Polycyclic aromatic compound

Abstract

To provide a compound suitable as materials for organic devices such as organic electroluminescence elements.SOLUTION: A polycyclic aromatic compound has a structure composed of one or more structural units represented by formula (1). Ra1-Ra3 and Rb1-Rb4 each represent H or a substituent; at least two of Rc1-Rc4 are substituents, with the other being H; L is >O, >C(-CH3)2, or >S; Y1 is B; X1 and X2 each represent >N-RNX (RNX is a substituted or unsubstituted aryl).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 device, and a display device and a lighting device, each containing the polycyclic aromatic compound. [Background technology]

[0002] Conventionally, display devices using electroluminescent light-emitting elements have been extensively studied because they can be made to be energy-saving and thin, and organic electroluminescent elements made from organic materials have been actively studied because they can be easily made lighter and larger. In particular, there has been active research into the development of organic materials that have the luminescence properties of blue, 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 an organic compound disposed between the pair of electrodes. The layers containing the organic compound 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 described 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 have conducted extensive research to solve the above problems, and have succeeded in producing a novel polycyclic aromatic compound having a structure similar to that of the compounds described in Patent Documents 1 and 2, which has superior light-emitting properties. The inventors have also found that an excellent organic EL device can be obtained by disposing a layer containing this polycyclic aromatic compound between a pair of electrodes to form an organic EL device, and have completed the present invention. That is, the present invention provides the following polycyclic aromatic compound, and further provides an organic device material containing the following polycyclic aromatic compound, etc. 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]

[0009] In formula (1), R a1 ~R a3 , R b1 ~R b4 are each independently hydrogen or a substituent; R c1 ~R c4 at least two of are independently a substituent and the others are hydrogen; 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 substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted alkyl, or substituted or unsubstituted cycloalkyl; L is >NR NL , >O, >C(-R CL )2, >Si(-R IL )2, >S, or >Se, and R NL , R CL , and R IL are each independently hydrogen, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted alkyl, or substituted or unsubstituted cycloalkyl; CL may be bonded to each other to form a ring, and two R IL may be linked together to form a ring; 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, 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. a3and / or R b1 , or R a1 and / or R c4 may be combined with; 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.

[0010] <2> R c1 ~R c4 At least one of the groups is a substituted or unsubstituted aryl, and at least one of the groups is a substituted or unsubstituted aryl or alkyl. <1> The polycyclic aromatic compound according to claim 1. <3> R c1 ~R c4 At least two of the groups are independently substituted or unsubstituted aryl. <1> The polycyclic aromatic compound according to claim 1. <4> X 1 and X 2 However, both are >NR NX and R NXare 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> ~ <3> 2. The polycyclic aromatic compound according to claim 1 . <5> R NX are each independently phenyl which may be substituted with alkyl or cycloalkyl, or 2-biphenylyl which may be substituted with alkyl or cycloalkyl, and R NX wherein the aryl ring is optionally fused with at least one cycloalkane; <4> The polycyclic aromatic compound according to claim 1. <6> L is >O, <1> ~ <5> 2. The polycyclic aromatic compound according to claim 1 .

[0011] <7> R a1 ~R a3 are each independently hydrogen or unsubstituted alkyl; <1> ~ <6> 2. The polycyclic aromatic compound according to claim 1 . <8> R a1 and R a3 are all hydrogen, and R a2 is hydrogen or unsubstituted alkyl; <1> ~ <6> 2. The polycyclic aromatic compound according to claim 1 .

[0012] <9> R b1 ~R b4 Of these, R b2 or R b3 are each independently a substituent and the others are 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> ~ <8> The polycyclic aromatic compound according to any one of the preceding claims. [ka] In each of formulae (B11) and (B12), Me is methyl, and * indicates the bonding position.

[0013] <10> Represented by one of the following formulas: <1> 4. A polycyclic aromatic compound according to claim 1 ; [ka] In the formula, Me is methyl and tBu is t-butyl.

[0014] <11> <1> ~ <10> 2. A material for an organic device, comprising the polycyclic aromatic compound according to claim 1. <12> 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> ~ <10> 2. An organic electroluminescence device comprising the polycyclic aromatic compound according to claim 1. <13> the light-emitting layer contains a host and the polycyclic aromatic compound as a dopant; <12> The organic electroluminescent device according to claim 1. <14> The host is an anthracene compound, a fluorene compound, or a dibenzochrysene compound; <13> The organic electroluminescent device according to claim 1. <15> <12> ~ <14> A display device or a lighting device comprising the organic electroluminescent device according to any one of claims 1 to 4. Effect of the Invention

[0015] The present invention provides a novel polycyclic aromatic compound useful as a material for organic devices such as organic electroluminescence elements. The polycyclic aromatic compound of the present invention can be used in the manufacture of organic devices such as organic electroluminescence elements. [Brief description of the drawings]

[0016] [Figure 1] FIG. 1 is a schematic cross-sectional view showing an example of an organic electroluminescent device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] The present invention will be described in detail below. The following description of the constituent elements may be based on representative embodiments or specific examples, but the present invention is not limited to such embodiments. In this specification, a numerical range expressed using "~" means a range including the numerical values ​​before and after "~" as the lower and upper limits. In this specification, "hydrogen" in the explanation of the structural formula means "hydrogen atom (H)". Similarly, "carbon atom (C)" may be referred to as "carbon". In this specification, the term "adjacent groups" refers to two groups bonded to two adjacent atoms (two atoms directly bonded by a covalent bond) in a structural formula.

[0018] In this specification, "Me" is methyl, "Et" is ethyl, "nBu" is n-butyl (normal butyl), "tBu" is t-butyl (tertiary butyl), "iBu" is isobutyl, "secBu" is secondary butyl, "nPr" is n-propyl (normal propyl), "iPr" is isopropyl, "tAm" is t-amyl, "2EH" is 2-ethylhexyl, "tOct" is t-octyl, "Ph" is phenyl, "Mes" is mesityl (2,4,6-trimethylphenyl), "Ad" is 1-adamantyl, "Tf" is trifluoromethanesulfonyl, "TMS" is trimethylsilyl, and "D" is deuterium. In this specification, the organic electroluminescent element may be referred to as an "organic EL element."

[0019] In this specification, the chemical structure or the substituent may be expressed by the number of carbon atoms, but the number of carbon atoms in the case where a substituent is substituted on the chemical structure or where a substituent is further substituted on the substituent means the number of carbon atoms in each of the chemical structure and the substituent, and does not mean the total number of carbon atoms in the chemical structure and the substituent, or the total number of carbon atoms in the substituent and the substituent. For example, "substituent B of carbon number Y substituted with substituent A of carbon number X" means that "substituent B of carbon number Y" is substituted with "substituent A of carbon number X", and the carbon number Y is not the total number of carbon atoms in the substituent A and the substituent B. Also, for example, "substituent B of carbon number Y substituted with substituent A" means that "substituent B of carbon number Y" is substituted with "substituent A (without carbon number limit)", and the carbon number Y is not the total number of carbon atoms in the substituent A and the substituent B.

[0020] This specification describes many structural formulas of aromatic compounds. Although aromatic compounds are described by combining double bonds and single bonds, in reality, since π electrons resonate, a single substance may have multiple equivalent resonance structures in which double bonds and single bonds alternate. In this specification, only one resonance structure is described for each substance, but unless otherwise specified, other resonance structures that are organically equivalent are also included.

[0021] In this specification, the expression "may" is sometimes used, but this has the same meaning as "not doing, or doing".

[0022] <Explanation of rings and substituents> First, the rings and substituents used in the present specification will be described in detail below. In the present specification, the "aryl ring" may be, 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.

[0023] Specific examples of the "aryl ring" include a monocyclic benzene ring, a bicyclic bicyclic bicyclic naphthalene ring, an indene ring, a tricyclic terphenyl ring (m-terphenyl, o-terphenyl, p-terphenyl), a condensed tricyclic acenaphthylene ring, a fluorene ring, a phenalene ring, a phenanthrene ring, an anthracene ring, a condensed tetracyclic triphenylene ring, a pyrene ring, a naphthacene ring, a chrysene ring, a condensed pentacyclic perylene ring, a pentacene ring, etc. In addition, the fluorene ring, the benzofluorene ring, and the indene ring each include a structure in which a fluorene ring, a benzofluorene ring, a cyclopentane ring, etc. are spiro-bonded. The fluorene ring, benzofluorene ring, and indene ring also include those in which two of the two hydrogen atoms of the methylene in the structure are replaced by alkyl such as methyl as the first substituent described below, resulting in a dimethylfluorene ring, dimethylbenzofluorene ring, dimethylindene ring, etc.

[0024] In the present specification, examples of the "heteroaryl ring" include heteroaryl rings having 2 to 30 carbon atoms, preferably heteroaryl rings having 2 to 25 carbon atoms, more preferably heteroaryl rings having 2 to 20 carbon atoms, further preferably heteroaryl rings having 2 to 15 carbon atoms, and particularly preferably heteroaryl rings having 2 to 10 carbon atoms. In addition, examples of the "heteroaryl ring" include heterocycles containing, as ring-constituting atoms other than carbon, 1 to 5 heteroatoms selected from oxygen, sulfur, nitrogen, boron, selenium, phosphorus, and tellurium.

[0025] Specific examples of the "heteroaryl ring" include a pyrrole ring, an oxazole ring, an isoxazole ring, a thiazole ring, an isothiazole ring, an imidazole ring, an oxadiazole ring (such as a furazan ring), a thiadiazole ring, a triazole ring, a tetrazole ring, a pyrazole ring, a pyridine ring, a pyrimidine ring, a pyridazine ring, a pyrazine ring, a triazine ring, an indole ring, an isoindole ring, a 1H-indazole ring, a benzimidazole ring, a benzoxazole ring, a benzothiazole ring, a 1H-benzotriazole ring, a quinoline ring, an isoquinoline ring, a cinnoline ring, a quinazoline ring, a quinoxaline ring, a phthalazine ring, a naphthyridine ring, a purine ring, a pteridine ring, a carbazole ring, an acridine ring, a phenoxathiin ring, a phenoxazine ring, a phenothiazine ring, a phenazine ring, a phenazasiline ring, an indolizine ring, a furan ring, a benzofuran ring, an isobenzofuran ring, a dibenzofuran ring, and a thiophene ring. , benzothiophene ring, dibenzothiophene ring, thianthrene ring, indolocarbazole ring, benzoindolocarbazole ring, dibenzoindolocarbazole ring, naphthobenzofuran ring, dioxin ring, dihydroacridine ring, xanthene ring, thioxanthene ring, dibenzodioxin ring, dioxaboranaphthoanthracene ring (5,9-dioxa-13b-bora-13bH-naphtho[3,2,1-de]anthracene ring, etc.), benzoselenophene ring, Examples of the ring include a phenylene ring, a dibenzoselenophene ring, an azacarbazole ring, an azadibenzothiophene ring, an azadibenzofuran ring, an azadibenzoselenophene ring, an azatriphenylene ring, an imidazoimidazole ring, an indoloindole ring, a benzofurocarbazole ring, a benzothienocarbazole ring, an indenocarbazole ring, a selenophenocarbazole ring, a spiro[fluorene-9,9'-xanthene] ring, a spirobi[silafluorene] ring, etc. In addition, it is also preferable that the dihydroacridine ring, the xanthene ring, and the thioxanthene ring are such that two of the two hydrogen atoms of the methylene in the structure are replaced by alkyl such as methyl as the first substituent described later, to form a dimethyldihydroacridine ring, a dimethylxanthene ring, a dimethylthioxanthene ring, etc.In addition, bicyclic rings such as bipyridine ring, phenylpyridine ring, and pyridylphenyl ring, and tricyclic rings such as terpyridyl ring, bispyridylphenyl ring, and pyridylbiphenyl ring are also included as the "heteroaryl ring". The "heteroaryl ring" also includes a pyran ring.

[0026] In this specification, a substituent may be substituted with a further substituent. For example, a specific substituent may be described as "substituted or unsubstituted". This means that the specific substituent is substituted with at least one further substituent or is not substituted. In the same sense, the term "optionally substituted" may also be used. In this specification, the specific substituent may be referred to as a "first substituent" and the further substituent may be referred to as a "second substituent".

[0027] In this specification, the substituent group Zα consists of the substituents of the substituent group Z and the substituent represented by the formula (A30) described later.

[0028] In the present specification, the substituent group Z is an aryl optionally substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl, cycloalkyl, cyano, and halogen; heteroaryl optionally substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl, cycloalkyl, cyano, and halogen; diarylamino which may be substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl, cycloalkyl, cyano, and halogen (two aryls may be bonded to each other via a linking group); diheteroarylamino optionally substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl, cycloalkyl, cyano, and halogen (two heteroaryls may be bonded to each other via a linking group); arylheteroarylamino which may be substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl, cycloalkyl, cyano, and halogen (aryl and heteroaryl may be bonded to each other via a linking group); diarylboryl optionally substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl, cycloalkyl, cyano, and halogen (two aryls may be bonded via a single bond or a linking group); an alkyl group optionally substituted with at least one group selected from the group consisting of aryl, heteroaryl, cycloalkyl, cyano, and halogen; cycloalkyl optionally substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl, cycloalkyl, cyano, and halogen; alkoxy optionally substituted with at least one group selected from the group consisting of aryl, heteroaryl, cycloalkyl, cyano, and halogen; aryloxy optionally substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl, cycloalkyl, cyano, and halogen; an arylthio group 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; Consists of substituted silyl, cyano, and halogen. The second substituent aryl in each group of the substituent group Z may be further substituted with an aryl, heteroaryl, alkyl, cycloalkyl, cyano, or halogen; similarly, the second substituent heteroaryl may be substituted with an aryl, heteroaryl, alkyl, cycloalkyl, cyano, or halogen.

[0029] In the present specification, when referring to a "substituent", the type of the substituent is not particularly limited, but unless otherwise specified, it may be any group selected from the substituent group Z. For example, when a group that is "substituted or unsubstituted" is substituted, the group may be substituted with at least one group selected from the substituent group Z.

[0030] In this specification, "aryl" is, for example, aryl having 6 to 30 carbon atoms, and preferably aryl having 6 to 20 carbon atoms, aryl having 6 to 16 carbon atoms, aryl having 6 to 12 carbon atoms, or aryl having 6 to 10 carbon atoms.

[0031] Specific examples of "aryl" include monovalent groups obtained by removing one hydrogen from the above-mentioned "aryl ring". For example, the monocyclic ring system phenyl, the bicyclic ring system biphenylyl (2-biphenylyl, 3-biphenylyl, or 4-biphenylyl), the fused bicyclic ring system naphthyl (1-naphthyl or 2-naphthyl), the tricyclic ring system terphenylyl (m-terphenyl-2'-yl, m-terphenyl-4'-yl, m-terphenyl-5'-yl, o-terphenyl-3'-yl, o-terphenyl-4'-yl, p-terphenyl-2'-yl, m-terphenyl-2-yl, m-terphenyl-3-yl, m-terphenyl-4-yl, o-terphenyl-2-yl, o-terphenyl-3-yl, o-terphenyl-4-yl, p-terphenyl-2-yl, p-terphenyl-3-yl, or p-terphenyl-4-yl), the fused tricyclic ring system acenaphthylene-(1-, 3-, 4-, or 5- -)yl, fluoren-(1-, 2-, 3-, 4-, or 9-)yl, phenalen-(1- or 2-)yl, phenanthrene-(1-, 2-, 3-, 4-, or 9-)yl, or anthracene-(1-, 2-, or 9-)yl, the tetracyclic ring system quaterphenylyl (5'-phenyl-m-terphenyl-2-yl, 5'-phenyl-m-terphenyl-3-yl, 5'-phenyl -m-terphenyl-4-yl, or m-quaterphenyl), fused tetracyclic ring systems such as triphenylene-(1- or 2-)yl, pyrene-(1-, 2-, or 4-)yl, or naphthacene-(1-, 2-, or 5-)yl, or fused pentacyclic ring systems such as perylene-(1-, 2-, or 3-)yl, or pentacene-(1-, 2-, 5-, or 6-)yl. Other examples include monovalent groups of spirofluorene.

[0032] The aryl as the second substituent also includes a structure in which the aryl is substituted with at least one group selected from the group consisting of aryl such as phenyl (specific examples are the groups described above), alkyl such as methyl (specific examples are the groups described below), and cycloalkyl such as cyclohexyl or adamantyl (specific examples are the groups described below). An example of such a group is a group in which the 9-position of fluorenyl as the second substituent is substituted with an aryl such as phenyl, an alkyl such as methyl, or a cycloalkyl such as cyclohexyl or adamantyl.

[0033] The "arylene" is, for example, an arylene having 6 to 30 carbon atoms, and preferably an arylene having 6 to 20 carbon atoms, an arylene having 6 to 16 carbon atoms, an arylene having 6 to 12 carbon atoms, or an arylene having 6 to 10 carbon atoms. Specific examples of "arylene" include divalent groups obtained by removing one hydrogen from the above-mentioned "aryl" (monovalent group).

[0034] The "heteroaryl" is, for example, a heteroaryl having 2 to 30 carbon atoms, and preferably a heteroaryl having 2 to 25 carbon atoms, a heteroaryl having 2 to 20 carbon atoms, a heteroaryl having 2 to 15 carbon atoms, or a heteroaryl having 2 to 10 carbon atoms. The "heteroaryl" contains, as a ring-constituting atom other than carbon, one or more heteroatoms selected from oxygen, sulfur, nitrogen, etc., and preferably 1 to 5 heteroatoms.

[0035] Specific examples of the "heteroaryl" include monovalent groups obtained by removing one hydrogen atom from the above-mentioned "heteroaryl ring". For example, pyrrolyl, oxazolyl, isoxazolyl, thiazolyl, isothiazolyl, imidazolyl, oxadiazolyl, thiadiazolyl, triazolyl, tetrazolyl, pyrazolyl, pyridyl, pyrimidinyl, pyridazinyl, pyrazinyl, triazinyl, indolyl, isoindolyl, 1H-indazolyl, benzimidazolyl, benzoxazolyl, benzothiazolyl, 1H-benzotriazolyl, quinolinyl, isoquinolinyl, cinnolinyl, quinazolinyl, quinoxalinyl, phenanthrolinyl, phthalazinyl, naphthyridinyl, purinyl, pteridinyl, carbazolyl, acridinyl, phenoxathiinyl, phenoxazinyl, phenothiazinyl, phenazinyl, phenazasilinyl, indolizinyl, furanyl, benzofuranyl, isobenzofuranyl, dibenzofuranyl, naphthobenzofuranyl, thienyl, benzothienyl, isobenzothienyl, dibenzothienyl, naphthobenzothienyl, monovalent groups of benzophosphole oxide rings, monovalent groups of dibenzophosphole oxide rings, furazanyl, thianthrenyl, indolocarbazolyl, benzoindolocarbazolyl, dibenzoindolocarbazolyl, imidazolinyl, oxazolinyl, etc. Other examples include monovalent groups of spiro[fluorene-9,9'-xanthene], monovalent groups of spirobi[silafluorene], and monovalent groups of benzoselenophene.

[0036] The heteroaryl as the second substituent also includes a structure in which the heteroaryl is substituted with at least one group selected from the group consisting of aryl such as phenyl (specific examples are the groups described above), alkyl such as methyl (specific examples are the groups described below), and cycloalkyl such as cyclohexyl or adamantyl (specific examples are the groups described below). An example of such a group is a group in which the 9-position of the carbazolyl as the second substituent is substituted with an aryl such as phenyl, an alkyl such as methyl, or a cycloalkyl such as cyclohexyl or adamantyl. In addition, the heteroaryl as the second substituent also includes groups in which a nitrogen-containing heteroaryl such as pyridyl, pyrimidinyl, triazinyl, or carbazolyl is further substituted with phenyl or biphenylyl.

[0037] The "heteroarylene" is, for example, a heteroarylene having 2 to 30 carbon atoms, and preferably a heteroarylene having 2 to 25 carbon atoms, a heteroarylene having 2 to 20 carbon atoms, a heteroarylene having 2 to 15 carbon atoms, or a heteroarylene having 2 to 10 carbon atoms. In addition, the "heteroarylene" is, for example, a divalent group such as a heterocycle containing, in addition to carbon, 1 to 5 heteroatoms selected from oxygen, sulfur, and nitrogen as ring-constituting atoms. Specific examples of "heteroarylene" include divalent groups obtained by removing one hydrogen from the above-mentioned "heteroaryl" (monovalent group).

[0038] The term "diarylamino" refers to an amino substituted with two aryls, and the details of the aryls can be found in the above description of the "aryl". The term "diheteroarylamino" refers to an amino group substituted with two heteroaryls. For details of this heteroaryl, the above description of "heteroaryl" can be cited. The "arylheteroarylamino" is an amino group substituted with an aryl and a heteroaryl, and the details of the aryl and the heteroaryl can be found in the above descriptions of the "aryl" and the "heteroaryl".

[0039] The two aryls in the diarylamino as the first substituent may be bonded to each other via a linking group, the two heteroaryls in the diheteroarylamino as the first substituent may be bonded to each other via a linking group, and the aryl and heteroaryl in the arylheteroarylamino as the first substituent may be bonded to each other via a linking group. Here, the expression "bonded via a linking group" means that, for example, the two phenyls in diphenylamino form a bond with a linking group as shown below. This explanation also applies to diheteroarylamino and arylheteroarylamino formed by aryl and heteroaryl.

[0040] [ka]

[0041] Specific examples of the linking group include >O and >NR X ,>C(-R X )2, -C(-R X )=C(-R X )-, >Si(-R X )2, >S, >CO, >CS, >SO, >SO2, >SeO, >SeO2, >PO, >B(-R X ), and >Se. X are each independently an alkyl, cycloalkyl, aryl, or heteroaryl, which may be substituted with an alkyl, cycloalkyl, aryl, or heteroaryl. X )2, -C(-R X )=C(-R X )-, >Si(-R X )2 The two R X is a single bond or a linking group X Y They may be bonded to each other via X to form a ring. Y As for >O, >NR Y ,>C(-R Y )2, >Si(-R Y )2, >S, >CO, >CS, >SO, >SO2, and >Se, and R Yare each independently alkyl, cycloalkyl, aryl, or heteroaryl, which may be substituted with alkyl, cycloalkyl, aryl, or heteroaryl, provided that X Y >C(-R Y )2 and >Si(-R Y )2, two R Y does not bond to form a ring. Further examples of the linking group include alkenylene. Any hydrogen of the alkenylene can be independently R 2X and R 2X are each independently an alkyl, a cycloalkyl, a substituted silyl, an aryl, or a heteroaryl, which may be substituted with an alkyl, a cycloalkyl, a substituted silyl, or an aryl. X )=C(-R X )- Two R's X may be bonded together to form an aryl ring (such as a benzene ring) or a heteroaryl ring together with the C=C to which they are attached. That is, -C(-R X )=C(-R X )- may be arylene (such as 1,2-phenylene) or heteroarylene.

[0042] In addition, when the term "diarylamino", "diheteroarylamino", or "arylheteroarylamino" is used in this specification, unless otherwise specified, it is assumed that the following explanation is added: "the two aryls of the diarylamino may be bonded to each other via a linking group", "the two heteroaryls of the diheteroarylamino may be bonded to each other via a linking group", and "the aryl and heteroaryl of the arylheteroarylamino may be bonded to each other via a linking group", respectively.

[0043] "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 of -CR=CR-, R of >NR, R of >B(-R), R of >C(-R)2, and R of >Si(-R) are aryl, heteroaryl, diarylamino, alkyl, alkenyl, alkynyl, cycloalkyl, alkoxy, or aryloxy, and at least one hydrogen in the R may be further substituted with aryl, heteroaryl, alkyl, alkenyl, alkynyl, or cycloalkyl. In addition, two adjacent R may be bonded to each other to form a ring, forming a cycloalkylene, arylene, or heteroarylene. For details of the substituents listed here, the explanations of "aryl", "arylene", "heteroaryl", "heteroarylene", and "diarylamino" above, and the explanations of "alkyl", "alkenyl", "alkynyl", "cycloalkyl", "cycloalkylene", "alkoxy", and "aryloxy" below can be cited. In addition, when the term "diarylboryl" is used simply in this specification, unless otherwise specified, it is assumed that the explanation that "the two aryls of the diarylboryl may be bonded to each other via a single bond or a linking group" is added.

[0044] The "alkyl" may be either straight chain or branched chain, for example, straight chain alkyl having 1 to 24 carbon atoms or branched chain alkyl having 3 to 24 carbon atoms, and preferably alkyl having 1 to 18 carbon atoms (branched chain alkyl having 3 to 18 carbon atoms), alkyl having 1 to 12 carbon atoms (branched chain alkyl having 3 to 12 carbon atoms), alkyl having 1 to 6 carbon atoms (branched chain alkyl having 3 to 6 carbon atoms), alkyl having 1 to 5 carbon atoms (branched chain alkyl having 3 to 5 carbon atoms), alkyl having 1 to 4 carbon atoms (branched chain alkyl having 3 to 4 carbon atoms), etc.

[0045] Specific examples of "alkyl" include methyl, ethyl, n-propyl, isopropyl, 1-ethyl-1-methylpropyl, 1,1-diethylpropyl, 1,1,2-trimethylpropyl, 1,1,2,2-tetramethylpropyl, 1-ethyl-1,2,2-trimethylpropyl, n-butyl, isobutyl, s-butyl, t-butyl, 2-ethylbutyl, 1,1-dimethylbutyl, 3,3-dimethylbutyl, 1,1-diethylbutyl, 1-ethyl-1-methylbutyl, 1-propyl-1-methylbutyl, 1,1,3-trimethylbutyl, 1-ethyl-1,3-dimethylbutyl, n-pentyl, isopentyl, neopentyl, t-pentyl (t-amyl), 1-methylpentyl, 2-propylpentyl, 1,1-dimethylpentyl, 1-ethyl-1-methylpentyl, 1-propyl-1 -Methylpentyl, 1-butyl-1-methylpentyl, 1,1,4-trimethylpentyl, n-hexyl, 1-methylhexyl, 2-ethylhexyl, 1,1-dimethylhexyl, 1-ethyl-1-methylhexyl, 1,1,5-trimethylhexyl, 3,5,5-trimethylhexyl, n-heptyl, 1-methylheptyl, 1-hexylheptyl, 1,1-dimethylheptyl, 2,2-dimethylhexyl Examples of the alkyl groups include methylheptyl, 2,6-dimethyl-4-heptyl, n-octyl, t-octyl (1,1,3,3-tetramethylbutyl), 1,1-dimethyloctyl, n-nonyl, n-decyl, 1-methyldecyl, n-undecyl, n-dodecyl, n-tridecyl, n-tetradecyl, n-pentadecyl, n-hexadecyl, n-heptadecyl, n-octadecyl, and n-eicosyl.

[0046] An "alkylene" is a divalent group obtained by removing any hydrogen from an "alkyl", such as methylene, ethylene, or propylene.

[0047] For "alkenyl", the explanation of "alkyl" above can be referred to, and it is a group in which a C--C single bond in the "alkyl" structure is replaced with a C=C double bond, and also includes groups in which not only one but two or more single bonds are replaced with double bonds (also called alkadiene-yl or alkatriene-yl).

[0048] 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, further preferably alkenyl having 2 to 6 carbon atoms, and particularly preferably alkenyl having 2 to 4 carbon atoms. Preferred alkenyls are vinyl, 1-propenyl, 2-propenyl, 1-butenyl, 2-butenyl, 3-butenyl, 1-pentenyl, 2-pentenyl, 3-pentenyl, 4-pentenyl, 1-hexenyl, 2-hexenyl, 3-hexenyl, 4-hexenyl, or 5-hexenyl.

[0049] "Alkenylene" is a divalent group obtained by removing any hydrogen from "alkenyl", and examples include vinylene.

[0050] For "alkynyl", the explanation of "alkyl" above can be referred to, and it is a group in which the C--C single bond in the "alkyl" structure is replaced with a C≡C triple bond, and also includes groups in which not only one but two or more single bonds are replaced with triple bonds (also called alkadiyn-yl or alkatriyn-yl).

[0051] The "cycloalkyl" is, for example, cycloalkyl having 3 to 24 carbon atoms, and preferably cycloalkyl having 3 to 20 carbon atoms, cycloalkyl having 3 to 16 carbon atoms, cycloalkyl having 3 to 14 carbon atoms, cycloalkyl having 3 to 12 carbon atoms, cycloalkyl having 5 to 10 carbon atoms, cycloalkyl having 5 to 8 carbon atoms, cycloalkyl having 5 to 6 carbon atoms, or cycloalkyl having 5 carbon atoms.

[0052] Specific examples of "cycloalkyl" include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl, or alkyl (particularly methyl) substituted derivatives of these having 1 to 5 or 1 to 4 carbon atoms, bicyclo[1.1.0]butyl, bicyclo[1.1.1]pentyl, bicyclo[2.1.0]pentyl, bicyclo[2.1.1]hexyl, bicyclo[3.1.0]hexyl, bicyclo[2.2.1]heptyl (norbornyl), bicyclo[2.2.2]octyl, adamantyl, diamantyl, decahydronaphthalenyl, and decahydroazulenyl.

[0053] "Cycloalkylene" is, for example, cycloalkylene having 3 to 24 carbon atoms, and preferably cycloalkylene having 3 to 20 carbon atoms, cycloalkylene having 3 to 16 carbon atoms, cycloalkylene having 3 to 14 carbon atoms, cycloalkylene having 3 to 12 carbon atoms, cycloalkylene having 5 to 10 carbon atoms, cycloalkylene having 5 to 8 carbon atoms, cycloalkylene having 5 to 6 carbon atoms, cycloalkylene having 5 carbon atoms, or the like. A specific example of the "cycloalkylene" is a structure in which one hydrogen is removed from the above-mentioned "cycloalkyl" (monovalent group) to form a divalent group.

[0054] "Cycloalkenyl" refers to a group having a structure in which at least one pair of single bonds between two carbons in the above-mentioned "cycloalkyl" is a double bond (for example, a group in which -CH2-CH2- is replaced with -CH=CH-), and does not fall under the category of aryl. Specific examples include 1-cyclohexenyl and 1-cyclopentenyl.

[0055] "Alkoxy" is a group represented by "Alk-O-(Alk is alkyl)". For details of the alkyl, the above explanation of "alkyl" can be cited.

[0056] "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.

[0057] The "substituted silyl" is, for example, a silyl substituted with at least one of an aryl, an alkyl, and a cycloalkyl, and is preferably a triarylsilyl, a trialkylsilyl, a tricycloalkylsilyl, a dialkylcycloalkylsilyl, or an alkyldicycloalkylsilyl.

[0058] The term "triarylsilyl" refers to a silyl group substituted with three aryl groups. For details of the aryl groups, see the above description of the "aryl". Specific "triarylsilyl" includes, for example, triphenylsilyl, diphenylmononaphthylsilyl, monophenyldinaphthylsilyl, trinaphthylsilyl, and the like.

[0059] The term "trialkylsilyl" refers to a silyl group substituted with three alkyl groups. For details of this alkyl, see the above description of "alkyl." Specific examples of "trialkylsilyl" include trimethylsilyl, triethylsilyl, tri-n-propylsilyl, triisopropylsilyl, tri-n-butylsilyl, triisobutylsilyl, tri-s-butylsilyl, tri-t-butylsilyl, ethyldimethylsilyl, n-propyldimethylsilyl, isopropyldimethylsilyl, n-butyldimethylsilyl, isobutyldimethylsilyl, s-butyldimethylsilyl, t-butyldimethylsilyl, methyldiethylsilyl, n-propyldiethylsilyl, isopropyldiethylsilyl, n-butyldiethylsilyl, s-butyldiethylsilyl, t-butyldiethylsilyl, methyldi-n-propylsilyl, ethyldi-n-propylsilyl, n-butyldi-n-propylsilyl, s-butyldi-n-propylsilyl, t-butyldi-n-propylsilyl, methyldiisopropylsilyl, ethyldiisopropylsilyl, n-butyldiisopropylsilyl, s-butyldiisopropylsilyl, and t-butyldiisopropylsilyl.

[0060] The term "tricycloalkylsilyl" refers to a silyl group substituted with three cycloalkyl groups. For details of this cycloalkyl, see the above description of "cycloalkyl." Specific "tricycloalkylsilyl" includes, for example, tricyclopentylsilyl or tricyclohexylsilyl.

[0061] The "dialkylcycloalkylsilyl" is a silyl group substituted with two alkyls and one cycloalkyl. For details of the alkyl and cycloalkyl, see the above descriptions of "alkyl" and "cycloalkyl".

[0062] The term "alkyldicycloalkylsilyl" refers to a silyl group substituted with one alkyl and two cycloalkyl. For details of the alkyl and cycloalkyl, see the above descriptions of "alkyl" and "cycloalkyl".

[0063] "Halogen" is fluorine, chlorine, bromine or iodine, preferably fluorine, chlorine or bromine, more preferably fluorine or chlorine, even more preferably fluorine.

[0064] When cyano or halogen is substituted, it is also preferable that all or a part of hydrogen in the aryl or heteroaryl in the structure is replaced with cyano or halogen.

[0065] The substituent represented by formula (A30) has the following structure. [ka]

[0066] In formula (A30), Ak is hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted cycloalkyl, or substituted or unsubstituted cycloalkenyl, in which at least one -CH2- in the alkyl, cycloalkyl, and cycloalkenyl may be replaced by -O- or -S-; R Ak is a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted alkyl, or a substituted or unsubstituted cycloalkyl; R Ak may be bonded to Ak via a linking group or a single bond, and * indicates the bonding position.

[0067] In formula (A30), since Ak is the above-mentioned substituent, it does not conjugate with the unshared electron pair on N, so that the unshared electron pair can be conjugated with the π electron of the bonded destination, and a larger wavelength shift is possible compared to when an aryl or the like is present at the same position. The same applies to the influence on the multiple resonance effect, and a larger improvement in thermally activated delayed fluorescence (TADF) properties is possible.

[0068] 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, even more preferably aryl which may be substituted with alkyl, and particularly preferably phenyl which may be substituted with methyl.

[0069] In formula (A30), Ak is preferably an alkyl group having 1 to 6 carbon atoms or a cycloalkyl group having 3 to 14 carbon atoms, preferably an alkyl group having 1 to 4 carbon atoms or a cycloalkyl group having 3 to 8 carbon atoms, more preferably an alkyl group having 1 to 4 carbon atoms, and even more preferably methyl.

[0070] R Ak and Ak may be the same or different, and are preferably different.

[0071] 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.

[0072] [ka] In the above formulas, * indicates a bonding position.

[0073] [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-, or -Se-, for example, the following structure. In addition, R of -CHR-CHR-, R of -CR2-CR2-, R of -CR=CR-, R of -N(-R)-, R of -C(-R)2-, R of -B(-R)-, and R of -Si(-R)2- are each independently hydrogen, aryl which may be substituted with alkyl or cycloalkyl, heteroaryl which may be substituted with alkyl or cycloalkyl, alkyl which may be substituted with cycloalkyl, alkenyl which may be substituted with alkyl or cycloalkyl, alkynyl which may be substituted with alkyl or cycloalkyl, or cycloalkyl which may be substituted with alkyl or cycloalkyl. In addition, two adjacent Rs may be bonded to each other to form a ring, forming a cycloalkylene, arylene, or heteroarylene.

[0074] [ka]

[0075] As the bonding group, a single bond and -CR=CR-, -N(-R)-, -O-, -S-, -C(-R)2-, -Si(-R)2-, and -Se- as linking groups are preferred, a single bond and -CR=CR-, -N(-R)-, -O-, -S-, and -C(-R)2- as linking groups are more preferred, a single bond and -CR=CR-, -N(-R)-, -O-, and -S- as linking groups are even more preferred, and a single bond is most preferred.

[0076] The position where two R are bonded by the bonding group is not particularly limited as long as it is a bondable position, but it is preferable that they are bonded at the most adjacent positions. For example, when the two groups are phenyl, it is preferable that they are bonded at the ortho (2nd) positions based on the bonding position (1st position) of "C" or "Si" in the phenyl (see the above structural formula).

[0077] <Stereoisomers, etc.> The polycyclic aromatic compound of the present invention may exist as an enantiomer or diastereomer depending on the type of substituents, etc., but regardless of the structural formula described, any stereoisomer in any pure form, any mixture of stereoisomers, racemates, etc. are all intended to be included within the scope of the present invention.

[0078] <1. Polycyclic aromatic compounds> <Overall structure> It has already been found that polycyclic aromatic compounds in which aromatic rings are linked by heteroatoms such as boron, nitrogen, oxygen, and sulfur have a large HOMO-LUMO gap (band gap Eg in thin films). This is because six-membered rings containing heteroatoms have low aromaticity, suppressing the decrease in the HOMO-LUMO gap associated with the expansion of the conjugated system. It has also been found that the HOMO-LUMO gap can be changed arbitrarily depending on the type and linking method of the heteroatom. This is thought to be because the HOMO and LUMO energies can be moved arbitrarily depending on the spatial extent and energy of the unoccupied orbitals or lone pairs of the heteroatoms.

[0079] In these polycyclic aromatic compounds, the excited states of SOMO1 and SOMO2 are localized on each atom due to electronic perturbation of the heteroatoms, and the half-width of the fluorescence emission peak is narrow, and when used as a dopant in an organic electroluminescence device, emission with high color purity can be obtained. For the same reason, ΔE S1T1 The thermally activated delayed fluorescence is exhibited by the compound having a small diameter, and thus high efficiency can be obtained when the compound is used as an emitting dopant in an organic electroluminescence device. Furthermore, by introducing a substituent, the HOMO and LUMO energies can be adjusted as desired, making it possible to optimize the ionization potential and electron affinity depending on the surrounding materials.

[0080] In the present invention, it has been found that polycyclic aromatic compounds having a structure composed of one or more structural units represented by formula (1) having substituents at specific positions, in which aromatic rings such as benzene rings are linked by hetero elements such as boron and nitrogen, enable the production of organic electroluminescent devices having a longer lifetime than polycyclic aromatic compounds having a similar structure.

[0081] 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)".

[0082] [ka] In formula (1), R c1 ~R c4 At least two of are each independently a substituent. The symbols in each formula are explained in detail below.

[0083] <R c1 ~R c4 > In formula (1), R c1 ~R c4 At least two of R are independently a substituent and the others are hydrogen. c1 ~R c4 It was found that the emission wavelength can be adjusted by introducing at least two substituents into R. c1 ~R c4 It has been found that by introducing at least two substituents into the compound, it is possible to obtain a compound that enables the production of a device having a longer life.

[0084] R c1 ~R c4 It is more preferable that two of R are each independently a substituent and the other two are hydrogen. c1 ~R c4 For example, R c1 and R c3 , R c2 and R c3 , R c1 and R c2 , or R c1 and R c4 is a substituent, and R c1 and R c3 , R c2 and R c3 , or R c1 and R c2 is preferably a substituent, and R c1 and R c3 or R c2 and R c3 is more preferably a substituent, and R c1 and R c3 is particularly preferably a substituent.

[0085] 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 c4Among them, at least one is preferably a substituted or unsubstituted aryl or a substituted or unsubstituted heteroaryl. At this time, at least one is more preferably an aryl which may be substituted with an alkyl, and even more preferably a phenyl which may be substituted with methyl or t-butyl. A structure in which an aryl ring or a heteroaryl ring in the substituent is condensed with a cycloalkane as described later is also preferred. In this case, a structure in which a partial structure represented by the formula (B11) or formula (B12) described later is formed is particularly preferred.

[0086] R c1 ~R c4 At least two of may be the same or different. For example, examples of combinations of two substituents are as follows: Phenyl + Phenyl pt-Butylphenyl + Phenyl pt-Butylphenyl + pt-Butylphenyl Phenyl substituted with a group represented by formula (B11) + phenyl Phenyl substituted with a group represented by formula (B11) + Phenyl substituted with a group represented by formula (B11) t-Butyl + Phenyl

[0087] R c1 , R c2 , and R c3 It is preferable that two of R are phenyl, pt-butylphenyl, or phenyl substituted with a group represented by formula (B11). c1 is phenyl or pt-butylphenyl, and R c3 is more preferably phenyl, pt-butylphenyl, or phenyl substituted with a group represented by formula (B11), and R c1 and R c3 More preferably, both are phenyl or pt-butylphenyl.

[0088] <R a1 ~R a3 > In formula (1), Ra1 ~R a3 are each independently hydrogen or a substituent. R a1 ~R a3 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, further preferably substituted or unsubstituted alkyl, and particularly preferably unsubstituted alkyl. Examples of preferred substituents described below may also be referred to. a1 ~R a3 When a plurality of groups among the above are substituents, the substituents may be the same or different.

[0089] R a1 ~R a3 In R a2 is hydrogen or a substituent, and R a1 and R a3 Preferably, each R is hydrogen. a2 When is a substituent, the substituent is preferably substituted or unsubstituted alkyl, substituted or unsubstituted cycloalkyl, or substituted or unsubstituted diarylamino, more preferably alkyl, or cycloalkyl which may be substituted with alkyl, and further preferably methyl or t-butyl.

[0090] R a1 ~R a3 Preferably, none of R is a group that does not contain an aryl or heteroaryl. a1 ~R a3 By not including such groups in R, the molecular orientation is improved, leading to high efficiency of the device. a1 ~R a3 are each preferably independently hydrogen or unsubstituted alkyl, R a1 and R a3 is hydrogen and R a2 It is more preferred that is hydrogen or a substituent.

[0091] <R b1 ~R b4 > In formula (1), R b1 ~R b4 are each independently hydrogen or a substituent. R b1 ~R b4 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, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, or substituted or unsubstituted diarylamino. Examples of preferred substituents described below can also be referred to. b1 ~R b4 When a plurality of groups among the above are substituents, the substituents may be the same or different.

[0092] R b1 ~R b4 In R b2 or R b3 is preferably hydrogen or a substituent and the others are each preferably 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, diphenylamino which may be substituted with t-butyl or phenyl, or carbazolyl which may be substituted with t-butyl or phenyl, and even more preferably t-butyl, diphenylamino which may be substituted with t-butyl or phenyl. b2 and R b3Also preferred is a structure in which R is bonded to the carbon atom to form a cycloalkene. This structure corresponds to a structure in which a cycloalkane is condensed to the 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 later.

[0093] <l> In formula (1), L is >NR NL , >O, >C(-R CL )2, >Si(-R IL )2, >S, or >Se, and R NL , R CL , and R IL are each independently hydrogen, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted alkyl, or substituted or unsubstituted cycloalkyl; CL may be bonded to each other to form a ring, and two R IL may be bonded to each other to form a ring. When referring to "substituted or unsubstituted", the substituent is preferably alkyl or aryl. R CL is preferably methyl. L is >O, >C(-R CL )2, or >S. In particular, it is preferable that L is >O or >S from the viewpoint of chemical stability of the compound, and it is more preferable that L is >O from the viewpoint of luminous efficiency when used in a device.

[0094] <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.

[0095] <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.

[0096] 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.

[0097] 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. CX is preferably methyl or phenyl.

[0098] 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.

[0099] X 1 and X 2 are all >NR NX In this case, R NX are 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, 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, more preferably substituted or unsubstituted phenyl, substituted or unsubstituted biphenylyl, R is more preferably substituted or unsubstituted terphenylyl, 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 alkyl or cycloalkyl, biphenylyl which may be substituted with an alkyl or cycloalkyl, or dibenzofuranyl which may be substituted with an alkyl or cycloalkyl, and even more preferably phenyl which may be substituted with an alkyl or cycloalkyl, or 2-biphenylyl which may be substituted with an alkyl or cycloalkyl. NX By selecting the above, it is possible to obtain a compound which has higher heat resistance and can realize an organic EL device having 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.

[0100] X 1 and X 2 All are >NR NX When two R NX may be the same or different.

[0101] <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. a3 and / or R b1 , or R a1 and / or R c4 may be bonded to

[0102] R NX , R CX and R IX Examples 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-. Among these, -CH=CH-, -CR=CR-, -N(-R)-, -O-, -S-, and -C(-R)- 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-", the R of "-CR2-CR2-", the R of "-CR=CR-", the R of "-N(-R)-", the R of "-C(-R)2-", the R of "-B(-R)-", and the R of "-Si(-R)2-" are each independently hydrogen, aryl which may be substituted with alkyl or cycloalkyl, heteroaryl which may be substituted with alkyl or cycloalkyl, alkyl which may be substituted with alkyl or cycloalkyl, alkenyl which may be substituted with alkyl or cycloalkyl, alkynyl which may be substituted with alkyl or cycloalkyl, or cycloalkyl which may be substituted with alkyl or cycloalkyl. In addition, two Rs bonded to the same element may be bonded to each other to form a ring. Furthermore, two adjacent Rs may be bonded to each other to form a cycloalkylene ring, an arylene ring, and a heteroarylene ring. These rings may also be substituted with alkyl or cycloalkyl.

[0103] >NR NX R in NX R a3 , R b1 , R a1 , or R c4 Examples of the condensed ring formed by bonding with are carbazole rings (R NX is bonded with a single bond), phenoxazine ring (R is phenyl NX -O- bond), phenothiazine ring (R is phenyl NX -S- bond), or an acridone ring (R NX Examples include the -C(=O)- bond.

[0104] Furthermore, the following partial structure (A10) may be formed by the above linkage. [ka]

[0105] 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 the two * positions are bonded to one of the two rings to which X is bonded, and the two * positions are bonded to the other ring. 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 of such structures may be one or two (preferably one).

[0106] 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 R A3 and R A4 ) are preferably bonded to each other via a linking group or a single bond, and R A1 and R A4 are more preferably bonded to each other by 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-. As the divalent group formed by bonding to each other, a straight chain alkylene having 2 to 5 carbon atoms is preferred, a straight chain alkylene having 3 or 4 carbon atoms is more preferred, and a straight chain alkylene having 4 carbon atoms (-(CH2)4-) is even more preferred. It is particularly preferred that the straight chain alkylene having 4 carbon atoms (-(CH2)4-) is unsubstituted.

[0107] The remaining R that is not involved in the linkage via a linking group or single bond A1 ~R A4 are each independently preferably hydrogen or an optionally substituted alkyl, more preferably an optionally substituted alkyl having 1 to 6 carbon atoms, further preferably an unsubstituted alkyl having 1 to 6 carbon atoms, and most preferably methyl. That is, as the partial structure represented by formula (A10), a structure represented by the following formula (A11) is preferable.

[0108] [ka] In formula (A11), Me is methyl, and is bonded to one of the two rings to which X is bonded at the two * positions and to the other ring at the ** position.

[0109] <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). An example of a polycyclic aromatic compound having a structure consisting of one of the above structural units is a polycyclic aromatic compound represented by formula (1). An example of a polycyclic aromatic compound having a structure consisting of two or more structural units represented by formula (1) is a compound corresponding to a multimer of a polycyclic aromatic compound represented by the formula 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 In addition, any ring (R a1 ~R a3 , R b1 ~R b4 , or R c1 ~R c4 The structural units may be bonded in such a manner that the benzene rings to which the structural units are bonded are condensed with each other. The structural units may also be bonded in such a manner that a plurality of the structural units are bonded to each other via a linking group such as a single bond, an alkylene having 1 to 3 carbon atoms, a phenylene, or a naphthylene. Among these, the structural units are preferably bonded to each other so as to share a ring. 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.

[0110] <Preferred Substituents> In polycyclic aromatic compounds used as emitting dopants (and in other compounds used as dopants), the tertiary alkyl represented by the following formula (tR) is one of the particularly preferred substituents containing "alkyl". This is because such bulky substituents increase the intermolecular distance, thereby improving the luminescence quantum yield (PLQY). In addition, a substituent in which the tertiary alkyl represented by formula (tR) is substituted with another substituent as a second substituent is also preferred. Specifically, diarylamino substituted with a tertiary alkyl represented by formula (tR), carbazolyl (preferably N-carbazolyl) substituted with a tertiary alkyl represented by formula (tR), or benzocarbazolyl (preferably N-benzocarbazolyl) substituted with a tertiary alkyl represented by formula (tR) are mentioned. Substitution of the group of formula (tR) on diarylamino, carbazolyl and benzocarbazolyl includes examples in which some or all of the hydrogen atoms on the aryl ring or benzene ring in these groups are replaced with a group of formula (tR).

[0111] [ka]

[0112] In the formula (tR), R a , R b , and R c are each independently an alkyl group having 1 to 24 carbon atoms, any -CH2- in the alkyl group may be replaced with -O-, and the group represented by formula (tR) has * as the bonding position.

[0113] R a , R b and R c The "alkyl having 1 to 24 carbon atoms" may be either linear or branched, and examples thereof include linear alkyl having 1 to 24 carbon atoms or branched alkyl having 3 to 24 carbon atoms, alkyl having 1 to 18 carbon atoms (branched alkyl having 3 to 18 carbon atoms), alkyl having 1 to 12 carbon atoms (branched alkyl having 3 to 12 carbon atoms), alkyl having 1 to 6 carbon atoms (branched alkyl having 3 to 6 carbon atoms), and alkyl having 1 to 4 carbon atoms (branched alkyl having 3 to 4 carbon atoms).

[0114] 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.

[0115] R a , R b , and R c Specific examples of alkyl include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, s-butyl, t-butyl, n-pentyl, isopentyl, neopentyl, t-pentyl, n-hexyl, 1-methylpentyl, 4-methyl-2-pentyl, 3,3-dimethylbutyl, 2-ethylbutyl, n-heptyl, 1-methylhexyl, n-octyl, t-octyl, 1-methylheptyl, 2 Examples of the aryl group include n-ethylhexyl, 2-propylpentyl, n-nonyl, 2,2-dimethylheptyl, 2,6-dimethyl-4-heptyl, 3,5,5-trimethylhexyl, n-decyl, n-undecyl, 1-methyldecyl, n-dodecyl, n-tridecyl, 1-hexylheptyl, n-tetradecyl, n-pentadecyl, n-hexadecyl, n-heptadecyl, n-octadecyl, and n-eicosyl.

[0116] Examples of the group represented by the formula (tR) include t-butyl, t-amyl, 1-ethyl-1-methylpropyl, 1,1-diethylpropyl, 1,1-dimethylbutyl, 1-ethyl-1-methylbutyl, 1,1,3,3-tetramethylbutyl, 1,1,4-trimethylpentyl, 1,1,2-trimethylpropyl, 1,1-dimethyloctyl, 1,1-dimethylpentyl, 1,1-dimethylheptyl, 1,1,5-trimethylhexyl, 1-ethyl- Examples include 1-methylhexyl, 1-ethyl-1,3-dimethylbutyl, 1,1,2,2-tetramethylpropyl, 1-butyl-1-methylpentyl, 1,1-diethylbutyl, 1-ethyl-1-methylpentyl, 1,1,3-trimethylbutyl, 1-propyl-1-methylpentyl, 1,1,2-trimethylpropyl, 1-ethyl-1,2,2-trimethylpropyl, 1-propyl-1-methylbutyl, 1,1-dimethylhexyl, etc. Among these, t-butyl and t-amyl are preferred.

[0117] The substituent is also preferably a substituent represented by formula (A30).

[0118] The emission wavelength can be adjusted by the steric hindrance, electron donating property and electron withdrawing property of the structure of the substituent of the compound used as a dopant (assisting dopant or emitting dopant). Preferred are groups represented by the following structural formulas, and more preferred are methyl, t-butyl, t-amyl, t-octyl, neopentyl, adamantyl, phenyl, o-tolyl, p-tolyl, 2,4-xylyl, 2,5-xylyl, 2,6-xylyl, 2,4,6-mesityl, diphenylamino, di-p-tolylamino, bis(p-(t-butyl)phenyl)amino, carbazolyl, 3,6-dimethylcarbazolyl, 3,6-di-t-butyl, Preferred are methyl, t-butyl, t-amyl, t-octyl, neopentyl, adamantyl, phenyl, o-tolyl, 2,6-xylyl, 2,4,6-mesityl, diphenylamino, di-p-tolylamino, bis(p-(t-butyl)phenyl)amino, carbazolyl, 3,6-dimethylcarbazolyl, 3,6-di-t-butylcarbazolyl, and tribenzoazepinyl. From the viewpoint of ease of synthesis, larger steric hindrance is preferred for selective synthesis, and specifically, t-butyl, t-amyl, t-octyl, adamantyl, o-tolyl, p-tolyl, 2,4-xylyl, 2,5-xylyl, 2,6-xylyl, 2,4,6-mesityl, di-p-tolylamino, bis(p-(t-butyl)phenyl)amino, 3,6-dimethylcarbazolyl and 3,6-di-t-butylcarbazolyl are preferred.

[0119] In the following structural formulas, * indicates a bond position. [ka]

[0120] [ka]

[0121] [ka]

[0122]

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[0123]

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[0124]

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[0125]

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[0126]

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[0127]

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[0128]

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[0129]

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[0130]

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[0131]

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[0132]

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[0133] The polycyclic aromatic compound having a structure consisting of one or more structural units represented by formula (1) is preferably a structure containing at least one tertiary alkyl (such as t-butyl or t-amyl), neopentyl or adamantyl represented by the above formula (tR), and preferably contains a tertiary alkyl (such as t-butyl or t-amyl) represented by formula (tR). This is because such a bulky substituent increases the intermolecular distance, thereby improving the luminescence quantum yield (PLQY). In addition, 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).

[0134] 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]

[0135] The substituent represented by formula (A20) is bonded to two adjacent atoms on the ring of an aryl ring or a heteroaryl ring by two *. 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 may be bonded to each other to form a ring, and at least one of the R of the >NR and the >Si(-R)2 may be bonded to the aryl ring or the heteroaryl ring by a linking group or a single bond; r is an integer from 1 to 4; R A are each independently hydrogen, substituted or unsubstituted alkyl, or substituted or unsubstituted cycloalkyl; A is any other R A and may be bonded to each other via a linking group or a single bond.

[0136] Examples of the above-mentioned substituent include any of the following substituents. [ka]

[0137] In each formula, * may be bonded to two or three consecutive (adjacent) atoms on the ring of any aryl or heteroaryl ring.

[0138] <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.

[0139] The cycloalkane may be a cycloalkane having 3 to 24 carbon atoms. In this case, at least one hydrogen in the cycloalkane may be substituted with an aryl having 6 to 30 carbon atoms, a heteroaryl having 2 to 30 carbon atoms, an alkyl having 1 to 24 carbon atoms, or a cycloalkyl having 3 to 24 carbon atoms, and at least one -CH2- in the cycloalkane may be replaced with -O-.

[0140] 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.

[0141] 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.

[0142] Specific examples of cycloalkanes include cyclopropane, cyclobutane, cyclopentane, cyclohexane, cycloheptane, cyclooctane, cyclononane, cyclodecane, norbornane (bicyclo[2.2.1]heptane), bicyclo[1.1.0]butane, bicyclo[1.1.1]pentane, bicyclo[2.1.0]pentane, bicyclo[2.1.1]hexane, bicyclo[3.1.0]hexane, bicyclo[2.2.2]octane, adamantane, diamantane, decahydronaphthalene, and decahydroazulene, as well as alkyl (particularly methyl) substituted, halogen (particularly fluorine) substituted, and deuterium substituted derivatives of these having 1 to 5 carbon atoms.

[0143] Among the above examples, a structure having at least one substituent on the carbon at the α-position of the cycloalkane (the carbon at the position adjacent to the carbon at the condensation site in the cycloalkane condensed to an aryl ring or heteroaryl ring), as shown in the following structural formula, is preferred, a structure having two substituents on the carbon at the α-position is more preferred, and a structure having two substituents on each of the two α-position carbons (four substituents in total) is even more preferred. Examples of the substituent include an alkyl group having 1 to 5 carbon atoms (particularly methyl), halogen (particularly fluorine), and deuterium. In particular, a structure in which a partial structure represented by the following formula (B11) or (B12) is bonded to adjacent carbon atoms in an aryl ring or heteroaryl ring is preferred, and a structure in which a partial structure represented by the following formula (B11) is bonded is more preferred.

[0144] [ka] In each of formulae (B11) and (B12), * indicates the bonding position.

[0145] The number of cycloalkanes fused to one aryl ring or heteroaryl ring is preferably 1 to 3, more preferably 1 or 2, and even more preferably 1. For example, the following shows an example in which one or more cycloalkanes are fused to one benzene ring (phenyl). * indicates a bonding position, and the position may be any carbon that constitutes a benzene ring and does not constitute a cycloalkane. Cycloalkanes fused to each other as in formula (Cy-1-4) and formula (Cy-2-4) may be fused together. The same applies even if the ring (group) to be fused is an aryl ring or heteroaryl ring other than a benzene ring (phenyl) or if the condensed cycloalkane is a cycloalkane other than cyclopentane or cyclohexane.

[0146] [ka]

[0147] At least one -CH2- in the cycloalkane may be replaced with -O-. For example, the following shows an example in which one or more -CH2- in a cycloalkane fused to one benzene ring (phenyl) are replaced with -O-. The same applies even when the fused ring (group) is an aryl ring or heteroaryl ring other than a benzene ring (phenyl) or when the fused cycloalkane is a cycloalkane other than cyclopentane or cyclohexane.

[0148] [ka]

[0149] The cycloalkane may be substituted with at least one substituent, and the substituent may be any of the substituents selected from the substituent group Z. Among these substituents, alkyl (e.g., alkyl having 1 to 6 carbon atoms) and cycloalkyl (e.g., cycloalkyl having 3 to 14 carbon atoms) are preferred. It is also preferred that any of the hydrogen atoms is replaced with halogen (e.g., fluorine) or deuterium. In addition, when cycloalkyl is substituted, it may be a substitution form that forms a spiro structure, and for example, an example in which a spiro structure is formed in a cycloalkane condensed to one benzene ring (phenyl) is shown below. In each structural formula, * means a benzene ring included in the skeletal structure of the compound when it is a benzene ring, and means a bond that substitutes in the skeletal structure of the compound when it is a phenyl.

[0150] [ka]

[0151] 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 c4 The benzene ring to which R is attached is condensed with a cycloalkane. a1 ~R a3 , R b1 ~R b4 , and R c1 ~R c4 or a group containing an aryl ring or a heteroaryl ring, the aryl ring or the heteroaryl ring is condensed with a cycloalkane.

[0152] As another form of cycloalkane condensation, a polycyclic aromatic compound having a structure consisting of one or more structural units represented by formula (1) can be used, for example, R NX is an aryl fused to a cycloalkane >NR NX An example having the following structure is given.

[0153] In addition, by introducing a cycloalkane structure into a polycyclic aromatic compound having a structure consisting of one or more structural units represented by formula (1), a further decrease in melting point and sublimation temperature can be expected. This means that in sublimation purification, which is almost essential as a purification method for materials for organic devices such as organic EL elements that require high purity, purification can be performed at a relatively low temperature, so that thermal decomposition of the material can be avoided. This is also true for the vacuum deposition process, which is a powerful means for producing organic devices such as organic EL elements, and since the process can be performed at a relatively low temperature, thermal decomposition of the material can be avoided, and as a result, a high-performance organic device can be obtained. In addition, since the solubility in organic solvents is improved by the introduction of a cycloalkane structure, it can also be applied to the production of elements using a coating process. However, the present invention is not particularly limited to these principles.

[0154] <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 the natural abundance ratio. However, all or some of the elements in each structural formula may be present in an amount exceeding the natural abundance ratio (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 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 composed of one or more structural units represented by formula (1).

[0155] <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.

[0156] 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 c4 In particular, the hydrogen in the aryl or heteroaryl may be replaced with deuterium. From the viewpoint of durability, it is also preferable that all or a part of the hydrogen in the polycyclic aromatic compound having a structure composed of one or more structural units represented by formula (1) is deuterated.

[0157] <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.

[0158] [ka]

[0159] [ka]

[0160] [ka]

[0161] [ka]

[0162] [ka]

[0163] [ka]

[0164] [ka]

[0165]

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[0166]

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[0167]

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[0168]

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[0169]

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[0170]

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[0171]

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[0172]

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[0173]

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[0174]

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[0175]

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[0176] [ka]

[0177] [ka]

[0178] <Method of producing polycyclic aromatic compounds> A polycyclic aromatic compound having a structure consisting of one or more structural units represented by formula (1) is basically prepared by first reacting R a1 ~R a3 Benzene ring to which R is attached b1 ~R b4 The benzene ring to which R is attached c1 ~R c4 The condensed ring to which is bonded is treated 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 c1 ~R c4 The condensed ring to which is bonded is treated as a bonding group (Y 1 The final product can be produced by bonding the two groups via a group containing the group (second reaction). In the first reaction, for example, general reactions such as the Buchwald-Hartwig reaction, nucleophilic substitution reaction, and Goldberg amination can be used as amination reactions. In the second reaction, the 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 process of condensing the ring.

[0179] [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.

[0180] 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 metalating a halogen atom (Hal) between Y 1 Halides of Y 1 Aminated halides of Y 1 Alkoxylated compounds of Y 1 and reacting said metal with Y with a reagent selected from the group consisting of aryloxy compounds of 1 and a reaction step of exchanging Y with a Brønsted base by successive electrophilic aromatic substitution reactions. 1 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 (Hal) 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.

[0181] [ka]

[0182] Metalating reagents used in the halogen-metal exchange reaction in the schemes described so far include alkyllithium 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.

[0183] In addition to the above-mentioned reagents, the metallation reagents used in the ortho-metal exchange reactions in the schemes described so far include organic alkali compounds such as lithium diisopropylamide, lithium tetramethylpiperidide, lithium hexamethyldisilazide, potassium hexamethyldisilazide, lithium tetramethylpiperidinylmagnesium chloride-lithium chloride complex, and lithium tri-n-butylmagnesium oxide.

[0184] Furthermore, when alkyllithium is used as the metallation reagent, examples of additives that promote the reaction include N,N,N',N'-tetramethylethylenediamine, 1,4-diazabicyclo[2.2.2]octane, and N,N-dimethylpropyleneurea.

[0185] 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, CoBr3, etc. These Lewis acids supported on solids can also be used.

[0186] In addition, the Bronsted acids used in the schemes explained 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, hydrogen fluoride, etc. In addition, the solid Bronsted acids include Amberlyst (trade name: Dow Chemical), Nafion (trade name: DuPont), zeolite, and Teikacure (trade name: Teika Corporation).

[0187] In addition, 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.

[0188] In addition, solvents used in the schemes described above 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.

[0189] Here, Y 1 However, by changing the raw materials appropriately, it can be Y. 1 Compounds in which is P, P=O, P=S, Al, Ga, As, Si-R or Ge-R can also be synthesized.

[0190] In the above scheme, a Brønsted base or Lewis acid may be used to promote the tandem hetero Friedel-Crafts reaction. 1 trifluoride, Y 1 trichloride, Y 1 Tribromide of Y 1 of 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 above is used, since amines and alcohols are produced as the aromatic electrophilic substitution reaction proceeds, it is often not necessary to use a Brønsted base. However, since the amino and alkoxy groups have low elimination ability, it is effective to use a Lewis acid that promotes their elimination.

[0191] The polycyclic aromatic compound of the present invention also includes compounds in which at least a portion of hydrogen has been replaced with deuterium or compounds in which hydrogen has been replaced with various substituents. Such compounds can be synthesized in the same manner as described above by using a raw material in which the desired position has been deuterized or derivatized.

[0192] <2. Organic devices> The polycyclic aromatic compound of the present invention can be used as a material for an organic device, such as an organic electroluminescent device, an organic field effect transistor, or an organic thin-film solar cell.

[0193] The polycyclic aromatic compound and its multimer according to the present invention can be used as a material for an organic device. The organic device can be, for example, an organic electroluminescent device, an organic field effect transistor, or an organic thin-film solar cell, and is preferably an organic electroluminescent device. The polycyclic aromatic compound according to the present invention is preferably an organic electroluminescent device material, more preferably a material for an emitting layer (light-emitting material), and most preferably a dopant material for the emitting layer.

[0194] <2-1. Organic electroluminescent device> <2-1-1. Structure of organic electroluminescent device> FIG. 1 is a schematic cross-sectional view showing an example of an organic EL element. The organic EL element 100 shown in FIG. 1 has a substrate 101, an anode 102 provided on the substrate 101, a hole injection layer 103 provided on the anode 102, a hole transport layer 104 provided on the hole injection layer 103, an emitting layer 105 provided on the hole transport layer 104, an electron transport layer 106 provided on the emitting layer 105, an electron injection layer 107 provided on the electron transport layer 106, and a cathode 108 provided on the electron injection layer 107.

[0195] 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.

[0196] Not all of the above layers are essential, and the minimum structural unit is a structure consisting of an anode 102, an emitting layer 105, and a cathode 108. The hole injection layer 103, the hole transport layer 104, the electron transport layer 106, and the electron injection layer 107 are layers that may be provided optionally. Each of the above layers may consist of a single layer or multiple layers.

[0197] In addition to the above-mentioned "substrate / anode / hole injection layer / hole transport layer / light-emitting layer / electron transport layer / electron injection layer / cathode" configuration, the layers constituting the organic EL element may be configured as "substrate / anode / hole transport layer / light-emitting layer / electron transport layer / electron injection layer / cathode", "substrate / anode / hole injection ...hole transport layer / light-emitting layer / electron injection layer / cathode", "substrate / anode / hole injection layer / hole transport layer / light-emitting layer / electron injection layer / cathode", or "substrate / anode / hole injection layer / hole transport layer / light-emitting layer / electron transport The configuration may be, for example, "substrate / anode / light-emitting layer / electron transport layer / electron injection layer / cathode", "substrate / anode / hole transport layer / light-emitting layer / electron injection layer / cathode", "substrate / anode / hole transport layer / light-emitting layer / electron transport layer / cathode", "substrate / anode / hole transport layer / light-emitting layer / electron injection layer / cathode", "substrate / anode / hole injection layer / light-emitting layer / electron injection layer / cathode", "substrate / anode / hole injection layer / light-emitting layer / electron transport layer / cathode", "substrate / anode / hole injection layer / light-emitting layer / electron transport layer / cathode", "substrate / anode / light-emitting layer / electron transport layer / cathode", or "substrate / anode / light-emitting layer / electron injection layer / cathode".

[0198] <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 used as a material for forming a light-emitting layer. The light-emitting layer 105 is a layer that emits light by recombining holes injected from the anode 102 and electrons injected from the cathode 108 between electrodes to which an electric field is applied. The material for forming the light-emitting layer 105 may be a compound (light-emitting compound) that is excited and emits light by recombination of holes and electrons, and is preferably a compound that can form a stable thin film shape and shows strong light-emitting (fluorescence) efficiency in a solid state. The polycyclic aromatic compound of the present invention can be used as a material for a light-emitting layer, may be used as a dopant material, or may be used as a host material, but is preferably used as a material for a light-emitting layer, and more preferably used as a dopant material.

[0199] 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 in which no assisting dopant is used.

[0200] Polycyclic aromatic compounds containing a structural unit represented by formula (1) can be used as emitting dopants in TTF elements that utilize the phenomenon of generation of singlet excitons from multiple triplet excitons (triplet-triplet fusion (TTF)).

[0201] In addition, polycyclic aromatic compounds containing the structural unit represented by formula (1) can be used as emitting dopants in TADF elements as "thermally activated delayed fluorescent substances." In "thermally activated delayed fluorescent substances," the energy difference between the lowest excited singlet state and the lowest excited triplet state is reduced, which allows highly efficient reverse intersystem crossing from the lowest excited triplet state, which usually has a low transition probability, to the lowest excited singlet state, resulting in emission from the singlet state (thermally activated delayed fluorescence, TADF). In normal fluorescent emission, 75% of triplet excitons generated by current excitation pass through a thermal deactivation pathway and cannot be extracted as fluorescent light. On the other hand, in TADF, all excitons can be used for fluorescent emission, realizing highly efficient organic electroluminescence elements.

[0202] The light-emitting layer may be a single layer or multiple layers, each of which is 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 in the entire host material or may be contained partially in the host material. As a doping method, the dopant material may be formed by co-evaporation with the host material, but it may also be mixed with the host material in advance and then vapor-deposited at the same time.

[0203] The amount of the host material used varies depending on the type of the host material and may be determined according to the properties of the host material. The amount of the host material used is preferably 50 to 99.999% by mass, more preferably 80 to 99.95% by mass, and even more preferably 90 to 99.9% by mass of the total mass of the materials for the light-emitting layer.

[0204] The amount of the dopant material used varies depending on the type of dopant material, and may be determined according to the characteristics of the dopant material. The amount of the 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, based on the total mass of the material for the light-emitting layer. The above range is preferable in that, for example, concentration quenching can be prevented.

[0205] <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. In the case where a plurality of dopants are combined, specific examples of dopants to be combined with the compound of the present invention are shown below.

[0206] [ka]

[0207] [ka]

[0208] [ka]

[0209] [ka]

[0210] <Host material> Examples of the host material include condensed ring derivatives such as anthracene, pyrene, dibenzochrysene, or fluorene, which have been known as light emitters in the past, bisstyryl derivatives such as bisstyrylanthracene derivatives and distyrylbenzene derivatives, tetraphenylbutadiene derivatives, cyclopentadiene derivatives, fluorene derivatives, and benzofluorene derivatives. In addition, examples of the host material that can be used include compounds represented by any of the following formulae (H1), (H2), and (H3).

[0211] From the viewpoint of durability, it is also preferable that the hydrogen atoms of the host material are partially or entirely deuterated.Furthermore, it is also preferable to form the light-emitting layer by combining a host compound in which some or all of the hydrogen atoms are deuterated with a dopant compound in which some or all of the hydrogen atoms are deuterated.

[0212] [Compounds represented by any of formulas (H1), (H2) and (H3)] [ka]

[0213] In formulas (H1), (H2) and (H3), L 1 is a single bond or a divalent group containing at least an arylene or heteroarylene. 1 L may be a single bond, or a divalent group formed by linking any two of these with -O-, -S-, -CH2-, -Si(-Arx)2- (Arx is aryl), or cycloalkylene. 1 Among them, the arylene 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. 1 The heteroarylene therein is preferably a heteroarylene having 2 to 24 carbon atoms, more preferably a heteroarylene having 2 to 20 carbon atoms, still more preferably a heteroarylene having 2 to 15 carbon atoms, and particularly preferably a heteroarylene having 2 to 10 carbon atoms. Specific examples thereof include a pyrrole ring, an oxazole ring, an isoxazole ring, a thiazole ring, an isothiazole ring, an imidazole ring, an oxadiazole ring (such as a furazan ring), a thiadiazole ring, a triazole ring, a tetrazole ring, a pyrazole ring, a pyridine ring, a pyrimidine ring, a pyridazine ring, a pyrazine ring, a triazine ring, an indole ring, and an isoindole ring. , 1H-indazole ring, benzimidazole ring, benzoxazole ring, benzothiazole ring, 1H-benzotriazole ring, quinoline ring, isoquinoline ring, cinnoline ring, quinazoline ring, quinoxaline ring, phthalazine ring, naphthyridine ring, purine ring, pteridine ring, carbazole ring, acridine ring, phenoxathiin ring, phenoxazine ring, phenothiazine ring, phenazine ring, indolizine ring, furan ring, benzofuran ring, isobenzofuran ring, dibenzofuran ring, thiophene ring, benzothiophene ring, dibenzothiophene ring, and thianthrene ring. At least one hydrogen atom in the compound represented by each of the above formulae may be substituted with at least one group selected from the substituent group Z or deuterium, for example, alkyl having 1 to 6 carbon atoms, cyano, halogen, or deuterium.

[0214] 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.

[0215] [ka]

[0216] [ka]

[0217] [ka]

[0218] [ka]

[0219] [Anthracene compounds] Examples of the anthracene compound as a host include a compound represented by the formula (3-H) and a compound represented by the formula (3-H2). [ka]

[0220] In formula (3-H), X and Ar 4 are each independently hydrogen, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted diarylamino, optionally substituted diheteroarylamino, substituted or unsubstituted arylheteroarylamino, substituted or unsubstituted alkyl, optionally substituted cycloalkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkoxy, substituted or unsubstituted aryloxy, substituted or unsubstituted arylthio, or substituted silyl; all of X and Ar 4 cannot simultaneously become hydrogen. At least one hydrogen in the compound represented by formula (3-H) may be substituted with halogen, cyano, deuterium or an optionally substituted heteroaryl.

[0221] In addition, a polymer (preferably a dimer) may be formed using the structure represented by formula (3-H) as a unit structure. In this case, for example, the unit structures represented by formula (3-H) may be bonded to each other via X, and examples of X include a single bond, an arylene (phenylene, biphenylene, naphthylene, etc.), and a heteroarylene (a group having a bivalent bond such as a pyridine ring, a dibenzofuran ring, a dibenzothiophene ring, a carbazole ring, a benzocarbazole ring, and a phenyl-substituted carbazole ring).

[0222] Preferred embodiments of the above anthracene compound are described below. The symbols in the following structures are defined as above. [ka]

[0223] In formula (3-H), X is each independently a group represented by formula (3-X1), formula (3-X2) or formula (3-X3), and the group represented by formula (3-X1), formula (3-X2) or formula (3-X3) is bonded to the anthracene ring of formula (3-H) at *. Preferably, two Xs are not simultaneously a group represented by formula (3-X3). More preferably, two Xs are not simultaneously a group represented by formula (3-X2).

[0224] In addition, a polymer (preferably a dimer) may be formed using the structure represented by formula (3-H) as a unit structure. In this case, for example, the unit structures represented by formula (3-H) may be bonded to each other via X, and examples of X include a single bond, an arylene (phenylene, biphenylene, naphthylene, etc.), and a heteroarylene (a group having a bivalent bond such as a pyridine ring, a dibenzofuran ring, a dibenzothiophene ring, a carbazole ring, a benzocarbazole ring, and a phenyl-substituted carbazole ring).

[0225] The naphthylene moieties in formula (3-X1) and formula (3-X2) may be condensed with one benzene ring. The condensed structures are as follows: [ka]

[0226] 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 *.

[0227] 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.

[0228] Also, Ar 3 may have a substituent, and Ar 3 At least one hydrogen atom in may be further substituted with an alkyl group having 1 to 4 carbon atoms, a cycloalkyl group having 5 to 10 carbon atoms, phenyl, biphenylyl, terphenylyl, naphthyl, phenanthryl, fluorenyl, chrysenyl, triphenylenyl, pyrenyl, or a group represented by formula (A) (including carbazolyl and phenyl-substituted carbazolyl). 3 is a group represented by formula (A), the group represented by formula (A) is Ar 3 and combine.

[0229] Ar 4 are each independently hydrogen, phenyl, biphenylyl, terphenylyl, naphthyl, or silyl substituted with alkyl having 1 to 4 carbon atoms (eg, methyl, ethyl, t-butyl) and / or cycloalkyl having 5 to 10 carbon atoms.

[0230] In addition, hydrogen in the chemical structure of the anthracene compound represented by formula (3-H) may be substituted with a group represented by formula (A). When substituted with a group represented by formula (A), the group represented by formula (A) replaces at least one hydrogen in the compound represented by formula (3-H) at the *.

[0231] The group represented by formula (A) is one of the substituents that the anthracene compound represented by formula (3-H) may have. [ka]

[0232] In formula (A), Y is -O-, -S- or >NR 29 and R 21 ~R 28 are each independently hydrogen, optionally substituted alkyl, optionally substituted cycloalkyl, optionally substituted aryl, optionally substituted heteroaryl, optionally substituted alkoxy, optionally substituted aryloxy, optionally substituted arylthio, trialkylsilyl, tricycloalkylsilyl, dialkylcycloalkylsilyl, alkyldicycloalkylsilyl, optionally substituted amino, halogen, hydroxy or cyano; R 21 ~R 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--.

[0233] R 21 ~R 28 In the above, the "substituted amino" of the "optionally substituted amino" includes diarylamino, diheteroarylamino, arylheteroarylamino, and the like.

[0234] Y as 'NR' 29 " R in 29 is hydrogen or optionally substituted aryl.

[0235] R 21 ~R 28 Among these, adjacent groups may be bonded to each other to form a hydrocarbon ring, an aryl ring, or a heteroaryl ring. The group represented by the following formula (A-1) does not form a ring, and the group represented by the following formulas (A-2) to (A-14) may be exemplified as the group formed with a ring. At least one hydrogen atom in the group represented by any of formulas (A-1) to (A-14) may be substituted with alkyl, cycloalkyl, aryl, heteroaryl, alkoxy, aryloxy, arylthio, trialkylsilyl, tricycloalkylsilyl, dialkylcycloalkylsilyl, alkyldicycloalkylsilyl, diaryl (two aryls may be bonded to each other via a linking group), substituted amino, diheteroaryl substituted amino, arylheteroaryl substituted amino, halogen, hydroxy, or cyano.

[0236] [ka]

[0237] Examples of rings formed by bonding adjacent groups to each other include a hydrocarbon ring such as a cyclohexane ring, and examples of aryl and heteroaryl rings include the above-mentioned R 21 ~R 28 Examples of the ring structures include those described in the "aryl" and "heteroaryl" in the formula (A-1), and these rings are formed so as to be condensed with one or two benzene rings in the formula (A-1).

[0238] The group represented by formula (A) is a group obtained by removing one hydrogen atom from any position of formula (A), and * indicates the position. In other words, the group represented by formula (A) may have any position as a bonding position. For example, any carbon atom on the two benzene rings in the structure of formula (A), R 21 ~R 28 An atom on any ring formed by bonding adjacent groups to each other, or ">NR 29 " R in 29 Any position in the 29 " in N(R 29 is a bond). The same applies to the groups represented by any of the formulae (A-1) to (A-14).

[0239] Examples of the group represented by formula (A) include groups represented by any of formulas (A-1) to (A-14). Groups represented by any of formulas (A-1) to (A-5) and (A-12) to (A-14) are preferred. Groups represented by any of formulas (A-1) to (A-4) are more preferred. Groups represented by any of formulas (A-1), (A-3) and (A-4) are even more preferred. Groups represented by formula (A-1) are particularly preferred.

[0240] Examples of the group represented by formula (A) include the following groups: In the formula, Y and * are defined as above. [ka]

[0241] [ka]

[0242] In the compound represented by formula (3-H), the group represented by formula (A) is a naphthalene ring in formula (3-X1) or formula (3-X2), a single bond in formula (3-X3), and Ar in formula (3-X3). 3 Preferably, the compound is combined with any one of the following:

[0243] All or a part of the hydrogen atoms in the chemical structure of the anthracene compound represented by formula (3-H) may be deuterium atoms.

[0244] The anthracene compound as the host may be, for example, a compound represented by the following formula (3-H2). [ka]

[0245] In formula (3-H2), Ar c is optionally substituted aryl or optionally substituted heteroaryl, R c is hydrogen, alkyl, or cycloalkyl; Ar 11 , Ar 12 , Ar 13 , Ar 14 , Ar 15 , Ar 16 , Ar 17 , and Ar 18 are each independently hydrogen, 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 (aryl and 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) is optionally substituted with halogen, cyano, or deuterium.

[0246] The "optionally substituted aryl" is also preferably a group represented by any one of the following formulae (3-H2-X1) to (3-H2-X8).

[0247] [ka]

[0248] In formulae (3-H2-X1) to (3-H2-X8), * indicates a bond position. In formulae (3-H2-X1) to (3-H2-X3), Ar 21 , Ar 22 , and Ar 23 are each independently hydrogen, phenyl, biphenylyl, terphenylyl, quaterphenylyl, naphthyl, phenanthryl, fluorenyl, benzofluorenyl, chrysenyl, triphenylenyl, pyrenyl, anthracenyl, or a group represented by formula (A). In the explanation of formula (3-H2), the group represented by formula (A) is the same as that explained in the anthracene compound represented by formula (3-H).

[0249] In the formulae (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 an alkyl group having 1 to 6 carbon atoms (preferably methyl or t-butyl).

[0250] Furthermore, preferred examples of the "optionally substituted aryl" include terphenylyl (particularly m-terphenyl-5'-yl) which may be substituted with one or more substituents selected from the group consisting of phenyl, biphenylyl, terphenylyl, naphthyl, phenanthryl, fluorenyl, chrysenyl, triphenylenyl, pyrenyl, and a group represented by formula (A).

[0251] The "optionally substituted heteroaryl" also includes a group represented by formula (A). In addition, specific examples of the "optionally substituted aryl" and the "optionally substituted heteroaryl" include dibenzofuryl, naphthobenzofuryl, and phenyl-substituted dibenzofuryl.

[0252] At least one hydrogen atom in the compound represented by formula (3-H2) may be replaced by a halogen atom, a cyano atom, or a deuterium atom. In this case, "halogen" includes fluorine, chlorine, bromine, and iodine. In particular, the compound represented by formula (3-H2) in which all hydrogen atoms are replaced by deuterium atoms is preferred.

[0253] 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 are optionally substituted aryl or optionally substituted heteroaryl. That is, it is preferable that the anthracene compound represented by formula (3-H2) has a structure in which at least three substituents selected from the group consisting of optionally substituted aryl and optionally substituted heteroaryl are bonded to the anthracene ring.

[0254] The anthracene compound represented by formula (3-H2) is Ar 11 ~Ar 18 It is more preferable that two of the substituents are optionally substituted aryl or optionally substituted heteroaryl, and the other six are hydrogen, optionally substituted alkyl, optionally substituted cycloalkyl, optionally substituted alkenyl, or optionally substituted alkoxy. That is, it is more preferable that the anthracene compound represented by formula (3-H2) has a structure in which three substituents selected from the group consisting of optionally substituted aryl and optionally substituted heteroaryl are bonded to the anthracene ring.

[0255] 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.

[0256] Furthermore, in formula (3-H2), R c is hydrogen and Ar 11 ~Ar 18 It is preferred that any six of these are hydrogen.

[0257] 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]

[0258] In the formula (3-H2-A), (3-H2-B), (3-H2-C), (3-H2-D) or (3-H2-E), Ar c ', Ar 11 ', Ar 12 ', Ar 13 ', Ar 14 ', Ar 15 ', Ar 17 ', and Ar 18 ' are each independently phenyl, biphenylyl, terphenylyl, quaterphenylyl, naphthyl, phenanthryl, fluorenyl, benzofluorenyl, chrysenyl, triphenylenyl, pyrenyl, or a group represented by formula (A), and at least one hydrogen atom in these groups may be substituted with phenyl, biphenylyl, terphenylyl, quaterphenylyl, naphthyl, phenanthryl, fluorenyl, benzofluorenyl, chrysenyl, triphenylenyl, pyrenyl, or a group represented by formula (A). Here, when both hydrogen atoms of the methylene in fluorenyl and benzofluorenyl are substituted with phenyl, these phenyls may be bonded to each other by a single bond. Ar c ', Ar 11 ', Ar 12 ', Ar 13 ', Ar 14 ', Ar 15 ', Ar 17 ', and Ar 18 Carbon atoms of the anthracene ring that are not bonded with ' may have methyl or t-butyl bonded instead of hydrogen.

[0259] Ar c ', Ar 11 ', Ar 12 ', Ar 13 ', Ar 14 ', Ar 15 ', Ar 17 ', and Ar 18 When each of "1" and "2" is a substituted or unsubstituted phenyl or a substituted or unsubstituted naphthyl, it is preferably a group represented by any one of the above formulae (3-H2-X1) to (3-H2-X8).

[0260] Ar c ', Ar 11 ', Ar 12 ', Ar 13 ', Ar 14 ', Ar 15 ', Ar 17 ', and Ar 18 More preferably, each ' is independently phenyl, biphenylyl (particularly biphenyl-2-yl or biphenyl-4-yl), terphenylyl (particularly m-terphenyl-5'-yl), naphthyl, phenanthryl, fluorenyl, or a group represented by any one of the above formulas (A-1) to (A-4), and in this case, at least one hydrogen atom in these groups may be substituted by phenyl, biphenylyl, naphthyl, phenanthryl, fluorenyl, or a group represented by any one of the above formulas (A-1) to (A-4).

[0261] In addition, at least one hydrogen atom in the compound represented by formula (3-H2-A), (3-H2-B), (3-H2-C), (3-H2-D), or (3-H2-E) may be replaced with a halogen atom, a cyano atom, or a deuterium atom. A deuterated form is preferable, and a form in which all anthracene rings are deuterated or a form in which all hydrogen atoms are deuterated is preferable.

[0262] Particularly preferred anthracene compounds represented by formula (3-H2) include those represented by formula (3-H2-Aa) below. [ka]

[0263] In formula (3-H2-Aa), Ar c ', Ar 14 ', and Ar 15 Each of the ' is independently phenyl, biphenylyl, terphenylyl, naphthyl, phenanthryl, fluorenyl, benzofluorenyl, chrysenyl, triphenylenyl, pyrenyl, or a group represented by any one of the above formulas (A-1) to (A-11), and at least one hydrogen atom in these groups may be substituted with phenyl, biphenylyl, terphenylyl, naphthyl, phenanthryl, fluorenyl, benzofluorenyl, chrysenyl, triphenylenyl, pyrenyl, or a group represented by any one of the formulas (A-1) to (A-11). Here, when both hydrogen atoms of the methylene in the fluorenyl and benzofluorenyl are substituted with phenyl, these phenyls may be bonded to each other by a single bond. In addition, Ar c ', Ar 14 ', and Ar 15 A carbon atom on the anthracene ring to which ' is not bonded may be substituted with methyl or t-butyl instead of hydrogen. At least one hydrogen in the compound represented by formula (3-H2-Aa) may be substituted with halogen or cyano, and at least one hydrogen in the compound represented by formula (3-H2-Aa) is substituted with deuterium.

[0264] In formula (3-H2-Aa), Ar c ', Ar 14 ', and Ar 15 Each ' is preferably independently phenyl, biphenylyl, terphenylyl, naphthyl, phenanthryl, fluorenyl, or a group represented by any one of the above formulas (A-1) to (A-4), and at least one hydrogen in these groups may be substituted by phenyl, naphthyl, phenanthryl, fluorenyl, or a group represented by any one of the above formulas (A-1) to (A-4).

[0265] In the compound represented by formula (3-H2-Aa), at least the carbon at the 10-position of the anthracene ring (Ar c It is preferable that the hydrogen bonded to the carbon atom to which Ar′ is bonded (the carbon atom to which Ar′ is bonded is the 9th position) is replaced with deuterium. That is, the compound represented by formula (3-H2-Aa) is preferably a compound represented by the following formula (3-H2-Ab). In formula (3-H2-Ab), D is deuterium, and c ', Ar 14 ', and Ar 15 ' is the same as defined in formula (3-H2-Aa). D in formula (3-H2-Ab) indicates that at least this position is deuterium, and any one or more other hydrogens in formula (3-H2-Ab) may be deuterium at the same time, and it is also preferable that all hydrogens in formula (3-H2-Ab) are deuterium.

[0266] [ka]

[0267] Specific examples of anthracene compounds include compounds represented by formulae (3-131-Y) to (3-182-Y), (3-183-N), (3-184-Y) to (3-284-Y), (3-500) to (3-557), (3-600) to (3-605), and (3-606-Y) to (3-626-Y). Hydrogen atoms in these formulae may be partially or completely replaced with deuterium, and particularly preferred forms of deuterium replacement are listed individually. Y in the formulae is -O-, -S-, >NR 29 (R 29 is defined as above) or >C(-R 30 )2(R 30 R may be either an optionally linked aryl or an alkyl; 29 For example, phenyl, R 30 For example, is methyl. For formula numbers, for example, when Y is O, formula (3-131-Y) is formula (3-131-O), and Y is -S- or >NR 29 In the case of (3-131-S) or (3-131-N), respectively, use formula (3-131-S) or formula (3-131-N).

[0268]

change

[0269]

change

[0270]

change

[0271]

change

[0272]

change

[0273]

change

[0274]

change

[0275]

change

[0276]

change

[0277]

change

[0278]

change

[0279] [ka]

[0280] [ka]

[0281] [ka]

[0282] [ka]

[0283] [ka]

[0284] [ka]

[0285] [ka]

[0286] [ka]

[0287] [ka] In the above formula, D is deuterium.

[0288] Among these compounds, the compounds of formula (3-131-Y) to formula (3-134-Y), formula (3-138-Y), formula (3-140-Y) to formula (3-143-Y), formula (3-150-Y), formula (3-153-Y) to formula (3-156-Y), formula (3-166-Y), formula (3-168-Y), formula (3-173-Y), formula (3-177-Y), formula (3-180-Y) to formula (3-183-N), formula (3-185-Y), formula (3-190-Y), formula (3-223-Y), formula (3-241- Y), the formula (3-250-Y), the formula (3-252-Y) to the formula (3-254-Y), the formula (3-270-Y) to the formula (3-284-Y), the formula (3-501), the formula (3-507), the formula (3-508), the formula (3-509), the formula (3-513), the formula (3-514), the formula (3-519), the formula (3-521), the formula (3-538) to the formula (3-547), or the formula (3-600) to the formula (3-605), and the formula (3-606-Y) to the formula (3-626-Y) are preferable. In addition, Y is -O- or >NR 29 is preferred, and -O- is more preferred. Deuterium-substituted forms are also preferred.

[0289] The above anthracene compound is a compound having a reactive group at a desired position of the anthracene skeleton, and an anthracene compound represented by formula (3-H) is a compound having X, Ar 4 The compound having a reactive group in a partial structure such as the structure of formula (A) can be used as a starting material to produce the compound by applying Suzuki coupling, Negishi coupling, or other known coupling reactions. Examples of reactive groups in these reactive compounds include halogens and boronic acids. As a specific production method, for example, the synthesis methods in paragraphs

[0089] to

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

[0290] [Fluorene compounds] The compound represented by formula (4-H) basically functions as a host. [ka]

[0291] 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 (aryl and heteroaryl 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, 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 (two aryls may be bonded to each other via a linking group), a diheteroarylamino (two heteroaryls may be bonded to each other via a linking group), an arylheteroarylamino (an aryl and a heteroaryl may be bonded to each other via a linking group), an alkyl, a cycloalkyl, an alkenyl, an alkoxy, or an aryloxy, 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 (4-H) may be substituted with a halogen, a cyano, or a deuterium.

[0292] 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).

[0293] [ka]

[0294] 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.

[0295] These heteroaryls may be bonded to the fluorene skeleton in formula (4-H) via a single bond or a linking group. That is, the fluorene skeleton in formula (4-H) and the above heteroaryls may be bonded directly, or may be bonded to each other via a linking group. Examples of the linking group include phenylene, biphenylene, naphthylene, anthracenylene, methylene, ethylene, -OCH2CH2-, -CH2CH2O-, or -OCH2CH2O-.

[0296] In addition, R in formula (4-H) 1 and R 2 , R 2 and R 3 , R 3 and R 4 , R 5 and R 6 , R 6 and R 7 or R 7 and R 8 are each independently bonded to form a fused ring, R 9 and R 10 may be bonded to form a spiro ring. 1 From R 8 The fused ring formed by is a ring fused to the benzene ring in formula (4-H), and is an aliphatic ring or an aromatic ring. An aromatic ring is preferable, and examples of the structure including the benzene ring in formula (4-H) include a naphthalene ring and a phenanthrene ring. 9 and R 10 The spiro ring formed by the formula (4-H) is a ring that is spiro-bonded to the five-membered ring in formula (4-H), and is an aliphatic ring or an aromatic ring. An aromatic ring, such as a fluorene ring, is preferred.

[0297] The compound represented by formula (4-H) is preferably a compound represented by the following formula (4-H-1), formula (4-H-2) or formula (4-H-3), 1 and R 2 In the formula (4-H), R 3 and R 4 In the formula (4-H), R 1 From R 8 is a compound in which none of the above is bound.

[0298] [ka]

[0299] 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 is the same as R in formula (4-H-1) and formula (4-H-2). 11 From R 14 The definition of R in formula (4-H) 1 From R 10 is the same as:

[0300] The compound represented by formula (4-H) is more preferably a compound represented by the following formula (4-H-1A), formula (4-H-2A) or formula (4-H-3A), in which R 9 and R 10 is a compound in which a spiro-fluorene ring is formed by bonding.

[0301] [ka]

[0302] R in formula (4-H-1A), formula (4-H-2A) and formula (4-H-3A) 2 From R 7 The definition of is the corresponding R in formula (4-H-1), formula (4-H-2) and formula (4-H-3). 2 From R 7 is the same as R in formula (4-H-1A) and formula (4-H-2A). 11 From R 14 The definition of R in formula (4-H-1) and formula (4-H-2) is also 11 From R 14 is the same as:

[0303] In addition, all or a part of the hydrogen atoms in the compound represented by formula (4-H) may be substituted with halogen, cyano or deuterium.

[0304] More specific examples of the fluorene compound as the host of the present invention include compounds represented by the following structural formulas. [ka]

[0305] [Pyrene compounds] Examples of pyrene compounds include the pyrene compounds described in WO 2021 / 210304, WO 2021 / 210305, or WO 2021 / 049659.

[0306] Specific examples of the pyrene compound include the following compounds. [ka]

[0307] [Dibenzochrysene compounds] The dibenzochrysene compound as the host is, for example, a compound represented by the following formula (5-H). [ka]

[0308] In formula (5-H), R 1 From R 16 are each independently hydrogen, aryl, heteroaryl (the heteroaryl may be bonded to the dibenzochrysene skeleton in formula (5-H) via a single bond or a linking group), diarylamino, diheteroarylamino, arylheteroarylamino, alkyl, cycloalkyl, alkenyl, alkoxy, or aryloxy, in which at least one hydrogen may be replaced by an aryl, heteroaryl, alkyl, or cycloalkyl; and R 1 From R 16 Adjacent groups among these may be bonded to each other to form a fused ring, and at least one hydrogen atom in the formed ring may be substituted with an aryl, a heteroaryl (the heteroaryl may be bonded to the formed ring via a single bond or a linking group), a diarylamino, a diheteroarylamino, an arylheteroarylamino, an alkyl, a cycloalkyl, an alkenyl, an alkoxy, or an aryloxy, and at least one hydrogen atom in these may be substituted with an aryl, a heteroaryl, an alkyl, or a cycloalkyl, and at least one hydrogen atom in the compound represented by formula (5-H) may be substituted with a halogen, a cyano, or a deuterium.

[0309] The alkenyl in the definition of formula (5-H) is, for example, an alkenyl having 2 to 30 carbon atoms, preferably an alkenyl having 2 to 20 carbon atoms, more preferably an alkenyl having 2 to 10 carbon atoms, further preferably an alkenyl having 2 to 6 carbon atoms, and particularly preferably an alkenyl having 2 to 4 carbon atoms. Preferred alkenyls are vinyl, 1-propenyl, 2-propenyl, 1-butenyl, 2-butenyl, 3-butenyl, 1-pentenyl, 2-pentenyl, 3-pentenyl, 4-pentenyl, 1-hexenyl, 2-hexenyl, 3-hexenyl, 4-hexenyl, or 5-hexenyl.

[0310] 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).

[0311] [ka]

[0312] 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.

[0313] These heteroaryls may be bonded to the dibenzochrysene skeleton in formula (5-H) via a single bond or a linking group. That is, the dibenzochrysene skeleton and the heteroaryl in formula (5-H) may be bonded directly or via a linking group. Examples of the linking group include phenylene, biphenylene, naphthylene, anthracenylene, methylene, ethylene, -OCH2CH2-, -CH2CH2O-, or -OCH2CH2O-.

[0314] The compound represented by formula (5-H) is preferably R 1 , R 4 , R 5 , R 8 , R 9 , R 12 , R 13 and R 16 is hydrogen. In this case, R in formula (5-H) 2 , R 3 , R 6 , R 7 , R 10 , R 11 , R 14 and R 15 are preferably each independently hydrogen, phenyl, biphenylyl, naphthyl, anthracenyl, phenanthryl, a monovalent group having a structure of formula (5-Ar1), formula (5-Ar2), formula (5-Ar3), formula (5-Ar4) or formula (5-Ar5) (the monovalent group having the structure may be bonded to the dibenzochrysene skeleton in formula (5-H) via phenylene, biphenylene, naphthylene, anthracenylene, methylene, ethylene, -OCHCH-, -CHCHO- or -OCHCHO-), methyl, ethyl, propyl or butyl.

[0315] The compound represented by formula (5-H) is more preferably 1 , R 2 , R 4 , R 5 , R 7 , R 8 , R 9 , R 10 , R 12 , R 13 , R 15 and R 16 is hydrogen. In this case, R in formula (5-H) 3 , R 6 , R 11 and R 14 At least one (preferably one or two, more preferably one) of the above is a single bond, phenylene, biphenylene, naphthylene, anthracenylene, methylene, ethylene, -OCH2CH2-, -CH2CHO-, or a monovalent group having a structure of formula (5-Ar1), (5-Ar2), (5-Ar3), (5-Ar4) or (5-Ar5) via -OCH2CHO-, and the other (i.e., other than the position where the monovalent group having the above structure is substituted) is hydrogen, phenyl, biphenylyl, naphthyl, anthracenyl, methyl, ethyl, propyl, or butyl, and at least one hydrogen in these may be substituted with phenyl, biphenylyl, naphthyl, anthracenyl, methyl, ethyl, propyl, or butyl.

[0316] In addition, R in formula (5-H) 2 , R 3 , R 6 , R 7 , R 10 , R 11 , R 14 and R 15 When a monovalent group having a structure represented by formula (5-Ar1) to formula (5-Ar5) is selected as the aryl group, at least one hydrogen atom in the structure is selected from the group represented by formula (5-Ar1) to formula (5-Ar5). 1 From R 16 may be bonded to any one of the following to form a single bond.

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

[0318] [ka]

[0319] The above-mentioned light-emitting layer materials (host material and dopant material) can be used as light-emitting layer materials as polymer compounds obtained by polymerizing a reactive compound substituted with a reactive substituent as a monomer, or as crosslinked polymers thereof, or as pendant polymer compounds obtained by reacting a main chain polymer with the reactive compound, or as crosslinked pendant polymers thereof. In this case, the explanation of the polycyclic aromatic compound represented by formula (1) can be cited as the reactive substituent.

[0320] <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 an emitting dopant. A thermally activated delayed phosphor can be used as the assisting dopant (compound).

[0321] 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 means a compound whose lowest excited singlet energy level, determined from the shoulder on the short wavelength side of the peak of the fluorescence spectrum, is higher than that of the thermally activated delayed fluorescent substance as the second component and the emitting dopant as the third component.

[0322] The term "thermally activated delayed fluorescent substance" refers to a compound that absorbs thermal energy, undergoes reverse intersystem crossing from the lowest excited triplet state to the lowest excited singlet state, and is radiatively deactivated 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 triplet state during the excitation process from the lowest excited triplet state to the lowest excited singlet state. For example, there are 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. 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 an emitting molecule, Graduate School of Engineering, Kyoto University). In the present invention, when a sample containing a target compound is measured for its fluorescence lifetime at 300K, if a slow fluorescent component is observed, the target compound is determined to be a "thermally activated delayed fluorescent substance." Here, a slow fluorescent component refers to a component whose fluorescence lifetime is 0.1 μsec or longer. The fluorescence lifetime can be measured, for example, using a fluorescence lifetime measuring device (manufactured by Hamamatsu Photonics, C11367-01).

[0323] The polycyclic aromatic compound of the present invention can function as an emitting dopant, and the "thermally activated delayed phosphor" can function as an assisting dopant that assists the emission of the polycyclic aromatic compound of the present invention.

[0324] In this embodiment, the host compound may be a known one, for example, a compound having at least one of a carbazole ring and a furan ring, and among them, it is preferable to use a compound having at least one of furanyl and carbazolyl and at least one of arylene and heteroarylene bonded thereto.Specific examples include compounds represented by any of formulas (H1), (H2) and (H3), particularly mCP and mCBP.

[0325] The lowest excited triplet energy level E(1,T,Sh) obtained from the shoulder on the short wavelength side of the peak of the phosphorescence spectrum of the host compound is preferably higher than the lowest excited triplet energy levels E(2,T,Sh) and E(3,T,Sh) of the emitting dopant or assisting dopant having the highest lowest excited triplet energy level in the emitting layer, from the viewpoint of promoting TADF generation in the emitting layer without inhibiting it. Specifically, the lowest excited triplet energy level E(1,T,Sh) of the host compound is preferably 0.01 eV or more, more preferably 0.03 eV or more, and even more preferably 0.1 eV or more, compared to E(2,T,Sh) and E(3,T,Sh). In addition, a TADF-active compound may be used as the host compound.

[0326] As the host compound, for example, a compound represented by any one of the above formulas (H1), (H2) and (H3) can be used.

[0327] <Thermal 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, so that efficient reverse intersystem crossing occurs. Here, in this specification, 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.

[0328] In general, a thermally activated delayed phosphor using a donor or an acceptor has a large spin orbit coupling (SOC) due to its structure, and a small exchange interaction between HOMO and LUMO, resulting in a small ΔE(ST), so that a very fast reverse intersystem crossing rate can be obtained. 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 that satisfies any one or all of high efficiency, high color purity, and long life can be provided. 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 included in the same layer, or may be included in adjacent layers or other adjacent layers.

[0329] As the thermally activated delayed phosphor in the TAF element, for example, a compound in which a donor and an acceptor are bonded directly or via a spacer can be used. As the electron donor group (donor structure) and electron acceptor group (acceptor structure) used in the thermally activated delayed phosphor of the present invention, for example, the structure described in Chemistry of Materials, 2017, 29, 1946-1963 can be used. Donor structures include carbazole, dimethylcarbazole, di-tert-butylcarbazole, dimethoxycarbazole, tetramethylcarbazole, benzofluorocarbazole, benzothienocarbazole, phenyldihydroindolocarbazole, phenylbicarbazole, bicarbazole, tercarbazole, diphenylcarbazolylamine, tetraphenylcarbazolyldiamine, phenoxazine, dihydrophenazine, phenothiazine, dimethyldihydroacridine, diphenylamine, bis(tert-butylphenyl)amine, N1-(4-(diphenylamino)phenyl)-N4,N4-diphenylbenzene-1,4-diamine, dimethyltetraphenyldihydroacridinediamine, tetramethyl-dihydro-indenoacridine, and diphenyl-dihydrodibenzoazasiline.Acceptor structures include sulfonyldibenzene, benzophenone, phenylenebis(phenylmethanone), benzonitrile, isonicotinonitrile, phthalonitrile, isophthalonitrile, paraphthalonitrile, benzenetricarbonitrile, triazole, oxazole, thiadiazole, benzothiazole, benzobis(thiazole), benzoxazole, benzobis(oxazole), quinoline, benzimidazole, dibenzoquinoxaline, heptaazaphenalene, thioxanthone dioxide, dimethylanthracenone, anthracenedione, 5H-cyclopenta[1,2-b:5,4-b']dipyridine, fluorene dicarbonitrile, triphenyltriazine, pyrazinedicarbonitrile, pyrimidine, phenylpyrimidine, methylpyrimidine, pyridinedicarbonitrile, dibenzoquinoxalinedicarbonitrile, bis(phenylsulfonyl)benzene, dimethylthioxanthene dioxide, thianthrene tetraoxide, and tris(dimethylphenyl)borane. In particular, the compound having thermally activated delayed fluorescence in the TAF element is preferably a compound having at least one partial structure selected from carbazole, phenoxazine, acridine, triazine, pyrimidine, pyrazine, thioxanthene, benzonitrile, phthalonitrile, isophthalonitrile, diphenylsulfone, triazole, oxadiazole, thiadiazole, and benzophenone.

[0330] 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 of the compound is at least partially overlapped with the absorption peak of the emitting dopant. In the following, the compound that can be used as the second component (thermally activated delayed phosphor) of the light-emitting layer in the TAF element is exemplified. However, the compound that can be used as the thermally activated delayed phosphor in the TAF element is not limited to the following exemplified compounds.

[0331] [ka]

[0332] [ka]

[0333] [ka]

[0334] [ka]

[0335] [ka]

[0336] Furthermore, as the thermally activated delayed phosphor, a compound represented by any one of the following formulae (AD1), (AD2) and (AD3) can also be used. [ka]

[0337] In the above formulas (AD1), (AD2) and (AD3), M is each independently a single bond, -O-, >N-Ar or >CAr2, and is preferably a single bond, -O- or >N-Ar from the viewpoint of the depth of the HOMO of the partial structure to be formed and the height of the lowest excited singlet energy level and the lowest excited triplet energy level. J is a spacer structure separating the donor partial structure and the acceptor partial structure, and is each independently an arylene having 6 to 18 carbon atoms, and is preferably an arylene having 6 to 12 carbon atoms from the viewpoint of the magnitude of the conjugation exuded from the donor partial structure and the acceptor partial structure. More specifically, phenylene, methylphenylene and dimethylphenylene are exemplified. Q is each independently =C(-H)- or =N-, and is preferably =N- from the viewpoint of the shallowness of the LUMO of the partial structure to be formed and the height of the lowest excited singlet energy level and the lowest excited triplet energy level. Ar are each 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, and 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, 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 further 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, preferably an integer of 4 to (6-m). Furthermore, at least one hydrogen in the compounds represented by the above formulas may be substituted with a halogen or deuterium.

[0338] 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.

[0339] The compound used as the second component in this embodiment may be a donor-acceptor type 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 directly or via a linking group to one acceptor A is preferred because it provides an organic electroluminescent device with better properties. (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 Each independently represents a donor group. As the donor group, the above-mentioned donor structure can be used. A 1 and A 2 Each of L independently represents an acceptor group. As the acceptor group, the above-mentioned acceptor structure can be used. 1 , L 2 and L 3 Each of L independently represents a single bond or a conjugated linking group. The conjugated linking group is a spacer structure that separates a donor group and an acceptor group, and is preferably an arylene having 6 to 18 carbon atoms, and more preferably an arylene having 6 to 12 carbon atoms. 1 , L 2 and L 3 More preferably, each independently represents phenylene, methylphenylene, or dimethylphenylene. 1 represents an integer equal to or less than the maximum number that can be substituted. 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 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.

[0340] [ka]

[0341] In this embodiment, the light-emitting layer may be 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 each of the 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 one type or a combination of multiple types. The assisting dopant and the emitting dopant may be entirely or partially contained 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 a ternary co-evaporation method of the host compound, the assisting dopant, and the emitting dopant, a method of mixing the host compound, the assisting dopant, and the emitting dopant in advance and then simultaneously evaporating them, or a wet film-forming method of applying a composition (paint) for forming a light-emitting layer prepared by dissolving the host compound, the assisting dopant, and the emitting dopant in an organic solvent, or the like.

[0342] The amount of the host compound used varies depending on the type of the 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 material for the light-emitting layer. The above range is preferable in terms of, for example, efficient charge transport and efficient energy transfer to the dopant.

[0343] 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 characteristics of the assisting dopant. The amount of the assisting dopant used is preferably 1 to 60% by mass, more preferably 2 to 50% by mass, and even more preferably 5 to 30% by mass of the total mass of the material for the light-emitting layer. If it is within the above range, it is preferable in that, for example, energy can be efficiently transferred to the emitting dopant.

[0344] The amount of the emitting dopant (a compound having a boron atom) used varies depending on the type of the emitting dopant, and may be determined according to the characteristics of the emitting dopant. The amount of the 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, based on the total mass of the material for the light-emitting layer. The above range is preferable in that, for example, concentration quenching can be prevented.

[0345] The amount of the emitting dopant used is preferably low in terms of preventing concentration quenching. The amount of the assisting dopant used is preferably high in terms of efficiency of thermally activated delayed fluorescence mechanism. Furthermore, from the viewpoint of efficiency of the thermally activated delayed fluorescence mechanism of the assisting dopant, the amount of the emitting dopant used is preferably low in comparison with the amount of the assisting dopant used.

[0346] <2-1-3. Substrate for organic electroluminescent device> The substrate 101 is a support for the organic EL element 100, and is usually made of quartz, glass, metal, plastic, or the like. The substrate 101 is formed into a plate, film, or sheet shape depending on the purpose, and for example, a glass plate, a metal plate, a metal foil, a plastic film, a plastic sheet, or the like is used. Among them, a glass plate and a plate made of a transparent synthetic resin such as polyester, polymethacrylate, polycarbonate, or polysulfone are preferable. For a glass substrate, soda-lime glass or alkali-free glass is used, and the thickness is sufficient to maintain mechanical strength, so that it may be, for example, 0.2 mm or more. The upper limit of the thickness is, for example, 2 mm or less, preferably 1 mm or less. As for the material of the glass, it is preferable that the amount of ions eluted from the glass is small, so alkali-free glass is preferable, but soda-lime glass with a barrier coat such as SiO2 is also commercially available, and this can 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. It is particularly preferable to provide a gas barrier film when a synthetic resin plate, film or sheet having poor gas barrier properties is used as the substrate 101.

[0347] <2-1-4. Anode in organic electroluminescent device> The anode 102 serves to inject holes into the light-emitting layer 105. When either one of the hole injection layer 103 and the hole transport layer 104 is provided between the anode 102 and the light-emitting layer 105, holes are injected into the light-emitting layer 105 via the hole injection layer 103 or the hole transport layer 104.

[0348] Materials for forming the anode 102 include inorganic compounds and organic compounds. Examples of inorganic compounds include metals (aluminum, gold, silver, nickel, palladium, chromium, etc.), metal oxides (indium oxide, tin oxide, indium-tin oxide (ITO), indium-zinc oxide (IZO), etc.), metal halides (copper iodide, etc.), copper sulfide, carbon black, ITO glass, and Nesa glass. Examples of organic compounds include polythiophenes such as poly(3-methylthiophene), polypyrrole, polyaniline, and other conductive polymers. In addition, materials that are used as anodes in organic EL elements can be appropriately selected and used.

[0349] The resistance of the transparent electrode is not limited as long as it can supply a sufficient current for the light emission of the light emitting element, but it is desirable that the resistance is low from the viewpoint of the power consumption of the light emitting element. For example, an ITO substrate of 300Ω / □ or less functions as an element electrode, but since it is now possible to supply substrates of about 10Ω / □, it is particularly desirable to use a low resistance product of, for example, 100 to 5Ω / □, preferably 50 to 5Ω / □. The thickness of the ITO can be selected arbitrarily according to the resistance value, but it is usually used in the range of 50 to 300 nm.

[0350] <2-1-5. Hole injection layer and hole transport layer in organic electroluminescence device> The hole injection layer 103 plays a role of efficiently injecting holes moving from the anode 102 into the light emitting layer 105 or the hole transport layer 104. The hole transport layer 104 plays a role of efficiently transporting holes injected from the anode 102 or holes injected from the anode 102 via the hole injection layer 103 to the light emitting layer 105. The hole injection layer 103 and the hole transport layer 104 are each formed by laminating and 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.

[0351] A hole injection / transport material is required to efficiently inject / transport holes from the positive electrode between electrodes to which an electric field is applied, and it is desirable for the material to have high hole injection efficiency and efficiently transport the injected holes. For this purpose, it is preferable for the material to have a small ionization potential, a large hole mobility, excellent stability, and a low probability of generating impurities that act as traps during manufacture and use.

[0352] As the material for forming the hole injection layer 103 and the hole transport layer 104, any compound can be selected from compounds conventionally used as charge transport materials for holes in photoconductive materials, p-type semiconductors, and known compounds used in hole injection layers and hole transport layers of organic EL elements. Specific examples of such compounds include carbazole derivatives (N-phenylcarbazole, polyvinylcarbazole, etc.), biscarbazole derivatives such as bis(N-arylcarbazole) or bis(N-alkylcarbazole), triarylamine derivatives (4,4',4"-tris(N-carbazolyl)triphenylamine, polymers having aromatic tertiary amino in the main chain or side chain, 1,1-bis(4-di-p-tolylaminophenyl)cyclohexane, N,N'-diphenyl-N,N'-di(3-methylphenyl)-4,4'-diaminobiphenyl, N,N'-diphenyl-N,N'-dinaphthyl-4,4'-diaminobiphenyl, N,N'-diphenyl-N,N'-di(3-methylphenyl)-4,4'-diphenyl-1,1'-diamine, N,N'-dinaphthyl-N,N'-diphenyl-4,4'-diphenyl-1,1'-diamine, N 4 ,N 4 '-Diphenyl-N 4 ,N 4 '-Bis(9-phenyl-9H-carbazol-3-yl)-[1,1'-biphenyl]-4,4'-diamine, N 4 ,N 4 ,N 4 ',N 4 '-Tetra[1,1'-biphenyl]-4-yl)-[1,1'-biphenyl]-4,4'-diamine, 4,4',4"-triphenylamine derivatives such as 3-methylphenyl(phenyl)amino)triphenylamine, starburst amine derivatives, etc., stilbene derivatives, phthalocyanine derivatives (metal-free, copper phthalocyanine, etc.), pyrazoline derivatives, hydrazone compounds, benzofuran derivatives, thiophene derivatives, oxadiazole derivatives, quinoxaline derivatives, etc. Conductors (e.g., 1,4,5,8,9,12-hexaazatriphenylene-2,3,6,7,10,11-hexacarbonitrile, etc.), heterocyclic compounds such as porphyrin derivatives, polysilanes, etc. As polymers, polycarbonates and styrene derivatives having the above-mentioned monomers in their side chains, polyvinylcarbazole, polysilanes, etc. are preferred, but there are no particular limitations on the compounds as long as they can form a thin film required for fabricating a light-emitting device, can inject holes from the anode, and can transport holes.

[0353] It is also known that the electrical conductivity of organic semiconductors is strongly influenced by their doping. Such organic semiconductor matrix substances consist of compounds with good electron donating or accepting properties. For doping with electron donating substances, strong electron acceptors such as tetracyanoquinone dimethane (TCNQ) or 2,3,5,6-tetrafluorotetracyano-1,4-benzoquinone dimethane (F4TCNQ) are known (see, for example, the references "M. Pfeiffer, A. Beyer, T. Fritz, K. Leo, Appl. Phys. Lett., 73(22), 3202-3204 (1998)" and "J. Blochwitz, M. Pfeiffer, T. Fritz, K. Leo, Appl. Phys. Lett., 73(6), 729-731 (1998)"). These generate so-called holes by an electron transfer process in the electron donating base substance (hole transport substance). The conductivity of the base material varies considerably depending on the number and mobility of holes. As a matrix material having hole transport properties, for example, benzidine derivatives (TPD, etc.), starburst amine derivatives (TDATA, etc.), or specific metal phthalocyanines (especially zinc phthalocyanine (ZnPc) etc.) are known (JP-A-2005-167175). The polycyclic aromatic compound of the present invention may be used as a material for forming a hole injection layer or a material for forming a hole transport layer.

[0354] <2-1-6. Electron blocking layer in organic electroluminescent device> An electron blocking layer for preventing diffusion of electrons from the light emitting layer may be provided between the hole injection / transport layer and 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.

[0355] <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 types of electron transport / injection materials, or by a mixture of an electron transport / injection material and a polymer binder.

[0356] The electron injection / transport layer is a layer that is responsible for injecting electrons from the cathode and transporting the electrons. It is desirable that the electron injection efficiency is high and that the injected electrons are efficiently transported. For this purpose, it is preferable that the material has a large electron affinity, a large electron mobility, and excellent stability, and impurities that become traps are unlikely to occur during manufacture and use. However, when considering the balance of transport of holes and electrons, if the material mainly plays a role of efficiently preventing holes from flowing from the anode to the cathode without recombining, even if the electron transport ability is not so high, it has the effect of improving the luminous efficiency equivalent to a material with a high electron transport ability. Therefore, the electron injection / transport layer in this embodiment may also include the function of a layer that can efficiently block the movement of holes.

[0357] The material (electron transport material) for forming the electron transport layer 106 or the electron injection layer 107 can be arbitrarily selected from compounds conventionally used as electron transport compounds in photoconductive materials and known compounds used in the electron injection layer and electron transport layer of organic EL elements.

[0358] Materials used in the electron transport layer or electron injection layer preferably contain at least one selected from compounds consisting of aromatic rings or heteroaromatic rings composed of one or more atoms selected from carbon, hydrogen, oxygen, sulfur, silicon, and phosphorus, pyrrole derivatives and their condensed ring derivatives, and metal complexes having electron-accepting nitrogen. Specific examples include condensed ring aromatic ring derivatives such as naphthalene and anthracene, styryl aromatic ring derivatives such as 4,4'-bis(diphenylethenyl)biphenyl, perinone derivatives, coumarin derivatives, naphthalimide derivatives, quinone derivatives such as anthraquinone and diphenoquinone, phosphine oxide derivatives, arylnitrile derivatives, and indole derivatives. Examples of metal complexes having electron-accepting nitrogen include hydroxyazole complexes such as hydroxyphenyloxazole complexes, azomethine complexes, tropolone metal complexes, flavonol metal complexes, and benzoquinoline metal complexes. These materials can be used alone or in combination with different materials.

[0359] 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, benzoquinol, Examples of the derivatives 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.

[0360] Further, a metal complex having an electron-accepting nitrogen can also be used, and examples thereof include hydroxyazole complexes such as quinolinol metal complexes and hydroxyphenyloxazole complexes, azomethine complexes, tropolone metal complexes, flavonol metal complexes, and benzoquinoline metal complexes.

[0361] The above-mentioned materials may be used alone or in combination with different materials.

[0362] 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.

[0363] 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.

[0364] The electron transport layer or the electron injection layer may further contain a substance capable of reducing the material forming the electron transport layer or the electron injection layer. As the reducing substance, various substances can be used as long as they have a certain degree of reducing ability, and for example, at least one selected from the group consisting of alkali metals, alkaline earth metals, rare earth metals, oxides of alkali metals, halides of alkali metals, oxides of alkaline earth metals, halides of alkaline earth metals, oxides of rare earth metals, halides of rare earth metals, organic complexes of alkali metals, organic complexes of alkaline earth metals, and organic complexes of rare earth metals can be suitably used.

[0365] Preferred reducing substances include alkali metals such as Na (work function 2.36 eV), K (2.28 eV), Rb (2.16 eV) or Cs (1.95 eV) and alkaline earth metals such as Ca (2.9 eV), Sr (2.0 to 2.5 eV) or Ba (2.52 eV), and substances with a work function of 2.9 eV or less are particularly preferred. Among these, more preferred reducing substances are alkali metals such as K, Rb or Cs, more preferably Rb or Cs, and most preferably Cs. These alkali metals have particularly high reducing ability, and by adding a relatively small amount to the material forming the electron transport layer or electron injection layer, the luminance of the organic EL element can be improved and the life can be extended. Furthermore, as a reducing substance having a work function of 2.9 eV or less, a combination of two or more of these alkali metals is also preferred, and in particular, a combination containing Cs is preferred, for example, a combination of Cs and Na, Cs and K, Cs and Rb, or a combination of Cs, Na and K. By containing Cs, the reducing ability can be efficiently exhibited, and by adding it to a material forming an electron transport layer or an electron injection layer, the luminance of the organic EL element can be improved and the life span can be extended.

[0366] <2-1-8. Cathode in organic electroluminescent device> The cathode 108 serves to inject electrons into the light-emitting layer 105 through the electron injection layer 107 and the electron transport layer 106 .

[0367] The material for forming the cathode 108 is not particularly limited as long as it is a substance that can efficiently inject electrons into the organic layer, but the same material as the material for forming the anode 102 can be used. Among them, metals such as tin, indium, calcium, aluminum, silver, copper, nickel, chromium, gold, platinum, iron, zinc, lithium, sodium, potassium, cesium, and magnesium, or alloys thereof (magnesium-silver alloy, magnesium-indium alloy, aluminum-lithium alloy such as lithium fluoride / aluminum, etc.), etc. are preferable. In order to increase the electron injection efficiency and improve the device characteristics, lithium, sodium, potassium, cesium, calcium, magnesium, or alloys containing these low work function metals are effective. However, these low work function metals are generally unstable in the air. To improve this point, for example, a method is known in which a trace amount of lithium, cesium, or magnesium is doped into the organic layer to use a highly stable electrode. As other dopants, inorganic salts such as lithium fluoride, cesium fluoride, lithium oxide, and cesium oxide can also be used. However, they are not limited to these.

[0368] Further, for electrode protection, preferred examples include lamination of metals such as platinum, gold, silver, copper, iron, tin, aluminum, and indium, or alloys using these metals, inorganic substances such as silica, titania, and silicon nitride, polyvinyl alcohol, vinyl chloride, hydrocarbon polymer compounds, etc. The method of producing these electrodes is also not particularly limited as long as it can provide electrical continuity, and may be resistance heating, electron beam deposition, sputtering, ion plating, coating, or the like.

[0369] <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 form each layer alone, but they can also be used as a polymer binder by being dispersed in a solvent-soluble resin such as polyvinyl chloride, polycarbonate, polystyrene, poly(N-vinylcarbazole), polymethyl methacrylate, polybutyl methacrylate, polyester, polysulfone, polyphenylene oxide, polybutadiene, hydrocarbon resin, ketone resin, phenoxy resin, polyamide, ethyl cellulose, vinyl acetate resin, ABS resin, polyurethane resin, or a curable resin such as phenol resin, xylene resin, petroleum resin, urea resin, melamine resin, unsaturated polyester resin, alkyd resin, epoxy resin, silicone resin, or the like.

[0370] <2-1-10. Method for producing organic electroluminescent device> Each layer constituting an organic EL element can be formed by forming the material to be formed into a thin film by a method such as vapor deposition, resistance heating vapor deposition, electron beam vapor deposition, sputtering, molecular lamination, printing, inkjet, spin coating or casting, coating, etc. The thickness of each layer thus formed is not particularly limited and can be set appropriately according to the properties of the material, but is usually in the range of 2 nm to 5000 nm. The thickness of the film can usually be measured with a quartz crystal oscillation type film thickness measuring device, etc. When forming a thin film by vapor deposition, the vapor deposition conditions vary depending on the type of material, the desired crystal structure and association structure of the film, etc. The vapor deposition conditions are generally a boat heating temperature of +50 to +400°C, a vacuum degree of 10, and a vacuum of 10. -6 ~10 -3 It is preferable to appropriately set the pressure, pressure Pa, deposition rate 0.01 to 50 nm / sec, substrate temperature -150 to +300°C, and film thickness in the range of 2 nm to 5 µm.

[0371] Next, as an example of a method for producing an organic EL element, a method for producing an organic EL element consisting of an anode / hole injection layer / hole transport layer / light-emitting layer consisting of a host material and a dopant material / electron transport layer / electron injection layer / cathode will be described. After forming a thin film of an anode material on a suitable substrate by a deposition method or the like to produce an anode, thin films of a hole injection layer and a hole transport layer are formed on the anode. A host material and a dopant material are co-deposited on the anode to form a thin film to produce a light-emitting layer, an electron transport layer and an electron injection layer are formed on the light-emitting layer, and a thin film consisting of a cathode material is further formed by a deposition method or the like to produce a cathode, thereby obtaining a desired organic EL element. In the production of the above-mentioned organic EL element, the production order can also be reversed, and the elements can be produced in the order of a cathode, an electron injection layer, an electron transport layer, a light-emitting layer, a hole transport layer, a hole injection layer, and an anode.

[0372] When applying a DC voltage to the organic EL element obtained in this way, the anode should be set to + and the cathode to -. When a voltage of about 2 to 40 V is applied, light emission can be observed from the transparent or semi-transparent electrode side (anode or cathode, or both). This organic EL element also emits light when a pulse current or an AC current is applied. The waveform of the AC current applied may be any waveform.

[0373] <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 equipped with 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.

[0374] Examples of the display device include panel displays such as color flat panel displays, and flexible displays such as flexible color organic electroluminescent (EL) displays (see, for example, JP-A-10-335066, JP-A-2003-321546, JP-A-2004-281086, etc.). The display method of the display may be, for example, either one of a matrix method or a segment method. Note that the matrix display and the segment display may coexist in the same panel.

[0375] In a matrix, pixels for display are arranged two-dimensionally, such as in a grid or mosaic pattern, and a collection of pixels displays characters and images. The shape and size of the pixels are determined by the application. For example, square pixels with sides of 300 μm or less are usually used to display images and characters on computers, monitors, and televisions, and pixels with sides of mm order are used for large displays such as display panels. For monochrome display, pixels of the same color are arranged, but for color display, red, green, and blue pixels are displayed side by side. In this case, there are typically delta type and stripe type. The driving method for this matrix can be either line sequential driving method or active matrix. Line sequential driving has the advantage of being simpler in structure, but when considering the operating characteristics, active matrix may be superior, so it is necessary to use it according to the application.

[0376] In the segment type, a pattern is formed to display predetermined information, and a predetermined area is illuminated. Examples include time and temperature displays in digital clocks and thermometers, operating status displays in audio equipment and induction cookers, and panel displays in automobiles.

[0377] Examples of lighting devices include lighting devices for indoor lighting, backlights for liquid crystal display devices, etc. (see, for example, JP-A-2003-257621, JP-A-2003-277741, JP-A-2004-119211, etc.). Backlights are mainly used for the purpose of improving the visibility of non-self-luminous display devices, and are used in liquid crystal display devices, clocks, audio devices, automobile panels, display boards, signs, etc. In particular, for backlights for liquid crystal display devices, particularly for personal computers where thinning is an issue, backlights using organic EL elements are characterized by their thinness and light weight, considering that conventional methods are made up of fluorescent lamps and light guide plates and therefore difficult to make thin.

[0378] <2-2. Other organic devices> The polycyclic aromatic compound according to the present invention can be used for producing the organic electroluminescent device described above, as well as an organic field effect transistor or an organic thin-film solar cell.

[0379] An organic field-effect transistor is a transistor that controls current by an electric field generated by voltage input, and has a gate electrode in addition to a source electrode and a drain electrode. When a voltage is applied to the gate electrode, an electric field is generated, and the flow of electrons (or holes) flowing between the source electrode and the drain electrode can be arbitrarily blocked to control the current. Field-effect transistors are easier to miniaturize than simple transistors (bipolar transistors), and are often used as elements that make up integrated circuits.

[0380] The structure of an organic field effect transistor is usually such that a source electrode and a drain electrode are provided in contact with an organic semiconductor active layer formed using the polycyclic aromatic compound according to the present invention, and a gate electrode is provided sandwiching an insulating layer (dielectric layer) in contact with the organic semiconductor active layer. Examples of the element structure include the following structure. (1) Substrate / gate electrode / insulating layer / source and drain electrodes / organic semiconductor active layer (2) Substrate / gate electrode / insulating layer / organic semiconductor active layer / source electrode and drain electrode (3) Substrate / organic semiconductor active layer / source electrode / drain electrode / insulator layer / gate electrode (4) Substrate / source electrode / drain electrode / organic semiconductor active layer / insulator layer / gate electrode The organic field effect transistor thus configured can be used as a pixel driving switching element for an active matrix driving type liquid crystal display or an organic electroluminescence display.

[0381] The organic thin-film solar cell has a structure in which an anode such as ITO, a hole transport layer, a photoelectric conversion layer, an electron transport layer, and a cathode are laminated on a transparent substrate such as glass. The photoelectric conversion layer has a p-type semiconductor layer on the anode side and an n-type semiconductor layer on the cathode side. The polycyclic aromatic compound according to the present invention can be used as a material for a hole transport layer, a p-type semiconductor layer, an n-type semiconductor layer, and an electron transport layer depending on its physical properties. The polycyclic aromatic compound according to the present invention can function as a hole transport material or an electron transport material in an organic thin-film solar cell. In addition to the above, the organic thin-film solar cell may appropriately include a hole blocking layer, an electron blocking layer, an electron injection layer, a hole injection layer, a smoothing layer, and the like. The organic thin-film solar cell can be used by appropriately selecting and combining known materials used in organic thin-film solar cells.

[0382] <3. Wavelength conversion materials> The polycyclic aromatic compound of the present invention can be used as a wavelength converting material. Currently, the application of multi-color technology using color conversion methods to liquid crystal displays, organic electroluminescence displays, lighting, and the like is being actively studied. Color conversion refers to the wavelength conversion of light emitted from a light emitter to light with a longer wavelength, for example, converting ultraviolet light or blue light to green light or red light emission. By forming a wavelength conversion material with this color conversion function into a film and combining it with, for example, a blue light source, it becomes possible to extract the three primary colors of blue, green, and red from the blue light source, that is, to extract white light. By combining such a blue light source and a wavelength conversion film with a color conversion function as a light source unit, and combining it with a liquid crystal drive part and a color filter, it becomes possible to manufacture a full-color display. Furthermore, if there is no liquid crystal drive part, it can be used as a white light source as it is, and can be applied as a white light source for, for example, LED lighting. Furthermore, by using a blue organic electroluminescence element as a light source in combination with a wavelength conversion film that converts blue light into green light and red light, it becomes possible to manufacture a full-color organic electroluminescence display without using a metal mask. Furthermore, by using blue microLEDs as a light source in combination with a wavelength conversion film that converts blue light into green and red light, it is possible to create low-cost full-color microLED displays.

[0383] The polycyclic aromatic compound of the present invention can be used as this wavelength converting material. By using a wavelength converting material containing the polycyclic aromatic compound of the present invention, light from a light source or a light emitting element that generates ultraviolet light or shorter wavelength blue light can be converted into blue light or green light with high color purity suitable for use in a display device (a display device using an organic EL element or a liquid crystal display device). The converted color can be adjusted by appropriately selecting the substituent of the polycyclic aromatic compound of the present invention, the binder resin used in the wavelength converting composition described below, and the like. The wavelength converting material can be prepared as a wavelength converting composition containing the polycyclic aromatic compound of the present invention. In addition, a wavelength converting film may be formed using this wavelength converting composition.

[0384] The wavelength conversion composition may contain a binder resin, other additives, and a solvent in addition to the polycyclic aromatic compound of the present invention. As the binder resin, for example, those described in paragraphs 0173 to 0176 of WO 2016 / 190283 can be used. As the other additives, the compounds described in paragraphs 0177 to 0181 of WO 2016 / 190283 can be used. As the solvent, the description of the solvent contained in the composition for forming the light-emitting layer above can be referred to.

[0385] The wavelength conversion film includes a wavelength converting layer formed by curing the wavelength converting composition. Known film forming methods can be referred to as a method for producing a wavelength converting layer from a wavelength converting composition. The wavelength conversion film may consist only of a wavelength converting layer formed from a composition containing the polycyclic aromatic compound of the present invention, or may include other wavelength converting layers (e.g., a wavelength converting layer that converts blue light into green light or red light, or a wavelength converting layer that converts blue light or green light into red light). The wavelength conversion film may further include a substrate layer and a barrier layer for preventing deterioration of the color conversion layer due to oxygen, moisture, or heat. EXAMPLES

[0386] The present invention will be explained in more detail below with reference to examples, but the present invention is not limited to these. In the examples, APCI-MS means atmospheric pressure chemical ionization mass spectrometry.

[0387] <<Synthesis Example>> <Synthesis Example (1): Synthesis of Compound (1-007)> [ka]

[0388] Under a nitrogen atmosphere, 2,4-dibromophenol (120 g), phenylboronic acid (122 g), dichlorobis[di-t-butyl(4-dimethylaminophenyl)phosphino]palladium(II) (Pd-132) (3.37 g) as a palladium catalyst, potassium carbonate (98.8 g), cyclopentyl methyl ether (CPME) (480 ml), and water (480 mL) were placed in a flask and stirred at 80°C for 1 hour. After the reaction was completed, water and toluene were added to the reaction solution and stirred, and then the organic layer was separated and washed with water. The organic layer was then concentrated to obtain a crude product, which was purified with a silica gel short column (eluent: toluene) to obtain an intermediate (Int-1-007-1) (113 g).

[0389] [ka]

[0390] Under a nitrogen atmosphere, intermediate (Int-1-007-1) (95.0 g), bromoacetaldehyde diethyl acetal (98.8 g), potassium carbonate (107 g), and N-methylpyrrolidone (NMP) (475 ml) were placed in a flask and stirred at 180°C for 1 hour. After the reaction was completed, water and ethyl acetate were added to the reaction solution and stirred, and then the organic layer was separated and washed with water. The organic layer was then concentrated to obtain a crude product, which was purified with a silica gel short column (eluent: ethyl acetate / heptane = 1 / 5 (volume ratio)) to obtain intermediate (Int-1-007-2) (138 g).

[0391] [ka]

[0392] Under a nitrogen atmosphere, polyphosphoric acid (PPA) (387 g) was placed in a flask and heated to 90°C. A solution of intermediate (Int-1-007-2) (129 g) in chlorobenzene (645 mL) was added dropwise thereto and stirred at 100°C for 1 hour. After the reaction was completed, water and toluene were added to the reaction solution and stirred, and then the organic layer was separated and washed with water. The organic layer was then concentrated to obtain a crude product, which was purified with a silica gel short column (eluent: toluene / heptane = 1 / 5 (volume ratio)). It was further recrystallized from an ethanol / heptane mixture to obtain intermediate (Int-1-007-3) (38.3 g).

[0393] [ka]

[0394] Under a nitrogen atmosphere, the intermediate (Int-1-007-3) (35.0 g), potassium acetate (22.8 g), and chloroform (150 mL) were placed in a flask and cooled to 0°C. A solution of bromine (22.8 g) in chloroform (25 mL) was slowly added dropwise thereto, and the mixture was stirred for 30 minutes while returning to room temperature. After the reaction was completed, an aqueous solution of sodium sulfite was 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 with a silica gel short column (eluent: heptane) to obtain the intermediate (Int-1-007-4) (50.1 g).

[0395] [ka]

[0396] Under a nitrogen atmosphere, the intermediate (Int-1-007-4) (45.0 g), potassium hydroxide (6.19 g), and ethanol (450 mL) were placed in a flask and stirred at 0°C for 1 hour. After the reaction was completed, water and toluene were added to the reaction solution and stirred, and then 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)) to obtain the intermediate (Int-1-007-5) (23.1 g).

[0397] [ka]

[0398] Under a nitrogen atmosphere, intermediate (Int-1-007-5) (20.0 g), 4-(tert-butyl)aniline (8.97 g), Pd-132 (0.811 g) as a palladium catalyst, tBuONa (8.26 g), and toluene (200 ml) were placed in a flask and stirred at reflux temperature for 2 hours. After the reaction was completed, water and toluene were added to the reaction solution and stirred, and then the organic layer was separated and washed with water. The organic layer was then concentrated to obtain a crude product, which was purified with a silica gel short column (eluent: toluene / heptane = 1 / 4 (volume ratio)) to obtain intermediate (Int-1-007-6) (22.8 g).

[0399] [ka]

[0400] Under a nitrogen atmosphere, intermediate (Int-1-007-7) (30.0 g), 5-(tert-butyl)-1,2,3-trichlorobenzene (13.1 g), Pd-132 (0.780 g) as a palladium catalyst, tBuONa (7.94 g), and toluene (300 ml) were placed in a flask and stirred at reflux temperature for 2 hours. After the reaction was completed, water and toluene were added to the reaction solution and stirred, and then the organic layer was separated and washed with water. The organic layer was then concentrated to obtain a crude product, which was purified with a silica gel short column (eluent: toluene / heptane = 1 / 9 (volume ratio)). It was further recrystallized from ethanol to obtain intermediate (Int-1-007-8) (36.9 g).

[0401] [ka]

[0402] Under a nitrogen atmosphere, intermediate (Int-1-007-8) (30.0 g), intermediate (Int-1-007-6) (16.8 g), Pd-132 (0.570 g) as a palladium catalyst, tBuONa (5.80 g), and toluene (300 ml) were placed in a flask and stirred at reflux temperature for 4 hours. After the reaction was completed, water and ethyl acetate were added to the reaction solution and stirred, and then the organic layer was separated and washed with water. The organic layer was then concentrated to obtain a crude product, which was purified with a silica gel short column (eluent: toluene / heptane = 1 / 3 (volume ratio)) to obtain intermediate (Int-1-007) (32.1 g).

[0403] [ka]

[0404] A 1.60M t-butyllithium pentane solution (13.9ml) was added to a flask containing intermediate (Int-1-007) (12.5g) and t-butylbenzene (125ml) under a nitrogen atmosphere at 0°C. After the dropwise addition, the temperature was raised to 70°C and stirred for 0.5 hours, and then components with a boiling point lower than that of t-butylbenzene were distilled off under reduced pressure. The mixture was cooled to -50°C and boron tribromide (5.56g) was added, and the mixture was heated to room temperature and stirred for 0.5 hours. Then, the mixture was cooled again to 0°C and N,N-diisopropylethylamine (2.87g) was added, and the mixture was stirred at room temperature until the heat generation subsided, and then the mixture was heated to 70°C and stirred for 1 hour. The reaction solution was cooled to room temperature, and an 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 with a silica gel short column (eluent: toluene / heptane = 1 / 2 (volume ratio)). The obtained crude product was recrystallized from toluene to obtain compound (1-007) (2.68 g).

[0405] [ka] APCI-MS confirmed that the compound had m / z (M+H) = 1100.57 and was the target compound.

[0406] <Synthesis Example (2): Synthesis of Compound (1-058)> Compound (1-058) was obtained from intermediate (Int-1-058) in the same manner as in Synthesis Example (1). [ka] APCI-MS confirmed that the compound had m / z (M+H) = 1136.67.

[0407] <Synthesis Example (3): Synthesis of Compound (1-134)> Compound (1-134) was obtained from intermediate (Int-1-134) in the same manner as in Synthesis Example (1). [ka] APCI-MS confirmed that the compound had m / z (M+H) = 1024.54.

[0408] <Synthesis Example (4): Synthesis of Compound (1-136)> Compound (1-136) was obtained from intermediate (Int-1-136) in the same manner as in Synthesis Example (1). [ka] APCI-MS confirmed that the compound had m / z (M+H) = 1080.60 and was the target compound.

[0409] <Synthesis Example (5): Synthesis of Compound (1-166)> Compound (1-166) was obtained from intermediate (Int-1-166) in the same manner as in Synthesis example (1). [ka] APCI-MS confirmed that the compound had m / z (M+H) = 1109.75.

[0410] <Synthesis Example (6): Synthesis of Compound (1-201)> Compound (1-201) was obtained from intermediate (Int-1-201) in the same manner as in Synthesis Example (1). [ka] APCI-MS confirmed that the compound had m / z (M+H) = 1024.54.

[0411] <Synthesis Example (7): Synthesis of Compound (1-179)> Compound (1-179) was obtained from intermediate (Int-1-179) in the same manner as in Synthesis Example (1). [ka] APCI-MS confirmed that the compound had m / z (M+H) = 1076.61 and was the target compound.

[0412] <Synthesis Example (8): Synthesis of Compound (1-191)> Compound (1-191) was obtained from intermediate (Int-1-191) in the same manner as in Synthesis Example (1). [ka] APCI-MS confirmed that this was the target compound with m / z (M+H) = 997.66.

[0413] <Synthesis Example (9): Synthesis of Compound (1-501)> Compound (1-501) was obtained from intermediate (Int-1-501) in the same manner as in Synthesis Example (1). [ka] APCI-MS confirmed that this was the target compound with m / z (M+H) = 925.56.

[0414] <Synthesis Example (10): Synthesis of Compound (1-502)> Compound (1-502) was obtained from intermediate (Int-1-502) in the same manner as in Synthesis Example (1). [ka] APCI-MS confirmed that the compound had m / z (M+H) = 913.50 and was the target compound.

[0415] <<Fabrication and evaluation of evaporated organic EL devices>> The compounds of the present invention have a suitable energy gap (Eg), high triplet excitation energy (E T ) and a small ΔEST, they are expected to be useful for, for example, light-emitting layers and charge-transporting layers, and are particularly expected to be useful for light-emitting layers. Next, the preparation and evaluation of an organic EL device using the polycyclic aromatic compound of the present invention will be described.

[0416] <Structure of organic EL element> The material configurations of the layers in the organic EL devices of Examples B1 to B10 and Comparative Example B1 are shown in Table 1 below.

[0417] [Table 1]

[0418] The chemical structures of "HI", "HAT-CN", "HT-1", "HT-2", "BH", "ET-1", "ET-2", "BH", "Liq", and "Comparative Compound (1)" (the compound described in Korean Patent Application Publication No. 2022 / 0113279) in Tables 1 and 3 are shown below.

[0419] [ka]

[0420] [ka]

[0421] <Element of Example B1> A 26 mm × 28 mm × 0.7 mm glass substrate (manufactured by Optoscience Co., Ltd.) on which an ITO film having a thickness of 180 nm was formed by sputtering and polished to 150 nm was used as a transparent support substrate. This transparent support substrate was fixed to a substrate holder of a commercially available deposition device (manufactured by Showa Vacuum Co., Ltd.), and a molybdenum deposition boat containing HI, HAT-CN, HT-1, HT-2, BH, compound (1-007), ET-1, and ET-2, and an aluminum nitride deposition boat containing Liq, LiF, and aluminum, were attached.

[0422] 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 first, HI was heated and evaporated to a thickness of 40 nm, then HAT-CN was heated and evaporated to a thickness of 5 nm, then HT-1 was heated and evaporated to a thickness of 45 nm, and then HT-2 was heated and evaporated to a thickness of 10 nm to form a hole layer consisting of four layers. Next, BH and compound (1) were heated simultaneously and evaporated to a thickness of 25 nm to form an emitting layer. The evaporation rate was adjusted so that the mass ratio of BH to compound (1) was approximately 97:3. Furthermore, ET-1 was heated and evaporated to a thickness of 5 nm, and then ET-2 and Liq were heated simultaneously and evaporated to a thickness of 25 nm to form an electron layer consisting of two layers. The evaporation rate was adjusted so that the mass ratio of ET-2 to Liq was approximately 50:50. The evaporation rate of each layer was 0.01 to 1 nm / sec. Thereafter, LiF was heated and evaporated at a deposition rate of 0.01 to 0.1 nm / sec to a thickness of 1 nm, and then aluminum was heated and evaporated to a thickness of 100 nm to form a cathode, thereby obtaining an organic EL device.

[0423] <Elements of Examples B2 to B10 and Comparative Example B1> Organic EL devices of Examples B2 to B10 and Comparative Example B1 were obtained in the same manner as in Example 1, except that each dopant material shown in Table 2 or Table 3 was used instead of compound (1).

[0424] <Evaluation of organic electroluminescence characteristics> For the organic EL devices of Examples B1 to B10 and Comparative Example B1, 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, the external quantum efficiency, and the device lifetime were measured. 2 It is the time during which 95% or more of the initial luminance is maintained when the device is continuously driven at the voltage for emitting light. The results are shown in Tables 2 and 3.

[0425] The quantum efficiency of a light-emitting element includes internal quantum efficiency and external quantum efficiency, and the internal quantum efficiency indicates the ratio of external energy injected as electrons (or holes) into the light-emitting layer of the light-emitting element that is converted purely into photons. On the other hand, the external quantum efficiency is calculated based on the amount of these photons that are emitted to the outside of the light-emitting element, and since some of the photons generated in the light-emitting layer are absorbed or continue to be reflected inside the light-emitting element and are not emitted to the outside of the light-emitting element, the external quantum efficiency is lower than the internal quantum efficiency.

[0426] The external quantum efficiency was measured as follows: The luminance of the element was 1000 cd / m using an Advantest voltage / current generator R6144. 2 The element is made to emit light by applying a voltage that results in a value of 10 ...

[0427] [Table 2]

[0428] [Table 3]

[0429] 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 it will be understood by those skilled in the art that they are similarly excellent materials for organic EL devices. [Industrial Applicability]

[0430] The polycyclic aromatic compound of the present invention is useful as a material for organic devices, particularly as a material for forming a light-emitting layer of an organic electroluminescent device. By using the polycyclic aromatic compound of the present invention as a dopant for the light-emitting layer, an organic electroluminescent device having a long life, a low driving voltage, and high efficiency light emission, particularly a long life, can be obtained. [Explanation of symbols]

[0431] 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< / l>

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 are each independently hydrogen or a substituent; R c1 ~R c4 at least two of are independently a substituent and the others are hydrogen; 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; L is > N-R NL , >O, >C(-R CL ) 2 , >Si(-R IL ) 2 , >S, or >Se; R NL , R CL , and R IL are each independently hydrogen, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted alkyl, or substituted or unsubstituted cycloalkyl; CL may be bonded to each other to form a ring, and two R IL may be bonded to each other to form a ring; X 1 and X 2 are each independently >O, >N-R NX , >C(-R CX ) 2 , >Si(-R IX ) 2 , >S, or >Se; R NX is hydrogen, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted alkyl, or substituted or unsubstituted cycloalkyl; R CX 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, 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 linked to R a3 and / or R b1 , or R a1 and / or R c4 may be combined with; 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 -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. R c1 ~R c4 2. The polycyclic aromatic compound according to claim 1, wherein at least one of the groups is a substituted or unsubstituted aryl, and at least one of the groups is a substituted or unsubstituted aryl or alkyl.

3. R c1 ~R c4 The polycyclic aromatic compound according to claim 1 , wherein at least two of the groups are each independently a substituted or unsubstituted aryl.

4. X 1 and X 2 However, both are >N-R NX and 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 4. The polycyclic aromatic compound according to claim 3, wherein the aryl or heteroaryl ring is optionally condensed with at least one cycloalkane.

5. R NX are each independently phenyl which may be substituted with alkyl or cycloalkyl, or 2-biphenylyl which may be substituted with alkyl or cycloalkyl, R NX 5. The polycyclic aromatic compound according to claim 4, wherein the aryl ring is optionally condensed with at least one cycloalkane.

6. The polycyclic aromatic compound according to any one of claims 1 to 5, wherein L is >O.

7. R a1 ~R a3 The polycyclic aromatic compound according to any one of claims 1 to 5, wherein each of the is independently hydrogen or unsubstituted alkyl.

8. R a1 and R a3 are all hydrogen, R a2 The polycyclic aromatic compound according to any one of claims 1 to 5, wherein is hydrogen or unsubstituted alkyl.

9. R b1 ~R b4 Of these, R b2 Or R b3 are each independently a substituent and the others are 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 are hydrogen; 【Chemistry 2】 In each of formulae (B11) and (B12), Me is methyl, and * indicates the bonding position.

10. The polycyclic aromatic compound according to claim 1, represented by any one of the following formulas: 【Chemistry 3】 In the formula, Me is methyl and tBu is t-butyl.

11. A material for an organic device, comprising the polycyclic aromatic compound according to any one of claims 1 to 5.

12. An organic electroluminescence device comprising a pair of electrodes consisting of an anode and a cathode, and a light-emitting layer disposed between the pair of electrodes, the light-emitting layer containing the polycyclic aromatic compound according to any one of claims 1 to 5.

13. The organic electroluminescent device according to claim 12 , wherein the light-emitting layer comprises a host and the polycyclic aromatic compound as a dopant.

14. The organic electroluminescent device according to claim 13 , wherein the host is an anthracene compound, a fluorene compound, or a dibenzochrysene compound.

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

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