Polycyclic aromatic compound

Abstract

To provide a novel compound suitable as a material for organic devices such as organic EL elements.SOLUTION: The present invention provides a polycyclic aromatic compound having a structure composed of one or more structural units represented by formula (1), where A to D rings, P ring, and Q ring are aryl rings or the like, provided that at least one of A to C rings is an aryl ring or the like having a group represented by formula (EABC), and Ar is a group of formula (Ar).SELECTED DRAWING: None

Description

[Technical field]

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

[0002] Conventionally, display devices using electroluminescent light-emitting elements have been extensively studied because they can be made to be energy-saving and thin, and organic electroluminescent elements 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 luminescence properties of blue and green, which are one of the three primary colors of light, and organic materials that have the ability to transport charges such as holes and electrons (potential to become semiconductors or superconductors), regardless of whether they are polymer compounds or low molecular compounds.

[0003] An organic EL element has a structure consisting of a pair of electrodes consisting of an anode and a cathode, and one or more layers containing organic compounds that are 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 Documents 1 to 3 disclose that polycyclic aromatic compounds containing boron are useful as materials for organic electroluminescent devices, etc. It has been reported that organic electroluminescent devices containing these polycyclic aromatic compounds have good external quantum efficiency. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] International Publication No. 2015 / 102118 [Patent Document 2] Korean Patent Publication No. 10-2022-0069866 [Patent Document 3] US Patent Application Publication No. 2021 / 0143331 Summary of the Invention [Problem to be solved by the invention]

[0006] As described above, various materials have been developed for use in organic EL elements. However, in order to increase the options for materials for organic EL elements, it is desirable to develop materials made of compounds 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 elements. [Means for solving the problem]

[0007] The present inventors have conducted extensive research to solve the above problems, and have found that a polycyclic aromatic compound that enables the production of an organic EL device with higher efficiency and longer life can be obtained in a compound having a structure containing boron similar to the compounds described in Patent Documents 1 to 3, thereby completing the present invention. That is, the present invention provides the following polycyclic aromatic compound, and further provides a material for an organic device containing the following polycyclic aromatic compound, etc.

[0008] <1> A polycyclic aromatic compound having a structure consisting of one or more structural units represented by formula (1); [ka]

[0009] In formula (1), ring A, ring B, and ring C each independently represent a substituted or unsubstituted aryl ring or a substituted or unsubstituted heteroaryl ring; However, at least one selected from the group consisting of ring A, ring B, and ring C is represented by the formula (E ABC or an aryl ring having a group represented by the formula (E ABC ) as a substituent, Each Ar is independently a group represented by formula (Ar), Formula (E ABC ) inside, * indicates the point of attachment to the aryl or heteroaryl ring; ring P and ring Q each independently represent a substituted or unsubstituted aryl ring or a substituted or unsubstituted heteroaryl ring; Z X -C(-R ZX )= or -N= and R ZX is hydrogen or a substituent; Y 1 >NR NY ,>C(-R CY )2, >O, >Si(-R IY )2, >PR PY , >P(=O)R POY , >S, >SO, >SO2, or >Se, and R NY , R CY , R IY , R PY , and R POY are each independently hydrogen, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted alkyl, or substituted or unsubstituted cycloalkyl; CY may be bonded to each other to form a ring, and two R IY may be bonded to each other to form a ring, In the formula (Ar), * indicates the bond position to nitrogen Ring D is a substituted or unsubstituted aryl ring or a substituted or unsubstituted heteroaryl ring; R D is a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted arylthio, a substituted or unsubstituted heteroarylthio, a substituted or unsubstituted aryloxy, a substituted or unsubstituted heteroaryloxy, a substituted alkyl, an unsubstituted alkyl having 4 to 24 carbon atoms, or a substituted or unsubstituted cycloalkyl; R Dthe aryl or heteroaryl ring may be bonded to ring D via a single bond or a linking group; At least one selected from the group consisting of aryl rings and heteroaryl rings in the above structure may be fused with at least one cycloalkane, the cycloalkane may be substituted with at least one substituent, and at least one -CH2- in the cycloalkane may be replaced with -O-; In the above structure, at least one hydrogen may be replaced with deuterium and at least one nitrogen may be replaced with nitrogen-15( 15 N), and at least one sulfur may be replaced by sulfur-33 ( 33 S), Sulfur-34( 34 S) or sulfur-36( 36 S), and at least one oxygen may be replaced by oxygen-17 ( 17 O) or oxygen-18( 18 O), and at least one carbon may be replaced by carbon-13 ( 13 C), and at least one boron may be replaced by boron-11 ( 11 B) may be substituted.

[0010] <2> Formula (E ABC ) is the formula (E ABC -1), <1> 4. A polycyclic aromatic compound according to claim 1 ; [ka] Formula (E ABC -1) Medium, Y 1 , Z X is the formula (E ABC ) in Y 1 , Z X are synonymous with Z E are each independently -C(-R ZE )= or -N= and R ZE is hydrogen or a substituent.

[0011] <3> Each Ar is independently a group represented by formula (2Ar), a substituted or unsubstituted 4-dibenzothienyl, a substituted or unsubstituted 1-dibenzothienyl, a substituted or unsubstituted 4-dibenzofuranyl, or a substituted or unsubstituted 1-dibenzofuranyl; <1> or <2> 4. A polycyclic aromatic compound according to claim 1 ; [ka] In the formula (2Ar), R e are each independently hydrogen or unsubstituted alkyl; R d are each independently hydrogen, unsubstituted alkyl, unsubstituted cycloalkyl, or unsubstituted aryl; R dd is hydrogen or substituted or unsubstituted aryl.

[0012] <4> Represented by the formula (1X1), <1> 4. A polycyclic aromatic compound according to claim 1 ; [ka] In formula (1X1), Ar has the same meaning as Ar in formula (1), R a is hydrogen or unsubstituted alkyl; R b is the formula (E ABC -1), a substituted or unsubstituted 9-carbazolyl, or a substituted or unsubstituted diarylamino,

[0013] [ka] Formula (1X1) and Formula (E ABC In each formula of -1), Y 1 , Z X is the formula (E ABC ) in Y 1 , Z X are synonymous with Z E are each independently -C(-RZE )= or -N=, R ZE is hydrogen or a substituent.

[0014] <5> R b is the formula (E ABC -1), <4> The polycyclic aromatic compound according to claim 1.

[0015] <6> Represented by one of the following formulas: <5> 4. A polycyclic aromatic compound according to claim 1 ; [ka] In the formula, tBu is t-butyl.

[0016] <7> R b is a substituted or unsubstituted 9-carbazolyl or a substituted or unsubstituted diarylamino; <4> The polycyclic aromatic compound according to claim 1.

[0017] <8> Represented by one of the following formulas: <7> 4. A polycyclic aromatic compound according to claim 1 ; [ka]

[0018] [ka]

[0019] [ka] In the formula, tBu is t-butyl and Ad is 1-adamantyl.

[0020] <9> The present invention has a pair of electrodes consisting of an anode and a cathode, and an organic layer disposed between the pair of electrodes, <1> ~ <8> 2. An organic electroluminescence device comprising the polycyclic aromatic compound according to claim 1. <10> The organic layer is an emitting layer. <9> The organic electroluminescent device according to claim 1. <11> The light-emitting layer comprises at least one selected from the group consisting of an assisting dopant and a phosphorescent material; <10> The organic electroluminescent device according to claim 1. <12> <9> ~ <11> A display device or a lighting device comprising the organic electroluminescent device according to any one of claims 1 to 4. Effect of the Invention

[0021] The present invention provides a novel polycyclic aromatic compound useful as a material for organic devices such as organic electroluminescence elements. The polycyclic aromatic compound of the present invention can be used in the manufacture of organic devices such as organic electroluminescence elements. [Brief description of the drawings]

[0022] [Figure 1] FIG. 1 is a schematic cross-sectional view showing an example of an organic electroluminescent device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0023] The present invention will be described in detail below. The following description 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 "~" means a range including the numerical values ​​before and after "~" as the lower and upper limits. In this specification, "hydrogen" in the explanation of the structural formula 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.

[0024] In this specification, "Me" is methyl, "Et" is ethyl, "nBu" is n-butyl (normal butyl), "tBu" is t-butyl (tertiary butyl), "iBu" is isobutyl, "secBu" is secondary butyl, "nPr" is n-propyl (normal propyl), "iPr" is isopropyl, "tAm" is t-amyl, "2EH" is 2-ethylhexyl, "tOct" is t-octyl, "Ph" is phenyl, "Mes" is mesityl (2,4,6-trimethylphenyl), "Ad" is 1-adamantyl, "Tf" is trifluoromethanesulfonyl, "TMS" is trimethylsilyl, and "D" is deuterium. In this specification, the organic electroluminescent element may be referred to as an organic EL element.

[0025] In this specification, the chemical structure or the substituent may be expressed by the number of carbon atoms, but the number of carbon atoms in the case where a substituent is substituted on the chemical structure or where a substituent is further substituted on the substituent means the number of carbon atoms in each of the chemical structure and the substituent, and does not mean 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 the substituent A and the substituent 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 (without carbon number limit)", and the carbon number Y is not the total number of carbon atoms in the substituent A and the substituent B.

[0026] <Explanation of rings and substituents> First, the rings and substituents used in the present specification will be described in detail below. In the present specification, the "aryl ring" may, for example, be 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.

[0027] Specific examples of the "aryl ring" include a monocyclic benzene ring, a bicyclic bicyclic bicyclic naphthalene ring, an indene ring, a tricyclic terphenyl ring (m-terphenyl, o-terphenyl, p-terphenyl), a condensed tricyclic acenaphthylene ring, a fluorene ring, a phenalene ring, a phenanthrene ring, an anthracene ring, a condensed tetracyclic triphenylene ring, a pyrene ring, a naphthacene ring, a chrysene ring, a condensed pentacyclic perylene ring, a pentacene ring, etc. In addition, the fluorene ring, the benzofluorene ring, and the 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 those 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, dimethylbenzofluorene ring, dimethylindene ring, etc.

[0028] In the present specification, examples of the "heteroaryl ring" include heteroaryl rings having 2 to 30 carbon atoms, preferably heteroaryl rings having 2 to 25 carbon atoms, more preferably heteroaryl rings having 2 to 20 carbon atoms, further preferably heteroaryl rings having 2 to 15 carbon atoms, and particularly preferably heteroaryl rings having 2 to 10 carbon atoms. In addition, examples of the "heteroaryl ring" include heterocycles containing, as ring-constituting atoms other than carbon, 1 to 5 heteroatoms selected from oxygen, sulfur, nitrogen, boron, selenium, phosphorus, and tellurium.

[0029] Specific examples of the "heteroaryl ring" include a pyrrole ring, an oxazole ring, an isoxazole ring, a thiazole ring, an isothiazole ring, an imidazole ring, an oxadiazole ring (such as a furazan ring), a thiadiazole ring, a triazole ring, a tetrazole ring, a pyrazole ring, a pyridine ring, a pyrimidine ring, a pyridazine ring, a pyrazine ring, a triazine ring, an indole ring, an isoindole ring, a 1H-indazole ring, a benzimidazole ring, a benzoxazole ring, a benzothiazole ring, a 1H-benzotriazole ring, a quinoline ring, an isoquinoline ring, a cinnoline ring, a quinazoline ring, a quinoxaline ring, a phthalazine ring, a naphthyridine ring, a purine ring, a pteridine ring, a carbazole ring, an acridine ring, a 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, and a thiophene ring. , benzothiophene ring, dibenzothiophene ring, thianthrene ring, indolocarbazole ring, benzoindolocarbazole ring, dibenzoindolocarbazole ring, naphthobenzofuran ring, dioxin ring, dihydroacridine ring, xanthene ring, thioxanthene ring, dibenzodioxin ring, dioxaboranaphthoanthracene ring (5,9-dioxa-13b-bora-13bH-naphtho[3,2,1-de]anthracene ring, etc.), benzoselenophene ring, Examples of the ring include a phenylene ring, a dibenzoselenophene ring, an azacarbazole ring, an azadibenzothiophene ring, an azadibenzofuran ring, an azadibenzoselenophene ring, an azatriphenylene ring, an imidazoimidazole ring, an indoloindole ring, a benzofurocarbazole ring, a benzothienocarbazole ring, an indenocarbazole ring, a selenophenocarbazole ring, a spiro[fluorene-9,9'-xanthene] ring, a spirobi[silafluorene] ring, etc. In addition, it is also preferable that the dihydroacridine ring, the xanthene ring, and the thioxanthene ring are such that two of the two hydrogen atoms of the methylene in the structure are replaced by alkyl such as methyl as the first substituent described later, to form 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 the "heteroaryl ring". The "heteroaryl ring" also includes a pyran ring.

[0030] In this specification, a substituent may be substituted with a further substituent. For example, a specific substituent may be described as "substituted or unsubstituted". This means that the specific substituent is substituted with at least one further substituent or is 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 further substituent may be referred to as a "second substituent".

[0031] In this specification, the substituent group Zα consists of the substituents of the substituent group Z and the substituent represented by the formula (A30) described later.

[0032] 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, cycloalkyl, cyano, and halogen; heteroaryl optionally substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl, cycloalkyl, cyano, and halogen; diarylamino which may be substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl, cycloalkyl, cyano, and halogen (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, cycloalkyl, cyano, and halogen (two heteroaryls may be bonded to each other via a linking group); arylheteroarylamino which may be substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl, cycloalkyl, cyano, and halogen (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, cycloalkyl, cyano, and halogen (two aryls may be bonded via a single bond or a linking group); an alkyl group optionally substituted with at least one group selected from the group consisting of aryl, heteroaryl, cycloalkyl, cyano, and halogen; cycloalkyl optionally substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl, cycloalkyl, cyano, and halogen; alkoxy optionally substituted with at least one group selected from the group consisting of aryl, heteroaryl, cycloalkyl, cyano, and halogen; aryloxy optionally substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl, cycloalkyl, cyano, and halogen; Consists of substituted silyl, cyano, and halogen. The second substituent aryl in each group of the substituent group Z may be further substituted with an aryl, heteroaryl, alkyl, cycloalkyl, cyano, or halogen; similarly, the second substituent heteroaryl may be substituted with an aryl, heteroaryl, alkyl, cycloalkyl, cyano, or halogen.

[0033] In the present specification, when referring to a "substituent", the type of the substituent is not particularly limited, but unless otherwise specified, it may be any group selected from the substituent group Z. For example, when a group that is "substituted or unsubstituted" is substituted, the group may be substituted with at least one group selected from the substituent group Z.

[0034] In this specification, "aryl" is, 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.

[0035] Specific examples of "aryl" include monovalent groups obtained by removing one hydrogen from the above-mentioned "aryl ring". For example, the monocyclic ring system phenyl, the bicyclic ring system biphenylyl (2-biphenylyl, 3-biphenylyl, or 4-biphenylyl), the fused bicyclic ring system naphthyl (1-naphthyl or 2-naphthyl), the 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), the 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 system quaterphenylyl (5'-phenyl-m-terphenyl-2-yl, 5'-phenyl-m-terphenyl-3-yl, 5'-phenyl -m-terphenyl-4-yl, or m-quaterphenyl), fused tetracyclic ring systems such as triphenylene-(1- or 2-)yl, pyrene-(1-, 2-, or 4-)yl, or naphthacene-(1-, 2-, or 5-)yl, or fused pentacyclic ring systems such as perylene-(1-, 2-, or 3-)yl, or pentacene-(1-, 2-, 5-, or 6-)yl. Other examples include monovalent groups of spirofluorene.

[0036] 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 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.

[0037] 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 from the above-mentioned "aryl" (monovalent group).

[0038] 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, as a ring-constituting atom other than carbon, one or more heteroatoms selected from oxygen, sulfur, nitrogen, etc., and preferably 1 to 5 heteroatoms.

[0039] Specific examples of the "heteroaryl" include monovalent groups obtained by removing one hydrogen atom from the above-mentioned "heteroaryl ring". For example, 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, acridinyl, phenoxathiinyl, phenoxazinyl, phenothiazinyl, phenazinyl, phenazasilinyl, indolizinyl, furanyl, benzofuranyl, isobenzofuranyl, dibenzofuranyl, naphthobenzofuranyl, thienyl, benzothienyl, isobenzothienyl, dibenzothienyl, naphthobenzothienyl, monovalent groups of benzophosphole oxide rings, monovalent groups of dibenzophosphole oxide rings, furazanyl, thianthrenyl, indolocarbazolyl, benzoindolocarbazolyl, dibenzoindolocarbazolyl, imidazolinyl, oxazolinyl, etc. Other examples include monovalent groups of spiro[fluorene-9,9'-xanthene], monovalent groups of spirobi[silafluorene], and monovalent groups of benzoselenophene.

[0040] 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 group in which the 9-position of the carbazolyl 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. In addition, the heteroaryl as the second substituent also includes groups in which a nitrogen-containing heteroaryl such as pyridyl, pyrimidinyl, triazinyl, or carbazolyl is further substituted with phenyl or biphenylyl.

[0041] 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. In addition, 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 from the above-mentioned "heteroaryl" (monovalent group).

[0042] The term "diarylamino" refers to an amino substituted with two aryls, and the details of the aryls can be found in the above description of the "aryl". The term "diheteroarylamino" refers to an amino group substituted with two heteroaryls. For details of this heteroaryl, the above description of "heteroaryl" can be cited. The "arylheteroarylamino" is an amino group substituted with an aryl and a heteroaryl, and the details of the aryl and the heteroaryl can be found in the above descriptions of the "aryl" and the "heteroaryl".

[0043] 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 with a linking group as shown below. This explanation also applies to diheteroarylamino and arylheteroarylamino formed by aryl and heteroaryl.

[0044] [ka]

[0045] Specific examples of the linking group include >O and >NR X ,>C(-R X )2, -C(-R X )=C(-R X )-, >Si(-R X )2, >S, >CO, >CS, >SO, >SO2, >SeO, >SeO2, >PO, >B(-R X ), and >Se. X are each independently an alkyl, cycloalkyl, aryl, or heteroaryl, which may be substituted with an alkyl, cycloalkyl, aryl, or heteroaryl. X )2, -C(-R X )=C(-R X )-, >Si(-R X )2 The two R X is a single bond or a linking group X Y They may be bonded to each other via X to form a ring. Y As for >O, >NR Y ,>C(-R Y )2, >Si(-R Y )2, >S, >CO, >CS, >SO, >SO2, and >Se, and R Yare 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(-R Y )2, two R Y does not bond to form a ring. Further examples of the linking group include alkenylene. Any hydrogen of the alkenylene can be independently R 2X and R 2X are each independently an alkyl, a cycloalkyl, a substituted silyl, an aryl, or a heteroaryl, which may be substituted with an alkyl, a cycloalkyl, a substituted silyl, or an aryl. X )=C(-R X )- Two R's X may be bonded together to form an aryl ring (such as a benzene ring) or a heteroaryl ring together with the C=C to which they are attached. That is, -C(-R X )=C(-R X )- may be arylene (such as 1,2-phenylene) or heteroarylene.

[0046] In this specification, when "diarylamino", "diheteroarylamino", or "arylheteroarylamino" is simply described, unless otherwise specified, it is assumed that the following explanation is added: "the two aryls of the diarylamino may be bonded to each other via a linking group", "the two heteroaryls of the diheteroarylamino may be bonded to each other via a linking group", and "the aryl and heteroaryl of the arylheteroarylamino may be bonded to each other via a linking group", respectively.

[0047] "Diarylboryl" is a boryl substituted with two aryls, and the details of the aryls can be found in the above description of "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, >C(=O), >C=S, >S=O, >S(=O)2, >Se(=O), >Se(=O)2, >P(=O), >B(-R), or >Se). Here, R of -CR=CR-, R of >NR, R of >C(-R)2, R of >Si(-R), and R of >B(-R) are aryl, heteroaryl, diarylamino, alkyl, alkenyl, alkynyl, cycloalkyl, alkoxy, or aryloxy, and at least one hydrogen in the R may be further substituted with aryl, heteroaryl, alkyl, alkenyl, alkynyl, or cycloalkyl. In addition, two adjacent R may be bonded to each other to 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. In addition, when the term "diarylboryl" is used simply 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 added.

[0048] The "alkyl" may be either straight chain or branched chain, for example, straight chain alkyl having 1 to 24 carbon atoms or branched chain alkyl having 3 to 24 carbon atoms, and preferably alkyl having 1 to 18 carbon atoms (branched chain alkyl having 3 to 18 carbon atoms), alkyl having 1 to 12 carbon atoms (branched chain alkyl having 3 to 12 carbon atoms), alkyl having 1 to 6 carbon atoms (branched chain alkyl having 3 to 6 carbon atoms), alkyl having 1 to 5 carbon atoms (branched chain alkyl having 3 to 5 carbon atoms), alkyl having 1 to 4 carbon atoms (branched chain alkyl having 3 to 4 carbon atoms), etc.

[0049] 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 groups 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.

[0050] An "alkylene" is a divalent group obtained by removing any hydrogen from an "alkyl", such as methylene, ethylene, or propylene.

[0051] For "alkenyl", the explanation of "alkyl" above can be referred to, and 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 alkatriene-yl).

[0052] "Alkenylene" is a divalent group obtained by removing any hydrogen from "alkenyl", and examples include vinylene.

[0053] For "alkynyl", the explanation of "alkyl" above can be referred to, and it is a group in which the 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 alkatriyn-yl).

[0054] The "cycloalkyl" is, for example, cycloalkyl having 3 to 24 carbon atoms, and preferably cycloalkyl having 3 to 20 carbon atoms, cycloalkyl having 3 to 16 carbon atoms, cycloalkyl having 3 to 14 carbon atoms, cycloalkyl having 3 to 12 carbon atoms, cycloalkyl having 5 to 10 carbon atoms, cycloalkyl having 5 to 8 carbon atoms, cycloalkyl having 5 to 6 carbon atoms, or cycloalkyl having 5 carbon atoms.

[0055] Specific examples of "cycloalkyl" include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl, or alkyl (particularly methyl) substituted derivatives of these having 1 to 5 or 1 to 4 carbon atoms, bicyclo[1.1.0]butyl, bicyclo[1.1.1]pentyl, bicyclo[2.1.0]pentyl, bicyclo[2.1.1]hexyl, bicyclo[3.1.0]hexyl, bicyclo[2.2.1]heptyl (norbornyl), bicyclo[2.2.2]octyl, adamantyl, diamantyl, decahydronaphthalenyl, and decahydroazulenyl.

[0056] "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, or the like. A specific example of the "cycloalkylene" is a structure in which one hydrogen is removed from the above-mentioned "cycloalkyl" (monovalent group) to form a divalent group.

[0057] "Cycloalkenyl" refers to a group having a structure in which at least one pair of single bonds between two carbons in the above-mentioned "cycloalkyl" is a double bond (for example, a group in which -CH2-CH2- is replaced with -CH=CH-), and does not fall under the category of aryl. Specific examples include 1-cyclohexenyl and 1-cyclopentenyl.

[0058] "Alkoxy" is a group represented by "Alk-O-(Alk is alkyl)". For details of the alkyl, the above explanation of "alkyl" can be cited.

[0059] "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.

[0060] The "substituted silyl" is, for example, a silyl substituted with at least one of an aryl, an alkyl, and a cycloalkyl, and is preferably a triarylsilyl, a trialkylsilyl, a tricycloalkylsilyl, a dialkylcycloalkylsilyl, or an alkyldicycloalkylsilyl.

[0061] The term "triarylsilyl" refers to a silyl group substituted with three aryl groups. For details of the aryl groups, see the above description of the "aryl". Specific "triarylsilyl" includes, for example, triphenylsilyl, diphenylmononaphthylsilyl, monophenyldinaphthylsilyl, trinaphthylsilyl, and the like.

[0062] The term "trialkylsilyl" refers to a silyl group substituted with three alkyl groups. For details of this alkyl, see the above description of "alkyl." Specific examples of "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.

[0063] The term "tricycloalkylsilyl" refers to a silyl group substituted with three cycloalkyl groups. For details of this cycloalkyl, see the above description of "cycloalkyl." Specific "tricycloalkylsilyl" includes, for example, tricyclopentylsilyl or tricyclohexylsilyl.

[0064] The "dialkylcycloalkylsilyl" is a silyl group substituted with two alkyls and one cycloalkyl. For details of the alkyl and cycloalkyl, see the above descriptions of the "alkyl" and "cycloalkyl".

[0065] The term "alkyldicycloalkylsilyl" refers to a silyl group substituted with one alkyl and two cycloalkyl. For details of the alkyl and cycloalkyl, see the above descriptions of "alkyl" and "cycloalkyl".

[0066] "Halogen" is fluorine, chlorine, bromine or iodine, preferably fluorine, chlorine or bromine, more preferably fluorine or chlorine, even more preferably fluorine.

[0067] When cyano or halogen is substituted, embodiments in which all or a part of the hydrogen atoms in the aryl ring or heteroaryl ring in the structure are replaced with cyano or halogen are also preferred.

[0068] The substituent represented by formula (A30) has the following structure. [ka]

[0069] 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- in the alkyl, cycloalkyl, and cycloalkenyl 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.

[0070] In formula (A30), since Ak is the above-mentioned substituent, it does not conjugate with the unshared electron pair on N, so that the unshared electron pair can be conjugated with the π electron of the bonded destination, and a larger wavelength shift is possible compared to when an aryl or the like is present at the same position. The same applies to the influence on the multiple resonance effect, and a larger improvement in thermally activated delayed fluorescence (TADF) properties is possible.

[0071] 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, even more preferably aryl which may be substituted with alkyl, and particularly preferably phenyl which may be substituted with methyl.

[0072] In formula (A30), Ak is preferably an alkyl group having 1 to 6 carbon atoms or a cycloalkyl group having 3 to 14 carbon atoms, preferably an alkyl group having 1 to 4 carbon atoms or a cycloalkyl group having 3 to 8 carbon atoms, more preferably an alkyl group having 1 to 4 carbon atoms, and even more preferably methyl.

[0073] R Akand Ak may be the same or different, and are preferably different.

[0074] 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.

[0075] [ka] In the above formulas, * indicates a bonding position.

[0076] <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-, -C(=O)-, -C(=S)-, -S(=O)-, -S(=O)2-, -Se(=O)-, -Se(=O)2-, -P(=O)-, -B(-R)-, or -Se-, for example, the following structure. In addition, R of -CHR-CHR-, R of -CR2-CR2-, R of -CR=CR-, R of -N(-R)-, R of -C(-R)2-, R of -Si(-R)2-, and R of -B(-R)- are each independently hydrogen, aryl which may be substituted with alkyl or cycloalkyl, heteroaryl which may be substituted with alkyl or cycloalkyl, alkyl which may be substituted with cycloalkyl, alkenyl which may be substituted with alkyl or cycloalkyl, alkynyl which may be substituted with alkyl or cycloalkyl, or cycloalkyl which may be substituted with alkyl or cycloalkyl. In addition, two adjacent Rs may be bonded to each other to form a ring, forming a cycloalkylene, arylene, or heteroarylene.

[0077] [ka]

[0078] As the bonding group, a single bond and -CR=CR-, -N(-R)-, -O-, -S-, -C(-R)2-, -Si(-R)2-, and -Se- as linking groups 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.

[0079] The position where two R are bonded by the bonding group is not particularly limited as long as it is a bondable position, 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 the ortho (2nd) positions based on the bonding position (1st position) of "C" or "Si" in the phenyl (see the above structural formula).

[0080] <Stereoisomers, etc.> The polycyclic aromatic compound of the present invention may exist as an enantiomer or diastereomer depending on the type of substituents, etc., but regardless of the structural formula described, any stereoisomer in any pure form, any mixture of stereoisomers, racemates, etc. are all intended to be included within the scope of the present invention.

[0081] 1. Polycyclic aromatic compounds <Explanation of the overall structure of the compound> It has already been found that polycyclic aromatic compounds in which aromatic rings are linked by heteroatoms such as boron, nitrogen, oxygen, and sulfur have a large HOMO-LUMO gap (band gap Eg in thin films). This is because six-membered rings containing heteroatoms have low aromaticity, suppressing the decrease in the HOMO-LUMO gap associated with the expansion of the conjugated system. It has also been found that the HOMO-LUMO gap can be arbitrarily changed depending on the type and linking method of the heteroatom. This is thought to be because the HOMO and LUMO energies can be arbitrarily moved depending on the spatial extent and energy of the unoccupied orbitals or lone pairs of the heteroatoms.

[0082] These polycyclic aromatic compounds have narrow half-widths of the fluorescence emission peaks due to the localization of the excited SOMO1 and SOMO2 on each atom caused by electronic perturbation of the heteroatoms, and can emit light with high color purity when used as dopants in organic electroluminescence devices. For the same reason, ΔE(S1T1) is small, and they exhibit thermally activated delayed fluorescence, which can provide high efficiency when used as an emitting dopant in organic electroluminescence devices. Furthermore, by introducing a substituent, the HOMO and LUMO energies can be adjusted as desired, making it possible to optimize the ionization potential and electron affinity depending on the surrounding materials.

[0083] The polycyclic aromatic compound of the present invention corresponds to the above-mentioned polycyclic aromatic compound. The polycyclic aromatic compound of the present invention has a structure consisting of one or more structural units represented by formula (1), and has the formula (E ABC ) and a group represented by formula (Ar) as Ar (hereinafter sometimes referred to as “a polycyclic aromatic compound containing a structural unit represented by formula (1)”).

[0084] [ka]

[0085] In the present invention, the polycyclic aromatic compound having a structural unit represented by formula (1) is represented by the formula (E ABC It has been found that by including a substituent represented by formula (E) as a substituent on an aryl or heteroaryl ring in ring A, ring B, or ring C, and by simultaneously including a group represented by formula (Ar), an organic EL device using this compound can have higher efficiency and longer life. ABC It is believed that the P and Q rings of the structure represented by formula (Ar) protrude into the upper space of the main skeleton plane composed of the A, B, and C rings, covering at least a part of the plane, thereby suppressing the interaction with adjacent molecules. D It is believed that this is also achieved by covering at least a part of the above plane. In particular, in TAF and PSF elements, the emitting dopant is brought to the lowest excited triplet state (T1 state) by Dexter type energy transfer, which is a factor in reducing efficiency and shortening lifetime, but since Dexter type energy transfer does not occur unless the molecules are in contact, it is believed that the T1 state can be avoided by suppressing the interaction between molecules. However, the present invention is not particularly limited to these principles. The symbols in each structure will be explained in detail below.

[0086] <Explanation of ring structure in compound> In formula (1), "A", "B", and "C" in the circles are symbols indicating the ring structures shown by the respective circles. The structure represented by formula (1) has at least three aromatic rings, namely ring A, ring B, and ring C, connected by boron and nitrogen to form a further ring structure. The formed ring structure is a fused ring structure composed of at least five rings.

[0087] Ring A, ring B, and ring C are each independently a substituted or unsubstituted aryl ring or a substituted or unsubstituted heteroaryl ring, provided that at least one selected from the group consisting of ring A, ring B, and ring C is at least one of the rings represented by the formula (E ABC or an aryl ring having a group represented by the formula (E ABC ) as a substituent.

[0088] The ring A forms a trivalent group having bonds to three consecutive atoms (preferably carbon) on the ring of the aryl ring or heteroaryl ring in the structure. The three bonds of the ring A bond two N (nitrogen) and B (boron). In the ring A, the ring having the atom having the above bond as a ring-constituting atom is preferably a five-membered ring or a six-membered ring, more preferably a six-membered ring. This ring may be further condensed with another ring. Examples of the six-membered ring include a benzene ring, a pyridine ring, a pyrazine ring, and a pyrimidine ring. Examples of the six-membered ring further condensed with another ring include a naphthalene ring, a quinoline ring, a dibenzofuran ring, a dibenzothiophene ring, and a carbazole ring. Examples of the five-membered ring include a furan ring, a thiophene ring, a pyrrole ring, and a thiazole ring. Examples of the five-membered ring further condensed with another ring include a benzofuran ring, a benzothiophene ring, and an indole ring. In addition, an indene ring can be mentioned as a condensed ring. The aryl ring or heteroaryl ring in ring A is preferably a benzene ring.

[0089] Both ring B and ring C form a divalent group having bonds to two atoms (preferably carbon) adjacent to each other on the ring of the aryl ring or heteroaryl ring in the structure. Ring B is bonded to N (nitrogen) and B (boron) with the above-mentioned two bonds, and ring C is bonded to N (nitrogen) and B (boron) with the above-mentioned two bonds. In each of ring B and ring C, the ring having the atoms having the above-mentioned two bonds as ring-constituting atoms is preferably a 5-membered ring or a 6-membered ring, more preferably a 6-membered ring. This ring may be further condensed with another ring. Examples of the 6-membered ring include a benzene ring, a pyridine ring, a pyrazine ring, and a pyrimidine ring. Examples of the 6-membered ring further condensed with another ring include a naphthalene ring, a quinoline ring, a benzofuran ring, a benzothiophene ring, an indole ring, a benzoselenophene ring, a dibenzofuran ring, a dibenzothiophene ring, a carbazole ring, and a dibenzoselenophene ring. Examples of five-membered rings include a furan ring, a thiophene ring, a pyrrole ring, a thiazole ring, and a selenophene ring. Examples of five-membered rings fused with other rings include a benzofuran ring, a benzothiophene ring, an indole ring, and a benzoselenophene ring. An example of a fused ring is an indene ring. The aryl ring or heteroaryl ring in ring B and ring C is preferably a benzene ring, a benzofuran ring, a benzothiophene ring, an indene ring, or a benzoselenophene ring, more preferably a benzene ring, a benzofuran ring, an indene ring, or a benzothiophene ring, and further preferably a benzene ring.

[0090] As described later, in the polycyclic aromatic compound of the present invention having a structure consisting of two or more structural units bonded so as to share a ring, the A ring, the B ring or the C ring may have four or five bonds.

[0091] In the substituted or unsubstituted aryl ring or substituted or unsubstituted heteroaryl ring in ring A, ring B, and ring C, the substituent (formula (EABC The substituents other than the group represented by Zα) include at least one substituent selected from the substituent group Zα. The substituent may be a substituted or unsubstituted diarylphosphino such as diphenylphosphino. When a plurality of substituents are present, the plurality of substituents may be the same or different from each other. The substituent is preferably a substituted or unsubstituted alkyl, a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, or a substituted or unsubstituted diarylamino, and more preferably t-butyl, a substituted or unsubstituted diphenylamino, or a substituted or unsubstituted carbazolyl. For other preferred substituents, the description in <Preferred Substituents> described below can be referred to.

[0092] <expression(E ABC ) Explanation> The polycyclic aromatic compound of the present invention has at least one group represented by the formula (E ABC ) as a substituent of an aryl or heteroaryl ring in the A, B or C ring. [ka]

[0093] Formula (E ABC In these formulas, * indicates the position of attachment to the aryl or heteroaryl ring. Formula (E ABC ) "Q" and "P" in the circles are symbols indicating the ring structures shown in each circle. Formula (E ABC In the above, the Q ring and the P ring each form a divalent group having bonds to two adjacent elements (preferably carbon) on the aryl ring or heteroaryl ring in the structure, and the two bonds are connected to nitrogen or Y. 1 and Z X is bonded to the carbon adjacent to

[0094] In the case of the substituted or unsubstituted aryl ring or the substituted or unsubstituted heteroaryl ring in the Q ring and the P ring, the substituent when "substituted or unsubstituted (substituted or unsubstituted)" is used includes at least one substituent selected from the substituent group Zα. The ring having the above-mentioned element having two bonds as a ring constituent element is preferably a 5-membered ring or a 6-membered ring, more preferably a 6-membered ring. This ring may be further condensed with another ring. Examples of the 6-membered ring include a benzene ring, a pyridine ring, a pyrazine ring, and a pyrimidine ring. Examples of the 6-membered ring further condensed with another ring include a naphthalene ring, a quinoline ring, a benzofuran ring, a benzothiophene ring, an indole ring, a benzoselenophene ring, a dibenzofuran ring, a dibenzothiophene ring, a carbazole ring, and a dibenzoselenophene ring. Examples of the 5-membered ring include a furan ring, a thiophene ring, a pyrrole ring, a thiazole ring, and a selenophene ring. Examples of a five-membered ring condensed with another ring include a benzofuran ring, a benzothiophene ring, an indole ring, and a benzoselenophene ring.

[0095] Q ring and P ring are each independently preferably a substituted or unsubstituted benzene ring, a substituted or unsubstituted dibenzofuran ring, a substituted or unsubstituted dibenzothiophene ring, a substituted or unsubstituted dibenzoselenophene ring, or a substituted or unsubstituted N-phenylcarbazole ring, more preferably an unsubstituted benzene ring, an unsubstituted dibenzofuran ring, an unsubstituted dibenzothiophene ring, an unsubstituted dibenzoselenophene ring, or an unsubstituted N-phenylcarbazole ring, and even more preferably an unsubstituted benzene ring. At least one of Q ring and P ring is preferably a substituted or unsubstituted benzene ring, and more preferably an unsubstituted benzene ring. Both Q ring and P ring are preferably unsubstituted benzene rings.

[0096] Formula (E ABC ) in Z X -C(-R ZX )= or -N=, both of which are -C(-R ZX)= is preferred. R ZX are each independently hydrogen or a substituent. ZX When R is a substituent, the substituent may be at least one substituent selected from the substituent group Zα, and is preferably a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted alkyl, or a substituted or unsubstituted cycloalkyl, and more preferably an unsubstituted alkyl. ZX are preferably all hydrogen.

[0097] Y 1 >NR NY ,>C(-R CY )2, >O, >Si(-R IY )2, >PR PY , >P(=O)R POY , >S, >SO, >SO2, or >Se, and R NY , R CY , R IY , R PY , and R POY are each independently hydrogen, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted alkyl, or substituted or unsubstituted cycloalkyl; CY may be bonded to each other to form a ring, and two R IY may be bonded to each other to form a ring. NY R is preferably a substituted or unsubstituted aryl having 6 to 18 carbon atoms, and more preferably an unsubstituted phenyl. CY and R IY are each independently preferably an aryl having 6 to 18 carbon atoms or an alkyl having 1 to 18 carbon atoms, and more preferably unsubstituted phenyl or methyl.

[0098] Y 1 From the viewpoint of deep HOMO, >NR NY , >O, or >S is preferred, >O or >S is more preferred, and >S is even more preferred. From the viewpoint of preventing interaction with adjacent molecules, >NR NY,>C(-R CY )2, >O, >Si(-R IY )2, or >S is preferred, >NR NY ,>C(-R CY )2, or >Si(-R IY )2 is more preferable. From the viewpoint of fast TADF, >Si(-R IY )2, >PR PY , >P(=O)R POY , >S, >SO, >SO2, or >Se is preferred, and >Si(-R IY )2, >S, or >Se are more preferred.

[0099] Formula (E ABC Preferred examples of the group represented by the formula (E ABC Examples of the groups include those represented by the formula (1). [ka]

[0100] Formula (E ABC -1) Middle, Y 1 is the formula (E ABC ) in Y 1 The meaning and preferred range are also the same. X is the formula (E ABC ) in Z X The meaning and preferred range are also the same. E are each independently -C(-R ZE )= or -N= and R ZE is hydrogen or a substituent.

[0101] -N = Z E is the formula (E ABC In each monocyclic ring in formula (E-1), it is preferable that the number is 0 to 2, more preferably 0 to 1, and further preferably 0. ABC -1), Z E are both -C(-R ZE )= is preferred.

[0102] R ZEWhen R is a substituent, the substituent may be at least one substituent selected from the substituent group Zα, and is preferably a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted alkyl, or a substituted or unsubstituted cycloalkyl, and more preferably an unsubstituted alkyl. ZE Each of the substituents R is preferably hydrogen. ZE From the viewpoint of improving stability in the element, the position of 1 It is preferably in the o- or p-position relative to the above, and more preferably in the p-position.

[0103] Formula (E ABC Specific examples of the group represented by the formula (I) are shown below. In each formula, * indicates the bonding position to the aryl ring or heteroaryl ring. [ka]

[0104] [ka]

[0105] [ka]

[0106] [ka]

[0107] The formula (E ABC The number of groups represented by the formula (E) is preferably 1 to 3, and more preferably 1 to 2. ABC When a plurality of groups represented by the formula (E ABC From the viewpoint of easiness of synthesis, the groups represented by the formula (E ABC ) are preferably the same as each other.

[0108] The substitution position of the group represented by formula (E ABC ) is not particularly limited. However, when the aryl ring to which the group represented by formula (E ABC ) is attached is a benzene ring, the group represented by formula (E ABC ) is preferably substituted at the para-position of boron (B).

[0109] Also, the group represented by formula (E ABC ) may be contained in any of ring A, ring B, and ring C, but is preferably contained in at least one of ring B and ring C. When at least one, particularly both, of ring B and ring C are benzene rings in which the group represented by formula (E ABC ) is substituted at the para-position of boron (B), the interaction with neighboring molecules can be further suppressed.

[0110] <Description of Ar In formula (1), Ar is independently a group represented by the following formula (Ar).

Chemical formula

[0111] In formula (Ar), ring D is a substituted or unsubstituted aryl ring or a substituted or unsubstituted heteroaryl ring, and R D is a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted arylthio, a substituted or unsubstituted heteroarylthio, a substituted or unsubstituted arylthio, a substituted or unsubstituted heteroarylthio, a substituted or unsubstituted aryloxy, a substituted or unsubstituted heteroaryloxy, a substituted alkyl, an unsubstituted alkyl having 4 to 24 carbon atoms (such as t-butyl, t-amyl, etc.), or a substituted or unsubstituted cycloalkyl. The aryl ring or heteroaryl ring in R D may be attached to ring D via a single bond or a linking group. * indicates the bonding position to N (nitrogen).

[0112] The polycyclic aromatic compound of the present invention has a group represented by formula (Ar), and as described above, the organic EL device using the compound can have a higher efficiency and a longer life. In addition, the polycyclic aromatic compound of the present invention having a group represented by formula (Ar) has a lower sublimation temperature compared to a similar compound not having this group. The lowering of the sublimation temperature means that purification can be performed at a relatively low temperature in sublimation purification, which is almost essential as a purification method for materials for organic devices such as organic EL elements that require high purity, and therefore thermal decomposition of the material can be avoided. This also applies to the vacuum deposition process, which is a powerful means for producing organic devices such as organic EL elements, and means that the process can be performed at a relatively low temperature, thereby preventing thermal decomposition of the material and resulting in a high-performance organic device. Without being bound by any particular theory, the lowering of the sublimation temperature is believed to be due to the fact that R D This is believed to be because the presence of a group represented by formula (Ar) having a bulky group at the end makes the entire molecule bulkier.

[0113] In addition, by having a group represented by formula (Ar), the polycyclic aromatic compound of the present invention emits light at a shorter wavelength, has higher luminous efficiency, and has a longer device life, compared to a compound not having a group represented by formula (Ar). Without being bound by any particular theory, this is thought to be because the group represented by formula (Ar) sterically protects the skeleton involved in light emission, as described above, thereby reducing interactions with surrounding molecules and making decomposition reactions less likely to occur.

[0114] In formula (Ar), "D" in a circle is a symbol indicating the ring structure indicated by the circle, and the ring D is a substituted or unsubstituted aryl ring or a substituted or unsubstituted heteroaryl ring. The ring D forms a divalent group having bonds to two adjacent elements (preferably carbon) on the ring of the aryl ring or heteroaryl ring in the structure, and the two bonds connect N (nitrogen) and R D It is bonded to R DWhen the aryl or heteroaryl ring in is bonded to ring D via a single bond or a linking group, ring D forms a trivalent group having bonds to three elements (preferably carbon) on the aryl or heteroaryl ring in the structure. It is preferred that the three elements are adjacent to each other.

[0115] In the substituted or unsubstituted aryl ring or substituted or unsubstituted heteroaryl ring in ring D, the substituent when "substituted or unsubstituted (substituted or unsubstituted)" is used includes at least one substituent selected from the substituent group Zα, and unsubstituted alkyl is preferable.

[0116] Ring D is preferably a substituted or unsubstituted benzene ring, a substituted or unsubstituted benzothiophene ring, a substituted or unsubstituted benzofuran ring, or a substituted or unsubstituted indole ring, more preferably a substituted or unsubstituted benzene ring, and even more preferably an unsubstituted benzene ring or a benzene ring having a substituent at the ortho-position of the nitrogen.

[0117] In formula (Ar), R D In the case where the aryl ring or heteroaryl ring in is bonded to ring D via a single bond or a linking group, examples of the linking group include -CH2-CH2-, -CHR-CHR-, -CR2-CR2-, -CH=CH-, -CR=CR-, -C≡C-, -N(-R)-, -O-, -S-, -C(-R)2-, -C(=O)-, -Si(-R)2-, and -Se-. L =CR L -, -N(-R L )-, -O-, -S-, and -C(-R L )2- is preferred, and -CH=CH-, -CR L =CR L -, -N(-R L )-, -O-, and -S- are more preferred, and -CR L =CR L -, -N(-R L )-, -O-, and -S- are more preferred. Lare each independently hydrogen, aryl optionally substituted with alkyl or cycloalkyl, heteroaryl optionally substituted with alkyl or cycloalkyl, alkyl optionally substituted with alkyl or cycloalkyl, alkenyl optionally substituted with alkyl or cycloalkyl, alkynyl optionally substituted with alkyl or cycloalkyl, or cycloalkyl optionally substituted with alkyl or cycloalkyl. In addition, two R L may be bonded to each other to form a ring. L They may also be linked together to form cycloalkylene, arylene, and heteroarylene rings, which may also be substituted with alkyl or cycloalkyl.

[0118] R D A group represented by formula (Ar) in which the aryl ring or heteroaryl ring is bonded to ring D via a single bond or a linking group can be represented, for example, by formula (Ar-L). [ka]

[0119] In formula (Ar-L), "E" in a circle is a symbol indicating the ring structure indicated by the circle, and ring E is a substituted or unsubstituted aryl ring or a substituted or unsubstituted heteroaryl ring. Ring E forms a divalent group having bonds to two adjacent elements (preferably carbon) on the ring of the aryl ring or heteroaryl ring in the structure, and the two bonds form X D and is bound to L.

[0120] In the substituted or unsubstituted aryl ring or substituted or unsubstituted heteroaryl ring in ring E, the substituent when "substituted or unsubstituted (substituted or unsubstituted)" is mentioned includes at least one substituent selected from the substituent group Zα, and unsubstituted alkyl is preferable.

[0121] The E ring is preferably a substituted or unsubstituted benzene ring, a substituted or unsubstituted benzothiophene ring, a substituted or unsubstituted benzofuran ring, or a substituted or unsubstituted indole ring, more preferably a substituted or unsubstituted benzene ring, and even more preferably an unsubstituted benzene ring.

[0122] In formula (Ar-L), X D is a single bond, -O-, -S-, or -C(-R CX )2- and R CX is an alkyl group having 1 to 12 carbon atoms or an aryl group having 6 to 12 carbon atoms. D is preferably a single bond, -O-, or -S-. In formula (Ar-L), L is a single bond, -CH2-CH2-, -CHR-CHR-, -CR2-CR2-, -CH=CH-, -CR=CR-, -C≡C-, -N(-R)-, -O-, -S-, -C(-R)2-, -C(=O)-, -Si(-R)2-, or -Se-. D is a single bond, L is not a single bond. L is -CH=CH-, -CR L =CR L -, -N(-R L )-, -O-, -S-, and -C(-R L )2- is preferred, and -CH=CH-, -CR L =CR L -, -N(-R L )-, -O-, and -S- are more preferred, and -CR L =CR L -, -N(-R L )-, -O-, and -S- are more preferred.

[0123] Preferred examples of the group represented by formula (Ar-L) further include substituted or unsubstituted 4-dibenzothienyl, substituted or unsubstituted 1-dibenzothienyl, substituted or unsubstituted 4-dibenzofuranyl, and substituted or unsubstituted 1-dibenzofuranyl.

[0124] In formula (Ar), R DFrom the viewpoints of sublimation temperature and luminous efficiency, R is preferably a phenyl having an alkyl group as a substituent. D From the viewpoint of device life, R is preferably an unsubstituted phenyl. D is preferably unsubstituted phenyl. D As mentioned above, R D It is also preferred that the aryl or heteroaryl ring in is bonded to ring D via a single bond or a linking group.

[0125] A preferred example of the group represented by formula (Ar) is a group represented by formula (Ar-a). [ka]

[0126] In formula (Ar-a), each Z is independently -CR Z = or -N = and R Z are each independently hydrogen or a substituent; R Z Adjacent groups among these may be bonded to each other to form an aryl ring or a heteroaryl ring together with the ring d or ring e, respectively, and the formed ring may be substituted with at least one substituent selected from the substituent group Zα. Z Examples of the ring formed by bonding adjacent groups to ring d or ring e include a naphthalene ring, a carbazole ring, an indole ring, a dibenzofuran ring, and a dibenzothiophene ring.

[0127] Z is -CR Z = R Z are each preferably independently hydrogen or any substituent selected from the substituent group Zα, and more preferably hydrogen, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted alkyl, or substituted or unsubstituted cycloalkyl.

[0128] A preferred example of the group represented by formula (Ar-a) is a group represented by formula (2Ar). [ka]

[0129] In formula (2Ar), R e are each independently hydrogen or a substituent, preferably hydrogen, unsubstituted alkyl, or unsubstituted cycloalkyl, more preferably hydrogen or unsubstituted alkyl. e Among them, R is a substituent e From the viewpoint of low sublimation temperature, the number of substituents R is preferably 0 to 2, and more preferably 0 to 1. e The position of R in the structure represented by formula (Ar) is m-position or p-position with respect to the bonding position with the d ring. D (e ring and R e It is preferable from the viewpoint of making the part consisting of R e must all be hydrogen or contain one or two R e is unsubstituted alkyl or unsubstituted cycloalkyl, and other R e is preferably hydrogen. e It is also preferred that adjacent R are bonded to each other to form a cycloalkene structure together with the carbon atom to which they are bonded. This structure corresponds to the structure in which an aryl ring is condensed with a cycloalkane, which will be described later. In particular, e are preferably bonded to each other to form a structure represented by formula (B11) or formula (B12). e R at m position relative to the bond position with the d ring e and p-position R e It is preferable that:

[0130] In formula (2Ar), R dare each independently hydrogen or a substituent, preferably hydrogen, unsubstituted alkyl, unsubstituted cycloalkyl, or substituted or unsubstituted aryl, more preferably hydrogen or unsubstituted alkyl. d Among them, R is a substituent d From the viewpoint of low sublimation temperature, the number of substituents R is preferably 0 to 2, and more preferably 0 to 1. d The position of is preferably p-position with respect to * from the viewpoint of high orientation.

[0131] In formula (2Ar), R dd is hydrogen or a substituent, preferably hydrogen, unsubstituted alkyl, unsubstituted cycloalkyl, substituted or unsubstituted aryl, or substituted or unsubstituted heteroaryl, more preferably hydrogen, unsubstituted alkyl, or substituted or unsubstituted aryl, and even more preferably hydrogen or unsubstituted phenyl. From the viewpoint that the main skeleton plane of the polycyclic aromatic compound can be covered from both the upper and lower sides by the group represented by formula (Ar-a), R dd is preferably unsubstituted alkyl or substituted or unsubstituted aryl, more preferably substituted or unsubstituted aryl, further preferably substituted or unsubstituted phenyl, and even more preferably unsubstituted phenyl. From the viewpoint of low sublimation temperature, hydrogen or unsubstituted alkyl is preferred, and hydrogen is more preferred.

[0132] Specific examples of the group represented by formula (Ar) are shown below. In each formula, * indicates the bonding position. [ka]

[0133] [ka]

[0134] [ka]

[0135] In the polycyclic aromatic compound containing the structural unit represented by formula (1), the groups represented by formula (Ar) may be the same or different from each other. From the viewpoint of ease of synthesis, it is preferable that the groups represented by formula (Ar) are the same as each other.

[0136] <Structure consisting of one or more structural units> The polycyclic aromatic compound of the present invention is a polycyclic aromatic compound having a structure consisting of one or more structural units represented by formula (1). The polycyclic aromatic compound having a structure consisting of one of the above structural units is a polycyclic aromatic compound represented by the formula explained above as the structural unit represented by formula (1).

[0137] A polycyclic aromatic compound having a structure consisting of two or more structural units represented by formula (1) is a compound corresponding to a multimer of a polycyclic aromatic compound represented by the formula described above as a structural unit represented by formula (1). The multimer is preferably a dimer to hexamer, more preferably a dimer to trimer. The multimer may have a form in which a plurality of the structural units have the above structural units in one compound, and may be a form in which any ring (ring A, ring B, or ring C) contained in the above structural units is bonded to each other so as to be shared, or any ring (ring A, ring B, or ring C) contained in the above structural units is bonded to each other so as to be condensed. In addition, any ring (ring A, ring B, or ring C) contained in the above structural unit and X bonded thereto may be bonded to each other so as to be shared by multiple structural units. The above structural units may be bonded to each other by a linking group such as a single bond, an alkylene having 1 to 3 carbon atoms, phenylene, or naphthylene. Among these, a form in which the rings are bonded to each other so as to be shared is preferred. In a polycyclic aromatic compound having a structure consisting of two or more structural units represented by formula (1), the two or more structural units may be the same or different from each other. Formula (E ABCAlthough an aryl ring or heteroaryl ring having a group represented by the formula (I) as a substituent may be contained in each structural unit, it is sufficient that the polycyclic aromatic compound as a whole contains at least one ring.

[0138] <Formula (1X1)> A preferred example of a polycyclic aromatic compound having a structure consisting of one or more structural units represented by formula (1) is a polycyclic aromatic compound represented by formula (1X1).

[0139] [ka]

[0140] In formula (1X1), Ar has the same meaning as Ar in formula (1), and the preferred range is also the same. 1 , Z E is the formula (E ABC -1) Y in 1 , Z E The meanings and preferred ranges of R are the same as those of R. a is hydrogen or unsubstituted alkyl, preferably hydrogen, methyl or t-butyl. b is the formula (E ABC -1), substituted or unsubstituted 9-carbazolyl, or substituted or unsubstituted diarylamino. As the substituted or unsubstituted 9-carbazolyl, 9-carbazolyl having one or two substituents selected from the group consisting of aryl (such as phenyl) and heteroaryl (such as 9-carbazolyl) or unsubstituted 9-carbazolyl is preferred. As the substituted or unsubstituted diarylamino, diphenylamino, biphenylylphenylamino, etc. are preferred.

[0141] <Preferred Substituents> In polycyclic aromatic compounds used as emitting dopants (and in other compounds used as dopants), the tertiary alkyl represented by the following formula (tR) is one of the particularly preferred substituents containing "alkyl". This is because such bulky substituents increase the intermolecular distance, thereby improving the luminescence quantum yield (PLQY). In addition, a substituent in which the tertiary alkyl represented by formula (tR) is substituted with another substituent as a second substituent is also preferred. Specifically, diarylamino substituted with a tertiary alkyl represented by formula (tR), carbazolyl (preferably N-carbazolyl) substituted with a tertiary alkyl represented by formula (tR), or benzocarbazolyl (preferably N-benzocarbazolyl) substituted with a tertiary alkyl represented by formula (tR) are mentioned. 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 replaced with a group represented by formula (tR).

[0142] [ka]

[0143] In the formula (tR), R a , R b , and R c each independently represents an alkyl group having 1 to 24 carbon atoms, any -CH2- in the alkyl group may be replaced with -O-, and the group represented by formula (tR) has * as the bonding position.

[0144] R a , R b and R cThe "alkyl having 1 to 24 carbon atoms" may be either linear or branched, and examples thereof include linear alkyl having 1 to 24 carbon atoms or branched alkyl having 3 to 24 carbon atoms, alkyl having 1 to 18 carbon atoms (branched alkyl having 3 to 18 carbon atoms), alkyl having 1 to 12 carbon atoms (branched alkyl having 3 to 12 carbon atoms), alkyl having 1 to 6 carbon atoms (branched alkyl having 3 to 6 carbon atoms), and alkyl having 1 to 4 carbon atoms (branched alkyl having 3 to 4 carbon atoms).

[0145] 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.

[0146] 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 Examples of the aryl group include n-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.

[0147] Examples of the group represented by the 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.

[0148] The substituent is also preferably a substituent represented by formula (A30).

[0149] The emission wavelength can be adjusted by the steric hindrance, electron donating property and electron withdrawing property of the structure of the substituent of the compound used as a dopant (assisting dopant or emitting dopant). Preferred are groups represented by the following structural formulas, and more preferred are 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-butyl, Preferred are 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, 3,6-di-t-butylcarbazolyl, and tribenzoazepinyl. From the viewpoint of ease of synthesis, 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.

[0150] In the following structural formulas, * indicates a bond position. [ka]

[0151] [ka]

[0152] [ka]

[0153]

change

[0154]

change

[0155]

change

[0156]

change

[0157]

change

[0158]

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[0159]

change

[0160]

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[0161]

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[0162]

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[0163]

change

[0164] The polycyclic aromatic compound containing the structural unit represented by formula (1) is preferably a structure containing at least one tertiary alkyl (such as t-butyl or t-amyl), neopentyl or adamantyl 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 a bulky substituent increases 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. Examples of the substitution form of the group represented by formula (tR) on diarylamino, carbazolyl and benzocarbazolyl include 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 represented by formula (tR).

[0165] In particular, in the case of the substituted or unsubstituted aryl ring or the substituted or unsubstituted heteroaryl ring in the A ring, B ring, and C ring of the polycyclic aromatic compound containing the structural unit represented by formula (1), the substituent when "substituted or unsubstituted (substituted or unsubstituted)" is used is preferably substituted or unsubstituted N-carbazolyl. It has been found that when a compound having N-carbazolyl as a substituent is used as a dopant in the light-emitting layer, an organic EL device with a longer life and lower driving voltage can be obtained. It is believed that by having N-carbazolyl as a substituent, the HOMO of the compound becomes deeper, the hole trapping property decreases, and the driving voltage decreases. It is also believed that carrier recombination is less likely to occur on the dopant, the dopant is less likely to enter the T1 state, and the life is longer. Here, when N-carbazolyl has a substituent, the substituent is preferably selected from the group consisting of substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted alkyl, and substituted or unsubstituted cycloalkyl. As the substituted or unsubstituted N-carbazolyl, particularly unsubstituted N-carbazolyl or 3,6-di(t-butyl)N-carbazolyl is preferable.

[0166] In the structure containing the structural unit represented by formula (1), the substituent on the aryl ring or heteroaryl ring may be a substituent represented by the following formula (A20). [ka]

[0167] The substituent represented by formula (A20) is bonded to two adjacent atoms on the ring of the aryl ring or heteroaryl ring at two *'s, respectively. In formula (A20), L is >NR, >O, >Si(-R)2 or >S, R of the >NR is substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted alkyl or substituted or unsubstituted cycloalkyl, R of the >Si(-R)2 is hydrogen, optionally substituted aryl, optionally substituted alkyl or optionally substituted cycloalkyl, and may be bonded to each other by a linking group, and at least one of the R of the >NR and the >Si(-R)2 may be bonded to the aryl ring or heteroaryl ring by 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; A is any other R A and may be bonded to each other via a linking group or a single bond.

[0168] Examples of the above-mentioned substituent include any of the following substituents. [ka]

[0169] In each formula, * may be bonded to two or three consecutive (adjacent) atoms on the ring of any aryl or heteroaryl ring.

[0170] <Cycloalkane condensation> At least one selected from the group consisting of aryl rings and heteroaryl rings in the polycyclic aromatic compound containing the structural unit represented by formula (1) may be condensed with at least one cycloalkane. The same applies to the polycyclic aromatic compound represented by formula (1X1), and the following explanation also applies to the polycyclic aromatic compound represented by any of these formulas.

[0171] The cycloalkane may be a cycloalkane having 3 to 24 carbon atoms. In this case, at least one hydrogen 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- in the cycloalkane may be replaced with -O-.

[0172] 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.

[0173] 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.

[0174] Specific examples of cycloalkanes include cyclopropane, cyclobutane, cyclopentane, cyclohexane, cycloheptane, cyclooctane, cyclononane, cyclodecane, norbornane (bicyclo[2.2.1]heptane), bicyclo[1.1.0]butane, bicyclo[1.1.1]pentane, bicyclo[2.1.0]pentane, bicyclo[2.1.1]hexane, bicyclo[3.1.0]hexane, bicyclo[2.2.2]octane, adamantane, diamantane, decahydronaphthalene, and decahydroazulene, as well as alkyl (particularly methyl) substituted, halogen (particularly fluorine) substituted, and deuterium substituted derivatives of these having 1 to 5 carbon atoms.

[0175] Among the above examples, a structure having at least one substituent on the carbon at the α-position of the cycloalkane (the carbon at the position adjacent to the carbon at the condensation site in the cycloalkane condensed to an aryl ring or heteroaryl ring), as shown in the following structural formula, is preferred, a structure having two substituents on the carbon at the α-position is more preferred, and a structure having two substituents on each of the two α-position carbons (four substituents in total) is even more preferred. Examples of the substituent include an alkyl group having 1 to 5 carbon atoms (particularly methyl), halogen (particularly fluorine), and deuterium. In particular, a structure in which a partial structure represented by the following formula (B11) or (B12) is bonded to adjacent carbon atoms in an aryl ring or heteroaryl ring is preferred, and a structure in which a partial structure represented by the following formula (B11) is bonded is more preferred.

[0176] [ka] In each of formulae (B11) and (B12), * indicates a bonding position.

[0177] 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, the following shows an example in which one or more cycloalkanes are fused to one benzene ring (phenyl). * indicates a bonding position, and the position may be any carbon that constitutes a benzene ring and does not constitute a cycloalkane. Cycloalkanes fused to each other as in formula (Cy-1-4) and formula (Cy-2-4) may be fused together. The same applies even if the ring (group) to be fused is an aryl ring or heteroaryl ring other than a benzene ring (phenyl) or if the condensed cycloalkane is a cycloalkane other than cyclopentane or cyclohexane.

[0178] [ka]

[0179] At least one -CH2- in the cycloalkane may be replaced with -O-. For example, the following shows an example in which one or more -CH2- in a cycloalkane fused to one benzene ring (phenyl) are replaced with -O-. The same applies even 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.

[0180] [ka]

[0181] The cycloalkane may be substituted with at least one substituent, and the substituent may be any of the substituents selected from the substituent group Z. Among these substituents, alkyl (e.g., alkyl having 1 to 6 carbon atoms) and cycloalkyl (e.g., cycloalkyl having 3 to 14 carbon atoms) are preferred. It is also preferred that any of the hydrogen atoms is replaced with halogen (e.g., fluorine) or deuterium. In addition, when cycloalkyl is substituted, it may be a substitution form that forms a spiro structure, and for example, an example in which a spiro structure is formed in a cycloalkane condensed to one benzene ring (phenyl) is shown below. In each structural formula, * means a benzene ring included in the skeletal structure of the compound when it is a benzene ring, and means a bond that substitutes in the skeletal structure of the compound when it is a phenyl.

[0182] [ka]

[0183] Examples of the cycloalkane condensation include a form in which an aryl ring or a heteroaryl ring in each of rings A, B, and C in a polycyclic aromatic compound containing a structural unit represented by formula (1) is condensed with a cycloalkane, and a form in which an aryl ring or a heteroaryl ring contained in a substituent on an aryl ring or a heteroaryl ring in each of rings A, B, and C is condensed with a cycloalkane.

[0184] In addition, the polycyclic aromatic compound having the structural unit represented by formula (1) represented by formula (E ABC ) in which an aryl ring or a heteroaryl ring in each of the P ring and the Q ring in the substituent represented by the formula (I) is fused with a cycloalkane, an aryl ring or a heteroaryl ring contained in a substituent on an aryl ring or a heteroaryl ring in each of the P ring and the Q ring is fused with a cycloalkane, or an aryl ring and a heteroaryl ring in Ar are fused with a cycloalkane.

[0185] In addition, by introducing a cycloalkane structure into a polycyclic aromatic compound containing a structural unit represented by formula (1), a further decrease in melting point and sublimation temperature can be expected. This means that in sublimation purification, which is almost essential as a purification method for materials for organic devices such as organic EL elements that require high purity, purification can be performed at a relatively low temperature, so that thermal decomposition of the material can be avoided. This is also true for the vacuum deposition process, which is a powerful means for producing organic devices such as organic EL elements, and since the process can be performed at a relatively low temperature, thermal decomposition of the material can be avoided, resulting in a high-performance organic device. In addition, since the introduction of a cycloalkane structure improves solubility in organic solvents, it can also be applied to the production of elements using a coating process. However, the present invention is not particularly limited to these principles.

[0186] <Replacement with heavy stable isotopes> Unless otherwise specified, each element in the polycyclic aromatic compound containing the structural unit represented by formula (1) contains multiple naturally occurring isotopes in the natural abundance ratio. However, all or some of the elements in each structural formula may be present in an amount exceeding the natural abundance ratio (e.g., boron-11( 11 B) may contain a heavy stable isotope (at 90 atom % or more). In this specification, this is simply referred to as "substituting" a "heavy stable isotope". More specifically, at least one hydrogen can be substituted with deuterium, and at least one nitrogen can be substituted with nitrogen-15 ( 15 N), and at least one sulfur can be replaced by sulfur-33 ( 33 S), Sulfur-34( 34 S) or sulfur-36( 36 S), and at least one oxygen can be replaced by oxygen-17 ( 17 O) or oxygen-18( 18 O), and at least one carbon can be replaced by carbon-13 ( 13 C), and at least one boron can be replaced by boron-11 ( 11 B). By replacing at least some elements with heavy stable isotopes, in particular at least one boron with boron-11 ( 11 By replacing with B), it is possible to extend the life of an organic electroluminescent device using a polycyclic aromatic compound containing a structural unit represented by formula (1).

[0187] <Replacement with deuterium> All or a part of the hydrogen atoms in the polycyclic aromatic compound containing the structural unit represented by formula (1) may be deuterium atoms. The same applies to the polycyclic aromatic compound represented by formula (1X1).

[0188] For example, hydrogen atoms in the aryl or heteroaryl rings in the A, B, and C rings and in the substituents thereof may be replaced with deuterium atoms. Among these, there is an embodiment in which all or a part of the hydrogen atoms in the aryl or heteroaryl rings are replaced with deuterium atoms. ABCAll or a part of the hydrogen atoms in the P and Q rings in Ar or the aryl and heteroaryl rings in Ar may be replaced with deuterium atoms. From the viewpoint of durability, it is also preferable that all or a part of the hydrogen atoms in the polycyclic aromatic compound containing the structural unit represented by formula (1) are deuterated.

[0189] <Specific examples of polycyclic aromatic compounds> Examples of polycyclic aromatic compounds containing a structural unit represented by formula (1) include compounds represented by any of the structural formulas below. [ka]

[0190] [ka]

[0191] [ka]

[0192] [ka]

[0193] [ka]

[0194] [ka]

[0195] [ka]

[0196] [ka]

[0197]

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[0198]

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[0199]

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[0200]

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[0201]

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[0202]

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[0203]

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[0204]

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[0205]

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[0206]

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[0207]

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[0208]

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[0209]

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[0210]

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[0211]

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[0212]

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[0213]

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[0214]

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[0215]

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[0216]

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[0217]

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[0218]

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[0219]

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[0220]

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[0221]

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[0222]

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[0223]

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[0224]

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[0225]

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[0226]

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[0227]

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[0228]

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[0229] [ka]

[0230] [ka]

[0231] [ka]

[0232] [ka]

[0233] [ka]

[0234] [ka]

[0235] <Method of producing polycyclic aromatic compounds> Polycyclic aromatic compounds containing the structural unit represented by formula (1) can basically be produced by first bonding the A ring, B ring, and C ring with a bonding group (N-Ar) to produce an intermediate (first reaction), and then bonding the A ring, B ring, and C ring with boron to produce the final product (second reaction). In the first reaction, for example, a general reaction such as a nucleophilic substitution reaction or Ullmann reaction can be used for the etherification reaction, and a general reaction such as a Buchwald-Hartwig reaction, nucleophilic substitution reaction, or Goldberg amination can be used for the amination reaction. In addition, a tandem hetero Friedel-Crafts reaction (sequential aromatic electrophilic substitution reaction, the same applies below) can be used for the second reaction.

[0236] The second reaction is a reaction to introduce boron to bond the A ring, B ring, and C ring, as shown in the following scheme (1). First, the halogen atom between the nitrogen atoms is halogen-metal exchanged with n-butyllithium, sec-butyllithium, t-butyllithium, or the like. Next, boron trichloride, boron tribromide, or the like is added to perform lithium-boron metal exchange, and then a tandem boron-Friedel-Crafts reaction is carried out by adding a Bronsted base such as N,N-diisopropylethylamine to obtain the target product. In the second reaction, a Lewis acid such as aluminum trichloride may be added to promote the reaction. The halogen atom Hal in the formula may be any of Cl, Br, and I, and can be appropriately selected in consideration of the reactivity of the substrate.

[0237] [ka]

[0238] The above scheme (1) shows an example of a method for producing a polycyclic aromatic compound represented by formula (1X1). Formula (E ABC An intermediate having a group represented by the formula (I) can be synthesized with reference to the method described in WO 2015 / 102118. In addition, by appropriately selecting the raw materials to be used, it is possible to synthesize a polycyclic aromatic compound having a substituent at a desired position.

[0239] In addition, the target product can be obtained by producing a portion other than the partial structure represented by formula (X) using a method similar to that described in Advanced Material 2022, 34, 2106954, then borating it and bonding it with a halogenated form of the partial structure represented by formula (X). Alternatively, a halogenated form of a portion other than the partial structure represented by formula (X) and a borate of the partial structure represented by formula (X) may be used, and the halogen species and borate may be appropriately selected from known ones.

[0240] Specific examples of solvents that can be used in the above reactions include t-butylbenzene and xylene.

[0241] In the synthesis method of the above scheme (1), a tandem hetero Friedel-Crafts reaction was performed by halogen-metal exchange of the halogen atom between the nitrogen atoms with butyllithium or the like before adding boron trichloride, boron tribromide, or the like. However, the reaction can also be carried out by adding boron trichloride, boron tribromide, or the like to a precursor in which the halogen has been converted to hydrogen.

[0242] Examples of the ortho-metallation reagent used in the above scheme (1) include alkyllithiums such as methyllithium, n-butyllithium, sec-butyllithium, and t-butyllithium, and organic alkali metal compounds such as lithium diisopropylamide, lithium tetramethylpiperidide, lithium hexamethyldisilazide, and potassium hexamethyldisilazide.

[0243] In addition, examples of the metal-boron metal exchange reagent used in the above scheme (1) include boron halides such as boron trifluoride, boron trichloride, boron tribromide, and boron triiodide, boron alkoxylates, and boron aryloxylates.

[0244] Examples of the Bronsted base used in the above scheme (1) include N,N-diisopropylethylamine, triethylamine, 2,2,6,6-tetramethylpiperidine, 1,2,2,6,6-pentamethylpiperidine, N,N-dimethylaniline, N,N-dimethyltoluidine, 2,6-lutidine, sodium tetraphenylborate, potassium tetraphenylborate, triphenylborane, tetraphenylsilane, Ar4BNa, Ar4BK, Ar3B, and Ar4Si (Ar is an aryl such as phenyl).

[0245] Examples of Lewis acids used in the above scheme (1) include AlCl3, AlBr3, AlF3, BF3·OEt2, BCl3, BBr3, BI3, GaCl3, GaBr3, InCl3, InBr3, In(OTf)3, SnCl4, SnBr4, AgOTf, ScCl3, Sc(OTf)3, ZnCl2, ZnBr2, Zn(OTf)2, MgCl2, MgBr2, Mg(OTf)2, LiOTf, NaOTf, KOTf, Me3SiOTf, Cu(OTf)2, CuCl2, YCl3, Y(OTf)3, TiCl4, TiBr4, ZrCl4, ZrBr4, FeCl3, FeBr3, CoCl3, and CoBr3.

[0246] In the above scheme (1), a Brönsted base or Lewis acid may be used to promote the tandem hetero Friedel-Crafts reaction. However, when a boron halide such as boron trifluoride, boron trichloride, boron tribromide, or boron triiodide is used, acids such as hydrogen fluoride, hydrogen chloride, hydrogen bromide, and hydrogen iodide are generated as the aromatic electrophilic substitution reaction proceeds, so it is effective to use a Brönsted base to capture the acid. On the other hand, when an amino halide of boron or an alkoxylated product of boron is used, amines and alcohols are generated as the aromatic electrophilic substitution reaction proceeds, so it is not necessary to use a Brönsted base in many cases, but since the elimination ability of amino and alkoxy is low, it is effective to use a Lewis acid to promote the elimination.

[0247] The polycyclic aromatic compounds of the present invention also include those in which at least a portion of hydrogen atoms is substituted with deuterium or with a halogen 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 sites are deuterated, fluorinated or chlorinated.

[0248] 2. Organic Devices The polycyclic aromatic compound of the present invention can be used as a material for an organic device. Examples of the organic device include an organic electroluminescence device, an organic field effect transistor, and an organic thin-film solar cell. The polycyclic aromatic compound of the present invention is preferably used as a material for forming one or more organic layers in the organic electroluminescence device.

[0249] 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 element 100 shown in FIG. 1 has 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.

[0250] 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.

[0251] Not all of the above layers are essential, and the minimum structural unit is a structure 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 provided optionally. Each of the above layers may consist of a single layer or multiple layers.

[0252] In addition to the above-mentioned "substrate / anode / hole injection layer / hole transport layer / light-emitting layer / electron transport layer / electron injection layer / cathode" configuration, the layers constituting the organic EL element may be configured as "substrate / anode / hole transport layer / light-emitting layer / electron transport layer / electron injection layer / cathode", "substrate / anode / hole injection ...hole transport layer / light-emitting layer / electron injection layer / cathode", "substrate / anode / hole injection layer / hole transport layer / light-emitting layer / electron injection layer / cathode", or "substrate / anode / hole injection layer / hole transport layer / light-emitting layer / electron 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 transport layer / cathode", "substrate / anode / hole transport layer / light-emitting layer / electron injection 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 / 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".

[0253] The organic EL device may further have one or both of an electron blocking layer (electron blocking layer) and a hole blocking layer (hole blocking layer). The electron blocking layer has a LUMO shallower than that of the light emitting layer and a HOMO close to that of the light emitting layer or the hole transport layer, and is disposed between the light emitting layer and the hole transport layer. Since electrons remain in the light emitting layer and do not leak to the hole transport layer, it is possible to prevent a shortened life due to deterioration of the hole transport layer and a decrease in efficiency due to a decrease in recombination efficiency. The hole blocking layer has a HOMO deeper than that of the light emitting layer and a LUMO close to that of the light emitting layer or the hole transport layer, and is disposed between the light emitting layer and the electron transport layer. Since holes remain in the light emitting layer and do not leak to the electron transport layer, it is possible to prevent a shortened life due to deterioration of the electron transport layer and a decrease in efficiency due to a decrease in recombination efficiency. The hole injection / transport layer may also serve as the electron blocking layer. The electron injection / transport layer may also serve as the hole blocking layer.

[0254] The organic EL device may further have a high T1 layer. The high T1 layer has a higher T1 than the host compound, assisting dopant compound, or emitting dopant compound used in the light-emitting layer, and is disposed between the light-emitting layer and the hole transport layer and / or between the light-emitting layer and the electron blocking layer. The value of the T1 energy varies depending on the light-emitting mechanism of the device, but has a higher T1 than the compound used in the host. By having a high T1 layer around the light-emitting layer, triplet energy can be trapped and triplet energy that does not normally lead to light emission in fluorescent molecules can be converted to singlet energy, resulting in high efficiency. The hole injection / transport layer or the electron blocking layer may also serve as the high T1 layer. The electron injection / transport layer or the hole blocking layer may also serve as the high T1 layer.

[0255] The polycyclic aromatic compound of the present invention is preferably used as a material for forming a light-emitting layer or a material for forming an electron transport layer, and more preferably used as a material for forming a light-emitting layer.

[0256] 2-1-2. Substrate in organic electroluminescent device The substrate 101 is a support for the organic EL element 100, and is usually made of quartz, glass, metal, plastic, or the like. The substrate 101 is formed into a plate, film, or sheet shape depending on the purpose, and for example, a glass plate, a metal plate, a metal foil, a plastic film, a plastic sheet, or the like is used. Among them, a glass plate and a plate made of a transparent synthetic resin such as polyester, polymethacrylate, polycarbonate, or polysulfone are preferred. For a glass substrate, soda lime glass or alkali-free glass is used, and the thickness is sufficient to maintain mechanical strength. In addition, in order to improve the gas barrier property, a gas barrier film such as a dense silicon oxide film may be provided on at least one side of the substrate 101, and it is preferable to provide a gas barrier film when a plate, film, or sheet made of a synthetic resin with low gas barrier property is used as the substrate 101.

[0257] 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.

[0258] Materials for forming the anode 102 include inorganic compounds 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), polypyrrole, polyaniline, and other conductive polymers. In addition, materials that are used as anodes in organic EL elements can be appropriately selected and used.

[0259] 2-1-4. Hole injection layer and hole transport layer in organic electroluminescent device The hole injection layer 103 plays a role of efficiently injecting holes moving from the anode 102 into the light emitting layer 105 or the hole transport layer 104. The hole transport layer 104 plays a role of efficiently transporting holes injected from the anode 102 or holes injected from the anode 102 via the hole injection layer 103 to the light emitting layer 105. The hole injection layer 103 and the hole transport layer 104 are 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.

[0260] A hole injection / transport material is required to efficiently inject / 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. For this purpose, it is preferable for the material to have a small ionization potential, a large hole mobility, excellent stability, and a low probability of generating impurities that act as traps during manufacture and use.

[0261] As the material 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 elements. Specific examples of such compounds 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 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, 4,4',4"-tris(3-methylphenyl(phenyl)amino)triphenylamine and other triphenylamine derivatives, starburst amine derivatives, etc.), stilbene derivatives, phthalocyanine derivatives (metal-free, copper phthalocyanine, etc.), pyrazoline derivatives, hydrazone compounds, benzofuran derivatives, thiophene derivatives, oxadiazole derivatives, quinoxaline derivatives Conductors (e.g., 1,4,5,8,9,12-hexaazatriphenylene-2,3,6,7,10,11-hexacarbonitrile, etc.), heterocyclic compounds such as porphyrin derivatives, polysilanes, etc. As polymers, polycarbonates and styrene derivatives having the above-mentioned monomers in their side chains, polyvinylcarbazole, polysilanes, etc. are preferred, but there are no particular limitations on the compounds as long as they can form a thin film required for fabricating a light-emitting device, can inject holes from the anode, and can transport holes.

[0262] It is also known that the electrical conductivity of organic semiconductors is strongly influenced by their doping. Such organic semiconductor matrix substances consist of compounds with good electron donating or accepting properties. For doping with electron donating substances, strong electron acceptors such as tetracyanoquinone dimethane (TCNQ) or 2,3,5,6-tetrafluorotetracyano-1,4-benzoquinone dimethane (F4TCNQ) are known (see, for example, the references "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 by an electron transfer process in the electron donating base substance (hole transport substance). The conductivity of the base material varies considerably depending on the number and mobility of holes. Matrix materials having hole transport properties are known, for example, benzidine derivatives (TPD, etc.) or starburst amine derivatives (TDATA, etc.), or certain metal phthalocyanines (especially zinc phthalocyanine (ZnPc) and the like) (JP 2005-167175 A).

[0263] The above-mentioned hole injection layer material and hole transport layer material 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.

[0264] 2-1-5. Light-emitting layer in organic electroluminescent device 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 that forms the light-emitting layer 105 may be a compound that is excited and emits light by the recombination of holes and electrons (light-emitting compound), and a compound that can be formed into a stable thin film shape and shows strong luminescence (fluorescence) efficiency in a solid state is preferably used.

[0265] The light-emitting layer may be a single layer or multiple layers, each of which is formed from a material for a light-emitting layer. When the light-emitting layer is multiple layers, it is preferable that any one of the layers contains the polycyclic aromatic compound of the present invention. It is preferable that the light-emitting layer is a single layer.

[0266] The light-emitting layer is formed by 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 two or more types. For example, an emitting dopant and an assisting dopant may be used as the dopant material. In addition, it is also preferable that the light-emitting layer contains an emitting dopant and at least two selected from the group consisting of a hole-transporting host material, an electron-transporting host material, and an assisting dopant material. The dopant material may be contained in the whole of the host material or may be contained partially in the host material. As a doping method, the dopant material may be formed by a co-evaporation method with the host material, but it may also be mixed with the host material in advance and then evaporated at the same time. In addition, the light-emitting layer may also be formed by a wet film formation method using a light-emitting layer forming composition prepared by dissolving the material in an organic solvent.

[0267] The amount of the host material used varies depending on the type of the 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 material for the light-emitting layer. When the host material is a combination of a hole-transporting host material and an electron-transporting host material, the amount of the host material used is the total mass of the hole-transporting host material and the electron-transporting host material. The ratio of the amount of the hole-transporting host material to the amount of the electron-transporting host material used may be 1:9 to 9:1 by mass, preferably 4:6 to 6:4, and more preferably about 1:1.

[0268] The amount of the emitting dopant used varies depending on the type of the emitting dopant, and may be determined according to its characteristics. The amount of the emitting 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, based on the total mass of the material for the light-emitting layer. The above range is preferable in that, for example, concentration quenching phenomenon can be prevented.

[0269] In an organic electroluminescent device using an assisting dopant (thermally activated delayed fluorescent material or phosphorescent material) in addition to an emitting dopant, a low concentration of the emitting dopant material is preferable in terms of preventing concentration quenching. A high concentration of the assisting dopant is preferable in terms of energy transfer efficiency. A high concentration of the assisting dopant is preferable in terms of efficiency of the thermally activated delayed fluorescence mechanism. In an organic electroluminescent device using a thermally activated delayed fluorescent material as an assisting dopant, a low concentration of the emitting dopant is preferable compared to the assisting dopant in terms of efficiency of the thermally activated delayed fluorescence mechanism of the assisting dopant.

[0270] When an assisting dopant material is used, the amounts of the host material, the assisting dopant material, and the 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.

[0271] The polycyclic aromatic compound containing a structural unit represented by formula (1) is preferably used as a material for forming a light-emitting layer, more preferably used as a dopant, and particularly preferably used as an emitting dopant.

[0272] Polycyclic aromatic compounds containing a structural unit represented by formula (1) can be used as emitting dopants in TTF elements that utilize the phenomenon of generation of singlet excitons from multiple triplet excitons (triplet-triplet fusion (TTF)).

[0273] In addition, polycyclic aromatic compounds containing the structural unit represented by formula (1) can be used as emitting dopants in TADF elements as "thermally activated delayed fluorescent substances." In "thermally activated delayed fluorescent substances," the energy difference between the lowest excited singlet state and the lowest excited triplet state is reduced, which allows highly efficient reverse intersystem crossing from the lowest excited triplet state, which usually has a low transition probability, to the lowest excited singlet state, resulting in emission from the singlet state (thermally activated delayed fluorescence, TADF). In normal fluorescent emission, 75% of triplet excitons generated by current excitation pass through a thermal deactivation pathway and cannot be extracted as fluorescent light. On the other hand, in TADF, all excitons can be used for fluorescent emission, realizing highly efficient organic electroluminescence elements.

[0274] In general, it is said that the faster the delayed fluorescence, the better the TADF properties. Specifically, when a light-emitting material with a delayed fluorescence lifetime of 100 μsec or less is used as an emitting dopant in a light-emitting element, it can provide high device efficiency and long device life. The delayed fluorescence lifetime is preferably 20 μsec or less, more preferably less than 20 μsec, even more preferably 10 μsec or less, and most preferably 5 μsec or less.

[0275] In addition, generally, ΔE S1T1 The smaller the value, the better the TADF properties. S1T1 is the lowest excited singlet energy level (E S1 ) and the lowest excited triplet energy level (E T1 ) is the energy difference between the S1T1 The value is preferably 0.20 eV or less, more preferably 0.15 eV or less, and particularly preferably 0.10 eV or less.

[0276] <Host material> Examples of the host material include condensed ring derivatives such as anthracene and pyrene, which have been known as light emitters for a long time, bisstyryl derivatives such as bisstyryl anthracene derivatives and distyrylbenzene derivatives, tetraphenylbutadiene derivatives, cyclopentadiene derivatives, fluorene derivatives, benzofluorene derivatives, N-phenylcarbazole derivatives, carbazonitrile derivatives, and dibenzochrysene derivatives. From the viewpoint of durability, it is also preferable that some or all of the hydrogen atoms of the host material are deuterated. Furthermore, it is also preferable to form the light emitting layer by combining a host compound in which some or all of the hydrogen atoms are deuterated with a dopant compound in which some or all of the hydrogen atoms are deuterated.

[0277] 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 preferable.

[0278] [Anthracene compounds] Examples of the anthracene compound as a host include a compound represented by the formula (3-H) and a compound represented by the formula (3-H2). [ka]

[0279] In formula (3-H), X and Ar 4 are each independently hydrogen, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted diarylamino, optionally substituted diheteroarylamino, substituted or unsubstituted arylheteroarylamino, substituted or unsubstituted alkyl, optionally substituted cycloalkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkoxy, substituted or unsubstituted aryloxy, substituted or unsubstituted arylthio, or substituted silyl; all of X and Ar 4 cannot simultaneously become hydrogen. At least one hydrogen in the compound represented by formula (3-H) may be replaced by halogen, cyano, deuterium or an optionally substituted heteroaryl.

[0280] In addition, a polymer (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, and examples of X include a single bond, an arylene (phenylene, biphenylene, naphthylene, etc.), and a heteroarylene (a group having a bivalent bond such as a pyridine ring, a dibenzofuran ring, a dibenzothiophene ring, a carbazole ring, a benzocarbazole ring, and a phenyl-substituted carbazole ring).

[0281] For details of each group in the compound represented by formula (3-H), the explanation for formula (1) above can be cited, and further explanations will be given in the section on preferred embodiments below.

[0282] Preferred embodiments of the above anthracene compound are described below. The symbols in the following structures are defined as above. [ka]

[0283] In formula (3-H), X is each independently a group represented by formula (3-X1), formula (3-X2) or formula (3-X3), and the group represented by formula (3-X1), formula (3-X2) or formula (3-X3) is bonded to the anthracene ring of formula (3-H) at *. Preferably, two Xs are not simultaneously a group represented by formula (3-X3). More preferably, two Xs are not simultaneously a group represented by formula (3-X2).

[0284] In addition, a polymer (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, and examples of X include a single bond, an arylene (phenylene, biphenylene, naphthylene, etc.), and a heteroarylene (a group having a bivalent bond such as a pyridine ring, a dibenzofuran ring, a dibenzothiophene ring, a carbazole ring, a benzocarbazole ring, and a phenyl-substituted carbazole ring).

[0285] The naphthylene moieties in formula (3-X1) and formula (3-X2) may be condensed with one benzene ring. The condensed structures are as follows: [ka]

[0286] Ar 1 and Ar 2are each independently hydrogen, phenyl, biphenylyl, terphenylyl, quaterphenylyl, naphthyl, phenanthryl, fluorenyl, benzofluorenyl, chrysenyl, triphenylenyl, pyrenyl, 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 *.

[0287] Ar 3 is phenyl, biphenylyl, terphenylyl, quaterphenylyl, naphthyl, phenanthryl, fluorenyl, benzofluorenyl, chrysenyl, triphenylenyl, pyrenyl, 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.

[0288] Also, Ar 3 may have a substituent, and Ar 3 At least one hydrogen atom in 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, pyrenyl, or a group represented by formula (A) (including carbazolyl and phenyl-substituted carbazolyl). 3 is a group represented by formula (A), the group represented by formula (A) is Ar 3 and combine.

[0289] Ar 4are each independently hydrogen, phenyl, biphenylyl, terphenylyl, naphthyl, or silyl substituted with alkyl having 1 to 4 carbon atoms (eg, methyl, ethyl, t-butyl) and / or cycloalkyl having 5 to 10 carbon atoms.

[0290] Examples of the alkyl group having 1 to 4 carbon atoms that substitutes for the silyl include methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, t-butyl, and cyclobutyl, and three hydrogen atoms in the silyl are each independently substituted with these alkyl groups.

[0291] Specific examples of "silyl substituted with alkyl having 1 to 4 carbon atoms" include trimethylsilyl, triethylsilyl, tripropylsilyl, triisopropylsilyl, tributylsilyl, trisec-butylsilyl, trit-butylsilyl, ethyldimethylsilyl, propyldimethylsilyl, isopropyldimethylsilyl, butyldimethylsilyl, sec-butyldimethylsilyl, t-butyldimethylsilyl, methyldiethylsilyl, propyldiethylsilyl, isopropyldiethylsilyl, butyldiethylsilyl, sec-butyldiethylsilyl, t-butyldiethylsilyl, methyldipropylsilyl, ethyldipropylsilyl, butyldipropylsilyl, sec-butyldipropylsilyl, t-butyldipropylsilyl, methyldiisopropylsilyl, ethyldiisopropylsilyl, butyldiisopropylsilyl, sec-butyldiisopropylsilyl, t-butyldiisopropylsilyl, and the like.

[0292] Examples of the cycloalkyl having 5 to 10 carbon atoms that substitutes for the silyl include cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl, bicyclo[1.1.1]pentyl, bicyclo[2.1.0]pentyl, bicyclo[2.1.1]hexyl, bicyclo[3.1.0]hexyl, bicyclo[2.2.1]heptyl (norbornyl), bicyclo[2.2.2]octyl, adamantyl, decahydronaphthalenyl, and decahydroazulenyl, and three hydrogens in the silyl are each independently substituted with these cycloalkyls.

[0293] Specific examples of the "silyl substituted with cycloalkyl having 5 to 10 carbon atoms" include tricyclopentylsilyl and tricyclohexylsilyl.

[0294] Substituted silyls include dialkylcycloalkylsilyls, which are substituted with two alkyl groups and one cycloalkyl group, and alkyldicycloalkylsilyls, which are substituted with one alkyl group and two cycloalkyl groups. Specific examples of the alkyl and cycloalkyl groups are as described above.

[0295] In addition, hydrogen in the chemical structure of the anthracene compound represented by formula (3-H) may be substituted 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 in the compound represented by formula (3-H) at the *.

[0296] The group represented by formula (A) is one of the substituents that the anthracene compound represented by formula (3-H) may have. [ka]

[0297] In formula (A), Y is -O-, -S- or >NR 29 and R 21 ~R 28 are each independently hydrogen, optionally substituted alkyl, optionally substituted cycloalkyl, optionally substituted aryl, optionally substituted heteroaryl, optionally substituted alkoxy, optionally substituted aryloxy, optionally substituted arylthio, trialkylsilyl, tricycloalkylsilyl, dialkylcycloalkylsilyl, alkyldicycloalkylsilyl, optionally substituted amino, halogen, hydroxy or cyano; R 21 ~R 28adjacent groups among R may be bonded to each other to form a hydrocarbon ring, an aryl ring, or a heteroaryl ring; 29 is hydrogen or optionally substituted aryl. In formula (A), Y is preferably --O--.

[0298] R 21 ~R 28 Among these, adjacent groups may be bonded to each other to form a hydrocarbon ring, an aryl ring, or a heteroaryl ring. The group represented by the following formula (A-1) does not form a ring, and the group represented by the following formulas (A-2) to (A-14) may be exemplified as the group formed with a ring. At least one hydrogen atom in the group represented by any of formulas (A-1) to (A-14) may be substituted with alkyl, cycloalkyl, aryl, heteroaryl, alkoxy, aryloxy, arylthio, trialkylsilyl, tricycloalkylsilyl, dialkylcycloalkylsilyl, alkyldicycloalkylsilyl, diaryl (two aryls may be bonded to each other via a linking group), substituted amino, diheteroaryl substituted amino, arylheteroaryl substituted amino, halogen, hydroxy, or cyano.

[0299] [ka]

[0300] Examples of rings formed by bonding adjacent groups to each other include a hydrocarbon ring such as a cyclohexane ring, and examples of aryl and heteroaryl rings include the above-mentioned R 21 ~R 28 Examples of the ring structures include those described in "aryl" and "heteroaryl" in the formula (A-1), and these rings are formed so as to be condensed with one or two benzene rings in the formula (A-1).

[0301] The group represented by formula (A) is a group obtained by removing one hydrogen atom from any position of formula (A), and * indicates the position. In other words, the group represented by formula (A) may have any position as a bonding position. For example, any carbon atom on the two benzene rings in the structure of formula (A), R 21 ~R 28 An atom on any ring formed by bonding adjacent groups to each other, or ">NR 29 " R in 29 Any position in the 29 " in N(R 29 is a bond). The same applies to the groups represented by any of the formulae (A-1) to (A-14).

[0302] Examples of the group represented by formula (A) include groups represented by any of formulas (A-1) to (A-14). Groups represented by any of formulas (A-1) to (A-5) and (A-12) to (A-14) are preferred. Groups represented by any of formulas (A-1) to (A-4) are more preferred. Groups represented by any of formulas (A-1), (A-3) and (A-4) are even more preferred. Groups represented by formula (A-1) are particularly preferred.

[0303] Examples of the group represented by formula (A) include the following groups: In the formula, Y and * are defined as above. [ka]

[0304] [ka]

[0305] In the compound represented by formula (3-H), the group represented by formula (A) is a naphthalene ring in formula (3-X1) or formula (3-X2), a single bond in formula (3-X3), and Ar in formula (3-X3). 3 Preferably, the compound is combined with any one of the following:

[0306] All or a part of the hydrogen atoms in the chemical structure of the anthracene compound represented by formula (3-H) may be deuterium atoms.

[0307] The anthracene compound as the host may be, for example, a compound represented by the following formula (3-H2). [ka]

[0308] In formula (3-H2), Ar c is optionally substituted aryl or optionally substituted heteroaryl, R c is hydrogen, alkyl, or cycloalkyl; Ar 11 , Ar 12 , Ar 13 , Ar 14 , Ar 15 , Ar 16 , Ar 17 , and Ar 18 are each independently hydrogen, optionally substituted aryl, optionally substituted heteroaryl, optionally substituted diarylamino, optionally substituted diheteroarylamino, optionally substituted arylheteroarylamino, optionally substituted alkyl, optionally substituted cycloalkyl, optionally substituted alkenyl, optionally substituted alkoxy, optionally substituted aryloxy, optionally substituted arylthio, or optionally substituted silyl, and at least one hydrogen in the compound represented by formula (3-H2) is optionally substituted with halogen, cyano, or deuterium.

[0309] In formula (3-H2), the definitions of "optionally substituted aryl", "optionally substituted heteroaryl", "optionally substituted diarylamino", "optionally substituted diheteroarylamino", "optionally substituted arylheteroarylamino", "optionally substituted alkyl", "optionally substituted cycloalkyl", "optionally substituted alkenyl", "optionally substituted alkoxy", "optionally substituted aryloxy", "optionally substituted arylthio", and "optionally substituted silyl" are the same as those shown in formula (3-H) above, and the explanation in formula (3-H) can be cited.

[0310] The "optionally substituted aryl" is also preferably a group represented by any one of the following formulae (3-H2-X1) to (3-H2-X8).

[0311] [ka]

[0312] In formulae (3-H2-X1) to (3-H2-X8), * indicates a bond position. In formulae (3-H2-X1) to (3-H2-X3), Ar 21 , Ar 22 , and Ar 23 are each independently hydrogen, phenyl, biphenylyl, terphenylyl, quaterphenylyl, naphthyl, phenanthryl, fluorenyl, benzofluorenyl, chrysenyl, triphenylenyl, pyrenyl, anthracenyl, or a group represented by formula (A). In the explanation of formula (3-H2), the group represented by formula (A) is the same as that explained in the anthracene compound represented by formula (3-H).

[0313] In the formulae (3-H2-X4) to (3-H2-X8), Ar 24 , Ar 25 , Ar 26 , Ar 27 , Ar 28 , Ar 29 , and Ar30 are each independently hydrogen, phenyl, biphenylyl, terphenylyl, naphthyl, phenanthryl, fluorenyl, chrysenyl, triphenylenyl, pyrenyl, or a group represented by formula (A). In addition, any one or more hydrogen atoms in each of the groups represented by formulas (3-H2-X1) to (3-H2-X8) may be substituted with an alkyl group having 1 to 6 carbon atoms (preferably methyl or t-butyl).

[0314] Furthermore, preferred examples of the "optionally substituted aryl" include terphenylyl (particularly m-terphenyl-5'-yl) which may be substituted with one or more substituents selected from the group consisting of phenyl, biphenylyl, terphenylyl, naphthyl, phenanthryl, fluorenyl, chrysenyl, triphenylenyl, pyrenyl, and a group represented by formula (A).

[0315] The "optionally substituted heteroaryl" also includes a group represented by formula (A). In addition, specific examples of the "optionally substituted aryl" and the "optionally substituted heteroaryl" include dibenzofuryl, naphthobenzofuryl, and phenyl-substituted dibenzofuryl.

[0316] At least one hydrogen atom in the compound represented by formula (3-H2) may be replaced by a halogen atom, a cyano atom, or a deuterium atom. In this case, "halogen" includes fluorine, chlorine, bromine, and iodine. In particular, the compound represented by formula (3-H2) in which all hydrogen atoms are replaced by deuterium atoms is preferred.

[0317] In formula (3-H2), R c is hydrogen, alkyl, or cycloalkyl, preferably hydrogen, methyl, or t-butyl, and more preferably hydrogen. In formula (3-H2), Ar 11 ~Ar 18It is preferable that at least two of the substituents are optionally substituted aryl or optionally substituted heteroaryl. That is, it is preferable that the anthracene compound represented by formula (3-H2) has a structure in which at least three substituents selected from the group consisting of optionally substituted aryl and optionally substituted heteroaryl are bonded to the anthracene ring.

[0318] The anthracene compound represented by formula (3-H2) is Ar 11 ~Ar 18 It is more preferable that two of the substituents are optionally substituted aryl or optionally substituted heteroaryl, and the other six are hydrogen, optionally substituted alkyl, optionally substituted cycloalkyl, optionally substituted alkenyl, or optionally substituted alkoxy. That is, it is more preferable that the anthracene compound represented by formula (3-H2) has a structure in which three substituents selected from the group consisting of optionally substituted aryl and optionally substituted heteroaryl are bonded to the anthracene ring.

[0319] The anthracene compound represented by formula (3-H2) is Ar 11 ~Ar 18 It is more preferred that any two of are optionally substituted aryl or optionally substituted heteroaryl, and the other six are hydrogen, methyl, or t-butyl.

[0320] Furthermore, in formula (3-H2), R c is hydrogen and Ar 11 ~Ar 18 It is preferred that any six of these are hydrogen.

[0321] The anthracene compound represented by formula (3-H2) is preferably an anthracene compound represented by the following formula (3-H2-A), (3-H2-B), (3-H2-C), (3-H2-D), or (3-H2-E). [ka]

[0322] In the formula (3-H2-A), (3-H2-B), (3-H2-C), (3-H2-D) or (3-H2-E), Ar c ', Ar 11 ', Ar 12 ', Ar 13 ', Ar 14 ', Ar 15 ', Ar 17 ', and Ar 18 ' are each independently phenyl, biphenylyl, terphenylyl, quaterphenylyl, naphthyl, phenanthryl, fluorenyl, benzofluorenyl, chrysenyl, triphenylenyl, pyrenyl, or a group represented by formula (A), and at least one hydrogen atom in these groups may be substituted with phenyl, biphenylyl, terphenylyl, quaterphenylyl, naphthyl, phenanthryl, fluorenyl, benzofluorenyl, chrysenyl, triphenylenyl, pyrenyl, or a group represented by formula (A). Here, when both hydrogen atoms of the methylene in fluorenyl and benzofluorenyl are substituted with phenyl, these phenyls may be bonded to each other by a single bond. Ar c ', Ar 11 ', Ar 12 ', Ar 13 ', Ar 14 ', Ar 15 ', Ar 17 ', and Ar 18 Carbon atoms of the anthracene ring that are not bonded with ' may have methyl or t-butyl bonded instead of hydrogen.

[0323] Ar c ', Ar 11 ', Ar 12 ', Ar 13 ', Ar 14 ', Ar 15 ', Ar 17 ', and Ar 18 When each of "1" and "2" is a substituted or unsubstituted phenyl or a substituted or unsubstituted naphthyl, it is preferably a group represented by any one of the above formulae (3-H2-X1) to (3-H2-X8).

[0324] Ar c ', Ar 11 ', Ar 12 ', Ar 13 ', Ar 14 ', Ar 15 ', Ar 17 ', and Ar 18 More preferably, each ' is independently phenyl, biphenylyl (particularly biphenyl-2-yl or biphenyl-4-yl), terphenylyl (particularly m-terphenyl-5'-yl), naphthyl, phenanthryl, fluorenyl, or a group represented by any one of the above formulas (A-1) to (A-4), and in this case, at least one hydrogen atom in these groups may be substituted by phenyl, biphenylyl, naphthyl, phenanthryl, fluorenyl, or a group represented by any one of the above formulas (A-1) to (A-4).

[0325] In addition, at least one hydrogen atom in the compound represented by formula (3-H2-A), (3-H2-B), (3-H2-C), (3-H2-D), or (3-H2-E) may be replaced with a halogen atom, a cyano atom, or a deuterium atom. A deuterated form is preferable, and a form in which all anthracene rings are deuterated or a form in which all hydrogen atoms are deuterated is preferable.

[0326] Particularly preferred anthracene compounds represented by formula (3-H2) include those represented by formula (3-H2-Aa) below. [ka]

[0327] In formula (3-H2-Aa), Ar c ', Ar 14 ', and Ar 15Each of the ' is independently phenyl, biphenylyl, terphenylyl, naphthyl, phenanthryl, fluorenyl, benzofluorenyl, chrysenyl, triphenylenyl, pyrenyl, or a group represented by any one of the above formulas (A-1) to (A-11), and at least one hydrogen atom in these groups may be substituted with phenyl, biphenylyl, terphenylyl, naphthyl, phenanthryl, fluorenyl, benzofluorenyl, chrysenyl, triphenylenyl, pyrenyl, or a group represented by any one of the formulas (A-1) to (A-11). Here, when both hydrogen atoms of the methylene in the fluorenyl and benzofluorenyl are substituted with phenyl, these phenyls may be bonded to each other by a single bond. In addition, Ar c ', Ar 14 ', and Ar 15 A carbon atom on the anthracene ring to which ' is not bonded may be substituted with methyl or t-butyl instead of hydrogen. At least one hydrogen in the compound represented by formula (3-H2-Aa) may be substituted with halogen or cyano, and at least one hydrogen in the compound represented by formula (3-H2-Aa) is substituted with deuterium.

[0328] In formula (3-H2-Aa), Ar c ', Ar 14 ', and Ar 15 Each ' is preferably independently phenyl, biphenylyl, terphenylyl, naphthyl, phenanthryl, fluorenyl, or a group represented by any one of the above formulas (A-1) to (A-4), and at least one hydrogen in these groups may be substituted by phenyl, naphthyl, phenanthryl, fluorenyl, or a group represented by any one of the above formulas (A-1) to (A-4).

[0329] In the compound represented by formula (3-H2-Aa), at least the carbon at the 10-position of the anthracene ring (Ar cIt is preferable that the hydrogen bonded to the carbon atom to which Ar′ is bonded (the carbon atom to which Ar′ is bonded is the 9th position) is replaced with deuterium. That is, the compound represented by formula (3-H2-Aa) is preferably a compound represented by the following formula (3-H2-Ab). In formula (3-H2-Ab), D is deuterium, and c ', Ar 14 ', and Ar 15 ' is the same as defined in formula (3-H2-Aa). D in formula (3-H2-Ab) indicates that at least this position is deuterium, and any one or more other hydrogens in formula (3-H2-Ab) may be deuterium at the same time, and it is also preferable that all hydrogens in formula (3-H2-Ab) are deuterium.

[0330] [ka]

[0331] Specific examples of anthracene compounds include compounds represented by formulae (3-131-Y) to (3-182-Y), (3-183-N), (3-184-Y) to (3-284-Y), (3-500) to (3-557), (3-600) to (3-605), and (3-606-Y) to (3-626-Y). Hydrogen atoms in these formulae may be partially or completely replaced with deuterium, and particularly preferred forms of deuterium replacement are listed individually. Y in the formulae is -O-, -S-, >NR 29 (R 29 is defined as above) or >C(-R 30 )2(R 30 R may be either an optionally linked aryl or an alkyl; 29 For example, phenyl, R 30 For example, is methyl. For formula numbers, for example, when Y is O, formula (3-131-Y) is formula (3-131-O), and Y is -S- or >NR 29 In the case of (3-131-S) or (3-131-N), respectively, use formula (3-131-S) or formula (3-131-N).

[0332]

change

[0333]

change

[0334]

change

[0335]

change

[0336]

change

[0337]

change

[0338]

change

[0339]

change

[0340]

change

[0341]

change

[0342]

change

[0343] [ka]

[0344] [ka]

[0345] [ka]

[0346] [ka]

[0347] [ka]

[0348] [ka]

[0349] [ka]

[0350] [ka]

[0351] [ka] In the above formula, D is deuterium.

[0352] Among these compounds, the compounds of formula (3-131-Y) to formula (3-134-Y), formula (3-138-Y), formula (3-140-Y) to formula (3-143-Y), formula (3-150-Y), formula (3-153-Y) to formula (3-156-Y), formula (3-166-Y), formula (3-168-Y), formula (3-173-Y), formula (3-177-Y), formula (3-180-Y) to formula (3-183-N), formula (3-185-Y), formula (3-190-Y), formula (3-223-Y), formula (3-241- Y), the formula (3-250-Y), the formula (3-252-Y) to the formula (3-254-Y), the formula (3-270-Y) to the formula (3-284-Y), the formula (3-501), the formula (3-507), the formula (3-508), the formula (3-509), the formula (3-513), the formula (3-514), the formula (3-519), the formula (3-521), the formula (3-538) to the formula (3-547), or the formula (3-600) to the formula (3-605), and the formula (3-606-Y) to the formula (3-626-Y) are preferable. In addition, Y is -O- or >NR 29 is preferred, and -O- is more preferred. Deuterium-substituted forms are also preferred.

[0353] The above anthracene compound is a compound having a reactive group at a desired position of the anthracene skeleton, and an anthracene compound represented by formula (3-H) is a compound having X, Ar 4 The compound having a reactive group in a partial structure such as the structure of formula (A) can be used as a starting material to produce the compound by applying Suzuki coupling, Negishi coupling, or other known coupling reactions. Examples of reactive groups in these reactive compounds include halogens and boronic acids. As a specific production method, for example, the synthesis methods in paragraphs

[0089] to

[0175] of International Publication No. 2014 / 141725 can be used as a reference.

[0354] [Fluorene compounds] The compound represented by formula (4-H) basically functions as a host. [ka]

[0355] In formula (4-H), R 1 From R 10 are each independently hydrogen, aryl, heteroaryl (the heteroaryl may be bonded to the fluorene skeleton in formula (4-H) via a single bond or a linking group), diarylamino, diheteroarylamino, arylheteroarylamino, alkyl, cycloalkyl, alkenyl, alkoxy, or aryloxy, in which at least one hydrogen may be replaced by an aryl, heteroaryl, alkyl, or cycloalkyl; and R 1 and R 2 , R 2 and R 3 , R 3 and R 4 , R 5 and R 6 , R 6 and R 7 , R 7 and R 8 or R 9 and R 10 may each independently bond to form a fused ring or a spiro ring, and at least one hydrogen in the formed ring may be substituted with an aryl, a heteroaryl (the heteroaryl may be bonded to the formed ring via a single bond or a linking group), a diarylamino, a diheteroarylamino, an arylheteroarylamino, an alkyl, a cycloalkyl, an alkenyl, an alkoxy, or an aryloxy, and at least one hydrogen in these may be substituted with an aryl, a heteroaryl, an alkyl, or a cycloalkyl, and at least one hydrogen in the compound represented by formula (4-H) may be substituted with a halogen, a cyano, or a deuterium.

[0356] For details of each group in the definition of formula (4-H), the explanation for formula (1) above can be cited.

[0357] R 1 From R 10Examples of the alkenyl in the above formula include alkenyl having 2 to 30 carbon atoms, preferably alkenyl having 2 to 20 carbon atoms, more preferably alkenyl having 2 to 10 carbon atoms, further preferably alkenyl having 2 to 6 carbon atoms, and particularly preferably alkenyl having 2 to 4 carbon atoms. Preferred alkenyls are vinyl, 1-propenyl, 2-propenyl, 1-butenyl, 2-butenyl, 3-butenyl, 1-pentenyl, 2-pentenyl, 3-pentenyl, 4-pentenyl, 1-hexenyl, 2-hexenyl, 3-hexenyl, 4-hexenyl, or 5-hexenyl.

[0358] Specific examples of heteroaryl include monovalent groups represented by removing any one hydrogen atom from a compound of the following formula (4-Ar1), formula (4-Ar2), formula (4-Ar3), formula (4-Ar4), or formula (4-Ar5).

[0359] [ka]

[0360] In formulas (4-Ar1) to (4-Ar5), Y 1 are each independently O, S or NR, R is phenyl, biphenylyl, naphthyl, anthracenyl or hydrogen, and at least one hydrogen in the structures of formulae (4-Ar1) to (4-Ar5) may be substituted with phenyl, biphenylyl, naphthyl, anthracenyl, phenanthryl, methyl, ethyl, propyl, or butyl.

[0361] These heteroaryls may be bonded to the fluorene skeleton in formula (4-H) via a single bond or a linking group. That is, the fluorene skeleton in formula (4-H) and the above heteroaryls may be bonded directly, or may be bonded to each other via a linking group. Examples of the linking group include phenylene, biphenylene, naphthylene, anthracenylene, methylene, ethylene, -OCH2CH2-, -CH2CH2O-, or -OCH2CH2O-.

[0362] In addition, R in formula (4-H) 1 and R 2 , R 2 and R 3 , R 3 and R 4 , R 5 and R 6 , R 6 and R 7 or R 7 and R 8 are each independently bonded to form a fused ring, R 9 and R 10 may be bonded to form a spiro ring. 1 From R 8 The fused ring formed by is a ring fused to the benzene ring in formula (4-H), and is an aliphatic ring or an aromatic ring. An aromatic ring is preferable, and examples of the structure including the benzene ring in formula (4-H) include a naphthalene ring and a phenanthrene ring. 9 and R 10 The spiro ring formed by the formula (4-H) is a ring that is spiro-bonded to the five-membered ring in formula (4-H), and is an aliphatic ring or an aromatic ring. An aromatic ring, such as a fluorene ring, is preferred.

[0363] The compound represented by formula (4-H) is preferably a compound represented by the following formula (4-H-1), formula (4-H-2) or formula (4-H-3), 1 and R 2 In the formula (4-H), R 3 and R 4 In the formula (4-H), R 1 From R 8 is a compound in which none of the above is bound.

[0364] [ka]

[0365] R in formula (4-H-1), formula (4-H-2) and formula (4-H-3) 1From R 10 The definition of R in formula (4-H) corresponds to 1 From R 10 is the same as R in formula (4-H-1) and formula (4-H-2). 11 From R 14 The definition of R in formula (4-H) 1 From R 10 is the same as:

[0366] The compound represented by formula (4-H) is more preferably a compound represented by the following formula (4-H-1A), formula (4-H-2A) or formula (4-H-3A), in which R 9 and R 10 is a compound in which a spiro-fluorene ring is formed by bonding.

[0367] [ka]

[0368] R in formula (4-H-1A), formula (4-H-2A) and formula (4-H-3A) 2 From R 7 The definition of is the corresponding R in formula (4-H-1), formula (4-H-2) and formula (4-H-3). 2 From R 7 is the same as R in formula (4-H-1A) and formula (4-H-2A). 11 From R 14 The definition of R in formula (4-H-1) and formula (4-H-2) is also 11 From R 14 is the same as:

[0369] In addition, all or a part of the hydrogen atoms in the compound represented by formula (4-H) may be substituted with halogen, cyano or deuterium.

[0370] More specific examples of the fluorene compound as a host include compounds represented by the following structural formulas. [ka]

[0371] [Dibenzochrysene compounds] The dibenzochrysene compound as the host is, for example, a compound represented by the following formula (5-H). [ka]

[0372] In formula (5-H), R 1 From R 16 are each independently hydrogen, aryl, heteroaryl (the heteroaryl may be bonded to the dibenzochrysene skeleton in formula (5-H) via a single bond or a linking group), diarylamino, diheteroarylamino, arylheteroarylamino, alkyl, cycloalkyl, alkenyl, alkoxy, or aryloxy, in which at least one hydrogen may be replaced by an aryl, heteroaryl, alkyl, or cycloalkyl; and R 1 From R 16 Adjacent groups among these may be bonded to each other to form a fused ring, and at least one hydrogen atom in the formed ring may be substituted with an aryl, a heteroaryl (the heteroaryl may be bonded to the formed ring via a single bond or a linking group), a diarylamino, a diheteroarylamino, an arylheteroarylamino, an alkyl, a cycloalkyl, an alkenyl, an alkoxy, or an aryloxy, and at least one hydrogen atom in these may be substituted with an aryl, a heteroaryl, an alkyl, or a cycloalkyl, and at least one hydrogen atom in the compound represented by formula (5-H) may be substituted with a halogen, a cyano, or a deuterium.

[0373] For details of each group in the definition of formula (5-H), the explanation for formula (1) above can be cited.

[0374] The alkenyl in the definition of formula (5-H) is, for example, an alkenyl having 2 to 30 carbon atoms, preferably an alkenyl having 2 to 20 carbon atoms, more preferably an alkenyl having 2 to 10 carbon atoms, further preferably an alkenyl having 2 to 6 carbon atoms, and particularly preferably an alkenyl having 2 to 4 carbon atoms. Preferred alkenyls are vinyl, 1-propenyl, 2-propenyl, 1-butenyl, 2-butenyl, 3-butenyl, 1-pentenyl, 2-pentenyl, 3-pentenyl, 4-pentenyl, 1-hexenyl, 2-hexenyl, 3-hexenyl, 4-hexenyl, or 5-hexenyl.

[0375] Specific examples of heteroaryl include monovalent groups represented by removing any one hydrogen atom from a compound of the following formula (5-Ar1), formula (5-Ar2), formula (5-Ar3), formula (5-Ar4), or formula (5-Ar5).

[0376] [ka]

[0377] In formula (5-Ar1) to formula (5-Ar5), Y 1 are each independently O, S or NR, R is phenyl, biphenylyl, naphthyl, anthracenyl or hydrogen, and at least one hydrogen in the structures of formulae (5-Ar1) to (5-Ar5) may be substituted with phenyl, biphenylyl, naphthyl, anthracenyl, phenanthryl, methyl, ethyl, propyl, or butyl.

[0378] These heteroaryls may be bonded to the dibenzochrysene skeleton in formula (5-H) via a single bond or a linking group. That is, the dibenzochrysene skeleton and the heteroaryl in formula (5-H) may be bonded directly or via a linking group. Examples of the linking group include phenylene, biphenylene, naphthylene, anthracenylene, methylene, ethylene, -OCH2CH2-, -CH2CH2O-, or -OCH2CH2O-.

[0379] The compound represented by formula (5-H) is preferably R 1 , R 4 , R 5 , R 8 , R 9 , R 12 , R 13 and R 16 is hydrogen. In this case, R in formula (5-H) 2 , R 3 , R 6 , R 7 , R 10 , R 11 , R 14 and R 15 are preferably each independently hydrogen, phenyl, biphenylyl, naphthyl, anthracenyl, phenanthryl, a monovalent group having a structure of formula (5-Ar1), formula (5-Ar2), formula (5-Ar3), formula (5-Ar4) or formula (5-Ar5) (the monovalent group having the structure may be bonded to the dibenzochrysene skeleton in formula (5-H) via phenylene, biphenylene, naphthylene, anthracenylene, methylene, ethylene, -OCHCH-, -CHCHO- or -OCHCHO-), methyl, ethyl, propyl or butyl.

[0380] The compound represented by formula (5-H) is more preferably 1 , R 2 , R 4 , R 5 , R 7 , R 8 , R 9 , R 10 , R 12 , R 13 , R 15 and R 16 is hydrogen. In this case, R in formula (5-H) 3 , R 6 , R 11 and R 14At least one (preferably one or two, more preferably one) of the above is a single bond, phenylene, biphenylene, naphthylene, anthracenylene, methylene, ethylene, -OCH2CH2-, -CH2CHO-, or a monovalent group having a structure of formula (5-Ar1), (5-Ar2), (5-Ar3), (5-Ar4) or (5-Ar5) via -OCH2CHO-, and the other (i.e., other than the position where the monovalent group having the above structure is substituted) is hydrogen, phenyl, biphenylyl, naphthyl, anthracenyl, methyl, ethyl, propyl, or butyl, and at least one hydrogen in these may be substituted with phenyl, biphenylyl, naphthyl, anthracenyl, methyl, ethyl, propyl, or butyl.

[0381] In addition, R in formula (5-H) 2 , R 3 , R 6 , R 7 , R 10 , R 11 , R 14 and R 15 When a monovalent group having a structure represented by formula (5-Ar1) to formula (5-Ar5) is selected as the aryl group, at least one hydrogen atom in the structure is selected from the group represented by formula (5-Ar1) to formula (5-Ar5). 1 From R 16 may be bonded to any one of the following to form a single bond.

[0382] More specific examples of the dibenzochrysene compound as a host include compounds represented by the following structural formulas. [ka]

[0383] [ka]

[0384] [Compounds represented by any of formulas (H1), (H2) and (H3)] As the host material, for example, a compound represented by any one of the following formulas (H1), (H2), and (H3) can be used. [ka]

[0385] In formulas (H1), (H2) and (H3), L 1 is a single bond or a divalent group containing at least an arylene or heteroarylene. 1 L may be a single bond, or a divalent group formed by linking any two of these with -O-, -S-, -CH2-, -Si(-Arx)2- (Arx is aryl), or cycloalkylene. 1 The arylene in the formula (I) is preferably an arylene having 6 to 16 carbon atoms, more preferably an arylene having 6 to 12 carbon atoms, and particularly preferably an arylene having 6 to 10 carbon atoms. Specific examples of the arylene include divalent groups such as a benzene ring, a biphenyl ring, a terphenyl ring, and a fluorene ring. 1The heteroarylene therein is preferably a heteroarylene having 2 to 24 carbon atoms, more preferably a heteroarylene having 2 to 20 carbon atoms, still more preferably a heteroarylene having 2 to 15 carbon atoms, and particularly preferably a heteroarylene having 2 to 10 carbon atoms. Specific examples thereof include a pyrrole ring, an oxazole ring, an isoxazole ring, a thiazole ring, an isothiazole ring, an imidazole ring, an oxadiazole ring (such as a furazan ring), a thiadiazole ring, a triazole ring, a tetrazole ring, a pyrazole ring, a pyridine ring, a pyrimidine ring, a pyridazine ring, a pyrazine ring, a triazine ring, an indole ring, and an isoindole ring. , 1H-indazole ring, benzimidazole ring, benzoxazole ring, benzothiazole ring, 1H-benzotriazole ring, quinoline ring, isoquinoline ring, cinnoline ring, quinazoline ring, quinoxaline ring, phthalazine ring, naphthyridine ring, purine ring, pteridine ring, carbazole ring, acridine ring, phenoxathiin ring, phenoxazine ring, phenothiazine ring, phenazine ring, indolizine ring, furan ring, benzofuran ring, isobenzofuran ring, dibenzofuran ring, thiophene ring, benzothiophene ring, dibenzothiophene ring, and thianthrene ring. At least one hydrogen atom in the compound represented by each of the above formulae may be substituted with at least one group selected from the substituent group Z or deuterium, for example, alkyl having 1 to 6 carbon atoms, cyano, halogen, or deuterium.

[0386] Preferred specific examples include compounds represented by any of the structural formulas listed below. In the structural formulas listed below, at least one hydrogen may be substituted with halogen, cyano, alkyl having 1 to 4 carbon atoms (e.g., methyl or t-butyl), phenyl, naphthyl, or the like.

[0387] [ka]

[0388] [ka]

[0389] [ka]

[0390] [ka]

[0391] [Hole-transporting host material (HH) and electron-transporting host material (EH)] The hole-transporting host material (HH) and the electron-transporting host material (EH) satisfy the following relationship with respect to the HOMO (Highest Occupied Molecular Orbital) and the LUMO (Lowest Unoccupied Molecular Orbital). The HOMO of the hole-transporting host material (HH) is shallower than the HOMO of the electron-transporting host material (EH), and the LUMO of the electron-transporting host material (EH) is deeper than the LUMO of the hole-transporting host material (HH). It is also preferable that the HOMO of the emitting dopant is shallower than the HOMO of the hole-transporting host material (HH), or the LUMO of the emitting dopant is deeper than the LUMO of the electron-transporting host material (EH).

[0392] In addition, the lowest excited triplet energy level (E T1 ) is the highest E in the emission layer from the viewpoint of promoting TADF generation in the emission layer without inhibiting it. T1 E of an emitting dopant or an assisting dopant having T1 It is preferable that the E T1 is the E of the emitting dopant or assisting dopant mentioned above. T1 It is preferably 0.01 eV or more higher than the E of the host material, more preferably 0.03 eV or more higher, and further preferably 0.1 eV or more higher. T1is preferably 2.47 eV or more, more preferably 2.49 eV or more, and even more preferably 2.56 eV or more.

[0393] It is also preferable to use a hole-transporting host material in the hole-transporting layer adjacent to the light-emitting layer, and an electron-transporting host material in the electron-transporting layer adjacent to the light-emitting layer. This is because carrier leakage and energy leakage from the light-emitting layer to the adjacent layer are less likely to occur, and a highly efficient organic EL device can be obtained. The host material (hole-transporting host material) in the light-emitting layer and the material of the hole-transporting layer may be the same or different. Also, the host material (electron-transporting host material) in the light-emitting layer and the material of the electron-transporting layer may be the same or different.

[0394] A preferred example of the hole transporting host material (HH) is a compound represented by formula (HH-1) or having a partial structure represented by formula (HH-1) and a structure containing at least three rings selected from the group consisting of aryl rings and heteroaryl rings. This compound preferably does not contain any of an imine structure (-N=C-; including a partial structure of a heteroaryl ring), boron (>B-), and cyano (CN).

[0395] [ka]

[0396] In formula (HH-1), Q is >O, >S, or >NA H and In the formula (HH-1), one carbon atom adjacent to the carbon atom to which Q is bonded in each of the two phenyls may be bonded to each other via L, L is a single bond, >O, >S, or >C(-A H )2, A H is hydrogen, aryl, or heteroaryl, and >C(-A H )2 in two A H may be bonded to each other.

[0397] When the hole transporting host material contains the structure represented by formula (HH-1) as a partial structure, it may contain one of the partial structures, but it is also preferable to contain two or more of the partial structures. When it contains two or more, the two or more partial structures may be the same or different from each other. The two or more partial structures may be bonded to each other by a single bond, may be bonded so that any ring contained in the partial structure is shared, or may be bonded so that any ring contained in the partial structure is condensed. The partial structure may further have a substituent selected from aryl, heteroaryl, diarylamino, or aryloxy.

[0398] The compound represented by the above formula (HH-1) or having a partial structure represented by formula (HH-1) has a structure containing at least three rings selected from the group consisting of aryl rings and heteroaryl rings. The number of rings contained is preferably 6 or more, more preferably 8 or more. In addition, it is preferably 20 or less, more preferably 15 or less, and even more preferably 10 or less. The number of rings means the number of monocyclic rings, and for condensed rings, it is the number of monocyclic rings constituting the condensed rings.

[0399] 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 condensed polycyclic ring containing phenoxazine or phenothiazine. The hole transporting host material may contain one such partial structure, but it is also preferable to contain two or more of them. When two or more are contained, the two or more partial structures may be the same or different from each other.

[0400] Specific examples of the hole-transporting host material include the following compounds. [ka]

[0401] [ka]

[0402]

change

[0403]

change

[0404]

change

[0405]

change

[0406]

change

[0407]

change

[0408]

change

[0409]

change

[0410]

change

[0411]

change

[0412] [ka]

[0413] 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, HH-1-106 to HH-1-108, and HH-1-109 to HH-1-115 are preferred.

[0414] Examples of the electron-transporting host material (EH) include compounds represented by formulae (EH-1A) to (EH-1D) or compounds having a partial structure represented by formulae (EH-1A) to (EH-1D) and a structure including at least three rings selected from the group consisting of aryl rings and heteroaryl rings.

[0415] [ka]

[0416] In formulas (EH-1A) to (EH-1D), Ar is a heteroaryl ring containing N=C as a ring-constituting moiety; Z is a single bond, -O-, -S-, or -N(-A E )-and The carbon atom next to the carbon atom to which Z is bonded and the A to which Z is bonded E and may be bonded to each other via L, L is a single bond, >O, >S or >C(-A E )2, A E is aryl, heteroaryl, or triarylsilyl, and in formula (EH-1C), any one of A E may be diarylamino; Two A's bonded to the same atom E may be bonded to each other via L, X is C, P or S; When X is C, n=2, m=1, When X is P, n=3, m=1, When X is S, n=2 and m=1~2.

[0417] The compounds represented by the above formulae (EH-1A) to (EH-1D) or having a partial structure represented by the formulae (EH-1A) to (EH-1D) have a structure containing at least three rings selected from the group consisting of aryl rings and heteroaryl rings. The number of rings contained is preferably 4 or more, more preferably 6 or more, and even more preferably 8 or more. In addition, it is preferably 20 or less, more preferably 15 or less, and even more preferably 10 or less. The number of rings means the number of monocyclic rings, and for fused rings, it is the number counting the monocyclic rings constituting the fused rings.

[0418] When the electron transporting host material contains the structures represented by formulae (EH-1A) to (EH-1D) as partial structures, it may contain one of these partial structures, but it is also preferable to contain two or more of them. When it contains two or more, the two or more partial structures may be the same or different from each other. The two or more partial structures may be bonded to each other by a single bond, may be bonded so that any ring contained in the partial structure is shared, or may be bonded so that any ring contained in the partial structure is condensed. The partial structure may further have a substituent selected from aryl, heteroaryl, diarylamino, or aryloxy.

[0419] Specific examples of the electron transporting host material include the following compounds. [ka]

[0420] [ka]

[0421] [ka]

[0422] [ka]

[0423] [ka]

[0424] [ka]

[0425] [ka]

[0426] [ka]

[0427] [ka]

[0428] 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 formula (EH-1b) below, or a polymer of a polycyclic aromatic compound having a plurality of structures represented by formula (EH-1b) below. [ka]

[0429] In formula (EH-1b), R 1 , R 2 , R 3 , R 4 and R 5 (Hereinafter referred to as “R 1Each of the radicals (also referred to as "R, etc.") is independently hydrogen or a substituent. The substituent may be any 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 Both are never >C(-R)2, R in the >NR and >C(-R)2 are each independently hydrogen or a substituent selected from the substituent group Z, and may be further substituted with an aryl, heteroaryl, alkyl or cycloalkyl (these are the second substituents), and R in the >NR and >C(-R)2 are each independently 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 etc." are each independently =C(-R)- or =N- (pyridine nitrogen), and at least one is =N- (pyridine 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 6Adjacent groups among R in =C(-R)- as the formula may be bonded to each other to form an aryl ring or a heteroaryl ring together with at least one of the 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 in the compound and structure represented by formula (EH-1b) may be replaced with cyano, halogen or deuterium.

[0430] In formula (EH-1b), R 1 , R 2 , R 3 , R 4 and R 5 are all hydrogen or R 3 and R 4 are both hydrogen, and R 1 , R 2 and R 5It is preferable that at least one selected from the group consisting of is a substituent other than hydrogen, and the others are hydrogen. As the substituent, an aryl which may be substituted with an alkyl, an alkyl, or a heteroaryl, a heteroaryl which may be substituted with an alkyl or an aryl, or a diarylamino which may be substituted with an alkyl or an aryl is preferable. In this case, the alkyl is preferably an alkyl having 1 to 6 carbon atoms (methyl, t-butyl, etc.), the aryl is preferably phenyl or biphenyl, and the heteroaryl is preferably triazinyl, carbazolyl (2-carbazolyl, 3-carbazolyl, 9-carbazolyl, etc.), pyrimidinyl, pyridinyl, dibenzofuranyl, or dibenzothienyl. Specific examples include phenyl, biphenyl, diphenyltriazinyl, carbazolyltriazinyl, monophenylpyrimidinyl, diphenylpyrimidinyl, carbazolyltriazinyl, pyridinyl, dibenzofuranyl, and dibenzothienyl.

[0431] Y 1 etc. are each independently =C(-R)- or =N-, and at least one is =N-. 1 ~Y 6 Any of Y may be =N-. 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 ~Y 5 =N-(ring b and ring c are pyrimidine rings), Y 1 , Y 3 , Y 4 and Y 6 =N- (ring a is a pyrimidine ring, rings b and c are pyridine rings), Y 1 , Y 2 , Y 5 and Y 6=N- (ring a is a pyrimidine ring, rings b and c are pyridine rings), Y 1 ~Y 6 =N-(ring a, ring b and ring c are pyrimidine rings), Y 2 or Y 5 is =N-(ring b or ring c is a pyridine ring).

[0432] 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 one of the following formulas is preferred. [ka]

[0433] 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 has. Specific examples of the polycyclic aromatic compound represented by formula (EH-1b) are shown below.

[0434] [ka]

[0435] [ka]

[0436] [ka]

[0437] [ka]

[0438] [ka]

[0439] [ka]

[0440] 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-1-94 to EH-1-99, EH-1-100, EH-1-101, EH-1-104, EH-1-115, EH-1-117, EH-1-120, EH-1-122, EH-1-123, and EH-1-127 to EH-1-130 are preferred.

[0441] [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. Regarding 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.

[0442] The hole transporting host material and the electron transporting host material may be a combination that forms an association called an exciplex. It is generally known that an exciplex is easily formed between a material having a relatively deep LUMO level and a material having a shallow HOMO level. The interaction between the hole transporting host material and the electron transporting host material, specifically, whether or not 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 those for forming the light-emitting layer, measuring the emission spectrum (fluorescence spectrum, phosphorescence spectrum), and comparing the obtained emission spectrum with the emission spectrum shown by each of the hole transporting host material and the electron transporting host material alone. It can be determined by the spectrum of the mixed film containing the hole transporting host material and the electron transporting host material showing 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, it is sufficient to use the difference in the peak wavelength of the spectrum as an index of 10 nm or more.

[0443] 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. T1 In order to satisfy the physical property values, the hole transporting host material is preferably a compound having carbazole, dibenzofuran, dibenzothiophene, triarylamine, indolocarbazole and benzoxazinophenoxazine as a partial structure, more preferably a compound having carbazole, dibenzofuran and 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 and dibenzoxasiline as a partial structure, more preferably a compound having triazine, phosphine oxide, benzofuropyridine and dibenzoxasiline as a partial structure, and even more preferably a compound having triazine.

[0444] 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 It is preferable that the copolymer 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.

[0445] 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. T1In order to satisfy the physical property values, the hole transporting host material is preferably a compound having carbazole, triarylamine, indolocarbazole and benzoxazinophenoxazine as a partial structure, more preferably a compound having triarylamine, indolocarbazole and 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 and benzofuropyridine as a partial structure, more preferably a compound having triazine, phosphine oxide, benzofuropyridine and dibenzoxasiline as a partial structure, and even more preferably a compound having phosphine oxide and triazine.

[0446] 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, HH-1-24, and HH-1-115, 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, and EH-1-5. It is preferable that the copolymer is selected from the group consisting of EH-1-1 to EH-1-57, EH-1-59, EH-1-66, EH-1-68, EH-1-90, EH-1-94, EH-1-99, EH-1-100, EH-1-101, EH-1-104, EH-1-117, EH-1-120, EH-1-122, EH-1-123, and 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-1-94, compound HH-1-12 and compound EH-1-117, compound HH-1-1 and compound EH-1-130, compound HH-1-33 and compound EH-1-117, compound HH-1-48 and compound EH-1-117 or compound HH-1-49 and compound EH-1-117, and compound HH-1-115 and compound EH-1-99.

[0447] For other specific combinations of hole-transporting host materials and electron-transporting host materials, see Organic Electronics 66(2019)227-24, Advanced.Functional Materials 25(2015)361-366., Advanced Materials 26(2014)4730-4734., ACS Applied Materials and Interfaces 8(2016)32984-32991., ACS Applied Materials and Interfaces 2016,8,9806-9810, ACS Applied Materials and Interfaces 2016,8,32984-32991, Journal of Materials Chemistry C,2018,6,8784-8792, Angewante Chemie International Edition.2018,57,12380-12384, Advanced Functional Materials,24,2014,3970,Advanced Reference can be made to descriptions such as Materials, 26, 2014, 5684, Synthetic Metals, 201, 2015, 49, and Nature Photonics, 16, 212-218 (2022).

[0448] <Assisting dopant (thermally activated delayed fluorescent material or phosphorescent material)> The light-emitting layer preferably contains an assisting dopant in addition to the emitting dopant and the host material. The assisting dopant is preferably a thermally activated delayed fluorescent material or a phosphorescent material. As described above, the polycyclic aromatic compound containing the structural unit represented by formula (1) has reduced interaction with adjacent molecules and can be preferably used as an emitting dopant for a TAF element or a PSF element.

[0449] In this embodiment, a known host compound can be used, for example a compound having at least one of a carbazole ring and a furan ring, and among them, it is preferable to use a compound in which at least one of furanyl and carbazolyl is bonded to at least one of arylene and heteroarylene. Specific examples include compounds represented by any of formulas (H1), (H2), and (H3), particularly mCP and mCBP. In addition, a TADF-active compound may be used as the host compound. In this embodiment, it is also preferable to use a combination of a hole-transporting host material and an electron-transporting host material as the host.

[0450] The lowest excited triplet energy level E(1,T,Sh) obtained from the shoulder on the short-wavelength side of the peak of the phosphorescence spectrum of the host compound is preferably higher than the lowest excited triplet energy levels E(2,T,Sh) and E(3,T,Sh) of the emitting dopant or assisting dopant having the highest lowest excited triplet energy level in the emitting layer, from the viewpoint of promoting rather than inhibiting the generation of TADF in the emitting layer. Specifically, the lowest excited triplet energy level E(1,T,Sh) of the host compound is preferably higher by 0.01 eV or more than E(2,T,Sh) and E(3,T,Sh), more preferably higher by 0.03 eV or more, and even more preferably higher by 0.1 eV or more.

[0451] [Thermal activated delayed phosphor] "Thermally activated delayed fluorescent material" refers to a compound that absorbs thermal energy, undergoes reverse intersystem crossing from the lowest excited triplet state to the lowest excited singlet state, and then radiatively deactivates from the lowest excited singlet state to emit delayed fluorescence. However, "thermally activated delayed fluorescent material" also includes compounds that undergo higher triplets in the process of excitation from the lowest excited triplet state to the lowest excited singlet state. For example, see 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 a paper by Sato et al. of Kyoto University (Scientific Reports, 7: 4820, DOI: 10.1038 / s41598-017-05007-7). Examples of such reviews include a conference presentation by Sato et al. (98th Spring Annual Meeting of the Chemical Society of Japan, Presentation No.: 2I4-15, Mechanism of Highly Efficient Emission in Organic Electroluminescence Using DABNA as an Emitting Molecule, Graduate School of Engineering, Kyoto University), a review by Bui et al. (DOI: 10.3762 / bjoc.14.18), a review by Duan et al. (DOI: 10.1063 / 1.5143501), a review by Ding et al. (DOI: 10.1088 / 1674-4926 / 42 / 5 / 050201), and a review by Xie et al. (DOI: 10.1002 / adom.202002204). In the present invention, when a sample containing the target compound is measured for its fluorescence lifetime at 300K, if a slow fluorescent component is observed, the target compound is determined to be a "thermally activated delayed fluorescent material". Here, the term "slow fluorescent component" refers to a component whose fluorescent lifetime is 0.1 μsec or longer. The fluorescent lifetime can be measured, for example, using a fluorescent lifetime measuring device (manufactured by Hamamatsu Photonics KK, C11367-01).

[0452] In the light-emitting layer further containing the "thermally activated delayed phosphor" as an assisting dopant, the polycyclic aromatic compound of the present invention can function as an emitting dopant. That is, the "thermally activated delayed phosphor" can function as an assisting dopant that assists the emission of the polycyclic aromatic compound of the present invention. In this specification, an organic electroluminescent device that uses a thermally activated delayed fluorescent material as an assisting dopant is sometimes referred to as a "TAF device" (TADF Assisting Fluorescence device). The "host compound" in a TAF element means a compound whose lowest 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 material as an assisting dopant and the emitting dopant.

[0453] 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) in the molecule using an electron-donating substituent called a donor and an electron-accepting substituent called an acceptor, thereby causing efficient reverse intersystem crossing.

[0454] In this specification, the term "electron-donating substituent" (donor) refers to a substituent or partial structure in which the HOMO 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 is localized in the thermally activated delayed fluorescent substance molecule.

[0455] In general, thermally activated delayed phosphors 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 S1T1 Since is small, very fast reverse intersystem crossing rates are obtained.

[0456] By using the polycyclic aromatic compound of the present invention as an emitting dopant and the thermally activated delayed phosphor (TADF material) as an assisting dopant, it is possible to provide an element that satisfies any one or all of high efficiency, high color purity, and long life. The thermally activated delayed phosphor may be a compound whose emission spectrum at least partially overlaps with the absorption spectrum of the polycyclic aromatic compound of the present invention. The polycyclic aromatic compound of the present invention and the thermally activated delayed phosphor may both be contained in the same layer, or may be contained in an adjacent layer or other adjacent layers.

[0457] 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 donor group (donor structure) and electron acceptor 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-dihydro-indenoacridine, and diphenyl-dihydrodibenzoazasiline.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.

[0458] 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.

[0459] [Phosphorescent materials (assisting dopants)] In the light-emitting layer, a phosphorescent material may be used as an assisting dopant. In this specification, an organic electroluminescent device using a phosphorescent material as an assisting dopant may be referred to as a phosphorescence-assisted element, a phosphorescence-sensitized fluorescent element, or a PSF element. Phosphorescent materials utilize the intramolecular spin-orbit interaction (heavy atom effect) of metal atoms to obtain light emission from an excited triplet state. As such phosphorescent materials, for example, luminescent metal complexes can be used. As luminescent metal complexes, for example, compounds represented by the following formula (B-1) and the following formula (B-2) can be used.

[0460] [ka]

[0461] 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 the 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 viewpoints of efficiency and life. The ligand (XY) in the formula (B-1) has at least one ligand selected from the group consisting of the following: The ligand (WXYZ) in the formula (B-2) has at least one ligand selected from the group consisting of the following as a part.

[0462] [ka]

[0463] During the ceremony, --- binds to the central metal M, Y is independently BR e , N.R. e , P.R. e , O, S, Se, C=O, S=O, SO2, CR e R f , SiR e R f , or GeR e R f and Each aromatic carbon CH in the ring may be independently replaced by 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 number of possible 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 combinations 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.

[0464] 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), 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.

[0465] Other examples of the compound represented by formula (B-1) include the following compounds: [ka]

[0466] [ka]

[0467] [ka]

[0468] 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, etc., 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, Nature Photonics volume 16, pages 212-218 (2022) The platinum complexes described may be used.

[0469] <Other dopant materials> The polycyclic aromatic compound containing the structural unit represented by formula (1) may be used in combination with other dopant materials. However, the content of the other dopant materials is preferably less than 100% by mass, more preferably 50% by mass or less, even more preferably 30% by mass or less, and particularly preferably 10% by mass or less, based on the total mass of the polycyclic aromatic compound containing the structural unit represented by formula (1) in one light-emitting layer. Known compounds can be used as the other dopant materials, and they can be selected from various materials depending on the desired emission color.Specific examples of such compounds include condensed 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 bisstyrylanthracene 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, oxobenzoanthracene 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.

[0470] As other dopant materials, it is also preferable to use polycyclic aromatic compounds containing boron as described in WO 2015 / 102118, WO 2020 / 162600, and paragraphs 0097 to 0269 of JP 2021-077890.

[0471] 2-1-6. Electron injection layer and electron transport layer in organic electroluminescent device 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 types of electron transport / injection materials, or by a mixture of an electron transport / injection material and a polymer binder.

[0472] The electron injection / transport layer is a layer that is responsible for injecting electrons from the cathode and transporting the electrons. It is desirable that the electron injection efficiency is high and that the injected electrons are efficiently transported. For this purpose, it is preferable that the material has a large electron affinity, a large electron mobility, and excellent stability, and impurities that become traps are unlikely to occur during manufacture and use. However, when considering the balance of transport of holes and electrons, if the material mainly plays a role of efficiently preventing holes from flowing from the anode to the cathode without recombining, even if the electron transport ability is not so high, it has the effect of improving the luminous efficiency equivalent to a material with a high electron transport ability. Therefore, the electron injection / transport layer in this embodiment may also include the function of a layer that can efficiently block the movement of holes.

[0473] 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 the electron injection layer and electron transport layer of organic EL elements.

[0474] Materials used in the electron transport layer or electron injection layer preferably contain at least one selected from compounds consisting of aromatic rings or heteroaromatic rings composed of one or more atoms selected from carbon, hydrogen, oxygen, sulfur, silicon, and phosphorus, pyrrole derivatives and their condensed ring derivatives, and metal complexes having electron-accepting nitrogen. Specific examples include condensed ring aromatic ring derivatives such as naphthalene and anthracene, styryl aromatic ring derivatives such as 4,4'-bis(diphenylethenyl)biphenyl, perinone derivatives, coumarin derivatives, naphthalimide derivatives, quinone derivatives such as anthraquinone and diphenoquinone, phosphine oxide derivatives, arylnitrile derivatives, and indole derivatives. Examples of metal complexes having 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 different materials.

[0475] 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, etc. Examples of the compound include benzene derivatives, benzoquinoline derivatives (e.g., 2,2'-bis(benzo[h]quinolin-2-yl)-9,9'-spirobifluorene), imidazopyridine derivatives, borane derivatives, benzimidazole derivatives (e.g., tris(N-phenylbenzimidazol-2-yl)benzene), benzoxazole derivatives, benzothiazole derivatives, quinoline derivatives, oligopyridine derivatives such as terpyridine, bipyridine derivatives, terpyridine derivatives (e.g., 1,3-bis(2,2':6',2"-terpyridin-4'-yl)benzene), naphthyridine derivatives (e.g., bis(1-naphthyl)-4-(1,8-naphthyridin-2-yl)phenylphosphine oxide), aldazine derivatives, carbazole derivatives, indole derivatives, phosphine oxide derivatives, and bisstyryl derivatives.

[0476] Further, a metal complex having an electron-accepting nitrogen 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.

[0477] The above-mentioned materials may be used alone or in combination with different materials.

[0478] 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 preferable.

[0479] 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. As the reducing substance, various substances can be used as long as they have a certain degree of reducing ability, and for example, at least one selected from the group consisting of alkali metals, alkaline earth metals, rare earth metals, oxides of alkali metals, halides of alkali metals, oxides of alkaline earth metals, halides of alkaline earth metals, oxides of rare earth metals, halides of rare earth metals, organic complexes of alkali metals, organic complexes of alkaline earth metals, and organic complexes of rare earth metals can be suitably used.

[0480] Preferred reducing substances include alkali metals such as Na (work function 2.36 eV), K (2.28 eV), Rb (2.16 eV) or Cs (1.95 eV) and alkaline earth metals such as Ca (2.9 eV), Sr (2.0 to 2.5 eV) or Ba (2.52 eV), and substances with a work function of 2.9 eV or less are particularly preferred. Among these, more preferred reducing substances are alkali metals such as K, Rb or Cs, more preferably Rb or Cs, and most preferably Cs. These alkali metals have particularly high reducing ability, and by adding a relatively small amount to the material forming the electron transport layer or electron injection layer, the luminance of the organic EL element can be improved and the life can be extended. 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, for example, a combination of Cs and Na, Cs and K, Cs and Rb, or a combination of Cs, Na and K. By containing Cs, the reducing ability can be efficiently exhibited, and by adding it to a material forming an electron transport layer or an electron injection layer, the luminance of the organic EL element can be improved and the life span can be extended.

[0481] 2-1-7. Cathode in organic electroluminescent device 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 .

[0482] The material for forming the cathode 108 is not particularly limited as long as it is a substance that can efficiently inject electrons into the organic layer, but the same material as the material for forming the anode 102 can be used. Among them, metals such as tin, indium, calcium, aluminum, silver, copper, nickel, chromium, gold, platinum, iron, zinc, lithium, sodium, potassium, cesium, and magnesium, or alloys thereof (magnesium-silver alloy, magnesium-indium alloy, aluminum-lithium alloy such as lithium fluoride / aluminum, etc.), etc. are preferable. In order to increase the electron injection efficiency and improve the 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 the air. To improve this point, for example, a method is known in which a trace amount of lithium, cesium, or magnesium is doped into the organic layer to use a highly stable electrode. As other dopants, inorganic salts such as lithium fluoride, cesium fluoride, lithium oxide, and cesium oxide can also be used. However, they are not limited to these.

[0483] 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 substances such as silica, titania, and silicon nitride, polyvinyl alcohol, vinyl chloride, hydrocarbon polymer compounds, etc. The method of producing these electrodes is also not particularly limited as long as it can provide electrical continuity, and may be resistance heating, electron beam deposition, sputtering, ion plating, coating, or the like.

[0484] 2-1-8. Method for producing organic electroluminescent device Each layer constituting an organic EL element can be formed by forming the material to be formed into a thin film by a method such as vapor deposition, resistance heating vapor deposition, electron beam vapor deposition, sputtering, molecular lamination, printing, spin coating or casting, coating, etc. The thickness of each layer thus formed is not particularly limited and can be set appropriately according to the properties of the material, but is usually in the range of 2 nm to 5000 nm. The thickness of the film can usually be measured with a quartz crystal oscillation type film thickness measuring device, etc. When forming a thin film by vapor deposition, the vapor deposition conditions vary depending on the type of material, the desired crystal structure and association structure of the film, etc. The vapor deposition conditions are generally a boat heating temperature of +50 to +400°C, a vacuum degree of 10, and a vacuum of 10. -6 ~10 -3 It is preferable to appropriately set the pressure, pressure Pa, deposition rate 0.01 to 50 nm / sec, substrate temperature -150 to +300°C, and film thickness 2 nm to 5 µm.

[0485] 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 AC current applied may be any waveform.

[0486] Next, as an example of a method for producing an organic EL element, a method for producing an organic EL element consisting of an anode, a hole injection layer, a hole transport layer, an emitting layer consisting of a host material and a dopant material, an electron transport layer, an electron injection layer, and a cathode will be described.

[0487] <Vapor deposition method> A thin film of an anode material is formed on a suitable substrate by vapor deposition or the like to prepare an anode, and then a thin film of a hole injection layer and a hole transport layer is formed on the anode. A host material and a dopant material are co-deposited on the anode to form a thin film as a light-emitting layer, an electron transport layer and an electron injection layer are formed on the light-emitting layer, and a thin film of a cathode material is further formed by vapor deposition or the like to prepare a cathode, thereby obtaining a desired organic EL device. Note that in the preparation of the above-mentioned organic EL device, the preparation order can also be reversed, and the layers can be prepared in the order of cathode, electron injection layer, electron transport layer, light-emitting layer, hole transport layer, hole injection layer, and anode.

[0488] <Wet film formation method> The wet film formation method is carried out by preparing a low molecular weight compound capable of forming each organic layer of an organic EL element as a liquid composition for forming an organic layer, and using this. If there is no suitable organic solvent for dissolving this low molecular weight compound, the composition for forming an organic layer may be prepared from a polymer compound polymerized together with other monomers having a solubility function as a reactive compound obtained by substituting a reactive substituent on the low molecular weight compound or a main chain polymer.

[0489] In the wet film formation method, a coating film is generally formed through a coating step of coating a substrate with a composition for forming an organic layer and a drying step of removing the solvent from the coated composition for forming an organic layer. When the polymer compound has a crosslinkable substituent (also called a crosslinkable polymer compound), the polymer is further crosslinked by the drying step to form a crosslinked polymer. Depending on the difference in the coating step, a method using a spin coater is called a spin coat method, a method using a slit coater is called a slit coat method, a method using a plate is called a gravure, offset, reverse offset, or flexographic printing method, a method using an inkjet printer is called an inkjet method, and a method spraying in a mist form is called a spray method. The drying step includes air drying, heating, drying under reduced pressure, and the like. The drying step may be performed only once, or may be performed multiple times using different methods or conditions. In addition, different methods may be used in combination, such as baking under reduced pressure.

[0490] The wet film formation method is a film formation method using a solution, for example, some printing methods (inkjet methods), spin coating methods or casting methods, coating methods, etc. Unlike the vacuum deposition method, the wet film formation method does not require the use of expensive vacuum deposition equipment, and can form a film under atmospheric pressure. In addition, the wet film formation method allows for large area and continuous production, which leads to reduced manufacturing costs.

[0491] On the other hand, compared to the vacuum deposition method, wet film formation can be difficult to laminate. When producing laminated films using the wet film formation method, it is necessary to prevent the dissolution of the lower layer by the composition of the upper layer, and compositions with controlled solubility, crosslinking of the lower layer, and orthogonal solvents (solvents that do not dissolve in each other) are used. However, even with these technologies, it can be difficult to use the wet film formation method to apply all films.

[0492] Therefore, a method is generally adopted in which only some layers are formed by a wet film formation method and the remaining layers are formed by a vacuum deposition method when manufacturing an organic EL element.

[0493] For example, the procedure for producing an organic EL element by partially applying a wet film formation method will be described 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) Formation of 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 deposition Through this procedure, an organic EL element consisting of an anode, a hole injection layer, a hole transport layer, an 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 a layer-forming composition containing the material for the electron transport layer and the material for the electron injection layer, respectively. In this case, it is preferable to use a means for preventing dissolution of the lower light-emitting layer, or a means for forming the film from the cathode side in the reverse order to the above procedure.

[0494] <Other film formation methods> The composition for forming an organic layer can be formed into a film by laser thermal imaging (LITI). LITI is a method in which a compound attached to a substrate is heated and evaporated by a laser, and the composition for forming an organic layer can be used as the material applied to the substrate.

[0495] <Optional process> Before and after each film-forming step, appropriate treatment steps, cleaning steps, and drying steps may be appropriately inserted. 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.

[0496] Photolithography techniques can be used to fabricate the banks. Positive resist materials and negative resist materials can be used as bank materials that can be used in photolithography. In addition, patternable printing methods such as inkjet printing, gravure offset printing, reverse offset printing, and screen printing can also be used. In this case, permanent resist materials can also be used.

[0497] <Composition for forming organic layer used in wet film formation method> The composition for forming an organic layer 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 the low molecular weight compound, in an organic solvent. For example, the composition for forming an emitting layer contains at least one polycyclic aromatic compound (or a polymer compound thereof) as a first component, which is a dopant material, 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 of the emitting layer obtained from the composition, and the second component functions as a host component of the emitting layer. The third component functions as a solvent that dissolves the first and second components in the composition, and gives a smooth and uniform surface shape due to the controlled evaporation rate of the third component itself during application.

[0498] <Organic solvent> 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 the film forming properties, the presence or absence of defects in the coating film, the surface roughness, and the smoothness. In addition, during film formation using the inkjet method, it is possible to control the meniscus stability at the pinhole of the inkjet head, and control and improve the 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, light emitting properties, efficiency, and life of an organic EL element having an organic layer obtained from the organic layer forming composition.

[0499] After the film is formed, 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 the coating film-forming property, it is preferable to perform the heating at a temperature of at least one of the solutes at a glass transition temperature (Tg) +30°C or lower. From the viewpoint of reducing the residual solvent, it is preferable to heat at at least one of the solutes at a glass transition temperature (Tg) -30°C or higher. Even if the heating temperature is lower than the boiling point of the organic solvent, the organic solvent is sufficiently removed because the film is thin. Also, drying may be performed multiple times at different temperatures, and multiple drying methods may be used in combination.

[0500] (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.

[0501] <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.

[0502] <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 good solubility, storage stability, and film-formability of each component in the composition for forming an organic layer, as well as good film quality of a coating film obtained from the composition for forming an organic layer, good ejection properties when an inkjet method is used, and good electrical characteristics, light-emitting characteristics, efficiency, and life of an organic EL element having an organic layer produced using the composition.

[0503] The composition for forming an organic layer can be produced by appropriately selecting the above-mentioned components and subjecting them to stirring, mixing, heating, cooling, dissolving, dispersing, etc., by a known method. After preparation, filtration, degassing (also called degassing), ion exchange treatment, and inert gas replacement / filling treatment, etc. may be appropriately selected.

[0504] 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.

[0505] Examples of the display device 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, JP-A-2004-281086, etc.). Examples of the display method include matrix and segment methods. Note that matrix display and segment display may coexist in the same panel.

[0506] In a matrix, pixels for display 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, square pixels with sides of 300 μm or less are usually used to display images and characters on computers, monitors, and televisions, and pixels with sides of mm order are used for large displays such as display panels. For monochrome display, pixels of the same color are arranged, but for color display, red, green, and blue pixels are displayed side by side. In this case, there are typically delta type and stripe type. The driving method for this matrix can be either line sequential driving method or active matrix. Line sequential driving has the advantage of being simpler in structure, but when considering the operating characteristics, active matrix may be superior, so it is necessary to use it according to the application.

[0507] In the segment type, a pattern is formed to display predetermined information, and a predetermined area is illuminated. Examples include time and temperature displays in digital clocks and thermometers, operating status displays in audio equipment and induction cookers, and panel displays in automobiles.

[0508] Examples of the lighting device include lighting devices for indoor lighting, backlights for liquid crystal display devices, etc. (see, for example, JP 2003-257621 A, JP 2003-277741 A, JP 2004-119211 A, etc.). Backlights are mainly used for the purpose of improving 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 liquid crystal display devices, particularly backlights for personal computers, where thinning is an issue, it is difficult to make them thin because conventional methods are made of fluorescent lamps and light guide plates, so the backlight using the light-emitting element according to this embodiment is characterized by its thinness and light weight.

[0509] 2-2. Other organic devices The polycyclic aromatic compound according to the present invention can be used for producing the above-mentioned organic electroluminescent device, as well as an organic field effect transistor or an organic thin-film solar cell.

[0510] An organic field-effect transistor is a transistor that controls current by an electric field generated by voltage input, and has a gate electrode in addition to a source electrode and a drain electrode. When a voltage is applied to the gate electrode, an electric field is generated, and the flow of electrons (or holes) flowing between the source electrode and the drain electrode can be arbitrarily blocked to control the current. Field-effect transistors are easier to miniaturize than simple transistors (bipolar transistors), and are often used as elements that make up integrated circuits.

[0511] The structure of an organic field effect transistor is usually such that a source electrode and a drain electrode are provided in contact with an organic semiconductor active layer formed using the polycyclic aromatic compound according to the present invention, and a gate electrode is provided sandwiching an insulating layer (dielectric layer) in contact with the organic semiconductor active layer. Examples of the element structure include the following structure. (1) Substrate / gate electrode / insulating layer / source and drain electrodes / organic semiconductor active layer (2) Substrate / gate electrode / insulating layer / organic semiconductor active layer / source electrode and drain electrode (3) Substrate / organic semiconductor active layer / source electrode / drain electrode / insulator layer / gate electrode (4) Substrate / source electrode / drain electrode / organic semiconductor active layer / insulator layer / gate electrode The organic field effect transistor thus configured can be used as a pixel driving switching element for an active matrix driving type liquid crystal display or an organic electroluminescence display.

[0512] The organic thin-film solar cell has a structure in which an anode such as ITO, a hole transport layer, a photoelectric conversion layer, an electron transport layer, and a cathode are laminated on a transparent substrate such as glass. The photoelectric conversion layer has a p-type semiconductor layer on the anode side and an n-type semiconductor layer on the cathode side. The polycyclic aromatic compound according to the present invention can be used as a material for a hole transport layer, a p-type semiconductor layer, an n-type semiconductor layer, and an electron transport layer depending on its physical properties. The polycyclic aromatic compound according to the present invention can function as a hole transport material or an electron transport material in an organic thin-film solar cell. In addition to the above, the organic thin-film solar cell may appropriately include a hole blocking layer, an electron blocking layer, an electron injection layer, a hole injection layer, a smoothing layer, and the like. The organic thin-film solar cell can be used by appropriately selecting and combining known materials used in organic thin-film solar cells.

[0513] 3. Wavelength conversion materials The polycyclic aromatic compound of the present invention can be used as a wavelength conversion material. Currently, the application of multi-color technology using a color conversion method to liquid crystal displays, organic EL displays, lighting, and the like is being actively studied. Color conversion refers to converting the light emitted from a light emitter to light with a longer wavelength, for example, converting ultraviolet light or blue light to green light or red light emission. By forming this wavelength conversion material having color conversion function into a film and combining it with, for example, a blue light source, it becomes possible to extract the three primary colors of blue, green, and red from the blue light source, that is, to extract white light. By combining such a white light source, which is a combination of a blue light source and a wavelength conversion film having a color conversion function, with a liquid crystal driving part and a color filter as a light source unit, it becomes possible to manufacture a full-color display. In addition, if there is no liquid crystal driving part, it can be used as a white light source as it is, and can be applied as a white light source such as LED lighting. In addition, by using a blue organic EL element as a light source in combination with a wavelength conversion film that converts blue light into green light and red light, it becomes possible to manufacture a full-color organic EL display without using a metal mask. Furthermore, by using blue microLEDs as a light source in combination with a wavelength conversion film that converts blue light into green and red light, it is possible to create low-cost full-color microLED displays.

[0514] The polycyclic aromatic compound of the present invention can be used as this wavelength converting material. By using a wavelength converting material containing the polycyclic aromatic compound of the present invention, light from a light source or a light emitting element that generates ultraviolet light or shorter wavelength blue light can be converted into blue light or green light with high color purity suitable for use in a display device (a display device using an organic EL element or a liquid crystal display device). The converted color can be adjusted by appropriately selecting the substituent of the polycyclic aromatic compound of the present invention, the binder resin used in the wavelength converting composition described below, and the like. The wavelength converting material can be prepared as a wavelength converting composition containing the polycyclic aromatic compound of the present invention. In addition, a wavelength converting film may be formed using this wavelength converting composition.

[0515] The wavelength conversion composition may contain a binder resin, other additives, and a solvent in addition to the polycyclic aromatic compound of the present invention. As the binder resin, for example, those described in paragraphs 0173 to 0176 of WO 2016 / 190283 can be used. As the other additives, the compounds described in paragraphs 0177 to 0181 of WO 2016 / 190283 can be used. As the solvent, the description of the solvent contained in the composition for forming the light-emitting layer above can be referred to.

[0516] The wavelength conversion film includes a wavelength converting layer formed by curing the wavelength converting composition. Known film forming methods can be referred to as a method for producing a wavelength converting layer from a wavelength converting composition. The wavelength conversion film may consist only of a wavelength converting layer formed from a composition containing the polycyclic aromatic compound of the present invention, or may include other wavelength converting layers (e.g., a wavelength converting layer that converts blue light into green light or red light, or a wavelength converting layer that converts blue light or green light into red light). The wavelength conversion film may further include a substrate layer and a barrier layer for preventing deterioration of the color conversion layer due to oxygen, moisture, or heat. EXAMPLES

[0517] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these.

[0518] <<Synthesis Example>> Synthesis Example (1): Synthesis of Compound (1-1) [ka]

[0519] A 1.6M tert-butyllithium pentane solution (1.6ml) was added to a flask containing compound (S-1-1) (1.5g) and tert-butylbenzene (7.0ml) under a nitrogen atmosphere at -30°C. After the dropwise addition, the temperature was raised to 60°C and stirred for 2 hours, and then 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 (0.63g) was added, the mixture was heated to room temperature and stirred for 0.5 hours. Then, the mixture was cooled again to 0°C, N,N-diisopropylethylamine (0.43ml) was added, and the mixture was stirred at room temperature until the heat generation subsided, and then the mixture was heated to 120°C and stirred for 3 hours. The reaction solution was cooled to room temperature, and an aqueous sodium acetate solution cooled in an ice bath was added, followed by heptane, and the mixture was separated. Next, the residue was purified using a silica gel short-path column (eluent: toluene), and the solvent was distilled off under reduced pressure. The resulting solid was dissolved in toluene and reprecipitated by adding heptane to obtain compound (1-1) (0.32 g).

[0520] Compounds (1-2) to (1-20) and compounds (Ref-1-1) to (Ref-1-6) were synthesized according to the method of Synthesis Example (1). Compounds (Ref-1-1) to (Ref-1-6) are described in Science Advances. 8, eabq1641 (2022), Korean Patent Publication No. 10-2022-0069866, International Publication No. 2017 / 188111, Korean Patent Publication No. 10-2020-0011383, and U.S. Patent Application Publication No. 2021 / 0143331.

[0521] [ka]

[0522] The production of the target substance was confirmed by MALDI-TOF-MS (matrix-assisted laser desorption / ionization time-of-flight mass spectrometry).

[0523] The purity reduction was measured using HPLC from the peak of the target product before and after sublimation purification, and a purity reduction of 0.5% or more was recorded as "yes," and any other reduction was recorded as "no." For each compound, HPLC was performed under conditions that enabled separation of the target compound from other peaks. A column packed with silica gel carrying an 18-carbon alkyl group was used, with methanol as the solvent. The column oven temperature was set at 40 °C, the flow rate was 1.0 mL / min, and the detection wavelength was 254 nm.

[0524]

Table 1

[0525] <<Production and evaluation of evaporated organic EL devices>> Using each of the synthesized compounds of the present invention and comparative compounds, each of the organic EL elements of TTF, TADF, TAF, and PSF was manufactured. <TTF structure: Examples 1-1-1 to 1-1-20 and Comparative Examples 1-1-1 to 1-1-6> ITO (120 nm) / HI (40 nm) / HAT-CN (5 nm) / HT-1 (45 nm) / HT-2 (10 nm) / BH: each compound described in Table 2 (97:3) (25 nm) / ET-1 (5 nm) / ET-2:Liq (1:1) (25 nm) / LiF (1 nm) / Al (100 nm) The chemical structures of the compounds used in the manufacture of the above elements are shown below.

Chemical formula

[0526] A glass substrate (manufactured by Opto Science Co., Ltd.) with dimensions of 26 mm × 28 mm × 0.7 mm, on which ITO with a thickness of 180 nm formed by sputtering was polished to 120 nm, was used as the transparent support substrate. This transparent support substrate was fixed to the substrate holder of a commercially available vapor deposition apparatus (manufactured by Showa Vacuum Co., Ltd.), and molybdenum vapor deposition boats containing HI, HAT-CN, HT-1, HT-2, BH, each compound described in Table 2, ET-1, and ET-2, and aluminum nitride vapor deposition boats containing Liq, LiF, and aluminum were attached.

[0527] On the ITO film of the transparent support substrate, the following layers are sequentially formed. The vacuum chamber is evacuated to 5×10 -4 Pa, and first, HI is heated and vapor-deposited to a film thickness of 40 nm, then HAT-CN is heated and vapor-deposited to a film thickness of 5 nm, then HT-1 is heated and vapor-deposited to a film thickness of 45 nm, and then HT-2 is heated and vapor-deposited to a film thickness of 10 nm to form a hole layer composed of four layers. Next, BH and each compound described in Table 2 are simultaneously heated and vapor-deposited to a film thickness of 25 nm to form a light-emitting layer. The deposition rate was adjusted so that the mass ratio of BH to each compound described in Table 2 was approximately 97 to 3. Further, ET-1 is heated and vapor-deposited to a film thickness of 5 nm, and then ET-2 and Liq are simultaneously heated and vapor-deposited to a film thickness of 25 nm to form an electron layer composed of two layers. The deposition rate was adjusted so that the mass ratio of ET-2 to Liq was approximately 50 to 50. The deposition rate of each layer was 0.01 - 1 nm / second. Thereafter, LiF is heated and vapor-deposited at a deposition rate of 0.01 - 0.1 nm / second to a film thickness of 1 nm, and then aluminum is heated and vapor-deposited to a film thickness of 100 nm to form a cathode, and an organic EL element is obtained.

[0528] <TADF Structure: Examples 2-1-1 to 2-1-20 and Comparative Examples 2-1-1 to 2-1-6> ITO(50 nm) / HAT-CN(10 nm) / HT-1(60 nm) / SiCzCz(5 nm) / SiCzCz:SiTrzCz2: Each compound described in Table 2 (60:39:1)(35 nm) / mSiTrz(5 nm) / mSiTrz:Liq(1:1)(30 nm) / LiF(1 nm) / Al(100 nm) A glass substrate (manufactured by Opto Science Co., Ltd.) with dimensions of 26 mm × 28 mm × 0.7 mm, on which ITO with a thickness of 200 nm was formed by sputtering and polished to 50 nm, was used as the transparent support substrate. This transparent support substrate was fixed to the substrate holder of a commercially available vapor deposition apparatus (manufactured by Showa Vacuum Co., Ltd.), and molybdenum vapor deposition boats containing HAT-CN, HT-1, SiCzCz, SiTrzCz2, each compound described in Table 2, mSiTrz, and Liq, and tungsten vapor deposition boats containing LiF and aluminum were attached.

[0529] The following layers were sequentially formed on the ITO film of the transparent support substrate. The vacuum chamber was evacuated to 5×10 -4 Pa, and first, HAT-CN was heated and evaporated to a thickness of 10 nm to form a hole injection layer. Next, HT-1 was heated and evaporated to a thickness of 60 nm to form a hole transport layer 1, and further, SiCzCz was heated and evaporated to a thickness of 5 nm to form a hole transport layer 2. Next, SiCzCz, SiTrzCz2, and each compound listed in Table 2 were simultaneously heated and evaporated to a thickness of 35 nm to form a light-emitting layer. The deposition rate was adjusted so that the mass ratio of SiCzCz, SiTrzCz2, and each compound listed in Table 2 was approximately 60:39:1. Next, mSiTrz was heated and evaporated to a thickness of 5 nm to form an electron transport layer 1, and further, mSiTrz and Liq were heated and evaporated to a thickness of 30 nm to form an electron transport layer 2. The deposition rate was adjusted so that the mass ratio of SiTrz and Liq was approximately 1:1. The deposition rate of each layer was 0.01 - 1 nm / second. Thereafter, LiF was heated and evaporated at a deposition rate of 0.01 - 0.1 nm / second to a thickness of 1 nm, and then, aluminum was heated and evaporated to a thickness of 100 nm to form a cathode, obtaining an organic EL element. At this time, the deposition rate of aluminum was adjusted to be 1 - 10 nm / second. Note that SiCzCz in the light-emitting layer corresponds to a hole-transporting host material, and SiTrzCz2 corresponds to an electron-transporting host material.

[0530] <TAF Configuration: Examples 3-1-1 to 3-1-20, Comparative Examples 3-1-1 to 3-1-6> ITO(50nm) / HAT-CN(10nm) / HT-1(60nm) / SiCzCz(5nm) / SiCzCz:SiTrzCz2:TADF-1: Each compound listed in Table 2(60:26:13:1)(35nm) / mSiTrz(5nm) / mSiTrz:Liq(1:1)(30nm) / LiF(1nm) / Al(100nm) Except for the light-emitting layer, it was fabricated in the same manner as the TADF structure. In the light-emitting layer, SiCzCz, SiTrzCz2, (TADF-1), and each compound described in Table 2 were simultaneously heated and vapor-deposited to a film thickness of 35 nm. The deposition rate was adjusted so that the mass ratio of SiCzCz, SiTrzCz2, (TADF-1), and each compound described in Table 2 was approximately 60:26:13:1.

[0531] <PSF structure: Examples 4-1-1 to 4-1-20, Comparative Examples 4-1-1 to 4-1-6> ITO(50 nm) / HAT-CN(10 nm) / HT-1(60 nm) / SiCzCz(5 nm) / SiCzCz:SiTrzCz2:PtON-TBBI: each compound described in Table 2 (60:26:13:1)(35 nm) / mSiTrz(5 nm) / mSiTrz:Liq(1:1)(30 nm) / LiF(1 nm) / Al(100 nm) (TADF-1) of the above TAF structure was replaced with PtON-TBBI, and the device was fabricated in the same manner.

[0532] The chemical structures of the compounds used in the manufacture of the above devices are shown below.

[0533] [Chemical formula]

[0534] [Evaluation] Evaluation items include driving voltage (V), emission wavelength (nm), CIE chromaticity (x, y), external quantum efficiency (%), maximum wavelength (nm) and full width at half maximum (nm) of the emission spectrum, etc. These evaluation items can use the values during emission, for example, at 1000 cd / m 2 The values during emission can be used.

[0535] The quantum efficiency of a light-emitting element includes internal quantum efficiency and external quantum efficiency, and the internal quantum efficiency indicates the ratio of external energy injected as electrons (or holes) into the light-emitting layer of the light-emitting element that 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.

[0536] The spectral radiance (emission spectrum) and external quantum efficiency were measured as follows. The device luminance was set to 1000 cd / m using an Advantest voltage / current generator R6144. 2 The device emits light by applying a voltage that is equal to the wavelength of the light emitted by the device. The spectral radiance of the visible light region is measured from a direction perpendicular to the light-emitting surface using a TOPCON SR-3AR spectroradiometer. Assuming that the light-emitting surface is a perfect diffusing surface, the measured spectral radiance value of each wavelength component is divided by the wavelength energy and multiplied by π to obtain the number of photons at each wavelength. The number of photons is then integrated over the entire wavelength range observed to obtain the total number of photons emitted from the device. The applied current value is divided by the elementary charge to obtain the number of carriers injected into the device, and the total number of photons emitted from the device is divided by the number of carriers injected into the device to obtain the external quantum efficiency. The half-width of the emission spectrum is calculated as the width between the wavelengths above and below where the intensity is 50% of the maximum emission wavelength.

[0537] A DC voltage of 1000 cd / m was applied to the ITO electrode as the anode and the LiF / aluminum electrode as the cathode. 2 The characteristics of the light emission were measured. In addition, the time (lifetime) during which the TTF structure element maintained 95% or more of the initial brightness, and the time (lifetime) during which the TADF structure, TAF structure, and PSF structure elements maintained 50% or more of the initial brightness were measured. The emission peak of the elements was in the range of 450 to 470 nm in all cases. The results are shown in Table 2.

[0538] [Table 2] TIFF2025031542000186.tif239170TIFF2025031542000187.tif237170TIFF2025031542000188.tif60170

[0539] The results show that the devices of the examples have higher efficiency and longer life than the devices of the comparative examples that utilize compounds having skeletons corresponding to those of the examples.

[0540] <<Fabrication and evaluation of solution-type organic EL devices>> Next, an organic EL device obtained by forming an organic layer by coating will be described.

[0541] <Synthesis of polymer host compound: SPH-101> SPH-101 was synthesized according to the method described in International Publication No. 2015 / 008851. A copolymer was obtained in which M2 or M3 was bonded next to M1, and it is estimated from the feed ratio that each unit is 50:26:24 (molar ratio). In the following structural formula, Bpin is pinacolatoboryl, and * is the linking point of each unit. [ka]

[0542] <Synthesis of polymer hole transport compound: XLP-101> XLP-101 was synthesized according to the method described in JP 2018-61028 A. A copolymer in which M5 or M6 is bonded next to M4 was obtained, and it is estimated that each unit is 40:10:50 (molar ratio) based on the feed ratio. Bpin is pinacolatoboryl, and * is the linking point of each unit. [ka]

[0543] <Preparation of organic EL elements of Examples 5-1 to 5-3> Table 3 shows the material composition of each layer in the organic EL element.

Table 3

[0544] The structure of "ET1" in Table 3 is shown below.

Chemical formula

[0545] <Preparation of the composition (1) for forming a light-emitting layer> The composition (1) for forming a light-emitting layer is prepared by stirring the following components until a homogeneous solution is obtained. The prepared composition for forming a light-emitting layer is spin-coated on a glass substrate and dried by heating under reduced pressure to obtain a coating film without film defects and excellent in smoothness. Compound (A) 0.04 mass% SPH-101 1.96 mass% Xylene 69.00 mass% Decalin 29.00 mass%

[0546] Compound (A) is a polycyclic aromatic compound containing a structural unit represented by formula (1) (for example, compound (1-1)), a polymer compound obtained by polymerizing the polycyclic aromatic compound as a monomer (i.e., the monomer has a reactive substituent), or a polymer crosslinked body obtained by further crosslinking the polymer compound. The polymer compound for obtaining the polymer crosslinked body has a crosslinkable substituent.

[0547] <PEDOT:PSS solution> A commercially available PEDOT:PSS solution (Clevios(TM) P VP AI4083, an aqueous dispersion of PEDOT:PSS, manufactured by Heraeus Holdings) is used.

Chemical formula

[0548] <Preparation of the OTPD solution> OTPD (manufactured by Luminescence Technology Corp., LT-N159) and IK-2 (photo cationic polymerization initiator, manufactured by San-Apro Ltd.) are dissolved in toluene to prepare an OTPD solution with an OTPD concentration of 0.7% by mass and an IK-2 concentration of 0.007% by mass.

Chemical formula

[0549] <Preparation of XLP-101 solution> XLP-101 is dissolved in xylene at a concentration of 0.6% by mass to prepare a 0.6% by mass XLP-101 solution.

[0550] <Preparation of PCz solution> PCz (polyvinylcarbazole) is dissolved in dichlorobenzene to prepare a 0.7% by mass PCz solution.

Chemical formula

[0551] <Example 5-1> On a glass substrate with ITO vapor-deposited to a thickness of 150 nm, a PEDOT:PSS solution is spin-coated and baked on a hot plate at 200 °C for 1 hour to form a PEDOT:PSS film with a thickness of 40 nm (hole injection layer). Next, the OTPD solution is spin-coated and dried on a hot plate at 80 °C for 10 minutes, then exposed with an exposure intensity of 100 mJ / cm 2 and baked on a hot plate at 100 °C for 1 hour to form an OTPD film with a thickness of 30 nm that is insoluble in the solution (hole transport layer). Next, the composition for forming the light-emitting layer (1) is spin-coated and baked on a hot plate at 120 °C for 1 hour to form a light-emitting layer with a thickness of 20 nm.

[0552] The fabricated multilayer film is fixed to the substrate holder of a commercially available vapor deposition apparatus (manufactured by Showa Vacuum Co., Ltd.), and a molybdenum vapor deposition boat containing ET1, a molybdenum vapor deposition boat containing LiF, and a tungsten vapor deposition boat containing aluminum are attached. The vacuum chamber is evacuated to 5×10-4 After reducing the pressure to 1 Pa, ET1 is heated and evaporated to a thickness of 30 nm to form an electron transport layer. The evaporation rate for forming the electron transport layer is 1 nm / sec. Thereafter, LiF is heated and evaporated at an evaporation rate of 0.01 to 0.1 nm / sec to a thickness of 1 nm. Next, aluminum is heated and evaporated to a thickness of 100 nm to form a cathode. In this manner, an organic EL device is obtained.

[0553] <Example 5-2> An organic EL device is obtained in the same manner as in Example 5-1. The hole transport layer is formed by spin-coating an XLP-101 solution and baking it on a hot plate at 200° C. for 1 hour to form a film with a thickness of 30 nm.

[0554] <Example 5-3> An organic EL device is obtained in the same manner as in Example 5-1. The hole transport layer is formed by spin-coating a PCz solution and baking it on a hot plate at 120° C. for 1 hour to form a film with a thickness of 30 nm.

[0555] <Evaluation of Organic EL Devices of Examples 5-1 to 5-3> The coating type organic EL device obtained as described above is expected to have excellent driving voltage and external quantum efficiency, similar to the deposition type organic EL device.

[0556] <Preparation of organic EL elements of Examples 5-4 to 5-6> Table 4 shows the material composition of each layer in the organic EL element. [Table 4]

[0557] <Preparation of compositions (2) to (4) for forming light-emitting layer> A composition for forming a light-emitting layer (2) is prepared by stirring the following components until a homogeneous solution is obtained. Compound (A) 0.02% by mass mCBP 1.98 Mass% Toluene 98.00% by mass

[0558] The following components are stirred until a homogeneous solution is obtained, thereby preparing a composition (3) for forming a light-emitting layer. Compound (A) 0.02% by mass SPH-101 1.98 Mass% Xylene 98.00% by mass

[0559] A composition for forming a light-emitting layer (4) is prepared by stirring the following components until a homogeneous solution is obtained. Compound (A) 0.02% by mass DOBNA 1.98 Mass% Toluene 98.00% by mass

[0560] In Table 4, "mCBP" is 3,3'-bis(N-carbazolyl)-1,1'-biphenyl, "DOBNA" is 3,11-di-o-tolyl-5,9-dioxa-13b-boranaphtho[3,2,1-de]anthracene, and "TSPO1" is diphenyl[4-(triphenylsilyl)phenyl]phosphine oxide. The chemical structures are shown below. [ka]

[0561] <Example 5-4> A glass substrate on which an ITO film is formed to a thickness of 45 nm is spin-coated with an ND-3202 (Nissan Chemical Industries) solution, and then heated at 50°C for 3 minutes in an air atmosphere, and then heated at 230°C for 15 minutes to form a 50 nm thick ND-3202 film (hole injection layer). Next, an XLP-101 solution is spin-coated, and heated on a hot plate at 200°C for 30 minutes in a nitrogen gas atmosphere to form a 20 nm thick XLP-101 film (hole transport layer). Next, a composition for forming an emitting layer (2) is spin-coated, and heated at 130°C for 10 minutes in a nitrogen gas atmosphere to form a 20 nm thick emitting layer.

[0562] The prepared multilayer film is fixed to the substrate holder of a commercially available deposition device (Showa Vacuum Co., Ltd.), and a molybdenum deposition boat containing TSPO1, a molybdenum deposition boat containing LiF, and a tungsten deposition boat containing aluminum are installed. The vacuum chamber is heated to 5×10 -4 After reducing the pressure to 1 Pa, TSPO1 is heated and evaporated to a thickness of 30 nm to form an electron transport layer. The evaporation rate for forming the electron transport layer is 1 nm / sec. Thereafter, LiF is heated and evaporated at an evaporation rate of 0.01 to 0.1 nm / sec to a thickness of 1 nm. Next, aluminum is heated and evaporated to a thickness of 100 nm to form a cathode. In this manner, an organic EL device is obtained.

[0563] <Example 5-5 and Example 5-6> An organic EL element is obtained by using the composition for forming a light emitting layer (3) or (4) in the same manner as in Example 5-4.

[0564] <Evaluation of Organic EL Devices of Examples 5-4 to 5-6> The coating type organic EL device obtained as described above is expected to have excellent driving voltage and external quantum efficiency, similar to the deposition type organic EL device.

[0565] <Preparation of organic EL elements of Examples 5-7 to 5-9> Table 5 shows the material composition of each layer in the organic EL element. [Table 5]

[0566] <Preparation of compositions (5) to (7) for forming light-emitting layer> A composition for forming a light-emitting layer (5) is prepared by stirring the following components until a homogeneous solution is obtained. Compound (A) 0.02% by mass 2PXZ-TAZ 0.18 Mass% mCBP 1.80 Mass% Toluene 98.00% by mass

[0567] A composition for forming a light-emitting layer (6) is prepared by stirring the following components until a homogeneous solution is obtained. Compound (A) 0.02% by mass 2PXZ-TAZ 0.18 Mass% SPH-101 1.80 Mass% Xylene 98.00% by mass

[0568] A composition for forming a light-emitting layer (7) is prepared by stirring the following components until a homogeneous solution is obtained. Compound (A) 0.02% by mass 2PXZ-TAZ 0.18 Mass% DOBNA 1.80 Mass% Toluene 98.00% by mass

[0569] In Table 5, "2PXZ-TAZ" is 10,10'-((4-phenyl-4H-1,2,4-triazole-3,5-diyl)bis(4,1-phenylene))bis(10H-phenoxazine). The chemical structure is shown below. [ka]

[0570] <Examples 5-7> A glass substrate on which an ITO film is formed to a thickness of 45 nm is spin-coated with an ND-3202 (Nissan Chemical Industries) solution, and then heated at 50°C for 3 minutes in an air atmosphere, and then heated at 230°C for 15 minutes to form a 50 nm thick ND-3202 film (hole injection layer). Next, an XLP-101 solution is spin-coated, and heated on a hot plate at 200°C for 30 minutes in a nitrogen gas atmosphere to form a 20 nm thick XLP-101 film (hole transport layer). Next, a composition for forming an emitting layer (5) is spin-coated, and heated at 130°C for 10 minutes in a nitrogen gas atmosphere to form a 20 nm thick emitting layer.

[0571] The prepared multilayer film is fixed to the substrate holder of a commercially available deposition device (Showa Vacuum Co., Ltd.), and a molybdenum deposition boat containing TSPO1, a molybdenum deposition boat containing LiF, and a tungsten deposition boat containing aluminum are installed. The vacuum chamber is heated to 5×10 -4 After reducing the pressure to 1 Pa, TSPO1 is heated and evaporated to a thickness of 30 nm to form an electron transport layer. The evaporation rate for forming the electron transport layer is 1 nm / sec. Thereafter, LiF is heated and evaporated at an evaporation rate of 0.01 to 0.1 nm / sec to a thickness of 1 nm. Next, aluminum is heated and evaporated to a thickness of 100 nm to form a cathode. In this manner, an organic EL device is obtained.

[0572] <Examples 5-8 and 5-9> An organic EL device is obtained using the composition for forming a light-emitting layer (6) or (7) in the same manner as in Examples 5-7.

[0573] <Evaluation of Organic EL Devices of Examples 5-7 to 5-9> The coating type organic EL device obtained as described above is expected to have excellent driving voltage and external quantum efficiency, similar to the deposition type organic EL device. [Explanation of symbols]

[0574] 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 consisting of one or more structural units represented by formula (1); 【Chemistry 1】 In formula (1), ring A, ring B, and ring C each independently represent a substituted or unsubstituted aryl ring or a substituted or unsubstituted heteroaryl ring; However, at least one selected from the group consisting of ring A, ring B, and ring C is represented by at least the formula (E ABC or an aryl ring having a group represented by the formula (E ABC ) as a substituent, Each Ar is independently a group represented by formula (Ar), Formula (E ABC )middle, * indicates the position of attachment to the aryl or heteroaryl ring; ring P and ring Q each independently represent a substituted or unsubstituted aryl ring or a substituted or unsubstituted heteroaryl ring; Z X is -C(-R ZX )= or -N=, and R ZX is hydrogen or a substituent; Y 1 >N-R NY , >C(-R CY ) 2 , >O, >Si(-R IY ) 2 , > P-R PY , >P(=O)R POY , >S, >SO, >SO 2 or >Se, R NY , R CY , R IY , R PY , and R POY are each independently hydrogen, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted alkyl, or substituted or unsubstituted cycloalkyl; CY may be bonded to each other to form a ring, and two R IY may be bonded to each other to form a ring, In the formula (Ar), * indicates the bond position to nitrogen Ring D is a substituted or unsubstituted aryl ring or a substituted or unsubstituted heteroaryl ring; R D is a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted arylthio, a substituted or unsubstituted heteroarylthio, a substituted or unsubstituted aryloxy, a substituted or unsubstituted heteroaryloxy, a substituted alkyl, an unsubstituted alkyl having 4 to 24 carbon atoms, or a substituted or unsubstituted cycloalkyl, R D the aryl or heteroaryl ring in may be bonded to ring D via a single bond or a linking group; At least one selected from the group consisting of aryl rings and heteroaryl rings in the above structure may be fused with at least one cycloalkane, the cycloalkane may be substituted with at least one substituent, and at least one -CH 2 - may be replaced by -O-; In the above structure, at least one hydrogen may be replaced with deuterium, and at least one nitrogen may be replaced with nitrogen-15 ( 15 N), and at least one sulfur may be replaced by sulfur-33 ( 33 S), Sulfur-34 ( 34 S) or sulfur-36 ( 36 S), and at least one oxygen may be replaced by oxygen-17 ( 17 O) or oxygen-18 ( 18 O), and at least one carbon may be replaced by carbon-13 ( 13 C), and at least one boron may be replaced by boron-11 ( 11 B) may be substituted.

2. Formula (E ABC ) is represented by the formula (E ABC -1) The polycyclic aromatic compound according to claim 1; 【Chemistry 2】 Formula (E ABC -1) Middle, Y 1 , Z X is represented by the formula (E ABC ) in Y 1 , Z X are synonymous with Z E Each independently represents -C(-R ZE )= or -N=, and R ZE is hydrogen or a substituent.

3. The polycyclic aromatic compound according to claim 1, wherein each Ar is independently a group represented by formula (2Ar), a substituted or unsubstituted 4-dibenzothienyl, a substituted or unsubstituted 1-dibenzothienyl, a substituted or unsubstituted 4-dibenzofuranyl, or a substituted or unsubstituted 1-dibenzofuranyl; 【Chemistry 3】 In the formula (2Ar), R e are each independently hydrogen or unsubstituted alkyl; R d are each independently hydrogen, unsubstituted alkyl, unsubstituted cycloalkyl, or unsubstituted aryl; R dd is hydrogen or substituted or unsubstituted aryl.

4. The polycyclic aromatic compound according to claim 1, represented by the formula (1X1): 【Chemistry 4】 In formula (1X1), Ar has the same meaning as Ar in formula (1), R a is hydrogen or unsubstituted alkyl; R b is the formula (E ABC -1), a substituted or unsubstituted 9-carbazolyl, or a substituted or unsubstituted diarylamino, 【Chemistry 5】 Formula (1X1) and Formula (E ABC -1) In each formula, Y 1 , Z X is the formula (E ABC ) in Y 1 , Z X are synonymous with Z E Each independently represents -C(-R ZE )= or -N=, R ZE is hydrogen or a substituent.

5. R b Formula (E ABC 5. The polycyclic aromatic compound according to claim 4, wherein the group is represented by the formula (I).

6. The polycyclic aromatic compound according to claim 5, represented by any one of the following formulas: 【Chemistry 6】 In the formula, tBu is t-butyl.

7. R b The polycyclic aromatic compound according to claim 4, wherein is a substituted or unsubstituted 9-carbazolyl or a substituted or unsubstituted diarylamino.

8. The polycyclic aromatic compound according to claim 7, represented by any one of the following formulas: 【Chemistry 7】 【Chemistry 8】 【Chemistry 9】 In the formula, tBu is t-butyl and Ad is 1-adamantyl.

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, the organic layer containing the polycyclic aromatic compound according to any one of claims 1 to 8.

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

11. The organic electroluminescent device of claim 10 , wherein the light-emitting layer comprises at least one selected from the group consisting of an assisting dopant and a phosphorescent material.

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

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