Polycyclic aromatic compounds

Abstract

To provide a novel compound useful as an organic device material for an organic EL element or the like.SOLUTION: There is provided a polycyclic aromatic compound having a structure comprising a structural unit represented by a following formula (1): (wherein, A ring and B ring each independently are a substituted or unsubstituted aryl ring or a substituted or unsubstituted heteroaryl ring, C ring is a substituted or unsubstituted hetero ring or a hydrocarbbon ring, X1 is>N-R (R is an aryl or the like), a broken line represents a divalent group connecting two nitrogen atoms and at least one hydrogen in the structure may be replaced by cyano, halogen or deuterium.)SELECTED DRAWING: None

Description

[Technical Field]

[0001] This invention relates to polycyclic aromatic compounds. In particular, this invention relates to polycyclic aromatic compounds containing nitrogen and boron. This invention also relates to materials for organic devices, organic electroluminescent devices, and display devices and lighting devices containing the above-mentioned polycyclic aromatic compounds. [Background technology]

[0002] Conventionally, display devices using electroluminescent light-emitting elements have been studied extensively due to their potential for power saving and miniaturization. Furthermore, organic electroluminescent elements made from organic materials have been actively investigated because they are easily made lighter and larger. In particular, the development of organic materials with luminescence properties such as blue, one of the three primary colors of light, and the development of organic materials with charge transport capabilities (potentially becoming semiconductors or superconductors) have been actively researched, regardless of whether they are polymer compounds or low molecular weight compounds.

[0003] An organic electroluminescent device has a structure consisting of a pair of electrodes, 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 light-emitting layers and charge transport / injection layers that transport or inject charges such as holes and electrons, and various organic materials suitable for these layers have been developed.

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

[0005] [Patent Document 1] International Publication No. 2015 / 102118 [Overview of the project] [Problems that the invention aims to solve]

[0006] As mentioned above, various materials have been developed for use in organic EL devices, but in order to increase the range of materials available for organic EL devices, there is a need for the development of materials composed of compounds different from those used in conventional devices. The object of this invention is to provide novel compounds useful as organic device materials such as organic EL elements. [Means for solving the problem]

[0007] The present inventors diligently studied to solve the above problems and succeeded in producing a novel polycyclic aromatic compound that has superior luminescence properties, similar to the compound described in Patent Document 1, but containing boron. Furthermore, they discovered that an excellent organic EL element can be obtained by arranging a layer containing this polycyclic aromatic compound between a pair of electrodes to construct an organic EL element, thus completing the present invention. In other words, the present invention provides the following polycyclic aromatic compounds, and further, materials for organic devices containing the following polycyclic aromatic compounds.

[0008] <1> Polycyclic aromatic compounds having a structure containing a structural unit represented by the following formula (1); [ka]

[0009] In formula (1), Rings A and B are independently substituted or unsubstituted aryl rings or substituted or unsubstituted heteroaryl rings. The C ring is a substituted or unsubstituted hydrocarbon ring or a substituted or unsubstituted heteroring. X 1>O, >NR, >C(-R)2, >Si(-R)2, >S, or >Se, where R in >NR is hydrogen, a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted alkyl, or a substituted or unsubstituted cycloalkyl, where R in >C(-R)2 and >Si(-R)2 are independently hydrogen, a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted alkyl, or a substituted or unsubstituted cycloalkyl, where the two Rs in >C(-R)2 and >Si(-R)2 may be bonded to each other to form a ring, where R in >NR, >C(-R)2, and >Si(-R)2 may be bonded to the A and / or B rings by linking groups or single bonds. The dashed line represents a divalent group connecting two nitrogen atoms, and this divalent group may be bonded to the A ring and / or the C ring. In the above structure, at least one of the aryl ring or heteroaryl ring may be condensed with at least one cycloalkane, the cycloalkane may be substituted with at least one substituent, and at least one -CH2- in the cycloalkane may be replaced with -O-. At least one hydrogen atom in the above structure may be replaced with a cyano, halogen, or deuterium.

[0010] <2> The divalent group connecting the two nitrogen atoms is represented by the following formula: <1> Polycyclic aromatic compounds as described above; [ka]

[0011] The D ring is a substituted or unsubstituted hydrocarbon ring or a substituted or unsubstituted heteroring, and the two asterisks indicate the bond positions with two nitrogen atoms. The D ring may be further bonded to the A ring and / or the C ring by linking groups or single bonds.

[0012] <3> It can be represented by any of the following formulas selected from the group consisting of formulas (1-a), (1-b), (1-c), (1-d), (1-f), (1-g), (1-h), and (1-i): <2> Polycyclic aromatic compounds as described above; [ka]

[0013] In equations (1-a), (1-b), (1-c), (1-d), (1-f), (1-g), (1-h), and (1-i), Each Z is independent of N or CR. Z And R Z Each of these is independently a hydrogen atom or a substituent selected from substituent group Z. Two adjacent R Z These elements may bond to each other to form an aryl ring or a heteroaryl ring, and the formed aryl ring or heteroaryl ring may each be substituted with any substituent selected from substituent group Z. Each of Z=Z may independently be >O, >NR, >C(-R)2, >Si(-R)2, >S, or >Se, and each of the R in >NR, >C(-R)2, and >Si(-R)2 may independently be hydrogen, a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted alkyl, or a substituted or unsubstituted cycloalkyl, and the two Rs in >C(-R)2 and >Si(-R)2 may be bonded to each other to form a ring. X 2 and X 4Each of these is independently >O, >NR, >C(-R)2, >S, or >Se, where R in >NR is hydrogen, a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted alkyl, or a substituted or unsubstituted cycloalkyl, and each of the R in >C(-R)2 is independently hydrogen, a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted alkyl, or a substituted or unsubstituted cycloalkyl, and both >NR and >C(-R)2 may be bonded at R to one or more Zs bonded to the same carbon atom. In the above structure, at least one of the aryl ring or heteroaryl ring may be condensed with at least one cycloalkane, the cycloalkane may be substituted with at least one substituent, and at least one -CH2- in the cycloalkane may be replaced with -O-. At least one hydrogen atom in the above structure may be replaced with cyano, halogen, or deuterium; The substituent group Z is, An aryl which may be substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl, and cycloalkyl, A heteroaryl which may be substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl, and cycloalkyl, Diarylaminos which may be substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl, and cycloalkyl (the two aryls may be linked to each other via a linking group), A diheteroarylamino (where two heteroaryls may be linked to each other via a linking group) may be substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl, and cycloalkyl. arylheteroarylamino optionally substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl and cycloalkyl (aryl and heteroaryl may be bonded to each other via a linking group), diarylboryl optionally substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl and cycloalkyl (two aryl groups may be bonded via a single bond or a linking group), alkyl optionally substituted with at least one group selected from the group consisting of aryl, heteroaryl and cycloalkyl, cycloalkyl optionally substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl and cycloalkyl, alkoxy optionally substituted with at least one group selected from the group consisting of aryl, heteroaryl and cycloalkyl, aryloxy optionally substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl and cycloalkyl, and substituted silyl.

[0014] <4>all Z are C-R Z , and X 2 are all >N-R, and X 4 is >O, >N-R, or >S, the polycyclic aromatic compound according to <3>. <5>R Z are each independently hydrogen, alkyl, phenyl optionally substituted with alkyl, diphenylamino optionally substituted with alkyl, or carbazolyl optionally substituted with alkyl, the polycyclic aromatic compound according to <3> or <4>. <6>represented by any formula selected from the group consisting of formula (1-f), formula (1-g), formula (1-h), and formula (1-i), the polycyclic aromatic compound according to any one of <3> to <5>.

[0015] <7> It can be expressed by one of the following formulas <1> Polycyclic aromatic compounds as described above; [ka] In the formula, tBu is t-butyl.

[0016] <8> It can be represented by any of the following formulas selected from the group consisting of formulas (1-a), (1-b), (1-c), and (1-d): <3> ~ <5> A polycyclic aromatic compound as described in any of the following: A polycyclic aromatic compound comprising at least one substructure represented by any formula selected from the group consisting of formulas (B101), (B102), (B103), (B104), (B105), (B106), (B107), and (B108); [ka]

[0017] During the ceremony, Z is synonymous with Z in equations (1-a), (1-b), (1-c), and (1-d), X 5 is >O, >NR, >C(-R)2, >S, or >Se, where R in >NR is hydrogen, a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted alkyl, or a substituted or unsubstituted cycloalkyl, where R in >C(-R)2 is independently hydrogen, a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted alkyl, or a substituted or unsubstituted cycloalkyl, where the two Rs in >C(-R)2 may be bonded to each other to form a ring, and n is an integer from 1 to 3. Me stands for methyl.

[0018] <9> It can be expressed by one of the following formulas <8> Polycyclic aromatic compounds as described above; [ka]

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

[0020] <10> Polycyclic aromatic compounds having a structure containing a structural unit represented by formula (2); [ka]

[0021] In formula (2), Each Z is independent of N or CR. Z And R Z Each of these is independently a hydrogen atom or a substituent selected from substituent group Z. Two adjacent R Z These elements may bond to each other to form an aryl ring or a heteroaryl ring, and the formed aryl ring or heteroaryl ring may each be substituted with any substituent selected from substituent group Z. R Z and adjacent R Z At least one of the substituents of the ring formed by the bonding of these groups is a group represented by a formula selected from the group consisting of formulas (A-1), (A-2), and (A-3), Each of Z=Z may independently be >O, >NR, >C(-R)2, >Si(-R)2, >S, or >Se, and each of the R in >NR, >C(-R)2, and >Si(-R)2 may independently be hydrogen, a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted alkyl, or a substituted or unsubstituted cycloalkyl, and the two Rs in >C(-R)2 and >Si(-R)2 may be bonded to each other to form a ring. In formula (A-1), W 1 and W 2 These are independent single bonds, >C(-R W)2, >NR W ,>O,>Si(-R W )2, >S, >SO or >SO2, The aforementioned >NR W R W is any substituent selected from substituent group Z, a group represented by formula (A-2), or a group represented by formula (A-3), Above>C(-R W )2, >Si(-R W )2 R W Each of these is independently a hydrogen atom, a substituent selected from substituent group Z, a group represented by formula (A-2), or a group represented by formula (A-3). R, which bonds with the same element W They may be connected to each other, The aforementioned >NR W ,>C(-R W )2, >Si(-R W )2 R W Each of them may be independently coupled to at least one Y, Y is N or CR Y And R Y Each of these is independently a hydrogen atom, a substituent selected from substituent group Z, a group represented by formula (A-2), or a group represented by formula (A-3). R in adjacent Y Y These elements may be bonded to each other to form an aryl ring or a heteroaryl ring, and the formed ring may have any substituent selected from substituent group Z, a group represented by formula (A-2), or a group represented by formula (A-3). L 1 is a single bond or linking group, L 1 is R Y Using as a connecting point, any CR Y Is it bonded to C, or R W Using as the coupling >C(-R W )2 C, >NR W N, >O, >Si(-R W )Bonded to Si in 2, or R in Y Y They are bonded to the ring-constituting atoms of the ring formed by the bonding of each other, * indicates the bonding position of the group represented by formula (A-1), In formula (A-2), Y is N or CR Y And R Y Each of these is independently a hydrogen atom, a substituent selected from substituent group Z, a group represented by formula (A-1), or a group represented by formula (A-3). R in adjacent Y Y These elements may be bonded to each other to form an aryl ring or a heteroaryl ring, and the formed ring may have any substituent selected from substituent group Z, a group represented by formula (A-1), or a group represented by formula (A-3). L 2 is a single bond or linking group, L 2 is R Y Using as a connecting hand, any CR Y It is bonded to C in Y, or R in Y Y They are bonded to the ring-constituting atoms of the ring formed by the bonding of each other, * indicates the bonding position of the group represented by formula (A-2). In formula (A-3), Ar 3 Each of these is independently an aryl which may be substituted with at least one substituent selected from substituent group Z or a group represented by formula (A-1) or (A-2), a heteroaryl which may be substituted with at least one substituent selected from substituent group Z or a group represented by formula (A-1) or (A-2), or a group represented by formula (A-1) or (A-2), W 3 is Si, P, or S, W 3 When is Si, then m is 3 and n is 0, and W 3 When P is, then m is 2 and n is 0 or 1, and W 3 When S is true, m is 1 and n is an integer between 0 and 2. L 3 is a single bond or linking group, * indicates the bonding position of the group represented by formula (A-3). In the above structure, at least one of the aryl ring or heteroaryl ring may be condensed with at least one cycloalkane, at least one hydrogen in the cycloalkane may be substituted, and at least one -CH2- in the cycloalkane may be substituted with -O-. At least one hydrogen atom in the above structure may be replaced with cyano, halogen, or deuterium; The substituent group Z is, An aryl which may be substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl, and cycloalkyl, A heteroaryl which may be substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl, and cycloalkyl, Diarylaminos which may be substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl, and cycloalkyl (the two aryls may be linked to each other via a linking group), A diheteroarylamino (where two heteroaryls may be linked to each other via a linking group) may be substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl, and cycloalkyl. An arylheteroarylamino (aryl and heteroaryl may be linked to each other via linking groups) may be substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl, and cycloalkyl. Diarylboryl (the two aryl groups may be linked by a single bond or a linking group) which may be substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl, and cycloalkyl groups. Alkyls which may be substituted with at least one group selected from the group consisting of aryl, heteroaryl, and cycloalkyl groups, A cycloalkyl group which may be substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl, and cycloalkyl groups. An alkoxy which may be substituted with at least one group selected from the group consisting of aryl, heteroaryl, and cycloalkyl groups. Aryloxys which may be substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl and cycloalkyl, and It consists of substituted silyls.

[0022] <11> L 1 , L 2 and L 3 However, each is independently an arylene which may be substituted with a single bond or an aryl or heteroaryl bond, a heteroarylene which may be substituted with an aryl or heteroaryl bond, >NR L ,>O,>C(-R L )2, >Si(-R L )2, >S, >Se and a linking group selected from the group consisting of two or more combinations thereof, L 1 , L 2 and L 3 Inside >NR L ,>C(-R L )2 and >Si(-R L )R in 2 L Each of these is independently a hydrogen atom, one of the substituents selected from substituent group Z, or a group represented by formula (A-1), formula (A-2), or formula (A-3), and is bonded to the same element R L They may be bonded to each other, <10> The polycyclic aromatic compounds described above. <11-2>In formula (2), R Z One or two of are bases represented by formulas selected from the group consisting of formulas (A-1), (A-2), and (A-3), where R Z If they are bonded together to form a ring, then the substituents of that ring and R Z One or two selected from the group consisting of and are bases represented by formulas selected from the group consisting of formulas (A-1), (A-2), and (A-3). <10> or <11> The polycyclic aromatic compounds described above.

[0023] <12>In Formula (2), R Z , at least one of which is a group represented by Formula (A-1), provided that when R Z are bonded to each other to form a ring, at least one selected from the group consisting of a substituent of the ring and R Z is a group represented by Formula (A-1), W 1 is >N-R W , >C(-R W )2, >O, >Si(-R W )2 or >S, and W 2 is a single bond. The polycyclic aromatic compound according to any one of <10> to <11> and <11-2>. <13>L 1 is a single bond, and W 1 is >N-R W , L 1 is bonded, using R W as a bonding hand, to the N of >N-R W , The polycyclic aromatic compound according to <12>, comprising at least one R Y that is a group represented by Formula (A-2), a group represented by Formula (A-3), or N-carbazolyl. <14>In Formula (2), R Z , at least one of which is a group represented by Formula (A-2), provided that when R Z are bonded to each other to form a ring, at least one selected from the group consisting of a substituent of the ring and R Z is a group represented by Formula (A-2), The polycyclic aromatic compound according to any one of <10> to <13> and <11-2>, wherein the group represented by Formula (A-2) comprises, as a partial structure, a pyridine ring, a pyrimidine ring, a pyrazine ring, or a triazine ring. <15>In Formula (2), R Z , at least one of which is a group represented by Formula (A-3), provided that when R Z are bonded to each other to form a ring, at least one selected from the group consisting of a substituent on the ring and R Z is a group represented by Formula (A-3), W 3is Si, <10> ~ <14> A polycyclic aromatic compound as described in either <11-2>.

[0024] <16> It can be expressed by one of the following formulas <13> The polycyclic aromatic compounds described above. [ka]

[0025] <17> <1> ~ <16> A material for organic devices containing a polycyclic aromatic compound as described in either <11-2>. <18> The device has a pair of electrodes consisting of an anode and a cathode, and an organic layer (preferably a light-emitting layer) disposed between the pair of electrodes, wherein the organic layer <1> ~ <16> An organic electroluminescent element containing a polycyclic aromatic compound as described in either <11-2>. <19> It has 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 is made of a host material and <1> ~ <9> It contains a polycyclic aromatic compound as described in any of the following: An organic field light-emitting element in which the lowest excited triplet energy level of the host material is higher than the lowest excited triplet energy level of the polycyclic aromatic compound. <20> The device comprises a pair of electrodes consisting of an anode and a cathode, and a light-emitting layer disposed between the pair of electrodes, wherein the light-emitting layer comprises at least two selected from the group consisting of a hole-transporting host material, an electron-transporting host material, and an assisting dopant, and an emitting dopant. The aforementioned emitting dopant <1> ~ <9> An organic field light-emitting element that is a polycyclic aromatic compound as described in any of the following. <21> It has a pair of electrodes consisting of an anode and a cathode, and a light-emitting layer disposed between the pair of electrodes, The aforementioned light-emitting layer is a dopant material and a host material <10> ~ <16> , comprising a polycyclic aromatic compound as described in any of <11-2>, An organic field light-emitting element in which the lowest excited triplet energy level of the polycyclic aromatic compound is higher than the lowest excited triplet energy level of the dopant material. <22> <18> ~ <21> A display device or lighting device equipped with an organic electroluminescent element as described in any of the above. [Effects of the Invention]

[0026] The present invention provides novel polycyclic aromatic compounds useful as materials for organic devices such as organic electroluminescent devices. The polycyclic aromatic compounds of the present invention can be used in the manufacture of organic devices such as organic electroluminescent devices. [Brief explanation of the drawing]

[0027] [Figure 1] This is a schematic cross-sectional view showing an example of an organic field light-emitting device. [Figure 2] This is an energy level diagram showing the energy relationships between the host, assisting dopant, and emitting dopant of a TAF device using a common fluorescent dopant. [Figure 3] This is an energy level diagram showing an example of the energy relationship between the host, assisting dopant, and emitting dopant in an organic electroluminescent element according to one aspect of the present invention. [Modes for carrying out the invention]

[0028] The present invention will be described in detail below. The following descriptions of constituent elements may be based on representative embodiments and specific examples, but the present invention is not limited to such embodiments. In this specification, numerical ranges represented by "~" mean a range that includes the numbers written before and after "~" as the lower and upper limits. Also, in this specification, "hydrogen" in the description of structural formulas means "hydrogen atom (H)". Similarly, "carbon atom (C)" may be referred to as "carbon". In this specification, "adjacent groups" refers to two groups that are bonded to two adjacent atoms in the structural formula (two atoms directly bonded by a covalent bond).

[0029] In this specification, "Me" represents methyl, "Et" represents ethyl, "nBu" represents n-butyl (n-butyl), "tBu" represents t-butyl (tert-butyl), "iBu" represents isobutyl, "secBu" represents secondary butyl, "nPr" represents n-propyl (n-propyl), "iPr" represents isopropyl, "tAm" represents t-amyl, "2EH" represents 2-ethylhexyl, "tOct" represents t-octyl, "Ph" represents phenyl, "Mes" represents mesityl (2,4,6-trimethylphenyl), "Ad" represents 1-adamantyl, "Tf" represents trifluoromethanesulfonyl, "TMS" represents trimethylsilyl, and "D" represents deuterium. In this specification, an organic electroluminescent element may be referred to as an organic EL element.

[0030] In this specification, chemical structures and substituents are sometimes expressed in terms of carbon number. However, when a substituent is substituted into a chemical structure, or when a substituent is further substituted into another substituent, the carbon number refers to the carbon number of the chemical structure and the substituent itself, and does not refer to the total carbon number of the chemical structure and substituent, or the total carbon number of the substituents. For example, "substituent B with carbon number Y substituted by substituent A with carbon number X" means that "substituent A with carbon number X" is substituted into "substituent B with carbon number Y," and carbon number Y is not the total carbon number of substituent A and substituent B. Also, for example, "substituent B with carbon number Y substituted by substituent A" means that "substituent A (without carbon number limitation)" is substituted into "substituent B with carbon number Y," and carbon number Y is not the total carbon number of substituent A and substituent B.

[0031] 0. Description of rings and substituents First, the details of the rings and substituents used in this specification are described below.

[0032] As used herein, the "hydrocarbon ring" includes, in addition to the "aryl ring" described later, a cycloalkane ring and a cycloalkene ring. Specific examples of the cycloalkane ring include a cyclopentane ring, a cyclohexane ring, and the like. Specific examples of the cycloalkene ring include a cyclopentene ring, a cyclohexene ring, a 1,3-cyclohexadiene ring, a 1,4-cyclohexadiene ring, and the like.

[0033] As used herein, the "heterocycle" includes, in addition to the "heteroaryl ring" described later, a non-aromatic heterocycle. Examples of the non-aromatic heterocycle include a piperidine ring, a piperazine ring, a morpholine ring, and the like.

[0034] As used herein, the "aryl ring" (for example, the "aryl ring" in ring A, ring B, or ring C of formula (1)) is, for example, an aryl ring having 6 to 30 carbon atoms, preferably an aryl ring having 6 to 16 carbon atoms, more preferably an aryl ring having 6 to 12 carbon atoms, and particularly preferably an aryl ring having 6 to 10 carbon atoms.

[0035] Specific examples of the "aryl ring" include a benzene ring which is a monocyclic system, a biphenyl ring which is a bicyclic system, a naphthalene ring and an indene ring which are fused bicyclic systems, a terphenyl ring which is a tricyclic system (m-terphenyl, o-terphenyl, p-terphenyl), an acenaphthylene ring, a fluorene ring, a phenalene ring, a phenanthrene ring and an anthracene ring which are fused tricyclic systems, a triphenylene ring, a pyrene ring, a naphthacene ring and a chrysene ring which are fused tetracyclic systems, and a perylene ring and a pentacene ring which are fused pentacyclic systems. In addition, the fluorene ring, benzofluorene ring, and indene ring also include structures in which a fluorene ring, a benzofluorene ring, a cyclopentane ring, or the like is spiro-bonded thereto. Furthermore, the fluorene ring, benzofluorene ring, and indene ring also include those in which two of the two hydrogen atoms of the methylene group in the structure are each substituted with an alkyl such as methyl as the first substituent described below to form a dimethylfluorene ring, a dimethylbenzofluorene ring, a dimethylindene ring, or the like.

[0036] In this specification, "heteroaryl rings" (for example, "heteroaryl rings" in ring A, ring B, or ring C of formula (1)) include, for example, heteroaryl rings having 2 to 30 carbon atoms, with heteroaryl rings having 2 to 25 carbon atoms being preferred, heteroaryl rings having 2 to 20 carbon atoms being more preferred, heteroaryl rings having 2 to 15 carbon atoms being even more preferred, and heteroaryl rings having 2 to 10 carbon atoms being particularly preferred. In addition, examples of "heteroaryl rings" include heterocycles containing, for example, 1 to 5 heteroatoms selected from oxygen, sulfur, and nitrogen as ring constituent atoms in addition to carbon.

[0037] Specific examples of "heteroaryl rings" include, for example, pyrrole rings, oxazole rings, isoxazole rings, thiazole rings, isothiazole rings, imidazole rings, oxadiazole rings (such as furazan rings), thiadiazole rings, triazole rings, tetrazole rings, pyrazole rings, pyridine rings, pyrimidine rings, pyridazine rings, pyrazine rings, triazine rings, indole rings, isoindole rings, 1H-indazole rings, benzimidazole rings, benzoxazole rings, benzothiazole rings, 1H-benzotriazole rings, quinoline rings, isoquinoline rings, sinnoline rings, quinazoline rings, quinoxaline rings, phthalazine rings, naphthyridine rings, purine rings, pteridine rings, carbazole rings, acridine rings, phenoxatiin rings, phenoxazine rings, phenothiazine rings, phenazine rings, phenazacillin rings, indidine rings, furan rings, benzofuran rings, isobenzofuran rings, dibenzofuran rings, and thiophene rings. , benzothiophene ring, dibenzothiophene ring, thianthrene ring, indolocarbazole ring, benzoindocarbazole ring, dibenzoindocarbazole ring, naphthobenzofuran ring, dioxin ring, dihydroacridine ring, xanthene ring, thioxanthene ring, dibenzodioxin ring, dioxabora-naphthoanthracene ring (5,9-dioxa-13b-bora-13bH-naphtho[3,2,1-de]anthracene ring, etc.), benzoseleno Examples include phene rings, dibenzoselenophene rings, azacarbazole rings, azadibenzothiophene rings, azadibenzofuran rings, azadibenzoselenophene rings, azatriphenylene rings, imidazoimidazole rings, indoloindole rings, benzoflocarbazole rings, benzothienocarbazole rings, indenocarbazole rings, selenophenocarbazole rings, spiro[fluorene-9,9'-xanthene] rings, and spirobi[silafluorene] rings. In addition, dihydroacridine rings, xanthene rings, and thioxanthene rings are also preferred in which two of the two hydrogen atoms of the methylene group in their structure are replaced by alkyl groups such as methyl as the first substituent described later, resulting in dimethyldihydroacridine rings, dimethylxanthene rings, and dimethylthioxanthene rings.Bicyclic bipyridine rings, phenylpyridine rings, pyridylphenyl rings, and tricyclic terpyridyl rings, bispyridylphenyl rings, and pyridylbiphenyl rings are also mentioned as "heteroaryl rings". A pyran ring is also intended to be included in a "heteroaryl ring".

[0038] In this specification, a substituent may be substituted with a further substituent. For example, a specific substituent may sometimes be described as "substituted or unsubstituted". This means that the specific substituent is either substituted with at least one further substituent, or unsubstituted. The phrase "optionally substituted" is also used with the same meaning. In this specification, the aforementioned specific substituent in this case may be referred to as a "first substituent", and the aforementioned further substituent may be referred to as a "second substituent".

[0039] In this specification, substituent group Z is aryl optionally substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl and cycloalkyl, heteroaryl optionally substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl and cycloalkyl, diarylamino optionally substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl and cycloalkyl (the two aryl groups may be bonded to each other via a linking group), diheteroarylamino optionally substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl and cycloalkyl (the two heteroaryl groups may be bonded to each other via a linking group), arylheteroarylamino optionally substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl and cycloalkyl (the aryl and heteroaryl may be bonded to each other via a linking group), Diarylboryl (the two aryl groups may be linked by a single bond or a linking group) which may be substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl, and cycloalkyl groups. Alkyls which may be substituted with at least one group selected from the group consisting of aryl, heteroaryl, and cycloalkyl groups, A cycloalkyl group which may be substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl, and cycloalkyl groups. An alkoxy which may be substituted with at least one group selected from the group consisting of aryl, heteroaryl, and cycloalkyl groups. Aryloxys which may be substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl and cycloalkyl, and It consists of substituted silyls. The aryl secondary substituent in each group of substituent group Z may be further substituted with an aryl, heteroaryl, alkyl, or cycloalkyl group. Similarly, the heteroaryl secondary substituent may be substituted with an aryl, heteroaryl, alkyl, or cycloalkyl group.

[0040] In this specification, when the term "substituent" is used, unless otherwise specified, it may refer to any group selected from substituent group Z. For example, when a group described as "substituted or unsubstituted" is substituted, it is sufficient that the group is substituted with at least one group selected from substituent group Z.

[0041] In this specification, "aryl" means, for example, an aryl having 6 to 30 carbon atoms, preferably an aryl having 6 to 20 carbon atoms, an aryl having 6 to 16 carbon atoms, an aryl having 6 to 12 carbon atoms, or an aryl having 6 to 10 carbon atoms.

[0042] A specific example of "aryl" is the monovalent group obtained by removing one hydrogen atom from the aforementioned "aryl ring." For example, monocyclic phenyl, bicyclic biphenylyl (2-biphenylyl, 3-biphenylyl, or 4-biphenylyl), condensed bicyclic naphthyl (1-naphthyl or 2-naphthyl), tricyclic 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), and condensed tricyclic acenaphthylene-(1-, 3-, 4-, or 5 -)yl, fluoren-(1-,2-,3-,4-, or 9-)yl, phenalen-(1- or 2-)yl, phenanthren-(1-,2-,3-,4-, or 9-)yl, or anthracene-(1-,2-, or 9-)yl, or the tetracyclic quaterphenylyl(5'-phenyl-m-terphenyl-2-yl, 5'-phenyl-m-terphenyl-3-yl, 5'-phenyl Examples include m-terphenyl-4-yl (or m-quaterphenyl), condensed tetracyclic groups such as triphenylene-(1- or 2-)yl, pyren-(1-, 2-, or 4-)yl, or naphthacene-(1-, 2-, or 5-)yl, or condensed pentacyclic groups such as perylene-(1-, 2-, or 3-)yl, or pentacene-(1-, 2-, 5-, or 6-)yl. Other examples include the monovalent group of spirofluorene.

[0043] Furthermore, the aryl as the second substituent also includes structures in which the aryl is substituted with at least one group selected from the group consisting of aryl groups such as phenyl (specific examples are the groups mentioned above), alkyl groups such as methyl (specific examples are the groups described later), and cycloalkyl groups such as cyclohexyl or adamantyl (specific examples are the groups described later). One example is a group in which the 9th position of fluorenyl, as the second substituent, is substituted with an aryl group such as phenyl, an alkyl group such as methyl, or a cycloalkyl group such as cyclohexyl or adamantyl.

[0044] "Arylene" refers to, for example, arylene having 6 to 30 carbon atoms, preferably arylene having 6 to 20 carbon atoms, arylene having 6 to 16 carbon atoms, arylene having 6 to 12 carbon atoms, or arylene having 6 to 10 carbon atoms. A specific example of "arylene" is a divalent group obtained by removing one hydrogen atom from the aforementioned "aryl" (monovalent group).

[0045] "Heteroaryl" refers to, for example, a heteroaryl having 2 to 30 carbon atoms, 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. "Heteroaryl" contains one or more heteroatoms, preferably 1 to 5, selected from oxygen, sulfur, nitrogen, etc., in addition to carbon as ring constituent atoms.

[0046] Specific examples of "heteroaryls" include monovalent groups obtained by removing one hydrogen atom from the "heteroaryl ring" mentioned above. For example, pyrrolyl, oxazolyl, isoxazolyl, thiazolyl, isothiazolyl, imidazolyl, oxadiazolyl, thiadiazolyl, triazolyl, tetrazolyl, pyrazolyl, pyridyl, pyrimidinyl, pyridadinyl, pyrazinyl, triazinyl, indolyl, isoindolyl, 1H-indazolyl, benzimidazolyl, benzoxazolyl, benzothiazolyl, 1H-benzotriazolyl, quinolinyl, isoquinolinyl, sinnolinyl, quinazolinyl, quinoxalinyl, phenanthrolinyl, phthalazinyl, naphthilidinyl, prinyl, pteridinyl, carbazolyl, These include acridinyl, phenoxathiinyl, phenoxazinyl, phenothiazinyl, phenazacylinyl, phenazacylinyl, indolidinyl, furanil, benzofuranil, isobenzofuranil, dibenzofuranil, naphthobenzofuranil, thienyl, benzothienyl, isobenzothienyl, dibenzothienyl, naphthobenzothienyl, monovalent group of the benzophospholeoxide ring, monovalent group of the dibenzophospholeoxide ring, flazanil, thianthrenil, indolocarbazolyl, benzoindolocabazolyl, dibenzoindolocabazolyl, imidazolinil, or oxazolinil. Other examples include the monovalent group of spiro[fluorene-9,9'-xanthene], the monovalent group of spirovi[silafluorene], and the monovalent group of benzocerefen.

[0047] Furthermore, the heteroaryl as the second substituent also includes structures in which the heteroaryl is substituted with at least one group selected from the group consisting of aryl groups such as phenyl (specific examples are the groups mentioned above), alkyl groups such as methyl (specific examples are the groups described later), and cycloalkyl groups such as cyclohexyl or adamantyl (specific examples are the groups described later). One example is a group in which the 9th position of 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, groups in which nitrogen-containing heteroaryls such as pyridyl, pyrimidinyl, triazinyl, and carbazolyl are further substituted with phenyl or biphenylyl are also included in heteroaryls as the second substituent.

[0048] "Heteroarylene" refers to, for example, heteroarylenes having 2 to 30 carbon atoms, preferably heteroarylenes having 2 to 25 carbon atoms, 2 to 20 carbon atoms, 2 to 15 carbon atoms, or 2 to 10 carbon atoms. Furthermore, "heteroarylene" refers to a divalent group such as a heterocycle containing, for example, 1 to 5 heteroatoms selected from oxygen, sulfur, and nitrogen in addition to carbon as ring constituent atoms. A specific example of a "heteroarylene" is a divalent group obtained by removing one hydrogen atom from the aforementioned "heteroaryl" (a monovalent group).

[0049] A "diarylamino" is an amino acid in which two aryl groups are substituted. For details about these aryl groups, please refer to the explanation of "aryl" mentioned above. A "diheteroarylamino" is an amino group substituted with two heteroaryl groups. For details on these heteroaryl groups, please refer to the explanation of "heteroaryl" mentioned above. "Arylheteroarylamino" refers to an amino group substituted with aryl and heteroaryl groups. For details on these aryl and heteroaryl groups, please refer to the explanations of "aryl" and "heteroaryl" mentioned above.

[0050] The two aryl groups in the diarylamino as the first substituent may be bonded to each other via a linking group, the two heteroaryl groups 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 description "bonded via a linking group" means that, for example, two phenyl groups in diphenylamino form a bond via a linking group as shown below. This description also applies to diheteroarylamino and arylheteroarylamino formed of aryl and heteroaryl.

[0051]

Chemical Formula

[0052] Specific examples of the linking group include >O, >N-R X , >C(-R X )2, -(C-R X )=(C-R X )-, >Si(-R X )2, >S, >CO, >CS, >SO, >SO2, and >Se. Each R X is independently alkyl, cycloalkyl, aryl, or heteroaryl, and these may be substituted with alkyl, cycloalkyl, aryl, or heteroaryl. Further, in >C(-R X )2, -(C-R X )=(C-R X )-, >Si(-R X )2, the two R groups in each moiety X may be bonded to each other via a single bond or a linking group X Y to form a ring. Examples of X Y include >O, >N-R Y , >C(-R Y )2, >Si(-R Y )2, >S, >CO, >CS, >SO, >SO2, and >Se, and R YEach of these is independently an alkyl, cycloalkyl, aryl, or heteroaryl, and these may be substituted with alkyl, cycloalkyl, aryl, or heteroaryl. However, X Y >C(-R Y )2 and >Si(-R Y )In the case of 2, two R Y They do not bond to form further rings. Furthermore, alkenylenes can also be given as linking groups. Any hydrogen atom of the alkenylene can independently form R 2X It may also be replaced with R 2X Each of these is independently an alkyl, cycloalkyl, substituted silyl, aryl, and heteroaryl, which may be substituted with alkyl, cycloalkyl, substituted silyl, or aryl. -(CR X )=(CR X )- Two R X These may bond to each other and, together with the C=C to which they bond, form an aryl (such as a benzene ring) or heteroaryl ring. That is, -(CR X )=(CR X )- may be an allerene (such as 1,2-phenylene) or a heteroarylene.

[0053] In this specification, when "diarylamino," "diheteroarylamino," or "arylheteroarylamino" is simply referred to, unless otherwise specified, it is assumed that the following explanations are added: "The two aryls of diarylamino may be linked to each other via a linking group," "The two heteroaryls of the diheteroarylamino may be linked to each other via a linking group," and "The aryl and heteroaryls of the arylheteroarylamino may be linked to each other via a linking group."

[0054] A "diarylboryl" is a boryl substituted with two aryls, and details of these aryls can be found in the description of "aryl" above. These two aryls may also be linked by a single bond or a linking group (e.g., -CH=CH-, -CR=CR-, -C≡C-, >NR, >O, >S, >C(-R)2, >Si(-R)2, or >Se). Here, the R in -CR=CR-, >NR, >C(-R)2, and >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. Furthermore, two adjacent Rs may form a ring, forming cycloalkylene, arylene, and heteroarylene. For details of the substituents listed here, refer to the above-mentioned explanations of "aryl," "arylene," "heteroaryl," "heteroarylene," and "diarylamino," as well as the later-described explanations of "alkyl," "alkenyl," "alkynyl," "cycloalkyl," "cycloalkylene," "alkoxy," and "aryloxy." Furthermore, wherever "diarylboryl" is mentioned in this specification, unless otherwise specified, it is assumed that the explanation "the two aryls of diarylboryl may be linked to each other by a single bond or by a linking group" is included.

[0055] "Alkyl" can be either a linear or branched alkyl group, for example, a linear alkyl group having 1 to 24 carbon atoms or a branched alkyl group having 3 to 24 carbon atoms. Preferably, it is an alkyl group having 1 to 18 carbon atoms (branched alkyl group having 3 to 18 carbon atoms), an alkyl group having 1 to 12 carbon atoms (branched alkyl group having 3 to 12 carbon atoms), an alkyl group having 1 to 6 carbon atoms (branched alkyl group having 3 to 6 carbon atoms), an alkyl group having 1 to 5 carbon atoms (branched alkyl group having 3 to 5 carbon atoms), an alkyl group having 1 to 4 carbon atoms (branched alkyl group having 3 to 4 carbon atoms), and so on.

[0056] 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-di Examples 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, or n-eicosyl.

[0057] "Alkylene" is a divalent group obtained by removing one of the hydrogen atoms of an "alkyl" group, such as methylene, ethylene, and propylene.

[0058] Regarding "alkenyl," you can refer to the explanation of "alkyl" above. It is a group in which a single C=C bond in the structure of "alkyl" is replaced with a C=C double bond, and it includes not just one but two or more single bonds that are replaced with double bonds (also called alkadiene-yl or alkatriene-yl).

[0059] "Alkenylene" is a divalent group obtained by removing one of the hydrogen atoms from "alkenyl," and vinylene is an example of this.

[0060] Regarding "alkynyl," you can refer to the explanation of "alkyl" above. It is a group in which a single C≡C bond in the structure of "alkyl" is replaced with a triple C≡C bond, and it includes not just one but two or more single bonds that are replaced with triple bonds (also called alkadiyne-yl or alkatriyne-yl).

[0061] "Cycloalkyl" refers to, for example, a cycloalkyl group having 3 to 24 carbon atoms, preferably a cycloalkyl group having 3 to 20 carbon atoms, 3 to 16 carbon atoms, 3 to 14 carbon atoms, 3 to 12 carbon atoms, 5 to 10 carbon atoms, 5 to 8 carbon atoms, 5 to 6 carbon atoms, or a cycloalkyl group having 5 carbon atoms.

[0062] Specific examples of "cycloalkyl" include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl, or alkyl (especially methyl) substituted derivatives of these with 1-5 or 1-4 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, or decahydroazlenyl.

[0063] "Cycloalkylene" refers to, for example, a cycloalkylene having 3 to 24 carbon atoms, preferably a cycloalkylene having 3 to 20 carbon atoms, a cycloalkylene having 3 to 16 carbon atoms, a cycloalkylene having 3 to 14 carbon atoms, a cycloalkylene having 3 to 12 carbon atoms, a cycloalkylene having 5 to 10 carbon atoms, a cycloalkylene having 5 to 8 carbon atoms, a cycloalkylene having 5 to 6 carbon atoms, or a cycloalkylene having 5 carbon atoms. A specific example of a "cycloalkylene" is a divalent group obtained by removing one hydrogen atom from the aforementioned "cycloalkyl" (a monovalent group).

[0064] "Alkoxy" is a group represented as "Alk-O- (where Alk is alkyl)," and for details about this alkyl group, please refer to the explanation of "alkyl" mentioned above.

[0065] "Aryloxy" is a group represented as "Ar-O-" (where Ar is aryl), and for details about this aryl group, please refer to the explanation of "aryl" mentioned above.

[0066] A "substituted silyl" is, for example, a silyl substituted with at least one of aryl, alkyl, and cycloalkyl groups, preferably a triarylsilyl, trialkylsilyl, tricycloalkylsilyl, dialkylcycloalkylsilyl, or alkyldicycloalkylsilyl.

[0067] A "triarylsilyl" is a silyl group substituted with three aryl groups. For details about these aryl groups, please refer to the explanation of "aryl" mentioned above. Specific examples of "triarylsilyls" include triphenylsilyl, diphenylmononaphthylsilyl, monophenyldinaphthylsilyl, or trinaphthylsilyl.

[0068] "Trialkylsilyl" refers to a silyl group substituted with three alkyl groups. For details about these alkyl groups, please refer to the explanation of "alkyl" mentioned above. Specific examples of "trialkylsilyls" 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, or t-butyldiisopropylsilyl.

[0069] "Tricycloalkylsilyl" is a silyl group substituted with three cycloalkyl groups. For details on these cycloalkyl groups, please refer to the explanation of "cycloalkyl" mentioned above. Specific examples of "tricycloalkylsilyls" include tricyclopentylsilyl or tricyclohexylsilyl.

[0070] A "dialkylcycloalkylsilyl" is a silyl group substituted with two alkyl groups and one cycloalkyl group. For details on these alkyl and cycloalkyl groups, please refer to the explanations of "alkyl" and "cycloalkyl" above.

[0071] "Alkyldicycloalkylsilyl" refers to a silyl group substituted with one alkyl and two cycloalkyl groups. For details on these alkyl and cycloalkyl groups, please refer to the explanations of "alkyl" and "cycloalkyl" above.

[0072] <When two groups bonded to the same atom bond to each other> In this specification, when 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 referred to as a bonding group). Examples of linking groups include -CH2-CH2-, -CHR-CHR-, -CR2-CR2-, -CH=CH-, -CR=CR-, -C≡C-, -N(-R)-, -O-, -S-, -C(-R)2-, -Si(-R)2-, or -Se-, and the following structure is an example. Furthermore, the R in -CHR-CHR-, -CR2-CR2-, -CR=CR-, -N(-R)-, -C(-R)2-, and -Si(-R)2- are each independently hydrogen, an aryl which may be substituted with alkyl or cycloalkyl, a heteroaryl which may be substituted with alkyl or cycloalkyl, an alkyl which may be substituted with cycloalkyl, an alkenyl which may be substituted with alkyl or cycloalkyl, an alkynyl which may be substituted with alkyl or cycloalkyl, or a cycloalkyl which may be substituted with alkyl or cycloalkyl. In addition, two adjacent Rs may form a ring, forming a cycloalkylene, an arylene, and a heteroarylene.

[0073] [ka]

[0074] Preferred bonding groups are single bonds and linking groups -CR=CR-, -N(-R)-, -O-, -S-, -C(-R)2-, -Si(-R)2-, and -Se-; more preferred are single bonds and linking groups -CR=CR-, -N(-R)-, -O-, -S-, and -C(-R)2-; even more preferred are single bonds and linking groups -CR=CR-, -N(-R)-, -O-, and -S-; and single bonds are most preferred.

[0075] The positions where the two R groups bond via the bonding group are not particularly limited as long as they are bondable positions, but it is preferable that they bond at the most adjacent positions. For example, if the two groups are phenyl groups, it is preferable that they bond at the ortho (position 2) relative to the bond position (position 1) of the "C" or "Si" in phenyl (see the structural formula above).

[0076] 1. Polycyclic aromatic compounds <Description of the overall structure of the compound> The polycyclic aromatic compound of the present invention is a polycyclic aromatic compound having a structure that includes a structural unit represented by formula (1). [ka]

[0077] In formula (1), Rings A and B are independently substituted or unsubstituted aryl rings or substituted or unsubstituted heteroaryl rings. The C ring is a substituted or unsubstituted hydrocarbon ring or a substituted or unsubstituted heteroring, and the dashed line represents a divalent group connecting two nitrogen atoms.

[0078] The polycyclic aromatic compounds of the present invention have a skeleton similar to the boron-containing polycyclic aromatic compounds described in International Publication No. 2015 / 102118. Polycyclic aromatic compounds, such as those described in International Publication No. 2015 / 102118, in which aromatic rings are linked by heteroatoms such as boron, nitrogen, oxygen, and sulfur, have been found to have a large HOMO-LUMO gap (band gap Eg in thin films). This is because the six-membered ring containing the heteroatom has low aromaticity, suppressing the decrease in the HOMO-LUMO gap associated with the expansion of the conjugated system. Furthermore, it has been found that the HOMO-LUMO gap of the above polycyclic aromatic compounds can be arbitrarily changed depending on the type of heteroatom and the linking method. This is thought to be because the HOMO and LUMO energies can be arbitrarily manipulated depending on the spatial extent and energy of the empty orbitals or lone pairs of the heteroatoms.

[0079] These polycyclic aromatic compounds exhibit a narrow full width at half maximum of the fluorescence emission peak due to the localization of excited SOMO1 and SOMO2 states on each atom through electronic perturbation of heteroatoms. This results in high color purity emission when used as dopants in organic light-emitting diodes (OLEDs). For similar reasons, ΔE S1T1 The reduced size allows it to exhibit thermally activated delayed fluorescence, resulting in high efficiency when used as an emitting dopant for organic EL devices.

[0080] In compounds having the structure represented by formula (1), a nitrogen-containing five-membered ring is further introduced to the above skeleton, and boron (B) is bonded to the 3-position of this ring. This structure allows electron donation from N to B in the nitrogen-containing five-membered ring, stabilizing the CB bond. Furthermore, electron donation to boron makes the LUMO localized on the aromatic ring in the structure shallower, widening the gap (Eg) and shortening the wavelength. In addition, the multiple resonance effect between boron (electron-withdrawing) and nitrogen (electron-donating) is enhanced, sharpening the spectrum and ΔE. S1T1 A reduction occurs.

[0081] The polycyclic aromatic compound of the present invention has a fused ring structure in which more rings are fused in the dotted region, making the molecule more rigid and improving the emission quantum yield. This structure reduces the number of easily broken bonds, making the molecule more stable and extending the operating lifetime when used as a device. It also achieves a high lowest excitation triplet energy level (E T1 By maintaining a large fused ring system, the carrier mobility is increased, resulting in good properties when used as a hole transport layer material, etc.

[0082] In formula (1), the divalent group connecting the two nitrogen atoms can be a substituted or unsubstituted arylene, a substituted or unsubstituted heteroarylene, a substituted or unsubstituted alkylene, a substituted or unsubstituted alkenylene, and the like. In particular, the group represented by the following formula is preferred.

[0083] [ka] In other words, the structural unit represented by formula (1) is preferably represented by formula (1D).

[0084] [ka]

[0085] The D ring is a substituted or unsubstituted hydrocarbon ring or a substituted or unsubstituted heteroring, and the two asterisks indicate the bond positions with two nitrogen atoms. The D ring may be further bonded to the A ring and / or C ring by a linking group or a single bond. The D ring is preferably a substituted or unsubstituted benzene ring or a substituted or unsubstituted cyclohexane ring. Specifically, the dashed portion is substituted or unsubstituted 1,2-phenylene or substituted or unsubstituted 1,2-cyclohexylene. The D ring may also be linked to the A ring and / or C ring by a linking group or a single bond, in which case the linking group is 1,2-phenylene.

[0086] Ring A forms a trivalent group having bonds to three consecutive elements (preferably carbon) on the aryl or heteroaryl ring in its structure. Each of these three bonds forms an X 1 , binds to N and B. The aryl or heteroaryl ring in ring A is B, X 1 It is preferable that it is bonded to N by a 5-membered or 6-membered ring. The B ring forms a divalent group having bonds to two consecutive elements (preferably carbon) on the aryl or heteroaryl ring in its structure. With each of these two bonds, X 1 and binds to B. The aryl ring or heteroaryl ring in the B ring is B and X 1 It is preferable that the rings are bonded by a five-membered or six-membered ring. "Bound by a five-membered or six-membered ring" means that the ring is formed by this five-membered or six-membered ring alone, or that other rings are fused to include this five-membered or six-membered ring to form a ring. In other words, the five-membered or six-membered rings that make up all or part of the ring are B, X 1and N, or B and X 1 This means that it is bonded to B, X. In aryl or heteroaryl rings in rings A and B, two or three consecutive ring constituent atoms (carbon atoms) are B, X 1 and N, or B and X 1 It is sufficient for them to be directly bonded. The C ring forms a divalent group having bonding bonds to two consecutive elements (preferably carbon) on the hydrocarbon ring or heterocycle in its structure. These two bonds bond to N and C (carbon), respectively. The D ring forms a divalent group having bonding bonds to two consecutive elements (preferably carbon) on the hydrocarbon ring or heterocycle in its structure. These two bonds bond to two N atoms. Similarly, the hydrocarbon rings or heterocycles in the C and D rings are preferably 5-membered or 6-membered rings, bonded to a carbon atom and a nitrogen atom, and to two nitrogen atoms, respectively.

[0087] In rings A, B, C, and D, the "hydrocarbon ring," "heterocycle ring," "aryl ring," or "heteroaryl ring" may be substituted with at least one substituent selected from the substituent group Z described below. Also, in rings A and B, the "aryl ring" or "heteroaryl ring" may be substituted with X as described below. 1 It may also be combined with this.

[0088] <Structure including structural units represented by formula (1)> The polycyclic aromatic compounds of the present invention are polycyclic aromatic compounds having a structure containing a structural unit represented by formula (1). Polycyclic aromatic compounds having a structure containing a structural unit represented by formula (1) include polycyclic aromatic compounds having a structure consisting of one or more structural units represented by formula (1). Examples of polycyclic aromatic compounds having a structure consisting of one of the above structural units include polycyclic aromatic compounds represented by the formula described above as the structural unit represented by formula (1). Examples of polycyclic aromatic compounds having a structure consisting of two or more structural units represented by formula (1) include compounds corresponding to the polymer of the compound represented by the formula described above as the structural unit represented by formula (1). The polymer is preferably a 2-6 mer, more preferably a 2-3 mer, and particularly preferably a dimer. A polymer can be any form in which a single compound has multiple of the above-mentioned unit structures, and may be a form in which any ring (A ring, B ring, or C ring) contained in the above-mentioned structural unit is shared among multiple unit structures, or may be a form in which any ring (A ring, B ring, or C ring) contained in the above-mentioned unit structures is fused together. Alternatively, the above-mentioned unit structures may be in a form in which multiple units are linked by single bonds or by linking groups such as alkylene, phenylene, or naphthylene having 1 to 3 carbon atoms. Of these, the form in which rings are shared is preferred.

[0089] <Equations (1M), (1-a), (1-b), (1-c), (1-d), (1-f), (1-g), (1-h), and (1-i)> Polycyclic aromatic compounds having a structure containing the structural unit represented by formula (1) further include compounds represented by the following formula (1M).

[0090] [ka]

[0091] In formula (1M), rings A and A' are synonymous with ring A in formula (1), and their preferred ranges are the same. Rings B and B' are synonymous with ring B in formula (1), and their preferred ranges are the same, except that ring B forms a tetravalent group having bonds to two sets of consecutive elements (preferably carbon) on the aryl or heteroaryl ring in its structure. In formula (1M), X 1 X is the X in equation (1). 1 It is synonymous with the same thing, and the preferred range is also the same.

[0092] Preferred examples of polycyclic aromatic compounds having a structure containing a structural unit represented by formula (1) include compounds represented by any of the following formulas selected from the group consisting of formulas (1-a), (1-b), (1-c), (1-d), (1-f), (1-g), (1-h), and (1-i). [ka]

[0093] In equations (1-a), (1-b), (1-c), (1-d), (1-f), (1-g), (1-h), and (1-i), Each Z is independent of N or CR. Z And R Z Each of these is independently a hydrogen atom or a substituent selected from substituent group Z. Two adjacent R Z These elements may bond to each other to form an aryl ring or a heteroaryl ring, and the formed aryl ring or heteroaryl ring may each be substituted with any substituent selected from substituent group Z. Each of Z=Z may independently be >O, >NR, >C(-R)2, >Si(-R)2, >S, or >Se, and each of the R in >NR, >C(-R)2, and >Si(-R)2 may independently be hydrogen, a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted alkyl, or a substituted or unsubstituted cycloalkyl, and the two Rs in >C(-R)2 and >Si(-R)2 may be bonded to each other to form a ring.

[0094] In equations (1-a), (1-b), (1-c), (1-d), (1-f), (1-g), (1-h) and (1-i), Z is always CR. Z It is preferable that this be the case. R Z Preferably, any substituent selected from the substituent group Z is alkyl, optionally alkyl-substituted phenyl, optionally alkyl-substituted diphenylamino, or optionally alkyl-substituted carbazolyl.

[0095] <Preferred substructure> A polycyclic aromatic compound having a structure containing a structural unit represented by formula (1), particularly a polycyclic aromatic compound represented by any formula selected from the group consisting of formulas (1-a), (1-b), (1-c), and (1-d), preferably contains at least one substructure represented by any formula selected from the group consisting of formulas (B101), (B102), (B103), (B104), (B105), (B106), (B107), and (B108).

[0096] [ka]

[0097] In formulas (B101), (B102), (B103), (B104), (B105), (B106), (B107), and (B108), Z is synonymous with Z in equations (1-a), (1-b), (1-c), and (1-d), and their preferred ranges are also the same. None of the Z=Zs are >O, and two adjacent Rs Z It is preferable that they are not bonded to each other. X 5 is >O, >NR, >C(-R)2, >S, or >Se, where R in >NR is hydrogen, a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted alkyl, or a substituted or unsubstituted cycloalkyl, where R in >C(-R)2 is independently hydrogen, a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted alkyl, or a substituted or unsubstituted cycloalkyl, and the two Rs in >C(-R)2 may be bonded to each other to form a ring. 5 It is preferable that the molecule is a >C(-R)2 where >O, >C(-CH3)2, or R are all phenyl molecules, and the two phenyl molecules are bonded to each other. n is an integer between 1 and 3, preferably 1 or 2, and more preferably 2.

[0098] <Preferred substituents> When a polycyclic aromatic compound having a structure containing the structural unit represented by formula (1) is used as a dopant (assisting dopant or emitting dopant), in other compounds used as dopants, the tertiary alkyl represented by the following formula (tR) is one of the particularly preferred substituents containing "alkyl" as a substituent to the aryl or heteroaryl rings in the A, B, C, and D rings. This is because such bulky substituents increase the intermolecular distance, thereby improving the luminescence quantum yield (PLQY). Furthermore, substituents in which the tertiary alkyl represented by formula (tR) is substituted with another substituent as a second substituent are also preferred. Specifically, examples include diarylamino substituted with the tertiary alkyl represented by (tR), carbazolyl (preferably N-carbazol) substituted with the tertiary alkyl represented by (tR), or benzocarbazol (preferably N-benzocarbazol) substituted with the tertiary alkyl represented by (tR). Examples of substitutions of the (tR) group on diarylamino, carbazolyl, and benzocarbazolyl groups include cases where some or all of the hydrogen atoms in the aryl or benzene ring of these groups are replaced by the (tR) group.

[0099] [ka]

[0100] In the formula (tR), R a , R b , and R c Each of these is an alkyl group having 1 to 24 carbon atoms, and any -CH2- in the alkyl group may be substituted with -O-, and the group represented by formula (tR) has * as its bonding position.

[0101] R a , R b and R cThe "alkyl group having 1 to 24 carbon atoms" can be either linear or branched. Examples include linear alkyl groups having 1 to 24 carbon atoms or branched alkyl groups having 3 to 24 carbon atoms, alkyl groups having 1 to 18 carbon atoms (branched alkyl groups having 3 to 18 carbon atoms), alkyl groups having 1 to 12 carbon atoms (branched alkyl groups having 3 to 12 carbon atoms), alkyl groups having 1 to 6 carbon atoms (branched alkyl groups having 3 to 6 carbon atoms), and alkyl groups having 1 to 4 carbon atoms (branched alkyl groups having 3 to 4 carbon atoms).

[0102] R in equation (tR) a , R b , and R c The total number of carbon atoms is preferably 3 to 20, and particularly preferably 3 to 10.

[0103] R a , R b , and R c Specific alkyl groups 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 include -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.

[0104] Examples of groups represented by formula (tR) include t-butyl, t-amyl, 1-ethyl-1-methylpropyl, 1,1-diethylpropyl, 1,1-dimethylbutyl, 1-ethyl-1-methylbutyl, 1,1,3,3-tetramethylbutyl, 1,1,4-trimethylpentyl, 1,1,2-trimethylpropyl, 1,1-dimethyloctyl, 1,1-dimethylpentyl, 1,1-dimethylheptyl, 1,1,5-trimethylhexyl, 1-ethyl- Examples include 1-methylhexyl, 1-ethyl-1,3-dimethylbutyl, 1,1,2,2-tetramethylpropyl, 1-butyl-1-methylpentyl, 1,1-diethylbutyl, 1-ethyl-1-methylpentyl, 1,1,3-trimethylbutyl, 1-propyl-1-methylpentyl, 1,1,2-trimethylpropyl, 1-ethyl-1,2,2-trimethylpropyl, 1-propyl-1-methylbutyl, and 1,1-dimethylhexyl. Of these, t-butyl and t-amyl are preferred.

[0105] The emission wavelength can be adjusted by the steric hindrance, electron-donating, and electron-withdrawing properties of the substituent structure of a compound used as a dopant (assisting dopant or emitting dopant) such as a polycyclic aromatic compound having a structure containing a structural unit represented by formula (1). Preferably, the group is represented by the following structural formula, and more preferably, methyl, t-butyl, t-amyl, t-octyl, neopentyl, adamantyl, phenyl, o-tolyl, p-tolyl, 2,4-xylyl, 2,5-xylyl, 2,6-xylyl, 2,4,6-mesityl, diphenylamino, di-p-tolylamino, bis(p-(t-butyl)phenyl)amino, carbazolyl, 3,6-dimethylcarbazolyl, 3,6- The compounds are di-t-butylcarbazol and phenoxy, and more preferably methyl, t-butyl, t-amyl, t-octyl, neopentyl, adamantyl, phenyl, o-tolyl, 2,6-xylyl, 2,4,6-mesityl, diphenylamino, di-p-tolylamino, bis(p-(t-butyl)phenyl)amino, carbazolyl, 3,6-dimethylcarbazolyl, and 3,6-di-t-butylcarbazolyl. From the viewpoint of ease of synthesis, greater steric hindrance is preferable 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.

[0106] In the structural formula below, * represents a bond position. [ka]

[0107] [ka]

[0108] [ka]

[0109]

change

[0110]

change

[0111]

change

[0112]

change

[0113]

change

[0114]

change

[0115]

change

[0116]

change

[0117]

change

[0118]

change

[0119] [ka]

[0120] Polycyclic aromatic compounds having a structure containing the structural unit represented by formula (1) preferably have a structure containing at least one tert-alkyl (such as t-butyl or t-amyl), neopentyl, or adamantyl represented by formula (tR) above, and preferably contain a tert-alkyl (such as t-butyl or t-amyl) represented by formula (tR). This is because such bulky substituents increase the intermolecular distance, thereby improving the luminescence quantum yield (PLQY). Diarylaminos are also preferred as substituents. Furthermore, diarylaminos substituted with the group of formula (tR), carbazolyls (preferably N-carbazol) substituted with the group of formula (tR), or benzocarbazols (preferably N-benzocarbazol) substituted with the group of formula (tR) are also preferred. Examples of substitutions of the (tR) group on diarylamino, carbazolyl, and benzocarbazolyl groups include cases where some or all of the hydrogen atoms in the aryl or benzene ring of these groups are substituted with the (tR) group.

[0121] In formula (1), the substituents of the aryl ring or heteroaryl ring in rings A, B, and C may be substituents represented by the following formula (A20). [ka]

[0122] The substituent represented by formula (A20) is bonded to two adjacent atoms on an aryl or heteroaryl ring by two *s, In formula (A20), L is >NR, >O, >Si(-R)2, or >S, where R in >NR is a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted alkyl, or a substituted or unsubstituted cycloalkyl, and R in >Si(-R)2 is hydrogen, an optionally substituted aryl, an optionally substituted alkyl, or an optionally substituted cycloalkyl, and they may be linked to each other by a linking group, and at least one of the R in >NR and >Si(-R)2 is linked to the A ring, B ring, or R by a linking group or single bond. XC and R A It may be combined with at least one selected from the group consisting of, r is an integer from 1 to 4, R A Each of these is independently hydrogen, a substituted or unsubstituted alkyl, or a substituted or unsubstituted cycloalkyl, and any R A is any other R A They may be bonded to each other by linking groups or single bonds.

[0123] Examples of the substituents mentioned above include substituents represented by any of the following: [ka]

[0124] In each formula, * indicates that the atom is bonded to two or three adjacent atoms on any of the aryl or heteroaryl rings in rings A, B, or C.

[0125] <X 1 Explanation > X in equation (1) 1>O, >NR, >C(-R)2, >Si(-R)2, >S, or >Se, where R in >NR is hydrogen, a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted alkyl, or a substituted or unsubstituted cycloalkyl, where R in >C(-R)2 and >Si(-R)2 are independently hydrogen, a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted alkyl, or a substituted or unsubstituted cycloalkyl, where the two Rs in >C(-R)2 and >Si(-R)2 may be bonded to each other to form a ring, and where R in >NR, >C(-R)2, and >Si(-R)2 may be bonded to the A and / or B rings by linking groups or single bonds. X in equation (1) 1 It is more preferable that it be >O or >NR, and more preferably >NR.

[0126] X 1 The R in >Si(-R)2 and >C(-R)2 are each independently hydrogen, a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted alkyl, or a substituted or unsubstituted cycloalkyl, and it is preferable that the two Rs are the same, and the two Rs may be bonded to each other to form a ring.

[0127] X 1In formula (tR), R is preferably a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, or a substituted or unsubstituted cycloalkyl, and more preferably a substituted or unsubstituted aryl or a substituted or unsubstituted heteroaryl. Here, preferred aryls are phenyl, biphenylyl (especially 2-biphenylyl), and terphenylyl (especially terphenyl-2'-yl), and preferred heteroaryls are benzothienyl (2-benzothienyl, 6-benzothienyl, etc.), benzofuranyl (2-benzofuranyl, 3-benzofuranyl, 5-benzofuranyl, etc.), dibenzofuranyl (4-dibenzofuranyl, etc.), dimethylxanthenyl (2-dimethylxanthenyl, etc.), dibenzodioxynyl, etc. Preferred substituents are tert-alkyl (especially t-butyl) or cycloalkyl (especially adamantyl) represented by the above formula (tR). The number of substituents in the aryl and heteroaryl is preferably 0 to 2, more preferably 1 or 2, and even more preferably 1. It is also preferable that the aryl ring in the above aryl is condensed with a substituted or unsubstituted cycloalkane, as described later. Specific examples of cycloalkanes can be found in the following sections.

[0128] X 1 In >NR, >Si(-R)2, and >C(-R)2, R may be linked to the A and / or B rings by a linking group or a single bond. The linking groups include -O-, -S-, and -C(-R F )2-, -Si(-R F )2-, -N=C(-R G )―, and―C(-R G )=C(-R G ) - is preferable. R F is hydrogen, alkyl, cycloalkyl, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, and "-C(-R F )2-", -Si(-R F )2-" each of the two R F They are preferably identical, and may be bonded to each other to form a ring. GR is a hydrogen atom or a substituent. G It is preferable that is hydrogen, alkyl, or phenyl which may be substituted with alkyl.

[0129] X 1 Examples of R bonding to the A and / or B rings include cases where R is phenyl > NR forms a carbazole ring, phenoxazine ring, or phenothiazine ring as a substructure together with a benzene ring in the A or B ring; cases where R is hydrogen (forming a bonding hand) > NR forms an indole ring or benzimidazole ring as a substructure together with a benzene ring in the A or B ring; and cases where R is hydrogen (forming a bonding hand) > NR forms an imidazoindole ring or triazoindole ring as a substructure together with an indole ring in the A or B ring.

[0130] As another example, a form in which R in >NR is a substituted or unsubstituted cycloalkyl and is bonded to the A or B ring by a single bond is also preferred. As the cycloalkyl, substituted or unsubstituted cyclopentyl or substituted or unsubstituted cyclohexyl are preferred.

[0131] As a particularly preferred example of the fused ring formed as described above, the structure represented by formula (A11) can be given. In formula (A11), * represents "X 1 In the aforementioned provision, "R in at least one of >NR, >Si(-R)2 and >C(-R)2 may be bonded to the A ring and / or B ring by a linking group or a single bond," this corresponds to the form where the bond is by a single bond. In this case, the two carbons substituted with methyl are chiral carbons, and while diastereomers and enantiomers may exist as the compound represented by formula (1), the compound represented by formula (1) may be any isomer thereof, or it may be in the form of a mixture of possible isomers in any ratio.

[0132] [ka]

[0133] In equation (A11), X is at the positions of * and **. 1 It is bonded to one of the two rings at the position of ***, and to the other ring.

[0134] Similarly, the following examples are given in which R in >NR is phenyl and is bonded to the A or B ring by a single bond. [ka] In equation (A12), X is used at the positions of * and **. 1 It is bonded to one of the two rings at the position of ***, and to the other ring.

[0135] The above preferred range of R is >NR to X 1 By using the compound of the present invention, which has the properties of the present invention, as a light-emitting material in the manufacture of the device, the light-emitting efficiency and device lifespan can be further improved.

[0136] In equations (1-a), (1-b), (1-c), (1-d), (1-f), (1-g), (1-h), and (1-i), X 2 Each of these is independently >O, >NR, >C(-R)2, >S, or >Se, where R in >NR is hydrogen, a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted alkyl, or a substituted or unsubstituted cycloalkyl, and each of the R in >C(-R)2 is independently hydrogen, a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted alkyl, or a substituted or unsubstituted cycloalkyl, and both >NR and >C(-R)2 may be bonded at R to one or more Z atoms bonded to the same carbon atom. 2 It is more preferable that >O or >NR, and more preferably >NR. The preferred range of R is X in equation (1). 1 This is similar to the preferred range of R in NR.

[0137] In equations (1-a), (1-b), (1-c), (1-d), (1-f), (1-g), (1-h), and (1-i), X 4 >O, >NR, >C(-R)2, >S, or >Se, where R in >NR is hydrogen, a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted alkyl, or a substituted or unsubstituted cycloalkyl, and each of the Rs in >C(-R)2 is independently hydrogen, a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted alkyl, or a substituted or unsubstituted cycloalkyl, and both >NR and >C(-R)2 may be bonded at R to one or more Zs bonded to the same carbon atom. 4 It is preferable that >O, >NR, or >S.

[0138] <Cycloalkane condensation> In polycyclic aromatic compounds having a structure containing the structural unit represented by formula (1), at least one selected from the group consisting of aryl rings and heteroaryl rings may be condensed with at least one cycloalkane. The same applies to polycyclic aromatic compounds having a structure containing the structural unit represented by any of the formulas selected from the group consisting of formulas (1-a), (1-b), (1-c), (1-d), (1-f), (1-g), (1-h), and (1-i), and the following explanation also applies to polycyclic aromatic compounds represented by any of these formulas.

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

[0140] The cycloalkane is preferably a cycloalkane having 3 to 20 carbon atoms, wherein at least one hydrogen atom in the cycloalkane may be substituted with an aryl group having 6 to 16 carbon atoms, a heteroaryl group having 2 to 22 carbon atoms, an alkyl group having 1 to 12 carbon atoms, or a cycloalkyl group having 3 to 16 carbon atoms.

[0141] Examples of "cycloalkanes" include cycloalkanes with 3 to 24 carbon atoms, cycloalkanes with 3 to 20 carbon atoms, cycloalkanes with 3 to 16 carbon atoms, cycloalkanes with 3 to 14 carbon atoms, cycloalkanes with 5 to 10 carbon atoms, cycloalkanes with 5 to 8 carbon atoms, cycloalkanes with 5 to 6 carbon atoms, and cycloalkanes with 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 (especially methyl), halogen (especially fluorine), and deuterium-substituted compounds of these compounds having 1 to 5 carbon atoms.

[0143] Among these, a structure in which at least one hydrogen atom is substituted at the α-position carbon of the cycloalkane (the carbon adjacent to the carbon at the condensation site in a cycloalkyl condensed to an aryl or heteroaryl ring), as shown in the structural formula below, is preferred; a structure in which two hydrogen atoms are substituted at the α-position carbon is more preferred; and a structure in which a total of four hydrogen atoms are substituted at two α-position carbons is even more preferred. Examples of substituents include alkyl groups (especially methyl), halogens (especially fluorine), and deuterium, having 1 to 5 carbon atoms. In particular, a structure in which a substructure represented by the following formula (B) is bonded to an adjacent carbon atom in an aryl or heteroaryl ring is preferred.

[0144] [ka] In equation (B), * indicates the bonding position.

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

[0146] [ka]

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

[0148] [ka]

[0149] At least one hydrogen atom in the cycloalkane may be substituted. Examples of such substituents include aryl, heteroaryl, diarylamino, diheteroarylamino, arylheteroarylamino, diarylboryl (the two aryls may be linked by a single bond or a linking group), alkyl, cycloalkyl, alkoxy, aryloxy, substituted silyl, deuterium, cyano, or halogen. Details of these substituents can be found in the description of the first substituent above. Among these substituents, alkyl (e.g., alkyls with 1 to 6 carbon atoms), cycloalkyl (e.g., cycloalkyls with 3 to 14 carbon atoms), halogen (e.g., fluorine), and deuterium are preferred. Furthermore, when cycloalkyl is substituted, the substitution may form a spiro structure, an example of which is shown below.

[0150] [ka]

[0151] One form of cycloalkane condensation is the condensation of aryl rings and heteroaryl rings in the A, B, and C (and D) rings of a polycyclic aromatic compound having a structure containing the structural unit represented by formula (1) with a cycloalkane.

[0152] Other forms of cycloalkane condensation include polycyclic aromatic compounds having a structure containing the structural unit represented by formula (1), such as >NR where R is an aryl condensed with a cycloalkane, diarylamino (condensed to this aryl moiety), carbazolyl (condensed to this benzene ring moiety) or benzocarbazolyl (condensed to this benzene ring moiety) with a cycloalkane.

[0153] Furthermore, by introducing a cycloalkane structure to the polycyclic aromatic compound of the present invention, a decrease in melting point and sublimation temperature can be expected. This means that in sublimation purification, which is almost indispensable as a purification method for organic devices such as organic EL elements that require high purity, purification can be performed at a relatively low temperature, thus avoiding thermal decomposition of the material. The same applies to the vacuum deposition process, which is a powerful means of fabricating organic devices such as organic EL elements, as the process can be carried out at a relatively low temperature, thus avoiding thermal decomposition of the material and resulting in the acquisition of high-performance organic devices. In addition, since the solubility in organic solvents is improved by introducing a cycloalkane structure, it can also be applied to the fabrication of elements using coating processes. However, the present invention is not particularly limited to these principles.

[0154] <Replacement with deuterium, cyanopropyl alcohol, or halogen> The hydrogen atoms in a structure containing the structural unit represented by formula (1) may be all or part deuterium, cyano, or halogen. The same applies to polycyclic aromatic compounds having a structure containing a structural unit selected from the group consisting of formulas (1-a), (1-b), (1-c), (1-d), (1-f), (1-g), (1-h), and (1-i), and the following explanation also applies to polycyclic aromatic compounds represented by any formula selected from the group consisting of formulas (1-a), (1-b), (1-c), (1-d), (1-f), (1-g), (1-h), and (1-i).

[0155] For example, in a structure containing a structural unit represented by formula (1), the A ring, B ring, C ring (A to C rings are aryl rings or heteroaryl rings), D ring (D ring is an aryl ring or heteroaryl ring), substituents on the A to C rings, and X 1 When R is >NR, >C(-R)2, or >Si(-R)2, the hydrogen in R (=alkyl, cycloalkyl, aryl, or heteroaryl) can be replaced with deuterium, cyano, or halogen, among which embodiments include those in which all or some of the hydrogen in the aryl or heteroaryl is replaced with deuterium, cyano, or halogen. The halogen is fluorine, chlorine, bromine, or iodine, preferably fluorine, chlorine, or bromine, more preferably fluorine or chlorine, and even more preferably fluorine. Furthermore, from the viewpoint of durability, it is also preferable that all or some of the hydrogen in the structure containing the structural unit represented by formula (1) is deuterated.

[0156] <Specific examples of polycyclic aromatic compounds having a structure containing the structural unit represented by formula (1)> Specific examples of polycyclic aromatic compounds having a structure containing the structural unit represented by formula (1) include polycyclic aromatic compounds represented by any of the following formulas. In each of the following formulas, at least one hydrogen may be replaced by an alkyl group, a phenyl group which may be substituted with an alkyl group, a diphenylamino group which may be substituted with an alkyl group, a carbazolyl group which may be substituted with an alkyl group, or a deuterium group.

[0157] [ka]

[0158] [ka]

[0159] Further specific examples of polycyclic aromatic compounds having a structure containing the structural unit represented by formula (1) include the following compounds. However, polycyclic aromatic compounds having a structure containing the structural unit represented by formula (1) are not limited to the following specific examples.

[0160] [ka]

[0161] [ka]

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[0172] <Polycyclic aromatic compounds having a structure containing structural units represented by formula (2)> Among polycyclic aromatic compounds having a structure containing the structural unit represented by formula (1), particularly organic When used as a hole transport layer material or a host material in an EL element, polycyclic aromatic compounds having a structure containing the structural unit represented by the following formula (2) are preferred. When using a polycyclic aromatic compound having a structure containing the structural unit represented by formula (2) as a host material, it is preferable to use it as a hole transporting host material.

[0173] [ka]

[0174] In equation (2), Z is the same as Z in equation (1-a), etc., but in equation (2), R Z and adjacent R Z At least one of the substituents of the ring formed by the bonding of these groups is a group represented by a formula selected from the group consisting of formulas (A-1), (A-2), and (A-3). Amorphous stability is conferred by the group represented by the formula selected from the group consisting of formulas (A-1), (A-2), and (A-3). Furthermore, carrier transport properties can be adjusted by the group represented by the formula selected from the group consisting of formulas (A-1), (A-2), and (A-3).

[0175] In equation (2), R Z or adjacent R Z It is also preferable that the ring formed by the bonding of these elements does not contain substituents other than those represented by formulas selected from the group consisting of formulas (A-1), (A-2), and (A-3).

[0176] R Z If there is no ring formed by the bonding of the elements, R Z At least one of them is a base represented by an equation selected from the group consisting of equations (A-1), (A-2), and (A-3). Z If there is a ring formed by the bonding of two elements, R Z and adjacent R Z At least one of the groups selected from the group consisting of hydrogen-substituting groups in the ring formed by the bonding of these groups is a group represented by a formula selected from the group consisting of formulas (A-1), (A-2), and (A-3). The number of bases (CR) represented by formulas selected from the group consisting of formulas (A-1), (A-2), and (A-3) that are included in formula (2) as described above. Z It is either directly bonded to C in or R Z The number of groups represented by formulas selected from the group consisting of formulas (A-1), (A-2), and (A-3) that are directly bonded to the ring constituent atoms of the ring formed by the bonding of these groups is preferably 1 to 4, and more preferably 1 or 2.

[0177] [ka]

[0178] In formula (A-1), W 1 and W 2 These are independent single bonds, >C(-R W )2, >O, >NR W ,>Si(-R W )2, >S, >SO or >SO2, and the >NR W R Wis any substituent selected from substituent group Z, a group represented by formula (A-2), or a group represented by formula (A-3), and the >C(-R W )2, >Si(-R W )2 R W Each of these is independently a hydrogen atom, one of the substituents selected from substituent group Z, a group represented by formula (A-2), or a group represented by formula (A-3). R is bonded to the same element. W They may be coupled to each other, >NR W ,>C(-R W )2, >Si(-R W )2 R W Each of these may be independently coupled with at least one Y. Y is N or CR Y And R Y Each of these is independently hydrogen, one of the substituents selected from substituent group Z, a group represented by formula (A-2), or a group represented by formula (A-3). R in adjacent Y Y These elements may be bonded to each other to form an aryl ring or a heteroaryl ring. The formed ring may also have any substituent selected from substituent group Z, a group represented by formula (A-2), or a group represented by formula (A-3). L 1 It is a single bond or a linking group. L 1 is R Y Using as a connecting hand, any CR Y Is it bonded to C, or R W Using as the coupling >C(-R W )2 C, >NR W N, >O, >Si(-R W )Bonded to Si in 2, or R in Y Y These atoms are bonded to the ring-forming atoms of a ring that is formed by the bonding of these atoms to each other. * indicates the bonding position of the group represented by formula (A-1).

[0179] [ka]

[0180] In formula (A-2), Y is N or CR Y And R Y Each of these is independently hydrogen, one of the substituents selected from substituent group Z, a group represented by formula (A-1), or a group represented by formula (A-3). R in the adjacent Y Y These elements may be bonded to each other to form an aryl ring or a heteroaryl ring. The formed ring may also have any substituent selected from substituent group Z, a group represented by formula (A-1), or a group represented by formula (A-3). L 2 It is a single bond or a linking group. L 2 is R Z Using as a connecting hand, any CR Z It is bonded to C, or R in Z. Z These atoms are bonded to the ring-forming atoms of a ring that is formed by the bonding of these atoms to each other. * indicates the bonding position of the group represented by formula (A-2).

[0181] [ka]

[0182] In formula (A-3), Ar 3 Each of these is independently an aryl which may be substituted with at least one substituent selected from substituent group Z or a group represented by formula (A-1) or formula (A-2), a heteroaryl which may be substituted with at least one substituent selected from substituent group Z or a group represented by formula (A-1) or formula (A-2), or a group represented by formula (A-1) or formula (A-2). W 3 is Si, P or S, and W 3 When is Si, then m is 3 and n is 0, and W 3 When P is, then m is 2 and n is 0 or 1, and W 3 When S is true, then m is 1 and n is an integer between 0 and 2. L 2It is a single bond or a linking group. L 3 is R Z Using as a connecting hand, any CR Z It is bonded to C, or R in Z. Z These atoms are bonded to the ring-forming atoms of a ring that is formed by the bonding of these atoms to each other. * indicates the bonding position of the group represented by formula (A-3).

[0183] In equation (A-1) or equation (A-2), L 1 , L 2 and L 3 Each of these is independently either a single bond or an arylene, heteroarylene, >NR L ,>O,>C(-R L )2, >Si(-R L )2, >S, >Se, and any combination of two or more of these groups are preferred as linking groups. 1 , L 2 and L 3 Each is independently an arylene which may be substituted with a single bond or an aryl or heteroaryl bond, a heteroarylene which may be substituted with an aryl or heteroaryl bond, >NR L ,>O,>C(-R L )2, >Si(-R L )2 is more preferably a linking group selected from the group consisting of groups consisting of >S, >Se and two or more combinations thereof.

[0184] L 1 , L 2 and L 3 Inside >NR L ,>C(-R L )2 and >Si(-R L )R in 2 L Each of these is independently a hydrogen atom, a substituent selected from substituent group Z, or a group represented by formula (A-3), and R is bonded to the same element. L They may be bound to each other.

[0185] L1 , L 2 and L 3 Inside >NR L In R L Preferably, the aryl is substituted with an aryl or heteroaryl, or the heteroaryl is substituted with an aryl or heteroaryl. 1 , L 2 and L 3 Inside >C(- L R)2 in R L It is preferable that both R's are alkyl, and that two R's, both alkyl, are bonded together to form a cycloalkane such as cyclohexane. 1 , L 2 and L 3 Si(-R) L )R in 2 L Preferably, all of them are methyl.

[0186] L 1 , L 2 and L 3 Preferably, the linking group is composed of two or more selected from a single bond, an arylene which may be substituted with an aryl or heteroaryl, a heteroarylene which may be substituted with an aryl or heteroaryl, or an arylene which may be substituted with an aryl or heteroaryl and a heteroarylene which may be substituted with an aryl or heteroaryl. More preferably, the linking group is formed by linking two or more arylenes that may be substituted with an aryl or heteroaryl group, heteroarylenes that may be substituted with an aryl or heteroaryl group, or arylenes that may be substituted with an aryl or heteroaryl group and heteroarylenes that may be substituted with an aryl or heteroaryl group.

[0187] L 1 , L 2 and L 3In the formula, the arylene which may be substituted with an aryl or heteroaryl group and the heteroarylene which may be substituted with an aryl or heteroaryl group preferably have bond positions that are cross-conjugated. For example, the phenylene is preferably 1,3-phenylene.

[0188] L 1 , L 2 and L 3 Examples of such linking groups include those represented by the following formula. In the following formula, * indicates a bond position, and CR occurs at either *. Z R in C or Z Z The ring atoms of the ring formed by the bonding of these atoms to each other are bonded, while L in formula (A-1) is bonded to the ring atoms of the ring. 1 Other substructures, L in equation (A-2) 2 Other substructures or L in formula (A-3) 3 Assume that it is bound to any other substructure.

[0189] [ka]

[0190] In the group represented by formula (A-1), W 1 or W 2 ga>NR W When R is such W It is preferable that the compound is a substituted or unsubstituted aryl compound or a substituted or unsubstituted heteroaryl compound. W -R W The link becomes L 1 It is also preferable that it is bonded to it. In the group represented by formula (A-1), W 1 or W 2 >C(-R W ) When R is 2 W Preferably, both R are substituted or unsubstituted aryl compounds, or both are substituted or unsubstituted heteroaryl compounds. WThe fact that they are bonded by a single bond is also preferable as it provides excellent compound stability. W It is more preferable that all of these are phenyl compounds, and that these phenyl compounds are linked to each other by single bonds. In the group represented by formula (A-1), W 1 or W 2 >Si(-R W ) When R is 2 W Preferably, both R are substituted or unsubstituted aryl compounds, or both are substituted or unsubstituted heteroaryl compounds. W The fact that they are bonded by a single bond is also preferable as it provides excellent compound stability. W It is more preferable that all of these are phenyl compounds, and that these phenyl compounds are linked to each other by single bonds.

[0191] In the base represented by formula (A-1), W 1 ga>NR W ,>C(-R W )2, >O, >Si(-R W )2 or >S and W 2 It is preferable that the bond is a single bond, because it offers excellent compound stability and carrier transport. 1 ga>NR W , >O or >S and W 2 It is more preferable that the bond is a single bond, W 1 NR W and W 2 It is even more preferable that the bond is a single bond. W is L 1 It is particularly preferable that the connection is with the following.

[0192] W 1 or W 2 It is >NR W ,>C(-R W )2,>Si(-R W )2 R W Each of these may be independently coupled with at least one Y. 1 or W 2 It is >NR WExamples of structures in which Y is combined include the following structure.

[0193] [ka]

[0194] In the base represented by formula (A-1), 0 to 2 Ys are N, and the rest are CR. Y It is preferable that 0 to 1 Y is N and the rest are CR Y It is more preferable that all Y are CR Y It is even more preferable that it be R Y Preferably, each of these is independently a hydrogen, an aryl which may be substituted with an aryl or heteroaryl, a heteroaryl which may be substituted with an aryl or heteroaryl, a diheteroarylamino which may be substituted with an aryl or heteroaryl, or an arylheteroarylamino which may be substituted with an aryl or heteroaryl. This is because of good carrier transport properties. The aryl or heteroaryl substituent may be further substituted with an aryl or heteroaryl. In the group represented by formula (A-1), R Y CR is other than hydrogen Y It is preferable that there be 0 to 3 of them. This is because it provides good amorphous stability. Y CR is other than hydrogen Y It is more preferable that there be 0 to 2 R atoms, and even more preferable that there be 0 to 1 R atom in the group represented by formula (A-1). Y Preferred members are N-carbazolyl, a group represented by formula (A-2), or a group represented by formula (A-3).

[0195] In the base represented by formula (A-1), adjacent CR Y Two R in Y YThese elements may bond to each other to form an aryl ring or a heteroaryl ring. Examples of groups represented by formula (A-1) that form an aryl ring or heteroaryl ring in this way include groups represented by any of the following formulas.

[0196] [ka] In the formula, * indicates a bonding position.

[0197] Furthermore, the formed ring may have substituents. The number of substituents is preferably 0 to 2, and more preferably 0 to 1. The substituents are preferably aryl, heteroaryl, diheteroarylamino, or arylheteroarylamino, which may be substituted with an aryl or heteroaryl molecule.

[0198] L 1 is R Y Using as a connecting hand, any CR Y Is it bonded to C, or R W Using as the coupling >C(-R W )2 C, >NR W N, >O, >Si(-R W )Bonded to Si in 2, or R in Y Y They are directly bonded to the ring-forming atoms of the ring formed by the bonding of these atoms to each other. In the group represented by formula (A-1), the W is not a single bond. 1 In L 1 It is preferable that it is coupled to >NR. W N and L 1 It is preferable that the two are bonded together.

[0199] In the base represented by formula (A-2), 0 to 3 Ys are N, and the rest are CR. Y Preferably, 1 to 3 Y's are N, and the others are CR. YIt is more preferable that the multiple Ns are not adjacent to each other. Specifically, the group represented by formula (A-2) has five Ys and Ns that form a pyridine ring, pyrimidine ring, pyrazine ring, or triazine ring, or Rs that are substituted on adjacent carbons in these rings. Y It is preferable that these elements bond to each other to form an aryl ring or heteroaryl ring, which is a quinoline ring, isoquinoline ring, quinoxaline ring, quinazoline ring, or purine ring. Y Preferably, each of these is independently hydrogen, an aryl which may be substituted with an aryl or heteroaryl, a heteroaryl which may be substituted with an aryl or heteroaryl, a diheteroarylamino which may be substituted with an aryl or heteroaryl, or an arylheteroarylamino which may be substituted with an aryl or heteroaryl. This is because of good carrier transport properties. The R of adjacent Y Y The same applies to substituents when they are bonded to each other to form an aryl ring or heteroaryl ring. The aryl or heteroaryl substituent may be further substituted with aryl or heteroaryl. In the group represented by formula (A-2), R Y CR is other than hydrogen Y It is preferable that there be 0 to 3 of them. This is because it provides good amorphous stability. Y CR is other than hydrogen Y It is more preferable that there be 0 to 2 of them, and even more preferable that there be 0 to 1 of them.

[0200] In the group represented by formula (A-3), Ar 3 Each of these is preferably an aryl group (excluding the group represented by formula (A-1)) which may be substituted with an aryl or heteroaryl group, a heteroaryl group (excluding the group represented by formula (A-1)) which may be substituted with an aryl or heteroaryl group, or a group represented by formula (A-1), and is preferably an unsubstituted aryl group, an unsubstituted heteroaryl group, or a group represented by formula (A-1). In the group represented by formula (A-3), a large value of m is preferable for superior electron transport performance. In the base represented by formula (A-3), W 3 It is preferable that the compound is composed of Si due to its excellent compound stability. In the base represented by formula (A-3), W 3 It is most preferable that is Si, m is 3, and n is 0.

[0201] <Specific examples of polycyclic aromatic compounds having a structure containing the structural unit represented by formula (2)> Further specific examples of polycyclic aromatic compounds having a structure containing the structural unit represented by formula (2) include the following compounds. However, polycyclic aromatic compounds having a structure containing the structural unit represented by formula (2) are not limited to the following specific examples.

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[0203] [ka]

[0204] [ka]

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[0206] [ka]

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[0214] <Method for producing polycyclic aromatic compounds> Polycyclic aromatic compounds represented by formulas (1) and (2) and their polymers are basically formed by first bonding a fused ring containing the A ring (a ring), B ring (b ring), and C ring (c ring) with a bonding group (X 1 An intermediate can be prepared by bonding the rings (containing the ring) and a single bond (first reaction), and then the final product can be prepared by bonding the fused ring containing the A ring (a ring), B ring (b ring), and C ring (c ring) with boron (second reaction). In the first reaction, for example, if it is an etherification reaction, general reactions such as nucleophilic substitution reactions and Ullmann reactions can be used, and if it is an amination reaction, general reactions such as the Buchwald-Hartwig reaction can be used. In the second reaction, a tandem hetero-Friedel-Crafts reaction (sequential aromatic electrophilic substitution reaction, the same applies below) can be used.

[0215] The second reaction is the introduction of boron to bond the fused rings containing the A ring (a ring), B ring (b ring), and C ring (c ring), as shown in schemes (1) and (2) below. First, X 1The halogen atom between the nitrogen atom and the lithium atom is exchanged using n-butyllithium, sec-butyllithium, or t-butyllithium, etc. Then, boron trichloride or boron tribromide, etc., is added to perform a lithium-boron metal exchange, and a Brønsted base such as N,N-diisopropylethylamine is added to carry out a tandem bora-Friedel-Crafts reaction to obtain the target product. In the second reaction, a Lewis acid such as aluminum trichloride may be added to accelerate the reaction.

[0216] [ka]

[0217] While schemes (1) and (2) above mainly show methods for producing polycyclic aromatic compounds represented by formulas (1) and (2), their polymers can be produced by using intermediates having multiple A rings (a-rings), B rings (b-rings), and C rings (c-rings).

[0218] By appropriately selecting the raw materials to be used, polycyclic aromatic compounds having substituents at desired positions and their polymers can be synthesized.

[0219] Specific examples of solvents used in the above reactions include t-butylbenzene and xylene.

[0220] Furthermore, in the synthesis methods of schemes (1) and (2) above, before adding boron trichloride, boron tribromide, etc., X 1 An example of a tandem hetero-Friedel-Crafts reaction was shown, where the halogen atom between the nitrogen atom and the halogen atom was replaced with a halogen-metal exchange using butyllithium or the like. However, the reaction can also be carried out by adding boron trichloride or boron tribromide to a precursor in which the halogen has been replaced with hydrogen.

[0221] Examples of orthometalating reagents used in schemes (1) and (2) above include alkyllithium compounds such as methyllithium, n-butyllithium, sec-butyllithium, and t-butyllithium, as well as organic alkali compounds such as lithium diisopropylamide, lithium tetramethylpiperidide, lithium hexamethyldisilazide, and potassium hexamethyldisilazide.

[0222] Examples of metal-boron metal exchange reagents used in schemes (1) and (2) above include boron halides such as boron trifluoride, boron trichloride, boron tribromide, and boron triiodide, as well as boron alkoxylateds and boron aryl oxylateds.

[0223] Examples of Brønsted bases used in schemes (1) and (2) above include N,N-diisopropylethylamine, triethylamine, 2,2,6,6-tetramethylpiperidine, 1,2,2,6,6-pentamethylpiperidine, N,N-dimethylaniline, N,N-dimethyltoluidine, 2,6-lutidine, sodium tetraphenylborate, potassium tetraphenylborate, triphenylborane, tetraphenylsilane, Ar4BNa, Ar4BK, Ar3B, Ar4Si (where Ar is an aryl such as phenyl).

[0224] Examples of Lewis acids used in schemes (1) and (2) above include AlCl3, AlBr3, AlF3, BF3·OEt2, BCl3, BBr3, GaCl3, GaBr3, InCl3, InBr3, In(OTf)3, SnCl4, SnBr4, AgOTf, ScCl3, Sc(OTf)3, ZnCl2, ZnBr2, Zn(OTf)2, MgCl2, MgBr2, Mg(OTf)2, LiOTf, NaOTf, KOTf, Me3SiOTf, Cu(OTf)2, CuCl2, YCl3, Y(OTf)3, TiCl4, TiBr4, ZrCl4, ZrBr4, FeCl3, FeBr3, CoCl3, CoBr3, and others.

[0225] In schemes (1) and (2) above, a Brønsted base or Lewis acid may be used to accelerate the tandem hetero-Friedel-Crafts reaction. However, when using boron halides such as boron trifluoride, boron trichloride, boron tribromide, and boron triiodide, acids such as hydrogen fluoride, hydrogen chloride, hydrogen bromide, and hydrogen iodide are generated as the aromatic electrophilic substitution reaction progresses, so the use of a Brønsted base to capture the acid is effective. On the other hand, when using boron amination halides or boron alkoxyides, amines and alcohols are generated as the aromatic electrophilic substitution reaction progresses, so in most cases, it is not necessary to use a Brønsted base. However, because the leaving ability of aminos and alkoxys is low, the use of a Lewis acid to promote their elimination is effective.

[0226] Furthermore, polycyclic aromatic compounds having a structure containing the structural unit represented by formula (2) can also be synthesized by synthesizing a compound represented by formula (1-b) containing a reactive substituent such as a halogen using the above scheme, and then cross-coupling it with an arbitrary substituent. Common cross-coupling reactions such as the Ullmann reaction, the Buchwald-Hartwig reaction, and the Suzuki-Miyaura reaction can be used.

[0227] Furthermore, the polycyclic aromatic compounds of the present invention include those in which at least some hydrogen atoms are substituted with deuterium or halogens such as fluorine or chlorine. Such compounds can be synthesized in the same manner as described above by using raw materials in which the desired portion is deuterated, fluorinated, or chlorinated.

[0228] 2. Organic devices The polycyclic aromatic compounds of the present invention can be used as materials for organic devices. Examples of organic devices include organic field-light-emitting devices, organic field-effect transistors, and organic thin-film solar cells.

[0229] 2-1. Organic electroluminescent devices 2-1-1. Structure of an organic electroluminescent device Figure 1 is a schematic cross-sectional view showing an example of an organic EL element. The organic EL element 100 shown in Figure 1 comprises 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, a light-emitting layer 105 provided on the hole transport layer 104, an electron transport layer 106 provided on the light-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.

[0230] The organic EL element 100 may also be configured by reversing the manufacturing order, for example, by having 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 emissive layer 105 provided on the electron transport layer 106, a hole transport layer 104 provided on the emissive 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.

[0231] Not all of the above layers are necessarily required; the minimum configuration unit consists of an anode 102, a light-emitting layer 105, and a cathode 108, and the hole injection layer 103, hole transport layer 104, electron transport layer 106, and electron injection layer 107 are optional layers. Furthermore, each of the above layers may consist of a single layer or multiple layers.

[0232] In addition to the above-mentioned "substrate / anode / hole injection layer / hole transport layer / emissive layer / electron transport layer / electron injection layer / cathode" configurations, other configurations of layers constituting an organic EL element include "substrate / anode / hole transport layer / emissive layer / electron transport layer / electron injection layer / cathode", "substrate / anode / hole injection layer / emissive layer / electron transport layer / electron injection layer / cathode", "substrate / anode / hole injection layer / hole transport layer / emissive layer / electron injection layer / cathode", and "substrate / anode / hole injection layer / hole transport layer / emissive layer / electron transport The configuration may also be "transport layer / cathode", "substrate / anodode / emissive layer / electron transport layer / electron injection layer / cathode", "substrate / anodode / hole transport layer / emissive layer / electron injection layer / cathode", "substrate / anodode / hole transport layer / emissive layer / electron transport layer / cathode", "substrate / anodode / hole injection layer / emissive layer / electron injection layer / cathode", "substrate / anodode / hole injection layer / emissive layer / electron transport layer / cathode", "substrate / anodode / emissive layer / electron transport layer / cathode", or "substrate / anodode / emissive layer / electron injection layer / cathode".

[0233] 2-1-2. Substrates in Organic Electroluminescent Devices The substrate 101 is a support for the organic EL element 100, and is typically made of quartz, glass, metal, or plastic. Depending on the purpose, the substrate 101 may be formed in the form of a plate, film, or sheet, and examples include glass plates, metal plates, metal foils, plastic films, and plastic sheets. Among these, glass plates and transparent synthetic resin plates such as polyester, polymethacrylate, polycarbonate, and polysulfone are preferred. If a glass substrate is used, soda-lime glass or alkali-free glass may be used, and the thickness should be sufficient to maintain mechanical strength. In addition, to enhance the gas barrier properties, a dense gas barrier film, such as a silicon oxide film, may be provided on at least one side of the substrate 101, and it is particularly preferable to provide a gas barrier film when using a synthetic resin plate, film, or sheet with low gas barrier properties as the substrate 101.

[0234] 2-1-3. Anode in an Organic Electroluminescent Device The anode 102 plays the role of injecting holes into the light-emitting layer 105. If at least one of the hole injection layer 103 and hole transport layer 104 is provided between the anode 102 and the light-emitting layer 105, holes will be injected into the light-emitting layer 105 via these layers.

[0235] 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), conductive polymers such as polypyrrole and polyaniline. In addition, other materials used as anodes in organic EL elements can be appropriately selected and used.

[0236] 2-1-4. Hole injection layer and hole transport layer in organic electroluminescent element The hole injection layer 103 plays the 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 the role of efficiently transporting holes injected from the anode 102 or holes injected from the anode 102 via the hole injection layer 103 to the light-emitting layer 105. The hole injection layer 103 and the hole transport layer 104 are each formed by laminating or mixing one or more types of hole injection / transport materials. Alternatively, an inorganic salt such as iron(III) chloride may be added to the hole injection / transport material to form a layer.

[0237] For hole-injecting and transporting materials, it is necessary to efficiently inject and transport holes from the positive electrode between electrodes under an applied electric field. Therefore, high hole injection efficiency and efficient transport of injected holes are desirable. To achieve this, it is preferable to use a material with a low ionization potential, high hole mobility, excellent stability, and minimal generation of trapping impurities during manufacturing and use. It is also preferable to use a polycyclic aromatic compound having a structure containing the structural unit represented by formula (2) as the material for the hole transport layer.

[0238] As the material for forming the hole injection layer 103 and the hole transport layer 104, any compound can be selected from among compounds conventionally used as charge transport materials for holes in photoconductive materials, p-type semiconductors, and known compounds used in hole injection layers and hole transport layers of organic EL devices. Specific examples include carbazole derivatives (N-phenylcarbazole, polyvinylcarbazole, etc.), biscarbazole derivatives such as bis(N-arylcarbazole) or bis(N-alkylcarbazole), and triarylamine derivatives (polymers having aromatic tertiary amino acids in the main chain or side chain, 1,1-bis(4-di-p-tolylaminophenyl)cyclohexane, N,N'-diphenyl-N,N'-di(3-methylphenyl)-4,4'-diaminobiphenyl, N,N'-diphenyl-N,N'-dinaphthyl-4,4'-diaminobiphenyl, N,N'-diphenyl-N,N'-di(3-methylphenyl)-4,4'-diphenyl-1,1'-diamine, N,N'-dinaphthyl-N,N'-diphenyl-4,4'-diphenyl-1,1'-diamine, N 4 ,N 4' -diphenyl-N 4 ,N 4' -Bis(9-phenyl-9H-carbazole-3-yl)-[1,1'-biphenyl]-4,4'-diamine, N 4 ,N 4 ,N 4' ,N 4'Triphenylamine derivatives such as -tetra[1,1'-biphenyl]-4-yl)-[1,1'-biphenyl]-4,4'-diamine, 4,4',4"-tris(3-methylphenyl(phenyl)amino)triphenylamine, starburstamine derivatives, etc., stilbene derivatives, phthalocyanine derivatives (metal-free, copper phthalocyanine, etc.), pyrazoline derivatives, hydrazone compounds, benzofuran derivatives and thiophene derivatives, oxadiazole derivatives, quinoxaline derivatives Examples include conductors (e.g., 1,4,5,8,9,12-hexaazatriphenylene-2,3,6,7,10,11-hexacarbonitrine), heterocyclic compounds such as porphyrin derivatives, and polysilanes. Among polymer systems, polycarbonates, styrene derivatives, polyvinylcarbazoles, and polysilanes having the monomers in their side chains are preferred, but the compound is not particularly limited as long as it can form a thin film necessary for fabricating a light-emitting device, allow holes to be injected from the anode, and transport holes.

[0239] Furthermore, the conductivity of organic semiconductors is known to be strongly influenced by doping. Such organic semiconductor matrix materials are composed of compounds with good electron-donating properties or compounds with good electron-accepting properties. Strong electron acceptors such as tetracyanoquinone dimethane (TCNQ) or 2,3,5,6-tetrafluorotetracyano-1,4-benzoquinone dimethane (F4TCNQ) are known for doping with electron-donating substances (see, for example, "M. Pfeiffer, A. Beyer, T. Fritz, K. Leo, Appl. Phys. Lett., 73(22), 3202-3204 (1998)" and "J. Blochwitz, M. Pfeiffer, T. Fritz, K. Leo, Appl. Phys. Lett., 73(6), 729-731 (1998)"). These generate so-called holes through an electron transfer process in the electron-donating base material (hole transporter). The conductivity of the base material changes considerably depending on the number and mobility of holes. Examples of matrix materials having hole transport properties include benzidine derivatives (such as TPD) or starburst amine derivatives (such as TDATA), or certain metal phthalocyanines (especially zinc phthalocyanine (ZnPc)) (Japanese Patent Publication No. 2005-167175).

[0240] The hole injection layer material and hole transport layer material described above can also be used as a hole layer material in the form of a polymer compound obtained by polymerizing a reactive compound in which a reactive substituent is substituted as a monomer, or a polymer crosslink thereof, or a pendant-type polymer compound obtained by reacting a main-chain polymer with the reactive compound, or a pendant-type polymer crosslink thereof.

[0241] 2-1-5. Light-emitting layer in organic electroluminescent device The polycyclic aromatic compounds of the present invention are preferably used as materials for forming one or more organic layers in an organic electroluminescent device, and more preferably as materials 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 with electrons injected from the cathode 108 between electrodes to which an electric field is applied. The material for forming the light-emitting layer 105 can be any compound that emits light when excited by the recombination of holes and electrons (luminescent compound), and it is preferable that the compound can form a stable thin film shape and exhibits strong luminescence (fluorescence) efficiency in the solid state. The polycyclic aromatic compounds of the present invention can be used as materials for light-emitting layers, and may be used as dopant materials or as host materials, but are preferably used as dopant materials. However, polycyclic aromatic compounds having a structure containing the structural unit represented by formula (2) are preferably used as host materials.

[0242] Polycyclic aromatic compounds and the like having a structure containing the structural unit represented by formula (1) can exhibit thermally activated delayed fluorescence (TADF) as "thermally activated delayed phosphors". In "thermally activated delayed phosphors", by reducing the energy difference between the lowest excited singlet state and the lowest excited triplet state, the reverse intersystem cross-transition from the lowest excited triplet state to the lowest excited singlet state, which normally has a low transition probability, is generated with high efficiency, and emission from the singlet state (thermally activated delayed fluorescence, TADF) is produced. In normal fluorescence emission, 75% of the triplet excitons generated by electric excitation pass through the thermal deactivation pathway and cannot be extracted as fluorescence. On the other hand, in TADF, all excitons can be used for fluorescence emission, enabling the realization of highly efficient organic EL devices.

[0243] Polycyclic aromatic compounds having a structure containing a structural unit represented by formula (1) can be used in the organic electroluminescent device of the present invention as an emitting dopant for a TADF element using one type of host material, an emitting dopant for a TADF element using a hole-transporting host material and an electron-transporting host material, an emitting dopant for an organic electroluminescent device (TADF-assisted fluorescent element, TAF element) using another thermally activated delayed phosphor as an assisting dopant, or an emitting dopant for an organic electroluminescent device (phosphor-sensitized fluorescent element, PSF element) using a phosphorescent material as an assisting dopant.

[0244] The light-emitting layer may consist of a single layer or multiple layers, each formed from a light-emitting layer material (host material, dopant material). The host material and dopant material may each be of one type or a combination of multiple types. The dopant material may be contained throughout the host material or partially contained within it. As for the doping method, it can be formed by co-deposition with the host material, but it may also be mixed with the host material beforehand and then deposited simultaneously.

[0245] The amount of host material used varies depending on the type of host material and should be determined according to the characteristics of that host material. The guideline for the amount of host material used is preferably 50 to 99.999% by mass of the total mass of the light-emitting layer material, more preferably 80 to 99.95% by mass, and even more preferably 90 to 99.9% by mass.

[0246] The amount of dopant material used varies depending on the type of dopant material and should be determined according to the characteristics of that dopant material. A guideline for the amount of dopant used is preferably 0.001 to 50% by mass of the total mass of the light-emitting layer material, more preferably 0.05 to 20% by mass, and even more preferably 0.1 to 10% by mass. Within this range, for example, it is preferable in that it can prevent density quenching.

[0247] As the dopant material, an emitting dopant and an assisting dopant material may be used. It is preferable to use a thermally activated delayed fluorescence material as the assisting dopant material. In an organic electroluminescent device using an assisting dopant material, a low concentration of the emitting dopant material is preferable in that it prevents concentration quenching. A high concentration of the assisting dopant material is preferable in terms of the efficiency of the thermally activated delayed fluorescence mechanism. Furthermore, in an organic electroluminescent device using a thermally activated delayed fluorescence assisting dopant material, from the viewpoint of the efficiency of the thermally activated delayed fluorescence mechanism of the assisting dopant material, it is preferable that the amount of emitting dopant material used is lower than the amount of assisting dopant material used.

[0248] When assisting dopant materials are used, the approximate amounts of host material, assisting dopant material, and emitting dopant material used are 40-99% by mass, 59-1% by mass, and 20-0.001% by mass, respectively, relative to the total mass of the material for the light-emitting layer. Preferably, these amounts are 60-95% by mass, 39-5% by mass, and 10-0.01% by mass, respectively, and more preferably 70-90% by mass, 29-10% by mass, and 5-0.05% by mass.

[0249] <Host Materials> Examples of host materials include condensed ring derivatives such as anthracene and pyrene, which have been known as luminescent materials for some time; bisstyryl derivatives such as bisstyrylanthracene derivatives and distyrylbenzene derivatives; tetraphenylbutadiene derivatives; cyclopentadiene derivatives; fluorene derivatives; benzofluorene derivatives; N-phenylcarbazole derivatives; and carbazonitrile derivatives. From the viewpoint of promoting rather than inhibiting the generation of TADF in the emissive layer, the lowest excited triplet energy level of the host material is preferably higher than the lowest excited triplet energy level of the dopant or assisting dopant having the highest lowest excited triplet energy level in the emissive layer. Specifically, the triplet energy of the host material is preferably 0.01 eV or higher, more preferably 0.03 eV or higher, and even more preferably 0.1 eV or higher. In addition, a TADF-active compound may be used as the host material.

[0250] The host material may be a single type or a combination of multiple types. If multiple types are used, a combination of a hole-transporting host material and an electron-transporting host material is preferred.

[0251] Polycyclic aromatic compounds having a structure containing the structural unit represented by formula (2) can also be used as host materials.

[0252] [Anthracene derivatives] For anthracene derivatives, refer to paragraphs 0124-0192 of Japanese Patent Publication No. 2020-136284 and paragraphs 0072-0257 of Japanese Patent Publication No. 2021-118354. Specifically, examples of anthracene derivatives include compounds represented by formula (3-H) or compounds represented by formula (3-H2).

[0253] [ka]

[0254] In formula (3-H), X and Ar 4 Each is independently a hydrogen atom or a group selected from the substituent group Z, and all X and Ar 4 They cannot become hydrogen at the same time. At least one hydrogen atom in the compound represented by formula (3-H) may be replaced by a halogen, cyano, or deuterium.

[0255] In formula (3-H2), Ar c R is a substituted or unsubstituted aryl or a substituted or unsubstituted heteroaryl, c is hydrogen, alkyl, or cycloalkyl, and Ar 11 Ar 12 Ar 13 Ar 14 Ar 15 Ar 16 Ar 17 , and Ar 18 Each of these is independently a hydrogen atom or a group selected from substituent group Z, and at least one hydrogen atom in the compound represented by formula (3-H2) may be replaced by a halogen, cyano, or deuterium.

[0256] In the compound represented by formula (3-H), X is preferably independently a group represented by formula (3-X1), formula (3-X2), or formula (3-X3), where the groups represented by formula (3-X1), formula (3-X2), or formula (3-X3) bond to the anthracene ring of formula (3-H) at *. Preferably, two X groups do not simultaneously become a group represented by formula (3-X3). More preferably, two X groups do not simultaneously become a group represented by formula (3-X2).

[0257] [ka]

[0258] Furthermore, a polymer (preferably a dimer) may be formed using the structure represented by formula (3-H) as the unit structure. In this case, for example, the unit structures represented by formula (3-H) may be bonded together via X, and X may be a single bond, arylene (phenylene, biphenylene, naphthylene, etc.), and heteroarylene (pyridine ring, dibenzofuran ring, dibenzothiophene ring, carbazole ring, benzocarbazole ring, and phenyl-substituted carbazole ring, etc., which are groups having a divalent bond value).

[0259] The naphthylene moieties in formulas (3-X1) and (3-X2) may be condensed with a single benzene ring. The resulting structure is as follows: [ka]

[0260] Ar 1 and Ar 2 Each of these is independently hydrogen, phenyl, biphenylyl, terphenylyl, quaterphenylyl, naphthyl, phenanthryl, fluorenyl, benzofluorenyl, crisenyl, triphenylenyl, pyrellyl, or a group represented by formula (A) (including carbazolyl, benzocarbazolyl, and phenyl-substituted carbazolyl). 1 or Ar 2 If the group is represented by formula (A), then the group represented by formula (A) is bonded to the naphthalene ring in formula (3-X1) or formula (3-X2) at its *.

[0261] Ar 3 This refers to phenyl, biphenylyl, terphenylyl, quaterphenylyl, naphthyl, phenanthryl, fluorenyl, benzofluorenyl, crisenyl, triphenylenyl, pyrellyl, or a group represented by formula (A) (including carbazolyl, benzocarbazolyl, and phenyl-substituted carbazolyl). Note that Ar 3 If the group is represented by formula (A), then the group represented by formula (A) bonds with the single bond represented by the line in formula (3-X3) at its *. That is, the anthracene ring of formula (3-H) and the group represented by formula (A) bond directly.

[0262] Also, Ar 3 It may have substituents, Ar 3At least one hydrogen in may be further substituted with an alkyl group having 1 to 4 carbon atoms, a cycloalkyl group having 5 to 10 carbon atoms, a phenyl group, a biphenylyl group, a terphenylyl group, a naphthyl group, a phenanthryl group, a fluorenyl group, a crisenyl group, a triphenylenyl group, a pyrellyl group, or a group represented by formula (A) (including carbazolyl and phenyl-substituted carbazolyl groups). Note that Ar 3 If the substituent on is the group represented by formula (A), then the group represented by formula (A) is the Ar in formula (3-X3) in its * 3 It combines with it.

[0263] Ar 4 Preferably, each of these is independently a silyl substituted with hydrogen, phenyl, biphenylyl, terphenylyl, naphthyl, or a C1-C4 alkyl (methyl, ethyl, t-butyl, etc.) and / or a C5-C10 cycloalkyl.

[0264] Furthermore, the hydrogen atoms in the chemical structure of the anthracene compound represented by formula (3-H) may be replaced by the group represented by formula (A). When replaced by the group represented by formula (A), the group represented by formula (A) replaces at least one hydrogen atom in the compound represented by formula (3-H) in that *.

[0265] The group represented by formula (A) is one of the substituents that the anthracene compound represented by formula (3-H) may have. [ka]

[0266] In equation (A), Y is -O-, -S-, or >NR 29 And R 21 ~R 28 Each of these is independently a hydrogen atom or a group selected from the substituent group Z, and 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, R 29is hydrogen or a substituted or unsubstituted aryl. Furthermore, at least one hydrogen in formula (A) may be replaced by a halogen, cyano, or deuterium. In equation (A), Y is preferably -O-.

[0267] [Hole-transporting host materials and electron-transporting host materials] Hole-transporting host materials (HH) and electron-transporting host materials (EH) satisfy the following relationship with respect to HOMO (Highest Occupied Molecular Orbital) and LUMO (Lowest Unoccupied Molecular Orbital). The homeosphere of hole-transporting host materials (HH) is shallower than that of electron-transporting host materials (EH), and the lumen-luminosity of electron-transporting host materials (EH) is deeper than that of hole-transporting host materials (HH). Furthermore, it is preferable that the HOMO of the emitting dopant is shallower than the HOMO of the hole-transporting host material (HH), or that the LUMO of the emitting dopant is deeper than the LUMO of the electron-transporting host material (EH).

[0268] Furthermore, the lowest excited triplet energy level (E) of hole-transporting host materials (HH) and electron-transporting host materials (EH) T1 ) is chosen from the viewpoint of promoting the generation of TADF within the light-emitting layer without inhibiting it, and is the highest E within the light-emitting layer. T1 Emitting dopant or assisting dopant having E T1 It is preferable that it be higher than the E of the host material. Specifically, the E of the host material T1 This refers to the E of the above-mentioned emitting dopant or assisting dopant. T1 It is preferable that it is 0.01 eV or more higher than, more preferably 0.03 eV or more higher, and even more preferably 0.1 eV or more higher than. Also, the E of the host material T1 The voltage is preferably 2.47 eV or higher, more preferably 2.49 eV or higher, and even more preferably 2.56 eV or higher.

[0269] Furthermore, it is preferable to use a hole-transporting host material in the hole transport layer adjacent to the light-emitting layer, and also to use an electron-transporting host material in the electron transport layer adjacent to this light-emitting layer. This is because carrier leakage and energy leakage from the light-emitting layer to adjacent layers are less likely to occur, resulting in a highly efficient organic EL device. The host material in the light-emitting layer (hole-transporting host material) and the hole transport layer material may be the same or different. Similarly, the host material in the light-emitting layer (electron-transporting host material) and the electron transport layer material may be the same or different.

[0270] [Hole-transporting host material (HH)] Examples of preferred hole-transporting host materials (HH) include the polycyclic aromatic compounds of the present invention having a structure containing the structural unit represented by formula (2), as well as compounds represented by formula (HH-1) and compounds having a substructure represented by formula (HH-1) and a structure containing at least three rings selected from the group consisting of aryl rings and heteroaryl rings. Preferably, these compounds do not contain any imine structure (-N=C-; including a heteroaryl ring substructure), boron (>B-), or cyano (CN).

[0271] [ka]

[0272] In equation (HH-1), Q is either >O, >S, or >NA H And, In formula (HH-1), the carbon atom adjacent to the carbon atom to which Q is bonded in each of the two phenyl molecules may be bonded to each other by L. L is a single bond, >O, >S, or >C(-A) H )2, A H is hydrogen, aryl, or heteroaryl, and >C(-A H )2 A H They may be bound to each other.

[0273] When a hole-transporting host material contains a substructure represented by formula (HH-1), it may contain one substructure 1, but it is also preferable to contain two or more. If it contains two or more substructures, the two or more substructures may be the same or different. The two or more substructures may be bonded to each other by single bonds, bonded so as to share any ring contained in the substructure, or bonded so as to be condensed between any rings contained in the substructure. The substructures may further have substituents selected from aryl, heteroaryl, diarylamino, or aryloxy.

[0274] Compounds represented by the above formula (HH-1), or compounds having a substructure represented by the formula (HH-1), have a structure comprising at least three rings selected from the group consisting of aryl rings and heteroaryl rings. The number of rings is preferably 6 or more, more preferably 8 or more. It is also preferably 20 or less, more preferably 15 or less, and even more preferably 10 or less. The number of rings refers to the number of monorings; for fused rings, it refers to the number of monorings constituting the fused ring.

[0275] The hole-transporting host material is preferably a compound containing one or more substructures selected from the group consisting of a triarylamine structure, a carbazole ring, a dibenzofuran ring, a dibenzothiophene ring, and a condensed polycyclic structure containing phenoxazine or phenothiazine. The hole-transporting host material may contain one such substructure 1, but it is also preferable to contain two or more. If it contains two or more substructures, the two or more substructures may be the same or different from each other.

[0276] Specific examples of hole-transporting host materials include the following compounds. [ka]

[0277] [ka]

[0278]

change

[0279]

change

[0280]

change

[0281]

change

[0282]

change

[0283]

change

[0284]

change

[0285]

change

[0286]

change

[0287]

change

[0288] [ka]

[0289] Of the above, HH-1-1, HH-1-2, HH-1-4 to HH-1-12, HH-1-17, HH-1-18, HH-1-20 to HH-1-24, HH-1-82, HH-1-84 to HH-1-89, HH-1-91, HH-1-92, and HH-1-106 to HH-1-114 are preferred.

[0290] [Electron-transporting host materials (EH)] Examples of electron-transporting host materials (EHs) include: Examples of compounds that have a structure represented by formulas (EH-1A) to (EH-1D), or a substructure represented by formulas (EH-1A) to (EH-1D), and that includes at least three rings selected from the group consisting of aryl rings and heteroaryl rings. [ka]

[0291] In equations (EH-1A) to (EH-1D), Ar is a heteroaryl ring that contains N=C as a substructure constituting the ring. Z is a single bond, -O-, -S-, or -N(-A) E )- and, A is bonded to the carbon atom adjacent to the carbon atom that Z is bonded to. E These can be connected by L, L is a single bond, >O, >S or >C(-A E )2, A E These are aryl, heteroaryl, or triarylsilyl compounds, and >C(-A E )2 A E They may be connected to each other, X is C, P, or S. When X is C, n=2 and m=1, When X is P, n=3 and m=1, When X is S, n=2 and m=1 to 2.

[0292] Compounds represented by the above formulas (EH-1A) to (EH-1D), or compounds having substructures represented by the above formulas (EH-1A) to (EH-1D), have a structure containing at least three rings selected from the group consisting of aryl rings and heteroaryl rings. The number of rings is preferably 4 or more, more preferably 6 or more, and even more preferably 8 or more. It is also preferably 20 or less, more preferably 15 or less, and even more preferably 10 or less. The number of rings refers to the number of monorings; for fused rings, it refers to the number of monorings constituting the fused ring.

[0293] When an electron-transporting host material contains a substructure represented by formulas (EH-1A) to (EH-1D), it may contain one substructure, but it is also preferable to contain two or more. If it contains two or more substructures, they may be the same or different from each other. The two or more substructures may be bonded to each other by single bonds, bonded so as to share any ring contained in the substructure, or bonded so as to be fused to any ring contained in the substructure. The substructures may further have substituents selected from aryl, heteroaryl, diarylamino, or aryloxy.

[0294] The following compounds are specific examples of electron-transporting host materials. [ka]

[0295] [ka]

[0296] [ka]

[0297] [ka]

[0298] [ka]

[0299] [ka]

[0300] [ka]

[0301] [ka]

[0302] [ka]

[0303] Another preferred example of an electron-transporting host material (a compound having a substructure represented by formula (EH-1)) is a polycyclic aromatic compound represented by the following formula (EH-1b), or a polymer of a polycyclic aromatic compound having multiple structures represented by the following formula (EH-1b). [ka]

[0304] In equation (EH-1b), R 1 , R 2 , R 3 , R 4 and R 5 (Hereinafter referred to as “R 1 Each of these (also called "etc.") is independently a hydrogen atom or a substituent selected from the substituent group Z. In equation (EH-1b), X 1 and X 2 These are, independently, >NR (amine nitrogen), >O, >C(-R)2, >S, or >Se, and X 1 and X 2 It is not possible for both to be >C(-R)2. In >NR and >C(-R)2, R is independently hydrogen or a substituent selected from substituent group Z, and may further be substituted with aryl, heteroaryl, alkyl, or cycloalkyl (the above are secondary substituents), and R in >NR and >C(-R)2 may independently be bonded to at least one of the a, b, and c rings by a linking group or a single bond. Y 1 , Y 2 , Y 3 , Y 4 , Y 5 and Y 6 (From here on, "Y 1 Each of these (also called "etc.") is independently either =C(-R)- or =N- (pyridine nitrogen), and at least one is =N- (pyridine nitrogen), In the above-mentioned =C(-R)-, R is independently selected from hydrogen or the substituent group Z. The aforementioned R 1 , R 2 , R 3 , R 4 and R 5 , and also, the Y 1 ~Y 6As =C(-R)-, adjacent R groups may bond together to form an aryl ring or heteroaryl ring with at least one of the a, b, and c rings, and at least one hydrogen in the formed ring may be substituted with aryl, heteroaryl, diarylamino, diheteroarylamino, arylheteroarylamino, diarylboryl (the two aryls may be bonded via a single bond or a linking group), alkyl, cycloalkyl, alkoxy or aryloxy (the above are the first substituents), and at least one hydrogen in these may be further substituted with aryl, heteroaryl, alkyl or cycloalkyl (the above are the second substituents). At least one hydrogen atom in the compound and structure represented by formula (1) may be substituted with cyano, halogen, or deuterium.

[0305] In equation (EH-1b), R 1 , R 2 , R 3 , R 4 and R 5 Both are hydrogen, or R 3 and R 4 Both are hydrogen, and R 1 , R 2 and R 5Preferably, one or more substituents selected from the group consisting of are other than hydrogen, and the others are hydrogen. Preferred substituents are alkyl, aryl which may be substituted with alkyl or heteroaryl, heteroaryl which may be substituted with alkyl or aryl, or diarylamino which may be substituted with alkyl or aryl. In this case, preferred alkyl is a C1-C6 alkyl (methyl, t-butyl, etc.), preferred aryl is phenyl or biphenyl, and preferred heteroaryl is triazinyl, carbazolyl (2-carbazolyl, 3-carbazolyl, 9-carbazolyl, etc.), pyrimidinyl, pyridinyl, dibenzofuranyl, or dibenzothienyl. Specific examples include phenyl, biphenyl, diphenyltriazinyl, carbazolyltriazinyl, monophenylpyrimidinyl, diphenylpyrimidinyl, carbazolyltriazinyl, pyridinyl, dibenzofuranyl, and dibenzothienyl.

[0306] Y 1 Each of these is independently =C(-R)- or =N-, and at least one of them is =N-. 1 ~Y 6 Either of these can be =N-. Preferably, Y 1 and Y 6 ga = N-(a ring is a pyrimidine ring), Y 1 or Y 6 ga = N-(a ring is a pyridine ring), Y 2 and Y 5 ga = N-(b-ring and c-ring are pyridine rings), Y 3 and Y 4 ga = N-(b-ring and c-ring are pyridine rings), Y 2 ~Y 5 ga = N-(b-ring and c-ring are pyrimidine rings), Y 1 , Y 3 , Y 4 and Y 6 ga = N - (a ring is a pyrimidine ring, b ring and c ring are pyridine rings), Y 1 , Y 2 , Y 5 and Y 6ga = N - (a ring is a pyrimidine ring, b ring and c ring are pyridine rings), Y 1 ~Y 6 ga = N - (a, b, and c rings are pyrimidine rings), Y 2 or Y 5 The formula is N-(where the b-ring or c-ring is a pyridine ring).

[0307] In addition to the above arrangement relationships of =N-, X 1 and X 2 It is preferable that >O, and that the polycyclic aromatic compound contains a substructure represented by any of the following formulas. [ka]

[0308] In particular, polycyclic aromatic compounds containing the substructure represented by formula (EH-1b-N1) have a higher E ratio compared to structures without N. S1 , high E T1 , small ΔE S1T1 It holds. Specific examples of polycyclic aromatic compounds represented by formula (EH-1b) are shown below.

[0309] [ka]

[0310] [ka]

[0311] [ka]

[0312] [ka]

[0313] [ka]

[0314] [ka]

[0315] Of the above, EH-1-1 to EH-1-4, EH-1-10, EH-1-21 to EH-1-25, EH-1-32, EH-1-33, EH-1-51 to EH-1-59, EH-1-61, EH-1-66, EH-1-68, EH-1-71, EH-1-72, EH-1-90, EH-1-100, EH-1-101, EH-1-104, EH-1-115, EH-1-117, EH-1-120, EH-1-122, EH-1-123, and EH-1-127 to EH-1-130 are preferred.

[0316] [Combination of hole-transporting host material and electron-transporting host material] The combination of hole-transporting host material and electron-transporting host material is selected based on the HOMO, LUMO, and excitation triplet energies of the hole-transporting host material, electron-transporting host material, and dopant material. With respect to HOMO and LUMO, a combination is selected in which the HOMO(HH) of the hole-transporting host material is shallower than the HOMO(EH) of the electron-transporting host material, and the LUMO(EH) of the electron-transporting host material is deeper than the LUMO(HH) of the hole-transporting host material. More specifically, a combination in which HOMO(HH) is 0.10 eV or more shallower than HOMO(EH) and LUMO(HH) is 0.10 eV or more deeper than HOMO(EH) is preferred, a combination in which HOMO(HH) is 0.20 eV or more shallower than HOMO(EH) and LUMO(HH) is 0.20 eV or more deeper than HOMO(EH) is more preferred, and a combination in which HOMO(HH) is 0.25 eV or more shallower than HOMO(EH) and LUMO(HH) is 0.25 eV or more deeper than HOMO(EH) is even more preferred.

[0317] The hole-transporting host material and the electron-transporting host material may be in combinations that form an aggregate called an exciplex. It is generally known that exciplexes are easily formed between a material with a relatively deep LUMO level and a material with a shallow HOMO level. The interaction between the hole-transporting host material and the electron-transporting host material, specifically whether or not an exciplex is formed, can be determined by forming a monolayer film consisting only of the hole-transporting host material and the electron-transporting host material under the same conditions as for forming the emissive layer, measuring the emission spectrum (fluorescence, phosphorescence spectrum), and comparing the obtained emission spectrum with the emission spectra shown by the hole-transporting host material and the electron-transporting host material individually. This can be determined by whether the spectrum of the mixed film containing the hole-transporting host material and the electron-transporting host material shows an emission wavelength different from both the spectrum of the hole-transporting host material film and the spectrum of the electron-transporting host material film. Specifically, a difference of 10 nm or more in the peak wavelength of the spectra can be used as an indicator.

[0318] Specific examples of combinations of hole-transporting host materials and electron-transporting host materials that do not form excyplexes include the following combinations. In order to satisfy the physical properties of HOMO, LUMO, and excitation triplet energy mentioned above, for hole-transporting host materials, compounds having carbazole, dibenzofuran, dibenzothiophene, triarylamine, indelocarbazole, and benzooxazinophenoxazine as substructures are preferred, compounds having carbazole, dibenzofuran, and dibenzothiophene as substructures are more preferred, and compounds having carbazole as a substructure are even more preferred. Similarly, for electron-transporting host materials, compounds having pyridine, triazine, phosphine oxide, benzoflopyridine, and dibenzooxacillin as substructures are preferred, compounds having triazine, phosphine oxide, benzoflopyridine, and dibenzooxacillin as substructures are more preferred, and compounds having triazine are even more preferred.

[0319] More specifically, the hole-transporting host material is preferably selected from the group consisting of HH-1-1, HH-1-2, HH-1-4 to HH-1-12, HH-1-17, HH-1-18, HH-1-20 to HH-1-24, HH-1-82, HH-1-84 to HH-1-89, HH-1-91, HH-1-92 and HH-1-106 to HH-1-114, and the electron-transporting host material is preferably EH-1-1 to EH-1-4, EH It is preferable to select from the group consisting of EH-1-10, EH-1-21 to EH-1-25, EH-1-32, EH-1-33, EH-1-51 to EH-1-59, EH-1-61, EH-1-71, EH-1-72, EH-1-90, EH-1-100, EH-1-101, EH-1-104, EH-1-117, EH-1-120, EH-1-122, EH-1-123, and EH-1-127 to EH-1-130. Preferred combinations include compound HH-1-1 and compound EH-1-22, compound HH-1-1 and compound EH-1-23, compound HH-1-1 and compound EH-1-24, compound HH-1-2 and compound EH-1-22, compound HH-1-2 and compound EH-1-23, compound HH-1-2 and compound EH-1-24, or compound HH-1-1 and compound EH-1-128.

[0320] Specific examples of combinations of hole-transporting host materials and electron-transporting host materials that form an excyplex include the following combinations. In order to satisfy the physical properties of HOMO, LUMO, and excitation triplet energy, the hole-transporting host material is preferably a compound having carbazole, triarylamine, indelocarbazole, and benzoxazinophenoxazine as a substructure, more preferably a compound having triarylamine, indelocarbazole, and benzoxazinophenoxazine as a substructure, and even more preferably a compound having triarylamine as a substructure. Similarly, the electron-transporting host material is preferably a compound having pyridine, triazine, phosphine oxide, and benzoflopyridine as a substructure, more preferably a compound having triazine, phosphine oxide, benzoflopyridine, and dibenzoxacillin as a substructure, and even more preferably a compound having phosphine oxide and triazine.

[0321] More specifically, the hole-transporting host material is preferably selected from the group consisting of HH-1-1, HH-1-2, HH-1-11, HH-1-12, HH-1-17, HH-1-18, HH-1-23 and HH-1-24, and the electron-transporting host material is preferably EH-1-1 to EH-1-4, EH-1-21 to EH-1-25, EH- It is preferable to select from the group consisting of 1-51 to EH-1-57, EH-1-59, EH-1-66, EH-1-68, EH-1-90, EH-1-100, EH-1-101, EH-1-104, EH-1-117, EH-1-120, EH-1-122, EH-1-123, and EH-1-127 to EH-1-130. Preferred combinations include compound HH-1-1 and compound EH-1-21, compound HH-1-2 and compound EH-1-21, compound HH-1-12 and compound EH-1-117, compound HH-1-1 and compound EH-1-130, compound HH-1-33 and compound EH-1-117, compound HH-1-48 and compound EH-1-117, or compound HH-1-49 and compound EH-1-117.

[0322] For further information on specific combinations of hole-transporting and electron-transporting host materials, please refer to: Organic Electronics 66(2019)227-24, Advanced Functional Materials 25(2015)361-366, Advanced Materials 26(2014)4730-4734, ACS Applied Materials and Interfaces 8(2016)32984-32991, ACS Applied Materials and Interfaces 2016,8,9806-9810, ACS Applied Materials and Interfaces 2016,8,32984-32991, Journal of Materials Chemisty C,2018,6,8784-8792, Angewante Chemie International Edition.2018,57,12380-12384, Advanced Functional References can be found in Materials, 24, 2014, 3970, Advanced Materials, 26, 2014, 5684, and Synthetic Metals, 201, 2015, 49.

[0323] <Dopant Materials> The polycyclic aromatic compounds of the present invention having a structure containing the structural unit represented by formula (1) are preferably used as dopant materials. Other dopant materials that can be used include known compounds, and can be selected from a variety of materials depending on the desired emission color.Specifically, for example, condensed ring derivatives such as phenanthrene, anthracene, pyrene, tetracene, pentacene, perylene, naphthopyrene, dibenzopyrene, rubrene, and chrysene; benzoxazole derivatives; benzothiazole derivatives; benzimidazole derivatives; benzotriazole derivatives; oxazole derivatives; oxadiazole derivatives; thiazole derivatives; imidazole derivatives; thiadiazole derivatives; triazole derivatives; pyrazoline derivatives; stilbene derivatives; thiophene derivatives; and tetraphenylbutadiene. Derivatives, cyclopentadiene derivatives, bisstyryl derivatives such as bisstyrylanthracene derivatives and distyrylbenzene derivatives (Japanese Patent Publication No. 1-245087), bisstyrylarylene derivatives (Japanese Patent Publication No. 2-247278), diazindacene derivatives, furan derivatives, benzofuran derivatives, phenylisobenzofuran, dimesitylisobenzofuran, di(2-methylphenyl)isobenzofuran, di(2-trifluoromethylphenyl)isobenzofuran, phenylisobenzofuran, and other isobenzofuran derivatives. Coumarin derivatives such as dibenzofuran derivatives, 7-dialkylaminocoumarin derivatives, 7-piperidinocoumarin derivatives, 7-hydroxycoumarin derivatives, 7-methoxycoumarin derivatives, 7-acetoxycoumarin derivatives, 3-benzothiazolylcoumarin derivatives, 3-benzimidazolylcoumarin derivatives, 3-benzoxazolylcoumarin derivatives, dicyanomethylenepyran derivatives, dicyanomethylenethiopyran derivatives, polymethine derivatives, cyanine derivatives, oxobenzoanthracene derivatives, xanthene derivatives, and rhodamine derivatives. Examples include conductors, fluorescein derivatives, pyrylium derivatives, carbostyryl derivatives, acridine derivatives, oxazine derivatives, phenylene oxide derivatives, quinacridone derivatives, quinazoline derivatives, pyrrolopyridine derivatives, phlopyridine derivatives, 1,2,5-thiadiazolopyrene derivatives, pyromethene derivatives, perinone derivatives, pyrrolopyrrole derivatives, squarylium derivatives, biolantron derivatives, phenazine derivatives, acridone derivatives, deazaflavin derivatives, fluorene derivatives, and benzofluorene derivatives.

[0324] As the dopant material, it is also preferable to use a polycyclic aromatic compound containing boron as described in International Publication No. 2015 / 102118, International Publication No. 2020 / 162600, paragraphs 0097 to 0269 of Japanese Patent Publication No. 2021-077890, etc. The polycyclic aromatic compound having a boron atom may be a phosphor or a TADF material (thermally activated delayed phosphor). It is preferable that the polycyclic aromatic compound having a boron atom is a blue light-emitting compound.

[0325] Preferred examples of boron-containing polycyclic aromatic compounds include those represented by formulas (12), (13), or (14) below. [ka]

[0326] Rings A, B, C, and D are each independently a substituted or unsubstituted aryl ring or a substituted or unsubstituted heteroaryl ring. Y is B (boron), X 1 , X 2 , X 3 and X 4 Each of these is independently >O, >NR, >S, or >Se, where R in >NR is a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, or a substituted or unsubstituted alkyl, and R in >NR may be bonded to the A, B, C, and / or D rings by a linking group or a single bond. R 1 and R 2 Each of these is independently hydrogen, an alkyl group having 1 to 6 carbon atoms, an aryl group having 6 to 12 carbon atoms, a heteroaryl group having 2 to 15 carbon atoms, or a diarylamino group (where aryl is limited to aryl groups having 6 to 12 carbon atoms). Z 1 and Z 2 Each of these is independently one of the substituents selected from substituent group Z, and Z 1 Z may be bonded to the A ring by a linking group or a single bond, 2The C ring may be bonded to the C ring by a linking group or a single bond, and, At least one hydrogen atom in the compound represented by formula (12) may be replaced by a cyano, halogen, or deuterium.

[0327] The substituents and Z when an aryl ring or heteroaryl ring is substituted in rings A, B, C, and D of formula (12) 1 , Z 2 Examples include substituents selected from substituent group Z.

[0328] X in equation (12) 1 , X 2 , X 3 and X 4 Each of these is independently >O, >NR, >S, or >Se, where R in >NR is independently a C6-C12 aryl, a C2-C15 heteroaryl, a C3-C12 cycloalkyl, or a C1-C6 alkyl. In the compound represented by formula (12), from the viewpoint of high TADF properties, Z 1 and Z 2 It is preferable that the derivative is a substituted diphenylamino or a substituted N-carbazolyl, and more preferably a substituted diphenylamino. The substituted diphenylamino is preferably an unsubstituted diphenylamino or a diphenylamino having at least one C1-C4 alkyl group, and more preferably an unsubstituted diphenylamino or a diphenylamino having at least one methyl group at the m or o position relative to N. From the viewpoint of ease of synthesis and emission wavelength, the aryl or heteroaryl rings in the A, B, C, and D rings are Z 1 and Z 2 It is preferable that the other substituents are either not substituted or only alkyl groups having 1 to 6 carbon atoms, Z 1 and Z 2 It is more preferable that the other terms do not have substitutions. Examples of compounds represented by formula (12) are shown below.

[0329] [ka]

[0330] [ka]

[0331] [ka]

[0332] [ka]

[0333] In equations (13) and (14), A 11 Ring, A 21 Ring, A 31 Ring, B 11 Ring, B 21 Ring, C 11 Ring, and C 31 Each ring is independently a substituted or unsubstituted aryl ring or a substituted or unsubstituted heteroaryl ring. Y 11 , Y 21 , Y 31 It is B (boron), X 11 , X 12 , X 21 , X 22 , X 31 , and X 32 Each of these is independently >O, >NR, >S, or >Se, where R in >NR is a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, or a substituted or unsubstituted alkyl, and R in >NR is linked by a linking group or single bond to A 11 Ring, A 21 Ring, A 31 Ring, B 11 Ring, B 21 Ring, C 11 ring, and / or C 31It may be bonded to a ring, At least one hydrogen atom in the compounds represented by formulas (13) and (14) may be replaced by a cyano, halogen, or deuterium.

[0334] A in equations (13) and (14) 11 Ring, A 21 Ring, A 31 Ring, B 11 Ring, B 21 Ring, C 11 Ring, and C 31 In this case, substituents and Z when an aryl ring or heteroaryl ring is substituted. 1 , Z 2 Examples include substituents selected from substituent group Z.

[0335] X in equations (13) and (14) 11 , X 12 , X 21 , X 22 , X 31 , and X 32 Each of these is independently >O, >NR, >S, or >Se, where R in >NR is independently a C6-C12 aryl, a C2-C15 heteroaryl, a C3-C12 cycloalkyl, or a C1-C6 alkyl.

[0336] Examples of compounds represented by formula (13) or formula (14) are shown below. [ka]

[0337] [ka]

[0338] <Thermally activated delayed phosphors (assisting dopants)> A "thermally activated delayed phosphor" refers to a compound that absorbs thermal energy to undergo reverse intersystem crossing from the lowest excited triplet state to the lowest excited singlet state, and then radiatively deactivates from that lowest excited singlet state to emit delayed fluorescence. However, "thermally activated delayed fluorescence" also includes compounds that undergo a higher-order triplet state during the excitation process from the lowest excited triplet state to the lowest excited singlet state. For example, there is a paper by Monkman et al. from the University of Durham (NATURE COMMUNICATIONS, 7:13680, DOI: 10.1038 / ncomms13680), a paper by Hosokai et al. from the National Institute of Advanced Industrial Science and Technology (Hosokai et al., Sci. Adv. 2017;3: e1603282), a paper by Sato et al. from Kyoto University (Scientific Reports, 7:4820, DOI:10.1038 / s41598-017-05007-7), and a conference presentation by Sato et al. from Kyoto University (The 98th Annual Meeting of the Chemical Society of Japan, Presentation No.: 2I4-15, Mechanism of High-Efficiency Luminescence in Organic Electroluminescence Using DABNA as a Luminescent Molecule, Graduate School of Engineering, Kyoto University). In this invention, a target compound is determined to be a "thermally activated delayed phosphor" if a slow fluorescence component is observed when the fluorescence lifetime of a sample containing the target compound is measured at 300 K. Here, a slow fluorescence component refers to one with a fluorescence lifetime of 0.1 μsec or more. Fluorescence lifetime can be measured, for example, using a fluorescence lifetime analyzer (Hamamatsu Photonics, C11367-01).

[0339] The polycyclic aromatic compounds of the present invention, having a structure including the structural unit represented by formula (1), can function as emitting dopants, and the "thermally activated delayed phosphor" can function as an assisting dopant that assists the luminescence of the polycyclic aromatic compounds of the present invention. In the following explanation, organic electroluminescent devices that use a thermally activated delayed phosphor as an assisting dopant are sometimes referred to as "TAF devices" (TADF Assisting Fluorescence devices). In TAF devices, a "host compound" refers to a compound whose lowest excitation singlet energy level, determined from the short-wavelength shoulder of the fluorescence spectrum peak, is higher than that of the thermally activated delay phosphor (the second component) and the emitting dopant (the third component).

[0340] Figure 2 shows the energy level diagram of the light-emitting layer of a TAF device using a common fluorescent dopant as the emitting dopant (ED). In the figure, the energy level of the host ground state is E(1,G), the lowest excited singlet energy level obtained from the short-wavelength shoulder of the host fluorescence spectrum is E(1,S,Sh), the lowest excited triplet energy level obtained from the short-wavelength shoulder of the host phosphorescence spectrum is E(1,T,Sh), the energy level of the assisting dopant ground state is E(2,G), the lowest excited singlet energy level obtained from the short-wavelength shoulder of the assisting dopant fluorescence spectrum is E(2,S,Sh), and the phosphorescence of the assisting dopant is E(2,S,Sh). E(2,T,Sh) is the lowest excited triplet energy level determined from the short-wavelength shoulder of the spectrum, E(3,G) is the ground state energy level of the emitting dopant, E(3,S,Sh) is the lowest excited singlet energy level determined from the short-wavelength shoulder of the fluorescence spectrum of the emitting dopant, and E(3,T,Sh) is the lowest excited triplet energy level determined from the short-wavelength shoulder of the phosphorescence spectrum of the emitting dopant. Let h+ represent a hole, e- represent an electron, and FRET (Fluorescence Resonance Energy Transfer) be the fluorescence resonance energy transfer. In a TAF device, when a general fluorescent dopant is used as the emitting dopant (ED), the energy upconverted by the assisting dopant is transferred to the lowest excited singlet energy level E(3,S,Sh) of the emitting dopant and emits light. However, some of the lowest excited triplet energy E(2,T,Sh) on the assisting dopant moves to the lowest excited triplet energy level E(3,T,Sh) of the emitting dopant, or intersystem crossing occurs on the emitting dopant from the lowest excited singlet energy level E(3,S,Sh) to the lowest excited triplet energy level E(3,T,Sh), followed by thermal deactivation to the ground state E(3,G). Due to this pathway, some energy is not used for emission, resulting in wasted energy.

[0341] In contrast, the organic electroluminescent device of this embodiment can efficiently utilize the energy transferred from the assisting dopant to the emitting dopant for light emission, thereby achieving high luminescence efficiency. This is presumed to be due to the following light emission mechanism. Figure 3 shows the preferred energy relationships in the organic electroluminescent device of this embodiment. In the organic electroluminescent device of this embodiment, the compound having a boron atom as the emitting dopant has a high lowest excited triplet energy level E(3,T,Sh). Therefore, even if the lowest excited singlet energy upconverted by the assisting dopant undergoes intersystem crossing to the lowest excited triplet energy level E(3,T,Sh) by the emitting dopant, it is either upconverted on the emitting dopant or recovered to the lowest excited triplet energy level E(2,T,Sh) on the assisting dopant (thermally activated delayed phosphor). Thus, the generated excitation energy can be used for luminescence without waste. Furthermore, by separating the upconversion and luminescence functions into two types of molecules, each suited to its respective role, the residence time of high energy is reduced, and the burden on the compound is expected to decrease. In this embodiment, known host compounds can be used, for example, compounds having at least one of a carbazole ring and a furan ring, and among these, it is preferable to use a compound in which at least one of furanil and carbazolyl is bonded to at least one of arylene and heteroarylene. Specific examples include mCP and mCBP.

[0342] The lowest excited triplet energy level E(1,T,Sh), determined from the short-wavelength shoulder 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 emitter or assisting dopant having the highest lowest excited triplet energy level in the light-emitting layer, from the viewpoint of promoting TADF generation in the light-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 higher, more preferably 0.03 eV or higher, and even more preferably 0.1 eV or higher, compared to E(2,T,Sh) and E(3,T,Sh). Furthermore, a TADF-active compound may be used as the host compound.

[0343] The thermally activated delayed phosphor (TADF compound) used in TAF elements is preferably a donor-acceptor type thermally activated delayed phosphor (DA-type TADF compound), which is designed to enable efficient reverse intersystem crossing by localizing the HOMO (Highest Occupied Molecular Orbital) and LUMO (Lowest Unoccupied Molecular Orbital) within the molecule using electron-donating substituents called donors and electron-accepting substituents called acceptors.

[0344] Herein, in this specification, "electron-donating substituent" (donor) means substituents and substructures in which the HOMO orbital is localized in a thermally activated delayed phosphor molecule, and "electron-accepting substituent" (acceptor) means substituents and substructures in which the LUMO orbital is localized in a thermally activated delayed phosphor molecule.

[0345] Generally, thermally activated delayed phosphors using donors and acceptors have large spin-orbit coupling (SOC) and small exchange interaction between the HOMO and LUMO due to their structure, resulting in a ΔE STBecause of its small size, a very fast reverse intersystem crossover rate can be obtained. On the other hand, thermally activated delayed phosphors using donors and acceptors exhibit greater structural relaxation in the excited state (in some molecules, the stable structure differs between the ground state and the excited state; therefore, when a conversion from the ground state to the excited state occurs due to an external stimulus, the structure subsequently changes to the stable structure in the excited state), resulting in a broad emission spectrum. Therefore, using them as luminescent materials may reduce color purity. However, by using a thermally activated delayed phosphor using donors and acceptors as an assisting dopant along with an appropriate emitting dopant such as the polycyclic aromatic compound of the present invention, high color purity can be obtained.

[0346] As a thermally activated delayed phosphor in a TAF element, for example, a compound in which the donor and acceptor are directly or via a spacer can be used. As the electron-donating group (donor structure) and electron-accepting group (acceptor structure) used in the thermally activated delayed phosphor of the present invention, for example, the structures described in Chemistry of Materials, 2017, 29, 1946-1963 can be used. Examples of donor structures include carbazole, dimethylcarbazole, di-tert-butylcarbazole, dimethoxycarbazole, tetramethylcarbazole, benzofluorocarbazole, benzothienocarbazole, phenyldihydroindocarbazole, phenylbicarbazole, bicarbazole, tercarbazole, diphenylcarbazolylamine, tetraphenylcarbazolyldiamine, phenoxazine, dihydrophenazine, phenothiazine, dimethyldihydroacridine, diphenylamine, bis(tert-butylphenyl)amine, N1-(4-(diphenylamino)phenyl)-N4,N4-diphenylbenzene-1,4-diamine, dimethyltetraphenyldihydroacridinediamine, tetramethyl-dihydroindenoacridine, and diphenyl-dihydrodibenzoazacillin.Acceptor structures include sulfonyl dibenzene, benzophenone, phenylenebis(phenylmethanone), benzonitrile, isonicotinonitrile, phthalonitrile, isophthalonitrile, paraphthalonitrile, benzenetricarbonite, triazole, oxazole, thiadiazole, benzothiazole, benzobis(thiazole), benzoxazole, benzobis(oxazole), quinoline, benzimidazole, dibenzoquinoxaline, heptazaphenalene, thioxanthone dioxide, dimethylanthracenone, anthracendione, 5H-cyclopenta[1,2-b:5,4-b']dipyridine, fluorange carbonite, triphenyltriazine, pyrazinedicarbonite, pyrimidine, phenylpyrimidine, methylpyrimidine, pyridinedicarbonite, dibenzoquinoxalinedicarbonite, bis(phenylsulfonyl)benzene, dimethylthioxanthone dioxide, thianthrene tetraoxide, and tris(dimethylphenyl)borane. In particular, the compounds having thermally activated delayed fluorescence in the TAF element are preferably compounds having at least one selected from carbazole, phenoxazine, acridine, triazine, pyrimidine, pyrazine, thioxanthene, benzonitrile, phthalonitrile, isophthalonitrile, diphenylsulfone, triazole, oxadiazole, thiadiazole, and benzophenone as a substructure.

[0347] The compound used as the assisting dopant in the light-emitting layer of the TAF element is preferably a thermally activated delayed phosphor whose emission spectrum overlaps at least partially with the absorption peak of the emitting dopant.

[0348] <Phosphorescent materials (assisting dopant)> In the light-emitting layer, a phosphorescent material may be used as an assisting dopant. The phosphorescent material utilizes intramolecular spin-orbit interaction (heavy atom effect) by metal atoms to obtain light emission from the triplet state. For example, a luminescent metal complex can be used as such a phosphorescent material. Examples of luminescent metal complexes include compounds represented by the following formulas (B-1) and (B-2).

[0349] [ka]

[0350] In equation (B-1), M is at least one selected from the group consisting of Ir, Pt, Au, Eu, Ru, Re, Ag, and Cu, n is an integer from 1 to 3, and "XY" are each independent bidentate ligands. In equation (B-2), M is at least one selected from the group consisting of Pt, Re, and Cu, and "WXYZ" is a tetradentate ligand. In formula (B-1), from the viewpoint of efficiency and lifespan, M is preferably Ir and n is preferably 3. In equation (B-2), Pt is preferred for M from the viewpoint of efficiency and lifespan. In equation (B-1), ligand (XY) has at least one ligand selected from the group consisting of the following. In equation (B-2), ligand (WXYZ) has at least one ligand selected from the group consisting of the following as part of it.

[0351] [ka]

[0352] During the ceremony, --- is bonded to the central metal M, Y is independent of BR e , NR e PR e , O, S, Se, C=O, S=O, SO2, CR e R f , SiRe R f , or GeR e R f and Each aromatic carbon CH in the ring may be independently substituted with N. R e and R f These may optionally condense or bond to form a ring. R a , R b , R c , and R d Each of these can be substituted independently, either without substitution or with 1 to the maximum number of substitutions possible. R a , R b , R c , R d , R e , and R f However, each is independently hydrogen, deuterium, halide, alkyl, cycloalkyl, heteroalkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, aryl, heteroaryl, nitrile, isonitrile, sulfanyl, or a combination thereof. However, R a , R b , R c , and R d Any two adjacent substituents in may condense or bond to form a ring or a multidentate ligand.

[0353] Examples of compounds represented by formula (B-1) include Ir(ppy)3, Ir(ppy)2(acac), Ir(mppy)3, Ir(PPy)2(m-bppy), BtpIr(acac), Ir(btp)2(acac), Ir(2-phq)3, Hex-Ir(phq)3, Ir(fbi)2(acac), and fac-Tris(2-(3-p-xylyl)phenyl)pyridine. iridium(III), Eu(dbm)3(Phen), Ir(piq)3, Ir(piq)2(acac), Ir(Fliq)2(acac), Ir(Flq)2(acac), Ru(dtb-bpy)3·2(PF6), Ir(2-phq)3, Ir(BT)2(acac), Ir(DMP)3 , Ir(Mphq)3IR(phq)2tpy, fac-Ir(ppy)2Pc, Ir(dp)PQ2, Ir(Dpm)(Piq)2, Hex-Ir(piq)2(acac), Hex-Ir(piq)3, Ir(dmpq)3, Ir(dmpq)2(acac), FPQIrpic, etc.

[0354] Other compounds represented by formula (B-1) include, for example, compounds represented by any of the following formulas. [ka]

[0355] [ka]

[0356] [ka]

[0357] Alternatively, iridium complexes described in Japanese Patent Publication No. 2006-089398, Japanese Patent Publication No. 2006-080419, Japanese Patent Publication No. 2005-298483, Japanese Patent Publication No. 2005-097263, and Japanese Patent Publication No. 2004-111379, U.S. Patent Application Publication No. 2019 / 0051845, etc., or platinum complexes described in Advanced Materials, 26: 7116-7121, NPG Asia Materials 13, 53 (2021), Applied Physics Letters, 117, 253301 (2020), Light-Emitting Diode - An Outlook On the Empirical Features and Its Recent Technological Advancements, Chapter 5 may be used.

[0358] 2-1-6. Electron injection layer and electron transport layer in organic electroluminescent devices The electron injection layer 107 plays the 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 the 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 and mixing one or more types of electron transport / injection materials, or by a mixture of electron transport / injection materials and a polymer binder.

[0359] The electron injection and transport layer is responsible for injecting electrons from the cathode and transporting them. It is desirable for this layer to have high electron injection efficiency and to efficiently transport the injected electrons. To achieve this, it is preferable for the material to have high electron affinity, high electron mobility, excellent stability, and to be a material that does not easily generate trapping impurities during manufacturing and use. However, when considering the balance between hole and electron transport, if the main role is to efficiently prevent holes from the anode from flowing to the cathode side without recombining, then even if the electron transport capacity is not very high, the effect of improving luminescence efficiency will be equivalent to that of a material with high electron transport capacity. Therefore, the electron injection and transport layer in this embodiment may also include the function of a layer that can efficiently prevent the movement of holes.

[0360] The material used to form the electron transport layer 106 or electron injection layer 107 (electron transport material) can be arbitrarily selected from compounds conventionally used as electron transfer compounds in photoconductive materials, and known compounds used in the electron injection layer and electron transport layer of organic EL elements.

[0361] The 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 fused ring derivatives, and metal complexes having electron-accepting nitrogen. Specifically, examples include fused ring aromatic ring derivatives such as naphthalene and anthracene, styryl aromatic ring derivatives represented by 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 individually or in combination with different materials.

[0362] Furthermore, specific examples of other electron transfer compounds include pyridine derivatives, naphthalene derivatives, anthracene derivatives, phenanthroline derivatives, perinone derivatives, coumarin derivatives, naphthalimide derivatives, anthraquinone derivatives, diphenoquinone derivatives, diphenylquinone derivatives, perylene derivatives, oxadiazole derivatives (such as 1,3-bis[(4-t-butylphenyl)1,3,4-oxadiazolyl]phenylene), thiophene derivatives, triazole derivatives (such as N-naphthyl-2,5-diphenyl-1,3,4-triazole), thiadiazole derivatives, metal complexes of oxine derivatives, quinolinol-based metal complexes, quinoxaline derivatives, polymers of quinoxaline derivatives, benzazole compounds, gallium complexes, pyrazole derivatives, perfluorinated phenylene derivatives, triazine derivatives, and pyrazi Examples include derivatives of benzoquinols, benzoquinoline derivatives (such as 2,2'-bis(benzo[h]quinoline-2-yl)-9,9'-spirobifluorene), imidazopyridine derivatives, borane derivatives, benzimidazole derivatives (such as tris(N-phenylbenzimidazole-2-yl)benzene), benzoxazole derivatives, benzothiazole derivatives, quinoline derivatives, oligopyridine derivatives such as terpyridine, bipyridine derivatives, terpyridine derivatives (such as 1,3-bis(2,2':6',2"-terpyridine-4'-yl)benzene), naphthyridine derivatives (such as bis(1-naphthyl)-4-(1,8-naphthyridine-2-yl)phenylphosphine oxide), aldazine derivatives, carbazole derivatives, indole derivatives, phosphine oxide derivatives, and bisstyryl derivatives.

[0363] Furthermore, metal complexes containing electron-accepting nitrogen can also be used, such as quinolinol-based metal complexes, hydroxyazole complexes including hydroxyphenyl oxazole complexes, azomethine complexes, tropolone metal complexes, flavonol metal complexes, and benzoquinoline metal complexes.

[0364] The materials mentioned above can be used individually, but they can also be used in combination with other materials.

[0365] Among the materials mentioned above, borane derivatives, pyridine derivatives, fluorantene derivatives, BO derivatives, anthracene derivatives, benzofluorene derivatives, phosphine oxide derivatives, pyrimidine derivatives, arylnitrile derivatives, triazine derivatives, benzimidazole derivatives, phenanthroline derivatives, and quinolinol-based metal complexes are preferred.

[0366] The electron transport layer or electron injection layer may further contain a substance capable of reducing the material forming the electron transport layer or electron injection layer. This reducing substance can be any substance having a certain reducing property; for example, at least one selected from the group consisting of alkali metals, alkaline earth metals, rare earth metals, alkali metal oxides, alkali metal halides, alkaline earth metal oxides, alkaline earth metal halides, rare earth metal oxides, rare earth metal halides, alkali metal organic complexes, alkaline earth metal organic complexes, and rare earth metal organic complexes can be suitably used.

[0367] 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 (2.0-2.5 eV), or Ba (2.52 eV), with substances having a work function of 2.9 eV or less being particularly preferred. Of these, alkali metals K, Rb, or Cs are more preferred reducing substances, Rb or Cs are even more preferred, and Cs is the most preferred. These alkali metals have particularly high reducing ability, and their addition in relatively small amounts to materials forming electron transport layers or electron injection layers can improve the luminescence brightness and extend the lifespan of organic EL devices. Furthermore, combinations of two or more alkali metals are also preferred as reducing substances with a work function of 2.9 eV or less, and combinations including Cs, such as Cs and Na, Cs and K, Cs and Rb, or Cs, Na, and K, are particularly preferred. By including Cs, the reducing ability can be efficiently exhibited, and by adding it to the material forming the electron transport layer or electron injection layer, improvements in luminescence brightness and extended lifespan can be achieved in organic EL devices.

[0368] 2-1-7. Cathode in an Organic Electroluminescent Device The cathode 108 plays the role of injecting electrons into the light-emitting layer 105 via the electron injection layer 107 and the electron transport layer 106.

[0369] The material forming the cathode 108 is not particularly limited as long as it can efficiently inject electrons into the organic layer, but the same material as the material forming the anode 102 can be used. Among these, metals such as tin, indium, calcium, aluminum, silver, copper, nickel, chromium, gold, platinum, iron, zinc, lithium, sodium, potassium, cesium, and magnesium, or their alloys (such as magnesium-silver alloys, magnesium-indium alloys, and aluminum-lithium alloys such as lithium fluoride / aluminum), are preferred. To increase electron injection efficiency and improve device characteristics, alloys containing lithium, sodium, potassium, cesium, calcium, magnesium, or these low work function metals are effective. However, these low work function metals are generally unstable in the atmosphere. To improve this, for example, a method is known in which the organic layer is doped with trace amounts of lithium, cesium, or magnesium to use electrodes with high stability. Other dopants that can be used include inorganic salts such as lithium fluoride, cesium fluoride, lithium oxide, and cesium oxide. However, they are not limited to these.

[0370] Furthermore, for electrode protection, it is preferable to laminate metals such as platinum, gold, silver, copper, iron, tin, aluminum, and indium, or alloys using these metals, as well as inorganic materials such as silica, titania, and silicon nitride, polyvinyl alcohol, vinyl chloride, and hydrocarbon polymer compounds. The method for fabricating these electrodes is not particularly limited as long as conductivity can be achieved, such as resistance heating, electron beam deposition, sputtering, ion plating, and coating.

[0371] 2-1-8. Method for fabricating organic electroluminescent devices Each layer constituting an organic EL element can be formed by thinning the material to be composed of each layer using methods such as vapor deposition, resistance heating deposition, electron beam deposition, sputtering, molecular stacking, printing, spin coating or casting, or coating. There are no particular limitations on the thickness of each layer formed in this way, and it can be set appropriately according to the properties of the material, but it is usually in the range of 2 nm to 5000 nm. The thickness can usually be measured with a quartz crystal oscillating film thickness measuring device. When thinning using vapor deposition, the deposition conditions vary depending on the type of material, the desired crystal structure and association structure of the film, etc. Generally, the deposition conditions are a boat heating temperature of +50 to +400°C and a vacuum of 10°C. -6 ~10 -3 It is preferable to appropriately set the Pa, deposition rate to 0.01 to 50 nm / second, substrate temperature to -150 to +300°C, and film thickness to 2 nm to 5 μm.

[0372] When applying a DC voltage to the organic EL element obtained in this way, the voltage should be applied with the anode as + and the cathode as -. When a voltage of approximately 2 to 40V is applied, light emission can be observed from the transparent or semi-transparent electrode side (anode or cathode, or both). Furthermore, this organic EL element will also emit light when a pulsed current or alternating current is applied. The waveform of the applied AC current can be arbitrary.

[0373] Next, as an example of a method for fabricating an organic EL device, we will describe a method for fabricating an organic EL device consisting of an anode, a hole injection layer, a hole transport layer, an emissive layer made of a host material and a dopant material, an electron transport layer, an electron injection layer, and a cathode.

[0374] <Vapor deposition method> An anode is fabricated by forming a thin film of anode material on a suitable substrate using a vapor deposition method, and then thin films of a hole injection layer and a hole transport layer are formed on this anode. A host material and a dopant material are co-deposited on this to form a thin film that serves as the light-emitting layer, and then an electron transport layer and an electron injection layer are formed on this light-emitting layer. Finally, a thin film made of cathode material is formed using a vapor deposition method to form the cathode, thereby obtaining the desired organic EL element. In addition, in the fabrication of the organic EL element described above, it is also possible to reverse the fabrication order and fabricate the cathode, electron injection layer, electron transport layer, light-emitting layer, hole transport layer, hole injection layer, and anode in that order.

[0375] <Wet film formation method> The wet film deposition method is carried out by preparing a liquid organic layer-forming composition containing low-molecular-weight compounds capable of forming each organic layer of an organic EL device. If a suitable organic solvent for dissolving these low-molecular-weight compounds is not available, the organic layer-forming composition may be prepared from polymer compounds obtained by polymerizing the low-molecular-weight compounds with other monomers or main-chain polymers that have solubility properties, by substituting reactive substituents on the low-molecular-weight compounds.

[0376] Wet film formation generally involves a coating step of applying an organic layer-forming composition to a substrate and a drying step of removing the solvent from the applied organic layer-forming composition to form a coating film. If the polymer compound has a crosslinkable substituent (also called a crosslinkable polymer compound), this drying step further crosslinks it to form a polymer crosslinked body. Depending on the coating step, methods using a spin coater are called spin coating, methods using a slit coater are called slit coating, methods using a plate are called gravure, offset, reverse offset, and flexographic printing, methods using an inkjet printer are called inkjet printing, and methods spraying in a mist are called spraying. Drying methods include air drying, heating, and vacuum drying. The drying step may be performed only once, or multiple times using different methods and conditions. In addition, different methods may be used in combination, such as firing under reduced pressure.

[0377] Wet deposition is a method of forming thin films using a solution, such as certain printing methods (inkjet printing), spin coating or casting, and coating methods. Unlike vacuum deposition, wet deposition does not require expensive vacuum deposition equipment and can be performed under atmospheric pressure. In addition, wet deposition allows for large-area deposition and continuous production, leading to reduced manufacturing costs.

[0378] On the other hand, compared to vacuum deposition, wet deposition can be difficult for layering. When fabricating layered films using wet deposition, it is necessary to prevent the upper layer's composition from dissolving the lower layer, and techniques such as controlled solubility of the composition, crosslinking of the lower layer, and orthogonal solvents (solvents that do not mix with each other) are employed. However, even with these techniques, it can be difficult to use wet deposition for coating all films.

[0379] Therefore, a common approach is to fabricate organic EL elements using a wet deposition method for only a few layers, and a vacuum deposition method for the rest.

[0380] For example, the procedure for fabricating an organic EL element by partially applying a wet film deposition method is shown below. (Step 1) Film deposition by vacuum deposition of the anode (Step 2) Wet deposition of a hole injection layer-forming composition containing hole injection layer material. (Step 3) Wet deposition of a hole transport layer forming composition containing a hole transport layer material. (Step 4) Wet deposition of a light-emitting layer-forming composition containing a host material and a dopant material. (Step 5) Deposition of electron transport layer by vacuum deposition (Step 6) Deposition of electron injection layer by vacuum deposition (Step 7) Deposition of film by vacuum deposition of cathode By following this procedure, an organic EL element is obtained consisting of an anode, a hole injection layer, a hole transport layer, an emissive layer made of a host material and a dopant material, an electron transport layer, an electron injection layer, and a cathode. Of course, the electron transport layer and electron injection layer may also be formed by a wet deposition method using a layer-forming composition containing the electron transport layer material and the electron injection layer material, respectively. In this case, it is preferable to use means to prevent the dissolution of the lower light-emitting layer, or to deposit the film from the cathode side, in the opposite direction to the procedure described above.

[0381] <Other film formation methods> Laser heating and deposition (LITI) can be used to form organic layer-forming compositions. LITI is a method of heating and depositing a compound attached to a substrate using a laser, and organic layer-forming compositions can be used as the material coated onto the substrate.

[0382] <Optional steps> Appropriate processing steps, cleaning steps, and drying steps may be appropriately inserted before and after each film formation step. Examples of processing steps include exposure treatment, plasma surface treatment, ultrasonic treatment, ozone treatment, cleaning treatment using an appropriate solvent, and heat treatment. Furthermore, a series of steps for creating a bank may also be included.

[0383] Photolithography can be used to create the resist bank. Positive and negative resist materials can be used as the resist bank material for photolithography. Patternable printing methods such as inkjet, gravure offset printing, reverse offset printing, and screen printing can also be used. Permanent resist materials can also be used in these cases.

[0384] <Compositions for forming organic layers used in wet film deposition methods> The organic layer-forming composition is obtained by dissolving a low-molecular-weight compound capable of forming each organic layer of an organic EL element, or a high-molecular-weight compound obtained by polymerizing the low-molecular-weight compound, in an organic solvent. For example, the light-emitting layer-forming composition contains, as a first component, at least one polycyclic aromatic compound (or its high-molecular-weight compound) which is a dopant material, as a second component, at least one host material, and as a third component, at least one organic solvent. The first component functions as a dopant component of the light-emitting layer obtained from the composition, and the second component functions as a host component of the light-emitting layer. The third component functions as a solvent that dissolves the first and second components in the composition, and during application, the controlled evaporation rate of the third component itself provides a smooth and uniform surface shape.

[0385] <organic solvents> The organic layer-forming composition contains at least one organic solvent. By controlling the evaporation rate of the organic solvent during film formation, the film-forming properties, the presence or absence of defects in the coating film, surface roughness, and smoothness can be controlled and improved. Furthermore, when forming films using an inkjet method, the meniscus stability at the pinholes of the inkjet head can be controlled, thereby controlling and improving ejection performance. In addition, by controlling the drying rate of the film and the orientation of derivative molecules, the electrical properties, luminescence properties, efficiency, and lifespan of an organic EL element having an organic layer obtained from the organic layer-forming composition can be improved.

[0386] The organic solvent is removed from the coating film after film formation by drying processes such as vacuum, reduced pressure, or heating. When heating is performed, it is preferable to heat at a temperature of at least one solute's glass transition temperature (Tg) + 30°C or lower from the viewpoint of improving coating film formation. Furthermore, from the viewpoint of reducing residual solvent, it is preferable to heat at a temperature of at least one solute's glass transition temperature (Tg) - 30°C or higher. Even if the heating temperature is lower than the boiling point of the organic solvent, the organic solvent is sufficiently removed because the film is thin. In addition, drying may be performed multiple times at different temperatures, or multiple drying methods may be used in combination.

[0387] (2) Specific examples of organic solvents Organic solvents used in compositions for forming organic layers include, but are not limited to, alkylbenzene solvents, phenyl ether solvents, alkyl ether solvents, cyclic ketone solvents, aliphatic ketone solvents, monocyclic ketone solvents, solvents having a diester skeleton, and fluorine-containing solvents. Furthermore, solvents may be used individually or in mixtures.

[0388] <Optional ingredients> The organic layer-forming composition may contain optional components as long as they do not impair its properties. Examples of optional components include binders and surfactants.

[0389] <Composition and physical properties of organic layer-forming compositions> The content of each component in the organic layer-forming composition is determined considering the good solubility, storage stability, and film-forming properties of each component in the organic layer-forming composition, as well as the good film quality of the coating obtained from the organic layer-forming composition, good ejection performance when using an inkjet method, and good electrical properties, luminescence properties, efficiency, and lifespan of the organic EL element having an organic layer made using the composition.

[0390] The organic layer-forming composition can be produced by appropriately selecting and performing stirring, mixing, heating, cooling, dissolving, dispersion, etc., on the above-mentioned components using known methods. Furthermore, after preparation, filtration, degassing (also called degassing), ion exchange treatment, and inert gas replacement / sealing treatment may be performed as appropriate.

[0391] 2-1-9. Application Examples of Organic Electroluminescent Devices This invention can also be applied to display devices equipped with organic EL elements or lighting devices equipped with organic EL elements. A display device or lighting device equipped with an organic EL element can be manufactured by known methods, such as connecting the organic EL element according to this embodiment with a known driving device, and can be driven using known driving methods such as DC driving, pulse driving, or AC driving as appropriate.

[0392] Examples of display devices include panel displays such as color flat panel displays and flexible displays such as flexible color organic electroluminescent (EL) displays (see, for example, Japanese Patent Publication No. 10-335066, Japanese Patent Publication No. 2003-321546, and Japanese Patent Publication No. 2004-281086). Examples of display methods include matrix and segment displays. Matrix and segment displays may coexist on the same panel.

[0393] In a matrix display, pixels for display are arranged two-dimensionally, such as in a grid or mosaic pattern, and characters or images are displayed using a collection of pixels. The shape and size of the pixels are determined by the application. For example, for displaying images and characters on personal computers, monitors, and televisions, square pixels with sides of 300 μm or less are usually used, while for large displays such as display panels, pixels with sides on the order of millimeters are used. For monochrome displays, pixels of the same color can be arranged, but for color displays, red, green, and blue pixels are arranged side by side. In this case, there are typically delta type and stripe type displays. The matrix can be driven by either a line-sequential drive method or an active matrix. Line-sequential drive has the advantage of a simpler structure, but considering the operating characteristics, the active matrix may be superior in some cases, so it is necessary to choose the appropriate method depending on the application.

[0394] In segment-based displays, a pattern is formed to display predetermined information, and a designated area is illuminated. Examples include time and temperature displays in digital clocks and thermometers, operating status displays in audio equipment and induction cooktops, and panel displays in automobiles.

[0395] Examples of lighting devices include lighting devices such as indoor lighting and backlights for liquid crystal displays (see, for example, Japanese Patent Publication No. 2003-257621, Japanese Patent Publication No. 2003-277741, and Japanese Patent Publication No. 2004-119211). Backlights are mainly used to improve the visibility of non-self-illuminating display devices and are used in liquid crystal displays, clocks, audio equipment, automobile panels, display boards, and signs. In particular, for liquid crystal displays, especially backlights for personal computers where miniaturization is a challenge, conventional methods consist of fluorescent lamps and light guide plates, making miniaturization difficult. Therefore, the backlight using the light-emitting element according to this embodiment is characterized by being thin and lightweight.

[0396] 2-2. Other Organic Devices The polycyclic aromatic compounds according to the present invention can be used not only in the organic field-light-emitting device described above, but also in the fabrication of organic field-effect transistors or organic thin-film solar cells. [Examples]

[0397] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0398] <Synthesis of Compounds> Synthesis example (1-1): Synthesis of compound (1-1) [ka]

[0399] 1st process Under a nitrogen atmosphere, compound (T-1) (5.3g), compound (T-2) (3.9g) (synthesized according to the method described in International Publication No. 2019 / 114611), tert-butoxysodium (2.9g), dichlorobis[di-t-butyl(4-dimethylaminophenyl)phosphino]palladium(II) (Pd-132, 0.35g) as a palladium catalyst, and xylene (100ml) were placed in a reactor and heated under reflux for 5 hours. After the reaction mixture was cooled to room temperature, the aqueous layer was extracted with toluene. The combined organic layers were washed with water and dried over anhydrous magnesium sulfate. This solution was concentrated under reduced pressure, and the residue was purified by silica gel chromatography (toluene) to obtain compound (T-3) (5.5g).

[0400] 2nd process To a flask containing compound (T-3) (0.9 g) and tert-butylbenzene (7.0 ml), 1.5 ml of 1.6 M tert-butyllithium pentane solution was added under a nitrogen atmosphere at -30°C. After the addition was complete, the temperature was raised to 60°C and stirred for 2 hours, then components with a lower boiling point than tert-butylbenzene were removed by distillation under reduced pressure. The mixture was cooled to -30°C, boron tribromide (0.61 g) was added, and the temperature was raised to room temperature and stirred for 0.5 hours. Then, it was cooled again to 0°C, N,N-diisopropylethylamine (0.42 ml) was added, and the mixture was stirred at room temperature until the exothermic reaction subsided, then the temperature was raised to 120°C and heated and stirred for 3 hours. The reaction mixture was cooled to room temperature, and then liquid-liquid was added to aqueous sodium acetate solution cooled in an ice bath, followed by heptane. Next, the compound was purified using a silica gel short-pass column (eluent: toluene), the solvent was removed by vacuum distillation, and the resulting solid was dissolved in toluene. Heptane was added to reprecipitate the compound, which was represented by formula (1-1). MALDI-TOF-MS(M + ) = 737.49

[0401] Synthesis examples (1-2): Synthesis of compound (1-1) [ka]

[0402] 1st process Under a nitrogen atmosphere, compound (T-9) (5.6g), compound (T-10) (3.4g), tert-butoxysodium (2.9g), dichlorobis[di-t-butyl(4-dimethylaminophenyl)phosphino]palladium(II) (Pd-132, 0.35g) as a palladium catalyst, and xylene (100ml) were placed in a reactor and heated under reflux for 5 hours. After the reaction mixture was cooled to room temperature, the aqueous layer was extracted with toluene. The combined organic layers were washed with water and dried over anhydrous magnesium sulfate. This solution was concentrated under reduced pressure, and the residue was purified by silica gel chromatography (toluene) to obtain compound (T-3) (5.9g).

[0403] The second step is the same as in synthesis example (1-1). MALDI-TOF-MS(M + ) = 737.49

[0404] Synthesis example (2): Synthesis of compounds (1-24) [ka]

[0405] The compound was synthesized using a method similar to the second step of synthesis example (1-1). MALDI-TOF-MS(M + ) = 793.46

[0406] Synthesis example (3): Synthesis of compounds (1-31) [ka]

[0407] The compound was synthesized using a method similar to the second step of synthesis example (1-1). MALDI-TOF-MS(M + ) = 774.48

[0408] Synthesis example (4): Synthesis of compounds (1-34) [ka]

[0409] The compound was synthesized using a method similar to the second step of synthesis example (1-1). MALDI-TOF-MS(M + ) = 873.33

[0410] Synthesis example (5): Synthesis of compounds (1-42) [ka]

[0411] The compound was synthesized using a method similar to the second step of synthesis example (1-1). MALDI-TOF-MS(M + ) = 735.47

[0412] Synthesis example (6): Synthesis of compounds (1-48) [ka]

[0413] It was synthesized using a method similar to the second step of example (1-1). MALDI-TOF-MS(M + ) = 713.49

[0414] Synthesis example (7): Synthesis of compounds (1-51) [ka]

[0415] To a flask containing compound (T-4) (0.7 g) and tert-butylbenzene (7.0 ml), 1.5 ml of 1.6 M tert-butyllithium pentane solution was added under a nitrogen atmosphere at -30°C. After the addition was complete, the temperature was raised to 60°C and stirred for 2 hours, then components with a lower boiling point than tert-butylbenzene were removed by distillation under reduced pressure. The mixture was cooled to -30°C, boron tribromide (0.61 g) was added, and the temperature was raised to room temperature and stirred for 0.5 hours. Then, it was cooled again to 0°C, N,N-diisopropylethylamine (0.42 ml) was added, and the mixture was stirred at room temperature until the exothermic reaction subsided, then the temperature was raised to 120°C and heated and stirred for 3 hours. The reaction mixture was cooled to room temperature, and then liquid-liquid was added to aqueous sodium acetate solution cooled in an ice bath, followed by heptane. Next, after purification using a silica gel short-pass column (eluent: toluene), the solvent was removed by vacuum distillation, and the resulting solid was dissolved in toluene. Heptane was added to reprecipitate the compound represented by formula (1-51). MALDI-TOF-MS(M + ) = 1133.45

[0416] Synthesis example (8): Synthesis of compounds (1-52) [ka]

[0417] (T-4) was replaced with (T-9), and the synthesis was performed according to synthesis example (7). MALDI-TOF-MS(M + ) = 1170.45

[0418] Synthesis example (9): Synthesis of compounds (2-3) [ka]

[0419] 1st process Compound (T-5) was synthesized using a method similar to the second step of synthesis example (1-1).

[0420] 2nd process Under a nitrogen atmosphere, compound (T-5) (5.3g), compound (T-6) (4.1g), tert-butoxysodium (2.9g), Pd-132 (0.35g), and xylene (100ml) were placed in a reactor and heated under reflux for 5 hours. After the reaction mixture was cooled to room temperature, the aqueous layer was extracted with toluene. The combined organic layers were washed with water and dried over anhydrous magnesium sulfate. This solution was concentrated under reduced pressure, and the residue was purified by silica gel chromatography (toluene) to obtain compound (2-3) (4.8g). MALDI-TOF-MS(M + ) = 737.49

[0421] Synthesis example (10): Synthesis of compounds (2-4) [ka]

[0422] It was synthesized using a method similar to the second step of synthesis example (9). MALDI-TOF-MS(M + ) = 890.31

[0423] Synthesis example (11): Synthesis of compounds (2-9) [ka]

[0424] It was synthesized using a method similar to the second step of synthesis example (9). MALDI-TOF-MS(M + ) = 917.31

[0425] Synthesis example (12): Synthesis of compound (1-201) [ka]

[0426] The compound was synthesized using a method similar to the second step of synthesis example (1-1). MALDI-TOF-MS(M + ) = 795.47

[0427] Synthesis example (13): Synthesis of compound (1-202) [ka]

[0428] The compound was synthesized using a method similar to the second step of synthesis example (1-1). MALDI-TOF-MS(M + ) = 1096.66

[0429] Synthesis example (14): Synthesis of compound (1-203) [ka]

[0430] The compound was synthesized using a method similar to the second step of synthesis example (1-1). MALDI-TOF-MS(M + ) = 1082.60

[0431] Synthesis example (15): Synthesis of compounds (1-204) [ka]

[0432] The compound was synthesized using a method similar to the second step of synthesis example (1-1). MALDI-TOF-MS(M + ) = 965.64

[0433] Synthesis example (16): Synthesis of compounds (1-205) [ka]

[0434] The compound was synthesized using a method similar to the second step of synthesis example (1-1). MALDI-TOF-MS(M + ) = 927.57

[0435] Synthesis example (17): Synthesis of compounds (1-206) [ka]

[0436] The compound was synthesized using a method similar to the second step of synthesis example (1-1). MALDI-TOF-MS(M + ) = 987.62

[0437] Synthesis example (18): Synthesis of compound (1-207) [ka]

[0438] The compound was synthesized using a method similar to the second step of synthesis example (1-1). MALDI-TOF-MS(M + ) = 963.53

[0439] Synthesis example (19): Synthesis of compounds (1-208) [ka]

[0440] The compound was synthesized using a method similar to the second step of synthesis example (1-1). MALDI-TOF-MS(M + ) = 915.47

[0441] Synthesis example (20): Synthesis of compounds (1-209) [ka]

[0442] The compound was synthesized using a method similar to the second step of synthesis example (1-1). MALDI-TOF-MS(M + ) = 791.44

[0443] Synthesis example (21): Synthesis of compounds (1-210) [ka]

[0444] The compound was synthesized using a method similar to the second step of synthesis example (1-1). MALDI-TOF-MS(M + ) = 829.50

[0445] Synthesis example (22): Synthesis of compound (1-211) [ka]

[0446] The compound was synthesized using a method similar to the second step of synthesis example (1-1). MALDI-TOF-MS(M + ) = 733.42

[0447] Synthesis example (23): Synthesis of compound (1-212) [ka]

[0448] The compound was synthesized using a method similar to the second step of synthesis example (1-1). MALDI-TOF-MS(M + ) = 813.43

[0449] Synthesis example (24): Synthesis of compound (1-213) [ka]

[0450] The compound was synthesized using a method similar to the second step of synthesis example (1-1). MALDI-TOF-MS(M + ) = 895.60

[0451] Synthesis example (25): Synthesis of compound (1-214) [ka]

[0452] The compound was synthesized using a method similar to the second step of synthesis example (1-1). MALDI-TOF-MS(M + ) = 867.57

[0453] Synthesis example (26): Synthesis of compound (1-215) [ka]

[0454] The compound was synthesized using a method similar to the second step of synthesis example (1-1). MALDI-TOF-MS(M + ) = 959.59

[0455] Synthesis example (27): Synthesis of compound (1-216) [ka]

[0456] The compound was synthesized using a method similar to the second step of synthesis example (1-1). MALDI-TOF-MS(M + ) = 999.66

[0457] By appropriately changing the raw material compounds, other compounds of the present invention can be synthesized by a method similar to the synthesis example described above.

[0458] <Fabrication and Evaluation of Organic EL Devices> Next, we will describe the fabrication and evaluation of organic EL elements using the polycyclic aromatic compounds of the present invention.

[0459] Fabrication of organic EL elements The following organic EL elements were manufactured using the polycyclic aromatic compound of the present invention.

[0460] <Examples 1-1 to 1-22, and Comparative Example 1> Table 1 below shows the material composition of each layer in the organic EL elements of Examples 1-1 to 1-22 and Comparative Example 1. [Table 1] TIFF0007913706000152.tif71170

[0461] In Table 1, "HI" is N 4 ,N 4' -diphenyl-N 4 ,N 4' -Bis(9-phenyl-9H-carbazole-3-yl)-[1,1'-biphenyl]-4,4'-diamine, "HAT-CN" is 1,4,5,8,9,12-hexaazatriphenylenehexacarbonnitrile, "HT-1" is N-[1,1'-biphenyl]-4-yl-9,9-dimethyl-N-[4-(9-phenyl-9H-carbazole-3-yl)phenyl]-9H-fluoren-2-amine, and "HT-2" is N,N-bis(4-(dibenzo[b,d]furan-4-yl) The compound is phenyl)-[1,1':4',1"-terphenyl]-4-amine, where "BH" is 2-(10-phenylanthracene-9-yl)dibenzo[b,d]furan, "ET-1" is 9,9'-[(5-(6-(1,1'-biphenyl)-4-yl)-2-phenylpyrimidine-4-yl)-1,3-phenylene]bis(9H-carbazole), and "ET-2" is 2-ethyl-1-(4-(10-phenylanthracene-9-yl)phenyl)-1H-benzo[d]imidazole. The chemical structures of "Liq" and comparative compound (1) (compound described in International Publication No. 2015 / 102118) are shown below.

[0462] [ka]

[0463] [Example 1-1] A 26mm x 28mm x 0.7mm glass substrate (manufactured by OptoScience Co., Ltd.), which had been polished to 150nm by sputtering an ITO film to a thickness of 180nm, was used as the transparent support substrate. This transparent support substrate was fixed to the substrate holder of a commercially available deposition apparatus (manufactured by Showa Vacuum Co., Ltd.), and molybdenum deposition boats containing HI, HAT-CN, HT-1, HT-2, BH, compound (1-1), ET-1, and ET-2, respectively, and aluminum nitride deposition boats containing Liq, LiF, and aluminum, respectively, were attached.

[0464] The following layers are sequentially formed on the ITO film of the transparent support substrate. The vacuum chamber is 5 × 10 -4 The pressure was reduced to Pa. First, HI was heated and deposited to a thickness of 40 nm. Next, HAT-CN was heated and deposited to a thickness of 5 nm. Then, HT-1 was heated and deposited to a thickness of 45 nm. Next, HT-2 was heated and deposited to a thickness of 10 nm to form a hole layer consisting of four layers. Next, BH and compound (1-1) were heated simultaneously and deposited to a thickness of 25 nm to form an emissive layer. The deposition rate was adjusted so that the mass ratio of BH to compound (1-1) was approximately 97:3. Furthermore, ET-1 was heated and deposited to a thickness of 5 nm. Next, ET-2 and Liq were heated simultaneously and deposited to a thickness of 25 nm to form a two-layer electron layer. The deposition rate was adjusted so that the mass ratio of ET-2 to Liq was approximately 50:50. The deposition rate for each layer was 0.01 to 1 nm / second. Subsequently, LiF was heated and deposited at a deposition rate of 0.01 to 0.1 nm / second to achieve a film thickness of 1 nm. Then, aluminum was heated and deposited to a film thickness of 100 nm to form a cathode, thereby obtaining an organic EL device.

[0465] [Examples 1-2 to 1-22, Comparative Example 1] An organic EL device was obtained in the same manner as in Example 1-1, except that the compound listed in Table 1 was used instead of compound (1-1).

[0466] Evaluation items and evaluation methods The evaluation items include driving voltage (V), emission wavelength (nm), CIE chromaticity (x,y), external quantum efficiency (%), maximum wavelength (nm) and full width at half maximum (nm) of the emission spectrum. These evaluation items are, for example, 1000 cd / m². 2 The value at the time of emission can be used.

[0467] The quantum efficiency of a light-emitting device has two components: internal quantum efficiency and external quantum efficiency. Internal quantum efficiency indicates the proportion of external energy injected into the light-emitting layer of the device as electrons (or holes) that is purely converted into photons. External quantum efficiency, on the other hand, is calculated based on the amount of these photons emitted to the outside of the device. Since some of the photons generated in the light-emitting layer are absorbed or reflected within the device and not emitted to the outside, the external quantum efficiency is lower than the internal quantum efficiency.

[0468] The measurement method for spectral radiance (emission spectrum) and external quantum efficiency is as follows: Using an Advantest R6144 voltage / current generator, the device's radiance was 1000 cd / m². 2 A voltage is applied to cause the element to emit light. A TOPCON SR-3AR spectroradiometer is used to measure the spectral radiance in the visible light region from a direction perpendicular to the light-emitting surface. Assuming the light-emitting surface is a perfectly diffusive surface, the number of photons at each wavelength is obtained by dividing the measured spectral radiance value of each wavelength component by the wavelength energy and multiplying by π. Next, the number of photons is integrated across the entire observed wavelength range to obtain the total number of photons emitted from the element. The number of carriers injected into the element is obtained by dividing the applied current value by the elementary charge, and the external quantum efficiency is obtained by dividing the total number of photons emitted from the element by the number of carriers injected into the element. The full width at half maximum of the emission spectrum is determined as the width between the wavelengths above and below the maximum emission wavelength where the intensity is 50%.

[0469] For the organic EL elements of Examples 1-1 to 1-22 and Comparative Example 1, a DC voltage was applied with the ITO electrode as the anode and the LiF / aluminum electrode as the cathode, resulting in a reading of 1000 cd / m². 2 We measured the characteristics of the light emission and also measured the time it took to maintain a brightness of 90% or more of the initial brightness. The results are shown in Table 2.

[0470] [Table 2]

[0471] Examples 1-1 to 1-22 showed shorter peak wavelengths and higher efficiency compared to Comparative Example 1.

[0472] <Examples 2-4 and Comparative Examples 2-4> Organic EL elements were fabricated according to Examples 2-4 and Comparative Examples 2-4 (each example and comparative example shown in Table 3), achieving a brightness of 1000 cd / m². 2 In this context, external quantum efficiency and LT50 (initial brightness 1000 cd / m²) 2 500 cd / m² when continuously driven at the current density in the given location. 2 The time it took to reach that state was measured. In the following tables, "Host 1" corresponds to a hole-transporting host material, and "Host 2" corresponds to an electron-transporting host material.

[0473] [Table 3]

[0474] [Comparative Example 2-1] A 26mm x 28mm x 0.7mm glass substrate (manufactured by OptoScience Co., Ltd.), which had been polished to 50nm by sputtering an ITO film to a thickness of 200nm, was used as a transparent support substrate. This transparent support substrate was fixed to the substrate holder of a commercially available deposition apparatus (manufactured by Showa Vacuum Co., Ltd.), and molybdenum deposition boats containing HAT-CN, HTL-1, TcTa, ETL-1, and ET7, respectively, and tungsten deposition boats containing LiF and aluminum, respectively, were attached.

[0475] The following layers were sequentially formed on the ITO film of the transparent support substrate. The vacuum chamber was 5 × 10 -4 The pressure was reduced to Pa, and first, HAT-CN was heated and deposited to a thickness of 5 nm to form a hole injection layer. Next, HTL-1 was heated and deposited to a thickness of 90 nm to form hole transport layer 1, and then TcTa was heated and deposited to a thickness of 10 nm to form hole transport layer 2. Next, ETL-1 and new-DABNA were heated simultaneously and deposited to a thickness of 20 nm to form an emissive layer. The deposition rate was adjusted so that the weight ratio of ETL-1 to new-DABNA was approximately 99:1. Next, ETL-1 was heated and deposited to a thickness of 20 nm to form electron transport layer 1, and then ET7 was heated and deposited to a thickness of 10 nm to form electron transport layer 2. The deposition rate for each layer was 0.01 to 1 nm / second. After that, LiF was heated and deposited at a deposition rate of 0.01 to 0.1 nm / second to a thickness of 1 nm, and then aluminum was heated and deposited to a thickness of 100 nm to form a cathode, thereby obtaining an organic EL device. At this time, the aluminum deposition rate was adjusted to 1-10 nm / second.

[0476] The chemical structures in Table 3 and Comparative Example 2-1 are shown below.

[0477] [ka]

[0478] [Examples 2-1 to 2, Examples 3-1 to 2, Examples 4-1 to 6, Comparative Example 3-1 and Comparative Example 4-1 to 2] Each device was fabricated by changing the hole transport layer 2, light-emitting layer, and electron transport layer 1 of Comparative Example 2-1 to the materials and concentrations listed in Table 3.

[0479] The evaluation results for each element are shown in Table 4. [Table 4]

[0480] Comparison with comparative examples shows that using polycyclic aromatic compounds having a structure containing the structural unit represented by formula (1) yields high efficiency and long lifespan. Furthermore, comparisons between the examples show that compound (1-31) yields a long lifespan, while compounds (1-51) and (1-52) yield high efficiency. High efficiency is achieved with the configurations of Example 3 or Example 4, with the configuration of Example 4 yielding the highest efficiency.

[0481] Polycyclic aromatic compounds having a structure containing the structural unit represented by formula (1) can be used as the emitting dopant for TADF elements, the emitting dopant for TADF elements using two types of hosts, the emitting dopant for TAF elements, and the emitting dopant for phosphorescence assist elements. From the viewpoint that fewer materials used in the element make it easier to manufacture, the emitting dopant for TADF elements and the emitting dopant for TADF elements using two types of hosts are preferred, and the emitting dopant for TADF elements is more preferred. From the viewpoint of efficiency, the emitting dopant for TAF elements and the emitting dopant for phosphorescence assist elements are preferred, and the emitting dopant for TAF elements is more preferred.

[0482] <Examples 5-7 and Comparative Examples 5-6> Organic EL elements were fabricated according to Examples 5-7 and Comparative Examples 5-6 (each example and comparative example shown in Table 5), achieving a brightness of 1000 cd / m². 2 In this context, external quantum efficiency and LT50 (initial brightness 1000 cd / m²) 2 500 cd / m² when continuously driven at the current density in the given location. 2 The time it took to reach that state was measured.

[0483] [Table 5]

[0484] <Comparative Example 5-1> (Same as Comparative Example 2-1) A 26mm x 28mm x 0.7mm glass substrate (manufactured by OptoScience Co., Ltd.), which had been polished to 50nm by sputtering an ITO film to a thickness of 200nm, was used as a transparent support substrate. This transparent support substrate was fixed to the substrate holder of a commercially available deposition apparatus (manufactured by Showa Vacuum Co., Ltd.), and molybdenum deposition boats containing HAT-CN, HTL-1, TcTa, ETL-1, and ET7, respectively, and tungsten deposition boats containing LiF and aluminum, respectively, were attached.

[0485] The following layers were sequentially formed on the ITO film of the transparent support substrate. The vacuum chamber was 5 × 10 -4 The pressure was reduced to Pa, and first, HAT-CN was heated and deposited to a thickness of 5 nm to form a hole injection layer. Next, HTL-1 was heated and deposited to a thickness of 90 nm to form hole transport layer 1, and then TcTa was heated and deposited to a thickness of 10 nm to form hole transport layer 2. Next, ETL-1 and new-DABNA were heated simultaneously and deposited to a thickness of 20 nm to form an emissive layer. The deposition rate was adjusted so that the weight ratio of ETL-1 to new-DABNA was approximately 99:1. Next, ETL-1 was heated and deposited to a thickness of 20 nm to form electron transport layer 1, and then ET7 was heated and deposited to a thickness of 10 nm to form electron transport layer 2. The deposition rate for each layer was 0.01 to 1 nm / second. After that, LiF was heated and deposited at a deposition rate of 0.01 to 0.1 nm / second to a thickness of 1 nm, and then aluminum was heated and deposited to a thickness of 100 nm to form a cathode, thereby obtaining an organic EL device. At this time, the aluminum deposition rate was adjusted to 1-10 nm / second.

[0486] The chemical structures in Table 5 and Comparative Example 5-1 are shown below.

[0487] [ka]

[0488] <Examples 5-1 to 3, Examples 6-1 to 3, Examples 7-1 to 2, Comparative Example 5-1 and Comparative Example 6-1> Each device was fabricated by changing the hole transport layer 2, light-emitting layer, and electron transport layer 1 of Comparative Example 2-1 to the materials and concentrations listed in Table 5.

[0489] The evaluation results for each element are shown in Table 6. [Table 6]

[0490] Comparison with comparative examples shows that using polycyclic aromatic compounds having a structure containing the structural unit represented by formula (2) results in high efficiency and long lifetime. Furthermore, compounds (2-3) and (2-9) that do not have an azine ring can also be used in hole transport layer 2.

[0491] Polycyclic aromatic compounds having a structure containing the structural unit represented by formula (2) can be used as hole transport layer 2, host 1, and host 2, but it is preferable to use them as host 1 or host 2, and more preferable to use them as host 1. [Explanation of Symbols]

[0492] 100 Organic Electroluminescent Devices 101 circuit board 102 Anode 103 Hole injection layer 104 Hole transport layer 105 Light-emitting layer 106 Electron transport layer 107 Electron injection layer 108 Cathode

Claims

1. A polycyclic aromatic compound having a structure represented by any formula selected from the group consisting of formulas (1-a), (1-b), (1-c), and (1-d), and comprising at least one substructure represented by any formula selected from the group consisting of formulas (B101), (B102), (B103), (B104), (B105), (B106), (B107), and (B108); 【Chemistry 1】 In formulas (1-a), (1-b), (1-c), (1-d), (B101), (B102), (B103), (B104), (B105), (B106), (B107), and (B108), Each Z is independently N or C-R Z, and each R Z is independently hydrogen or any substituent selected from the substituent group Z. Two adjacent R and Z atoms may bond to each other to form an aryl ring or a heteroaryl ring, and each of these formed aryl rings or heteroaryl rings may be substituted with a substituent selected from the substituent group Z. Each of Z=Z may independently be >O, >N-R, >C(-R)2, >Si(-R)2, >S, or >Se, and each of the R in >N-R, >C(-R)2, and >Si(-R)2 may independently be hydrogen, a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted alkyl, or a substituted or unsubstituted cycloalkyl, and the two Rs in >C(-R)2 and >Si(-R)2 may be bonded to each other to form a ring. X2 and X4 are each independently >O, >N-R, >C(-R)2, >S, or >Se, where R in >N-R is hydrogen, a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted alkyl, or a substituted or unsubstituted cycloalkyl, where R in >C(-R)2 is each independently hydrogen, a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted alkyl, or a substituted or unsubstituted cycloalkyl, and where >N-R and >C(-R)2 may be bonded at R to one or more Zs bonded to the same carbon atom. X5 is >O, >N-R, >C(-R)2, >S, or >Se, where R in >N-R is hydrogen, a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted alkyl, or a substituted or unsubstituted cycloalkyl, where R in >C(-R)2 is independently hydrogen, a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted alkyl, or a substituted or unsubstituted cycloalkyl, and the two Rs in >C(-R)2 may be bonded to each other to form a ring. n is an integer between 1 and 3. Me is methyl, In the above structure, at least one of the aryl ring or heteroaryl ring may be condensed with at least one cycloalkane, the cycloalkane may be substituted with at least one substituent, and at least one -CH2- in the cycloalkane may be replaced with -O-. At least one hydrogen atom in the above structure may be replaced with cyano, halogen, or deuterium; The substituent group Z is, An aryl that may be substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl, and cycloalkyl, A heteroaryl which may be substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl, and cycloalkyl, Diarylaminos which may be substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl, and cycloalkyl (the two aryls may be linked to each other via a linking group), A diheteroarylamino (where two heteroaryls may be linked to each other via a linking group) may be substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl, and cycloalkyl. An arylheteroarylamino (aryl and heteroaryl may be bonded to each other via linking groups) may be substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl, and cycloalkyl. Diarylboryl (the two aryl groups may be linked by a single bond or a linking group), which may be substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl, and cycloalkyl. Alkyls which may be substituted with at least one group selected from the group consisting of aryl, heteroaryl, and cycloalkyl groups, A cycloalkyl group which may be substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl, and cycloalkyl groups. An alkoxy which may be substituted with at least one group selected from the group consisting of aryl, heteroaryl, and cycloalkyl groups. Aryloxys which may be substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl and cycloalkyl, and It consists of substituted silyls.

2. All Zs are CR-R Ｚ And, X ２ Both are >N-R, X ４ The polycyclic aromatic compound according to claim 1, wherein is >O, >N-R, or >S.

3. R Ｚ The polycyclic aromatic compound according to claim 2, wherein each of them is independently hydrogen, alkyl, optionally alkyl-substituted phenyl, optionally alkyl-substituted diphenylamino, or optionally alkyl-substituted carbazolyl.

4. A polycyclic aromatic compound having a structure represented by any formula selected from the group consisting of formulas (1-f), (1-g), (1-h), and (1-i); 【Chemistry 2】 In equations (1-f), (1-g), (1-h), and (1-i), Each Z is independently N or C-R Z, and each R Z is independently hydrogen or any substituent selected from the substituent group Z. Two adjacent R and Z atoms may bond to each other to form an aryl ring or a heteroaryl ring, and each of these formed aryl rings or heteroaryl rings may be substituted with a substituent selected from the substituent group Z. Each of Z=Z may independently be >O, >N-R, >C(-R)2, >Si(-R)2, >S, or >Se, and each of the R in >N-R, >C(-R)2, and >Si(-R)2 may independently be hydrogen, a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted alkyl, or a substituted or unsubstituted cycloalkyl, and the two Rs in >C(-R)2 and >Si(-R)2 may be bonded to each other to form a ring. X2 and X4 are each independently >O, >N-R, >C(-R)2, >S, or >Se, where R in >N-R is hydrogen, a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted alkyl, or a substituted or unsubstituted cycloalkyl, where R in >C(-R)2 is each independently hydrogen, a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted alkyl, or a substituted or unsubstituted cycloalkyl, and where >N-R and >C(-R)2 may be bonded at R to one or more Zs bonded to the same carbon atom. In the above structure, at least one of the aryl ring or heteroaryl ring may be condensed with at least one cycloalkane, the cycloalkane may be substituted with at least one substituent, and at least one -CH2- in the cycloalkane may be replaced with -O-. At least one hydrogen atom in the above structure may be replaced with cyano, halogen, or deuterium; The substituent group Z is, An aryl that may be substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl, and cycloalkyl, A heteroaryl which may be substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl, and cycloalkyl, Diarylaminos which may be substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl, and cycloalkyl (the two aryls may be linked to each other via a linking group), A diheteroarylamino (where two heteroaryls may be linked to each other via a linking group) may be substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl, and cycloalkyl. An arylheteroarylamino (aryl and heteroaryl may be bonded to each other via linking groups) may be substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl, and cycloalkyl. Diarylboryl (the two aryl groups may be linked by a single bond or a linking group), which may be substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl, and cycloalkyl. Alkyls which may be substituted with at least one group selected from the group consisting of aryl, heteroaryl, and cycloalkyl groups, A cycloalkyl group which may be substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl, and cycloalkyl groups. An alkoxy which may be substituted with at least one group selected from the group consisting of aryl, heteroaryl, and cycloalkyl groups. Aryloxys which may be substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl and cycloalkyl, and It consists of substituted silyls.

5. Z is always C-R Z, The polycyclic aromatic compound according to claim 4, wherein X2 is all >N-R and X4 is >O, >N-R, or >S.

6. The polycyclic aromatic compound according to claim 5, wherein R and Z are each independently hydrogen, alkyl, optionally alkyl-substituted phenyl, optionally alkyl-substituted diphenylamino, or optionally alkyl-substituted carbazolyl.

7. Polycyclic aromatic compounds represented by any of the following formulas; 【Transformation 3】 In the formula, tBu is t-butyl.

8. A polycyclic aromatic compound according to claim 1, represented by any of the following formulas; 【Chemistry 4】 【Transformation 5】 In the formula, Me is methyl, tBu is t-butyl, Ad is 1-adamantyl, and tAm is t-amyl.

9. Polycyclic aromatic compounds having the structure represented by the following formula (2); 【Transformation 6】 In formula (2), Each Z is independent of N or C-R Ｚ And R Ｚ Each of these is independently a hydrogen atom or a substituent selected from the substituent group Z. Two adjacent R Ｚ These elements may bond to each other to form an aryl ring or a heteroaryl ring, and the formed aryl ring or heteroaryl ring may each be substituted with any substituent selected from substituent group Z. R Ｚ and adjacent R Ｚ at least one selected from the group consisting of substituents of the ring formed by bonding of the two is a group represented by a formula selected from the group consisting of formula (A-1), formula (A-2) and formula (A-3), Z = Z are independently >O, >N-R, and >C(-R). ２ , >Si(-R) ２ , >S, or >Se, and the above >N-R, the above >C(-R) ２ and the above >Si(-R) ２ Each R is independently hydrogen, a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted alkyl, or a substituted or unsubstituted cycloalkyl, and the above >C(-R) ２ and the above >Si(-R) ２ The two Rs may be bonded to each other to form a ring. In formula (A-1), W １ and W ２ These are, independently, single bonds, >C(-R Ｗ ) ２ ,>N-R Ｗ , >O, >Si(-R Ｗ ) ２ , >S, >SO or >SO ２ And, The above > N-R Ｗ R Ｗ is one of the three substituents from substituent group Z, Above>C(-R Ｗ ) ２ , >Si(-R Ｗ ) ２ R Ｗ Each of these is independently a hydrogen atom or a substituent selected from the substituent group Z. R, which bonds with the same element Ｗ They may be connected to each other, The above > N-R Ｗ ,>C(-R Ｗ ) ２ , >Si(-R Ｗ ) ２ R Ｗ Each of them may be independently coupled to at least one Y, Y is N or CR Ｙ And R Ｙ Each of these is independently a hydrogen atom or a substituent selected from the substituent group Z. R in adjacent Y Ｙ These elements may be bonded to each other to form an aryl ring or a heteroaryl ring, and the formed ring may have any substituent selected from substituent group Z. L １ is a linking group, L １ is R Ｙ Using as a coupling, any of the C-R Ｙ Is it bonded to C, or R Ｗ Using as a connecting hand > C(-R Ｗ ) ２ C, > N-R Ｗ N, >O, >Si(-R Ｗ ) ２ Bonded to Si, or R in Y Ｙ They are bonded to the ring-constituting atoms of the ring formed by the bonding of each other, * indicates the bonding position of the group represented by formula (A-1). In formula (A-2), Y is N or CR Ｙ And R Ｙ Each of these is independently a hydrogen atom or a substituent selected from the substituent group Z. R in adjacent Y Ｙ These elements may be bonded to each other to form an aryl ring or a heteroaryl ring, and the formed ring may have any substituent selected from substituent group Z. L ２ is a linking group, L ２ is R Ｙ Using as a coupling, any of the C-R Ｙ It is bonded to C, or R in Y. Ｙ They are bonded to the ring-constituting atoms of the ring formed by the bonding of each other, * indicates the bonding position of the group represented by formula (A-2). In formula (A-3), Ar ３ Each of these is independently an aryl which may be substituted with at least one substituent selected from substituent group Z, and a heteroaryl which may be substituted with at least one substituent selected from substituent group Z. W ３ is Si, P, or S, W ３ When is Si, then m is 3 and n is 0, and W ３ When P is, then m is 2 and n is 0 or 1, and W ３ When S is true, m is 1 and n is an integer between 0 and 2. L ３ is a linking group, * indicates the bonding position of the group represented by formula (A-3). In formulas (A-1), (A-2), and (A-3), L1, L2, and L3 are all linking groups represented below, 【Transformation 7】 In the above structure, at least one of the aryl ring or heteroaryl ring may be condensed with at least one cycloalkane, and at least one hydrogen in the cycloalkane may be substituted, and at least one -CH in the cycloalkane ２ The - can also be substituted with -O-. At least one hydrogen atom in the above structure may be replaced with cyano, halogen, or deuterium; The substituent group Z is, An aryl that may be substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl, and cycloalkyl, A heteroaryl which may be substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl, and cycloalkyl, Diarylaminos which may be substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl, and cycloalkyl (the two aryls may be linked to each other via a linking group), A diheteroarylamino (where two heteroaryls may be linked to each other via a linking group) may be substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl, and cycloalkyl. An arylheteroarylamino (aryl and heteroaryl may be bonded to each other via linking groups) may be substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl, and cycloalkyl. Diarylboryl (the two aryl groups may be linked by a single bond or a linking group), which may be substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl, and cycloalkyl. Alkyls which may be substituted with at least one group selected from the group consisting of aryl, heteroaryl, and cycloalkyl groups, A cycloalkyl group which may be substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl, and cycloalkyl groups. An alkoxy which may be substituted with at least one group selected from the group consisting of aryl, heteroaryl, and cycloalkyl groups. Aryloxys which may be substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl and cycloalkyl, and It consists of substituted silyls.

10. The substituents of the ring formed by the bonding of R Z or adjacent R Z groups do not include any substituents other than groups represented by formulas selected from the group consisting of formulas (A-1), (A-2), and (A-3). The polycyclic aromatic compound according to claim 9.

11. In formula (2), R Ｚ At least one of the groups is represented by formula (A-1), where R Ｚ If they are bonded together to form a ring, then the substituents of that ring and R Ｚ At least one selected from the group consisting of and is a base represented by formula (A-1), W １ > N-R Ｗ ,>C(-R Ｗ ) ２ , >O, >Si(-R Ｗ ) ２ Or > S, W ２ It is a single bond. The polycyclic aromatic compound according to claim 9.

12. The polycyclic aromatic compound according to claim 11, wherein W1 is >N-RW.

13. In formula (2), R Ｚ At least one of the groups is represented by formula (A-2), where R Ｚ If they are bonded together to form a ring, then the substituents of that ring and R Ｚ At least one selected from the group consisting of and is a base represented by formula (A-2), The group represented by formula (A-2) includes a pyridine ring, pyrimidine ring, pyrazine ring, or triazine ring as a substructure. The polycyclic aromatic compound according to claim 9.

14. In formula (2), R Ｚ At least one of the elements is a group represented by formula (A-3), where R Ｚ When two elements are bonded together to form a ring, the substituted group of that ring and R Ｚ At least one selected from the group consisting of is a base represented by formula (A-3), W ３ is Si, The polycyclic aromatic compound according to claim 9.

15. A polycyclic aromatic compound according to claim 9, represented by any of the following formulas. 【Chemistry 9】

16. A material for an organic device containing a polycyclic aromatic compound according to any one of claims 1 to 15.

17. An organic field light-emitting device having a pair of electrodes consisting of an anode and a cathode, and an organic layer disposed between the pair of electrodes, wherein the organic layer contains a polycyclic aromatic compound according to any one of claims 1 to 15.

18. It has 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 comprises a host material and a polycyclic aromatic compound according to any one of claims 1 to 8. An organic field light-emitting element in which the lowest excited triplet energy level of the host material is higher than the lowest excited triplet energy level of the polycyclic aromatic compound.

19. The device comprises a pair of electrodes consisting of an anode and a cathode, and a light-emitting layer disposed between the pair of electrodes, wherein the light-emitting layer comprises at least two selected from the group consisting of a hole-transporting host material, an electron-transporting host material, and an assisting dopant, and an emitting dopant. Organic field light-emitting element, wherein the emitting dopant is a polycyclic aromatic compound according to any one of claims 1 to 8.

20. It has 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 comprises a dopant material and a polycyclic aromatic compound according to any one of claims 9 to 15 as a host material. An organic field light-emitting element in which the lowest excited triplet energy level of the polycyclic aromatic compound is higher than the lowest excited triplet energy level of the dopant material.

21. A display device or lighting device comprising an organic electroluminescent element as described in Claim 17.

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