JP2023081468A - Triazine compound - Google Patents

Abstract

SOLUTION: Compounds represented by a formula (1) are useful as materials for organic devices such as organic electrolytic light emitting devices. (X is heteroarylene; Y1 is a group represented by a formula (1-a); Y2 is a group represented by a formula (1-b); A1, A2, A3, and A4 are substituted or unsubstituted aryl or substituted or unsubstituted heteroaryl, and at least one of A1 and A2 or at least one of A3, and A4 is a group with N as a bonding position; Z1, Z2, and Z3 are CH or N, at least one of which is N; and * denotes a bonding position. At least one hydrogen in the compounds represented by the formula (1) may be replaced by cyano, halogen, or deuterium.)SELECTED DRAWING: None

Description

TECHNICAL FIELD The present invention relates to a triazine compound, an organic electroluminescent device using the same, a display device and a lighting device.

Conventionally, display devices using light-emitting elements that emit electroluminescence have been studied in various ways because they can be reduced in power consumption and thickness. Further, organic electroluminescence elements made of organic materials can be easily reduced in weight and increased in size. has been actively investigated. In particular, the development of organic materials that emit light in one of the three primary colors of light, such as blue and green, and the ability to transport electrons and holes (potentially becoming semiconductors and superconductors). The development of materials has been actively researched, regardless of whether they are high-molecular compounds or low-molecular-weight compounds.

An organic EL element has a structure comprising a pair of electrodes consisting of an anode and a cathode, and one or more layers interposed between the pair of electrodes and containing an organic compound. Layers containing organic compounds include light-emitting layers and charge transport/injection layers that transport or inject charges such as holes and electrons. Various organic materials suitable for these layers have been developed.

Currently, three types of luminescent materials are used for the luminescent layer: fluorescent materials, phosphorescent materials, and thermally activated delayed fluorescence (TADF) materials. For example, fluorescent materials such as improved azaborine derivatives have been reported (Patent Document 1), and phosphorescent materials such as noble metal complexes having multidentate ligands have been developed (Patent Document 2). Carbazonitrile compounds and the like have been developed as delayed fluorescence (TADF) materials (Non-Patent Document 1).

In devices using any material, a material with a high lowest excited singlet energy level or lowest excited triplet energy level is used for the emitting layer in order to prevent energy leakage from the emitting layer or peripheral layers, which leads to a decrease in efficiency. Used for adjacent layers or hosts. In Patent Document 3, a compound having at least two donor sites and at least two acceptor sites, in which the same number of donor sites and acceptor sites are present in the same molecule, is used as a host for a light-emitting layer to improve device performance. was obtained.

WO2015/102118 JP 2014-239225 A U.S. Patent Application Publication No. 2020/0020867

Nature Vol.492 13 December 2012

As described above, various materials have been developed for use in organic EL devices. However, in order to increase options for organic EL device materials, it is desirable to develop materials that are composed of compounds that are different from conventional materials. It is rare. In addition, Patent Document 1 reports a polycyclic aromatic compound containing boron and an organic EL device using the compound. There is a need for layer materials and peripheral layer materials.

The present inventors have made intensive studies to solve the above problems, and found that the novel triazine compound has a high lowest excited singlet energy level and a high electron transport property. Then, for example, such a triazine compound is used as a host material or a material of a layer adjacent to the light emitting layer, and a compound having a lower lowest excited triplet energy than that is used as a dopant material. A light emitting layer is arranged between a pair of electrodes. The inventors have found that an excellent organic EL device can be obtained by constructing the organic EL device, and completed the present invention. That is, the present invention provides the following triazine compounds, organic device materials containing the following triazine compounds, and the like.

式（１）中、
Ｘは、置換または無置換のヘテロアリーレンであり、
Ｙ¹は式（１－ａ）で表される基であり、
Ｙ²は式（１－ｂ）で表される基であり、 <1> compound represented by formula (1);

In formula (1),
X is substituted or unsubstituted heteroarylene;
Y ¹ is a group represented by formula (1-a),
Y ² is a group represented by formula (1-b),

A ¹ and A ² are each independently substituted or unsubstituted aryl or substituted or unsubstituted heteroaryl;
A ³ and A ⁴ are each independently substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted diarylamino, substituted or unsubstituted diheteroarylamino, or substituted or unsubstituted arylheteroarylamino,
at least one of A ¹ and A ² or A ³ and A ⁴ is a group having N as a bonding position;
Z ¹ , Z ² and Z ³ are each independently CH or N, but at least one of Z ¹ , Z ² and Z ³ is N;
* indicates the binding position,
At least one hydrogen in the compound represented by formula (1) may be replaced with cyano, halogen, or deuterium.

<2> Each group having N as the bonding position is independently substituted or unsubstituted N-carbazolyl, substituted or unsubstituted N-azacarbazolyl, substituted or unsubstituted N-benzimidazolyl, substituted or unsubstituted N - imidazoimidazolyl, substituted or unsubstituted N-indoloindolyl, substituted or unsubstituted N-indolocarbazolyl, substituted or unsubstituted N-benzofurocarbazolyl, substituted or unsubstituted N-benzothieno The compound according to <1>, which is carbazolyl or substituted or unsubstituted N-indenocarbazolyl.

<3> The compound according to <1> or <2>, wherein both A ¹ and A ² are groups having N as the bonding position.
<4> heteroarylene in X optionally has two hydrogen atoms bonded to ring atoms of carbazole, azacarbazole, benzimidazole, imidazoimidazole, indoloindole, indolocarbazole, benzofurocarbazole, benzothienocarbazole or indenocarbazole; The compound according to any one of <1> to <3>, which is a divalent group with one removed.

<5> The compound according to any one of <1> to <4>, wherein Z ¹ , Z ² and Z ³ are all N;
<6><1> to <5>, wherein both A ¹ and A ² are unsubstituted N-carbazolyl, and both A ³ and A ⁴ are unsubstituted N-carbazolyl or unsubstituted phenyl A compound according to any one of the above.

<7> The compound according to <1>, represented by any one of the following formulas.

<8> An organic device material containing the compound according to any one of <1> to <7>.
<9> A pair of electrodes consisting of an anode and a cathode, and an organic layer disposed between the pair of electrodes, wherein the organic layer contains the compound according to any one of <1> to <7>. An organic electroluminescence device.
<10> The organic electroluminescence device according to <9>, wherein the organic layer is a light-emitting layer.
<11> The organic electroluminescence device according to <10>, wherein the light-emitting layer contains the compound as a host material and further contains a dopant material.
<12> The organic electroluminescence device according to <9>, wherein the organic layer is an electron transport layer.
<13> A display device or lighting device comprising the organic electroluminescence device according to any one of <9> to <12>.

According to a preferred embodiment of the present invention, the quantum efficiency and the An organic EL device having excellent device life can be provided.

1 is a schematic cross-sectional view showing an organic EL element according to this embodiment; FIG. FIG. 3 is an energy level diagram showing the energy relationship between a host, an assisting dopant and an emitting dopant in a TAF device using a general fluorescent dopant. FIG. 2 is an energy level diagram showing an example of the energy relationship among a host, an assisting dopant, and an emitting dopant in an organic electroluminescence device of one embodiment of the present invention.

The present invention will be described in detail below. Although the constituent elements described below may be described based on representative embodiments and specific examples, the present invention is not limited to such embodiments. In the present specification, a numerical range represented by "-" means a range including the numerical values described before and after "-" as lower and upper limits. Further, "hydrogen" in the description of structural formulas in this specification means "hydrogen atom (H)". Similarly, "carbon atom (C)" may be referred to as "carbon".
As used herein, the term "adjacent groups" means two groups respectively bonded to two adjacent atoms (two atoms directly bonded by covalent bonds) in a 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, "Ad" is 1-adamantyl, "Ph" for phenyl, "Mes" for mesityl (2,4,6-trimethylphenyl), "Tf" for trifluoromethanesulfonyl, "TMS" for trimethylsilyl, and "D" for deuterium.
In this specification, the organic electroluminescence device is sometimes referred to as an organic EL device.

In this specification, chemical structures and substituents are sometimes represented by the number of carbon atoms. It refers to the number of carbon atoms in each group and does not refer to the total number of carbon atoms in the chemical structure and substituents, or the total number of carbon atoms in the substituent and substituents. For example, "a substituent B having a carbon number of Y substituted with a substituent A having a carbon number of X" means that a "substituent having a carbon number of Y" is substituted with a "substituent having a carbon number of X". However, the carbon number Y is not the total carbon number of the substituents A and B. Further, for example, “substituent B having Y carbon atoms and substituted with substituent A” means that “substituent B having Y carbon atoms” is substituted with “substituent A (with no carbon number limitation)”. However, the carbon number Y is not the total carbon number of the substituents A and B.

<Description of Ring and Substituent>
First, the details of the rings and substituents used herein are described below.

The "aryl ring" in the present specification includes, for example, an aryl ring having 6 to 30 carbon atoms, preferably an aryl ring having 6 to 16 carbon atoms, more preferably an aryl ring having 6 to 12 carbon atoms. Particularly preferred are 6-10 aryl rings.

Specific “aryl rings” include monocyclic benzene ring, bicyclic biphenyl ring, condensed bicyclic naphthalene ring and indene ring, tricyclic terphenyl ring (m-ter phenyl, o-terphenyl, p-terphenyl), condensed tricyclic acenaphthylene ring, fluorene ring, phenalene ring, phenanthrene ring, anthracene ring, condensed tetracyclic triphenylene ring, pyrene ring, naphthacene ring, Examples include a chrysene ring, a condensed pentacyclic perylene ring, and a pentacene ring. 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. In the fluorene ring, benzofluorene ring and indene ring, two of the two hydrogens of methylene in the structure are respectively replaced with alkyl such as methyl as a first substituent described later, resulting in a dimethylfluorene ring, Those having a dimethylbenzofluorene ring, a dimethylindene ring, and the like are also included.

As used herein, the "heteroaryl ring" includes, for example, a heteroaryl ring having 2 to 30 carbon atoms, preferably a heteroaryl ring having 2 to 25 carbon atoms, more preferably a heteroaryl ring having 2 to 20 carbon atoms. A heteroaryl ring having 2 to 15 carbon atoms is more preferable, and a heteroaryl ring having 2 to 10 carbon atoms is particularly preferable. The "heteroaryl ring" includes, for example, a heterocyclic ring containing 1 to 5 heteroatoms selected from oxygen, sulfur, nitrogen, phosphorus, selenium, etc. in addition to carbon as ring-constituting atoms.

Specific "heteroaryl rings" include, for example, pyrrole ring, oxazole ring, isoxazole ring, thiazole ring, isothiazole ring, imidazole ring, oxadiazole ring, thiadiazole ring, triazole ring, tetrazole ring, pyrazole ring, pyridine ring, pyrimidine ring, pyridazine ring, pyrazine ring, triazine ring, indole ring, isoindole ring, 1H-indazole ring, benzimidazole ring, benzoxazole ring, benzothiazole ring, 1H-benzotriazole ring, quinoline ring, isoquinoline ring , cinnoline ring, quinazoline ring, quinoxaline ring, phthalazine ring, naphthyridine ring, purine ring, pteridine ring, carbazole ring, acridine ring, phenoxathiine ring, phenoxazine ring, phenothiazine ring, phenazine ring, phenazacilline ring, indolizine ring, furan ring, benzofuran ring, isobenzofuran ring, dibenzofuran ring, thiophene ring, benzothiophene ring, dibenzothiophene ring, furazan ring, thianthrene ring, indolocarbazole ring, benzoindolocarbazole ring, dibenzoindolocarbazole ring, naphthobenzofuran ring, dioxin ring, dihydroacridine ring, xanthene ring, thioxanthene ring, dibenzodioxin ring, benzoselenophene ring, dibenzoselenophene ring, azacarbazole ring, azadibenzothiophene ring, azadibenzofuran ring, azadibenzoselenophene ring, azatriphenylene ring , imidazoimidazole ring, indoloindole ring, benzofurocarbazole ring, benzothienocarbazole ring, indenocarbazole ring and selenophenocarbazole ring. In the dihydroacridine ring, xanthene ring, thioxanthene ring, and indenocarbazole ring, two of the two hydrogens of methylene in the structure are respectively replaced with alkyl such as methyl as the first substituent described later. , dimethyldihydroacridine ring, dimethylxanthene ring, dimethylthioxanthene ring and the like are also preferred. Bipyridine ring, phenylpyridine ring and pyridylphenyl ring which are bicyclic ring systems, and terpyridyl ring, bispyridylphenyl ring and pyridylbiphenyl ring which are tricyclic systems are also mentioned as "heteroaryl ring". Moreover, a pyran ring shall also be contained in a "heteroaryl ring."

Substituents herein may be substituted with additional substituents. For example, a particular substituent may be described as "substituted or unsubstituted." This means that the particular substituent may or may not be substituted with at least one further substituent. In the same sense, it may be said to be "optionally substituted". In the present specification, the specific substituent at this time may be referred to as the "first substituent", and the additional substituent may be referred to as the "second substituent".

In the present specification, the term "substituent" may be any group selected from the substituent group Z, unless otherwise specified. For example, when a "substituted or unsubstituted" group is substituted, the group may be substituted with at least one group selected from the substituent group Z.

In the present specification, the substituent group Z is
aryl optionally substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl and cycloalkyl;
heteroaryl optionally substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl and cycloalkyl;
diarylamino optionally substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl and cycloalkyl (the two aryls may be bonded to each other via a linking group);
diheteroarylamino optionally 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 optionally substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl and cycloalkyl (aryl and heteroaryl may be ),
diarylboryl optionally substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl and cycloalkyl (the two aryls may be bonded via a single bond or a linking group);
alkyl optionally substituted with at least one group selected from the group consisting of aryl, heteroaryl and cycloalkyl;
cycloalkyl optionally substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl and cycloalkyl;
alkoxy optionally substituted with at least one group selected from the group consisting of aryl, heteroaryl and cycloalkyl;
It consists of aryloxy optionally substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl and cycloalkyl, and substituted silyl.
The second substituent aryl in each group of the substituent group Z may be further substituted with aryl, heteroaryl, alkyl, or cycloalkyl. Similarly, the second substituent heteroaryl is aryl, It may be optionally substituted with heteroaryl, alkyl, or cycloalkyl.

As used herein, "aryl" is, 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 of numbers 6 to 10 and the like.

A specific “aryl” includes a monovalent group obtained by removing one hydrogen from the above-mentioned “aryl ring”. For example, monocyclic phenyl, bicyclic biphenylyl (2-biphenylyl, 3-biphenylyl, or 4-biphenylyl), fused bicyclic naphthyl (1-naphthyl or 2-naphthyl), tricyclic Terphenylyl (m-terphenyl-2′-yl, m-terphenyl-4′-yl, m-terphenyl-5′-yl, o-terphenyl-3′-yl, o-terphenyl-4 '-yl, p-terphenyl-2'-yl, m-terphenyl-2-yl, m-terphenyl-3-yl, m-terphenyl-4-yl, o-terphenyl-2-yl, o-terphenyl-3-yl, o-terphenyl-4-yl, p-terphenyl-2-yl, p-terphenyl-3-yl, or p-terphenyl-4-yl), condensed tricyclic system, acenaphthylene-(1-, 3-, 4-, or 5-)yl, fluorene-(1-, 2-, 3-, 4-, or 9-)yl, phenalene-(1- or 2 -)yl, phenanthrene-(1-, 2-, 3-, 4-, or 9-)yl, or anthracen-(1-, 2-, or 9-)yl, tetracyclic quaterphenylyl (5'-phenyl-m-terphenyl-2-yl, 5'-phenyl-m-terphenyl-3-yl, 5'-phenyl-m-terphenyl-4-yl, or m-quaterphenyl) , a fused tetracyclic ring system, triphenylene-(1- or 2-)yl, pyren-(1-, 2-, or 4-)yl, or naphthacene-(1-, 2-, or 5-)yl, Or perylene-(1-, 2-, or 3-)yl, or pentacene-(1-, 2-, 5-, or 6-)yl, which are fused five-ring systems. Other examples include a monovalent group of spirofluorene.

The aryl as the second substituent includes aryl such as phenyl (specific examples are the groups described above), alkyl such as methyl (specific examples are groups described later), and cycloalkyl such as cyclohexyl or adamantyl. Structures substituted with at least one group selected from the group consisting of (specific examples are groups described later) are also included.
An example thereof is a group in which the 9-position of fluorenyl as the second substituent is substituted with aryl such as phenyl, alkyl such as methyl, or cycloalkyl such as cyclohexyl or adamantyl.

"Arylene" is, for example, arylene having 6 to 30 carbon atoms, preferably 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 10 carbon atoms. Arylene and others.
A specific “arylene” is, for example, a divalent group obtained by removing one hydrogen from the above-mentioned “aryl” (monovalent group).

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

A specific “heteroaryl” includes a monovalent group obtained by removing one hydrogen from the above-mentioned “heteroaryl ring”. For example pyrrolyl, oxazolyl, isoxazolyl, thiazolyl, isothiazolyl, imidazolyl, oxadiazolyl, thiadiazolyl, triazolyl, tetrazolyl, pyrazolyl, pyridyl, pyrimidinyl, pyridazinyl, pyrazinyl, triazinyl, indolyl, isoindolyl, 1H-indazolyl, benzimidazolyl, benzoxazolyl, benzothiazolyl , 1H-benzotriazolyl, quinolinyl, isoquinolinyl, cinnolinyl, quinazolinyl, quinoxalinyl, phenanthrolinyl, phthalazinyl, naphthyridinyl, purinyl, pteridinyl, carbazolyl, acridinyl, phenoxathiinyl, phenoxazinyl, phenothiazinyl, phenazinyl, phenazacilinyl, indolizinyl , furanyl, benzofuranyl, isobenzofuranyl, dibenzofuranyl, naphthobenzofuranyl, thienyl, benzothienyl, isobenzothienyl, dibenzothienyl, naphthobenzothienyl, benzoselenophenyl, dibenzoselenophenyl, azacarbazolyl, azadibenzothiophenyl, azadibenzofuranyl, azadibenzoselenophenyl, azatriphenylenyl, imidazoimidazolyl, indoloindolyl, benzofurocarbazolyl, benzothienocarbazolyl, indenocarbazolyl and selenophenocarbazolyl, benzophosphoryl, dibenzo phosphoryl, a monovalent group of a benzophosphole oxide ring, a monovalent group of a dibenzophosphole oxide ring, furazanyl, thianthrenyl, indolocarbazolyl, benzindolocarbazolyl, dibenzoindolocarbazolyl, imidazolinyl, or and oxazolinyl. Other examples include a spiro[fluorene-9,9'-xanthene] monovalent group and a spirobi[silafluorene] monovalent group.

The heteroaryl as the second substituent includes aryl such as phenyl (specific examples are the groups described above), alkyl such as methyl (specific examples are groups described later), and cyclohexyl or adamantyl. Structures substituted with at least one group selected from the group consisting of alkyl (specific examples are groups described later) are also included.
An example thereof is a group in which the 9-position of carbazolyl as the second substituent is substituted with aryl such as phenyl, alkyl such as methyl, or cycloalkyl such as cyclohexyl or adamantyl. In addition, groups in which nitrogen-containing heteroaryl such as pyridyl, pyrimidinyl, triazinyl and carbazolyl are 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, heteroarylene having 2 to 15 carbon atoms, or carbon Heteroarylene of numbers 2 to 10 and the like. Further, "heteroarylene" is a divalent group such as a heterocyclic ring containing, for example, 1 to 5 heteroatoms selected from oxygen, sulfur and nitrogen in addition to carbon as ring-constituting atoms.
A specific “heteroarylene” is, for example, a divalent group obtained by removing one hydrogen from the above-mentioned “heteroaryl” (monovalent group).

"Diarylamino" is amino substituted with two aryls, and the above description of "aryl" can be referred to for details of this aryl.
"Diheteroarylamino" is an amino group substituted with two heteroaryls, and the above description of "heteroaryl" can be referred to for details of this heteroaryl.
"Arylheteroarylamino" is an amino group substituted with aryl and heteroaryl, and the details of this aryl and heteroaryl can be referred to the above explanations of "aryl" and "heteroaryl".

Two aryls in the diarylamino as the first substituent may be bonded to each other via a linking group, and two heteroaryls in the diheteroarylamino as the first substituent may be bonded to each other via a linking group. The aryl and heteroaryl of the arylheteroarylamino as the first substituent may be bonded to each other via a linking group. Here, the description "bonded via a linking group" means that two phenyls such as diphenylamino form a bond via the linking group as shown below. This explanation also applies to diheteroarylamino and arylheteroarylamino formed by aryl and heteroaryl.

Specific examples of the linking groups include >O, >N—R ^x , >C(—R ^x ) ₂ , >Si(—R ^x ) ₂ , >S, >CO, >CS, >SO, >SO ₂ , and >Se. Each R ^X is independently alkyl, cycloalkyl, aryl, or heteroaryl, which may be substituted with alkyl, cycloalkyl, aryl, or heteroaryl. In addition, R ^X in >C(-R ^X ) ₂ and >Si(-R ^X ) ₂ may be bonded via a single bond or a linking group X ^Y to form a ring. X ^Y is >O, >N-R ^Y , >C(-R ^Y ) ₂ , >Si(-R ^Y ) ₂ , >S, >CO, >CS, >SO, >SO ₂ , and >Se and each ^RY is independently alkyl, cycloalkyl, aryl or heteroaryl, which may be substituted with alkyl, cycloalkyl, aryl or heteroaryl. However, when X ^Y is >C(-R ^Y ) ₂ and >Si(-R ^Y ) ₂ , the two R ^Y do not combine to form a further ring. Further examples of linking groups include alkenylene. Any hydrogen of said alkenylene may each independently be substituted with R ^X , each R ^X being independently alkyl, cycloalkyl, substituted silyl, aryl and heteroaryl, which are alkyl, cycloalkyl, It may be substituted with substituted silyl or aryl.

In the present specification, when simply described as "diarylamino", "diheteroarylamino", or "arylheteroarylamino", unless otherwise specified, "the two aryls of diarylamino are may be bonded to each other via a linking group", "two heteroaryls of the diheteroarylamino may be bonded to each other via a linking group", and "the aryl and the heteroaryl of the arylheteroarylamino aryl may be bonded to each other via a linking group".

"Diarylboryl" is boryl substituted with two aryls, and the above description of "aryl" can be referred to for details of this aryl. The two aryls may also be a single bond or a linking group (e.g., -CH=CH-, -CR=CR-, -C≡C-, >NR, >O, >S, >C(-R ) ₂ , >Si(-R) ₂ , or >Se). Here, 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 said R may be further substituted with aryl, heteroaryl, alkyl, alkenyl, alkynyl, or cycloalkyl. Also, two adjacent R's may combine to form a ring to form cycloalkylene, arylene, and heteroarylene. Further details of the substituents listed here can be found in the descriptions of "aryl", "arylene", "heteroaryl", "heteroarylene" and "diarylamino" above and "alkyl" and "alkenyl" below. , “alkynyl”, “cycloalkyl”, “cycloalkylene”, “alkoxy” and “aryloxy” descriptions can be cited. In addition, when simply described as "diarylboryl" in this specification, unless otherwise specified, "two aryls of diarylboryl may be bonded to each other via a single bond or a linking group." It is assumed that the explanation is added.

"Alkyl" may be either linear or branched, for example linear alkyl having 1 to 24 carbon atoms or branched alkyl having 3 to 24 carbon atoms, preferably alkyl having 1 to 18 carbon atoms (carbon 3 to 18 branched chain alkyl), C 1 to 12 alkyl (C 3 to 12 branched chain alkyl), C 1 to 6 alkyl (C 3 to 6 branched chain alkyl), carbon number Examples include alkyl of 1 to 5 (branched alkyl of 3 to 5 carbon atoms), alkyl of 1 to 4 carbon atoms (branched alkyl of 3 to 4 carbon atoms), and the like.

Specific "alkyl" include, 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-dimethyl Butyl, 1,1-diethylbutyl, 1-ethyl-1-methylbutyl, 1-propyl-1-methylbutyl, 1,1,3-trimethylbutyl, 1-ethyl-1,3-dimethylbutyl, n-pentyl, isopentyl , neopentyl, t-pentyl (t-amyl), 1-methylpentyl, 2-propylpentyl, 1,1-dimethylpentyl, 1-ethyl-1-methylpentyl, 1-propyl-1-methylpentyl, 1-butyl -1-methylpentyl, 1,1,4-trimethylpentyl, n-hexyl, 1-methylhexyl, 2-ethylhexyl, 1,1-dimethylhexyl, 1-ethyl-1-methylhexyl, 1,1,5- trimethylhexyl, 3,5,5-trimethylhexyl, n-heptyl, 1-methylheptyl, 1-hexylheptyl, 1,1-dimethylheptyl, 2,2-dimethylheptyl, 2,6-dimethyl-4-heptyl, n-octyl, 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, n-eicosyl, and the like.

"Alkylene" is a divalent group derived by removing any hydrogen from "alkyl", eg, methylene, ethylene, propylene.

For "alkenyl", the above description of "alkyl" can be referred to. Also includes groups in which two or more single bonds are substituted with double bonds (also called alkadien-yl or alkanetrien-yl).

"Alkenylene" is a divalent group obtained by removing any hydrogen from "alkenyl", such as vinylene.

For "alkynyl", the above description of "alkyl" can be referred to. Also included are groups in which two or more single bonds are replaced by triple bonds (also called alkadiyn-yl or alkanetriin-yl).

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

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). substituted, norbornenyl, bicyclo[1.1.0]butyl, bicyclo[1.1.1]pentyl, bicyclo[2.1.0]pentyl, bicyclo[2.1.1]hexyl, bicyclo[3.1 .0]hexyl, bicyclo[2.2.1]heptyl, bicyclo[2.2.2]octyl, adamantyl, diamantyl, decahydronaphthalenyl, or decahydroazulenyl.

"Cycloalkylene" is, for example, cycloalkylene having 3 to 24 carbon atoms, preferably cycloalkylene having 3 to 20 carbon atoms, cycloalkylene having 3 to 16 carbon atoms, cycloalkylene having 3 to 14 carbon atoms, and cycloalkylene having 3 to 14 carbon atoms. cycloalkylene having 3 to 12 carbon atoms, cycloalkylene having 5 to 10 carbon atoms, cycloalkylene having 5 to 8 carbon atoms, cycloalkylene having 5 to 6 carbon atoms, cycloalkylene having 5 carbon atoms, and the like.
A specific “cycloalkylene” is, for example, a structure in which one hydrogen is removed from the above-mentioned “cycloalkyl” (monovalent group) to form a divalent group.

“Cycloalkenyl” is a group having a structure in which at least one pair of single bonds between two carbon atoms in the above “cycloalkyl” is a double bond (for example, —CH ₂ —CH ₂ — is —CH= (groups substituted for CH--) which are not aryl groups. Specific examples include 1-cyclohexenyl, 1-cyclopentenyl and the like.

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

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

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

"Triarylsilyl" is a silyl group substituted with three aryls, and the above description of "aryl" can be referred to for details of this aryl.
A specific "triarylsilyl" is, for example, triphenylsilyl, diphenylmononaphthylsilyl, monophenyldinaphthylsilyl, or trinaphthylsilyl.

"Trialkylsilyl" is a silyl group substituted with three alkyls, and for details of this alkyl, the above description of "alkyl" can be cited.
Specific "trialkylsilyl" includes, for example, trimethylsilyl, triethylsilyl, tri-n-propylsilyl, triisopropylsilyl, tri-n-butylsilyl, triisobutylsilyl, tri-s-butylsilyl, tri-t-butylsilyl, ethyldimethylsilyl, n-propyldimethylsilyl, isopropyldimethylsilyl, n-butyldimethylsilyl, isobutyldimethylsilyl, s-butyldimethylsilyl, t-butyldimethylsilyl, methyldiethylsilyl, n-propyldiethylsilyl, isopropyldiethylsilyl, n-butyldiethyl silyl, s-butyldiethylsilyl, t-butyldiethylsilyl, methyldi-n-propylsilyl, ethyldi-n-propylsilyl, n-butyldi-n-propylsilyl, s-butyldi-n-propylsilyl, t-butyldi-n-propylsilyl, methyldiisopropylsilyl, ethyldiisopropylsilyl, n-butyldiisopropylsilyl, s-butyldiisopropylsilyl, t-butyldiisopropylsilyl, and the like.

"Tricycloalkylsilyl" is a silyl group substituted with three cycloalkyls, and for details of this cycloalkyl, the above description of "cycloalkyl" can be cited.
A specific "tricycloalkylsilyl" is, for example, tricyclopentylsilyl or tricyclohexylsilyl.

A "dialkylcycloalkylsilyl" is a silyl group substituted with two alkyls and one cycloalkyl, and the details of the alkyl and cycloalkyl can be referred to the above explanations of "alkyl" and "cycloalkyl".

"Alkyldicycloalkylsilyl" is a silyl group substituted with one alkyl and two cycloalkyls, and the details of this alkyl and cycloalkyl can be referred to the above explanations of "alkyl" and "cycloalkyl" .

<When two groups bonded to the same atom are bonded to each other>
In the present specification, when two groups bonded to the same atom may be bonded to each other to form a ring, if they are bonded by a single bond or a linking group (collectively referred to as a bonding group) Commonly, the linking groups include -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--, for example, 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 -Si(-R) ₂ - are each independently hydrogen, aryl optionally substituted with alkyl or cycloalkyl, heteroaryl optionally substituted with alkyl or cycloalkyl, or cycloalkyl optionally substituted alkyl, alkenyl optionally substituted with alkyl or cycloalkyl, alkynyl optionally substituted with alkyl or cycloalkyl, or cycloalkyl optionally substituted with alkyl or cycloalkyl . Also, two adjacent R's may combine to form a ring to form cycloalkylene, arylene, or heteroarylene.

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

The position where the two R are bonded by the bonding group is not particularly limited as long as it is a bondable position, but it is preferable to bond at the most adjacent position. For example, when the two groups are phenyl, "C" in phenyl It is preferable to bond at the ortho (2-position) positions with respect to the bonding position (1-position) of or “Si” (see the structural formula above).

1. Compounds of the Invention The triazine compounds of the invention are represented by formula (1).

In formula (1), Y ¹ is a group represented by formula (1-a) and Y ² is a group represented by formula (1-b). The triazine compound of the present invention has electron-accepting substituents such as triazinyl in which a plurality of electron-donating substituents (donor structures) such as heteroaryl having N as the bonding position are bonded as Y ¹ and/or Y ² . It has a group (acceptor structure). Specifically, in formula (1), both A ¹ and A ² , or at least one of A ³ and A ⁴ are groups with N as the bonding position.

＊は結合位置を示す。

* indicates the binding position.

In formula (1-a), A ¹ and A ² are each independently substituted or unsubstituted aryl or substituted or unsubstituted heteroaryl. In formula (1-b), A ³ and A ⁴ are each independently substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted diarylamino, substituted or unsubstituted di heteroarylamino, or substituted or unsubstituted arylheteroarylamino.

Phenyl is preferred as aryl in substituted or unsubstituted aryl for A ¹ , A ² , A ³ or A ⁴ . Heteroaryl in substituted or unsubstituted heteroaryl for A ¹ , A ² , A ³ or A ⁴ includes carbazolyl (especially N-carbazolyl), azacarbazolyl (especially N-azacarbazolyl), benzimidazolyl (especially N-benzimidazolyl), imidazoimidazolyl (especially N-imidazoimidazolyl), N-indoloindolyl (especially N-indoloindolyl), N-indolocarbazolyl (especially N-indolocarbazolyl), N-benzofurocarbazolyl (especially N-benzofurocarbazolyl), N-benzothienocarbazolyl (especially N-benzothienocarbazolyl), or N-indenocarbazolyl (especially N -indenocarbazolyl) is preferred, and N-carbazolyl is more preferred.

When aryl or heteroaryl in A ¹ , A ² , A ³ or A ⁴ is substituted, the substituent is preferably aryl or heteroaryl, phenyl, carbazolyl (especially N-carbazolyl), azacarbazolyl (especially N-azacarbazolyl), benzimidazolyl (especially N-benzimidazolyl), imidazoimidazolyl (especially N-imidazoimidazolyl), N-indoloindolyl (especially N-indoloindolyl), N-indolocarbazolyl (especially N-indolocarbazolyl), N-benzofurocarbazolyl (especially N-benzofurocarbazolyl), N-benzothienocarbazolyl (especially N-benzothienocarbazolyl), or N- Indenocarbazolyl (particularly N-indenocarbazolyl) is more preferred, and phenyl or N-carbazolyl is even more preferred. The position of the substituent is not particularly limited. The number of substituents is preferably 0 to 2, more preferably 0 to 1. It is particularly preferred that A ¹ , A ² , A ³ or A ⁴ are each independently unsubstituted phenyl or unsubstituted N-carbazolyl.

In the substituted or unsubstituted diarylamino, substituted or unsubstituted diheteroarylamino, or substituted or unsubstituted arylheteroarylamino that is A ³ or A ⁴ , diarylamino, diheteroarylamino, and arylheteroarylamino Phenyl is preferred as any substituent when is substituted. The number of substituents is preferably 0 to 2, more preferably 0 to 1. All diarylamino, diheteroarylamino and arylheteroarylamino are preferably unsubstituted. Preferred among these are unsubstituted diphenylamino.

In formula (1), both A ¹ and A ² and/or both A ³ and A ⁴ are groups with N as the bonding position. Thus, the compound represented by the formula (1) having a substituent in which an electron-accepting substituent such as triazinyl is substituted with a plurality of electron-donating nitrogen-substituting groups, as shown in Examples, It has a very high lowest excited singlet energy level compared to compounds without such substituents.

The group having N as the bonding position is preferably a group having an electron-donating structure as a whole, such as substituted or unsubstituted N-carbazolyl, substituted or unsubstituted N-azacarbazolyl, substituted or unsubstituted N-benzimidazolyl. , substituted or unsubstituted N-imidazoimidazolyl, substituted or unsubstituted N-indoloindolyl, substituted or unsubstituted N-indolocarbazolyl, substituted or unsubstituted N-benzofurocarbazolyl, substituted or Unsubstituted N-benzothienocarbazolyl or substituted or unsubstituted N-indenocarbazolyl is preferred.

The group having N as the bonding position is more preferably any one of the following groups. The groups below may have 1 to 2 substituents selected from the group consisting of unsubstituted phenyl and unsubstituted N-carbazolyl.

In formula (Aa-2) above, W is NH, NMe, NPh, O, S, or C(Me) ₂ . The two dotted lines in formula (Aa-2) are attached to two adjacent ring-constituting carbon atoms of the internal 6-membered ring at the ends of the dotted lines.

The group having N as the bonding position is particularly preferably a group represented by formula (Aa-1).

In formula (1), at least both A ¹ and A ² are preferably groups having N as the bonding position. That is, compounds of the invention preferably have triazinyl substituted with two substituted or unsubstituted heteroaryls with N as the point of attachment.
Any of A ¹ , A ² , A ³ and A ⁴ may be a group having N as the bonding position.

In formula (1-b), Z ¹ , Z ² and Z ³ are each independently CH or N, and at least one of Z ¹ , Z ² and Z ³ is N. That is, the group represented by formula (1-b) is triazinyl having A ³ and A ⁴ as substituents, pyridyl having A ³ and A ⁴ as substituents, or having A ³ and A ⁴ as substituents. It is pyrimidinyl. Z ¹ , Z ² and Z ³ are preferably all N.

In Formula (1), X is a substituted or unsubstituted heteroarylene. The heteroaryl ring constituting heteroarylene for X is an indole ring, a carbazole ring, a benzothiophene ring, a benzofuran ring, a benzoselenophene ring, a dibenzothiophene ring, a dibenzofuran ring, a dibenzoselenophene ring, a pyridine ring, a pyrimidine ring, a pyrazine ring, triazine ring, azacarbazole ring, azadibenzothiophene ring, azadibenzofuran ring, azadibenzoselenophene ring, azatriphenylene ring, imidazole ring, benzimidazole ring, pyrazole ring, oxazole ring, thiazole ring, isoxazole ring, isothiazole ring, selected from the group consisting of a triazole ring, a thiadiazole ring, an oxadiazole ring, an imidazoimidazole ring, an indoloindole ring, an indolocarbazole ring, a benzofurocarbazole ring, a benzothienocarbazole ring, an indenocarbazole ring and a selenophenocarbazole ring; It is preferable to be either Among these, electron-donating heteroaryl rings are preferred, and specific examples include carbazole ring, azacarbazole ring, benzimidazole ring, imidazoimidazole ring, indoloindole ring, indolocarbazole ring, benzofurocarbazole ring, and benzothieno. A carbazole ring or an indenocarbazole ring is more preferred. Although the binding position is not particularly limited, for example, the carbazole ring is preferably a divalent group with binding positions at the 3-position and the 9-position, or the 2-position and the 9-position. It is more preferable that it is a divalent group. Also, the indolocarbazole ring is preferably a divalent group having two N-bonded positions. A heteroaryl ring constituting heteroarylene in X is particularly preferably a carbazole ring.

When heteroarylene in X is substituted, the substituent is preferably aryl or heteroaryl, phenyl, carbazolyl (especially N-carbazolyl), azacarbazolyl (especially N-azacarbazolyl), benzimidazolyl (especially N-benzimidazolyl ), imidazoimidazolyl (especially N-imidazoimidazolyl), N-indoloindolyl (especially N-indoloindolyl), N-indolocarbazolyl (especially N-indolocarbazolyl), N-benzo furocarbazolyl (especially N-benzofurocarbazolyl), N-benzothienocarbazolyl (especially N-benzothienocarbazolyl), or N-indenocarbazolyl (especially N-indenocarbazolyl) carbazolyl) are more preferred, and phenyl or N-carbazolyl are even more preferred.

The position of the substituent for heteroarylene in X is not particularly limited. The number of substituents is preferably 0 to 2, more preferably 0 to 1. It is particularly preferred that X is unsubstituted heteroarylene.

At least one hydrogen in the compound represented by formula (1) may be replaced with deuterium, cyano, or halogen. Halogen is fluorine, chlorine, bromine or iodine, preferably fluorine, chlorine or bromine, more preferably fluorine or chlorine.

Specific examples of the compound of the present invention include compounds represented by any of the following structural formulas.

2. Method for producing a triazine compound The compounds represented by the formula (1) are a compound having a reactive group at a desired position of the nitrogen-containing 6-membered ring in the formula (1) and a compound having a reactive group at a desired position. can be produced by applying Suzuki coupling, Negishi coupling and other known reactions using as a starting material. Examples of reactive groups in these compounds include halogen and boronic acid.

3. Organic Device The triazine compound according to the present invention can be used as a material for organic devices. Organic devices include, for example, organic electroluminescence devices, organic field effect transistors, organic thin film solar cells, and the like.

3-1. Organic Electroluminescence Device Hereinafter, the organic EL device according to the present embodiment will be described in detail with reference to the drawings. FIG. 1 is a schematic cross-sectional view showing an organic EL element according to this embodiment.

<Structure of Organic Electroluminescent Device>
The 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 The hole-transporting layer 104 provided, the light-emitting layer 105 provided over the hole-transporting layer 104, the electron-transporting layer 106 provided over the light-emitting layer 105, and the electron-transporting layer 106 provided and a cathode 108 provided on the electron injection layer 107 .

Note that the organic EL element 100 is fabricated in reverse order, for example, the substrate 101, the cathode 108 provided on the substrate 101, the electron injection layer 107 provided on the cathode 108, and the electron injection layer 107 an electron transport layer 106 provided on the electron transport layer 106; a light emitting layer 105 provided on the electron transport layer 106; a hole transport layer 104 provided on the light emitting layer 105; A structure having a hole-injection layer 103 provided at the bottom and an anode 102 provided on the hole-injection layer 103 may be employed.

All of the above layers are not indispensable, and the minimum structural unit is composed of the anode 102, the light emitting layer 105, and the cathode 108, and the hole injection layer 103, the hole transport layer 104, the electron transport layer 106, and the electron injection Layer 107 is an optional layer. Moreover, each of the above layers may be composed of a single layer, or may be composed of a plurality of layers.

In addition to the configuration of the above-described "substrate/anode/hole injection layer/hole transport layer/light-emitting layer/electron transport layer/electron injection layer/cathode", the layers constituting the organic EL element may include " substrate/anode/hole-transporting layer/luminescent layer/electron-transporting layer/electron-injecting layer/cathode”, “substrate/anode/hole-injecting layer/luminescent layer/electron-transporting layer/electron-injecting layer/cathode”, “substrate/ Anode/Hole Injection Layer/Hole Transport Layer/Light Emitting Layer/Electron Injection Layer/Cathode", "Substrate/Anode/Hole Injection Layer/Hole Transport Layer/Light Emitting Layer/Electron Transport Layer/Cathode", "Substrate/ Anode/light emitting layer/electron transport layer/electron injection layer/cathode", "substrate/anode/hole transport layer/light emitting layer/electron injection layer/cathode", "substrate/anode/hole transport layer/light emitting layer/electron 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 /Emitting layer/Electron transporting layer/Cathode" or "Substrate/Anode/Emitting layer/Electron injection layer/Cathode".

The organic EL device may further have either or both of an electron blocking layer (electron blocking layer) and a hole blocking layer (hole blocking layer). The electron-blocking layer has a LUMO shallower than the light-emitting layer and a HOMO close to the light-emitting layer or the hole-transporting layer, and is positioned between the light-emitting layer and the hole-transporting layer. Since the electrons remain in the light-emitting layer and do not leak out to the hole transport layer, it is possible to prevent shortening of life due to deterioration of the hole transport layer and decrease in efficiency due to decrease in recombination efficiency. The hole-blocking layer has a HOMO deeper than the light-emitting layer and a LUMO close to the light-emitting layer or hole-transporting layer and is positioned between the light-emitting layer and the electron-transporting layer. Since the holes remain in the light-emitting layer and do not leak out to the electron transport layer, it is possible to prevent shortening of life due to deterioration of the electron transport layer and decrease in efficiency due to decrease in recombination efficiency. The hole injection/transport layer may also serve as the electron blocking layer. The electron injection/transport layer may also serve as the hole blocking layer.

The organic EL device may also have a high T1 layer. A high T1 layer has a higher T1 than the host compound, assisting dopant compound or emitting dopant compound used in the emissive layer and is between the emissive layer and the hole transport layer and/or between the emissive layer and the electron blocking layer. placed. Although the value of T1 energy differs depending on the emission mechanism of the device, it has a higher T1 than the compound used as the host. Having a high T1 layer around the light-emitting layer confines the triplet energy and converts the triplet energy, which normally does not lead to light emission with fluorescent molecules, into singlet energy, resulting in high efficiency. A hole injection/transport layer or an electron blocking layer may also serve as the high T1 layer. The electron injection/transport layer or the hole blocking layer may also serve as the high T1 layer.

The triazine compound of the present invention is preferably used as a material for organic electroluminescence devices. In general, a compound having a donor structure can be used for the hole-transporting host material and the hole-transporting layer in the light-emitting layer, and a compound having an acceptor structure can be used for the electron-transporting layered host material and the electron-transporting layer. A compound having both a donor structure and an acceptor structure can be used for both the hole-transporting layer, the host in the light-emitting layer, and the electron-transporting layer. Donor structures and acceptor structures can be referred to, for example, Advanced Functional Materials 2020, 2008332 and the like. More specifically, the donor structure includes triarylamine structure and carbazole structure, and the acceptor structure includes triazine structure, pyrimidine structure and pyridine structure. The triazine compound according to the present invention can be used as a host material, a hole-transporting layer material, an electron-transporting layer material, and the like in the light-emitting layer.

<Substrate in Organic Electroluminescent Device>
A substrate 101 is a support for the organic EL element 100, and is usually made of quartz, glass, metal, plastic, or the like. The substrate 101 is formed in a plate shape, a film shape, or a sheet shape 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. Of these, glass plates and transparent synthetic resin plates such as polyester, polymethacrylate, polycarbonate and polysulfone are preferred. If it is a glass substrate, soda-lime glass, alkali-free glass, or the like is used, and the thickness should be sufficient to maintain mechanical strength. Further, the substrate 101 may be provided with a gas barrier film such as a dense silicon oxide film on at least one side thereof in order to enhance gas barrier properties. When used, it is preferable to provide a gas barrier film.

<Anode in Organic Electroluminescent Device>
Anode 102 serves to inject holes into light-emitting layer 105 . When at least one of the hole injection layer 103 and the hole transport layer 104 is provided between the anode 102 and the light emitting layer 105, holes are injected into the light emitting layer 105 through these layers. It will be.

Materials for forming the anode 102 include inorganic compounds and organic compounds. Examples of inorganic compounds include metals (aluminum, gold, silver, nickel, palladium, chromium, etc.), metal oxides (indium oxide, tin oxide, indium-tin oxide (ITO), indium-zinc oxide metal (IZO), etc.), metal halides (copper iodide, etc.), copper sulfide, carbon black, ITO glass, Nesa glass, and the like. Examples of organic compounds include polythiophenes such as poly(3-methylthiophene), and conductive polymers such as polypyrrole and polyaniline. In addition, it can be used by appropriately selecting from materials used as anodes of organic EL elements.

<Hole Injection Layer and Hole Transport Layer in Organic Electroluminescent Device>
The hole-injecting layer 103 plays a role of efficiently injecting holes moving from the anode 102 into the light-emitting layer 105 or the hole-transporting layer 104 . The hole transport layer 104 plays a role of efficiently transporting holes injected from the anode 102 or holes injected from the anode 102 through the hole injection layer 103 to the light emitting layer 105 . The hole injection layer 103 and the hole transport layer 104 are each formed by stacking or mixing one or more kinds of hole injection/transport materials. Also, an inorganic salt such as iron (III) chloride may be added to the hole injection/transport material to form the layer.

As a hole-injecting/transporting substance, it is necessary to efficiently inject and transport holes from the positive electrode between electrodes to which an electric field is applied. It is desirable to For this purpose, it is preferable that the ionization potential is low, the hole mobility is high, the stability is excellent, and impurities that act as traps are less likely to occur during manufacture and use. It is also preferable to use the triazine compound of the present invention as a material for the hole transport layer.

Materials for forming the hole injection layer 103 and the hole transport layer 104 include compounds conventionally used as charge transport materials for holes in photoconductive materials, p-type semiconductors, and hole injection layers of organic EL devices. Any compound can be selected and used from known compounds used for the hole 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 (aromatic tertiary Polymers with amino in the main or side chain, 1,1-bis(4-di-p-tolylaminophenyl)cyclohexane, N,N'-diphenyl-N,N'-di(3-methylphenyl)-4 ,4'-diaminobiphenyl, N,N'-diphenyl-N,N'-dinaphthyl-4,4'-diaminobiphenyl, N,N'-diphenyl-N,N'-di(3-methylphenyl)-4 ,4′-diphenyl-1,1′-diamine, N,N′-dinaphthyl-N,N′-diphenyl-4,4′-diphenyl-1,1′-diamine, N ⁴ ,N ⁴ ′ -diphenyl- N ⁴ ,N ^4′ -bis(9-phenyl-9H-carbazol-3-yl)-[1,1′-biphenyl]-4,4′-diamine, N ⁴ ,N ⁴ ,N ^4′ ,N ^{4 '} -tetra[1,1'-biphenyl]-4-yl)-[1,1'-biphenyl]-4,4'-diamine, 4,4',4"-tris(3-methylphenyl(phenyl) triphenylamine derivatives such as amino)triphenylamine, starburst amine derivatives, etc.), stilbene derivatives, phthalocyanine derivatives (metal-free, copper phthalocyanine, etc.), pyrazoline derivatives, hydrazone compounds, benzofuran derivatives, 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. Polycarbonate, styrene derivatives, polyvinylcarbazole, polysilane and the like having the above-mentioned monomers in the side chains are preferable for polymer systems, but a thin film necessary for manufacturing a light-emitting device can be formed and holes can be injected from the anode. Further, the compound is not particularly limited as long as it is a compound capable of transporting holes.

It is also known that the conductivity of organic semiconductors is strongly influenced by their doping. Such an organic semiconductor matrix material is composed of a compound with good electron-donating property or a compound with good electron-accepting property. Strong electron acceptors such as tetracyanoquinonedimethane (TCNQ) or 2,3,5,6-tetrafluorotetracyano-1,4-benzoquinonedimethane (F4TCNQ) are known for doping electron donors. (For example, M. Pfeiffer, A. Beyer, T. Fritz, K. Leo, Appl. Phys. Lett., 73(22), 3202-3204 (1998)” and the literature “J. Pfeiffer, T. Fritz, K. Leo, Appl. Phys. Lett., 73(6), 729-731 (1998)"). They generate so-called holes by an electron transfer process in an electron donating base material (hole transport material). The conductivity of the base material varies considerably depending on the number and mobility of holes. As matrix materials with hole-transport properties, for example, benzidine derivatives (such as TPD) or starburst amine derivatives (such as TDATA), or certain metal phthalocyanines (especially zinc phthalocyanine (ZnPc), etc.) are known ( Japanese Patent Application Laid-Open No. 2005-167175).

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

<Light Emitting Layer in Organic Electroluminescent Device>
The light-emitting layer 105 is a layer that emits light by recombination of holes injected from the anode 102 and electrons injected from the cathode 108 between electrodes to which an electric field is applied. As a material for forming the light-emitting layer 105, any compound (light-emitting compound) that emits light when excited by recombination of holes and electrons can be used. It is preferably a compound that exhibits a strong luminescence (fluorescence) efficiency at . It is also preferable to use the triazine compound of the present invention as a material for a light-emitting layer.

The light-emitting layer may be a single layer or a plurality of layers, each of which is formed of a light-emitting layer material (host material, dopant material). The host material and the dopant material may be of one kind, or may be a combination of a plurality of them. The dopant material may be included entirely or partially in the host material. As a doping method, it can be formed by a co-evaporation method with the host material. It may be filmed.

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

The amount of dopant material to be used varies depending on the type of dopant material, and may be determined according to the properties of the dopant material. A guideline for the amount of the dopant material used is preferably 0.001 to 50% by mass, more preferably 0.05 to 20% by mass, and still more preferably 0.1 to 10% by mass with respect to the total mass of the material for the light-emitting layer. % by mass. The above range is preferable in that, for example, the phenomenon of concentration quenching can be prevented. Moreover, from the viewpoint of durability, it is also preferable that the hydrogen of the dopant material is partially or wholly deuterated.

As the dopant material, an emitting dopant and an assisting dopant material may be used. A thermally activated delayed fluorescence material is preferably used as the assisting dopant material. In an organic electroluminescence device using an assisting dopant material, it is preferable to use a low concentration of the emitting dopant material in order to prevent the concentration quenching phenomenon. A higher concentration of the assisting dopant material is preferable from the viewpoint of the efficiency of the thermally activated delayed fluorescence mechanism. Furthermore, in an organic electroluminescence device using a thermally activated delayed fluorescence assisting dopant material, the efficiency of the thermally activated delayed fluorescence mechanism of the assisting dopant material is lower than the amount of the assisting dopant material used. It is preferred that the amount of emitting dopant material used is low.

When the assisting dopant material is used, the amounts of the host material, the assisting dopant material and the emitting dopant material are 40 to 99% by weight and 59 to 1% by weight, respectively, based on the total weight of the light-emitting layer material. % 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, and 29 to 10% by mass, respectively. % by weight and 5 to 0.05% by weight.

<Host material>
Host materials include condensed ring derivatives such as anthracene and pyrene, bisstyryl anthracene derivatives and distyrylbenzene derivatives, tetraphenylbutadiene derivatives, cyclopentadiene derivatives, fluorene derivatives, benzo Examples include fluorene derivatives, N-phenylcarbazole derivatives, carbazonitrile derivatives and the like.

The triplet energy of the host material is higher than the triplet energy of the dopant having the highest triplet energy in the light-emitting layer or the assisting dopant, from the viewpoint of promoting the generation of TADF in the light-emitting layer without inhibiting it. Specifically, the triplet energy of the host material is preferably 0.01 eV or more, more preferably 0.03 eV or more, and still more preferably 0.1 eV or more. A TADF-active compound may also be used as the host material.

The host material may be of one type or a combination of multiple types. When there are a plurality of combinations, it is preferably a combination of a hole-transporting host material and an electron-transporting host material.

The triazine compound of the present invention can be preferably used as a host material. The triazine compound of the present invention may be used as a single host material, as a hole-transporting host material, or as an electron-transporting host material. The triazine compound of the present invention is preferably used as a single host material or as an electron-transporting host material.

It is also preferable to use a hole-transporting host material for the hole-transporting layer adjacent to the light-emitting layer and 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 device can be obtained. The host material (hole-transporting host material) in the light-emitting layer and the material for the hole-transporting layer may be the same or different. Also, the host material (electron-transporting host material) in the light-emitting layer and the material in the electron-transporting layer may be the same or different.

[Hole-transporting host material (HH)]
Examples of preferred hole-transporting host materials (HH) include the triazine compound of the present invention, compounds represented by formula (HH-1), and compounds having a partial structure represented by formula (HH-1). can give

In formula (HH-1),
Q is >O, >S, or >NA;
one carbon atom next to the carbon atom to which Q is bonded in each of the two phenyls in formula (HH-1) may be bonded to each other with L;
L is a single bond, >O, >S or >C(-A) ₂ ;
A is hydrogen, aryl, heteroaryl, diarylamino, alkyl, cycloalkyl, alkoxy or aryloxy, and two A's in >C(-A) ₂ are joined together to form aryl, heteroaryl, cycloalkyl may be formed.

When the hole-transporting host material contains a structure represented by formula (HH-1) as a partial structure, it may contain one partial structure 1, but preferably contains two or more. When two or more are included, the two or more partial structures may be the same or different. Two or more partial structures may be bonded to each other with a single bond, or may be bonded so as to share any rings contained in the partial structures, and any rings contained in the partial structures may be fused to each other. may be combined in such a way that The substructure may further have substituents selected from aryl, heteroaryl, diarylamino, or aryloxy.

The hole-transporting host material is a compound containing one or more partial structures selected from the group consisting of a condensed polycyclic ring including a triarylamine structure, a carbazole ring, a dibenzofuran ring, a dibenzothiophene ring, and phenoxazine or phenothiazine. is preferably The hole-transporting host material may contain one such partial structure 1, but preferably contains two or more. When two or more are included, the two or more partial structures may be the same or different.

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

Of 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-1-108 are preferred.

[Electron transporting host material (EH)]
Examples of the electron-transporting host material (EH) include the triazine compound of the present invention, the compound represented by the formula (EH-1), and the compound having the partial structure represented by the formula (EH-1). I can give

In formula (EH-1),
each J is independently =C(-A)- or =N-, and at least three Js are =C(-A)-;
Z is -O-, -S-, -C(=O)-, -P(=O)(-A)-, -P(=S)(-A)-, -N(-A)- , -B(-A)- or -S(=O) ₂ -,
J next to the carbon atom to which Z is bonded and A to which Z is bonded may be bonded to each other with L,
L is a single bond, >O, >S or >C(-A) ₂ ;
A is hydrogen, aryl, heteroaryl, diarylamino _, alkyl, cycloalkyl, triarylsilyl, alkoxy or aryloxy; , may form a cycloalkyl,
When all J are =C(-A)-, either one of A or Z has a heteroatom.

For aryl, heteroaryl, diarylamino, alkyl, cycloalkyl, triarylsilyl, alkoxy or aryloxy represented by A in formula (EH-1), refer to the description of A in formula (HH-1). can. For aryl, heteroaryl, and cycloalkyl when two A's in formula (EH-1) are bonded together to form aryl, heteroaryl, and cycloalkyl, refer to the description in formula (HH-1). can.

When the electron-transporting host material contains the structure represented by Formula (EH-1) as a partial structure, it may contain one partial structure, but preferably contains two or more partial structures. When two or more are included, the two or more partial structures may be the same or different. Two or more partial structures may be bonded to each other with a single bond, or may be bonded so as to share any rings contained in the partial structures, and any rings contained in the partial structures may be fused to each other. may be combined in such a way that The substructure may further have substituents selected from aryl, heteroaryl, diarylamino, or aryloxy.

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

Another preferred example of the electron-transporting host material (compound having a partial structure represented by formula (EH-1)) is a polycyclic aromatic compound represented by the following formula (EH-1b), or the following formula ( Multimers of polycyclic aromatic compounds having a plurality of structures represented by EH-1b) can be mentioned.

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; ¹ and X ² cannot both be >C(-R) ₂ ,
Each R in the >N—R and >C(—R) ₂ is independently hydrogen or a substituent selected from the substituent group Z, and the >N—R and >C(—R) ₂ Each R may be independently bonded to at least one of the a-ring, b-ring and c-ring 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- (pyridinic nitrogen ) and at least one is =N- (pyridinic nitrogen);
Each R in the =C(-R)- is independently hydrogen or a substituent selected from the group Z of substituents.
Adjacent groups among R ¹ , R ² , R ³ , R ⁴ and R ⁵ , and R of ═C(—R)— as Y ¹ to Y ⁶ are bonded to form ring a, b An aryl ring or a heteroaryl ring may be formed together with the ring and at least one ring of the c ring, and the formed ring may be substituted with at least one group selected from the substituent group Z.
At least one hydrogen in the compounds and structures represented by formula (EH-1b) may be replaced 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 substituents other than hydrogen, and the others are preferably hydrogen. Preferred substituents are alkyl, aryl optionally substituted with alkyl or heteroaryl, heteroaryl optionally substituted with alkyl or aryl, or diarylamino optionally substituted with alkyl or aryl. At this time, alkyl is preferably alkyl having 1 to 6 carbon atoms (methyl, t-butyl, etc.), aryl is preferably phenyl or biphenyl, and 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.

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

In addition to the above =N- configuration relationship, X ¹ and X ² are preferably >O, and a polycyclic aromatic compound containing a partial structure represented by any of the following formulas is preferred.

In particular, the polycyclic aromatic compound containing the partial structure represented by formula (EH-1b-N1) has a higher E _S1 , a higher E _T1 and a smaller ΔE _S1T1 than the 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 to 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]
The combination of hole-transporting host material and electron-transporting host material is selected according to the HOMO, LUMO and excited triplet energies 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 shallower than the LUMO of the hole-transporting host material. A combination deeper than (HH) is selected, more specifically, a combination in which HOMO (HH) is shallower than HOMO (EH) by 0.10 eV or more and LUMO (HH) is deeper than HOMO (EH) by 0.10 eV or more is preferable, A combination in which HOMO (HH) is 0.20 eV or more shallower than HOMO (EH) and LUMO (HH) is 0.20 eV or more deeper than HOMO (EH) is more preferable, and HOMO (HH) is 0.25 eV or more than HOMO (EH). A shallow combination in which LUMO (HH) is deeper than HOMO (EH) by 0.25 eV or more is more preferable.

The hole-transporting host material and the electron-transporting host material may be a combination that forms an aggregate called an exciplex. It is generally known that an exciplex is likely to form between a material with a relatively deep LUMO level and a material with a shallow HOMO level. Interaction between a hole-transporting host material and an electron-transporting host material, specifically whether or not an exciplex is formed, can be determined by using a single-layer film consisting of only a hole-transporting host material and an electron-transporting host material. Emission spectra (fluorescence and phosphorescence spectra) are measured by forming under the same conditions as those for forming the light-emitting layer, and the obtained emission spectra are the light emitted by the hole-transporting host material and the electron-transporting host material independently. It can be judged by comparing with the spectrum. The spectrum of the mixed film containing the hole-transporting host material and the electron-transporting host material exhibits an emission wavelength different from the spectrum of the film of the hole-transporting host material and the spectrum of the film of the electron-transporting host material. can be determined by Specifically, a difference of 10 nm or more in the peak wavelengths of the spectra may be used as an index.

Specific examples of combinations of hole-transporting host materials and electron-transporting host materials that do not form an exciplex include the following combinations. In order to satisfy the physical property values of HOMO, LUMO and excited triplet energy, the hole-transporting host material has partial structures of carbazole, dibenzofuran, dibenzothiophene, triarylamine, indolocarbazole and benzoxazinophenoxazine. is preferred, compounds having carbazole, dibenzofuran and dibenzothiophene as partial structures are more preferred, and compounds having carbazole as a partial structure are even more preferred. Similarly, in the electron-transporting host material, compounds having pyridine, triazine, phosphine oxide, benzofuropyridine and dibenzooxacillin as partial structures are preferred, and compounds having triazine, phosphine oxide, benzofuropyridine and dibenzooxacillin as partial structures. is more preferred, and triazine-bearing compounds are 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- 1-108, 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- It is preferably selected from the group consisting of 1-130. Preferred examples of combinations include compound HH-1-1 and compound EH-1-22, compound HH-1-1 and compound EH-1-23, compound HH-1-1 and compound EH-1-24, compound HH-1-2 and compound EH-1-22, compound HH-1-2 and compound EH-1-23, compound HH-1-2 and compound EH-1-24, or compound HH-1-1 and compound and EH-1-128.

Specific examples of combinations of hole-transporting host materials and electron-transporting host materials that form an exciplex include the following combinations. Compounds having carbazole, triarylamine, indolocarbazole, and benzoxazinophenoxazine as a partial structure are preferable for the hole-transporting host material in order to satisfy the physical property values of HOMO, LUMO, and excited triplet energy. , triarylamine, indolocarbazole and benzoxazinophenoxazine as partial structures are more preferred, and compounds having triarylamine as a partial structure 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 compounds having triazine, phosphine oxide, benzofuropyridine and dibenzoxacillin as partial structures are more preferred. , phosphine oxides and triazines are more preferred.

More specifically, the hole-transporting host material is HH-1-1, HH-1-2, HH-1-11, HH-1-12, HH-1-17, HH-1-18, Preferably selected from the group consisting of HH-1-23 and HH-1-24, 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 is preferred. Preferred examples of combinations include compound HH-1-1 and compound EH-1-21, compound HH-1-2 and compound EH-1-21, compound HH-1-12 and compound EH-1-117, 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 mentioned.

For other specific combinations of hole-transporting host materials and electron-transporting host materials, see Organic Electronics 66 (2019) 227-24, Advanced. Functional Materials 25 (2015) 361-366. , Advanced Materials 26 (2014) 4730-4734. , ACS Applied Materials and Interfaces 8 (2016) 32984-32991. , ACS Applied Materials and Interfaces 2016, 8, 9806-9810, ACS Applied Materials and Interfaces 2016, 8, 32984-32991, Journal of Materials Chemistry 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.

<Dopant material>
Known compounds can be used as the dopant material, and can be selected from various materials depending on the desired emission color. Specifically, for example, phenanthrene, anthracene, pyrene, tetracene, pentacene, perylene, naphthopyrene, dibenzopyrene, rubrene and chrysene, condensed ring derivatives, benzoxazole derivatives, benzothiazole derivatives, benzimidazole derivatives, benzotriazole derivatives, oxazole derivatives, oxadiazole derivatives, thiazole derivatives, imidazole derivatives, thiadiazole derivatives, triazole derivatives, pyrazoline derivatives, stilbene derivatives, thiophene derivatives, tetraphenylbutadiene derivatives, cyclopentadiene derivatives, bisstyryl derivatives such as bisstyrylanthracene derivatives and distyrylbenzene derivatives (JP-A-1-245087), bisstyrylarylene derivatives (JP-A-2-247278), diazaindacene derivatives, furan derivatives, benzofuran derivatives, phenylisobenzofuran, dimesitylisobenzofuran, di(2-methylphenyl) isobenzofuran derivatives such as isobenzofuran, di(2-trifluoromethylphenyl)isobenzofuran, phenylisobenzofuran, dibenzofuran derivatives, 7-dialkylaminocoumarin derivatives, 7-piperidinocoumarin derivatives, 7-hydroxycoumarin derivatives, 7- Coumarin derivatives such as methoxycoumarin derivatives, 7-acetoxycoumarin derivatives, 3-benzothiazolylcoumarin derivatives, 3-benzimidazolylcoumarin derivatives, 3-benzoxazolylcoumarin derivatives, dicyanomethylenepyran derivatives, dicyanomethylenethiopyran derivatives, polymethine derivatives, cyanine derivatives, oxobenzoanthracene derivatives, xanthene derivatives, rhodamine derivatives, fluorescein derivatives, pyrylium derivatives, carbostyryl derivatives, acridine derivatives, oxazine derivatives, phenylene oxide derivatives, quinacridone derivatives, quinazoline derivatives, pyrrolopyridine derivatives, furopyridine derivatives, 1 , 2,5-thiadiazolopyrene derivatives, pyrromethene derivatives, perinone derivatives, pyrrolopyrrole derivatives, squarylium derivatives, violanthrone derivatives, phenazine derivatives, acridone derivatives, deazaflavin derivatives, fluorene derivatives and benzofluorene derivatives.

As the emitting dopant material, use a boron-containing polycyclic aromatic compound described in WO 2015/102118, WO 2020/162600, paragraphs 0097 to 0269 of JP 2021-077890, etc. is also preferred. A polycyclic aromatic compound having boron atoms may be a phosphor or a TADF material (thermally activated delayed phosphor). The polycyclic aromatic compound having boron atoms is preferably a blue light-emitting compound.

Preferred examples of polycyclic aromatic compounds containing boron 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, and R in >NR is substituted or unsubstituted aryl; substituted or unsubstituted heteroaryl or substituted or unsubstituted alkyl, and R in >NR is bonded to the A ring, B ring, C ring and/or D ring through a linking group or a single bond; may be
R ¹ and R ² are each independently hydrogen, alkyl having 1 to 6 carbon atoms, aryl having 6 to 12 carbon atoms, heteroaryl or diarylamino having 2 to 15 carbon atoms (wherein aryl is C 6 to 12 aryl) and
Z ¹ and Z ² are each independently a substituent selected from the substituent group Z, Z ¹ may be bonded to the A ring through a linking group or a single bond, and Z ² is may be linked to the C ring by a linking group or a single bond, and
At least one hydrogen in the compound represented by formula (12) may be replaced with cyano, halogen or deuterium.

The substituents and Z ¹ and Z ² when the aryl ring or heteroaryl ring in the A ring, B ring, C ring and D ring of formula (12) are substituted are selected from the substituent group Z Substituents can be mentioned.

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 aryl having 6 to 12 carbon atoms, heteroaryl having 2 to 15 carbon atoms, cycloalkyl having 3 to 12 carbon atoms or alkyl having 1 to 6 carbon atoms.
In the compound represented by formula (12), from the viewpoint of high TADF properties, Z ¹ and Z ² are optionally substituted diphenylamino or optionally substituted N-carbazolyl. is preferred, and diphenylamino, which may have a substituent, is more preferred. The diphenylamino which may have a substituent is preferably unsubstituted diphenylamino or diphenylamino having at least one alkyl of 1 to 4 carbon atoms, and is preferably unsubstituted diphenylamino or m Diphenylamino with at least one methyl in the or o-position is more preferred. From the viewpoint of ease of synthesis and emission wavelength, the aryl or heteroaryl rings other than Z ¹ and Z ² in the A, B, C and D rings are unsubstituted or have 1 to 6 carbon atoms. as other substituents, and it is more preferable that Z ¹ and Z ² are not substituted.
Examples of compounds represented by formula (12) are 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 is a ring,
Y ¹¹ , Y ²¹ and 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, and R in >NR is substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl or substituted or unsubstituted alkyl, and R in >NR is a linking group or a single bond to form A ¹¹ ring, A ²¹ ring, A ³¹ ring, B ¹¹ ring, B ²¹ ring, C ¹¹ ring, and/or C ³¹ ring;
At least one hydrogen in the compounds represented by formula (13) and formula (14) may be replaced with cyano, halogen or deuterium.

the aryl or heteroaryl ring in A ¹¹ ring, A ²¹ ring, A ³¹ ring, B ¹¹ ring, B ²¹ ring, C ¹¹ ring, and C ³¹ of formula (13) and formula (14) is substituted Substituents selected from the substituent group Z can be mentioned as the substituents when and Z ¹ and Z ² .

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; , the Rs in the above >NR are each independently aryl having 6 to 12 carbon atoms, heteroaryl having 2 to 15 carbon atoms, cycloalkyl having 3 to 12 carbon atoms or alkyl having 1 to 6 carbon atoms. .

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

<Thermal activated delayed phosphor (assisting dopant)>
A "thermally activated delayed phosphor" absorbs thermal energy to cause reverse intersystem crossing from an excited triplet state to an excited singlet state, and then emits delayed fluorescence by radiative deactivation from the excited singlet state. It means a compound that can However, the term “thermally activated delayed fluorescence” also includes those that pass through a higher triplet in the excitation process from the excited triplet state to the excited singlet state. For example, a paper by Monkman et al., University of Durham (NATURE COMMUNICATIONS, 7:13680, DOI: 10.1038/ncomms13680), a paper by Hosokai et al., National Institute of Advanced Industrial Science and Technology (Hosokai et al., Sci. Adv. 2017;3: e1603282), Kyoto University Sato et al.'s paper (Scientific Reports, 7:4820, DOI: 10.1038/s41598-017-05007-7) and Kyoto University Sato et al. 15, Mechanism of high-efficiency luminescence in organic electroluminescence using DABNA as a luminescent molecule, Graduate School of Engineering, Kyoto University). In the present invention, when the fluorescence lifetime is measured at 300 K for a sample containing the target compound, the target compound is determined to be a "thermally activated delayed phosphor" by observing a slow fluorescent component. Here, the term "slow fluorescence component" refers to a component having a fluorescence lifetime of 0.1 μsec or more. The fluorescence lifetime can be measured using, for example, a fluorescence lifetime measurement device (C11367-01, manufactured by Hamamatsu Photonics K.K.).

In the following description, an organic electroluminescence device using a thermally activated delayed phosphor as an assisting dopant may be referred to as a "TAF device" (TADF Assisting Fluorescence device).
The "host compound" in the TAF element means that the excited singlet energy level obtained from the shoulder on the short wavelength side of the peak of the fluorescence spectrum is higher than the thermally activated delayed phosphor as an assisting dopant and the emitting dopant. It means compound.

FIG. 2 shows an energy level diagram of a light-emitting layer of a TAF device using a general fluorescent dopant as an emitting dopant (ED). In the figure, E (1, G) is the ground state energy level of the host, E (1, S, Sh) is the excited singlet energy level obtained from the shoulder on the short wavelength side of the fluorescence spectrum of the host, and E (1, S, Sh) is the energy level of the host. E (1, T, Sh) is the excited triplet energy level obtained from the shoulder on the short wavelength side of the phosphorescent spectrum, E (2, G) is the ground state energy level of the assisting dopant, E (2, S, Sh) is the excited singlet energy level obtained from the short wavelength shoulder of the fluorescence spectrum, and the excited triplet energy level obtained from the short wavelength shoulder of the phosphorescence spectrum of the assisting dopant is E (2, T, Sh), E (3, G) the energy level of the ground state of the emitting dopant, and E the excited singlet energy level obtained from the short-wavelength shoulder of the fluorescence spectrum of the emitting dopant. (3, S, Sh), E (3, T, Sh) the excited triplet energy level obtained from the shoulder on the short wavelength side of the phosphorescent spectrum of the emitting dopant, h + the hole, e - the electron, Fluorescence resonance energy transfer is referred to as FRET (Fluorescence Resonance Energy Transfer). In the TAF element, when a general fluorescent dopant is used as the emitting dopant (ED), the energy upconverted by the assisting dopant is converted to the excited singlet energy level E (3, S, Sh) of the emitting dopant. It moves and emits light. However, some excited triplet energy E(2, T, Sh) on the assisting dopant is transferred to the excited triplet energy level E(3, T, Sh) of the emitting dopant, or At , an intersystem crossing from the excited singlet energy level E(3,S,Sh) to the excited triplet energy level E(3,T,Sh) occurs, followed by a thermal transition to the ground state E(3,G). effectively inactivated. Some of the energy is not available for light emission due to this pathway, resulting in wasted energy.

On the other hand, in the organic electroluminescence device of this embodiment, the energy transferred from the assisting dopant to the emitting dopant can be efficiently used for light emission, thereby realizing high light emission efficiency. This is presumed to be due to the following light emission mechanism.

FIG. 3 shows a preferable energy relationship in the organic electroluminescence device of this embodiment. In the organic electroluminescence device of this embodiment, the compound having a boron atom as the emitting dopant has a high excited triplet energy level E(3, T, Sh). Therefore, even if the excited singlet energy upconverted at the assisting dopant intersystem crosses to the excited triplet energy level E(3,T,Sh) at the emitting dopant, It is either upconverted or recovered to the excited 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. It is also expected that the separation of the upconversion and luminescence functions into two separate molecules will reduce the high energy residence time and reduce the burden on the compound.

In this embodiment, known host compounds can be used, for example, compounds having at least one of a carbazole ring and a furan ring. It is preferable to use a compound in which at least one of is bound. Specific examples include mCP and mCBP.

The excited triplet energy level E(1, T, Sh) obtained from the shoulder on the short wavelength side of the peak of the phosphorescence spectrum of the host compound promotes the generation of TADF in the light-emitting layer without hindering it. E (2, T, Sh) of the emitting dopant or assisting dopant having the highest triplet energy level in the excited triplet energy level E (2, T, Sh), preferably higher than E (3, T, Sh) Specifically, the excited triplet energy level E (1, T, Sh) of the host compound is higher than E (2, T, Sh) and E (3, T, Sh) by 0.01 eV or more. It is preferably 0.03 eV or more, more preferably 0.1 eV or more. A TADF-active compound may also be used as the host compound.

The thermally activated delayed fluorescent substance (TADF compound) used in the TAF element uses an electron-donating substituent called a donor and an electron-accepting substituent called an acceptor to perform intramolecular HOMO (Highest Occupied Molecular Orbital) and LUMO (Lowest Unoccupied Molecular Orbital), designed to cause efficient reverse intersystem crossing, donor-acceptor thermally activated delayed phosphor (DA type TADF compound ) is preferred.

Here, the term "electron-donating substituent" (donor) as used herein means a substituent and a partial structure in which a HOMO orbital is localized in a thermally activated delayed phosphor molecule. The term “acceptable substituent” (acceptor) means a substituent and a partial structure in which a LUMO orbital is localized in a thermally activated 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 a small exchange interaction between HOMO and LUMO, resulting in ΔE _S1T1 . Its small size results in very fast reverse intersystem crossing velocities. On the other hand, thermally activated delayed fluorophores using donors and acceptors exhibit greater structural relaxation in the excited state (for some molecules, the stable structure differs between the ground state and the excited state, so external stimuli can cause excitation from the ground state). When the conversion occurs, the structure then changes to the stable structure in the excited state), giving a broad emission spectrum, which can reduce color purity when used as a light-emitting material.

As the thermally activated delayed phosphor in the TAF element, for example, a compound in which a donor and an acceptor are bound directly or via a spacer can be used. As the electron-donating group (donor structure) and the electron-accepting group (acceptor structure) used in the thermally activated delayed phosphor of the present invention, for example, see Chemistry of Materials, 2017, 29, 1946-1963. The structures described can be used. Donor structures include carbazole, dimethylcarbazole, di-tert-butylcarbazole, dimethoxycarbazole, tetramethylcarbazole, benzofluorocarbazole, benzothienocarbazole, phenyldihydroindolocarbazole, phenylbicarbazole, bicarbazole, tercarbazole, diphenylcarbazolylamine, tetraphenylcarbazolyldiamine, phenoxazine, dihydrophenazine, phenothiazine, dimethyldihydroacridine, diphenylamine, bis(tert-butylphenyl)amine, N1-(4-(diphenylamino)phenyl)-N4, N4 -diphenylbenzene-1,4-diamine, dimethyltetraphenyldihydroacridinediamine, tetramethyl-dihydro-indenoacridine and diphenyl-dihydrodibenzazacillin. Acceptor structures include sulfonyldibenzene, benzophenone, phenylenebis(phenylmethanone), benzonitrile, isonicotinonitrile, phthalonitrile, isophthalonitrile, paraphthalonitrile, benzenetricarbonitrile, triazole, oxazole, and thiadiazole. , benzothiazole, benzobis(thiazole), benzoxazole, benzobis(oxazole), quinoline, benzimidazole, dibenzoquinoxaline, heptaazaphenalene, thioxanthone dioxide, dimethylanthracenone, anthracenedione, 5H-cyclopenta[1,2-b : 5,4-b']dipyridine, fluorenedicarbonitrile, triphenyltriazine, pyrazinedicarbonitrile, pyrimidine, phenylpyrimidine, methylpyrimidine, pyridinedicarbonitrile, dibenzoquinoxalinedicarbonitrile, bis(phenylsulfonyl)benzene, Dimethylthioxanthene dioxide, thianthrenetetroxide 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, isophthalonitrile, diphenylsulfone, triazole, A compound containing at least one selected from oxadiazole, thiadiazole and benzophenone is preferred.

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

<Phosphorescent material (assisting dopant)>
A phosphorescent material may be used as an assisting dopant in the light-emitting layer. Phosphorescent materials utilize intramolecular spin-orbital interactions (heavy atom effect) by metal atoms to obtain emission from triplets. As such a phosphorescent material, for example, a luminescent metal complex can be used. Examples of the luminescent metal complex include compounds represented by the following formulas (B-1) and (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; XY" is 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 "WXYZ" is a tetradentate ligand.
In formula (B-1), M is preferably Ir and n is preferably 3 from the viewpoint of efficiency and life.
In formula (B-2), M is preferably Pt from the viewpoint of efficiency and life.
The ligand (XY) in formula (B-1) has at least one ligand selected from the group consisting of: The ligand (WXYZ) in formula (B-2) has as a part thereof at least one ligand selected from the group consisting of the following.

During the ceremony,
--- is bound to 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 , SiRe _{R f} , or GeRe _{R f} each aromatic carbon C-H in the ring may be independently substituted with N,
R _e and R _f may optionally be fused or joined to form a ring;
R _a , R _b , R _c , and R _d are each independently unsubstituted or optionally substituted from 1 to the maximum possible 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 combinations thereof;
However, any two adjacent substituents in R _a , R _b , R _c , and R _d may be fused or joined to form a ring or to form a multidentate ligand.

Examples of compounds represented by formula (B-1) include Ir(ppy) ₃ , Ir(ppy) ₂ (acac), Ir(mppy) ₃ , Ir(PPy) ₂ (m-bppy), BtpIr ( acac), Ir(btp) ₂ (acac), Ir(2-phq) ₃ , Hex-Ir(phq) ₃ , Ir(fbi) ₂ (acac), 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(FIq) ₂ (acac), Ru(dtb-bpy) ₃ 2(PF ₆ ), Ir(2-phq) ₃ , Ir(BT) ₂ (acac), Ir(DMP) ₃ , Ir(Mphq) ₃ IR(phq) ₂ tpy, fac -Ir(ppy) _2Pc , Ir(dp) _PQ2 , Ir(Dpm)(Piq) ₂ , Hex-Ir(piq) ₂ (acac), Hex-Ir(piq) ₃ , Ir(dmpq) ₃ , Ir (dmpq) ₂ (acac), FPQIrpic, and the like.

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

In addition, JP 2006-089398, JP 2006-080419, JP 2005-298483, JP 2005-097263, and JP 2004-111379, US 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 - An The platinum complexes described in Outlook On the Empirical Features and Its Recent Technological Advancements, Chapter 5 may also be used.

<Electron Injection Layer and Electron Transport Layer in Organic Electroluminescent Device>
The electron injection layer 107 plays a role of efficiently injecting electrons moving from the cathode 108 into the light emitting layer 105 or the electron transport layer 106 . The electron transport layer 106 plays a role of efficiently transporting 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 stacking and mixing one or more electron transport/injection materials, or by a mixture of an electron transport/injection material and a polymer binder.

The electron injection/transport layer is a layer in which electrons are injected from the cathode and is responsible for transporting the electrons. It is desirable that the electron injection efficiency is high and the injected electrons are efficiently transported. For this purpose, it is preferable to use a substance that has high electron affinity, high electron mobility, excellent stability, and does not easily generate trapping impurities during production and use. However, when considering the transport balance of holes and electrons, if the function mainly plays the role of efficiently preventing holes from the anode from flowing to the cathode side without recombination, the electron transport capacity is not so high. Even if it is not high, the effect of improving the luminous efficiency is equivalent to that of a material with a high electron transport ability. Therefore, the electron injection/transport layer in this embodiment may also have the function of a layer capable of efficiently blocking the movement of holes.

Materials (electron transport materials) forming the electron transport layer 106 or the electron injection layer 107 include compounds conventionally used as electron transport compounds in photoconductive materials, and those used in the electron injection layer and electron transport layer of organic EL elements. It can be used by arbitrarily selecting from among the known compounds that are known.
It is also preferable to use the triazine compound of the present invention as a material for an electron transport layer.

Materials used for the electron transport layer or the electron injection layer include compounds composed of aromatic rings or heteroaromatic rings composed of one or more atoms selected from carbon, hydrogen, oxygen, sulfur, silicon and phosphorus, It preferably contains at least one selected from pyrrole derivatives, condensed ring derivatives thereof, and metal complexes having electron-accepting nitrogen. Specifically, condensed ring aromatic ring derivatives such as naphthalene and anthracene, styryl aromatic ring derivatives typified 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 metal complexes having electron-accepting nitrogen include hydroxyazole complexes such as hydroxyphenyloxazole complexes, azomethine complexes, tropolone metal complexes, flavonol metal complexes and benzoquinoline metal complexes. These materials may be used alone, but may be used in combination with different materials.

Specific examples of other electron transfer compounds include pyridine derivatives, naphthalene derivatives, anthracene derivatives, phenanthroline derivatives, perinone derivatives, coumarin derivatives, naphthalimide derivatives, anthraquinone derivatives, diphenoquinone derivatives, diphenylquinone derivatives, perylene derivatives, and 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 oxine derivatives, quinolinol metal complexes, quinoxaline derivatives, polymers of quinoxaline derivatives, benzazole compounds, gallium complexes, pyrazole derivatives, perfluorinated phenylene derivatives, triazine derivatives, pyrazine derivatives, benzoquinoline derivatives (2,2'-bis(benzo[h]quinolin-2-yl)-9,9'-spirobifluorene, etc.), imidazopyridine derivatives, borane derivatives, benzimidazole derivatives (tris(N-phenylbenzimidazole- 2-yl)benzene, etc.), benzoxazole derivatives, benzothiazole derivatives, quinoline derivatives, oligopyridine derivatives such as terpyridine, bipyridine derivatives, terpyridine derivatives (1,3-bis(2,2′:6′,2″-terpyridine -4′-yl)benzene, etc.), naphthyridine derivatives (bis(1-naphthyl)-4-(1,8-naphthyridin-2-yl)phenylphosphine oxide, etc.), aldazine derivatives, carbazole derivatives, indole derivatives, phosphine oxides derivatives, bis-styryl derivatives and the like.

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, flavonol metal complexes, benzoquinoline metal complexes, and the like. can give.

Although the above materials can be used alone, they may be used in combination with different materials.

Borane derivatives, pyridine derivatives, fluoranthene derivatives, BO-based derivatives, anthracene derivatives, benzofluorene derivatives, phosphine oxide derivatives, pyrimidine derivatives, arylnitrile derivatives, triazine derivatives, benzimidazole derivatives, phenanthroline derivatives, and quinolinol derivatives, among the materials mentioned above. Metal complexes are preferred.

The electron-transporting layer or electron-injecting layer may further contain a substance capable of reducing the material forming the electron-transporting layer or electron-injecting layer. Various substances are used as the reducing substance as long as they have a certain reducing property. from the group consisting of earth metal oxides, alkaline earth metal halides, rare earth metal oxides, rare earth metal halides, alkali metal organic complexes, alkaline earth metal organic complexes and rare earth metal organic complexes At least one selected can be preferably used.

Preferred reducing substances include alkali metals such as Na (work function 2.36 eV), K (2.28 eV), Rb (2.16 eV) or Cs (1.95 eV), and Ca (2.95 eV). 9 eV), Sr (2.0 to 2.5 eV) or Ba (2.52 eV), and materials with a work function of 2.9 eV or less are particularly preferred. Among these, more preferred reducing substances are alkali metals of K, Rb or Cs, more preferably Rb or Cs, and most preferably Cs. These alkali metals have a particularly high reducing ability, and by adding a relatively small amount to the material forming the electron transport layer or the electron injection layer, it is possible to improve the emission luminance and extend the life of the organic EL device. As a reducing substance having a work function of 2.9 eV or less, a combination of two or more of these alkali metals is also preferable, particularly a combination containing Cs, such as Cs and Na, Cs and K, Cs and Rb, or A combination of Cs, Na and K is preferred. By containing Cs, the reduction ability can be efficiently exhibited, and by addition to the material forming the electron transport layer or the electron injection layer, the luminance of the organic EL device can be improved and the life of the device can be extended.

<Cathode in Organic Electroluminescent Device>
The cathode 108 serves to inject electrons into the light emitting layer 105 via the electron injection layer 107 and the electron transport layer 106 .

The material for forming the cathode 108 is not particularly limited as long as it can efficiently inject electrons into the organic layer, but the same material as the material for forming the anode 102 can be used. Metals such as tin, indium, calcium, aluminum, silver, copper, nickel, chromium, gold, platinum, iron, zinc, lithium, sodium, potassium, cesium and magnesium or their alloys (magnesium-silver alloys, magnesium - indium alloys, aluminum-lithium alloys such as lithium fluoride/aluminum, etc.). Lithium, sodium, potassium, cesium, calcium, magnesium, or alloys containing these low work function metals are effective in increasing the electron injection efficiency and improving the device characteristics. However, these low work function metals are generally unstable in the atmosphere. In order to improve this point, for example, a method of doping an organic layer with a small amount of lithium, cesium, or magnesium to use a highly stable electrode is known. Other dopants can also be inorganic salts such as lithium fluoride, cesium fluoride, lithium oxide and cesium oxide. However, it is not limited to these.

Furthermore, for electrode protection, metals such as platinum, gold, silver, copper, iron, tin, aluminum and indium, or alloys using these metals, inorganic substances such as silica, titania and silicon nitride, polyvinyl alcohol, vinyl chloride A preferable example is lamination of a hydrocarbon-based polymer compound or the like. The method of manufacturing these electrodes is not particularly limited, either by resistance heating, electron beam deposition, sputtering, ion plating, coating, or the like, as long as it can provide electrical continuity.

<Method for producing organic electroluminescent element>
Each layer constituting the organic EL element is formed by depositing a material to constitute each layer into a thin film by a method such as vapor deposition, resistance heating vapor deposition, electron beam vapor deposition, sputtering, molecular lamination, printing, spin coating, casting, or coating. can be formed by The thickness of each layer thus formed is not particularly limited and can be appropriately set according to the properties 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 film thickness measuring device or the like. When thin film formation is performed using a vapor deposition method, the vapor deposition conditions vary depending on the type of material, the desired crystal structure and association structure of the film, and the like. Deposition conditions are generally boat heating temperature +50 to +400°C, degree of vacuum 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 preferable to set appropriately within the range.

When a DC voltage is applied to the organic EL device thus obtained, it is sufficient to apply the positive polarity to the positive electrode and the negative polarity to the negative electrode. Light emission can be observed from the side (anode or cathode, and both). Moreover, this organic EL element emits light even when a pulse current or an alternating current is applied. Note that the AC waveform to be applied may be arbitrary.

Next, as an example of a method for producing an organic EL device, an organic EL device comprising an anode/hole injection layer/hole transport layer/light-emitting layer comprising a host material and a dopant material/electron transport layer/electron injection layer/cathode. The manufacturing method of is explained.

<Deposition method>
A thin film of an anode material is formed on an appropriate substrate by a vapor deposition method or the like to prepare an anode, and then a thin film of a hole injection layer and a hole transport layer is formed on the anode. A host material and a dopant material are co-deposited thereon to form a thin film to form a light-emitting layer, an electron-transporting layer and an electron-injecting layer are formed on the light-emitting layer, and a thin film of a cathode material is formed by vapor deposition or the like. A target organic EL element is obtained by forming the material and using it as a cathode. In the production of the organic EL element described above, the order of production can be reversed to produce the cathode, the electron injection layer, the electron transport layer, the light emitting layer, the hole transport layer, the hole injection layer, and the anode in this order. is.

<Wet film formation method>
The wet film-forming method is carried out by preparing a low-molecular-weight compound capable of forming each organic layer of an organic EL element as a liquid composition for forming an organic layer, and using this. In the absence of a suitable organic solvent for dissolving this low-molecular-weight compound, a reactive compound obtained by substituting a reactive substituent on the low-molecular-weight compound can be used together with other monomers or main-chain polymers that have a solubility function. A composition for forming an organic layer may be prepared from a molecularized polymer compound or the like.

In the wet film-forming method, a coating film is generally formed through a coating step of applying an organic layer-forming composition to a substrate and a drying step of removing the solvent from the applied organic layer-forming composition. In the case where the polymer compound has a crosslinkable substituent (also referred to as a crosslinkable polymer compound), the drying step further crosslinks the polymer to form a crosslinked polymer. Depending on the difference in the coating process, the method using a spin coater is called the spin coating method, the method using a slit coater is the slit coating method, the method using a plate is gravure, offset, reverse offset, flexographic printing, and the method using an inkjet printer is the inkjet method. , the method of spraying in the form of a 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 multiple times using different methods and conditions. Also, different methods may be used in combination, such as firing under reduced pressure.

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

On the other hand, lamination may be difficult with the wet film-forming method when compared with the vacuum deposition method. When preparing a laminated film using a wet film formation method, it is necessary to prevent the dissolution of the lower layer by the composition of the upper layer. solvent) is used. However, even with those techniques, it can be difficult to use wet deposition methods for all film applications.

Therefore, in general, a method is adopted in which only some layers are formed by a wet film formation method, and the remaining layers are formed by a vacuum vapor deposition method.

For example, the procedure for partially applying the wet film formation method to fabricate an organic EL element is shown below.
(Procedure 1) Film formation of anode by vacuum deposition method (Procedure 2) Film formation of hole injection layer forming composition containing hole injection layer material by wet film formation method (Procedure 3) Hole transport layer material Film formation by a wet film formation method of a composition for forming a hole transport layer containing a host material and a dopant material by a wet film formation method (Procedure 5) Electron transport layer (Procedure 6) Electron injection layer film formation by vacuum vapor deposition method (Procedure 7) Cathode film formation by vacuum vapor deposition method Through this procedure, anode/hole injection layer/hole transport An organic EL device comprising a layer/host material and dopant material comprising a luminescent layer/electron-transporting layer/electron-injecting layer/cathode is obtained.
Of course, the electron-transporting layer and the electron-injecting layer may also be formed by a wet film-forming method using a layer-forming composition containing an electron-transporting layer material and an electron-injecting layer material, respectively. In this case, 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 reverse to the above procedure.

<Other film forming methods>
A laser thermal lithography method (LITI) can be used to form a film from the composition for forming an organic layer. LITI is a method in which a compound adhered to a base material is thermally vapor-deposited with a laser, and an organic layer-forming composition can be used as the material applied to the base material.

<Optional step>
Appropriate treatment steps, washing steps, and drying steps may be appropriately added before and after each step of film formation. Examples of treatment steps include exposure treatment, plasma surface treatment, ultrasonic treatment, ozone treatment, cleaning treatment using an appropriate solvent, and heat treatment. Furthermore, a series of steps for fabricating a bank can also be mentioned.

A photolithography technique can be used to fabricate the bank. Positive resist materials and negative resist materials can be used as bank materials that can be used in photolithography. In addition, patternable printing methods such as ink jet method, gravure offset printing, reverse offset printing, and screen printing can also be used. In that case, a permanent resist material can also be used.

<Organic Layer Forming Composition Used in Wet Film Forming Method>
The composition for forming an organic layer is obtained by dissolving a low-molecular-weight compound capable of forming each organic layer of an organic EL element or a high-molecular-weight compound obtained by polymerizing the low-molecular-weight compound in an organic solvent. For example, the composition for forming a light-emitting layer includes at least one dopant material polycyclic aromatic compound (or polymer compound thereof) as a first component, at least one host material as a second component, and a third It contains at least one organic solvent as a component. The first component functions as a dopant component for the light-emitting layer obtained from the composition, and the second component functions as a host component for the light-emitting layer. The third component functions as a solvent that dissolves the first and second components in the composition, and provides a smooth and uniform surface profile during application due to the controlled evaporation rate of the third component itself.

<Organic solvent>
The composition for forming an organic layer contains at least one kind of organic solvent. By controlling the evaporation rate of the organic solvent during film formation, it is possible to control and improve the film formability, the presence or absence of defects in the coating film, the surface roughness, and the smoothness. In addition, when forming a film using an inkjet method, the stability of the meniscus at the pinhole of the inkjet head can be controlled, and the ejection property can be controlled and improved. In addition, by controlling the drying rate of the film and the orientation of the derivative molecules, the electrical properties, luminescence properties, efficiency and life of the organic EL device having an organic layer obtained from the composition for forming an organic layer are improved. can be done.

After film formation, the organic solvent is removed from the coating film by a drying process such as vacuum, reduced pressure, or heating. When heating is performed, it is preferable to perform the heating at a temperature not higher than the glass transition temperature (Tg) of at least one of the solutes + 30°C from the viewpoint of improving coating film properties. From the viewpoint of reducing residual solvent, it is preferable to heat at least one of the solutes at a glass transition point (Tg) of −30° C. or higher. Even if the heating temperature is lower than the boiling point of the organic solvent, the organic solvent is sufficiently removed because the film is thin. In addition, drying may be performed multiple times at different temperatures, and multiple drying methods may be used in combination.

(2) Specific Examples of Organic Solvents Examples of organic solvents used in the composition for forming an organic layer include alkylbenzene solvents, phenyl ether solvents, alkyl ether solvents, cyclic ketone solvents, aliphatic ketone solvents, and monocyclic solvents. Examples include, but are not limited to, ketone solvents, solvents having a diester skeleton, fluorine-containing solvents, and the like. Also, the solvents may be used singly or in combination.

<Optional component>
The composition for forming an organic layer may contain optional components as long as the properties thereof are not impaired. Optional components include binders and surfactants.

<Composition and physical properties of composition for forming organic layer>
The content of each component in the organic layer-forming composition is obtained from the good solubility, storage stability, and film-forming properties of each component in the organic layer-forming composition, and the organic layer-forming composition. Good film quality of the coating film, good dischargeability when using the inkjet method, good electrical properties, luminescence properties, efficiency and life of the organic EL element having an organic layer produced using the composition It is determined in consideration of the viewpoint of

The composition for forming an organic layer can be produced by appropriately selecting the above-described components by stirring, mixing, heating, cooling, dissolving, dispersing, and the like by a known method. After preparation, filtration, degassing (also referred to as degassing), ion exchange treatment, inert gas replacement/encapsulation treatment, and the like may be appropriately selected and performed.

<Application example of organic electroluminescence element>
The present invention can also be applied to a display device having an organic EL element, a lighting device having an organic EL element, or the like.
A display device or a 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 and a known driving device, and can be manufactured by direct current driving, pulse driving, alternating current driving, or the like. It can be driven by appropriately using a known driving method.

Examples of display devices include panel displays such as color flat panel displays, and flexible displays such as flexible color organic electroluminescence (EL) displays (for example, JP-A-10-335066 and JP-A-2003-321546). (See Japanese Patent Laid-Open No. 2004-281086, etc.). Moreover, the display method of the display includes, for example, a matrix method and a segment method. Note that matrix display and segment display may coexist in the same panel.

In the matrix, pixels for display are arranged in a two-dimensional pattern such as a grid pattern or a mosaic pattern, and a set of pixels displays characters and images. The shape and size of the pixels are determined by the application. For example, in the image and character display of personal computers, monitors, and televisions, square pixels with a side of 300 μm or less are usually used, and in the case of a large display such as a display panel, a pixel with a side of mm order is used. become. In the case of monochrome display, pixels of the same color may be arranged, but in the case of color display, pixels of red, green, and blue are displayed side by side. In this case, there are typically delta type and stripe type. As a method for driving this matrix, either a line-sequential driving method or an active matrix method may be used. Although the line-sequential drive has the advantage of being simpler in structure, the active matrix may be superior in terms of operating characteristics.

In the segment method (type), a pattern is formed so as to display predetermined information, and a predetermined area is illuminated. Examples include time and temperature displays in digital clocks and thermometers, operating state displays in audio equipment and electromagnetic cookers, and panel displays in automobiles.

Examples of lighting devices include lighting devices such as indoor lighting, backlights for liquid crystal display devices, and the like (for example, JP-A-2003-257621, JP-A-2003-277741, JP-A-2004-119211, and the like). etc.). Backlights are mainly used for the purpose of improving the visibility of display devices that do not emit light by themselves, and are used in liquid crystal display devices, clocks, audio devices, automobile panels, display boards, signs, and the like. In particular, as a liquid crystal display device, especially a backlight for a personal computer, for which thinning is a problem, it is difficult to reduce the thickness of the conventional method because it is made of a fluorescent lamp or a light guide plate. The backlight using the light-emitting element according to 1 is characterized by its thinness and light weight.

3-2. Other Organic Devices The triazine compound according to the present invention can be used for the production of organic field effect transistors, organic thin film solar cells, etc., in addition to the organic electroluminescence devices described above.

EXAMPLES The present invention will be described in more detail with reference to examples below, but the present invention is not limited to these. First, synthesis examples of triazine compounds are described below.

Synthesis example (1)
Compound (1-1): 9,9′-(6-(9-(4,6-diphenyl-1,3,5-triazin-2-yl)-9H-carbazol-3-yl)-1,3 Synthesis of ,5-triazine-2,4-diyl)bis(9H-carbazole)

Synthesis of 9,9′-(6-chloro-1,3,5-triazine-2,4-diyl)bis(9H-carbazole) (1-a)

Under a nitrogen atmosphere, sodium hydride (6.5 g, 274 mmol) was added portionwise to a solution of 9H-carbazole (45.7 g, 274 mmol) in tetrahydrofuran (1000 ml) and stirred at room temperature for 30 minutes. After that, a solution of cyanuric chloride (25 g, 137 mmol) in tetrahydrofuran (500 ml) was added dropwise, and the mixture was stirred at room temperature for 3 hours. After completion of the reaction, water (1000 ml) was added and the crystals formed were filtered and washed with water, acetone and methanol. The resulting crystals were slurry-washed twice with toluene (100 ml), and the filtrates were combined and concentrated. The obtained crystals are slurry-washed twice with Solmix and then dried to give 9,9′-(6-chloro-1,3,5-triazine-2,4-diyl)bis(9H-carbazole). (34.1 g, 76.7 mmol) was obtained.

Synthesis of 3-bromo-9-(4,6-diphenyl-1,3,5-triazin-2-yl)-9H-carbazole (1-b)

To a solution of 3-bromo-9H-carbazole (10.2 g, 41.6 mmol) in tetrahydrofuran (100 ml) under nitrogen atmosphere, sodium hydride (0.41 g, 45.0 mmol) was added portionwise and the mixture was stirred at room temperature for 30 minutes. Stirred. After that, a solution of 2-chloro-4,6-diphenyl-1,3,5-triazine (10.0 g, 37.4 mmol) in tetrahydrofuran (50 ml) was added dropwise and stirred at room temperature for 3 hours. After completion of the reaction, water (100 ml) was added and crystals formed were filtered and washed with water, acetone and methanol. The crystals obtained were dried to give 3-bromo-9-(4,6-diphenyl-1,3,5-triazin-2-yl)-9H-carbazole (19.6 g, 41.2 mmol).

9-(4,6-diphenyl-1,3,5-triazin-2-yl)-3-(4,4,5,5-tetramethyl-1,3,2-dioxaboran-2-yl)-9H - Synthesis of carbazole (1-1c)

Under nitrogen atmosphere, 3-bromo-9-(4,6-diphenyl-1,3,5-triazin-2-yl)-9H-carbazole (10.0 g, 21.0 mmol), 4,4,4′, 4′,5,5,5′,5′-octamethyl-2,2′-bi(1,3,2-dioxaborolane) (5.6 g, 22.0 mmol), potassium acetate (3.4 g, 42.0 mmol) ), palladium acetate (0.094 g, 0.42 mmol), SPhos (2-dicyclohexylphosphino-2,6-biphenyl) (0.04 g, 0.84 mmol) and cyclopentyl methyl ether (100 ml). It was heated to reflux for 1 hour. After completion of the reaction, the reaction solution was cooled to room temperature, water (100 ml) was added, and crystals formed were filtered. The obtained crystals are washed with water, acetone and methanol and then dried to give 9-(4,6-diphenyl-1,3,5-triazin-2-yl)-3-(4,4, 5,5-tetramethyl-1,3,2-dioxaboran-2-yl)-9H-carbazole (8.7 g, 16.6 mmol) was obtained.

9,9′-(6-(9-(4,6-diphenyl-1,3,5-triazin-2-yl)-9H-carbazol-3-yl)-1,3,5-triazine-2, Synthesis of 4-diyl)bis(9H-carbazole) (1-1)

Under nitrogen atmosphere, 9-(4,6-diphenyl-1,3,5-triazin-2-yl)-3-(4,4,5,5-tetramethyl-1,3,2-dioxaborane-2- yl)-9H-carbazole (2.0 g, 4.4 mmol), 9,9′-(6-chloro-1,3,5-triazine-2,4-diyl)bis(9H-carbazole) (2.3 g , 4.4 mmol), potassium carbonate (1.8 g, 13.1 mmol), tetrakistriphenylphosphine palladium (0.51 g, 0.44 mmol), tetrabutylammonium bromide (0.42 g, 1.31 mmol) and dimethoxyethane ( 100 ml) and water (10 ml) were heated to reflux for 8 hours. After completion of the reaction, the reaction solution was cooled to room temperature, water (100 ml) was added, and crystals formed were filtered. The obtained crystals were washed with water, acetone and methanol, and then slurry-washed twice with tetrahydrofuran (50 ml). After drying the crystals, purification by sublimation (380° C.) gives 9,9′-(6-(9-(4,6-diphenyl-1,3,5-triazin-2-yl)-9H-carbazole- 3-yl)-1,3,5-triazine-2,4-diyl)bis(9H-carbazole) (0.26 g, 0.32 mmol) was obtained.

The structure of the obtained compound was confirmed by NMR measurement and LC-MS.
¹ H-NMR (500 MHz, CDCl ₃ ): δ=7.45-7.62 (m, 9H), 7.65-7.75 (m, 7H), 8.15 (d, 4H), 8. 28 (d, 1H), 8.82 (d, 4H), 9.02 (d, 1H), 9.15 (d, 4H), 9.22 (d, 1H), 9.38 (d, 1H) ), 9.52(s, 1H).
LC-MS: m/z = 808 [M+H].

Synthesis example (2)
Compound (1-21): 9,9′-(6-(3-(4,6-diphenyl-1,3,5-triazin-2-yl)-9H-carbazol-9-yl)-1,3 Synthesis of ,5-triazine-2,4-diyl)bis(9H-carbazole)

Synthesis of 9,9′-(6-(3-bromo-9H-carbazol-9-yl)-1,3,5-triazine-2,4-diyl)bis(9H-carbazole) (1-c)

To a solution of 3-bromo-9H-carbazole (3.0 g, 12.4 mmol) in tetrahydrofuran (100 ml) under nitrogen atmosphere, sodium hydride (0.32 g, 13.5 mmol) was added portionwise and the mixture was stirred at room temperature for 30 minutes. Stirred. After that, a solution of 9,9′-(6-chloro-1,3,5-triazine-2,4-diyl)bis(9H-carbazole) (5.0 g, 11.2 mmol) in tetrahydrofuran (50 ml) was added dropwise. , and stirred at room temperature for 3 hours. After completion of the reaction, water (100 ml) was added and crystals formed were filtered and washed with water, acetone and methanol. The obtained crystals are dried to give 9,9′-(6-(3-bromo-9H-carbazol-9-yl)-1,3,5-triazine-2,4-diyl)bis(9H-carbazole) (7.1 g, 10.9 mmol) was obtained.

9,9′-(6-(3-(4,4,5,5-tetramethyl-1,3,2-dioxaboran-2-yl)-9H-carbazol-9-yl)-1,3,5 - Synthesis of triazine-2,4-diyl)bis(9H-carbazole) (1-d)

Under nitrogen atmosphere, 9,9′-(6-(3-bromo-9H-carbazol-9-yl)-1,3,5-triazine-2,4-diyl)bis(9H-carbazole) (10.0 g) , 15.3 mmol), 4,4,4′,4′,5,5,5′,5′-octamethyl-2,2′-bi(1,3,2-dioxaborolane) (4.1 g, 16. 0 mmol), potassium acetate (2.5 g, 30.7 mmol), palladium acetate (0.069 g, 0.31 mmol), SPhos (2-dicyclohexylphosphino-2,6-biphenyl) (0.03 g, 0.61 mmol) and cyclopentyl methyl ether (100 ml) were heated to reflux for 8 hours. After completion of the reaction, the reaction solution was cooled to room temperature, water (100 ml) was added, and crystals formed were filtered. The obtained crystals are washed with water, acetone and methanol and then dried to give 9,9′-(6-(3-(4,4,5,5-tetramethyl-1,3,2- Dioxaboran-2-yl)-9H-carbazol-9-yl)-1,3,5-triazine-2,4-diyl)bis(9H-carbazole) (7.5 g, 10.6 mmol) was obtained.

9,9′-(6-(3-(4,6-diphenyl-1,3,5-triazin-2-yl)-9H-carbazol-9-yl)-1,3,5-triazine-2, Synthesis of 4-diyl)bis(9H-carbazole) (1-21)

Under a nitrogen atmosphere, 9,9′-(6-(3-(4,4,5,5-tetramethyl-1,3,2-dioxaboran-2-yl)-9H-carbazol-9-yl)-1 ,3,5-triazine-2,4-diyl)bis(9H-carbazole) (2.0 g, 2.8 mmol), 2-chloro-4,6-diphenyl-1,3,5-triazine (0.76 g , 2.8 mmol), potassium carbonate (1.1 g, 8.3 mmol), tetrakistriphenylphosphine palladium (0.32 g, 0.28 mmol), tetrabutylammonium bromide (0.27 g, 0.83 mmol) and dimethoxyethane ( 50 ml) and water (5 ml) were heated to reflux for 8 hours. After completion of the reaction, the reaction solution was cooled to room temperature, water (50 ml) was added, and crystals formed were filtered. The obtained crystals were washed with water, acetone and methanol, and then slurry-washed twice with tetrahydrofuran (50 ml). After drying the crystals, purification by sublimation (380° C.) gives 9,9′-(6-(3-(4,6-diphenyl-1,3,5-triazin-2-yl)-9H-carbazole- 9-yl)-1,3,5-triazine-2,4-diyl)bis(9H-carbazole) (0.1 g, 0.12 mmol) was obtained.

The structure of the obtained compound was confirmed by NMR measurement and LC-MS.
¹ H-NMR (500 MHz, CDCl ₃ ): δ=7.45-7.56 (m, 10H), 7.60-7.66 (m, 6H), 8.15 (d, 4H), 8. 38 (dd, 1H), 8.85 (d, 4H), 8.94 (d, 1H), 9.04 (d, 1H), 9.05 (d, 4H), 9.16 (d, 1H) ), 9.55(s, 1H).
LC-MS: m/z = 808 [M+H].

Synthesis example (3)
Compound (1-11): 9,9′,9″,9′″-((9H-carbazole-3,9-diyl)bis(1,3,5-triazine-6,2,4-triyl )) Synthesis of tetrakis(9H-carbazole)

9,9′,9″,9′″-((9H-carbazole-3,9-diyl)bis(1,3,5-triazine-6,2,4-triyl))tetrakis(9H-carbazole ) (1-11).

In the same manner as in Synthesis Examples (1) and (2), 9,9′-(6-(3-(4,4,5,5-tetramethyl-1,3,2-dioxaboran-2-yl)- 9H-carbazol-9-yl)-1,3,5-triazine-2,4-diyl)bis(9H-carbazole) (2.0 g, 2.8 mmol), and 9,9′-(6-chloro- 9,9′,9″,9′″-((9H-carbazole -3,9-diyl)bis(1,3,5-triazine-6,2,4-triyl))tetrakis(9H-carbazole) (0.1 g, 1.0 mmol).

The structure of the obtained compound was confirmed by NMR measurement and LC-MS.
¹ H-NMR (500 MHz, CDCl ₃ ): δ=7.45-7.62 (m, 8H), 7.61-7.75 (m, 5H), 8.15 (d, 4H), 8. 28-8.38 (m, 2H), 8.80-8.87 (m, 8H), 8.93-9.06 (m, 10H), 9.15-9.22 (m, 1H), 9.55 (s, 1H).
LC-MS: m/z = 986 [M+H].

Other compounds of the present invention can be synthesized by methods according to the synthesis examples described above by appropriately changing the starting compounds.

Next, preparation and evaluation of the organic EL device will be described. However, application of the compound of the present invention is not limited to the examples shown below, and the film thickness and constituent materials of each layer can be appropriately changed depending on the basic physical properties of the compound used.

<Comparative Example 1-1>
A 26 mm×28 mm×0.7 mm glass substrate (manufactured by OptoScience Co., Ltd.) was used as a transparent support substrate, on which an ITO film having a thickness of 200 nm was formed by sputtering and polished to 50 nm. This transparent support substrate was fixed to a substrate holder of a commercially available vapor deposition apparatus (manufactured by Showa Shinku Co., Ltd.), and HAT-CN, HTL-1, TcTa, CzTP, new-DABNA, ETL-1, and ET7 were placed therein. A molybdenum vapor deposition boat and a tungsten vapor deposition boat containing LiF and aluminum were installed.

The following layers were sequentially formed on the ITO film of the transparent support substrate. The vacuum chamber was evacuated to 5×10 ⁻⁴ Pa, and HAT-CN was first heated and evaporated to a thickness of 5 nm to form a hole injection layer. Next, HTL-1 is heated and vapor-deposited to a thickness of 90 nm to form a hole-transport layer 1, and TcTa is heated and vapor-deposited to a thickness of 10 nm to form a hole-transport layer 2. formed. Next, CzTP and new-DABNA were heated at the same time and evaporated to a thickness of 20 nm to form a light-emitting layer. The deposition rate was adjusted so that the weight ratio of CzTP to new-DABNA was approximately 99:1. Next, ETL-1 is heated and evaporated to a thickness of 20 nm to form an electron transport layer 1, and ET7 is heated and evaporated to a thickness of 10 nm to form an electron transport layer 2. bottom. The deposition rate of each layer was 0.01-1 nm/sec. After that, LiF is heated and vapor-deposited at a deposition rate of 0.01 to 0.1 nm/sec so that the film thickness becomes 1 nm, and then aluminum is heated and vapor-deposited so that the film thickness becomes 100 nm to form a cathode. Then, an organic EL device was obtained. At this time, the deposition rate of aluminum was adjusted to 1 to 10 nm/sec.

<Examples 1-1 to 1-3, Examples 2-1 to 2-3, Examples 3-1 to 3-3, Comparative Examples 1-2 to 1-5 and Comparative Example 2-1 to Comparative Example 2-3>
Each device was produced by changing the host or electron transport layer 1 of Comparative Example 1-1 to each material shown in Table 1.

The chemical structures of the compounds used in Examples and Comparative Examples are shown below.

<Evaluation of organic EL element>
A DC voltage was applied to the prepared organic EL element with the ITO electrode as the anode and the aluminum electrode as the cathode, and the external quantum efficiency (EQE) at a luminance of 1000 cd/m ² and LT50 (current density at the initial luminance of 1000 cd/m ² The time to reach 500 cd/m ² in continuous driving) was measured.

The method for measuring the external quantum efficiency is as follows. Using a voltage/current generator R6144 manufactured by Advantest, the device was caused to emit light by applying a voltage. Using a spectral radiance meter SR-3AR manufactured by TOPCON, the spectral radiance in the visible light region was measured from the direction perpendicular to the light emitting surface. Assuming that the light-emitting surface is a perfect diffusion surface, the number of photons at each wavelength is obtained by dividing the measured spectral radiance of each wavelength component by the wavelength energy and multiplying by π. Then, the number of photons in the entire observed wavelength region was integrated to obtain the total number of photons emitted from the device. The external quantum efficiency is obtained by dividing the total number of photons emitted from the device by the number of carriers injected into the device, with the value obtained by dividing the applied current value by the elementary charge as the number of carriers injected into the device.
Table 2 shows the evaluation results.

From Table 2, examples using the triazine compound represented by formula (1) include a compound (CzTP) that does not have both Y ¹ and Y ² of formula (1), a compound that does not have heteroarylene as X ( BTB), or a compound (CPCBPTz) that does not have either Y ¹ or Y ² , high efficiency and long life are obtained. In addition, examples using analogous compounds having a structure in which two heteroaryls are bonded to triazinyl, but the heteroaryls are not groups having N as the bonding position (Comparative Examples 1-4, 1-5, and 1-5) Compared to Example 2-2 and Comparative Example 2-3), the examples using the triazine compound represented by formula (1) (Examples 1-1 to 3 and Examples 2-1 to 2-3) showed high Efficiency and long life were obtained.

Examples 3-1 to 3-3 using the triazine compound represented by Formula (1) as the host material (electron-transporting host material: host 2) in the light-emitting layer and the material of the electron-transporting layer are other examples. higher efficiency and longer life than

REFERENCE SIGNS LIST 100 organic electroluminescent element 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 (13)

a compound represented by formula (1);

In formula (1),
X is substituted or unsubstituted heteroarylene;
Y ¹ is a group represented by formula (1-a),
Y ² is a group represented by formula (1-b),

A ¹ and A ² are each independently substituted or unsubstituted aryl or substituted or unsubstituted heteroaryl;
A ³ and A ⁴ are each independently substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted diarylamino, substituted or unsubstituted diheteroarylamino, or substituted or unsubstituted arylheteroarylamino,
at least one of A ¹ and A ² or A ³ and A ⁴ is a group having N as a bonding position;
Z ¹ , Z ² and Z ³ are each independently CH or N, but at least one of Z ¹ , Z ² and Z ³ is N;
* indicates the binding position,
At least one hydrogen in the compound represented by formula (1) may be replaced with cyano, halogen, or deuterium. Each group having N as the bonding position is independently substituted or unsubstituted N-carbazolyl, substituted or unsubstituted N-azacarbazolyl, substituted or unsubstituted N-benzimidazolyl, substituted or unsubstituted N-imidazoimidazolyl , substituted or unsubstituted N-indoloindolyl, substituted or unsubstituted N-indolocarbazolyl, substituted or unsubstituted N-benzofurocarbazolyl, substituted or unsubstituted N-benzothienocarbazolyl , or substituted or unsubstituted N-indenocarbazolyl. 3. The compound according to claim 1 or 2, wherein both A ¹ and A ² are groups with N as the bonding position. Heteroarylene in X optionally removed two hydrogens bonded to ring atoms of carbazole, azacarbazole, benzimidazole, imidazoimidazole, indoloindole, indolocarbazole, benzofurocarbazole, benzothienocarbazole or indenocarbazole A compound according to any one of claims 1 to 3, which is a divalent group. A compound according to any one of claims 1 to 4, wherein Z ¹ , Z ² and Z ³ are all N. 6. The method according to any one of claims 1 to 5, wherein both A ¹ and A ² are unsubstituted N-carbazolyl, and both A ³ and A ⁴ are unsubstituted N-carbazolyl or unsubstituted phenyl. Compound as described. The compound according to claim 1, represented by any one of the formulas below.

An organic device material containing the compound according to any one of claims 1 to 7. An organic compound having a pair of electrodes consisting of an anode and a cathode, and an organic layer disposed between the pair of electrodes, wherein the organic layer contains the compound according to any one of claims 1 to 7 electroluminescence device. 10. The organic electroluminescent device according to claim 9, wherein said organic layer is a light-emitting layer. 11. The organic electroluminescent device according to claim 10, wherein said light-emitting layer contains said compound as a host material and further contains a dopant material. 10. The organic electroluminescent device according to claim 9, wherein said organic layer is an electron transport layer. A display device or lighting device comprising the organic electroluminescence device according to any one of claims 9 to 12.

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