Polycyclic aromatic compound, organic electroluminescent element, and display device or lighting device

Abstract

Provided are: a novel compound which is useful as a material for an organic device such as an organic EL element; a polycyclic aromatic compound; an organic electroluminescent element; and a display device or a lighting device. A polycyclic aromatic compound having a structure composed of one or more structural units represented by formula (1); a-C rings, P rings, and Q rings are aryl rings or the like, X is > N-RNX (RNX is an aryl group or the like), > O, or > S (where the structure includes at least one group represented by formula (X) as a substituent of the aryl ring among the A-C rings or RNX, ZX is-CH =, RN is a substituent, LX is a single bond, and X is a single bond. At least one selected from the group consisting of aryl rings and heteroaryl rings in the structure may be condensed by at least one cycloalkane, and at least one hydrogen in the structure may be substituted with deuterium. # imgabs0 #

Description

Technical Field

[0001] The present invention relates to a polycyclic aromatic compound and also to an organic device such as an organic electroluminescent element, an organic field effect transistor, and an organic thin film solar cell, as well as a display device and a lighting device using the polycyclic aromatic compound. Background Art

[0002] In the past, display devices using light-emitting elements that perform electroluminescence have been studied in various ways because they can achieve power saving or thinning, and organic electroluminescent elements containing organic materials have been actively studied because they can be easily lightweight or large-scaled. In particular, the development of organic materials having light-emitting properties such as blue or green, which are one of the three primary colors of light, and the development of organic materials having charge transport capabilities including holes, electrons, etc. (having the possibility of becoming semiconductors or superconductors) have been actively studied so far, regardless of whether they are polymer compounds or low molecular weight compounds.

[0003] An organic electroluminescence (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 including an organic compound. The layers including the organic compound include a light-emitting layer, a charge transport / injection layer for transporting or injecting charges such as holes and electrons, and various organic materials suitable for these layers have been developed.

[0004] Among them, Patent Documents 1 and 2 disclose that polycyclic aromatic compounds containing boron are effectively used as materials for organic electroluminescent devices, etc. It is reported that the organic electroluminescent devices containing the polycyclic aromatic compounds have good external quantum efficiency.

[0005] [Prior art literature]

[0006] [Patent Document]

[0007] [Patent Document 1] International Publication No. 2015 / 102118

[0008] [Patent Document 2] International Publication No. 2018 / 212169 Summary of the invention

[0009] [Problems to be solved by the invention]

[0010] As described above, various materials have been developed as materials used in organic EL elements. However, in order to increase the selection of materials for organic EL elements, it is desired to develop a material containing a compound different from conventional ones.

[0011] An object of the present invention is to provide a novel compound which can be effectively used as a material for an organic device such as an organic EL element.

[0012] [Technical means to solve the problem]

[0013] The inventors have conducted intensive research to solve the above-mentioned problems and have found that, in compounds having a structure containing boron similar to the compounds described in Patent Documents 1 and 2, polycyclic aromatic compounds capable of manufacturing highly efficient and long-life organic EL devices can be obtained, thereby completing the present invention. That is, the present invention provides the following polycyclic aromatic compounds, and further provides organic device materials containing the following polycyclic aromatic compounds.

[0014] <1> A polycyclic aromatic compound having a structure consisting of one or two or more structural units represented by formula (1);

[0015] [Chemistry 1]

[0016]

[0017] In formula (1),

[0018] Ring A, Ring B and Ring C are each independently a substituted or unsubstituted aryl ring or a substituted or unsubstituted heteroaryl ring,

[0019] X is independently >NR NX 、>O、>C(-R CX )2、>Si(-R IX )2、>S or >Se, R NX , R CX and R IX 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 Can bond to each other to form a ring, two R IX Can bond with each other to form a ring, R NX , R CX and R IX can be connected to the R NX , the R CX or the R IX One or two bonds of the ring to which X is bonded,

[0020] wherein the structure comprises at least one group represented by formula (X) as a substituent of the aryl ring or the heteroaryl ring in ring A, ring B or ring C, or R NX , R CX or RIX ,

[0021] [Chemistry 2]

[0022]

[0023] In formula (X),

[0024] The position of the wavy line indicates the bonding position of the group represented by formula (X).

[0025] The P ring and the Q ring are each independently a substituted or unsubstituted aryl ring or a substituted or unsubstituted heteroaryl ring,

[0026] Z X For -C(-R ZX )=or-N=,R ZX is hydrogen or a substituent,

[0027] R N is a substituent,

[0028] L X is a single bond or a divalent linking group,

[0029] At least one of the aryl rings and heteroaryl rings in the structure 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-,

[0030] In the structure, at least one hydrogen may be replaced by deuterium, and at least one nitrogen may be replaced by nitrogen-15( 15 N) substituted, at least one sulfur may be replaced by sulfur-33( 33 S), sulfur-34 ( 34 S) or sulfur-36( 36 S), at least one oxygen may be replaced by oxygen-17( 17 O) or oxygen-18 ( 18 O) substituted, at least one carbon may be substituted by carbon-13 ( 13 C) substituted, at least one boron may be substituted by boron-11( 11 B) Replacement.

[0031] <2> The polycyclic aromatic compound according to <1>, wherein formula (X) is represented by formula (X-1);

[0032] [Chemistry 3]

[0033]

[0034] In formula (X-1),

[0035] Z X , R N and LX and Z in formula (X) X , R N and L X They have the same meaning respectively.

[0036] Z are each independently -C(-R Z )=or-N=,R Z is hydrogen or a substituent.

[0037] <3> The polycyclic aromatic compound according to <2>, wherein

[0038] Z is -C(-R Z )=,

[0039] L X is a single bond, a substituted or unsubstituted phenylene group, or a substituted or unsubstituted biphenylene group.

[0040] <4> The polycyclic aromatic compound according to <3>, wherein formula (X) is represented by formula (X-2).

[0041] [Chemistry 4]

[0042]

[0043] <5> The polycyclic aromatic compound according to any one of <1> to <4>, wherein R N It is a substituent having 6 to 26 atoms excluding hydrogen.

[0044] <6> The polycyclic aromatic compound according to any one of <1> to <5>, which is represented by formula (1X1) or formula (1X2-1);

[0045] [Chemistry 5]

[0046]

[0047] In formula (1X1) and formula (1X2-1),

[0048] Ring A, Ring B and Ring C have the same meanings as Ring A, Ring B and Ring C in Formula (1), respectively.

[0049] X has the same meaning as X in formula (1),

[0050] Z C are independently -C(-R C )=or=N-,R C are each independently hydrogen or a substituent,

[0051] At least one of the group consisting of the aryl ring and the heteroaryl ring selected from the free formula (1X1) and the formula (1X2-1) 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-,

[0052] In each of formula (1X1) and formula (1X2-1), at least one hydrogen may be substituted by deuterium, and at least one nitrogen may be substituted by nitrogen-15( 15 N) substituted, at least one sulfur may be replaced by sulfur-33( 33 S), sulfur-34 ( 34 S) or sulfur-36( 36 S), at least one oxygen may be replaced by oxygen-17( 17 O) or oxygen-18 ( 18 O) substituted, at least one carbon may be substituted by carbon-13 ( 13 C) substituted, at least one boron may be substituted by boron-11( 11 B) Replacement.

[0053] <7> The polycyclic aromatic compound according to <6>, which is represented by the formula (1X1).

[0054] <8> The polycyclic aromatic compound according to <7>, which is represented by any of the following formulas;

[0055] [Chemistry 6]

[0056]

[0057] [Chemistry 7]

[0058]

[0059] [Chemistry 8]

[0060]

[0061] [Chemistry 9]

[0062]

[0063] In the formula, Me is methyl, tBu is tert-butyl, and D is deuterium.

[0064] <9> The polycyclic aromatic compound according to <6>, which is represented by the formula (1X2-1). <10> The polycyclic aromatic compound according to <9>, which is represented by any of the following formulas;

[0065] [Chemistry 10]

[0066]

[0067] [Chemistry 11]

[0068]

[0069] [Chemistry 12]

[0070]

[0071] In the formula, tBu is tert-butyl.

[0072] <11> An organic electroluminescent element comprising: a pair of electrodes including an anode and a cathode; and an organic layer disposed between the pair of electrodes, the organic layer containing the polycyclic aromatic compound according to any one of <1> to <10>.

[0073] <12> The organic electroluminescent element according to <11>, wherein the organic layer is a light-emitting layer.

[0074] <13> The organic electroluminescent element according to <12>, wherein the light-emitting layer includes at least one selected from the group consisting of an auxiliary dopant and a phosphorescent material.

[0075] <14> A display device or a lighting device, comprising the organic electroluminescent element according to any one of <11> to <13>.

[0076] [Effects of the Invention]

[0077] According to the present invention, there is provided a novel polycyclic aromatic compound which is effectively used as a material for an organic device such as an organic electroluminescent element. The polycyclic aromatic compound of the present invention can be used to produce an organic device such as an organic electroluminescent element. BRIEF DESCRIPTION OF THE DRAWINGS

[0078] Figure 1 This is a schematic cross-sectional view showing an example of an organic electroluminescent element.

[0079] [Explanation of Symbols]

[0080] 100: Organic electroluminescent element

[0081] 101: Substrate

[0082] 102: Anode

[0083] 103: Hole injection layer

[0084] 104: Hole transport layer

[0085] 105: Luminous layer

[0086] 106: Electron transport layer

[0087] 107: Electron injection layer

[0088] 108: Cathode DETAILED DESCRIPTION

[0089] 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 "~" refers to the range including the numerical values ​​described before and after "~" as the lower limit and the upper limit. In addition, in this specification, the "hydrogen" in the description of the structural formula refers to "hydrogen atom (H)". Similarly, "carbon atom (C)" is sometimes referred to as "carbon".

[0090] In the present specification, "adjacent groups" refer to two groups respectively bonded to two adjacent atoms (two atoms directly bonded by a covalent bond) in a structural formula.

[0091] In the present specification, "Me" represents a methyl group, "Et" represents an ethyl group, "nBu" represents a normal butyl group, "tBu" represents a tertiary butyl group, "iBu" represents an isobutyl group, "secBu" represents a secondary butyl group, "nPr" represents a normal propyl group, "iPr" represents an isopropyl group, "tAm" represents a tert-amyl group, "2EH" represents a 2-ethylhexyl group, "tOct" represents a tert-octyl group, "Ph" represents a phenyl group, "Mes" represents mesityl (2,4,6-trimethylphenyl), "Ad" represents a 1-adamantyl group, "Tf" represents a trifluoromethanesulfonyl group, "TMS" represents a trimethylsilyl group, and "D" represents a deuterium group.

[0092] In this specification, an organic electroluminescent element may be referred to as an organic EL element.

[0093] In this specification, the chemical structure or substituent is sometimes represented by the carbon number, but the carbon number when the chemical structure is substituted with a substituent, or when the substituent is further substituted with a substituent, etc., refers to the carbon number of the chemical structure or the substituent, and does not refer to the total carbon number of the chemical structure and the substituent, or the total carbon number of the substituent and the substituent. For example, the so-called "substituent B with carbon number Y substituted by substituent A with carbon number X" means that "substituent A with carbon number X" is substituted on "substituent B with carbon number Y", and the carbon number Y is not the total carbon number of substituent A and substituent B. In addition, for example, the so-called "substituent B with carbon number Y substituted by substituent A" means that "substituent A (without carbon number limitation)" is substituted on "substituent B with carbon number Y", and the carbon number Y is not the total carbon number of substituent A and substituent B.

[0094] <Description of Ring and Substituent>

[0095] First, the details of the rings and substituents used in the present specification are described below.

[0096] Examples of the “aryl ring” in the present specification include an aryl ring having 6 to 30 carbon atoms, 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.

[0097] Specific examples of the "aryl ring" include a benzene ring that is a monocyclic ring system, a biphenyl ring that is a bicyclic ring system, a naphthalene ring and an indene ring that are a condensed bicyclic ring system, a terphenyl ring (meta-terphenyl, o-terphenyl, p-terphenyl) that is a tricyclic ring system, an acenaphthene ring, fluorene ring, phenanthren ring, anthracene ring that are a condensed tricyclic ring system, a triphenylene ring, a pyrene ring, a tetracene ring, The ring is a perylene ring, a pentacene ring, etc. of a condensed five-ring system. In addition, the fluorene ring, the benzofluorene ring, and the indene ring also include structures in which the fluorene ring, the benzofluorene ring, the cyclopentane ring, etc. are spiro-bonded. In addition, the fluorene ring, the benzofluorene ring, and the indene ring also include rings in which two of the two hydrogen atoms of the methylene group in the structure are replaced by alkyl groups such as methyl groups described later as the first substituent to form dimethylfluorene rings, dimethylbenzofluorene rings, dimethylindene rings, etc.

[0098] As the "heteroaryl ring" in the present specification, 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, further preferably a heteroaryl ring having 2 to 15 carbon atoms, and particularly preferably a heteroaryl ring having 2 to 10 carbon atoms can be mentioned. In addition, as the "heteroaryl ring", for example, a heterocyclic ring containing 1 to 5 heteroatoms selected from oxygen, sulfur, nitrogen, boron, selenium, phosphorus, and tellurium as ring-constituting atoms other than carbon can be mentioned.

[0099] Specific examples of the "heteroaryl ring" include a pyrrole ring, an oxazole ring, an isoxazole ring, a thiazole ring, an isothiazole ring, an imidazole ring, an oxadiazole ring (such as a furazan 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 phenoxathiol ring, a phenoxazine ring, a phenothiazine ring, a phenazine ring, a phenazasiline ring, an indolizine ring, a furan ring, a benzofuran ring, an isobenzofuran ring, a dibenzofuran ring, Thiophene ring, benzothiophene ring, dibenzothiophene ring, thianthrene ring, indolecarbazole ring, benzindolecarbazole ring, dibenzoindolecarbazole ring, naphthobenzofuran ring, dioxin ring, dihydroacridine ring, xanthene ring, thioxanthene ring, dibenzodioxin ring, dioxaborinaphthoanthracene ring (5,9-dioxa-13b-bora-13bH-naphtho[3,2,1-de]anthracene ring, etc.), benzoselenophene ring, dibenzoselenophene ring, azacarbazole ring, azadibenzothiophene ring, azadibenzofuran ring, azadibenzoselenophene ring, azatriphenylene ring, imidazoimidazole ring, indoloindole ring, benzofuranocarbazole ring, benzothiophenocarbazole ring, indenocarbazole ring and selenophenecarbazole ring, spiro[fluorene-9,9'-xanthene] ring, spirobis[siliconfluorene] ring, etc. In addition, among the dihydroacridine ring, xanthene ring and thioxanthene ring, two of the two hydrogen atoms of the methylene group in the structure are preferably substituted with an alkyl group such as a methyl group as described later as the first substituent to form a dimethyldihydroacridine ring, a dimethylxanthene ring, a dimethylthioxanthene ring, etc. In addition, bipyridine ring, phenylpyridine ring, pyridylphenyl ring as a bicyclic ring system, terpyridine ring, bipyridylphenyl ring, pyridylbiphenyl ring as a tricyclic ring system can also be listed as a "heteroaryl ring". In addition, the "heteroaryl ring" also includes a pyran ring.

[0100] In this specification, a substituent may be substituted with a further substituent. For example, a specific substituent may be described as "substituted or unsubstituted". This means that the specific substituent is substituted with at least one further substituent or is unsubstituted. In the same sense, it is sometimes referred to as "substitutable". In this specification, the specific substituent at this time may be referred to as a "first substituent" and the further substituent may be referred to as a "second substituent".

[0101] In the present specification, the substituent group Zα includes the substituents of the substituent group Z and the substituents represented by the formula (A30) described later.

[0102] In the present specification, the substituent group Z includes:

[0103] The aryl group may be substituted by at least one group selected from the group consisting of an aryl group, a heteroaryl group, an alkyl group, a cycloalkyl group, a cyano group and a halogen group,

[0104] The heteroaryl group may be substituted by at least one group selected from the group consisting of aryl, heteroaryl, alkyl, cycloalkyl, cyano and halogen.

[0105] The diarylamino group may be substituted by at least one group selected from the group consisting of an aryl group, a heteroaryl group, an alkyl group, a cycloalkyl group, a cyano group and a halogen group, and the two aryl groups in the diarylamino group may be bonded to each other via a linking group.

[0106] The diheteroarylamino group may be substituted by at least one group selected from the group consisting of an aryl group, a heteroaryl group, an alkyl group, a cycloalkyl group, a cyano group and a halogen group, and the two heteroaryl groups in the diheteroarylamino group may be bonded to each other via a linking group.

[0107] The arylheteroarylamino group may be substituted by at least one group selected from the group consisting of an aryl group, a heteroaryl group, an alkyl group, a cycloalkyl group, a cyano group and a halogen group, and the aryl group and the heteroaryl group in the arylheteroarylamino group may be bonded to each other via a linking group.

[0108] The diarylboryl group may be substituted by at least one group selected from the group consisting of an aryl group, a heteroaryl group, an alkyl group, a cycloalkyl group, a cyano group and a halogen group, and the two aryl groups in the diarylboryl group may be bonded via a single bond or a linking group.

[0109] The alkyl group may be substituted by at least one group selected from the group consisting of an aryl group, a heteroaryl group, a cycloalkyl group, a cyano group and a halogen group,

[0110] The cycloalkyl group may be substituted by at least one group selected from the group consisting of an aryl group, a heteroaryl group, an alkyl group, a cycloalkyl group, a cyano group and a halogen group,

[0111] The alkoxy group may be substituted by at least one group selected from the group consisting of an aryl group, a heteroaryl group, a cycloalkyl group, a cyano group and a halogen group,

[0112] The aryloxy group may be substituted by at least one group selected from the group consisting of aryl, heteroaryl, alkyl, cycloalkyl, cyano and halogen.

[0113] Substituted silyl, cyano and halogen.

[0114] The aryl group as the second substituent in each group of the substituent group Z may be further substituted by an aryl group, a heteroaryl group, an alkyl group, a cycloalkyl group, a cyano group or a halogen. Similarly, the heteroaryl group as the second substituent may be substituted by an aryl group, a heteroaryl group, an alkyl group, a cycloalkyl group, a cyano group or a halogen.

[0115] In the present specification, when referred to as a "substituent", the type of the substituent is not particularly limited, and unless otherwise specified, any substituent selected from the substituent group Z may be used. For example, when a "substituted or unsubstituted" group is substituted, the group may be substituted with at least one group selected from the substituent group Z.

[0116] In the present specification, the "aryl group" is, for example, an aryl group having 6 to 30 carbon atoms, and preferably an aryl group having 6 to 20 carbon atoms, an aryl group having 6 to 16 carbon atoms, an aryl group having 6 to 12 carbon atoms, or an aryl group having 6 to 10 carbon atoms.

[0117] Specific examples of the "aryl group" include a monovalent group obtained by removing one hydrogen atom from the above-mentioned "aryl ring". For example, it is a phenyl group which is a monocyclic ring, a biphenyl group (2-biphenyl, 3-biphenyl, or 4-biphenyl) which is a bicyclic ring, a naphthyl group (1-naphthyl or 2-naphthyl) which is a condensed bicyclic ring, a terphenyl group (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, or p-terphenyl-4-yl) which is a tricyclic ring, a condensed tricyclic acenaphthene group (1-, 3-, 4-, or 5- The invention also includes the following: a 1-, 2-, 3-, 4-, or 9-) group, a phenanthren-(1-, 2-, 3-, 4-, or 9-) group, a tetraphenyl group (5'-phenyl-m-terphenyl-2-yl, 5'-phenyl-m-terphenyl-3-yl, 5'-phenyl-m-terphenyl-4-yl, or m-quaterphenyl group) having a tetracyclic ring system, a triphenylene-(1-, 2-, or 4-) group, a pyrene-(1-, 2-, or 4-) group, or a tetracene-(1-, 2-, or 5-) group having a condensed tetracyclic ring system, or a perylene-(1-, 2-, or 3-) group, or a pentacene-(1-, 2-, 5-, or 6-) group having a condensed pentacyclic ring system. In addition, a monovalent group of spirofluorene and the like can be mentioned.

[0118] In addition, the aryl group serving as the second substituent also includes a structure in which the aryl group is substituted by at least one group selected from the group consisting of aryl groups such as phenyl (specific examples are the groups described above), alkyl groups such as methyl (specific examples are the groups described later), and cycloalkyl groups such as cyclohexyl or adamantyl (specific examples are the groups described later).

[0119] As an example thereof, there can be mentioned a group in which the 9-position of the fluorenyl group as the second substituent is substituted with an aryl group such as a phenyl group, an alkyl group such as a methyl group, or a cycloalkyl group such as a cyclohexyl group or an adamantyl group.

[0120] The “arylene group” is, for example, an arylene group having 6 to 30 carbon atoms, and preferably an arylene group having 6 to 20 carbon atoms, an arylene group having 6 to 16 carbon atoms, an arylene group having 6 to 12 carbon atoms, or an arylene group having 6 to 10 carbon atoms.

[0121] Specific examples of the "arylene group" include a divalent group obtained by removing one hydrogen atom from the above-mentioned "aryl group" (monovalent group).

[0122] The “heteroaryl group” is, for example, a heteroaryl group having 2 to 30 carbon atoms, preferably a heteroaryl group having 2 to 25 carbon atoms, a heteroaryl group having 2 to 20 carbon atoms, a heteroaryl group having 2 to 15 carbon atoms, or a heteroaryl group having 2 to 10 carbon atoms. The “heteroaryl group” contains, in addition to carbon atoms, one or more, preferably one to five heteroatoms selected from oxygen, sulfur, and nitrogen as ring-constituting atoms.

[0123] Specific examples of "heteroaryl" include monovalent groups formed by removing one hydrogen from the "heteroaryl ring". Examples include pyrrolyl, oxazolyl, isoxazolyl, thiazolyl, isothiazolyl, imidazolyl, oxadiazolyl, thiadiazolyl, triazolyl, tetrazolyl, pyrazolyl, pyridyl, pyrimidinyl, pyridazinyl, pyrazinyl, triazinyl, indolyl, isoindolyl, 1H-indazolyl, benzimidazolyl, benzoxazolyl, benzothiazolyl, 1H-benzotriazolyl, quinolyl, isoquinolyl, cinnolinyl, quinazolinyl, quinoxalinyl, phenanthrolinyl, phthalazinyl, naphthyridinyl, purinyl, pteridinyl, carbazolyl, acridinyl, phenoxathiol, phenoxazinyl, phenanthrolinyl, phenanthroline ... Thiazinyl, phenazinyl, phenazasilinyl, indolizinyl, furanyl, benzofuranyl, isobenzofuranyl, dibenzofuranyl, naphthobenzofuranyl, thienyl, benzothienyl, isobenzothienyl, dibenzothienyl, naphthobenzothienyl, a monovalent group of a benzophospholine oxide ring, a monovalent group of a dibenzophospholine oxide ring, furazanyl, thianthrenyl, indolecarbazolyl, benzindolecarbazolyl, dibenzoindolecarbazolyl, imidazolinyl, or oxazolinyl, etc. In addition, a monovalent group of spiro[fluorene-9,9'-xanthene], a monovalent group of spirobis[silafluorene], and a monovalent group of benzoselenophene can be mentioned.

[0124] In addition, the heteroaryl group as the second substituent also includes a structure in which the heteroaryl group is substituted by at least one group selected from the group consisting of aryl groups such as phenyl (specific examples are the groups described above), alkyl groups such as methyl (specific examples are the groups described later), and cycloalkyl groups such as cyclohexyl or adamantyl (specific examples are the groups described later).

[0125] As an example, the 9-position of the carbazolyl group as the second substituent is substituted by an aryl group such as a phenyl group, an alkyl group such as a methyl group, or a cycloalkyl group such as a cyclohexyl group or an adamantyl group. In addition, a nitrogen-containing heteroaryl group such as a pyridyl group, a pyrimidyl group, a triazine group, a carbazolyl group, etc., which is further substituted by a phenyl group or a biphenyl group, is also included in the heteroaryl group as the second substituent.

[0126] The “heteroarylene group” is, for example, a heteroarylene group having 2 to 30 carbon atoms, preferably a heteroarylene group having 2 to 25 carbon atoms, a heteroarylene group having 2 to 20 carbon atoms, a heteroarylene group having 2 to 15 carbon atoms, or a heteroarylene group having 2 to 10 carbon atoms. In addition, the “heteroarylene group” is, for example, a divalent group such as a heterocycle containing 1 to 5 heteroatoms selected from oxygen, sulfur, and nitrogen as ring-constituting atoms in addition to carbon.

[0127] Specific examples of the "heteroarylene group" include a divalent group obtained by removing one hydrogen atom from the above-mentioned "heteroaryl group" (monovalent group).

[0128] The "diarylamino group" is an amino group substituted with two aryl groups, and the description of the above-mentioned "aryl group" can be referred to for details of the aryl group.

[0129] The "diheteroarylamino group" is an amino group substituted with two heteroaryl groups, and the description of the "heteroaryl group" can be referred to for details of the heteroaryl group.

[0130] The "arylheteroarylamino group" is an amino group substituted with an aryl group or a heteroaryl group, and the description of the above-mentioned "aryl group" and "heteroaryl group" can be cited for the details of the above-mentioned aryl group and heteroaryl group.

[0131] The two aryl groups in the diarylamino group as the first substituent may be bonded to each other via a linking group, the two heteroaryl groups in the diheteroarylamino group as the first substituent may be bonded to each other via a linking group, and the aryl and heteroaryl groups in the arylheteroarylamino group as the first substituent may be bonded to each other via a linking group. Here, the description of "bonding via a linking group" is as shown below, for example, it means that the two phenyl groups of the diphenylamino group form a bond through a linking group. In addition, the description is also applicable to the diheteroarylamino group and the arylheteroarylamino group formed by aryl or heteroaryl groups.

[0132] [Chemistry 13]

[0133]

[0134] (* indicates the bond position)

[0135] Specific examples of the linking group include: >O, >NR X 、>C(-R X )2. -C(-R X )=C(-R X)-、>Si(-R X )2,>S,>CO,>CS,>SO,>SO2,>SeO,>SeO2,>PO,>B(-R X ) and >Se. R X are independently alkyl, cycloalkyl, aryl, or heteroaryl, which may be substituted by alkyl, cycloalkyl, aryl, or heteroaryl. X )2. -C(-R X )=C(-R X )-、>Si(-R X )2 Each of the two R X Can be linked to the group X via a single bond or Y bond with each other to form a ring. Y , can be listed as >O, >NR Y 、>C(-R Y )2、>Si(-R Y )2, >S, >CO, >CS, >SO, >SO2, and >Se, R Y are independently alkyl, cycloalkyl, aryl or heteroaryl, which may be substituted by alkyl, cycloalkyl, aryl or heteroaryl. Y is>C(-R Y )2 and>Si(-R Y )2, the two R Y The alkylene group may be substituted with an alkylene group. 2X Replacement, R 2X are independently alkyl, cycloalkyl, substituted silyl, aryl and heteroaryl, which may be substituted by alkyl, cycloalkyl, substituted silyl or aryl. X )=C(-R X )-The two Rs in X They may be bonded to each other and form an aryl ring (such as a benzene ring) or a heteroaryl ring together with these bonded C=C. X )=C(-R X )- can be an arylene group (such as 1,2-phenylene) or a heteroarylene group.

[0136] In addition, when simply describing “diarylamino”, “diheteroarylamino” or “arylheteroarylamino” in the present specification, unless otherwise specified, descriptions such as “two aryl groups in the diarylamino group may be bonded to each other via a linking group”, “two heteroaryl groups in the diheteroarylamino group may be bonded to each other via a linking group” and “the aryl and heteroaryl groups in the arylheteroarylamino group may be bonded to each other via a linking group” are respectively added.

[0137] "Diarylboryl" is a boron group substituted with two aryl groups, and the details of the aryl group can be referred to the description of the "aryl group". In addition, the two aryl groups may be bonded via a single bond or a linking group (for example, -CH=CH-, -CR=CR-, -C≡C-, >NR, >O, >S, >CO, >C=S, >S=O, >S(=O)2, >Se(=O), >Se(=O)2, >P(=O), >B(-R), >C(-R)2, >Si(-R)2, or >Se). Here, R of -CR=CR-, R of >NR, R of >B(-R), R of >C(-R)2, and R of >Si(-R) are aryl, heteroaryl, diarylamino, alkyl, alkenyl, alkynyl, cycloalkyl, alkoxy, or aryloxy, and at least one hydrogen in the R may be further substituted by an aryl, heteroaryl, alkyl, alkenyl, alkynyl, or cycloalkyl. In addition, two adjacent Rs may be bonded to each other to form a ring, thereby forming a cycloalkylene, arylene, and heteroarylene. For details of the substituents listed here, the descriptions of "aryl", "arylene", "heteroaryl", "heteroarylene", and "diarylamino" described above, as well as the descriptions of "alkyl", "alkenyl", "alkynyl", "cycloalkyl", "cycloalkylene", "alkoxy", and "aryloxy" described later may be cited. In the present specification, when simply describing a "diarylboryl group", unless otherwise specified, it is assumed that "two aryl groups in the diarylboryl group may be bonded to each other via a single bond or a linking group" is included.

[0138] "Alkyl" can be any of straight chain and branched chain, for example, a straight chain alkyl group with 1 to 24 carbon atoms or a branched chain alkyl group with 3 to 24 carbon atoms, preferably an alkyl group with 1 to 18 carbon atoms (branched chain alkyl group with 3 to 18 carbon atoms), an alkyl group with 1 to 12 carbon atoms (branched chain alkyl group with 3 to 12 carbon atoms), an alkyl group with 1 to 6 carbon atoms (branched chain alkyl group with 3 to 6 carbon atoms), an alkyl group with 1 to 5 carbon atoms (branched chain alkyl group with 3 to 5 carbon atoms), an alkyl group with 1 to 4 carbon atoms (branched chain alkyl group with 3 to 4 carbon atoms), etc.

[0139] Specific examples of “alkyl” include methyl, ethyl, n-propyl, isopropyl, 1-ethyl-1-methylpropyl, 1,1-diethylpropyl, 1,1,2-trimethylpropyl, 1,1,2,2-tetramethylpropyl, 1-ethyl-1,2,2-trimethylpropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, 2-ethylbutyl, 1,1-dimethylbutyl, 3,3-dimethylbutyl, 1,1-diethylbutyl, 1-ethyl-1-methylbutyl, 1-propyl-1-methylbutyl, 1,1,3-trimethylbutyl, 1-ethyl-1,3-dimethylbutyl, n-pentyl, isopentyl, neopentyl, t-pentyl (t-amyl), 1-methylpentyl, 2-propylpentyl, 1,1-dimethylpentyl, 1-ethyl-1-methylpentyl, 1-propyl-1-methylpentyl, 1-butyl-1-methylpentyl, 1,1,4-trimethylpentyl, n-hexyl, 1-methylhexyl, 2-ethylhexyl, 1,1-dimethylhexyl, 1-ethyl-1-methylhexyl, 1,1,5-trimethylhexyl, 3,5,5-trimethylhexyl, n-heptyl, 1-methylheptyl, 1-hexylheptyl, 1,1-dimethylheptyl, 2,2-dimethylheptyl, 2,6-dimethyl-4-heptyl, n-octyl, tert-octyl (1,1,3,3-tetramethylbutyl), 1,1-dimethyloctyl, n-nonyl, n-decyl, 1-methyldecyl, n-undecyl, n-dodecyl, n-tridecyl, n-tetradecyl, n-pentadecyl, n-hexadecyl, n-heptadecyl, n-octadecyl, or n-icosyl.

[0140] The "alkylene group" is a divalent group obtained by removing any hydrogen atom from an "alkyl group", and examples thereof include a methylene group, an ethylene group, and a propylene group.

[0141] Regarding the "alkenyl group", please refer to the description of the "alkyl group". It is a group in which the CC single bond in the structure of the "alkyl group" is replaced by a C=C double bond, and also includes a group in which not only one but more than two single bonds are replaced by double bonds (also called a diene group or a triene group).

[0142] The "alkenylene group" is a divalent group obtained by removing any hydrogen atom of an "alkenyl group", and examples thereof include a vinylene group.

[0143] Regarding the “alkynyl group”, reference may be made to the description of the “alkyl group”, which is a group in which the C-C single bond in the structure of the “alkyl group” is replaced by a C≡C triple bond, and also includes a group in which not only one but two or more single bonds are replaced by triple bonds (also called a di-alkynyl group or a tri-alkynyl group).

[0144] The “cycloalkyl group” is, for example, a cycloalkyl group having 3 to 24 carbon atoms, preferably a cycloalkyl group having 3 to 20 carbon atoms, a cycloalkyl group having 3 to 16 carbon atoms, a cycloalkyl group having 3 to 14 carbon atoms, a cycloalkyl group having 3 to 12 carbon atoms, a cycloalkyl group having 5 to 10 carbon atoms, a cycloalkyl group having 5 to 8 carbon atoms, a cycloalkyl group having 5 to 6 carbon atoms, or a cycloalkyl group having 5 carbon atoms.

[0145] Specific examples of "cycloalkyl" include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl, or alkyl (especially methyl) substituents having 1 to 5 carbon atoms or 1 to 4 carbon atoms, 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[2.2.1]heptyl (norbornyl), bicyclo[2.2.2]octyl, adamantyl, diadamantyl, decahydronaphthyl, or decahydroazulyl.

[0146] The “cycloalkylene group” is, for example, a cycloalkylene group having 3 to 24 carbon atoms, preferably a cycloalkylene group having 3 to 20 carbon atoms, a cycloalkylene group having 3 to 16 carbon atoms, a cycloalkylene group having 3 to 14 carbon atoms, a cycloalkylene group having 3 to 12 carbon atoms, a cycloalkylene group having 5 to 10 carbon atoms, a cycloalkylene group having 5 to 8 carbon atoms, a cycloalkylene group having 5 to 6 carbon atoms, or a cycloalkylene group having 5 carbon atoms.

[0147] Specific examples of the "cycloalkylene group" include a structure in which one hydrogen atom is removed from the above-mentioned "cycloalkyl group" (monovalent group) to give a divalent group.

[0148] The "cycloalkenyl group" includes a group having a structure in which at least one set of single bonds between two carbon atoms in the "cycloalkyl group" becomes a double bond (for example, a group in which -CH2-CH2- is substituted with -CH=CH-), and a group that is not equivalent to an aryl group. Specifically, 1-cyclohexenyl, 1-cyclopentenyl, etc. can be mentioned.

[0149] The "alkoxy group" is a group represented by "Alk-O-(Alk is an alkyl group)", and the description of the "alkyl group" can be cited for details of the alkyl group.

[0150] The "aryloxy group" is a group represented by "Ar-O-(Ar is an aryl group)", and the description of the "aryl group" can be cited for details of the aryl group.

[0151] The “substituted silyl group” is, for example, a silyl group substituted with at least one of an aryl group, an alkyl group, and a cycloalkyl group, and is preferably a triarylsilyl group, a trialkylsilyl group, a tricycloalkylsilyl group, a dialkylcycloalkylsilyl group, or an alkyldicycloalkylsilyl group.

[0152] The "triarylsilyl group" is a silyl group substituted with three aryl groups, and the description of the "aryl group" can be cited for details of the aryl groups.

[0153] Specific examples of the “triarylsilyl group” include triphenylsilyl, diphenylmononaphthylsilyl, monophenyldinaphthylsilyl, and trinaphthylsilyl groups.

[0154] The “trialkylsilyl group” is a silyl group substituted with three alkyl groups, and the description of the “alkyl group” mentioned above can be referred to for details of the alkyl groups.

[0155] Specific examples of “trialkylsilyl” include trimethylsilyl, triethylsilyl, tri-n-propylsilyl, triisopropylsilyl, tri-n-butylsilyl, triisobutylsilyl, tri-sec-butylsilyl, tri-tert-butylsilyl, ethyldimethylsilyl, n-propyldimethylsilyl, isopropyldimethylsilyl, n-butyldimethylsilyl, isobutyldimethylsilyl, sec-butyldimethylsilyl, tert-butyldimethylsilyl, methyldiethylsilyl, n-propyldimethylsilyl, tert-butyldiethylsilyl, methyldi-n-propylsilyl, ethyldi-n-propylsilyl, n-butyldi-n-propylsilyl, sec-butyldi-n-propylsilyl, tert-butyldi-n-propylsilyl, methyldiisopropylsilyl, ethyldiisopropylsilyl, n-butyldiisopropylsilyl, sec-butyldiisopropylsilyl, or tert-butyldiisopropylsilyl.

[0156] The "tricycloalkylsilyl group" is a silyl group substituted with three cycloalkyl groups, and the description of the "cycloalkyl group" mentioned above can be cited for the details of the cycloalkyl group.

[0157] Specific examples of the “tricycloalkylsilyl group” include tricyclopentylsilyl and tricyclohexylsilyl groups.

[0158] The "dialkylcycloalkylsilyl group" is a silyl group substituted with two alkyl groups and one cycloalkyl group, and the description of the "alkyl group" and the "cycloalkyl group" can be cited for details of the alkyl group and the cycloalkyl group.

[0159] The "alkyldicycloalkylsilyl group" is a silyl group substituted with one alkyl group and two cycloalkyl groups, and the description of the "alkyl group" and the "cycloalkyl group" can be cited for details of the alkyl group and the cycloalkyl group.

[0160] The "halogen" is fluorine, chlorine, bromine or iodine, preferably fluorine, chlorine or bromine, more preferably fluorine or chlorine, further preferably fluorine.

[0161] When the group is substituted with a cyano group or a halogen, it is also preferred that all or part of the hydrogen atoms in the aryl ring or the heteroaryl ring in the structure are substituted with a cyano group or a halogen.

[0162] The substituent represented by formula (A30) has the following structure.

[0163] [Chemistry 14]

[0164]

[0165] In formula (A30),

[0166] Ak is hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted cycloalkyl or substituted or unsubstituted cycloalkenyl, at least one -CH2- in the alkyl, cycloalkyl and cycloalkenyl may be substituted by -O- or -S-,

[0167] R Ak is a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted alkyl or a substituted or unsubstituted cycloalkyl, R Ak It can be bonded to Ak through a linking group or a single bond, and * is the bonding position.

[0168] In formula (A30), Ak is the substituent, and is not conjugated with the non-covalent electron pair on N, so that the non-covalent electron pair can be conjugated with the π electron of the bonding target, and a larger wavelength change can be achieved compared to the case where an aromatic group or the like exists at the same position. In addition, the same is true for the influence on the multiple resonance effect, and a greater improvement in the thermally activated delayed fluorescence (TADF) property can be achieved.

[0169] R Ak Preferred is an aryl group which may be substituted by an alkyl group or a cycloalkyl group, a heteroaryl group which may be substituted by an alkyl group or a cycloalkyl group, an alkyl group or a cycloalkyl group, more preferably an aryl group which may be substituted by an alkyl group, a heteroaryl group which may be substituted by an alkyl group, an alkyl group or a cycloalkyl group, further preferably an aryl group which may be substituted by an alkyl group, and particularly preferably a phenyl group which may be substituted by a methyl group.

[0170] In formula (A30), Ak is preferably an alkyl group having 1 to 6 carbon atoms or a cycloalkyl group having 3 to 14 carbon atoms, more preferably an alkyl group having 1 to 4 carbon atoms or a cycloalkyl group having 3 to 8 carbon atoms, more preferably an alkyl group having 1 to 4 carbon atoms, and still more preferably a methyl group.

[0171] R Ak It may be the same as or different from Ak, but is preferably different.

[0172] R Ak It can be bonded to Ak via a linking group or a single bond. Examples of the linking group include >O, >S, or >Si(-R)2. R of >Si(-R)2 is hydrogen, an aryl group having 6 to 12 carbon atoms, an alkyl group having 1 to 6 carbon atoms, or a cycloalkyl group having 3 to 14 carbon atoms. AkExamples of the structure bonded to Ak via a linking group or a single bond include the following structures.

[0173] [Chemistry 15]

[0174]

[0175] In the above formulas, * represents the bonding position.

[0176] <When two groups bonded to the same atom are bonded to each other>

[0177] In the present specification, when it is mentioned that two groups bonded to the same atom can be bonded to each other to form a ring, they can be bonded via a single bond or a linking group (these are also collectively referred to as a bonding group). Examples of the linking group include -CH2-CH2-, -CHR-CHR-, -CR2-CR2-, -CH=CH-, -CR=CR-, -C≡C-, -N(-R)-, -O-, -S-, -C(-R)2-, -C(=O)-, -C(=S)-, -S(=O)-, -S(=O)2-, -Se(=O)-, -Se(=O)2-, -P(=O)-, -B(-R)-, -Si(-R)2- or -Se-. For example, the following structures can be mentioned. In addition, the R of -CHR-CHR-, the R of -CR2-CR2-, the R of -CR=CR-, the R of -N(-R)-, the R of -C(-R)2-, the R of -B(-R)-, and the R of -Si(-R)2- are independently hydrogen, aryl which may be substituted by alkyl or cycloalkyl, heteroaryl which may be substituted by alkyl or cycloalkyl, alkyl which may be substituted by cycloalkyl, alkenyl which may be substituted by alkyl or cycloalkyl, alkynyl which may be substituted by alkyl or cycloalkyl, or cycloalkyl which may be substituted by alkyl or cycloalkyl. In addition, two adjacent Rs may be bonded to each other to form a ring, and may form a cycloalkylene group, an arylene group, or a heteroarylene group.

[0178] [Chemistry 16]

[0179]

[0180] As the bonding group, a single bond, -CR=CR-, -N(-R)-, -O-, -S-, -C(-R)2-, -Si(-R)2-, and -Se- are preferred as the linking group; a single bond, -CR=CR-, -N(-R)-, -O-, -S-, and -C(-R)2- are more preferred as the linking group; a single bond, -CR=CR-, -N(-R)-, -O-, and -S- are further preferred as the linking group; and a single bond is most preferred.

[0181] The position at which the two Rs are bonded via a bonding group is not particularly limited as long as it is a position at which bonding is possible, but it is preferred that the two Rs are bonded at the most adjacent position. For example, when the two groups are phenyl groups, it is preferred that the two Rs are bonded to each other at the ortho position (position 2) based on the bonding position (position 1) of "C" or "Si" in the phenyl group (refer to the structural formula).

[0182] <Stereoisomers, etc.>

[0183] The polycyclic aromatic compound of the present invention may exist as enantiomers or diastereomers depending on the type of substituents, but any stereoisomer in any pure form, any mixture of stereoisomers, racemates, etc. are all included in the scope of the present invention regardless of the structural formula described.

[0184] 1. Polycyclic aromatic compounds

[0185] <Description of the overall structure of the compound>

[0186] Regarding polycyclic aromatic compounds formed by linking aromatic rings using heteroelements such as boron, nitrogen, oxygen, and sulfur, it has been found that they have a large highest occupied molecular orbital (HOMO)-lowest unoccupied molecular orbital (LUMO) gap (band gap Eg in the film). The reason is that the aromaticity of the 6-membered ring containing the heteroelement is low, and the reduction of the HOMO-LUMO gap accompanying the expansion of the conjugated system is suppressed. In addition, it was found that the HOMO-LUMO gap can be arbitrarily changed according to the type of heteroelement and the method of connection. It is believed that the reason is that the energy of HOMO and LUMO can be arbitrarily changed according to the spatial expansion and energy of the empty orbital or lone pair of the heteroelement.

[0187] These polycyclic aromatic compounds have single occupied molecular orbitals (SOMO) 1 and SOMO 2 in the excited state localized on each atom due to the electronic disturbance of the heteroelement, thereby narrowing the half-value width of the fluorescence emission peak, and thus, when used as a dopant for an organic EL element, high color purity emission can be obtained. For the same reason, ΔE(S1T1) becomes small, showing thermally activated delayed fluorescence, and when used as an emission dopant for an organic EL element, high efficiency can be obtained.

[0188] Furthermore, by introducing a substituent, the energies of HOMO and LUMO can be arbitrarily changed, and thus the ionization potential and the electron affinity can be optimized according to the surrounding materials.

[0189] The polycyclic aromatic compound of the present invention is consistent with the polycyclic aromatic compound formed by linking aromatic rings using hetero elements such as boron, nitrogen, oxygen, and sulfur as described above. The polycyclic aromatic compound of the present invention is a polycyclic aromatic compound having a structure composed of one or more structural units represented by formula (1) and containing at least one group represented by formula (X) at a specific position (hereinafter sometimes referred to as "polycyclic aromatic compound containing structural units represented by formula (1)").

[0190] [Chemistry 17]

[0191]

[0192] The following describes the details of symbols in each structure.

[0193] <Formula (X)>

[0194] Formula (X) represents a substituent bonded at the position of the wavy line. The polycyclic aromatic compound containing the structural unit represented by formula (1) contains the substituent represented by formula (X) as a substituent of the aryl ring or heteroaryl ring in ring A, ring B or ring C, or R NX , R CX or R IX In the present invention, it is found that by introducing a substituent represented by formula (X) at a predetermined position of a polycyclic aromatic compound, the efficiency of an organic EL device using the compound is further increased and the life is further prolonged. This is believed to be because the substituent R of the structure represented by formula (X) N The dopant protrudes into the upper space of the plane of the main skeleton composed of rings A, B and C and covers at least a part of the plane, thereby suppressing the interaction with the adjacent molecules. In particular, in TADF assisting fluorescence (TAF) elements or phosphor-sensitized fluorescent (PSF) elements, the emitting dopant becomes the lowest excited triplet state (T1 state) due to Dexter type energy transfer, which becomes a factor of reduced efficiency and shortened life. However, if the molecules are not in contact, Dexter type energy transfer will not occur, so it is believed that by suppressing the interaction between molecules, the T1 state can be avoided.

[0195] However, the present invention is not particularly limited to these principles.

[0196] In formula (X), the P ring and the Q ring are independently substituted or unsubstituted aryl rings or substituted or unsubstituted heteroaryl rings. The P ring and the Q ring each form a divalent group having a bond on two atoms (preferably carbon) adjacent to each other on the aryl ring or heteroaryl ring in the structure. That is, the P ring and the Q ring are respectively bonded to NR by the two bonds. N N and including Z X The carbon atom on the 6-membered ring of the ring is bonded. In each of the P ring and the Q ring, the ring in which the atoms having the two bonding bonds are set as the ring-constituting atoms is preferably a 5-membered ring or a 6-membered ring, and more preferably a 6-membered ring. The ring may be further condensed with other rings. Examples of 6-membered rings include: benzene rings, pyridine rings, pyrazine rings, pyrimidine rings, etc. Examples of 6-membered rings that are further condensed with other rings include: naphthalene rings, quinoline rings, benzofuran rings, benzothiophene rings, indole rings, benzoselenophene rings, dibenzofuran rings, dibenzothiophene rings, carbazole rings, dibenzoselenophene rings, etc. Examples of 5-membered rings include: furan rings, thiophene rings, pyrrole rings, thiazole rings, selenophene rings, etc. Examples of 5-membered rings that are further condensed with other rings include: benzofuran rings, benzothiophene rings, indole rings, benzoselenophene rings, etc.

[0197] The aryl ring or heteroaryl ring in the P ring and the Q ring is preferably a benzene ring, a naphthalene ring or a pyridine ring, and more preferably a benzene ring.

[0198] In the substituted or unsubstituted aryl ring or substituted or unsubstituted heteroaryl ring in the P ring and the Q ring, as the substituent when referring to "substituted or unsubstituted (substituted or unsubstituted)", at least one substituent selected from the substituent group Zα can be listed. In addition, the substituent may also be a substituted or unsubstituted diarylphosphino group such as a diphenylphosphino group. When there are multiple substituents, the multiple substituents may be the same or different from each other. As the substituent in the P ring and the Q ring, preferably a substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group.

[0199] The P ring and the Q ring may be the same as or different from each other, but are preferably the same from the viewpoint of easy production.

[0200] R N is a substituent, and the substituent may be at least one substituent selected from the substituent group Zα. In addition, the substituent may be a substituted or unsubstituted diarylphosphino group such as a diphenylphosphino group. N, for example, substituted or unsubstituted alkyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, more specifically, the group represented by the formula (tR) described later, adamantyl, phenyl which may be substituted by an alkyl group, or biphenyl which may be substituted by an alkyl group. Among these, from the viewpoint of the purpose of more widely covering the plane of the main skeleton and the ease of control, a substituent having 4 to 30 atoms other than hydrogen is preferred, and a substituent having 6 to 26 atoms is more preferred. It is also preferred that at least one substituent selected from the group consisting of an aryl ring and a heteroaryl ring in the substituent is subjected to cycloalkane condensation as described later.

[0201] About R N As a more specific example, any of the following substituents can be cited. In addition, in the following formulae, * represents a bonding position.

[0202] [Chemistry 18]

[0203]

[0204] [Chemistry 19]

[0205]

[0206] Among the above, more preferred are substituents having 6 to 26 atoms excluding hydrogen. As the substituent having 6 to 26 atoms, for example, the following substituents can be preferably mentioned.

[0207] [Chemistry 20]

[0208]

[0209] Among the above, a phenyl group is particularly preferred from the viewpoint of easy availability and production.

[0210] Two R's N The two may be the same or different from each other, but are preferably the same from the viewpoint of easy production.

[0211] In formula (X), Z X For -C(-R ZX )=or-N=,R ZX is hydrogen or a substituent. X , preferably -C(-R ZX )=. As R ZX When R is a substituent, the substituent may be any substituent selected from the substituent group Zα, and preferably any substituent selected from the substituent group Z. More specifically, regarding R as a substituent, ZX, preferably a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, a substituted or unsubstituted diarylamino group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group, a substituted silyl group, or a cyano group, and more preferably an aryl group which may be substituted by an alkyl group, an alkyl group, or a cycloalkyl group which may be substituted by an alkyl group.

[0212] R in formula (X) ZX Preferred is hydrogen.

[0213] In formula (X), L X is a single bond or a divalent linking group. X , preferably a single bond, a substituted or unsubstituted phenylene, or a substituted or unsubstituted biphenylene, more preferably a single bond or a substituted or unsubstituted 1,4-phenylene, and further preferably a single bond. In addition, preferably: X The length of R N A large volume is formed that covers at least a portion of the main skeleton plane.

[0214] The group represented by formula (X) is preferably a group represented by formula (X-1).

[0215] [Chemistry 21]

[0216]

[0217] In formula (X-1),

[0218] Z X , R N and L X and Z in formula (X) X , R N and L X Z are independently -C(-R Z )=or-N=,R Z is hydrogen or a substituent. Z is preferably -C(-R Z )=. R Z Preferably, one or two are substituents and the others are hydrogen, and more preferably, one is a substituent and the others are hydrogen. Z As a substituent, R Z Preferred examples of include the substituents described above as preferred examples of the substituents in the P ring and the Q ring.

[0219] The group represented by formula (X) is preferably a group represented by formula (X-2).

[0220] [Chemistry 22]

[0221]

[0222] In formula (X-2),

[0223] R N and R in formula (X) N The meanings are the same, and the preferred ranges are also the same.

[0224] The group represented by formula (X) is preferably directly bonded to the aryl ring or heteroaryl ring in ring A, ring B or ring C of formula (1), or X is >NR NX R NX , more preferably directly bonded to an aryl ring or heteroaryl ring in ring A, ring B or ring C. Further preferably directly bonded to an aryl ring or heteroaryl ring in ring A.

[0225] The polycyclic aromatic compound including the structural unit represented by the formula (1) preferably includes 1 to 3 groups represented by the formula (X).

[0226] <Description of Ring Structure in Compound>

[0227] In formula (1), "A", "B", and "C" in the circle are symbols representing the ring structure represented by each circle. The structure represented by formula (1) has a structure in which at least three aromatic rings as the A ring, the B ring, and the C ring are connected by hetero elements such as boron, oxygen, sulfur, or nitrogen to form a ring structure. The formed ring structure is a condensed ring structure composed of at least 5 rings.

[0228] The A ring, the B ring and the C ring are each independently a substituted or unsubstituted aryl ring or a substituted or unsubstituted heteroaryl ring.

[0229] Ring A forms a trivalent group having a bond on three consecutive atoms (preferably carbon) on the ring of the aryl ring or heteroaryl ring in its structure. Ring A is bonded to two X and B (boron) through the three bonds. X can also be bonded to ring A at another position as described later to make ring A a tetravalent group or a pentavalent group. The ring in which the atom having the bond is set as a ring-constituting atom in ring A is preferably a 5-membered ring or a 6-membered ring, and more preferably a 6-membered ring. The ring can be further condensed with other rings. Examples of 6-membered rings include: benzene ring, pyridine ring, pyrazine ring, pyrimidine ring, etc. Examples of 6-membered rings further condensed with other rings include: naphthalene ring, quinoline ring, dibenzofuran ring, dibenzothiophene ring, carbazole ring, etc. Examples of 5-membered rings include: furan ring, thiophene ring, pyrrole ring, thiazole ring, etc. Examples of 5-membered rings further condensed with other rings include: benzofuran ring, benzothiophene ring, indole ring, etc. In addition, an indene ring can also be mentioned as the condensed ring.

[0230] The aryl ring or heteroaryl ring in the A ring is preferably a benzene ring.

[0231] Both the B ring and the C ring form a divalent group with a bond on two atoms (preferably carbon) adjacent to each other on the ring of the aryl ring or heteroaryl ring in its structure. The B ring is bonded to X and B (boron) through the two bonds, and the C ring is bonded to X and B (boron) through the two bonds. X can also be bonded to the B ring at another position as described later to make the B ring a trivalent group, and X can also be bonded to the C ring at another position as described later to make the C ring a trivalent group. The ring in which the atoms having the two bonds are set as ring-constituting atoms in each of the B ring and the C ring is preferably a 5-membered ring or a 6-membered ring, and more preferably a 6-membered ring. The ring can be further condensed with other rings. Examples of 6-membered rings include: a benzene ring, a pyridine ring, a pyrazine ring, a pyrimidine ring, and the like. As the example of 6-membered ring and then condensed with other rings, can be listed: naphthalene ring, quinoline ring, benzofuran ring, benzothiophene ring, indole ring, benzoselenophene ring, dibenzofuran ring, dibenzothiophene ring, carbazole ring, dibenzoselenophene ring etc.As the example of 5-membered ring, can be listed: furan ring, thiophene ring, pyrrole ring, thiazole ring, selenophene ring etc.As the example of 5-membered ring and then condensed with other rings, can be listed: benzofuran ring, benzothiophene ring, indole ring, benzoselenophene ring etc.In addition, as condensed ring, can also list indene ring.

[0232] The aryl ring or heteroaryl ring in the B ring or the C ring is preferably a benzene ring, a benzofuran ring, a benzothiophene ring, an indene ring or a benzoselenophene ring, more preferably a benzene ring, a benzofuran ring, an indene ring or a benzothiophene ring, and further preferably a benzene ring or a benzothiophene ring.

[0233] In addition, as described later, in the polycyclic aromatic compound of the present invention having a structure composed of two or more structural units bonded in a shared ring, the A ring, the B ring or the C ring sometimes has four or five bonds. Such a structure is represented by the A' ring, the B' ring or the C' ring in the formula (1M2-1), the formula (1M2-2), the formula (1M2-3), the formula (1M2-4), the formula (1M3-1), the formula (1M3-2), the formula (1M3-3) and the formula (1M3-4) described later.

[0234] In the substituted or unsubstituted aryl ring or substituted or unsubstituted heteroaryl ring in the A ring, the B ring and the C ring, as the substituent when referring to "substituted or unsubstituted (substituted or unsubstituted)", at least one substituent selected from the substituent group Zα can be listed. In addition, the substituent may also be a substituted or unsubstituted diarylphosphino group such as a diphenylphosphino group. When there are multiple substituents, the multiple substituents may be the same or different from each other. As the substituent, preferably a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, or a substituted or unsubstituted diarylamino group, more preferably a tert-butyl group, a diphenylamino group, or a substituted or unsubstituted carbazolyl group. As preferred substituents other than these, reference may be made to the description in <Preferred Substituents> described later.

[0235] <Structure composed of one or two or more structural units>

[0236] The polycyclic aromatic compound of the present invention is a polycyclic aromatic compound having a structure composed of one or two or more structural units represented by formula (1).

[0237] The polycyclic aromatic compound having a structure consisting of one of the above structural units is a polycyclic aromatic compound represented by the formula explained above as the structural unit represented by formula (1).

[0238] A polycyclic aromatic compound having a structure composed of two or more of the structural units represented by formula (1) is a compound equivalent to a polymer of the polycyclic aromatic compound represented by the formula described above as the structural unit represented by formula (1). The polymer is preferably a dimer to a hexamer, and more preferably a dimer to a trimer. The polymer may be in the form of a plurality of the structural units in one compound, and may be in the form of bonding in a manner that any ring (A ring, B ring or C ring) contained in the structural unit is shared by a plurality of structural units, or in the form of bonding in a manner that any ring (A ring, B ring or C ring) contained in the structural unit is condensed with each other. In addition, it may be in the form of bonding in a manner that any ring (A ring, B ring or C ring) contained in the structural unit and X bonded thereto are shared by a plurality of structural units. It may also be in the form of bonding with a plurality of the structural units using a single bond, an alkylene group having 1 to 3 carbon atoms, a phenylene group, a naphthylene group or the like. Among these, a form in which the bonds are bonded so as to share a ring is preferred. The two or more structural units in the polycyclic aromatic compound having a structure composed of two or more of the structural units represented by formula (1) may be the same as or different from each other.

[0239] Examples of structures composed of two or three or more structural units bonded to each other in a shared ring are shown below.

[0240] [Chemistry 23]

[0241]

[0242] In formula (1M2-1), formula (1M2-2), formula (1M2-3), formula (1M2-4), formula (1M3-1), formula (1M3-2), formula (1M3-3) and formula (1M3-4), ring A, ring B, ring C and X have the same meanings as ring A, ring B, ring C and X in formula (1), and ring A', ring B' and ring C' are independently substituted or unsubstituted aryl rings or substituted or unsubstituted heteroaryl rings.

[0243] <Explanation of X>

[0244] In formula (1), X is independently >NR NX 、>O、>C(-R CX )2、>Si(-R IX )2.>S or>Se, R NX is hydrogen, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted alkyl, or substituted or unsubstituted cycloalkyl, R CX and R IX 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 Can bond to each other to form a ring, two R IX Can bond with each other to form a ring, R NX , R CX and R IX can be connected to the R NX , the R CX or the R IX One or two bonds in the ring to which X is bonded.

[0245] R NX It is preferably a substituted or unsubstituted aryl group or a substituted or unsubstituted heteroaryl group, more preferably a group represented by the formula (1NR) described later or a substituted or unsubstituted phenyl group, and further preferably a group represented by the formula (1NR) or an unsubstituted phenyl group. CX It is preferably a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, or a substituted or unsubstituted alkyl group, and more preferably a substituted or unsubstituted phenyl group or methyl group. IXPreferred is a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, or a substituted or unsubstituted alkyl group, and more preferred is a substituted or unsubstituted phenyl group or methyl group.

[0246] In the polycyclic aromatic compound containing the structural unit represented by formula (1) used as an emissive dopant in the light-emitting layer of the organic EL device, X is preferably independently >NR NX , >S, >O or >Se, more preferably >NR NX , >O or >S, and preferably >NR NX or >S, particularly preferably >NR NX .

[0247] As >NR NX R NX , and a group represented by the following formula (1NR) is also preferred.

[0248] [Chemistry 24]

[0249]

[0250] In the formula (1NR), ring J is a substituted or unsubstituted aryl ring, or a substituted or unsubstituted heteroaryl ring, and R J It is an optionally substituted aryl group, an optionally substituted heteroaryl group, an optionally substituted alkyl group having 4 or more carbon atoms, or an optionally substituted cycloalkyl group, and * indicates a bonding position to N (nitrogen).

[0251] The polycyclic aromatic compound of the present invention has a group represented by the formula (1NR) as R NX , the sublimation temperature becomes lower than that of similar compounds without the above-mentioned group. The reduction of the sublimation temperature means that in the sublimation refining, which is almost indispensable as a refining method for materials for organic devices such as organic EL elements requiring high purity, the refining can be carried out at a lower temperature, thereby avoiding thermal decomposition of the material. In addition, for the vacuum evaporation process, which is a powerful means for making organic devices such as organic EL elements, this also means that the process can be carried out at a lower temperature, thereby avoiding thermal decomposition of the material, and as a result, a high-performance organic device can be obtained. Although not sticking to a specific theory, it is believed that the reduction of the sublimation temperature is due to the presence of R J The bulky group represented by the formula (1NR) is contained in the molecule, thereby making the overall volume of the molecule larger.

[0252] In addition, by having a group represented by the formula (1NR) as R NXCompared with compounds without the group represented by formula (1NR), the polycyclic aromatic compound of the present invention emits light of shorter wavelength, has higher luminous efficiency, and has longer device life. Although not limited to a specific theory, it is believed that the reason is that the group represented by formula (1NR) makes the volume of the molecule larger, which can three-dimensionally protect the skeleton involved in luminescence, thereby reducing the interaction with the surrounding molecules and making it less likely to undergo decomposition reaction.

[0253] In formula (1NR), from the viewpoint of sublimation temperature and luminous efficiency, R J Preferably, it is a phenyl group having an alkyl group as a substituent. J Preferably, R J Unsubstituted phenyl is preferred.

[0254] In the formula (1NR), "J" in the circle is a symbol representing the ring structure represented by the circle, and the J ring is a substituted or unsubstituted aryl ring, or a substituted or unsubstituted heteroaryl ring. The J ring forms a divalent group having a bond on two adjacent elements (preferably carbon) on the aryl ring or heteroaryl ring in its structure, and is bonded to N (nitrogen) and R through two bonds. J Bond.

[0255] In the substituted or unsubstituted aryl ring or substituted or unsubstituted heteroaryl ring in the J ring, as the substituent mentioned in "substituted or unsubstituted (substituted or unsubstituted)", at least one substituent selected from the substituent group Zα is preferred.

[0256] Ring J is preferably a substituted or unsubstituted benzene ring, a substituted or unsubstituted benzothiophene ring, a substituted or unsubstituted benzofuran ring, or a substituted or unsubstituted indole ring, more preferably a substituted or unsubstituted benzene ring, and even more preferably an unsubstituted benzene ring.

[0257] A preferred example of the group represented by the formula (1NR) is a group represented by the formula (1NR-a).

[0258] [Chemistry 25]

[0259]

[0260] In formula (1NR-a), Z is independently -CR j = or -N =, R j and R k are independently hydrogen, any substituent selected from the substituent group Zα, R j The adjacent groups in the group may be bonded to each other and together with the j ring form an aryl ring or a heteroaryl ring, and R kThe adjacent groups in the group may be bonded to each other and form an aryl ring or a heteroaryl ring together with the k ring, and the formed ring may be substituted by at least one substituent selected from the substituent group Zα. j An example of a ring formed by adjacent groups of the ring being bonded to each other and formed together with the j ring, or R k Examples of the ring formed by bonding adjacent groups to each other together with the k ring include a naphthalene ring, a carbazole ring, an indole ring, a dibenzofuran ring, and a dibenzothiophene ring.

[0261] R k Each of them independently represents preferably hydrogen, unsubstituted alkyl or unsubstituted cycloalkyl, and more preferably hydrogen or unsubstituted alkyl.

[0262] R k Preferably, all of them are hydrogen, or at least two R k is unsubstituted alkyl or unsubstituted cycloalkyl and the other R k is hydrogen, unsubstituted alkyl or unsubstituted cycloalkyl.

[0263] Z is preferably -CR j =. R j Each of them is independently preferably hydrogen, unsubstituted alkyl or unsubstituted cycloalkyl, and more preferably hydrogen or unsubstituted alkyl.

[0264] The group represented by the formula (1NR-a) is preferably a group represented by the formula (2NR).

[0265] [Chemistry 26]

[0266]

[0267] In the formula (2NR), R j and R k With R in formula (1NR-a) j and R k They have the same meaning respectively.

[0268] In the formula (2NR), R j and R k Each is independently preferably hydrogen or unsubstituted alkyl.

[0269] In a preferred form of formula (2NR), R j and R k Preferably, both are hydrogen, that is, the group represented by the formula (2NR) is preferably 2-biphenyl.

[0270] In another preferred embodiment of formula (2NR), at least two R k is unsubstituted alkyl or unsubstituted cycloalkyl and the other R k For hydrogen.

[0271] Other preferred examples of the group represented by the formula (1NR) include groups represented by the formula (1NR-b).

[0272] [Chemistry 27]

[0273]

[0274] In formula (1NR-b), R J With R in formula (1NR) J R has the same meaning and the preferred range is also the same. jj With R J Z has the same meaning as Z in formula (1NR-a), and the preferred range is also the same. In the group represented by formula (1NR-b), preferably, Z is -CH= and R J , R jj All are unsubstituted phenyl.

[0275] Another preferred example of the group represented by the formula (1NR) includes a group represented by the formula (1NR-c).

[0276] [Chemistry 28]

[0277]

[0278] In the formula (1NR-c), R J With R in formula (1NR) J has the same meaning and the preferred range is also the same. Z has the same meaning as Z in formula (1NR-a), and the preferred range is also the same. X is >NR, >O or >S, and R of >NR is hydrogen, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted alkyl, or substituted or unsubstituted cycloalkyl. R of >NR is preferably substituted or unsubstituted aryl or substituted or unsubstituted heteroaryl, more preferably unsubstituted aryl (particularly unsubstituted phenyl).

[0279] In formula (1NR-c), Z is preferably -CR j =, two R j Preferably, they are bonded to each other and together with the J ring form an aryl ring or a heteroaryl ring. j The ring formed by bonding to each other and together with the j ring is preferably a substituted or unsubstituted benzofuran ring, a substituted or unsubstituted benzothiophene ring, or a substituted or unsubstituted indole ring, and more preferably an unsubstituted benzofuran ring, an unsubstituted benzothiophene ring, or an unsubstituted indole ring.

[0280] When the polycyclic aromatic compound of the present invention has RNX >NR of a group represented by the formula (1NR) NX When >NR NX The number of is not particularly limited. For example, it only needs to be 1 or 2. When there are a plurality of groups represented by the formula (1NR), they may be the same or different from each other, but are preferably the same.

[0281] <Description of the change of the ring structure caused by the bonding between X and the ring>

[0282] R in X NX , R CX and R IX It can be bonded to one or two rings to which X itself is bonded, respectively, through a single bond or a linking group. Specifically, in formula (1), R in X NX , R CX and R IX It may be bonded to at least one of the A ring or the B ring, or may be bonded to at least one of the A ring or the C ring via a single bond or a linking group.

[0283] As R NX , R CX and R IX Examples of the linking group when bonding to each ring include: -CH2-CH2-, -CHR-CHR-, -CR2-CR2-, -CH=CH-, -CR=CR-, -C≡C-, -N(-R)-, -O-, -S-, -C(-R)2-, -C(=O)-, -C(=S)-, -S(=O)-, -S(=O)2-, -Se(=O)-, -Se(=O)2-, -P(=O)-, -B(-R)-, -Si(-R)2- or -Se-. Among these, -CH=CH-, -CR=CR-, -N(-R)-, -O-, -S-, and -C(-R)2- are preferred, -CH=CH-, -CR=CR-, -N(-R)-, -O-, and -S- are more preferred, and -CR=CR-, -N(-R)-, -O-, and -S- are still more preferred. R of "-CHR-CHR-", R of "-CR2-CR2-", R of "-CR=CR-", R of "-N(-R)-", R of "-C(-R)2-", and R of "-Si(-R)2-" are each independently hydrogen, aryl which may be substituted by alkyl or cycloalkyl, heteroaryl which may be substituted by alkyl or cycloalkyl, alkyl which may be substituted by alkyl or cycloalkyl, alkenyl which may be substituted by alkyl or cycloalkyl, alkynyl which may be substituted by alkyl or cycloalkyl, or cycloalkyl which may be substituted by alkyl or cycloalkyl. In addition, two Rs bonded to the same atom may bond to each other to form a ring. Furthermore, two adjacent Rs may bond to each other to form a cycloalkylene ring, an arylene ring, and a heteroarylene ring. In addition, these rings may also be substituted by an alkyl group or a cycloalkyl group.

[0284] As >NR NX R NX Examples of the condensed ring formed by bonding with the benzene ring as an aryl ring in the A ring, the B ring or the C ring (c ring) include: a carbazole ring (where R is a phenyl group); NX through a single bond), a phenoxazine ring (a phenyl group R NX through -O-bonding), phenothiazine ring (phenyl R NX through -S-bonding) or acridone ring (phenyl R NX through a -C(=O)- bond).

[0285] In addition, the following partial structure (A10) may be formed by the connection as described above.

[0286] [Chemistry 29]

[0287]

[0288] In formula (A10), R A1 ~R A4 are independently hydrogen, alkyl or cycloalkyl, R A1 ~R A4 Any two to four of may be bonded to each other via a linking group or a single bond, and may be bonded to one of the two rings bonded to X at the two * positions, and bonded to the other ring at the ** position. That is, N in formula (A10) is X>NR X When>NR X N. The atoms on the ring that are bonded at the two * positions only need to be adjacent atoms (preferably carbon atoms). The partial structure represented by formula (A10) includes a NC bond with a weak bond dissociation energy (BDE), but the presence of another bond that forms the ring also promotes the reverse reaction (rebonding reaction) when the NC bond breaks, thus becoming a more stable structure. Therefore, in an organic EL element manufactured using a polycyclic aromatic compound having such a structure, it can be expected that the element life will be extended. When the structure represented by formula (A10) is included in the polycyclic aromatic compound, the number thereof can be one or two (preferably one).

[0289] In formula (A10), R A1 ~R A4 Any two to four of may be linked to each other via a linking group or a single bond.

[0290] R A1 ~R A4 Preferably, any two (R A1 and R A4, R A1 and R A4 and R A2 and R A3 , R A1 and R A2 , R A3 and R A4 , R A1 and R A2 and R A3 and R A4 ) are bonded to each other through a linking group or a single bond, and more preferably R A1 and R A4 They are bonded to each other through a linking group or a single bond. As a divalent group formed by mutual bonding, an alkylene group can be cited. At least one hydrogen in the alkylene group can be substituted by an alkyl group or a cycloalkyl group, and at least one (preferably one) -CH2- in the alkylene group can be substituted by -O- and -S-. As a divalent group formed by mutual bonding, a straight-chain alkylene group having 2 to 5 carbon atoms is preferred, a straight-chain alkylene group having 3 or 4 carbon atoms is more preferred, and a straight-chain alkylene group having 4 carbon atoms (-(CH2)4-) is further preferred. The straight-chain alkylene group having 4 carbon atoms (-(CH2)4-) is particularly preferably unsubstituted.

[0291] The remaining R not involved in the linking group or single bond A1 ~R A4 Preferably, they are each independently hydrogen or an optionally substituted alkyl group, more preferably an optionally substituted alkyl group having 1 to 6 carbon atoms, further preferably an unsubstituted alkyl group having 1 to 6 carbon atoms, and most preferably, they are all methyl groups.

[0292] That is, the partial structure represented by formula (A10) is preferably a structure represented by the following formula (A11).

[0293] [Chemistry 30]

[0294]

[0295] In formula (A11), Me is a methyl group, and is bonded to one of the two rings bonded to X at the two * positions, and is bonded to the other ring at the ** position.

[0296] <Formula (1X1) or formula (1X2-1)>

[0297] Examples of the polycyclic aromatic compound containing the structural unit represented by formula (1) include polycyclic aromatic compounds represented by formula (1X1) or formula (1X2-1).

[0298] [Chemistry 31]

[0299]

[0300] In formula (1X1) and formula (1X2-1), ring A, ring B, and ring C have the same meanings as ring A, ring B, and ring C in formula (1), and the preferred ranges are also the same. X has the same meaning as X in formula (1), and the preferred ranges are also the same. Z C are independently -C(-R C )=or=N-,R C are independently hydrogen or a substituent. At least one of the aryl rings and heteroaryl rings selected from the group consisting of the free formula (1X1) and the formula (1X2-1) 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 addition, in the formula (1X1) and the formula (1X2-1), at least one hydrogen may be substituted with deuterium, and at least one nitrogen may be substituted with nitrogen-15( 15 N) substituted, at least one sulfur may be replaced by sulfur-33( 33 S), sulfur-34 ( 34 S) or sulfur-36( 36 S), at least one oxygen may be replaced by oxygen-17( 17 O) or oxygen-18 ( 18 O) substituted, at least one carbon may be substituted by carbon-13 ( 13 C) substituted, at least one boron may be substituted by boron-11( 11 B) Replacement.

[0301] In formula (1X2-1), Z C are independently -C(-R C )=or=N-,R C are independently hydrogen or a substituent. C Preferably, both are -C(-R C )=. R located at the adjacent position of X in the c ring C Preferably, it is hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted aryl, or substituted or unsubstituted heteroaryl. C It may be a substituent represented by formula (X). C (R located at the ortho position of boron C ) is preferably hydrogen or methyl, more preferably hydrogen.

[0302] The polycyclic aromatic compound represented by the formula (1X1) preferably contains 1 to 3 groups represented by the formula (X). The polycyclic aromatic compound represented by the formula (1X2-1) preferably contains 1 to 3 groups represented by the formula (X).

[0303] Examples of the polycyclic aromatic compound represented by formula (1X1) include polycyclic aromatic compounds represented by formula (1X1-a) or formula (1X1-b).

[0304] [Chemistry 32]

[0305]

[0306] In formula (1X1-a) and formula (1X1-b), Z C are independently -C(-R C )=or-N=,R C Each of the formulas (1X1-a) and (1X1-b) is independently hydrogen or a substituent. C At least one is R C -C(-R) is a substituent represented by formula (X) C )=, or R NX , R CX or R IX is a substituent represented by formula (X). In formula (1X1-a) and formula (1X1-b), L is >NR NL 、>O、>C(-R CL )2.>S or>Se, R NL is hydrogen, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted alkyl, or substituted or unsubstituted cycloalkyl, R CL is hydrogen, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted alkyl, or substituted or unsubstituted cycloalkyl, and both R CL In formula (1X1-a) and formula (1X1-b), X 1 and X 2 and X in formula (1X1) have the same meanings as X in formula (1X1). At least one of the aryl rings and heteroaryl rings in each of formula (1X1-a) and formula (1X1-b) 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 each of formula (1X1-a) and formula (1X1-b), at least one hydrogen may be substituted with deuterium, and at least one nitrogen may be substituted with nitrogen-15( 15 N) substituted, at least one sulfur may be replaced by sulfur-33( 33 S), sulfur-34 ( 34 S) or sulfur-36( 36 S), at least one oxygen may be replaced by oxygen-17( 17 O) or oxygen-18 ( 18 O) substituted, at least one carbon may be substituted by carbon-13 (13 C) substituted, at least one boron may be substituted by boron-11( 11 B) Replacement.

[0307] In formula (1X1-a) and formula (1X1-b), Z C Preferably, each independently is -C(-R C )=.

[0308] As R in formula (1X1-a) and formula (1X1-b) C The substituent other than the substituent represented by formula (X) may include at least one substituent selected from the substituent group Zα, preferably a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, or a substituted or unsubstituted diarylamino group, more preferably a tert-butyl group, a substituted or unsubstituted diphenylamino group, or a substituted or unsubstituted N-carbazolyl group, and further preferably a tert-butyl group or a substituted or unsubstituted N-carbazolyl group. As the substituent in the substituted or unsubstituted N-carbazolyl group, a tert-butyl group and the like may be mentioned. As other preferred substituents, reference may be made to the description in <Preferred Substituents> described later.

[0309] When each ring of the formula (1X1-a) has one substituent represented by the formula (X), the R C The position of is preferably: para to boron in ring a, boron or X in ring b and ring c 1 or X 2 The other R in the ring having a substituent represented by formula (X) C Preferred is hydrogen.

[0310] The substituent represented by formula (X) is also preferably 1 or X 2 NR NX R NX .

[0311] When each ring of the formula (1X1-a) does not have a substituent represented by the formula (X), R as other substituents C The position of is preferably: para to boron in ring a, boron or X in ring b and ring c 1 or X 2 In either case, the other R of the ring C Both are preferably hydrogen.

[0312] More preferably, the a-ring is located at the para position relative to boron, the b-ring and the c-ring are located at the boron or X 1 or X 2 The para position of C , and the other RC For hydrogen.

[0313] In the formula (1X1-a), it is particularly preferred that the para position of the boron of the a ring is a substituent represented by the formula (X), and the boron of each of the b ring and the c ring or X 1 or X 2 The para position, especially boron or X 1 or X 2 The para position of the amine is a substituted or unsubstituted N-carbazolyl group.

[0314] When each ring of the formula (1X1-b) has one substituent represented by the formula (X), the R C The position of is preferably: para to boron in ring a, and boron or X in ring b. 1 or X 2 The other R in the ring having a substituent represented by formula (X) is C Preferred is hydrogen.

[0315] When each ring of the formula (1X1-b) does not have a substituent represented by the formula (X), R as other substituents C The position of is preferably: para to boron in ring a, and boron or X in ring b. 1 or X 2 In any of the above cases, the other R of each ring is C More preferably, the a-ring is in the para position relative to the boron, the b-ring is in the para position relative to the boron or X 1 or X 2 The para position of L in the C2 ring has R as a substituent C , and the other R C For hydrogen.

[0316] In the formula (1X1-a) and the formula (1X1-b), R as the b ring, c ring and c2 ring is C The substituent other than the substituent represented by formula (X) is preferably a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, or a substituted or unsubstituted diarylamino group, more preferably a tert-butyl group, a substituted or unsubstituted diphenylamino group, or a substituted or unsubstituted N-carbazolyl group, and further preferably a substituted or unsubstituted N-carbazolyl group. C The substituent other than the substituent represented by formula (X) is preferably a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, or a substituted or unsubstituted diarylamino group, more preferably a tert-butyl group, a diphenylamino group or an N-carbazolyl group, and further preferably an unsubstituted alkyl group.

[0317] The b ring and the c ring or the c2 ring in the formula (1X1-a) and the formula (1X1-b) preferably have at least one substituent, or are condensed with cycloalkane as described below. The reason is that by having a partial structure represented by the formula (X) and the b ring and the c2 ring having the above-mentioned structures, the interaction with the adjacent molecules is further suppressed.

[0318] In formula (1X1-a) and formula (1X1-b), X 1 and X 2 The definition and preferred range of are the same as those of X in formula (1X1). 1 R NX , R CX and R IX It can be bonded to at least one of the a ring or the b ring through a single bond or a linking group, 2 R NX , R CX and R IX It may be bonded to at least one of the a ring or the c ring via a single bond or a linking group. 1 R NX , R CX and R IX It can be bonded to at least one of the a ring or the b ring through a single bond or a linking group, 2 R NX , R CX and R IX It may be bonded to at least one of the a ring or the c2 ring via a single bond or a linking group.

[0319] In formula (1X1-b), when L is > NR NL R NL , preferably a substituted or unsubstituted aryl group, more preferably a phenyl group which may be substituted by an alkyl group. CL )2 CL , preferably methyl or phenyl. L is preferably >O or >S, more preferably >S.

[0320] Examples of the polycyclic aromatic compound represented by formula (1X2-1) include polycyclic aromatic compounds represented by formula (1X2-1-a) or formula (1X2-1-b).

[0321] [Chemistry 33]

[0322]

[0323] In formula (1X2-1-a) and formula (1X2-1-b), Z Care independently -C(-R C )=or-N=,R C are independently hydrogen or a substituent. C At least one is R C -C(-R) is a substituent represented by formula (X) C )=, or R NX , R CX or R IX is a substituent represented by formula (X). L is >NR NL 、>O、>C(-R CL )2、>S or >Se. R NL is hydrogen, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted alkyl, or substituted or unsubstituted cycloalkyl, R CL is hydrogen, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted alkyl, or substituted or unsubstituted cycloalkyl, and both R CL Can bond with each other to form a ring. 1 , X 2 , X 3 and X 4 They have the same meanings as X in formula (1X2-1). At least one of the groups consisting of the aryl ring and heteroaryl ring selected from formula (1X2-1-a) and formula (1X2-1-b) 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 each of formula (1X2-1-a) and formula (1X2-1-b), at least one hydrogen may be substituted with deuterium, and at least one nitrogen may be substituted with nitrogen-15( 15 N) substituted, at least one sulfur may be replaced by sulfur-33( 33 S), sulfur-34 ( 34 S) or sulfur-36( 36 S), at least one oxygen may be replaced by oxygen-17( 17 O) or oxygen-18 ( 18 O) substituted, at least one carbon may be substituted by carbon-13 ( 13 C) substituted, at least one boron may be substituted by boron-11( 11 B) Replacement.

[0324] In formula (1X2-1-a) and formula (1X2-1-b), R CThe substituent other than the substituent represented by formula (X) may include at least one substituent selected from the substituent group Zα. The substituent is preferably a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, or a substituted or unsubstituted diarylamino group, and more preferably a phenyl group, a diphenylamino group, or a carbazolyl group. For other preferred substituents, reference may be made to the description in <Preferred Substituents> described below.

[0325] In the formula (1X2-1-a) and the formula (1X2-1-b), R as a substituent represented by the formula (X) is C The position of X is more preferably: any one of the para positions of boron in the a ring and the a' ring or X in the c ring 2 , X 3 In this case, R as a substituent represented by formula (X) C The other R of the ring that exists C More preferably, it is hydrogen. C When there are two substituents represented by the formula (X), they are preferably located at the para position of the boron of the a ring and a'.

[0326] The substituent represented by formula (X) is also preferably 1 , X 2 , X 3 and X 4 NR NX R NX , in each formula, when R NX When there are two substituents represented by formula (X), the substituents represented by formula (X) are preferably contained in X 1 and X 4 (or X 2 and X 3 )middle.

[0327] In the formula (1X2-1-a) and the formula (1X2-1-b), R as a substituent other than the substituent represented by the formula (X) C The position of is more preferably the para position of the boron of the a ring and the a' ring. C More preferred is hydrogen.

[0328] The substituent at the para position to boron in the a ring and the substituent at the para position to boron in the a' ring may be the same or different. Examples of the pairing in different cases include a combination of a substituent represented by formula (X) and a diphenylamino group or a carbazole group.

[0329] In formula (1X2-1-a) and formula (1X2-1-b), X 1 , X 2 , X3 and X 4 The definition and preferred range of are the same as those of X in formula (1X2-1). 1 R NX , R CX and R IX It can be bonded to at least one of the a ring or the b ring through a single bond or a linking group, 2 R NX , R CX and R IX It can be bonded to at least one of the a ring or the c ring through a single bond or a linking group, 3 R NX , R CX and R IX It may be bonded to at least one of the a' ring or the b' ring through a single bond or a linking group, 4 R NX , R CX and R IX It may be bonded to at least one of the c ring or the a' ring via a single bond or a linking group. 1 R NX , R CX and R IX It can be bonded to at least one of the a ring or the b ring through a single bond or a linking group, 2 R NX , R CX and R IX It can be bonded to at least one of the a ring or the c ring through a single bond or a linking group, 3 R NX , R CX and R IX It may be bonded to at least one of the a' ring or the b'1 ring (L) via a single bond or a linking group, 4 R NX , R CX and R IX It may be bonded to at least one of the c ring or the a' ring via a single bond or a linking group.

[0330] In formula (1X2-1-b), when L is > NR NL R NL , preferably a substituted or unsubstituted aryl group, more preferably a phenyl group which may be substituted by an alkyl group. CL )2 CL , preferably methyl or phenyl. L is preferably >O or >S, more preferably >S.

[0331] <Preferred substituents>

[0332] In the polycyclic aromatic compounds used as emissive dopants (and in the compounds used as dopants), as a substituent containing an "alkyl group", a tertiary alkyl group represented by the following formula (tR) is one of the particularly preferred groups. 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 substituted as a second substituent on other substituents. Specifically, a diarylamino group substituted with a tertiary alkyl group represented by the formula (tR), a carbazolyl group substituted with a tertiary alkyl group represented by the formula (tR) (preferably an N-carbazolyl group) or a benzocarbazolyl group substituted with a tertiary alkyl group represented by the formula (tR) (preferably an N-benzocarbazolyl group) can be listed. Examples of substitution forms of the groups of formula (tR) for diarylamino, carbazolyl and benzocarbazolyl include substitution of a part or all of the hydrogen atoms of the aryl ring or benzene ring in these groups with groups represented by formula (tR).

[0333] [Chemistry 34]

[0334]

[0335] In the formula (tR), R a , R b and R c Each independently represents an alkyl group having 1 to 24 carbon atoms, wherein any -CH2- in the alkyl group may be substituted by -O-, and the group represented by the formula (tR) has * as a bonding position.

[0336] As R a , R b and R c The "alkyl group having 1 to 24 carbon atoms" may be any of a straight chain and a branched chain, and 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).

[0337] R in the formula (tR) a , R b and R c The total number of carbon atoms in the moiety is preferably 3 to 20, particularly preferably 3 to 10.

[0338] As R a , R b and R cSpecific 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, and n-icosyl.

[0339] Examples of the group represented by the formula (tR) include a tert-butyl group, a tert-amyl group, a 1-ethyl-1-methylpropyl group, a 1,1-diethylpropyl group, a 1,1-dimethylbutyl group, a 1-ethyl-1-methylbutyl group, a 1,1,3,3-tetramethylbutyl group, a 1,1,4-trimethylpentyl group, a 1,1,2-trimethylpropyl group, a 1,1-dimethyloctyl group, a 1,1-dimethylpentyl group, a 1,1-dimethylheptyl group, a 1,1,5-trimethylhexyl group, 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.

[0340] As the substituent, a substituent represented by formula (A30) is also preferred.

[0341] The emission wavelength can be adjusted by the steric hindrance, electron donating property, and electron withdrawing property of the structure of the substituent possessed by the compound used as a dopant (assisting dopant or emitting dopant). The group represented by the following structural formula is preferred, and a methyl group, a tert-butyl group, a tert-amyl group, a tert-octyl group, a neopentyl group, an adamantyl group, a phenyl group, an o-tolyl group, a p-tolyl group, a 2,4-xylyl group, a 2,5-xylyl group, a 2,6-xylyl group, a 2,4,6-mesityl group, a diphenylamino group, a di-p-tolylamino group, a bis(p-(tert-butyl)phenyl)amino group, a carbazolyl group, a 3,6-dimethylcarbazolyl group, a 3,6-di-tert-butylcarbazolyl group, and a phenoxy group are more preferred. A methyl group, a tert-butyl group, a tert-amyl group, a tert-octyl group, a neopentyl group, an adamantyl group, a phenyl group, an o-tolyl group, a 2,6-xylyl group, a 2,4,6-mesityl group, a diphenylamino group, a di-p-tolylamino group, a bis(p-(tert-butyl)phenyl)amino group, a carbazolyl group, a 3,6-dimethylcarbazolyl group, a 3,6-di-tert-butylcarbazolyl group, and a tribenzazepinyl group are further preferred. From the viewpoint of ease of synthesis, a group with large steric hindrance is preferred because selective synthesis can be performed. Specifically, a tert-butyl group, a tert-amyl group, a tert-octyl group, an adamantyl group, an o-tolyl group, a p-tolyl group, a 2,4-xylyl group, a 2,5-xylyl group, a 2,6-xylyl group, a 2,4,6-mesityl group, a di-p-tolylamino group, a bis(p-(tert-butyl)phenyl)amino group, a 3,6-dimethylcarbazolyl group, and a 3,6-di-tert-butylcarbazolyl group are preferred.

[0342] In the following structural formulas, * indicates a bonding position.

[0343] [Chemistry 35]

[0344]

[0345]

[0346] [Chemistry 36]

[0347]

[0348] [Chemistry 37]

[0349]

[0350] [Chemistry 38]

[0351]

[0352] [Chemistry 39]

[0353]

[0354] [Chemistry 40]

[0355]

[0356] [Chemistry 41]

[0357]

[0358] [Chemistry 42]

[0359]

[0360] [Chemistry 43]

[0361]

[0362] [Chemistry 44]

[0363]

[0364] [Chemistry 45]

[0365]

[0366] [Chemistry 46]

[0367]

[0368] [Chemistry 47]

[0369]

[0370] [Chemistry 48]

[0371]

[0372] The polycyclic aromatic compound containing the structural unit represented by formula (1) is preferably a structure containing at least one tertiary alkyl (tert-butyl or tert-amyl, etc.), neopentyl or adamantyl represented by the formula (tR), and more preferably a tertiary alkyl (tert-butyl or tert-amyl, etc.) represented by the formula (tR). The reason is that by such a bulky substituent, the intermolecular distance increases, so the luminescence quantum yield (PLQY) is improved. In addition, as a substituent, it is also preferably a diarylamino group. Furthermore, a diarylamino group substituted by a base of formula (tR), a carbazolyl group substituted by a base of formula (tR) (preferably N-carbazolyl) or a benzocarbazolyl group substituted by a base of formula (tR) (preferably N-benzocarbazolyl) is also preferred. As a substitution form of the base of formula (tR) for diarylamino, carbazolyl and benzocarbazolyl, examples of hydrogen substitution of a part or all of the hydrogen of the aryl ring or benzene ring in these groups by the base of formula (tR) can be cited.

[0373] In particular, in the substituted or unsubstituted aryl ring or substituted or unsubstituted heteroaryl ring in the A ring, B ring and C ring of the polycyclic aromatic compound containing the structural unit represented by formula (1), the substituent mentioned when "substituted or unsubstituted (substituted or unsubstituted)" preferably includes a substituted or unsubstituted N-carbazolyl group. When a compound having an N-carbazolyl group as a substituent is used as a dopant in the light-emitting layer, it is found that an organic EL element with a longer life and a lower driving voltage can be obtained. It is believed that by having an N-carbazolyl group as a substituent, the HOMO of the compound becomes deeper, the hole trap property decreases, and the driving voltage is reduced. It is also believed that carrier recombination is not easy to occur on the dopant, and the dopant is not easy to become a T1 state, thereby prolonging the life. Here, the substituent when the N-carbazolyl group has a substituent is preferably selected from the group consisting of a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, a substituted or unsubstituted alkyl group, and a substituted or unsubstituted cycloalkyl group. As the substituted or unsubstituted N-carbazolyl group, an unsubstituted N-carbazolyl group or a 3,6-di(tert-butyl)N-carbazolyl group is particularly preferred.

[0374] In the structure including the structural unit represented by formula (1), the substituent of the aryl ring or heteroaryl ring may be a substituent represented by the following formula (A20).

[0375] [Chemistry 49]

[0376]

[0377] The substituent represented by formula (A20) is bonded to two adjacent atoms on the aryl ring or heteroaryl ring at two * positions. In formula (A20), L is >NR, >O, >Si(-R)2 or >S, R of the >NR is a substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted alkyl or substituted or unsubstituted cycloalkyl, R of the >Si(-R)2 is hydrogen, a substitutable aryl, a substitutable alkyl or a substitutable cycloalkyl, and the two Rs may be bonded to each other to form a ring, and at least one of the Rs of the >NR and the >Si(-R)2 may be bonded to the aryl ring or heteroaryl ring through a linking group or a single bond,

[0378] r is an integer from 1 to 4,

[0379] R A are independently hydrogen, substituted or unsubstituted alkyl or substituted or unsubstituted cycloalkyl, any R A Can be connected to any other R through a linking group or a single bond A Mutually bonded.

[0380] Examples of the substituent include substituents represented by any of the following.

[0381] [Chemistry 50]

[0382]

[0383] In each formula, the * only needs to be bonded to two or three consecutive (adjacent) atoms on any aryl ring or heteroaryl ring.

[0384] <Cycloalkane condensation>

[0385] At least one of the group consisting of aryl rings and heteroaryl rings selected from the polycyclic aromatic compound containing the structural unit represented by formula (1) may be condensed with at least one cycloalkane. The same is true for the polycyclic aromatic compound represented by formula (1X1) or formula (1X2-1) or formula (1X1-a), formula (1X1-b), formula (1X2-1-a) or formula (1X2-1-b), and the following description is also applicable to the polycyclic aromatic compound represented by any of these formulas.

[0386] The cycloalkane may be a cycloalkane having 3 to 24 carbon atoms. At least one hydrogen in the cycloalkane may be substituted by an aryl group having 6 to 30 carbon atoms, a heteroaryl group having 2 to 30 carbon atoms, an alkyl group having 1 to 24 carbon atoms, or a cycloalkyl group having 3 to 24 carbon atoms, and at least one -CH2- in the cycloalkane may be substituted by -O-.

[0387] The cycloalkane is preferably a cycloalkane having 3 to 20 carbon atoms, wherein at least one hydrogen in the cycloalkane may be substituted by an aryl group having 6 to 16 carbon atoms, a heteroaryl group having 2 to 22 carbon atoms, an alkyl group having 1 to 12 carbon atoms, or a cycloalkyl group having 3 to 16 carbon atoms.

[0388] 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, and cycloalkanes having 5 carbon atoms.

[0389] Specific examples of cycloalkanes 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[2.2.2]octane, adamantane, diadamantane, decahydronaphthalene and decahydroazulene, and alkyl (especially methyl)-substituted, halogen (especially fluorine)-substituted and deuterium-substituted products thereof having 1 to 5 carbon atoms.

[0390] Among the examples, a structure having at least one substituent on the carbon at the α position of the cycloalkane (a carbon adjacent to the carbon at the condensation site in the cycloalkane condensed to an aryl ring or a heteroaryl ring) such as shown in the following structural formula is preferred, a structure having two substituents on the carbon at the α position is more preferred, and a structure having two substituents on both carbons at the α position is further preferred (having a total of four substituents). As the substituent, alkyl groups (especially methyl) having 1 to 5 carbon atoms, halogens (especially fluorine) and deuterium are listed. Particularly preferred is a structure having a partial structure represented by the following formula (B11) or the following formula (B12) bonded to adjacent carbon atoms in the aryl ring or the heteroaryl ring, and more preferred is a structure having a partial structure represented by the following formula (B11) bonded to adjacent carbon atoms.

[0391] [Chemistry 51]

[0392]

[0393] In formula (B11) and formula (B12), * represents a bonding position.

[0394] The number of cycloalkanes condensed on one aryl ring or heteroaryl ring is preferably 1 to 3, more preferably 1 or 2, and even more preferably 1. For example, the following shows an example in which one or more cycloalkanes are condensed on a benzene ring (phenyl). * represents the bonding position, which can be any of the carbons that constitute the benzene ring and do not constitute the cycloalkane. The cycloalkanes condensed as in formula (Cy-1-4) and formula (Cy-2-4) can also be condensed with each other. This is true whether the condensed ring (base) is an aryl ring or heteroaryl ring other than the benzene ring (phenyl), or whether the condensed cycloalkane is a cycloalkane other than cyclopentane or cyclohexane.

[0395] [Chemistry 52]

[0396]

[0397] At least one -CH2- in the cycloalkane may be substituted with -O-. For example, the following shows an example in which one or more -CH2- in the cycloalkane condensed on a benzene ring (phenyl) is substituted with -O-. This is true whether the condensed ring (base) is an aryl ring or heteroaryl ring other than the benzene ring (phenyl), or whether the condensed cycloalkane is a cycloalkane other than cyclopentane or cyclohexane.

[0398] [Chemistry 53]

[0399]

[0400] The cycloalkane may be substituted with at least one substituent, and as the substituent, any substituent selected from the substituent group Z can be cited. Among these substituents, alkyl groups (e.g., alkyl groups having 1 to 6 carbon atoms) and cycloalkyl groups (e.g., cycloalkyl groups having 3 to 14 carbon atoms) are preferred. In addition, it is also preferred that any hydrogen group is substituted with a halogen (e.g., fluorine) or deuterium. In addition, when a cycloalkyl group is substituted, it may be a substitution form that forms a spiro ring structure. For example, the following shows an example in which a spiro ring structure is formed in a cycloalkane condensed on a benzene ring (phenyl). Regarding the * in each structural formula, in the case of a benzene ring, it refers to a benzene ring contained in the skeletal structure of the compound, and in the case of a phenyl group, it refers to a bond that is substituted in the skeletal structure of the compound.

[0401] [Chemistry 54]

[0402]

[0403] Examples of the cycloalkane condensation include, first, a form in which the aryl ring or heteroaryl ring in each of the A ring, the B ring and the C ring of the polycyclic aromatic compound containing the structural unit represented by formula (1) is condensed with a cycloalkane, or a form in which the aryl ring or heteroaryl ring contained in the substituent of the aryl ring or heteroaryl ring in each of the A ring, the B ring and the C ring is condensed with a cycloalkane.

[0404] In addition, examples include a polycyclic aromatic compound containing a structural unit represented by formula (1) in which the aryl ring or heteroaryl ring of each of the P ring and Q ring in the substituent represented by formula (X) is condensed with a cycloalkane, a substituent for the aryl ring or heteroaryl ring of each of the P ring and Q ring is condensed with a cycloalkane, or L X The aryl ring and heteroaryl ring are condensed by cycloalkane.

[0405] As another embodiment of the cycloalkane condensation, a polycyclic aromatic compound containing a structural unit represented by formula (1) having, for example, R NX >NR for aromatic groups condensed from cycloalkanes NX , a diarylamino group condensed by a cycloalkane (condensed to its aryl portion), a carbazolyl group condensed by a cycloalkane (condensed to its benzene ring portion), or a benzocarbazolyl group condensed by a cycloalkane (condensed to its benzene ring portion).

[0406] In addition, by introducing a cycloalkane structure into a polycyclic aromatic compound containing a structural unit represented by formula (1), a further reduction in melting point or sublimation temperature can be expected. The situation means that in the sublimation purification which is almost indispensable as a purification method for organic devices such as organic EL elements requiring high purity, since the purification can be performed at a lower temperature, thermal decomposition of the material can be avoided. In addition, the situation is also the same for the vacuum evaporation process which is a powerful means for making organic devices such as organic EL elements. The process can be implemented at a lower temperature, so thermal decomposition of the material can be avoided, and high-performance organic devices can be obtained as a result. In addition, since the solubility in organic solvents is improved by introducing a cycloalkane structure, it can also be applied to the production of components using a coating process. Among them, the present invention is not particularly limited to these principles.

[0407] <Substitution with heavy stable isotopes>

[0408] Each element in the polycyclic aromatic compound containing the structural unit represented by formula (1) is an element containing multiple isotopes that occur naturally in a natural occurrence ratio unless otherwise specified. All or part of the elements in each structural formula may contain more than the natural occurrence ratio (for example, in the case of boron-11 ( 11 In the present specification, it is referred to as "replaced with" "heavy stable isotopes". More specifically, at least one hydrogen can be replaced with deuterium, and at least one nitrogen can be replaced 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), at least one boron may be substituted with boron-11 ( 11 B). The same is true for the structures represented by Formula (1X1), Formula (1X2-1), Formula (1X1-a), Formula (1X1-b), Formula (1X2-1-a) or Formula (1X2-1-b). This description is also applicable to the polycyclic aromatic compounds represented by Formula (1X1), Formula (1X2-1), Formula (1X1-a), Formula (1X1-b), Formula (1X2-1-a) or Formula (1X2-1-b). By substituting at least a part of the elements with heavy stable isotopes, in particular by using boron-11 ( 11 B) Substituting at least one boron can extend the life of an organic electroluminescent device using a polycyclic aromatic compound containing a structural unit represented by formula (1) as a dopant.

[0409] <Substitution using deuterium>

[0410] All or part of the hydrogen atoms in the polycyclic aromatic compound containing the structural unit represented by formula (1) may be deuterium. The same is true for the structures represented by formula (1X1) or (1X2-1) or (1X1-a), (1X1-b), (1X2-1-a) or (1X2-1-b), and the following description is also applicable to the polycyclic aromatic compounds represented by formula (1X1) or (1X2-1) or (1X1-a), (1X1-b), (1X2-1-a) or (1X2-1-b).

[0411] For example, in the polycyclic aromatic compound containing the structural unit represented by formula (1), hydrogen in the aryl ring or heteroaryl ring in the A ring, B ring and C ring, or in the substituents thereof may be substituted with deuterium, and among these, all or part of the hydrogen in the aryl or heteroaryl group may be substituted with deuterium. X All or part of the hydrogen atoms in the aryl ring and the heteroaryl ring in the formula (1) may be substituted with deuterium. In addition, from the viewpoint of durability, it is also preferred that all or part of the hydrogen atoms in the polycyclic aromatic compound containing the structural unit represented by the formula (1) be deuterated.

[0412] <Specific examples of polycyclic aromatic compounds>

[0413] Examples of the polycyclic aromatic compound containing the structural unit represented by the formula (1) include compounds represented by any of the following structural formulas.

[0414] [Chemistry 55]

[0415]

[0416] [Chemistry 56]

[0417]

[0418] [Chemistry 57]

[0419]

[0420] [Chemistry 58]

[0421]

[0422] [Chemistry 59]

[0423]

[0424] [Chemistry 60]

[0425]

[0426] [Chemistry 61]

[0427]

[0428] [Chemistry 62]

[0429]

[0430] [Chemistry 63]

[0431]

[0432] [Chemistry 64]

[0433]

[0434] [Chemistry 65]

[0435]

[0436] [Chemistry 66]

[0437]

[0438] [Chemistry 67]

[0439]

[0440] [Chemistry 68]

[0441]

[0442] [Chemistry 69]

[0443]

[0444] [Chemistry 70]

[0445]

[0446] [Chemistry 71]

[0447]

[0448] [Chemistry 72]

[0449]

[0450] [Chemistry 73]

[0451]

[0452] [Chemistry 74]

[0453]

[0454] <Method for producing polycyclic aromatic compounds>

[0455] The polycyclic aromatic compound containing the structural unit represented by formula (1) is basically firstly bonded by a bonding group (X) to ring A (a ring) and ring B (b ring) and ring C (c ring), thereby producing an intermediate (first reaction), and then, by using boron to bond ring A (a ring), ring B (b ring) and ring C (c ring), thereby producing a final product (second reaction). In the first reaction, for example, if it is an etherification reaction, general reactions such as nucleophilic substitution reaction and Ullmann reaction can be used, and if it is an amination reaction, general reactions such as Buchwald-Hartwig reaction, nucleophilic substitution reaction and Goldberg amination can be used. In addition, in the second reaction, a tandem hetero-Friedel-Crafts reaction (tandem hetero-Friedel-Crafts reaction) (continuous aromatic electrophilic substitution reaction, the same below) can be used.

[0456] As shown in the following process (1), the second reaction is a reaction of introducing boron that bonds the A ring (a ring), the B ring (b ring) and the C ring (c ring). First, the halogen atoms between the nitrogen atoms are exchanged with halogen-metal using n-butyl lithium, sec-butyl lithium or tert-butyl lithium. Then, boron trichloride or boron tribromide is added to exchange lithium-boron metals, and then a Brünster base such as N,N-diisopropylethylamine is added to perform a tandem boro-Friedel-Crafts reaction, thereby obtaining the target product. In the second reaction, a Lewis acid such as aluminum chloride may also be added to promote the reaction. In addition, the halogen atom of Cl in the formula may be any one of Cl, Br, and I, and may be appropriately selected in consideration of the reactivity of the substrate.

[0457] [Chemistry 75]

[0458]

[0459] In addition, the above process (1) mainly shows the method for producing the polycyclic aromatic compound represented by formula (1X1), but the compound represented by formula (1X2-1) can be produced by further using an additional intermediate having an A ring (a ring) and a B ring (b ring).

[0460] The intermediate having a group represented by formula (X) can be synthesized using the method described in European Patent No. 2947071 or Organic and Biomolecular Chemistry, 2021, vol. 19, #33, p. 7172-7175.

[0461] In addition, by appropriately selecting the raw materials to be used, a polycyclic aromatic compound having a substituent at a desired position can be synthesized.

[0462] In addition, the target object can also be obtained by using the same method as described in Advanced Material (2022,34,2106954) to prepare a part other than the partial structure represented by formula (X), then borate it, and bond it to the halogen body of the partial structure represented by formula (X). Alternatively, the halogen body of the part other than the partial structure represented by formula (X) and the borate of the partial structure represented by formula (X) can also be used, and the halogen type and borate can be appropriately used.

[0463] Specific examples of the solvent used in the above reaction include tert-butylbenzene and xylene.

[0464] In addition, in the synthesis method of the process (1), an example is shown in which halogen-metal exchange is performed on the halogen atoms between nitrogen atoms using butyl lithium or the like before adding boron trichloride or boron tribromide, thereby causing a tandem hetero Friedel-Crafts reaction to occur. However, the reaction can also be carried out by adding boron trichloride or boron tribromide or the like to a precursor in which the halogen is converted into hydrogen.

[0465] In addition, examples of the ortho-metallating agent used in the process (1) include alkyl lithiums such as methyl lithium, n-butyl lithium, sec-butyl lithium, and tert-butyl lithium, and organic alkali metal compounds such as lithium diisopropylamide, lithium tetramethylpiperidinide, lithium hexamethyldisilazide, and potassium hexamethyldisilazide.

[0466] Examples of the metal-boron metal exchange reagent used in the above process (1) include boron halides such as boron trifluoride, boron trichloride, boron tribromide, and boron triiodide, boron alkoxides, and boron aryloxides.

[0467] In addition, examples of the Brünster base used in the process (1) include: N,N-diisopropylethylamine, triethylamine, 2,2,6,6-tetramethylpiperidine, 1,2,2,6,6-pentamethylpiperidine, N,N-dimethylaniline, N,N-dimethyltoluidine, 2,6-dimethylpyridine, sodium tetraphenylborate, potassium tetraphenylborate, triphenylborane, tetraphenylsilane, Ar4BNa, Ar4BK, Ar3B, Ar4Si (in addition, Ar is an aromatic group such as phenyl), etc.

[0468] Examples of the Lewis acid used in the process (1) include AlCl3, AlBr3, AlF3, BF3·OEt2, BCl3, BBr3, BI3, GaCl3, GaBr3, InCl3, InBr3, In(OTf)3, SnCl4, SnBr4, AgOTf, ScCl3, Sc(OTf)3, ZnCl2, ZnBr2, Zn(OTf)2, MgCl2, MgBr2, Mg(OTf)2, LiOTf, NaOTf, KOTf, Me3SiOTf, Cu(OTf)2, CuCl2, YCl3, Y(OTf)3, TiCl4, TiBr4, ZrCl4, ZrBr4, FeCl3, FeBr3, CoCl3, CoBr3, and the like.

[0469] In the process (1), in order to promote the tandem hetero Friedel-Crafts reaction, a Brünster base or a Lewis acid may also be used. Among them, when using boron halides such as boron trifluoride, boron trichloride, boron tribromide, and boron triiodide, as the aromatic electrophilic substitution reaction proceeds, acids such as hydrogen fluoride, hydrogen chloride, hydrogen bromide, and hydrogen iodide are generated, so it is effective to use a Brünster base that captures the acid. On the other hand, when using boron amide halides and boron alkoxylates, as the aromatic electrophilic substitution reaction proceeds, amines and alcohols are generated, so in most cases, there is no need to use a Brünster base, but because the ability of amino or alkoxy groups to leave is low, it is effective to use a Lewis acid that promotes their departure.

[0470] The polycyclic aromatic compounds of the present invention also include compounds in which at least a portion of hydrogen atoms are substituted with deuterium or compounds in which a halogen such as fluorine or chlorine is substituted. Such compounds can be synthesized in the same manner as described above by using raw materials in which the desired positions are deuterated, fluorinated or chlorinated.

[0471] 2. Organic devices

[0472] 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, and organic thin-film solar cells. The polycyclic aromatic compound of the present invention is preferably used as a material for forming any one or more organic layers in an organic electroluminescent element.

[0473] 2-1. Organic electroluminescent element

[0474] 2-1-1. Structure of organic electroluminescent element

[0475] Figure 1 This is a schematic cross-sectional view showing an example of an organic EL element.

[0476] Figure 1 The organic EL element 100 shown includes: a substrate 101, an anode 102 arranged on the substrate 101, a hole injection layer 103 arranged on the anode 102, a hole transport layer 104 arranged on the hole injection layer 103, a light-emitting layer 105 arranged on the hole transport layer 104, an electron transport layer 106 arranged on the light-emitting layer 105, an electron injection layer 107 arranged on the electron transport layer 106, and a cathode 108 arranged on the electron injection layer 107.

[0477] In addition, the organic EL element 100 can also reverse the production order to form a structure such as the following, which includes: a substrate 101, a cathode 108 disposed on the substrate 101, an electron injection layer 107 disposed on the cathode 108, an electron transport layer 106 disposed on the electron injection layer 107, a light-emitting layer 105 disposed on the electron transport layer 106, a hole transport layer 104 disposed on the light-emitting layer 105, a hole injection layer 103 disposed on the hole transport layer 104, and an anode 102 disposed on the hole injection layer 103.

[0478] The above-mentioned layers are not all indispensable layers, and the minimum structural unit is set to a structure including an anode 102, a light-emitting layer 105, and a 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 set arbitrarily. In addition, the above-mentioned layers may each include a single layer or a plurality of layers.

[0479] The morphology of the layers constituting the organic EL element may be, in addition to the structural morphology of “substrate / anode / hole injection layer / hole transport layer / luminescent layer / electron transport layer / electron injection layer / cathode”, “substrate / anode / hole injection layer / luminescent layer / electron transport layer / electron injection layer / cathode”, “substrate / anode / hole injection layer / luminescent layer / electron transport layer / electron injection layer / cathode”, “substrate / anode / hole injection layer / hole transport layer / luminescent layer / electron injection layer / cathode”, “substrate / anode / hole injection layer / hole transport layer / luminescent layer / electron injection layer / cathode”, “substrate / anode / hole injection layer / hole transport layer / luminescent layer / electron injection layer / cathode”. The structural morphology of the 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 injection layer / cathode", "substrate / anode / hole injection 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", and "substrate / anode / light-emitting layer / electron injection layer / cathode".

[0480] The organic EL element may further have any one or both selected from an electron blocking layer (electron blocking layer) and a hole blocking layer (hole blocking layer). The electron blocking layer has a LUMO that is shallower than the light-emitting layer and a HOMO that is close to the light-emitting layer or the hole transport layer, and is arranged between the light-emitting layer and the hole transport layer. Since the electrons are retained in the light-emitting layer and do not leak out to the hole transport layer, the shortening of the life caused by the degradation of the hole transport layer and the reduction in efficiency caused by the reduction in recombination efficiency can be prevented. The hole blocking layer has a HOMO that is deeper than the light-emitting layer and a LUMO that is close to the light-emitting layer or the hole transport layer, and is arranged between the light-emitting layer and the electron transport layer. Since the holes are retained in the light-emitting layer and do not leak out to the electron transport layer, the shortening of the life caused by the degradation of the electron transport layer and the reduction in efficiency caused by the reduction in recombination efficiency can be prevented. The hole injection / transport layer may also serve as an electron blocking layer. The electron injection / transport layer may also serve as a hole blocking layer.

[0481] The organic EL element may further have a high T1 layer. The high T1 layer has a higher T1 than the main compound, auxiliary dopant compound or emission dopant compound used in the light-emitting layer, and is arranged between the light-emitting layer and the hole transport layer and / or between the light-emitting layer and the electron blocking layer. The value of T1 energy varies depending on the light-emitting mechanism of the element, but has a higher T1 than the compound used in the main body. By having a high T1 layer around the light-emitting layer, triplet energy can be enclosed, and the triplet energy that is usually unrelated to light emission in the fluorescent molecules can be converted into singlet energy, thereby obtaining high efficiency. The hole injection / transport layer or the electron blocking layer can also serve as the high T1 layer. The electron injection / transport layer or the hole blocking layer can also serve as the high T1 layer.

[0482] The polycyclic aromatic compound of the present invention is preferably used as a material for forming a light-emitting layer or a material for forming an electron transport layer, and is more preferably used as a material for forming a light-emitting layer.

[0483] 2-1-2. Substrate in organic electroluminescent element

[0484] The substrate 101 is a support of the organic EL element 100, and quartz, glass, metal, plastic, etc. can be generally used. The substrate 101 is formed into a plate, film or sheet according to the purpose, for example, a glass plate, a metal plate, a metal foil, a plastic film, a plastic sheet, etc. can be used. Among them, glass plates and transparent synthetic resin plates such as polyester, polymethacrylate, polycarbonate, polysulfone, etc. are preferably used. If it is a glass substrate, soda-lime glass or alkali-free glass, etc. can be used. In addition, the thickness can be sufficient to maintain the mechanical strength. In addition, in order to improve the gas barrier property, a gas barrier film such as a fine silicon oxide film can also be provided on at least one side of the substrate 101. When 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.

[0485] 2-1-3. Anode in organic electroluminescent element

[0486] The anode 102 plays a role of injecting holes into the light-emitting layer 105. When at least one of the hole injection layer 103 and the hole transport layer 104 is provided between the anode 102 and the light-emitting layer 105, holes are injected into the light-emitting layer 105 through these layers.

[0487] As materials for forming the anode 102, inorganic compounds and organic compounds can be cited. As inorganic compounds, for example, metals (aluminum, gold, silver, nickel, palladium, chromium, etc.), metal oxides (indium oxide, tin oxide, indium-tin oxide (Indium Tin Oxide, ITO), indium-zinc oxide (Indium Zinc Oxide, IZO), etc.), metal halides (copper iodide, etc.), copper sulfide, carbon black, ITO glass or Nesa glass, etc. As organic compounds, for example, polythiophenes such as poly(3-methylthiophene), conductive polymers such as polypyrrole and polyaniline, etc. can be cited. In addition, it can be appropriately selected from the substances used as the anode of the organic EL element for use.

[0488] 2-1-4. Hole injection layer and hole transport layer in organic electroluminescent element

[0489] The hole injection layer 103 plays a role of efficiently injecting holes migrated from the anode 102 into the light-emitting layer 105 or the hole transport layer 104. The hole transport layer 104 plays a role of efficiently transporting holes injected from the anode 102 or 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 stacking or mixing one or more hole injection / transport materials. In addition, an inorganic salt such as iron (III) chloride can be added to the hole injection / transport material to form a layer.

[0490] As a hole injection / transport material, it is necessary to efficiently inject / transmit holes from the positive electrode between electrodes to which an electric field is applied, and it is ideal that the hole injection efficiency is high and the injected holes are efficiently transmitted. Therefore, it is preferred that the material has a small ionization potential, a large hole mobility, and excellent stability, and is not prone to produce impurities that become traps during manufacture and use.

[0491] As materials for forming the hole injection layer 103 and the hole transport layer 104, any compound can be selected from compounds conventionally used as charge transport materials for holes in photoconductive materials, and known compounds used in hole injection layers and hole transport layers of p-type semiconductors and organic EL elements. Specific examples thereof include 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, N 4 ,N 4 '-Diphenyl-N 4 ,N 4 '-Bis(9-phenyl-9H-carbazole-3-yl)-[1,1'-biphenyl]-4,4'-diamine, N 4 ,N 4 ,N 4 ',N 4'-tetrakis[1,1'-biphenyl]-4-yl-[1,1'-biphenyl]-4,4'-diamine, 4,4',4"-tris(3-methylphenyl(phenyl)amino)triphenylamine and other triphenylamine derivatives, starburst amine derivatives, etc.), stilbene derivatives, phthalocyanine derivatives (metal-free, copper phthalocyanine, etc.), pyrazoline derivatives, hydrazone 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.), heterocyclic compounds such as porphyrin derivatives, polysilane, etc. Among polymer systems, polycarbonate or styrene derivatives, polyvinylcarbazole and polysilane having the above-mentioned monomers on the side chain are preferred, but there is no particular limitation as long as it is a compound that can form a thin film required for the production of a light-emitting element, can inject holes from the anode, and can further transport holes.

[0492] In addition, it is also known that the conductivity of organic semiconductors is strongly affected by their doping. Such organic semiconductor matrix materials contain compounds with good electron donating properties or compounds with good electron accepting properties. In order to dope electron donating materials, 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. Bayer, T. Fritz, K. Leo (M. Pfeiffer , A. Beyer, T. Fritz, K. Leo), "Applied Physics Letters (Appl. Phys. Lett.)", 73(22), 3202-3204 (1998)" and the reference "J. Blochwitz, M. Pfeiffer, T. Fritz, K. Leo (J. Blochwitz, M. Pfeiffer, T. Fritz, K. Leo), "Applied Physics Letters (Appl. Phys. Lett.)", 73(6), 729-731 (1998)"). These so-called holes are generated through the electron migration process of the electron-donating basic material (hole transport material). The conductivity of the basic material varies greatly depending on the number and mobility of the holes. As a host material having hole transport properties, for example, benzidine derivatives (N,N'-bis(3-methylphenyl)-N,N'-bis(phenyl)benzidine (N,N'-bis(3-methylphenyl)-N,N'-bis(phenyl)benzidine, TPD), starburst amine derivatives (4,4',4"-tris(N,N-diphenylamino)triphenylamine (4,4',4"-tris(N,N-diphenylamino)triphenylamine, TDATA), or specific metal phthalocyanines (especially zinc phthalocyanine (ZnPc), etc.) are known (Japanese Patent Publication No. 2005-167175).

[0493] The hole injection layer material and the hole transport layer material can also be used in the hole layer material as the following polymer compound or its polymer cross-linked product, or the following pendant polymer compound or its pendant polymer cross-linked product, wherein the polymer compound is obtained by polymerizing a reactive compound substituted with a reactive substituent in the hole injection layer material and the hole transport layer material as a monomer, and the pendant polymer compound is obtained by reacting a main chain polymer with the reactive compound.

[0494] 2-1-5. Light-emitting layer in organic electroluminescent element

[0495] The light-emitting layer 105 is a layer that emits light by allowing holes injected from the anode 102 to recombine with electrons injected from the cathode 108 between electrodes to which an electric field is applied. The material forming the light-emitting layer 105 can be any compound (luminescent compound) that emits light by being excited by the recombination of holes and electrons, and preferably a compound that can form a stable thin film shape and exhibits strong luminescence (fluorescence) efficiency in a solid state.

[0496] The light-emitting layer may be a single layer or may include multiple layers, either of which are acceptable and are each formed of a light-emitting layer material. When the light-emitting layer includes multiple layers, preferably any one layer includes the polycyclic aromatic compound of the present invention. The light-emitting layer is preferably a single layer.

[0497] The light-emitting layer is formed by materials for the light-emitting layer (main material, dopant material). The main material and the dopant material may be one kind or a combination of multiple kinds, either of which is acceptable. For example, as dopant materials, emitting dopants and auxiliary dopants can be used. In addition, the light-emitting layer is also preferably composed of an emitting dopant and at least two selected from the group consisting of a hole-transporting main material, an electron-transporting main material and an auxiliary dopant material. The dopant material may be contained in the main material as a whole or in part of the main material, either of which is acceptable. As a doping method, it can be formed by co-evaporation with the main material, or it can be pre-mixed with the main material and evaporated simultaneously. 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 a material in an organic solvent.

[0498] The amount of the host material used varies depending on the type of the host material, and can be determined by matching the characteristics of the host material. The basis for the amount of the host material used is preferably 50% to 99.999% by mass of the total mass of the material for the light-emitting layer, more preferably 80% to 99.95% by mass, and further preferably 90% to 99.9% by mass. In the case where the host material is a combination of a hole-transporting host material and an electron-transporting host material, the amount of the host material used is the mass of the hole-transporting host material and the electron-transporting host material added together. The ratio of the amount of the hole-transporting host material to the electron-transporting host material used can be 1:9 to 9:1 in terms of mass ratio, preferably 4:6 to 6:4, and more preferably approximately 1:1.

[0499] The amount of the emission dopant material used varies depending on the type of the emission dopant, and can be determined by matching its characteristics. The basis for the amount of the emission dopant material used is preferably 0.001% to 50% by mass of the total mass of the light-emitting layer material, more preferably 0.05% to 20% by mass, and further preferably 0.1% to 10% by mass. If it is within the above range, it is preferred, for example, in terms of preventing concentration quenching.

[0500] In an organic electroluminescent element that uses an auxiliary dopant (thermally active delayed phosphor or phosphorescent material) in addition to an emitting dopant, it is preferred that the emitting dopant material be used in a low concentration in order to prevent concentration quenching. In terms of the efficiency of energy migration, it is preferred that the auxiliary dopant material be used in a high concentration. In terms of the efficiency of the thermally active delayed fluorescence mechanism, it is preferred that the auxiliary dopant material be used in a high concentration. In an organic electroluminescent element that uses a thermally active delayed phosphor as an auxiliary dopant, it is preferred that the emitting dopant material be used in a low concentration compared to the amount of the auxiliary dopant material in terms of the efficiency of the thermally active delayed fluorescence mechanism of the auxiliary dopant.

[0501] When using auxiliary dopant materials, the base usage amounts of the main material, auxiliary dopant material and emission dopant material are 40% to 99% by mass, 59% to 1% by mass and 20% to 0.001% by mass, respectively, relative to the total mass of the materials for the light-emitting layer, preferably 60% to 95% by mass, 39% to 5% by mass and 10% to 0.01% by mass, respectively, and more preferably 70% to 90% by mass, 29% to 10% by mass and 5% to 0.05% by mass, respectively.

[0502] The polycyclic aromatic compound containing the structural unit represented by formula (1) is preferably used as a material for forming the light-emitting layer, more preferably used as a dopant, and particularly preferably used as an emissive dopant.

[0503] The polycyclic aromatic compound including the structural unit represented by the formula (1) can be used as an emitting dopant for a TTF device utilizing a phenomenon in which a singlet exciton is generated from a plurality of triplet excitons (Triplet-Triplet Fusion (TTF)).

[0504] In addition, a polycyclic aromatic compound containing a structural unit represented by formula (1) can be used as an emitting dopant of a TADF element as a "thermally active delayed phosphor". In a "thermally active delayed phosphor", by reducing the energy difference between the lowest excited singlet state and the lowest excited triplet state, an inverse intersystem crossing from the lowest excited triplet state to the lowest excited singlet state, which usually has a low transition probability, is efficiently generated, thereby showing luminescence from the singlet state (thermally active delayed fluorescence, TADF). In normal fluorescent luminescence, 75% of the triplet excitons generated by current excitation pass through the thermal deactivation path and therefore cannot be extracted as fluorescence. On the other hand, in TADF, all excitons can be used for fluorescent luminescence, which can achieve a highly efficient organic EL element.

[0505] It is generally believed that the case of fast delayed fluorescence has excellent TADF properties. Specifically, when a light-emitting material with a delayed fluorescence lifetime of 100 μsec or less is used as an emission dopant in a light-emitting element, high element efficiency and long element lifetime can be provided. The delayed fluorescence lifetime is preferably 20 μsec or less, more preferably less than 20 μsec, further preferably 10 μsec or less, and most preferably 5 μsec or less.

[0506] In addition, generally speaking, ΔE S1T1 The smaller the value of, the better the TADF property. S1T1 is the lowest excited singlet energy level (E S1 ) and the lowest excited triplet energy level (E T1 ) energy difference. Specifically, ΔE S1T1 The value of is preferably 0.20 eV or less, more preferably 0.15 eV or less, and particularly preferably 0.10 eV or less.

[0507] <Main material>

[0508] Examples of the host material include condensed ring derivatives of anthracene or pyrene, which have been known as luminescent materials in the past, bistyryl derivatives such as bistyryl anthracene derivatives and distyryl benzene derivatives, tetraphenylbutadiene derivatives, cyclopentadiene derivatives, fluorene derivatives, benzofluorene derivatives, N-phenylcarbazole derivatives, carbazole nitrile derivatives, dibenzo[pi] Derivatives, etc. In addition, from the viewpoint of durability, it is also preferred that part or all of the hydrogen atoms of the host material are deuterated. Furthermore, it is also preferred that a host compound in which part or all of the hydrogen atoms are deuterated is combined with a dopant compound in which part or all of the hydrogen atoms are deuterated to form a light-emitting layer.

[0509] The host material may be one kind or a combination of two or more kinds. In the case of a combination of two or more kinds, a combination of a hole-transporting host material and an electron-transporting host material is preferred.

[0510] [Anthracene compounds]

[0511] Examples of the main anthracene compound include compounds represented by formula (3-H) and compounds represented by formula (3-H2).

[0512] [Chemistry 76]

[0513]

[0514] In formula (3-H),

[0515] X and Ar 4 are each independently hydrogen or selected from substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted diarylamino, optionally substituted diheteroarylamino, substituted or unsubstituted arylheteroarylamino, substituted or unsubstituted alkyl, optionally substituted cycloalkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkoxy, substituted or unsubstituted aryloxy, substituted or unsubstituted arylthio or substituted silyl, all of X and Ar 4 It will not become hydrogen at the same time.

[0516] At least one hydrogen in the compound represented by formula (3-H) may be substituted with a halogen, a cyano group, a deuterium group or an optionally substituted heteroaryl group.

[0517] In addition, the structure represented by formula (3-H) can also be used as a unit structure to form a polymer (preferably a dimer). In the above case, for example, the unit structures represented by formula (3-H) are bonded to each other via X, and as the X, a single bond, an arylene group (phenylene, biphenylene and naphthylene, etc.) and a heteroarylene group (pyridine ring, dibenzofuran ring, dibenzothiophene ring, carbazole ring, benzocarbazole ring and phenyl-substituted carbazole ring, etc., having a divalent bonding valence) can be listed.

[0518] The details of each group in the compound represented by formula (3-H) can be referred to the description of formula (1) above, and will be further described in the following preferred embodiment.

[0519] Preferred embodiments of the anthracene compound are described below. The definitions of the symbols in the following structures are the same as those described above.

[0520] [Chemistry 77]

[0521]

[0522] In formula (3-H), X is independently a group represented by formula (3-X1), formula (3-X2) or formula (3-X3), and the group represented by formula (3-X1), formula (3-X2) or formula (3-X3) is bonded to the anthracene ring of formula (3-H) at *. Preferably, two Xs are not simultaneously represented by formula (3-X3). More preferably, two Xs are not simultaneously represented by formula (3-X2).

[0523] In addition, the structure represented by formula (3-H) can also be used as a unit structure to form a polymer (preferably a dimer). In the above case, for example, the unit structures represented by formula (3-H) are bonded to each other via X, and as the X, a single bond, an arylene group (phenylene, biphenylene and naphthylene, etc.) and a heteroarylene group (pyridine ring, dibenzofuran ring, dibenzothiophene ring, carbazole ring, benzocarbazole ring and phenyl-substituted carbazole ring, etc., having a divalent bonding valence) can be listed.

[0524] The naphthylene moiety in formula (3-X1) and formula (3-X2) can be condensed with one benzene ring. The structure formed by condensation in this manner is shown below.

[0525] [Chemistry 78]

[0526]

[0527] Ar 1 and Ar 2 are independently hydrogen, phenyl, biphenyl, terphenyl, quaterphenyl, naphthyl, phenanthryl, fluorenyl, benzofluorenyl, phenyl, triphenylene, pyrene, or a group represented by formula (A) (including carbazolyl, benzocarbazolyl, and phenyl-substituted carbazolyl). 1 or Ar 2 In the case of a group represented by formula (A), the group represented by formula (A) is bonded to the naphthalene ring in formula (3-X1) or formula (3-X2) at the *.

[0528] Ar 3 is phenyl, biphenyl, terphenyl, quaterphenyl, naphthyl, phenanthryl, fluorenyl, benzofluorenyl, phenyl, triphenylene, pyrene, or a group represented by formula (A) (including carbazolyl, benzocarbazolyl, and phenyl-substituted carbazolyl). 3 In the case of a group represented by formula (A), the group represented by formula (A) is bonded to the single bond represented by the straight line in formula (3-X3) at the *. That is, the anthracene ring of formula (3-H) is directly bonded to the group represented by formula (A).

[0529] In addition, Ar 3 It may have a substituent, Ar 3At least one hydrogen in the alkyl group may be replaced by an alkyl group having 1 to 4 carbon atoms, a cycloalkyl group having 5 to 10 carbon atoms, a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a phenanthrenyl group, a fluorenyl group, substituted with a phenyl group, a triphenylene group, a pyrene group, or a group represented by formula (A) (including a carbazolyl group and a phenyl-substituted carbazolyl group). 3 When the substituent is a group represented by formula (A), the group represented by formula (A) is in the position * and Ar in formula (3-X3) 3 Bond.

[0530] Ar 4 Each independently represents hydrogen, phenyl, biphenyl, terphenyl, naphthyl, or a silyl group substituted with an alkyl group having 1 to 4 carbon atoms (such as methyl, ethyl, and tert-butyl) and / or a cycloalkyl group having 5 to 10 carbon atoms.

[0531] Examples of the alkyl group having 1 to 4 carbon atoms which substitutes in the silyl group include methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, tert-butyl, and cyclobutyl. Three hydrogen atoms in the silyl group are independently substituted by these alkyl groups.

[0532] Specific examples of the “silyl group substituted with an alkyl group having 1 to 4 carbon atoms” include trimethylsilyl, triethylsilyl, tripropylsilyl, triisopropylsilyl, tributylsilyl, tri-sec-butylsilyl, tri-tert-butylsilyl, ethyldimethylsilyl, propyldimethylsilyl, isopropyldimethylsilyl, butyldimethylsilyl, sec-butyldimethylsilyl, tert-butyldimethylsilyl, methyldiethylsilyl, propyldiethylsilyl, isopropyldiethylsilyl, butyldiethylsilyl, sec-butyldiethylsilyl, tert-butyldiethylsilyl, methyldipropylsilyl, ethyldipropylsilyl, butyldipropylsilyl, sec-butyldipropylsilyl, tert-butyldipropylsilyl, methyldiisopropylsilyl, ethyldiisopropylsilyl, butyldiisopropylsilyl, sec-butyldiisopropylsilyl, and tert-butyldiisopropylsilyl.

[0533] Examples of the cycloalkyl group having 5 to 10 carbon atoms which substitutes in the silyl group 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 (norbornyl), bicyclo[2.2.2]octyl, adamantyl, decahydronaphthyl, decahydroazulenyl, and the like, and the three hydrogen atoms in the silyl group are independently substituted by these cycloalkyl groups.

[0534] Specific examples of the "silyl group substituted with a cycloalkyl group having 5 to 10 carbon atoms" include a tricyclopentylsilyl group and a tricyclohexylsilyl group.

[0535] The substituted silyl group includes a dialkylcycloalkylsilyl group substituted with two alkyl groups and one cycloalkyl group, and an alkyldicycloalkylsilyl group substituted with one alkyl group and two cycloalkyl groups. Specific examples of the substituted alkyl group and cycloalkyl group include the groups described above.

[0536] In addition, the hydrogen in the chemical structure of the anthracene compound represented by formula (3-H) may also be replaced by a group represented by formula (A). In the case of replacement by a group represented by formula (A), the group represented by formula (A) replaces at least one hydrogen in the compound represented by formula (3-H) at the *.

[0537] The group represented by formula (A) is one of substituents that the anthracene compound represented by formula (3-H) may have.

[0538] [Chemistry 79]

[0539]

[0540] In formula (A), Y is -O-, -S- or >NR 29 , R 21 ~R 28 are each independently hydrogen, an optionally substituted alkyl group, an optionally substituted cycloalkyl group, an optionally substituted aryl group, an optionally substituted heteroaryl group, an optionally substituted alkoxy group, an optionally substituted aryloxy group, an optionally substituted arylthio group, a trialkylsilyl group, a tricycloalkylsilyl group, a dialkylcycloalkylsilyl group, an alkyldicycloalkylsilyl group, an optionally substituted amino group, a halogen group, a hydroxyl group or a cyano group, and R 21 ~R 28 The adjacent groups in the group may be bonded to each other to form a hydrocarbon ring, an aromatic ring or a heteroaromatic ring. 29 is hydrogen or an aryl group which may be substituted.

[0541] Y in formula (A) is preferably -O-.

[0542] R 21 ~R 28 The adjacent groups in can be bonded to each other to form a hydrocarbon ring, an aryl ring or a heteroaryl ring. The case where a ring is not formed is a group represented by the following formula (A-1). As the case where a ring is formed, for example, the groups represented by the following formulas (A-2) to (A-14) can be listed. In addition, at least one hydrogen in the group represented by any one of formulas (A-1) to (A-14) can be substituted by an alkyl, cycloalkyl, aryl, heteroaryl, alkoxy, aryloxy, arylthio, trialkylsilyl, tricycloalkylsilyl, dialkylcycloalkylsilyl, alkyldicycloalkylsilyl, diaryl (two aryl groups can be bonded to each other via a linking group) substituted amino, diheteroaryl substituted amino, arylheteroaryl substituted amino, halogen, hydroxyl or cyano.

[0543] [Chemistry 80]

[0544]

[0545] Examples of the ring formed by mutually bonding adjacent groups include a hydrocarbon ring such as a cyclohexane ring, and examples of the aryl ring or heteroaryl ring include the above R 21 ~R 28 The ring structure described in the "aryl" or "heteroaryl" in formula (A-1) is formed by condensing with one or two benzene rings.

[0546] The group represented by formula (A) is a group obtained by removing a hydrogen atom at any position of formula (A), and * represents the position. That is, the group represented by formula (A) can be bonded at any position. For example, it can be bonded to any carbon atom on the two benzene rings in the structure of formula (A), R 21 ~R 28 The atoms on any ring formed by bonding the adjacent groups in the formula (A) to each other, or the ">NR" as Y in the structure of the formula (A) 29 "R 29 Any position in or ">NR 29 "N(R 29 The same applies to the group represented by any one of the formulae (A-1) to (A-14).

[0547] As the group represented by formula (A), for example, a group represented by any one of formulas (A-1) to (A-14) can be listed, preferably a group represented by any one of formulas (A-1) to (A-5) and (A-12) to (A-14), more preferably a group represented by any one of formulas (A-1) to (A-4), further preferably a group represented by any one of formulas (A-1), (A-3) and (A-4), and particularly preferably a group represented by formula (A-1).

[0548] Examples of the group represented by formula (A) include the following groups: Y and * in the formula have the same meanings as described above.

[0549] [Chemistry 81]

[0550]

[0551] [Chemistry 82]

[0552]

[0553] In the compound represented by formula (3-H), the group represented by formula (A) is preferably in a naphthalene ring in formula (3-X1) or formula (3-X2), a single bond in formula (3-X3) and Ar in formula (3-X3).3 The form of any bond in .

[0554] In addition, all or part of the hydrogen atoms in the chemical structure of the anthracene compound represented by the formula (3-H) may be deuterium atoms.

[0555] The anthracene compound serving as a host may be, for example, a compound represented by the following formula (3-H2).

[0556] [Chemistry 83]

[0557]

[0558] In formula (3-H2), Ar c is an aryl group which may be substituted or a heteroaryl group which may be substituted, R c is hydrogen, alkyl, or cycloalkyl, Ar 11 ,Ar 12 ,Ar 13 ,Ar 14 ,Ar 15 , A 16 ,Ar 17 and Ar 18 Each of the above groups is independently hydrogen, a substitutable aryl, a substitutable heteroaryl, a substitutable diarylamino, a substitutable diheteroarylamino, a substitutable arylheteroarylamino, a substitutable alkyl, a substitutable cycloalkyl, a substitutable alkenyl, a substitutable alkoxy, a substitutable aryloxy, a substitutable arylthio, or a substitutable silanyl group, and at least one hydrogen in the compound represented by formula (3-H2) may be substituted by halogen, cyano, or deuterium.

[0559] The definitions of “substitutable aryl”, “substitutable heteroaryl”, “substitutable diarylamino”, “substitutable diheteroarylamino”, “substitutable arylheteroarylamino”, “substitutable alkyl”, “substitutable cycloalkyl”, “substitutable alkenyl”, “substitutable alkoxy”, “substitutable aryloxy”, “substitutable arylthio”, or “substitutable silyl” in formula (3-H2) are the same as those shown in formula (3-H), and the description in formula (3-H) can be cited.

[0560] The "aryl group which may be substituted" is preferably a group represented by any one of the following formulas (3-H2-X1) to (3-H2-X8).

[0561] [Chemistry 84]

[0562]

[0563] In formula (3-H2-X1) to formula (3-H2-X8), * represents a bonding position. In formula (3-H2-X1) to formula (3-H2-X3), Ar 21 ,Ar 22 and Ar 23 are independently hydrogen, phenyl, biphenyl, terphenyl, quaterphenyl, naphthyl, phenanthryl, fluorenyl, benzofluorenyl, In the description of formula (3-H2), the group represented by formula (A) is the same as the group described in the anthracene compound represented by formula (3-H).

[0564] In formula (3-H2-X4) to formula (3-H2-X8), Ar 24 ,Ar 25 ,Ar 26 ,Ar 27 ,Ar 28 ,Ar 29 , and Ar 30 are independently hydrogen, phenyl, biphenyl, terphenyl, naphthyl, phenanthryl, fluorenyl, In addition, any one or two or more hydrogen atoms in each of the groups represented by formula (3-H2-X1) to formula (3-H2-X8) may be substituted by an alkyl group having 1 to 6 carbon atoms (preferably a methyl group or a tert-butyl group).

[0565] Furthermore, preferred examples of the "aryl group which may be substituted" include phenyl, biphenyl, terphenyl, naphthyl, phenanthrenyl, fluorenyl, A terphenyl group (particularly m-terphenyl-5′-group) substituted with one or more substituents selected from the group consisting of a terphenyl group, a triphenylene group, a pyrene group, and a group represented by formula (A).

[0566] Examples of the "optionally substituted heteroaryl group" include groups represented by formula (A). In addition, specific examples of the "optionally substituted aryl group" and the "optionally substituted heteroaryl group" include dibenzofuranyl, naphthobenzofuranyl, and phenyl-substituted dibenzofuranyl.

[0567] At least one hydrogen in the compound represented by formula (3-H2) may be substituted by halogen, cyano or deuterium. Examples of the "halogen" in the above case include fluorine, chlorine, bromine, and iodine. Particularly preferred are compounds in which all hydrogens in the compound represented by formula (3-H2) are substituted by deuterium.

[0568] In formula (3-H2), R c It is hydrogen, alkyl or cycloalkyl, preferably hydrogen, methyl or tert-butyl, more preferably hydrogen.

[0569] In the formula (3-H2), Ar is preferably 11 ~Ar 18 At least two of them are substituted aryl groups or substituted heteroaryl groups. That is, the anthracene compound represented by formula (3-H2) preferably has a structure in which at least three substituents selected from the group consisting of substituted aryl groups and substituted heteroaryl groups are bonded to the anthracene ring.

[0570] Among the anthracene compounds represented by formula (3-H2), Ar 11 ~Ar 18 Two of the anthracene compounds are substituted aryl groups or substituted heteroaryl groups, and the other six are hydrogen, substituted alkyl groups, substituted cycloalkyl groups, substituted alkenyl groups or substituted alkoxy groups. That is, the anthracene compound represented by formula (3-H2) is more preferably a structure having three substituents selected from the group consisting of substituted aryl groups and substituted heteroaryl groups bonded to the anthracene ring.

[0571] Among the anthracene compounds represented by formula (3-H2), Ar 11 ~Ar 18 Any two of them are aryl or heteroaryl, and the other six are hydrogen, methyl or tert-butyl.

[0572] Furthermore, in the formula (3-H2), R c is hydrogen, and Ar 11 ~Ar 18 Any six of them are hydrogen.

[0573] The anthracene compound represented by formula (3-H2) is preferably an anthracene compound represented by the following formula (3-H2-A), formula (3-H2-B), formula (3-H2-C), formula (3-H2-D), or formula (3-H2-E).

[0574] [Chemistry 85]

[0575]

[0576] In formula (3-H2-A), formula (3-H2-B), formula (3-H2-C), formula (3-H2-D) or formula (3-H2-E), Ar c '、Ar 11 '、Ar 12 '、Ar 13 '、Ar 14 '、Ar 15 '、Ar 17 ' and Ar 18 'are independently phenyl, biphenyl, terphenyl, quaterphenyl, naphthyl, phenanthryl, fluorenyl, benzofluorenyl, phenyl, triphenylene, pyrenyl, or a group represented by formula (A), at least one hydrogen in these groups may be replaced by phenyl, biphenyl, terphenyl, quaterphenyl, naphthyl, phenanthryl, fluorenyl, benzofluorenyl, Here, when the hydrogen atoms of the methylene groups in the fluorenyl group and the benzofluorenyl group are substituted by phenyl groups, these phenyl groups may be bonded to each other via single bonds. c '、Ar 11 '、Ar 12 '、Ar 13 '、Ar 14 '、Ar 15 '、Ar 17 ' and Ar 18 The carbon atom of the anthracene ring of ' may be bonded with a methyl group or a tert-butyl group in place of hydrogen.

[0577] When Ar c '、Ar 11 '、Ar 12 '、Ar 13 '、Ar 14 '、Ar 15 '、Ar 17 ' and Ar 18 When ' is a substituted or unsubstituted phenyl group or a substituted or unsubstituted naphthyl group, it is preferably a group represented by any one of the formulas (3-H2-X1) to (3-H2-X8).

[0578] Ar c '、Ar 11 '、Ar 12 '、Ar 13 '、Ar 14 '、Ar 15 '、Ar 17 ' and Ar 18 'More preferably, they are independently phenyl, biphenyl (especially biphenyl-2-yl or biphenyl-4-yl), terphenyl (especially m-terphenyl-5'-yl), naphthyl, phenanthrenyl, fluorenyl, or a group represented by any one of the formulas (A-1) to (A-4). In this case, at least one hydrogen in these groups may be substituted by a phenyl, biphenyl, naphthyl, phenanthrenyl, fluorenyl, or a group represented by any one of the formulas (A-1) to (A-4).

[0579] In addition, at least one hydrogen in the compound represented by Formula (3-H2-A), Formula (3-H2-B), Formula (3-H2-C), Formula (3-H2-D) or Formula (3-H2-E) may be substituted by halogen, cyano, or deuterium. In addition, a deuterated form is preferred, and a form in which all anthracene rings are deuterated, or a form in which all hydrogen atoms are deuterated is preferred.

[0580] Particularly preferred anthracene compounds represented by formula (3-H2) include anthracene compounds represented by the following formula (3-H2-Aa).

[0581] [Chemistry 86]

[0582]

[0583] In the formula (3-H2-Aa), Ar c '、Ar 14 ' and Ar 15 'are independently phenyl, biphenyl, terphenyl, naphthyl, phenanthryl, fluorenyl, benzofluorenyl, A group represented by any one of the formulae (A-1) to (A-11), wherein at least one hydrogen in these groups may be replaced by a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a phenanthryl group, a fluorenyl group, a benzofluorenyl group, Here, when the hydrogen atoms of the methylene groups in the fluorenyl group and the benzofluorenyl group are substituted by phenyl groups, these phenyl groups may be bonded to each other via single bonds. c '、Ar 14 ' and Ar 15 The carbon atom of the anthracene ring of ' may be substituted with a methyl group or a tert-butyl group instead of hydrogen. At least one hydrogen in the compound represented by formula (3-H2-Aa) may be substituted with a halogen or a cyano group, and at least one hydrogen in the compound represented by formula (3-H2-Aa) may be substituted with deuterium.

[0584] In the formula (3-H2-Aa), Ar c '、Ar 14 ' and Ar 15 'Preferably, they are independently phenyl, biphenyl, terphenyl, naphthyl, phenanthryl, fluorenyl, or a group represented by any one of the formulas (A-1) to (A-4), and at least one hydrogen in these groups may be substituted by a phenyl, naphthyl, phenanthryl, fluorenyl, or a group represented by any one of the formulas (A-1) to (A-4).

[0585] In the compound represented by the formula (3-H2-Aa), it is preferred that the carbon atom bonded to at least the 10-position of the anthracene ring (Ar c The hydrogen at the carbon to which the bond is attached is substituted with deuterium. That is, the compound represented by the formula (3-H2-Aa) is preferably a compound represented by the following formula (3-H2-Ab). In the formula (3-H2-Ab), D is deuterium, Ar c '、Ar 14 ' and Ar 15' is the same as the definition in formula (3-H2-Aa). D in formula (3-H2-Ab) means that at least the position is deuterated, and any one or more other hydrogens in formula (3-H2-Ab) may be deuterated at the same time, and it is also preferred that all hydrogens in formula (3-H2-Ab) are deuterated.

[0586] [Chemistry 87]

[0587]

[0588] Specific examples of anthracene compounds include compounds represented by formula (3-131-Y) to (3-182-Y), formula (3-183-N), formula (3-184-Y) to (3-284-Y), and compounds represented by formula (3-500) to (3-557), and formula (3-600) to (3-605), and formula (3-606-Y) to (3-626-Y). The hydrogen atoms in these formulas may be partially or completely substituted with deuterium, but particularly preferred forms of deuterium substitution are listed separately. Y in the formula may be -O-, -S-, >NR 29 (R 29 The definition is the same as above) or>C(-R 30 )2(R 30 is any one of an aryl group or an alkyl group that can be linked, R 29 For example, phenyl, R 30 For example, methyl group. Regarding the formula number, for example, when Y is O, the formula (3-131-Y) is the formula (3-131-O), and when Y is -S- or >NR 29 In the case of, set it to formula (3-131-S) or formula (3-131-N) respectively.

[0589] [Chemistry 88]

[0590]

[0591] [Chemistry 89]

[0592]

[0593] [Chemistry 90]

[0594]

[0595] [Chemistry 91]

[0596]

[0597] [Chemistry 92]

[0598]

[0599] [Chemistry 93]

[0600]

[0601] [Chemistry 94]

[0602]

[0603] [Chemistry 95]

[0604]

[0605] [Chemistry 96]

[0606]

[0607] [Chemistry 97]

[0608]

[0609] [Chemistry 98]

[0610]

[0611] [Chemistry 99]

[0612]

[0613] [Chemical 100]

[0614]

[0615] [Chemistry 101]

[0616]

[0617] [Chemistry 102]

[0618]

[0619] [Chemistry 103]

[0620]

[0621] [Chemistry 104]

[0622]

[0623] [Chemistry 105]

[0624]

[0625] [Chemistry 106]

[0626]

[0627] [Chemistry 107]

[0628]

[0629] In the above formula, D is deuterium.

[0630] Among these compounds, preferred are compounds of formula (3-131-Y) to (3-134-Y), formula (3-138-Y), formula (3-140-Y) to (3-143-Y), formula (3-150-Y), formula (3-153-Y) to (3-156-Y), formula (3-166-Y), formula (3-168-Y), formula (3-173-Y), formula (3-177-Y), formula (3-180-Y) to (3-183-N), formula (3-185-Y), formula (3-190-Y), formula (3-223-Y), formula (3-224-Y), -241-Y), formula (3-250-Y), formula (3-252-Y) to formula (3-254-Y), formula (3-270-Y) to formula (3-284-Y), formula (3-501), formula (3-507), formula (3-508), formula (3-509), formula (3-513), formula (3-514), formula (3-519), formula (3-521), formula (3-538) to formula (3-547) or formula (3-600) to formula (3-605), and formula (3-606-Y) to formula (3-626-Y). In addition, Y is preferably -O- or >NR 29 , more preferably -O-. In addition, a deuterium-substituted form is also preferred.

[0631] The anthracene compound may be a compound having a reactive group at a desired position of the anthracene skeleton, and in the case of an anthracene compound represented by formula (3-H), a compound having a reactive group at a desired position of the anthracene skeleton, 4 and a compound having a reactive group in a partial structure such as the structure of formula (A) as a starting material, and applying Suzuki coupling, Negishi coupling, or other known coupling reactions to manufacture. As the reactive group of the reactive compound, halogen or boric acid can be cited. As a specific manufacturing method, for example, reference can be made to the synthesis method of paragraphs

[0089] to

[0175] of International Publication No. 2014 / 141725.

[0632] [Fluorene compounds]

[0633] The compound represented by formula (4-H) basically functions as a main body.

[0634] [Chemistry 108]

[0635]

[0636] In formula (4-H),

[0637] R1 To R 10 are independently hydrogen, aryl, heteroaryl (the heteroaryl may be bonded to the fluorene skeleton in formula (4-H) via a single bond or a linking group), diarylamino, diheteroarylamino, arylheteroarylamino, alkyl, cycloalkyl, alkenyl, alkoxy or aryloxy, at least one hydrogen in these groups may be substituted by an aryl, heteroaryl, alkyl or cycloalkyl group, and R 1 With R 2 , R 2 With R 3 , R 3 With R 4 , R 5 With R 6 , R 6 With R 7 , R 7 With R 8 or R 9 With R 10 They may be independently bonded to form a condensed ring or a spiro ring, at least one hydrogen in the formed ring may be substituted by an aryl group, a heteroaryl group (the heteroaryl group may be bonded to the formed ring via a single bond or a linking group), a diarylamino group, a diheteroarylamino group, an arylheteroarylamino group, an alkyl group, a cycloalkyl group, an alkenyl group, an alkoxy group or an aryloxy group, at least one hydrogen in these may be substituted by an aryl group, a heteroaryl group, an alkyl group or a cycloalkyl group, and at least one hydrogen in the compound represented by formula (4-H) may be substituted by a halogen, a cyano group or a deuterium.

[0638] The details of each group in the definition of formula (4-H) can be referred to the description of the above-mentioned formula (1).

[0639] As R 1 To R 10 The alkenyl group in the alkylene group may be, for example, an alkenyl group having 2 to 30 carbon atoms, preferably an alkenyl group having 2 to 20 carbon atoms, more preferably an alkenyl group having 2 to 10 carbon atoms, further preferably an alkenyl group having 2 to 6 carbon atoms, and particularly preferably an alkenyl group having 2 to 4 carbon atoms. Preferred alkenyl groups are vinyl, 1-propenyl, 2-propenyl, 1-butenyl, 2-butenyl, 3-butenyl, 1-pentenyl, 2-pentenyl, 3-pentenyl, 4-pentenyl, 1-hexenyl, 2-hexenyl, 3-hexenyl, 4-hexenyl, or 5-hexenyl.

[0640] In addition, specific examples of heteroaryl groups include monovalent groups represented by removing any one hydrogen atom from the compounds of the following formula (4-Ar1), (4-Ar2), (4-Ar3), (4-Ar4) or (4-Ar5).

[0641] [Chemistry 109]

[0642]

[0643] In Formula (4-Ar1) to Formula (4-Ar5), Y 1 are independently O, S or NR, R is phenyl, biphenyl, naphthyl, anthracenyl or hydrogen, and at least one hydrogen in the structures of Formula (4-Ar1) to (4-Ar5) may be substituted by phenyl, biphenyl, naphthyl, anthracenyl, phenanthryl, methyl, ethyl, propyl, or butyl.

[0644] These heteroaryl groups may be bonded to the fluorene skeleton in formula (4-H) via a single bond or a linking group. That is, the fluorene skeleton in formula (4-H) may not only be directly bonded to the heteroaryl group, but may also be bonded between them via a linking group. Examples of the linking group include phenylene, biphenylene, naphthylene, anthracene, methylene, ethylene, -OCH2CH2-, -CH2CH2O-, or -OCH2CH2O-.

[0645] In addition, R in formula (4-H) 1 With R 2 , R 2 With R 3 , R 3 With R 4 , R 5 With R 6 , R 6 With R 7 or R 7 With R 8 can independently bond and form a condensed ring, R 9 With R 10 Can bond and form a spiro ring. 1 To R 8 The condensed ring formed is a ring condensed on the benzene ring in formula (4-H), and is an aliphatic ring or an aromatic ring. An aromatic ring is preferred, and examples of the structure containing the benzene ring in formula (4-H) include a naphthalene ring and a phenanthrene ring. 9 With R 10 The spiro ring formed is a ring spiro-bonded to the 5-membered ring in formula (4-H), and is an aliphatic ring or an aromatic ring. An aromatic ring is preferred, and examples thereof include a fluorene ring.

[0646] The compound represented by formula (4-H) is preferably a compound represented by the following formula (4-H-1), formula (4-H-2) or formula (4-H-3), and R in formula (4-H) is 1 With R 2 The compound formed by condensation of the benzene ring formed by bonding, R in formula (4-H) 3 With R 4 The compound formed by condensation of the benzene ring formed by bonding, in formula (4-H) R 1 To R 8A compound in which neither of is bonded.

[0647] [Chemistry 110]

[0648]

[0649] R in formula (4-H-1), formula (4-H-2) and formula (4-H-3) 1 To R 10 The definition of is the same as that of R in formula (4-H) 1 To R 10 The same, R in formula (4-H-1) and formula (4-H-2) 11 To R 14 The definition of is also the same as R in formula (4) 1 To R 10 same.

[0650] The compound represented by formula (4-H) is preferably a compound represented by the following formula (4-H-1A), formula (4-H-2A) or formula (4-H-3A), and R in formula (4-H-1), formula (4-H-2) or formula (4-H-3) is 9 With R 10 A compound that is bonded to form a spiro-fluorene ring.

[0651] [Chemistry 111]

[0652]

[0653] R in formula (4-H-1A), formula (4-H-2A) and formula (4-H-3A) 2 To R 7 The definition is the same as that of R in formula (4-H-1), formula (4-H-2) and formula (4-H-3) 2 To R 7 The same, and R in formula (4-H-1A) and formula (4-H-2A) 11 To R 14 The definition of is also the same as R in formula (4-H-1) and formula (4-H-2) 11 To R 14 same.

[0654] In addition, all or part of hydrogen in the compound represented by formula (4-H) may be substituted by halogen, cyano or deuterium.

[0655] More specific examples of the main fluorene compound include compounds represented by the following structural formulas.

[0656] [Chemistry 112]

[0657]

[0658] [Dibenzo Compound]

[0659] As the main The compound is, for example, a compound represented by the following formula (5-H).

[0660] [Chemistry 113]

[0661]

[0662] In formula (5-H), R 1 To R 16 are independently hydrogen, aryl, heteroaryl (the heteroaryl may be connected to the dibenzoylmethane in formula (5-H) via a single bond or a linking group skeleton bond), diarylamino, diheteroarylamino, arylheteroarylamino, alkyl, cycloalkyl, alkenyl, alkoxy or aryloxy, at least one hydrogen in these groups may be substituted by an aryl, heteroaryl, alkyl or cycloalkyl group, and R 1 To R 16 The adjacent groups in the formula (5-H) may be bonded to each other to form a condensed ring, and at least one hydrogen in the formed ring may be substituted by an aryl group, a heteroaryl group (the heteroaryl group may be bonded to the formed ring via a single bond or a linking group), a diarylamino group, a diheteroarylamino group, an arylheteroarylamino group, an alkyl group, a cycloalkyl group, an alkenyl group, an alkoxy group or an aryloxy group, and at least one hydrogen in these groups may be substituted by an aryl group, a heteroaryl group, an alkyl group or a cycloalkyl group, and at least one hydrogen in the compound represented by the formula (5-H) may be substituted by a halogen, a cyano group or a deuterium group.

[0663] The details of each group in the definition of formula (5-H) can be referred to the description of the above-mentioned formula (1).

[0664] Examples of the alkenyl group in the definition of formula (5-H) include alkenyl groups having 2 to 30 carbon atoms, preferably alkenyl groups having 2 to 20 carbon atoms, more preferably alkenyl groups having 2 to 10 carbon atoms, further preferably alkenyl groups having 2 to 6 carbon atoms, and particularly preferably alkenyl groups having 2 to 4 carbon atoms. Preferred alkenyl groups are vinyl, 1-propenyl, 2-propenyl, 1-butenyl, 2-butenyl, 3-butenyl, 1-pentenyl, 2-pentenyl, 3-pentenyl, 4-pentenyl, 1-hexenyl, 2-hexenyl, 3-hexenyl, 4-hexenyl, or 5-hexenyl.

[0665] In addition, specific examples of heteroaryl groups include monovalent groups represented by removing any one hydrogen atom from the compounds of the following formula (5-Ar1), formula (5-Ar2), formula (5-Ar3), formula (5-Ar4) or formula (5-Ar5).

[0666] [Chemistry 114]

[0667]

[0668] In formula (5-Ar1) to formula (5-Ar5), Y 1 are independently O, S or NR, R is phenyl, biphenyl, naphthyl, anthracenyl or hydrogen, and at least one hydrogen in the structures of Formula (5-Ar1) to (5-Ar5) may be substituted by phenyl, biphenyl, naphthyl, anthracenyl, phenanthryl, methyl, ethyl, propyl, or butyl.

[0669] These heteroaryl groups may be linked to the dibenzoylmethane in formula (5-H) via a single bond or a linking group. That is, the dibenzo The skeleton and the heteroaryl group may be bonded not only directly but also via a linking group. Examples of the linking group include phenylene, biphenylene, naphthylene, anthracene, methylene, ethylene, -OCH2CH2-, -CH2CH2O-, or -OCH2CH2O-.

[0670] The compound represented by formula (5-H) is preferably 1 , R 4 , R 5 , R 8 , R 9 , R 12 , R 13 and R 16 In the above case, R in formula (5-H) 2 , R 3 , R 6 , R 7 , R 10 , R 11 , R 14 and R 15 Preferably, each of them is independently hydrogen, phenyl, biphenyl, naphthyl, anthracenyl, phenanthryl, a monovalent group having a structure of formula (5-Ar1), formula (5-Ar2), formula (5-Ar3), formula (5-Ar4) or formula (5-Ar5) (the monovalent group having the above structure can be connected with the dibenzofuran in formula (5-H) via phenylene, biphenylene, naphthylene, anthracenyl, methylene, ethylene, -OCH2CH2-, -CH2CH2O-, or -OCH2CH2O-) backbone bond), methyl, ethyl, propyl, or butyl.

[0671] The compound represented by formula (5-H) is more preferably R 1 , R 2 , R 4 , R 5 , R 7 , R 8 , R 9, R 10 , R 12 , R 13 , R 15 and R 16 In the above case, R in formula (5-H) 3 , R 6 , R 11 , R 14 At least one (preferably one or two, more preferably one) of the above is a monovalent group having a structure of formula (5-Ar1), formula (5-Ar2), formula (5-Ar3), formula (5-Ar4) or formula (5-Ar5) with an intervening single bond, phenylene, biphenylene, naphthylene, anthracene, methylene, ethylene, -OCH2CH2-, -CH2CH2O- or -OCH2CH2O-, and other than the above at least one (i.e., other than the position replaced by the monovalent group having the above structure) is hydrogen, phenyl, biphenylene, naphthyl, anthracene, methyl, ethyl, propyl or butyl, and at least one of the hydrogens may be substituted by phenyl, biphenylene, naphthyl, anthracene, methyl, ethyl, propyl or butyl.

[0672] In addition, as R in the formula (5-H) 2 , R 3 , R 6 , R 7 , R 10 , R 11 , R 14 and R 15 In the case of selecting a monovalent group having a structure represented by formula (5-Ar1) to formula (5-Ar5), at least one hydrogen in the structure can react with R in formula (5-H) 1 To R 16 to form a single bond.

[0673] As the main More specific examples of the compound include compounds represented by the following structural formulas.

[0674] [Chemistry 115]

[0675]

[0676] [Chemistry 116]

[0677]

[0678] [Compound represented by any one of formula (H1), formula (H2) and formula (H3)]

[0679] As the host material, for example, a compound represented by any of the following formula (H1), formula (H2), and formula (H3) can be used.

[0680] [Chemistry 117]

[0681]

[0682] In formula (H1), formula (H2) and formula (H3), L 1 is a single bond, or a divalent group containing at least an arylene group or a heteroarylene group. 1 L may be a single bond, or an arylene group having 6 to 24 carbon atoms, a heteroarylene group having 2 to 24 carbon atoms, a heteroarylene arylene group having 6 to 24 carbon atoms, or an arylene heteroarylene group having 6 to 24 carbon atoms, or a divalent group formed by linking any two of these groups by -O-, -S-, -CH2-, -Si(-Arx)2- (Arx is an aryl group) or a cycloalkylene group. 1 The arylene group in is preferably an arylene group having 6 to 16 carbon atoms, more preferably an arylene group having 6 to 12 carbon atoms, and particularly preferably an arylene group having 6 to 10 carbon atoms. Specifically, divalent groups such as a benzene ring, a biphenyl ring, a terphenyl ring, and a fluorene ring can be mentioned. 1 The heteroarylene group in the formula (I) is preferably a heteroarylene group having 2 to 24 carbon atoms, more preferably a heteroarylene group having 2 to 20 carbon atoms, further preferably a heteroarylene group having 2 to 15 carbon atoms, and particularly preferably a heteroarylene group having 2 to 10 carbon atoms. Specifically, examples thereof include a pyrrole ring, an oxazole ring, an isoxazole ring, a thiazole ring, an isothiazole ring, an imidazole ring, an oxadiazole ring (such as a furazan 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, divalent groups such as 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, phenoxathiol ring, phenoxazine ring, phenothiazine ring, phenazine ring, indolizine ring, furan ring, benzofuran ring, isobenzofuran ring, dibenzofuran ring, thiophene ring, benzothiophene ring, dibenzothiophene ring, and thianthrene ring. At least one hydrogen in the compounds represented by the above formulae may be substituted with at least one group selected from the substituent group Z or deuterium, for example, alkyl having 1 to 6 carbon atoms, cyano, halogen or deuterium.

[0683] As preferred specific examples, compounds represented by any of the following structural formulas can be cited. In addition, in the following structural formulas, at least one hydrogen can be substituted by halogen, cyano, alkyl having 1 to 4 carbon atoms (such as methyl or tert-butyl), phenyl or naphthyl.

[0684] [Chemistry 118]

[0685]

[0686] [Chemistry 119]

[0687]

[0688] [Chemistry 120]

[0689]

[0690] [Chemistry 121]

[0691]

[0692] [Hole-transporting host material (HH) and electron-transporting host material (EH)]

[0693] The hole transporting host material (HH) and the electron transporting host material (EH) satisfy the following relationship with respect to the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO).

[0694] The HOMO of the hole-transporting host material (HH) is shallower than the HOMO of the electron-transporting host material (EH), and the LUMO of the electron-transporting host material (EH) is deeper than the LUMO of the hole-transporting host material (HH).

[0695] In addition, it is preferred that the HOMO of the emissive dopant material is shallower than the HOMO of the hole-transporting host material (HH), or the LUMO of the emissive dopant material is deeper than the LUMO of the electron-transporting host material (EH).

[0696] In addition, from the viewpoint of promoting rather than inhibiting the generation of TADF in the light-emitting layer, the lowest excited triplet level (E T1 ) is higher than the highest E T1 The emission dopant material or auxiliary dopant E T1 Specifically, the E of the main material T1 Preferably, the E of the emitting dopant material or the auxiliary dopant is T1 It is higher by 0.01 eV or more, more preferably higher by 0.03 eV or more, and even more preferably higher by 0.1 eV or more. T1 It is preferably 2.47 eV or more, more preferably 2.49 eV or more, and further preferably 2.56 eV or more.

[0697] In addition, it is also preferred to use a hole transporting host material in the hole transport layer adjacent to the light-emitting layer, and to use an electron transporting host material in the electron transport layer adjacent to the light-emitting layer. This is because it is not easy to cause carrier leakage and energy leakage from the light-emitting layer to the adjacent layer, and a high-efficiency organic EL element can be obtained. The host material (hole transporting host material) in the light-emitting layer may be the same as or different from the hole transport layer material. In addition, the host material (electron transporting host material) in the light-emitting layer may be the same as or different from the material of the electron transport layer.

[0698] Examples of preferred hole transport host materials (HH) include compounds represented by formula (HH-1), or compounds having a partial structure represented by formula (HH-1) and having a structure containing at least three rings selected from the group consisting of an aryl ring and a heteroaryl ring. The compounds preferably do not contain an imine structure (-N=C-; partial structure containing a heteroaryl ring), boron (>B-), and a cyano group (CN).

[0699] [Chemistry 122]

[0700]

[0701] In formula (HH-1),

[0702] Q is >O, >S or >NA H ,

[0703] One carbon atom adjacent to the carbon atom bonded to Q in each of the two phenyl groups in formula (HH-1) may be bonded to each other via L.

[0704] L is a single bond, >O, >S or >C(-A H )2,

[0705] A H is hydrogen, aryl or heteroaryl, and >C(-A H ) The two A's in 2 H Can bond to each other.

[0706] When the hole transport host material includes the structure represented by formula (HH-1) as a partial structure, it may include one of the partial structures, but it is also preferred to include two or more. In the case of including two or more, the two or more partial structures may be the same as or different from each other. The two or more partial structures may be bonded to each other through a single bond, or they may be bonded in a manner that any ring contained in the partial structure is shared, or they may be bonded in a manner that any ring contained in the partial structure is condensed with each other. The partial structure may further have a substituent selected from an aryl group, a heteroaryl group, a diarylamino group, or an aryloxy group.

[0707] The compound represented by the formula (HH-1) or the compound having the partial structure represented by the formula (HH-1) has a structure containing at least three rings selected from the group consisting of aryl rings and heteroaryl rings. The number of rings contained is preferably 6 or more, more preferably 8 or more. In addition, it is preferably 20 or less, more preferably 15 or less, and further preferably 10 or less. The number of rings refers to the number of single rings, and with respect to condensed rings, it is the number obtained by counting the single rings constituting the condensed rings.

[0708] The hole transport host material is preferably a compound comprising one or more partial structures selected from the group consisting of a triarylamine structure, a carbazole ring, a dibenzofuran ring, a dibenzothiophene ring, and a condensed polycyclic ring containing phenoxazine or phenothiazine. The hole transport host material may contain one such partial structure, but preferably contains two or more. In the case of containing two or more, the two or more partial structures may be the same or different from each other.

[0709] Specific examples of the hole-transporting host material include the following compounds.

[0710] [Chemistry 123]

[0711]

[0712] [Chemistry 124]

[0713]

[0714] [Chemistry 125]

[0715]

[0716] [Chemistry 126]

[0717]

[0718] [Chemistry 127]

[0719]

[0720] [Chemistry 128]

[0721]

[0722] [Chemistry 129]

[0723]

[0724] [Chemistry 130]

[0725]

[0726] [Chemistry 131]

[0727]

[0728] [Chemistry 132]

[0729]

[0730] [Chemistry 133]

[0731]

[0732] [Chemistry 134]

[0733]

[0734] [Chemistry 135]

[0735]

[0736] Among the above, preferred are HH-1-1, HH-1-2, HH-1-4 to HH-1-12, HH-1-17, HH-1-18, HH-1-20 to HH-1-24, and HH-1 -82, HH-1-84~HH-1-89, HH-1-91, HH-1-92, HH-1-106~HH-1-108, and HH-1-109~HH-1-115.

[0737] Examples of electron transport host materials (EH) include compounds represented by formula (EH-1A) to (EH-1D), or compounds having partial structures represented by formula (EH-1A) to (EH-1D) and having a structure comprising at least three rings selected from the group consisting of aryl rings and heteroaryl rings.

[0738] [Chemistry 136]

[0739]

[0740] In Formula (EH-1A) to Formula (EH-1D),

[0741] Ar is a heteroaryl ring containing N═C as a partial structure constituting the ring,

[0742] Z is a single bond, -O-, -S-, or -N(-A E )-,

[0743] The carbon atoms adjacent to the carbon atom bonded to Z and the A atom bonded to Z E Can bond to each other through L,

[0744] L is a single bond, >O, >S or >C(-A E )2,

[0745] A E is an aryl group, a heteroaryl group or a triarylsilyl group. In formula (EH-1C), any one of A E It may be a diarylamino group,

[0746] Two A's bonded to the same atom E They can bond with each other using L.

[0747] X is C, P or S,

[0748] When X is C, n=2, m=1,

[0749] When X is P, n=3, m=1,

[0750] When X is S, n=2, m=1-2.

[0751] The compounds represented by the formula (EH-1A) to the formula (EH-1D), or the compounds having the partial structures represented by the formula (EH-1A) to the formula (EH-1D), have a structure containing at least three rings selected from the group consisting of aryl rings and heteroaryl rings. The number of rings contained is preferably 4 or more, more preferably 6 or more, and further preferably 8 or more. In addition, it is preferably 20 or less, more preferably 15 or less, and further preferably 10 or less. The number of rings refers to the number as a single ring, and with respect to a condensed ring, it is set to the number obtained by counting the single rings constituting the condensed ring.

[0752] When the electron transport host material includes the structure represented by formula (EH-1A) to formula (EH-1D) as a partial structure, it may include one of the partial structures, but it is also preferred to include two or more. In the case of including two or more, the two or more partial structures may be the same as or different from each other. The two or more partial structures may be bonded to each other by a single bond, or they may be bonded in a manner that any ring contained in the partial structure is shared, or they may be bonded in a manner that any ring contained in the partial structure is condensed with each other. The partial structure may further have a substituent selected from an aryl group, a heteroaryl group, a diarylamino group, or an aryloxy group.

[0753] Specific examples of the electron transporting host material include the following compounds.

[0754] [Chemistry 137]

[0755]

[0756] [Chemistry 138]

[0757]

[0758] [Chemistry 139]

[0759]

[0760] [Chemistry 140]

[0761]

[0762] [Chemistry 141]

[0763]

[0764] [Chemistry 142]

[0765]

[0766] [Chemistry 143]

[0767]

[0768] [Chemistry 144]

[0769]

[0770] [Chemistry 145]

[0771]

[0772] Other preferred examples of electron transport host materials (compounds having a partial structure represented by formula (EH-1)) include polycyclic aromatic compounds represented by the following formula (EH-1b) or polymers of polycyclic aromatic compounds having multiple structures represented by the following formula (EH-1b).

[0773] [Chemistry 146]

[0774]

[0775] In formula (EH-1b),

[0776] R 1 , R 2 , R 3 , R 4 and R 5 (hereinafter also referred to as “R 1 ", etc.) are each independently hydrogen or a substituent. The substituent only needs to be a substituent selected from the substituent group Z.

[0777] In formula (EH-1b), X 1 and X 2 Each of the following is independently >NR (amine nitrogen), >O, >C(-R)2, >S or >Se, X 1 and X 2 Different from >C(-R)2,

[0778] The R in the >NR and >C(-R)2 is independently hydrogen or a substituent selected from the substituent group Z, and may be further substituted by an aryl group, a heteroaryl group, an alkyl group or a cycloalkyl group (the above is the second substituent). The R in the >NR and >C(-R)2 may be independently bonded to at least one of the a ring, the b ring and the c ring through a linking group or a single bond.

[0779] Y 1 , Y 2 , Y 3 , Y 4 , Y 5 and Y 6 (hereinafter also referred to as "Y 1 ", etc.) are independently =C(-R)- or =N-(pyridinic nitrogen), at least one of which is =N-(pyridinic nitrogen),

[0780] The R in the ═C(—R)— is independently hydrogen or a substituent selected from the substituent group Z.

[0781] The R 1 , R 2 , R 3 , R 4 and R 5 , and as the Y 1 ~Y 6 Adjacent groups in R of =C(-R)- may bond to each other and form an aryl ring or a heteroaryl ring together with at least one of the a ring, b ring and c ring, and at least one hydrogen in the formed ring may be substituted by an aryl group, a heteroaryl group, a diarylamino group, a diheteroarylamino group, an arylheteroarylamino group, a diarylboryl group (two aryl groups may be bonded via a single bond or a linking group), an alkyl group, a cycloalkyl group, an alkoxy group or an aryloxy group (the above are the first substituents), and at least one hydrogen in these groups may be further substituted by an aryl group, a heteroaryl group, an alkyl group or a cycloalkyl group (the above are the second substituents).

[0782] At least one hydrogen in the compound and structure represented by formula (EH-1b) may be substituted by cyano, halogen or deuterium.

[0783] In formula (EH-1b), R 1 , R 2 , R 3 , R 4 and R 5 are hydrogen, or R 3 and R 4 are hydrogen and are selected from R 1 , R 2 and R 5Any one or more of the group is a substituent other than hydrogen, and the others are hydrogen. As a substituent, an alkyl group, an aryl group that may be substituted by an alkyl group or a heteroaryl group, a heteroaryl group that may be substituted by an alkyl group or an aryl group, or a diarylamino group that may be substituted by an alkyl group or an aryl group is preferred. At this time, as an alkyl group, an alkyl group having 1 to 6 carbon atoms (methyl, tert-butyl, etc.) is preferred, as an aryl group, a phenyl group or a biphenyl group is preferred, and as a heteroaryl group, a triazine group, a carbazolyl group (2-carbazolyl, 3-carbazolyl, 9-carbazolyl, etc.), a pyrimidinyl group, a pyridyl group, a dibenzofuranyl group or a dibenzothienyl group is preferred. As specific examples, phenyl, biphenyl, diphenyltriazine group, carbazolyltriazine group, monophenylpyrimidinyl group, diphenylpyrimidinyl group, carbazolyltriazine group, pyridyl group, dibenzofuranyl group and dibenzothienyl group can be cited.

[0784] Y 1 etc. are independently =C(-R)- or =N-, and at least one is =N-. 1 ~Y 6 Any of may be =N-. Preferably Y 1 and Y 6 =N-(ring a is a pyrimidine ring), Y 1 or Y 6 =N-(ring a is a pyridine ring), Y 2 and Y 5 =N- (ring b and ring c are pyridine rings), Y 3 and Y 4 =N- (ring b and ring c are pyridine rings), Y 2 ~Y 5 =N- (ring b and ring c are pyrimidine rings), Y 1 , Y 3 , Y 4 and Y 6 =N- (ring a is a pyrimidine ring, ring b and ring c are pyridine rings), Y 1 , Y 2 , Y 5 and Y 6 =N- (ring a is a pyrimidine ring, ring b and ring c are pyridine rings), Y 1 ~Y 6 =N- (ring a, ring b and ring c are pyrimidine rings), Y 2 or Y 5 =N- (the b ring or the c ring is a pyridine ring).

[0785] In addition to the above arrangement relationship of =N-, it is preferred that X 1 and X 2 is >0, and is preferably a polycyclic aromatic compound including a partial structure represented by any of the following formulae.

[0786] [Chemistry 147]

[0787]

[0788] In particular, polycyclic aromatic compounds containing a partial structure represented by formula (EH-1b-N1) have a higher E S1 , high E T1 , small ΔE S1T1 .

[0789] Specific examples of the polycyclic aromatic compound represented by formula (EH-1b) are shown below.

[0790] [Chemistry 148]

[0791]

[0792] [Chemistry 149]

[0793]

[0794] [Chemistry 150]

[0795]

[0796] [Chemistry 151]

[0797]

[0798] [Chemistry 152]

[0799]

[0800] [Chemistry 153]

[0801]

[0802] Among the above, preferred are EH-1-1 to EH-1-4, EH-1-10, EH-1-21 to EH-1-25, EH-1-32, EH-1-33, EH-1-51 to EH-1-59, EH-1-61, EH-1-66, EH-1-68, EH-1-71, and EH-1-7. 2. EH-1-90, EH-1-94~EH-1-99, EH-1-100, EH-1-101, EH-1-104, EH-1- 115. EH-1-117, EH-1-120, EH-1-122, EH-1-123, EH-1-127~EH-1-130.

[0803] [Combination of hole-transporting host material and electron-transporting host material]

[0804] The combination of the hole transporting host material and the electron transporting host material is determined by the HOMO, LUMO and the lowest excited triplet energy level (E T1 ) to select.

[0805] Regarding HOMO and LUMO, a combination is selected in which the HOMO (HH) of the hole-transporting host material is shallower than the HOMO (EH) of the electron-transporting host material, and the LUMO (EH) of the electron-transporting host material is deeper than the LUMO (HH) of the hole-transporting host material. More specifically, a combination in which HOMO (HH) is at least 0.10 eV shallower than HOMO (EH), and LUMO (HH) is at least 0.10 eV deeper than HOMO (EH) is preferably selected, a combination in which HOMO (HH) is at least 0.20 eV shallower than HOMO (EH), and LUMO (HH) is at least 0.20 eV deeper than HOMO (EH) is more preferably selected, and a combination in which HOMO (HH) is at least 0.25 eV shallower than HOMO (EH), and LUMO (HH) is at least 0.25 eV deeper than HOMO (EH) is further preferably selected.

[0806] The hole transporting host material and the electron transporting host material may be a combination of an association body called an exciplex. It is generally known that an exciplex is easily formed between a material having a relatively deep LUMO level and a material having a shallow HOMO level. Regarding the interaction between the hole transporting host material and the electron transporting host material, specifically whether an exciplex is formed, it can be judged in the following manner: a monolayer film containing only the hole transporting host material and the electron transporting host material is formed in the same manner as the formation conditions of the light-emitting layer, and the luminescence spectrum (fluorescence, phosphorescence spectrum) is measured. For the obtained luminescence spectrum, it is compared with the luminescence spectrum displayed by each of the hole transporting host material and the electron transporting host material separately. It can be judged in the following manner: the spectrum of the mixed film containing the hole transporting host material and the electron transporting host material shows a different luminescence wavelength from the spectrum of the film of the hole transporting host material and the spectrum of the film of the electron transporting host material. Specifically, as long as the peak wavelength of the spectrum differs by more than 10nm, it can be used as an indicator.

[0807] As specific examples of the combination of a hole transporting host material and an electron transporting host material that do not form an exciplex, the following combinations can be cited. T1The physical property values ​​of, in the hole transport host material, preferably a compound having carbazole, dibenzofuran, dibenzothiophene, triarylamine, indolecarbazole and benzoxazinephenoxazine as a partial structure, more preferably a compound having carbazole, dibenzofuran and dibenzothiophene as a partial structure, and further preferably a compound having carbazole as a partial structure. Similarly, in the electron transport host material, preferably a compound having pyridine, triazine, phosphine oxide, benzofuranopyridine and dibenzooxasiloline as a partial structure, more preferably a compound having triazine, phosphine oxide, benzofuranopyridine and dibenzooxasiloline as a partial structure, and further preferably a compound having triazine.

[0808] More specifically, the hole transport host material is preferably selected from the group consisting of HH-1-1, HH-1-2, HH-1-4 to HH-1-12, HH-1-17, HH-1-18, HH-1-20 to HH-1-24, HH-1-82, HH-1-84 to HH-1-89, HH-1-91, HH-1-92 and HH-1-106 to HH-1-108, and the electron transport host material is preferably selected from the group consisting of EH-1-1 to EH-1-4, EH-1-10, EH-1-21~EH-1-25, EH-1-32, EH-1-33, EH-1-51~EH-1-59, EH-1-61, EH-1-71, EH-1-72, EH-1-90, In the group consisting of EH-1-100, EH-1-101, EH-1-104, EH-1-117, EH-1-120, EH-1-122, EH-1-123, and EH-1-127~EH-1-130. Preferred examples of combinations include compound HH-1-1 and compound EH-1-22, compound HH-1-1 and compound EH-1-23, compound HH-1-1 and compound EH-1-24, compound HH-1-2 and compound EH-1-22, compound HH-1-2 and compound EH-1-23, compound HH-1-2 and compound EH-1-24, or compound HH-1-1 and compound EH-1-128.

[0809] As specific examples of the combination of a hole transporting host material and an electron transporting host material that form an exciplex, the following combinations can be cited. T1The physical property values ​​of, in the hole transport host material, preferably a compound having carbazole, triarylamine, indolecarbazole and benzoxazine-phenoxazine as a partial structure, more preferably a compound having triarylamine, indolecarbazole and benzoxazine-phenoxazine as a partial structure, and further preferably a compound having triarylamine as a partial structure. Similarly, in the electron transport host material, preferably a compound having pyridine, triazine, phosphine oxide and benzofuranopyridine as a partial structure, more preferably a compound having triazine, phosphine oxide, benzofuranopyridine and dibenzooxasiloline as a partial structure, and further preferably a compound having phosphine oxide and triazine.

[0810] More specifically, the hole transport host material is preferably selected from the group consisting of HH-1-1, HH-1-2, HH-1-11, HH-1-12, HH-1-17, HH-1-18, HH-1-23, HH-1-24, and HH-1-115, and the electron transport host material is preferably selected from the group consisting of EH-1-1 to EH-1-4, EH-1-21 to EH-1-25, EH-1 -51~EH-1-57, EH-1-59, EH-1-66, EH-1-68, EH-1-90, EH-1-94, EH-1-99, EH-1-100, EH-1-101, EH-1-104, EH-1-117, EH-1-120, EH-1-122, EH-1-123, and the group consisting of EH-1-127~EH-1-130. Preferred examples of combinations include compound HH-1-1 and compound EH-1-21, compound HH-1-2 and compound EH-1-21, compound HH-1-12 and compound EH-1-94, compound HH-1-12 and compound EH-1-117, compound HH-1-1 and compound EH-1-130, compound HH-1-33 and compound EH-1-117, compound HH-1-48 and compound EH-1-117 or compound HH-1-49 and compound EH-1-117, and compound HH-1-115 and compound EH-1-99.

[0811] In addition, for specific combinations of hole-transporting host materials and electron-transporting host materials, please refer to: Organic Electronics (66 (2019) 227-24), Advanced Functional Materials (25 (2015) 361-366.), Advanced Materials (26 (2014) 4730-4734.), ACS Applied Materials and Interfaces (8 (2016) 32984-32991.), ACS Applied Materials and Interfaces (2016, 8, 9806-9810), ACS Applied Materials and Interfaces (2016, 8, 32984-32991), Journal of Materials Chemistry (Journal of Materials Chemistry) Materials Chemistry" (C, 2018, 6, 8784-8792), "Angewandte Chemie International Edition." (2018, 57, 12380-12384), "Advanced Functional Materials" (24, 2014, 3970), "Advanced Materials" (26, 2014, 5684), "Synthetic Metals" (201, 2015, 49), and "Nature Photonics" (16, 212-218 (2022)).

[0812] <Assisted dopant (thermally activated delayed phosphor or phosphorescent material)>

[0813] The light-emitting layer also preferably contains an emitting dopant, a host material, and an auxiliary dopant. The auxiliary dopant is preferably a thermally activated delayed fluorescent substance or a phosphorescent material.

[0814] As described above, the polycyclic aromatic compound including the structural unit represented by the formula (1) has its interaction with adjacent molecules suppressed, and can be preferably used as an emitting dopant for a TAF device or a PSF device.

[0815] In the present embodiment, as the main compound, a known compound can be used, for example, a compound having at least one of a carbazole ring and a furan ring can be listed, wherein it is preferably a compound formed by bonding at least one of a furanyl group and a carbazole group to at least one of an arylene group and a heteroarylene group. As a specific example, compounds represented by any one of formula (H1), formula (H2) and formula (H3), in particular mCP or mCBP, etc. can be listed. In addition, TADF-active compounds can also be used in the main compound. In the present embodiment, it is also preferred to use a combination of a hole transporting main material and an electron transporting main material as the main body.

[0816] From the viewpoint of promoting rather than hindering the generation of TADF in the light-emitting layer, the lowest excited triplet energy level E(1, T, Sh) of the main compound obtained from the shoulder peak on the short-wavelength side of the peak of the phosphorescence spectrum is preferably higher than the lowest excited triplet energy levels E(2, T, Sh) and E(3, T, Sh) of the emitting dopant or auxiliary dopant having the highest lowest excited triplet energy level in the light-emitting layer. Specifically, compared with E(2, T, Sh) and E(3, T, Sh), the lowest excited triplet energy level E(1, T, Sh) of the main compound is preferably 0.01 eV or more higher, more preferably 0.03 eV or more higher, and further preferably 0.1 eV or more higher.

[0817] [Thermally activated delayed phosphor]

[0818] The so-called "thermally activated delayed fluorescence" refers to a compound that absorbs thermal energy and undergoes reverse intersystem crossing from the lowest excited triplet state to the lowest excited singlet state, and is radiatively deactivated from the lowest excited singlet state, thereby emitting delayed fluorescence. The so-called "thermally activated delayed fluorescence" also includes the case where a higher-order triplet state is passed during the excitation process from the lowest excited triplet state to the lowest excited singlet state. For example, there are the papers published by Monkman et al. of Durham University (Nature Communications (7: 13680, digital object identifier (DOI) : 10.1038 / ncomms13680)), the papers published by Hosokai et al. of the National Institute of Advanced Industrial Science and Technology (Hosokai et al., Science Advances (Sci. Adv.) (2017; 3: e1603282)), and the papers published by Sato et al. of Kyoto University (Scientific Reports (2017)). 4820, DOI: 10.1038 / s41598-017-05007-7)), and a society paper by Sato et al. of Kyoto University (98th Spring Annual Meeting of the Chemical Society of Japan, publication number: 2I4-15, "Mechanism of high-efficiency luminescence in organic electroluminescence using diazaboranaphthoanthracene (DABNA) as a luminescent molecule," Journal of the Graduate School of Engineering, Kyoto University The present invention relates to a sample containing a target compound, and the target compound is determined to be a "thermally activated delayed fluorescent substance" by observing a slow fluorescent component when the fluorescence lifetime is measured at 300K. Here, the so-called slow fluorescent component refers to a component with a fluorescence lifetime of 0.1 μsec or more. The fluorescence lifetime can be measured, for example, using a fluorescence lifetime measuring apparatus (manufactured by Hamamatsu Photonics Co., Ltd., C11367-01).

[0819] In the light-emitting layer further including a "thermally active delayed phosphor" as an auxiliary dopant, the polycyclic aromatic compound of the present invention can function as an emitting dopant. That is, the "thermally active delayed phosphor" can function as an auxiliary dopant that assists the light emission of the polycyclic aromatic compound of the present invention.

[0820] In this specification, an organic electroluminescent element using a thermally activated delayed phosphor as an assisting dopant may be referred to as a "TAF element" (TADF Assisting Fluorescence element).

[0821] The so-called "host compound" in the TAF element refers to a compound whose lowest excited singlet energy level obtained from the shoulder peak on the short-wavelength side of the peak of the fluorescence spectrum is higher than the lowest excited singlet energy level of the thermally active delayed phosphor as an auxiliary dopant and the emitting dopant.

[0822] The thermally active delayed phosphor (TADF compound) used in the TAF element is preferably the following donor-acceptor type thermally active delayed phosphor (DA-type TADF compound): it is designed to use an electron-donating substituent called a donor and an electron-accepting substituent called an acceptor to localize the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) in the molecule to produce efficient reverse intersystem crossing.

[0823] Here, in this specification, the so-called "electron donating substituent" (donor) refers to the substituent and partial structure locally present at HOMO in the thermally active delayed phosphor molecule, and the so-called "electron accepting substituent" (acceptor) refers to the substituent and partial structure locally present at LUMO in the thermally active delayed phosphor molecule.

[0824] Generally speaking, due to the structure of the thermally activated delayed fluorescent material using donors or acceptors, the spin orbit coupling (SOC) is large, and the exchange interaction between HOMO and LUMO is small, so ΔE S1T1Small, so a very fast reverse intersystem crossing speed can be obtained. By using the polycyclic aromatic compound of the present invention as an emitting dopant and using a thermally active delayed phosphor (TADF material) as an auxiliary dopant, an element that satisfies any one or all of high efficiency, high color purity and long life can be provided. The thermally active delayed phosphor can be any compound whose luminescence spectrum overlaps at least partially with the absorption spectrum of the polycyclic aromatic compound of the present invention. The polycyclic aromatic compound and the thermally active delayed phosphor of the present invention may be both contained in the same layer, or in adjacent layers or other adjacent layers.

[0825] As the thermally active delayed phosphor in the TAF element, for example, a compound in which a donor and an acceptor are bonded directly or via a spacer can be used. As the electron-donating group (donor structure) and the electron-accepting group (acceptor structure) used in the thermally active delayed phosphor of the present invention, for example, the structure described in "Chemistry of Materials" (2017, 29, 1946-1963) can be used. Examples of the donor structure include carbazole, dimethylcarbazole, di-tert-butylcarbazole, dimethoxycarbazole, tetramethylcarbazole, benzofluorocarbazole, benzothiophenocarbazole, phenyldihydroindolecarbazole, phenylbicarbazole, bicarbazole, tercarbazole, diphenylcarbazole-based amine, tetraphenylcarbazole-based diamine, phenoxazine, dihydrophenazine, phenothiazine, dimethyldihydroacridine, diphenylamine, bis(tert-butylphenyl)amine, N1-(4-(diphenylamino)phenyl)-N4,N4-diphenylbenzene-1,4-diamine, dimethyltetraphenyldihydroacridine diamine, tetramethyl-dihydro-indenoacridine and diphenyl-dihydrodibenzazasilin, etc. Examples of the acceptor structure include sulfonyldiphenyl, benzophenone, phenylenebis(phenyl ketone), benzonitrile, isonicotinonitrile, phthalonitrile, isophthalonitrile, terephthalonitrile, benzenetricarbonitrile, triazole, oxazole, thiadiazole, benzothiazole, benzobis(thiazole), benzoxazole, benzobis(oxazole), quinoline, benzimidazole, dibenzoquinoxaline, heptaazaphenalene, thioxanthone dioxide, dimethylanthrone, anthracene dione, 5H-cycloheptyl[1,2-b:5,4-b′]bipyridine, fluorene dicarbonitrile, triphenyltriazine, pyrazine dicarbonitrile, pyrimidine, phenylpyrimidine, methylpyrimidine, pyridine dicarbonitrile, dibenzoquinoxaline dicarbonitrile, bis(phenylsulfonyl)benzene, dimethylthioxanthene dioxide, thianthracene tetraoxide, and tri(dimethylphenyl)borane. In particular, the compound having thermally activated delayed fluorescence in the TAF element is preferably a compound having at least one selected from carbazole, phenoxazine, acridine, triazine, pyrimidine, pyrazine, thioxanthene, benzonitrile, phthalonitrile, isophthalonitrile, diphenyl sulfone, triazole, oxadiazole, thiadiazole and benzophenone as a partial structure.

[0826] The compound used as an auxiliary dopant of the light-emitting layer in the TAF device is preferably a thermally activated delayed phosphor, and its emission spectrum at least partially overlaps with the absorption peak of the emitting dopant.

[0827] [Phosphorescent materials (auxiliary dopants)]

[0828] In the light-emitting layer, a phosphorescent material can be used as an auxiliary dopant. In this specification, an organic electroluminescent element using a phosphorescent material as an auxiliary dopant is sometimes referred to as a phosphorescent auxiliary element: a phosphor-sensitized fluorescent element, a PSF element. Phosphorescent materials utilize the intramolecular spin-orbit interaction (heavy atom effect) caused by metal atoms to obtain light emission from an excited triplet state. As such a phosphorescent material, for example, a luminescent metal complex can be used. As the luminescent metal complex, for example, compounds represented by the following formula (B-1) and the following formula (B-2) can be listed.

[0829] [Chemistry 154]

[0830]

[0831] 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 of 1 to 3, and "XY" are each independently a bidentate ligand.

[0832] In formula (B-2), M is at least one selected from the group consisting of Pt, Re and Cu, and "WXYZ" is a tetradentate ligand.

[0833] In formula (B-1), M is preferably Ir and n is preferably 3 from the viewpoint of efficiency and life.

[0834] In formula (B-2), M is preferably Pt from the viewpoint of efficiency and life.

[0835] The ligand (XY) in formula (B-1) has at least one ligand selected from the group consisting of: The ligand (WXYZ) in formula (B-2) has at least one ligand selected from the group consisting of: as a part thereof.

[0836] [Chemistry 155]

[0837]

[0838] In the formula,

[0839] It is bonded to the central metal M at ---,

[0840] Y is independently BRe NR e , PR e ,O,S,Se,C=O,S=O,SO2,CR e R f 、SiR e R f , or GeR e R f , the aromatic carbon CH in the ring can be substituted by N independently,

[0841] R e and R f Can be condensed or bonded to form a ring,

[0842] R a , R b , R c and R d Each independently is unsubstituted or substituted to a range from 1 to the maximum number of substitutions possible,

[0843] R a , R b , R c , R d , R e , and R f are independently hydrogen, deuterium, halide, alkyl, cycloalkyl, heteroalkyl, alkoxy, aryloxy, amino, silanyl, alkenyl, cycloalkenyl, heteroalkenyl, aryl, heteroaryl, nitrile, isonitrile, thiol or a combination thereof,

[0844] Among them, R a , R b , R c , and R d Any two adjacent substituents in the group may be condensed or bonded to form a ring, or may form a multidentate ligand.

[0845] Examples of the compound represented by formula (B-1) include 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), and fac-Tris(2-(3-p-xylyl)phenyl)pyridine iridium(III)(fac-tris(2-(3-p-xylyl)phenyl)pyridinium(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.

[0846] Examples of the compound represented by formula (B-1) include the following compounds in addition to the above.

[0847] [Chemistry 156]

[0848]

[0849] [Chemistry 157]

[0850]

[0851] [Chemistry 158]

[0852]

[0853] 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, and Japanese Patent Laid-Open No. 2004-111379, U.S. Patent Application Publication No. 2019 / 0051845, or Advanced Materials (26: 7116-7121), Nature Asia Materials (NPG Asia Materials) (13, 53 (2021)), Applied Physics Letters (Applied Physics Letters) (117, 253301 (2020)), Light-Emitting Diode-An Outlook On the Empirical Features and Its Recent Technological Progress Outlook (Light-Emitting Diode-An Outlook On the Empirical Features and Its Recent Technological Progress Outlook) can also be used. The platinum complex described in "Technological Advances" (Chapter 5).

[0854] <Other dopant materials>

[0855] The polycyclic aromatic compound containing the structural unit represented by formula (1) can be used in combination with other dopant materials. In one light-emitting layer, the other dopant materials are preferably less than 100% by mass, more preferably less than 50% by mass, further preferably less than 30% by mass, and particularly preferably less than 10% by mass, relative to the total mass of the polycyclic aromatic compound containing the structural unit represented by formula (1). As other dopant materials, known compounds can be used, and they can be selected from various materials according to the desired luminescent color. Specifically, for example, phenanthrene, anthracene, pyrene, tetracene, pentacene, perylene, naphthopyrene, dibenzopyrene, rubrene, and Condensed ring derivatives such as 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 stilbenebenzene derivatives such as bisstyrylanthracene derivatives (Japanese Patent Laid-Open No. 1-245087), bisstyrylarylene derivatives (Japanese Patent Laid-Open No. 2-247278), diazabenzodiindene derivatives, furan derivatives, benzofuran derivatives, phenylisobenzofuran, dimesitylisobenzofuran, di(2-methylphenyl)isobenzofuran, di(2-trifluoromethylphenyl)isobenzofuran, isobenzofuran derivatives such as phenylisobenzofuran, dibenzofuran derivatives, 7-dialkylaminocoumarin derivatives, 7- Coumarin derivatives such as piperidinyl coumarin derivatives, 7-hydroxycoumarin derivatives, 7-methoxycoumarin derivatives, 7-acetoxycoumarin derivatives, 3-benzothiazolyl coumarin derivatives, 3-benzimidazolyl coumarin derivatives, 3-benzoxazolyl coumarin derivatives, dicyanomethylene pyran derivatives, dicyanomethylene thiopyran derivatives, polymethine derivatives, cyanine derivatives, oxybenzanthracene derivatives, xanthene derivatives, rhodamine derivatives, fluorescein Derivatives, pyrylium derivatives, quinolone derivatives, acridine derivatives, oxazine derivatives, phenyl ether derivatives, quinacridone derivatives, quinazoline derivatives, pyrrolopyridine derivatives, furanopyridine derivatives, 1,2,5-thiadiazolopyrene derivatives, pyrromethene derivatives, purple ring ketone derivatives, pyrrolopyrrole derivatives, squarylium salt derivatives, purple anthrone derivatives, phenazine derivatives, acridone derivatives, deazotflavin derivatives, fluorene derivatives and benzofluorene derivatives, etc.

[0856] As other dopant materials, it is also preferable to use a polycyclic aromatic compound containing boron described in International Publication No. 2015 / 102118, International Publication No. 2020 / 162600, paragraphs 0097 to 0269 of Japanese Patent Application Laid-Open No. 2021-077890, and the like.

[0857] 2-1-6. Electron injection layer and electron transport layer in organic electroluminescent element

[0858] The electron injection layer 107 plays a role of efficiently injecting electrons migrated from the cathode 108 into the light-emitting layer 105 or the electron transport layer 106. The electron transport layer 106 plays a role of efficiently transporting electrons injected from the cathode 108 or 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 stacking or mixing one or more electron transport / injection materials, or are formed by a mixture of an electron transport / injection material and a polymer binder.

[0859] The so-called electron injection / transport layer is a layer responsible for injecting electrons from the cathode and then transmitting electrons, and it is desirable that the electron injection efficiency is high and the injected electrons are transmitted efficiently. Therefore, it is preferably a material with large electron affinity, large electron mobility, excellent stability, and impurities that are not easy to produce when manufacturing and using it. However, considering the transmission balance of holes and electrons, in the case of mainly playing the role of efficiently preventing the holes from the anode from being recombined and flowing to the cathode side, even if the electron transmission ability is not so high, it has the effect of improving luminous efficiency equally with the material with high electron transmission ability. Therefore, the electron injection / transport layer in the present embodiment may also include the function of the layer that can efficiently prevent the migration of holes.

[0860] The material (electron transport material) for forming the electron transport layer 106 or the electron injection layer 107 can be arbitrarily selected from compounds conventionally used as electron transfer compounds in photoconductive materials and known compounds used in electron injection layers and electron transport layers of organic EL elements.

[0861] As the material used in the electron transport layer or the electron injection layer, it is preferably containing at least one selected from the following compounds: a compound containing an aromatic ring or 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 with electron-accepting nitrogen. Specifically, it can be listed: condensed ring aromatic ring derivatives such as naphthalene and anthracene, styrene aromatic ring derivatives represented by 4,4'-bis(diphenylvinyl)biphenyl, purple ring ketone derivatives, coumarin derivatives, naphthalene dicarboximide derivatives, quinone derivatives such as anthraquinone or diphenoquinone, phosphine oxide derivatives, aryl nitrile derivatives and indole derivatives. As a metal complex with electron-accepting nitrogen, for example, hydroxyl azole complexes such as hydroxyphenyloxazole complexes, azomethine complexes, tropolone metal complexes, flavonol metal complexes and benzoquinoline metal complexes can be listed. These materials can be used alone or mixed with different materials.

[0862] In addition, specific examples of other electron transfer compounds include pyridine derivatives, naphthalene derivatives, anthracene derivatives, phenanthroline derivatives, perirone derivatives, coumarin derivatives, naphthalimide derivatives, anthraquinone derivatives, diphenoquinone derivatives, diphenylquinone derivatives, perylene derivatives, oxadiazole derivatives (1,3-bis[(4-tert-butylphenyl)1,3,4-oxadiazolyl]phenylene, etc.), thiophene derivatives, triazole derivatives (N-naphthyl-2,5-diphenyl-1,3,4-triazole, etc.), thiadiazole derivatives, metal complexes of 8-hydroxyquinoline derivatives, hydroxyquinoline metal complexes, quinoxaline derivatives, polymers of quinoxaline derivatives, benzoazole compounds, gallium complexes, pyrazole derivatives, perfluorinated phenylene derivatives, Biologicals, triazine derivatives, pyrazine derivatives, benzoquinoline derivatives (2,2'-bis(benzo[h]quinolin-2-yl)-9,9'-spirobifluorene, etc.), imidazopyridine derivatives, borane derivatives, benzimidazole derivatives (tris(N-phenylbenzimidazol-2-yl)benzene, etc.), benzoxazole derivatives, benzothiazole derivatives, quinoline derivatives, oligopyridine derivatives such as terpyridine, bipyridine derivatives, terpyridine derivatives (1,3-bis(2,2':6',2"-terpyridine-4'-yl)benzene, etc.), naphthyridine derivatives (bis(1-naphthyl)-4-(1,8-naphthyridin-2-yl)phenylphosphine oxide, etc.), aldazine derivatives, carbazole derivatives, indole derivatives, phosphine oxide derivatives, bisphenylvinyl derivatives, etc.

[0863] In addition, metal complexes having electron-accepting nitrogen can also be used, examples of which include hydroxyquinoline metal complexes, hydroxyoxazole complexes such as hydroxyphenyloxazole complexes, azomethine complexes, tropolone metal complexes, flavonol metal complexes, and benzoquinoline metal complexes.

[0864] The materials can be used alone or in combination with different materials.

[0865] Among the above materials, preferred are borane derivatives, pyridine derivatives, fluoranthene derivatives, BO derivatives, anthracene derivatives, benzofluorene derivatives, phosphine oxide derivatives, pyrimidine derivatives, aromatic nitrile derivatives, triazine derivatives, benzimidazole derivatives, phenanthroline derivatives, and hydroxyquinoline metal complexes.

[0866] The electron transport layer or the electron injection layer may further contain a substance that can reduce the material forming the electron transport layer or the electron injection layer. The reducing substance may be a variety of substances as long as it has a certain reducing property, for example, at least one selected from the group consisting of alkali metals, alkaline earth metals, rare earth metals, alkali metal oxides, alkali metal halides, alkaline earth metal oxides, alkaline earth metal halides, rare earth metal oxides, rare earth metal halides, alkali metal organic complexes, alkaline earth metal organic complexes, and rare earth metal organic complexes can be preferably used.

[0867] As preferred reducing substances, alkali metals such as Na (work function 2.36eV), K (work function 2.28eV), Rb (work function 2.16eV) or Cs (work function 1.95eV) or alkaline earth metals such as Ca (work function 2.9eV), Sr (work function 2.0eV~2.5eV) or Ba (work function 2.52eV) can be listed, and substances with a work function of 2.9eV or less are particularly preferred. Among these, the more preferred reducing substances are alkali metals of K, Rb or Cs, and more preferably Rb or Cs, and most preferably Cs. The reducing 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, the luminous brightness in the organic EL element can be improved or the life can be prolonged. In addition, as the reducing substance having 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 including Cs, the reducing ability can be efficiently exerted, and by adding it to the material forming the electron transport layer or the electron injection layer, the luminance of the light emission in the organic EL element can be improved or the life can be prolonged.

[0868] 2-1-7. Cathode in organic electroluminescent element

[0869] The cathode 108 plays a role of injecting electrons into the light-emitting layer 105 via the electron injection layer 107 and the electron transport layer 106 .

[0870] As the material forming the cathode 108, if it is a substance that can efficiently inject electrons into the organic layer, it is not particularly limited, and the same material as the material forming the anode 102 can be used. Among them, preferably metals such as tin, indium, calcium, aluminum, silver, copper, nickel, chromium, gold, platinum, iron, zinc, lithium, sodium, potassium, cesium and magnesium or their alloys (magnesium-silver alloy, magnesium-indium alloy, aluminum-lithium alloy such as lithium fluoride / aluminum, etc.) and the like. In order to improve the efficiency of electron injection to improve the characteristics of the element, lithium, sodium, potassium, cesium, calcium, magnesium or alloys containing these low work function metals are effective. However, generally speaking, these low work function metals are unstable in the atmosphere in most cases. In order to improve this point, it is known that there is a method of doping a trace amount of lithium, cesium or magnesium into the organic layer and using an electrode with high stability. As other dopants, inorganic salts such as lithium fluoride, cesium fluoride, lithium oxide and cesium oxide can also be used. Among them, it is not limited to these.

[0871] Furthermore, the following are preferred examples: in order to protect the electrode, metals such as platinum, gold, silver, copper, iron, tin, aluminum and indium, or alloys of these metals, inorganic substances such as silicon dioxide, titanium dioxide and silicon nitride, polyvinyl alcohol, vinyl chloride, hydrocarbon polymer compounds, etc. are stacked. The method for making these electrodes is not particularly limited as long as it is a method that can achieve conduction such as resistance heating, electron beam evaporation, sputtering, ion plating and coating.

[0872] 2-1-8. Method for producing organic electroluminescent element

[0873] Each layer constituting the organic EL element can be formed by making the material to constitute each layer into a thin film using a method such as vapor deposition, resistance heating vapor deposition, electron beam vapor deposition, sputtering, molecular stacking, printing, spin coating, casting, coating, 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 generally in the range of 2nm to 5000nm. The film thickness can generally be measured using a quartz oscillation film thickness measuring device or the like. When using the vapor deposition method for thin film formation, the vapor deposition conditions vary depending on the type of material, the target crystal structure and association structure of the film, etc. The vapor deposition conditions are generally preferably a boat heating temperature of +50°C to +400°C and a vacuum degree of 10 -6 Pa~10 -3 Pa, the vapor deposition rate is 0.01 nm / sec to 50 nm / sec, the substrate temperature is -150°C to +300°C, and the film thickness is appropriately set within the range of 2 nm to 5 μm.

[0874] When a direct current voltage is applied to the organic EL element obtained in the above manner, it can be applied with the anode as + polarity and the cathode as - polarity. If a voltage of about 2V to 40V is applied, light emission can be observed from the transparent or translucent electrode side (anode or cathode, or both). In addition, the organic EL element also emits light when a pulse current or an alternating current is applied. In addition, the waveform of the applied alternating current can be arbitrary.

[0875] Next, as an example of a method for producing an organic EL element, a method for producing an organic EL element including anode / hole injection layer / hole transport layer / light-emitting layer including a host material and a dopant material / electron transport layer / electron injection layer / cathode is described.

[0876] <Evaporation method>

[0877] On a suitable substrate, a thin film of an anode material is formed by a vapor deposition method to make an anode, and then a thin film of a hole injection layer and a hole transport layer is formed on the anode. The main material and the dopant material are co-evaporated on the thin film to form a thin film as a light-emitting layer, and an electron transport layer and an electron injection layer are formed on the light-emitting layer, and then a thin film containing a cathode material is formed by a vapor deposition method as a cathode, thereby obtaining a target organic EL element. In addition, in the production of the organic EL element, the production order can also be reversed, and the cathode, electron injection layer, electron transport layer, light-emitting layer, hole transport layer, hole injection layer, anode are produced in the order of cathode, electron injection layer, electron transport layer, light-emitting layer, hole transport layer, hole injection layer, anode.

[0878] <Wet film forming method>

[0879] A low molecular weight compound capable of forming each organic layer of an organic EL element is prepared as a liquid organic layer-forming composition, and the composition is used to perform a wet film-forming method. In the absence of an appropriate organic solvent for dissolving the low molecular weight compound, the organic layer-forming composition may be prepared from a high molecular weight compound or the like, wherein the high molecular weight compound is polymerized together with other monomers or main chain polymers having a solubility function as a reactive compound substituted with a reactive substituent in the low molecular weight compound.

[0880] The wet film forming method generally forms a coating film by passing through the following process, wherein the process is a coating process of applying an organic layer forming composition on a substrate and a drying process of removing a solvent from the coated organic layer forming composition. In the case where the polymer compound has a cross-linking substituent (also referred to as a cross-linking polymer compound), the drying process is further cross-linked to form a polymer cross-linked body. Depending on the coating process, the method using a spin coater is called a spin coating method, the method using a slit coater is called a slit coating method, the method using a plate is called a gravure, lithography, reverse lithography, flexographic printing method, the method using an inkjet printer is called an inkjet method, and the method of blowing with a mist is called a spray method. There are methods such as air drying, heating, and reduced pressure drying in the drying process. The drying process can be performed only once, or it can be performed multiple times using different methods or conditions. In addition, for example, different methods can also be used, such as calcination under reduced pressure.

[0881] The wet film forming method refers to a film forming method using a solution, such as a partial printing method (inkjet method), a spin coating method or a casting method, a coating method, etc. The wet film forming method is different from the vacuum evaporation method in that it does not require the use of an expensive vacuum evaporation device and can be formed under atmospheric pressure. In addition, the wet film forming method can be large-scale or continuously produced, thereby reducing manufacturing costs.

[0882] On the other hand, compared with the vacuum evaporation method, the wet film forming method is sometimes difficult to laminate. When using the wet film forming method to make a laminated film, 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 an orthogonal solvent (orthogonal solvent, mutually insoluble solvent) etc. However, there are cases where it is difficult to use the wet film forming method for coating all films even if these technologies are used.

[0883] Therefore, a method is generally adopted in which only some layers are formed by a wet film-forming method and the remaining layers are formed by a vacuum deposition method to produce an organic EL element.

[0884] For example, the following shows a part of the procedure for manufacturing an organic EL element by applying the wet film formation method.

[0885] (Procedure 1) Anode film formation by vacuum deposition method

[0886] (Procedure 2) Film formation of a hole injection layer-forming composition containing a hole injection layer material by a wet film formation method

[0887] (Procedure 3) Film formation of a hole transport layer-forming composition containing a hole transport layer material by a wet film formation method

[0888] (Procedure 4) Film formation of a composition for forming a light-emitting layer containing a host material and a dopant material by a wet film formation method

[0889] (Procedure 5) Film formation of electron transport layer by vacuum deposition method

[0890] (Procedure 6) Film formation of electron injection layer by vacuum deposition method

[0891] (Procedure 7) Cathode film formation by vacuum deposition method

[0892] By going through the above process, an organic EL element including anode / hole injection layer / hole transport layer / light-emitting layer including a host material and a dopant material / electron transport layer / electron injection layer / cathode can be obtained.

[0893] Of course, for the electron transport layer and the electron injection layer, a layer-forming composition containing an electron transport layer material and an electron injection layer material can also be used to form a film by a wet film-forming method. In this case, it is preferred to use a method that prevents the lower light-emitting layer from dissolving, or a method of forming a film from the cathode side in the opposite manner to the above procedure.

[0894] <Other film forming methods>

[0895] Laser heating drawing method (Laser Induced Thermal Imaging (LITI)) can be used for 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.

[0896] <Optional process>

[0897] Before and after each film forming step, appropriate treatment steps, cleaning steps and drying steps may be appropriately added. Examples of treatment steps include exposure treatment, plasma surface treatment, ultrasonic treatment, ozone treatment, cleaning treatment using an appropriate solvent and heating treatment. Furthermore, a series of steps for making a bank may be mentioned.

[0898] Photolithography can be used in the production of the bank. As the bank material that can be photolithographically processed, positive resist materials and negative resist materials can be used. In addition, printing methods that can be patterned, such as inkjet printing, gravure lithography, reverse lithography, and screen printing, can also be used. At this time, a permanent resist material can also be used.

[0899] <Organic layer forming composition used in wet film forming method>

[0900] The composition for forming an organic layer is obtained by dissolving a low molecular compound that can form each organic layer of an organic EL element, or a high molecular compound obtained by polymerizing the low molecular compound, in an organic solvent. For example, the composition for forming a luminescent layer contains at least one dopant material, i.e., a polycyclic aromatic compound (or its high molecular compound) as a first component, at least one main material as a second component, and at least one organic solvent as a third component. The first component functions as a dopant component of the luminescent layer obtained from the composition, and the second component functions as a main component of the luminescent layer. The third component functions as a solvent that dissolves the first component and the second component in the composition, and provides a smooth and uniform surface shape by using the controlled evaporation rate of the third component itself during coating.

[0901] <Organic solvent>

[0902] The organic layer forming composition comprises at least one organic solvent. By controlling the evaporation rate of the organic solvent during film formation, the film forming property and the presence or absence of defects, surface roughness, and smoothness of the coating film can be controlled and improved. In addition, when using the inkjet method for film formation, the stability of the meniscus at the pinhole of the inkjet head can be controlled, and the ejection property can be controlled / improved. In addition, by controlling the drying rate of the film and the orientation of the derivative molecules, the electrical properties, luminescent properties, efficiency, and life of the organic EL element having the organic layer obtained by the organic layer forming composition can be improved.

[0903] The organic solvent is removed from the coating by drying processes such as vacuum, decompression, heating, etc. after film formation. When heating, from the perspective of improving the coating film-forming property, it is preferably carried out below the glass transition temperature (Tg) of at least one of the solutes + 30 ° C. In addition, from the perspective of reducing the residual solvent, it is preferably heated above the glass transition temperature (Tg) of at least one of the solutes -30 ° C. Even if the heating temperature is lower than the boiling point of the organic solvent, the organic solvent is also fully removed because the film is thin. In addition, it can be dried multiple times at different temperatures, and a variety of drying methods can also be used in combination.

[0904] (2) Specific examples of organic solvents

[0905] As the organic solvent used in the composition for forming the organic layer, alkylbenzene solvents, phenyl ether solvents, alkyl ether solvents, cyclic ketone solvents, aliphatic ketone solvents, monocyclic ketone solvents, solvents having a diester skeleton, and fluorine-containing solvents can be cited, but are not limited thereto. In addition, the solvents can be used alone or in combination.

[0906] <Optional ingredients>

[0907] The composition for forming an organic layer may contain an optional component within a range that does not impair its properties. Examples of the optional component include a binder and a surfactant.

[0908] <Composition and physical properties of the organic layer-forming composition>

[0909] The content of each component in the organic layer forming composition is determined from the viewpoints of good solubility, storage stability and film-forming properties of each component in the organic layer forming composition, high-quality film quality of the coating obtained from the organic layer forming composition, good ejection properties when using an inkjet method, and good electrical properties, luminescent properties, efficiency and life of an organic EL element having an organic layer made using the composition.

[0910] The composition for forming an organic layer can be prepared by appropriately selecting the components and stirring, mixing, heating, cooling, dissolving, dispersing, etc. by known methods. In addition, filtering, degassing (also called degassing), ion exchange treatment, and inert gas replacement / sealing treatment can also be appropriately selected after preparation.

[0911] 2-1-9. Application examples of organic electroluminescent elements

[0912] The present invention can also be applied to a display device including an organic EL element, a lighting device including an organic EL element, or the like.

[0913] A display device or lighting device including an organic EL element can be manufactured by a known method such as connecting the organic EL element of this embodiment to a known driving device, and can be driven using a known driving method such as DC driving, pulse driving, AC driving, etc. as appropriate.

[0914] As display devices, for example, panel displays such as color flat panel displays, flexible displays such as flexible color organic electroluminescent (EL) displays, etc. (for example, refer to Japanese Patent Laid-Open No. 10-335066, Japanese Patent Laid-Open No. 2003-321546, Japanese Patent Laid-Open No. 2004-281086, etc.). In addition, as display modes of displays, for example, matrix modes and segment modes can be listed. In addition, matrix display and segment display can coexist in the same panel.

[0915] In a matrix, pixels for display are arranged two-dimensionally in a grid or mosaic shape, etc., so that text or images are displayed by a collection of pixels. The shape or size of a pixel is determined according to the purpose. For example, in the image and text display of personal computers, monitors, and televisions, quadrilateral pixels with a side of less than 300 μm are usually used. In addition, in the case of large displays such as display screens, pixels with a side of mm are used. In the case of monochrome display, it is sufficient to arrange pixels of the same color. In the case of color display, red, green, and blue pixels are displayed in parallel. In the case, typical ones are triangular and stripe types. Moreover, as a driving method of the matrix, it can be either a line-sequential driving method or an active matrix. Line-sequential driving has the advantage of simple structure, but in the case of considering the operating characteristics, active matrix is ​​sometimes more excellent, so the driving method also needs to be used according to the purpose.

[0916] In the segmented method (type), a pattern is formed in a manner to display predetermined information, and the determined area is illuminated. Examples include: time or temperature display in a digital clock or thermometer, operating status display of audio equipment or induction cookers, and panel display of a car.

[0917] As lighting devices, for example, lighting devices such as indoor lighting, backlight sources of liquid crystal display devices, etc. can be listed (for example, refer to Japanese Patent Publication No. 2003-257621, Japanese Patent Publication No. 2003-277741, Japanese Patent Publication No. 2004-119211, etc.). Backlight sources are mainly used to improve the visibility of display devices that do not emit light by themselves, and are used for liquid crystal display devices, clocks, audio devices, automobile panels, display boards, and logos. In particular, as a backlight source for personal computers where thinning is becoming a problem in liquid crystal display devices, if it is considered that the existing methods are difficult to be thinned due to the inclusion of fluorescent lamps or light guide plates, the backlight source using the light-emitting element of this embodiment has the characteristics of being thin and lightweight.

[0918] 2-2. Other organic devices

[0919] The polycyclic aromatic compound of the present invention can be used not only in the organic electroluminescent element, but also in the preparation of organic field effect transistors or organic thin film solar cells.

[0920] An organic field effect transistor is a transistor that uses an electric field generated by voltage input to control current. In addition to a source electrode and a drain electrode, a gate electrode is also provided. An organic field effect transistor is a transistor in which an electric field is generated when a voltage is applied to the gate electrode, 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 easy to miniaturize and is often used as a component constituting an integrated circuit, etc.

[0921] Regarding the structure of an organic field effect transistor, generally, a source electrode and a drain electrode are provided in contact with an organic semiconductor active layer formed using the polycyclic aromatic compound of the present invention, and a gate electrode is provided via an insulating layer (dielectric layer) in contact with the organic semiconductor active layer. As an example of its element structure, the following structure can be cited.

[0922] (1) Substrate / gate electrode / insulator layer / source electrode, drain electrode / organic semiconductor active layer

[0923] (2) Substrate / gate electrode / insulator layer / organic semiconductor active layer / source electrode, drain electrode

[0924] (3) Substrate / organic semiconductor active layer / source electrode, drain electrode / insulator layer / gate electrode

[0925] (4) Substrate / source electrode, drain electrode / organic semiconductor active layer / insulator layer / gate electrode

[0926] The organic field effect transistor configured in this way can be used as a pixel driving switch element of an active matrix driving liquid crystal display or an organic electroluminescent display, etc.

[0927] Organic thin film solar cells have a structure in which an anode, a hole transport layer, a photoelectric conversion layer, an electron transport layer, and a cathode of ITO or the like are stacked 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. The polycyclic aromatic compounds of the present invention can be used as materials for hole transport layers, p-type semiconductor layers, n-type semiconductor layers, and electron transport layers according to their physical properties. In organic thin film solar cells, the polycyclic aromatic compounds of the present invention can function as hole transport materials or electron transport materials. In addition to the above layers, organic thin film solar cells may also appropriately include a hole blocking layer, an electron blocking layer, an electron injection layer, a hole injection layer, a smoothing layer, and the like. In organic thin film solar cells, known materials used for organic thin film solar cells can be appropriately selected for use in combination.

[0928] 3. Wavelength conversion materials

[0929] The polycyclic aromatic compound of the present invention can be used as a wavelength conversion material. Currently, the application of multicolorization technology based on color conversion to liquid crystal displays or organic EL displays, lighting, etc. is being actively studied. The so-called color conversion is to convert the light emitted from the light source into light with a longer wavelength, for example, ultraviolet light or blue light is converted into green light or red light. The wavelength conversion material having the color conversion function is filmed, for example, combined with a blue light source, thereby being able to extract the three primary colors of blue, green, and red from the blue light source, that is, to extract white light. This white light source formed by combining the blue light source with the wavelength conversion film having the color conversion function is used as a light source unit, and combined with a liquid crystal drive part and a color filter, thereby being able to produce a full-color display. In addition, if there is no liquid crystal drive part, it can be directly used as a white light source, for example, it can be used as a white light source for light-emitting diode (LED) lighting, etc. In addition, a blue organic EL element is used as a light source, and is used in combination with a wavelength conversion film that converts blue light into green light and red light, thereby being able to produce 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, a low-cost full-color micro LED display can be produced.

[0930] The polycyclic aromatic compound of the present invention can be used as the wavelength conversion material. The 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 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 (a display device or a liquid crystal display device using an organic EL element). The adjustment of the converted color can be carried out by appropriately selecting the substituent of the polycyclic aromatic compound of the present invention, the binder resin used in the wavelength conversion composition described later, etc. The wavelength conversion material is prepared as a wavelength conversion composition containing the polycyclic aromatic compound of the present invention. In addition, the wavelength conversion composition can also be used to form a wavelength conversion film.

[0931] The wavelength conversion composition may contain a binder resin, other additives, and a solvent in addition to the polycyclic aromatic compound of the present invention. As the binder resin, for example, the resins described in paragraphs 0173 to 0176 of International Publication No. 2016 / 190283 may be used. As other additives, the compounds described in paragraphs 0177 to 0181 of International Publication No. 2016 / 190283 may be used. As the solvent, the description of the solvent contained in the light-emitting layer forming composition may be referred to.

[0932] The wavelength conversion film includes a wavelength conversion layer formed by curing the wavelength conversion composition. As a method for making a wavelength conversion layer from a wavelength conversion composition, reference can be made to a known film formation method. The wavelength conversion film may include only a wavelength conversion layer formed by a composition comprising a polycyclic aromatic compound of the present invention, or may 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.

[0933] [Example]

[0934] Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples.

[0935] <<Synthesis example>>

[0936] Synthesis Example (1): Synthesis of Compound (1-1)

[0937] [Chemistry 159]

[0938]

[0939] Under nitrogen atmosphere, 1.6M tert-butyl lithium pentane solution (1.6 ml) was added to a flask containing compound (S-1-1) (1.1 g) and tert-butylbenzene (7.0 ml) at -30°C. After the addition was completed, the temperature was raised to 60°C and stirred for 2 hours, and the components with a boiling point lower than that of tert-butylbenzene were distilled off under reduced pressure. The mixture was cooled to -30°C and added with boron tribromide (0.63 g), and the temperature was raised to room temperature and stirred for 0.5 hours. Thereafter, the mixture was cooled to 0°C again and N,N-diisopropylethylamine (0.43 ml) was added, and the mixture was stirred at room temperature until the heat 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, and an aqueous sodium acetate solution cooled in an ice bath was added, followed by heptane for separation. After purification using a silica gel short-path column (eluent: toluene), the solvent was distilled off under reduced pressure, and the obtained solid was dissolved in toluene, and heptane was added to cause reprecipitation, thereby obtaining compound (1-1) (0.36 g).

[0940] Synthesis Example (2): Synthesis of Compound (2-1)

[0941] [Chemistry 160]

[0942]

[0943] Under nitrogen atmosphere, 1.6M tert-butyl lithium pentane solution (3.2 ml) was added to a flask containing compound (S-2-1) (1.4 g) and tert-butylbenzene (14 ml) at -30°C. After the addition was completed, the temperature was raised to 60°C and stirred for 2 hours, and the components with a boiling point lower than that of tert-butylbenzene were distilled off under reduced pressure. The mixture was cooled to -30°C and added with boron tribromide (1.3 g), and the temperature was raised to room temperature and stirred for 0.5 hours. Thereafter, the mixture was cooled to 0°C again and N,N-diisopropylethylamine (0.86 ml) was added, and the mixture was stirred at room temperature until the heat 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, and an aqueous sodium acetate solution cooled in an ice bath was added, followed by heptane for separation. After purification using a silica gel short-path column (eluent: toluene), the solvent was distilled off under reduced pressure, and the obtained solid was dissolved in toluene, and heptane was added to cause reprecipitation, thereby obtaining compound (2-1) (0.42 g).

[0944] The following compounds were synthesized by the method according to Synthesis Example (1).

[0945] [Chemistry 161]

[0946]

[0947] [Chemistry 162]

[0948]

[0949] [Chemistry 163]

[0950]

[0951] [Chemistry 164]

[0952]

[0953] The following compounds were synthesized by the method according to Synthesis Example (2).

[0954] [Chemistry 165]

[0955]

[0956] [Chemistry 166]

[0957]

[0958] The formation of the target product was confirmed by matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS).

[0959] [Table 1]

[0960] Compound M+ Compound (1-1) 1050.58 Compound (1-2) 1268.57 Compound (1-3) 1400.66 Compound (1-4) 1750.75 Compound (1-5) 1106.55 Compound (1-6) 1215.54 Compound (1-7) 1090.57 Compound (1-8) 1199.57 Compound (1-9) 1492.82 Compound (1-10) 1504.89 Compound (1-11) 1604.94 Compound (1-12) 1717.07 Compound (1-13) 1644.88 Compound (1-14) 1452.88 Compound (1-15) 1511.94 Compound (1-16) 1493.81 Compound (1-17) 1604.94 Compound (1-18) 1644.88 Compound (1-19) 1048.56 Compound (1-20) 1046.55 Compound (1-21) 1192.54 Compound (1-22) 1466.59 Compound (2-1) 1335.53 Compound (2-2) 1487.60 Compound (2-3) 1276.46 Compound (2-4) 1260.49 Compound (2-5) 1391.51 Compound (2-6) 1574.61 Compound (2-7) 1570.58 Compound (2-8) 1110.37 Compound (2-9) 1386.69 Compound (2-10) 1238.58 Compound (2-11) 1487.60 Compound (2-12) 1201.42 Compound (2-13) 1570.58 Compound (2-14) 1570.58 Compound (2-15) 1367.51 Compound (2-16) 1697.62

[0961] The following comparative compounds were synthesized according to the method described in International Publication No. 2019 / 009052, Japanese Patent Application Laid-Open No. 2020-136675, or International Publication No. 2018 / 212169.

[0962] [Chemistry 167]

[0963]

[0964] [Chemistry 168]

[0965]

[0966] <<Manufacturing and evaluation of organic EL elements>>

[0967] Using the synthesized compounds of the present invention and comparative compounds, organic EL devices of TTF, TADF, TAF, and PSF were produced.

[0968] <TTF structure: Example 1-1-1 to Example 1-1-22 and Comparative Example 1-1-1 to Comparative Example 1-1-5>

[0969] ITO (120 nm) / HI (40 nm) / HAT-CN (5 nm) / HT-1 (45 nm) / HT-2 (10 nm) / BH: each compound listed in Table 2 (97: 3) (25 nm) / ET-1 (5 nm) / ET-2: Liq (1: 1) (25 nm) / LiF (1 nm) / Al (100 nm)

[0970] The chemical structures of the compounds used in the production of the element are shown below.

[0971] [Chemistry 169]

[0972]

[0973] A 26 mm × 28 mm × 0.7 mm glass substrate (manufactured by Opto Science Co., Ltd.) on which ITO film having a thickness of 180 nm formed by sputtering was polished to 120 nm was used as a transparent support substrate. The transparent support substrate was fixed on a substrate holder of a commercially available vapor deposition apparatus (manufactured by Showa Vacuum Co., Ltd.), and a molybdenum vapor deposition boat containing HI, HAT-CN, HT-1, HT-2, BH, each compound described in Table 2, ET-1 and ET-2, and an aluminum nitride vapor deposition boat containing Liq, LiF and aluminum were installed.

[0974] The following layers were formed in sequence on the ITO film of the transparent supporting substrate. The vacuum chamber was depressurized to 5×10 -4 Pa, first, HI is heated and evaporated in a manner to make the film thickness 40nm, then HAT-CN is heated and evaporated in a manner to make the film thickness 5nm, then HT-1 is heated and evaporated in a manner to make the film thickness 45nm, then HT-2 is heated and evaporated in a manner to make the film thickness 10nm, to form a hole layer containing four layers. Then, BH and each compound described in Table 2 are heated simultaneously, and evaporated in a manner to make the film thickness 25nm to form a light-emitting layer. The evaporation speed is adjusted in a manner such that the mass ratio of BH to each compound described in Table 2 is approximately 97 to 3. Furthermore, ET-1 is heated and evaporated in a manner to make the film thickness 5nm, then ET-2 and Liq are heated simultaneously, and evaporated in a manner to make the film thickness 25nm to form an electronic layer containing two layers. The evaporation speed is adjusted in a manner such that the mass ratio of ET-2 to Liq is approximately 50 to 50. The deposition rate of each layer is 0.01 nm / sec to 1 nm / sec. Thereafter, LiF is heated and vapor-deposited at a deposition rate of 0.01 nm / sec to 0.1 nm / sec so as to have a film thickness of 1 nm, and then aluminum is heated and vapor-deposited so as to have a film thickness of 100 nm to form a cathode, thereby obtaining an organic EL element.

[0975] <TADF structure: Example 2-2-1 to Example 2-2-16 and Comparative Example 2-2-1 to Comparative Example 2-2-11>

[0976] ITO (50nm) / HAT-CN (10nm) / HT-1 (60nm) / SiCzCz (5nm) / SiCzCz:SiTrzCz2:Compounds listed in Table 2 (60:39:1) (35nm) / mSiTrz (5nm) / mSiTrz:Liq (1:1) (30nm) / LiF (1nm) / Al (100nm)

[0977] A glass substrate of 26 mm × 28 mm × 0.7 mm (manufactured by Opto Science Co., Ltd.) on which ITO film having a thickness of 200 nm was formed by sputtering and polished to 50 nm was used as a transparent support substrate. The transparent support substrate was fixed on a substrate holder of a commercially available vapor deposition apparatus (manufactured by Showa Vacuum Co., Ltd.), and a molybdenum vapor deposition boat containing HAT-CN, HT-1, SiCzCz, SiTrzCz2, the compounds described in Table 2, mSiTrz and Liq, and a tungsten vapor deposition boat containing LiF and aluminum, respectively, were installed.

[0978] The following layers were formed in sequence on the ITO film of the transparent supporting substrate. The vacuum chamber was depressurized to 5×10 -4 Pa, first, HAT-CN is heated and evaporated in a manner that the film thickness becomes 10nm to form a hole injection layer. Then, HT-1 is heated and evaporated in a manner that the film thickness becomes 60nm to form a hole transport layer 1, and then SiCzCz is heated and evaporated in a manner that the film thickness becomes 5nm to form a hole transport layer 2. Next, SiCzCz, SiTrzCz2 and each compound recorded in Table 2 are heated simultaneously, and evaporated in a manner that the film thickness becomes 35nm to form a light-emitting layer. The evaporation speed is adjusted in a manner that the mass ratio of SiCzCz, SiTrzCz2 and each compound recorded in Table 2 becomes approximately 60 to 39 to 1. Next, mSiTrz is heated and evaporated in a manner that the film thickness becomes 5nm to form an electron transport layer 1, and then mSiTrz and Liq are heated and evaporated in a manner that the film thickness becomes 30nm to form an electron transport layer 2. The evaporation rate is adjusted so that the mass ratio of SiTrz to Liq is approximately 1 to 1. The evaporation rate of each layer is 0.01nm / sec to 1nm / sec. Thereafter, LiF is heated and evaporated at a evaporation rate of 0.01nm / sec to 0.1nm / sec so that the film thickness becomes 1nm, and then aluminum is heated and evaporated in a manner so that the film thickness becomes 100nm to form a cathode, thereby obtaining an organic EL element. At this time, the evaporation rate of aluminum is adjusted to 1nm / sec to 10nm / sec. In addition, the SiCzCz of the light-emitting layer is equivalent to a hole-transporting main material, and the SiTrzCz2 is equivalent to an electron-transporting main material.

[0979] <TAF structure: Example 3-1-1 to Example 3-1-22, Comparative Example 3-1-1 to Comparative Example 3-1-5, Example 3-2-1 to Example 3-2-16, and Comparative Example 3-2-1 to Comparative Example 3-2-11>

[0980] ITO (50 nm) / HAT-CN (10 nm) / HT-1 (60 nm) / SiCzCz (5 nm) / SiCzCz: SiTrzCz2: TADF-1: each compound listed in Table 2 (60: 26: 13: 1) (35 nm) / mSiTrz (5 nm) / mSiTrz: Liq (1: 1) (30 nm) / LiF (1 nm) / Al (100 nm)

[0981] Except for the light-emitting layer, the structure was prepared in the same manner as the TADF structure. For the light-emitting layer, SiCzCz, SiTrzCz2, (TADF-1) and the compounds listed in Table 2 were heated simultaneously and evaporated to a film thickness of 35 nm. The evaporation rate was adjusted so that the mass ratio of SiCzCz, SiTrzCz2, (TADF-1) and the compounds listed in Table 2 was approximately 60:26:13:1.

[0982] <PSF structure: Example 4-1-1 to Example 4-1-22, Comparative Example 4-1-1 to Comparative Example 4-1-5, Example 4-2-1 to Example 4-2-16, and Comparative Example 4-2-1 to Comparative Example 4-2-11>

[0983] ITO (50nm) / HAT-CN (10nm) / HT-1 (60nm) / SiCzCz (5nm) / SiCzCz: SiTrzCz2: PtON7: Each compound listed in Table 2 (60:26:13:1) (35nm) / mSiTrz (5nm) / mSiTrz: Liq (1:1) (30nm) / LiF (1nm) / Al (100nm)

[0984] The TAF structure (TADF-1) was replaced with PtON7, and an element was produced in the same manner.

[0985] The chemical structures of the compounds used in the production of the above-mentioned elements are shown below.

[0986] [Chemistry 170]

[0987]

[0988] [evaluate]

[0989] Evaluation items include driving voltage (V), emission wavelength (nm), Commission Internationale de L'Eclairage (CIE) chromaticity (x, y), external quantum efficiency (%), maximum wavelength (nm) and half-value width (nm) of emission spectrum. These evaluation items can be measured using, for example, 1000 cd / m2 The value when emitting light.

[0990] The quantum efficiency of a light-emitting element includes internal quantum efficiency and external quantum efficiency. The internal quantum efficiency indicates the proportion of external energy injected into the light-emitting layer of the light-emitting element as electrons (or holes) 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 element. A portion of the photons generated in the light-emitting layer are absorbed by the inside of the light-emitting element or continuously reflected without being released to the outside of the light-emitting element, so the external quantum efficiency is lower than the internal quantum efficiency.

[0991] The spectral radiance (luminescence spectrum) and external quantum efficiency were measured as follows. A voltage / current generator R6144 manufactured by Advantest was used to apply a voltage so that the device brightness reached 1000 cd / m 2 The element emits light by applying a voltage of . Using a spectroradiometer SR-3AR manufactured by TOPCON, the spectral radiance brightness in the visible light region is measured from a direction perpendicular to the light-emitting surface. Assuming that the light-emitting surface is a completely diffuse surface, the value of the spectral radiance brightness of each wavelength component measured is divided by the wavelength energy and multiplied by π to obtain the number of photons at each wavelength. Then, the number of photons is accumulated in the observed full wavelength region and set as the total number of photons released from the element. The value obtained by dividing the applied current value by the elementary charge is set as the number of carriers injected into the element, and the value obtained by dividing the total number of photons released from the element by the number of carriers injected into the element is the external quantum efficiency. In addition, the half-value width of the luminescence spectrum is calculated as the width between the upper and lower wavelengths where the maximum luminescence wavelength is set as the center and its intensity becomes 50%.

[0992] The ITO electrode was used as the anode and the LiF / aluminum electrode was used as the cathode. A DC voltage was applied and the 1000 cd / m 2 Characteristics during light emission. In addition, for the TTF structure element, the time (lifetime) to maintain a brightness of more than 95% of the initial brightness is measured, and for the TADF structure, TAF structure and PSF structure elements, the time (lifetime) to maintain a brightness of more than 50% of the initial brightness is measured. In addition, the light emission peaks of the elements are all in the range of 450nm to 470nm.

[0993] The results are shown in Table 2.

[0994] [Table 2]

[0995]

[0996]

[0997]

[0998]

[0999] The obtained results show that the element of the embodiment has higher efficiency and longer life than the element of the comparative example having a corresponding skeleton.

Claims

1. A polycyclic aromatic compound having a structure consisting of one or more structural units represented by formula (1); In formula (1), Ring A, Ring B and Ring C are each independently a substituted or unsubstituted aryl ring or a substituted or unsubstituted heteroaryl ring, X is independently >NR NX 、>O、>C(-R CX )2、>Si(-R IX )2.>S or>Se, R NX , R CX and R IX 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 Can bond to each other to form a ring, two R IX Can bond with each other to form a ring, R NX , R CX and R IX can be connected to the R NX , the R CX or the R IX One or two bonds of the ring to which X is bonded, in, The structure contains at least one group represented by formula (X) as a substituent of the aryl ring or the heteroaryl ring in the A ring, the B ring or the C ring, or R NX , R CX or R IX , In formula (X), The position of the wavy line indicates the bonding position of the group represented by formula (X). The P ring and the Q ring are each independently a substituted or unsubstituted aryl ring or a substituted or unsubstituted heteroaryl ring, Z X For -C(-R ZX )=or-N=,R ZX is hydrogen or a substituent, R N is a substituent, L X is a single bond or a divalent linking group, At least one of the aryl rings and heteroaryl rings in the structure 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 the structure, at least one hydrogen may be replaced by deuterium, and at least one nitrogen may be replaced by nitrogen-15( 15 N) substituted, at least one sulfur may be replaced by sulfur-33( 33 S), sulfur-34 ( 34 S) or sulfur-36( 36 S), at least one oxygen may be replaced by oxygen-17( 17 O) or oxygen-18 ( 18 O) substituted, at least one carbon may be substituted by carbon-13 ( 13 C) substituted, at least one boron may be substituted by boron-11( 11 B) Replacement.

2. The polycyclic aromatic compound according to claim 1, wherein Formula (X) is represented by formula (X-1); In formula (X-1), Z X , R N and L X and Z in formula (X) X , R N and L X They have the same meaning respectively. Z are each independently -C(-R Z )=or-N=,R Z is hydrogen or a substituent.

3. The polycyclic aromatic compound according to claim 2, wherein Z is -C(-R Z )=, L X is a single bond, a substituted or unsubstituted phenylene group, or a substituted or unsubstituted biphenylene group.

4. The polycyclic aromatic compound according to claim 3, wherein Formula (X) is represented by formula (X-2), 5. The polycyclic aromatic compound according to claim 4, wherein R N It is a substituent having 6 to 26 atoms excluding hydrogen.

6. The polycyclic aromatic compound according to claim 1, which is represented by formula (1X1) or formula (1X2-1); In formula (1X1) and formula (1X2-1), Ring A, Ring B and Ring C have the same meanings as Ring A, Ring B and Ring C in Formula (1), respectively. X has the same meaning as X in formula (1), Z C are independently -C(-R C )=or=N-,R C are independently hydrogen or a substituent, At least one of the group consisting of the aryl ring and the heteroaryl ring selected from the free formula (1X1) and the formula (1X2-1) 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 each of formula (1X1) and formula (1X2-1), at least one hydrogen may be substituted by deuterium, and at least one nitrogen may be substituted by nitrogen-15( 15 N) substituted, at least one sulfur may be replaced by sulfur-33( 33 S), sulfur-34 ( 34 S) or sulfur-36( 36 S), at least one oxygen may be replaced by oxygen-17( 17 O) or oxygen-18 ( 18 O) substituted, at least one carbon may be substituted by carbon-13 ( 13 C) substituted, at least one boron may be substituted by boron-11( 11 B) Replacement. The polycyclic aromatic compound according to claim 6 , which is represented by the formula (1X1).

8. The polycyclic aromatic compound according to claim 7, which is represented by any of the following formulas; In the formula, Me is methyl, tBu is tert-butyl, and D is deuterium. 9 . The polycyclic aromatic compound according to claim 6 , which is represented by the formula (1X2-1).

10. The polycyclic aromatic compound according to claim 9, which is represented by any of the following formulas; In the formula, tBu is tert-butyl. 11 . An organic electroluminescent element comprising: a pair of electrodes including an anode and a cathode; and an organic layer disposed between the pair of electrodes, wherein the organic layer contains the polycyclic aromatic compound according to claim 1 .

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

13. The organic electroluminescent element according to claim 12, wherein: The light-emitting layer includes at least one selected from the group consisting of an auxiliary dopant and a phosphorescent material.

14. A display device or a lighting device, comprising the organic electroluminescent element according to claim 11.

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