Polycyclic aromatic compound

Abstract

To provide a compound useful as a material for an organic device such as an organic electroluminescent element.SOLUTION: Polycyclic aromatic compounds having a structure consisting of one or two or more structural unit (s) represented by the formula (1); (Ra1 to Ra3, Rb1 to Rb4, Rc1 to Rc4 are independently H or substituents; provided that at least one of Rc1 to Rc4 is a group represented by the formula (1-1); Y1 is B; and are independently> N-RNX; RNX is substituted / unsubstituted aryl; at least one of the aryl ring and the heteroaryl ring in the above structure may be fused with at least one cycloalkane, and H in the above structure may be replaced by D. X1 X2. ) SELECTED DRAWING: None

Description

[Technical Field]

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

[0002] Display devices using electroluminescent light-emitting elements have been extensively studied because of their potential for power saving and thinning, and organic electroluminescent devices made from organic materials have been actively investigated 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, 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 polymeric or low-molecular-weight compounds.

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

[0004] Among these, Patent Documents 1 and 2 disclose that boron-containing polycyclic aromatic compounds are useful as materials for organic electroluminescent devices and the like. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] International Publication No. 2015 / 102118 [Patent Document 2] International Publication No. 2020 / 251049 Summary of the Invention [Problem to be solved by the invention]

[0006] As mentioned above, various materials have been developed for use in organic EL devices. However, in order to increase the options for materials for organic EL devices, it is desirable to develop materials made of novel compounds. 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 conducted extensive research to solve the above-mentioned problems and succeeded in producing a novel polycyclic aromatic compound having superior light-emitting properties among polycyclic aromatic compounds having a structure similar to that of the compounds described in Patent Documents 1 and 2. They also discovered that an excellent organic EL device can be obtained by disposing a layer containing this polycyclic aromatic compound between a pair of electrodes, thereby completing the present invention. Specifically, the present invention provides the following polycyclic aromatic compounds, as well as materials for organic devices containing the following polycyclic aromatic compounds. Specifically, the present invention has the following configuration.

[0008] <1> A polycyclic aromatic compound having a structure consisting of one or more structural units represented by formula (1); [ka] In formula (1), R a1 ~R a3 , R b1 ~R b4 , R c1 ~R c4 are each independently hydrogen or a substituent, provided that R c1 ~R c4 at least one of which is a group represented by formula (1-1); Y 1is B, P, P═O, P═S, Al, Ga, As, Si—R, or Ge—R, and R of the Si—R and the Ge—R is a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted alkyl, or a substituted or unsubstituted cycloalkyl; X 1 and X 2 are independently >O, >NR NX ,>C(-R CX )2, >Si(-R IX )2, >S, or >Se, and R NX is hydrogen, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted alkyl, or substituted or unsubstituted cycloalkyl; R CX are each independently hydrogen, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted alkyl, or substituted or unsubstituted cycloalkyl; CX may be bonded to each other to form a ring, and R IX are each independently hydrogen, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted alkyl, or substituted or unsubstituted cycloalkyl; IX may be bonded to each other to form a ring, and R NX , R CX , and R IX are connected to R by a linking group or a single bond, respectively. a3 or R b1 may be bonded to at least one of the carbon atoms to which R a1 or R c4 may be bonded to at least one of the carbons to which is bonded; In formula (1-1), * indicates the bond position; R d1 ~R d7 are each independently hydrogen or a substituent; In the above structure, at least one selected from the group consisting of an aryl ring and a heteroaryl ring 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.

[0009] <2> X 1 and X 2 However, both are >NR NX That is, <1> The polycyclic aromatic compound according to any one of claims 1 to 4. <3> R NX are each independently substituted or unsubstituted phenyl, substituted or unsubstituted biphenylyl, substituted or unsubstituted terphenylyl, substituted or unsubstituted dibenzofuranyl, or substituted or unsubstituted carbazolyl; R NX wherein the aryl or heteroaryl ring is optionally fused with at least one cycloalkane; <1> or <2> The polycyclic aromatic compound according to any one of claims 1 to 4. <4> The Y 1 is B, <1> ~ <3> 1. The polycyclic aromatic compound according to any one of claims 1 to 9. <5> R a1 ~R a3are each independently hydrogen, substituted or unsubstituted aryl, substituted or unsubstituted alkyl, or substituted silyl; <1> ~ <4> 1. The polycyclic aromatic compound according to any one of claims 1 to 9. <6> R a1 and R a3 are all hydrogen, and R a2 is hydrogen, substituted or unsubstituted aryl, substituted or unsubstituted alkyl, or substituted silyl; <5> The polycyclic aromatic compound according to any one of claims 1 to 4.

[0010] <7> R b1 ~R b4 Among them, R b2 or R b3 is a substituent, and R b1 and R b4 are each independently hydrogen, or R b2 and R b3 are bonded to each other to form a partial structure represented by formula (B11) or formula (B12), and R b1 and R b4 are hydrogen, <1> ~ <6> the polycyclic aromatic compound according to any one of the preceding claims; [ka] In each of the formulas (B11) and (B12), Me is methyl, and * indicates the bonding position. <8> R b1 ~R b4 Among them, R b2 is a substituted or unsubstituted diarylamino; <1> ~ <7> 1. The polycyclic aromatic compound according to any one of claims 1 to 9. <9> R c2 and R c3 At least one of the groups is a group represented by formula (1-1). <1> ~ <8> 1. The polycyclic aromatic compound according to any one of claims 1 to 9. <10> In formula (1-1), R d1 ~R d7 are each independently hydrogen, substituted or unsubstituted aryl, or unsubstituted alkyl; <1> ~ <9> 1. The polycyclic aromatic compound according to any one of claims 1 to 9. <11> In formula (1-1), R d1 ~Rd3 , R d5 ~R d7 are all hydrogen, and R d4 is hydrogen, substituted or unsubstituted aryl, or unsubstituted alkyl; <10> The polycyclic aromatic compound according to any one of claims 1 to 4.

[0011] <12> Represented by one of the following formulas: <1> the polycyclic aromatic compound according to [ka]

[0012] [ka]

[0013] [ka]

[0014] [ka]

[0015] [ka]

[0016] [ka]

[0017] [ka]

[0018] [ka]

[0019] [ka]

[0020] [ka]

[0021] [ka]

[0022] [ka]

[0023] [ka]

[0024] [ka]

[0025] [ka]

[0026] [ka] In the formula, Me is methyl, tBu is t-butyl, and D is deuterium. <13> <1> ~ <12> 10. A material for an organic device, comprising the polycyclic aromatic compound according to any one of claims 1 to 9. <14> The light-emitting device includes a pair of electrodes consisting of an anode and a cathode, and a light-emitting layer disposed between the pair of electrodes, <1> ~ <12> 10. An organic electroluminescent device comprising the polycyclic aromatic compound according to any one of claims 1 to 9. <15> the light-emitting layer contains a host and the polycyclic aromatic compound as a dopant; <14> The organic electroluminescent device according to claim 1. <16> the host is an anthracene compound, a fluorene compound, or a dibenzochrysene compound; <15> The organic electroluminescent device according to claim 1. <17> <14> ~ <16> A display device or a lighting device comprising the organic electroluminescent device according to any one of the preceding claims. [Effects of the Invention]

[0027] The present invention provides a novel polycyclic aromatic compound useful as a material for organic devices such as organic electroluminescent elements. The polycyclic aromatic compound of the present invention can be used in the production of organic devices such as organic electroluminescent elements. [Brief explanation of the drawings]

[0028] [Figure 1] 1 is a schematic cross-sectional view showing an example of an organic electroluminescent device. DETAILED DESCRIPTION OF THE INVENTION

[0029] The present invention will be described in detail below. The following explanation of the constituent elements may be based on representative embodiments or specific examples, but the present invention is not limited to such embodiments. In this specification, a numerical range expressed using "to" means a range that includes the numerical values ​​before and after "to" as the lower and upper limits. In addition, in this specification, "hydrogen" in the explanation of structural formulas means "hydrogen atom (H)". Similarly, "carbon atom (C)" may be referred to as "carbon". In this specification, the term "adjacent groups" refers to two groups bonded to two adjacent atoms (two atoms directly bonded by a covalent bond) in a structural formula.

[0030] In this specification, "Me" represents methyl, "Et" represents ethyl, "nBu" represents n-butyl (normal butyl), "tBu" represents t-butyl (tertiary butyl), "iBu" represents isobutyl, "secBu" represents secondary butyl, "nPr" represents n-propyl (normal propyl), "iPr" represents isopropyl, "tAm" represents t-amyl, "2EH" represents 2-ethylhexyl, "tOct" represents t-octyl, "Ph" represents phenyl, "Mes" represents mesityl (2,4,6-trimethylphenyl), "Ad" represents 1-adamantyl, "Tf" represents trifluoromethanesulfonyl, "TMS" represents trimethylsilyl, and "D" represents deuterium. In this specification, the organic electroluminescent device may be referred to as an "organic EL device."

[0031] In this specification, chemical structures and substituents are sometimes represented by the number of carbon atoms. However, when a chemical structure is substituted with a substituent or when a substituent is further substituted with a substituent, the number of carbon atoms refers to the number of carbon atoms in each of the chemical structure and the substituent, and does not refer to the total number of carbon atoms in the chemical structure and the substituent, or the total number of carbon atoms in the substituent and the substituent. For example, "substituent B of carbon number Y substituted with substituent A of carbon number X" means that "substituent B of carbon number Y" is substituted with "substituent A of carbon number X," and the carbon number Y is not the total number of carbon atoms in substituents A and B. Also, for example, "substituent B of carbon number Y substituted with substituent A" means that "substituent B of carbon number Y" is substituted with "substituent A (with no carbon number restriction)," and the carbon number Y is not the total number of carbon atoms in substituents A and B.

[0032] This specification describes many structural formulas for aromatic compounds. Although aromatic compounds are described by combining double bonds and single bonds, in reality, due to π electron resonance, a single substance may have multiple equivalent resonance structures, in which double bonds and single bonds alternate. Although this specification describes only one resonance structure for each substance, unless otherwise specified, other organically equivalent resonance structures are also included.

[0033] In this specification, the expression "may be" is sometimes used, but this has the same meaning as "not being, or being."

[0034] <Explanation of rings and substituents> First, the rings and substituents used in this specification will be described in detail below. As used herein, the "aryl ring" includes, for example, an aryl ring having 6 to 30 carbon atoms, preferably an aryl ring having 6 to 16 carbon atoms, more preferably an aryl ring having 6 to 12 carbon atoms, and particularly preferably an aryl ring having 6 to 10 carbon atoms.

[0035] Specific examples of the "aryl ring" include a monocyclic benzene ring, a bicyclic bicyclic bicyclic naphthalene ring and an indene ring, a tricyclic terphenyl ring (m-terphenyl, o-terphenyl, p-terphenyl) and a fused tricyclic acenaphthylene ring, a fluorene ring, a phenalene ring, a phenanthrene ring, and an anthracene ring, fused tetracyclic triphenylene ring, a pyrene ring, a naphthacene ring, and a chrysene ring, fused pentacyclic perylene ring and a pentacene ring, etc. Furthermore, the fluorene ring, benzofluorene ring, and indene ring each include a structure in which a fluorene ring, a benzofluorene ring, a cyclopentane ring, etc. are spiro-bonded. The fluorene ring, benzofluorene ring, and indene ring also include rings in which two of the two hydrogen atoms of the methylene in the structure are replaced by alkyl such as methyl as the first substituent described below, resulting in a dimethylfluorene ring, dimethylbenzofluorene ring, dimethylindene ring, etc.

[0036] As used herein, 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, still more preferably heteroaryl rings having 2 to 15 carbon atoms, and particularly preferably heteroaryl rings having 2 to 10 carbon atoms. Furthermore, examples of the "heteroaryl ring" include heterocyclic rings containing, as ring-constituting atoms other than carbon, 1 to 5 heteroatoms selected from oxygen, sulfur, nitrogen, boron, selenium, phosphorus, and tellurium.

[0037] 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.), benzoselenophen Examples of the dihydroacridine 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, dihydroacridine rings, xanthene rings, and thioxanthene rings are also preferred in which two of the two hydrogen atoms of the methylenes in the ring structure are each replaced by an alkyl such as methyl as the first substituent described below, thereby forming a dimethyldihydroacridine ring, a dimethylxanthene ring, a dimethylthioxanthene ring, etc.In addition, bicyclic rings such as bipyridine ring, phenylpyridine ring, and pyridylphenyl ring, and tricyclic rings such as terpyridyl ring, bispyridylphenyl ring, and pyridylbiphenyl ring are also included as "heteroaryl rings." Furthermore, "heteroaryl rings" also include pyran rings.

[0038] In this specification, a substituent may be substituted with an additional substituent. For example, a specific substituent may be described as "substituted or unsubstituted." This means that the specific substituent is substituted with at least one additional substituent, or is not substituted. In the same sense, the term "optionally substituted" may also be used. In this specification, the specific substituent may be referred to as a "first substituent," and the additional substituent may be referred to as a "second substituent."

[0039] In this specification, the substituent group Zα consists of the substituents of the substituent group Z and a substituent represented by the formula (A30) described below.

[0040] 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 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 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 optionally 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 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; an arylthio optionally substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl, cycloalkyl, cyano, and halogen; alkenyl optionally substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl, cycloalkyl, cyano, and halogen; It consists of substituted silyl, cyano, and halogen. The aryl as the second substituent in each group of the substituent group Z may be further substituted with an aryl, heteroaryl, alkyl, cycloalkyl, cyano, or halogen. Similarly, the heteroaryl as the second substituent may be substituted with an aryl, heteroaryl, alkyl, cycloalkyl, cyano, or halogen.

[0041] In this 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 substituent group Z. For example, when a "substituted or unsubstituted" group is substituted, it may be substituted with at least one group selected from substituent group Z.

[0042] In this specification, "aryl" refers to, for example, aryl having 6 to 30 carbon atoms, and preferably aryl having 6 to 20 carbon atoms, aryl having 6 to 16 carbon atoms, aryl having 6 to 12 carbon atoms, or aryl having 6 to 10 carbon atoms.

[0043] Specific examples of "aryl" include monovalent groups obtained by removing one hydrogen atom from the above-mentioned "aryl ring." For example, the monocyclic ring system is phenyl, the bicyclic ring system is biphenylyl (2-biphenylyl, 3-biphenylyl, or 4-biphenylyl), the fused bicyclic ring system is naphthyl (1-naphthyl or 2-naphthyl), the tricyclic ring system is 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 is acenaphthylene-(1-, 3-, 4-, or 5-), -)yl, fluoren-(1-, 2-, 3-, 4-, or 9-)yl, phenalen-(1- or 2-)yl, phenanthrene-(1-, 2-, 3-, 4-, or 9-)yl, or anthracene-(1-, 2-, or 9-)yl, the tetracyclic ring systems quaterphenylyl (5'-phenyl-m-terphenyl-2-yl, 5'-phenyl-m-terphenyl-3-yl, 5'-phenyl fluorene-4-yl, m-quaterphenyl-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 radicals of spirofluorene.

[0044] The aryl as the second substituent also includes a structure in which the aryl is substituted with at least one group selected from the group consisting of aryl such as phenyl (specific examples are the groups described above), alkyl such as methyl (specific examples are the groups described below), and cycloalkyl such as cyclohexyl or adamantyl (specific examples are the groups described below). An example of such a group is a group in which the 9-position of the fluorenyl as the second substituent is substituted with an aryl such as phenyl, an alkyl such as methyl, or a cycloalkyl such as cyclohexyl or adamantyl.

[0045] The "arylene" is, for example, an arylene having 6 to 30 carbon atoms, and preferably an arylene having 6 to 20 carbon atoms, an arylene having 6 to 16 carbon atoms, an arylene having 6 to 12 carbon atoms, or an arylene having 6 to 10 carbon atoms. Specific examples of "arylene" include divalent groups obtained by removing one hydrogen atom from the above-mentioned "aryl" (monovalent group).

[0046] The "heteroaryl" is, for example, a heteroaryl having 2 to 30 carbon atoms, and preferably a heteroaryl having 2 to 25 carbon atoms, a heteroaryl having 2 to 20 carbon atoms, a heteroaryl having 2 to 15 carbon atoms, or a heteroaryl having 2 to 10 carbon atoms. The "heteroaryl" contains, in addition to carbon, one or more, preferably 1 to 5, heteroatoms selected from oxygen, sulfur, nitrogen, etc. as ring-constituting atoms.

[0047] 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, Examples include acridinyl, phenoxathiinyl, phenoxazinyl, phenothiazinyl, phenazinyl, phenazasilinyl, indolizinyl, furanyl, benzofuranyl, isobenzofuranyl, dibenzofuranyl, naphthobenzofuranyl, thienyl, benzothienyl, isobenzothienyl, dibenzothienyl, naphthobenzothienyl, a monovalent group of a benzophosphole oxide ring, a monovalent group of a dibenzophosphole oxide ring, furazanyl, thianthrenyl, indolocarbazolyl, benzoindolocarbazolyl, dibenzoindolocarbazolyl, imidazolinyl, and oxazolinyl. Other examples include a monovalent group of spiro[fluorene-9,9'-xanthene], a monovalent group of spirobi[silafluorene], and a monovalent group of benzoselenophene.

[0048] The heteroaryl as the second substituent also includes a structure in which the heteroaryl is substituted with at least one group selected from the group consisting of aryl such as phenyl (specific examples are the groups described above), alkyl such as methyl (specific examples are the groups described below), and cycloalkyl such as cyclohexyl or adamantyl (specific examples are the groups described below). An example of such a group is a carbazolyl group as the second substituent, where the 9-position is substituted with an aryl such as phenyl, an alkyl such as methyl, or a cycloalkyl such as cyclohexyl or adamantyl. Also included in the heteroaryl group as the second substituent are groups in which a nitrogen-containing heteroaryl such as pyridyl, pyrimidinyl, triazinyl, or carbazolyl is further substituted with phenyl or biphenylyl.

[0049] The "heteroarylene" is, for example, a heteroarylene having 2 to 30 carbon atoms, and preferably a heteroarylene having 2 to 25 carbon atoms, a heteroarylene having 2 to 20 carbon atoms, a heteroarylene having 2 to 15 carbon atoms, or a heteroarylene having 2 to 10 carbon atoms. Furthermore, the "heteroarylene" is, for example, a divalent group such as a heterocycle containing, in addition to carbon, 1 to 5 heteroatoms selected from oxygen, sulfur, and nitrogen as ring-constituting atoms. Specific examples of "heteroarylene" include divalent groups obtained by removing one hydrogen atom from the above-mentioned "heteroaryl" (monovalent group).

[0050] "Diarylamino" is an amino substituted with two aryls, and the details of the aryls can be found in the above explanation of "aryl". "Diheteroarylamino" refers to an amino group substituted with two heteroaryls, and the details of this heteroaryl can be found in the above description of "heteroaryl". "Arylheteroarylamino" refers to an amino group substituted with an aryl and a heteroaryl, and the details of the aryl and heteroaryl can be found in the explanations of "aryl" and "heteroaryl" given above.

[0051] The two aryls in the diarylamino as the first substituent may be bonded to each other via a linking group, the two heteroaryls in the diheteroarylamino as the first substituent may be bonded to each other via a linking group, and the aryl and heteroaryl in the arylheteroarylamino as the first substituent may be bonded to each other via a linking group. Here, the expression "bonded via a linking group" means that, for example, the two phenyls in diphenylamino form a bond via a linking group, as shown below. This explanation also applies to diheteroarylamino and arylheteroarylamino formed by aryls or heteroaryls.

[0052] [ka]

[0053] 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. R X are each independently alkyl, cycloalkyl, aryl, or heteroaryl, which may be substituted with alkyl, cycloalkyl, aryl, or heteroaryl. X )2, -C(-R X )=C(-R X )-, >Si(-R X )2 Two R in each 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 >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 do not bond to form a ring. Further examples of the linking group include alkenylene. Any hydrogen atom in the alkenylene can be independently selected from R 2X and R 2X are each independently alkyl, cycloalkyl, substituted silyl, aryl, or heteroaryl, which may be substituted with alkyl, cycloalkyl, substituted silyl, or aryl. X )=C(-R X )- Two R's X may be bonded to each other 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.

[0054] In this specification, unless otherwise specified, when "diarylamino," "diheteroarylamino," or "arylheteroarylamino" is simply described, it is assumed that the following explanation is added: "two aryls of the diarylamino may be bonded to each other via a linking group," "two heteroaryls of the diheteroarylamino may be bonded to each other via a linking group," and "aryl and heteroaryls of the arylheteroarylamino may be bonded to each other via a linking group," respectively.

[0055] "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, >CO, >C=S, >S=O, >S(=O)2, >Se(=O), >Se(=O)2, >P(=O), >B(-R), >C(-R)2, >Si(-R)2, or >Se). Here, R in -CR=CR-, R in >NR, R in >B(-R), R in >C(-R), and R in >Si(-R) are aryl, heteroaryl, diarylamino, alkyl, alkenyl, alkynyl, cycloalkyl, alkoxy, or aryloxy, and at least one hydrogen atom in the R may be further substituted with an aryl, heteroaryl, alkyl, alkenyl, alkynyl, or cycloalkyl. Two adjacent Rs may be bonded to form a ring, forming a cycloalkylene, arylene, or heteroarylene. For details of the substituents listed here, the above-mentioned descriptions of "aryl," "arylene," "heteroaryl," "heteroarylene," and "diarylamino," as well as the below-mentioned descriptions of "alkyl," "alkenyl," "alkynyl," "cycloalkyl," "cycloalkylene," "alkoxy," and "aryloxy" may be cited. Furthermore, when the term "diarylboryl" is used simply in this specification, unless otherwise specified, it is understood to include the explanation that "the two aryls of the diarylboryl may be bonded to each other via a single bond or a linking group."

[0056] The "alkyl" may be either straight-chain or branched-chain, for example, a straight-chain alkyl having 1 to 24 carbon atoms or a branched-chain alkyl having 3 to 24 carbon atoms, and is preferably an alkyl having 1 to 18 carbon atoms (branched-chain alkyl having 3 to 18 carbon atoms), an alkyl having 1 to 12 carbon atoms (branched-chain alkyl having 3 to 12 carbon atoms), an alkyl having 1 to 6 carbon atoms (branched-chain alkyl having 3 to 6 carbon atoms), an alkyl having 1 to 5 carbon atoms (branched-chain alkyl having 3 to 5 carbon atoms), or an alkyl having 1 to 4 carbon atoms (branched-chain alkyl having 3 to 4 carbon atoms).

[0057] Specific examples of "alkyl" include methyl, ethyl, n-propyl, isopropyl, 1-ethyl-1-methylpropyl, 1,1-diethylpropyl, 1,1,2-trimethylpropyl, 1,1,2,2-tetramethylpropyl, 1-ethyl-1,2,2-trimethylpropyl, n-butyl, isobutyl, s-butyl, t-butyl, 2-ethylbutyl, 1,1-dimethylbutyl, 3,3-dimethylbutyl, 1,1-diethylbutyl, 1-ethyl-1-methylbutyl, 1-propyl-1-methylbutyl, 1,1,3-trimethylbutyl, 1-ethyl-1,3-dimethylbutyl, n-pentyl, isopentyl, neopentyl, t-pentyl (t-amyl), 1-methylpentyl, 2-propylpentyl, 1,1-dimethylpentyl, 1-ethyl-1-methylpentyl, 1-propyl-1 -methylpentyl, 1-butyl-1-methylpentyl, 1,1,4-trimethylpentyl, n-hexyl, 1-methylhexyl, 2-ethylhexyl, 1,1-dimethylhexyl, 1-ethyl-1-methylhexyl, 1,1,5-trimethylhexyl, 3,5,5-trimethylhexyl, n-heptyl, 1-methylheptyl, 1-hexylheptyl, 1,1-dimethylheptyl, 2,2-dimethylhexyl Examples of the alkyl group include methylheptyl, 2,6-dimethyl-4-heptyl, n-octyl, t-octyl (1,1,3,3-tetramethylbutyl), 1,1-dimethyloctyl, n-nonyl, n-decyl, 1-methyldecyl, n-undecyl, n-dodecyl, n-tridecyl, n-tetradecyl, n-pentadecyl, n-hexadecyl, n-heptadecyl, n-octadecyl, and n-eicosyl.

[0058] An "alkylene" is a divalent group obtained by removing any hydrogen from an "alkyl", such as methylene, ethylene, or propylene.

[0059] For "alkenyl," the explanation of "alkyl" above can be referred to. It is a group in which a C═C single bond in the "alkyl" structure is replaced with a C═C double bond, and also includes groups in which not only one but two or more single bonds are replaced with double bonds (also called alkadiene-yl or alkatriene-yl).

[0060] Specific examples of "alkenyl" 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, still more 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, and 5-hexenyl.

[0061] "Alkenylene" is a divalent group obtained by removing any hydrogen from "alkenyl", and examples include vinylene.

[0062] For "alkynyl," the explanation of "alkyl" above can be referred to. It is a group in which a C≡C single bond in the "alkyl" structure is replaced with a C≡C triple bond, and also includes groups in which not only one but two or more single bonds are replaced with triple bonds (also called alkadiyn-yl or alkatolyyn-yl).

[0063] The "cycloalkyl" is, for example, a cycloalkyl having 3 to 24 carbon atoms, and preferably a cycloalkyl having 3 to 20 carbon atoms, a cycloalkyl having 3 to 16 carbon atoms, a cycloalkyl having 3 to 14 carbon atoms, a cycloalkyl having 3 to 12 carbon atoms, a cycloalkyl having 5 to 10 carbon atoms, a cycloalkyl having 5 to 8 carbon atoms, a cycloalkyl having 5 to 6 carbon atoms, or a cycloalkyl having 5 carbon atoms.

[0064] Specific examples of "cycloalkyl" include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl, or alkyl (particularly methyl) substituted derivatives thereof having 1 to 5 carbon atoms or 1 to 4 carbon atoms, 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.

[0065] "Cycloalkylene" is, for example, cycloalkylene having 3 to 24 carbon atoms, and preferably cycloalkylene having 3 to 20 carbon atoms, cycloalkylene having 3 to 16 carbon atoms, cycloalkylene having 3 to 14 carbon atoms, cycloalkylene having 3 to 12 carbon atoms, cycloalkylene having 5 to 10 carbon atoms, cycloalkylene having 5 to 8 carbon atoms, cycloalkylene having 5 to 6 carbon atoms, cycloalkylene having 5 carbon atoms, etc. A specific example of "cycloalkylene" is a structure in which one hydrogen atom is removed from the above-mentioned "cycloalkyl" (monovalent group) to form a divalent group.

[0066] "Cycloalkenyl" refers to a group having a structure in which at least one pair of single bonds between two carbon atoms in the above-mentioned "cycloalkyl" has become a double bond (for example, a group in which -CH-CH- is replaced with -CH=CH-), and does not fall under the category of aryl. Specific examples include 1-cyclohexenyl and 1-cyclopentenyl.

[0067] "Alkoxy" is a group represented by "Alk-O- (Alk is alkyl)", and the above explanation of "alkyl" can be cited for details of the alkyl.

[0068] "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. "Arylthio" is a group represented by "Ar-S-(Ar is aryl)", and the above explanation of "aryl" can be cited for details of the aryl.

[0069] The "substituted silyl" is, for example, a silyl substituted with at least one of aryl, alkyl, and cycloalkyl, and is preferably triarylsilyl, trialkylsilyl, tricycloalkylsilyl, dialkylcycloalkylsilyl, or alkyldicycloalkylsilyl.

[0070] "Triarylsilyl" is a silyl group substituted with three aryl groups, and the details of the aryl groups can be found in the above description of "aryl." Specific examples of "triarylsilyl" include triphenylsilyl, diphenylmononaphthylsilyl, monophenyldinaphthylsilyl, and trinaphthylsilyl.

[0071] "Trialkylsilyl" is a silyl group substituted with three alkyl groups, and the details of this alkyl can be found in the above explanation of "alkyl". Specific examples of the "trialkylsilyl" include trimethylsilyl, triethylsilyl, tri-n-propylsilyl, triisopropylsilyl, tri-n-butylsilyl, triisobutylsilyl, tri-s-butylsilyl, tri-t-butylsilyl, ethyldimethylsilyl, n-propyldimethylsilyl, isopropyldimethylsilyl, n-butyldimethylsilyl, isobutyldimethylsilyl, s-butyldimethylsilyl, t-butyldimethylsilyl, methyldiethylsilyl, n-propyldiethylsilyl, isopropyldiethylsilyl, n-butyldiethylsilyl, s-butyldiethylsilyl, t-butyldiethylsilyl, methyldi-n-propylsilyl, ethyldi-n-propylsilyl, n-butyldi-n-propylsilyl, s-butyldi-n-propylsilyl, t-butyldi-n-propylsilyl, methyldiisopropylsilyl, ethyldiisopropylsilyl, n-butyldiisopropylsilyl, s-butyldiisopropylsilyl, and t-butyldiisopropylsilyl.

[0072] "Tricycloalkylsilyl" is a silyl group substituted with three cycloalkyl groups, and the details of this cycloalkyl can be found in the above description of "cycloalkyl". Specific "tricycloalkylsilyl" includes, for example, tricyclopentylsilyl or tricyclohexylsilyl.

[0073] "Dialkylcycloalkylsilyl" is a silyl group substituted with two alkyls and one cycloalkyl, and the details of the alkyl and cycloalkyl can be found in the explanations of "alkyl" and "cycloalkyl" above.

[0074] "Alkyldicycloalkylsilyl" is a silyl group substituted with one alkyl and two cycloalkyl, and the details of the alkyl and cycloalkyl can be found in the explanations of "alkyl" and "cycloalkyl" above.

[0075] "Halogen" is fluorine, chlorine, bromine or iodine, preferably fluorine, chlorine or bromine, more preferably fluorine or chlorine, and even more preferably fluorine.

[0076] When cyano or halogen is substituted, it is also preferable that all or part of the hydrogen atoms in the aryl or heteroaryl in the structure are replaced with cyano or halogen.

[0077] The substituent represented by formula (A30) has the following structure: [ka]

[0078] In formula (A30), Ak is hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted cycloalkyl, or substituted or unsubstituted cycloalkenyl, in which at least one -CH2- may be replaced by -O- or -S-; R Ak is a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted alkyl, or a substituted or unsubstituted cycloalkyl; R Ak may be bonded to Ak via a linking group or a single bond, and * indicates the bonding position.

[0079] In formula (A30), Ak is the above-mentioned substituent, so it does not conjugate with the lone electron pair on N, and therefore the lone electron pair can be conjugated with the π electron to which it is bonded, allowing for a greater wavelength shift than when there is an aryl or the like at the same position. This also has a similar effect on the multiple resonance effect, allowing for a greater improvement in thermally activated delayed fluorescence (TADF) properties.

[0080] R Akis preferably aryl which may be substituted with alkyl or cycloalkyl, heteroaryl which may be substituted with alkyl or cycloalkyl, alkyl or cycloalkyl, more preferably aryl which may be substituted with alkyl, heteroaryl which may be substituted with alkyl, alkyl or cycloalkyl, still more preferably aryl which may be substituted with alkyl, and particularly preferably phenyl which may be substituted with methyl.

[0081] In formula (A30), Ak is preferably alkyl having 1 to 6 carbon atoms or cycloalkyl having 3 to 14 carbon atoms, more preferably alkyl having 1 to 4 carbon atoms or cycloalkyl having 3 to 8 carbon atoms, more preferably alkyl having 1 to 4 carbon atoms, and even more preferably methyl.

[0082] R Ak and Ak may be the same or different, and are preferably different.

[0083] 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:

[0084] [ka] In the above formulas, * indicates the bonding position.

[0085] [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-, -C(=O)-, -C(=S)-, -S(=O)-, -S(=O)2-, -Se(=O)-, -Se(=O)2-, -P(=O)-, -B(-R)-, -Si(-R)2-, and -Se-, for example, the following structure. R of -CHR-CHR-, R of -CR-CR-, R of -CR=CR-, R of -N(-R)-, R of -C(-R)-, R of -B(-R)-, and R of -Si(-R)- are each independently hydrogen, aryl optionally substituted with alkyl or cycloalkyl, heteroaryl optionally substituted with alkyl or cycloalkyl, alkyl optionally substituted with cycloalkyl, alkenyl optionally substituted with alkyl or cycloalkyl, alkynyl optionally substituted with alkyl or cycloalkyl, or cycloalkyl optionally substituted with alkyl or cycloalkyl. Two adjacent Rs may be bonded to form a ring, forming a cycloalkylene, arylene, or heteroarylene.

[0086] [ka]

[0087] As the linking group, a single bond and -CR=CR-, -N(-R)-, -O-, -S-, -C(-R)2-, -Si(-R)2-, and -Se- are preferred, a single bond and -CR=CR-, -N(-R)-, -O-, -S-, and -C(-R)2- as linking groups are more preferred, a single bond and -CR=CR-, -N(-R)-, -O-, and -S- as linking groups are even more preferred, and a single bond is most preferred.

[0088] The position at which two Rs are bonded by the bonding group is not particularly limited as long as it is a position where bonding is possible, but it is preferable that they are bonded at the most adjacent positions. For example, when the two groups are phenyl, it is preferable that they are bonded at positions ortho (2nd position) relative to the bonding position (1st position) of "C" or "Si" in the phenyl (see the structural formula above).

[0089] <Stereoisomers, etc.> The polycyclic aromatic compounds of the present invention may exist as enantiomers or diastereomers depending on the type of substituents, etc., but regardless of the structural formula shown, any pure stereoisomer, any mixture of stereoisomers, racemate, etc. are all intended to be encompassed within the scope of the present invention.

[0090] <1. Polycyclic aromatic compounds> <Overall structure> Polycyclic aromatic compounds in which aromatic rings are linked by heteroatoms such as boron, nitrogen, oxygen, and sulfur have already been found to have large HOMO-LUMO gaps (band gaps in thin films, Eg). This is because the six-membered rings containing heteroatoms have low aromaticity, suppressing the decrease in the HOMO-LUMO gap associated with the expansion of the conjugated system. We have also found that the HOMO-LUMO gap can be arbitrarily changed depending on the type and linking method of the heteroatoms. This is thought to be due to the ability to arbitrarily change the HOMO and LUMO energies depending on the spatial extent and energy of the unoccupied orbitals or lone pairs of the heteroatoms.

[0091] These polycyclic aromatic compounds have narrow half-widths of their fluorescence emission peaks due to the localization of the excited SOMO1 and SOMO2 on each atom caused by electronic perturbation of the heteroatoms, and when used as dopants in organic electroluminescent devices, they can emit light with high color purity. S1T1 The thermally activated delayed fluorescence is exhibited, and high efficiency can be obtained when used as an emitting dopant in an organic EL device. Furthermore, by introducing substituents, the HOMO and LUMO energies can be adjusted arbitrarily, making it possible to optimize the ionization potential and electron affinity depending on the surrounding materials.

[0092] In the present invention, it has been found that polycyclic aromatic compounds in which aromatic rings such as benzene rings are linked by heteroatoms such as boron and nitrogen, and that the polycyclic aromatic compounds have a structure consisting of one or more structural units represented by formula (1) having substituents at specific positions, enable the production of organic electroluminescent devices with a longer lifetime than polycyclic aromatic compounds with a similar structure.

[0093] The polycyclic aromatic compound of the present invention has a structure consisting of one or more structural units represented by formula (1). In this specification, a polycyclic aromatic compound having a structure consisting of one or more structural units represented by formula (1) may be referred to as a "polycyclic aromatic compound containing a structural unit represented by formula (1)."

[0094] [ka] In formula (1), R c1 ~R c4 At least one of the groups is a group represented by formula (1-1), and the others are hydrogen or a substituent. The symbols in each formula are explained in detail below.

[0095] <R c1 ~R c4 > In formula (1), R c1 ~R c4 At least one of R is a group represented by formula (1-1), and the others are hydrogen or a substituent. c1 ~R c4 It has been found that by introducing at least one group represented by formula (1-1) into the compound, a compound that enables the production of a more efficient device can be obtained.

[0096] R c1 ~R c4It is more preferable that one of R is a group represented by formula (1-1), and the other three are hydrogen or deuterium. c1 ~R c4 Among them, R c1 , R c2 or R c3 is preferably a substituent, and R c2 or R c3 is more preferably a substituent, and R c3 is particularly preferably a substituent.

[0097] R c1 ~R c4 When each of R is a substituent, the substituent may be at least one substituent selected from the substituent group Zα, preferably at least one substituent selected from the substituent group Z, more preferably a substituted or unsubstituted alkyl, a substituted or unsubstituted aryl, or a substituted or unsubstituted heteroaryl, further preferably an alkyl or an aryl which may be substituted with an alkyl, and particularly preferably t-butyl, or a phenyl which may be substituted with methyl or t-butyl. c1 ~R c4 Among these, at least one is preferably a substituted or unsubstituted aryl or a substituted or unsubstituted heteroaryl. In this case, at least one is more preferably an aryl which may be substituted with alkyl, and even more preferably a phenyl which may be substituted with methyl or t-butyl. A structure in which the aryl ring or heteroaryl ring in the substituent is condensed with a cycloalkane as described below is also preferred. In this case, a structure in which a partial structure represented by formula (B11) or formula (B12) described below is formed is particularly preferred.

[0098] <R a1 ~R a3 > In formula (1), R a1 ~R a3 are each independently hydrogen or a substituent. R a1 ~R a3When is a substituent, the substituent is at least one substituent selected from the substituent group Zα, preferably at least one substituent selected from the substituent group Z, more preferably substituted or unsubstituted alkyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted aryl, substituted or unsubstituted diarylamino, or substituted silyl, and more preferably substituted or unsubstituted alkyl, Substituted or unsubstituted aryl or substituted silyl is more preferred, and methyl, t-butyl, triphenylmethyl, substituted or unsubstituted phenyl, or triphenylsilyl is particularly preferred. Examples of preferred substituents described below can also be referenced. R a1 ~R a3 When two or more of the groups are substituents, the substituents may be the same or different. R a1 and R a3 are all hydrogen, and R a2 is preferably hydrogen, substituted or unsubstituted aryl, substituted or unsubstituted alkyl, or substituted silyl, and R a2 More preferably, R is t-butyl, methyl, triphenylmethyl, substituted or unsubstituted phenyl, or triphenylsilyl; a2 More preferably, is t-butyl, or phenyl unsubstituted or substituted with t-butyl.

[0099] <R b1 ~R b4 > In formula (1), R b1 ~R b4 are each independently hydrogen or a substituent. R b1 ~R b4When R is a substituent, the substituent may be at least one substituent selected from the substituent group Zα, preferably at least one substituent selected from the substituent group Z, more preferably a substituted or unsubstituted alkyl, a substituted or unsubstituted cycloalkyl, a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, or a substituted or unsubstituted diarylamino. Examples of preferred substituents described below can also be referenced. b1 ~R b4 When two or more of the groups are substituents, the substituents may be the same or different.

[0100] R b1 ~R b4 In R b2 or R b3 is preferably hydrogen or a substituent, and the others are each hydrogen; R b2 or R b3 It is more preferred that R is a substituent and the others are each hydrogen. b2 or R b3 When R is a substituent, 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, more preferably t-butyl, a substituted or unsubstituted diphenylamino, a substituted or unsubstituted N-phenyl-(1- or 2-)naphthylamino, or a substituted or unsubstituted carbazolyl, and even more preferably t-butyl or diphenylamino optionally substituted with t-butyl or phenyl. b2 and R b3 A structure in which R are bonded to each other and form a cycloalkene together with the carbon atoms to which they are bonded is also preferred. This structure corresponds to a structure in which a cycloalkane is fused to an aryl ring, b. In particular, R b2 and R b3 are bonded to each other to form a partial structure represented by formula (B11) or (B12) described below.

[0101] <Y 1 > In formula (1), Y 1 is B, P, P=O, P=S, Al, Ga, As, Si-R YI , or Ge-R YG and R YI and R YG R is a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted alkyl, or a substituted or unsubstituted cycloalkyl. YI and R YG Particularly preferred is aryl having 6 to 10 carbon atoms (for example, phenyl, naphthyl, etc.), alkyl having 1 to 5 carbon atoms (for example, methyl, ethyl, etc.), or cycloalkyl having 5 to 10 carbon atoms (preferably cyclohexyl or adamantyl). Y 1 is preferably B, P=O, or P=S, and more preferably B.

[0102] <X 1 and X 2 > X in formula (1) 1 and X 2 are independently >O, >NR NX ,>C(-R CX )2, >Si(-R IX )2, >S, or >Se.

[0103] R NX R is hydrogen, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted alkyl, or substituted or unsubstituted cycloalkyl. NX is preferably a substituted or unsubstituted aryl or a substituted or unsubstituted heteroaryl.

[0104] R CX are each independently hydrogen, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted alkyl, or substituted or unsubstituted cycloalkyl; CX may be bonded to each other to form a ring. CXis preferably methyl or phenyl.

[0105] R IX are each independently hydrogen, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted alkyl, or substituted or unsubstituted cycloalkyl; IX may be bonded to each other to form a ring. IX is preferably a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, or a substituted or unsubstituted alkyl, and more preferably a substituted or unsubstituted phenyl or methyl.

[0106] X 1 and X 2 are all >NR NX In this case, R NXare each independently hydrogen, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted alkyl, or substituted or unsubstituted cycloalkyl, preferably substituted or unsubstituted aryl or substituted or unsubstituted heteroaryl, and more preferably substituted or unsubstituted phenyl, substituted or unsubstituted naphthyl, substituted or unsubstituted biphenylyl, substituted or unsubstituted terphenylyl, substituted or unsubstituted quaterphenylyl, substituted or unsubstituted dibenzofuranyl, substituted or unsubstituted dibenzothienyl, substituted or unsubstituted fluorenyl, or substituted or unsubstituted carbazolyl, and more preferably substituted or unsubstituted phenyl, substituted or unsubstituted biphenylyl, substituted or unsubstituted terphenylyl, substituted or unsubstituted quaterphenylyl, substituted or unsubstituted dibenzofuranyl, substituted or unsubstituted dibenzothienyl, substituted or unsubstituted fluorenyl, or substituted or unsubstituted carbazolyl. R is more preferably phenylyl, substituted or unsubstituted dibenzofuranyl, or substituted or unsubstituted carbazolyl, even more preferably substituted or unsubstituted phenyl, substituted or unsubstituted biphenylyl, or substituted or unsubstituted dibenzofuranyl, even more preferably phenyl which may be substituted with an aryl, alkyl, or cycloalkyl, biphenylyl which may be substituted with an aryl, alkyl, or cycloalkyl, or dibenzofuranyl which may be substituted or unsubstituted with an alkyl or cycloalkyl, and even more preferably phenyl which may be substituted with methyl, t-butyl, or cycloalkyl, or 2-biphenylyl which may be substituted with methyl, t-butyl, or cycloalkyl. NX By selecting the above, it is possible to obtain a compound that can realize an organic EL device having higher heat resistance and a longer life. R NX A structure in which the aryl ring or heteroaryl ring in the ring is condensed with a cycloalkane as described later is also preferred. In this case, a structure in which a partial structure represented by formula (B11) or formula (B12) described later is formed is particularly preferred.

[0107] X 1 and X 2 All are >NR NX When two R NXmay be the same or different.

[0108] <X 1 or X 2 Explanation of the change in ring structure due to bonding with the ring> X 1 and X 2 R in at least one of NX , R CX , and R IX are connected to R by a linking group or a single bond, respectively. a3 or R b1 may be bonded to at least one of the carbon atoms to which R a1 or R c4 may be bonded to at least one of the carbon atoms to which "R a3 or R b1 "Carbon to which R is bonded" and "R a1 or R c4 The carbon to which R is bonded is a1 , R a3 , R b1 and R c4 means the carbon of the ring to which R is attached. Consequently, the linking group or single bond at the time of said attachment a1 , R a3 , R b1 and R c4 Replace at least one of them.

[0109] R NX , R CX and R IXExamples of the linking group when each is bonded to a ring include -CH2-CH2-, -CHR-CHR-, -CR2-CR2-, -CH=CH-, -CR=CR-, -C≡C-, -N(-R)-, -O-, -S-, -C(-R)2-, -C(=O)-, -C(=S)-, -S(=O)-, -S(=O)2-, -Se(=O)-, -Se(=O)2-, -P(=O)-, -B(-R)-, -Si(-R)2-, and -Se-. Of these, -CH=CH-, -CR=CR-, -N(-R)-, -O-, -S-, and -C(-R)2- are preferred, -CH=CH-, -CR=CR-, -N(-R)-, -O-, and -S- are more preferred, and -CR=CR-, -N(-R)-, -O-, and -S- are even more preferred. The R of "-CHR-CHR-", R of "-CR-CR-", R of "-CR=CR-", R of "-N(-R)-", R of "-C(-R)-", R of "-B(-R)-", and R of "-Si(-R)-" are each independently hydrogen, aryl optionally substituted with alkyl or cycloalkyl, heteroaryl optionally substituted with alkyl or cycloalkyl, alkyl optionally substituted with 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. Two Rs bonded to the same element may be bonded to each other to form a ring. Two adjacent Rs may be bonded to each other to form a cycloalkylene ring, an arylene ring, or a heteroarylene ring. These rings may also be substituted with alkyl or cycloalkyl.

[0110] >NR NX R in NX R a3 , R b1 , R a1 , or R c4 Examples of the fused ring formed by bonding with R include a carbazole ring (R NX is bonded by a single bond), phenoxazine ring (R is phenyl NX-O- bond), phenothiazine ring (phenyl R NX -S- bonded), or an acridone ring (R is phenyl NX Examples include -C(=O)- bond.

[0111] Furthermore, the following partial structure (A10) may be formed by the above linkage. [ka]

[0112] In formula (A10), R A1 ~R A4 are each independently hydrogen, optionally substituted alkyl, or optionally substituted cycloalkyl; R A1 ~R A4 Any 2 to 4 of the rings may be bonded to each other by a linking group or a single bond, and X is bonded to one of the two rings at the positions marked with two * and to the other ring at the position marked with **. That is, N in formula (A10) is a ring in which X is >NR NX >NR when NX The atoms on the ring bonded at the two * positions may be adjacent atoms (preferably carbon atoms). When the polycyclic aromatic compound contains a structure represented by formula (A10), the number thereof may be one or two (preferably one).

[0113] In formula (A10), R A1 ~R A4 Any two to four of these may be linked to each other via a linking group or a single bond. R A1 ~R A4 is any two (R A1 and R A4 , R A1 and R A4 and R A2 and R A3 , R A1 and R A2 , R A3 and R A4 , R A1 and R A2 and RA3 and R A4 ) are preferably bonded to each other by a linking group or a single bond, and R A1 and R A4 are more preferably bonded to each other via a linking group or a single bond. Examples of the divalent group formed by bonding to each other include alkylene and cycloalkylene. At least one hydrogen in the alkylene may be substituted with an alkyl or cycloalkyl, and at least one (preferably one) -CH2- in the alkylene may be substituted with -O- and -S-. The divalent group formed by bonding to each other is preferably a straight-chain alkylene having 2 to 5 carbon atoms, more preferably a straight-chain alkylene having 3 or 4 carbon atoms, and even more preferably a straight-chain alkylene having 4 carbon atoms (-(CH2)4-). It is particularly preferred that the straight-chain alkylene having 4 carbon atoms (-(CH2)4-) is unsubstituted.

[0114] The remaining R that is not involved in the linkage by a linking group or single bond A1 ~R A4 are each independently preferably hydrogen or an alkyl which may be substituted, more preferably an alkyl having 1 to 6 carbon atoms which may be substituted, further preferably an unsubstituted alkyl having 1 to 6 carbon atoms, and most preferably methyl. That is, the partial structure represented by formula (A10) is preferably a structure represented by the following formula (A11).

[0115] [ka] In formula (A11), Me is methyl, and is bonded to one of the two rings to which X is bonded at the positions marked with two *, and to the other ring at the position marked with **.

[0116] <R d1 ~R d7 > In formula (1-1), R d1 ~R d7 are each independently hydrogen or a substituent. Rd1 ~R d7 When R is a substituent, the substituent may be at least one substituent selected from the substituent group Zα, preferably at least one substituent selected from the substituent group Z, more preferably substituted or unsubstituted alkyl, substituted or unsubstituted cycloalkyl, or substituted or unsubstituted diarylamino, even more preferably substituted or unsubstituted alkyl, and particularly preferably unsubstituted alkyl. Examples of preferred substituents described below can also be referenced. R d1 ~R d7 When two or more of the groups are substituents, the substituents may be the same or different.

[0117] R d1 ~R d7 In R d3 , R d4 , R d5 , or R d7 is preferably a substituent, and R d4 or R d7 is a substituent, R d4 and R d7 is a substituent, or R d3 and R d5 is more preferably a substituent, and R d4 is more preferably a substituent. d3 and R d4 A structure in which R are bonded to each other to form a cycloalkene together with the carbon atoms to which they are bonded is also preferred. This structure corresponds to a structure in which a cycloalkane is condensed with an aryl ring of formula (1-1). In particular, R d3 and R d4 A preferred example is a structure in which R are bonded to each other to form a partial structure represented by formula (B11) or (B12) described below. d1 ~R d7 It is also more preferred that all of R are hydrogen or deuterium. d3 , R d4 , R d5 , or R d7When R is a substituent, the substituent is preferably a substituted or unsubstituted alkyl, a substituted or unsubstituted cycloalkyl, or a substituted or unsubstituted diarylamino, more preferably an alkyl or a cycloalkyl which may be substituted with an alkyl, and even more preferably methyl or t-butyl. d1 ~R d7 It is also preferred that each R is independently hydrogen, substituted or unsubstituted aryl, or unsubstituted alkyl. d1 ~R d3 , R d5 ~R d7 are all hydrogen, and R d4 More preferably, is hydrogen, substituted or unsubstituted aryl, or unsubstituted alkyl, and even more preferably is hydrogen, methyl, or t-butyl.

[0118] <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). Examples of polycyclic aromatic compounds having a structure consisting of one of the structural units include polycyclic aromatic compounds represented by formula (1). Examples of polycyclic aromatic compounds having a structure consisting of two or more structural units represented by formula (1) include compounds corresponding to multimers of polycyclic aromatic compounds represented by the formulas explained above as the structural unit represented by formula (1). The multimer is preferably a dimer to hexamer, more preferably a dimer to trimer, and particularly preferably a dimer. The multimer may be in a form having a plurality of the above structural units in one compound, and any ring (R a1 ~R a3 , R b1 ~R b4 , or R c1 ~R c4 The benzene ring to which R is bonded may be shared by a plurality of structural units. a1 ~R a3 , R b1 ~R b4 , or R c1 ~R c4is bonded) may be bonded so that the structural units are condensed with each other. Also, a plurality of the structural units may be bonded to each other via a linking group such as a single bond, alkylene having 1 to 3 carbon atoms, phenylene, or naphthylene. Among these, a structure in which the structural units are bonded to each other so as to share a ring 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.

[0119] <Preferred Substituents> In polycyclic aromatic compounds used as emitting dopants (and in other compounds used as dopants), a tertiary alkyl represented by the following formula (tR) is particularly preferred as an "alkyl"-containing substituent. This is because such bulky substituents increase the intermolecular distance, thereby improving the luminescence quantum yield (PLQY). Substituents in which the tertiary alkyl represented by formula (tR) is substituted with another substituent as a second substituent are also preferred. Specific examples include 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). 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 of formula (tR).

[0120] [ka]

[0121] In the formula (tR), R a , R b , and R care each independently alkyl having 1 to 24 carbon atoms, any -CH2- in the alkyl may be replaced with -O-, and the group represented by formula (tR) has * as the bonding position.

[0122] R a , R b and R c The "alkyl having 1 to 24 carbon atoms" may be either a straight chain or a branched chain, and examples thereof include a straight chain alkyl having 1 to 24 carbon atoms or a branched chain alkyl having 3 to 24 carbon atoms, an alkyl having 1 to 18 carbon atoms (branched chain alkyl having 3 to 18 carbon atoms), an alkyl having 1 to 12 carbon atoms (branched chain alkyl having 3 to 12 carbon atoms), an alkyl having 1 to 6 carbon atoms (branched chain alkyl having 3 to 6 carbon atoms), and an alkyl having 1 to 4 carbon atoms (branched chain alkyl having 3 to 4 carbon atoms).

[0123] 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.

[0124] R a , R b , and R c Specific examples of alkyl include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, s-butyl, t-butyl, n-pentyl, isopentyl, neopentyl, t-pentyl, n-hexyl, 1-methylpentyl, 4-methyl-2-pentyl, 3,3-dimethylbutyl, 2-ethylbutyl, n-heptyl, 1-methylhexyl, n-octyl, t-octyl, 1-methylheptyl, 2 1-ethylhexyl, 2-propylpentyl, n-nonyl, 2,2-dimethylheptyl, 2,6-dimethyl-4-heptyl, 3,5,5-trimethylhexyl, n-decyl, n-undecyl, 1-methyldecyl, n-dodecyl, n-tridecyl, 1-hexylheptyl, n-tetradecyl, n-pentadecyl, n-hexadecyl, n-heptadecyl, n-octadecyl, and n-eicosyl.

[0125] Examples of the group represented by formula (tR) include t-butyl, t-amyl, 1-ethyl-1-methylpropyl, 1,1-diethylpropyl, 1,1-dimethylbutyl, 1-ethyl-1-methylbutyl, 1,1,3,3-tetramethylbutyl, 1,1,4-trimethylpentyl, 1,1,2-trimethylpropyl, 1,1-dimethyloctyl, 1,1-dimethylpentyl, 1,1-dimethylheptyl, 1,1,5-trimethylhexyl, 1-ethyl- Examples include 1-methylhexyl, 1-ethyl-1,3-dimethylbutyl, 1,1,2,2-tetramethylpropyl, 1-butyl-1-methylpentyl, 1,1-diethylbutyl, 1-ethyl-1-methylpentyl, 1,1,3-trimethylbutyl, 1-propyl-1-methylpentyl, 1,1,2-trimethylpropyl, 1-ethyl-1,2,2-trimethylpropyl, 1-propyl-1-methylbutyl, 1,1-dimethylhexyl, etc. Among these, t-butyl and t-amyl are preferred.

[0126] The substituent is also preferably a substituent represented by formula (A30).

[0127] The emission wavelength can be adjusted by the steric hindrance, electron donating property and electron withdrawing property of the structure of the substituent possessed by the compound used as a dopant (assisting dopant or emitting dopant). 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 tribenzazepinyl. From the viewpoint of ease of synthesis, a larger steric hindrance is preferred for selective synthesis, and specifically, t-butyl, t-amyl, t-octyl, adamantyl, o-tolyl, p-tolyl, 2,4-xylyl, 2,5-xylyl, 2,6-xylyl, 2,4,6-mesityl, di-p-tolylamino, bis(p-(t-butyl)phenyl)amino, 3,6-dimethylcarbazolyl, and 3,6-di-t-butylcarbazolyl are preferred.

[0128] In the following structural formula, * represents a bond position. [ka]

[0129] [ka]

[0130] [ka]

[0131]

change

[0132]

change

[0133]

change

[0134]

change

[0135]

change

[0136]

change

[0137]

change

[0138]

change

[0139]

change

[0140]

change

[0141]

change

[0142] The polycyclic aromatic compound having a structure consisting of one or more structural units represented by formula (1) preferably has a structure containing at least one tertiary alkyl (such as t-butyl or t-amyl), neopentyl, or adamantyl group represented by the above formula (tR), and preferably contains a tertiary alkyl (such as t-butyl or t-amyl) represented by formula (tR). This is because such bulky substituents increase the intermolecular distance, thereby improving the luminescence quantum yield (PLQY). Diarylamino is also preferred as the substituent. Furthermore, diarylamino substituted with a group represented by formula (tR), carbazolyl (preferably N-carbazolyl) substituted with a group represented by formula (tR), or benzocarbazolyl (preferably N-benzocarbazolyl) substituted with a group represented by formula (tR) are also preferred. Substitution of the group of formula (tR) on diarylamino, carbazolyl and benzocarbazolyl includes examples in which some or all of the hydrogen atoms on the aryl ring or benzene ring in these groups are substituted with the group of formula (tR).

[0143] In the structure consisting of one or more structural units represented by formula (1), the substituent on the aryl ring or heteroaryl ring may be a substituent represented by the following formula (A20). [ka]

[0144] The substituent represented by formula (A20) is bonded to two adjacent atoms on 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, an optionally substituted aryl, an optionally substituted alkyl, or an optionally substituted cycloalkyl, and the two R's may be bonded to each other to form a ring, and at least one of the R's of the >NR and the >Si(-R)2 may be bonded to the aryl ring or heteroaryl ring via a linking group or a single bond. r is an integer from 1 to 4; R A are each independently hydrogen, substituted or unsubstituted alkyl, or substituted or unsubstituted cycloalkyl, and any R A is any other R A and may be bonded to each other via a linking group or a single bond.

[0145] Examples of the above substituent include any of the following substituents. [ka]

[0146] In each formula, * may be bonded to two or three consecutive (adjacent) atoms on any aryl or heteroaryl ring.

[0147] <Cycloalkane condensation> At least one selected from the group consisting of aryl rings and heteroaryl rings in the polycyclic aromatic compound having a structure consisting of one or more structural units represented by formula (1) may be condensed with at least one cycloalkane.

[0148] The cycloalkane may be a cycloalkane having 3 to 24 carbon atoms. In this case, at least one hydrogen atom in the cycloalkane may be substituted with an aryl having 6 to 30 carbon atoms, a heteroaryl having 2 to 30 carbon atoms, an alkyl having 1 to 24 carbon atoms, or a cycloalkyl having 3 to 24 carbon atoms, and at least one -CH2- group in the cycloalkane may be replaced with -O-.

[0149] 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.

[0150] 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.

[0151] Specific examples of the cycloalkane include cyclopropane, cyclobutane, cyclopentane, cyclohexane, cycloheptane, cyclooctane, cyclononane, cyclodecane, norbornane (bicyclo[2.2.1]heptane), bicyclo[1.1.0]butane, bicyclo[1.1.1]pentane, bicyclo[2.1.0]pentane, bicyclo[2.1.1]hexane, bicyclo[3.1.0]hexane, bicyclo[2.2.2]octane, adamantane, diamantane, decahydronaphthalene, and decahydroazulene, as well as alkyl (particularly methyl)-substituted, halogen (particularly fluorine)-substituted, and deuterium-substituted derivatives of these compounds having 1 to 5 carbon atoms.

[0152] Among the above examples, for example, as shown in the structural formula below, a structure having at least one substituent on the α-carbon of the cycloalkane (in a cycloalkane fused to an aryl ring or heteroaryl ring, the carbon adjacent to the carbon at the condensation site) is preferred, a structure having two substituents on the α-carbon is more preferred, and a structure having two substituents on each of the two α-carbons (four substituents in total) is even more preferred. Examples of such substituents include alkyl (particularly methyl) having 1 to 5 carbon atoms, halogen (particularly fluorine), and deuterium. In particular, a structure in which a partial structure represented by the following formula (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.

[0153] [ka] In each of the formulas (B11) and (B12), * indicates the bonding position.

[0154] The number of cycloalkanes fused to one aryl ring or heteroaryl ring is preferably 1 to 3, more preferably 1 or 2, and even more preferably 1. For example, an example in which one or more cycloalkanes are fused to one benzene ring (phenyl) is shown below. * indicates the bonding position, and the position may be any carbon that constitutes the benzene ring but not the cycloalkane. Fused cycloalkanes such as those in formula (Cy-1-4) and formula (Cy-2-4) may also be fused together. The same applies when the fused ring (group) is an aryl ring or heteroaryl ring other than a benzene ring (phenyl), or when the fused cycloalkane is a cycloalkane other than cyclopentane or cyclohexane.

[0155] [ka]

[0156] At least one -CH2- in a cycloalkane may be replaced with -O-. For example, an example in which one or more -CH2- in a cycloalkane fused to a benzene ring (phenyl) are replaced with -O- is shown below. The same applies when the fused ring (group) is an aryl ring or heteroaryl ring other than a benzene ring (phenyl), or when the fused cycloalkane is a cycloalkane other than cyclopentane or cyclohexane.

[0157] [ka]

[0158] The cycloalkane may be substituted with at least one substituent, and this substituent may be any substituent 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 hydrogen atom is replaced with a halogen atom (e.g., fluorine) or deuterium. When substituted with cycloalkyl, the substitution may be in the form of a spiro structure. For example, an example in which a spiro structure is formed in a cycloalkane fused 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 substituting the skeletal structure of the compound when it is a phenyl.

[0159] [ka]

[0160] As a form of cycloalkane condensation, first, R in a polycyclic aromatic compound having a structure consisting of one or more structural units represented by formula (1) a1 ~R a3 , R b1 ~R b4 , or R c1 ~R c4The benzene ring to which R is attached is condensed with a cycloalkane. a1 ~R a3 , R b1 ~R b4 , and R c1 ~R c4 is a group containing an aryl ring or a heteroaryl ring, the aryl ring or the heteroaryl ring being condensed with a cycloalkane.

[0161] In another form of cycloalkane condensation, a polycyclic aromatic compound having a structure consisting of one or more structural units represented by formula (1) is, for example, R NX is an aryl fused with a cycloalkane >NR NX An example having the following structure is given.

[0162] Furthermore, by introducing a cycloalkane structure into a polycyclic aromatic compound having a structure consisting of one or more structural units represented by formula (1), further reductions in melting point and sublimation temperature can be expected. This means that sublimation purification, which is almost essential as a method for purifying materials for organic devices such as organic electroluminescence (EL) elements, which require high purity, can be performed at relatively low temperatures, thereby avoiding thermal decomposition of the materials. This also applies to the vacuum deposition process, which is an effective means for producing organic devices such as organic electroluminescence (EL) elements. Since the process can be performed at relatively low temperatures, thermal decomposition of the materials can be avoided, resulting in high-performance organic devices. Furthermore, the introduction of a cycloalkane structure improves solubility in organic solvents, making it possible to apply the compound to the fabrication of elements using a coating process. However, the present invention is not particularly limited to these principles.

[0163] <Replacement with heavy stable isotopes> Unless otherwise specified, each element in a polycyclic aromatic compound having a structure consisting of one or more structural units represented by formula (1) contains multiple naturally occurring isotopes in their natural abundance ratios. However, all or some of the elements in each structural formula may be present in amounts exceeding their natural abundance ratios (for example, 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 by replacing at least one boron with boron-11( 11 By replacing with B), it is possible to extend the life of an organic electroluminescent device that uses, as a dopant, a polycyclic aromatic compound having a structure consisting of one or more structural units represented by formula (1).

[0164] <Replacement with deuterium> All or a part of the hydrogen atoms in the polycyclic aromatic compound having a structure consisting of one or more structural units represented by formula (1) may be deuterium atoms.

[0165] For example, R in a polycyclic aromatic compound having a structure consisting of one or more structural units represented by formula (1) a1 ~R a3 , R b1 ~R b4 , or R c1 ~R c4In particular, hydrogen atoms in the aryl or heteroaryl may be replaced with deuterium atoms. From the viewpoint of durability, it is also preferable that all or some of the hydrogen atoms in the polycyclic aromatic compound having a structure consisting of one or more structural units represented by formula (1) are deuterated.

[0166] <Specific examples of polycyclic aromatic compounds> Further specific examples of polycyclic aromatic compounds having a structure consisting of one or more structural units represented by formula (1) include the following compounds.

[0167] [ka]

[0168] [ka]

[0169] [ka]

[0170] [ka]

[0171] [ka]

[0172] [ka]

[0173] [ka]

[0174] [ka]

[0175] [ka]

[0176] [ka]

[0177] [ka]

[0178] [ka]

[0179] [ka]

[0180] [ka]

[0181] [ka]

[0182] [ka] In the formula, Me is methyl, tBu is t-butyl, and D is deuterium.

[0183] <Method of producing polycyclic aromatic compounds> Polycyclic aromatic compounds having a structure consisting of one or more structural units represented by formula (1) are basically prepared by first reacting R a1 ~R a3 Benzene ring to which R is attached b1 ~Rb4 The benzene ring to which R is attached, and c1 ~R c4 The fused ring to which is bonded is referred to as a bonding group (X 1 or X 2 (a group containing R a1 ~R a3 Benzene ring to which R is attached b1 ~R b4 The benzene ring to which R is attached, and c1 ~R c4 The fused ring to which is bonded is a bonding group (Y 1 The final product can be produced by bonding the two groups together with a group containing the aryl group (second reaction). In the first reaction, for example, common reactions such as the Buchwald-Hartwig reaction, nucleophilic substitution reaction, and Goldberg amination can be used as amination reactions. In the second reaction, a tandem hetero-Friedel-Crafts reaction (sequential aromatic electrophilic substitution reaction, the same applies below) can be used. The desired compound can be produced by using a raw material with the desired fused ring somewhere in the reaction process or by adding a step to condense the ring.

[0184] [Production method via intermediate 1] The polycyclic aromatic compound of the present invention can be produced by a production method including the following steps. For each of the steps, reference can be made to the description in WO 2015 / 102118.

[0185] The following intermediate 1 is synthesized from a halogenated precursor, and X in the following intermediate 1 is obtained by using an organic alkali compound. 1 and X 2 a reaction step of metallating the halogen atom (Hal) between Y 1 Halides of Y 1 Aminated halides of Y 1 Alkoxylated compounds of Y 1 and Y are reacted with a reagent selected from the group consisting of aryl oxy compounds of the formula 1 and a reaction step of exchanging Y with a Bronsted base by successive electrophilic aromatic substitution reactions. 1 With R b1~R b4 The benzene ring to which R is attached c1 ~R c4 The reaction includes a reaction step of bonding the fused ring to which the halogen atom is bonded, as shown below. The halogen atom (Hal) in the formula may be any of F, Cl, Br, and I, and can be appropriately selected in consideration of the reactivity of the substrate.

[0186] [ka]

[0187] Metalating reagents used in the halogen-metal exchange reaction in the schemes explained so far include alkyllithiums such as methyllithium, n-butyllithium, sec-butyllithium, and t-butyllithium, isopropylmagnesium chloride, isopropylmagnesium bromide, phenylmagnesium chloride, phenylmagnesium bromide, and lithium chloride complexes of isopropylmagnesium chloride, known as turboGrignard reagents.

[0188] In addition to the reagents mentioned above, the metalation reagents used in the ortho-metalation reactions in the schemes described so far include organic alkali compounds such as lithium diisopropylamide, lithium tetramethylpiperidide, lithium hexamethyldisilazide, potassium hexamethyldisilazide, lithium chloride tetramethylpiperidinylmagnesium-lithium chloride complex, and lithium tri-n-butylmagnesium oxide.

[0189] Furthermore, when alkyllithium is used as the metalation reagent, additives that promote the reaction include N,N,N',N'-tetramethylethylenediamine, 1,4-diazabicyclo[2.2.2]octane, and N,N-dimethylpropyleneurea.

[0190] Lewis acids used in the schemes described above 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. These Lewis acids can also be used in solid-supported forms.

[0191] Examples of Bronsted acids used in the schemes described so far include p-toluenesulfonic acid, methanesulfonic acid, trifluoromethanesulfonic acid, fluorosulfonic acid, carborane acid, trifluoroacetic acid, (trifluoromethanesulfonyl)imide, tris(trifluoromethanesulfonyl)methane, hydrogen chloride, hydrogen bromide, and hydrogen fluoride. Examples of solid Bronsted acids include Amberlyst (Dow Chemical), Nafion (DuPont), zeolite, and Teikacure (Teika Corporation).

[0192] In addition, examples of amines that may be added in the schemes described above include diisopropylethylamine, triethylamine, tributylamine, 1,4-diazabicyclo[2.2.2]octane, N,N-dimethyl-p-toluidine, N,N-dimethylaniline, pyridine, 2,6-lutidine, and 2,6-di-t-butylamine.

[0193] In addition, solvents used in the schemes described so far include o-dichlorobenzene, chlorobenzene, toluene, benzene, methylene chloride, chloroform, dichloroethylene, benzotrifluoride, decalin, cyclohexane, hexane, heptane, 1,2,4-trimethylbenzene, xylene, diphenyl ether, anisole, cyclopentyl methyl ether, tetrahydrofuran, dioxane, and methyl t-butyl ether.

[0194] Here, Y 1 However, by changing the raw materials appropriately, it is possible to obtain Y. 1 Compounds in which is P, P=O, P=S, Al, Ga, As, Si—R, or Ge—R can also be synthesized.

[0195] In the above scheme, a Bronsted base or Lewis acid may be used to promote the tandem hetero-Friedel-Crafts reaction. 1 trifluoride, Y 1 trichloride, Y 1 tribromide, Y 1 Y triiodide etc. 1 When using halides of Y, acids such as hydrogen fluoride, hydrogen chloride, hydrogen bromide, and hydrogen iodide are generated as the aromatic electrophilic substitution reaction proceeds, so the use of a Brønsted base to capture the acid is effective. 1 Aminated halides of Y 1 When an alkoxylated compound of the formula (I) is used, an amine or alcohol is produced as the aromatic electrophilic substitution reaction proceeds, so in many cases it is not necessary to use a Bronsted base. However, since the amino and alkoxy groups have low elimination ability, it is effective to use a Lewis acid to promote their elimination.

[0196] The polycyclic aromatic compounds of the present invention also include compounds in which at least some of the hydrogen atoms have been replaced with deuterium atoms or compounds in which the hydrogen atoms have been replaced with various substituents. Such compounds can be synthesized in the same manner as described above by using raw materials in which the desired positions have been deuterated or derivatized.

[0197] <2. Organic Devices> The polycyclic aromatic compound of the present invention can be used as a material for organic devices, such as organic electroluminescent devices, organic field-effect transistors, and organic thin-film solar cells.

[0198] The polycyclic aromatic compound and its multimer according to the present invention can be used as a material for an organic device. Examples of the organic device include an organic electroluminescent device, an organic field-effect transistor, and an organic thin-film solar cell, and the like, but the organic electroluminescent device is preferred. The polycyclic aromatic compound according to the present invention is preferably a material for an organic electroluminescent device, more preferably a material for an emitting layer (light-emitting material), and most preferably a dopant material for the emitting layer.

[0199] <2-1. Organic electroluminescent devices> <2-1-1. Structure of organic electroluminescent device> FIG. 1 is a schematic cross-sectional view showing an example of an organic EL element. The organic EL device 100 shown in FIG. 1 includes a substrate 101, an anode 102 provided on the substrate 101, a hole injection layer 103 provided on the anode 102, a hole transport layer 104 provided on the hole injection layer 103, an emitting layer 105 provided on the hole transport layer 104, an electron transport layer 106 provided on the emitting layer 105, an electron injection layer 107 provided on the electron transport layer 106, and a cathode 108 provided on the electron injection layer 107.

[0200] 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.

[0201] Not all of the above layers are essential, and the minimum structural unit is a configuration consisting of an anode 102, an emitting layer 105, and a cathode 108. The hole injection layer 103, the hole transport layer 104, the electron transport layer 106, and the electron injection layer 107 are layers that may be optionally provided. Furthermore, each of the above layers may consist of a single layer or multiple layers.

[0202] The layers constituting the organic EL element may be configured as follows: "substrate / anode / hole injection layer / hole transport layer / light-emitting layer / electron transport layer / electron injection layer / cathode" as described above, as well as "substrate / anode / hole transport layer / light-emitting layer / electron transport layer / electron injection layer / cathode", "substrate / anode / hole injection layer / light-emitting layer / electron transport layer / electron injection layer / cathode", "substrate / anode / hole injection layer / hole transport layer / light-emitting ... transport The configuration may be, for example, "substrate / anode / light-emitting layer / electron transport layer / electron injection layer / cathode," "substrate / anode / hole transport layer / light-emitting layer / electron injection layer / cathode," "substrate / anode / hole transport layer / light-emitting layer / electron injection layer / cathode," "substrate / anode / hole transport layer / light-emitting layer / electron transport layer / cathode," "substrate / anode / hole injection layer / light-emitting layer / electron injection layer / cathode," "substrate / anode / hole injection layer / light-emitting layer / electron transport layer / cathode," "substrate / anode / light-emitting layer / electron transport layer / cathode," or "substrate / anode / light-emitting layer / electron injection layer / cathode."

[0203] <2-1-2. Light-emitting layer in organic electroluminescent device> The polycyclic aromatic compound of the present invention is preferably used as a material for forming one or more organic layers in an organic electroluminescent device, and more preferably as a material for forming an emissive layer. The emissive layer 105 is a layer that emits light by recombining holes injected from the anode 102 and electrons injected from the cathode 108 between electrodes to which an electric field is applied. The material for the emissive layer 105 may be any compound (emissive compound) that is excited and emits light upon recombination of holes and electrons. It is preferable that the compound be capable of forming a stable thin film and exhibit strong luminescence (fluorescence) efficiency in the solid state. The polycyclic aromatic compound of the present invention can be used as a material for the emissive layer, and may be used as a dopant material or a host material. However, it is preferably used as a material for the emissive layer, and more preferably as a dopant material.

[0204] In addition, there are cases where the dopant is used in combination with an assisting dopant and an emitting dopant, but in this specification, when the term "dopant" is simply used, it refers to an emitting dopant when no assisting dopant is used.

[0205] Polycyclic aromatic compounds containing a structural unit represented by formula (1) can be used as emitting dopants in TTF devices that utilize the phenomenon of triplet-triplet fusion (TTF), in which singlet excitons are generated from multiple triplet excitons.

[0206] Furthermore, polycyclic aromatic compounds containing the structural unit represented by formula (1) can be used as "thermally activated delayed fluorescent materials" as emitting dopants in TADF devices. By reducing the energy difference between the lowest excited singlet state and the lowest excited triplet state, "thermally activated delayed fluorescent materials" efficiently induce reverse intersystem crossing from the lowest excited triplet state, which normally has a low transition probability, to the lowest excited singlet state, resulting in emission from the singlet state (thermally activated delayed fluorescent material, TADF). In conventional fluorescent emission, 75% of the triplet excitons generated by current excitation undergo a thermal deactivation pathway and cannot be extracted as fluorescence. In contrast, TADF allows all excitons to be utilized for fluorescent emission, enabling the realization of highly efficient organic electroluminescent devices.

[0207] The light-emitting layer may be a single layer or multiple layers, each formed from materials for the light-emitting layer (host material, dopant material). The host material and the dopant material may each be one type or a combination of multiple types. The dopant material may be contained entirely or partially in the host material. As a doping method, the dopant material can be formed by co-evaporation with the host material, or it may be mixed with the host material in advance and then vapor-deposited simultaneously.

[0208] The amount of the host material used varies depending on the type of host material and may be determined according to the properties of the host material. The amount of the host material used is preferably 50 to 99.999% by mass, more preferably 80 to 99.95% by mass, and even more preferably 90 to 99.9% by mass of the total mass of the materials for the light-emitting layer.

[0209] The amount of dopant material used varies depending on the type of dopant material and may be determined according to the properties of the dopant material. The amount of dopant material used is preferably 0.001 to 50% by mass, more preferably 0.05 to 20% by mass, and even more preferably 0.1 to 10% by mass, of the total mass of the materials for the light-emitting layer. The above range is preferable in that, for example, concentration quenching can be prevented.

[0210] <Dopant materials> As the dopant material, the polycyclic aromatic compound of the present invention can be preferably used. The dopant material may be a combination of compounds. When a plurality of dopants are combined, specific examples of dopants to be combined with the compound of the present invention are shown below.

[0211] [ka]

[0212] [ka]

[0213] [ka]

[0214] [ka]

[0215] <Host material> Examples of the host material include fused ring derivatives of anthracene, pyrene, dibenzochrysene, fluorene, etc., which have long been known as light emitters, bisstyryl derivatives such as bisstyrylanthracene derivatives and distyrylbenzene derivatives, tetraphenylbutadiene derivatives, cyclopentadiene derivatives, fluorene derivatives, benzofluorene derivatives, etc. Furthermore, as the host material, for example, a compound represented by any of the following formulas (H1), (H2), and (H3) can be used.

[0216] 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 an 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.

[0217] [Compounds represented by any one of formulas (H1), (H2) and (H3)] [ka]

[0218] In formulas (H1), (H2) and (H3), L 1 is a single bond or a divalent group containing at least an arylene or heteroarylene group. 1 L may be a single bond, or a divalent group formed by linking any two of these groups together via -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, and 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 formulas 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.

[0219] 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.

[0220] [ka] (mCP)

[0221] [ka]

[0222] [ka]

[0223] [ka]

[0224] [Anthracene compounds] Examples of the anthracene compound as a host include a compound represented by formula (3-H) and a compound represented by formula (3-H2). [ka]

[0225] 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; and all of X and Ar 4 cannot simultaneously become hydrogen. At least one hydrogen atom in the compound represented by formula (3-H) may be substituted with halogen, cyano, deuterium, or an optionally substituted heteroaryl.

[0226] Furthermore, a multimer (preferably a dimer) may be formed using the structure represented by formula (3-H) as a unit structure. In this case, for example, the unit structures represented by formula (3-H) may be bonded to each other via X, where X may be a single bond, an arylene (such as phenylene, biphenylene, or naphthylene), or a heteroarylene (a divalent group such as a pyridine ring, a dibenzofuran ring, a dibenzothiophene ring, a carbazole ring, a benzocarbazole ring, or a phenyl-substituted carbazole ring).

[0227] Preferred embodiments of the above anthracene compounds are described below: The symbols in the following structures are defined as above. [ka]

[0228] In formula (3-H), X's are 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, no two X's are simultaneously a group represented by formula (3-X3). More preferably, no two X's are simultaneously a group represented by formula (3-X2).

[0229] Furthermore, a multimer (preferably a dimer) may be formed using the structure represented by formula (3-H) as a unit structure. In this case, for example, the unit structures represented by formula (3-H) may be bonded to each other via X, where X may be a single bond, an arylene (such as phenylene, biphenylene, or naphthylene), or a heteroarylene (a divalent group such as a pyridine ring, a dibenzofuran ring, a dibenzothiophene ring, a carbazole ring, a benzocarbazole ring, or a phenyl-substituted carbazole ring).

[0230] The naphthylene moieties in formula (3-X1) and formula (3-X2) may be fused with one benzene ring. The fused structures are as follows: [ka]

[0231] Ar 1 and Ar 2 are 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 *.

[0232] 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.

[0233] Also, Ar 3 may have a substituent, and Ar 3 At least one hydrogen atom in the formula (A) may be further substituted with an alkyl group having 1 to 4 carbon atoms, a cycloalkyl group having 5 to 10 carbon atoms, phenyl, biphenylyl, terphenylyl, naphthyl, phenanthryl, fluorenyl, chrysenyl, triphenylenyl, pyrenyl, or a group represented by formula (A) (including carbazolyl and phenyl-substituted carbazolyl). 3 When the substituent of is a group represented by formula (A), the group represented by formula (A) is Ar in formula (3-X3) at *.3 and combine.

[0234] Ar 4 are each independently hydrogen, phenyl, biphenylyl, terphenylyl, naphthyl, or silyl substituted with alkyl having 1 to 4 carbon atoms (such as methyl, ethyl, and t-butyl) and / or cycloalkyl having 5 to 10 carbon atoms.

[0235] Furthermore, hydrogen atoms 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 atom in the compound represented by formula (3-H) at the *.

[0236] The group represented by formula (A) is one of the substituents that the anthracene compound represented by formula (3-H) may have. [ka]

[0237] In formula (A), Y is -O-, -S-, >C(-R 29-1 )2, 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 28 adjacent 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—.

[0238] R 21 ~R 28 The "substituted amino" in the "optionally substituted amino" includes diarylamino, diheteroarylamino, arylheteroarylamino, and the like.

[0239] Y as 'NR' 29 "R" 29 is hydrogen or optionally substituted aryl.

[0240] Y as ">C(-R 29-1 )2" 29-1 are each independently hydrogen, alkyl, or optionally substituted aryl. 29-1 may be bonded to each other to form a hydrocarbon ring or an aryl ring.

[0241] 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 formula (A-1) below does not form a ring, and examples of the group represented by formulas (A-2) to (A-14) below include groups represented by formulas (A-1) to (A-14). 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 (the two aryls may be bonded to each other via a linking group), substituted amino, diheteroaryl-substituted amino, arylheteroaryl-substituted amino, halogen, hydroxy, or cyano.

[0242] [ka]

[0243] Examples of rings formed by bonding adjacent groups to each other include hydrocarbon rings such as cyclohexane rings, and examples of aryl and heteroaryl rings include the above-mentioned R 21 ~R 28 These rings are formed so as to be fused with one or two benzene rings in formula (A-1).

[0244] 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. That is, 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" 29 Any position in the 29 " in N(R 29 The same applies to the groups represented by any of formulae (A-1) to (A-14).

[0245] Examples of the group represented by formula (A) include groups represented by any of formulas (A-1) to (A-14), preferably groups represented by any of formulas (A-1) to (A-5) and formulas (A-12) to (A-14), more preferably groups represented by any of formulas (A-1) to (A-4), still more preferably groups represented by any of formulas (A-1), (A-3) and (A-4), and particularly preferably groups represented by formula (A-1).

[0246] Examples of the group represented by formula (A) include the following groups: In the formula, Y and * are defined as above. [ka]

[0247] [ka]

[0248] 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 The preferred form is a combination of any one of the following:

[0249] The group represented by formula (B) is one of the substituents that the anthracene compound represented by formula (3-H) may have. [ka]

[0250] In formula (B), Y b -O-, -S-, >C(-R 42 )2 or >NR 41 and R 31 ~R 40 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 31 ~R 40 adjacent groups among R may be bonded to each other to form a hydrocarbon ring, an aryl ring, or a heteroaryl ring; 41 is hydrogen or optionally substituted aryl. Y in formula (B) b is preferably —O—.

[0251] Y b as ">C(-R 41 )2" 41are each independently hydrogen, alkyl, or optionally substituted aryl. 41 may be bonded to each other to form a hydrocarbon ring or an aryl ring.

[0252] In formula (B), R 31 ~R 40 Examples of rings formed by bonding two adjacent groups include hydrocarbon rings such as cyclohexane rings, and examples of aryl and heteroaryl rings include the above-mentioned R 31 ~R 40 These rings are formed so as to be fused with one or two benzene rings in formula (A-1).

[0253] The group represented by formula (B) is a group obtained by removing one hydrogen atom from any position of formula (B), and * indicates the position. That is, the group represented by formula (B) may have any position as a bonding position. For example, any carbon atom on the two benzene rings in the structure of formula (B), R 31 ~R 40 an atom on any ring formed by bonding adjacent groups to each other, or Y in the structure of formula (B) b as "NR 41 "R" 41 Any position in the 41 " in N(R 41 It can be a group that bonds directly to the

[0254] Examples of the group represented by formula (B) include the following groups: b and * have the same definition as above.

[0255] [ka]

[0256] All or part of the hydrogen atoms in the chemical structure of the anthracene compound represented by formula (3-H) may be deuterium atoms.

[0257] The anthracene compound as the host may be, for example, a compound represented by the following formula (3-H2). [ka]

[0258] In formula (3-H2), Ar c is an optionally substituted aryl or an optionally substituted heteroaryl, and R c is hydrogen, alkyl, or cycloalkyl, and Ar 11 , Ar 12 , Ar 13 , Ar 14 , Ar 15 , Ar 16 , Ar 17 , and Ar 18 are each independently hydrogen, an optionally substituted aryl, an optionally substituted heteroaryl, an optionally substituted diarylamino (two aryls may be bonded to each other via a linking group), an optionally substituted diheteroarylamino (two heteroaryls may be bonded to each other via a linking group), an optionally substituted arylheteroarylamino (an aryl and a heteroaryl may be bonded to each other via a linking group), an optionally substituted alkyl, an optionally substituted cycloalkyl, an optionally substituted alkenyl, an optionally substituted alkoxy, an optionally substituted aryloxy, an optionally substituted arylthio, or an optionally substituted silyl, and at least one hydrogen in the compound represented by Formula (3-H2) may be substituted with halogen, cyano, or deuterium.

[0259] The "optionally substituted aryl" is also preferably a group represented by any one of the following formulae (3-H2-X1) to (3-H2-X8).

[0260] [ka]

[0261] In formulae (3-H2-X1) to (3-H2-X8), * indicates a bonding 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 description of formula (3-H2), the group represented by formula (A) is the same as that described in the anthracene compound represented by formula (3-H).

[0262] In the formulas (3-H2-X4) to (3-H2-X8), Ar 24 , Ar 25 , Ar 26 , Ar 27 , Ar 28 , Ar 29 , and Ar 30 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 alkyl having 1 to 6 carbon atoms (preferably methyl or t-butyl).

[0263] Furthermore, preferred examples of the "optionally substituted aryl" include terphenylyl (particularly m-terphenyl-5'-yl) optionally substituted with one or more substituents selected from the group consisting of phenyl, biphenylyl, terphenylyl, naphthyl, phenanthryl, fluorenyl, chrysenyl, triphenylenyl, pyrenyl, and groups represented by formula (A).

[0264] The "optionally substituted heteroaryl" also includes a group represented by formula (A). Other specific examples of the "optionally substituted aryl" and "optionally substituted heteroaryl" include dibenzofuryl, naphthobenzofuryl, phenyl-substituted dibenzofuryl, etc.

[0265] At least one hydrogen atom in the compound represented by formula (3-H2) may be substituted with a halogen atom, cyano atom, or deuterium atom. In this case, "halogen" includes fluorine, chlorine, bromine, and iodine. In particular, a compound in which all hydrogen atoms in the compound represented by formula (3-H2) are substituted with deuterium atoms is preferred.

[0266] 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 18 It is preferable that at least two of the substituents be optionally substituted aryl or optionally substituted heteroaryl. That is, the anthracene compound represented by formula (3-H2) preferably has a structure in which at least three substituents selected from the group consisting of optionally substituted aryl and optionally substituted heteroaryl are bonded to the anthracene ring.

[0267] The anthracene compound represented by formula (3-H2) is Ar 11 ~Ar 18It is more preferred that two of the groups 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 preferred 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.

[0268] 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.

[0269] Furthermore, in formula (3-H2), R c is hydrogen and Ar 11 ~Ar 18 It is preferred that any six of these are hydrogen.

[0270] 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]

[0271] In 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 18Each of the ' is 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). When both hydrogen atoms of the methylenes in the fluorenyl and benzofluorenyl are substituted with phenyl, these phenyls may be bonded to each other via a single bond. Ar c ', Ar 11 ', Ar 12 ', Ar 13 ', Ar 14 ', Ar 15 ', Ar 17 ', and Ar 18 The carbon atoms of the anthracene ring to which ' is not attached may have methyl or t-butyl attached instead of hydrogen.

[0272] Ar c ', Ar 11 ', Ar 12 ', Ar 13 ', Ar 14 ', Ar 15 ', Ar 17 ', and Ar 18 When each of "3-H2-X1" and "3-H2-X8" 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).

[0273] Ar c ', Ar 11 ', Ar 12 ', Ar 13 ', Ar 14 ', Ar 15 ', Ar 17 ', and Ar 18It is more preferable that each of the ' 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).

[0274] 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. Deuterated forms are preferred, and a form in which all anthracene rings are deuterated or a form in which all hydrogen atoms are deuterated is preferred.

[0275] Particularly preferred anthracene compounds represented by formula (3-H2) include anthracene compounds represented by the following formula (3-H2-Aa). [ka]

[0276] 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). When both hydrogen atoms of the methylenes in the fluorenyl and benzofluorenyl are substituted with phenyl, these phenyls may be bonded to each other via 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 in place 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.

[0277] In formula (3-H2-Aa), Ar c ', Ar 14 ', and Ar 15 It is preferable that each of the ' is 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).

[0278] In the compound represented by formula (3-H2-Aa), at least the carbon atom at the 10-position of the anthracene ring (Ar cIt is preferable that the hydrogen bonded to the carbon atom (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 Ar 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 also be deuterium, and it is also preferred that all hydrogens in formula (3-H2-Ab) are deuterium.

[0279] [ka]

[0280] 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). The hydrogen atoms in these formulae may be partially or completely substituted with deuterium, and particularly preferred forms of deuterium substitution 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 may be either an optionally linked aryl or alkyl, and R 29 is, for example, phenyl, R 30 For example, when Y is O, the formula (3-131-Y) becomes the formula (3-131-O), and when Y is -S- or >NR 29 In the case of (3-131-S) or (3-131-N), respectively.

[0281]

change

[0282]

change

[0283]

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[0284]

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[0285]

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[0286]

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[0287]

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[0288]

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[0289]

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[0290]

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[0291]

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[0292] [ka]

[0293] [ka]

[0294] [ka]

[0295] [ka]

[0296] [ka]

[0297] [ka]

[0298] [ka]

[0299] [ka]

[0300] [ka] JPEG2026020108000107.jpg172170In the above formula, D is deuterium.

[0301] Among these compounds, the following are also found: (3-131-Y) to (3-134-Y), (3-138-Y), (3-140-Y) to (3-143-Y), (3-150-Y), (3-153-Y) to (3-156-Y), (3-166-Y), (3-168-Y), (3-173-Y), (3-177-Y), (3-180-Y) to (3-183-N), (3-185-Y), (3-190-Y), (3-223-Y), (3-241- Y), formula (3-250-Y), formula (3-252-Y) to formula (3-254-Y), formula (3-270-Y) to formula (3-284-Y), formula (3-501), formula (3-507), formula (3-508), formula (3-509), formula (3-513), formula (3-514), formula (3-519), formula (3-521), formula (3-538) to formula (3-547), or formula (3-600) to formula (3-605), and formula (3-606-Y) to formula (3-626-Y) are preferred. In addition, Y is -O- or >NR 29 is preferred, and -O- is more preferred. b is preferably -O-, and deuterium-substituted forms are also preferred.

[0302] 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 can be produced by applying Suzuki coupling, Negishi coupling, or other known coupling reactions using a compound having a reactive group in a partial structure such as the structure of formula (A) as a starting material. Examples of reactive groups in these reactive compounds include halogens and boronic acids. For specific production methods, reference can be made to the synthesis methods described in paragraphs

[0089] to

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

[0303] [Fluorene compounds] The compound represented by formula (4-H) basically functions as a host. [ka]

[0304] 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 (two aryls may be bonded to each other via a linking group), diheteroarylamino (two heteroaryls may be bonded to each other via a linking group), arylheteroarylamino (aryls and heteroaryls may be bonded to each other via a linking group), alkyl, cycloalkyl, alkenyl, alkoxy, or aryloxy, in which at least one hydrogen may be substituted with 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 atom in the formed ring may be substituted with an aryl, heteroaryl (the heteroaryl may be bonded to the formed ring via a single bond or a linking group), diarylamino (two aryls may be bonded to each other via a linking group), diheteroarylamino (two heteroaryls may be bonded to each other via a linking group), arylheteroarylamino (the aryl and heteroaryl may be bonded to each other via a linking group), alkyl, cycloalkyl, alkenyl, alkoxy, or aryloxy, and at least one hydrogen atom in these may be substituted with an aryl, heteroaryl, alkyl, or cycloalkyl; and at least one hydrogen atom in the compound represented by formula (4-H) may be substituted with a halogen atom, cyano, or deuterium.

[0305] 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).

[0306] [ka]

[0307] 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.

[0308] 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 and the heteroaryl in formula (4-H) may not only be bonded directly, but also may be bonded via a linking group. Examples of such linking groups include phenylene, biphenylene, naphthylene, anthracenylene, methylene, ethylene, -OCH2CH2-, -CH2CHO-, or -OCH2CHO-.

[0309] Furthermore, 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 10may 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 containing 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 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.

[0310] The compound represented by formula (4-H) is preferably a compound represented by the following formula (4-H-1), formula (4-H-2), or formula (4-H-3), and in formula (4-H), R 1 and R 2 In formula (4-H), R 3 and R 4 In formula (4-H), R 1 From R 8 is a compound in which none of the above is bound.

[0311] [ka]

[0312] R in formula (4-H-1), formula (4-H-2) and formula (4-H-3) 1 From R 10 The definition of R in formula (4-H) corresponds to 1 From R 10 and 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

[0313] 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), where R 9 and R 10 is a compound in which a spiro-fluorene ring is formed by bonding.

[0314] [ka]

[0315] 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 and 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) 11 From R 14 is the same as

[0316] In addition, all or part of the hydrogen atoms in the compound represented by formula (4-H) may be substituted with halogen, cyano, or deuterium.

[0317] More specific examples of the fluorene compound as the host of the present invention include compounds represented by the following structural formulas. [ka]

[0318] [Pyrene compounds] The pyrene compound as the host is, for example, a compound represented by the following formula (6-H). [ka]

[0319] In the above formula (6-H), R 1 From R 11 are each independently hydrogen, aryl, heteroaryl, diarylamino, diheteroarylamino, arylheteroarylamino, alkyl, cycloalkyl, alkenyl, alkoxy, or aryloxy, in which at least one hydrogen may be replaced by aryl, heteroaryl, alkyl, or cycloalkyl; and R 1 From R 11 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 (6-H) may be independently substituted with halogen, cyano, or deuterium. Examples of pyrene compounds include the pyrene compounds described in WO 2021 / 210304, WO 2021 / 210305, or WO 2021 / 049659.

[0320] Specific examples of the pyrene compound include the following compounds. [ka]

[0321] [ka]

[0322] [ka]

[0323] [ka]

[0324] [Dibenzochrysene compounds] The dibenzochrysene compound as the host is, for example, a compound represented by the following formula (5-H). [ka]

[0325] 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 substituted with 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, heteroaryl (the heteroaryl may be bonded to the formed ring via a single bond or a linking group), diarylamino, diheteroarylamino, arylheteroarylamino, alkyl, cycloalkyl, alkenyl, alkoxy, or aryloxy, and at least one hydrogen atom in these may be substituted with an aryl, heteroaryl, alkyl, or cycloalkyl. At least one hydrogen atom in the compound represented by formula (5-H) may be substituted with a halogen atom, cyano, or deuterium.

[0326] Examples of alkenyl in the definition of formula (5-H) 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, still more preferably alkenyl having 2 to 6 carbon atoms, and particularly preferably alkenyl having 2 to 4 carbon atoms. Preferred alkenyls include 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, and 5-hexenyl.

[0327] 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).

[0328] [ka]

[0329] 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.

[0330] 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 not only directly but also via a linking group. Examples of the linking group include phenylene, biphenylene, naphthylene, anthracenylene, methylene, ethylene, -OCH2CH2-, -CH2CHO-, and -OCH2CHO-.

[0331] 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 such a 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.

[0332] The compound represented by formula (5-H) is more preferably R 1 , R 2 , R 4 , R 5 , R 7 , R 8 , R 9 , R 10 , R 12 , R 13 , R 15 and R 16 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 others (i.e., other than the position where the monovalent group having the above structure is substituted) are 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.

[0333] Furthermore, 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 group, at least one hydrogen atom in the structure is selected from the group represented by R 1 From R 16 may be bonded to any one of the following to form a single bond.

[0334] More specific examples of the dibenzochrysene compound as the host of the present invention include compounds represented by the following structural formulas. [ka]

[0335] [ka]

[0336] [Fluoranthene compounds] The fluoranthene compound as the host is, for example, a compound represented by the following formula (7-H). [ka] In the above formula (7-H), R 1 From R 10 are each independently hydrogen, aryl, heteroaryl, diarylamino, diheteroarylamino, arylheteroarylamino, alkyl, cycloalkyl, alkenyl, alkoxy, or aryloxy, in which at least one hydrogen may be replaced by aryl, heteroaryl, alkyl, or cycloalkyl; and R 1 From R 10 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 (7-H) may be independently substituted with halogen, cyano, or deuterium.

[0337] The fluoranthene compound represented by formula (7-H) is also preferably the compound represented by the following formula (7-H-1). [ka]

[0338] In the above formula (7-H-1), R 1 From R 12 The definition of is R in formula (7-H). 1 From R 10 is the same as, and At least one hydrogen atom in the compound represented by formula (7-H-1) may be independently substituted with halogen, cyano, or deuterium.

[0339] More specific examples of the fluoranthene compound as the host of the present invention include compounds represented by the following structural formulas.

[0340] [ka]

[0341] [Benzanthracene compounds] The benzanthracene compound as the host is, for example, a compound represented by the following formula (8-H). [ka] In the above formula (8-H), R 1 From R 12 are each independently hydrogen, aryl, heteroaryl, diarylamino, diheteroarylamino, arylheteroarylamino, alkyl, cycloalkyl, alkenyl, alkoxy, or aryloxy, in which at least one hydrogen may be replaced by aryl, heteroaryl, alkyl, or cycloalkyl; and R 1 From R 12 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 (8-H) may be independently substituted with halogen, cyano, or deuterium.

[0342] More specific examples of the benzanthracene compound as the host of the present invention include compounds represented by the following structural formulas.

[0343] [ka]

[0344] [ka]

[0345] The above-mentioned light-emitting layer materials (host materials and dopant materials) can also be used as light-emitting layer materials in the form of polymer compounds obtained by polymerizing a reactive compound substituted with a reactive substituent as a monomer, or a crosslinked polymer thereof, or a pendant-type polymer compound obtained by reacting a main-chain polymer with the reactive compound, or a crosslinked pendant-type polymer thereof. Regarding the reactive substituent in this case, the same explanation as for the polycyclic aromatic compound represented by formula (1) can be cited.

[0346] <Light-emitting layer containing an assisting dopant and an emitting dopant> The light-emitting layer in the organic electroluminescent device may contain a host compound as a first component, an assisting dopant (compound) as a second component, and an emitting dopant (compound) as a third component. The polycyclic aromatic compound of the present invention is also preferably used as the emitting dopant. A thermally activated delayed phosphor can be used as the assisting dopant (compound).

[0347] In the following description, an organic electroluminescent device using a thermally activated delayed fluorescent substance as an assisting dopant may be referred to as a "TAF device" (TADF Assisting Fluorescence device). The "host compound" in a TAF device refers to 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 substance as the second component and the emitting dopant as the third component.

[0348] The term "thermally activated delayed fluorescent substance" refers to a compound that can absorb thermal energy to undergo reverse intersystem crossing from the lowest excited triplet state to the lowest excited singlet state, and then radiatively deactivate from the lowest excited singlet state to emit delayed fluorescence. However, the term "thermally activated delayed fluorescent substance" also includes compounds that undergo a higher-order triplet state during the excitation process from the lowest excited triplet state to the lowest excited singlet state. Examples include a paper by Monkman et al. of Durham University (NATURE COMMUNICATIONS,7:13680,DOI: 10.1038 / ncomms13680), a paper by Hosokai et al. of the National Institute of Advanced Industrial Science and Technology (Hosokai et al., Sci. Adv. 2017;3: e1603282), a paper by Sato et al. of Kyoto University (Scientific Reports,7:4820,DOI:10.1038 / s41598-017-05007-7), and an academic presentation by Sato et al., also of Kyoto University (98th Annual Meeting of the Chemical Society of Japan, presentation number: 2I4-15, Mechanism of highly efficient light emission in organic electroluminescence using DABNA as the emissive molecule, Kyoto University Graduate School of Engineering). In the present invention, when a sample containing a target compound is measured for its fluorescence lifetime at 300 K, if a slow fluorescent component is observed, the target compound is determined to be a "thermally activated delayed fluorescent substance." Here, a slow fluorescent component refers to a component with a fluorescence lifetime of 0.1 μsec or longer. The fluorescence lifetime can be measured using, for example, a fluorescence lifetime measurement device (manufactured by Hamamatsu Photonics, C11367-01).

[0349] The polycyclic aromatic compound of the present invention can function as an emitting dopant, and the "thermally activated delayed fluorescent substance" can function as an assisting dopant that assists the emission of the polycyclic aromatic compound of the present invention.

[0350] In this embodiment, known host compounds can be used, such as compounds having at least one of a carbazole ring and a furan ring. Among them, it is preferable to use a compound having at least one of a furanyl group and a carbazolyl group bonded to at least one of an arylene group and a heteroarylene group. Specific examples include compounds represented by formula (H1), (H2), and (H3), particularly mCP and mCBP.

[0351] The lowest excited triplet energy level E(1,T,Sh), determined from the shoulder on the short-wavelength side of the peak of the phosphorescence spectrum of the host compound, is preferably higher than the 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 TADF generation without inhibiting it. Specifically, the lowest excited triplet energy level E(1,T,Sh) of the host compound is preferably 0.01 eV or higher, more preferably 0.03 eV or higher, and even more preferably 0.1 eV or higher, relative to E(2,T,Sh) and E(3,T,Sh). A TADF-active compound may also be used as the host compound.

[0352] The host compound may be, for example, a compound represented by any one of the above formulas (H1), (H2) and (H3).

[0353] <Thermally activated delayed phosphor (assisting dopant)> 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. Herein, the term "electron-donating substituent" (donor) refers to a substituent and partial structure in which the HOMO is localized in the thermally activated delayed phosphor molecule, and the term "electron-accepting substituent" (acceptor) refers to a substituent and partial structure in which the LUMO is localized in the thermally activated delayed phosphor molecule.

[0354] Generally, thermally activated delayed phosphors using donors or acceptors have large spin-orbit coupling (SOC) due to their structure, small exchange interaction between the HOMO and LUMO, and small ΔE(ST), resulting in a very fast reverse intersystem crossing rate. By using the polycyclic aromatic compound of the present invention as an emitting dopant and a thermally activated delayed phosphor (TADF material) as an assisting dopant, a device can be obtained 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, adjacent layers, or other nearby layers.

[0355] As the thermally activated delayed phosphor in the TAF element, for example, a compound in which a donor and an acceptor are bonded directly or via a spacer can be used.As the electron donating group (donor structure) and electron accepting group (acceptor structure) used in the thermally activated delayed phosphor of the present invention, for example, the structure described in Chemistry of Materials, 2017, 29, 1946-1963 can be used. Donor structures include carbazole, dimethylcarbazole, di-tert-butylcarbazole, dimethoxycarbazole, tetramethylcarbazole, benzofluorocarbazole, benzothienocarbazole, phenyldihydroindolocarbazole, phenylbicarbazole, bicarbazole, tercarbazole, diphenylcarbazolylamine, tetraphenylcarbazolyldiamine, phenoxazine, dihydrophenazine, phenothiazine, dimethyldihydroacridine, diphenylamine, bis(tert-butylphenyl)amine, N1-(4-(diphenylamino)phenyl)-N4,N4-diphenylbenzene-1,4-diamine, dimethyltetraphenyldihydroacridinediamine, tetramethyl-dihydro-indenoacridine, and diphenyl-dihydrodibenzazasiline.Acceptor structures include sulfonyldibenzene, benzophenone, phenylenebis(phenylmethanone), benzonitrile, isonicotinonitrile, phthalonitrile, isophthalonitrile, paraphthalonitrile, benzenetricarbonitrile, triazole, oxazole, thiadiazole, benzothiazole, benzobis(thiazole), benzoxazole, benzobis(oxazole), quinoline, benzimidazole, dibenzoquinoxaline, heptaazaphenalene, thioxanthone dioxide, dimethylanthracenone, anthracenedione, 5H-cyclopenta[1,2-b:5,4-b']dipyridine, fluorene dicarbonitrile, triphenyltriazine, pyrazinedicarbonitrile, pyrimidine, phenylpyrimidine, methylpyrimidine, pyridinedicarbonitrile, dibenzoquinoxalinedicarbonitrile, bis(phenylsulfonyl)benzene, dimethylthioxanthene dioxide, thianthrene tetraoxide, and tris(dimethylphenyl)borane. In particular, the compound having thermally activated delayed fluorescence in the TAF element is preferably a compound having at least one partial structure selected from carbazole, phenoxazine, acridine, triazine, pyrimidine, pyrazine, thioxanthene, benzonitrile, phthalonitrile, isophthalonitrile, diphenylsulfone, triazole, oxadiazole, thiadiazole, and benzophenone.

[0356] The compound used as the second component of the light-emitting layer in the TAF element is preferably a thermally activated delayed phosphor, and the emission spectrum thereof is at least partially overlapped with the absorption peak of the emitting dopant. Below, examples of compounds that can be used as the second component (thermally activated delayed phosphor) of the light-emitting layer in the TAF element are shown. However, the compounds that can be used as the thermally activated delayed phosphor in the TAF element are not limited to the following example compounds.

[0357] [ka]

[0358] [ka]

[0359] [ka]

[0360] [ka]

[0361] [ka]

[0362] Furthermore, as the thermally activated delayed fluorescent substance, a compound represented by any one of the following formulae (AD1), (AD2) and (AD3) can also be used. [ka]

[0363] In the above formulas (AD1), (AD2), and (AD3), each M is independently a single bond, -O-, >N-Ar, or >CAr2. From the viewpoints of the HOMO depth and the lowest singlet and triplet energy levels of the resulting partial structure, M is preferably a single bond, -O-, or >N-Ar. Each J is a spacer structure separating the donor partial structure and the acceptor partial structure. Each J is independently an arylene having 6 to 18 carbon atoms. From the viewpoints of the magnitude of conjugation exuded from the donor partial structure and the acceptor partial structure, an arylene having 6 to 12 carbon atoms is preferred. More specific examples include phenylene, methylphenylene, and dimethylphenylene. Each Q is independently =C(-H)- or =N-. From the viewpoints of the shallowness of the LUMO and the lowest singlet and triplet energy levels of the resulting partial structure, =N- is preferred. Each Ar is independently hydrogen, an aryl having 6 to 24 carbon atoms, a heteroaryl having 2 to 24 carbon atoms, an alkyl having 1 to 12 carbon atoms, or a cycloalkyl having 3 to 18 carbon atoms. From the viewpoint of the HOMO depth and the height of the lowest excited singlet energy level and the lowest excited triplet energy level of the partial structure to be formed, it is preferably hydrogen, an aryl having 6 to 12 carbon atoms, a heteroaryl having 2 to 14 carbon atoms, an alkyl having 1 to 4 carbon atoms, or a cycloalkyl having 6 to 10 carbon atoms, more preferably hydrogen, phenyl, tolyl, xylyl, mesityl, biphenyl, pyridyl, bipyridyl, triazinyl, carbazolyl, dimethylcarbazolyl, di-tert-butylcarbazolyl, benzimidazolyl, or phenylbenzimidazolyl, and even more preferably hydrogen, phenyl, or carbazolyl. m is 1 or 2. n is an integer of (6-m) or less, and from the viewpoint of steric hindrance, it is preferably an integer of 4 to (6-m). Furthermore, at least one hydrogen atom in the compounds represented by the above formulas may be substituted with a halogen or deuterium.

[0364] More specifically, the compounds used as the second component in this embodiment are preferably 4CzBN, 4CzBN-Ph, 5CzBN, 3Cz2DPhCzBN, 4CzIPN, 2PXZ-TAZ, Cz-TRZ3, BDPCC-TPTA, MA-TA, PA-TA, FA-TA, PXZ-TRZ, DMAC-TRZ, BCzT, DCzTrz, DDCzTRz, spiroAC-TRZ, Ac-HPM, Ac-PPM, Ac-MPM, TCzTrz, TmCzTrz, and DCzmCzTrz.

[0365] The compound used as the second component in this embodiment may be a donor-acceptor TADF compound represented by DA, in which one donor D and one acceptor A are bonded directly or via a linking group. However, a compound having a structure represented by the following formula (DAD1), in which multiple donors D are bonded to one acceptor A directly or via a linking group, is preferred because it will result in better properties for the organic electroluminescent device. (D 1 -L 1 )nA 1 (DAD1) Formula (DAD1) includes compounds represented by the following formula (DAD2). D 2 -L 2 -A 2 -L 3 -D 3 (DAD2) In the formula (DAD1) and the formula (DAD2), D 1 , D 2 and D 3 A each independently represents a donor group. As the donor group, the above-mentioned donor structure can be used. 1 and A 2 Each of L independently represents an acceptor group. The acceptor group may have the acceptor structure described above. 1 , L 2 and L 3each independently represents a single bond or a conjugated linking group. The conjugated linking group is a spacer structure that separates the donor group and the acceptor group, and is preferably an arylene having 6 to 18 carbon atoms, more preferably an arylene having 6 to 12 carbon atoms. L 1 , L 2 and L 3 It is more preferable that each of A is independently phenylene, methylphenylene or dimethylphenylene. 1 represents an integer equal to or less than the maximum number of substitutions that can be made. For example, n may be selected within the range of 2 to 10, or within the range of 2 to 6. When n is 2, the compound is represented by formula (DAD2). 1 may be the same or different, and n L 1 and may be the same or different. Preferred specific examples of the compounds represented by formula (DAD1) and formula (DAD2) include 2PXZ-TAZ and the following compounds, but the second component that can be used in the present invention is not limited to these compounds.

[0366] [ka]

[0367] In this embodiment, the light-emitting layer may be composed of either a single layer or multiple layers. The host compound, the thermally activated delayed phosphor, and the polycyclic aromatic compound of the present invention may be contained in the same layer, or at least one component may be contained in multiple layers. The host compound, the thermally activated delayed phosphor, and the polycyclic aromatic compound of the present invention contained in the light-emitting layer may each be a single type or a combination of multiple types. The assisting dopant and the emitting dopant may be contained entirely or partially in the host compound as a matrix. The light-emitting layer doped with the assisting dopant and the emitting dopant can be formed by a method of forming a film by ternary co-evaporation of the host compound, the assisting dopant, and the emitting dopant, a method of premixing the host compound, the assisting dopant, and the emitting dopant and then simultaneously evaporating them, or a wet film-forming method in which a composition for forming an light-emitting layer (paint) prepared by dissolving the host compound, the assisting dopant, and the emitting dopant in an organic solvent is applied.

[0368] The amount of the host compound used varies depending on the type of host compound and may be determined according to the properties of the host compound. The amount of the host compound used is preferably 40 to 99% by mass, more preferably 50 to 98% by mass, and even more preferably 60 to 95% by mass of the total mass of the materials for the light-emitting layer. The above ranges are preferable in terms of, for example, efficient charge transport and efficient energy transfer to the dopant.

[0369] The amount of the assisting dopant (thermally activated delayed phosphor) used varies depending on the type of the assisting dopant, and may be determined according to the properties of the assisting dopant. The amount of the assisting dopant used is preferably 1 to 60 mass % of the total mass of the materials for the light-emitting layer, more preferably 2 to 50 mass %, and even more preferably 5 to 30 mass %. The above range is preferable, for example, in that energy can be efficiently transferred to the emitting dopant.

[0370] The amount of emitting dopant (a compound having a boron atom) used varies depending on the type of emitting dopant, and may be determined according to the characteristics of the emitting dopant. The amount of emitting dopant used is preferably 0.001 to 30% by mass, more preferably 0.01 to 20% by mass, and even more preferably 0.1 to 10% by mass, of the total mass of the materials for the light-emitting layer. The above range is preferable in that, for example, concentration quenching can be prevented.

[0371] A low concentration of the emitting dopant is preferable in terms of preventing concentration quenching. A high concentration of the assisting dopant is preferable in terms of the efficiency of the thermally activated delayed fluorescence mechanism. Furthermore, from the viewpoint of the efficiency of the thermally activated delayed fluorescence mechanism of the assisting dopant, it is preferable that the concentration of the emitting dopant is lower than that of the assisting dopant.

[0372] <2-1-3. Substrates in Organic Electroluminescent Devices> The substrate 101 is a support for the organic EL device 100 and is typically made of quartz, glass, metal, plastic, or the like. The substrate 101 may be formed into a plate, film, or sheet shape depending on the purpose, and may be, for example, a glass plate, a metal plate, a metal foil, a plastic film, or a plastic sheet. Glass plates and plates made of transparent synthetic resins such as polyester, polymethacrylate, polycarbonate, and polysulfone are preferred. For glass substrates, soda-lime glass or alkali-free glass may be used. The thickness should be sufficient to maintain mechanical strength, e.g., 0.2 mm or greater. The upper limit of the thickness is, for example, 2 mm or less, preferably 1 mm or less. Regarding the glass material, alkali-free glass is preferred because it minimizes ion elution from the glass. However, commercially available soda-lime glass coated with a barrier coating such as SiO2 can also be used. In addition, in order to improve the gas barrier properties of the substrate 101, a gas barrier film such as a dense silicon oxide film may be provided on at least one side thereof, and it is particularly preferable to provide a gas barrier film when a synthetic resin plate, film, or sheet with poor gas barrier properties is used as the substrate 101.

[0373] <2-1-4. Anode in Organic Electroluminescent Device> The anode 102 serves to inject holes into the light-emitting layer 105. When either the hole injection layer 103 or 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 the hole injection layer 103 or the hole transport layer 104.

[0374] Materials for forming the anode 102 include inorganic and organic compounds. Examples of inorganic compounds include metals (aluminum, gold, silver, nickel, palladium, chromium, etc.), metal oxides (indium oxide, tin oxide, indium-tin oxide (ITO), indium-zinc oxide (IZO), etc.), metal halides (copper iodide, etc.), copper sulfide, carbon black, ITO glass, and NESA glass. Examples of organic compounds include polythiophenes such as poly(3-methylthiophene), and conductive polymers such as polypyrrole and polyaniline. In addition, materials can be appropriately selected from those used as anodes in organic EL devices.

[0375] The resistance of the transparent electrode is not limited as long as it can supply sufficient current to light the light-emitting element, but low resistance is desirable from the perspective of the power consumption of the light-emitting element. For example, an ITO substrate with a resistance of 300 Ω / □ or less can function as an element electrode, but since substrates with a resistance of about 10 Ω / □ are now available, it is particularly desirable to use a low resistance product with a resistance of, for example, 100 to 5 Ω / □, preferably 50 to 5 Ω / □. The thickness of the ITO can be selected arbitrarily depending on the resistance value, but it is usually between 50 and 300 nm.

[0376] <2-1-5. Hole injection layer and hole transport layer in organic electroluminescent device> The hole injection layer 103 serves to efficiently inject holes migrating from the anode 102 into the light-emitting layer 105 or the hole transport layer 104. The hole transport layer 104 serves to efficiently transport holes injected from the anode 102 or holes injected from the anode 102 via the hole injection layer 103 to the light-emitting layer 105. The hole injection layer 103 and the hole transport layer 104 are each formed by laminating or mixing one or more types of hole injection / transport materials, or by a mixture of a hole injection / transport material and a polymer binder. Alternatively, a layer may be formed by adding an inorganic salt such as iron (III) chloride to the hole injection / transport material.

[0377] A hole injection / transport material must be able to efficiently inject and transport holes from the positive electrode between electrodes to which an electric field is applied, and it is desirable for the material to have high hole injection efficiency and efficiently transport the injected holes. To achieve this, it is desirable for the material to have a low ionization potential, high hole mobility, excellent stability, and be less likely to generate impurities that act as traps during production and use.

[0378] As materials for forming the hole injection layer 103 and the hole transport layer 104, any compound can be selected from compounds conventionally used as charge transport materials for holes in photoconductive materials, p-type semiconductors, and known compounds used in hole injection layers and hole transport layers of organic EL devices. Specific examples thereof include carbazole derivatives (N-phenylcarbazole, polyvinylcarbazole, etc.), biscarbazole derivatives such as bis(N-arylcarbazole) or bis(N-alkylcarbazole), triarylamine derivatives (4,4',4"-tris(N-carbazolyl)triphenylamine, polymers having an aromatic tertiary amino group in the main chain or side chain, 1,1-bis(4-di-p-tolylaminophenyl)cyclohexane, N,N'-diphenyl-N,N'-di(3-methylphenyl)-4,4'-diaminobiphenyl, N,N'-diphenyl-N,N'-dinaphthyl-4,4'-diaminobiphenyl, N,N'-diphenyl-N,N'-di(3-methylphenyl)-4,4'-diphenyl-1,1'-diamine, N,N'-dinaphthyl-N,N'-diphenyl-4,4'-diphenyl-1,1'-diamine, N 4 ,N 4 '-Diphenyl-N 4 ,N 4 '-Bis(9-phenyl-9H-carbazol-3-yl)-[1,1'-biphenyl]-4,4'-diamine, N 4 ,N 4 ,N 4 ',N 4triphenylamine derivatives such as 4,4',4"-tris(3-methylphenyl(phenyl)amino)triphenylamine, starburst amine derivatives, stilbene derivatives, phthalocyanine derivatives (metal-free, copper phthalocyanine, etc.), pyrazoline derivatives, hydrazone compounds, benzofuran derivatives, thiophene derivatives, oxadiazole derivatives, quinoxaline derivatives Examples of the material include conductors (for example, 1,4,5,8,9,12-hexaazatriphenylene-2,3,6,7,10,11-hexacarbonitrile), heterocyclic compounds such as porphyrin derivatives, polysilanes, etc. Among polymers, polycarbonates and styrene derivatives having the above-mentioned monomers in their side chains, polyvinylcarbazole, and polysilanes are preferred, but there are no particular limitations on the material as long as it is a compound that can form a thin film required for fabricating a light-emitting device, can inject holes from the anode, and can transport holes.

[0379] It is also known that the conductivity of organic semiconductors is strongly influenced by their doping. Such organic semiconductor matrix materials consist of compounds with good electron-donating or electron-accepting properties. Strong electron acceptors such as tetracyanoquinone dimethane (TCNQ) or 2,3,5,6-tetrafluorotetracyano-1,4-benzoquinone dimethane (F4TCNQ) are known for doping with electron-donating substances (see, for example, M. Pfeiffer, A. Beyer, T. Fritz, K. Leo, Appl. Phys. Lett., 73(22), 3202-3204 (1998) and J. Blochwitz, M. Pfeiffer, T. Fritz, K. Leo, Appl. Phys. Lett., 73(6), 729-731 (1998)). These generate so-called holes via an electron transfer process in the electron-donating base material (hole-transporting material). The conductivity of the base material varies considerably depending on the number and mobility of holes. Examples of matrix materials with hole transport properties include benzidine derivatives (such as TPD) or starburst amine derivatives (such as TDATA), or specific metal phthalocyanines (particularly zinc phthalocyanine (ZnPc)) (see JP 2005-167175 A). The polycyclic aromatic compound of the present invention may be used as a material for forming a hole injection layer or a hole transport layer.

[0380] <2-1-6. Electron blocking layer in organic electroluminescent devices> An electron-blocking layer may be provided between the hole-injection / transport layer and the light-emitting layer to prevent diffusion of electrons from the light-emitting layer. The electron-blocking layer may be formed from a compound represented by any one of the above formulas (H1), (H2), and (H3). The polycyclic aromatic compound of the present invention may be used as a material for forming the electron-blocking layer.

[0381] <2-1-7. 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 electron transport / injection materials, or by a mixture of an electron transport / injection material and a polymer binder.

[0382] The electron injection / transport layer is a layer responsible for injecting electrons from the cathode and transporting them. It is desirable for the layer to have high electron injection efficiency and efficiently transport the injected electrons. To achieve this, it is preferable for the material to have high electron affinity, high electron mobility, excellent stability, and be less likely to generate trapping impurities during manufacture and use. However, considering the balance between hole and electron transport, if a material primarily serves to efficiently block holes from the anode from flowing to the cathode without recombining, it can have the same effect of improving luminous efficiency as a material with high electron transport ability, even if it does not have a particularly high electron transport ability. Therefore, the electron injection / transport layer in this embodiment may also function as a layer that can efficiently block the movement of holes.

[0383] The material (electron transport material) for forming the electron transport layer 106 or the electron injection layer 107 can be arbitrarily selected from compounds conventionally used as electron transport compounds in photoconductive materials and known compounds used in electron injection layers and electron transport layers of organic EL devices.

[0384] Materials used in the electron transport layer or electron injection layer preferably contain at least one selected from the group consisting of aromatic or heteroaromatic ring compounds composed of one or more atoms selected from carbon, hydrogen, oxygen, sulfur, silicon, and phosphorus; pyrrole derivatives and their fused ring derivatives; and metal complexes containing electron-accepting nitrogen. Specific examples include fused ring aromatic derivatives such as naphthalene and anthracene; styryl aromatic derivatives such as 4,4'-bis(diphenylethenyl)biphenyl; perinone derivatives; coumarin derivatives; naphthalimide derivatives; quinone derivatives such as anthraquinone and diphenoquinone; phosphine oxide derivatives; arylnitrile derivatives; and indole derivatives. Metal complexes containing electron-accepting nitrogen include, for example, hydroxyazole complexes such as hydroxyphenyloxazole complexes, azomethine complexes, tropolone metal complexes, flavonol metal complexes, and benzoquinoline metal complexes. These materials can be used alone or in combination with other materials.

[0385] Specific examples of other electron transport compounds include pyridine derivatives, naphthalene derivatives, fluoranthene derivatives, BO derivatives, anthracene derivatives, phenanthroline derivatives, perinone derivatives, coumarin derivatives, naphthalimide derivatives, anthraquinone derivatives, diphenoquinone derivatives, diphenylquinone derivatives, perylene derivatives, oxadiazole derivatives (1,3-bis[(4-t-butylphenyl)1,3,4-oxadiazolyl]phenylene, etc.), thiophene derivatives, triazole derivatives (N-naphthyl-2,5-diphenyl-1,3,4-triazole, etc.), thiadiazole derivatives, metal complexes of oxine derivatives, quinolinol metal complexes, quinoxaline derivatives, polymers of quinoxaline derivatives, benzazole compounds, gallium complexes, pyrazole derivatives, perfluorinated phenylene derivatives, triazine derivatives, pyrazine derivatives, benzoquinone, Examples of the compound include phosphorus derivatives (such as 2,2'-bis(benzo[h]quinolin-2-yl)-9,9'-spirobifluorene), imidazopyridine derivatives, borane derivatives, benzimidazole derivatives (such as tris(N-phenylbenzimidazol-2-yl)benzene), benzoxazole derivatives, thiazole derivatives, benzothiazole derivatives, quinoline derivatives, oligopyridine derivatives such as terpyridine, bipyridine derivatives, terpyridine derivatives (such as 1,3-bis(2,2':6',2"-terpyridin-4'-yl)benzene), naphthyridine derivatives (such as bis(1-naphthyl)-4-(1,8-naphthyridin-2-yl)phenylphosphine oxide), aldazine derivatives, pyrimidine derivatives, arylnitrile derivatives, indole derivatives, phosphine oxide derivatives, bisstyryl derivatives, silole derivatives, and azoline derivatives.

[0386] Metal complexes having an electron-accepting nitrogen atom can also be used, and examples thereof include hydroxyazole complexes such as quinolinol metal complexes and hydroxyphenyloxazole complexes, azomethine complexes, tropolone metal complexes, flavonol metal complexes, and benzoquinoline metal complexes.

[0387] The above-mentioned materials may be used alone or in combination with other materials.

[0388] 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, quinolinol-based metal complexes, thiazole derivatives, benzothiazole derivatives, silole derivatives, and azoline derivatives are preferred.

[0389] The polycyclic aromatic compound of the present invention may be used as a material for forming an electron injection layer or an electron transport layer.

[0390] The electron transport layer or the electron injection layer may further contain a substance capable of reducing the material forming the electron transport layer or the electron injection layer. Various substances can be used as this reducing substance as long as they have a certain level of reducing ability. For example, at least one selected from the group consisting of alkali metals, alkaline earth metals, rare earth metals, alkali metal oxides, alkali metal halides, alkaline earth metal oxides, alkaline earth metal halides, rare earth metal oxides, rare earth metal halides, alkali metal organic complexes, alkaline earth metal organic complexes, and rare earth metal organic complexes can be suitably used.

[0391] Preferred reducing substances include alkali metals such as Na (work function 2.36 eV), K (2.28 eV), Rb (2.16 eV), and Cs (1.95 eV), and alkaline earth metals such as Ca (2.9 eV), Sr (2.0-2.5 eV), and Ba (2.52 eV), with substances with a work function of 2.9 eV or less being particularly preferred. Among these, more preferred reducing substances are alkali metals such as K, Rb, and Cs, with Rb or Cs being even more preferred, and Cs being the most preferred. These alkali metals have particularly high reducing ability, and adding a relatively small amount of these metals to the material forming the electron transport layer or electron injection layer can improve the luminance and extend the life of the organic EL device. Furthermore, as a reducing substance having a work function of 2.9 eV or less, a combination of two or more of these alkali metals is also preferred, and in particular, a combination containing Cs is preferred, such as a combination of Cs and Na, Cs and K, Cs and Rb, or Cs, Na and K. By including Cs, the reducing ability can be efficiently exerted, and by adding Cs to the material forming the electron transport layer or electron injection layer, the luminance of the organic EL device can be improved and the lifetime can be extended.

[0392] <2-1-8. Cathode in organic electroluminescent devices> The cathode 108 serves to inject electrons into the light-emitting layer 105 through the electron injection layer 107 and the electron transport layer 106 .

[0393] The material for the cathode 108 is not particularly limited as long as it can efficiently inject electrons into the organic layer, but materials similar to those for the anode 102 can be used. Among these, metals such as tin, indium, calcium, aluminum, silver, copper, nickel, chromium, gold, platinum, iron, zinc, lithium, sodium, potassium, cesium, and magnesium, or alloys thereof (e.g., magnesium-silver alloys, magnesium-indium alloys, and aluminum-lithium alloys such as lithium fluoride / aluminum alloys), are preferred. To increase electron injection efficiency and improve device characteristics, lithium, sodium, potassium, cesium, calcium, magnesium, or alloys containing these low-work-function metals are effective. However, these low-work-function metals are generally unstable in air. To address this issue, a method has been proposed in which a trace amount of lithium, cesium, or magnesium is doped into the organic layer to create a highly stable electrode. Other dopants that can be used include inorganic salts such as lithium fluoride, cesium fluoride, lithium oxide, and cesium oxide. However, these are not limited to these.

[0394] Further, for electrode protection, preferred examples include lamination of metals such as platinum, gold, silver, copper, iron, tin, aluminum, and indium, or alloys using these metals, inorganic materials such as silica, titania, and silicon nitride, polyvinyl alcohol, vinyl chloride, hydrocarbon polymer compounds, etc. The method for producing these electrodes is not particularly limited as long as electrical conduction can be achieved, and may include resistance heating, electron beam evaporation, sputtering, ion plating, and coating.

[0395] <2-1-9. Binders that may be used in each layer> The materials used for the hole injection layer, hole transport layer, light-emitting layer, electron transport layer, and electron injection layer can be used alone to form each layer, but they can also be dispersed as a polymer binder in solvent-soluble resins such as polyvinyl chloride, polycarbonate, polystyrene, poly(N-vinylcarbazole), polymethyl methacrylate, polybutyl methacrylate, polyester, polysulfone, polyphenylene oxide, polybutadiene, hydrocarbon resins, ketone resins, phenoxy resins, polyamide, ethyl cellulose, vinyl acetate resin, ABS resin, and polyurethane resin, or curable resins such as phenol resin, xylene resin, petroleum resin, urea resin, melamine resin, unsaturated polyester resin, alkyd resin, epoxy resin, and silicone resin.

[0396] <2-1-10. Method for producing organic electroluminescent device> Each layer constituting an organic EL device can be formed by forming the material to be formed into a thin film using methods such as vapor deposition, resistance heating vapor deposition, electron beam vapor deposition, sputtering, molecular lamination, printing, inkjet printing, spin coating or casting, and coating. There are no particular limitations on the film thickness of each layer formed in this way, and it can be set appropriately depending on the properties of the material, but it is usually in the range of 2 nm to 5000 nm. The film thickness can usually be measured with a quartz oscillator film thickness measuring device. When forming a thin film using vapor deposition, the vapor deposition conditions vary depending on the type of material, the desired crystal structure and association structure of the film, etc. Vapor deposition conditions are generally a boat heating temperature of +50 to +400°C, a vacuum degree of 10 -6 ~10 -3 It is preferable to appropriately set the pressure, the deposition rate, the substrate temperature, and the film thickness in the range of 0.01 to 50 nm / sec, -150 to +300° C., and 2 nm to 5 μm.

[0397] Next, as an example of a method for fabricating an organic EL device, we will explain a method for fabricating an organic EL device consisting of an anode, a hole injection layer, a hole transport layer, an emitting layer composed of a host material and a dopant material, an electron transport layer, an electron injection layer, and a cathode. A thin film of an anode material is formed on a suitable substrate by vapor deposition or other methods to form an anode, and then a thin film of a hole injection layer and a hole transport layer is formed on the anode. A thin film of a host material and a dopant material is co-deposited on the anode to form an emitting layer. An electron transport layer and an electron injection layer are then formed on the emitting layer, and a thin film of a cathode material is further formed by vapor deposition or other methods to form a cathode, thereby obtaining the desired organic EL device. It should be noted that the above-described organic EL device can also be fabricated in the reverse order: cathode, electron injection layer, electron transport layer, emitting layer, hole transport layer, hole injection layer, and anode.

[0398] When applying a DC voltage to the organic EL element obtained in this way, the anode should be set to + and the cathode to -. When a voltage of about 2 to 40 V is applied, light emission can be observed from the transparent or semi-transparent electrode side (anode or cathode, or both). This organic EL element also emits light when a pulse current or an AC current is applied. The waveform of the applied AC current can be any waveform.

[0399] <2-1-11. Application examples of organic electroluminescent devices> The organic EL element can also be applied to a display device or a lighting device. A display device or lighting device including an organic EL element can be manufactured by a known method, such as by connecting the organic EL element to a known driving device, and can be driven appropriately using a known driving method such as DC driving, pulse driving, or AC driving.

[0400] Examples of display devices include panel displays such as color flat panel displays, and flexible displays such as flexible color organic electroluminescent (EL) displays (see, for example, JP-A-10-335066, JP-A-2003-321546, and JP-A-2004-281086). Examples of display methods include either a matrix or segment method. Note that matrix display and segment display may coexist on the same panel.

[0401] In a matrix display, pixels are arranged two-dimensionally, such as in a grid or mosaic pattern, and a collection of pixels displays characters and images. The shape and size of the pixels are determined by the application. For example, images and text displayed on computers, monitors, and televisions typically use square pixels with sides of 300 μm or less. Large displays such as display panels use pixels on the order of millimeters. For monochrome displays, pixels of the same color are simply arranged, while for color displays, red, green, and blue pixels are displayed side by side. These types are typically known as delta and stripe types. The matrix can be driven by either line-sequential or active matrix methods. While line-sequential driving has the advantage of being simpler, active matrix methods can sometimes be superior in terms of operating characteristics, so the choice must be made based on the application.

[0402] In the segment type, a pattern is formed to display predetermined information, and a predetermined area is illuminated. Examples include the time and temperature displays on digital clocks and thermometers, the operating status displays on audio equipment and induction cookers, and panel displays on automobiles.

[0403] Examples of lighting devices include lighting devices for indoor lighting and backlights for liquid crystal display devices (see, for example, JP 2003-257621 A, JP 2003-277741 A, JP 2004-119211 A, etc.). Backlights are primarily used to improve the visibility of non-self-luminous display devices, and are used in liquid crystal display devices, clocks, audio equipment, automobile panels, display boards, signs, etc. In particular, for backlights for liquid crystal display devices, especially for personal computers, where thinning is an issue, considering that conventional methods use fluorescent lamps and light guide plates and therefore are difficult to achieve, backlights using organic EL elements are characterized by their thinness and light weight.

[0404] <2-2. Other organic devices> The polycyclic aromatic compound according to the present invention can be used to produce not only the above-mentioned organic electroluminescent device but also an organic field effect transistor or an organic thin-film solar cell.

[0405] 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 transistor can control the current by arbitrarily blocking the flow of electrons (or holes) flowing between the source and drain electrodes. Field-effect transistors are easier to miniaturize than simple transistors (bipolar transistors), and are often used as elements that make up integrated circuits.

[0406] 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 device 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 / 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 configured in this manner can be used as a pixel driving switching element for an active matrix driving liquid crystal display or an organic electroluminescence display.

[0407] An 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 the hole transport layer, p-type semiconductor layer, n-type semiconductor layer, or 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 electron transport material in an organic thin-film solar cell. In addition to the above, the organic thin-film solar cell may also include a hole blocking layer, electron blocking layer, electron injection layer, hole injection layer, smoothing layer, etc. as appropriate. Known materials used in organic thin-film solar cells can be appropriately selected and combined for use in the organic thin-film solar cell.

[0408] <3. Wavelength conversion materials> The polycyclic aromatic compound of the present invention can be used as a wavelength converting material. Currently, the application of color conversion technology to multicolor displays, organic light-emitting diode (OLED) displays, and lighting is being actively investigated. Color conversion refers to the wavelength conversion of light emitted from a light emitter to light of a longer wavelength, such as converting ultraviolet or blue light to green or red light. By fabricating a film of wavelength conversion materials with this color conversion function and combining it with a blue light source, for example, it is possible to extract the three primary colors of blue, green, and red from the blue light source, i.e., white light. A white light source combining such a blue light source with a wavelength conversion film with color conversion functionality can be used as a light source unit, and combined with a liquid crystal driver and color filters, it is possible to create a full-color display. Furthermore, if the liquid crystal driver is not required, the white light source can be used as is, for example, in LED lighting. Furthermore, by combining a blue organic light-emitting diode (OLED) element as a light source with a wavelength conversion film that converts blue light to green and red, it is possible to fabricate a full-color OLED display without using a metal mask. Furthermore, by using blue microLEDs as a light source in combination with wavelength conversion films that convert blue light into green and red light, it becomes possible to create low-cost full-color microLED displays.

[0409] The polycyclic aromatic compound of the present invention can be used as this wavelength converting material. Using a wavelength converting material containing the polycyclic aromatic compound of the present invention, light from a light source or 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 display devices (display devices using organic EL elements and liquid crystal display devices). The converted color can be adjusted by appropriately selecting the substituents 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. Furthermore, this wavelength converting composition may be used to form a wavelength conversion film.

[0410] The wavelength-converting composition may contain, in addition to the polycyclic aromatic compound of the present invention, a binder resin, other additives, and a solvent. Examples of binder resins that can be used include those described in paragraphs

[0173] to

[0176] of WO 2016 / 190283. Examples of other additives that can be used include compounds described in paragraphs

[0177] to

[0181] of WO 2016 / 190283. For the solvent, the description of the solvent contained in the composition for forming an emitting layer can be referenced.

[0411] The wavelength conversion film includes a wavelength converting layer formed by curing a wavelength converting composition. Known film formation 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 solely of a wavelength converting layer formed from a composition containing the polycyclic aromatic compound of the present invention, or may also include other wavelength converting layers (e.g., a wavelength converting layer that converts blue light to green light or red light, or a wavelength converting layer that converts blue light or green light to red light). The wavelength conversion film may further include a substrate layer and a barrier layer to prevent deterioration of the color converting layer due to oxygen, moisture, or heat. [Example]

[0412] The present invention will be explained in more detail below with reference to examples, but the present invention is not limited to these examples. In the examples, APCI-MS means atmospheric pressure chemical ionization mass spectrometry.

[0413] <<Synthesis Example>>

[0414] <Synthesis Example (1): Synthesis of Compound (1-015)> [ka]

[0415] Under a nitrogen atmosphere, 5-bromobenzo[b]thiophene (68.6 g), 2-(6-(tert-butyl)naphthalen-2-yl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (100 g), dichlorobis[di-t-butyl(4-dimethylaminophenyl)phosphino]palladium(II) (Pd-132) (0.685 g) as a palladium catalyst, potassium carbonate (66.8 g), cyclopentyl methyl ether (CPME) (100 mL), and water (300 mL) were placed in a flask and stirred at 90 °C for 1 h. After the reaction was completed, water and toluene were added to the reaction mixture and stirred. The organic layer was separated and washed with water. The organic layer was then concentrated to obtain a crude product, which was purified using a silica gel short column (eluent: toluene). The product was further recrystallized from ethanol (200 mL) to obtain intermediate (Int-1-1) (87.6 g).

[0416] [ka]

[0417] Under a nitrogen atmosphere, intermediate (Int-1-1) (87.6 g) and THF (440 mL) were placed in a flask and cooled to 0°C. N-bromosuccinimide (NBS) (54.2 g) was added and stirred at 45°C for 1 hour. After the reaction was completed, aqueous sodium sulfite solution and toluene were added to the reaction solution and stirred, after which the organic layer was separated and washed with water. The organic layer was then concentrated to obtain a crude product, which was purified using a silica gel short column (eluent: heptane). The crude product was further recrystallized from ethanol (200 mL) to obtain intermediate (Int-1-2) (91.4 g).

[0418] [ka]

[0419] Under a nitrogen atmosphere, intermediate (Int-1-2) (30.0 g), 4-(tert-butyl)aniline (11.3 g), Pd-132 (1.07 g) as a palladium catalyst, tBuONa (10.9 g), and toluene (240 ml) were placed in a flask and stirred at reflux for 2 hours. After the reaction was completed, water and toluene were added to the reaction solution and stirred. The organic layer was separated and washed with water. The organic layer was then concentrated, and the resulting crude product was purified using a silica gel short column (eluent: toluene / heptane = 1 / 4 (volume ratio)) to obtain intermediate (Int-1-3) (29.6 g).

[0420] [ka]

[0421] Under a nitrogen atmosphere, intermediate (Int-1-4) (30.0 g), 5-(tert-butyl)-1,2,3-trichlorobenzene (21.1 g), Pd-132 (1.89 g) as a palladium catalyst, tBuONa (12.8 g), and toluene (240 ml) were placed in a flask and stirred at reflux for 4 hours. After the reaction was completed, water and toluene were added to the reaction mixture and stirred. The organic layer was separated and washed with water. The organic layer was then concentrated to obtain a crude product, which was purified using a silica gel short column (eluent: toluene / heptane = 1 / 9 (volume ratio)). Further recrystallization from ethanol yielded intermediate (Int-1-5) (37.3 g).

[0422] [ka]

[0423] Under a nitrogen atmosphere, intermediate (Int-1-5) (30.0 g), intermediate (Int-1-3) (25.8 g), palladium catalyst Pd-132 (1.18 g), tBuONa (10.7 g), and toluene (240 ml) were placed in a flask and stirred at reflux for 2 hours. After the reaction was completed, water and ethyl acetate were added to the reaction solution and stirred. The organic layer was separated and washed with water. The organic layer was then concentrated and the resulting crude product was purified using a silica gel short column (eluent: toluene / heptane = 1 / 3 (volume ratio)) to obtain intermediate (Int-1-015) (40.9 g).

[0424] [ka]

[0425] A 1.60 M t-butyllithium pentane solution (19.4 ml) was added to a flask containing intermediate (Int-1-015) (15.0 g) and t-butylbenzene (150 ml) under a nitrogen atmosphere at 0°C. After the dropwise addition, the mixture was heated to 70°C and stirred for 0.5 hours. Components with boiling points lower than t-butylbenzene were then removed by distillation under reduced pressure. The mixture was cooled to -50°C, boron tribromide (7.78 g) was added, and the mixture was warmed to room temperature and stirred for 0.5 hours. The mixture was then cooled again to 0°C, N,N-diisopropylethylamine (4.01 g) was added, and the mixture was stirred at room temperature until the heat generation subsided. The mixture was then heated to 70°C and stirred for 1 hour. The reaction mixture was cooled to room temperature, and aqueous sodium acetate solution cooled in an ice bath was added, followed by ethyl acetate, and the mixture was separated. The organic layer was concentrated and purified using a silica gel short column (eluent: toluene / heptane = 1 / 2 (volume ratio)). The obtained crude product was recrystallized from toluene to obtain compound (1-015) (2.62 g).

[0426] [ka] APCI-MS confirmed that this was the target product with m / z (M+H) = 939.61.

[0427] <Synthesis Example (2): Synthesis of Compound (1-103)> Compound (1-103) was obtained from intermediate (Int-1-103) in the same manner as in the synthesis of compound (1-015). [ka] APCI-MS confirmed that this was the target product with m / z (M+H) = 923.51.

[0428] <Synthesis Example (3): Synthesis of Compound (1-022)> Compound (1-022) was obtained from intermediate (Int-1-022) in the same manner as in the synthesis of compound (1-015). [ka] APCI-MS confirmed that this was the target product with m / z (M+H) = 973.70.

[0429] <Synthesis Example (4): Synthesis of Compound (1-082)> Compound (1-082) was obtained from intermediate (Int-1-082) in the same manner as in the synthesis of compound (1-015). [ka] APCI-MS confirmed that this was the target product with m / z (M+H) = 1123.74.

[0430] <Synthesis Example (5): Synthesis of Compound (1-133)> Compound (1-133) was obtained from intermediate (Int-1-133) in the same manner as in the synthesis of compound (1-015). [ka] APCI-MS confirmed that this was the target product with m / z (M+H) = 1014.53.

[0431] <Synthesis Example (6): Synthesis of Compound (1-151)> Compound (1-151) was obtained from intermediate (Int-1-151) in the same manner as in the synthesis of compound (1-015). [ka] APCI-MS confirmed that this was the target product with m / z (M+H) = 869.56.

[0432] <Synthesis Example (7): Synthesis of Compound (1-071)> Compound (1-071) was obtained from intermediate (Int-1-071) in the same manner as in the synthesis of compound (1-015). [ka] APCI-MS confirmed that this was the target product with m / z (M+H) = 1238.80.

[0433] <Synthesis Example (8): Synthesis of Compound (1-056)> Compound (1-056) was obtained from intermediate (Int-1-056) in the same manner as in the synthesis of compound (1-015). [ka] APCI-MS confirmed that this was the target product with m / z (M+H) = 1104.52.

[0434] <Synthesis Example (9): Synthesis of Compound (1-173)> Compound (1-173) was obtained from intermediate (Int-1-173) in the same manner as in the synthesis of compound (1-015). [ka] APCI-MS confirmed that this was the target substance with m / z (M+H) = 1090.56.

[0435] <Synthesis Example (10): Synthesis of Compound (1-170)> Compound (1-170) was obtained from intermediate (Int-1-170) in the same manner as in the synthesis of compound (1-015). [ka] It was confirmed by APCI-MS that the target substance has m / z(M+H)=1045.67.

[0436] <Synthesis Example (11): Synthesis of Compound (1-203)> Compound (1-203) was obtained from intermediate (Int-1-203) in the same manner as the synthesis of compound (1-015). [Chemical Formula] It was confirmed by APCI-MS that the target substance has m / z(M+H)=1156.68.

[0437] <Synthesis Example (12): Synthesis of Compound (1-205)> Compound (1-205) was obtained from intermediate (Int-1-205) in the same manner as the synthesis of compound (1-015). [Chemical Formula] It was confirmed by APCI-MS that the target substance has m / z(M+H)=1104.63.

[0438] <Synthesis Example (13): Synthesis of Compound (1-211)> Compound (1-211) was obtained from intermediate (Int-1-211) in the same manner as the synthesis of compound (1-015). [Chemical Formula] It was confirmed by APCI-MS that the target substance has m / z(M+H)=1306.55. <00F2844> <Possibility of Application to Organic EL Devices> Since the compound of the present invention is characterized by an appropriate energy gap (Eg), high triplet excitation energy (E T ), and a small ΔEST, it can be expected to be applied to, for example, a light-emitting layer and a charge transport layer, and particularly to a light-emitting layer.

[0440] <B. Evaluation of Vacuum Deposition-Type Organic EL Devices> Next, the preparation and evaluation of an organic EL device using the polycyclic aromatic compound of the present invention will be described.

[0441] <Structure of organic EL element> The material configurations of the layers in the organic EL devices of Examples B1 to B13 and Comparative Examples B1 to B4 are shown in Tables 1 and 2 below.

[0442] [Table 1]

[0443] [Table 2]

[0444] The chemical structures of "HI," "HAT-CN," "HT-1," "HT-2," "ET-1," "ET-2," "BH," and "Liq" in Tables 1 and 2, as well as "Comparative Compound (1) and Comparative Compound (2)" described in CN115925731A, "Comparative Compound (3)" described in WO2022050710A1, and "Comparative Compound (4)" described in CN117209461A are shown below. [ka] [ka]

[0445] <Element of Example B1> A 26 mm × 28 mm × 0.7 mm glass substrate (manufactured by Optoscience Co., Ltd.) was used as a transparent support substrate. An ITO film was formed to a thickness of 180 nm by sputtering and polished to 150 nm. This transparent support substrate was fixed to the substrate holder of a commercially available evaporation system (manufactured by Showa Vacuum Co., Ltd.). A molybdenum evaporation boat containing HI, HAT-CN, HT-1, HT-2, BH, compound (1-015), ET-1, and ET-2, and an aluminum nitride evaporation boat containing Liq, LiF, and aluminum, were attached.

[0446] The following layers were formed in order on the ITO film of the transparent support substrate. -4 The pressure was reduced to 10 Pa, and HI was first heated and evaporated to a thickness of 40 nm, followed by HAT-CN, which was heated and evaporated to a thickness of 5 nm, followed by HT-1, which was heated and evaporated to a thickness of 45 nm, and then HT-2, which was heated and evaporated to a thickness of 10 nm, to form a four-layer hole layer. Next, BH and compound (1-015) were simultaneously heated and evaporated to a thickness of 25 nm to form an emissive layer. The evaporation rate was adjusted so that the mass ratio of BH to compound (1-015) was approximately 97:3. Next, ET-1 was heated and evaporated to a thickness of 5 nm, followed by ET-2 and Liq, which were simultaneously heated and evaporated to a thickness of 25 nm to form a two-layer electron layer. The evaporation rate was adjusted so that the mass ratio of ET-2 to Liq was approximately 50:50. The evaporation rate for each layer was 0.01–1 nm / s. Thereafter, LiF was heated and evaporated at a deposition rate of 0.01 to 0.1 nm / sec to a thickness of 1 nm, and then aluminum was heated and evaporated to a thickness of 100 nm to form a cathode, thereby obtaining an organic EL device.

[0447] <Devices of Examples B2 to B13 and Comparative Examples B1 to B4> Organic EL devices of Examples B2 to B13 and Comparative Examples B1 to B4 were obtained in the same manner as in Example B1, except that each dopant material shown in Tables 1 and 2 was used instead of compound (1-015).

[0448] <Evaluation of organic EL characteristics> For the organic EL devices of Examples B1 to B13 and Comparative Examples B1 to B4, a direct current voltage of 1000 cd / m was applied to the ITO electrode as the anode and the LiF / aluminum electrode as the cathode. 2 The driving voltage during light emission, external quantum efficiency, and device lifetime were measured. 2 This is the time during which the device maintains 95% or more of its initial brightness when continuously driven at the voltage required for light emission. The results are shown in Tables 3 and 4.

[0449] The quantum efficiency of a light-emitting element can be classified into internal quantum efficiency and external quantum efficiency, and the internal quantum efficiency indicates the rate at which external energy injected as electrons (or holes) into the light-emitting layer of the light-emitting element is converted purely into photons. On the other hand, the external quantum efficiency is calculated based on the amount of these photons that are emitted to the outside of the light-emitting element, and since some of the photons generated in the light-emitting layer are absorbed or continue to be reflected inside the light-emitting element and are not emitted to the outside of the light-emitting element, the external quantum efficiency is lower than the internal quantum efficiency.

[0450] The external quantum efficiency was measured as follows: Using an Advantest voltage / current generator R6144, the luminance of the element was 1000 cd / m 2 The device emits light by applying a voltage that satisfies the above equation. Using a TOPCON SR-3AR spectroradiometer, the spectral radiance in the visible light region was measured perpendicular to the light-emitting surface. Assuming that the light-emitting surface is a perfectly diffusing surface, the measured spectral radiance value for each wavelength component was divided by the wavelength energy and multiplied by π to obtain the number of photons at each wavelength. The number of photons was then integrated over the entire wavelength range observed to obtain the total number of photons emitted from the device. The applied current value divided by the elementary charge is defined as the number of carriers injected into the device, and the total number of photons emitted from the device divided by the number of carriers injected into the device is the external quantum efficiency.

[0451] [Table 3]

[0452] [Table 4]

[0453] As described above, some of the compounds according to the present invention have been evaluated as materials for organic EL devices and shown to be excellent materials, but other compounds that have not been evaluated also have the same basic skeleton and have similar structures overall, and those skilled in the art will understand that they are similarly excellent materials for organic EL devices. [Industrial Applicability]

[0454] The polycyclic aromatic compound of the present invention is useful as a material for organic devices, particularly as a material for forming an emitting layer of an organic electroluminescent element. By using the polycyclic aromatic compound of the present invention as a dopant for the emitting layer, an organic electroluminescent element having a long life, a low driving voltage, or high light emission efficiency, particularly a long life or high light emission efficiency, can be obtained. [Explanation of symbols]

[0455] 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), R ａ１ ~R ａ３ , R ｂ１ ~R ｂ４ , R ｃ１ ~R ｃ４ are each independently hydrogen or a substituent, provided that R ｃ１ ~R ｃ４ At least one of is a group represented by formula (1-1); Y １ is B, P, P═O, P═S, Al, Ga, As, Si—R, or Ge—R, and R of the Si—R and the Ge—R is a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted alkyl, or a substituted or unsubstituted cycloalkyl; X １ and X ２ are each independently >O, >N-R ＮＸ , >C(-R ＣＸ ) ２ , >Si(-R ＩＸ ) ２ , >S, or >Se, and R ＮＸ is hydrogen, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted alkyl, or substituted or unsubstituted cycloalkyl; R ＣＸ are each independently hydrogen, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted alkyl, or substituted or unsubstituted cycloalkyl; ＣＸ may be bonded to each other to form a ring, and R ＩＸ are each independently hydrogen, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted alkyl, or substituted or unsubstituted cycloalkyl; ＩＸ may be bonded to each other to form a ring, and R ＮＸ , R ＣＸ , and R ＩＸ are each connected to R by a linking group or a single bond. ａ３ or R ｂ１ may be bonded to at least one of the carbon atoms to which R ａ１ or R ｃ４ may be bonded to at least one of the carbons to which is attached; In formula (1-1), * indicates the bond position; R ｄ１ ~R ｄ７ are each independently hydrogen or a substituent; In the above structure, at least one selected from the group consisting of an aryl ring and a heteroaryl ring may be fused with at least one cycloalkane, and 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. X １ and X ２ However, both are >N-R ＮＸ The polycyclic aromatic compound according to claim 1, wherein

3. R ＮＸ are each independently a substituted or unsubstituted phenyl, a substituted or unsubstituted biphenylyl, a substituted or unsubstituted terphenylyl, a substituted or unsubstituted dibenzofuranyl, or a substituted or unsubstituted carbazolyl; R ＮＸ 3. The polycyclic aromatic compound according to claim 2, wherein the aryl or heteroaryl ring is optionally fused with at least one cycloalkane.

4. The Y １ The polycyclic aromatic compound according to claim 1 , wherein

5. R ａ１ ~R ａ３ 2. The polycyclic aromatic compound according to claim 1, wherein each independently represents hydrogen, a substituted or unsubstituted aryl, a substituted or unsubstituted alkyl, or a substituted silyl.

6. R ａ１ and R ａ３ are all hydrogen, and R ａ２ The polycyclic aromatic compound according to claim 5 , wherein is hydrogen, substituted or unsubstituted aryl, substituted or unsubstituted alkyl, or substituted silyl.

7. R ｂ１ ~R ｂ４ Among them, R ｂ２ or R ｂ３ is a substituent, and R ｂ１ and R ｂ４ are both hydrogen, or R ｂ２ and R ｂ３ are bonded to each other to form a partial structure represented by formula (B11) or formula (B12), and R ｂ１ and R ｂ４ and each of the following is hydrogen; 【Chemistry 2】 In each of formulas (B11) and (B12), Me is methyl, and * indicates the bonding position.

8. R ｂ１ ~R ｂ４ Among them, R ｂ２ The polycyclic aromatic compound according to claim 1 , wherein is a substituted or unsubstituted diarylamino.

9. R Ｃ２ and R Ｃ３ The polycyclic aromatic compound according to claim 1, wherein at least one of the above is a group represented by formula (1-1):

10. In formula (1-1), R ｄ１ ~R ｄ７ 3. The polycyclic aromatic compound according to claim 1, wherein each independently represents hydrogen, a substituted or unsubstituted aryl, or an unsubstituted alkyl.

11. In formula (1-1), R ｄ１ ~R ｄ３ , R ｄ５ ~R ｄ７ are all hydrogen, and R ｄ４ The polycyclic aromatic compound according to claim 10, wherein is hydrogen, a substituted or unsubstituted aryl, or an unsubstituted alkyl.

12. The polycyclic aromatic compound according to claim 1, represented by any one of the following formulas: 【Transformation 3】 【Chemistry 4】 【Transformation 5】 【Transformation 6】 【Transformation 7】 【Transformation 8】 【Chemistry 9】 【Chemistry 10】 【Chemistry 11】 【Chemistry 12】 【Chemistry 13】 【Chemistry 14】 【Chemistry 15】 【Chemistry 16】 【Chemistry 17】 [Chemistry 18] In the formula, Me is methyl, tBu is t-butyl, and D is deuterium.

13. A material for an organic device, comprising the polycyclic aromatic compound according to any one of claims 1 to 12.

14. An organic electroluminescent device comprising a pair of electrodes consisting of an anode and a cathode, and a light-emitting layer disposed between the pair of electrodes, wherein the light-emitting layer contains the polycyclic aromatic compound according to any one of claims 1 to 12.

15. The organic electroluminescent device according to claim 14 , wherein the light-emitting layer comprises a host and a dopant, and the dopant comprises a polycyclic aromatic compound.

16. The organic electroluminescent device according to claim 15, wherein the host is an anthracene compound, a fluorene compound, or a dibenzochrysene compound.

17. A display device or a lighting device comprising the organic electroluminescent device according to claim 14.

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