Polycyclic aromatic compounds

Abstract

To provide a novel compound useful as a material for organic devices such as an organic electroluminescent device.SOLUTION: A polycyclic aromatic compound has a structure comprising a structural unit represented by the formula (1A) or the formula (1B) (Z is N or C-RZ, and RZ is H or a substituent; X is >O, >N-RXN, >S or the like; RXN is an aryl or the like; Y bound to adjacent Y via a single bond is >C(-RY1)2; RY1 is an alkyl or the like; adjacent two RY1 may be bound to each other, forming a ring, and Y bound to adjacent Y via a double bond is N or C-RY2; RY2 is H or a substituent; adjacent two RY2 may be bound to each other, forming a ring).SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a polycyclic aromatic compound. In particular, the present invention relates to a polycyclic aromatic compound containing nitrogen and boron. The present invention also relates to a material for an organic device, an organic electroluminescent element, a display device, and a lighting device, each containing the polycyclic aromatic compound. [Background technology]

[0002] In the past, display devices using electroluminescent light-emitting elements have been extensively studied because they can be made thinner and more energy-efficient, and organic electroluminescent devices made from organic materials have been actively studied because they can be easily made lighter and larger. In particular, there has been active research into the development of organic materials that have the ability to emit light such as blue, one of the three primary colors of light, and organic materials that have the ability to transport charges such as holes and electrons (potentially becoming semiconductors or superconductors), regardless of whether they are polymer compounds or low-molecular-weight compounds.

[0003] An organic electroluminescent device has a structure consisting of a pair of electrodes consisting of an anode and a cathode, and one or more layers containing organic compounds disposed between the pair of electrodes. The layers containing organic compounds include a light-emitting layer and a charge transport / injection layer that transports or injects charges such as holes and electrons, and various organic materials suitable for these layers have been developed.

[0004] Among them, Patent Document 1 discloses that a boron-containing polycyclic aromatic compound is useful as a material for organic electroluminescent devices, etc. It has been reported that the organic electroluminescent device containing this polycyclic aromatic compound has good external quantum efficiency. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] International Publication No. 2015 / 102118 Summary of the Invention [Problem to be solved by the invention]

[0006] As mentioned above, various materials have been developed for use in organic EL devices. However, in order to increase the options for materials for organic EL devices, it is desirable to develop materials made of compounds that are different from conventional ones. An object of the present invention is to provide a novel compound useful as a material for organic devices such as organic EL devices. [Means for solving the problem]

[0007] The present inventors conducted extensive research to solve the above-mentioned problems and succeeded in producing a novel polycyclic aromatic compound that has superior light-emitting properties, similar to the compound described in Patent Document 1, among polycyclic aromatic compounds containing boron in its structure. Furthermore, they discovered that an excellent organic EL device can be obtained by constructing an organic EL device by disposing a layer containing this polycyclic aromatic compound between a pair of electrodes, thereby completing the present invention. Specifically, the present invention provides the following polycyclic aromatic compounds, as well as materials for organic devices containing the following polycyclic aromatic compounds.

[0008] <1> A polycyclic aromatic compound having a structure containing a structural unit represented by the following formula (1A) or formula (1B): [ka]

[0009] In formula (1A) and formula (1B), Each Z is independently N or CR Z and R Z are each independently hydrogen or a substituent; Two adjacent R Z may be bonded to each other to form a substituted or unsubstituted aryl ring or a substituted or unsubstituted heteroaryl ring together with ring a, ring b or ring c, X is >O, >NR XN ,>C(-R XC )2, >Si(-R XI)2, >S, or >Se, and R XN is hydrogen, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted alkyl, or substituted or unsubstituted cycloalkyl; R XC and R XI are each independently hydrogen, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted alkyl, or substituted or unsubstituted cycloalkyl; XC may be bonded to each other to form a ring, and two R XI may be bonded to each other to form a ring, and R XN , R XC , R XI may each be bonded to at least one of Z's adjacent to the carbon atom to which X is bonded by a linking group or a single bond; The bonds between two adjacent Ys are each independently a single bond or a double bond, Each Y bonded to an adjacent Y by a single bond is independently >C(-R Y1 )2 and R Y1 are each independently hydrogen, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted alkyl, or substituted or unsubstituted cycloalkyl, and two R Y1 may be bonded to each other to form a ring, and two adjacent R Y1 may be bonded to each other to form a ring, The Y bonded to the adjacent Y via a double bond is N or CR Y2 and R Y2 is hydrogen or a substituent, and two adjacent R Y2 may be bonded to each other to form a ring, provided that two adjacent R Y2 do not bond to each other to form a benzene ring, Y and Z may further be bonded to each other to form a ring consisting of YNCZ or a ring consisting of YCZ, In the structure, at least one of the aryl or heteroaryl rings may be fused with at least one cycloalkane, and the cycloalkane may have at least one substituent, and at least one -CH2- in the cycloalkane may be replaced with -O-; At least one hydrogen in the structure may be replaced with cyano, halogen, or deuterium.

[0010] <2> Both Z are CR Z and R Z are each independently hydrogen, any substituent selected from the substituent group Z, or a substituent represented by formula (A30), R Y2 are each independently hydrogen, a substituent selected from the substituent group Z, or a substituent represented by formula (A30). <1> the polycyclic aromatic compound according to [ka]

[0011] In formula (A30), Ak is hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted cycloalkyl, or substituted or unsubstituted cycloalkenyl, in which at least one -CH2- may be replaced by -O- or -S-; 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 may be bonded to Ak via a single bond or a linking group, * represents the bonding position, The substituent group Z is an aryl optionally substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl, and cycloalkyl; heteroaryl optionally substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl, and cycloalkyl; diarylamino optionally substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl, and cycloalkyl (two aryls may be bonded to each other via a linking group); diheteroarylamino optionally substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl, and cycloalkyl (two heteroaryls may be bonded to each other via a linking group); arylheteroarylamino optionally substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl, and cycloalkyl (the aryl and heteroaryl may be bonded to each other via a linking group); diarylboryl optionally substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl, and cycloalkyl (two aryls may be bonded via a single bond or a linking group); alkyl optionally substituted with at least one group selected from the group consisting of aryl, heteroaryl, and cycloalkyl; cycloalkyl optionally substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl, and cycloalkyl; alkoxy optionally substituted with at least one group selected from the group consisting of aryl, heteroaryl and cycloalkyl; aryloxy optionally substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl, and cycloalkyl; and It consists of substituted silyl.

[0012] <3> R at the para position of B in each of the a, b, and c rings Z is hydrogen, any substituent selected from the substituent group Z or a substituent represented by formula (A30), and other R Zis hydrogen <2> The polycyclic aromatic compound according to claim 1. <4> X is >O, >NR XN ,>C(-R XC )2, or >S, R XN is a substituted or unsubstituted phenyl, and R XC are all methyl <1> ~ <3> 1. The polycyclic aromatic compound according to any one of claims 1 to 9.

[0013] <5> The bonds between two adjacent Ys are both single bonds. <1> ~ <4> 1. The polycyclic aromatic compound according to any one of claims 1 to 9.

[0014] <6> Represented by one of the following formulas <5> the polycyclic aromatic compound according to [ka] In the formulas, Me is methyl, the aryl ring may have, as a substituent, alkyl having 1 to 4 carbon atoms or phenyl optionally substituted with alkyl having 1 to 4 carbon atoms, and at least one hydrogen atom in the structure represented by each formula may be replaced with deuterium. <7> The bonds between two adjacent Ys are both double bonds. <1> ~ <4> 1. The polycyclic aromatic compound according to any one of claims 1 to 9.

[0015] <8> Represented by one of the following formulas <7> the polycyclic aromatic compound according to [ka] In the formulas, Me is methyl, the aryl ring may have, as a substituent, alkyl having 1 to 4 carbon atoms or phenyl optionally substituted with alkyl having 1 to 4 carbon atoms, and at least one hydrogen atom in the structure represented by each formula may be replaced with deuterium.

[0016] <9> <1> ~ <8> 10. A material for an organic device, comprising the polycyclic aromatic compound according to any one of claims 1 to 9. <10> The organic layer is provided between a pair of electrodes consisting of an anode and a cathode, and the organic layer is <1> ~ <8> 10. An organic electroluminescent device comprising the polycyclic aromatic compound according to any one of claims 1 to 9. <11> the organic layer is an emitting layer; <10> The organic electroluminescent device according to claim 1. <12> <10> or <11> A display device or a lighting device comprising the organic electroluminescent device according to claim 1. [Effects of the Invention]

[0017] The present invention provides a novel polycyclic aromatic compound useful as a material for organic devices such as organic electroluminescent elements. The polycyclic aromatic compound of the present invention can be used in the production of organic devices such as organic electroluminescent elements. [Brief explanation of the drawings]

[0018] [Figure 1] 1 is a schematic cross-sectional view showing an example of an organic electroluminescent device. [Figure 2] FIG. 1 is an energy level diagram showing the energy relationship among the host, assisting dopant, and emitting dopant of a TAF element using a common fluorescent dopant. [Figure 3] 1 is an energy level diagram showing an example of the energy relationship between a host, an assisting dopant, and an emitting dopant in an organic electroluminescent element according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0019] The present invention will be described in detail below. The following explanation of the constituent elements may be based on representative embodiments or specific examples, but the present invention is not limited to such embodiments. In this specification, a numerical range expressed using "to" means a range that includes the numerical values ​​before and after "to" as the lower and upper limits. In addition, in this specification, "hydrogen" in the explanation of structural formulas means "hydrogen atom (H)". Similarly, "carbon atom (C)" may be referred to as "carbon". In this specification, the term "adjacent groups" refers to two groups bonded to two adjacent atoms (two atoms directly bonded by a covalent bond) in a structural formula.

[0020] In this specification, "Me" represents methyl, "Et" represents ethyl, "nBu" represents n-butyl (normal butyl), "tBu" represents t-butyl (tertiary butyl), "iBu" represents isobutyl, "secBu" represents secondary butyl, "nPr" represents n-propyl (normal propyl), "iPr" represents isopropyl, "tAm" represents t-amyl, "2EH" represents 2-ethylhexyl, "tOct" represents t-octyl, "Ad" represents 1-adamantyl, "Ph" represents phenyl, "Mes" represents mesityl (2,4,6-trimethylphenyl), "Tf" represents trifluoromethanesulfonyl, "TMS" represents trimethylsilyl, and "D" represents deuterium. In this specification, the organic electroluminescent device may be referred to as an organic EL device.

[0021] In this specification, chemical structures and substituents are sometimes represented by the number of carbon atoms. However, when a chemical structure is substituted with a substituent or when a substituent is further substituted with a substituent, the number of carbon atoms refers to the number of carbon atoms in each of the chemical structure and the substituent, and does not refer to the total number of carbon atoms in the chemical structure and the substituent, or the total number of carbon atoms in the substituent and the substituent. For example, "substituent B of carbon number Y substituted with substituent A of carbon number X" means that "substituent B of carbon number Y" is substituted with "substituent A of carbon number X," and the carbon number Y is not the total number of carbon atoms in substituents A and B. Also, for example, "substituent B of carbon number Y substituted with substituent A" means that "substituent B of carbon number Y" is substituted with "substituent A (with no carbon number restriction)," and the carbon number Y is not the total number of carbon atoms in substituents A and B.

[0022] <Explanation of rings and substituents> First, the rings and substituents used in this specification will be described in detail below.

[0023] As used herein, "hydrocarbon ring" includes, in addition to the "aryl ring" described below, a cycloalkane ring and a cycloalkene ring. Specific examples of cycloalkane rings include a cyclopentane ring and a cyclohexane ring. Specific examples of cycloalkene rings include a cyclopentene ring, a cyclohexene ring, a 1,3-cyclohexadiene ring, and a 1,4-cyclohexadiene ring.

[0024] As used herein, the term "heterocycle" includes the "heteroaryl ring" described below as well as non-aromatic heterocycles. Examples of non-aromatic heterocycles include a piperidine ring, a piperazine ring, and a morpholine ring.

[0025] As used herein, the "aryl ring" includes, for example, 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.

[0026] Specific examples of the "aryl ring" include a monocyclic benzene ring, a bicyclic bicyclic bicyclic naphthalene ring and an indene ring, a tricyclic terphenyl ring (m-terphenyl, o-terphenyl, p-terphenyl) and a fused tricyclic acenaphthylene ring, a fluorene ring, a phenalene ring, a phenanthrene ring, and an anthracene ring, fused tetracyclic triphenylene ring, a pyrene ring, a naphthacene ring, and a chrysene ring, fused pentacyclic perylene ring and a pentacene ring, etc. Furthermore, the fluorene ring, benzofluorene ring, and indene ring each include a structure in which a fluorene ring, a benzofluorene ring, a cyclopentane ring, etc. are spiro-bonded. The fluorene ring, benzofluorene ring, and indene ring also include rings in which two of the two hydrogen atoms of the methylene in the structure are replaced by alkyl such as methyl as the first substituent described below, resulting in a dimethylfluorene ring, a dimethylbenzofluorene ring, a dimethylindene ring, and the like.

[0027] As used herein, the "heteroaryl ring" includes, for example, a heteroaryl ring having 2 to 30 carbon atoms, preferably a heteroaryl ring having 2 to 25 carbon atoms, more preferably a heteroaryl ring having 2 to 20 carbon atoms, still more preferably a heteroaryl ring having 2 to 15 carbon atoms, and particularly preferably a heteroaryl ring having 2 to 10 carbon atoms. Furthermore, the "heteroaryl ring" includes, for example, a heterocyclic ring containing, as ring-constituting atoms other than carbon, 1 to 5 heteroatoms selected from oxygen, sulfur, and nitrogen.

[0028] 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, 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 naphthyl ring, and the like. Examples include a lysine ring, a purine ring, a pteridine ring, a carbazole ring, an acridine ring, a phenoxathiin ring, a phenoxazine ring, a phenothiazine ring, a phenazine ring, a phenazasiline ring, an indolizine ring, a furan ring, a benzofuran ring, an isobenzofuran ring, a dibenzofuran ring, a thiophene ring, a benzothiophene ring, a dibenzothiophene ring, a furazan ring, a thianthrene ring, an indolocarbazole ring, a benzoindolocarbazole ring, a dibenzoindolocarbazole ring, a naphthobenzofuran ring, a dioxin ring, a dihydroacridine ring, a xanthene ring, a thioxanthene ring, a dibenzodioxin ring, etc. Furthermore, dihydroacridine rings, xanthene rings, and thioxanthene rings are also preferred in which two of the two hydrogen atoms of the methylenes in the ring structure are each replaced by an alkyl such as methyl as a first substituent described below, thereby forming a dimethyldihydroacridine ring, a dimethylxanthene ring, a dimethylthioxanthene ring, etc. In addition, bicyclic rings such as bipyridine ring, phenylpyridine ring, and pyridylphenyl ring, and tricyclic rings such as terpyridyl ring, bispyridylphenyl ring, and pyridylbiphenyl ring are also included as "heteroaryl rings." Furthermore, "heteroaryl rings" also include pyran rings.

[0029] In this specification, a substituent may be substituted with an additional 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 additional substituent, or is not substituted. In the same sense, the term "optionally substituted" may also be used. In this specification, the specific substituent may be referred to as a "first substituent," and the additional substituent may be referred to as a "second substituent."

[0030] In the present specification, the substituent group Z is an aryl optionally substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl, and cycloalkyl; heteroaryl optionally substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl, and cycloalkyl; diarylamino optionally substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl, and cycloalkyl (two aryls may be bonded to each other via a linking group); diheteroarylamino optionally substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl, and cycloalkyl (two heteroaryls may be bonded to each other via a linking group); arylheteroarylamino optionally substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl, and cycloalkyl (the aryl and heteroaryl may be bonded to each other via a linking group); diarylboryl optionally substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl, and cycloalkyl (two aryls may be bonded via a single bond or a linking group); alkyl optionally substituted with at least one group selected from the group consisting of aryl, heteroaryl, and cycloalkyl; cycloalkyl optionally substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl, and cycloalkyl; alkoxy optionally substituted with at least one group selected from the group consisting of aryl, heteroaryl and cycloalkyl; aryloxy optionally substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl, and cycloalkyl; and It consists of substituted silyl. The aryl as the second substituent in each group of the substituent group Z may be further substituted with an aryl, heteroaryl, alkyl, or cycloalkyl; similarly, the heteroaryl as the second substituent may be substituted with an aryl, heteroaryl, alkyl, or cycloalkyl.

[0031] In this specification, unless otherwise specified, the term "substituent" may refer to any group selected from substituent group Z. For example, when a "substituted or unsubstituted" group is substituted, the group may be substituted with at least one group selected from substituent group Z.

[0032] In this specification, "aryl" refers to, for example, aryl having 6 to 30 carbon atoms, and preferably aryl having 6 to 20 carbon atoms, aryl having 6 to 16 carbon atoms, aryl having 6 to 12 carbon atoms, or aryl having 6 to 10 carbon atoms.

[0033] Specific examples of "aryl" include phenyl, a monocyclic ring system; biphenylyl (2-biphenylyl, 3-biphenylyl, or 4-biphenylyl), a fused bicyclic ring system, naphthyl (1-naphthyl or 2-naphthyl), a tricyclic ring system, terphenylyl (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), a fused tricyclic ring system, acenaphthylene-(1-, 3-, 4- , or 5-)yl, fluoren-(1-, 2-, 3-, 4-, or 9-)yl, phenalen-(1- or 2-)yl, phenanthrene-(1-, 2-, 3-, 4-, or 9-)yl, or anthracene-(1-, 2-, or 9-)yl, the tetracyclic ring systems quaterphenylyl (5'-phenyl-m-terphenyl-2-yl, 5'-phenyl-m-terphenyl-3-yl, 5'-phenyl-m-terphenyl-4-yl, 5'-phenyl-m-terphenyl-5-yl, 5'-phenyl-m-terphenyl-6-yl, 5'-phenyl-m-terphenyl-7-yl, 5'-phenyl-m-terphenyl-8-yl, 5'-phenyl-m-terphenyl-9-yl, 5'-phenyl-m-terphenyl-10-yl, 5'-phenyl-m-terphenyl-20-yl, 5'-phenyl-m-terphenyl-3-yl, 5'-phenyl-m-terphenyl-11-yl, 5'-phenyl-m-terphenyl-12-yl, 5'-phenyl-m-terphenyl-13-yl, 5'-phenyl-m-terphenyl-14-yl, 5'-phenyl-m-terphenyl-15-yl, 5'-phenyl-m-terphenyl-16-yl, 5'-phenyl-m-terphenyl-17-yl, 5'-phenyl-m-terphenyl-18-yl, 5'-phenyl-m-terphenyl-19-yl, 5'-phenyl-m-terphenyl-21-yl, 5'-phenyl-m-terphenyl-22-yl, 5'-phenyl-m-terphenyl-33-yl, 5'-phenyl-m-terphenyl-19-yl, 5'-phenyl-m-terphenyl-23-yl, 5'-phenyl-m- Examples of fused tetracyclic ring systems include triphenylene-(1- or 2-)yl, pyrene-(1-, 2-, or 4-)yl, or naphthacene-(1-, 2-, or 5-)yl, and fused pentacyclic ring systems include perylene-(1-, 2-, or 3-)yl, or pentacene-(1-, 2-, 5-, or 6-)yl. Other examples include monovalent radicals of spirofluorene.

[0034] The aryl as the second substituent also includes a structure in which the aryl is substituted with at least one group selected from the group consisting of aryl such as phenyl (specific examples are the groups described above), alkyl such as methyl (specific examples are the groups described below), and cycloalkyl such as cyclohexyl or adamantyl (specific examples are the groups described below). An example of such a group is a group in which the 9-position of the fluorenyl as the second substituent is substituted with an aryl such as phenyl, an alkyl such as methyl, or a cycloalkyl such as cyclohexyl or adamantyl.

[0035] The "arylene" is, for example, an arylene having 6 to 30 carbon atoms, and preferably an arylene having 6 to 20 carbon atoms, an arylene having 6 to 16 carbon atoms, an arylene having 6 to 12 carbon atoms, or an arylene having 6 to 10 carbon atoms. Specific examples of "arylene" include divalent groups obtained by removing one hydrogen atom from the above-mentioned "aryl" (monovalent group).

[0036] The "heteroaryl" is, for example, a heteroaryl having 2 to 30 carbon atoms, and preferably a heteroaryl having 2 to 25 carbon atoms, a heteroaryl having 2 to 20 carbon atoms, a heteroaryl having 2 to 15 carbon atoms, or a heteroaryl having 2 to 10 carbon atoms. The "heteroaryl" contains, in addition to carbon, one or more, preferably 1 to 5, heteroatoms selected from oxygen, sulfur, nitrogen, etc. as ring-constituting atoms.

[0037] Specific examples of "heteroaryl" 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, quinolinyl, isoquinolinyl, cinnolinyl, quinazolinyl, quinoxalinyl, phenanthrolinyl, phthalazinyl, naphthyridinyl, purinyl, pteridinyl, carbazolyl, and a Examples of the alkyl radical include clidinyl, phenoxathiinyl, phenoxazinyl, phenothiazinyl, phenazinyl, phenazasilinyl, indolizinyl, furanyl, benzofuranyl, isobenzofuranyl, dibenzofuranyl, naphthobenzofuranyl, thienyl, benzothienyl, isobenzothienyl, dibenzothienyl, naphthobenzothienyl, benzophosphoryl, dibenzophosphoryl, a monovalent group of a benzophosphole oxide ring, a monovalent group of a dibenzophosphole oxide ring, furazanyl, thianthrenyl, indolocarbazolyl, benzoindolocarbazolyl, dibenzoindolocarbazolyl, imidazolinyl, and oxazolinyl. Other examples include a monovalent group of spiro[fluorene-9,9'-xanthene], a monovalent group of spirobi[silafluorene], and a monovalent group of benzoselephene.

[0038] The heteroaryl as the second substituent also includes a structure in which the heteroaryl is substituted with at least one group selected from the group consisting of aryl such as phenyl (specific examples are the groups described above), alkyl such as methyl (specific examples are the groups described below), and cycloalkyl such as cyclohexyl or adamantyl (specific examples are the groups described below). An example of such a group is a carbazolyl group as the second substituent, where the 9-position is substituted with an aryl such as phenyl, an alkyl such as methyl, or a cycloalkyl such as cyclohexyl or adamantyl. Also included in the heteroaryl group as the second substituent are groups in which a nitrogen-containing heteroaryl such as pyridyl, pyrimidinyl, triazinyl, or carbazolyl is further substituted with phenyl or biphenylyl.

[0039] The "heteroarylene" is, for example, a heteroarylene having 2 to 30 carbon atoms, and preferably a heteroarylene having 2 to 25 carbon atoms, a heteroarylene having 2 to 20 carbon atoms, a heteroarylene having 2 to 15 carbon atoms, or a heteroarylene having 2 to 10 carbon atoms. Furthermore, the "heteroarylene" is, for example, a divalent group such as a heterocycle containing, in addition to carbon, 1 to 5 heteroatoms selected from oxygen, sulfur, and nitrogen as ring-constituting atoms. Specific examples of "heteroarylene" include divalent groups obtained by removing one hydrogen atom from the above-mentioned "heteroaryl" (monovalent group).

[0040] "Diarylamino" is an amino substituted with two aryls, and the details of the aryls can be found in the above explanation of "aryl". "Diheteroarylamino" refers to an amino group substituted with two heteroaryls, and the details of this heteroaryl can be found in the above description of "heteroaryl". "Arylheteroarylamino" refers to an amino group substituted with an aryl and a heteroaryl, and the details of the aryl and heteroaryl can be found in the explanations of "aryl" and "heteroaryl" given above.

[0041] The two aryls in the diarylamino as the first substituent may be bonded to each other via a linking group, the two heteroaryls in the diheteroarylamino as the first substituent may be bonded to each other via a linking group, and the aryl and heteroaryl in the arylheteroarylamino as the first substituent may be bonded to each other via a linking group. Here, the expression "bonded via a linking group" means that, for example, the two phenyls in diphenylamino form a bond via a linking group, as shown below. This explanation also applies to diheteroarylamino and arylheteroarylamino formed by aryls or heteroaryls.

[0042] [ka]

[0043] Specific examples of the linking group include >O and >NR X ,>C(-R X )2, >Si(-R X )2, >S, >CO, >CS, >SO, >SO2, and >Se. X are each independently alkyl, cycloalkyl, aryl, or heteroaryl, which may be substituted with alkyl, cycloalkyl, aryl, or heteroaryl. X )2, >Si(-R X )2, in R X is a single bond or a linking group X Y They may be bonded via X to form a ring. Y As >O, >NR Y ,>C(-R Y )2, >Si(-R Y )2, >S, >CO, >CS, >SO, >SO2, and >Se, and R Y are each independently alkyl, cycloalkyl, aryl, or heteroaryl, which may be substituted with alkyl, cycloalkyl, aryl, or heteroaryl, provided that X Y >C(-R Y )2 and >Si(-RY )2, two R Y do not bond to form a ring. Further examples of the linking group include alkenylene. Any hydrogen atom in the alkenylene can be independently selected from R X and R X are each independently alkyl, cycloalkyl, substituted silyl, aryl, or heteroaryl, which may be substituted with alkyl, cycloalkyl, substituted silyl, or aryl.

[0044] In this specification, unless otherwise specified, when the term "diarylamino," "diheteroarylamino," or "arylheteroarylamino" is simply used, it is assumed that the following additional explanation is added: "two aryls in the diarylamino may be bonded to each other via a linking group," "two heteroaryls in the diheteroarylamino may be bonded to each other via a linking group," and "aryl and heteroaryls in the arylheteroarylamino may be bonded to each other via a linking group," respectively.

[0045] A "diarylboryl" is a boryl substituted with two aryls. For details of the aryl, see the above description of the "aryl." The two aryls may be bonded via a single bond or a linking group (e.g., -CH=CH-, -CR=CR-, -C≡C-, >NR, >O, >S, >C(-R)2, >Si(-R)2, or >Se). Here, the R of -CR=CR-, the R of >NR, the R of >C(-R)2, and the R of >Si(-R)2 are aryl, heteroaryl, diarylamino, alkyl, alkenyl, alkynyl, cycloalkyl, alkoxy, or aryloxy, and at least one hydrogen atom in the R may be further substituted with an aryl, heteroaryl, alkyl, alkenyl, alkynyl, or cycloalkyl. Adjacent Rs may form a ring, forming a cycloalkylene, arylene, or heteroarylene. For details of the substituents listed here, the above-mentioned explanations of "aryl," "arylene," "heteroaryl," "heteroarylene," and "diarylamino," as well as the below-mentioned explanations of "alkyl," "alkenyl," "alkynyl," "cycloalkyl," "cycloalkylene," "alkoxy," and "aryloxy" can be cited. Furthermore, when "diarylboryl" is simply described in this specification, unless otherwise specified, it is assumed that the explanation that "the two aryls of the diarylboryl may be bonded to each other via a single bond or a linking group" is also added.

[0046] The "alkyl" may be either straight-chain or branched-chain, for example, a straight-chain alkyl having 1 to 24 carbon atoms or a branched-chain alkyl having 3 to 24 carbon atoms, and is preferably an alkyl having 1 to 18 carbon atoms (branched-chain alkyl having 3 to 18 carbon atoms), an alkyl having 1 to 12 carbon atoms (branched-chain alkyl having 3 to 12 carbon atoms), an alkyl having 1 to 6 carbon atoms (branched-chain alkyl having 3 to 6 carbon atoms), an alkyl having 1 to 5 carbon atoms (branched-chain alkyl having 3 to 5 carbon atoms), or an alkyl having 1 to 4 carbon atoms (branched-chain alkyl having 3 to 4 carbon atoms).

[0047] 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, s-butyl, t-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-dimethylhexyl Examples of the alkyl group include methylheptyl, 2,6-dimethyl-4-heptyl, n-octyl, t-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, and n-eicosyl.

[0048] An "alkylene" is a divalent group obtained by removing any hydrogen from an "alkyl", such as methylene, ethylene, or propylene.

[0049] For "alkenyl," the explanation of "alkyl" above can be referred to. It is a group in which a C═C single bond in the "alkyl" structure is replaced with a C═C double bond, and also includes groups in which not only one but two or more single bonds are replaced with double bonds (also called alkadiene-yl or alkanetriene-yl).

[0050] "Alkenylene" is a divalent group obtained by removing any hydrogen from "alkenyl", and examples include vinylene.

[0051] For "alkynyl," the explanation of "alkyl" above can be referred to. It is a group in which a C≡C single bond in the "alkyl" structure is replaced with a C≡C triple bond, and also includes groups in which not only one but two or more single bonds are replaced with triple bonds (also called alkadiyn-yl or alkanetriyn-yl).

[0052] The "cycloalkyl" is, for example, a cycloalkyl having 3 to 24 carbon atoms, and preferably a cycloalkyl having 3 to 20 carbon atoms, a cycloalkyl having 3 to 16 carbon atoms, a cycloalkyl having 3 to 14 carbon atoms, a cycloalkyl having 3 to 12 carbon atoms, a cycloalkyl having 5 to 10 carbon atoms, a cycloalkyl having 5 to 8 carbon atoms, a cycloalkyl having 5 to 6 carbon atoms, or a cycloalkyl having 5 carbon atoms.

[0053] Specific examples of "cycloalkyl" include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl, or alkyl (particularly methyl) substituted derivatives thereof having 1 to 5 carbon atoms or 1 to 4 carbon atoms, norbornenyl, 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, bicyclo[2.2.2]octyl, adamantyl, diamantyl, decahydronaphthalenyl, and decahydroazulenyl.

[0054] "Cycloalkylene" is, for example, cycloalkylene having 3 to 24 carbon atoms, and preferably cycloalkylene having 3 to 20 carbon atoms, cycloalkylene having 3 to 16 carbon atoms, cycloalkylene having 3 to 14 carbon atoms, cycloalkylene having 3 to 12 carbon atoms, cycloalkylene having 5 to 10 carbon atoms, cycloalkylene having 5 to 8 carbon atoms, cycloalkylene having 5 to 6 carbon atoms, cycloalkylene having 5 carbon atoms, etc. A specific example of "cycloalkylene" is a structure in which one hydrogen atom is removed from the above-mentioned "cycloalkyl" (monovalent group) to form a divalent group.

[0055] "Cycloalkenyl" refers to a group having a structure in which at least one pair of single bonds between two carbon atoms in the above-mentioned "cycloalkyl" has become a double bond (for example, a group in which -CH-CH- is replaced with -CH=CH-), and does not fall under the category of aryl. Specific examples include 1-cyclohexenyl and 1-cyclopentenyl.

[0056] "Alkoxy" is a group represented by "Alk-O- (Alk is alkyl)", and the above explanation of "alkyl" can be cited for details of the alkyl.

[0057] "Aryloxy" is a group represented by "Ar-O-(Ar is aryl)", and the above explanation of "aryl" can be cited for details of the aryl.

[0058] The "substituted silyl" is, for example, a silyl substituted with at least one of aryl, alkyl, and cycloalkyl, and is preferably triarylsilyl, trialkylsilyl, tricycloalkylsilyl, dialkylcycloalkylsilyl, or alkyldicycloalkylsilyl.

[0059] "Triarylsilyl" is a silyl group substituted with three aryl groups, and the details of the aryl groups can be found in the above description of "aryl." Specific examples of "triarylsilyl" include triphenylsilyl, diphenylmononaphthylsilyl, monophenyldinaphthylsilyl, and trinaphthylsilyl.

[0060] "Trialkylsilyl" is a silyl group substituted with three alkyl groups, and the details of this alkyl can be found in the above explanation of "alkyl". Specific examples of the "trialkylsilyl" include trimethylsilyl, triethylsilyl, tri-n-propylsilyl, triisopropylsilyl, tri-n-butylsilyl, triisobutylsilyl, tri-s-butylsilyl, tri-t-butylsilyl, ethyldimethylsilyl, n-propyldimethylsilyl, isopropyldimethylsilyl, n-butyldimethylsilyl, isobutyldimethylsilyl, s-butyldimethylsilyl, t-butyldimethylsilyl, methyldiethylsilyl, n-propyldiethylsilyl, isopropyldiethylsilyl, n-butyldiethylsilyl, s-butyldiethylsilyl, t-butyldiethylsilyl, methyldi-n-propylsilyl, ethyldi-n-propylsilyl, n-butyldi-n-propylsilyl, s-butyldi-n-propylsilyl, t-butyldi-n-propylsilyl, methyldiisopropylsilyl, ethyldiisopropylsilyl, n-butyldiisopropylsilyl, s-butyldiisopropylsilyl, and t-butyldiisopropylsilyl.

[0061] "Tricycloalkylsilyl" is a silyl group substituted with three cycloalkyl groups, and the details of this cycloalkyl can be found in the above description of "cycloalkyl". Specific "tricycloalkylsilyl" includes, for example, tricyclopentylsilyl or tricyclohexylsilyl.

[0062] "Dialkylcycloalkylsilyl" is a silyl group substituted with two alkyls and one cycloalkyl, and the details of the alkyl and cycloalkyl can be found in the explanations of "alkyl" and "cycloalkyl" above.

[0063] "Alkyldicycloalkylsilyl" is a silyl group substituted with one alkyl and two cycloalkyl, and the details of the alkyl and cycloalkyl can be found in the explanations of "alkyl" and "cycloalkyl" above.

[0064] <When two groups bonded to the same atom are bonded to each other> In the present specification, when it is stated that two groups bonded to the same atom may be bonded to each other to form a ring, they may be bonded by a single bond or a linking group (collectively also referred to as a linking group), and 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-, -Si(-R)2-, or -Se-, for example, the following structure. R of -CHR-CHR-, R of -CR-CR-, R of -CR=CR-, R of -N(-R)-, R of -C(-R)-, and R of -Si(-R)- are each independently hydrogen, aryl optionally substituted with alkyl or cycloalkyl, heteroaryl optionally substituted with alkyl or cycloalkyl, alkyl optionally substituted with cycloalkyl, alkenyl optionally substituted with alkyl or cycloalkyl, alkynyl optionally substituted with alkyl or cycloalkyl, or cycloalkyl optionally substituted with alkyl or cycloalkyl. Two adjacent Rs may form a ring to form a cycloalkylene, arylene, or heteroarylene.

[0065] [ka]

[0066] As the linking group, a single bond and -CR=CR-, -N(-R)-, -O-, -S-, -C(-R)2-, -Si(-R)2-, and -Se- are preferred, a single bond and -CR=CR-, -N(-R)-, -O-, -S-, and -C(-R)2- as linking groups are more preferred, a single bond and -CR=CR-, -N(-R)-, -O-, and -S- as linking groups are even more preferred, and a single bond is most preferred.

[0067] The position at which two Rs are bonded by the bonding group is not particularly limited as long as it is a position where bonding is possible, but it is preferable that they are bonded at the most adjacent positions. For example, when the two groups are phenyl, it is preferable that they are bonded at positions ortho (2nd position) relative to the bonding position (1st position) of "C" or "Si" in the phenyl (see the structural formula above).

[0068] 1. Polycyclic aromatic compounds The polycyclic aromatic compound of the present invention is a polycyclic aromatic compound having a structure containing a structural unit represented by formula (1A) or formula (1B).

[0069] [ka]

[0070] The polycyclic aromatic compound of the present invention has a structure in which all of the peripheries of B (boron) in the skeleton of the polycyclic aromatic compound described in WO 2015 / 102118 are fused rings. This structure increases molecular stability and extends the device life. This structure also enhances the multiple resonance effect of boron (electron-withdrawing) and nitrogen (electron-donating), narrowing the half-width. Furthermore, the additional nitrogen-containing five-membered ring makes the fused ring structure around boron less likely to collapse, increasing molecular stability, adjusting the emission wavelength, and achieving a deep blue color.

[0071] <Ring structures of polycyclic aromatic compounds> The polycyclic aromatic compound of the present invention is a polycyclic aromatic compound having a structure containing a structural unit represented by formula (1A) or formula (1B). The polycyclic aromatic compound having a structure containing a structural unit represented by formula (1A) or formula (1B) includes a polycyclic aromatic compound having a structure consisting of one or more structural units represented by formula (1A) or formula (1B). An example of a polycyclic aromatic compound having a structure consisting of one of the above structural units is a polycyclic aromatic compound represented by formula (1A) or formula (1B). An example of a polycyclic aromatic compound having a structure consisting of two or more structural units represented by formula (1A) or formula (1B) is a compound corresponding to a multimer of the compound represented by formula (1A) or formula (1B). The multimer is preferably a dimer to a hexamer, more preferably a dimer to a trimer, and particularly preferably a dimer. The polymer may have a plurality of the above unit structures in one compound, and may be bonded so that any ring (ring a, ring b, ring c, or ring containing Y) contained in the above structural unit is shared by the plurality of unit structures, or may be bonded so that any ring (ring a, ring b, ring c, or ring containing Y) contained in the above unit structure is fused to each other. Furthermore, the above unit structures may be bonded together by a linking group such as a single bond, alkylene having 1 to 3 carbon atoms, phenylene, or naphthylene. Of these, a bonded structure so that the ring is shared is preferred.

[0072] The polycyclic aromatic compound having a structure containing a structural unit represented by formula (1A) or formula (1B) is preferably a polycyclic aromatic compound (monomer) having a structure represented by formula (1A) or formula (1B).

[0073] In formula (1A) and formula (1B), each Z is independently N or CR Z and R Z are each independently hydrogen or a substituent. Therefore, the ring a, ring b, or ring c (monocyclic) portion can form a benzene ring, a pyridine ring, a pyrimidine ring, or a pyridazine ring, respectively. In addition, when two adjacent R Zmay be bonded to each other to form a substituted or unsubstituted aryl ring or a substituted or unsubstituted heteroaryl ring together with ring a, ring b, or ring c, which may form a fused ring containing a benzene ring, a pyridine ring, a pyrimidine ring, or a pyridazine ring.

[0074] In formula (1A) and formula (1B), the bonds between two adjacent Ys are each independently a single bond or a double bond.

[0075] Each Y bonded to an adjacent Y by a single bond is independently >C(-R Y1 )2 and R Y1 R is independently hydrogen, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted alkyl, or substituted or unsubstituted cycloalkyl. Y1 is preferably an unsubstituted alkyl or an unsubstituted cycloalkyl. Y1 may be bonded to each other to form a ring. Y1 may be bonded to each other to form a ring. Specifically, two adjacent R Y1 may be bonded to each other to form, together with the carbon atoms to which they are bonded, a substituted or unsubstituted hydrocarbon ring (excluding an aryl ring) or a substituted or unsubstituted heterocycle (excluding a heteroaryl ring). For example, the following structures are preferred examples.

[0076] [ka] In the formula, * indicates the bonding position between the nitrogen and the carbon on ring a, ring b, or ring c.

[0077] The Y bonded to the adjacent Y via a double bond is N or CR Y2 and R Y2 is hydrogen or a substituent.

[0078] Two adjacent R Y2 may be bonded to each other to form a ring. Specifically, two adjacent RY2 may be bonded to each other to form a substituted or unsubstituted hydrocarbon ring or a substituted or unsubstituted heterocycle together with the carbon atoms to which they are bonded. Y2 do not bond to each other to form a benzene ring. Y2 The ring formed by bonding together is preferably a pentene ring or a cyclohexene ring. These rings may have a substituent. In particular, it is preferable that the carbon at the α-position relative to the double bond (the carbon at the position adjacent to the carbon bonded by the double bond) has a substituent. The substituent is preferably alkyl, and more preferably methyl. It is preferable that no hydrogen is bonded to the carbon at the α-position.

[0079] In formula (1A) and formula (1B), Y and Z may be bonded to each other to form a ring consisting of YNCZ or a ring consisting of YCZ. That is, Y may be bonded to the Z located closest to it, as indicated by the arrow below.

[0080] [ka]

[0081] Specifically, >C(-R Y1 )2 in Y Y1 is CR Z R in Z is Z and may be bonded to each other, Y2 R in Y Y2 is CR Z R in Z is Z R may be bonded to each other. Y1 and R Y2 are each connected to R by a single bond or a linking group. Z It is sufficient that one of the bonds is a bond (i.e., a hydrogen atom or a hydrogen atom in a substituent acts as a bond). Examples of such structures include compounds represented by formula (1-123) or formula (1-124) described below.

[0082] In formula (1A) and formula (1B), X is >O, >NR XN ,>C(-R XC )2, >Si(-R XI )2, >S, or >Se. X is >O, >NR XN ,>C(-R XC )2 or >S, and >O, >NR XN , or more preferably >S, and >NR XN It is more preferable that:

[0083] R XN R is hydrogen, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted alkyl, or substituted or unsubstituted cycloalkyl, preferably substituted or unsubstituted aryl, more preferably substituted or unsubstituted phenyl, and even more preferably unsubstituted phenyl. XC and R XI are each independently hydrogen, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted alkyl, or substituted or unsubstituted cycloalkyl, and are preferably substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, or unsubstituted alkyl. XC Preferably, all of R are methyl. XI Preferably, both R are methyl. XC may be bonded to each other to form a ring, and two R XI may be bonded to each other to form a ring.

[0084] R XN , R XC and R XI may be bonded to at least one of Z's adjacent to the carbon atom to which X is bonded via a linking group or a single bond. In this case, Z is CR Z and R Z is a bond. And this bond is R XN , R XC and R XIIt is sufficient that any of the hydrogen atoms in the group is replaced by a hydrogen atom. Examples of the linking group include the same examples as those of the linking group when two groups bonded to the same atom are bonded to each other. Among these, -O-, -S-, -C(-Me)2-, -Si(-Me)2-, and 1,2-phenylene are preferred.

[0085] Preferred examples of the structural unit represented by formula (1A) or formula (1B) include structural units represented by formula (1A-a), formula (1A-b), formula (1A-c), formula (1B-a), formula (1B-b) or formula (1B-c).

[0086] [ka]

[0087] In formula (1A-a), formula (1A-b), formula (1A-c), formula (1B-a), formula (1B-b) and formula (1B-c), Z, X, R Y1 , R Y2 respectively represent Z, X, and R in formula (1A) and formula (1B). Y1 , R Y2 are synonymous with each other.

[0088] More preferred examples of the structural unit represented by formula (1A) or formula (1B) include structural units represented by any of the following formulae: Note that all of the following formulae show skeletons excluding substituents, and the skeletons represented by the following formulae may further have substituents.

[0089] [ka]

[0090] [ka]

[0091] <Substituents of Polycyclic Aromatic Compounds> In formula (1A) and formula (1B), each Z is independently N or CRZ and R Z are each independently hydrogen or a substituent. Z The rings formed by bonding together with the ring a, ring b or ring c may have a substituent. In addition, Y bonded to the adjacent Y via a double bond is N or CR Y2 and R Y2 are each independently hydrogen or a substituent. Examples of these substituents and substituents on the aryl ring or heteroaryl ring in formula (1A) and formula (1B) are described below.

[0092] The emission wavelength can be adjusted by the steric hindrance, electron donating property and electron withdrawing property of the substituent structure of the compound used as a dopant (assisting dopant or emitting dopant), such as a polycyclic aromatic compound having a structure containing a structural unit represented by formula (1A) or formula (1B). Preferred are groups represented by the following structural formulas, more preferably methyl, t-butyl, t-amyl, t-octyl, neopentyl, adamantyl, phenyl, o-tolyl, p-tolyl, 2,4-xylyl, 2,5-xylyl, 2,6-xylyl, 2,4,6-mesityl, diphenylamino, di-p-tolylamino, bis(p-(t-butyl)phenyl)amino, carbazolyl, 3,6-dimethylcarbazolyl, 3,6- Di-t-butylcarbazolyl and phenoxy are more preferred, and methyl, t-butyl, t-amyl, t-octyl, neopentyl, adamantyl, phenyl, o-tolyl, 2,6-xylyl, 2,4,6-mesityl, diphenylamino, di-p-tolylamino, bis(p-(t-butyl)phenyl)amino, carbazolyl, 3,6-dimethylcarbazolyl and 3,6-di-t-butylcarbazolyl are more preferred. From the viewpoint of ease of synthesis, a larger steric hindrance is preferred for selective synthesis, and specifically, t-butyl, t-amyl, t-octyl, adamantyl, o-tolyl, p-tolyl, 2,4-xylyl, 2,5-xylyl, 2,6-xylyl, 2,4,6-mesityl, di-p-tolylamino, bis(p-(t-butyl)phenyl)amino, 3,6-dimethylcarbazolyl, and 3,6-di-t-butylcarbazolyl are preferred.

[0093] In the following structural formula, * represents a bond position. [ka]

[0094] [ka]

[0095] [ka]

[0096] [ka]

[0097] [ka]

[0098] [ka]

[0099] [ka]

[0100] [ka]

[0101] [ka]

[0102] [ka]

[0103] [ka]

[0104] [ka]

[0105] [ka]

[0106] When a polycyclic aromatic compound having a structure containing a structural unit represented by formula (1A) or (1B) is used as a dopant (assisting dopant or emitting dopant), or in other compounds used as dopants, a tertiary alkyl represented by the following formula (tR) is particularly preferred as a substituent containing "alkyl" on an aryl or heteroaryl ring in ring a, ring b, ring c, or a ring containing Y. This is because such a bulky substituent increases the intermolecular distance, thereby improving the luminescence quantum yield (PLQY). Also preferred are substituents in which the tertiary alkyl represented by formula (tR) is substituted with another substituent as a second substituent. Specific examples include diarylamino substituted with tertiary alkyl represented by (tR), carbazolyl (preferably N-carbazolyl) substituted with tertiary alkyl represented by (tR), or benzocarbazolyl (preferably N-benzocarbazolyl) substituted with tertiary alkyl represented by (tR). Substitution of the group of formula (tR) on diarylamino, carbazolyl and benzocarbazolyl includes examples in which some or all of the hydrogen atoms on the aryl ring or benzene ring in these groups are substituted with the group of formula (tR).

[0107] [ka]

[0108] In the formula (tR), Ra , R b , and R c are each independently alkyl having 1 to 24 carbon atoms, any —CH2— in the alkyl may be substituted with —O—, and the group represented by formula (tR) is bonded to the substitution site at *.

[0109] R a , R b and R c The "alkyl having 1 to 24 carbon atoms" may be either a straight chain or a branched chain, and examples thereof include a straight chain alkyl having 1 to 24 carbon atoms or a branched chain alkyl having 3 to 24 carbon atoms, an alkyl having 1 to 18 carbon atoms (branched chain alkyl having 3 to 18 carbon atoms), an alkyl having 1 to 12 carbon atoms (branched chain alkyl having 3 to 12 carbon atoms), an alkyl having 1 to 6 carbon atoms (branched chain alkyl having 3 to 6 carbon atoms), and an alkyl having 1 to 4 carbon atoms (branched chain alkyl having 3 to 4 carbon atoms).

[0110] R in formula (tR) a , R b , and R c The total number of carbon atoms is preferably 3 to 20, and particularly preferably 3 to 10.

[0111] R a , R b , and R c Specific examples of alkyl include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, s-butyl, t-butyl, n-pentyl, isopentyl, neopentyl, t-pentyl, n-hexyl, 1-methylpentyl, 4-methyl-2-pentyl, 3,3-dimethylbutyl, 2-ethylbutyl, n-heptyl, 1-methylhexyl, n-octyl, t-octyl, 1-methylheptyl, 2 1-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-eicosyl.

[0112] Examples of the group represented by formula (tR) include t-butyl, t-amyl, 1-ethyl-1-methylpropyl, 1,1-diethylpropyl, 1,1-dimethylbutyl, 1-ethyl-1-methylbutyl, 1,1,3,3-tetramethylbutyl, 1,1,4-trimethylpentyl, 1,1,2-trimethylpropyl, 1,1-dimethyloctyl, 1,1-dimethylpentyl, 1,1-dimethylheptyl, 1,1,5-trimethylhexyl, 1-ethyl- Examples include 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, t-butyl and t-amyl are preferred.

[0113] The polycyclic aromatic compound having a structure containing a structural unit represented by formula (1A) or (1B) preferably has a structure containing at least one tertiary alkyl (such as t-butyl or t-amyl), neopentyl, or adamantyl group represented by the above formula (tR), and preferably contains a tertiary alkyl (such as t-butyl or t-amyl) represented by formula (tR). This is because such bulky substituents increase the intermolecular distance, thereby improving the luminescence quantum yield (PLQY). Diarylamino is also preferred as the substituent. Furthermore, diarylamino substituted with a group represented by formula (tR), carbazolyl (preferably N-carbazolyl) substituted with a group represented by formula (tR), or benzocarbazolyl (preferably N-benzocarbazolyl) substituted with a group represented by formula (tR) are also preferred. Substitution of the group of formula (tR) on diarylamino, carbazolyl and benzocarbazolyl includes examples in which some or all of the hydrogen atoms on the aryl ring or benzene ring in these groups are substituted with the group of formula (tR).

[0114] As the substituent in the polycyclic aromatic compound having a structure containing the structural unit represented by formula (1A) or formula (1B), a substituent represented by formula (A30) is also preferred. [ka]

[0115] In formula (A30), Ak is hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted cycloalkyl, or substituted or unsubstituted cycloalkenyl, in which at least one -CH2- may be replaced by -O- or -S-; 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 may be bonded to Ak via a linking group or a single bond, and * indicates the bonding position.

[0116] In formula (A30), Ak is the above-mentioned substituent, so it does not conjugate with the lone electron pair on N, and therefore the lone electron pair can be conjugated with the π electron to which it is bonded, allowing for a greater wavelength shift than when there is an aryl or the like at the same position. This also has a similar effect on the multiple resonance effect, allowing for a greater improvement in thermally activated delayed fluorescence (TADF) properties.

[0117] R Ak is preferably aryl which may be substituted with alkyl or cycloalkyl, heteroaryl which may be substituted with alkyl or cycloalkyl, alkyl or cycloalkyl, more preferably aryl which may be substituted with alkyl, heteroaryl which may be substituted with alkyl, alkyl or cycloalkyl, still more preferably aryl which may be substituted with alkyl, and particularly preferably phenyl which may be substituted with methyl.

[0118] In formula (A30), Ak is preferably alkyl having 1 to 6 carbon atoms or cycloalkyl having 3 to 14 carbon atoms, more preferably alkyl having 1 to 4 carbon atoms or cycloalkyl having 3 to 8 carbon atoms, more preferably alkyl having 1 to 4 carbon atoms, and even more preferably methyl.

[0119] R Ak may be bonded to Ak via a linking group or a single bond. In this case, examples of the linking group include >O, >S, and >Si(-R)2. R in >Si(-R)2 is hydrogen, an aryl having 6 to 12 carbon atoms, an alkyl having 1 to 6 carbon atoms, or a cycloalkyl having 3 to 14 carbon atoms. R Ak Examples of the structure in which is bonded to Ak via a linking group or a single bond include the following:

[0120] [ka] In the above formulas, * indicates the bonding position.

[0121] In formula (1A) or (1B), the substituent of the aryl ring or heteroaryl ring in ring a, ring b, ring c or the ring containing Y may be a substituent represented by the following formula (A20). [ka]

[0122] The substituent represented by formula (A20) is bonded to two adjacent atoms on the aryl ring or heteroaryl ring at two * marks, respectively. In formula (A20), L is >NR, >O, >Si(-R)2 or >S, R of >NR is substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted alkyl or substituted or unsubstituted cycloalkyl, R of >Si(-R)2 is hydrogen, optionally substituted aryl, optionally substituted alkyl or optionally substituted cycloalkyl, and may be bonded to each other via a linking group, and at least one of R of >NR and >Si(-R)2 may be bonded to at least one aryl ring or heteroaryl ring in ring a, ring b, ring c or a ring including Y via a linking group or a single bond, r is an integer from 1 to 4; R A are each independently hydrogen, substituted or unsubstituted alkyl, or substituted or unsubstituted cycloalkyl, and any R A is any other R A and may be bonded to each other via a linking group or a single bond.

[0123] Examples of the above substituent include any of the following substituents. [ka]

[0124] In each formula, * may be bonded to two or three consecutive (adjacent) atoms on the ring a, ring b, ring c, or any aryl or heteroaryl ring in the ring containing Y.

[0125] R ZThe substituent represented by the formula (A30) is preferably any substituent selected from the substituent group Z or a substituent represented by the formula (A30), more preferably alkyl, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted diarylamino or a substituent represented by the formula (A30), and still more preferably alkyl, phenyl which may be substituted with alkyl, diphenylamino which may be substituted with alkyl, or carbazolyl which may be substituted with alkyl.

[0126] R Z is a substituent, then R Z is preferably in the para position of B (boron). Z is hydrogen or a substituent, and other R Z More preferably, is hydrogen.

[0127] R Y2 The substituent represented by the formula (A30) is preferably any substituent selected from the substituent group Z or a substituent represented by the formula (A30), more preferably alkyl, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted diarylamino or a substituent represented by the formula (A30), and still more preferably alkyl, phenyl which may be substituted with alkyl, diphenylamino which may be substituted with alkyl, or carbazolyl which may be substituted with alkyl.

[0128] <Cycloalkane condensation> In the polycyclic aromatic compound having a structure containing a structural unit represented by formula (1A) or formula (1B), at least one selected from the group consisting of an aryl ring and a heteroaryl ring may be condensed with at least one cycloalkane. The same applies to the polycyclic aromatic compound having a structure containing a structural unit represented by any one of formulas selected from the group consisting of formula (1A-a), formula (1A-b), formula (1A-c), formula (1B-a), formula (1B-b), and formula (1B-c), and the following explanation also applies to the polycyclic aromatic compound represented by any one of these formulas.

[0129] The cycloalkane may be a cycloalkane having 3 to 24 carbon atoms. In this case, at least one hydrogen atom in the cycloalkane may be substituted with an aryl having 6 to 30 carbon atoms, a heteroaryl having 2 to 30 carbon atoms, an alkyl having 1 to 24 carbon atoms, or a cycloalkyl having 3 to 24 carbon atoms, and at least one -CH2- group in the cycloalkane may be substituted with -O-.

[0130] The cycloalkane is preferably a cycloalkane having 3 to 20 carbon atoms, in which at least one hydrogen atom may be substituted with an aryl having 6 to 16 carbon atoms, a heteroaryl having 2 to 22 carbon atoms, an alkyl having 1 to 12 carbon atoms, or a cycloalkyl having 3 to 16 carbon atoms.

[0131] Examples of "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.

[0132] Specific examples of the cycloalkane include cyclopropane, cyclobutane, cyclopentane, cyclohexane, cycloheptane, cyclooctane, cyclononane, cyclodecane, norbornane (bicyclo[2.2.1]heptane), bicyclo[1.1.0]butane, bicyclo[1.1.1]pentane, bicyclo[2.1.0]pentane, bicyclo[2.1.1]hexane, bicyclo[3.1.0]hexane, bicyclo[2.2.2]octane, adamantane, diamantane, decahydronaphthalene, and decahydroazulene, as well as alkyl (particularly methyl)-substituted, halogen (particularly fluorine)-substituted, and deuterium-substituted derivatives of these compounds having 1 to 5 carbon atoms.

[0133] Among these, for example, as shown in the structural formula below, a structure in which at least one hydrogen atom is substituted on the α-carbon atom of a cycloalkane (in a cycloalkyl fused to an aryl ring or heteroaryl ring, the carbon atom adjacent to the fused carbon atom) is preferred, a structure in which two hydrogen atoms are substituted on the α-carbon atom is more preferred, and a structure in which a total of four hydrogen atoms are substituted on the two α-carbon atoms is even more preferred. Examples of such a substituent include alkyl (particularly methyl) having 1 to 5 carbon atoms, halogen (particularly fluorine), and deuterium. In particular, a structure in which a partial structure represented by the following formula (B) is bonded to adjacent carbon atoms in an aryl ring or heteroaryl ring is preferred.

[0134] [ka] In formula (B), * indicates the bonding position.

[0135] The number of cycloalkanes fused to one aryl ring or heteroaryl ring is preferably 1 to 3, more preferably 1 or 2, and even more preferably 1. For example, an example in which one or more cycloalkanes are fused to one benzene ring (phenyl) is shown below. * indicates the bonding position, and the position may be any carbon that constitutes the benzene ring but not the cycloalkane. Fused cycloalkanes such as those in formula (Cy-1-4) and formula (Cy-2-4) may also be fused together. The same applies when the fused ring (group) is an aryl ring or heteroaryl ring other than a benzene ring (phenyl), or when the fused cycloalkane is a cycloalkane other than cyclopentane or cyclohexane.

[0136] [ka]

[0137] At least one -CH2- in a cycloalkane may be replaced with -O-. For example, an example in which one or more -CH2- in a cycloalkane fused to a benzene ring (phenyl) are replaced with -O- is shown below. The same applies when the fused ring (group) is an aryl ring or heteroaryl ring other than a benzene ring (phenyl), or when the fused cycloalkane is a cycloalkane other than cyclopentane or cyclohexane.

[0138] [ka]

[0139] At least one hydrogen atom in the cycloalkane may be substituted. Examples of the substituent include aryl, heteroaryl, diarylamino, diheteroarylamino, arylheteroarylamino, diarylboryl (the two aryls may be bonded via a single bond or a linking group), alkyl, cycloalkyl, alkoxy, aryloxy, substituted silyl, deuterium, cyano, and halogen. For details, see the description of the first substituent above. Among these substituents, alkyl (e.g., alkyl having 1 to 6 carbon atoms), cycloalkyl (e.g., cycloalkyl having 3 to 14 carbon atoms), halogen (e.g., fluorine), and deuterium are preferred. Furthermore, when cycloalkyl is substituted, it may be substituted to form a spiro structure, examples of which are shown below.

[0140] [ka]

[0141] Examples of the cycloalkane condensation include a polycyclic aromatic compound having a structure containing a structural unit represented by formula (1A) or formula (1B), in which an aryl ring and a heteroaryl ring in each of ring a, ring b, ring c, or a ring containing Y is condensed with a cycloalkane.

[0142] Other forms of cycloalkane condensation include polycyclic aromatic compounds having a structure containing a structural unit represented by formula (1A) or formula (1B), for example, where R is an aryl fused with a cycloalkane, >NR, a diarylamino fused with a cycloalkane (fused to this aryl moiety), a carbazolyl fused with a cycloalkane (fused to this benzene ring moiety), or a benzocarbazolyl fused with a cycloalkane (fused to this benzene ring moiety).

[0143] Furthermore, by introducing a cycloalkane structure into the polycyclic aromatic compound of the present invention, a decrease in melting point and sublimation temperature can be expected. This means that sublimation purification, which is almost essential as a method for purifying materials for organic devices such as organic EL elements, which require high purity, can be performed at relatively low temperatures, thereby avoiding thermal decomposition of the materials. This also applies to the vacuum deposition process, which is an effective means for producing organic devices such as organic EL elements. Since the process can be performed at relatively low temperatures, thermal decomposition of the materials can be avoided, resulting in high-performance organic devices. Furthermore, the introduction of a cycloalkane structure improves solubility in organic solvents, making it possible to apply the compound to the production of elements using a coating process. However, the present invention is not particularly limited to these principles.

[0144] <Deuterium, cyano, or halogen substitution> All or part of the hydrogen atoms in the structure containing the structural unit represented by formula (1A) or formula (1B) may be deuterium, cyano, or halogen. The same applies to polycyclic aromatic compounds having a structure containing a structural unit represented by any one of formulas selected from the group consisting of formula (1A-a), formula (1A-b), formula (1A-c), formula (1B-a), formula (1B-b), and formula (1B-c), and the following explanation also applies to polycyclic aromatic compounds represented by any one of formulas selected from the group consisting of formula (1A-a), formula (1A-b), formula (1A-c), formula (1B-a), formula (1B-b), and formula (1B-c).

[0145] For example, in the structure containing the structural unit represented by formula (1A) or formula (1B), the ring a, the ring b, the ring c, or the ring containing Y, the substituents on the ring a, the ring b, the ring c, or the ring containing Y, and X 1 When is >NR, >C(—R)2, or >Si(—R)2, hydrogen atoms in R (= alkyl, cycloalkyl, aryl, or heteroaryl) can be replaced with deuterium, cyano, or halogen. Among these, hydrogen atoms in the aryl or heteroaryl can be replaced with deuterium, cyano, or halogen. Examples of suitable embodiments include those in which all or some of the hydrogen atoms in the aryl or heteroaryl are replaced with deuterium, cyano, or halogen. The halogen atom is fluorine, chlorine, bromine, or iodine, preferably fluorine, chlorine, or bromine, more preferably fluorine or chlorine, and even more preferably fluorine. From the viewpoint of durability, it is also preferable that all or some of the hydrogen atoms in the structure containing the structural unit represented by formula (1A) or formula (1B) are deuterated.

[0146] Specific examples of polycyclic aromatic compounds having a structure containing a structural unit represented by formula (1A) or formula (1B) include compounds represented by any of the following formulas: In addition, the aryl aromatic ring in the following formulas may have, as a substituent, an alkyl having 1 to 4 carbon atoms or a phenyl which may be substituted with an alkyl having 1 to 4 carbon atoms, and at least one hydrogen atom in the structure represented by each formula may be replaced with deuterium.

[0147] [ka]

[0148] Further specific examples of polycyclic aromatic compounds having a structure containing a structural unit represented by formula (1A) or formula (1B) include the following compounds: Note that polycyclic aromatic compounds having a structure containing a structural unit represented by formula (1A) or formula (1B) are not limited to the following specific examples.

[0149] [ka]

[0150]

change

[0151]

change

[0152]

change

[0153]

change

[0154]

change

[0155]

change

[0156]

change

[0157]

change

[0158]

change

[0159]

change

[0160]

change

[0161] [ka]

[0162] [ka]

[0163] <Method of producing polycyclic aromatic compounds> Polycyclic aromatic compounds represented by formula (1A) or (1B) can be synthesized by first linking ring a with ring b and ring c via a linking group (a group containing nitrogen) to produce a precursor (reaction 1), then linking ring a, ring b, and ring c with boron to produce an intermediate (reaction 2), and finally linking ring b and ring c via a linking group (reaction 3). Reaction 1 can be a common reaction such as the Buchwald-Hartwig reaction. Reaction 2 can be a tandem hetero-Friedel-Crafts reaction (sequential aromatic electrophilic substitution reaction, hereinafter the same). Reaction 3 can be a common reaction such as an aromatic nucleophilic substitution reaction, the Ullmann reaction, or the Buchwald-Hartwig reaction.

[0164] The second reaction, as shown in the following schemes (1) and (2), introduces boron to bond the a, b, and c rings. First, the halogen atom between the nitrogen atoms is exchanged with n-butyllithium, sec-butyllithium, or t-butyllithium. Next, boron trichloride or boron tribromide is added to perform lithium-boron metal exchange. A Brønsted base such as N,N-diisopropylethylamine is then added to carry out a tandem boron-Friedel-Crafts reaction to obtain the desired product. A Lewis acid such as aluminum trichloride may be added to accelerate the second reaction.

[0165] [ka]

[0166] By appropriately selecting the raw materials to be used, it is possible to synthesize polycyclic aromatic compounds and multimers thereof having substituents at desired positions.

[0167] Specific examples of solvents used in the above reactions include t-butylbenzene and xylene.

[0168] Examples of orthometalation reagents used in the above schemes (1) and (2) include alkyllithiums such as methyllithium, n-butyllithium, sec-butyllithium, and t-butyllithium, and organic alkali compounds such as lithium diisopropylamide, lithium tetramethylpiperidide, lithium hexamethyldisilazide, and potassium hexamethyldisilazide.

[0169] Examples of the metal-boron metal exchange reagent used in the above schemes (1) and (2) include boron halides such as boron trifluoride, boron trichloride, boron tribromide, and boron triiodide, boron alkoxides, and boron aryloxylates.

[0170] Examples of the Bronsted base used in the above schemes (1) and (2) include N,N-diisopropylethylamine, triethylamine, 2,2,6,6-tetramethylpiperidine, 1,2,2,6,6-pentamethylpiperidine, N,N-dimethylaniline, N,N-dimethyltoluidine, 2,6-lutidine, sodium tetraphenylborate, potassium tetraphenylborate, triphenylborane, tetraphenylsilane, ArBNa, ArBK, ArB, and ArSi (wherein Ar is an aryl such as phenyl).

[0171] Examples of Lewis acids used in the above schemes (1) and (2) include AlCl3, AlBr3, AlF3, BF3·OEt2, BCl3, BBr3, 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, and CoBr3.

[0172] In the above schemes (1) and (2), a Brønsted base or Lewis acid may be used to promote the tandem hetero-Friedel-Crafts reaction. However, when using boron halides such as boron trifluoride, boron trichloride, boron tribromide, or boron triiodide, acids such as hydrogen fluoride, hydrogen chloride, hydrogen bromide, and hydrogen iodide are generated as the aromatic electrophilic substitution reaction proceeds, so the use of a Brønsted base to capture the acid is effective. On the other hand, when using boron amination halides or boron alkoxides, amines and alcohols are generated as the aromatic electrophilic substitution reaction proceeds, so the use of a Brønsted base is often unnecessary. However, because the amino and alkoxy groups have low elimination ability, the use of a Lewis acid to promote their elimination is effective.

[0173] The polycyclic aromatic compounds and multimers thereof of the present invention also include those in which at least some of the hydrogen atoms are substituted with deuterium or with halogens such as fluorine or chlorine. 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.

[0174] 2. Organic Devices The polycyclic aromatic compound of the present invention can be used as a material for organic devices, such as organic electroluminescent devices, organic field-effect transistors, and organic thin-film solar cells.

[0175] 2-1. Organic electroluminescent device 2-1-1. Structure of organic electroluminescent device FIG. 1 is a schematic cross-sectional view showing an example of an organic EL element. The organic EL device 100 shown in FIG. 1 includes a substrate 101, an anode 102 provided on the substrate 101, a hole injection layer 103 provided on the anode 102, a hole transport layer 104 provided on the hole injection layer 103, an emitting layer 105 provided on the hole transport layer 104, an electron transport layer 106 provided on the emitting layer 105, an electron injection layer 107 provided on the electron transport layer 106, and a cathode 108 provided on the electron injection layer 107.

[0176] The organic EL element 100 may be fabricated in the reverse order, for example, to have a substrate 101, a cathode 108 provided on the substrate 101, an electron injection layer 107 provided on the cathode 108, an electron transport layer 106 provided on the electron injection layer 107, an emitting layer 105 provided on the electron transport layer 106, a hole transport layer 104 provided on the emitting layer 105, a hole injection layer 103 provided on the hole transport layer 104, and an anode 102 provided on the hole injection layer 103.

[0177] Not all of the above layers are essential, and the minimum structural unit is a configuration consisting of an anode 102, an 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 may be optionally provided. Furthermore, each of the above layers may consist of a single layer or multiple layers.

[0178] The layers constituting the organic EL element may be configured as follows: "substrate / anode / hole injection layer / hole transport layer / light-emitting layer / electron transport layer / electron injection layer / cathode" as described above, as well as "substrate / anode / hole transport layer / light-emitting layer / electron transport layer / electron injection layer / cathode", "substrate / anode / hole injection layer / light-emitting layer / electron transport layer / electron injection layer / cathode", "substrate / anode / hole injection layer / hole transport layer / light-emitting ... transport The configuration may be, for example, "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 transport layer / light-emitting layer / electron transport layer / cathode," "substrate / anode / hole injection layer / light-emitting layer / electron injection layer / cathode," "substrate / anode / hole injection layer / light-emitting layer / electron transport layer / cathode," "substrate / anode / light-emitting layer / electron transport layer / cathode," or "substrate / anode / light-emitting layer / electron injection layer / cathode."

[0179] 2-1-2. Substrate in organic electroluminescent device The substrate 101 is a support for the organic EL device 100 and is typically made of quartz, glass, metal, plastic, or the like. The substrate 101 may be formed into a plate, film, or sheet shape depending on the purpose, and may be, for example, a glass plate, a metal plate, a metal foil, a plastic film, or a plastic sheet. Among these, glass plates and plates made of transparent synthetic resins such as polyester, polymethacrylate, polycarbonate, and polysulfone are preferred. For glass substrates, soda-lime glass or alkali-free glass may be used, and the thickness may be sufficient to maintain mechanical strength. Furthermore, to improve gas barrier properties, the substrate 101 may be provided with a gas barrier film such as a dense silicon oxide film on at least one side. Providing a gas barrier film is particularly preferred when a synthetic resin plate, film, or sheet with poor gas barrier properties is used as the substrate 101.

[0180] 2-1-3. Anode in organic electroluminescent device The anode 102 serves to inject 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 via these layers.

[0181] Materials for forming the anode 102 include inorganic and organic compounds. Examples of inorganic compounds include metals (aluminum, gold, silver, nickel, palladium, chromium, etc.), metal oxides (indium oxide, tin oxide, indium-tin oxide (ITO), indium-zinc oxide (IZO), etc.), metal halides (copper iodide, etc.), copper sulfide, carbon black, ITO glass, and NESA glass. Examples of organic compounds include polythiophenes such as poly(3-methylthiophene), and conductive polymers such as polypyrrole and polyaniline. In addition, materials can be appropriately selected from those used as anodes in organic EL devices.

[0182] 2-1-4. Hole injection layer and hole transport layer in organic electroluminescent device The hole injection layer 103 serves to efficiently inject holes migrating from the anode 102 into the light-emitting layer 105 or the hole transport layer 104. The hole transport layer 104 serves to efficiently transport 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 each formed by laminating or mixing one or more types of hole injection / transport materials. Alternatively, a layer may be formed by adding an inorganic salt such as iron (III) chloride to the hole injection / transport material.

[0183] A hole injection / transport material must be able to efficiently inject and transport holes from the positive electrode between electrodes to which an electric field is applied, and it is desirable for the material to have high hole injection efficiency and efficiently transport the injected holes. To achieve this, it is desirable for the material to have a low ionization potential, high hole mobility, excellent stability, and be less likely to generate impurities that act as traps during production and use.

[0184] 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, p-type semiconductors, and known compounds used in hole injection layers and hole transport layers of organic EL devices. 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-carbazol-3-yl)-[1,1'-biphenyl]-4,4'-diamine, N 4 ,N 4 ,N 4' ,N 4'-tetra[1,1'-biphenyl]-4-yl)-[1,1'-biphenyl]-4,4'-diamine, triphenylamine derivatives such as 4,4',4"-tris(3-methylphenyl(phenyl)amino)triphenylamine, starburst amine derivatives, etc.), stilbene derivatives, phthalocyanine derivatives (metal-free, copper phthalocyanine, etc.), pyrazoline derivatives, hydrazone compounds, benzofuran derivatives, thiophene derivatives, oxadiazole derivatives, quinoxaline derivatives Examples of the material include conductors (for example, 1,4,5,8,9,12-hexaazatriphenylene-2,3,6,7,10,11-hexacarbonitrile), heterocyclic compounds such as porphyrin derivatives, polysilanes, etc. Among polymers, polycarbonates and styrene derivatives having the above-mentioned monomers in their side chains, polyvinylcarbazole, and polysilanes are preferred, but there are no particular limitations on the material as long as it is a compound that can form a thin film required for fabricating a light-emitting device, can inject holes from the anode, and can transport holes.

[0185] It is also known that the conductivity of organic semiconductors is strongly influenced by their doping. Such organic semiconductor matrix materials consist of compounds with good electron-donating or electron-accepting properties. Strong electron acceptors such as tetracyanoquinone dimethane (TCNQ) or 2,3,5,6-tetrafluorotetracyano-1,4-benzoquinone dimethane (F4TCNQ) are known for doping with electron-donating substances (see, for example, M. Pfeiffer, A. Beyer, T. Fritz, K. Leo, Appl. Phys. Lett., 73(22), 3202-3204 (1998) and J. Blochwitz, M. Pfeiffer, T. Fritz, K. Leo, Appl. Phys. Lett., 73(6), 729-731 (1998)). These generate so-called holes via an electron transfer process in the electron-donating base material (hole-transporting material). The conductivity of the base material varies considerably depending on the number and mobility of holes. Known matrix materials with hole transport properties include benzidine derivatives (such as TPD) or starburst amine derivatives (such as TDATA), as well as certain metal phthalocyanines (e.g., zinc phthalocyanine (ZnPc)) (see JP 2005-167175 A).

[0186] The hole injection layer material and the hole transport layer material described above can also be used as hole layer materials in the form of a polymer compound obtained by polymerizing a reactive compound substituted with a reactive substituent as a monomer, or a crosslinked polymer thereof, or a pendant polymer compound obtained by reacting a main-chain polymer with the reactive compound, or a crosslinked pendant polymer thereof.

[0187] 2-1-5. Emitting layer in organic electroluminescent device The polycyclic aromatic compound of the present invention is preferably used as a material for forming one or more organic layers in an organic electroluminescent device, and more preferably as a material for forming an emitting layer. In the emitting layer, the compound of the present invention having a structure containing a structural unit represented by formula (1A) or formula (1B) can be used as an emitting dopant for a TTF (Triplet-Triplet Fusion) device, an emitting dopant for a TAF device, or an emitting dopant for a phosphorescence-assisted device. From the viewpoint of long life, a TTF emitting dopant is preferred, and from the viewpoint of high efficiency, an emitting dopant for a TAF device or an emitting dopant for a phosphorescence-assisted device is preferred. From the viewpoint of ease of production as fewer materials are used in the device, an emitting dopant for a TTF device is preferred, and an emitting dopant for a phosphorescence-assisted device is preferred for high efficiency and long life.

[0188] The light-emitting layer 105 is a layer that emits light by recombining holes injected from the anode 102 and electrons injected from the cathode 108 between electrodes to which an electric field is applied. The material for the light-emitting layer 105 may be a compound that emits light when excited by the recombination of holes and electrons (a light-emitting compound), and is preferably a compound that can be formed into a stable thin film and that exhibits strong luminescence (fluorescence) efficiency in a solid state. The polycyclic aromatic compound of the present invention can be used as a material for a light-emitting layer, and may be used as a dopant material or a host material, but is preferably used as a dopant material.

[0189] The light-emitting layer may be a single layer or multiple layers, each formed from materials for the light-emitting layer (host material, dopant material). The host material and the dopant material may each be one type or a combination of multiple types. The dopant material may be contained entirely or partially in the host material. As a doping method, the dopant material can be formed by co-evaporation with the host material, or it may be mixed with the host material in advance and then vapor-deposited simultaneously.

[0190] The amount of the host material used varies depending on the type of host material and may be determined according to the properties of the host material. The amount of the host material used is preferably 50 to 99.999% by mass, more preferably 80 to 99.95% by mass, and even more preferably 90 to 99.9% by mass of the total mass of the materials for the light-emitting layer.

[0191] The amount of dopant material used varies depending on the type of dopant material and may be determined according to the properties of the dopant material. The amount of dopant used is preferably 0.001 to 50% by mass, more preferably 0.05 to 20% by mass, and even more preferably 0.1 to 10% by mass, of the total mass of the materials for the light-emitting layer. The above range is preferable in that, for example, concentration quenching can be prevented.

[0192] As the dopant material, an emitting dopant and an assisting dopant material may be used. It is preferable to use a thermally activated delayed fluorescent material as the assisting dopant material. In an organic electroluminescent device using an assisting dopant material, a low concentration of the emitting dopant material is preferred in terms of preventing concentration quenching. A high concentration of the assisting dopant material is preferred in terms of the efficiency of the thermally activated delayed fluorescent mechanism. Furthermore, in an organic electroluminescent device using a thermally activated delayed fluorescent assisting dopant material, a low concentration of the emitting dopant material is preferred compared to the amount of the assisting dopant material in terms of the efficiency of the thermally activated delayed fluorescent mechanism of the assisting dopant material.

[0193] When an assisting dopant material is used, the amounts of the host material, assisting dopant material, and emitting dopant material used are approximately 40 to 99 mass%, 59 to 1 mass%, and 20 to 0.001 mass%, respectively, based on the total mass of the materials for the light-emitting layer, preferably 60 to 95 mass%, 39 to 5 mass%, and 10 to 0.01 mass%, respectively, and more preferably 70 to 90 mass%, 29 to 10 mass%, and 5 to 0.05 mass%, respectively.

[0194] <Host material> Examples of host materials include fused ring derivatives of anthracene and pyrene, which have long been known as light emitters, bisstyryl derivatives such as bisstyrylanthracene derivatives and distyrylbenzene derivatives, tetraphenylbutadiene derivatives, cyclopentadiene derivatives, fluorene derivatives, benzofluorene derivatives, N-phenylcarbazole derivatives, and carbazonitrile derivatives.

[0195] The lowest excited triplet energy level (E T1 ) is the highest E in the emitting layer from the viewpoint of promoting TADF generation without inhibiting it in the emitting layer. T1 E of a dopant or assisting dopant having T1It is preferable that the E T1 is the E of the above dopant or assisting dopant T1 It is preferable that the E of the host material is higher by 0.01 eV or more, more preferably by 0.03 eV or more, and further preferably by 0.1 eV or more. T1 is preferably 2.70 eV or more, more preferably 2.73 eV or more, and even more preferably 2.80 eV or more. A TADF active compound may be used as the host material.

[0196] 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.

[0197] [Anthracene derivatives] For anthracene derivatives, reference can be made to the descriptions in paragraphs 0124 to 0192 of JP 2020-136284 A and paragraphs 0072 to 0257 of JP 2021-118354 A. Specifically, the anthracene derivative includes a compound represented by formula (3-H) or a compound represented by formula (3-H2).

[0198] [ka]

[0199] In formula (3-H), X and Ar 4 are each independently hydrogen or a group selected from the substituent group Z, and all of X and Ar 4 cannot simultaneously become hydrogen. At least one hydrogen atom in the compound represented by formula (3-H) may be replaced by halogen, cyano, or deuterium.

[0200] In formula (3-H2), Ar cis a substituted or unsubstituted aryl or a substituted or unsubstituted heteroaryl, and R c is hydrogen, alkyl, or cycloalkyl, and Ar 11 , Ar 12 , Ar 13 , Ar 14 , Ar 15 , Ar 16 , Ar 17 , and Ar 18 are each independently hydrogen or a group selected from the substituent group Z, and at least one hydrogen in the compound represented by formula (3-H2) may be replaced with halogen, cyano, or deuterium.

[0201] In the compound represented by formula (3-H), each X is preferably independently a group represented by formula (3-X1), formula (3-X2), or formula (3-X3). 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, no two Xs are simultaneously groups represented by formula (3-X3). More preferably, no two Xs are simultaneously groups represented by formula (3-X2).

[0202] [ka]

[0203] Furthermore, a multimer (preferably a dimer) may be formed using the structure represented by formula (3-H) as a unit structure. In this case, for example, the unit structures represented by formula (3-H) may be bonded to each other via X, where X may be a single bond, an arylene (such as phenylene, biphenylene, or naphthylene), or a heteroarylene (a divalent group such as a pyridine ring, a dibenzofuran ring, a dibenzothiophene ring, a carbazole ring, a benzocarbazole ring, or a phenyl-substituted carbazole ring).

[0204] The naphthylene moieties in formula (3-X1) and formula (3-X2) may be fused with one benzene ring. The fused structures are as follows: [ka]

[0205] Ar 1 and Ar 2 are each independently hydrogen, phenyl, biphenylyl, terphenylyl, quaterphenylyl, naphthyl, phenanthryl, fluorenyl, benzofluorenyl, chrysenyl, triphenylenyl, pyrenylyl, or a group represented by formula (A) (including carbazolyl, benzocarbazolyl, and phenyl-substituted carbazolyl). 1 or Ar 2 is 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 *.

[0206] Ar 3 is phenyl, biphenylyl, terphenylyl, quaterphenylyl, naphthyl, phenanthryl, fluorenyl, benzofluorenyl, chrysenyl, triphenylenyl, pyrenylyl, or a group represented by formula (A) (including carbazolyl, benzocarbazolyl, and phenyl-substituted carbazolyl). 3 is a group represented by formula (A), the group represented by formula (A) is bonded to the single bond represented by a straight line in formula (3-X3) at the *. That is, the anthracene ring of formula (3-H) and the group represented by formula (A) are directly bonded.

[0207] Also, Ar 3 may have a substituent, and Ar 3At least one hydrogen atom in the formula (A) may be further substituted with an alkyl group having 1 to 4 carbon atoms, a cycloalkyl group having 5 to 10 carbon atoms, phenyl, biphenylyl, terphenylyl, naphthyl, phenanthryl, fluorenyl, chrysenyl, triphenylenyl, pyrenylyl, or a group represented by formula (A) (including carbazolyl and phenyl-substituted carbazolyl). 3 When the substituent of is a group represented by formula (A), the group represented by formula (A) is Ar in formula (3-X3) at *. 3 and combine.

[0208] Ar 4 are preferably each independently hydrogen, phenyl, biphenylyl, terphenylyl, naphthyl, or silyl substituted with alkyl having 1 to 4 carbon atoms (such as methyl, ethyl, and t-butyl) and / or cycloalkyl having 5 to 10 carbon atoms.

[0209] Furthermore, hydrogen atoms in the chemical structure of the anthracene compound represented by formula (3-H) may be replaced with a group represented by formula (A). When substituted with a group represented by formula (A), the group represented by formula (A) replaces at least one hydrogen atom in the compound represented by formula (3-H) at the *.

[0210] The group represented by formula (A) is one of the substituents that the anthracene compound represented by formula (3-H) may have. [ka]

[0211] In formula (A), Y is —O—, —S—, or >NR 29 and R 21 ~R 28 are each independently hydrogen or a group selected from the substituent group Z, and R 21 ~R 28 adjacent groups among R may be bonded to each other to form a hydrocarbon ring, an aryl ring, or a heteroaryl ring; 29is hydrogen or substituted or unsubstituted aryl. At least one hydrogen in formula (A) may be replaced with halogen, cyano or deuterium. In formula (A), Y is preferably —O—.

[0212] [Hole-transporting host material (HH)] Preferred examples of the hole-transporting host material (HH) include a compound represented by formula (HH-1) and a compound having a partial structure represented by formula (HH-1).

[0213] [ka]

[0214] In formula (HH-1), Q is >O, >S, or >NA; In the formula (HH-1), one carbon atom adjacent to the carbon atom to which Q is bonded in each of the two phenyl groups may be bonded to each other via L, L is a single bond, >O, >S or >C(-A)2; A is a hydrogen atom, aryl, heteroaryl, diarylamino, alkyl, cycloalkyl, alkoxy or aryloxy, and two As in >C(-A)2 may bond to each other to form an aryl, heteroaryl or cycloalkyl.

[0215] When the hole-transporting host material contains a structure represented by formula (HH-1) as a partial structure, it may contain one of the partial structures 1, but it is also preferable to contain two or more of them. When two or more partial structures are contained, the two or more partial structures may be the same or different. The two or more partial structures may be bonded to each other by a single bond, may be bonded so that any rings contained in the partial structures are shared, or may be bonded so that any rings contained in the partial structures are fused to each other. The partial structure may further have a substituent selected from aryl, heteroaryl, diarylamino, or aryloxy.

[0216] The hole-transporting host material is preferably a compound containing 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 fused polycyclic ring containing phenoxazine or phenothiazine. The hole-transporting host material may contain one such partial structure 1, but preferably contains two or more. When two or more partial structures are contained, the two or more partial structures may be the same or different.

[0217] Specific examples of the hole-transporting host material include the following compounds. [ka]

[0218] [ka]

[0219] [ka]

[0220] [ka]

[0221] [ka]

[0222] [ka]

[0223] [ka]

[0224] [ka]

[0225] [ka]

[0226] Of the above, 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 are preferred.

[0227] [Electron-transporting host material (EH)] Examples of the electron transporting host material (EH) include a compound represented by formula (EH-1) and a compound having a partial structure represented by formula (EH-1). [ka]

[0228] In formula (EH-1), Each J is independently =C(-A)- or =N-, and at least three J's are =C(-A)-; Z is -O-, -S-, -C(=O)-, -P(=O)(-A)-, -P(=S)(-A)-, -N(-A)-, -B(-A)- or -S(=O)2-; J adjacent to the carbon atom to which Z is bonded and A to which Z is bonded may be bonded to each other via L, L is a single bond, >O, >S or >C(-A)2; A is hydrogen, aryl, heteroaryl, diarylamino, alkyl, cycloalkyl, triarylsilyl, alkoxy or aryloxy, and two A's in >C(-A)2 may be bonded to each other to form an aryl, heteroaryl or cycloalkyl; When all J's are =C(-A)-, then either one of A or Z contains a heteroatom.

[0229] For aryl, heteroaryl, diarylamino, alkyl, cycloalkyl, triarylsilyl, alkoxy, or aryloxy represented by A in formula (EH-1), the explanation for A in formula (HH-1) can be referred to. When two As in formula (EH-1) bond to each other to form an aryl, heteroaryl, or cycloalkyl, the explanation for the aryl, heteroaryl, or cycloalkyl can also be referred to in formula (HH-1).

[0230] When the electron-transporting host material contains a structure represented by formula (EH-1) as a partial structure, it may contain one such partial structure, but it is also preferable to contain two or more such partial structures. When two or more such partial structures are contained, the two or more partial structures may be the same or different. The two or more partial structures may be bonded to each other by a single bond, may be bonded so that any rings contained in the partial structures are shared, or may be bonded so that any rings contained in the partial structures are fused to each other. The partial structure may further have a substituent selected from aryl, heteroaryl, diarylamino, or aryloxy.

[0231] Specific examples of the electron transporting host material include the following compounds. [ka]

[0232] [ka]

[0233] [ka]

[0234] [ka]

[0235] [ka]

[0236] [ka]

[0237] [ka]

[0238] [ka]

[0239] Another preferred example of the electron-transporting host material (a compound having a partial structure represented by formula (EH-1)) is a polycyclic aromatic compound represented by the following formula (EH-1b), or a multimer of a polycyclic aromatic compound having a plurality of structures represented by the following formula (EH-1b). [ka]

[0240] In formula (EH-1b), R 1 , R 2 , R 3 , R 4 and R 5 (Hereinafter referred to as “R 1 and the like) are each independently hydrogen or a substituent selected from the group Z of substituents. In formula (EH-1b), X 1 and X 2 are each independently >NR (amine nitrogen), >O, >C(-R)2, >S or >Se, and X 1 and X 2 are never both >C(-R)2, R in the >NR and >C(-R)2 each independently represents hydrogen or a substituent selected from the substituent group Z, and may be further substituted with an aryl, heteroaryl, alkyl, or cycloalkyl (all of which are second substituents), and R in the >NR and >C(-R)2 each independently may be bonded to at least one of the ring a, ring b, and ring c via a linking group or a single bond. Y 1 , Y 2 , Y 3 , Y 4 , Y 5 and Y 6 (hereinafter, "Y 1 each independently represents ═C(—R)— or ═N— (pyridinic nitrogen), and at least one represents ═N— (pyridinic nitrogen); Each R in the =C(-R)- is independently hydrogen or a substituent selected from the substituent group Z. R 1 , R 2 , R 3 , R 4 and R 5 , and the Y 1 ~Y 6 Adjacent groups among R in =C(-R)- as above may be bonded to each other to form an aryl ring or a heteroaryl ring together with at least one of ring a, ring b, and ring c, and at least one hydrogen atom in the formed ring may be substituted with an aryl, heteroaryl, diarylamino, diheteroarylamino, arylheteroarylamino, diarylboryl (two aryls may be bonded via a single bond or a linking group), alkyl, cycloalkyl, alkoxy, or aryloxy (all of these, first substituents), and at least one hydrogen atom in these may be further substituted with an aryl, heteroaryl, alkyl, or cycloalkyl (all of these, second substituents). At least one hydrogen atom in the compound and structure represented by formula (EH-1b) may be substituted with cyano, halogen, or deuterium.

[0241] In formula (EH-1b), R 1 , R 2 , R 3 , R 4 and R 5 are all hydrogen atoms, or R 3 and R 4 are both hydrogen and R 1 , R 2 and R 5 Preferably, one or more selected from the group consisting of are substituents other than hydrogen, and the rest are hydrogen. The substituents are preferably alkyl, aryl which may be substituted with alkyl or heteroaryl, heteroaryl which may be substituted with alkyl or aryl, or diarylamino which may be substituted with alkyl or aryl. In this case, the alkyl is preferably an alkyl having 1 to 6 carbon atoms (e.g., methyl, t-butyl), the aryl is preferably phenyl or biphenyl, and the heteroaryl is preferably triazinyl, carbazolyl (e.g., 2-carbazolyl, 3-carbazolyl, 9-carbazolyl), pyrimidinyl, pyridinyl, dibenzofuranyl, or dibenzothienyl. Specific examples include phenyl, biphenyl, diphenyltriazinyl, carbazolyltriazinyl, monophenylpyrimidinyl, diphenylpyrimidinyl, carbazolyltriazinyl, pyridinyl, dibenzofuranyl, and dibenzothienyl.

[0242] Y 1 etc. are each independently =C(-R)- or =N-, and at least one is =N-. Y 1 ~Y 6 Any of the groups may be =N-. Preferably, Y 1 and Y 6 =N-(a ring is a pyrimidine ring), Y 1 or Y 6 =N-(a ring 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 ~Y5 is =N-(ring b and ring c are pyrimidine rings), Y 1 , Y 3 , Y 4 and Y 6 is =N-(a ring is a pyrimidine ring, b ring and c ring are pyridine rings), Y 1 , Y 2 , Y 5 and Y 6 is =N-(a ring is a pyrimidine ring, b ring and c ring are pyridine rings), Y 1 ~Y 6 is =N-(a ring, b ring and c ring are pyrimidine rings), Y 2 or Y 5 is =N-(ring b or ring c is a pyridine ring).

[0243] In addition to the above =N- arrangement, X 1 and X 2 is preferably >O, and a polycyclic aromatic compound containing a partial structure represented by any of the following formulas is preferred. [ka]

[0244] 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 It has. Specific examples of the polycyclic aromatic compound represented by formula (EH-1b) are shown below.

[0245] [ka]

[0246] [ka]

[0247] [ka]

[0248] [ka]

[0249] [ka]

[0250] [ka]

[0251] Of the above, 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, EH-1-72, EH-1-90, EH-1-100, EH-1-101, EH-1-104, EH-1-115, EH-1-117, EH-1-120, EH-1-122, EH-1-123, and EH-1-127 to EH-1-130 are preferred.

[0252] [Combination of hole-transporting host material and electron-transporting host material] The combination of the hole-transporting host material and the electron-transporting host material is such that the HOMO, LUMO, and lowest excited triplet energy levels (E T1 ) is selected. With regard to the 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 the HOMO(HH) is shallower than the HOMO(EH) by 0.10 eV or more and the LUMO(HH) is deeper than the HOMO(EH) by 0.10 eV or more is preferred, a combination in which the HOMO(HH) is shallower than the HOMO(EH) by 0.20 eV or more and the LUMO(HH) is deeper than the HOMO(EH) by 0.20 eV or more is more preferred, and a combination in which the HOMO(HH) is shallower than the HOMO(EH) by 0.25 eV or more and the LUMO(HH) is deeper than the HOMO(EH) by 0.25 eV or more is even more preferred.

[0253] The hole-transporting host material and the electron-transporting host material may be combined to form an association called an exciplex. It is generally known that exciplexes are easily formed between a material with a relatively deep LUMO level and a material with a shallow HOMO level. The interaction between the hole-transporting host material and the electron-transporting host material, specifically, whether an exciplex is formed, can be determined by forming a single-layer film consisting of only the hole-transporting host material and the electron-transporting host material under the same conditions as for forming the light-emitting layer, measuring the emission spectrum (fluorescence or phosphorescence spectrum), and comparing the obtained emission spectrum with the emission spectrum of each of the hole-transporting host material and the electron-transporting host material alone. This can be determined by the spectrum of a mixed film containing the hole-transporting host material and the electron-transporting host material exhibiting an emission wavelength different from both the spectrum of the film of the hole-transporting host material and the spectrum of the film of the electron-transporting host material. Specifically, a difference of 10 nm or more in the peak wavelength of the spectrum can be used as an indicator.

[0254] Specific examples of the combination of a hole-transporting host material and an electron-transporting host material that do not form an exciplex include the following combinations: T1In order to satisfy the physical property values ​​of (1), the hole-transporting host material is preferably a compound having carbazole, dibenzofuran, dibenzothiophene, triarylamine, indolecarbazole, or benzoxazinophenoxazine as a partial structure, more preferably a compound having carbazole, dibenzofuran, or dibenzothiophene as a partial structure, and even more preferably a compound having carbazole as a partial structure. Similarly, the electron-transporting host material is preferably a compound having pyridine, triazine, phosphine oxide, benzofuropyridine, or dibenzoxasiline as a partial structure, more preferably a compound having triazine, phosphine oxide, benzofuropyridine, or dibenzoxasiline as a partial structure, and even more preferably a compound having triazine.

[0255] More specifically, the hole-transporting 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-transporting host material is preferably selected from the group consisting of EH-1-1 to EH-1-4, EH-1-5, EH-1-6, EH-1-7, EH-1-8, EH-1-9, EH-1-10, EH-1-11, EH-1-12, EH-1-13, EH-1-14, EH-1-15, EH-1-16, EH-1-17, EH-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. It is preferable that the polyisoprene is selected from the group consisting of 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-1-71, EH-1-72, EH-1-90, 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 to 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.

[0256] Specific examples of the combination of a hole-transporting host material and an electron-transporting host material that form an exciplex include the following combinations: T1 In order to satisfy the physical property values ​​of (1), the hole-transporting host material is preferably a compound having carbazole, triarylamine, indolecarbazole, or benzoxazinophenoxazine as a partial structure, more preferably a compound having triarylamine, indolecarbazole, or benzoxazinophenoxazine as a partial structure, and even more preferably a compound having triarylamine as a partial structure. Similarly, the electron-transporting host material is preferably a compound having pyridine, triazine, phosphine oxide, or benzofuropyridine as a partial structure, more preferably a compound having triazine, phosphine oxide, benzofuropyridine, or dibenzoxasiline as a partial structure, and even more preferably a compound having phosphine oxide or triazine.

[0257] More specifically, the hole-transporting 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, and HH-1-24, and the electron-transporting 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- It is preferable that the compound is selected from the group consisting of EH-1-51 to EH-1-57, EH-1-59, EH-1-66, EH-1-68, EH-1-90, 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 to 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-1-117, 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.

[0258] Other specific combinations of hole-transporting host materials and electron-transporting host materials are described in Organic Electronics 66 (2019) 227-24, Advanced Functional Materals 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 C, 2018, 6, 8784-8792, Angewante Chemie International Edition, 2018, 57, 12380-12384, Advanced Functional Materials, 24, 2014, 3970, Advanced Materials, 26, 2014, 5684, and Synthetic Metals, 201, 2015, 49 can be referenced.

[0259] <Dopant materials> The polycyclic aromatic compound of the present invention having a structure containing a structural unit represented by formula (1A) or formula (1B) is preferably used as a dopant material. In addition, known compounds can be used as dopant materials, and can be selected from a variety of materials depending on the desired emission color.Specific examples include fused ring derivatives of phenanthrene, anthracene, pyrene, tetracene, pentacene, perylene, naphthopyrene, dibenzopyrene, rubrene, and chrysene, 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, and tetraphenylbutadiene. derivatives, cyclopentadiene derivatives, bisstyryl derivatives such as bisstyryl anthracene derivatives and distyrylbenzene derivatives (JP Patent Publication No. 245087 / 1999), bisstyrylarylene derivatives (JP Patent Publication No. 247278 / 1990), diazaindacene derivatives, furan derivatives, benzofuran derivatives, isobenzofuran derivatives such as phenylisobenzofuran, dimesitylisobenzofuran, di(2-methylphenyl)isobenzofuran, di(2-trifluoromethylphenyl)isobenzofuran, and phenylisobenzofuran Coumarin derivatives such as dibenzofuran derivatives, 7-dialkylaminocoumarin derivatives, 7-piperidinocoumarin derivatives, 7-hydroxycoumarin derivatives, 7-methoxycoumarin derivatives, 7-acetoxycoumarin derivatives, 3-benzothiazolylcoumarin derivatives, 3-benzimidazolylcoumarin derivatives, and 3-benzoxazolylcoumarin derivatives, dicyanomethylenepyran derivatives, dicyanomethylenethiopyran derivatives, polymethine derivatives, cyanine derivatives, oxobenzanthracene derivatives, xanthene derivatives, and rhodamine derivatives. conductors, fluorescein derivatives, pyrylium derivatives, carbostyril derivatives, acridine derivatives, oxazine derivatives, phenylene oxide derivatives, quinacridone derivatives, quinazoline derivatives, pyrrolopyridine derivatives, furopyridine derivatives, 1,2,5-thiadiazolopyrene derivatives, pyrromethene derivatives, perinone derivatives, pyrrolopyrrole derivatives, squarylium derivatives, violanthrone derivatives, phenazine derivatives, acridone derivatives, deazaflavin derivatives, fluorene derivatives, and benzofluorene derivatives.

[0260] As the emitting dopant material, it is also preferable to use the boron-containing polycyclic aromatic compounds described in WO 2015 / 102118, WO 2020 / 162600, paragraphs 0097 to 0269 of JP 2021-077890, etc. These boron-containing polycyclic aromatic compounds may be used as the emitting dopant material, and the polycyclic aromatic compound of the present invention having a structure containing a structural unit represented by formula (1A) or formula (1B) may be used as the assisting dopant material. The boron-containing polycyclic aromatic compound may be a phosphor or a TADF material (thermally activated delayed phosphor). The boron-containing polycyclic aromatic compound is preferably a blue-emitting compound.

[0261] Preferred examples of the boron-containing polycyclic aromatic compound include compounds represented by the following formula (12), formula (13) or formula (14). [ka]

[0262] ring A, ring B, ring C and ring D are each independently a substituted or unsubstituted aryl ring or a substituted or unsubstituted heteroaryl ring; Y is B (boron), X 1 , X 2 , X 3 and X 4 are each independently >O, >NR, >S, or >Se, and R of the >NR is a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, or a substituted or unsubstituted alkyl, and R of the >NR may be bonded to the A ring, the B ring, the C ring, and / or the D ring via a linking group or a single bond; R 1 and R 2 are each independently hydrogen, alkyl having 1 to 6 carbon atoms, aryl having 6 to 12 carbon atoms, heteroaryl having 2 to 15 carbon atoms, or diarylamino (wherein aryl has 6 to 12 carbon atoms), Z 1 and Z2 are each independently any substituent selected from the substituent group Z, and Z 1 may be bonded to ring A via a linking group or a single bond, and Z 2 may be bonded to the ring C via a linking group or a single bond, and At least one hydrogen atom in the compound represented by formula (12) may be replaced by cyano, halogen, or deuterium.

[0263] Substituents when the aryl or heteroaryl rings in rings A, B, C and D of formula (12) are substituted, and Z 1 , Z 2 Examples of the substituent include a substituent selected from the group Z of substituents.

[0264] X in equation (12) 1 , X 2 , X 3 and X 4 are each independently >O, >NR, >S, or >Se, and each R in the >NR is independently an aryl having 6 to 12 carbon atoms, a heteroaryl having 2 to 15 carbon atoms, a cycloalkyl having 3 to 12 carbon atoms, or an alkyl having 1 to 6 carbon atoms. In the compound represented by formula (12), from the viewpoint of high TADF properties, Z 1 and Z 2 is preferably diphenylamino which may have a substituent or N-carbazolyl which may have a substituent, and more preferably diphenylamino which may have a substituent. The diphenylamino which may have a substituent is preferably unsubstituted diphenylamino or diphenylamino which has at least one alkyl having 1 to 4 carbon atoms, and more preferably unsubstituted diphenylamino or diphenylamino which has at least one methyl at the m-position or o-position relative to N. From the viewpoint of ease of synthesis and emission wavelength, the aryl ring or heteroaryl ring in ring A, ring B, ring C and ring D is Z 1 and Z 2 It is preferred that the group has no substituents other than Z or has only alkyl having 1 to 6 carbon atoms as other substituents.1 and Z 2 It is more preferred that there are no substitutions other than: Examples of compounds represented by formula (12) are shown below.

[0265] [ka]

[0266] [ka]

[0267] [ka]

[0268] [ka]

[0269] In formula (13) and formula (14), A 11 Ring, A 21 Ring, A 31 Ring, B 11 Ring, B 21 Ring, C 11 ring, and C 31 each ring is independently a substituted or unsubstituted aryl ring or a substituted or unsubstituted heteroaryl ring; Y 11 , Y 21 , Y 31 is B (boron), X 11 , X 12 , X 21 , X 22 , X 31 , and X 32 are each independently >O, >NR, >S, or >Se, and R of the >NR is a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, or a substituted or unsubstituted alkyl, and R of the >NR is connected to A by a linking group or a single bond. 11 Ring, A21 Ring, A 31 Ring, B 11 Ring, B 21 Ring, C 11 ring, and / or C 31 may be attached to a ring, At least one hydrogen atom in the compounds represented by formula (13) and formula (14) may be replaced by cyano, halogen, or deuterium.

[0270] A in Equation (13) and Equation (14) 11 Ring, A 21 Ring, A 31 Ring, B 11 Ring, B 21 Ring, C 11 ring, and C 31 In the above, the substituents when the aryl or heteroaryl ring is substituted and Z 1 , Z 2 Examples of the substituent include a substituent selected from the group Z of substituents.

[0271] X in Equation (13) and Equation (14) 11 , X 12 , X 21 , X 22 , X 31 , and X 32 are each independently >O, >NR, >S, or >Se, and each R in the >NR is independently an aryl having 6 to 12 carbon atoms, a heteroaryl having 2 to 15 carbon atoms, a cycloalkyl having 3 to 12 carbon atoms, or an alkyl having 1 to 6 carbon atoms.

[0272] Examples of the compound represented by formula (13) or formula (14) are shown below. [ka]

[0273] [ka]

[0274] <Thermally activated delayed phosphor (assisting dopant)> The term "thermally activated delayed fluorescent substance" refers to a compound that can absorb thermal energy to undergo reverse intersystem crossing from an excited triplet state to an excited singlet state, and then radiatively deactivate from the excited singlet state to emit delayed fluorescence. However, the term "thermally activated delayed fluorescent substance" also includes compounds that undergo a higher-order triplet state during the excitation process from the excited triplet state to the excited singlet state. Examples include a paper by Monkman et al. of Durham University (NATURE COMMUNICATIONS,7:13680,DOI: 10.1038 / ncomms13680), a paper by Hosokai et al. of the National Institute of Advanced Industrial Science and Technology (Hosokai et al., Sci. Adv. 2017;3: e1603282), a paper by Sato et al. of Kyoto University (Scientific Reports,7:4820,DOI:10.1038 / s41598-017-05007-7), and an academic presentation by Sato et al., also of Kyoto University (98th Annual Meeting of the Chemical Society of Japan, presentation number: 2I4-15, Mechanism of highly efficient light emission in organic electroluminescence using DABNA as the emissive molecule, Kyoto University Graduate School of Engineering). In the present invention, when a sample containing a target compound is measured for its fluorescence lifetime at 300 K, if a slow fluorescent component is observed, the target compound is determined to be a "thermally activated delayed fluorescent substance." Here, a slow fluorescent component refers to a component with a fluorescence lifetime of 0.1 μsec or longer. The fluorescence lifetime can be measured using, for example, a fluorescence lifetime measurement device (manufactured by Hamamatsu Photonics, C11367-01).

[0275] The polycyclic aromatic compound of the present invention having a structure containing a structural unit represented by formula (1A) or formula (1B) can function as an emitting dopant, and the "thermally activated delayed fluorescent substance" can function as an assisting dopant that assists the emission of the polycyclic aromatic compound of the present invention. In the following description, an organic electroluminescent device that uses a thermally activated delayed fluorescent substance as an assisting dopant may be referred to as a "TAF device" (TADF Assisting Fluorescence device). The "host compound" in a TAF element means a compound whose excited singlet energy level, determined from the shoulder on the short-wavelength side of the peak of the fluorescence spectrum, is higher than that of the thermally activated delayed fluorescent substance serving as the assisting dopant and the emitting dopant.

[0276] Figure 2 shows the energy level diagram of the emitting layer of a TAF device using a common fluorescent dopant as the emitting dopant (ED). In the diagram, the ground state energy level of the host is E(1,G), the excited singlet energy level obtained from the shoulder on the short wavelength side of the fluorescence spectrum of the host is E(1,S,Sh), the excited triplet energy level obtained from the shoulder on the short wavelength side of the phosphorescence spectrum of the host is E(1,T,Sh), the ground state energy level of the assisting dopant is E(2,G), the excited singlet energy level obtained from the shoulder on the short wavelength side of the fluorescence spectrum of the assisting dopant is E(2,S,Sh), and the excited triplet energy level obtained from the shoulder on the short wavelength side of the fluorescence spectrum of the assisting dopant is E(2,T,Sh). The excited triplet energy level obtained from the shoulder on the short wavelength side of the spectrum is E(2,T,Sh), the ground state energy level of the emitting dopant is E(3,G), the excited singlet energy level obtained from the shoulder on the short wavelength side of the fluorescence spectrum of the emitting dopant is E(3,S,Sh), the excited triplet energy level obtained from the shoulder on the short wavelength side of the phosphorescence spectrum of the emitting dopant is E(3,T,Sh), the hole is h+, the electron is e-, and fluorescence resonance energy transfer is FRET (Fluorescence Resonance Energy Transfer). In a TAF element, when a general fluorescent dopant is used as the emitting dopant (ED), the energy upconverted by the assisting dopant is transferred to the excited singlet energy level E(3,S,Sh) of the emitting dopant and emits light. However, some of the excited triplet energy E(2,T,Sh) on the assisting dopant transfers to the excited triplet energy level E(3,T,Sh) of the emitting dopant, or intersystem crossing occurs on the emitting dopant from the excited singlet energy level E(3,S,Sh) to the excited triplet energy level E(3,T,Sh), followed by thermal decay to the ground state E(3,G). This pathway results in a waste of energy, as some of the energy is not used for light emission.

[0277] In contrast, in the organic electroluminescent device of this embodiment, the energy transferred from the assisting dopant to the emitting dopant can be efficiently utilized for light emission, thereby achieving high luminous efficiency. This is presumably due to the following luminescence mechanism. A preferred energy relationship in the organic electroluminescent device of this embodiment is shown in Figure 3. In the organic electroluminescent device of this embodiment, the compound having a boron atom as the emitting dopant has a high excited triplet energy level E(3,T,Sh). Therefore, even if the excited singlet energy upconverted by the assisting dopant undergoes intersystem crossing to the excited triplet energy level E(3,T,Sh) in the emitting dopant, it is either upconverted on the emitting dopant or recovered to the excited triplet energy level E(2,T,Sh) on the assisting dopant (thermally activated delayed fluorescent material). Therefore, the generated excited energy can be used for emission without waste. Furthermore, by dividing the upconversion and emission functions into two types of molecules each specializing in each function, the residence time of the high energy is reduced, which is expected to reduce the burden on the compound. In this embodiment, known host compounds can be used, such as compounds having at least one of a carbazole ring and a furan ring. Among them, it is preferable to use a compound in which at least one of a furanyl group and a carbazolyl group is bonded to at least one of an arylene group and a heteroarylene group. Specific examples include mCP and mCBP.

[0278] The triplet energy level E(1,T,Sh), determined from the shoulder on the short-wavelength side of the peak of the phosphorescence spectrum of the host compound, is preferably higher than the triplet energy levels E(2,T,Sh) and E(3,T,Sh) of the emitting dopant or assisting dopant having the highest triplet energy level in the emitting layer, from the viewpoint of promoting TADF generation without inhibiting it. Specifically, the triplet energy level E(1,T,Sh) of the host compound is preferably higher than E(2,T,Sh) and E(3,T,Sh) by 0.01 eV or more, more preferably by 0.03 eV or more, and even more preferably by 0.1 eV or more. A TADF-active compound may also be used as the host compound.

[0279] The thermally activated delayed phosphor (TADF compound) used in the TAF element is preferably a donor-acceptor type thermally activated delayed phosphor (DA type TADF compound) designed to localize the HOMO (highest occupied molecular orbital) and LUMO (lowest unoccupied molecular orbital) within the molecule using an electron-donating substituent called a donor and an electron-accepting substituent called an acceptor, thereby causing efficient reverse intersystem crossing.

[0280] In this specification, the term "electron-donating substituent" (donor) refers to a substituent or partial structure in which the HOMO orbital is localized in the thermally activated delayed fluorescent substance molecule, and the term "electron-accepting substituent" (acceptor) refers to a substituent or partial structure in which the LUMO orbital is localized in the thermally activated delayed fluorescent substance molecule.

[0281] In general, thermally activated delayed fluorescent materials using donors and acceptors have large spin-orbit coupling (SOC) due to their structure, and small exchange interaction between HOMO and LUMO, resulting in a low ΔE S1T1On the other hand, thermally activated delayed fluorescent materials using donors or acceptors exhibit large structural relaxation in the excited state (in some molecules, the stable structure differs between the ground state and the excited state, so when an external stimulus causes a transition from the ground state to the excited state, the structure subsequently changes to the stable structure in the excited state), which gives a wide emission spectrum and may reduce color purity when used as an emitting material.

[0282] As the thermally activated 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 electron accepting group (acceptor structure) used in the thermally activated delayed phosphor of the present invention, for example, the structure described in Chemistry of Materials, 2017, 29, 1946-1963 can be used. Donor structures include carbazole, dimethylcarbazole, di-tert-butylcarbazole, dimethoxycarbazole, tetramethylcarbazole, benzofluorocarbazole, benzothienocarbazole, phenyldihydroindolocarbazole, phenylbicarbazole, bicarbazole, tercarbazole, diphenylcarbazolylamine, tetraphenylcarbazolyldiamine, phenoxazine, dihydrophenazine, phenothiazine, dimethyldihydroacridine, diphenylamine, bis(tert-butylphenyl)amine, N1-(4-(diphenylamino)phenyl)-N4,N4-diphenylbenzene-1,4-diamine, dimethyltetraphenyldihydroacridinediamine, tetramethyl-dihydroindenoacridine, and diphenyl-dihydrodibenzazasiline.Acceptor structures include sulfonyldibenzene, benzophenone, phenylenebis(phenylmethanone), benzonitrile, isonicotinonitrile, phthalonitrile, isophthalonitrile, paraphthalonitrile, benzenetricarbonitrile, triazole, oxazole, thiadiazole, benzothiazole, benzobis(thiazole), benzoxazole, benzobis(oxazole), quinoline, benzimidazole, dibenzoquinoxaline, heptaazaphenalene, thioxanthone dioxide, dimethylanthracenone, anthracenedione, 5H-cyclopenta[1,2-b:5,4-b']dipyridine, fluorene dicarbonitrile, triphenyltriazine, pyrazinedicarbonitrile, pyrimidine, phenylpyrimidine, methylpyrimidine, pyridinedicarbonitrile, dibenzoquinoxalinedicarbonitrile, bis(phenylsulfonyl)benzene, dimethylthioxanthene dioxide, thianthrene tetraoxide, and tris(dimethylphenyl)borane. In particular, the compound having thermally activated delayed fluorescence in the TAF element is preferably a compound having at least one partial structure selected from carbazole, phenoxazine, acridine, triazine, pyrimidine, pyrazine, thioxanthene, benzonitrile, phthalonitrile, isophthalonitrile, diphenylsulfone, triazole, oxadiazole, thiadiazole, and benzophenone.

[0283] The compound used as the assisting dopant in the light-emitting layer of the TAF element is preferably a thermally activated delayed phosphor, the emission spectrum of which at least partially overlaps with the absorption peak of the emitting dopant.

[0284] <Phosphorescent materials (assisting dopants)> In the light-emitting layer, a phosphorescent material may be used as an assisting dopant. The phosphorescent material utilizes the intramolecular spin-orbit interaction (heavy atom effect) of a metal atom to obtain light emission from triplets. For example, a luminescent metal complex can be used as such a phosphorescent material. Examples of the luminescent metal complex include compounds represented by the following formula (B-1) and formula (B-2).

[0285] [ka]

[0286] 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 each "XY" is independently a bidentate ligand. 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. In the formula (B-1), M is preferably Ir and n is preferably 3 from the viewpoints of efficiency and life. In the formula (B-2), M is preferably Pt from the viewpoint of efficiency and life. 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:

[0287] [ka]

[0288] During the ceremony, --- binds to the central metal M, Y is independently BR e , N.R. e , PR e , O, S, Se, C=O, S=O, SO2, CR e R f , SiRe R f , or GeR e R f and Each aromatic carbon atom CH in the ring may be independently substituted with N; R e and R f may be optionally fused or linked to form a ring, R a , R b , R c , and R d may each independently be unsubstituted or substituted with from 1 to the maximum possible number of substitutions, R a , R b , R c , R d , R e , and R f are each independently hydrogen, deuterium, halide, alkyl, cycloalkyl, heteroalkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, aryl, heteroaryl, nitrile, isonitrile, sulfanyl, or a combination thereof; However, R a , R b , R c , and R d Any two adjacent substituents in may be fused or linked to form a ring or to form a multidentate ligand.

[0289] 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), 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.

[0290] Other examples of the compound represented by formula (B-1) include the following compounds: [ka]

[0291] [ka]

[0292] [ka]

[0293] In addition, iridium complexes described in JP 2006-089398 A, JP 2006-080419 A, JP 2005-298483 A, JP 2005-097263 A, and JP 2004-111379 A, ​​U.S. Patent Application Publication No. 2019 / 0051845, or Advanced Materials, 26: 7116-7121, NPG Asia Materials 13, 53 (2021), Applied Physics Letters, 117, 253301 (2020), Light-Emitting Diode - An Outlook On the Empirical Features and Its Recent Technological Advancements, Chapter 5 Platinum complexes described may also be used.

[0294] 2-1-6. Electron injection layer and electron transport layer in organic electroluminescent devices The electron injection layer 107 plays a role of efficiently injecting electrons moving 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 each formed by laminating or mixing one or more electron transport / injection materials, or by a mixture of an electron transport / injection material and a polymer binder.

[0295] The electron injection / transport layer is a layer responsible for injecting electrons from the cathode and transporting them. It is desirable for the layer to have high electron injection efficiency and efficiently transport the injected electrons. To achieve this, it is preferable for the material to have high electron affinity, high electron mobility, excellent stability, and be less likely to generate trapping impurities during manufacture and use. However, considering the balance between hole and electron transport, if a material primarily serves to efficiently block holes from the anode from flowing to the cathode without recombining, it can have the same effect of improving luminous efficiency as a material with high electron transport ability, even if it does not have a particularly high electron transport ability. Therefore, the electron injection / transport layer in this embodiment may also function as a layer that can efficiently block the movement of holes.

[0296] 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 transport compounds in photoconductive materials and known compounds used in electron injection layers and electron transport layers of organic EL devices.

[0297] Materials used in the electron transport layer or electron injection layer preferably contain at least one selected from the group consisting of aromatic or heteroaromatic ring compounds composed of one or more atoms selected from carbon, hydrogen, oxygen, sulfur, silicon, and phosphorus; pyrrole derivatives and their fused ring derivatives; and metal complexes containing electron-accepting nitrogen. Specific examples include fused ring aromatic derivatives such as naphthalene and anthracene; styryl aromatic derivatives such as 4,4'-bis(diphenylethenyl)biphenyl; perinone derivatives; coumarin derivatives; naphthalimide derivatives; quinone derivatives such as anthraquinone and diphenoquinone; phosphorus oxide derivatives; arylnitrile derivatives; and indole derivatives. Examples of metal complexes containing electron-accepting nitrogen include hydroxyazole complexes such as hydroxyphenyloxazole complexes, azomethine complexes, tropolone metal complexes, flavonol metal complexes, and benzoquinoline metal complexes. These materials can be used alone or in combination with other materials.

[0298] Specific examples of other electron transport compounds include pyridine derivatives, naphthalene derivatives, anthracene derivatives, phenanthroline derivatives, perinone derivatives, coumarin derivatives, naphthalimide derivatives, anthraquinone derivatives, diphenoquinone derivatives, diphenylquinone derivatives, perylene derivatives, oxadiazole derivatives (e.g., 1,3-bis[(4-t-butylphenyl)1,3,4-oxadiazolyl]phenylene), thiophene derivatives, triazole derivatives (e.g., N-naphthyl-2,5-diphenyl-1,3,4-triazole), thiadiazole derivatives, metal complexes of oxine derivatives, quinolinol-based metal complexes, quinoxaline derivatives, polymers of quinoxaline derivatives, benzazole compounds, gallium complexes, pyrazole derivatives, perfluorinated phenylene derivatives, triazine derivatives, pyrazine derivatives, and the like. Examples of the compound include benzoquinolin-2-yl-9,9'-spirobifluorene, benzoxazole derivatives, benzothiazole derivatives, quinoline derivatives, oligopyridine derivatives such as terpyridine, bipyridine derivatives, terpyridine derivatives (1,3-bis(2,2':6',2"-terpyridin-4'-yl)benzene, naphthyridine derivatives (bis(1-naphthyl)-4-(1,8-naphthyridin-2-yl)phenylphosphine oxide, etc.), aldazine derivatives, carbazole derivatives, indole derivatives, phosphine oxide derivatives, and bisstyryl derivatives.

[0299] Metal complexes having an electron-accepting nitrogen atom can also be used, and examples thereof include hydroxyazole complexes such as quinolinol metal complexes and hydroxyphenyloxazole complexes, azomethine complexes, tropolone metal complexes, flavonol metal complexes, and benzoquinoline metal complexes.

[0300] The above-mentioned materials may be used alone or in combination with other materials.

[0301] Among the above-mentioned materials, borane derivatives, pyridine derivatives, fluoranthene derivatives, BO-based derivatives, anthracene derivatives, benzofluorene derivatives, phosphine oxide derivatives, pyrimidine derivatives, arylnitrile derivatives, triazine derivatives, benzimidazole derivatives, phenanthroline derivatives, and quinolinol-based metal complexes are preferred.

[0302] The electron transport layer or the electron injection layer may further contain a substance capable of reducing the material forming the electron transport layer or the electron injection layer. Various substances can be used as this reducing substance as long as they have a certain level of reducing ability. 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 suitably used.

[0303] Preferred reducing substances include alkali metals such as Na (work function 2.36 eV), K (2.28 eV), Rb (2.16 eV), and Cs (1.95 eV), and alkaline earth metals such as Ca (2.9 eV), Sr (2.0-2.5 eV), and Ba (2.52 eV), with substances with a work function of 2.9 eV or less being particularly preferred. Among these, more preferred reducing substances are alkali metals such as K, Rb, and Cs, with Rb or Cs being even more preferred, and Cs being the most preferred. These alkali metals have particularly high reducing ability, and adding a relatively small amount of these metals to the material forming the electron transport layer or electron injection layer can improve the luminance and extend the life of the organic EL device. Furthermore, as a 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 in particular, a combination containing Cs is preferred, such as a combination of Cs and Na, Cs and K, Cs and Rb, or Cs, Na and K. By including Cs, the reducing ability can be efficiently exerted, and by adding Cs to the material forming the electron transport layer or electron injection layer, the luminance of the organic EL device can be improved and the lifetime can be extended.

[0304] 2-1-7. Cathode in organic electroluminescent devices The cathode 108 serves to inject electrons into the light-emitting layer 105 through the electron injection layer 107 and the electron transport layer 106 .

[0305] The material for the cathode 108 is not particularly limited as long as it can efficiently inject electrons into the organic layer, but materials similar to those for the anode 102 can be used. Among these, metals such as tin, indium, calcium, aluminum, silver, copper, nickel, chromium, gold, platinum, iron, zinc, lithium, sodium, potassium, cesium, and magnesium, or alloys thereof (e.g., magnesium-silver alloys, magnesium-indium alloys, and aluminum-lithium alloys such as lithium fluoride / aluminum alloys), are preferred. To increase electron injection efficiency and improve device characteristics, lithium, sodium, potassium, cesium, calcium, magnesium, or alloys containing these low-work-function metals are effective. However, these low-work-function metals are generally unstable in air. To address this issue, a method has been proposed in which a trace amount of lithium, cesium, or magnesium is doped into the organic layer to create a highly stable electrode. Other dopants that can be used include inorganic salts such as lithium fluoride, cesium fluoride, lithium oxide, and cesium oxide. However, these are not limited to these.

[0306] Further, for electrode protection, preferred examples include lamination of metals such as platinum, gold, silver, copper, iron, tin, aluminum, and indium, or alloys using these metals, inorganic materials such as silica, titania, and silicon nitride, polyvinyl alcohol, vinyl chloride, hydrocarbon polymer compounds, etc. The method for producing these electrodes is not particularly limited as long as electrical conduction can be achieved, and may include resistance heating, electron beam evaporation, sputtering, ion plating, and coating.

[0307] 2-1-8. Method for producing organic electroluminescent device Each layer constituting an organic EL device can be formed by forming the material to be formed into a thin film using methods such as vapor deposition, resistance heating vapor deposition, electron beam vapor deposition, sputtering, molecular lamination, printing, spin coating or casting, and coating. There are no particular limitations on the film thickness of each layer formed in this way, and it can be set appropriately depending on the properties of the material, but it is usually in the range of 2 nm to 5000 nm. The film thickness can usually be measured with a quartz oscillator film thickness measuring device or the like. When forming a thin film using vapor deposition, the vapor deposition conditions vary depending on the type of material, the desired crystal structure and association structure of the film, etc. Vapor deposition conditions are generally a boat heating temperature of +50 to +400°C, a vacuum degree of 10 -6 ~10 -3 It is preferable to appropriately set the pressure, the deposition rate, the substrate temperature, and the film thickness in the range of 0.01 to 50 nm / sec, -150 to +300° C., and 2 nm to 5 μm.

[0308] When applying a DC voltage to the organic EL element obtained in this way, the anode should be set to + and the cathode to -. When a voltage of about 2 to 40 V is applied, light emission can be observed from the transparent or semi-transparent electrode side (anode or cathode, or both). This organic EL element also emits light when a pulse current or an AC current is applied. The waveform of the applied AC current can be any waveform.

[0309] Next, as an example of a method for producing an organic EL element, a method for producing an organic EL element comprising an anode, a hole injection layer, a hole transport layer, an emitting layer composed of a host material and a dopant material, an electron transport layer, an electron injection layer, and a cathode will be described.

[0310] <Vapor deposition method> An anode is prepared by forming a thin film of an anode material on a suitable substrate by vapor deposition or the like, and then forming thin films of a hole injection layer and a hole transport layer on the anode. A host material and a dopant material are co-deposited on the anode to form a thin film to serve as an emissive layer. An electron transport layer and an electron injection layer are then formed on the emissive layer, and a thin film of a cathode material is then formed by vapor deposition or the like to serve as a cathode, thereby obtaining the desired organic EL device. It is also possible to reverse the order of fabrication of the organic EL device described above, by fabricating the layers in the order of cathode, electron injection layer, electron transport layer, emissive layer, hole transport layer, hole injection layer, and anode.

[0311] <Wet film formation method> The wet film formation method is carried out by preparing a liquid organic layer-forming composition from a low molecular weight compound capable of forming each organic layer of an organic EL device, and using this. If there is no suitable organic solvent that can dissolve this low molecular weight compound, the organic layer-forming composition may be prepared from a reactive compound obtained by substituting a reactive substituent on the low molecular weight compound, such as another monomer having a solubility function as a reactive compound, or a polymer compound polymerized together with a main-chain polymer.

[0312] In wet film formation, a coating film is generally formed through a coating step in which an organic layer-forming composition is applied to a substrate and a drying step in which the solvent is removed from the applied organic layer-forming composition. When the polymer compound has a crosslinkable substituent (also called a crosslinkable polymer compound), the drying step further crosslinks the polymer to form a crosslinked polymer. Depending on the coating process, methods using a spin coater are called spin coating methods; methods using a slit coater are called slit coating methods; methods using a printing plate are called gravure, offset, reverse offset, or flexographic printing methods; methods using an inkjet printer are called inkjet methods; and methods spraying the composition in a mist are called spray methods. Drying methods include air drying, heating, and vacuum drying. The drying process may be performed once or multiple times using different methods and conditions. Different methods, such as baking under reduced pressure, may also be used in combination.

[0313] Wet film formation methods are film formation methods that use solutions, such as some printing methods (inkjet methods), spin coating or casting methods, and coating methods. Unlike vacuum deposition methods, wet film formation methods do not require expensive vacuum deposition equipment and can form films under atmospheric pressure. In addition, wet film formation methods allow for large-area and continuous production, which leads to reduced manufacturing costs.

[0314] On the other hand, compared to vacuum deposition, wet deposition can be difficult to layer. When using wet deposition to create layered films, it is necessary to prevent the dissolution of the lower layer by the composition of the upper layer, and methods such as controlled solubility compositions, crosslinking of the lower layer, and orthogonal solvents (solvents that are not soluble in each other) are used. However, even with these techniques, it can be difficult to use wet deposition for all film application.

[0315] Therefore, a common method for fabricating organic EL devices is to use a wet film-forming method for only some layers and a vacuum deposition method for the remaining layers.

[0316] For example, the procedure for producing an organic EL element by partially applying a wet film formation method is shown below. (Step 1) Formation of the anode by vacuum deposition (Step 2) Forming a film by a wet film formation method using a composition for forming a hole injection layer containing a material for the hole injection layer (Step 3) Forming a film by a wet film formation method using a composition for forming a hole transport layer containing a material for the hole transport layer (Step 4) Forming a film by a wet film formation method using a composition for forming an emitting layer containing a host material and a dopant material (Step 5) Formation of the electron transport layer by vacuum deposition (Step 6) Formation of the electron injection layer by vacuum deposition (Step 7) Cathode deposition by vacuum evaporation Through this procedure, an organic EL element consisting of an anode, a hole injection layer, a hole transport layer, a light-emitting layer made of a host material and a dopant material, an electron transport layer, an electron injection layer, and a cathode is obtained. Of course, the electron transport layer and the electron injection layer may also be formed by a wet film formation method using layer-forming compositions containing the electron transport layer material and the electron injection layer material, respectively. In this case, it is preferable to use a method to prevent dissolution of the underlying light-emitting layer or a method to form the layer from the cathode side, in the reverse order of the above procedure.

[0317] <Other film formation methods> The organic layer-forming composition can be formed into a film by laser thermal imaging (LITI), a method in which a compound attached to a substrate is heated and vapor-deposited with a laser, and the organic layer-forming composition can be used as the material applied to the substrate.

[0318] <Optional process> Before and after each film-forming step, appropriate treatment steps, cleaning steps, and drying steps may be added as appropriate. Examples of treatment steps include exposure treatment, plasma surface treatment, ultrasonic treatment, ozone treatment, cleaning treatment using an appropriate solvent, and heat treatment. Furthermore, a series of steps for preparing a bank may also be included.

[0319] Photolithography can be used to fabricate the banks. Positive and negative resist materials can be used as bank materials for photolithography. Patternable printing methods such as inkjet printing, gravure offset printing, reverse offset printing, and screen printing can also be used. In these cases, permanent resist materials can also be used.

[0320] <Composition for forming organic layer used in wet film formation method> The organic layer-forming composition is obtained by dissolving a low-molecular-weight compound capable of forming each organic layer of an organic EL device, or a polymer compound obtained by polymerizing such a low-molecular-weight compound, in an organic solvent. For example, the light-emitting layer-forming composition contains at least one polycyclic aromatic compound (or a polymer compound thereof) as a dopant material as a first component, at least one host material as a second component, and at least one organic solvent as a third component. The first component functions as a dopant component for the light-emitting layer obtained from the composition, and the second component functions as a host component for the light-emitting layer. The third component functions as a solvent that dissolves the first and second components in the composition, and upon application, the controlled evaporation rate of the third component itself provides a smooth and uniform surface profile.

[0321] <Organic solvents> The organic layer-forming composition contains at least one organic solvent. By controlling the evaporation rate of the organic solvent during film formation, it is possible to control and improve film-forming properties, the presence or absence of defects in the coating film, surface roughness, and smoothness. Furthermore, when forming a film using an inkjet method, it is possible to control meniscus stability at the pinhole of the inkjet head and control and improve ejection properties. In addition, by controlling the drying rate of the film and the orientation of the derivative molecules, it is possible to improve the electrical properties, luminescence properties, efficiency, and lifespan of an organic EL device having an organic layer obtained from the organic layer-forming composition.

[0322] After film formation, the organic solvent is removed from the coating film by a drying process such as vacuum, reduced pressure, or heating. When heating is performed, from the viewpoint of improving coating film-forming properties, it is preferable to perform the heating at a temperature not higher than 30°C above the glass transition temperature (Tg) of at least one of the solutes. Furthermore, from the viewpoint of reducing residual solvent, it is preferable to perform the heating at a temperature not lower than 30°C below the glass transition temperature (Tg) of at least one of the solutes. Even if the heating temperature is lower than the boiling point of the organic solvent, the organic solvent can be sufficiently removed because the film is thin. Furthermore, drying may be performed multiple times at different temperatures, or multiple drying methods may be used in combination.

[0323] (2) Specific examples of organic solvents Examples of organic solvents used in the organic layer-forming composition include, but are not limited to, 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. The solvents may be used alone or in combination.

[0324] <Optional ingredients> The composition for forming the organic layer may contain optional components, such as a binder and a surfactant, to the extent that the properties of the composition are not impaired.

[0325] <Composition and Properties of the Organic Layer-Forming Composition> The content of each component in the composition for forming an organic layer is determined taking into consideration the good solubility, storage stability, and film-forming properties of each component in the composition for forming an organic layer, as well as the good film quality of the coating film obtained from the composition for forming an organic layer, good ejection properties when an inkjet method is used, and good electrical properties, light-emitting properties, efficiency, and lifespan of an organic EL element having an organic layer produced using the composition.

[0326] The composition for forming an organic layer can be produced by appropriately selecting the above-mentioned components by a known method, such as stirring, mixing, heating, cooling, dissolving, dispersing, etc. After preparation, the composition may be appropriately subjected to filtration, degassing (also called degassing), ion exchange treatment, inert gas substitution / filling treatment, etc.

[0327] 2-1-9.Application examples of organic electroluminescent devices The present invention can also be applied to a display device having an organic EL element or a lighting device having an organic EL element. A display device or lighting device including an organic EL element can be manufactured by a known method, for example, by connecting the organic EL element according to this embodiment to a known driving device, and can be driven appropriately using a known driving method such as DC driving, pulse driving, or AC driving.

[0328] Examples of display devices include panel displays such as color flat panel displays, and flexible displays such as flexible color organic electroluminescent (EL) displays (see, for example, JP-A-10-335066, JP-A-2003-321546, and JP-A-2004-281086). Examples of display methods include matrix and segment methods. Note that matrix display and segment display may coexist on the same panel.

[0329] In a matrix display, pixels are arranged two-dimensionally, such as in a grid or mosaic pattern, and a collection of pixels displays characters and images. The shape and size of the pixels are determined by the application. For example, images and text displayed on computers, monitors, and televisions typically use square pixels with sides of 300 μm or less. Large displays such as display panels use pixels on the order of millimeters. For monochrome displays, pixels of the same color are simply arranged, while for color displays, red, green, and blue pixels are displayed side by side. These types are typically known as delta and stripe types. The matrix can be driven by either line-sequential or active matrix methods. While line-sequential driving has the advantage of being simpler, active matrix methods can sometimes be superior in terms of operating characteristics, so the choice must be made based on the application.

[0330] In the segment type, a pattern is formed to display predetermined information, and a predetermined area is illuminated. Examples include the time and temperature displays on digital clocks and thermometers, the operating status displays on audio equipment and induction cookers, and panel displays on automobiles.

[0331] Examples of lighting devices include lighting devices for indoor lighting and backlights for liquid crystal display devices (see, for example, JP 2003-257621 A, JP 2003-277741 A, JP 2004-119211 A, etc.). Backlights are primarily used to improve the visibility of non-self-luminous display devices, and are used in liquid crystal display devices, clocks, audio devices, automobile panels, display boards, signs, etc. In particular, for backlights for liquid crystal display devices, particularly for personal computers where thinning is an issue, considering that conventional systems use fluorescent lamps and light guide plates and therefore make thinning difficult, backlights using the light-emitting elements according to this embodiment are characterized by their thinness and light weight.

[0332] 2-2. Other organic devices The polycyclic aromatic compound according to the present invention can be used to produce not only the above-mentioned organic electroluminescent device but also an organic field effect transistor or an organic thin-film solar cell. [Example]

[0333] The present invention will be explained in more detail below with reference to examples, but the present invention is not limited to these examples.

[0334] Synthesis example (1): Synthesis of compound (1-1) [ka]

[0335] Compound (I-1) was synthesized with reference to Organic Letters (2011), 13(24), 6516-6519.

[0336] 1st process A 1.6 M tert-butyllithium pentane solution (1.6 ml) was added to a flask containing compound (I-1) (0.62 g) and tert-butylbenzene (7.0 ml) under a nitrogen atmosphere at -30°C. After the dropwise addition, the mixture was heated to 60°C and stirred for 2 hours, after which components with a boiling point lower than that of tert-butylbenzene were distilled off under reduced pressure. The mixture was cooled to -30°C, boron tribromide (0.63 g) was added, and the mixture was heated to room temperature and stirred for 0.5 hours. The mixture was then cooled again to 0°C, and N,N-diisopropylethylamine (0.43 ml) was added. The mixture was stirred at room temperature until the heat generation subsided, then heated to 120°C and stirred for 3 hours. The reaction mixture was cooled to room temperature, and aqueous sodium acetate solution cooled in an ice bath, followed by heptane, was added and the mixture was separated. Next, after purifying with a silica gel short-path column (eluent: toluene), the solvent was distilled off under reduced pressure, and the resulting solid was dissolved in toluene and reprecipitated by adding heptane to obtain compound (I-2) (0.15 g).

[0337] Synthesis of compound (1-1) A flask containing compound (I-2) (0.15 g), aniline (0.026 g), potassium carbonate (0.138 g), and acetonitrile (5.0 ml) was heated to reflux for 5 hours, and then low-boiling components were distilled off under reduced pressure at 40° C. Water and toluene were added, and the mixture was separated. After purification using a silica gel short-path column (eluent: toluene), the solvent was distilled off under reduced pressure. The resulting solid was dissolved in toluene, reprecipitated by adding heptane, and then purified by sublimation to obtain 0.06 g of compound (1-1). LC-MS: [M+H] + =672.33

[0338] Synthesis example (2): Synthesis of compound (1-2) [ka]

[0339] It was synthesized in the same manner as in Synthesis Example (1). Compound (I-3) was synthesized with reference to JP-A-2013-187419. LC-MS: [M+H] +=822.40

[0340] Synthesis example (3): Synthesis of Compound (1-3) [ka]

[0341] It was synthesized in the same manner as in Synthesis Example (1). Compound (I-5) was synthesized with reference to JP-A-2013-187419. LC-MS: [M+H] + =738.50

[0342] Synthesis example (4): Synthesis of Compound (1-4) [ka]

[0343] It was synthesized in the same manner as in Synthesis Example (1). Compound (I-7) was synthesized with reference to Korean Patent Publication No. 10-2014-0074858. LC-MS: [M+H] + =686.46

[0344] Synthesis example (5): Synthesis of Compound (1-5) [ka]

[0345] Compound (I-9) was synthesized in the same manner as in Synthesis Example (1). A flask containing compound (I-9) (0.13 g) and tert-butylbenzene (2.0 ml) was cooled to 0 °C under a nitrogen atmosphere, and boron tribromide (0.30 g) was added. The mixture was then warmed to room temperature and stirred for 1 hour. After cooling to 0 °C again, N,N-diisopropylethylamine (0.20 ml) was added, and the mixture was stirred at room temperature until the exotherm subsided. The mixture was then heated to 80 °C and stirred for 3 hours. The reaction mixture was then cooled to room temperature, and an ice-bath-cooled aqueous sodium acetate solution was added, followed by heptane, followed by phase separation. The mixture was then purified using a silica gel short-path column (eluent: toluene). The solvent was then removed under reduced pressure, and the resulting solid was dissolved in toluene, reprecipitated with heptane, and purified by sublimation to obtain compound (1-5) (0.03 g). LC-MS: [M+H] + =597.28

[0346] Synthesis example (6): Synthesis of Compound (1-6) [ka]

[0347] A flask containing compound (I-2) (0.15 g), sodium methanethiol (0.037 g), and dimethylformamide (5.0 ml) was heated to reflux at 80°C for 3 hours, and then water and toluene were added to separate the solution. The mixture was purified using a silica gel short-path column (eluent: toluene), and the solvent was then distilled off under reduced pressure. The resulting solid was dissolved in toluene, reprecipitated by adding heptane, and then purified by sublimation to obtain 0.07 g of compound (1-6). LC-MS: [M+H] + =613.26

[0348] Synthesis example (7): Synthesis of Compound (1-7) [ka]

[0349] It was synthesized in the same manner as in Synthesis Example (1). Compound (I-10) was synthesized with reference to Organic Letters (2011), 13(24), 6516-6519. LC-MS: [M+H] + =712.27

[0350] Synthesis example (8): Synthesis of Compound (1-8) [ka]

[0351] It was synthesized in the same manner as in Synthesis Example (1). Compound (I-12) was synthesized with reference to JP-A-2013-187419. LC-MS: [M+H] + =862.34

[0352] By appropriately changing the starting compounds, other compounds of the present invention can be synthesized in accordance with the methods of the above synthesis examples.

[0353] <Evaluation of organic EL elements> Evaluation items and evaluation methods Evaluation items include driving voltage (V), emission wavelength (nm), CIE chromaticity (x, y), external quantum efficiency (%), maximum wavelength (nm) and half-width (nm) of the emission spectrum, etc. For these evaluation items, values ​​at appropriate emission luminance can be used.

[0354] The quantum efficiency of a light-emitting element can be classified into internal quantum efficiency and external quantum efficiency, and the internal quantum efficiency indicates the rate at which external energy injected as electrons (or holes) into the light-emitting layer of the light-emitting element is converted purely into photons. On the other hand, the external quantum efficiency is calculated based on the amount of these photons that are emitted to the outside of the light-emitting element, and since some of the photons generated in the light-emitting layer are absorbed or continue to be reflected inside the light-emitting element and are not emitted to the outside of the light-emitting element, the external quantum efficiency is lower than the internal quantum efficiency.

[0355] The spectral radiance (emission spectrum) and external quantum efficiency were measured as follows. The device was irradiated by applying a voltage using an Advantest R6144 voltage / current generator. The spectral radiance in the visible light region was measured perpendicular to the light-emitting surface using a TOPCON SR-3AR spectroradiometer. Assuming the light-emitting surface is a perfectly diffusing surface, the measured spectral radiance value for each wavelength component was divided by the wavelength energy and multiplied by π to obtain the number of photons at each wavelength. The number of photons was then integrated over the entire observed wavelength range to obtain the total number of photons emitted from the device. The applied current value was divided by the elementary charge to obtain the number of carriers injected into the device. The external quantum efficiency was calculated by dividing the total number of photons emitted from the device by the number of carriers injected into the device. The half-width of the emission spectrum was calculated as the width between the wavelengths above and below the maximum emission wavelength at which the intensity was 50%.

[0356] Next, the preparation and evaluation of an organic EL device using the polycyclic aromatic compound of the present invention will be described.

[0357] <Examples 1-1 to 1-8 and Comparative Example 1> The material composition of each layer in each organic EL device is shown in Table 1 below. [Table 1]

[0358] In Table 1, "HI" stands for N 4 ,N 4' -diphenyl-N 4 ,N 4'-bis(9-phenyl-9H-carbazol-3-yl)-[1,1'-biphenyl]-4,4'-diamine, "HAT-CN" is 1,4,5,8,9,12-hexaazatriphenylene hexacarbonitrile, "HT-1" is N-([1,1'-biphenyl]-4-yl)-9,9-dimethyl-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9H-fluoren-2-amine, and "HT-2" is N,N-bis(4-(dibenzo[b,d]furan-4-yl) "BH" is 2-(10-phenylanthracen-9-yl)dibenzo[b,d]furan; "ET-1" is 9,9'-[(5-(6-(1,1'-biphenyl)-4-yl)-2-phenylpyrimidin-4-yl)-1,3-phenylene]bis(9H-carbazole); and "ET-2" is 2-ethyl-1-(4-(10-phenylanthracen-9-yl)phenyl)-1H-benzo[d]imidazole. The chemical structures of "Liq" and comparative compound (1) (a compound described in WO 2015 / 102118) are shown below.

[0359] [ka]

[0360] (Example 1-1) A 26 mm × 28 mm × 0.7 mm glass substrate (manufactured by Optoscience Co., Ltd.) on which an ITO film was formed to a thickness of 180 nm by sputtering and polished to 150 nm was used as a transparent support substrate. This transparent support substrate was fixed to the substrate holder of a commercially available evaporation system (manufactured by Showa Vacuum Co., Ltd.), and molybdenum evaporation boats containing HI, HAT-CN, HT-1, HT-2, BH, compound (1-1), ET-1, and ET-2, and aluminum nitride evaporation boats containing Liq, LiF, and aluminum, respectively, were attached.

[0361] The following layers are formed in order on the ITO film of the transparent support substrate. -4The pressure was reduced to 10 Pa, and HI was first heated and evaporated to a thickness of 40 nm. Next, HAT-CN was heated and evaporated to a thickness of 5 nm. Next, HT-1 was heated and evaporated to a thickness of 45 nm. Next, HT-2 was heated and evaporated to a thickness of 10 nm, forming four layers of hole injection layers 1 and 2 and hole transport layers 1 and 2. Next, BH and compound (1-1) were heated simultaneously and evaporated to a thickness of 25 nm to form an emitting layer. The evaporation rate was adjusted so that the mass ratio of BH to compound (1-1) was approximately 97:3. Next, ET-1 was heated and evaporated to a thickness of 5 nm. Next, ET-2 and Liq were heated simultaneously and evaporated to a thickness of 25 nm to form a two-layer electron transport layer. The evaporation rate was adjusted so that the mass ratio of ET-2 to Liq was approximately 50:50. The evaporation rate for each layer was 0.01 to 1 nm / s. Thereafter, LiF was heated and evaporated at a deposition rate of 0.01 to 0.1 nm / sec to a thickness of 1 nm, and then aluminum was heated and evaporated to a thickness of 100 nm to form a cathode, thereby obtaining an organic EL device.

[0362] (Examples 1-2 to 1-8, Comparative Example 1) An organic EL device was obtained in the same manner as in Example 1-1, except that the compound shown in Table 1 was used instead of the compound (1-1).

[0363] (evaluation) For the organic EL elements of Examples 1-1 to 1-6 and Comparative Example 1, the luminance was 1000 cd / m 2 External quantum efficiency (EQE) and LT95 (initial luminance 1000 cd / m 2 950cd / m when continuously driven at a current density of 2 The time it took for the liquid to become solid was measured. The results are shown in Table 2.

[0364] [Table 2]

[0365] Examples 1-1 to 1-8 exhibited higher efficiency and longer life than Comparative Example 1. Examples using compounds (1-1) to (1-4) having multiple alkyls in the structure and where X is >N-Ph as dopants exhibited high efficiency. On the other hand, examples using compounds (1-5) to (1-8) having no alkyls in the structure or where X is >O or >S as dopants exhibited long life.

[0366] <Examples 2-1 to 2-4 and Comparative Examples 2-1 to 2-2> The material composition of each layer in each organic EL device is shown in Table 3 below.

[0367] [Table 3]

[0368] (Comparative Example 2-1) A 26 mm × 28 mm × 0.7 mm glass substrate (manufactured by Optoscience Co., Ltd.) on which a 200 nm thick ITO film was formed by sputtering and polished to 50 nm was used as a transparent support substrate. This transparent support substrate was fixed to the substrate holder of a commercially available evaporation system (manufactured by Showa Vacuum Co., Ltd.), and molybdenum evaporation boats containing HAT-CN, HTL-1, TcTa, ETL-1, and ET7, respectively, and tungsten evaporation boats containing LiF and aluminum, respectively, were attached.

[0369] The following layers were formed in order on the ITO film of the transparent support substrate. -4The pressure was reduced to 10 Pa, and HAT-CN was heated and evaporated to a thickness of 5 nm to form a hole injection layer. Next, HTL-1 was heated and evaporated to a thickness of 90 nm to form hole transport layer 1, and TcTa was heated and evaporated to a thickness of 10 nm to form hole transport layer 2. Next, TcTa, ETL-1, BCC-TPTA, and comparative compound (1) were simultaneously heated and evaporated to a thickness of 20 nm to form an emitting layer. The evaporation rate was adjusted so that the mass ratio of TcTa, ETL-1, BCC-TPTA, and comparative compound (1) was approximately 44.5:44.5:10:1. Next, ETL-1 was heated and evaporated to a thickness of 20 nm to form electron transport layer 1, and ET7 was heated and evaporated to a thickness of 10 nm to form electron transport layer 2. The evaporation rate for each layer was 0.01 to 1 nm / sec. Thereafter, LiF was heated and evaporated at a deposition rate of 0.01 to 0.1 nm / sec to a thickness of 1 nm, and then aluminum was heated and evaporated at a deposition rate of 100 nm to form a cathode, thereby obtaining an organic EL device of Comparative Example 2-1. At this time, the deposition rate of aluminum was adjusted to 1 to 10 nm / sec.

[0370] The chemical structures in Table 3 and Comparative Example 2-1 are shown below.

[0371] [ka]

[0372] (Examples 2-1 to 2-4 and Comparative Example 2-2) The emitting dopant in Comparative Example 2-1 was changed to each material and concentration shown in Table 3 to fabricate each device.

[0373] (evaluation) The organic EL elements according to Examples 2-1 to 2-4 and Comparative Examples 2-1 and 2-2 exhibited a luminance of 1000 cd / m 2 External quantum efficiency and LT50 (initial luminance 1000 cd / m 2 500 cd / m when continuously driven at a current density of 2The time it took for the liquid to become solid was measured. The results are shown in Table 4.

[0374] [Table 4]

[0375] Comparison with comparative examples shows that the use of the compounds of the present invention results in high efficiency and long life. Furthermore, comparison between examples shows that the use of compound (1-7) results in high efficiency, and the use of compound (1-8) results in long life. [Explanation of symbols]

[0376] 100 Organic electroluminescent device 101 Substrate 102 Anode 103 Hole injection layer 104 Hole transport layer 105 Light-emitting layer 106 Electron transport layer 107 Electron injection layer 108 Cathode

Claims

1. A polycyclic aromatic compound having a structure containing a structural unit represented by the following formula (1A) or (1B): 【Chemistry 1】 In formula (1A) and formula (1B), Each Z is independently N or C—R Ｚ and R Ｚ are each independently hydrogen, any substituent selected from the substituent group Z, or a substituent represented by formula (A30), Two adjacent R Ｚ may be bonded to each other to form, together with ring a, ring b or ring c, an aryl ring optionally substituted with any substituent selected from substituent group Z or a heteroaryl ring optionally substituted with at least one group selected from substituent group Z, X is >O, >N-R ＸＮ , >C(-R ＸＣ ) ２ , >Si(-R ＸＩ ) ２ , >S, or >Se, and R ＸＮ is hydrogen, aryl which may be substituted with at least one group selected from the substituent group Z, heteroaryl which may be substituted with at least one group selected from the substituent group Z, alkyl which may be substituted with at least one group selected from the substituent group Z, or cycloalkyl which may be substituted with at least one group selected from the substituent group Z; R ＸＣ and R ＸＩ are each independently hydrogen, aryl which may be substituted with at least one group selected from the substituent group Z, heteroaryl which may be substituted with at least one group selected from the substituent group Z, alkyl which may be substituted with at least one group selected from the substituent group Z, or cycloalkyl which may be substituted with at least one group selected from the substituent group Z, and two R ＸＣ may be bonded to each other to form a ring, and two R ＸＩ may be bonded to each other to form a ring, and R ＸＮ , R ＸＣ , R ＸＩ may be bonded to at least one of Z adjacent to the carbon atom to which X is bonded by —O—, —S—, —C(-Me) 2 —, —Si(-Me) 2 —, 1,2-phenylene or a single bond, respectively; each of two adjacent Y's is a single bond; Each Y is independently >C(-R Ｙ１ ) ２ and R Ｙ１ are each independently hydrogen, aryl which may be substituted with at least one group selected from the substituent group Z, heteroaryl which may be substituted with at least one group selected from the substituent group Z, alkyl which may be substituted with at least one group selected from the substituent group Z, or cycloalkyl which may be substituted with at least one group selected from the substituent group Z, and two R Ｙ１ may be bonded to each other to form a ring, and in formula (1A), two adjacent R Ｙ１ are bonded to each other to form a ring, and in formula (1B), two adjacent R Ｙ１ may be bonded to each other to form a ring, provided that Y and Z may further be bonded to each other to form a ring consisting of Y-N-C-Z or a ring consisting of Y-C-Z, In the above structure, at least one of the aryl ring or heteroaryl ring may be condensed with at least one cycloalkane, and the cycloalkane may have at least one group selected from the substituent group Z, and at least one -CH ２ - may be replaced by -O-, At least one hydrogen in said structure may be replaced with cyano, halogen, or deuterium; 【Chemistry 2】 In formula (A30), Ak is hydrogen, alkyl which may be substituted with at least one group selected from substituent group Z, alkenyl which may be substituted with at least one group selected from substituent group Z, cycloalkyl which may be substituted with at least one group selected from substituent group Z, or cycloalkenyl which may be substituted with at least one group selected from substituent group Z, wherein at least one —CH 2 — in the alkyl, alkenyl, cycloalkyl, and cycloalkenyl may be replaced by —O— or —S—; R Ak is aryl which may be substituted with at least one group selected from substituent group Z, heteroaryl which may be substituted with at least one group selected from substituent group Z, alkyl which may be substituted with at least one group selected from substituent group Z, or cycloalkyl which may be substituted with at least one group selected from substituent group Z, R Ak may be bonded to Ak by a single bond, >O, >S or >Si(—R) 2 , R in >Si(—R) 2 is hydrogen, aryl having 6 to 12 carbon atoms, alkyl having 1 to 6 carbon atoms or cycloalkyl having 3 to 14 carbon atoms, * indicates the bonding position, The substituent group Z is an aryl optionally substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl, and cycloalkyl; heteroaryl optionally substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl, and cycloalkyl; diarylamino optionally substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl, and cycloalkyl (two aryls may be bonded to each other via linking group 1); diheteroarylamino optionally substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl, and cycloalkyl (two heteroaryls may be bonded to each other via linking group 1); arylheteroarylamino optionally substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl, and cycloalkyl (the aryl and heteroaryl may be bonded to each other via linking group 1); diarylboryl optionally substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl, and cycloalkyl (two aryls may be bonded via a single bond or linking group 2); alkyl optionally substituted with at least one group selected from the group consisting of aryl, heteroaryl and cycloalkyl; cycloalkyl optionally substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl, and cycloalkyl; alkoxy optionally substituted with at least one group selected from the group consisting of aryl, heteroaryl and cycloalkyl; aryloxy optionally substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl, and cycloalkyl; and silyl substituted with at least one of aryl, alkyl, and cycloalkyl; Linking Group 1 is selected from the group consisting of >O, >N-R X , >C(-R X ) 2 , >Si(-R X ) 2 , >S, >CO, >CS, >SO, >SO 2 , >Se, and alkenylene, each R X is independently alkyl, cycloalkyl, aryl, or heteroaryl, which may be substituted with alkyl, cycloalkyl, aryl, or heteroaryl, R X in >C(-R X ) 2 and >Si(-R X ) 2 may be bonded to form a ring via a single bond or a linking group X Y , and X Y is selected from the group consisting of >O, >N-R Y , >C(-R Y ) 2 , >Si(-R Y ) 2 , >S, >CO, >CS, >SO, >SO 2 , and >Se, and R Y are each independently an alkyl, cycloalkyl, aryl or heteroaryl, which may be substituted with an alkyl, cycloalkyl, aryl or heteroaryl, with the proviso that when X Y is >C(-R Y ) 2 or >Si(-R Y ) 2 , two R Y s do not bond to form a ring, any hydrogen atom of the alkenylene may each independently be substituted with R X , and each R X is independently an alkyl, cycloalkyl, substituted silyl (silyl substituted with at least one of aryl, alkyl, and cycloalkyl), aryl or heteroaryl, which may be substituted with an alkyl, cycloalkyl, substituted silyl (silyl substituted with at least one of aryl, alkyl, and cycloalkyl) or aryl; Linking group 2 is selected from the group consisting of -CH=CH-, -CR=CR-, -C≡C-, >N-R, >O, >S, >C(-R) 2 , >Si(-R) 2 , and >Se, and R of -CR=CR-, R of >N-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 atom in the R may be further substituted with an aryl, heteroaryl, alkyl, alkenyl, alkynyl, or cycloalkyl, and two adjacent Rs may form a ring to form a cycloalkylene, arylene, or heteroarylene.

2. A polycyclic aromatic compound having a structure containing a structural unit represented by the following formula (1A) or (1B): 【Transformation 3】 In formula (1A) and formula (1B), Each Z is independently N or C—R Ｚ and R Ｚ are each independently hydrogen or a substituent selected from the substituent group Z, or a substituent represented by formula (A30), Two adjacent R Ｚ may be bonded to each other to form, together with ring a, ring b or ring c, an aryl ring optionally substituted with at least one group selected from substituent group Z or a heteroaryl ring optionally substituted with at least one group selected from substituent group Z, X is >O, >N-R ＸＮ , >C(-R ＸＣ ) ２ , >Si(-R ＸＩ ) ２ , >S, or >Se, and R ＸＮ is hydrogen, aryl which may be substituted with at least one group selected from the substituent group Z, heteroaryl which may be substituted with at least one group selected from the substituent group Z, alkyl which may be substituted with at least one group selected from the substituent group Z, or cycloalkyl which may be substituted with at least one group selected from the substituent group Z; R ＸＣ and R ＸＩ are each independently hydrogen, aryl which may be substituted with at least one group selected from the substituent group Z, heteroaryl which may be substituted with at least one group selected from the substituent group Z, alkyl which may be substituted with at least one group selected from the substituent group Z, or cycloalkyl which may be substituted with at least one group selected from the substituent group Z, and two R ＸＣ may be bonded to each other to form a ring, and two R ＸＩ may be bonded to each other to form a ring, and R ＸＮ , R ＸＣ , R ＸＩ may be bonded to at least one of Z adjacent to the carbon atom to which X is bonded by —O—, —S—, —C(-Me) 2 —, —Si(-Me) 2 —, 1,2-phenylene or a single bond, respectively; each of two adjacent Y's is a double bond; Y is N or C-R Ｙ２ and R Ｙ２ is hydrogen, any substituent selected from the substituent group Z, or a substituent represented by formula (A30), and two adjacent R Ｙ２ may be bonded to each other to form a ring, provided that two adjacent R Ｙ２ do not bond to each other to form a benzene ring, Y and Z may further be bonded to each other to form a ring consisting of Y-N-C-Z or a ring consisting of Y-C-Z, In the above structure, at least one of the aryl ring or heteroaryl ring may be condensed with at least one cycloalkane, and the cycloalkane may have at least one group selected from the substituent group Z, and at least one -CH ２ - may be replaced by -O-, At least one hydrogen in said structure may be replaced with cyano, halogen, or deuterium; 【Chemistry 4】 In formula (A30), Ak is hydrogen, alkyl which may be substituted with at least one group selected from substituent group Z, alkenyl which may be substituted with at least one group selected from substituent group Z, cycloalkyl which may be substituted with at least one group selected from substituent group Z, or cycloalkenyl which may be substituted with at least one group selected from substituent group Z, wherein at least one —CH 2 — in the alkyl, alkenyl, cycloalkyl, and cycloalkenyl may be replaced by —O— or —S—; R Ak is aryl which may be substituted with at least one group selected from substituent group Z, heteroaryl which may be substituted with at least one group selected from substituent group Z, alkyl which may be substituted with at least one group selected from substituent group Z, or cycloalkyl which may be substituted with at least one group selected from substituent group Z, R Ak may be bonded to Ak by a single bond, >O, >S or >Si(—R) 2 , R in >Si(—R) 2 is hydrogen, aryl having 6 to 12 carbon atoms, alkyl having 1 to 6 carbon atoms or cycloalkyl having 3 to 14 carbon atoms, * indicates the bonding position, The substituent group Z is an aryl optionally substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl, and cycloalkyl; heteroaryl optionally substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl, and cycloalkyl; diarylamino optionally substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl, and cycloalkyl (two aryls may be bonded to each other via linking group 1); diheteroarylamino optionally substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl, and cycloalkyl (two heteroaryls may be bonded to each other via linking group 1); arylheteroarylamino optionally substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl, and cycloalkyl (the aryl and heteroaryl may be bonded to each other via linking group 1); diarylboryl optionally substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl, and cycloalkyl (two aryls may be bonded via a single bond or linking group 2); alkyl optionally substituted with at least one group selected from the group consisting of aryl, heteroaryl and cycloalkyl; cycloalkyl optionally substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl, and cycloalkyl; alkoxy optionally substituted with at least one group selected from the group consisting of aryl, heteroaryl and cycloalkyl; aryloxy optionally substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl, and cycloalkyl; and silyl substituted with at least one of aryl, alkyl, and cycloalkyl; Linking Group 1 is selected from the group consisting of >O, >N-R X , >C(-R X ) 2 , >Si(-R X ) 2 , >S, >CO, >CS, >SO, >SO 2 , >Se, and alkenylene, each R X is independently alkyl, cycloalkyl, aryl, or heteroaryl, which may be substituted with alkyl, cycloalkyl, aryl, or heteroaryl, R X in >C(-R X ) 2 and >Si(-R X ) 2 may be bonded to form a ring via a single bond or a linking group X Y , and X Y is selected from the group consisting of >O, >N-R Y , >C(-R Y ) 2 , >Si(-R Y ) 2 , >S, >CO, >CS, >SO, >SO 2 , and >Se, and R Y are each independently an alkyl, cycloalkyl, aryl or heteroaryl, which may be substituted with an alkyl, cycloalkyl, aryl or heteroaryl, with the proviso that when X Y is >C(-R Y ) 2 or >Si(-R Y ) 2 , two R Y s do not bond to form a ring, any hydrogen atom of the alkenylene may each independently be substituted with R X , and each R X is independently an alkyl, cycloalkyl, substituted silyl (silyl substituted with at least one of aryl, alkyl, and cycloalkyl), aryl, or heteroaryl, which may be substituted with an alkyl, cycloalkyl, substituted silyl (silyl substituted with at least one of aryl, alkyl, and cycloalkyl) or aryl; Linking group 2 is selected from the group consisting of -CH=CH-, -CR=CR-, -C≡C-, >N-R, >O, >S, >C(-R) 2 , >Si(-R) 2 , and >Se, and R of -CR=CR-, R of >N-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 atom in the R may be further substituted with an aryl, heteroaryl, alkyl, alkenyl, alkynyl, or cycloalkyl, and two adjacent Rs may form a ring to form a cycloalkylene, arylene, or heteroarylene.

3. Both Z are C-R Ｚ and The polycyclic aromatic compound according to claim 1 or 2, wherein R Z s at the para-position of B (boron) are each independently hydrogen, any substituent selected from the substituent group Z, or a substituent represented by formula (A30), and the other R Z s are hydrogen.

4. The polycyclic aromatic compound according to any one of claims 1 to 3, wherein a substituent on the aryl ring or heteroaryl ring in formula (1A) and formula (1B) is selected from methyl, t-butyl, t-amyl, t-octyl, neopentyl, adamantyl, phenyl, o-tolyl, p-tolyl, 2,4-xylyl, 2,5-xylyl, 2,6-xylyl, 2,4,6-mesityl, diphenylamino, di-p-tolylamino, bis(p-(t-butyl)phenyl)amino, carbazolyl, 3,6-dimethylcarbazolyl, 3,6-di-t-butylcarbazolyl, phenoxy, and a substituent represented by formula (A30).

5. X is > O, > N-R ＸＮ , >C(-R ＸＣ ) ２ , or >S, R ＸＮ is phenyl which may be substituted with at least one group selected from the substituent group Z, and R ＸＣ The polycyclic aromatic compound according to any one of claims 1 to 4, wherein each of

6. The polycyclic aromatic compound according to claim 1, represented by any one of the following formulas: 【Transformation 5】 In the formulas, Me is methyl, the aryl ring may have, as a substituent, alkyl having 1 to 4 carbon atoms or phenyl optionally substituted with alkyl having 1 to 4 carbon atoms, and at least one hydrogen atom in the structure represented by each formula may be replaced with deuterium.

7. The polycyclic aromatic compound according to claim 2, represented by any one of the following formulas: 【Transformation 6】 In the formulas, Me is methyl, the aryl ring may have, as a substituent, alkyl having 1 to 4 carbon atoms or phenyl optionally substituted with alkyl having 1 to 4 carbon atoms, and at least one hydrogen atom in the structure represented by each formula may be replaced with deuterium.

8. A material for an organic device, comprising the polycyclic aromatic compound according to any one of claims 1 to 7.

9. An organic electroluminescence device comprising a pair of electrodes consisting of 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 any one of claims 1 to 7.

10. The organic electroluminescent device according to claim 9 , wherein the organic layer is a light-emitting layer.

11. A display device or a lighting device comprising the organic electroluminescent device according to claim 9 or 10.

Images