Polycyclic aromatic compounds

Abstract

To provide a novel compound useful as a material for an organic device, such as an organic electroluminescent element, a display apparatus and a lighting apparatus.SOLUTION: The polycyclic aromatic compound has a structure comprising one or more structural units represented by the formula (1) in the figure, where A is a monovalent group obtained by removing one hydrogen atom from a compound represented by the formula (A).SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a polycyclic aromatic compound, an organic electroluminescent device using the same, and a display device and a lighting device. [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 and green, which are 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] Organic light-emitting diodes (OLEDs) have 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] Currently, three types of light-emitting materials are used for light-emitting layers: fluorescent materials, phosphorescent materials, and thermally activated delayed fluorescence (TADF) materials. For example, improved azavorin derivatives have been reported as fluorescent materials (Patent Document 1), noble metal complexes with polydentate ligands have been developed as phosphorescent materials (Patent Document 2), and carbazonitrile compounds have been developed as thermally activated delayed fluorescence (TADF) materials (Non-Patent Document 1).

[0005] In devices using any of these materials, materials with a high lowest excited singlet energy level or lowest excited triplet energy level are used in the adjacent layer or host of the light-emitting layer to prevent energy leakage from the light-emitting layer or surrounding layer, which would lead to a decrease in efficiency. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] International Publication No. 2015 / 102118 [Patent Document 2] Japanese Patent Publication No. 2014-239225 [Non-patent literature]

[0007] [Non-Patent Document 1] Nature Vol.492 13 December 2012 [Overview of the Initiative] [Problems that the invention aims to solve]

[0008] As mentioned above, various materials have been developed for use in organic EL devices, but in order to increase the range of materials for organic EL devices, there is a need for the development of materials composed of compounds different from conventional ones. Furthermore, while Patent Document 1 reports on a polycyclic aromatic compound containing boron and an organic EL device using it, there is a need for materials for the light-emitting layer and peripheral layers that can further improve the device characteristics, including luminous efficiency and device lifetime. [Means for solving the problem]

[0009] The inventors of the present invention, through diligent research to solve the above problems, succeeded in producing a novel polycyclic aromatic compound and further discovered that this compound is effective as a material having a high lowest excited singlet energy level or a lowest excited triplet energy level. They then discovered that an excellent organic EL element can be obtained by constructing an organic EL element by using such a polycyclic aromatic compound as a host material or a material for a layer adjacent to the light-emitting layer, and arranging a light-emitting layer with a compound having a lower triplet energy as a dopant material between a pair of electrodes, thereby 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.

[0010] <1> A polycyclic aromatic compound having a structure composed of one or more structural units represented by the following formula (1);

Chemical formula

[0011] In formula (1), A is a monovalent group obtained by eliminating one hydrogen in the compound represented by formula (A), Z is independently >N or >C-R Z and R Z is independently hydrogen or any substituent selected from the substituent group Z, Two adjacent Rs Z may be bonded to each other to form an aryl ring optionally substituted with at least one substituent selected from the substituent group Z or a heteroaryl ring optionally substituted with at least one substituent selected from the substituent group Z together with the carbon to which they are bonded, Z X is the carbon bonded to the other Z X and X 2 or >N or >C-R Z and X 1 and X 2 are independently a single bond, >O, >N-R N1 >B-R B1 >C(-R C1 )2, >Si(-R S1 )2, >S, >Se, -CR E1 =CR E1 -, or 1,2-phenylene, provided that when X 1 is a single bond, X 2 is not a single bond, R N1 R B1 and R E1Each of these is independently hydrogen, an aryl which may be substituted with at least one substituent selected from substituent group Z, a heteroaryl which may be substituted with at least one substituent selected from substituent group Z, an alkyl which may be substituted with at least one substituent selected from substituent group Z, or a cycloalkyl which may be substituted with at least one substituent selected from substituent group Z, and R C1 and R S1 Each is independently hydrogen, an aryl which may be substituted with at least one substituent selected from substituent group Z, a heteroaryl which may be substituted with at least one substituent selected from substituent group Z, an alkyl which may be substituted with at least one substituent selected from substituent group Z, or a cycloalkyl which may be substituted with at least one substituent selected from substituent group Z, or the other R which is bonded to the same element. C1 or R S1 It is bonded to form a ring, W is C, Si, or Ge. Ring B is an aryl ring or a heteroaryl ring which may be substituted with at least one substituent selected from substituent group Z. At least one Y is > N, At least one Y is >CG, and G is a base represented by equation (G),

[0012] [ka]

[0013] In formula (G), Z Y is >N or >CR Z And, X 6 This is a single bond, >C(-R C6 )2, >S, >O, >NR N6 ,>Si(-R S6 )2, >Se, >Ge(-R G6 )2, -CR E6 =CRE6 - or 1,2-phenylene, where * indicates the binding position. R N6 R is hydrogen, an aryl which may be substituted with at least one substituent selected from substituent group Z, a heteroaryl which may be substituted with at least one substituent selected from substituent group Z, an alkyl which may be substituted with at least one substituent selected from substituent group Z, or a cycloalkyl which may be substituted with at least one substituent selected from substituent group Z, C6 , R S6 , and R G6 Each is independently hydrogen, an aryl which may be substituted with at least one substituent selected from substituent group Z, a heteroaryl which may be substituted with at least one substituent selected from substituent group Z, an alkyl which may be substituted with at least one substituent selected from substituent group Z, or a cycloalkyl which may be substituted with at least one substituent selected from substituent group Z, or the other R which is bonded to the same element. C6 , R S6 , or R G6 It is bonded to R to form a ring, E6 is hydrogen, an aryl which may be substituted with at least one substituent selected from substituent group Z, a heteroaryl which may be substituted with at least one substituent selected from substituent group Z, an alkyl which may be substituted with at least one substituent selected from substituent group Z, or a cycloalkyl which may be substituted with at least one substituent selected from substituent group Z. Other Y values ​​are independent of >CR Y And, R Y Each of these is independently a hydrogen atom or a substituent selected from the substituent group Z, and R Y is a group other than the group represented by formula (G), L is a single bond, arylene, heteroarylene, >O, >NR NL ,>BR BL ,>C(-R CL )2, >Si(-R SL)2, >S, or >Se, R NL and R BL R is hydrogen, an aryl which may be substituted with at least one substituent selected from substituent group Z, a heteroaryl which may be substituted with at least one substituent selected from substituent group Z, an alkyl which may be substituted with at least one substituent selected from substituent group Z, or a cycloalkyl which may be substituted with at least one substituent selected from substituent group Z. CL and R SL Each is independently hydrogen, an aryl which may be substituted with at least one substituent selected from substituent group Z, a heteroaryl which may be substituted with at least one substituent selected from substituent group Z, an alkyl which may be substituted with at least one substituent selected from substituent group Z, or a cycloalkyl which may be substituted with at least one substituent selected from substituent group Z, or the other R which is bonded to the same element. CL or R SL It is bonded to form a ring, 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.

[0014] <2> X 6 is a single bond <1> The polycyclic aromatic compounds described above. <3> Includes the following substructure <1> or <2> Polycyclic aromatic compounds as described above; [ka] In the formula, R G is R Y Alternatively, it is G, and is connected to L by *.

[0015] <4> R G is a group represented by phenyl or formula (G). <3> The polycyclic aromatic compounds described above. <5> It can be expressed by any of the following formulas <1> The polycyclic aromatic compounds described above. [ka] [ka] [ka] [ka]

[0016] <6> <1> ~ <5> A material for organic devices containing a polycyclic aromatic compound as described in any of the above. <7> It has 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 <1> ~ <5> An organic electroluminescent element containing a polycyclic aromatic compound as described in any of the above. <8> The aforementioned organic layer is a light-emitting layer. <7> Organic electroluminescent device as described above. <9> The light-emitting layer contains the polycyclic aromatic compound as a host material and further contains a dopant material. <8> Organic electroluminescent device as described above. <10> The aforementioned organic layer is an electron transport layer. <7> Organic electroluminescent device as described above. <11> <7> ~ <10> A display device or lighting device equipped with an organic electroluminescent element as described in any of the above. [Effects of the Invention]

[0017] According to a preferred embodiment of the present invention, by fabricating an organic EL device using a novel polycyclic aromatic compound, for example, as a host material in the light-emitting layer, as a component of the host material, or as a component of a layer adjacent to the light-emitting layer, it is possible to provide an organic EL device with excellent quantum efficiency and device lifetime. [Brief explanation of the drawing]

[0018] [Figure 1] This is a schematic cross-sectional view showing an organic EL element according to this embodiment. [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 device according to one aspect of the present invention. [Modes for carrying out the invention]

[0019] The present invention will be described in detail below. The following descriptions of constituent elements may be based on representative embodiments or 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).

[0020] 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, "Ad" represents 1-adamantyl, "Ph" represents phenyl, "Mes" represents mesityl (2,4,6-trimethylphenyl), "Tf" represents trifluoromethanesulfonyl, "TMS" represents trimethylsilyl, and "D" represents deuterium. In this specification, an organic electroluminescent element may be referred to as an organic EL element.

[0021] 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.

[0022] <Description of rings and substituents> First, the details of the rings and substituents used in this specification are described below.

[0023] In this specification, "hydrocarbon rings" include cycloalkane rings and cycloalkene rings, as well as the "aryl rings" described later. Specific examples of cycloalkane rings include cyclopentane rings and cyclohexane rings. Specific examples of cycloalkene rings include cyclopentene rings, cyclohexene rings, 1,3-cyclohexadiene rings, and 1,4-cyclohexadiene rings.

[0024] In this specification, "heterocycles" include not only the "heteroaryl rings" described later, but also non-aromatic heterocycles. Examples of non-aromatic heterocycles include piperidine rings, piperazine rings, and morpholine rings.

[0025] In this specification, "aryl ring" refers to, for example, an aryl ring having 6 to 30 carbon atoms, preferably an aryl ring having 6 to 16 carbon atoms, more preferably an aryl ring having 6 to 12 carbon atoms, and particularly preferably an aryl ring having 6 to 10 carbon atoms.

[0026] Specific examples of "aryl rings" include the monocyclic benzene ring, the bicyclic biphenyl ring, the condensed bicyclic naphthalene ring and indene ring, the tricyclic terphenyl ring (m-terphenyl, o-terphenyl, p-terphenyl), the condensed tricyclic acenaphthylene ring, fluorene ring, phenalene ring, phenanthrene ring, and anthracene ring, the condensed tetracyclic triphenylene ring, pyrene ring, naphthalene ring, and chrysene ring, and the condensed pentacyclic perylene ring and pentacene ring. Furthermore, the fluorene ring, benzofluorene ring, and indene ring also include structures in which a fluorene ring, benzofluorene ring, and cyclopentane ring are spiro-linked, respectively. 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 their structure are replaced by alkyl groups such as methyl, which will be described later as the first substituent, resulting in the dimethylfluorene ring, dimethylbenzofluorene ring, and dimethylindene ring, respectively.

[0027] In this specification, "heteroaryl rings" 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, "heteroaryl rings" include, for example, heterocycles containing 1 to 5 heteroatoms selected from oxygen, sulfur, and nitrogen as ring constituent atoms in addition to carbon.

[0028] Specific examples of "heteroaryl rings" include, for example, pyrrole rings, oxazole rings, isoxazole rings, thiazole rings, isothiazole rings, imidazole rings, oxadiazole 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, naphth Examples include lysine rings, purine rings, pteridine rings, carbazole rings, acridine rings, phenoxatiin rings, phenoxazine rings, phenothiazine rings, phenazine rings, phenazacillin rings, indoridine rings, furan rings, benzofuran rings, isobenzofuran rings, dibenzofuran rings, thiophene rings, benzothiophene rings, dibenzothiophene rings, furazan rings, thianthlene rings, indolocarbazole rings, benzoindocarbazole rings, dibenzoindocarbazole rings, naphthobenzofuran rings, dioxin rings, dihydroacridine rings, xanthene rings, thioxanthene rings, and dibenzodioxin rings. Furthermore, 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. Furthermore, bicyclic rings such as bipyridine rings, phenylpyridine rings, and pyridylphenyl rings, and tricyclic rings such as terpyridyl rings, bispyridylphenyl rings, and pyridylbiphenyl rings can also be listed as "heteroaryl rings." In addition, pyran rings are also included in the definition of "heteroaryl rings."

[0029] In this specification, substituents may be substituted with further substituents. For example, a particular substituent may be described as "substituted or unsubstituted." This means that the particular substituent is substituted with at least one further substituent, or is not substituted. Similarly, it may be described as "may be substituted." In this specification, the particular substituent in this case may be referred to as the "first substituent," and the further substituent as the "second substituent."

[0030] In this specification, 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. 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.

[0031] 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.

[0032] 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.

[0033] Specific examples of "aryl" include, for example, the monocyclic phenyl, the bicyclic biphenylyl (2-biphenylyl, 3-biphenylyl, or 4-biphenylyl), the condensed bicyclic naphthyl (1-naphthyl or 2-naphthyl), the 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 the 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'-f Examples include phenyl-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.

[0034] 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.

[0035] "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).

[0036] "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.

[0037] Specific examples of "heteroaryls" include, 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, cinnolinyl, quinazolinyl, quinoxalinyl, phenanthrolinyl, phthalazinyl, naphthilidinyl, prinyl, pteridinyl, carbazolyl, and These include cridinyl, phenoxathiinyl, phenoxazinyl, phenothiazinyl, phenazinyl, phenazacylinyl, indolidinyl, furanil, benzofuranil, isobenzofuranil, dibenzofuranil, naphthobenzofuranil, thienyl, benzothienyl, isobenzothienyl, dibenzothienyl, naphthobenzothienyl, benzophosphoryl, dibenzophosphoryl, monovalent group of the benzophosphorus oxide ring, monovalent group of the dibenzophosphorus oxide ring, flazanil, thianthrenil, indolocarbazolyl, benzoindolocarbazolyl, dibenzoindolocarbazolyl, imidazolinyl, or oxazolinyl. Other examples include the monovalent group of spiro[fluorene-9,9'-xanthene], the monovalent group of spirovi[silafluorene], and the monovalent group of benzocerefen.

[0038] 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.

[0039] "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" is 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).

[0040] 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" 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" 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.

[0041] The two aryl atoms in a diarylamino as the first substituent may be linked to each other via a linking group, the two heteroaryl atoms in a diheteroarylamino as the first substituent may be linked to each other via a linking group, and the aryl and heteroaryl atoms in an arylheteroarylamino as the first substituent may be linked to each other via a linking group. Here, the phrase "linked via a linking group" means, for example, that the two phenyl atoms in diphenylamino form a bond via a linking group, as shown below. This explanation also applies to diheteroarylaminos and arylheteroarylaminos formed from aryl and heteroaryl atoms.

[0042] [ka]

[0043] Specifically, the linking groups are >O and >NR. X ,>C(-R X )2, >Si(-R X Examples include )2, >S, >CO, >CS, >SO, >SO2, and >Se. X Each of these is independently an alkyl, cycloalkyl, aryl, or heteroaryl group, and these may be substituted with alkyl, cycloalkyl, aryl, or heteroaryl groups. Also, >C(-R X )2, >Si(-R X )2, R X is a single bond or a linking group X Y They may be joined via X to form a ring. Y For example, >O, >NR Y ,>C(-R Y )2, >Si(-R Y )2, >S, >CO, >CS, >SO, >SO2, and >Se are listed, R Y Each 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 X It may also be replaced with R X Each of these is independently an alkyl, cycloalkyl, substituted silyl, aryl, and heteroaryl, which may be substituted with alkyl, cycloalkyl, substituted silyl, or aryl.

[0044] 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."

[0045] 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.

[0046] "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.

[0047] Specific examples of "alkyl" include methyl, ethyl, n-propyl, isopropyl, 1-ethyl-1-methylpropyl, 1,1-diethylpropyl, 1,1,2-trimethylpropyl, 1,1,2,2-tetramethylpropyl, 1-ethyl-1,2,2-trimethylpropyl, n-butyl, isobutyl, s-butyl, t-butyl, 2-ethylbutyl, 1,1-dimethylbutyl, 3,3-dimethylbutyl, 1,1-diethylbutyl, 1-ethyl-1-methylbutyl, 1-propyl-1-methylbutyl, 1,1,3-trimethylbutyl, 1-ethyl-1,3-dimethylbutyl, n-pentyl, isopentyl, neopentyl, t-pentyl (t-amyl), 1-methylpentyl, 2-propylpentyl, 1,1-dimethylpentyl, 1-ethyl-1-methylpentyl, 1-propyl-1 -Methylpentyl, 1-butyl-1-methylpentyl, 1,1,4-trimethylpentyl, n-hexyl, 1-methylhexyl, 2-ethylhexyl, 1,1-dimethylhexyl, 1-ethyl-1-methylhexyl, 1,1,5-trimethylhexyl, 3,5,5-trimethylhexyl, n-heptyl, 1-methylheptyl, 1-hexylheptyl, 1,1-dimethylheptyl, 2,2-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.

[0048] "Alkylene" is a divalent group obtained by removing one of the hydrogen atoms of an "alkyl" group, such as methylene, ethylene, and propylene.

[0049] 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 alkantriene-yl).

[0050] "Alkenylene" is a divalent group obtained by removing one of the hydrogen atoms from "alkenyl," and vinylene is an example of this.

[0051] 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 also includes groups in which not just one but two or more single bonds are replaced with triple bonds (also called alkadiyne-yl or alkantriyne-yl).

[0052] "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.

[0053] 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, norborneyl, bicyclo[1.1.0]butyl, bicyclo[1.1.1]pentyl, bicyclo[2.1.0]pentyl, bicyclo[2.1.1]hexyl, bicyclo[3.1.0]hexyl, bicyclo[2.2.1]heptyl, bicyclo[2.2.2]octyl, adamantyl, diamantyl, decahydronaphthalenyl, or decahydroazlenyl.

[0054] "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 structure in which one hydrogen atom is removed from the aforementioned "cycloalkyl" (a monovalent group) to create a divalent group.

[0055] A "cycloalkenyl" is a group that has a structure in which at least one single bond between two carbon atoms in the aforementioned "cycloalkyl" is replaced by a double bond (for example, a group in which -CH2-CH2- is replaced by -CH=CH-), and is not an aryl group. Specifically, examples include 1-cyclohexenyl and 1-cyclopentenyl.

[0056] "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.

[0057] "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.

[0058] 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.

[0059] 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.

[0060] "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.

[0061] "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.

[0062] 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.

[0063] "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.

[0064] <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.

[0065] [ka]

[0066] 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.

[0067] 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).

[0068] 1. Polycyclic aromatic compounds of the present invention The polycyclic aromatic compound of the present invention is a polycyclic aromatic compound having a structure consisting of one or more structural units represented by formula (1).

[0069] [ka]

[0070] In formula (1), A is a monovalent group obtained by the elimination of one hydrogen atom from the compound represented by formula (A), and at least one Y is nitrogen (>N). The inventors of the present invention have found that the polycyclic aromatic compounds of the present invention, which link a nitrogen-containing aromatic ring such as triazine having a specific substituent with a bulky polycyclic structure (a polycyclic structure including a spiro bond or a spiro-like structure), have a high lowest excited triplet energy level and provide high efficiency and long lifetime when used as a host compound or electron transport layer material for phosphorescent organic EL elements or organic EL elements utilizing thermally activated delayed fluorescence.

[0071] The compound represented by formula (1) has a structure in which a monovalent group obtained by the elimination of one hydrogen atom from the compound represented by formula (A) is bonded to a six-membered ring group containing at least one nitrogen atom as a ring constituent atom by a linking group represented by L. Each part will be explained below.

[0072] The compound represented by formula (1) contains a six-membered ring group represented by formula (1-AL). The group represented by formula (1-AL) is bonded to L by *.

[0073] [ka]

[0074] In formula (1-AL), at least one Y is >N. It is preferable that two or three Ys are >N, more preferably three Ys are >N, and even more preferably three Ys are >N and form a triazine ring. In formula (1-AL), at least one Y is >C-G, and G is a group represented by formula (G).

[0075]

Chemical formula

[0076] In formula (G), Z Y are each independently >N or >C-R Z respectively. R Z has the same meaning as R in Z described below. Z Z Y is such that one or two of them are >N and the others are >C-R Z or all of them are >C-R Z is preferable, and it is more preferable that all of them are >C-R Z It is preferable that all Rs Z are hydrogen.

[0077] X 6 is a single bond, >C(-R C6 )2, >S, >O, >N-R N6 , >Si(-R S6 )2, >Se, >Ge(-R G6 )2, -CR E6 =CR E6 -, or 1,2-phenylene, and Z Y is >N or >C-R Z and * is the bonding position.

[0078] R N6is aryl optionally substituted with at least one substituent selected from the group of substituents Z, heteroaryl optionally substituted with at least one substituent selected from the group of substituents Z, alkyl optionally substituted with at least one substituent selected from the group of substituents Z, or cycloalkyl optionally substituted with at least one substituent selected from the group of substituents Z, preferably aryl optionally substituted with aryl or heteroaryl, more preferably phenyl optionally substituted with aryl or heteroaryl, and even more preferably unsubstituted phenyl. R C6 , R S6 , and R G6 are each independently hydrogen, aryl optionally substituted with at least one substituent selected from the group of substituents Z, heteroaryl optionally substituted with at least one substituent selected from the group of substituents Z, alkyl optionally substituted with at least one substituent selected from the group of substituents Z, or cycloalkyl optionally substituted with at least one substituent selected from the group of substituents Z, preferably aryl optionally substituted with aryl or heteroaryl, heteroaryl optionally substituted with aryl or heteroaryl, or unsubstituted alkyl. Preferably, both R C6 are methyl. Preferably, both R S6 are methyl. Also, preferably, both R G6 are methyl. The two R C6 may be bonded to each other to form a ring, the two R S6 may be bonded to each other to form a ring, and the two R G6 may be bonded to each other to form a ring. R E6This is hydrogen, an aryl which may be substituted with at least one substituent selected from substituent group Z, a heteroaryl which may be substituted with at least one substituent selected from substituent group Z, an alkyl which may be substituted with at least one substituent selected from substituent group Z, or a cycloalkyl which may be substituted with at least one substituent selected from substituent group Z, and all are preferably hydrogen or methyl, and more preferably hydrogen.

[0079] X 6 This is a single bond, >C(-R C6 )2, >S, >O, or >NR N6 It is preferable that it be a single bond, more preferably >S, or >O, and even more preferably a single bond.

[0080] The group represented by formula (G) is preferably a substituted carbazolyl, and more preferably an unsubstituted carbazolyl.

[0081] Any Y other than N or CG is independently CR Y And R Y Each of these is independently a substituent selected from hydrogen or substituent group Z. A substituent selected from substituent group Z may correspond to G, but R Y R is a group other than G (the group represented by formula (G)). Y It is preferably hydrogen, a substituted or unsubstituted aryl, or a substituted or unsubstituted heteroaryl; more preferably an aryl which may be substituted with hydrogen or an aryl or heteroaryl; even more preferably a phenyl which may be substituted with hydrogen or an aryl or heteroaryl; and particularly preferably hydrogen or an unsubstituted phenyl.

[0082] The group represented by formula (1-AL) is preferably the group represented by the following formula. [ka]

[0083] In the formula, R G is R Y Alternatively, it is G, and is coupled to L by *. In the formula, R G It is preferably G, a substituted or unsubstituted aryl, or a substituted or unsubstituted heteroaryl (other than G), more preferably G or an aryl which may be substituted with an aryl or heteroaryl, even more preferably G or a phenyl which may be substituted with an aryl or heteroaryl, and particularly preferably G or an unsubstituted phenyl.

[0084] <l> L is a single bond, arylene, heteroarylene, >O, >NR NL ,>BR BL ,>C(-R CL )2, >Si(-R SL )2, >S, or >Se. Arylenes and heteroarylenes may have substituents such as substituents selected from substituent group Z, but they are preferably unsubstituted.

[0085] R NL and R BL R is hydrogen, an aryl which may be substituted with at least one substituent selected from substituent group Z, a heteroaryl which may be substituted with at least one substituent selected from substituent group Z, an alkyl which may be substituted with at least one substituent selected from substituent group Z, or a cycloalkyl which may be substituted with at least one substituent selected from substituent group Z, and is preferably an aryl which may be substituted with an aryl or heteroaryl, preferably a phenyl which may be substituted with an aryl or heteroaryl, and more preferably an unsubstituted phenyl. CL and R SL Each of the two Rs is independently hydrogen, an aryl which may be substituted with at least one substituent selected from substituent group Z, a heteroaryl which may be substituted with at least one substituent selected from substituent group Z, an alkyl which may be substituted with at least one substituent selected from substituent group Z, or a cycloalkyl which may be substituted with at least one substituent selected from substituent group Z, and is preferably an aryl which may be substituted with an aryl or heteroaryl, a heteroaryl which may be substituted with an aryl or heteroaryl, or an unsubstituted alkyl. CL They may be bonded to each other to form a ring, and two R SL They may be joined to each other to form a ring.

[0086] L is preferably a single bond, an arylene, or a heteroarylene, and more preferably a single bond or a heteroarylene. As the heteroarylene, a divalent group of dibenzofuran or dibenzothiophene is preferred. The bond position is preferably at positions 2,4 or 2,8.

[0087] <Formula (A)> [ka]

[0088] In equation (A), W is C, Si, or Ge. Two Z X When bonded, W becomes a spiro atom. W is preferably carbon.

[0089] In equation (A), Z is independently either >N or >CR Z And R Z Each of these is independently a hydrogen atom or a substituent selected from substituent group Z, and two adjacent R Z These atoms may bond to each other, and together with the carbon atoms to which they are bonded, form an aryl ring or a heteroaryl ring which may be substituted with at least one substituent selected from substituent group Z.

[0090] R is a substituent (other than hydrogen). Z Furthermore, the substituents of the ring formed as described above are preferably aryls or heteroaryls that may be substituted with aryls or heteroaryls.

[0091] Z has one or two values ​​that are >N, and the rest are >CR. Z Either or both >CR Z It is preferable that all of them are >CR Z It is more preferable that it be so. Z Preferably, all of these are hydrogen.

[0092] Z X The other Z X and X 2 It is a carbon that is bonded by, or >N or >CR Z Z X The other Z X and X 2 The carbon atoms bonded together are two Z X All of them are carbon atoms and are located at the dashed line portion of equation (A) X 2 This means they are joined together. X The other Z X and X 2 It is preferable that the carbon atoms are bonded in a certain way, or that both are >CH.

[0093] X 1 and X 2 These are independent of each other: single bond, >O, >NR N1 ,>BR B1 ,>C(-R C1 )2, >Si(-R S1 )2, >S, >Se, -CR E1 =CR E1 -, or 1,2-phenylene. However, X 1 When it is a single bond, X 2 It is not a single bond. N1 , R B1 and R E1 Each of these is independently hydrogen, an aryl which may be substituted with at least one substituent selected from substituent group Z, a heteroaryl which may be substituted with at least one substituent selected from substituent group Z, an alkyl which may be substituted with at least one substituent selected from substituent group Z, or a cycloalkyl which may be substituted with at least one substituent selected from substituent group Z. N1 and R B1 It is preferably an aryl which may be substituted with an aryl or heteroaryl, preferably a substituted or unsubstituted phenyl, and more preferably an unsubstituted phenyl. E1 Both are preferably hydrogen or methyl, and more preferably both are hydrogen. C1 and R S1 Each of the two Rs is independently hydrogen, an aryl which may be substituted with at least one substituent selected from substituent group Z, a heteroaryl which may be substituted with at least one substituent selected from substituent group Z, an alkyl which may be substituted with at least one substituent selected from substituent group Z, or a cycloalkyl which may be substituted with at least one substituent selected from substituent group Z, and is preferably an aryl which may be substituted with an aryl or heteroaryl, a heteroaryl which may be substituted with an aryl or heteroaryl, or an unsubstituted alkyl. C1 They may be bonded to each other to form a ring, and two R S1 They may be joined to each other to form a ring.

[0094] X 1 >O, >NR N1 It is preferable that it is either >S or X 2 It is preferable that the bond is a single bond.

[0095] Ring B is an aryl ring or a heteroaryl ring which may be substituted with at least one substituent selected from substituent group Z, and in formula (A), it is a divalent group having bonds to two adjacent ring constituent elements on the ring. When the aryl ring and heteroaryl ring have substituents, the substituents are preferably an aryl which may be substituted with an aryl or heteroaryl, a heteroaryl which may be substituted with an aryl or heteroaryl, or an unsubstituted alkyl. Ring B is preferably an unsubstituted aryl ring or an unsubstituted heteroaryl ring. A benzene ring is preferred as the aryl ring, and a benzofuran ring, a dibenzofuran ring, a benzothiophene ring, or a dibenzothiophene ring is preferred as the heteroaryl ring.

[0096] <A monovalent group obtained by the elimination of one hydrogen atom in the compound represented by formula (A)> In formula (A), the hydrogen that is eliminated may be at any position. Preferably, the hydrogen that is eliminated is at a position other than the B ring. Specifically, any of Z, Z X , or X 1 Or X 2 In R N1 , R B1 , R C1 , R S1 , R E1 , or any hydrogen in 1,2-phenylene. >Hydrogen in Z, which is CH, R N1 R is either hydrogen or phenyl. N1 A preferred example is any of the hydrogen atoms in the phenyl compound.

[0097] <Combinations of each substructure> The combination of the six-membered ring group represented by formula (1-AL), L, and the monovalent group obtained by the elimination of one hydrogen atom from the compound represented by formula (A) is not particularly limited.

[0098] <Specific example> A preferred specific example of a structural unit represented by the following formula (1) is a structural unit in which formula (1) is represented by any of the following formulas: (1-a) to (1-i), (2-a) to (2-i), or (3-a) to (3-i).

[0099] [ka]

[0100] [ka]

[0101] [ka]

[0102] In the formula, at least one Y is >N, and all others are >CR. Y And Z, Z X , X 1 , L, R Y Now, in equation (1), Z, Z X , X 1 , L, R Y These are synonymous, and their preferred ranges are the same. 3 is >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, and 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, R 1 and R 2 Either one of the groups is represented by formula (G), and the other is either a group represented by formula (G), or a substituted or unsubstituted aryl group, or a substituted or unsubstituted heteroaryl group.

[0103] In each of equations (1-a) to (1-i), (2-a) to (2-i), and (3-a) to (3-i), it is preferable that Y is > N. 3 It is preferable that R is >O or >S. 1 and R 2 Preferably, both are groups represented by formula (G), or one is a group represented by formula (G) and the other is an unsubstituted aryl group, and more preferably, both are unsubstituted carbazolyls, or one is an unsubstituted carbazolyl and the other is an unsubstituted phenyl group.

[0104] The polycyclic aromatic compound of the present invention is a polycyclic aromatic compound having a structure consisting of one or more structural units represented by formula (1). The polycyclic aromatic compound having a structure consisting of one of the above structural units is a polycyclic aromatic compound represented by the formula described above as the structural unit represented by formula (1). The polycyclic aromatic compound having a structure consisting of two or more structural units represented by formula (1) is a compound that corresponds to a polymer of the polycyclic aromatic 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. The polymer may be in a form in which a single compound has multiple of the above unit structures, and may be in a form in which any ring contained in the above structural unit is shared by multiple unit structures, or may be in a form in which any rings contained in the above unit structures are condensed together. Furthermore, the above unit structures may be in a form in which multiple units are linked by single bonds, or by linking groups such as alkylene, phenylene, naphthylene, etc., having 1 to 3 carbon atoms. Of these, the form in which rings are shared is preferred.

[0105] <Explanation of substitution with deuterium, cyanoside, or halogen> At least one hydrogen atom in the polycyclic aromatic compound of the present invention may be replaced with deuterium, cyano, or halogen. The halogen is fluorine, chlorine, bromine, or iodine, with fluorine, chlorine, or bromine being preferred, and fluorine or chlorine being more preferred.

[0106] <Stereoisomer> The polycyclic aromatic compounds of the present invention may exist as enenthiomers or diastereomers, but regardless of the structural formula described, any pure form of stereoisomer, any mixture of stereoisomers, racemates, etc., are all included within the scope of the present invention.

[0107] <Specific examples of polycyclic aromatic compounds of the present invention> Specific examples of the polycyclic aromatic compounds of the present invention include compounds represented by any of the following structural formulas.

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[0212]

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[0213]

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[0214] [ka]

[0215] [ka]

[0216] [ka]

[0217] [ka]

[0218] [ka]

[0219] [ka]

[0220] [ka]

[0221] [ka]

[0222] 2. Method for producing polycyclic aromatic compounds The compound represented by formula (1) can be produced by applying Suzuki coupling, Negishi coupling, or other known coupling reactions, using a compound having a reactive group at a desired position on the nitrogen-containing six-membered ring in formula (1) and a compound having a reactive group at a desired position on L or the compound represented by formula (A) as starting materials. Examples of reactive groups in these reactive compounds include halogens and boronic acids.

[0223] 3. Organic devices The polycyclic aromatic compounds according to 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.

[0224] 3-1. Organic electroluminescent element The organic EL element according to this embodiment will be described in detail below with reference to the drawings. Figure 1 is a schematic cross-sectional view showing the organic EL element according to this embodiment.

[0225] <Structure of Organic Field-Emitting Light> 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.

[0226] 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.

[0227] 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.

[0228] 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".

[0229] Organic EL elements may further have either or both of the following: an electron blocking layer and / or a hole blocking layer. The electron blocking layer has a LUMO shallower than the light-emitting layer and a HOMO closer to the light-emitting layer or hole transport layer, and is positioned between the light-emitting layer and the hole transport layer. By preventing electrons from remaining in the light-emitting layer and leaking into the hole transport layer, it is possible to prevent shortened lifetime due to deterioration of the hole transport layer and decreased efficiency due to reduced recombination efficiency. The hole blocking layer has a HOMO deeper than the light-emitting layer and a LUMO closer to the light-emitting layer or hole transport layer, and is positioned between the light-emitting layer and the electron transport layer. By preventing holes from remaining in the light-emitting layer and leaking into the electron transport layer, it is possible to prevent shortened lifetime due to deterioration of the electron transport layer and decreased efficiency due to reduced recombination efficiency. The hole injection / transport layer may also serve as the electron blocking layer. The electron injection / transport layer may also serve as the hole blocking layer.

[0230] Organic EL devices may also have a high T1 layer. The high T1 layer has a higher T1 than the host compound, assisting dopant compound, or emitting dopant compound used in the light-emitting layer, and is located between the light-emitting layer and the hole transport layer and / or between the light-emitting layer and the electron blocking layer. The value of the T1 energy varies depending on the light-emitting mechanism of the device, but it has a higher T1 than the compound used as the host. By having a high T1 layer around the light-emitting layer, triplet energy is confined, and triplet energy that would not normally lead to light emission in fluorescent molecules is converted into singlet energy, thereby achieving high efficiency. The hole injection / transport layer or electron blocking layer may also serve as the high T1 layer.

[0231] The polycyclic aromatic compounds of the present invention are preferably used as materials for organic electroluminescent devices. Generally, compounds having a donor structure can be used as hole-transporting host materials and hole-transporting layers in the light-emitting layer, compounds having an acceptor structure can be used as electron-transporting host materials and electron-transporting layers, and compounds having both a donor structure and an acceptor structure can be used in the hole-transporting layer, the host, and the electron-transporting layer in the light-emitting layer. Examples of donor and acceptor structures can be found in, for example, Advanced Functional Materials 2020, 2008332. More specifically, donor structures include triarylamine structures and carbazole structures, and acceptor structures include triazine structures, pyrimidine structures, and pyridine structures. The polycyclic aromatic compounds of the present invention can be used as host materials, hole-transporting layer materials, electron-transporting layer materials, etc. in the light-emitting layer.

[0232] <Substrate for organic electroluminescent light-emitting 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.

[0233] <Anode in an organic electroluminescent element> 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.

[0234] 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.

[0235] <Hole injection layer and hole transport layer in organic electroluminescent devices> 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.

[0236] 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 low generation of trapping impurities during manufacturing and use. It is also preferable to use the polycyclic aromatic compound of the present invention as the material for the hole transport layer.

[0237] 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.

[0238] 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).

[0239] 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.

[0240] <Emitting layer in organic electroluminescent element> 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 also be preferably used as materials for the light-emitting layer.

[0241] 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 doping methods, it can be formed by co-evaporation with the host material, but it may also be pre-mixed with the host material and then deposited simultaneously, or pre-mixed with an organic solvent and the host material and then deposited by a wet deposition method.

[0242] 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.

[0243] 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 material used is preferably 0.001 to 50% by mass, more preferably 0.05 to 20% by mass, and even more preferably 0.1 to 10% by mass, relative to the total mass of the light-emitting layer material. Within this range, for example, it is preferable that concentration quenching can be prevented. Furthermore, from the viewpoint of durability, it is preferable that some or all of the hydrogen in the dopant material is deuterized.

[0244] 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.

[0245] 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.

[0246] <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.

[0247] From the viewpoint of promoting rather than inhibiting the generation of TADF in the emissive layer, the triplet energy of the host material is preferably higher than the triplet energy of the dopant or assisting dopant having the highest triplet energy 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.

[0248] 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.

[0249] The polycyclic aromatic compounds of the present invention can be preferably used as host materials. These compounds may be used alone, as hole-transporting host materials, or as electron-transporting host materials. It is preferable to use the polycyclic aromatic compounds of the present invention alone or as hole-transporting host materials.

[0250] 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.

[0251] [Hole-transporting host material (HH)] Examples of preferred hole-transporting host materials (HH) include the polycyclic aromatic compounds of the present invention, as well as compounds represented by formula (HH-1) and compounds having a substructure represented by formula (HH-1).

[0252] [ka]

[0253] In equation (HH-1), Q is >O, >S, or >NA, 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)2. A is hydrogen, aryl, heteroaryl, diarylamino, alkyl, cycloalkyl, alkoxy, or aryloxy, and two A's in >C(-A)2 may bond to each other to form an aryl, heteroaryl, or cycloalkyl group.

[0254] 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.

[0255] 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 ring 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.

[0256] Specific examples of hole-transporting host materials include the following compounds. [ka]

[0257] [ka]

[0258] [ka]

[0259] [ka]

[0260] [ka]

[0261] [ka]

[0262] [ka]

[0263] [ka]

[0264] [ka]

[0265] Of the above, HH-1-1, HH-1-2, HH-1-4 to HH-1-12, HH-1-17, HH-1-18, HH-1-20 to HH-1-24, HH-1-82, HH-1-84 to HH-1-89, HH-1-91, HH-1-92, and HH-1-106 to HH-1-108 are preferred.

[0266] [Electron-transporting host materials (EH)] Examples of electron-transporting host materials (EH) include the polycyclic aromatic compounds of the present invention, as well as compounds represented by formula (EH-1) and compounds having a substructure represented by formula (EH-1). [ka]

[0267] In equation (EH-1), Each J is independently either =C(-A)- or =N-, and at least three Js are =C(-A)-. Z is -O-, -S-, -C(=O)-, -P(=O)(-A)-, -P(=S)(-A)-, -N(-A)-, -B(-A)-, or -S(=O)2-, The carbon atom adjacent to the carbon atom bonded by Z and the carbon atom bonded by Z may also be bonded to each other by L. L is a single bond, >O, >S, or >C(-A)2. A is hydrogen, aryl, heteroaryl, diarylamino, alkyl, cycloalkyl, triarylsilyl, alkoxy, or aryloxy, and the two A's in >C(-A)2 may bond to each other to form an aryl, heteroaryl, or cycloalkyl group. When all J is =C(-A)-, then either A or Z has a heteroatom.

[0268] For aryl, heteroaryl, diarylamino, alkyl, cycloalkyl, triarylsilyl, alkoxy, or aryloxy compounds represented by A in formula (EH-1), refer to the explanation of A in formula (HH-1). For aryl, heteroaryl, and cycloalkyl compounds formed when two A's in formula (EH-1) combine with each other to form aryl, heteroaryl, or cycloalkyl compounds, refer to the explanation of A in formula (HH-1).

[0269] When an electron-transporting host material contains a substructure represented by formula (EH-1), it may contain one substructure, 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 substructure may further have substituents selected from aryl, heteroaryl, diarylamino, or aryloxy.

[0270] The following compounds are specific examples of electron-transporting host materials. [ka]

[0271] [ka]

[0272] [ka]

[0273] [ka]

[0274] [ka]

[0275] [ka]

[0276] [ka]

[0277] [ka]

[0278] 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]

[0279] 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 the substituent group Z, 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 (hereafter, "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 6 In the case of =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 the formed ring may be substituted with at least one group selected from the substituent group Z. At least one hydrogen atom in the compound and structure represented by formula (EH-1b) may be replaced by a cyano, halogen, or deuterium.

[0280] 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 5 Preferably, 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.

[0281] 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 6 ga = 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).

[0282] 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]

[0283] 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.

[0284] [ka]

[0285] [ka]

[0286] [ka]

[0287] [ka]

[0288] [ka]

[0289] [ka]

[0290] 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.

[0291] [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.

[0292] 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.

[0293] 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.

[0294] More specifically, the hole-transporting host material is preferably selected from the group consisting of HH-1-1, HH-1-2, HH-1-4 to HH-1-12, HH-1-17, HH-1-18, HH-1-20 to HH-1-24, HH-1-82, HH-1-84 to HH-1-89, HH-1-91, HH-1-92 and HH-1-106 to HH-1-108, and the electron-transporting host material is preferably 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.

[0295] 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.

[0296] 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.

[0297] 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 Materals 25(2015)361-366, Advanced Materials 26(2014)4730-4734, ACS Applied Materials and Interfaces 8(2016)32984-32991, ACS Applied Materals 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 Materials,24,2014,3970,Advanced See also Materials, 26, 2014, 5684 and Synthetic Metals, 201, 2015, 49.

[0298] <Dopant Materials> Known compounds can be used as dopant materials, and a variety of materials can be selected 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.

[0299] As the emitting 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.

[0300] Preferred examples of boron-containing polycyclic aromatic compounds include those represented by formulas (12), (13), or (14) below. [ka]

[0301] 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, 2 The C ring may be bonded 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.

[0302] 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.

[0303] 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.

[0304] [ka]

[0305] [ka]

[0306] [ka]

[0307] [ka]

[0308] 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 31 It 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.

[0309] 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.

[0310] 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.

[0311] Examples of compounds represented by formula (13) or formula (14) are shown below. [ka]

[0312] [ka]

[0313] <Thermally activated delayed phosphors (assisting dopants)> A "thermally activated delayed phosphor" refers to a compound that absorbs thermal energy, undergoes a reverse intersystem crossing from an excited triplet state to an excited singlet state, and then radiates deactivation from that 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 excited triplet state to the 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).

[0314] 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 excitation singlet energy level, determined from the short-wavelength shoulder of the fluorescence spectrum peak, is higher than that of the thermally activated delayed phosphor acting as the assisting dopant, and also higher than that of the emitting dopant.

[0315] 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 ground state energy level of the host is E(1,G), the excited singlet energy level obtained from the short-wavelength shoulder of the host's fluorescence spectrum is E(1,S,Sh), the excited triplet energy level obtained from the short-wavelength shoulder of the host's phosphorescence spectrum is E(1,T,Sh), the ground state energy level of the assisting dopant is E(2,G), the excited singlet energy level obtained from the short-wavelength shoulder of the assisting dopant's fluorescence spectrum is E(2,S,Sh), and the phosphorescence of the assisting dopant is E(2,S,Sh). Let E(2,T,Sh) be the excited triplet energy level determined from the short-wavelength shoulder of the spectrum, E(3,G) be the ground state energy level of the emitting dopant, E(3,S,Sh) be the excited singlet energy level determined from the short-wavelength shoulder of the fluorescence spectrum of the emitting dopant, and E(3,T,Sh) be the 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 excited singlet energy level E(3,S,Sh) of the emitting dopant and emits light. However, some of the excited triplet energy E(2,T,Sh) on the assisting dopant moves to the excited triplet energy level E(3,T,Sh) of the emitting dopant, or intersystem crossing occurs on the emitting dopant from the excited singlet energy level E(3,S,Sh) to the excited triplet energy level E(3,T,Sh), followed by thermal deactivation to the ground state E(3,G). Through this pathway, some of the energy is not used for emission, resulting in wasted energy.

[0316] 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.

[0317] 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 excited triplet energy level E(3,T,Sh). Therefore, even if the excited singlet energy upconverted by the assisting dopant undergoes intersystem crossing to the excited triplet energy level E(3,T,Sh) by the emitting dopant, it is either upconverted on the emitting dopant or recovered to the excited triplet energy level E(2,T,Sh) on the assisting dopant (thermally activated delayed 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.

[0318] 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.

[0319] The 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 excited triplet energy levels E(2,T,Sh) and E(3,T,Sh) of the emitter or assisting dopant having the highest 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 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 than E(2,T,Sh) and E(3,T,Sh). Furthermore, a TADF-active compound may be used as the host compound.

[0320] 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.

[0321] 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.

[0322] 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 S1T1 Because 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, so 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.

[0323] 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.

[0324] 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.

[0325] <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).

[0326] [ka]

[0327] 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.

[0328] [ka]

[0329] 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 , SiR e 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.

[0330] 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.

[0331] Other compounds represented by formula (B-1) include, for example, the following compounds. [ka]

[0332] [ka]

[0333] [ka]

[0334] 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.

[0335] <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.

[0336] 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.

[0337] 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. It is also preferable to use the polycyclic aromatic compound of the present invention as the material for the electron transport layer.

[0338] 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.

[0339] 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.

[0340] Furthermore, metal complexes containing electron-accepting nitrogen can also be used, such as quinolinol-based metal complexes, hydroxyazole complexes such as hydroxyphenyl oxazole complexes, azomethine complexes, tropolone metal complexes, flavonol metal complexes, and benzoquinoline metal complexes.

[0341] The materials mentioned above can be used individually, but they can also be used in combination with other materials.

[0342] 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.

[0343] 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.

[0344] 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.

[0345] <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.

[0346] 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.

[0347] 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.

[0348] <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.

[0349] 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.

[0350] 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.

[0351] <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.

[0352] <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.

[0353] 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.

[0354] 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.

[0355] 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.

[0356] 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.

[0357] 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) Film deposition 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.

[0358] <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.

[0359] <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.

[0360] 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.

[0361] <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.

[0362] <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.

[0363] 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.

[0364] (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.

[0365] <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.

[0366] <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.

[0367] 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.

[0368] <Application examples of organic electroluminescent devices> Furthermore, the present 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.

[0369] 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.

[0370] 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.

[0371] 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.

[0372] 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.

[0373] 3-2. 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]

[0374] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. First, examples of the synthesis of polycyclic aromatic compounds will be described below.

[0375] Synthesis Example 1: Synthesis of the compound represented by compound (1a-43) [ka]

[0376] Compound (X-1) (2.0 g), compound (X-2) (1.56 g), dichlorobistriphenylphosphine palladium (0.09 g), tetrabutylammonium bromide (TBAB) (0.42 g), potassium carbonate (1.81 g), toluene (20.0 ml), and water (20.0 ml) were added and the mixture was heated and stirred for 5 hours. After the reaction was complete, the reaction mixture was cooled to room temperature, pure water and toluene were added, and the organic layer was separated. The organic layer was concentrated under reduced pressure, and the resulting crude product was dissolved in toluene and passed through a silica gel PASS column (eluent: toluene, heptane). The solvent of the fraction containing the target product was removed under reduced pressure to obtain the compound represented by formula (1a-43Y) (0.74 g).

[0377] 1 H-NMR(500Mz,CDCl3)δ=9.2229(d,2H),8.082(d,2H),8.053-8.030(m,4H),7.696-7.624(m,3H),7 .521(t,2H),7.445-7.375(m,4H),7.273-7.172(m,6H),7.091(t,1H),6.849(t,2H),6.584(d,2H). MALDI-TOF-MS(M+H)=653.76

[0378] Synthesis Example 2: Synthesis of Compounds Represented by Formula (1a-14) [ka]

[0379] Compound (X-3) (3.0g), compound (X-2) (2.34g), dichlorobistriphenylphosphine palladium (0.14g), tetrabutylammonium bromide (TBAB) (0.63g), potassium carbonate (2.71g), toluene (20.0ml), and water (20.0ml) were added and the mixture was heated and stirred for 5 hours. After the reaction was complete, the reaction mixture was cooled to room temperature, pure water and toluene were added, and the organic layer was separated. The organic layer was concentrated under reduced pressure, and the resulting crude product was dissolved in toluene and passed through a silica gel PASS column (eluent: toluene, heptane). The solvent of the fraction containing the target product was removed under reduced pressure to obtain compound (2.71g) represented by formula (1a-14).

[0380] 1 H-NMR(500MzCDCl3)δ=8.764(d,2H),8.627(d,1H),8.557(d,2H),7.997(d,2H),7.908(d,2H),7.839(d,1H),7. 593(t,1H),7.542(t,2H),7.459-7.415(m,5H),7.375(t,2H),7.309-7.219(m,6H),6.839(t,1H),6.478(d,1H). MALDI-TOF-MS(M+H)=653.76

[0381] Synthesis Example 3: Synthesis of the compound represented by formula (2q-1) [ka]

[0382] Compound (X-4) (3.0g), compound (X-2) (2.34g), dichlorobistriphenylphosphine palladium (0.14g), tetrabutylammonium bromide (TBAB) (0.63g), potassium carbonate (2.71g), toluene (20.0ml), and water (20.0ml) were added and the mixture was heated and stirred for 5 hours. After the reaction was complete, the reaction mixture was cooled to room temperature, and pure water and toluene were added to separate the organic layer. The organic layer was concentrated under reduced pressure, and the resulting crude product was dissolved in toluene and passed through a silica gel PASS column (eluent: toluene, heptane). The solvent of the fraction containing the target product was removed under reduced pressure to obtain compound (2.71g) represented by formula (2q-1). MALDI-TOF-MS(M+H)=653.76

[0383] Synthesis Example 4: Synthesis of Compounds Represented by Formula (1a-22) [ka]

[0384] Compound (X-3) (2.0g), compound (X-5) (1.95g), dichlorobistriphenylphosphine palladium (0.09g), tetrabutylammonium bromide (TBAB) (0.42g), potassium carbonate (1.81g), toluene (20.0ml), and water (20.0ml) were added and the mixture was heated and stirred for 5 hours. After the reaction was complete, the reaction mixture was cooled to room temperature, pure water and toluene were added, and the organic layer was separated. The organic layer was concentrated under reduced pressure, and the resulting crude product was dissolved in toluene and passed through a silica gel PASS column (eluent: toluene, heptane). The solvent of the fraction containing the target product was removed under reduced pressure to obtain compound (1.02g) represented by formula (1a-22).

[0385] 1 H-NMR(500MzCDCl3)δ=8.731(d,4H),8.587(d,1H),8.024(d,4H),7.898(d,2H),7.863(d,1 H),7.494(d,1H),7.453-7.359(m,10H),7.317-7.224(m,6H),6.839(t,1H),6.451(d,1H). MALDI-TOF-MS(M+H)=742.85

[0386] Synthesis Example 5: Synthesis of the compound represented by formula (1h-15) [ka]

[0387] Compound (X-6) (5.0g), compound (X-2) (3.88g), dichlorobistriphenylphosphine palladium (0.25g), tetrabutylammonium bromide (TBAB) (1.05g), potassium carbonate (4.50g), toluene (20.0ml), and water (20.0ml) were added and the mixture was heated and stirred for 5 hours. After the reaction was complete, the reaction mixture was cooled to room temperature, and pure water and toluene were added to separate the organic layer. The organic layer was concentrated under reduced pressure, and the resulting crude product was dissolved in toluene and passed through a silica gel PASS column (eluent: toluene, heptane). The solvent of the fraction containing the target product was removed under reduced pressure to obtain compound (3.88g) represented by formula (1h-15).

[0388] 1 H-NMR(500MzCDCl3)δ=8.931(d,2H),8.680(d,1H),8.589(d,2H),8.457(d,1H),8.018(d,2 H),7.610(t,1H),7.558(t,2H),7.391-7.243(m,11H),7.144-7.103(m,5H),7.003(d,1H). MALDI-TOF-MS(M+H)=655.77

[0389] Synthesis Example 6: Synthesis of the compound represented by formula (1j-31) [ka]

[0390] Compound (X-7) (3.0g), compound (X-2) (2.00g), dichlorobistriphenylphosphine palladium (0.12g), tetrabutylammonium bromide (TBAB) (0.54g), potassium carbonate (2.32g), toluene (30.0ml), and water (30.0ml) were added and the mixture was heated and stirred for 5 hours. After the reaction was complete, the reaction mixture was cooled to room temperature, pure water and toluene were added, and the organic layer was separated. The organic layer was concentrated under reduced pressure, and the resulting crude product was dissolved in toluene and passed through a silica gel PASS column (eluent: toluene, heptane). The solvent of the fraction containing the target product was removed under reduced pressure to obtain compound (2.25g) represented by formula (1j-31). MALDI-TOF-MS(M+H)=729.89

[0391] Synthesis Example 7: Synthesis of Compounds Represented by Formula (1a-20) [ka]

[0392] Compound (X-8) (5.0g), compound (X-2) (2.86g), dichlorobistriphenylphosphine palladium (0.17g), tetrabutylammonium bromide (TBAB) (0.77g), potassium carbonate (3.32g), toluene (50.0ml), and water (50.0ml) were added and the mixture was heated and stirred for 5 hours. After the reaction was complete, the reaction mixture was cooled to room temperature, pure water and toluene were added, and the organic layer was separated. The organic layer was concentrated under reduced pressure, and the resulting crude product was dissolved in toluene and passed through a silica gel PASS column (eluent: toluene, heptane). The solvent of the fraction containing the target product was removed under reduced pressure to obtain compound (2.29g) represented by formula (1a-20). MALDI-TOF-MS(M+H)=819.04

[0393] Synthesis Example 8: Synthesis of Compounds Represented by Formula (1a-28) [ka]

[0394] Compound (X-9) (2.0g), compound (X-2) (1.39g), dichlorobistriphenylphosphine palladium (0.07g), tetrabutylammonium bromide (TBAB) (0.30g), potassium carbonate (1.29g), toluene (20.0ml), and water (20.0ml) were added and the mixture was heated and stirred for 5 hours. After the reaction was complete, the reaction mixture was cooled to room temperature, and pure water and toluene were added to separate the organic layer. The organic layer was concentrated under reduced pressure, and the resulting crude product was dissolved in toluene and passed through a silica gel PASS column (eluent: toluene, heptane). The solvent of the fraction containing the target product was removed under reduced pressure to obtain compound (1.07g) represented by formula (1a-28). MALDI-TOF-MS(M+H)=925.09

[0395] Synthesis Example 9: Synthesis of Compounds Represented by Formula (1a-23) [ka]

[0396] Compound (X-10) (3.0g), compound (X-5) (2.14g), dichlorobistriphenylphosphine palladium (0.10g), tetrabutylammonium bromide (TBAB) (0.46g), potassium carbonate (1.99g), toluene (30.0ml), and water (30.0ml) were added and the mixture was heated and stirred for 5 hours. After the reaction was complete, the reaction mixture was cooled to room temperature, pure water and toluene were added, and the organic layer was separated. The organic layer was concentrated under reduced pressure, and the resulting crude product was dissolved in toluene and passed through a silica gel PASS column (eluent: toluene, heptane). The solvent of the fraction containing the target product was removed under reduced pressure to obtain compound (1.53g) represented by formula (1a-23). MALDI-TOF-MS(M+H)=908.03

[0397] Synthesis Example 10: Synthesis of the compound represented by formula (1b-8) [ka]

[0398] Compound (X-11) (2.0 g), compound (X-5) (2.69 g), dichlorobistriphenylphosphine palladium (0.13 g), tetrabutylammonium bromide (TBAB) (0.58 g), potassium carbonate (2.50 g), toluene (20.0 ml), and water (20.0 ml) were added and the mixture was heated and stirred for 5 hours. After the reaction was complete, the reaction mixture was cooled to room temperature, pure water and toluene were added, and the organic layer was separated. The organic layer was concentrated under reduced pressure, and the resulting crude product was dissolved in toluene and passed through a silica gel PASS column (eluent: toluene, heptane). The solvent of the fraction containing the target product was removed under reduced pressure to obtain the compound represented by formula (1b-8) (1.70 g). MALDI-TOF-MS(M+H)=741.87

[0399] Synthesis Example 11: Synthesis of the compound represented by formula (1d-20) [ka]

[0400] Compound (X-12) (2.0g), compound (X-5) (1.88g), dichlorobistriphenylphosphine palladium (0.09g), tetrabutylammonium bromide (TBAB) (0.41g), potassium carbonate (1.75g), toluene (20.0ml), and water (20.0ml) were added and the mixture was heated and stirred for 5 hours. After the reaction was complete, the reaction mixture was cooled to room temperature, pure water and toluene were added, and the organic layer was separated. The organic layer was concentrated under reduced pressure, and the resulting crude product was dissolved in toluene and passed through a silica gel PASS column (eluent: toluene, heptane). The solvent of the fraction containing the target product was removed under reduced pressure to obtain the compound represented by formula (1d-20) (0.96g). MALDI-TOF-MS(M+H)=758.92

[0401] By appropriately changing the raw material compounds, other polycyclic aromatic compounds of the present invention can be synthesized by a method similar to the synthesis example described above.

[0402] Next, the fabrication and evaluation of organic EL elements using the compounds of the present invention will be described. However, the application of the compounds of the present invention is not limited to the examples shown below, and the film thickness and constituent materials of each layer can be appropriately changed depending on the basic physical properties of the compounds of the present invention.

[0403] <Comparative Example 1-1> 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, mCBP, ETL-1, and ET7, respectively, and tungsten deposition boats containing LiF and aluminum, respectively, were attached.

[0404] 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, mCBP 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 mass ratio of mCBP 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.

[0405] <Examples 1-1 to 1-11, Examples 2-1 to 2-2, Comparative Examples 1-2 to 1-3> Each device was fabricated by changing the host 1 or electron transport layer 1 of Comparative Example 1-1 to the materials listed in Table 1.

[0406] [Table 1]

[0407] The chemical structures of the compounds used are shown below. [ka]

[0408] The fabricated organic EL element has a brightness of 1000 cd / m². 2 In this context, the 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 a certain state was measured. The evaluation results for each element are shown in Table 2.

[0409] [Table 2]

[0410] Comparison with comparative examples shows that using polycyclic aromatic compounds having a structure containing the structural unit represented by formula (1) as a host or electron transport layer results in high efficiency and long lifespan.

[0411] <Examples 3-1 to 3-4, Examples 4-1 to 4-4, and Comparative Example 3-1> Each device was fabricated by changing Host 1 in Comparative Example 1-1 to Host 1 and Host 2 at the concentrations listed in Table 3, and using the respective materials listed in Table 3 for the electron transport layer 1. In the following tables, "Host 1" corresponds to the hole-transporting host material, and "Host 2" corresponds to the electron-transporting host material.

[0412] [Table 3]

[0413] [ka]

[0414] The fabricated organic EL element has a brightness of 1000 cd / m². 2 In this context, the 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 a certain state was measured. The evaluation results for each element are shown in Table 4.

[0415] [Table 4]

[0416] Comparison with comparative examples shows that using a polycyclic aromatic compound having a structure containing the structural unit represented by formula (1) as a component of the host or as an electron transport layer yields high efficiency and long lifespan.

[0417] <Comparative Example 5-1> 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, T2T, TcTa, BCC-TPTA, ETL-1, and ET7, respectively, and tungsten deposition boats containing LiF and aluminum, respectively, were attached.

[0418] 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, T2T, TcTa, BCC-TPTA, 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 mass ratio of T2T, TcTa, BCC-TPTA, and new-DABNA was approximately 44.5:44.5:10:1. 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. 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. At this time, the deposition rate of the aluminum was adjusted to 1 to 10 nm / second.

[0419] <Examples 5-1 to 5-3, and Examples 6-1 to 6-3> Each element was fabricated by changing the composition of the light-emitting layer in Comparative Example 5-1 to the materials and concentrations listed in Table 5.

[0420] [Table 5]

[0421] [ka]

[0422] The fabricated organic EL element has a brightness of 1000 cd / m². 2 In this context, the 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 a certain state was measured. The evaluation results for each element are shown in Table 6.

[0423] [Table 6]

[0424] Comparison with comparative examples shows that using a polycyclic aromatic compound having a structure containing the structural unit represented by formula (1) as one component of the host results in high efficiency and long lifespan. [Explanation of Symbols]

[0425] 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< / l>

Claims

1. A polycyclic aromatic compound having a structure consisting of one of the structural units represented by the following formula (1'); 【Chemistry 1】 In formula (1'), A is a monovalent group obtained by the elimination of one hydrogen atom in the compound represented by formula (A), 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 They may bond to each other and, together with the carbon to which they are bonded, form an aryl ring or a heteroaryl ring which may be substituted with at least one substituent selected from substituent group Z. Z Ｘ The other Z Ｘ and X ２ It is a carbon that is bonded by, or >N or >C-R Ｚ And, X １ and X ２ are each independently a single bond or >O, provided that when X １ is a single bond, X ２ is not a single bond W is C, Ring B is an aryl ring or a heteroaryl ring which may be substituted with at least one substituent selected from substituent group Z. G is a carbazolyl which may have any substituent selected from the substituent group Z, R Ｇ is R Ｙ Or G, R Ｙ Each of these is independently a substituent selected from hydrogen or substituent group Z, and R Ｙ is a group other than the group represented by formula (G), 【Chemistry 2】 In formula (G), Z Ｙ is >N or >CR-R Ｚ And, X ６ This is a single bond, >C(-R Ｃ６ ) ２ , >S, >O, >NR Ｎ６ , >Si(-R Ｓ６ ) ２ , >Se, >Ge(-R Ｇ６ ) ２ , -CR Ｅ６ =CR Ｅ６ - or 1,2-phenylene, where * indicates the binding position. R Ｎ６ R is hydrogen, an aryl which may be substituted with at least one substituent selected from substituent group Z, a heteroaryl which may be substituted with at least one substituent selected from substituent group Z, an alkyl which may be substituted with at least one substituent selected from substituent group Z, or a cycloalkyl which may be substituted with at least one substituent selected from substituent group Z, Ｃ６ , R Ｓ６ , and R Ｇ６ Each is independently hydrogen, an aryl which may be substituted with at least one substituent selected from substituent group Z, a heteroaryl which may be substituted with at least one substituent selected from substituent group Z, an alkyl which may be substituted with at least one substituent selected from substituent group Z, or a cycloalkyl which may be substituted with at least one substituent selected from substituent group Z, or the other R bonded to the same element. Ｃ６ , R Ｓ６ , or R Ｇ６ It is bonded to R to form a ring, Ｅ６ is hydrogen, an aryl which may be substituted with at least one substituent selected from substituent group Z, a heteroaryl which may be substituted with at least one substituent selected from substituent group Z, an alkyl which may be substituted with at least one substituent selected from substituent group Z, or a cycloalkyl which may be substituted with at least one substituent selected from substituent group Z. L is a single bond, arylene, heteroarylene, >O, >N-R ＮＬ ,>B-R ＢＬ ,>C(-R ＣＬ ) ２ , >Si(-R ＳＬ ) ２ , >S, or >Se, R ＮＬ and R ＢＬ R is hydrogen, an aryl which may be substituted with at least one substituent selected from substituent group Z, a heteroaryl which may be substituted with at least one substituent selected from substituent group Z, an alkyl which may be substituted with at least one substituent selected from substituent group Z, or a cycloalkyl which may be substituted with at least one substituent selected from substituent group Z. ＣＬ and R ＳＬ Each is independently hydrogen, an aryl which may be substituted with at least one substituent selected from substituent group Z, a heteroaryl which may be substituted with at least one substituent selected from substituent group Z, an alkyl which may be substituted with at least one substituent selected from substituent group Z, or a cycloalkyl which may be substituted with at least one substituent selected from substituent group Z, or the other R bonded to the same element. ＣＬ or R ＳＬ It is bonded to form a ring, 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 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. R Ｇ The polycyclic aromatic compound according to claim 1, wherein is a carbazolyl which may have any substituent selected from phenyl or substituent group Z.

3. The polycyclic aromatic compound according to claim 1 or 2, wherein G is an unsubstituted carbazolyl.

4. The polycyclic aromatic compound according to any one of claims 1 to 3, wherein L is a single bond, a divalent group of dibenzofuran, or a divalent group of dibenzothiophene.

5. A polycyclic aromatic compound according to claim 1, represented by any of the following formulas. 【Transformation 3】 【Chemistry 4】 【Transformation 5】

6. A material for organic devices containing a polycyclic aromatic compound according to any one of claims 1 to 5.

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

8. The organic field light-emitting element according to claim 7, wherein the organic layer is a light-emitting layer.

9. The organic electroluminescent element according to claim 8, wherein the light-emitting layer contains the polycyclic aromatic compound as a host material and further contains a dopant material.

10. The organic field light-emitting element according to claim 7, wherein the organic layer is an electron transport layer.

11. A display device or lighting device comprising an organic electroluminescent element according to any one of claims 7 to 10.

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