Polycyclic aromatic compounds

Abstract

This invention provides compounds for forming highly efficient and long-life organic EL elements. [Solution] A polycyclic aromatic compound represented by formula (4) is provided. TIFF2026143644000234.tif39170 (In the formula, rings A, B, D, C, and E are optionally substituted aryl rings or optionally substituted heteroaryl rings, Y is B, n is 0 or 1, X is >NR, >O, >Si(-R)2>S, or >Se, R is optionally substituted aryl, etc., and at least one selected from the group consisting of aryl rings and heteroaryl rings in the above polycyclic aromatic compound may be condensed with at least one cycloalkane, and at least one hydrogen atom in the above polycyclic aromatic compound may be substituted with deuterium, cyano, or halogen.)

Description

[Technical Field]

[0001] The present invention relates to polycyclic aromatic compounds. The present invention also relates to materials for organic devices, organic electroluminescent devices, and display devices and lighting devices containing the above-mentioned polycyclic aromatic compounds. [Background technology]

[0002] Conventionally, display devices using electroluminescent light-emitting elements have been studied extensively due to their potential for power saving and miniaturization. Furthermore, organic electroluminescent elements made of organic materials (sometimes referred to as "organic EL elements" or simply "elements" in this specification) have been actively investigated due to their ease of weight reduction and scaling up. In particular, the development of organic materials with luminescence properties such as blue, one of the three primary colors of light, and the development of organic materials with charge transport capabilities such as holes and electrons (potentially becoming semiconductors or superconductors) have been actively researched, regardless of whether they are polymer compounds or low molecular weight compounds.

[0003] Organic EL elements 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 (sometimes referred to as "organic layers" herein) include light-emitting layers and charge transport / injection layers that transport or inject charges such as holes and electrons, and various organic materials suitable for these layers have been developed.

[0004] In particular, Patent Document 1 discloses that polycyclic aromatic compounds, in which aromatic rings are linked by heteroatoms such as boron, phosphorus, oxygen, nitrogen, and sulfur, are useful as materials for organic electroluminescent devices and the like. These polycyclic aromatic compounds have a large HOMO-LUMO gap and a high lowest excitation triplet energy level (E T It has been reported to be particularly useful as a fluorescent material for organic electroluminescent devices because it possesses the properties of ) and exhibits thermally activated delayed fluorescence. [Prior art documents] [Patent Documents]

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

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

[0007] The inventors of the present invention diligently studied to solve the above problems and succeeded in producing a new compound as a polycyclic aromatic compound in which aromatic rings are linked by heteroatoms such as boron, phosphorus, oxygen, nitrogen, and sulfur. Furthermore, they discovered that an excellent organic EL element can be obtained by arranging a layer containing this polycyclic aromatic compound between a pair of electrodes to construct an organic EL element, thus completing the present invention. In other words, the present invention provides the following polycyclic aromatic compounds, and further, materials for organic devices containing the following polycyclic aromatic compounds.

[0008] <1> Polycyclic aromatic compounds represented by formula (4); [ka]

[0009] In formula (4), Rings A, B, D, C, and E are each independently a substituted or substituted aryl ring or a substituted heteroaryl ring. Y is independently B, P, P=O, or P=S. n is either 0 or 1, independently of each other. X is independently >C(-R)2, >NR, >O, >Si(-R)2>S, or >Se, In X, R in >NR is an optionally substituted aryl, optionally substituted heteroaryl, optionally substituted alkyl, or optionally substituted cycloalkyl, and in X, R in >C(-R)2 and >Si(-R)2 is hydrogen, optionally substituted aryl, optionally substituted alkyl, or optionally substituted cycloalkyl, and the two Rs in >C(-R)2 and >Si(-R)2 may be bonded to each other to form a ring, and at least one of the Rs in >NR, >C(-R)2, and >Si(-R)2 may be bonded to at least one of the A, B, C, D, or E rings by a linking group or single bond. At least one selected from the group consisting of aryl rings and heteroaryl rings in the polycyclic aromatic compound may be condensed with at least one cycloalkane, at least one hydrogen in the cycloalkane may be substituted, and at least one -CH2- in the cycloalkane may be substituted with -O-. At least one hydrogen atom in the polycyclic aromatic compound may be substituted with deuterium, cyano, or halogen.

[0010] <2> Y is always B. <1> The polycyclic aromatic compounds described above. <3> A substituent in an optionally substituted aryl ring or optionally substituted heteroaryl ring, which is ring A, B, D, C, or E, is optionally alkyl-substituted aryl, optionally alkyl-substituted diarylamino, or alkyl. <1> or <2> The polycyclic aromatic compounds described above. <4> The A, B, D, C, and E rings are benzene rings, and each of them may have substituents. <1> ~ <3> A polycyclic aromatic compound as described in any of the following. <5> n is 1 in all cases. <1> ~ <4> A polycyclic aromatic compound as described in any of the following.

[0011] <6> Expressed by one of the following formulas: <1> Polycyclic aromatic compounds as described above; [ka]

[0012] [ka]

[0013] [ka]

[0014] [ka] In the formula, Me represents methyl and tBu represents t-butyl.

[0015] <7> <1> ~ <6> A material for organic devices containing a polycyclic aromatic compound as described in any of the above. <8> The aforementioned organic device material is a material for an organic field-effect light-emitting device, a material for an organic field-effect transistor, or a material for an organic thin-film solar cell. <7> Materials for organic devices as described above. <9> The aforementioned material for the organic electroluminescent element is a material for the light-emitting layer. <8> Materials for organic devices as described above. <10> A pair of electrodes consisting of an anode and a cathode, and a device placed between the pair of electrodes, <1> ~ <6> An organic electroluminescent element having an organic layer containing a polycyclic aromatic compound as described in any of the above. <11> The aforementioned organic layer is a light-emitting layer. <10> Organic electroluminescent device as described above. <12> The light-emitting layer comprises a host material and the polycyclic aromatic compound as a dopant material. <11> Organic electroluminescent device as described above. <13> The host material is a compound having a lowest excited triplet energy level at least 0.01 eV higher than the lowest excited triplet energy level of the polycyclic aromatic compound. <12> Organic electroluminescent device as described above. <14> <10> ~ <13> A display device or lighting device equipped with an organic electroluminescent element as described in any of the above. [Effects of the Invention]

[0016] The present invention provides novel polycyclic aromatic compounds. The polycyclic aromatic compounds of the present invention are useful as materials for organic devices, particularly as materials for light-emitting layers in organic electroluminescent devices. [Brief explanation of the drawing]

[0017] [Figure 1] This is a schematic cross-sectional view showing an example of an organic EL element. [Figure 2] This is an energy level diagram showing the energy relationships between the host, assisting dopant, and emitting dopant of a TAF device using a common fluorescent dopant. [Figure 3] This is an energy level diagram showing an example of the energy relationship between the host, assisting dopant, and emitting dopant in an organic electroluminescent element according to one aspect of the present invention. [Figure 4] This diagram illustrates a method for fabricating organic EL elements on a substrate with a bank using an inkjet method. [Modes for carrying out the invention]

[0018] 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)". 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).

[0019] 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.

[0020] 1. Polycyclic aromatic compounds 1-1. Polycyclic aromatic compounds The polycyclic aromatic compound of the present invention is a polycyclic aromatic compound represented by formula (4).

[0021] [ka]

[0022] Polycyclic aromatic compounds represented by formula (4) are useful as compounds for forming highly efficient and long-life organic EL devices. In particular, polycyclic aromatic compounds represented by formula (4) have high TADF properties. For good TADF performance, 1) the difference between the lowest excited singlet energy and the lowest excited triplet energy (|E S1 -E T1 |, ΔE S1T11) requires a small ) and a large spin-orbit interaction. 1) requires the separation and localization of the HOMO and LUMO, which in polycyclic aromatic compounds represented by formula (4) can be achieved by optimizing substituents on X, Y, and the aryl and heteroaryl rings in the A, B, C, D, and E rings of formula (4). More specifically, this could involve optimization to enhance multiple resonance effects, or optimization to utilize the separation of orbitals by donor and acceptor structures. 2) in polycyclic aromatic compounds represented by formula (4) can be achieved by adopting a stereostructure that increases spin angular momentum, introducing heavy atoms into the molecule, or combining these. Furthermore, polycyclic aromatic compounds represented by formula (4) are less prone to decomposition during vapor deposition compared to similar compounds with comparable molecular weights.

[0023] In equation (4), "A", "B", "C", "D", and "E" are symbols indicating a ring structure. n is independently either 0 or 1. The ring A and ring D are connected by -(X). n When n is 1, we show that rings A and D are joined by a linking group X, and when n is 0, we show that rings A and D are joined by a single bond. Rings B and C are linked by -(X). n When n is 1 in -, it indicates that the B ring and the C ring are joined by a linking group X, and when n is 0, it indicates that the B ring and the C ring are joined by a single bond. The A ring, B ring, C ring, D ring, and E ring are each independently substituted or substituted aryl rings or heteroaryl rings.

[0024] Rings A, B, C, D, and E are preferably bonded to Y in a 5-membered or 6-membered ring. Also, in the same 5-membered or 6-membered ring, N or -(X) nIt is preferable that the group is bonded to. Here, the phrase "bonded in a 5-membered ring or 6-membered ring" means that a ring is formed only by the 5-membered ring or 6-membered ring, or another ring or the like is further condensed to include the 5-membered ring or 6-membered ring to form an aryl ring or a heteroaryl ring in ring A, ring B, ring C, ring D or ring E, and Y (and N or -(X) n -) is bonded to a ring-constituting atom on the 5-membered ring or 6-membered ring.

[0025] In formula (4), Y and N or -(X) bonded to the same ring n - only need to be respectively bonded to mutually adjacent ring-constituting atoms.

[0026] Examples of the "aryl ring" in ring A, ring B, ring C, ring D and ring E include aryl rings having 6 to 30 carbon atoms, with aryl rings having 6 to 16 carbon atoms being preferred, aryl rings having 6 to 12 carbon atoms being more preferred, and aryl rings having 6 to 10 carbon atoms being particularly preferred.

[0027] Specific examples of the "aryl ring" include benzene ring which is a monocyclic system, biphenyl ring which is a bicyclic system, naphthalene ring and indene ring which are fused bicyclic systems, terphenyl ring (m-terphenyl, o-terphenyl, p-terphenyl) which is a tricyclic system, acenaphthylene ring, fluorene ring, phenalene ring, phenanthrene ring and anthracene ring which are fused tricyclic systems, triphenylene ring, pyrene ring, naphthacene ring and chrysene ring which are fused tetracyclic systems, and perylene ring and pentacene ring which are fused pentacyclic systems. In addition, fluorene ring, benzofluorene ring and indene ring also include structures in which fluorene ring, benzofluorene ring, cyclopentane ring and the like are spiro-bonded respectively. Furthermore, fluorene ring, benzofluorene ring and indene ring also include those in which two of the two hydrogen atoms of methylene are each substituted with an alkyl such as methyl as the first substituent described below to form dimethylfluorene ring, dimethylbenzofluorene ring, dimethylindene ring and the like.

[0028] Examples of "heteroaryl rings" in rings A, B, C, D, and E include 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. Examples of "heteroaryl rings" include heterocycles containing 1 to 5 heteroatoms selected from oxygen, sulfur, and nitrogen in addition to carbon as ring constituent atoms.

[0029] Specific examples of "heteroaryl rings" include pyrrole rings, oxazole rings, isoxazole rings, thiazole rings, isothiazole rings, imidazole rings, oxadiazole rings, thiadiazole rings, triazole rings, tetrazole rings, pyrazole rings, pyridine rings, pyrimidine rings, pyridazine rings, pyrazine rings, triazine rings, indole rings, isoindole rings, 1H-indazole rings, benzimidazole rings, benzoxazole rings, benzothiazole rings, 1H-benzotriazole rings, quinoline rings, isoquinoline rings, sinnoline rings, quinazoline rings, quinoxaline rings, phthalazine rings, naphthyridine rings, purine rings, and pteridine rings. Examples include carbazole rings, acridine rings, phenoxatiin rings, phenoxazine rings, phenothiazine rings, phenazine rings, phenazacillin rings, indidine rings, furan rings, benzofuran rings, isobenzofuran rings, dibenzofuran rings, thiophene rings, benzothiophene rings, dibenzothiophene rings, furazan rings, thianthlene rings, indolocarbazole rings, benzoindolocarbazole rings, benzobenzoindolocarbazole rings, naphthobenzofuran rings, dioxin rings, dihydroacridine rings, xanthene rings, thioxanthene rings, dibenzodioxin rings, dibenzazepine rings, tribenzoazepine rings, and iminodibenzyl rings. Furthermore, for dihydroacridine rings, xanthene rings, and thioxanthene rings, it is also preferable that two of the two hydrogen atoms of the methylene ring are substituted with 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."

[0030] When at least one hydrogen in the above aryl ring or heteroaryl ring is substituted with a substituent, the substituent is preferably a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted diarylamino, a substituted or unsubstituted diheteroarylamino, a substituted or unsubstituted arylheteroarylamino (an amino having an aryl and a heteroaryl), a substituted or unsubstituted diarylboryl (the two aryls may be linked by a single bond or a linking group), a substituted or unsubstituted alkyl, a substituted or unsubstituted cycloalkyl, a substituted or unsubstituted alkoxy, a substituted or unsubstituted aryloxy, a substituted silyl, or -L-Ak. When these groups have substituents, examples of substituents include aryl, heteroaryl, alkyl or cycloalkyl, or diarylamino.

[0031] At least one hydrogen in the above-mentioned "aryl ring" or "heteroaryl ring" may be substituted with a first substituent, which is a substituted or unsubstituted "aryl", a substituted or unsubstituted "heteroaryl", a substituted or unsubstituted "diarylamino", a substituted or unsubstituted "diheteroarylamino", a substituted or unsubstituted "arylheteroarylamino", a substituted or unsubstituted "diarylboryl (the two aryls may be linked by a single bond or a linking group)", a substituted or unsubstituted "alkyl", a substituted or unsubstituted "cycloalkyl", a substituted or unsubstituted "alkoxy", a substituted or unsubstituted "aryloxy", a substituted "silyl", or -L-Ak. Examples of this first substituent include the monovalent group of the above-mentioned "aryl ring" or "heteroaryl ring", such as "aryl", "heteroaryl", "diarylamino", "heteroaryl", "aryl and heteroaryl", "arylheteroarylamino", "diarylboryl", and "aryloxy".

[0032] Specifically, examples of "aryls" include aryls having 6 to 30 carbon atoms, preferably aryls having 6 to 24 carbon atoms, more preferably aryls having 6 to 20 carbon atoms, even more preferably aryls having 6 to 16 carbon atoms, particularly preferably aryls having 6 to 12 carbon atoms, and most preferably aryls having 6 to 10 carbon atoms.

[0033] Specific examples of aryls include, for instance, the monocyclic aryl phenyl, the bicyclic aryl (2-,3-,4-)biphenylyl, the condensed bicyclic aryls (1-,2-)naphthyl, (2-,3-,4-,5-,6-,7-)indenyl, and the tricyclic aryl terpheniryl (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, p-terphenyl (Lu-4-yl), the condensed tricyclic aryls are acenaphthylene-(1-,3-,4-,5-)yl, fluoren-(1-,2-,3-,4-,9-)yl, phenalen-(1-,2-)yl, (1-,2-,3-,4-,9-)phenanthryl, and the tetracyclic aryl is quaterpheniryl (5'-phenyl-m-terphenyl-2-yl, 5'-phenyl-m-terphenyl Examples include ru-3-yl, 5'-phenyl-m-terphenyl-4-yl, m-quaterphenylyl), the condensed tetracyclic aryls triphenylene-(1-,2-)yl, pyren-(1-,2-,4-)yl, naphthasen-(1-,2-,5-)yl, and the condensed pentacyclic aryls perylene-(1-,2-,3-)yl, pentasene-(1-,2-,5-,6-)yl.

[0034] Furthermore, examples of "heteroaryls" include heteroaryls having 2 to 30 carbon atoms, with heteroaryls having 2 to 25 carbon atoms being preferred, heteroaryls having 2 to 20 carbon atoms being more preferred, heteroaryls having 2 to 15 carbon atoms being even more preferred, and heteroaryls having 2 to 10 carbon atoms being particularly preferred. Examples of heteroaryls include heterocycles containing 1 to 5 heteroatoms selected from oxygen, sulfur, and nitrogen in addition to carbon as ring constituent atoms.

[0035] Specific heteroaryls include, for example, furyl, thienyl, pyrrolyl, oxazolyl, isoxazolyl, thiazolyl, isothiazolyl, imidazolyl, pyrazolyl, oxadiazolyl, flazanil, thiadiazolyl, triazolyl, tetrazolyl, pyridyl, pyrimidinyl, pyridazinyl, pyrazinyl, triazinyl, benzofuranil, isobenzofuranil, dibenzofuranil, benzo[b]thienyl, dibenzothienyl, and yin. Examples include drill, isoindolyl, 1H-indazolyl, benzimidazolyl, benzoxazolyl, benzothiazolyl, 1H-benzotriazolyl, quinolyl, isoquinolyl, cinnolyl, quinazolyl, quinoxalinyl, phthalazinyl, naphthilidinyl, prinyl, pteridinyl, carbazolyl, acridinyl, phenoxazinyl, phenothiazinyl, phenazinyl, phenoxathiinyl, thianthrenyl, and indolidinyl.

[0036] Furthermore, the "alkyl" as the first substituent may be either linear or branched, for example, a linear alkyl having 1 to 24 carbon atoms or a branched alkyl having 3 to 24 carbon atoms. A C1 to 18 alkyl (a branched alkyl having 3 to 18 carbon atoms) is preferred, a C1 to 12 alkyl (a branched alkyl having 3 to 12 carbon atoms) is more preferred, a C1 to 8 alkyl (a branched alkyl having 3 to 8 carbon atoms) is even more preferred, a C1 to 6 alkyl (a branched alkyl having 3 to 6 carbon atoms) is particularly preferred, and a C1 to 5 alkyl (a branched alkyl having 3 to 5 carbon atoms) is most preferred.

[0037] Specific alkyl groups include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, s-butyl, t-butyl, n-pentyl, isopentyl, neopentyl, t-pentyl(t-amyl), n-hexyl, 1-methylpentyl, 4-methyl-2-pentyl, 3,3-dimethylbutyl, 2-ethylbutyl, n-heptyl, 1-methylhexyl, n-octyl, and t-octyl(1,1,3,3-tetramethylbutyl) Examples include 1-methylheptyl, 2-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.

[0038] Other examples include 1-ethyl-1-methylpropyl, 1,1-diethylpropyl, 1,1-dimethylbutyl, 1-ethyl-1-methylbutyl, 1,1,4-trimethylpentyl, 1,1,2-trimethylpropyl, 1,1-dimethyloctyl, 1,1-dimethylpentyl, 1,1-dimethylheptyl, 1,1,5-trimethylhexyl, 1-ethyl-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.

[0039] As substituents containing the above-mentioned "alkyl," the tertiary-alkyl represented by the following formula (tR) is one of the particularly preferred substituents when at least one hydrogen in the above-mentioned aryl ring or heteroaryl ring is substituted with a substituent. This is because such bulky substituents increase the intermolecular distance, thereby improving the luminescence quantum yield (PLQY). Furthermore, substituents in which the tertiary-alkyl represented by formula (tR) is substituted with another substituent as a second substituent are also preferred. Specifically, examples include diarylamino substituted with the tertiary-alkyl represented by (tR), carbazolyl (preferably N-carbazol) substituted with the tertiary-alkyl represented by (tR), or benzocarbazol (preferably N-benzocarbazol) substituted with the tertiary-alkyl represented by (tR). For "diarylamino," the group described below as the "first substituent" is an example. Examples of substitutions of the (tR) group on diarylamino, carbazolyl, and benzocarbazolyl groups include cases where some or all of the hydrogen atoms in the aryl or benzene ring of these groups are substituted with the (tR) group.

[0040] [ka]

[0041] 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 * indicates the bond position.

[0042] 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).

[0043] 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.

[0044] 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.

[0045] 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.

[0046] Examples of "cycloalkyl" as the first substituent include cycloalkyl groups with 3 to 24 carbon atoms, 3 to 20 carbon atoms, 3 to 16 carbon atoms, 3 to 14 carbon atoms, 5 to 10 carbon atoms, 5 to 8 carbon atoms, 5 to 6 carbon atoms, and 5 carbon atoms.

[0047] Specific examples of cycloalkyls include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl, and their alkyl (especially methyl) substituted derivatives having 1 to 5 carbon atoms, as well as norbornyl (bicyclo[2.2.1]heptyl), 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[2.2.2]octyl, adamantyl, diamantyl, decahydronaphthalenyl, and decahydroazlenyl.

[0048] As the first substituent, "alkoxy" can be, for example, a linear alkoxy having 1 to 24 carbon atoms or a branched alkoxy having 3 to 24 carbon atoms. An alkoxy having 1 to 18 carbon atoms (a branched alkoxy having 3 to 18 carbon atoms) is preferred, an alkoxy having 1 to 12 carbon atoms (a branched alkoxy having 3 to 12 carbon atoms) is more preferred, an alkoxy having 1 to 6 carbon atoms (a branched alkoxy having 3 to 6 carbon atoms) is even more preferred, and an alkoxy having 1 to 5 carbon atoms (a branched alkoxy having 3 to 5 carbon atoms) is particularly preferred.

[0049] Specific examples of alkoxys include methoxy, ethoxy, propoxy, isopropoxy, butoxy, isobutoxy, s-butoxy, t-butoxy, t-amyloxy, pentyloxy, hexyloxy, heptyloxy, and octyloxy.

[0050] Furthermore, as the first substituent, a "substituted silyl" can be a silyl substituted with three substituents selected from the group consisting of alkyl, cycloalkyl, and aryl. Examples include trialkylsilyl, tricycloalkylsilyl, dialkylcycloalkylsilyl, alkyldicycloalkylsilyl, triarylsilyl, dialkylarylsilyl, and alkyldiarylsilyl.

[0051] "Trialkylsilyl" refers to a group in which the three hydrogen atoms of the silyl group are each independently substituted with an alkyl group. This alkyl group can be the same group described as "alkyl" in the first substituent mentioned above. Preferred alkyl groups for substitution are those having 1 to 5 carbon atoms, specifically including methyl, ethyl, propyl, i-propyl, butyl, sec-butyl, t-butyl, and t-amyl.

[0052] Specific examples of trialkylsilyls include trimethylsilyl, triethylsilyl, tripropylsilyl, tri-i-propylsilyl, tributylsilyl, trisec-butylsilyl, tri-t-butylsilyl, tri-t-amylsilyl, ethyldimethylsilyl, propyldimethylsilyl, i-propyldimethylsilyl, butyldimethylsilyl, sec-butyldimethylsilyl, t-butyldimethylsilyl, t-amyldimethylsilyl, methyldiethylsilyl, propyldiethylsilyl, i-propyldiethylsilyl, buty Examples include dipropylsilyl, sec-butyldiethylsilyl, t-butyldiethylsilyl, t-amyldiethylsilyl, methyldipropylsilyl, ethyldipropylsilyl, butyldipropylsilyl, sec-butyldipropylsilyl, t-butyldipropylsilyl, t-amyldipropylsilyl, methyldi-i-propylsilyl, ethyldi-i-propylsilyl, butyldi-i-propylsilyl, sec-butyldi-i-propylsilyl, t-butyldi-i-propylsilyl, and t-amyldi-i-propylsilyl.

[0053] "Tricycloalkylsilyl" refers to a group in which each of the three hydrogen atoms in the silyl group is independently substituted with a cycloalkyl group. This cycloalkyl group can be the same as the "cycloalkyl" group described above in the first substituent. Preferred cycloalkyl groups for substitution are those having 5 to 10 carbon atoms, specifically 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, bicyclo[2.2.2]octyl, adamantyl, decahydronaphthalenyl, decahydroazlenyl, and the like.

[0054] Specific examples of tricycloalkylsilyls include tricyclopentylsilyl and tricyclohexylsilyl.

[0055] Specific examples of dialkylcycloalkylsilyls substituted with two alkyl groups and one cycloalkyl group, and alkyldicycloalkylsilyls substituted with one alkyl group and two cycloalkyl groups, include silyls substituted with groups selected from the specific alkyl and cycloalkyl groups mentioned above.

[0056] Specific examples of dialkylarylsilyls, alkyldiarylsilyls, and triarylsilyls, which are substituted with two alkyl groups and one aryl group, respectively, include silyls substituted with groups selected from the specific alkyl and aryl groups mentioned above. A particularly specific example of a triarylsilyl is triphenylsilyl.

[0057] Furthermore, the explanation of aryl in the first substituent "diarylboryl" can be referenced from the explanation of aryl described above. These two aryls may also be linked by a single bond or a linking group (e.g., >C(-R)2, >O, >S, or >NR). Here, R in >C(-R)2 and >NR is aryl, heteroaryl, diarylamino, alkyl, cycloalkyl, alkoxy, or aryloxy (the above are the first substituents), and the first substituent may be further substituted with aryl, heteroaryl, alkyl, or cycloalkyl (the above are the second substituents). Specific examples of these groups can be referenced from the explanation of aryl, heteroaryl, diarylamino, alkyl, cycloalkyl, alkoxy, or aryloxy as first substituents described above.

[0058] In the first substituent -L-Ak, L is >NR, >O, or >S, and R in >NR is an optionally substituted aryl, optionally substituted heteroaryl, optionally substituted alkyl, or optionally substituted cycloalkyl. Furthermore, R in >NR may be bonded to Ak by a linking group or a single bond.

[0059] Ak is hydrogen, an optionally substituted alkyl group, or an optionally substituted cycloalkyl group, wherein at least one hydrogen in the alkyl group and cycloalkyl group may be substituted, and at least one -CH2- group in the alkyl group and cycloalkyl group may be substituted with -O- and -S- groups.

[0060] It is preferable that L is >NR. When L is >NR, R 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.

[0061] 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.

[0062] When L is >NR, R may be bonded to Ak by a linking group or a single bond. Examples of linking groups in this case include >O, >S, or >Si(-R)2. In >Si(-R)2, R is hydrogen, an aryl group with 6 to 12 carbon atoms, an alkyl group with 1 to 6 carbon atoms, or a cycloalkyl group with 3 to 14 carbon atoms. Examples of structures in which R in >NR is bonded to Ak by a linking group or a single bond are given below.

[0063] [ka]

[0064] In each of the above formulas, Me is methyl and is bonded at the position of * to a ring-constituting atom of the aryl or heteroaryl ring in ring A, B, C, D, or E.

[0065] The first substituents, which are substituted or unsubstituted "aryl", substituted or unsubstituted "heteroaryl", substituted or unsubstituted "diarylamino", substituted or unsubstituted "diheteroarylamino", substituted or unsubstituted "arylheteroarylamino", substituted or unsubstituted "diarylboryl (the two aryls may be linked by a single bond or a linking group)", substituted or unsubstituted "alkyl", substituted or unsubstituted "cycloalkyl", substituted or unsubstituted "alkoxy", substituted or unsubstituted "aryloxy", or substituted "silyl", may have at least one hydrogen substituted by the second substituent, as described as substituted or unsubstituted. Examples of this second substituent include aryl, heteroaryl, alkyl, or cycloalkyl, and specific examples can be found in the descriptions of the monovalent group of the "aryl ring" or "heteroaryl ring" and the "alkyl" or "cycloalkyl" as first substituents described above. Furthermore, aryl and heteroaryl structures with a second substituent also include those in which at least one hydrogen is substituted with an aryl group such as phenyl (specific examples are the groups mentioned above), an alkyl group such as methyl or t-butyl (specific examples are the groups mentioned above), or a cycloalkyl group such as cyclohexyl (specific examples are the groups mentioned above). For example, in the case of a carbazolyl with a second substituent, a carbazolyl in which at least one hydrogen at the 9-position is substituted with an aryl group such as phenyl, an alkyl group such as methyl, or a cycloalkyl group such as cyclohexyl is also included as a heteroaryl structure with a second substituent.

[0066] The emission wavelength can be adjusted by the steric hindrance, electron-donating, and electron-withdrawing properties of the structure of the first substituent. 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 (especially N-carbazolyl), 3,6-dimethylcarbazol These are lyl, 3,6-di-t-butylcarbazol and phenoxy, and more preferably methyl, t-butyl, t-amyl, t-octyl, neopentyl, adamantyl, phenyl, o-tolyl, 2,6-xylyl, 2,4,6-mesityl, diphenylamino, di-p-tolylamino, bis(p-(t-butyl)phenyl)amino, carbazolyl, 3,6-dimethylcarbazol and 3,6-di-t-butylcarbazol. 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.

[0067] In the structural formula below, "Me" represents methyl, "tBu" represents t-butyl, "tAm" represents t-amyl, "tOct" represents t-octyl, and * represents the bond position. [ka]

[0068] [ka]

[0069] [ka]

[0070]

change

[0071]

change

[0072]

change

[0073]

change

[0074]

change

[0075]

change

[0076]

change

[0077]

change

[0078]

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[0079]

change

[0080]

change

[0081] [ka]

[0082] When two or three hydrogen atoms bonded to consecutive (adjacent) carbon atoms are substituted, the substituent may be a group represented by formula (A20).

[0083] [ka]

[0084] In formula (A20), L S >NR, >O, >Si(-R)2 or >S, where R in >NR is an optionally substituted aryl, optionally substituted heteroaryl, optionally substituted alkyl or optionally substituted cycloalkyl, and R in >Si(-R)2 is hydrogen, optionally substituted aryl, optionally substituted alkyl or optionally substituted cycloalkyl, and they may be bonded to each other to form a ring, and at least one of the >NR and R in >Si(-R)2 is a linking group or single bond to an A ring, B ring, C ring, D ring, E ring and R S It may be combined with at least one selected from the group consisting of, r is an integer from 1 to 4, R S Each is independently hydrogen, an optionally substituted alkyl, or an optionally substituted cycloalkyl, and any R S is any other R S They may be connected to each other by linking groups or single bonds. The group represented by formula (A20) is bonded by two * to two adjacent atoms on an aryl ring, heteroaryl ring, or cycloalkane ring, respectively.

[0085] When the compound of the present invention contains a group represented by formula (A20), the number of such groups is preferably 1 or 2. The group represented by formula (A20) may be a substituent on any one of ring A, ring B, ring C, ring D and ring E.

[0086] The group represented by formula (A20) is bonded via two * to two adjacent atoms on an aryl ring or a heteroaryl ring, respectively. It is preferable that the group represented by formula (A20) is bonded via two * to two adjacent atoms on an aryl ring or a heteroaryl ring, respectively. At this time, it is preferable that both of the two adjacent atoms on the ring are carbon atoms. A fused ring structure is formed when the group represented by formula (A20) is bonded to an aryl ring or a heteroaryl ring. The compound represented by formula (4) having this fused ring structure has a more rigid structure. When the structure becomes rigid, molecular vibration is suppressed to improve EQE, and it is expected that molecular stability increases and the device lifespan becomes longer.

[0087] In formula (A20), L S is >N-R, >O, >Si(-R)2 or >S. By selecting the type of L S in the group represented by formula (A20), it is possible to control the HOMO and LUMO of the compound of the present invention. When L S is N-R, >O or >S, the HOMO and LUMO become shallower; when L is Si, the HOMO and LUMO become deeper. When HOMO and LUMO become shallower, it is expected that a TTF device using the compound will have long lifespan, high efficiency and low driving voltage. On the other hand, when HOMO and LUMO become deeper, the hole trapping property of the dopant is eliminated, and it is expected that the driving voltage will be greatly reduced.

[0088] L in formula (A20) S In >N-R which is , R is optionally substituted aryl, optionally substituted heteroaryl, optionally substituted alkyl or optionally substituted cycloalkyl. L in formula (A20) Sin >Si(-R)2, each R is hydrogen, optionally substituted aryl, optionally substituted alkyl or optionally substituted cycloalkyl, and two R groups may be bonded to each other to form a ring. In addition, at least one of R in said >N-R and said >Si(-R)2 is bonded to ring A, ring B, ring C, ring D, ring E and R via a linking group or a single bond S may be bonded to at least one selected from the group consisting of. L is preferably >N-R, >O or >S, more preferably >N-R or >O, and still more preferably >N-R.

[0089] L S when L is >N-R, R is preferably aryl optionally substituted by alkyl or cycloalkyl, heteroaryl optionally substituted by alkyl or cycloalkyl, alkyl or cycloalkyl, more preferably aryl optionally substituted by alkyl or cycloalkyl, or heteroaryl optionally substituted by alkyl or cycloalkyl, still more preferably aryl optionally substituted by alkyl or cycloalkyl, and particularly preferably phenyl optionally substituted by alkyl or cycloalkyl.

[0090] In formula (A20), r is an integer of 1 to 4, preferably 2 or 3, more preferably 2. In formula (A20), R S are each independently hydrogen, optionally substituted alkyl or optionally substituted cycloalkyl, and any R S may be bonded to any other R S to each other via a linking group or a single bond.

[0091] R SPreferably, any two atoms are bonded to each other by a linking group or a single bond. Examples of linking groups include >O and >S. 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-. Preferred divalent groups formed by bonding to each other are linear alkylenes having 2 to 5 carbon atoms, more preferably linear alkylenes having 3 or 4 carbon atoms, and even more preferably linear alkylenes having 4 carbon atoms (-(CH2)4-). It is particularly preferable that the linear alkylenes having 4 carbon atoms (-(CH2)4-) are unsubstituted.

[0092] Two R atoms bonded to adjacent carbon atoms. S When R is linked to each other by a linking group or single bond, the remaining R that is not involved in this bond S Each is independently a hydrogen atom or an optionally substituted alkyl group, or L S It is preferable that it is bonded to R in >NR or >Si(-R)2.

[0093] Two R atoms bonded to adjacent carbon atoms. S When R is linked to each other by a linking group or single bond, the remaining R is not involved in this bond. S The alkyl group, which may be substituted, is more preferably a substituted alkyl group having 1 to 6 carbon atoms, even more preferably an unsubstituted alkyl group having 1 to 6 carbon atoms, and most preferably a methyl group in all cases. In other words, a preferred example of the group represented by formula (A20) is the group represented by formula (A20-a).

[0094] [ka] In the formula, Me represents methyl.

[0095] LS >NR and >Si(-R)2, at least one of the R's is a linking group or single bond to the A, B, C, D, E rings and R S It may be combined with at least one selected from the group consisting of L. S Examples of when >NR include groups represented by any of the following formulas, with the group represented by formula (A20-b-1) being preferred.

[0096] [ka]

[0097] In each formula, Me is methyl. In each formula, * is bonded to two or three adjacent atoms on any of the aryl, heteroaryl, or cycloalkane rings in rings A, B, C, D, and E.

[0098] In formula (4), Y is independently B, P, P=O, or P=S, with B or P=O being preferred and B being more preferred. The two Ys in the polycyclic aromatic compound of the present invention may be the same or different, but they are preferably the same.

[0099] In equation (4), each X is independently >C(-R) 2、>NR, >O, >Si(-R)2, >S, or >Se, where R in >NR is hydrogen, optionally substituted aryl, optionally substituted heteroaryl, optionally substituted alkyl, or optionally substituted cycloalkyl, and R in >C(-R)2 and >Si(-R)2 are independently hydrogen, optionally substituted aryl, optionally substituted alkyl, or optionally substituted cycloalkyl, and the two Rs in >C(-R)2 and >Si(-R)2 may be bonded to each other to form a ring, and at least one of the Rs in >NR, >C(-R)2, and >Si(-R)2 may be bonded to at least one of the A, B, C, D, or E rings by a linking group or single bond. The multiple Xs in the polycyclic aromatic compound of the present invention may be the same or different from each other.

[0100] In formula (4), R in >Si(-R)2 of X is an optionally substituted aryl, optionally substituted heteroaryl, optionally substituted alkyl, or optionally substituted cycloalkyl, and examples of substituents include the second substituents mentioned above. Examples of these aryl, heteroaryl, alkyl, or cycloalkyl groups include those listed above. Particularly preferred are aryl groups having 6 to 10 carbon atoms (e.g., phenyl, naphthyl), heteroaryl groups having 2 to 15 carbon atoms (e.g., carbazolyl), alkyl groups having 1 to 5 carbon atoms (e.g., methyl, ethyl), or cycloalkyl groups having 5 to 10 carbon atoms (preferably cyclohexyl or adamantyl).

[0101] In formula (4), R in >C(-R)2 of X is hydrogen, an optionally substituted aryl, an optionally substituted heteroaryl, an optionally substituted alkyl, or an optionally substituted cycloalkyl, and examples of substituents include the second substituents mentioned above. Examples of these aryl, heteroaryl, alkyl, or cycloalkyl groups include those mentioned above. Particularly preferred are aryl groups having 6 to 10 carbon atoms (e.g., phenyl, naphthyl), heteroaryl groups having 2 to 15 carbon atoms (e.g., carbazolyl), alkyl groups having 1 to 5 carbon atoms (e.g., methyl, ethyl), or cycloalkyl groups having 5 to 10 carbon atoms (preferably cyclohexyl or adamantyl).

[0102] As described above, the two R atoms in X, >C(-R)2 and >Si(-R)2, may be bonded to each other to form a ring. The two R atoms may be bonded by a single bond or by a linking group (collectively called a bonding group). Examples of such linking groups include -CH2-CH2-, -CHR-CHR-, -CR2-CR2-, -CH=CH-, -CR=CR-, -C≡C-, -N(-R)-, -O-, -S-, -C(-R)2-, -Si(-R)2-, or -Se-, and examples of >C(-R)2 or >Si(-R)2 that form a ring are shown below. Furthermore, the R in -CHR-CHR-, -CR2-CR2-, -CR=CR-, -N(-R)-, -C(-R)2-, and -Si(-R)2- are each independently hydrogen, aryl, heteroaryl, alkyl, alkenyl, alkynyl, or cycloalkyl, and at least one hydrogen in each R may be substituted with an alkyl or cycloalkyl. Also, two adjacent Rs may form a ring, forming a cycloalkylene, arylene, or heteroarylene. Note that each substituent listed here can be referred to as described above.

[0103] [ka]

[0104] As the bonding group, a single bond, -CR=CR- as a linking group, -N(-R)-, -O-, -S-, -C(-R)₂-, -Si(-R)₂- and -Se- are preferred; a single bond, -CR=CR- as a linking group, -N(-R)-, -O-, -S- and -C(-R)₂- are more preferred; a single bond, -CR=CR- as a linking group, -N(-R)-, -O- and -S- are still more preferred; and a single bond is most preferred.

[0105] The position where two R groups are bonded by the bonding group is not particularly limited as long as it is a bondable position, but bonding at the most adjacent position is preferred. For example, when two R groups are phenyl, it is preferred that the groups are bonded to each other at the ortho position (2-position) relative to the bonding position (1-position) of "C" or "Si" in phenyl (see the above structural formula).

[0106] For X in formula (4), at least one X is >N-R described above, and the other Xs are each independently preferably >O, >N-R or >S; more preferably, at least one X is >N-R; still more preferably, at least one X is >N-R and at least one X is >O, and the structure contains at least one each of >N-R, >O and >S. A high-efficiency or long-life device can be formed from the compound of the present invention containing >S as X.

[0107] For the aryl, heteroaryl, alkyl, and cycloalkyl elements in R of >NR in X, refer to their descriptions as first substituents above. R of >NR in X is preferably an optionally substituted aryl, an optionally substituted heteroaryl, or an optionally substituted cycloalkyl, and more preferably an optionally substituted aryl. Here, preferred aryls are phenyl, biphenylyl (especially 2-biphenylyl), and terphenylyl (especially terphenyl-2'-yl), with phenyl and biphenyl being more preferred. When the aryl is substituted, preferred substituents are methyl or tert-alkyl represented by the above formula (tR). The number of substituents on the aryl is preferably 0 to 3, and more preferably 1 to 2.

[0108] In X, the R in >NR is particularly preferably unsubstituted phenyl, phenyl with methyl groups attached to the ortho or para position, and phenyl with one or two methyl groups attached to the ortho position.

[0109] For example, the R in >NR in X may have the following structures: Having an o-phenylene structure in R of >NR prevents intermolecular stacking and suppresses concentration quenching. Having a p-phenylene structure in R of >NR imparts horizontal orientation to the molecule and improves light extraction efficiency. Having a heteroaryl or heteroarylene structure in R of >NR allows for adjustment of emission wavelength and hole or electron acceptability. In the following, dashed lines indicate the binding site with N.

[0110] [ka]

[0111] [ka]

[0112] In X, R in >NR is more preferably unsubstituted phenyl, phenyl with methyl groups attached to two meta positions (3,5-dimethylphenyl), phenyl with methyl groups attached to the ortho or para position, phenyl with methyl groups attached to one or two ortho positions, and 2-biphenylyl which may be substituted with a tert-alkyl group, with 3,5-dimethylphenyl and 2-biphenylyl which may be substituted with a tert-alkyl group being particularly preferred.

[0113] In X, the R in at least one of >NR, >Si(-R)2, and >C(-R)2 may be linked to at least one ring in the A, B, C, D, or E rings by a linking group or single bond. Preferred linking groups are -O-, -S-, or -C(-R)2-. The R in "-C(-R)2-" is hydrogen, alkyl, or cycloalkyl. Examples of alkyl or cycloalkyl groups include those listed above. Particularly preferred are alkyl groups with 1 to 5 carbon atoms (e.g., methyl, ethyl, etc.) or cycloalkyl groups with 5 to 10 carbon atoms (preferably cyclohexyl or adamantyl). This explanation also applies to the linking group "-C(-R)2-" when X in formulas (2A) and (2B) is linked to at least one ring in the A, B, C, D, or E rings.

[0114] Examples of structures in which R in at least one of >NR, >Si(-R)2, and >C(-R)2 in X is linked to at least one ring in the A, B, C, D, or E ring by a linking group or single bond include the structure represented by formula (A10) described below. More generally, other examples include compounds having a ring structure in which X is incorporated into a fused ring D', as represented by formula (1-3-1) below, and compounds having a ring structure in which X is incorporated into a fused ring A', as represented by formula (1-3-2) below. The formed fused ring D' (or fused ring A') is, for example, a carbazole ring, a phenoxazine ring, or a phenothiazine ring.

[0115] [ka]

[0116] The polycyclic aromatic compound of the present invention preferably has a structure in which at least one of the X groups linking the ring structures is >NR, where R is an optionally substituted alkyl or optionally substituted cycloalkyl group, and is linked by a linking group or single bond to an aryl or heteroaryl ring in at least one of the A, B, C, D, or E rings.

[0117] For example, the following substructure (A10) may be formed by the above-described connection. [ka]

[0118] 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 bonded to each other by linking groups or single bonds, with X bonded to one ring of the two rings at the two * positions and to the other ring at the ** position. That is, N in formula (A10) is the N of >NR when X is >NR. 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 NC bonds with a weak bond dissociation energy (BDE), but the presence of another bond forming the ring promotes the reverse reaction (recombination reaction) even when the NC bond is broken, resulting in a more stable structure. Therefore, it is expected that organic EL devices manufactured using the polycyclic aromatic compound of the present invention having such a structure will have a longer device life. When the polycyclic aromatic compound of the present invention contains the structure represented by formula (A10), its number is 1 to "number of X", and is preferably 1 or 2.

[0119] In formula (A10), R A1~R A4 Any 2 to 4 of these may be linked to each other by linking groups. A1 ~R A4 are any two (R A1 and R A4 , R A1 and R A4 Furthermore, R A1 and R A4 , R A1 and R A2 , R A3 and R A4 , R A1 and R A4 Furthermore, R A1 and R A4 It is preferable that the ) are linked to each other by a linking group or a single bond, 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.

[0120] 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).

[0121] [ka] In formula (A11), Me is methyl, and is bonded to one of the two rings to which X is bonded at the two * positions, and to the other ring at the ** position.

[0122] Examples of polycyclic aromatic compounds represented by formula (4) include the compound represented by formula (4-1) when both n are 1, and the compounds represented by formulas (4-11), (4-12), (4-13), or (4-14) when one n is 0 and the other is 1.

[0123] [ka]

[0124] In equations (4-1), (4-11), (4-12), (4-13), and (4-14), Rings A, B, C, and D are each optionally substituted aryl rings or optionally substituted heteroaryl rings, and Y is independently B, P, P=O, or P=S. Each X is independent of >C(-R) 2、 >NR, >O, >Si(-R)2, >S, or >Se, where R in >NR is an optionally substituted aryl, optionally substituted heteroaryl, optionally substituted alkyl, or optionally substituted cycloalkyl, where R in >C(-R)2 and >Si(-R)2 is hydrogen, optionally substituted aryl, optionally substituted alkyl, or optionally substituted cycloalkyl, where the two Rs in >C(-R)2 and >Si(-R)2 may be bonded to each other to form a ring, and at least one of the Rs in >NR, >C(-R)2, and >Si(-R)2 may be bonded by a linking group or single bond to a Z adjacent to any carbon atom to which the X containing the R is directly bonded. Z is independent of each other, -C(-R Z )= or -N=, and two adjacent Zs are -C(-RZ )2-, -Si(-R Z )2-, -N(-R Z )-, -O-, -S-, or -Se- may be substituted, R Z Each is independently either a hydrogen atom or a substituent, and R Z Adjacent groups of these groups bond together to form the R Z The ring to which it is bonded may form an aryl ring or a heteroaryl ring, and the formed ring may be substituted. In the structure represented by formula (4-1), formula (4-11), formula (4-12), formula (4-13), or formula (4-14), at least one selected from the group consisting of aryl rings and heteroaryl rings may be condensed with at least one cycloalkane, at least one hydrogen in the cycloalkane may be substituted, and at least one -CH2- in the cycloalkane may be substituted with -O-. At least one hydrogen atom in the structure represented by formula (4-1), formula (4-11), formula (4-12), formula (4-13), or formula (4-14) may be substituted with deuterium, cyano, or halogen.

[0125] In equations (4-1), (4-11), (4-12), (4-13), and (4-14), ring A, ring B, ring C, and ring D are synonymous with ring A, ring B, ring C, and ring D in equation (4), respectively, and their preferred ranges are the same. Y is synonymous with Y in equation (4), and their preferred ranges are the same. X is synonymous with X in equation (4), and their preferred ranges are the same.

[0126] In equations (4-1), (4-11), (4-12), (4-13), and (4-14), Z is independently -C(-R Z )= or -N=, and two adjacent Zs are -C(-R Z )2-, -Si(-R Z )2-, -N(-R Z )-, -O-, -S-, or -Se- may be used as replacements.

[0127] R Z are each independently hydrogen or a substituent. More specifically, R Z are each independently hydrogen, aryl, heteroaryl, diarylamino, diheteroarylamino, arylheteroarylamino, diarylboryl (the two aryl groups may be bonded via a single bond or a linking group), alkyl, cycloalkyl, alkoxy, aryloxy, substituted silyl, or -L-Ak, and at least one hydrogen in each of the above groups other than -L-Ak may be substituted with aryl, heteroaryl, alkyl or cycloalkyl. Also, R Z adjacent groups among may be bonded to each other to form an aryl ring or a heteroaryl ring together with the ring to which the R Z is bonded, at least one hydrogen in the formed ring may be substituted, and specific examples of the substituent include substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted diarylamino, substituted or unsubstituted diheteroarylamino, substituted or unsubstituted arylheteroarylamino, substituted or unsubstituted diarylboryl (the two aryl groups may be bonded via a single bond or a linking group), substituted or unsubstituted alkyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted alkoxy, substituted or unsubstituted aryloxy, substituted silyl, or -L-Ak. Examples of the substituent when referred to as "substituted or unsubstituted" or "substituted" include aryl, heteroaryl, alkyl and cycloalkyl.

[0128] Examples of the structure in which two adjacent Z are replaced with -C(-R Z )2-, -Si(-R Z )2-, -N(-R Z )-, -O-, or -S- include a cyclopentadiene ring, a pyrrole ring, a furan ring, a thiophene ring, a thiazole ring, an oxazole ring, and the like. Provided that two adjacent Z are -C(-R Z )2-, -Si(-R Z )2-, -N(-R Zpreferably not replaced by -, -O-, or -S-. In this case, Z at the o (ortho) position or p (para) position relative to Y is -C(-R Z )= is preferable. Further, in a ring (monocyclic ring) containing Z that is -N=, it is preferable that one or two among the plurality of Z are -N=, and when two are -N=, it is preferable that the two -N= are not adjacent to each other. When the 6-membered ring is a ring containing Z that is -N=, a pyridine ring, pyrazine ring, pyrimidine ring, pyridazine ring, or 1,3,5-triazine ring is preferable, and a pyridine ring, pyrazine ring, or pyrimidine ring is more preferable. The number of rings (monocyclic rings) containing Z that is -N= is preferably 0 to 4, more preferably 0 to 3, still more preferably 0 to 2, and particularly preferably 0 to 1. -C(-R at the ortho position or para position relative to the carbon to which X or >N- is bonded Z )= is preferably -N=.

[0129] In one embodiment, all Z are -C(-R Z )=, that is, it is also preferable that each ring is a benzene ring which may have a substituent.

[0130] In each of formula (4-1), formula (4-11), formula (4-12), formula (4-13) and formula (4-14), Z is -C(-R Z ) R when = Z are each independently hydrogen, aryl having 6 to 30 carbon atoms, heteroaryl having 2 to 30 carbon atoms, diarylamino (wherein aryl is aryl having 6 to 12 carbon atoms), diarylboryl (wherein aryl is aryl having 6 to 12 carbon atoms, and the two aryl groups may be bonded via a single bond or a linking group), alkyl having 1 to 24 carbon atoms, cycloalkyl having 3 to 24 carbon atoms, triarylsilyl (wherein aryl is aryl having 6 to 12 carbon atoms), or trialkylsilyl (wherein alkyl is alkyl having 1 to 6 carbon atoms), and these may have a substituent, provided that adjacent R ZThe elements may be bonded together with the a, b, or c rings to form an aryl ring having 9 to 16 carbon atoms or a heteroaryl ring having 6 to 15 carbon atoms, and at least one hydrogen atom in the formed ring may be substituted with an aryl element having 6 to 10 carbon atoms, an alkyl element having 1 to 12 carbon atoms, a cycloalkyl element having 3 to 16 carbon atoms, a triarylsilyl element (where the aryl element is an aryl element having 6 to 12 carbon atoms), or a trialkylsilyl element (where the alkyl element is an alkyl element having 1 to 5 carbon atoms). R Z Each of these is more preferably independently hydrogen, a C6-C16 aryl, a C2-C20 heteroaryl, a diarylamino (where the aryl is a C6-C10 aryl), a C1-C12 alkyl, or a C3-C16 cycloalkyl (each of these may have substituents), and even more preferably independently hydrogen, a C6-C16 aryl, a diarylamino (where the aryl is a C6-C10 aryl), a C1-C12 alkyl, or a C3-C16 cycloalkyl (each of these may have substituents).

[0131] R Z For further details and preferred ranges, refer to the descriptions of the first and second substituents above. In particular, R Z Preferred members are substituted or unsubstituted aryls, substituted or unsubstituted heteroaryls, substituted or unsubstituted diarylaminos, or substituted or unsubstituted alkyls, with alkyls that may be substituted with alkyls, diarylaminos that may be substituted with alkyls, or alkyls.

[0132] In equations (4-1), (4-11), (4-12), (4-13), and (4-14), R Z Preferably, 0 to 3 of the atoms are substituents, and the rest are hydrogen atoms. In particular, the substituent R Z It is preferable that R is at the para position of Y. Z It is also preferable that the substituent R is located at one or two meta positions of Y. ZWhen R is in the para position of Y, it is preferable because selective introduction of boron (Y) is possible during synthesis, and in this case, Z More specifically, R is preferably an alkyl or diarylamino. Z It is preferable that the diarylamino is located at the para position of Y from the viewpoint of obtaining high TADF and high oscillator strength. Z Having an aryl or heteroaryl group is preferable from the viewpoint of obtaining high oscillator strength. Z From the viewpoint of preventing an increase in sublimation temperature, it is preferable that the molecule contains alkyl, cycloalkyl, aryl with alkyl as a substituent, heteroaryl with alkyl as a substituent, or diarylamino with alkyl as a substituent.

[0133] R in each ring in equations (4-1), (4-11), (4-12), (4-13), and (4-14) Z Preferably, for each ring structure (aryl ring or heteroaryl ring in rings A, B, C, D, and E), 0 to 1 substituent other than hydrogen and the rest are hydrogen.

[0134] In formulas (4-1), (4-11), (4-12), (4-13), and (4-14), R bonded to adjacent C (carbon atoms) Z These elements may bond together to form an aryl ring or a heteroaryl ring with the ring containing the carbon atom.

[0135] Examples of ring structures containing Z in equations (4-1), (4-11), (4-12), (4-13), and (4-14) are shown below as examples of structures containing four Zs and bonded to X and Y. In the following equations, R is R Z This is synonymous, but does not mean that R units are combined with each other. Also, n is an integer from 0 to 4, and R N and R cis 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, or a cycloalkyl which may be substituted with alkyl, and two R c These elements may bond to each other to form a ring. For information on the rings that are formed, refer to the later explanation regarding the cases where two R elements in X, >C(-R)2 and >Si(-R)2, bond to each other to form a ring.

[0136] [ka]

[0137] [ka]

[0138] [ka]

[0139] The polycyclic aromatic compound represented by formula (4-1) preferably contains X which is >NR. In this case, R in >NR is preferably an unsubstituted cycloalkyl or an optionally substituted aryl, and preferably an unsubstituted cyclohexyl, optionally substituted phenyl, or optionally substituted biphenylyl. It is also preferable that R in >NR has a structure in which it is bonded by a linking group or single bond to a Z adjacent to any carbon atom to which N is directly bonded. Preferred linking groups are -O-, -S-, or -C(-R)2-. In "-C(-R)2-", R is hydrogen, alkyl, or cycloalkyl. Examples of alkyl or cycloalkyl groups include those mentioned above. Particularly preferred are alkyl groups with 1 to 5 carbon atoms (e.g., methyl, ethyl, etc.) or cycloalkyl groups with 5 to 10 carbon atoms (preferably cyclohexyl or adamantyl).

[0140] The C ring in formula (4-11) and the D ring in formula (4-13) are preferably fused heteroaryl rings (which may have substituents), and more preferably they are optionally substituted indole rings, optionally substituted benzimidazole rings, optionally substituted dibenzazepine rings, optionally substituted iminodibenzyl rings, optionally substituted tribenzoazepine rings, or optionally substituted carbazole rings. The above C and D rings are preferably bonded to Y at the carbon atoms constituting the heteroaryl ring and to the carbon atoms constituting the ring containing Z at the nitrogen atom. Furthermore, it is preferable that a 6-membered ring containing this nitrogen atom and Y is formed. For example, when bonded to Y in an indole ring, benzimidazole ring, dibenzazepine ring, iminodibenzyl ring, tribenzoazepine ring, or carbazole ring, it is preferable that Y is bonded at the * position and Z is bonded at the # position, respectively. Note that each ring may have substituents.

[0141] [ka]

[0142] Furthermore, compounds represented by formulas (4-11) or (4-13) that have these rings as a C or D ring are also compounds represented by formula (4-1) in which the R in >NR, which is a predetermined X in formula (4-1), is bonded by a linking group or single bond to a Z adjacent to any carbon atom directly bonded to N. For example, the dibenzazepine ring can be considered as a structure in which the R in >NR is phenyl bonded to a carbon atom at Z by an alkenylene, the iminodibenzyl ring can be considered as a structure in which the R in >NR is phenyl bonded to a carbon atom at Z by an alkylene, the tribenzoazepine ring can be considered as a structure in which the R in >NR is biphenyl bonded to a carbon atom at Z by a single bond, and the carbazole ring can be considered as a structure in which the R in >NR is phenyl bonded to a carbon atom at Z by a single bond.

[0143] The B ring in formula (4-12) and the A ring in formula (4-14) are preferably fused heteroaryl rings (which may have substituents), and more preferably they are optionally substituted indole rings, optionally substituted benzimidazole rings, optionally substituted dibenzazepine rings, optionally substituted tribenzoazepine rings, or optionally substituted iminodibenzyl rings. The A and B rings are preferably bonded to Y at the carbon atoms constituting the heteroaryl ring and to the carbon atoms constituting the ring containing Z at the nitrogen atom. It is also preferable that a six-membered ring containing this nitrogen atom and Y is formed. For example, when bonded to Y in an indole ring, benzimidazole ring, dibenzazepine ring, iminodibenzyl ring, tribenzoazepine ring, or carbazole ring, it is preferable that the bond is to the carbon atoms constituting the ring containing Y at the position of *, X at the position of **, and Z at the position of #, respectively. Each ring may have substituents.

[0144] [ka]

[0145] Furthermore, compounds represented by formulas (4-12) or (4-14) that have these rings as the B ring or A ring are also compounds represented by formula (4-1) in which the R in >NR, which is a predetermined X in formula (4-1), is bonded by a linking group or single bond to a Z adjacent to any carbon atom that is directly bonded to N.

[0146] At least one selected from the group consisting of aryl rings and heteroaryl rings in the compound represented by formula (4) may be condensed with at least one cycloalkane, at least one hydrogen in the cycloalkane may be substituted, and at least one -CH2- in the cycloalkane may be substituted with -O-. This explanation also applies to the compounds represented by formulas (4-1), (4-11), (4-12), (4-13), and (4-14).

[0147] 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.

[0148] 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[2.2.1]heptane, bicyclo[2.2.2]octane, adamantane, diamantane, decahydronaphthalene, and decahydroazulene, as well as alkyl (especially methyl), halogen (especially fluorine), and deuterium-substituted derivatives of these compounds having 1 to 5 carbon atoms.

[0149] Among these, a structure in which at least one hydrogen is substituted at the α-position carbon of the cycloalkane (in a cycloalkyl condensed to an aryl ring or heteroaryl ring, the carbon adjacent to the carbon at the condensation site) is preferred, a structure in which two hydrogens are substituted at the α-position carbon is more preferred, and a structure in which a total of four hydrogens are substituted at two α-position carbons is even more preferred. Examples of substituents include alkyl (especially methyl) substituted compounds having 1 to 5 carbon atoms, halogen (especially fluorine) substituted compounds, and deuterium substituted compounds. In particular, a structure in which a substructure represented by the following formula (B10) is bonded to an adjacent carbon atom in an aryl ring or heteroaryl ring is preferred.

[0150] [ka] In formula (B10), Me represents a methyl group, and * indicates the bond position.

[0151] In the chemical structure of the polycyclic aromatic compound represented by formula (4), all or part of the hydrogen atoms may be substituted with deuterium, cyanopropyl alcohol, or halogen. For example, in the polycyclic aromatic compound represented by formula (4), the aryl or heteroaryl rings in the A, B, C, D, or E rings, the substituents on these rings, and the hydrogen atoms in R (=alkyl, cycloalkyl, aryl) when X is >NR, >C(-R)2, or >Si(-R)2 may be substituted with deuterium, cyanopropyl alcohol, or halogen. Among these, embodiments in which all or part of the hydrogen atoms in the aryl or heteroaryl rings are substituted with deuterium, cyanopropyl alcohol, or halogen are particularly noteworthy. The halogen is fluorine, chlorine, bromine, or iodine, preferably fluorine, chlorine, or bromine, more preferably fluorine or chlorine, and even more preferably fluorine. Furthermore, from the viewpoint of durability, it is also preferable that all or part of the hydrogen atoms in the chemical structure of the polycyclic aromatic compound represented by formula (4) are deuterated. This explanation also applies to the compounds represented by formulas (4-1), (4-11), (4-12), (4-13), and (4-14).

[0152] Among the polycyclic aromatic compounds represented by formulas (4-1), (4-11), (4-12), (4-13), or (4-14), the polycyclic aromatic compound represented by formula (4-1) is preferred. Furthermore, as the polycyclic aromatic compound represented by formula (4-1), the compound represented by formula (4-1-A) is preferred.

[0153] [ka]

[0154] In the formula, Xd is >O, >NR Xd , or >S, R Xd R is an optionally substituted aryl or optionally substituted heteroaryl, Xd Xd containing any carbon atom to which it is directly bonded may be bonded by a linking group or a single bond to a carbon adjacent to it, R dnR is an optionally substituted aryl or optionally substituted heteroaryl, d Each of these is independently hydrogen, an unsubstituted alkyl group, an optionally alkyl-substituted aryl group, an optionally alkyl-substituted heteroaryl group, or an optionally alkyl-substituted diarylamino group.

[0155] R Xd It is preferable that R is an aryl which may be substituted with an alkyl, aryl, diarylamino, or arylheteroarylamino, or a heteroaryl which may be substituted with an alkyl, aryl, diarylamino, or arylheteroarylamino. dn Preferably, the compound is an aryl or heteroaryl which may be substituted with an alkyl, aryl, diarylamino, or arylheteroarylamino.

[0156] Examples of polycyclic aromatic compounds represented by formulas (4-1), (4-11), (4-12), (4-13), or (4-14) include those represented by any of the following formulas. In each of the following formulas, 0 to 2 hydrogen atoms in each benzene ring may be substituted with the substituents (first substituents) described above.

[0157] [ka]

[0158] [ka]

[0159] [ka]

[0160] [ka]

[0161] More specific examples of polycyclic aromatic compounds represented by formulas (4-1), (4-11), (4-12), (4-13), or (4-14) include the compounds represented by the following structural formulas. In the structural formulas below, "Me" represents methyl and "tBu" represents t-butyl.

[0162] [ka]

[0163] [ka]

[0164] [ka]

[0165] [ka]

[0166] [ka]

[0167] [ka]

[0168] [ka]

[0169] [ka]

[0170] [ka]

[0171]

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[0172]

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[0173]

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[0174]

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[0175]

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[0176]

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[0177]

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[0178]

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[0179]

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[0180]

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[0181] [ka]

[0182] [ka]

[0183] [ka]

[0184] [ka]

[0185] [ka]

[0186] [ka]

[0187] 1-2. Reactive compounds, polymer compounds, polymer crosslinks, pendant-type polymer compounds, pendant-type polymer crosslinks The polycyclic aromatic compound represented by formula (4) can be used as a material for organic devices, such as a material for organic field-light-emitting devices, a material for organic field-effect transistors, or a material for organic thin-film solar cells, whether as a polymer compound obtained by polymerizing a reactive compound substituted with a reactive substituent (the monomer for obtaining this polymer compound has a polymerizable substituent), or as a crosslinked polymer obtained by further crosslinking the polymer compound (the polymer compound for obtaining this crosslinked polymer has a crosslinkable substituent), or as a pendant-type polymer compound obtained by reacting a main-chain polymer with the reactive compound (the reactive compound for obtaining this pendant-type polymer compound has a reactive substituent), or as a crosslinked pendant-type polymer obtained by further crosslinking the pendant-type polymer compound (the pendant-type polymer compound for obtaining this crosslinked polymer compound has a crosslinkable substituent).

[0188] In this specification, "polymer compound" refers to a compound having a molecular weight distribution and a number-average molecular weight of 1 × 10⁻¹⁶ on a polystyrene basis. 3 ~1 × 10 8 This refers to polymers with a number of units (1 × 10³ to 1 × 10⁸). The number-average molecular weight (Mn) of a polymer compound in terms of polystyrene can be determined by size exclusion chromatography (SEC) using tetrahydrofuran as the mobile phase. Specifically, the polymer compound to be measured is dissolved in tetrahydrofuran at a concentration of approximately 0.05% by mass, and 10 μL is injected into the SEC. The mobile phase flow rate is 1.0 mL / min, and a PLgelMIXED_B column (manufactured by Polymer Laboratories) is used. A UV_VIS detector (manufactured by Toso Corporation, product name: UV-8320GPC) can be used as the detector. The polymer compounds of the present invention have a number-average molecular weight of 2000 to 1 × 10 8 Preferably, 5000~1×10 8 It is preferable that it be so.

[0189] The reactive substituents described above (including the polymerizable substituents, the crosslinkable substituents, and the reactive substituents for obtaining a pendant-type polymer, and hereinafter simply referred to as "reactive substituents") are substituents that can increase the molecular weight of the polycyclic aromatic compound, substituents that can further crosslink the polymer compound obtained in this way, and substituents that can undergo a pendant reaction with the main chain polymer, but are not particularly limited as long as they are capable of this. Examples include alkenyl, alkynyl, and cycloalkyl unsaturated compounds (e.g., cyclobutenyl), groups in which at least one -CH2- in a cycloalkyl group is substituted with -O- (e.g., epoxy), and unsaturated compounds of condensed cycloalkanes (e.g., condensed cyclobutene), and substituents with the following structures are preferred. * in each structural formula indicates the bond position.

[0190] [ka]

[0191] L is independently a single bond, -O-, -S-, >C=O, -OC(=O)-, a C1-C12 alkylene, a C1-C12 oxyalkylene, and a C1-C12 polyoxyalkylene. Among the above substituents, groups represented by formula (XLS-1), (XLS-2), (XLS-3), (XLS-9), (XLS-10), or (XLS-17) are preferred, and groups represented by formula (XLS-1), (XLS-3), or (XLS-17) are more preferred.

[0192] Details of the applications of such polymer compounds, polymer crosslinks, pendant-type polymer compounds, and pendant-type polymer crosslinks (hereinafter also simply referred to as "polymer compounds and polymer crosslinks") will be described later.

[0193] 2. Method for producing polycyclic aromatic compounds Polycyclic aromatic compounds represented by formula (4) can basically be produced by first bonding the A, B, C, D, and E rings with a bonding group (a group containing X or N) to produce an intermediate (first reaction), and then bonding the A, B, C, D, and E rings with a bonding group (a group containing Y) to produce the final product (second reaction). In the first reaction, for example, if it is an etherification reaction, general reactions such as nucleophilic substitution reactions and Ullmann reactions can be used, and if it is an amination reaction, general reactions such as the Buchwald-Hartwig reaction can be used. In the second reaction, a tandem hetero-Friedel-Crafts reaction (a series of aromatic electrophilic substitution reactions, the same applies below) can be used. For these production methods, refer to the methods described in prior literature such as International Publication No. 2015 / 102118.

[0194] 3. Organic devices The polycyclic aromatic compounds according to the present invention can be used as materials for organic devices. Examples of organic devices include organic field-light-emitting devices, organic field-effect transistors, and organic thin-film solar cells.

[0195] 3-1. Organic electroluminescent element The organic EL element according to this embodiment will be described in detail below with reference to the drawings. Figure 1 is a schematic cross-sectional view showing the organic EL element according to this embodiment.

[0196] 3-1-1. Structure of an organic electroluminescent device 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.

[0197] 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.

[0198] 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.

[0199] 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".

[0200] 3-1-2. 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. The substrate 101 is formed in the form of a plate, film, or sheet depending on the purpose, and can be made of glass, metal, metal foil, plastic film, or plastic sheet, for example. Among these, glass plates and transparent synthetic resin plates such as polyester, polymethacrylate, polycarbonate, or polysulfone are preferred. If a glass substrate is used, soda-lime glass or alkali-free glass can be used, and the thickness only needs to be sufficient to maintain mechanical strength, for example, 0.2 mm or more is sufficient. The upper limit of the thickness is, for example, 2 mm or less, preferably 1 mm or less. Regarding the glass material, alkali-free glass is preferred because it is better to have fewer ions eluted from the glass, but soda-lime glass with a barrier coating such as SiO2 is also commercially available and can be used. Furthermore, to enhance the gas barrier properties, the substrate 101 may be provided with a gas barrier film, such as a dense silicon oxide film, on at least one side. 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.

[0201] 3-1-3. Anode in an Organic Electroluminescent Device The anode 102 plays the role of injecting holes into the light-emitting layer 105. If a hole injection layer 103 and / or a hole transport layer 104 are provided between the anode 102 and the light-emitting layer 105, holes will be injected into the light-emitting layer 105 via these layers.

[0202] 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.

[0203] The resistance of the transparent electrode is not limited as long as it can supply sufficient current for the light-emitting element to emit light, but from the viewpoint of the power consumption of the light-emitting element, low resistance is desirable. For example, an ITO substrate with a resistance of 300 Ω / □ or less will function as an element electrode, but since substrates of about 10 Ω / □ are now available, it is particularly desirable to use a low-resistance product of, for example, 100 to 5 Ω / □, preferably 50 to 5 Ω / □. The thickness of the ITO can be arbitrarily selected according to the resistance value, but it is usually used between 50 and 300 nm.

[0204] 3-1-4. 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 and mixing one or more types of hole injection / transport materials, or by a mixture of hole injection / transport materials and a polymer binder. Alternatively, an inorganic salt such as iron(III) chloride may be added to the hole injection / transport material to form a layer.

[0205] For hole injection and transport 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 use a material that has a low ionization potential, high hole mobility, excellent stability, and is less likely to generate trapping impurities during manufacturing and use.

[0206] 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'-Tetra[1,1'-biphenyl]-4-yl)-[1,1'-biphenyl]-4,4'-diamine, 4,4',4”-tris(3-methylphenyl(phenyl)amino)triphenylamine, N-([1,1'-biphenyl]-4-yl)-9,9-dimethyl-N-(4-(9-phenyl-9H-carbazole-3-yl)phenyl)-9H-fluoren-2-amine, N,N-bis(4-(dibenzo[b,d]furan-4-yl)phenyl)-[1,1':4',1”-terphenyl]- Examples include triphenylamine derivatives such as 4-amines, starburstamine derivatives, stilbene derivatives, phthalocyanine derivatives (metal-free, copper phthalocyanine, etc.), pyrazoline derivatives, hydrazone compounds, benzofuran derivatives and thiophene derivatives, oxadiazole derivatives, quinoxaline derivatives (e.g., 1,4,5,8,9,12-hexaazatriphenylene-2,3,6,7,10,11-hexacarbonitrine, etc.), heterocyclic compounds such as porphyrin derivatives, and polysilanes. Among polymer systems, polycarbonates and styrene derivatives having the above monomers in their side chains, polyvinylcarbazoles, and polysilanes are preferred, but the compounds are not particularly limited as long as they can form a thin film necessary for the fabrication of a light-emitting device, allow holes to be injected from the anode, and transport holes.

[0207] Furthermore, the conductivity of organic semiconductors is known to be strongly affected by doping. 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 electron transfer processes in electron-donating base materials (hole transport materials). 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).

[0208] The hole injection layer material and hole transport layer material described above can also be used as a hole layer material as a polymer compound obtained by polymerizing a reactive compound in which a reactive substituent is substituted as a monomer, or as a polymer crosslink thereof, or as a pendant-type polymer compound obtained by reacting a main-chain polymer with the reactive compound, or as a pendant-type polymer crosslink thereof. In this case, the explanation for the polycyclic aromatic compound represented by formula (4) can be referenced as the reactive substituent. Details of the applications of such polymer compounds and polymer crosslinks will be described later.

[0209] 3-1-5. Light-emitting layer in an organic electroluminescent device The light-emitting layer 105 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. It is preferable that the compound can form a stable thin film shape and exhibits strong luminescence (fluorescence) efficiency in the solid state. The light-emitting layer may consist of a single layer or multiple layers, each formed from a light-emitting layer material (host material, dopant material). The host material and dopant material may each be one type or a combination of multiple types. For example, an emitting dopant and an assisting dopant may be used as the 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, but it may also be mixed with the host material beforehand and then deposited simultaneously. Furthermore, the light-emitting layer can also be formed by a wet film deposition method using a light-emitting layer-forming composition prepared by dissolving materials in an organic solvent.

[0210] The polycyclic aromatic compounds of the present invention can be preferably used as materials for forming the light-emitting layer of an organic electroluminescent device. The polycyclic aromatic compounds of the present invention are more preferably used as an emitting dopant or an assisting dopant in the light-emitting layer, and even more preferably as an emitting dopant.

[0211] The polycyclic aromatic compound represented by formula (4) may be used as a "thermally activated delayed phosphor" and as an emitting dopant for an organic EL device (hereinafter sometimes referred to as a "TADF device") that exhibits thermally activated delayed fluorescence (TADF). In a "thermally activated delayed phosphor," by reducing the energy difference between the lowest excited singlet state and the lowest excited triplet state, the reverse intersystem cross-transition from the lowest excited triplet state to the lowest excited singlet state, which normally has a low transition probability, is generated with high efficiency, and emission from the singlet state (thermally activated delayed fluorescence, TADF) is produced. In normal fluorescence emission, 75% of the triplet excitons generated by electric excitation pass through the thermal deactivation pathway and cannot be extracted as fluorescence. On the other hand, in TADF, all excitons can be used for fluorescence emission, enabling the realization of a highly efficient organic EL device.

[0212] The polycyclic aromatic compound represented by formula (4) can be used as an emitting dopant for a "TADF element," an emitting dopant for a TADF element using two types of hosts, an emitting dopant for an organic electroluminescent element (TADF-assisted fluorescent element, TAF element) using another thermally activated delayed phosphor as an assisting dopant, and an emitting dopant for an organic electroluminescent element (phosphor-sensitized fluorescent element, PSF element) using a phosphorescent material as an assisting dopant. From the viewpoint that fewer materials used in the element make it easier to manufacture, the emitting dopant for the TADF element and the emitting dopant for a TADF element using two types of hosts are preferred, and the emitting dopant for the TADF element is more preferred. From the viewpoint of efficiency, the emitting dopant for the TAF element and the emitting dopant for the phosphorescent-assisted element are preferred, and the emitting dopant for the TAF element is more preferred.

[0213] Generally, a faster delayed fluorescence (TADF) indicates superior TADF properties. Specifically, when a light-emitting material with a delayed fluorescence lifetime of 20 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. Also, generally, 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 is preferably 0.20 eV or less, and more preferably 0.15 eV or less.

[0214] The light-emitting layer containing the polycyclic aromatic compound of the present invention may also contain a host compound. Here, the host compound may be one type or two or more types. Furthermore, the luminescent layer may consist of a single layer or multiple layers. The host compound, the emitting dopant material, and the assisting dopant material may be contained within the same layer, or at least one component may be contained in multiple layers. The host compound and dopant material (emitter dopant or assisting dopant) contained in the luminescent layer may be one type each, or a combination of multiple types. The assisting dopant and emitting dopant may be entirely or partially contained within the host compound matrix.

[0215] The amount of host material used varies depending on the type of host material and should be determined according to the characteristics of that host material. The guideline for the amount of host material used is preferably 50 to 99.999% by mass of the total material for the light-emitting layer, more preferably 80 to 99.95% by mass, and even more preferably 90 to 99.9% by mass.

[0216] The amount of dopant material used varies depending on the type of dopant material and should be determined according to the characteristics of that dopant material. A guideline for the amount of dopant used is preferably 0.001 to 50% by mass of the total material for the light-emitting layer, 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.

[0217] On the other hand, in organic electroluminescent devices using TADF material as a dopant material, a lower concentration of dopant material is preferable in that it can prevent concentration quenching, but a higher concentration of dopant material is preferable in terms of the efficiency of the thermally activated delayed fluorescence mechanism. Furthermore, in organic electroluminescent devices using TADF material as an assisting dopant, from the viewpoint of the efficiency of the thermally activated delayed fluorescence mechanism of the assisting dopant, it is preferable that the amount of emitting dopant used is lower than the amount of assisting dopant used.

[0218] When assisting dopant materials are used, the approximate amounts of host material, assisting dopant, and emitting dopant used are 40-99% by mass, 59-1% by mass, and 20-0.001% by mass, respectively, of the total 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. When assisting dopant materials are used, they may form an exciplex with the host material or emitting dopant material.

[0219] 3-1-5-1. Host Compounds The lowest excited triplet energy level of the host material (E T1The T1 energy (sometimes referred to as "T1 energy") is preferably higher than the T1 energy of the dopant or assisting dopant having the highest T1 energy in the light-emitting layer, from the viewpoint of promoting rather than inhibiting the generation of TADF in the light-emitting layer. Specifically, the T1 energy of the host is preferably 0.01 eV or higher, more preferably 0.03 eV or higher, and even more preferably 0.1 eV or higher. As the host material, a high T1 compound having a T1 energy at least 0.01 eV higher than the T1 energy of the polycyclic aromatic compound represented by formula (4) is preferred. It is also preferable that the high T1 compound be contained in an organic layer adjacent to the light-emitting layer. Alternatively, a TADF-active compound may be used as the host material.

[0220] The host material may consist of one type or two or more types in the light-emitting layer. When two or more types are included, it is preferable that the host material includes a hole-transporting host material and an electron-transporting host material that satisfy the following relationship.

[0221] The HOMO (Highest Occupied Molecular Orbital) of hole-transporting host materials (HH) is shallower than that of electron-transporting host materials (EH). The Lowest Unoccupied Molecular Orbital (LUMO) of electron-transporting host materials (EH) is deeper than that of hole-transporting host materials (HH).

[0222] As the host material (high T1 compound), a compound having at least one substructure selected from substructure group A, or at least two substructures selected from substructure group A and substructure group B, and further having at least one substructure selected from substructure group C as a linking group or substituent, is preferred. In each of the following structures, at least one * is bonded to a substructure other than hydrogen, and the other * is bonded to hydrogen. As can be seen from the following structural formulas, the carbon-carbon bonds linking the benzene rings and the bonds linking the substructures in each substructure are at the orthogonal or metagonal position. In this case, high T1 and high charge mobility are obtained. From the viewpoint of high T1, bonding at the orthogonal position is preferred, and from the viewpoint of high charge mobility, bonding at the metagonal position is preferred.

[0223] [ka]

[0224] [ka]

[0225] [ka]

[0226] [ka]

[0227] Substructure group A is preferably substructure group Aa, substructure group B is preferably substructure group Bb, and substructure group C is preferably substructure group Cc. [ka]

[0228] Examples of host materials include compounds represented by the following formula (H1), compounds represented by the following formula (H3), compounds containing the structure represented by the following formula (H4), compounds represented by the following formula (H5), and compounds represented by the following formulas (H6) and (H8). [ka]

[0229] 3-1-5-1-1. Compounds represented by formula (H1) [ka]

[0230] In formula (H1), L 1 The carbon atoms are arylenes with 6 to 24 carbon atoms or heteroarylenes with 5 to 23 carbon atoms, with arylenes with 6 to 16 carbon atoms and heteroarylenes with 5 to 15 carbon atoms being preferred, arylenes with 6 to 12 carbon atoms and / or heteroarylenes with 5 to 11 carbon atoms being more preferred, and arylenes with 6 to 10 carbon atoms or heteroarylenes with 5 to 9 carbon atoms being particularly preferred. Specifically, examples include divalent or trivalent groups such as benzene rings, biphenyl rings, terphenyl rings, fluorene rings, spirofluorene rings, phenalene rings, triphenylene rings, pyridine rings, pyrimidine rings, triazine rings, biphenylpyridine rings, biphenylpyrimidine rings, and biphenyltriazine rings. At least one hydrogen atom in the compound represented by formula (H1) may be substituted with an alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 3 to 14 carbon atoms, a cyano group, a halogen group, or a deuterium group.

[0231] [ka]

[0232] 3-1-5-1-2. Compounds represented by formula (H3) [ka]

[0233] In equation (H3), Each MU is an independent divalent aromatic group, each EC is an independent monovalent aromatic group, and k is an integer between 2 and 50000.

[0234] More specifically, MU is independently allylene, heteroarylene, dialylenearylamino, dialylenearylboryl, oxavorin-diyl, and azavorin-diyl. Each EC is independently hydrogen, aryl, heteroaryl, diarylamino, diheteroarylamino, arylheteroarylamino, or aryloxy. At least one hydrogen in MU and EC may further be substituted with aryl, heteroaryl, diarylamino, alkyl, and cycloalkyl groups. k is an integer between 2 and 50000. k is preferably an integer between 20 and 50000, and more preferably an integer between 100 and 50000.

[0235] At least one hydrogen atom in MU and EC in formula (H3) may be substituted with an alkyl group having 1 to 24 carbon atoms, a cycloalkyl group having 3 to 24 carbon atoms, a halogen, or deuterium. Furthermore, any -CH2- in the alkyl group may be substituted with -O- or -Si(CH3)2-. Any -CH2- in the alkyl group, except for the -CH2- directly connected to EC in formula (H3), may be substituted with an arylene group having 6 to 24 carbon atoms. Any hydrogen atom in the alkyl group may be substituted with fluorine.

[0236] Examples of MU include divalent derivatives of the following structures (for example, a divalent group represented by removing any two hydrogen atoms from any of the following compounds, a divalent group composed of two or more combinations of divalent groups represented by removing any two hydrogen atoms from any of the following compounds, a divalent group in which at least one hydrogen atom in those groups is substituted with an alkyl group, etc.).

[0237] [ka]

[0238] More specifically, divalent groups having one of the following structures are included. In these, MU bonds with another MU or EC at *.

[0239] [ka]

[0240] [ka]

[0241] [ka]

[0242] [ka]

[0243] [ka]

[0244] [ka]

[0245] [ka]

[0246] Furthermore, examples of EC include the group represented by the following formula. In these, EC bonds with MU at *.

[0247] [ka]

[0248] [ka]

[0249] From the viewpoint of solubility and coating film formation properties, the compound represented by formula (H3) preferably has 10 to 100% of the total number of MU (k) in the molecule being alkyl groups with 1 to 24 carbon atoms, more preferably has 30 to 100% of the total number of MU (k) in the molecule being alkyl groups with 1 to 18 carbon atoms (branched alkyl groups with 3 to 18 carbon atoms), and even more preferably has 50 to 100% of the total number of MU (k) in the molecule being alkyl groups with 1 to 12 carbon atoms (branched alkyl groups with 3 to 12 carbon atoms). On the other hand, from the viewpoint of in-plane orientation and charge transport, it is preferable that 10 to 100% of the total number of MU (k) in the molecule be alkyl groups with 7 to 24 carbon atoms, and more preferably has 30 to 100% of the total number of MU (k) in the molecule being alkyl groups with 7 to 24 carbon atoms (branched alkyl groups with 7 to 24 carbon atoms).

[0250] 3-1-5-1-3. Compounds containing the structure represented by formula (H4) A compound containing the structure represented by formula (H4) contains multiple structures represented by formula (H4), preferably 1 to 5, more preferably 1 to 3, even more preferably 1 to 2, and most preferably 1. If multiple structures are present, they are directly linked to each other by single bonds or by specific linking groups.

[0251] [ka]

[0252] In formula (H4), G is either "=C(-H)-" or "=N-", and the H in "=C(-H)-" may be substituted with a substituent or a structure represented by formula (H4).

[0253] Compounds containing the structure represented by formula (H4) can be, for example, those described in International Publication No. 2012 / 153780 and International Publication No. 2013 / 038650, and can be produced according to the methods described in the aforementioned documents.

[0254] Examples of substituents where the H in G "=C(-H)-" is substituted include aryl, heteroaryl, substituted silyl, substituted phosphine oxide, and substituted carboxyl groups.

[0255] Specific examples of the substituent "aryl" include phenyl, tolyl, xylyl, triphenylenyl, fluorenyl, 9,9-dimethylfluorenyl, benzofluorenyl, dibenzofluorenyl, biphenylyl, terphenylyl, quaterphenylyl, and the like, with phenyl, biphenylyl, terphenylyl, and fluorenyl being preferred. Examples of aryls having substituents include tolyl, xylyl, and 9,9-dimethylfluorenyl. As the specific examples show, aryls include both condensed and uncondensed aryls.

[0256] Specific examples of the substituent "heteroaryl" include pyrrolyl, pyrazolyl, pyrazinyl, pyrimidinyl, pyridadinyl, pyridyl, triazinyl, indolyl, isoindolyl, imidazolyl, benzimidazolyl, indazolyl, imidazo[1,2-a]pyridinyl, furyl, benzofuranil, isobenzofuranil, dibenzofuranil, azadibenzofuranil, thienyl, benzothienyl, dibenzothienyl, azadibenzothienyl, quinolyl, isoquinolyl, quinoxalinyl, quinazolinyl, na Examples include phthalidine, carbazolyl, azacarbazol, phenanthidinyl, acridinyl, phenazinyl, phenothiazinyl, phenoxazinyl, oxazolyl, oxadiazolyl, flazanil, benzoxazolyl, thiazolyl, thiadiazolyl, benzothiazolyl, triazolyl, tetrazolyl, and the like. Preferably, examples include dibenzofuranil, dibenzothienyl, carbazolyl, pyridyl, pyrimidinyl, triazinyl, azadibenzofuranil, and azadibenzothienyl. Dibenzofuranil, dibenzothienyl, azadibenzofuranil, or azadibenzothienyl are even more preferred.

[0257] The substituent "substituted silyl" is also preferably a group selected from the group consisting of substituted or unsubstituted trialkylsilyls, substituted or unsubstituted arylalkylsilyls, and substituted or unsubstituted triarylsilyls.

[0258] Specific examples of substituted or unsubstituted trialkylsilyls include trimethylsilyl and triethylsilyl. Specific examples of substituted or unsubstituted arylalkylsilyls include diphenylmethylsilyl, ditolylmethylsilyl, and phenyldimethylsilyl. Specific examples of substituted or unsubstituted triarylsilyls include triphenylsilyl and tritolylsilyl.

[0259] The substituent, the "substituted phosphine oxide group," may preferably be a substituted or unsubstituted diarylphosphine oxide group. Specific examples of substituted or unsubstituted diarylphosphine oxide groups include diphenylphosphine oxide and ditylphosphine oxide.

[0260] Examples of "substituted carboxyls" as substituents include benzoyloxy.

[0261] Examples of linking groups that combine multiple structures represented by formula (H4) include the 2-4 valent, 2-3 valent, or 2 valent derivatives of the aforementioned aryl and heteroaryl compounds.

[0262] Specific examples of compounds containing the structure represented by formula (H4) are shown below. [ka]

[0263] [ka]

[0264] 3-1-5-1-4. Compounds represented by formula (H5) and compounds represented by formula (H6) 3-1-5-1-4-1. Compounds represented by formula (H5) [ka]

[0265] In equation (H5), R 1 ~R 11 Each of these is independently hydrogen, aryl, heteroaryl, diarylamino, diheteroarylamino, arylheteroarylamino, or aryloxy, and at least one hydrogen in these may be further substituted with aryl, heteroaryl, or diarylamino.

[0266] Also, any at least one (preferably 1 to 3) -C(R) in formula (H5) n )=(n is 1 to 11) may be replaced with -N=.

[0267] Furthermore, at least one hydrogen atom in the compound represented by formula (H5) may be substituted with an alkyl group having 1 to 24 carbon atoms, and any -CH2- in the alkyl group may be substituted with -O- or -Si(CH3)2-, any -CH2- in the alkyl group other than the -CH2- directly attached to the compound represented by formula (H5) may be substituted with an arylene group having 6 to 24 carbon atoms, and any hydrogen atom in the alkyl group may be substituted with fluorine. Furthermore, at least one hydrogen atom in the compound represented by formula (H5) may be substituted with a halogen or deuterium.

[0268] 3-1-5-1-4-2. Compounds represented by formula (H6) [ka]

[0269] In equation (H6), R 1 ~R 16 Each of these is independently hydrogen, aryl, heteroaryl, diarylamino, diheteroarylamino, arylheteroarylamino, or aryloxy, and at least one hydrogen in these may be further substituted with aryl, heteroaryl, or diarylamino.

[0270] Furthermore, at least one hydrogen atom in the compound represented by formula (H-6) may be substituted with an alkyl group having 1 to 24 carbon atoms, and any -CH2- in the alkyl group may be substituted with -O- or -Si(CH3)2-, any -CH2- in the alkyl group other than the -CH2- directly attached to the compound represented by formula (H6) may be substituted with an arylene group having 6 to 24 carbon atoms, and any hydrogen atom in the alkyl group may be substituted with fluorine. Furthermore, at least one hydrogen atom in the compound represented by formula (H6) may be substituted with a halogen or deuterium.

[0271] 3-1-5-1-4-3. "R in equation (H5)" 1 ~R 11 " and "R in equation (H6) 1 ~R 16 " "R in equation (H5)" 1 ~R 11 " and "R in equation (H6) 1 ~R 16 Each of these is independently hydrogen, aryl, heteroaryl, diarylamino, diheteroarylamino, arylheteroarylamino, or aryloxy, with aryls having 6 to 30 carbon atoms, heteroaryls having 2 to 30 carbon atoms, diarylamino (amino having two aryls having 6 to 30 carbon atoms), diheteroarylamino (amino having two heteroaryls having 2 to 30 carbon atoms), arylheteroarylamino (amino having one aryl and one heteroaryl), or aryloxys having 6 to 30 carbon atoms.

[0272] Examples of aryl compounds include the monocyclic benzene ring, the bicyclic biphenyl ring, the fused bicyclic naphthalene ring, the tricyclic terphenyl ring (m-terphenyl, o-terphenyl, p-terphenyl), the fused tricyclic acenaphthylene ring, fluorene ring, phenalene ring, phenanthrene ring, the fused tetracyclic triphenylene ring, pyrene ring, naphthacene ring, and the fused pentacyclic perylene ring, pentacene ring. Furthermore, as will be described later, compounds in which these aryls are substituted with heteroaryls as defined below are also defined as aryls in formulas (H5) and (H6).

[0273] Examples of heteroaryls in "heteraryl," "diheterarylamino," and "arylheterarylamino" include pyrrole ring, oxazole ring, isoxazole ring, thiazole ring, isothiazole ring, imidazole ring, oxadiazole ring, thiadiazole ring, triazole ring, tetrazole ring, pyrazole ring, pyridine ring, pyrimidine ring, pyridazine ring, pyridazine ring, pyrazine ring, triazine ring, indole ring, isoindole ring, 1H-indazole ring, benzimidazole ring, benzoxazole ring, benzothiazole ring, 1H -Examples of monovalent groups include 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, indoridine rings, furan rings, benzofuran rings, isobenzofuran rings, dibenzofuran rings, thiophene rings, benzothiophene rings, dibenzothiophene rings, furazan rings, oxadiazole rings, thianthrene rings, and the aforementioned heteroaryls substituted with N-aryl. Furthermore, as will be described later, heteroaryls in which the aryls defined above are substituted with these heteroaryls are also defined as heteroaryls in formulas (H5) and (H6).

[0274] Also, R in equation (H5) 1 ~R 11 R in equation (H6) 1 ~R 16 The aryl, heteroaryl, diarylamino, diheteroarylamino, arylheteroarylamino, or aryloxy described above may have at least one hydrogen atom further substituted with an aryl, heteroaryl, or diarylamino. Examples of the aryl, heteroaryl, or diarylamino to be substituted in this way include R 1 ~R 11 Ya R 1 ~R 16 The same items as those explained in the section above can be listed.

[0275] R 1 ~R11 Ya R 1 ~R 16 Specific examples include the groups represented by formulas (RG-1) to (RG-10) below. Note that the groups represented by formulas (RG-1) to (RG-10) below bond with the a-ring to d-ring in formulas (H5) and (H6) in *.

[0276] [ka]

[0277] Referring to the specific bases mentioned above, the "aryl" and "heteroaryl" defined in formulas (H5) and (H6) are as follows: formulas (RG-1), (RG-4), and (RG-7) are aryls; formulas (RG-2), (RG-3), and (RG-6) are heteroaryls; formula (RG-9) is a heteroaryl substituted with another heteroaryl; and formula (RG-10) is an aryl substituted with another heteroaryl. Note that formula (RG-5) is an aryl(phenyl) substituted with diarylamino(diphenylamino), and formula (RG-8) is diarylamino(diphenylamino).

[0278] [ka]

[0279] 3-1-5-1-4-4. Specific Examples of Compounds The following shows more specific structures of compounds represented by formula (H5) or formula (H6). The specific structure of the compound represented by the following formula (H5) or formula (H6) may be substituted with an alkyl group having 1 to 24 carbon atoms.

[0280] [ka]

[0281] [ka]

[0282]

change

[0283]

change

[0284]

change

[0285]

change

[0286]

change

[0287]

change

[0288]

change

[0289]

change

[0290]

change

[0291]

change

[0292]

change

[0293]

change

[0294]

change

[0295]

change

[0296]

change

[0297]

change

[0298]

change

[0299]

change

[0300]

change

[0301]

change

[0302]

change

[0303] [ka]

[0304] [ka]

[0305] [ka]

[0306] 3-1-5-1-4-5. Method for producing compounds represented by formula (H5) or formula (H6) The compound represented by formula (H5) can be synthesized by first bonding the a-c rings with a bonding group (-O-) to produce an intermediate (first reaction), and then by bonding the a-c rings with a bonding group (a group containing B) to produce the final product (second reaction). Similarly, the compound represented by formula (H6) can be synthesized by first bonding the a-d rings with a bonding group (>NH or single bond) to produce an intermediate (first reaction), and then by bonding the a-d rings with a bonding group (a group containing B) to produce the final product (second reaction). In the first reaction, for example, if it is an etherification reaction, general reactions such as nucleophilic substitution reactions and Ullmann reactions can be used, and if it is an amination reaction, general reactions such as the Buchwald-Hartwig reaction can be used. In the second reaction, the tandem hetero-Friedel-Crafts reaction (sequential aromatic electrophilic substitution reaction, hereafter the same) can be used.

[0307] <Manufacturing method: Example of the second reaction of a compound represented by formula (H5)> The second reaction, as shown in scheme (1) below, is a reaction to introduce B (boron) to bond the a, b, and c rings. An example of this is the case for the compound represented by formula (H5). First, the hydrogen atom between the two oxygen atoms is orthometalated with n-butyllithium, sec-butyllithium, or t-butyllithium, etc. Next, boron trichloride or boron tribromide, etc., is added, and after a lithium-boron group 1 exchange, 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.

[0308] [ka]

[0309] In the above scheme, lithium was introduced to the desired position by orthometallation. However, as shown in scheme (2) below, bromine atoms or the like can be introduced to the desired position, and lithium can also be introduced to the desired position by halogen-metal exchange.

[0310] [ka]

[0311] By appropriately selecting the above-described synthesis method and the raw materials used, it is possible to synthesize a compound represented by formula (H-5) that has substituents at the desired positions.

[0312] <Manufacturing Method: Example of a manufacturing method for a compound represented by formula (H6)> The first and second reactions described above in the method for producing the compound represented by formula (H5) can also be applied to the method for producing the compound represented by formula (H6). Specifically, the second reaction is a reaction in which B (boron) is introduced to bond the c and d rings of NH. After orthometalating the hydrogen atom of NH with n-butyllithium, sec-butyllithium, or t-butyllithium, etc., a lithium-boron metal exchange is performed by adding boron trichloride or boron tribromide, etc., 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. Here again, a Lewis acid such as aluminum trichloride may be added in the second reaction to accelerate the reaction.

[0313] 3-1-5-1-5. Compounds containing the structure represented by formula (H8) A compound containing the structure represented by formula (H8) contains multiple structures represented by formula (H8), preferably 1 to 5, more preferably 1 to 3, even more preferably 1 to 2, and most preferably 1. If multiple structures are present, they are directly linked to each other by single bonds or by specific linking groups.

[0314] [ka]

[0315] In formula (H8), Z is either "=C(-H)-" or "=N-", and the H in "=C(-H)-" may be replaced by a structure represented by a substituent.

[0316] Examples of substituents where the H in Z, "=C(-H)-", is substituted include aryl, heteroaryl, substituted silyl, substituted phosphine oxide, and substituted carboxyl groups.

[0317] Specific examples of the substituent "aryl" include phenyl, tolyl, xylyl, triphenylenyl, fluorenyl, 9,9-dimethylfluorenyl, benzofluorenyl, dibenzofluorenyl, biphenylyl, terphenylyl, quaterphenylyl, and the like, with phenyl, biphenylyl, terphenylyl, and fluorenyl being preferred. Examples of aryls having substituents include tolyl, xylyl, and 9,9-dimethylfluorenyl. As the specific examples show, aryls include both condensed and uncondensed aryls.

[0318] Specific examples of the substituent "heteroaryl" include pyrrolyl, pyrazolyl, pyrazinyl, pyrimidinyl, pyridadinyl, pyridyl, triazinyl, indolyl, isoindolyl, imidazolyl, benzimidazolyl, indazolyl, imidazo[1,2-a]pyridinyl, furyl, benzofuranil, isobenzofuranil, dibenzofuranil, azadibenzofuranil, thienyl, benzothienyl, dibenzothienyl, azadibenzothienyl, quinolyl, isoquinolyl, quinoxalinyl, quinazolinyl, na Examples include phthalidine, carbazolyl, azacarbazol, phenanthidinyl, acridinyl, phenazinyl, phenothiazinyl, phenoxazinyl, oxazolyl, oxadiazolyl, flazanil, benzoxazolyl, thiazolyl, thiadiazolyl, benzothiazolyl, triazolyl, tetrazolyl, and the like. Preferably, examples include dibenzofuranil, dibenzothienyl, carbazolyl, pyridyl, pyrimidinyl, triazinyl, azadibenzofuranil, and azadibenzothienyl. Dibenzofuranil, dibenzothienyl, azadibenzofuranil, or azadibenzothienyl are even more preferred.

[0319] The substituent "substituted silyl" is also preferably a group selected from the group consisting of substituted or unsubstituted trialkylsilyls, substituted or unsubstituted arylalkylsilyls, and substituted or unsubstituted triarylsilyls.

[0320] Specific examples of substituted or unsubstituted trialkylsilyls include trimethylsilyl and triethylsilyl. Specific examples of substituted or unsubstituted arylalkylsilyls include diphenylmethylsilyl, ditolylmethylsilyl, and phenyldimethylsilyl. Specific examples of substituted or unsubstituted triarylsilyls include triphenylsilyl and tritolylsilyl.

[0321] The substituent, the "substituted phosphine oxide group," may preferably be a substituted or unsubstituted diarylphosphine oxide group. Specific examples of substituted or unsubstituted diarylphosphine oxide groups include diphenylphosphine oxide and ditylphosphine oxide.

[0322] Examples of "substituted carboxyls" as substituents include benzoyloxy.

[0323] Examples of linking groups that combine multiple structures represented by formula (H8) include the 2-4 valent, 2-3 valent, or 2 valent derivatives of the aforementioned aryl and heteroaryl compounds.

[0324] Specific examples of compounds containing the structure represented by formula (H8) are shown below. [ka] 3-1-5-1-6.TADF material High T1 compounds may also be TADF materials. In this specification, TADF material refers to a material that is a "thermally activated delayed phosphor." In a "thermally activated delayed phosphor," by reducing the energy difference between the excited singlet state and the excited triplet state, the reverse energy transfer from the excited triplet state to the excited singlet state, which normally has a low transition probability, is generated with high efficiency, and emission from the singlet state (thermally activated delayed fluorescence, TADF) is produced. In normal fluorescence emission, 75% of the triplet excitons generated by electric excitation pass through the thermal deactivation pathway and cannot be extracted as fluorescence. On the other hand, in TADF, all excitons can be used for fluorescence emission, enabling the realization of highly efficient organic EL devices.

[0325] Preferably, the TADF material is a donor-acceptor type TADF compound (DA type TADF compound) designed to enable efficient reverse intersystem crossing by localizing the intramolecular HOMO and LUMO using electron-donating substituents called donors and electron-accepting substituents called acceptors.

[0326] Herein, in this specification, "electron-donating substituent" (donor) means substituents and substructures in which the HOMO orbital is localized in the TADF compound molecule, and "electron-accepting substituent" (acceptor) means substituents and substructures in which the LUMO orbital is localized in the TADF compound molecule.

[0327] Generally, TADF compounds 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 ST Because of its small size, a very fast reverse intersystem crossover rate can be obtained. On the other hand, TADF compounds using donors and acceptors exhibit greater structural relaxation in the excited state (in some molecules, the stable structure differs between the ground state and the excited state, so when a conversion from the ground state to the excited state occurs due to an external stimulus, the structure subsequently changes to the stable structure in the excited state), resulting in a broad emission spectrum. Therefore, using them as luminescent materials may reduce color purity.

[0328] However, by simultaneously using the polycyclic aromatic compound represented by formula (4), the polycyclic aromatic compound represented by formula (4) functions as an emitting dopant and the TADF material functions as an assisting dopant, thereby providing high color purity. The TADF material only needs to be a compound whose emission spectrum overlaps at least partially with the absorption spectrum of the polycyclic aromatic compound represented by formula (4). The polycyclic aromatic compound represented by formula (4) and the TADF material may be contained in the same layer or in adjacent layers.

[0329] Examples of TADF materials that can be used for this purpose include compounds represented by the following formula (H7), or compounds having the following formula (H7) as a substructure.

[0330] [ka]

[0331] In formula (H7), ED is an electron-donating group, Ln is a linking group, and EA is an electron-accepting group, and the lowest excited singlet energy level (E) of the compound represented by formula (H7) is S1 ) and the lowest excited triplet energy level (E T1 The energy difference (ΔE) ST The energy difference (ΔE) is less than 0.2 eV (Hiroki Uoyama, Kenichi Goushi, Katsuyuki Shizu, Hiroko Nomura, Chihaya Adachi, Nature, 492, 234-238 (2012)). ST The voltage is preferably 0.15 eV or less, more preferably 0.10 eV or less, and even more preferably 0.08 eV or less.

[0332] For electron-donating groups (donor structures) and electron-accepting groups (acceptor structures) used in TADF materials, for example, structures described in Chemistry of Materials, 2017, 29, 1946-1963 can be used. As for ED, for example, sp 3 Examples of nitrogen-containing functional groups include groups derived from 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. Furthermore, examples of EA include sp 2Nitrogen-containing aromatic rings, CN-substituted aromatic rings, rings containing ketones, and cyanonitriles, more specifically sulfonyl dibenzene, benzophenone, phenylenebis(phenylmethanone), benzonitrile, isonicotinonitrile, phthalonitrile, isophthalonitrile, paraphthalonitrile, triazole, oxazole, thiadiazole, benzothiazole, benzobis(thiazole), benzoxazole, benzobis(oxazole), quinoline, benzimidazole, dibenzoquinoxaline, heptazphenalene, thioxanthone dioxide, dimethylamine Examples of groups derived from tracenone, anthracendione, pyridine, 5H-cyclopenta[1,2-b:5,4-b']dipyridine, benzenetricarbonitrate, fluorangecarbonitrate, pyrazinedicarbonitrate, pyridinedicarbonitrate, dibenzoquinoxalinedicarbonitrate, pyrimidine, phenylpyrimidine, methylpyrimidine, triazine, triphenyltriazine, bis(phenylsulfonyl)benzene, dimethylthioxanthenedioxide, thianthrenetetraoxide, and tris(dimethylphenyl)borane are examples. Examples of Ln include single bonds and arylenes, more specifically phenylene, biphenylene, and naphthylene. Furthermore, hydrogen may be substituted with alkyl, cycloalkyl, and aryl groups in any of the structures. In particular, it is preferable that the compound has at least one selected from carbazole, phenoxazine, acridine, triazine, pyrimidine, pyrazine, thioxanthene, benzonitrile, phthalonitrile, isophthalonitrile, diphenylsulfone, triazole, oxadiazole, thiadiazole, and benzophenone as a substructure. In equation (H7), the linking group Ln functions as a spacer structure that separates the donor substructure from the acceptor substructure.

[0333] More specifically, the compound represented by formula (H7) can be any compound represented by formula (H7-1), formula (H7-2), or formula (H7-3). [ka]

[0334] In equations (H7-1), (H7-2), and (H7-3), M is independently a single bond, -O-, >N-Ar, or >C(-Ar)2, and is preferably a single bond, -O-, or >N-Ar in terms of the depth of the HOMO of the substructure formed and the height of the lowest excited singlet energy level and the lowest excited triplet energy level. J is a linking group corresponding to Ln in formula (H7), and each is independently an arylene having 6 to 18 carbon atoms. From the viewpoint of the magnitude of conjugation leaching from the donor substructure and the acceptor substructure, arylenes having 6 to 12 carbon atoms are preferred, and more specifically, phenylene, methylphenylene, and dimethylphenylene are examples. Q is independently =C(-H)- or =N-, and from the viewpoint of the shallowness of the LUMO of the formed substructure and the height of the lowest excited singlet energy level and the lowest excited triplet energy level, it is preferably =N-. Ar is independently hydrogen, a C6-C24 aryl, a C2-C24 heteroaryl, a C1-C12 alkyl, or a C3-C18 cycloalkyl, and from the viewpoint of the depth of the HOMO of the formed substructure and the height of the lowest excited singlet energy level and the lowest excited triplet energy level, it is 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, dimethylcarbazol, di-tert-butylcarbazol, benzimidazole, or phenylbenzimidazole, and even more preferably hydrogen, phenyl, or carbazolyl. m is either 1 or 2. n is an integer between 2 and (6-m), and is preferably an integer between 4 and (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.

[0335] Examples of compounds represented by formula (H7) include those shown in the structure below. In the structural formula, * indicates a bond position, "Me" indicates methyl, and "tBu" indicates t-butyl.

[0336] [ka]

[0337] [ka]

[0338] [ka]

[0339] [ka]

[0340] [ka]

[0341] [ka]

[0342] [ka]

[0343] [ka]

[0344] [ka]

[0345] [ka]

[0346] Among the specific compounds listed above, PIC-TRZ, TXO-TPA, TXO-PhCz, PXZD SO2, ACRD SO2, DTC-DBT, DTAO, 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 are preferred as compounds represented by formula (H7).

[0347] 3-1-5-2. Dopant Materials The polycyclic aromatic compounds of the present invention are preferably used as dopant materials. The dopant material that can be used other than the polycyclic aromatic compound of the present invention is not particularly limited, and known compounds can be used, and a variety of materials can be selected according to the desired emission color.Specifically, for example, condensed ring derivatives such as phenanthrene, anthracene, pyrene, tetracene, pentacene, perylene, naphthyrene, 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.

[0348] Examples of dopant materials for each color light include blue to blue-green compounds such as naphthalene, anthracene, phenanthrene, pyrene, triphenylene, perylene, fluorene, indene, chrysene, aromatic hydrocarbon compounds and their derivatives, furan, pyrrole, thiophene, silole, 9-silafluorene, 9,9'-spirobicilafluorene, benzothiophene, benzofuran, indole, dibenzothiophene, dibenzofuran, imidazopyridine, phenanthroline, pyrazine, naphthyridine, quinoxaline, and pyrrolopy Examples include aromatic heterocyclic compounds such as lysine and thioxanthenes and their derivatives, distylylbenzene derivatives, tetraphenylbutadiene derivatives, stilbene derivatives, aldazine derivatives, coumarin derivatives, azole derivatives such as imidazole, thiazole, thiadiazole, carbazole, oxazole, oxadiazole, and triazole, and their metal complexes, as well as aromatic amine derivatives represented by N,N'-diphenyl-N,N'-di(3-methylphenyl)-4,4'-diphenyl-1,1'-diamine.

[0349] Furthermore, examples of green to yellow dopant materials include coumarin derivatives, phthalimide derivatives, naphthalimide derivatives, perinone derivatives, pyrrolopyrrole derivatives, cyclopentadiene derivatives, acridone derivatives, quinacridone derivatives, and naphthacene derivatives such as rubrene. In addition, compounds obtained by introducing substituents that enable longer wavelengths, such as aryl, heteroaryl, arylvinyl, amino, and cyano, into the compounds exemplified above as blue to blue-green dopant materials are also suitable examples.

[0350] Furthermore, suitable orange to red dopant materials include naphthalimide derivatives such as bis(diisopropylphenyl)perylenetetracarboxylic acid imide, perinone derivatives, rare earth complexes such as Eu complexes with ligands such as acetylacetone or benzoylacetone and phenanthroline, 4-(dicyanomethylene)-2-methyl-6-(p-dimethylaminostyryl)-4H-pyran and its analogs, metal phthalocyanine derivatives such as magnesium phthalocyanine and aluminum chlorophthalocyanine, rhodamine compounds, deazaflavin derivatives, coumarin derivatives, quinacridone derivatives, phenoxazine derivatives, oxazine derivatives, quinazoline derivatives, pyrrolopyridine derivatives, squarylium derivatives, biolantron derivatives, phenazine derivatives, phenoxazone derivatives, and thiadiazolopyrene derivatives. Additionally, compounds to which substituents that enable longer wavelengths, such as aryl, heteroaryl, arylvinyl, amino, and cyano, are introduced into the compounds exemplified above as blue to blue-green and green to yellow dopant materials are also suitable examples.

[0351] In addition, dopants can be appropriately selected and used from compounds listed on page 13 of the June 2004 issue of Chemical Industry and the references cited therein.

[0352] Among the dopant materials described above, amines, perylene derivatives, borane derivatives, aromatic amine derivatives, coumarin derivatives, pyran derivatives, or pyrene derivatives having a stilbene structure are particularly preferred.

[0353] Amines having a stilbene structure can be represented, for example, by the following formula. [ka] In the said formula, Ar 1 It is an m-valent group derived from aryls with 6 to 30 carbon atoms, Ar 2 and Ar 3 These are each independently aryl atoms with 6 to 30 carbon atoms, but Ar 1 ~Ar 3 At least one of them has a stilbene structure, Ar1 ~Ar 3 m may be substituted with an aryl, heteroaryl, alkyl, cycloalkyl, trisubstituted silyl (a silyl trisubstituted with an aryl, alkyl, and / or cycloalkyl) or cyano, and m is an integer from 1 to 4.

[0354] Among amines having a stilbene structure, diaminostilbene represented by the following formula is more preferred. [ka] In the said formula, Ar 2 and Ar 3 These are each independently aryl atoms with 6 to 30 carbon atoms, and Ar 2 and Ar 3 It may be substituted with an aryl, heteroaryl, alkyl, cycloalkyl, trisubstituted silyl (a silyl trisubstituted with an aryl, alkyl, and / or cycloalkyl) or cyano.

[0355] Specific examples of aryl compounds with 6 to 30 carbon atoms include phenyl, naphthyl, acenaphthirenyl, fluorenyl, phenalenyl, phenantrenyl, anthryl, fluoranthenyl, triphenylenyl, pyrenyl, crisenyl, naphthacenyl, perilenyl, stilbenyl, distyrylphenyl, distyrylbiphenyl, and distyrylfluorenyl.

[0356] Specific examples of amines having a stilbene structure include N,N,N',N'-tetra(4-biphenylyl)-4,4'-diaminostilbene, N,N,N',N'-tetra(1-naphthyl)-4,4'-diaminostilbene, N,N,N',N'-tetra(2-naphthyl)-4,4'-diaminostilbene, N,N'-di(2-naphthyl)-N,N'-diphenyl-4,4'-diaminostilbene, and N,N'-di(9-phenanthryl)-N,N'-diphenyl Examples include nyl-4,4'-diaminostilbene, 4,4'-bis[4”-bis(diphenylamino)styryl]-biphenyl, 1,4-bis[4'-bis(diphenylamino)styryl]-benzene, 2,7-bis[4'-bis(diphenylamino)styryl]-9,9-dimethylfluorene, 4,4'-bis(9-ethyl-3-carbazovinylene)-biphenyl, and 4,4'-bis(9-phenyl-3-carbazovinylene)-biphenyl. Alternatively, amines having a stilbene structure as described in Japanese Patent Publication No. 2003-347056 and Japanese Patent Publication No. 2001-307884 may be used.

[0357] Examples of perylene derivatives include 3,10-bis(2,6-dimethylphenyl)perylene, 3,10-bis(2,4,6-trimethylphenyl)perylene, 3,10-diphenylperylene, 3,4-diphenylperylene, 2,5,8,11-tetra-t-butylperylene, 3,4,9,10-tetraphenylperylene, 3-(1'-pyrenyl)-8,11-di(t-butyl)perylene, 3-(9'-anthryl)-8,11-di(t-butyl)perylene, and 3,3'-bis(8,11-di(t-butyl)peryleneyl). Furthermore, perylene derivatives described in Japanese Patent Publication No. 11-97178, Japanese Patent Publication No. 2000-133457, Japanese Patent Publication No. 2000-26324, Japanese Patent Publication No. 2001-267079, Japanese Patent Publication No. 2001-267078, Japanese Patent Publication No. 2001-267076, Japanese Patent Publication No. 2000-34234, Japanese Patent Publication No. 2001-267075, and Japanese Patent Publication No. 2001-217077 may also be used.

[0358] Examples of borane derivatives include 1,8-diphenyl-10-(dimethylboryl)anthracene, 9-phenyl-10-(dimethylboryl)anthracene, 4-(9'-anthryl)dimethylborylnaphthalene, 4-(10'-phenyl-9'-anthryl)dimethylborylnaphthalene, 9-(dimethylboryl)anthracene, 9-(4'-biphenylyl)-10-(dimethylboryl)anthracene, and 9-(4'-(N-carbazolyl)phenyl)-10-(dimethylboryl)anthracene. Alternatively, borane derivatives described in International Publication No. 2000 / 40586, etc., may be used.

[0359] Aromatic amine derivatives can be represented, for example, by the following formula. [ka] In the said formula, Ar 4 Ar is an n-valent group derived from aryl atoms with 6 to 30 carbon atoms, 5 and Ar 6 Each of these is an aryl group with 6 to 30 carbon atoms, and Ar 4 ~Ar 6 n may be substituted with an aryl, heteroaryl, alkyl, cycloalkyl, trisubstituted silyl (a silyl trisubstituted with an aryl, alkyl, and / or cycloalkyl) or cyano, and n is an integer from 1 to 4.

[0360] In particular, Ar 4 is a divalent group derived from anthracene, chrysene, fluorene, benzofluorene, or pyrene, and Ar 5 and Ar 6 Each of these is an aryl group with 6 to 30 carbon atoms, and Ar 4 ~Ar 6 Aromatic amine derivatives are more preferred, where n may be substituted with an aryl, heteroaryl, alkyl, cycloalkyl, trisubstituted silyl (trisubstituted silyl with an aryl, alkyl, and / or cycloalkyl) or cyano, and n is 2.

[0361] Specific examples of aryl compounds with 6 to 30 carbon atoms include phenyl, naphthyl, acenaphthirenyl, fluorenyl, phenalenyl, phenantrenyl, anthryl, fluoranthenyl, triphenylenyl, pyrenyl, crisenyl, naphthacenyl, perilenyl, and pentacenyl.

[0362] Examples of aromatic amine derivatives include chrysene derivatives such as N,N,N',N'-tetraphenylchrysene-6,12-diamine, N,N,N',N'-tetra(p-tolyl)chrysene-6,12-diamine, N,N,N',N'-tetra(m-tolyl)chrysene-6,12-diamine, N,N,N',N'-tetrakis(4-isopropylphenyl)chrysene-6,12-diamine, N,N,N',N'-tetra(naphthalene-2-yl)chrysene-6,12-diamine, and N,N'-diphenyl Examples include -N,N'-di(p-tolyl)chrysene-6,12-diamine, N,N'-diphenyl-N,N'-bis(4-ethylphenyl)chrysene-6,12-diamine, N,N'-diphenyl-N,N'-bis(4-isopropylphenyl)chrysene-6,12-diamine, N,N'-diphenyl-N,N'-bis(4-t-butylphenyl)chrysene-6,12-diamine, and N,N'-bis(4-isopropylphenyl)-N,N'-di(p-tolyl)chrysene-6,12-diamine.

[0363] Furthermore, pyrene-based compounds include, for example, N,N,N',N'-tetraphenylpyrene-1,6-diamine, N,N,N',N'-tetra(p-tolyl)pyrene-1,6-diamine, N,N,N',N'-tetra(m-tolyl)pyrene-1,6-diamine, N,N,N',N'-tetrakis(4-isopropylphenyl)pyrene-1,6-diamine, N,N',N'-tetrakis(3,4-dimethylphenyl)pyrene-1,6-diamine, N,N'-diphenyl-N,N'-di(p-tolyl)pyrene-1,6-diamine, N,N'-diphenyl-N,N'-bis(4-ethylphenyl)pyrene-1, 6-diamine, N,N'-diphenyl-N,N'-bis(4-isopropylphenyl)pyrene-1,6-diamine, N,N'-diphenyl-N,N'-bis(4-t-butylphenyl)pyrene-1,6-diamine, N,N'-bis(4-isopropylphenyl)-N,N'-di(p-tolyl)pyrene-1,6-diamine, N,N,N',N'-tetrakis(3,4-dimethylphenyl)-3,8-diphenylpyrene-1,6-diamine, N,N,N,N-tetraphenylpyrene-1,8-diamine, N,N'-bis(biphenyl-4-yl)-N,N'-diphenylpyrene-1,8-diamine, N 1 ,N 6 -diphenyl-N 1 ,N 6 Examples include -bis-(4-trimethylsilanylphenyl)-1H,8H-pyrene-1,6-diamine.

[0364] Furthermore, anthracene-based compounds include, for example, N,N,N,N-tetraphenylanthracene-9,10-diamine, N,N,N',N'-tetra(p-tolyl)anthracene-9,10-diamine, N,N,N',N'-tetra(m-tolyl)anthracene-9,10-diamine, N,N,N',N'-tetrakis(4-isopropylphenyl)anthracene-9,10-diamine, N,N'-diphenyl-N,N'-di(p-tolyl)anthracene-9,10-diamine, and N,N'-diphenyl-N,N'-di(m-tolyl)anthracene-9,10 -Diamine, N,N'-diphenyl-N,N'-bis(4-ethylphenyl)anthracene-9,10-diamine, N,N'-diphenyl-N,N'-bis(4-isopropylphenyl)anthracene-9,10-diamine, N,N'-diphenyl-N,N'-bis(4-t-butylphenyl)anthracene-9,10-diamine, N,N'-bis(4-isopropylphenyl)-N,N'-di(p-tolyl)anthracene-9,10-diamine, 2,6-di-t-butyl-N,N,N',N'-tetra(p-tolyl)anthracene-9,10-diamine N,6-di-t-butyl-N,N'-diphenyl-N,N'-bis(4-isopropylphenyl)anthracene-9,10-diamine, 2,6-di-t-butyl-N,N'-bis(4-isopropylphenyl)-N,N'-di(p-tolyl)anthracene-9,10-diamine, 2,6-dicyclohexyl-N,N'-bis(4-isopropylphenyl)-N,N'-di(p-tolyl)anthracene-9,10-diamine, 2,6-dicyclohexyl-N,N'-bis(4-isopropylphenyl)-N,N'-bis(4-t-butylphenyl) Examples include anthracene-9,10-diamine, 9,10-bis(4-diphenylamino-phenyl)anthracene, 9,10-bis(4-di(1-naphthylamino)phenyl)anthracene, 9,10-bis(4-di(2-naphthylamino)phenyl)anthracene, 10-di-p-tolylamino-9-(4-di-p-tolylamino-1-naphthyl)anthracene, 10-diphenylamino-9-(4-diphenylamino-1-naphthyl)anthracene, and 10-diphenylamino-9-(6-diphenylamino-2-naphthyl)anthracene.

[0365] Other examples include [4-(4-diphenylaminophenyl)naphthalen-1-yl]-diphenylamine, [6-(4-diphenylaminophenyl)naphthalen-2-yl]-diphenylamine, 4,4'-bis[4-diphenylaminonaphthalen-1-yl]biphenyl, 4,4'-bis[6-diphenylaminonaphthalen-2-yl]biphenyl, 4,4”-bis[4-diphenylaminonaphthalen-1-yl]-p-terphenyl, and 4,4”-bis[6-diphenylaminonaphthalen-2-yl]-p-terphenyl. Alternatively, aromatic amine derivatives described in Japanese Patent Publication No. 2006-156888, etc., may be used.

[0366] Examples of coumarin derivatives include coumarin-6 and coumarin-334. Furthermore, coumarin derivatives described in Japanese Patent Publication No. 2004-43646, Japanese Patent Publication No. 2001-76876, and Japanese Patent Publication No. Hei 6-298758 may also be used.

[0367] Examples of pyran derivatives include DCM and DCJTB, listed below. [ka] Furthermore, pyran derivatives described in Japanese Patent Publication No. 2005-126399, Japanese Patent Publication No. 2005-097283, Japanese Patent Publication No. 2002-234892, Japanese Patent Publication No. 2001-220577, Japanese Patent Publication No. 2001-081090, and Japanese Patent Publication No. 2001-052869 may also be used.

[0368] 3-1-5-3. Thermally activated delayed phosphors (assisting dopants) The luminescent layer may contain a thermally activated delayed phosphor as an assisting dopant. 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).

[0369] The polycyclic aromatic compound represented by formula (4) can function as an emitting dopant, and the "thermally activated delayed phosphor" can function as an assisting dopant that assists the luminescence of the polycyclic aromatic compound represented by formula (4). In the following explanation, organic electroluminescent devices that use a thermally activated delayed phosphor as an assisting dopant are sometimes referred to as "TAF devices" (TADF Assisting Fluorescence devices). In TAF devices, a "host compound" refers to a compound whose lowest excitation singlet energy level, determined from the short-wavelength shoulder of the fluorescence spectrum peak, is higher than that of the thermally activated delayed phosphor acting as the assisting dopant, and also higher than that of the emitting dopant.

[0370] Figure 2 shows the energy level diagram of the light-emitting layer of a TAF device using a common fluorescent dopant as the emitting dopant (ED). In the figure, the energy level of the host ground state is E(1,G), the lowest excited singlet energy level obtained from the short-wavelength shoulder of the host fluorescence spectrum is E(1,S,Sh), the lowest excited triplet energy level obtained from the short-wavelength shoulder of the host phosphorescence spectrum is E(1,T,Sh), the energy level of the assisting dopant ground state is E(2,G), the lowest excited singlet energy level obtained from the short-wavelength shoulder of the assisting dopant fluorescence spectrum is E(2,S,Sh), and the phosphorescence of the assisting dopant is E(2,S,Sh). E(2,T,Sh) is the lowest excited triplet energy level determined from the short-wavelength shoulder of the spectrum, E(3,G) is the ground state energy level of the emitting dopant, E(3,S,Sh) is the lowest excited singlet energy level determined from the short-wavelength shoulder of the fluorescence spectrum of the emitting dopant, and E(3,T,Sh) is the lowest excited triplet energy level determined from the short-wavelength shoulder of the phosphorescence spectrum of the emitting dopant. Let h+ represent a hole, e- represent an electron, and FRET (Fluorescence Resonance Energy Transfer) be the fluorescence resonance energy transfer. In a TAF device, when a general fluorescent dopant is used as the emitting dopant (ED), the energy upconverted by the assisting dopant is transferred to the lowest excited singlet energy level E(3,S,Sh) of the emitting dopant and emits light. However, some of the lowest excited triplet energy levels E(2,T,Sh) on the assisting dopant may move to the lowest excited triplet energy level E(3,T,Sh) on the emitting dopant, or intersystem crossing may occur on the emitting dopant from the lowest excited singlet energy level E(3,S,Sh) to the lowest excited triplet energy level E(3,T,Sh), followed by thermal deactivation to the ground state E(3,G). Due to this pathway, some energy is not used for emission, resulting in wasted energy.

[0371] In contrast, the organic electroluminescent device of this embodiment can efficiently utilize the energy transferred from the assisting dopant to the emitting dopant for light emission, thereby achieving high luminescence efficiency. This is presumed to be due to the following light emission mechanism. Figure 3 shows the preferred energy relationships in the organic electroluminescent device of this embodiment. In the organic electroluminescent device of this embodiment, the compound having a boron atom as the emitting dopant has a high lowest excited triplet energy level E(3,T,Sh). Therefore, even if the lowest excited singlet energy level upconverted by the assisting dopant undergoes intersystem crossing to the lowest excited triplet energy level E(3,T,Sh) by the emitting dopant, it is either upconverted on the emitting dopant or recovered to the lowest excited triplet energy level E(2,T,Sh) on the assisting dopant (thermally activated delayed phosphor). Thus, the generated excitation energy can be used for light emission without waste. Furthermore, by separating the upconversion and light emission functions into two types of molecules, each suited to its respective role, the residence time of high energy is reduced, and the burden on the compound is expected to decrease. In this embodiment, known host compounds can be used, for example, compounds having at least one of a carbazole ring and a furan ring, and among these, it is preferable to use a compound in which at least one of furanil and carbazolyl is bonded to at least one of arylene and heteroarylene. Specific examples include mCP and mCBP.

[0372] The lowest excited triplet energy level E(1,T,Sh), determined from the short-wavelength shoulder of the phosphorescence spectrum of the host compound, is preferably higher than the lowest excited triplet energy levels E(2,T,Sh) and E(3,T,Sh) of the emitter or assisting dopant having the highest lowest excited triplet energy level in the light-emitting layer, from the viewpoint of promoting TADF generation in the light-emitting layer without inhibiting it. Specifically, the lowest excited triplet energy level E(1,T,Sh) of the host compound is preferably 0.01 eV or higher, more preferably 0.03 eV or higher, and even more preferably 0.1 eV or higher than E(2,T,Sh) and E(3,T,Sh). Furthermore, a TADF-active compound may be used as the host compound.

[0373] 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.

[0374] Herein, in this specification, "electron-donating substituent" (donor) means substituents and substructures in which the HOMO orbital is localized in a thermally activated delayed phosphor molecule, and "electron-accepting substituent" (acceptor) means substituents and substructures in which the LUMO orbital is localized in a thermally activated delayed phosphor molecule.

[0375] 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 S1T1Because of its small size, a very fast reverse intersystem crossover rate can be obtained. On the other hand, thermally activated delayed phosphors using donors and acceptors exhibit greater structural relaxation in the excited state (in some molecules, the stable structure differs between the ground state and the excited state, so when a conversion from the ground state to the excited state occurs due to an external stimulus, the structure subsequently changes to the stable structure in the excited state), resulting in a broad emission spectrum. Therefore, using them as luminescent materials may reduce color purity.

[0376] As a thermally activated delayed phosphor in a TAF element, for example, a compound in which the donor and acceptor are directly or via a spacer can be used. As the electron-donating group (donor structure) and electron-accepting group (acceptor structure) used in the thermally activated delayed phosphor of the present invention, for example, the structures described in Chemistry of Materials, 2017, 29, 1946-1963 can be used. Examples of donor structures include carbazole, dimethylcarbazole, di-tert-butylcarbazole, dimethoxycarbazole, tetramethylcarbazole, benzofluorocarbazole, benzothienocarbazole, phenyldihydroindocarbazole, phenylbicarbazole, bicarbazole, tercarbazole, diphenylcarbazolylamine, tetraphenylcarbazolyldiamine, phenoxazine, dihydrophenazine, phenothiazine, dimethyldihydroacridine, diphenylamine, bis(tert-butylphenyl)amine, N1-(4-(diphenylamino)phenyl)-N4,N4-diphenylbenzene-1,4-diamine, dimethyltetraphenyldihydroacridinediamine, tetramethyl-dihydroindenoacridine, and diphenyl-dihydrodibenzoazacillin.Acceptor structures include sulfonyl dibenzene, benzophenone, phenylenebis(phenylmethanone), benzonitrile, isonicotinonitrile, phthalonitrile, isophthalonitrile, paraphthalonitrile, benzenetricarbonite, triazole, oxazole, thiadiazole, benzothiazole, benzobis(thiazole), benzoxazole, benzobis(oxazole), quinoline, benzimidazole, dibenzoquinoxaline, heptazaphenalene, thioxanthone dioxide, dimethylanthracenone, anthracendione, 5H-cyclopenta[1,2-b:5,4-b']dipyridine, fluorange carbonite, triphenyltriazine, pyrazinedicarbonite, pyrimidine, phenylpyrimidine, methylpyrimidine, pyridinedicarbonite, dibenzoquinoxalinedicarbonite, bis(phenylsulfonyl)benzene, dimethylthioxanthone dioxide, thianthrene tetraoxide, and tris(dimethylphenyl)borane. In particular, the compounds having thermally activated delayed fluorescence in the TAF element are preferably compounds having at least one selected from carbazole, phenoxazine, acridine, triazine, pyrimidine, pyrazine, thioxanthene, benzonitrile, phthalonitrile, isophthalonitrile, diphenylsulfone, triazole, oxadiazole, thiadiazole, and benzophenone as a substructure.

[0377] The compound used as the assisting dopant in the light-emitting layer of the TAF element is preferably a thermally activated delayed phosphor whose emission spectrum overlaps at least partially with the absorption peak of the emitting dopant.

[0378] 3-1-5-4. Phosphorescent materials (assisting dopant) In the light-emitting layer, a phosphorescent material may be used as an assisting dopant. The phosphorescent material utilizes intramolecular spin-orbit interaction (heavy atom effect) by metal atoms to obtain light emission from the triplet state. For example, a luminescent metal complex can be used as such a phosphorescent material. Examples of luminescent metal complexes include compounds represented by the following formulas (B-1) and (B-2).

[0379] [ka]

[0380] 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.

[0381] [ka]

[0382] During the ceremony, --- is bonded to the central metal M, Y is independent of BR e , NR e PR e , O, S, Se, C=O, S=O, SO2, CR e R f , SiRe R f , or GeR e R f and Each aromatic carbon CH in the ring may be independently substituted with N. R e and R f These may optionally condense or bond to form a ring. R a , R b , R c , and R d Each of these can be substituted independently, either without substitution or with 1 to the maximum number of substitutions possible. R a , R b , R c , R d , R e , and R f However, each is independently hydrogen, deuterium, halide, alkyl, cycloalkyl, heteroalkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, aryl, heteroaryl, nitrile, isonitrile, sulfanyl, or a combination thereof. However, R a , R b , R c , and R d Any two adjacent substituents in may condense or bond to form a ring or a multidentate ligand.

[0383] 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.

[0384] Other compounds represented by formula (B-1) include, for example, the following compounds. [ka]

[0385] [ka]

[0386] [ka]

[0387] Alternatively, iridium complexes described in Japanese Patent Publication No. 2006-089398, Japanese Patent Publication No. 2006-080419, Japanese Patent Publication No. 2005-298483, Japanese Patent Publication No. 2005-097263, and Japanese Patent Publication No. 2004-111379, U.S. Patent Application Publication No. 2019 / 0051845, etc., or platinum complexes described in Advanced Materials, 26: 7116-7121, NPG Asia Materials 13, 53 (2021), Applied Physics Letters, 117, 253301 (2020), Light-Emitting Diode - An Outlook On the Empirical Features and Its Recent Technological Advancements, Chapter 5 may be used.

[0388] 3-1-6. 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.

[0389] 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.

[0390] 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.

[0391] 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.

[0392] Other specific examples of electron transfer compounds include pyridine derivatives, naphthalene derivatives, anthracene derivatives, benzofluorene 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, and triazine derivatives. Examples include pyrazine derivatives, 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(4'-(2,2':6',2”-terpyridinyl))benzene), naphthyridine derivatives (such as bis(1-naphthyl)-4-(1,8-naphthyridine-2-yl)phenylphosphine oxide), aldazine derivatives, arylnitrile derivatives, indole derivatives, phosphine oxide derivatives, and bisstyryl derivatives.

[0393] 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.

[0394] The materials mentioned above can be used individually, but they can also be used in combination with other materials.

[0395] 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.

[0396] <Bolan derivatives> Borane derivatives are compounds represented by the following formula (ETM-1), for example, and are disclosed in detail in Japanese Patent Application Publication No. 2007-27587. [ka] In formula (ETM-1), R 11 and R 12 Each is independently at least one of hydrogen, alkyl, cycloalkyl, optionally substituted aryl, substituted silyl, optionally substituted nitrogen-containing heterocycle, or cyano, and R 13 ~R 16 Each of the following is independently an optionally substituted alkyl, optionally substituted cycloalkyl, or optionally substituted aryl; X is an optionally substituted arylene; Y is an optionally substituted aryl with 16 or fewer carbon atoms, a substituted boryl, or an optionally substituted carbazolyl; and each of the following is independently an integer from 0 to 3. Examples of substituents that are "optionally substituted" or "substituted" include aryl, heteroaryl, alkyl, or cycloalkyl groups.

[0397] Among the compounds represented by formula (ETM-1), compounds represented by the following formula (ETM-1-1) and compounds represented by the following formula (ETM-1-2) are preferred. [ka]

[0398] In formula (ETM-1-1), R 11 and R12 Each is independently at least one of hydrogen, alkyl, cycloalkyl, optionally substituted aryl, substituted silyl, optionally substituted nitrogen-containing heterocycle, or cyano, and R 13 ~R 16 Each of these is independently an optionally substituted alkyl, an optionally substituted cycloalkyl, or an optionally substituted aryl, and R 21 and R 22 Each is independently at least one of hydrogen, alkyl, cycloalkyl, optionally substituted aryl, substituted silyl, optionally substituted nitrogen-containing heterocycle, or cyano, and X 1 is an arylene with 20 or fewer carbon atoms, which may be substituted, where n is an independent integer between 0 and 3, and m is an independent integer between 0 and 4. Substituents that may or may be substituted include aryl, heteroaryl, alkyl, or cycloalkyl groups. [ka]

[0399] In formula (ETM-1-2), R 11 and R 12 Each is independently at least one of hydrogen, alkyl, cycloalkyl, optionally substituted aryl, substituted silyl, optionally substituted nitrogen-containing heterocycle, or cyano, and R 13 ~R 16 Each is independently an optionally substituted alkyl, an optionally substituted cycloalkyl, or an optionally substituted aryl, and X 1 is an arylene with 20 or fewer carbon atoms, which may be substituted, and n is an independent integer between 0 and 3. Substituents that may or may be substituted include aryl, heteroaryl, alkyl, or cycloalkyl groups.

[0400] X 1A specific example of this is a divalent group represented by any of the following equations (X-1) to (X-9). [ka] (In each formula, R a Each of these is independently an alkyl, cycloalkyl, or optionally substituted phenyl compound, and * represents the bond position.

[0401] Specific examples of these borane derivatives include the following compounds. [ka]

[0402] This borane derivative can be produced using known raw materials and known synthesis methods.

[0403] <Pyridine derivatives> The pyridine derivative is, for example, a compound represented by the following formula (ETM-2), and preferably a compound represented by formula (ETM-2-1) or formula (ETM-2-2). [ka]

[0404] φ is an n-valent aryl ring (preferably an n-valent benzene ring, naphthalene ring, anthracene ring, fluorene ring, benzofluorene ring, phenalene ring, phenanthrene ring, or triphenylene ring), and n is an integer from 1 to 4.

[0405] In equation (ETM-2-1), R 11 ~R 18 Each of these is independently hydrogen, alkyl (preferably alkyl having 1 to 24 carbon atoms), cycloalkyl (preferably cycloalkyl having 3 to 12 carbon atoms), or aryl (preferably aryl having 6 to 30 carbon atoms).

[0406] In equation (ETM-2-2), R 11 and R12 Each of these is independently hydrogen, alkyl (preferably alkyl with 1 to 24 carbon atoms), cycloalkyl (preferably cycloalkyl with 3 to 12 carbon atoms), or aryl (preferably aryl with 6 to 30 carbon atoms), and R 11 and R 12 They may be joined together to form a ring.

[0407] In each formula, the "pyridine substituent" is one of the following formulas (Py-1) to (Py-15) (where * indicates the bond position), and each pyridine substituent may be independently substituted with an alkyl group having 1 to 4 carbon atoms or a cycloalkyl group having 5 to 10 carbon atoms. Specific examples include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, s-butyl, or t-butyl, with methyl being preferred. Furthermore, the pyridine substituent may be bonded to the φ, anthracene ring, or fluorene ring in each formula via phenylene or naphthylene.

[0408] [ka]

[0409] The pyridine substituent is one of formulas (Py-1) to (Py-15) (where * indicates the bond position), but among these, it is preferably one of formulas (Py-21) to (Py-44) shown below. [ka]

[0410] At least one hydrogen atom in each pyridine derivative may be substituted with deuterium, and one of the two "pyridine substituents" in formulas (ETM-2-1) and (ETM-2-2) may be substituted with an aryl atom.

[0411] R 11 ~R 18The "alkyl" in this context can be either linear or branched, for example, a linear alkyl group with 1 to 24 carbon atoms or a branched alkyl group with 3 to 24 carbon atoms. A preferred "alkyl" is an alkyl group with 1 to 18 carbon atoms (a branched alkyl group with 3 to 18 carbon atoms). A more preferred "alkyl" is an alkyl group with 1 to 12 carbon atoms (a branched alkyl group with 3 to 12 carbon atoms). A still preferred "alkyl" is an alkyl group with 1 to 6 carbon atoms (a branched alkyl group with 3 to 6 carbon atoms). A particularly preferred "alkyl" is an alkyl group with 1 to 4 carbon atoms (a branched alkyl group with 3 to 4 carbon atoms).

[0412] Specific examples of "alkyl" include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, s-butyl, t-butyl, n-pentyl, isopentyl, neopentyl, t-pentyl, n-hexyl, 1-methylpentyl, 4-methyl-2-pentyl, 3,3-dimethylbutyl, 2-ethylbutyl, n-heptyl, 1-methylhexyl, n-octyl, t-octyl, 1-methylheptyl, Examples include 2-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.

[0413] For alkyl groups with 1 to 4 carbon atoms to be substituted for pyridine substituents, the above description of alkyl groups can be referenced.

[0414] R 11 ~R 18 Examples of "cycloalkyl" in this context include cycloalkyls having 3 to 12 carbon atoms. Preferred "cycloalkyl" are cycloalkyls having 3 to 10 carbon atoms. More preferred "cycloalkyl" are cycloalkyls having 3 to 8 carbon atoms. Even more preferred "cycloalkyl" are cycloalkyls having 3 to 6 carbon atoms. Specific examples of "cycloalkyl" compounds include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, methylcyclopentyl, cycloheptyl, methylcyclohexyl, cyclooctyl, or dimethylcyclohexyl.

[0415] R 11 ~R 18 In this context, the preferred aryl is an aryl having 6 to 30 carbon atoms, a more preferred aryl is an aryl having 6 to 18 carbon atoms, an even more preferred aryl is an aryl having 6 to 14 carbon atoms, and a particularly preferred aryl is an aryl having 6 to 12 carbon atoms.

[0416] Specific examples of "aryl compounds with 6 to 30 carbon atoms" include the monocyclic aryl phenyl, the condensed bicyclic aryl (1-,2-)naphthyl, the condensed tricyclic aryls acenaphthylene-(1-,3-,4-,5-)yl, fluoren-(1-,2-,3-,4-,9-)yl, phenalen-(1-,2-)yl, (1-,2-,3-,4-,9-)phenanthryl, the condensed tetracyclic aryls triphenylene-(1-,2-)yl, pyren-(1-,2-,4-)yl, naphthacene-(1-,2-,5-)yl, and the condensed pentacyclic aryls perylene-(1-,2-,3-)yl, pentacene-(1-,2-,5-,6-)yl.

[0417] Preferred "aryl compounds having 6 to 30 carbon atoms" include phenyl, naphthyl, phenanthryl, crisenyl, or triphenylenyl, more preferably phenyl, 1-naphthyl, 2-naphthyl, or phenanthryl, and particularly preferably phenyl, 1-naphthyl, or 2-naphthyl.

[0418] R in equation (ETM-2-2) 11 and R 12 These may be bonded together to form a ring, and as a result, cyclobutane, cyclopentane, cyclopentene, cyclopentadiene, cyclohexane, fluorene, or indene may be spirobonded to the five-membered ring of the fluorene skeleton.

[0419] Specific examples of this pyridine derivative include the following compounds, for example. [Chemical Formula]

[0420] This pyridine derivative can be produced using known raw materials and known synthetic methods.

[0421] <Fluoranthene Derivative> The fluoranthene derivative is, for example, a compound represented by the following formula (ETM-3), and is specifically disclosed in International Publication No. WO 2010 / 134352. [Chemical Formula]

[0422] In formula (ETM-3), X 12 to X 21 each represent hydrogen, halogen, linear, branched or cyclic alkyl, linear, branched or cyclic alkoxy, substituted or unsubstituted aryl, or substituted or unsubstituted heteroaryl. Here, when substituted, examples of the substituent include aryl, heteroaryl, alkyl and cycloalkyl.

[0423] Specific examples of this fluoranthene derivative include the following compounds, for example. [Chemical Formula]

[0424] <BO-based Derivative> The BO-based derivative is, for example, a polycyclic aromatic compound represented by the following formula (ETM-4), or a multimer of a polycyclic aromatic compound having a plurality of structures represented by the following formula (ETM-4). [Chemical Formula]

[0425] R 1 ~R 11 Each of these is independently a hydrogen, aryl, heteroaryl, diarylamino, diheteroarylamino, arylheteroarylamino, alkyl, cycloalkyl, alkoxy, or aryloxy, wherein at least one hydrogen in each may be substituted with an aryl, heteroaryl, alkyl, or cycloalkyl.

[0426] Also, R 1 ~R 11 Adjacent groups among them may bond together to form an aryl ring or heteroaryl ring with the a, b, or c ring, and at least one hydrogen in the formed ring may be substituted with aryl, heteroaryl, diarylamino, diheteroarylamino, arylheteroarylamino, alkyl, cycloalkyl, alkoxy, or aryloxy, and at least one hydrogen in these may be substituted with aryl, heteroaryl, alkyl, or cycloalkyl.

[0427] Furthermore, at least one hydrogen atom in the compound or structure represented by formula (ETM-4) may be substituted with a halogen or deuterium.

[0428] For an explanation of the substituents and ring formation morphology in formula (ETM-4), refer to the explanation of polycyclic aromatic compounds represented by formula (4).

[0429] Specific examples of these BO derivatives include the following compounds. [ka]

[0430] This BO derivative can be produced using known raw materials and known synthesis methods.

[0431] <Benzofluorene derivatives> Benzofluorene derivatives are compounds represented by the following formula (ETM-6), for example. [ka]

[0432] Ar 1 Each of these is an aryl group with 6 to 20 carbon atoms, and is represented by the formula (ETM-5) Ar 2 The same explanation as for "aryls with 6 to 20 carbon atoms" can be cited. Aryls with 6 to 16 carbon atoms are preferred, aryls with 6 to 12 carbon atoms are more preferred, and aryls with 6 to 10 carbon atoms are particularly preferred. Specific examples include phenyl, biphenylyl, naphthyl, terphenylyl, anthracenyl, acenaphthirenyl, fluorenyl, phenalenyl, phenanthryl, triphenylenyl, pyrenyl, tetracenyl, and perilenyl.

[0433] Ar 2 Each of these is independently hydrogen, alkyl (preferably alkyl with 1 to 24 carbon atoms), cycloalkyl (preferably cycloalkyl with 3 to 12 carbon atoms), or aryl (preferably aryl with 6 to 30 carbon atoms), and two Ar 2 They may be joined together to form a ring.

[0434] Ar 2The "alkyl" in this context can be either linear or branched, for example, a linear alkyl group with 1 to 24 carbon atoms or a branched alkyl group with 3 to 24 carbon atoms. A preferred "alkyl" is an alkyl group with 1 to 18 carbon atoms (a branched alkyl group with 3 to 18 carbon atoms). A more preferred "alkyl" is an alkyl group with 1 to 12 carbon atoms (a branched alkyl group with 3 to 12 carbon atoms). A still preferred "alkyl" is an alkyl group with 1 to 6 carbon atoms (a branched alkyl group with 3 to 6 carbon atoms). A particularly preferred "alkyl" is an alkyl group with 1 to 4 carbon atoms (a branched alkyl group with 3 to 4 carbon atoms). Specific examples of "alkyl" include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, s-butyl, t-butyl, n-pentyl, isopentyl, neopentyl, t-pentyl, n-hexyl, 1-methylpentyl, 4-methyl-2-pentyl, 3,3-dimethylbutyl, 2-ethylbutyl, n-heptyl, and 1-methylhexyl.

[0435] Ar 2 Examples of "cycloalkyl" in this context include cycloalkyls having 3 to 12 carbon atoms. Preferred "cycloalkyls" are those having 3 to 10 carbon atoms. More preferred "cycloalkyls" are those having 3 to 8 carbon atoms. Even more preferred "cycloalkyls" are those having 3 to 6 carbon atoms. Specific examples of "cycloalkyls" include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, methylcyclopentyl, cycloheptyl, methylcyclohexyl, cyclooctyl, or dimethylcyclohexyl.

[0436] Ar 2 In this context, the preferred aryl is an aryl having 6 to 30 carbon atoms, a more preferred aryl is an aryl having 6 to 18 carbon atoms, an even more preferred aryl is an aryl having 6 to 14 carbon atoms, and a particularly preferred aryl is an aryl having 6 to 12 carbon atoms.

[0437] Specific examples of "aryl compounds with 6 to 30 carbon atoms" include phenyl, naphthyl, acenaphthirenyl, fluorenyl, phenalenyl, phenanthryl, triphenylenyl, pyrenyl, naphthacenyl, perilenyl, and pentacenyl.

[0438] Two Ar 2 These may be bonded together to form a ring, and as a result, cyclobutane, cyclopentane, cyclopentene, cyclopentadiene, cyclohexane, fluorene, or indene may be spirobonded to the five-membered ring of the fluorene skeleton.

[0439] Specific examples of these benzofluorene derivatives include the following compounds: [ka]

[0440] This benzofluorene derivative can be produced using known raw materials and known synthesis methods.

[0441] <Phosphine oxide derivatives> Phosphine oxide derivatives are compounds represented by formula (ETM-7-1) below, for example. Further details are also described in International Publication Nos. 2013 / 079217 and 2013 / 079678. [ka]

[0442] R 5 These are substituted or unsubstituted alkyl groups with 1 to 20 carbon atoms, cycloalkyl groups with 3 to 16 carbon atoms, aryl groups with 6 to 20 carbon atoms, or heteroaryl groups with 5 to 20 carbon atoms. R 6 These are CN, substituted or unsubstituted alkyl groups having 1 to 20 carbon atoms, cycloalkyl groups having 3 to 16 carbon atoms, heteroalkyl groups having 1 to 20 carbon atoms, aryl groups having 6 to 20 carbon atoms, heteroaryl groups having 5 to 20 carbon atoms, alkoxy groups having 1 to 20 carbon atoms, or aryloxy groups having 6 to 20 carbon atoms. R 7 and R 8 These are, independently, substituted or unsubstituted aryls with 6 to 20 carbon atoms or heteroaryls with 5 to 20 carbon atoms. R 9 It is oxygen or sulfur, j is 0 or 1, k is 0 or 1, r is an integer between 0 and 4, and q is an integer between 1 and 3. Examples of substituents that may be substituted include aryl, heteroaryl, alkyl, or cycloalkyl compounds.

[0443] The phosphine oxide derivative may be, for example, a compound represented by the following formula (ETM-7-2). [ka]

[0444] R 1 ~R 3 These may be the same or different, and are selected from hydrogen, alkyl, cycloalkyl, aralkyl, alkenyl, cycloalkenyl, alkynyl, alkoxy, alkylthio, cycloalkylthio, aryl ether (aryl ether group), arylthioether (arylthioether group), aryl, heterocyclic group, halogen, cyano, aldehyde, carbonyl, carboxyl, amino, nitro, silyl, and condensed rings formed between adjacent substituents.

[0445] Ar 1 These can be the same or different, and are either arylenes or heteroarylenes. 2 They may be the same or different, and are aryl or heteroaryl. However, Ar 1 and Ar 2 At least one of these molecules has a substituent or forms a fused ring with an adjacent substituent. n is an integer from 0 to 3, and when n is 0, there is no unsaturated structural part, and when n is 3, R 1 It does not exist.

[0446] Of these substituents, alkyl refers to saturated aliphatic hydrocarbon groups such as methyl, ethyl, propyl, and butyl, which may be unsubstituted or substituted. There are no particular restrictions on the substituents when substituted; for example, alkyl, aryl, and heterocyclic groups can be used, and this point is also common to the following description. Furthermore, the number of carbon atoms in alkyl is not particularly limited, but for reasons of availability and cost, it is usually in the range of 1 to 20.

[0447] Furthermore, cycloalkyl refers to saturated alicyclic hydrocarbon groups such as cyclopropyl, cyclohexyl, norbornyl, and adamantyl, which may be unsubstituted or substituted. The number of carbon atoms in the alkyl portion is not particularly limited, but is usually in the range of 3 to 20.

[0448] Furthermore, aralkyl refers to an aromatic hydrocarbon group mediated by an aliphatic hydrocarbon such as benzyl or phenylethyl, and both the aliphatic and aromatic hydrocarbons may be unsubstituted or substituted. The number of carbon atoms in the aliphatic portion is not particularly limited, but is usually in the range of 1 to 20.

[0449] Furthermore, an alkenyl refers to an unsaturated aliphatic hydrocarbon group containing a double bond, such as vinyl, allyl, or butadienyl, which may be unsubstituted or substituted. The number of carbon atoms in an alkenyl is not particularly limited, but is usually in the range of 2 to 20.

[0450] Furthermore, cycloalkenyl refers to unsaturated alicyclic hydrocarbon groups containing double bonds, such as cyclopentenyl, cyclopentadienyl, and cyclohexenyl, which may be unsubstituted or substituted.

[0451] Furthermore, "alkynyl" refers to an unsaturated aliphatic hydrocarbon group containing a triple bond, such as acetylenyl, which may be unsubstituted or substituted. The number of carbon atoms in an alkynyl group is not particularly limited, but is usually in the range of 2 to 20.

[0452] Furthermore, an alkoxy refers to an aliphatic hydrocarbon group mediated by an ether bond, such as methoxy, and the aliphatic hydrocarbon group may be unsubstituted or substituted. The number of carbon atoms in an alkoxy is not particularly limited, but is usually in the range of 1 to 20.

[0453] Furthermore, alkylthio is a group in which the oxygen atom in the ether bond of an alkoxy group is replaced by a sulfur atom.

[0454] Furthermore, cycloalkylthio is a group in which the oxygen atom in the ether bond of a cycloalkoxy is replaced by a sulfur atom.

[0455] Furthermore, an aryl ether refers to an aromatic hydrocarbon group mediated by an ether bond, such as phenoxy, and the aromatic hydrocarbon group may be unsubstituted or substituted. The number of carbon atoms in an aryl ether is not particularly limited, but is usually in the range of 6 to 40.

[0456] Furthermore, an arylthioether is a group in which the oxygen atom in the ether bond of an aryl ether is replaced by a sulfur atom.

[0457] Furthermore, "aryl" refers to aromatic hydrocarbon groups such as phenyl, naphthyl, biphenylyl, phenanthryl, terphenylyl, and pyrenyl. Aryls can be unsubstituted or substituted. The number of carbon atoms in an aryl group is not particularly limited, but is usually in the range of 6 to 40.

[0458] Furthermore, heterocyclic groups refer to cyclic structural groups that have atoms other than carbon, such as furanyl, thienyl, oxazolyl, pyridyl, quinolinyl, and carbazolyl, and these can be unsubstituted or substituted. The number of carbon atoms in a heterocyclic group is not particularly limited, but it is usually in the range of 2 to 30.

[0459] Halogens refer to fluorine, chlorine, bromine, and iodine.

[0460] Aldehydes, carbonyls, and aminos can also include groups substituted with aliphatic hydrocarbons, alicyclic hydrocarbons, aromatic hydrocarbons, heterocyclic groups, etc.

[0461] Furthermore, aliphatic hydrocarbons, alicyclic hydrocarbons, aromatic hydrocarbons, and heterocyclic hydrocarbons may be unsubstituted or substituted.

[0462] Silyl refers to a silicon compound group, such as trimethylsilyl, which can be unsubstituted or substituted. The number of carbon atoms in a silyl group is not particularly limited, but is usually in the range of 3 to 20. The number of silicon atoms is usually between 1 and 6.

[0463] The fused ring formed between adjacent substituents is, for example, Ar 1 and R 2 Ar 1 and R 3 Ar 2 and R 2 Ar 2 and R 3 , R 2 and R 3 Ar 1 and Ar 2 It is a conjugated or unconjugated fused ring formed between the following elements. Here, when n is 1, two R 1 These rings may form conjugated or non-conjugated fused rings. These fused rings may contain nitrogen, oxygen, and sulfur atoms in their intraring structure, and may also be fused with other rings.

[0464] Specific examples of these phosphine oxide derivatives include the following compounds. [ka]

[0465] This phosphine oxide derivative can be produced using known raw materials and known synthesis methods.

[0466] <Pyrimidine derivatives> The pyrimidine derivative is, for example, a compound represented by the following formula (ETM-8), and preferably a compound represented by the following formula (ETM-8-1). Further details are also described in International Publication No. 2011 / 021689. [ka]

[0467] Each Ar is independently a substituted or substituted heteroaryl. n is an integer from 1 to 4, preferably from 1 to 3, and more preferably 2 or 3.

[0468] Examples of the "aryl" in "aryl which may be substituted" include aryls having 6 to 30 carbon atoms, preferably aryls having 6 to 24 carbon atoms, more preferably aryls having 6 to 20 carbon atoms, and even more preferably aryls having 6 to 12 carbon atoms.

[0469] Specific examples of "aryl" include monocyclic aryls such as phenyl, bicyclic aryls such as (2-,3-,4-)biphenylyl, condensed bicyclic aryls such as (1-,2-)naphthyl, tricyclic aryls such as 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, p-terphenyl-4-yl), and condensed tricyclic aryls. Examples of aryl compounds include acenaphthylene-(1-,3-,4-,5-)yl, fluoren-(1-,2-,3-,4-,9-)yl, phenalen-(1-,2-)yl, (1-,2-,3-,4-,9-)phenanthryl; tetracyclic aryl compounds include quaterphenylyl (5'-phenyl-m-terphenyl-2-yl, 5'-phenyl-m-terphenyl-3-yl, 5'-phenyl-m-terphenyl-4-yl, m-quaterphenylyl); condensed tetracyclic aryl compounds include triphenylene-(1-,2-)yl, pyren-(1-,2-,4-)yl, naphthacene-(1-,2-,5-)yl; and condensed pentacyclic aryl compounds include perylene-(1-,2-,3-)yl, pentacene-(1-,2-,5-,6-)yl.

[0470] Examples of "heteroaryls that may be substituted" include heteroaryls having 2 to 30 carbon atoms, with heteroaryls having 2 to 25 carbon atoms being preferred, heteroaryls having 2 to 20 carbon atoms being more preferred, heteroaryls having 2 to 15 carbon atoms being even more preferred, and heteroaryls having 2 to 10 carbon atoms being particularly preferred. Examples of heteroaryls include heterocycles containing 1 to 5 heteroatoms selected from oxygen, sulfur, and nitrogen in addition to carbon as ring constituent atoms.

[0471] Specific heteroaryl compounds include, for example, furyl, thienyl, pyrrolyl, oxazolyl, isoxazolyl, thiazolyl, isothiazolyl, imidazolyl, pyrazolyl, oxadiazolyl, flazanil, thiadiazolyl, triazolyl, tetrazolyl, pyridyl, pyrimidinil, pyridadinil, pyrazinil, triazinil, benzofuranil, isobenzofuranil, benzo[b]thienyl, indolyl, isoindolyl, 1H-indazolyl, benzimidazolyl, benzoxazolyl, benzothiazolyl, 1H-benzotriazolyl, quinolyl, isoquinolyl, cinnolyl, quinazolyl, quinoxalinil, phthalazinil, naphthilidinil, prinyl, pteridinil, carbazolyl, acridinil, phenoxazinil, phenothiazinil, phenazinil, phenoxathiinil, thianthrenil, and indolidinil.

[0472] Furthermore, the above-mentioned aryl and heteroaryl may be substituted, for example, they may be substituted with the above-mentioned aryl or heteroaryl.

[0473] Specific examples of these pyrimidine derivatives include the following compounds. [ka]

[0474] This pyrimidine derivative can be produced using known raw materials and known synthesis methods.

[0475] <Arylnitrile derivatives> Arylnitrile derivatives are compounds represented by formula (ETM-9) below, for example, or polymers formed by the linkage of multiple such compounds via single bonds or other means. Further details are described in U.S. Patent Application Publication No. 2014 / 0197386. [ka]

[0476] Ar niFrom the viewpoint of fast electron transport, a high number of carbon atoms is preferable, and from the viewpoint of high T1, a low number of carbon atoms is preferable. ni Specifically, for use in a layer adjacent to the light-emitting layer, it is preferable to have a high T1, and is an aryl group having 6 to 20 carbon atoms, preferably an aryl group having 6 to 14 carbon atoms, and more preferably an aryl group having 6 to 10 carbon atoms. Furthermore, the number of substituted nitrile groups n is preferably large from the viewpoint of high T1, and preferably small from the viewpoint of high S1. Specifically, the number of substituted nitrile groups n is an integer from 1 to 4, preferably an integer from 1 to 3, more preferably an integer from 1 to 2, and even more preferably 1.

[0477] Each Ar is independently a substituted or substituted heteroaryl. From the viewpoint of high S1 and high T1, a donor heteroaryl is preferred, and since it is used as an electron transport layer, it is preferable to have few donor heteroaryls. From the viewpoint of charge transport, an aryl or heteroaryl with a large number of carbon atoms is preferred, and it is preferable to have many substituents. Specifically, the number of substitutions m of Ar is an integer from 1 to 4, preferably an integer from 1 to 3, and more preferably 1 to 2.

[0478] Examples of the "aryl" in "aryl which may be substituted" include aryls having 6 to 30 carbon atoms, preferably aryls having 6 to 24 carbon atoms, more preferably aryls having 6 to 20 carbon atoms, and even more preferably aryls having 6 to 12 carbon atoms.

[0479] Specific examples of "aryl" include monocyclic aryls such as phenyl, bicyclic aryls such as (2-,3-,4-)biphenylyl, condensed bicyclic aryls such as (1-,2-)naphthyl, tricyclic aryls such as 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, p-terphenyl-4-yl), and condensed tricyclic aryls. Examples of aryl compounds include acenaphthylene-(1-,3-,4-,5-)yl, fluoren-(1-,2-,3-,4-,9-)yl, phenalen-(1-,2-)yl, (1-,2-,3-,4-,9-)phenanthryl; tetracyclic aryl compounds include quaterphenylyl (5'-phenyl-m-terphenyl-2-yl, 5'-phenyl-m-terphenyl-3-yl, 5'-phenyl-m-terphenyl-4-yl, m-quaterphenylyl); condensed tetracyclic aryl compounds include triphenylene-(1-,2-)yl, pyren-(1-,2-,4-)yl, naphthacene-(1-,2-,5-)yl; and condensed pentacyclic aryl compounds include perylene-(1-,2-,3-)yl, pentacene-(1-,2-,5-,6-)yl.

[0480] Examples of "heteroaryls that may be substituted" include heteroaryls having 2 to 30 carbon atoms, with heteroaryls having 2 to 25 carbon atoms being preferred, heteroaryls having 2 to 20 carbon atoms being more preferred, heteroaryls having 2 to 15 carbon atoms being even more preferred, and heteroaryls having 2 to 10 carbon atoms being particularly preferred. Examples of heteroaryls include heterocycles containing 1 to 5 heteroatoms selected from oxygen, sulfur, and nitrogen in addition to carbon as ring constituent atoms.

[0481] Specific heteroaryl compounds include, for example, furyl, thienyl, pyrrolyl, oxazolyl, isoxazolyl, thiazolyl, isothiazolyl, imidazolyl, pyrazolyl, oxadiazolyl, flazanil, thiadiazolyl, triazolyl, tetrazolyl, pyridyl, pyrimidinil, pyridadinil, pyrazinil, triazinil, benzofuranil, isobenzofuranil, benzo[b]thienyl, indolyl, isoindolyl, 1H-indazolyl, benzimidazolyl, benzoxazolyl, benzothiazolyl, 1H-benzotriazolyl, quinolyl, isoquinolyl, cinnolyl, quinazolyl, quinoxalinil, phthalazinil, naphthilidinil, prinyl, pteridinil, carbazolyl, acridinil, phenoxazinil, phenothiazinil, phenazinil, phenoxathiinil, thianthrenil, and indolidinil.

[0482] Furthermore, the above-mentioned aryl and heteroaryl may be substituted, for example, they may be substituted with the above-mentioned aryl or heteroaryl.

[0483] The arylnitrile derivative may be a polymer in which multiple compounds represented by formula (ETM-9) are linked by single bonds or other means. In this case, in addition to single bonds, the linkage may also be by aryl rings (preferably polyvalent benzene rings, naphthalene rings, anthracene rings, fluorene rings, benzofluorene rings, phenalene rings, phenanthrene rings, or triphenylene rings).

[0484] Specific examples of these arylnitrile derivatives include the following compounds. [ka]

[0485] This arylnitrile derivative can be produced using known raw materials and known synthesis methods.

[0486] <Triadine derivatives> The triazine derivative is, for example, a compound represented by the following formula (ETM-10), and preferably a compound represented by the following formula (ETM-10-1). Further details are described in U.S. Patent Application Publication No. 2011 / 0156013. [ka]

[0487] Each Ar is independently a substituted or substituted heteroaryl. n is an integer between 1 and 3, preferably 2 or 3.

[0488] Examples of the "aryl" in "aryl which may be substituted" include aryls having 6 to 30 carbon atoms, preferably aryls having 6 to 24 carbon atoms, more preferably aryls having 6 to 20 carbon atoms, and even more preferably aryls having 6 to 12 carbon atoms.

[0489] Specific examples of "aryl" include monocyclic aryls such as phenyl, bicyclic aryls such as (2-,3-,4-)biphenylyl, condensed bicyclic aryls such as (1-,2-)naphthyl, tricyclic aryls such as 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, p-terphenyl-4-yl), and condensed tricyclic aryls. Examples of aryl compounds include acenaphthylene-(1-,3-,4-,5-)yl, fluoren-(1-,2-,3-,4-,9-)yl, phenalen-(1-,2-)yl, (1-,2-,3-,4-,9-)phenanthryl; tetracyclic aryl compounds include quaterphenylyl (5'-phenyl-m-terphenyl-2-yl, 5'-phenyl-m-terphenyl-3-yl, 5'-phenyl-m-terphenyl-4-yl, m-quaterphenylyl); condensed tetracyclic aryl compounds include triphenylene-(1-,2-)yl, pyren-(1-,2-,4-)yl, naphthacene-(1-,2-,5-)yl; and condensed pentacyclic aryl compounds include perylene-(1-,2-,3-)yl, pentacene-(1-,2-,5-,6-)yl.

[0490] Examples of "heteroaryls that may be substituted" include heteroaryls having 2 to 30 carbon atoms, with heteroaryls having 2 to 25 carbon atoms being preferred, heteroaryls having 2 to 20 carbon atoms being more preferred, heteroaryls having 2 to 15 carbon atoms being even more preferred, and heteroaryls having 2 to 10 carbon atoms being particularly preferred. Examples of heteroaryls include heterocycles containing 1 to 5 heteroatoms selected from oxygen, sulfur, and nitrogen in addition to carbon as ring constituent atoms.

[0491] Specific heteroaryl compounds include, for example, furyl, thienyl, pyrrolyl, oxazolyl, isoxazolyl, thiazolyl, isothiazolyl, imidazolyl, pyrazolyl, oxadiazolyl, flazanil, thiadiazolyl, triazolyl, tetrazolyl, pyridyl, pyrimidinil, pyridadinil, pyrazinil, triazinil, benzofuranil, isobenzofuranil, benzo[b]thienyl, indolyl, isoindolyl, 1H-indazolyl, benzimidazolyl, benzoxazolyl, benzothiazolyl, 1H-benzotriazolyl, quinolyl, isoquinolyl, cinnolyl, quinazolyl, quinoxalinil, phthalazinil, naphthilidinil, prinyl, pteridinil, carbazolyl, acridinil, phenoxazinil, phenothiazinil, phenazinil, phenoxathiinil, thianthrenil, and indolidinil.

[0492] Furthermore, the above-mentioned aryl and heteroaryl may be substituted, for example, they may be substituted with the above-mentioned aryl or heteroaryl.

[0493] Specific examples of these triazine derivatives include the following compounds. [ka]

[0494] This triazine derivative can be produced using known raw materials and known synthesis methods.

[0495] <Benzimidazole derivatives> Benzimidazole derivatives are compounds represented by, for example, the following formula (ETM-11). [ka]

[0496] φ is an n-valent aryl ring (preferably an n-valent benzene ring, naphthalene ring, anthracene ring, fluorene ring, benzofluorene ring, phenalene ring, phenanthrene ring, or triphenylene ring), n is an integer from 1 to 4, and the "benzimidazole substituent" is a substituent in which the pyridyl in the "pyridine substituent" in formulas (ETM-2), (ETM-2-1), and (ETM-2-2) is replaced with the benzimidazol (wherein * indicates the bond position), and at least one hydrogen in the benzimidazole derivative may be substituted with deuterium.

[0497] [ka]

[0498] R in the above benzimidazolyl 11 R is hydrogen, an alkyl group having 1 to 24 carbon atoms, a cycloalkyl group having 3 to 12 carbon atoms, or an aryl group having 6 to 30 carbon atoms, and R in formulas (ETM-2-1) and (ETM-2-2) 11 You can quote the explanation.

[0499] φ is further preferably an anthracene ring or a fluorene ring, and the structure in this case can be described by referring to formula (ETM-2-1) or formula (ETM-2-2), where R in each formula 11 ~R 18 The explanation in formula (ETM-2-1) or formula (ETM-2-2) can be cited. Also, although formula (ETM-2-1) or formula (ETM-2-2) is explained in a form in which two pyridine substituents are bonded, when replacing these with benzimidazole substituents, both pyridine substituents may be replaced with benzimidazole substituents (i.e., n=2), or one of the pyridine substituents may be replaced with a benzimidazole substituent and the other pyridine substituent may be R 11 ~R 18 It can also be replaced with (i.e., n=1). Furthermore, for example, R in equation (ETM-2-1) 11 ~R 18Replace at least one of the "pyridine substituents" with a benzimidazole substituent and R 11 ~R 18 You can replace it with this.

[0500] Specific examples of these benzimidazole derivatives include, for example, 1-phenyl-2-(4-(10-phenylanthracene-9-yl)phenyl)-1H-benzo[d]imidazole, 2-(4-(10-(naphthalene-2-yl)anthracene-9-yl)phenyl)-1-phenyl-1H-benzo[d]imidazole, 2-(3-(10-(naphthalene-2-yl)anthracene-9-yl)phenyl)-1-phenyl-1H-benzo[d]imidazole, and 5-(10-(naphthalene-2-yl)anthracene-9-yl)-1,2-diphenyl-1H-benzo[d]imidazole Examples include 1-(4-(10-(naphthalene-2-yl)anthracene-9-yl)phenyl)-2-phenyl-1H-benzo[d]imidazole, 2-(4-(9,10-di(naphthalene-2-yl)anthracene-2-yl)phenyl)-1-phenyl-1H-benzo[d]imidazole, 1-(4-(9,10-di(naphthalene-2-yl)anthracene-2-yl)phenyl)-2-phenyl-1H-benzo[d]imidazole, and 5-(9,10-di(naphthalene-2-yl)anthracene-2-yl)-1,2-diphenyl-1H-benzo[d]imidazole.

[0501] [ka]

[0502] This benzimidazole derivative can be produced using known raw materials and known synthesis methods.

[0503] <Phenanthroline derivatives> Phenanthroline derivatives are compounds represented, for example, by the following formulas (ETM-12) or (ETM-12-1). Further details are described in International Publication No. 2006 / 021982. [ka]

[0504] φ is an n-valent aryl ring (preferably an n-valent benzene ring, naphthalene ring, anthracene ring, fluorene ring, benzofluorene ring, phenalene ring, phenanthrene ring, or triphenylene ring), and n is an integer from 1 to 4.

[0505] R in each formula 11 ~R 18 Each of these is independently hydrogen, alkyl (preferably alkyl with 1 to 24 carbon atoms), cycloalkyl (preferably cycloalkyl with 3 to 12 carbon atoms), or aryl (preferably aryl with 6 to 30 carbon atoms). Also, in formula (ETM-12-1), R 11 ~R 18 One of these forms a bond with the aryl ring φ.

[0506] At least one hydrogen atom in each phenanthroline derivative may be substituted with deuterium.

[0507] R 11 ~R 18 The alkyl, cycloalkyl, and aryl elements in formula (ETM-2) are R 11 ~R 18 The explanation can be quoted. In addition to the examples above, φ can also be represented by the following structural formula. Note that in the following structural formulas, R is independently hydrogen, methyl, ethyl, isopropyl, cyclohexyl, phenyl, 1-naphthyl, 2-naphthyl, biphenylyl, or terphenylyl, and * indicates the bond position.

[0508] [ka]

[0509] Specific examples of phenanthroline derivatives include, for example, 4,7-diphenyl-1,10-phenanthroline, 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline, 9,10-di(1,10-phenanthroline-2-yl)anthracene, 2,6-di(1,10-phenanthroline-5-yl)pyridine, 1,3,5-tri(1,10-phenanthroline-5-yl)benzene, 9,9'-difluoro-bi(1,10-phenanthroline-5-yl), basocproine, 1,3-bis(2-phenyl-1,10-phenanthroline-9-yl)benzene, and compounds represented by the following structural formula. [ka]

[0510] This phenanthroline derivative can be produced using known raw materials and known synthesis methods.

[0511] <Quinolinol-based metal complexes> Quinolinol-based metal complexes are compounds represented by, for example, the following formula (ETM-13). [ka] In the formula, R 1 ~R 6 Each of these elements is independently hydrogen, fluorine, alkyl, cycloalkyl, aralkyl, alkenyl, cyano, alkoxy, or aryl, M is Li, Al, Ga, Be, or Zn, and n is an integer from 1 to 3.

[0512] Specific examples of quinolinol-based metal complexes include 8-quinolinollithium, tris(8-quinolinolate)aluminum, tris(4-methyl-8-quinolinolate)aluminum, tris(5-methyl-8-quinolinolate)aluminum, tris(3,4-dimethyl-8-quinolinolate)aluminum, tris(4,5-dimethyl-8-quinolinolate)aluminum, tris(4,6-dimethyl-8-quinolinolate)aluminum, bis(2-methyl-8-quinolinolate)(phenolate)aluminum, and bis(2-methyl-8-quinolinolate) (2-methylphenolate)aluminum, bis(2-methyl-8-quinolinolate)(3-methylphenolate)aluminum, bis(2-methyl-8-quinolinolate)(4-methylphenolate)aluminum, bis(2-methyl-8-quinolinolate)(2-phenylphenolate)aluminum, bis(2-methyl-8-quinolinolate)(3-phenylphenolate)aluminum, bis(2-methyl-8-quinolinolate)(4-phenylphenolate)aluminum, bis(2-methyl-8-quinolinolate)(2,3 -Dimethylphenolate)aluminum, bis(2-methyl-8-quinolinolate)(2,6-dimethylphenolate)aluminum, bis(2-methyl-8-quinolinolate)(3,4-dimethylphenolate)aluminum, bis(2-methyl-8-quinolinolate)(3,5-dimethylphenolate)aluminum, bis(2-methyl-8-quinolinolate)(3,5-di-t-butylphenolate)aluminum, bis(2-methyl-8-quinolinolate)(2,6-diphenylphenolate)aluminum, bis(2-methyl-8-quinolinolate)(2,6-diphenylphenolate)aluminum, bis(2-methyl-8-quinolinolate) (2,4,6-triphenylphenolate)aluminum, bis(2-methyl-8-quinolinolate)(2,4,6-trimethylphenolate)aluminum, bis(2-methyl-8-quinolinolate)(2,4,5,6-tetramethylphenolate)aluminum, bis(2-methyl-8-quinolinolate)(1-naphtholate)aluminum, bis(2-methyl-8-quinolinolate)(2-naphtholate)aluminum, bis(2,4-dimethyl-8-quinolinolate)(2-phenylphenolate)aluminum, bis(2,4-dimethyl-8-quinolinolate)(3-phenylphenolate)aluminum, bis(2,4-dimethyl-8-quinolinolate)(4-phenylphenolate)aluminum, bis(2,4-dimethyl-8-quinolinolate)(3,5-dimethylphenolate)aluminum, bis(2,4-dimethyl-8-quinolinolate)(3,5-di-t-butylphenolate)aluminum, bis(2-methyl-8-quinolinolate)aluminum-μ-oxo-bis(2-methyl-8-quinolinolate)aluminum, bis(2,4-dimethyl-8-quinolinolate)aluminum-μ-oxo-bis(2,4-dimethyl-8-quinolinolate)aluminum, bis(2-methyl-4-ethyl-8- Examples include aluminum-μ-oxo-bis(2-methyl-4-ethyl-8-quinolinolate)aluminum, bis(2-methyl-4-methoxy-8-quinolinolate)aluminum-μ-oxo-bis(2-methyl-4-methoxy-8-quinolinolate)aluminum, bis(2-methyl-5-cyano-8-quinolinolate)aluminum-μ-oxo-bis(2-methyl-5-cyano-8-quinolinolate)aluminum, bis(2-methyl-5-trifluoromethyl-8-quinolinolate)aluminum-μ-oxo-bis(2-methyl-5-trifluoromethyl-8-quinolinolate)aluminum, and bis(10-hydroxybenzo[h]quinoline)beryllium.

[0513] This quinolinol-based metal complex can be produced using known raw materials and known synthesis methods.

[0514] <Thiazole derivatives and benzothiazole derivatives> Thiazole derivatives are compounds represented by the following formula (ETM-14-1), for example. [ka] Benzothiazole derivatives are compounds represented by, for example, the following formula (ETM-14-2). [ka]

[0515] In each formula, φ is an n-valent aryl ring (preferably an n-valent benzene ring, naphthalene ring, anthracene ring, fluorene ring, benzofluorene ring, phenalene ring, phenanthrene ring, or triphenylene ring), and n is an integer from 1 to 4. The "thiazole substituent" and "benzothiazole substituent" are substituents in which the pyridyl in the "pyridine substituent" in formulas (ETM-2), (ETM-2-1), and (ETM-2-2) is replaced with thiazolyl or benzothiazol (* indicates the bond position) as described below, and at least one hydrogen in the thiazole derivative and benzothiazole derivative may be substituted with deuterium.

[0516] [ka]

[0517] φ is further preferably an anthracene ring or a fluorene ring, and the structure in this case can be described by referring to formula (ETM-2-1) or formula (ETM-2-2), where R in each formula 11 ~R 18 The explanation in formula (ETM-2-1) or formula (ETM-2-2) can be cited. Also, although formula (ETM-2-1) or formula (ETM-2-2) is explained in a form in which two pyridine substituents are bonded, when replacing these with thiazole substituents (or benzothiazole substituents), both pyridine substituents may be replaced with thiazole substituents (or benzothiazole substituents) (i.e., n=2), or one of the pyridine substituents may be replaced with a thiazole substituent (or benzothiazole substituent) and the other pyridine substituent may be R 11 ~R 18 It can also be replaced with (i.e., n=1). Furthermore, for example, R in equation (ETM-2-1) 11 ~R 18 Replace at least one of the "pyridine substituents" with a thiazole substituent (or benzothiazole substituent) 11 ~R 18You can replace it with this.

[0518] These thiazole derivatives or benzothiazole derivatives can be produced using known raw materials and known synthesis methods.

[0519] <Silole derivatives> Silole derivatives are compounds represented by the following formula (ETM-15), for example. Further details are described in Japanese Patent Publication No. 9-194487. [ka]

[0520] X and Y are, independently, alkyl, cycloalkyl, alkenyl, alkynyl, alkoxy, alkenyloxy, alkynyloxy, aryl, and heteroaryl groups, which may be substituted. For details of these groups, refer to the explanation in formula (4) and further to the explanation in formula (ETM-7-2). Alkenyloxy and alkynyloxy are groups in which the alkyl portion of an alkoxy is replaced by an alkenyl or alkynyl, respectively, and for details of these alkenyl and alkynyl groups, refer to the explanation in formula (ETM-7-2). Furthermore, X and Y, both alkyl groups, may be bonded together to form a ring.

[0521] R 1 ~R 4Each of these is independently hydrogen, halogen, alkyl, cycloalkyl, alkoxy, aryloxy, amino, alkylcarbonyl, arylcarbonyl, alkoxycarbonyl, aryloxycarbonyl, azo group, alkylcarbonyloxy, arylcarbonyloxy, alkoxycarbonyloxy, aryloxycarbonyloxy, sulfinyl, sulfonyl, sulfanyl, silyl, carbamoyl, aryl, heteroaryl, alkenyl, alkynyl, nitro, formyl, nitroso, formyloxy, isocyano, cyanate group, isocyanate group, thiocyanate group, isothiocyanate group, or cyano, which may be substituted with alkyl, cycloalkyl, aryl, or halogen, and may form a condensed ring with an adjacent substituent.

[0522] R 1 ~R 4 For details on halogens, alkyls, cycloalkyls, alkoxys, aryloxys, aminos, aryls, heteroaryls, alkenyls, and alkynyls in formula (4), refer to the explanation in formula (4).

[0523] R 1 ~R 4 Details regarding the alkyl, aryl, and alkoxy elements in alkylcarbonyl, arylcarbonyl, alkoxycarbonyl, aryloxy, arylcarbonyloxy, alkoxycarbonyloxy, and aryloxycarbonyloxy can also be found in the explanation in formula (4).

[0524] Examples of silyls include a silyl group and a group in which at least one of the three hydrogen atoms of the silyl group is independently substituted with an aryl, alkyl, or cycloalkyl group. Trisubstituted silyls are preferred, and examples include triarylsilyls, trialkylsilyls, tricycloalkylsilyls, dialkylcycloalkylsilyls, and alkyldicycloalkylsilyls. Details of the aryl, alkyl, and cycloalkyl groups in these can be found in the explanation in formula (4).

[0525] The fused ring formed between adjacent substituents is, for example, R 1 and R 2 , R 2 and R 3 , R 3 and R 4 These are conjugated or unconjugated fused rings formed between such rings. These fused rings may contain nitrogen, oxygen, and sulfur atoms in their intraring structure, or they may be further fused with other rings.

[0526] However, preferably, R 1 and R 4 If is phenyl, then X and Y are not alkyl or phenyl. Also, preferably R 1 and R 4 If is thienyl, then X and Y are alkyl, R 2 and R 3 is alkyl, aryl, alkenyl or R 2 and R 3 It is a structure that does not simultaneously satisfy the requirement of a cycloalkyl group that is bonded to form a ring. Furthermore, preferably, R 1 and R 4 If R is a silyl group, 2 , R 3 X and Y are, independently, not hydrogen or an alkyl group having 1 to 6 carbon atoms. Also, preferably, R 1 and R 2 In the case of a structure in which a benzene ring is fused, X and Y are not alkyl and phenyl.

[0527] These silole derivatives can be produced using known raw materials and known synthesis methods.

[0528] <Azoline derivatives> Azoline derivatives are compounds represented by formula (ETM-16) below, for example. Further details are described in International Publication No. 2017 / 014226. [ka]

[0529] In formula (ETM-16), φ is an m-valent group derived from an aromatic hydrocarbon having 6 to 40 carbon atoms or an m-valent group derived from an aromatic heterocycle having 2 to 40 carbon atoms, and at least one hydrogen atom of φ may be substituted with an alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 3 to 14 carbon atoms, an aryl group having 6 to 18 carbon atoms, or a heteroaryl group having 2 to 18 carbon atoms. Y is independently -O-, -S-, or >N-Ar, where Ar is a C6-C12 aryl or C2-C12 heteroaryl, and at least one hydrogen of Ar may be substituted with a C1-C4 alkyl, a C5-C10 cycloalkyl, a C6-C12 aryl, or a C2-C12 heteroaryl, R 1 ~R 5 Each of these is independently hydrogen, an alkyl group having 1 to 4 carbon atoms, or a cycloalkyl group having 5 to 10 carbon atoms, provided that Ar and R in >N-Ar are different. 1 ~R 5 One of these is a site that binds to L, L is independently selected from the group consisting of a divalent group represented by the following formula (L-1) and a divalent group represented by the following formula (L-2). [ka]

[0530] In formula (L-1), X 1 ~X 6 Each of them is independent of =CR 6 - or = N- and X 1 ~X 6 At least two of them are =CR 6 - and X 1 ~X 6 Two of the =CR 6 -R in 6 The φ or azoline ring is the site that binds to the ring, while the others are =CR. 6 -R in 6 It is hydrogen, In formula (L-2), X 7 ~X 14Each of them is independent of =CR 6 - or = N- and X 7 ~X 14 At least two of them are =CR 6 - and X 7 ~X 14 Two of the =CR 6 -R in 6 The φ or azoline ring is the site that binds to the ring, while the others are =CR. 6 -R in 6 It is hydrogen, At least one hydrogen atom of L may be substituted with an alkyl group having 1 to 4 carbon atoms, a cycloalkyl group having 5 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, or a heteroaryl group having 2 to 10 carbon atoms. m is an integer from 1 to 4, and when m is from 2 to 4, the groups formed by the azoline ring and L may be the same or different, and At least one hydrogen atom in the compound represented by formula (ETM-16) may be substituted with deuterium.

[0531] Specific azoline derivatives are compounds represented by the following formulas (ETM-16-1) or (ETM-16-2). [ka]

[0532] In equations (ETM-16-1) and (ETM-16-2), φ is an m-valent group derived from an aromatic hydrocarbon having 6 to 40 carbon atoms or an m-valent group derived from an aromatic heterocycle having 2 to 40 carbon atoms, and at least one hydrogen atom of φ may be substituted with an alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 3 to 14 carbon atoms, an aryl group having 6 to 18 carbon atoms, or a heteroaryl group having 2 to 18 carbon atoms. In formula (ETM-16-1), Y is independently -O-, -S-, or >N-Ar, where Ar is a C6-C12 aryl or C2-C12 heteroaryl, and at least one hydrogen atom of Ar may be substituted with a C1-C4 alkyl, a C5-C10 cycloalkyl, a C6-C12 aryl, or a C2-C12 heteroaryl. In formula (ETM-16-1), R 1 ~R 4 Each of these is independently hydrogen, an alkyl group having 1 to 4 carbon atoms, or a cycloalkyl group having 5 to 10 carbon atoms, where R 1 and R 2 They are identical, and R 3 and R 4 They are identical, In formula (ETM-16-2), R 1 ~R 5 Each of these is independently hydrogen, an alkyl group having 1 to 4 carbon atoms, or a cycloalkyl group having 5 to 10 carbon atoms, where R 1 and R 2 They are identical, and R 3 and R 4 They are identical, In equations (ETM-16-1) and (ETM-16-2), L is independently selected from the group consisting of a divalent group represented by the following formula (L-1) and a divalent group represented by the following formula (L-2).

[0533] [ka]

[0534] In formula (L-1), X 1 ~X 6 Each of them is independent of =CR 6 - or = N- and X 1 ~X 6 At least two of them are =CR 6 - and X 1 ~X 6 Two of the =CR 6 -R in 6The φ or azoline ring is the site that binds to the ring, while the others are =CR. 6 -R in 6 It is hydrogen, In formula (L-2), X 7 ~X 14 Each of them is independent of =CR 6 - or = N- and X 7 ~X 14 At least two of them are =CR 6 - and X 7 ~X 14 Two of the =CR 6 -R in 6 The φ or azoline ring is the site that binds to the ring, while the others are =CR. 6 -R in 6 It is hydrogen, At least one hydrogen atom of L may be substituted with an alkyl group having 1 to 4 carbon atoms, a cycloalkyl group having 5 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, or a heteroaryl group having 2 to 10 carbon atoms. m is an integer from 1 to 4, and when m is from 2 to 4, the groups formed by the azoline ring and L may be the same or different, and At least one hydrogen atom in the compound represented by formula (ETM-16-1) or formula (ETM-16-2) may be substituted with deuterium.

[0535] Preferably, φ is selected from the group consisting of a monovalent group represented by formulas (φ1-1) to (φ1-18), a divalent group represented by formulas (φ2-1) to (φ2-34), a trivalent group represented by formulas (φ3-1) to (φ3-3), and a tetravalent group represented by formulas (φ4-1) to (φ4-2), and at least one hydrogen atom of φ may be substituted with an alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 3 to 14 carbon atoms, an aryl group having 6 to 18 carbon atoms, or a heteroaryl group having 2 to 18 carbon atoms.

[0536] [ka]

[0537] [ka] [ka]

[0538] In the formulas, Z is >CR2, >N-Ar, >NL, -O-, or -S-, where R in >CR2 is independently an alkyl group having 1 to 4 carbon atoms, a cycloalkyl group having 5 to 10 carbon atoms, an aryl group having 6 to 12 carbon atoms, or a heteroaryl group having 2 to 12 carbon atoms, and R may be bonded to each other to form a ring, where Ar in >N-Ar is an aryl group having 6 to 12 carbon atoms or a heteroaryl group having 2 to 12 carbon atoms, and where L in >NL is L in formula (ETM-16), formula (ETM-16-1), or formula (ETM-16-2). The asterisk (*) in the formulas indicates a bond position.

[0539] Preferably, L is a divalent ring group selected from the group consisting of benzene, naphthalene, pyridine, pyrazine, pyrimidine, pyridazine, triazine, quinoline, isoquinoline, naphthyridine, phthalazine, quinoxaline, quinazoline, sinnoline, and pteridine, and at least one hydrogen of L may be substituted with a C1-C4 alkyl, a C5-C10 cycloalkyl, a C6-C10 aryl, or a C2-C10 heteroaryl.

[0540] Preferably, in >N-Ar as Y or Z, Ar is selected from the group consisting of phenyl, naphthyl, pyridinyl, pyrazinyl, pyrimidinyl, pyridadinyl, triazinyl, quinolinyl, isoquinolinyl, naphthyridinyl, phthalazinyl, quinoxalinyl, quinazolinyl, synnolinyl, and pteridinyl, and at least one hydrogen of Ar in >N-Ar as Y may be substituted with a C1-C4 alkyl, a C5-C10 cycloalkyl, or a C6-C10 aryl.

[0541] Preferably, R 1 ~R 4Each of these is independently hydrogen, an alkyl group having 1 to 4 carbon atoms, or a cycloalkyl group having 5 to 10 carbon atoms, where R 1 and R 2 They are identical, R 3 and R 4 They are identical, and R 1 ~R 4 Not all of them become hydrogen at the same time, and m is either 1 or 2. When m is 2, the group formed by the azoline ring and L is the same.

[0542] Specific examples of azoline derivatives include the following compounds. Note that "Me" in the structural formula represents methyl. [ka]

[0543] More preferably, φ is selected from the group consisting of divalent groups represented by the following formulas (φ2-1), (φ2-31), (φ2-32), (φ2-33), and (φ2-34), and at least one hydrogen of φ may be substituted with an aryl group having 6 to 18 carbon atoms. In the following formulas, * indicates the bond position.

[0544] [ka]

[0545] L is a divalent ring group selected from the group consisting of benzene, pyridine, pyrazine, pyrimidine, pyridazine, and triazine, and at least one hydrogen of L may be substituted with an alkyl group having 1 to 4 carbon atoms, a cycloalkyl group having 5 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, or a heteroaryl group having 2 to 14 carbon atoms. In >N-Ar as Y, Ar is selected from the group consisting of phenyl, pyridinyl, pyrazinyl, pyrimidinyl, pyridazinyl, and triazinyl, and at least one hydrogen of said Ar may be substituted with an alkyl group having 1 to 4 carbon atoms, a cycloalkyl group having 5 to 10 carbon atoms, or an aryl group having 6 to 10 carbon atoms. R 1~R 4 Each of these is independently hydrogen, an alkyl group having 1 to 4 carbon atoms, or a cycloalkyl group having 5 to 10 carbon atoms, where R 1 and R 2 They are identical, R 3 and R 4 They are identical, and R 1 ~R 4 Not all of them will turn into hydrogen at the same time, and, m is 2, and the group formed by the azoline ring and L is the same.

[0546] Other specific examples of azoline derivatives include the following compounds. Note that "Me" in the structural formula represents methyl. [ka]

[0547] For details regarding the alkyl, cycloalkyl, aryl, or heteroaryl elements in each of the above formulas defining this azoline derivative, refer to the explanation in formula (4).

[0548] This azoline derivative can be produced using known raw materials and known synthesis methods.

[0549] <Reducing substances> 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.

[0550] 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.

[0551] The electron injection layer material and electron transport layer material described above can also be used as electron layer material as polymer compounds obtained by polymerizing reactive compounds in which reactive substituents are substituted as monomers, or as polymer crosslinks thereof, or as pendant-type polymer compounds obtained by reacting a main-chain polymer with the reactive compound, or as pendant-type polymer crosslinks thereof. In this case, the explanation for the polycyclic aromatic compound represented by formula (4) can be referenced for the reactive substituent. Details of the applications of such polymer compounds and polymer crosslinks will be described later.

[0552] 3-1-7. 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.

[0553] 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.

[0554] 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.

[0555] 3-1-8. Binding agents that may be used in each layer The materials used in the hole injection layer, hole transport layer, light emission layer, electron transport layer, and electron injection layer described above can form each layer individually, but they can also be dispersed in solvent-soluble resins such as polyvinyl chloride, polycarbonate, polystyrene, poly(N-vinylcarbazole), polymethyl methacrylate, polybutyl methacrylate, polyester, polysulfone, polyphenylene oxide, polybutadiene, hydrocarbon resins, ketone resins, phenoxy resins, polyamides, ethylcellulose, vinyl acetate resins, ABS resins, and polyurethane resins, or in curable resins such as phenolic resins, xylene resins, petroleum resins, urea resins, melamine resins, unsaturated polyester resins, alkyd resins, epoxy resins, and silicone resins as polymer binders.

[0556] 3-1-9. 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.

[0557] 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.

[0558] 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.

[0559] <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.

[0560] <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.

[0561] 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 crosslinking substituent (also called a crosslinking 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 spray printing.

[0562] As an example, referring to Figure 4, a method for forming a coating film on a substrate having banks using an inkjet method will be explained. First, the banks (200) are provided on electrodes (120) on a substrate (110). In this case, ink droplets (310) are dropped from an inkjet head (300) between the banks (200) and dried to create a coating film (130). This process is repeated to create the next coating film (140), and then the light-emitting layer (150). By using a vacuum deposition method to deposit electron transport layers, electron injection layers, and electrodes, an organic EL element with light-emitting areas separated by bank material can be fabricated.

[0563] Drying processes include methods such as air drying, heating, and vacuum drying. The drying process may be performed only once, or multiple times using different methods and conditions. Furthermore, different methods may be combined, such as firing under reduced pressure.

[0564] 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.

[0565] 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.

[0566] 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.

[0567] For example, the procedure for fabricating an organic EL element by partially applying a wet film deposition method is shown below. (Step 1) Deposition of film by vacuum deposition of anode (Step 2) Wet deposition of a hole injection layer-forming composition containing hole injection layer material. (Step 3) Wet deposition of a hole transport layer forming composition containing a hole transport layer material. (Step 4) Wet deposition of a light-emitting layer-forming composition containing a host material and a dopant material. (Step 5) Deposition of electron transport layer by vacuum deposition (Step 6) Deposition of electron injection layer by vacuum deposition (Step 7) Deposition of film by vacuum deposition of cathode By following this procedure, an organic EL element is obtained consisting of an anode, a hole injection layer, a hole transport layer, an emissive layer made of a host material and a dopant material, an electron transport layer, an electron injection layer, and a cathode. Of course, the electron transport layer and electron injection layer may also be formed by a wet deposition method using a layer-forming composition containing the electron transport layer material and the electron injection layer material, respectively. In this case, it is preferable to use means to prevent the dissolution of the lower light-emitting layer, or to deposit the film from the cathode side, in the opposite direction to the procedure described above.

[0568] <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.

[0569] <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.

[0570] 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.

[0571] Materials used in the bank include, but are not limited to, polysaccharides and their derivatives, homopolymers and copolymers of ethylenic monomers having hydroxyls, biopolymers, polyacryloyl compounds, polyesters, polystyrene, polyimides, polyamideimides, polyetherimides, polysulfides, polysulfones, polyphenylenes, polyphenyl ethers, polyurethanes, epoxy (meth)acrylates, melamine (meth)acrylates, polyolefins, cyclic polyolefins, acrylonitrile-butadiene-styrene copolymers (ABS), silicone resins, polyvinyl chloride, chlorinated polyethylene, chlorinated polypropylene, polyacetates, polynorbornene, synthetic rubber, fluorinated polymers such as polyfluorovinylidene, polytetrafluoroethylene, and polyhexafluoropropylene, fluoroolefin-hydrocarbonolefin copolymers, and fluorocarbon polymers.

[0572] <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.

[0573] <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.

[0574] (1) Physical properties of organic solvents The boiling point of at least one organic solvent is 130°C to 300°C, more preferably 140°C to 270°C, and even more preferably 150°C to 250°C. A boiling point higher than 130°C is preferable from the viewpoint of inkjet ejection performance. A boiling point lower than 300°C is preferable from the viewpoint of coating film defects, surface roughness, residual solvent, and smoothness. From the viewpoint of good inkjet ejection performance, film formation, smoothness, and low residual solvent, a composition containing two or more organic solvents is more preferable. On the other hand, depending on the circumstances, the composition may be in a solid state by removing the solvent from the organic layer-forming composition, taking into consideration transportability, etc.

[0575] Furthermore, the organic solvent contains a good solvent (GS) and a poor solvent (PS) for at least one of the solutes, and the boiling point (BP) of the good solvent (GS) GS ) is the boiling point (BP) of a poor solvent (PS) PS A configuration that is lower than ) is particularly preferable. By adding a high-boiling-point poor solvent, the low-boiling-point good solvent evaporates first during film formation, increasing the concentration of the constituent substances and the poor solvent in the composition, thus promoting rapid film formation. As a result, a coating film with fewer defects, low surface roughness, and high smoothness can be obtained.

[0576] Difference in solubility (S GS -S PS The difference in boiling points (BP) is preferably 1% or more, more preferably 3% or more, and even more preferably 5% or more. PS -BP GS The temperature is preferably 10°C or higher, more preferably 30°C or higher, and even more preferably 50°C or higher.

[0577] 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.

[0578] (2) Specific examples of organic solvents Organic solvents used in compositions for forming organic layers include 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. Specific examples include pentanol, hexanol, heptanol, octanol, nonanol, decanol, undecanol, dodecanol, tetradecanol, hexane-2-ol, heptan-2-ol, octan-2-ol, decane-2-ol, dodecane-2-ol, and cyclohexanol. Sanol, α-terpineol, β-terpineol, γ-terpineol, δ-terpineol, terpineol (mixture), ethylene glycol monomethyl ether acetate, propylene glycol monomethyl ether acetate, diethylene glycol dimethyl ether, dipropylene glycol dimethyl ether, diethylene glycol ethyl methyl ether, diethylene glycol isopropyl methyl ether, dipropylene glycol monomethyl ether, diethylene glycol diethyl ether, diethylene glycol monomethyl ether , diethylene glycol butyl methyl ether, tripropylene glycol dimethyl ether, triethylene glycol dimethyl ether, diethylene glycol monobutyl ether, ethylene glycol monophenyl ether, triethylene glycol monomethyl ether, diethylene glycol dibutyl ether, triethylene glycol butyl methyl ether, polyethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, p-xylene, m-xylene, o-xylene, 2,6-lutidine, 2-fluoro-m-xylene, 3-fluoro-o-xylene, 2-chlorobenzo trifluoride, cumene, toluene, 2-chloro-6-fluorotoluene, 2-fluoroanisole, anisole, 2,3-dimethylpyrazine, bromobenzene, 4-fluoroanisole, 3-fluoroanisole, 3-trifluoromethylanisole, mesitylene, 1,2,4-trimethylbenzene, t-butylbenzene, 2-methylanisole, phenethole, benzodioxole, 4-methylanisole, s-butylbenzene, 3-methylanisole, 4-fluoro-3-methylanisole, cymene, 1,2,3-trimethylbenzene, 1,2-dichlorobenzene, 2-fluorobenzonitrile, 4-fluoroveratrol, 2,6-dimethylanisole, n-butylbenzene, 3-fluorobenzonitrile, decalin (decahydronaphthalene), neopentylbenzene, 2,5-dimethylanisole, 2,4-dimethylanisole, benzonitrile, 3,5-dimethylanisole, diphenyl ether, 1-fluoro-3,5-dimethoxybenzene, methyl benzoate, isopentylbenzene, 3,4-dimethylanisole, o-tolunitrile, n-amylbenzene, veratrol, 1,2,3,4-tetrahydronaphthalene, ethyl benzoate, n-hexylbenzene, propyl benzoate, cyclohexylbenzene, 1- Examples of solvents include, but are not limited to, thylnaphthalene, butyl benzoate, 2-methylbiphenyl, 3-phenoxytoluene, 2,2'-vitrill, dodecylbenzene, dipentylbenzene, tetramethylbenzene, trimethoxybenzene, trimethoxytoluene, 2,3-dihydrobenzofuran, 1-methyl-4-(propoxymethyl)benzene, 1-methyl-4-(butyloxymethyl)benzene, 1-methyl-4-(pentyloxymethyl)benzene, 1-methyl-4-(hexyloxymethyl)benzene, 1-methyl-4-(heptyloxymethyl)benzene, benzyl butyl ether, benzylpentyl ether, benzylhexyl ether, benzylheptyl ether, and benzyloctyl ether. Furthermore, the solvent may be used individually or in mixtures.

[0579] <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.

[0580] (1) Binder The organic layer-forming composition may contain a binder. The binder forms a film during film formation and also bonds the resulting film to the substrate. It also plays a role in dissolving, dispersing, and binding other components within the organic layer-forming composition.

[0581] Examples of binders used in organic layer-forming compositions include, but are not limited to, acrylic resins, polyethylene terephthalate, ethylene-vinyl acetate copolymers, ethylene-vinyl alcohol copolymers, acrylonitrile-ethylene-styrene copolymer (AES) resins, ionomers, chlorinated polyethers, diallyl phthalate resins, unsaturated polyester resins, polyethylene, polypropylene, polyvinyl chloride, polyvinylidene chloride, polystyrene, polyvinyl acetate, Teflon, acrylonitrile-butadiene-styrene copolymer (ABS) resins, acrylonitrile-styrene copolymer (AS) resins, phenolic resins, epoxy resins, melamine resins, urea resins, alkyd resins, polyurethanes, and copolymers of the above resins and polymers.

[0582] The binder used in the organic layer-forming composition may be a single type or a mixture of multiple types.

[0583] (2) Surfactants The organic layer-forming composition may contain surfactants, for example, to control the uniformity of the film surface, the hydrophilicity and liquid repellency of the film surface. Surfactants are classified into ionic and nonionic based on the structure of their hydrophilic groups, and further classified into alkyl, silicone, and fluorine based on the structure of their hydrophobic groups. They are also classified into monomolecular systems with relatively small molecular weights and simple structures, and polymeric systems with large molecular weights and side chains or branching, based on their molecular structure. Furthermore, they are classified into single systems and mixed systems containing two or more surfactants and a substrate, based on their composition. All types of surfactants can be used in the organic layer-forming composition.

[0584] Examples of surfactants include Polyflow No. 45, Polyflow KL-245, Polyflow No. 75, Polyflow No. 90, Polyflow No. 95 (product name, manufactured by Kyoeisha Chemical Industry Co., Ltd.), Disperbyk 161, Disperbyk 162, Disperbyk 163, Disperbyk 164, Disperbyk 166, Disperbyk 170, Disperbyk 180, Disperbyk 181, Disperbyk 182, BYK300, and BYK. 306, BYK310, BYK320, BYK330, BYK342, BYK344, BYK346 (product name, manufactured by Big Chemie Japan Co., Ltd.), KP-341, KP-358, KP-368, KF-96-50CS, KF-50-100CS (product name, manufactured by Shin-Etsu Chemical Co., Ltd.), Surflon SC-101, Surflon KH-40 (product name, manufactured by Seimi Chemical Co., Ltd.), Futergent 222F, Futergent 251, FTX-218 (product name, manufactured by Neos Co., Ltd.), EFTOP EF-351, EFTOP EF-352, EFTOP EF-601, EFTOP EF-801, EFTOPEF-802 (product name, manufactured by Mitsubishi Materials Corporation), Megafac F-470, Megafac F-471, Megafac F-475, Megafac R-08, Megafac F-477, Megafac F-479, Megafac F-553, Megafac F-554 (product name, manufactured by DIC Corporation), fluoroalkylbenzene sulfonate, fluoroalkyl carboxylate, fluoroalkyl polyoxyethylene ether, fluoroalkylammonium iodide, fluoroalkyl betaine, fluoroalkyl sulfonate, diglycerin tetrakis(fluoroalkyl polyoxyethylene ether), fluoroalkyltrimethylammonium salt, fluoroalkylaminosulfonate, polyoxyethylene noni Examples include tetraphenyl ether, polyoxyethylene octylphenyl ether, polyoxyethylene alkyl ether, polyoxyethylene laurate, polyoxyethylene oleate, polyoxyethylene stearate, polyoxyethylene laurylamine, sorbitan laurate, sorbitan palmitate, sorbitan stearate, sorbitan oleate, sorbitan fatty acid ester, polyoxyethylene sorbitan laurate, polyoxyethylene sorbitan palmitate, polyoxyethylene sorbitan stearate, polyoxyethylene sorbitan oleate, polyoxyethylene naphthyl ether, alkylbenzene sulfonate, and alkyldiphenyl ether disulfonate.

[0585] Furthermore, a single surfactant may be used, or two or more may be used in combination.

[0586] <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 properties 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. For example, in the case of a light-emitting layer-forming composition, it is preferable that the first component is present in an amount of 0.0001% to 2.0% by mass of the total mass of the light-emitting layer-forming composition, the second component in an amount of 0.0999% to 8.0% by mass of the total mass of the light-emitting layer-forming composition, and the third component in an amount of 90.0% to 99.9% by mass of the total mass of the light-emitting layer-forming composition.

[0587] More preferably, the first component is present in an amount of 0.005% to 1.0% by mass relative to the total mass of the light-emitting layer forming composition, the second component in an amount of 0.095% to 4.0% by mass relative to the total mass of the light-emitting layer forming composition, and the third component in an amount of 95.0% to 99.9% by mass relative to the total mass of the light-emitting layer forming composition. Even more preferably, the first component is present in an amount of 0.05% to 0.5% by mass relative to the total mass of the light-emitting layer forming composition, the second component in an amount of 0.25% to 2.5% by mass relative to the total mass of the light-emitting layer forming composition, and the third component in an amount of 97.0% to 99.7% by mass relative to the total mass of the light-emitting layer forming composition.

[0588] 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.

[0589] Regarding the viscosity of the organic layer-forming composition, a higher viscosity results in better film formation and good ejection when using an inkjet method. On the other hand, a lower viscosity makes it easier to form thin films. For this reason, the viscosity of the organic layer-forming composition is preferably 0.3 to 3 mPa·s at 25°C, and more preferably 1 to 3 mPa·s. In this invention, viscosity is a value measured using a cone-plate type rotational viscometer.

[0590] A lower surface tension in the organic layer-forming composition results in better film formation and a defect-free coating. On the other hand, a higher surface tension results in better inkjet ejection performance. For this reason, the organic layer-forming composition preferably has a surface tension of 20 to 40 mN / m at 25°C, and more preferably 20 to 30 mN / m. In this invention, the surface tension is a value measured using the suspension drop method.

[0591] <Cross-linkable polymer compounds: Compounds represented by formula (XLP-1)> Next, we will explain the case where the above-mentioned polymer compound has a crosslinkable substituent. Such a crosslinkable polymer compound is, for example, a compound represented by the following formula (XLP-1).

[0592] [ka]

[0593] In equation (XLP-1), MUx, ECx, and k are defined the same as MU, EC, and k in formula (H3), provided that the compound represented by formula (XLP-1) has at least one crosslinkable substituent (XLS), and preferably the content of a monovalent or divalent aromatic group having a crosslinkable substituent is 0.1 to 80% by mass of the molecule.

[0594] The content of monovalent or divalent aromatic compound groups having crosslinkable substituents is preferably 0.5 to 50% by mass, and more preferably 1 to 20% by mass, in the molecule.

[0595] The crosslinkable substituent (XLS) is not particularly limited as long as it is a group that can further crosslink the polymer compound described above, but substituents with the following structures are preferred. The asterisk (*) in each structural formula indicates the bond position. [ka]

[0596] L is independently a single bond, -O-, -S-, >C=O, -OC(=O)-, a C1-C12 alkylene, a C1-C12 oxyalkylene, and a C1-C12 polyoxyalkylene. Among the above substituents, groups represented by formula (XLS-1), (XLS-2), (XLS-3), (XLS-9), (XLS-10), or (XLS-17) are preferred, and groups represented by formula (XLS-1), (XLS-3), or (XLS-17) are more preferred.

[0597] Examples of divalent aromatic compounds having crosslinkable substituents include compounds having the following substructures. [ka]

[0598] [ka]

[0599] [ka]

[0600] [ka]

[0601] <Method for producing polymer compounds and crosslinked polymer compounds> Methods for producing polymer compounds and crosslinkable polymer compounds will be explained using the compounds represented by formula (H3) and (XLP-1) described above as examples. These compounds can be synthesized by appropriately combining known production methods.

[0602] Solvents used in the reaction include aromatic solvents, saturated / unsaturated hydrocarbon solvents, alcohol solvents, and ether-based solvents, such as dimethoxyethane, 2-(2-methoxyethoxy)ethane, and 2-(2-ethoxyethoxy)ethane.

[0603] The reaction may also be carried out in a two-phase system. If the reaction is carried out in a two-phase system, a phase transfer catalyst such as a quaternary ammonium salt may be added as needed.

[0604] The compounds of formula (H3) and (XLP-1) can be produced in a single step or in multiple steps. Furthermore, the polymerization can be carried out by a batch polymerization method, where all the raw materials are placed in the reaction vessel before the reaction begins; by a dropwise polymerization method, where the raw materials are added dropwise to the reaction vessel; or by a precipitation polymerization method, where the product precipitates as the reaction progresses. These methods can be combined as appropriate. For example, when synthesizing the compound represented by formula (H3) in a single step, the target product is obtained by adding monomers with polymerizable groups attached to monomer units (MU) and monomers with polymerizable groups attached to end-cap units (EC) to the reaction vessel and carrying out the reaction. Alternatively, when synthesizing the compound represented by formula (H3) in multiple steps, the target product is obtained by polymerizing monomers with polymerizable groups attached to monomer units (MU) to the desired molecular weight, and then adding monomers with polymerizable groups attached to end-cap units (EC) and reacting them. By adding monomers with polymerizable groups attached to different types of monomer units (MU) in multiple steps and carrying out the reaction, polymers with a concentration gradient in the monomer unit structure can be produced. Furthermore, after preparing a precursor polymer, the target polymer can be obtained by a subsequent reaction.

[0605] Furthermore, the primary structure of the polymer can be controlled by selecting the polymerizable groups of the monomer. For example, as shown in synthesis schemes 1 to 3, it is possible to synthesize polymers with random primary structures (synthesis scheme 1), polymers with regular primary structures (synthesis schemes 2 and 3), and these can be used in appropriate combinations depending on the desired product. Moreover, by using monomers with three or more polymerizable groups, hyperbranched polymers and dendrimers can be synthesized.

[0606] [ka]

[0607] Monomers that can be used in the present invention can be synthesized in accordance with the methods described in Japanese Patent Publication No. 2010-189630, International Publication No. 2012 / 086671, International Publication No. 2013 / 191088, International Publication No. 2002 / 045184, International Publication No. 2011 / 049241, International Publication No. 2013 / 146806, International Publication No. 2005 / 049546, International Publication No. 2015 / 145871, Japanese Patent Publication No. 2010-215886, Japanese Patent Publication No. 2008-106241, International Publication No. 2016 / 031639, and Japanese Patent Publication No. 2011-174062.

[0608] Furthermore, specific polymer synthesis procedures can be described in accordance with the methods described in Japanese Patent Publication No. 2012-036388, International Publication No. 2015 / 008851, Japanese Patent Publication No. 2012-36381, Japanese Patent Publication No. 2012-144722, International Publication No. 2015 / 194448, International Publication No. 2013 / 146806, International Publication No. 2015 / 145871, International Publication No. 2016 / 031639, International Publication No. 2016 / 125560, and International Publication No. 2011 / 049241.

[0609] 3-1-10. Application Examples of Organic Electroluminescent Devices Furthermore, the present invention can also be applied to display devices equipped with organic EL elements or lighting devices equipped with organic EL elements. A display device or lighting device equipped with an organic EL element can be manufactured by known methods, such as connecting the organic EL element according to this embodiment with a known driving device, and can be driven using known driving methods such as DC driving, pulse driving, or AC driving as appropriate.

[0610] 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 / or segment displays. Matrix and segment displays may coexist on the same panel.

[0611] 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.

[0612] 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.

[0613] 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.

[0614] 3-2. Other Organic Devices The polycyclic aromatic compounds according to the present invention can be used not only in the organic field-light-emitting device described above, but also in the fabrication of organic field-effect transistors or organic thin-film solar cells.

[0615] 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.

[0616] 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.

[0617] 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.

[0618] 4. 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.

[0619] 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 and light-emitting elements that generate ultraviolet light or shorter wavelength blue light can be converted into blue or green light with high 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.

[0620] 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.

[0621] 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]

[0622] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. In each formula in the examples, Me is methyl, Et is ethyl, i Pr stands for isopropyl, tBu for t-butyl, and Bpin for pinacolate boryl. First, examples of the synthesis of polycyclic aromatic compounds are described below.

[0623] Synthesis example (1): Synthesis of compound (v-4001) To a flask containing compound (Int-v-4001) (2.43 g, 3.0 mmol, 1 eq.) and o-dichlorobenzene (400 ml), boron tribromide (4.52 ml, 48 mmol, 16 eq.) was added under a nitrogen atmosphere at room temperature. After the addition was complete, the temperature was raised to 180°C and the mixture was stirred for 20 hours. Then, it was cooled back to room temperature, and N,N-diisopropylethylamine (15.40 ml, 90 mmol, 30 eq.) was added, and the mixture was stirred until the exothermic reaction subsided. The reaction solution was then removed by distillation at 60°C under reduced pressure to obtain the crude product. The crude product was washed with acetonitrile, methanol, and toluene in that order, purified by silica gel column (eluent: toluene), and the crude product was recrystallized twice with o-dichlorobenzene to obtain compound (v-4001) (0.25 g). The target compound (v-4001) was identified at m / z = 818.3824 by LC-MS.

[0624] [ka]

[0625] Synthesis example (2): Synthesis of compound (v-4010)

[0626] Compound (Int-v-4010) (0.106 g, 0.10 mmol, 1 eq.), boron triiodide (0.157 g, 0.40 mmol, 4 eq.), 2,6-tert-butylpyridine (0.067 ml, 0.30 mmol), and chlorobenzene (1.0 ml) were placed in a flask and stirred at room temperature under a nitrogen atmosphere for 20 hours. Heating was stopped, water was added to the reaction mixture at 0°C, and the mixture was extracted with dichloromethane. The mixture was then purified using a silica gel column (eluent: hexane / dichloromethane = 3 / 1), and the crude product was washed with acetonitrile and hexane to obtain compound (v-4010) (0.008 g).

[0627] [ka]

[0628] The target compound (v-4010) was identified by NMR measurement and MS. 1 H-NMR(400MHz,CDCl3):δ = 1.41(s,3H),1.56(s,6H),1.86(s,6H),2.12(s,6H),2.20(s,6H),2.25 (s,3H),2.30(s,6H),2.40(m,9H),2.46(s,3H),5.15(s,1H),6.20(d,J = 7.8 Hz,1H),6.25(s,1H),6.42(s,1H),6.43(s,1H),6.71-6.79(m,6H),6.85(d,J = 7.8 Hz,1H),6.92-6.97(m,5H),7.10-7.14(m,3H),7.18(d,J = 7.3 HRMS MALDI-TOF / MS:m / z[M] + calcd for C 76 H 72 B2N41062.5960,observed 1062.5951.

[0629] Synthesis example (3): Synthesis of compound (v-10054)

[0630] Under a nitrogen atmosphere, a Schlenk tube containing compound (Int-v-10054) (0.121 g, 0.10 mmol), boron triiodide (0.157 g, 0.20 mmol), 2,6-di-tert-butylpyridine (0.130 ml, 0.60 mmol), and toluene (1.0 ml) was stirred at 0 °C for 5 hours. Then, phosphate buffer solution (pH=6.8, 10 ml) was added to the reaction mixture, the aqueous layer was separated, and extracted with dichloromethane. The resulting crude product was then subjected to a silica gel short pass (developing solvent: hexane / toluene = 1 / 1 and ethyl acetate). The fraction containing the target product was concentrated, and the solid was washed with hexane (20 ml). Furthermore, the fraction containing the target compound was separated using gel permeation chromatography (GPC) (eluent: dichloroethane), and then the target compound (v-10054) was obtained as a yellow solid (19.3 mg) by silica gel short pass chromatography (eluent: hexane / toluene = 1 / 1).

[0631] [ka]

[0632] The structure of compound (v-10054) was confirmed by NMR measurement. 1 H-NMR (500MHz, CDCl3): δ = 1.23(s,9H),1.45(s,9H),5.91(s,1H),6.67(s,2H),6.73(d,J = 8.6 Hz,1H),6.89-7.02(m,10H),7.09-7.30(m,27H),7.40-7.43(m,4H),7.50(t,J = 7.7 Hz,2H),8.26(s,1H),8.48(d,J = 8.0 Hz,1H),8.69(d,J = 7.4 Hz,1H),8.76(d,J = 8.0 Hz,1H),8.81(d,J = 8.6 Hz,1H);HRMS MALDI-TOF / MS: m / z[M] + calcd for C 86 H 67 B3N61208.586, observed 1208.585.

[0633] Synthesis example (4): Synthesis of compound (v-10129) [ka]

[0634] The compound (Int-v-10054) was replaced with compound (Int-v-10129), and the solvent was changed from toluene to o-dichlorobenzene, except that the compound was synthesized in the same manner as in synthesis example (3). MALDI-TOF-MS(M + ) = 1232.584

[0635] Synthesis example (5): Synthesis of compound (v-10130) [ka]

[0636] The compound was synthesized in the same manner as in synthesis example (3), except that compound (Int-v-10054) was replaced with compound (Int-v-10130) and the solvent was changed from toluene to o-dichlorobenzene. MALDI-TOF-MS(M + ) = 1286.663

[0637] Synthesis example (6): Synthesis of compound (v-10080) [ka]

[0638] To a flask containing compound (Int-v-10080) (1.2 g) and tert-butylbenzene (7.0 ml), 2.2 ml of 1.6 M tert-butyllithium pentane solution was added under a nitrogen atmosphere at -30°C. After the addition was complete, the temperature was raised to 60°C and stirred for 2 hours, then components with a lower boiling point than tert-butylbenzene were removed by distillation under reduced pressure. The mixture was cooled to -30°C, boron tribromide (0.7 g) was added, and the temperature was raised to room temperature and stirred for 0.5 hours. Then, it was cooled again to 0°C, N,N-diisopropylethylamine (0.40 ml) was added, and the mixture was stirred at room temperature until the exothermic reaction subsided, then the temperature was raised to 120°C and heated and stirred for 2 hours. The reaction mixture was cooled to room temperature, and then liquid-liquid was added to aqueous sodium acetate solution cooled in an ice bath, followed by heptane. Next, the compound was purified using a silica gel short-pass column (additional solution: toluene), and the solvent was removed by reduced pressure distillation. The resulting solid was dissolved in toluene, and heptane was added to reprecipitate it, yielding compound (v-10080) (0.01 g). MALDI-TOF-MS(M + ) = 1070.656

[0639] Synthesis example (7): Synthesis of compound (v-10113) [ka]

[0640] Under a nitrogen atmosphere, a Schlenk flask containing compound (Int-v-10113) (0.131 g, 0.10 mmol), boron triiodide (0.078 g, 0.2 mmol), 2,6-di-tert-butylpyridine (0.054 ml, 0.25 mmol), and chlorobenzene (1.0 ml) was stirred at 50°C for 24 hours. Subsequently, phosphate buffer solution (pH = 6.8, 10 ml) was added to the reaction mixture at 0°C, the aqueous layer was separated, and extracted with dichloromethane (20 ml, 3 times). The resulting crude product was then subjected to silica gel column chromatography (eluent: hexane / toluene = 1 / 1, ethyl acetate), and washed with hexane (10 ml) to obtain compound (v-10113) (11 mg) as a yellow solid.

[0641] MALDI-TOF-MS(M + )=1321.711

[0642] Synthesis example (8): Synthesis of compound (v-10131) [ka]

[0643] The compound (Int-v-10054) was replaced with compound (Int-v-10131), and the solvent was changed from toluene to o-dichlorobenzene, except that the compound was synthesized in the same manner as in synthesis example (3). MALDI-TOF-MS(M + ) = 1361.652

[0644] Synthesis example (9): Synthesis of compound (v-10114) [ka]

[0645] The compound (Int-v-10054) was replaced with compound (Int-v-10114), and the solvent was changed from toluene to o-dichlorobenzene, except that the compound was synthesized in the same manner as in synthesis example (3). MALDI-TOF-MS(M + ) = 1361.652

[0646] Synthesis example (10): Synthesis of compound (v-10132) [ka]

[0647] The compound (Int-v-10054) was replaced with compound (Int-v-10132), and the solvent was changed from toluene to o-dichlorobenzene, except that the compound was synthesized in the same manner as in synthesis example (3). MALDI-TOF-MS(M + )=1625.471

[0648] Synthesis example (11): Synthesis of compound (v-10133) [ka]

[0649] The compound was synthesized in the same manner as in synthesis example (3), except that compound (Int-v-10054) was replaced with compound (Int-v-10133) and the solvent was changed from toluene to o-dichlorobenzene. MALDI-TOF-MS(M + )=1560.63

[0650] Synthesis example (12): Synthesis of compound (v-10123) [ka]

[0651] The compound was synthesized in the same manner as in synthesis example (3), except that compound (Int-v-10054) was replaced with compound (Int-v-10123) and the solvent was changed from toluene to o-dichlorobenzene. MALDI-TOF-MS(M + ) = 1553.650

[0652] Synthesis example (13): Synthesis of compound (v-10124) [ka]

[0653] Compound (Int-v-10080) was converted to compound (Int-v-10124) by the method described in synthesis example (4). MALDI-TOF-MS(M + ) = 1026.500

[0654] Synthesis example (14): Synthesis of compound (v-10125) and compound (v-10126) [ka]

[0655] The compounds were synthesized in the same manner as in synthesis example (3), except that compound (Int-v-10054) was changed to compound (Int-v-10125), the solvent was changed from toluene to o-dichlorobenzene, and the target compounds (v-10125) and (v-10126) were isolated during GPC. Compound (v-10125):MALDI-TOF-MS(M + )=1149.517 Compound (v-10126):MALDI-TOF-MS(M + ) = 1149.517

[0656] Synthesis example (15): Synthesis of compound (v-10127) and compound (v-10128) [ka]

[0657] The compounds were synthesized in the same manner as in synthesis example (3), except that compound (Int-v-10054) was replaced with compound (Int-v-10127), the solvent was changed from toluene to o-dichlorobenzene, and the target compounds (v-10127) and (v-10128) were separated during GPC. Compound (v-10127):MALDI-TOF-MS(M + )=1133.535 Compound (v-10128):MALDI-TOF-MS(M + ) = 1133.537

[0658] Synthesis example (16): Synthesis of compound (v-10104) [ka]

[0659] The compound (Int-v-10054) was replaced with compound (Int-v-10104), and the solvent was changed from toluene to o-dichlorobenzene, except that the compound was synthesized in the same manner as in synthesis example (3). MALDI-TOF-MS(M + ) = 1377.767

[0660] Synthesis example (17): Synthesis of compound (v-10139) [ka]

[0661] The compound (Int-v-10054) was replaced with compound (Int-v-10139), and the solvent was changed from toluene to o-dichlorobenzene, except that the compound was synthesized in the same manner as in synthesis example (3). MALDI-TOF-MS(M + ) = 1140.554

[0662] Synthesis example (18): Synthesis of compound (v-10135) [ka]

[0663] The compound was synthesized in the same manner as in synthesis example (3), except that compound (Int-v-10054) was replaced with compound (Int-v-10135) and the solvent was changed from toluene to o-dichlorobenzene. MALDI-TOF-MS(M + ) = 1026.319

[0664] By appropriately changing the raw material compounds, other compounds can be synthesized using a method similar to the synthesis example described above.

[0665] Next, we will describe the evaluation of the basic physical properties of the compound of the present invention and the fabrication and evaluation of an organic EL element using the compound of the present invention. However, the application of the compound of the present invention is not limited to the examples shown below, and the film thickness and constituent materials of each layer can be appropriately changed depending on the basic physical properties of the compound of the present invention.

[0666] <<Evaluation Method>> <Evaluation of basic physical properties of compounds> Preparation of PMMA dispersion membrane A commercially available PMMA (polymethyl methacrylate) matrix material and the compound under evaluation (1% by mass) were dissolved in toluene. Then, a thin film was formed on a transparent quartz support substrate (10 mm × 10 mm) by spin coating to create a PMMA dispersion film.

[0667] Evaluation of absorption and emission properties The absorption spectra of the samples were measured using a UV-Vis-Near-Infrared spectrophotometer (Shimadzu Corporation, UV-2600). The fluorescence spectra or phosphorescence spectra of the samples were measured using a spectrofluorometer (Hitachi High-Tech Corporation, F-7000).

[0668] For fluorescence spectroscopy measurements, the PMMA dispersion film was excited at room temperature with an appropriate excitation wavelength (280 nm) and photoluminescence was measured. For phosphorescence spectroscopy measurements, the PMMA dispersion film was immersed in liquid nitrogen (77 K) using the attached cooling unit. To observe the phosphorescence spectrum, an optical chopper was used to adjust the delay time from excitation light irradiation to the start of measurement.

[0669] For the full width at half maximum (FWHM) of emission, the width of the spectrum at half the height of the emission peak in the fluorescence spectrum was measured.

[0670] Evaluation of fluorescence lifetime (delayed fluorescence, Tau(delay)) The fluorescence lifetime was measured at 300K using a PMMA dispersion film and a fluorescence lifetime analyzer (Hamamatsu Photonics K.K., C11367-01). Specifically, both the fast- and slow-emission components of the fluorescence lifetime were observed at the maximum emission wavelength measured at an excitation wavelength of 280 nm. In typical room-temperature fluorescence lifetime measurements of organic EL materials that emit fluorescence, the slow-emission component involving the phosphorescent triplet component is rarely observed due to thermal deactivation of the triplet component. If a slow-emission component is observed in the compound under evaluation, it indicates that the triplet energy with a long excitation lifetime shifted to the singlet energy due to thermal activation and was observed as delayed fluorescence.

[0671] Measurement of the lowest excited singlet energy level E(S,Sh) and the lowest excited triplet energy level E(T,Sh). For PMMA dispersion films, the fluorescence spectrum is observed at 77K using a long-wavelength peak as the excitation light, such that the fluorescence peaks of the absorption spectrum do not overlap. The lowest excited singlet energy level E(S,Sh) is then determined from the short-wavelength shoulder of the fluorescence spectrum peak. Furthermore, a phosphorescence spectrum is observed on a PMMA dispersion film at 77K using nm excitation light, with the peak on the longer wavelength side of the absorption spectrum not overlapping. The lowest excited triplet energy level E(T,Sh) is then determined from the short-wavelength shoulder of the peak in that phosphorescence spectrum. ΔE S1T1 This was calculated by subtracting the lowest excited triplet energy level E(T,Sh) from the lowest excited singlet energy level E(S,Sh).

[0672] Evaluation of purity reduction during sublimation The purity of the target compounds before and after sublimation was measured by HPLC (eluent: methanol or acetonitrile with 0.1-49% water or acetic acid added), and the area percentage of the target peak was compared. An area decrease of less than 0.1% was recorded as "<0.1%", an area decrease of 1% or more was recorded as ">1%", and all other results were recorded numerically.

[0673] <Evaluation of Organic EL Devices> Evaluation items and evaluation methods The evaluation items include driving voltage (V), emission wavelength (nm), CIE chromaticity (x,y), external quantum efficiency (%), maximum wavelength (nm) and full width at half maximum (nm) of the emission spectrum. These evaluation items are, for example, 1000 cd / m². 2 The value at the time of emission can be used.

[0674] 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, external quantum efficiency is lower than internal quantum efficiency.

[0675] The measurement method for spectral radiance (emission spectrum) and external quantum efficiency is as follows: Using an Advantest R6144 voltage / current generator, the device's radiance was 1000 cd / m². 2 A voltage is applied to cause the element to emit light. A TOPCON SR-3AR spectroradiometer is used to measure the spectral radiance in the visible light region from a direction perpendicular to the light-emitting surface. Assuming the light-emitting surface is a perfectly diffusive surface, the number of photons at each wavelength is obtained by dividing the measured spectral radiance value of each wavelength component by the wavelength energy and multiplying by π. Next, the number of photons is integrated across the entire observed wavelength range to obtain the total number of photons emitted from the element. The number of carriers injected into the element is obtained by dividing the applied current value by the elementary charge, and the external quantum efficiency is obtained by dividing the total number of photons emitted from the element by the number of carriers injected into the element. The full width at half maximum of the emission spectrum is determined as the width between the wavelengths above and below the maximum emission wavelength where the intensity is 50%.

[0676] <<Basic Physical Properties of Compounds>> The evaluation results of the compounds are shown in Table 1.

[0677] [Table 1]

[0678] [ka]

[0679] The compounds (v-4010), (v-10054), (v-10132), and (v-10133) described in this invention have molecular weights similar to or greater than new-DABNA, but exhibit low sublimation temperatures and no decrease in purity during sublimation. The compounds of this invention have low sublimation temperatures due to the large molecular strain and low symmetry. On the other hand, the decrease in purity during sublimation is very small, indicating the structural stability of the compounds.

[0680] Furthermore, the compounds of the present invention yielded a preferred emission spectrum in terms of emission wavelength (blue) and full width at half maximum. The compounds used in these examples were ΔE S1T1 From the Tau(Delay) value, it can be seen that it has high TADF properties. In detail, the ΔE of the compound of the present invention S1T1 ΔE of new-DABNA S1T1 It is larger compared to, but the Tau(Delay) value is almost the same as new-DABNA, and the ΔE of DABNA1 S1T1 Despite being almost identical in performance, Tau (Delay) is nearly an order of magnitude faster.

[0681] Although the emission wavelengths of the compounds of the present invention are longer than those of DABNA1 and new-DABNA, the emission wavelengths of compounds (v-10132) and (v-10133) are not significantly different from those of devices fabricated using DABNA1. This is presumably because the molecular strain and low symmetry of the compounds of the present invention reduce intermolecular interactions within the device. The compound (new-DABNA) (a compound described in International Publication No. 2018 / 212169) has emission wavelength, full width at half maximum, and ΔE S1T1While it exhibited excellent properties in terms of Tau(Delay), a slight decrease in purity was observed during sublimation. This is thought to be due to the high sublimation temperature resulting from the large molecular weight and high symmetry.

[0682] <<Fabrication and Evaluation of Vapor-Deposited Organic EL Devices>> <Example 1> A 26mm x 28mm x 0.7mm glass substrate (manufactured by OptoScience Co., Ltd.), which had been polished to 50nm by sputtering an ITO film to a thickness of 200nm, was used as a transparent support substrate. This transparent support substrate was fixed to the substrate holder of a commercially available deposition apparatus (manufactured by Showa Vacuum Co., Ltd.), and molybdenum deposition boats containing NPD, TcTa, mCP, BH-2, compound (v-4001), 2CzBN, and BPy-TP2, respectively, and tungsten deposition boats containing LiF and aluminum, respectively, were attached.

[0683] The following layers were sequentially formed on the ITO film of the transparent support substrate. The vacuum chamber was 5 × 10 -4 The pressure was reduced to Pa, and first, an NPD was heated and deposited to a thickness of 40 nm to form a hole injection layer. Next, TcTa was heated and deposited to a thickness of 15 nm to form a hole transport layer. Next, mCP was heated and deposited to a thickness of 15 nm to form an electron blocking layer. Next, BH-2 and compound (v-4001) were heated simultaneously and deposited to a thickness of 20 nm to form an emissive layer. The deposition rate was adjusted so that the weight ratio of BH-1 to compound (v-4001) was approximately 99:1. Next, 2CzBN was heated and deposited to a thickness of 10 nm, and then BPy-TP2 was heated and deposited to a thickness of 20 nm to form a two-layer electron transport layer. The deposition rate for each layer was 0.01 to 1 nm / second. After that, LiF was heated and deposited at a deposition rate of 0.01 to 0.1 nm / second to a thickness of 1 nm, and then aluminum was heated and deposited to a thickness of 100 nm to form a cathode, thereby obtaining an organic EL device. At this time, the aluminum deposition rate was adjusted to 1-10 nm / second.

[0684] <Comparative Example 1, Example 2> The dopant compound (v-4001) from Example 1 was replaced with each of the dopants listed in Table 2, and devices were fabricated.

[0685] <Rating> The fabricated element was subjected to a DC voltage, with the ITO electrode as the anode and the aluminum electrode as the cathode, resulting in a brightness of 500 cd / m². 2 In this case, emission wavelength, full width at half maximum, driving voltage, external quantum efficiency, and LT50 (initial brightness 500 cd / m²) 2 250 cd / m² when continuously driven at the current density in the given location. 2 The time it took to reach a certain state was measured. The evaluation results are shown in Table 3.

[0686] [Table 2]

[0687] In Table 2, "HAT-CN" is 1,4,5,8,9,12-hexaazatriphenylenehexacarbonnitrile. "TcTa" is 4,4',4"-tris(N-carbazolyl)triphenylamine, "mCP" is 1,3-bis(N-carbazolyl)benzene, "2CzBN" is 3,4-dicarbazolylbenzonitrile. "BPy-TP2" is 2,7-di([2,2'-bipyridine]-5-yl)triphenylene. The chemical structures of "BH-2" and "RBD-4" are shown below.

[0688] [ka]

[0689] [Table 3]

[0690] <Examples 3-1 to 15, Comparative Example 3-1, Examples 4-1 to 15, Comparative Example 4-1, Examples 5-1 to 15, Comparative Example 5-1> [Comparative Example 3-1] A 26mm x 28mm x 0.7mm glass substrate (manufactured by OptoScience Co., Ltd.), which had been polished to 120nm by sputtering an ITO film to a thickness of 200nm, was used as a transparent support substrate. This transparent support substrate was fixed to the substrate holder of a commercially available deposition apparatus (manufactured by Showa Vacuum Co., Ltd.), and molybdenum deposition boats containing HAT-CN, HTL-1, TcTa, ETL-1, DABNA1, and ET7, respectively, and tungsten deposition boats containing LiF and aluminum, respectively, were attached.

[0691] The following layers were sequentially formed on the ITO film of the transparent support substrate. The vacuum chamber was 5 × 10 -4 The pressure was reduced to Pa, and first, HAT-CN was heated and deposited to a thickness of 5 nm to form a hole injection layer. Next, HTL-1 was heated and deposited to a thickness of 90 nm to form hole transport layer 1, and then TcTa was heated and deposited to a thickness of 10 nm to form hole transport layer 2. Next, TcTa, ETL-1, and DABNA1 were heated simultaneously and deposited to a thickness of 20 nm to form an emissive layer. The deposition rate was adjusted so that the mass ratio of TcTa, ETL-1, and DABNA1 was approximately 49.5:49.5:1. Next, ETL-1 was heated and deposited to a thickness of 20 nm to form electron transport layer 1, and then ET7 was heated and deposited to a thickness of 10 nm to form electron transport layer 2. The deposition rate for each layer was 0.01 to 1 nm / second. Subsequently, LiF was heated and deposited at a deposition rate of 0.01 to 0.1 nm / second to achieve a film thickness of 1 nm. Then, aluminum was heated and deposited to a film thickness of 100 nm to form a cathode, thereby obtaining an organic EL device. At this time, the deposition rate of the aluminum was adjusted to 1 to 10 nm / second.

[0692] [Examples 3-1 to 15, Examples 4-1 to 15, Comparative Example 4-1, Examples 5-1 to 15, and Comparative Example 5-1] Organic EL elements for Examples 3-1 to 15, Examples 4-1 to 15, Comparative Example 4-1, Examples 5-1 to 15, and Comparative Example 5-1 were obtained using the same procedure as for Comparative Example 3-1, except that the composition of the light-emitting layer of Comparative Example 3-1 was changed as shown in Table 4. In Table 4, "Host 1" corresponds to a hole-transporting host material, and "Host 2" corresponds to an electron-transporting host material.

[0693] [Table 4] TIFF202614364400...

Claims

1. Polycyclic aromatic compounds represented by formula (4); 【Chemistry 1】 In formula (4), Rings A, B, D, C, and E are each independently a substituted or substituted aryl ring or a substituted heteroaryl ring. Y is independently B, P, P=O or P=S, n is independently either 0 or 1. Each X is independent of >C(-R) ２ , >N-R, >O, >Si(-R) ２ >S, or >Se, In X, R in >N-R is an optionally substituted aryl, optionally substituted heteroaryl, optionally substituted alkyl, or optionally substituted cycloalkyl, and in X, >C(-R) ２ and >Si(-R) ２ R is hydrogen, an optionally substituted aryl, an optionally substituted alkyl, or an optionally substituted cycloalkyl, and >C(-R) ２ and >Si(-R) ２ The two Rs in each may be bonded to each other to form a ring, and also the >N-R, the >C(-R) ２ , and the above >Si(-R) ２ At least one of R may be bonded to at least one of the A, B, C, D, or E rings by a linking group or single bond. At least one selected from the group consisting of an aryl ring and a heteroaryl ring in the polycyclic aromatic compound may be fused with at least one cycloalkane, at least one hydrogen in the cycloalkane may be substituted, and at least one -CH in the cycloalkane ２ - may be substituted with -O-, At least one hydrogen atom in the polycyclic aromatic compound may be substituted with deuterium, cyano, or halogen.

2. The polycyclic aromatic compound according to claim 1, wherein Y is B in all cases.

3. The polycyclic aromatic compound according to claim 1 or 2, wherein the substituents on an optionally substituted aryl ring or optionally substituted heteroaryl ring, which is ring A, ring B, ring D, ring C, or ring E, are optionally alkyl-substituted aryl, optionally alkyl-substituted diarylamino, or alkyl.

4. The polycyclic aromatic compound according to any one of claims 1 to 3, wherein the A ring, B ring, D ring, C ring, and E ring are all benzene rings which may have substituents.

5. A polycyclic aromatic compound according to any one of claims 1 to 4, wherein n is 1 in all cases.

6. A polycyclic aromatic compound according to claim 1, represented by any of the following formulas; 【Chemistry 2】 【Transformation 3】 【Chemistry 4】 【Transformation 5】 In the formula, Me represents methyl and tBu represents t-butyl.

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

8. The organic device material according to claim 7, wherein the organic device material is a material for an organic electroluminescent device, a material for an organic field-effect transistor, or a material for an organic thin-film solar cell.

9. The material for an organic device according to claim 8, wherein the material for the organic electroluminescent element is a material for the light-emitting layer.

10. An organic electroluminescent element comprising a pair of electrodes consisting of an anode and a cathode, and an organic layer disposed between the pair of electrodes and containing a polycyclic aromatic compound according to any one of claims 1 to 6.

11. The organic electroluminescent element according to claim 10, wherein the organic layer is a light-emitting layer.

12. The organic electroluminescent element according to claim 11, wherein the light-emitting layer comprises a host material and the polycyclic aromatic compound as a dopant material.

13. The organic electroluminescent element according to claim 12, wherein the host material is a compound having a lowest excited triplet energy level at least 0.01 eV higher than the lowest excited triplet energy level of the polycyclic aromatic compound.

14. A display device or lighting device comprising an organic electroluminescent element according to any one of claims 10 to 13.

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