation, but a bromine atom or the like may be introduced at the position where lithium is to be introduced as in the following process (2), and lithium can also be introduced at the desired position by halogen-metal exchange.

[0430] Process (2)

[0431]

[0432] By appropriately selecting the said synthesis method and appropriately selecting the raw materials used, a compound represented by the formula (H5) having a substituent at the desired position can be synthesized.

[0433] <Preparation method: Example of the preparation method of the compound represented by the formula (H6)>

[0434] Regarding the preparation method of the compound represented by the formula (H6), the first reaction and the second reaction in the preparation method of the compound represented by the formula (H5) can also be applied. That is, the second reaction is a reaction for introducing B (boron) that bonds NH to the c-ring and d-ring. After ortho-metalation of the hydrogen atom of NH using n-butyllithium, sec-butyllithium, tert-butyllithium, or the like, boron trichloride or boron tribromide is added, lithium-boron metal exchange is carried out, and then a Brønsted base such as N,N-diisopropylethylamine is added, whereby a tandem bora-Friedel-Crafts reaction is carried out to obtain the target product. Here, in the second reaction, a Lewis acid such as aluminum trichloride may also be added to promote the reaction.

[0435] 3-1-5-2-5. Compound containing structure represented by formula (H8)

[0436] The compound containing the structure represented by the formula (H8) contains a plurality of, preferably 1 to 5, more preferably 1 to 3, still more preferably 1 to 2, and most preferably 1 structure represented by (H8). In the case of containing a plurality, the said structures are directly bonded to each other by a single bond or bonded through a specific linking group.

[0437]

[0438] In formula (H8), Z is "=C(-H)-" or "=N-", and the H in the said "=C(-H)-" can be replaced by the structure represented by a substituent.

[0439] Examples of the substituent in the case where the H in "=C(-H)-" as Z is substituted include: aryl, heteroaryl, substituted silyl, substituted phosphinyl, and substituted carboxyl, etc.

[0440] Specific examples of the "aryl" as a substituent include: phenyl, tolyl, xylyl, triphenylenyl, fluorenyl, 9,9-dimethylfluorenyl, benzofluorenyl, dibenzofluorenyl, biphenyl, terphenyl, quaterphenyl, etc. Preferably, phenyl, biphenyl, terphenyl, fluorenyl, etc. can be exemplified. As the aryl having a substituent, tolyl, xylyl, 9,9-dimethylfluorenyl, etc. can be exemplified. As shown in the specific examples, the aryl includes both condensed aryl and non-condensed aryl.

[0441] Specific examples of the "heteroaryl" as a substituent include: pyrrolyl, pyrazolyl, pyrazinyl, pyrimidinyl, pyridazinyl, pyridyl, triazinyl, indolyl, isoindolyl, imidazolyl, benzimidazolyl, indazolyl, imidazo[1,2-a]pyridyl, furyl, benzofuryl, isobenzofuryl, dibenzofuryl, azadibenzofuryl, thienyl, benzothienyl, dibenzothienyl, azadibenzothienyl, quinolinyl, isoquinolinyl, quinoxalinyl, quinazolinyl, naphthyridinyl, carbazolyl, azacarbazolyl, phenanthridinyl, acridinyl, phenazinyl, phenothiazinyl, phenoxazinyl, oxazolyl, oxadiazolyl, furazanyl, benzoxazolyl, thiazolyl, thiadiazolyl, benzothiazolyl, triazolyl, tetrazolyl, etc. Preferably, dibenzofuryl, dibenzothienyl, carbazolyl, pyridyl, pyrimidinyl, triazinyl, azadibenzofuryl, and azadibenzothienyl, etc. can be exemplified. Further preferably, dibenzofuryl, dibenzothienyl, azadibenzofuryl, or azadibenzothienyl.

[0442] The "substituted silyl" as a substituent is also preferably a group selected from the group consisting of substituted or unsubstituted trialkylsilyl, substituted or unsubstituted arylalkylsilyl, and substituted or unsubstituted triarylsilyl.

[0443] Specific examples of the substituted or unsubstituted trialkylsilyl group include trimethylsilyl and triethylsilyl. Specific examples of the substituted or unsubstituted arylalkylsilyl group include diphenylmethylsilyl, dimethylphenylmethylsilyl, and phenyldimethylsilyl. Specific examples of the substituted or unsubstituted triarylsilyl group include triphenylsilyl and tritolylsilyl.

[0444] The "substituted phosphinyl group" as a substituent is also preferably a substituted or unsubstituted diarylphosphinyl group. Specific examples of the substituted or unsubstituted diarylphosphinyl group include diphenylphosphine oxide and dimethylphenylphosphine oxide.

[0445] Regarding the "substituted carboxyl group" as a substituent, for example, benzoyloxy can be cited.

[0446] As the linking group for bonding the structures represented by a plurality of formula (H8), derivatives of divalent to tetravalent, divalent to trivalent, or divalent of the aryl or heteroaryl group can be cited.

[0447] Specific examples of the compound containing the structure represented by formula (H8) are shown below.

[0448]

[0449] 3-1-5-2-6. TADF material

[0450] The high-T1 compound can also be a TADF material.

[0451] In the present specification, the TADF material refers to a material as a "thermally activated delayed phosphor". In the "thermally activated delayed phosphor", by reducing the energy difference between the excited singlet state and the excited triplet state, reverse energy transfer from the self-excited triplet state with a low normal migration probability to the excited singlet state is efficiently generated, and luminescence from the singlet state (thermally activated delayed fluorescence, TADF) is exhibited. In normal fluorescence emission, 75% of the triplet excitons generated by current excitation pass through the thermal deactivation path, so they cannot be taken out as fluorescence. On the other hand, in TADF, all excitons can be used for fluorescence emission, and a highly efficient organic EL element can be realized.

[0452] The TADF material is preferably a donor-acceptor type TADF compound (D-A type TADF compound) designed to use an electron-donating substituent called a donor and an electron-accepting substituent called an acceptor to localize the HOMO and LUMO in the molecule to generate efficient reverse intersystem crossing.

[0453] Herein, the "electron-donating substituent" (donor) in this specification refers to the substituent and partial structure locally present in the HOMO orbital of the TADF compound molecule, and the "electron-accepting substituent" (acceptor) refers to the substituent and partial structure locally present in the LUMO orbital of the TADF compound molecule.

[0454] Generally, for TADF compounds using donors or acceptors, due to structural reasons, the spin-orbit coupling (SOC: Spin Orbit Coupling) is large, and the exchange interaction between HOMO and LUMO is small, with ΔE ST being small. Therefore, a very fast reverse intersystem crossing rate can be obtained. On the other hand, for TADF compounds using donors or acceptors, the structural relaxation in the excited state becomes larger (in a certain molecule, the stable structures in the ground state and the excited state are different. Therefore, if the conversion from the ground state to the excited state occurs through external stimulation, the structure then changes to the stable structure in the excited state), thus providing a broad emission spectrum. Therefore, when used as a luminescent material, there is a possibility of reducing the color purity.

[0455] However, by simultaneously using the polycyclic aromatic compound represented by formula (1), the polycyclic aromatic compound represented by formula (1) functions as an emission dopant, and the TADF material functions as an auxiliary dopant, high color purity can be provided. The TADF material only needs to be a compound whose emission spectrum at least partially overlaps with the absorption spectrum of the polycyclic aromatic compound represented by formula (1). The polycyclic aromatic compound represented by formula (1) and the TADF material can both be included in the same layer or in adjacent layers.

[0456] As TADF materials that can be used for such purposes, for example, compounds represented by the following formula (H7) or compounds having the following formula (H7) as a partial structure can be cited.

[0457] ED-Ln-EA (H7)

[0458] In formula (H7), ED is an electron-donating group, Ln is a linking group, EA is an electron-accepting group, and the energy difference (ΔE S1 ) between the lowest excited singlet state energy level (E T1 ) and the lowest excited triplet state energy level (E ST ) of the compound represented by formula (H7) is 0.2 eV or less (Hiroki Uoyama, Kenichi Goushi, Katsuyuki Shizu, Hiroko Nomura, Chihaya Adachi, "Nature", 492, 234 - 238 (2012)). The energy difference (ΔEST ) Preferably, it is 0.15 eV or less, more preferably 0.10 eV or less, and still more preferably 0.08 eV or less.

[0459] As the electron-donating group (donor structure) and electron-accepting group (acceptor structure) used in the TADF material, for example, the structures described in "Chemistry of Materials" (2017, 29, 1946 - 1963) can be used. As ED, for example, functional groups containing sp 3 nitrogen can be cited. More specifically, the following can be cited: groups derived from carbazole, dimethylcarbazole, di-tert-butylcarbazole, dimethoxycarbazole, tetramethylcarbazole, benzofluorocarbazole, benzothienocarbazole, phenyldihydroindolocarbazole, phenylbiscarbazole, biscarbazole, tercarbazole, diphenylcarbazolylamine, tetraphenylcarbazolyl diamine, phenoxazine, dihydrophenoxazine, phenothiazine, dimethyldihydroacridine, diphenylamine, bis(tert-butylphenyl)amine, N1-(4-(diphenylamino)phenyl)-N4,N4-diphenylbenzene-1,4-diamine, dimethyltetraphenyldihydroacridine diamine, tetramethyl-dihydro-indenoacridine, and diphenyl-dihydrodibenzazasiline, etc. In addition, as EA, for example, aromatic rings containing sp 2 nitrogen, CN-substituted aromatic rings, rings having a ketone, and cyano groups can be cited. More specifically, the following can be cited: groups derived from sulfonyldiphenyl, benzophenone, phenylenebis(phenylmethanone), benzonitrile, isonicotinonitrile, phthalonitrile, isophthalonitrile, terephthalonitrile, triazole, oxazole, thiadiazole, benzothiazole, benzobis(thiazole), benzoxazole, benzobis(oxazole), quinoline, benzimidazole, dibenzoquinoxaline, heptazaphenalene, thioxanthene dioxide, dimethylanthrone, anthraquinone, pyridine, 5H-cyclohepta[1,2-b:5,4-b']bipyridine, benzenetricarbonitrile, fluorenedicarbonitrile, pyrazinedicarbonitrile, pyridinedicarbonitrile, dibenzoquinoxalinedicarbonitrile, pyrimidine, phenylpyrimidine, methylpyrimidine, triazine, triphenyltriazine, bis(phenylsulfonyl)benzene, dimethylthioxanthene dioxide, thianthrene tetroxide, and tris(dimethylphenyl)borane, etc. As Ln, for example, single bonds and arylenes can be cited. More specifically, the following can be cited: phenylene, biphenylene, naphthylene, etc. In addition, in any structure, hydrogen can be substituted by alkyl, cycloalkyl, and aryl. Particularly preferred are compounds having at least one selected from carbazole, phenoxazine, acridine, triazine, pyrimidine, pyrazine, thioxanthene, benzonitrile, phthalonitrile, isophthalonitrile, diphenylsulfone, triazole, oxadiazole, thiadiazole, and benzophenone as partial structures.

[0460] In formula (H7), Ln as the linking group functions as a spacer structure that separates the donor partial structure and the acceptor partial structure.

[0461] More specifically, the compound represented by the formula (H7) may be any one of the compounds represented by the formula (H7-1), the formula (H7-2), and the formula (H7-3).

[0462]

[0463] In the formula (H7-1), the formula (H7-2), and the formula (H7-3),

[0464] M are each independently a single bond, -O-, >N-Ar, or >C(-Ar)2, and from the viewpoint of the depth of the HOMO of the partial structure formed and the heights of the lowest excited singlet state energy level and the lowest excited triplet state energy level, a single bond, -O-, or >N-Ar is preferred.

[0465] J is a linking group corresponding to Ln in the formula (H7), and are each independently an arylene group having 6 to 18 carbon atoms. From the viewpoint of the size of the conjugation exuded from the donor partial structure and the acceptor partial structure, an arylene group having 6 to 12 carbon atoms is preferred. More specifically, examples include: phenylene, methylphenylene, and dimethylphenylene.

[0466] Q are each independently =C(-H)- or =N-, and from the viewpoint of the shallowness of the LUMO of the partial structure formed and the heights of the lowest excited singlet state energy level and the lowest excited triplet state energy level, =N- is preferred.

[0467] Ar are each independently hydrogen, an aryl group having 6 to 24 carbon atoms, a heteroaryl group having 2 to 24 carbon atoms, an alkyl group having 1 to 12 carbon atoms, or a cycloalkyl group having 3 to 18 carbon atoms. From the viewpoint of the depth of the HOMO of the partial structure formed and the heights of the lowest excited singlet state energy level and the lowest excited triplet state energy level, hydrogen, an aryl group having 6 to 12 carbon atoms, a heteroaryl group having 2 to 14 carbon atoms, an alkyl group having 1 to 4 carbon atoms, or a cycloalkyl group having 6 to 10 carbon atoms is preferred. More preferably, hydrogen, phenyl, tolyl, xylyl, mesityl, biphenyl, pyridyl, bipyridyl, triazinyl, carbazolyl, dimethylcarbazolyl, di-tert-butylcarbazolyl, benzimidazole, or phenylbenzimidazole is preferred. Further preferably, hydrogen, phenyl, or carbazolyl is preferred.

[0468] m is 1 or 2.

[0469] n is an integer of 2 to (6 - m), and from the viewpoint of steric hindrance, an integer of 4 to (6 - m) is preferred.

[0470] Furthermore, at least one hydrogen in the compound represented by each of the above formulas may be substituted with a halogen or deuterium.

[0471] As the compound represented by the formula (H7), for example, the compounds represented by the following structures can be cited. In addition, * in the structural formula represents the bonding position, "Me" represents a methyl group, and "tBu" represents a tert-butyl group.

[0472]

[0473]

[0474]

[0475]

[0476]

[0477]

[0478]

[0479]

[0480]

[0481] As the compound represented by the formula (H7), among the specific compounds, PIC-TRZ, TXO-TPA, TXO-PhCz, PXZD SO2, ACRD SO2, DTC-DBT, DTAO, 4CzBN, 4CzBN-Ph, 5CzBN, 3Cz2DPhCzBN, 4CzIPN, 2PXZ-TAZ, Cz-TRZ3, BDPCC-TPTA, MA-TA, PA-TA, FA-TA, PXZ-TRZ, DMAC-TRZ, BCzT, DCzTrz, DDCzTrz, spiroAC-TRZ, Ac-HPM, Ac-PPM, Ac-MPM, TCzTrz, TmCzTrz and DCzmCzTrz are preferred.

[0482] 3-1-5-3. Thermally activated delayed phosphor (co-dopant)

[0483] The light-emitting layer may further include a thermally activated delayed phosphor as an auxiliary dopant.

[0484] "Thermally activated delayed phosphor" refers to a compound that can absorb heat energy and undergo reverse intersystem crossing from the lowest excited triplet state to the lowest excited singlet state, and emit delayed fluorescence through radiative deactivation from the lowest excited singlet state. Among them, "thermally activated delayed fluorescence" also includes fluorescence that passes through higher-order triplet states during the excitation process from the lowest excited triplet state to the lowest excited singlet state. Examples include the papers of Monkman et al. from Durham University (NATURE COMMUNICATIONS, 7:13680, DOI: 10.1038 / ncomms13680), Hosokai et al. from the National Institute of Advanced Industrial Science and Technology (Hosokai et al., Sci. Adv. 2017; 3: e1603282), the papers of Sato et al. from Kyoto University (Scientific Reports, 7:4820, DOI: 10.1038 / s41598-017-05007-7) and the conference presentation of Sato et al. from Kyoto University (The 98th Spring Meeting of the Chemical Society of Japan, Presentation No.: 2I4-15, Mechanism of High-Efficiency Luminescence in Organic Electroluminescence Using DABNA as a Luminescent Molecule, Graduate School of Engineering, Kyoto University), the review of Bui et al. (DOI: 10.3762 / bjoc.14.18), the review of Duan et al. (DOI: 10.1063 / 1.5143501), the review of Ding et al. (DOI: 10.1088 / 1674-4926 / 42 / 5 / 050201), and the review of Xie et al. (DOI: 10.1002 / adom.202002204), etc. In the present invention, when measuring the fluorescence lifetime of a sample containing the target compound at 300K, if a delayed fluorescence component is observed, the target compound is determined to be a "thermally activated delayed phosphor". Here, the delayed fluorescence component means that the fluorescence lifetime is 0.1 μsec or more. The fluorescence lifetime can be measured using, for example, a fluorescence lifetime measurement device (manufactured by Hamamatsu Photonics, C11367-01).

[0485] The polycyclic aromatic compound represented by formula (1) can function as an emission dopant, and the "thermally activated delayed phosphor" can function as an auxiliary dopant to assist the luminescence of the polycyclic aromatic compound represented by formula (1).

[0486] In the following description, there are cases where an organic electroluminescent element in which a thermally activated delayed phosphor is used as an auxiliary dopant is referred to as a "TAF element" (TADF Assisting Fluorescence element).

[0487] The "host compound" in the TAF element refers to a compound whose lowest excited singlet energy level obtained from the shoulder on the short-wavelength side of the peak of the fluorescence spectrum is higher than that of the thermally activated delayed phosphor and the emissive dopant serving as the auxiliary dopant.

[0488] In this embodiment, known host compounds can be used as the host compound. For example, compounds having at least one of a carbazole ring and a furan ring can be cited. Among them, compounds in which at least one of a furyl group and a carbazolyl group is bonded to at least one of an arylene group and a heteroarylene group are preferably used. As specific examples, mCP, mCBP, etc. can be cited.

[0489] The lowest excited triplet energy level E(1,T,Sh) obtained from the shoulder on the short-wavelength side of the peak of the phosphorescence spectrum of the host compound is preferably higher than the lowest excited triplet energy levels E(2,T,Sh) and E(3,T,Sh) of the emissive dopant or the auxiliary dopant having the highest lowest excited triplet energy level in the light-emitting layer from the viewpoint of promoting the generation of TADF in the light-emitting layer without hindering it. Specifically, the lowest excited triplet energy level E(1,T,Sh) of the host compound is preferably 0.01 eV or more higher than E(2,T,Sh) and E(3,T,Sh), more preferably 0.03 eV or more higher, and still more preferably 0.1 eV or more higher. In addition, a compound having TADF activity can be used as the host compound.

[0490] The thermally activated delayed phosphor (TADF compound) used in the TAF element is preferably a donor-acceptor type thermally activated delayed phosphor (D-A type TADF compound) designed to localize the HOMO (Highest Occupied Molecular Orbital) and LUMO (Lowest Unoccupied Molecular Orbital) in the molecule using an electron-donating substituent called a donor and an electron-accepting substituent called an acceptor to generate efficient reverse intersystem crossing.

[0491] Here, the "electron-donating substituent" (donor) in this specification refers to the substituent and partial structure in which the HOMO orbital is locally present in the thermally activated delayed phosphor molecule, and the "electron-accepting substituent" (acceptor) refers to the substituent and partial structure in which the LUMO orbital is locally present in the thermally activated delayed phosphor molecule.

[0492] Generally, due to structural reasons, the thermally activated delayed phosphor using a donor or an acceptor has a large spin-orbit coupling (SOC) and a small exchange interaction between the HOMO and the LUMO, ΔES1T1 It is small, so a very fast reverse intersystem crossing speed can be obtained. On the other hand, the structural relaxation of the thermally activated delayed phosphor using a donor or acceptor in the excited state becomes larger (in a certain molecule, the stable structures in the ground state and the excited state are different, so if the conversion from the ground state to the excited state occurs by an external stimulus, the structure then changes to the stable structure in the excited state), thereby providing a broad emission spectrum. Therefore, when used as a luminescent material, there is a possibility of reducing the color purity.

[0493] As the thermally activated delayed phosphor in the TAF element, for example, a compound in which a donor and an acceptor are directly bonded or bonded through a spacer can be used. As the electron-donating group (donor structure) and the electron-accepting group (acceptor structure) used in the thermally activated delayed phosphor of the present invention, for example, the structures described in "Chemistry of Materials" (2017, 29, 1946-1963) can be used. As the donor structure, examples include: carbazole, dimethylcarbazole, di-tert-butylcarbazole, dimethoxycarbazole, tetramethylcarbazole, benzofluorocarbazole, benzothienocarbazole, phenyldihydroindolocarbazole, phenylbiscarbazole, biscarbazole, tercarbazole, diphenylcarbazolylamine, tetraphenylcarbazolyl diamine, phenoxazine, dihydrophenoxazine, phenothiazine, dimethyldihydroacridine, diphenylamine, bis(tert-butylphenyl)amine, N1-(4-(diphenylamino)phenyl)-N4,N4-diphenylbenzene-1,4-diamine, dimethyltetraphenyldihydroacridine diamine, tetramethyl-dihydro-indenoacridine, and diphenyl-dihydrodibenzazasilole. As the acceptor structure, examples include: sulfonyldiphenyl, benzophenone, phenylenebis(phenylmethanone), benzonitrile, isonicotinonitrile, phthalonitrile, isophthalonitrile, terephthalonitrile, benzenetricarbonitrile, triazole, oxazole, thiadiazole, benzothiazole, benzobis(thiazole), benzoxazole, benzobis(oxazole), quinoline, benzimidazole, dibenzoquinoxaline, heptazaphenalene, thioxanthene dioxide, dimethylanthrone, anthraquinone, 5H-cyclohepta[1,2-b:5,4-b']bipyridine, fluorenedicarbonitrile, triphenyltriazine, pyrazinedicarbonitrile, pyrimidine, phenylpyrimidine, methylpyrimidine, pyridinedicarbonitrile, dibenzoquinoxalinedicarbonitrile, bis(phenylsulfonyl)benzene, dimethylthioxanthene dioxide, thianthrene tetroxide, and tris(dimethylphenyl)borane. The compound having thermally activated delayed fluorescence in the TAF element is particularly preferably a compound having at least one selected from carbazole, phenoxazine, acridine, triazine, pyrimidine, pyrazine, thioxanthene, benzonitrile, phthalonitrile, isophthalonitrile, diphenylsulfone, triazole, oxadiazole, thiadiazole, and benzophenone as a partial structure.

[0494] The compound used as an auxiliary dopant in the light-emitting layer of the TAF element is a thermally activated delayed phosphor, preferably a compound whose emission spectrum overlaps at least partially with the absorption peak of the emission dopant.

[0495] 3-1-5-4. Phosphorescent material (co-dopant)

[0496] In the light-emitting layer, a phosphorescent material can also be used as an auxiliary dopant. The phosphorescent material utilizes the intramolecular spin-orbit interaction (heavy atom effect) based on a metal atom to obtain luminescence from the triplet state. As the phosphorescent material as described above, for example, a luminescent metal complex can be used. As the luminescent metal complex, for example, the compounds represented by the following formula (B-1) and the following formula (B-2) can be cited.

[0497]

[0498] In formula (B-1), M is at least one selected from the group consisting of Ir, Pt, Au, Eu, Ru, Re, Ag, and Cu, n is an integer from 1 to 3, and "X-Y" are each independently a bidentate ligand.

[0499] In formula (B-2), M is at least one selected from the group consisting of Pt, Re, and Cu, and "W-X-Y-Z" is a tetradentate ligand.

[0500] In formula (B-1), from the viewpoints of efficiency and lifetime, M is preferably Ir and n is preferably 3.

[0501] In formula (B-2), from the viewpoints of efficiency and lifetime, M is preferably Pt.

[0502] The ligand (X-Y) in formula (B-1) has at least one ligand selected from the group consisting of the following. The ligand (W-X-Y-Z) in formula (B-2) has at least one ligand selected from the group consisting of the following as a part thereof.

[0503]

[0504] In the formula,

[0505] bonded to the central metal M in ---,

[0506] Y are each independently BR e , NR e , PR e , O, S, Se, C=O, S=O, SO2, CR e R f , SiR e R f or GeR e Rf ,

[0507] The aromatic carbon C-H in the ring can also be independently N-substituted respectively.

[0508] R e and R f can also be optionally condensed or bonded to form a ring.

[0509] R a 、R b 、R c and R d can also be independently unsubstituted or substituted with 1 to the maximum number of substitutable substituents.

[0510] R a 、R b 、R c 、R d 、R e and R f are independently hydrogen, deuterium, halide, alkyl, cycloalkyl, heteroalkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, aryl, heteroaryl, nitrile, isonitrile, sulfanyl, or a combination thereof.

[0511] Among them, any two adjacent substituents in R a 、R b 、R c 、and R d can also form a ring or a multidentate ligand by condensation or bonding.

[0512] Regarding the compound represented by formula (B-1), for example, the following can be cited: Ir(ppy)3, Ir(ppy)2(acac), Ir(mppy)3, Ir(PPy)2(m-bppy), BtpIr(acac), Ir(btp)2(acac), Ir(2-phq)3, Hex-Ir(phq)3, Ir(fbi)2(acac), fac-Tris(2-(3-p-xylyl)phenyl)pyridine iridium(III), Eu(dbm)3(Phen), Ir(piq)3, Ir(piq)2(acac), Ir(Fliq)2(acac), Ir(Flq)2(acac), Ru(dtb-bpy)3·2(PF6), Ir(2-phq)3, Ir(BT)2(acac), Ir(DMP)3, Ir(Mphq)3IR(phq)2tpy, fac-Ir(ppy)2Pc, Ir(dp)PQ2, Ir(Dpm)(Piq)2, Hex-Ir(piq)2(acac), Hex-Ir(piq)3, Ir(dmpq)3, Ir(dmpq)2(acac), FPQIrpic, etc.

[0513] As the compound represented by formula (B-1), other compounds that can be cited are as follows.

[0514]

[0515]

[0516] In addition, iridium complexes described in Japanese Patent Laid-Open No. 2006-089398, Japanese Patent Laid-Open No. 2006-080419, Japanese Patent Laid-Open No. 2005-298483, Japanese Patent Laid-Open No. 2005-097263, Japanese Patent Laid-Open No. 2004-111379, U.S. Patent Application Publication No. 2019 / 0051845, etc., or platinum complexes described in Advanced Materials, 26:7116-7121, NPG Asia Materials 13, 53(2021), Applied Physics Letters, 117, 253301(2020), Light-Emitting Diode - An Outlook On the Empirical Features and Its Recent Technological Advancements, Chapter 5 can also be used.

[0517] 3-1-6. Electron injection layer and electron transport layer in organic electroluminescent element

[0518] The electron injection layer 107 functions to efficiently inject the electrons migrated from the cathode 108 into the light-emitting layer 105 or the electron transport layer 106. The electron transport layer 106 functions to efficiently transport the electrons injected from the cathode 108 or the electrons injected from the cathode 108 via the electron injection layer 107 to the light-emitting layer 105. The electron transport layer 106 and the electron injection layer 107 are respectively formed by laminating and mixing one or more than two kinds of electron transport / injection materials, or formed by a mixture of an electron transport / injection material and a polymer binder.

[0519] The so-called electron injection / transport layer is a layer that is responsible for injecting electrons from the cathode and then transporting the electrons. Ideally, it has a high electron injection efficiency and can efficiently transport the injected electrons. Therefore, a material with a large electron affinity, a large electron mobility, excellent stability, and not likely to generate trap impurities during manufacturing and use is preferred. However, when considering the transport balance of holes and electrons, in the case of mainly functioning to efficiently prevent the holes from the anode from recombining and flowing to the cathode side, even if the electron transport ability is not so high, it has the effect of improving the light-emitting efficiency equally to a material with a high electron transport ability. Therefore, the electron injection / transport layer in the present embodiment may also include the function of a layer that can efficiently prevent hole migration.

[0520] As the material (electron transport material) for forming the electron transport layer 106 or the electron injection layer 107, it can be arbitrarily selected from the compounds that have been conventionally used as electron transfer compounds in photoconductive materials and the known compounds used in the electron injection layer and the electron transport layer of organic EL elements.

[0521] As the material used in the electron transport layer or the electron injection layer, it is preferably at least one selected from the following compounds: a compound containing an aromatic ring or a heteroaromatic ring containing one or more atoms selected from carbon, hydrogen, oxygen, sulfur, silicon, and phosphorus; a pyrrole derivative and its condensed ring derivative; and a metal complex having an electron-accepting nitrogen. Specifically, examples include condensed ring aromatic ring derivatives such as naphthalene and anthracene, styryl aromatic ring derivatives represented by 4,4'-bis(diphenylvinyl)biphenyl, perylenequinone derivatives, coumarin derivatives, naphthalenedicarboximide derivatives, quinone derivatives such as anthraquinone or biphenylquinone, phosphorous oxide derivatives, aryl nitrile derivatives, and indole derivatives. As the metal complex having an electron-accepting nitrogen, for example, hydroxyazole complexes such as hydroxyphenyl oxazole complexes, azomethine complexes, tropolone metal complexes, flavonol metal complexes, and benzoquinoline metal complexes can be cited. These materials can be used alone or in combination with different materials.

[0522] In addition, as specific examples of other electron transfer compounds, the following can be cited: pyridine derivatives, naphthalene derivatives, anthracene derivatives, benzofluorene derivatives, phenanthroline derivatives, perinone derivatives, coumarin derivatives, naphthalenedicarboximide derivatives, anthraquinone derivatives, biphenylquinone derivatives, diphenylquinone derivatives, perylene derivatives, oxadiazole derivatives (such as 1,3-bis[(4-tert-butylphenyl)-1,3,4-oxadiazolyl]phenylene), thiophene derivatives, triazole derivatives (such as N-naphthyl-2,5-diphenyl-1,3,4-triazole), thiadiazole derivatives, metal complexes of 8-hydroxyquinoline derivatives, hydroxyquinoline-based metal complexes, quinoxaline derivatives, polymers of quinoxaline derivatives, benzazole compounds, gallium complexes, pyrazole derivatives, perfluorinated phenylene derivatives, triazine derivatives, pyrazine derivatives, benzoquinoline derivatives (such as 2,2'-bis(benzo[h]quinolin-2-yl)-9,9'-spirofluorene), imidazopyridine derivatives, borane derivatives, benzimidazole derivatives (such as tris(N-phenylbenzimidazol-2-yl)benzene), benzoxazole derivatives, benzothiazole derivatives, quinoline derivatives, oligopyridine derivatives such as terpyridine, bipyridine derivatives, terpyridine derivatives (such as 1,3-bis(4'-(2,2':6',2”-terpyridinyl))benzene), naphthyridine derivatives (such as bis(1-naphthyl)-4-(1,8-naphthyridin-2-yl)phenylphosphine oxide), azomethine derivatives, aryl nitrile derivatives, indole derivatives, phosphine oxide derivatives, bisstyryl derivatives, etc.

[0523] In addition, metal complexes having an electron-accepting nitrogen can also be used. For example, the following can be cited: hydroxyazole complexes such as hydroxyquinoline-based metal complexes or hydroxyphenyl oxazole complexes, azomethine complexes, tropolone metal complexes, flavonol metal complexes, and benzoquinoline metal complexes.

[0524] The above materials can be used alone or in combination with different materials.

[0525] Among the above materials, borane derivatives, pyridine derivatives, fluoranthene derivatives, BO-based derivatives, anthracene derivatives, benzofluorene derivatives, phosphine oxide derivatives, pyrimidine derivatives, aryl nitrile derivatives, triazine derivatives, benzimidazole derivatives, phenanthroline derivatives, and hydroxyquinoline-based metal complexes are preferred.

[0526] <Borane derivatives>

[0527] Borane derivatives are, for example, compounds represented by the following formula (ETM-1), and specifically, they are disclosed in Japanese Patent Application Laid-Open No. 2007-27587.

[0528]

[0529] In formula (ETM-1), R 11 and R 12 are each independently at least one of hydrogen, alkyl, cycloalkyl, optionally substituted aryl, substituted silyl, optionally substituted nitrogen-containing heterocycle, or cyano, and R 13 to R 16 are each independently optionally substituted alkyl, optionally substituted cycloalkyl, or optionally substituted aryl, X is optionally substituted arylene, Y is optionally substituted aryl having 16 or less carbon atoms, substituted boron group, or optionally substituted carbazolyl group, and n is each independently an integer of 0 to 3. In addition, examples of the substituent in "optionally substituted" or "substituted" include aryl, heteroaryl, alkyl, or cycloalkyl, etc.

[0530] Among the compounds represented by formula (ETM-1), the compounds represented by the following formula (ETM-1-1) or the following formula (ETM-1-2) are preferred.

[0531]

[0532] In formula (ETM-1-1), R 11 and R 12 are each independently at least one of hydrogen, alkyl, cycloalkyl, optionally substituted aryl, substituted silyl, optionally substituted nitrogen-containing heterocycle, or cyano, and R 13 to R 16 are each independently optionally substituted alkyl, optionally substituted cycloalkyl, or optionally substituted aryl, R 21 and R 22 are each independently at least one of hydrogen, alkyl, cycloalkyl, optionally substituted aryl, substituted silyl, optionally substituted nitrogen-containing heterocycle, or cyano, X 1 is optionally substituted arylene having 20 or less carbon atoms, n is each independently an integer of 0 to 3, and m is each independently an integer of 0 to 4. In addition, examples of the substituent in "optionally substituted" or "substituted" include aryl, heteroaryl, alkyl, or cycloalkyl, etc.

[0533]

[0534] In formula (ETM-1-2), R 11 and R 12 are each independently at least one of hydrogen, alkyl, cycloalkyl, optionally substituted aryl, substituted silyl, optionally substituted nitrogen-containing heterocycle, or cyano, and R 13 to R 16Each is independently a substituted alkyl group, a substituted cycloalkyl group, or a substituted aryl group; X1 is a substituted arylene group having 20 or fewer carbon atoms; and n is independently an integer of 0 to 3. In addition, examples of the substituent in "substituted" or "substitution" include an aryl group, a heteroaryl group, an alkyl group, or a cycloalkyl group, etc.

[0535] As X 1 Specific examples include any of the divalent groups represented by the following formula (X-1) to formula (X-9).

[0536]

[0537] (In each formula, R a is independently an alkyl group, a cycloalkyl group, or a substituted phenyl group, and * represents the bonding position)

[0538] Specific examples of the borane derivative include the following compounds.

[0539]

[0540] The borane derivative can be prepared using known raw materials and known synthesis methods.

[0541] <Pyridine derivative>

[0542] The pyridine derivative is, for example, a compound represented by the following formula (ETM-2), and preferably a compound represented by formula (ETM-2-1) or formula (ETM-2-2).

[0543]

[0544]

[0545] is an n-valent aryl ring (preferably an n-valent benzene ring, naphthalene ring, anthracene ring, fluorene ring, benzo[b]fluorene ring, phenalene ring, phenanthrene ring, or triphenylene ring), and n is an integer of 1 to 4.

[0546] In formula (ETM-2-1), R 11 to R 18 are independently hydrogen, an alkyl group (preferably an alkyl group having 1 to 24 carbon atoms), a cycloalkyl group (preferably a cycloalkyl group having 3 to 12 carbon atoms), or an aryl group (preferably an aryl group having 6 to 30 carbon atoms).

[0547] In formula (ETM-2-2), R 11 and R 12 are independently hydrogen, an alkyl group (preferably an alkyl group having 1 to 24 carbon atoms), a cycloalkyl group (preferably a cycloalkyl group having 3 to 12 carbon atoms), or an aryl group (preferably an aryl group having 6 to 30 carbon atoms), and R11 and R 12 can be bonded to form a ring.

[0548] In each formula, the "pyridine-based substituent" is any one of the following formulas (Py-1) to (Py-15) (* in the formula indicates the bonding position), and the pyridine-based substituents can be independently substituted by an alkyl group having 1 to 4 carbon atoms or a cycloalkyl group having 5 to 10 carbon atoms. As specific examples, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, or tert-butyl, etc. can be cited, and methyl is preferred. In addition, the pyridine-based substituent can be bonded to the anthracene ring or fluorene ring in each formula via a phenylene group or a naphthylene group. The anthracene ring or fluorene ring is bonded.

[0549]

[0550] The pyridine-based substituent is any one of the formulas (Py-1) to (Py-15) (* in the formula indicates the bonding position), and among these, any one of the following formulas (Py-21) to (Py-44) is preferred.

[0551]

[0552] At least one hydrogen in each pyridine derivative can be substituted by deuterium, and in addition, one of the two "pyridine-based substituents" in the formulas (ETM-2-1) and (ETM-2-2) can be substituted by an aryl group.

[0553] As R 11 to R 18 The "alkyl group" in can be either straight-chain or branched-chain. For example, a straight-chain alkyl group having 1 to 24 carbon atoms or a branched-chain alkyl group having 3 to 24 carbon atoms can be cited. The preferred "alkyl group" is an alkyl group having 1 to 18 carbon atoms (a branched-chain alkyl group having 3 to 18 carbon atoms). A more preferred "alkyl group" is an alkyl group having 1 to 12 carbon atoms (a branched-chain alkyl group having 3 to 12 carbon atoms). Further preferred "alkyl group" is an alkyl group having 1 to 6 carbon atoms (a branched-chain alkyl group having 3 to 6 carbon atoms). Particularly preferred "alkyl group" is an alkyl group having 1 to 4 carbon atoms (a branched-chain alkyl group having 3 to 4 carbon atoms).

[0554] As specific "alkyl groups", examples include: methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, isopentyl, neopentyl, tert-pentyl, n-hexyl, 1-methylpentyl, 4-methyl-2-pentyl, 3,3-dimethylbutyl, 2-ethylbutyl, n-heptyl, 1-methylhexyl, n-octyl, tert-octyl, 1-methylheptyl, 2-ethylhexyl, 2-propylpentyl, n-nonyl, 2,2-dimethylheptyl, 2,6-dimethyl-4-heptyl, 3,5,5-trimethylhexyl, n-decyl, n-undecyl, 1-methyldecyl, n-dodecyl, n-tridecyl, 1-hexylheptyl, n-tetradecyl, n-pentadecyl, n-hexadecyl, n-heptadecyl, n-octadecyl, n-eicosyl, etc.

[0555] As the alkyl group having 1 to 4 carbon atoms for substitution in the pyridine-based substituent, the description of the above alkyl group can be cited.

[0556] As R 11 ~R 18 The "cycloalkyl group" in ~R

[0557] Examples of specific "cycloalkyl groups" include: cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, methylcyclopentyl, cycloheptyl, methylcyclohexyl, cyclooctyl, dimethylcyclohexyl, etc.

[0558] As R 11 ~R 18 The "aryl group" in ~R

[0559] Preferred aryl groups have 6 to 30 carbon atoms, more preferred aryl groups have 6 to 18 carbon atoms, still more preferred aryl groups have 6 to 14 carbon atoms, and particularly preferred aryl groups have 6 to 12 carbon atoms.

[0560] Examples of preferred "aryl groups having 6 to 30 carbon atoms" include phenyl, naphthyl, phenanthryl, A group such as a phenyl group or a triphenylene group, and preferably, examples thereof include a phenyl group, a 1-naphthyl group, a 2-naphthyl group, or a phenanthryl group, and particularly preferably, examples thereof include a phenyl group, a 1-naphthyl group, or a 2-naphthyl group.

[0561] R in formula (ETM-2-2) 11 and R 12 can be bonded to form a ring. As a result, a cyclobutane, a cyclopentane, a cyclopentene, a cyclopentadiene, a cyclohexane, a fluorene, an indene, or the like can be spiro-bonded to the 5-membered ring of the fluorene skeleton.

[0562] As specific examples of the pyridine derivative, for example, the following compounds can be cited.

[0563]

[0564] The pyridine derivative can be prepared using known raw materials and known synthesis methods.

[0565] <Fluoranthene derivative>

[0566] The fluoranthene derivative is, for example, a compound represented by the following formula (ETM-3), and specifically, it is disclosed in International Publication No. 2010 / 134352.

[0567]

[0568] In formula (ETM-3), X 12 to X 21 represent hydrogen, a halogen, a linear, branched, or cyclic alkyl group, a linear, branched, or cyclic alkoxy group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted heteroaryl group. Here, as substituents in the case of substitution, examples include an aryl group, a heteroaryl group, an alkyl group, or a cycloalkyl group, etc.

[0569] As specific examples of the fluoranthene derivative, for example, the following compounds can be cited.

[0570]

[0571] <BO-based derivative>

[0572] The BO-based derivative is, for example, a polycyclic aromatic compound represented by the following formula (ETM-4), or a polymer of a polycyclic aromatic compound having a plurality of structures represented by the following formula (ETM-4).

[0573]

[0574] R 1 to R 11Each is independently hydrogen, aryl, heteroaryl, diarylamino, diheteroarylamino, arylheteroarylamino, alkyl, cycloalkyl, alkoxy or aryloxy, and at least one hydrogen among these may be substituted with aryl, heteroaryl, alkyl or cycloalkyl.

[0575] In addition, R 1 ~R 11 Among them, adjacent groups may be bonded to each other and together with the a-ring, b-ring or c-ring form an aryl ring or a heteroaryl ring, and at least one hydrogen in the formed ring may be substituted with aryl, heteroaryl, diarylamino, diheteroarylamino, arylheteroarylamino, alkyl, cycloalkyl, alkoxy or aryloxy, and at least one hydrogen among these may be substituted with aryl, heteroaryl, alkyl or cycloalkyl.

[0576] In addition, at least one hydrogen in the compound or structure represented by the formula (ETM-4) may be substituted with a halogen or deuterium.

[0577] Regarding the description of the substituents or ring-forming forms in the formula (ETM-4), the description of the polycyclic aromatic compound composed of the partial structure represented by the formula (1) can be cited.

[0578] As specific examples of the BO-based derivative, for example, the following compounds can be cited.

[0579]

[0580] The BO-based derivative can be prepared using known raw materials and known synthesis methods.

[0581] <Benzo[fluorene] derivative>

[0582] The benzo[fluorene] derivative is, for example, a compound represented by the following formula (ETM-6).

[0583]

[0584] Ar 1 Each is independently an aryl group having 6 to 20 carbon atoms, and the description of "aryl group having 6 to 20 carbon atoms" in Ar 2 in the formula (ETM-5) can be cited. Preferably, it is an aryl group having 6 to 16 carbon atoms, more preferably an aryl group having 6 to 12 carbon atoms, and particularly preferably an aryl group having 6 to 10 carbon atoms. As specific examples, phenyl, biphenyl, naphthyl, terphenyl, anthryl, acenaphthylenyl, fluorenyl, phenalenyl, phenanthryl, triphenylenyl, pyrenyl, tetracenyl, perylenyl, etc. can be cited.

[0585] Ar 2 Each is independently hydrogen, alkyl (preferably alkyl having 1 to 24 carbon atoms), cycloalkyl (preferably cycloalkyl having 3 to 12 carbon atoms) or aryl (preferably aryl having 6 to 30 carbon atoms), and two Ar 2It can be bonded to form a ring.

[0586] As Ar 2 The "alkyl group" in can be either a straight-chain or a branched-chain one. For example, a straight-chain alkyl group having 1 to 24 carbon atoms or a branched-chain alkyl group having 3 to 24 carbon atoms can be cited. The preferred "alkyl group" is an alkyl group having 1 to 18 carbon atoms (a branched-chain alkyl group having 3 to 18 carbon atoms). A more preferred "alkyl group" is an alkyl group having 1 to 12 carbon atoms (a branched-chain alkyl group having 3 to 12 carbon atoms). Further preferred "alkyl group" is an alkyl group having 1 to 6 carbon atoms (a branched-chain alkyl group having 3 to 6 carbon atoms). A particularly preferred "alkyl group" is an alkyl group having 1 to 4 carbon atoms (a branched-chain alkyl group having 3 to 4 carbon atoms). As specific "alkyl groups", the following can be cited: methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, isopentyl, neopentyl, tert-pentyl, n-hexyl, 1-methylpentyl, 4-methyl-2-pentyl, 3,3-dimethylbutyl, 2-ethylbutyl, n-heptyl, 1-methylhexyl, etc.

[0587] As Ar 2 The "cycloalkyl group" in, for example, a cycloalkyl group having 3 to 12 carbon atoms can be cited. The preferred "cycloalkyl group" is a cycloalkyl group having 3 to 10 carbon atoms. A more preferred "cycloalkyl group" is a cycloalkyl group having 3 to 8 carbon atoms. Further preferred "cycloalkyl group" is a cycloalkyl group having 3 to 6 carbon atoms. As specific "cycloalkyl groups", the following can be cited: cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, methylcyclopentyl, cycloheptyl, methylcyclohexyl, cyclooctyl or dimethylcyclohexyl, etc.

[0588] As Ar 2 The "aryl group" in, the preferred aryl group is an aryl group having 6 to 30 carbon atoms, a more preferred aryl group is an aryl group having 6 to 18 carbon atoms, further preferably an aryl group having 6 to 14 carbon atoms, and particularly preferably an aryl group having 6 to 12 carbon atoms.

[0589] As specific "aryl group having 6 to 30 carbon atoms", the following can be cited: phenyl, naphthyl, acenaphthylenyl, fluorenyl, phenalenyl, phenanthryl, triphenylenyl, pyrenyl, tetraphenylenyl, perylenyl, pentaphenylenyl, etc.

[0590] Two Ar 2 can be bonded to form a ring. As a result, cyclobutane, cyclopentane, cyclopentene, cyclopentadiene, cyclohexane, fluorene or indene, etc. can be spiro-bonded to the 5-membered ring of the fluorene skeleton.

[0591] As a specific example of the said benzo[fluorene] derivative, the following compounds can be cited, for example.

[0592]

[0593] The said benzo[fluorene] derivative can be prepared using known raw materials and known synthesis methods.

[0594] <Phosphine oxide derivative>

[0595] The phosphine oxide derivatives are, for example, compounds represented by the following formula (ETM-7-1). Details are also described in International Publication No. 2013 / 079217 and International Publication No. 2013 / 079678.

[0596]

[0597] R 5 is a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 16 carbon atoms, an aryl group having 6 to 20 carbon atoms, or a heteroaryl group having 5 to 20 carbon atoms.

[0598] R 6 is CN, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 16 carbon atoms, a heteroalkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, a heteroaryl group having 5 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, or an aryloxy group having 6 to 20 carbon atoms.

[0599] R 7 and R 8 are each independently a substituted or unsubstituted aryl group having 6 to 20 carbon atoms or a heteroaryl group having 5 to 20 carbon atoms.

[0600] R 9 is oxygen or sulfur.

[0601] j is 0 or 1, k is 0 or 1, r is an integer from 0 to 4, and q is an integer from 1 to 3.

[0602] Here, examples of the substituent in the case of substitution include an aryl group, a heteroaryl group, an alkyl group, or a cycloalkyl group.

[0603] The phosphine oxide derivatives may be, for example, compounds represented by the following formula (ETM-7-2).

[0604]

[0605] R 1 ~R 3 may be the same or different and are selected from hydrogen, an alkyl group, a cycloalkyl group, an aralkyl group, an alkenyl group, a cycloalkenyl group, an alkynyl group, an alkoxy group, an alkylthio group, a cycloalkylthio group, an aryl ether (arylether group), an arylthioether (arylthioether group), an aryl group, a heterocyclic group, a halogen, a cyano group, a formyl group, a carbonyl group, a carboxyl group, an amino group, a nitro group, a silyl group, and a condensed ring formed between adjacent substituents.

[0606] Ar 1 may be the same or different and is an arylene group or a heteroarylene group. Ar 2 may be the same or different and is an aryl group or a heteroaryl group. Here, Ar 1 and Ar2 At least one of them has a substituent or forms a condensed ring with an adjacent substituent. n is an integer from 0 to 3. When n is 0, there is no unsaturated structural part. When n is 3, there is no R 1 .

[0607] Among these substituents, the so-called alkyl group represents a saturated aliphatic hydrocarbon group such as methyl, ethyl, propyl, butyl, etc. The alkyl group may be unsubstituted or substituted. The substituents when substituted are not particularly limited. For example, alkyl groups, aryl groups, heterocyclic groups, etc. can be cited. This is also common in the following descriptions. In addition, the number of carbon atoms in the alkyl group is not particularly limited. In terms of ease of acquisition or cost, it is usually in the range of 1 to 20.

[0608] In addition, the so-called cycloalkyl group represents a saturated alicyclic hydrocarbon group such as cyclopropyl, cyclohexyl, norbornyl, adamantyl, etc. The cycloalkyl group may be unsubstituted or substituted. The number of carbon atoms in the alkyl part is not particularly limited and is usually in the range of 3 to 20.

[0609] In addition, the so-called aralkyl group represents an aromatic hydrocarbon group separated by an aliphatic hydrocarbon such as benzyl, phenylethyl, etc. Both the aliphatic hydrocarbon and the aromatic hydrocarbon may be unsubstituted or substituted. The number of carbon atoms in the aliphatic part is not particularly limited and is usually in the range of 1 to 20.

[0610] In addition, the so-called alkenyl group represents an unsaturated aliphatic hydrocarbon group containing a double bond such as vinyl, allyl, butadienyl, etc. The alkenyl group may be unsubstituted or substituted. The number of carbon atoms in the alkenyl group is not particularly limited and is usually in the range of 2 to 20.

[0611] In addition, the so-called cycloalkenyl group represents an unsaturated alicyclic hydrocarbon group containing a double bond such as cyclopentenyl, cyclopentadienyl, cyclohexenyl, etc. The cycloalkenyl group may be unsubstituted or substituted.

[0612] In addition, the so-called alkynyl group represents an unsaturated aliphatic hydrocarbon group containing a triple bond such as ethynyl, etc. The alkynyl group may be unsubstituted or substituted. The number of carbon atoms in the alkynyl group is not particularly limited and is usually in the range of 2 to 20.

[0613] In addition, the so-called alkoxy group represents an aliphatic hydrocarbon group separated by an ether bond such as methoxy, etc. The aliphatic hydrocarbon group may be unsubstituted or substituted. The number of carbon atoms in the alkoxy group is not particularly limited and is usually in the range of 1 to 20.

[0614] In addition, the so-called alkylthio group is a group in which the oxygen atom of the ether bond of the alkoxy group is replaced by a sulfur atom.

[0615] In addition, the so-called cycloalkylthio group is a group in which the oxygen atom of the ether bond of the cycloalkoxy group is replaced by a sulfur atom.

[0616] In addition, the so-called aryl ether represents an aromatic hydrocarbon group such as phenoxy group in which an ether bond is interposed, and the aromatic hydrocarbon group may be unsubstituted or substituted. The number of carbon atoms of the aryl ether is not particularly limited, and is usually in the range of 6 to 40.

[0617] In addition, the so-called arylthioether is a group in which the oxygen atom of the ether bond of the aryl ether is substituted with a sulfur atom.

[0618] In addition, the so-called aryl represents an aromatic hydrocarbon group such as phenyl group, naphthyl group, biphenyl group, phenanthryl group, terphenyl group, pyrenyl group, etc. The aryl may be unsubstituted or substituted. The number of carbon atoms of the aryl is not particularly limited, and is usually in the range of 6 to 40.

[0619] In addition, the so-called heterocyclic group represents a cyclic structural group having an atom other than carbon such as furyl group, thienyl group, oxazolyl group, pyridyl group, quinolinyl group, carbazolyl group, etc., and the heterocyclic group may be unsubstituted or substituted. The number of carbon atoms of the heterocyclic group is not particularly limited, and is usually in the range of 2 to 30.

[0620] The so-called halogen represents fluorine, chlorine, bromine, or iodine.

[0621] The formyl group, carbonyl group, and amino group may also include groups substituted with an aliphatic hydrocarbon, alicyclic hydrocarbon, aromatic hydrocarbon, heterocycle, etc.

[0622] In addition, the aliphatic hydrocarbon, alicyclic hydrocarbon, aromatic hydrocarbon, and heterocycle may be unsubstituted or substituted.

[0623] The so-called silyl group represents a silicon compound group such as trimethylsilyl group, and the silyl group may be unsubstituted or substituted. The number of carbon atoms of the silyl group is not particularly limited, and is usually in the range of 3 to 20. In addition, the number of silicon atoms is usually 1 to 6.

[0624] The so-called condensed ring formed between adjacent substituents is, for example, in Ar 1 and R 2 , Ar 1 and R 3 , Ar 2 and R 2 , Ar 2 and R 3 , R 2 and R 3 , Ar 1 and Ar 2 , etc. The formed conjugated or non-conjugated condensed ring. Here, when n is 1, the two Rs 1 may form a conjugated or non-conjugated condensed ring with each other. These condensed rings may contain a nitrogen atom, an oxygen atom, or a sulfur atom in the ring structure, and may further condense with other rings.

[0625] As specific examples of the phosphine oxide derivative, the following compounds can be cited, for example.

[0626]

[0627] The phosphine oxide derivative can be prepared using known raw materials and known synthesis methods.

[0628] <Pyrimidine derivative>

[0629] The pyrimidine derivative is, for example, a compound represented by the following formula (ETM-8), and preferably a compound represented by the following formula (ETM-8-1). Details are also described in International Publication No. 2011 / 021689.

[0630]

[0631] Ar is each independently a substituted aryl group or a substituted heteroaryl group. n is an integer of 1 to 4, preferably an integer of 1 to 3, and more preferably 2 or 3.

[0632] Examples of the "aryl" of the "substituted aryl group" include aryl groups having 6 to 30 carbon atoms, preferably aryl groups having 6 to 24 carbon atoms, more preferably aryl groups having 6 to 20 carbon atoms, and still more preferably aryl groups having 6 to 12 carbon atoms.

[0633] Specific examples of the "aryl" include: phenyl which is a monocyclic aryl group, (2-, 3-, 4-)biphenyl which is a bicyclic aryl group, (1-, 2-)naphthyl which is a condensed bicyclic aryl group, terphenyl (m-terphenyl-2'-yl, m-terphenyl-4'-yl, m-terphenyl-5'-yl, o-terphenyl-3'-yl, o-terphenyl-4'-yl, p-terphenyl-2'-yl, m-terphenyl-2-yl, m-terphenyl-3-yl, m-terphenyl-4-yl, o-terphenyl-2-yl, o-terphenyl-3-yl, o-terphenyl-4-yl, p-terphenyl-2-yl, p-terphenyl-3-yl, p-terphenyl-4-yl) which is a tricyclic aryl group, acenaphthylene-(1-, 3-, 4-, 5-)yl, fluorene-(1-, 2-, 3-, 4-, 9-)yl, phenalene-(1-, 2-)yl, (1-, 2-, 3-, 4-, 9-)phenanthryl which are condensed tricyclic aryl groups, tetraphenyl (5'-phenyl-m-terphenyl-2-yl, 5'-phenyl-m-terphenyl-3-yl, 5'-phenyl-m-terphenyl-4-yl, m-tetraphenyl) which is a tetracyclic aryl group, triphenylene-(1-, 2-)yl, pyrene-(1-, 2-, 4-)yl, naphthacene-(1-, 2-, 5-)yl which are condensed tetracyclic aryl groups, perylene-(1-, 2-, 3-)yl, pentacene-(1-, 2-, 5-, 6-)yl which are condensed pentacyclic aryl groups, etc.

[0634] The "heteroaryl" as the "optionally substituted heteroaryl" may include, for example, heteroaryl having 2 to 30 carbon atoms, preferably heteroaryl having 2 to 25 carbon atoms, more preferably heteroaryl having 2 to 20 carbon atoms, still more preferably heteroaryl having 2 to 15 carbon atoms, and particularly preferably heteroaryl having 2 to 10 carbon atoms. In addition, as the heteroaryl, for example, a heterocycle containing 1 to 5 heteroatoms selected from oxygen, sulfur, and nitrogen as ring-constituting atoms in addition to carbon may be mentioned.

[0635] As specific heteroaryl, for example, furyl, thienyl, pyrrolyl, oxazolyl, isoxazolyl, thiazolyl, isothiazolyl, imidazolyl, pyrazolyl, oxadiazolyl, furazanyl, thiadiazolyl, triazolyl, tetrazolyl, pyridyl, pyrimidinyl, pyridazinyl, pyrazinyl, triazinyl, benzofuryl, isobenzofuryl, benzo[b]thienyl, indolyl, isoindolyl, 1H-indazolyl, benzimidazolyl, benzoxazolyl, benzothiazolyl, 1H-benzotriazolyl, quinolinyl, isoquinolinyl, cinnolinyl, quinazolinyl, quinoxalinyl, phthalazinyl, naphthyridinyl, purinyl, pteridinyl, carbazolyl, acridinyl, phenoxazinyl, phenothiazinyl, phenazinyl, phenoxathiinyl, thianthrenyl, indolizinyl, etc. may be mentioned.

[0636] In addition, the aryl and heteroaryl may be substituted, and may be substituted by, for example, the aryl or heteroaryl.

[0637] As a specific example of the pyrimidine derivative, for example, the following compounds may be mentioned.

[0638]

[0639] The pyrimidine derivative can be prepared using known raw materials and known synthesis methods.

[0640] <Aryl nitrile derivative>

[0641] The aryl nitrile derivative is, for example, a compound represented by the following formula (ETM-9), or a polymer formed by bonding a plurality of the compounds through a single bond or the like. Details are described in the specification of US Application Publication No. 2014 / 0197386.

[0642]

[0643] From the viewpoint of fast electron transport property, Ar ni is preferably a large number of carbon atoms, and from the viewpoint of high T1, Ar ni is preferably a small number of carbon atoms. Specifically, when used in a layer adjacent to the light-emitting layer, it is preferably high in T1, so Ar niIt is an aryl group having 6 to 20 carbon atoms, preferably an aryl group having 6 to 14 carbon atoms, more preferably an aryl group having 6 to 10 carbon atoms. In addition, regarding the substitution number n of the nitrile group, from the viewpoint of high T1, it is preferably large, and from the viewpoint of high S1, it is preferably small. Specifically, the substitution number n of the nitrile group is an integer of 1 to 4, preferably an integer of 1 to 3, more preferably an integer of 1 to 2, and still more preferably 1.

[0644] Ars are each independently a substituted aryl group or a substituted heteroaryl group. From the viewpoints of high S1 and high T1, a donor heteroaryl group is preferred. Since it is used as an electron transport layer, the donor heteroaryl group is preferably small. From the viewpoint of charge transport property, an aryl group or heteroaryl group having a large number of carbon atoms is preferred, and it is preferred to have a large number of substituents. Specifically, the substitution number m of Ar is an integer of 1 to 4, preferably an integer of 1 to 3, more preferably 1 to 2.

[0645] Examples of the "aryl group" of the "substituted aryl group" include aryl groups having 6 to 30 carbon atoms, preferably aryl groups having 6 to 24 carbon atoms, more preferably aryl groups having 6 to 20 carbon atoms, and still more preferably aryl groups having 6 to 12 carbon atoms.

[0646] Specific examples of the "aryl group" include: phenyl which is a monocyclic aryl group, (2-, 3-, 4-) biphenyl which is a bicyclic aryl group, (1-, 2-) naphthyl which is a condensed bicyclic aryl group, terphenyl (m-terphenyl-2'-yl, m-terphenyl-4'-yl, m-terphenyl-5'-yl, o-terphenyl-3'-yl, o-terphenyl-4'-yl, p-terphenyl-2'-yl, m-terphenyl-2-yl, m-terphenyl-3-yl, m-terphenyl-4-yl, o-terphenyl-2-yl, o-terphenyl-3-yl, o-terphenyl-4-yl, p-terphenyl-2-yl, p-terphenyl-3-yl, p-terphenyl-4-yl) which is a tricyclic aryl group, acenaphthylene-(1-, 3-, 4-, 5-)yl, fluorene-(1-, 2-, 3-, 4-, 9-)yl, phenalene-(1-, 2-)yl, (1-, 2-, 3-, 4-, 9-)phenanthryl which are condensed tricyclic aryl groups, tetraphenyl (5'-phenyl-m-terphenyl-2-yl, 5'-phenyl-m-terphenyl-3-yl, 5'-phenyl-m-terphenyl-4-yl, m-tetraphenyl) which is a tetracyclic aryl group, triphenylene-(1-, 2-)yl, pyrene-(1-, 2-, 4-)yl, tetracene-(1-, 2-, 5-)yl which are condensed tetracyclic aryl groups, perylene-(1-, 2-, 3-)yl, pentacene-(1-, 2-, 5-, 6-)yl and the like which are condensed pentacyclic aryl groups.

[0647] The "heteroaryl" as the "optionally substituted heteroaryl" may include, for example, a heteroaryl having 2 to 30 carbon atoms, preferably a heteroaryl having 2 to 25 carbon atoms, more preferably a heteroaryl having 2 to 20 carbon atoms, still more preferably a heteroaryl having 2 to 15 carbon atoms, and particularly preferably a heteroaryl having 2 to 10 carbon atoms. In addition, examples of the heteroaryl include a heterocycle containing 1 to 5 heteroatoms selected from oxygen, sulfur, and nitrogen as ring-constituting atoms in addition to carbon.

[0648] Specific examples of the heteroaryl include: furyl, thienyl, pyrrolyl, oxazolyl, isoxazolyl, thiazolyl, isothiazolyl, imidazolyl, pyrazolyl, oxadiazolyl, furazanyl, thiadiazolyl, triazolyl, tetrazolyl, pyridyl, pyrimidinyl, pyridazinyl, pyrazinyl, triazinyl, benzofuryl, isobenzofuryl, benzo[b]thienyl, indolyl, isoindolyl, 1H-indazolyl, benzimidazolyl, benzoxazolyl, benzothiazolyl, 1H-benzotriazolyl, quinolinyl, isoquinolinyl, cinnolinyl, quinazolinyl, quinoxalinyl, phthalazinyl, naphthyridinyl, purinyl, pteridinyl, carbazolyl, acridinyl, phenoxazinyl, phenothiazinyl, phenazinyl, phenoxathiinyl, thianthrenyl, indolizinyl, etc.

[0649] In addition, the aryl and heteroaryl may be substituted, and may be substituted by, for example, the aryl or heteroaryl.

[0650] The aryl nitrile derivative may be a polymer formed by bonding compounds represented by a plurality of formulae (ETM-9) through a single bond or the like. In this case, in addition to the single bond, it may also be bonded through an aryl ring (preferably a polyvalent benzene ring, naphthalene ring, anthracene ring, fluorene ring, benzofluorene ring, phenalene ring, phenanthrene ring, or triphenylene ring).

[0651] Specific examples of the aryl nitrile derivative include the following compounds.

[0652]

[0653] The aryl nitrile derivative can be prepared using known raw materials and known synthesis methods.

[0654] <Triazine derivative>

[0655] The triazine derivative is, for example, a compound represented by the following formula (ETM-10), and preferably a compound represented by the following formula (ETM-10-1). Details are described in the specification of U.S. Patent Application Publication No. 2011 / 0156013.

[0656]

[0657] Ar is independently a substituted aryl or a substituted heteroaryl. n is an integer of 1 to 3, preferably 2 or 3.

[0658] The "aryl" as the "substitutable aryl" may include, for example, aryl groups having 6 to 30 carbon atoms, preferably aryl groups having 6 to 24 carbon atoms, more preferably aryl groups having 6 to 20 carbon atoms, and still more preferably aryl groups having 6 to 12 carbon atoms.

[0659] Specific examples of the "aryl" include: phenyl as a monocyclic aryl, (2-, 3-, 4-)biphenyl as a bicyclic aryl, (1-, 2-)naphthyl as a condensed bicyclic aryl, terphenyl (m-terphenyl-2'-yl, m-terphenyl-4'-yl, m-terphenyl-5'-yl, o-terphenyl-3'-yl, o-terphenyl-4'-yl, p-terphenyl-2'-yl, m-terphenyl-2-yl, m-terphenyl-3-yl, m-terphenyl-4-yl, o-terphenyl-2-yl, o-terphenyl-3-yl, o-terphenyl-4-yl, p-terphenyl-2-yl, p-terphenyl-3-yl, p-terphenyl-4-yl) as a tricyclic aryl, acenaphthylen-(1-, 3-, 4-, 5-)yl, fluoren-(1-, 2-, 3-, 4-, 9-)yl, phenalen-(1-, 2-)yl, (1-, 2-, 3-, 4-, 9-)phenanthryl as a condensed tricyclic aryl, 5'-phenyl-m-terphenyl-2-yl, 5'-phenyl-m-terphenyl-3-yl, 5'-phenyl-m-terphenyl-4-yl, m-quaterphenyl as a tetracyclic aryl, triphenylene-(1-, 2-)yl, pyrene-(1-, 2-, 4-)yl, naphthacene-(1-, 2-, 5-)yl as a condensed tetracyclic aryl, perylene-(1-, 2-, 3-)yl, pentacene-(1-, 2-, 5-, 6-)yl as a condensed pentacyclic aryl, etc.

[0660] The "heteroaryl" as the "substitutable heteroaryl" may include, for example, heteroaryl groups having 2 to 30 carbon atoms, preferably heteroaryl groups having 2 to 25 carbon atoms, more preferably heteroaryl groups having 2 to 20 carbon atoms, still more preferably heteroaryl groups having 2 to 15 carbon atoms, and particularly preferably heteroaryl groups having 2 to 10 carbon atoms. In addition, examples of the heteroaryl include heterocycles containing 1 to 5 heteroatoms selected from oxygen, sulfur, and nitrogen as ring-constituting atoms in addition to carbon.

[0661] As specific heteroaryl groups, for example, the following can be mentioned: furyl, thienyl, pyrrolyl, oxazolyl, isoxazolyl, thiazolyl, isothiazolyl, imidazolyl, pyrazolyl, oxadiazolyl, furazanyl, thiadiazolyl, triazolyl, tetrazolyl, pyridyl, pyrimidinyl, pyridazinyl, pyrazinyl, triazinyl, benzofuryl, isobenzofuryl, benzo[b]thienyl, indolyl, isoindolyl, 1H-indazolyl, benzimidazolyl, benzoxazolyl, benzothiazolyl, 1H-benzotriazolyl, quinolinyl, isoquinolinyl, cinnolinyl, quinazolinyl, quinoxalinyl, phthalazinyl, naphthyridinyl, purinyl, pteridinyl, carbazolyl, acridinyl, phenoxazinyl, phenothiazinyl, phenazinyl, phenoxathiinyl, thianthrenyl, indolizinyl, etc.

[0662] In addition, the aryl group and heteroaryl group may be substituted, and may be substituted by, for example, the aryl group or heteroaryl group.

[0663] As specific examples of the triazine derivative, for example, the following compounds can be mentioned.

[0664]

[0665] The triazine derivative can be prepared using known raw materials and known synthesis methods.

[0666] <Benzimidazole derivative>

[0667] The benzimidazole derivative is, for example, a compound represented by the following formula (ETM-11).

[0668]

[0669] is an n-valent aryl ring (preferably an n-valent benzene ring, naphthalene ring, anthracene ring, fluorene ring, benzofluorene ring, phenalene ring, phenanthrene ring or triphenylene ring), n is an integer of 1 to 4, and the "benzimidazole-based substituent" is a substituent obtained by substituting the pyridyl group in the "pyridine-based substituent" of formula (ETM-2), formula (ETM-2-1) and formula (ETM-2-2) with the following benzimidazolyl group (wherein, * represents the bonding position), and at least one hydrogen in the benzimidazole derivative may be substituted with deuterium.

[0670]

[0671] R in the benzimidazolyl group 11 is hydrogen, an alkyl group having 1 to 24 carbon atoms, a cycloalkyl group having 3 to 12 carbon atoms or an aryl group having 6 to 30 carbon atoms, and the description of R in formula (ETM-2-1) and formula (ETM-2-2) can be cited. 11 description.

[0672] More preferably, it is an anthracene ring or a fluorene ring. In this case, the structure can refer to the description in Formula (ETM-2-1) or Formula (ETM-2-2), and R in each formula 11 ~R 18 can refer to the description in Formula (ETM-2-1) or Formula (ETM-2-2). In addition, in Formula (ETM-2-1) or Formula (ETM-2-2), it is described in the form of having two pyridine-based substituents bonded. However, when these are replaced with benzimidazole-based substituents, two pyridine-based substituents can be replaced by benzimidazole-based substituents (i.e., n = 2), or any one of the pyridine-based substituents can be replaced by a benzimidazole-based substituent and the other pyridine-based substituent can be replaced by R 11 ~R 18 (i.e., n = 1). Furthermore, for example, at least one of R 11 ~R 18 in Formula (ETM-2-1) can be replaced by a benzimidazole-based substituent and the "pyridine-based substituent" can be replaced by R 11 ~R 18 .

[0673] As specific examples of the benzimidazole derivative, for example, 1-phenyl-2-(4-(10-phenylanthracen-9-yl)phenyl)-1H-benzo[d]imidazole, 2-(4-(10-(naphthalen-2-yl)anthracen-9-yl)phenyl)-1-phenyl-1H-benzo[d]imidazole, 2-(3-(10-(naphthalen-2-yl)anthracen-9-yl)phenyl)-1-phenyl-1H-benzo[d]imidazole, 5-(10-(naphthalen-2-yl)anthracen-9-yl)-1,2-diphenyl-1H-benzo[d]imidazole, 1-(4-(10-(naphthalen-2-yl)anthracen-9-yl)phenyl)-2-phenyl-1H-benzo[d]imidazole, 2-(4-(9,10-di(naphthalen-2-yl)anthracen-2-yl)phenyl)-1-phenyl-1H-benzo[d]imidazole, 1-(4-(9,10-di(naphthalen-2-yl)anthracen-2-yl)phenyl)-2-phenyl-1H-benzo[d]imidazole, 5-(9,10-di(naphthalen-2-yl)anthracen-2-yl)-1,2-diphenyl-1H-benzo[d]imidazole, etc. can be cited.

[0674]

[0675] The benzimidazole derivative can be prepared using known raw materials and known synthesis methods.

[0676] <Phenanthroline derivative>

[0677] The phenanthroline derivative is, for example, a compound represented by the following Formula (ETM-12) or Formula (ETM-12-1). The details are described in International Publication No. 2006 / 021982.

[0678]

[0679] is an n-valent aryl ring (preferably an n-valent benzene ring, naphthalene ring, anthracene ring, fluorene ring, benzofluorene ring, phenalene ring, phenanthrene ring or triphenylene ring), where n is an integer from 1 to 4.

[0680] Each of the various Rs 11 ~R 18 are each independently hydrogen, alkyl (preferably alkyl having 1 to 24 carbon atoms), cycloalkyl (preferably cycloalkyl having 3 to 12 carbon atoms) or aryl (preferably aryl having 6 to 30 carbon atoms). Additionally, in formula (ETM-12-1), any one of R 11 ~R 18 becomes a bonding arm to which is an aryl ring.

[0681] At least one hydrogen in each phenanthroline derivative may be substituted with deuterium.

[0682] Regarding the alkyl, cycloalkyl and aryl in R 11 ~R 18 , the description of R 11 ~R 18 in formula (ETM-2) can be referred to. Additionally, regarding in addition to the above examples, for example, the following structural formulas can be listed. Furthermore, each R in the following structural formulas is independently hydrogen, methyl, ethyl, isopropyl, cyclohexyl, phenyl, 1-naphthyl, 2-naphthyl, biphenyl or terphenyl, and * represents the bonding position.

[0683]

[0684] As specific examples of the phenanthroline derivatives, for example, 4,7-diphenyl-1,10-phenanthroline, 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline, 9,10-bis(1,10-phenanthrolin-2-yl)anthracene, 2,6-bis(1,10-phenanthrolin-5-yl)pyridine, 1,3,5-tris(1,10-phenanthrolin-5-yl)benzene, 9,9'-difluoro-bis(1,10-phenanthrolin-5-yl), 2,9-dimethyl-4,7-biphenyl-1,10-phenanthroline (bathocuproine), 1,3-bis(2-phenyl-1,10-phenanthrolin-9-yl)benzene or compounds represented by the following structural formulas, etc. can be listed.

[0685]

[0686] The phenanthroline derivatives can be prepared using known raw materials and known synthesis methods.

[0687] <Hydroxyquinoline-based metal complex>

[0688] The hydroxyquinoline-based metal complex is, for example, a compound represented by the following formula (ETM-13).

[0689]

[0690] In the formula, R 1 ~R 6 are each independently hydrogen, fluorine, alkyl, cycloalkyl, aralkyl, alkenyl, cyano, alkoxy, or aryl, M is Li, Al, Ga, Be, or Zn, and n is an integer of 1 to 3.

[0691] As specific examples of the hydroxyquinoline-based metal complexes, the following can be cited: lithium 8-hydroxyquinolate, tris(8-hydroxyquinoline)aluminum, tris(4-methyl-8-hydroxyquinoline)aluminum, tris(5-methyl-8-hydroxyquinoline)aluminum, tris(3,4-dimethyl-8-hydroxyquinoline)aluminum, tris(4,5-dimethyl-8-hydroxyquinoline)aluminum, tris(4,6-dimethyl-8-hydroxyquinoline)aluminum, bis(2-methyl-8-hydroxyquinoline)(phenol)aluminum, bis(2-methyl-8-hydroxyquinoline)(2-methylphenol)aluminum, bis(2-methyl-8-hydroxyquinoline)(3-methylphenol)aluminum, bis(2-methyl-8-hydroxyquinoline)(4-methylphenol)aluminum, bis(2-methyl-8-hydroxyquinoline)(2-phenylphenol)aluminum, bis(2-methyl-8-hydroxyquinoline)(3-phenylphenol)aluminum, bis(2-methyl-8-hydroxyquinoline)(4-phenylphenol)aluminum, bis(2-methyl-8-hydroxyquinoline)(2,3-dimethylphenol)aluminum, bis(2-methyl-8-hydroxyquinoline)(2,6-dimethylphenol)aluminum, bis(2-methyl-8-hydroxyquinoline)(3,4-dimethylphenol)aluminum, bis(2-methyl-8-hydroxyquinoline)(3,5-dimethylphenol)aluminum, bis(2-methyl-8-hydroxyquinoline)(3,5-di-tert-butylphenol)aluminum, bis(2-methyl-8-hydroxyquinoline)(2,6-diphenylphenol)aluminum, bis(2-methyl-8-hydroxyquinoline)(2,4,6-triphenylphenol)aluminum, bis(2-methyl-8-hydroxyquinoline)(2,4,6-trimethylphenol)aluminum, bis(2-methyl-8-hydroxyquinoline)(2,4,5,6-tetramethylphenol)aluminum, bis(2-methyl-8-hydroxyquinoline)(1-naphthol)aluminum, bis(2-methyl-8-hydroxyquinoline)(2-naphthol)aluminum, bis(2,4-dimethyl-8-hydroxyquinoline)(2-phenylphenol)aluminum, bis(2,4-dimethyl-8-hydroxyquinoline)(3-phenylphenol)aluminum, bis(2,4-dimethyl-8-hydroxyquinoline)(4-phenylphenol)aluminum, bis(2,4-dimethyl-8-hydroxyquinoline)(3,5-dimethylphenol)aluminum, bis(2,4-dimethyl-8-hydroxyquinoline)(3,5-di-tert-butylphenol)aluminum, bis(2-methyl-8-hydroxyquinoline)aluminum-μ-oxo-bis(2-methyl-8-hydroxyquinoline)aluminum, bis(2,4-dimethyl-8-hydroxyquinoline)aluminum-μ-oxo-bis(2,Aluminum bis(4-dimethyl-8-hydroxyquinoline), aluminum bis(2-methyl-4-ethyl-8-hydroxyquinoline)-μ-oxo-bis(2-methyl-4-ethyl-8-hydroxyquinoline), aluminum bis(2-methyl-4-methoxy-8-hydroxyquinoline)-μ-oxo-bis(2-methyl-4-methoxy-8-hydroxyquinoline), aluminum bis(2-methyl-5-cyano-8-hydroxyquinoline)-μ-oxo-bis(2-methyl-5-cyano-8-hydroxyquinoline), aluminum bis(2-methyl-5-trifluoromethyl-8-hydroxyquinoline)-μ-oxo-bis(2-methyl-5-trifluoromethyl-8-hydroxyquinoline), beryllium bis(10-hydroxybenzo[h]quinoline), etc.,

[0692] The hydroxyquinoline-based metal complex can be prepared using known raw materials and known synthesis methods.

[0693] <Thiazole derivatives and benzothiazole derivatives>

[0694] Thiazole derivatives are, for example, compounds represented by the following formula (ETM-14-1).

[0695] Φ-(thiazole-based substituent)n(ETM-14-1)

[0696] Benzothiazole derivatives are, for example, compounds represented by the following formula (ETM-14-2).

[0697] Φ-(benzothiazole-based substituent)n(ETM-14-2)

[0698] In each formula, Φ is an n-valent aryl ring (preferably an n-valent benzene ring, naphthalene ring, anthracene ring, fluorene ring, benzofluorene ring, phenalene ring, phenanthrene ring or triphenylene ring), n is an integer from 1 to 4, and the "thiazole-based substituent" or "benzothiazole-based substituent" is a substituent formed by substituting the pyridyl group in the "pyridine-based substituent" of formula (ETM-2), formula (ETM-2-1) and formula (ETM-2-2) with the following thiazolyl group or benzothiazolyl group (* indicates the bonding position). At least one hydrogen in the thiazole derivative and the benzothiazole derivative may be substituted with deuterium.

[0699]

[0700] Φ is further preferably an anthracene ring or a fluorene ring. In this case, the structure can refer to the description in formula (ETM-2-1) or formula (ETM-2-2). R 11 ~R 18 can refer to the description in formula (ETM-2-1) or formula (ETM-2-2). Additionally, in formula (ETM-2-1) or formula

[0701] (ETM-2-2) is described in the form of having two pyridyl substituents bonded, but when these are replaced with thiazole substituents (or benzothiazole substituents), two pyridyl substituents can be replaced by thiazole substituents (or benzothiazole substituents) (i.e., n = 2), or one pyridyl substituent can be replaced by a thiazole substituent (or benzothiazole substituent) and the other pyridyl substituent can be replaced by R 11 ~R 18 . Further, for example, at least one of R 11 ~R 18 in formula (ETM-2-1) can be replaced by a thiazole substituent (or benzothiazole substituent) and the "pyridyl substituent" can be replaced by R 11 ~R 18 .

[0702] These thiazole derivatives or benzothiazole derivatives can be prepared using known raw materials and known synthesis methods.

[0703] <Silole derivative>

[0704] The silole derivative is, for example, a compound represented by the following formula (ETM-15). Details are described in Japanese Patent Laid-Open No. 9-194487.

[0705]

[0706] X and Y are each independently an alkyl group, a cycloalkyl group, an alkenyl group, an alkynyl group, an alkoxy group, an alkenyloxy group, an alkynyloxy group, an aryl group, or a heteroaryl group, and these can be substituted. For details of these groups, reference can be made to the description in formula (1) and the description in formula (ETM-7-2). In addition, the alkenyloxy group and the alkynyloxy group are groups in which the alkyl part of the alkoxy group is replaced by an alkenyl group or an alkynyl group, and for details of these alkenyl groups and alkynyl groups, reference can be made to the description in formula (ETM-7-2).

[0707] In addition, X and Y, both being alkyl groups, can be bonded to form a ring.

[0708] R 1 ~R 4Each independently is hydrogen, halogen, alkyl, cycloalkyl, alkoxy, aryloxy, amino, alkylcarbonyl, arylcarbonyl, alkoxycarbonyl, aryloxycarbonyl, azo, alkylcarbonyloxy, arylcarbonyloxy, alkoxycarbonyloxy, aryloxycarbonyloxy, sulfinyl, sulfonyl, sulfanyl, silyl, carbamoyl, aryl, heteroaryl, alkenyl, alkynyl, nitro, formyl, nitroso, formyloxy, isocyano, cyanate, isocyanate, thiocyanate, isothiocyanate, or cyano, which may be substituted with alkyl, cycloalkyl, aryl or halogen, or may form a condensed ring between adjacent substituents.

[0709] Regarding R 1 ~R 4 For the details of halogen, alkyl, cycloalkyl, alkoxy, aryloxy, amino, aryl, heteroaryl, alkenyl and alkynyl in R

[0710] Regarding R 1 ~R 4 For the details of alkyl, aryl and alkoxy in alkylcarbonyl, arylcarbonyl, alkoxycarbonyl, aryloxycarbonyl, alkylcarbonyloxy, arylcarbonyloxy, alkoxycarbonyloxy and aryloxycarbonyloxy in R

[0711] As the silyl group, there can be mentioned silyl group, and a group in which at least one of the three hydrogens of the silyl group is independently substituted with aryl, alkyl or cycloalkyl, preferably a trisubstituted silyl group, and examples include: triarylsilyl, trialkylsilyl, tricycloalkylsilyl, dialkylcycloalkylsilyl and alkyl dicycloalkylsilyl, etc. For the details of aryl, alkyl and cycloalkyl in these, the description in formula (1) can be cited.

[0712] The condensed ring formed between adjacent substituents is, for example, a conjugated or non-conjugated condensed ring formed between R 1 and R 2 , R 2 and R 3 , R 3 and R 4 etc. These condensed rings may contain nitrogen atoms, oxygen atoms, sulfur atoms in the ring structure, and may further condense with other rings.

[0713] Among them, preferably when R 1 and R 4 are phenyl, X and Y are not alkyl or phenyl. In addition, it is preferably not to satisfy simultaneously that when R 1 and R 4 are thienyl, X and Y are alkyl and R 2 and R 3is an alkyl group, an aryl group, an alkenyl group or R 2 bonded to R 3 to form a cycloalkyl group structure of a ring. Additionally, preferably when R 1 and R 4 are silyl groups, R 2 , R 3 , X and Y are each independently not hydrogen or an alkyl group having 1 to 6 carbon atoms. Additionally, preferably when there is a structure in which a benzene ring is condensed in R 1 and R 2 , X and Y are not alkyl groups and phenyl groups.

[0714] These silole derivatives can be prepared using known raw materials and known synthesis methods.

[0715] <Oxazoline derivative>

[0716] The oxazoline derivative is, for example, a compound represented by the following formula (ETM-16). Details are described in International Publication No. 2017 / 014226.

[0717]

[0718] In formula (ETM-16),

[0719] Φ is an m-valent group derived from an aromatic hydrocarbon having 6 to 40 carbon atoms or an m-valent group derived from an aromatic heterocycle having 2 to 40 carbon atoms, and at least one hydrogen of Φ can be substituted with an alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 3 to 14 carbon atoms, an aryl group having 6 to 18 carbon atoms or a heteroaryl group having 2 to 18 carbon atoms,

[0720] Y are each independently -O-, -S- or >N-Ar, Ar is an aryl group having 6 to 12 carbon atoms or a heteroaryl group having 2 to 12 carbon atoms, and at least one hydrogen of Ar can be substituted with an alkyl group having 1 to 4 carbon atoms, a cycloalkyl group having 5 to 10 carbon atoms, an aryl group having 6 to 12 carbon atoms or a heteroaryl group having 2 to 12 carbon atoms, R 1 to R 5 are each independently hydrogen, an alkyl group having 1 to 4 carbon atoms or a cycloalkyl group having 5 to 10 carbon atoms, wherein Ar in the >N-Ar and any one of the R 1 to R 5 is the site bonded to L,

[0721] L is each independently selected from the group consisting of a divalent group represented by the following formula (L-1) and a divalent group represented by the following formula (L-2),

[0722]

[0723] In formula (L-1), X 1 to X 6 are each independently =CR6 - or =N-, X 1 ~X 6 At least two of them are =CR 6 -, X 1 ~X 6 Two of =CR 6 R in - 6 Is the part bonded to the Φ or oxazoline ring, and =CR other than that 6 R in - 6 Is hydrogen,

[0724] In formula (L-2), X 7 ~X 14 Are each independently =CR 6 - or =N-, X 7 ~X 14 At least two of them are =CR 6 -, X 7 ~X 14 Two of =CR 6 R in - 6 Is the part bonded to the Φ or oxazoline ring, and =CR other than that 6 R in - 6 Is hydrogen,

[0725] At least one hydrogen of L can be substituted by an alkyl group having 1 to 4 carbon atoms, a cycloalkyl group having 5 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, or a heteroaryl group having 2 to 10 carbon atoms.

[0726] m is an integer of 1 to 4. When m is 2 to 4, the groups formed by the oxazoline ring and L can be the same or different, and

[0727] At least one hydrogen in the compound represented by formula (ETM-16) can be substituted by deuterium.

[0728] Specific oxazoline derivatives are compounds represented by the following formula (ETM-16-1) or formula (ETM-16-2).

[0729]

[0730] In formula (ETM-16-1) and formula (ETM-16-2),

[0731] Φ is an m-valent group derived from an aromatic hydrocarbon having 6 to 40 carbon atoms or an m-valent group derived from an aromatic heterocycle having 2 to 40 carbon atoms. At least one hydrogen of Φ can be substituted by an alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 3 to 14 carbon atoms, an aryl group having 6 to 18 carbon atoms, or a heteroaryl group having 2 to 18 carbon atoms.

[0732] In formula (ETM-16-1), Y is independently -O-, -S- or >N-Ar respectively, Ar is an aryl group having 6 to 12 carbon atoms or a heteroaryl group having 2 to 12 carbon atoms, and at least one hydrogen of Ar may be substituted by an alkyl group having 1 to 4 carbon atoms, a cycloalkyl group having 5 to 10 carbon atoms, an aryl group having 6 to 12 carbon atoms or a heteroaryl group having 2 to 12 carbon atoms.

[0733] In formula (ETM-16-1), R 1 ~R 4 are independently hydrogen, an alkyl group having 1 to 4 carbon atoms or a cycloalkyl group having 5 to 10 carbon atoms respectively, wherein, R 1 is the same as R 2 , and R 3 is the same as R 4 .

[0734] In formula (ETM-16-2), R 1 ~R 5 are independently hydrogen, an alkyl group having 1 to 4 carbon atoms or a cycloalkyl group having 5 to 10 carbon atoms respectively, wherein, R 1 is the same as R 2 , and R 3 is the same as R 4 .

[0735] In formula (ETM-16-1) and formula (ETM-16-2),

[0736] L is independently selected from the group consisting of a divalent group represented by the following formula (L-1) and a divalent group represented by the following formula (L-2):

[0737]

[0738] In formula (L-1), X 1 ~X 6 are independently =CR 6 - or =N-, and at least two of X 1 ~X 6 are =CR 6 -, and R 1 ~X 6 in two =CR 6 - is the bonding site with Φ or the oxazoline ring, and R 6 in the other =CR 6 - is hydrogen. 6

[0739] In formula (L-2), X 7 ~X 14 are independently =CR 6 - or =N-, and at least two of X 7 ~X 14 are =CR6 -, X 7 ~X 14 Two =CR in 6 R in - 6 Is the part bonded to the Φ or oxazoline ring, and =CR other than that 6 R in - 6 Is hydrogen,

[0740] At least one hydrogen of L can be substituted by an alkyl group having 1 to 4 carbon atoms, a cycloalkyl group having 5 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, or a heteroaryl group having 2 to 10 carbon atoms.

[0741] m is an integer from 1 to 4. When m is 2 to 4, the groups formed by the oxazoline ring and L can be the same or different. Moreover,

[0742] At least one hydrogen in the compound represented by formula (ETM-16-1) or formula (ETM-16-2) can be substituted by deuterium.

[0743] Preferably, Φ is selected from the group consisting of monovalent groups represented by the following formula (Φ1-1) to formula (Φ1-18), divalent groups represented by the following formula (Φ2-1) to formula (Φ2-34), trivalent groups represented by the following formula (Φ3-1) to formula (Φ3-3), and tetravalent groups represented by the following formula (Φ4-1) to formula (Φ4-2). At least one hydrogen of Φ can be substituted by an alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 3 to 14 carbon atoms, an aryl group having 6 to 18 carbon atoms, or a heteroaryl group having 2 to 18 carbon atoms.

[0744]

[0745]

[0746] In the formula, Z is >CR2, >N-Ar, >N-L, -O-, or -S-, >CR 2 The Rs in are each independently an alkyl group having 1 to 4 carbon atoms, a cycloalkyl group having 5 to 10 carbon atoms, an aryl group having 6 to 12 carbon atoms, or a heteroaryl group having 2 to 12 carbon atoms. The Rs can be bonded to each other to form a ring. Ar in >N-Ar is an aryl group having 6 to 12 carbon atoms or a heteroaryl group having 2 to 12 carbon atoms. L in >N-L is L in formula (ETM-16), formula (ETM-16-1), or formula (ETM-16-2). The * in the formula indicates the bonding position.

[0747] Preferably, L is a divalent group of a ring selected from the group consisting of benzene, naphthalene, pyridine, pyrazine, pyrimidine, pyridazine, triazine, quinoline, isoquinoline, naphthyridine, phthalazine, quinoxaline, quinazoline, cinnoline, and pteridine. At least one hydrogen of L can be substituted by an alkyl group having 1 to 4 carbon atoms, a cycloalkyl group having 5 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, or a heteroaryl group having 2 to 10 carbon atoms.

[0748] Preferably, Ar in >N-Ar as Y or Z is selected from the group consisting of phenyl, naphthyl, pyridyl, pyrazinyl, pyrimidinyl, pyridazinyl, triazinyl, quinolinyl, isoquinolinyl, naphthyridinyl, phthalazinyl, quinoxalinyl, quinazolinyl, cinnolinyl, and pteridinyl, and at least one hydrogen of Ar in >N-Ar as Y may be substituted with an alkyl group having 1 to 4 carbon atoms, a cycloalkyl group having 5 to 10 carbon atoms, or an aryl group having 6 to 10 carbon atoms.

[0749] Preferably, R 1 ~R 4 are each independently hydrogen, an alkyl group having 1 to 4 carbon atoms, or a cycloalkyl group having 5 to 10 carbon atoms, where R 1 is the same as R 2 , R 3 is the same as R 4 , and R 1 ~R 4 do not all become hydrogen simultaneously, and m is 1 or 2. When m is 2, the group formed by the oxazoline ring and L is the same.

[0750] As specific examples of the oxazoline derivative, for example, the following compounds can be cited. In addition, "Me" in the structural formula represents a methyl group.

[0751]

[0752] More preferably, Φ is selected from the group consisting of divalent groups represented by the following formula (Φ2-1), formula (Φ2-31), formula (Φ2-32), formula (Φ2-33), and formula (Φ2-34), and at least one hydrogen of Φ may be substituted with an aryl group having 6 to 18 carbon atoms. In addition, * in the following formula represents the bonding position.

[0753]

[0754] L is a divalent group of a ring selected from the group consisting of benzene, pyridine, pyrazine, pyrimidine, pyridazine, and triazine, and at least one hydrogen of L may be substituted with an alkyl group having 1 to 4 carbon atoms, a cycloalkyl group having 5 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, or a heteroaryl group having 2 to 14 carbon atoms.

[0755] Ar in >N-Ar as Y is selected from the group consisting of phenyl, pyridyl, pyrazinyl, pyrimidinyl, pyridazinyl, and triazinyl, and at least one hydrogen of the Ar may be substituted with an alkyl group having 1 to 4 carbon atoms, a cycloalkyl group having 5 to 10 carbon atoms, or an aryl group having 6 to 10 carbon atoms.

[0756] R 1 ~R 4 are each independently hydrogen, an alkyl group having 1 to 4 carbon atoms, or a cycloalkyl group having 5 to 10 carbon atoms, where R 1 is the same as R 2Same, R 3 With R 4 Same, and R 1 ~R 4 will not all become hydrogen simultaneously, and,

[0757] m is 2, and the group formed by the oxazoline ring and L is the same.

[0758] As other specific examples of the oxazoline derivatives, for example, the following compounds can be cited. In addition, "Me" in the structural formula represents a methyl group.

[0759]

[0760] Regarding the details of the alkyl, cycloalkyl, aryl or heteroaryl in the respective formulas defining the oxazoline derivatives, the description in formula (1) can be cited.

[0761] The oxazoline derivatives can be prepared using known raw materials and known synthesis methods.

[0762] <Reducing substance>

[0763] A substance that can reduce the material forming the electron transport layer or the electron injection layer may also be included in the electron transport layer or the electron injection layer. As long as the reducing substance is a substance having a certain reducing property, various substances can be used. For example, at least one selected from the group consisting of alkali metals, alkaline earth metals, rare earth metals, oxides of alkali metals, halides of alkali metals, oxides of alkaline earth metals, halides of alkaline earth metals, oxides of rare earth metals, halides of rare earth metals, organic complexes of alkali metals, organic complexes of alkaline earth metals, and organic complexes of rare earth metals can be preferably used.

[0764] As preferred reducing substances, alkali metals such as Na (work function 2.36 eV), K (work function 2.28 eV), Rb (work function 2.16 eV), or Cs (work function 1.95 eV), or alkaline earth metals such as Ca (work function 2.9 eV), Sr (work function 2.0 eV to 2.5 eV), or Ba (work function 2.52 eV) can be cited. Substances with a work function of 2.9 eV or less are particularly preferred. Among these, more preferred reducing substances are alkali metals such as K, Rb, or Cs, and further preferred are Rb or Cs, and most preferred is Cs. The reduction ability of these alkali metals is particularly high. By adding a relatively small amount of the alkali metal to the material forming the electron transport layer or the electron injection layer, an increase in the emission luminance or a longer lifespan of the organic EL element can be achieved. In addition, as a reducing substance with a work function of 2.9 eV or less, a combination of two or more of these alkali metals is also preferred, and a combination containing Cs is particularly preferred, such as a combination of Cs and Na, Cs and K, Cs and Rb, or Cs and Na and K. By containing Cs, the reduction ability can be effectively exerted, and by adding it to the material forming the electron transport layer or the electron injection layer, an increase in the emission luminance or a longer lifespan of the organic EL element can be achieved.

[0765] The materials for the electron injection layer and the electron transport layer can also be used as the following polymer compounds or their polymer crosslinks, or the following pendant polymer compounds or their pendant polymer crosslinks in the materials for the electron layer. The polymer compound is obtained by polymerizing a reactive compound in which a reactive substituent is substituted in the materials for the electron injection layer and the electron transport layer as a monomer. The pendant polymer compound is obtained by reacting a main-chain polymer with the reactive compound. As the reactive substituent in this case, the description in the polycyclic aromatic compound containing the partial structure represented by the formula (1) can be cited.

[0766] Details of the uses of such polymer compounds and polymer crosslinks will be described later.

[0767] 3-1-7. Cathode in organic electroluminescent element

[0768] The cathode 108 functions to inject electrons into the light-emitting layer 105 via the electron injection layer 107 and the electron transport layer 106.

[0769] As the material for forming the cathode 108, if it is a substance that can inject electrons efficiently into the organic layer, there is no particular limitation, and the same material as that for forming the anode 102 can be used. Among them, metals such as tin, indium, calcium, aluminum, silver, copper, nickel, chromium, gold, platinum, iron, zinc, lithium, sodium, potassium, cesium, and magnesium, or alloys thereof (such as magnesium-silver alloy, magnesium-indium alloy, aluminum-lithium alloys such as lithium fluoride / aluminum, etc.) are preferred. In order to improve the electron injection efficiency and thus improve the device characteristics, lithium, sodium, potassium, cesium, calcium, magnesium, or alloys containing these low work function metals are effective. However, generally, most of these low work function metals are unstable in the atmosphere. To improve this point, for example, a method of doping a trace amount of lithium, cesium, or magnesium into the organic layer and using an electrode with high stability is known. As other dopants, inorganic salts such as lithium fluoride, cesium fluoride, lithium oxide, and cesium oxide can also be used. However, it is not limited to these.

[0770] Furthermore, the following can be cited as preferred examples: metals such as platinum, gold, silver, copper, iron, tin, aluminum, and indium, or alloys using these metals, as well as inorganic substances such as silicon dioxide, titanium dioxide, and silicon nitride, polyvinyl alcohol, vinyl chloride, hydrocarbon-based polymer compounds, etc. are laminated to protect the electrode. As long as the manufacturing method of these electrodes is a method that can achieve conduction such as resistance heating, electron beam evaporation, sputtering, ion plating, and coating, there is no particular limitation.

[0771] 3-1-8. Binder that can be used in each layer

[0772] The materials used in the above hole injection layer, hole transport layer, light-emitting layer, electron transport layer, and electron injection layer can form each layer individually, or can be dispersed in a solvent-soluble resin such as polyvinyl chloride, polycarbonate, polystyrene, poly(N-vinylcarbazole), polymethyl methacrylate, polybutyl methacrylate, polyester, polysulfone, polyphenylene ether, polybutadiene, hydrocarbon resin, ketone resin, phenoxy resin, polyamide, ethyl cellulose, vinyl acetate resin, acrylonitrile-butadiene-styrene (ABS) resin, polyurethane resin, etc., which is used as a polymer binder, or a curable resin such as phenol resin, xylene resin, petroleum resin, urea resin, melamine resin, unsaturated polyester resin, alkyd resin, epoxy resin, silicone resin, etc.

[0773] 3-1-9. Manufacturing method of organic electroluminescent element

[0774] Each layer constituting the organic EL element can be formed by forming a thin film of the material to constitute each layer using methods such as evaporation coating method, resistance heating evaporation coating, electron beam evaporation coating, sputtering, molecular layer deposition method, printing method, spin coating method, casting method, coating method, etc. The film thickness of each layer formed in the above manner is not particularly limited and can be appropriately set according to the properties of the material, but is usually in the range of 2 nm to 5000 nm. The film thickness can generally be measured using a quartz oscillator type film thickness measuring device, etc. In the case of thinning by the evaporation coating method, the evaporation coating conditions vary depending on the type of material, the target crystal structure and association structure of the film to be formed, etc. Generally, the evaporation coating conditions are preferably set appropriately within the range of a boat heating temperature of +50°C to +400°C, a vacuum degree of 10 -6 ~10 -3 Pa, an evaporation coating speed of 0.01 nm / second to 50 nm / second, a substrate temperature of -150°C to +300°C, and a film thickness of 2 nm to 5 μm.

[0775] When a DC voltage is applied to the organic EL element obtained in the above manner, it is only necessary to apply the anode as the + polarity and the cathode as the - polarity. If a voltage of about 2 V to 40 V is applied, light emission can be observed from the transparent or semi-transparent electrode side (anode or cathode and both). In addition, the organic EL element also emits light when a pulsed current or an alternating current is applied. In addition, the waveform of the applied alternating current can be arbitrary.

[0776] Next, as an example of a method for manufacturing an organic EL element, a method for manufacturing an organic EL element including an anode / hole injection layer / hole transport layer / light-emitting layer containing a host material and a dopant material / electron transport layer / electron injection layer / cathode will be described.

[0777] <Evaporation Coating Method>

[0778] On a suitable substrate, an anode is fabricated by forming a thin film of an anode material using the evaporation coating method or the like. Then, thin films of a hole injection layer and a hole transport layer are formed on the anode. On the thin films, co-evaporation of a host material and a dopant material is performed to form a thin film as the light-emitting layer. An electron transport layer and an electron injection layer are formed on the light-emitting layer. Furthermore, a thin film containing a cathode material is formed using the evaporation coating method or the like as the cathode, thereby obtaining the target organic EL element. In addition, in the manufacture of the organic EL element, the manufacturing order can also be reversed and fabricated in the order of cathode, electron injection layer, electron transport layer, light-emitting layer, hole transport layer, hole injection layer, anode.

[0779] <Wet Film Formation Method>

[0780] A low-molecular compound for forming each organic layer of an organic EL element is prepared as a liquid organic layer-forming composition, and a wet film-forming method is carried out using the same. In the absence of a suitable organic solvent for dissolving the low-molecular compound, an organic layer-forming composition can also be prepared from a polymer compound or the like, which is polymerized together with another monomer or a main-chain polymer having a dissolution function as a reactive compound obtained by substituting a reactive substituent in the low-molecular compound.

[0781] Generally, the wet film-forming method forms a coating film through the following steps: a coating step of coating an organic layer-forming composition on a substrate and a drying step of removing the solvent from the coated organic layer-forming composition. When the polymer compound has a crosslinkable substituent (also referred to as a crosslinkable polymer compound), further crosslinking is carried out through the drying step to form a polymer crosslink. Depending on the coating step, the method using a spin coater is called the spin coating method, the method using a slot coater is called the slot coating method, the method using a plate is called the gravure, lithography, reverse lithography, flexography method, the method using an inkjet printer is called the inkjet method, and the method of spraying in a mist form is called the spray method.

[0782] In the drying step, there are methods such as air drying, heating, and vacuum drying. The drying step can be carried out only once, or can be carried out multiple times using different methods or conditions. In addition, for example, different methods can be used in combination, such as calcination under reduced pressure.

[0783] The wet film-forming method refers to a film-forming method using a solution, such as a part of the printing method (inkjet method), spin coating method, casting method, coating method, etc. Different from the vacuum evaporation method, the wet film-forming method does not require the use of an expensive vacuum evaporation device and can form a film under atmospheric pressure. In addition, the wet film-forming method can be enlarged in area or continuously produced, thereby reducing the preparation cost.

[0784] On the other hand, compared with the vacuum evaporation method, it is sometimes difficult to laminate the wet film-forming method. When manufacturing a laminated film using the wet film-forming method, it is necessary to prevent the dissolution of the lower layer caused by the composition of the upper layer, and use a composition with controlled solubility, crosslinking of the lower layer, and orthogonal solvents (solvents that are insoluble in each other). However, there are cases where it is difficult to apply the wet film-forming method to the coating of all films even using these techniques.

[0785] Therefore, generally, the following method is adopted: only several layers are formed using the wet film-forming method, and the remaining layers are formed using the vacuum evaporation method to manufacture an organic EL element.

[0786] For example, the following shows a part of the procedure for manufacturing an organic EL element using the wet film-forming method.

[0787] (Process 1) Film formation on the anode by vacuum evaporation

[0788] (Process 2) Film formation of the hole injection layer forming composition containing the hole injection layer material by wet film formation method

[0789] (Process 3) Film formation of the hole transport layer forming composition containing the hole transport layer material by wet film formation method

[0790] (Process 4) Film formation of the light-emitting layer forming composition containing the host material and the dopant material by wet film formation method

[0791] (Process 5) Film formation on the electron transport layer by vacuum evaporation

[0792] (Process 6) Film formation on the electron injection layer by vacuum evaporation

[0793] (Process 7) Film formation on the cathode by vacuum evaporation

[0794] By going through the above processes, an organic EL element including an anode / hole injection layer / hole transport layer / light-emitting layer containing a host material and a dopant material / electron transport layer / electron injection layer / cathode can be obtained.

[0795] Of course, for the electron transport layer and the electron injection layer, layer forming compositions containing the electron transport layer material and the electron injection layer material can also be used respectively, and film formation can be carried out by the wet film formation method. At this time, it is preferable to use a method of preventing the dissolution of the underlying light-emitting layer, or a method of film formation from the cathode side contrary to the above process.

[0796] <Other film formation methods>

[0797] Laser heating lithography (Laser Induced Thermal Imaging, LITI) can be used in the film formation of the organic layer forming composition. LITI refers to a method of heating and evaporating a compound attached to a substrate using a laser, and the organic layer forming composition can be used in the material coated on the substrate.

[0798] <Optional processes>

[0799] Before and after each process of film formation, appropriate treatment processes, cleaning processes and drying processes can also be appropriately added. As treatment processes, for example, exposure treatment, plasma surface treatment, ultrasonic treatment, ozone treatment, cleaning treatment using an appropriate solvent, heating treatment, etc. can be cited. Furthermore, a series of processes for making dams can also be cited.

[0800] Lithography techniques can be used in the fabrication of the bank portion. As bank portion materials that can utilize lithography, positive resist materials and negative resist materials can be used. Additionally, printing methods capable of forming patterns such as inkjet printing, intaglio lithography, reverse lithography, and screen printing can also be used. In this case, permanent resist materials can also be used.

[0801] Examples of materials for the bank portion include polysaccharides and their derivatives, homopolymers and copolymers of vinyl monomers having hydroxyl groups, biopolymer compounds, polyacryloyl compounds, polyesters, polystyrenes, polyimides, polyamide-imides, polyether-imides, polysulfides, polysulfones, polyphenylene, polyphenyl ethers, polyurethanes, (meth)acrylic epoxy esters, (meth)acrylic melamine esters, polyolefins, cyclic polyolefins, acrylonitrile-butadiene-styrene copolymer polymers (ABS), silicone resins, polyvinyl chlorides, chlorinated polyethylenes, chlorinated polypropylenes, polyacetates, polynorbornenes, synthetic rubbers, polyvinylidene fluorides, fluorinated polymers such as polytetrafluoroethylene and polyhexafluoropropylene, copolymer polymers of fluoroolefins and hydrocarbon olefins, and fluorocarbon polymers, but are not limited thereto.

[0802] <Organic layer-forming composition used in wet film-forming method>

[0803] The organic layer-forming composition is obtained by dissolving a low molecular weight compound that can form each organic layer of the organic EL element, or a high molecular weight compound obtained by polymerizing the low molecular weight compound, in an organic solvent. For example, the composition for forming a light-emitting layer contains at least one dopant material, i.e., a polycyclic aromatic compound (or its high molecular weight compound), as the first component, at least one host material as the second component, and at least one organic solvent as the third component. The first component functions as a dopant component of the light-emitting layer obtained from the composition, and the second component functions as a host component of the light-emitting layer. The third component functions as a solvent for dissolving the first component and the second component in the composition, and provides a smooth and uniform surface shape by virtue of its controlled evaporation rate during coating.

[0804] <Organic solvent>

[0805] The organic layer-forming composition contains at least one organic solvent. By controlling the evaporation rate of the organic solvent during film formation, the film-forming property, the presence or absence of defects in the coating film, the surface roughness, and the smoothness can be controlled and improved. Additionally, when using the inkjet method for film formation, the stability of the meniscus at the nozzle holes of the inkjet head can be controlled, and the ejection property can be controlled / improved. Furthermore, by controlling the drying rate of the film and the orientation of the derivative molecules, the electrical characteristics, light-emitting characteristics, efficiency, and lifespan of the organic EL element having the organic layer obtained from the organic layer-forming composition can be improved.

[0806] (1) Physical properties of organic solvents

[0807] The boiling point of at least one organic solvent is 130°C to 300°C, more preferably 140°C to 270°C, and still more preferably 150°C to 250°C. From the viewpoint of the ejection property of inkjet, it is preferably the case where the boiling point is higher than 130°C. In addition, from the viewpoints of film defects, surface roughness, residual solvent, and smoothness, it is preferably the case where the boiling point is lower than 300°C. From the viewpoints of good inkjet ejection property, film-forming property, smoothness, and low residual solvent, the organic solvent is more preferably composed of two or more organic solvents. On the other hand, depending on the situation, considering portability, etc., it may also be a composition made into a solid state by removing the solvent from the organic layer-forming composition.

[0808] Furthermore, the organic solvent contains a good solvent (GS) and a poor solvent (PS) for at least one of the solutes, and it is particularly preferable that the boiling point (BP GS ) of the good solvent (GS) is lower than the boiling point (BP PS ) of the poor solvent (PS).

[0809] By adding a high-boiling poor solvent, the low-boiling good solvent volatilizes first during film formation, and the concentration of the contained substances and the concentration of the poor solvent in the composition increase and promote rapid film formation. Thereby, a film with few defects, small surface roughness, and high smoothness can be obtained.

[0810] The difference in solubility (S GS -S PS ) is preferably 1% or more, more preferably 3% or more, and still more preferably 5% or more. The difference in boiling point (BP PS -BP GS ) is preferably 10°C or more, more preferably 30°C or more, and still more preferably 50°C or more.

[0811] The organic solvent is removed from the coating film through drying processes such as vacuum, reduced pressure, and heating after film formation. In the case of heating, from the viewpoint of improving the coating film-forming property, it is preferably carried out at a temperature of the glass transition temperature (Tg) of at least one of the solutes + 30°C or lower. In addition, from the viewpoint of reducing the residual solvent, it is preferably heated at a temperature of the glass transition temperature (Tg) of at least one of the solutes - 30°C or higher. Even if the heating temperature is lower than the boiling point of the organic solvent, due to the thin film, the organic solvent is sufficiently removed. In addition, drying can be carried out multiple times at different temperatures, or multiple drying methods can be used in combination.

[0812] (2) Specific examples of organic solvents

[0813] As the organic solvent for the composition for forming an organic layer, alkylbenzene solvents, phenyl ether solvents, alkyl ether solvents, cyclic ketone solvents, aliphatic ketone solvents, monocyclic ketone solvents, solvents having a diester skeleton, fluorine-containing solvents, etc. can be cited. As specific examples, the following can be cited: pentanol, hexanol, heptanol, octanol, nonanol, decanol, undecanol, dodecanol, tetradecanol, hexan-2-ol, heptan-2-ol, octan-2-ol, decan-2-ol, dodecan-2-ol, cyclohexanol, α-terpineol, β-terpineol, γ-terpineol, δ-terpineol, terpineol (mixture), ethylene glycol monomethyl ether acetate, propylene glycol monomethyl ether acetate, diethylene glycol dimethyl ether, dipropylene glycol dimethyl ether, diethylene glycol ethyl methyl ether, diethylene glycol isopropyl methyl ether, dipropylene glycol monomethyl ether, diethylene glycol diethyl ether, diethylene glycol monomethyl ether, diethylene glycol butyl methyl ether, tripropylene glycol dimethyl ether, triethylene glycol dimethyl ether, diethylene glycol monobutyl ether, ethylene glycol monophenyl ether, triethylene glycol monomethyl ether, diethylene glycol dibutyl ether, triethylene glycol butyl methyl ether, polyethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, p-xylene, m-xylene, o-xylene, 2,6-dimethylpyridine, 2-fluoro-m-xylene, 3-fluoro-o-xylene, 2-chlorobenzotrifluoride, cumene, toluene, 2-chloro-6-fluorotoluene, 2-fluorobenzyl ether, benzyl ether, 2,3-dimethylpyrazine, bromobenzene, 4-fluorobenzyl ether, 3-fluorobenzyl ether, 3-trifluoromethylbenzyl ether, mesitylene, 1,2,4-trimethylbenzene, tert-butylbenzene, 2-methylbenzyl ether, phenetole, benzodioxole, 4-methylbenzyl ether, sec-butylbenzene, 3-methylbenzyl ether, 4-fluoro-3-methylbenzyl ether, cymene, 1,2,3-trimethylbenzene, 1,2-dichlorobenzene, 2-fluorobenzonitrile, 4-fluoroveratrole, 2,6-dimethylbenzyl ether, n-butylbenzene, 3-fluorobenzonitrile, decalin (decahydronaphthalene), neopentylbenzene, 2,5-dimethylbenzyl ether, 2,4-dimethylbenzyl ether, benzonitrile, 3,5-dimethylbenzyl ether, diphenyl ether, 1-fluoro-3,5-dimethoxybenzene, methyl benzoate, isoamylbenzene, 3,4-dimethylbenzyl ether, o-tolunitrile, n-pentylbenzene, veratrole, 1,2,3,4-tetrahydronaphthalene, ethyl benzoate, n-hexylbenzene, propyl benzoate, cyclohexylbenzene, 1-methylnaphthalene, butyl benzoate, 2-methylbiphenyl, 3-phenoxytoluene, 2,2'-bitolyl, dodecylbenzene, dipentylbenzene, tetramethylbenzene, trimethoxybenzene, trimethoxytoluene, 2,3-dihydrobenzofuran, 1-methyl-4-(propoxymethyl)benzene, 1-methyl-4-(butoxymethyl)benzene, 1-methyl-4-(pentyloxymethyl)benzene, 1-methyl-4-(hexyloxymethyl)benzene, 1-methyl-4-(heptyloxymethyl)benzene, benzyl butyl ether, benzyl pentyl ether, benzyl hexyl ether, benzyl heptyl ether, benzyl octyl ether, etc., but not limited thereto. In addition, the solvent can be used alone or in combination.,

[0814] <Any component>

[0815] The composition for forming an organic layer may also contain any component within a range not impairing its properties. Examples of the optional component include adhesives and surfactants.,

[0816] (1) Adhesive

[0817] The composition for forming an organic layer may also contain an adhesive. The adhesive forms a film during film formation and bonds the obtained film to the substrate. In addition, in the composition for forming an organic layer, it functions to dissolve, disperse, and bond other components.,

[0818] Examples of the adhesive used in the composition for forming an organic layer include: acrylic resin, polyethylene terephthalate, ethylene-vinyl acetate copolymer, ethylene-vinyl alcohol copolymer, acrylonitrile-ethylene-styrene copolymer (Acrylonitrile-Ethylene-Styrene, AES) resin, ionomer, chlorinated polyether, diallyl phthalate resin, unsaturated polyester resin, polyethylene, polypropylene, polyvinyl chloride, polyvinylidene chloride, polystyrene, polyvinyl acetate, Teflon, acrylonitrile-butadiene-styrene copolymer (ABS) resin, acrylonitrile-styrene copolymer (Acrylonitrile-Styrene, AS) resin, phenolic resin, epoxy resin, melamine resin, urea resin, alkyd resin, polyurethane, and copolymers of the above resins and polymers, but not limited thereto.,

[0819] The adhesive used in the composition for forming an organic layer may be only one kind or a plurality of kinds may be used in combination.,

[0820] (2) Surfactant

[0821] For example, in order to control the film surface uniformity, the solvent affinity, and the liquid repellency of the composition for forming an organic layer, the composition for forming an organic layer may also contain a surfactant. Surfactants are classified into ionic and non-ionic types according to the structure of the hydrophilic group, and further classified into alkyl-based, silicone-based, and fluorine-based types according to the structure of the hydrophobic group. In addition, according to the molecular structure, they are classified into single-molecule types with a relatively small molecular weight and a simple structure, and polymer types with a large molecular weight and side chains or branches. In addition, according to the composition, they are classified into single types, mixed types containing two or more surfactants and substrates. As the surfactant that can be used in the composition for forming an organic layer, all types of surfactants can be used.

[0822] As surfactants, for example, the following can be cited: Polyflow No.45, Polyflow KL-245, Polyflow No.75, Polyflow No.90, Polyflow No.95 (trade names, manufactured by Kyoeisha Chemical Co., Ltd.), Disperbyk 161, Disperbyk 162, Disperbyk 163, Disperbyk 164, Disperbyk 166, Disperbyk 170, Disperbyk 180, Disperbyk 181, Disperbyk 182, BYK 300, BYK 306, BYK 310, BYK 320, BYK 330, BYK 342, BYK 344, BYK 346 (trade names, manufactured by BYK-Chemie Japan Co., Ltd.), KP-341, KP-358, KP-368, KF-96-50CS, KF-50-100CS (trade names, manufactured by Shin-Etsu Chemical Co., Ltd.), Surflon SC-101, Surflon KH-40 (trade names, manufactured by Seimi Chemical Co., Ltd.), Ftergent 222F, Ftergent 251, FTX-218 (trade names, manufactured by NEOS Co., Ltd.), EFTOP EF-351, EFTOP EF-352, EFTOP EF-601, EFTOP EF-801, EFTOP EF-802 (trade names, manufactured by Mitsubishi Material Co., Ltd.), Megafac F-470, Megafac F-471, Megafac F-475, Megafac R-08, Megafac F-477, Megafac F-479, Megafac F-553, Megafac F-554 (trade names,Manufactured by Dainippon Ink and Chemicals, Incorporated (DIC), fluoroalkylbenzenesulfonates, fluoroalkylcarboxylates, fluoroalkylpolyoxyethylene ethers, fluoroalkylammonium iodides, fluoroalkylbetaines, fluoroalkylsulfonates, diglycerol tetra(fluoroalkylpolyoxyethylene ether), fluoroalkyltrimethylammonium salts, fluoroalkylaminosulfonates, polyoxyethylene nonylphenyl ethers, polyoxyethylene octylphenyl ethers, polyoxyethylene alkyl ethers, polyoxyethylene laurate, polyoxyethylene oleate, polyoxyethylene stearate, polyoxyethylene laurylamine, sorbitan laurate, sorbitan palmitate, sorbitan stearate, sorbitan oleate, sorbitan fatty acid esters, polyoxyethylene sorbitan laurate, polyoxyethylene sorbitan palmitate, polyoxyethylene sorbitan stearate, polyoxyethylene sorbitan oleate, polyoxyethylene naphthyl ether, alkylbenzenesulfonates and alkyl diphenyl ether disulfonates.,

[0823] In addition, one surfactant may be used, or two or more surfactants may be used in combination.

[0824] <Composition and Physical Properties of Organic Layer Forming Composition>

[0825] In consideration of the good solubility, storage stability and film-forming properties of each component in the organic layer forming composition, the high-quality film quality of the coating film obtained from the organic layer forming composition, the good ejection properties when using the inkjet method, and the good electrical characteristics, light-emitting characteristics, efficiency and lifespan of the organic EL element having an organic layer made using the composition, the content of each component in the organic layer forming composition is determined. For example, in the case of a composition for forming a light-emitting layer, it is preferably: the first component is 0.0001% by mass to 2.0% by mass relative to the total mass of the composition for forming a light-emitting layer, the second component is 0.0999% by mass to 8.0% by mass relative to the total mass of the composition for forming a light-emitting layer, and the third component is 90.0% by mass to 99.9% by mass relative to the total mass of the composition for forming a light-emitting layer.

[0826] More preferably: the first component is 0.005% by mass to 1.0% by mass relative to the total mass of the composition for forming a light-emitting layer, the second component is 0.095% by mass to 4.0% by mass relative to the total mass of the composition for forming a light-emitting layer, and the third component is 95.0% by mass to 99.9% by mass relative to the total mass of the composition for forming a light-emitting layer. Even more preferably: the first component is 0.05% by mass to 0.5% by mass relative to the total mass of the composition for forming a light-emitting layer, the second component is 0.25% by mass to 2.5% by mass relative to the total mass of the composition for forming a light-emitting layer, and the third component is 97.0% by mass to 99.7% by mass relative to the total mass of the composition for forming a light-emitting layer.

[0827] The composition for forming an organic layer can be prepared by appropriately selecting the above components and subjecting them to stirring, mixing, heating, cooling, dissolving, dispersing, etc. using known methods. Further, after preparation, filtration, degassing (also referred to as air removal (degas)), ion exchange treatment, and inert gas replacement / encapsulation treatment, etc. can be appropriately selected.

[0828] Regarding the viscosity of the composition for forming an organic layer, good film-forming properties and good ejection properties when using the inkjet method can be obtained in the case of high viscosity. On the other hand, in the case of low viscosity, it is easy to form a thin film. According to the above situation, the viscosity of the composition for forming an organic layer is preferably 0.3 mPa·s to 3 mPa·s at 25°C, more preferably 1 mPa·s to 3 mPa·s. In the present invention, the viscosity is a value measured using a cone-plate type rotational viscometer.

[0829] Regarding the surface tension of the composition for forming an organic layer, good film-forming properties and a defect-free coating film can be obtained in the case of low surface tension. On the other hand, good inkjet ejection properties can be obtained in the case of high surface tension. According to the above situation, the surface tension of the composition for forming an organic layer is preferably 20 mN / m to 40 mN / m at 25°C, more preferably 20 mN / m to 30 mN / m. In the present invention, the surface tension is a value measured using the pendant drop method.

[0830] <Crosslinkable polymer compound: a compound represented by formula (XLP-1)>

[0831] Next, the case where the polymer compound has a crosslinkable substituent will be described. Such a crosslinkable polymer compound is, for example, a compound represented by the following formula (XLP-1).

[0832]

[0833] In formula (XLP-1),

[0834] MUx, ECx, and k have the same definitions as MU, EC, and k in formula (H3), where the compound represented by formula (XLP-1) has at least one crosslinkable substituent (XLS), and preferably the content of the monovalent or divalent aromatic group having a crosslinkable substituent in the molecule is 0.1 mass% to 80 mass%.

[0835] The content of the monovalent or divalent aromatic group having a crosslinkable substituent in the molecule is preferably 0.5 mass% to 50 mass%, more preferably 1 mass% to 20 mass%.

[0836] As the crosslinkable substituent (XLS), if it is a group capable of further crosslinking the polymer compound, it is not particularly limited, and a substituent having the following structure is preferred. * in each structural formula represents the bonding position.

[0837]

[0838] L is independently a single bond, -O-, -S-, >C=O, -O-C(=O)-, an alkylene group having 1 to 12 carbon atoms, an oxyalkylene group having 1 to 12 carbon atoms, and a polyoxyalkylene group having 1 to 12 carbon atoms. Among the substituents, a group represented by formula (XLS-1), formula (XLS-2), formula (XLS-3), formula (XLS-9), formula (XLS-10), or formula (XLS-17) is preferred, and a group represented by formula (XLS-1), formula (XLS-3), or formula (XLS-17) is more preferred.

[0839] Examples of the divalent aromatic compound having a crosslinkable substituent include compounds having the following partial structures.

[0840]

[0841]

[0842] <Preparation Method of Polymer Compound and Crosslinkable Polymer Compound>

[0843] Regarding the preparation methods of the polymer compound and the crosslinkable polymer compound, the compounds represented by the formula (H3) and the compound represented by (XLP-1) are taken as examples for illustration. These compounds can be synthesized by appropriately combining known preparation methods.

[0844] Examples of the solvent used in the reaction include aromatic solvents, saturated / unsaturated hydrocarbon solvents, alcohol solvents, ether solvents, etc., and examples include: dimethoxyethane, 2-(2-methoxyethoxy)ethane, 2-(2-ethoxyethoxy)ethane, etc.

[0845] In addition, the reaction can also be carried out in a two-phase system. When the reaction is carried out in a two-phase system, a phase transfer catalyst such as a quaternary ammonium salt can also be added as needed.

[0846] When preparing the compound of formula (H3) and the compound of (XLP-1), it can be prepared in one stage or via multiple stages. Additionally, it can be carried out by the overall polymerization method of putting all the raw materials into the reaction vessel and then starting the reaction, or by the dropping polymerization method of dropping the raw materials into the reaction vessel, or by the precipitation polymerization method in which the product precipitates as the reaction proceeds. These methods can be appropriately combined for synthesis. For example, when synthesizing the compound represented by formula (H3) in one stage, the reaction is carried out in a state where the monomer having a polymerizable group bonded to the monomer unit (MU) and the monomer having a polymerizable group bonded to the end-capping unit (EC) are added to the reaction vessel, thereby obtaining the target product. Additionally, when synthesizing the compound represented by formula (H3) in multiple stages, the monomer having a polymerizable group bonded to the monomer unit (MU) is polymerized to the target molecular weight, and then the monomer having a polymerizable group bonded to the end-capping unit (EC) is added and reacted, thereby obtaining the target product. If monomers having polymerizable groups bonded to different types of monomer units (MU) are added in multiple stages for reaction, a polymer having a concentration gradient with respect to the structure of the monomer unit can be produced. Additionally, after preparing the precursor polymer, the target polymer can be obtained through subsequent reactions.

[0847] Additionally, if the polymerizable group of the monomer is selected, the primary structure of the polymer can be controlled. For example, as shown in Synthesis Processes 1 to 3, a polymer having a random primary structure (Synthesis Process 1), a polymer having a regular primary structure (Synthesis Processes 2 and 3), etc. can be synthesized, and they can be appropriately combined and used according to the target product. Furthermore, if a monomer having three or more polymerizable groups is used, a hyperbranched polymer or a dendrimer can be synthesized.

[0848]

[0849] As the monomers that can be used in the present invention, they can be synthesized according to the methods described in Japanese Patent Application Laid-Open No. 2010-189630, International Publication No. 2012 / 086671, International Publication No. 2013 / 191088, International Publication No. 2002 / 045184, International Publication No. 2011 / 049241, International Publication No. 2013 / 146806, International Publication No. 2005 / 049546, International Publication No. 2015 / 145871, Japanese Patent Application Laid-Open No. 2010-215886, Japanese Patent Application Laid-Open No. 2008-106241, International Publication No. 2016 / 031639, and Japanese Patent Application Laid-Open No. 2011-174062.

[0850] In addition, regarding the specific polymer synthesis sequence, it can be synthesized according to the methods described in Japanese Patent Application Laid-Open No. 2012-036388, International Publication No. 2015 / 008851, Japanese Patent Application Laid-Open No. 2012-36381, Japanese Patent Application Laid-Open No. 2012-144722, International Publication No. 2015 / 194448, International Publication No. 2013 / 146806, International Publication No. 2015 / 145871, International Publication No. 2016 / 031639, International Publication No. 2016 / 125560, and International Publication No. 2011 / 049241.

[0851] 3-1-10. Application examples of organic electroluminescent element

[0852] In addition, the present invention can also be applied to a display device including an organic EL element, a lighting device including an organic EL element, and the like.

[0853] A display device or a lighting device including an organic EL element can be manufactured by known methods such as connecting the organic EL element of the present embodiment to a known driving device, and known driving methods such as direct current driving, pulse driving, and alternating current driving can be suitably used for driving.

[0854] Examples of the display device include panel displays such as color flat panel displays, flexible displays such as flexible color organic electroluminescent (EL) displays (for example, refer to Japanese Patent Application Laid-Open No. 10-335066, Japanese Patent Application Laid-Open No. 2003-321546, Japanese Patent Application Laid-Open No. 2004-281086, etc.). In addition, examples of the display mode of the display include a matrix mode and / or a segment mode. Furthermore, matrix display and segment display can coexist in the same panel.

[0855] In a matrix, pixels for display are two-dimensionally arranged in a lattice shape or a mosaic shape, etc., so that characters or images are displayed by a collection of pixels. The shape or size of the pixels is determined according to the use. For example, in the image and text display of a personal computer, a monitor, or a television, pixels that are quadrilaterals with a side length of 300 μm or less are usually used. In addition, in the case of a large display such as a display screen, pixels with a side length of the mm level are used. In the case of monochromatic display, pixels of the same color only need to be arranged, and in the case of color display, red, green, and blue pixels are arranged side by side for display. In the above cases, a triangular type and a stripe type are typical. Moreover, as the driving method of the matrix, either a line-sequential driving method or an active matrix can be used. The line-sequential driving has the advantage of simple structure, but in consideration of the operating characteristics, the active matrix is sometimes more excellent, so the driving method also needs to be selected according to the use.

[0856] In the segmented mode (type), a pattern is formed in such a way as to display predetermined information, and a determined area is made to emit light. Examples include the display of time or temperature in a digital clock or thermometer, the display of the operating state of an audio device or an induction cooker, and the display on the dashboard of a car, etc.

[0857] As the lighting device, examples include lighting devices such as indoor lighting, backlights of liquid crystal display devices, etc. (for example, refer to Japanese Patent Laid-Open No. 2003-257621, Japanese Patent Laid-Open No. 2003-277741, Japanese Patent Laid-Open No. 2004-119211, etc.). The backlight is mainly used to improve the visibility of a display device that does not emit light by itself, and is used for liquid crystal display devices, clocks, audio devices, car dashboards, display boards, signs, etc. In particular, as the backlight for personal computer applications where thinning is a problem in liquid crystal display devices, considering that it is difficult to thin the existing method due to the inclusion of fluorescent lamps or light guide plates, the backlight using the light-emitting element of the present embodiment has the characteristics of being thin and lightweight.

[0858] 3-2. Other organic devices

[0859] In addition to being used for the organic electroluminescent element, the polycyclic aromatic compound of the present invention can also be used for manufacturing organic field effect transistors, organic thin film solar cells, etc.

[0860] An organic field effect transistor is a transistor that controls current by using an electric field generated by voltage input. In addition to having a source electrode and a drain electrode, a gate electrode is also provided. An organic field effect transistor is a transistor that, when a voltage is applied to the gate electrode, an electric field is generated, and the flow of electrons (or holes) flowing between the source electrode and the drain electrode can be arbitrarily blocked to control the current. Compared with a single transistor (bipolar transistor), a field effect transistor is easier to miniaturize and is commonly used as an element for forming an integrated circuit, etc.

[0861] Regarding the structure of the organic field effect transistor, generally, as long as the source electrode and the drain electrode are grounded to the organic semiconductor active layer formed using the polycyclic aromatic compound of the present invention, and further, the gate electrode is provided with an insulating layer (dielectric layer) in contact with the organic semiconductor active layer interposed therebetween. As its element structure, for example, the following structures can be cited.

[0862] (1) Substrate / Gate electrode / Insulator layer / Source electrode and drain electrode / Organic semiconductor active layer

[0863] (2) Substrate / Gate electrode / Insulator layer / Organic semiconductor active layer / Source electrode and drain electrode

[0864] (3) Substrate / Organic semiconductor active layer / Source electrode and drain electrode / Insulator layer / Gate electrode

[0865] (4) Substrate / source electrode and drain electrode / organic semiconductor active layer / insulating layer / gate electrode

[0866] The organic field-effect transistor configured in the above-described manner can be applied as a pixel driving switch element of a liquid crystal display or an organic electroluminescent display using an active matrix driving method, etc.

[0867] The organic thin-film solar cell has a structure in which an anode such as ITO, a hole transport layer, a photoelectric conversion layer, an electron transport layer, and a cathode are laminated on a transparent substrate such as glass. The photoelectric conversion layer has a p-type semiconductor layer on the anode side and an n-type semiconductor layer on the cathode side. According to its physical properties, the polycyclic aromatic compound of the present invention can be used as a material for the hole transport layer, p-type semiconductor layer, n-type semiconductor layer, and electron transport layer. In the organic thin-film solar cell, the polycyclic aromatic compound of the present invention can function as a hole transport material or an electron transport material. In addition to the above, the organic thin-film solar cell may suitably include a hole blocking layer, an electron blocking layer, an electron injection layer, a hole injection layer, a smoothing layer, etc. Known materials used in the organic thin-film solar cell can be suitably selected and used in combination in the organic thin-film solar cell.

[0868] 4. Wavelength conversion material

[0869] The polycyclic aromatic compound of the present invention can be used as a wavelength conversion material.

[0870] Currently, active research is being conducted on applying multi-colorization technology based on a color conversion method to liquid crystal displays, organic EL displays, lighting, etc. So-called color conversion is to convert the light emitted from a light-emitting body into light with a longer wavelength. For example, it means converting ultraviolet light or blue light into green light or red light emission. By forming a film of the wavelength conversion material having the above-described color conversion function and combining it with a blue light source, for example, it is possible to extract the three primary colors of blue, green, and red, that is, white light, from the blue light source. By using such a white light source formed by combining a blue light source and a wavelength conversion film having a color conversion function as a light source unit and combining it with a liquid crystal driving part and a color filter, it is possible to manufacture a full-color display. In addition, without a liquid crystal driving part, it can be directly used as a white light source. For example, it can be applied as a white light source for light-emitting diode (LED) lighting, etc. In addition, by using a blue organic EL element as a light source and combining it with a wavelength conversion film that converts blue light into green light and red light, it is possible to manufacture a full-color organic EL display without using a metal mask. Furthermore, by using a blue micro-LED as a light source and combining it with a wavelength conversion film that converts blue light into green light and red light, it is possible to manufacture a low-cost full-color micro-LED display.

[0871] The polycyclic aromatic compound of the present invention can be used as the wavelength conversion material. A wavelength conversion material containing the polycyclic aromatic compound of the present invention can be used to convert ultraviolet light or light from a light source or a light-emitting element that generates blue light with a shorter wavelength into blue light or green light with high color purity suitable for use in a display device (an organic EL element-based display device or a liquid crystal display device). The adjustment of the converted color can be carried out by appropriately selecting substituents of the polycyclic aromatic compound of the present invention, the binder resin used in the wavelength conversion composition described below, and the like. The wavelength conversion material can be prepared as a wavelength conversion composition containing the polycyclic aromatic compound of the present invention. In addition, the wavelength conversion film can also be formed using the wavelength conversion composition.

[0872] In addition to the polycyclic aromatic compound of the present invention, the wavelength conversion composition may further contain a binder resin, other additives, and a solvent. As the binder resin, for example, the resins described in paragraphs 0173 to 0176 of International Publication No. 2016 / 190283 can be used. As other additives, the compounds described in paragraphs 0177 to 0181 of International Publication No. 2016 / 190283 can be used. As the solvent, reference can be made to the description of the solvent contained in the composition for forming the light-emitting layer.

[0873] The wavelength conversion film includes a wavelength conversion layer formed by curing the wavelength conversion composition. As a method for forming the wavelength conversion layer from the wavelength conversion composition, known film-forming methods can be referred to. The wavelength conversion film may only include a wavelength conversion layer formed from a composition containing the polycyclic aromatic compound of the present invention, or may also include other wavelength conversion layers (for example, a wavelength conversion layer that converts blue light into green light or red light, a wavelength conversion layer that converts blue light or green light into red light). Furthermore, the wavelength conversion film may also include a substrate layer, or a barrier layer for preventing the color conversion layer from deteriorating due to oxygen, moisture, or heat.

[0874] Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited thereto.

[0875] <Synthesis Example>

[0876] Synthesis Example (1): Synthesis of Compound (1-1)

[0877]

[0878] In a beaker containing compound (S-1-1) (1.5 g) and tert-butylbenzene (7.0 ml), a 1.6 M solution of tert-butyllithium in pentane (1.6 ml) was added at -30 °C under a nitrogen atmosphere. After the dropping was completed, the temperature was raised to 60 °C and stirred for 2 hours, and then the low-boiling components were distilled off from tert-butylbenzene. It was cooled to -30 °C and boron tribromide (0.63 g) was added, and the temperature was raised to room temperature and stirred for 0.5 hour. Subsequently, it was cooled to 0 °C again and N,N-diisopropylethylamine (0.43 ml) was added, and it was stirred at room temperature until the heat generation subsided, and then the temperature was raised to 120 °C and heated and stirred for 3 hours. The reaction solution was cooled to room temperature, an aqueous solution of sodium acetate cooled by an ice bath was added, and then heptane was added and liquid separation was carried out. Then, after purification using a silica gel short pass column (eluent: toluene), the solid obtained by distilling off the solvent under reduced pressure was dissolved in toluene, and heptane was added for reprecipitation to obtain compound (1-1) (0.35 g).

[0879] Compounds (1-2) to compounds (1-17), compounds (Ref-1-1) to compounds (Ref-1-5) were synthesized by the method described in Synthesis Example (1). Compounds (Ref-1-1) to compounds (Ref-1-5) are the compounds described in International Publication No. 2022 / 328352, and they were synthesized by the method described in the foregoing patent.

[0880]

[0881]

[0882]

[0883] The formation of the target product was confirmed by MALDI-TOF-MS (matrix-assisted laser desorption ionization time-of-flight mass spectrometry).

[0884] Table 1

[0885] Compound number MW Compound (Ref-1-1) 494.36 Compound (Ref-1-2) 535.46 Compound (Ref-1-3) 497.41 Compound (Ref-1-4) 493.38 Compound (Ref-1-5) 494.36 Compound (1-1) 823.77 Compound (1-2) 645.57 Compound (1-3) 870.00 Compound (1-4) 949.96 Compound (1-5) 605.59 Compound (1-6) 830.02 Compound (1-7) 577.54 Compound (1-8) 1128.16 Compound (1-9) 975.96 Compound (1-10) 865.97 Compound (1-11) 980.20 Compound (1-12) 975.96 Compound (1-13) 989.95 Compound (1-14) 646.56 Compound (1-15) 903.97 Compound (1-16) 709.69 Compound (1-17) 855.76

[0886] <Preparation and Evaluation of Evaporation-Type Organic EL Elements>

[0887] Each organic EL element of TTF, TADF, TAF, and PSF was prepared using each of the synthesized compound of the present invention and the comparative compound.

[0888] <TTF Composition: Examples 1-1-1 to 1-1-17 and Comparative Examples 1-1-1 to 1-1-5>

[0889] ITO (120 nm) / HI (40 nm) / HAT-CN (5 nm) / HT-1 (45 nm) / HT-2 (10 nm) / BH: Each compound described in Table 2 (97:3) (25 nm) / ET-1 (5 nm) / ET-2:Liq (1:1) (25 nm) / LiF (1 nm) / Al (100 nm)

[0890] The chemical structures of the compounds used in the preparation of the device are shown below.

[0891]

[0892] A 26 mm × 28 mm × 0.7 mm glass substrate ((manufactured by Opto Science Co., Ltd.)) with an ITO film formed by sputtering to a thickness of 180 nm and polished to 120 nm was used as the transparent support substrate. The transparent support substrate was fixed to the substrate holder of a commercially available evaporation apparatus (manufactured by Showa Vacuum Co., Ltd.), and molybdenum evaporation boats containing HI, HAT-CN, HT-1, HT-2, BH, each compound described in Table 2, ET-1, and ET-2, and aluminum nitride evaporation boats containing Liq, LiF, and aluminum were installed.

[0893] The following layers were sequentially formed on the ITO film of the transparent support substrate. The vacuum chamber was evacuated to 5 × 10 -4 Pa. First, HI was heated and evaporated to a film thickness of 40 nm, then HAT-CN was heated and evaporated to a film thickness of 5 nm, then HT-1 was heated and evaporated to a film thickness of 45 nm, and then HT-2 was heated and evaporated to a film thickness of 10 nm to form a hole layer composed of four layers. Then, BH and each compound described in Table 2 were heated simultaneously and evaporated to a film thickness of 25 nm to form a light-emitting layer. The evaporation rate was adjusted so that the mass ratio of BH to each compound described in Table 2 was approximately 97:3. In addition, ET-1 was heated and evaporated to a film thickness of 5 nm, and then ET-2 and Liq were heated simultaneously and evaporated to a film thickness of 25 nm to form an electron layer composed of two layers. The evaporation rate was adjusted so that the mass ratio of ET-2 to Liq was approximately 50:50. The evaporation rate of each layer was 0.01 - 1 nm / second. Subsequently, LiF was heated and evaporated at an evaporation rate of 0.01 - 0.1 nm / second to a film thickness of 1 nm, and then aluminum was heated and evaporated to a film thickness of 100 nm to form a cathode, thereby obtaining an organic EL device.

[0894] <TADF Structure: Examples 2-1-1 to 2-1-17 and Comparative Examples 2-1-1 to 2-1-5>

[0895] ITO (50 nm) / HAT-CN (10 nm) / HT-1 (60 nm) / SiCzCz (5 nm) / SiCzCz:SiTrzCz2: Each compound described in Table 2 (60:39:1) (35 nm) / mSiTrz (5 nm) / mSiTrz:Liq (1:1) (30 nm) / LiF (1 nm) / Al (100 nm)

[0896] A 26 mm × 28 mm × 0.7 mm glass substrate ((manufactured by Opto Science Co., Ltd.)) with ITO formed by sputtering to a thickness of 200 nm ground to 50 nm was used as the transparent support substrate. The transparent support substrate was fixed to the substrate holder of a commercially available evaporation apparatus (manufactured by Showa Vacuum Co., Ltd.), and molybdenum evaporation boats containing HAT-CN, HT-1, SiCzCz, SiTrzCz2, each compound described in Table 2, mSiTrz, and Liq, and tungsten evaporation boats containing LiF and aluminum were installed respectively.

[0897] The following layers were sequentially formed on the ITO film of the transparent support substrate. The vacuum chamber was evacuated to 5×10 -4Pa. First, heat HAT-CN and perform evaporation deposition in such a way that the film thickness becomes 10 nm to form a hole injection layer. Then, heat HT-1 and perform evaporation deposition in such a way that the film thickness becomes 60 nm to form a hole transport layer (1), and heat SiCzCz and perform evaporation deposition in such a way that the film thickness becomes 5 nm to form a hole transport layer (2). Then, heat SiCzCz, SiTrzCz2, and each compound described in Table 2 simultaneously and perform evaporation deposition in such a way that the film thickness becomes 35 nm to form a light-emitting layer. Adjust the evaporation rate so that the mass ratio of SiCzCz, SiTrzCz2, and each compound described in Table 2 is approximately 60:39:1. Then, heat mSiTrz and perform evaporation deposition in such a way that the film thickness becomes 5 nm to form an electron transport layer (1), and heat mSiTrz and Liq and perform evaporation deposition in such a way that the film thickness becomes 30 nm to form an electron transport layer (2). Adjust the evaporation rate so that the mass ratio of SiTrz and Liq is approximately 1:1. The evaporation rate of each layer is 0.01 - 1 nm / second. Subsequently, heat LiF and perform evaporation deposition at an evaporation rate of 0.01 - 0.1 nm / second in such a way that the film thickness becomes 1 nm, and then heat aluminum and perform evaporation deposition in such a way that the film thickness becomes 100 nm to form a cathode, thereby obtaining an organic EL element. At this time, the evaporation rate of aluminum is adjusted to 1 - 10 nm / second. In addition, SiCzCz in the light-emitting layer corresponds to a hole-transporting host material, and SiTrzCz2 corresponds to an electron-transporting host material.

[0898] <TAF Structure: Examples 3-1-1 to 3-1-17, Comparative Examples 3-1-1 to 3-1-5>

[0899] ITO(50 nm) / HAT-CN(10 nm) / HT-1(60 nm) / SiCzCz(5 nm) / SiCzCz:SiTrzCz2:TADF-1:Each compound described in Table 2 (60:26:13:1)(35 nm) / mSiTrz(5 nm) / mSiTrz:Liq(1:1)(30 nm) / LiF(1 nm) / Al(100 nm)

[0900] Except for the light-emitting layer, it was fabricated in the same manner as the TADF structure. In the light-emitting layer, SiCzCz, SiTrzCz2, (TADF-1), and each compound described in Table 2 were heated simultaneously and evaporated to a film thickness of 35 nm. Adjust the evaporation rate so that the mass ratio of SiCzCz, SiTrzCz2, (TADF-1), and each compound described in Table 2 is approximately 60:26:13:1.

[0901] <PSF Structure: Examples 4-1-1 to 4-1-17, Comparative Examples 4-1-1 to 4-1-5>

[0902] ITO (50 nm) / HAT-CN (10 nm) / HT-1 (60 nm) / SiCzCz (5 nm) / SiCzCz:SiTrzCz2:PtON-TBBI: Each compound described in Table 2 (60:26:13:1) (35 nm) / mSiTrz (5 nm) / mSiTrz:Liq (1:1) (30 nm) / LiF (1 nm) / Al (100 nm)

[0903] The (TADF-1) of the TAF structure was replaced with PtON-TBBI, and the device was fabricated in the same manner.

[0904] The chemical structures of the compounds used in the preparation of the device are shown below.

[0905]

[0906] [Evaluation]

[0907] The evaluation items include driving voltage (V), emission wavelength (nm), CIE chromaticity (x, y), external quantum efficiency (%), maximum wavelength (nm) and full width at half maximum (nm) of the emission spectrum, etc. These evaluation items can be measured, for example, at a value of 1000 cd / m 2 during emission.

[0908] The quantum efficiency of the light-emitting device has an internal quantum efficiency and an external quantum efficiency. The internal quantum efficiency represents the ratio of the external energy injected as electrons (or holes) into the light-emitting layer of the light-emitting device that is purely converted into photons. On the other hand, the external quantum efficiency is calculated based on the amount of photons released to the outside of the light-emitting device. A part of the photons generated in the light-emitting layer is absorbed or continuously reflected inside the light-emitting device and is not released to the outside of the light-emitting device. Therefore, the external quantum efficiency is lower than the internal quantum efficiency.

[0909] The measurement methods of the spectral radiance (emission spectrum) and the external quantum efficiency are as follows. Using a voltage / current generator R6144 manufactured by ADVANTEST Corporation, apply a voltage to the device until the luminance reaches 1000 cd / m 2The component emits light due to the voltage. Using a spectro-radiance meter SR-3AR manufactured by Topcon Corporation, the spectro-radiance in the visible light region was measured from a direction perpendicular to the light-emitting surface. Assuming the light-emitting surface is a perfect diffuser, the value obtained by dividing the measured spectro-radiance value of each wavelength component by the wavelength energy and multiplying by π is the number of photons at each wavelength. Subsequently, the number of photons was integrated over the entire observed wavelength region and set as the total number of photons released from the component. The value obtained by dividing the applied current value by the elementary charge was set as the number of carriers injected into the component, and the value obtained by dividing the total number of photons released from the component by the number of carriers injected into the component is the external quantum efficiency. In addition, the full width at half maximum of the emission spectrum was obtained from the width between the upper and lower wavelengths whose intensity reaches 50% with the maximum emission wavelength as the center.

[0910] A DC voltage was applied with the ITO electrode as the anode and the LiF / aluminum electrode as the cathode, and the characteristics during light emission were measured at 1000 cd / m 2 In addition, for the TTF-structured component, the time (lifetime) to maintain a brightness of 95% or more of the initial brightness was measured, and for the TADF-structured, TAF-structured, and PSF-structured components, the time (lifetime) to maintain a brightness of 50% or more of the initial brightness was measured. In addition, the emission peaks of the components were all in the range of 450 - 470 nm. The results are shown in Table 2.

[0911] Table 2

[0912]

[0913]

[0914] From the obtained results, it can be seen that compared with the components of the comparative examples using compounds having a skeleton corresponding to the compounds of the examples, the components of the examples achieve high efficiency and long lifetime.

[0915] Explanation of reference numerals

[0916] 100: Organic electroluminescent element

[0917] 101: Substrate

[0918] 102: Anode

[0919] 103: Hole injection layer

[0920] 104: Hole transport layer

[0921] 105: Light-emitting layer

[0922] 106: Electron transport layer

[0923] 107: Electron injection layer

[0924] 108: Cathode

Claims

1. A polycyclic aromatic compound, wherein: The polycyclic aromatic compound is represented by the following formula (1): In formula (1), Ring A, Ring B, Ring C, Ring D and Ring E are independently substituted or unsubstituted aryl rings, or substituted or unsubstituted heteroaryl rings, wherein at least one of the A ring, the B ring, the C ring, the D ring and the E ring is a substituted or unsubstituted monocyclic heteroaryl ring, wherein at least one of the rings A, B, C, D and E has a group represented by formula (2) as a substituent, L is independently a single bond, >O, >NR NX 、>C(-R CX )2. -C(-R CX )=C(-R CX )-、>Si(-R IX )2, >S, >CO, >CS, >SO, >SO2, >SeO, >SeO2, >PO, >B(-R PX ) or>Se, R NX , R CX , R IX and R PX are independently hydrogen, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted alkyl, or substituted or unsubstituted cycloalkyl, the two R CX can be bonded to each other to form a ring, the two R IX can bond to each other to form a ring, In the structure, at least one selected from the group consisting of an aryl ring and a heteroaryl ring may be condensed with at least one cycloalkane, the cycloalkane may be substituted with at least one substituent, and at least one -CH2- in the cycloalkane may be substituted with -O-. In formula (2), * indicates the bonding position to the aryl ring or heteroaryl ring, Ring F is a substituted or unsubstituted aryl ring, or a substituted or unsubstituted heteroaryl ring, R is a substituted or unsubstituted aryl ring, a substituted or unsubstituted heteroaryl ring, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted cycloalkyl group, In formula (1) and formula (2), at least one hydrogen may be substituted by deuterium, cyano or halogen, at least one nitrogen may be substituted by nitrogen-15, at least one sulfur may be substituted by sulfur-33, sulfur-34 or sulfur-36, at least one oxygen may be substituted by oxygen-17 or oxygen-18, at least one carbon may be substituted by carbon-13, and at least one boron may be substituted by boron-11.

2. The polycyclic aromatic compound according to claim 1, wherein Formula (1) is represented by the following formula (1'): In formula (1'), L has the same definition as L in formula (1), Z is independently -C(-R ZE )=or -N=, wherein at least one of Z is -N=, R ZE are independently selected from the group consisting of hydrogen, deuterium, halogen, cyano, nitro, substituted or unsubstituted silyl, substituted or unsubstituted amino, substituted or unsubstituted alkyl having 1 to 10 carbon atoms, substituted or unsubstituted cycloalkyl having 3 to 30 carbon atoms, substituted or unsubstituted aryl having 6 to 30 carbon atoms, substituted or unsubstituted heteroaryl having 2 to 30 carbon atoms, and the group represented by formula (2'), wherein the substituents substituted on adjacent atoms may be bonded to each other to form a ring, Among them, R ZE At least one of them has a group represented by formula (2'), In formula (2'), R has the same definition as R in formula (2), and * indicates ZE The bonding position.

3. The polycyclic aromatic compound according to claim 2, wherein R is a substituted or unsubstituted aryl ring, a substituted or unsubstituted heteroaryl ring, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted cycloalkyl group.

4. The polycyclic aromatic compound according to claim 2, wherein Formula (1') is represented by one of the following chemical formulas (1'-1) to (1'-7): In the chemical formulas (1'-1) to (1'-7), L has the same definition as L in formula (1), At least one ring has a group represented by the formula (2) as a substituent.

5. The polycyclic aromatic compound according to claim 2, wherein Formula (1') is represented by the following formula (1"): In formula (1"), Z has the same meaning as in formula (1').

6. The polycyclic aromatic compound according to claim 5, wherein Formula (1") is represented by any one of the following chemical formulas (1"-1) to (1"-7): In the chemical formula (1"-1) to the chemical formula (1"-7), At least one ring has a group represented by the formula (2) as a substituent.

7. The polycyclic aromatic compound according to claim 5, wherein Formula (1") is represented by any one of the following chemical formulas (1"-1) to (1"-4), (1"-6) and (1"-7): In chemical formula (1"-1) to chemical formula (1"-4), chemical formula (1"-6) and chemical formula (1"-7), At least one ring has a group represented by the formula (2) as a substituent.

8. The polycyclic aromatic compound according to claim 1, wherein Formula (2) is represented by any one of the following chemical formulas (2-1) to (2-7): In Chemical Formulae (2-1) to (2-7), * represents a bonding position to an aryl ring or a heteroaryl ring.

9. The polycyclic aromatic compound according to claim 1, wherein Formula (1) is represented by one of the following chemical formulas:

10. An organic electroluminescent element, in, include: a pair of electrodes, consisting of an anode and a cathode; and an organic layer disposed between the pair of electrodes, The organic layer includes the polycyclic aromatic compound according to any one of claims 1 to 9.

11. The organic electroluminescent element according to claim 10, wherein: The organic layer is a light-emitting layer.

12. The organic electroluminescent element according to claim 11, wherein The light emitting layer includes a host material and the polycyclic aromatic compound as a dopant material.

13. The organic electroluminescent element according to claim 12, wherein: The main material is an anthracene compound, a fluorene compound or a dibenzo Compound.

14. The organic electroluminescent element according to claim 11, wherein The light-emitting layer includes a host material, a thermally activated delayed fluorescent substance or a phosphorescent material, and a polycyclic aromatic compound as a light-emitting dopant.

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