Polycyclic aromatic compound and organic electroluminescent element

Abstract

To provide a polycyclic aromatic compound for an organic EL element.SOLUTION: A polycyclic aromatic compound represented by formula (1) is used, for example, in an emission layer of an organic EL element together with a high-T1 compound having a lowest triplet excited energy level at least 0.01 eV higher than the lowest triplet excited energy level of the polycyclic aromatic compound, and exhibits high external quantum efficiency. A to E rings are aryl rings or heteroaryl rings, at least one of A to E rings is a monocyclic heteroaryl ring, at least one of A to E rings has a group of formula (2) as a substituent, L is a single bond, O, or the like, * denotes the bonding position with an aryl ring or heteroaryl ring, F ring is an aryl ring or heteroaryl ring, and R is an aryl ring, heteroaryl ring, alkyl group, or the like.SELECTED DRAWING: Figure 1

Description

Technical Field

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

Background Art

[0002] Conventionally, display devices using light-emitting devices that emit light by an electric field have been frequently studied because they can save power and be made thin. Furthermore, organic electroluminescent devices (which may be referred to as "organic EL devices" or simply "devices" in this specification) made of organic materials have been actively studied because they can be easily made lightweight and large-sized. In particular, regarding the development of organic materials having light-emitting characteristics such as blue and green, which are one of the three primary colors of light, and the development of organic materials having charge transport capabilities (capable of becoming semiconductors or superconductors) such as holes and electrons, active research has been conducted so far regardless of whether they are high-molecular compounds or low-molecular compounds.

[0003] An organic EL device has a structure including a pair of electrodes composed of a positive electrode and a negative electrode, and one or more layers containing an organic compound disposed between the pair of electrodes. The layer containing an organic compound (which may be referred to as an "organic layer" in this specification) includes a light-emitting layer, a charge transport / injection layer that transports or injects charges such as holes and electrons, and various organic materials suitable for these layers have been developed.

[0004] Among them, Patent Document 1 discloses that polycyclic aromatic compounds in which aromatic rings are linked by hetero elements such as boron, phosphorus, oxygen, nitrogen, and sulfur are useful as materials for organic electroluminescent devices and the like. This polycyclic aromatic compound has a large HOMO-LUMO gap and a high lowest excited triplet energy level (ET), and at the same time exhibits thermally activated delayed fluorescence, and has been reported to be particularly useful as a fluorescent material for organic electroluminescent devices.

Prior Art Documents

Patent Documents

[0005] Patent Document 1 International Publication No. 2015 / 102118 SUMMARY OF THE INVENTION PROBLEMS TO BE SOLVED BY THE INVENTION

[0006] As described above, various materials have been developed as materials used in organic EL elements. However, in order to increase the options for materials for organic EL elements, the development of materials composed of compounds different from the conventional ones is expected. An object of the present invention is to provide a novel material useful as a material for organic devices such as organic EL elements.

[0007] Another object of the present invention is to provide an organic electroluminescent element using a new combination of materials. In particular, an object of the present invention is to provide an organic EL element having a high external quantum efficiency. MEANS FOR SOLVING THE PROBLEMS

[0008] As a result of intensive studies to solve the above problems, the present inventors succeeded in producing a new compound as a polycyclic aromatic compound in which an aromatic ring is linked by a hetero element such as boron, phosphorus, oxygen, nitrogen, or sulfur. Further, it has been found that an excellent organic EL element can be obtained by disposing a layer containing this polycyclic aromatic compound between a pair of electrodes to form an organic EL element, and the present invention has been completed. That is, the present invention provides the following polycyclic aromatic compounds, materials for organic devices containing the following polycyclic aromatic compounds, and the like.

[0009] <1> A polycyclic aromatic compound represented by the following formula (1): [Chemical formula]

[0010] In the above formula (1), the A ring, B ring, C ring, D ring, and E ring are each independently a substituted or unsubstituted aryl ring or a substituted or unsubstituted heteroaryl ring, However, at least one of Ring A, Ring B, Ring C, Ring D, and Ring E is a substituted or unsubstituted monocyclic heteroaryl ring, however, at least one of Ring A, Ring B, Ring C, Ring D, and Ring E has a group represented by the formula (2) as a substituent, L is, independently of each other, a single bond, >O, >N-R NX , >C(-R CX )2, -C(-R CX )=C(-R CX )-, >Si(-R IX )2, >S, >CO, >CS, >SO, >SO2, >SeO, >SeO2, >PO, >B(-R PX ), or >Se, R NX , R CX , R IX and R PX are, independently of each other, hydrogen, a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted alkyl, or a substituted or unsubstituted cycloalkyl, and the two R CX may be bonded to each other to form a ring, and the two R IX may be bonded to each other to form a ring, In the above structure, at least one selected from the group consisting of an aryl ring and a heteroaryl ring may be condensed with at least one cycloalkane, the cycloalkane may be substituted with at least one substituent, and at least one -CH2- of the cycloalkane may be substituted with -O-, In formula (2), * represents the bonding position with an aryl ring or a heteroaryl ring, Ring F is a substituted or unsubstituted aryl ring or a substituted or unsubstituted heteroaryl ring, R is a substituted or unsubstituted aryl ring, a substituted or unsubstituted heteroaryl ring, a substituted or unsubstituted alkyl, or a substituted or unsubstituted cycloalkyl, In Formula (1) and Formula (2), at least one hydrogen may be substituted with deuterium, cyano or halogen, and at least one nitrogen is nitrogen-15 ( 15 N), at least one sulfur is sulfur-33 ( 33 S), sulfur-34 ( 34 S), or sulfur-36 ( 36 S), at least one oxygen is oxygen-17 ( 17 O), or oxygen-18 ( 18 O), at least one carbon is carbon-13 ( 13 C), at least one boron may be substituted with boron-11 ( 11 B).

[0011] <2>The polycyclic aromatic compound according to <1>, wherein Formula (1) is represented by the following Formula (1’):

Chemical formula

[0012] In Formula (1’), L is the same as the definition of L in Formula (1), Z is independently -C(-R ZE )= or -N=, provided that at least one of Z is -N=, R ZE is each independently selected from the group consisting of hydrogen, deuterium, halogen, cyano group, nitro group, substituted or unsubstituted silyl group, substituted or unsubstituted amino group, substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, substituted or unsubstituted cycloalkyl group having 3 to 30 carbon atoms, substituted or unsubstituted aryl group having 6 to 30 carbon atoms, substituted or unsubstituted heteroaryl group having 2 to 30 carbon atoms, and a group represented by Formula (2’), provided that substituents substituted on adjacent atoms may be bonded to each other to form a ring, provided that at least one of R ZE has a group represented by Formula (2’), In Formula (2’), R is the same as the definition of R in Formula (2), and * is R ZERepresents the bonding position with.

[0013] <3>R is a substituted or unsubstituted aryl ring, a substituted or unsubstituted heteroaryl ring, a substituted or unsubstituted alkyl, or a substituted or unsubstituted cycloalkyl, the polycyclic aromatic compound described in <1> or <2>.

[0014] <4>The formula (1’) is represented by any one of the following chemical formulas (1’-1) to (1’-7), the polycyclic aromatic compound described in <2>:

Chemical formula

[0015] In the chemical formulas (1’-1) to (1’-7), L is the same as the definition of L in the formula (1), At least one ring has a group represented by the formula (2) as a substituent.

[0016] <5>The formula (1’) is the polycyclic aromatic compound described in <2>, represented by the following formula (1”):

Chemical formula

[0017] In the formula (1”), Z is the same as the definition in the formula (1’).

[0018] <6>The formula (1”) is represented by any one of the following chemical formulas (1”-1) to (1”-7), the polycyclic aromatic compound described in <5>:

Chemical formula

[0019] In the chemical formulas (1”-1) to (1”-7), At least one ring has a group represented by the formula (2) as a substituent.

[0020] <7>The formula (1”) is the polycyclic aromatic compound according to <5>, which is represented by any one of the following chemical formulas (1”-1) to (1”-4), (1”-6), and (1”-7):

Chem.

[0021] In the chemical formulas (1”-1) to (1”-4), (1”-6), and (1”-7), at least one ring has a group represented by the formula (2) as a substituent.

[0022] <8>The formula (2) is the polycyclic aromatic compound according to <1>, which is represented by any one of the following chemical formulas (2-1) to (2-7):

Chem.

[0023] In the chemical formulas (2-1) to (2-7), * represents the bonding position with an aryl ring or a heteroaryl ring.

[0024] <9>The formula (1) is the polycyclic aromatic compound according to <1>, which is represented by any one of the following chemical formulas.

Chem.

Chem.

[0025] <10>An organic electroluminescent device including a pair of electrodes composed of a positive electrode and a negative electrode, and an organic layer disposed between the pair of electrodes, wherein the organic layer contains the polycyclic aromatic compound according to any one of <1> to <9>. <11>The organic electroluminescent device according to <10>, wherein the organic layer is a light-emitting layer. <12>The organic electroluminescent device according to <11>, wherein the light-emitting layer contains the polycyclic aromatic compound as a host material and a dopant material. <13>The organic electroluminescent device according to <12>, wherein the host material is an anthracene compound, a fluorene compound, or a dibenzochrysene compound. <14>The organic electroluminescent device according to <11>, wherein the light-emitting layer contains a host material, a thermally activated delayed phosphor or a phosphorescent material, and the polycyclic aromatic compound as a light-emitting dopant. <15>A display device or a lighting device including the organic electroluminescent device according to any one of <10> to <14>.

Advantages of the Invention

[0026] According to the present invention, a novel polycyclic aromatic compound is provided. The polycyclic aromatic compound of the present invention is useful as a material for an organic device, particularly as a material for a light-emitting layer for forming a light-emitting layer of an organic electroluminescent device.

Brief Description of the Drawings

[0027]

Figure 1

Embodiments for Carrying Out the Invention

[0028] Hereinafter, the present invention will be described in detail. The description of the constituent elements described below may be made based on typical embodiments or specific examples, but the present invention is not limited to such embodiments. In the present specification, the numerical range indicated by "~" means a range including the numerical values described before and after "~" as a lower limit value and an upper limit value. In the present specification, "hydrogen" in the description of the structural formula means "hydrogen atom (H)".

[0029] In the present specification, the "adjacent groups" mean two groups each bonded to two adjacent atoms (two atoms directly bonded by a covalent bond) in the structural formula.

[0030] In this specification, there are cases where chemical structures and substituents are represented by the number of carbon atoms. However, when a substituent is substituted on a chemical structure, or when a substituent is further substituted on a substituent, the number of carbon atoms means the number of carbon atoms of each of the chemical structure and the substituent, and does not mean the total number of carbon atoms of the chemical structure and the substituent, or the total number of carbon atoms of the substituent and the substituent. For example, "substituent B having Y carbon atoms substituted with substituent A having X carbon atoms" means that "substituent A having X carbon atoms" substitutes "substituent B having Y carbon atoms", and the number of carbon atoms Y is not the total number of carbon atoms of substituent A and substituent B. Also, for example, "substituent B having Y carbon atoms substituted with substituent A" means that "(substituent A with no limitation on the number of carbon atoms)" substitutes "substituent B having Y carbon atoms", and the number of carbon atoms Y is not the total number of carbon atoms of substituent A and substituent B.

[0031] 1. Polycyclic aromatic compound 1-1. Polycyclic aromatic compound The present invention is a polycyclic aromatic compound represented by formula (1). This polycyclic aromatic compound is useful as a compound for forming highly efficient and long-life elements. Also, it is less likely to be decomposed during vapor deposition compared to similar compounds having a similar molecular weight.

[0032] <Explanation of formula (1)> Hereinafter, in this specification, the polycyclic aromatic compound represented by the following formula (1) will be described.

Chemical formula

[0033] In formula (1), "A", "B", "C", "D", and "E" are each independently symbols representing a ring structure.

[0034] In formula (1), ring A, ring B, ring C, ring D, and ring E are each independently a substituted or unsubstituted aryl ring, or a substituted or unsubstituted heteroaryl ring.

[0035] However, at least one of ring A, ring B, ring C, ring D, and ring E is a substituted or unsubstituted monocyclic heteroaryl ring.

[0036] Examples of the "aryl ring" of ring A, ring B, ring C, ring D, and ring E in formula (1) include aryl rings having 6 to 30 carbon atoms, preferably aryl rings having 6 to 16 carbon atoms, more preferably aryl rings having 6 to 12 carbon atoms, and particularly preferably aryl rings having 6 to 10 carbon atoms.

[0037] Specific examples of the "aryl ring" include monocyclic benzene rings, bicyclic biphenyl rings, condensed bicyclic naphthalene rings, indene rings, tricyclic terphenyl rings (m-terphenyl, o-terphenyl, p-terphenyl), condensed tricyclic acenaphthylene rings, fluorene rings, phenalene rings, phenanthrene rings, anthracene rings, condensed tetracyclic triphenylene rings, pyrene rings, naphthacene rings, chrysene rings, condensed pentacyclic perylene rings, pentacene rings, etc. In addition, the fluorene ring, benzofluorene ring, and indene ring also include structures in which a fluorene ring, benzofluorene ring, cyclopentane ring, etc. are spiro-bonded, respectively. Further, in the fluorene ring, benzofluorene ring, and indene ring, two of the two hydrogens of methylene are each substituted with an alkyl such as methyl as the first substituent described later, and those which have become dimethylfluorene rings, dimethylbenzofluorene rings, dimethylindene rings, etc. are also included.

[0038] Examples of the "heteroaryl ring" of ring A, ring B, ring C, ring D, and ring E in formula (1) include heteroaryl rings having 2 to 30 carbon atoms, preferably heteroaryl rings having 2 to 25 carbon atoms, more preferably heteroaryl rings having 2 to 20 carbon atoms, still more preferably heteroaryl rings having 2 to 15 carbon atoms, and particularly preferably heteroaryl rings having 2 to 10 carbon atoms. Further, examples of the "heteroaryl ring" include heterocyclic rings containing 1 to 5 heteroatoms selected from oxygen, sulfur, and nitrogen in addition to carbon as ring-constituting atoms.

[0039] Specific "heteroaryl rings" include, for example, 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, pyrazine ring, triazine ring, indole ring, isoindole ring, 1H-indazole ring, benzimidazole ring, benzoxazole ring, benzothiazole ring, 1H-benzotriazole ring, quinoline ring, isoquinoline ring, cinnoline ring, quinazoline ring, quinoxaline ring, phthalazine ring, naphthyridine ring, purine ring, pteridine ring, carbazole ring, acridine ring, phenoxathiin ring, phenoxazine ring, phenothiazine ring, phenazine ring, phenazasilin ring, indolizine ring, furan ring, benzofuran ring, isobenzofuran ring, dibenzofuran ring, thiophene ring, benzothiophene ring, dibenzothiophene ring, furazan ring, thianthrene ring, indolocarbazole ring, benzindolocarbazole ring, benzobenzindolocarbazole ring, naphthobenzofuran ring, dioxin ring, dihydroacridine ring, xanthene ring, thioxanthene ring, dibenzodioxin ring, dibenzazepine ring, tribenzoazepine ring, iminodibenzyl ring and the like. Further, in the dihydroacridine ring, xanthene ring, thioxanthene ring, it is also preferable that two of the two hydrogens of methylene are each substituted with an alkyl such as methyl as the first substituent described later, resulting in a dimethyldihydroacridine ring, dimethylxanthene ring, dimethylthioxanthene ring and the like. Further, the bicyclic bipyridine ring, phenylpyridine ring, pyridylphenyl ring, the tricyclic terpyridine ring, bispyridylphenyl ring, pyridylbiphenyl ring are also mentioned as "heteroaryl rings". Further, the "heteroaryl ring" shall also include a pyran ring.

[0040] When at least one hydrogen in the 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 (amino having an aryl and a heteroaryl), a substituted or unsubstituted diarylboril (two aryls may be bonded via 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, cyano, halogen, or -L-Ak. Examples of the substituent when these groups have a substituent include aryl, heteroaryl, alkyl, cycloalkyl, cyano, halogen, or diarylamino.

[0041] The "halogen" includes fluorine, chlorine, bromine, or iodine, and is preferably fluorine. Hereinafter, "halogen" is used with the same meaning.

[0042] At least one hydrogen in the said "aryl ring" or "heteroaryl ring" is a substituted or unsubstituted "aryl", substituted or unsubstituted "heteroaryl", substituted or unsubstituted "diaryl amino", substituted or unsubstituted "diheteroaryl amino", substituted or unsubstituted "aryl heteroaryl amino", substituted or unsubstituted "diaryl boryl (the two aryls 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 may be substituted with -L-Ak as the first substituent. As the "aryl", "heteroaryl", aryl of "diaryl amino", heteroaryl of "diheteroaryl amino", aryl and heteroaryl of "aryl heteroaryl amino", aryl of "diaryl boryl", or aryl of "aryloxy" as the first substituent, examples include monovalent groups of the said "aryl ring" or "heteroaryl ring".

[0043] Specifically, examples of "aryl" include aryl having 6 to 30 carbon atoms, preferably aryl having 6 to 24 carbon atoms, more preferably aryl having 6 to 20 carbon atoms, still more preferably aryl having 6 to 16 carbon atoms, particularly preferably aryl having 6 to 12 carbon atoms, and most preferably aryl having 6 to 10 carbon atoms.

[0044] Specific aryls include, for example, phenyl of monocyclic aryl, (2-, 3-, 4-) biphenylyl of bicyclic aryl, (1-, 2-) naphthyl of condensed bicyclic aryl, (2-, 3-, 4-, 5-, 6-, 7-) indenyl, terphenyl of tricyclic aryl (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), acenaphthylen-(1-, 3-, 4-, 5-)yl, fluorene-(1-, 2-, 3-, 4-, 9-)yl, phenalen-(1-, 2-)yl, (1-, 2-, 3-, 4-, 9-)phenanthryl of condensed tricyclic aryl, quarterphenyl of tetracyclic aryl (5'-phenyl-m-terphenyl-2-yl, 5'-phenyl-m-terphenyl-3-yl, 5'-phenyl-m-terphenyl-4-yl, m-quarterphenyl), triphenylene-(1-, 2-)yl, pyrene-(1-, 2-, 4-)yl, naphthacene-(1-, 2-, 5-)yl of condensed tetracyclic aryl, perylene-(1-, 2-, 3-)yl, pentacene-(1-, 2-, 5-, 6-)yl of condensed pentacyclic aryl, etc.

[0045] In addition, examples of "heteroaryl" include heteroaryl having 2 to 30 carbon atoms, preferably heteroaryl having 2 to 25 carbon atoms, more preferably heteroaryl having 2 to 20 carbon atoms, still more preferably heteroaryl having 2 to 15 carbon atoms, and particularly preferably heteroaryl having 2 to 10 carbon atoms. Further, examples of heteroaryl include heterocycles containing 1 to 5 heteroatoms selected from oxygen, sulfur, and nitrogen in addition to carbon as ring-constituting atoms.

[0046] Specific heteroaryls include, for example, furyl, thienyl, pyrrolyl, oxazolyl, isoxazolyl, thiazolyl, isothiazolyl, imidazolyl, pyrazolyl, oxadiazolyl, furazanyl, thiadiazolyl, triazolyl, tetrazolyl, pyridyl, pyrimidinyl, pyridazinyl, pyrazinyl, triazinyl, benzofuranyl, isobenzofuranyl, dibenzofuranyl, benzo[b]thienyl, dibenzothienyl, indolyl, isoindolyl, 1H-indazolyl, benzimidazolyl, benzoxazolyl, benzothiazolyl, 1H-benzotriazolyl, quinolyl, isoquinolyl, cinnolyl, quinazolinyl, quinoxalinyl, phthalazinyl, naphthyridinyl, purinyl, pteridinyl, carbazolyl, acridinyl, phenoxazinyl, phenothiazinyl, phenazinyl, phenoxathiinyl, thianthrenyl, indolizinyl, etc.

[0047] Also, the "alkyl" as the first substituent may be either straight-chain or branched-chain. For example, straight-chain alkyl having 1 to 24 carbon atoms or branched-chain alkyl having 3 to 24 carbon atoms can be mentioned. Alkyl having 1 to 18 carbon atoms (branched-chain alkyl having 3 to 18 carbon atoms) is preferred, alkyl having 1 to 12 carbon atoms (branched-chain alkyl having 3 to 12 carbon atoms) is more preferred, alkyl having 1 to 8 carbon atoms (branched-chain alkyl having 3 to 8 carbon atoms) is further preferred, alkyl having 1 to 6 carbon atoms (branched-chain alkyl having 3 to 6 carbon atoms) is particularly preferred, and alkyl having 1 to 5 carbon atoms (branched-chain alkyl having 3 to 5 carbon atoms) is most preferred.

[0048] 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, t-octyl (1,1,3,3-tetramethylbutyl), 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, n-eicosyl, and the like.

[0049] Also, for example, 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, 1,1-dimethylhexyl, and the like can also be mentioned.

[0050] As a substituent 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 a bulky substituent increases the intermolecular distance, thereby improving the photoluminescence quantum yield (PLQY). In addition, a substituent in which the tertiary alkyl represented by the formula (tR) is substituted with another substituent as the second substituent is also preferred. Specifically, diarylamino substituted with the tertiary alkyl represented by the formula (tR), carbazolyl substituted with the tertiary alkyl represented by the formula (tR) (preferably, N-carbazolyl), or benzocarbazolyl substituted with the tertiary alkyl represented by the formula (tR) (preferably, N-benzocarbazolyl) can be mentioned. Regarding "diarylamino", groups described in the following "first substituent" can be mentioned. As the substitution form of the group of the formula (tR) for diarylamino, carbazolyl, and benzocarbazolyl, examples include those in which some or all of the hydrogens of the aryl ring or benzene ring in these groups are substituted with the group of the formula (tR).

Chemical formula

[0051] Among the formula (tR), R a 、R b 、and R c are each independently an alkyl having 1 to 24 carbon atoms, and any -CH2- in the alkyl may be substituted with -O-, and * is the bonding position.

[0052] R a 、R b 、and R cThe "alkyl group having 1 to 24 carbon atoms" may be either a straight-chain or a branched-chain, and examples thereof include a straight-chain alkyl group having 1 to 24 carbon atoms or a branched-chain alkyl group having 3 to 24 carbon atoms, an alkyl group having 1 to 18 carbon atoms (a branched-chain alkyl group having 3 to 18 carbon atoms), an alkyl group having 1 to 12 carbon atoms (a branched-chain alkyl group having 3 to 12 carbon atoms), an alkyl group having 1 to 6 carbon atoms (a branched-chain alkyl group having 3 to 6 carbon atoms), and an alkyl group having 1 to 4 carbon atoms (a branched-chain alkyl group having 3 to 4 carbon atoms).

[0053] R in formula (tR) a , R b , and R c The total number of carbon atoms of is preferably 3 to 20 carbon atoms, and particularly preferably 3 to 10 carbon atoms.

[0054] R a , R b , and R c Specific examples of the alkyl group of 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-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, n-eicosyl, and the like.

[0055] Examples of the group represented by the formula (tR) include t-butyl, t-amyl, 1-ethyl-1-methylpropyl, 1,1-diethylpropyl, 1,1-dimethylbutyl, 1-ethyl-1-methylbutyl, 1,1,3,3-tetramethylbutyl, 1,1,4-trimethylpentyl, 1,1,2-trimethylpropyl, 1,1-dimethyloctyl, 1,1-dimethylpentyl, 1,1-dimethylheptyl, 1,1,5-trimethylhexyl, 1-ethyl-1-methylhexyl, 1-ethyl-1,3-dimethylbutyl, 1,1,2,2-tetramethylpropyl, 1-butyl-1-methylpentyl, 1,1-diethylbutyl, 1-ethyl-1-methylpentyl, 1,1,3-trimethylbutyl, 1-propyl-1-methylpentyl, 1,1,2-trimethylpropyl, 1-ethyl-1,2,2-trimethylpropyl, 1-propyl-1-methylbutyl, 1,1-dimethylhexyl, etc. Among these, t-butyl and t-amyl are preferred.

[0056] Examples of the "cycloalkyl" as the first substituent include cycloalkyl having 3 to 24 carbon atoms, cycloalkyl having 3 to 20 carbon atoms, cycloalkyl having 3 to 16 carbon atoms, cycloalkyl having 3 to 14 carbon atoms, cycloalkyl having 5 to 10 carbon atoms, cycloalkyl having 5 to 8 carbon atoms, cycloalkyl having 5 to 6 carbon atoms, cycloalkyl having 5 carbon atoms, etc.

[0057] Specific examples of cycloalkyl include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl, and their alkyl (especially methyl) substituents having 1 to 5 carbon atoms, 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, decahydroazulenyl, etc.

[0058] In addition, examples of the "alkoxy" as the first substituent include linear alkoxy having 1 to 24 carbon atoms or branched alkoxy having 3 to 24 carbon atoms. Alkoxy having 1 to 18 carbon atoms (branched alkoxy having 3 to 18 carbon atoms) is preferred, alkoxy having 1 to 12 carbon atoms (branched alkoxy having 3 to 12 carbon atoms) is more preferred, alkoxy having 1 to 6 carbon atoms (branched alkoxy having 3 to 6 carbon atoms) is even more preferred, and alkoxy having 1 to 5 carbon atoms (branched alkoxy having 3 to 5 carbon atoms) is particularly preferred.

[0059] Specific examples of alkoxy include methoxy, ethoxy, propoxy, isopropoxy, butoxy, isobutoxy, s-butoxy, t-butoxy, t-amyloxy, pentyloxy, hexyloxy, heptyloxy, octyloxy, and the like.

[0060] In addition, examples of the "substituted silyl" as the first substituent include silyl substituted with three substituents selected from the group consisting of alkyl, cycloalkyl, and aryl. For example, trialkylsilyl, tricycloalkylsilyl, dialkylcycloalkylsilyl, alkyldicycloalkylsilyl, triarylsilyl, dialkylarylsilyl, and alkyldiarylsilyl can be mentioned.

[0061] Examples of the "trialkylsilyl" include groups in which three hydrogens in the silyl group are each independently substituted with alkyl, and as this alkyl, the groups described as the "alkyl" in the first substituent can be cited. Preferred alkyl for substitution is alkyl having 1 to 5 carbon atoms, and specifically, methyl, ethyl, propyl, i-propyl, butyl, sec-butyl, t-butyl, t-amyl, and the like can be mentioned.

[0062] Specific trialkylsilyls include trimethylsilyl, triethylsilyl, tripropylsilyl, tri-i-propylsilyl, tributylsilyl, tri-sec-butylsilyl, tri-t-butylsilyl, tri-t-amylsilyl, ethyldimethylsilyl, propyldimethylsilyl, i-propyldimethylsilyl, butyldimethylsilyl, sec-butyldimethylsilyl, t-butyldimethylsilyl, t-amyl-dimethylsilyl, methyldiethylsilyl, propyldiethylsilyl, i-propyldiethylsilyl, butyldiethylsilyl, sec-butyldiethylsilyl, t-butyldiethylsilyl, t-amyl-diethylsilyl, methyldipropylsilyl, ethyldipropylsilyl, butyldipropylsilyl, sec-butyldipropylsilyl, t-butyldipropylsilyl, t-amyl-dipropylsilyl, methyldi-i-propylsilyl, ethyldi-i-propylsilyl, butyldi-i-propylsilyl, sec-butyldi-i-propylsilyl, t-butyldi-i-propylsilyl, t-amyl-di-i-propylsilyl, and the like.

[0063] "Tricycloalkylsilyl" includes groups in which the three hydrogens in the silyl group are each independently substituted with cycloalkyl. As this cycloalkyl, the groups described as "cycloalkyl" in the first substituent can be cited. Preferred cycloalkyls for substitution are cycloalkyls 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, decahydroazulenyl, and the like.

[0064] Specific tricycloalkylsilyls include tricyclopentylsilyl, tricyclohexylsilyl, and the like.

[0065] Specific examples of dialkylcycloalkylsilyl substituted with two alkyls and one cycloalkyl and alkyldicycloalkylsilyl substituted with one alkyl and two cycloalkyls include silyls substituted with groups selected from the specific alkyls and cycloalkyls described above.

[0066] Specific examples of dialkylarylsilyl substituted with two alkyls and one aryl, alkyldiarylsilyl substituted with one alkyl and two aryls, and triarylsilyl substituted with three aryls include silyls substituted with groups selected from the specific alkyls and aryls described above. Specific examples of triarylsilyl include, in particular, triphenylsilyl.

[0067] Also, as the "aryl" in the "diarylboroyl" of the first substituent, the description of the aryl mentioned above can be cited. Further, these two aryls may be bonded via a single bond or a linking group (for example, >C(-R)2, >O, >S, or >N-R). Here, R in >C(-R)2 and >N-R 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 cite the description of aryl, heteroaryl, diarylamino, alkyl, cycloalkyl, alkoxy, or aryloxy as the first substituent mentioned above.

[0068] In -L-Ak of the first substituent, L is >N-R, >O, or >S, and R in the >N-R is optionally substituted aryl, optionally substituted heteroaryl, optionally substituted alkyl, or optionally substituted cycloalkyl. Also, R in the >N-R may be bonded to Ak by a linking group or a single bond.

[0069] Ak is hydrogen, optionally substituted alkyl, or optionally substituted cycloalkyl, at least one hydrogen in the alkyl and cycloalkyl may be optionally substituted, and at least one -CH2- in the alkyl and cycloalkyl may be substituted with -O- and -S-.

[0070] L is preferably >N-R.

[0071] When L is >N-R, R is preferably aryl optionally substituted with alkyl or cycloalkyl, heteroaryl optionally substituted with alkyl or cycloalkyl, alkyl, or cycloalkyl, more preferably aryl optionally substituted with alkyl, heteroaryl optionally substituted with alkyl, alkyl, or cycloalkyl, even more preferably aryl optionally substituted with alkyl, and particularly preferably phenyl optionally substituted with methyl.

[0072] Ak is preferably alkyl having 1 to 6 carbon atoms or cycloalkyl having 3 to 14 carbon atoms, more preferably alkyl having 1 to 4 carbon atoms or cycloalkyl having 3 to 8 carbon atoms, even more preferably alkyl having 1 to 4 carbon atoms, and particularly preferably methyl.

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

Chemical formula

[0074] In each of the above formulas, Me is methyl, and at the position of *, it is bonded to a ring-constituting atom of an aryl ring or a heteroaryl ring in Ring A, Ring B, Ring C, Ring D, or Ring E.

[0075] The first substituent, a substituted or unsubstituted "aryl", a substituted or unsubstituted "heteroaryl", a substituted or unsubstituted "diaryl amino", a substituted or unsubstituted "diheteroaryl amino", a substituted or unsubstituted "aryl heteroaryl amino", a substituted or unsubstituted "diaryl boryl (the two aryls may be bonded via 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", or a substituted "silyl", as described as substituted or unsubstituted, at least one hydrogen in these may be substituted with a second substituent. Examples of this second substituent include aryl, heteroaryl, alkyl, or cycloalkyl, and specific examples thereof can be referred to the description of the monovalent group of the aforementioned "aryl ring" or "heteroaryl ring", and the "alkyl" or "cycloalkyl" as the first substituent. Further, in the aryl or heteroaryl as the second substituent, at least one hydrogen in them is also included in the aryl or heteroaryl as the second substituent in a structure substituted with an aryl such as phenyl (specific examples are the aforementioned groups), an alkyl such as methyl or t-butyl (specific examples are the aforementioned groups), or a cycloalkyl such as cyclohexyl (specific examples are the aforementioned groups). As an example thereof, when the second substituent is carbazolyl, carbazolyl in which at least one hydrogen at the 9-position is substituted with an aryl such as phenyl, an alkyl such as methyl, or a cycloalkyl such as cyclohexyl is also included in the heteroaryl as the second substituent.

[0076] The emission wavelength can be adjusted by the steric hindrance, electron-donating property, and electron-withdrawing property of the structure of the first substituent. Preferably, it is a group represented by the following structural formula, 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-dimethylcarbazolyl, 3,6-di-t-butylcarbazolyl, and phenoxy, and even more preferably methyl, t-butyl, t-amyl, t-octyl, neopentyl, adamantyl, phenyl, o-tolyl, 2,6-xylyl, 2,4,6-mesityl, diphenylamino, di-p-tolylamino, bis(p-(t-butyl)phenyl)amino, carbazolyl, 3,6-dimethylcarbazolyl, and 3,6-di-t-butylcarbazolyl. From the viewpoint of ease of synthesis, a larger steric hindrance is preferable for selective synthesis. 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 preferable.

[0077] In the following structural formula, "Me" represents methyl, "tBu" represents t-butyl, "tAm" represents t-amyl, "tOct" represents t-octyl, and * indicates the bonding position.

Chemical formula

Chemical formula

Chemical formula

Chemical formula

Chemical formula

Chem.

Chem.

Chem.

Chem.

Chem.

Chem.

Chem.

Chem.

Chem.

Chem.

[0078] The substituent when two or three hydrogens bonded to consecutive (adjacent) carbon atoms are substituted may be a group represented by formula (A20).

Chem.

[0079] In formula (A20), L Sis >N-R, >O, >Si(-R)2, or >S, where R in >N-R is optionally substituted aryl, optionally substituted heteroaryl, optionally substituted alkyl, or optionally substituted cycloalkyl, 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. Further, at least one of R in >N-R and >Si(-R)2 is bonded to at least one selected from the group consisting of A ring, B ring, C ring, D ring, E ring, and R S by a linking group or a single bond, and may be r is an integer from 1 to 4, 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 by a linking group or a single bond, The group represented by formula (A20) is bonded to two adjacent atoms on the ring of an aryl ring, heteroaryl ring, or cycloalkane ring by two * respectively.

[0080] When the polycyclic aromatic compound represented by formula (1) contains the group represented by formula (A20), the number thereof is preferably one or two. The group represented by formula (A20) may be a substituent in any one of the A ring, B ring, C ring, D ring, and E ring.

[0081] The group represented by formula (A20) is bonded to two *s, respectively, to two adjacent atoms on the ring of an aryl ring or a heteroaryl ring. The group represented by formula (A20) is preferably bonded to two adjacent atoms on an aryl ring or a heteroaryl ring with two *s. At this time, it is preferable that both of the two adjacent atoms on the ring are carbon atoms. When the group represented by formula (A20) is bonded to an aryl ring or a heteroaryl ring, a condensed ring structure is formed. The compound represented by formula (1) having this condensed ring structure has a more rigid structure for the compound. When rigidified, the vibration of the molecule is suppressed, the EQE is improved, the stability of the molecule is enhanced, and the device lifetime is expected to be prolonged.

[0082] 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 polycyclic aromatic compound represented by formula (1). When L S is N-R, >O, or >S, the HOMO and LUMO become shallower, and when it is Si, the HOMO and LUMO become deeper. When the HOMO and LUMO become shallower, it is expected that the TTF device using this will have a long lifetime, high efficiency, and low driving voltage. On the other hand, when the HOMO and LUMO become deeper, it is expected that the hole trapping property of the dopant will disappear and the driving voltage will be significantly reduced.

[0083] L in formula (A20) S in >N-R, R is an aryl which may be substituted, a heteroaryl which may be substituted, an alkyl which may be substituted, or a cycloalkyl which may be substituted. L in formula (A20) S in >Si(-R)2, R is hydrogen, an aryl which may be substituted, an alkyl which may be substituted, or a cycloalkyl which may be substituted, and two Rs may be bonded to each other to form a ring. Further, at least one of R in the >N-R and the >Si(-R)2 is connected to ring A, ring B, ring C, ring D, ring E, and R by a linking group or a single bondS It may be combined with at least one selected from the group consisting of. L is preferably >N-R, >O, or >S, more preferably >N-R or >O, and even more preferably >N-R.

[0084] L S When L is >N-R, R is preferably aryl optionally substituted with alkyl or cycloalkyl, heteroaryl optionally substituted with alkyl or cycloalkyl, alkyl, or cycloalkyl, more preferably aryl optionally substituted with alkyl or cycloalkyl, or heteroaryl optionally substituted with alkyl or cycloalkyl, even more preferably aryl optionally substituted with alkyl or cycloalkyl, and particularly preferably phenyl optionally substituted with alkyl or cycloalkyl.

[0085] In formula (A20), r is an integer from 1 to 4, preferably 2 or 3, and more preferably 2.

[0086] In formula (A20), R S are each independently hydrogen, optionally substituted alkyl, or optionally substituted cycloalkyl, and any R S may be linked to any other R S by a linking group or a single bond.

[0087] R SIt is preferable that any two of them are bonded to each other by a linking group or a single bond. Examples of the linking group include >O, >S, etc. Examples of the divalent group formed by bonding to each other include alkylene. At least one hydrogen in the alkylene may be substituted with alkyl or cycloalkyl, and at least one (preferably one) -CH2- in the alkylene may be substituted with -O- and -S-. As the divalent group formed by bonding to each other, a linear alkylene having 2 to 5 carbon atoms is preferable, a linear alkylene having 3 or 4 carbon atoms is more preferable, and a linear alkylene having 4 carbon atoms (-(CH2)4-) is even more preferable. The linear alkylene having 4 carbon atoms (-(CH2)4-) is particularly preferably unsubstituted.

[0088] Two Rs each bonded to adjacent carbon atoms S When they are bonded to each other by a linking group or a single bond, the remaining Rs not involved in this bond S are each independently hydrogen or optionally substituted alkyl, or are preferably bonded to the R of >N-R or >Si(-R)2 which is L S

[0089] Two Rs each bonded to adjacent carbon atoms S When they are bonded to each other by a linking group or a single bond, the remaining Rs not involved in this bond S As the optionally substituted alkyl as the remaining R, it is more preferably an optionally substituted alkyl having 1 to 6 carbon atoms, even more preferably an unsubstituted alkyl having 1 to 6 carbon atoms, and most preferably all methyl.

[0090] That is, as a preferable example of the group represented by the formula (A20), a group represented by the formula (A20-a) can be mentioned.

Chemical formula

[0091] ​In the formula, Me is methyl.

[0092] L S Of >N-R and >Si(-R)2, at least one of the Rs may be bonded to at least one selected from the group consisting of ring A, ring B, ring C, ring D, ring E, and R S through a linking group or a single bond. When L S is >N-R, examples thereof include groups represented by any one of the following formulas, and a group represented by formula (A20-b-1) is preferred.

Chemical formula

[0093] In each formula, Me is methyl. In each formula, * is bonded to two or three atoms that are consecutive (adjacent) on the ring of any one of ring A, ring B, ring C, ring C, ring D, and ring E, which are an aryl ring, a heteroaryl ring, or a cycloalkane ring, respectively.

[0094] In formula (1), each L is independently a single bond, >O, >N-R NX , >C(-R CX )2, -C(-R CX )=C(-R CX )-, >Si(-R IX )2, >S, >CO, >CS, >SO, >SO2, >SeO, >SeO2, >PO, >B(-R PX ), or >Se, and R NX , R CX , R IX , and R PX are each independently hydrogen, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted alkyl, or substituted or unsubstituted cycloalkyl, and the two Rs CX may be bonded to each other to form a ring, and the two Rs IX may be bonded to each other to form a ring.

[0095] In formula (1), at least one selected from the group consisting of an aryl ring and a heteroaryl ring in the structure may be condensed with at least one cycloalkane, the cycloalkane may be substituted with at least one substituent, and at least one -CH2- in the cycloalkane may be substituted with -O-.

[0096] Examples of the "cycloalkane" include cycloalkanes having 3 to 24 carbon atoms, cycloalkanes having 3 to 20 carbon atoms, cycloalkanes having 3 to 16 carbon atoms, cycloalkanes having 3 to 14 carbon atoms, cycloalkanes having 5 to 10 carbon atoms, cycloalkanes having 5 to 8 carbon atoms, cycloalkanes having 5 to 6 carbon atoms, and cycloalkanes having 5 carbon atoms.

[0097] Specific examples of the cycloalkane 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, and their C1-C5 alkyl (especially methyl) substituents, halogen (especially fluorine) substituents, and deuterium substituents.

[0098] Among these, a structure in which at least one hydrogen at the α-position carbon of the cycloalkane (in the cycloalkyl condensed with an aryl ring or a heteroaryl ring, the carbon at the position adjacent to the carbon of the condensation site) is substituted is preferred, a structure in which two hydrogens at the α-position carbon are substituted is more preferred, and a structure in which a total of four hydrogens at two α-position carbons are substituted is even more preferred. Examples of this substituent include an alkyl (especially methyl) substituent having 1 to 5 carbon atoms, a halogen (especially fluorine) substituent, and a deuterium substituent. In particular, in the aryl ring or heteroaryl ring, a structure in which a partial structure represented by the following formula (B10) is bonded to adjacent carbon atoms is preferred.

Chemical formula

[0099] In formula (B10), Me represents methyl, and * indicates the bonding position.

[0100] In formula (1), at least one of ring A, ring B, ring C, ring D, and ring E has a group represented by the above formula (2) as a substituent. Formula (2) will be specifically described below.

[0101] In the above formula (1), at least one hydrogen may be substituted with deuterium, cyano, or halogen, at least one nitrogen is nitrogen-15 ( 15 N), at least one sulfur is sulfur-33 ( 33 S), sulfur-34 ( 34 S), or sulfur-36 ( 36 S), at least one oxygen is oxygen-17 ( 17 O), or oxygen-18 ( 18 O), at least one carbon is carbon-13 ( 13 C), and at least one boron may be substituted with boron-11 ( 11 B).

[0102] <Explanation of formula (1’)>

Chemical formula

[0103] The above formula (1) may also be represented by the above formula (1’). In formula (1’), L is the same as the definition of L in formula (1). In formula (1’), Z is independently -C(-R ZE )= or -N=, provided that at least one of Z is -N=. The above R ZE are each independently selected from the group consisting of hydrogen, deuterium, halogen, cyano group, nitro group, substituted or unsubstituted silyl group, substituted or unsubstituted amino group, substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, substituted or unsubstituted cycloalkyl group having 3 to 30 carbon atoms, substituted or unsubstituted aryl group having 6 to 30 carbon atoms, substituted or unsubstituted heteroaryl group having 2 to 30 carbon atoms, and a group represented by formula (2’), provided that substituents substituted on adjacent atoms may be bonded to each other to form a ring.

[0104] However, at least one of R ZE has a group represented by the following formula (2’).

Chemical formula

[0105] In formula (2’), R is the same as the definition of R in formula (2), and * represents the bonding position with R ZE .

[0106] The above formula (1’) may be represented by any one of the following chemical formulas (1’-1) to (1’-7):

Chemical formula

[0107] In the above chemical formulas (1’-1) to (1’-7), L is the same as the definition of L in formula (1), and at least one has a group represented by the above formula (2) as a substituent.

[0108] <Explanation of Formula (1”)>

Chem.

[0109] The above Formula (1) may also be represented by the above Formula (1”). In Formula (1”), Z is the same as defined in Formula (1’). The above Formula (1”) may be represented by any one of the following Chemical Formulas (1”-1) to (1”-7):

[0110]

Chem.

[0111] In the above Chemical Formulas (1”-1) to (1”-7), at least one has a group represented by the above Formula (2) as a substituent.

[0112] The above Formula (1”) may be represented by any one of Chemical Formulas (1”-1) to (1”-4), (1”-6) and (1”-7).

[0113] <Explanation of Formula (2)> Among the A ring, B ring, C ring, D ring, and E ring in Formula (1), at least one has a group represented by the above Formula (2) as a substituent.

Chem.

[0114] In the above Formula (2), * indicates the bonding position with an aryl ring or a heteroaryl ring. In Formula (2), the F ring is a substituted or unsubstituted aryl ring, or a substituted or unsubstituted heteroaryl ring. In formula (2), R is a substituted or unsubstituted aryl ring, a substituted or unsubstituted heteroaryl ring, a substituted or unsubstituted alkyl, or a substituted or unsubstituted cycloalkyl.

[0115] In formula (2), examples of the "aryl ring" of the F ring include aryl rings having 6 to 30 carbon atoms, preferably aryl rings having 6 to 16 carbon atoms, more preferably aryl rings having 6 to 12 carbon atoms, and particularly preferably aryl rings having 6 to 10 carbon atoms.

[0116] In formula (2), examples of the "heteroaryl ring" of the F ring include heteroaryl rings having 2 to 30 carbon atoms, preferably heteroaryl rings having 2 to 25 carbon atoms, more preferably heteroaryl rings having 2 to 20 carbon atoms, still more preferably heteroaryl rings having 2 to 15 carbon atoms, and particularly preferably heteroaryl rings having 2 to 10 carbon atoms. Examples of the "heteroaryl ring" include heterocyclic rings containing 1 to 5 heteroatoms selected from oxygen, sulfur, and nitrogen in addition to carbon as ring-constituting atoms.

[0117] In the F ring, the aryl ring may be selected from the group consisting of a benzene ring, a biphenyl ring, a terphenyl ring, an indene ring, a naphthalene ring, a fluorene ring, an anthracene ring, and a phenanthrene ring, and the heteroaryl ring may be selected from the group consisting of a benzofuran ring, a benzothiophene ring, an indole ring, a dibenzofuran ring, a dibenzothiophene ring, a carbazole ring, a naphthofuran ring, a naphthothiophene ring, a benzoindole ring, and a benzoselenophene ring. The F ring is preferably a substituted or unsubstituted benzene ring, a substituted or unsubstituted biphenyl ring, a substituted or unsubstituted terphenyl ring, a substituted or unsubstituted benzothiophene ring, or a substituted or unsubstituted benzofuran ring.

[0118] When at least one hydrogen in the 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 (amino having an aryl and a heteroaryl), a substituted or unsubstituted diarylboryl (the two aryls may be bonded via 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, cyano, halogen, or -L-Ak. Examples of the substituent when these groups have a substituent include aryl, heteroaryl, alkyl, cycloalkyl, cyano, halogen, or diarylamino.

[0119] In formula (2), the "aryl ring" and "heteroaryl ring" of R are the same as the definitions of the "aryl ring" and "heteroaryl ring" in the F ring.

[0120] In formula (2), the "alkyl" of R may be either linear or branched, and examples include linear alkyl having 1 to 24 carbon atoms or branched alkyl having 3 to 24 carbon atoms. Alkyl having 1 to 18 carbon atoms (branched alkyl having 3 to 18 carbon atoms) is preferred, alkyl having 1 to 12 carbon atoms (branched alkyl having 3 to 12 carbon atoms) is more preferred, alkyl having 1 to 8 carbon atoms (branched alkyl having 3 to 8 carbon atoms) is even more preferred, alkyl having 1 to 6 carbon atoms (branched alkyl having 3 to 6 carbon atoms) is particularly preferred, and alkyl having 1 to 5 carbon atoms (branched alkyl having 3 to 5 carbon atoms) is most preferred.

[0121] 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, t-octyl (1,1,3,3-tetramethylbutyl), 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, n-eicosyl, and the like.

[0122] Also, for example, 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, 1,1-dimethylhexyl, and the like can also be mentioned.

[0123] In formula (2), the "cycloalkyl" of R includes cycloalkyl having 3 to 24 carbon atoms, cycloalkyl having 3 to 20 carbon atoms, cycloalkyl having 3 to 16 carbon atoms, cycloalkyl having 3 to 14 carbon atoms, cycloalkyl having 5 to 10 carbon atoms, cycloalkyl having 5 to 8 carbon atoms, cycloalkyl having 5 to 6 carbon atoms, cycloalkyl having 5 carbon atoms, and the like.

[0124] Specific cycloalkyls include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl, and their C1-C5 alkyl (especially methyl) substituents, 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, decahydroazulenyl, and the like.

[0125] In the formula (2), at least one hydrogen may be substituted with deuterium, cyano or halogen, at least one nitrogen is nitrogen-15 ( 15 N), at least one sulfur is sulfur-33 ( 33 S), sulfur-34 ( 34 S), or sulfur-36 ( 36 S), at least one oxygen is oxygen-17 ( 17 O), or oxygen-18 ( 18 O), at least one carbon is carbon-13 ( 13 C), at least one boron is boron-11 ( 11 B) and may be substituted.

[0126] The formula (2) may be represented by any one of the following chemical formulas (2-1) to (2-7):

Chemical formula

[0127] In the chemical formulas (2-1) to (2-7), * represents the bonding position with an aryl ring or a heteroaryl ring.

[0128] <Substitution with deuterium> In the polycyclic aromatic compound containing the structural unit represented by the formula (1), all or part of the hydrogen may be deuterium. The same applies to the polycyclic aromatic compound represented by the formula (1') or the formula (1").

[0129] For example, the hydrogen in the aryl ring or heteroaryl ring of the A ring, B ring, C ring, D ring, E ring, or F ring, and the substituents thereof may be replaced by deuterium, and examples thereof include the aspect in which all or part of the hydrogen in the aryl or heteroaryl is replaced by deuterium. Also, from the viewpoint of durability, it is preferable that all or part of the hydrogen in the polycyclic aromatic compound containing the structural unit represented by the formula (1) is deuterated.

[0130] <Specific examples of polycyclic aromatic compounds> Examples of the polycyclic aromatic compound containing the structural unit represented by the formula (1) include compounds represented by any one of the following structural formulas. On the other hand, "Me" in the following structural formulas represents methyl, "tBu" represents t-butyl, and "D" represents deuterium.

Chemical formula

[0131]

Chemical formula

[0132]

Chemical formula

[0133]

Chemical formula

[0134]

Chemical formula

[0135]

Chemical formula

[0136]

Chem.

[0137]

Chem.

[0138]

Chem.

[0139]

Chem.

[0140]

Chem.

[0141]

Chem.

[0142]

Chem.

[0143]

Chem.

[0144]

Chem.

[0145]

Chem.

[0146] [Chemistry]

[0147] [Chemistry]

[0148] [Chemistry]

[0149] [Chemistry]

[0150] [Chemistry]

[0151] [Chemistry]

[0152] [Chemistry]

[0153] Examples of the structural unit represented by formula (2) include a group represented by any one of the following structural formulas: [Chemistry]

[0154] [Chemistry]

[0155] 1-2. Reactive compound, polymer compound, polymer crosslinked body, pendant-type polymer compound, pendant-type polymer crosslinked body The polycyclic aromatic compound represented by formula (1) can also be used as a material for organic devices, for example, a material for an organic electroluminescent element, a material for an organic field effect transistor, or a material for an organic thin film solar cell, as a polymer compound obtained by polymerizing a reactive compound having a reactive substituent as a monomer (the monomer for obtaining this polymer compound has a polymerizable substituent), or a polymer crosslinked body obtained by further crosslinking the polymer compound (the polymer compound for obtaining this polymer crosslinked body has a crosslinkable substituent), or a pendant polymer compound obtained by reacting a main chain type polymer with the reactive compound (the reactive compound for obtaining this pendant polymer compound has a reactive substituent), or a pendant polymer crosslinked body obtained by further crosslinking the pendant polymer compound (the pendant polymer compound for obtaining this pendant polymer crosslinked body has a crosslinkable substituent).

[0156] On the other hand, in this specification, the "polymer compound" has a molecular weight distribution and a number average molecular weight in terms of polystyrene of 1 × 10 3 ~1 × 10 8 (1 × 10^3 to 1 × 10^8). The number average molecular weight (Mn) of the polymer compound in terms of polystyrene is 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 about 0.05% by mass, and 10 μL is injected into the SEC. The flow rate of the mobile phase is 1.0 mL / min, and PLgel MIXED_B (manufactured by Polymer Laboratories) is used as the column. A UV_VIS detector (manufactured by Tosoh Corporation, product name: UV-8320GPC) may be used as the detector.

[0157] The polymer compound of the present invention preferably has a number average molecular weight of 2000 to 1 × 10 8 and more preferably 5000 to 1 × 10 8 .

[0158] The reactive substituents (including the polymerizable substituents, the crosslinkable substituents, and the reactive substituents for obtaining the pendant-type polymer, hereinafter simply referred to as "reactive substituents") are not particularly limited as long as they are substituents capable of polymerizing the polycyclic aromatic compound, substituents capable of further crosslinking the polymer compound thus obtained, and substituents capable of undergoing a pendant reaction with the main-chain polymer. Examples include alkenyl, alkynyl, unsaturated cycloalkyls (e.g., cyclobutenyl), groups in which at least one -CH2- in cycloalkyl is substituted with -O- (e.g., epoxy), unsaturated condensed cycloalkanes (e.g., condensed cyclobutene), etc. Substituents having the following structures are preferred. * in each structural formula indicates the bonding position.

[0159]

Chemical formula

[0160] L is, independently of each other, a single bond, -O-, -S-, >C=O, -O-C(=O)-, alkylene having 1 to 12 carbon atoms, oxyalkylene having 1 to 12 carbon atoms, and polyoxyalkylene having 1 to 12 carbon atoms. Among these substituents, groups represented by formula (XLS-1), formula (XLS-2), formula (XLS-3), formula (XLS-9), formula (XLS-10), or formula (XLS-17) are preferred, and groups represented by formula (XLS-1), formula (XLS-3), or formula (XLS-17) are more preferred.

[0161] Details of the uses of these polymer compounds, polymer crosslinked bodies, pendant-type polymer compounds, and pendant-type polymer crosslinked bodies (hereinafter also simply referred to as "polymer compounds and polymer crosslinked bodies") will be described later.

[0162] 2. Method for producing polycyclic aromatic compound The method for producing a polycyclic aromatic compound containing the structure represented by formula (1) can basically be carried out by bonding the A ring, B ring, and C ring linked to boron with a bonding group (>N) and then linking them to the D ring and E ring.

[0163] In the first reaction, for example, in the case of an etherification reaction, general reactions such as a nucleophilic substitution reaction or a Ullmann reaction can be used, and in the case of an amination reaction, a general reaction such as a backward Hartwig reaction can be used. Further, in the second reaction, a tandem hetero Friedel-Crafts reaction (successive aromatic electrophilic substitution reaction, the same applies hereinafter) can be used. Regarding these production methods, reference can be made to the methods described in prior art documents such as International Publication No. 2015 / 102118.

[0164] 3. Organic device The polycyclic aromatic compound according to the present invention may be used as a material for an organic device. Examples of the organic device include an organic electroluminescent element, an organic field effect transistor, or an organic thin film solar cell.

[0165] 3-1. Organic electroluminescent device The organic electroluminescent element has at least a pair of electrodes including a positive electrode and a negative electrode, and a light emitting layer disposed between the pair of electrodes. Hereinafter, the organic EL element according to the present embodiment will be described in detail with reference to the drawings.

[0166] 3-1-1. Structure of organic electroluminescent device FIG. 1 is a schematic cross-sectional view of an example of an organic EL element. The organic EL element (100) shown in FIG. 1 includes a substrate (101), a positive electrode (102) provided on the substrate (101), a hole injection layer (103) provided on the positive electrode (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 negative electrode (108) provided on the electron injection layer (107).

[0167] Alternatively, the organic EL element (100) may be configured in the reverse order of fabrication, for example, having a substrate (101), a negative electrode (108) disposed on the substrate (101), an electron injection layer (107) disposed on the negative electrode (108), an electron transport layer (106) disposed on the electron injection layer (107), a light-emitting layer (105) disposed on the electron transport layer (106), a hole transport layer (104) disposed on the light-emitting layer (105), a hole injection layer (103) disposed on the hole transport layer (104), and a positive electrode (102) disposed on the hole injection layer (103).

[0168] Not all of the above layers are necessary. With a minimum structural unit consisting of a positive electrode (102), a light-emitting layer (105), and a negative electrode (108), the hole injection layer (103), hole transport layer (104), electron transport layer (106), and electron injection layer (107) are optionally installed layers. Also, each of the above layers may consist of a single layer or multiple layers.

[0169] As aspects of the layers constituting the organic EL element, in addition to the above-described structural aspect of "substrate / positive electrode / hole injection layer / hole transport layer / hole transport layer / light-emitting layer / electron transport layer / electron injection layer / negative electrode", there may also be structural aspects such as "substrate / positive electrode / hole transport layer / light-emitting layer / electron transport layer / electron injection layer / negative electrode", "substrate / positive electrode / hole injection layer / light-emitting layer / electron transport layer / electron injection layer / negative electrode", "substrate / positive electrode / hole injection layer / hole transport layer / light-emitting layer / electron injection layer / negative electrode", "substrate / positive electrode / hole injection layer / hole transport layer / light-emitting layer / electron transport layer / negative electrode", "substrate / positive electrode / light-emitting layer / electron transport layer / electron injection layer / negative electrode", "substrate / positive electrode / hole transport layer / light-emitting layer / electron injection layer / negative electrode", "substrate / positive electrode / hole transport layer / light-emitting layer / electron injection layer / negative electrode", "substrate / positive electrode / hole injection layer / light-emitting layer / electron injection layer / negative electrode", "substrate / positive electrode / hole injection layer / light-emitting layer / electron transport layer / negative electrode", "substrate / positive electrode / light-emitting layer / electron transport layer / negative electrode", "substrate / positive electrode / light-emitting layer / electron injection layer / negative electrode".

[0170] 3-1-2. Substrate in organic electroluminescent device The substrate (101) is a support for the organic EL element (100), and usually, quartz, glass, metal, plastic, etc. are used. The substrate (101) is formed in a plate shape, film shape, or sheet shape according to the purpose, and for example, a glass plate, metal plate, metal foil, plastic film, plastic sheet, etc. are used. Among these, a glass plate and a plate made of a transparent synthetic resin such as polyester, polymethacrylate, polycarbonate, or polysulfone are preferable. In the case of a glass substrate, soda-lime glass or alkali-free glass is used, and the thickness only needs to be sufficient to maintain mechanical strength, so for example, 0.2 mm or more is sufficient. The upper limit value of the thickness is, for example, 2 mm or less, preferably 1 mm or less. Regarding the material of the glass, since it is better that there are fewer eluted ions from the glass, alkali-free glass is preferable, but soda-lime glass with a barrier coat such as SiO2 is also commercially available and can be used. Further, in order to enhance the gas barrier property, a gas barrier film such as a dense silicon oxide film may be provided on at least one side of the substrate (101), and it is particularly preferable to provide a gas barrier film when using a plate, film, or sheet made of a synthetic resin with a low gas barrier property as the substrate (101).

[0171] 3-1-3. Anode in organic electroluminescent device The positive electrode (102) serves to inject holes into the light-emitting layer (105). Also, when a hole injection layer (103) and / or a hole transport layer (104) are provided between the positive electrode (102) and the light-emitting layer (105), holes are injected into the light-emitting layer (105) through these layers.

[0172] Examples of materials for forming the positive electrode (102) include inorganic compounds and organic compounds. Examples of inorganic compounds include metals (such as aluminum, gold, silver, nickel, palladium, chromium, etc.), metal oxides (such as indium oxide, tin oxide, indium-tin oxide (ITO), indium-zinc oxide (IZO), etc.), metal halides (such as copper iodide, etc.), copper sulfide, carbon black, ITO glass, Nesa glass, etc. Examples of organic compounds include polythiophenes such as poly(3-methylthiophene), and conductive polymers such as polypyrrole and polyaniline. In addition, it may be appropriately selected from substances used as the positive electrode of the organic EL element and used.

[0173] The resistance of the transparent electrode is not limited as long as it can supply sufficient current for the light emission of the light-emitting element, but it is preferably low resistance from the viewpoint of the power consumption of the light-emitting element. For example, an ITO substrate with a resistance of 300 Ω / square or less can function as an element electrode, but currently, substrates with a resistance of about 10 Ω / square can also be supplied. Therefore, it is particularly preferable to use low-resistance products with a resistance of, for example, 100 Ω / square to 5 Ω / square, preferably 50 Ω / square to 5 Ω / square. The thickness of ITO can be arbitrarily selected according to the resistance value, but it is usually used in the range of 50 nm to 300 nm.

[0174] 3-1-4. Hole injection layer and hole transport layer in organic electroluminescent device The hole injection layer (103) serves to efficiently inject holes moving from the positive electrode (102) into the light-emitting layer (105) or the hole transport layer (104). The hole transport layer (104) serves to efficiently transport holes injected from the positive electrode (102) or holes injected from the positive electrode (102) through the hole injection layer (103) to the light-emitting layer (105). The hole injection layer (103) and the hole transport layer (104) are each formed by laminating or mixing one or more hole injection / transport materials, or by a mixture of a hole injection / transport material and a polymer binder. In addition, an inorganic salt such as iron(III) chloride may be added to the hole injection / transport material to form a layer.

[0175] As a hole injection / transport material, it is necessary to efficiently inject and transport holes from the anode between electrodes to which an electric field is applied. It is preferable that the hole injection efficiency is high and the injected holes are efficiently transported. For this purpose, it is preferable that the ionization potential is small, the hole mobility is large, the stability is excellent, and impurities that become traps are unlikely to occur during manufacturing and use.

[0176] As a material for forming the hole injection layer (103) and the hole transport layer (104), in a photoconductive material, any compound may be selected and used from compounds that have been conventionally used as hole charge transport materials, p-type semiconductors, and known compounds used for the hole injection layer and the hole transport layer of an organic EL element. Specific examples thereof include carbazole derivatives (N-phenylcarbazole, polyvinylcarbazole, etc.), biscarbazole derivatives such as bis(N-arylcarbazole) or bis(N-alkylcarbazole), triarylamine derivatives (polymers having an aromatic tertiary amino group in the main chain or side chain, 1,1-bis(4-di-p-tolylaminophenyl)cyclohexane, N,N'-diphenyl-N,N'-di(3-methylphenyl)-4,4'-diaminobiphenyl, N,N'-diphenyl-N,N'-dinaphthyl-4,4'-diaminobiphenyl, N,N'-diphenyl-N,N'-di(3-methylphenyl)-4,4'-diphenyl-1,1'-diamine, N,N'-dinaphthyl-N,N'-diphenyl-4,4'-diphenyl-1,1'-diamine, N 4 ,N 4’ -diphenyl-N 4 ,N 4’ -bis(9-phenyl-9H-carbazol-3-yl)-[1,1'-biphenyl]-4,4'-diamine, N 4 ,N 4 ,N 4’ ,N 4’-Tetra[1,1'-biphenyl]-4-yl)-[1,1'-biphenyl]-4,4'-diamine, 4,4',4''-tris(3-methylphenyl(phenyl)amino)triphenylamine, N-([1,1'-biphenyl]-4-yl)-9,9-dimethyl-N-(4-(9-phenyl-9H-carbazol-3-yl)phenyl)-9H-fluorene-2-amine, N,N-bis(4-(dibenzo[b,d]furan-4-yl)phenyl)-[1,1':4',1''-terphenyl]-4-amine and other triphenylamine derivatives, starburst amine derivatives, etc.), stilbene derivatives, phthalocyanine derivatives (metal-free, copper phthalocyanine, etc.), pyrazoline derivatives, hydrazone-based compounds, benzofuran derivatives and thiophene derivatives, oxadiazole derivatives, quinoxaline derivatives (for example, 1,4,5,8,9,12-hexaazatriphenylene-2,3,6,7,10,11-hexacarbonitrile, etc.), heterocyclic compounds such as porphyrin derivatives, polysilane, etc. In the polymer system, polycarbonate, styrene derivatives, polyvinylcarbazole, and polysilane having the above monomers in the side chain are preferable, but it is not particularly limited as long as it can form a thin film necessary for the production of the light-emitting element, holes can be injected from the positive electrode, and further holes can be transported.

[0177] Also, it is known that the conductivity of organic semiconductors is strongly affected by doping. The organic semiconductor matrix material is composed of a compound with good electron-donating properties or a compound with good electron-accepting properties. For doping with an electron-donating substance, strong electron acceptors such as tetracyanoquinodimethane (TCNQ) or 2,3,5,6-tetrafluorotetracyano-1,4-benzoquinodimethane (F4TCNQ) are known (for example, see the literature "M. Pfeiffer, A. Beyer, T. Fritz, K. Leo, Appl. Phys. Lett., 73(22), 3202 - 3204(1998)" and the literature "J. Blochwitz, M. Pfeiffer, T. Fritz, K. Leo, Appl. Phys. Lett., 73(6), 729 - 731(1998)"). These generate so-called holes by the electron transfer process in an electron-donating base material (hole transport material). The conductivity of the base material changes significantly depending on the number and mobility of the holes. As matrix materials having hole transport characteristics, for example, benzidine derivatives (such as TPD), or starburst amine derivatives (such as TDATA), or specific metal phthalocyanines (especially zinc phthalocyanine (ZnPc), etc.) are known (Japanese Patent Laid-Open No. 2005-167175).

[0178] The above-mentioned hole injection layer material and hole transport layer material may also be used as a hole layer material in the form of a polymer compound obtained by polymerizing a reactive compound having a reactive substituent substituted thereon as a monomer, or a polymer cross-linked body thereof, or a pendant polymer compound obtained by reacting a main-chain polymer with the reactive compound, or a pendant polymer cross-linked body thereof. As the reactive substituent in this case, the description in a polycyclic aromatic compound containing the structure represented by formula (1) can be cited.

[0179] Details of the uses of such polymer compounds and polymer cross-linked bodies will be described later.

[0180] 3-1-5. Light-emitting layer in organic electroluminescent device The light-emitting layer (105) emits light by recombining holes injected from the positive electrode (102) and electrons injected from the negative electrode (108) between electrodes to which an electric field is applied. As the material for forming the light-emitting layer (105), any compound (light-emitting compound) that is excited by the recombination of holes and electrons to emit light may be used, as long as it can form a stable thin film shape and exhibits strong light emission (fluorescence) efficiency in the solid state. The light-emitting layer may be either a single layer or a plurality of layers, and each is formed of a light-emitting layer material (host material, dopant material). The host material and the dopant material may each be of one type or a combination of a plurality of types. For example, an emitting dopant and an assist dopant may be used as the dopant material. The dopant material may be contained in the whole host material or partially contained, either way is acceptable. As the doping method, it can be formed by co-evaporation with the host material, but it may also be evaporated simultaneously after being premixed with the host material. Further, the light-emitting layer may be formed by a wet film-forming method using a light-emitting layer-forming composition prepared by dissolving the material in an organic solvent.

[0181] The polycyclic aromatic compound represented by formula (1) may preferably be used as a material for forming the light-emitting layer of an organic electroluminescent device. The polycyclic aromatic compound represented by formula (1) is more preferably used as an emitting dopant or an assist dopant in the light-emitting layer, and even more preferably used as an emitting dopant.

[0182] The polycyclic aromatic compound represented by formula (1) may be used as an emitting dopant of an organic EL device (hereinafter sometimes referred to as a "TADF device") that exhibits thermally activated delayed fluorescence (TADF) as a "thermally activated delayed phosphor". In a "thermally activated delayed phosphor", by reducing the energy difference between the lowest excited singlet state and the lowest excited triplet state, reverse intersystem crossing from the lowest excited triplet state, where the transition probability is usually low, to the lowest excited singlet state occurs with high efficiency, and light emission from the singlet state (thermally activated delayed fluorescence, TADF) is exhibited. In normal fluorescence emission, 75% of the triplet excitons generated by current excitation pass through the thermal deactivation path and thus cannot be extracted as fluorescence. On the other hand, in TADF, all excitons can be utilized for fluorescence emission, and a highly efficient organic EL device is realized.

[0183] The polycyclic aromatic compound represented by formula (1) may be used as an emitting dopant of a "TADF device", an emitting dopant of a TADF device using two types of hosts, an emitting dopant of an organic electroluminescent device (a TADF-assisted fluorescent (TAF) device) using another thermally activated delayed phosphor as an assist dopant, or an emitting dopant of an organic electroluminescent device (a phosphor-sensitized fluorescent (PSF) device) using a phosphorescent material as an assist dopant. From the viewpoint that it is easier to manufacture when the number of materials used in the device is smaller, the emitting dopant of a TADF device and the emitting dopant of a TADF device using two types of hosts are preferable, and the emitting dopant of a TADF device is more preferable. From the viewpoint of efficiency, the emitting dopant of a TAF device and the emitting dopant of a phosphorescent assist device are preferable, and the emitting dopant of a TAF device is more preferable.

[0184] Generally, it is considered that the faster the delayed fluorescence, the better the TADF property. 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, high device efficiency and a long device lifetime can be obtained. Also, generally, ΔES1T1 The smaller the value of S1T1 , the better the TADF property. On the other hand, ΔE S1 is the energy difference between the lowest excited singlet energy level (E T1 ) and the lowest excited triplet energy level (E S1T1 ). Specifically, the value of ΔE S1T1 is preferably 0.20 eV or less, and more preferably 0.15 eV or less.

[0185] The light-emitting layer may contain a host compound. Here, the host compound may be one type or two or more types. As the host compound, all known ones may be used. Preferred examples of the host compound include the high T1 compounds described later.

[0186] The light-emitting layer may be either a single layer or a plurality of layers. Also, the host compound, the emitting dopant material, and the assist dopant material may be contained in the same layer, or at least one component may be contained in a plurality of layers. The host compound and the dopant material (emitting dopant or assist dopant) contained in the light-emitting layer may each be one type or a plurality of combinations. The assist dopant and the emitting dopant may be entirely or partially contained in the host compound as a matrix.

[0187] The amount of the host material used varies depending on the type of the host material and may be determined according to the characteristics of the host material. The standard for the amount of the host material used is preferably 50% by mass to 99.999% by mass of the total material for the light-emitting layer, more preferably 80% by mass to 99.95% by mass, and still more preferably 90% by mass to 99.9% by mass.

[0188] The amount of dopant material used varies depending on the type of dopant material and may be determined according to the characteristics of the dopant material. The standard for the amount of dopant used is preferably 0.001% to 50% by mass, more preferably 0.05% to 20% by mass, and even more preferably 0.1% to 10% by mass of the total material for the light-emitting layer. Within the above range, for example, it is preferable in terms of preventing the concentration quenching phenomenon.

[0189] On the other hand, in an organic electroluminescent device using a TADF material as a dopant material, it is preferable that the amount of dopant material used is low in terms of preventing the concentration quenching phenomenon, but it is preferable that the amount of dopant material used is high from the viewpoint of the efficiency of the thermally activated delayed fluorescence mechanism. Further, in an organic electroluminescent device using a TADF material as an assist dopant, from the viewpoint of the efficiency of the thermally activated delayed fluorescence mechanism of the assist dopant, it is preferable that the amount of emitting dopant used is lower in concentration than the amount of assist dopant used.

[0190] When an assist dopant material is used, the standards for the amounts of host material, assist dopant, and emitting dopant are 40% to 99% by mass, 59% to 1% by mass, and 20% to 0.001% by mass, respectively, of the total material for the light-emitting layer, preferably 60% to 95% by mass, 39% to 5% by mass, and 10% to 0.01% by mass, respectively, and more preferably 70% to 90% by mass, 29% to 10% by mass, and 5% to 0.05% by mass, respectively. When an assist dopant material is used, an exciplex may be formed between the host material or the emitting dopant material and the assist dopant.

[0191] 3-1-5-1. Dopant material The polycyclic aromatic compound represented by formula (1) is preferably used as a dopant material.

[0192] In addition to the polycyclic aromatic compound represented by formula (1), the dopant material that can be used is not particularly limited, and known compounds may be used, or various materials may be selected according to the desired emission color.Specifically, for example, condensed ring derivatives such as phenanthrene, anthracene, pyrene, tetracene, pentacene, perylene, naphthopyrene, dibenzopyrene, rubrene, and chrysene; benzoxazole derivatives, benzothiazole derivatives, benzimidazole derivatives, benzotriazole derivatives, oxazole derivatives, oxadiazole derivatives, thiazole derivatives, imidazole derivatives, thiadiazole derivatives, triazole derivatives, pyrazoline derivatives, stilbene derivatives, thiophene derivatives, tetraphenylbutadiene derivatives, cyclopentadiene derivatives, bisstilbene derivatives such as bisstyrylanthracene derivatives and distyrylbenzene derivatives (Japanese Patent Laid-Open No. 1-245087), bisstyrylarylene derivatives (Japanese Patent Laid-Open No. 2-247278), diazaindacene derivatives, furan derivatives, benzofuran derivatives, phenylisobenzofuran, dimethylisobenzofuran, di(2-methylphenyl)isobenzofuran, di(2-trifluoromethylphenyl)isobenzofuran, isobenzofuran derivatives such as phenylisobenzofuran; dibenzofuran derivatives; 7-dialkylaminocoumarin derivatives, 7-piperidinecoumarin derivatives, 7-hydroxycoumarin derivatives, 7-methoxycoumarin derivatives, 7-acetoxycoumarin derivatives, 3-benzothiazolylcoumarin derivatives, 3-benzimidazolylcoumarin derivatives, 3-benzoxazolylcoumarin derivatives and other coumarin derivatives; dicyanomethylene pyran derivatives, dicyanomethylthiopyran derivatives, polymethine derivatives, cyanine derivatives, oxobenzoanthracene derivatives, xanthene derivatives, rhodamine derivatives, fluorescein derivatives, pyrylium derivatives, carbostyryl derivatives, acridine derivatives, oxazine derivatives, phenylene oxide derivatives, quinacridone derivatives, quinazoline derivatives, pyrrolopyridine derivatives, furopyridine derivatives, 1,2,5-thiadiazolopyrene derivatives, pyrromethene derivatives, perinone derivatives, pyrrolopyrrole derivatives, squarylium derivatives, violanthrone derivatives, phenazine derivatives, acridone derivatives, deazaflavin derivatives, fluorene derivatives, and benzofluorene derivatives, etc. can be mentioned.

[0193] Illustrated for each color-emitting light, examples of blue to blue-green dopant materials include aromatic hydrocarbon compounds such as naphthalene, anthracene, phenanthrene, pyrene, triphenylene, perylene, fluorene, indene, chrysene and their derivatives, aromatic heterocyclic compounds such as furan, pyrrole, thiophene, silole, 9-silafluorene, 9,9'-spirobisilafluorene, benzothiophene, benzofuran, indole, dibenzothiophene, dibenzofuran, imidazopyridine, phenanthroline, pyrazine, naphthyridine, quinoxaline, pyrrolopyridine, thioxanthene and their derivatives, distyrylbenzene derivatives, tetraphenylbutadiene derivatives, stilbene derivatives, aldazine derivatives, coumarin derivatives, azole derivatives such as imidazole, thiazole, thiadiazole, carbazole, oxazole, oxadiazole, triazole and their metal complexes, and aromatic amine derivatives represented by N,N'-diphenyl-N,N'-di(3-methylphenyl)-4,4'-diphenyl-1,1'-diamine and the like.

[0194] In addition, 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. Compounds obtained by further introducing substituents that enable longer wavelengths, such as aryl, heteroaryl, arylvinyl, amino, and cyano, into the compounds exemplified as the blue to blue-green dopant materials are also preferred examples.

[0195] Furthermore, examples of the orange to red dopant materials include naphthalimide derivatives such as bis(diisopropylphenyl)perylenetetracarboxylic acid imide, perinone derivatives, rare earth complexes such as Eu complexes having acetylacetone, benzoylacetone, and phenanthroline as ligands, 4-(dicyanomethylene)-2-methyl-6-(p-dimethylaminostyryl)-4H-pyran and its analogs, metal phthalocyanine derivatives such as magnesium phthalocyanine and aluminum chlorophthalocyanine, rhodamine compounds, deazaf lavin derivatives, coumarin derivatives, quinacridone derivatives, phenoxazine derivatives, oxazine derivatives, quinazoline derivatives, pyrrolopyridine derivatives, squarylium derivatives, violanthrone derivatives, phenazine derivatives, phenoxazone derivatives, and thiadiazolopyrene derivatives. Compounds in which substituents enabling longer wavelengths, such as aryl, heteroaryl, arylvinyl, amino, and cyano, are further introduced into the compounds exemplified as the blue to blue-green and green to yellow dopant materials are also preferable examples.

[0196] In addition, as the dopant, it may be appropriately selected and used from compounds described in Chemical Industry, June 2004 issue, page 13, and the literature cited therein.

[0197] Among the above dopant materials, amines having a stilbene structure, perylene derivatives, borane derivatives, aromatic amine derivatives, coumarin derivatives, pyran derivatives, or pyrene derivatives are particularly preferable.

[0198] The amine having a stilbene structure is represented by, for example, the following formula.

Chemical formula

[0199] In the formula, Ar 1 is an m-valent group derived from an aryl having 6 to 30 carbon atoms, and Ar 2 and Ar 3 are each independently an aryl having 6 to 30 carbon atoms, but Ar 1~Ar 3 At least one of them has a stilbene structure, and Ar 1 ~Ar 3 may be substituted with aryl, heteroaryl, alkyl, cycloalkyl, trisubstituted silyl (silyl trisubstituted with aryl, alkyl and / or cycloalkyl), or cyano, and m is an integer from 1 to 4.

[0200] The amine having a stilbene structure is more preferably a diamino stilbene represented by the following formula.

Chemical formula

[0201] In the formula, Ar 2 and Ar 3 are each independently an aryl having 6 to 30 carbon atoms, and Ar 2 and Ar 3 may be substituted with aryl, heteroaryl, alkyl, cycloalkyl, trisubstituted silyl (silyl trisubstituted with aryl, alkyl and / or cycloalkyl), or cyano.

[0202] Specific examples of the aryl having 6 to 30 carbon atoms include phenyl, naphthyl, acenaphthylenyl, fluorenyl, phenalenyl, phenanthrenyl, anthryl, fluoranthenyl, triphenylenyl, pyrenyl, chrysenyl, naphthacenyl, perylenyl, stilbenyl, distyrylphenyl, distyryl biphenyl, distyrylfluorenyl and the like.

[0203] Specific examples of the amine having a stilbene structure include N,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(9-phenanthryl)-N,N’-diphenyl-4,4’-diaminostilbene, 4,4’-bis[4”-bis(diphenylamino)stil]-biphenyl, 1,4-bis[4’-bis(diphenylamino)stil]-benzene, 2,7-bis[4’-bis(diphenylamino)stil]-9,9-dimethylfluorene, 4,4’-bis(9-ethyl-3-carbazovinylene)-biphenyl, 4,4’-bis(9-phenyl-3-carbazovinylene)-biphenyl, and the like.

[0204] In addition, amines having a stilbene structure described in JP-A-2003-347056 and JP-A-2001-307884 may also be used.

[0205] Examples of the perylene derivative 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, 3,3’-bis(8,11-di(t-butyl)perylenyl), and the like.

[0206] In addition, perylene derivatives described in JP-A-11-97178, JP-A-2000-133457, JP-A-2000-26324, JP-A-2001-267079, JP-A-2001-267078, JP-A-2001-267076, JP-A-2000-34234, JP-A-2000-267075, and JP-A-2001-217077 may also be used.

[0207] Examples of the borane derivative include 1,8-diphenyl-10-(dimethylboranyl)anthracene, 9-phenyl-10-(dimethylboranyl)anthracene, 4-(9'-anthryl)dimethylborolylnaphthalene, 4-(10'-phenyl-9'-anthryl)dimethylborolylnaphthalene, 9-(dimethylboranyl)anthracene, 9-(4'-biphenylyl)-10-(dimethylboranyl)anthracene, 9-(4'-(N-carbazolyl)phenyl)-10-(dimethylboranyl)anthracene, and the like.

[0208] Alternatively, a borane derivative described in International Publication No. 2000 / 40586 or the like may be used.

[0209] The aromatic amine derivative is represented by, for example, the following formula. [Chemical formula]

[0210] In the formula, Ar 4 is an n-valent group derived from an aryl having 6 to 30 carbon atoms, Ar 5 and Ar 6 are each independently an aryl having 6 to 30 carbon atoms, and Ar 4 to Ar 6 may be substituted with aryl, heteroaryl, alkyl, cycloalkyl, trisubstituted silyl (silyl trisubstituted with aryl, alkyl and / or cycloalkyl), or cyano, and n is an integer of 1 to 4.

[0211] In particular, Ar 4 is a divalent group derived from anthracene, chrysene, fluorene, benzofluorene, or pyrene, Ar 5 and Ar 6 are each independently an aryl having 6 to 30 carbon atoms, and Ar 4 to Ar 6An aromatic amine derivative which may be substituted with aryl, heteroaryl, alkyl, cycloalkyl, trisubstituted silyl (silyl trisubstituted with aryl, alkyl and / or cycloalkyl), or cyano, and n is 2, is more preferable.

[0212] Specific examples of aryl having 6 to 30 carbon atoms include phenyl, naphthyl, acenaphthylenyl, fluorenyl, phenalenyl, phenanthrenyl, anthryl, fluoranthenyl, triphenylenyl, pyrenyl, chrysenyl, naphthacenyl, perylenyl, pentacenyl and the like.

[0213] Examples of the aromatic amine derivative include, as the chrysene type, for example, 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(naphthalen-2-yl)chrysene-6,12-diamine, N,N'-diphenyl-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, N,N'-bis(4-isopropylphenyl)-N,N'-di(p-tolyl)chrysene-6,12-diamine and the like.

[0214] As for pyrene-based compounds, 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’,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 -bis-(4-trimethylsilyl-phenyl)-1H,8H-pyrene-1,6-diamine and the like can be mentioned.

[0215] As for anthracene-based compounds, 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, 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, 2,6-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)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, 10-diphenylamino-9-(6-diphenylamino-2-naphthyl)anthracene, etc. can be mentioned.

[0216] Alternatively, other examples include [4-(4-diphenylamino-phenyl)naphthalen-1-yl]-diphenylamine, [6-(4-diphenylamino-phenyl)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, 4,4''-bis[6-diphenylaminonaphthalen-2-yl]-p-terphenyl, and the like.

[0217] Also, aromatic amine derivatives described in Japanese Patent Application Laid-Open No. 2006-156888 and the like may be used.

[0218] Examples of coumarin derivatives include coumarin-6, coumarin-334, and the like.

[0219] Also, coumarin derivatives described in Japanese Patent Application Laid-Open No. 2004-43646, Japanese Patent Application Laid-Open No. 2001-76876, Japanese Patent Application Laid-Open No. 6-298758, and the like may be used.

[0220] Examples of pyran derivatives include the following DCM, DCJTB, and the like.

Chemical formula

[0221] Also, pyran derivatives described in Japanese Patent Application Laid-Open No. 2005-126399, Japanese Patent Application Laid-Open No. 2005-097283, Japanese Patent Application Laid-Open No. 2002-234892, Japanese Patent Application Laid-Open No. 2001-220577, Japanese Patent Application Laid-Open No. 2001-081090, Japanese Patent Application Laid-Open No. 2001-052869, and the like may be used.

[0222] As the dopant material, the following compounds may also be used.

Chemical formula

[0223] 3-1-5-2. High T1 compound An organic electroluminescent device containing at least one polycyclic aromatic compound represented by the formula (1) in the light-emitting layer preferably further contains at least one high T1 compound having a lowest excited triplet energy level (ET1) (sometimes referred to as "T1 energy") that is at least 0.01 eV higher than the lowest excited triplet energy level of the polycyclic aromatic compound represented by the formula (1) in the light-emitting layer or an organic layer adjacent to the light-emitting layer.

[0224] The high T1 compound may be used, for example, as a host compound when the polycyclic aromatic compound represented by the formula (1) is used as a dopant compound in the light-emitting layer. The high T1 compound may be contained in one kind or two or more kinds in the light-emitting layer. When two or more kinds are contained, it preferably contains a hole-transporting host material and an electron-transporting host material that satisfy the following relationship.

[0225] The HOMO (Highest Occupied Molecular Orbital) of the hole-transporting host material (HH) is shallower than the HOMO of the electron-transporting host material (EH), and the LUMO (Lowest UNoccupied Molecular Orbital) of the electron-transporting host material (EH) is deeper than the LUMO of the hole-transporting host material (HH).

[0226] The E of the high T1 compound T1 is more preferably at least 0.03 eV higher and even more preferably at least 0.1 eV higher than the E of the polycyclic aromatic compound represented by the formula (1). T1

[0227] As the high-T1 compound, a compound is preferred which has at least one partial structure selected from the partial structure group A, or has at least two partial structures selected from the partial structure group A and the partial structure group B, and may further have at least one partial structure selected from the partial structure group C as a linking group or a substituent. On the other hand, at least one of the following structures is bonded to another partial structure other than hydrogen at *, and the other * is bonded to hydrogen. As can be seen from the following structural formula, the carbon-carbon bond connecting benzene rings in each partial structure and the bond connecting partial structures are in the ortho position or the meta position. At this time, high T1 and high charge mobility can be obtained. From the viewpoint of high T1, bonding at the ortho position is preferred, and from the viewpoint of high charge mobility, bonding at the meta position is preferred.

[0228] Partial structure group A

Chem.

[0229] Partial structure group B

Chem.

[0230] Partial structure group C

Chem.

[0231] The partial structure group A is preferably the partial structure group Aa, the partial structure group B is preferably the partial structure group Bb, and the partial structure group C is preferably the partial structure group Cc.

Chem.

[0232] Examples of the high-T1 compound include a compound represented by the following formula (H1), a compound represented by the following formula (H3), a compound containing a structure represented by the following formula (H4), a compound represented by the following formula (H5), a compound represented by the following formula (H6), and a compound represented by the following formula (H8).

Chem.

[0233] 3-1-5-2-1. Compound represented by formula (H1)

Chem.

[0234] In formula (H1), L 1 is an arylene having 6 to 24 carbon atoms or a heteroarylene having 5 to 23 carbon atoms, preferably an arylene having 6 to 16 carbon atoms and a heteroarylene having 5 to 15 carbon atoms, more preferably an arylene having 6 to 12 carbon atoms and / or a heteroarylene having 5 to 11 carbon atoms, particularly preferably an arylene having 6 to 10 carbon atoms or a heteroarylene having 5 to 9 carbon atoms. Specifically, divalent or trivalent groups such as a benzene ring, a biphenyl ring, a terphenyl ring, a fluorene ring, a spirofluorene ring, a phenalene ring, a triphenylene ring, a pyridine ring, a pyrimidine ring, a triazine ring, a biphenylpyridine ring, a biphenylpyrimidine ring, and a biphenyltriazine ring can be mentioned.

[0235] At least one hydrogen in the compound represented by formula (H1) may be substituted with an alkyl having 1 to 6 carbon atoms, a cycloalkyl having 3 to 14 carbon atoms, cyano, halogen, or deuterium.

[0236]

Chem.

[0237] 3-1-5-2-2. Compound represented by formula (H3)

Chem.

[0238] In formula (H3), MU is each independently a divalent aromatic group, EC is each independently a monovalent aromatic group, and k is an integer of 2 to 50000.

[0239] More specifically, MU is each independently arylene, heteroarylene, diarylene arylamino, diarylene arylboryl, oxaborin-diyl, or azaborin-diyl, EC is each independently hydrogen, aryl, heteroaryl, diaryl amino, diheteroaryl amino, aryl heteroaryl amino, or aryloxy, At least one hydrogen in MU and EC may be further substituted with aryl, heteroaryl, diaryl amino, alkyl, and cycloalkyl, k is an integer of 2 to 50000.

[0240] k is preferably an integer of 20 to 50000, and more preferably an integer of 100 to 50000.

[0241] At least one hydrogen in MU and EC in formula (H3) may be substituted with alkyl having 1 to 24 carbon atoms, cycloalkyl having 3 to 24 carbon atoms, halogen, or deuterium. Any -CH2- in the alkyl may be further substituted with -O- or -Si(CH3)2-. Any -CH2- in the alkyl except for the -CH2- directly bonded to EC in formula (H3) may be substituted with arylene having 6 to 24 carbon atoms. Any hydrogen in the alkyl may be substituted with fluorine.

[0242] Examples of MU include divalent derivatives having the following structures (for example, a divalent group represented by removing any two hydrogen atoms from any one 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 one of the following compounds, a divalent group in which at least one of the hydrogens in these groups is substituted with alkyl, etc.).

[0243]

Chem.

[0244] More specifically, examples include divalent groups having any one of the following structures. In these, MU binds to another MU or EC at the *.

[0245]

Chem.

[0246]

Chem.

[0247]

Chem.

[0248]

Chem.

[0249]

Chem.

[0250]

Chem.

[0251]

Chem.

[0252] In addition, examples of the EC include a group represented by the following formula. In these, the EC binds to the MU at the *.

[0253]

Chemical formula

[0254]

Chemical formula

[0255] From the viewpoints of solubility and coating film-forming property, it is preferable that 10% to 100% of the total number (k) of MUs in the molecule have an alkyl group having 1 to 24 carbon atoms, more preferably 30% to 100% of the total number (k) of MUs in the molecule have an alkyl group having 1 to 18 carbon atoms (branched alkyl group having 3 to 18 carbon atoms), and still more preferably 50% to 100% of the total number (k) of MUs in the molecule have an alkyl group having 1 to 12 carbon atoms (branched alkyl group having 3 to 12 carbon atoms). On the other hand, from the viewpoints of in-plane orientation and charge transport, it is preferable that 10% to 100% of the total number (k) of MUs in the molecule have an alkyl group having 7 to 24 carbon atoms, and more preferably 30% to 100% of the total number (k) of MUs in the molecule have an alkyl group having 7 to 24 carbon atoms (branched alkyl group having 7 to 24 carbon atoms).

[0256] 3-1-5-2-3. Compound containing structure represented by formula (H4) The compound containing the structure represented by the formula (H4) contains a plurality of structures represented by the formula (H4), preferably 1 to 5, more preferably 1 to 3, still more preferably 1 to 2, and most preferably 1. When a plurality of them are contained, the structures are bonded to each other directly by a single bond or by a specific linking group.

[0257]

Chemical formula

[0258] In formula (H4), G is "=C(-H)-" or "=N-", and H in the "=C(-H)-" may be substituted with a substituent or a structure represented by another formula (H4).

[0259] As the compound containing the structure represented by formula (H4), for example, the compounds described in International Publication No. WO2012 / 153780 and International Publication No. WO2013 / 038650 may be used, and they can be produced according to the methods described in the above-mentioned documents.

[0260] Examples of the substituent when H in "=C(-H)-" which is G is substituted include aryl, heteroaryl, substituted silyl, substituted phosphine oxide group, and substituted carboxy, etc.

[0261] Specific examples of the "aryl" which is a substituent include phenyl, tolyl, xylyl, triphenylenyl, fluorenyl, 9,9-dimethylfluorenyl, benzofluorenyl, dibenzofluorenyl, biphenylyl, terphenylyl, quarterphenylyl, etc., preferably phenyl, biphenylyl, terphenylyl, fluorenyl, etc. Examples of the aryl having a substituent include tolyl, xylyl, 9,9-dimethylfluorenyl, etc. As shown in the specific examples, aryl includes both condensed aryl and non-condensed aryl.

[0262] Specific examples of the "heteroaryl" which is a substituent include pyrrolyl, pyrazolyl, pyrazinyl, pyrimidinyl, pyridazinyl, pyridyl, triazinyl, indolyl, isoindolyl, imidazolyl, benzimidazolyl, indazolyl, imidazo[1,2-a]pyridinyl, furyl, benzofuranyl, isobenzofuranyl, dibenzofuranyl, azadibenzofuranyl, thienyl, benzothienyl, dibenzothienyl, azadibenzothienyl, quinolyl, isoquinolyl, quinoxalinyl, quinazolinyl, naphthyridinyl, carbazolyl, azacarbazolyl, phenanthridinyl, acridinyl, phenazinyl, phenothiazinyl, phenoxazinyl, oxazolyl, oxadiazolyl, furazanyl, benzoxazolyl, thiazolyl, thiadiazolyl, benzothiazolyl, triazolyl, tetrazolyl, etc. Preferably, dibenzofuranyl, dibenzothienyl, carbazolyl, pyridyl, pyrimidinyl, triazinyl, azadibenzofuranyl, and azadibenzothienyl, etc. are included. Dibenzofuranyl, dibenzothienyl, azadibenzofuranyl, or azadibenzothienyl is more preferable.

[0263] The "substituted silyl" which is a substituent is preferably a group selected from the group consisting of substituted or unsubstituted trialkylsilyl, substituted or unsubstituted arylalkylsilyl, and substituted or unsubstituted triarylsilyl.

[0264] Specific examples of the substituted or unsubstituted trialkylsilyl include trimethylsilyl and triethylsilyl. Specific examples of the substituted or unsubstituted arylalkylsilyl include diphenylmethylsilyl, ditolylmethylsilyl, and phenyldimethylsilyl, etc. Specific examples of the substituted or unsubstituted triarylsilyl include triphenylsilyl and tritolylsilyl, etc.

[0265] The "substituted phosphine oxide group" which is a substituent is preferably a substituted or unsubstituted diarylphosphine oxide group. Specific examples of the substituted or unsubstituted diarylphosphine oxide group include diphenylphosphine oxide and ditolylphosphine oxide.

[0266] Examples of the "substituted carboxy" which is a substituent include benzoyloxy.

[0267] Examples of the linking group that links a plurality of structures represented by formula (H4) include divalent to tetravalent, divalent to trivalent, or divalent derivatives of the aforementioned aryl and heteroaryl.

[0268] Specific examples of the compound containing the structure represented by formula (H4) are shown below.

Chemical formula

[0269]

Chemical formula

[0270] 3-1-5-2-4. Compound represented by formula (H5) and compound represented by formula (H6) 3-1-5-2-4-1. Compound represented by formula (H5)

Chemical formula

[0271] In formula (H5), R 1 ~R 11 are each 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.

[0272] Also, any at least one (preferably 1 to 3) of -C(R n)=(N ranges from 1 to 11) may be replaced with -N=.

[0273] At least one hydrogen in the compound represented by formula (H5) may be further substituted with an alkyl having 1 to 24 carbon atoms, any -CH2- in the alkyl may be further substituted with -O- or -Si(CH3)2-, and any -CH2- in the alkyl excluding the -CH2- directly bonded to the compound represented by formula (H5) may be substituted with an arylene having 6 to 24 carbon atoms, and any hydrogen in the alkyl may be substituted with fluorine.

[0274] Also, at least one hydrogen in the compound represented by formula (H5) may be substituted with a halogen or deuterium.

[0275] 3-1-5-2-4-2. Compound represented by formula (H6) [Chemical formula]

[0276] In formula (H6), R 1 ~R 16 are each 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.

[0277] Also, at least one hydrogen in the compound represented by formula (H-6) may be substituted with an alkyl having 1 to 24 carbon atoms, any -CH2- in the alkyl may be further substituted with -O- or -Si(CH3)2-, and any -CH2- in the alkyl excluding the -CH2- directly bonded to the compound represented by formula (H6) may be substituted with an arylene having 6 to 24 carbon atoms, and any hydrogen in the alkyl may be substituted with fluorine.

[0278] Further, at least one hydrogen in the compound represented by formula (H6) may be substituted with a halogen or deuterium.

[0279] 3-1-5-2-4-3. "R in formula (H5)" 1 ~R 11 " and "R in formula (H6)" 1 ~R 16 」 "R 1 ~R 11 " in formula (H5) and "R 1 ~R 16 " in formula (H6) are each independently hydrogen, aryl, heteroaryl, diarylamino, diheteroarylamino, arylheteroarylamino, or aryloxy, and are preferably aryl having 6 to 30 carbon atoms, heteroaryl having 2 to 30 carbon atoms, diarylamino (amino having two aryls each having 6 to 30 carbon atoms), diheteroarylamino (amino having two heteroaryls each having 2 to 30 carbon atoms), arylheteroarylamino (amino having an aryl having 6 to 30 carbon atoms and a heteroaryl having 2 to 30 carbon atoms), or aryloxy having 6 to 30 carbon atoms.

[0280] Examples of the "aryl", the aryl of "diarylamino", the aryl of "arylheteroarylamino", and the aryl of "aryloxy" include a monocyclic benzene ring, a bicyclic biphenyl ring, a condensed bicyclic naphthalene ring, a tricyclic terphenyl ring (m-terphenyl, o-terphenyl, p-terphenyl), a condensed tricyclic acenaphthylene ring, a fluorene ring, a phenalene ring, a phenanthrene ring, a condensed tetracyclic triphenylene ring, a pyrene ring, a naphthacene ring, a condensed pentacyclic perylene ring, a pentacene ring, and the like. Further, as will be described later, those in which the heteroaryl defined below is substituted on these aryls are also defined as aryl in formulas (H5) and (H6).

[0281] Examples of the "heteroaryl", the heteroaryl of "diheteroarylamino", and the heteroaryl of "arylheteroarylamino" include, for example, a pyrrole ring, an oxazole ring, an isoxazole ring, a thiazole ring, an isothiazole ring, an imidazole ring, an oxadiazole ring, a thiadiazole ring, a triazole ring, a tetrazole ring, a pyrazole ring, a pyridine ring, a pyrimidine ring, a pyridazine ring, a pyrazine ring, a triazine ring, an indole ring, an isoindole ring, a 1H-indazole ring, a benzimidazole ring, a benzoxazole ring, a benzothiazole ring, a 1H-benzotriazole ring, a quinoline ring, an isoquinoline ring, a cinnoline ring, a quinazoline ring, a quinoxaline ring, a phthalazine ring, a naphthyridine ring, a purine ring, a pteridine ring, a carbazole ring, an acridine ring, a phenoxathiin ring, a phenoxazine ring, a phenothiazine ring, a phenazine ring, an indolizine ring, a furan ring, a benzofuran ring, an isobenzofuran ring, a dibenzofuran ring, a thiophene ring, a benzothiophene ring, a dibenzothiophene ring, a furazan ring, an oxadiazole ring, a thianthrene ring, and a monovalent group such as the heteroaryl substituted with N-aryl. Further, as described later, those in which the aryl defined above is substituted on these heteroaryls are also defined as heteroaryl in Formula (H5) and Formula (H6).

[0282] Further, R in Formula (H5) 1 ~R 11 or R in Formula (H6) 1 ~R 16 The aryl, heteroaryl, diarylamino, diheteroarylamino, arylheteroarylamino, or aryloxy described as such may have at least one hydrogen in these further substituted with aryl, heteroaryl, or diarylamino. Examples of the aryl, heteroaryl, or diarylamino for such substitution include those as described in the columns of R 1 ~R 11 and R 1 ~R 16 as described above.

[0283] R 1 ~R11 or R 1 ~R 16 Specific examples of the group include, for example, groups represented by the following formulas (RG-1) to (RG-10). Further, the groups represented by the following formulas (RG-1) to (RG-10) are bonded to the a-ring to d-ring in formula (H5) or formula (H6) with a *.

Chemical formula

[0284] Referring to the above specific groups, the "aryl" and "heteroaryl" defined in formula (H5) and formula (H6) will be described. Formula (RG-1), formula (RG-4), and formula (RG-7) are aryl, formula (RG-2), formula (RG-3), and formula (RG-6) are heteroaryl, formula (RG-9) is heteroaryl-substituted heteroaryl, and formula (RG-10) is heteroaryl-substituted aryl. Further, formula (RG-5) is aryl (phenyl) substituted with diarylamino (diphenylamino), and formula (RG-8) is diarylamino (diphenylamino).

[0285]

Chemical formula

[0286] 3-1-5-2-4-4. Specific examples of compounds The more specific structures of the compounds represented by formula (H5) or formula (H6) are shown below.

[0287] The specific structures of the compounds represented by the following formula (H5) or formula (H6) may be substituted with alkyl having 1 to 24 carbon atoms.

Chemical formula

[0288]

Chemical formula

[0289] [Chemistry]

[0290] [Chemistry]

[0291] [Chemistry]

[0292] [Chemistry]

[0293] [Chemistry]

[0294] [Chemistry]

[0295] [Chemistry]

[0296] [Chemistry]

[0297] [Chemistry]

[0298] [Chemistry]

[0299] [Chemistry]

[0300]

Chem.

[0301]

Chem.

[0302]

Chem.

[0303]

Chem.

[0304]

Chem.

[0305]

Chem.

[0306]

Chem.

[0307]

Chem.

[0308]

Chem.

[0309]

Chem.

[0310] [Chemistry]

[0311] [Chemistry]

[0312] [Chemistry]

[0313] 3-1-5-2-4-5. Method for producing compound represented by formula (H5) or formula (H6) For the compound represented by formula (H5), an intermediate can be produced by first bonding rings a to c with a bonding group (-O-) (first reaction), and then the final product can be produced by bonding rings a to c with a bonding group (a group containing B) (second reaction). Also, for the compound represented by formula (H6), an intermediate can be produced by first bonding rings a to d with a bonding group (>NH or single bond) (first reaction), and then the final product can be produced by bonding rings a to d with a bonding group (a group containing B) (second reaction). In the first reaction, for example, in the case of an etherification reaction, general reactions such as nucleophilic substitution reactions and Ullmann reactions can be used, and in the case of an amination reaction, general reactions such as the Buchwald-Hartwig reaction can be used. Also, in the second reaction, a tandem hetero Friedel-Crafts reaction (successive aromatic electrophilic substitution reaction, the same applies hereinafter) can be used.

[0314] <Manufacturing method: Example of the second reaction of the compound represented by formula (H5)> The second reaction is a reaction for introducing B (boron) that connects the a-ring, b-ring, and c-ring as shown in the following Scheme (1). As an example, the case of the compound represented by the formula (H5) is shown below. First, the hydrogen atom between the two Os is orthometalated with n-butyllithium, sec-butyllithium, t-butyllithium, or the like. Next, boron trichloride, boron tribromide, or the like is added, and after performing metal exchange between lithium and boron, a Brønsted base such as N,N-diisopropylethylamine is added to cause a tandem borofriedel-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.

[0315]

Chem.

[0316] In the said scheme, lithium was introduced to the desired position by orthometalation. However, as shown in the following Scheme (2), a bromine atom or the like can be introduced at the position where lithium is to be introduced, and lithium can also be introduced to the desired position by halogen-metal exchange.

[0317]

Chem.

[0318] By appropriately selecting the said synthesis method and also appropriately selecting the raw materials to be used, a compound having a substituent at the desired position and represented by the formula (H-5) can be synthesized.

[0319] <Manufacturing method: Example of the manufacturing method of the compound represented by the formula (H6)> Regarding the method for producing the compound represented by formula (H6), the first reaction and the second reaction in the method for producing the compound represented by formula (H5) can also be applied. That is, the second reaction is a reaction for introducing B (boron) that binds NH to ring c and ring d. After orthometalating the hydrogen atom of NH with n-butyllithium, sec-butyllithium, or t-butyllithium, etc., boron trichloride, boron tribromide, etc. are added to perform a metal exchange of lithium-boron, and a Brønsted base such as N,N-diisopropylethylamine is further added to cause a tandem bora-Friedel-Crafts reaction to obtain the target product. Here too, in the second reaction, a Lewis acid such as aluminum trichloride may be added to accelerate the reaction.

[0320] 3-1-5-2-5. Compound containing structure represented by formula (H8) The compound containing the structure represented by formula (H8) contains a plurality of structures represented by formula (H8), preferably 1 to 5, more preferably 1 to 3, still more preferably 1 to 2, and most preferably 1. When a plurality of them are contained, the structures are bonded to each other directly by a single bond or by a specific linking group.

[0321]

Chemical formula

[0322] In formula (H8), Z is "=C(-H)-" or "=N-", and the H in the "=C(-H)-" may be substituted with a structure represented by a substituent.

[0323] Examples of the substituent when the H in "=C(-H)-" which is Z is substituted include aryl, heteroaryl, substituted silyl, substituted phosphine oxide group, and substituted carboxy, etc.

[0324] Specific examples of the substituent "aryl" include phenyl, tolyl, xylyl, triphenylenyl, fluorenyl, 9,9-dimethylfluorenyl, benzofluorenyl, dibenzofluorenyl, biphenylyl, terphenylyl, quaterphenylyl, etc., preferably phenyl, biphenylyl, terphenylyl, fluorenyl, etc. Examples of aryl having a substituent include tolyl, xylyl, 9,9-dimethylfluorenyl, etc. As can be seen from the specific examples, aryl includes both condensed aryl and non-condensed aryl.

[0325] Specific examples of the substituent "heteroaryl" include pyrrolyl, pyrazolyl, pyrazinyl, pyrimidinyl, pyridazinyl, pyridyl, triazinyl, indolyl, isoindolyl, imidazolyl, benzimidazolyl, indazolyl, imidazo[1,2-a]pyridinyl, furyl, benzofuranyl, isobenzofuranyl, dibenzofuranyl, azadibenzofuranyl, thienyl, benzothienyl, dibenzothienyl, azadibenzothienyl, quinolyl, isoquinolyl, quinoxalinyl, quinazolinyl, naphthyridinyl, carbazolyl, azacarbazolyl, phenanthridinyl, acridinyl, phenazinyl, phenothiazinyl, phenoxazinyl, oxazolyl, oxadiazolyl, furazanyl, benzoxazolyl, thiazolyl, thiadiazolyl, benzothiazolyl, triazolyl, tetrazolyl, etc., preferably dibenzofuranyl, dibenzothienyl, carbazolyl, pyridyl, pyrimidinyl, triazinyl, azadibenzofuranyl, and azadibenzothienyl, etc. Dibenzofuranyl, dibenzothienyl, azadibenzofuranyl, or azadibenzothienyl is more preferable.

[0326] The substituent "substituted silyl" is preferably a group selected from the group consisting of substituted or unsubstituted trialkylsilyl, substituted or unsubstituted arylalkylsilyl, and substituted or unsubstituted triarylsilyl.

[0327] Specific examples of the substituted or unsubstituted trialkylsilyl include trimethylsilyl and triethylsilyl. Specific examples of the substituted or unsubstituted arylalkylsilyl include diphenylmethylsilyl, ditolylmethylsilyl, and phenyldimethylsilyl. Specific examples of the substituted or unsubstituted triarylsilyl include triphenylsilyl and tritolylsilyl.

[0328] The substituent "substituted phosphine oxide group" is preferably a substituted or unsubstituted diarylphosphine oxide group. Specific examples of the substituted or unsubstituted diarylphosphine oxide group include diphenylphosphine oxide and ditolylphosphine oxide.

[0329] Examples of the substituent "substituted carboxy" include benzoyloxy.

[0330] Examples of the linking group that links a plurality of structures represented by the formula (H8) include divalent to tetravalent, divalent to trivalent, or divalent derivatives of the aryl or heteroaryl.

[0331] Specific examples of the compound containing the structure represented by the formula (H8) are shown below.

Chemical formula

[0332]

Chemical formula

[0333] 3-1-5-2-6. TADF material The high T1 compound may be a TADF material. In this specification, the TADF material means 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, reverse energy transfer from the excited triplet state, which usually has a low transition probability, to the excited singlet state occurs with high efficiency, resulting in luminescence from the singlet state (thermally activated delayed fluorescence, TADF). In normal fluorescence emission, 75% of the triplet excitons generated by current excitation pass through the thermal deactivation pathway and thus cannot be extracted as fluorescence. On the other hand, in TADF, all excitons can be utilized for fluorescence emission, enabling the realization of highly efficient organic EL elements.

[0334] The TADF material is preferably a donor-acceptor type TADF compound (D-A type TADF compound) designed to localize the HOMO and LUMO in the molecule using an electron-donating substituent called a donor and an electron-accepting substituent called an acceptor, so that efficient reverse intersystem crossing occurs.

[0335] Here, in this specification, the "electron-donating substituent" (donor) means a substituent and partial structure in which the HOMO orbital is localized in the TADF compound molecule, and the "electron-accepting substituent" (acceptor) means a substituent and partial structure in which the LUMO orbital is localized in the TADF compound molecule.

[0336] Generally, TADF compounds using donors or acceptors have a large spin-orbit coupling (SOC) due to their structure, a small exchange interaction between the HOMO and LUMO, and a small ΔE ST Since it is small, a very fast reverse intersystem crossing rate can be obtained. On the other hand, TADF compounds using donors or acceptors have a large structural relaxation in the excited state (in some molecules, since the stable structures are different between the ground state and the excited state, when the conversion from the ground state to the excited state occurs due to an external stimulus, the structure then changes to the stable structure in the excited state), giving a broad emission spectrum, and thus may reduce the color purity when used as a luminescent material.

[0337] However, by simultaneously using the polycyclic aromatic compound represented by formula (1), the polycyclic aromatic compound represented by formula (1) functions as an emitting dopant, and the TADF material functions as an assist dopant, and high color purity can be exhibited. The TADF material may be any compound as long as its emission spectrum at least partially overlaps with the absorption spectrum of the polycyclic aromatic compound represented by formula (1). The polycyclic aromatic compound represented by formula (1) and the TADF material may both be contained in the same layer or may be contained in adjacent layers.

[0338] Examples of the TADF material that can be used for such an object include a compound represented by the following formula (H7) or a compound having the following formula (H7) as a partial structure.

Chemical formula

[0339] In formula (H7), ED is an electron-donating group, Ln is a linking group, and EA is an electron-accepting group. The energy difference (ΔE S1 ) between the lowest excited singlet energy level (E T1 ) and the lowest excited triplet energy level (E ST ) of the compound represented by formula (H7) is 0.2 eV or less (Hiroki Uoyama, Kenichi Goushi, Katsuyuki Shizu, Hiroko Nomura, Chihaya Adachi, Nature, 492, 234-238 (2012)). The energy difference (ΔE ST ) is preferably 0.15 eV or less, more preferably 0.10 eV or less, and even more preferably 0.08 eV or less.

[0340] As the electron-donating group (donor structure) and the electron-accepting group (acceptor structure) used for the TADF material, for example, the structures described in Chemistry of Materials, 2017, 29, 1946-1963 may be used. As ED, for example, sp 3Examples of the nitrogen-containing functional group include, more specifically, groups derived from carbazole, dimethylcarbazole, di-tert-butylcarbazole, dimethoxycarbazole, tetramethylcarbazole, benzofluorocarbazole, benzothienocarbazole, phenyldihydroindolocarbazole, phenylbicar bazole, bicar bazole, tercarbazole, diphenylcarbazolylamine, tetraphenylcarbazolyl diamine, phenoxazine, dihydrophenazine, phenothiazine, dimethyldihydroacridine, diphenylamine, bis(tert-butylphenyl)amine, N1-(4-(diphenylamino)phenyl)-N4,N4-diphenylbenzene-1,4-diamine, dimethyltetraphenyldihydroacridinediamine, tetramethyl-dihydro-indenacridine, and diphenyl-dihydrodibenzazasiline. Further, examples of the EA include, for example, sp 2A nitrogen-containing aromatic ring, a CN-substituted aromatic ring, a ring having a ketone, and a cyano. More specifically, sulfonyldibenzene, benzophenone, phenylenebis(phenylmethanone), benzonitrile, isonicotinonitrile, phthalonitrile, isophthalonitrile, terephthalonitrile, triazole, oxazole, thiadiazole, benzothiazole, benzobis(thiazole), benzoxazole, benzobis(oxazole), quinoline, benzimidazole, dibenzoquinoxaline, heptaazaphenalene, thioxantone dioxide, dimethylanthraquinone, anthraquinone, pyridine, 5H-cyclopenta[1,2-b.2:5,4-b']dipyridine, benzenetricarbonitrile, fluorenedicarbonitrile, pyrazinedicarbonitrile, pyridinedicarbonitrile, dibenzoquinoxalinecarbonitrile, pyrimidine, phenylpyrimidine, methylpyrimidine, triazine, triphenyltriazine, bis(phenylsulfonyl)benzene, dimethylthioxanthene dioxide, thianthrene tetroxide, and tris(dimethylphenyl)borane and other groups derived therefrom can be mentioned. Examples of Ln include a single bond and an arylene, and more specifically, phenylene, biphenylene, naphthylene and the like can be mentioned. Also, in any structure, hydrogen may be substituted with alkyl, cycloalkyl, and aryl. In particular, as a partial structure, it is preferably a compound having at least one selected from carbazole, phenoxazine, acridine, triazine, pyrimidine, pyrazine, thioxanthene, benzonitrile, phthalonitrile, isophthalonitrile, diphenylsulfone, triazole, oxadiazole, thiadiazole, and benzophenone.

[0341] In formula (H7), the linking group Ln functions as a spacer structure that separates the donor-like partial structure and the acceptor-like partial structure.

[0342] The compound represented by formula (H7) may be, more specifically, a compound represented by any one of formula (H7-1), formula (H7-2), and formula (H7-3).

[0343] [Chem.]

[0344] Among Formula (H7-1), Formula (H7-2), and Formula (H7-3), M is, independently of each other, a single bond, -O-, >N-Ar, or >C(-Ar)2, and from the viewpoints of the depth of the HOMO of the partial structure formed, and the heights of the lowest singlet excitation energy level and the lowest triplet excitation energy level, preferably, it is a single bond, -O-, or >N-Ar. J is a linking group corresponding to Ln in Formula (H7), and is, independently of each other, an arylene having 6 to 18 carbon atoms. From the viewpoint of the magnitude of the conjugation oozing from the donor partial structure and the acceptor partial structure, an arylene having 6 to 12 carbon atoms is preferable, and more specifically, phenylene, methylphenylene, and dimethylphenylene can be mentioned. Q is, independently of each other, =C(-H)- or =N-, and from the viewpoints of the shallowness of the LUMO of the partial structure formed, and the heights of the lowest singlet excitation energy level and the lowest triplet excitation energy level, preferably, it is =N-. Ar is, independently of each other, hydrogen, an aryl having 6 to 24 carbon atoms, a heteroaryl having 2 to 24 carbon atoms, an alkyl having 1 to 12 carbon atoms, or a cycloalkyl having 3 to 18 carbon atoms. From the viewpoints of the depth of the HOMO of the partial structure formed, and the heights of the lowest singlet excitation energy level and the lowest triplet excitation energy level, preferably, it is hydrogen, an aryl having 6 to 12 carbon atoms, a heteroaryl having 2 to 14 carbon atoms, an alkyl having 1 to 4 carbon atoms, or a cycloalkyl having 6 to 10 carbon atoms, more preferably, it is hydrogen, phenyl, tolyl, xylyl, mesityl, biphenyl, pyridyl, bipyridyl, triazolyl, carbazolyl, dimethylcarbazolyl, di-tert-butylcarbazolyl, benzimidazole, or phenylbenzimidazole, and even more preferably, it is hydrogen, phenyl, or carbazolyl. m is 1 or 2. n is an integer from 2 to (6 - m), and from the perspective of steric hindrance, it is preferably an integer from 4 to (6 - m).

[0345] In addition, at least one hydrogen in the compound represented by each of the above formulas may be substituted with a halogen or deuterium.

[0346] Examples of the compound represented by formula (H7) include compounds represented by the following structures. In the structural formula, * represents the bonding position, "Me" represents methyl, and "tBu" represents t-butyl.

[0347]

Chemical formula

[0348]

Chemical formula

[0349]

Chemical formula

[0350]

Chemical formula

[0351]

Chemical formula

[0352]

Chemical formula

[0353]

Chemical formula

[0354]

Chemical formula

[0355]

Chem.

[0356]

Chem.

[0357] As the compound represented by formula (H7), among the above specific compounds, 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 preferable.

[0358] 3-1-5-3. Thermally activated delayed phosphor (assist dopant) The light-emitting layer may contain a thermally activated delayed phosphor as an assist dopant.

[0359] "Thermally activated delayed phosphor" means a compound that can absorb thermal energy, cause reverse intersystem crossing from the lowest excited triplet state to the lowest excited singlet state, and emit radiation deactivation from the lowest excited singlet state to emit delayed fluorescence. However, "thermally activated delayed fluorescence" also includes passing through higher-order triplets in the excitation process from the lowest excited triplet state to the lowest excited singlet state. For example, papers by Monkman et al. of Durham University (NATURE COMMUNICATIONS, 7:13680, DOI:10.1038 / Ncomms 13680), papers by Hosokai et al. of the National Institute of Advanced Industrial Science and Technology (Hosokai et al., Sci.Adv. 2017; 3:e1603282), papers by Sato et al. of Kyoto University (Scientific Reports, 7:4820, DOI:10.1038 / s41598-017-05007-7), as well as conference presentations by Sato et al. of Kyoto University (98th Spring 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), reviews by Bui et al. (DOI:10.3762 / bjoc.14.18), reviews by Duan et al. (DOI:10.1063 / 1.5143501), reviews by Ding et al. (DOI:10.1088 / 1674-4926 / 42 / 5 / 050201), and reviews by Xie et al. (DOI:10.1002 / adom.202002204), etc. In the present invention, for a sample containing a target compound, when the fluorescence lifetime is measured at 300K and a slow fluorescence component is observed, the target compound shall be determined to be a "thermally activated delayed phosphor". Here, the slow fluorescence component refers to those with a fluorescence lifetime of 0.1 μsec or more. The measurement of the fluorescence lifetime can be performed using, for example, a fluorescence lifetime measurement device (manufactured by Hamamatsu Photonics, C11367-01).

[0360] The polycyclic aromatic compound represented by formula (1) can function as an emitting dopant, and the "thermally activated delayed phosphor" can function as an assist dopant that assists the emission of the polycyclic aromatic compound represented by formula (1).

[0361] In the following description, an organic electroluminescent device using a thermally activated delayed phosphor as an assist dopant may be referred to as a "TAF device" (TAF Assisting Fluorescence device).

[0362] The "host compound" in a TAF device means a compound in which the lowest excited singlet energy level obtained from the shoulder on the short wavelength side of the peak of the fluorescence spectrum is higher than that of the thermally activated delayed phosphor as an assist dopant and the emitting dopant.

[0363] In this embodiment, a known compound may be used as the host compound. For example, a compound having at least one of a carbazole ring and a furan ring may be mentioned. Among them, it is preferable to use a compound in which at least one of furanyl and carbazolyl is bonded to at least one of arylene and heteroarylene. Specific examples include mCP and mCBP.

[0364] The lowest excited triplet energy level E(1,T,Sh) obtained from the shoulder on the short wavelength side of the peak of the phosphorescence spectrum of the host compound is preferably higher than the lowest excited triplet energy levels E(2,T,Sh) and E(3,T,Sh) of the emitting dopant or assist dopant having the highest lowest excited triplet energy level in the light emitting layer from the viewpoint of promoting the generation of TADF 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 more higher than E(2,T,Sh) and E(3,T,Sh), more preferably 0.03 eV or more higher, and further preferably 0.1 eV or more higher. Also, a compound having TADF activity may be used as the host compound.

[0365] The thermally activated delayed phosphor (TADF compound) used in the TAF element is preferably a donor-acceptor type thermally activated delayed phosphor (D-A type TADF compound) designed to cause efficient reverse intersystem crossing by localizing the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) in the molecule using an electron-donating substituent called a donor and an electron-accepting substituent called an acceptor.

[0366] Here, in this specification, the "electron-donating substituent" (donor) means a substituent and partial structure in which the HOMO orbital is localized in the thermally activated delayed phosphor molecule, and the "electron-accepting substituent" (acceptor) means a substituent and partial structure in which the LUMO orbital is localized in the thermally activated delayed phosphor molecule.

[0367] Generally, a thermally activated delayed phosphor using a donor or an acceptor has a large spin-orbit coupling (SOC) due to its structure. At the same time, the exchange interaction between HOMO and LUMO is small, and ΔE S1T1 is small, so a very fast reverse intersystem crossing rate can be obtained. On the other hand, a thermally activated delayed phosphor using a donor or an acceptor has a large structural relaxation in the excited state (in some molecules, the stable structures in the ground state and the excited state are different, so when the conversion from the ground state to the excited state occurs due to an external stimulus, the structure then changes to the stable structure in the excited state), and provides a broad emission spectrum, so there is a possibility of reducing the color purity when used as a light-emitting material.

[0368] As the thermally activated delayed phosphor in the TAF element, for example, a compound in which a donor and an acceptor are bonded directly or via a spacer may be used. As the electron-donating group (donor structure) and the 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 may be used. Examples of the donor structure include carbazole, dimethylcarbazole, di-tert-butylcarbazole, dimethoxycarbazole, tetramethylcarbazole, benzofluorocarbazole, benzothienocarbazole, phenyldihydroindolocarbazole, phenylbicarba zole, bicarba zole, tercarbazole, diphenylcarbazolylamine, tetraphenylcarbazolyl diamine, phenoxazine, dihydrophenazine, phenothiazine, dimethyldihydroacridine, diphenylamine, bis(tert-butylphenyl)amine, N1-(4-(diphenylamino)phenyl)-N4,N4-diphenylbenzene-1,4-diamine, dimethyltetraphenyldihydroacridinediamine, tetramethyl-dihydroindenacridine, and diphenyldihydrodibenzazasiline.Acceptor structures include sulfonyldibenzene, benzophenone, phenylenebis(phenylmethanone), benzonitrile, isonicotinonitrile, phthalonitrile, isophthalonitrile, terephthalonitrile, benzenetricarbonitrile, triazole, oxazole, thiadiazole, benzothiazole, benzobis(thiazole), benzoxazole, benzobis(oxazole), quinoline, benzimidazole, dibenzoquinoxaline, heptaazaphenalene, thioxantone dioxide, dimethylanthraquinone, anthraquinone, 5H-cyclopenta[1,2-b:5,4-b']dipyridine, fluorenedicarbonitrile, triphenyltriazine, pyrazinedicarbonitrile, pyrimidine, phenylpyrimidine, methylpyrimidine, pyridinedicarbonitrile, dibenzoquinoxalinedicarbonitrile, bis(phenylsulfonyl)benzene, dimethylthioxanthene dioxide, thianthrene tetroxide, and tris(dimethylphenyl)borane. In particular, a compound having thermally activated delayed fluorescence in a TAF element preferably has at least one selected from carbazole, phenoxazine, acridine, triazine, pyrimidine, pyrazine, thioxanthene, benzonitrile, phthalonitrile, isophthalonitrile, diphenylsulfone, triazole, oxadiazole, thiadiazole, and benzophenone as a partial structure.

[0369] The compound used as an assist dopant in the light-emitting layer of a TAF element is preferably a thermally activated delayed phosphor, and its emission spectrum preferably overlaps at least partially with the absorption peak of the emitting dopant.

[0370] 3-1-5-4. Phosphorescent material (assist dopant) In the light-emitting layer, a phosphorescent material may be used as an assist dopant. The phosphorescent material utilizes the intramolecular spin-orbit interaction (heavy atom effect) by metal atoms to obtain light emission from the triplet state. As such a phosphorescent material, for example, a luminescent metal complex may be used. Examples of the luminescent metal complex include compounds represented by the following formula (B-1) and the following formula (B-2).

[0371] [Chemical formula]

[0372] In formula (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 "X-Y" are each independently a bidentate ligand. In formula (B-2), M is at least one selected from the group consisting of Pt, Re, and Cu, and "W-X-Y-Z" is a tetradentate ligand. In formula (B-1), from the viewpoints of efficiency and lifetime, M is preferably Ir and n is preferably 3. In formula (B-2), from the viewpoints of efficiency and lifetime, M is preferably Pt.

[0373] The ligand (X-Y) in formula (B-1) has at least one ligand selected from the group consisting of the following. The ligand (W-X-Y-Z) in formula (B-2) has at least one ligand selected from the group consisting of the following as a part.

[0374] [Chemical formula]

[0375] In the formula,[[]]END]] --- binds to the central metal M, Y are each independently BR e , NR e , PR e , O, S, Se, C=O, S=O, SO2, CRe R f 、 SiR e R f 、 or GeR e R f and the aromatic carbon C-H in the ring may each independently be substituted with N, R e and R f may optionally be fused or bonded to form a ring, R a 、 R b 、 R c 、 and R d may each independently be unsubstituted or substituted up to the maximum number of substituents possible, R a 、 R b 、 R c 、 R d 、 R e 、 and R f are each independently hydrogen, deuterium, halide, alkyl, cycloalkyl, heteroalkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, aryl, heteroaryl, nitrile, isonitrile, sulfanyl, or a combination thereof, provided that any two adjacent substituents in R a 、 R b 、 R c 、 and R d may be fused or bonded to form a ring or a multidentate ligand.

[0376] Examples of the compound 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), 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.

[0377] Other examples of the compound represented by formula (B-1) include the following compounds.

Chemical formula

[0378]

Chemical formula

[0379]

Chemical formula

[0380] Alternatively, iridium complexes described in JP-A Nos. 2006-089398, 2006-080419, 2005-298483, 2005-097263, and 2004-111379, and US Patent Application Publication No. 2019 / 0051845, 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 also be used.

[0381] 3-1-6. Electron injection layer and electron transport layer in organic electroluminescent device The electron injection layer (107) serves to efficiently inject electrons moving from the negative electrode (108) into the light-emitting layer (105) or the electron transport layer (106). The electron transport layer (106) serves to efficiently transport electrons injected from the negative electrode (108) or electrons injected from the negative electrode (108) through the electron injection layer (107) to the light-emitting layer (105). The electron transport layer (106) and the electron injection layer (107) are each formed by laminating or mixing one or more electron transport / injection materials, or by a mixture of an electron transport / injection material and a polymer binder.

[0382] The electron injection / transport layer is a layer that is responsible for injecting electrons into the negative electrode and transporting electrons. It is preferable that the electron injection efficiency is high and the injected electrons can be transported efficiently. For this purpose, it is preferable that the material has a large electron affinity, a large electron mobility, excellent stability, and is less likely to generate trap impurities during manufacturing and use. However, when considering the transport balance of holes and electrons, if it mainly plays a role in efficiently preventing holes from flowing to the negative electrode side without recombination to the positive electrode, even if the electron transport ability is not so high, the effect of improving the light emission efficiency is equivalent to that of a material with a high electron transport ability. Therefore, the electron injection / transport layer in this embodiment may also include the function of a layer that can efficiently prevent the movement of holes.

[0383] As the material (electron transport material) for forming the electron transport layer (106) or the electron injection layer (107), it may be arbitrarily selected from compounds that have been 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.

[0384] As the material used for the electron transport layer or the electron injection layer, it preferably contains at least one selected from compounds composed of aromatic rings or heteroaromatic rings composed of one or more atoms selected from carbon, hydrogen, oxygen, sulfur, silicon, and phosphorus, pyrrole derivatives and their condensed ring derivatives, and metal complexes having electron-accepting nitrogen. Specifically, examples include condensed ring aromatic ring derivatives such as naphthalene and anthracene, stilbene 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, aryl nitrile derivatives, and indole derivatives. Examples of metal complexes having electron-accepting nitrogen include hydroxyazole complexes such as hydroxyphenyloxazole complexes, azomethine complexes, tropolone metal complexes, flavonol metal complexes, and benzoquinoline metal complexes. These materials can be used alone or in combination with other materials.

[0385] Also, as specific examples of other electron transfer compounds, 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, triazine derivatives, pyrazine derivatives, benzoquinoline derivatives (such as 2,2’-bis(benzo[h]quinolin-2-yl)-9,9’-spirofluorene), imidazopyridine derivatives, borane derivatives, benzimidazole derivatives (such as tris(N-phenylbenzimidazol-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-naphthyridin-2-yl)phenylphosphine oxide), aldazine derivatives, aryl nitrile derivatives, indole derivatives, phosphine oxide derivatives, bisstilbene derivatives, and the like can be mentioned.

[0386] Also, a metal complex having electron-accepting nitrogen may be used, for example, hydroxyazole complexes such as quinolinol-based metal complexes and hydroxyphenyloxazole complexes, azomethine complexes, tropolone metal complexes, flavonol metal complexes, and benzoquinoline metal complexes.

[0387] The above materials can be used alone or in combination with other materials.

[0388] Among the above-mentioned materials, borane derivatives, pyridine derivatives, fluoranthene derivatives, BO-based derivatives, benzofluorene derivatives, phosphine oxide derivatives, pyrimidine derivatives, aryl nitrile derivatives, triazine derivatives, benzimidazole derivatives, phenanthroline derivatives, and quinolinol-based metal complexes are preferred.

[0389] <Borane derivative> The borane derivative is, for example, a compound represented by the following formula (ETM-1), and specifically, it is disclosed in JP-A-2007-27587.

[0390] [Chemical formula]

[0391] In formula (ETM-1), R 11 and R 12 are each independently at least one of hydrogen, alkyl, cycloalkyl, aryl which may be substituted, silyl which may be substituted, a heterocyclic compound having a nitrogen atom which may be substituted, or cyano, and R 13 ~R 16 are each independently alkyl which may be substituted, cycloalkyl which may be substituted, or aryl which may be substituted, X is arylene which may be substituted, Y is aryl having 16 or less carbon atoms which may be substituted, boryl which may be substituted, or carbazolyl which may be substituted, and n is each independently an integer of 0 to 3. Further, examples of the substituent in the case of "may be substituted" or "substituted" include aryl, heteroaryl, alkyl, or cycloalkyl.

[0392] Among the compounds represented by formula (ETM-1), the compounds represented by the following formula (ETM-1-1) and the compounds represented by the following formula (ETM-1-2) are preferred. [Chemical formula]

[0393] In formula (ETM-1-1), R 11 and R 12 are each independently at least one of hydrogen, alkyl, cycloalkyl, aryl which may be substituted, silyl which may be substituted, a heterocyclic compound having a nitrogen atom which may be substituted, or cyano, and R 13 ~R 16 are each independently alkyl which may be substituted, cycloalkyl which may be substituted, or aryl which may be substituted, and R 21 and R 22 are each independently at least one of hydrogen, alkyl, cycloalkyl, aryl which may be substituted, silyl which may be substituted, a heterocyclic compound having a nitrogen atom which may be substituted, or cyano, X 1 is an arylene having 20 or less carbon atoms which may be substituted, n is an integer of 0 to 3 independently of each other, and m is an integer of 0 to 4 independently of each other. Further, examples of the substituent in the case of "which may be substituted" or "substituted" include aryl, heteroaryl, alkyl, or cycloalkyl.

[0394]

Chemical formula

[0395] In formula (ETM-1-2), R 11 and R 12 are each independently at least one of hydrogen, alkyl, cycloalkyl, aryl which may be substituted, silyl which may be substituted, a heterocyclic compound having a nitrogen atom which may be substituted, or cyano, and R 13 ~R 16 are each independently alkyl which may be substituted, cycloalkyl which may be substituted, or aryl which may be substituted, and X 1is an arylene having 20 or fewer carbon atoms which may be substituted, and n is an integer of 0 to 3, each independently. Further, examples of the substituent in the case of "may be substituted" or "substituted" include aryl, heteroaryl, alkyl, or cycloalkyl.

[0396] X 1 Specific examples of [X] include a divalent group represented by any one of the following formulas (X-1) to (X-9).

Chemical formula

[0397] (In each formula, R a is independently alkyl, cycloalkyl, or phenyl which may be substituted, and * indicates the bonding position.)

[0398] Specific examples of this borane derivative include, for example, the following compounds.

Chemical formula

[0399] This borane derivative can be produced using known raw materials and known synthesis methods.

[0400] <Pyridine derivative> The pyridine derivative is, for example, a compound represented by the following formula (ETM-2), preferably a compound represented by formula (ETM-2-1) or formula (ETM-2-2).

Chemical formula

[0401] 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 of 1 to 4.

[0402] In formula (ETM-2-1), R 11 ~R 18 is each 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).

[0403] In formula (ETM-2-2), R 11 and R 12 are each 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), and R 11 and R 12 may combine to form a ring.

[0404] In each formula, the "pyridine-based substituent" is any one of the following formulas (Py-1) to (Py-15) (the * in the formula indicates the bonding position), and the pyridine-based substituent may each independently be substituted with alkyl having 1 to 4 carbon atoms or cycloalkyl having 5 to 10 carbon atoms. Specific examples include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, s-butyl, or t-butyl, etc., and methyl is preferred. Further, the pyridine-based substituent may be bonded to φ, anthracene ring, or fluorene ring in each formula via phenylene or naphthylene.

[0405]

Chemical formula

[0406] The pyridine-based substituent is any one of the formulas (Py-1) to (Py-15) (the * in the formula indicates the bonding position), but among these, it is preferably any one of the following formulas (Py-21) to (Py-44).

[0407]

Chemical formula

[0408] At least one hydrogen in each pyridine derivative may be substituted with deuterium, and one of the two "pyridine-based substituents" in Formula (ETM-2-1) and Formula (ETM-2-2) may be substituted with aryl.

[0409] R 11 ~R 18 The "alkyl" in ~ may be either straight-chain or branched-chain, and examples thereof include straight-chain alkyl having 1 to 24 carbon atoms or branched-chain alkyl having 3 to 24 carbon atoms. Preferred "alkyl" is alkyl having 1 to 18 carbon atoms (branched-chain alkyl having 3 to 18 carbon atoms). More preferred "alkyl" is alkyl having 1 to 12 carbon atoms (branched-chain alkyl having 3 to 12 carbon atoms). Even more preferred "alkyl" is alkyl having 1 to 6 carbon atoms (branched-chain alkyl having 3 to 6 carbon atoms). Particularly preferred "alkyl" is alkyl having 1 to 4 carbon atoms (branched-chain alkyl having 3 to 4 carbon atoms).

[0410] Specific examples of "alkyl" include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, s-butyl, t-butyl, n-pentyl, isopentyl, neopentyl, t-pentyl, n-hexyl, 1-methylpentyl, 4-methyl-2-pentyl, 3,3-dimethylbutyl, 2-ethylbutyl, n-heptyl, 1-methylhexyl, n-octyl, t-octyl, 1-methylheptyl, 2-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, n-eicosyl, and the like.

[0411] Examples of the C1-C4 alkyl substituted with a pyridine-based substituent include those cited in the description of the alkyl above.

[0412] R 11 ~R 18 Examples of the "cycloalkyl" in R~R include cycloalkyls having 3 to 12 carbon atoms. Preferred "cycloalkyl" is cycloalkyl having 3 to 10 carbon atoms. More preferred "cycloalkyl" is cycloalkyl having 3 to 8 carbon atoms. Even more preferred "cycloalkyl" is cycloalkyl having 3 to 6 carbon atoms.

[0413] Specific examples of the "cycloalkyl" include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, methylcyclopentyl, cycloheptyl, methylcyclohexyl, cyclooctyl, or dimethylcyclohexyl.

[0414] R 11 ~R 18 Examples of the "aryl" in R~R include preferred aryls having 6 to 30 carbon atoms, more preferred aryls having 6 to 18 carbon atoms, even more preferred aryls having 6 to 14 carbon atoms, and particularly preferred aryls having 6 to 12 carbon atoms.

[0415] Specific examples of the "aryl having 6 to 30 carbon atoms" include phenyl as a monocyclic aryl, (1-, 2-) naphthyl as a condensed bicyclic aryl, acenaphthylen-(1-, 3-, 4-, 5-) yl as a condensed tricyclic aryl, fluorene-(1-, 2-, 3-, 4-, 9-) yl, phenalen-(1-, 2-) yl, (1-,2-,3-,4-,9-) phenanthryl, triphenylene-(1-,2-) yl as a condensed tetracyclic aryl, pyrene-(1-,2-,4-) yl, naphthacene-(1-,2-,5-) yl, perylene-(1-,2-,3-) yl as a condensed pentacyclic aryl, pentacene-(1-,2-,5-,6-) yl, etc.

[0416] Preferred "aryl having 6 to 30 carbon atoms" includes phenyl, naphthyl, phenanthryl, chrysenyl, or triphenylenyl, etc., more preferably phenyl, 1-naphthyl, 2-naphthyl, or phenanthryl, and particularly preferably phenyl, 1-naphthyl, or 2-naphthyl.

[0417] R in formula (ETM-2-2) 11 and R 12 may combine to form a ring. As a result, a cyclobutane, cyclopentane, cyclopentene, cyclopentadiene, cyclohexane, fluorene, or indene, etc. may be spiro-bonded to the 5-membered ring of the fluorene skeleton.

[0418] Specific examples of this pyridine derivative include, for example, the following compounds.

Chemical formula

[0419] This pyridine derivative can be produced using known raw materials and known synthesis methods.

[0420] <Fluoranthene derivative> The fluoranthene derivative is a compound represented by, for example, the following formula (ETM-3), and specifically, it is disclosed in International Publication No. 2010 / 134352.

[0421]

Chemical formula

[0422] Among formula (ETM-3), X12 to X21 represent hydrogen, halogen, linear, branched, or cyclic alkyl, linear, branched, or cyclic alkoxy, substituted or unsubstituted aryl, or substituted or unsubstituted heteroaryl. Here, examples of the substituent when it is substituted include aryl, heteroaryl, alkyl, or cycloalkyl, etc.

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

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).

[0425]

Chemical formula

[0426] R 1 ~R 11 Each independently represents hydrogen, 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] Also, among R 1 ~R 11 adjacent groups may be bonded to each other to form an aryl ring or a heteroaryl ring together with the a-ring, b-ring, 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.

[0428] Also, at least one hydrogen in the compound or structure represented by the formula (ETM-4) may be substituted with halogen or deuterium.

[0429] Regarding the description of the substituents and the form of ring formation in formula (ETM-4), the description of the polycyclic aromatic compound having the structure represented by formula (1) can be cited.

[0430] Specific examples of this BO-based derivative include, for example, the following compounds.

Chemical formula

[0431] This BO-based derivative can be produced using known raw materials and known synthesis methods.

[0432] <Benzofluorene derivative> The benzofluorene derivative is, for example, a compound represented by the following formula (ETM-6).

Chemical formula

[0433] Ar 1 is each independently an aryl having 6 to 20 carbon atoms, and the description such as "aryl having 6 to 20 carbon atoms" in Ar of formula (ETM-5) 2 can be cited. An aryl having 6 to 16 carbon atoms is preferable, an aryl having 6 to 12 carbon atoms is more preferable, and an aryl having 6 to 10 carbon atoms is particularly preferable. Specific examples include phenyl, biphenylyl, naphthyl, terphenylyl, anthracenyl, acenaphthylenyl, fluorenyl, phenalenyl, phenanthryl, triphenylenyl, pyrenyl, tetracenyl, perylenyl, and the like.

[0434] Ar 2 is each 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), and two Ars 2 may be bonded to form a ring.

[0435] Ar 2 In the formula, the "alkyl" may be either linear or branched, and examples thereof include linear alkyl having 1 to 24 carbon atoms or branched alkyl having 3 to 24 carbon atoms. Preferred "alkyl" is alkyl having 1 to 18 carbon atoms (branched alkyl having 3 to 18 carbon atoms). More preferred "alkyl" is alkyl having 1 to 12 carbon atoms (branched alkyl having 3 to 12 carbon atoms). Even more preferred "alkyl" is alkyl having 1 to 6 carbon atoms (branched alkyl having 3 to 6 carbon atoms). Particularly preferred "alkyl" is alkyl having 1 to 4 carbon atoms (branched alkyl having 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, 1-methylhexyl, and the like.

[0436] Ar 2 In the formula, the "cycloalkyl" includes, for example, cycloalkyl having 3 to 12 carbon atoms. Preferred "cycloalkyl" is cycloalkyl having 3 to 10 carbon atoms. More preferred "cycloalkyl" is cycloalkyl having 3 to 8 carbon atoms. Even more preferred "cycloalkyl" is cycloalkyl having 3 to 6 carbon atoms. Specific examples of "cycloalkyl" include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, methylcyclopentyl, cycloheptyl, methylcyclohexyl, cyclooctyl, or dimethylcyclohexyl, and the like.

[0437] Ar 2 In the formula, the "aryl" is preferably aryl having 6 to 30 carbon atoms, more preferably aryl having 6 to 18 carbon atoms, even more preferably aryl having 6 to 14 carbon atoms, and particularly preferably aryl having 6 to 12 carbon atoms.

[0438] Specific examples of the "aryl having 6 to 30 carbon atoms" include phenyl, naphthyl, acenaphthylenyl, fluorenyl, phenalenyl, phenanthryl, triphenylenyl, pyrenyl, naphthacenyl, perylenyl, pentacenyl and the like.

[0439] Two Ars 2 may be bonded to form a ring. As a result, cyclobutane, cyclopentane, cyclopentene, cyclopentadiene, cyclohexane, fluorene, or indene may be spiro-bonded to the 5-membered ring of the fluorene skeleton.

[0440] Specific examples of this benzofluorene derivative include, for example, the following compounds.

Chemical formula

[0441] This benzofluorene derivative can be produced using known raw materials and known synthesis methods.

[0442] <Phosphine oxide derivative> The phosphine oxide derivative is, for example, a compound represented by the following formula (ETM-7-1). Details are also described in International Publication No. 2013 / 079217 and International Publication No. 2013 / 079678.

Chemical formula

[0443] R 5 is a substituted or unsubstituted alkyl having 1 to 20 carbon atoms, cycloalkyl having 3 to 16 carbon atoms, aryl having 6 to 20 carbon atoms or heteroaryl having 5 to 20 carbon atoms, R 6is CN, a substituted or unsubstituted alkyl having 1 to 20 carbon atoms, a cycloalkyl having 3 to 16 carbon atoms, a heteroalkyl having 1 to 20 carbon atoms, an aryl having 6 to 20 carbon atoms, a heteroaryl having 5 to 20 carbon atoms, an alkoxy having 1 to 20 carbon atoms, or an aryloxy having 6 to 20 carbon atoms, R 7 and R 8 are each independently a substituted or unsubstituted aryl having 6 to 20 carbon atoms or a heteroaryl having 5 to 20 carbon atoms, R 9 is oxygen or sulfur, j is 0 or 1, k is 0 or 1, r is an integer from 0 to 4, and q is an integer from 1 to 3.

[0444] Here, when substituted, examples of the substituent include aryl, heteroaryl, alkyl, or cycloalkyl.

[0445] The phosphine oxide derivative may be, for example, a compound represented by the following formula (ETM-7-2).

Chemical formula

[0446] R 1 ~R 3 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 a condensed ring formed between adjacent substituents.

[0447] Ar 1 may be the same or different and is arylene or heteroarylene. Ar 2may be the same or different and is aryl or heteroaryl. However, Ar 1 and Ar 2 at least one of which has a substituent or forms a condensed ring with an adjacent substituent. n is an integer from 0 to 3. When n is 0, there is no unsaturated structure part. When n is 3, R 1 does not exist.

[0448] Among these substituents, alkyl represents a saturated aliphatic hydrocarbon group such as methyl, ethyl, propyl, butyl, etc., which may be unsubstituted or substituted. There is no particular limitation on the substituent when it is substituted. For example, alkyl, aryl, heterocyclic group, etc. may be mentioned. This point is also common in the following descriptions. Also, the number of carbon atoms of alkyl is not particularly limited, but usually ranges from 1 to 20 from the viewpoints of availability and cost.

[0449] Also, cycloalkyl represents a saturated alicyclic hydrocarbon group such as cyclopropyl, cyclohexyl, norbornyl, adamantyl, etc., which may be unsubstituted or substituted. The number of carbon atoms in the alkyl part is not particularly limited, but usually ranges from 3 to 20.

[0450] Also, aralkyl represents an aromatic hydrocarbon group via an aliphatic hydrocarbon such as benzyl, phenylethyl, etc. Both the aliphatic hydrocarbon and the aromatic hydrocarbon may be unsubstituted or substituted. The number of carbon atoms in the aliphatic part is not particularly limited, but usually ranges from 1 to 20.

[0451] Also, alkenyl represents an unsaturated aliphatic hydrocarbon group containing a double bond such as vinyl, aryl, butadienyl, etc., which may be unsubstituted or substituted. The number of carbon atoms of alkenyl is not particularly limited, but usually ranges from 2 to 20.

[0452] Also, cycloalkenyl represents an unsaturated alicyclic hydrocarbon group containing a double bond such as cyclopentenyl, cyclopentadienyl, cyclohexenyl, etc., which may be unsubstituted or substituted.

[0453] Also, alkynyl represents an unsaturated aliphatic hydrocarbon group containing a triple bond such as ethynyl, etc., which may be unsubstituted or substituted. The number of carbon atoms in alkynyl is not particularly limited, but is usually in the range of 2 to 20.

[0454] Also, alkoxy represents an aliphatic hydrocarbon group formed by an ether bond such as methoxy, etc., and the aliphatic hydrocarbon group may be unsubstituted or substituted. The number of carbon atoms in alkoxy is not particularly limited, but is usually in the range of 1 to 20.

[0455] Also, alkylthio is a group in which the oxygen atom of the ether bond of alkoxy is substituted by a sulfur atom.

[0456] Also, cycloalkylthio is a group in which the oxygen atom of the ether bond of cycloalkoxy is substituted by a sulfur atom.

[0457] Also, aryl ether represents an aromatic hydrocarbon group formed by an ether bond such as phenoxy, etc., and the aromatic hydrocarbon group may be unsubstituted or substituted. The number of carbon atoms in aryl ether is not particularly limited, but is usually in the range of 6 to 40.

[0458] Also, arylthioether is a group in which the oxygen atom of the ether bond of aryl ether is substituted by a sulfur atom.

[0459] Also, aryl represents an aromatic hydrocarbon group such as phenyl, naphthyl, biphenylyl, phenanthryl, terphenylyl, pyrenyl, etc. Aryl may be unsubstituted or substituted. The number of carbon atoms in aryl is not particularly limited, but is usually in the range of 6 to 40.

[0460] The heterocyclic group represents, for example, a cyclic structural group having an atom other than carbon, such as furanyl, thienyl, oxazolyl, pyridyl, quinolinyl, carbazolyl, etc., and this may be unsubstituted or substituted. The number of carbon atoms in the heterocyclic group is not particularly limited, but is usually in the range of 2 to 30.

[0461] Halogen refers to fluorine, chlorine, bromine, and iodine.

[0462] The aldehyde, carbonyl, and amino groups can also include groups substituted with aliphatic hydrocarbons, alicyclic hydrocarbons, aromatic hydrocarbons, heterocycles, etc.

[0463] In addition, the aliphatic hydrocarbon, alicyclic hydrocarbon, aromatic hydrocarbon, and heterocycle may be unsubstituted or substituted.

[0464] Silyl represents, for example, a silicon compound group such as trimethylsilyl, and this may be unsubstituted or substituted. The number of carbon atoms in silyl is not particularly limited, but is usually in the range of 3 to 20. Also, the number of silicon atoms is usually 1 to 6.

[0465] The condensed 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 etc. are conjugated or non-conjugated condensed rings formed between. Here, when n is 1, two R 1 may form a conjugated or non-conjugated condensed ring with each other. These condensed rings may contain nitrogen, oxygen, or sulfur atoms in the ring structure and may be further condensed with other rings.

[0466] Specific examples of this phosphine oxide derivative include, for example, the following compounds. [Chemistry]

[0467] This phosphine oxide derivative can be produced using known raw materials and known synthesis methods.

[0468] <Pyrimidine derivative> The pyrimidine derivative is, for example, a compound represented by the following formula (ETM-8), preferably a compound represented by the following formula (ETM-8-1). Details are also described in International Publication No. 2011 / 021689. [Chemistry]

[0469] Ar is each independently optionally substituted aryl or optionally substituted heteroaryl. n is an integer of 1 to 4, preferably an integer of 1 to 3, more preferably 2 or 3.

[0470] Examples of the "aryl" in the "optionally substituted aryl" include aryl having 6 to 30 carbon atoms, preferably aryl having 6 to 24 carbon atoms, more preferably aryl having 6 to 20 carbon atoms, and still more preferably aryl having 6 to 12 carbon atoms.

[0471] Specific "aryl" includes, for example, phenyl of monocyclic aryl, (2-, 3-, 4-) biphenylyl of bicyclic aryl, (1-, 2-) naphthyl of condensed bicyclic aryl, terphenylyl of tricyclic aryl (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), (1-, 3-, 4-, 5-) acenaphthylenyl of condensed tricyclic aryl, (1-, 2-, 3-, 4-, 9-) fluorenyl of condensed tricyclic aryl, (1-, 2-) phenalenyl of condensed tricyclic aryl, (1-, 2-, 3-, 4-, 9-) phenanthryl of condensed tricyclic aryl, (5'-phenyl-m-terphenyl-2-yl, 5'-phenyl-m-terphenyl-3-yl, 5'-phenyl-m-terphenyl-4-yl, m-quarterphenyl) of quarterphenyl of tetracyclic aryl, (1-, 2-) triphenylenyl of condensed tetracyclic aryl, (1-, 2-, 4-) pyrenyl of condensed tetracyclic aryl, (1-, 2-, 5-) naphthacenyl of condensed tetracyclic aryl, (1-, 2-, 3-) perylenyl of condensed pentacyclic aryl, (1-, 2-, 5-, 6-) pentacenyl of condensed pentacyclic aryl, etc.

[0472] Examples of the "heteroaryl" in "optionally substituted heteroaryl" include heteroaryl having 2 to 30 carbon atoms, preferably heteroaryl having 2 to 25 carbon atoms, more preferably heteroaryl having 2 to 20 carbon atoms, still more preferably heteroaryl having 2 to 15 carbon atoms, and particularly preferably heteroaryl having 2 to 10 carbon atoms. Further, examples of the heteroaryl include heterocycles containing 1 to 5 heteroatoms selected from oxygen, sulfur, and nitrogen in addition to carbon as ring-constituting atoms.

[0473] Specific heteroaryls include, for example, furyl, thienyl, pyrrolyl, oxazolyl, isoxazolyl, thiazolyl, isothiazolyl, imidazolyl, pyrazolyl, oxadiazolyl, furazanyl, thiadiazolyl, triazolyl, tetrazolyl, pyridyl, pyrimidinyl, pyridazinyl, pyrazinyl, triazinyl, benzofuranyl, isobenzofuranyl, benzo[b]thienyl, indolyl, isoindolyl, 1H-indazolyl, benzimidazolyl, benzoxazolyl, benzothiazolyl, 1H-benzotriazolyl, quinolyl, isoquinolyl, cinnolyl, quinazolinyl, quinoxalinyl, phthalazinyl, naphthyridinyl, purinyl, pteridinyl, carbazolyl, acridinyl, phenoxazinyl, phenothiazinyl, phenazinyl, phenoxathiinyl, thianthrenyl, indolizinyl, and the like.

[0474] Also, the aryl and heteroaryl may be substituted, and may be substituted with, for example, the aryl or heteroaryl respectively.

[0475] Specific examples of this pyrimidine derivative include, for example, the following compounds.

Chemical formula

[0476] This pyrimidine derivative can be produced using known raw materials and known synthesis methods.

[0477] <Aryl nitrile derivative> The aryl nitrile derivative is, for example, a compound represented by the following formula (ETM-9), or a multimer in which a plurality of them are bonded by a single bond or the like. Details are described in US Patent Application Publication No. 2014 / 0197386.

[0478]

Chemical formula

[0479] Ar NiFrom the perspective of high-speed electron transport properties, it is preferable to have a large number of carbon atoms, and from the perspective of high T1, it is preferable to have a small number of carbon atoms. Ar Ni Specifically, for use in the layer adjacent to the light-emitting layer, it is preferably a high T1, and is an aryl having 6 to 20 carbon atoms, preferably an aryl having 6 to 14 carbon atoms, more preferably an aryl having 6 to 10 carbon atoms. Also, the substitution number n of the nitrile group is preferably large from the perspective of high T1, and preferably small from the perspective of high S1. Specifically, the substitution number n of the nitrile group is an integer of 1 to 4, preferably an integer of 1 to 3, more preferably an integer of 1 to 2, and even more preferably 1.

[0480] Each Ar is independently an optionally substituted aryl or an optionally substituted heteroaryl. From the perspectives of high S1 and high T1, it is preferably a donor heteroaryl. Since it is used as an electron transport layer, it is preferably a donor heteroaryl with a small number. From the perspective of charge transport properties, an aryl or heteroaryl with a large number of carbon atoms is preferred, and it is preferred to have many substituents. Specifically, the substitution number m of Ar is an integer of 1 to 4, preferably an integer of 1 to 3, more preferably 1 to 2.

[0481] Examples of the "aryl" in the "optionally substituted aryl" 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.

[0482] Specific "aryl" includes, for example, phenyl of monocyclic aryl, (2-, 3-, 4-) biphenylyl of bicyclic aryl, (1-, 2-) naphthyl of condensed bicyclic aryl, terphenylyl of tricyclic aryl (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), acenaphthylen-(1-, 3-, 4-, 5-)yl, fluorene-(1-, 2-, 3-, 4-, 9-)yl, phenalen-(1-, 2-)yl, (1-, 2-, 3-, 4-, 9-)phenanthryl of condensed tricyclic aryl, quarterphenylyl of tetracyclic aryl (5'-phenyl-m-terphenyl-2-yl, 5'-phenyl-m-terphenyl-3-yl, 5'-phenyl-m-terphenyl-4-yl, m-quarterphenylyl), triphenylene-(1-, 2-)yl, pyrene-(1-, 2-, 4-)yl, naphthacene-(1-, 2-, 5-)yl of condensed tetracyclic aryl, perylene-(1-, 2-, 3-)yl, pentacene-(1-, 2-, 5-, 6-)yl of condensed pentacyclic aryl, and the like.

[0483] Examples of the "heteroaryl" in "optionally substituted heteroaryl" include heteroaryl having 2 to 30 carbon atoms, preferably heteroaryl having 2 to 25 carbon atoms, more preferably heteroaryl having 2 to 20 carbon atoms, still more preferably heteroaryl having 2 to 15 carbon atoms, and particularly preferably heteroaryl having 2 to 10 carbon atoms. Further examples of the heteroaryl include heterocycles containing 1 to 5 heteroatoms selected from oxygen, sulfur, and nitrogen in addition to carbon as ring-constituting atoms.

[0484] Specific heteroaryls include, for example, furyl, thienyl, pyrrolyl, oxazolyl, isoxazolyl, thiazolyl, isothiazolyl, imidazolyl, pyrazolyl, oxadiazolyl, furazanyl, thiadiazolyl, triazolyl, tetrazolyl, pyridyl, pyrimidinyl, pyridazinyl, pyrazinyl, triazinyl, benzofuranyl, isobenzofuranyl, benzo[b]thienyl, indolyl, isoindolyl, 1H-indazolyl, benzimidazolyl, benzoxazolyl, benzothiazolyl, 1H-benzotriazolyl, quinolyl, isoquinolyl, cinnolyl, quinazolinyl, quinoxalinyl, phthalazinyl, naphthyridinyl, purinyl, pteridinyl, carbazolyl, acridinyl, phenoxazinyl, phenothiazinyl, phenazinyl, phenoxathiinyl, thianthrenyl, indolizinyl, and the like.

[0485] Further, the aryl and heteroaryl may be substituted, and may be substituted with, for example, the aryl or heteroaryl respectively.

[0486] The aryl nitrile derivative may be a multimer in which the compound represented by the formula (ETM-9) is bonded by a plurality of single bonds or the like. In this case, in addition to the single bond, it may be bonded by an aryl ring (preferably a polyvalent benzene ring, naphthalene ring, anthracene ring, fluorene ring, benzofluorene ring, phenalene ring, phenanthrene ring, or triphenylene ring).

[0487] Specific examples of this aryl nitrile derivative include, for example, the following compounds.

Chemical formula

[0488] This aryl nitrile derivative can be produced using known raw materials and known synthetic methods.

[0489] <Triazine derivative> The triazine derivative is, for example, a compound represented by the following formula (ETM-10), preferably a compound represented by the following formula (ETM-10-1). Details are described in US Patent Application Publication No. 2011 / 0156013.

[0490]

Chemical formula

[0491] Each Ar is independently optionally substituted aryl or optionally substituted heteroaryl. n is an integer from 1 to 3, preferably 2 or 3.

[0492] Examples of the "aryl" in the "optionally substituted aryl" include aryl having 6 to 30 carbon atoms, preferably aryl having 6 to 24 carbon atoms, more preferably aryl having 6 to 20 carbon atoms, and still more preferably aryl having 6 to 12 carbon atoms.

[0493] Specific "aryl" includes, for example, phenyl of monocyclic aryl, (2-, 3-, 4-) biphenylyl of bicyclic aryl, (1-, 2-) naphthyl of condensed bicyclic aryl, terphenylyl of tricyclic aryl (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), acenaphthylen-(1-,3-,4-,5-)yl of condensed tricyclic aryl, fluorene-(1-,2-,3-,4-, 9-)yl, phenalen-(1-,2-)yl, (1-,2-,3-,4-, 9-)phenanthryl, quarterphenyl of tetracyclic aryl (5'-phenyl-m-terphenyl-2-yl, 5'-phenyl-m-terphenyl-3-yl, 5'-phenyl-m-terphenyl-4-yl, m-quarterphenyl), triphenylene-(1-,2-)yl of condensed tetracyclic aryl, pyrene-(1-,2-,4-)yl, naphthacene-(1-,2-,5-)yl, perylene-(1-,2-,3-)yl of condensed pentacyclic aryl, pentacene-(1-,2-,5-,6-)yl, etc.

[0494] Examples of the "heteroaryl" in "optionally substituted heteroaryl" include, for example, heteroaryl having 2 to 30 carbon atoms, preferably heteroaryl having 2 to 25 carbon atoms, more preferably heteroaryl having 2 to 20 carbon atoms, still more preferably heteroaryl having 2 to 15 carbon atoms, and particularly preferably heteroaryl having 2 to 10 carbon atoms. Further, examples of the heteroaryl include heterocycles containing 1 to 5 heteroatoms selected from oxygen, sulfur, and nitrogen in addition to carbon as ring-constituting atoms.

[0495] Specific heteroaryl groups include, for example, furyl, thienyl, pyrrolyl, oxazolyl, isoxazolyl, thiazolyl, isothiazolyl, imidazolyl, pyrazolyl, oxadiazolyl, furazanyl, thiadiazolyl, triazolyl, tetrazolyl, pyridyl, pyrimidinyl, pyridazinyl, pyrazinyl, triazinyl, benzofuranyl, isobenzofuranyl, benzo[b]thienyl, indolyl, isoindolyl, 1H-indazolyl, benzimidazolyl, benzoxazolyl, benzothiazolyl, 1H-benzotriazolyl, quinolyl, isoquinolyl, cinnolyl, quinazolinyl, quinoxalinyl, phthalazinyl, naphthyridinyl, purinyl, pteridinyl, carbazolyl, acridinyl, phenoxazinyl, phenothiazinyl, phenazinyl, phenoxathiinyl, thianthrenyl, indolizinyl, and the like.

[0496] Also, the aryl and heteroaryl groups may be substituted, for example, each may be substituted with the aryl or heteroaryl group.

[0497] Specific examples of this triazine derivative include, for example, the following compounds.

Chemical formula

[0498] This triazine derivative can be produced using known raw materials and known synthesis methods.

[0499] <Benzimidazole derivative> The benzimidazole derivative is, for example, a compound represented by the following formula (ETM-11).

Chemical formula

[0500] 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-based substituent" is such that the pyridyl in the "pyridine-based substituent" in Formula (ETM-2), Formula (ETM-2-1), and Formula (ETM-2-2) is replaced by the following benzimidazolyl (where * indicates the bonding position), and at least one hydrogen in the benzimidazole derivative may be replaced by deuterium.

[0501]

Chemical formula

[0502] R in the said benzimidazolyl 11 is hydrogen, alkyl having 1 to 24 carbon atoms, cycloalkyl having 3 to 12 carbon atoms, or aryl having 6 to 30 carbon atoms, and the description of R 11 in Formula (ETM-2-1) and Formula (ETM-2-2) can be cited.

[0503] φ is preferably further an anthracene ring or a fluorene ring, and in this case, the structure can cite the description in Formula (ETM-2-1) or Formula (ETM-2-2), and R 11 ~R 18 in each formula can cite the description in Formula (ETM-2-1) or Formula (ETM-2-2). Also, in Formula (ETM-2-1) or Formula (ETM-2-2), although two pyridine-based substituents are described in a bonded form, when replacing these with benzimidazole-based substituents, both pyridine-based substituents may be replaced by benzimidazole-based substituents (i.e., n = 2), or either one of the pyridine-based substituents may be replaced by a benzimidazole-based substituent and the other pyridine-based substituent may be replaced by R 11 ~R 18 (i.e., n = 1). Also, for example, R 11 ~R 18At least one of them is substituted with a benzimidazole-based substituent, and the "pyridine-based substituent" is replaced with R 11 ~R 18 It may be substituted.

[0504] Specific examples of this benzimidazole derivative include, for example, 1-phenyl-2-(4-(10-phenylanthracen-9-yl)phenyl)-1H-benzo[d]imidazole, 2-(4-(10-(naphthalen-2-yl)anthracen-9-yl)phenyl)-1-phenyl-1H-benzo[d]imidazole, 2-(3-(10-(naphthalen-2-yl)anthracen-9-yl)phenyl)-1-phenyl-1H-benzo[d]imidazole, 5-(10-(naphthalen-2-yl)anthracen-9-yl)-1,2-diphenyl-1H-benzo[d]imidazole, 1-(4-(10-(naphthalen-2-yl)anthracen-9-yl)phenyl)-2-phenyl-1H-benzo[d]imidazole, 2-(4-(9,10-di(naphthalen-2-yl)anthracen-2-yl)phenyl)-1-phenyl-1H-benzo[d]imidazole, 1-(4-(9,10-di(naphthalen-2-yl)anthracen-2-yl)phenyl)-2-phenyl-1H-benzo[d]imidazole, 5-(9,10-di(naphthalen-2-yl)anthracen-2-yl)-1,2-diphenyl-1H-benzo[d]imidazole, and the like.

[0505]

Chemical formula

[0506] This benzimidazole derivative can be produced using known raw materials and known synthesis methods.

[0507] <Phenanthroline derivative> The phenanthroline derivative is a compound represented by, for example, the following formula (ETM-12) or formula (ETM-12-1). Details are described in International Publication No. 2006 / 021982.

[0508] [Chemical formula]

[0509] 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.

[0510] In each formula, R 11 ~R 18 are each 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). In formula (ETM-12-1), one of R 11 ~R 18 forms a bond with φ which is an aryl ring.

[0511] At least one hydrogen in each phenanthroline derivative may be substituted with deuterium.

[0512] R 11 ~R 18 For the alkyl, cycloalkyl, and aryl in R 11 ~R 18 in formula (ETM-2), the description can be cited. In addition to the above examples, φ may include, for example, the following structural formulas. In the following structural formulas, each R is independently hydrogen, methyl, ethyl, isopropyl, cyclohexyl, phenyl, 1-naphthyl, 2-naphthyl, biphenylyl, or terphenylyl, and * indicates the bonding position.

[0513] [Chemical formula]

[0514] Specific examples of this phenanthroline derivative include, for example, 4,7-diphenyl-1,10-phenanthroline, 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline, 9,10-di(1,10-phenanthrolin-2-yl)anthracene, 2,6-di(1,10-phenanthrolin-5-yl)pyridine, 1,3,5-tri(1,10-phenanthrolin-5-yl)benzene, 9,9'-difluoro-bis(1,10-phenanthrolin-5-yl)pyridine, bathocuproin, 1,3-bis(2-phenyl-1,10-phenanthrolin-9-yl)benzene, and compounds represented by the following structural formula, etc.

[0515]

Chem.

[0516] This phenanthroline derivative can be produced using known raw materials and known synthesis methods.

[0517] <Quinolinol-based metal complex> The quinolinol-based metal complex is, for example, a compound represented by the following formula (ETM-13).

Chem.

[0518] In the formula, R 1 ~R 6 are each 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.

[0519] Specific examples of the quinolinol-based metal complex include lithium 8-quinolinolate, tris(8-quinolinolato)aluminum, tris(4-methyl-8-quinolinolato)aluminum, tris(5-methyl-8-quinolinolato)aluminum, tris(3,4-dimethyl-8-quinolinolato)aluminum, tris(4,5-dimethyl-8-quinolinolato)aluminum, tris(4,6-dimethyl-8-quinolinolato)aluminum, bis(2-methyl-8-quinolinolato)(phenolato)aluminum, bis(2-methyl-8-quinolinolato)(2-methylphenolato)aluminum, bis(2-methyl-8-quinolinolato)(3-methylphenolato)aluminum, bis(2-methyl-8-quinolinolato)(4-methylphenolato)aluminum, bis(2-methyl-8-quinolinolato)(2-phenylphenolato)aluminum, bis(2-methyl-8-quinolinolato)(3-phenylphenolato)aluminum, bis(2-methyl-8-quinolinolato)(4-phenylphenolato)aluminum, bis(2-methyl-8-quinolinolato)(2,3-dimethylphenolato)aluminum, bis(2-methyl-8-quinolinolato)(2,6-dimethylphenolato)aluminum, bis(2-methyl-8-quinolinolato)(3,4-dimethylphenolato)aluminum, bis(2-methyl-8-quinolinolato)(3,5-dimethylphenolato)aluminum, bis(2-methyl-8-quinolinolato)(3,5-di-t-butylphenolato)aluminum, bis(2-methyl-8-quinolinolato)(2,6-diphenylphenolato)aluminum, bis(2-methyl-8-quinolinolato)(2,4,6-triphenylphenolato)aluminum, bis(2-methyl-8-quinolinolato)(2,4,6-trimethylphenolato)aluminum, bis(2-methyl-8-quinolinolato)(2,4,5,6-tetramethylphenolato)aluminum, bis(2-methyl-8-quinolinolato)(1-naphtholato)aluminum, bis(2-methyl-8-quinolinolato)(2-naphtholato)aluminum, bis(2,4-dimethyl-8-quinolinolato)(2-phenylphenolato)aluminum, bis(2,Aluminum (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)-μ-oxo-bis(2-methyl-8-quinolinolate)aluminum, Aluminum bis(2,4-dimethyl-8-quinolinolate)-μ-oxo-bis(2,4-dimethyl-8-quinolinolate)aluminum, Aluminum bis(2-methyl-4-ethyl-8-quinolinolate)-μ-oxo-bis(2-methyl-4-ethyl-8-quinolinolate)aluminum, Aluminum bis(2-methyl-4-methoxy-8-quinolinolate)-μ-oxo-bis(2-methyl-4-methoxy-8-quinolinolate)aluminum, Aluminum bis(2-methyl-5-cyano-8-quinolinolate)-μ-oxo-bis(2-methyl-5-cyano-8-quinolinolate)aluminum, Aluminum bis(2-methyl-5-trifluoromethyl-8-quinolinolate)-μ-oxo-bis(2-methyl-5-trifluoromethyl-8-quinolinolate)aluminum, Beryllium bis(10-hydroxybenzo[h]quinoline), etc. are mentioned.,

[0520] This quinolinol-based metal complex can be produced using known raw materials and known synthesis methods.,

[0521] <Thiazole derivatives and benzothiazole derivatives> The thiazole derivative is, for example, a compound represented by the following formula (ETM-14-1).

Chemical formula

[0522] The benzothiazole derivative is, for example, a compound represented by the following formula (ETM-14-2).

Chemical formula

[0523] Each type of 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 "thiazole-based substituent" and "benzothiazole-based substituent" are such that the pyridyl in the "pyridine-based substituent" in Formula (ETM-2), Formula (ETM-2-1), and Formula (ETM-2-2) is replaced by the following thiazolyl or benzothiazolyl (* indicates the bonding position), and at least one hydrogen in the thiazole derivative and benzothiazole derivative may be replaced by deuterium.

[0524]

Chemical Structure

[0525] Φ is further preferably an anthracene ring or a fluorene ring. In this case, the structure can cite the description in Formula (ETM-2-1) or Formula (ETM-2-2), and R 11 ~R 18 in each formula can cite the description in Formula (ETM-2-1) or Formula (ETM-2-2). Also, in Formula (ETM-2-1) or Formula (ETM-2-2), although two pyridine-based substituents are described in a bonded form, when substituting these with thiazole-based substituents (or benzothiazole-based substituents), both pyridine-based substituents may be replaced by thiazole-based substituents (or benzothiazole-based substituents) (i.e., n = 2), or one of the pyridine-based substituents may be replaced by a thiazole-based substituent (or benzothiazole-based substituent), and the other pyridine-based substituent may be replaced by R 11 ~R 18 (i.e., n = 1). Also, for example, at least one of R 11 ~R 18 in Formula (ETM-2-1) is replaced by a thiazole-based substituent (or benzothiazole-based substituent), and the "pyridine-based substituent" is R11 ~R 18 may be replaced with.

[0526] These thiazole derivatives or benzothiazole derivatives can be produced using known raw materials and known synthesis methods.

[0527] <Sirole derivative> The sirole derivative is, for example, a compound represented by the following formula (ETM-15). Details are described in JP-A-9-194487. [Chemical formula]

[0528] X and Y are each independently alkyl, cycloalkyl, alkenyl, alkynyl, alkoxy, alkenyloxy, alkynyloxy, aryl, or heteroaryl, and these may be substituted. For details of these groups, the descriptions in formula (1) and formula (ETM-7-2) can be further cited. Also, alkenyloxy and alkynyloxy are groups in which the alkyl part in alkoxy is substituted with alkenyl or alkynyl, and for details of these alkenyl and alkynyl, the description in formula (ETM-7-2) can be cited.

[0529] Also, X and Y, both being alkyl, may combine to form a ring.

[0530] R 1 ~R 4Each 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 between adjacent substituents.

[0531] R 1 ~R 4 For the details of halogen, alkyl, cycloalkyl, alkoxy, aryloxy, amino, aryl, heteroaryl, alkenyl, and alkynyl in, the description in formula (1) can be cited.

[0532] R 1 ~R 4 For the details of alkyl, aryl, and alkoxy among alkylcarbonyl, arylcarbonyl, alkoxycarbonyl, aryloxycarbonyl, alkylcarbonyloxy, arylcarbonyloxy, alkoxycarbonyloxy, and aryloxycarbonyloxy in, the description in formula (1) can also be cited.

[0533] Examples of silyl include a silyl group and a group in which at least one of the three hydrogens of the silyl group is independently substituted with aryl, alkyl, or cycloalkyl. Tri-substituted silyl is preferred, and examples include triarylsilyl, trialkylsilyl, tricycloalkylsilyl, dialkylcycloalkylsilyl, and alkyldicycloalkylsilyl. For the details of aryl, alkyl, and cycloalkyl in these, the description in formula (1) can be cited.

[0534] The condensed ring formed between adjacent substituents is, for example, R 1 and R 2 、R 2 and R 3 、R 3 and R 4 etc. are conjugated or non-conjugated condensed rings formed between them. These condensed rings may contain nitrogen, oxygen, or sulfur atoms in the ring structure and may be further condensed with other rings.

[0535] However, preferably, when R 1 and R 4 are phenyl, X and Y are not alkyl or phenyl. Also, preferably, when R 1 and R 4 are thienyl, X and Y are alkyl, and when R 2 and R 3 are alkyl, aryl, alkenyl, or a cycloalkyl in which R 2 and R 3 are bonded to form a ring, they do not simultaneously satisfy the structure. Also, preferably, when R 1 and R 4 are silyl groups, R 2 、R 3 、X, and Y are each independently not hydrogen or alkyl having 1 to 6 carbon atoms. Also, preferably, when R 1 and R 2 are in a structure where a benzene ring is condensed, X and Y are not alkyl and phenyl.

[0536] These silole derivatives can be produced using known raw materials and known synthesis methods.

[0537] <Azoline derivative> The azoline derivative is, for example, a compound represented by the following formula (ETM-16). Details are described in International Publication No. 2017 / 014226.

Chemical formula

[0538] 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 heterocyclic ring having 2 to 40 carbon atoms, and at least one hydrogen in Φ may be substituted with an alkyl having 1 to 6 carbon atoms, a cycloalkyl having 3 to 14 carbon atoms, an aryl having 6 to 18 carbon atoms, or a heteroaryl having 2 to 18 carbon atoms, Y is independently -O-, -S-, or >N-Ar, Ar is an aryl having 6 to 12 carbon atoms or a heteroaryl having 2 to 12 carbon atoms, and at least one hydrogen in Ar may be substituted with an alkyl having 1 to 4 carbon atoms, a cycloalkyl having 5 to 10 carbon atoms, an aryl having 6 to 12 carbon atoms, or a heteroaryl having 2 to 12 carbon atoms, R 1 ~R 5 are independently hydrogen, an alkyl having 1 to 4 carbon atoms, or a cycloalkyl having 5 to 10 carbon atoms, provided that Ar in the >N-Ar and the R 1 ~R 5 any one of which is a site bonded 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),

Chemical formula

[0539] Specific azoline derivatives are compounds represented by the following formula (ETM-16-1) or formula (ETM-16-2).

Chemical formula

[0540] Among formula (ETM-16-1) and formula (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 heterocyclic ring having 2 to 40 carbon atoms. At least one hydrogen of Φ may be substituted with an alkyl having 1 to 6 carbon atoms, a cycloalkyl having 3 to 14 carbon atoms, an aryl having 6 to 18 carbon atoms, or a heteroaryl having 2 to 18 carbon atoms, In formula (ETM-16-1), Y is, independently of each other, -O-, -S-, or >N-Ar, Ar is aryl having 6 to 12 carbon atoms or heteroaryl having 2 to 12 carbon atoms, and at least one hydrogen in Ar may be substituted with alkyl having 1 to 4 carbon atoms, cycloalkyl having 5 to 10 carbon atoms, aryl having 6 to 12 carbon atoms, or heteroaryl having 2 to 12 carbon atoms. In formula (ETM-16-1), R 1 ~R 4 are each independently hydrogen, alkyl having 1 to 4 carbon atoms, or cycloalkyl having 5 to 10 carbon atoms, provided that R 1 and R 2 are the same, and R 3 and R 4 are the same. In formula (ETM-16-2), R 1 ~R 5 are each independently hydrogen, alkyl having 1 to 4 carbon atoms, or cycloalkyl having 5 to 10 carbon atoms, provided that R 1 and R 2 are the same, and R 3 and R 4 are the same. In formula (ETM-16-1) and formula (ETM-16-2), L is each 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).

Chemical formula

[0541] Preferably, Φ is selected from the group consisting of monovalent groups represented by the following formula (Φ1-1) to formula (Φ1-18), divalent groups represented by the following formula (Φ2-1) to formula (Φ2-34), trivalent groups represented by the following formula (Φ3-1) to formula (Φ3-3), and tetravalent groups represented by the following formula (Φ4-1) to formula (Φ4-2). At least one hydrogen in Φ may be substituted with alkyl having 1 to 6 carbon atoms, cycloalkyl having 3 to 14 carbon atoms, aryl having 6 to 18 carbon atoms, or heteroaryl having 2 to 18 carbon atoms.

[0542] [Chemical formula]

[0543] [Chemical formula]

[0544]

Chem.

[0545] In the formula, Z is >CR2, >N-Ar, >N-L, -O-, or -S-, and >CR 2 R in is, independently of each other, alkyl having 1 to 4 carbon atoms, cycloalkyl having 5 to 10 carbon atoms, aryl having 6 to 12 carbon atoms, or heteroaryl having 2 to 12 carbon atoms, and R may be bonded to each other to form a ring. Ar in >N-Ar is aryl having 6 to 12 carbon atoms or heteroaryl having 2 to 12 carbon atoms. L in >N-L is L in formula (ETM-16), formula (ETM-16-1), or formula (ETM-16-2). * in the formula indicates the bonding position.

[0546] Preferably, L is a divalent group of a ring selected from the group consisting of benzene, naphthalene, pyridine, pyrazine, pyrimidine, pyridazine, triazine, quinoline, isoquinoline, naphthyridine, phthalazine, quinoxaline, quinazoline, cinnoline, and pteridine, and at least one hydrogen in L may be substituted with alkyl having 1 to 4 carbon atoms, cycloalkyl having 5 to 10 carbon atoms, aryl having 6 to 10 carbon atoms, or heteroaryl having 2 to 10 carbon atoms.

[0547] Preferably, Ar in >N-Ar as Y or Z is selected from the group consisting of phenyl, naphthyl, pyridinyl, pyrazinyl, pyrimidinyl, pyridazinyl, triazinyl, quinolinyl, isoquinolinyl, naphthyridinyl, phthalazinyl, quinoxalinyl, quinazolinyl, cinnolinyl, and pteridinyl, and at least one hydrogen in Ar in >N-Ar as Y may be substituted with alkyl having 1 to 4 carbon atoms, cycloalkyl having 5 to 10 carbon atoms, or aryl having 6 to 10 carbon atoms.

[0548] Preferably, R 1 ~R 4 are each independently hydrogen, alkyl having 1 to 4 carbon atoms, or cycloalkyl having 5 to 10 carbon atoms, provided that R 1 and R 2 are the same, R 3 and R 4 are the same, and further, all of R 1 ~R 4 do not all become hydrogen at the same time, and m is 1 or 2. When m is 2, the group formed by the azoline ring and L is the same.

[0549] Specific examples of the azoline derivative include, for example, the following compounds. In the structural formula, "Me" represents methyl.

[0550]

Chemical formula

[0551] More preferably, Φ is selected from the group consisting of divalent groups represented by the following formula (Φ2-1), formula (Φ2-31), formula (Φ2-32), formula (Φ2-33), and formula (Φ2-34), and at least one hydrogen in Φ may be substituted with aryl having 6 to 18 carbon atoms. Among the following formulas, * indicates the bonding position.

[0552]

Chemical formula

[0553] L is a divalent group of a ring selected from the group consisting of benzene, pyridine, pyrazine, pyrimidine, pyridazine, and triazine, and at least one hydrogen in L may be substituted with alkyl having 1 to 4 carbon atoms, cycloalkyl having 5 to 10 carbon atoms, aryl having 6 to 10 carbon atoms, or heteroaryl 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 having 1 to 4 carbon atoms, a cycloalkyl having 5 to 10 carbon atoms, or an aryl having 6 to 10 carbon atoms. R 1 ~R 4 are each independently hydrogen, an alkyl having 1 to 4 carbon atoms, or a cycloalkyl having 5 to 10 carbon atoms, provided that R 1 and R 2 are the same, R 3 and R 4 are the same, and all of R 1 ~R 4 are not simultaneously hydrogen, and m is 2, and the group formed by the azoline ring and L is the same.

[0554] As other specific examples of the azoline derivative, for example, the following compounds can be mentioned. In the structural formula, "Me" represents methyl.

[0555]

Chemical formula

[0556] Regarding the details of alkyl, cycloalkyl, aryl, or heteroaryl in the above formulas defining this azoline derivative, the description in formula (1) can be cited. This azoline derivative can be produced using known raw materials and known synthesis methods.

[0557] <Reducing substance> The electron transport layer or the electron injection layer may further contain a substance capable of reducing the material forming the electron transport layer or the electron injection layer. As long as the reducing substance has a certain reducibility, various substances can be used. For example, at least one selected from the group consisting of alkali metals, alkaline earth metals, rare earth metals, oxides of alkali metals, halides of alkali metals, oxides of alkaline earth metals, halides of alkaline earth metals, oxides of rare earth metals, halides of rare earth metals, organic complexes of alkali metals, organic complexes of alkaline earth metals, and organic complexes of rare earth metals may preferably be used.

[0558] 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 eV to 2.5 eV), or Ba (2.52 eV). Substances with a work function of 2.9 eV or less are particularly preferred. Among these, more preferred reducing substances are alkali metals of K, Rb, or Cs, even more preferably Rb or Cs, and most preferably Cs. These alkali metals have particularly high reducing ability, and by adding a relatively small amount to the material forming the electron transport layer or the electron injection layer, an improvement in the emission luminance and an increase in the lifespan of the organic EL element can be achieved. Also, as reducing substances with a work function of 2.9 eV or less, combinations of two or more of these alkali metals are also preferred. In particular, combinations containing Cs, such as combinations of Cs and Na, Cs and K, Cs and Rb, or Cs and Na and K, are preferred. By containing Cs, the reducing ability can be efficiently exerted, and by adding it to the material forming the electron transport layer or the electron injection layer, an improvement in the emission luminance and an increase in the lifespan of the organic EL element can be achieved.

[0559] The above materials for the electron injection layer and the electron transport layer may also be used as electron layer materials in the form of a polymer compound obtained by polymerizing a reactive compound having a reactive substituent substituted thereon as a monomer, or a polymer crosslinked body thereof, or a pendant polymer compound obtained by reacting a main chain type polymer with the reactive compound, or a pendant polymer crosslinked body thereof. In this case, as the reactive substituent, the description in the polycyclic aromatic compound containing the structure represented by the formula (1) can be cited.

[0560] Details of the uses of such polymer compounds and polymer crosslinked bodies will be described later.

[0561] 3-1-7. Cathode in organic electroluminescent device The negative electrode (108) serves to inject electrons into the light emitting layer (105) through the electron injection layer (107) and the electron transport layer (106).

[0562] The material for forming the negative electrode (108) is not particularly limited as long as it is a substance capable of efficiently injecting electrons into the organic layer, but the same material as that for forming the positive electrode (102) may be used. Among them, metals such as tin, indium, calcium, aluminum, silver, copper, nickel, chromium, gold, platinum, iron, zinc, lithium, sodium, potassium, cesium, and magnesium, or alloys thereof (such as magnesium-silver alloy, magnesium-indium alloy, aluminum-lithium alloy such as lithium fluoride / aluminum, etc.) are preferred. In order to improve the electron injection efficiency and device characteristics, an alloy containing lithium, sodium, potassium, cesium, calcium, magnesium, or these low-order function metals is effective. However, these low-order function metals are generally unstable in the atmosphere in many cases. To improve this point, for example, a method of doping a trace amount of lithium, cesium, or magnesium into the organic layer and using a highly stable electrode is known. Other dopants such as inorganic salts such as lithium fluoride, cesium fluoride, lithium oxide, and cesium oxide can also be used. However, it is not limited thereto.

[0563] Also, 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, and inorganic substances such as silica, titania, and silicon nitride, polyvinyl alcohol, vinyl chloride, hydrocarbon-based polymer compounds, etc. The manufacturing methods of these electrodes are also not particularly limited as long as conduction can be achieved, such as resistance heating, electron beam evaporation, sputtering, ion plating, and coating.

[0564] 3-1-8. Binder that may be used in each layer The materials used for the above hole injection layer, hole transport layer, light-emitting layer, electron transport layer, and electron injection layer may form each layer alone, but as a polymer binder, polyvinyl chloride, polycarbonate, polystyrene, poly(N-vinylcarbazole), polymethyl methacrylate, polybutyl methacrylate, polyester, polysulfone, polyphenylene oxide, polybutadiene, hydrocarbon resin, ketone resin, phenoxy resin, polyamide, ethyl cellulose, vinyl acetate resin, ABS resin, polyurethane resin, etc. solvent-soluble resins, or phenolic resins, xylene resins, petroleum resins, urea resins, melamine resins, unsaturated polyester resins, alkyd resins, epoxy resins, silicone resins, etc. It is also possible to use them after dispersing them in curable resins.

[0565] 3-1-9. Manufacturing method of organic electroluminescent device Each layer constituting the organic EL element can be formed by making the material to constitute each layer into a thin film by methods such as evaporation method, resistance heating evaporation, electron beam evaporation, sputtering, molecular lamination method, printing method, spin coating method or casting method, coating method, etc. There is no particular limitation on the film thickness of each layer thus formed, and it can be appropriately set according to the properties of the material, but it is usually in the range of 2 nm to 5000 nm. The film thickness can usually be measured with a crystal oscillator type film thickness measuring device, etc. When thinning by the evaporation method, the evaporation conditions vary depending on the type of material, the intended crystal structure and association structure of the film, etc. The evaporation conditions are generally boat heating temperature +50°C to +400°C, vacuum degree 10 -6 Pa to 10 -3It is preferably set as appropriate within the range of Pa, deposition rate of 0.01 nm / second to 50 nm / second, substrate temperature of -150 °C to +300 °C, and film thickness of 2 nm to 5 μm.

[0566] When applying a DC voltage to the organic EL element thus obtained, it may be applied with the positive electrode as + and the negative electrode as -. When applying a voltage of about 2 V to 40 V, light emission can be observed from the transparent or semi-transparent electrode side (positive electrode or negative electrode, or both). Further, this organic EL element also emits light when a pulse current or an alternating current is applied. Also, the waveform of the alternating current to be applied may be arbitrary.

[0567] Next, as an example of a method for manufacturing an organic EL element, a method for manufacturing an organic EL element composed of a positive electrode / hole injection layer / hole transport layer / light-emitting layer composed of a host material and a dopant material / electron transport layer / electron injection layer / negative electrode will be described.

[0568] <Vapor deposition method> After forming a thin film of a positive electrode material on a suitable substrate by a vapor deposition method or the like to fabricate a positive electrode, thin films of a hole injection layer and a hole transport layer are formed on this positive electrode. A host material and a dopant material are co-evaporated thereon to form a thin film as a light-emitting layer, an electron transport layer and an electron injection layer are formed on this light-emitting layer, and further a thin film made of a negative electrode material is formed by a vapor deposition method or the like to serve as a negative electrode, whereby the target organic EL element is obtained. In the fabrication of the above organic EL element, it is also possible to fabricate in the reverse order of fabrication, that is, in the order of negative electrode, electron injection layer, electron transport layer, light-emitting layer, hole transport layer, hole injection layer, and positive electrode.

[0569] <Wet film formation method> The wet film formation method is carried out by preparing a low molecular compound capable of forming each organic layer of the organic EL element as a liquid composition for forming an organic layer and using this. When there is no appropriate organic solvent for dissolving this low molecular compound, an organic layer forming composition may be prepared from a reactive compound in which a reactive substituent is substituted in the low molecular compound, together with other monomers or main chain polymers having a solubility function and polymerized into a polymer compound.

[0570] The wet film formation method generally forms a coating film by undergoing a coating step of applying a composition for forming an organic layer on a substrate and a drying step of removing a solvent from the applied composition for forming an organic layer. When the polymer compound has a crosslinkable substituent (also referred to as a crosslinkable polymer compound), further crosslinking occurs during this drying step to form a polymer crosslinked body. Depending on the difference in the coating step, the method using a spin coater is called the spin coating method, the method using a slit coater is called the slit coating method, the method using a plate is called gravure, offset, reverse offset, flexographic printing method, the method using an inkjet printer is called the inkjet method, and the method of spraying in a mist form is called the spray method.

[0571] For the drying step, there are methods such as air drying, heating, and vacuum drying. The drying step may be performed only once, or may be performed multiple times using different methods and conditions. Also, for example, different methods may be used in combination, such as firing under reduced pressure.

[0572] The wet film formation method is a film formation method using a solution, for example, some printing methods (inkjet method), spin coating method, or casting method, coating method, etc. Different from the vacuum evaporation method, the wet film formation method does not require the use of an expensive vacuum evaporation apparatus and can form a film under atmospheric pressure. In addition, the wet film formation method enables large-area formation and continuous production, leading to a reduction in manufacturing costs.

[0573] On the other hand, when compared with the vacuum evaporation method, the wet film formation method may be difficult to laminate. When producing a laminated film using the wet film formation method, it is necessary to prevent the dissolution of the lower layer by the upper layer composition, and compositions with controlled solubility, crosslinking of the lower layer, and orthogonal solvents (solvents that do not dissolve in each other) are used. However, even when using these techniques, it may be difficult to use the wet film formation method for coating all films. Therefore, generally, a method is adopted in which the wet film formation method is used for only some layers and the remaining layers are formed by the vacuum evaporation method to fabricate an organic EL element. For example, the procedure for fabricating an organic EL element by partially applying the wet film formation method is shown below.

[0574] (Step 1) Film formation by vacuum evaporation method for the positive electrode (Step 2) Film formation by wet film formation method of the composition for forming a hole injection layer containing a material for the hole injection layer (Step 3) Film formation by wet film formation method of the composition for forming a hole transport layer containing a material for the hole transport layer (Step 4) Film formation by wet film formation method of the composition for forming a light-emitting layer containing a host material and a dopant material (Step 5) Film formation by vacuum evaporation method for the electron transport layer (Step 6) Film formation by vacuum evaporation method for the electron injection layer (Step 7) Film formation by vacuum evaporation method for the negative electrode By going through this procedure, an organic EL element composed of a positive electrode / hole injection layer / hole transport layer / light-emitting layer composed of a host material and a dopant material / electron transport layer / electron injection layer / negative electrode can be obtained.

[0575] Of course, for the electron transport layer and the electron injection layer, film formation may also be performed by a wet film formation method by using a composition for forming a layer containing a material for the electron transport layer and a material for the electron injection layer, respectively. In that case, it is preferable to use means for preventing dissolution of the underlying light-emitting layer or means for forming a film from the negative electrode side contrary to the above procedure.

[0576] <Other film formation methods> For film formation of the composition for forming an organic layer, laser induced thermal imaging (LITI) may be used. LITI is a method of heating and evaporating a compound attached to a substrate with a laser, and an organic layer forming composition may be used as the material applied to the substrate.

[0577] <Optional process> Before and after each step of film formation, appropriate treatment steps, cleaning steps and drying steps may be appropriately inserted. Examples of the treatment steps include exposure treatment, plasma surface treatment, ultrasonic treatment, ozone treatment, cleaning treatment using an appropriate solvent, and heat treatment. Also, a series of steps for fabricating a bank are included.

[0578] For the production of the bank, photolithography technology can be used. As bank materials that can be used for photolithography, positive resist materials and negative resist materials may be used. Also, patternable printing methods such as inkjet method, gravure offset printing, reverse offset printing, and screen printing can be used. At this time, permanent resist materials can also be used.

[0579] Examples of materials used for the bank include, but are not limited to, polysaccharides and their derivatives, homopolymers and copolymers of ethylenic monomers having hydroxyl groups, biopolymer compounds, polyacryloyl compounds, polyesters, polystyrenes, polyimides, polyamideimides, polyetherimides, polysulfides, polysulfones, polyphenylenes, polyphenyl ethers, polyurethanes, epoxy (meth) acrylates, melamine (meth) acrylates, polyolefins, cyclic polyolefins, acrylonitrile-butadiene-styrene copolymer polymers (ABS), silicone resins, polyvinyl chlorides, chlorinated polyethylenes, chlorinated polypropylenes, polyacetates, polynorbornenes, synthetic rubbers, fluoropolymers such as polyvinylidene fluoride, polytetrafluoroethylene, and polyhexafluoropropylene, copolymer polymers of fluoroolefin-hydrocarbon olefin, and fluorocarbon polymers.

[0580] <Composition for forming an organic layer used in the wet film-forming method> The composition for forming an organic layer is obtained by dissolving a low-molecular compound that may form each organic layer of an organic EL element or a high-molecular compound obtained by polymerizing the low-molecular compound in an organic solvent. For example, the composition for forming a light-emitting layer contains, as a first component, at least one polycyclic aromatic compound (or its high-molecular compound) that 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 for dissolving the first and second components in the composition, and during coating, it imparts a smooth and uniform surface shape due to the controlled evaporation rate of the third component itself.

[0581] <organic solvent> The composition for forming an organic layer contains at least one organic solvent. By controlling the evaporation rate of the organic solvent during film formation, the film-forming property, the presence or absence of defects in the coating film, the surface roughness, and the smoothness can be controlled and improved. Also, during film formation using the inkjet method, the ejection property can be controlled and improved by controlling the meniscus stability at the pinholes of the inkjet head. Furthermore, by controlling the drying rate of the film and the orientation of the derivative molecules, the electrical properties, light-emitting properties, efficiency, and lifetime of the organic EL element having an organic layer obtained from the composition for forming an organic layer can be improved.

[0582] (1) Physical properties of the organic solvent 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. When the boiling point is higher than 130°C, it is preferable from the viewpoint of the ejection property of the inkjet. Also, when the boiling point is lower than 300°C, it is preferable from the viewpoints of defects in the coating film, surface roughness, residual solvent, and smoothness. The organic solvent preferably has a configuration containing two or more organic solvents from the viewpoints of good inkjet ejection property, film-forming property, smoothness, and low residual solvent. On the other hand, in some cases, considering transportability, etc., the composition may be in a solid state by removing the solvent from the composition for forming an organic layer.

[0583] 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 GS ) of the good solvent (GS) is lower than the boiling point (BP PS ) of the poor solvent (PS), and the structure is particularly preferable.

[0584] By adding a high-boiling poor solvent, the low-boiling good solvent volatilizes first during film formation, the concentrations of the contents and the poor solvent in the composition increase, and rapid film formation is promoted. As a result, a coating film with few defects, small surface roughness, and high smoothness can be obtained.

[0585] The difference in solubility (S GS -S PS ) is preferably 1% or more, more preferably 3% or more, and even more preferably 5% or more. The difference in boiling point (BP PS -BP GS ) is preferably 10°C or more, more preferably 30°C or more, and even more preferably 50°C or more.

[0586] The organic solvent is removed from the coating film by a drying process such as vacuum, reduced pressure, or heating after film formation. When heating is performed, from the viewpoint of improving coating film formability, it is preferably performed at a temperature of at least one glass transition temperature (Tg) of the solute + 30°C or lower. Also, from the viewpoint of reducing residual solvents, it is preferably heated to at least one glass transition point (Tg) of the solute - 30°C or higher. Even if the heating temperature is lower than the boiling point of the organic solvent, since the film is thin, the organic solvent is sufficiently removed. Also, drying may be performed multiple times at different temperatures, or multiple drying methods may be used in combination.

[0587] (2) Specific examples of organic solvents Examples of the organic solvent used in the composition for forming the organic layer 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, hexan-2-ol, heptan-2-ol, octan-2-ol, decan-2-ol, dodecan-2-ol, cyclohexanol, 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-chlorobenzotrifluoride, 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, phenetole, benzodioxole, 4-methylanisole, s-butylbenzene, 3-methylanisole, 4-fluoro-3-methylanisole, cymene, 1,2,3-trimethylbenzene, 1,2-dichlorobenzene, 2-fluorobenzonitrile, 4-fluoroveratrole, 2,6-dimethylanisole, n-butylbenzene, 3-fluorobenzonitrile, decalin (decalin), 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, veratrole, 1,2,3,4-tetrahydronaphthalene, ethyl benzoate, n-hexylbenzene, propyl benzoate, cyclohexylbenzene, 1-methylnaphthalene, butyl benzoate, 2-methylbiphenyl, 3-phenoxytoluene, 2,2'-bipyridyl, 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, benzyl pentyl ether, benzyl hexyl ether, benzyl heptyl ether, benzyl octyl ether and the like, but are not limited thereto. Further, the solvent may be used singly or in combination.,

[0588] <Optional component> The composition for forming an organic layer may contain an optional component as long as its properties are not impaired. Examples of the optional component include a binder and a surfactant.,

[0589] (1) Binder The composition for forming an organic layer may contain a binder. The binder forms a film during film formation and at the same time bonds the obtained film to the substrate. In addition, among the compositions for forming an organic layer, it plays a role of dissolving, dispersing, and binding other components. Examples of the binder used in the composition for forming an organic layer include acrylic resin, polyethylene terephthalate, ethylene-vinyl acetate copolymer, ethylene-vinyl alcohol copolymer, acrylonitrile-ethylene-styrene copolymer (AES) resin, ionomer, chlorinated polyether, diallyl phthalate resin, unsaturated polyester resin, polyethylene, polypropylene, polyvinyl chloride, polyvinylidene chloride, polystyrene, polyvinyl acetate, Teflon, acrylonitrile-butadiene-styrene copolymer (ABS) resin, acrylonitrile-styrene copolymer (AS) resin, phenol resin, epoxy resin, melamine resin, urea resin, alkyd resin, polyurethane, and copolymers of the above resins and polymers, but are not limited thereto. The binder used in the composition for forming an organic layer may be only one type or a mixture of multiple types.

[0590] (2) Surfactant The composition for forming an organic layer may contain a surfactant, for example, for controlling the film surface uniformity of the composition for forming an organic layer and the hydrophilicity and liquid repellency of the film surface. Surfactants are classified into ionic and non-ionic types based on the structure of the hydrophilic group, and further classified into alkyl-based, silicon-based, and fluorine-based types based on the structure of the hydrophobic group. Also, from the molecular structure, it is classified into a single molecular system having a relatively small molecular weight and a simple structure and a polymer system having a large molecular weight and side chains or branches. Also, from the composition, it is classified into a single system and a mixed system in which two or more surfactants and a substrate are mixed. As the surfactant that can be used in the composition for forming an organic layer, all types of surfactants can be used.

[0591] Examples of surfactants include Polyflow No. 45, Polyflow KL-245, Polyflow No. 75, Polyflow No. 90, Polyflow No. 95 (trade names, manufactured by Kyoeisha Chemical Co., Ltd.), Disperbyk 161, Disperbyk 162, Disperbyk 163, Disperbyk 164, Disperbyk 166, Disperbyk 170, Disperbyk 180, Disperbyk 181, Disperbyk 182, BYK300, BYK306, BYK310, BYK320, BYK330, BYK342, BYK344, BYK346 (trade names, manufactured by Big Chemie Japan Co., Ltd.), KP-341, KP-358, KP-368, KF-96-50CS, KF-50-100CS (trade names, manufactured by Shin-Etsu Chemical Co., Ltd.), Surflon SC-101, Surflon KH-40 (trade names, manufactured by Seimi Chemical Co., Ltd.), Ftergent 222F, Ftergent 251, FTX-218 (trade names, manufactured by Neos Co., Ltd.), EFTOP EF-351, EFTOP EF-352, EFTOP EF-601, EFTOP EF-801, EFTOPEF-802 (trade 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 (trade name, manufactured by DIC Corporation), fluoroalkylbenzenesulfonate, fluoroalkylcarboxylate, fluoroalkylpolyoxyethylene ether, fluoroalkylammonium iodide, fluoroalkylbetaine, fluoroalkylsulfonate, diglycerin tetrakis(fluoroalkylpolyoxyethylene ether), fluoroalkyltrimethylammonium salt, fluoroalkylaminosulfonate, polyoxyethylene nonylphenyl 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, alkylbenzenesulfonate and alkyldiphenyl ether disulfonate.

[0592] Also, the surfactant may be used alone or in combination of two or more.

[0593] <Composition and Physical Properties of Composition for Forming Organic Layer> The content of each component in the composition for forming an organic layer is determined in consideration of the good solubility, storage stability, and film-forming property of each component in the composition for forming an organic layer, the good film quality of the coating film obtained from the composition for forming an organic layer, the good ejection property when the inkjet method is used, and the good electrical characteristics, light-emitting characteristics, efficiency, and lifespan of the organic EL element having the organic layer produced using the composition. For example, in the case of the composition for forming a light-emitting layer, the first component is preferably 0.0001% by mass to 2.0% by mass based on the total mass of the composition for forming a light-emitting layer, the second component is preferably 0.0999% by mass to 8.0% by mass based on the total mass of the composition for forming a light-emitting layer, and the third component is preferably 90.0% by mass to 99.9% by mass based on the total mass of the composition for forming a light-emitting layer.

[0594] More preferably, the first component is 0.005% by mass to 1.0% by mass based on the total mass of the composition for forming a light-emitting layer, the second component is 0.095% by mass to 4.0% by mass based on the total mass of the composition for forming a light-emitting layer, and the third component is 95.0% by mass to 99.9% by mass based on the total mass of the composition for forming a light-emitting layer. Even more preferably, the first component is 0.05% by mass to 0.5% by mass based on the total mass of the composition for forming a light-emitting layer, the second component is 0.25% by mass to 2.5% by mass based on the total mass of the composition for forming a light-emitting layer, and the third component is 97.0% by mass to 99.7% by mass based on the total mass of the composition for forming a light-emitting layer.

[0595] The composition for forming an organic layer can be produced by appropriately selecting methods such as stirring, mixing, heating, cooling, dissolving, and dispersing the aforementioned components using known methods. Further, after preparation, filtration, degassing (also referred to as degas), ion exchange treatment, and inert gas substitution / encapsulation treatment can be appropriately selected and carried out.

[0596] Regarding the viscosity of the composition for forming an organic layer, a higher viscosity results in better film-forming properties and better ejection properties when using the inkjet method. On the other hand, a lower viscosity makes it easier to form a thin film. In this regard, the viscosity of the composition for forming an organic layer is preferably 0.3 mPa·s to 3 mPa·s, more preferably 1 mPa·s to 3 mPa·s, at 25°C. In the present invention, the viscosity is a value measured using a cone and plate type rotational viscometer (cone plate type).

[0597] Regarding the surface tension of the composition for forming an organic layer, a lower surface tension results in better film-forming properties and a defect-free coating film. On the other hand, a higher surface tension results in better inkjet ejection properties. In this regard, the composition for forming an organic layer preferably has a surface tension of 20 mN / m to 40 mN / m, more preferably 20 mN / m to 30 mN / m, at 25°C. In the present invention, the surface tension is a value measured using the sessile drop method.

[0598] <Crosslinkable polymer compound: a compound represented by formula (XLP-1)> Next, the case where the above-mentioned polymer compound has a crosslinkable substituent will be described. Such a crosslinkable polymer compound is, for example, a compound represented by the following formula (XLP-1). [Chemical formula]

[0599] In formula (XLP-1), MUx, ECx, and k have the same definitions 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 the monovalent or divalent aromatic group having a crosslinkable substituent is 0.1 mass% to 80 mass% in the molecule. The content of the monovalent or divalent aromatic compound having a crosslinkable substituent is preferably 0.5 mass% to 50 mass%, more preferably 1 mass% to 20 mass%, in the molecule.

[0600] The crosslinkable substituent (XLS) is not particularly limited as long as it is a group capable of further crosslinking the above-mentioned polymer compound, but substituents having the following structures are preferred. * in each structural formula indicates the bonding position.

Chemical formula

[0601] L is independently a single bond, -O-, -S-, >C=O, -O-C(=O)-, alkylene having 1 to 12 carbon atoms, oxyalkylene having 1 to 12 carbon atoms, and polyoxyalkylene having 1 to 12 carbon atoms. Among the above substituents, groups represented by formula (XLS-1), formula (XLS-2), formula (XLS-3), formula (XLS-9), formula (XLS-10), or formula (XLS-17) are preferred, and groups represented by formula (XLS-1), formula (XLS-3), or formula (XLS-17) are more preferred.

[0602] Examples of the divalent aromatic compound having a crosslinkable substituent include compounds having the following partial structures.

Chemical formula

[0603]

Chemical formula

[0604]

Chemical formula

[0605]

Chemical formula

[0606] <Method for Producing Polymer Compound and Crosslinkable Polymer Compound> Regarding the production methods of high molecular compounds and crosslinkable high molecular compounds, the compounds represented by the formula (H3) and the compound represented by (XLP-1) will be described as examples. These compounds may be synthesized by appropriately combining known production methods. Examples of the solvent used in the reaction include aromatic solvents, saturated / unsaturated hydrocarbon solvents, alcohol solvents, ether solvents, etc., such as dimethoxyethane, 2-(2-methoxyethoxy)ethane, 2-(2-ethoxyethoxy)ethane, etc. Also, the reaction may be carried out in a two-phase system. When reacting in a two-phase system, a phase transfer catalyst such as a quaternary ammonium salt may be added as necessary.

[0607] When producing the compound of formula (H3) and the compound of (XLP-1), it may be produced in one step or through multiple steps. Also, it may be carried out by a batch polymerization method in which all the raw materials are put into the reaction vessel and then the reaction is started, or by a dropping polymerization method in which the raw materials are added dropwise to the reaction vessel, or by a precipitation polymerization method in which the product precipitates as the reaction progresses, or they may be synthesized by appropriately combining these. For example, when synthesizing the compound represented by the formula (H3) in one step, the monomer with a polymerizable group bonded to the monomer unit (MU) and the monomer with a polymerizable group bonded to the end cap unit (EC) are added to the reaction vessel and the reaction is carried out to obtain the target product. Also, when synthesizing the compound represented by the formula (H3) in multiple steps, the monomer with a polymerizable group bonded to the monomer unit (MU) is polymerized to a desired molecular weight, and then the monomer with a polymerizable group bonded to the end cap unit (EC) is added and reacted to obtain the target product. By adding monomers with polymerizable groups bonded to different types of monomer units (MU) in multiple steps and carrying out the reaction, a polymer having a concentration gradient with respect to the structure of the monomer unit can be produced. Also, after preparing the precursor polymer, the target polymer can be obtained by subsequent reactions.

[0608] Moreover, by selecting the polymerizable groups of the monomers, the primary structure of the polymer can be controlled. For example, as shown in Synthesis Schemes 1 to 3, it is possible to synthesize polymers having a random primary structure (Synthesis Scheme 1), polymers having a regular primary structure (Synthesis Schemes 2 and 3), etc., and they can be appropriately combined and used according to the target product. Furthermore, by using monomers having three or more polymerizable groups, hyperbranched polymers or dendrimers can be synthesized.

[0609]

Chemical formula

[0610] As the monomers that can be used in the present invention, they may be synthesized according to the methods described in JP-A 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, JP-A No. 2010-215886, JP-A No. 2008-106241, International Publication No. 2016 / 031639, and JP-A No. 2011-174062.

[0611] Regarding the specific polymer synthesis procedure, it may be synthesized according to the methods described in JP-A No. 2012-036388, International Publication No. 2015 / 008851, JP-A No. 2012-36381, JP-A 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.

[0612] 3-1-10. Application examples of organic electroluminescent device In addition, the present invention can also be applied to a display device including an organic EL element or a lighting device including an organic EL element, etc.

[0613] A display device or lighting device including an organic EL element can be manufactured by a known method such as connecting the organic EL element according to the present embodiment to a known driving device, and can be driven by appropriately using known driving methods such as direct current driving, pulse driving, and alternating current driving.

[0614] Examples of the display device include panel displays such as color flat panel displays, and flexible displays such as flexible color organic electroluminescence (EL) displays (see, for example, Japanese Patent Application Laid-Open No. 10-335066, Japanese Patent Application Laid-Open No. 2003-321546, Japanese Patent Application Laid-Open No. 2004-281086, etc.). Examples of the display method of the display include, for example, a matrix method and / or a segment method. Further, matrix display and segment display may coexist in the same panel.

[0615] In a matrix, pixels for display are two-dimensionally arranged in a lattice shape or a mosaic shape, and characters and images are displayed by a set of pixels. The shape and size of the pixels are determined according to the application. For example, for image and character display of a computer, monitor, or television, square pixels with a side length of 300 μm or less are usually used. In the case of a large display such as a display panel, pixels with a side length on the order of mm are used. In the case of monochrome display, pixels of the same color may be arranged, but in the case of color display, red, green, and blue pixels are arranged and displayed. In this case, typically, there are a delta type and a stripe type. And as the driving method of this matrix, either a line sequential driving method or an active matrix may be used. The line sequential driving has the advantage that the structure is simple, but considering the operating characteristics, the active matrix method may be superior in some cases, so it is also necessary to use them properly according to the application.

[0616] In the segment method (type), a pattern is formed to display predetermined information, and light is emitted from a predetermined area. For example, time and temperature display on a digital clock or thermometer, operation state display on an audio device or an electronic cooker, and panel display of an automobile are exemplified.

[0617] Examples of the lighting device include lighting devices such as indoor lighting, and backlights of liquid crystal display devices (see, for example, Japanese Patent Application Laid-Open Nos. 2003-257621, 2003-277741, 2004-119211, etc.). The backlight is mainly used for the purpose of improving the visibility of a display device that does not emit light by itself, and is used in liquid crystal display devices, watches, audio devices, automotive panels, display boards, and signs. In particular, as a backlight for a computer, which is a liquid crystal display device and for which thinning is an issue, considering that the conventional method consists of a fluorescent lamp and a light guide plate and thus it is difficult to thin it, the backlight using the light-emitting element according to the present embodiment is characterized by being thin and lightweight.

[0618] 3-2. Other organic devices In addition to the organic electroluminescent element described above, the polycyclic aromatic compound according to the present invention may also be used in the production of an organic field effect transistor or an organic thin film solar cell.

[0619] An organic field effect transistor is a transistor that controls current by an electric field generated by a voltage input, and in addition to a source electrode and a drain electrode, a gate electrode is provided. When a voltage is applied to the gate electrode, an electric field is generated, and it is a transistor that can arbitrarily block the flow of electrons (or holes) flowing between the source electrode and the drain electrode to control the current. Since the field effect transistor is easier to miniaturize than a simple transistor (bipolar transistor), it is often used as an element for constructing an integrated circuit or the like.

[0620] The structure of the organic field effect transistor usually has a source electrode and a drain electrode provided so as to be in contact with an organic semiconductor active layer formed using the polycyclic aromatic compound according to the present invention, and further, a gate electrode may be provided with an insulating layer (dielectric layer) in contact with the organic semiconductor active layer interposed therebetween. Examples of the element structure include the following structures.

[0621] (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 The organic field effect transistor configured as described above can be applied as a pixel driving switching element for a liquid crystal monitor or an organic light emitting element display using an active matrix driving method.

[0622] The organic thin film solar cell has a structure in which a positive electrode such as ITO, a hole transport layer, a photoelectric conversion layer, an electron transport layer, and a negative electrode are laminated on a transparent substrate such as glass. The photoelectric conversion layer has a p-type semiconductor layer on the positive electrode side and an n-type semiconductor layer on the negative electrode side. The polycyclic aromatic compound according to the present invention can be used as a material for the hole transport layer, the p-type semiconductor layer, the n-type semiconductor layer, and the electron transport layer according to its physical properties. The polycyclic aromatic compound according to the present invention can function as a hole transport material or an electron transport material in an organic thin film solar cell. In addition to the above, the organic thin film solar cell may appropriately include a hole blocking layer, an electron blocking layer, an electron injection layer, a hole injection layer, a smoothing layer, etc. Known materials used for organic thin film solar cells may be appropriately selected and combined for use in the organic thin film solar cell.

[0623] 4. Wavelength conversion material The polycyclic aromatic compound of the present invention may be used as a wavelength conversion material.

[0624] Currently, the technology of multi-color conversion by color conversion methods is actively being considered for application to liquid crystal monitors, organic EL displays, lighting, and the like. Color conversion means wavelength-converting the light emitted from a light emitter into light of a longer wavelength. For example, it refers to converting ultraviolet light or blue light into green light or red light emission. By forming a wavelength conversion material having this color conversion function into a film and combining it with, for example, a blue light source, it becomes possible to extract the three primary colors of blue, green, and red from the blue light source, that is, to extract white light. Using such a white light source that combines a blue light source and a wavelength conversion film having a color conversion function as a light source unit and combining it with a liquid crystal driving unit and a color filter makes it possible to manufacture a full-color display. Also, if there is no liquid crystal driving unit, it can be used as a white light source as it is and applied as a white light source for, for example, LED lighting. Further, 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 light and red light, it becomes possible to manufacture a full-color organic EL display that does not use a metal mask. Furthermore, by using a blue micro LED as a light source and combining it with a wavelength conversion film that converts blue light into green light and red light, it becomes possible to manufacture a low-cost full-color micro LED display.

[0625] The polycyclic aromatic compound of the present invention may be used as this wavelength conversion material. Using a wavelength conversion material containing the polycyclic aromatic compound of the present invention, light from a light source or light emitting element that generates ultraviolet light or blue light with a shorter wavelength can be converted into blue light or green light with high color purity suitable for use in a display device (a display device using an organic EL element or a liquid crystal display device). Adjustment of the color to be converted can be performed by appropriately selecting the substituents of the polycyclic aromatic compound of the present invention, the binder resin used as the wavelength conversion composition described later, and the like. The wavelength conversion material can be prepared as a wavelength conversion composition containing the polycyclic aromatic compound of the present invention. Also, a wavelength conversion film may be formed using this wavelength conversion composition.

[0626] 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 may be used. As other additives, the compounds described in paragraphs 0177 to 0181 of International Publication No. 2016 / 190283 may be used. For the solvent, reference can be made to the description of the solvent contained in the composition for forming the light-emitting layer described above.

[0627] The wavelength conversion film includes a wavelength conversion layer formed by curing the wavelength conversion composition. As a method for producing the wavelength conversion layer from the wavelength conversion composition, known film formation methods can be referred to. The wavelength conversion film may be composed only of a wavelength conversion layer formed from a composition containing the polycyclic aromatic compound of the present invention, or may include other wavelength conversion layers (for example, a wavelength conversion layer that converts blue light into green light or red light, a wavelength conversion layer that converts blue light or green light into red light). The wavelength conversion film may further include a substrate layer and a barrier layer for preventing deterioration of the color conversion layer due to oxygen, moisture, or heat.

Examples

[0628] Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited thereto.

[0629] <Synthesis Example> Synthesis Example (1): Synthesis of Compound (1-1)

Chemical Formula

[0630] To a flask containing compound (S-1-1) (1.5 g) and tert-butylbenzene (7.0 ml), 1.6 M tert-butyllithium pentane solution (1.6 ml) was added at -30 °C under a nitrogen atmosphere. After completion of the dropwise addition, the temperature was raised to 60 °C and stirred for 2 hours. Then, low-boiling components were removed by distillation under reduced pressure from tert-butylbenzene. After cooling to -30 °C, boron tribromide (0.63 g) was added, the temperature was raised to room temperature and stirred for 0.5 hour. Then, it was cooled to 0 °C again, N,N-diisopropylethylamine (0.43 ml) was added, stirred at room temperature until the exotherm subsided, then the temperature was raised to 120 °C and heated with stirring for 3 hours. The reaction solution was cooled to room temperature, an aqueous sodium acetate solution cooled in an ice bath was added, followed by heptane, and liquid separation was carried out. Subsequently, it was purified by a silica gel short-path column (eluent: toluene), and then the solvent was removed by distillation under reduced pressure. The obtained solid was dissolved in toluene, heptane was added for reprecipitation, and compound (1-1) (0.35 g) was obtained.

[0631] Compounds (1-2) to compound (1-17), compounds (Ref-1-1) to compounds (Ref-1-5) were synthesized by the method described in Synthesis Example (1). Compounds (Ref-1-1) to compounds (Ref-1-5) are compounds described in International Publication No. WO2022 / 328352 and were synthesized by the method according to the description of the said patent.

[0632]

Chemical formula

[0633]

Chemical formula

[0634]

Chemical formula

[0635]

Chemical formula

[0636] The generation of the target substance was confirmed by MALDI-TOF-MS (Matrix-Assisted Laser Desorption / Ionization Time-of-Flight Mass Spectrometry).

[0637]

Table 1

[0638] <Manufacture and Evaluation of Vapor Deposition-Type Organic EL Devices> Using each of the synthesized compounds of the present invention and comparative compounds, each organic EL device of TTF, TADF, TAF, and PSF was manufactured.

[0639] <TTF Structure: Examples 1-1-1 to 1-1-17 and Comparative Examples 1-1-1 to 1-1-5> ITO (120 nm) / HI (40 nm) / HAT-CN (5 nm) / HT-1 (45 nm) / HT-2 (10 nm) / BH: Each compound described in Table 2 (97:3) (25 nm) / ET-1 (5 nm) / ET-2:Liq (1:1) (25 nm) / LiF (1 nm) / Al (100 nm) The chemical structures of the compounds used in the manufacture of the above elements are shown below.

[0640]

Chemical Formula

[0641] A 26 mm × 28 mm × 0.7 mm glass substrate (manufactured by Opto Science Co., Ltd.) with ITO formed by sputtering to a thickness of 180 nm polished to 120 nm was used as a transparent support substrate. This transparent support substrate was fixed to the substrate holder of a commercially available vapor deposition apparatus (manufactured by Showa Vacuum Co., Ltd.), and molybdenum vapor deposition boats containing HI, HAT-CN, HT-1, HT-2, BH, each compound described in Table 2, ET-1, and aluminum nitride vapor deposition boats containing Liq, LiF, and aluminum were attached respectively.

[0642] The following layers are sequentially formed on the ITO film of the transparent support substrate. The vacuum chamber is evacuated to 5×10- 4 Pa, and first HI is heated and vapor-deposited to a film thickness of 40 nm, then HAT-CN is heated and vapor-deposited to a film thickness of 5 nm, then HT-1 is heated and vapor-deposited to a film thickness of 45 nm, then HT-2 is heated and vapor-deposited to a film thickness of 10 nm to form a hole layer composed of four layers. Next, BH and each compound described in Table 2 are simultaneously heated and vapor-deposited to a film thickness of 25 nm to form a light-emitting layer. The deposition rate was adjusted so that the mass ratio of BH to each compound described in Table 2 was about 97:3. Also, ET-1 was heated and vapor-deposited to a film thickness of 5 nm, and then ET-2 and Liq were simultaneously heated and vapor-deposited to a film thickness of 25 nm to form an electron layer composed of two layers. The deposition rate was adjusted so that the mass ratio of ET-2 to Liq was about 50:50. The deposition rate of each layer was 0.01 nm / second to 1 nm / second. Thereafter, LiF was heated and vapor-deposited at a deposition rate of 0.01 nm / second to 0.1 nm / second to a film thickness of 1 nm, and then aluminum was heated and vapor-deposited to a film thickness of 100 nm to form a negative electrode, obtaining an organic EL element.

[0643] <TADF configuration: Examples 2-1-1 to 2-1-17 and Comparative Examples 2-1-1 to 2-1-5> ITO(50 nm) / HAT-CN(10 nm) / HT-1(60 nm) / SiCzCz(5 nm) / SiCzCz:SiTrzCz2: each compound described in Table 2(60:39:1)(35 nm) / mSiTrz(5 nm) / mSiTrz:Liq(1:1)(30 nm) / LiF(1 nm) / Al(100 nm) A 26 mm×28 mm×0.7 mm glass substrate (manufactured by Opto Science Co., Ltd.) on which ITO with a film thickness of 200 nm was formed by sputtering and polished to 50 nm was used as the transparent support substrate. This transparent support substrate was fixed to the substrate holder of a commercially available vapor deposition apparatus (manufactured by Showa Vacuum Co., Ltd.), and molybdenum vapor deposition boats containing HAT-CN, HT-1, SiCzCz, SiTrzCz2, each compound described in Table 2, mSiTrz, and Liq, and tungsten vapor deposition boats containing LiF and aluminum were attached respectively.

[0644] The following layers were sequentially formed on the ITO film of the transparent support substrate. The vacuum chamber was evacuated to 5×10- 4 Pa, and first, HAT-CN was heated and vapor-deposited to a film thickness of 10 nm to form a hole injection layer. Next, HT-1 was heated and vapor-deposited to a film thickness of 60 nm to form a hole transport layer (1), and further, SiCzCz was heated and vapor-deposited to a film thickness of 5 nm to form a hole transport layer (2). Next, SiCzCz, SiTrzCz2, and each compound described in Table 2 were simultaneously heated and vapor-deposited to a film thickness of 35 nm to form a light-emitting layer. The deposition rate was adjusted so that the mass ratio of SiCzCz, SiTrzCz2, and each compound described in Table 2 was approximately 60:39:1. Next, mSiTrz was heated and vapor-deposited to a film thickness of 5 nm to form an electron transport layer (1), and further, mSiTrz and Liq were heated and vapor-deposited to a film thickness of 30 nm to form an electron transport layer (2). The deposition rate was adjusted so that the mass ratio of SiTrz and Liq was approximately 1:1. The deposition rate of each layer was 0.01 nm / second to 1 nm / second. Thereafter, LiF was heated and vapor-deposited at a deposition rate of 0.01 nm / second to 0.1 nm / second to a film thickness of 1 nm, and then aluminum was heated and vapor-deposited to a film thickness of 100 nm to form a negative electrode, obtaining an organic EL element. At this time, the deposition rate of aluminum was adjusted to be 1 nm / second to 10 nm / second. Also, SiCzCz in the light-emitting layer serves as a hole-transporting host material, and SiTrzCz2 serves as an electron-transporting host material.

[0645] <TAF configuration: Examples 3-1-1 to 3-1-17, Comparative Examples 3-1-1 to 3-1-5> ITO(50 nm) / HAT-CN(10 nm) / HT-1(60 nm) / SiCzCz(5 nm) / SiCzCz:SiTrzCz2:TADF-1: each compound described in Table 2 (60:26:13:1)(35 nm) / mSiTrz(5 nm) / mSiTrz:Liq(1:1)(30 nm) / LiF(1 nm) / Al(100 nm) Except for the light-emitting layer, it was fabricated in the same manner as the TADF structure. In the light-emitting layer, SiCzCz, SiTrzCz2, (TADF-1), and each compound described in Table 2 were simultaneously heated and vapor-deposited to a film thickness of 35 nm. The deposition rate was adjusted so that the mass ratio of SiCzCz, SiTrzCz2, (TADF-1), and each compound described in Table 2 was approximately 60:26:13:1.

[0646] <PSF structure: Examples 4-1-1 to 4-1-17, Comparative Examples 4-1-1 to 4-1-5> ITO(50 nm) / HAT-CN(10 nm) / HT-1(60 nm) / SiCzCz(5 nm) / SiCzCz:SiTrzCz2:PtON-TBBI: each compound described in Table 2(60:26:13:1)(35 nm) / mSiTrz(5 nm) / mSiTrz:Liq(1:1)(30 nm) / LiF(1 nm) / Al(100 nm) (TADF-1) of the TAF structure was replaced with PtON-TBBI, and the device was fabricated in the same manner.

[0647] The chemical structures of the compounds used in the manufacture of the above devices are shown below.

Chemical formula

[0648] [Evaluation] The evaluation items include driving voltage (V), emission wavelength (nm), CIE chromaticity (x, y), external quantum efficiency (%), maximum wavelength (nm) of the emission spectrum, and full width at half maximum (nm), etc. These evaluation items can use the values during emission, for example, at 1000 cd / m 2 The values during emission may also be used.

[0649] The quantum efficiency of a light-emitting device includes internal quantum efficiency and external quantum efficiency. The internal quantum efficiency indicates the ratio at which external energy injected as electrons (or holes) into the light-emitting layer of the light-emitting device is purely converted into photons. On the other hand, the external quantum efficiency is calculated based on the amount of photons emitted to the outside of the light-emitting device. Since some of the photons generated in the light-emitting layer are absorbed inside the light-emitting device or continue to be reflected and not emitted to the outside of the light-emitting device, the external quantum efficiency is lower than the internal quantum efficiency.

[0650] The measurement methods for spectral radiance (emission spectrum) and external quantum efficiency are as follows. Using a voltage / current generator R6144 manufactured by ADVANTEST, a voltage is applied to cause the device to emit light when the luminance of the device reaches 1000 cd / m 2 The spectral radiance in the visible light region is measured from the vertical direction with respect to the light-emitting surface using a spectral radiance meter SR-3AR manufactured by TOPCON. Assuming that the light-emitting surface is a perfect diffuser, the value of the spectral radiance of each wavelength component measured is divided by the wavelength energy and multiplied by π, and the resulting numerical value is the number of photons at each wavelength. Subsequently, the number of photons in the entire observed wavelength region is integrated to obtain the total number of photons emitted from the device. The numerical value obtained by dividing the applied current value by the elementary charge is taken as the number of carriers injected into the device, and the numerical value obtained by dividing the total number of photons emitted from the device by the number of carriers injected into the device is the external quantum efficiency. Also, the full width at half maximum of the emission spectrum is determined as the width between the upper and lower wavelengths centered on the maximum emission wavelength where the intensity becomes 50%.

[0651] A DC voltage is applied with the ITO electrode as the positive electrode and the LiF / aluminum electrode as the negative electrode, and the characteristics during light emission are measured when the luminance reaches 1000 cd / m 2 For the TTF-structured device, the time (lifetime) to maintain a luminance of 95% or more of the initial luminance was measured. For the TADF-structured, TAF-structured, and PSF-structured devices, the time (lifetime) to maintain a luminance of 50% or more of the initial luminance was measured. Also, the emission peak of all the devices was in the range of 450 nm to 470 nm. The results are shown in Table 2.

[0652]

Table 2

[0653] From the obtained results, it can be seen that the device of the example is highly efficient and has a long lifespan compared to the device of the comparative example using the compound having the corresponding skeleton to the compound of the example.

Explanation of Reference Signs

[0654] 100: Organic electroluminescent device 101: Substrate 102: Anode 103: Hole injection layer 104: Hole transport layer 105: Light-emitting layer 106: Electron transport layer 107: Electron injection layer 108: Cathode

Claims

1. A polycyclic aromatic compound represented by the following formula (1): 【Chemistry 1】 ring A, ring B, ring C, ring D, and ring E are independently a substituted or unsubstituted aryl ring, or a substituted or unsubstituted heteroaryl ring; with the proviso that at least one of ring A, ring B, ring C, ring D, and ring E is a substituted or unsubstituted monocyclic heteroaryl ring; provided that at least one of ring A, ring B, ring C, ring D, and ring E has a group represented by formula (2) as a substituent; Each L is independently a single bond, >O, or >N-R ＮＸ , >C(-R ＣＸ ) ２ , -C(-R ＣＸ )=C(-R ＣＸ )-, >Si(-R ＩＸ ) ２ , >S, >CO, >CS, >SO, >SO ２ , >SeO, >SeO ２ , >PO, >B(-R ＰＸ ), or >Se; R ＮＸ , R ＣＸ , R ＩＸ , and R ＰＸ are each independently hydrogen, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted alkyl, or substituted or unsubstituted cycloalkyl, ＣＸ may be bonded to each other to form a ring, and the two R ＩＸ may be bonded to each other to form a ring, In the above structure, at least one selected from the group consisting of an aryl ring and a heteroaryl ring may be fused to at least one cycloalkane, the cycloalkane may be substituted with at least one substituent, and at least one of the cycloalkanes is -CH ２ - may be replaced by -O-; In formula (2), * indicates the bonding position to the aryl ring or heteroaryl ring, Ring F is a substituted or unsubstituted aryl ring, or a substituted or unsubstituted heteroaryl ring; R is a substituted or unsubstituted aryl ring, a substituted or unsubstituted heteroaryl ring, a substituted or unsubstituted alkyl, or a substituted or unsubstituted cycloalkyl; In formula (1) and formula (2), at least one hydrogen may be replaced by deuterium, cyano or halogen, and at least one nitrogen is replaced by nitrogen-15 ( １５ N), at least one sulfur is sulfur-33 ( ３３ S), Sulfur-34 ( ３４ S), or sulfur-36 ( ３６ S), at least one oxygen is oxygen-17 ( １７ O), or oxygen-18 ( １８ O), at least one carbon is carbon-13 ( １３ C), at least one boron is boron-11 ( １１ B) may be substituted.

2. The polycyclic aromatic compound according to claim 1, represented by the following formula (1'): 【Chemistry 2】 In formula (1'), L is defined as L in formula (1), Z is independently -C(-R ＺＥ )= or -N=, with the proviso that at least one of Z is -N=; R ＺＥ are each independently selected from the group consisting of hydrogen, deuterium, a halogen, a cyano group, a nitro group, a substituted or unsubstituted silyl group, a substituted or unsubstituted amino group, a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 30 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, a substituted or unsubstituted heteroaryl group having 2 to 30 carbon atoms, and a group represented by formula (2'), with the proviso that the substituents substituted on adjacent atoms may be bonded to each other to form a ring, However, R ＺＥ At least one of the groups has a group represented by formula (2'): In formula (2'), R is the same as R in formula (2), and * is R ＺＥ represents the bonding position with

3. 3. The polycyclic aromatic compound according to claim 2, wherein R is a substituted or unsubstituted aryl ring, a substituted or unsubstituted heteroaryl ring, a substituted or unsubstituted alkyl, or a substituted or unsubstituted cycloalkyl.

4. The polycyclic aromatic compound according to claim 2, wherein formula (1') is represented by any one of the following chemical formulas (1'-1) to (1'-7): 【Chemistry 3】 In the chemical formulas (1'-1) to (1'-7), L is defined as L in formula (1), At least one ring has a group represented by formula (2) as a substituent.

5. The polycyclic aromatic compound according to claim 2, wherein the formula (1') is represented by the following formula (1"): 【Chemistry 4】 In formula (1″), Z is defined as in formula (1').

6. The polycyclic aromatic compound according to claim 5, wherein formula (1″) is represented by any one of the following chemical formulas (1″-1) to (1″-7): 【Chemistry 5】 In chemical formulas (1"-1) to (1"-7), At least one ring has a group represented by formula (2) as a substituent.

7. The polycyclic aromatic compound according to claim 5, wherein formula (1″) is represented by any one of the following chemical formulas (1″-1) to (1″-4), (1″-6) and (1″-7): 【Chemistry 6】 In the chemical formulas (1"-1) to (1"-4), (1"-6) and (1"-7), At least one ring has a group represented by formula (2) as a substituent.

8. The polycyclic aromatic compound according to claim 1, wherein formula (2) is represented by any one of the following chemical formulas (2-1) to (2-7): 【Chemistry 7】 In the chemical formulae (2-1) to (2-7), * indicates the bonding position to the aryl ring or heteroaryl ring.

9. The polycyclic aromatic compound according to claim 1 , wherein formula (1) is represented by any one of the following chemical formulas: 【Chemistry 8】 【Chemistry 9】

10. A pair of electrodes consisting of a positive electrode and a negative electrode; and an organic layer disposed between the pair of electrodes; The organic layer comprises the polycyclic aromatic compound according to any one of claims 1 to 9.

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

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

13. The organic electroluminescent device according to claim 12 , wherein the host material is an anthracene compound, a fluorene compound, or a dibenzochrysene compound.

14. The organic electroluminescent device according to claim 11, wherein the light-emitting layer comprises a host material, a thermally activated delayed fluorescent material or a phosphorescent material, and the polycyclic aromatic compound as a light-emitting dopant.

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