Polycyclic aromatic compounds

Abstract

Provided is a novel compound useful as a material for organic devices such as organic EL elements. 【Solution means】A polycyclic aromatic compound represented by formula (I) is provided; TIFF2026095336000243.tif49170 Ring A, Ring B, Ring D, Ring E, and Ring F are aryl rings or heteroaryl rings, at least one of which has cyano as a substituent, and Z 0 is -C(-H)=, Y is B, X 1 ~X 4 is >N-R NX , >O, or >S, and R NX is unsubstituted aryl, provided that X 1 and X 2 where R NX is a group represented by formula (Ar) is N-R NX , or X 1 and X 3 or X 2 and X 4 are each R NX is mesityl is N-R NX and G is substituted or unsubstituted aryl or substituted or unsubstituted alkyl, etc.

Description

[Technical Field]

[0001] The present invention relates to polycyclic aromatic compounds. The present invention also relates to organic devices such as organic field-light-emitting devices, organic field-effect transistors, and organic thin-film solar cells using the above-mentioned polycyclic aromatic compounds, as well as display devices and lighting devices. [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] In particular, Patent Documents 1 and 2 disclose that polycyclic aromatic compounds containing boron are useful as materials for organic electroluminescent devices and the like. It has been reported that organic electroluminescent devices containing these polycyclic aromatic compounds have good external quantum efficiency. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] International Publication No. 2015 / 102118 [Patent Document 2] Japanese Patent Publication No. 2023-152686 [Overview of the Initiative] [Problems that the invention aims to solve]

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

[0007] The present inventors diligently studied to solve the above problems and discovered a compound having a boron-containing structure similar to the compounds described in Patent Documents 1 and 2, which enables the manufacture of organic EL elements with even higher efficiency and longer lifespan, thus completing the present invention. That is, the present invention provides the following polycyclic aromatic compounds, and further, materials for organic devices containing the following polycyclic aromatic compounds.

[0008] <1> A polycyclic aromatic compound represented by formula (I); [ka]

[0009] In formula (I), Rings A, B, D, and E are each independently a substituted or unsubstituted aryl ring or a substituted or unsubstituted heteroaryl ring, wherein at least one selected from the group consisting of rings A, B, c, D, and E is an aryl ring having at least cyano as a substituent or a heteroaryl ring having at least cyano as a substituent. Z 0 -C(-R Z0 ) = or -N = R Z0 Each is independently either hydrogen or a substituent. Y is, independently of each other, B, P, P=O, or P=S, X 1 , X 2 , X 3 , and X 4 are, independently of each other, >N-R NX , >O, >S or >Se, and R NX is hydrogen, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted alkyl, or substituted or unsubstituted cycloalkyl, R NX may be bonded to at least one of the A ring or the B ring, at least one of the A ring or the c ring, at least one of the B ring or the D ring, or at least one of the c ring or the E ring via a single bond or a linking group, provided that X 1 , X 2 , X 3 , and X 4 satisfy at least one of the following (a) and (b): (a) X 1 and X 2 are each independently N-R NX in which R NX is a group represented by the formula (Ar); (b) X 1 and X 3 are each N-R NX in which R NX is mesityl, or X 2 and X 4 are each N-R NX in which R NX is mesityl, In the formula (Ar), * indicates the bonding position to nitrogen, the F ring is a substituted or unsubstituted aryl ring or a substituted or unsubstituted heteroaryl ring, and contains at least a 6-membered ring containing an atom to which G is bonded as a ring-constituting atom, G is a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted arylthio, a substituted or unsubstituted heteroarylthio, a substituted or unsubstituted aryloxy, a substituted or unsubstituted heteroaryloxy, a substituted or unsubstituted alkyl, or a substituted or unsubstituted cycloalkyl. At least one selected from the group consisting of aryl rings and heteroaryl rings in formula (I) may be condensed with at least one cycloalkane, the cycloalkane may be substituted with at least one substituent, and at least one -CH2- in the cycloalkane may be replaced with -O- In equation (I), at least one hydrogen may be replaced by deuterium, and at least one nitrogen may be nitrogen-15( 15 N) may be replaced by sulfur-33( 33 S), Sulfur-34( 34 S) or sulfur-36( 36 S), at least one oxygen, oxygen-17( 17 O) or oxygen-18( 18 O), at least one carbon is carbon-13 ( 13 C) At least one boron is boron-11( 11 B) can be used as a substitute.

[0010] <2> Represented by equation (II), <1> Polycyclic aromatic compounds as described above; [ka]

[0011] In formula (II), Z 0 Z in equation (I) 0 It is synonymous with, X 3 and X 4 X in equation (I) 3 and X 4 These are synonymous, Ar is a group represented by formula (Ar), Z and Q are independent of each other, -C(-R Z ) = or -N = and R Z is hydrogen or a substituent, At least one Q is -C(-CN)=.

[0012] <3> Represented by equations (II-1-i) to (II-1-v), (II-2-i), (II-2-ii), (II-3-i), (II-3-ii), (II-4-i), or (II-5-i), <2> Polycyclic aromatic compounds as described above; [ka] In the above formula, Z 0 And Ar is Z in equation (II). 0 And are synonymous with Ar, respectively. Z is independent of -C(-R Z ) = or -N = and R Z is a hydrogen atom or a substituent.

[0013] <4> X 1 , X 2 , X 3 , and X 4 (b) satisfies, X 1 , X 2 , X 3 , and X 4 All of them are >NR NX That is, <1> The polycyclic aromatic compounds described above. <5> The F ring is a substituted or unsubstituted benzene ring, dibenzofuran ring, or dibenzothiophene ring. <1> ~ <4> A polycyclic aromatic compound as described in any of the following.

[0014] <6> Expressed by one of the following formulas: <1> The polycyclic aromatic compounds described above. [ka]

[0015] [ka]

[0016] [ka]

[0017] [ka]

[0018] [ka]

[0019] <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> ~ <6> 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 includes at least one selected from the group consisting of assisting dopants and phosphorescent materials. <8> Organic electroluminescent device as described above. <10> <7> ~ <9> A display device or lighting device equipped with an organic electroluminescent element as described in any of the above. <11> <1> ~ <6> A wavelength conversion material containing a polycyclic aromatic compound as described in any of the following. <12> An organic photodiode comprising a pair of electrodes and an active layer disposed between the pair of electrodes, wherein the active layer is <1> ~ <6> An organic photodiode comprising a polycyclic aromatic compound as described in any of the following. <13> The active layer consists of the polycyclic aromatic compound. <12> The organic photodiode described above. <14> <1> ~ <6> A solar cell material containing a polycyclic aromatic compound as described in any of the following. [Effects of the Invention]

[0020] The present invention provides novel polycyclic aromatic compounds useful as materials for organic devices such as organic electroluminescent devices. The polycyclic aromatic compounds of the present invention can be used in the manufacture of organic devices such as organic electroluminescent devices. [Brief explanation of the drawing]

[0021] [Figure 1] This is a schematic cross-sectional view showing an example of an organic field light-emitting device. [Modes for carrying out the invention]

[0022] 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).

[0023] In the chemical formulas and structural formulas of this specification, "Me" represents methyl, "Et" represents ethyl, "nBu" represents n-butyl (n-butyl), "tBu" represents t-butyl (tert-butyl), "iBu" represents isobutyl, "secBu" represents secondary butyl, "nPr" represents n-propyl (n-propyl), "iPr" represents isopropyl, "tAm" represents t-amyl, "2EH" represents 2-ethylhexyl, "tOct" represents t-octyl, "Ph" represents phenyl, "Mes" represents mesityl (2,4,6-trimethylphenyl), "Ad" represents 1-adamantyl, "Tf" represents trifluoromethanesulfonyl, "TMS" represents trimethylsilyl, and "D" represents deuterium. In this specification, an organic electroluminescent element may be referred to as an organic EL element.

[0024] 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.

[0025] <Description of rings and substituents> First, the details of the rings and substituents used in this specification are described below. 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 formation of 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, nitrogen, boron, silicon, selenium, phosphorus, and tellurium 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 (such as furazan rings), thiadiazole rings, triazole rings, tetrazole rings, pyrazole rings, pyridine rings, pyrimidine rings, pyridazine rings, pyrazine rings, triazine rings, indole rings, isoindole rings, 1H-indazole rings, benzimidazole rings, benzoxazole rings, benzothiazole rings, 1H-benzotriazole rings, quinoline rings, isoquinoline rings, sinnoline rings, quinazoline rings, quinoxaline rings, phthalazine rings, naphthyridine rings, purine rings, pteridine rings, carbazole rings, acridine rings, phenoxatiin rings, phenoxazine rings, phenothiazine rings, phenazine rings, phenazacillin rings, indidine rings, furan rings, benzofuran rings, isobenzofuran rings, dibenzofuran rings, and thiophene rings. , benzothiophene ring, dibenzothiophene ring, thianthrene ring, indolocarbazole ring, benzoindocarbazole ring, dibenzoindocarbazole ring, naphthobenzofuran ring, dioxin ring, dihydroacridine ring, xanthene ring, thioxanthene ring, dibenzodioxin ring, dioxabora-naphthoanthracene ring (5,9-dioxa-13b-bora-13bH-naphtho[3,2,1-de]anthracene ring, etc.), benzoselenov Examples include the phenyl ring, dibenzoselenophene ring, azacarbazole ring, azadibenzothiophene ring, azadibenzofuran ring, azadibenzoselenophene ring, azatriphenylene ring, imidazoimidazole ring, indoloindole ring, benzoflocarbazole ring, benzothienocarbazole ring, indenocarbazole ring, and selenophenocarbazole ring, spiro[fluorene-9,9'-xanthene] ring, and spirobi[silafluorene] ring. In addition, dihydroacridine rings, xanthene rings, and thioxanthene rings are also preferred in which two of the two hydrogen atoms of the methylene group in their structure are replaced by alkyl groups such as methyl as the first substituent described later, resulting in dimethyldihydroacridine rings, dimethylxanthene rings, and dimethylthioxanthene rings.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 Zα consists of substituents of substituent group Z and substituents represented by formula (A30) described below.

[0031] 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, cycloalkyl, cyano, and halogen, A heteroaryl which may be substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl, cycloalkyl, cyano, and halogen, Diarylaminos which may be substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl, cycloalkyl, cyano, and halogen (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, cycloalkyl, cyano, and halogen. 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, cycloalkyl, cyano, and halogen. Diarylboryls (the two aryls may be bonded together by a single bond or a linking group) may be substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl, cycloalkyl, cyano, and halogen. Alkyls which may be substituted with at least one group selected from the group consisting of aryl, heteroaryl, cycloalkyl, cyano, and halogen, A cycloalkyl group which may be substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl, cycloalkyl, cyano, and halogen. An alkoxy which may be substituted with at least one group selected from the group consisting of aryl, heteroaryl, cycloalkyl, cyano, and halogen, An aryloxy which may be substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl, cycloalkyl, cyano, and halogen, Arylthio, which may be substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl, cycloalkyl, cyano, and halogen, Alkenyls which may be substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl, cycloalkyl, cyano, and halogen, It consists of substituted silyls, cyanos, and halogens. The aryl secondary substituent in each group of substituent group Z may be further substituted with an aryl, heteroaryl, alkyl, cycloalkyl, cyano, or halogen; similarly, the heteroaryl secondary substituent may be substituted with an aryl, heteroaryl, alkyl, cycloalkyl, cyano, or halogen.

[0032] In this specification, the term "substituent" does not particularly limit the type of substituent, but unless otherwise specified, it may be 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.

[0033] 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.

[0034] A specific example of "aryl" is a monovalent group obtained by removing one hydrogen atom from the aforementioned "aryl ring." For example, monocyclic phenyl, bicyclic biphenylyl (2-biphenylyl, 3-biphenylyl, or 4-biphenylyl), condensed bicyclic naphthyl (1-naphthyl or 2-naphthyl), tricyclic terphenylyl (m-terphenyl-2'-yl, m-terphenyl-4'-yl, m-terphenyl-5'-yl, o-terphenyl-3'-yl, o-terphenyl-4'-yl, p-terphenyl-2'-yl, m-terphenyl-2-yl, m-terphenyl-3-yl, m-terphenyl-4-yl, o-terphenyl-2-yl, o-terphenyl-3-yl, o-terphenyl-4-yl, p-terphenyl-2-yl, p-terphenyl-3-yl, or p-terphenyl-4-yl), and condensed tricyclic acenaphthylene-(1-, 3-, 4-, or 5 -)yl, fluoren-(1-,2-,3-,4-, or 9-)yl, phenalen-(1- or 2-)yl, phenanthren-(1-,2-,3-,4-, or 9-)yl, or anthracene-(1-,2-, or 9-)yl, or the tetracyclic quaterphenylyl(5'-phenyl-m-terphenyl-2-yl, 5'-phenyl-m-terphenyl-3-yl, 5'-phenyl Examples include m-terphenyl-4-yl (or m-quaterphenyl), condensed tetracyclic groups such as triphenylene-(1- or 2-)yl, pyren-(1-, 2-, or 4-)yl, or naphthacene-(1-, 2-, or 5-)yl, or condensed pentacyclic groups such as perylene-(1-, 2-, or 3-)yl, or pentacene-(1-, 2-, 5-, or 6-)yl. Other examples include the monovalent group of spirofluorene.

[0035] 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.

[0036] "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 an "arylene" is a divalent group obtained by removing one hydrogen atom from the aforementioned "aryl" (monovalent group).

[0037] "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.

[0038] Specific examples of "heteroaryls" include monovalent groups obtained by removing one hydrogen atom from the "heteroaryl ring" mentioned above. For example, pyrrolyl, oxazolyl, isoxazolyl, thiazolyl, isothiazolyl, imidazolyl, oxadiazolyl, thiadiazolyl, triazolyl, tetrazolyl, pyrazolyl, pyridyl, pyrimidinyl, pyridadinyl, pyrazinyl, triazinyl, indolyl, isoindolyl, 1H-indazolyl, benzimidazolyl, benzoxazolyl, benzothiazolyl, 1H-benzotriazolyl, quinolinyl, isoquinolinyl, sinnolinyl, quinazolinyl, quinoxalinyl, phenanthrolinyl, phthalazinyl, naphthilidinyl, prinyl, pteridinyl, carbazolyl, These include acridinyl, phenoxathiinyl, phenoxazinyl, phenothiazinyl, phenazacylinyl, phenazacylinyl, indolidinyl, furanil, benzofuranil, isobenzofuranil, dibenzofuranil, naphthobenzofuranil, thienyl, benzothienyl, isobenzothienyl, dibenzothienyl, naphthobenzothienyl, monovalent group of the benzophosphole oxide ring, monovalent group of the dibenzophosphole oxide ring, flazanil, thianthrenil, indolocarbazolyl, benzoindolocabazolyl, dibenzoindolocabazolyl, imidazolinil, or oxazolinil. Other examples include the monovalent group of spiro[fluorene-9,9'-xanthene], the monovalent group of spirovi[silafluorene], and the monovalent group of benzoselenophene.

[0039] 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). As an example, there is a group in which the 9-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. Further, a group in which a nitrogen-containing heteroaryl such as pyridyl, pyrimidinyl, triazinyl, carbazolyl, etc. is further substituted with phenyl or biphenylyl, etc. is also included in the heteroaryl as the second substituent.

[0040] "Heteroarylene" is, for example, a heteroarylene having 2 to 30 carbon atoms, preferably a heteroarylene having 2 to 25 carbon atoms, a heteroarylene having 2 to 20 carbon atoms, a heteroarylene having 2 to 15 carbon atoms, or a heteroarylene having 2 to 10 carbon atoms, etc. Further, "heteroarylene" is, for example, a divalent group such as a heterocyclic ring containing 1 to 5 heteroatoms selected from oxygen, sulfur, and nitrogen in addition to carbon as ring-constituting atoms. Specific examples of "heteroarylene" include, for example, a divalent group obtained by removing one hydrogen from the above-mentioned "heteroaryl" (monovalent group).

[0041] "Diarylamino" is an amino substituted with two aryls, and for the details of this aryl, the description of "aryl" mentioned above can be cited. "Diheteroarylamino" is an amino group substituted with two heteroaryls, and for the details of this heteroaryl, the description of "heteroaryl" mentioned above can be cited. "Arylheteroarylamino" is an amino group substituted with aryl and heteroaryl, and for the details of this aryl and heteroaryl, the descriptions of "aryl" and "heteroaryl" mentioned above can be cited.

[0042] 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 or heteroaryl atoms.

[0043] [ka]

[0044] Specifically, the linking groups are >O and >NR. X ,>C(-R X )2, -C(-R X )=C(-R X )-,>Si(-R X )2, >S, >CO, >CS, >SO, >SO2, >SeO, >SeO2, >PO, >B(-R X Examples include ), and >Se. X Each of these is independently an alkyl, cycloalkyl, aryl, or heteroaryl, and these may be substituted with alkyl, cycloalkyl, aryl, or heteroaryl. Also, >C(-R X )2, -C(-R X )=C(-R X )-, and >Si(-R X )2 in each of the two R X is a single bond or a linking group X Y They may be joined to each other 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 YEach of these is independently an alkyl, cycloalkyl, aryl, or heteroaryl, and these may be substituted with alkyl, cycloalkyl, aryl, or heteroaryl. However, X Y >C(-R Y )2 and >Si(-R Y )In the case of 2, two R Y They do not bond to form further rings. Furthermore, alkenylenes can also be given as linking groups. Any hydrogen atom of the alkenylene can independently form R 2X It may also be replaced with R 2X Each of these is independently alkyl, cycloalkyl, substituted silyl, aryl, and heteroaryl, and these may be substituted with alkyl, cycloalkyl, substituted silyl, or aryl. -C(-R X )=C(-R X )- Two R X These may bond to each other and, together with the C=C to which they bond, form an aryl ring (such as a benzene ring) or a heteroaryl ring. That is, -C(-R X )=C(-R X )- may be an allerene (such as 1,2-phenylene) or a heteroarylene.

[0045] 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."

[0046] A "diarylboryl" is a boryl in which two aryls are substituted, and for details about these aryls, refer to the explanation of "aryl" above. These two aryls may also be linked by a single bond or by a linking group (e.g., -CH=CH-, -CR=CR-, -C≡C-, >NR, >O, >S, >CO, >C=S, >S=O, >S(=O)2, >Se(=O), >Se(=O)2, >P(=O), >B(-R), >C(-R)2, >Si(-R)2, or >Se). Here, the R in -CR=CR-, >NR, >B(-R), >C(-R)2, and >Si(-R)2 are aryl, heteroaryl, diarylamino, alkyl, alkenyl, alkynyl, cycloalkyl, alkoxy, or aryloxy, and at least one hydrogen in these groups may be further substituted with aryl, heteroaryl, alkyl, alkenyl, alkynyl, or cycloalkyl. Also, two adjacent Rs may bond to form a ring, forming cycloalkylene, arylene, and heteroarylene. For details of the substituents listed here, refer to the above-mentioned descriptions of "aryl," "arylene," "heteroaryl," "heteroarylene," and "diarylamino," as well as the later-described descriptions of "alkyl," "alkenyl," "alkynyl," "cycloalkyl," "cycloalkylene," "alkoxy," and "aryloxy." Furthermore, wherever the term "diarylboryl" is used in this specification, unless otherwise specified, it is assumed that the two aryl groups of diarylboryl may be linked to each other by a single bond or by a linking group.

[0047] "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.

[0048] 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.

[0049] "Alkylene" is a divalent group obtained by removing one of the hydrogen atoms of an "alkyl" group, such as methylene, ethylene, and propylene.

[0050] Regarding "alkenyl," you can refer to the explanation of "alkyl" above. It is a group in which a single C=C bond in the structure of "alkyl" is replaced with a C=C double bond, and it includes not just one but two or more single bonds that are replaced with double bonds (also called alkadiene-yl or alkatriene-yl).

[0051] "Alkenylene" is a divalent group obtained by removing one of the hydrogen atoms from "alkenyl," and vinylene is an example of this.

[0052] Regarding "alkynyl," you can refer to the explanation of "alkyl" above. It is a group in which a single C≡C bond in the structure of "alkyl" is replaced with a triple C≡C bond, and it includes not just one but two or more single bonds that are replaced with triple bonds (also called alkadiyne-yl or alkatriyne-yl).

[0053] "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.

[0054] Specific examples of "cycloalkyl" include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl, or alkyl (especially methyl) substituted derivatives of these with 1-5 or 1-4 carbon atoms, bicyclo[1.1.0]butyl, bicyclo[1.1.1]pentyl, bicyclo[2.1.0]pentyl, bicyclo[2.1.1]hexyl, bicyclo[3.1.0]hexyl, bicyclo[2.2.1]heptyl (norbornyl), bicyclo[2.2.2]octyl, adamantyl, diamantyl, decahydronaphthalenyl, or decahydroazlenyl.

[0055] "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.

[0056] 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.

[0057] "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.

[0058] "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.

[0059] "Replacement silyl" is, for example, silyl substituted with at least one of aryl, alkyl, and cycloalkyl, and preferably is triarylsilyl, trialkylsilyl, tricycloalkylsilyl, dialkylcycloalkylsilyl, or alkyldicycloalkylsilyl.

[0060] "Triarylsilyl" is a silyl group substituted with three aryls, and for the details of this aryl, the description of "aryl" mentioned above can be cited. Specific "triarylsilyl" is, for example, triphenylsilyl, diphenylmononaphthylsilyl, monophenyldinaphthylsilyl, or trinaphthylsilyl, etc.

[0061] "Trialkylsilyl" is a silyl group substituted with three alkyls, and for the details of this alkyl, the description of "alkyl" mentioned above can be cited. Specific "trialkylsilyl" is, for example, 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, etc.

[0062] "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.

[0063] 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.

[0064] "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.

[0065] "Halogen" is fluorine, chlorine, bromine, or iodine, preferably fluorine, chlorine, or bromine, more preferably fluorine or chlorine, and even more preferably fluorine.

[0066] When cyano or halogen substitution occurs, embodiments in which all or some of the hydrogen atoms in the aryl or heteroaryl groups in the structure are replaced by cyano or halogen are also preferred.

[0067] The substituent represented by formula (A30) has the following structure. [ka]

[0068] In formula (A30), Ak is hydrogen, a substituted or unsubstituted alkyl, a substituted or unsubstituted alkenyl, a substituted or unsubstituted cycloalkyl, or a substituted or unsubstituted cycloalkenyl, and at least one -CH2- in the alkyl, cycloalkyl, and cycloalkenyl may be replaced with -O- or -S-. R Ak R is a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted alkyl, or a substituted or unsubstituted cycloalkyl, Ak Ak may be bonded to Ak by a linking group or a single bond, and * indicates the bond position.

[0069] In formula (A30), because Ak is the substituent described above, it does not conjugate with the lone pair of electrons on N. Therefore, the lone pair of electrons can be conjugated with the π electrons of the bonded atom, allowing for a greater wavelength change compared to when an aryl atom or the like is present at the same position. Similarly, the effect on the multiple resonance effect is also similar, allowing for a greater improvement in thermally activated delayed fluorescence (TADF) properties.

[0070] R Ak It is preferably an aryl which may be substituted with alkyl or cycloalkyl, a heteroaryl which may be substituted with alkyl or cycloalkyl, an alkyl or cycloalkyl, more preferably an aryl which may be substituted with alkyl, a heteroaryl which may be substituted with alkyl, an alkyl or cycloalkyl, even more preferably an aryl which may be substituted with alkyl, and particularly preferably a phenyl which may be substituted with methyl.

[0071] In formula (A30), Ak is preferably an alkyl group having 1 to 6 carbon atoms or a cycloalkyl group having 3 to 14 carbon atoms, more preferably an alkyl group having 1 to 4 carbon atoms or a cycloalkyl group having 3 to 8 carbon atoms, more preferably an alkyl group having 1 to 4 carbon atoms, and even more preferably a methyl group.

[0072] R AkTo and Ak may be the same or different, and it is preferable that they are different.

[0073] R Ak may be bonded to Ak by a linking group or a single bond. Examples of the linking group at this time include >O, >S or >Si(-R)2. R in >Si(-R)2 is hydrogen, aryl having 6 to 12 carbon atoms, alkyl having 1 to 6 carbon atoms or cycloalkyl having 3 to 14 carbon atoms. R Ak Examples of the structure in which is bonded to Ak by a linking group or a single bond include the following.

[0074]

Chemical formula

[0075] <When two groups bonded to the same atom are bonded 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-, -C(=O)-, -C(=S)-, -S(=O)-, -S(=O)2-, -Se(=O)-, -Se(=O)2-, -P(=O)-, -B(-R)-, -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-, -B(-R)-, 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 bond to form a ring, forming a cycloalkylene, arylene, or heteroarylene.

[0076] [ka]

[0077] 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.

[0078] 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).

[0079] <Stereoisomers, etc.> The polycyclic aromatic compounds of the present invention may exist as enantiomers or diastereomers depending on the type of substituent, etc., 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.

[0080] 1. Polycyclic aromatic compounds <Description of the overall structure of the compound> It has already been found that polycyclic aromatic compounds, in which aromatic rings are linked by heteroatoms such as boron, nitrogen, oxygen, and sulfur, have a large HOMO-LUMO gap (band gap Eg in thin films). This is because the six-membered ring containing the heteroatoms has low aromaticity, which suppresses the decrease in the HOMO-LUMO gap associated with the expansion of the conjugated system. Furthermore, it has been found that the HOMO-LUMO gap can be arbitrarily changed depending on the type of heteroatom and the linking method. This is thought to be because the HOMO and LUMO energies can be arbitrarily manipulated depending on the spatial extent and energy of the empty orbitals or lone pairs of the heteroatoms.

[0081] These polycyclic aromatic compounds exhibit a narrow full width at half maximum of the fluorescence emission peak due to the localization of excited SOMO1 and SOMO2 states on each atom through electronic perturbation of heteroatoms. This results in high color purity emission when used as dopants in organic light-emitting diodes (OLEDs). For similar reasons, ΔE S1T1 The reduced size allows it to exhibit thermally activated delayed fluorescence, resulting in high efficiency when used as an emitting dopant for organic EL devices. Furthermore, by introducing substituents, the energies of the HOMO and LUMO can be arbitrarily shifted, so that the ionization potential and electron affinity can be optimized according to the surrounding materials.

[0082] The polycyclic aromatic compound of the present invention corresponds to a polycyclic aromatic compound in which the above aromatic rings are linked by hetero elements such as boron, nitrogen, oxygen, sulfur, etc., and is represented by the formula (I). The inventors have found that an organic EL device with high efficiency and long life can be manufactured using the polycyclic aromatic compound represented by the formula (I).

[0083]

Chemical formula

[0084] In formula (I), at least one selected from the group consisting of ring A, ring B, ring c, ring D and ring E is an aryl ring having at least cyano as a substituent or a heteroaryl ring having at least cyano as a substituent, and X which is a predetermined group 1 , X 2 , X 3 , and X 4 satisfy at least one of the following (a) or (b). (a) X 1 and X 2 are each independently N-R NX in which R NX is a group represented by the formula (Ar); (b) X 1 and X 3 are each N-R NX in which R NX is mesityl, or X 2 and X 4 are each N-R NX in which R NX is mesityl. Details of the symbols in formula (I) will be described later.

[0085] <Explanation of the ring structure in the compound> In equation (I), rings A, B, D, and E are each independently a substituted or unsubstituted aryl ring or a substituted or unsubstituted heteroaryl ring. In formula (I), the symbols "A", "B", "D", and "E" within the circles represent the ring structure shown in each circle. The structure represented by formula (I) has a ring structure in which at least five aromatic rings, designated as A, B, c, D, and E rings, are linked by heteroatoms such as boron, oxygen, nitrogen, and sulfur, thereby forming a further ring structure. The formed ring structure is a fused ring structure consisting of at least nine rings.

[0086] Rings A and D each have bonds to three consecutive atoms (preferably carbon) on the aryl or heteroaryl ring in their structure, forming a trivalent group. With these three bonds, ring A is X 1 , X 2 , and bonded to Y, the D ring is X 3 , X 4 , and Y are bonded. Rings A and D are further R NX When bonded, it may be a tetravalent or pentavalent group. Rings in rings A and D that have atoms with the above three bonding hands as ring constituent atoms are preferably 5-membered or 6-membered rings, and more preferably 6-membered rings. This ring may be further fused with other rings. Examples of 6-membered rings include benzene rings, pyridine rings, pyrazine rings, and pyrimidine rings. Examples of 6-membered rings that are further fused with other rings include naphthalene rings, quinoline rings, dibenzofuran rings, dibenzothiophene rings, and carbazole rings. Examples of 5-membered rings include furan rings, thiophene rings, pyrrole rings, and thiazole rings. Examples of 5-membered rings that are further fused with other rings include indene rings. In both ring A and ring D, a benzene ring is preferred as the aryl ring or heteroaryl ring.

[0087] In formula (I), both the B ring and the E ring form a divalent group with bonds to two adjacent atoms (preferably carbon) on the aryl or heteroaryl ring in their structure. The B ring has X bonds to the two atoms mentioned above. 1 And bonded to Y, the E ring is bonded to X by the two bonds mentioned above. 3 and are bonded to Y. The B ring and E ring are further bonded to R. NX When bonded, it may be a trivalent group. The rings in which the atoms having the above two bonds in each of the B and E rings are ring constituents are preferably 5-membered or 6-membered rings, and more preferably 6-membered rings. This ring may be further fused with other rings. Examples of 6-membered rings include benzene rings, pyridine rings, pyrazine rings, and pyrimidine rings. Examples of 6-membered rings being further fused with other rings include naphthalene rings, quinoline rings, benzofuran rings, benzothiophene rings, indole rings, benzoselenophen rings, dibenzofuran rings, dibenzothiophene rings, carbazole rings, and dibenzoselenophen rings. Examples of 5-membered rings include furan rings, thiophene rings, pyrrole rings, thiazole rings, and selenophen rings. Examples of 5-membered rings being further fused with other rings include benzofuran rings, benzothiophene rings, indole rings, indene rings, and benzoselenophen rings. The aryl rings or heteroaryl rings in the B ring and E ring are, independently, preferably a benzene ring, a benzofuran ring, a benzothiophene ring, or a benzoselenophene ring, more preferably a benzene ring, a benzofuran ring, or a benzothiophene ring, and even more preferably a benzene ring.

[0088] In the substituted or unsubstituted aryl rings or substituted or unsubstituted heteroaryl rings in the A, B, D, and E rings of the compound represented by formula (I), the substituent referred to as "substituted or unsubstituted" is at least one substituent selected from substituent group Zα. The substituent may also be a substituted or unsubstituted diarylphosphinone such as diphenylphosphinone, or a substituted or unsubstituted diarylphosphinyl such as diphenylphosphinyl. When multiple substituents are present, they may be identical or different from each other. Preferred substituents are substituted or unsubstituted alkyls, substituted or unsubstituted aryls, substituted or unsubstituted heteroaryls, substituted or unsubstituted diarylaminos, or halogens, with t-butyl, diphenylaminos, substituted or unsubstituted carbazolyls, or halogens being more preferred. Other preferred substituents include groups represented by formula (Ar). You can also refer to the description in <Preferred Substituents> below.

[0089] Z in the c ring of equation (I) 0 is =C(-R Z0 )- or = N-, and R Z0 R is a hydrogen atom or a substituent. Z0 The substituent may be cyanopropyl alcohol. Preferred substituents are substituted or unsubstituted alkyl groups, substituted or unsubstituted aryl groups, substituted or unsubstituted heteroaryl groups, substituted or unsubstituted diarylamino groups, or halogens; more preferably t-butyl groups, substituted or unsubstituted phenyl groups, substituted or unsubstituted 2-biphenyl groups, substituted or unsubstituted 2'-m-terphenyl groups, diphenylamino groups, substituted or unsubstituted carbazolyl groups, or halogens; and even more preferably substituted or unsubstituted 2-biphenyl groups or substituted or unsubstituted 2'-m-terphenyl groups. Z 0 It is preferable that = C(-H)-

[0090] The compound represented by formula (I) is a substituted or unsubstituted aryl ring or substituted or unsubstituted heteroaryl ring in rings A, B, D, and E, where the substituent or R is used when referring to "substituted or unsubstituted". Z0 The compound, as such, contains at least one cyanonucleotide. The compound represented by formula (I) can impart a large perturbation to the HOMO or LUMO energy by having a highly electron-withdrawing cyano substituent on a polycyclic aromatic skeleton, and when used as a dopant for organic EL elements, it can provide luminescence with high color purity.

[0091] The compound represented by formula (I) preferably contains 1 to 4 cyano groups, and more preferably 1 to 2. The number of cyano groups can be selected appropriately from the viewpoint of energy, emission spectrum, and synthesis, and the more cyano groups there are, the deeper the HOMO of the compound represented by formula (I). For preferred positions of the cyano groups, one can refer to the positions of the cyano groups shown in more specific formulas (II-1-i) to (II-1-v), (II-2-i), (II-2-ii), (II-3-i), (II-3-ii), (II-4-i), or (II-5-i).

[0092] <X 1 , X 2 , X 3 , and X 4 Explanation > X 1 , X 2 , X 3 , and X 4 These are each independent >NR NX , >O, >S, or >Se. R NX X is hydrogen, a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted alkyl, or a substituted or unsubstituted cycloalkyl. 1 , X 2 , X 3 , and X 4 R inside NX Each of these is X including itself. 1 , X 2 , X3 , or X 4 It may be bonded to one or two rings by a single bond or a linking group.

[0093] The compound represented by formula (I) satisfies at least one of the following conditions (a) and (b). (a)X 1 and X 2 Each is independent of R NX The group represented by formula (Ar) is NR NX is; (b)X 1 and X 3 Each of them is R NX NR is mesityl NX is or X 2 and X 3 Each of them is R NX NR is mesityl NX That is the case. X 1 , X 2 , X 3 , and X 4 It may satisfy only (a), only (b), or both (a) and (b). Mesityl corresponds to the group represented by formula (Ar). That is, X that satisfies at least one of (a) and (b) above. 1 , X 2 , X 3 , and X 4 At least two of them are R NX The base represented by formula (Ar) is >NR NX That is the case.

[0094] R other than the group represented by formula (Ar) NX The group is preferably a substituted or unsubstituted aryl or substituted or unsubstituted heteroaryl (excluding the group represented by formula (Ar)), more preferably a substituted or unsubstituted phenyl (excluding the group represented by formula (Ar)), and even more preferably an unsubstituted phenyl.

[0095] <X 1 , X 2, X 3 , and X 4 Explanation of changes in ring structure due to bonding with other rings> X 1 , X 2 , X 3 , and X 4 R inside NX X including itself 1 , X 2 , X 3 , or X 4 It may be bonded to one or two rings by a single bond or a linking group.

[0096] R NXExamples of linking groups when bonded to a ring include -CH2-CH2-, -CHR-CHR-, -CR2-CR2-, -CH=CH-, -CR=CR-, -C≡C-, -N(-R)-, -O-, -S-, -C(-R)2-, -C(=O)-, -C(=S)-, -S(=O)-, -S(=O)2-, -Se(=O)-, -Se(=O)2-, -P(=O)-, -B(-R)-, -Si(-R)2-, or -Se-. Of these, -CH=CH-, -CR=CR-, -N(-R)-, -O-, -S-, and -C(-R)2- are preferred, -CH=CH-, -CR=CR-, -N(-R)-, -O-, and -S- are more preferred, and -CR=CR-, -N(-R)-, -O-, and -S- are even more preferred. The R in "-CHR-CHR-", "-CR2-CR2-", "-CR=CR-", "-N(-R)-", "-C(-R)2-", "-B(-R)-", 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 alkyl or 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. Furthermore, two Rs bonded to the same atom may bond together to form a ring. In addition, two adjacent Rs may bond together to form a cycloalkylene ring, an arylene ring, and a heteroarylene ring. These rings may also be substituted with alkyl or cycloalkyl.

[0097] >NR NX R inside NX However, as a fused ring formed by bonding with a benzene ring as an aryl ring in ring A, ring B, ring c, ring D, or ring E, for example, a carbazole ring (where R is phenyl) is formed. NX (bonded by a single bond), phenoxazine ring (phenyl R) NX (bonded by -O-), phenothiazine ring (phenyl R) NX(bonded by -S-), or the acridone ring (which is phenyl R) NX Examples include those bonded by -C (=O).

[0098] Also, R NX Furthermore, the following substructure (A10) may be formed by the connection with the rings in ring A, ring B, ring c, ring D, or ring E. [ka]

[0099] In formula (A10), R A1 ~R A4 Each of these is independently hydrogen, an optionally substituted alkyl, or an optionally substituted cycloalkyl, and R A1 ~R A4 Any 2 to 4 of these may be linked to each other by linking groups or single bonds, and at the positions of the two *s, >NR NX (X 1 , X 2 , X 3 , and X 4 One of the two rings to which (either of) is joined is bonded to the other ring at the position of **. That is, N in equation (A10) is >NR NX This is N. The atoms on the ring bonded at the two * positions can be adjacent atoms (carbon atoms are preferred). The substructure represented by formula (A10) contains an NC bond with a weak bond dissociation energy (BDE), but the presence of another bond forming the ring promotes the reverse reaction (recombination reaction) when the NC bond is broken, resulting in a more stable structure. Therefore, it is expected that organic EL devices manufactured using polycyclic aromatic compounds having such a structure will have a longer device lifespan. When a polycyclic aromatic compound contains the structure represented by formula (A10), there can be one or two (preferably one) such structures.

[0100] In formula (A10), R A1 ~R A4 Any two to four of these may be linked to one another by linking groups or single bonds. R A1 ~RA4 are any two (R A1 and R A4 , R A1 and R A4 Furthermore, R A2 and R A3 , R A1 and R A2 , R A3 and R A4 , R A1 and R A2 Furthermore, R A3 and R A4 It is preferable that the ) are linked to each other by a linking group or a single bond, R A1 and R A4 It is more preferable that the groups are bonded to each other by linking groups or single bonds. Examples of divalent groups formed by bonding to each other include alkylenes. At least one hydrogen in the alkylene may be substituted with an alkyl or cycloalkyl group, and at least one (preferably one) -CH2- in the alkylene may be substituted with -O- and -S-. As divalent groups formed by bonding to each other, linear alkylenes having 2 to 5 carbon atoms are preferred, linear alkylenes having 3 or 4 carbon atoms are more preferred, and linear alkylenes having 4 carbon atoms (-(CH2)4-) are even more preferred. It is particularly preferable that the linear alkylenes having 4 carbon atoms (-(CH2)4-) are unsubstituted.

[0101] The remaining R that is not involved in linking by the linking group A1 ~R A4 Each of these is preferably independently hydrogen or an optionally substituted alkyl group, more preferably an optionally substituted C1-C6 alkyl group, even more preferably an unsubstituted C1-C6 alkyl group, and most preferably methyl in all cases. In other words, the substructure represented by formula (A10) is preferably the structure represented by formula (A11).

[0102] [ka] In formula (A11), Me is methyl and has >NR at the two * positions. NX It is bonded to one of the two rings at the position of **, and to the other ring.

[0103] <Base represented by formula (Ar)> The polycyclic aromatic compound represented by formula (I) is X 1 , X 2 , X 3 , or X 4 It is >NR NX R NX It contains at least one group represented by the following formula (Ar).

[0104] [ka]

[0105] In the formula (Ar), * indicates the bond position to nitrogen. The F ring is a substituted or unsubstituted aryl ring or a substituted or unsubstituted heteroaryl ring. G is a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted arylthio, a substituted or unsubstituted heteroarylthio, a substituted or unsubstituted aryloxy, a substituted or unsubstituted heteroaryloxy, a substituted or unsubstituted alkyl, or a substituted or unsubstituted cycloalkyl.

[0106] The aryl ring or heteroaryl ring in the A, B, c, D, or E ring has a cyano substituent, and the group represented by formula (Ar) is R NX The inventors have discovered that the polycyclic aromatic compound of the present invention makes it possible to manufacture organic EL elements, particularly TAF elements or PSF elements, that provide highly efficient and long-lasting light emission with high color purity.

[0107] In formula (Ar), the "F" within the circle is a symbol indicating a ring structure represented by the circle, and the F ring is a substituted or unsubstituted aryl ring or a substituted or unsubstituted heteroaryl ring, and includes at least a 6-membered ring containing the atom to which G is bonded as a ring constituent atom. The F ring forms a divalent group with bonds to two adjacent atoms (preferably carbon) on the aryl or heteroaryl ring in its structure, and is bonded to G and the rest of the structure represented by formula (I) by the two bonds. That is, the ring constituent atom at the bonding position of the group represented by formula (Ar) (the ring constituent atom bonded to nitrogen) is adjacent to the ring constituent atom to which G is bonded.

[0108] In the F ring, the ring containing the atom to which G is bonded is a 6-membered ring, which facilitates compound manufacturing and ensures stability during device operation. The F ring is preferably a substituted or unsubstituted benzene ring, a substituted or unsubstituted dibenzothiophene ring, a substituted or unsubstituted benzothiophene ring, a substituted or unsubstituted dibenzofuran ring, a substituted or unsubstituted benzofuran ring, a substituted or unsubstituted carbazole ring, or a substituted or unsubstituted indole ring; more preferably a substituted or unsubstituted benzene ring, a substituted or unsubstituted dibenzothiophene ring, a substituted or unsubstituted dibenzofuran ring, or a substituted or unsubstituted carbazole ring; even more preferably a substituted or unsubstituted benzene ring, a substituted or unsubstituted dibenzothiophene ring, or a substituted or unsubstituted dibenzofuran ring; and most preferably a substituted or unsubstituted benzene ring.

[0109] In a substituted or unsubstituted aryl ring or substituted or unsubstituted heteroaryl ring in the F ring, the substituent referred to as "substituted or unsubstituted" is preferably at least one substituent selected from the substituent group Zα.

[0110] In formula (Ar), G is a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted arylthio, a substituted or unsubstituted heteroarylthio, a substituted or unsubstituted aryloxy, a substituted or unsubstituted heteroaryloxy, a substituted or unsubstituted alkyl, or a substituted or unsubstituted cycloalkyl. To increase the steric hindrance caused by the group represented by formula (Ar), G is preferably a group of size of alkyl or larger with 3 carbon atoms. Specifically, a substituted or unsubstituted aryl or substituted or unsubstituted heteroaryl is preferred, a substituted or unsubstituted aryl is more preferred, and a phenyl which may be substituted with an alkyl is even more preferred. From the viewpoint of ease of synthesis, G is preferably an unsubstituted phenyl. When G is an unsubstituted alkyl with 1 to 2 carbon atoms, the F ring is preferably a substituted aryl ring or a substituted heteroaryl ring.

[0111] A preferred example of a group represented by formula (Ar) is the group represented by formula (Ar-a). [ka]

[0112] In equation (Ar-a), G is synonymous with G in equation (Ar). 1 is -C(-R Z1 )= or -N=, Z 2 is -C(-R Z2 )= or -N=, Z 3 is -C(-R Z3 )= or -N=, Z 4 is -C(-R Z4 ) = or -N = Z 1 is -C(-R Z1 )=, Z 2 is -C(-R Z2 )=, Z 3 is -C(-R Z3 )=, Z 4 is -C(-R Z4 ) = is preferable. Z1 , R Z2 , R Z3, R Z4 Each of these is independently a hydrogen atom or one of the substituents selected from the substituent group Zα.

[0113] In equation (Ar-a), R Z1 R is preferably hydrogen, an unsubstituted alkyl, an unsubstituted cycloalkyl, or a substituted or unsubstituted aryl, and more preferably hydrogen, an unsubstituted alkyl, or a phenyl which may be substituted with an alkyl. Z2 and R Z4 It is preferable that both are hydrogen. Z3 The element is preferably hydrogen, an unsubstituted alkyl, an unsubstituted cycloalkyl, or a substituted or unsubstituted aryl, and more preferably hydrogen or an unsubstituted alkyl.

[0114] When G is an unsubstituted alkyl with 1 to 2 carbon atoms, Z 1 is -C(-R Z1 )=, Z 2 is -C(-R Z2 )=, Z 3 is -C(-R Z3 )=, Z 4 is -C(-R Z4 )= and R Z1 and R Z3 Each of these is independently an unsubstituted alkyl group with 1 to 2 carbon atoms, and R Z2 and R Z4 Preferably, both are hydrogen. A preferred example of a group represented by formula (Ar) where G is an unsubstituted alkyl group having 1 to 2 carbon atoms is mesityl.

[0115] Examples of groups represented by formula (Ar) are shown below. [ka]

[0116] [ka]

[0117] Of the above, the group represented by any of formulas (Ar-1) to (Ar-16) is preferred, the group represented by any of formulas (Ar-1) to (Ar-12) is more preferred, the group represented by any of formulas (Ar-1) to (Ar-8) or (Ar-10) to (Ar-12) is even more preferred, and the group represented by any of formulas (Ar-1), (Ar-2), or (Ar-10) is particularly preferred. Note that X 1 , X 2 , X 3 , and X 4 When (b) above is satisfied, at least two of the groups represented by formula (Ar) (X 1 and X 3 , or X 2 and X 4 ) is the group (mesityl) represented by formula (Ar-16).

[0118] The number of groups represented by formula (Ar) in the polycyclic aromatic compound of the present invention is not particularly limited, but is preferably 2 to 4. 1 , X 2 , X 3 , and X 4 Included as >NR NX All R NX It is more preferable that the group is represented by formula (Ar). In polycyclic aromatic compounds, when there are multiple groups represented by formula (Ar), they may be the same or different from one another, but it is preferable that they be the same from the viewpoint of ease of synthesis, etc.

[0119] <Structure that satisfies (a)> Among the structures represented by equation (I), preferred examples of structures that satisfy (a) include structures represented by any of the following equations (1) to (7).

[0120] [ka]

[0121] In equations (1) to (7), R NXIt is preferably a substituted or unsubstituted aryl group or a substituted or unsubstituted heteroaryl group, and more preferably a group represented by formula (Ar). Of the compounds represented by any of formulas (1) to (7), from the viewpoint of high TADF properties, the compound represented by any of formulas (1), (3), (4), and (5) is preferred; from the viewpoint of short emission wavelength, the compound represented by any of formulas (2), (3), (4), and (6) is preferred; from the viewpoint of narrow full width at half maximum, the compound represented by any of formulas (1), (6), and (7) is preferred; from the viewpoint of balancing the aforementioned physical properties, the compound represented by any of formulas (1) to (5) is preferred, the compound represented by any of formulas (1), (2), (3), and (4) is more preferred, and the compound represented by any of formulas (1), (3), and (4) is even more preferred.

[0122] From another perspective, a preferred example of a structure that satisfies (a) is a polycyclic aromatic compound represented by formula (II). [ka]

[0123] In formula (II), Z 0 , X 3 , and X 4 This is Z in equation (I). 0 , X 3 , and X 4 These are synonymous and have the same preferred range. Ar is a base represented by formula (Ar), and Z and Q are independently -C(-R Z ) = or -N = and R Z Q is a hydrogen atom or substituent, and at least one Q is -C(-CN)=.

[0124] The inventors have discovered that by using a polycyclic aromatic compound represented by formula (II), in which Ar is a group represented by formula (Ar) and at least one Q is -C(-CN)=, as a dopant for an organic EL device, and particularly by using it as an emitting dopant for a TAF device or a PSF device, a long-life organic EL device that provides highly efficient blue light emission can be manufactured.

[0125] In equation (II), if either Z or Q is -N=, the number of such cases in a single ring (a 6-membered monoring) is preferably 1 to 2, and preferably 1. In equation (II), the number of -N= cases is preferably 1 to 2, and preferably 1. Both Z and Q are -C(-R Z It is preferable that )=. Z is -C(-R Z )= R Z Q is preferably a substituent other than hydrogen or CN(cyano), and is preferably hydrogen, a substituted or unsubstituted alkyl, a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, or a substituted or unsubstituted diarylamino, more preferably methyl, t-butyl, or a phenyl which may be substituted with methyl or t-butyl, and more preferably hydrogen. The substituent may be a group represented by the formula (Ar). Q which is not -C(-CN)= is preferably -C(-H)=.

[0126] In formula (II), X 3 and X 4 As shown by one of the following equations (II-1) to (II-5), >NR NX It is preferable that it be >O or >S. [ka]

[0127] The preferred positions of cyano in equations (II-1) to (II-5) are shown by equations (II-1-i) to (II-1-i) for equation (II-1), (II-2-i) and (II-2-ii) for equation (II-2), (II-3-i) and (II-3-ii) for equation (II-3), (II-4-i) for equation (II-4), and (II-5-i) for equation (II-5).

[0128] [ka]

[0129] In the above equations, Z is -C(-R Z )= or -N=, and -C(-R Z ) = is preferable. In each of the above formulas, R Z is hydrogen or a substituent, preferably hydrogen or a substituent other than CN (cyano), more preferably hydrogen, a substituted or unsubstituted alkyl, a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, or a substituted or unsubstituted diarylamino, even more preferably hydrogen, methyl, t-butyl, phenyl which may be substituted with methyl or t-butyl, 2-biphenyl which may be substituted with methyl or t-butyl, 2'-m-terphenyl which may be substituted with methyl or t-butyl, diphenylamino which may be substituted with methyl or t-butyl or phenyl, or carbazolyl which may be substituted with methyl or t-butyl or phenyl, even more preferably hydrogen, t-butyl, phenyl, 2-biphenyl, 2'-m-terphenyl, diphenylamino, or carbazolyl, and particularly preferably hydrogen.

[0130] <Structure that satisfies (b)> The inventors have found that by using a polycyclic aromatic compound represented by formula (I) that satisfies (b) as a dopant for an organic EL element, and particularly by using it as an emitting dopant for a TAF element or a PSF element, an organic EL element that provides highly efficient blue light emission can be manufactured. Among the structures represented by equation (I), preferred examples of structures that satisfy (b) include structures represented by any of the following equations (b1-1) to (b1-5) and equations (b2-1) to (b2-5).

[0131] [ka]

[0132] [ka]

[0133] Of the above, the structure represented by formula (b1-1) or formula (b2-1) is more preferred. That is, from the viewpoint of ease of synthesis, X 1 , X 2 , X 3 , and X 4 All of them are >NR NX It is preferable that this is the case. In a structure represented by any of the formulas (b1-1) to (b1-3) or (b2-1) to (b2-3), R NX It is preferably a substituted or unsubstituted aryl or a substituted or unsubstituted heteroaryl, more preferably an aryl which may be substituted with an alkyl, even more preferably a phenyl which may be substituted with an alkyl, and particularly preferably a phenyl or mesityl. In the structures represented by formulas (b1-1) to (b1-5) and (b2-1) to (b2-5), the preferred substitution positions of the cyano when rings A, B, D, and E are substituted or unsubstituted benzene rings are the same as those described for the structure represented by formula (II).

[0134] <Preferred substituents> In polycyclic aromatic compounds used as emitting dopants (and in other compounds used as dopants), tertiary alkyl groups represented by the following formula (tR) are particularly preferred as substituents containing "alkyl". This is because such bulky substituents increase the intermolecular distance, thereby improving the luminescence quantum yield (PLQY). Substituents in which the tertiary alkyl group represented by formula (tR) is substituted as a second substituent are also preferred. Specifically, examples include diarylamino compounds substituted with the tertiary alkyl group represented by formula (tR), carbazolyl compounds substituted with the tertiary alkyl group represented by formula (tR) (preferably N-carbazol), or benzocarbazoll compounds substituted with the tertiary alkyl group represented by formula (tR) (preferably N-benzocarbazol). Examples of substitutions of the (tR) group on diarylamino, carbazolyl, and benzocarbazolyl groups include cases where some or all of the hydrogen atoms in the aryl or benzene ring of these groups are replaced by the (tR) group.

[0135] [ka]

[0136] In the formula (tR), R a , R b , and R c Each of these is an alkyl group having 1 to 24 carbon atoms, and any -CH2- in the alkyl group may be substituted with -O-, and the group represented by formula (tR) has * as its bonding position.

[0137] R a , R b and R cThe "alkyl group having 1 to 24 carbon atoms" can be either linear or branched. Examples include linear alkyl groups having 1 to 24 carbon atoms or branched alkyl groups having 3 to 24 carbon atoms, alkyl groups having 1 to 18 carbon atoms (branched alkyl groups having 3 to 18 carbon atoms), alkyl groups having 1 to 12 carbon atoms (branched alkyl groups having 3 to 12 carbon atoms), alkyl groups having 1 to 6 carbon atoms (branched alkyl groups having 3 to 6 carbon atoms), and alkyl groups having 1 to 4 carbon atoms (branched alkyl groups having 3 to 4 carbon atoms).

[0138] R in equation (tR) a , R b , and R c The total number of carbon atoms is preferably 3 to 20, and particularly preferably 3 to 10.

[0139] R a , R b , and R c Specific alkyl groups include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, s-butyl, t-butyl, n-pentyl, isopentyl, neopentyl, t-pentyl, n-hexyl, 1-methylpentyl, 4-methyl-2-pentyl, 3,3-dimethylbutyl, 2-ethylbutyl, n-heptyl, 1-methylhexyl, n-octyl, t-octyl, 1-methylheptyl, 2 Examples include -ethylhexyl, 2-propylpentyl, n-nonyl, 2,2-dimethylheptyl, 2,6-dimethyl-4-heptyl, 3,5,5-trimethylhexyl, n-decyl, n-undecyl, 1-methyldecyl, n-dodecyl, n-tridecyl, 1-hexylheptyl, n-tetradecyl, n-pentadecyl, n-hexadecyl, n-heptadecyl, n-octadecyl, and n-eicosyl.

[0140] Examples of groups represented by formula (tR) include t-butyl, t-amyl, 1-ethyl-1-methylpropyl, 1,1-diethylpropyl, 1,1-dimethylbutyl, 1-ethyl-1-methylbutyl, 1,1,3,3-tetramethylbutyl, 1,1,4-trimethylpentyl, 1,1,2-trimethylpropyl, 1,1-dimethyloctyl, 1,1-dimethylpentyl, 1,1-dimethylheptyl, 1,1,5-trimethylhexyl, 1-ethyl- Examples include 1-methylhexyl, 1-ethyl-1,3-dimethylbutyl, 1,1,2,2-tetramethylpropyl, 1-butyl-1-methylpentyl, 1,1-diethylbutyl, 1-ethyl-1-methylpentyl, 1,1,3-trimethylbutyl, 1-propyl-1-methylpentyl, 1,1,2-trimethylpropyl, 1-ethyl-1,2,2-trimethylpropyl, 1-propyl-1-methylbutyl, and 1,1-dimethylhexyl. Of these, t-butyl and t-amyl are preferred.

[0141] Substituents represented by formula (A30) are also preferred.

[0142] The emission wavelength can be adjusted by the steric hindrance, electron-donating, and electron-withdrawing properties of the substituent structure of the compound used as a dopant (assisting dopant or emitting dopant). Preferably, the group is represented by the following structural formula, and more preferably, methyl, t-butyl, t-amyl, t-octyl, neopentyl, adamantyl, phenyl, o-tolyl, p-tolyl, 2,4-xylyl, 2,5-xylyl, 2,6-xylyl, 2,4,6-mesityl, diphenylamino, di-p-tolylamino, bis(p-(t-butyl)phenyl)amino, carbazolyl, 3,6-dimethylcarbazolyl, 3,6-di-t-butyl The components are rucarbazolyl and phenoxy, and more preferably methyl, t-butyl, t-amyl, t-octyl, neopentyl, adamantyl, phenyl, o-tolyl, 2,6-xylyl, 2,4,6-mesityl, diphenylamino, di-p-tolylamino, bis(p-(t-butyl)phenyl)amino, carbazolyl, 3,6-dimethylcarbazolyl, 3,6-di-t-butylcarbazolyl, and tribenzoazepinyl. From the viewpoint of ease of synthesis, greater steric hindrance is preferable for selective synthesis, and specifically, t-butyl, t-amyl, t-octyl, adamantyl, o-tolyl, p-tolyl, 2,4-xylyl, 2,5-xylyl, 2,6-xylyl, 2,4,6-mesityl, di-p-tolylamino, bis(p-(t-butyl)phenyl)amino, 3,6-dimethylcarbazolyl, and 3,6-di-t-butylcarbazolyl are preferred.

[0143] In the structural formula below, * represents a bond position. [ka]

[0144] [ka]

[0145] [ka]

[0146]

change

[0147]

change

[0148]

change

[0149]

change

[0150]

change

[0151]

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[0152]

change

[0153]

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[0154]

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[0155]

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[0156]

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[0157] In certain preferred embodiments, the polycyclic aromatic compound represented by formula (I) preferably has a structure containing at least one tert-alkyl (such as t-butyl or t-amyl), neopentyl, or adamantyl represented by formula (tR) described above, and it is preferable that it contains a tert-alkyl (such as t-butyl or t-amyl) represented by formula (tR). This is because such bulky substituents increase the intermolecular distance, thereby improving the luminescence quantum yield (PLQY). Diarylaminos are also preferred as substituents. Furthermore, diarylaminos substituted with the group of formula (tR), carbazolyls (preferably N-carbazol) substituted with the group of formula (tR), or benzocarbazolls (preferably N-benzocarbazol) substituted with the group of formula (tR) are also preferred. Examples of substitution forms of the group of formula (tR) on diarylaminos, carbazolyls, and benzocarbazolls include cases in which some or all of the hydrogens of the aryl ring or benzene ring in these groups are substituted with the group of formula (tR).

[0158] In the polycyclic aromatic compound represented by formula (I), in the substituted or unsubstituted aryl rings or substituted or unsubstituted heteroaryl rings in the B and D rings, the substituent referred to as "substituted or unsubstituted" may include a substituted or unsubstituted N-carbazolyl, which is one preferred embodiment. It has been found that when a compound having N-carbazolyl as a substituent is used as a dopant in the light-emitting layer, an organic EL device with a longer lifetime and lower drive voltage can be obtained. It is thought that by having N-carbazolyl as a substituent, the HOMO of the compound becomes deeper, the hole trapping ability decreases, and the drive voltage decreases. It is also thought that carrier recombination on the dopant becomes less likely to occur, the dopant is less likely to enter the T1 state, and the lifetime is extended. Here, when N-carbazolyl has a substituent, it is preferable that the substituent is selected from the group consisting of substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted alkyl, and substituted or unsubstituted cycloalkyl. As substituted or unsubstituted N-carbazolyls, unsubstituted or N-carbazolyls having substituents at the 1, 3, 6, or 8 positions are preferred, and unsubstituted N-carbazolyls, 3,6-di(t-butyl)N-carbazolyls, or N-carbazolyls substituted with deuterium are particularly preferred. Substituents having the following structures, in which at least one benzene ring in the N-carbazolyl is further fused with an indole ring, a benzofuran ring, a benzothiophene ring, a benzoselenophene ring, an indene ring, or a benzosilole ring, are also preferred, with benzofuran[3,2-a]carbazolyl, benzo[4,5]thieno[3,2-a]carbazolyl, benzofuran[3,2-c]carbazolyl, or benzo[4,5]thieno[3,2-c]carbazolyl being more preferred.

[0159] [ka]

[0160] In the structure represented by formula (I), the substituents of the aryl ring or heteroaryl ring may be substituents represented by the following formula (A20). [ka]

[0161] The substituent represented by formula (A20) is bonded by two * to two adjacent atoms on an aryl or heteroaryl ring. In formula (A20), L is >NR, >O, >Si(-R)2, or >S, where R in >NR is a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted alkyl, or a substituted or unsubstituted cycloalkyl, where R in >Si(-R)2 is hydrogen, an optionally substituted aryl, an optionally substituted alkyl, or an optionally substituted cycloalkyl, and the two Rs in >Si(-R)2 may be bonded to each other to form a ring, and at least one of the Rs in >NR and >Si(-R)2 may be bonded to the aryl or heteroaryl ring by a linking group or a single bond. r is an integer from 1 to 4, R A Each of these is independently hydrogen, a substituted or unsubstituted alkyl, or a substituted or unsubstituted cycloalkyl, and any R A is any other R A They may be bonded to each other by linking groups or single bonds.

[0162] Examples of the substituents mentioned above include substituents represented by any of the following: [ka]

[0163] In each formula, the asterisk (*) indicates that the atom is bonded to two or three adjacent atoms on any of the aryl or heteroaryl rings.

[0164] <Cycloalkane condensation> In the polycyclic aromatic compound represented by formula (I), at least one selected from the group consisting of aryl rings and heteroaryl rings may be condensed with at least one cycloalkane. The same applies to the structures represented by formulas (II), (II-1-i) to (II-1-v), (II-2-i), (II-2-ii), (II-3-i), (II-3-ii), (II-4-i), or (II-5-i), and the following explanation also applies to polycyclic aromatic compounds represented by any of these formulas.

[0165] The cycloalkane can be any cycloalkane having 3 to 24 carbon atoms. In this case, at least one hydrogen atom in the cycloalkane may be substituted with an aryl group having 6 to 30 carbon atoms, a heteroaryl group having 2 to 30 carbon atoms, an alkyl group having 1 to 24 carbon atoms, or a cycloalkyl group having 3 to 24 carbon atoms, and at least one -CH2- in the cycloalkane may be substituted with an -O-.

[0166] The cycloalkane is preferably a cycloalkane having 3 to 20 carbon atoms, wherein at least one hydrogen atom in the cycloalkane may be substituted with an aryl group having 6 to 16 carbon atoms, a heteroaryl group having 2 to 22 carbon atoms, an alkyl group having 1 to 12 carbon atoms, or a cycloalkyl group having 3 to 16 carbon atoms.

[0167] Examples of "cycloalkanes" include cycloalkanes with 3 to 24 carbon atoms, cycloalkanes with 3 to 20 carbon atoms, cycloalkanes with 3 to 16 carbon atoms, cycloalkanes with 3 to 14 carbon atoms, cycloalkanes with 5 to 10 carbon atoms, cycloalkanes with 5 to 8 carbon atoms, cycloalkanes with 5 to 6 carbon atoms, and cycloalkanes with 5 carbon atoms.

[0168] Specific examples of cycloalkanes include cyclopropane, cyclobutane, cyclopentane, cyclohexane, cycloheptane, cyclooctane, cyclononane, cyclodecane, norbornane (bicyclo[2.2.1]heptane), bicyclo[1.1.0]butane, bicyclo[1.1.1]pentane, bicyclo[2.1.0]pentane, bicyclo[2.1.1]hexane, bicyclo[3.1.0]hexane, bicyclo[2.2.2]octane, adamantane, diamantane, decahydronaphthalene, and decahydroazulene, as well as alkyl (especially methyl), halogen (especially fluorine), and deuterium-substituted compounds of these compounds having 1 to 5 carbon atoms.

[0169] Among the examples above, structures having at least one substituent on the α-carbon of the cycloalkane (the carbon adjacent to the carbon at the condensation site in a cycloalkane condensed to an aryl ring or heteroaryl ring), such as shown in the structural formula below, are preferred, structures having two substituents on the α-carbon are more preferred, and structures where both α-carbons each have two substituents (a total of four substituents) are even more preferred. Examples of these substituents include alkyl groups (especially methyl), halogens (especially fluorine), and deuterium, having 1 to 5 carbon atoms. In particular, structures in which a substructure represented by the following formula (B11) or (B12) is bonded to an adjacent carbon atom in the aryl ring or heteroaryl ring are preferred, and structures in which a substructure represented by the following formula (B11) is bonded are more preferred.

[0170] [ka] In formulas (B11) and (B12), * indicates a bond position.

[0171] The number of cycloalkanes condensed to a single aryl or heteroaryl ring is preferably 1 to 3, more preferably 1 or 2, and even more preferably 1. For example, the following shows an example in which one or more cycloalkanes are condensed to a single benzene ring (phenyl). * indicates the bonding position, and this position may be any carbon that constitutes the benzene ring but not the cycloalkane. Condensed cycloalkanes may also be condensed together, as in formulas (Cy-1-4) and (Cy-2-4). The same applies when the ring (group) to be condensed is an aryl or heteroaryl ring other than a benzene ring (phenyl), and when the cycloalkane to be condensed is a cycloalkane other than cyclopentane or cyclohexane.

[0172] [ka]

[0173] At least one -CH2- in a cycloalkane may be substituted with -O-. For example, the following shows a cycloalkane condensed to a single benzene ring (phenyl) in which one or more -CH2- groups are substituted with -O-. The same applies when the condensed ring (group) is an aryl ring or heteroaryl ring other than a benzene ring (phenyl), or when the condensed cycloalkane is a cycloalkane other than cyclopentane or cyclohexane.

[0174] [ka]

[0175] Cycloalkanes may be substituted with at least one substituent, which can be any substituent selected from substituent group Z. Among these substituents, alkyl (e.g., alkyls with 1 to 6 carbon atoms) and cycloalkyl (e.g., cycloalkyls with 3 to 14 carbon atoms) are preferred. It is also preferred that one of the hydrogen atoms is replaced with a halogen (e.g., fluorine) or deuterium. Furthermore, when a cycloalkyl is substituted, the substitution may form a spiro structure, for example, an example in which a spiro structure is formed on a cycloalkane condensed with one benzene ring (phenyl) is shown below. In each structural formula, * means that if it is a benzene ring, it is a benzene ring included in the backbone structure of the compound, and if it is a phenyl, it means a bond that is substituted on the backbone structure of the compound.

[0176] [ka]

[0177] One form of cycloalkane condensation is the condensation of aryl and heteroaryl rings in the A, B, D, and E rings of a polycyclic aromatic compound represented by formula (I) with a cycloalkane. Another form is the condensation of aryl and heteroaryl rings in the E or G ring of a group represented by formula (Ar) with a cycloalkane.

[0178] Other forms of cycloalkane condensation include other R in polycyclic aromatic compounds represented by formula (I). NX >NR is an aryl condensed with a cycloalkane. NX Examples include diarylamino compounds condensed with cycloalkanes (condensation on the aryl portion), carbazolyl compounds condensed with cycloalkanes (condensation on the benzene ring portion), or benzocarbazolyl compounds condensed with cycloalkanes (condensation on the benzene ring portion).

[0179] Furthermore, by introducing a cycloalkane structure to the polycyclic aromatic compound represented by formula (I), a further reduction in the melting point and sublimation temperature can be expected. This means that in sublimation purification, which is almost indispensable as a purification method for organic devices such as organic EL elements that require high purity, purification can be performed at relatively low temperatures, thus avoiding thermal decomposition of the material. The same applies to the vacuum deposition process, which is a powerful means of fabricating organic devices such as organic EL elements, as the process can be carried out at relatively low temperatures, thus avoiding thermal decomposition of the material and resulting in the acquisition of high-performance organic devices. In addition, since the solubility in organic solvents is improved by introducing a cycloalkane structure, it can also be applied to the fabrication of elements using coating processes. However, the present invention is not particularly limited to these principles.

[0180] <Replacement with heavier stable isotopes> In the polycyclic aromatic compounds represented by formula (I), each element is present in naturally occurring isotopes in their natural abundances unless otherwise specified. However, all or some of the elements in each structural formula may exceed their natural abundances (for example, boron-11( 11 B) may contain heavy stable isotopes at 90 atom percent or more. In this specification, this is simply referred to as "replacing" with "heavy stable isotopes". More specifically, at least one hydrogen can be replaced with deuterium, and at least one nitrogen can be replaced with nitrogen-15. 15 N) can be replaced with at least one sulfur, sulfur-33( 33 S), Sulfur-34( 34 S) or sulfur-36( 36 S) can be replaced with at least one oxygen, oxygen-17( 17 O) or oxygen-18( 18 It can be replaced with O), and at least one carbon is carbon-13 ( 13 C) can be replaced with at least one boron, boron-11( 11It can be replaced with B). The same applies to structures represented by formulas (II), (II-1-i) to (II-1-v), (II-2-i), (II-2-ii), (II-3-i), (II-3-ii), (II-4-i), or (II-5-i), and the following explanation also applies to polycyclic aromatic compounds represented by any of these formulas. By replacing at least some elements with heavier stable isotopes, in particular at least one boron can be replaced with boron-11( 11 By substituting with B), the lifespan of an organic electroluminescent device using a polycyclic aromatic compound represented by formula (I) as a dopant can be extended.

[0181] For example, in the polycyclic aromatic compound represented by formula (I), the hydrogen atoms in the A, B, c, D, and E rings and their substituents can be replaced with deuterium, and among these, embodiments in which all or some of the hydrogen atoms in the aryl or heteroaryl rings are replaced with deuterium are particularly noteworthy. Furthermore, from the viewpoint of durability, it is also preferable that all or some of the hydrogen atoms in the polycyclic aromatic compound represented by formula (I) are deuterated.

[0182] <Specific examples of polycyclic aromatic compounds> Examples of polycyclic aromatic compounds represented by formula (I) include compounds represented by any of the following structural formulas. [ka]

[0183] [ka]

[0184] [ka]

[0185] [ka]

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[0216] <Production method of polycyclic aromatic compounds> Among the polycyclic aromatic compounds represented by formula (I), compounds in which Y is boron can be synthesized, for example, by the methods described in Japanese Patent Publication No. 2021-063074 and Japanese Patent Publication No. 2023-152686. Furthermore, the polycyclic aromatic compounds of the present invention can be produced according to methods described in many prior art publications, such as International Publication No. 2015 / 102118 and International Publication No. 2018 / 212169.

[0217] Basically, the intermediate is first produced by bonding the ring structures together (first reaction), and then the final product is produced by bonding the ring structures with Y (for example, a boron atom) (second reaction). In the first reaction, common etherification reactions such as nucleophilic substitution reactions and Ullmann reactions, as well as common amination reactions such as the Buchwald-Hartwig reaction, nucleophilic substitution reactions, and Goldberg amination can be used. In the second reaction, the tandem hetero-Friedel-Crafts reaction (a series of electrophilic aromatic substitution reactions, hereafter the same) can be used.

[0218] The second reaction is a reaction that introduces Y (for example, a boron atom) to bond each ring structure, as shown in scheme (1) below. First, the two X(X) on the ring 1 , X 2 , X 3 , and X 4 The hydrogen atoms between the two atoms are orthometalated with n-butyllithium, sec-butyllithium, or t-butyllithium. Then, a chloride or bromide of Y (e.g., boron trichloride or boron tribromide) is added to perform a lithium-Y (e.g., boron) metal exchange, and then a Brønsted base such as N,N-diisopropylethylamine is added to carry out a tandem bora-Friedel-Crafts reaction to obtain the target product. In the second reaction, a Lewis acid such as aluminum trichloride may be added to accelerate the reaction.

[0219] [ka]

[0220] In scheme (1), lithium was introduced to the desired position by orthometallation. However, as shown in scheme (2) below, a halogen atom (Hal) can be introduced beforehand at the position where lithium is to be introduced, and then lithium can be introduced to the desired position by halogen-metal exchange. This method is useful because it allows the synthesis of the target product even in cases where orthometallation is not possible due to the influence of substituents. The halogen atom (Hal) in the formula can be any of F, Cl, Br, or I, and can be appropriately selected considering the reactivity of the substrate.

[0221] [ka]

[0222] As an example of a boron introduction reaction, the one-shot borylation reaction, which proceeds in three consecutive steps within the tandem bora-Friedel-Crafts reaction, is described below. After reacting the intermediate with a boron reagent such as boron tribromide or boron triiodide, a Brønsted base such as 2,6-di-tert-butylpyridine can be added as needed to obtain the desired compound represented by formula (1) (a compound in which Y is boron).

[0223] [ka]

[0224] Furthermore, because the location of the tandem bora-Friedel-Crafts reaction may differ depending on the rotation of, for example, the amino group in the intermediate, by-products may be generated. In such cases, the target polycyclic aromatic compound can be isolated from these mixtures by chromatography, recrystallization, etc.

[0225] Furthermore, the two Y compounds in the polycyclic aromatic compound of the present invention may be introduced simultaneously in the same reaction step, sequentially, or sequentially in different reaction steps.

[0226] The polycyclic aromatic compounds of the present invention have at least some hydrogen atoms substituted with cyano groups. Such compounds can be synthesized in the same manner as described above by using a starting material in which the desired position is cyanated. Alternatively, by using a precursor having a halogen at an appropriate position, a polycyclic aromatic compound containing a halogen can be obtained, and then a cyano group can be introduced by a general method, or a substituent containing a cyano group can be introduced by cross-coupling.

[0227] In addition, polycyclic aromatic compounds substituted with cyano groups can be synthesized by synthesizing precursors with leaving groups such as halogens or trifluoromethanesulfonyl groups, and then substituting the leaving groups with cyano groups using cyanides. Besides cyanide salts such as sodium cyanide and potassium cyanide, potassium hexacyanoferrate(II) can also be used as cyanides. This reaction can be accelerated by using catalysts such as palladium. When synthesizing precursors with leaving groups such as halogens or trifluoromethanesulfonyl groups, substituents can be introduced into the substrate beforehand to create steric hindrance, or they can be selectively introduced to desired positions by considering the reactivity of the reagents used, the reaction temperature, or the reaction mechanism.

[0228] By appropriately selecting the raw materials to be used, polycyclic aromatic compounds having substituents at desired positions can be synthesized.

[0229] A Lewis acid such as aluminum trichloride may be added to accelerate the reaction. Furthermore, the halogen atom that is Cl in the intermediate formula of scheme (1) may be F, Br, or I, and the halogen atom can be appropriately selected considering the reactivity of the substrate.

[0230] Specific examples of solvents used in the above reactions include chlorobenzene, o-dichlorobenzene, t-butylbenzene, xylene, toluene, benzene, mesitylene, methylene chloride, chloroform, dichloroethylene, benzotrifluoride, decalin, cyclohexane, hexane, heptane, 1,2,4-trimethylbenzene, diphenyl ether, anisole, cyclopentyl methyl ether, tetrahydrofuran (THF), dioxane, methyl-t-butyl ether, tert-butanol, N,N-dimethylacetamide, and N,N-dimethylformamide (DMF).

[0231] Examples of organometallic reagents used in the above scheme (1) include alkyllithium compounds such as methyllithium, n-butyllithium, sec-butyllithium, and t-butyllithium, as well as organoalkali metal compounds such as lithium diisopropylamide, lithium tetramethylpiperidide, lithium hexamethyldisilazide, and potassium hexamethyldisilazide.

[0232] The boron reagents used in the above scheme (1) include boron halides such as boron trifluoride, boron trichloride, boron tribromide, and boron triiodide, as well as boron alkoxylateds and boron aryl oxylateds.

[0233] Examples of Brønsted bases used in the above scheme (1) include N,N-diisopropylethylamine, triethylamine, 2,2,6,6-tetramethylpiperidine, 1,2,2,6,6-pentamethylpiperidine, N,N-dimethylaniline, N,N-dimethyltoluidine, 2,6-lutidine, sodium tetraphenylborate, potassium tetraphenylborate, triphenylborane, tetraphenylsilane, Ar4BNa, Ar4BK, Ar3B, Ar4Si (where Ar is an aryl such as phenyl).

[0234] Examples of Lewis acids used in the above scheme (1) include AlCl3, AlBr3, AlF3, BF3·OEt2, BCl3, BBr3, BI3, GaCl3, GaBr3, InCl3, InBr3, In(OTf)3, SnCl4, SnBr4, AgOTf, ScCl3, Sc(OTf)3, ZnCl2, ZnBr2, Zn(OTf)2, MgCl2, MgBr2, Mg(OTf)2, LiOTf, NaOTf, KOTf, Me3SiOTf, Cu(OTf)2, CuCl2, YCl3, Y(OTf)3, TiCl4, TiBr4, ZrCl4, ZrBr4, FeCl3, FeBr3, CoCl3, CoBr3, etc.

[0235] In the above scheme (1), a Brønsted base or Lewis acid may be used to accelerate the tandem hetero-Friedel-Crafts reaction. However, when using boron halides such as boron trifluoride, boron trichloride, boron tribromide, and boron triiodide, acids such as hydrogen fluoride, hydrogen chloride, hydrogen bromide, and hydrogen iodide are generated as the aromatic electrophilic substitution reaction progresses, so the use of a Brønsted base to capture the acids is effective. On the other hand, when using boron amination halides or boron alkoxyides, amines and alcohols are generated as the aromatic electrophilic substitution reaction progresses, so in most cases, it is not necessary to use a Brønsted base. However, because the leaving ability of aminos and alkoxys is low, the use of a Lewis acid to promote their elimination is effective.

[0236] Furthermore, the polycyclic aromatic compounds of the present invention include those in which at least some hydrogen atoms are substituted with deuterium or halogens such as fluorine or chlorine. Such compounds can be synthesized in the same manner as described above by using raw materials in which the desired portion is deuterated, fluorinated, or chlorinated.

[0237] 2. Organic devices The polycyclic aromatic compounds of the present invention can be used as materials for organic devices. Examples of organic devices include organic field-light-emitting devices, organic field-effect transistors, organic thin-film solar cells, and organic photodiodes. The polycyclic aromatic compounds of the present invention are preferably used as materials for forming one or more organic layers in an organic field-light-emitting device.

[0238] 2-1. Organic electroluminescent devices 2-1-1. Structure of an organic electroluminescent device Figure 1 is a schematic cross-sectional view showing an example of an organic EL element. The organic EL element 100 shown in Figure 1 comprises a substrate 101, an anode 102 provided on the substrate 101, a hole injection layer 103 provided on the anode 102, a hole transport layer 104 provided on the hole injection layer 103, a light-emitting layer 105 provided on the hole transport layer 104, an electron transport layer 106 provided on the light-emitting layer 105, an electron injection layer 107 provided on the electron transport layer 106, and a cathode 108 provided on the electron injection layer 107.

[0239] 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.

[0240] 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.

[0241] 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".

[0242] 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.

[0243] 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.

[0244] The polycyclic aromatic compounds of the present invention are preferably used as materials for forming light-emitting layers or electron transport layers, and more preferably as materials for forming light-emitting layers. The polycyclic aromatic compounds of the present invention can be particularly preferably used as green light-emitting materials.

[0245] 2-1-2. Substrates in Organic Electroluminescent Devices The substrate 101 is a support for the organic EL element 100, and is typically made of quartz, glass, metal, or plastic. Depending on the purpose, the substrate 101 may be formed in the form of a plate, film, or sheet, and examples include glass plates, metal plates, metal foils, plastic films, and plastic sheets. Among these, glass plates and transparent synthetic resin plates such as polyester, polymethacrylate, polycarbonate, and polysulfone are preferred. If a glass substrate is used, soda-lime glass or alkali-free glass may be used, and the thickness should be sufficient to maintain mechanical strength. In addition, to enhance the gas barrier properties, a dense gas barrier film, such as a silicon oxide film, may be provided on at least one side of the substrate 101, and it is particularly preferable to provide a gas barrier film when using a synthetic resin plate, film, or sheet with low gas barrier properties as the substrate 101.

[0246] 2-1-3. Anode in an Organic Electroluminescent Device The anode 102 plays the role of injecting holes into the light-emitting layer 105. If at least one of the hole injection layer 103 and hole transport layer 104 is provided between the anode 102 and the light-emitting layer 105, holes will be injected into the light-emitting layer 105 via these layers.

[0247] 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.

[0248] 2-1-4. Hole injection layer and hole transport layer in organic electroluminescent element The hole injection layer 103 plays the role of efficiently injecting holes moving from the anode 102 into the light-emitting layer 105 or the hole transport layer 104. The hole transport layer 104 plays the role of efficiently transporting holes injected from the anode 102 or holes injected from the anode 102 via the hole injection layer 103 to the light-emitting layer 105. The hole injection layer 103 and the hole transport layer 104 are each formed by laminating or mixing one or more types of hole injection / transport materials. Alternatively, an inorganic salt such as iron(III) chloride may be added to the hole injection / transport material to form a layer.

[0249] 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, it is desirable to have high hole injection efficiency and efficient transport of the injected holes. To achieve this, it is preferable to have a low ionization potential, high hole mobility, excellent stability, and a material that does not easily generate trapping impurities during manufacturing and use.

[0250] 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.

[0251] 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).

[0252] 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.

[0253] 2-1-5. Light-emitting layer in organic electroluminescent device The light-emitting layer 105 is a layer that emits light by recombining holes injected from the anode 102 with electrons injected from the cathode 108 between electrodes to which an electric field is applied. The material forming the light-emitting layer 105 can be any compound (luminescent compound) that emits light when excited by the recombination of holes and electrons. Preferably, a compound is used that can form a stable thin film shape and exhibits strong luminescence (fluorescence) efficiency in the solid state.

[0254] The light-emitting layer may consist of a single layer or multiple layers, each formed from a material for light-emitting layers. If the light-emitting layer consists of multiple layers, it is preferable that at least one of the layers contains the polycyclic aromatic compound of the present invention. It is preferable that the light-emitting layer be a single layer.

[0255] The luminescent layer is formed from luminescent layer materials (host material, dopant material). The host material and dopant material may be one type each, or a combination of multiple types. For example, an emitting dopant and an assisting dopant may be used as the dopant material. It is also preferable that the luminescent layer contains an emitting dopant and at least two materials selected from the group consisting of a hole-transporting host material, an electron-transporting host material, and an assisting dopant material. The dopant material may be contained throughout the host material or partially contained within it. As for the doping method, it can be formed by co-deposition with the host material, or it may be mixed with the host material beforehand and then deposited simultaneously. The luminescent layer can also be formed by a wet film deposition method using a luminescent layer-forming composition prepared by dissolving the material in an organic solvent.

[0256] 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. A 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. If the host material is a combination of a hole-transporting host material and an electron-transporting host material, the amount of host material used is the combined mass of the hole-transporting host material and the electron-transporting host material. The ratio of the amounts of hole-transporting host material to electron-transporting host material should be 1:9 to 9:1 by mass, preferably 4:6 to 6:4, and more preferably approximately 1:1.

[0257] The amount of emitting dopant used varies depending on the type of emitting dopant and should be determined according to its characteristics. A guideline for the amount of emitting dopant used is preferably 0.001 to 50% by mass of the total mass of the luminescent layer material, more preferably 0.05 to 20% by mass, and even more preferably 0.1 to 10% by mass. Within this range, for example, it is preferable in that it can prevent density quenching.

[0258] In organic electroluminescent devices that use an assisting dopant (thermally activated delayed phosphor or phosphorescent material) in addition to an emitting dopant, it is preferable to use a low concentration of the emitting dopant material in order to prevent concentration quenching. A high concentration of the assisting dopant is preferable in terms of energy transfer efficiency. A high concentration of the assisting dopant is also preferable in terms of the efficiency of the thermally activated delayed fluorescence mechanism. In organic electroluminescent devices that use a thermally activated delayed phosphor as the assisting dopant, it is preferable that the amount of emitting dopant used is lower than the amount of assisting dopant in terms of the efficiency of the thermally activated delayed fluorescence mechanism of the assisting dopant.

[0259] 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, based on 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.

[0260] The polycyclic aromatic compound represented by formula (I) is preferably used as a material for forming a light-emitting layer, more preferably as a dopant, and particularly preferably as an emitting dopant.

[0261] The polycyclic aromatic compound represented by formula (I) can be used as an emitting dopant for a TTF device that utilizes the phenomenon of generating singlet excitons from multiple triplet excitons (triplet-triplet fusion (TTF)).

[0262] Furthermore, the polycyclic aromatic compound represented by formula (I) can be used as an emitting dopant for TADF elements as a "thermally activated delayed phosphor." In a "thermally activated delayed phosphor," by reducing the energy difference between the lowest excited singlet state and the lowest excited triplet state, a reverse intersystem crossover from the lowest excited triplet state to the lowest excited singlet state, which normally has a low transition probability, is efficiently generated, resulting in emission from the singlet state (thermally activated delayed fluorescence, TADF). In normal fluorescence emission, 75% of the triplet excitons generated by electric excitation pass through the thermal deactivation pathway and cannot be extracted as fluorescence. On the other hand, with TADF, all excitons can be used for fluorescence emission, enabling the realization of highly efficient organic EL elements.

[0263] Generally, a faster delayed fluorescence (TADF) indicates superior TADF properties. Specifically, when a light-emitting material with a delayed fluorescence lifetime of 100 μsec or less is used as an emitting dopant in a light-emitting device, it can provide high device efficiency and a long device lifetime. A delayed fluorescence lifetime of 20 μsec or less is preferred, less than 20 μsec is more preferred, 10 μsec or less is even more preferred, and 5 μsec or less is most preferred.

[0264] Also, generally speaking, ΔE S1T1 The smaller the value of ΔE, the better the TADF performance. S1T1 This is the lowest excited singlet energy level (E S1 ) and the lowest excited triplet energy level (E T1 This is the energy difference with ). Specifically, ΔE S1T1 The value of is preferably 0.20 eV or less, more preferably 0.15 eV or less, and particularly preferably 0.10 eV or less.

[0265] Furthermore, the polycyclic aromatic compound represented by formula (I) can also be applied to TPSF (phosphor-assisted thermally activated delayed fluorophore-sensitized fluorescence) elements, which use a "thermally activated delayed phosphor" as the host and a phosphorescent material as the assisting dopant.

[0266] <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 distylylbenzene derivatives; tetraphenylbutadiene derivatives; cyclopentadiene derivatives; fluorene derivatives; benzofluorene derivatives; N-phenylcarbazole derivatives; carbazonitrile derivatives; dibenzochrysene derivatives; and compounds described later as hole-transporting or electron-transporting host materials. Furthermore, from the viewpoint of durability, it is preferable that some or all of the hydrogen atoms in the host material are deuterated. Moreover, it is also preferable to construct the luminescent layer by combining a host compound in which some or all of the hydrogen atoms are deuterated with a dopant compound in which some or all of the hydrogen atoms are deuterated.

[0267] 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.

[0268] [Anthracene compounds] Examples of anthracene compounds that can serve as hosts include the compound represented by formula (3-H) and the compound represented by formula (3-H2). [ka]

[0269] In formula (3-H), X and Ar 4 Each is independently hydrogen, a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted diarylamino, an optionally substituted diheteroarylamino, a substituted or unsubstituted arylheteroarylamino, a substituted or unsubstituted alkyl, an optionally substituted cycloalkyl, a substituted or unsubstituted alkenyl, a substituted or unsubstituted alkoxy, a substituted or unsubstituted aryloxy, a substituted or unsubstituted arylthio, or a substituted silyl, and all X and Ar 4They cannot become hydrogen at the same time. At least one hydrogen atom in the compound represented by formula (3-H) may be substituted with a halogen, cyano, deuterium, or an optionally substituted heteroaryl.

[0270] Furthermore, a polymer (preferably a dimer) may be formed using the structure represented by formula (3-H) as the unit structure. In this case, for example, the unit structures represented by formula (3-H) may be bonded together via X, and X may be a single bond, arylene (phenylene, biphenylene, naphthylene, etc.), and heteroarylene (pyridine ring, dibenzofuran ring, dibenzothiophene ring, carbazole ring, benzocarbazole ring, and phenyl-substituted carbazole ring, etc., which are groups having a divalent bond value).

[0271] Details of each group in the compound represented by formula (3-H) can be found by referring to the explanation in formula (I) above, and will be further explained in the section on preferred embodiments below.

[0272] Preferred embodiments of the above anthracene compound are described below. The definitions of the symbols in the following structures are the same as those described above. [ka]

[0273] In formula (3-H), each X is independently a group represented by formula (3-X1), formula (3-X2), or formula (3-X3), and the groups represented by formula (3-X1), formula (3-X2), or formula (3-X3) bond to the anthracene ring of formula (3-H) at *. Preferably, two Xs do not simultaneously become the group represented by formula (3-X3). More preferably, two Xs do not simultaneously become the group represented by formula (3-X2).

[0274] Furthermore, a polymer (preferably a dimer) may be formed using the structure represented by formula (3-H) as the unit structure. In this case, for example, the unit structures represented by formula (3-H) may be bonded together via X, and X may be a single bond, arylene (phenylene, biphenylene, naphthylene, etc.), and heteroarylene (pyridine ring, dibenzofuran ring, dibenzothiophene ring, carbazole ring, benzocarbazole ring, and phenyl-substituted carbazole ring, etc., which are groups having a divalent bond value).

[0275] The naphthylene moieties in formulas (3-X1) and (3-X2) may be condensed with a single benzene ring. The resulting structure is as follows: [ka]

[0276] Ar 1 and Ar 2 Each of these is independently hydrogen, phenyl, biphenylyl, terphenylyl, quaterphenylyl, naphthyl, phenanthryl, fluorenyl, benzofluorenyl, crisenyl, triphenylenyl, pyrenyl, or a group represented by formula (A) (including carbazolyl, benzocarbazolyl, and phenyl-substituted carbazolyl). 1 or Ar 2 If the group is represented by formula (A), then the group represented by formula (A) is bonded to the naphthalene ring in formula (3-X1) or formula (3-X2) at its *.

[0277] Ar 3 This refers to phenyl, biphenylyl, terphenylyl, quaterphenylyl, naphthyl, phenanthryl, fluorenyl, benzofluorenyl, crisenyl, triphenylenyl, pyrenyl, or a group represented by formula (A) (including carbazolyl, benzocarbazolyl, and phenyl-substituted carbazolyl). Note that Ar 3If the group is represented by formula (A), then the group represented by formula (A) bonds with the single bond represented by the line in formula (3-X3) at its *. That is, the anthracene ring of formula (3-H) and the group represented by formula (A) bond directly.

[0278] Also, Ar 3 It may have substituents, Ar 3 At least one hydrogen in may be further substituted with an alkyl group having 1 to 4 carbon atoms, a cycloalkyl group having 5 to 10 carbon atoms, a phenyl group, a biphenylyl group, a terphenylyl group, a naphthyl group, a phenanthryl group, a fluorenyl group, a crisenyl group, a triphenylenyl group, a pyrenyl group, or a group represented by formula (A) (including carbazolyl and phenyl-substituted carbazolyl groups). Note that Ar 3 If the substituent on is the group represented by formula (A), then the group represented by formula (A) is the Ar in formula (3-X3) in its * 3 It combines with it.

[0279] Ar 4 These are silyls that are independently substituted with hydrogen, phenyl, biphenylyl, terphenylyl, naphthyl, or C1-C4 alkyl (methyl, ethyl, t-butyl, etc.) and / or C5-C10 cycloalkyl.

[0280] Examples of alkyl groups with 1 to 4 carbon atoms that can substitute for silyl molecules include methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, t-butyl, and cyclobutyl, with each of the three hydrogen atoms in the silyl molecule being independently substituted by one of these alkyl groups.

[0281] Specific examples of "silyls substituted with alkyl groups having 1 to 4 carbon atoms" include trimethylsilyl, triethylsilyl, tripropylsilyl, triisopropylsilyl, tributylsilyl, trisec-butylsilyl, trit-butylsilyl, ethyldimethylsilyl, propyldimethylsilyl, isopropyldimethylsilyl, butyldimethylsilyl, sec-butyldimethylsilyl, t-butyldimethylsilyl, methyldiethylsilyl, propyldiethylsilyl, isopropyldiethylsilyl, butyldiethylsilyl, sec-butyldiethylsilyl, t-butyldiethylsilyl, methyldipropylsilyl, ethyldipropylsilyl, butyldipropylsilyl, sec-butyldipropylsilyl, t-butyldipropylsilyl, methyldiisopropylsilyl, ethyldiisopropylsilyl, butyldiisopropylsilyl, sec-butyldiisopropylsilyl, and t-butyldiisopropylsilyl.

[0282] Examples of cycloalkyl groups with 5 to 10 carbon atoms that can substitute for silyl include cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl, bicyclo[1.1.1]pentyl, bicyclo[2.1.0]pentyl, bicyclo[2.1.1]hexyl, bicyclo[3.1.0]hexyl, bicyclo[2.2.1]heptyl (norbornyl), bicyclo[2.2.2]octyl, adamantyl, decahydronaphthalenyl, and decahydroazlenyl, where the three hydrogen atoms in the silyl are each independently substituted by one of these cycloalkyl groups.

[0283] Specific examples of "silyls substituted with cycloalkyl groups having 5 to 10 carbon atoms" include tricyclopentylsilyl and tricyclohexylsilyl.

[0284] Substituted silyls include dialkylcycloalkylsilyls, which are substituted with two alkyl groups and one cycloalkyl group, and alkyldicycloalkylsilyls, which are substituted with one alkyl group and two cycloalkyl groups. The groups mentioned above are specific examples of the alkyl and cycloalkyl groups to be substituted.

[0285] Furthermore, the hydrogen atoms in the chemical structure of the anthracene compound represented by formula (3-H) may be substituted with the group represented by formula (A). When substituted with the group represented by formula (A), the group represented by formula (A) substitutes for at least one hydrogen atom in the compound represented by formula (3-H) at that *.

[0286] The group represented by formula (A) is one of the substituents that the anthracene compound represented by formula (3-H) may have. [ka]

[0287] In equation (A), Y is -O-, -S-, or >NR 29 And R 21 ~R 28 Each is independently hydrogen, an optionally substituted alkyl, an optionally substituted cycloalkyl, an optionally substituted aryl, an optionally substituted heteroaryl, an optionally substituted alkoxy, an optionally substituted aryloxy, an optionally substituted arylthio, a trialkylsilyl, a tricycloalkylsilyl, a dialkylcycloalkylsilyl, an alkyldicycloalkylsilyl, an optionally substituted amino, a halogen, a hydroxyl, or a cyano, and R 21 ~R 28 Among these, adjacent groups may be bonded to each other to form a hydrocarbon ring, an aryl ring, or a heteroaryl ring, R 29 is hydrogen or an aryl that may be substituted. In equation (A), Y is preferably -O-.

[0288] R 21 ~R 28Adjacent groups may bond to each other to form a hydrocarbon ring, an aryl ring, or a heteroaryl ring. The group that does not form a ring is represented by formula (A-1) below, while the group that does form a ring is represented by formulas (A-2) to (A-14) below, for example. At least one hydrogen in any of the groups represented by formulas (A-1) to (A-14) may be substituted with alkyl, cycloalkyl, aryl, heteroaryl, alkoxy, aryloxy, arylthio, trialkylsilyl, tricycloalkylsilyl, dialkylcycloalkylsilyl, alkyldicycloalkylsilyl, diaryl (the two aryls may be bonded to each other via a linking group)-substituted amino, diheteroaryl-substituted amino, arylheteroaryl-substituted amino, halogen, hydroxyl, or cyano.

[0289] [ka]

[0290] Examples of rings formed by the bonding of adjacent groups include the cyclohexane ring in the case of hydrocarbon rings, and the aforementioned R in the case of aryl rings and heteroaryl rings. 21 ~R 28 Examples include the ring structures described as "aryl" and "heteroaryl" in formula (A-1), where these rings are formed to condense with one or two benzene rings.

[0291] The group represented by formula (A) is a group obtained by removing one hydrogen atom from any position in formula (A), where * indicates the position. In other words, the group represented by formula (A) may have any position as its bonded position. For example, either carbon atom on the two benzene rings in the structure of formula (A), or R in the structure of formula (A). 21 ~R 28 Among them, any atom on a ring formed by the bonding of adjacent groups to each other, or as Y in the structure of formula (A), ">NR 29 R in " 29 Any position in the middle, or ">NR 29 N(R) in "29 It can be a group that directly bonds with (which forms a bonding site). The same applies to the group represented by any of formulas (A-1) to (A-14).

[0292] Examples of the group represented by formula (A) include any of the groups represented by formulas (A-1) to (A-14), with groups represented by any of formulas (A-1) to (A-5) and formulas (A-12) to (A-14) being preferred, groups represented by any of formulas (A-1) to (A-4) being more preferred, groups represented by any of formulas (A-1), (A-3), and (A-4) being even more preferred, and the group represented by formula (A-1) being particularly preferred.

[0293] Examples of groups represented by formula (A) include the following. The definitions of Y and * in the formula are the same as above. [ka]

[0294] [ka]

[0295] In the compound represented by formula (3-H), the group represented by formula (A) is the naphthalene ring in formula (3-X1) or formula (3-X2), the single bond in formula (3-X3), and the Ar in formula (3-X3). 3 A form in which it is combined with one of the following is preferred.

[0296] Furthermore, all or part of the hydrogen atoms in the chemical structure of the anthracene compound represented by formula (3-H) may be deuterium.

[0297] The anthracene compound used as a host may be, for example, a compound represented by the following formula (3-H2). [ka]

[0298] In formula (3-H2), Ar c R is an optionally substituted aryl or optionally substituted heteroaryl, c is hydrogen, alkyl, or cycloalkyl, and Ar 11 Ar 12 Ar 13 Ar 14 Ar 15 Ar 16 Ar 17 , and Ar 18 Each of these is independently a hydrogen, an optionally substituted aryl, an optionally substituted heteroaryl, an optionally substituted diarylamino, an optionally substituted diheteroarylamino, an optionally substituted arylheteroarylamino, an optionally substituted alkyl, an optionally substituted cycloalkyl, an optionally substituted alkenyl, an optionally substituted alkoxy, an optionally substituted aryloxy, an optionally substituted arylthio, or an optionally substituted silyl, wherein at least one hydrogen in the compound represented by formula (3-H2) may be substituted with a halogen, cyano, or deuterium.

[0299] The definitions of "optionally substituted aryl," "optionally substituted heteroaryl," "optionally substituted diarylamino," "optionally substituted diheteroarylamino," "optionally substituted arylheteroarylamino," "optionally substituted alkyl," "optionally substituted cycloalkyl," "optionally substituted alkenyl," "optionally substituted alkoxy," "optionally substituted aryloxy," "optionally substituted arylthio," or "optionally substituted silyl" in formula (3-H) are the same as those shown in formula (3-H) above, and the explanation in formula (3-H) can be referenced.

[0300] The "aryl group that may be substituted" is preferably a group represented by any of the following formulas (3-H2-X1) to (3-H2-X8).

[0301] [ka]

[0302] In equations (3-H2-X1) to (3-H2-X8), * indicates the bond position. In equations (3-H2-X1) to (3-H2-X3), Ar 21 Ar 22 , and Ar 23 Each of these is independently hydrogen, phenyl, biphenylyl, terphenylyl, quaterphenylyl, naphthyl, phenanthryl, fluorenyl, benzofluorenyl, crisenyl, triphenylenyl, pyrenyl, anthracenyl, or a group represented by formula (A). In the explanation of formula (3-H2), the group represented by formula (A) is the same as that explained for the anthracene compound represented by formula (3-H).

[0303] In equations (3-H2-X4) to (3-H2-X8), Ar 24 Ar 25 Ar 26 Ar 27 Ar 28 Ar 29 , and Ar 30 Each of these is independently hydrogen, phenyl, biphenylyl, terphenylyl, naphthyl, phenanthryl, fluorenyl, crisenyl, triphenylenyl, pyrenyl, or a group represented by formula (A). In addition, one or more hydrogens in each of the groups represented by formulas (3-H2-X1) to (3-H2-X8) may be substituted with an alkyl group having 1 to 6 carbon atoms (preferably methyl or t-butyl).

[0304] Furthermore, preferred examples of "optionally substituted aryls" include terpheniryl (in particular m-terphenyl-5'-yl), which may be substituted with one or more substituents selected from the group consisting of phenyl, biphenylyl, terphenylyl, naphthyl, phenanthryl, fluorenyl, crisenyl, triphenylenyl, pyrenyl, and the group represented by formula (A).

[0305] Examples of "optionally substituted heteroaryls" include the group represented by formula (A). Other specific examples of "optionally substituted aryls" and "optionally substituted heteroaryls" include dibenzofuryl, naphthobenzofuryl, and phenyl-substituted dibenzofuryl.

[0306] At least one hydrogen atom in the compound represented by formula (3-H2) may be substituted with a halogen, cyanopropyl alcohol, or deuterium. Examples of halogens in this case include fluorine, chlorine, bromine, and iodine. Compounds in which all hydrogen atoms in the compound represented by formula (3-H2) are substituted with deuterium are particularly preferred.

[0307] In formula (3-H2), R c The element is hydrogen, alkyl, or cycloalkyl, preferably hydrogen, methyl, or t-butyl, and more preferably hydrogen. In formula (3-H2), Ar 11 ~Ar 18 Preferably, at least two of the substituents are optionally substituted aryl or optionally substituted heteroaryl. That is, the anthracene compound represented by formula (3-H2) preferably has a structure in which at least three substituents selected from the group consisting of optionally substituted aryl and optionally substituted heteroaryl are bonded to the anthracene ring.

[0308] Anthracene compounds represented by formula (3-H2) are Ar 11 ~Ar 18It is more preferable that two of the substituents are optionally substituted aryl or optionally substituted heteroaryl, and the other six substituents are hydrogen, optionally substituted alkyl, optionally substituted cycloalkyl, optionally substituted alkenyl, or optionally substituted alkoxy. In other words, it is more preferable that the anthracene compound represented by formula (3-H2) has a structure in which three substituents selected from the group consisting of optionally substituted aryl and optionally substituted heteroaryl are bonded to the anthracene ring.

[0309] Anthracene compounds represented by formula (3-H2) are Ar 11 ~Ar 18 It is more preferable that any two of the elements are optionally substituted aryl or optionally substituted heteroaryl, and the other six are hydrogen, methyl, or t-butyl.

[0310] Furthermore, in equation (3-H2), R c is hydrogen and Ar 11 ~Ar 18 It is preferable that any six of them are hydrogen.

[0311] The anthracene compound represented by formula (3-H2) is preferably an anthracene compound represented by the following formulas: (3-H2-A), (3-H2-B), (3-H2-C), (3-H2-D), or (3-H2-E). [ka]

[0312] In formulas (3-H2-A), (3-H2-B), (3-H2-C), (3-H2-D), or (3-H2-E), Ar c ', Ar 11 ', Ar 12 ', Ar 13 ', Ar 14 ', Ar 15 ', Ar 17 ', and Ar 18Each of the following groups is independently phenyl, biphenylyl, terphenylyl, quaterphenylyl, naphthyl, phenanthryl, fluorenyl, benzofluorenyl, crisenyl, triphenylenyl, pyrenyl, or a group represented by formula (A), and at least one hydrogen in these groups may be substituted with phenyl, biphenylyl, terphenylyl, quaterphenylyl, naphthyl, phenanthryl, fluorenyl, benzofluorenyl, crisenyl, triphenylenyl, pyrenyl, or a group represented by formula (A). Here, when both the hydrogen of the methylene group in fluorenyl and benzofluorenyl are substituted with phenyl, these phenyl groups may be bonded to each other by single bonds. c ', Ar 11 ', Ar 12 ', Ar 13 ', Ar 14 ', Ar 15 ', Ar 17 ', and Ar 18 The carbon atoms of the anthracene ring that are not bonded may have methyl or t-butyl atoms bonded to them instead of hydrogen atoms.

[0313] Ar c ', Ar 11 ', Ar 12 ', Ar 13 ', Ar 14 ', Ar 15 ', Ar 17 ', and Ar 18 When each of these is a substituted or unsubstituted phenyl or a substituted or unsubstituted naphthyl, it is preferable that the group is represented by any of the above formulas (3-H2-X1) to (3-H2-X8).

[0314] Ar c ', Ar 11 ', Ar 12 ', Ar 13 ', Ar 14 ', Ar 15 ', Ar 17 ', and Ar 18Each of the groups is more preferably independently phenyl, biphenylyl (especially biphenyl-2-yl or biphenyl-4-yl), terphenylyl (especially m-terphenyl-5'-yl), naphthyl, phenanthryl, fluorenyl, or any of the above formulas (A-1) to (A-4), in which case at least one hydrogen in these groups may be substituted with phenyl, biphenylyl, naphthyl, phenanthryl, fluorenyl, or any of the above formulas (A-1) to (A-4).

[0315] Furthermore, at least one hydrogen atom in the compounds represented by formulas (3-H2-A), (3-H2-B), (3-H2-C), (3-H2-D), or (3-H2-E) may be substituted with a halogen, cyano, or deuterium. Deuterated forms are preferred, and forms in which the entire anthracene ring is deuterated, or forms in which all hydrogen atoms are deuterated, are preferred.

[0316] Particularly preferred anthracene compounds represented by the formula (3-H2) include the anthracene compounds represented by the following formula (3-H2-Aa). [ka]

[0317] In formula (3-H2-Aa), Ar c ', Ar 14 ', and Ar 15Each of the following groups is independently phenyl, biphenylyl, terphenylyl, naphthyl, phenanthryl, fluorenyl, benzofluorenyl, crisenyl, triphenylenyl, pyrenyl, or any of the above formulas (A-1) to (A-11), and at least one hydrogen in these groups may be substituted with phenyl, biphenylyl, terphenylyl, naphthyl, phenanthryl, fluorenyl, benzofluorenyl, crisenyl, triphenylenyl, pyrenyl, or any of the above formulas (A-1) to (A-11). Here, when both the hydrogen of the methylene group in fluorenyl and benzofluorenyl are substituted with phenyl, these phenyl groups may be bonded to each other by single bonds. Also, Ar c ', Ar 14 ', and Ar 15 Carbon atoms on the anthracene ring that are not bonded to a hydrogen atom may be substituted with methyl or t-butyl instead of hydrogen. At least one hydrogen atom in the compound represented by formula (3-H2-Aa) may be substituted with a halogen or cyano, and preferably at least one hydrogen atom in the compound represented by formula (3-H2-Aa) is substituted with deuterium.

[0318] In formula (3-H2-Aa), Ar c ', Ar 14 ', and Ar 15 Each of the groups is preferably independently phenyl, biphenylyl, terphenylyl, naphthyl, phenanthryl, fluorenyl, or any of the groups represented by formulas (A-1) to (A-4) above, and at least one hydrogen in these groups may be substituted with phenyl, naphthyl, phenanthryl, fluorenyl, or any of the groups represented by formulas (A-1) to (A-4).

[0319] In the compound represented by formula (3-H2-Aa), at least the carbon at position 10 of the anthracene ring (Ar cIt is preferable that the hydrogen bonded to the carbon atom to which the ' is attached (with the carbon atom at position 9) is substituted with deuterium. That is, the compound represented by formula (3-H2-Aa) is preferably the compound represented by the following formula (3-H2-Ab). In formula (3-H2-Ab), D is deuterium, and Ar c ', Ar 14 ', and Ar 15 ' is the same as the definition in formula (3-H2-Aa). In formula (3-H2-Ab), D indicates that at least this position is deuterium, and one or more of the other hydrogens in formula (3-H2-Ab) may also be deuterium, and it is also preferable that all of the hydrogens in formula (3-H2-Ab) are deuterium.

[0320] [ka]

[0321] Specific examples of anthracene compounds include, for example, the compounds represented by formulas (3-131-Y) to (3-182-Y), (3-183-N), (3-184-Y) to (3-284-Y), and (3-500) to (3-557), and (3-600) to (3-605), and (3-606-Y) to (3-626-Y). The hydrogen atoms in these formulas may be partially or entirely substituted with deuterium, but particularly preferred forms of deuterium substitution are listed separately. In the formulas, Y represents -O-, -S-, >NR. 29 (R 29 (This is the same definition as above) or >C(-R 30 )2(R 30 R may be either an aryl or alkyl group that is linked, 29 For example, phenyl, R 30 For example, methyl. The formula numbering is as follows: for example, if Y is O, formula (3-131-Y) becomes formula (3-131-O), and Y is -S- or >NR. 29 In these cases, the equations are (3-131-S) or (3-131-N), respectively.

[0322]

change

[0323]

change

[0324]

change

[0325]

change

[0326]

change

[0327]

change

[0328]

change

[0329]

change

[0330]

change

[0331]

change

[0332]

change

[0333] [ka]

[0334] [ka]

[0335] [ka]

[0336] [ka]

[0337] [ka]

[0338] [ka]

[0339] [ka]

[0340] [ka]

[0341] [ka] In the above formula, D is deuterium.

[0342] Among these compounds, formulas (3-131-Y)~(3-134-Y), formula (3-138-Y), formula (3-140-Y)~(3-143-Y), formula (3-150-Y), formula (3-153-Y)~(3-156-Y), formula (3-166-Y), formula (3-168-Y), formula (3-173-Y), formula (3-177-Y), formula (3-180-Y)~(3-183-N), formula (3-185-Y), formula (3-190-Y), formula (3-223-Y), formula (3-241- Compounds represented by formulas (Y), (3-250-Y), (3-252-Y) to (3-254-Y), (3-270-Y) to (3-284-Y), (3-501), (3-507), (3-508), (3-509), (3-513), (3-514), (3-519), (3-521), (3-538) to (3-547), or (3-600) to (3-605), and (3-606-Y) to (3-626-Y) are preferred. Furthermore, Y is -O- or >NR 29 It is preferable that it is -O-, and more preferably that it is deuterium-substituted. The deuterium substitution form is also preferred.

[0343] The above anthracene compounds include compounds having a reactive group at a desired position on the anthracene skeleton, and anthracene compounds represented by formula (3-H), where X and Ar 4 The compounds can be produced by applying Suzuki coupling, Negishi coupling, or other known coupling reactions, using compounds having reactive groups in substructures such as the structure of formula (A) as starting materials. Examples of reactive groups in these reactive compounds include halogens and boronic acids. For specific production methods, refer to the synthesis methods in paragraphs

[0089] to

[0175] of International Publication No. 2014 / 141725, for example.

[0344] [Fluorene compounds] The compound represented by formula (4-H) basically functions as a host. [ka]

[0345] In formula (4-H), R 1 From R 10 Each of these is independently a hydrogen, an aryl, a heteroaryl (the heteroaryl may be bonded to the fluorene skeleton in formula (4-H) via a single bond or a linking group), a diarylamino, a diheteroarylamino, an arylheteroarylamino, an alkyl, a cycloalkyl, an alkenyl, an alkoxy, or an aryloxy, wherein at least one hydrogen in these may be substituted with an aryl, heteroaryl, alkyl, or cycloalkyl, and R 1 and R 2 , R 2 and R 3 , R 3 and R 4 , R 5 and R 6 , R 6 and R 7 , R 7 and R 8 or R 9 and R 10 Each of these may be independently bonded to form a fused ring or spiro ring, and at least one hydrogen in the formed ring may be substituted with an aryl, heteroaryl (the heteroaryl may be bonded to the formed ring via a single bond or a linking group), diarylamino, diheteroarylamino, arylheteroarylamino, alkyl, cycloalkyl, alkenyl, alkoxy, or aryloxy, and at least one hydrogen in these may be substituted with an aryl, heteroaryl, alkyl, or cycloalkyl, and at least one hydrogen in the compound represented by formula (4-H) may be substituted with a halogen, cyano, or deuterium.

[0346] For details of each group in the definition of formula (4-H), refer to the explanation in formula (I) above.

[0347] R 1 From R 10Examples of alkenyls include alkenyls having 2 to 30 carbon atoms, with alkenyls having 2 to 20 carbon atoms being preferred, alkenyls having 2 to 10 carbon atoms being more preferred, alkenyls having 2 to 6 carbon atoms being even more preferred, and alkenyls having 2 to 4 carbon atoms being particularly preferred. Preferred alkenyls are vinyl, 1-propenyl, 2-propenyl, 1-butenyl, 2-butenyl, 3-butenyl, 1-pentenyl, 2-pentenyl, 3-pentenyl, 4-pentenyl, 1-hexenyl, 2-hexenyl, 3-hexenyl, 4-hexenyl, or 5-hexenyl.

[0348] Furthermore, as specific examples of heteroaryls, monovalent groups can also be given, which are represented by removing any one hydrogen atom from the compounds of the following formulas: (4-Ar1), (4-Ar2), (4-Ar3), (4-Ar4), or (4-Ar5).

[0349] [ka]

[0350] In equations (4-Ar1) to (4-Ar5), Y 1 Each of these is independently O, S, or NR, where R is phenyl, biphenylyl, naphthyl, anthracenyl, or hydrogen, and at least one hydrogen in the structures of formulas (4-Ar1) to (4-Ar5) may be substituted with phenyl, biphenylyl, naphthyl, anthracenyl, phenanthryl, methyl, ethyl, propyl, or butyl.

[0351] These heteroaryls may be bonded to the fluorene skeleton in formula (4-H) via single bonds or linking groups. That is, the fluorene skeleton in formula (4-H) and the heteroaryls may not only be directly bonded, but may also be bonded to each other via single bonds or linking groups. Examples of such linking groups include phenylene, biphenylene, naphthylene, anthracenylene, methylene, ethylene, -OCH2CH2-, -CH2CH2O-, or -OCH2CH2O-.

[0352] Also, R in equation (4-H) 1 and R 2 , R 2 and R 3 , R 3 and R 4 , R 5 and R 6 , R 6 and R 7 or R 7 and R 8 Each of them independently bonds to form a fused ring, R 9 and R 10 They may be bonded together to form a spiro ring. 1 From R 8 The condensed ring formed by this process is a ring that condenses with the benzene ring in formula (4-H), and is either an aliphatic or aromatic ring. Preferably, it is an aromatic ring, and examples of structures including the benzene ring in formula (4-H) include naphthalene rings and phenanthrene rings. 9 and R 10 The spiro ring formed by this process is a ring that spirobonds to the 5-membered ring in formula (4-H), and is either an aliphatic or aromatic ring. Preferably, it is an aromatic ring, such as a fluorene ring.

[0353] The compound represented by formula (4-H) is preferably a compound represented by the following formulas (4-H-1), (4-H-2), or (4-H-3), where in each case R in formula (4-H) 1 and R 2 A compound in which a benzene ring formed by the bonding of R is condensed, in formula (4-H). 3 and R 4 A compound in which a benzene ring formed by the bonding of R is condensed, in formula (4-H). 1 From R 8 It is a compound in which none of the following are bonded.

[0354] [ka]

[0355] R in equations (4-H-1), (4-H-2), and (4-H-3) 1From R 10 The definition of is the corresponding R in equation (4-H). 1 From R 10 This is the same as R in equations (4-H-1) and (4-H-2). 11 From R 14 The definition of R in equation (4-H) is also 1 From R 10 It is the same as this.

[0356] The compound represented by formula (4-H) is more preferably the compound represented by the following formulas (4-H-1A), (4-H-2A), or (4-H-3A), where R is present in formulas (4-H-1), (4-H-2), or (4-H-3), respectively. 9 and R 10 This is a compound in which a spirofluorene ring is formed by the bonding of two molecules.

[0357] [ka]

[0358] R in equations (4-H-1A), (4-H-2A), and (4-H-3A) 2 From R 7 The definition of is the corresponding R in equations (4-H-1), (4-H-2), and (4-H-3). 2 From R 7 This is the same as R in equations (4-H-1A) and (4-H-2A). 11 From R 14 The definition of R in equations (4-H-1) and (4-H-2) is also 11 From R 14 It is the same as this.

[0359] Furthermore, in the compound represented by formula (4-H), all or part of the hydrogen atoms may be substituted with halogens, cyanosides, or deuterium.

[0360] More specific examples of fluorene compounds as hosts include the compounds represented by the following structural formula. [ka]

[0361] [Compounds represented by any of the formulas (H1), (H2), and (H3)] As a host material, for example, a compound represented by any of the following formulas (H1), (H2), and (H3) can be used. [ka]

[0362] In formulas (H1), (H2), and (H3), L 1 L is a divalent group containing a single bond or at least an arylene or heteroarylene. Specifically, L 1 It can be a single bond, or a divalent group formed by linking any two of the following with -O-, -S-, -CH2-, -Si(-Arx)2- (Arx is aryl), or cycloalkylene. 1 The arylene used is preferably one with 6 to 16 carbon atoms, more preferably one with 6 to 12 carbon atoms, and particularly preferably one with 6 to 10 carbon atoms. Specifically, divalent groups such as benzene rings, biphenyl rings, terphenyl rings, and fluorene rings are used. 1The heteroarylenes included are preferably heteroarylenes having 2 to 24 carbon atoms, more preferably heteroarylenes having 2 to 20 carbon atoms, even more preferably heteroarylenes having 2 to 15 carbon atoms, and particularly preferably heteroarylenes having 2 to 10 carbon atoms. Specifically, these include pyrrole rings, oxazole rings, isoxazole rings, thiazole rings, isothiazole rings, imidazole rings, oxadiazole rings (such as furazan rings), thiadiazole rings, triazole rings, tetrazole rings, pyrazole rings, pyridine rings, pyrimidine rings, pyridazine rings, pyrazine rings, triazine rings, indole rings, and isoindole rings. Examples of divalent groups include 1H-indazole rings, benzimidazole rings, benzoxazole rings, benzothiazole rings, 1H-benzotriazole rings, quinoline rings, isoquinoline rings, sinnoline rings, quinazoline rings, quinoxaline rings, phthalazine rings, naphthyridine rings, purine rings, pteridine rings, carbazole rings, acridine rings, phenoxatiin rings, phenoxazine rings, phenothiazine rings, phenazine rings, indidine rings, furan rings, benzofuran rings, isobenzofuran rings, dibenzofuran rings, thiophene rings, benzothiophene rings, dibenzothiophene rings, and thianthlene rings. At least one hydrogen atom in each of the compounds represented by the above formulas may be substituted with at least one group selected from substituent group Z or with deuterium, for example, with an alkyl, cyano, halogen or deuterium having 1 to 6 carbon atoms.

[0363] Preferred specific examples include compounds represented by any of the structural formulas listed below. In the structural formulas listed below, at least one hydrogen atom may be substituted with a halogen, cyano, a C1-C4 alkyl group (e.g., methyl or t-butyl), phenyl, or naphthyl.

[0364] [ka]

[0365] [ka]

[0366] [ka]

[0367] [ka]

[0368] [Hole-transporting host materials (HH) and electron-transporting host materials (EH)] Hole-transporting host materials (HH) and electron-transporting host materials (EH) satisfy the following relationship with respect to HOMO (Highest Occupied Molecular Orbital) and LUMO (Lowest Unoccupied Molecular Orbital). The homeosphere of a hole-transporting host material (HH) is shallower than that of an electron-transporting host material (EH), and the lumen-luminosity of an electron-transporting host material (EH) is deeper than that of a hole-transporting host material (HH). Furthermore, it is preferable that the HOMO of the emitting dopant is shallower than the HOMO of the hole-transporting host material (HH), or that the LUMO of the emitting dopant is deeper than the LUMO of the electron-transporting host material (EH).

[0369] Furthermore, the lowest excited triplet energy level (E) of hole-transporting host materials (HH) and electron-transporting host materials (EH) T1 ) is chosen from the viewpoint of promoting the generation of TADF within the light-emitting layer without inhibiting it, and is the highest E within the light-emitting layer. T1 Emitting dopant or assisting dopant having E T1 It is preferable that it be higher than the E of the host material. Specifically, the E of the host material T1 This refers to the E of the above-mentioned emitting dopant or assisting dopant. T1 It is preferable that it is 0.01 eV or more higher than, more preferably 0.03 eV or more higher, and even more preferably 0.1 eV or more higher than. Also, the E of the host material T1The voltage is preferably 2.47 eV or higher, more preferably 2.49 eV or higher, and even more preferably 2.56 eV or higher.

[0370] 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.

[0371] Examples of preferred hole-transporting host materials (HH) include compounds represented by formula (HH-1) or having a substructure represented by formula (HH-1) and containing at least three rings selected from the group consisting of aryl rings and heteroaryl rings. It is preferable that these compounds do not contain any imine structure (-N=C-; including a heteroaryl ring substructure), boron (>B-), or cyano (CN). These compounds may also be used as host materials on their own.

[0372] [ka]

[0373] In equation (HH-1), Q is either >O, >S, or >NA H And, In formula (HH-1), the carbon atom adjacent to the carbon atom to which Q is bonded in each of the two phenyl molecules may be bonded to each other by L. L is a single bond, >O, >S, or >C(-A) H )2, A H is hydrogen, aryl, or heteroaryl, and >C(-A H )2 A HThey may be bound to each other.

[0374] When a hole-transporting host material contains a substructure represented by formula (HH-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 substructures may further have substituents selected from aryl, heteroaryl, diarylamino, or aryloxy.

[0375] Compounds represented by the above formula (HH-1), or having a substructure represented by the formula (HH-1), have a structure containing at least three rings selected from the group consisting of aryl rings and heteroaryl rings. The number of rings is preferably 6 or more, more preferably 8 or more. It is also preferably 20 or less, more preferably 15 or less, and even more preferably 10 or less. The number of rings refers to the number of monorings; for fused rings, it refers to the number of monorings constituting the fused ring.

[0376] 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, 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.

[0377] Specific examples of hole-transporting host materials include the following compounds. [ka]

[0378]

change

[0379]

change

[0380]

change

[0381]

change

[0382]

change

[0383]

change

[0384]

change

[0385]

change

[0386]

change

[0387]

change

[0388]

change

[0389] [ka]

[0390] Of the above, HH-1-1, HH-1-2, HH-1-4 to HH-1-12, HH-1-17, HH-1-18, HH-1-20 to HH-1-24, HH-1-82, HH-1-84 to HH-1-89, HH-1-91, HH-1-92, HH-1-106 to HH-1-108, and HH-1-109 to HH-1-115 are preferred.

[0391] Examples of electron-transporting host materials (EH) include compounds represented by formulas (EH-1A) to (EH-1D), or compounds having a substructure represented by formulas (EH-1A) to (EH-1D) and containing at least three rings selected from the group consisting of aryl rings and heteroaryl rings. These compounds may also be used as host materials on their own.

[0392] [ka]

[0393] In equations (EH-1A) to (EH-1D), Ar is a heteroaryl ring that contains N=C as a substructure constituting the ring. Z is a single bond, -O-, -S-, or -N(-A) E )- and, A is bonded to the carbon atom adjacent to the carbon atom that is bonded to Z. E These can be connected by L, L is a single bond, >O, >S, or >C(-A) E )2, A E is an aryl, heteroaryl, or triarylsilyl, and in formula (EH-1C), any one of the A's is present. E It may also be a diarylamino, Two A atoms bonded to the same atom E They may be connected to each other by L, X is C, P, or S. When X is C, n=2 and m=1, When X is P, n=3 and m=1, When X is S, n=2 and m=1 to 2.

[0394] Compounds represented by the above formulas (EH-1A) to (EH-1D), or compounds having substructures represented by the above formulas (EH-1A) to (EH-1D), have a structure containing at least three rings selected from the group consisting of aryl rings and heteroaryl rings. The number of rings is preferably 4 or more, more preferably 6 or more, and even more preferably 8 or more. It is also preferably 20 or less, more preferably 15 or less, and even more preferably 10 or less. The number of rings refers to the number of monorings; for fused rings, it refers to the number of monorings constituting the fused ring.

[0395] When an electron-transporting host material contains a substructure represented by formulas (EH-1A) to (EH-1D), it may contain one substructure, but it is also preferable to contain two or more. If it contains two or more substructures, they may be the same or different from each other. The two or more substructures may be bonded to each other by single bonds, bonded so as to share any ring contained in the substructure, or bonded so as to be fused to any ring contained in the substructure. The substructures may further have substituents selected from aryl, heteroaryl, diarylamino, or aryloxy.

[0396] The following compounds are specific examples of electron-transporting host materials. [ka]

[0397] [ka]

[0398] [ka]

[0399] [ka]

[0400] [ka]

[0401] [ka]

[0402] [ka]

[0403] [ka]

[0404] [ka]

[0405] As electron-transporting host materials, polycyclic aromatic compounds represented by the following formula (EH-1b), or polymers of polycyclic aromatic compounds having multiple structures represented by the following formula (EH-1b), are also preferred. [ka]

[0406] In equation (EH-1b), R 1 , R 2 , R 3 , R 4and R 5 (Hereinafter referred to as “R 1 Each of these (also called "etc.") is independently either a hydrogen atom or a substituent. This substituent can be any substituent selected from substituent group Z. In equation (EH-1b), X 1 and X 2 These are, independently, >NR (amine nitrogen), >O, >C(-R)2, >S, or >Se, and X 1 and X 2 It is not possible for both to be >C(-R)2. In >NR and >C(-R)2, R is independently hydrogen or a substituent selected from substituent group Z, and may further be substituted with aryl, heteroaryl, alkyl, or cycloalkyl (the above are secondary substituents), and R in >NR and >C(-R)2 may independently be bonded to at least one of the a, b, and c rings by a linking group or a single bond. Y 1 , Y 2 , Y 3 , Y 4 , Y 5 and Y 6 (From here on, "Y 1 Each of these (also called "etc.") is independently either =C(-R)- or =N- (pyridine nitrogen), and at least one is =N- (pyridine nitrogen), In the above-mentioned =C(-R)-, R is independently selected from hydrogen or the substituent group Z. The aforementioned R 1 , R 2 , R 3 , R 4 and R 5 , and also, the Y 1 ~Y 6As =C(-R)-, adjacent R groups may bond together to form an aryl ring or heteroaryl ring with at least one of the a, b, and c rings, and at least one hydrogen in the formed ring may be substituted with aryl, heteroaryl, diarylamino, diheteroarylamino, arylheteroarylamino, diarylboryl (the two aryls may be bonded via a single bond or a linking group), alkyl, cycloalkyl, alkoxy or aryloxy (the above are the first substituents), and at least one hydrogen in these may be further substituted with aryl, heteroaryl, alkyl or cycloalkyl (the above are the second substituents). At least one hydrogen atom in the compound and structure represented by formula (EH-1b) may be substituted with cyano, halogen, or deuterium.

[0407] In equation (EH-1b), R 1 , R 2 , R 3 , R 4 and R 5 Both are hydrogen, or R 3 and R 4 Both are hydrogen, and R 1 , R 2 and R 5Preferably, one or more substituents selected from the group consisting of are other than hydrogen, and the others are hydrogen. Preferred substituents are alkyl, aryl which may be substituted with alkyl or heteroaryl, heteroaryl which may be substituted with alkyl or aryl, or diarylamino which may be substituted with alkyl or aryl. In this case, preferred alkyl is a C1-C6 alkyl (methyl, t-butyl, etc.), preferred aryl is phenyl or biphenyl, and preferred heteroaryl is triazinyl, carbazolyl (2-carbazolyl, 3-carbazolyl, 9-carbazolyl, etc.), pyrimidinyl, pyridinyl, dibenzofuranyl, or dibenzothienyl. Specific examples include phenyl, biphenyl, diphenyltriazinyl, carbazolyltriazinyl, monophenylpyrimidinyl, diphenylpyrimidinyl, carbazolyltriazinyl, pyridinyl, dibenzofuranyl, and dibenzothienyl.

[0408] Y 1 Each of these is independently =C(-R)- or =N-, and at least one of them is =N-. 1 ~Y 6 Either of these can be =N-. Preferably, Y 1 and Y 6 ga = N-(a ring is a pyrimidine ring), Y 1 or Y 6 ga = N-(a ring is a pyridine ring), Y 2 and Y 5 ga = N-(b-ring and c-ring are pyridine rings), Y 3 and Y 4 ga = N-(b-ring and c-ring are pyridine rings), Y 2 ~Y 5 ga = N-(b-ring and c-ring are pyrimidine rings), Y 1 , Y 3 , Y 4 and Y 6 ga = N - (a ring is a pyrimidine ring, b ring and c ring are pyridine rings), Y 1 , Y 2 , Y 5 and Y 6ga = N - (a ring is a pyrimidine ring, b ring and c ring are pyridine rings), Y 1 ~Y 6 ga = N - (a, b, and c rings are pyrimidine rings), Y 2 or Y 5 The formula is N-(where the b-ring or c-ring is a pyridine ring).

[0409] 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]

[0410] 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 has. Specific examples of polycyclic aromatic compounds represented by formula (EH-1b) are shown below.

[0411] [ka]

[0412] [ka]

[0413] [ka]

[0414] [ka]

[0415] [ka]

[0416] [ka]

[0417] Of the above, EH-1-1 to EH-1-4, EH-1-10, EH-1-21 to EH-1-25, EH-1-32, EH-1-33, EH-1-51 to EH-1-59, EH-1-61, EH-1-66, EH-1-68, EH-1-71, EH-1-72, EH-1-90, EH-1-94 to EH-1-99, EH-1-100, EH-1-101, EH-1-104, EH-1-115, EH-1-117, EH-1-120, EH-1-122, EH-1-123, and EH-1-127 to EH-1-130 are preferred.

[0418] [Combination of hole-transporting host material and electron-transporting host material] The combination of hole-transporting host material and electron-transporting host material results in the HOMO, LUMO, and lowest excited triplet energy levels (E) of the hole-transporting host material, electron-transporting host material, and dopant material. T1 ) is selected by. 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.

[0419] 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.

[0420] The following are specific examples of combinations of hole-transporting host materials and electron-transporting host materials that do not form an excyplex: HOMO, LUMO and E T1 To satisfy the physical properties, in hole-transporting host materials, compounds having carbazole, dibenzofuran, dibenzothiophene, triarylamine, indolocarbazole, 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, in 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.

[0421] 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.

[0422] The following are specific examples of combinations of hole-transporting host materials and electron-transporting host materials that form an excyplex: HOMO, LUMO, and E T1To satisfy the physical properties, in hole-transporting host materials, compounds having carbazole, triarylamine, indolocarbazole, and benzoxazinophenoxazine as substructures are preferred, compounds having triarylamine, indolocarbazole, and benzoxazinophenoxazine as substructures are more preferred, and compounds having triarylamine as a substructure are even more preferred. Similarly, in electron-transporting host materials, compounds having pyridine, triazine, phosphine oxide, and benzoflopyridine as substructures are preferred, compounds having triazine, phosphine oxide, benzoflopyridine, and dibenzoxacillin as substructures are more preferred, and compounds having phosphine oxide and triazine are even more preferred.

[0423] More specifically, the hole-transporting host material is preferably selected from the group consisting of HH-1-1, HH-1-2, HH-1-11, HH-1-12, HH-1-17, HH-1-18, HH-1-23, HH-1-24, and HH-1-115, and the electron-transporting host material is preferably EH-1-1 to EH-1-4, EH-1-21 to EH-1-25, and EH-1-5 It is preferable to select from the group consisting of 1 to EH-1-57, EH-1-59, EH-1-66, EH-1-68, EH-1-90, EH-1-94, EH-1-99, EH-1-100, EH-1-101, EH-1-104, EH-1-117, EH-1-120, EH-1-122, EH-1-123, and EH-1-127 to EH-1-130. Preferred combinations include compound HH-1-1 and compound EH-1-21, compound HH-1-2 and compound EH-1-21, compound HH-1-12 and compound EH-1-94, compound HH-1-12 and compound EH-1-117, compound HH-1-1 and compound EH-1-130, compound HH-1-33 and compound EH-1-117, compound HH-1-48 and compound EH-1-117, compound HH-1-49 and compound EH-1-117, or compound HH-1-115 and compound EH-1-99.

[0424] For further information on specific combinations of hole-transporting and electron-transporting host materials, please refer to: Organic Electronics 66(2019)227-24, Advanced Functional Materials 25(2015)361-366, Advanced Materials 26(2014)4730-4734, ACS Applied Materials and Interfaces 8(2016)32984-32991, ACS Applied Materials and Interfaces 2016,8,9806-9810, ACS Applied Materials and Interfaces 2016,8,32984-32991, Journal of Materials Chemistry C,2018,6,8784-8792, Angewante Chemie International Edition.2018,57,12380-12384, Advanced Functional Materials,24,2014,3970,Advanced See also the descriptions in Materials, 26, 2014, 5684, Synthetic Metals, 201, 2015, 49, and Nature Photonics, 16, 212-218 (2022).

[0425] <Assisting dopant (thermally activated delayed phosphor or phosphorescent material)> The light-emitting layer may also preferably contain an assisting dopant along with the emitting dopant and host material. A thermally activated delayed phosphor or a phosphorescent material is preferred as the assisting dopant.

[0426] Polycyclic aromatic compounds represented by formula (I) exhibit a narrow emission spectrum with a low ΔE. S1T1 Due to its high TADF properties, deep HOMO, and large steric hindrance, it can be preferably used as an emitting dopant for TAF or PSF elements. Specifically, the polycyclic aromatic compound represented by formula (I) has two Y and X 2 and X4 By adopting a structure in which the atoms are bonded to the c-ring in an m-position relative to each other, it produces an emission spectrum with a narrow half-width and a small ΔE. S1T1 Furthermore, it has high TADF properties, possesses a deep HOMO due to the presence of a cyano group in the molecule, and suppresses interactions with neighboring molecules due to steric hindrance by the group represented by formula (Ar). Therefore, it can suppress Dexter energy transfer from the assisting dopant in TAF elements and from the phosphorescent material in PSF elements, making it a suitable choice for use as an emitting dopant in TAF or PSF elements.

[0427] 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 compounds represented by any of formulas (H1), (H2), and (H3), particularly mCP and mCBP, as well as compounds HH-1-115 and EH-1-99. Furthermore, TADF-active compounds may be used as the host compound. In this embodiment, it is also preferable to use a combination of a hole-transporting host material and an electron-transporting host material as the host.

[0428] The lowest excited triplet energy level E(1,T,Sh), determined from the short-wavelength shoulder of the phosphorescence spectrum of the host compound, is preferably higher than the lowest excited triplet energy levels E(2,T,Sh) and E(3,T,Sh) of the emitter or assisting dopant having the highest lowest excited triplet energy level in the light-emitting layer, from the viewpoint of promoting rather than inhibiting the generation of TADF in the light-emitting layer. Specifically, the lowest excited triplet energy level E(1,T,Sh) of the host compound is preferably 0.01 eV or higher, more preferably 0.03 eV or higher, and even more preferably 0.1 eV or higher than E(2,T,Sh) and E(3,T,Sh).

[0429] [Thermally activated delayed phosphors] A "thermally activated delayed fluorescence" refers to a compound that absorbs thermal energy to undergo reverse intersystem crossing from the lowest excited triplet state to the lowest excited singlet state, and then radiatively deactivates from that lowest excited singlet state to emit delayed fluorescence. However, "thermally activated delayed fluorescence" also includes compounds that undergo a higher-order triplet state during the excitation process from the lowest excited triplet state to the lowest excited singlet state. For example, see the paper by Monkman et al. from the University of Durham (NATURE COMMUNICATIONS, 7:13680, DOI: 10.1038 / ncomms13680), the paper by Hosokai et al. from the National Institute of Advanced Industrial Science and Technology (Hosokai et al., Sci. Adv. 2017;3: e1603282), the paper by Sato et al. from Kyoto University (Scientific Reports, 7:4820, DOI:10.1038 / s41598-017-05007-7), and also from Kyoto University. Examples include a presentation by Sato et al. at an academic conference (98th Annual Meeting of the Chemical Society of Japan, presentation number: 2I4-15, "Mechanism of high-efficiency luminescence in organic electroluminescence using DABNA as a luminescent molecule," Graduate School of Engineering, Kyoto University), a review by Bui et al. (DOI: 10.3762 / bjoc.14.18), a review by Duan et al. (DOI: 10.1063 / 1.5143501), a review by Ding et al. (DOI: 10.1088 / 1674-4926 / 42 / 5 / 050201), and a review by Xie et al. (DOI: 10.1002 / adom.202002204). In this invention, when the fluorescence lifetime of a sample containing the target compound is measured at 300K, the observation of a slow fluorescence component is used to determine that the target compound is a "thermally activated delayed phosphor." Here, a slow-fluorescent component refers to one with a fluorescence lifetime of 0.1 μsec or longer. Fluorescence lifetime can be measured, for example, using a fluorescence lifetime analyzer (Hamamatsu Photonics, C11367-01).

[0430] In a light-emitting layer further containing a "thermally activated delayed phosphor" as an assisting dopant, the polycyclic aromatic compound of the present invention can function as an emitting dopant. That is, the "thermally activated delayed phosphor" can function as an assisting dopant that assists the luminescence of the polycyclic aromatic compound of the present invention. In this specification, an organic electroluminescent device that uses a thermally activated delayed phosphor as an assisting dopant may be referred to as a "TAF device" (TADF Assisting Fluorescence device). In TAF devices, a "host compound" refers to a compound whose lowest excitation singlet energy level, determined from the short-wavelength shoulder of the fluorescence spectrum peak, is higher than that of the thermally activated delayed phosphor acting as the assisting dopant, and also higher than that of the emitting dopant.

[0431] 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.

[0432] Herein, in this specification, "electron-donating substituent" (donor) means substituents and substructures in which the HOMO is localized in a thermally activated delayed phosphor molecule, and "electron-accepting substituent" (acceptor) means substituents and substructures in which the LUMO is localized in a thermally activated delayed phosphor molecule.

[0433] 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. By using the polycyclic aromatic compound of the present invention as an emitting dopant and a thermally activated delayed phosphor (TADF material) as an assisting dopant, it is possible to provide a device that satisfies any or all of the following: high efficiency, high color purity, and long lifetime. The thermally activated delayed phosphor is a compound whose emission spectrum overlaps at least partially with the absorption spectrum of the polycyclic aromatic compound of the present invention. The polycyclic aromatic compound and the thermally activated delayed phosphor of the present invention may both be contained in the same layer, or they may be contained in adjacent layers or other nearby layers.

[0434] 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-dihydro-indenoacridine, 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.

[0435] The compound used as the assisting dopant in the light-emitting layer of a TAF device is preferably a thermally activated delayed phosphor whose emission spectrum overlaps at least partially with the absorption peak of the emitting dopant. Examples of compounds that can be used as thermally activated delayed phosphors in the light-emitting layer of a TAF device are given below. However, the compounds that can be used as thermally activated delayed phosphors in a TAF device are not limited to the following example compounds.

[0436] [ka]

[0437]

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[0438]

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[0439]

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[0440]

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[0441]

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[0449] [ka]

[0450] [ka]

[0451] [ka]

[0452] [ka]

[0453] [ka]

[0454] [ka]

[0455] [ka]

[0456] Furthermore, as a thermally activated delayed phosphor, a compound represented by any of the following formulas (AD1), (AD2), and (AD3) can also be used. [ka]

[0457] In the above formulas (AD1), (AD2), and (AD3), M is independently a single bond, -O-, >N-Ar, or >CAr2, and is preferably a single bond, -O-, or >N-Ar from the viewpoint of the depth of the HOMO of the formed substructure and the height of the excited singlet energy level and excited triplet energy level. J is a spacer structure that separates the donor substructure and the acceptor substructure, and is independently an arylene having 6 to 18 carbon atoms, and is preferably an arylene having 6 to 12 carbon atoms from the viewpoint of the magnitude of conjugation that leaches from the donor substructure and the acceptor substructure. More specifically, phenylene, methylphenylene, and dimethylphenylene are examples. Q is independently =C(-H)- or =N-, and is preferably =N- from the viewpoint of the shallowness of the LUMO of the formed substructure and the height of the excited singlet energy level and excited triplet energy level. Ar is independently hydrogen, a C6-C24 aryl, a C2-C24 heteroaryl, a C1-C12 alkyl, or a C3-C18 cycloalkyl, preferably hydrogen, a C6-C12 aryl, a C2-C14 heteroaryl, a C1-C4 alkyl, or a C6-C10 cycloalkyl, more preferably hydrogen, phenyl, tolyl, xylyl, mesityl, biphenyl, pyridyl, bipyridyl, triazyl, carbazolyl, dimethylcarbazolyl, ditert-butylcarbazolyl, benzimidazolyl, or phenylbenzimidazolyl, and even more preferably hydrogen, phenyl, or carbazolyl. m is 1 or 2. n is an integer from 1 to (6-m), preferably an integer from 4 to (6-m) from the viewpoint of steric hindrance. Furthermore, at least one hydrogen atom in each of the above formulas may be substituted with a halogen or deuterium.

[0458] More specifically, the compounds used as the second component in this embodiment are preferably 4CzBN, 4CzBN-Ph, 5CzBN, 3Cz2DPhCzBN, 4CzIPN, 2PXZ-TAZ, Cz-TRZ3, BDPCC-TPTA, MA-TA, PA-TA, FA-TA, PXZ-TRZ, DMAC-TRZ, BCzT, DCzTrz, DDCzTRz, spiroAC-TRZ, Ac-HPM, Ac-PPM, Ac-MPM, TCzTrz, TmCzTrz, and DCzmCzTrz.

[0459] The compound used as the second component in this embodiment may be a donor-acceptor type TADF compound represented by DA, in which one donor D and one acceptor A are directly bonded or bonded via a linking group. However, it is preferable that the compound has a structure represented by the following formula (DAD1), in which multiple donor Ds are directly bonded or bonded via linking groups to one acceptor A, as this results in better characteristics of the organic electroluminescent element. (D 1 -L 1 )nA 1 (DAD1) Formula (DAD1) includes compounds represented by the following formula (DAD2). D 2 -L 2 -A 2 -L 3 -D 3 (DAD2) In equations (DAD1) and (DAD2), D 1 , D 2 and D 3 Each of these independently represents a donor group. The donor structure described above can be used as the donor group. A 1 and A 2 Each of these independently represents an acceptor group. The above acceptor structure can be used as the acceptor group. 1 , L 2 and L 3Each of these independently represents a single bond or a conjugated linkage group. The conjugated linkage group is a spacer structure that separates the donor group and the acceptor group, and is preferably an arylene having 6 to 18 carbon atoms, and more preferably an arylene having 6 to 12 carbon atoms. 1 , L 2 and L 3 It is even more preferable that each of them is independently phenylene, methylphenylene, or dimethylphenylene. In formula (DAD1), n ​​is 2 or more, and A 1 n represents an integer less than or equal to the maximum number of substitutions possible. n can be selected, for example, from 2 to 10 or from 2 to 6. When n is 2, the compound is represented by formula (DAD2). n D 1 They may be the same or different, and n L 1 These may be the same or different. Preferred specific examples of the compounds represented by formulas (DAD1) and (DAD2) include 2PXZ-TAZ and the following compounds, but the second component that can be used in the present invention is not limited to these compounds.

[0460] [ka]

[0461] [Phosphorescent materials (assisting dopant)] In the light-emitting layer, a phosphorescent material may be used as an assisting dopant. In this specification, an organic electroluminescent element that uses a phosphorescent material as an assisting dopant is sometimes referred to as a phosphorescent assist element, a phosphor-sensitized fluorescent (PSF) element, or a phosphorescent material. The phosphorescent material utilizes intramolecular spin-orbit interaction (heavy atom effect) by metal atoms to obtain light emission from an excited 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).

[0462] [ka]

[0463] 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.

[0464] [ka]

[0465] 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.

[0466] 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.

[0467] Other compounds represented by formula (B-1) include, for example, the following compounds.

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[0468]

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[0469]

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[0470]

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[0471] Furthermore, 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, EnergyChem, 6, 2, 100120 (2024), etc., or 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, Journal of Material Platinum complexes described in Chemisty C, 2022, 10, 210-218, Advanced Materials, 35, 2303066 (2023), Communications Chemistry 8, 140 (2025), Advanced Optical Materials 11, 220269 (2023), Nature Communications 15, 2977 (2024), Chemical Engineering Journal, 505, 159169 (2025), and ACS Applied Materials & Interfaces, 14, 30, 34901-34908 (2022) may be used. Alternatively, complexes described in Chemistry Society Review, 54, 266-340 (2025) may be used.

[0472] <Other dopant materials> The polycyclic aromatic compound represented by formula (I) may be used in combination with other dopant materials. However, the amount of other dopant materials in a single luminescent layer is preferably less than 100% by mass, more preferably 50% by mass or less, even more preferably 30% by mass or less, and particularly preferably 10% by mass or less, relative to the total mass of the polycyclic aromatic compound represented by formula (I). Known compounds can be used as the other dopant materials, and a variety of materials can be selected depending on the desired luminescence 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.

[0473] As other dopant materials, it is also preferable to use polycyclic aromatic compounds 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.

[0474] 2-1-6. Electron injection layer and electron transport layer in organic electroluminescent devices The electron injection layer 107 plays the role of efficiently injecting electrons moving from the cathode 108 into the light-emitting layer 105 or the electron transport layer 106. The electron transport layer 106 plays the role of efficiently transporting electrons injected from the cathode 108 or electrons injected from the cathode 108 via the electron injection layer 107 to the light-emitting layer 105. The electron transport layer 106 and the electron injection layer 107 are each formed by laminating and mixing one or more types of electron transport / injection materials, or by a mixture of electron transport / injection materials and a polymer binder.

[0475] 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.

[0476] 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.

[0477] 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.

[0478] 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.

[0479] 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.

[0480] The materials mentioned above can be used individually, but they can also be used in combination with other materials.

[0481] 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.

[0482] 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.

[0483] 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.

[0484] 2-1-7. Cathode in an Organic Electroluminescent Device The cathode 108 plays the role of injecting electrons into the light-emitting layer 105 via the electron injection layer 107 and the electron transport layer 106.

[0485] 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.

[0486] 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.

[0487] 2-1-8. Method for fabricating organic electroluminescent devices Each layer constituting an organic EL element can be formed by thinning the material to be composed of each layer using methods such as vapor deposition, resistance heating deposition, electron beam deposition, sputtering, molecular stacking, printing, spin coating or casting, or coating. There are no particular limitations on the thickness of each layer formed in this way, and it can be set appropriately according to the properties of the material, but it is usually in the range of 2 nm to 5000 nm. The thickness can usually be measured with a quartz crystal oscillating film thickness measuring device. When thinning using vapor deposition, the deposition conditions vary depending on the type of material, the desired crystal structure and association structure of the film, etc. Generally, the deposition conditions are a boat heating temperature of +50 to +400°C and a vacuum of 10°C. -6 ~10 -3 It is preferable to appropriately set the Pa, deposition rate to 0.01 to 50 nm / second, substrate temperature to -150 to +300°C, and film thickness to 2 nm to 5 μm.

[0488] 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.

[0489] 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.

[0490] <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.

[0491] <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.

[0492] 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.

[0493] 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.

[0494] 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.

[0495] 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.

[0496] 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.

[0497] <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.

[0498] <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.

[0499] 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.

[0500] <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.

[0501] <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.

[0502] 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.

[0503] (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.

[0504] <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.

[0505] <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.

[0506] The organic layer-forming composition can be produced by appropriately selecting stirring, mixing, heating, cooling, dissolving, and dispersing the above-mentioned components using known methods. Furthermore, after preparation, appropriate treatments such as filtration, degassing, ion exchange treatment, and inert gas replacement / sealing treatment may be performed.

[0507] 2-1-9. Application Examples of Organic Electroluminescent Devices This invention can also be applied to display devices equipped with organic EL elements or lighting devices equipped with organic EL elements. A display device or lighting device equipped with an organic EL element can be manufactured by known methods, such as connecting the organic EL element according to this embodiment with a known driving device, and can be driven using known driving methods such as DC driving, pulse driving, or AC driving as appropriate.

[0508] 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.

[0509] 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.

[0510] 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.

[0511] 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.

[0512] 2-2. Other Organic Devices The polycyclic aromatic compounds according to the present invention can be used not only for the organic field-light-emitting device described above, but also for the fabrication of organic field-effect transistors, organic thin-film solar cells, or organic photodiodes (organic photodetectors).

[0513] An organic field-effect transistor (OCT) is a type of transistor that controls current using an electric field generated by a voltage input. In addition to source and drain electrodes, it has a gate electrode. When a voltage is applied to the gate electrode, an electric field is generated, allowing the current to be controlled by arbitrarily blocking the flow of electrons (or holes) between the source and drain electrodes. Compared to simple transistors (bipolar transistors), OTCs are easier to miniaturize and are frequently used as components in integrated circuits.

[0514] The structure of an organic field-effect transistor typically includes a source electrode and a drain electrode in contact with an organic semiconductor active layer formed using the polycyclic aromatic compound according to the present invention, and a gate electrode further separated by an insulating layer (dielectric layer) in contact with the organic semiconductor active layer. Examples of such device structures include the following: (1) Substrate / Gate electrode / Insulator layer / Source electrode / Drain electrode / Organic semiconductor active layer (2) Substrate / Gate electrode / Insulator layer / Organic semiconductor active layer / Source electrode / Drain electrode (3) Substrate / Organic semiconductor active layer / Source electrode / Drain electrode / Insulator layer / Gate electrode (4) Substrate / Source electrode / Drain electrode / Organic semiconductor active layer / Insulator layer / Gate electrode Organic field-effect transistors configured in this way can be applied as pixel driving switching elements in active-matrix driven liquid crystal displays and organic electroluminescent displays.

[0515] Organic thin-film solar cells have a structure in which an anode such as ITO, a hole transport layer, a photoelectric conversion layer, an electron transport layer, and a cathode are stacked on a transparent substrate such as glass. The photoelectric conversion layer has a p-type semiconductor layer on the anode side and an n-type semiconductor layer on the cathode side. The polycyclic aromatic compound according to the present invention can be used as a material for the hole transport layer, p-type semiconductor layer, n-type semiconductor layer, and electron transport layer, depending on its physical properties. The polycyclic aromatic compound according to the present invention can function as a hole transport material or an electron transport material in organic thin-film solar cells. In addition to the above, organic thin-film solar cells may appropriately include a hole blocking layer, an electron blocking layer, an electron injection layer, a hole injection layer, a smoothing layer, etc. Organic thin-film solar cells can be appropriately selected and combined with known materials used in organic thin-film solar cells.

[0516] An organic photodiode is a mechanism that uses organic materials to convert light into electrical signals, and is used, for example, as an organic photodetector or organic photodetector. An organic photodiode has a sandwich structure in which an organic layer containing a light absorber is sandwiched between electrodes as an active layer.

[0517] The polycyclic aromatic compounds of the present invention can be used to form the active layer of an organic photodiode. Generally, the active layer contains a donor compound (electron-donating compound) and an acceptor compound (electron-accepting compound). After light is absorbed by the active layer, an excited state moves to the interface of the donor-acceptor compound, inducing charge separation. Subsequently, the generated holes and electrons are collected at their respective electrodes, generating an electric current. On the other hand, the polycyclic aromatic compounds of the present invention that exhibit multiple resonance effects can form an active layer as a single component as a light absorber (Adv. Mater. 2024, 2414465). That is, the active layer can be formed solely from the polycyclic aromatic compounds of the present invention.

[0518] Furthermore, the polycyclic aromatic compounds of the present invention can also be used as donor compounds or acceptor compounds in the active layer by selecting substituents. In this case, the acceptor or donor compound to be combined may be a polymer material, an ionic compound, a metal complex, or an inorganic material, and in the case of a polymer material, a crosslinking agent may be added.

[0519] Examples of donor compounds to be combined with the polycyclic aromatic compound of the present invention include tetrathianaphthalene, and examples of polymer materials include F8BT (poly(9,9-di-n-octylfluorenyl-2,7-diyl)-co-1,4-benzo-(2,1,3)-thiadiazole) and PFO (poly(9,9-din-octylfluorene)). Inorganic materials can include alkali metals, alkaline earth metals, rare earth metals, or metals belonging to Group 13 of the periodic table, as well as their oxides and carbonates, such as lithium, cesium, magnesium, calcium, indium, ytterbium, lithium oxide, and cesium carbonate.

[0520] Examples of acceptor compounds to be combined with the polycyclic aromatic compound of the present invention include 7,7,8,8-tetracyano-2,3,5,6-tetrafluoroquinodimethane (F4-TCNQ) and tetrachloro-1,4-benzoquinone (chloranil). In addition, inorganic materials such as molybdenum oxide, tin oxide, vanadium oxide, niobium oxide, tantalum oxide, chromium oxide, tungsten oxide, manganese oxide, and rhenium oxide can be used.

[0521] When the active layer contains both donor and acceptor compounds, methods such as dissolving and mixing them together (bulk heterojunction) or joining them in a planar manner (parallel heterojunction) are used, and the method is selected considering the properties of the compounds used. It is also possible to mix materials that act as quantum dots to form a nanocomposite active layer (Adv. Mater. 2016, 28, 2043-2048).

[0522] An organic photodiode may have a hole-blocking layer and an electron-blocking layer in addition to a pair of electrodes and an active layer placed between the pair of electrodes. Typically, a hole-blocking layer and an electron-blocking layer are provided above and below the active layer in contact with it, and an anode electrode and a cathode electrode may be provided further. Examples of such structures include the following. Depending on the characteristics of the active layer, the hole-blocking layer or electron-blocking layer may be omitted, and a layer that functions as an electron transport layer or hole transport layer may be added. (1) Substrate / Anode electrode / Electron blocking layer / Active layer / Hole blocking layer / Cathode electrode (2) Substrate / Cathode electrode / Hole blocking layer / Active layer / Electron blocking layer / Anode electrode

[0523] Inorganic materials or polymeric materials may be used for the electron blocking layer and hole blocking layer. Examples of polymeric materials include PEDOT / PSS (Poly3,4-EthyleneDiOxyThiophene / Poly4-StyreneSulfonate).

[0524] For organic photodiodes, in addition to the above, you can also refer to Adv. Mater. 2016, 28, 4766, Adv. Opt. Mater. 2024, 12, 2303216, Adv. Mater. 2016, 28, 2043, Nat.Commun. 2020, 11, 2871, Nano Lett. 2017, 17, 1995, Adv. Mater. 2017, 29, 1702184, Chem. Mater. 2021, 33, 5147, etc.

[0525] 3. Wavelength conversion materials The polycyclic aromatic compounds of the present invention can be used as wavelength conversion materials. Currently, there is much research into applying multi-color technology using color conversion methods to liquid crystal displays, organic EL displays, and lighting. Color conversion refers to the conversion of light emitted from a light source to longer wavelength light, for example, converting ultraviolet light or blue light into green light or red light. By creating a film of a wavelength conversion material with this color conversion function and combining it with, for example, a blue light source, it becomes possible to extract the three primary colors of blue, green, and red from the blue light source, i.e., to extract white light. By using such a white light source, which combines a blue light source with a wavelength conversion film with color conversion function, as a light source unit and combining it with a liquid crystal drive unit and a color filter, it becomes possible to manufacture a full-color display. Furthermore, if the liquid crystal drive unit is not required, it can be used as a white light source as is, and can be applied as a white light source for LED lighting, for example. In addition, by using a blue organic EL element as a light source and combining it with a wavelength conversion film that converts blue light into green and red light, it becomes possible to manufacture a full-color organic EL display without using a metal mask. Furthermore, by using a blue microLED as a light source in combination with a wavelength conversion film that converts blue light into green and red light, it becomes possible to create low-cost full-color microLED displays.

[0526] The polycyclic aromatic compounds of the present invention can be used as wavelength conversion materials. Using a wavelength conversion material containing the polycyclic aromatic compounds of the present invention, light from light sources or light-emitting elements that generate ultraviolet or blue light can be converted into green light with a color purity suitable for use in display devices (display devices using organic EL elements or liquid crystal displays). The color to be converted can be adjusted by appropriately selecting substituents on the polycyclic aromatic compounds of the present invention, binder resins used in the wavelength conversion composition described later, etc. The wavelength conversion material can be prepared as a wavelength conversion composition containing the polycyclic aromatic compounds of the present invention. Alternatively, a wavelength conversion film may be formed using this wavelength conversion composition.

[0527] The wavelength conversion composition may contain, in addition to the polycyclic aromatic compound of the present invention, a binder resin, other additives, and a solvent. As the binder resin, for example, those described in paragraphs 0173 to 0176 of International Publication No. 2016 / 190283 can be used. As the other additive, compounds described in paragraphs 0177 to 0181 of International Publication No. 2016 / 190283 can be used. As the solvent, refer to the description of solvents included in the above-mentioned light-emitting layer forming composition.

[0528] The wavelength conversion film includes a wavelength conversion layer formed by curing a wavelength conversion composition. Known film formation methods can be used as a method for producing the wavelength conversion layer from the wavelength conversion composition. The wavelength conversion film may consist solely of a wavelength conversion layer formed from a composition containing the polycyclic aromatic compound of the present invention, or it may include other wavelength conversion layers (for example, a wavelength conversion layer that converts blue light to green or red light, or a wavelength conversion layer that converts blue or green light to red light). Furthermore, the wavelength conversion film may include a substrate layer and a barrier layer to prevent degradation of the color conversion layer due to oxygen, moisture, or heat. [Examples]

[0529] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0530] <<Example of synthesis>> Synthesis Example (1): Synthesis of Compounds (1-3) [ka]

[0531] <First step> Under a nitrogen atmosphere, 2.54 g, 3 mmol of compound (S-3) was dissolved in 10 mL of o-dichlorobenzene, to which 1.07 g, 6 mmol of N-bromosuccinimide was added at -10°C. The mixture was stirred at -10°C for 2 hours, then poured into 30 mL of water and extracted with 3 × 20 mL of dichloromethane. The combined organic layer was washed with saturated brine and dried over anhydrous sodium sulfate. After removing the solvent under reduced pressure, the crude product was purified by silica gel column chromatography (eluent: toluene, dichloromethane) to obtain the target compound (S-4) (1.48 g, 1.47 mmol).

[0532] [ka]

[0533] Compound (S-3) was synthesized according to the synthesis example described in International Publication No. 2018 / 212169.

[0534] <Second process> Dichlorobis[di-tert-butyl(p-dimethylaminophenyl)phosphino]palladium(II) (85 mg, 0.12 mmol), compound (S-4) (1.205 g, 1.2 mmol), potassium hexacyanoferrate(II) (2.14 g, 4.8 mmol), and sodium carbonate (0.20 g, 1.92 mmol) were dissolved in N,N-dimethylacetamide (5.0 mL) under a nitrogen atmosphere. After stirring at 140 °C for 24 hours, the reaction mixture was diluted with toluene (30 mL), and the reaction was stopped by adding water (30 mL) at 0 °C. The aqueous layer was separated and extracted with dichloromethane (30 mL, 3 times). The combined organic layers were washed with saturated brine and dried over anhydrous sodium sulfate. After removing the solvent under reduced pressure, the crude product was purified by silica gel column chromatography (eluent: toluene, dichloromethane). The product was washed with octane to obtain compound (1-3) (401 mg, 0.36 mmol).

[0535] [ka]

[0536] Synthesis Example (2): Synthesis of Compounds (1-9) [ka]

[0537] <First step> Boron triiodide (4.05 g, 4.0 mmol) and compound (S-5) (6.26 g, 16.0 mmol) were dissolved in 1,2-dichlorobenzene (5.0 mL) under a nitrogen atmosphere. After stirring at 70°C for 24 hours, the reaction mixture was diluted with dichloromethane (20 mL), and the reaction was stopped at 0°C with phosphate buffer (pH 7, 20 mL). The aqueous layer was separated and extracted with dichloromethane (20 mL, 3 times). After removing the solvent under vacuum, the crude product was separated into highly polar and low-polar components by silica gel column chromatography (eluent: hexane / dichloromethane = 1 / 1, ethyl acetate). Acetic acid (1.0 mL, 35.0 mmol) was added to the highly polar component in toluene (10.0 mL) at room temperature. After stirring at 60°C for 1 hour, saturated sodium carbonate aqueous solution (10 mL) was added to the reaction mixture, and the aqueous layer was extracted with toluene (30 mL, 3 times). The combined organic layers were concentrated under vacuum. The crude product was purified by silica gel column chromatography (eluent: hexane / dichloromethane = 3 / 1, 2 / 1). The product was washed with octane and acetonitrile to obtain compound (S-6) (620 mg, 0.6 mmol).

[0538] [ka]

[0539] <Second process> Using dichlorobis[di-tert-butyl(p-dimethylaminophenyl)phosphino]palladium(II) (39 mg, 0.055 mmol), compound (S-6) (0.55 g, 0.557 mmol), potassium hexacyanoferrate(II) (0.98 g, 2.2 mmol), sodium carbonate (0.88 g, 0.093 mmol), and N,N-dimethylacetamide (5.0 mL), the target compounds (1-9) were obtained by performing the same procedure as in the second step of synthesis example (2).

[0540] [ka]

[0541] Synthesis Example (3): Synthesis of Compounds (1-13) [ka]

[0542] <First step> Under a nitrogen atmosphere, a solution of compound (S-7) (175 mg, 0.2 mmol) in THF (20 mL) was cooled at -60°C for 30 minutes, after which a solution of dibromoisocyanuric acid (DBI, 75 mg, 0.26 mmol) in THF (3 mL) was added. The mixture was then stirred at -60°C for 10 minutes, followed by stirring at -20°C for 1 hour. The reaction mixture was purified using a short column (packing material: alumina, eluent: THF), and after removing the solvent under reduced pressure, the crude product was purified by silica gel column chromatography (eluent: hexane / toluene = 5 / 1) to obtain the target compound (S-8) (167 mg, 0.162 mmol).

[0543] [ka]

[0544] Compound (S-7) was synthesized according to the synthesis example described in International Publication No. 2018 / 212169.

[0545] 1 HNMR(CD2Cl2,495MHz);10.30(s,1H),8.84(s,2H),7.51(d,J=8.8Hz,3H),7.41-7.36(m,6H),7.34(dd,J=8.8,2.0Hz,2H ),7.21-7.19(m,4H),7.17(s,4H),6.69(d,J=8.8Hz,2H),6.14(d,J=9.1Hz,2H),2.44(s,6H),2.43(s,6H),1.84(s,12H).

[0546] <Second process> The compound (S-8) (125 mg, 0.12 mmol) and copper(I) cyanide (90 mg, 1.0 mmol) obtained in the first step were placed in a 25 mL Schlenk tube, purged with nitrogen, and then N,N-dimethylformamide (6.0 mL) was added under a nitrogen stream. After stirring at 150 °C for 24 hours, the reaction mixture was allowed to cool to room temperature. Water, iron(III) chloride, and concentrated hydrochloric acid were added, and the mixture was stirred for 5 minutes to stop the reaction. The aqueous layer was separated and extracted with dichloromethane (30 mL, 3 times). The combined organic layers were washed with saturated brine and dried over anhydrous sodium sulfate. After removing the solvent under reduced pressure, the crude product was purified by flash chromatography (eluate: hexane / ethyl acetate = 4 / 1) to obtain compound (1-13) (48 mg, 0.052 mmol).

[0547] 1 HNMR(CDCl3,495MHz);10.67(s,1H),9.01(s,2H),7.61(t,J=7.7Hz,2H),7.54(d,J=9.1Hz,2H),7.45(t,J=7.9Hz,4H),7.38(dd,J=8.8,1.7Hz,2 H),7.27(dd,J=8.4,1.0Hz,4H),7.18(s,4H),6.76(d,J=8.8Hz,2H),6.2 1(d,J=8.8Hz,2H),6.18(s,1H),2.54(s,6H),2.47(s,6H),1.87(s,12H).

[0548] [ka]

[0549] Synthesis Example (4): Synthesis of Compounds (1-14) [ka]

[0550] <First step> Boron triiodide (2.11 g, 5.4 mmol) and compound (S-9) (1.30 g, 1.35 mmol) were dissolved in 1,2-dichlorobenzene (8.0 mL) under a nitrogen atmosphere. After stirring at 100 °C for 10 hours, the reaction mixture was allowed to cool to room temperature, and the reaction was stopped by adding phosphate buffer. The aqueous layer was separated and extracted with toluene. After removing the solvent under reduced pressure, the crude product was purified by silica gel column chromatography (eluate: hexane / dichloromethane = 5 / 1) to obtain compound (S-10) (420 mg, 0.43 mmol).

[0551] [ka]

[0552] <Second process> [1,2-Bis(diphenylphosphino)ethane]dichloronickel(II) (45 mg, 0.082 mmol), compound (S-10) (0.40 g, 0.41 mmol), and sodium borohydride (95 mg, 2.5 mmol) were placed in a flask, then purged with nitrogen, and N,N-dimethylacetamide (15 mL) was added. After stirring at 110°C for 17 hours, the reaction mixture was allowed to cool to room temperature, and the reaction was stopped by adding aqueous ammonium chloride. The aqueous layer was separated and extracted with toluene. After removing the solvent under reduced pressure, the crude product was purified by silica gel column chromatography (eluate: hexane / dichloromethane = 5 / 1) to obtain compound (S-11) (300 mg, 0.328 mmol).

[0553] [ka] <Third step> Under a nitrogen atmosphere, a 15 mL solution of compound (S-11) (226 mg, 0.25 mmol) in THF was cooled to -60°C, and a 3 mL solution of N-bromosuccinimide (90 mg, 0.5 mmol) in THF was added dropwise. The mixture was then stirred at -60°C for 10 minutes, followed by stirring at -20°C for 11 hours. The reaction mixture was purified using a short column (packing material: alumina, eluent: THF), and the solvent was removed under reduced pressure. The crude product was then purified by silica gel column chromatography (eluent: hexane / toluene = 5 / 1) to obtain compound (S-12) (180 mg, 0.17 mmol).

[0554] 1 HNMR(495MHz,CD2Cl2)δ10.47(s,1H),8.73(s,2H),7.54(d,J=8.8Hz,2H),7.46(d,J=8.8Hz,2H),7.35(d,J=8.2H) z,6H),7.28(d,J=9.4Hz,4H),6.92(s,4H),6.11(d,J=8.8Hz2H),5.80(s,1H),2.44-2.41(m,18H),1.74(s,12H).

[0555] [ka]

[0556] <Fourth process> Using the compound (S-12) (138 mg, 0.13 mmol) obtained in the third step, copper(I) cyanide (70 mg, 0.78 mmol), and N,N-dimethylformamide (5.0 mL), compound (1-14) (85 mg, 0.088 mmol) was obtained by performing the same procedure as in the second step of synthesis example (3).

[0557] [ka]

[0558] 1HNMR(CDCl3,495MHz);δ10.72(s,1H),8.97(s,2H),7.59(d,J=8.8Hz,2H),7.50(d,J=7.9Hz,4H),7.41(d,J=8.2Hz,4H),7.36(dd,J=8.9, 1.8Hz,2H),6.94(s,4H),6.87(d,J=8.8Hz,2H),6.17(d,J=9.1Hz,2H),5.94(s,1H),2.60(s,6H),2.51(s,6H),2.44(s,6H),1.73(s,12H).

[0559] Synthesis Example (5): Synthesis of Compounds (1-15) [ka]

[0560] <First step> Using boron triiodide (1.56 g, 4.0 mmol), compound (S-13) (985 mg, 1.0 mmol), and 1,2-dichlorobenzene (10.0 mL), compound (S-14) (300 mg, 0.3 mmol) was obtained by performing the same procedure as in the first step of synthesis example (5).

[0561] [ka]

[0562] <Second process> Compound (S-15) (225 mg, 0.24 mmol) was obtained by using [1,2-bis(diphenylphosphino)ethane]dichloronickel(II) (32 mg, 0.082 mmol), compound (S-14) (0.30 g, 0.3 mmol), sodium borohydride (70 mg, 1.8 mmol), and N,N-dimethylacetamide (10 mL) and performing the same procedure as in the second step of synthesis example (5).

[0563] [ka]

[0564] <Third step> Under a nitrogen atmosphere, compound (S-16) (152 mg, 0.14 mmol) was obtained by performing the same procedure as in the third step of synthesis example (4) using a solution of compound (S-15) (185 mg, 0.2 mmol) in THF (10 mL) and a solution of N-bromosuccinimide (72 mg, 0.4 mmol) in THF (2 mL).

[0565] [ka]

[0566] <Fourth process> Compound (1-15) (82 mg, 0.084 mmol) was obtained by using the compound (S-16) (152 mg, 0.14 mmol) obtained in the third step, copper(I) cyanide (75 mg, 0.84 mmol), and N,N-dimethylformamide (5.0 mL) and performing the same procedure as in the second step of synthesis example (3).

[0567] [ka]

[0568] Synthesis Example (6): Synthesis of Compounds (1-16) [ka]

[0569] <First step> Under a nitrogen atmosphere, compound (S-18) (140 mg, 0.11 mmol) was obtained by performing the same procedure as in the third step of synthesis example (4) using a solution of compound (S-17) (336 mg, 0.3 mmol) in THF (15 mL) and a solution of N-bromosuccinimide (107 mg, 0.6 mmol) in THF (3 mL).

[0570] [ka]

[0571] <Second process> Using the compound (S-18) (128 mg, 0.1 mmol) obtained in the first step, copper(I) cyanide (54 mg, 0.6 mmol), and N,N-dimethylformamide (4.0 mL), compound (1-16) (67 mg, 0.057 mmol) was obtained by performing the same procedure as in the second step of synthesis example (3).

[0572] [ka]

[0573] Synthesis Example (7): Synthesis of Compounds (1-17) [ka]

[0574] <First step> Under a nitrogen atmosphere, compound (S-20) (124 mg, 0.095 mmol) was obtained by performing the same procedure as in the third step of synthesis example (4) using a solution of compound (S-19) (345 mg, 0.3 mmol) in THF (15 mL) and a solution of N-bromosuccinimide (107 mg, 0.6 mmol) in THF (3 mL).

[0575] [ka]

[0576] <Second process> Using the compound (S-20) (105 mg, 0.08 mmol) obtained in the first step, copper(I) cyanide (37 mg, 0.48 mmol), and N,N-dimethylformamide (3.0 mL), compound (1-17) (60 mg, 0.05 mmol) was obtained by performing the same procedure as in the second step of synthesis example (3).

[0577] [ka]

[0578] Synthesis Example (8): Synthesis of Compounds (1-18) [ka]

[0579] <First step> Under a nitrogen atmosphere, compound (S-22) (81 mg, 0.072 mmol) was obtained by performing the same procedure as in the third step of synthesis example (4) using a solution of compound (S-21) (336 mg, 0.3 mmol) in THF (15 mL) and a solution of N-bromosuccinimide (107 mg, 0.6 mmol) in THF (3 mL).

[0580] [ka]

[0581] <Second process> Using the compound (S-22) (73 mg, 0.065 mmol) obtained in the first step, copper(I) cyanide (35 mg, 0.39 mmol), and N,N-dimethylformamide (3.0 mL), compound (1-18) (42 mg, 0.041 mmol) was obtained by performing the same procedure as in the second step of synthesis example (3).

[0582] [ka]

[0583] Synthesis Example (9): Synthesis of Compounds (1-19) [ka]

[0584] <First step> Under a nitrogen atmosphere, compound (S-24) (78 mg, 0.068 mmol) was obtained by performing the same procedure as in the third step of synthesis example (4) using a solution of compound (S-23) (345 mg, 0.3 mmol) in THF (15 mL) and a solution of N-bromosuccinimide (107 mg, 0.6 mmol) in THF (3 mL).

[0585] [ka]

[0586] <Second process> Using the compound (S-24) (69 mg, 0.06 mmol) obtained in the first step, copper(I) cyanide (32 mg, 0.36 mmol), and N,N-dimethylformamide (3.0 mL), compound (1-19) (35 mg, 0.033 mmol) was obtained by performing the same procedure as in the second step of synthesis example (3).

[0587] [ka]

[0588] Compounds (1-1), (1-2), (1-4) to (1-8), (1-10) to (1-12), (2-1) to (2-5), (3-1) to (3-5), (4-1) to (4-5), and (5-1) to (5-5) were synthesized using methods consistent with synthesis examples (1) to (9).

[0589] [ka]

[0590] [ka]

[0591] [ka]

[0592] [ka]

[0593] [ka]

[0594] Compounds (C1-1) to (C1-5), (C2-1) to (C2-5), (C3-1), (C4-1) to (C4-4), (C5-1), and (C5-2) are each compounds described in Japanese Patent Publication No. 2023-152686, and were synthesized by a method consistent with that publication.

[0595] [ka]

[0596] [ka]

[0597] [ka]

[0598] [ka]

[0599] [ka]

[0600] The formation of the target substance was confirmed by MALDI-TOF-MS (matrix-assisted laser desorption / ionization time-of-flight mass spectrometry).

[0601] [Table 1]

[0602] <<Method for Evaluating Basic Physical Properties>> Sample preparation The basic physical properties of the compounds (1-13) and (1-14) synthesized above were evaluated. In this example, after dissolving PMMA and the compound to be evaluated in toluene, a thin film was formed on a transparent support substrate made of quartz or glass by spin coating to prepare a sample. The concentration of the compound to be evaluated in the coating film was set to 1% by mass.

[0603] Evaluation of luminescence characteristics The coating film formed on the transparent support substrate made of glass was used as a sample for measurement. The fluorescence spectrum of the sample was measured using a spectrofluorometer (F-7000, manufactured by Hitachi High-Technologies Corporation).

[0604] The fluorescence spectrum was measured by exciting the above sample at room temperature. The excitation wavelength in the spectrum measurement was set to 340 nm. The full width at half maximum was determined as the width between the upper and lower wavelengths at which the intensity becomes 50% centered on the maximum emission wavelength.

[0605]

Table 2

[0606] <<Manufacture and Evaluation of Vapor Deposition-Type Organic EL Devices>> Using each of the synthesized compounds of the present invention and comparative compounds, each of the organic EL devices of TAF and PSF was manufactured.

[0607] <TAF Configuration: Example T1-1 to Example T1-19, Example T2-1 to Example T2-5, Example T3-1 to Example T3-5, Example T4-1 to Example T4-5, Example T5-1 to Example T5-5, Comparative Example CT1-1 to Comparative Example CT1-5, Comparative Example CT2-1 to Comparative Example CT2-5, Comparative Example CT3-1, Comparative Example CT4-1 to Comparative Example CT4-4, Comparative Example CT5-1 and Comparative Example CT5-2> ITO (50nm) / HAT-CN (10nm) / HT-1 (60nm) / SiCzCz (5nm) / SiCzCz:SiTrzCz2:TADF-1: Each compound listed in Table 3 (60:26:13:1) (35nm) / mSiTrz (5nm) / mSiTrz:Liq (1:1) (30nm) / LiF (1nm) / Al (100nm) 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, HT-1, SiCzCz, SiTrzCz2, each compound listed in Table 3, mSiTrz, and Liq, respectively, and tungsten deposition boats containing LiF and aluminum, respectively, were mounted.

[0608] The following layers were sequentially formed on the ITO film of the transparent support substrate. The vacuum chamber was 5 × 10 -4The pressure was reduced to Pa. First, HAT-CN was heated and vapor-deposited to a thickness of 10 nm to form a hole injection layer. Next, HT-1 was heated and vapor-deposited to a thickness of 60 nm to form a hole transport layer 1, and further, SiCzCz was heated and vapor-deposited to a thickness of 5 nm to form a hole transport layer 2. Next, SiCzCz, SiTrzCz2, (TADF-1), and each compound described in Table 3 were simultaneously heated and vapor-deposited to a thickness of 35 nm to form a light-emitting layer. The deposition rate was adjusted so that the mass ratio of SiCzCz, SiTrzCz2, (TADF-1), and each compound described in Table 3 was approximately 60:26:13:1. Next, mSiTrz was heated and vapor-deposited to a thickness of 5 nm to form an electron transport layer 1, and further, mSiTrz and Liq were heated and vapor-deposited to a thickness of 30 nm to form an electron transport layer 2. The deposition rate was adjusted so that the mass ratio of SiTrz and Liq was approximately 1:1. The deposition rate of each layer was 0.01 to 1 nm / second. Thereafter, LiF was heated and vapor-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 vapor-deposited to a thickness of 100 nm to form a cathode, obtaining an organic EL device. At this time, the deposition rate of aluminum was adjusted to be 1 to 10 nm / second. Note that SiCzCz in the light-emitting layer corresponds to a hole-transporting host material, and SiTrzCz2 corresponds to an electron-transporting host material.

[0609] <PSF configuration: Examples P1-1 to P1-19, Examples P2-1 to P2-5, Examples P3-1 to P3-5, Examples P4-1 to P4-5, Examples P5-1 to P5-5, Comparative Examples CP1-1 to CP1-5, Comparative Examples CP2-1 to CP2-5, Comparative Example CP3-1, Comparative Examples CP4-1 to CP4-4, Comparative Example CP5-1 and Comparative Example CP5-2> ITO(50 nm) / HAT-CN(10 nm) / HT-1(60 nm) / SiCzCz(5 nm) / SiCzCz:SiTrzCz2:PtON-TBBI: each compound described in Table 4(60:26:13:1)(35 nm) / mSiTrz(5 nm) / mSiTrz:Liq(1:1)(30 nm) / LiF(1 nm) / Al(100 nm) The above TAF configuration was modified by replacing (TADF-1) with PtON-TBBI, and the device was fabricated in the same manner.

[0610] The chemical structures of the compounds used in the manufacture of each of the above elements are shown below.

[0611] [ka]

[0612] [evaluation] The evaluation items include driving voltage (V), emission wavelength (nm), CIE chromaticity (x,y), external quantum efficiency (%), maximum wavelength (nm) and full width at half maximum (nm) of the emission spectrum. These evaluation items are, for example, 1000 cd / m². 2 The value at the time of emission can be used.

[0613] The quantum efficiency of a light-emitting device has two components: internal quantum efficiency and external quantum efficiency. Internal quantum efficiency indicates the proportion of external energy injected into the light-emitting layer of the device as electrons (or holes) that is purely converted into photons. External quantum efficiency, on the other hand, is calculated based on the amount of these photons emitted to the outside of the device. Since some of the photons generated in the light-emitting layer are absorbed or reflected within the device and not emitted to the outside, the external quantum efficiency is lower than the internal quantum efficiency.

[0614] The measurement method for spectral radiance (emission spectrum) and external quantum efficiency is as follows: Using an Advantest R6144 voltage / current generator, the device's radiance was 1000 cd / m². 2A voltage is applied to cause the element to emit light. A TOPCON SR-3AR spectroradiometer is used to measure the spectral radiance in the visible light region from a direction perpendicular to the light-emitting surface. Assuming the light-emitting surface is a perfectly diffusive surface, the number of photons at each wavelength is obtained by dividing the measured spectral radiance value of each wavelength component by the wavelength energy and multiplying by π. Next, the number of photons is integrated across the entire observed wavelength range to obtain the total number of photons emitted from the element. The number of carriers injected into the element is obtained by dividing the applied current value by the elementary charge, and the external quantum efficiency is obtained by dividing the total number of photons emitted from the element by the number of carriers injected into the element. The full width at half maximum of the emission spectrum is determined as the width between the wavelengths above and below the maximum emission wavelength where the intensity is 50%.

[0615] A DC voltage was applied to the ITO electrode as the anode and the LiF / aluminum electrode as the cathode, resulting in a reading of 1000 cd / m². 2 We measured the characteristics of the light emission (emission wavelength, external quantum efficiency). We also measured the time (lifetime) during which the light emission was maintained at 50% or more of the initial brightness. The results are shown in Tables 3 and 4.

[0616] [Table 3] TIFF2026095336000232.tif137170

[0617] [Table 4] TIFF2026095336000234.tif137170

[0618] The results obtained indicate that the element in the example has a longer lifespan compared to the element in the comparative example which uses a compound with a corresponding skeleton to the compound in the example, demonstrating that the compound offers both high efficiency and a long lifespan. [Explanation of symbols]

[0619] 100 Organic Electroluminescent Devices 101 circuit board 102 Anode 103 Hole injection layer 104 Hole transport layer 105 Light-emitting layer 106 Electron transport layer 107 Electron injection layer 108 Cathode

Claims

1. Polycyclic aromatic compounds represented by formula (I); 【Chemistry 1】 In formula (I), Rings A, B, D, and E are each independently a substituted or unsubstituted aryl ring or a substituted or unsubstituted heteroaryl ring, wherein at least one selected from the group consisting of rings A, B, c, D, and E is an aryl ring having at least cyano as a substituent or a heteroaryl ring having at least cyano as a substituent. Z ０ is -C(-R Ｚ０ ) = or -N = R Ｚ０ Each is independently either hydrogen or a substituent. Y is independently B, P, P=O, or P=S. X １ 、 X ２ 、 X ３ 、 and X ４ are each independently > N - R ＮＸ , > O, > S or > Se, and R ＮＸ is hydrogen, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted alkyl, or substituted or unsubstituted cycloalkyl, R ＮＸ It may be bonded to at least one of the A or B rings, at least one of the A or c rings, at least one of the B or D rings, or at least one of the c or E rings via a single bond or a linking group. However, X １ , X ２ , X ３ , and X ４ It satisfies at least one of the following (a) and (b): (a) X １ and X ２ Each of them operates independently, R ＮＸ The group represented by formula (Ar) is N-R ＮＸ It is; (b) X １ and X ３ Each is R ＮＸ N-R is mesityl ＮＸ is or X ２ and X ４ Each is R ＮＸ N-R is mesityl ＮＸ That is, In the formula (Ar), * indicates the bond position to nitrogen. The F ring is a substituted or unsubstituted aryl ring or a substituted or unsubstituted heteroaryl ring, and includes at least a six-membered ring containing the atom to which G is bonded as a ring constituent atom. G is a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted arylthio, a substituted or unsubstituted heteroarylthio, a substituted or unsubstituted aryloxy, a substituted or unsubstituted heteroaryloxy, a substituted or unsubstituted alkyl, or a substituted or unsubstituted cycloalkyl. At least one selected from the group consisting of aryl rings and heteroaryl rings in formula (I) may be condensed with at least one cycloalkane, and the cycloalkane may be substituted with at least one substituent, and at least one -CH group in the cycloalkane ２ The hyphen can be replaced with -O-, In formula (I), at least one hydrogen may be replaced by deuterium, and at least one nitrogen may be nitrogen-15( １５ N) may be replaced by sulfur-33( ３３ S), Sulfur-34 ( ３４ S) or Sulfur-36 ( ３６ S), at least one oxygen, oxygen-17 ( １７ O) or oxygen-18 ( １８ O), at least one carbon is carbon-13 ( １３ C), at least one boron is boron-11 ( １１ B) can be used as a substitute.

2. A polycyclic aromatic compound according to claim 1, represented by formula (II); 【Chemistry 2】 In formula (II), Z ０ Z in equation (I) ０ It is synonymous with, X ３ and X ４ X in equation (I) ３ and X ４ These are synonymous, Ar is a base represented by the formula (Ar), Z and Q are independently -C(-R Ｚ ) = or -N = and R Ｚ is hydrogen or a substituent, At least one Q is -C(-CN) =.

3. A polycyclic aromatic compound according to claim 2, represented by formulas (II-1-i) to (II-1-v), (II-2-i), (II-2-ii), (II-3-i), (II-3-ii), (II-4-i), or (II-5-i); 【Transformation 3】 In the above formula, Z ０ And Ar is Z in equation (II). ０ And are synonymous with Ar, respectively. Z is independent of each other, -C(-R Ｚ ) = or -N = and R Ｚ is hydrogen or a substituent.

4. The polycyclic aromatic compound according to claim 1, wherein the F ring is a substituted or unsubstituted benzene ring, a dibenzofuran ring, or a dibenzothiophene ring.

5. X １ , X ２ , X ３ , and X ４ (b) satisfies, X １ , X ２ , X ３ , and X ４ All of them are > N-R ＮＸ The polycyclic aromatic compound according to claim 1.

6. A polycyclic aromatic compound according to claim 1, represented by any of the following formulas. 【Chemistry 4】 【Transformation 5】 【Transformation 6】 【Transformation 7】 【Transformation 8】

7. An organic field light-emitting device having a pair of electrodes consisting of an anode and a cathode, and an organic layer disposed between the pair of electrodes, wherein the organic layer contains a polycyclic aromatic compound according to any one of claims 1 to 6.

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 comprises at least one selected from the group consisting of assisting dopants and phosphorescent materials.

10. A display device or lighting device comprising an organic electroluminescent element as described in claim 7.

11. A wavelength conversion material containing a polycyclic aromatic compound according to any one of claims 1 to 6.

12. An organic photodiode comprising a pair of electrodes and an active layer disposed between the pair of electrodes, wherein the active layer comprises a polycyclic aromatic compound according to any one of claims 1 to 6.

13. The organic photodiode according to claim 12, wherein the active layer is made of the polycyclic aromatic compound.

14. A solar cell material containing a polycyclic aromatic compound according to any one of claims 1 to 6.

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