KR20230046221A - Polycyclic aromatic compound - Google Patents

Abstract

Provided is a useful novel compound as an organic device material such as an organic EL device. Provided is a polycyclic aromatic compound having a structure including a structure unit represented by a formula (1). Ring A and ring B are each independently a substituted or unsubstituted aryl ring or heteroaryl ring. Ring C is a substituted or unsubstituted hydrocarbon ring or heterocyclic ring. X^1 is >N-R (R is aryl). A broken line represents a divalent group for connecting two nitrogen atoms. In the structure, at least one hydrogen is substituted with cyano, halogen, or deuterium.

Description

Polycyclic aromatic compound {POLYCYCLIC AROMATIC COMPOUND}

The present invention relates to polycyclic aromatic compounds. The present invention particularly relates to polycyclic aromatic compounds containing nitrogen and boron. The present invention also relates to a material for an organic device, an organic electroluminescent device, and a display device and a lighting device including the polycyclic aromatic compound.

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 novel compound useful as an organic device material 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 containing a structural unit represented by the following formula (1);

In formula (1),

Ring A and ring B are each independently a substituted or unsubstituted aryl ring or a substituted or unsubstituted heteroaryl ring,

C ring is a substituted or unsubstituted hydrocarbon ring or a substituted or unsubstituted hetero ring;

X ¹ is >O, >NR, >C(-R) ₂ , >Si(-R) ₂ , >S, or >Se, wherein R in >NR is hydrogen, substituted or unsubstituted aryl, substituted Or unsubstituted heteroaryl, substituted or unsubstituted alkyl, or substituted or unsubstituted cycloalkyl, wherein R in >C(-R) ₂ and >Si(-R) ₂ is each independently hydrogen, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted alkyl, or substituted or unsubstituted cycloalkyl, wherein >C(-R) ₂ and >Si(-R) ₂ of 2 The two R's may be bonded to each other to form a ring, and the R of >NR, the >C(-R) ₂ and the R of >Si(-R) ₂ are ring A and/or by a linking group or a single bond. It may be bonded to ring B,

The broken line represents a divalent group linking two nitrogen atoms, and the divalent group may be bonded to the A ring and/or the C ring,

In the above structure, at least one of the aryl ring or heteroaryl ring may be condensed with at least one cycloalkane, the cycloalkane may be substituted with at least one substituent, and at least one of the cycloalkanes -CH ₂ - of may be substituted with -O-;

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

<2> The polycyclic aromatic compound according to <1>, wherein the divalent group connecting two nitrogen atoms is represented by the following formula;

D ring is a substituted or unsubstituted hydrocarbon ring or a substituted or unsubstituted hetero ring, two * indicates the bonding position with two nitrogen atoms,

Ring D may be further bonded to ring A and/or ring C through a linking group or single bond.

<3> Formula (1-a), Formula (1-b), Formula (1-c), Formula (1-d), Formula (1-f), Formula (1-g), Formula (1- h) and the polycyclic aromatic compound according to <2>, represented by any one formula selected from the group consisting of formula (1-i);

Formula (1-a), Formula (1-b), Formula (1-c), Formula (1-d), Formula (1-f), Formula (1-g), Formula (1-h), and In formula (1-i),

Z is each independently N or CR ^Z , R ^Z is each independently hydrogen or any one substituent selected from substituent group Z,

Two adjacent R ^Z may be bonded to each other to form an aryl ring or heteroaryl ring, and each of the formed aryl ring or heteroaryl ring may be substituted with any one substituent selected from substituent group Z,

Z=Z may each independently be >O, >NR, >C(-R) ₂ , >Si(-R) ₂ , >S, or >Se, wherein >NR and >C(-R) ₂ , and R in >Si(-R) ₂ are each independently hydrogen, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted alkyl, or substituted or unsubstituted cycloalkyl, The two Rs of >C(-R) ₂ and >Si(-R) ₂ may be bonded to each other to form a ring;

X ² and X ⁴ are each independently >O, >NR, >C(-R) ₂ , >S, or >Se, wherein R in >NR is hydrogen, substituted or unsubstituted aryl, substituted or unsubstituted A substituted heteroaryl, a substituted or unsubstituted alkyl, or a substituted or unsubstituted cycloalkyl, wherein each R in >C(-R) ₂ is independently hydrogen, a substituted or unsubstituted aryl, or a substituted or unsubstituted hetero aryl, substituted or unsubstituted alkyl, or substituted or unsubstituted cycloalkyl, wherein >NR and >C(-R) ₂ are one or two or more Z bonded to the same carbon atom, and R may be combined in

In the above structure, at least one of the aryl ring or heteroaryl ring may be condensed with at least one cycloalkane, the cycloalkane may be substituted with at least one substituent, and at least one of the cycloalkanes -CH ₂ - of may be substituted with -O-;

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

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

made from substituted silyl.

<4> Z is CR ^Z ,

The polycyclic aromatic compound according to <3>, wherein all of X ² are >NR, and X ⁴ is >O, >NR, or >S.

<5> R ^Z is each independently hydrogen, alkyl, phenyl which may be substituted with alkyl, diphenylamino which may be substituted with alkyl, or carbazolyl which may be substituted with alkyl, <3> or <4 The polycyclic aromatic compound described in >.

<6> Represented by any one formula selected from the group consisting of formula (1-f), formula (1-g), formula (1-h), and formula (1-i), <3> to < The polycyclic aromatic compound according to any one of 5>.

<7> polycyclic aromatic compound according to <1> represented by any of the following formulas;

In the formula, tBu is t-butyl.

<8> Represented by any one formula selected from the group consisting of formula (1-a), formula (1-b), formula (1-c), and formula (1-d), <3> to < It is the polycyclic aromatic compound described in any one of 5>,

Any one formula selected from the group consisting of Formula (B101), Formula (B102), Formula (B103), Formula (B104), Formula (B105), Formula (B106), Formula (B107), and Formula (B108) A polycyclic aromatic compound containing at least one partial structure represented by;

during the ceremony,

Z has the same meaning as Z in formulas (1-a), (1-b), (1-c), and (1-d);

X ⁵ is >O, >NR, >C(-R) ₂ , >S, or >Se, wherein R of >NR is hydrogen, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted alkyl, substituted or unsubstituted cycloalkyl, wherein R in >C(-R) ₂ is each independently hydrogen, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted Alkyl or substituted or unsubstituted cycloalkyl, >C(-R) ₂ Two R's may be bonded to each other to form a ring, n is an integer of 1 to 3,

Me is methyl.

<9> polycyclic aromatic compounds according to <8> represented by any of the following formulas;

In the formula, Me is methyl, tBu is t-butyl, Ad is 1-adamantyl, and tAm is t-amyl.

<10> Polycyclic aromatic compounds having a structure containing a structural unit represented by Formula (2);

In formula (2),

Z is each independently N or CR ^Z , R ^Z is each independently hydrogen or any one substituent selected from substituent group Z,

Two adjacent ^RZs may be bonded to each other to form an aryl ring or heteroaryl ring, and the formed aryl ring or heteroaryl ring may each be substituted with any one substituent selected from substituent group Z,

At least one selected from the group consisting of substituents of rings formed by bonding R ^Z and adjacent R ^Z are selected from the group consisting of formula (A-1), formula (A-2) and formula (A-3) It is a group represented by the formula,

Z=Z may each independently be >O, >NR, >C(-R) ₂ , >Si(-R) ₂ , >S, or >Se, wherein >NR and >C(-R) ₂ And R of >Si(-R) ₂ is each independently hydrogen, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted alkyl, or substituted or unsubstituted cycloalkyl, wherein >C(-R) ₂ and the two Rs of >Si(-R) ₂ may be bonded to each other to form a ring;

In formula (A-1),

W ¹ and W ² are each independently a single bond, >C(-R ^W ) ₂ , >NR ^W , >O, >Si(-R ^W ) ₂ , >S, >SO or >SO ₂ ,

R ^W of >NR ^W is any substituent selected from substituent group Z, a group represented by formula (A-2), or a group represented by formula (A-3),

R ^W of >C(-R ^W ) ₂ and >Si(-R ^W ) ₂ are each independently hydrogen, any one substituent selected from substituent group Z, a group represented by formula (A-2), or It is a group represented by formula (A-3),

R ^W bonded to the same element may be bonded to each other,

R W of >NR ^W , >C(-R ^W ) ₂ , and >Si(-R ^{W )} ₂ may be each independently bonded to at least one Y;

Y is N or CR ^Y , R ^Y is each independently hydrogen, any substituent selected from substituent group Z, a group represented by formula (A-2), or a group represented by formula (A-3) is,

R ^Y in adjacent Y may be bonded to each other to form an aryl ring or a heteroaryl ring, and the formed ring is any one of substituents selected from the substituent group Z, a group represented by formula (A-2), or a formula It may have a group represented by (A-3),

L ¹ is a single bond or a linking group;

L ¹ is bonded to C of any one CR ^Y with R ^Y as a bond hand, or >C(-R ^{W )} C of ₂ , >NR N of ^W , >O, > with R W as a bond hand Is bonded to Si of Si(-R ^W ) ₂ , or is bonded to a ring constituting atom of a ring formed by bonding R ^Y in Y to each other;

* represents the bonding position of the group represented by formula (A-1),

In formula (A-2),

Y is N or CR ^Y , R ^Y is each independently hydrogen, any substituent selected from substituent group Z, a group represented by formula (A-1), or a group represented by formula (A-3) ego,

R ^Y in adjacent Y may be bonded to each other to form an aryl ring or a heteroaryl ring, and the formed ring is any one of substituents selected from substituent group Z, a group represented by formula (A-1), or a formula may have a group represented by (A-3);

L ² is a single bond or a linking group;

L ² is bonded to C of any C R ^Y with R ^Y as a bond hand, or bonded to a ring-constituting atom of a ring formed by bonding R ^Y in Y to each other;

* represents the bonding position of the group represented by formula (A-2),

In formula (A-3),

Ar ³ is each independently selected from at least one substituent selected from substituent group Z, aryl optionally substituted with a group represented by formula (A-1) or formula (A-2), and at least one selected from substituent group Z a heteroaryl which may be substituted with a substituent or a group represented by formula (A-1) or formula (A-2), or a group represented by formula (A-1) or formula (A-2);

W ³ is Si, P or S;

When W ³ is Si, m is 3 and n is 0. When W ³ is P, m is 2 and n is 0 or 1. When W ³ is S, m is 1 and n is 0 to 2. is an integer of

L ³ is a single bond or a linking group;

* represents the bonding position of the group represented by formula (A-3),

In the above structure, at least one of the aryl ring or heteroaryl ring may be condensed with at least one cycloalkane, and at least one hydrogen in the cycloalkane may be substituted, and in the cycloalkane At least one -CH ₂ - may be substituted with -O-;

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

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

made from substituted silyl.

<11> L ¹ , L ² and L ³ are each independently a single bond or arylene which may be substituted with aryl or heteroaryl, heteroarylene which may be substituted with aryl or heteroaryl, >NR ^L , >O, >C(-R ^L ) ₂ , >Si(-R ^L ) ₂ , >S, >Se, and a linking group selected from the group consisting of two or more combinations thereof,

R L in > ^{NR L} , >C(-R ^L ) ₂ and >Si(-R ^L ) ₂ in L ¹ , L ² and L ³ is each independently selected from hydrogen and substituent group Z. It is a single substituent or a group represented by formula (A-1), formula (A-2) or formula (A-3), and R ^L bonded to the same element may be bonded to each other, polycyclic described in <10> aromatic compounds.

<11-2> A group represented by a formula in which one or two of R ^Z in formula (2) are selected from the group consisting of formula (A-1), formula (A-2) and formula (A-3) However, when R ^Z are bonded to each other to form a ring, one or two selected from the group consisting of the substituent of the ring and R ^Z are formulas (A-1), formulas (A-2) and The polycyclic aromatic compound according to <10> or <11>, which is a group represented by a formula selected from the group consisting of formula (A-3).

<12> In formula (2), at least one of R ^Z is a group represented by formula (A-1), provided that, when R ^Z are bonded to each other to form a ring, the substituent of the ring and R ^Z At least one selected from the group consisting of is a group represented by formula (A-1),

W ¹ is >NR ^W , >C(-R ^W ) ₂ , >O, >Si(-R ^W ) ₂ , or >S, and W ² is a single bond, <10> to <11>, <11- The polycyclic aromatic compound according to any one of 2>.

<13> L ¹ is a single bond, W ¹ is >NR ^W ,

L ¹ is bonded to N of >NR ^W with R ^W as a bond,

The polycyclic aromatic compound according to <12>, which contains at least one group represented by formula (A-2), group represented by formula (A-3), or R ^Y that is N-carbazolyl.

<14> In formula (2), at least one of R ^Z is a group represented by formula (A-2), provided that when R ^Z are bonded to each other to form a ring, the substituent of the ring and R ^Z At least one selected from the group consisting of is a group represented by formula (A-2),

The polycyclic ring according to any one of <10> to <13> and <11-2>, wherein the group represented by Formula (A-2) contains, as a partial structure, a pyridine ring, a pyrimidine ring, a pyrazine ring, or a triazine ring. aromatic compounds.

<15> In formula (2), at least one of ^RZ is a group represented by formula (A-3), provided that when ^RZs are bonded to each other to form a ring, the group substituting the ring and ^RZ At least one selected from the group consisting of is a group represented by formula (A-3),

The polycyclic aromatic compound according to any one of <10> to <14> and <11-2>, wherein W ³ is Si.

<16> The polycyclic aromatic compound according to <13>, represented by any of the following formulas.

<17> A material for organic devices containing the polycyclic aromatic compound according to any one of <1> to <16> and <11-2>.

<18> A pair of electrodes composed of an anode and a cathode, and an organic layer (preferably a light emitting layer) disposed between the pair of electrodes, wherein the organic layer is any one of <1> to <16> and <11-2>. An organic electroluminescent element containing the polycyclic aromatic compound described in one.

<19> has a pair of electrodes composed of an anode and a cathode and a light emitting layer disposed between the pair of electrodes,

The light-emitting layer contains a host material and the polycyclic aromatic compound according to any one of <1> to <9>;

The organic electroluminescent device, wherein the lowest excitation triplet energy level of the host material is higher than the lowest excitation triplet energy level of the polycyclic aromatic compound.

<20> A pair of electrodes composed of an anode and a cathode and a light emitting layer disposed between the pair of electrodes, wherein the light emitting layer is selected from the group consisting of a hole transporting host material, an electron transporting host material, and an assisting dopant at least two and an emitting dopant;

An organic electroluminescent device in which the above-mentioned emitting dopant is the polycyclic aromatic compound according to any one of <1> to <9>.

<21> has a pair of electrodes composed of an anode and a cathode and a light emitting layer disposed between the pair of electrodes;

The light-emitting layer contains the polycyclic aromatic compound according to any one of <10> to <16> and <11-2> as a dopant material and a host material,

The lowest excitation triplet energy level of the polycyclic aromatic compound is higher than the lowest excitation triplet energy level of the dopant material.

<22> A display device or lighting device provided with the organic electroluminescent element according to any one of <18> to <21>.

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 expressed 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" is phenyl, "Mes" is mesityl (2,4,6-trimethylphenyl), "Ad" is 1-adamantyl, "Tf" is trifluoromethanesulfonyl, "TMS" is trimethylsilyl, "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.

0. Description of rings and substituents

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

Examples of the "hydrocarbon ring" in the present specification include a cycloalkane ring and a cycloalkene ring in addition to the "aryl ring" described later. Specific examples of the cycloalkane ring include a cyclopentane ring and a cyclohexane ring. Specific examples of the cycloalkene ring include a cyclopentene ring, a cyclohexene ring, a 1,3-cyclohexadiene ring, and a 1,4-cyclohexadiene ring.

Examples of the "heterocycle" in the present specification include non-aromatic heterocycles other than the "heteroaryl rings" described later. Examples of the non-aromatic heterocyclic ring include a piperidine ring, a piperazine ring, and a morpholine ring.

As the "aryl ring" in the present specification (for example, the "aryl ring" in the A ring, B ring, or C ring of formula (1)), for example, an aryl ring having 6 to 30 carbon atoms is exemplified. An aryl ring having 6 to 16 carbon atoms is preferable, an aryl ring having 6 to 12 carbon atoms is more preferable, and an aryl ring having 6 to 10 carbon atoms is particularly preferable.

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, and a dimethylfluorene ring, dimethylbenzofluorene Rings and dimethylindene rings are also included.

As the "heteroaryl ring" in the present specification (for example, the "heteroaryl ring" in the A ring, B ring, or C ring of Formula (1)), for example, a heteroaryl ring having 2 to 30 carbon atoms. An aryl ring is included, a heteroaryl ring having 2 to 25 carbon atoms is preferable, a heteroaryl ring having 2 to 20 carbon atoms is more preferable, a heteroaryl ring having 2 to 15 carbon atoms is still more preferable, and a heteroaryl ring having 2 to 10 carbon atoms A ring is particularly preferred. Examples of the "heteroaryl ring" include heterocycles containing 1 to 5 heteroatoms selected from oxygen, sulfur and nitrogen 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, naphthyridine 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 Benzodioxine ring, dioxabora naphthoanthracene ring (5,9-dioxa-13b-bora-13bH-naphtho [3,2,1-de] anthracene ring, etc.), benzoselenophene ring, dibenzoselenium Nophen ring, azacarbazole ring, azadibenzothiophene ring, azadibenzofuran ring, azadibenzoselenophene ring, azatriphenylene ring, imidazoimidazole ring, indoloindole ring, benzofurocarbazole ring, A benzothienocarbazole ring, an indenocarbazole ring, a selenophenocarbazole ring, a spiro[fluorene-9,9'-xanthene] ring, a spirovi[silafluorene] 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 are substituted with an alkyl such as methyl as a first substituent described later, respectively, and a dimethyldihydroacridine ring, a dimethylxanthene ring, It is also preferable to be a dimethylthioxanthene ring or the like. Examples of "heteroaryl rings" include bipyridine rings, phenylpyridine rings, and pyridylphenyl rings, 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

made from 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 considered "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, preferably 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 examples of "aryl" include monovalent groups obtained by removing one hydrogen from the "aryl ring" described above. For example, monocyclic phenyl, bicyclic biphenylyl (2-biphenylyl, 3-biphenylyl, or 4-biphenylyl), condensed bicyclic naphthyl (1-naphthyl or 2-naphthyl) ethyl), 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-ter Phenyl-2-yl, o-terphenyl-3-yl, o-terphenyl-4-yl, p-terphenyl-2-yl, p-terphenyl-3-yl, or p-terphenyl-4- 1), 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-)yl, Quaternary phenylyl (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 condensed pentacyclic, perylene-(1-, 2-, or 3-)yl, or pentacene-(1-, 2-, 5-, or 6-)yl, and the like. . 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 15 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 monovalent groups obtained by removing one hydrogen from the "heteroaryl ring" described above. For example, pyrrolyl, oxazolyl, isoxazolyl, thiazolyl, isothiazolyl, imidazolyl, oxadiazolyl, thiadiazolyl, triazolyl, tetrazolyl, pyrazolyl, pyridyl, pyrimidinyl, pyr Dazinyl, pyrazinyl, triazinyl, indolyl, isoindoleyl, 1H-indazolyl, benzoimidazolyl, benzooxazolyl, benzothiazolyl, 1H-benzotriazolyl, quinolinyl, isoquinolinyl, synth Nolinyl, quinazolinyl, quinoxalinyl, phenanthrolinyl, phthalazinyl, naphthyridinyl, purinyl, pteridinyl, carbazolyl, acridinyl, phenoxathynyl, phenoxazinyl, phenothiazinyl , phenazinyl, phenazacillinyl, indolizinil, furanil, benzofuranil, isobenzofuranil, dibenzofuranil, naphthobenzofuranil, thienyl, benzothienyl, isobenzothienyl, dibenzo Thienyl, naphthobenzothienyl, monovalent group of benzophosphole oxide ring, monovalent group of dibenzophosphole oxide ring, furazanyl, thianthrenyl, indolocarbazolyl, benzoindolocarbazolyl, dibenzo indolocarbazolyl, 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, heteroarylene having 2 to 30 carbon atoms, preferably heteroarylene having 2 to 25 carbon atoms, heteroarylene having 2 to 20 carbon atoms, and 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 through 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 together to form no further 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 addition, in the present specification, when simply described as “diarylamino,” “diheteroarylamino,” or “arylheteroarylamino,” unless otherwise specified, each “two aryls of diarylamino are a linking group may be bonded through", "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 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. Moreover, two adjacent Rs may form a ring, and may 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 either straight chain or branched chain, 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 (C 3 to 24 carbon atoms). 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) to 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-methyl heptyl, 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 substituted with 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 alkathien-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, or a cycloalkyl of 3 to 12 carbon atoms. cycloalkyl, cycloalkyl of 5 to 10 carbon atoms, cycloalkyl of 5 to 8 carbon atoms, cycloalkyl of 5 to 6 carbon atoms, or cycloalkyl of 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-C10 cycloalkylene, C5-C8 cycloalkylene, C5-C6 cycloalkylene, or C5 cycloalkylene.

Specific examples of "cycloalkylene" include divalent groups obtained by removing one hydrogen from the aforementioned "cycloalkyls" (monovalent groups).

"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, methyl di-n-propylsilyl, ethyl di-n-propylsilyl, n-butyldi n- 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 as the linking group, -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. Moreover, two adjacent Rs may form a ring, and may form cycloalkylene, arylene, and 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, 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 polycyclic aromatic compound of the present invention is a polycyclic aromatic compound having a structure including a structural unit represented by formula (1).

In formula (1),

Ring A and ring B are each independently a substituted or unsubstituted aryl ring or a substituted or unsubstituted heteroaryl ring,

Ring C is a substituted or unsubstituted hydrocarbon ring or a substituted or unsubstituted hetero ring, and the broken line represents a divalent group connecting two nitrogen atoms.

The polycyclic aromatic compound of the present invention has a skeleton similar to that of the boron-containing polycyclic aromatic compound described in International Publication No. 2015/102118. As described in International Publication No. 2015/102118, a polycyclic aromatic compound in which an aromatic ring is linked with a hetero element such as boron, nitrogen, oxygen, or sulfur has a large HOMO-LUMO gap (band gap Eg in a thin film) It is known. 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. It is also known that the polycyclic aromatic compound can arbitrarily change the HOMO-LUMO gap depending on the type of hetero element and the connection method. This is thought to be caused by the fact that the energies of HOMO and LUMO can be arbitrarily moved according to the spatial spread 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.

In the compound having the structure represented by formula (1), by having a structure in which a nitrogen-containing 5-membered ring is further introduced into the skeleton and boron (B) is bonded to the 3rd position, from N to B of the nitrogen-containing 5-membered ring Electron donation occurs, and the CB bond is stabilized. In addition, by donating electrons to boron, the LUMO localized on the aromatic ring in the structure becomes shallow, the gap Eg widens, and the wavelength is shortened. Furthermore, the multiple resonance effect of boron (electron-withdrawing property) and nitrogen (electron-donating property) is enhanced, resulting in sharpening of the spectrum and reduction of ΔE _S1T1 .

The polycyclic aromatic compound of the present invention has a condensed ring structure in which more rings are condensed at the broken line portion, so that the molecule is rigid and the light emission quantum yield is improved. With such a structure, bonds that are easily broken are reduced, molecules are more stable, and driving life when made into a device is increased. By having a large condensed ring system while maintaining a high lowest triplet excitation energy level (E _T1 ), the carrier mobility is increased, and the characteristics when used as a hole transport layer material or the like are also good.

In the formula (1), the divalent group connecting two nitrogen atoms is a substituted or unsubstituted arylene, a substituted or unsubstituted heteroarylene, a substituted or unsubstituted alkylene, or a substituted or unsubstituted arylene. Alkenylene etc. are mentioned. In particular, groups represented by the following formulas are preferable.

That is, the structural unit represented by formula (1) is preferably represented by formula (1D) below.

D ring is a substituted or unsubstituted hydrocarbon ring or a substituted or unsubstituted hetero ring, two * represents the bonding position with two nitrogen atoms,

Ring D may be further bonded to ring A and/or ring C through a linking group or single bond.

It is preferable that ring D is a substituted or unsubstituted benzene ring or a substituted or unsubstituted cyclohexane ring. Each, specifically, the broken line indicates substituted or unsubstituted 1,2-phenylene or substituted or unsubstituted 1,2-cyclohexylene. A linking group in the case where ring D is further bonded to ring A and/or ring C via a linking group or single bond includes 1,2-phenylene.

Ring A forms a trivalent group having bonds with three consecutive elements (preferably carbon) on the ring of the aryl ring or heteroaryl ring in its structure. It binds to X ¹ , N and B, respectively, by these three binding hands. It is preferable that the aryl ring or heteroaryl ring in ring A is bonded to B, X ¹ and N by a 5- or 6-membered ring. Ring B forms a divalent group having bonds with two consecutive elements (preferably carbon) on the ring of the aryl ring or heteroaryl ring in its structure. It binds to X ¹ and B, respectively, by these two binding hands. The aryl ring or heteroaryl ring in the B ring is preferably bonded to B and X ¹ by a 5- or 6-membered ring. "Bonded in a 5- or 6-membered ring" means that a ring is formed only with this 5- or 6-membered ring, or that a ring is formed by further condensing other rings so as to include this 5- or 6-membered ring. In other words, it means that the 5- or 6-membered ring constituting all or part of the ring is bonded to B, X ¹ and N, or B and X ¹ . In the aryl ring or heteroaryl ring of the A ring and the B ring, two or three consecutive ring-constituting atoms (carbon atoms) may be directly bonded to B, X ¹ and N, or B and X ¹ . The C ring forms a divalent group having bonds with two consecutive elements (preferably carbon) on the hydrocarbon ring or heterocyclic ring in its structure. It bonds to N and C (carbon), respectively, by these two bonds. The D ring forms a divalent group having bonds with two consecutive elements (preferably carbon) in the hydrocarbon ring or heterocyclic ring in its structure. By these two binding hands, it binds to two N's. The hydrocarbon ring or heterocyclic ring in the C ring and the D ring is also preferably bonded to a carbon atom, a nitrogen atom, and two nitrogen atoms in a 5- or 6-membered ring, respectively.

The "hydrocarbon ring", "heterocycle", "aryl ring" or "heteroaryl ring" in the A ring, B ring, C ring, and D ring is at least one substituent selected from the substituent group Z described later. may be substituted with In addition, the "aryl ring" or "heteroaryl ring" in the A ring and the B ring may be bonded to X ¹ as described later.

<Structure containing the structural unit represented by Formula (1)>

The polycyclic aromatic compound of the present invention is a polycyclic aromatic compound having a structure including a structural unit represented by formula (1). The polycyclic aromatic compound having a structure containing the structural unit represented by formula (1) includes a polycyclic aromatic compound having a structure consisting of one or two or more structural units represented by formula (1). Examples of the polycyclic aromatic compound having a structure composed of one of the above structural units include polycyclic aromatic compounds represented by the formula described above as the structural unit represented by formula (1). Examples of the polycyclic aromatic compound having a structure composed of two or more structural units represented by formula (1) include compounds corresponding to multimers of the compounds represented by the above formula as structural units represented by formula (1). there is. As for a multimer, a 2-hexamer is preferable, a 2-3mer is more preferable, and a dimer is especially preferable. The multimer may be in the form of having a plurality of the above unit structures in one compound, and may be in the form of combining any rings (A rings, B rings or C rings) contained in the above structural units so as to share a plurality of unit structures. Further, any rings (rings A, B, or C) included in the unit structure may condense and bond to each other. Moreover, the form in which the said unit structure couple|bonded with multiple 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.

<Formula (1M), Formula (1-a), Formula (1-b), Formula (1-c), Formula (1-d), Formula (1-f), Formula (1-g), Formula ( 1-h) and equation (1-i)>

As the polycyclic aromatic compound having a structure containing the structural unit represented by formula (1), a compound represented by the following formula (1M) is further included.

In formula (1M), ring A and ring A' have the same meaning as ring A in formula (1), and their preferred ranges are also the same. The B ring and the B' ring have the same meaning as the B ring in formula (1), and the preferred ranges are also the same, but the B ring is aryl ring or heteroaryl ring in the structure. It forms a tetravalent group with a bonding hand. In formula (1M), X ¹ has the same meaning as X ¹ in formula (1), and the preferred range is also the same.

Preferable examples of the polycyclic aromatic compound having a structure containing the structural unit represented by formula (1) include the following formulas (1-a), formula (1-b), formula (1-c), and formula (1-d) , Formulas (1-f), Formulas (1-g), Formulas (1-h) and Formulas (1-i).

Formula (1-a), Formula (1-b), Formula (1-c), Formula (1-d), Formula (1-f), Formula (1-g), Formula (1-h) and Formula In (1-i),

Z is each independently N or CR ^Z , R ^Z is each independently hydrogen or any one substituent selected from substituent group Z,

Two adjacent ^RZs may be bonded to each other to form an aryl ring or heteroaryl ring, and the formed aryl ring or heteroaryl ring may each be substituted with any one substituent selected from substituent group Z,

Z=Z may each independently be >O, >NR, >C(-R) ₂ , >Si(-R) ₂ , >S, or >Se, wherein >NR and >C(-R) ₂ And R of >Si(-R) ₂ is each independently hydrogen, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted alkyl, or substituted or unsubstituted cycloalkyl, wherein Two Rs of >C(-R) ₂ and >Si(-R) ₂ above may be bonded to each other to form a ring.

Formula (1-a), Formula (1-b), Formula (1-c), Formula (1-d), Formula (1-f), Formula (1-g), Formula (1-h) to and In formula (1-i), it is preferable that all of Z are CR ^Z.

As any one substituent selected from substituent group ^Z which is RZ, it is preferable that it is alkyl, phenyl which may be substituted by alkyl, diphenylamino which may be substituted by alkyl, and carbazolyl which may be substituted by alkyl.

<Preferred partial structure>

A polycyclic aromatic compound having a structure including the structural unit represented by formula (1), particularly consisting of formula (1-a), formula (1-b), formula (1-c), and formula (1-d) The polycyclic aromatic compound represented by any one formula selected from the group is formula (B101), formula (B102), formula (B103), formula (B104), formula (B105), formula (B106), formula (B107) , and at least one partial structure represented by any one formula selected from the group consisting of formula (B108).

Among Formula (B101), Formula (B102), Formula (B103), Formula (B104), Formula (B105), Formula (B106), Formula (B107), and Formula (B108),

Z has the same meaning as Z in formulas (1-a), formulas (1-b), formulas (1-c), and formulas (1-d), and the preferred range is also the same. It is preferable that none of Z=Z is >O, etc., and that two adjacent ^RZs are not bonded to each other.

X ⁵ is >O, >NR, >C(-R) ₂ , >S, or >Se, wherein R of >NR is hydrogen, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted alkyl, substituted or unsubstituted cycloalkyl, wherein R in >C(-R) ₂ is each independently hydrogen, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted It is alkyl or substituted or unsubstituted cycloalkyl, and two R of >C(-R) ₂ may be bonded to each other to form a ring. X ⁵ is >O, >C(-CH ₃ ) ₂ , or >C(-R) ₂ where both R are phenyl, preferably two phenyls bonded to each other.

n is an integer of 1-3, 1 or 2 is preferable, and 2 is more preferable.

<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). 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 (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) , C1-C4 alkyl (C3-C4 branched chain alkyl).

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-dimethyl octyl, 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.

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 the substitution form of the group of formula (tR) in diarylamino, carbazolyl and benzocarbazolyl include examples in which part or all of the hydrogen of the aryl ring or benzene ring in this group is substituted with the group of 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 may be bonded to 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, in *, what is necessary is just to couple|bond with two or three consecutive (adjacent) atoms in the ring of any one of A ring, B ring, and C ring, or heteroaryl ring.

<Description of X ¹ >

X ¹ in Formula (1) is >O, >NR, >C(-R) ₂ , >Si(-R) ₂ , >S, or >Se, and R in >NR is hydrogen, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted alkyl, or substituted or unsubstituted cycloalkyl, wherein R in >C(-R) ₂ and >Si(-R) ₂ are each independently hydrogen, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted alkyl, or substituted or unsubstituted cycloalkyl, wherein >C(-R) ₂ and >Si The two Rs in (-R) ₂ may be bonded to each other to form a ring, and R in >NR, R in >C(-R) ₂ and >Si(-R) ₂ is a linking group or a single bond. may be bonded to the A ring and/or the B ring.

X ¹ in Formula (1) is more preferably >O or >NR, and more preferably >NR.

R in >Si(-R) ₂ and >C(-R) ₂ which is X ¹ is each independently hydrogen, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted alkyl, or substituted or unsubstituted cycloalkyl, preferably two R's are the same, and two R's may be bonded to each other to form a ring.

R of X ¹ >NR is preferably a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, or a substituted or unsubstituted cycloalkyl, and is a substituted or unsubstituted aryl or a substituted or unsubstituted heteroaryl is more preferable. Here, as aryl, phenyl, biphenylyl (especially 2-biphenylyl), and terphenylyl (especially terphenyl-2'-yl) are preferable, and as heteroaryl, benzothienyl (2-benzo thienyl, 6-benzothienyl, etc.), benzofuranyl (2-benzofuranyl, 3-benzofuranyl, 5-benzofuranyl, etc.), dibenzofuranyl (4-dibenzofuranyl, etc.), dimethyl Xanthenyl (2-dimethylxanthenyl etc.), dibenzodioxinyl, etc. are preferable. As the substituent, tertiary alkyl (particularly t-butyl) or cycloalkyl (particularly adamantyl) represented by the formula (tR) is preferable. As for the number of substituents in aryl and heteroaryl, 0-2 are preferable, 1 or 2 are more preferable, and 1 is still more preferable. It is also preferable when the aryl ring in the above aryl is condensed with a substituted or unsubstituted cycloalkane as described below. As specific cycloalkanes, reference can be made to those described later.

R in at least ^one of >NR, >Si(-R) ₂ and >C(-R) ₂ that is X 1 may be bonded to the A ring and/or the B ring through a linking group or a single bond. As the linking group, -O-, -S-, -C(-R ^F ) ₂ -, -Si(-R ^F ) ₂ -, -N=C(-R ^G )-, and -C(-R ^G ) =C(-R ^G )- is preferred. R ^F is hydrogen, alkyl, cycloalkyl, substituted or unsubstituted aryl, or substituted or unsubstituted heteroaryl, "-C(-R ^F ) ₂ -", "-Si(-R ^F ) ₂ -" Each of the two R ^F 's is preferably the same, and may be bonded to each other to form a ring. R ^G is hydrogen or a substituent. R ^G is preferably hydrogen, alkyl or phenyl which may be substituted with alkyl.

As an example in which R in X ¹ bonds to ring A and/or ring B, R is phenyl >NR forms a carbazole ring, phenoxazine ring, or phenothiazine ring as a partial structure together with the benzene ring in ring A or B When R is hydrogen (as a bond) >NR forms an indole ring or benzoimidazole ring as a partial structure together with the benzene ring in ring A or B, R is hydrogen (as a bond) A case where >NR forms an imidazoindole ring or triazoindole ring as a partial structure together with the indole ring in ring A or ring B is exemplified.

As another example, a form in which R in >N-R is a substituted or unsubstituted cycloalkyl and is bonded to the A ring or the B ring through a single bond is also preferable. As cycloalkyl, substituted or unsubstituted cyclopentyl or substituted or unsubstituted cyclohexyl is preferable.

A particularly preferable example of the condensed ring formed as described above is a structure represented by formula (A11). In formula (A11), * represents “R in at least one of X ¹ >NR, >Si(-R) ₂ and >C(-R) ₂ is ring A and/or B by a linking group or a single bond. In the above stipulation of "may be bonded to a ring", it corresponds to a form bonded by a single bond. In this case, the two carbons substituted by methyl are asymmetric carbons, and diastereomers and enantiomers may exist as the compound represented by formula (1), but isomers may be used as the compound represented by formula (1) , and may also be a form in which possible isomers are mixed in an arbitrary ratio.

In formula (A11), X ¹ is bonded to one ring of the two rings bonded at positions * and ** and to the other ring at position ***.

Similarly, the following examples in which R in the above >N-R is phenyl and is bonded to the A ring or the B ring by a single bond are exemplified.

In formula (A12), X ¹ is bonded to one ring of the two rings bonded at positions * and ** and to the other ring at position ***.

By using the compound of the present invention having >NR, which is R within the above preferred range as X ¹ , as a light emitting material for manufacturing a device, the luminous efficiency and lifetime of the device can be further improved.

Formula (1-a), Formula (1-b), Formula (1-c), Formula (1-d), Formula (1-f), Formula (1-g), Formula (1-h) and Formula In (1-i), X ² is each independently >O, >NR, >C(-R) ₂ , >S, or >Se, wherein R in >NR is hydrogen, substituted or unsubstituted Aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted alkyl, substituted or unsubstituted cycloalkyl, wherein >C(-R) ₂ R in 2 is each independently hydrogen, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted alkyl, or substituted or unsubstituted cycloalkyl, wherein >NR and >C(-R) ₂ are one of Z bonded to the same carbon atom, or Two or more may be bonded to R. X ² is more preferably >O or >NR, more preferably >NR. The preferable range of R is the same as the preferable range of R in >NR, which is X ¹ in Formula (1).

Formula (1-a), Formula (1-b), Formula (1-c), Formula (1-d), Formula (1-f), Formula (1-g), Formula (1-h) and Formula In (1-i), X ⁴ is >O, >NR, >C(-R) ₂ , >S, or >Se, wherein R in >NR is hydrogen, substituted or unsubstituted aryl, substituted or Unsubstituted heteroaryl, substituted or unsubstituted alkyl, substituted or unsubstituted cycloalkyl, wherein >C(-R) ₂ R in 2 is each independently hydrogen, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted alkyl, or substituted or unsubstituted cycloalkyl, wherein >NR and >C(-R) ₂ are one or two or more of Z bonded to the same carbon atom; may be bonded at R. X ⁴ is preferably >O, >NR, or >S.

<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 (1-a), Formula (1-b), Formula (1-c), Formula (1-d), Formula (1-f), Formula (1-g), Formula (1-h) and Formula 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 (1-i), and the following description also applies to polycyclic aromatic compounds represented by any one of these formulas. The same applies.

The cycloalkane may be a cycloalkane having 3 to 24 carbon atoms. 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. cycloalkane, cycloalkane having 5 to 6 carbon atoms, cycloalkane 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, for example, as shown in the following structural formula, at least in the carbon at the α position of the cycloalkane (the carbon at the position adjacent to the carbon at the condensation site in the cycloalkyl condensed with an aryl ring or a heteroaryl ring) A structure in which one hydrogen is substituted is preferable, a structure in which two hydrogens in the α-position carbon are substituted is more preferable, and a structure in which a total of 4 hydrogens in the two α-position carbons are substituted is even more preferable. desirable. 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. Examples of condensation of one benzene ring (phenyl) with one or more cycloalkanes are 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.

At least one hydrogen in the cycloalkane may be substituted, and as this substituent, for example, aryl, heteroaryl, diarylamino, diheteroarylamino, arylheteroarylamino, diarylboryl (two aryls are may be bonded through a single bond or a linking group), alkyl, cycloalkyl, alkoxy, aryloxy, substituted silyl, deuterium, cyano or halogen, details of which can be cited in the description of the first substituent described above. can Among these substituents, alkyl (eg, alkyl having 1 to 6 carbon atoms), cycloalkyl (eg, cycloalkyl having 3 to 14 carbon atoms), halogen (eg, fluorine), deuterium, and the like are preferable. In addition, when substituted by cycloalkyl, the substitution form which forms a spiro structure may be sufficient, and this example is shown below.

As the form of cycloalkane condensation, first, an aryl ring in each of the A ring, B ring, and C ring (and D ring) in a polycyclic aromatic compound having a structure containing the structural unit represented by Formula (1), and A form in which a heteroaryl ring is condensed with a cycloalkane is exemplified.

As another form of cycloalkane condensation, a polycyclic aromatic compound having a structure containing the structural unit represented by formula (1) is, for example, >N-R where R is aryl condensed with cycloalkane, dia condensed with cycloalkane Examples having lylamino (condensed to this aryl moiety), cycloalkane condensed carbazolyl (condensed to this benzene ring moiety) or cycloalkane condensed benzocarbazolyl (condensed to this benzene ring moiety) there is.

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 (1-a), Formula (1-b), Formula (1-c), Formula (1-d), Formula (1-f), Formula (1-g), Formula (1-h) and Formula 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 (1-i), and the following description is based on formulas (1-a) and (1-b) , any one selected from the group consisting of formula (1-c), formula (1-d), formula (1-f), formula (1-g), formula (1-h) and formula (1-i) 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), D ring (D ring is an aryl ring or hetero aryl ring) aryl ring), a substituent on A to C ring, and R when X ¹ is >NR, >C(-R) ₂ , or >Si(-R) ₂ (=alkyl, cycloalkyl, aryl, or Heteroaryl) may be substituted with deuterium, cyano or halogen, and among these, all or part of hydrogen in aryl or heteroaryl may be substituted with deuterium, cyano or halogen. . 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 having a structure containing a structural unit represented by formula (1)>

As a specific example of the polycyclic aromatic compound which has a structure containing the structural unit represented by Formula (1), the polycyclic aromatic compound represented by any one of the formulas below is mentioned. In the following formulas, at least one hydrogen may be substituted with alkyl, phenyl which may be substituted with alkyl, diphenylamino which may be substituted with alkyl, carbazolyl which may be substituted with alkyl, or deuterium.

Further specific examples of the polycyclic aromatic compound having a structure including the structural unit represented by Formula (1) include the following compounds. In addition, the polycyclic aromatic compound having a structure containing the structural unit represented by formula (1) is not limited to the following specific examples.

<Polycyclic aromatic compound having a structure containing a structural unit represented by formula (2)>

Among the polycyclic aromatic compounds having a structure including the structural unit represented by Formula (1), compounds suitable for use as a hole transport layer material in an organic EL device or a host material in a light emitting layer include A polycyclic aromatic compound having a structure including a structural unit represented by is exemplified. When a polycyclic aromatic compound having a structure including a structural unit represented by formula (2) is used as a host material, it is preferably used as a hole-transporting host material.

In formula (2), Z has the same meaning as Z in formula (1-a), etc., but in formula (2), in the group consisting of substituents of rings formed by bonding R ^Z and adjacent R ^Zs , At least one selected is a group represented by a formula selected from the group consisting of formula (A-1), formula (A-2) and formula (A-3). Amorphous stability is imparted by a group represented by a formula selected from the group consisting of formula (A-1), formula (A-2) and formula (A-3). In addition, carrier transport properties can be adjusted by a group represented by a formula selected from the group consisting of formula (A-1), formula (A-2) and formula (A-3).

In formula (2), as a substituent of a ring formed by bonding R ^Z or adjacent R ^Zs , it is selected from the group consisting of formula (A-1), formula (A-2) and formula (A-3) It is also preferable not to contain substituents other than the group represented by the formula.

A group represented by a formula in which at least one of R ^Z is selected from the group consisting of formula (A-1), formula (A-2) and formula (A-3), when there is no ring formed by bonding R ^Z to each other am. When there is a ring formed by bonding R ^Z to each other, at least one selected from the group consisting of groups substituting hydrogen in the ring formed by bonding R ^Z and adjacent R ^Z bonds to Formula (A-1); It is a group represented by a formula selected from the group consisting of formula (A-2) and formula (A-3).

The number of groups (in CR ^Z In the group consisting of formula (A-1), formula (A-2) and formula (A-3) directly bonded to ^C of The number of groups represented by the selected formula) is preferably 1 to 4, more preferably 1 or 2.

In formula (A-1),

W ¹ and W ² are each independently a single bond, >C(-R ^W ) ₂ , >O, >NR ^W , >Si(-R ^W ) ₂ , >S, >SO or >SO ₂ , R ^W of >NR ^W is any substituent selected from substituent group Z, a group represented by formula (A-2) or a group represented by formula (A-3), and the >C(-R ^W ) ₂ , >Si(-R ^W ) ₂ R ^W are each independently hydrogen, any one substituent selected from substituent group Z, a group represented by formula (A-2), or formula (A-3) It is the flag that is displayed. R ^W bonding to the same element may be bonded to each other, and R W of >NR ^W , >C(-R ^W ) ₂ , and ^> Si(-R ^W ) ₂ are each independently bonded to at least one Y, may be

Y is N or CR ^Y , R ^Y is each independently hydrogen, any substituent selected from substituent group Z, a group represented by formula (A-2) or a group represented by formula (A-3) . R ^Y in adjacent Y may be mutually bonded to form an aryl ring or heteroaryl ring. In addition, the formed ring may have any one substituent selected from substituent group Z, the group represented by formula (A-2), or the group represented by formula (A-3).

L ¹ is a single bond or a linking group.

L ¹ is bonded to C of any one of CR ^Y with R ^Y as a bond hand, or >C(-R ^{W )} ₂ of C, >NR ^W of N, >O, with R W as a bond hand It is bonded to Si of >Si(-R ^W ) ₂ , or bonded to a ring constituting atom of a ring formed by bonding R ^Y in Y to each other.

* represents the bonding position of the group represented by Formula (A-1).

In formula (A-2),

Y is N or CR ^Y , and R ^Y is each independently hydrogen, any substituent selected from substituent group Z, a group represented by formula (A-1) or a group represented by formula (A-3) . R ^Y in adjacent Y may be mutually bonded to form an aryl ring or heteroaryl ring. In addition, the formed ring may have any one substituent selected from substituent group Z, the group represented by formula (A-1), or the group represented by formula (A-3).

L ² is a single bond or a linking group.

L ² is bonded to C of any one of CRY ^{with R Y as} a bond hand, or bonded to a ring-constituting atom of a ring formed by bonding R ^Y in Y to each other.

* represents the bonding position of the group represented by Formula (A-2).

In formula (A-3),

Ar ³ is each independently selected from at least one substituent selected from substituent group Z, aryl optionally substituted with a group represented by formula (A-1) or formula (A-2), and at least one selected from substituent group Z It is a heteroaryl which may be substituted with a substituent or a group represented by formula (A-1) or formula (A-2), or a group represented by formula (A-1) or formula (A-2).

W ³ is Si, P or S, and when W ³ is Si, m is 3 and n is 0. When W 3 is P, m is 2 and n is 0 or 1, and when W ³ is S, ^m is 2 and n is 0 or 1. m is 1, and n is an integer of 0 to 2;

L ³ is a single bond or a linking group.

* represents the bonding position of the group represented by Formula (A-3).

In Formula (A-1) or Formula (A-2), L ¹ , L ² and L ³ are each independently a single bond, or arylene, heteroarylene, >NR ^L , >O , >C(-R ^L ) ₂ , >Si(-R ^L ) ₂ , >S, >Se, and a linking group selected from the group consisting of a combination of two or more of these. L ¹ , L ² and L ³ are each independently a single bond, arylene which may be substituted with aryl or heteroaryl, heteroarylene which may be substituted with aryl or heteroaryl, >NR ^L , >O; It is more preferably a linking group selected from the group consisting of >C(-R ^L ) ₂ , >Si(-R ^L ) ₂ , >S, >Se, and a group consisting of a combination of two or more of these.

R L in > ^{NR L} , >C(-R ^L ) ₂ and >Si(-R ^L ) ₂ in L ¹ , L ² and L ³ is each independently selected from hydrogen and substituent group Z. It is one substituent or a group represented by formula (A-3), and R ^L bonded to the same element may be mutually bonded.

As R ^L in >NR ^L in L ¹ , L ² and L ³ , aryl which may be substituted with aryl or heteroaryl, or heteroaryl which may be substituted with aryl or heteroaryl is preferable. R ^L in >C(-R ^L ) ₂ in L ¹ , L ² and L ³ is preferably all alkyl, and two R ^Ls , all of which are alkyl, combine to form a cycloalkane such as cyclohexane, It is desirable to have It is preferable that all of R ^L in >Si(-R ^L ) ₂ in L ¹ , L ² and L ³ are methyl.

L ¹ , L ² and L ³ are preferably single bonds, arylene which may be substituted with aryl or heteroaryl, heteroarylene which may be substituted with aryl or heteroaryl, or substituted with aryl or heteroaryl. A linking group formed by linking two or more selected from optionally arylene and heteroarylene which may be substituted with aryl or heteroaryl;

More preferably, arylene which may be substituted with aryl or heteroaryl, heteroarylene which may be substituted with aryl or heteroaryl, or arylene which may be substituted with aryl or heteroaryl and substituted with aryl or heteroaryl It is a linking group constituted by linking two or more selected from heteroarylene which may be used.

The arylene which may be substituted with aryl or heteroaryl in L ¹ , L ² and L ³ and the heteroarylene which may be substituted with aryl or heteroaryl preferably have a bonding site so as to form a cross-conjugate. For example, phenylene is preferably 1,3-phenylene.

Examples of the linking groups of L ¹ , L ² and L ³ include linking groups represented by the following formulas. In the formulas below, * represents a bonding position, and in either *, C in CR ^Z or R ^Z in Z is bonded to a ring-constituting atom of a ring formed by bonding to each other, and in the other formula (A- It is assumed that it is bonded to a partial structure other than L ¹ in 1), a partial structure other than L ² in formula (A-2), or a partial structure other than L ³ in formula (A-3).

In the group represented by formula (A-1), when W ¹ or W ² is >NR ^W , R ^W is preferably a substituted or unsubstituted aryl or a substituted or unsubstituted heteroaryl. It is also preferable that -R ^W of >NR ^W is bonded to L ¹ as a bonding hand.

In the group represented by formula (A-1), when W ¹ or W ² is >C(-R ^W ) ₂ , R ^W is all substituted or unsubstituted aryl, or all are substituted or unsubstituted hetero It is preferably aryl. It is also excellent in compound stability that two R ^W are bonded by a single bond, and is preferable. It is more preferable that both R ^W are phenyl, and that these phenyls are bonded to each other through a single bond.

In the group represented by formula (A-1), when W ¹ or W ² is >Si(-R ^W ) ₂ , R ^W is all substituted or unsubstituted aryl, or all are substituted or unsubstituted hetero It is preferably aryl. It is also excellent in compound stability that two R ^W are bonded by a single bond, and is preferable. It is more preferable that both R ^W are phenyl, and that these phenyls are bonded to each other through a single bond.

In the group represented by formula (A-1), W ¹ is >NR ^W , >C(-R ^W ) ₂ , >O, >Si(-R ^W ) ₂ or >S, and W ² is a single bond It is desirable to be It is because it is excellent in compound stability and carrier transportability. More preferably, W ¹ is >NR ^W , >O, or >S, and W ² is a single bond, and even more preferably, W ¹ is NR ^W , and W ² is a single bond. At this time, R ^W is particularly preferably a bond with L ¹ .

R W of >NR ^W , >C(-R ^W ) ₂ , and >Si(-R ^{W )} ₂ of W ¹ or W ² may be each independently bonded to at least one Y. Examples of structures in which >NR ^W of W ¹ or W ² is bonded to Y include the following structures.

In the group represented by formula (A-1), it is preferable that 0 to 2 Ys are N and the other is CR ^Y , more preferably 0 to 1 Y is N and the other is CR ^Y , and all Even more preferably, Y is CR ^Y . R ^Y are each independently hydrogen, aryl or heteroaryl optionally substituted aryl, aryl or heteroaryl optionally substituted heteroaryl, aryl or heteroaryl optionally substituted diheteroarylamino, aryl or heteroaryl It is preferably an arylheteroarylamino which may be substituted with . This is because carrier transportability is good. Aryl or heteroaryl as a substituent may be further substituted with aryl or heteroaryl. In the group represented by formula (A-1), it is preferable that R ^Y is 0 to 3 as for C R ^Y other than hydrogen. This is because the amorphous stability is good. As for CRY where R ^<Y> is other than hydrogen, it is more preferable that it is 0-2, and ^it is still more preferable that it is 0-1. As R ^Y other than hydrogen in the group represented by formula (A-1), N-carbazolyl, a group represented by formula (A-2), or a group represented by formula (A-3) is preferable.

In the group represented by formula (A-1), two R ^Y 's in Y that are adjacent C R ^Y may be bonded to each other to form an aryl ring or a heteroaryl ring. As an example of the group represented by the formula (A-1) formed with an aryl ring or a heteroaryl ring in this way, groups represented by any of the following formulas can be given.

In the formula, * represents a binding position.

In addition, the formed ring may have a substituent. The number of substituents is preferably 0 to 2, and more preferably 0 to 1. The substituent is aryl which may be substituted with aryl or heteroaryl, heteroaryl which may be substituted with aryl or heteroaryl, diheteroarylamino which may be substituted with aryl or heteroaryl, aryl which may be substituted with aryl or heteroaryl. Heteroarylamino is preferred.

L ¹ is bonded to C of any one of CR ^Y with R ^Y as a bond hand, or >C(-R ^{W )} ₂ of C, >NR ^W of N, >O, > with R W as a bond hand. It is bonded to Si of Si(-R ^W ) ₂ or bonded directly to a ring constituting atom of a ring formed by bonding R ^Y in Y to each other.

In the group represented by formula (A-1), it is preferable to be bonded to L ¹ in W ¹ that is not a single bond. In particular, it is preferable that N and L ¹ of >NR ^W are bonded.

In the group represented by formula (A-2), it is preferable that 0 to 3 Ys are N and others are CR ^Y , and it is more preferable that 1 to 3 Ys are N and the others are CR ^Y . It is preferable that a plurality of N's are not adjacent to each other. Specifically, the group represented by formula (A-2) is 5 Y and N, and forms a pyridine ring, pyrimidine ring, pyrazine ring, or triazine ring, or R ^Y substituted at adjacent carbons in these rings. are bonded to each other to form an aryl ring or a heteroaryl ring, and is preferably a quinoline ring, isoquinoline ring, quinoxaline ring, quinazoline ring, or purine ring. R ^Y are each independently hydrogen, aryl or heteroaryl optionally substituted aryl, aryl or heteroaryl optionally substituted heteroaryl, aryl or heteroaryl optionally substituted diheteroarylamino, aryl or heteroaryl It is preferably an arylheteroarylamino which may be substituted with . This is because carrier transportability is good. The same applies to the substituent when R ^Y of adjacent Y is bonded to each other to form an aryl ring or heteroaryl ring. Aryl or heteroaryl as a substituent may be further substituted with aryl or heteroaryl. In the group represented by formula (A-2), it is preferable that R ^Y is 0 to 3 as for C R ^Y other than hydrogen. This is because the amorphous stability is good. As for CRY where R ^<Y> is other than hydrogen, it is more preferable that it is 0-2, and ^it is still more preferable that it is 0-1.

In the group represented by formula (A-3), Ar ³ is each independently substituted with aryl or heteroaryl (excluding the group represented by formula (A-1)), aryl or heteroaryl which may be substituted with Heteroaryl (excluding the group represented by formula (A-1)) which may be present, or a group represented by formula (A-1) is preferred, and unsubstituted aryl, unsubstituted heteroaryl or formula (A-1) A group represented by is preferred.

In the group represented by formula (A-3), a larger m is preferred because it has excellent electron transport properties.

In the group represented by formula (A-3), it is preferable that W ³ is Si because of excellent compound stability.

In the group represented by formula (A-3), it is most preferable that W ³ is Si, m is 3, and n is 0.

<Specific examples of polycyclic aromatic compounds having a structure containing a structural unit represented by formula (2)>

Further specific examples of the polycyclic aromatic compound having a structure including the structural unit represented by formula (2) include the following compounds. In addition, the polycyclic aromatic compound having a structure containing the structural unit represented by formula (2) is not limited to the following specific examples.

<Method for producing polycyclic aromatic compound>

The polycyclic aromatic compound represented by formula (1) or formula (2) and its multimer are basically condensed first comprising ring A (ring a), ring B (ring b), and ring C (ring c). An intermediate is prepared by linking the rings with a linking group (group containing X ¹ ) and a single bond (first reaction), and thereafter, ring A (ring a), ring B (ring b) and ring C (ring c) A final product can be prepared by bonding a condensed ring containing 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 can be used. In addition, in the second reaction, a tandem hetero Friedel Crafts reaction (continuous aromatic electron transfer reaction, hereinafter the same) can be used.

In the second reaction, as shown in the scheme (1) or (2) below, boron is introduced into a condensed ring comprising ring A (ring a), ring B (ring b) and ring C (ring c). is a reaction First, a halogen atom between X ¹ and a nitrogen atom is halogen-metal exchanged with n-butyllithium, sec-butyllithium, t-butyllithium, or the like. 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 addition, although the said scheme (1) and (2) mainly show the manufacturing method of the polycyclic aromatic compound represented by Formula (1) and (2), about the multimer, a plurality of ring A (a ring), It can be produced by using an intermediate having a B ring (b ring) and a C ring (c ring).

By appropriately selecting the raw material to be used, a polycyclic aromatic compound having a substituent at a desired position and a multimer thereof 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 above schemes (1) and (2), 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, thereby tandem hetero Friedel Kraff An example of the reaction is presented, but the reaction can also be carried out by adding boron trichloride or boron tribromide to a precursor in which halogen is hydrogen.

In addition, as the orthometallization reagent used in the above schemes (1) and (2), alkyl lithium such as methyl lithium, n-butyl lithium, sec-butyl lithium and t-butyl lithium, lithium diisopropylamide, lithium tetra and organic alkali compounds such as methylpiperidide, lithium hexamethyldisilazide, and potassium hexamethyldisilazide.

In addition, as the metal-boron metal exchange reagent used in the above schemes (1) and (2), boron halides such as boron trifluoride, boron trichloride, boron tribromide and boron triiodide, boron alkoxides, and boron aryl oxides of

In addition, as the Bronsted base used in the schemes (1) and (2), 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, tetra Phenylsilane, Ar ₄ BNa, Ar ₄ BK, Ar ₃ B, Ar ₄ Si (Ar is aryl such as phenyl), and the like.

Examples of Lewis acids used in schemes (1) and (2) include AlCl ₃ , AlBr ₃ , AlF ₃ , BF ₃ OEt ₂ , BCl ₃ , BBr 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 ,} etc. can

In the above schemes (1) and (2), 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, hydrogen fluoride, hydrogen chloride, hydrogen bromide, and hydrogen iodide Since acid is produced, the use of a Bronsted base to capture the acid 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 proceeds, so in most cases it is not necessary to use a Bronsted base. , Since the ability to release amino or alkoxy is low, the use of a Lewis acid that promotes the release is effective.

In addition, a polycyclic aromatic compound having a structure including a structural unit represented by formula (2) is obtained by synthesizing a compound represented by formula (1-b) containing a reactive substituent such as a halogen according to the above scheme, and It can also be synthesized by cross-coupling with a substituent. For the cross-coupling, general reactions such as Ullmann reaction, Buckwald Hartwick reaction, and Suzuki Miura reaction can be used.

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.

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.

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 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 . Meanwhile, 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 or two (two types) or more 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 a material for the hole transport layer, it is also preferable to use a polycyclic aromatic compound having a structure including a structural unit represented by formula (2).

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, N4,N4'-diphenyl-N4,N4'-bis(9-phenyl-9H-carbazol-3-yl)-[1,1'-biphenyl]-4 ,4'-diamine, N4,N4,N4',N4'-tetra[1,1'-biphenyl]-4-yl)-[1,1'-biphenyl]-4,4'-diamine, 4 Triphenylamine derivatives such as ,4',4"-tris(3-methylphenyl(phenyl)amino)triphenylamine, starburstamine derivatives, etc.), stilbene derivatives, phthalocyanine derivatives (metal-free, copper phthalocyanine, etc.), pyra sleepy derivatives, hydrazone-based compounds, benzofuran derivatives or thiophene derivatives, oxadiazole derivatives, quinoxaline derivatives (e.g., 1,4,5,8,9,12-hexaazatriphenylene-2,3, 6,7,10,11-hexacarbonitrile, etc.), heterocyclic compounds such as porphyrin derivatives, polysilanes, etc. In the polymer system, polycarbonates having the above monomers in their side chains, styrene derivatives, polyvinylcarbazole, and polysilanes Although the like are preferable, it is not particularly limited as long as it is a compound capable of forming a thin film required for fabrication of a light emitting element, 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 substituted with a reactive substituent 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 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, and is more preferably used as a material for forming a light emitting layer.

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 polycyclic aromatic compound of the present invention can be used as a material for a light emitting layer, may be used as a dopant material, or may be used as a host material, but is preferably used as a dopant material. However, it is preferable to use a polycyclic aromatic compound having a structure containing a structural unit represented by formula (2) as a host material.

A polycyclic aromatic compound or the like having a structure including a structural unit represented by Formula (1) can exhibit thermally activated delayed fluorescence (TADF) as a "thermally activated delayed fluorescent substance". 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. Migration occurs with high efficiency, and light emission from singlets (thermally 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.

The polycyclic aromatic compound having a structure including the structural unit represented by Formula (1) is an emitting dopant, a hole-transporting host material, and an electron-emitting dopant of a TADF element using one type of host material in the organic electroluminescent element of the present invention. Emitter dopant of TADF device using transportable host material, organic electroluminescent device (TADF-assisted fluorescent device, TAF device) using separate thermally activated delayed phosphor as assisting dopant , or an organic electroluminescent device (phosphor-sensitized fluorescent device, PSF device) using a phosphorescent material as an assisting dopant.

The light emitting layer may be either a single layer or a plurality of layers, and each is formed of a light emitting layer material (host material, dopant material). The host material and the dopant material may 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 amounts of the host material, the assisting dopant material and the 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 %.

<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-phenylcarbazole derivatives, carbazonitrile derivatives, etc. are mentioned.

The lowest triplet excitation energy level of the host material is the lowest excitation triplet of the dopant or assisting dopant having the highest lowest triplet excitation energy level in the light emitting layer from the viewpoint of promoting the generation of TADF in the light emitting layer without inhibiting it. It is preferably higher than the energy level, and specifically, the triplet energy of the host material is preferably 0.01 eV or more, more preferably 0.03 eV or more, and even more preferably 0.1 eV or more. Further, a compound having TADF activity 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.

A polycyclic aromatic compound having a structure including a structural unit represented by Formula (2) can also be used as a host material.

[Anthracene derivatives]

As an anthracene derivative, the description of paragraph 0124 to 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 group selected from substituent group Z, and all X and Ar ⁴ are never 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, there is no case where two X's simultaneously become a group represented by formula (3-X3). More preferably, two X's do not simultaneously become groups represented by formula (3-X2).

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 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, p Relyl 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, pyrellyl, 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 selected from alkyl having 1 to 4 carbon atoms, cycloalkyl having 5 to 10 carbon atoms, phenyl, biphenylyl, terphenylyl, naphthyl, and phenane. It may further be substituted with a group represented by toryl, fluorenyl, chrysenyl, triphenylenyl, pyrellyl, or formula (A) (including carbazolyl and phenyl-substituted carbazolyl). 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 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-.

[Hole-transporting host material and electron-transporting host material]

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 that of the E T1 , and specifically, the E _T1 of the host material is 0.01 eV or more compared to the E _T1 of the above-mentioned emitting dopant or assisting dopant. 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.

[Hole-transporting host material (HH)]

Examples of preferable hole-transporting host materials (HH) include compounds represented by formula (HH-1) and formula (HH-1) in addition to the polycyclic aromatic compound of the present invention having a structure containing the structural unit represented by formula (2). ), and a compound having a structure containing at least three rings selected from the group consisting of an aryl ring and a heteroaryl ring. It is preferable that this compound contains neither an imine structure (-N=C-; partial structure of a heteroaryl ring), boron (>B-), nor cyano (CN).

In formula (HH-1),

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

One carbon atom next to the carbon atom to which Q is bonded 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 above 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 . 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 and HH-1-106 to HH-1-114 are preferable.

[Electron transport host material (EH)]

As an example of the electron transporting host material (EH),

At least one selected from the group consisting of an aryl ring and a heteroaryl ring having a partial structure represented by formulas (EH-1A) to (EH-1D) or formulas (EH-1A) to (EH-1D); Compounds having a structure containing three rings are exemplified.

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 above 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 preferable 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) Polymers 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 ² together does not result in >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.

Adjacent groups among R ¹ , R ² , R ³ , R ⁴ and R ⁵ , and R in =C(-R)- as Y ¹ to ^{Y 6} are bonded 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 (1) may be substituted with cyano, halogen or deuterium.

In 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 at least one selected from the group consisting of substituents other than hydrogen, and the other being 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 and Y ⁶ are =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- (ring b and c are pyridine rings), Y ² to ^{Y 5} are =N- (ring 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 arrangement relationship of =N- above, it is preferable that X ¹ and X ² 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 a high E _S1 , a high E _T1 , and a small ΔES _1T1 compared to 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 to 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 triplet excitation energy 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 0.20eV or more shallow than (EH), LUMO(HH) is 0.20eV or more deeper than HOMO(EH) is more preferable, HOMO(HH) is 0.25eV or more shallower than HOMO(EH), and LUMO(HH) is HOMO 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 excitation triplet energy, in the hole-transporting host material, carbazole, dibenzofuran, dibenzothiophene, triarylamine, indolocarbazole and benzoxazinophenoxazine A compound having as a partial 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, for the electron transporting host material, compounds having pyridine, triazine, phosphine oxide, benzofuropyridine and dibenzooxacillin as partial structures are preferred, and triazine, phosphine oxide, benzofuropyridine and dibenzofuropyridine A compound having benzoxacillin 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 and HH-1-106 to HH-1-114 It is preferably selected from the group consisting of, 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-1-127 to EH-1-130 It is preferable to be selected from the group. Preferred examples of combinations include compound HH-1-1 and compound EH-1-22, compound HH-1-1 and compound EH-1-23, compound HH-1-1 and compound EH-1-24, compound HH- 1-2 and compound EH-1-22, compound HH-1-2 and compound EH-1-23, compound HH-1-2 and compound EH-1-24, or compound HH-1-1 and compound EH- 1-128 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 properties of HOMO, LUMO and excitation triplet energy, compounds having carbazole, triarylamine, indolocarbazole and benzoxazinophenoxazine as partial structures are preferred for the hole-transporting host material, , compounds having triarylamine, 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. A compound having as a structure is more preferable, and a compound having a phosphine oxide and a triazine is even more preferable.

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 may be referred to.

<Dopant material>

It is preferable to use the polycyclic aromatic compound of this invention which has a structure containing the structural unit represented by Formula (1) as a dopant material. In addition, as a dopant material that can be used, a known compound can be used, and it 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. The polycyclic aromatic compound having a boron atom may be a phosphor or a TADF material (heat activated delayed phosphor). The polycyclic aromatic compound having a boron atom is preferably a blue light emitting compound.

Preferred examples of the boron-containing polycyclic aromatic compound include compounds represented by the following formula (12), formula (13) or formula (14).

A ring, B ring, C ring, and D ring are each independently a substituted or unsubstituted aryl ring or a substituted or unsubstituted heteroaryl ring;

Y is B (boron);

X ¹ , X ² , X ³ and X ⁴ are each independently >O, >NR, >S or >Se, wherein R of >NR is substituted or unsubstituted aryl, substituted or unsubstituted hetero aryl or substituted or unsubstituted alkyl, and R in >NR may be bonded to the A ring, B ring, C ring and/or D ring by a linking group or a single bond;

R ¹ and R ² are each independently hydrogen, alkyl having 1 to 6 carbon atoms, aryl having 6 to 12 carbon atoms, heteroaryl having 2 to 15 carbon atoms, or diarylamino (wherein aryl is aryl having 6 to 12 carbon atoms); ,

Z ¹ and Z ² are each independently any one substituent selected from substituent group Z, Z ¹ may bond to the A ring through a linking group or single bond, and Z ² bonds to the C ring through a linking group or single bond. You can do it, and

At least one hydrogen in the compound represented by formula (12) may be substituted with cyano, halogen or deuterium.

In the A ring, B ring, C ring and D ring of formula (12), as the substituent when the aryl ring or heteroaryl ring is substituted, and Z ¹ , Z ² , a substituent selected from substituent group Z is exemplified. there is.

X ¹ , X ² , X ³ and X ⁴ in formula (12) are each independently >O, >NR, >S or >Se, and R in >NR is each independently 6 carbon atoms It is aryl of -12, heteroaryl of 2-15 carbon atoms, cycloalkyl of 3-12 carbon atoms, or alkyl of 1-6 carbon atoms.

In the compound represented by formula (12), from the viewpoint of high TADF property, it is preferable that Z ¹ and Z ² are diphenylamino which may have a substituent or N-carbazolyl which may have a substituent, and has a substituent It is more preferable that it is also diphenylamino. As diphenylamino which may have a substituent, unsubstituted diphenylamino or diphenylamino having at least one alkyl of 1 to 4 carbon atoms is preferable, and unsubstituted diphenylamino or m-position or o relative to N Diphenylamino having at least one methyl at the position is more preferred. From the viewpoint of ease of synthesis and emission wavelength, the aryl ring or heteroaryl ring in the A ring, B ring, C ring and D ring does not have a substituent other than Z ¹ and Z ² , or contains only alkyl having 1 to 6 carbon atoms. It is preferable to have as an external substituent, and it is more preferable to have no substituent other than Z ¹ and Z ² .

The example of the compound represented by Formula (12) is shown below.

In formulas (13) and (14),

A ¹¹ ring, A ²¹ ring, A ³¹ ring, B ¹¹ ring, B ²¹ ring, C ¹¹ ring, and C ³¹ ring are each independently a substituted or unsubstituted aryl ring or a substituted or unsubstituted heteroaryl ring. ,

Y ¹¹ , Y ²¹ , Y ³¹ are B (boron);

X ¹¹ , X ¹² , X ²¹ , X ²² , X ³¹ , and X ³² are each independently >O, >NR, >S, or >Se, wherein R in >NR is substituted or unsubstituted aryl , substituted or unsubstituted heteroaryl or substituted or unsubstituted alkyl, and R in >NR is A ¹¹ ring, A ²¹ ring, A ³¹ ring, B ¹¹ ring, B ²¹ ring by a linking group or a single bond. , may be bonded to the C ¹¹ ring, and/or the C ³¹ ring;

At least one hydrogen in the compounds represented by formulas (13) and (14) may be substituted with cyano, halogen or deuterium.

The aryl ring or heteroaryl ring in the A ¹¹ ring, the A ²¹ ring, the A ³¹ ring, the B ¹¹ ring, the B ²¹ ring, the C ¹¹ ring, and the C ³¹ ring in Formulas (13) and (14) is substituted. As the substituent and Z ¹ , Z ² when present, a substituent selected from the substituent group Z is exemplified.

X ¹¹ , X ¹² , X ²¹ , X ²² , X ³¹ , and X ³² in Formulas (13) and (14) are each independently >O, >NR, >S, or >Se, and the above R in >NR is each independently an aryl having 6 to 12 carbon atoms, a heteroaryl having 2 to 15 carbon atoms, a cycloalkyl having 3 to 12 carbon atoms, or an alkyl having 1 to 6 carbon atoms.

Examples of compounds represented by formula (13) or formula (14) are shown below.

<Heat activated delayed phosphor (assisting dopant)>

"Thermally activated delayed phosphor" is a phosphor capable of absorbing thermal energy to cause inverse intersystem crossing from the lowest triplet excited state to the lowest singlet excited state, and radiatively deactivated from the lowest singlet excited state to emit delayed fluorescence. means compound. However, "heat-activated delayed fluorescence" includes those that pass through higher-order triplet 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. :e1603282), a paper by Kyoto University scholars (Scientific Reports, 7:4820, DOI:10.1038/s41598-017-05007-7), and a conference presentation by Kyoto University scholars (Japan Chemical Society 98th Spring Banquet) , Publication No.: 2I4-15, Mechanism of High Efficiency Luminescence in Organic Electroluminescence Using DABNA as a Light-Emitting Molecule, Graduate School of Engineering, Kyoto University), and the like. 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.).

The polycyclic aromatic compound of the present invention having a structure including the structural unit represented by formula (1) can function as an emitting dopant, and the “heat-activated delayed phosphor” suppresses light emission from the polycyclic aromatic compound of the present invention. It can function as an assisting dopant to assist.

In the following description, 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 "host compound" in the TAF element means that the 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 the second component and the emitting dopant as the third component. high compound.

2 shows an energy level diagram of the light emitting layer of a TAF device using a general fluorescent dopant as an emitting dopant (ED). In the figure, the energy level of the ground state of the host is E(1, G), the lowest excitation singlet energy level obtained from the shoulder on the short wavelength side of the fluorescence spectrum of the host is E(1, S, Sh), and the short wavelength of the phosphorescence spectrum of the host is The lowest excitation triplet energy level obtained from the side shoulder is E(1, T, Sh), the assisting dopant's ground state energy level is E(2, G), and the assisting dopant's fluorescence spectrum is obtained from the short wavelength side's shoulder E(2, S, Sh) for the lowest excitation singlet energy level, E(2, T, Sh) for the lowest excitation triplet energy level obtained from the shoulder on the short wavelength side of the phosphorescence spectrum of the assisting dopant, The ground state energy level is E(3, G), the lowest excitation singlet energy level obtained from the shoulder on the short wavelength side of the fluorescence spectrum of the emitting dopant is E(3, S, Sh), and the phosphorescence spectrum of the emitting dopant. The lowest excitation triplet energy level obtained from the shoulder 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 of the lowest excitation triplet energy 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 the lowest excitation on the emitting dopant. An intersystem crossing occurs from the singlet energy level E(3, S, Sh) to the lowest excitation triplet energy level E(3, T, Sh), and then thermally to the ground state E(3, G). to be deactivated 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 It is 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.

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.

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. The one 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 is preferable, and specifically As, the lowest excitation triplet energy level E(1, T, Sh) of the host compound is preferably 0.01 eV or more, and is 0.03 eV, compared to E(2, T, Sh), E(3, T, Sh). Above is more preferable, and 0.1eV or more is even more preferable. Further, a compound having TADF activity may be used as the host compound.

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, a small exchange interaction between HOMO and LUMO and a small ΔEST, so it is very Fast inverse interterm 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, high color purity can be provided by using a thermally activated delayed phosphor using a donor or acceptor as an assisting dopant together with an appropriate emitting dopant such as a polycyclic aromatic compound of the present invention.

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-dihydroinde Noacridine, diphenyldihydrodibenzoazacillin, etc. are mentioned. As the acceptor structure, sulfonyldibenzene, benzophenone, phenylenebis (phenylmethanone), benzonitrile, isonicotinonitrile, phthalonitrile, isophthalonitrile, paraphthalonitrile, benzenetricarbonitrile, triazole , oxazole, thiadiazole, benzothiazole, benzobis(thiazole), benzoxazole, 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 (assisting dopant)>

In the light emitting layer, you may use a phosphorescent material as an assisting dopant. Phosphorescent materials utilize intramolecular spin-orbit interactions (heavy atom effect) by metal atoms to obtain light emission from triplets. 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(PF6), 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 a formula (B-1), the compound represented by any one of the following formulas is 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 Application 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 one kind selected from metal complexes having 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, arylnitrile derivatives, and indole derivatives. Examples of the electron-accepting nitrogen-containing metal complex include hydroxyazole complexes such as hydroxyphenyloxazole complexes, azomethine complexes, tropolone metal complexes, flavonol metal complexes, and benzoquinoline metal complexes. Although these materials are used alone, you may mix and use them 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, diphenylquinone 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)phenyl phosphine 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.

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). to 2.5 eV) or Ba (copper 2.52 eV), etc., and materials with a work function of 2.9 eV or less are 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- an indium alloy, an aluminum-lithium alloy such as lithium fluoride/aluminum, etc.) and the like are preferable. 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 materials 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 to +400 ° C, vacuum degree 10 ^-6 to ^{10 -3} Pa, deposition rate 0.01 to 50 nm / sec, substrate temperature -150 to +300 ° C, film thickness 2 nm to 5 μm. 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 spin coat method uses a spin coater, the slit coat method uses a slit coater, and the gravure offset, reverse offset, flexographic printing, and inkjet printers are used for the plate method. The method of doing this 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 sequence, an organic EL device composed of anode/hole injection layer/hole transport layer/light emitting layer composed of host material and dopant material/electron transport layer/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 in the opposite order 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.

<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 that dissolves the first and second components in the composition, and upon application, imparts a smooth and uniform surface shape 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, it is possible to control and improve the film formability and the presence or absence of defects, surface roughness, and smoothness of the coating film. 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.

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 multiple times at different temperatures, or a plurality of drying methods may be used in combination.

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-type solvent etc. are mentioned, but it is not limited to this. 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.

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

The content of each component in the composition for forming an organic layer is determined based on 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.

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 substitution/encapsulation treatment may be appropriately selected and performed.

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.

[Example]

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

<Synthesis of compounds>

Synthesis Example (1-1):

Synthesis of compound (1-1)

1st process

Under nitrogen atmosphere, compound (T-1) (5.3 g), compound (T-2) (3.9 g) (synthesized according to the method described in International Publication No. 2019/114611), tert-butoxysodium (2.9 g) g), dichlorobis[di-t-butyl(4-dimethylaminophenyl)phosphino]palladium(II) (Pd-132, 0.35g) and xylene (100ml) as a palladium catalyst were put into a reactor and heated under reflux for 5 hours. did After cooling the reaction mixture to room temperature, aqueous ammonium chloride solution was poured into it, and the aqueous layer was extracted with toluene. The obtained organic layer was washed with water and dried over anhydrous magnesium sulfate. This solution was concentrated under reduced pressure, and the residue was purified by silica gel chromatography (toluene) to obtain compound (T-3) (5.5 g).

2nd process

To a flask containing compound (T-3) (0.9 g) and tert-butylbenzene (7.0 ml), a 1.6 M tert-butyllithium pentane solution (1.5 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 (0.61 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 (0.42 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 (eluent: toluene), the solvent was distilled off under reduced pressure, the obtained solid was dissolved in toluene, and heptane was added to cause reprecipitation to obtain a compound represented by formula (1-1) .

MALDI-TOF-MS(M+)=737.49

Synthesis Example (1-2):

Synthesis of compound (1-1)

1st process

Under nitrogen atmosphere, compound (T-9) (5.6 g), compound (T-10) (3.4 g), tert-butoxysodium (2.9 g), dichlorobis[di-t-butyl (4- Dimethylaminophenyl)phosphino]palladium(II) (Pd-132, 0.35g) and xylene (100ml) were put into a reactor and heated to reflux for 5 hours. After cooling the reaction mixture to room temperature, aqueous ammonium chloride solution was poured into it, and the aqueous layer was extracted with toluene. The obtained organic layer was washed with water and dried over anhydrous magnesium sulfate. The solution was concentrated under reduced pressure, and the residue was purified by silica gel chromatography (toluene) to obtain compound (T-3) (5.9 g).

The 2nd process is the same as the synthesis example (1-1).

MALDI-TOF-MS(M+)=737.49

Synthesis Example (2):

Synthesis of compound (1-24)

It synthesize|combined by the method according to the 2nd process of synthesis example (1-1).

MALDI-TOF-MS(M+)=793.46

Synthesis Example (3):

Synthesis of compound (1-31)

It synthesize|combined by the method according to the 2nd process of synthesis example (1-1).

MALDI-TOF-MS(M+)=774.48

Synthesis Example (4):

Synthesis of compound (1-34)

It synthesize|combined by the method according to the 2nd process of synthesis example (1-1).

MALDI-TOF-MS(M+)=873.33

Synthesis Example (5):

Synthesis of compound (1-42)

It synthesize|combined by the method according to the 2nd process of synthesis example (1-1).

MALDI-TOF-MS(M+)=735.47

Synthesis Example (6):

Synthesis of compound (1-48)

It synthesize|combined by the method according to the 2nd process of synthesis example (1-1).

MALDI-TOF-MS(M+)=713.49

Synthesis Example (7):

Synthesis of compound (1-51)

To a flask containing compound (T-4) (0.7 g) and tert-butylbenzene (7.0 ml), a 1.6 M tert-butyllithium pentane solution (1.5 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 (0.61 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 (0.42 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 (eluent: toluene), the solvent was distilled off under reduced pressure, the obtained solid was dissolved in toluene, and heptane was added to cause reprecipitation, thereby obtaining a compound represented by formula (1-51) .

MALDI-TOF-MS(M+)=1133.45

Synthesis Example (8):

Synthesis of compound (1-52)

(T-4) was replaced with (T-9) and synthesized according to Synthesis Example (7).

MALDI-TOF-MS(M+)=1170.45

Synthesis Example (9):

Synthesis of compound (2-3)

1st process

Compound (T-5) was synthesized by a method according to the second step of Synthesis Example (1-1).

2nd process

Under nitrogen atmosphere, compound (T-5) (5.3g), compound (T-6) (4.1g), tert-butoxysodium (2.9g), Pd-132 (0.35g) and xylene (100ml), It was put into a reactor and heated to reflux for 5 hours. After cooling the reaction mixture to room temperature, aqueous ammonium chloride solution was poured into it, and the aqueous layer was extracted with toluene. The obtained organic layer was washed with water and dried over anhydrous magnesium sulfate. This solution was concentrated under reduced pressure, and the residue was purified by silica gel chromatography (toluene) to obtain compound (2-3) (4.8 g).

MALDI-TOF-MS(M+)=737.49

Synthesis Example (10):

Synthesis of compound (2-4)

It synthesized by the method according to the 2nd process of synthesis example (9).

MALDI-TOF-MS(M+)=890.31

Synthesis Example (11):

Synthesis of compound (2-9)

It synthesized by the method according to the 2nd process of synthesis example (9).

MALDI-TOF-MS(M+)=917.31

Synthesis Example (12):

Synthesis of compound (1-201)

It synthesize|combined by the method according to the 2nd process of synthesis example (1-1).

MALDI-TOF-MS(M+)=795.47

Synthesis Example (13):

Synthesis of compound (1-202)

It synthesize|combined by the method according to the 2nd process of synthesis example (1-1).

MALDI-TOF-MS(M+)=1096.66

Synthesis Example (14):

Synthesis of compound (1-203)

It synthesize|combined by the method according to the 2nd process of synthesis example (1-1).

MALDI-TOF-MS(M+)=1082.60

Synthesis Example (15):

Synthesis of compound (1-204)

It synthesize|combined by the method according to the 2nd process of synthesis example (1-1).

MALDI-TOF-MS(M+)=965.64

Synthesis Example (16):

Synthesis of compound (1-205)

It synthesize|combined by the method according to the 2nd process of synthesis example (1-1).

MALDI-TOF-MS(M+)=927.57

Synthesis Example (17):

Synthesis of compound (1-206)

It synthesize|combined by the method according to the 2nd process of synthesis example (1-1).

MALDI-TOF-MS(M+)=987.62

Synthesis Example (18):

Synthesis of compound (1-207)

It synthesize|combined by the method according to the 2nd process of synthesis example (1-1).

MALDI-TOF-MS(M+)=963.53

Synthesis Example (19):

Synthesis of compound (1-208)

It synthesize|combined by the method according to the 2nd process of synthesis example (1-1).

MALDI-TOF-MS(M+)=915.47

Synthesis Example (20):

Synthesis of compound (1-209)

It synthesize|combined by the method according to the 2nd process of synthesis example (1-1).

MALDI-TOF-MS(M+)=791.44

Synthesis Example (21):

Synthesis of compound (1-210)

It synthesize|combined by the method according to the 2nd process of synthesis example (1-1).

MALDI-TOF-MS(M+)=829.50

Synthesis Example (22):

Synthesis of compound (1-211)

It synthesize|combined by the method according to the 2nd process of synthesis example (1-1).

MALDI-TOF-MS(M+)=733.42

Synthesis Example (23):

Synthesis of compound (1-212)

It synthesize|combined by the method according to the 2nd process of synthesis example (1-1).

MALDI-TOF-MS(M+)=813.43

Synthesis Example (24):

Synthesis of compound (1-213)

It synthesize|combined by the method according to the 2nd process of synthesis example (1-1).

MALDI-TOF-MS(M+)=895.60

Synthesis Example (25):

Synthesis of compound (1-214)

It synthesize|combined by the method according to the 2nd process of synthesis example (1-1).

MALDI-TOF-MS(M+)=867.57

Synthesis Example (26):

Synthesis of compound (1-215)

It synthesize|combined by the method according to the 2nd process of synthesis example (1-1).

MALDI-TOF-MS(M+)=959.59

Synthesis Example (27):

Synthesis of compound (1-216)

It synthesize|combined by the method according to the 2nd process of synthesis example (1-1).

MALDI-TOF-MS(M+)=999.66

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.

Fabrication of organic EL device

The following organic EL device was manufactured using the polycyclic aromatic compound of the present invention.

<Example 1-1 to Example 1-22 and Comparative Example 1>

The material constitution of each layer in the organic EL device of Examples 1-1 to 1-22 and Comparative Example 1 is shown in Table 1 below.

[Table 1]

In Table 1, "HI" is N4,N4'-diphenyl-N4,N4'-bis(9-phenyl-9H-carbazol-3-yl)-[1,1'-biphenyl]-4, 4'-diamine, "HAT-CN" is 1,4,5,8,9,12-hexaazatriphenylene hexacarbonitrile, "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, and "HT-2" is N,N-bis(4-(dibenzo[b,d]furan-4-yl)phenyl)-[1,1':4',1"-terphenyl]-4-amine, and "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 Chemical structure shown below together with "Liq" and comparative compound (1) (compound described in International Publication No. 2015/102118) indicates

[Example 1-1]

A 26 mm x 28 mm x 0.7 mm glass substrate (manufactured by Opto Science Co., Ltd.) obtained by polishing ITO film formed to a thickness of 180 nm by sputtering to 150 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 heated to deposit a film thickness of 45 nm, 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. Thereafter, 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.

[Example 1-2 to Example 1-22, Comparative Example 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 items and evaluation method

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, for example, values at 1000 cd/m ² light emission can be used.

The quantum efficiency of a light emitting device 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 device 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, and photons generated in the light emitting layer are partially absorbed or continuously reflected inside the light emitting element, thereby 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. Using a voltage/current generator R6144 manufactured by Advantist, a voltage such that the luminance of the element is 1000 cd/m ² is applied to cause the element to emit light. The spectral emission luminance in the visible light region was measured from a direction perpendicular to the light emitting surface using a spectroscopic emission luminance meter 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. Then, the number of photons in the entire observed wavelength range is integrated, and the total number of photons emitted from the device is taken. 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.

For the organic EL devices of Examples 1-1 to 1-22 and Comparative Example 1, DC voltage was applied using the ITO electrode as the anode and the LiF/aluminum electrode as the cathode, and the characteristics at the time of 1000 cd/m ² emission were measured. measured, and also measured the time to retain the luminance of 90% or more of the initial luminance.

The results are shown in Table 2.

[Table 2]

Examples 1-1 to 1-22 exhibited shorter peak wavelengths and higher efficiencies compared to Comparative Example 1.

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

Organic EL devices according to Examples 2 to 4 and Comparative Examples 2 to 4 (each Example and Comparative Example shown in Table 3) were fabricated, and the external quantum efficiency and LT50 (initial luminance of 1000 cd/m ² at a luminance of 1000 cd/m 2 ) were prepared. Time until reaching 500 cd/m ² when continuously driven at a current density of m ² ) was measured.

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

[Table 3]

[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 50 nm was used as a transparent support substrate. A molybdenum evaporation boat in which 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, and ET7 were placed, respectively; A boat for evaporation made of tungsten 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 weight 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. Thereafter, 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.

The chemical structures in Table 3 and Comparative Example 2-1 are shown below.

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

Each element was produced by changing the hole transport layer 2, the light emitting layer, and the electron transport layer 1 of Comparative Example 2-1 to the materials and concentrations shown in Table 3.

Table 4 shows the evaluation results of each element.

[Table 4]

From the comparison with Comparative Examples, it is found that high efficiency and long lifetime can be obtained by using a polycyclic aromatic compound having a structure containing the structural unit represented by Formula (1). Further, from the comparison between the examples, the use of compound (1-31) results in a longer lifetime, and the use of compounds (1-51) and (1-52) results in higher efficiency. High efficiency is obtained with the configuration of Example 3 or Example 4, and the highest efficiency is obtained with the configuration of Example 4.

The polycyclic aromatic compound having a structure including the structural unit represented by Formula (1) is an emitting dopant of a TADF element, an emitting dopant of a TADF element using two types of hosts, an emitting dopant of a TAF element, and a phosphorescent assist element. It can be used for the emitting dopant of From the viewpoint of ease of manufacturing as the number of materials used in the element is reduced, the TADF element emitting dopant and the TADF element emitting dopant using two types of host are preferable, and the TADF element emitting dopant is more preferable. From the viewpoint of efficiency, the TAF element's emitting dopant and the phosphorescent assist element's emitting dopant are preferred, and the TAF element's emitting dopant is more preferred.

<Examples 5 to 7 and Comparative Examples 5 to 6>

Organic EL devices according to Examples 5 to 7 and Comparative Examples 5 to 6 (each Example and Comparative Example shown in Table 5) were fabricated, and the external quantum efficiency and LT50 (initial luminance of 1000 cd/m ² at a luminance of 1000 cd/m 2 ) were prepared. Time until reaching 500 cd/m ² when continuously driven at a current density of m ² ) was measured.

[Table 5]

<Comparative Example 5-1> (same as 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 50 nm was used as a transparent support substrate. A molybdenum evaporation boat in which 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, and ET7 were placed, respectively; A boat for evaporation made of tungsten 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 weight 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. Thereafter, 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.

The chemical structures in Table 5 and Comparative Example 5-1 are shown below.

<Examples 5-1 to 3, Examples 6-1 to 3, Examples 7-1 to 2, Comparative Examples 5-1 and Comparative Examples 6-1>

Each element was fabricated by changing the hole transport layer 2, the light emitting layer, and the electron transport layer 1 of Comparative Example 2-1 to the materials and concentrations shown in Table 5.

Table 6 shows the evaluation results of each element.

[Table 6]

From the comparison with Comparative Examples, it is found that high efficiency and long lifetime can be obtained by using a polycyclic aromatic compound having a structure containing the structural unit represented by Formula (2). It is also understood that compounds (2-3) and compounds (2-9) having no azine ring can also be used for the hole transport layer 2.

A polycyclic aromatic compound having a structure including the structural unit represented by formula (2) can be used as the hole transport layer 2, host 1, or host 2, but it is preferably used as host 1 or host 2, and used as host 1 it is more preferable

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 (22)

Polycyclic aromatic compound which has a structure containing the structural unit represented by Formula (1);

In formula (1),
Ring A and ring B are each independently a substituted or unsubstituted aryl ring or a substituted or unsubstituted heteroaryl ring,
C ring is a substituted or unsubstituted hydrocarbon ring or a substituted or unsubstituted hetero ring;
X ¹ is >O, >NR, >C(-R) ₂ , >Si(-R) ₂ , >S, or >Se, wherein R in >NR is hydrogen, substituted or unsubstituted aryl, substituted Or unsubstituted heteroaryl, substituted or unsubstituted alkyl, or substituted or unsubstituted cycloalkyl, wherein R in >C(-R) ₂ and >Si(-R) ₂ is each independently hydrogen, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted alkyl, or substituted or unsubstituted cycloalkyl, wherein >C(-R) ₂ and >Si(-R) ₂ of 2 The two R's may be bonded to each other to form a ring, and the R of >NR, the >C(-R) ₂ and the R of >Si(-R) ₂ are ring A and/or by a linking group or a single bond. It may be bonded to ring B,
The broken line represents a divalent group linking two nitrogen atoms, and the divalent group may be bonded to the A ring and/or the C ring,
In the above structure, at least one selected from the group consisting of an aryl ring and a heteroaryl ring may be condensed with at least one cycloalkane, 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 cyano, halogen or deuterium. According to claim 1,
polycyclic aromatic compounds in which the divalent group connecting two nitrogen atoms is represented by the following formula;

D ring is a substituted or unsubstituted hydrocarbon ring or a substituted or unsubstituted hetero ring, two * indicates the bonding position with two nitrogen atoms,
Ring D may be further bonded to ring A and/or ring C through a linking group or single bond. According to claim 2,
Formula (1-a), Formula (1-b), Formula (1-c), Formula (1-d), Formula (1-f), Formula (1-g), Formula (1-h), and polycyclic aromatic compounds represented by any one formula selected from the group consisting of formula (1-i);

Formula (1-a), Formula (1-b), Formula (1-c), Formula (1-d), Formula (1-f), Formula (1-g), Formula (1-h), and In formula (1-i),
Z is each independently N or CR ^Z , R ^Z is each independently hydrogen or any one substituent selected from substituent group Z,
Two adjacent R ^Z may be bonded to each other to form an aryl ring or heteroaryl ring, and each of the formed aryl ring or heteroaryl ring may be substituted with any one substituent selected from substituent group Z,
Z=Z may each independently be >O, >NR, >C(-R) ₂ , >Si(-R) ₂ , >S, or >Se, wherein >NR and >C(-R) ₂ , and R in >Si(-R) ₂ are each independently hydrogen, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted alkyl, or substituted or unsubstituted cycloalkyl, The two Rs of >C(-R) ₂ and >Si(-R) ₂ may be bonded to each other to form a ring;
X ² and X ⁴ are each independently >O, >NR, >C(-R) ₂ , >S, or >Se, wherein R in >NR is hydrogen, substituted or unsubstituted aryl, substituted or unsubstituted A substituted heteroaryl, a substituted or unsubstituted alkyl, or a substituted or unsubstituted cycloalkyl, wherein each R in >C(-R) ₂ is independently hydrogen, a substituted or unsubstituted aryl, or a substituted or unsubstituted hetero aryl, substituted or unsubstituted alkyl, or substituted or unsubstituted cycloalkyl, wherein >NR and >C(-R) ₂ are one or two or more Z bonded to the same carbon atom, and R may be combined in
In the above structure, at least one of the aryl ring or heteroaryl ring may be condensed with at least one cycloalkane, the cycloalkane may be substituted with at least one substituent, and at least one of the cycloalkanes -CH ₂ - of may be substituted with -O-;
At least one hydrogen in the above structure may be substituted with cyano, halogen or deuterium;
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
made from substituted silyl. According to claim 3,
Z is all CR ^Z ,
A polycyclic aromatic compound wherein all X ² are >NR and X ⁴ are >O, >NR, or >S. According to claim 3 or 4,
A polycyclic aromatic compound in which each R ^Z is independently hydrogen, alkyl, phenyl which may be substituted with alkyl, diphenylamino which may be substituted with alkyl, or carbazolyl which may be substituted with alkyl. According to any one of claims 3 to 5,
A polycyclic aromatic compound represented by any one formula selected from the group consisting of formula (1-f), formula (1-g), formula (1-h), and formula (1-i). According to claim 1,
polycyclic aromatic compounds represented by any of the following formulas;

In the formula, tBu is t-butyl. According to any one of claims 3 to 5,
A polycyclic aromatic compound represented by any one formula selected from the group consisting of formula (1-a), formula (1-b), formula (1-c), and formula (1-d),
Any one formula selected from the group consisting of Formula (B101), Formula (B102), Formula (B103), Formula (B104), Formula (B105), Formula (B106), Formula (B107), and Formula (B108) A polycyclic aromatic compound containing at least one partial structure represented by;

during the ceremony,
Z has the same meaning as Z in formulas (1-a), (1-b), (1-c), and (1-d);
X ⁵ is >O, >NR, >C(-R) ₂ , >S, or >Se, wherein R of >NR is hydrogen, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted alkyl, substituted or unsubstituted cycloalkyl, wherein R in >C(-R) ₂ is each independently hydrogen, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted Alkyl or substituted or unsubstituted cycloalkyl, >C(-R) ₂ Two R's may be bonded to each other to form a ring, n is an integer of 1 to 3,
Me is methyl. According to claim 8,
polycyclic aromatic compounds represented by any of the following formulas;

In the formula, Me is methyl, tBu is t-butyl, Ad is 1-adamantyl, and tAm is t-amyl. polycyclic aromatic compounds having a structure containing a structural unit represented by the following formula (2);

In formula (2),
Z is each independently N or CR ^Z , R ^Z is each independently hydrogen or any one substituent selected from substituent group Z,
Two adjacent ^RZs may be bonded to each other to form an aryl ring or heteroaryl ring, and the formed aryl ring or heteroaryl ring may each be substituted with any one substituent selected from substituent group Z,
At least one selected from the group consisting of substituents of rings formed by bonding R ^Z and adjacent R ^Z are selected from the group consisting of formula (A-1), formula (A-2) and formula (A-3) It is a group represented by the formula,
Z=Z may each independently be >O, >NR, >C(-R) ₂ , >Si(-R) ₂ , >S, or >Se, wherein >NR and >C(-R) ₂ And R of >Si(-R) ₂ is each independently hydrogen, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted alkyl, or substituted or unsubstituted cycloalkyl, wherein >C(-R) ₂ and the two Rs of >Si(-R) ₂ may be bonded to each other to form a ring;
In formula (A-1),
W ¹ and W ² are each independently a single bond, >C(-R ^W ) ₂ , >NR ^W , >O, >Si(-R ^W ) ₂ , >S, >SO or >SO ₂ ,
R ^W of >NR ^W is any substituent selected from substituent group Z, a group represented by formula (A-2), or a group represented by formula (A-3),
R ^W of >C(-R ^W ) ₂ and >Si(-R ^W ) ₂ are each independently hydrogen, any one substituent selected from substituent group Z, a group represented by formula (A-2), or It is a group represented by formula (A-3),
R ^W bonded to the same element may be bonded to each other,
R W of >NR ^W , >C(-R ^W ) ₂ , and >Si(-R ^{W )} ₂ may be each independently bonded to at least one Y;
Y is N or CR ^Y , R ^Y is each independently hydrogen, any substituent selected from substituent group Z, a group represented by formula (A-2), or a group represented by formula (A-3) is,
R ^Y in adjacent Y may be bonded to each other to form an aryl ring or a heteroaryl ring, and the formed ring is any one of substituents selected from the substituent group Z, a group represented by formula (A-2), or a formula It may have a group represented by (A-3),
L ¹ is a single bond or a linking group;
L ¹ is bonded to C of any one of CR ^Y with R ^Y as a bond hand, or >C(-R ^{W )} ₂ of C, >NR ^W of N, >O, with R W as a bond hand >Si(-R ^W ) ₂ is bonded to Si, or bonded to a ring constituting atom of a ring formed by bonding R ^Y in Y to each other;
* represents the bonding position of the group represented by formula (A-1),
In formula (A-2),
Y is N or CR ^Y , R ^Y is each independently hydrogen, any substituent selected from substituent group Z, a group represented by formula (A-1), or a group represented by formula (A-3) ego,
R ^Y in adjacent Y may be bonded to each other to form an aryl ring or a heteroaryl ring, and the formed ring is any one of substituents selected from substituent group Z, a group represented by formula (A-1), or a formula may have a group represented by (A-3);
L ² is a single bond or a linking group;
L ² is bonded to C of any C R ^Y with R ^Y as a bond hand, or bonded to a ring-constituting atom of a ring formed by bonding R ^Y in Y to each other;
* represents the bonding position of the group represented by formula (A-2),
In formula (A-3),
Ar ³ is each independently selected from at least one substituent selected from substituent group Z, aryl optionally substituted with a group represented by formula (A-1) or formula (A-2), and at least one selected from substituent group Z a heteroaryl which may be substituted with a substituent or a group represented by formula (A-1) or formula (A-2), or a group represented by formula (A-1) or formula (A-2);
W ³ is Si, P or S;
When W ³ is Si, m is 3 and n is 0. When W ³ is P, m is 2 and n is 0 or 1. When W ³ is S, m is 1 and n is 0 to 2. is an integer of
L ³ is a single bond or a linking group;
* represents the bonding position of the group represented by formula (A-3),
In the above structure, at least one of the aryl ring or heteroaryl ring may be condensed with at least one cycloalkane, and at least one hydrogen in the cycloalkane may be substituted, and in the cycloalkane At least one -CH ₂ - may be substituted with -O-;
At least one hydrogen in the above structure may be substituted with cyano, halogen or deuterium;
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
made from substituted silyl. According to claim 10,
L ¹ , L ² and L ³ are, each independently, a single bond, arylene which may be substituted with aryl or heteroaryl, heteroarylene which may be substituted with aryl or heteroaryl, >NR ^L , >O;>C(-R ^L ) ₂ , >Si(-R ^L ) ₂ , >S, >Se, and a linking group selected from the group consisting of a combination of two or more thereof,
R L in > ^{NR L} , >C(-R ^L ) ₂ and >Si(-R ^L ) ₂ in L ¹ , L ² and L ³ is each independently selected from hydrogen and substituent group Z. A polycyclic aromatic compound which is one substituent or a group represented by formula (A-1), formula (A-2) or formula (A-3), and R ^L bonded to the same element may be bonded to each other. According to claim 10 or 11,
In formula (2), at least one of R ^Z is a group represented by formula (A-1), provided that when R ^Z are bonded to each other to form a ring, in the group consisting of the substituent of the ring and R ^Z At least one selected is a group represented by formula (A-1),
A polycyclic aromatic compound wherein W ¹ is >NR ^W , >C(-R ^W ) ₂ , >O, >Si(-R ^W ) ₂ , or >S, and W ² is a single bond. According to claim 12,
L ¹ is a single bond, W ¹ is >NR ^W ,
L ¹ is bonded to N of >NR ^W with R ^W as a bond,
A polycyclic aromatic compound containing at least one R ^Y that is a group represented by formula (A-2), a group represented by formula (A-3), or N-carbazolyl. According to any one of claims 10 to 13,
In formula (2), at least one of R ^Z is a group represented by formula (A-2), provided that when R ^Z are bonded to each other to form a ring, in the group consisting of the substituent of the ring and R ^Z At least one selected is a group represented by formula (A-2),
A polycyclic aromatic compound in which the group represented by formula (A-2) contains, as a partial structure, a pyridine ring, a pyrimidine ring, a pyrazine ring, or a triazine ring. According to any one of claims 10 to 14,
In formula (2), at least one of ^RZ is a group represented by formula (A-3), provided that when ^RZs are bonded to each other to form a ring, the group consisting of a group substituting the ring and ^RZ At least one selected from is a group represented by formula (A-3),
A polycyclic aromatic compound wherein W ³ is Si. According to claim 13,
A polycyclic aromatic compound represented by any of the following formulas.

A material for an organic device containing the polycyclic aromatic compound according to any one of claims 1 to 16. An organic electroluminescent device comprising a pair of electrodes comprising an anode and a cathode and an organic layer disposed between the pair of electrodes, wherein the organic layer contains the polycyclic aromatic compound according to any one of claims 1 to 16. . A pair of electrodes composed of an anode and a cathode and a light emitting layer disposed between the pair of electrodes,
The light-emitting layer contains a host material and the polycyclic aromatic compound according to any one of claims 1 to 9,
The organic electroluminescent device, wherein the lowest excitation triplet energy level of the host material is higher than the lowest excitation triplet energy level of the polycyclic aromatic compound. A pair of electrodes composed of an anode and a cathode and a light emitting layer disposed between the pair of electrodes, wherein the light emitting layer comprises at least two materials selected from the group consisting of a hole transporting host material, an electron transporting host material, and an assisting dopant; contains an emitter dopant;
An organic electroluminescent device wherein the emitting dopant is the polycyclic aromatic compound according to any one of claims 1 to 9. It has a pair of electrodes composed of an anode and a cathode and a light emitting layer disposed between the pair of electrodes,
The light-emitting layer contains the polycyclic aromatic compound according to any one of claims 10 to 16 as a dopant material and a host material,
The lowest excitation triplet energy level of the polycyclic aromatic compound is higher than the lowest excitation triplet energy level of the dopant material. A display device or lighting device comprising the organic electroluminescent device according to any one of claims 18 to 21.

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