Polycyclic aromatic compound, polymer compound, material for organic device, organic electroluminescent element, display device, and lighting device

Abstract

A polycyclic aromatic compound, a polymer compound, a material for organic devices, an organic electroluminescent element, a display device, and a lighting device, which are useful as materials for organic devices. The present invention is characterized by having a structure comprising one or more structural units represented by formula (1) and containing a group represented by formula (X1) and a group represented by formula (X3) or a group represented by formula (X13) as X. (Ring A-Ring D and Ring G are aryl rings or heteroaryl rings, Y is > B-, Rbz is an ortho-substituted phenyl group, XD is > C = O, the other X is > N-ArX (ArX is an aryl group) or the like, the D ring of formula (X1) may be further bonded to the ring bonded to formula (X1) via a bonding group LD, the G ring may be further bonded to the ring bonded to formula (X3) via a bonding group LG, LD and LG are single bonds or the like, and X represents a hydrogen atom or the like. At least one selected from the group consisting of aryl rings and heteroaryl rings in the structure may be condensed by at least one cycloalkane). # imgabs0 #

Description

Technical Field

[0001] The present invention relates to a polycyclic aromatic compound and also to an organic device such as an organic electroluminescent element, a polymer compound, an organic field effect transistor, and an organic thin film solar cell, as well as a display device and a lighting device using the polycyclic aromatic compound. Background Art

[0002] In the past, display devices using light-emitting elements that perform electroluminescence have been studied in various ways because they can achieve power saving or thinning, and organic electroluminescent elements containing organic materials have been actively studied because they can be easily lightweight or large-scaled. In particular, the development of organic materials having luminous properties such as blue, which is one of the three primary colors of light, and the development of organic materials having charge transport capabilities including holes, electrons, etc. (having the possibility of becoming semiconductors or superconductors) have been actively studied so far, regardless of whether they are polymer compounds or low molecular weight compounds.

[0003] An organic electroluminescent element has a structure including a pair of electrodes including an anode and a cathode, and one or more layers disposed between the pair of electrodes and including an organic compound. The layers including the organic compound include a light-emitting layer, a charge transport / injection layer for transporting or injecting charges such as holes and electrons, and various organic materials suitable for these layers have been developed.

[0004] Among them, Patent Documents 1 to 3 disclose that polycyclic aromatic compounds containing boron are effectively used as materials for organic electroluminescent elements and the like.

[0005] [Prior art literature]

[0006] [Patent Document]

[0007] [Patent Document 1] International Publication No. 2015 / 102118

[0008] [Patent Document 2] International Publication No. 2018 / 212169

[0009] [Patent Document 3] International Publication No. 2020 / 251049 Summary of the invention

[0010] [Problems to be solved by the invention]

[0011] As described above, various materials have been developed as materials used in organic electroluminescence (EL) elements. However, in order to increase the selection of materials for organic EL elements, it is desired to develop a material containing a compound different from conventional ones.

[0012] An object of the present invention is to provide a novel compound which can be effectively used as a material for an organic device such as an organic EL element.

[0013] [Technical means to solve the problem]

[0014] The inventors have made great efforts to solve the above problems and found that it is possible to manufacture an organic EL element with high efficiency and high color purity by introducing a specific partial structure into a polycyclic aromatic compound containing boron as in the compounds described in Patent Documents 1 to 3. Moreover, based on the above insights, further repeated studies have been conducted to complete the present invention. That is, the present invention provides the following polycyclic aromatic compounds, and further provides organic device materials containing the following polycyclic aromatic compounds.

[0015] <1> A polycyclic aromatic compound having the following structure, wherein the structure is composed of one or more structural units represented by formula (1), and

[0016] contains at least one group represented by the formula (X1) and at least one group represented by the formula (X3) as X, or

[0017] Containing at least one group represented by formula (X13) as X;

[0018] [Chemistry 1]

[0019]

[0020] In formula (1),

[0021] Ring A, Ring B, and Ring C are each independently a substituted or unsubstituted aryl ring or a substituted or unsubstituted heteroaryl ring;

[0022] Y is >B-, >P-, >P(=O)-, >P(=S)-, >Al-, >Ga-, >As-, >Si(-R IY )-or>Ge(-R GY )-,

[0023] R IY and R GY are each independently a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted alkyl, or a substituted or unsubstituted cycloalkyl;

[0024] In each of formula (X1) and formula (X13),

[0025] Ring D is a substituted or unsubstituted aryl ring or a substituted or unsubstituted heteroaryl ring,

[0026] In each of formula (X1) and formula (X13), Rbz are independently hydrogen, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted alkyl, or substituted or unsubstituted cycloalkyl. In each of Formula (X3) and Formula (X13), X D is >C=O, >C=S, >S=O, >S(=O)2, or >P=O,

[0027] The position of the wavy line in the radical represented by each of Formula (X1), Formula (X3), and Formula (X13) is the bonding position of X to the A ring and the B ring, or the bonding position of X to the A ring and the C ring,

[0028] The group represented by formula (X1) is bonded at # to any ring to which the group represented by formula (X1) is bonded, and in the one ring, the bonding position of the group represented by formula (X1) at a wavy line and the bonding position at # are adjacent to each other,

[0029] In formula (X1), ring D can be bonded to the base L D The other ring to which the group represented by formula (X1) is bonded is further bonded, and its bonding position is adjacent to the bonding position of the group represented by formula (X1) in the other ring at a wavy line, L D are independently single bonds, >BR BL 、>NR NL 、>O、>S、>C(-R CL )2、>Si(-R IL )2 or >Se, R BL , R NL , R CL and R IL are each independently hydrogen, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted alkyl, or substituted or unsubstituted cycloalkyl, and the two R CL Can bond to each other to form a ring, two R IL Can bond to each other to form a ring,

[0030] R NL , R CL and R IL may be independently bonded to at least one of the A ring, the B ring, and the C ring via a linking group or a single bond;

[0031] In formula (X3), ring G is a substituted or unsubstituted aryl ring or a substituted or unsubstituted heteroaryl ring,

[0032] The group represented by formula (X3) is bonded at ## to any ring to which the group represented by formula (X3) is bonded, and in the one ring, the bonding position of the group represented by formula (X3) at a wavy line and the bonding position at ## are adjacent to each other,

[0033] G ring can be linked to the base L G The other ring to which the group represented by formula (X3) is bonded is further bonded, and its bonding position is adjacent to the bonding position of the group represented by formula (X3) in the other ring at a wavy line, L G With L D have the same meaning;

[0034] The group represented by formula (X13) is bonded to any ring to which the group represented by formula (X13) is bonded at #, and in the one ring, the bonding position of the group represented by formula (X13) at a wavy line and the bonding position at # are adjacent to each other, and it is bonded to another ring to which the group represented by formula (X13) is bonded at ##, and in the other ring, the bonding position of the group represented by formula (X13) at a wavy line and the bonding position at ## are adjacent to each other;

[0035] Each of the other Xs other than the group represented by formula (X1), formula (X3), or formula (X13) is independently a group represented by formula (X2), >N-Ar X 、>NR NX 、>O、>C(-R CX )2、>Si(-R IX )2,>S, or>Se,Ar X is a substituted or unsubstituted aryl group or a substituted or unsubstituted heteroaryl group, R NX is hydrogen, substituted or unsubstituted alkyl, or substituted or unsubstituted cycloalkyl, R CX and R IX are each independently hydrogen, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted alkyl, or substituted or unsubstituted cycloalkyl, and the two R CX Can bond to each other to form a ring, two R IX Can bond with each other to form a ring, R NX , R CX and R IX can be connected to the R NX , the R CX , or the R IX One or two bonds of the ring to which X is bonded,

[0036] [Chemistry 2]

[0037]

[0038] In formula (X2),

[0039] Ring F is a substituted or unsubstituted aryl ring or a substituted or unsubstituted heteroaryl ring,

[0040] L F are independently a single bond, >NR NL 、>O、>S、>C(-R CL )2、>Si(-R IL )2 or >Se, R NL , R CL and R IL are each independently hydrogen, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted alkyl, or substituted or unsubstituted cycloalkyl, and the two R CL Can bond to each other to form a ring, two R IL Can bond to each other to form a ring,

[0041] R NL , R CL and R IL may be independently bonded to at least one of the A ring, the B ring, and the C ring via a linking group or a single bond;

[0042] The position of the wavy line in the group represented by formula (X2) is the bonding position of X to the A ring and the B ring, or the bonding position of X to the A ring and the C ring,

[0043] The group represented by formula (X2) is bonded at * to any ring to which the group represented by formula (X2) is bonded, and in the one ring, the bonding position of the group represented by formula (X2) at a wavy line and the bonding position at * are adjacent to each other,

[0044] The F ring can be bonded to the L F2 The other ring to which the group represented by formula (X2) is bonded is further bonded, and its bonding position is adjacent to the bonding position of the group represented by formula (X2) in the other ring at a wavy line, L F2 With L F For the same meaning,

[0045] At least one of the aryl rings and heteroaryl rings 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-,

[0046] In the structure, at least one hydrogen may be replaced by deuterium, and at least one nitrogen may be replaced by nitrogen-15( 15 N) substituted, at least one sulfur may be replaced by sulfur-33( 33 S), sulfur-34 ( 34 S) or sulfur-36( 36 S), at least one oxygen may be replaced by oxygen-17( 17 O) or oxygen-18 ( 18O) substituted, at least one carbon may be substituted by carbon-13 ( 13 C) substituted, at least one boron may be substituted by boron-11 ( 11 B) Replacement.

[0047] <2> The polycyclic aromatic compound according to <1>, wherein X D It is >C=O or >C=S.

[0048] <3> The polycyclic aromatic compound according to <1> or <2>, comprising, as X, at least one group represented by the formula (X13).

[0049] <4> The polycyclic aromatic compound according to any one of <1> to <3>, comprising at least one D The group represented by the formula (X1) further bonded to another ring to which the group represented by the formula (X1) is bonded is X.

[0050] <5> The polycyclic aromatic compound according to any one of <1> to <4>, comprising at least one phenyl group as R bz , the phenyl group has substituents at at least two ortho positions, and the two substituents are independently substituted or unsubstituted aryl groups or substituted or unsubstituted heteroaryl groups.

[0051] <6> The polycyclic aromatic compound according to any one of <1> to <5>, which is composed of one structural unit represented by formula (1).

[0052] <7> The polycyclic aromatic compound according to <6>, which is represented by any of the following formulas;

[0053] [Chemistry 3]

[0054]

[0055] [Chemistry 4]

[0056]

[0057] In the formula, Me is a methyl group, tBu is a tert-butyl group, and Ad is a 1-adamantyl group.

[0058] <8> The polycyclic aromatic compound according to any one of <1> to <5>, which is represented by formula (1M2-1) and contains at least one group represented by formula (X1) and at least one group represented by formula (X3) as X, or contains at least one group represented by formula (X13) as X;

[0059] [Chemistry 5]

[0060]

[0061] In formula (1M2-1),

[0062] Ring A, Ring B, Ring C, Y, and X have the same meanings as Ring A, Ring B, Ring C, Y, and X in Formula (1), respectively; Ring B' is independently a substituted or unsubstituted aryl ring or a substituted or unsubstituted heteroaryl ring,

[0063] At least one of the aryl rings and heteroaryl rings 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-,

[0064] In the structure, at least one hydrogen may be replaced by deuterium, and at least one nitrogen may be replaced by nitrogen-15( 15 N) substituted, at least one sulfur may be replaced by sulfur-33( 33 S), sulfur-34 ( 34 S) or sulfur-36( 36 S), at least one oxygen may be replaced by oxygen-17( 17 O) or oxygen-18 ( 18 O) substituted, at least one carbon may be substituted by carbon-13 ( 13 C) substituted, at least one boron may be substituted by boron-11( 11 B) Replacement.

[0065] <9> The polycyclic aromatic compound according to <8>, which is represented by any of the following formulas;

[0066] [Chemistry 6]

[0067]

[0068] In the formula, Me is a methyl group and tBu is a tert-butyl group.

[0069] <10> A polymer compound obtained by polymerizing a reactive compound having a reactive substituent substituted in the polycyclic aromatic compound according to any one of <1> to <9> as a monomer, wherein the polymer compound has a number average molecular weight of 2000 to 1.0×10 8 .

[0070] <11> A material for an organic device, comprising the polycyclic aromatic compound according to any one of <1> to <9> or the polymer compound according to <10>.

[0071] <12> The material for an organic device according to <11>, wherein the material for an organic device is a material for an organic electroluminescent element, a material for an organic field effect transistor, a material for an organic thin-film solar cell, or a material for a wavelength conversion filter.

[0072] <13> An organic electroluminescent element comprising: a pair of electrodes including an anode and a cathode; and an organic layer disposed between the pair of electrodes, the organic layer containing the polycyclic aromatic compound according to any one of <1> to <9> or the polymer compound according to <10>.

[0073] <14> The organic electroluminescent element according to <13>, wherein the organic layer is a light-emitting layer.

[0074] <15> A display device or a lighting device, comprising the organic electroluminescent element according to <13> or <14>.

[0075] [Effects of the Invention]

[0076] According to the present invention, there is provided a novel polycyclic aromatic compound which is effectively used as a material for an organic device such as an organic electroluminescent element. The polycyclic aromatic compound of the present invention can be used to produce an organic device such as an organic electroluminescent element. BRIEF DESCRIPTION OF THE DRAWINGS

[0077] Figure 1 This is a schematic cross-sectional view showing an example of an organic electroluminescent element.

[0078] [Explanation of Symbols]

[0079] 100: Organic electroluminescent element

[0080] 101: Substrate

[0081] 102: Anode

[0082] 103: Hole injection layer

[0083] 104: Hole transport layer

[0084] 105: Luminous layer

[0085] 106: Electron transport layer

[0086] 107: Electron injection layer

[0087] 108: Cathode DETAILED DESCRIPTION

[0088] Hereinafter, the present invention will be described in detail. The description of the constituent elements described below is sometimes based on representative embodiments or specific examples, but the present invention is not limited to such embodiments. In addition, in this specification, the numerical range represented by "~" refers to the range including the numerical values ​​described before and after "~" as the lower limit and the upper limit. In addition, in this specification, the "hydrogen" in the description of the structural formula refers to "hydrogen atom (H)". Similarly, "carbon atom (C)" is sometimes referred to as "carbon".

[0089] In the present specification, "adjacent groups" refer to two groups respectively bonded to two adjacent atoms (two atoms directly bonded by a covalent bond) in a structural formula.

[0090] In the present specification, "Me" represents a methyl group, "Et" represents an ethyl group, "nBu" represents a normal butyl group, "tBu" represents a tertiary butyl group, "iBu" represents an isobutyl group, "secBu" represents a secondary butyl group, "nPr" represents a normal propyl group, "iPr" represents an isopropyl group, "tAm" represents a tert-amyl group, "2EH" represents a 2-ethylhexyl group, "tOct" represents a tert-octyl group, "Ph" represents a phenyl group, "Mes" represents mesityl (2,4,6-trimethylphenyl), "Ad" represents a 1-adamantyl group, "Tf" represents a trifluoromethanesulfonyl group, "TMS" represents a trimethylsilyl group, and "D" represents a deuterium group.

[0091] In this specification, an organic electroluminescent element may be referred to as an organic EL element.

[0092] In this specification, the chemical structure or substituent is sometimes represented by the carbon number, but the carbon number when the chemical structure is substituted with a substituent, or when the substituent is further substituted with a substituent, etc., refers to the carbon number of the chemical structure or the substituent, and does not refer to the total carbon number of the chemical structure and the substituent, or the total carbon number of the substituent and the substituent. For example, the so-called "substituent B with carbon number Y substituted by substituent A with carbon number X" means that "substituent A with carbon number X" is substituted on "substituent B with carbon number Y", and the carbon number Y is not the total carbon number of substituent A and substituent B. In addition, for example, the so-called "substituent B with carbon number Y substituted by substituent A" means that "substituent A (without carbon number limitation)" is substituted on "substituent B with carbon number Y", and the carbon number Y is not the total carbon number of substituent A and substituent B.

[0093] <Description of Ring and Substituent>

[0094] First, the details of the rings and substituents used in the present specification are described below.

[0095] Examples of the “aryl ring” in the present specification include an aryl ring having 6 to 30 carbon atoms, preferably an aryl ring having 6 to 16 carbon atoms, more preferably an aryl ring having 6 to 12 carbon atoms, and particularly preferably an aryl ring having 6 to 10 carbon atoms.

[0096] Specific examples of the "aryl ring" include a benzene ring that is a monocyclic ring system, a biphenyl ring that is a bicyclic ring system, a naphthalene ring and an indene ring that are a condensed bicyclic ring system, a terphenyl ring (meta-terphenyl, o-terphenyl, p-terphenyl) that is a tricyclic ring system, an acenaphthene ring, fluorene ring, phenanthren ring, anthracene ring that are a condensed tricyclic ring system, a triphenylene ring, a pyrene ring, a tetracene ring, The ring is a perylene ring, a pentacene ring, etc. of a condensed five-ring system. In addition, the fluorene ring, the benzofluorene ring, and the indene ring also include structures in which the fluorene ring, the benzofluorene ring, the cyclopentane ring, etc. are spiro-bonded. In addition, the fluorene ring, the benzofluorene ring, and the indene ring also include rings in which two of the two hydrogen atoms of the methylene group in the structure are replaced by alkyl groups such as methyl groups described later as the first substituent to form dimethylfluorene rings, dimethylbenzofluorene rings, dimethylindene rings, etc.

[0097] As the "heteroaryl ring" in the present specification, for example, a heteroaryl ring having 2 to 30 carbon atoms can be mentioned, preferably a heteroaryl ring having 2 to 25 carbon atoms, more preferably a heteroaryl ring having 2 to 20 carbon atoms, further preferably a heteroaryl ring having 2 to 15 carbon atoms, and particularly preferably a heteroaryl ring having 2 to 10 carbon atoms can be mentioned. In addition, as the "heteroaryl ring", for example, a heterocyclic ring containing 1 to 5 heteroatoms selected from oxygen, sulfur, nitrogen, boron, selenium, phosphorus, and tellurium as ring-constituting atoms other than carbon can be mentioned.

[0098] Specific examples of the "heteroaryl ring" include a pyrrole ring, an oxazole ring, an isoxazole ring, a thiazole ring, an isothiazole ring, an imidazole ring, an oxadiazole ring (such as a furazan 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 phenoxathiol ring, a phenoxazine ring, a phenothiazine ring, a phenazine ring, a phenazasiline ring, an indolizine ring, a furan ring, a benzofuran ring, an isobenzofuran ring, a dibenzofuran ring, Thiophene ring, benzothiophene ring, dibenzothiophene ring, thianthrene ring, indolecarbazole ring, benzindolecarbazole ring, dibenzoindolecarbazole ring, naphthobenzofuran ring, dioxin ring, dihydroacridine ring, xanthene ring, thioxanthene ring, dibenzodioxin ring, dioxaborinaphthoanthracene ring (5,9-dioxa-13b-bora-13bH-naphtho[3,2,1-de]anthracene) ring, etc.), benzoselenophene ring, dibenzoselenophene ring, azacarbazole ring, azadibenzothiophene ring, azadibenzofuran ring, azadibenzoselenophene ring, azatriphenylene ring, imidazoimidazole ring, indoloindole ring, benzofuranocarbazole ring, benzothiophenocarbazole ring, indenocarbazole ring and selenophenecarbazole ring, spiro[fluorene-9,9'-xanthene] ring, spirobis[siliconfluorene] ring, etc. In addition, among the dihydroacridine ring, xanthene ring and thioxanthene ring, two of the two hydrogen atoms of the methylene group in the structure are preferably substituted with an alkyl group such as a methyl group as described later as the first substituent to form a dimethyldihydroacridine ring, a dimethylxanthene ring, a dimethylthioxanthene ring, etc. In addition, bipyridine ring, phenylpyridine ring, pyridylphenyl ring as a bicyclic ring system, terpyridine ring, bipyridylphenyl ring, pyridylbiphenyl ring as a tricyclic ring system can also be listed as a "heteroaryl ring". In addition, the "heteroaryl ring" also includes a pyran ring.

[0099] In this specification, a substituent may be substituted with a further substituent. For example, a specific substituent may be described as "substituted or unsubstituted". This means that the specific substituent is substituted with at least one further substituent or is unsubstituted. In the same sense, it is sometimes referred to as "substitutable". In this specification, the specific substituent at this time may be referred to as a "first substituent" and the further substituent may be referred to as a "second substituent".

[0100] In the present specification, the substituent group Zα includes the substituents of the substituent group Z and the substituents represented by the formula (A30) described later.

[0101] In the present specification, the substituent group Z includes:

[0102] The aryl group may be substituted by at least one group selected from the group consisting of an aryl group, a heteroaryl group, an alkyl group, a cycloalkyl group, a cyano group and a halogen group,

[0103] The heteroaryl group may be substituted by at least one group selected from the group consisting of aryl, heteroaryl, alkyl, cycloalkyl, cyano and halogen.

[0104] The diarylamino group may be substituted by at least one group selected from the group consisting of an aryl group, a heteroaryl group, an alkyl group, a cycloalkyl group, a cyano group and a halogen group, and the two aryl groups in the diarylamino group may be bonded to each other via a linking group.

[0105] The diheteroarylamino group may be substituted by at least one group selected from the group consisting of an aryl group, a heteroaryl group, an alkyl group, a cycloalkyl group, a cyano group and a halogen group, and the two heteroaryl groups in the diheteroarylamino group may be bonded to each other via a linking group.

[0106] The arylheteroarylamino group may be substituted by at least one group selected from the group consisting of an aryl group, a heteroaryl group, an alkyl group, a cycloalkyl group, a cyano group and a halogen group, and the aryl group and the heteroaryl group in the arylheteroarylamino group may be bonded to each other via a linking group.

[0107] The diarylboryl group may be substituted by at least one group selected from the group consisting of an aryl group, a heteroaryl group, an alkyl group, a cycloalkyl group, a cyano group and a halogen group, and the two aryl groups in the diarylboryl group may be bonded via a single bond or a linking group.

[0108] The alkyl group may be substituted by at least one group selected from the group consisting of an aryl group, a heteroaryl group, a cycloalkyl group, a cyano group and a halogen group,

[0109] The cycloalkyl group may be substituted by at least one group selected from the group consisting of an aryl group, a heteroaryl group, an alkyl group, a cycloalkyl group, a cyano group and a halogen group,

[0110] The alkoxy group may be substituted by at least one group selected from the group consisting of an aryl group, a heteroaryl group, a cycloalkyl group, a cyano group and a halogen group,

[0111] The aryloxy group may be substituted by at least one group selected from the group consisting of aryl, heteroaryl, alkyl, cycloalkyl, cyano and halogen.

[0112] Substituted silyl, cyano and halogen.

[0113] The aryl group as the second substituent in each group of the substituent group Z may be further substituted by an aryl group, a heteroaryl group, an alkyl group, a cycloalkyl group, a cyano group or a halogen. Similarly, the heteroaryl group as the second substituent may be substituted by an aryl group, a heteroaryl group, an alkyl group, a cycloalkyl group, a cyano group or a halogen.

[0114] In the present specification, when referred to as a "substituent", the type of the substituent is not particularly limited, and unless otherwise specified, any substituent selected from the substituent group Z may be used. For example, when a "substituted or unsubstituted" group is substituted, the group may be substituted with at least one group selected from the substituent group Z.

[0115] In the present specification, the "aryl group" is, for example, an aryl group having 6 to 30 carbon atoms, and preferably an aryl group having 6 to 20 carbon atoms, an aryl group having 6 to 16 carbon atoms, an aryl group having 6 to 12 carbon atoms, or an aryl group having 6 to 10 carbon atoms.

[0116] Specific examples of the "aryl group" include a monovalent group obtained by removing one hydrogen atom from the above-mentioned "aryl ring". For example, it is a phenyl group which is a monocyclic ring, a biphenyl group (2-biphenyl, 3-biphenyl, or 4-biphenyl) which is a bicyclic ring, a naphthyl group (1-naphthyl or 2-naphthyl) which is a condensed bicyclic ring, a terphenyl group (m-terphenyl-2'-yl, m-terphenyl-4'-yl, m-terphenyl-5'-yl, o-terphenyl-3'-yl, o-terphenyl-4'-yl, p-terphenyl-2'-yl, m-terphenyl-2-yl, m-terphenyl-3-yl, m-terphenyl-4-yl, o-terphenyl-2-yl, o-terphenyl-3-yl, o-terphenyl-4-yl, p-terphenyl-2-yl, p-terphenyl-3-yl, or p-terphenyl-4-yl) which is a tricyclic ring, a condensed tricyclic acenaphthene group (1-, 3-, 4-, or 5- The invention also includes the following: a 1-, 2-, 3-, 4-, or 9-) group, a phenanthren-(1-, 2-, 3-, 4-, or 9-) group, a tetraphenyl group (5'-phenyl-m-terphenyl-2-yl, 5'-phenyl-m-terphenyl-3-yl, 5'-phenyl-m-terphenyl-4-yl, or m-quaterphenyl group) having a tetracyclic ring system, a triphenylene-(1-, 2-, or 4-) group, a pyrene-(1-, 2-, or 4-) group, or a tetracene-(1-, 2-, or 5-) group having a condensed tetracyclic ring system, or a perylene-(1-, 2-, or 3-) group, or a pentacene-(1-, 2-, 5-, or 6-) group having a condensed pentacyclic ring system. In addition, a monovalent group of spirofluorene and the like can be mentioned.

[0117] In addition, the aryl group serving as the second substituent also includes a structure in which the aryl group is substituted by at least one group selected from the group consisting of aryl groups such as phenyl (specific examples are the groups described above), alkyl groups such as methyl (specific examples are the groups described later), and cycloalkyl groups such as cyclohexyl or adamantyl (specific examples are the groups described later).

[0118] As an example thereof, there can be mentioned a group in which the 9-position of the fluorenyl group as the second substituent is substituted with an aryl group such as a phenyl group, an alkyl group such as a methyl group, or a cycloalkyl group such as a cyclohexyl group or an adamantyl group.

[0119] The “arylene group” is, for example, an arylene group having 6 to 30 carbon atoms, and preferably an arylene group having 6 to 20 carbon atoms, an arylene group having 6 to 16 carbon atoms, an arylene group having 6 to 12 carbon atoms, or an arylene group having 6 to 10 carbon atoms.

[0120] Specific examples of the "arylene group" include a divalent group obtained by removing one hydrogen atom from the above-mentioned "aryl group" (monovalent group).

[0121] The “heteroaryl group” is, for example, a heteroaryl group having 2 to 30 carbon atoms, preferably a heteroaryl group having 2 to 25 carbon atoms, a heteroaryl group having 2 to 20 carbon atoms, a heteroaryl group having 2 to 15 carbon atoms, or a heteroaryl group having 2 to 10 carbon atoms. The “heteroaryl group” contains, in addition to carbon atoms, one or more, preferably one to five heteroatoms selected from oxygen, sulfur, and nitrogen as ring-constituting atoms.

[0122] Specific examples of "heteroaryl" include monovalent groups formed by removing one hydrogen from the "heteroaryl ring". Examples include pyrrolyl, oxazolyl, isoxazolyl, thiazolyl, isothiazolyl, imidazolyl, oxadiazolyl, thiadiazolyl, triazolyl, tetrazolyl, pyrazolyl, pyridyl, pyrimidinyl, pyridazinyl, pyrazinyl, triazinyl, indolyl, isoindolyl, 1H-indazolyl, benzimidazolyl, benzoxazolyl, benzothiazolyl, 1H-benzotriazolyl, quinolyl, isoquinolyl, cinnolinyl, quinazolinyl, quinoxalinyl, phenanthrolinyl, phthalazinyl, naphthyridinyl, purinyl, pteridinyl, carbazolyl, acridinyl, phenoxathiol, phenoxazinyl, phenanthrolinyl, phenanthroline ... Thiazinyl, phenazinyl, phenazasilinyl, indolizinyl, furanyl, benzofuranyl, isobenzofuranyl, dibenzofuranyl, naphthobenzofuranyl, thienyl, benzothienyl, isobenzothienyl, dibenzothienyl, naphthobenzothienyl, a monovalent group of a benzophospholine oxide ring, a monovalent group of a dibenzophospholine oxide ring, furazanyl, thianthrenyl, indolecarbazolyl, benzindolecarbazolyl, dibenzoindolecarbazolyl, imidazolinyl, or oxazolinyl, etc. In addition, a monovalent group of spiro[fluorene-9,9'-xanthene], a monovalent group of spirobis[silicon fluorene], and a monovalent group of benzoselenophene can be mentioned.

[0123] In addition, the heteroaryl group as the second substituent also includes a structure in which the heteroaryl group is substituted by at least one group selected from the group consisting of aryl groups such as phenyl (specific examples are the groups described above), alkyl groups such as methyl (specific examples are the groups described later), and cycloalkyl groups such as cyclohexyl or adamantyl (specific examples are the groups described later).

[0124] As an example, the 9-position of the carbazolyl group as the second substituent is substituted by an aryl group such as a phenyl group, an alkyl group such as a methyl group, or a cycloalkyl group such as a cyclohexyl group or an adamantyl group. In addition, a nitrogen-containing heteroaryl group such as a pyridyl group, a pyrimidyl group, a triazine group, a carbazolyl group, etc., which is further substituted by a phenyl group or a biphenyl group, is also included in the heteroaryl group as the second substituent.

[0125] The “heteroarylene group” is, for example, a heteroarylene group having 2 to 30 carbon atoms, preferably a heteroarylene group having 2 to 25 carbon atoms, a heteroarylene group having 2 to 20 carbon atoms, a heteroarylene group having 2 to 15 carbon atoms, or a heteroarylene group having 2 to 10 carbon atoms. In addition, the “heteroarylene group” is, for example, a divalent group such as a heterocycle containing 1 to 5 heteroatoms selected from oxygen, sulfur, and nitrogen as ring-constituting atoms in addition to carbon.

[0126] Specific examples of the "heteroarylene group" include a divalent group obtained by removing one hydrogen atom from the above-mentioned "heteroaryl group" (monovalent group).

[0127] The "diarylamino group" is an amino group substituted with two aryl groups, and the description of the above-mentioned "aryl group" can be referred to for details of the aryl group.

[0128] The "diheteroarylamino group" is an amino group substituted with two heteroaryl groups, and the description of the "heteroaryl group" can be referred to for details of the heteroaryl group.

[0129] The "arylheteroarylamino group" is an amino group substituted with an aryl group or a heteroaryl group, and the description of the above-mentioned "aryl group" and "heteroaryl group" can be cited for the details of the above-mentioned aryl group and heteroaryl group.

[0130] The two aryl groups in the diarylamino group as the first substituent may be bonded to each other via a linking group, the two heteroaryl groups in the diheteroarylamino group as the first substituent may be bonded to each other via a linking group, and the aryl and heteroaryl groups in the arylheteroarylamino group as the first substituent may be bonded to each other via a linking group. Here, the description of "bonding via a linking group" is as shown below, for example, it means that the two phenyl groups of the diphenylamino group form a bond through a linking group. In addition, the description is also applicable to the diheteroarylamino group and the arylheteroarylamino group formed by aryl or heteroaryl groups.

[0131] [Chemistry 7]

[0132]

[0133] Specific examples of the linking group include: >O, >NR X 、>C(-R X )2. -C(-R X )=C(-R X )-、>Si(-R X)2,>S,>CO,>CS,>SO,>SO2,>SeO,>SeO2,>PO,>B(-R X ) and >Se. R X are independently alkyl, cycloalkyl, aryl, or heteroaryl, which may be substituted by alkyl, cycloalkyl, aryl, or heteroaryl. X )2. -C(-R X )=C(-R X )-、>Si(-R X )2 Each of the two R X Can be linked to the group X via a single bond or Y bond to each other to form a ring. Y , can be listed as >O, >NR Y 、>C(-R Y )2、>Si(-R Y )2, >S, >CO, >CS, >SO, >SO2, and >Se, R Y are independently alkyl, cycloalkyl, aryl or heteroaryl, which may be substituted by alkyl, cycloalkyl, aryl or heteroaryl. Y is>C(-R Y )2 and>Si(-R Y )2, the two R Y The alkylene group may be substituted with an alkylene group. 2X Replacement, R 2X are independently alkyl, cycloalkyl, substituted silyl, aryl and heteroaryl, which may be substituted by alkyl, cycloalkyl, substituted silyl or aryl. X )=C(-R X )-The two Rs in X They may be bonded to each other and form an aryl ring (such as a benzene ring) or a heteroaryl ring together with these bonded C=C. X )=C(-R X )- can be an arylene group (such as 1,2-phenylene) or a heteroarylene group.

[0134] In addition, when simply describing “diarylamino”, “diheteroarylamino” or “arylheteroarylamino” in the present specification, unless otherwise specified, descriptions such as “two aryl groups in the diarylamino group may be bonded to each other via a linking group”, “two heteroaryl groups in the diheteroarylamino group may be bonded to each other via a linking group” and “the aryl and heteroaryl groups in the arylheteroarylamino group may be bonded to each other via a linking group” are respectively added.

[0135] "Diarylboryl" is a boron group substituted with two aryl groups, and the details of the aryl group can be referred to the description of the "aryl group". In addition, the two aryl groups may be bonded via a single bond or a linking group (for example, -CH=CH-, -CR=CR-, -C≡C-, >NR, >O, >S, >C=O, >C=S, >S=O, >S(=O)2, >Se(=O), >Se(=O)2, >P(=O), >B(-R), >C(-R)2, >Si(-R)2, or >Se). Here, R of -CR=CR-, R of >NR, R of >B(-R), R of >C(-R)2, and R of >Si(-R) are aryl, heteroaryl, diarylamino, alkyl, alkenyl, alkynyl, cycloalkyl, alkoxy, or aryloxy, and at least one hydrogen in the R may be further substituted by an aryl, heteroaryl, alkyl, alkenyl, alkynyl, or cycloalkyl. In addition, two adjacent Rs may be bonded to each other to form a ring, thereby forming a cycloalkylene, arylene, and heteroarylene. For details of the substituents listed here, the descriptions of "aryl", "arylene", "heteroaryl", "heteroarylene", and "diarylamino" described above, as well as the descriptions of "alkyl", "alkenyl", "alkynyl", "cycloalkyl", "cycloalkylene", "alkoxy", and "aryloxy" described later may be cited. In the present specification, when simply describing a "diarylboryl group", unless otherwise specified, it is assumed that "two aryl groups in the diarylboryl group may be bonded to each other via a single bond or a linking group" is included.

[0136] "Alkyl" can be any of straight chain and branched chain, for example, a straight chain alkyl group with 1 to 24 carbon atoms or a branched chain alkyl group with 3 to 24 carbon atoms, preferably an alkyl group with 1 to 18 carbon atoms (branched chain alkyl group with 3 to 18 carbon atoms), an alkyl group with 1 to 12 carbon atoms (branched chain alkyl group with 3 to 12 carbon atoms), an alkyl group with 1 to 6 carbon atoms (branched chain alkyl group with 3 to 6 carbon atoms), an alkyl group with 1 to 5 carbon atoms (branched chain alkyl group with 3 to 5 carbon atoms), an alkyl group with 1 to 4 carbon atoms (branched chain alkyl group with 3 to 4 carbon atoms), etc.

[0137] Specific examples of “alkyl” include methyl, ethyl, n-propyl, isopropyl, 1-ethyl-1-methylpropyl, 1,1-diethylpropyl, 1,1,2-trimethylpropyl, 1,1,2,2-tetramethylpropyl, 1-ethyl-1,2,2-trimethylpropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, 2-ethylbutyl, 1,1-dimethylbutyl, 3,3-dimethylbutyl, 1,1-diethylbutyl, 1-ethyl-1-methylbutyl, 1-propyl-1-methylbutyl, 1,1,3-trimethylbutyl, 1-ethyl-1,3-dimethylbutyl, n-pentyl, isopentyl, neopentyl, t-pentyl (t-amyl), 1-methylpentyl, 2-propylpentyl, 1,1-dimethylpentyl, 1-ethyl-1-methylpentyl, 1-propyl-1-methylpentyl, 1-butyl-1-methylpentyl, 1,1,4-trimethylpentyl, n-hexyl, 1-methylhexyl, 2-ethylhexyl, 1,1-dimethylhexyl, 1-ethyl-1-methylhexyl, 1,1,5-trimethylhexyl, 3,5,5-trimethylhexyl, n-heptyl, 1-methylheptyl, 1-hexylheptyl, 1,1-dimethylheptyl, 2,2-dimethylheptyl, 2,6-dimethyl-4-heptyl, n-octyl, tert-octyl (1,1,3,3-tetramethylbutyl), 1,1-dimethyloctyl, n-nonyl, n-decyl, 1-methyldecyl, n-undecyl, n-dodecyl, n-tridecyl, n-tetradecyl, n-pentadecyl, n-hexadecyl, n-heptadecyl, n-octadecyl, or n-icosyl.

[0138] The "alkylene group" is a divalent group obtained by removing any hydrogen atom from an "alkyl group", and examples thereof include a methylene group, an ethylene group, and a propylene group.

[0139] Regarding the "alkenyl group", please refer to the description of the "alkyl group". It is a group in which the CC single bond in the structure of the "alkyl group" is replaced by a C=C double bond, and also includes a group in which not only one but more than two single bonds are replaced by double bonds (also called a diene group or a triene group).

[0140] The "alkenylene group" is a divalent group obtained by removing any hydrogen atom of an "alkenyl group", and examples thereof include a vinylene group.

[0141] Regarding the “alkynyl group”, reference may be made to the description of the “alkyl group”, which is a group in which the C-C single bond in the structure of the “alkyl group” is replaced by a C≡C triple bond, and also includes a group in which not only one but two or more single bonds are replaced by triple bonds (also called a di-alkynyl group or a tri-alkynyl group).

[0142] The “cycloalkyl group” is, for example, a cycloalkyl group having 3 to 24 carbon atoms, preferably a cycloalkyl group having 3 to 20 carbon atoms, a cycloalkyl group having 3 to 16 carbon atoms, a cycloalkyl group having 3 to 14 carbon atoms, a cycloalkyl group having 3 to 12 carbon atoms, a cycloalkyl group having 5 to 10 carbon atoms, a cycloalkyl group having 5 to 8 carbon atoms, a cycloalkyl group having 5 to 6 carbon atoms, or a cycloalkyl group having 5 carbon atoms.

[0143] Specific examples of "cycloalkyl" include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl, or alkyl (especially methyl) substituents having 1 to 5 carbon atoms or 1 to 4 carbon atoms, bicyclo[1.1.0]butyl, bicyclo[1.1.1]pentyl, bicyclo[2.1.0]pentyl, bicyclo[2.1.1]hexyl, bicyclo[3.1.0]hexyl, bicyclo[2.2.1]heptyl (norbornyl), bicyclo[2.2.2]octyl, adamantyl, diadamantyl, decahydronaphthyl, or decahydroazulyl.

[0144] The “cycloalkylene group” is, for example, a cycloalkylene group having 3 to 24 carbon atoms, preferably a cycloalkylene group having 3 to 20 carbon atoms, a cycloalkylene group having 3 to 16 carbon atoms, a cycloalkylene group having 3 to 14 carbon atoms, a cycloalkylene group having 3 to 12 carbon atoms, a cycloalkylene group having 5 to 10 carbon atoms, a cycloalkylene group having 5 to 8 carbon atoms, a cycloalkylene group having 5 to 6 carbon atoms, or a cycloalkylene group having 5 carbon atoms.

[0145] Specific examples of the "cycloalkylene group" include a structure in which one hydrogen atom is removed from the above-mentioned "cycloalkyl group" (monovalent group) to give a divalent group.

[0146] The "cycloalkenyl group" includes a group having a structure in which at least one set of single bonds between two carbon atoms in the "cycloalkyl group" becomes a double bond (for example, a group in which -CH2-CH2- is substituted with -CH=CH-), and a group that is not equivalent to an aryl group. Specifically, 1-cyclohexenyl, 1-cyclopentenyl, etc. can be mentioned.

[0147] The "alkoxy group" is a group represented by "Alk-O-(Alk is an alkyl group)", and the description of the "alkyl group" can be cited for details of the alkyl group.

[0148] The "aryloxy group" is a group represented by "Ar-O-(Ar is an aryl group)", and the description of the "aryl group" can be cited for details of the aryl group.

[0149] The “substituted silyl group” is, for example, a silyl group substituted with at least one of an aryl group, an alkyl group, and a cycloalkyl group, and is preferably a triarylsilyl group, a trialkylsilyl group, a tricycloalkylsilyl group, a dialkylcycloalkylsilyl group, or an alkyldicycloalkylsilyl group.

[0150] The "triarylsilyl group" is a silyl group substituted with three aryl groups, and the description of the "aryl group" can be cited for details of the aryl groups.

[0151] Specific examples of the “triarylsilyl group” include triphenylsilyl, diphenylmononaphthylsilyl, monophenyldinaphthylsilyl, and trinaphthylsilyl groups.

[0152] The “trialkylsilyl group” is a silyl group substituted with three alkyl groups, and the description of the “alkyl group” mentioned above can be referred to for details of the alkyl groups.

[0153] Specific examples of “trialkylsilyl” include trimethylsilyl, triethylsilyl, tri-n-propylsilyl, triisopropylsilyl, tri-n-butylsilyl, triisobutylsilyl, tri-sec-butylsilyl, tri-tert-butylsilyl, ethyldimethylsilyl, n-propyldimethylsilyl, isopropyldimethylsilyl, n-butyldimethylsilyl, isobutyldimethylsilyl, sec-butyldimethylsilyl, tert-butyldimethylsilyl, methyldiethylsilyl, n-propyldimethylsilyl, tert-butyldiethylsilyl, methyldi-n-propylsilyl, ethyldi-n-propylsilyl, n-butyldi-n-propylsilyl, sec-butyldi-n-propylsilyl, tert-butyldi-n-propylsilyl, methyldiisopropylsilyl, ethyldiisopropylsilyl, n-butyldiisopropylsilyl, sec-butyldiisopropylsilyl, or tert-butyldiisopropylsilyl.

[0154] The "tricycloalkylsilyl group" is a silyl group substituted with three cycloalkyl groups, and the description of the "cycloalkyl group" mentioned above can be cited for the details of the cycloalkyl group.

[0155] Specific examples of the “tricycloalkylsilyl group” include tricyclopentylsilyl and tricyclohexylsilyl groups.

[0156] The "dialkylcycloalkylsilyl group" is a silyl group substituted with two alkyl groups and one cycloalkyl group, and the description of the "alkyl group" and the "cycloalkyl group" can be cited for details of the alkyl group and the cycloalkyl group.

[0157] The "alkyldicycloalkylsilyl group" is a silyl group substituted with one alkyl group and two cycloalkyl groups, and the description of the "alkyl group" and the "cycloalkyl group" can be cited for details of the alkyl group and the cycloalkyl group.

[0158] The "halogen" is fluorine, chlorine, bromine or iodine, preferably fluorine, chlorine or bromine, more preferably fluorine or chlorine, further preferably fluorine.

[0159] When the group is substituted with a cyano group or a halogen, it is also preferred that all or part of the hydrogen atoms in the aryl ring or the heteroaryl ring in the structure are substituted with a cyano group or a halogen.

[0160] The substituent represented by formula (A30) has the following structure.

[0161] [Chemistry 8]

[0162]

[0163] In formula (A30),

[0164] Ak is hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted cycloalkyl or substituted or unsubstituted cycloalkenyl, at least one -CH2- in the alkyl, cycloalkyl and cycloalkenyl may be substituted by -O- or -S-,

[0165] R Ak is a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted alkyl or a substituted or unsubstituted cycloalkyl, R Ak It can be bonded to Ak through a linking group or a single bond, and * is the bonding position.

[0166] In formula (A30), Ak is the substituent, and is not conjugated with the non-covalent electron pair on N, so that the non-covalent electron pair can be conjugated with the π electron of the bonding target, and a larger wavelength change can be achieved compared to the case where an aromatic group or the like exists at the same position. In addition, the same is true for the influence on the multiple resonance effect, and a greater improvement in the thermally activated delayed fluorescence (TADF) property can be achieved.

[0167] R Ak Preferred is an aryl group which may be substituted by an alkyl group or a cycloalkyl group, a heteroaryl group which may be substituted by an alkyl group or a cycloalkyl group, an alkyl group or a cycloalkyl group, more preferably an aryl group which may be substituted by an alkyl group, a heteroaryl group which may be substituted by an alkyl group, an alkyl group or a cycloalkyl group, further preferably an aryl group which may be substituted by an alkyl group, and particularly preferably a phenyl group which may be substituted by a methyl group.

[0168] In formula (A30), Ak is preferably an alkyl group having 1 to 6 carbon atoms or a cycloalkyl group having 3 to 14 carbon atoms, and is preferably an alkyl group having 1 to 4 carbon atoms or a cycloalkyl group having 3 to 8 carbon atoms, more preferably an alkyl group having 1 to 4 carbon atoms, and further preferably a methyl group.

[0169] R Ak It may be the same as or different from Ak, but is preferably different.

[0170] R Ak It can be bonded to Ak via a linking group or a single bond. Examples of the linking group include >O, >S, or >Si(-R)2. R of >Si(-R)2 is hydrogen, an aryl group having 6 to 12 carbon atoms, an alkyl group having 1 to 6 carbon atoms, or a cycloalkyl group having 3 to 14 carbon atoms. AkExamples of the structure bonded to Ak via a linking group or a single bond include the following structures.

[0171] [Chemistry 9]

[0172]

[0173] In the above formulas, * represents the bonding position.

[0174] <When two groups bonded to the same atom are bonded to each other>

[0175] In the present specification, when it is mentioned that two groups bonded to the same atom can be bonded to each other to form a ring, they can be bonded via a single bond or a linking group (these are also collectively referred to as a bonding group). Examples of the linking group include -CH2-CH2-, -CHR-CHR-, -CR2-CR2-, -CH=CH-, -CR=CR-, -C≡C-, -N(-R)-, -O-, -S-, -C(-R)2-, -C(=O)-, -C(=S)-, -S(=O)-, -S(=O)2-, -Se(=O)-, -Se(=O)2-, -P(=O)-, -B(-R)-, -Si(-R)2- or -Se-. For example, the following structures can be mentioned. In addition, the R of -CHR-CHR-, the R of -CR2-CR2-, the R of -CR=CR-, the R of -N(-R)-, the R of -C(-R)2-, the R of -B(-R)-, and the R of -Si(-R)2- are independently hydrogen, aryl which may be substituted by alkyl or cycloalkyl, heteroaryl which may be substituted by alkyl or cycloalkyl, alkyl which may be substituted by cycloalkyl, alkenyl which may be substituted by alkyl or cycloalkyl, alkynyl which may be substituted by alkyl or cycloalkyl, or cycloalkyl which may be substituted by alkyl or cycloalkyl. In addition, two adjacent Rs may be bonded to each other to form a ring, and may form a cycloalkylene group, an arylene group, or a heteroarylene group.

[0176] [Chemistry 10]

[0177]

[0178] As the bonding group, a single bond, -CR=CR-, -N(-R)-, -O-, -S-, -C(-R)2-, -Si(-R)2-, and -Se- are preferred as the linking group; a single bond, -CR=CR-, -N(-R)-, -O-, -S-, and -C(-R)2- are more preferred as the linking group; a single bond, -CR=CR-, -N(-R)-, -O-, and -S- are further preferred as the linking group; and a single bond is most preferred.

[0179] The position at which the two Rs are bonded via a bonding group is not particularly limited as long as it is a position at which bonding is possible, but it is preferred that the two Rs are bonded at the most adjacent position. For example, when the two groups are phenyl groups, it is preferred that the two Rs are bonded to each other at the ortho position (position 2) based on the bonding position (position 1) of "C" or "Si" in the phenyl group (refer to the structural formula).

[0180] <Stereoisomers, etc.>

[0181] The polycyclic aromatic compound of the present invention may exist as enantiomers or diastereomers depending on the type of substituents, but any stereoisomer in any pure form, any mixture of stereoisomers, racemates, etc. are all included in the scope of the present invention regardless of the structural formula described.

[0182] 1. Polycyclic aromatic compounds

[0183] <Description of the overall structure of the compound>

[0184] Regarding polycyclic aromatic compounds formed by linking aromatic rings using heteroelements such as boron, nitrogen, oxygen, and sulfur, it has been found that they have a large highest occupied molecular orbital (HOMO)-lowest unoccupied molecular orbital (LUMO) gap (band gap Eg in the film). The reason is that the aromaticity of the 6-membered ring containing the heteroelement is low, and the reduction of the HOMO-LUMO gap accompanying the expansion of the conjugated system is suppressed. In addition, it was found that the HOMO-LUMO gap can be arbitrarily changed according to the type of heteroelement and the method of connection. It is believed that the reason is that the energy of HOMO and LUMO can be arbitrarily changed according to the spatial expansion and energy of the empty orbital or lone pair of the heteroelement.

[0185] These polycyclic aromatic compounds cause the excited state singly occupied molecular orbital (SOMO) 1 and SOMO 2 to be localized on each atom due to the electronic disturbance of the heteroelement, thereby narrowing the half-value width of the fluorescence emission peak, and thus obtaining high color purity emission when used as a dopant for an organic EL element. S1T1 It becomes smaller and exhibits thermally activated delayed fluorescence. When used as an emitting dopant in an organic EL element, high efficiency can be obtained.

[0186] Furthermore, by introducing a substituent, the energies of HOMO and LUMO can be arbitrarily changed, and thus the ionization potential and the electron affinity can be optimized according to the surrounding materials.

[0187] The polycyclic aromatic compound of the present invention is equivalent to the polycyclic aromatic compound described above in which aromatic rings are linked by heteroelements such as boron, nitrogen, oxygen, and sulfur. The polycyclic aromatic compound of the present invention is a polycyclic aromatic compound having the following structure (hereinafter sometimes referred to as "polycyclic aromatic compound containing a structural unit represented by formula (1)"), wherein the structure is composed of one or more structural units represented by formula (1), and contains at least one group represented by formula (X1) and at least one group represented by formula (X3) as X, or contains at least one group represented by formula (X13) as X.

[0188] [Chemistry 11]

[0189]

[0190] The details of the symbols in each format will be described later.

[0191] <Description of Ring Structure in Compound>

[0192] In formula (1), "A", "B", "C" in the circle are symbols representing the ring structures represented by the circles. The structure represented by formula (1) has a structure in which at least three aromatic rings as ring A, ring B, and ring C are linked by heteroelements such as boron, oxygen, sulfur, or nitrogen to form a ring structure. The formed ring structure is a condensed ring structure consisting of at least 5 rings. The polycyclic aromatic compound of the present invention has a condensed ring structure consisting of at least 7 rings by further comprising at least one group represented by formula (X1) as X.

[0193] The A ring, the B ring, and the C ring are each independently a substituted or unsubstituted aryl ring or a substituted or unsubstituted heteroaryl ring.

[0194] Ring A forms a trivalent group having bonds on three consecutive atoms (preferably carbon) on the aryl ring or heteroaryl ring in its structure. Ring A is bonded to two X and Y via the three bonds. Ring A may also be bonded to a group represented by formula (X1), a group represented by formula (X2), or R NXThe ring in which the atoms having the three bonds are set as the ring-constituting atoms in ring A is preferably a 5-membered ring or a 6-membered ring, and more preferably a 6-membered ring. The ring may be further condensed with other rings. Examples of 6-membered rings include: benzene ring, pyridine ring, pyrazine ring, pyrimidine ring, etc. Examples of 6-membered rings further condensed with other rings include: naphthalene ring, quinoline ring, dibenzofuran ring, dibenzothiophene ring, carbazole ring, indene ring, etc. Examples of 5-membered rings include: furan ring, thiophene ring, pyrrole ring, thiazole ring, etc. Examples of 5-membered rings further condensed with other rings include: benzofuran ring, benzothiophene ring, indole ring, indene ring, etc. As aryl rings or heteroaryl rings in ring A, benzene rings are preferred.

[0195] Ring B and Ring C each form a divalent group having a bond on two atoms (preferably carbon) adjacent to each other on the aryl ring or heteroaryl ring in the structure. Ring B and Ring C are respectively bonded to X and Y via the two bonds. Ring B may also be bonded to a group represented by Formula (X1), a group represented by Formula (X2), or R NX In addition, the C ring may also be bonded with a group represented by formula (X1), a group represented by formula (X2), or R NX The ring in which the atoms having the two bonding bonds are set as the ring-constituting atoms in the B ring and the C ring is preferably a 5-membered ring or a 6-membered ring. The ring may be further condensed with other rings. Examples of 6-membered rings include: benzene ring, pyridine ring, pyrazine ring, pyrimidine ring, etc. Examples of 6-membered rings condensed with other rings include: naphthalene ring, quinoline ring, benzofuran ring, benzothiophene ring, indole ring, benzoselenophene ring, dibenzofuran ring, dibenzothiophene ring, carbazole ring, dibenzoselenophene ring, etc. Examples of 5-membered rings include: furan ring, thiophene ring, pyrrole ring, thiazole ring, selenophene ring, etc. Examples of 5-membered rings condensed with other rings include: benzofuran ring, benzothiophene ring, indole ring, benzoselenophene ring, indene ring, etc. As the aryl ring or heteroaryl ring in the B ring and the C ring, each independently is preferably a benzene ring, a dibenzofuran ring, a dibenzothiophene ring, or a carbazole ring, and more preferably a benzene ring.

[0196] In addition, as described later, in the polycyclic aromatic compound of the present invention having a structure composed of two or more structural units bonded in a shared ring, the A ring, the B ring or the C ring may have four or five bonding bonds. Such a structure is represented by the A' ring, the B' ring, or the C' ring in the formula (1M2-1), the formula (1M2-2), the formula (1M2-3), the formula (1M2-4), the formula (1M3-1), the formula (1M3-2), the formula (1M3-3), and the formula (1M3-4) described later, respectively.

[0197] Ring A, Ring B, and Ring C are each independently a substituted or unsubstituted aryl ring or a substituted or unsubstituted heteroaryl ring. In the substituted or unsubstituted aryl ring or substituted or unsubstituted heteroaryl ring in Ring A, Ring B, and Ring C of the structural unit represented by Formula (1), the substituent referred to as "substituted or unsubstituted (substituted or unsubstituted)" is preferably at least one substituent selected from the substituent group Zα. In addition, the substituent may be a substituted or unsubstituted diarylphosphino group such as a diphenylphosphino group. When a plurality of substituents are present, the plurality of substituents may be the same or different from each other. As the substituent, preferably a substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, a substituted or unsubstituted diarylamino group, or a substituent represented by formula (A30), more preferably an alkyl group, a phenyl group which may be substituted by an alkyl group, or a substituted or unsubstituted cycloalkyl group, and particularly preferably a methyl group, a tert-butyl group, a 1-adamantyl group, or a cyclohexyl group. In addition, regarding the substituent, reference can be made to the description of <Preferred Substituents> described later.

[0198] <Formula (X1), Formula (X13), Formula (X3)>

[0199] The polycyclic aromatic compound of the present invention contains at least one group represented by formula (X1) and at least one group represented by formula (X3) as X in its structure, or contains at least one group represented by formula (X13) as X. That is, the polycyclic aromatic compound of the present invention contains at least one -B(-R bz )- and at least one -X D -.

[0200] [Chemistry 12]

[0201]

[0202] The group represented by formula (X1), formula (X13), or formula (X3) is bonded to ring A at one of the two wavy lines, and is bonded to ring B or ring C at the other wavy line. That is, the bonding position of the wavy line is equivalent to the bonding position of X in formula (1) to ring A, ring B, or ring C. Furthermore, the group represented by formula (X1) is bonded to ring A or ring B or ring A or ring C to which the group is bonded at #, the group represented by formula (X3) is bonded to ring A or ring B or ring A or ring C to which the group is bonded at ##, and the group represented by formula (X13) is bonded to one of ring A and ring B or ring A and ring C at #, and is bonded to the other at ##. The position where the A ring, the B ring, and the C ring are bonded to the # or ## of the group represented by the formula (X1), the formula (X13), or the formula (X3) is a ring-constituting atom adjacent to the ring-constituting atom to which the group is bonded at the position of the wavy line. That is, when the A ring, the B ring, or the C ring to which the group represented by the formula (X1), the formula (X13), or the formula (X3) is bonded is a substituted or unsubstituted benzene ring, the polycyclic aromatic compound of the present invention becomes a compound having -B (-R) bonded to the meta position of Y. bz )-boron, or X D By making boron or X D Bonded to the meta position of Y, and making X D Bonding to the meta position of Y enhances the multiple resonance effect, emits light at a shorter wavelength, and has a narrower half-value width. bz )- and X D The increase in the number of ring contractions can suppress the stretching vibration of bonds that can lead to exciton deactivation, thereby improving the external quantum efficiency (EQE).

[0203] In formula (X1) and formula (X13), in particular, by using a group represented by formula (Rbz-1) described later as R bz , the plane formed by ring A to ring D and R bZ The planes of the aromatic rings in the cation are roughly orthogonal, and the boron can be stabilized by this steric hindrance. In addition, the boron can be stabilized by donating electrons to the empty orbital of the boron directly, through space, or through π / σ orbitals.

[0204] In formula (X1) and formula (X13), R bZ It is hydrogen, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted alkyl, or substituted or unsubstituted cycloalkyl, preferably substituted or unsubstituted aryl or substituted or unsubstituted heteroaryl, more preferably substituted aryl or substituted heteroaryl.

[0205] As R bZParticularly preferred examples include groups represented by formula (Rbz-1).

[0206] [Chemistry 13]

[0207]

[0208] In formula (Rbz-1), R ba is a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, a substituted or unsubstituted arylsilyl group, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted cycloalkyl group, R bb , R bc R is independently hydrogen, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted alkyl, or substituted or unsubstituted cycloalkyl. bb Preferably, R is a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted cycloalkyl group. ba and R bb Each is independently preferably a substituted or unsubstituted aryl group or a substituted or unsubstituted heteroaryl group.

[0209] Examples of the group represented by formula (Rbz-1) include the following substituents.

[0210] [Chemistry 14]

[0211]

[0212] [Chemistry 15]

[0213]

[0214] Among the groups represented by the formula (Rbz-1), a substituent corresponding to a substituted or unsubstituted m-terphenyl-2′-group is particularly preferred.

[0215] When the total number of the groups represented by the formula (X1) and the groups represented by the formula (X13) in the polycyclic aromatic compound containing the structural unit represented by the formula (1) is two or more, the plurality of R bZ The polycyclic aromatic compound containing the structural unit represented by formula (1) preferably contains at least one group represented by formula (Rbz-1) as R bZ .

[0216] In formula (X3) and formula (X13), X Dis >C=O, >C=S, >S=O, >S(=O)2 or >P=O. The polycyclic aromatic compound containing the structural unit represented by formula (1) can use the n-π* transition whose orbital angular motion is larger than the π-π* transition to undergo faster reverse intersystem crossing, and has high thermally active delayed fluorescence. In any one of formula (X3) and formula (X13), X D Preferred are >C=O, >C=S, >S=O, or >S(=O)2, more preferably >C=O, >C=S, or >S=O, further preferably >C=O or >C=S, and particularly preferably >C=O.

[0217] In formula (X1) and formula (X13), "D" is a symbol representing a ring structure represented by a circle, and the D ring is a substituted or unsubstituted aryl ring or a substituted or unsubstituted heteroaryl ring. When a plurality of D rings exist in a polycyclic aromatic compound containing a structural unit represented by formula (1), the plurality of D rings may be the same or different from each other.

[0218] The D ring in formula (X1) forms a divalent group having bonds on two atoms (preferably carbon) adjacent to each other on the aryl ring or heteroaryl ring in its structure. The D ring in formula (X1) is bonded to nitrogen and boron via the two bonds. The D ring may also be further bonded to the ring via a bonding group L as described later. D The D ring in formula (X13) forms a trivalent group having bonds to three atoms (preferably carbon) adjacent to each other on the aryl ring or heteroaryl ring in the structure. The D ring in formula (X13) is bonded to nitrogen, boron, and X through the three bonds. D Bond. The ring in which the atoms having the two or three bonding bonds are set as the ring-constituting atoms in the D ring is preferably a 5-membered ring or a 6-membered ring. The ring may be further condensed with other rings. Examples of 6-membered rings include: benzene ring, pyridine ring, pyrazine ring, pyrimidine ring, etc. Examples of 6-membered rings further condensed with other rings include: naphthalene ring, quinoline ring, benzofuran ring, benzothiophene ring, indole ring, benzoselenophene ring, dibenzofuran ring, dibenzothiophene ring, carbazole ring, dibenzoselenophene ring, etc. Examples of 5-membered rings include: furan ring, thiophene ring, pyrrole ring, thiazole ring, selenophene ring, etc. Examples of 5-membered rings further condensed with other rings include: benzofuran ring, benzothiophene ring, indole ring, benzoselenophene ring, etc. In addition, as a condensed ring, an indene ring may also be mentioned. The aryl ring or heteroaryl ring in the D ring is preferably a benzene ring, a pyridine ring, a pyrazine ring, or a pyrimidine ring, and more preferably a benzene ring.

[0219] The D ring is a substituted or unsubstituted aryl ring or a substituted or unsubstituted heteroaryl ring. Here, as the substituent mentioned in "substituted or unsubstituted (substituted or unsubstituted)", it is preferably at least one substituent selected from the substituent group Zα. In addition, the substituent may also be a substituted or unsubstituted diarylphosphino group such as a diphenylphosphino group. When there are multiple substituents, the multiple substituents may be the same or different from each other.

[0220] As the substituent, an alkyl group, a cycloalkyl group, an aryl group which may be substituted by an alkyl group or a cycloalkyl group, or a heteroaryl group which may be substituted by an alkyl group or a cycloalkyl group is more preferred, and a tert-butyl group, an adamantyl group, or a phenyl group which may be substituted by a tert-butyl group or an adamantyl group is further preferred. The substitution position is preferably the position farthest from the nitrogen (the nitrogen directly bonded to the A ring) (e.g., the para position) or the position farthest from -B (-R bz )-boron or X D The furthest position (for example, the para position) In addition, regarding the substituents, reference can be made to the description of "preferred substituents" described later.

[0221] The D ring is also preferably an unsubstituted aryl ring or an unsubstituted heteroaryl ring.

[0222] In addition, the D ring is also preferably a structure in which two groups respectively bonded to two adjacent carbon atoms on the aryl ring or heteroaryl ring in the structure are bonded to each other and form a cycloolefin ring together with the two carbon atoms. This structure is equivalent to a structure in which the aryl ring or heteroaryl ring is condensed by a cycloalkane as described later. Among them, it is particularly preferred that the two groups are bonded to each other to form a partial structure represented by the formula (B11) or formula (B12) described later.

[0223] The group represented by formula (X1) or formula (X13) is bonded to the A ring or B ring or the A ring or C ring to which the group is bonded at the wavy line position at #. The group represented by formula (X1) or formula (X13) is preferably bonded to the A ring at #. The reason for this is that the bond between the nitrogen located at the para position to the boron in formula (X1) and the adjacent atom can be expected to be stabilized.

[0224] The D ring in the group represented by formula (X1) can be further bonded to the group L D It is bonded to another ring (a ring different from the ring bonded at position #) to which the group represented by formula (X1) is bonded. D is a single bond, >BR BL 、>NR NL 、>O、>S、>C(-R CL )2、>Si(-R IL )2 or >Se, R BL , R NL , R CL and R ILare each independently hydrogen, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted alkyl, or substituted or unsubstituted cycloalkyl, and the two R CL Can bond to each other to form a ring, two R IL Can bond with each other to form a ring, R NL , R CL and R IL Each of the rings A, B, and C may be independently bonded to at least one of the rings A, B, and C via a linking group or a single bond.

[0225] When the D ring in the group represented by formula (X1) is bonded to the group L D When the group represented by the formula (X1) is bonded to a ring different from the ring to which the group represented by the formula (X1) is bonded at position #, the group represented by the formula (X1) can be represented by the following formula (X1-LD).

[0226] [Chemistry 16]

[0227]

[0228] In the formula (X1-LD), * represents a bonding position with another ring.

[0229] When the D ring in the group represented by formula (X1) is bonded to the group L D When the ring is bonded to a ring different from the ring to which the group represented by the formula (X1) is bonded at position #, L D , preferably a single bond, >NR NL 、>O、>S、>C(-R CL )2、>Si(-R IL )2 or >Se, more preferably a single bond, >O, >S or >Se, further preferably a single bond or >S, and most preferably a single bond.

[0230] The additional bonding position to the group represented by formula (X1) in each of rings A, B and C (the bonding position to the * in formula (X1-LD)) can be a ring-constituting atom adjacent to the ring-constituting atom to which the group represented by formula (X1) is bonded at the wavy line position.

[0231] In formula (X3), "G" is a symbol representing a ring structure represented by a circle, and the G ring is a substituted or unsubstituted aryl ring or a substituted or unsubstituted heteroaryl ring. When there are multiple groups represented by formula (X3), the multiple G rings may be the same or different from each other. In addition, the D ring and the G ring in formula (X1) or formula (X13) may be the same or different from each other.

[0232] The G ring in formula (X3) forms a divalent group having bonds on two atoms (preferably carbon) adjacent to each other on the aryl ring or heteroaryl ring in its structure. The G ring in formula (X3) is connected to nitrogen and X through the two bonds. D The G ring may also be further bonded via a bonding group L as described below. G Another ring bonded to the base represented by formula (X3) is bonded to form a trivalent group. The ring in which the atoms having the two bonding bonds are set as the ring-constituting atoms in the G ring is preferably a 5-membered ring or a 6-membered ring. The ring can be further condensed with other rings. Examples of 6-membered rings include: benzene ring, pyridine ring, pyrazine ring, pyrimidine ring, etc. Examples of 6-membered rings condensed with other rings include: naphthalene ring, quinoline ring, benzofuran ring, benzothiophene ring, indole ring, benzoselenophene ring, dibenzofuran ring, dibenzothiophene ring, carbazole ring, dibenzoselenophene ring, etc. Examples of 5-membered rings include: furan ring, thiophene ring, pyrrole ring, thiazole ring, selenophene ring, etc. Examples of 5-membered rings condensed with other rings include: benzofuran ring, benzothiophene ring, indole ring, benzoselenophene ring, etc. In addition, as a condensed ring, an indene ring can also be listed. The aryl ring or heteroaryl ring in the G ring is preferably a benzene ring, a pyridine ring, a pyrazine ring, or a pyrimidine ring, and more preferably a benzene ring.

[0233] Ring G is a substituted or unsubstituted aryl ring or a substituted or unsubstituted heteroaryl ring. Here, as the substituent mentioned in "substituted or unsubstituted (substituted or unsubstituted)", it is preferably at least one substituent selected from the substituent group Zα. In addition, the substituent may also be a substituted or unsubstituted diarylphosphino group such as a diphenylphosphino group. When there are multiple substituents, the multiple substituents may be the same or different from each other.

[0234] As the substituent, an alkyl group, a cycloalkyl group, an aryl group which may be substituted by an alkyl group or a cycloalkyl group, or a heteroaryl group which may be substituted by an alkyl group or a cycloalkyl group is more preferred, and a tert-butyl group, an adamantyl group, or a phenyl group which may be substituted by a tert-butyl group or an adamantyl group is further preferred. The substitution position is preferably the position farthest from the nitrogen (the nitrogen directly bonded to the A ring) (e.g., the para position) or the position farthest from the X D The furthest position (for example, the para position) In addition, regarding the substituents, reference can be made to the description of "preferred substituents" described later.

[0235] The G ring is also preferably an unsubstituted aryl ring or an unsubstituted heteroaryl ring.

[0236] In addition, the G ring is also preferably a structure in which two groups bonded to two adjacent carbon atoms on the aryl ring or heteroaryl ring in its structure are bonded to each other, and together with the two carbon atoms, form a cycloolefin ring. This structure is equivalent to a structure in which the aryl ring or heteroaryl ring is condensed by a cycloalkane as described later. Among them, it is particularly preferred that the two groups are bonded to each other to form a partial structure represented by the formula (B11) or formula (B12) described later.

[0237] The group represented by formula (X3) or formula (X13) is bonded at ## to the A ring or B ring to which the group is bonded at the wavy line position, or to the A ring or C ring. The group represented by formula (X13) is preferably bonded to the B ring or C ring at #.

[0238] The G ring in the group represented by formula (X3) can be further bonded to the group L G It is bonded to another ring (a ring different from the ring bonded at position #) to which the group represented by formula (X3) is bonded. G is a single bond, >BR BL 、>NR NL 、>O、>S、>C(-R CL )2、>Si(-R IL )2 or >Se, R BL , R NL , R CL and R IL are each independently hydrogen, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted alkyl, or substituted or unsubstituted cycloalkyl, and the two R CL Can bond to each other to form a ring, two R IL Can bond with each other to form a ring, R NL , R CL and R IL Each of the rings A, B, and C may be independently bonded to at least one of the rings A, B, and C via a linking group or a single bond.

[0239] When the G ring in the group represented by formula (X3) is connected to the group L G When the group represented by the formula (X3) is bonded to a ring different from the ring to which the group represented by the formula (X3) is bonded at position #, the group represented by the formula (X3) can be represented by the following formula (X3-LG).

[0240] [Chemistry 17]

[0241]

[0242] In the formula (X3-LG), * represents a bonding position with another ring.

[0243] As the G ring in the group represented by formula (X3) is connected via the bonding group L GWhen L is bonded to a ring different from the ring to which the group represented by formula (X3) is bonded at position # G , preferably a single bond, >NR NL 、>O、>S、>C(-R CL )2、>Si(-R IL )2 or >Se, more preferably a single bond, >O, >S or >Se, further preferably a single bond or >S, and most preferably a single bond.

[0244] The additional bonding position to the group represented by formula (X3) in each of rings A, B and C (the bonding position to the * in formula (X3-LG)) can be a ring-constituting atom adjacent to the ring-constituting atom to which the group represented by formula (X3) is bonded at the wavy line position.

[0245] In the polycyclic aromatic compound containing the structural unit represented by formula (1), -B (-R bz The number of -B(-R)- is 1 to (the number of X), preferably 1 to (the number of structural units represented by formula (1)), more preferably 1 or 2, and even more preferably 1. In a polycyclic aromatic compound containing a structural unit represented by formula (1), when there are multiple -B(-R bz )-, they may be the same or different. The position of X as the group represented by formula (X1) is not particularly limited. In the polycyclic aromatic compound containing the structural unit represented by formula (1), X derived from the group represented by formula (X3) or the group represented by formula (X13) D The number of is 1 to (the number of X), preferably 1 to (the number of structural units represented by formula (1)), more preferably 1 or 2, and still more preferably 1. In a polycyclic aromatic compound containing a structural unit represented by formula (1), when there are multiple X D , they may be the same as or different from each other.

[0246] From the viewpoint of ease of synthesis, the polycyclic aromatic compound containing the structural unit represented by formula (1) is preferably a compound in which all -B (-R bz )-derived from the group represented by formula (X1), and all -X D - is derived from the group represented by the formula (X3).

[0247] <Description of X (other than the group represented by formula (X1), formula (X3), or formula (X13))>

[0248] Each of the other Xs other than the group represented by formula (X1), formula (X3), or formula (X13) is independently a group represented by the following formula (X2), >N-Ar X 、>NR NX、>O、>C(-R CX )2、>Si(-R IX )2, >S, or >Se. Ar X is a substituted or unsubstituted aryl group or a substituted or unsubstituted heteroaryl group. NX is hydrogen, substituted or unsubstituted alkyl, or substituted or unsubstituted cycloalkyl, R CX and R IX are each independently hydrogen, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted alkyl, or substituted or unsubstituted cycloalkyl, and the two R CX Can bond to each other to form a ring, two R IX They can bond with each other to form a ring. NX , R CX and R IX can be connected to the R NX , the R CX , or the R IX One or two bonds to the ring to which X is bonded.

[0249] [Chemistry 18]

[0250]

[0251] The group represented by formula (X2) is bonded to ring A at one of the two wavy lines, and is bonded to ring B or ring C at the other wavy line. That is, the bonding position of the wavy line is equivalent to the bonding position of X to ring A, ring B or ring C in formula (1). Furthermore, the group represented by formula (X2) is bonded to ring A or ring B, or ring A or ring C to which the group is bonded at *. The position at which each ring of ring A, ring B and ring C is bonded to the * of the group represented by formula (X2) is a ring-constituting atom adjacent to the ring-constituting atom to which the group is bonded at the position of the wavy line. That is, when ring A, ring B or ring C to which the group represented by formula (X2) is bonded is a substituted or unsubstituted benzene ring, the polycyclic aromatic compound of the present invention becomes a polycyclic aromatic compound having L bonded to the meta position of Y. F structure.

[0252] In formula (X2), "F" is a symbol representing a ring structure represented by a circle, and the F ring is a substituted or unsubstituted aryl ring or a substituted or unsubstituted heteroaryl ring. The F ring forms a divalent group having bonding bonds on two atoms (preferably carbon) adjacent to each other on the aryl ring or heteroaryl ring in its structure. The F ring is bonded to nitrogen and L through the two bonding bonds. FBond. The F ring may also be bonded to another ring to which the base represented by the formula (X2) is bonded as described later to form a trivalent group. The ring in which the atoms having the two bonding bonds are set as the ring-constituting atoms in the F ring is preferably a 5-membered ring or a 6-membered ring. The ring may be further condensed with other rings. Examples of 6-membered rings include: benzene rings, pyridine rings, pyrazine rings, pyrimidine rings, etc. Examples of 6-membered rings that are further condensed with other rings include: naphthalene rings, quinoline rings, benzofuran rings, benzothiophene rings, indole rings, benzoselenophene rings, dibenzofuran rings, dibenzothiophene rings, carbazole rings, dibenzoselenophene rings, etc. Examples of 5-membered rings include: furan rings, thiophene rings, pyrrole rings, thiazole rings, selenophene rings, etc. Examples of 5-membered rings that are further condensed with other rings include: benzofuran rings, benzothiophene rings, indole rings, benzoselenophene rings, etc. In addition, as condensed rings, indene rings may also be mentioned. The aryl ring or heteroaryl ring in the F ring is preferably a benzene ring, a pyridine ring, a pyrazine ring, or a pyrimidine ring, and more preferably a benzene ring.

[0253] Ring F is a substituted or unsubstituted aryl ring or a substituted or unsubstituted heteroaryl ring. Here, as the substituent mentioned in "substituted or unsubstituted (substituted or unsubstituted)", it is preferably at least one substituent selected from the substituent group Zα. In addition, the substituent may also be a substituted or unsubstituted diarylphosphino group such as a diphenylphosphino group. When there are multiple substituents, the multiple substituents may be the same or different from each other.

[0254] As the substituent, an alkyl group, a cycloalkyl group, an aryl group which may be substituted by an alkyl group or a cycloalkyl group, or a heteroaryl group which may be substituted by an alkyl group or a cycloalkyl group is more preferred, and a tert-butyl group, an adamantyl group, or a phenyl group which may be substituted by a tert-butyl group or an adamantyl group is further preferred. The substitution position is preferably the position farthest from the nitrogen (the nitrogen directly bonded to the A ring) (e.g., the para position) or the position farthest from the L F The furthest position (for example, the para position) In addition, regarding the substituents, reference can be made to the description of "preferred substituents" described later.

[0255] The F ring is also preferably an unsubstituted aryl ring or an unsubstituted heteroaryl ring.

[0256] In addition, the F ring is also preferably a structure in which two groups respectively bonded to two adjacent carbon atoms on the aryl ring or heteroaryl ring in its structure are bonded to each other, and together with the two carbon atoms, form a cycloolefin ring. This structure is equivalent to a structure in which the aryl ring or heteroaryl ring is condensed by a cycloalkane as described later. Among them, it is particularly preferred that the two groups are bonded to each other to form a partial structure represented by the formula (B11) or formula (B12) described later.

[0257] The group represented by formula (X2) is bonded at * to the A ring or B ring or the A ring or C ring to which the group is bonded at the wavy line position.

[0258] In formula (X2), L F is a single bond, >NR NL 、>O、>S、>C(-R CL )2、>Si(-R IL )2 or>Se. R NL , R CL and R IL are each independently hydrogen, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted alkyl, or substituted or unsubstituted cycloalkyl, and the two R CL Can bond to each other to form a ring, two R IL can bond with each other to form a ring. NL , R CL and R IL Each of the rings A, B, and C may be independently bonded to at least one of the rings A, B, and C via a linking group or a single bond.

[0259] As L F , preferably a single bond, >NR NL , >O, >S or >Se, more preferably a single bond, >O or >S, further preferably a single bond or >S, and most preferably a single bond.

[0260] The F ring in the group represented by formula (X2) can be further bonded to the group L F2 It is bonded to another ring (a ring different from the ring bonded at *) to which the group represented by formula (X2) is bonded. F2 With L F have the same meaning and the preferred range is also the same. F2 With L F They may be the same or different. F2 With L F At least any one of is a single bond.

[0261] When the F ring in the group represented by formula (X2) is bonded to the group L F2 When the group represented by the formula (X2) is bonded to a ring different from the ring to which the group represented by the formula (X2) is bonded at *, the group represented by the formula (X2) can be represented by the following formula (X2-LF2).

[0262] [Chemistry 19]

[0263]

[0264] The group represented by the formula (X2-LF2) is bonded at two *s to the A ring and the B ring or the A ring and the C ring to which the group is bonded at the wavy line position.

[0265] The additional bonding position to the group represented by formula (X2) in each ring of ring A, ring B and ring C (the bonding position to the * in formula (X2-LF2)) can be a ring-constituting atom adjacent to the ring-constituting atom to which the group represented by formula (X2) is bonded at the position of the wavy line.

[0266] The number of groups represented by formula (X2) in the polycyclic aromatic compound of the present invention may be 0 to 3 in accordance with the number of structural units represented by formula (1) and the number of groups represented by formula (X1), formula (X3), or formula (X13), and the number is not particularly limited. When there are a plurality of groups represented by formula (X2), they may be the same or different from each other.

[0267] When other X other than the group represented by formula (X1), formula (X3), or formula (X13) is >N-Ar X When Ar X is a substituted or unsubstituted aryl group or a substituted or unsubstituted heteroaryl group, and preferred examples thereof include a substituted or unsubstituted phenyl group, a substituted or unsubstituted biphenyl group, or a substituted or unsubstituted triphenyl group. Examples of substituents in the substituted or unsubstituted phenyl group include a methyl group, a tert-butyl group, a 1-adamantyl group, and a substituent represented by the formula (A30).

[0268] When other X other than the group represented by formula (X1), formula (X3), or formula (X13) is >NR NX When R NX , preferably a substituted or unsubstituted cycloalkyl group. When other X other than the group represented by formula (X1), formula (X3), or formula (X13) is >C(-R CX )2, R CX Preferably, it is a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted heteroaryl group, and more preferably, it is a methyl group, or a phenyl group which may be substituted with a methyl group or a tert-butyl group. When X other than the group represented by formula (X1), formula (X3), or formula (X13) is >Si(-R IX )2, R IX Preferred is a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted heteroaryl group, and more preferred is a methyl group, or a phenyl group which may be substituted with a methyl group or a tert-butyl group.

[0269] R in X NX , R CX and R IX It may be bonded to one or two rings to which X itself is bonded, respectively, through a single bond or a linking group. Specifically, in formula (1), R in X NX , R CXand R IX The ring may be bonded to at least one of the A ring and the B ring or at least one of the A ring and the C ring via a single bond or a linking group.

[0270] As R NX , R CX and R IX Examples of the linking group when bonding to each ring include -CH2-CH2-, -CHR-CHR-, -CR2-CR2-, -CH=CH-, -CR=CR-, -C≡C-, -N(-R)-, -O-, -S-, -C(-R)2-, -C(=O)-, -C(=S)-, -S(=O)-, -S(=O)2-, -Se(=O)-, -Se(=O)2-, -P(=O)-, -B(-R)-, -Si(-R)2-, or -Se-. Among these, -CH=CH-, -CR=CR-, -N(-R)-, -O-, -S-, and -C(-R)2- are preferred, -CH=CH-, -CR=CR-, -N(-R)-, -O-, and -S- are more preferred, and -CR=CR-, -N(-R)-, -O-, and -S- are further preferred. The R of "-CHR-CHR-", the R of "-CR2-CR2-", the R of "-CR=CR-", the R of "-N(-R)-", the R of "-C(-R)2-", the R of "-B(-R)-", and the R of "-Si(-R)2-" are independently hydrogen, aryl which may be substituted by alkyl or cycloalkyl, heteroaryl which may be substituted by alkyl or cycloalkyl, alkyl which may be substituted by alkyl or cycloalkyl, alkenyl which may be substituted by alkyl or cycloalkyl, alkynyl which may be substituted by alkyl or cycloalkyl, or cycloalkyl which may be substituted by alkyl or cycloalkyl. In addition, two R bonded to the same atom may bond to each other to form a ring. Furthermore, two adjacent R may bond to each other to form a cycloalkylene ring, an arylene ring, and a heteroarylene ring. In addition, these rings may also be substituted by alkyl or cycloalkyl.

[0271] The following partial structure (A10) can also be formed by the connection as described above.

[0272] [Chemistry 20]

[0273]

[0274] In formula (A10), R A1 ~R A4 are independently hydrogen, alkyl or cycloalkyl, R A1 ~R A4Any two to four of may be bonded to each other via a linking group or a single bond, and may be bonded to one of the two rings bonded to X at the two * positions, and bonded to the other ring at the ** position. That is, N in formula (A10) is X>NR NX When>NR NX N. The atoms on the ring that are bonded at the two * positions only need to be adjacent atoms (preferably carbon atoms). The partial structure represented by formula (A10) includes a NC bond with a weak bond dissociation energy (BDE), but the presence of another bond that forms the ring also promotes the reverse reaction (rebonding reaction) when the NC bond breaks, thus becoming a more stable structure. Therefore, in an organic EL element manufactured using a polycyclic aromatic compound having such a structure, it can be expected that the element life will be extended. When the structure represented by formula (A10) is included in the polycyclic aromatic compound, the number thereof can be one or two (preferably one).

[0275] In formula (A10), R A1 ~R A4 Any two to four of may be linked to each other via a linking group or a single bond.

[0276] R A1 ~R A4 Preferably, any two (R A1 and R A4 , R A1 and R A4 and R A2 and R A3 , R A1 and R A2 , R A3 and R A4 , R A1 and R A2 and R A3 and R A4 ) are bonded to each other through a linking group or a single bond, and more preferably R A1 and R A4 They are bonded to each other through a linking group or a single bond. As a divalent group formed by mutual bonding, an alkylene group can be cited. At least one hydrogen in the alkylene group can be substituted by an alkyl group or a cycloalkyl group, and at least one (preferably one) -CH2- in the alkylene group can be substituted by -O- and -S-. As a divalent group formed by mutual bonding, a straight-chain alkylene group having 2 to 5 carbon atoms is preferred, a straight-chain alkylene group having 3 or 4 carbon atoms is more preferred, and a straight-chain alkylene group having 4 carbon atoms (-(CH2)4-) is further preferred. The straight-chain alkylene group having 4 carbon atoms (-(CH2)4-) is particularly preferably unsubstituted.

[0277] The remaining R that is not involved in the linkA1 ~R A4 Preferably, they are each independently hydrogen or an optionally substituted alkyl group, more preferably an optionally substituted alkyl group having 1 to 6 carbon atoms, further preferably an unsubstituted alkyl group having 1 to 6 carbon atoms, and most preferably, they are all methyl groups.

[0278] That is, the partial structure represented by formula (A10) is preferably a structure represented by the following formula (A11).

[0279] [Chemistry 21]

[0280]

[0281] In formula (A11), Me is a methyl group, and is bonded to one of the two rings bonded to X at the two * positions, and is bonded to the other ring at the ** position.

[0282] In the polycyclic aromatic compound containing the structural unit represented by formula (1) used as an emissive dopant in the light-emitting layer of an organic EL element, the other X is preferably a group represented by formula (X2), >N-Ar X 、>NR NX , >S, >O or >Se, more preferably a group represented by formula (X2) or >N-Ar X .

[0283] <Explanation of Y>

[0284] In formula (1), Y is >B-, >P-, >P(=O)-, >P(=S)-, >Al-, >Ga-, >As-, >Si(-R IY )-or>Ge(-R GY )-, R IY and R GY are each independently a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted alkyl, or a substituted or unsubstituted cycloalkyl. IY and R GY , particularly preferably an aryl group having 6 to 10 carbon atoms (e.g., phenyl, naphthyl, etc.), an alkyl group having 1 to 5 carbon atoms (e.g., methyl, ethyl, etc.), or a cycloalkyl group having 5 to 10 carbon atoms (preferably cyclohexyl or adamantyl).

[0285] Y is preferably >B-, >P(=O)- or >P(=S)-, and more preferably >B-.

[0286] <Structure composed of one or two or more structural units>

[0287] The polycyclic aromatic compound of the present invention is a polycyclic aromatic compound having a structure composed of one or two or more structural units represented by formula (1).

[0288] The polycyclic aromatic compound having a structure consisting of one of the above structural units is a polycyclic aromatic compound represented by the formula explained above as the structural unit represented by formula (1).

[0289] The polycyclic aromatic compound having a structure composed of two or more of the structural units is a compound equivalent to a polymer of the polycyclic aromatic compound represented by the formula described above as the structural unit represented by formula (1). The polymer is preferably a dimer to a hexamer, and more preferably a dimer to a trimer. The polymer may be in the form of a plurality of the structural units in one compound, and may be in the form of bonding in a manner that any ring (A ring, B ring, or C ring) contained in the structural unit is shared by a plurality of structural units, or in the form of bonding in a manner that any ring (A ring, B ring, or C ring) contained in the structural unit is condensed with each other. In addition, it may be in the form of bonding in a manner that any ring (A ring, B ring, or C ring) contained in the structural unit and X to which it is bonded are shared by a plurality of structural units. It may also be in the form of bonding in a manner that multiple structural units are bonded by a single bond, an alkylene group having 1 to 3 carbon atoms, a phenylene group, a naphthylene group, or the like. Among these, a form in which the bonds are bonded so as to share a ring is preferred.

[0290] The two or more structural units in the polycyclic aromatic compound having a structure composed of two or more structural units represented by formula (1) may be the same as or different from each other.

[0291] Examples of structures composed of two or three of the structural units bonded to each other in a shared ring are shown below.

[0292] [Chemistry 22]

[0293]

[0294] In formula (1M2-1), formula (1M2-2), formula (1M2-3), formula (1M2-4), formula (1M3-1), formula (1M3-2), formula (1M3-3), and formula (1M3-4),

[0295] Ring A, Ring B, Ring C, X and Y have the same meanings as Ring A, Ring B, Ring C, X and Y in Formula (1), and Ring A', Ring B' and Ring C' correspond to Ring A, Ring B and Ring C in Formula (1), respectively.

[0296] <Structure example>

[0297] As specific examples of the structure of the polycyclic aromatic compound of the present invention composed of one of the structural units represented by formula (1), there can be mentioned compounds represented by any of the following formulae.

[0298] [Chemistry 23]

[0299]

[0300] [Chemistry 24]

[0301]

[0302] In the above formulas, Y, X D , L D and R bz With Y, X in formula (1) D , L D and R bz They have the same meaning respectively. 0 X other than the group represented by the formula (X1), the formula (X3), or the formula (X13) in the formula (1), that is, a group represented by the formula (X2), >N-Ar X 、>NR NX 、>O、>C(-R CX )2、>Si(-R IX )2, >S or >Se. Z is independently -C(-R Z )=or-N=,R Z are independently hydrogen or a substituent, any two adjacent R Z They may be bonded to each other and to the benzene ring to which they are bonded to form a substituted or unsubstituted aryl ring or a substituted or unsubstituted heteroaryl ring.

[0303] In the above formulas, X 2 NR NZ 、>O、>C(-R CZ )2、>Si(-R IZ )2、>S or >Se, R NZ , R CZ and R IZ are each independently hydrogen, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted alkyl, or substituted or unsubstituted cycloalkyl, and the two R CZ Can bond to each other to form a ring, two R IZ They may bond with each other to form a ring. 2 NR NZ R NZ , preferably a substituted or unsubstituted aryl group or a substituted or unsubstituted heteroaryl group. 2 is>C(-RCZ )2 CZ Preferably, it is a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted heteroaryl group, and more preferably, it is a methyl group, or a phenyl group which may be substituted with a methyl group or a tert-butyl group. 2 >Si(-R IZ )2 IZ Preferred is a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted heteroaryl group, and more preferred is a methyl group, or a phenyl group which may be substituted with a methyl group or a tert-butyl group.

[0304] X 2 Preferably >O, >C(-R CZ )2、>Si(-R IZ )2. >S or >Se, more preferably >O or >S.

[0305] In addition, in the above formulas, 0 Any atom to which it is bonded may be adjacent to Z, which may be -C (-R Z )=, where R Z is a group represented by X (formula (X2), R NX etc. or with R NX The bonding bond of the linking group (such as the bonding group).

[0306] In each monocyclic ring of the above formulae, the number of Z as =N- is preferably 0 to 2, more preferably 0 to 1, and still more preferably 0. That is, Z is preferably all -C(-R Z )=.

[0307] As R Z When R is a substituent, the substituent is preferably at least one substituent selected from the substituent group Zα. In addition, the substituent may be a substituted or unsubstituted diarylphosphino group such as a diphenylphosphino group. Z When multiple substituents are used, they may be the same or different. As the substituent, preferably a substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, a substituted or unsubstituted diarylamino group, or a substituent represented by formula (A30), more preferably an alkyl group, a phenyl group which may be substituted by an alkyl group, or a substituted or unsubstituted cycloalkyl group, and particularly preferably a methyl group, a tert-butyl group, a 1-adamantyl group, or a cyclohexyl group. In addition, regarding the substituent, reference may be made to the description of <Preferred substituents> described below. R as a substituent Z The position of is preferably the para position of Y or nitrogen (X). Z Preferred is hydrogen.

[0308] As an example of a specific skeleton structure of the polycyclic aromatic compound of the present invention composed of two of the structural units represented by formula (1), there can be mentioned a compound represented by any of the following formulae.

[0309] [Chemistry 25]

[0310]

[0311] [Chemistry 26]

[0312]

[0313] [Chemistry 27]

[0314]

[0315] [Chemistry 28]

[0316]

[0317] [Chemistry 29]

[0318]

[0319] In the above formulas,

[0320] Y, X D , L D , L F , L F2 and R bz With Y, X in formula (1) D , L D , L F , L F2 and R bz have the same meanings and the same preferred ranges, Z and X 0 and Z and X in formula (1A-1) 0 They have the same meanings and the preferred ranges are also the same.

[0321] <Preferred substituents>

[0322] In the polycyclic aromatic compounds used as emissive dopants (and in the compounds used as dopants), as a substituent containing an "alkyl group", a tertiary alkyl group represented by the following formula (tR) is one of the particularly preferred groups. The reason is that by such a bulky substituent, the intermolecular distance increases, and thus the luminescence quantum yield (photoluminescence quantum yield (photoluminescence quantum yield, PLQY)) is improved. In addition, it is also preferred that the tertiary alkyl group represented by the formula (tR) is substituted as a second substituent on other substituents. Specifically, a diarylamino group substituted with a tertiary alkyl group represented by the formula (tR), a carbazolyl group substituted with a tertiary alkyl group represented by the formula (tR) (preferably an N-carbazolyl group), or a benzocarbazolyl group substituted with a tertiary alkyl group represented by the formula (tR) (preferably an N-benzocarbazolyl group) can be listed. Examples of substitution forms of the group of formula (tR) for the diarylamino group, carbazolyl group and benzocarbazolyl group include a case where a part or all of the hydrogen atoms of the aryl ring or benzene ring in these groups are substituted with the group of formula (tR).

[0323] [Chemistry 30]

[0324]

[0325] In the formula (tR), R a , R b and R c Each independently represents an alkyl group having 1 to 24 carbon atoms, wherein any -CH2- in the alkyl group may be substituted by -O-, and the group represented by the formula (tR) has * as a bonding position.

[0326] As R a , R b and R c The "alkyl group having 1 to 24 carbon atoms" may be any of a straight chain and 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).

[0327] R in the formula (tR) a , R b and R c The total number of carbon atoms in the moiety is preferably 3 to 20, particularly preferably 3 to 10.

[0328] As R a , R b , and R cSpecific examples of the alkyl group include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, isopentyl, neopentyl, tert-pentyl, n-hexyl, 1-methylpentyl, 4-methyl-2-pentyl, 3,3-dimethylbutyl, 2-ethylbutyl, n-heptyl, 1-methylhexyl, n-octyl, tert-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, and n-icosyl.

[0329] Examples of the group represented by the formula (tR) include a tert-butyl group, a tert-amyl group, a 1-ethyl-1-methylpropyl group, a 1,1-diethylpropyl group, a 1,1-dimethylbutyl group, a 1-ethyl-1-methylbutyl group, a 1,1,3,3-tetramethylbutyl group, a 1,1,4-trimethylpentyl group, a 1,1,2-trimethylpropyl group, a 1,1-dimethyloctyl group, a 1,1-dimethylpentyl group, a 1,1-dimethylheptyl group, a 1,1,5-trimethylhexyl group, 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, tert-butyl and tert-pentyl are preferred.

[0330] As the substituent, a substituent represented by formula (A30) is also preferred.

[0331] The emission wavelength can be adjusted by the steric hindrance, electron donating property, and electron withdrawing property of the structure of the substituent possessed by the compound used as a dopant (assisting dopant or emitting dopant). The group represented by the following structural formula is preferred, and a methyl group, a tert-butyl group, a tert-amyl group, a tert-octyl group, a neopentyl group, an adamantyl group, a phenyl group, an o-tolyl group, a p-tolyl group, a 2,4-xylyl group, a 2,5-xylyl group, a 2,6-xylyl group, a 2,4,6-mesityl group, a diphenylamino group, a di-p-tolylamino group, a bis(p-(tert-butyl)phenyl)amino group, a carbazolyl group, a 3,6-dimethylcarbazolyl group, a 3,6-di-tert-butylcarbazolyl group, and a phenoxy group are more preferred. A methyl group, a tert-butyl group, a tert-amyl group, a tert-octyl group, a neopentyl group, an adamantyl group, a phenyl group, an o-tolyl group, a 2,6-xylyl group, a 2,4,6-mesityl group, a diphenylamino group, a di-p-tolylamino group, a bis(p-(tert-butyl)phenyl)amino group, a carbazolyl group, a 3,6-dimethylcarbazolyl group, a 3,6-di-tert-butylcarbazolyl group, and a tribenzazepinyl group are further preferred. From the viewpoint of ease of synthesis, a group with large steric hindrance is preferred because selective synthesis can be performed. Specifically, a tert-butyl group, a tert-amyl group, a tert-octyl group, an adamantyl group, an o-tolyl group, a p-tolyl group, a 2,4-xylyl group, a 2,5-xylyl group, a 2,6-xylyl group, a 2,4,6-mesityl group, a di-p-tolylamino group, a bis(p-(tert-butyl)phenyl)amino group, a 3,6-dimethylcarbazolyl group, and a 3,6-di-tert-butylcarbazolyl group are preferred.

[0332] In the following structural formulas, * indicates a bonding position.

[0333] [Chemistry 31]

[0334]

[0335] [Chemistry 32]

[0336]

[0337] [Chemistry 33]

[0338]

[0339] [Chemistry 34]

[0340]

[0341] [Chemistry 35]

[0342]

[0343] [Chemistry 36]

[0344]

[0345] [Chemistry 37]

[0346]

[0347] [Chemistry 38]

[0348]

[0349] [Chemistry 39]

[0350]

[0351] [Chemistry 40]

[0352]

[0353] [Chemistry 41]

[0354]

[0355] [Chemistry 42]

[0356]

[0357] [Chemistry 43]

[0358]

[0359] [Chemistry 44]

[0360]

[0361] The polycyclic aromatic compound containing the structural unit represented by formula (1) is preferably a structure containing at least one tertiary alkyl (tert-butyl or tert-amyl, etc.), neopentyl or adamantyl represented by the formula (tR), and more preferably a tertiary alkyl (tert-butyl or tert-amyl, etc.) represented by the formula (tR). The reason is that by such a bulky substituent, the intermolecular distance increases, so the luminescence quantum yield (PLQY) is improved. In addition, as a substituent, it is also preferably a diarylamino group. Furthermore, a diarylamino group substituted by a base of formula (tR), a carbazolyl group substituted by a base of formula (tR) (preferably N-carbazolyl) or a benzocarbazolyl group substituted by a base of formula (tR) (preferably N-benzocarbazolyl) is also preferred. As a substitution form of the base of formula (tR) for diarylamino, carbazolyl and benzocarbazolyl, examples of hydrogen substitution of a part or all of the hydrogen of the aryl ring or benzene ring in these groups by the base of formula (tR) can be cited.

[0362] In the structure represented by formula (1), the substituent of the aryl ring or heteroaryl ring may be a substituent represented by the following formula (A20).

[0363] [Chemistry 45]

[0364]

[0365] The substituent represented by formula (A20) is bonded to two adjacent atoms on the aryl ring or heteroaryl ring at two * positions. In formula (A20), L is >NR, >O, >Si(-R)2 or >S, R of the >NR is a substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted alkyl or substituted or unsubstituted cycloalkyl, R of the >Si(-R)2 is hydrogen, a substitutable aryl, a substitutable alkyl or a substitutable cycloalkyl, and two Rs may be bonded to each other to form a ring, and at least one of the Rs of the >NR and the >Si(-R)2 may be bonded to the aryl ring or heteroaryl ring through a linking group or a single bond,

[0366] r is an integer from 1 to 4,

[0367] R A are independently hydrogen, substituted or unsubstituted alkyl or substituted or unsubstituted cycloalkyl, any R A Can be connected to any other R through a linking group or a single bond A Mutually bonded.

[0368] Examples of the substituent include substituents represented by any of the following.

[0369] [Chemistry 46]

[0370]

[0371] In each formula, the * only needs to be bonded to two or three consecutive (adjacent) atoms on any aryl ring or heteroaryl ring.

[0372] <Cycloalkane condensation>

[0373] At least one of the aryl rings and heteroaryl rings selected from the group consisting of the polycyclic aromatic compound containing the structural unit represented by formula (1) may be condensed with at least one cycloalkane. The same is true for the polycyclic aromatic compounds represented by the various formulas shown in the above <Structural Examples>, and the following description is also applicable to the polycyclic aromatic compounds represented by the various formulas shown in the above <Structural Examples>.

[0374] The cycloalkane may be a cycloalkane having 3 to 24 carbon atoms. At least one hydrogen in the cycloalkane may be substituted by an aryl group having 6 to 30 carbon atoms, a heteroaryl group having 2 to 30 carbon atoms, an alkyl group having 1 to 24 carbon atoms, or a cycloalkyl group having 3 to 24 carbon atoms, and at least one -CH2- in the cycloalkane may be substituted by -O-.

[0375] The cycloalkane is preferably a cycloalkane having 3 to 20 carbon atoms, wherein at least one hydrogen in the cycloalkane may be substituted by an aryl group having 6 to 16 carbon atoms, a heteroaryl group having 2 to 22 carbon atoms, an alkyl group having 1 to 12 carbon atoms, or a cycloalkyl group having 3 to 16 carbon atoms.

[0376] 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.

[0377] Specific examples of cycloalkanes include cyclopropane, cyclobutane, cyclopentane, cyclohexane, cycloheptane, cyclooctane, cyclononane, cyclodecane, norbornane (bicyclo[2.2.1]heptane), bicyclo[1.1.0]butane, bicyclo[1.1.1]pentane, bicyclo[2.1.0]pentane, bicyclo[2.1.1]hexane, bicyclo[3.1.0]hexane, bicyclo[2.2.2]octane, adamantane, diadamantane, decahydronaphthalene and decahydroazulene, and alkyl (especially methyl)-substituted, halogen (especially fluorine)-substituted and deuterium-substituted products thereof having 1 to 5 carbon atoms.

[0378] Among the examples, a structure having at least one substituent on the carbon at the α position of the cycloalkane (a carbon adjacent to the carbon at the condensation site in the cycloalkane condensed to an aryl ring or a heteroaryl ring) such as shown in the following structural formula is preferred, a structure having two substituents on the carbon at the α position is more preferred, and a structure having two substituents on both carbons at the α position is further preferred (having a total of four substituents). As the substituent, alkyl groups (especially methyl) having 1 to 5 carbon atoms, halogens (especially fluorine) and deuterium are listed. Particularly preferred is a structure in which a partial structure represented by the following formula (B11) or the following formula (B12) is bonded to adjacent carbon atoms in an aryl ring or a heteroaryl ring, and more preferred is a structure in which a partial structure represented by the following formula (B11) is bonded to adjacent carbon atoms in an aryl ring or a heteroaryl ring.

[0379] [Chemistry 47]

[0380]

[0381] In formula (B11) and formula (B12), * represents a bonding position.

[0382] The number of cycloalkanes condensed on one aryl ring or heteroaryl ring is preferably 1 to 3, more preferably 1 or 2, and even more preferably 1. For example, the following shows an example in which one or more cycloalkanes are condensed on a benzene ring (phenyl). * represents the bonding position, which can be any of the carbons that constitute the benzene ring and do not constitute the cycloalkane. The cycloalkanes condensed as in formula (Cy-1-4) and formula (Cy-2-4) can also be condensed with each other. This is true whether the condensed ring (base) is an aryl ring or heteroaryl ring other than the benzene ring (phenyl), or whether the condensed cycloalkane is a cycloalkane other than cyclopentane or cyclohexane.

[0383] [Chemistry 48]

[0384]

[0385] At least one -CH2- in the cycloalkane may be substituted with -O-. For example, the following shows an example in which one or more -CH2- in the cycloalkane condensed on a benzene ring (phenyl) is substituted with -O-. This is true whether the condensed ring (base) is an aryl ring or heteroaryl ring other than the benzene ring (phenyl), or whether the condensed cycloalkane is a cycloalkane other than cyclopentane or cyclohexane.

[0386] [Chemistry 49]

[0387]

[0388] The cycloalkane may be substituted with at least one substituent, and as the substituent, any substituent selected from the substituent group Z may be cited. Among these substituents, alkyl groups (e.g., alkyl groups having 1 to 6 carbon atoms) and cycloalkyl groups (e.g., cycloalkyl groups having 3 to 14 carbon atoms) are preferred. In addition, it is also preferred that any hydrogen group is substituted with a halogen (e.g., fluorine) or deuterium. In addition, when a cycloalkyl group is substituted, it may be a substitution form that forms a spiro ring structure. For example, the following shows an example in which a spiro ring structure is formed in a cycloalkane condensed on a benzene ring (phenyl). Regarding the * in each structural formula, in the case of a benzene ring, it refers to a benzene ring contained in the skeletal structure of the compound, and in the case of a phenyl group, it refers to a bond that is substituted in the skeletal structure of the compound.

[0389] [Chemistry 50]

[0390]

[0391] As the form of cycloalkane condensation, first, the form in which the aryl ring and heteroaryl ring in each of the A ring, the B ring, and the C ring of the polycyclic aromatic compound containing the structural unit represented by formula (1) are condensed with cycloalkane. In addition, the form in which the aryl ring and heteroaryl ring in the D ring in formula (X1) and the F ring in formula (X2) are condensed with cycloalkane can be mentioned.

[0392] As another embodiment of the cycloalkane condensation, a polycyclic aromatic compound containing a structural unit represented by formula (1) may be mentioned, for example, Ar X For aromatic groups condensed from cycloalkanes>N-Ar X , a diarylamino group condensed by a cycloalkane (condensed to its aryl portion), a carbazolyl group condensed by a cycloalkane (condensed to its benzene ring portion), or a benzocarbazolyl group condensed by a cycloalkane (condensed to its benzene ring portion).

[0393] In addition, by introducing a cycloalkane structure into a polycyclic aromatic compound containing a structural unit represented by formula (1), a further reduction in melting point or sublimation temperature can be expected. The situation means that in the sublimation purification which is almost indispensable as a purification method for organic devices such as organic EL elements requiring high purity, since the purification can be performed at a lower temperature, thermal decomposition of the material can be avoided. In addition, the situation is also the same for the vacuum evaporation process which is a powerful means for making organic devices such as organic EL elements. The process can be implemented at a lower temperature, so thermal decomposition of the material can be avoided, and high-performance organic devices can be obtained as a result. In addition, since the solubility in organic solvents is improved by introducing a cycloalkane structure, it can also be applied to the production of components using a coating process. Among them, the present invention is not particularly limited to these principles.

[0394] <Substitution with heavy stable isotopes>

[0395] Each element in the polycyclic aromatic compound containing the structural unit represented by formula (1) is an element containing multiple isotopes that occur naturally in a natural occurrence ratio unless otherwise specified. All or part of the elements in each structural formula may contain more than the natural occurrence ratio (for example, in the case of boron-11 ( 11 In the present specification, it is referred to as "replaced with" "heavy stable isotopes". More specifically, at least one hydrogen can be replaced with deuterium, and at least one nitrogen can be replaced with nitrogen-15 ( 15 N), at least one sulfur may be substituted with sulfur-33 ( 33 S), sulfur-34 ( 34 S) or sulfur-36( 36 S), at least one oxygen may be substituted with oxygen-17 ( 17 O) or oxygen-18 ( 18O), at least one carbon may be substituted with carbon-13 ( 13 C), at least one boron may be substituted with boron-11 ( 11 B). The same is true for the structures represented by the formulas shown in the above <Structure Examples>, and this description is also applicable to the polycyclic aromatic compounds represented by the formulas shown in the above <Structure Examples>. By replacing at least a portion of the elements with heavy stable isotopes, especially by replacing boron-11 ( 11 B) Substituting at least one boron can extend the life of an organic electroluminescent device using a polycyclic aromatic compound containing a structural unit represented by formula (1) as a dopant.

[0396] <Substitution using deuterium>

[0397] All or part of the hydrogen atoms in the polycyclic aromatic compound containing the structural unit represented by formula (1) may be deuterium. The same is true for the polycyclic aromatic compounds represented by the formulas shown in the above <Structural Examples>, and the following description is also applicable to the polycyclic aromatic compounds represented by the formulas shown in the above <Structural Examples>.

[0398] For example, hydrogen in the aryl ring or heteroaryl ring in the A ring, B ring, and C ring of formula (1) or in a substituent thereof may be substituted with deuterium, and examples thereof include a form in which all or part of the hydrogen in the aryl or heteroaryl group is substituted with deuterium. In addition, from the viewpoint of durability, it is also preferred that all or part of the hydrogen in the polycyclic aromatic compound containing the structural unit represented by formula (1) is deuterated.

[0399] <Specific examples of polycyclic aromatic compounds>

[0400] Specific examples of the polycyclic aromatic compound of the present invention include compounds represented by any of the following structural formulae: However, the polycyclic aromatic compound having a structure composed of one or two or more structural units represented by formula (1) is not limited to the following specific examples.

[0401] [Chemistry 51]

[0402]

[0403] [Chemistry 52]

[0404]

[0405] [Chemistry 53]

[0406]

[0407] [Chemistry 54]

[0408]

[0409] [Chemistry 55]

[0410]

[0411] [Chemistry 56]

[0412]

[0413] [Chemistry 57]

[0414]

[0415] [Chemistry 58]

[0416]

[0417] [Chemistry 59]

[0418]

[0419] [Chemistry 60]

[0420]

[0421] [Chemistry 61]

[0422]

[0423] [Chemistry 62]

[0424]

[0425] [Chemistry 63]

[0426]

[0427] [Chemistry 64]

[0428]

[0429] [Chemistry 65]

[0430]

[0431] [Chemistry 66]

[0432]

[0433] [Chemistry 67]

[0434]

[0435] [Chemistry 68]

[0436]

[0437] [Chemistry 69]

[0438]

[0439] [Chemistry 70]

[0440]

[0441] <Explanation of increasing the molecular weight of polycyclic aromatic compounds>

[0442] The polycyclic aromatic compound containing the structural unit represented by formula (1) can also be used as the following polymer compound (the monomer used to obtain the polymer compound has a polymerizable substituent), or the polymer crosslinked body (the polymer compound used to obtain the polymer crosslinked body has a crosslinkable substituent), or the following pendant polymer compound (the reactive compound used to obtain the pendant polymer compound has a reactive substituent), or the pendant polymer crosslinked body (the pendant polymer compound used to obtain the pendant polymer crosslinked body has a crosslinkable substituent) for use in materials for organic devices. , for example, materials for organic electroluminescent elements, materials for organic field-effect transistors, materials for organic thin-film solar cells, or wavelength conversion filters, wherein the polymer compound is obtained by polymerizing the reactive compound having a reactive substituent substituted in a polycyclic aromatic compound containing a structural unit represented by formula (1) as a monomer, the polymer crosslinked body is obtained by further crosslinking the polymer compound, the pendant polymer compound is obtained by reacting a main chain polymer with the reactive compound, and the pendant polymer crosslinked body is obtained by further crosslinking the pendant polymer compound.

[0443] In this specification, the term "polymer compound" refers to a polymer having a molecular weight distribution and a polystyrene-equivalent number average molecular weight of 1×10 3 ~1×10 8 (1×10^3~1×10^8) polymers. The number average molecular weight (Mn) of the polymer compound in terms of polystyrene can be determined by size exclusion chromatography (SEC) using tetrahydrofuran in 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 SEC. The flow rate of the mobile phase is 1.0 mL / min, and PLgelMIXED_B (manufactured by Polymer Laboratories) is used as the column. The detector can use a UV_VIS detector (manufactured by Tosoh, trade name: UV-8320GPC).

[0444] The number average molecular weight of the polymer compound of the present invention is preferably 2000 to 1×10 8 , more preferably 5000 to 1×10 8 .

[0445] The reactive substituent (including the polymerizable substituent, the cross-linkable substituent, and the reactive substituent for obtaining the pendant type polymer, hereinafter also referred to as "reactive substituent") is not particularly limited as long as it is a substituent that can make the polycyclic aromatic compound high molecular weight, a substituent that can further cross-link the polymer compound obtained in this way, and a substituent that can undergo a pendant reaction in the main chain type polymer, but preferably a substituent of the following structure. * in each structural formula represents a bonding position.

[0446] [Chemistry 71]

[0447]

[0448] L is independently a single bond, -O-, -S-, >C=O, -OC(=O)-, an alkylene group having 1 to 12 carbon atoms, an oxyalkylene group having 1 to 12 carbon atoms, and a polyoxyalkylene group having 1 to 12 carbon atoms. Among the substituents, a group represented by formula (XLS-1), formula (XLS-2), formula (XLS-3), formula (XLS-9), formula (XLS-10), or formula (XLS-17) is preferred, and a group represented by formula (XLS-1), formula (XLS-3), or formula (XLS-17) is more preferred.

[0449] Such polymer compound, polymer crosslinked body, pendant polymer compound and pendant polymer crosslinked body may contain, in addition to the repeating unit of the polycyclic aromatic compound represented by formula (1), at least one selected from the group consisting of substituted or unsubstituted triarylamine, substituted or unsubstituted fluorene, substituted or unsubstituted anthracene, substituted or unsubstituted tetracene, substituted or unsubstituted triazine, substituted or unsubstituted carbazole, substituted or unsubstituted tetraphenylsilane, substituted or unsubstituted spirofluorene, substituted or unsubstituted triphenylphosphine, substituted or unsubstituted dibenzothiophene and substituted or unsubstituted dibenzofuran as a repeating unit.

[0450] Examples of substituents in these repeating units include aryl, heteroaryl, diarylamino, diheteroarylamino, arylheteroarylamino, diarylboryl (two aryl groups may be bonded via a single bond or a linking group), alkyl, cycloalkyl, alkoxy, aryloxy, triarylsilyl, trialkylsilyl, tricycloalkylsilyl, dialkylcycloalkylsilyl, or alkyldicycloalkylsilyl. For details of the "aryl" of the triarylamine or these substituents, the description of the polycyclic aromatic compound containing the structural unit represented by formula (1) can be cited.

[0451] The details of the uses of such polymer compounds, polymer crosslinked bodies, pendant polymer compounds and pendant polymer crosslinked bodies (hereinafter also referred to as "polymer compounds and polymer crosslinked bodies") will be described later.

[0452] <Method for producing polycyclic aromatic compounds>

[0453] The polycyclic aromatic compound containing the structural unit represented by formula (1) can be synthesized by applying the method disclosed in International Publication No. 2015 / 102118 and Japanese Patent Laid-Open No. 2021-95341. D The following description will be given by taking a compound having a C═O group as an example.

[0454] First, an intermediate (1-Hal) obtained by Goldberg reaction, Buchwald reaction, etc. is reacted with an alkyl lithium such as t-BuLi, and then a boron halide reagent such as boron tribromide is reacted, and then a base such as diisopropylethylamine is used to perform a tandem bora-Friedel-Crafts reaction to obtain intermediate 1 (first reaction). Next, a substituent R is used to react with a alkyl lithium such as t-BuLi, and then a alkyl lithium such as t-BuLi is used to react with a bora-Friedel-Crafts reaction to obtain intermediate 1 (first reaction). bZ The organic lithium reagent adjusted with alkyl lithium such as n-BuLi or the substituent R bZ The halide of the present invention reacts with an organomagnesium reagent or other organometallic reagent adjusted with metallic magnesium to obtain intermediate 2 (second reaction). Then, in the presence of a catalyst such as palladium hydroxide, the benzyl group is deprotected by reacting hydrogen, and then intermediate 3 is obtained by amination reaction (Goldenberg reaction, Buchwald reaction, etc.) of the halogenated carboxylic acid (a) (third reaction). Furthermore, intermediate 3 is converted into an acyl chloride using thionyl chloride or the like according to a conventional method, and then a Friedel-Crafts acylation reaction is carried out in the presence of a Lewis acid to obtain the compound of the target formula (1) (fourth reaction).

[0455] [Chemistry 72]

[0456]

[0457] In the first reaction, a Lewis acid such as aluminum chloride or iron (III) chloride may be added.

[0458] Examples of the chlorinating agent used in the fourth reaction include thionyl chloride, phosphorus trichloride, phosphorus pentachloride, sulfuryl chloride, and oxalyl chloride. Examples of the Lewis acid used include aluminum chloride and iron (III) chloride.

[0459] In the fourth reaction, the target product may be obtained by directly causing Friedel-Crafts acylation reaction by allowing sulfuric acid, polyphosphoric acid or the like to act without chlorination.

[0460] By appropriately selecting the raw materials to be used, a polycyclic aromatic compound having a substituent at a desired position can be synthesized.

[0461] In addition, the polycyclic aromatic compounds of the present invention also include compounds in which at least a portion of hydrogen atoms are substituted by deuterium or compounds in which halogens such as fluorine or chlorine are substituted. Such compounds can be synthesized in the same manner as described above by using raw materials in which the required positions are deuterated, fluorinated or chlorinated.

[0462] 2. Organic devices

[0463] The polycyclic aromatic compound of the present invention can be used as a material for organic devices. Examples of organic devices include organic electroluminescent elements, organic field effect transistors, and organic thin-film solar cells. The polycyclic aromatic compound of the present invention is preferably used as a material for forming any one or more organic layers in an organic electroluminescent element.

[0464] 2-1. Organic electroluminescent element

[0465] 2-1-1. Structure of organic electroluminescent element

[0466] Figure 1 This is a schematic cross-sectional view showing an example of an organic EL element.

[0467] Figure 1 The organic EL element 100 shown includes: a substrate 101, an anode 102 arranged on the substrate 101, a hole injection layer 103 arranged on the anode 102, a hole transport layer 104 arranged on the hole injection layer 103, a light-emitting layer 105 arranged on the hole transport layer 104, an electron transport layer 106 arranged on the light-emitting layer 105, an electron injection layer 107 arranged on the electron transport layer 106, and a cathode 108 arranged on the electron injection layer 107.

[0468] In addition, the organic EL element 100 can also reverse the production order to form a structure such as the following, which includes: a substrate 101, a cathode 108 disposed on the substrate 101, an electron injection layer 107 disposed on the cathode 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 an anode 102 disposed on the hole injection layer 103.

[0469] The above-mentioned layers are not all indispensable layers, and the minimum structural unit is set to a structure including an anode 102, a light-emitting layer 105, and a cathode 108. The hole injection layer 103, the hole transport layer 104, the electron transport layer 106, and the electron injection layer 107 are layers that can be set arbitrarily. In addition, the above-mentioned layers may each include a single layer or a plurality of layers.

[0470] The morphology of the layers constituting the organic EL element may be, in addition to the structural morphology of “substrate / anode / hole injection layer / hole transport layer / luminescent layer / electron transport layer / electron injection layer / cathode”, “substrate / anode / hole injection layer / luminescent layer / electron transport layer / electron injection layer / cathode”, “substrate / anode / hole injection layer / luminescent layer / electron transport layer / electron injection layer / cathode”, “substrate / anode / hole injection layer / hole transport layer / luminescent layer / electron injection layer / cathode”, “substrate / anode / hole injection layer / hole transport layer / luminescent layer / electron injection layer / cathode”, “substrate / anode / hole injection layer / hole transport layer / luminescent layer / electron injection layer / cathode”. The structural morphology of the substrate / anode / light-emitting layer / electron transport layer / electron injection layer / cathode", "substrate / anode / hole transport layer / light-emitting layer / electron injection layer / cathode", "substrate / anode / hole transport layer / light-emitting layer / electron injection layer / cathode", "substrate / anode / hole injection layer / light-emitting layer / electron transport layer / cathode", "substrate / anode / hole injection layer / light-emitting layer / electron injection layer / cathode", "substrate / anode / hole injection layer / light-emitting layer / electron transport layer / cathode", "substrate / anode / light-emitting layer / electron transport layer / cathode", and "substrate / anode / light-emitting layer / electron injection layer / cathode".

[0471] The organic EL element may further have any one or both selected from an electron blocking layer (electron blocking layer) and a hole blocking layer (hole blocking layer). The electron blocking layer has a LUMO that is shallower than the light-emitting layer and a HOMO that is close to the light-emitting layer or the hole transport layer, and is arranged between the light-emitting layer and the hole transport layer. Since the electrons are retained in the light-emitting layer and do not leak out to the hole transport layer, the shortening of the life caused by the degradation of the hole transport layer and the reduction in efficiency caused by the reduction in recombination efficiency can be prevented. The hole blocking layer has a HOMO that is deeper than the light-emitting layer and a LUMO that is close to the light-emitting layer or the hole transport layer, and is arranged between the light-emitting layer and the electron transport layer. Since the holes are retained in the light-emitting layer and do not leak out to the electron transport layer, the shortening of the life caused by the degradation of the electron transport layer and the reduction in efficiency caused by the reduction in recombination efficiency can be prevented. The hole injection / transport layer may also serve as an electron blocking layer. The electron injection / transport layer may also serve as a hole blocking layer.

[0472] The organic EL element may further have a high T1 layer. The high T1 layer has a higher T1 than the main compound, auxiliary dopant compound or emission dopant compound used in the light-emitting layer, and is arranged between the light-emitting layer and the hole transport layer and / or between the light-emitting layer and the electron blocking layer. The value of T1 energy varies depending on the light-emitting mechanism of the element, but has a higher T1 than the compound used in the main body. By having a high T1 layer around the light-emitting layer, triplet energy can be enclosed, and the triplet energy that is usually unrelated to light emission in the fluorescent molecules can be converted into singlet energy, thereby obtaining high efficiency. The hole injection / transport layer or the electron blocking layer can also serve as the high T1 layer. The electron injection / transport layer or the hole blocking layer can also serve as the high T1 layer.

[0473] 2-1-2. Substrate in organic electroluminescent element

[0474] The substrate 101 is a support of the organic EL element 100, and quartz, glass, metal, plastic, etc. can be generally used. The substrate 101 is formed into a plate, film or sheet according to the purpose, for example, a glass plate, a metal plate, a metal foil, a plastic film, a plastic sheet, etc. can be used. Among them, glass plates and transparent synthetic resin plates such as polyester, polymethacrylate, polycarbonate, polysulfone, etc. are preferably used. If it is a glass substrate, soda-lime glass or alkali-free glass, etc. can be used. In addition, the thickness can be sufficient to maintain the mechanical strength. In addition, in order to improve the gas barrier property, a gas barrier film such as a fine silicon oxide film can also be provided on at least one side of the substrate 101. When a plate, film or sheet made of a synthetic resin with low gas barrier property is used as the substrate 101, it is particularly preferred to provide a gas barrier film.

[0475] 2-1-3. Anode in organic electroluminescent element

[0476] The anode 102 plays a role of injecting holes into the light-emitting layer 105. When at least one of the hole injection layer 103 and the hole transport layer 104 is provided between the anode 102 and the light-emitting layer 105, holes are injected into the light-emitting layer 105 through these layers.

[0477] As materials for forming the anode 102, inorganic compounds and organic compounds can be cited. As inorganic compounds, for example, metals (aluminum, gold, silver, nickel, palladium, chromium, etc.), metal oxides (indium oxide, tin oxide, indium-tin oxide (Indium Tin Oxide, ITO), indium-zinc oxide (Indium Zinc Oxide, IZO), etc.), metal halides (copper iodide, etc.), copper sulfide, carbon black, ITO glass or Nesa glass, etc. As organic compounds, for example, polythiophenes such as poly(3-methylthiophene), conductive polymers such as polypyrrole and polyaniline, etc. can be cited. In addition, it can be appropriately selected from the substances used as the anode of the organic EL element for use.

[0478] 2-1-4. Hole injection layer and hole transport layer in organic electroluminescent element

[0479] The hole injection layer 103 plays a role of efficiently injecting holes migrated from the anode 102 into the light-emitting layer 105 or the hole transport layer 104. The hole transport layer 104 plays a role of efficiently transporting holes injected from the anode 102 or holes injected from the anode 102 via the hole injection layer 103 to the light-emitting layer 105. The hole injection layer 103 and the hole transport layer 104 are formed by stacking or mixing one or more hole injection / transport materials. In addition, an inorganic salt such as iron (III) chloride can be added to the hole injection / transport material to form a layer.

[0480] As a hole injection / transport material, it is necessary to efficiently inject / transmit holes from the positive electrode between electrodes to which an electric field is applied, and it is ideal that the hole injection efficiency is high and the injected holes are efficiently transmitted. Therefore, it is preferred that the material has a small ionization potential, a large hole mobility, and excellent stability, and is not prone to produce impurities that become traps during manufacture and use.

[0481] As materials for forming the hole injection layer 103 and the hole transport layer 104, any compound can be selected from compounds conventionally used as charge transport materials for holes in photoconductive materials, and known compounds used in hole injection layers and hole transport layers of p-type semiconductors and organic EL elements. 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-carbazole-3-yl)-[1,1'-biphenyl]-4,4'-diamine, N 4 ,N 4 ,N 4 ',N 4 '-tetrakis[1,1'-biphenyl]-4-yl-[1,1'-biphenyl]-4,4'-diamine, 4,4',4"-tris(3-methylphenyl(phenyl)amino)triphenylamine and other triphenylamine derivatives, starburst amine derivatives, etc.), stilbene derivatives, phthalocyanine derivatives (metal-free, copper phthalocyanine, etc.), pyrazoline derivatives, hydrazone compounds, benzofuran derivatives or 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. Among polymer systems, polycarbonate or styrene derivatives, polyvinylcarbazole and polysilane having the above monomers on the side chain are preferred, but there is no particular limitation as long as it is a compound that can form a thin film required for the production of a light-emitting element and can inject holes from the anode and then transport holes.

[0482] In addition, it is also known that the conductivity of organic semiconductors is strongly affected by their doping. Such organic semiconductor matrix materials contain compounds with good electron donating properties or compounds with good electron accepting properties. In order to dope electron donating materials, strong electron acceptors such as tetracyanoquinonedimethane (TCNQ) or 2,3,5,6-tetrafluorotetracyano-1,4-benzoquinonedimethane (F4TCNQ) are known (for example, refer to the literature "M. Pfeiffer, A. Bayer, T. Fritz, K. Leo (M. Pfeiffer , A. Beyer, T. Fritz, K. Leo), "Applied Physics Letters (Appl. Phys. Lett.)", 73(22), 3202-3204 (1998)" and the reference "J. Blochwitz, M. Pfeiffer, T. Fritz, K. Leo (J. Blochwitz, M. Pfeiffer, T. Fritz, K. Leo), "Applied Physics Letters (Appl. Phys. Lett.)", 73(6), 729-731 (1998)"). These so-called holes are generated through the electron migration process of the electron-donating basic material (hole transport material). The conductivity of the basic material varies greatly depending on the number and mobility of the holes. As a host material having hole transport properties, for example, benzidine derivatives (N,N'-bis(3-methylphenyl)-N,N'-bis(phenyl)benzidine (N,N'-bis(3-methylphenyl)-N,N'-bis(phenyl)benzidine, TPD), starburst amine derivatives (4,4',4"-tris(N,N-diphenylamino)triphenylamine (4,4',4"-tris(N,N-diphenylamino)triphenylamine, TDATA), or specific metal phthalocyanines (especially zinc phthalocyanine (ZnPc), etc.) are known (Japanese Patent Publication No. 2005-167175).

[0483] The hole injection layer material and the hole transport layer material can also be used in the hole layer material as the following polymer compound or its polymer cross-linked product, or the following pendant polymer compound or its pendant polymer cross-linked product, wherein the polymer compound is obtained by polymerizing a reactive compound substituted with a reactive substituent in the hole injection layer material and the hole transport layer material as a monomer, and the pendant polymer compound is obtained by reacting a main chain polymer with the reactive compound.

[0484] 2-1-5. Light-emitting layer in organic electroluminescent element

[0485] The polycyclic aromatic compound of the present invention is preferably used as a material for forming one or more organic layers in an organic electroluminescent device, and is more preferably used as a material for forming a light-emitting layer.

[0486] The light-emitting layer 105 is a layer that emits light by allowing holes injected from the anode 102 to recombine with electrons injected from the cathode 108 between electrodes to which an electric field is applied. The material forming the light-emitting layer 105 may be any compound (luminescent compound) that emits light by being excited by the recombination of holes and electrons, and preferably a compound that can form a stable thin film shape and exhibits strong luminescence (fluorescence) efficiency in a solid state.

[0487] The light-emitting layer may be a single layer or may include multiple layers, either of which is acceptable, and is formed of materials for the light-emitting layer (host material, dopant material). The host material and the dopant material may be one type or a combination of multiple types, either of which is acceptable. The dopant material may be contained in the entire host material or in part of the host material, either of which is acceptable. As a doping method, it can be formed by co-evaporation with the host material, or it can be pre-mixed with the host material and evaporated simultaneously.

[0488] The amount of the host material used varies depending on the type of the host material, and can be determined by matching the characteristics of the host material. The basis for the amount of the host material used is preferably 50% to 99.999% by mass of the total mass of the light-emitting layer material, more preferably 80% to 99.95% by mass, and further preferably 90% to 99.9% by mass. In the case where the host material is a combination of a hole-transporting host material and an electron-transporting host material, the amount of the host material used is the mass of the hole-transporting host material added to the amount of the electron-transporting host material. The ratio of the amount of the hole-transporting host material to the amount of the electron-transporting host material used can be 1:9 to 9:1 in terms of mass ratio, preferably 4:6 to 6:4, and more preferably approximately 1:1.

[0489] The amount of the dopant material used varies depending on the type of the dopant material, and can be determined by matching the characteristics of the dopant material. The basis for the amount of the dopant material used is preferably 0.001% to 50% by mass of the total mass of the material for the light-emitting layer, more preferably 0.05% to 20% by mass, and further preferably 0.1% to 10% by mass. If it is within the above range, it is preferred, for example, in terms of preventing concentration quenching.

[0490] As dopant materials, emitting dopant materials and auxiliary dopant materials can also be used. As auxiliary dopant materials, any one of thermally active delayed fluorescence materials and phosphorescent materials can be preferably used. In an organic electroluminescent element using an auxiliary dopant material, from the perspective of preventing concentration quenching, it is preferred that the amount of emitting dopant material used is low. From the perspective of the efficiency of the thermally active delayed fluorescence mechanism, it is preferred that the amount of auxiliary dopant material used is high. Furthermore, in an organic electroluminescent element using a thermally active delayed fluorescence auxiliary dopant material, from the perspective of the efficiency of the thermally active delayed fluorescence mechanism of the auxiliary dopant material, it is preferred that the amount of emitting dopant material used is low compared to the amount of auxiliary dopant material used.

[0491] When using auxiliary dopant materials, the base usage amounts of the main material, auxiliary dopant material and emission dopant material are 40% to 99% by mass, 59% to 1% by mass and 20% to 0.001% by mass, respectively, relative to the total mass of the materials 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.

[0492] The polycyclic aromatic compound of the present invention is more preferably used as a material for forming a light-emitting layer, and particularly more preferably used as a dopant.

[0493] The polycyclic aromatic compound including the structural unit represented by the formula (1) can be used as an emitting dopant for a TTF device utilizing a phenomenon in which a singlet exciton is generated from a plurality of triplet excitons (Triplet-Triplet Fusion (TTF)).

[0494] In addition, the polycyclic aromatic compound of the present invention can be used as a "thermally active delayed phosphor" and as an emitting dopant for an organic EL element (hereinafter sometimes referred to as a "TADF element") that exhibits thermally active delayed fluorescence (TADF). In a "thermally active delayed phosphor", by reducing the energy difference between the lowest excited singlet state and the lowest excited triplet state, the reverse intersystem crossing transition from the lowest excited triplet state to the lowest excited singlet state, which usually has a low transition probability, is efficiently generated, thereby showing light emission from the singlet state (thermally active delayed fluorescence, TADF). In normal fluorescent light emission, 75% of the triplet excitons generated by current excitation pass through the thermal deactivation path and therefore cannot be extracted as fluorescence. On the other hand, in TADF, all excitons can be used for fluorescent light emission, and a highly efficient organic EL element can be realized.

[0495] The polycyclic aromatic compound of the present invention can be used as an emitting dopant for a "TADF element", an emitting dopant for an element of TADF using two main bodies, an emitting dopant for an organic electroluminescent element (TAF element) using other thermally active delayed phosphors as auxiliary dopants, and an emitting dopant for an organic electroluminescent element (phosphorescent auxiliary element) using a phosphorescent material as an auxiliary dopant. From the viewpoint that the fewer materials used for the element, the easier it is to manufacture, it is preferably used as an emitting dopant for a TADF element or an emitting dopant for an element of TADF using two main bodies, and the former is more preferred. From the viewpoint of efficiency, it is preferably used as an emitting dopant for a TAF element and an emitting dopant for a phosphorescent auxiliary element, and it is more preferred to use it as an emitting dopant for a TAF element.

[0496] It is generally believed that the case of fast delayed fluorescence has excellent TADF properties. Specifically, when a light-emitting material with a delayed fluorescence lifetime of less than 20 μsec is used as an emission dopant in a light-emitting element, high element efficiency and long element lifetime can be provided. The delayed fluorescence lifetime is preferably less than 20 μsec, more preferably less than 10 μsec, and most preferably less than 5 μsec.

[0497] In addition, generally speaking, ΔE S1T1 The smaller the value of, the better the TADF property. S1T1 is the lowest excited singlet energy level (E S1 ) and the lowest excited triplet energy level (E T1 ) energy difference. Specifically, ΔE S1T1 The value of is preferably 0.20 eV or less, more preferably 0.15 eV or less, and particularly preferably 0.10 eV or less.

[0498] <Main material>

[0499] Examples of the host material include condensed ring derivatives of anthracene or pyrene, which have been known as luminescent materials in the past, bistyryl derivatives such as bistyryl anthracene derivatives and distyryl benzene derivatives, tetraphenylbutadiene derivatives, cyclopentadiene derivatives, fluorene derivatives, benzofluorene derivatives, N-phenylcarbazole derivatives, carbazole nitrile derivatives, dibenzo[pi] Derivatives, etc. In addition, from the viewpoint of durability, it is also preferred that part or all of the hydrogen atoms of the host material are deuterated. Furthermore, it is also preferred that a host compound in which part or all of the hydrogen atoms are deuterated is combined with a dopant compound in which part or all of the hydrogen atoms are deuterated to form a light-emitting layer.

[0500] From the viewpoint of promoting rather than inhibiting the generation of TADF in the light-emitting layer, the lowest excited triplet energy level (E T1) is higher than the highest E T1 E of dopant or auxiliary dopant T1 Specifically, the E of the main material T1 Preferably, the E of the dopant or auxiliary dopant is T1 It is higher by 0.01 eV or more, more preferably higher by 0.03 eV or more, and even more preferably higher by 0.1 eV or more. T1 It is preferably 2.70 eV or more, more preferably 2.73 eV or more, and further preferably 2.80 eV or more.

[0501] TADF-active compounds can also be used in the host material.

[0502] The host material may be one kind or a combination of two or more kinds. In the case of a combination of two or more kinds, a combination of a hole-transporting host material and an electron-transporting host material is preferred.

[0503] The hole transporting host material (HH) and the electron transporting host material (EH) satisfy the following relationship with respect to the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO).

[0504] The HOMO of the hole-transporting host material (HH) is shallower than the HOMO of the electron-transporting host material (EH), and the LUMO of the electron-transporting host material (EH) is deeper than the LUMO of the hole-transporting host material (HH).

[0505] In addition, it is preferred that the HOMO of the emissive dopant is shallower than the HOMO of the hole-transporting host material (HH), or the LUMO of the emissive dopant is deeper than the LUMO of the electron-transporting host material (EH).

[0506] In addition, from the viewpoint of promoting rather than inhibiting the generation of TADF in the light-emitting layer, the lowest excited triplet level (E T1 ) is higher than the highest E T1 E of the emission dopant or auxiliary dopant T1 Specifically, the E of the main material T1 Preferably, the E of the emitting dopant or the auxiliary dopant is T1 It is higher by 0.01 eV or more, more preferably higher by 0.03 eV or more, and even more preferably higher by 0.1 eV or more. T1It is preferably 2.47 eV or more, more preferably 2.49 eV or more, and further preferably 2.56 eV or more.

[0507] In addition, it is also preferred to use a hole transporting host material in the hole transport layer adjacent to the light-emitting layer, and to use an electron transporting host material in the electron transport layer adjacent to the light-emitting layer. This is because it is not easy to cause carrier leakage and energy leakage from the light-emitting layer to the adjacent layer, and a high-efficiency organic EL element can be obtained. The host material (hole transporting host material) in the light-emitting layer may be the same as or different from the hole transport layer material. In addition, the host material (electron transporting host material) in the light-emitting layer may be the same as or different from the material of the electron transport layer.

[0508] [Hole transport host material (HH)]

[0509] Examples of preferred hole transport host materials (HH) include compounds represented by formula (HH-1), or compounds having a partial structure represented by formula (HH-1) and having a structure containing at least three rings selected from the group consisting of an aryl ring and a heteroaryl ring. The compounds preferably do not contain an imine structure (-N=C-; partial structure containing a heteroaryl ring), boron (>B-), and a cyano group (CN).

[0510] [Chemistry 73]

[0511]

[0512] In formula (HH-1),

[0513] Q is >O, >S, or >NA H ,

[0514] One carbon atom adjacent to the carbon atom bonded to Q in each of the two phenyl groups in formula (HH-1) may be bonded to each other via L.

[0515] L is a single bond, >O, >S, or >C(-A H )2,

[0516] A H is hydrogen, aryl, or heteroaryl, and >C(-A H ) The two A's in 2 H Can bond to each other.

[0517] When the hole transport host material includes the structure represented by formula (HH-1) as a partial structure, it may include one of the partial structures, but it is also preferred to include two or more. In the case of including two or more, the two or more partial structures may be the same or different from each other. The two or more partial structures may be bonded to each other through a single bond, or they may be bonded in a manner that any ring contained in the partial structure is shared, or they may be bonded in a manner that any ring contained in the partial structure is condensed with each other. The partial structure may further have a substituent selected from an aryl group, a heteroaryl group, a diarylamino group, or an aryloxy group.

[0518] The compound represented by the formula (HH-1) or the compound having the partial structure represented by the formula (HH-1) has a structure containing at least three rings selected from the group consisting of aryl rings and heteroaryl rings. The number of rings contained is preferably 6 or more, more preferably 8 or more. In addition, it is preferably 20 or less, more preferably 15 or less, and further preferably 10 or less. The number of rings refers to the number of single rings, and with respect to condensed rings, it is the number obtained by counting the single rings constituting the condensed rings.

[0519] The hole transport host material is preferably a compound comprising one or more partial structures selected from the group consisting of a triarylamine structure, a carbazole ring, a dibenzofuran ring, a dibenzothiophene ring, and a condensed polycyclic ring containing phenoxazine or phenothiazine. The hole transport host material may contain one such partial structure, but preferably contains two or more. In the case of containing two or more partial structures, the two or more partial structures may be the same or different from each other.

[0520] Specific examples of the hole-transporting host material include the following compounds.

[0521] [Chemistry 74]

[0522]

[0523] [Chemistry 75]

[0524]

[0525] [Chemistry 76]

[0526]

[0527] [Chemistry 77]

[0528]

[0529] [Chemistry 78]

[0530]

[0531] [Chemistry 79]

[0532]

[0533] [Chemistry 80]

[0534]

[0535] [Chemistry 81]

[0536]

[0537] [Chemistry 82]

[0538]

[0539] [Chemistry 83]

[0540]

[0541] [Chemistry 84]

[0542]

[0543] [Chemistry 85]

[0544]

[0545] [Chemistry 86]

[0546]

[0547] Among the above, preferred ones are HH-1-1, HH-1-2, HH-1-4~HH-1-12, HH-1-17, HH-1-18, HH-1-20~HH-1-24, HH-1 -82, HH-1-84~HH-1-89, HH-1-91, HH-1-92, HH-1-106~HH-1-108, and HH-1-109~HH-1-115.

[0548] [Electron transport host material (EH)]

[0549] Examples of electron transport host materials (EH) include compounds represented by formula (EH-1A) to (EH-1D), or compounds having partial structures represented by formula (EH-1A) to (EH-1D) and having a structure comprising at least three rings selected from the group consisting of aryl rings and heteroaryl rings.

[0550] [Chemistry 87]

[0551]

[0552] In Formula (EH-1A) to Formula (EH-1D),

[0553] Ar is a heteroaryl ring containing N═C as a partial structure constituting the ring,

[0554] Z is a single bond, -O-, -S-, or -N(-A E )-,

[0555] The carbon atoms adjacent to the carbon atom bonded to Z and the A atom bonded to Z E Can bond to each other through L,

[0556] L is a single bond, >O, >S or >C(-A E )2,

[0557] A E is an aryl group, a heteroaryl group, or a triarylsilyl group. In formula (EH-1C), any one A E It may be a diarylamino group,

[0558] Two A's bonded to the same atom E They can bond with each other using L.

[0559] X is C, P or S,

[0560] When X is C, n=2, m=1,

[0561] When X is P, n=3, m=1,

[0562] When X is S, n=2, m=1-2.

[0563] The compounds represented by the formula (EH-1A) to the formula (EH-1D), or the compounds having the partial structures represented by the formula (EH-1A) to the formula (EH-1D), have a structure containing at least three rings selected from the group consisting of aryl rings and heteroaryl rings. The number of rings contained is preferably 4 or more, more preferably 6 or more, and further preferably 8 or more. In addition, it is preferably 20 or less, more preferably 15 or less, and further preferably 10 or less. The number of rings refers to the number as a single ring, and with respect to a condensed ring, it is set to the number obtained by counting the single rings constituting the condensed ring.

[0564] When the electron transport host material includes the structure represented by formula (EH-1A) to formula (EH-1D) as a partial structure, it may include one of the partial structures, but it is also preferred to include two or more. In the case of including two or more, the two or more partial structures may be the same or different from each other. The two or more partial structures may be bonded to each other by a single bond, or they may be bonded in a manner that any ring contained in the partial structure is shared, or they may be bonded in a manner that any ring contained in the partial structure is condensed with each other. The partial structure may further have a substituent selected from an aryl group, a heteroaryl group, a diarylamino group, or an aryloxy group.

[0565] Specific examples of the electron transporting host material include the following compounds.

[0566] [Chemistry 88]

[0567]

[0568] [Chemistry 89]

[0569]

[0570] [Chemistry 90]

[0571]

[0572] [Chemistry 91]

[0573]

[0574] [Chemistry 92]

[0575]

[0576] [Chemistry 93]

[0577]

[0578] [Chemistry 94]

[0579]

[0580] [Chemistry 95]

[0581]

[0582] [Chemistry 96]

[0583]

[0584] Other preferred examples of electron transport host materials (compounds having a partial structure represented by formula (EH-1)) include polycyclic aromatic compounds represented by the following formula (EH-1b) or polymers of polycyclic aromatic compounds having multiple structures represented by the following formula (EH-1b).

[0585] [Chemistry 97]

[0586]

[0587] In formula (EH-1b),

[0588] R 1 , R 2 , R 3 , R 4 and R 5(hereinafter also referred to as “R 1 ", etc.) are each independently hydrogen or a substituent. The substituent only needs to be a substituent selected from the substituent group Z.

[0589] In formula (EH-1b), X 1 and X 2 Each of the following is independently >NR (amine nitrogen), >O, >C(-R)2, >S or >Se, X 1 and X 2 Different from >C(-R)2,

[0590] The R in the >NR and >C(-R)2 is independently hydrogen or a substituent selected from the substituent group Z, and may be further substituted by an aryl group, a heteroaryl group, an alkyl group or a cycloalkyl group (the above is the second substituent). The R in the >NR and >C(-R)2 may be independently bonded to at least one of the a ring, the b ring and the c ring through a linking group or a single bond.

[0591] Y 1 , Y 2 , Y 3 , Y 4 , Y 5 and Y 6 (hereinafter also referred to as "Y 1 ", etc.) are independently =C(-R)- or =N-(pyridinic nitrogen), at least one of which is =N-(pyridinic nitrogen),

[0592] The R in the ═C(—R)— is independently hydrogen or a substituent selected from the substituent group Z.

[0593] The R 1 , R 2 , R 3 , R 4 and R 5 , and as the Y 1 ~Y 6 Adjacent groups in R of =C(-R)- may bond to each other and form an aryl ring or a heteroaryl ring together with at least one of the a ring, b ring and c ring, and at least one hydrogen in the formed ring may be substituted by an aryl group, a heteroaryl group, a diarylamino group, a diheteroarylamino group, an arylheteroarylamino group, a diarylboryl group (two aryl groups may be bonded via a single bond or a linking group), an alkyl group, a cycloalkyl group, an alkoxy group or an aryloxy group (the above are the first substituents), and at least one hydrogen in these groups may be further substituted by an aryl group, a heteroaryl group, an alkyl group or a cycloalkyl group (the above are the second substituents).

[0594] At least one hydrogen in the compound and structure represented by formula (EH-1b) may be substituted by cyano, halogen or deuterium.

[0595] In formula (EH-1b), R 1 , R 2 , R 3 , R 4 and R 5 are hydrogen, or R 3 and R 4 are hydrogen and are selected from R 1 , R 2 and R 5 Any one or more of the group is a substituent other than hydrogen, and the others are hydrogen. As a substituent, an alkyl group, an aryl group that may be substituted by an alkyl group or a heteroaryl group, a heteroaryl group that may be substituted by an alkyl group or an aryl group, or a diarylamino group that may be substituted by an alkyl group or an aryl group is preferred. At this time, as an alkyl group, an alkyl group having 1 to 6 carbon atoms (methyl, tert-butyl, etc.) is preferred, as an aryl group, a phenyl group or a biphenyl group is preferred, and as a heteroaryl group, a triazine group, a carbazolyl group (2-carbazolyl, 3-carbazolyl, 9-carbazolyl, etc.), a pyrimidinyl group, a pyridyl group, a dibenzofuranyl group or a dibenzothienyl group is preferred. As specific examples, phenyl, biphenyl, diphenyltriazine group, carbazolyltriazine group, monophenylpyrimidinyl group, diphenylpyrimidinyl group, carbazolyltriazine group, pyridyl group, dibenzofuranyl group and dibenzothienyl group can be cited.

[0596] Y 1 etc. are independently =C(-R)- or =N-, and at least one is =N-. 1 ~Y 6 Any of may be =N-. Preferably Y 1 and Y 6 =N-(ring a is a pyrimidine ring), Y 1 or Y 6 =N-(ring a is a pyridine ring), Y 2 and Y 5 =N- (ring b and ring c are pyridine rings), Y 3 and Y 4 =N- (ring b and ring c are pyridine rings), Y 2 ~Y 5 =N- (ring b and ring c are pyrimidine rings), Y 1 , Y 3 , Y 4 and Y 6 =N- (ring a is a pyrimidine ring, ring b and ring c are pyridine rings), Y 1 , Y 2 , Y 5 and Y 6 =N- (ring a is a pyrimidine ring, ring b and ring c are pyridine rings), Y 1 ~Y 6 =N- (ring a, ring b and ring c are pyrimidine rings), Y2 or Y 5 =N- (the b ring or the c ring is a pyridine ring).

[0597] In addition to the above arrangement relationship of =N-, it is preferred that X 1 and X 2 is >0, and is preferably a polycyclic aromatic compound including a partial structure represented by any of the following formulae.

[0598] [Chemistry 98]

[0599]

[0600] In particular, polycyclic aromatic compounds containing a partial structure represented by formula (EH-1b-N1) have a higher E S1 , high E T1 , small ΔE S1T1 .

[0601] Specific examples of the polycyclic aromatic compound represented by formula (EH-1b) are shown below.

[0602] [Chemistry 99]

[0603]

[0604] [Chemical 100]

[0605]

[0606] [Chemistry 101]

[0607]

[0608] [Chemistry 102]

[0609]

[0610] [Chemistry 103]

[0611]

[0612] [Chemistry 104]

[0613]

[0614] Among the above, preferred are EH-1-1 to EH-1-4, EH-1-10, EH-1-21 to EH-1-25, EH-1-32, EH-1-33, EH-1-51 to EH-1-59, EH-1-61, EH-1-66, EH-1-68, EH-1-71, and EH-1-7. 2. EH-1-90, EH-1-94~EH-1-99, EH-1-100, EH-1-101, EH-1-104, EH-1- 115. EH-1-117, EH-1-120, EH-1-122, EH-1-123, EH-1-127~EH-1-130.

[0615] [Combination of hole-transporting host material and electron-transporting host material]

[0616] The combination of the hole transporting host material and the electron transporting host material is determined by the HOMO, LUMO and the lowest excited triplet energy level (E T1 ) to select.

[0617] Regarding HOMO and LUMO, a combination is selected in which the HOMO (HH) of the hole-transporting host material is shallower than the HOMO (EH) of the electron-transporting host material, and the LUMO (EH) of the electron-transporting host material is deeper than the LUMO (HH) of the hole-transporting host material. More specifically, a combination in which HOMO (HH) is at least 0.10 eV shallower than HOMO (EH), and LUMO (HH) is at least 0.10 eV deeper than HOMO (EH) is preferably selected, a combination in which HOMO (HH) is at least 0.20 eV shallower than HOMO (EH), and LUMO (HH) is at least 0.20 eV deeper than HOMO (EH) is more preferably selected, and a combination in which HOMO (HH) is at least 0.25 eV shallower than HOMO (EH), and LUMO (HH) is at least 0.25 eV deeper than HOMO (EH) is further preferably selected.

[0618] The hole transporting host material and the electron transporting host material may be a combination of an association body called an exciplex. It is generally known that an exciplex is easily formed between a material having a relatively deep LUMO level and a material having a shallow HOMO level. Regarding the interaction between the hole transporting host material and the electron transporting host material, specifically whether an exciplex is formed, it can be judged in the following manner: a monolayer film containing only the hole transporting host material and the electron transporting host material is formed in the same manner as the formation conditions of the light-emitting layer, and the luminescence spectrum (fluorescence, phosphorescence spectrum) is measured. For the obtained luminescence spectrum, it is compared with the luminescence spectrum displayed by each of the hole transporting host material and the electron transporting host material separately. It can be judged in the following manner: the spectrum of the mixed film containing the hole transporting host material and the electron transporting host material shows a different luminescence wavelength from the spectrum of the film of the hole transporting host material and the spectrum of the film of the electron transporting host material. Specifically, as long as the peak wavelength of the spectrum differs by more than 10nm, it can be used as an indicator.

[0619] As specific examples of the combination of a hole transporting host material and an electron transporting host material that do not form an exciplex, the following combinations can be cited. T1 The physical property values ​​of, in the hole transport host material, preferably a compound having carbazole, dibenzofuran, dibenzothiophene, triarylamine, indolecarbazole and benzoxazinephenoxazine as a partial structure, more preferably a compound having carbazole, dibenzofuran and dibenzothiophene as a partial structure, and further preferably a compound having carbazole as a partial structure. Similarly, in the electron transport host material, preferably a compound having pyridine, triazine, phosphine oxide, benzofuranopyridine and dibenzooxasiloline as a partial structure, more preferably a compound having triazine, phosphine oxide, benzofuranopyridine and dibenzooxasiloline as a partial structure, and further preferably a compound having triazine.

[0620] More specifically, the hole transport host material is preferably selected from the group consisting of HH-1-1, HH-1-2, HH-1-4 to HH-1-12, HH-1-17, HH-1-18, HH-1-20 to HH-1-24, HH-1-82, HH-1-84 to HH-1-89, HH-1-91, HH-1-92 and HH-1-106 to HH-1-108, and the electron transport host material is preferably selected from the group consisting of EH-1-1 to EH-1-4, EH-1-10, EH-1-21~EH-1-25, EH-1-32, EH-1-33, EH-1-51~EH-1-59, EH-1-61, EH-1-71, EH-1-72, EH-1-90, In the group consisting of EH-1-100, EH-1-101, EH-1-104, EH-1-117, EH-1-120, EH-1-122, EH-1-123, and EH-1-127~EH-1-130. Preferred examples of combinations include compound HH-1-1 and compound EH-1-22, compound HH-1-1 and compound EH-1-23, compound HH-1-1 and compound EH-1-24, compound HH-1-2 and compound EH-1-22, compound HH-1-2 and compound EH-1-23, compound HH-1-2 and compound EH-1-24, or compound HH-1-1 and compound EH-1-128.

[0621] As specific examples of the combination of a hole transporting host material and an electron transporting host material that form an exciplex, the following combinations can be cited. T1 The physical property values ​​of, in the hole transport host material, preferably a compound having carbazole, triarylamine, indolecarbazole and benzoxazine and phenoxazine as a partial structure, more preferably a compound having triarylamine, indolecarbazole and benzoxazine and phenoxazine as a partial structure, and further preferably a compound having triarylamine as a partial structure. Similarly, in the electron transport host material, preferably a compound having pyridine, triazine, phosphine oxide and benzofuranopyridine as a partial structure, more preferably a compound having triazine, phosphine oxide, benzofuranopyridine and dibenzooxasiloline as a partial structure, and further preferably a compound having phosphine oxide and triazine.

[0622] More specifically, the hole transport host material is preferably selected from the group consisting of HH-1-1, HH-1-2, HH-1-11, HH-1-12, HH-1-17, HH-1-18, HH-1-23, HH-1-24, and HH-1-115, and the electron transport host material is preferably selected from the group consisting of EH-1-1 to EH-1-4, EH-1-21 to EH-1-25, EH-1 -51~EH-1-57, EH-1-59, EH-1-66, EH-1-68, EH-1-90, EH-1-94, EH-1-99, EH-1-100, EH-1-101, EH-1-104, EH-1-117, EH-1-120, EH-1-122, EH-1-123, and the group consisting of EH-1-127~EH-1-130. Preferred examples of combinations include compound HH-1-1 and compound EH-1-21, compound HH-1-2 and compound EH-1-21, compound HH-1-12 and compound EH-1-94, compound HH-1-12 and compound EH-1-117, compound HH-1-1 and compound EH-1-130, compound HH-1-33 and compound EH-1-117, compound HH-1-48 and compound EH-1-117, compound HH-1-49 and compound EH-1-117, or compound HH-1-115 and compound EH-1-99.

[0623] In addition, for specific combinations of hole-transporting host materials and electron-transporting host materials, please refer to: Organic Electronics (66 (2019) 227-24), Advanced Functional Materials (25 (2015) 361-366.), Advanced Materials (26 (2014) 4730-4734.), ACS Applied Materials and Interfaces (8 (2016) 32984-32991.), ACS Applied Materials and Interfaces (2016, 8, 9806-9810), ACS Applied Materials and Interfaces (2016, 8, 32984-32991), Journal of Materials Chemistry (Journal of Materials Chemistry) Materials Chemistry" (C, 2018, 6, 8784-8792), "Angewandte Chemie International Edition." (2018, 57, 12380-12384), "Advanced Functional Materials" (24, 2014, 3970), "Advanced Materials" (26, 2014, 5684), "Synthetic Metals" (201, 2015, 49) and "Nature Photonics" (16, 212-218 (2022)).

[0624] <Dopant materials>

[0625] In addition to the polycyclic aromatic compound of the present invention, known compounds can be used as dopant materials, and can be selected from various materials according to the desired luminescent color. Specifically, for example, phenanthrene, anthracene, pyrene, tetracene, pentacene, perylene, naphthopyrene, dibenzopyrene, rubrene, and Condensed ring derivatives such as 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, bisstyrylanthracene derivatives or stilbenebenzene derivatives such as bisstyrylanthracene derivatives (Japanese Patent Laid-Open No. 1-245087), bisstyrylarylene derivatives (Japanese Patent Laid-Open No. 2-247278), diazabenzodiindene derivatives, furan derivatives, benzofuran derivatives, phenylisobenzofuran, dimesitylisobenzofuran, di(2-methylphenyl)isobenzofuran, di(2-trifluoromethylphenyl)isobenzofuran, isobenzofuran derivatives such as phenylisobenzofuran, dibenzofuran derivatives, 7-dialkylaminocoumarin derivatives, 7- Coumarin derivatives such as piperidinyl coumarin derivatives, 7-hydroxycoumarin derivatives, 7-methoxycoumarin derivatives, 7-acetoxycoumarin derivatives, 3-benzothiazolyl coumarin derivatives, 3-benzimidazolyl coumarin derivatives, 3-benzoxazolyl coumarin derivatives, dicyanomethylene pyran derivatives, dicyanomethylene thiopyran derivatives, polymethine derivatives, cyanine derivatives, oxybenzanthracene derivatives, xanthene derivatives, rhodamine derivatives, fluorescein Derivatives, pyrylium derivatives, quinolone derivatives, acridine derivatives, oxazine derivatives, phenyl ether derivatives, quinacridone derivatives, quinazoline derivatives, pyrrolopyridine derivatives, furanopyridine derivatives, 1,2,5-thiadiazolopyrene derivatives, pyrromethene derivatives, purple ring ketone derivatives, pyrrolopyrrole derivatives, squarylium salt derivatives, purple anthrone derivatives, phenazine derivatives, acridone derivatives, deazotflavin derivatives, fluorene derivatives and benzofluorene derivatives, etc.

[0626] As the dopant material, it is also preferable to use a polycyclic aromatic compound containing boron described in International Publication No. 2015 / 102118, International Publication No. 2020 / 162600, paragraphs 0097 to 0269 of Japanese Patent Application Laid-Open No. 2021-077890, and the like.

[0627] <Assisted dopant (thermally activated delayed phosphor or phosphorescent material)>

[0628] The light-emitting layer also preferably contains an emission dopant, a host material, and an auxiliary dopant. The auxiliary dopant is preferably a thermally active delayed phosphor or a phosphorescent material. The polycyclic aromatic compound of the present invention can be preferably used as an emission dopant in a TAF element or a PSF element.

[0629] In this form, as the main compound, a known compound can be used, for example, a compound having at least one of a carbazole ring and a furan ring, wherein a compound in which at least one of a furanyl group and a carbazole group is bonded to at least one of an arylene group and a heteroarylene group is preferably used. As a specific example, mCP (1,3-bis (N-carbazole-9-yl) benzene) or mCBP (3,3'-bis (9H-carbazole-9-yl) -1,1'-biphenyl) can be listed. In addition, a TADF-active compound can also be used in the main compound.

[0630] In this aspect, it is also preferable to use a combination of a hole-transporting host material and an electron-transporting host material (for example, compound HH-1-115 and compound EH-1-99) as a host.

[0631] From the viewpoint of promoting rather than inhibiting the generation of TADF in the light-emitting layer, the lowest excited triplet energy level E(1, T, Sh) of the host compound obtained from the shoulder peak on the short-wavelength side of the peak of the phosphorescence spectrum is preferably higher than the lowest excited triplet energy levels E(2, T, Sh) and E(3, T, Sh) of the emitting dopant or the auxiliary dopant having the highest lowest excited triplet energy level in the light-emitting layer. Specifically, the lowest excited triplet energy level E(1, T, Sh) of the host compound is preferably higher by 0.01 eV or more, more preferably higher by 0.03 eV or more, and further preferably higher by 0.1 eV or more than E(2, T, Sh) and E(3, T, Sh). In addition, the lowest excited triplet energy level E of the host material is preferably higher than 2.70 eV, more preferably higher than 2.73 eV, and further preferably higher than 2.80 eV.

[0632] [Thermally activated delayed phosphor]

[0633] The so-called "thermally activated delayed fluorescence" refers to a compound that absorbs thermal energy and undergoes reverse intersystem crossing from the lowest excited triplet state to the lowest excited singlet state, and is radiatively deactivated from the lowest excited singlet state, thereby emitting delayed fluorescence. The so-called "thermally activated delayed fluorescence" also includes the case where a higher-order triplet state is passed during the excitation process from the lowest excited triplet state to the lowest excited singlet state. For example, there are the papers published by Monkman et al. of Durham University (Nature Communications (7: 13680, digital object identifier (DOI) : 10.1038 / ncomms13680)), the papers published by Hosokai et al. of the National Institute of Advanced Industrial Science and Technology (Hosokai et al., Science Advances (Sci. Adv.) (2017; 3: e1603282)), and the papers published by Sato et al. of Kyoto University (Scientific Reports (2017)). 4820, DOI: 10.1038 / s41598-017-05007-7)), and a society paper by Sato et al. of Kyoto University (98th Spring Annual Meeting of the Chemical Society of Japan, publication number: 2I4-15, "Mechanism of high-efficiency luminescence in organic electroluminescence using diazaboranaphthoanthracene (DABNA) as a luminescent molecule," Journal of the Graduate School of Engineering, Kyoto University The present invention relates to a sample containing a target compound, and the target compound is determined to be a "thermally activated delayed fluorescent substance" by observing a slow fluorescent component when the fluorescence lifetime is measured at 300K. Here, the so-called slow fluorescent component refers to a component with a fluorescence lifetime of 0.1 μsec or more. The fluorescence lifetime can be measured, for example, using a fluorescence lifetime measuring apparatus (manufactured by Hamamatsu Photonics Co., Ltd., C11367-01).

[0634] In the light-emitting layer further including a "thermally active delayed phosphor" as an auxiliary dopant, the polycyclic aromatic compound of the present invention can function as an emitting dopant. That is, the "thermally active delayed phosphor" can function as an auxiliary dopant that assists the light emission of the polycyclic aromatic compound of the present invention.

[0635] In this specification, an organic electroluminescent element using a thermally activated delayed phosphor as an assisting dopant may be referred to as a "TAF element" (TADF Assisting Fluorescence element).

[0636] The so-called "host compound" in the TAF element refers to a compound whose lowest excited singlet energy level obtained from the shoulder peak on the short-wavelength side of the peak of the fluorescence spectrum is higher than the lowest excited singlet energy level of the thermally active delayed phosphor as an auxiliary dopant and the emitting dopant.

[0637] The thermally active delayed phosphor (TADF compound) used in the TAF element is preferably the following donor-acceptor type thermally active delayed phosphor (DA-type TADF compound): it is designed to use an electron-donating substituent called a donor and an electron-accepting substituent called an acceptor to localize the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) in the molecule to produce efficient reverse intersystem crossing.

[0638] Here, in this specification, the so-called "electron donating substituent" (donor) refers to the substituent and partial structure locally present at HOMO in the thermally active delayed phosphor molecule, and the so-called "electron accepting substituent" (acceptor) refers to the substituent and partial structure locally present at LUMO in the thermally active delayed phosphor molecule.

[0639] Generally speaking, due to the structure of the thermally activated delayed fluorescent material using donors or acceptors, the spin orbit coupling (SOC) is large, and the exchange interaction between HOMO and LUMO is small, so ΔE S1T1Small, so a very fast reverse intersystem crossing speed can be obtained. By using the polycyclic aromatic compound of the present invention as an emitting dopant and using a thermally active delayed phosphor (TADF material) as an auxiliary dopant, an element that satisfies any one or all of high efficiency, high color purity and long life can be provided. The thermally active delayed phosphor can be any compound whose luminescence spectrum overlaps at least partially with the absorption spectrum of the polycyclic aromatic compound of the present invention. The polycyclic aromatic compound and TADF compound of the present invention may be both contained in the same layer, or in adjacent layers or other adjacent layers.

[0640] As the thermally active delayed phosphor in the TAF element, for example, a compound in which a donor and an acceptor are bonded directly or via a spacer can be used. As the electron-donating group (donor structure) and the electron-accepting group (acceptor structure) used in the thermally active delayed phosphor of the present invention, for example, the structure described in "Chemistry of Materials" (2017, 29, 1946-1963) can be used. Examples of the donor structure include carbazole, dimethylcarbazole, di-tert-butylcarbazole, dimethoxycarbazole, tetramethylcarbazole, benzofluorocarbazole, benzothiophenocarbazole, phenyldihydroindolecarbazole, phenylbicarbazole, bicarbazole, tercarbazole, diphenylcarbazole-based amine, tetraphenylcarbazole-based diamine, phenoxazine, dihydrophenazine, phenothiazine, dimethyldihydroacridine, diphenylamine, bis(tert-butylphenyl)amine, N1-(4-(diphenylamino)phenyl)-N4,N4-diphenylbenzene-1,4-diamine, dimethyltetraphenyldihydroacridine diamine, tetramethyl-dihydro-indenoacridine and diphenyl-dihydrodibenzazasilin, etc. Examples of the acceptor structure include sulfonyldiphenyl, benzophenone, phenylenebis(phenyl ketone), benzonitrile, isonicotinonitrile, phthalonitrile, isophthalonitrile, terephthalonitrile, benzenetricarbonitrile, triazole, oxazole, thiadiazole, benzothiazole, benzobis(thiazole), benzoxazole, benzobis(oxazole), quinoline, benzimidazole, dibenzoquinoxaline, heptaazaphenalene, thioxanthone dioxide, dimethylanthrone, anthracene dione, 5H-cycloheptyl[1,2-b:5,4-b′]bipyridine, fluorene dicarbonitrile, triphenyltriazine, pyrazine dicarbonitrile, pyrimidine, phenylpyrimidine, methylpyrimidine, pyridine dicarbonitrile, dibenzoquinoxaline dicarbonitrile, bis(phenylsulfonyl)benzene, dimethylthioxanthene dioxide, thianthrene tetraoxide, and tri(dimethylphenyl)borane. In particular, the compound having thermally activated delayed fluorescence in the TAF element is preferably a compound having at least one selected from carbazole, phenoxazine, acridine, triazine, pyrimidine, pyrazine, thioxanthene, benzonitrile, phthalonitrile, isophthalonitrile, diphenyl sulfone, triazole, oxadiazole, thiadiazole and benzophenone as a partial structure.

[0641] The compound used as an auxiliary dopant of the light-emitting layer in the TAF device is preferably a thermally activated delayed phosphor, and its emission spectrum at least partially overlaps with the absorption peak of the emitting dopant.

[0642] [Phosphorescent materials]

[0643] In the light-emitting layer, a phosphorescent material can be used as an auxiliary dopant. In this specification, an organic electroluminescent element using a phosphorescent material as an auxiliary dopant is sometimes referred to as a phosphorescent auxiliary element: a phosphor-sensitized fluorescent element, a PSF element. Phosphorescent materials utilize the intramolecular spin-orbit interaction (heavy atom effect) caused by metal atoms to obtain light emission from an excited triplet state. As such a phosphorescent material, for example, a luminescent metal complex can be used. As the luminescent metal complex, for example, compounds represented by the following formula (B-1) and the following formula (B-2) can be listed.

[0644] [Chemistry 105]

[0645]

[0646] 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 of 1 to 3, and "XY" are each independently a bidentate ligand.

[0647] In formula (B-2), M is at least one selected from the group consisting of Pt, Re and Cu, and "WXYZ" is a tetradentate ligand.

[0648] In formula (B-1), M is preferably Ir and n is preferably 3 from the viewpoint of efficiency and life.

[0649] In formula (B-2), M is preferably Pt from the viewpoint of efficiency and life.

[0650] The ligand (XY) in formula (B-1) has at least one ligand selected from the group consisting of: The ligand (WXYZ) in formula (B-2) has at least one ligand selected from the group consisting of: as a part thereof.

[0651] [Chemistry 106]

[0652]

[0653] In the formula,

[0654] It is bonded to the central metal M at ---,

[0655] Y is independently BRe NR e , PR e ,O,S,Se,C=O,S=O,SO2,CR e R f 、SiR e R f , or GeR e R f ,

[0656] The aromatic carbon CH in the ring can be substituted with N independently.

[0657] R e and R f Can be condensed or bonded to form a ring,

[0658] R a , R b , R c and R d Each independently is unsubstituted or substituted to a range from 1 to the maximum number of substitutions possible,

[0659] R a , R b , R c , R d , R e , and R f are independently hydrogen, deuterium, halide, alkyl, cycloalkyl, heteroalkyl, alkoxy, aryloxy, amino, silanyl, alkenyl, cycloalkenyl, heteroalkenyl, aryl, heteroaryl, nitrile, isonitrile, thiol or a combination thereof,

[0660] Among them, R a , R b , R c , and R d Any two adjacent substituents in the group may be condensed or bonded to form a ring, or may form a multidentate ligand.

[0661] 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), and fac-Tris(2-(3-p-xylyl)phenyl)pyridine iridium(III)(fac-tris(2-(3-p-xylyl)phenyl)pyridinium(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.

[0662] Examples of the compound represented by formula (B-1) include the following compounds in addition to the above.

[0663] [Chemistry 107]

[0664]

[0665] [Chemistry 108]

[0666]

[0667] [Chemistry 109]

[0668]

[0669] In addition, iridium complexes described in Japanese Patent Laid-Open No. 2006-089398, Japanese Patent Laid-Open No. 2006-080419, Japanese Patent Laid-Open No. 2005-298483, Japanese Patent Laid-Open No. 2005-097263, and Japanese Patent Laid-Open No. 2004-111379, U.S. Patent Application Publication No. 2019 / 0051845, or Advanced Materials (26: 7116-7121), Nature Asia Materials (NPG Asia Materials) (13, 53 (2021)), Applied Physics Letters (Applied Physics Letters) (117, 253301 (2020)), Light-Emitting Diode-An Outlook On the Empirical Features and Its Recent Technological Progress Outlook (Light-Emitting Diode-An Outlook On the Empirical Features and Its Recent Technological Progress Outlook) can also be used. The platinum complex described in "Technological Advances" (Chapter 5).

[0670] 2-1-6. Electron injection layer and electron transport layer in organic electroluminescent element

[0671] The electron injection layer 107 plays a role of efficiently injecting electrons migrated from the cathode 108 into the light-emitting layer 105 or the electron transport layer 106. The electron transport layer 106 plays a role of efficiently transporting electrons injected from the cathode 108 or electrons injected from the cathode 108 via the electron injection layer 107 to the light-emitting layer 105. The electron transport layer 106 and the electron injection layer 107 are respectively formed by stacking or mixing one or more electron transport / injection materials, or are formed by a mixture of an electron transport / injection material and a polymer binder.

[0672] The so-called electron injection / transport layer is a layer responsible for injecting electrons from the cathode and then transmitting electrons, and it is desirable that the electron injection efficiency is high and the injected electrons are transmitted efficiently. Therefore, it is preferably a material with large electron affinity, large electron mobility, excellent stability, and impurities that are not easy to produce when manufacturing and using it. However, considering the transmission balance of holes and electrons, in the case of mainly playing the role of efficiently preventing the holes from the anode from being recombined and flowing to the cathode side, even if the electron transmission ability is not so high, it has the effect of improving luminous efficiency equally with the material with high electron transmission ability. Therefore, the electron injection / transport layer in the present embodiment may also include the function of the layer that can efficiently prevent the migration of holes.

[0673] The material (electron transport material) for forming the electron transport layer 106 or the electron injection layer 107 can be arbitrarily selected from compounds conventionally used as electron transfer compounds in photoconductive materials and known compounds used in electron injection layers and electron transport layers of organic EL elements.

[0674] As the material used in the electron transport layer or the electron injection layer, it is preferably containing at least one selected from the following compounds: a compound containing an aromatic ring or heteroaromatic ring containing one or more atoms selected from carbon, hydrogen, oxygen, sulfur, silicon and phosphorus; a pyrrole derivative and its condensed ring derivative; and a metal complex with electron-accepting nitrogen. Specifically, it can be listed: condensed ring aromatic ring derivatives such as naphthalene and anthracene, styrene aromatic ring derivatives represented by 4,4'-bis(diphenylvinyl)biphenyl, purple ring ketone derivatives, coumarin derivatives, naphthalene dicarboximide derivatives, quinone derivatives such as anthraquinone or diphenoquinone, phosphine oxide derivatives, aryl nitrile derivatives and indole derivatives. As a metal complex with electron-accepting nitrogen, for example, hydroxyl oxazole complexes such as hydroxyphenyloxazole complexes, azomethine complexes, tropolone metal complexes, flavonol metal complexes and benzoquinoline metal complexes can be listed. These materials can be used alone or mixed with different materials.

[0675] In addition, specific examples of other electron transfer compounds include pyridine derivatives, naphthalene derivatives, anthracene derivatives, phenanthroline derivatives, perirone derivatives, coumarin derivatives, naphthalimide derivatives, anthraquinone derivatives, diphenoquinone derivatives, diphenylquinone derivatives, perylene derivatives, oxadiazole derivatives (1,3-bis[(4-tert-butylphenyl)1,3,4-oxadiazolyl]phenylene, etc.), thiophene derivatives, triazole derivatives (N-naphthyl-2,5-diphenyl-1,3,4-triazole, etc.), thiadiazole derivatives, metal complexes of 8-hydroxyquinoline derivatives, hydroxyquinoline metal complexes, quinoxaline derivatives, polymers of quinoxaline derivatives, benzoazole compounds, gallium complexes, pyrazole derivatives, perfluorinated phenylene derivatives, Biologicals, triazine derivatives, pyrazine derivatives, benzoquinoline derivatives (2,2'-bis(benzo[h]quinolin-2-yl)-9,9'-spirobifluorene, etc.), imidazopyridine derivatives, borane derivatives, benzimidazole derivatives (tris(N-phenylbenzimidazol-2-yl)benzene, etc.), benzoxazole derivatives, benzothiazole derivatives, quinoline derivatives, oligopyridine derivatives such as terpyridine, bipyridine derivatives, terpyridine derivatives (1,3-bis(2,2':6',2"-terpyridine-4'-yl)benzene, etc.), naphthyridine derivatives (bis(1-naphthyl)-4-(1,8-naphthyridin-2-yl)phenylphosphine oxide, etc.), aldazine derivatives, carbazole derivatives, indole derivatives, phosphine oxide derivatives, bisphenylvinyl derivatives, etc.

[0676] In addition, metal complexes having electron-accepting nitrogen can also be used, examples of which include hydroxyquinoline metal complexes, hydroxyoxazole complexes such as hydroxyphenyloxazole complexes, azomethine complexes, tropolone metal complexes, flavonol metal complexes, and benzoquinoline metal complexes.

[0677] The materials can be used alone or in combination with different materials.

[0678] Among the above materials, preferred are borane derivatives, pyridine derivatives, fluoranthene derivatives, BO derivatives, anthracene derivatives, benzofluorene derivatives, phosphine oxide derivatives, pyrimidine derivatives, aromatic nitrile derivatives, triazine derivatives, benzimidazole derivatives, phenanthroline derivatives, and hydroxyquinoline metal complexes.

[0679] <Reducing substances>

[0680] The electron transport layer or the electron injection layer may also contain a substance that can reduce the material forming the electron transport layer or the electron injection layer. As long as the reducing substance has a certain reducing property, various substances can be used, for example, at least one selected from the group consisting of alkali metals, alkaline earth metals, rare earth metals, alkali metal oxides, alkali metal halides, alkaline earth metal oxides, alkaline earth metal halides, rare earth metal oxides, rare earth metal halides, alkali metal organic complexes, alkaline earth metal organic complexes and rare earth metal organic complexes can be preferably used.

[0681] As preferred reducing substances, alkali metals such as Na (work function 2.36eV), K (work function 2.28eV), Rb (work function 2.16eV) or Cs (work function 1.95eV) or alkaline earth metals such as Ca (work function 2.9eV), Sr (work function 2.0eV~2.5eV) or Ba (work function 2.52eV) can be listed, and substances with a work function of 2.9eV or less are particularly preferred. Among these, the more preferred reducing substances are alkali metals of K, Rb or Cs, and more preferably Rb or Cs, and most preferably Cs. The reducing ability of these alkali metals is particularly high. By adding a relatively small amount of the alkali metal to the material forming the electron transport layer or the electron injection layer, the luminous brightness in the organic EL element can be improved or the life can be prolonged. In addition, as the reducing substance having a work function of 2.9 eV or less, a combination of two or more of these alkali metals is also preferred, and a combination containing Cs is particularly preferred, such as a combination of Cs and Na, Cs and K, Cs and Rb, or Cs and Na and K. By including 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, the luminance of the light emission in the organic EL element can be improved or the life can be prolonged.

[0682] 2-1-7. Cathode in organic electroluminescent element

[0683] The cathode 108 plays a role of injecting electrons into the light-emitting layer 105 via the electron injection layer 107 and the electron transport layer 106 .

[0684] As the material forming the cathode 108, if it is a substance that can efficiently inject electrons into the organic layer, it is not particularly limited, and the same material as the material forming the anode 102 can be used. Among them, preferably metals such as tin, indium, calcium, aluminum, silver, copper, nickel, chromium, gold, platinum, iron, zinc, lithium, sodium, potassium, cesium and magnesium or their alloys (magnesium-silver alloy, magnesium-indium alloy, aluminum-lithium alloy such as lithium fluoride / aluminum, etc.) and the like. In order to improve the efficiency of electron injection to improve the characteristics of the element, lithium, sodium, potassium, cesium, calcium, magnesium or alloys containing these low work function metals are effective. However, generally speaking, these low work function metals are unstable in the atmosphere in most cases. In order to improve this point, it is known that there is a method of doping a trace amount of lithium, cesium or magnesium into the organic layer and using an electrode with high stability. As other dopants, inorganic salts such as lithium fluoride, cesium fluoride, lithium oxide and cesium oxide can also be used. Among them, it is not limited to these.

[0685] Furthermore, the following are preferred examples: for protecting the electrodes, metals such as platinum, gold, silver, copper, iron, tin, aluminum and indium, or alloys of these metals, inorganic substances such as silicon dioxide, titanium dioxide and silicon nitride, polyvinyl alcohol, vinyl chloride, hydrocarbon polymer compounds, etc. are stacked. The method for making these electrodes is not particularly limited as long as it is a method that can achieve conduction such as resistance heating, electron beam evaporation, sputtering, ion plating and coating.

[0686] 2-1-8. Method for producing organic electroluminescent element

[0687] Each layer constituting the organic EL element can be formed by making the material to constitute each layer into a thin film using a method such as vapor deposition, resistance heating vapor deposition, electron beam vapor deposition, sputtering, molecular stacking, printing, spin coating, casting, coating, etc. The film thickness of each layer formed in the above manner is not particularly limited and can be appropriately set according to the properties of the material, but is generally in the range of 2nm to 5000nm. The film thickness can generally be measured using a quartz oscillation film thickness measuring device or the like. When using the vapor deposition method for thin film formation, the vapor deposition conditions vary depending on the type of material, the target crystal structure and association structure of the film, etc. The vapor deposition conditions are generally preferably a boat heating temperature of +50°C to +400°C and a vacuum degree of 10 -6 Pa~10 -3 Pa, the vapor deposition rate is 0.01 nm / sec to 50 nm / sec, the substrate temperature is -150°C to +300°C, and the film thickness is appropriately set within the range of 2 nm to 5 μm.

[0688] When a direct current voltage is applied to the organic EL element obtained in the above manner, it can be applied with the anode as + polarity and the cathode as - polarity. If a voltage of about 2V to 40V is applied, light emission can be observed from the transparent or translucent electrode side (anode or cathode, or both). In addition, the organic EL element also emits light when a pulse current or an alternating current is applied. In addition, the waveform of the applied alternating current can be arbitrary.

[0689] Next, as an example of a method for producing an organic EL element, a method for producing an organic EL element including anode / hole injection layer / hole transport layer / light-emitting layer including a host material and a dopant material / electron transport layer / electron injection layer / cathode is described.

[0690] <Evaporation method>

[0691] On a suitable substrate, a thin film of an anode material is formed by a vapor deposition method to make an anode, and then a thin film of a hole injection layer and a hole transport layer is formed on the anode. The main material and the dopant material are co-evaporated on the thin film to form a thin film as a light-emitting layer, and an electron transport layer and an electron injection layer are formed on the light-emitting layer, and then a thin film containing a cathode material is formed by a vapor deposition method as a cathode, thereby obtaining a target organic EL element. In addition, in the production of the organic EL element, the production order can also be reversed, and the cathode, electron injection layer, electron transport layer, light-emitting layer, hole transport layer, hole injection layer, anode are produced in the order of cathode, electron injection layer, electron transport layer, light-emitting layer, hole transport layer, hole injection layer, anode.

[0692] <Wet film forming method>

[0693] A low molecular weight compound capable of forming each organic layer of an organic EL element is prepared as a liquid organic layer-forming composition, and the composition is used to perform a wet film-forming method. In the absence of an appropriate organic solvent for dissolving the low molecular weight compound, the organic layer-forming composition may be prepared from a high molecular weight compound or the like, wherein the high molecular weight compound is polymerized together with other monomers or main chain polymers having a solubility function as a reactive compound substituted with a reactive substituent in the low molecular weight compound.

[0694] The wet film forming method generally forms a coating film by passing through the following process, wherein the process is a coating process of applying an organic layer forming composition on a substrate and a drying process of removing a solvent from the coated organic layer forming composition. In the case where the polymer compound has a cross-linking substituent (also referred to as a cross-linking polymer compound), the drying process is further cross-linked to form a polymer cross-linked body. Depending on the coating process, the method using a spin coater is called a spin coating method, the method using a slit coater is called a slit coating method, the method using a plate is called a gravure, lithography, reverse lithography, flexographic printing method, the method using an inkjet printer is called an inkjet method, and the method of blowing with a mist is called a spray method. There are methods such as air drying, heating, and reduced pressure drying in the drying process. The drying process can be performed only once, or it can be performed multiple times using different methods or conditions. In addition, for example, different methods can also be used, such as calcination under reduced pressure.

[0695] The wet film forming method refers to a film forming method using a solution, such as a partial printing method (inkjet method), a spin coating method or a casting method, a coating method, etc. The wet film forming method is different from the vacuum evaporation method in that it does not require the use of an expensive vacuum evaporation device and can be formed under atmospheric pressure. In addition, the wet film forming method can be large-scale or continuously produced, thereby reducing manufacturing costs.

[0696] On the other hand, compared with the vacuum evaporation method, the wet film forming method is sometimes difficult to laminate. When using the wet film forming method to make a laminated film, it is necessary to prevent the dissolution of the lower layer caused by the composition of the upper layer, and use a composition with controlled solubility, crosslinking of the lower layer, and an orthogonal solvent (orthogonal solvent, mutually insoluble solvent) etc. However, there are cases where it is difficult to use the wet film forming method for coating all films even if these technologies are used.

[0697] Therefore, a method is generally adopted in which only some layers are formed by a wet film-forming method and the remaining layers are formed by a vacuum deposition method to produce an organic EL element.

[0698] For example, the following shows a part of the procedure for manufacturing an organic EL element by applying the wet film formation method.

[0699] (Procedure 1) Anode film formation by vacuum deposition method

[0700] (Procedure 2) Film formation of a hole injection layer-forming composition containing a hole injection layer material by a wet film formation method

[0701] (Procedure 3) Film formation of a hole transport layer-forming composition containing a hole transport layer material by a wet film formation method

[0702] (Procedure 4) Film formation of a composition for forming a light-emitting layer containing a host material and a dopant material by a wet film formation method

[0703] (Procedure 5) Film formation of electron transport layer by vacuum deposition method

[0704] (Procedure 6) Film formation of electron injection layer by vacuum deposition method

[0705] (Procedure 7) Cathode film formation by vacuum deposition method

[0706] By going through the above process, an organic EL element including anode / hole injection layer / hole transport layer / light-emitting layer including a host material and a dopant material / electron transport layer / electron injection layer / cathode can be obtained.

[0707] Of course, for the electron transport layer and the electron injection layer, a layer-forming composition containing an electron transport layer material and an electron injection layer material can also be used to form a film by a wet film-forming method. In this case, it is preferred to use a method that prevents the lower light-emitting layer from dissolving, or a method of forming a film from the cathode side in the opposite manner to the above procedure.

[0708] <Other film forming methods>

[0709] Laser heating drawing method (Laser Induced Thermal Imaging (LITI)) can be used for film formation of the organic layer-forming composition. LITI refers to a method of heating and evaporating a compound attached to a substrate using a laser, and the organic layer-forming composition can be used in the material coated on the substrate.

[0710] <Optional process>

[0711] Before and after each film forming step, appropriate treatment steps, cleaning steps and drying steps may be appropriately added. Examples of treatment steps include exposure treatment, plasma surface treatment, ultrasonic treatment, ozone treatment, cleaning treatment using an appropriate solvent and heating treatment. Furthermore, a series of steps for making a bank may be mentioned.

[0712] Photolithography can be used in the production of the bank. As the bank material that can be photolithographically processed, positive resist materials and negative resist materials can be used. In addition, printing methods that can be patterned, such as inkjet printing, gravure lithography, reverse lithography, and screen printing, can also be used. At this time, a permanent resist material can also be used.

[0713] Examples of materials for the embankment include polysaccharides and their derivatives, homopolymers and copolymers of vinyl monomers having hydroxyl groups, biopolymers, polyacryl compounds, polyesters, polystyrene, polyimides, polyamide-imides, polyether-imides, polysulfides, polysulfones, polyphenylene, polyphenylene ether, polyurethanes, (meth) epoxy acrylates, (meth) melamine acrylates, polyolefins, cyclic polyolefins, acrylonitrile-butadiene-styrene copolymers (ABS), silicone resins, polyvinyl chloride, chlorinated polyethylene, chlorinated polypropylene, polyacetate, polynorbornene, synthetic rubber, fluorinated polymers such as polyvinylidene fluoride, polytetrafluoroethylene, and polyhexafluoropropylene, copolymers of fluoroolefins and hydrocarbon olefins, and fluorocarbon polymers, but the present invention is not limited to these.

[0714] <Organic layer forming composition used in wet film forming method>

[0715] The composition for forming an organic layer is obtained by dissolving a low molecular compound that can 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 luminescent layer contains at least one dopant material, i.e., a polycyclic aromatic compound (or its high molecular compound) as a first component, at least one main material as a second component, and at least one organic solvent as a third component. The first component functions as a dopant component of the luminescent layer obtained from the composition, and the second component functions as a main component of the luminescent layer. The third component functions as a solvent that dissolves the first component and the second component in the composition, and provides a smooth and uniform surface shape by using the controlled evaporation rate of the third component itself during coating.

[0716] <Organic solvent>

[0717] The organic layer forming composition comprises at least one organic solvent. By controlling the evaporation rate of the organic solvent during film formation, the film forming property and the presence or absence of defects, surface roughness, and smoothness of the coating film can be controlled and improved. In addition, when using the inkjet method for film formation, the stability of the meniscus at the pinhole of the inkjet head can be controlled, and the ejection property can be controlled / improved. In addition, by controlling the drying rate of the film and the orientation of the derivative molecules, the electrical properties, luminescent properties, efficiency, and life of the organic EL element having the organic layer obtained by the organic layer forming composition can be improved.

[0718] (1) Physical properties of organic solvents

[0719] The boiling point of at least one organic solvent is 130°C to 300°C, more preferably 140°C to 270°C, and further preferably 150°C to 250°C. From the perspective of inkjet ejection, the boiling point is preferably higher than 130°C. In addition, from the perspective of defects, surface roughness, residual solvent and smoothness of the coating film, the boiling point is preferably lower than 300°C. From the perspective of good inkjet ejection, film forming properties, smoothness and less residual solvent, the organic solvent is more preferably a composition containing two or more organic solvents. On the other hand, depending on the situation, taking into account transportability, etc., it can also be a composition made into a solid state by removing the solvent from the organic layer forming composition.

[0720] Furthermore, the organic solvent includes a good solvent (GS) and a poor solvent (PS) for at least one of the solutes, and the boiling point (BP) of the good solvent (GS) is particularly preferably GS ) is lower than the boiling point (BP) of the bad solvent (PS) PS ) composition.

[0721] By adding a high-boiling-point poor solvent, the low-boiling-point good solvent evaporates first during film formation, increasing the concentration of the components and the poor solvent in the composition and promoting rapid film formation. As a result, a coating film with fewer defects, less surface roughness, and high smoothness can be obtained.

[0722] The difference in solubility (S GS -S PS ) is preferably 1% or more, more preferably 3% or more, and still more preferably 5% or more. The difference in boiling point (BP PS -BP GS ) is preferably 10°C or higher, more preferably 30°C or higher, and further preferably 50°C or higher.

[0723] The organic solvent is removed from the coating by drying processes such as vacuum, decompression, heating, etc. after film formation. When heating, from the perspective of improving the coating film-forming property, it is preferably carried out below the glass transition temperature (Tg) of at least one of the solutes + 30 ° C. In addition, from the perspective of reducing the residual solvent, it is preferably heated above the glass transition temperature (Tg) of at least one of the solutes -30 ° C. Even if the heating temperature is lower than the boiling point of the organic solvent, the organic solvent is also fully removed because the film is thin. In addition, it can be dried multiple times at different temperatures, and a variety of drying methods can also be used in combination.

[0724] (2) Specific examples of organic solvents

[0725] Examples of the organic solvent used in the composition for forming the organic layer include alkylbenzene-based solvents, phenyl ether-based solvents, alkyl ether-based solvents, cyclic ketone-based solvents, aliphatic ketone-based solvents, monocyclic ketone-based solvents, solvents having a diester skeleton, and fluorine-containing solvents. Specific examples include pentanol, hexanol, heptanol, octanol, nonanol, decanol, undecanol, dodecanol, tetradecanol, hexane-2-ol, heptane-2-ol, octane-2-ol, decane-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, tert-butylbenzene, 2-methylanisole, phenethyl ether, benzodioxole, 4-methylanisole, sec-butylbenzene, 3-methylanisole, 4-fluoro-3-methylanisole, cymene, 1,2,3-trimethylbenzene, 1,2-dichlorobenzene, 2-fluorobenzonitrile, 4-fluoro-o-dimethoxybenzene (4-fluoroveratrole), 2,6-dimethylanisole, n-butylbenzene, 3-fluorobenzonitrile, decalin (decahydronaphthalene), neopentylbenzene 、2,5-dimethylanisole, 2,4-dimethylanisole, benzonitrile, 3,5-dimethylanisole, diphenyl ether, 1-fluoro-3,5-dimethoxybenzene, methyl benzoate, isopentylbenzene, 3,4-dimethylanisole, o-tolunitrile, n-pentylbenzene, o-dimethoxybenzene (veratrole), 1,2,3,4-tetrahydronaphthalene, ethyl benzoate, n-hexylbenzene, propyl benzoate, cyclohexylbenzene, 1-methylnaphthalene, butyl benzoate, 2-methylbiphenyl, 3-phenoxytoluene, 2,2'-dimethylbiphenyl (2,2'-bitolyl), dodecylbenzene, dipentylbenzene, tetramethylbenzene, trimethoxybenzene, trimethoxytoluene, 2,3-dihydrobenzofuran, 1-methyl-4-(propoxymethyl)benzene, 1-methyl-4-(butoxymethyl)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, etc., but are not limited thereto. In addition, the solvent may be used alone or in combination.

[0726] <Optional ingredients>

[0727] The composition for forming an organic layer may contain an optional component within a range that does not impair its properties. Examples of the optional component include a binder and a surfactant.

[0728] (1) Adhesive

[0729] The composition for forming an organic layer may also contain a binder. The binder is used to bond the obtained film to the substrate while forming the film. In addition, it plays a role in dissolving, dispersing and bonding other components in the composition for forming an organic layer.

[0730] Examples of the binder used in the composition for forming an organic layer include acrylic resins, polyethylene terephthalate, ethylene-vinyl acetate copolymers, ethylene-vinyl alcohol copolymers, acrylonitrile-ethylene-styrene copolymers (AES) resins, ionomers, chlorinated polyethers, diallyl phthalate resins, unsaturated polyester resins, polyethylene, polypropylene, polyvinyl chloride, polyvinylidene chloride, polystyrene, polyvinyl acetate, Teflon, acrylonitrile-butadiene-styrene copolymers (ABS) resins, acrylonitrile-styrene copolymers (AS) resins, phenol resins, epoxy resins, melamine resins, urea resins, alkyd resins, polyurethanes, and copolymers of the above resins and polymers, but the present invention is not limited thereto.

[0731] The binder used in the composition for forming an organic layer may be used alone or in combination of two or more.

[0732] (2) Surfactants

[0733] For example, in order to control the uniformity of the film surface, the affinity of the solvent and the liquid repellency of the film surface of the organic layer forming composition, the organic layer forming composition may also contain a surfactant. Surfactants are classified into ionic and nonionic according to the structure of the hydrophilic group, and are further classified into alkyl, silicone and fluorine according to the structure of the hydrophobic group. In addition, according to the structure of the molecule, it is classified into a monomolecular system with a simple structure having a relatively small molecular weight and a polymer system with a side chain or branch having a large molecular weight. In addition, according to the composition, it is classified into a single system, a mixed system mixed with two or more surfactants and a substrate. As a surfactant that can be used for the organic layer forming composition, all types of surfactants can be used.

[0734] Examples of the surfactant include Polyflow No. 45, Polyflow KL-245, Polyflow No. 75, Polyflow No. 90, and Polyflow No. 95 (trade names, manufactured by Kyoeisha Chemical Industry Co., Ltd.); Disperbyk 161, Disperbyk 162, Disperbyk 163, and Disperbyk 164. 4. Disperbyk 166, Disperbyk 170, Disperbyk 180, Disperbyk 181, Disperbyk 182, BYK 300, BYK 306, BYK 310, BYK 320, BYK 330, BYK 342, BYK 344, BYK 346 (trade name, BYK-Chemie Japan); KP-341, KP-358, KP-368, KF-96-50CS, KF-50-100CS (trade names, Shin-Etsu Chemical Co., Ltd.); Surflon SC-101, Surflon KH-40 (trade names, Seimi Chemical Co., Ltd.); Ftergent 222F, Ftergent 251, FTX-218 (trade names, NEOS Co., Ltd.); EFTOP EF-351, EFTOP EF-352, EFTOP EF-601, EFTOP EF-801, EFTOP EF-802 (trade names, Mitsubishi Materials Co., Ltd. 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 names, manufactured by DIC Corporation);Fluoroalkylbenzenesulfonates, fluoroalkylcarboxylates, fluoroalkylpolyoxyethyleneethers, fluoroalkylammonium iodides, fluoroalkylbetaines, fluoroalkylsulfonates, diglyceroltetra(fluoroalkylpolyoxyethyleneethers), fluoroalkyltrimethylammonium salts, fluoroalkylaminosulfonates, polyoxyethylenenonylphenylether, polyoxyethyleneoctylphenylether, polyoxyethylenealkylethers, polyoxyethylenelaurate, polyoxyethyleneoleate, polyoxyethylenestearate, polyoxyethylenelaurylamine, sorbitanlaurate, sorbitanpalmitate, sorbitanstearate, sorbitanoleate, sorbitanfatty acid esters, polyoxyethylenesorbitanlaurate, polyoxyethylenesorbitanpalmitate, polyoxyethylenesorbitanstearate, polyoxyethylenesorbitanoleate, polyoxyethylenenaphthylether, alkylbenzenesulfonates and alkyldiphenyletherdisulfonates. ;

[0735] Furthermore, the surfactant may be used alone or in combination of two or more.

[0736] <Composition and physical properties of the organic layer-forming composition>

[0737] The content of each component in the organic layer-forming composition is determined from the viewpoints of good solubility, storage stability and film-forming property of each component in the organic layer-forming composition, high-quality film quality of the coating obtained from the organic layer-forming composition, good ejection property when using the inkjet method, good electrical properties, luminescent properties, efficiency and life of an organic EL element having an organic layer made using the composition. For example, in the case of a light-emitting layer-forming composition, it is preferred that the first component is 0.0001% to 2.0% by mass relative to the total mass of the light-emitting layer-forming composition, the second component is 0.0999% to 8.0% by mass relative to the total mass of the light-emitting layer-forming composition, and the third component is 90.0% to 99.9% by mass relative to the total mass of the light-emitting layer-forming composition.

[0738] More preferably, the first component is 0.005 mass % to 1.0 mass % relative to the total mass of the composition for forming a light-emitting layer, the second component is 0.095 mass % to 4.0 mass % relative to the total mass of the composition for forming a light-emitting layer, and the third component is 95.0 mass % to 99.9 mass % relative to the total mass of the composition for forming a light-emitting layer. Further preferably, the first component is 0.05 mass % to 0.5 mass % relative to the total mass of the composition for forming a light-emitting layer, the second component is 0.25 mass % to 2.5 mass % relative to the total mass of the composition for forming a light-emitting layer, and the third component is 97.0 mass % to 99.7 mass % relative to the total mass of the composition for forming a light-emitting layer.

[0739] The composition for forming an organic layer can be prepared by appropriately selecting the components and stirring, mixing, heating, cooling, dissolving, dispersing, etc. by known methods. In addition, filtering, degassing (also called degassing), ion exchange treatment, and inert gas replacement / sealing treatment can also be appropriately selected after preparation.

[0740] Regarding the viscosity of the composition for forming an organic layer, a high viscosity can obtain good film-forming properties and good ejection properties when using an inkjet method. On the other hand, a low viscosity makes it easy to make a thin film. Therefore, the viscosity of the composition for forming an organic layer is preferably 0.3 mPa·s to 3 mPa·s at 25°C, and more preferably 1 mPa·s to 3 mPa·s. In the present invention, the viscosity is a value measured using a cone-plate type rotational viscometer.

[0741] Regarding the surface tension of the composition for forming an organic layer, when the surface tension is low, good film forming properties and a defect-free coating film can be obtained. On the other hand, when the surface tension is high, good inkjet ejection properties can be obtained. Therefore, the surface tension of the composition for forming an organic layer at 25° C. is preferably 20 mN / m to 40 mN / m, and more preferably 20 mN / m to 30 mN / m. In the present invention, the surface tension is a value measured using a hanging drop method.

[0742] <Crosslinkable polymer compound: compound represented by formula (XLP-1)>

[0743] Next, the case where the 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).

[0744] [Chemistry 110]

[0745]

[0746] In formula (XLP-1),

[0747] MUx is independently a divalent group represented by removing any two hydrogen atoms from an aromatic compound, ECx is independently a monovalent group represented by removing any one hydrogen atom from an aromatic compound, two hydrogen atoms in MUx are substituted with ECx or MUx, and k is an integer of 2 to 50000. The compound represented by formula (XLP-1) has at least one crosslinking substituent (XLS), and preferably the content of the monovalent or divalent aromatic compound having a crosslinking substituent is 0.1 mass % to 80 mass % in the molecule.

[0748] More specifically,

[0749] MUx are each independently arylene, heteroarylene, diarylene arylamino, diarylene arylboryl, oxaalkyl boron-diyl, azaalkyl boron-diyl,

[0750] ECx are each independently hydrogen, aryl, heteroaryl, diarylamino, diheteroarylamino, arylheteroarylamino or aryloxy,

[0751] At least one hydrogen in MUx and ECx may be further substituted by an aryl group, a heteroaryl group, a diarylamino group, an alkyl group, or a cycloalkyl group, and k is an integer of 2 to 50,000.

[0752] k is preferably an integer of 20 to 50,000, more preferably an integer of 100 to 50,000.

[0753] At least one hydrogen in MUx and ECx in formula (XLP-1) may be substituted by an alkyl group having 1 to 24 carbon atoms, a cycloalkyl group having 3 to 24 carbon atoms, a halogen or a deuterium group, and further, any -CH2- in the alkyl group may be substituted by -O- or -Si(CH3)2-, any -CH2- in the alkyl group other than the -CH2- directly bonded to ECx in formula (XLP-1) may be substituted by an arylene group having 6 to 24 carbon atoms, and any hydrogen in the alkyl group may be substituted by fluorine.

[0754] Examples of MUx include a divalent group represented by removing arbitrary two hydrogen atoms from any of the following compounds.

[0755] [Chemistry 111]

[0756]

[0757] More specifically, the divalent group may be represented by any of the following structures: In these structures, MUx is bonded to other MUx or ECx at *.

[0758] [Chemistry 112]

[0759]

[0760] [Chemistry 113]

[0761]

[0762] [Chemistry 114]

[0763]

[0764] [Chemistry 115]

[0765]

[0766] [Chemistry 116]

[0767]

[0768] [Chemistry 117]

[0769]

[0770] [Chemistry 118]

[0771]

[0772] [Chemistry 119]

[0773]

[0774] [Chemistry 120]

[0775]

[0776] In addition, examples of ECx include monovalent groups represented by any of the following structures. In these structures, ECx is bonded to MUx at *.

[0777] [Chemistry 121]

[0778]

[0779] [Chemistry 122]

[0780]

[0781] From the viewpoint of solubility and coating film forming properties, the compound represented by formula (XLP-1) preferably has an alkyl group having 1 to 24 carbon atoms in 10% to 100% of the total number of MUx (k) in the molecule, more preferably has an alkyl group having 1 to 18 carbon atoms (branched alkyl group having 3 to 18 carbon atoms), and further preferably has an alkyl group having 1 to 12 carbon atoms (branched alkyl group having 3 to 12 carbon atoms) in 50% to 100% of the total number of MUx (k) in the molecule. On the other hand, from the viewpoint of in-plane orientation and charge transport, preferably has an alkyl group having 7 to 24 carbon atoms in 10% to 100% of the total number of MUx (k) in the molecule, and more preferably has an alkyl group having 7 to 24 carbon atoms (branched alkyl group having 7 to 24 carbon atoms) in 30% to 100% of the total number of MUx (k) in the molecule.

[0782] The content of the monovalent or divalent aromatic compound having a crosslinkable substituent is preferably 0.5% by mass to 50% by mass, more preferably 1% by mass to 20% by mass.

[0783] The crosslinkable substituent (XLS) is not particularly limited as long as it can further crosslink the polymer compound, but is preferably a substituent of the following structure: * in each structural formula represents a bonding position.

[0784] [Chemistry 123]

[0785]

[0786] L is independently a single bond, -O-, -S-, >C=O, -OC(=O)-, an alkylene group having 1 to 12 carbon atoms, an oxyalkylene group having 1 to 12 carbon atoms, and a polyoxyalkylene group having 1 to 12 carbon atoms. Among the substituents, a group represented by formula (XLS-1), formula (XLS-2), formula (XLS-3), formula (XLS-9), formula (XLS-10), or formula (XLS-17) is preferred, and a group represented by formula (XLS-1), formula (XLS-3), or formula (XLS-17) is more preferred.

[0787] Examples of the divalent aromatic compound having a crosslinkable substituent include compounds having the following partial structures: In the following structural formula, * represents a bonding position.

[0788] [Chemistry 124]

[0789]

[0790] [Chemistry 125]

[0791]

[0792] [Chemistry 126]

[0793]

[0794] [Chemistry 127]

[0795]

[0796] <Polymer compound and method for producing cross-linkable polymer compound>

[0797] The production methods of polymer compounds and crosslinkable polymer compounds will be described using the compound represented by the above formula (XLP-1) as an example. These compounds can be synthesized by appropriately combining known production methods.

[0798] Examples of the solvent used in the reaction include aromatic solvents, saturated / unsaturated hydrocarbon solvents, alcohol solvents, and ether solvents. Examples thereof include dimethoxyethane, 2-(2-methoxyethoxy)ethane, and 2-(2-ethoxyethoxy)ethane.

[0799] Alternatively, the reaction may be carried out in a two-phase system. In the case of carrying out the reaction in a two-phase system, a phase transfer catalyst such as a quaternary ammonium salt may be added as necessary.

[0800] When the compound of formula (XLP-1) is manufactured, it can be manufactured in one stage or in multiple stages. In addition, it can be carried out by a general polymerization method in which all the raw materials are placed in a reaction container and the reaction is started, it can also be carried out by a drop polymerization method in which the raw materials are added dropwise to the reaction container, and it can also be carried out by a precipitation polymerization method in which the product precipitates as the reaction proceeds. These methods can be appropriately combined for synthesis. For example, when the compound represented by formula (XLP-1) is synthesized in one stage, the target is obtained by reacting a monomer having a polymerizable group bonded to the monomer unit (MU) and a monomer having a polymerizable group bonded to the end-capping unit (EC) in a state where the monomer is added to the reaction container. In addition, when the compound represented by formula (XLP-1) is synthesized in multiple stages, the target is obtained by polymerizing the monomer having a polymerizable group bonded to the monomer unit (MU) to the target molecular weight, and then adding a monomer having a polymerizable group bonded to the end-capping unit (EC) and reacting. If different types of monomers having polymerizable groups bonded to monomer units (MU) are added in multiple stages for reaction, a polymer having a concentration gradient in the structure of the monomer units can be produced. In addition, after the precursor polymer is prepared, the target polymer can be obtained through subsequent reactions.

[0801] In addition, if the polymerizable group of the monomer unit (MU) is selected, the primary structure of the polymer can be controlled. For example, as shown in synthesis schemes 1 to 3, a polymer having a random primary structure (synthesis scheme 1), a polymer having a regular primary structure (synthesis schemes 2 and 3), etc. can be synthesized, and can be used in appropriate combinations according to the target. Furthermore, if a monomer having three or more polymerizable groups is used, a hyperbranched polymer or a dendrimer can be synthesized.

[0802] [Chemistry 128]

[0803]

[0804] The monomers that can be used in the present invention can be synthesized according to the methods described in Japanese Patent Laid-Open No. 2010-189630, International Publication No. 2012 / 086671, International Publication No. 2013 / 191088, International Publication No. 2002 / 045184, International Publication No. 2011 / 049241, International Publication No. 2013 / 146806, International Publication No. 2005 / 049546, International Publication No. 2015 / 145871, Japanese Patent Laid-Open No. 2010-215886, Japanese Patent Laid-Open No. 2008-106241, International Publication No. 2016 / 031639, and Japanese Patent Laid-Open No. 2011-174062.

[0805] In addition, for specific polymer synthesis procedures, reference can be made to the methods described in Japanese Patent Laid-Open No. 2012-036388, International Publication No. 2015 / 008851, Japanese Patent Laid-Open No. 2012-36381, Japanese Patent Laid-Open 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.

[0806] 2-1-9. Application examples of organic electroluminescent elements

[0807] The present invention can also be applied to a display device including an organic EL element, a lighting device including an organic EL element, or the like.

[0808] 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 of this embodiment to a known driving device, and can be driven using a known driving method such as DC driving, pulse driving, AC driving, etc. as appropriate.

[0809] As display devices, for example, panel displays such as color flat panel displays, flexible displays such as flexible color organic electroluminescent (EL) displays, etc. (for example, refer to Japanese Patent Laid-Open No. 10-335066, Japanese Patent Laid-Open No. 2003-321546, Japanese Patent Laid-Open No. 2004-281086, etc.). In addition, as display modes of displays, for example, matrix modes and segment modes can be listed. In addition, matrix display and segment display can coexist in the same panel.

[0810] In a matrix, pixels for display are arranged two-dimensionally in a grid or mosaic shape, etc., so that text or images are displayed by a collection of pixels. The shape or size of a pixel is determined according to the purpose. For example, in the image and text display of personal computers, monitors, and televisions, quadrilateral pixels with a side of less than 300 μm are usually used. In addition, in the case of large displays such as display screens, pixels with a side of mm are used. In the case of monochrome display, it is sufficient to arrange pixels of the same color. In the case of color display, red, green, and blue pixels are displayed in parallel. In the case, typical ones are triangular and stripe types. Moreover, as a driving method of the matrix, it can be either a line-sequential driving method or an active matrix. Line-sequential driving has the advantage of simple structure, but in the case of considering the operating characteristics, active matrix is ​​sometimes more excellent, so the driving method also needs to be used according to the purpose.

[0811] In the segmented method (type), a pattern is formed in a manner to display predetermined information, and the determined area is illuminated. Examples include: time or temperature display in a digital clock or thermometer, operating status display of audio equipment or induction cookers, and panel display of a car.

[0812] As lighting devices, for example, lighting devices such as indoor lighting, backlight sources of liquid crystal display devices, etc. can be listed (for example, refer to Japanese Patent Publication No. 2003-257621, Japanese Patent Publication No. 2003-277741, Japanese Patent Publication No. 2004-119211, etc.). Backlight sources are mainly used to improve the visibility of display devices that do not emit light by themselves, and are used for liquid crystal display devices, clocks, audio devices, automobile panels, display boards, and logos. In particular, as a backlight source for personal computers where thinning is becoming a problem in liquid crystal display devices, if it is considered that the existing methods are difficult to be thinned due to the inclusion of fluorescent lamps or light guide plates, the backlight source using the light-emitting element of this embodiment has the characteristics of being thin and lightweight.

[0813] 2-2. Other organic devices

[0814] The polycyclic aromatic compound of the present invention can be used not only in the organic electroluminescent element, but also in the preparation of organic field effect transistors or organic thin film solar cells.

[0815] An organic field effect transistor is a transistor that uses an electric field generated by voltage input to control current. In addition to a source electrode and a drain electrode, a gate electrode is also provided. An organic field effect transistor is a transistor in which an electric field is generated when a voltage is applied to the gate electrode, and the flow of electrons (or holes) flowing between the source electrode and the drain electrode can be arbitrarily blocked to control the current. Compared with a single transistor (bipolar transistor), a field effect transistor is easy to miniaturize and is often used as a component constituting an integrated circuit, etc.

[0816] Regarding the structure of an organic field effect transistor, generally, a source electrode and a drain electrode are provided in contact with an organic semiconductor active layer formed using the polycyclic aromatic compound of the present invention, and a gate electrode is provided via an insulating layer (dielectric layer) in contact with the organic semiconductor active layer. As an example of its element structure, the following structure can be cited.

[0817] (1) Substrate / gate electrode / insulator layer / source electrode, drain electrode / organic semiconductor active layer

[0818] (2) Substrate / gate electrode / insulator layer / organic semiconductor active layer / source electrode, drain electrode

[0819] (3) Substrate / organic semiconductor active layer / source electrode, drain electrode / insulator layer / gate electrode

[0820] (4) Substrate / source electrode, drain electrode / organic semiconductor active layer / insulator layer / gate electrode

[0821] The organic field effect transistor configured in this way can be used as a pixel driving switch element of an active matrix driving liquid crystal display or an organic electroluminescent display, etc.

[0822] Organic thin film solar cells have a structure in which an anode, a hole transport layer, a photoelectric conversion layer, an electron transport layer, and a cathode of ITO or the like are stacked on a transparent substrate such as glass. The photoelectric conversion layer has a p-type semiconductor layer on the anode side and an n-type semiconductor layer on the cathode side. The polycyclic aromatic compounds of the present invention can be used as materials for hole transport layers, p-type semiconductor layers, n-type semiconductor layers, and electron transport layers according to their physical properties. In organic thin film solar cells, the polycyclic aromatic compounds of the present invention can function as hole transport materials or electron transport materials. In addition to the above layers, organic thin film solar cells may also appropriately include a hole blocking layer, an electron blocking layer, an electron injection layer, a hole injection layer, a smoothing layer, and the like. In organic thin film solar cells, known materials used for organic thin film solar cells can be appropriately selected for use in combination.

[0823] 3. Wavelength conversion materials

[0824] The polycyclic aromatic compound of the present invention can be used as a wavelength conversion material. Currently, the application of multicolorization technology based on color conversion to liquid crystal displays or organic EL displays, lighting, etc. is being actively studied. The so-called color conversion is to convert the light emitted from the light source into light with a longer wavelength, for example, ultraviolet light or blue light is converted into green light or red light. The wavelength conversion material having the color conversion function is filmed, for example, combined with a blue light source, thereby being able to extract the three primary colors of blue, green, and red from the blue light source, that is, to extract white light. This white light source formed by combining the blue light source with the wavelength conversion film having the color conversion function is used as a light source unit, and combined with a liquid crystal drive part and a color filter, thereby being able to produce a full-color display. In addition, if there is no liquid crystal drive part, it can be directly used as a white light source, for example, it can be used as a white light source for light-emitting diode (LED) lighting, etc. In addition, a blue organic EL element is used as a light source, and is used in combination with a wavelength conversion film that converts blue light into green light and red light, thereby being able to produce a full-color organic EL display without using 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, a low-cost full-color micro LED display can be produced.

[0825] The polycyclic aromatic compound of the present invention can be used as the wavelength conversion material. The wavelength conversion material containing the polycyclic aromatic compound of the present invention can be used to convert ultraviolet light or light from a light source or light-emitting element that generates blue light with a shorter wavelength into blue light or green light with high color purity suitable for use in a display device (a display device or a liquid crystal display device using an organic EL element). The adjustment of the converted color can be carried out by appropriately selecting the substituent of the polycyclic aromatic compound of the present invention, the binder resin used in the wavelength conversion composition described later, etc. The wavelength conversion material is prepared as a wavelength conversion composition containing the polycyclic aromatic compound of the present invention. In addition, the wavelength conversion composition can also be used to form a wavelength conversion film.

[0826] The wavelength conversion composition may contain a binder resin, other additives, and a solvent in addition to the polycyclic aromatic compound of the present invention. As the binder resin, for example, the resins 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. As the solvent, the description of the solvent contained in the light-emitting layer forming composition may be referred to.

[0827] The wavelength conversion film includes a wavelength conversion layer formed by curing the wavelength conversion composition. As a method for making a wavelength conversion layer from a wavelength conversion composition, reference can be made to a known film formation method. The wavelength conversion film may include only a wavelength conversion layer formed by a composition comprising a 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). Furthermore, the wavelength conversion film may also include a substrate layer, or a barrier layer for preventing the color conversion layer from deteriorating due to oxygen, moisture, or heat.

[0828] [Example]

[0829] Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples.

[0830] Furthermore, in the examples, THF refers to tetrahydrofuran, IPA refers to isopropyl alcohol, and HPLC refers to high performance liquid chromatography.

[0831] <<Synthesis example>>

[0832] In "Science Advances" (9, eadh1434 (2023)), an organic lithium compound is added to a raw material into which a halogen is introduced at the boron introduction position, and after an exchange reaction between bromine and lithium is carried out, boron tribromide (BBr3) is further added to introduce boron, and finally mesityl magnesium bromide is added to obtain the target product.

[0833] In the following examples, a raw material into which a halogen is introduced at the boron introduction position or a raw material having a HOMO on the carbon at the boron introduction position is used, and boron tribromide (BBr3) and boron triiodide (BI3) are used as compounds of the boron source to introduce boron. As a result, a part undergoes cyclization, and a part becomes a boron halide (B-Br or BI). Subsequently, an organometallic compound such as a pre-prepared organolithium compound, a Grignard reagent, and an organozinc reagent is added to obtain the target product. In addition, in the following examples, a pre-prepared organolithium compound is added without separating the boron halide as a reaction intermediate, but it can also be added after the boron halide is separated and refined. In addition, according to the number of boron introduced, the amount of the compound to be added as a boron source and the amount of the organometallic compound added is changed. Specifically, when the number of boron introduced is 2, the equivalent is more than 2 times, when the number of boron introduced is 3, the equivalent is more than 3 times, when the number of boron introduced is 4, the equivalent is more than 4 times, when the number of boron introduced is 5, the equivalent is more than 5 times, and when the number of boron introduced is 6, the equivalent is more than 6 times.

[0834] In addition, in the following synthesis examples, mesityl magnesium bromide was used as a commercial product. In addition, in the following synthesis examples, m-terphenyl-2'-lithium, 2,4,6-tetraphenyl lithium, 2,6-carbazolylphenyl lithium, 2,6-bis(3,5-di-tert-butylphenyl) lithium, and 5-methyl-2,4,6-tetraphenyl lithium were synthesized from bromine by known methods.

[0835] Synthesis Example (1): Synthesis of Compound (1-1)

[0836] [Chemistry 129]

[0837]

[0838] [First process]

[0839] Under nitrogen atmosphere, 1.6M tert-butyl lithium pentane solution (40.0ml) was added to a flask containing compound (S-1-1) (10.0g) and tert-butylbenzene (150ml) at -30°C. After the addition was completed, the temperature was raised to 60°C and stirred for 2 hours, and the components with a boiling point lower than that of tert-butylbenzene were distilled off under reduced pressure. The mixture was cooled to -30°C and boron tribromide (17.5g) was added, and the temperature was raised to room temperature and stirred for 0.5 hours. After that, the mixture was cooled to 0°C again and N,N-diisopropylethylamine (12ml) was added, and the mixture was stirred at room temperature until the heat subsided, and then the temperature was raised to 120°C and heated and stirred for 3 hours. Subsequently, the reaction solution was cooled to 0°C, a tetrahydrofuran (THF) solution (200mL, 1.0M) of mesityl magnesium bromide was added, and the mixture was stirred at room temperature until the heat subsided, and then stirred at room temperature for 3 hours. The reaction solution was cooled to room temperature, and an aqueous sodium acetate solution cooled in an ice bath was added, followed by heptane for separation. Subsequently, the solution was purified by a silica gel short-path column (eluent: toluene), and the solid obtained by distilling off the solvent under reduced pressure was dissolved in toluene, and heptane was added to reprecipitate the solid to obtain compound (S-1-2) (1.05 g).

[0840] [Second step]

[0841] Palladium hydroxide (0.2 g) was added to a flask containing compound (S-1-2) (1.05 g), THF (16.0 ml) and IPA (8.0 ml), and palladium hydroxide was added as needed, while stirring at room temperature. After confirming the disappearance of the benzyl group by HPLC, the catalyst was filtered and the filtrate was concentrated.

[0842] The obtained crude product was dissolved in xylene (100 ml), 2-bromo-5-tert-butyl-benzoic acid (2.6 g), sodium tert-butoxide (4.1 g), Pd-132 (0.35 g) were added under nitrogen and heated to reflux for 5 hours. After the reaction mixture was cooled to room temperature, water was added to terminate the reaction. The layers were separated to extract the aqueous layer with toluene. The combined organic layer was washed with water and dried with anhydrous magnesium sulfate. The solution was concentrated under reduced pressure, and the residue was refined by silica gel chromatography (toluene) to obtain compound (S-1-3) (0.79 g).

[0843] [Third step]

[0844] Thionyl chloride (0.34 g) was added to a flask containing compound (S-1-3) (0.79 g) and toluene (10.0 ml) under nitrogen atmosphere at room temperature, and the temperature was raised to 110°C and heated under reflux for 8 hours. After cooling to room temperature, the volatile components were distilled off under reduced pressure to obtain an acid chloride. Dichloromethane (2.5 ml) was added to the flask containing the acid chloride, and aluminum chloride (0.4 g) was added at 0°C under nitrogen atmosphere, and the temperature was raised to room temperature and stirred for 24 hours. The reaction solution was added to dilute hydrochloric acid at 0°C to stop the reaction, extracted with dichloromethane, and the solvent was distilled off under reduced pressure. The crude product obtained was purified by column chromatography (eluent: toluene), and the solvent was distilled off under reduced pressure to obtain compound (1-1) (0.35 g).

[0845] Synthesis Example (2): Synthesis of Compound (3-1)

[0846] [Chemistry 130]

[0847]

[0848] [First process]

[0849] Under nitrogen atmosphere, 1.6M tert-butyl lithium pentane solution (36.0ml) was added to a flask containing compound (S-3-1) (10.0g) and tert-butylbenzene (200ml) at -30°C. After the addition was completed, the temperature was raised to 60°C and stirred for 2 hours, and the components with a boiling point lower than that of tert-butylbenzene were distilled off under reduced pressure. The mixture was cooled to -30°C and added with boron tribromide (15.0g), and the temperature was raised to room temperature and stirred for 0.5 hours. After that, the mixture was cooled to 0°C again and N,N-diisopropylethylamine (10.0ml) was added, and the mixture was stirred at room temperature until the heat subsided, and then the temperature was raised to 120°C and heated and stirred for 3 hours. Subsequently, the reaction solution was cooled to 0°C, a THF solution of mesityl magnesium bromide (200mL, 1.0M) was added, and the mixture was stirred at room temperature until the heat subsided, and then stirred at room temperature for 3 hours. The reaction solution was cooled to room temperature, and an aqueous sodium acetate solution cooled in an ice bath was added, followed by heptane for separation. Subsequently, the solution was purified by a silica gel short-path column (eluent: toluene), and the solid obtained by distilling off the solvent under reduced pressure was dissolved in toluene, and heptane was added to reprecipitate the solid to obtain compound (S-3-2) (0.98 g).

[0850] [Second step]

[0851] Palladium hydroxide (0.5 g) was added to a flask containing compound (S-3-2) (0.98 g), THF (20.0 ml) and IPA (10.0 ml), and palladium hydroxide was added as needed, while stirring at room temperature. After confirming the disappearance of the benzyl group by HPLC, the catalyst was filtered and the filtrate was concentrated.

[0852] The obtained crude product was dissolved in xylene (100 ml), 2-bromo-5-tert-butyl-benzoic acid (2.5 g), sodium tert-butoxide (4.0 g), Pd-132 (0.35 g) were added under nitrogen and heated to reflux for 5 hours. After the reaction mixture was cooled to room temperature, water was added to terminate the reaction. The layers were separated to extract the aqueous layer with toluene. The combined organic layer was washed with water and dried with anhydrous magnesium sulfate. The solution was concentrated under reduced pressure, and the residue was refined with silica gel chromatography (toluene) to obtain compound (S-3-3) (0.61 g).

[0853] [Third step]

[0854] Thionyl chloride (0.34 g) was added to a flask containing compound (S-3-3) (0.61 g) and toluene (10.0 ml) under nitrogen atmosphere at room temperature, and the temperature was raised to 110°C and heated under reflux for 8 hours. After cooling to room temperature, the volatile components were distilled off under reduced pressure to obtain an acid chloride. Dichloromethane (2.5 ml) was added to the flask containing the acid chloride, and aluminum chloride (0.6 g) was added under nitrogen atmosphere at 0°C, and the temperature was raised to room temperature and stirred for 24 hours. The reaction solution was added to dilute hydrochloric acid at 0°C to stop the reaction, extracted with dichloromethane, and the solvent was distilled off under reduced pressure. The crude product obtained was purified by column chromatography (eluent: toluene), and the solvent was distilled off under reduced pressure to obtain compound (3-1) (0.20 g).

[0855] The following compounds were synthesized by the method according to Synthesis Example (1) or by combining the methods according to Synthesis Example (1).

[0856] [Chemistry 131]

[0857]

[0858] [Chemistry 132]

[0859]

[0860] The following compounds were synthesized by the method according to Synthesis Example (2) or by combining the methods according to Synthesis Example (2).

[0861] [Chemistry 133]

[0862]

[0863] The formation of the target product was confirmed by MALDI-TOF-MS (matrix-assisted laser desorption ionization time-of-flight mass spectrometry).

[0864] [Table 1]

[0865] Compound No. M Compound (1-1) 798.49 Compound (1-2) 1040.60 Compound (1-3) 906.49 Compound (1-4) 844.42 Compound (1-5) 1058.55 Compound (1-6) 1344.91 Compound (1-7) 1126.50 Compound (1-8) 1151.61 Compound (1-9) 1108.76 Compound (1-10) 1073.56 Compound (1-11) 1186.59 Compound (1-12) 986.56 Compound (1-13) 1080.45 Compound (1-14) 1006.52 Compound (1-15) 1018.49 Compound (1-16) 1172.60 Compound (1-17) 1082.61 Compound (1-18) 1022.50 Compound (1-19) 1112.64 Compound (1-20) 830.46 Compound (3-1) 1000.47 Compound (3-2) 1026.48 Compound (3-3) 1082.41 Compound (3-4) 1157.46 Compound (3-5) 1267.48 Compound (3-6) 1134.39 Compound (3-7) 1075.32 Compound (3-8) 890.25 Compound (3-9) 1134.33 Compound (3-10) 932.30

[0866] The following comparative compounds were synthesized according to the method described in International Publication No. 2019 / 009052, Japanese Patent Application Laid-Open No. 2020-136675, or International Publication No. 2018 / 212169.

[0867] [Chemistry 134]

[0868]

[0869] [Chemistry 135]

[0870]

[0871] <<Manufacturing and evaluation of organic EL elements>>

[0872] Using the synthesized compounds of the present invention and comparative compounds, organic EL devices of TTF, TADF, TAF, and PSF were produced.

[0873] <TTF structure: Examples 1-1-1 to 1-1-20 and Comparative Examples 1-1-1 to 1-1-6>

[0874] ITO (120 nm) / HI (40 nm) / HAT-CN (5 nm) / HT-1 (45 nm) / HT-2 (10 nm) / BH: each compound listed in Table 2 (97: 3) (25 nm) / ET-1 (5 nm) / ET-2: Liq (1: 1) (25 nm) / LiF (1 nm) / Al (100 nm)

[0875] The chemical structures of the compounds used in the production of the element are shown below.

[0876] [Chemistry 136]

[0877]

[0878] A 26 mm × 28 mm × 0.7 mm glass substrate (manufactured by Opto Science Co., Ltd.) on which ITO film having a thickness of 180 nm formed by sputtering was polished to 120 nm was used as a transparent support substrate. The transparent support substrate was fixed on a substrate holder of a commercially available vapor deposition apparatus (manufactured by Showa Vacuum Co., Ltd.), and a molybdenum vapor deposition boat containing HI, HAT-CN, HT-1, HT-2, BH, each compound described in Table 2, ET-1 and ET-2, and an aluminum nitride vapor deposition boat containing Liq, LiF and aluminum were installed.

[0879] The following layers were formed in sequence on the ITO film of the transparent supporting substrate. The vacuum chamber was depressurized to 5×10 -4Pa, first, HI is heated and evaporated in a manner to make the film thickness 40nm, then HAT-CN is heated and evaporated in a manner to make the film thickness 5nm, then HT-1 is heated and evaporated in a manner to make the film thickness 45nm, then HT-2 is heated and evaporated in a manner to make the film thickness 10nm, to form a hole layer containing four layers. Then, BH and each compound described in Table 2 are heated simultaneously, and evaporated in a manner to make the film thickness 25nm to form a light-emitting layer. The evaporation speed is adjusted in a manner such that the mass ratio of BH to each compound described in Table 2 is approximately 97 to 3. Furthermore, ET-1 is heated and evaporated in a manner to make the film thickness 5nm, then ET-2 and Liq are heated simultaneously, and evaporated in a manner to make the film thickness 25nm to form an electronic layer containing two layers. The evaporation speed is adjusted in a manner such that the mass ratio of ET-2 to Liq is approximately 50 to 50. The deposition rate of each layer is 0.01 nm / sec to 1 nm / sec. Then, LiF is heated and vapor-deposited at a deposition rate of 0.01 nm / sec to 0.1 nm / sec so as to have a film thickness of 1 nm, and then aluminum is heated and vapor-deposited so as to have a film thickness of 100 nm to form a cathode, thereby obtaining an organic EL element.

[0880] <TADF structure: Examples 2-2-1 to 2-2-10 and Comparative Examples 2-2-1 to 2-2-5>

[0881] ITO (50nm) / HAT-CN (10nm) / HT-1 (60nm) / SiCzCz (5nm) / SiCzCz:SiTrzCz2:Compounds listed in Table 2 (60:39:1) (35nm) / mSiTrz (5nm) / mSiTrz:Liq (1:1) (30nm) / LiF (1nm) / Al (100nm)

[0882] A 26 mm × 28 mm × 0.7 mm glass substrate (manufactured by Opto Science Co., Ltd.) on which ITO film having a thickness of 200 nm was formed by sputtering and polished to 50 nm was used as a transparent support substrate. The transparent support substrate was fixed on a substrate holder of a commercially available vapor deposition apparatus (manufactured by Showa Vacuum Co., Ltd.), and a molybdenum vapor deposition boat containing HAT-CN, HT-1, SiCzCz, SiTrzCz2, each compound described in Table 2, mSiTrz and Liq, and a tungsten vapor deposition boat containing LiF and aluminum, respectively, were installed.

[0883] The following layers were formed in sequence on the ITO film of the transparent supporting substrate. The vacuum chamber was depressurized to 5×10-4 Pa, first, HAT-CN is heated and evaporated in a manner that the film thickness becomes 10nm to form a hole injection layer. Then, HT-1 is heated and evaporated in a manner that the film thickness becomes 60nm to form a hole transport layer 1, and then SiCzCz is heated and evaporated in a manner that the film thickness becomes 5nm to form a hole transport layer 2. Next, SiCzCz, SiTrzCz2 and each compound recorded in Table 2 are heated simultaneously, and evaporated in a manner that the film thickness becomes 35nm to form a light-emitting layer. The evaporation speed is adjusted in a manner that the mass ratio of SiCzCz, SiTrzCz2 and each compound recorded in Table 2 becomes approximately 60 to 39 to 1. Next, mSiTrz is heated and evaporated in a manner that the film thickness becomes 5nm to form an electron transport layer 1, and then mSiTrz and Liq are heated and evaporated in a manner that the film thickness becomes 30nm to form an electron transport layer 2. The evaporation rate is adjusted so that the mass ratio of SiTrz to Liq is approximately 1 to 1. The evaporation rate of each layer is 0.01 nm / sec to 1 nm / sec. Afterwards, LiF is heated and evaporated at a evaporation rate of 0.01 nm / sec to 0.1 nm / sec so that the film thickness becomes 1 nm, and then aluminum is heated and evaporated in a manner so that the film thickness becomes 100 nm to form a cathode, thereby obtaining an organic EL element. At this time, the evaporation rate of aluminum is adjusted to 1 nm / sec to 10 nm / sec. In addition, the SiCzCz of the light-emitting layer is equivalent to a hole-transporting main material, and the SiTrzCz2 is equivalent to an electron-transporting main material.

[0884] <TAF structure: Example 3-1-1 to Example 3-1-20, Comparative Example 3-1-1 to Comparative Example 3-1-6, Example 3-2-1 to Example 3-2-10, and Comparative Example 3-2-1 to Comparative Example 3-2-5>

[0885] ITO (50 nm) / HAT-CN (10 nm) / HT-1 (60 nm) / SiCzCz (5 nm) / SiCzCz: SiTrzCz2: TADF-1: each compound listed in Table 2 (60: 26: 13: 1) (35 nm) / mSiTrz (5 nm) / mSiTrz: Liq (1: 1) (30 nm) / LiF (1 nm) / Al (100 nm)

[0886] Except for the light-emitting layer, the structure was prepared in the same manner as the TADF structure. For the light-emitting layer, SiCzCz, SiTrzCz2, (TADF-1) and the compounds listed in Table 2 were heated simultaneously and evaporated to a film thickness of 35 nm. The evaporation rate was adjusted so that the mass ratio of SiCzCz, SiTrzCz2, (TADF-1) and the compounds listed in Table 2 was approximately 60:26:13:1.

[0887] <PSF structure: Example 4-1-1 to Example 4-1-20, Comparative Example 4-1-1 to Comparative Example 4-1-6, Example 4-2-1 to Example 4-2-10, and Comparative Example 4-2-1 to Comparative Example 4-2-5>

[0888] ITO (50nm) / HAT-CN (10nm) / HT-1 (60nm) / SiCzCz (5nm) / SiCzCz: SiTrzCz2: PtON7: Each compound listed in Table 2 (60:26:13:1) (35nm) / mSiTrz (5nm) / mSiTrz: Liq (1:1) (30nm) / LiF (1nm) / Al (100nm)

[0889] The TAF structure (TADF-1) was replaced with PtON7, and an element was produced in the same manner.

[0890] The chemical structures of the compounds used in the production of the above-mentioned elements are shown below.

[0891] [Chemistry 137]

[0892]

[0893] [evaluate]

[0894] Evaluation items include driving voltage (V), emission wavelength (nm), Commission Internationale de L'Eclairage (CIE) chromaticity (x, y), external quantum efficiency (%), maximum wavelength (nm) and half-value width (nm) of emission spectrum. These evaluation items can be measured using, for example, 1000 cd / m 2 The value when emitting light.

[0895] The quantum efficiency of a light-emitting element includes internal quantum efficiency and external quantum efficiency. The internal quantum efficiency indicates the proportion of external energy injected into the light-emitting layer of the light-emitting element as electrons (or holes) that is purely converted into photons. On the other hand, the external quantum efficiency is calculated based on the amount of photons released to the outside of the light-emitting element. A portion of the photons generated in the light-emitting layer are absorbed by the inside of the light-emitting element or continuously reflected without being released to the outside of the light-emitting element, so the external quantum efficiency is lower than the internal quantum efficiency.

[0896] The spectral radiance (luminescence spectrum) and external quantum efficiency were measured as follows. A voltage / current generator R6144 manufactured by Advantest was used to apply a voltage so that the device brightness reached 1000 cd / m 2 The element emits light by applying a voltage of . Using a spectroradiometer SR-3AR manufactured by TOPCON, the spectral radiance brightness in the visible light region is measured from a direction perpendicular to the light-emitting surface. Assuming that the light-emitting surface is a completely diffuse surface, the value of the spectral radiance brightness of each wavelength component measured is divided by the wavelength energy and multiplied by π to obtain the number of photons at each wavelength. Then, the number of photons is accumulated in the observed full wavelength region and set as the total number of photons released from the element. The value obtained by dividing the applied current value by the elementary charge is set as the number of carriers injected into the element, and the value obtained by dividing the total number of photons released from the element by the number of carriers injected into the element is the external quantum efficiency. In addition, the half-value width of the luminescence spectrum is calculated as the width between the upper and lower wavelengths where the maximum luminescence wavelength is set as the center and its intensity becomes 50%.

[0897] The ITO electrode was used as the anode and the LiF / aluminum electrode was used as the cathode. A DC voltage was applied and the 1000 cd / m 2 Characteristics during light emission. In addition, for the TTF structure element, the time (lifetime) to maintain a brightness of more than 95% of the initial brightness is measured, and for the TADF structure, TAF structure and PSF structure elements, the time (lifetime) to maintain a brightness of more than 50% of the initial brightness is measured. In addition, the light emission peaks of the elements are all in the range of 450nm to 470nm.

[0898] The results are shown in Table 2.

[0899] [Table 2]

[0900]

[0901]

[0902]

[0903] The obtained results show that the element of the embodiment has higher efficiency and longer life than the element of the comparative example having a corresponding skeleton.

[0904] <<Production and evaluation of coating-type organic EL elements>>

[0905] Next, an organic EL element obtained by forming an organic layer by coating will be described.

[0906] <Host polymer compound: Synthesis of SPH-101>

[0907] SPH-101 was synthesized according to the method described in International Publication No. 2015 / 008851. A copolymer in which M2 or M3 was bonded adjacent to M1 was obtained, and the molar ratio of each unit was estimated to be 50:26:24 based on the input ratio. In the following structural formula, Bpin is a pinacol boron group, and * is the linking site of each unit.

[0908] [Chemistry 138]

[0909]

[0910] <Polymer hole transport compound: Synthesis of XLP-101>

[0911] XLP-101 was synthesized according to the method described in Japanese Patent Publication No. 2018-61028. A copolymer in which M5 or M6 was bonded adjacent to M4 was obtained, and the molar ratio of each unit was estimated to be 40:10:50 based on the input ratio. Bpin is a pinacol boron group, and * is the linking site of each unit.

[0912] [Chemistry 139]

[0913]

[0914] <Example 5-1 to Example 5-9>

[0915] A coating solution of a material for forming each layer was prepared to produce a coating type organic EL device. <Production of organic EL devices of Examples 5-1 to 5-3>

[0916] Table 3 shows the material structure of each layer in the organic EL element.

[0917] [Table 3]

[0918]

[0919] The structure of "ET1" in Table 3 is shown below.

[0920] [Chemistry 140]

[0921]

[0922] <Preparation of the light-emitting layer-forming composition (1)>

[0923] The following components were stirred until a uniform solution was obtained to prepare a composition for forming a light-emitting layer (1). The prepared composition for forming a light-emitting layer was spin-coated on a glass substrate and dried by heating under reduced pressure to obtain a coating film having no film defects and excellent smoothness.

[0924]

[0925] In addition, compound (A) is a polycyclic aromatic compound (e.g., compound (1-1)) containing a structural unit represented by formula (1), a polymer compound obtained by polymerizing the polycyclic aromatic compound as a monomer (i.e., the monomer has a reactive substituent), or a polymer crosslinked product obtained by further crosslinking the polymer compound. The polymer compound used to obtain the polymer crosslinked product has a crosslinking substituent.

[0926] <PEDOT:PSS solution>

[0927] A commercially available PEDOT:PSS solution (Clevios (TM) P VP AI4083, an aqueous dispersion of PEDOT:PSS, manufactured by Heraeus Holdings) was used.

[0928] [Chemistry 141]

[0929]

[0930] <Preparation of OTPD solution>

[0931] OTPD (LT-N159, manufactured by Luminescence Technology Corp.) and IK-2 (photocationic polymerization initiator, manufactured by Sanapro Co., Ltd.) were dissolved in toluene to prepare an OTPD solution having an OTPD concentration of 0.7% by mass and an IK-2 concentration of 0.007% by mass.

[0932] [Chemistry 142]

[0933]

[0934] <Preparation of XLP-101 solution>

[0935] XLP-101 was dissolved in xylene at a concentration of 0.6 mass % to prepare a 0.6 mass % XLP-101 solution.

[0936] <Preparation of PCz solution>

[0937] PCz (polyvinyl carbazole) was dissolved in dichlorobenzene to prepare a 0.7 mass % PCz solution.

[0938] [Chemistry 143]

[0939]

[0940] <Example 5-1>

[0941] On a glass substrate with 150 nm thick ITO deposited, a PEDOT:PSS solution was spin-coated and calcined on a hot plate at 200°C for 1 hour to form a 40 nm thick PEDOT:PSS film (hole injection layer). Subsequently, an OTPD solution was spin-coated and dried on a hot plate at 80°C for 10 minutes, and then exposed to light with an exposure intensity of 100 mJ / cm 2 The film was exposed and baked on a hot plate at 100°C for 1 hour to form a 30 nm thick OTPD film (hole transport layer) that was insoluble in the solution. Next, the composition for forming a light-emitting layer (1) was spin-coated and baked on a hot plate at 120°C for 1 hour to form a light-emitting layer with a thickness of 20 nm.

[0942] The produced multilayer film was fixed on the substrate holder of a commercially available vapor deposition apparatus (manufactured by Showa Vacuum Co., Ltd.), and a molybdenum vapor deposition boat containing ET1, a molybdenum vapor deposition boat containing LiF, and a tungsten vapor deposition boat containing aluminum were installed. The vacuum tank was depressurized to 5×10 -4 Pa, ET1 is heated and evaporated in a manner to a film thickness of 30nm to form an electron transport layer. The evaporation rate when forming the electron transport layer is set to 1nm / second. Thereafter, LiF is heated and evaporated at an evaporation rate of 0.01nm / second to 0.1nm / second in a manner to a film thickness of 1nm. Subsequently, aluminum is heated and evaporated in a manner to a film thickness of 100nm to form a cathode. In this way, an organic EL element is obtained.

[0943] <Example 5-2>

[0944] An organic EL device was obtained by the same method as in Example 5-1. In addition, as for the hole transport layer, the XLP-101 solution was spin-coated and baked on a hot plate at 200° C. for 1 hour to form a film with a film thickness of 30 nm.

[0945] <Example 5-3>

[0946] An organic EL device was obtained by the same method as in Example 5-1. In addition, as for the hole transport layer, a PCz solution was spin-coated and baked on a hot plate at 120° C. for 1 hour to form a film with a film thickness of 30 nm.

[0947] <Evaluation of organic EL elements of Examples 5-1 to 5-3>

[0948] It is expected that the coating-type organic EL element obtained as described above also has excellent driving voltage and external quantum efficiency, similar to the vapor deposition-type organic EL element.

[0949] <Production of organic EL elements of Examples 5-4 to 5-6>

[0950] Table 4 shows the material structure of each layer in the organic EL element.

[0951] [Table 4]

[0952]

[0953] <Preparation of the composition for forming a light-emitting layer (2) to (4)>

[0954] The following components were stirred until a uniform solution was obtained, thereby preparing a composition (2) for forming a light-emitting layer.

[0955]

[0956] The following components were stirred until a uniform solution was obtained, thereby preparing a composition (3) for forming a light-emitting layer.

[0957]

[0958] The following components were stirred until a uniform solution was obtained, thereby preparing a composition (4) for forming a light-emitting layer.

[0959]

[0960] In Table 4, "mCBP" is 3,3'-bis(N-carbazolyl)-1,1'-biphenyl, "DOBNA" is 3,11-di-o-tolyl-5,9-dioxa-13b-boranaphtho[3,2,1-de]anthracene, and "TSPO1" is diphenyl[4-(triphenylsilyl)phenyl]phosphine oxide. The chemical structures are shown below.

[0961] [Chemistry 144]

[0962]

[0963] <Example 5-4>

[0964] On the glass substrate on which a 45 nm thick ITO film was formed, a ND-3202 solution (manufactured by Nissan Chemical Industries) was spin-coated, and then heated at 50° C. for 3 minutes and further at 230° C. for 15 minutes in an air environment to form a 50 nm thick ND-3202 film (hole injection layer). Subsequently, an XLP-101 solution was spin-coated, and then heated at 200° C. for 30 minutes on a hot plate in a nitrogen environment to form a 20 nm thick XLP-101 film (hole transport layer). Subsequently, a light-emitting layer-forming composition (2) was spin-coated, and then heated at 130° C. for 10 minutes in a nitrogen environment to form a 20 nm thick light-emitting layer.

[0965] The produced multilayer film was fixed on the substrate holder of a commercially available vapor deposition apparatus (manufactured by Showa Vacuum Co., Ltd.), and a molybdenum vapor deposition boat containing TSPO1, a molybdenum vapor deposition boat containing LiF, and a tungsten vapor deposition boat containing aluminum were installed. The vacuum tank was depressurized to 5×10 -4 Pa, TSPO1 is heated and evaporated in a manner to a film thickness of 30nm to form an electron transport layer. The evaporation rate when forming the electron transport layer is set to 1nm / second. Thereafter, LiF is heated and evaporated at an evaporation rate of 0.01nm / second to 0.1nm / second in a manner to a film thickness of 1nm. Subsequently, aluminum is heated and evaporated in a manner to a film thickness of 100nm to form a cathode. In this way, an organic EL element is obtained.

[0966] <Example 5-5 and Example 5-6>

[0967] An organic EL device was obtained by the same method as in Example 5-4 using the composition for forming a light-emitting layer (3) or the composition for forming a light-emitting layer (4).

[0968] <Evaluation of organic EL elements of Examples 5-4 to 5-6>

[0969] It is expected that the coating-type organic EL element obtained as described above also has excellent driving voltage and external quantum efficiency, similar to the vapor deposition-type organic EL element.

[0970] <Production of organic EL devices of Examples 5-7 to 5-9>

[0971] Table 5 shows the material structure of each layer in the organic EL element.

[0972] [Table 5]

[0973]

[0974] <Preparation of the composition for forming a light-emitting layer (5) to (7)>

[0975] The following components were stirred until a uniform solution was obtained, thereby preparing a composition (5) for forming a light-emitting layer.

[0976]

[0977] The following components were stirred until a uniform solution was obtained, thereby preparing a composition (6) for forming a light-emitting layer.

[0978]

[0979] The following components were stirred until a uniform solution was obtained, thereby preparing a composition (7) for forming a light-emitting layer.

[0980]

[0981] In Table 5, "2PXZ-TAZ" is 10,10'-((4-phenyl-4H-1,2,4-triazole-3,5-diyl)bis(4,1-phenylene))bis(10H-phenoxazine). The chemical structure is shown below.

[0982] [Chemistry 145]

[0983]

[0984] <Example 5-7>

[0985] On a glass substrate on which a 45 nm thick ITO film was formed, a ND-3202 solution (manufactured by Nissan Chemical Industries) was spin-coated, and then heated at 50°C for 3 minutes and further at 230°C for 15 minutes in an air environment to form a 50 nm thick ND-3202 film (hole injection layer). Subsequently, an XLP-101 solution was spin-coated, and then heated at 200°C on a hot plate for 30 minutes in a nitrogen environment to form a 20 nm thick XLP-101 film (hole transport layer). Subsequently, a light-emitting layer-forming composition (5) was spin-coated, and then heated at 130°C for 10 minutes in a nitrogen environment to form a 20 nm thick light-emitting layer.

[0986] The produced multilayer film was fixed on the substrate holder of a commercially available vapor deposition apparatus (manufactured by Showa Vacuum Co., Ltd.), and a molybdenum vapor deposition boat containing TSPO1, a molybdenum vapor deposition boat containing LiF, and a tungsten vapor deposition boat containing aluminum were installed. The vacuum tank was depressurized to 5×10 -4Pa, TSPO1 is heated and evaporated in a manner to a film thickness of 30nm to form an electron transport layer. The evaporation rate when forming the electron transport layer is set to 1nm / second. Thereafter, LiF is heated and evaporated at an evaporation rate of 0.01nm / second to 0.1nm / second in a manner to a film thickness of 1nm. Subsequently, aluminum is heated and evaporated in a manner to a film thickness of 100nm to form a cathode. In this way, an organic EL element is obtained.

[0987] <Example 5-8 and Example 5-9>

[0988] An organic EL device was obtained by the same method as in Example 5-7 using the composition for forming a light-emitting layer (6) or the composition for forming a light-emitting layer (7).

[0989] <Evaluation of organic EL elements of Examples 5-7 to 5-9>

[0990] It is expected that the coating-type organic EL element obtained as described above also has excellent driving voltage and external quantum efficiency, similar to the vapor deposition-type organic EL element.

Claims

1. A polycyclic aromatic compound having the following structure, wherein the structure is composed of one or more structural units represented by formula (1), and contains at least one group represented by the formula (X1) and at least one group represented by the formula (X3) as X, or Containing at least one group represented by formula (X13) as X; [Chemistry 1] In formula (1), Ring A, Ring B, and Ring C are each independently a substituted or unsubstituted aryl ring or a substituted or unsubstituted heteroaryl ring; Y is >B-, >P-, >P(=O)-, >P(=S)-, >Al-, >Ga-, >As-, >Si(-R IY )-or>Ge(-R GY )-, R IY and R GY are each independently a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted alkyl, or a substituted or unsubstituted cycloalkyl; In each of formula (X1) and formula (X13), Ring D is a substituted or unsubstituted aryl ring or a substituted or unsubstituted heteroaryl ring, In each of formula (X1) and formula (X13), R bz are each independently hydrogen, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted alkyl, or substituted or unsubstituted cycloalkyl, In each of formula (X3) and formula (X13), X D is >C=O, >C=S, >S=O, >S(=O)2, or >P=O, The position of the wavy line in the radical represented by each of Formula (X1), Formula (X3), and Formula (X13) is the bonding position of X to the A ring and the B ring, or the bonding position of X to the A ring and the C ring, The group represented by formula (X1) is bonded at # to any ring to which the group represented by formula (X1) is bonded, and in the one ring, the bonding position of the group represented by formula (X1) at a wavy line and the bonding position at # are adjacent to each other, In formula (X1), ring D can be bonded to the base L D The other ring to which the group represented by formula (X1) is bonded is further bonded, and its bonding position is adjacent to the bonding position of the group represented by formula (X1) in the other ring at a wavy line, L D are independently single bonds, >BR BL 、>NR NL 、>O、>S、>C(-R CL )2、>Si(-R IL )2 or >Se, R BL , R NL , R CL and R IL are each independently hydrogen, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted alkyl, or substituted or unsubstituted cycloalkyl, and the two R CL Can bond to each other to form a ring, two R IL Can bond to each other to form a ring, R NL , R CL and R IL may be independently bonded to at least one of the A ring, the B ring, and the C ring via a linking group or a single bond; In formula (X3), ring G is a substituted or unsubstituted aryl ring or a substituted or unsubstituted heteroaryl ring, The group represented by formula (X3) is bonded at ## to any ring to which the group represented by formula (X3) is bonded, and in the one ring, the bonding position of the group represented by formula (X3) at a wavy line and the bonding position at ## are adjacent to each other, G ring can be linked to the base L G The other ring to which the base represented by formula (X3) is bonded is further bonded, and its bonding position is adjacent to the bonding position of the base represented by formula (X3) in the other ring at a wavy line, L G With L D have the same meaning; The group represented by formula (X13) is bonded to any ring to which the group represented by formula (X13) is bonded at #, and in the one ring, the bonding position of the group represented by formula (X13) at a wavy line and the bonding position at # are adjacent to each other, and it is bonded to another ring to which the group represented by formula (X13) is bonded at ##, and in the other ring, the bonding position of the group represented by formula (X13) at a wavy line and the bonding position at ## are adjacent to each other; Each of the other Xs other than the group represented by formula (X1), formula (X3), or formula (X13) is independently a group represented by formula (X2), >N-Ar X 、>NR NX 、>O、>C(-R CX )2、>Si(-R IX )2,>S, or>Se,Ar X is a substituted or unsubstituted aryl group or a substituted or unsubstituted heteroaryl group, R NX is hydrogen, substituted or unsubstituted alkyl, or substituted or unsubstituted cycloalkyl, R CX and R IX are each independently hydrogen, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted alkyl, or substituted or unsubstituted cycloalkyl, and the two R CX Can bond to each other to form a ring, two R IX Can bond with each other to form a ring, R NX , R CX and R IX can be connected to the R NX , the R CX , or the R IX One or two bonds of the ring to which X is bonded, [Chemistry 2] In formula (X2), Ring F is a substituted or unsubstituted aryl ring or a substituted or unsubstituted heteroaryl ring, L F are independently a single bond, >NR NL 、>O、>S、>C(-R CL )2、>Si(-R IL )2 or >Se, R NL , R CL and R IL are each independently hydrogen, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted alkyl, or substituted or unsubstituted cycloalkyl, and the two R CL Can bond to each other to form a ring, two R IL Can bond to each other to form a ring, R NL , R CL and R IL may be independently bonded to at least one of the A ring, the B ring, and the C ring via a linking group or a single bond; The position of the wavy line in the group represented by formula (X2) is the bonding position of X to the A ring and the B ring, or the bonding position of X to the A ring and the C ring, The group represented by formula (X2) is bonded at * to any ring to which the group represented by formula (X2) is bonded, and in the one ring, the bonding position of the group represented by formula (X2) at a wavy line and the bonding position at * are adjacent to each other, The F ring can be bonded to the L F2 The other ring to which the group represented by formula (X2) is bonded is further bonded, and its bonding position is adjacent to the bonding position of the group represented by formula (X2) in the other ring at a wavy line, L F2 With L F For the same meaning, At least one of the aryl rings and heteroaryl rings 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-, In the structure, at least one hydrogen may be replaced by deuterium, and at least one nitrogen may be replaced by nitrogen-15( 15 N) substituted, at least one sulfur may be replaced by sulfur-33( 33 S), sulfur-34 ( 34 S) or sulfur-36( 36 S), at least one oxygen may be replaced by oxygen-17( 17 O) or oxygen-18 ( 18 O) substituted, at least one carbon may be substituted by carbon-13 ( 13 C) substituted, at least one boron may be substituted by boron-11( 11 B) Replacement.

2. The polycyclic aromatic compound according to claim 1, wherein X D It is >C=O or >C=S. 3 . The polycyclic aromatic compound according to claim 1 , comprising at least one group represented by formula (X13) as X.

4. The polycyclic aromatic compound according to claim 1, comprising at least one D The group represented by the formula (X1) further bonded to another ring to which the group represented by the formula (X1) is bonded is X.

5. The polycyclic aromatic compound according to claim 1, comprising at least one phenyl group as R bz , the phenyl group has substituents at at least two ortho positions, and the two substituents are independently substituted or unsubstituted aryl groups or substituted or unsubstituted heteroaryl groups. 6 . The polycyclic aromatic compound according to claim 1 , which is composed of one of the structural units represented by formula (1).

7. The polycyclic aromatic compound according to claim 6, which is represented by any of the following formulas: [Chemistry 3] [Chemistry 4] In the formula, Me is a methyl group, tBu is a tert-butyl group, and Ad is a 1-adamantyl group.

8. The polycyclic aromatic compound according to claim 1, which is represented by formula (1M2-1) and contains at least one group represented by formula (X1) and at least one group represented by formula (X3) as X, or contains at least one group represented by formula (X13) as X; [Chemistry 5] In formula (1M2-1), Ring A, Ring B, Ring C, Y, and X have the same meanings as Ring A, Ring B, Ring C, Y, and X in Formula (1), respectively; Ring B' is independently a substituted or unsubstituted aryl ring or a substituted or unsubstituted heteroaryl ring, At least one of the aryl rings and heteroaryl rings 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-, In the structure, at least one hydrogen may be replaced by deuterium, and at least one nitrogen may be replaced by nitrogen-15( 15 N) substituted, at least one sulfur may be replaced by sulfur-33( 33 S), sulfur-34 ( 34 S) or sulfur-36( 36 S), at least one oxygen may be replaced by oxygen-17( 17 O) or oxygen-18 ( 18 O) substituted, at least one carbon may be substituted by carbon-13 ( 13 C) substituted, at least one boron may be substituted by boron-11( 11 B) Replacement.

9. The polycyclic aromatic compound according to claim 8, which is represented by any of the following formulas: [Chemistry 6] In the formula, Me is a methyl group and tBu is a tert-butyl group.

10. A polymer compound obtained by polymerizing a reactive compound having a reactive substituent substituted in the polycyclic aromatic compound according to claim 1 as a monomer, wherein the polymer compound has a number average molecular weight of 2000 to 1.0×10 8 . 11 . A material for an organic device, comprising the polycyclic aromatic compound according to claim 1 or the polymer compound according to claim 10 . 12 . The material for an organic device according to claim 11 , wherein the material for an organic device is a material for an organic electroluminescent element, a material for an organic field effect transistor, a material for an organic thin film solar cell, or a material for a wavelength conversion filter. 13 . An organic electroluminescent element comprising: a pair of electrodes including an anode and a cathode; and an organic layer disposed between the pair of electrodes, the organic layer comprising the polycyclic aromatic compound according to claim 1 or the polymer compound according to claim 10 . The organic electroluminescent element according to claim 13 , wherein the organic layer is a light-emitting layer.

15. A display device or a lighting device, comprising the organic electroluminescent element according to claim 13.

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