KR20230098036A - Polycyclic aromatic compound - Google Patents

Abstract

(A환, B환, 및 C환 중 적어도 하나는, 적어도 식(1R)으로 나타내어지는 기로 치환되어 있는 아릴환 또는 헤테로아릴환이며, 그 밖에는 치환 또는 무치환의 아릴환 또는 헤테로아릴환이고, F환, G환 및 H환은 치환 또는 무치환의 아릴환이며, Y는 >B-이고, X는 >N-R^X(R^X는 아릴), >O, 또는 >S이며, 상기 구조에 있어서의 아릴환 및 헤테로아릴환으로 이루어지는 군에서 선택되는 적어도 하나는 적어도 하나의 시클로알칸으로 축합되어 있어도 되고, 상기 구조에 있어서의 적어도 하나의 수소는, 중수소, 시아노, 또는 할로겐으로 치환되어 있어도 됨.) [Problem] To provide a novel compound useful as a material for organic devices such as an organic EL device.
[Solution] A polycyclic aromatic compound having a structure composed of one or two or more structural units represented by the following formula (1).

(At least one of the A ring, the B ring, and the C ring is an aryl ring or heteroaryl ring substituted with at least a group represented by formula (1R), and the others are a substituted or unsubstituted aryl ring or heteroaryl ring, F ring, G ring and H ring are substituted or unsubstituted aryl rings, Y is >B-, X is >NR ^X (R ^X is aryl), >O, or >S, and aryl in the above structure At least one selected from the group consisting of a ring and a heteroaryl ring may be condensed with at least one cycloalkane, and at least one hydrogen in the above structure may be substituted with deuterium, cyano or halogen.)

Description

Polycyclic aromatic compound {POLYCYCLIC AROMATIC COMPOUND}

The present invention relates to polycyclic aromatic compounds. The present invention also relates to organic devices such as an organic electroluminescent element, an organic field effect transistor, and an organic thin-film solar cell using the polycyclic aromatic compound, and a display device and a lighting device.

Conventionally, display devices using electroluminescent light emitting elements can be reduced in power and reduced in thickness, so various researches have been conducted, and organic electroluminescent elements made of organic materials have been actively studied because they are easy to reduce in weight and increase in size. In particular, for the development of organic materials having luminescent properties such as blue, which is one of the three primary colors of light, and the development of organic materials equipped with charge transport capabilities (possibly becoming semiconductors or superconductors) such as holes and electrons, polymer compounds , regardless of low molecular weight compounds, have been actively studied so far.

An organic electroluminescent element has a structure composed of a pair of electrodes composed of an anode and a cathode, and one layer or a plurality of layers disposed between the pair of electrodes and containing an organic compound. Layers containing organic compounds include a light emitting layer and a charge transport/injection layer that transports or injects charges such as holes and electrons, and various organic materials suitable for these layers have been developed.

Among them, Patent Literature 1 discloses that a boron-containing polycyclic aromatic compound is useful as a material for an organic electroluminescent device or the like. It has been reported that an organic electroluminescent device containing this polycyclic aromatic compound has good external quantum efficiency.

Patent Document 1: International Publication No. 2015/102118

As described above, although various materials have been developed as materials used for organic EL devices, development of materials composed of compounds different from those of the prior art is expected in order to increase the options of materials for organic EL devices.

An object of the present invention is to provide a useful novel compound as a material for organic devices such as an organic EL element.

The inventors of the present invention conducted intensive studies to solve the above problems, and succeeded in producing a novel polycyclic aromatic compound having more excellent light emitting properties in a polycyclic aromatic compound containing boron similarly to the compound described in Patent Literature 1. Furthermore, they found that an excellent organic EL device can be obtained by disposing a layer containing this polycyclic aromatic compound between a pair of electrodes to constitute an organic EL device, and completed the present invention. That is, the present invention provides a polycyclic aromatic compound as described below, a material for an organic device containing the polycyclic aromatic compound as described below, and the like.

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

In formula (1),

A ring, B ring, and C ring are each independently a substituted or unsubstituted aryl ring or a substituted or unsubstituted heteroaryl ring, provided that at least one selected from the group consisting of A ring, B ring, and C ring is an aryl ring substituted with a group represented by formula (1R) or a heteroaryl ring substituted with a group represented by formula (1R),

In formula (1R), ring F, ring G, and ring H are each independently a substituted or unsubstituted aryl ring or a substituted or unsubstituted heteroaryl ring, * is a bonding position,

Y is >B-, >P-, >P(=O)-, >P(=S)-, >Al-, >Ga-, >As-, >C(-R ^Y )-, >Si( -R ^Y )-, or >Ge(-R ^Y )-, and R ^Y each independently represents optionally substituted aryl, optionally substituted heteroaryl, optionally substituted alkyl, or optionally substituted cyclo is an alkyl,

X is each independently >NR ^X , >O, >S, >C(-R ^X ) ₂ , >Si(-R ^X ) ₂ , or >Se, and R ^X is each independently hydrogen, substituted optionally substituted aryl, optionally substituted heteroaryl, optionally substituted alkyl, or optionally substituted cycloalkyl, >C(-R ^X ) ₂ of two R ^X and >Si(-R ^X ) ₂ of Two R ^X 's may be bonded by a single bond or a linking group, respectively;

R ^X in X may be bonded to one or two selected from the group consisting of A ring, B ring, and C ring by a single bond or a linking group;

In the above structure, at least one selected from the group consisting of an aryl ring and a heteroaryl ring may be condensed with at least one cycloalkane, and the cycloalkane may be substituted with at least one substituent, and the cycloalkane At least one -CH ₂ - in may be substituted with -O-,

At least one hydrogen in the above structure may be substituted with heavy hydrogen, cyano or halogen.

<2> A substituent other than the group represented by formula (1R) as a substituent when A ring, B ring, C ring, F ring, G ring, and H ring is a substituted aryl ring or substituted heteroaryl ring is substituent group Z And at least one substituent selected from the group consisting of a substituent represented by formula (A30),

Substituent group Z is,

aryl which may be substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl and cycloalkyl;

heteroaryl which may be substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl and cycloalkyl;

diarylamino which may be substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl and cycloalkyl (two aryls may be bonded to each other via a linking group);

diheteroarylamino which may be substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl and cycloalkyl (two heteroaryls may be bonded to each other through a linking group);

arylheteroarylamino which may be substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl and cycloalkyl (aryl and heteroaryl may be bonded to each other through a linking group);

diarylboryl which may be substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl and cycloalkyl (two aryls may be bonded via a single bond or a linking group);

alkyl which may be substituted with at least one group selected from the group consisting of aryl, heteroaryl and cycloalkyl;

cycloalkyl which may be substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl and cycloalkyl;

alkoxy which may be substituted with at least one group selected from the group consisting of aryl, heteroaryl and cycloalkyl;

aryloxy which may be substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl and cycloalkyl; and

Consists of substituted silyl,

In formula (A30),

Ak is hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted cycloalkyl, or substituted or unsubstituted cycloalkenyl, and the corresponding alkyl, alkenyl, cycloalkyl and cycloalkenyl At least one -CH ₂ - in may be substituted with -O- or -S-;

R ^Ak is a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted alkyl, or a substituted or unsubstituted cycloalkyl, and R ^Ak is bonded to Ak by a linking group or a single bond. And, * is a bonding position,

The polycyclic aromatic compound according to <1>.

<3> The polycyclic aromatic compound according to <1> or <2>, wherein the group represented by formula (1R) is a group represented by formula (2R);

In formula (2R),

R ^AZ is each independently hydrogen, any substituent selected from substituent group Z, or a substituent represented by formula (A30), together with the ring to which adjacent R ^AZ is bonded to which they are directly bonded, an aryl ring or A heteroaryl ring may be formed, and the formed ring may be substituted with at least one substituent selected from the group consisting of substituent group Z and a substituent represented by formula (A30).

<4> The polycyclic aromatic compound according to <3>, wherein all of R ^AZ are hydrogen.

<5> Formula (2A), Formula (2B), Formula (2C), Formula (2D), Formula (2E), Formula (2F), Formula (2G), Formula (2H), Formula (2I), Formula ( 2J) or the polycyclic aromatic compound according to any one of <1> to <4> represented by formula (2K).

In the above formula,

R ^Z is each independently hydrogen, any substituent selected from substituent group Z, or a substituent represented by formula (A30), together with the ring to which adjacent R ^Z are bonded to which they are directly bonded, an aryl ring or hetero An aryl ring may be formed, and the formed ring may be substituted with at least one substituent ^RZ2 selected from the group consisting of substituent group Z and a substituent represented by formula (A30),

However, in each formula, at least one selected from the group consisting of R ^Z and substituent R ^Z2 is a group represented by formula (1R),

L is >NR ^L , >O, or >S, R ^L is hydrogen, aryl which may be substituted with alkyl or cycloalkyl, heteroaryl which may be substituted with alkyl or cycloalkyl, even if substituted with cycloalkyl alkyl, or cycloalkyl which may be substituted with alkyl or cycloalkyl,

Formula (2A), Formula (2B), Formula (2C), Formula (2D), Formula (2E), Formula (2F), Formula (2G), Formula (2H), Formula (2I), Formula (2J), Or, in the structure represented by formula (2K), at least one selected from the group consisting of an aryl ring and a heteroaryl ring may be condensed with at least one cycloalkane, and the cycloalkane is aryl, heteroaryl, may be substituted with alkyl or cycloalkyl, and at least one -CH ₂ - in the cycloalkane may be substituted with -O-;

Formula (2A), Formula (2B), Formula (2C), Formula (2D), Formula (2E), Formula (2F), Formula (2G), Formula (2H), Formula (2I), Formula (2J), Alternatively, at least one hydrogen in the structure represented by formula (2K) may be substituted with heavy hydrogen, cyano or halogen.

<6> The polycyclic aromatic compound according to <5>, wherein one or two of ^RZ at the para position of Y is a group represented by formula (1R).

<7> The polycyclic aromatic compound according to <5> or <6>, wherein L is >S.

<8> The polycyclic aromatic compound according to any one of <5> to <7>, represented by formula (2A), formula (2E), formula (2G), or formula (2H).

<9> The polycyclic aromatic compound according to <8>, represented by any one of the following formulas;

In the formula, Me is methyl and tBu is t-butyl.

<10> A high molecular compound having a number average molecular weight of 2000 to 10 ⁸ obtained by polymerizing a reactive compound in which a reactive substituent is substituted for the polycyclic aromatic compound according to any one of <1> to <9> as a monomer.

<11> A composition containing the polymer compound according to <10> and an organic solvent.

<12> A material for organic devices containing the polycyclic aromatic compound according to any one of <1> to <9> or the polymer compound according to <10>.

<13> The material for an organic device according to <12>, 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.

<14> a pair of electrodes composed of an anode and a cathode, and an organic layer disposed between the pair of electrodes, wherein the organic layer is the polycyclic aromatic compound according to any one of <1> to <9> or the polycyclic aromatic compound according to <10> An organic electroluminescent device containing a polymer compound.

<15> The organic electroluminescent element according to <14>, wherein the organic layer is a light emitting layer.

<16> The organic electroluminescent device according to <15>, wherein the light emitting layer contains a host material having a lowest excitation triplet energy level of 2.70 eV or more.

<17> The organic electroluminescent device according to <15>, wherein the light-emitting layer contains an anthracene-based compound.

<18> A display device or lighting device provided with the organic electroluminescent element according to any one of <14> to <17>.

According to the present invention, a novel polycyclic aromatic compound useful as a material for organic devices such as an organic electroluminescence device is provided. The polycyclic aromatic compound of the present invention can be used for manufacturing organic devices such as organic electroluminescent elements.

1 is a schematic cross-sectional view showing an example of an organic electroluminescent device.
2 is an energy level diagram showing energy relationships among a host, an assisting dopant, and an emitting dopant of a TAF device using a typical fluorescent dopant.
3 is an energy level diagram showing an example of an energy relationship among a host, an assisting dopant, and an emitting dopant in an organic electroluminescent device according to one embodiment of the present invention.

In the following, the present invention will be described in detail. The description of the constitutional requirements described below may be made based on typical embodiments or specific examples, but the present invention is not limited to such embodiments. In addition, in this specification, the numerical range represented using "-" means the range which includes the numerical value described before and after "-" as a lower limit and an upper limit. In addition, in this specification, "hydrogen" in description of structural formula means "hydrogen atom (H)." Similarly, "carbon atom (C)" may be referred to as "carbon".

In this specification, "adjacent groups" means two groups respectively bonded to two adjacent atoms (two atoms directly bonded by covalent bonds) in the structural formula.

In the present specification, "Me" is methyl, "Et" is ethyl, "nBu" is n-butyl (normal butyl), "tBu" is t-butyl (tertiary butyl), "iBu" is isobutyl, "secBu" ” is secondary butyl, “nPr” is n-propyl (normal propyl), “iPr” is isopropyl, “tAm” is t-amyl, “2EH” is 2-ethylhexyl, “tOct” is t-octyl, “ Ph" represents phenyl, "Mes" represents mesityl (2,4,6-trimethylphenyl), "Tf" represents trifluoromethanesulfonyl, "TMS" represents trimethylsilyl, and "D" represents deuterium.

In this specification, an organic electroluminescent element is sometimes referred to as an organic EL element.

In the present specification, chemical structures and substituents are expressed in terms of carbon number, but the number of carbon atoms in the case where a substituent is substituted in a chemical structure or a substituent is further substituted in a substituent means the number of carbon atoms in each chemical structure or substituent, It does not mean the total carbon number of a chemical structure and a substituent, or the total number of carbon atoms of a substituent and a substituent. For example, "substituent B of carbon number Y substituted with substituent A of carbon number X" means that "substituent A of carbon number X" is substituted for "substituent B of carbon number Y", and carbon number Y is substituent A and substituent It is not the carbon number of the sum of B. Further, for example, "substituent B of carbon number Y substituted with substituent A" means that "substituent A (with no carbon number limitation)" is substituted for "substituent B of carbon number Y", and carbon number Y is substituent A and It is not the carbon number of the sum of the substituents B.

<Description of rings and substituents>

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

Examples of the "aryl ring" in the present specification include aryl rings having 6 to 30 carbon atoms, preferably aryl rings having 6 to 16 carbon atoms, more preferably aryl rings having 6 to 12 carbon atoms, and aryl rings having 6 to 12 carbon atoms. An aryl ring of ~10 is particularly preferred.

Specific examples of the "aryl ring" include a monocyclic benzene ring, a bicyclic biphenyl ring, a condensed bicyclic naphthalene ring, an indene ring, and a tricyclic terphenyl ring (m-terphenyl, o-terphenyl, p-terphenyl). ), a condensed tricyclic ring, acenaphthylene ring, a fluorene ring, a phenalene ring, a phenanthrene ring, anthracene ring, a condensed tetracyclic triphenylene ring, a pyrene ring, a naphthacene ring, a chrysene ring, a condensed five ring perylene ring, A pentacene ring etc. are mentioned. The fluorene ring, benzofluorene ring, and indene ring also include structures in which fluorene rings, benzofluorene rings, cyclopentane rings, and the like are spiro bonded, respectively. Further, in the fluorene ring, benzofluorene ring and indene ring, two of the two hydrogens of methylene in the structure are substituted with an alkyl such as methyl as a first substituent described below, respectively, to obtain a dimethylfluorene ring, dimethylbenzofluorene Rings, dimethylindene rings, and the like are also included.

Examples of the "heteroaryl ring" in the present specification include a heteroaryl ring having 2 to 30 carbon atoms, a heteroaryl ring having 2 to 25 carbon atoms is preferable, and a heteroaryl ring having 2 to 20 carbon atoms is more preferable. A heteroaryl ring having 2 to 15 carbon atoms is more preferred, and a heteroaryl ring having 2 to 10 carbon atoms is particularly preferred. Examples of the "heteroaryl ring" include heterocycles containing 1 to 5 heteroatoms selected from oxygen, sulfur, nitrogen, selenium, phosphorus, and tellurium in addition to carbon as ring-constituting atoms.

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 furazane ring), a thiadiazole ring, a triazole ring, and a tetracyclic ring. sol ring, pyrazole ring, pyridine ring, pyrimidine ring, pyridazine ring, pyrazine ring, triazine ring, indole ring, isoindole ring, 1H-indazole ring, benzoimidazole ring, benzooxazole ring, benzothiazole ring, 1H-benzo Triazole ring, quinoline ring, isoquinoline ring, cinnoline ring, quinazoline ring, quinoxaline ring, phthalazine ring, naphthridine ring, purine ring, pteridine ring, carbazole ring, acridine ring, phenoxathiine ring, Phenoxazine ring, phenothiazine ring, phenazine ring, phenazacillin ring, indolizine ring, furan ring, benzofuran ring, isobenzofuran ring, dibenzofuran ring, thiophene ring, benzothiophene ring, dibenzothiophene ring, thianthrene ring, indolocarbazole ring, benzoindolocarbazole ring, dibenzoindolocarbazole ring, naphthobenzofuran ring, dioxin ring, dihydroacridine ring, xanthene ring, thioxanthene ring, di A benzodioxin ring, a benzoselenophene ring, etc. are mentioned. In addition, in the dihydroacridine ring, xanthene ring, and thioxanthene ring, two of the two hydrogens of methylene in the structure thereof are substituted with an alkyl such as methyl as the first substituent described below, respectively, to obtain a dimethyldihydroacridine ring, a dimethyl xanthene ring, It is also preferable to be a dimethylthioxanthene ring or the like. Examples of the "heteroaryl ring" include a bipyridine ring, phenylpyridine ring, and pyridylphenyl ring, which are bicyclic rings, and terpyridine rings, bispyridylphenyl rings, and pyridylbiphenyl rings, which are tricyclic rings. In addition, a "heteroaryl ring" shall also include a pyran ring.

In this specification, a substituent may be substituted with another 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 other substituent or is not substituted. In some cases, "may be substituted" with the same meaning. In this specification, the specific substituent at this time may be referred to as a "first substituent" and the other substituent described above as a "second substituent".

In the present specification, the substituent group Z is,

aryl which may be substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl and cycloalkyl;

heteroaryl which may be substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl and cycloalkyl;

diarylamino which may be substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl and cycloalkyl (two aryls may be bonded to each other via a linking group);

diheteroarylamino which may be substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl and cycloalkyl (two heteroaryls may be bonded to each other via a linking group);

Arylheteroarylamino which may be substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl and cycloalkyl (aryl and heteroaryl may be bonded to each other through a linking group);

diarylboryl which may be substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl and cycloalkyl (two aryls may be bonded via a single bond or a linking group);

Alkyl which may be substituted with at least one group selected from the group consisting of aryl, heteroaryl and cycloalkyl;

cycloalkyl which may be substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl and cycloalkyl;

alkoxy which may be substituted with at least one group selected from the group consisting of aryl, heteroaryl and cycloalkyl;

aryloxy which may be substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl and cycloalkyl, and

It consists of substituted silyl.

The aryl as the second substituent in each group of the substituent group Z may be further substituted with aryl, heteroaryl, alkyl, or cycloalkyl, and similarly, the heteroaryl as the second substituent is aryl, heteroaryl, alkyl, or cycloalkyl. It may be substituted by alkyl.

In the present specification, when referring to a "substituent", any group selected from the substituent group Z may be used unless otherwise specified. For example, when a group regarded as "substituted or unsubstituted" is substituted, the group should just be substituted with at least one group selected from the substituent group Z.

In the present specification, “aryl” refers to, for example, aryl having 6 to 30 carbon atoms, and preferably includes aryl having 6 to 20 carbon atoms, aryl having 6 to 16 carbon atoms, aryl having 6 to 12 carbon atoms, or aryl having 6 to 12 carbon atoms. aryl of 10, etc.

Specific "aryl" includes, for example, monocyclic phenyl, bicyclic biphenylyl (2-biphenylyl, 3-biphenylyl, or 4-biphenylyl), condensed bicyclic naphthyl (1- naphthyl or 2-naphthyl), tricyclic terphenylyl (m-terphenyl-2'-yl, m-terphenyl-4'-yl, m-terphenyl-5'-yl, o-terphenyl -3'-yl, o-terphenyl-4'-yl, p-terphenyl-2'-yl, m-terphenyl-2-yl, m-terphenyl-3-yl, m-terphenyl-4 -yl, o-terphenyl-2-yl, o-terphenyl-3-yl, o-terphenyl-4-yl, p-terphenyl-2-yl, p-terphenyl-3-yl, or p -terphenyl-4-yl), condensed tricyclic, acenaphthylene-(1-, 3-, 4-, or 5-)yl, fluorene-(1-, 2-, 3-, 4-, or 9-)yl, phenalen-(1- or 2-)yl, phenanthrene-(1-, 2-, 3-, 4-, or 9-)yl, or anthracene-(1-, 2-, Or 9-) day, tetracyclic quaterphenylyl (5'-phenyl-m-terphenyl-2-yl, 5'-phenyl-m-terphenyl-3-yl, 5'-phenyl-m-terphenyl -4-yl, or m-quaterphenyl), condensed tetracyclic, triphenylene-(1- or 2-)yl, pyrene-(1-, 2-, or 4-)yl, or naphthacene-( 1-, 2-, or 5-)yl, or perylene-(1-, 2-, or 3-)yl, or pentacene-(1-, 2-, 5-, or 6-) days, etc. In addition, the monovalent group of spirofluorene, etc. are mentioned.

In the aryl as the second substituent, the aryl is aryl such as phenyl (specific examples are groups described above), alkyls such as methyl (specific examples are groups described later), and cycloalkyls such as cyclohexyl or adamantyl. (Specific examples are groups described later) and structures substituted with at least one group selected from the group consisting of are also included.

One example thereof is a group in which the ninth position of fluorenyl as the second substituent is substituted with an aryl such as phenyl, an alkyl such as methyl, or a cycloalkyl such as cyclohexyl or adamantyl.

"Arylene" is, for example, arylene having 6 to 30 carbon atoms, and preferably includes arylene having 6 to 20 carbon atoms, arylene having 6 to 16 carbon atoms, arylene having 6 to 12 carbon atoms, or arylene having 6 to 12 carbon atoms. Arylene of 10, etc.

A specific "arylene" includes, for example, a divalent group obtained by removing one hydrogen from the aforementioned "aryl" (monovalent group).

"Heteroaryl" is, for example, a heteroaryl having 2 to 30 carbon atoms, preferably a heteroaryl having 2 to 25 carbon atoms, a heteroaryl having 2 to 20 carbon atoms, a heteroaryl having 2 to 15 carbon atoms, or a heteroaryl having 2 to 25 carbon atoms. heteroaryl of 10; and the like. "Heteroaryl" contains one or more, preferably 1 to 5, heteroatoms selected from oxygen, sulfur, nitrogen, etc. in addition to carbon as ring-constituting atoms.

Specific examples of "heteroaryl" include pyrroleyl, oxazolyl, isoxazolyl, thiazolyl, isothiazolyl, imidazolyl, oxadiazolyl, thiadiazolyl, triazolyl, tetrazolyl, pyrazolyl, pyr Dill, pyrimidinyl, pyridazinyl, pyrazinyl, triazinyl, indolyl, isoindolyl, 1H-indazolyl, benzoimidazolyl, benzooxazolyl, benzothiazolyl, 1H-benzotriazolyl, quinolinyl , isoquinolinyl, cinnolinyl, quinazolinyl, quinoxalinyl, phenanthrolinyl, phthalazinyl, naphthyridinyl, purinyl, pteridinyl, carbazolyl, acridinyl, phenoxathinyl, phenoxazinil, phenothiazinil, phenazinyl, phenazacillinyl, indolizinyl, furanil, benzofuranil, isobenzofuranil, dibenzofuranil, naphthobenzofuranil, thienyl, benzothienyl, Isobenzothienyl, dibenzothienyl, naphthobenzothienyl, benzophosphoryl, dibenzophosphoryl, monovalent group of benzophosphole oxide ring, monovalent group of dibenzophosphole oxide ring, furazanyl, thianthrenyl , indolocarbazolyl, benzoindolocarbazolyl, dibenzoindolocarbazolyl, imidazolinyl, or oxazolinyl, and the like. In addition, a monovalent group of spiro[fluorene-9,9'-xanthene], a monovalent group of spirobi[silafluorene], and a monovalent group of benzoselenophene are exemplified.

In the heteroaryl as the second substituent, the heteroaryl is aryl such as phenyl (specific examples are groups described above), alkyls such as methyl (specific examples are groups described later), and cyclohexyl or adamantyl such as cyclohexyl. Structures substituted with at least one group selected from the group consisting of alkyl (specific examples of which will be described later) are also included.

One example thereof is a group in which the ninth position of carbazolyl as the second substituent is substituted with an aryl such as phenyl, an alkyl such as methyl, or a cycloalkyl such as cyclohexyl or adamantyl. In addition, groups in which nitrogen-containing heteroaryl such as pyridyl, pyrimidinyl, triazinyl, and carbazolyl is further substituted with phenyl or biphenylyl are also included in heteroaryl as the second substituent.

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

Specific examples of the "heteroarylene" include a divalent group obtained by removing one hydrogen from the aforementioned "heteroaryl" (monovalent group).

"Diarylamino" is amino in which two aryls are substituted, and the description of "aryl" described above can be cited for details of this aryl.

"Diheteroarylamino" is an amino group in which two heteroaryls are substituted, and the description of "heteroaryl" described above can be cited for details of this heteroaryl.

"Arylheteroarylamino" is an amino group in which aryl and heteroaryl are substituted, and the description of "aryl" and "heteroaryl" described above can be cited for details of the aryl and heteroaryl.

The two aryls in diarylamino as the first substituent may be bonded to each other via a linking group, and the two heteroaryls in diheteroarylamino as the first substituent may be bonded to each other via a linking group. The aryl and heteroaryl of arylheteroarylamino as a substituent may be bonded to each other through a linking group. Here, the description of "bonding via a linking group" indicates that, for example, two phenyls of diphenylamino form a bond with a linking group, as shown below. This statement also applies to diheteroarylamino and arylheteroarylamino, formed from aryls or heteroaryls.

(* indicates the binding position.)

Specifically as a linking group, >O, >NR ^X , >C(-R ^X ) ₂ , -(CR ^X )=(CR ^X )-, >Si(-R ^X ) ₂ , >S, >CO, > CS, >SO, >SO ₂ , and >Se. R ^X is each independently an alkyl, cycloalkyl, aryl or heteroaryl, which may be substituted with alkyl, cycloalkyl, aryl or heteroaryl. In addition, >C(-R ^X ) ₂ , -(CR ^X )=(CR ^X )-, >Si(-R ^X ) ₂ , two R ^{X '} s are mutually connected via a single bond or a linking group ^XY They may combine to form a ring. Examples of X ^Y include >O, >NR ^Y , >C(-R ^Y ) ₂ , >Si(-R ^Y ) ₂ , >S, >CO, >CS, >SO, >SO ₂ , and >Se. and R ^Y are each independently alkyl, cycloalkyl, aryl or heteroaryl, which may be substituted with alkyl, cycloalkyl, aryl or heteroaryl. However, when ^XY is >C(-R ^Y ) ₂ and >Si(-R ^Y ) ₂ , two R ^Y are bonded to each other so as not to further form a ring. Furthermore, alkenylene is also mentioned as a linking group. Any hydrogen of the alkenylene may be each independently substituted with R ^2X , and each R ^2X is independently alkyl, cycloalkyl, substituted silyl, aryl, and heteroaryl, which are alkyl, cycloalkyl, substituted silyl, or aryl. may be substituted. Two R ^{X 's} in -(CR ^X )=(CR ^X )- may be bonded to each other to form an aryl (benzene ring, etc.) or heteroaryl ring together with C=C to which they are bonded. That is, -(CR ^X )=(CR ^X )- may be arylene (1,2-phenylene, etc.) or heteroarylene.

In the present specification, when simply described as "diarylamino", "diheteroarylamino", or "arylheteroarylamino", unless otherwise specified, "two aryls of diarylamino are mutually may be bonded through a linking group”, “the two heteroaryls of the diheteroarylamino may be bonded to each other through a linking group”, and “the aryl and heteroaryl of the arylheteroarylamino may be bonded to each other through a linking group” It is said that the explanation that "it is done" is added.

"Diarylboryl" is a boryl in which two aryls are substituted, and the description of "aryl" described above can be cited for details of this aryl. In addition, these two aryls are single bonds or linking groups (for example, -CH=CH-, -CR=CR-, -C≡C-, >NR, >O, >S, >C(-R) ₂ , >Si(-R) ₂ , or >Se). Here, the R of -CR=CR-, R of >NR, 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 R may be further substituted with aryl, heteroaryl, alkyl, alkenyl, alkynyl, or cycloalkyl. Further, two adjacent Rs may be bonded to form a ring to form cycloalkylene, arylene, and heteroarylene. For the details of the substituents listed here, the description of "aryl", "arylene", "heteroaryl", "heteroarylene", and "diarylamino" described above, and "alkyl" and "alkyl" described later Descriptions of "kenyl", "alkynyl", "cycloalkyl", "cycloalkylene", "alkoxy", and "aryloxy" can be cited. In addition, when it is simply described as "diaryl boryl" in this specification, unless otherwise limited, "two aryls of diaryl boryl may be bonded to each other through a single bond or a linking group". It is said that there is

"Alkyl" may be straight-chain or branched, and is, for example, straight-chain alkyl having 1 to 24 carbon atoms or branched-chain alkyl having 3 to 24 carbon atoms, preferably, alkyl having 1 to 18 carbon atoms (carbon atoms 3 to 24). branched chain alkyl of 18), alkyl of 1 to 12 carbon atoms (branched chain alkyl of 3 to 12 carbon atoms), alkyl of 1 to 6 carbon atoms (branched chain alkyl of 3 to 6 carbon atoms), alkyl of 1 to 5 carbon atoms (3 carbon atoms) -5 branched chain alkyl), C1-4 alkyl (C3-4 branched chain alkyl), and the like.

Specific "alkyl" includes, for example, methyl, ethyl, n-propyl, isopropyl, 1-ethyl-1-methylpropyl, 1,1-diethylpropyl, 1,1,2-trimethylpropyl, 1,1 ,2,2-tetramethylpropyl, 1-ethyl-1,2,2-trimethylpropyl, n-butyl, isobutyl, s-butyl, t-butyl, 2-ethylbutyl, 1,1-dimethylbutyl, 3 ,3-dimethylbutyl, 1,1-diethylbutyl, 1-ethyl-1-methylbutyl, 1-propyl-1-methylbutyl, 1,1,3-trimethylbutyl, 1-ethyl-1,3-dimethyl Butyl, 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, t-octyl (1,1,3,3-tetramethylbutyl), 1,1-dimethyloctyl, n-nonyl, n-decyl, 1-methyldecyl , n-undecyl, n-dodecyl, n-tridecyl, n-tetradecyl, n-pentadecyl, n-hexadecyl, n-heptadecyl, n-octadecyl, or n-eicosyl.

"Alkylene" is a divalent group obtained by removing any one of the "alkyl" hydrogens, and is, for example, methylene, ethylene, or propylene.

Regarding "alkenyl", the description of "alkyl" described above can be referred to, and it is a group in which the C-C single bond in the structure of "alkyl" is substituted with a C=C double bond, and not only one but two or more groups Also included are groups in which a bond is replaced by a double bond (also called alkadien-yl or alkathien-yl).

"Alkenylene" is a divalent group obtained by removing any hydrogen from "alkenyl", and examples thereof include vinylene.

Regarding "alkynyl", the description of "alkyl" described above can be referred to, and it is a group in which the C-C single bond in the structure of "alkyl" is substituted with a C≡C triple bond, and not only one but two or more groups Also included are groups in which a bond is replaced by a triple bond (also called alkadiyn-yl or alkathrin-yl).

"Cycloalkyl" is, for example, a cycloalkyl of 3 to 24 carbon atoms, preferably a cycloalkyl of 3 to 20 carbon atoms, a cycloalkyl of 3 to 16 carbon atoms, a cycloalkyl of 3 to 14 carbon atoms, and a cycloalkyl of 3 to 12 carbon atoms. cycloalkyl, cycloalkyl having 5 to 10 carbon atoms, cycloalkyl having 5 to 8 carbon atoms, cycloalkyl having 5 to 6 carbon atoms, or cycloalkyl having 5 carbon atoms.

Specific "cycloalkyl" includes, for example, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl, or alkyls having 1 to 5 carbon atoms or 1 to 4 carbon atoms (especially methyl) substituents, 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, bi cyclo[2.2.1]heptyl (norbornyl), bicyclo[2.2.2]octyl, adamantyl, diamantyl, decahydronaphtharenyl, or decahydroazulenyl, and the like.

"Cycloalkylene" is, for example, a cycloalkylene having 3 to 24 carbon atoms, preferably a cycloalkylene having 3 to 20 carbon atoms, a cycloalkylene having 3 to 16 carbon atoms, or a cycloalkylene having 3 to 14 carbon atoms. , C3-C12 cycloalkylene, C5-10 cycloalkylene, C5-8 cycloalkylene, C5-6 cycloalkylene, or C5 cycloalkylene.

Specific examples of "cycloalkylene" include a structure made into a divalent group by removing one hydrogen from the aforementioned "cycloalkyl" (monovalent group).

"Cycloalkenyl" refers to a group having a structure in which a single bond between at least one set of two carbon atoms in the above-mentioned "cycloalkyl" is a double bond (eg, -CH ₂ -CH ₂ - a group substituted with -CH=CH-), and groups not corresponding to aryl may be mentioned. Specifically, 1-cyclohexenyl, 1-cyclopentenyl, etc. are mentioned.

"Alkoxy" is a group represented by "Alk-O- (Alk is alkyl)", and the description of "alkyl" described above can be cited for details of this alkyl.

"Aryloxy" is a group represented by "Ar-O- (Ar is aryl)", and the description of "aryl" described above can be cited for details of this aryl.

"Substituted silyl" is, for example, silyl substituted with at least one of aryl, alkyl, and cycloalkyl, preferably triarylsilyl, trialkylsilyl, tricycloalkylsilyl, dialkylcycloalkylsilyl, or alkyl dicycloalkylsilyl.

"Triarylsilyl" is a silyl group substituted with three aryls, and the description of "aryl" described above can be cited for details of this aryl.

Specific examples of "triarylsilyl" include triphenylsilyl, diphenylmononaphthylsilyl, monophenyldinaphthylsilyl, and trinaphthylsilyl.

"Trialkylsilyl" is a silyl group substituted with three alkyls, and the description of "alkyl" described above can be cited for details of this alkyl.

Specific "trialkylsilyl" includes, for example, trimethylsilyl, triethylsilyl, trin-propylsilyl, triisopropylsilyl, trin-butylsilyl, triisobutylsilyl, tris-butylsilyl, trit- Butylsilyl, ethyldimethylsilyl, n-propyldimethylsilyl, isopropyldimethylsilyl, n-butyldimethylsilyl, isobutyldimethylsilyl, s-butyldimethylsilyl, t-butyldimethylsilyl, methyldiethylsilyl, n-propyldi Ethylsilyl, isopropyldiethylsilyl, n-butyldiethylsilyl, s-butyldiethylsilyl, t-butyldiethylsilyl, methyldi-n-propylsilyl, ethyldi-n-propylsilyl, n-butyldin- propylsilyl, s-butyldin-propylsilyl, t-butyldin-propylsilyl, methylisopropylsilyl, ethyldiisopropylsilyl, n-butyldiisopropylsilyl, s-butyldiisopropylsilyl, or t -Butyldiisopropylsilyl, etc.

"Tricycloalkylsilyl" is a silyl group substituted with three cycloalkyls, and the description of "cycloalkyl" described above can be cited for details of this cycloalkyl.

Specific "tricycloalkylsilyl" is, for example, tricyclopentylsilyl or tricyclohexylsilyl.

"Dialkylcycloalkylsilyl" is a silyl group substituted with two alkyls and one cycloalkyl, and the descriptions of "alkyl" and "cycloalkyl" described above can be cited for details of these alkyls and cycloalkyls. .

"Alkyldicycloalkylsilyl" is a silyl group substituted with one alkyl and two cycloalkyls, and for details of these alkyls and cycloalkyls, the descriptions of "alkyl" and "cycloalkyl" described above can be cited. .

<When two groups bonded to the same atom bond to each other>

In the present specification, when it is said that two groups bonded to the same atom may be bonded to each other to form a ring, they may be bonded by a single bond or a linking group (these are collectively referred to as a linking group), and the linking group is -CH ₂ -CH ₂ -, -CHR-CHR-, -CR ₂ -CR ₂ -, -CH=CH-, -CR=CR-, -C≡C-, -N(-R)-, -O-, -S-, -C(-R) ₂ -, -Si(-R) ₂ -, or -Se-, and examples thereof include the following structures. In addition, R of -CHR-CHR-, R of -CR ₂ -CR ₂ -, R of -CR=CR-, R of -N(-R)-, R of -C(-R) ₂ -, and R in -Si(-R) ₂ - are each independently hydrogen, aryl which may be substituted with alkyl or cycloalkyl, heteroaryl which may be substituted with alkyl or cycloalkyl, alkyl which may be substituted with cycloalkyl , alkenyl which may be substituted with alkyl or cycloalkyl, alkynyl which may be substituted with alkyl or cycloalkyl, or cycloalkyl which may be substituted with alkyl or cycloalkyl. Further, two adjacent Rs may be bonded to form a ring to form cycloalkylene, arylene, or heteroarylene.

As a bonding group, -CR=CR-, -N(-R)-, -O-, -S-, -C(-R) ₂ -, -Si(-R) ₂ -, and - as a single bond or a linking group. Se- is preferable, and -CR=CR-, -N(-R)-, -O-, -S-, and -C(-R) ₂ - as a single bond or linking group are more preferable, and a single bond, -CR=CR-, -N(-R)-, -O-, and -S- as linking groups are more preferred, and a single bond is most preferred.

The position at which two R are bonded by a bonding group is not particularly limited as long as it can be bonded to, but it is preferable to bond at the most adjacent position, for example, when the two groups are phenyl, "C" in phenyl or It is preferable to bond to each other at ortho (second position) positions with the bonding position (first position) of "Si" as a reference (see the above structural formula).

1. Polycyclic aromatic compounds

<Description of the overall structure of the compound>

The present inventors have found that a polycyclic aromatic compound in which aromatic rings are linked by a hetero element such as boron, nitrogen, oxygen, or sulfur has a large HOMO-LUMO gap (band gap Eg in a thin film). This is because the 6-membered ring containing the hetero element has low aromaticity, and the decrease in the HOMO-LUMO gap due to the expansion of the conjugated system is suppressed. In addition, it was found that the HOMO-LUMO gap can be arbitrarily changed depending on the type and connection method of the hetero element. This is considered to be caused by the fact that the energies of HOMO and LUMO can be arbitrarily moved according to the spatial diffusion and energy of vacant orbits or lone pairs of hetero elements.

In these polycyclic aromatic compounds, SOMO1 and SOMO2 in an excited state are localized on each atom by electronic perturbation of a hetero element, so that the half-width of the fluorescence emission peak is narrow, and when used as a dopant in an organic EL device, emission of high color purity occurs. is obtained For the same reason, ΔE _S1T1 is reduced to show thermally activated delayed fluorescence, and high efficiency can be obtained when used as an emitting dopant for an organic EL device.

Furthermore, since the energies of HOMO and LUMO can be moved arbitrarily by introducing a substituent, it is possible to optimize the ionization potential or electron affinity according to the surrounding material. However, the present invention is not particularly limited to this principle.

The polycyclic aromatic compound of the present invention has a structure composed of one or two or more structural units represented by the following formula (1), and at least one selected from the group consisting of ring A, ring B, and ring C has the formula It is an aryl ring substituted with the group represented by (1R) or a heteroaryl ring substituted with the group represented by formula (1R).

<Formula (1R)>

The polycyclic aromatic compound of the present invention includes at least one group represented by formula (1R) in its structure. The group represented by formula (1R) exists as a substituent on an aryl ring or heteroaryl ring, and the aryl ring or heteroaryl ring to which the group represented by formula (1R) is bonded constitutes ring A, ring B, or ring C.

As described above, the polycyclic aromatic compound of the present invention containing the group represented by formula (1R) emits light of a shorter wavelength (e.g., deeper blue light) than similar compounds that do not contain the group represented by formula (1R). ) was found to be obtained. A polycyclic aromatic structure in which an aromatic ring is linked by a hetero element such as boron, nitrogen, oxygen, or sulfur receives strong electron donation from a group represented by formula (1R) formed by condensing a plurality of aromatic rings with an azepine ring, resulting in HOMO-LUMO I think it's because the gap got bigger.

In formula (1R), "F", "G", and "H" in a circle are symbols representing ring structures represented by circles, and the F ring, G ring, and H ring are each a substituted or unsubstituted aryl ring. , or a substituted or unsubstituted heteroaryl ring. The F ring, the G ring, and the H ring each form a divalent group having bonds at two carbon atoms adjacent to each other on the ring of the aryl ring or heteroaryl ring in the structure, and the two bonds, F ring is nitrogen and The G ring and the G ring are bonded to the F ring and the H ring, and the H ring is bonded to the nitrogen and the G ring.

When referring to "substituted or unsubstituted (substituted or unsubstituted)" in the substituted or unsubstituted aryl ring in the F ring, the G ring, and the H ring, or the substituted or unsubstituted heteroaryl ring As the substituent, at least one substituent selected from the group consisting of the substituent group Z and the substituent represented by the formula (A30) is preferable.

The F ring, the G ring, and the H ring are all preferably a substituted or unsubstituted benzene ring or a substituted or unsubstituted naphthalene ring, more preferably a substituted or unsubstituted benzene ring, and more preferably an unsubstituted benzene ring. more preferable

* is a bonding position (bonding hand position) of a group represented by formula (1R).

The group represented by formula (1R) is preferably a group represented by formula (2R).

In formula (2R), R ^AZ is each independently hydrogen, any substituent selected from substituent group Z, or a substituent represented by formula (A30), and adjacent R ^AZ bonds to the ring to which they are directly bonded. Together, an aryl ring or heteroaryl ring may be formed, and the formed ring may be substituted with at least one substituent selected from the group consisting of substituent group Z and a substituent represented by formula (A30). * is a bonding position (bonding hand position) of a group represented by formula (2R). R ^AZ is each independently preferably hydrogen or unsubstituted alkyl. It is also preferable that any one to three sets of adjacent R ^AZ are bonded together to form an aryl ring or heteroaryl ring together with the ring to which they are directly bonded. A naphthalene ring is mentioned as a ring formed. The naphthalene ring is preferably formed so as to share the bond between the 2nd and 3rd positions with the azepine ring.

From the viewpoint of synthesis, it is preferable that all of R ^AZ are hydrogen.

From the viewpoint of luminous efficiency, it is preferable that 1 to 3 of R ^AZ are unsubstituted alkyl and the other R ^AZ is hydrogen. When two or more of R ^AZ are substituents such as unsubstituted alkyl, the number is preferably 1 to 2, more preferably 1, in each of the f ring, g ring, and h ring.

The group represented by formula (1R) is preferably introduced at the para position of Y (particularly boron) in the benzene ring from the viewpoint of wavelength. As a blue light emitting material, it can be set as the structure which exhibits light emission favorable.

The number of groups represented by formula (1R) in the polycyclic aromatic compound of the present invention is not particularly limited, but is preferably one in a polycyclic aromatic compound having a structure composed of one structural unit represented by formula (1), In the polycyclic aromatic compound having a structure composed of two structural units represented by Formula (1), one or two units are preferred, and two units are more preferred.

Among the A rings, B rings and C rings, ring A is preferably an aryl ring substituted with a group represented by formula (1R) or a heteroaryl ring substituted with a group represented by formula (1R).

In the polycyclic aromatic compound of the present invention, the aryl ring substituted with a group represented by formula (1R) and the heteroaryl ring substituted with a group represented by formula (1R) each have a substituent other than the group represented by formula (1R) You may or may not have a . The aryl ring substituted with a group represented by formula (1R) and the heteroaryl ring substituted with a group represented by formula (1R) are each preferably substituted with only one group represented by formula (1R).

<Description of Ring Structure in Compound>

In Formula (1), "A", "B", and "C" in circles are codes representing ring structures represented by respective circles. The structural unit represented by Formula (1) has a structure in which a ring structure is further formed by connecting at least three aromatic rings, which are A, B, and C, with hetero elements such as boron, oxygen, nitrogen, and sulfur. The formed ring structure is a condensed ring structure composed of at least 5 rings.

A ring, B ring, and C ring 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 the A ring, B ring, and C ring of the structural unit represented by Formula (1), "substituted or unsubstituted (substituted or As the substituent in the case of “unsubstituted)”, at least one substituent selected from the group consisting of the substituent group Z and the substituent represented by the formula (A30) is preferable as the substituent other than the group represented by the formula (1R). .

The A ring forms a trivalent group having bonds at three consecutive carbon atoms of the aryl ring or heteroaryl ring in its structure. Each of these three bonds binds to two X and Y. When ring A is bonded to R ^X , it may be a tetravalent or pentavalent group. Among the A rings, the ring containing carbon having the above three bonds as a ring constituent element is preferably a 5-membered ring or a 6-membered ring, and more preferably a 6-membered ring. This ring may further condense with another ring. A benzene ring, a pyridine ring, a pyrazine ring, a pyrimidine ring etc. are mentioned as an example of a 6-membered ring. Examples of further condensation of a 6-membered ring with another ring include a naphthalene ring, a quinoline ring, a dibenzofuran ring, a dibenzothiophene ring, and a carbazole ring. Examples of the 5-membered ring include a furan ring, a thiophene ring, a pyrrole ring, and a thiazole ring. Examples of further condensation of a 5-membered ring with another ring include a benzofuran ring, a benzothiophene ring, and an indole ring.

Both the B ring and the C ring form a divalent group having a bond at two carbon atoms adjacent to each other in the aryl or heteroaryl ring in the structure. Ring B is bonded to X and Y on the above two bonds, and ring C is bonded to Y and X on the above two bonds. When ring B and ring C are each further bonded to R ^X , they may be trivalent or tetravalent. Among the B rings and the C rings, the ring containing carbon having the above two bonds as a ring constituent element is preferably a 5-membered ring or a 6-membered ring, and more preferably a 6-membered ring. This ring may further condense with another ring. A benzene ring, a pyridine ring, a pyrazine ring, a pyrimidine ring etc. are mentioned as an example of a 6-membered ring. Examples of further condensation of a 6-membered ring with another ring include a naphthalene ring, a quinoline ring, a dibenzofuran ring, a dibenzothiophene ring, and a carbazole ring. Examples of the 5-membered ring include a furan ring, a thiophene ring, a pyrrole ring, and a thiazole ring. Examples of further condensation of a 5-membered ring with another ring include a benzofuran ring, a benzothiophene ring, and an indole ring.

<Structure consisting of one or more structural units>

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). The polycyclic aromatic compound having a structure consisting of one of the above structural units is a polycyclic aromatic compound represented by the formula described above as the structural unit represented by formula (1). The polycyclic aromatic compound having a structure composed of two or more structural units represented by formula (1) is a compound corresponding to a multimer of the polycyclic aromatic compound represented by the formula described above as the structural unit represented by formula (1). . As for a multimer, a 2-hexamer is preferable, a 2-trimer is more preferable, and a dimer is still more preferable. The multimer may be in the form of having a plurality of the above unit structures in one compound, even if it is a form in which any rings (A rings, B rings, or C rings) contained in the above structural units are shared by a plurality of unit structures and bonded. Alternatively, a form in which arbitrary rings (rings A, B, and C) included in the unit structure are condensed and bonded may be used. In addition, an arbitrary ring (A ring, B ring, or C ring) contained in the structural unit and an X bonded thereto may be shared in a plurality of unit structures and bonded together. The form in which the said unit structure couple|bonded with coupling groups, such as a single bond and C1-C3 alkylene, phenylene, and naphthylene, may be sufficient. Among these, a form in which rings are shared and bonded is preferable.

An example of a structure composed of two structural units bonded by sharing a ring is shown below.

<Description of Y>

Y in each formula is >B-, >P-, >P(=O)-, >P(=S)-, >Al-, >Ga-, >As-, >C(-R ^Y )- , >Si(-R ^Y )-, or >Ge(-R ^Y )-, and R ^Y is each independently an optionally substituted aryl, optionally substituted heteroaryl, optionally substituted alkyl, or substituted It is an optional cycloalkyl. In the case of >P(=O)-, >P(=S)-, >C(-R ^Y )-, >Si(-R ^Y )-, or >Ge(-R)-, ring A, B An atom bonded to the ring and the C ring is P, C, Si, or Ge. Y is preferably >B-, >P-, >P(=O)-, >P(=S)-, >C(-R ^Y )-, or >Si(-R ^Y )-, and > B-, >P(=O)-, or >P(=S)- is more preferable, and >B- is particularly preferable.

<Description of X>

X is each independently >NR ^X , >O, >S, >C(-R ^X ) ₂ , >Si(-R ^X ) ₂ , or >Se, and R ^X is, each independently, hydrogen, optionally substituted aryl, optionally substituted heteroaryl, optionally substituted alkyl or optionally substituted cycloalkyl, >C(-R ^X ) ₂ of two R ^X and >Si(-R ^X ) ₂ of Two R ^X 's may be bonded through a single bond or a linking group, respectively.

As X, >NR ^X , >O, or >S is preferable. It is preferred that at least one of X is >NR ^X. R ^X in >NR ^X is preferably substituted or unsubstituted phenyl.

In the compound represented by formula (2A), formula (2B), or formula (2E) described later, all X's should be >NR ^X or >S from the viewpoint of TADF property and the emission wavelength that exhibits light emission suitable as a blue light emitting material. It is preferable from the viewpoint, and X is >NR ^X is 2 to 3, and >S is 2 to 1 is most preferable from the viewpoint of coexistence of excellent TADF properties. In addition, in the compound represented by formula (2A), formula (2B), or formula (2E), it is preferable that 1 or 2 of X are >0 from the viewpoint of obtaining shorter wavelength light emission, and from the viewpoint of TADF property > A structure in which O is zero or >O is unevenly distributed as two is preferable.

<Explanation of the change in the ring structure due to the combination of X and the ring>

R ^X in X may be bonded to one or two selected from the group consisting of A ring, B ring and C ring by a single bond or a linking group. Specifically, any one or both (preferably any one) of the rings to which X containing the relevant R ^X is directly bonded (a ring in which the carbon atom at the β position of R ^X is contained as a ring-constituting atom) may be combined with

As a linking group in case R ^X is bonded to at least one ring in ring A, ring B and ring C, -CH ₂ -CH ₂ -, -CHR-CHR-, -CR ₂ -CR ₂ -, -CH= CH-, -CR=CR-, -C≡C-, -N(-R)-, -O-, -S-, -C(-R) ₂ -, -Si(-R) ₂ -, or -Se- etc. are mentioned. 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 preferable, and -CR=CR-, -N(-R)-, -O-, and -S- are more preferable than R of “-CHR-CHR-”, R of “-CR ₂ -CR ₂ -”, R of “-CR=CR-”, R of “-N(-R)-”, R of “-C(- R of _2- ” and R of “-Si(-R) _2- ” are each independently hydrogen, aryl which may be substituted with alkyl or cycloalkyl, hetero which may be substituted with alkyl or cycloalkyl aryl, alkyl which may be substituted with cycloalkyl, alkenyl which may be substituted with alkyl or cycloalkyl, alkynyl which may be substituted with alkyl or cycloalkyl, or cycloalkyl which may be substituted with alkyl or cycloalkyl . In addition, two R's bonded to the same element may be bonded to form a ring. In addition, two adjacent Rs may be bonded to form a cycloalkylene ring, an arylene ring, and a heteroarylene ring. These rings may also be substituted with alkyl or cycloalkyl.

As an example of a structure in which R ^X is bonded to at least one ring in the A ring, the B ring, and the C ring by a linking group or a single bond, represented by the following formula (1-3-1), X is condensed ring B' and compounds having a ring structure in which X is encapsulated in condensed ring A' represented by the following formula (1-3-2). The formed condensed ring B' (or condensed ring A') is, for example, a carbazole ring, a phenoxazine ring, or a phenothiazine ring.

At least one of X linking the ring structure and the ring structure is >NR ^X , this R ^X is an optionally substituted alkyl or an optionally substituted cycloalkyl, and by a linking group or a single bond, ring A, ring B, Or you may have a structure connected with the aryl ring or heteroaryl ring in at least one of C rings.

For example, the following partial structure A10 may be formed by the above connection.

In formula (A10), R ^{A1 to} R ^A4 are each independently hydrogen, optionally substituted alkyl or optionally substituted cycloalkyl, and any 2 to 4 of R ^{A1 to} R ^A4 are linked to a linking group or a single bond may be bonded to each other, and is bonded to one ring of the two rings to which X is bonded at the position of two * and to the other ring at the position of **. That is, N in formula (A10) is N of >NR ^X when X is >NR ^X. The cyclic atoms bonded at the positions of two * may be atoms adjacent to each other (preferably carbon atoms). Although the partial structure represented by formula (A10) includes NC bonds with weak bond dissociation energy (BDE), the presence of another bond forming a ring promotes the reverse reaction (recombination reaction) even when NC bonds are cleaved. , resulting in a more stable structure. Therefore, in the organic EL device manufactured using the polycyclic aromatic compound of the present invention having such a structure, a longer device lifetime is expected. When the structure represented by formula (A10) is included in the polycyclic aromatic compound of the present invention, the number may be one or two.

In formula (A10), R ^{A1 to} R ^A4 are hydrogen, optionally substituted alkyl or optionally substituted cycloalkyl, and any two to four of R ^{A1 to} R ^A4 may be linked to each other by a linking group.

R ^{A1 to} R ^A4 are any two (R ^A1 and R ^A4 , R ^A1 and R ^A4 and R A1 and R ^A4 , R ^A1 and R ^A2 , R ^A3 and R ^A4 , R ^A1 and R ^A4 and ^{R A1} and R ^A4 ) are preferably bonded to each other via a linking group or a single bond, and more preferably, R ^A1 and R ^A4 are bonded to each other via a linking group or single bond. Examples of the divalent groups formed by bonding to each other include alkylene. At least one hydrogen in the alkylene may be substituted with alkyl or cycloalkyl, and at least one (preferably one) -CH ₂ - in the alkylene is -O- and -S- may be substituted with As the divalent group formed by bonding to each other, preferably a straight-chain alkylene having 2 to 5 carbon atoms, more preferably a straight-chain alkylene having 3 or 4 carbon atoms, and a straight-chain alkylene having 4 carbon atoms (-(CH ₂ ) ₄ -). more preferable than It is particularly preferred that the straight-chain alkylene having 4 carbon atoms (-(CH ₂ ) ₄ -) be unsubstituted.

The remaining R ^{A1 to} R ^A4 not involved in the connection by the linking group are each independently preferably hydrogen or optionally substituted alkyl, more preferably optionally substituted alkyl having 1 to 6 carbon atoms, It is more preferable that it is unsubstituted C1-C6 alkyl, and it is most preferable that all are methyl.

That is, as the partial structure represented by formula (A10), a structure represented by the following formula (A11) is preferable.

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

<Formula (2A), Formula (2B), Formula (2C), Formula (2D), Formula (2E), Formula (2F), Formula (2G), Formula (2H), Formula (2I), Formula (2J) , expression (2K)>

As an example of a structure composed of one or two or more structural units represented by formula (1), the following formula (2A), formula (2B), formula (2C), formula (2D), formula (2E), formula (2F) ), a structure represented by any one of formula (2G), formula (2H), formula (2I), formula (2J), or formula (2K).

Formula (2A), Formula (2B), Formula (2C), Formula (2D), Formula (2E), Formula (2F), Formula (2G), Formula (2H), Formula (2I), Formula (2J), and ring a and its substituent R ^Z , ring b and its substituent R ^Z , ring c and its substituent R ^Z in formula (2K) correspond to ring A, ring B and ring C in formula (1), respectively. . Ring d and its substituent R ^Z , ring e and its substituent R ^Z correspond to ring A and ring B (or ring C) in formula (1), respectively. Equation (2A), Equation (2B), Equation (2C), Equation (2D), Equation (2E), Equation (2F), Equation (2G), Equation (2H), Equation (2I), Equation (2J) ), and formula (2K) correspond to structures in which specific rings are selected as ring A, ring B, and ring C in formula (1), respectively. In that sense, each ring in each formula is represented by lowercase letters "a", "b", "c", "d", and "e". In addition, the symbol attached to the ring containing L represents a condensed ring composed of a ring containing L and a benzene ring condensed therewith.

Formula (2A), Formula (2B), Formula (2C), Formula (2D), Formula (2E), Formula (2F), Formula (2G), Formula (2H), Formula (2I), Formula (2J), And in the formula (2K), Y and X have the same meaning as Y and X in the formula (1), respectively, and the preferred ranges are also the same.

In the above formula, R ^Z is each independently hydrogen, any substituent selected from substituent group Z, or a substituent represented by formula (A30), and adjacent R ^Z are bonded together with the ring to which they are directly bonded to aryl A ring or heteroaryl ring may be formed, and the formed ring may be substituted with at least one substituent ^RZ2 selected from the group consisting of the substituent group Z and the substituent represented by formula (A30).

However, in each formula, at least one selected from the group consisting of R ^Z and substituent R ^Z2 is a group represented by formula (1R). It is preferable that any one or two ^RZ 's are groups represented by formula (1R), and it is more preferable that ^RZ bonded to the benzene ring is a group represented by formula (1R). It is preferable that R ^Z of the group represented by formula (1R) is at the para position of Y.

In each of the above formulas, as substituents ^RZ and ^RZ2 , as substituents other than the group represented by formula (1R), alkyl, phenyl which may be substituted with alkyl, diphenylamino which may be substituted with alkyl or phenyl, It is preferable that it is carbazolyl which may be substituted by alkyl or phenyl. As substituents R ^Z and R ^Z2 , the description of preferred substituents described later can also be referred to.

In each formula, it is also preferable that all of R ^Z other than the group R ^Z represented by formula (1R) are hydrogen.

In Formula (2A), Formula (2B), Formula (2C), Formula (2D), Formula (2H), Formula (2I), Formula (2J), and Formula (2K), L is >NR ^L , > O, or >S, R ^L is hydrogen, aryl which may be substituted with alkyl or cycloalkyl, heteroaryl which may be substituted with alkyl or cycloalkyl, alkyl which may be substituted with cycloalkyl, or alkyl or cycloalkyl Cycloalkyl which may be substituted with is preferable, and aryl which may be substituted with alkyl or cycloalkyl is preferable, and phenyl which may be substituted with alkyl is more preferable.

It is preferred that L is >S.

Among the polycyclic aromatic compounds represented by Formula (2A), Formula (2B), Formula (2C), Formula (2D), Formula (2E), or Formula (2F), which are structures containing two structural units, blue light-emitting As the compound, a polycyclic aromatic compound represented by formula (2A), formula (2B), or formula (2E), which is a structure containing two structural units such that two Ys are located at the meta position of c ring, is preferable, and has green light-emitting properties. As the compound, a polycyclic aromatic compound represented by formula (2C), formula (2D) or formula (2F), which is a structure containing two structural units such that two Ys are located at the para-position of the c ring, is preferable. Among blue light-emitting compounds, polycyclic aromatic compounds represented by formula (2A) or formula (2E) are preferred, and polycyclic aromatic compounds represented by formula (2A) are more preferred because they have a small ΔE _S1T1 and fast delayed fluorescence. do.

Among the polycyclic aromatic compounds represented by Formula (2G), Formula (2H), Formula (2I), Formula (2J), or Formula (2K), Formula (2G), Formula (2I), or Formula (2K) is ΔE Since _S1T1 is small and delayed fluorescence is fast, it is more preferable.

<Description of change in ring structure due to bonding of substituents>

Formula (2A), Formula (2B), Formula (2C), Formula (2D), Formula (2E), Formula (2F), Formula (2G), Formula (2H), Formula (2I), Formula (2J), And in the formula (2K), adjacent groups among the substituents ^RZ may be bonded to each other to form an aryl ring or a heteroaryl ring together with the ring to which they are bonded. The formed ring may be substituted with at least one substituent selected from the group consisting of the substituent group Z and the substituent represented by the formula (A30) other than the group represented by the formula (1R).

Therefore, Equation (2A), Equation (2B), Equation (2C), Equation (2D), Equation (2E), Equation (2F), Equation (2G), Equation (2H), Equation (2I), Equation (2J) ), or the polycyclic aromatic compound represented by formula (2K), depending on the mutual bonding form of the substituents in the a ring, b ring, c ring, d ring and e ring, examples of a ring and b ring are given below. As shown in formulas (2AB-fr1) to (2AB-fr3), the ring structure constituting the compound is changed. Ring A' and ring B' in each formula correspond to ring A and ring B in formula (1), respectively. In addition, each formula|equation shows only the part of a unit structure for brevity.

When the A' ring and the B' ring in the above formulas (2AB-fr1) to (2AB-fr3) are explained by formulas (2A) and (2B), adjacent groups among a plurality of substituents R ^Z are bonded to each other, It represents an aryl ring or heteroaryl ring formed together with ring a and ring b (it can also be referred to as a condensed ring formed by condensation of another ring structure with ring a or b).

Specific examples of the formulas (2AB-fr1) to (2AB-fr3) include, for example, a benzene ring, an indole ring, a pyrrole ring, a benzofuran ring, or a benzothiophene ring with respect to a benzene ring which is ring a or b. a structure having an A' ring or a B' ring formed by condensation of the like, and the condensed ring A' or condensed ring B' formed is, respectively, a naphthalene ring, a carbazole ring, an indole ring, a dibenzofuran ring, or Dibenzothiophene ring etc.

For example, more specific examples of formulas (2AB-fr1) to (2AB-fr3) are shown below.

Formula (2AB-fr1-ex) is a specific example of formula (2AB-fr1), wherein two adjacent ^RZs in ring a are bonded together with ring a (benzene ring), represented by A' This is an example in which an aryl ring (naphthalene ring) is formed. The formed aryl ring has a 6-membered ring (benzene ring a) bonded directly to Y. In addition, the arbitrary substituents on the aryl ring A' (ring A of Formula (1)) are represented by n pieces of R other than R ^Z , and the upper limit of n is the maximum number that can be substituted.

The formula (2AB-fr2-ex) is a specific example of the formula (2AB-fr2), wherein two adjacent ^RZs in the b ring are bonded together with the b ring (benzene ring), represented by B'. This is an example in which a heteroaryl ring (carbazole ring) is formed. The formed heteroaryl ring has a 6-membered ring (benzene ring b) bonded directly to Y. In addition, the arbitrary substituents on the heteroaryl ring B' (ring B in formula (1)) are represented by n pieces of R other than R ^Z , and the upper limit of n is the maximum number that can be substituted.

Formula (2AB-fr3-ex) is a specific example of formula (2AB-fr3), wherein two adjacent ^RZs in ring a are bonded together with ring a (benzene ring), represented by A' An example in which a heteroaryl ring (dibenzofuran ring) is formed, two adjacent ^RZs in the b ring are bonded, and an aryl ring (naphthalene ring) represented by B' is formed together with the b ring (benzene ring) am. The formed heteroaryl ring and aryl ring have a benzene ring a and a benzene ring b directly bonded to Y. In addition, the arbitrary substituents on the heteroaryl ring A' (ring A in formula (1)) and aryl ring B' (ring B in formula (1)) are represented by n R's other than R ^Z , and the upper limit of n is This is the maximum number of possible substitutions.

The above description can be similarly applied to all forms other than the specific examples described above.

<Other preferred substituents>

When a polycyclic aromatic compound having a structure containing a structural unit represented by Formula (1) is used as a dopant (assisting dopant or an emitting dopant), in other compounds used as dopants, "alkyl" containing As a substituent, tertiary alkyl represented by the following formula (tR) is one of particularly preferable substituents for the aryl or heteroaryl rings in the A, B, C and D rings. This is because the luminescence quantum yield (PLQY) is improved because the intermolecular distance is increased by such a bulky substituent. Further, a substituent in which the tertiary alkyl represented by the formula (tR) is substituted with another substituent as the second substituent is also preferable. Specifically, diarylamino substituted with tertiary alkyl represented by formula (tR), carbazolyl (preferably N-carbazolyl) substituted with tertiary alkyl represented by formula (tR), or formula (tR) and benzocarbazolyl (preferably N-benzocarbazolyl) substituted with tertiaryalkyl represented by (tR). As the substitution form of the group of formula (tR) in diarylamino, carbazolyl and benzocarbazolyl, examples in which some or all hydrogens of the aryl ring or benzene ring in these groups are substituted with groups of formula (tR) are given. can do.

In formula (tR), R ^a , R ^b , and R ^c are each independently an alkyl having 1 to 24 carbon atoms, and any -CH ₂ - in the alkyl may be substituted with -O-, and the formula ( The group represented by tR) has * as a binding position.

As "alkyl having 1 to 24 carbon atoms" for R ^a , R ^b , and R ^c , either straight-chain or branched chain may be used, and examples thereof include straight-chain alkyl having 1 to 24 carbon atoms or branched-chain alkyl having 3 to 24 carbon atoms. , C1-18 alkyl (C3-18 branched chain alkyl), C1-12 alkyl (C3-12 branched chain alkyl), C1-6 alkyl (C3-6 branched chain alkyl) ), and alkyl having 1 to 4 carbon atoms (branched chain alkyl having 3 to 4 carbon atoms).

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

Specific examples of alkyl of R ^a , R ^b , and R ^c include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, s-butyl, t-butyl, n-pentyl, isopentyl, neopentyl, t-pentyl, n-hexyl, 1-methylpentyl, 4-methyl-2-pentyl, 3,3-dimethylbutyl, 2-ethylbutyl, n-heptyl, 1-methylhexyl, n-octyl, t-octyl, 1-methylheptyl, 2-ethylhexyl, 2-propylpentyl, n-nonyl, 2,2-dimethylheptyl, 2,6-dimethyl-4-heptyl, 3,5,5-trimethylhexyl, n-decyl, n -Undecyl, 1-methyldecyl, n-dodecyl, n-tridecyl, 1-hexylheptyl, n-tetradecyl, n-pentadecyl, n-hexadecyl, n-heptadecyl, n-octadecyl, n -Ecosil etc. can be mentioned.

Examples of the group represented by formula (tR) include t-butyl, t-amyl, 1-ethyl-1-methylpropyl, 1,1-diethylpropyl, 1,1-dimethylbutyl, 1-ethyl-1 -Methylbutyl, 1,1,3,3-tetramethylbutyl, 1,1,4-trimethylpentyl, 1,1,2-trimethylpropyl, 1,1-dimethyloctyl, 1,1-dimethylpentyl, 1, 1-Dimethylheptyl, 1,1,5-trimethylhexyl, 1-ethyl-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. are mentioned. Of these, t-butyl and t-amyl are preferred.

As a substituent in the polycyclic aromatic compound having a structure containing the structural unit represented by formula (1), the substituent represented by formula (A30) is also preferable.

In formula (A30),

Ak is hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted cycloalkyl, or substituted or unsubstituted cycloalkenyl, and in the alkyl, cycloalkyl and cycloalkenyl, at least One -CH ₂ - may be substituted with -O- or -S-;

R ^Ak is substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted alkyl or substituted or unsubstituted cycloalkyl, and R ^Ak may be bonded to Ak via a linking group or a single bond. , * is a binding position.

In formula (A30), because Ak is the above substituent, since it does not conjugate with the unshared electron pair on N, the unshared electron pair can be conjugated with the π electron of the bonding site, and compared to the case where aryl etc. are present at the same position, more Large wavelength changes are possible. In addition, the same applies to the effect on the multiple resonance effect, and a greater improvement in thermally activated delayed fluorescence (TADF) properties is possible.

R ^Ak is aryl which may be substituted with alkyl or cycloalkyl, heteroaryl which may be substituted with alkyl or cycloalkyl, preferably alkyl or cycloalkyl, aryl which may be substituted with alkyl, hetero which may be substituted with alkyl It is more preferably aryl, alkyl or cycloalkyl, even more preferably aryl which may be substituted with alkyl, and particularly preferably phenyl which may be substituted with methyl.

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

R ^Ak and Ak may be the same or different, and different ones are preferable.

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

In each of the above formulas, * is a binding position.

The structural steric hindrance of the substituent of the compound used as a dopant (assisting dopant or emitting dopant) such as a polycyclic aromatic compound having a structure including the structural unit represented by Formula (1), electron donating property, and electron withdrawing property , the emission wavelength can be adjusted. It is preferably a group represented by the following structural formula, more preferably methyl, t-butyl, t-amyl, t-octyl, neopentyl, adamantyl, phenyl, o-tolyl, p-tolyl, 2, 4-xylyl, 2,5-xylyl, 2,6-xylyl, 2,4,6-mesityl, diphenylamino, di-p-tolylamino, bis(p-(t-butyl)phenyl) amino, carbazolyl, 3,6-dimethylcarbazolyl, 3,6-di-t-butylcarbazolyl and phenoxy, even more preferably methyl, t-butyl, t-amyl, t- Octyl, neopentyl, adamantyl, phenyl, o-tolyl, 2,6-xylyl, 2,4,6-mesityl, diphenylamino, di-p-tolylamino, bis(p-(t-butyl ) phenyl) amino, carbazolyl, 3,6-dimethylcarbazolyl and 3,6-di-t-butylcarbazolyl. From the viewpoint of ease of synthesis, a higher steric hindrance is preferred for selective synthesis. Specifically, t-butyl, t-amyl, t-octyl, adamantyl, o-tolyl, p-tolyl, 2, 4-xylyl, 2,5-xylyl, 2,6-xylyl, 2,4,6-mesityl, di-p-tolylamino, bis(p-(t-butyl)phenyl)amino, 3, 6-dimethylcarbazolyl and 3,6-di-t-butylcarbazolyl are preferred.

In the following structural formula, * represents a binding position.

The polycyclic aromatic compound having a structure including the structural unit represented by formula (1) is tertiary alkyl (t-butyl or t-amyl, etc.), neopentyl or adamantyl represented by formula (tR) described above. It is preferably a structure containing at least one, and preferably includes a tert-alkyl (t-butyl or t-amyl, etc.) represented by the formula (tR). This is because the luminescence quantum yield (PLQY) is improved because the intermolecular distance is increased by such a bulky substituent. Moreover, as a substituent, diarylamino is also preferable. Furthermore, diarylamino substituted with a group of formula (tR), carbazolyl (preferably N-carbazolyl) substituted with a group of formula (tR), or benzocarbazolyl substituted with a group of formula (tR) ( Preferably, N-benzocarbazolyl) is also preferred. Examples of substitution forms of groups represented by the formula (tR) in diarylamino, carbazolyl and benzocarbazolyl include examples in which some or all hydrogens of the aryl ring or benzene ring in these groups are substituted with groups represented by the formula (tR) can

In Formula (1), the substituent represented by the following formula (A20) may be sufficient as the substituent of the aryl ring or heteroaryl ring in A ring, B ring, and C ring.

The substituent represented by formula (A20) is bonded to two atoms adjacent to each other on the ring of the aryl ring or heteroaryl ring at two * points,

In formula (A20), L is >NR, >O, >Si(-R) ₂ or >S, wherein R of >NR is substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or Unsubstituted alkyl or substituted or unsubstituted cycloalkyl, wherein R in >Si(-R) ₂ is hydrogen, optionally substituted aryl, optionally substituted alkyl or optionally substituted cycloalkyl, and a linking group In addition, at least one of R in the >NR and >Si(-R) ₂ is a linking group or a single bond in the group consisting of the A ring, the B ring, R ^XC and R ^A It may be combined with at least one selected,

r is an integer from 1 to 4;

Each R ^A is independently hydrogen, substituted or unsubstituted alkyl, or substituted or unsubstituted cycloalkyl, and any R ^A may be bonded to another arbitrary R ^A through a linking group or a single bond.

As an example of said substituent, the substituent represented by any one of the following is mentioned.

In each formula, what is necessary is just to couple|bond with two or three consecutive (adjacent) atoms in the ring of any aryl ring or heteroaryl ring of ring A, B ring, and C ring by *.

<Cycloalkane Condensation>

At least one selected from the group consisting of an aryl ring and a heteroaryl ring in a polycyclic aromatic compound having a structure containing a structural unit represented by Formula (1) may be condensed with at least one cycloalkane. Formula (2A), Formula (2B), Formula (2C), Formula (2D), Formula (2E), Formula (2F), Formula (2G), Formula (2H), Formula (2I), Formula (2J), The same applies to polycyclic aromatic compounds having a structure including a structural unit represented by any one formula selected from the group consisting of formula (2K), and the following description applies to polycyclic aromatic compounds represented by any of these formulas as well. Applied.

As the cycloalkane, a cycloalkane having 3 to 24 carbon atoms may be used. At least one hydrogen in the cycloalkane at this time may be substituted with an aryl of 6 to 30 carbon atoms, a heteroaryl of 2 to 30 carbon atoms, an alkyl of 1 to 24 carbon atoms, or a cycloalkyl of 3 to 24 carbon atoms, and At least one -CH ₂ - in the cycloalkane may be substituted with -O-.

Cycloalkane is a cycloalkane having 3 to 20 carbon atoms, and at least one hydrogen in the cycloalkane is aryl having 6 to 16 carbon atoms, heteroaryl having 2 to 22 carbon atoms, alkyl having 1 to 12 carbon atoms, or carbon atoms 3 to 16. It is preferable that it is a cycloalkane which may be substituted by 16-cycloalkyl.

Examples of "cycloalkanes" 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, and cycloalkanes having 5 to 8 carbon atoms. cycloalkanes, cycloalkanes having 5 to 6 carbon atoms, cycloalkanes having 5 carbon atoms, and the like.

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

Among these, at least one carbon at the α position of a cycloalkane (the carbon at a position adjacent to the carbon at the condensation site in a cycloalkyl condensed to an aryl ring or heteroaryl ring) as shown in the following structural formula, for example. A structure having a substituent is preferred, a structure having two substituents on the α-position carbon is more preferred, and a structure in which both of the two α-position carbons have two substituents (having a total of 4 substituents) is even more preferred do. As this substituent, C1-C5 alkyl (especially methyl), halogen (especially fluorine), heavy hydrogen, etc. are mentioned. In particular, it is preferable to have a structure in which a partial structure represented by the following formula (B) is bonded to an adjacent carbon atom in an aryl ring or heteroaryl ring.

In Formula (B), * represents a bonding position.

The number of cycloalkanes condensed to one aryl ring or heteroaryl ring is preferably 1 to 3, more preferably 1 or 2, still more preferably 1. For example, an example in which one or a plurality of cycloalkanes are condensed to one benzene ring (phenyl) is shown below. * represents a bonding position, and the position may be any of carbons constituting a benzene ring and not constituting a cycloalkane. Condensed cycloalkanes may condense as shown in formulas (Cy-1-4) and (Cy-2-4). The same applies even when the ring (group) to be condensed is an aryl ring or heteroaryl ring other than a benzene ring (phenyl), and even when the cycloalkane to be condensed is a cycloalkane other than cyclopentane or cyclohexane.

At least one -CH ₂ - in the cycloalkane may be substituted with -O-. For example, an example in which one or a plurality of -CH ₂ - in a cycloalkane condensed to one benzene ring (phenyl) is substituted with -O- is shown below. The same applies even when the ring (group) to be condensed is an aryl ring or heteroaryl ring other than a benzene ring (phenyl), and even when the cycloalkane to be condensed is a cycloalkane other than cyclopentane or cyclohexane.

Cycloalkane may be substituted with at least one substituent, and any one substituent selected from the substituent group Z is mentioned as this substituent. Among these substituents, alkyl (eg, alkyl having 1 to 6 carbon atoms) and cycloalkyl (eg, cycloalkyl having 3 to 14 carbon atoms) are preferable. It is also preferable that either hydrogen is substituted with halogen (for example, fluorine) or heavy hydrogen. In addition, when cycloalkyl is substituted, the substitution form which forms a spiro structure may be sufficient, For example, the example in which the spiro structure was formed in the cycloalkane condensed to one benzene ring (phenyl) is shown below. * in each structural formula means a benzene ring contained in the skeleton structure of a compound in the case of a benzene ring, and means a bond substituted in the skeleton structure of a compound in the case of a phenyl.

As a form of cycloalkane condensation, first, the aryl ring and heteroaryl ring in each of the A ring, B ring and C ring in the polycyclic aromatic compound having a structure containing the structural unit represented by formula (1) are cycloalkane condensed form.

As another form of cycloalkane condensation, a polycyclic aromatic compound having a structure including the structural unit represented by formula (1) is, for example, >NR X , where R ^X is an aryl condensed with cycloalkane >NR ^X , condensed with cycloalkane Diarylamino (condensed to this aryl moiety), carbazolyl condensed with cycloalkane (condensed to this benzene ring moiety), or benzocarbazolyl condensed with cycloalkane (condensed to this benzene ring moiety). can be heard

Moreover, the form in which the aryl ring or heteroaryl ring in the group represented by formula (1R) was condensed with a cycloalkane is mentioned.

In addition, by introducing a cycloalkane structure into the polycyclic aromatic compound of the present invention, a decrease in melting point or sublimation temperature can be expected. This means that thermal decomposition of the material can be avoided because it can be purified at a relatively low temperature in sublimation purification, which is almost indispensable as a method for purifying materials for organic devices such as organic EL elements requiring high purity. In addition, this also applies to the vacuum deposition process, which is an effective means for manufacturing organic devices such as organic EL elements, and since the process can be carried out at a relatively low temperature, thermal decomposition of materials can be avoided and, as a result, high-performance organic devices can be obtained. can In addition, since the introduction of the cycloalkane structure improves the solubility in organic solvents, it becomes possible to apply it to device fabrication using a coating process. However, the present invention is not particularly limited to this principle.

<Substitution with heavy hydrogen, cyano or halogen>

Deuterium, cyano, or halogen may be sufficient as all or part of the hydrogen in the structure containing the structural unit represented by Formula (1). Formula (2A), Formula (2B), Formula (2C), Formula (2D), Formula (2E), Formula (2F), Formula (2G), Formula (2H), Formula (2I), Formula (2J), And the polycyclic aromatic compound having a structure including a structural unit represented by any one formula selected from the group consisting of formula (2K) is also the same, and the following description is formula (2A), formula (2B), formula (2C) ), any one selected from the group consisting of formula (2D), formula (2E), formula (2F), formula (2G), formula (2H), formula (2I), formula (2J), and formula (2K) The same applies to polycyclic aromatic compounds represented by the formula of

For example, in the structure containing the structural unit represented by formula (1), A ring, B ring, C ring (A to C ring is an aryl ring or heteroaryl ring), substituents on A to C rings, and , when X is >NR ^X , >C(-R ^X ) ₂ , or >Si(-R ^X ) ₂ , hydrogen in R ^X (=alkyl, cycloalkyl, aryl, or heteroaryl) is deuterium; It may be substituted with cyano or halogen, and among these, an embodiment in which all or part of hydrogen in an aryl or heteroaryl is substituted with deuterium, cyano, or halogen may be mentioned. Halogen is fluorine, chlorine, bromine or iodine, preferably fluorine, chlorine or bromine, more preferably fluorine or chlorine, and still more preferably fluorine. Moreover, it is also preferable that all or part of the hydrogen in the structure containing the structural unit represented by Formula (1) is deuterated from a durable viewpoint.

<Specific examples of polycyclic aromatic compounds of the present invention>

Examples of polycyclic aromatic compounds of the present invention include compounds represented by any one of the following structural formulas.

The benzene ring in the following structural formula is each independently an aryl of 6 to 16 carbon atoms, an alkyl of 1 to 5 carbon atoms or a cycloalkyl of 5 to 10 carbon atoms which may be substituted with an alkyl of 1 to 5 carbon atoms or a cycloalkyl of 5 to 10 carbon atoms. Heteroaryl of 2 to 20 carbon atoms which may be substituted with, diarylamino which may be substituted with alkyl of 1 to 5 carbon atoms or cycloalkyl of 5 to 10 carbon atoms (wherein aryl is aryl of 6 to 10 carbon atoms), 1 to 5 carbon atoms diarylboryl which may be substituted with alkyl of 5 or cycloalkyl of 5 to 10 carbon atoms (provided that aryl is aryl of 6 to 10 carbon atoms, and two aryls may be bonded by a single bond or a linking group), carbon atoms of 5 to 10 at least selected from the group consisting of alkyl having 1 to 12 carbon atoms which may be substituted with cycloalkyl of 10 carbon atoms and cycloalkyl having 3 to 16 carbon atoms which may be substituted with alkyl having 1 to 5 carbon atoms or cycloalkyl having 5 to 10 carbon atoms; It may be substituted with one substituent.

At least one hydrogen in the structure represented by the above structural formula may be substituted with heavy hydrogen, cyano or halogen.

More specific examples of the polycyclic aromatic compound of the present invention include compounds represented by any one of the following structural formulas.

<Description of High Molecularization of Polycyclic Aromatic Compounds>

A polycyclic aromatic compound having a structure composed of one or two or more structural units represented by formula (1) is a polymer compound obtained by polymerizing a reactive compound in which a reactive substituent has been substituted thereto as a monomer (for obtaining this polymer compound The monomer has a polymerizable substituent), or a polymeric crosslinked product obtained by further crosslinking the corresponding polymeric compound (the polymeric compound to obtain the polymeric crosslinked product has a crosslinkable substituent), or a main chain polymer and the reactive compound A pendant-type polymer compound reacted (the reactive compound for obtaining this pendant-type polymer compound has a reactive substituent), or a pendant-type polymer crosslinked product obtained by further crosslinking the pendant-type polymer compound (obtaining this pendant-type polymer crosslinked product) The pendant type polymer compound has a crosslinkable substituent), which can also be used for materials for organic devices, for example, materials for organic electroluminescent devices, materials for organic field effect transistors, materials for organic thin film solar cells, or wavelength conversion filters. can

In the present specification, a “polymer compound” means a polymer having a molecular weight distribution and having a number average molecular weight in terms of polystyrene of 1×10 ^{3 to} 1×10 ⁸ (1×10^3 to 1×10^8). means The number average molecular weight (Mn) of the polymer compound in terms of polystyrene can be obtained by size exclusion chromatography (SEC) using tetrahydrofuran as a 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 was 1.0 mL/min, and PLgelMIXED_B (manufactured by Polymer Laboratories) was used as the column. As the detector, a UV_VIS detector (Toso, trade name: UV-8320GPC) can be used.

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

As the above-mentioned reactive substituent (including the polymerizable substituent, the crosslinkable substituent, and a reactive substituent for obtaining a pendant-type polymer, hereinafter also simply referred to as a "reactive substituent"), the polycyclic aromatic compound can be made high in molecular weight. It is not particularly limited as long as it is a substituent that is present, a substituent capable of further crosslinking the polymer compound thus obtained, and a substituent capable of pendant reaction with the main chain polymer, but the substituent having the following structure is preferable. * in each structural formula represents a bonding position.

L is, each independently, a single bond, -O-, -S-, >C=O, -O-C(=O)-, C1-C12 alkylene, C1-C12 oxyalkylene, and C1 It is a polyoxyalkylene of ~12. Among the above 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 preferable. and a group represented by formula (XLS-1), formula (XLS-3) or formula (XLS-17) is more preferred.

Such high molecular compounds, crosslinked polymers, pendant type polymer compounds, and crosslinked pendant type polymers, in addition to repeating units of polycyclic aromatic compounds having a structure consisting of one or two or more structural units represented by Formula (1), 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 Selected from the group consisting of unsubstituted tetraphenylsilane, substituted or unsubstituted spirofluorene, substituted or unsubstituted triphenylphosphine, substituted or unsubstituted dibenzothiophene, and substituted or unsubstituted dibenzofuran You may also include at least 1 sort(s) which becomes it as a repeating unit.

As a substituent in these repeating units, for example, aryl, heteroaryl, diarylamino, diheteroarylamino, arylheteroarylamino, diarylboryl (two aryls may be bonded through a single bond or a linking group ), alkyl, cycloalkyl, alkoxy, aryloxy, triarylsilyl, trialkylsilyl, tricycloalkylsilyl, dialkylcycloalkylsilyl, or alkyldicycloalkylsilyl. The "aryl" of triarylamine and the details of these substituents can be cited from the description of a polycyclic aromatic compound having a structure composed of one or two or more structural units represented by Formula (1).

Details of the use of such a polymer compound, polymer crosslinked product, pendant type polymer compound, and pendant type polymer crosslinked product (hereinafter, simply referred to as "polymer compound and polymer crosslinked product") will be described later.

<Method for producing polycyclic aromatic compound>

A polycyclic aromatic compound having a structure composed of one or two or more structural units represented by Formula (1) basically first comprises an A ring (a ring), a B ring (b ring), and a C ring (c ring). by linking with a linking group (group containing X) and a single bond to prepare an intermediate (first reaction), then containing ring A (ring a), ring B (ring b) and ring C (ring c) The final product can be prepared by bonding the condensed ring with boron (second reaction). In the first reaction, for example, in the case of an etherification reaction, a general reaction such as a nucleophilic substitution reaction or a Ullmann reaction can be used, and in the case of an amination reaction, a general reaction such as a Birchwald-Hartwig reaction, a nucleophilic substitution reaction, or a Goldberg amination is available. In addition, in the second reaction, a tandem hetero Friedel Crafts reaction (continuous aromatic electron transfer reaction, hereinafter the same) can be used.

As shown in scheme (1) below, the second reaction is a reaction for introducing boron that bonds rings A (ring a), ring B (ring b) and ring C (ring c). First, a halogen atom between X ¹ and a nitrogen atom is halogen-metal exchanged with n-butyllithium, sec-butyllithium or t-butyllithium. Then, boron trichloride, boron tribromide, etc. are added to perform metal exchange of lithium-boron, and then a Bronsted base such as N,N-diisopropylethylamine is added to cause a tandem Bora Friedel Crafts reaction , the target can be obtained. In the second reaction, a Lewis acid such as aluminum trichloride may be added to promote the reaction. In the formula of the intermediate of scheme (1) below, the halogen atom representing Cl may be F, Br, or I, and the halogen atom can be appropriately selected in consideration of the reactivity of the substrate.

In addition, the above scheme (1) mainly shows a method for producing a polycyclic aromatic compound represented by formula (1), but for a compound having a structure composed of two or more structural units represented by formula (1), a plurality of It can be produced by using an intermediate having A ring (a ring), B ring (b ring) and C ring (c ring).

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

Specific examples of the solvent used in the above reaction are t-butylbenzene, xylene, and the like.

In addition, in the synthesis method of the scheme (1), before adding boron trichloride, boron tribromide, etc., a halogen atom between X ¹ and a nitrogen atom is halogen-metal exchanged with butyllithium or the like, resulting in a tandem hetero Friedel Crafts reaction As an example, the reaction can also be advanced by adding boron trichloride or boron tribromide to a precursor in which halogen has become hydrogen.

In addition, as the ortho-metalation reagent used in the scheme (1), alkyllithium such as methyllithium, n-butyllithium, sec-butyllithium, t-butyllithium, lithium diisopropylamide, lithium tetramethylpiperidide , organic alkali metal compounds such as lithium hexamethyldisilazide and potassium hexamethyldisilazide.

In addition, as the metal-boron metal exchange reagent used in the scheme (1), boron halides such as boron trifluoride, boron trichloride, boron tribromide and boron triiodide, boron alkoxides, and boron aryloxides etc. can be mentioned.

In addition, as the Bronsted base used in the scheme (1), N,N-diisopropylethylamine, triethylamine, 2,2,6,6-tetramethylpiperidine, 1,2,2, 6,6-pentamethylpiperidine, N,N-dimethylaniline, N,N-dimethyltoluidine, 2,6-lutidine, sodium tetraphenylborate, potassium tetraphenylborate, triphenylborane, tetraphenylsilane, Ar ₄ BNa, Ar ₄ BK, Ar ₃ B, Ar ₄ Si (Ar is aryl such as phenyl), and the like.

As Lewis acids used in the scheme (1), AlCl ₃ , AlBr ₃ , AlF ₃ , BF ₃ OEt ₂ , BCl ₃ , BBr ₃ , BI ₃ , GaCl ₃ , GaBr ₃ , InCl ₃ , InBr ₃ , In( OTf) ₃ , SnCl ₄ , SnBr ₄ , AgOTf, ScCl ₃ , Sc(OTf) ₃ , ZnCl ₂ , ZnBr ₂ , Zn(OTf) ₂ , MgCl ₂ , MgBr ₂ , Mg(OTf) ₂ , LiOTf, NaOTf, KOTf , Me ₃ SiOTf, Cu(OTf) ₂ , CuCl ₂ , YCl ₃ , Y(OTf) ₃ , TiCl ₄ , TiBr ₄ , ZrCl ₄ , ZrBr ₄ , FeCl ₃ , FeBr ₃ , CoCl ₃ , CoBr ₃ and the like. there is.

In the scheme (1), a Bronsted base or a Lewis acid may be used to promote the tandem hetero Friedel Crafts reaction. However, when boron halides such as boron trifluoride, boron trichloride, boron tribromide, and boron triiodide are used, along with the progress of the aromatic electron transfer reaction, acids such as hydrogen fluoride, hydrogen chloride, hydrogen bromide, and hydrogen iodide The use of Bronsted bases to capture acids is effective. On the other hand, when an aminated halide of boron or an alkoxide of boron is used, amines and alcohols are formed as the aromatic electron transfer reaction progresses, so in most cases it is not necessary to use a Bronsted base, Since the ability of amino or alkoxy to leave is low, it is effective to use a Lewis acid that promotes the detachment.

The polycyclic aromatic compounds of the present invention also include those in which at least a part of the hydrogen atoms are substituted with deuterium or those in which halogens such as fluorine or chlorine are substituted. By using raw materials, it can be synthesized in the same way as above.

2. Organic Device

The polycyclic aromatic compound of the present invention can be used as a material for organic devices. As an organic device, an organic electroluminescent element, an organic field effect transistor, or an organic thin-film solar cell etc. are mentioned, for example. The polycyclic aromatic compound of the present invention is preferably used as a material for forming one or more arbitrary organic layers in an organic electroluminescent device.

2-1. organic electroluminescent device

2-1-1. Structure of organic electroluminescent device

1 is a schematic cross-sectional view showing an example of an organic EL element.

An organic EL device 100 shown in FIG. 1 includes a substrate 101, an anode 102 provided on the substrate 101, a hole injection layer 103 provided on the anode 102, and a hole injection layer. The hole transport layer 104 provided on 103, the light emitting layer 105 provided on the hole transport layer 104, the electron transport layer 106 provided on the light emitting layer 105, and the electrons provided on the electron transport layer 106 It has an injection layer (107) and a cathode (108) provided on the electron injection layer (107).

In addition, the organic EL element 100 is manufactured by reversing the manufacturing order, for example, the substrate 101, the cathode 108 provided on the substrate 101, and the electron injection layer provided on the cathode 108 ( 107), an electron transport layer 106 provided on the electron injection layer 107, a light emitting layer 105 provided on the electron transport layer 106, a hole transport layer 104 provided on the light emitting layer 105, and a hole transport layer It is good also as a structure which has the hole injection layer 103 provided on (104), and the anode 102 provided on the hole injection layer 103.

It is not necessary to have all of the above layers, and the minimum structural unit is composed of an anode 102, a light emitting layer 105, and a cathode 108, and a hole injection layer 103, a hole transport layer 104, and an electron transport layer 106 ), the electron injection layer 107 is an arbitrarily provided layer. In addition, each said layer may consist of a single layer, respectively, and may consist of multiple layers.

As an aspect of the layer constituting the organic EL element, in addition to the constitutional aspect of the above-described "substrate/anode/hole injection layer/hole transport layer/light emitting layer/electron transport layer/electron injection layer/cathode", "substrate/anode/hole transport layer/ Emitting layer/electron transport layer/electron injection layer/cathode", "substrate/anode/hole injection layer/emission layer/electron transport layer/electron injection layer/cathode", "substrate/anode/hole injection layer/hole transport layer/emission layer/electron injection layer" / cathode", "substrate/anode/hole injection layer/hole transport layer/emission layer/electron transport layer/cathode", "substrate/anode/emission layer/electron transport layer/electron injection layer/cathode", "substrate/anode/hole transport layer/emission layer" /electron injection layer/cathode", "substrate/anode/hole transport 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”, or “substrate/anode/light emitting layer/electron injection layer/cathode” may be used.

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 shallower than that of the light emitting layer and a HOMO close to that of the light emitting layer or the hole transport layer, and is disposed between the light emitting layer and the hole transport layer. Since electrons stay in the light emitting layer and do not leak out to the hole transport layer, shortening of the life due to deterioration of the hole transport layer and decrease in efficiency due to reduction in recombination efficiency can be prevented. The hole blocking layer has a HOMO deeper than that of the light emitting layer and a LUMO close to that of the light emitting layer or the hole transporting layer, and is disposed between the light emitting layer and the electron transporting layer. Since holes stay in the light emitting layer and do not leak out to the electron transport layer, shortening of the life due to deterioration of the electron transport layer and decrease in efficiency due to 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.

The organic EL element may further have a high T1 layer. The high T1 layer has a T1 higher than that of the host compound, assisting dopant compound or emitting dopant compound used in the light emitting layer, and is disposed 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 emission mechanism of the device, but has a higher T1 than the compound used for the host. By having a high T1 layer around the light emitting layer, the triplet energy is confined and the triplet energy, which normally does not lead to light emission in fluorescent molecules, is converted into singlet energy, so that high efficiency can be obtained. The hole injection/transport layer or the electron blocking layer may serve as the high T1 layer. The electron injection/transport layer or the hole blocking layer may serve as the high T1 layer.

2-1-2. Substrates in organic electroluminescent devices

The substrate 101 is a support for the organic EL element 100, and usually quartz, glass, metal, plastic or the like is used. The substrate 101 is formed in the shape of a plate, film, or sheet depending on the purpose, and for example, a glass plate, a metal plate, a metal foil, a plastic film, a plastic sheet, or the like is used. Especially, a glass plate and a board made of transparent synthetic resins, such as polyester, polymethacrylate, polycarbonate, and polysulfone, are preferable. In the case of a glass substrate, soda-lime glass, non-alkali glass, etc. are used, and the thickness should just have enough thickness to maintain mechanical strength. In addition, a gas barrier film such as a dense silicon oxide film may be formed on at least one side of the substrate 101 to improve gas barrier properties, and in particular, a plate, film or sheet made of synthetic resin having low gas barrier properties is used as the substrate. When using in (101), it is preferable to form a gas barrier film.

2-1-3. Anode in organic electroluminescent device

The anode 102 serves to inject holes into the light emitting layer 105 . In addition, 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 them. do.

Materials forming the anode 102 include inorganic compounds and organic compounds. Examples of the inorganic compound include metals (aluminum, gold, silver, nickel, palladium, chromium, etc.), metal oxides (indium oxide, tin oxide, indium-tin oxide (ITO), indium-zinc oxide (IZO)) etc.), metal halides (such as copper iodide), copper sulfide, carbon black, ITO glass and Nessa glass. As an organic compound, conductive polymers, such as polythiophene, such as poly(3-methylthiophene), polypyrrole, and polyaniline, etc. are mentioned, for example. In addition, it can be used suitably selected from materials used as anodes of organic EL elements.

2-1-4. Hole injection layer and hole transport layer in an organic electroluminescent device

The hole injection layer 103 serves to efficiently inject holes moving from the anode 102 into the light emitting layer 105 or into the hole transport layer 104 . The hole transport layer 104 serves to efficiently transport holes injected from the anode 102 or holes injected from the anode 102 through the hole injection layer 103 to the light emitting layer 105 . The hole injection layer 103 and the hole transport layer 104 are formed by laminating or mixing one type or two or more types of hole injection/transport materials, respectively. Alternatively, a layer may be formed by adding an inorganic salt such as iron (III) chloride to the hole injection/transport material.

As the hole injection/transport material, it is necessary to efficiently inject/transport holes from the positive electrode between electrodes to which an electric field is applied, and it is preferable to have high hole injection efficiency and efficiently transport the injected holes. For this purpose, it is preferable to use a material that has a small ionization potential, a high hole mobility, excellent stability, and is difficult to generate trap impurities during production and use.

As the material forming the hole injection layer 103 and the hole transport layer 104, in the photoconductive material, a compound conventionally used as a hole charge transport material, a p-type semiconductor, a hole injection layer of an organic EL device, and a hole Any compound may be selected and used from known compounds used in the transport layer. 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 aromatic tertiary aminos in the main or side chains, 1,1-bis(4-di-p-tolylaminophenyl)cyclohexane, N,N'-diphenyl-N,N'-di (3-methylphenyl)-4,4'-diaminobiphenyl, N,N'-diphenyl-N,N'-dinaphthyl-4,4'-diaminobiphenyl, N,N'-diphenyl -N,N'-di(3-methylphenyl)-4,4'-diphenyl-1,1'-diamine, N,N'-dinaphthyl-N,N'-diphenyl-4,4'- Diphenyl-1,1'-diamine, N ⁴ ,N ^4' -diphenyl-N ⁴ ,N ^4' -bis(9-phenyl-9H-carbazol-3-yl)-[1,1'-bi Phenyl]-4,4'-diamine, N ⁴ ,N ⁴ ,N ^4' ,N ^4' -tetra[1,1'-biphenyl]-4-yl)-[1,1'-biphenyl]- Triphenylamine derivatives such as 4,4'-diamine, 4,4',4"-tris(3-methylphenyl(phenyl)amino)triphenylamine, starburstamine derivatives, etc.), stilbene derivatives, phthalocyanine derivatives (no metals, copper phthalocyanine, etc.), pyrazoline derivatives, hydrazone-based compounds, benzofuran derivatives or thiophene derivatives, oxadiazole derivatives, quinoxaline derivatives (e.g., 1,4,5,8,9,12-hexaaza triphenylene-2,3,6,7,10,11-hexacarbonitrile, etc.), heterocyclic compounds such as porphyrin derivatives, polysilanes, etc. In the polymer system, polycarbonates or styrene derivatives having the above monomers in their side chains , polyvinylcarbazole, polysilane, etc. are preferable, but it is not particularly limited as long as it is a compound capable of forming a thin film necessary for manufacturing a light emitting device, injecting holes from an anode, and transporting holes.

It is also known that the conductivity of an organic semiconductor is strongly influenced by its doping. Such an organic semiconductor matrix material is composed of a compound having good electron donating property or a compound having good electron accepting property. For doping of electron donor materials, strong electron acceptors such as tetracyanoquinonedimethane (TCNQ) or 2,3,5,6-tetrafluorotetracyano-1,4-benzoquinonedimethane (F4TCNQ) are used. known (see, for example, M. Pfeiffer, A. Beyer, T. Fritz, K. Leo, Appl. Phys. Lett., 73(22), 3202-3204 (1998) and J. Blochwitz , M. Pfeiffer, T. Fritz, K. Leo, Appl. Phys. Lett., 73(6), 729-731 (1998)). These generate so-called holes by an electron transfer process in an electron donating base material (hole transport material). Depending on the number and mobility of holes, the conductivity of the base material varies considerably. As matrix materials having hole transport properties, for example, benzidine derivatives (TPD, etc.) or starburstamine derivatives (TDATA, etc.), or specific metal phthalocyanines (particularly, zinc phthalocyanine (ZnPc), etc.) are known (Japanese Patent Publication) Publication No. 2005-167175).

The material for the hole injection layer and the material for the hole transport layer described above are a polymer compound obtained by polymerizing a reactive compound having a reactive substituent substituted thereto as a monomer, or a crosslinked polymer thereof, or a main chain polymer and the reactive compound reacted A pendant-type polymer compound or a pendant-type polymer crosslinked product thereof can also be used for the hole layer material.

2-1-5. Light emitting layer in an organic electroluminescent device

The light-emitting layer 105 is a layer that emits light by recombination of holes injected from the anode 102 and electrons injected from the cathode 108 between electrodes to which an electric field is applied. The material for forming the light-emitting layer 105 may be a compound that is excited by recombination of holes and electrons and emits light (luminescent compound), which can form a stable thin film and has strong light emission (fluorescence) efficiency in a solid state. It is preferable that it is a compound which represents.

The light emitting layer may be a single layer or may consist of a plurality of layers, and is formed of materials for the light emitting layer (host material, dopant material), respectively. The host material and the dopant material may be of one type, a combination of a plurality of materials, or any of them. The dopant material may be included in the entire host material, or partially included, or any of them may be used. As a doping method, although it can form by the vapor-codepositing method with a host material, you may vapor-deposit simultaneously after mixing with a host material beforehand.

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

The amount of dopant material used varies depending on the type of dopant material, and may be determined according to the characteristics of the dopant material. The amount of the dopant used is preferably 0.001 to 50% by mass, more preferably 0.05 to 20% by mass, still more preferably 0.1 to 10% by mass of the total mass of the light emitting layer material. The above range is preferable in that, for example, the concentration quenching phenomenon can be prevented.

As the dopant material, you may use an emitting dopant and an assisting dopant material. As the assisting dopant material, it is preferable to use a thermally activated delayed fluorescent material. In an organic EL device using an assisting dopant material, it is preferable that the amount of the emitting dopant material used is low in concentration to prevent concentration quenching. A high concentration of the assisting dopant material is preferred from the viewpoint of the efficiency of the thermally activated delayed fluorescence device. In addition, in an organic electroluminescent device using a thermally activated delayed fluorescence assisting dopant material, in terms of the efficiency of the thermally activated delayed fluorescence mechanism of the assisting dopant material, the amount of the assisting dopant material is compared to the amount of the assisting dopant material. It is preferable that the amount used is low concentration.

In the case where an assisting dopant material is used, the standards for the amount of host material, assisting dopant material, and emitting dopant material used are 40 to 99% by mass and 59 to 1% by mass, respectively, with respect to the total mass of the material for the light emitting layer. and 20 to 0.001% by mass, preferably 60 to 95% by mass, 39 to 5% by mass, and 10 to 0.01% by mass, more preferably 70 to 90% by mass, 29 to 10% by mass, and It is 5-0.05 mass %.

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

The polycyclic aromatic compound having a structure including the structural unit represented by Formula (1) is a “thermally activated delayed phosphor”, and an organic EL device (hereinafter referred to as a “TADF device”) exhibiting thermally activated delayed fluorescence (TADF). may be used as an emitting dopant.). In the "heat-activated delayed phosphor", by reducing the energy difference between the lowest singlet excited state and the lowest triplet excited state, inverse intersystem crossing from the lowest triplet excited state to the lowest singlet excited state, which usually has a low transition probability. is generated with high efficiency, and emission from singlets (heat-activated delayed fluorescence, TADF) is expressed. In normal fluorescence emission, 75% of triplet excitons generated by current excitation pass through a thermal deactivation pathway, and therefore cannot be extracted as fluorescence. On the other hand, in TADF, all excitons can be used for fluorescence, and a highly efficient organic EL device is realized.

In general, it is considered that those with fast delayed fluorescence have excellent TADF properties. Specifically, when a light emitting material having a delayed fluorescence lifetime of 20 μsec or less is used as an emitting dopant in a light emitting device, high device efficiency and long device life can be imparted. The delayed fluorescence lifetime is preferably less than 20 μsec, more preferably 10 μsec or less, and most preferably 5 μsec or less.

Also, in general, the smaller the value of ΔE _S1T1 is, the better the TADF performance is. Also, ΔE _S1T1 is an energy difference between the lowest singlet excitation energy level (E _S1 ) and the lowest triplet excitation energy level (E _T1 ). Specifically, the value of ΔE _S1T1 is preferably 0.20 eV or less, more preferably 0.15 eV or less, and particularly preferably 0.10 eV or less.

A polycyclic aromatic compound having a structure including a structural unit represented by Formula (1) is a phenomenon in which singlet excitons are generated from a plurality of triplet excitons (triplet-triplet fusion (TTF: Triplet-Triplet Fusion)). A dopant in a TTF element, an emitting dopant in a "TADF element", an emitting dopant in a TADF element using two types of hosts, and an organic electroluminescent element using another thermally activated delayed phosphor as an assisting dopant (TAF device), or an organic electroluminescent device (phosphorescent assist device) using a phosphorescent material as an assisting dopant. From the viewpoint that the fewer materials used in the device, the easier the manufacturing. It is preferable to use as an emitting dopant of a TADF element or an emitting dopant of a TADF element using two types of hosts, and the former is more preferable.From the viewpoint of efficiency, the emitting dopant of the TAF element and the emission of the phosphorescent assist element It is preferably used as a dopant, and more preferably used as an emitting dopant for a TAF element.

<Host Material>

As the host material, condensed ring derivatives such as anthracene and pyrene, bisstyryl derivatives such as bisstyrylanthracene derivatives and distyrylbenzene derivatives, tetraphenylbutadiene derivatives, cyclopentadiene derivatives, fluorene derivatives, benzofluorene derivatives, N-phenyl carbazole derivatives, carbazonitrile derivatives, or dibenzochrysene-based compounds; and the like. Moreover, it is also preferable that some or all of the hydrogen atoms of the host material are deuterated from the viewpoint of durability. Furthermore, it is also preferable to configure the light emitting layer by combining a host compound in which some or all of the hydrogen atoms are deuterated and a dopant compound in which some or all of the hydrogen atoms are deuterated.

The lowest triplet excitation energy level (E _T1 ) of the host material is compared to the E _T1 of the dopant or assisting dopant having the highest E _T1 in the light emitting layer from the viewpoint of not inhibiting but promoting the generation of TADF in the light emitting layer. It is preferably high, and specifically, the E _T1 of the host material is preferably 0.01 eV or higher, more preferably 0.03 eV or higher, and more preferably 0.1 eV or higher than the E _T1 of the dopant or assisting dopant. more preferable than Moreover, E _T1 of the host material is preferably 2.70 eV or more, more preferably 2.73 eV or more, and still more preferably 2.80 eV or more.

A compound active in TADF may be used for the host material.

The host material may be of one kind or a combination of a plurality of them. In the case of a plurality of combinations, a combination of a hole-transporting host material and an electron-transporting host material is preferable.

It is also preferable to use a hole-transporting host material for the hole-transporting layer adjacent to the light-emitting layer, and to use an electron-transporting host material for the electron-transporting layer adjacent to the light-emitting layer. This is because carrier leakage and energy leakage from the light emitting layer to the adjacent layer are less likely to occur, and a highly efficient organic EL element can be obtained. The host material (hole-transporting host material) in the light-emitting layer and the hole-transporting layer material may be the same or different. In addition, the host material (electron-transporting host material) in the light-emitting layer and the material of the electron-transporting layer may be the same or different.

[Anthracene derivatives]

As an anthracene derivative, the description of Paragraph 0124 - 0192 of Unexamined-Japanese-Patent No. 2020-136284, and the description of Paragraph 0072 - 0257 of Unexamined-Japanese-Patent No. 2021-118354 can be referred.

Specifically, examples of the anthracene derivative include compounds represented by formula (3-H) or compounds represented by formula (3-H2).

In formula (3-H),

X and Ar ⁴ are each independently hydrogen or any one group selected from the substituent group Z, and all X and Ar ⁴ do not become hydrogen at the same time.

At least one hydrogen in the compound represented by formula (3-H) may be substituted with halogen, cyano or heavy hydrogen.

In formula (3-H2), Ar ^c is substituted or unsubstituted aryl or substituted or unsubstituted heteroaryl, R ^c is hydrogen, alkyl or cycloalkyl, Ar ¹¹ , Ar ¹² , Ar ¹³ , Ar ¹⁴ , Ar ¹⁵ , Ar ¹⁶ , Ar ¹⁷ , and Ar ¹⁸ are each independently hydrogen or any one group selected from substituent group Z, and at least one of them in the compound represented by formula (3-H2) The hydrogen in may be substituted with halogen, cyano or deuterium.

In the compound represented by formula (3-H), X is preferably a group each independently represented by formula (3-X1), formula (3-X2) or formula (3-X3), and formula (3- X1), the group represented by formula (3-X2) or formula (3-X3) bonds with the anthracene ring of formula (3-H) in *. Preferably, two Xs do not become groups represented by formula (3-X3) at the same time. More preferably, two X's do not become groups represented by formula (3-X2) at the same time.

Alternatively, a multimer (preferably a double body) may be formed by using the structure represented by formula (3-H) as a unit structure. In this case, for example, a form in which the unit structures represented by formula (3-H) are bonded to each other through X, and examples of this X include single bonds, arylene (phenylene, biphenylene, naphthylene, etc.) and heteroarylene (a group in which a pyridine ring, a dibenzofuran ring, a dibenzothiophene ring, a carbazole ring, a benzocarbazole ring, and a phenyl-substituted carbazole ring have a divalent bonding value), and the like.

The naphthylene moiety in the formulas (3-X1) and (3-X2) may be condensed with one benzene ring. The condensed structure in this way is as follows.

Ar ¹ and Ar ² are each independently hydrogen, phenyl, biphenylyl, terphenylyl, quaterphenylyl, naphthyl, phenanthryl, fluorenyl, benzofluorenyl, chrysenyl, triphenylenyl, pyre yl or a group represented by formula (A) (including carbazolyl, benzocarbazolyl and phenyl substituted carbazolyl). In addition, when Ar ¹ or Ar ² is a group represented by formula (A), the group represented by formula (A) bonds to the naphthalene ring in formula (3-X1) or formula (3-X2) at *.

Ar ³ is phenyl, biphenylyl, terphenylyl, quaterphenylyl, naphthyl, phenanthryl, fluorenyl, benzofluorenyl, chrysenyl, triphenylenyl, pyrenyl, or Formula (A) are the groups represented (including carbazolyl, benzocarbazolyl and phenyl substituted carbazolyl). In addition, when Ar ³ is a group represented by formula (A), the group represented by formula (A) bonds with a single bond represented by a straight line in formula (3-X3) in *. That is, the anthracene ring of formula (3-H) and the group represented by formula (A) bond directly.

Further, Ar ³ may have a substituent, and at least one hydrogen in Ar ³ is further selected from alkyl having 1 to 4 carbon atoms, cycloalkyl having 5 to 10 carbon atoms, phenyl, biphenylyl, terphenylyl, naphthyl, It may be substituted by phenanthryl, fluorenyl, chrysenyl, triphenylenyl, pyrenyl, or a group represented by formula (A) (carbazolyl and phenyl-substituted carbazolyl are also included). In addition, when the substituent of Ar ³ is a group represented by formula (A), the group represented by formula (A) bonds to Ar ³ in formula (3-X3) at *.

Ar ⁴ is, each independently, hydrogen, phenyl, biphenylyl, terphenylyl, naphthyl, or alkyl having 1 to 4 carbon atoms (methyl, ethyl, t-butyl, etc.) and/or cycloalkyl having 5 to 10 carbon atoms; It is preferably silyl substituted with

In addition, hydrogen in the chemical structure of the anthracene compound represented by formula (3-H) may be substituted with a group represented by formula (A). When substituted with the group represented by formula (A), the group represented by formula (A) is substituted with at least one hydrogen in the compound represented by formula (3-H) in the *.

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

In formula (A), Y is -O-, -S- or >NR ²⁹ , R ^{21 to} R ²⁸ are each independently hydrogen or any one group selected from substituent group Z, and among R ^{21 to} R ²⁸ Adjacent groups may combine with each other to form a hydrocarbon ring, aryl ring or heteroaryl ring, and R ²⁹ is hydrogen or substituted or unsubstituted aryl. In addition, at least one hydrogen in formula (A) may be substituted with halogen, cyano or heavy hydrogen.

It is preferable that Y in Formula (A) is -O-.

[Fluorene compound]

The compound represented by formula (4-H) basically functions as a host.

In formula (4-H),

R ¹ to R ¹⁰ are each independently hydrogen, aryl, heteroaryl (the heteroaryl may be bonded to the fluorene skeleton in formula (4-H) through a linking group), diarylamino, dihetero arylamino, arylheteroarylamino, alkyl, cycloalkyl, alkenyl, alkoxy or aryloxy, wherein at least one hydrogen may be substituted with aryl, heteroaryl, alkyl or cycloalkyl, and R ¹ And R ² , R ² and R ³ , R ³ and R ⁴ , R ⁵ and R ⁶ , R ⁶ and R ⁷ , R ⁷ and R ⁸ or R ⁹ and R ¹⁰ are each independently bonded to a condensed ring or spiro ring may be formed, and at least one hydrogen in the formed ring is aryl, heteroaryl (the heteroaryl may be bonded to the formed ring through a linking group), diarylamino, diheteroarylamino, arylheteroarylamino , may be substituted with alkyl, cycloalkyl, alkenyl, alkoxy or aryloxy, and at least one hydrogen in these may be substituted with aryl, heteroaryl, alkyl or cycloalkyl, in formula (4-H) At least one hydrogen in the indicated compound may be substituted with halogen, cyano or deuterium.

For the details of each group in the definition of formula (4-H), the above description of the polycyclic aromatic compound of formula (1) can be cited.

Examples of alkenyl in R ¹ to R ¹⁰ include alkenyl having 2 to 30 carbon atoms, preferably alkenyl having 2 to 20 carbon atoms, and more preferably alkenyl having 2 to 10 carbon atoms. , alkenyl having 2 to 6 carbon atoms is more preferred, and alkenyl having 2 to 4 carbon atoms is particularly preferred. Preferred alkenyls are vinyl, 1-propenyl, 2-propenyl, 1-butenyl, 2-butenyl, 3-butenyl, 1-pentenyl, 2-pentenyl, 3-pentenyl, 4-phen tenyl, 1-hexenyl, 2-hexenyl, 3-hexenyl, 4-hexenyl, or 5-hexenyl.

In addition, as a specific example of heteroaryl, any one from the compounds of formula (4-Ar1), formula (4-Ar2), formula (4-Ar3), formula (4-Ar4) or formula (4-Ar5) Monovalent group represented by removing the hydrogen atom of is also mentioned.

In formulas (4-Ar1) to (4-Ar5), Y ¹ is each independently O, S or NR, R is phenyl, biphenylyl, naphthyl, anthracenyl or hydrogen; At least one hydrogen in the structures of -Ar1) to formula (4-Ar5) may be substituted with phenyl, biphenylyl, naphthyl, anthracenyl, phenanthrenyl, methyl, ethyl, propyl, or butyl. .

These heteroaryls may be bonded to the fluorene skeleton in formula (4-H) via a linking group. That is, the fluorene skeleton in formula (4-H) and the heteroaryl may not only directly bond, but may also bond through a linking group therebetween. Examples of the linking group include phenylene, biphenylene, naphthylene, anthracenylene, methylene, ethylene, -OCH ₂ CH ₂ -, -CH ₂ CH ₂ O-, or -OCH ₂ CH ₂ O-. there is.

Further, R ¹ and R ² , R ² and R ³ , R ³ and R ⁴ , R ⁵ and R ⁶ , R ⁶ and R ⁷ , or R ⁷ and R ⁸ in the formula (4-H) are each independently bonded In the condensed ring, R ⁹ and R ¹⁰ may combine to form a spiro ring. The condensed ring formed by R ¹ to R ⁸ is a ring condensed with the benzene ring in the formula (4-H), and is an aliphatic ring or an aromatic ring. Preferably it is an aromatic ring, and a naphthalene ring, a phenanthrene ring, etc. are mentioned as a structure containing the benzene ring in Formula (4-H). The spiro ring formed by R ⁹ and R ¹⁰ is a ring that is spiro bonded to the 5-membered ring in the formula (4-H), and is an aliphatic ring or an aromatic ring. Preferably it is an aromatic ring, and a fluorene ring etc. are mentioned.

The compound represented by formula (4-H) is preferably a compound represented by the following formula (4-H-1), formula (4-H-2) or formula (4-H-3), respectively. , A compound in which the benzene ring formed by combining R ¹ and R ² in the formula (4-H) is condensed, a compound in which the benzene ring formed by combining R ³ and R ⁴ in the formula (4-H) is condensed, and the compound in the formula (4-H) -H) is a compound in which all of R ¹ to R ⁸ are not bonded.

The definitions of R 1 to R 10 in formulas (4-H-1), formulas (4-H-2) and formulas (4-H-3) correspond to corresponding ^{R 1 to} R ¹⁰ in formulas (4-H). Same as R ¹⁰ , and degree of R ¹¹ to R 14 in formulas (4-H-1) and formulas (4-H-2) Same as ^{R 1 to} R ¹⁰ in formula (4-H) do.

The compound represented by formula (4-H) is more preferably a compound represented by the following formula (4-H-1A), formula (4-H-2A) or formula (4-H-3A) , In each of formula (4-H-1), formula (4-H-2) or formula (4-H-3), R ⁹ and R ¹⁰ are bonded to form a spiro-fluorene ring.

The definitions of R ² to R ⁷ in formulas (4-H-1A), formulas (4-H-2A) and formulas (4-H-3A) are formulas (4-H-1), formulas (4- H-2) and corresponding R ² to R ⁷ in formulas (4-H-3), and R ¹¹ to R in formulas (4-H-1A) and (4-H-2A) It is the same as R ¹¹ to R ¹⁴ in the degree parent formulas (4-H-1) and (4-H-2) of ¹⁴ .

All or part of hydrogen in the compound represented by formula (4-H) may be substituted with halogen, cyano or deuterium.

More specific examples of the fluorene compound as a host include compounds represented by the following structural formulas.

[Dibenzochrysene compound]

The dibenzochrysene compound as a host is a compound represented by the following formula (5-H), for example.

In formula (5-H), R ¹ to R ¹⁶ are each independently hydrogen, aryl, or heteroaryl (the heteroaryl is bonded to the dibenzochrysene skeleton in formula (5-H) through a linking group, may be), diarylamino, diheteroarylamino, arylheteroarylamino, alkyl, cycloalkyl, alkenyl, alkoxy or aryloxy, wherein at least one hydrogen is aryl, heteroaryl, alkyl or cycloalkyl may be substituted with, and adjacent groups among R ¹ to R ¹⁶ may be bonded to each other to form a condensed ring, and at least one hydrogen in the formed ring is aryl or heteroaryl (the heteroaryl is a linking group may be bonded to the ring formed through), diarylamino, diheteroarylamino, arylheteroarylamino, alkyl, cycloalkyl, alkenyl, alkoxy, or aryloxy, and at least one hydrogen in these may be substituted may be substituted with aryl, heteroaryl, alkyl or cycloalkyl, and at least one hydrogen in the compound represented by formula (5-H) may be substituted with halogen, cyano or deuterium.

For the details of each group in the definition of formula (5-H), the above description of the polycyclic aromatic compound of formula (1) can be cited.

Examples of alkenyl in the definition of formula (5-H) include alkenyl having 2 to 30 carbon atoms, preferably alkenyl having 2 to 20 carbon atoms, and alkenyl having 2 to 10 carbon atoms. More preferably, alkenyl having 2 to 6 carbon atoms is still more preferable, and alkenyl having 2 to 4 carbon atoms is particularly preferable. Preferred alkenyls are vinyl, 1-propenyl, 2-propenyl, 1-butenyl, 2-butenyl, 3-butenyl, 1-pentenyl, 2-pentenyl, 3-pentenyl, 4-phen tenyl, 1-hexenyl, 2-hexenyl, 3-hexenyl, 4-hexenyl, or 5-hexenyl.

In addition, as a specific example of heteroaryl, any one from the compounds of formula (5-Ar1), formula (5-Ar2), formula (5-Ar3), formula (5-Ar4) or formula (5-Ar5) Monovalent group represented by removing the hydrogen atom of is also mentioned.

In formulas (5-Ar1) to (5-Ar5), Y ¹ is each independently O, S or NR, R is phenyl, biphenylyl, naphthyl, anthracenyl or hydrogen; At least one hydrogen in the structures of -Ar1) to formula (5-Ar5) may be substituted with phenyl, biphenylyl, naphthyl, anthracenyl, phenanthrenyl, methyl, ethyl, propyl, or butyl. .

These heteroaryls may be bonded to the dibenzochrysene skeleton in formula (5-H) via a linking group. That is, the dibenzochrysene skeleton in formula (5-H) and the heteroaryl may not only be bonded directly, but may also be bonded through a linking group therebetween. Examples of the linking group include phenylene, biphenylene, naphthylene, anthracenylene, methylene, ethylene, -OCH ₂ CH ₂ -, -CH ₂ CH ₂ O-, or -OCH ₂ CH ₂ O-. there is.

In the compound represented by formula (5-H), preferably, R ¹ , R ⁴ , R ⁵ , R ⁸ , R ⁹ , R ¹² , R ¹³ and R ¹⁶ are hydrogen. In this case, R ² , R ³ , R ⁶ , R ⁷ , R ¹⁰ , R ¹¹ , R ¹⁴ and R ¹⁵ in formula (5-H) are each independently hydrogen, phenyl, biphenylyl, naphthyl, Anthracenyl, phenanthrenyl, a monovalent group having a structure of formula (5-Ar1), formula (5-Ar2), formula (5-Ar3), formula (5-Ar4) or formula (5-Ar5) (corresponding The monovalent group having the structure is phenylene, biphenylene, naphthylene, anthracenylene, methylene, ethylene, -OCH ₂ CH ₂ -, -CH ₂ CH ₂ O-, or -OCH ₂ CH ₂ O- through, may be bonded to the dibenzochrysene skeleton in the formula (5-H)), methyl, ethyl, propyl, or butyl is preferable.

The compound represented by formula (5-H) is more preferably R ¹ , R ² , R ⁴ , R ⁵ , R ⁷ , R ⁸ , R ⁹ , R ¹⁰ , R ¹² , R ¹³ , R ¹⁵ and R ¹⁶ is hydrogen. In this case, at least one (preferably 1 or 2, more preferably 1) of R ³ , R ⁶ , R ¹¹ and R ¹⁴ in formula (5-H) is a single bond, phenylene, via phenylene, naphthylene, anthracenylene, methylene, ethylene, -OCH ₂ CH ₂ -, -CH ₂ CH ₂ O-, or -OCH ₂ CH ₂ O-, formula (5-Ar1), formula ( 5-Ar2), a monovalent group having a structure of formula (5-Ar3), formula (5-Ar4) or formula (5-Ar5), other than at least one of the above (ie, a monovalent group having the above structure is substituted). position) is hydrogen, phenyl, biphenylyl, naphthyl, anthracenyl, methyl, ethyl, propyl, or butyl, and at least one hydrogen in these is phenyl, biphenylyl, naphthyl, anthracenyl , methyl, ethyl, propyl, or butyl may be substituted.

Further, as R ² , R ³ , R ⁶ , R ⁷ , R ¹⁰ , R ¹¹ , R ¹⁴ and R ¹⁵ in formula (5-H), those represented by formulas (5-Ar1) to (5-Ar5) When a monovalent group having a structure is selected, at least one hydrogen in the structure may be bonded to any one of R ¹ to R ¹⁶ in the formula (5-H) to form a single bond.

More specific examples of the dibenzochrysene compound as a host include compounds represented by the following structural formulas.

[Compound represented by any one of formulas (H1), (H2) and (H3)]

As the host material, a compound represented by any one of the following formulas (H1), (H2) and (H3) can also be used, for example.

In formulas (H1), (H2) and (H3), L ¹ represents arylene having 6 to 24 carbon atoms, heteroarylene having 2 to 24 carbon atoms, heteroarylene arylene having 6 to 24 carbon atoms, and arylene having 6 to 24 carbon atoms. Arylene Heteroarylene Arylene, preferably arylene having 6 to 16 carbon atoms, more preferably arylene having 6 to 12 carbon atoms, particularly preferably arylene having 6 to 10 carbon atoms, specifically, a benzene ring , bivalent groups such as a biphenyl ring, a terphenyl ring and a fluorene ring. As the heteroarylene, heteroarylene having 2 to 24 carbon atoms is preferable, heteroarylene having 2 to 20 carbon atoms is more preferable, heteroarylene having 2 to 15 carbon atoms is still more preferable, and heteroarylene having 2 to 10 carbon atoms is more preferable. Arylene is particularly preferred, specifically, a pyrrole ring, an oxazole ring, an isoxazole ring, a thiazole ring, an isothiazole ring, an imidazole ring, an oxadiazole ring (such as a furazane ring), a thiadiazole ring, a triazole ring, and a tetrazole ring. , Pyrazole ring, pyridine ring, pyrimidine ring, pyridazine ring, pyrazine ring, triazine ring, indole ring, isoindole ring, 1H-indazole ring, benzoimidazole ring, benzooxazole ring, benzothiazole ring, 1H-benzotria Zol ring, quinoline ring, isoquinoline ring, cinnoline ring, quinazoline ring, quinoxaline ring, phthalazine ring, naphthridine ring, purine ring, pteridine ring, carbazole ring, acridine ring, phenoxathiine ring, Green ring, phenothiazine ring, phenazine ring, indolizine ring, furan ring, benzofuran ring, isobenzofuran ring, dibenzofuran ring, thiophene ring, benzothiophene ring, dibenzothiophene ring, and thianthrene ring Divalent groups, such as these, are mentioned. At least one hydrogen in the compound represented by the above formulas may be substituted with a C1-C6 alkyl, cyano, halogen or deuterium.

As a preferable specific example, the compound represented by any one of the structural formulas listed below is mentioned. In the structural formulas listed below, at least one hydrogen may be substituted with halogen, cyano, alkyl having 1 to 4 carbon atoms (for example, methyl or t-butyl), phenyl or naphthyl.

[Hole-transporting host material (HH) and electron-transporting host material (EH)]

The hole-transporting host material (HH) and the electron-transporting host material (EH) satisfy the following relationship with respect to HOMO (Highest Occupied Molecular Orbital) and LUMO (Lowest Unoccupied Molecular Orbital).

The HOMO of the hole-transporting host material (HH) is shallower than that 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).

Further, it is preferable that the HOMO of the emitting dopant is shallower than the HOMO of the hole transporting host material (HH), or the LUMO of the emitting dopant is deeper than the LUMO of the electron transporting host material (EH).

In addition, the lowest excitation triplet energy level (E _T1 ) of the hole-transporting host material (HH) and the electron-transporting host material (EH) is the highest in the light-emitting layer from the viewpoint of promoting, without hindering, the generation of TADF in the light-emitting layer. It is preferable that the E _T1 of the emitting dopant or the assisting dopant having a high E _T1 be higher than _{the E T1 of} the host material. It is preferably high, more preferably higher than 0.03 eV, and even more preferably higher than 0.1 eV. Further, E _T1 of the host material is preferably 2.47 eV or higher, more preferably 2.49 eV or higher, and still more preferably 2.56 eV or higher.

It is also preferable to use a hole-transporting host material for the hole-transporting layer adjacent to the light-emitting layer, and to use an electron-transporting host material for the electron-transporting layer adjacent to the light-emitting layer. This is because carrier leakage and energy leakage from the light emitting layer to the adjacent layer are less likely to occur, and a highly efficient organic EL element can be obtained. The host material (hole-transporting host material) in the light-emitting layer and the hole-transporting layer material may be the same or different. In addition, the host material (electron-transporting host material) in the light-emitting layer and the material of the electron-transporting layer may be the same or different.

As an example of a preferable hole-transporting host material (HH), it is represented by the formula (HH-1) or has a partial structure represented by the formula (HH-1) and is selected from the group consisting of an aryl ring and a heteroaryl ring. and compounds having a structure containing two rings. This compound preferably contains neither an imine structure (-N=C-; including a partial structure of a heteroaryl ring), boron (>B-), or cyano (CN).

In formula (HH-1),

Q is >O, >S, or >NA ^H ;

One carbon atom next to the carbon atom to be bonded to Q in each of the two phenyls in the formula (HH-1) may be bonded to each other by L,

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

A ^H is hydrogen, aryl, or heteroaryl, and two A ^Hs in >C(-A ^H ) ₂ may be bonded to each other.

When the hole-transporting host material contains the structure represented by formula (HH-1) as a partial structure, it may contain one partial structure, but it is also preferable to include two or more of these partial structures. When two or more are included, the two or more partial structures may be the same as or different from each other. Two or more partial structures may be bonded to each other by a single bond, may be bonded by sharing an arbitrary ring included in the partial structure, or may be bonded by condensing arbitrary rings included in the partial structure. The partial structure may further have a substituent selected from aryl, heteroaryl, diarylamino, or aryloxy.

The compound represented by the formula (HH-1) or having a partial structure represented by the formula (HH-1) has a structure containing at least three rings selected from the group consisting of an aryl ring and a heteroaryl ring. have It is preferable that it is 6 or more, and, as for the number of rings contained, it is more preferable that it is 8 or more. Moreover, it is preferable that it is 20 or less, it is more preferable that it is 15 or less, and it is still more preferable that it is 10 or less. The number of rings means the number as a single ring, and about a condensed ring, let it be the number which counted the single rings which comprise a condensed ring.

The hole-transporting host material contains at least one partial structure selected from the group consisting of a triarylamine structure, a carbazole ring, a dibenzofuran ring, a dibenzothiophene ring, and a condensed polycyclic ring including phenoxazine or phenothiazine. It is preferable that it is a compound which does. The hole-transporting host material may contain one such partial structure, but it is also preferable to include two or more. When two or more are included, the two or more partial structures may be the same as or different from each other.

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

Among the above, HH-1-1, HH-1-2, HH-1-4 to HH-1-12, HH-1-17, HH-1-18, HH-1-20 to HH-1-24 , HH-1-82, HH-1-84 to HH-1-89, HH-1-91, HH-1-92, HH-1-106 to HH-1-108 and HH-1-109 to HH -1-114 is preferred.

Examples of the electron transporting host material (EH) are represented by formulas (EH-1A) to (EH-1D) or have partial structures represented by formulas (EH-1A) to (EH-1D), and include an aryl ring and and compounds having a structure containing at least three rings selected from the group consisting of heteroaryl rings.

In the formulas (EH-1A) to (EH-1D),

Ar is a heteroaryl ring containing N = C as a partial structure constituting the ring,

Z is a single bond, -O-, -S-, or -N (-A ^E )-;

The carbon atom adjacent to the carbon atom to which Z is bonded and A ^E to which Z is bonded may be bonded to each other by L,

L is a single bond, >O, >S or >C(-A ^E ) ₂ ;

A ^E is aryl, heteroaryl, or triarylsilyl, and two A ^E in >C(-A ^E ) ₂ may be bonded to each other;

X is C, P or S;

When X is C, n = 2, m = 1,

When X is P, n = 3, m = 1,

When X is S, n = 2 and m = 1 to 2.

Compounds represented by the formulas (EH-1A) to (EH-1D) or having partial structures represented by formulas (EH-1A) to (EH-1D) are selected from the group consisting of aryl rings and heteroaryl rings It has a structure containing at least three rings. The number of rings contained is preferably 4 or more, more preferably 6 or more, still more preferably 8 or more. Moreover, it is preferable that it is 20 or less, it is more preferable that it is 15 or less, and it is still more preferable that it is 10 or less. The number of rings means the number as a single ring, and about a condensed ring, let it be the number which counted the single rings which comprise a condensed ring.

When the electron transporting host material contains structures represented by formulas (EH-1A) to (EH-1D) as partial structures, it may contain one partial structure, but it is also preferable to include two or more of these partial structures. When two or more are included, the two or more partial structures may be the same as or different from each other. Two or more partial structures may be bonded to each other by a single bond, may be bonded by sharing an arbitrary ring included in the partial structure, or may be bonded by condensing arbitrary rings included in the partial structure. The partial structure may further have a substituent selected from aryl, heteroaryl, diarylamino, or aryloxy.

Specific examples of the electron-transporting host material include the following compounds.

As another preferred example of the electron-transporting host material (a compound having a partial structure represented by formula (EH-1)), a polycyclic aromatic compound represented by the following formula (EH-1b) or a compound represented by the following formula (EH-1b) Multimers of polycyclic aromatic compounds having a plurality of supporting structures are exemplified.

In formula (EH-1b),

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 selected from substituent group Z.

In Formula (EH-1b), X ¹ and X ² are each independently >NR (amine nitrogen), >O, >C(-R) ₂ , >S or >Se, and X ¹ and X There is no case where all ² are >C(-R) ₂ ,

R in >NR and >C(-R) ₂ is each independently hydrogen or a substituent selected from substituent group Z, and further selected from aryl, heteroaryl, alkyl or cycloalkyl (above, second substituent) It may be substituted, and each R in >NR and >C(-R) ₂ may be independently bonded to at least one of the a, b, and c rings via a linking group or a single bond.

Y ¹ , Y ² , Y ³ , Y ⁴ , Y ⁵ and Y ⁶ (hereinafter also referred to as “Y ¹ etc.”) are each independently =C(-R)- or =N- (pyridinous nitrogen) , and at least one is =N-(pyridinic nitrogen),

R in =C(-R)- above is each independently hydrogen or a substituent selected from substituent group Z.

Among R ¹ , R ² , R ³ , R ⁴ , and R ⁵ , and R in =C(-R)- as Y ^{1 to} Y ⁶ , adjacent groups bond to each other to form ring a, ring b, and ring c. may form an aryl ring or heteroaryl ring together with at least one of the rings, and at least one hydrogen in the formed ring is aryl, heteroaryl, diarylamino, diheteroarylamino, arylheteroarylamino, diaryl It may be substituted with boryl (two aryls may be bonded through a single bond or a linking group), alkyl, cycloalkyl, alkoxy, or aryloxy (above, first substituent), and at least one hydrogen in these may be aryl , heteroaryl, alkyl or cycloalkyl (above, the second substituent) may be further substituted.

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

In the formula (EH-1b), R ¹ , R ² , R ³ , R ⁴ and R ⁵ are all hydrogen, or both R ³ and R ⁴ are hydrogen, and R ¹ , R ² and R ⁵ are also It is preferable that any one or more selected from the group which consists of is a substituent other than hydrogen, and the others are hydrogen. As the substituent, aryl which may be substituted with alkyl, alkyl or heteroaryl, heteroaryl which may be substituted with alkyl or aryl, or diarylamino which may be substituted with alkyl or aryl is preferable. At this time, the alkyl is preferably an alkyl having 1 to 6 carbon atoms (methyl, t-butyl, etc.), the aryl is preferably phenyl or biphenyl, and the heteroaryl is triazinyl, carbazolyl (2-carbazolyl , 3-carbazolyl, 9-carbazolyl, etc.), pyrimidinyl, pyridinyl, dibenzofuranyl or dibenzothienyl are preferred. Specific examples include phenyl, biphenyl, diphenyltriazinyl, carbazolyltriazinyl, monophenylpyrimidinyl, diphenylpyrimidinyl, carbazolyltriazinyl, pyridinyl, dibenzofuranyl and dibenzothienyl. can be heard

Y ¹ and the like are each independently =C(-R)- or =N-, and at least one of them is =N-. Any of Y ^{1 to} Y ⁶ may be =N-. Preferably, Y ¹ and Y ⁶ are =N-(a ring is a pyrimidine ring), Y ¹ or Y ⁶ is =N-(a ring is a pyridine ring), Y ² and Y ⁵ are =N-(b ring and ring c is a pyridine ring), Y ³ and Y ⁴ are =N- (rings b and c are pyridine rings), Y ^{2 to} Y ⁵ are =N- (rings b and c are pyrimidine rings), Y ¹ , Y ³ , Y ⁴ and Y ⁶ are =N- (ring a is a pyrimidine ring, ring b and ring c are a pyridine ring), Y ¹ , Y ² , Y ⁵ and Y ⁶ are =N- (ring a is a pyrimidine ring, ring b and c ring is a pyridine ring), Y ^{1 to} Y ⁶ is =N- (ring a, b and c are pyrimidine rings), and Y ² or Y ⁵ is =N- (ring b or c is a pyridine ring).

Further, in addition to the above arrangement relationship of =N-, it is preferable that X1 and X2 are >0, and a polycyclic aromatic compound containing a partial structure represented by any one of the following formulas is preferable.

In particular, a polycyclic aromatic compound having a partial structure represented by formula (EH-1b-N1) has higher E _S1 , higher E _T1 , and smaller ΔE _S1T1 than a structure without N.

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

Among the above, EH-1-1 to EH-1-4, EH-1-10, EH-1-21 to EH-1-25, EH-1-32, EH-1-33, EH-1-51 ~EH-1-59, EH-1-61, EH-1-66, EH-1-68, EH-1-71, EH-1-72, EH-1-90, EH-1-100, EH -1-101, EH-1-104, EH-1-115, EH-1-117, EH-1-120, EH-1-122, EH-1-123, EH-1-127~EH-1 -130 is preferred.

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

A combination of the hole-transporting host material and the electron-transporting host material is selected according to the HOMO, LUMO, and lowest excitation triplet energy level (E _T1 ) of the hole-transporting host material, the electron-transporting host material, and the dopant material.

Regarding HOMO and LUMO, 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. Select a combination, more specifically, a combination in which HOMO(HH) is 0.10 eV or more shallower than HOMO(EH), LUMO(HH) is 0.10 eV or more deeper than HOMO(EH), and HOMO(HH) is HOMO A combination in which 0.20 eV or more shallow than (EH) and LUMO (HH) is 0.20 eV or more deeper than HOMO (EH) is more preferable, HOMO (HH) is 0.25 eV or more shallow than HOMO (EH), and LUMO (HH) A combination at least 0.25 eV deeper than (EH) is more preferable.

The hole-transporting host material and the electron-transporting host material may be a combination that forms an association called an exciplex. It is generally known that exciplex is easy to form between a material having a relatively deep LUMO level and a material having a shallow HOMO level. The interaction of the hole-transporting host material and the electron-transporting host material, specifically, whether or not an exciplex is formed is determined by forming a monolayer film composed of the hole-transporting host material and the electron-transporting host material under the same conditions as the formation conditions of the light emitting layer, and emitting light. It can be judged by measuring the spectrum (fluorescence and phosphorescence spectrum) and comparing the obtained emission spectrum with the emission spectrum exhibited by each of the hole-transporting host material and the electron-transporting host material alone. It can be judged that the spectrum of the mixed film containing the hole-transporting host material and the electron-transporting host material exhibits an emission wavelength different from both the film spectrum of the hole-transporting host material and the film spectrum of the electron-transporting host material. Specifically, the index may be that the peak wavelengths of the spectra differ by 10 nm or more.

Specific examples of combinations of a hole-transporting host material and an electron-transporting host material that do not form an exciplex include the following combinations. In order to satisfy the above physical property values of HOMO, LUMO and E _T1 , in the hole-transporting host material, carbazole, dibenzofuran, dibenzothiophene, triarylamine, indolocarbazole and benzoxazinophenoxazine are partially used. A compound having as a structure is preferable, a compound having carbazole, dibenzofuran and dibenzothiophene as a partial structure is more preferable, and a compound having carbazole as a partial structure is even more preferable. Similarly, in the electron-transporting host material, compounds having pyridine, triazine, phosphine oxide, benzofuropyridine and dibenzoxacillin as partial structures are preferred, and triazine, phosphine oxide, benzofuropyridine and dibenzooxa A compound having silin as a partial structure is more preferred, and a compound having triazine is even more preferred.

More specifically, the hole transporting host material is HH-1-1, HH-1-2, HH-1-4 to HH-1-12, HH-1-17, HH-1-18, HH-1 -20 to HH-1-24, HH-1-82, HH-1-84 to HH-1-89, HH-1-91, HH-1-92, HH-1-106 to HH-1-108 And it is preferably selected from the group consisting of HH-1-109 to HH-1-114, and the electron transporting host material is 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-1-71, EH-1-72, EH-1-90, EH-1-100, EH-1-101, EH-1-104, EH-1-117, EH-1-120, EH-1-122, EH-1-123, and EH It is preferably selected from the group consisting of -1-127 to EH-1-130. Preferable 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 may be cited.

Specific examples of combinations of a hole-transporting host material and an electron-transporting host material forming an exciplex include the following combinations. In order to satisfy the above physical property values of HOMO, LUMO and E _T1 , compounds having carbazole, triarylamine, indolocarbazole and benzoxazinophenoxazine as partial structures are preferred for the hole-transporting host material. Compounds having arylamine, indolocarbazole and benzoxazinophenoxazine as partial structures are more preferred, and compounds having triarylamine as partial structures are even more preferred. Similarly, in the electron-transporting host material, compounds having pyridine, triazine, phosphine oxide, and benzofuropyridine as partial structures are preferred, and triazine, phosphine oxide, benzofuropyridine, and dibenzoxacillin as partial structures. Compounds having phosphine oxide and triazine are more preferred.

More specifically, the hole transporting host material is HH-1-1, HH-1-2, HH-1-11, HH-1-12, HH-1-17, HH-1-18, HH-1 It is preferably selected from the group consisting of -23 and HH-1-24, and the electron transporting host material is EH-1-1 to EH-1-4, EH-1-21 to EH-1-25, EH- 1-51 to EH-1-57, EH-1-59, EH-1-66, EH-1-68, EH-1-90, EH-1-100, EH-1-101, EH-1- 104, EH-1-117, EH-1-120, EH-1-122, EH-1-123, and EH-1-127 to EH-1-130. Preferable 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-1-117, compound HH- 1-1 and compound EH-1-130, compound HH-1-33 and compound EH-1-117, compound HH-1-48 and compound EH-1-117 or compound HH-1-49 and compound EH-1 -117 can be heard.

In addition, for specific combinations of hole-transporting host materials and electron-transporting host materials, Organic Electronics 66 (2019) 227-24, Advanced.Functional Materals 25 (2015) 361-366., Advanced Materials 26 (2014) 4730- 4734., ACS Applied Materials and Interfaces 8(2016)32984-32991., ACS Applied Materials and Interfaces 2016, 8, 9806-9810, ACS Applied Materials and Interfaces 2016, 8, 32984-32991, Journal of Materials Chemisty C, 2018 , 6, 8784-8792, Angewante Chemie International Edition.2018, 57, 12380-12384, Advanced Functional Materials, 24, 2014, 3970, Advanced Materials, 26, 2014, 5684, and Synthetic Metals, 201,2015, 49, etc. You can refer to the description of

<Dopant material>

Other than the polycyclic aromatic compounds of the present invention, known compounds can be used as dopant materials that can be used, and can be selected from various materials depending on the desired emission color. Specifically, for example, condensed ring derivatives such as phenanthrene, anthracene, pyrene, tetracene, pentacene, perylene, naphthopyrene, dibenzopyrene, rubrene and chrysene, benzoxazole derivatives, and benzothiazole derivatives, benzoimidazole 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, bisstyryl derivatives such as bisstyrylanthracene derivatives and distyrylbenzene derivatives (Japanese Patent Laid-Open No. 1-245087), bisstyrylarylene derivatives (Japanese Patent Laid-Open No. 2 -247278), diazaindacene derivatives, furan derivatives, benzofuran derivatives, phenyl isobenzofuran, dimethyl isobenzofuran, di(2-methylphenyl)isobenzofuran, di(2-trifluoromethylphenyl)iso Isobenzofuran derivatives such as benzofuran and phenylisobenzofuran, dibenzofuran derivatives, 7-dialkylaminocoumarin derivatives, 7-piperidinocoumarin derivatives, 7-hydroxycoumarin derivatives, 7-methoxycoumarin derivatives, 7 -Coumarin derivatives such as acetoxycoumarin derivatives, 3-benzothiazolylcoumarin derivatives, 3-benzoimidazolylcoumarin derivatives, and 3-benzooxazolylcoumarin derivatives, dicyanomethylenepyran derivatives, dicyanomethylenethiopyran derivatives, polymethine Derivatives, cyanine derivatives, oxobenzoanthracene derivatives, xanthene derivatives, rhodamine derivatives, fluorescein derivatives, pyrillium derivatives, carbostyril derivatives, acridine derivatives, oxazine derivatives, phenylene oxide derivatives, quinacridone derivatives , quinazoline derivatives, pyrrolopyridine derivatives, furopyridine derivatives, 1,2,5-thiadiazolopyrene derivatives, pyrimethene derivatives, perinone derivatives, pyrrolopyrrole derivatives, squarylium derivatives, bioranthrone derivatives, phena gin derivatives, acridone derivatives, deazaflavin derivatives, fluorene derivatives and benzofluorene derivatives; and the like.

As a 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, and Paragraphs 0097 to 0269 of Japanese Patent Application Publication No. 2021-077890 and the like.

<Assisting dopant (heat-activated delayed phosphor or phosphorescent material)>

It is also preferable that the light emitting layer contains an assisting dopant together with an emitting dopant and a host material. As the assisting dopant, a thermally activated delayed phosphor or phosphorescent material is preferable. A polycyclic aromatic compound having a structure composed of one or two or more structural units represented by Formula (1) can be preferably used as an emitting dopant in a TAF element or a PSF element.

In this aspect, a known host compound can be used, for example, a compound having at least one of a carbazole ring and a furan ring, and among them, at least one of furanyl and carbazolyl; It is preferable to use a compound in which at least one of arylene and heteroarylene is bonded. As a specific example, mCP, mCBP, etc. are mentioned. Further, a compound having TADF activity may be used as the host compound. In this aspect, it is also preferable to use a combination of a hole-transporting host material and an electron-transporting host material as the host.

The lowest excitation triplet energy level E (1, T, Sh) determined from the shoulder of the short wavelength side of the peak of the phosphorescence spectrum of the host compound is the highest in the light emitting layer from the viewpoint of promoting the generation of TADF in the light emitting layer without hindering it. It is preferably higher than the lowest excitation triplet energy level E(2, T, Sh), E(3, T, Sh) of the emitting dopant or assisting dopant having the highest lowest excitation triplet energy level, specifically, , The lowest excitation triplet energy level E(1, T, Sh) of the host compound is preferably 0.01eV or more higher than E(2, T, Sh), E(3, T, Sh), and is 0.03eV or more A high value is more preferred, and a value higher than 0.1 eV is still more preferred. Further, the lowest excitation triplet energy level E of the host material is preferably 2.70 eV or higher, more preferably 2.73 eV or higher, and still more preferably 2.80 eV or higher.

[Heat activated delayed phosphor]

"Thermally activated delayed phosphor" is a compound capable of absorbing thermal energy to cause inverse intersystem crossing from the lowest triplet excited state to the singlet excited state, and radiatively inactivating from the lowest excited singlet state to emit delayed fluorescence. means However, "heat-activated delayed fluorescence" includes high-order triplet excitation in the excitation process from the lowest triplet excited state to the lowest singlet excited state. For example, a paper by Monkmans, Durham University (NATURE COMMUNICATIONS, 7:13680, DOI:10.1038/ncomms 13680), a paper by Hosokai et al., Sci.Adv.2017;3 : e1603282), a paper by Kyoto University scholars (Scientific Reports, 7:4820, DOI:10.1038/s41598-017-05007-7), as well as a conference presentation by Kyoto University scholars (Japan Chemical Society 98th Spring Banquet, Publication number: 2I4-15, Mechanism of high-efficiency luminescence in organic electroluminescence using DABNA as a luminescent molecule, Graduate School of Engineering, Kyoto University), review by Bui et al. (DOI: 10.3762/bjoc.14.18), by Duan et al. review (DOI:10.1063/1.5143501), review by Dings (DOI:10.1088/1674-4926/42/5/050201), and review by Xies (DOI:10.1002/adom.202002204). In the present invention, when the fluorescence lifetime of a sample containing the target compound is measured at 300 K, a slow fluorescence component is observed, and the target compound is determined to be a "heat-activated delayed phosphor". Here, the slow fluorescence component refers to a fluorescence lifetime of 0.1 μsec or more. The fluorescence lifetime can be measured using, for example, a fluorescence lifetime measuring device (C11367-01 manufactured by Hamamatsu Photonics Co., Ltd.).

In the light emitting layer further containing a "heat-activated delayed phosphor" as an assisting dopant, the polycyclic aromatic compound of the present invention can function as an emitting dopant. That is, the "heat-activated delayed phosphor" can function as an assisting dopant that assists light emission of the polycyclic aromatic compound of the present invention.

In this specification, an organic electroluminescent element using a thermally activated delayed phosphor as an assisting dopant is sometimes referred to as a "TAF element" (TADF Assisting Fluorescence element).

The term "host compound" in a TAF element means a compound whose lowest excitation singlet energy level obtained from the shoulder of the short wavelength side of the peak of the fluorescence spectrum is higher than that of the thermally activated delayed phosphor as an assisting dopant and the emitting dopant. do.

FIG. 2 shows an energy level diagram of a light emitting layer of a TAF device using a general fluorescent dopant as an emitting dopant (ED). In the figure, E(1, G) is the ground state energy level of the host, E(1, S, Sh) is the lowest excitation singlet energy level obtained from the short-wavelength shoulder of the host fluorescence spectrum, and the phosphorescence spectrum of the host is The lowest excitation triplet energy level obtained from the shoulder on the short wavelength side is E(1, T, Sh), the ground state energy level of the assisting dopant is E(2, G), and the shoulder on the short wavelength side of the fluorescence spectrum of the assisting dopant The lowest excitation singlet energy level obtained from E(2, S, Sh), the lowest excitation triplet energy level obtained from the shoulder on the short wavelength side of the phosphorescence spectrum of the assisting dopant is E(2, T, Sh), The ground state energy level of the ting dopant is E(3, G), the lowest excitation singlet energy level obtained from the short-wavelength shoulder of the fluorescence spectrum of the emitting dopant is E(3, S, Sh), and the phosphorescence of the emitting dopant The lowest excitation triplet energy level obtained from the shoulder on the short wavelength side of the spectrum is E(3, T, Sh), the hole is h+, the electron is e-, and the fluorescence resonance energy transfer is FRET (Fluorescence Resonance Energy Transfer). In the TAF device, when a general fluorescent dopant is used as the emitting dopant (ED), energy upconverted from the assisting dopant moves to the lowest excitation singlet energy level E(3, S, Sh) of the assisting dopant and emits light. do. However, some lowest excitation triplet energy level E(2, T, Sh) on the assisting dopant moves to the lowest excitation triplet energy level E(3, T, Sh) of the emitting dopant, or Intersystem crossing occurs from the excitation singlet energy level E(3, S, Sh) to the lowest excitation triplet energy level E(3, T, Sh), and continues thermally to the ground state E(3, G). deactivate with A part of the energy is not used for light emission through this path, and energy is wasted.

In contrast, in the organic EL device of the present embodiment, energy transferred from the assisting dopant to the emitting dopant can be efficiently used for light emission, and thus high light emission efficiency can be realized. This is estimated to be based on the following light emission mechanism.

A preferable energy relationship in the organic electroluminescent device of the present embodiment is shown in FIG. 3 . In the organic electroluminescent device of this embodiment, a compound having a boron atom as an emitter dopant has a high lowest triplet excitation energy level E(3, T, Sh). Because of this, even when the lowest excitation singlet energy upconverted in the assisting dopant crosses intersystem to, for example, the lowest excitation triplet energy level E(3, T, Sh) in the emitting dopant, on the emitting dopant Upconverted or recovered to the lowest excitation triplet energy level E(2, T, Sh) on the assisting dopant (thermally activated delayed phosphor). Therefore, the generated excitation energy can be used for light emission without waste. In addition, by dividing into two types of molecules capable of improving the function of upconversion and light emission, respectively, it is expected that the residence time of high energy is reduced and the burden on the compound is reduced.

The thermally activated delayed phosphor (TADF compound) used in the TAF element uses an electron-donating substituent called a donor and an electron-accepting substituent called an acceptor to achieve HOMO (Highest Occupied Molecular Orbital) and LUMO (Lowest Unoccupied It is preferable to be a donor-acceptor type thermally activated delayed phosphor (D-A type TADF compound) designed to localize molecular orbitals and cause efficient reverse intersystem crossing.

Here, in the present specification, "electron-donating substituent" (donor) means a substituent and partial structure in which HOMO is localized in a heat-activated delayed phosphor molecule, and "electron-accepting substituent" (acceptor) means a heat It shall mean the substituent and partial structure in which LUMO is localized in active type delayed phosphor molecule.

In general, a thermally activated delayed phosphor using a donor or acceptor has a large spin-orbit coupling (SOC) due to its structure, and at the same time, the exchange interaction between HOMO and LUMO is small and ΔE _S1T1 is small, so, Very fast inverse interphase crossing velocities are obtained. On the other hand, thermally activated delayed phosphors using a donor or acceptor have a large structural relaxation in the excited state (since the stable structure is different between the ground state and the excited state in some molecules, it is changed from the ground state to the excited state by external stimulation). When conversion occurs, the structure is then changed to a stable structure in an excited state), providing a wide luminescence spectrum, so there is a possibility of reducing color purity when used as a luminescent material.

However, by simultaneously using the polycyclic aromatic compound of the present invention, the polycyclic aromatic compound of the present invention functions as an emitting dopant and the TADF compound functions as an assisting dopant, and high color purity can be obtained. The TADF compound may be any compound whose emission spectrum overlaps at least partially with the absorption spectrum of the polycyclic aromatic compound of the present invention. Both the polycyclic aromatic compound and the TADF compound of the present invention may be contained in the same layer, or may be contained in adjacent layers or other adjacent layers.

As the thermally activated delayed phosphor in the TAF element, for example, a compound in which a donor and an acceptor are bonded directly or through a spacer can be used. As the electron-donating group (donor structure) and electron-accepting group (acceptor structure) used in the thermally activated delayed phosphor of the present invention, for example, the structure described in Chemistry of Materials, 2017, 29, 1946-1963 can be used As the donor structure, carbazole, dimethylcarbazole, di-tert-butylcarbazole, dimethoxycarbazole, tetramethylcarbazole, benzofluorocarbazole, benzothienocarbazole, phenyldihydroindolocarbazole, Phenylbicarbazole, bicarbazole, tercarbazole, diphenylcarbazolylamine, tetraphenylcarbazolyldiamine, phenoxazine, dihydrophenazine, phenothiazine, dimethyldihydroacridine, diphenylamine, bis (tert-butylphenyl)amine, N1-(4-(diphenylamino)phenyl)-N4,N4-diphenylbenzene-1,4-diamine, dimethyltetraphenyldihydroacridinediamine, tetramethyl-dihydro- Indenoacridine, diphenyldihydrodibenzoazacillin, etc. are mentioned. As the acceptor structure, sulfonyldibenzene, benzophenone, phenylenebis (phenylmethanone), benzonitrile, isonicotinonitrile, phthalonitrile, isophthalonitrile, paraphthalonitrile, benzenetricarbonitrile, triazole , oxazole, thiadiazole, benzothiazole, benzobis(thiazole), benzooxazole, benzobis(oxazole), quinoline, benzoimidazole, dibenzoquinoxaline, heptaazaphenalene, thioxanthone dioxide , dimethylanthracenone, anthracenedione, 5H-cyclopenta[1,2-b:5,4-b']dipyridine, fluorenedicarbonitrile, triphenyltriazine, pyrazinedicarbonitrile, pyrimidine, phenylpyridine midine, methylpyrimidine, pyridinedicarbonitrile, dibenzoquinoxalinedicarbonitrile, bis(phenylsulfonyl)benzene, dimethylthioxanthenedioxide, thianthrenetetraoxide and tris(dimethylphenyl)borane. In particular, the compound having thermally activated delayed fluorescence in the TAF element has, as a partial structure, carbazole, phenoxazine, acridine, triazine, pyrimidine, pyrazine, thioxanthene, benzonitrile, phthalonitrile, isop It is preferably a compound having at least one selected from talonitrile, diphenylsulfone, triazole, oxadiazole, thiadiazole and benzophenone.

The compound used as the assisting dopant of the light emitting layer in the TAF element is a thermally activated delayed phosphor, and it is preferable that the emission spectrum overlaps at least partially with the absorption peak of the emitting dopant.

[Phosphorescent material]

In the light emitting layer, you may use a phosphorescent material as an assisting dopant. In the present specification, an organic electroluminescent device using a phosphorescent material as an assisting dopant is sometimes referred to as a phosphorescent assist device: a phosphor-sensitized fluorescent device or a PSF device. Phosphorescent materials utilize intramolecular spin-orbit interactions (heavy atom effect) by metal atoms to obtain light emission from excited triplet states. As such a phosphorescent material, a luminescent metal complex can be used, for example. Examples of the luminescent metal complex include compounds represented by the following formula (B-1) and the following formula (B-2).

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 "X-Y" are each independently a bidentate ligand.

In formula (B-2), M is at least one selected from the group consisting of Pt, Re and Cu, and "W-X-Y-Z" is a tetradentate ligand.

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

In Formula (B-2), M is preferably Pt from the viewpoint of efficiency and lifetime.

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

during the ceremony,

--- in combination with the central metal M,

Y is, each independently, BR _e , NR _e , PR _e , O, S, Se, C=O, S=O, SO2, CR _e R _f , SiR _e R _f , or GeR _e R _f ;

Aromatic carbons C-H in the ring may each independently be substituted with N,

R _e and R _f may be optionally condensed or bonded to form a ring,

R _a , R _b , R _c , and R _d may each independently be unsubstituted or substituted by 1 to the maximum number of substitutions;

R _a , R _b , R _c , R _d , R _e , and R _f are each, independently, hydrogen, deuterium, halide, alkyl, cycloalkyl, heteroalkyl, alkoxy, aryloxy, amino, silyl, alkenyl , cycloalkenyl, heteroalkenyl, aryl, heteroaryl, nitrile, isonitrile, sulfanyl, or a combination thereof,

However, arbitrary two adjacent substituents in R _a , R _b , R _c , and R _d may form a ring by condensation or bonding, or may form a multidentate ligand.

Examples of the compound represented by formula (B-1) include Ir(ppy) ₃ , Ir(ppy) ₂ (acac), Ir(mppy) ₃ , Ir(PPy) ₂ (m-bppy), BtpIr( acac), Ir(btp) ₂ (acac), Ir(2-phq) ₃ , Hex-Ir(phq) ₃ , Ir(fbi) ₂ (acac), fac-Tris(2-(3-p-xylyl) phenyl)pyridine iridium(III), Eu(dbm) ₃ (Phen), Ir(piq) ₃ , Ir(piq) ₂ (acac), Ir(Fliq) ₂ (acac), Ir(Flq) ₂ (acac), Ru(dtb-bpy) ₃ 2(PF ₆ ), Ir(2-phq) ₃ , Ir(BT) ₂ (acac), Ir(DMP) ₃ , Ir(Mphq) ₃ IR(phq) ₂ tpy, fac -Ir(ppy) ₂ Pc, Ir(dp)PQ ₂ , Ir(Dpm)(Piq) ₂ , Hex-Ir(piq) ₂ (acac), Hex-Ir(piq) ₃ , Ir(dmpq) ₃ , Ir (dmpq) ₂ (acac), FPQIrpic, and the like.

As a compound represented by Formula (B-1), the following compounds are mentioned, for example other than that.

Further, Japanese Unexamined Patent Publication No. 2006-089398, Japanese Unexamined Patent Publication No. 2006-080419, Japanese Unexamined Patent Publication No. 2005-298483, Japanese Unexamined Patent Publication No. 2005-097263, and Japanese Unexamined Patent Publication No. 2004-111379, US Patent Iridium complexes described in the specification of Patent Publication No. 2019/0051845, etc., or Advanced Materials, 26:7116-7121, NPG Asia Materials 13,53 (2021), Applied Physics Letters, 117, 253301 (2020), Light-Emitting Diode - The platinum complex described in An Outlook On the Empirical Features and Its Recent Technological Advancements, Chapter 5 may be used.

2-1-6. Electron injection layer and electron transport layer in an organic electroluminescent device

The electron injection layer 107 serves to efficiently inject electrons moving from the cathode 108 into the light emitting layer 105 or into the electron transport layer 106 . The electron transport layer 106 serves to efficiently transport electrons injected from the cathode 108 or electrons injected from the cathode 108 through the electron injection layer 107 to the light emitting layer 105 . The electron transport layer 106 and the electron injection layer 107 are formed by laminating or mixing one or more electron transport/injection materials, or a mixture of an electron transport/injection material and a polymeric binder.

The electron injection/transport layer is a layer responsible for injecting electrons from the cathode and transporting the electrons, and preferably has high electron injection efficiency and efficiently transports the injected electrons. For this purpose, it is preferable to use a material that has high electron affinity, high electron mobility, and excellent stability, and is unlikely to generate trap impurities during production and use. However, in the case of considering the transport balance of holes and electrons, in the case where the role of efficiently preventing the flow of holes to the anode without recombination to the cathode side is mainly performed, even if the electron transport capacity is not so high, the luminous efficiency is improved. The effect is equivalent to that of a material having a high electron transport ability. Therefore, the electron injection/transport layer in the present embodiment may also include a function of a layer capable of effectively blocking the movement of holes.

As the material (electron transport material) forming the electron transport layer 106 or the electron injection layer 107, a compound conventionally used as an electron transport compound in photoconductive materials, an electron injection layer and an electron transport layer of an organic EL device. It can be used by selecting it arbitrarily from known compounds in use.

As the material used for the electron transport layer or the electron injection layer, compounds comprising an aromatic ring or heteroaromatic ring composed of at least one atom selected from carbon, hydrogen, oxygen, sulfur, silicon and phosphorus, pyrrole derivatives and condensed ring derivatives thereof; It is preferable to contain at least 1 sort(s) selected from metal complexes which have electron-accepting nitrogen. Specifically, condensed ring aromatic ring derivatives such as naphthalene and anthracene, styryl aromatic ring derivatives represented by 4,4'-bis(diphenylethenyl)biphenyl, perinone derivatives, coumarin derivatives, and naphthalimide derivatives , quinone derivatives such as anthraquinone and diphenoquinone, phosphine oxide derivatives, aryl nitrile derivatives, and indole derivatives. Examples of the metal complex having electron-accepting nitrogen include hydroxyazole complexes such as hydroxyphenyloxazole complexes, azomethine complexes, tropolone metal complexes, flavonol metal complexes, and benzoquinoline metal complexes. This material is used alone, but may be used in combination with other materials.

In addition, as specific examples of other electron transfer compounds, pyridine derivatives, naphthalene derivatives, anthracene derivatives, phenanthroline derivatives, perinone derivatives, coumarin derivatives, naphthalimide derivatives, anthraquinone derivatives, diphenoquinone derivatives, diphenyl quinone Derivatives, perylene derivatives, oxadiazole derivatives (1,3-bis[(4-t-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 auxin derivatives, quinolinol-based metal complexes, quinoxaline derivatives, polymers of quinoxaline derivatives, benzazoles compounds, gallium complexes, pyrazole derivatives, perfluorinated phenylene derivatives, triazine derivatives, pyrazine derivatives, benzoquinoline derivatives (2,2'-bis(benzo[h]quinolin-2-yl)-9,9' -spirofluorene, etc.), imidazopyridine derivatives, borane derivatives, benzoimidazole derivatives (tris(N-phenylbenzoimidazol-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"-terpyridin-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, bisstyryl derivatives, etc. can be heard

In addition, metal complexes having electron-accepting nitrogen can also be used, for example, quinolinol-based metal complexes, hydroxyazole complexes such as hydroxyphenyloxazole complexes, azomethine complexes, tropolone metal complexes, and flavonol metal complexes. and benzoquinoline metal complexes.

The above materials are used alone, but may be used in combination with other materials.

Among the above materials, borane derivatives, pyridine derivatives, fluoranthene derivatives, BO derivatives, anthracene derivatives, benzofluorene derivatives, phosphine oxide derivatives, pyrimidine derivatives, arylnitrile derivatives, triazine derivatives, benzoimidazole derivatives, Phenanthroline derivatives, and quinolinol-based metal complexes are preferred.

<Reducible substance>

The electron transport layer or electron injection layer may further contain a substance capable of reducing a material forming the electron transport layer or electron injection layer. As long as this reducing substance has a certain reducing property, various substances are used, for example, alkali metals, alkaline earth metals, rare earth metals, oxides of alkali metals, halides of alkali metals, oxides of alkaline earth metals, and alkaline earths. At least one selected from the group consisting of 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.

Preferred reducing substances include alkali metals such as Na (work function 2.36 eV), K (2.28 eV copper), Rb (2.16 eV copper) or Cs (1.95 eV copper), Ca (2.9 eV copper), and Sr (2.0 eV copper). ~ 2.5 eV) or Ba (copper 2.52 eV) and the like, and a material having a work function of 2.9 eV or less is particularly preferred. Among these, a more preferable reducing substance is an alkali metal of K, Rb or Cs, even more preferably Rb or Cs, and most preferably Cs. These alkali metals have particularly high reducing ability, and the addition of a relatively small amount to the material forming the electron transport layer or the electron injection layer can improve the light emission luminance and lengthen the lifetime of the organic EL device. In addition, as a reducing substance having a work function of 2.9 eV or less, a combination of two or more alkali metals is also preferable, and in particular, a combination containing Cs, for example, Cs and Na, Cs and K, Cs and Rb, or Cs and a combination of Na and K is preferred. By including Cs, reducing ability can be exhibited efficiently, and addition to the material forming the electron transport layer or electron injection layer can improve the luminescence brightness and lengthen the lifetime of the organic EL device.

2-1-7. Cathode in organic electroluminescent device

The cathode 108 serves to inject electrons into the light emitting layer 105 through the electron injection layer 107 and the electron transport layer 106 .

The material forming the cathode 108 is not particularly limited as long as it is a material capable of efficiently injecting electrons into the organic layer, but the same material as the material forming the anode 102 can be used. Among them, metals or alloys thereof (magnesium-silver alloy, magnesium- aluminum-lithium alloys such as indium alloys and lithium fluoride/aluminum); In order to improve device characteristics by increasing electron injection efficiency, lithium, sodium, potassium, cesium, calcium, magnesium, or alloys containing these low work function metals are effective. However, these low work function metals are generally unstable in air in many cases. In order to improve this point, a method is known in which, for example, an organic layer is doped with a small amount of lithium, cesium or magnesium to use an electrode having high stability. As other dopants, inorganic salts such as lithium fluoride, cesium fluoride, lithium oxide and cesium oxide can also be used. However, it is not limited to these.

Furthermore, metals such as platinum, gold, silver, copper, iron, tin, aluminum, and indium, or alloys using these metals, and inorganic substances such as silica, titania, and silicon nitride, polyvinyl alcohol, vinyl chloride, and hydrocarbons for electrode protection Preferred examples include laminating a polymeric compound or the like. Methods for producing these electrodes are not particularly limited as long as conduction can be achieved, such as resistance heating, electron beam evaporation, sputtering, ion plating and coating.

2-1-8. Manufacturing method of organic electroluminescent device

For each layer constituting the organic EL device, the material constituting each layer is formed into a thin film by a method such as evaporation, resistance heating evaporation, electron beam evaporation, sputtering, molecular lamination method, printing method, spin coating method, casting method, or coating method. By doing so, it can be formed. The film thickness of each layer formed in this way is not particularly limited and can be appropriately set depending on the nature of the material, but is usually in the range of 2 nm to 5000 nm. The film thickness can usually be measured with a crystal oscillation type film thickness measuring device or the like. In the case of thinning using a vapor deposition method, the deposition conditions differ depending on the type of material, the target crystal structure and association structure of the film, and the like. Deposition conditions are generally: boat heating temperature +50 ~ +400 ℃, vacuum degree 10 ^{-6 ~} 10 ^-3 Pa, deposition rate 0.01 ~ 50 nm / sec, substrate temperature -150 ~ +300 ℃, film thickness 2 nm ~ 5㎛ It is desirable to set appropriately within the range.

In the case of applying a direct current voltage to the organic EL element obtained in this way, the anode may be applied with + and the cathode as the polarity, and when a voltage of about 2 to 40 V is applied, the transparent or translucent electrode side (anode or cathode) , and both) can observe luminescence. In addition, this organic EL element emits light even when a pulse current or an alternating current is applied. In addition, the waveform of the alternating current to apply may be arbitrary.

Next, as an example of a method for manufacturing an organic EL device, a method for manufacturing an organic EL device composed of an anode/a hole injection layer/a hole transport layer/a light emitting layer composed of a host material and a dopant material/an electron transport layer/an electron injection layer/cathode Explain.

<Deposition method>

After fabricating an anode by forming a thin film of anode material on a suitable substrate by vapor deposition or the like, thin films of a hole injection layer and a hole transport layer are formed on the anode. A host material and a dopant material are co-evaporated on this to form a thin film to form a light emitting layer, an electron transport layer and an electron injection layer are formed on the light emitting layer, and a thin film made of a material for the cathode is formed by a vapor deposition method or the like to form a cathode, thereby forming a desired organic material. An EL element is obtained. In addition, in fabricating the organic EL device described above, it is also possible to reverse the fabrication order and fabricate the cathode, electron injection layer, electron transport layer, light emitting layer, hole transport layer, hole injection layer and anode in this order.

<Wet film forming method>

The wet film forming method is performed by preparing a low-molecular compound capable of forming each organic layer of an organic EL element as a liquid composition for forming an organic layer, and using the same. When there is no suitable organic solvent for dissolving the low molecular weight compound, a reactive compound obtained by substituting a reactive substituent in the low molecular weight compound and a composition for forming an organic layer from a high molecular compound polymerized together with other monomers having a soluble function or a main chain polymer, etc. you can prepare

In the wet film forming method, generally, a coating film is formed by passing through an application step of applying a composition for forming an organic layer to a substrate and a drying step of removing a solvent from the applied composition for forming an organic layer. When the polymer compound has a cross-linkable substituent (also referred to as a cross-linkable polymer compound), it is further cross-linked in this drying step to form a polymer cross-linked body. Depending on the difference in the coating process, the method using a spin coater is spin coating, the method using a slit coater is a slit coating method, and the method using a plate is gravure, offset, reverse offset, flexo printing, and inkjet printer. The method of using is called the inkjet method, and the method of spraying in the form of mist is called the spray method. The drying process includes methods such as air drying, heating, and drying under reduced pressure. The drying step may be performed only once, or may be performed a plurality of times using different methods and conditions. In addition, you may use other methods together, such as baking under reduced pressure, for example.

The wet film forming method is a film forming method using a solution, and includes, for example, some printing methods (inkjet method), a spin coat method, a cast method, a coating method, and the like. Unlike the vacuum deposition method, the wet film formation method does not require the use of an expensive vacuum deposition apparatus and can form a film under atmospheric pressure. In addition, the wet film forming method enables large-area and continuous production, leading to reduction in manufacturing cost.

On the other hand, when compared with the vacuum evaporation method, the wet film formation method may be difficult to laminate. When a multilayer film is produced using a wet film forming method, it is necessary to prevent dissolution of the lower layer by the composition of the upper layer, so a composition with controlled solubility, cross-linking of the lower layer and orthogonal solvent (solvent that does not dissolve in each other), etc. this is spoken However, even if these techniques are used, there are cases where it is difficult to use the wet film formation method for coating all films.

Therefore, generally, a method of fabricating an organic EL device by using a wet film forming method for only a few layers and vacuum evaporation is employed for the rest.

For example, a procedure for fabricating an organic EL device by partially applying a wet film forming method is shown below.

(Procedure 1) Film formation by vacuum evaporation of the anode

(Procedure 2) Formation of a composition for forming a hole injection layer containing a material for a hole injection layer by a wet film forming method

(Procedure 3) Formation of a composition for forming a hole transport layer containing a material for a hole transport layer by a wet film forming method

(Procedure 4) Formation of a composition for forming a light emitting layer containing a host material and a dopant material by a wet film forming method

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

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

(Procedure 7) Film formation by vacuum evaporation of cathode

By passing through this procedure, an organic EL device composed of an anode/a hole injection layer/a hole transport layer/a light emitting layer composed of a host material and a dopant material/an electron transport layer/an electron injection layer/cathode is obtained.

Of course, the electron transport layer and the electron injection layer may also be formed by a wet film forming method using a composition for layer formation containing a material for an electron transport layer and a material for an electron injection layer, respectively. At this time, it is preferable to use a means for preventing dissolution of the lower light emitting layer or a means for forming a film from the cathode side contrary to the above procedure.

<Other Tabernacling Methods>

A laser heating drawing method (LITI) can be used for film formation of the composition for forming an organic layer. LITI is a method of heating and depositing a compound attached to a substrate with a laser, and a composition for forming an organic layer can be used for a material applied to the substrate.

<Random process>

Appropriate treatment steps, washing steps, and drying steps may be suitably incorporated before and after each step of film formation. Examples of the treatment step include exposure treatment, plasma surface treatment, ultrasonic treatment, ozone treatment, washing treatment using an appropriate solvent, heat treatment, and the like. In addition, a series of steps for producing a bank are also mentioned.

A photolithography technique can be used for fabrication of the bank. As a bank material for which photolithography can be used, a positive type resist material and a negative type resist material can be used. In addition, patternable printing methods such as inkjet printing, gravure offset printing, reverse offset printing, and screen printing can also be used. In this case, a permanent resist material may be used.

Materials used for the bank include polysaccharides and their derivatives, homopolymers and copolymers of hydroxyl-containing ethylenic monomers, biomolecular compounds, polyacryloyl compounds, polyesters, polystyrenes, polyimides, polyamideimides, and polyethers. Mead, polysulfide, polysulfone, polyphenylene, polyphenylether, polyurethane, epoxy (meth)acrylate, melamine (meth)acrylate, polyolefin, cyclic polyolefin, acrylonitrile-butadiene-styrene copolymer (ABS ), silicone resin, polyvinyl chloride, chlorinated polyethylene, chlorinated polypropylene, polyacetate, polynorbornene, synthetic rubber, fluorinated polymers such as polyfluorovinylidene, polytetrafluoroethylene, polyhexafluoropropylene, fluoropolymers Although a copolymer polymer of olefin-hydrocarbon olefin and a fluorocarbon polymer are mentioned, it is not limited only to them.

<Composition for Forming Organic Layer Used in Wet Film Formation>

A composition for forming an organic layer is obtained by dissolving a low-molecular compound capable of forming each organic layer of an organic EL device or a high-molecular compound obtained by polymerizing the low-molecular compound in an organic solvent. For example, a composition for forming a light emitting layer includes at least one polycyclic aromatic compound (or a polymer compound thereof) as a dopant material as a first component, at least one host material as a second component, and at least one as a third component. Contains a species of organic solvent. The first component functions as a dopant component of the light emitting layer obtained from the composition, and the second component functions as a host component of the light emitting layer. The third component functions as a solvent for dissolving the first and second components in the composition, and imparts a smooth and uniform surface shape upon application by the controlled evaporation rate of the third component itself.

<Organic Solvent>

The composition for forming an organic layer contains at least one organic solvent. By controlling the evaporation rate of the organic solvent at the time of film formation, film formability, the presence or absence of defects in the coating film, surface roughness, and smoothness can be controlled and improved. Further, in the case of film formation using the inkjet method, the meniscus stability in the pinhole of the inkjet head can be controlled to control and improve ejection properties. In addition, by controlling the drying speed of the film and the orientation of the derivative molecules, it is possible to improve the electrical characteristics, light-emitting characteristics, efficiency, and lifetime of an organic EL device having an organic layer obtained from the composition for forming an organic layer.

(1) physical properties of organic solvents

The boiling point of the at least one organic solvent is 130°C to 300°C, more preferably 140°C to 270°C, still more preferably 150°C to 250°C. When the boiling point is higher than 130°C, it is preferable from the viewpoint of inkjet ejection properties. In addition, when the boiling point is lower than 300°C, it is preferable from the viewpoint of defects, surface roughness, residual solvent and smoothness of the coating film. The organic solvent is more preferably composed of two or more organic solvents from the viewpoints of good inkjet ejection properties, film formability, smoothness, and low residual solvent. On the other hand, depending on the case, a composition made into a solid state by removing the solvent from the composition for forming an organic layer may be used in consideration of transportability and the like.

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 of the good solvent (GS) (BP _GS ) is the boiling point of the poor solvent (PS) (BP _PS ) A lower, configuration is particularly preferred.

By adding a poor solvent with a high boiling point, the good solvent with a low boiling point first volatilizes at the time of film formation, and the concentration of the content in the composition and the concentration of the poor solvent increase, thereby promoting rapid film formation. Thereby, a coating film with few defects, small surface roughness, and high smoothness is obtained.

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 still more preferably 50°C or higher.

After film formation, the organic solvent is removed from the coating film by a drying process such as vacuum, reduced pressure, or heating. In the case of heating, from the viewpoint of improving coating film formability, it is preferable to perform heating at a glass transition temperature (Tg) of at least one of the solutes +30°C or lower. Further, from the viewpoint of reducing the residual solvent, it is preferable to heat the glass transition point (Tg) of at least one of the solutes to -30°C or higher. Since the film is thin even when the heating temperature is lower than the boiling point of the organic solvent, the organic solvent is sufficiently removed. Moreover, drying may be performed a plurality of times at different temperatures, or a plurality of drying methods may be used in combination.

(2) Specific examples of organic solvents

Examples of organic solvents used in the composition for forming an organic layer include alkylbenzene solvents, phenyl ether solvents, alkyl ether solvents, cyclic ketone solvents, aliphatic ketone solvents, monocyclic ketone solvents, solvents having a diester skeleton, and fluorine-based solvents and the like, and specific examples include pentanol, hexanol, heptanol, octanol, nonanol, decanol, undecanol, dodecanol, tetradecanol, hexan-2-ol, heptan-2- Ol, octan-2-ol, decan-2-ol, dodecan-2-ol, cyclohexanol, α-terpineol, β-terpineol, γ-terpineol, δ-terpineol, ter Pineol (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 isopropylmethyl 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-lutein Dean, 2-fluoro-m-xylene, 3-fluoro-o-xylene, 2-chlorobenzotrifluoride, cumene, toluene, 2-chloro-6-fluorotoluene, 2-fluoroanisole, anisole , 2,3-dimethylpyrazine, bromobenzene, 4-fluoroanisole, 3-fluoroanisole, 3-trifluoromethylanisole, mesitylene, 1,2,4-trimethylbenzene, t-butyl Benzene, 2-methylanisole, phenetole, benzodioxole, 4-methylanisole, s-butylbenzene, 3-methylanisole, 4-fluoro-3-methylanisole, cymene, 1,2,3 -Trimethylbenzene, 1,2-dichlorobenzene, 2-fluorobenzonitrile, 4-fluoroveratrol, 2,6-dimethylanisole, n-butylbenzene, 3-fluorobenzonitrile, decalin (decahydronaphthalene ), neopentylbenzene, 2,5-dimethylanisole, 2,4-dimethylanisole, benzonitrile, 3,5-dimethylanisole, diphenyl ether, 1-fluoro-3,5-dimethoxybenzene, Methyl benzoate, isopentylbenzene, 3,4-dimethylanisole, o-tolnitrile, n-amylbenzene, veratrol, 1,2,3,4-tetrahydronaphthalene, ethyl benzoate, n-hexylbenzene, propyl benzoate , cyclohexylbenzene, 1-methylnaphthalene, butyl benzoate, 2-methylbiphenyl, 3-phenoxytoluene, 2,2'-bitril, dodecylbenzene, dipentylbenzene, tetramethylbenzene, trimethoxybenzene, Trimethoxytoluene, 2,3-dihydrobenzofuran, 1-methyl-4-(propoxymethyl)benzene, 1-methyl-4-(butyloxymethyl)benzene, 1-methyl-4-(pentyloxymethyl ) Benzene, 1-methyl-4- (hexyloxymethyl) benzene, 1-methyl-4- (heptyloxymethyl) benzene, benzyl butyl ether, benzyl pentyl ether, benzyl hexyl ether, benzyl heptyl ether, benzyl octyl ether, etc. Examples include, but are not limited to. In addition, a solvent may be used singly or may be mixed.

<Optional ingredients>

The composition for forming an organic layer may contain arbitrary components within a range that does not impair its properties. As an arbitrary component, a binder, surfactant, etc. are mentioned.

(1) Binder

The composition for forming an organic layer may contain a binder. The binder bonds the obtained film to the substrate while forming a film at the time of film formation. In addition, it serves to dissolve, disperse, and bind other components in the composition for forming the organic layer.

As the binder used in the composition for forming the organic layer, for example, acrylic resin, polyethylene terephthalate, ethylene-vinyl acetate copolymer, ethylene-vinyl alcohol copolymer, acrylonitrile-ethylene-styrene copolymer (AES) resin, Ionomer, chlorinated polyether, diarylphthalate resin, unsaturated polyester resin, polyethylene, polypropylene, polyvinyl chloride, polyvinylidene chloride, polystyrene, polyvinyl acetate, Teflon, acrylonitrile-butadiene-styrene copolymer (ABS) resins, acrylonitrile-styrene copolymer (AS) resins, phenolic resins, epoxy resins, melamine resins, urea resins, alkyd resins, polyurethanes, and copolymers of the above resins and polymers, but are not limited thereto. don't

The binder used in the composition for forming an organic layer may be used alone or in combination of multiple types.

(2) Surfactant

The composition for forming an organic layer may contain, for example, a surfactant for controlling the uniformity of the film surface and the solvent affinity and liquid repellency of the film surface of the composition for forming an organic layer. Surfactants are classified into ionic and nonionic based on the structure of the hydrophilic group, and further classified into alkyl, silicon and fluorine based based on the structure of the hydrophobic group. In addition, from the structure of the molecule, it is classified into a monomolecular system having a relatively small molecular weight and a simple structure, and a macromolecular system having a large molecular weight and side chains or branches. Also, from the composition, it is classified into a single system and a mixed system in which two or more types of surfactants and a substrate are mixed. As the surfactant that can be used in the composition for forming the organic layer, all kinds of surfactants can be used.

As surfactant, for example, Polyflow No.45, Polyflow KL-245, Polyflow No.75, Polyflow No.90, Polyflow No.95 (trade name, Kyoeisha Chemical Industry Co., Ltd. product) , Disperbyk 161, Disperbake 162, Disperbake 163, Disperbake 164, Disperbake 166, Disperbake 170, Disperbake 180, Disperbake 181, Disperbake 182, BYK 300, BYK 306, BYK 310, BYK 320, BYK 330, BYK 342, BYK 344, BYK 346 (trade name, manufactured by Big Chemie Japan Co., Ltd.), KP-341, KP-358, KP-368, KF-96 -50CS, KF-50-100CS (trade name, manufactured by Shin-Etsu Chemical Co., Ltd.), Supreon SC-101, Supreon KH-40 (trade name, manufactured by Seimi Chemical Co., Ltd.), Phtagent 222F, Phtagent 251 , FTX-218 (trade name, manufactured by Neos Co., Ltd.), EFTOP EF-351, EFTOP EF-352, EFTOP EF-601, EFTOP EF-801, EFTOP EF-802 (trade name, manufactured by Mitsubishi Materials Co., Ltd.), Megapack F-470, Megapack F-471, Megapack F-475, Megapack R-08, Megapack F-477, Megapack F-479, Megapack F-553, Megapack F-554 DIC Co., Ltd.), fluoroalkylbenzenesulfonate, fluoroalkylcarboxylate, fluoroalkylpolyoxyethylene ether, fluoroalkylammonium iodide, fluoroalkylbetaine, fluoroalkylsulfonate, di Glycerin tetrakis (fluoroalkylpolyoxyethylene ether), fluoroalkyltrimethylammonium salt, fluoroalkylaminosulfonic acid salt, polyoxyethylene nonylphenyl ether, polyoxyethylene octylphenyl ether, polyoxyethylene alkyl ether, polyoxyethylene lauryl Polyoxyethylene oleate, polyoxyethylene stearate, polyoxyethylene laurylamine, sorbitan laurate, sorbitan palmitate, sorbitan stearate, sorbitan oleate, sorbitan fatty acid ester, polyoxyethylene sorbitol butane laurate, polyoxyethylene sorbitan palmitate, polyoxyethylene sorbitan stearate, polyoxyethylene sorbitan oleate, polyoxyethylene naphthyl ether, alkylbenzenesulfonates and alkyldiphenyletherdisulfonates. there is.

In addition, surfactant may be used by 1 type, and may use 2 or more types together.

<Composition and physical properties of composition for forming organic layer>

The content of each component in the composition for forming an organic layer determines the good solubility, storage stability and film formability of each component in the composition for forming an organic layer, the quality of a coating film obtained from the composition for forming an organic layer, and the inkjet method. It is determined in consideration of the good ejection properties in the case of use, and the good electrical characteristics, light emitting characteristics, efficiency, and lifetime of an organic EL device having an organic layer produced using the composition. For example, in the case of the composition for forming a light emitting layer, the first component is 0.0001% to 2.0% by mass based on the total mass of the composition for forming a light emitting layer, and the second component is 0.0999% by mass based on the total mass of the composition for forming a light emitting layer. % to 8.0% by mass, and the third component is preferably 90.0% to 99.9% by mass with respect to the total mass of the composition for forming a light emitting layer.

More preferably, the first component is 0.005% to 1.0% by mass based on the total mass of the composition for forming a light emitting layer, and the second component is 0.095% to 4.0% by mass based on the total mass of the composition for forming a light emitting layer. The three components are 95.0% by mass to 99.9% by mass with respect to the total mass of the composition for forming a light emitting layer. Even more preferably, the first component is 0.05% by mass to 0.5% by mass, the second component is 0.25% to 2.5% by mass based on the total mass of the composition for forming a light emitting layer, The 3rd component is 97.0 mass % - 99.7 mass % with respect to the total mass of the composition for light emitting layer formation.

The composition for forming an organic layer can be prepared by appropriately selecting and performing stirring, mixing, heating, cooling, dissolution, dispersion, etc. of the above-mentioned components by a known method. After preparation, filtration, degassing (also referred to as degassing), ion exchange treatment, and inert gas replacement/encapsulation treatment may be appropriately selected and performed.

As for the viscosity of the composition for forming an organic layer, those with high viscosity give good film formability and good ejection properties in the case of using the inkjet method. On the other hand, it is easy to make a thin film of low viscosity. From this, it is preferable that the viscosity in 25 degreeC of the viscosity of this composition for organic layer formation is 0.3-3 mPa*s, and it is more preferable that it is 1-3 mPa*s. In the present invention, the viscosity is a value measured using a cone-plate rotational viscometer (conical plate type).

As for the surface tension of the composition for forming an organic layer, the lower the surface tension, the better film formability and defect-free coating can be obtained. On the other hand, a higher one can obtain good inkjet ejection properties. From this, it is preferable that the surface tension in 25 degreeC of this composition for organic layer formation is 20-40 mN/m, and it is more preferable that it is 20-30 mN/m. In the present invention, the surface tension is a value measured using the hanging drop method.

<Crosslinkable High Polymer Compound: Compound Represented by Formula (XLP-1)>

Next, the case where the above-mentioned high molecular compound has a crosslinkable substituent is demonstrated. Such a crosslinkable high molecular compound is a compound represented by the following formula (XLP-1), for example.

In formula (XLP-1),

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

More specifically,

MUx is each independently arylene, heteroarylene, diarylene arylamino, diarylene arylboryl, oxaborine-diyl, azaborin-diyl,

ECx is, each independently, hydrogen, aryl, heteroaryl, diarylamino, diheteroarylamino, arylheteroarylamino or aryloxy;

At least one hydrogen in MUx and ECx may be further substituted with aryl, heteroaryl, diarylamino, alkyl and cycloalkyl,

k is an integer from 2 to 50000;

It is preferable that k is an integer of 20-50000, and it is more preferable that it is an integer of 100-50000.

At least one hydrogen in MUx and ECx in formula (XLP-1) may be substituted with C1-C24 alkyl, C3-C24 cycloalkyl, halogen or deuterium, and any -CH ₂ - may be further substituted with -O- or -Si(CH ₃ ) ₂ -, and any - except for -CH ₂ - directly linked to ECx in formula (XLP-1) in the above alkyl CH ₂ - may be substituted with C6-C24 arylene, and arbitrary hydrogen in the said alkyl may be substituted with fluorine.

As MUx, the divalent group represented by removing two arbitrary hydrogen atoms with any one of the following compounds is mentioned, for example.

More specifically, a divalent group represented by any one of the following structures is exemplified. In these, MUx is combined with another MUx or ECx in *.

Moreover, as ECx, the monovalent group represented by any one of the following structures is mentioned, for example. In these, EC binds to MUx for *.

In the compound represented by the formula (XLP-1), from the viewpoint of solubility and coating film properties, 10 to 100% of the MU of the total number (k) of MU in the molecule preferably has an alkyl having 1 to 24 carbon atoms, and the MU in the molecule It is more preferable that 30 to 100% of the total number (k) of the MU has an alkyl having 1 to 18 carbon atoms (branched chain alkyl having 3 to 18 carbon atoms), and 50 to 100% of the total number (k) of the MU in the molecule is It is more preferable to have an alkyl of 1 to 12 carbon atoms (branched chain alkyl of 3 to 12 carbon atoms). On the other hand, from the viewpoint of in-plane orientation and charge transport, it is preferable that 10 to 100% of the MU of the total number of MUs (k) in the molecule has an alkyl having 7 to 24 carbon atoms, and 30 to 100% of the total number of MUs (k) in the molecule It is more preferable that MU of has C7-C24 alkyl (C7-C24 branched chain alkyl).

0.5-50 mass % is preferable, and, as for content of the monovalent or divalent aromatic compound which has a crosslinkable substituent, 1-20 mass % is more preferable.

The crosslinkable substituent (XLS) is not particularly limited as long as it is a group capable of further crosslinking the polymer compound described above, but a substituent having the following structure is preferable. * in each structural formula represents a bonding position.

L is, each independently, a single bond, -O-, -S-, >C=O, -O-C(=O)-, C1-C12 alkylene, C1-C12 oxyalkylene, and C1 It is a polyoxyalkylene of ~12. Among the above 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 preferable. and a group represented by formula (XLS-1), formula (XLS-3) or formula (XLS-17) is more preferred.

As a divalent aromatic compound which has a crosslinkable substituent, the compound which has the following partial structure is mentioned, for example. * in the following structural formula represents a bonding position.

<Method for producing high molecular compound and crosslinkable high molecular compound>

The method for producing the high molecular compound and the crosslinkable high molecular compound will be described by taking the compound represented by the above formula (XLP-1) as an example. These compounds can be synthesized by appropriately combining known production methods.

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

Also, the reaction may be performed in a two-phase system. In the case of reacting in a two-phase system, a phase transfer catalyst such as a quaternary ammonium salt may be added as needed.

When producing the compound of Formula (XLP-1), it may be produced in one step or may be produced through multiple steps. In addition, it may be carried out by a batch polymerization method in which the reaction is started after all the raw materials are put into the reaction vessel, or may be carried out by a drop polymerization method in which the raw materials are added dropwise to the reaction vessel, or the product precipitates as the reaction proceeds. You may carry out by polymerization method, and it is compoundable by combining these suitably. For example, when synthesizing the compound represented by formula (XLP-1) in one step, a monomer having a polymerizable group bonded to the monomer unit (MU) and a monomer having a polymerizable group bonded to the end cap unit (EC) are placed in a reaction vessel. The target product is obtained by reacting in the added state. In addition, when synthesizing the compound represented by Formula (XLP-1) in multiple steps, after polymerizing the monomer having a polymerizable group bonded to the monomer unit (MU) to a desired molecular weight, the monomer having a polymerizable group bonded to the end cap unit (EC) The target product is obtained by adding and reacting. When a monomer having a polymerizable group bonded to different types of monomer units (MU) is added and reacted in multiple stages, a polymer having a concentration gradient with respect to the structure of the monomer units can be produced. In addition, after preparing the precursor polymer, the target polymer can be obtained by post-reaction.

In addition, the primary structure of the polymer can be controlled by selecting the polymerizable group of the monomer unit (MU). 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 scheme 2 and 3), etc. are synthesized. It is possible, and it can be used in appropriate combination according to the target object. Furthermore, if a monomer having three or more polymerizable groups is used, a hyperbranched polymer or a dendrimer can be synthesized.

Monomers that can be used in the present invention are Japanese Patent Application Publication No. 2010-189630, International Publication No. 2012/086671, International Publication No. 2013/191088, International Publication No. 2002/045184, International Publication No. 2011/049241, International Publication No. 2013/146806, International Publication No. 2005/049546, International Publication No. 2015/145871, Japanese Patent Application Publication No. 2010-215886, Japanese Patent Application Publication No. 2008-106241, International Publication No. 2016/031639, Japan It is compoundable according to the method described in Unexamined-Japanese-Patent No. 2011-174062.

In addition, regarding the specific polymer synthesis procedure, 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 may be referred to.

2-1-9. Application Examples of Organic Electroluminescent Devices

INDUSTRIAL APPLICABILITY The present invention can also be applied to a display device including an organic EL element or a lighting device including an organic EL element.

A display device or lighting device including an organic EL element can be manufactured by a known method such as connecting the organic EL element according to the present embodiment to a known drive device, and known DC drive, pulse drive, AC drive, etc. It can be driven by appropriately using the driving method of .

Examples of the display device include a panel display such as a color flat panel display, a flexible display such as a flexible color organic electroluminescent (EL) display, and the like (eg, Japanese Patent Laid-Open No. 10-335066, Japanese Unexamined Patent Publication No. 2003-321546, Japanese Unexamined Patent Publication No. 2004-281086, etc.). In addition, as a display method of a display, a matrix method, a segment method, etc. are mentioned, for example. Also, the matrix display and the segment display may coexist in the same panel.

In the matrix, pixels for display are two-dimensionally arranged in a lattice or mosaic form, and characters or images are displayed by a set of pixels. The shape or size of the pixel is determined according to the purpose. For example, for displaying images and characters on computers, monitors, and televisions, square pixels with sides of 300 μm or less are usually used, and in the case of large displays such as display panels, pixels on the order of mm are used. will do In the case of monochrome display, pixels of the same color may be arranged, but in the case of color display, red, green, and blue pixels are arranged and displayed. In this case, there are typically a delta type and a stripe type. Incidentally, as a driving method for this matrix, either a line-sequential driving method or an active matrix may be used. Line-sequential driving has the advantage of having a simple structure, but when operating characteristics are taken into consideration, the active matrix method may be superior, so it is necessary to use this also according to the purpose.

In the segment method (type), a pattern is formed to display predetermined information, and a predetermined area is illuminated. For example, the time or temperature display in a digital watch or thermometer, the operation state display of an audio device or electric cooker, and the panel display of a car etc. are mentioned.

Examples of the lighting device include lighting devices such as indoor lighting, backlights of liquid crystal display devices, and the like (for example, Japanese Patent Laid-Open No. 2003-257621, Japanese Patent Laid-Open No. 2003-277741, Japanese Patent). Publication No. 2004-119211, etc.). Backlights are mainly used for the purpose of improving the visibility of display devices that do not emit light, and are used for liquid crystal display devices, clocks, audio devices, automobile panels, display panels, and signs. In particular, considering that it is difficult to reduce the thickness of a liquid crystal display device, especially a backlight for a computer where thinning is a problem, because the conventional method consists of a fluorescent lamp or a light guide plate, the backlight using the light emitting element according to the present embodiment is thin. and is characterized by being lightweight.

2-2. other organic devices

The polycyclic aromatic compound according to the present invention can be used for fabrication of an organic field effect transistor or an organic thin film solar cell in addition to the organic electroluminescent device described above.

An organic field effect transistor is a transistor that controls a current by an electric field generated by inputting a voltage, and has a gate electrode in addition to a source electrode and a drain electrode. When a voltage is applied to the gate electrode, an electric field is generated, and the flow of electrons (or holes) flowing between the source electrode and the drain electrode is arbitrarily stopped to control the current. Field effect transistors are easier to miniaturize than simple transistors (bipolar transistors), and are often used as elements constituting integrated circuits and the like.

The structure of the organic field effect transistor is usually provided with a source electrode and a drain electrode in contact with the organic semiconductor active layer formed using the polycyclic aromatic compound according to the present invention, and furthermore, an insulating layer (dielectric layer) in contact with the organic semiconductor active layer is interposed between them. , and a gate electrode is provided. As the element structure, the following structures are mentioned, for example.

(1) Substrate/gate electrode/insulator layer/source electrode/drain electrode/organic semiconductor active layer

(2) Substrate/gate electrode/insulator layer/organic semiconductor active layer/source electrode/drain electrode

(3) Substrate/organic semiconductor active layer/source electrode/drain electrode/insulator layer/gate electrode

(4) Substrate/source electrode/drain electrode/organic semiconductor active layer/insulator layer/gate electrode

The organic field effect transistor structured as described above can be applied as a pixel drive switching element of an active matrix drive type liquid crystal monitor or an organic light emitting element display.

An organic thin-film solar cell has a structure in which an anode such as ITO, a hole transport layer, a photoelectric conversion layer, an electron transport layer, and a cathode are laminated on a transparent substrate such as glass. The photoelectric conversion layer has a p-type semiconductor layer on the anode side and an n-type semiconductor layer on the cathode side. The polycyclic aromatic compound according to the present invention can be used as a material for a hole transport layer, a p-type semiconductor layer, an n-type semiconductor layer, and an electron transport layer depending on its physical properties. The polycyclic aromatic compound according to the present invention can function as a hole transport material or an electron transport material in an organic thin film solar cell. The organic thin-film solar cell may appropriately include a hole blocking layer, an electron blocking layer, an electron injection layer, a hole injection layer, a smoothing layer, and the like other than the above. For organic thin-film solar cells, well-known materials used for organic thin-film solar cells can be appropriately selected and used in combination.

3. Wavelength Conversion Materials

The polycyclic aromatic compound of the present invention can be used as a wavelength conversion material. Currently, application of multi-colorization technology by a color conversion method to liquid crystal monitors, organic EL displays, lighting, and the like is being intensively studied. Color conversion is wavelength conversion of light emission from a light emitting body into longer wavelength light, and indicates, for example, conversion of ultraviolet light or blue light into green light or red light emission. By forming a film of this wavelength conversion material having a color conversion function and combining it with, for example, a blue light source, it becomes possible to extract the three primary colors of blue, green, and red, that is, to extract white light from the blue light source. A full-color display can be manufactured by using a white light source obtained by combining such a blue light source and a wavelength conversion film having a color conversion function as a light source unit, and combining a liquid crystal driving part and a color filter. In addition, if there is no liquid crystal driving part, it can be used as a white light source as it is, and can be applied as a white light source such as LED lighting, for example. In addition, by using a blue organic EL element as a light source in combination with a wavelength conversion film that converts blue light into green light and red light, it is possible to manufacture a full-color organic EL display without using a metal mask. In addition, by using a blue micro LED as a light source in combination with a wavelength conversion film that converts blue light into green light and red light, it is possible to manufacture a low-cost full-color micro LED display.

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

The composition for converting wavelengths may contain, in addition to the polycyclic aromatic compound of the present invention, a binder resin, other additives, and a solvent. As binder resin, what was described in Paragraph 0173 - 0176 of International Publication No. 2016/190283 can be used, for example. As other additives, the compounds described in Paragraphs 0177 to 0181 of International Publication No. 2016/190283 can be used. As the solvent, the description of the solvent contained in the above composition for forming a light emitting layer can be referred to.

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

[Example]

Hereinafter, the present invention will be described more specifically by means of examples, but the present invention is not limited thereto.

Synthesis Example (1):

Synthesis of compound (1-1)

To a flask containing compound (S-1) (0.91 g) and tert-butylbenzene (7.0 ml), a 1.6 M tert-butyllithium pentane solution (1.6 ml) was added at -30°C under a nitrogen atmosphere. After completion of the dropwise addition, the temperature was raised to 60°C and stirred for 2 hours, and then components having a lower boiling point than tert-butylbenzene were distilled off under reduced pressure. After cooling to -30°C, boron tribromide (0.63 g) was added, the temperature was raised to room temperature, and the mixture was stirred for 0.5 hour. Thereafter, the mixture was cooled to 0°C again, N,N-diisopropylethylamine (0.43 ml) was added, and the mixture was stirred at room temperature until the exotherm subsided, then the temperature was raised to 120°C, and the mixture was heated and stirred for 3 hours. The reaction solution was cooled to room temperature, and an aqueous solution of sodium acetate cooled in an ice bath was added and then heptane was added to separate the mixture. Then, after purification with a silica gel short-pass column (additive: toluene), the solvent was distilled off under reduced pressure, the obtained solid was dissolved in toluene, and heptane was added to precipitate it again to obtain compound (1-1) (0.63 g). got it

MALDI-TOF-MS: [M] ⁺ =885.52

Synthesis Example (2):

Synthesis of compound (1-2)

It was synthesized by a method according to Synthesis Example (1).

MALDI-TOF-MS(M ⁺ )=941.49

Synthesis Example (3):

Synthesis of compound (1-3)

Compound (S-3) (123 mg, 0.10 mmol), 2,6-di-tertiarybutylpyridine (65.0 μL, 0.30 mmol), 1,2, After adding 4-trichlorobenzene (1.0 mL), the mixture was heated and stirred at 60°C for 4 hours. After cooling the reaction solution to room temperature, phosphate buffer (pH = 7) was added to the reaction solution, followed by extraction with dichloromethane three times, and distillation of the solvent under reduced pressure to obtain a crude product. The obtained crude product was subjected to silica gel chromatography (hexane: dichloromethane = 3: 2), and then the solvent was distilled off under reduced pressure to obtain the compound represented by formula (1-3) (74.6 mg, yield 60%) as a yellow solid. got it

¹ H-NMR (500 MHz, CDCl ₃ ): δ = 5.03 (dd, 4H), 5.57 (s, 1H), 6.67 (d, 2H), 6.83 (dd, 4H), 7.09-7.23 (m, 26H), 7.25-7.27(m, 2H), 7.31-7.38(m, 8H), 7.43-7.46(m, 8H), 9.10(dd, 2H), 10.32(s, 1H)

¹¹ B-NMR (128 MHz, CDCl ₃ ): δ = 39.7

MALDI-TOF-MS(M ⁺ )=1244.49

Synthesis Example (4):

Synthesis of compound (1-4)

It was synthesized by a method according to Synthesis Example (3).

MALDI-TOF-MS(M ⁺ )=1328.49

Synthesis Example (5):

Synthesis of compound (1-5)

It was synthesized by a method according to Synthesis Example (3).

MALDI-TOF-MS(M ⁺ )=1185.42

Synthesis Example (6):

Synthesis of compound (1-6)

Compound (S-6) (403 mg, 0.30 mmol), 2,6-di-tertiarybutylpyridine (195 μL, 0.90 mmol), 1,2,4 with respect to boron triiodide (940 mg, 2.4 mmol) under a nitrogen atmosphere. - After adding trichlorobenzene (3.0 mL), the mixture was heated and stirred at 60°C for 4 hours. After cooling the reaction solution to room temperature, phosphate buffer (pH = 7) was added to the reaction solution, followed by extraction with dichloromethane three times, and distillation of the solvent under reduced pressure to obtain a crude product. The obtained crude product was subjected to silica gel chromatography (hexane: dichloromethane = 3: 2), and then the solvent was distilled off under reduced pressure to obtain the compound represented by formula (1-6) as a yellow solid (163 mg, yield 40%). .

¹ H-NMR (500 MHz, CDCl ₃ ): δ = 1.34 (s, 18H), 4.89 (dd, 2H), 5.02 (dd, 2H), 6.11 (s, 1H), 6.66 (d, 2H), 6.78 ( d, 2H), 7.10-7.21(m, 23H), 7.26(m, 3H), 7.30-7.36(m, 8H), 7.41-7.46(m, 8H), 9.07(d, 2H), 10.30(s, 1H)

¹¹ B-NMR (128 MHz, CDCl ³ ): δ = 40.1

MALDI-TOF-MS(M ⁺ )=1356.62

Synthesis Example (7):

Synthesis of compound (1-7)

Compound (S-7) (146mg, 0.15mmol) in a nitrogen atmosphere, 9H-tribenzo[b,d,f]azepine (73.0mg, 0.30mmol), palladium complex catalyst NECO-296 (N E Camcat Co., Ltd.) (18.2 mg, 30 μmol), tert-butoxy sodium (86.5 mg, 0.90 mmol), and mesitylene (3.0 mL) were added, followed by heating and stirring at 140° C. for 4 hours. After cooling the reaction solution to room temperature, it was filtered using a silica gel short pass column, and the solvent was distilled off under reduced pressure to obtain a crude product. The obtained crude product was subjected to silica gel chromatography (hexane: dichloromethane = 3: 2), and then the solvent was distilled off under reduced pressure to obtain the compound represented by formula (1-7) as a yellow solid (180 mg, yield 87%). .

¹ H-NMR (500 MHz, CDCl ₃ ): δ = 2.14 (s, 12H), 2.30 (s, 12H), 2.31 (s, 6H), 4.91 (dd, 2H), 5.04 (dd, 2H), 5.63 ( s, 1H), 6.44(s, 4H), 6.58(s, 2H), 6.70(s, 4H), 6.76(s, 2H), 6.96(s, 2H), 7.05(d, 2H), 7.13-7.24 (m, 16H), 7.32-7.35 (m, 4H), 7.46 (dd, 4H), 8.98 (d, 2H), 10.26 (s, 1H)

¹¹ B-NMR (128 MHz, CDCl ₃ ): δ = 38.5

MALDI-TOF-MS(M ⁺ )=1384.65

Synthesis Example (8):

Synthesis of compound (1-8)

Compound (S-8) (101 mg, 0.072 mmol), 2,6-di-tertiarybutylpyridine (48.0 μL, 0.22 mmol), 1,2, After adding 4-trichlorobenzene (1.0 mL), the mixture was heated and stirred at 60°C for 4 hours. After cooling the reaction solution to room temperature, phosphate buffer (pH = 7) was added to the reaction solution, extraction was performed with dichloromethane (10 mL) 3 times, and the solvent was distilled off under reduced pressure to obtain a crude product. The obtained crude product was subjected to silica gel chromatography (hexane: dichloromethane = 2: 1), and then the solvent was distilled off under reduced pressure to obtain a compound represented by formula (1-8) (20.5 mg, yield 20%) as a yellow solid. got it

¹ H-NMR (500 MHz, CDCl ₃ ): δ = 2.15 (s, 12H), 2.22 (s, 6H), 2.29 (s, 12H), 2.42 (s, 6H), 5.53 (s, 1H), 6.36 ( s, 2H), 6.49(s, 4H), 6.69(s, 6H), 6.77(s, 2H), 6.95(s, 2H), 7.13-7.25(m, 14H), 7.26-7.28(m, 6H) , 7.33-7.36(m, 4H), 7.47(dd, 4H), 8.88(s, 1H)

¹¹ B-NMR (128 MHz, CDCl ₃ ): δ = 44.5

MALDI-TOF-MS(M ⁺ )=1412.68

Other compounds of the present invention can be synthesized by a method according to the synthesis example described above by appropriately changing the compound of the raw material.

<Production and Evaluation of Organic EL Devices>

Next, fabrication and evaluation of an organic EL device using the polycyclic aromatic compound of the present invention will be described.

Evaluation items include driving voltage (V), emission wavelength (nm), CIE chromaticity (x, y), external quantum efficiency (%), maximum wavelength (nm) and full width at half maximum (nm) of the emission spectrum. For these evaluation items, appropriate values at the time of light emission luminance can be used.

The quantum efficiency of the light emitting element includes internal quantum efficiency and external quantum efficiency. The internal quantum efficiency represents the rate at which external energy injected as electrons (or holes) into the light emitting layer of the light emitting element is purely converted into photons. On the other hand, the external quantum efficiency is calculated based on the amount of these photons emitted to the outside of the light emitting element, but a part of the photons generated in the light emitting layer are absorbed or continuously reflected inside the light emitting element, Since it is not emitted to the outside, the external quantum efficiency is lower than the internal quantum efficiency.

The method for measuring spectral radiance (emission spectrum) and external quantum efficiency is as follows. The element was light-emitted by applying a voltage using a voltage/current generator R6144 manufactured by Advantist. Spectroradiance in the visible region was measured from a direction perpendicular to the light emitting surface using a spectroradiometer SR-3AR manufactured by TOPCON. Assuming that the light emitting surface is a completely diffusive surface, the measured spectral radiance value of each wavelength component divided by the wavelength energy and multiplied by π is the number of photons at each wavelength. Next, the number of photons in the entire wavelength range observed was integrated, and the total number of photons emitted from the device was determined. The value obtained by dividing the applied current value by the basic charge is the number of carriers injected into the device, and the value obtained by dividing the total number of photons emitted from the device by the number of carriers injected into the device is the external quantum efficiency. In addition, the half width of the emission spectrum is obtained as the width between the upper and lower wavelengths at which the intensity is 50% with the maximum emission wavelength as the center.

<Example 1-1 to Example 1-2, and Comparative Example 1-1>

Table 1 below shows the material configuration of each layer in the organic EL devices of Examples 1-1 to 1-2 and Comparative Example 1-1.

[Table 1]

In Table 1, "HI" is N ⁴ ,N ^4' -diphenyl-N ⁴ ,N ^4' -bis(9-phenyl-9H-carbazol-3-yl)-[1,1'-biphenyl ] -4,4'-diamine, "HAT-CN" is 1,4,5,8,9,12-hexaazatriphenylenehexacarbonitrile, "HT-1" is N-[1,1 '-biphenyl] -4-yl-9,9-dimethyl-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl] -9H-fluoren-2-amine, "HT -2” is N,N-bis(4-(dibenzo[b,d]furan-4-yl)phenyl)-[1,1′:4′,1″-terphenyl]-4-amine, "BH" is 2-(10-phenylanthracen-9-yl)dibenzo[b,d]furan, and "ET-1" is 9,9'-[(5-(6-(1,1 '-biphenyl)-4-yl)-2-phenylpyrimidin-4-yl)-1,3-phenylene]bis(9H-carbazole), and "ET-2" is 2-ethyl-1- (4-(10-phenylanthracen-9-yl)phenyl)-1H-benzo[d]imidazole, together with "Liq" and Comparative Compound (1) (a compound described in International Publication No. 2015/102118) The chemical structure is shown below.

[Example 1-1]

A 26 mm × 28 mm × 0.7 mm glass substrate (manufactured by Opto Science Co., Ltd.) obtained by polishing ITO to a thickness of 180 nm by sputtering to 120 nm is used as a transparent support substrate. This transparent support substrate was fixed to a substrate holder of a commercially available vapor deposition apparatus (manufactured by Showa Vacuum Co., Ltd.), and HI, HAT-CN, HT-1, HT-2, BH, compound (1-1), ET- A boat for vapor deposition made of molybdenum containing No. 1 and ET-2, and a boat for vapor deposition made of aluminum nitride containing Liq, LiF and aluminum, respectively, were installed.

Each of the following layers is sequentially formed on the ITO film of the transparent support substrate. Depressurize the vacuum chamber to 5×10 ^-4 Pa, first heat HI to deposit a film thickness of 40 nm, then heat HAT-CN to deposit a film thickness of 5 nm, and then heat HT-1 was deposited to a film thickness of 45 nm by heating, and then, HT-2 was heated and deposited to a film thickness of 10 nm to form a four-layered hole layer. Next, BH and compound (1-1) were simultaneously heated and deposited to a film thickness of 25 nm to form a light emitting layer. The deposition rate was adjusted so that the mass ratio of BH and compound (1-1) was about 97:3. Further, ET-1 was heated to deposit a film thickness of 5 nm, and then ET-2 and Liq were simultaneously heated and deposited to a film thickness of 25 nm to form a two-layer electronic layer. The deposition rate was adjusted so that the mass ratio of ET-2 and Liq was about 50:50. The deposition rate of each layer was 0.01 to 1 nm/sec. After that, LiF was heated and deposited at a deposition rate of 0.01 to 0.1 nm/sec to a film thickness of 1 nm, and then aluminum was heated and deposited to a film thickness of 100 nm to form a cathode, thereby obtaining an organic EL device.

[Example 1-2, Comparative Example 1-1]

An organic EL device was obtained in the same manner as in Example 1-1 except for using the compound shown in Table 1 instead of compound (1-1).

[evaluation]

For the organic EL devices of Examples 1-1 to 1-2 and Comparative Example 1-1, DC voltage was applied using the ITO electrode as the anode and the LiF/aluminum electrode as the cathode, and 1000 cd/m ² of light emission Peak wavelength and external quantum efficiency were measured.

The results are shown in Table 2.

[Table 2]

Examples 1-1 to 1-2 exhibited a shorter peak wavelength and higher efficiency than Comparative Example 1-1.

<Examples 2 to 4 and Comparative Examples 2 to 4>

[Comparative Example 2-1]

A 26 mm × 28 mm × 0.7 mm glass substrate (manufactured by Opto Science Co., Ltd.) obtained by polishing ITO film formed to a thickness of 200 nm by sputtering to 120 nm was used as a transparent support substrate. This transparent support substrate was fixed to a substrate holder of a commercially available evaporation device (manufactured by Showa Vacuum Co., Ltd.), and HAT-CN, HTL-1, TcTa, ETL-1, new-DABNA, and ET7 were respectively inserted. An evaporation boat, a tungsten evaporation boat each containing LiF and aluminum was installed.

Each of the following layers was sequentially formed on the ITO film of the transparent support substrate. The vacuum chamber was depressurized to 5×10 ^-4 Pa, and first, HAT-CN was heated and vapor-deposited to a thickness of 5 nm to form a hole injection layer. Next, HTL-1 was heated and deposited to a film thickness of 90 nm to form a hole transport layer 1, and further, TcTa was heated and deposited to a film thickness of 10 nm to form a hole transport layer 2. Next, ETL-1 and new-DABNA were simultaneously heated and deposited to a film thickness of 20 nm to form a light emitting layer. The deposition rate was adjusted so that the mass ratio of ETL-1 and new-DABNA was about 99:1. Next, ETL-1 was heated and deposited to a film thickness of 20 nm to form an electron transport layer 1, and further, ET7 was heated and deposited to a film thickness of 10 nm to form an electron transport layer 2. The deposition rate of each layer was 0.01 to 1 nm/sec. After that, LiF was heated and deposited at a deposition rate of 0.01 to 0.1 nm/sec to a film thickness of 1 nm, and then aluminum was heated and deposited to a film thickness of 100 nm to form a cathode to obtain an organic EL device. At this time, the deposition rate of aluminum was adjusted to be 1 to 10 nm/sec.

[Examples 2-1 to 6]

Organic EL devices of Examples 2-1 to 6 were obtained in the same manner as in Comparative Example 2-1, except that new-DABNA of Comparative Example 2-1 was changed to the compound shown in Table 3.

[Table 3]

[Examples 3-1 to 6, Examples 4-1 to 12, Comparative Examples 3-1 and 4-1 to 2]

ETL-1 (Host) of Comparative Example 2-1 was TcTa and ETL-1 (Host 1 and Host 2) listed in Table 4, and new-DABNA was used as an emitting dopant, or an assisting dopant and an already Each element was fabricated in the same procedure as in Comparative Example 2-1 except for changing the ting dopant.

In each table below, "host 1" corresponds to a hole-transporting host material, and "host 2" corresponds to an electron-transporting host material.

[Table 4]

The chemical structure of the compound used for manufacture of each said element is shown below.

[evaluation]

The peak wavelength and external quantum efficiency of the organic EL devices of Examples 2 to 4 and Comparative Examples 2 to 4 (each Example and Comparative Example shown in Tables 3 and 4) at a luminance of 1000 cd/m ² emission were measured.

The evaluation result of each element is shown in Table 5.

[Table 5]

From comparison with Comparative Examples, it is understood that high-efficiency light emission having a peak at a shorter wavelength is obtained by using a polycyclic aromatic compound having a structure containing the structural unit represented by Formula (1). In addition, high efficiency was obtained with the configuration of Example 3 or Example 4, and the highest efficiency was achieved with the configuration of Example 4.

<Production and evaluation of coating type organic EL device>

Next, an organic EL element obtained by coating and forming an organic layer will be described.

<Polymer Host Compound: Synthesis of SPH-101>

According to the method described in International Publication No. 2015/008851, SPH-101 was synthesized. A copolymer in which M2 or M3 is bonded to the side of M1 is obtained, and from the injection ratio, it is estimated that each unit is 50:26:24 (molar ratio). In the following structural formula, Bpin is pinacolatboril, and * is the connection position of each unit.

<Polymer Hole Transport Compound: Synthesis of XLP-101>

According to the method described in Japanese Unexamined Patent Publication No. 2018-61028, XLP-101 was synthesized. A copolymer in which M5 or M6 is bonded next to M4 is obtained, and it is estimated from the injection ratio that each unit is 40:10:50 (molar ratio). Bpin is pinacolatboril, * is the connection position of each unit.

<Example 5-1 to Example 5-9>

A coating solution for the material forming each layer is prepared to fabricate a coating type organic EL device.

<Production of organic EL devices of Examples 5-1 to 5-3>

Table 6 shows the material configuration of each layer in the organic EL device.

[Table 6]

The structure of "ET1" in Table 6 is shown below.

<Preparation of Composition for Forming Light-Emitting Layer (1)>

The composition for forming a light emitting layer (1) is prepared by stirring the following components until they become a uniform solution. The prepared composition for forming a light-emitting layer is spin-coated on a glass substrate and heat-dried under reduced pressure to obtain a coated film free from film defects and excellent in smoothness.

Compound (A) 0.04% by mass

SPH-101 1.96% by mass

Xylene 69.00% by mass

Decalin 29.00% by mass

In addition, the compound (A) is a polycyclic aromatic compound having a structure composed of one or two or more structural units represented by formula (1) (for example, compound (1-1)), the polycyclic aromatic compound as a monomer (that is, the monomer has a reactive substituent), or a polymer compound obtained by further crosslinking the polymer compound. A polymer compound for obtaining a polymer crosslinked product has a crosslinkable substituent.

<PEDOT:PSS solution>

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

<Preparation of OTPD solution>

OTPD (LT-N159, manufactured by Luminescence Technology Corp.) and IK-2 (photocationic polymerization initiator, manufactured by San-Apro) are 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 .

<Preparation of XLP-101 solution>

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

<Preparation of PCz solution>

PCz (polyvinylcarbazole) is dissolved in dichlorobenzene to prepare a 0.7% by mass PCz solution.

<Example 5-1>

A PEDOT:PSS solution is spin-coated on a glass substrate on which ITO is deposited to a thickness of 150 nm, and fired on a hot plate at 200° C. for 1 hour to form a PEDOT:PSS film with a thickness of 40 nm (hole injection layer). Then, the OTPD solution was spin-coated, dried on a hot plate at 80° C. for 10 minutes, exposed with an exposure machine at an exposure intensity of 100 mJ/cm ² , and baked on a hot plate at 100° C. for 1 hour to obtain a film insoluble in the solution. An OTPD film having a thickness of 30 nm is formed (hole transport layer). Next, the composition for forming a light-emitting layer (1) is spin-coated and baked on a hot plate at 120° C. for 1 hour to form a light-emitting layer having a thickness of 20 nm.

The produced multilayer film is fixed to a substrate holder of a commercially available evaporation device (manufactured by Showa Vacuum Co., Ltd.), and a molybdenum evaporation boat containing ET1, a molybdenum evaporation boat containing LiF, and a tungsten evaporation boat containing aluminum Equip After depressurizing the vacuum chamber to 5×10 ^-4 Pa, ET1 is heated and deposited to a film thickness of 30 nm to form an electron transport layer. The deposition rate at the time of forming the electron transporting layer is 1 nm/sec. After that, LiF is heated and deposited at a deposition rate of 0.01 to 0.1 nm/sec to a film thickness of 1 nm. Next, aluminum is heated and deposited to a film thickness of 100 nm to form a cathode. In this way, an organic EL element is obtained.

<Example 5-2>

An organic EL element was obtained in the same manner as in Example 5-1. Further, the hole transport layer is formed by spin-coating an XLP-101 solution and baking it on a hot plate at 200°C for 1 hour to form a film having a thickness of 30 nm.

<Example 5-3>

An organic EL element was obtained in the same manner as in Example 5-1. Further, the hole transport layer is formed by spin-coating a PCz solution and baking it on a hot plate at 120° C. for 1 hour to form a film having a thickness of 30 nm.

<Evaluation of organic EL devices of Examples 5-1 to 5-3>

The coating type organic EL device obtained as described above can be expected to have excellent driving voltage and external quantum efficiency similarly to the vapor deposition type organic EL device.

<Production of organic EL devices of Examples 5-4 to 5-6>

Table 7 shows the material configuration of each layer in the organic EL device.

[Table 7]

<Preparation of Compositions (2) to (4) for Forming Light Emitting Layer>

A composition for forming a light emitting layer (2) is prepared by stirring the following components until they become a uniform solution.

Compound (A) 0.02% by mass

mCBP 1.98% by mass

Toluene 98.00% by mass

The composition for forming a light emitting layer (3) is prepared by stirring the following components until they become a uniform solution.

Compound (A) 0.02% by mass

SPH-101 1.98% by mass

Xylene 98.00% by mass

The composition for forming a light emitting layer (4) is prepared by stirring the following components until they become a uniform solution.

Compound (A) 0.02% by mass

DOBNA 1.98% by mass

Toluene 98.00% by mass

In Table 7, "mCBP" is 3,3'-bis(N-carbazolyl)-1,1'-biphenyl, and "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 structure is shown below.

<Example 5-4>

After spin-coating a solution of ND-3202 (manufactured by Nissan Chemical Industries, Ltd.) on a glass substrate on which ITO was formed to a thickness of 45 nm, heating at 50 ° C. for 3 minutes and further heating at 230 ° C. for 15 minutes in an air atmosphere, An ND-3202 film with a film thickness of 50 nm is formed (hole injection layer). Next, the XLP-101 solution is spin-coated and heated on a hot plate at 200 DEG C for 30 minutes in a nitrogen gas atmosphere to form an XLP-101 film with a thickness of 20 nm (hole transport layer). Next, the composition for forming a light emitting layer (2) is spin-coated and heated at 130° C. for 10 minutes in a nitrogen gas atmosphere to form a 20 nm light emitting layer.

The produced multilayer film is fixed to a substrate holder of a commercially available evaporation device (manufactured by Showa Vacuum Co., Ltd.), and a molybdenum evaporation boat containing TSPO1, a molybdenum evaporation boat containing LiF, and a tungsten evaporation boat containing aluminum Equip After depressurizing the vacuum chamber to 5×10 ^-4 Pa, TSPO1 is heated and evaporated to a film thickness of 30 nm to form an electron transport layer. The deposition rate at the time of forming the electron transporting layer is 1 nm/sec. After that, LiF is heated and deposited at a deposition rate of 0.01 to 0.1 nm/sec to a film thickness of 1 nm. Next, aluminum is heated and deposited to a film thickness of 100 nm to form a cathode. In this way, an organic EL element is obtained.

<Example 5-5 and Example 5-6>

An organic EL element was obtained in the same manner as in Example 5-4 using the composition for forming a light emitting layer (3) or (4).

<Evaluation of organic EL devices of Examples 5-4 to 5-6>

The coating type organic EL device obtained as described above can be expected to have excellent driving voltage and external quantum efficiency similarly to the vapor deposition type organic EL device.

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

Table 8 shows the material configuration of each layer in the organic EL device.

[Table 8]

<Preparation of Compositions (5) to (7) for Forming Light Emitting Layer>

The composition for forming a light emitting layer (5) is prepared by stirring the following components until they become a uniform solution.

Compound (A) 0.02% by mass

2PXZ-TAZ 0.18% by mass

mCBP 1.80% by mass

Toluene 98.00% by mass

A composition for forming a light emitting layer (6) is prepared by stirring the following components until they become a uniform solution.

Compound (A) 0.02% by mass

2PXZ-TAZ 0.18% by mass

SPH-101 1.80% by mass

Xylene 98.00% by mass

A composition for forming a light emitting layer (7) is prepared by stirring the following components until they become a uniform solution.

Compound (A) 0.02% by mass

2PXZ-TAZ 0.18% by mass

DOBNA 1.80% by mass

Toluene 98.00% by mass

In Table 8, "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.

<Example 5-7>

After spin-coating a solution of ND-3202 (manufactured by Nissan Chemical Industries, Ltd.) on a glass substrate on which ITO was formed to a thickness of 45 nm, heating at 50 ° C. for 3 minutes and further heating at 230 ° C. for 15 minutes in an air atmosphere, An ND-3202 film with a film thickness of 50 nm is formed (hole injection layer). Next, the XLP-101 solution is spin-coated and heated on a hot plate at 200 DEG C for 30 minutes in a nitrogen gas atmosphere to form an XLP-101 film with a thickness of 20 nm (hole transport layer). Next, a 20 nm light emitting layer is formed by spin-coating the composition 5 for forming a light emitting layer and heating it at 130° C. for 10 minutes in a nitrogen gas atmosphere.

The produced multilayer film is fixed to a substrate holder of a commercially available evaporation device (manufactured by Showa Vacuum Co., Ltd.), and a molybdenum evaporation boat containing TSPO1, a molybdenum evaporation boat containing LiF, and a tungsten evaporation boat containing aluminum Equip After depressurizing the vacuum chamber to 5×10 ^-4 Pa, TSPO1 is heated and evaporated to a film thickness of 30 nm to form an electron transport layer. The deposition rate at the time of forming the electron transporting layer is 1 nm/sec. After that, LiF is heated and deposited at a deposition rate of 0.01 to 0.1 nm/sec to a film thickness of 1 nm. Next, aluminum is heated and deposited to a film thickness of 100 nm to form a cathode. In this way, an organic EL element is obtained.

<Example 5-8 and Example 5-9>

An organic EL element was obtained in the same manner as in Example 5-7 using the composition for forming a light emitting layer (6) or (7).

<Evaluation of organic EL devices of Examples 5-7 to 5-9>

The coating type organic EL device obtained as described above can be expected to have excellent driving voltage and external quantum efficiency similarly to the vapor deposition type organic EL device.

100 organic electroluminescent device
101 substrate
102 anode
103 hole injection layer
104 hole transport layer
105 light emitting layer
106 electron transport layer
107 electron injection layer
108 Cathode

Claims (18)

polycyclic aromatic compounds having a structure composed of one or two or more structural units represented by the following formula (1);

In formula (1),
A ring, B ring, and C ring are each independently a substituted or unsubstituted aryl ring or a substituted or unsubstituted heteroaryl ring, provided that at least one selected from the group consisting of A ring, B ring, and C ring is an aryl ring substituted with a group represented by formula (1R) or a heteroaryl ring substituted with a group represented by formula (1R),
In formula (1R), ring F, ring G, and ring H are each independently a substituted or unsubstituted aryl ring or a substituted or unsubstituted heteroaryl ring, * is a bonding position,
Y is >B-, >P-, >P(=O)-, >P(=S)-, >Al-, >Ga-, >As-, >C(-R ^Y )-, >Si( -R ^Y )-, or >Ge(-R ^Y )-, and R ^Y each independently represents optionally substituted aryl, optionally substituted heteroaryl, optionally substituted alkyl, or optionally substituted cyclo is an alkyl,
X is each independently >NR ^X , >O, >S, >C(-R ^X ) ₂ , >Si(-R ^X ) ₂ , or >Se, and R ^X is each independently hydrogen, substituted optionally substituted aryl, optionally substituted heteroaryl, optionally substituted alkyl, or optionally substituted cycloalkyl, >C(-R ^X ) ₂ of two R ^X and >Si(-R ^X ) ₂ of Two R ^X 's may be bonded by a single bond or a linking group, respectively;
R ^X in X may be bonded to one or two selected from the group consisting of A ring, B ring, and C ring by a single bond or a linking group;
In the above structure, at least one selected from the group consisting of an aryl ring and a heteroaryl ring may be condensed with at least one cycloalkane, and the cycloalkane may be substituted with at least one substituent, and the cycloalkane At least one -CH ₂ - in may be substituted with -O-,
At least one hydrogen in the above structure may be substituted with heavy hydrogen, cyano or halogen. According to claim 1,
Substituents other than the group represented by formula (1R) as substituents when A ring, B ring, C ring, F ring, G ring, and H ring are substituted aryl rings or substituted heteroaryl rings are substituent group Z and formula ( At least one substituent selected from the group consisting of substituents represented by A30),
Substituent group Z is,
aryl which may be substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl and cycloalkyl;
heteroaryl which may be substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl and cycloalkyl;
diarylamino which may be substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl and cycloalkyl (two aryls may be bonded to each other via a linking group);
diheteroarylamino which may be substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl and cycloalkyl (two heteroaryls may be bonded to each other through a linking group);
arylheteroarylamino which may be substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl and cycloalkyl (aryl and heteroaryl may be bonded to each other through a linking group);
diarylboryl which may be substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl and cycloalkyl (two aryls may be bonded via a single bond or a linking group);
alkyl which may be substituted with at least one group selected from the group consisting of aryl, heteroaryl and cycloalkyl;
cycloalkyl which may be substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl and cycloalkyl;
alkoxy which may be substituted with at least one group selected from the group consisting of aryl, heteroaryl and cycloalkyl;
aryloxy which may be substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl and cycloalkyl; and
Consists of substituted silyl,

In formula (A30),
Ak is hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted cycloalkyl, or substituted or unsubstituted cycloalkenyl, and the corresponding alkyl, alkenyl, cycloalkyl and cycloalkenyl At least one -CH ₂ - in may be substituted with -O- or -S-;
R ^Ak is a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted alkyl, or a substituted or unsubstituted cycloalkyl, and R ^Ak is bonded to Ak by a linking group or a single bond. And, * is a bonding position, a polycyclic aromatic compound. According to claim 2,
polycyclic aromatic compounds in which the group represented by formula (1R) is a group represented by formula (2R);

In formula (2R),
R ^AZ is each independently hydrogen, any substituent selected from substituent group Z, or a substituent represented by formula (A30), together with the ring to which adjacent R ^AZ is bonded to which they are directly bonded, an aryl ring or A heteroaryl ring may be formed, and the formed ring may be substituted with at least one substituent selected from the group consisting of substituent group Z and a substituent represented by formula (A30). According to claim 3,
A polycyclic aromatic compound in which all of R ^AZ are hydrogen. According to any one of claims 2 to 4,
Formula (2A), Formula (2B), Formula (2C), Formula (2D), Formula (2E), Formula (2F), Formula (2G), Formula (2H), Formula (2I), Formula (2J), Or a polycyclic aromatic compound represented by formula (2K).

In the above formula,
R ^Z is each independently hydrogen, any substituent selected from substituent group Z, or a substituent represented by formula (A30), and adjacent R ^Z are bonded together with the ring to which they are directly bonded together to form an aryl ring or hetero An aryl ring may be formed, and the formed ring may be substituted with at least one substituent ^RZ2 selected from the group consisting of substituent group Z and a substituent represented by formula (A30),
However, in each formula, at least one selected from the group consisting of R ^Z and substituent R ^Z2 is a group represented by formula (1R),
L is >NR ^L , >O, or >S, R ^L is hydrogen, aryl which may be substituted with alkyl or cycloalkyl, heteroaryl which may be substituted with alkyl or cycloalkyl, even if substituted with cycloalkyl alkyl, or cycloalkyl which may be substituted with alkyl or cycloalkyl,
Formula (2A), Formula (2B), Formula (2C), Formula (2D), Formula (2E), Formula (2F), Formula (2G), Formula (2H), Formula (2I), Formula (2J), Or, in the structure represented by formula (2K), at least one selected from the group consisting of an aryl ring and a heteroaryl ring may be condensed with at least one cycloalkane, and the cycloalkane is aryl, heteroaryl, may be substituted with alkyl or cycloalkyl, and at least one -CH ₂ - in the cycloalkane may be substituted with -O-;
Formula (2A), Formula (2B), Formula (2C), Formula (2D), Formula (2E), Formula (2F), Formula (2G), Formula (2H), Formula (2I), Formula (2J), Alternatively, at least one hydrogen in the structure represented by formula (2K) may be substituted with heavy hydrogen, cyano or halogen. According to claim 5,
A polycyclic aromatic compound in which one or two of R ^Z at the para position of Y are a group represented by formula (1R). According to claim 5 or 6,
A polycyclic aromatic compound wherein L is >S. According to any one of claims 5 to 7,
A polycyclic aromatic compound represented by formula (2A), formula (2E), formula (2G) or formula (2H). According to claim 8,
polycyclic aromatic compounds represented by any of the following formulas;

In the formula, Me is methyl and tBu is t-butyl. A high molecular compound having a number average molecular weight of 2000 to 10 ⁸ obtained by polymerizing a reactive compound in which a reactive substituent is substituted for the polycyclic aromatic compound according to any one of claims 1 to 9 as a monomer. A composition comprising the polymer compound according to claim 10 and an organic solvent. A material for organic devices containing the polycyclic aromatic compound according to any one of claims 1 to 9 or the high molecular compound according to claim 10. According to claim 12,
The material for an organic device, 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. A pair of electrodes comprising an anode and a cathode and an organic layer disposed between the pair of electrodes, wherein the organic layer is the polycyclic aromatic compound according to any one of claims 1 to 9 or the polymer compound according to claim 10 Containing, an organic electroluminescent device. According to claim 14,
An organic electroluminescent device in which the organic layer is a light emitting layer. According to claim 15,
An organic electroluminescent device comprising a host material having a lowest excitation triplet energy level of 2.70 eV or more in the light emitting layer. According to claim 15,
An organic electroluminescent device comprising an anthracene-based compound in the light emitting layer. A display device or lighting device provided with the organic electroluminescent element according to any one of claims 14 to 17.

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