JP7620282B2 - Polycyclic aromatic compounds - Google Patents

Description

The present invention relates to polycyclic aromatic compounds and their multimers (hereinafter collectively referred to as "polycyclic aromatic compounds"), and to electron transport materials, electron injection materials, organic electroluminescent devices, organic field effect transistors, organic thin-film solar cells, and display devices and lighting devices that use the same. Note that in this specification, "organic electroluminescent devices" may be referred to as "organic EL devices" or simply "devices."

Display devices using electroluminescent light-emitting elements have been extensively studied because they can be made thin and energy-efficient. Furthermore, organic electroluminescent elements made from organic materials have been actively studied because they can be easily made large and lightweight. In particular, there has been active research into the development of organic materials that have the luminescence properties of blue, one of the three primary colors of light, and organic materials that have the ability to transport charges such as holes and electrons (potential to become semiconductors or superconductors), regardless of whether they are polymeric or low molecular weight compounds.

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

As materials for the light-emitting layer, for example, benzofluorene-based compounds have been developed (WO 2004/061047). As hole transport materials, for example, triphenylamine-based compounds have been developed (JP 2001-172232 A). As electron transport materials, for example, anthracene-based compounds have been developed (JP 2005-170911 A).

In recent years, a material that improves triphenylamine derivatives has also been reported as a material for use in organic electroluminescence devices and organic thin-film solar cells (WO 2012/118164). This material is characterized by its improved planarity, which is achieved by linking the aromatic rings that make up the triphenylamine, based on N,N'-diphenyl-N,N'-bis(3-methylphenyl)-1,1'-biphenyl-4,4'-diamine (TPD), which has already been put to practical use. This document evaluates the charge transport properties of, for example, NO-linked compounds (compound 1 on page 63), but does not describe the manufacturing method for materials other than NO-linked compounds. Furthermore, since the electronic state of the entire compound differs depending on the linked element, the properties obtained from materials other than NO-linked compounds are not yet known. There are other examples of such compounds (WO 2011/107186). For example, compounds with a conjugated structure that has a large triplet exciton energy (T1) can emit phosphorescence with a shorter wavelength, making them useful as materials for blue light-emitting layers. Additionally, compounds with new conjugated structures with large T1 are also required as electron transport materials and hole transport materials that sandwich the light-emitting layer.

International Publication No. 2004/061047 JP 2001-172232 A JP 2005-170911 A International Publication No. 2012/118164 International Publication No. 2011/107186 International Publication No. 2015/102118

As mentioned above, various materials have been developed for use in organic EL elements, but in order to increase the options for materials for organic EL elements, there is a need to develop materials made of compounds that are different from conventional ones. In particular, the organic EL characteristics obtained from materials other than the NO-linked compounds reported in Patent Documents 1 to 4, and the methods for producing them, are not yet known.

In addition, Patent Document 6 reports a polycyclic aromatic compound containing boron and an organic EL device using the compound, but there is a demand for electron transport materials that can improve the luminous efficiency and device life to further improve device characteristics.

As a result of intensive research to solve the above problems, the present inventors have found that an excellent organic EL element can be obtained by, for example, constructing an organic EL element by disposing, between a pair of electrodes, an electron transport layer containing a polycyclic aromatic compound into which a nitrogen-containing group having a specific structure has been introduced, and have thus completed the present invention. That is, the present invention provides the following polycyclic aromatic compound.

In this specification, the chemical structure or the substituent may be expressed by the number of carbon atoms, but in the case where a chemical structure is substituted with a substituent or a substituent is further substituted with a substituent, the number of carbon atoms means the number of carbon atoms in each of the chemical structure and the substituent, and does not mean the total number of carbon atoms in the chemical structure and the substituent, or the total number of carbon atoms in the substituent and the substituent. For example, "substituent B of carbon number Y substituted with substituent A of carbon number X" means that "substituent B of carbon number Y" is substituted with "substituent A of carbon number X", and the carbon number Y is not the total number of carbon atoms in the substituents A and B. Also, for example, "substituent B of carbon number Y substituted with substituent A" means that "substituent B of carbon number Y" is substituted with "substituent A (with no carbon number limit)", and the carbon number Y is not the total number of carbon atoms in the substituents A and B.

上記式（１）中、Ａ環、Ｂ環およびＣ環は、それぞれ独立して、アリール環またはヘテロアリール環であり、これらの環における少なくとも１つの水素は置換されていてもよく、また、Ｂ環とＣ環とは－Ｏ－で連結されていてもよく、
上記一般式（ＢｉＮ）中、Ｄ環は少なくとも１つのＮを含むヘテロアリール環であり、Ｅ環は少なくとも１つのＮを含む芳香族環または非芳香族環であり、Ｄ環とＥ環との間に芳香族または非芳香族の縮合環が形成されていてもよく、また、これらの環における少なくとも１つの水素は置換されていてもよく、
Ａ環、Ｂ環およびＣ環における少なくとも１つの水素が、連結基を介して、上記式（ＢｉＮ）で表される基で置換されており、＊は結合位置を示し、
式（１）で表される化合物または構造における、Ａ環、Ｂ環、Ｃ環、アリールおよびヘテロアリールの少なくとも１つは、少なくとも１つのシクロアルカンで縮合されていてもよく、当該シクロアルカンにおける少なくとも１つの水素は置換されていてもよく、当該シクロアルカンにおける少なくとも１つの－ＣＨ_２－は－Ｏ－で置換されていてもよく、そして、
前記化合物またはその多量体における少なくとも１つの水素は、シアノ、ハロゲンまたは重水素で置換されていてもよい。 Item 1.
A polycyclic aromatic compound represented by the following general formula (1), or a multimer of a polycyclic aromatic compound having a plurality of structures represented by the following general formula (1).

In the above formula (1), ring A, ring B and ring C are each independently an aryl ring or a heteroaryl ring, at least one hydrogen atom in these rings may be substituted, and ring B and ring C may be linked via -O-;
In the above general formula (BiN), ring D is a heteroaryl ring containing at least one N, ring E is an aromatic ring or a non-aromatic ring containing at least one N, an aromatic or non-aromatic fused ring may be formed between ring D and ring E, and at least one hydrogen in these rings may be substituted;
at least one hydrogen atom in ring A, ring B and ring C is substituted with a group represented by the above formula (BiN) via a linking group, * indicates a bonding position,
In the compound or structure represented by formula (1), at least one of ring A, ring B, ring C, aryl and heteroaryl may be fused with at least one cycloalkane, at least one hydrogen in the cycloalkane may be substituted, and at least one -CH ₂ - in the cycloalkane may be substituted with -O-, and
At least one hydrogen in the compound or a multimer thereof may be substituted with cyano, halogen or deuterium.

Item 2.
at least one hydrogen atom in ring A, ring B, ring C, ring D, ring E and the fused ring may be substituted by a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted diarylamino, a substituted or unsubstituted diheteroarylamino, a substituted or unsubstituted arylheteroarylamino, a substituted or unsubstituted diarylboryl (two aryls may be bonded via a single bond or a linking group), a substituted or unsubstituted alkyl, a substituted or unsubstituted cycloalkyl, a substituted or unsubstituted alkoxy, a substituted or unsubstituted aryloxy, or a substituted silyl;
Ring A, ring B and ring C each have a 5-membered or 6-membered ring that shares a bond with the central fused two-ring structure of formula (1) composed of a central element "B (boron)" and two elements "O (oxygen)";
the linking group is a single bond, an arylene, a heteroarylene, an alkylene, an alkenylene, an alkynylene, -O-, -S-, >N-R, or a combination thereof, in which R of >N-R is an aryl, a heteroaryl, an alkyl, or a cycloalkyl, and at least one hydrogen in the linking group may be substituted with an aryl, a heteroaryl, an alkyl, or a cycloalkyl;
In the compound or structure represented by formula (1), at least one of ring A, ring B, ring C, aryl and heteroaryl may be fused with at least one cycloalkane, at least one hydrogen in the cycloalkane may be substituted, and at least one -CH ₂ - in the cycloalkane may be substituted with -O-, and
In the case of a polymer, it is a dimer or trimer having two or three structures represented by formula (1).
Item 2. The polycyclic aromatic compound or a multimer thereof according to Item 1.

上記式（２）中、
ａ環、ｂ環、およびｃ環における、任意の「－Ｃ（－Ｒ）＝」（ここでＲは式（２）中のＲ^１～Ｒ^１１である）は「－Ｎ＝」に置き換わっていてもよく、任意の「－Ｃ（－Ｒ）＝Ｃ（－Ｒ）－」（ここでＲは式（２）中のＲ^１～Ｒ^１１である）は、「－Ｎ（－Ｒ）－」、「－Ｏ－」、または「－Ｓ－」に置き換わっていてもよく、前記「－Ｎ（－Ｒ）－」のＲは、アリール、アルキルまたはシクロアルキルであり、
Ｒ^１～Ｒ^１１は、それぞれ独立して、水素、アリール、ヘテロアリール、ジアリールアミノ、ジヘテロアリールアミノ、アリールヘテロアリールアミノ、ジアリールボリル（２つのアリールは単結合または連結基を介して結合していてもよい）、アルキル、シクロアルキル、アルコキシ、アリールオキシ、トリアリールシリル、トリアルキルシリル、トリシクロアルキルシリル、ジアルキルシクロアルキルシリルまたはアルキルジシクロアルキルシリルであり、これらにおける少なくとも１つの水素は、アリール、ヘテロアリール、アルキルまたはシクロアルキルで置換されていてもよく、
Ｒ^１～Ｒ^１１のうちの隣接する基同士が結合してａ環、ｂ環またはｃ環と共にアリール環またはヘテロアリール環を形成していてもよく、形成された環における少なくとも１つの水素は、アリール、ヘテロアリール、ジアリールアミノ、ジヘテロアリールアミノ、アリールヘテロアリールアミノ、ジアリールボリル（２つのアリールは単結合または連結基を介して結合していてもよい）、アルキル、シクロアルキル、アルコキシ、アリールオキシ、トリアリールシリル、トリアルキルシリル、トリシクロアルキルシリル、ジアルキルシクロアルキルシリルまたはアルキルジシクロアルキルシリルで置換されていてもよく、これらにおける少なくとも１つの水素は、アリール、ヘテロアリール、アルキルまたはシクロアルキルで置換されていてもよく、
Ｒ^７およびＲ^８は結合して－Ｏ－となっていてもよく、
項１中の式（ＢｉＮ）中、
Ｄ環は少なくとも１つのＮを含む炭素数２～３０のヘテロアリール環であり、Ｅ環は少なくとも１つのＮを含む炭素数２～３０の芳香族環または炭素数２～３０の非芳香族環であり、Ｄ環とＥ環との間に芳香族または非芳香族の炭素数２～１５の縮合環が形成されていてもよく、
Ｄ環、Ｅ環および前記縮合環における少なくとも１つの水素は、アリール、ヘテロアリール、ジアリールアミノ、ジヘテロアリールアミノ、アリールヘテロアリールアミノ、ジアリールボリル（２つのアリールは単結合または連結基を介して結合していてもよい）、アルキル、シクロアルキル、アルコキシ、アリールオキシ、トリアリールシリル、トリアルキルシリル、トリシクロアルキルシリル、ジアルキルシクロアルキルシリルまたはアルキルジシクロアルキルシリルで置換されていてもよく、これらにおける少なくとも１つの水素は、アリール、ヘテロアリール、アルキルまたはシクロアルキルで置換されていてもよく、
前記Ｒ^１～Ｒ^１１の少なくとも１つが連結基を介した項１中の式（ＢｉＮ）で表される基であるか、または、前記形成されたアリール環もしくはヘテロアリール環における少なくとも１つの水素が連結基を介して式（ＢｉＮ）で表される基で置換されており、＊は結合位置を示し、
前記連結基は、単結合、炭素数６～３０のアリーレン、炭素数２～３０のヘテロアリーレン、炭素数１～２４のアルキレン、炭素数１～２４のアルケニレン、炭素数１～２４のアルキニレン、－Ｏ－、－Ｓ－、＞Ｎ－Ｒまたはこれらの組み合わせであり、前記＞Ｎ－ＲのＲは、炭素数６～１６のアリール、炭素数２～２０のヘテロアリール、炭素数１～１２のアルキルまたは炭素数３～１６のシクロアルキルであり、連結基における少なくとも１つの水素は、炭素数６～１６のアリール、炭素数２～２０のヘテロアリール、炭素数１～１２のアルキルまたは炭素数３～１６のシクロアルキルで置換されていてもよく、
前記化合物またはその多量体における少なくとも１つの水素は、シアノ、ハロゲンまたは重水素で置換されていてもよく、
式（２）で表される化合物または構造における、前記ａ環、前記ｂ環、前記ｃ環、前記形成された環、アリールおよびヘテロアリールの少なくとも１つは、炭素数３～２４の、少なくとも１つのシクロアルカンで縮合されていてもよく、当該シクロアルカンにおける少なくとも１つの水素は、炭素数６～３０のアリール、炭素数２～３０のヘテロアリール、炭素数１～２４のアルキルまたは炭素数３～２４のシクロアルキルで置換されていてもよく、当該シクロアルカンにおける少なくとも１つの－ＣＨ_２－は－Ｏ－で置換されていてもよく、そして、
多量体の場合には、式（２）で表される構造を２個または３個有する２量体または３量体である。 Item 3.
Item 2. The polycyclic aromatic compound or a multimer thereof according to item 1, which is represented by the following general formula (2):

In the above formula (2),
In the ring a, the ring b, and the ring c, any "-C(-R)=" (wherein R is R ¹ to R ¹¹ in formula (2)) may be replaced with "-N=", any "-C(-R)=C(-R)-" (wherein R is R ¹ to R ¹¹ in formula (2)) may be replaced with "-N(-R)-", "-O-", or "-S-", and R in the "-N(-R)-" is aryl, alkyl, or cycloalkyl,
R ¹ to R ¹¹ are each independently hydrogen, aryl, heteroaryl, diarylamino, diheteroarylamino, arylheteroarylamino, diarylboryl (two aryls may be bonded via a single bond or a linking group), alkyl, cycloalkyl, alkoxy, aryloxy, triarylsilyl, trialkylsilyl, tricycloalkylsilyl, dialkylcycloalkylsilyl, or alkyldicycloalkylsilyl, in which at least one hydrogen may be substituted with an aryl, heteroaryl, alkyl, or cycloalkyl;
adjacent groups among R ¹ to R ¹¹ may be bonded to each other to form an aryl ring or a heteroaryl ring together with the ring a, the ring b or the ring c, and at least one hydrogen atom in the formed ring may be substituted with an aryl, a heteroaryl, a diarylamino, a diheteroarylamino, an arylheteroarylamino, a diarylboryl (two aryls may be bonded via a single bond or a linking group), an alkyl, a cycloalkyl, an alkoxy, an aryloxy, a triarylsilyl, a trialkylsilyl, a tricycloalkylsilyl, a dialkylcycloalkylsilyl or an alkyldicycloalkylsilyl, and at least one hydrogen atom in these rings may be substituted with an aryl, a heteroaryl, an alkyl or a cycloalkyl;
R ⁷ and R ⁸ may be bonded to form --O--;
In the formula (BiN) in Item 1,
ring D is a heteroaryl ring containing at least one N and having 2 to 30 carbon atoms; ring E is an aromatic ring containing at least one N and having 2 to 30 carbon atoms or a non-aromatic ring containing 2 to 30 carbon atoms, and an aromatic or non-aromatic fused ring having 2 to 15 carbon atoms may be formed between ring D and ring E;
at least one hydrogen atom in the D ring, the E ring and the fused ring may be substituted with an aryl, a heteroaryl, a diarylamino, a diheteroarylamino, an arylheteroarylamino, a diarylboryl (two aryls may be bonded via a single bond or a linking group), an alkyl, a cycloalkyl, an alkoxy, an aryloxy, a triarylsilyl, a trialkylsilyl, a tricycloalkylsilyl, a dialkylcycloalkylsilyl or an alkyldicycloalkylsilyl, and at least one hydrogen atom in these may be substituted with an aryl, a heteroaryl, an alkyl or a cycloalkyl;
At least one of R ¹ to R ¹¹ is a group represented by formula (BiN) in item 1 via a linking group, or at least one hydrogen atom in the formed aryl ring or heteroaryl ring is substituted with a group represented by formula (BiN) via a linking group, * indicates a bonding position,
the linking group is a single bond, an arylene having 6 to 30 carbon atoms, a heteroarylene having 2 to 30 carbon atoms, an alkylene having 1 to 24 carbon atoms, an alkenylene having 1 to 24 carbon atoms, an alkynylene having 1 to 24 carbon atoms, -O-, -S-, >N-R, or a combination thereof, in which R of >N-R is an aryl having 6 to 16 carbon atoms, a heteroaryl having 2 to 20 carbon atoms, an alkyl having 1 to 12 carbon atoms, or a cycloalkyl having 3 to 16 carbon atoms, and at least one hydrogen atom in the linking group may be substituted with an aryl having 6 to 16 carbon atoms, a heteroaryl having 2 to 20 carbon atoms, an alkyl having 1 to 12 carbon atoms, or a cycloalkyl having 3 to 16 carbon atoms;
At least one hydrogen atom in the compound or a multimer thereof may be replaced with a cyano, a halogen, or a deuterium atom;
In the compound or structure represented by formula (2), at least one of the ring a, the ring b, the ring c, the formed ring, the aryl and the heteroaryl may be condensed with at least one cycloalkane having 3 to 24 carbon atoms, at least one hydrogen in the cycloalkane may be substituted with an aryl having 6 to 30 carbon atoms, a heteroaryl having 2 to 30 carbon atoms, an alkyl having 1 to 24 carbon atoms or a cycloalkyl having 3 to 24 carbon atoms, at least one -CH ₂ - in the cycloalkane may be substituted with -O-, and
In the case of a polymer, it is a dimer or trimer having two or three structures represented by formula (2).

Item 4.
In the above formula (2),
In the ring a, the ring b, and the ring c, any "-C(-R)=" (wherein R is R ¹ to R ¹¹ in formula (2)) may be replaced with "-N=", any "-C(-R)=C(-R)-" (wherein R is R ¹ to R ¹¹ in formula (2)) may be replaced with "-N(-R)-", "-O-", or "-S-", and R in the "-N(-R)-" is an aryl having 6 to 10 carbon atoms, an alkyl having 1 to 5 carbon atoms, or a cycloalkyl having 5 to 10 carbon atoms,
R ¹ to R ¹¹ are each independently hydrogen, an aryl having 6 to 30 carbon atoms, a heteroaryl having 2 to 30 carbon atoms, diarylamino (wherein aryl is an aryl having 6 to 12 carbon atoms), diarylboryl (wherein aryl is an aryl having 6 to 12 carbon atoms, and two aryls may be bonded via a single bond or a linking group), an alkyl having 1 to 24 carbon atoms, a cycloalkyl having 3 to 24 carbon atoms, an alkoxy having 1 to 24 carbon atoms, an aryloxy having 6 to 30 carbon atoms, triarylsilyl (wherein aryl is an aryl having 6 to 12 carbon atoms), or trialkylsilyl (wherein alkyl is an alkyl having 1 to 6 carbon atoms), in which at least one hydrogen may be substituted by an alkyl having 1 to 12 carbon atoms or a cycloalkyl having 3 to 16 carbon atoms;
Adjacent groups among R ¹ to R ¹¹ may be bonded to each other to form an aryl ring having 9 to 16 carbon atoms or a heteroaryl ring having 6 to 15 carbon atoms together with ring a, ring b or ring c, and at least one hydrogen atom in the formed ring may be substituted with an aryl having 6 to 30 carbon atoms, a heteroaryl having 2 to 30 carbon atoms, diarylamino (wherein the aryl is an aryl having 6 to 12 carbon atoms), diarylboryl (wherein the aryl is an aryl having 6 to 12 carbon atoms, and the two aryls may be bonded via a single bond or a linking group), an alkyl having 1 to 24 carbon atoms, a cycloalkyl having 3 to 24 carbon atoms, an alkoxy having 1 to 24 carbon atoms, an aryloxy having 6 to 30 carbon atoms, triarylsilyl (wherein the aryl is an aryl having 6 to 12 carbon atoms), or ^{trialkylsilyl} (wherein the alkyl is an alkyl having 1 to 6 carbon atoms), and at least one hydrogen atom in these rings may be substituted with an alkyl having 1 to 12 carbon atoms or a cycloalkyl having 3 to 16 carbon atoms; ⁸ may be bonded to form --O--;
In the above formula (BiN),
ring D is a heteroaryl ring containing at least one N and having 2 to 20 carbon atoms; ring E is an aromatic ring containing at least one N and having 2 to 20 carbon atoms or a non-aromatic ring containing 2 to 20 carbon atoms, and an aromatic or non-aromatic fused ring having 2 to 10 carbon atoms may be formed between ring D and ring E;
at least one hydrogen atom in ring D, ring E and the fused ring may be substituted with an aryl having 6 to 30 carbon atoms, a heteroaryl having 2 to 30 carbon atoms, diarylamino (wherein aryl is an aryl having 6 to 12 carbon atoms), diarylboryl (wherein aryl is an aryl having 6 to 12 carbon atoms, and two aryls may be bonded via a single bond or a linking group), an alkyl having 1 to 24 carbon atoms, a cycloalkyl having 3 to 24 carbon atoms, an alkoxy having 1 to 24 carbon atoms, an aryloxy having 6 to 30 carbon atoms, triarylsilyl (wherein aryl is an aryl having 6 to 12 carbon atoms), or trialkylsilyl (wherein alkyl is an alkyl having 1 to 6 carbon atoms), and at least one hydrogen atom in these may be substituted with an alkyl having 1 to 12 carbon atoms or a cycloalkyl having 3 to 16 carbon atoms;
at least one of R ¹ to R ¹¹ is a group represented by the above formula (BiN) via a linking group, or at least one hydrogen atom in the formed aryl ring or heteroaryl ring is substituted with a group represented by the formula (BiN) via a linking group, * indicates a bonding position,
the linking group is a single bond, an arylene having 6 to 12 carbon atoms, a heteroarylene having 2 to 15 carbon atoms, an alkylene having 1 to 12 carbon atoms, an alkenylene having 1 to 12 carbon atoms, an alkynylene having 1 to 12 carbon atoms, -O-, -S-, >N-R, or a combination thereof, in which R of >N-R is an aryl having 6 to 10 carbon atoms, a heteroaryl having 2 to 10 carbon atoms, an alkyl having 1 to 4 carbon atoms, or a cycloalkyl having 5 to 10 carbon atoms, and at least one hydrogen atom in the linking group may be substituted with an alkyl having 1 to 4 carbon atoms or a cycloalkyl having 5 to 10 carbon atoms;
At least one hydrogen atom in the compound or a multimer thereof may be replaced with a cyano, a halogen, or a deuterium atom;
In the compound or structure represented by formula (2), at least one of the ring a, the ring b, the ring c, the formed ring, aryl and heteroaryl may be condensed with at least one cycloalkane having 3 to 16 carbon atoms, and at least one hydrogen in the cycloalkane may be substituted with an alkyl having 1 to 6 carbon atoms or a cycloalkyl having 3 to 14 carbon atoms, and
In the case of a polymer, it is a dimer having two structures represented by formula (2).
Item 4. A polycyclic aromatic compound or a multimer thereof according to Item 3.

Item 5.
In the above formula (2),
In the ring a, the ring b, and the ring c, any "-C(-R)=" (wherein R is R ¹ to R ¹¹ in formula (2)) may be replaced with "-N=", any "-C(-R)=C(-R)-" (wherein R is R ¹ to R ¹¹ in formula (2)) may be replaced with "-N(-R)-", "-O-", or "-S-", and R in the "-N(-R)-" is an aryl having 6 to 10 carbon atoms, an alkyl having 1 to 5 carbon atoms, or a cycloalkyl having 5 to 10 carbon atoms,
R ¹ to R ¹¹ are each independently hydrogen, an aryl having 6 to 16 carbon atoms, a heteroaryl having 2 to 20 carbon atoms, diarylamino (wherein aryl is an aryl having 6 to 10 carbon atoms), diarylboryl (wherein aryl is an aryl having 6 to 10 carbon atoms, and two aryls may be bonded via a single bond or a linking group), an alkyl having 1 to 12 carbon atoms, a cycloalkyl having 3 to 16 carbon atoms, an alkoxy having 1 to 6 carbon atoms, an aryloxy having 6 to 16 carbon atoms, triarylsilyl (wherein aryl is an aryl having 6 to 10 carbon atoms), or trialkylsilyl (wherein alkyl is an alkyl having 1 to 4 carbon atoms), in which at least one hydrogen may be substituted by an alkyl having 1 to 4 carbon atoms or a cycloalkyl having 5 to 10 carbon atoms;
adjacent groups among R ¹ to R ¹¹ may be bonded to each other to form an aryl ring having 9 to 16 carbon atoms or a heteroaryl ring having 6 to 15 carbon atoms together with the ring a, ring b or ring c, in which at least one hydrogen atom in the formed ring may be replaced by an aryl having 6 to 16 carbon atoms, a heteroaryl having 2 to 20 carbon atoms, diarylamino (wherein the aryl is an aryl having 6 to 10 carbon atoms), diarylboryl (wherein the aryl is an aryl having 6 to 10 carbon atoms, and the two aryls may be bonded via a single bond or a linking group), an alkyl having 1 to 12 carbon atoms, a cycloalkyl having 3 to 16 carbon atoms, an alkoxy having 1 to 6 carbon atoms, an aryloxy having 6 to 16 carbon atoms, triarylsilyl (wherein the aryl is an aryl having 6 to 10 carbon atoms), or trialkylsilyl (wherein the alkyl is an alkyl having 1 to 4 carbon atoms), in which at least one hydrogen atom may be replaced by an alkyl having 1 to 4 carbon atoms or a cycloalkyl having 5 to 10 carbon atoms; R ⁷ and R ⁸ may be bonded to each other to form -O-;
In the above formula (BiN),
ring D is a heteroaryl ring containing at least one N and having 2 to 10 carbon atoms; ring E is an aromatic ring containing at least one N and having 2 to 10 carbon atoms or a non-aromatic ring containing 2 to 10 carbon atoms, and an aromatic or non-aromatic fused ring having 2 to 10 carbon atoms may be formed between ring D and ring E;
at least one hydrogen atom in ring D, ring E and the fused ring may be substituted with an aryl having 6 to 16 carbon atoms, a heteroaryl having 2 to 20 carbon atoms, diarylamino (wherein aryl is an aryl having 6 to 10 carbon atoms), diarylboryl (wherein aryl is an aryl having 6 to 10 carbon atoms, and two aryls may be bonded via a single bond or a linking group), an alkyl having 1 to 12 carbon atoms, a cycloalkyl having 3 to 16 carbon atoms, an alkoxy having 1 to 6 carbon atoms, an aryloxy having 6 to 16 carbon atoms, triarylsilyl (wherein aryl is an aryl having 6 to 10 carbon atoms), or trialkylsilyl (wherein alkyl is an alkyl having 1 to 4 carbon atoms), and at least one hydrogen atom in these may be substituted with an alkyl having 1 to 4 carbon atoms or a cycloalkyl having 5 to 10 carbon atoms;
at least one of R ¹ to R ¹¹ is a group represented by the above formula (BiN) via a linking group, or at least one hydrogen atom in the formed aryl ring or heteroaryl ring is substituted with a group represented by the formula (BiN) via a linking group, * indicates a bonding position,
the linking group is a single bond, an arylene having 6 to 10 carbon atoms, an alkylene having 1 to 6 carbon atoms, an alkenylene having 1 to 6 carbon atoms, -O-, or a combination thereof, and at least one hydrogen atom in the linking group may be substituted with an alkyl having 1 to 4 carbon atoms;
At least one hydrogen atom in the compound or a multimer thereof may be replaced with a cyano, a halogen, or a deuterium atom;
In the compound or structure represented by formula (2), at least one of the ring a, the ring b, the ring c, the formed ring, aryl and heteroaryl may be condensed with at least one cycloalkane having 3 to 16 carbon atoms, and at least one hydrogen in the cycloalkane may be substituted with an alkyl having 1 to 6 carbon atoms or a cycloalkyl having 3 to 14 carbon atoms, and
In the case of a polymer, it is a dimer having two structures represented by formula (2).
Item 4. A polycyclic aromatic compound or a multimer thereof according to Item 3.

Item 6.
In the above formula (2),
In the ring a, the ring b, and the ring c, any "-C(-R)=" (wherein R is R ¹ to R ¹¹ in formula (2)) may be replaced with "-N=", any "-C(-R)=C(-R)-" (wherein R is R ¹ to R ¹¹ in formula (2)) may be replaced with "-N(-R)-", "-O-", or "-S-", and R in the "-N(-R)-" is an aryl having 6 to 10 carbon atoms, an alkyl having 1 to 5 carbon atoms, or a cycloalkyl having 5 to 10 carbon atoms,
R ¹ to R ¹¹ are each independently hydrogen, aryl having 6 to 12 carbon atoms, heteroaryl having 2 to 15 carbon atoms, diarylamino (wherein aryl is an aryl having 6 to 10 carbon atoms), alkyl having 1 to 6 carbon atoms, cycloalkyl having 3 to 14 carbon atoms, triarylsilyl (wherein aryl is an aryl having 6 to 10 carbon atoms), or trialkylsilyl (wherein alkyl is an alkyl having 1 to 4 carbon atoms), in which at least one hydrogen may be substituted by alkyl having 1 to 4 carbon atoms;
R ⁷ and R ⁸ may be bonded to form --O--;
In the above formula (BiN),
D ring is an oxazole ring, an isoxazole ring, a thiazole ring, an isothiazole ring, an imidazole ring, an oxadiazole ring, a thiadiazole ring, a triazole ring, a tetrazole ring, a pyrazole ring, a pyridine ring, a pyrimidine ring, a pyridazine ring, a pyrazine ring, a triazine ring, a 1H-indazole ring, a benzimidazole ring, a benzoxazole ring, a benzothiazole ring, a quinoline ring, an isoquinoline ring, a quinazoline ring, a quinoxaline ring, a phthalazine ring, a naphthyridine ring, a purine ring, a pteridine ring, or a furazan ring;
Ring E is an oxazole ring, an isoxazole ring, a thiazole ring, an isothiazole ring, an imidazole ring, an oxadiazole ring, a thiadiazole ring, a triazole ring, a tetrazole ring, a pyrazole ring, a pyridine ring, a pyrimidine ring, a pyridazine ring, a pyrazine ring, a triazine ring, a 1H-indazole ring, a benzimidazole ring, a benzoxazole ring, a benzothiazole ring, a quinoline ring, an isoquinoline ring, a quinazoline ring, a quinoxaline ring, a phthalazine ring, a naphthyridine ring, a purine ring, a pteridine ring, or a furazan ring;
the fused ring is a tetrahydrobenzene ring, a dihydrobenzene ring, a cyclopentane ring, or a cyclohexane ring;
at least one hydrogen atom in ring D, ring E and the fused ring may be optionally substituted with an aryl having 6 to 12 carbon atoms, a heteroaryl having 2 to 15 carbon atoms, diarylamino (wherein aryl is an aryl having 6 to 10 carbon atoms), an alkyl having 1 to 6 carbon atoms, a cycloalkyl having 3 to 14 carbon atoms, triarylsilyl (wherein aryl is an aryl having 6 to 10 carbon atoms) or trialkylsilyl (wherein alkyl is an alkyl having 1 to 4 carbon atoms), and at least one hydrogen atom in these may be optionally substituted with an alkyl having 1 to 4 carbon atoms;
at least one of R ¹ to R ¹¹ is a group represented by the above formula (BiN) via a linking group, or at least one hydrogen atom in the formed aryl ring or heteroaryl ring is substituted with a group represented by the formula (BiN) via a linking group, * indicates a bonding position,
the linking group is a single bond, phenylene, naphthylene, an alkylene having 1 to 4 carbon atoms, -O-, or a combination thereof, and at least one hydrogen atom in the linking group may be substituted with an alkyl having 1 to 4 carbon atoms;
At least one hydrogen atom in the compound or a multimer thereof may be replaced with a cyano, a halogen, or a deuterium atom;
In the compound or structure represented by formula (2), at least one of the ring a, the ring b, the ring c, the formed ring, aryl and heteroaryl may be condensed with at least one cycloalkane having 3 to 16 carbon atoms, and at least one hydrogen in the cycloalkane may be substituted with an alkyl having 1 to 6 carbon atoms or a cycloalkyl having 3 to 14 carbon atoms, and
In the case of a polymer, it is a dimer having two structures represented by formula (2).
Item 4. A polycyclic aromatic compound or a multimer thereof according to Item 3.

上記構造式中のＭｅはメチル基、＊は結合位置を示す。 Item 7.
Item 6. The polycyclic aromatic compound or a multimer thereof according to any one of Items 1 to 5, wherein the group represented by the formula (BiN) is a group represented by any one of the following formulas:

In the above structural formula, Me represents a methyl group, and * represents a bonding position.

Item 8.
Item ^8. A polycyclic aromatic ^compound or a multimer thereof according to any one of Items 3 to 7 ^, wherein in the formula (2), R ¹ and R ³ , R ⁴ and R ¹¹ , R ⁵ and R ¹⁰ , R ⁶ and R ⁹ , R ² , R ⁴ and R ^{11 , R 2 ,} R 5 and R ¹⁰ , or R 2 , R 6 and R ⁹ are a group represented by the formula (BiN).

Item 9.
Item 2. The polycyclic aromatic compound according to item 1, which is represented by any one of the following structural formulas:

Item 10.
Item 10. A material for an organic device, comprising the polycyclic aromatic compound or a multimer thereof according to any one of items 1 to 9.

Item 11.
Item 11. The material for an organic device according to item 10, which is a material for an organic electroluminescent element, a material for an organic field effect transistor, or a material for an organic thin-film solar cell.

Item 12.
Item 12. The material for an organic device according to item 11, wherein the material for an organic electroluminescent element is a material for an electron transport layer or a material for an electron injection layer.

Item 13.
Item 13. An organic electroluminescence device comprising a pair of electrodes consisting of an anode and a cathode, a light-emitting layer disposed between the pair of electrodes, and at least one of an electron transport layer and an electron injection layer disposed between the cathode and the light-emitting layer, wherein at least one of the electron transport layer and the electron injection layer contains the material for an organic device according to item 12.

Item 14.
Item 14. The organic electroluminescence device according to item 13, wherein at least one of the electron transport layer and the electron injection layer contains at least one selected from the group consisting of borane derivatives, pyridine derivatives, fluoranthene derivatives, BO-based derivatives, anthracene derivatives, benzofluorene derivatives, phosphine oxide derivatives, pyrimidine derivatives, carbazole derivatives, triazine derivatives, benzimidazole derivatives, phenanthroline derivatives, and quinolinol-based metal complexes.

Item 15.
Item 15. The organic electroluminescent device according to item 13 or 14, wherein at least one of the electron transport layer and the electron injection layer contains at least one selected from the group consisting of alkali metals, alkaline earth metals, rare earth metals, oxides of alkali metals, oxides of alkaline earth metals, oxides of rare earth metals, halides of alkali metals, halides of alkaline earth metals, halides of rare earth metals, organic complexes of alkali metals, organic complexes of alkaline earth metals, and organic complexes of rare earth metals.

上記式（６）中、
Ａ環、Ｂ環およびＣ環は、それぞれ独立して、アリール環またはヘテロアリール環であり、これらの環における少なくとも１つの水素は置換されていてもよく、
Ｘ^１およびＸ^２は、それぞれ独立して、＞Ｏ、＞Ｎ－Ｒ、＞Ｃ（－Ｒ）_２、＞Ｓまたは＞Ｓｅであり、前記＞Ｎ－ＲのＲは、置換されていてもよいアリール、置換されていてもよいヘテロアリール、置換されていてもよいアルキルまたは置換されていてもよいシクロアルキルであり、前記＞Ｃ（－Ｒ）_２のＲは、水素、置換されていてもよいアリール、置換されていてもよいアルキルまたは置換されていてもよいシクロアルキルであり、また、前記＞Ｎ－ＲのＲおよび前記＞Ｃ（－Ｒ）_２のＲの少なくとも１つは、連結基により、前記Ａ環、Ｂ環およびＣ環の少なくとも１つの環と結合していてもよく、
式（６）で表される化合物における、Ａ環、Ｂ環、Ｃ環、アリールおよびヘテロアリールの少なくとも１つは、少なくとも１つのシクロアルカンで縮合されていてもよく、当該シクロアルカンにおける少なくとも１つの水素は置換されていてもよく、当該シクロアルカンにおける少なくとも１つの－ＣＨ_２－は－Ｏ－で置換されていてもよく、そして、
式（６）で表される化合物における少なくとも１つの水素は、シアノ、ハロゲンまたは重水素で置換されていてもよい。

上記式（７）中、
Ａ環、Ｂ環およびＣ環は、それぞれ独立して、アリール環またはヘテロアリール環であり、これらの環における少なくとも１つの水素は置換されていてもよく、
Ｘ^１、Ｘ^２およびＸ^３は、それぞれ独立して、＞Ｏ、＞Ｎ－Ｒ、＞Ｃ（－Ｒ）_２、＞Ｓまたは＞Ｓｅであり、前記＞Ｎ－ＲのＲは、置換されていてもよいアリール、置換されていてもよいヘテロアリール、置換されていてもよいアルキルまたは置換されていてもよいシクロアルキルであり、前記＞Ｃ（－Ｒ）_２のＲは、水素、置換されていてもよいアリール、置換されていてもよいアルキルまたは置換されていてもよいシクロアルキルであり、また、前記＞Ｎ－ＲのＲおよび前記＞Ｃ（－Ｒ）_２のＲの少なくとも１つは、連結基により、前記Ａ環、Ｂ環およびＣ環の少なくとも１つの環と結合していてもよく、
式（７）で表される化合物または構造における、Ａ環、Ｂ環、Ｃ環、アリールおよびヘテロアリールの少なくとも１つは、少なくとも１つのシクロアルカンで縮合されていてもよく、当該シクロアルカンにおける少なくとも１つの水素は置換されていてもよく、当該シクロアルカンにおける少なくとも１つの－ＣＨ_２－は－Ｏ－で置換されていてもよく、そして、
式（７）で表される化合物における少なくとも１つの水素は、シアノ、ハロゲンまたは重水素で置換されていてもよい。

上記式（８）中、
Ａ環およびＢ環は、それぞれ独立して、アリール環またはヘテロアリール環であり、これらの環における少なくとも１つの水素は置換されていてもよく、
Ｘ^１およびＸ^２は、それぞれ独立して、＞Ｏ、＞Ｎ－Ｒ、＞Ｃ（－Ｒ）_２、＞Ｓまたは＞Ｓｅであり、前記＞Ｎ－ＲのＲは、置換されていてもよいアリール、置換されていてもよいヘテロアリール、置換されていてもよいアルキルまたは置換されていてもよいシクロアルキルであり、前記＞Ｃ（－Ｒ）_２のＲは、水素、置換されていてもよいアリール、置換されていてもよいアルキルまたは置換されていてもよいシクロアルキルであり、また、前記＞Ｎ－ＲのＲおよび前記＞Ｃ（－Ｒ）_２のＲの少なくとも１つは、連結基により、前記Ａ環およびＢ環の少なくとも１つの環と結合していてもよく、
Ｒ^４およびＲ^７は、それぞれ独立して、水素、炭素数６～１２のアリール、炭素数２～１５のヘテロアリール、ジアリールアミノ（ただしアリールは炭素数６～１２のアリール）、炭素数１～６のアルキルまたは炭素数３～１４のシクロアルキルであり、
式（８）で表される化合物または構造における、Ａ環、Ｂ環、アリールおよびヘテロアリールの少なくとも１つは、少なくとも１つのシクロアルカンで縮合されていてもよく、当該シクロアルカンにおける少なくとも１つの水素は置換されていてもよく、当該シクロアルカンにおける少なくとも１つの－ＣＨ_２－は－Ｏ－で置換されていてもよく、そして、
式（８）で表される化合物における少なくとも１つの水素は、シアノ、ハロゲンまたは重水素で置換されていてもよい。 Item 16.
Item 16. The organic electroluminescent device according to any one of items 13 to 15, wherein the light-emitting layer contains at least one selected from the group consisting of a polycyclic aromatic compound represented by the following general formula (6), a polycyclic aromatic compound represented by the following general formula (7), and a polycyclic aromatic compound represented by the following general formula (8):

In the above formula (6),
ring A, ring B and ring C are each independently an aryl ring or a heteroaryl ring, and at least one hydrogen atom in these rings may be substituted;
^X1 and ^X2 are each independently >O, >N-R, >C(-R) ₂ , >S or >Se, R of the >N-R is an optionally substituted aryl, an optionally substituted heteroaryl, an optionally substituted alkyl or an optionally substituted cycloalkyl, R of the >C(-R) ₂ is a hydrogen, an optionally substituted aryl, an optionally substituted alkyl or an optionally substituted cycloalkyl, and at least one of the R of the >N-R and the R of the >C(-R) ₂ may be bonded to at least one of the rings A, B and C via a linking group;
In the compound represented by formula (6), at least one of ring A, ring B, ring C, aryl, and heteroaryl may be condensed with at least one cycloalkane, at least one hydrogen in the cycloalkane may be substituted, and at least one -CH ₂ - in the cycloalkane may be substituted with -O-, and
At least one hydrogen atom in the compound represented by formula (6) may be substituted with cyano, halogen or deuterium.

In the above formula (7),
ring A, ring B and ring C are each independently an aryl ring or a heteroaryl ring, and at least one hydrogen atom in these rings may be substituted;
X ¹ , X ² and X ³ are each independently >O, >N-R, >C(-R) ₂ , >S or >Se, R of the >N-R is an optionally substituted aryl, an optionally substituted heteroaryl, an optionally substituted alkyl or an optionally substituted cycloalkyl, R of the >C(-R) ₂ is a hydrogen, an optionally substituted aryl, an optionally substituted alkyl or an optionally substituted cycloalkyl, and at least one of the R of the >N-R and the R of the >C(-R) ₂ may be bonded to at least one of the rings A, B and C via a linking group;
In the compound or structure represented by formula (7), at least one of ring A, ring B, ring C, aryl and heteroaryl may be fused with at least one cycloalkane, at least one hydrogen in the cycloalkane may be substituted, and at least one -CH ₂ - in the cycloalkane may be substituted with -O-, and
At least one hydrogen atom in the compound represented by formula (7) may be substituted with cyano, halogen or deuterium.

In the above formula (8),
ring A and ring B are each independently an aryl ring or a heteroaryl ring, and at least one hydrogen atom in these rings may be substituted;
^X1 and ^X2 are each independently >O, >N-R, >C(-R) ₂ , >S or >Se, R of the >N-R is an optionally substituted aryl, an optionally substituted heteroaryl, an optionally substituted alkyl or an optionally substituted cycloalkyl, R of the >C(-R) ₂ is a hydrogen, an optionally substituted aryl, an optionally substituted alkyl or an optionally substituted cycloalkyl, and at least one of the R of the >N-R and the R of the >C(-R) ₂ may be bonded to at least one of the rings A and B via a linking group;
R ⁴ and R ⁷ are each independently hydrogen, an aryl having 6 to 12 carbon atoms, a heteroaryl having 2 to 15 carbon atoms, a diarylamino (wherein the aryl has 6 to 12 carbon atoms), an alkyl having 1 to 6 carbon atoms, or a cycloalkyl having 3 to 14 carbon atoms;
In the compound or structure represented by formula (8), at least one of ring A, ring B, aryl and heteroaryl may be fused with at least one cycloalkane, at least one hydrogen in the cycloalkane may be substituted, and at least one -CH ₂ - in the cycloalkane may be substituted with -O-, and
At least one hydrogen atom in the compound represented by formula (8) may be substituted with cyano, halogen or deuterium.

Item 17.
Item 17. A display device or lighting device comprising the organic electroluminescent device according to any one of Items 13 to 16.

According to a preferred embodiment of the present invention, it is possible to provide a novel polycyclic aromatic compound that can be used as a material for organic devices, such as a material for an organic EL element, and by using this polycyclic aromatic compound, it is possible to provide an excellent organic device, such as an organic EL element.

Specifically, the present inventors have found that polycyclic aromatic compounds (basic skeleton portions) in which aromatic rings are linked by heteroatoms of boron and oxygen have a large HOMO-LUMO gap (band gap Eg in a thin film) and high triplet excitation energy (E _T ). This is believed to be because the six-membered ring containing a heteroatom has low aromaticity, which suppresses the decrease in the HOMO-LUMO gap associated with the expansion of the conjugated system, and because electronic perturbation of the heteroatom results in localization of SOMO1 and SOMO2 in the triplet excited state (T1). In addition, the polycyclic aromatic compound (basic skeleton portion) containing a hetero element according to the present invention has a small exchange interaction between the two orbitals due to the localization of SOMO1 and SOMO2 in the triplet excited state (T1), so that the energy difference between the triplet excited state (T1) and the singlet excited state (S1) is small and the compound exhibits thermally activated delayed fluorescence (TADF), making it useful as a fluorescent material for an organic EL element (including an element using TADF). In addition, a material having a high triplet excitation energy (E _T ) is also useful as an electron transport layer or hole transport layer for a phosphorescent organic EL element or an organic EL element using TADF. Furthermore, these polycyclic aromatic compounds (basic skeleton portion) can arbitrarily move the energy of HOMO and LUMO by introducing a substituent, so that it is possible to optimize the ionization potential and electron affinity according to the surrounding material.

The nitrogen-containing substituent in the present invention has a chelating structure such as bipyridine or 1,10-phenanthroline in the substituent, so that, for example, by chelating with lithium atoms contained in a Li/Al cathode, the electron injection barrier can be reduced. As described above, the BO2-based polycyclic aromatic skeleton, which is the basic skeleton portion, exhibits high electron mobility, so that the nitrogen-containing substituent introduced in the present invention can enhance the electron injection property to make it a more useful material for an electron transport layer or an electron injection layer. In this way, by using a material for an electron transport layer or an electron injection layer having both high electron injection property and high electron mobility, an organic device with a low driving voltage, such as an organic EL element, can be produced. In addition, since the triplet level of the BO2-based polycyclic aromatic skeleton is high due to the multiple resonance effect, the compound of the present invention is also useful as a hole blocking material in a phosphorescent organic EL element or a TADF organic EL element.

1 is a schematic cross-sectional view showing an organic EL element according to an embodiment of the present invention.

1. Polycyclic aromatic compounds and multimers thereof The present invention relates to a polycyclic aromatic compound represented by the following general formula (1), or a multimer of a polycyclic aromatic compound having a plurality of structures represented by the following general formula (1), in which at least one hydrogen atom in the A ring, the B ring, and the C ring is substituted with a group represented by the following general formula (BiN) via a linking group. Also, preferably, the present invention relates to a polycyclic aromatic compound represented by the following general formula (2), or a multimer of a polycyclic aromatic compound having a plurality of structures represented by the following general formula (2), in which at least one of R ¹ to R ¹¹ is a group represented by the following general formula (BiN) via a linking group, or at least one hydrogen atom in the formed aryl ring or heteroaryl ring (a ring, a ring, or a ring c ring formed by bonding adjacent groups among R ¹ to R ¹¹ ) is substituted with a group represented by the formula (BiN) via a linking group. The definitions of the symbols in the following structural formulas are the same as the definitions of the symbols in the general formulas (1), (2), and (BiN), and the same applies hereinafter.

In general formula (1), ring A, ring B, and ring C are each independently an aryl ring or a heteroaryl ring, and at least one hydrogen atom in these rings may be substituted with a substituent. The substituent is preferably a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted diarylamino, a substituted or unsubstituted diheteroarylamino, a substituted or unsubstituted arylheteroarylamino (an amino group having an aryl and a heteroaryl), a substituted or unsubstituted diarylboryl (two aryls may be bonded via a single bond or a linking group), a substituted or unsubstituted alkyl, a substituted or unsubstituted cycloalkyl, a substituted or unsubstituted alkoxy, a substituted or unsubstituted aryloxy, or a substituted silyl. In the case where these groups have a substituent, examples of the substituent include an aryl, a heteroaryl, an alkyl, or a cycloalkyl. In addition, the aryl ring or the heteroaryl ring preferably has a 5-membered or 6-membered ring that shares a bond with the central fused two-ring structure of general formula (1) composed of the central element "B (boron)" and two elements "O (oxygen)".

Here, the term "fused bicyclic structure" refers to a structure in which two saturated hydrocarbon rings containing the central element "B (boron)" and two elements "O (oxygen)" are fused together, as shown in the center of the general formula (1). The term "six-membered ring sharing a bond with the fused bicyclic structure" refers to the a ring (benzene ring (six-membered ring)) fused to the fused bicyclic structure, as shown in the general formula (2) above. The term "aryl ring or heteroaryl ring (A ring) has this six-membered ring" means that the A ring is formed by this six-membered ring alone, or that the A ring is formed by further condensing other rings to this six-membered ring so as to include this six-membered ring. In other words, the term "aryl ring or heteroaryl ring (A ring) having a six-membered ring" refers to the six-membered ring constituting all or part of the A ring being fused to the fused bicyclic structure. The same explanation applies to "B ring (b ring)", "C ring (c ring)", and "five-membered ring".

Ring A (or ring B, ring C) in general formula (1) corresponds to ring a and its substituents R ¹ to R ³ (or ring b and its substituents R ⁸ to R ¹¹ , ring c and its substituents R ⁴ to R ⁷ ) in general formula (2). That is, general formula (2) corresponds to a structure in which "rings A to C having 6-membered rings" are selected as rings A to C in general formula (1). In that sense, each ring in general formula (2) is represented by lowercase letters a to c.

In the general formula (2), adjacent groups among the substituents R ¹ to R ¹¹ of the ring a, ring b, and ring c may be bonded together to form an aryl ring or a heteroaryl ring together with the ring a, ring b, or ring c, and at least one hydrogen atom in the formed ring may be substituted with an aryl, heteroaryl, diarylamino, diheteroarylamino, arylheteroarylamino, diarylboryl (two aryls may be bonded via a single bond or a linking group), alkyl, cycloalkyl, alkoxy, aryloxy, triarylsilyl, trialkylsilyl, tricycloalkylsilyl, dialkylcycloalkylsilyl, or alkyldicycloalkylsilyl, and at least one hydrogen atom in these may be substituted with an aryl, heteroaryl, alkyl, or cycloalkyl. Thus, the ring structure constituting the polycyclic aromatic compound represented by the general formula (2) changes depending on the mutual bonding form of the substituents in the ring a, ring b, and ring c, as shown in the following formulas (2-1) and (2-2). The rings A', B' and C' in each formula correspond to the rings A, B and C in general formula (1), respectively.

In the above formula (2-1) and formula (2-2), the A' ring, B' ring, and C' ring are aryl or heteroaryl rings formed with the a ring, b ring, and c ring by bonding adjacent groups among the substituents R ¹ to R ^11, respectively (they may also be considered as condensed rings formed by condensing other ring structures to the a ring, b ring, or c ring). Although not shown in the formula, there are also compounds in which the a ring, b ring, and c ring are all changed to the A' ring, B' ring, and C' ring. In addition, as can be seen from the above formula (2-1) and formula (2-2), for example, R ⁸ of the b ring and R ⁷ of the c ring, R ¹¹ of the b ring and R ¹ of the a ring, R ⁴ of the c ring and R ³ of the a ring, etc. are not "adjacent groups", and unless otherwise specified, they are not bonded to each other. In other words, "adjacent groups" means adjacent groups on the same ring.

The compounds represented by the above formula (2-1) or formula (2-2) are compounds having ring A' (or ring B' or ring C') formed by condensing a benzene ring, which is ring a (or ring b or ring c), with a benzene ring, an indole ring, a pyrrole ring, a benzofuran ring or a benzothiophene ring, and the condensed ring A' (or condensed ring B' or condensed ring C') formed is a naphthalene ring, a carbazole ring, an indole ring, a dibenzofuran ring or a dibenzothiophene ring, respectively.

In addition, the ring B and the ring C in the general formula (1) may be linked by --O--, and in the general formula (2), for example, R ⁷ and R ⁸ may be linked to form --O--.

以上に示すように、例えばｃ環における「－Ｃ（－Ｒ^５）＝」の箇所が「－Ｎ＝」に置き換わってもよく、このようにして、式（２）でベンゼン環として表示されるｃ環は、ピリジン環、ピリミジン環、ピリダジン環、ピラジン環、その他の含窒素ヘテロアリール環に変化してもよい。また、ｃ環上に隣接する基が存在する場合（上記式中ではＲ^６およびＲ^７）には、これらが結合してｃ環と共にヘテロアリール環（上記式中ではキノリン環）を形成し、形成された環がさらに置換されていてもよい（ｎ個のＲで示す）ことは、上述したとおりである。
その他、以下のような変形例もある。

その他の箇所が「－Ｎ＝」に置き換わった場合や、ａ環またはｂ環が変化した場合についても同じである。 In formula (2), any "-C(-R)=" (wherein R is R ¹ to R ¹¹ in formula (2)) in ring a, ring b, and ring c may be replaced with "-N=".

As shown above, for example, "-C(-R ⁵ )=" in ring c may be replaced with "-N=", and thus ring c shown as a benzene ring in formula (2) may be changed to a pyridine ring, pyrimidine ring, pyridazine ring, pyrazine ring, or other nitrogen-containing heteroaryl ring. In addition, when adjacent groups are present on ring c (R ⁶ and R ⁷ in the above formula), they are bonded to form a heteroaryl ring (a quinoline ring in the above formula) together with ring c, and the ring formed may be further substituted (represented by n Rs), as described above.
In addition, there are the following variations:

The same applies when other positions are replaced with "-N=" or when the a ring or b ring is changed.

以上に示すように、例えばｃ環における「－Ｃ（－Ｒ^７）＝Ｃ（－Ｒ^６）－」の箇所が「－Ｎ（－Ｒ）－」、「－Ｏ－」、または「－Ｓ－」に置き換わってもよく、このようにして、式（２）でベンゼン環として表示されるｃ環は、Ｒ置換のピロール環、フラン環、チオフェン環、その他の含窒素・酸素・硫黄ヘテロアリール環に変化してもよい。また、ｃ環上に隣接する基が存在する場合（上記式中ではＲ^４およびＲ^５）には、これらが結合してｃ環と共にヘテロアリール環（上記式中ではＲ置換のインドール環、ベンゾフラン環、またはベンゾチオフェン環）を形成し、形成された環がさらに置換されていてもよい（ｎ個のＲで示す）ことは、上述したとおりである。
その他、以下のような変形例もある。

その他の箇所が「－Ｎ（－Ｒ）－」、「－Ｏ－」、または「－Ｓ－」に置き換わった場合や、ａ環またはｂ環が変化した場合についても同じである。 In formula (2), any "-C(-R)=C(-R)-" (wherein R is R ¹ to R ¹¹ in formula (2)) in ring a, ring b, and ring c may be replaced with "-N(-R)-", "-O-", or "-S-", and R in the "-N(-R)-" is aryl, alkyl, or cycloalkyl. Details of the substituents listed here will be described below.

As shown above, for example, "-C(-R ⁷ )=C(-R ⁶ )-" in ring c may be replaced with "-N(-R)-", "-O-" or "-S-", and thus ring c shown as a benzene ring in formula (2) may be changed to an R-substituted pyrrole ring, furan ring, thiophene ring or other nitrogen-, oxygen- or sulfur-containing heteroaryl ring. In addition, when adjacent groups are present on ring c (R ⁴ and R ⁵ in the above formula), they are bonded together to form a heteroaryl ring (an R-substituted indole ring, benzofuran ring or benzothiophene ring in the above formula), and the formed ring may be further substituted (indicated by n Rs) as described above.
In addition, there are the following variations:

The same applies when other positions are replaced with "-N(-R)-", "-O-" or "-S-" or when ring a or ring b is changed.

In the above explanation of formula (2-1) and formula (2-2), ring a, ring b, and ring c are described as benzene rings, but the same applies when ring a to ring c are changed to a nitrogen-containing heteroaryl ring (6-membered or 5-membered ring) or an oxygen-sulfur-containing heteroaryl ring (5-membered ring).

Examples of the "aryl ring" which is ring A, ring B and ring C in general formula (1) include aryl rings having 6 to 30 carbon atoms, preferably aryl rings having 6 to 16 carbon atoms, more preferably aryl rings having 6 to 12 carbon atoms, and particularly preferably aryl rings having 6 to 10 carbon atoms. This "aryl ring" corresponds to "an aryl ring formed together with ring a, ring b or ring c by bonding adjacent groups among R ¹ to R ¹¹ " defined in general formula (2), and since ring a (or ring b or ring c) is already composed of a benzene ring having 6 carbon atoms, the lower limit of the carbon number is 9, which is the total carbon number of the fused rings fused with a 5-membered ring.

Specific examples of "aryl rings" include a monocyclic benzene ring, a bicyclic ...

Examples of the "heteroaryl ring" which is the ring A, ring B and ring C in general formula (1) include heteroaryl rings having 2 to 30 carbon atoms, preferably heteroaryl rings having 2 to 25 carbon atoms, more preferably heteroaryl rings having 2 to 20 carbon atoms, even more preferably heteroaryl rings having 2 to 15 carbon atoms, and particularly preferably heteroaryl rings having 2 to 10 carbon atoms. Examples of the "heteroaryl ring" include heterocycles containing 1 to 5 heteroatoms selected from oxygen, sulfur and nitrogen as ring-constituting atoms other than carbon. Note that this "heteroaryl ring" corresponds to the "heteroaryl ring formed together with the ring a, ring b or ring c by bonding adjacent groups among R ¹ to R ¹¹ " defined in general formula (2), and since the ring a (or ring b or ring c) is already composed of a benzene ring having 6 carbon atoms, the total carbon number of the fused rings to which the 5-membered ring is fused is 6, which is the lower limit of the carbon number.

Specific examples of the "heteroaryl ring" include a pyrrole ring, an oxazole ring, an isoxazole ring, a thiazole ring, an isothiazole ring, an imidazole ring, an oxadiazole ring, a thiadiazole ring, a triazole ring, a tetrazole ring, a pyrazole ring, a pyridine ring, a pyrimidine ring, a pyridazine ring, a pyrazine ring, a triazine ring, an indole ring, an isoindole ring, a 1H-indazole ring, a benzimidazole ring, a benzoxazole ring, a benzothiazole ring, a 1H-benzotriazole ring, a quinoline ring, an isoquinoline ring, a cinnoline ring, a quinazoline ring, a quinoxaline ring, a phenanthroline ring, a phthalazine ring, a naphthyridine ring, a purine ring, a pteridine ring, a carbazole ... Examples include a benzol ring, an acridine ring, a phenoxathiin ring, a phenoxazine ring, a phenothiazine ring, a phenazine ring, a phenazasiline ring, an indolizine ring, a furan ring, a benzofuran ring, an isobenzofuran ring, a dibenzofuran ring, a naphthobenzofuran ring, a thiophene ring, a benzothiophene ring, an isobenzothiophene ring, a dibenzothiophene ring, a naphthobenzothiophene ring, a benzophosphole ring, a dibenzophosphole ring, a benzophosphole oxide ring, a dibenzophosphole oxide ring, a furazan ring, a thianthrene ring, an indolocarbazole ring, a benzoindolocarbazole ring, a benzobenzoindolocarbazole ring, an imidazoline ring, and an oxazoline ring.

At least one hydrogen atom in the above "aryl ring" or "heteroaryl ring" may be substituted with a first substituent, which is a substituted or unsubstituted "aryl", a substituted or unsubstituted "heteroaryl", a substituted or unsubstituted "diarylamino", a substituted or unsubstituted "diheteroarylamino", a substituted or unsubstituted "arylheteroarylamino", a substituted or unsubstituted "diarylboryl (two aryls may be bonded via a single bond or a linking group)", a substituted or unsubstituted "alkyl", a substituted or unsubstituted "cycloalkyl", a substituted or unsubstituted "alkoxy", a substituted or unsubstituted "aryloxy", or a substituted "silyl". Examples of the first substituents, the "aryl" or "heteroaryl" in the "diarylamino", the heteroaryl in the "diheteroarylamino", the aryl and heteroaryl in the "arylheteroarylamino", the aryl in the "diarylboryl", and the aryl in the "aryloxy" include monovalent groups represented by removing any one hydrogen atom from the above-mentioned "aryl ring" or "heteroaryl ring".

The "alkyl" as the first substituent 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. An alkyl having 1 to 18 carbon atoms (branched alkyl having 3 to 18 carbon atoms) is preferred, an alkyl having 1 to 12 carbon atoms (branched alkyl having 3 to 12 carbon atoms) is more preferred, an alkyl having 1 to 6 carbon atoms (branched alkyl having 3 to 6 carbon atoms) is even more preferred, an alkyl having 1 to 5 carbon atoms (branched alkyl having 3 to 5 carbon atoms) is particularly preferred, and an alkyl having 1 to 4 carbon atoms (branched alkyl having 3 to 4 carbon atoms) is most preferred.

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

Examples of "cycloalkyl" as the first substituent include cycloalkyl having 3 to 24 carbon atoms, cycloalkyl having 3 to 20 carbon atoms, cycloalkyl having 3 to 16 carbon atoms, cycloalkyl having 3 to 14 carbon atoms, cycloalkyl having 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, and cycloalkyl having 5 carbon atoms.

Specific examples of cycloalkyl include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl, and alkyl (especially methyl) substituted derivatives of these having 1 to 5 or 1 to 4 carbon atoms, as well as norbornenyl, bicyclo[1.0.1]butyl, bicyclo[1.1.1]pentyl, bicyclo[2.0.1]pentyl, bicyclo[1.2.1]hexyl, bicyclo[3.0.1]hexyl, bicyclo[2.1.2]heptyl, bicyclo[2.2.2]octyl, adamantyl, diamantyl, decahydronaphthalenyl, and decahydroazulenyl.

Also, examples of the "alkoxy" as the first substituent include linear alkoxy having 1 to 24 carbon atoms or branched alkoxy having 3 to 24 carbon atoms. An alkoxy having 1 to 18 carbon atoms (branched alkoxy having 3 to 18 carbon atoms) is preferred, an alkoxy having 1 to 12 carbon atoms (branched alkoxy having 3 to 12 carbon atoms) is more preferred, an alkoxy having 1 to 6 carbon atoms (branched alkoxy having 3 to 6 carbon atoms) is even more preferred, an alkoxy having 1 to 5 carbon atoms (branched alkoxy having 3 to 5 carbon atoms) is particularly preferred, and an alkoxy having 1 to 4 carbon atoms (branched alkoxy having 3 to 4 carbon atoms) is most preferred.

Specific examples of alkoxy include methoxy, ethoxy, propoxy, isopropoxy, n-butoxy, isobutoxy, s-butoxy, t-butoxy, t-amyloxy, n-pentyloxy, isopentyloxy, neopentyloxy, t-pentyloxy, n-hexyloxy, 1-methylpentyloxy, 3,3-dimethylbutoxy, 2-ethylbutoxy, n-heptyloxy, 1-methylhexyloxy, n-octyloxy, t-octyloxy, 1-methylheptyloxy, 2-ethylhexyloxy, Examples include oxy, 2-propylpentyloxy, n-nonyloxy, 2,2-dimethylheptyloxy, 2,6-dimethyl-4-heptyloxy, 3,5,5-trimethylhexyloxy, n-decyloxy, n-undecyloxy, 1-methyldecyloxy, n-dodecyloxy, n-tridecyloxy, 1-hexylheptyloxy, n-tetradecyloxy, n-pentadecyloxy, n-hexadecyloxy, n-heptadecyloxy, n-octadecyloxy, and n-eicosyloxy.

The "substituted silyl" as the first substituent includes, for example, triarylsilyl, trialkylsilyl, tricycloalkylsilyl, dialkylcycloalkylsilyl, and alkyldicycloalkylsilyl, which are silyl substituted with at least one of aryl, alkyl, and cycloalkyl.

The "triarylsilyl" includes a group in which three hydrogen atoms in a silyl group are each independently replaced by an aryl, and the aryl can be any of the groups described as the "aryl" in the first substituent above.
Specific "triarylsilyl" includes, for example, triphenylsilyl, diphenylmononaphthylsilyl, monophenyldinaphthylsilyl, trinaphthylsilyl, and the like.

An example of a "trialkylsilyl" is a group in which three hydrogen atoms in a silyl group are each independently replaced with an alkyl, and the alkyl can be any of the groups described above as the "alkyl" in the first substituent. Preferred alkyl groups for substitution are those having 1 to 4 carbon atoms, and specific examples include methyl, ethyl, propyl, i-propyl, butyl, sec-butyl, t-butyl, and cyclobutyl.

Specific examples of trialkylsilyl include trimethylsilyl, triethylsilyl, tripropylsilyl, tri-i-propylsilyl, tributylsilyl, trisec-butylsilyl, tri-t-butylsilyl, ethyldimethylsilyl, propyldimethylsilyl, i-propyldimethylsilyl, butyldimethylsilyl, sec-butyldimethylsilyl, t-butyldimethylsilyl, methyldiethylsilyl, propyldiethylsilyl, i-propyldiethylsilyl, butyldiethylsilyl, sec-butyldiethylsilyl, t-butyldiethylsilyl, methyldipropylsilyl, ethyldipropylsilyl, butyldipropylsilyl, sec-butyldipropylsilyl, t-butyldipropylsilyl, methyldi-i-propylsilyl, ethyldi-i-propylsilyl, butyldi-i-propylsilyl, sec-butyldi-i-propylsilyl, and t-butyldi-i-propylsilyl.

"Tricycloalkylsilyl" refers to a group in which three hydrogen atoms in a silyl group are each independently replaced with a cycloalkyl, and the cycloalkyl can be cited as the group described as "cycloalkyl" in the first substituent above. Preferred cycloalkyl groups for substitution are cycloalkyl groups having 5 to 10 carbon atoms, and specific examples include cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl, bicyclo[1.1.1]pentyl, bicyclo[2.0.1]pentyl, bicyclo[1.2.1]hexyl, bicyclo[3.0.1]hexyl, bicyclo[2.1.2]heptyl, bicyclo[2.2.2]octyl, adamantyl, decahydronaphthalenyl, and decahydroazulenyl.

Specific examples of tricycloalkylsilyl include tricyclopentylsilyl and tricyclohexylsilyl.

Specific examples of dialkylcycloalkylsilyl substituted with two alkyls and one cycloalkyl, and alkyldicycloalkylsilyl substituted with one alkyl and two cycloalkyls include silyl substituted with a group selected from the specific alkyls and cycloalkyls mentioned above.

As for the "aryl" in the "diarylboryl" of the first substituent, the above explanation of the aryl can be cited. Furthermore, the two aryls may be bonded via a single bond or a linking group (for example, >C(-R) ₂ , >O, >S, or >N-R). Here, R in >C(-R) ₂ and >N-R is aryl, heteroaryl, diarylamino, alkyl, cycloalkyl, alkoxy, or aryloxy (the above, the first substituent), and the first substituent may be further substituted with aryl, heteroaryl, alkyl, or cycloalkyl (the above, the second substituent), and as specific examples of these groups, the above explanation of aryl, heteroaryl, diarylamino, alkyl, cycloalkyl, alkoxy, or aryloxy as the first substituent can be cited.

In general formula (2), any "-C(-R)=C(-R)-" (where R is R ¹ to R ¹¹ in formula (2)) may be substituted with "-N(-R)-", where R is aryl, alkyl, or cycloalkyl, and examples of this aryl, alkyl, or cycloalkyl include the groups described above. In particular, aryl having 6 to 10 carbon atoms (e.g., phenyl, naphthyl, etc.), alkyl having 1 to 5 or 1 to 4 carbon atoms (e.g., methyl, ethyl, etc.), or cycloalkyl having 5 to 10 carbon atoms (preferably cyclohexyl or adamantyl) are preferred.

As described above, the first substituents, substituted or unsubstituted "aryl", substituted or unsubstituted "heteroaryl", substituted or unsubstituted "diarylamino", substituted or unsubstituted "diheteroarylamino", substituted or unsubstituted "arylheteroarylamino", substituted or unsubstituted "diarylboryl (two aryls may be bonded via a single bond or a linking group)", substituted or unsubstituted "alkyl", substituted or unsubstituted "cycloalkyl", substituted or unsubstituted "alkoxy", substituted or unsubstituted "aryloxy", or substituted "silyl", may have at least one hydrogen atom substituted with a second substituent. Examples of the second substituent include aryl, heteroaryl, alkyl, or cycloalkyl, and specific examples thereof can be found in the above-mentioned description of the monovalent group represented by removing any one hydrogen atom from the "aryl ring" or "heteroaryl ring", and the description of "alkyl" or "cycloalkyl" as the first substituent. In addition, the aryl and heteroaryl as the second substituent also include structures in which at least one hydrogen atom in the aryl and heteroaryl as the second substituent is replaced with an aryl such as phenyl (specific examples are the groups described above), an alkyl such as methyl (specific examples are the groups described above), or a cycloalkyl such as cyclohexyl (specific examples are the groups described above). As an example, when the second substituent is a carbazolyl group, a carbazolyl group in which at least one hydrogen atom at the 9-position is replaced with an aryl such as phenyl, an alkyl such as methyl, or a cycloalkyl such as cyclohexyl is also included in the heteroaryl as the second substituent.

In the general formula (2), the aryl, heteroaryl, aryl of diarylamino, heteroaryl of diheteroarylamino, aryl and heteroaryl of arylheteroarylamino, aryl of diarylboryl, or aryl of aryloxy in R ¹ to R ¹¹ may be a monovalent group represented by removing any one hydrogen atom from the "aryl ring" or "heteroaryl ring" described in the general formula (1). In addition, for the alkyl, cycloalkyl, or alkoxy in R ¹ to R ¹¹ , the explanation of "alkyl", "cycloalkyl", or "alkoxy" as the first substituent in the explanation of the general formula (1) above may be referred to. In addition, for the triarylsilyl, trialkylsilyl, tricycloalkylsilyl, dialkylcycloalkylsilyl, or alkyldicycloalkylsilyl in R ¹ to R ¹¹ , the explanation of "substituted silyl" as the first substituent in the explanation of the general formula (1) above may be referred to. Furthermore, the same applies to the aryl, heteroaryl, alkyl, or cycloalkyl as a substituent to these groups. In addition, when adjacent groups among R ¹ to R ¹¹ are bonded to each other to form an aryl ring or a heteroaryl ring together with ring a, ring b or ring c, the same applies to the substituents on these rings, such as aryl, heteroaryl, diarylamino, diheteroarylamino, arylheteroarylamino, diarylboryl (the two aryls may be bonded via a single bond or a linking group), alkyl, cycloalkyl, alkoxy, aryloxy, triarylsilyl, trialkylsilyl, tricycloalkylsilyl, dialkylcycloalkylsilyl or alkyldicycloalkylsilyl, and the further substituents, such as aryl, heteroaryl, alkyl or cycloalkyl.

Specifically, the emission wavelength can be adjusted by the steric hindrance, electron donating property and electron withdrawing property of the structure of the first substituent, and is preferably a group represented by the following structural formula, more preferably methyl, t-butyl, phenyl, o-tolyl, p-tolyl, 2,4-xylyl, 2,5-xylyl, 2,6-xylyl, 2,4,6-mesityl, diphenylamino, di-p-tolylamino, bis(p-(t-butyl)phenyl)amino, carbazolyl, 3,6-dimethylcarbazolyl, 3,6-di-t-butylcarbazolyl and phenoxy, and even more preferably methyl, t-butyl, phenyl, o-tolyl, 2,6-xylyl, 2,4,6-mesityl, diphenylamino, di-p-tolylamino, bis(p-(t-butyl)phenyl)amino, carbazolyl, 3,6-dimethylcarbazolyl and 3,6-di-t-butylcarbazolyl. From the viewpoint of ease of synthesis, a larger steric hindrance is preferred for selective synthesis, and specifically, t-butyl, o-tolyl, p-tolyl, 2,4-xylyl, 2,5-xylyl, 2,6-xylyl, 2,4,6-mesityl, di-p-tolylamino, bis(p-(t-butyl)phenyl)amino, 3,6-dimethylcarbazolyl, and 3,6-di-t-butylcarbazolyl are preferred.

In the following structural formulas, "Me" represents methyl, "tBu" represents t-butyl, "tAm" represents t-amyl, "tOct" represents t-octyl, and * represents the bonding position.

The present invention also relates to a multimer of a polycyclic aromatic compound having a plurality of unit structures represented by general formula (1), preferably a multimer of a polycyclic aromatic compound having a plurality of unit structures represented by general formula (2). The multimer is preferably a dimer to a hexamer, more preferably a dimer to a trimer, and particularly preferably a dimer. The multimer may have a plurality of the above unit structures in one compound. For example, the unit structures may be linked together by a linking group such as a single bond, an alkylene group having 1 to 3 carbon atoms, a phenylene group, or a naphthylene group (linked multimer). In addition, the unit structures may be linked together so that any ring (ring A, ring B or ring C, ring a, ring b or ring c) contained in the unit structure is shared by multiple unit structures (ring-shared multimer). Alternatively, the unit structures may be linked together so that any ring (ring A, ring B or ring C, ring a, ring b or ring c) is condensed (ring-condensed multimer). However, ring-shared multimers and ring-condensed multimers are preferred, and ring-shared multimers are more preferred.

Examples of such multimers include multimer compounds represented by the following formulas (2-4), (2-4-1), (2-4-2), (2-5-1) to (2-5-4), or (2-6). The multimer compound represented by the following formula (2-4) is a multimer compound (ring-sharing multimer) having a plurality of unit structures represented by general formula (2) in one compound, with the benzene ring being the a-ring shared, when described in terms of general formula (2). The multimer compound represented by the following formula (2-4-1) is a multimer compound (ring-sharing multimer) having two unit structures represented by general formula (2) in one compound, with the benzene ring being the a-ring shared, when described in terms of general formula (2). Moreover, the multimeric compound represented by the following formula (2-4-2) is a multimeric compound (ring-sharing type multimer) having three unit structures represented by the general formula (2) in one compound, with the benzene ring being the a-ring being shared, when described in the general formula (2). Moreover, the multimeric compound represented by any one of the following formulas (2-5-1) to (2-5-4) is a multimeric compound (ring-sharing type multimer) having multiple unit structures represented by the general formula (2) in one compound, with the benzene ring being the b-ring (or the c-ring) being shared, when described in the general formula (2). Moreover, the multimeric compound represented by the following formula (2-6) is a multimeric compound (ring-condensed type multimer) having multiple unit structures represented by the general formula (2) in one compound, with the benzene ring being the b-ring (or the a-ring, the c-ring) of a certain unit structure condensed with the benzene ring being the b-ring (or the a-ring, the c-ring) of a certain unit structure.

The multimeric compound may be a multimer in which a multimerization form represented by formula (2-4), formula (2-4-1) or formula (2-4-2) is combined with a multimerization form represented by any one of formulas (2-5-1) to (2-5-4) or formula (2-6), a multimer in which a multimerization form represented by any one of formulas (2-5-1) to (2-5-4) is combined with a multimerization form represented by formula (2-6), or a multimer in which a multimerization form represented by formula (2-4), formula (2-4-1) or formula (2-4-2), a multimerization form represented by any one of formulas (2-5-1) to (2-5-4) and a multimerization form represented by formula (2-6).

上記式（ＢｉＮ）中、Ｄ環は少なくとも１つのＮを含むヘテロアリール環であり、Ｅ環は少なくとも１つのＮを含む芳香族環または非芳香族環であり、Ｄ環とＥ環との間に芳香族または非芳香族の縮合環が形成されていてもよく、また、これらの環における少なくとも１つの水素は置換されていてもよい。式（ＢｉＮ）における＊の位置で、連結基を介して、一般式（１）または式（２）の構造に置換する。 The polycyclic aromatic compound of the present invention has a group represented by the following general formula (BiN) via a linking group.

In the above formula (BiN), ring D is a heteroaryl ring containing at least one N, ring E is an aromatic or non-aromatic ring containing at least one N, an aromatic or non-aromatic condensed ring may be formed between ring D and ring E, and at least one hydrogen in these rings may be substituted. At the position of * in formula (BiN), it is substituted with a structure of general formula (1) or formula (2) via a linking group.

The "heteroaryl ring containing at least one N" which is the D ring is not particularly limited as long as it is a ring having an "-N=C<" group within the ring, but examples thereof include rings having 2 to 30 carbon atoms, preferably rings having 2 to 25 carbon atoms, more preferably rings having 2 to 20 carbon atoms, even more preferably rings having 2 to 15 carbon atoms, and particularly preferably rings having 2 to 10 carbon atoms. Examples of heteroaryl rings include heterocycles containing carbon and nitrogen as ring-constituting atoms, and additionally containing 1 to 5 heteroatoms selected from oxygen, sulfur, and nitrogen.

Specific examples of "heteroaryl rings containing at least one N" include an oxazole ring, an isoxazole ring, a thiazole ring, an isothiazole ring, an imidazole ring, an oxadiazole ring, a thiadiazole ring, a triazole ring, a tetrazole ring, a pyrazole ring, a pyridine ring, a pyrimidine ring, a pyridazine ring, a pyrazine ring, a triazine ring, a 1H-indazole ring, a benzimidazole ring, a benzoxazole ring, a benzothiazole ring, a quinoline ring, an isoquinoline ring, a quinazoline ring, a quinoxaline ring, a phthalazine ring, a naphthyridine ring, a purine ring, a pteridine ring, or a furazan ring.

The "aromatic or non-aromatic ring containing at least one N" which is ring E is not particularly limited as long as it is a ring having an "-N=C<" group within the ring, but examples thereof include rings having 2 to 30 carbon atoms, preferably rings having 2 to 25 carbon atoms, more preferably rings having 2 to 20 carbon atoms, even more preferably rings having 2 to 15 carbon atoms, and particularly preferably rings having 2 to 10 carbon atoms. Examples of aromatic or non-aromatic rings include heterocycles containing carbon and nitrogen as ring-constituting atoms, and additionally containing 1 to 5 heteroatoms selected from oxygen, sulfur, and nitrogen.

Specific examples of "aromatic rings containing at least one N" include an oxazole ring, an isoxazole ring, a thiazole ring, an isothiazole ring, an imidazole ring, an oxadiazole ring, a thiadiazole ring, a triazole ring, a tetrazole ring, a pyrazole ring, a pyridine ring, a pyrimidine ring, a pyridazine ring, a pyrazine ring, a triazine ring, a 1H-indazole ring, a benzimidazole ring, a benzoxazole ring, a benzothiazole ring, a quinoline ring, an isoquinoline ring, a quinazoline ring, a quinoxaline ring, a phthalazine ring, a naphthyridine ring, a purine ring, a pteridine ring, or a furazan ring.

Examples of "non-aromatic rings containing at least one N" include rings in which the above-mentioned aromatic rings have lost their aromaticity, such as rings in which an unsaturated bond in an aromatic ring has been saturated by bonding with a substituent. One example is a ring formed by saturating an unsaturated bond in an oxazole ring as shown below, and the same explanation can be applied not only to oxazole rings but also to the other aromatic rings mentioned above. "Me" in the following structural formula is a methyl group.

In addition, the aromatic or non-aromatic fused ring formed between the D ring and the E ring may be, for example, a ring having 2 to 15 carbon atoms, preferably a ring having 2 to 10 carbon atoms, specifically, a tetrahydrobenzene ring, a dihydrobenzene ring, a cyclopentane ring, a cyclohexane ring, etc. Specific structures are exemplified below. The definition of each symbol in the following structural formula is the same as the definition of each symbol in the general formula (BiN).

At least one hydrogen atom in the D ring, the E ring and the fused ring may be substituted with an aryl, a heteroaryl, a diarylamino, a diheteroarylamino, an arylheteroarylamino, a diarylboryl (the two aryls may be bonded via a single bond or a linking group), an alkyl, a cycloalkyl, an alkoxy, an aryloxy, a trialkylsilyl, a tricycloalkylsilyl, a dialkylcycloalkylsilyl or an alkyldicycloalkylsilyl (all of these are first substituents), and at least one hydrogen atom in these may be substituted with an aryl, a heteroaryl, an alkyl or a cycloalkyl (all of these are second substituents).
For details of these groups, the explanations of the first and second substituents in the general formulae (1) and (2) can be cited.

Specific examples of the group represented by formula (BiN) are shown below.

At least one hydrogen atom in ring A, ring B and ring C in formula (1) is substituted with a group represented by the following general formula (BiN) via a linking group. At least one of R ¹ to R ¹¹ in formula (2) is a group represented by the following general formula (BiN) via a linking group, or at least one hydrogen atom in the formed aryl ring or heteroaryl ring (a ring, b ring or c ring formed by bonding adjacent groups among R ¹ to R ¹¹ ) is substituted with a group represented by the formula (BiN) via a linking group.

The linking group is, for example, a single bond, arylene, heteroarylene, alkylene, alkenylene, alkynylene, -O-, -S-, >N-R, or a combination thereof.
The arylene and heteroarylene include divalent groups represented by removing any two hydrogen atoms from the "aryl ring" and "heteroaryl ring" in general formula (1) and formula (2).
The alkylene includes a divalent group represented by removing any one hydrogen atom from the "alkyl" as the first substituent in general formula (1) and formula (2). In addition, alkenylene and alkynylene are groups represented by replacing any "-CH ₂ -CH ₂ -" in the alkylene with "-CH=CH-" or "-C≡C-", respectively.

The R in >N-R in the linking group is aryl, heteroaryl, alkyl, or cycloalkyl. For details of these groups, the explanations of the first and second substituents in general formula (1) and formula (2) can be cited.

At least one hydrogen atom in the linking group may be substituted with an aryl, heteroaryl, alkyl, or cycloalkyl. For details of these groups, the explanations of the first and second substituents in general formula (1) and formula (2) can be cited.

Specific examples of the linking group include a single bond, phenylene, naphthylene, alkylene having 1 to 4 carbon atoms, -O-, combinations thereof, and groups in which at least one hydrogen atom is substituted with an alkyl having 1 to 4 carbon atoms. Among these, a single bond, phenylene, naphthylene, methylene, ethylene, -OCH ₂ CH ₂ -, -CH ₂ CH ₂ O-, or -OCH ₂ CH ₂ O- is preferred, with a single bond being more preferred.

The bonding position of the group represented by formula (BiN) may be any position of ring A, ring B or ring C in formula (1), specifically, any position of R ¹ to R ¹¹ in formula (2), or any position of the formed aryl ring or heteroaryl ring (a ring, b ring or c ring formed by bonding adjacent groups among R ¹ to R ¹¹ ), but is preferably any of R ¹ and R ³ , R ⁴ and R ¹¹ , R 5 and R ¹⁰ , R ⁶ and R ⁹ , R ² , ^{R 4 and R 11 ,} R ² , R ⁵ and R ¹⁰ , or R ² , R ⁶ and R ⁹ .

In addition, all or a part of the hydrogen atoms in the chemical structure of the polycyclic aromatic compound and its multimer represented by general formula (1) or (2) may be substituted with cyano, halogen, or deuterium. For example, in formula (1), hydrogen atoms in rings A, B, and C (rings A to C are aryl or heteroaryl rings), substituents on rings A to C, and the group represented by formula (BiN) may be substituted with cyano, halogen, or deuterium. Among these, examples include embodiments in which all or a part of the hydrogen atoms in the aryl or heteroaryl are substituted with cyano, halogen, or deuterium. The halogen is fluorine, chlorine, bromine, or iodine, preferably fluorine, chlorine, or bromine, and more preferably fluorine or chlorine.

In addition, at least one of the aromatic rings and heteroaromatic rings in the chemical structure of the polycyclic aromatic compound represented by general formula (1) or (2) and its multimer may be condensed with at least one cycloalkane.

For example, at least one of the aryl and heteroaryl rings which are the A ring, the B ring, the C ring, the a ring, the b ring, and the c ring, the aryl group (the aryl group portion in an aryl, diarylamino, an arylheteroarylamino, a diarylboryl, an aryloxy, or a triarylsilyl) and the heteroaryl group (the heteroaryl portion in a heteroaryl, a diheteroarylamino, or an arylheteroarylamino) as the first and second substituents on the A ring to the C ring, and the aryl group (similar to the above) and the heteroaryl group (similar to the above) as the first and second substituents on the a ring to the c ring may be condensed with at least one cycloalkane.

Preferably, at least one of the aryl and heteroaryl rings, which are the A ring, the B ring, the C ring, the a ring, the b ring, and the c ring, the aryl group (the aryl group portion in the aryl, diarylamino, diarylboryl, or aryloxy) and the heteroaryl group (the heteroaryl portion in the heteroaryl or diheteroarylamino) as the first substituent on the A ring to the C ring, and the aryl group (similar to the above) and the heteroaryl group (similar to the above) as the first substituent on the a ring to the c ring may be condensed with at least one cycloalkane.

More preferably, at least one of the aryl rings, which are ring A, ring B, ring C, ring a, ring b, and ring c, the aryl group (aryl group portion in aryl or diarylamino) and heteroaryl group (heteroaryl portion in heteroaryl) as the first substituent on ring A to ring C, and the aryl group (similar to above) and heteroaryl group (similar to above) as the first substituent on ring a to ring c may be condensed with at least one cycloalkane.

More preferably, at least one of the aryl rings A, B, C, a, b and c, the aryl group as the first substituent on rings A to C (the aryl group portion in aryl or diarylamino), and the aryl group as the first substituent on rings a to c (similar to above) may be condensed with at least one cycloalkane.

Examples of "cycloalkanes" include cycloalkanes with 3 to 24 carbon atoms, cycloalkanes with 3 to 20 carbon atoms, cycloalkanes with 3 to 16 carbon atoms, cycloalkanes with 3 to 14 carbon atoms, cycloalkanes with 5 to 10 carbon atoms, cycloalkanes with 5 to 8 carbon atoms, cycloalkanes with 5 to 6 carbon atoms, and cycloalkanes with 5 carbon atoms.

Specific examples of cycloalkanes include cyclopropane, cyclobutane, cyclopentane, cyclohexane, cycloheptane, cyclooctane, cyclononane, cyclodecane, norbornene, bicyclo[1.0.1]butane, bicyclo[1.1.1]pentane, bicyclo[2.0.1]pentane, bicyclo[1.2.1]hexane, bicyclo[3.0.1]hexane, bicyclo[2.1.2]heptane, bicyclo[2.2.2]octane, adamantane, diamantane, decahydronaphthalene, and decahydroazulene, as well as alkyl (especially methyl) substituted, halogen (especially fluorine) substituted, and deuterium substituted derivatives of these having 1 to 5 carbon atoms.

Among these, for example, as shown in the following structural formula, a structure in which at least one hydrogen atom is substituted on the carbon atom at the α-position of a cycloalkane (a carbon atom at a position adjacent to the carbon atom at the condensation site in a cycloalkane fused to an aromatic ring or heteroaromatic ring) is preferred, a structure in which two hydrogen atoms are substituted on the carbon atom at the α-position is more preferred, and a structure in which a total of four hydrogen atoms are substituted on the two carbon atoms at the α-position is even more preferred. Examples of this substituent include an alkyl (particularly methyl) substituent having 1 to 5 carbon atoms, a halogen (particularly fluorine) substituent, and a deuterium substituent.

The number of cycloalkanes fused to one aromatic ring or heteroaromatic ring is preferably 1 to 3, more preferably 1 or 2, and even more preferably 1. For example, an example in which one or more cycloalkanes are fused to one benzene ring (phenyl group) is shown below. In each structural formula, * means a benzene ring contained in the skeletal structure of the compound when it is a benzene ring, and means a bond substituting the skeletal structure of the compound when it is a phenyl group. Cycloalkanes fused as in formula (Cy-1-4) and formula (Cy-2-4) may be condensed together. The same applies even if the condensed ring (group) is an aromatic ring or heteroaromatic ring other than a benzene ring (phenyl group), or even if the condensed cycloalkane is a cycloalkane other than cyclopentane or cyclohexane.

At least one -CH ₂ - in a cycloalkane may be substituted with -O-. However, when multiple -CH ₂ - are substituted with -O-, adjacent -CH ₂ - are not substituted with -O-. For example, examples in which one or multiple -CH ₂ - in a cycloalkane fused to one benzene ring (phenyl group) are substituted with -O- are shown below. In each structural formula, * means a benzene ring contained in the skeletal structure of the compound when it is a benzene ring, and means a bond substituting the skeletal structure of the compound when it is a phenyl group. The same applies when the fused ring (group) is an aromatic ring or heteroaromatic ring other than a benzene ring (phenyl group) or when the fused cycloalkane is a cycloalkane other than cyclopentane or cyclohexane.

At least one hydrogen atom in the cycloalkane may be substituted. Examples of the substituent include aryl, heteroaryl, diarylamino, diheteroarylamino, arylheteroarylamino, diarylboryl (two aryls may be bonded via a single bond or a linking group), alkyl, cycloalkyl, alkoxy, aryloxy, substituted silyl, deuterium, cyano, or halogen. For details of these, the description of the first substituent can be cited. Among these substituents, alkyl (e.g., alkyl having 1 to 6 carbon atoms), cycloalkyl (e.g., cycloalkyl having 3 to 14 carbon atoms), halogen (e.g., fluorine), and deuterium are preferred. In addition, when cycloalkyl is substituted, it may be a substitution form that forms a spiro structure. For example, an example in which a spiro structure is formed in a cycloalkane condensed to one benzene ring (phenyl group) is shown below. In each structural formula, * means that in the case of a benzene ring, it is a benzene ring included in the skeletal structure of the compound, and in the case of a phenyl group, it means a bond that substitutes in the skeletal structure of the compound.

Other forms of cycloalkane condensation include polycyclic aromatic compounds and multimers thereof represented by general formula (1) or (2) substituted with, for example, a diarylamino group condensed with a cycloalkane (condensed to the aryl group portion), a carbazolyl group condensed with a cycloalkane (condensed to the benzene ring portion), or a benzocarbazolyl group condensed with a cycloalkane (condensed to the benzene ring portion). Examples of the "diarylamino group" include the groups described above as the "first substituent."

Further, as more specific examples, there can be mentioned examples in which ^R2 in the polycyclic aromatic compound represented by general formula (2) and its multimer is a diarylamino group condensed with a cycloalkane (condensed to the aryl group portion) or a carbazolyl group condensed with a cycloalkane (condensed to the benzene ring portion).

An example of this is a polycyclic aromatic compound represented by the following general formula (2-Cy), or a multimer of a polycyclic aromatic compound having a plurality of structures represented by the following general formula (2-Cy). In the structural formula below, Cy is a cycloalkane, n is an integer of 1 to 3 (preferably 1), and "=(Cy)n" means that n cycloalkanes are condensed at any position of the structure to be condensed (in the structural formula below, n cycloalkanes are condensed to a benzene ring (phenyl group)), and the definition of each symbol in the structural formula is the same as that of each symbol in general formula (2).

Specific examples include compounds represented by the following formulas. In the formulas below, "Cy" represents a cycloalkane, and n is independently 0 to the maximum number that can be condensed (however, all n's cannot be 0), preferably 0 to 2 (however, all n's cannot be 0), and more preferably 1, and "=(Cy)n" means that n cycloalkanes are condensed at any position of the structure to be condensed (for example, in the formula "2-Cy-(1)" below, n cycloalkanes are condensed at any position of each benzene ring). In addition, in the structural formulas below, "OPh" represents a phenoxy group, "Me" represents a methyl group, and each compound may be substituted with the first and second substituents described above, and at least one of the first substituents is a group represented by the above formula (BiN) via a linking group, or at least one hydrogen atom in the formed aryl or heteroaryl ring is substituted with a group represented by the formula (BiN) via a linking group.

Specific examples of the polycyclic aromatic compounds of the present invention include compounds represented by the following structural formulas. Note that the methyl group (Me) is omitted in the structural formula.

2. Method for Producing Polycyclic Aromatic Compounds and Multimers Thereof The polycyclic aromatic compounds represented by general formula (1) or (2) can be produced according to the methods described in many publicly known documents, including WO 2015/102118.

Basically, an intermediate is produced by first bonding the A ring (a-ring), B ring (b-ring), and C ring (c-ring) with a bonding group (a group containing O (oxygen)) (first reaction), and then the A ring (a-ring), B ring (b-ring), and C ring (c-ring) with a bonding group (a group containing the central element B (boron)) to produce the final product (second reaction). In the first reaction, for example, if it is an etherification reaction, general reactions such as nucleophilic substitution reaction and Ullmann reaction can be used. In addition, in the second reaction, a tandem hetero Friedel-Crafts reaction (sequential aromatic electrophilic substitution reaction, the same applies below) can be used.

In addition, by using a cyanated, halogenated or deuterated raw material somewhere in these reaction steps, or by adding a step of cyanation, halogenation or deuteration, it is possible to produce a compound in which the desired position is cyanated, halogenated or deuterated. Similarly, by using a raw material substituted with a group represented by the general formula (BiN) somewhere in the reaction steps, or by adding a step of substituting this group, it is possible to produce the compound of the present invention.

As shown in the following schemes (1) and (2), the second reaction is a reaction to introduce a central element B (boron) that bonds the A ring (a ring), the B ring (b ring), and the C ring (c ring). First, the hydrogen atom between the two elements "O (oxygen)" is orthometalated with n-butyllithium, sec-butyllithium, t-butyllithium, or the like. Next, boron trichloride, boron tribromide, or the like is added to perform lithium-boron metal exchange, and then a tandem boron-Friedel-Crafts reaction is carried out by adding a Bronsted base such as N,N-diisopropylethylamine to obtain the target product. In the second reaction, a Lewis acid such as aluminum trichloride may be added to promote the reaction. The symbols in the structural formulas in the following schemes (1) to (5) are defined as above.

The above schemes (1) and (2) mainly show the method for producing the polycyclic aromatic compounds represented by the general formulas (1) and (2), but the multimers can be produced by using intermediates having multiple A rings (a rings), B rings (b rings) and C rings (c rings). Details are explained in the following schemes (3) to (5). In this case, the target product can be obtained by doubling or tripling the amount of the reagent such as butyllithium used.

Specific examples of solvents used in the above reactions include t-butylbenzene and xylene.

Orthometalation reagents include alkyllithium such as methyllithium, n-butyllithium, sec-butyllithium, and t-butyllithium, and organic alkali compounds such as lithium diisopropylamide, lithium tetramethylpiperidide, lithium hexamethyldisilazide, and potassium hexamethyldisilazide.

Examples of metal exchange reagents for the metal-center element "B (boron)" include boron halides such as boron trifluoride, boron trichloride, boron tribromide, and boron triiodide, boron amination halides such as CIPN( _NEt2 ) ₂ , boron alkoxylates, and boron aryloxylates.

Examples of Bronsted bases include N,N-diisopropylethylamine, triethylamine, 2,2,6,6-tetramethylpiperidine, 1,2,2,6,6-pentamethylpiperidine, N,N-dimethylaniline, N,N-dimethyltoluidine, 2,6-lutidine, sodium tetraphenylborate, potassium tetraphenylborate, triphenylborane, tetraphenylsilane, Ar ₄ BNa, Ar ₄ BK, Ar ₃ B, and Ar ₄ Si (wherein Ar is an aryl such as phenyl).

Further, as Lewis acids, AlCl ₃ , AlBr ₃ , AlF ₃ , BF ₃ .OEt ₂ , BCl ₃ , BBr ₃ , GaCl ₃ , GaBr ₃ , InCl ₃ , InBr ₃ , In(OTf) ₃ , SnCl ₄ , SnBr ₄ , AgOTf, ScCl ₃ , Sc(OTf) ₃ , ZnCl ₂ , ZnBr ₂ , Zn(OTf) ₂ , MgCl ₂ , MgBr ₂ , Mg(OTf) ₂ , LiOTf, NaOTf, KOTf, Me ₃ SiOTf, Cu(OTf) ₂ , CuCl ₂ , YCl ₃ , Y(OTf) ₃ , TiCl ₄ , _TiBr4 , _ZrCl4 , _ZrBr4 , _FeCl3 , _FeBr3 , _CoCl3 , _CoBr3 , etc.

In each of the above schemes, a Brönsted base or Lewis acid may be used to promote the tandem hetero Friedel-Crafts reaction. However, when using boron halides such as boron trifluoride, boron trichloride, boron tribromide, and boron triiodide, acids such as hydrogen fluoride, hydrogen chloride, hydrogen bromide, and hydrogen iodide are generated as the aromatic electrophilic substitution reaction proceeds, so the use of a Brönsted base to capture the acid is effective. On the other hand, when using boron amino halides and boron alkoxylates, amines and alcohols are generated as the aromatic electrophilic substitution reaction proceeds, so in many cases it is not necessary to use a Brönsted base, but since the amino and alkoxy groups have low elimination ability, the use of a Lewis acid to promote their elimination is effective.

3. Organic Devices The polycyclic aromatic compound according to the present invention can be used as a material for organic devices, such as organic electroluminescent devices, organic field effect transistors, and organic thin-film solar cells.

3-1. Organic Electroluminescence Device The organic EL device according to this embodiment will now be described in detail with reference to the drawings. Fig. 1 is a schematic cross-sectional view showing the organic EL device according to this embodiment.

<Structure of Organic Electroluminescent Device>
The organic EL element 100 shown in FIG. 1 has a substrate 101, an anode 102 provided on the substrate 101, a hole injection layer 103 provided on the anode 102, a hole transport layer 104 provided on the hole injection layer 103, a light emitting layer 105 provided on the hole transport layer 104, an electron transport layer 106 provided on the light emitting layer 105, an electron injection layer 107 provided on the electron transport layer 106, and a cathode 108 provided on the electron injection layer 107.

The organic EL element 100 may be fabricated in the reverse order, for example, with a substrate 101, a cathode 108 provided on the substrate 101, an electron injection layer 107 provided on the cathode 108, an electron transport layer 106 provided on the electron injection layer 107, a light-emitting layer 105 provided on the electron transport layer 106, a hole transport layer 104 provided on the light-emitting layer 105, a hole injection layer 103 provided on the hole transport layer 104, and an anode 102 provided on the hole injection layer 103.

Not all of the above layers are essential, and the minimum structural unit is the anode 102, the light-emitting layer 105, and the cathode 108, with the hole injection layer 103, the hole transport layer 104, the electron transport layer 106, and the electron injection layer 107 being layers that may be provided optionally. Each of the above layers may be a single layer or multiple layers.

In addition to the above-mentioned "substrate/anode/hole injection layer/hole transport layer/light-emitting layer/electron transport layer/electron injection layer/cathode" configuration, the layers constituting the organic EL element may be "substrate/anode/hole transport layer/light-emitting layer/electron transport layer/electron injection layer/cathode", "substrate/anode/hole injection layer/light-emitting layer/electron transport layer/electron injection layer/cathode", "substrate/anode/hole injection layer/light-emitting layer/electron transport layer/electron injection layer/cathode", "substrate/anode/hole injection layer/hole transport layer/light-emitting ... transport", The configuration may be "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 transport layer/light-emitting layer/electron transport layer/cathode", "substrate/anode/hole injection layer/light-emitting layer/electron injection layer/cathode", "substrate/anode/hole injection layer/light-emitting layer/electron transport layer/cathode", "substrate/anode/light-emitting layer/electron transport layer/cathode", "substrate/anode/light-emitting layer/electron transport layer/cathode", or "substrate/anode/light-emitting layer/electron injection layer/cathode".

<Substrate in Organic Electroluminescent Device>
The 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 into a plate, film, or 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. Among them, a glass plate and a plate made of a transparent synthetic resin such as polyester, polymethacrylate, polycarbonate, or polysulfone are preferable. For a glass substrate, soda-lime glass or alkali-free glass is used, and the thickness is sufficient to maintain mechanical strength, so that it may be, for example, 0.2 mm or more. The upper limit of the thickness is, for example, 2 mm or less, preferably 1 mm or less. As for the material of the glass, it is better to have fewer ions eluted from the glass, so alkali-free glass is preferable, but soda-lime glass with a barrier coat such as SiO ₂ is also commercially available, and this can be used. In addition, in order to improve the gas barrier properties, the substrate 101 may be provided with a gas barrier film such as a dense silicon oxide film on at least one side, and it is preferable to provide a gas barrier film, especially when a synthetic resin plate, film or sheet with poor gas barrier properties is used as the substrate 101.

<Anode in Organic Electroluminescent Device>
The anode 102 plays a role in injecting holes into the light-emitting layer 105. When at least one layer 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 via these layers.

Materials for forming the anode 102 include inorganic 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 (IZO), etc.), metal halides (copper iodide, etc.), copper sulfide, carbon black, ITO glass, and Nesa glass. Examples of organic compounds include polythiophenes such as poly(3-methylthiophene), polypyrrole, polyaniline, and other conductive polymers. In addition, materials that are used as anodes in organic EL elements can be appropriately selected and used.

The resistance of the transparent electrode is not limited as long as it can supply sufficient current to light the light-emitting element, but a low resistance is desirable from the viewpoint of the power consumption of the light-emitting element. For example, an ITO substrate of 300 Ω/□ or less will function as an element electrode, but since it is now possible to supply substrates of around 10 Ω/□, it is particularly desirable to use a low resistance product of, for example, 100 to 5 Ω/□, preferably 50 to 5 Ω/□. The thickness of the ITO can be selected arbitrarily according to the resistance value, but it is usually used in the range of 50 to 300 nm.

<Hole injection layer and hole transport layer in organic electroluminescence device>
The hole injection layer 103 plays a role of efficiently injecting holes moving from the anode 102 into the light emitting layer 105 or the hole transport layer 104. The hole transport layer 104 plays a role of efficiently transporting holes injected from the anode 102 or holes injected from the anode 102 through the hole injection layer 103 to the light emitting layer 105. The hole injection layer 103 and the hole transport layer 104 are each formed by laminating and mixing one or more types of hole injection/transport materials, or by a mixture of a hole injection/transport material and a polymer binder. Alternatively, a layer may be formed by adding an inorganic salt such as iron (III) chloride to the hole injection/transport material.

The hole injection/transport material must be able to efficiently inject and transport holes from the positive electrode between electrodes to which an electric field is applied, and it is desirable for the hole injection efficiency to be high and for the injected holes to be efficiently transported. For this purpose, it is preferable for the material to have a small ionization potential, a large hole mobility, and excellent stability, and to be unlikely to generate impurities that act as traps during manufacture and use.

As the material for forming the hole injection layer 103 and the hole transport layer 104, any compound can be selected from compounds conventionally used as charge transport materials for holes in photoconductive materials, p-type semiconductors, and known compounds used in hole injection layers and hole transport layers of organic EL elements. Specific examples thereof include carbazole derivatives (N-phenylcarbazole, polyvinylcarbazole, etc.), biscarbazole derivatives such as bis(N-arylcarbazole) or bis(N-alkylcarbazole), triarylamine derivatives (polymers having an aromatic tertiary amino in the main chain or side chain, 1,1-bis(4-di-p-tolylaminophenyl)cyclohexane, N,N'-diphenyl-N,N'-di(3-methylphenyl)-4,4'-diaminobiphenyl, N,N'-diphenyl-N,N'-dinaphthyl-4,4'-diaminobiphenyl, N,N'-diphenyl-N,N'-di(3-methylphenyl)-4,4'-diphenyl-1,1'-diamine, N,N'-dinaphthyl-N,N'-diphenyl-4,4'-diphenyl-1,1'-diamine, N ⁴ ,N ^{4 '} -diphenyl-N ⁴ ,N ^{4 '} -Bis(9-phenyl-9H-carbazol-3-yl)-[1,1'-biphenyl]-4,4'-diamine, N ⁴ , N ⁴ , N ^{4 '} , N ^{4 '} -tetra[1,1'-biphenyl]-4-yl)-[1,1'-biphenyl]-4,4'-diamine, triphenylamine derivatives such as 4,4',4"-tris(3-methylphenyl(phenyl)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 (for example, 1,4,5,8,9,12-hexaazatriphenylene-2,3,6,7,10,11-hexacarbonitrile, etc.), heterocyclic compounds such as porphyrin derivatives, polysilanes, etc. As for polymers, polycarbonates and styrene derivatives having the above-mentioned monomers in the side chains, polyvinylcarbazole, polysilane, etc. are preferable, but there is no particular limitation as long as they are compounds that can form a thin film required for producing a light-emitting element, can inject holes from the anode, and can transport holes.

It is also known that the electrical conductivity of organic semiconductors is strongly influenced by their doping. Such organic semiconductor matrix substances consist of compounds with good electron donating or accepting properties. For doping with electron donating substances, strong electron acceptors such as tetracyanoquinone dimethane (TCNQ) or 2,3,5,6-tetrafluorotetracyano-1,4-benzoquinone dimethane (F4TCNQ) are known (see, for example, the literature "M. Pfeiffer, A. Beyer, T. Fritz, K. Leo, Appl. Phys. Lett., 73(22), 3202-3204 (1998)" and the literature "J. Blochwitz, M. Pheiffer, T. Fritz, K. Leo, Appl. Phys. Lett., 73(6), 729-731 (1998)"). These generate so-called holes by an electron transfer process in an electron-donating base material (hole-transporting material). The conductivity of the base material varies considerably depending on the number and mobility of the holes. Matrix materials with hole-transporting properties are known, for example, as benzidine derivatives (such as TPD) or starburst amine derivatives (such as TDATA), or as certain metal phthalocyanines (especially zinc phthalocyanine (ZnPc)) (JP 2005-167175 A).

<Light-emitting layer in organic electroluminescent device>
The light-emitting layer 105 is a layer that emits light by recombining holes injected from the anode 102 and electrons injected from the cathode 108 between electrodes to which an electric field is applied. The material for the light-emitting layer 105 may be a compound (light-emitting compound) that is excited and emits light by the recombination of holes and electrons, and is preferably a compound that can be formed into a stable thin film shape and exhibits strong light-emitting (fluorescence) efficiency in a solid state.

The light-emitting layer may be a single layer or multiple layers, each of which is formed from light-emitting layer materials (host material, dopant material). The host material and the dopant material may each be one type, or a combination of multiple types. The dopant material may be contained entirely in the host material, or may be contained partially in the host material. As a doping method, the dopant material can be formed by co-evaporation with the host material, but it may also be mixed with the host material in advance and then vapor-deposited simultaneously.

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

The amount of dopant material used varies depending on the type of dopant material, and may be determined according to the characteristics of the dopant material. The amount of dopant used is preferably 0.001 to 50% by weight of the total light-emitting layer material, more preferably 0.05 to 20% by weight, and even more preferably 0.1 to 10% by weight. The above ranges are preferable in that, for example, concentration quenching can be prevented. In addition, from the viewpoint of durability, it is also preferable that some or all of the hydrogen atoms of the dopant material are deuterated.

Examples of host materials include condensed ring derivatives such as anthracene, pyrene, dibenzochrysene, or fluorene, which have long been known as light emitters; bisstyryl derivatives such as bisstyryl anthracene derivatives and distyrylbenzene derivatives; tetraphenylbutadiene derivatives; and cyclopentadiene derivatives. In particular, anthracene-based compounds, fluorene-based compounds, or dibenzochrysene-based compounds are preferred. From the viewpoint of durability, it is also preferred that some or all of the hydrogen atoms in the host material are deuterated. Furthermore, it is also preferred to form an emission layer by combining a host compound in which some or all of the hydrogen atoms are deuterated with a dopant compound in which some or all of the hydrogen atoms are deuterated.

<Anthracene-based compounds>
The anthracene compound serving as the host is, for example, a compound represented by the following general formula (3).

In formula (3),
X and Ar ⁴ are each independently hydrogen, optionally substituted aryl, optionally substituted heteroaryl, optionally substituted diarylamino, optionally substituted diheteroarylamino, optionally substituted arylheteroarylamino, optionally substituted alkyl, optionally substituted cycloalkyl, optionally substituted alkenyl, optionally substituted alkoxy, optionally substituted aryloxy, optionally substituted arylthio or optionally substituted silyl, and all of X and Ar ⁴ are not hydrogen at the same time;
At least one hydrogen atom in the compound represented by formula (3) may be substituted with halogen, cyano, deuterium or an optionally substituted heteroaryl.

A polymer (preferably a dimer) may be formed using the structure represented by formula (3) as a unit structure. In this case, for example, the unit structures represented by formula (3) may be bonded to each other via X, where X may be a single bond, an arylene (phenylene, biphenylene, naphthylene, etc.), or a heteroarylene (a pyridine ring, a dibenzofuran ring, a dibenzothiophene ring, a carbazole ring, a benzocarbazole ring, a phenyl-substituted carbazole ring, etc., having a divalent bond).

Details of the above aryl, heteroaryl, diarylamino, diheteroarylamino, arylheteroarylamino, alkyl, cycloalkyl, alkenyl, alkoxy, aryloxy, arylthio, or silyl are described in the preferred embodiments section below. In addition, examples of substituents for these include aryl, heteroaryl, diarylamino, diheteroarylamino, arylheteroarylamino, alkyl, cycloalkyl, alkenyl, alkoxy, aryloxy, arylthio, or silyl, and details of these are also described in the preferred embodiments section below.

Preferred embodiments of the above anthracene-based compounds are described below. The symbols in the structures below are defined as above.

In general formula (3), X is each independently a group represented by the above formula (3-X1), formula (3-X2) or formula (3-X3), and the group represented by formula (3-X1), formula (3-X2) or formula (3-X3) is bonded to the anthracene ring of formula (3) at *. Preferably, two Xs are not simultaneously a group represented by formula (3-X3). More preferably, two Xs are not simultaneously a group represented by formula (3-X2).

A polymer (preferably a dimer) may be formed using the structure represented by formula (3) as a unit structure. In this case, for example, the unit structures represented by formula (3) may be bonded to each other via X, where X may be a single bond, an arylene (phenylene, biphenylene, naphthylene, etc.), or a heteroarylene (a pyridine ring, a dibenzofuran ring, a dibenzothiophene ring, a carbazole ring, a benzocarbazole ring, a phenyl-substituted carbazole ring, etc., having a divalent bond).

The naphthylene moieties in formula (3-X1) and formula (3-X2) may be condensed with one benzene ring. The condensed structures are as follows:

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

Ar ³ is phenyl, biphenylyl, terphenylyl, quaterphenylyl, naphthyl, phenanthryl, fluorenyl, benzofluorenyl, chrysenyl, triphenylenyl, pyrenylyl, or a group represented by the above formula (A) (including a carbazolyl group, a benzocarbazolyl group, and a phenyl-substituted carbazolyl group). When Ar ³ is a group represented by formula (A), the group represented by formula (A) is bonded to the single bond represented by a straight line in formula (3-X3) at the *. That is, the anthracene ring of formula (3) and the group represented by formula (A) are directly bonded.

In addition, Ar ³ may have a substituent, and at least one hydrogen atom in Ar ³ may be further substituted with an alkyl having 1 to 4 carbon atoms, a cycloalkyl having 5 to 10 carbon atoms, phenyl, biphenylyl, terphenylyl, naphthyl, phenanthryl, fluorenyl, chrysenyl, triphenylenyl, pyrenylyl, or a group represented by the above formula (A) (including a carbazolyl group and a phenyl-substituted carbazolyl group). When the substituent in Ar ³ is a group represented by formula (A), the group represented by formula (A) bonds to Ar ³ in formula (3-X3) at the *.

Each ^Ar4 is independently hydrogen, phenyl, biphenylyl, terphenylyl, naphthyl, or silyl substituted with alkyl having 1 to 4 carbon atoms (eg, methyl, ethyl, t-butyl) and/or cycloalkyl having 5 to 10 carbon atoms.

Examples of alkyl groups with 1 to 4 carbon atoms that substitute for silyl include methyl, ethyl, propyl, i-propyl, butyl, sec-butyl, t-butyl, and cyclobutyl, and each of the three hydrogen atoms in the silyl is independently replaced by one of these alkyl groups.

Specific examples of "silyl substituted with alkyl having 1 to 4 carbon atoms" include trimethylsilyl, triethylsilyl, tripropylsilyl, tri-i-propylsilyl, tributylsilyl, trisec-butylsilyl, tri-t-butylsilyl, ethyldimethylsilyl, propyldimethylsilyl, i-propyldimethylsilyl, butyldimethylsilyl, sec-butyldimethylsilyl, t-butyldimethylsilyl, methyldiethylsilyl, propyldiethylsilyl, i-propyldiethylsilyl, butyldiethylsilyl, sec-butyldiethylsilyl, t-butyldiethylsilyl, methyldipropylsilyl, ethyldipropylsilyl, butyldipropylsilyl, sec-butyldipropylsilyl, t-butyldipropylsilyl, methyldi-i-propylsilyl, ethyldi-i-propylsilyl, butyldi-i-propylsilyl, sec-butyldi-i-propylsilyl, and t-butyldi-i-propylsilyl.

Examples of cycloalkyls having 5 to 10 carbon atoms that substitute for silyl include cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl, norbornenyl, bicyclo[1.1.1]pentyl, bicyclo[2.0.1]pentyl, bicyclo[1.2.1]hexyl, bicyclo[3.0.1]hexyl, bicyclo[2.1.2]heptyl, bicyclo[2.2.2]octyl, adamantyl, decahydronaphthalenyl, and decahydroazulenyl, and each of the three hydrogens in the silyl is independently replaced by one of these cycloalkyls.

Specific examples of "silyl substituted with cycloalkyl having 5 to 10 carbon atoms" include tricyclopentylsilyl and tricyclohexylsilyl.

Substituted silyls include dialkylcycloalkylsilyls, which are substituted with two alkyls and one cycloalkyl, and alkyldicycloalkylsilyls, which are substituted with one alkyl and two cycloalkyls. Specific examples of the alkyl and cycloalkyl substituents are the groups mentioned above.

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

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

In the above formula (A), Y is -O-, -S- or >N-R ²⁹ , R ²¹ to R ²⁸ are each independently hydrogen, optionally substituted alkyl, optionally substituted cycloalkyl, optionally substituted aryl, optionally substituted heteroaryl, optionally substituted alkoxy, optionally substituted aryloxy, optionally substituted arylthio, trialkylsilyl, tricycloalkylsilyl, dialkylcycloalkylsilyl, alkyldicycloalkylsilyl, optionally substituted amino, halogen, hydroxy or cyano, adjacent groups among R ²¹ to R ²⁸ may be bonded to each other to form a hydrocarbon ring, an aryl ring or a heteroaryl ring, and R ²⁹ is hydrogen or optionally substituted aryl.

The "alkyl" in the "optionally substituted alkyl" in R ²¹ to R ²⁸ may be either linear or branched, and examples thereof include linear alkyl having 1 to 24 carbon atoms or branched alkyl having 3 to 24 carbon atoms. An alkyl having 1 to 18 carbon atoms (branched alkyl having 3 to 18 carbon atoms) is preferred, an alkyl having 1 to 12 carbon atoms (branched alkyl having 3 to 12 carbon atoms) is more preferred, an alkyl having 1 to 6 carbon atoms (branched alkyl having 3 to 6 carbon atoms) is even more preferred, and an alkyl having 1 to 4 carbon atoms (branched alkyl having 3 to 4 carbon atoms) is particularly preferred.

Specific examples of "alkyl" include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, s-butyl, t-butyl, n-pentyl, isopentyl, neopentyl, t-pentyl (t-amyl), n-hexyl, 1-methylpentyl, 3,3-dimethylbutyl, 2-ethylbutyl, n-heptyl, 1-methylhexyl, n-octyl, t-octyl (1,1,3,3-tetramethylbutyl), 1-methyl Examples include n-hexylheptyl, 2-ethylhexyl, 2-propylpentyl, n-nonyl, 2,2-dimethylheptyl, 2,6-dimethyl-4-heptyl, 3,5,5-trimethylhexyl, n-decyl, n-undecyl, 1-methyldecyl, n-dodecyl, n-tridecyl, 1-hexylheptyl, n-tetradecyl, n-pentadecyl, n-hexadecyl, n-heptadecyl, n-octadecyl, and n-eicosyl.

Examples of the "cycloalkyl" in the "optionally substituted cycloalkyl" in R ²¹ to R ²⁸ include cycloalkyl having 3 to 24 carbon atoms, cycloalkyl having 3 to 20 carbon atoms, cycloalkyl having 3 to 16 carbon atoms, cycloalkyl having 3 to 14 carbon atoms, cycloalkyl having 5 to 10 carbon atoms, cycloalkyl having 5 to 8 carbon atoms, cycloalkyl having 5 to 6 carbon atoms, and cycloalkyl having 5 carbon atoms.

Specific examples of "cycloalkyl" include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl, and alkyl (especially methyl) substituted derivatives of these having 1 to 4 carbon atoms, as well as norbornenyl, bicyclo[1.0.1]butyl, bicyclo[1.1.1]pentyl, bicyclo[2.0.1]pentyl, bicyclo[1.2.1]hexyl, bicyclo[3.0.1]hexyl, bicyclo[2.1.2]heptyl, bicyclo[2.2.2]octyl, adamantyl, diamantyl, decahydronaphthalenyl, and decahydroazulenyl.

The "aryl" in the "optionally substituted aryl" in R ^{to R} is, for example, an aryl having 6 to 30 carbon atoms, preferably an aryl having 6 to 16 carbon atoms, more preferably an aryl having 6 to 12 carbon atoms, and particularly preferably an aryl having 6 to 10 carbon atoms.

Specific examples of "aryl" include monocyclic phenyl, bicyclic ...

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

Specific examples of "heteroaryl" include pyrrolyl, oxazolyl, isoxazolyl, thiazolyl, isothiazolyl, imidazolyl, oxadiazolyl, thiadiazolyl, triazolyl, tetrazolyl, pyrazolyl, pyridyl, pyrimidinyl, pyridazinyl, pyrazinyl, triazinyl, indolyl, isoindolyl, 1H-indazolyl, benzimidazolyl, benzoxazolyl, benzothiazolyl, 1H-benzotriazolyl, quinolyl, isoquinolyl, cyclohex ... These include aryl, quinazolyl, quinoxalinyl, phthalazinyl, naphthyridinyl, purinyl, pteridinyl, carbazolyl, acridinyl, phenoxathiinyl, phenoxazinyl, phenothiazinyl, phenazinyl, indolizinyl, furyl, benzofuranyl, isobenzofuranyl, dibenzofuranyl, thienyl, benzo[b]thienyl, dibenzothienyl, furazanyl, oxadiazolyl, thianthrenyl, naphthobenzofuranyl, and naphthobenzothienyl.

Examples of the "alkoxy" in the "optionally substituted alkoxy" in R ²¹ to R ²⁸ include linear alkoxy having 1 to 24 carbon atoms or branched alkoxy having 3 to 24 carbon atoms. An alkoxy having 1 to 18 carbon atoms (branched alkoxy having 3 to 18 carbon atoms) is preferred, an alkoxy having 1 to 12 carbon atoms (branched alkoxy having 3 to 12 carbon atoms) is more preferred, an alkoxy having 1 to 6 carbon atoms (branched alkoxy having 3 to 6 carbon atoms) is even more preferred, and an alkoxy having 1 to 4 carbon atoms (branched alkoxy having 3 to 4 carbon atoms) is particularly preferred.

Specific examples of "alkoxy" include methoxy, ethoxy, propoxy, isopropoxy, butoxy, isobutoxy, s-butoxy, t-butoxy, pentyloxy, hexyloxy, heptyloxy, and octyloxy.

The "aryloxy" in the "optionally substituted aryloxy" in R ²¹ to R ²⁸ is a group in which the hydrogen of the -OH group is substituted with an aryl, and the aryl can be any of the groups explained above as the "aryl" in R ²¹ to R ²⁸ .

The "arylthio" in the "optionally substituted arylthio" in R ²¹ to R ²⁸ is a group in which the hydrogen of the -SH group is replaced by an aryl, and the aryl can be any of the groups explained as the "aryl" in R ²¹ to R ²⁸ above.

The "trialkylsilyl" in R ²¹ to R ²⁸ includes a group in which three hydrogen atoms in a silyl group are each independently substituted with an alkyl, and this alkyl can be cited from the groups explained above as the "alkyl" in R ²¹ to R ^28. The alkyl to be substituted is preferably an alkyl having 1 to 4 carbon atoms, and specific examples thereof include methyl, ethyl, propyl, i-propyl, butyl, sec-butyl, t-butyl, cyclobutyl, and the like.

Specific examples of "trialkylsilyl" include trimethylsilyl, triethylsilyl, tripropylsilyl, tri-i-propylsilyl, tributylsilyl, trisec-butylsilyl, tri-t-butylsilyl, ethyldimethylsilyl, propyldimethylsilyl, i-propyldimethylsilyl, butyldimethylsilyl, sec-butyldimethylsilyl, t-butyldimethylsilyl, methyldiethylsilyl, propyldiethylsilyl, i-propyldiethylsilyl, butyldiethylsilyl, sec-butyldiethylsilyl, t-butyldiethylsilyl, methyldipropylsilyl, ethyldipropylsilyl, butyldipropylsilyl, sec-butyldipropylsilyl, t-butyldipropylsilyl, methyldi-i-propylsilyl, ethyldi-i-propylsilyl, butyldi-i-propylsilyl, sec-butyldi-i-propylsilyl, and t-butyldi-i-propylsilyl.

The "tricycloalkylsilyl" in R ²¹ to R ²⁸ includes a group in which three hydrogen atoms in a silyl group are each independently replaced with a cycloalkyl, and this cycloalkyl can be cited from the groups explained as the "cycloalkyl" in R ²¹ to R ²⁸ above. Preferred cycloalkyl for substitution is a cycloalkyl having 5 to 10 carbon atoms, and specific examples thereof include cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl, bicyclo[1.1.1]pentyl, bicyclo[2.0.1]pentyl, bicyclo[1.2.1]hexyl, bicyclo[3.0.1]hexyl, bicyclo[2.1.2]heptyl, bicyclo[2.2.2]octyl, adamantyl, decahydronaphthalenyl, and decahydroazulenyl.

Specific examples of "tricycloalkylsilyl" include tricyclopentylsilyl and tricyclohexylsilyl.

Specific examples of dialkylcycloalkylsilyl substituted with two alkyls and one cycloalkyl, and alkyldicycloalkylsilyl substituted with one alkyl and two cycloalkyls include silyl substituted with a group selected from the specific alkyls and cycloalkyls mentioned above.

The "substituted amino" in the "optionally substituted amino" in R ²¹ to R ²⁸ includes, for example, an amino group in which two hydrogen atoms are substituted with aryl or heteroaryl. An amino group in which two hydrogen atoms are substituted with aryl atoms is a diaryl-substituted amino, an amino group in which two hydrogen atoms are substituted with heteroaryl atoms is a diheteroaryl-substituted amino, and an amino group in which two hydrogen atoms are substituted with an aryl and a heteroaryl atom is an arylheteroaryl-substituted amino. The aryl and heteroaryl groups can be cited from the groups explained as "aryl" and "heteroaryl" in R ²¹ to R ²⁸ above.

Specific examples of "substituted amino" include diphenylamino, dinaphthylamino, phenylnaphthylamino, dipyridylamino, phenylpyridylamino, and naphthylpyridylamino.

The "halogen" in R ²¹ to R ²⁸ includes fluorine, chlorine, bromine and iodine.

Some of the groups described as R ²¹ to R ²⁸ may be substituted as described above, and in this case, the substituents include alkyl, cycloalkyl, aryl, or heteroaryl. The alkyl, cycloalkyl, aryl, or heteroaryl may refer to the groups described as "alkyl", "cycloalkyl", "aryl", or "heteroaryl" in R ²¹ to R ²⁸ above.

R ²⁹ in ">N-R ²⁹ " as Y is hydrogen or an optionally substituted aryl, and examples of this aryl include the groups described above as the "aryl" in R ²¹ to R ²⁸ , and examples of the substituents thereof include the groups described above as the substituents for R ²¹ to R ²⁸ .

Adjacent groups among R ²¹ to R ²⁸ may be bonded to each other to form a hydrocarbon ring, an aryl ring, or a heteroaryl ring. The group represented by the following formula (A-1) does not form a ring, and examples of the group represented by any of the following formulas (A-2) to (A-14) include groups represented by the following formulas (A-1) to (A-14). At least one hydrogen atom in the group represented by any of formulas (A-1) to (A-14) may be substituted with alkyl, cycloalkyl, aryl, heteroaryl, alkoxy, aryloxy, arylthio, trialkylsilyl, tricycloalkylsilyl, dialkylcycloalkylsilyl, alkyldicycloalkylsilyl, diaryl-substituted amino, diheteroaryl-substituted amino, arylheteroaryl-substituted amino, halogen, hydroxy, or cyano. Y and * in the formulas are defined as above.

Examples of rings formed by bonding adjacent groups to each other include hydrocarbon rings such as cyclohexane rings, and examples of aryl rings and heteroaryl rings include the ring structures explained in relation to "aryl" and "heteroaryl" in ^R21 to ^R28 above, and these rings are formed so as to be condensed with one or two benzene rings in the above formula (A-1).

Examples of the group represented by formula (A) include groups represented by any of the above formulas (A-1) to (A-14), with groups represented by any of the above formulas (A-1) to (A-5) and (A-12) to (A-14) being preferred, groups represented by any of the above formulas (A-1) to (A-4) being more preferred, groups represented by any of the above formulas (A-1), (A-3) and (A-4) being even more preferred, and groups represented by the above formula (A-1) being particularly preferred.

As described above, the group represented by formula (A) is bonded to the naphthalene ring in formula (3-X1) or formula (3-X2), the single bond in formula (3-X3), or Ar ³ in formula (3-X3) at * in formula (A), and is substituted for at least one hydrogen in the compound represented by formula (3). Among these bonding forms, a bonding form to at least one of the naphthalene ring in formula (3-X1) or formula (3-X2), the single bond in formula (3-X3), and Ar ³ in formula (3-X3) is preferred.

In addition, in the structure of the group represented by formula (A), the naphthalene ring in formula (3-X1) or formula (3-X2), the single bond in formula (3-X3), and the position at which Ar ³ in formula (3-X3) is bonded, and in the structure of the group represented by formula (A), the position at which at least one hydrogen atom in the compound represented by formula (3) is substituted, may be any position in the structure of formula (A), and may be bonded, for example, to any of the two benzene rings in the structure of formula (A), to any ring formed by bonding adjacent groups among R ²¹ to R ²⁸ in the structure of formula (A), or to any position in R ²⁹ in “>N-R ²⁹ ” as Y in the structure of formula (A).

Examples of the group represented by formula (A) include the following groups: In the formula, Y and * are defined as above.

In addition, all or some of the hydrogen atoms in the chemical structure of the anthracene compound represented by general formula (3) may be deuterium atoms.

Specific examples of anthracene compounds include compounds represented by any of the following formulas (3-1) to (3-142). In the structural formulas below, "Me" represents a methyl group, "D" represents deuterium, and "tBu" represents a t-butyl group.

The anthracene compound represented by formula (3) can be produced by applying Suzuki coupling, Negishi coupling, or other known coupling reactions using a compound having a reactive group at a desired position of the anthracene skeleton and a compound having a reactive group in a partial structure such as X, ^Ar4 , and the structure of formula (A) as starting materials. Examples of reactive groups in these reactive compounds include halogens and boronic acids. As a specific production method, for example, the synthesis method in paragraphs [0089] to [0175] of WO 2014/141725 A can be referred to.

<Fluorene-based compounds>
The compound represented by formula (4) basically functions as a host.

In the above formula (4),
R ¹ to R ¹⁰ are each independently hydrogen, aryl, heteroaryl (the heteroaryl may be bonded to the fluorene skeleton in the above formula (4) via a linking group), diarylamino, diheteroarylamino, arylheteroarylamino, alkyl, cycloalkyl, alkenyl, alkoxy or aryloxy, in which at least one hydrogen may be substituted with an aryl, heteroaryl, alkyl or cycloalkyl;
In addition, ^R1 and ^R2 , ^R2 and ^R3 , ^R3 and ^R4 , ^R5 and ^R6 , ^R6 and ^R7 , ^R7 and ^R8, or ^R9 and ^R10 may each independently bond to form a fused ring or a spiro ring, in which at least one hydrogen atom in the formed ring may be substituted with an aryl, a heteroaryl (the heteroaryl may be bonded to the formed ring via a linking group), a diarylamino, a diheteroarylamino, an arylheteroarylamino, an alkyl, a cycloalkyl, an alkenyl, an alkoxy, or an aryloxy, in which at least one hydrogen atom may be substituted with an aryl, a heteroaryl, an alkyl, or a cycloalkyl, and
At least one hydrogen in the compound represented by formula (4) may be substituted with halogen, cyano or deuterium.

For details of each group in the definition of the above formula (4), the explanation for the polycyclic aromatic compound of the above formula (1) or formula (2) can be cited.

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

式（４－Ａｒ１）から式（４－Ａｒ５）中、Ｙ^１は、それぞれ独立して、Ｏ、ＳまたはＮ－Ｒであり、Ｒはフェニル、ビフェニリル、ナフチル、アントラセニルまたは水素であり、
上記式（４－Ａｒ１）から式（４－Ａｒ５）の構造における少なくとも１つの水素はフェニル、ビフェニリル、ナフチル、アントラセニル、フェナントレニル、メチル、エチル、プロピル、または、ブチルで置換されていてもよい。 Specific examples of heteroaryl include monovalent groups represented by removing any one hydrogen atom from a compound of the following formula (4-Ar1), formula (4-Ar2), formula (4-Ar3), formula (4-Ar4), or formula (4-Ar5).

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

These heteroaryls may be bonded to the fluorene skeleton in formula (4) via a linking group. That is, the fluorene skeleton in formula (4) and the heteroaryl may be bonded directly, or may be bonded to each other via a linking group. Examples of the linking group include phenylene, biphenylene, naphthylene, anthracenylene, methylene, ethylene, -OCH ₂ CH ₂ -, -CH ₂ CH ₂ O-, and -OCH ₂ CH ₂ O-.

In addition, R ¹ and R ² , R ² and R ³ , R ³ and R ⁴ , R ⁵ and R ⁶ , R ⁶ and R ⁷ or R ⁷ and R ⁸ in formula (4) may be independently bonded to form a fused ring, and R ⁹ and R ¹⁰ may be bonded to form a spiro ring. The fused ring formed by R ¹ to R ⁸ is a ring fused to the benzene ring in formula (4), and is an aliphatic ring or an aromatic ring. It is preferably an aromatic ring, and examples of the structure including the benzene ring in formula (4) include a naphthalene ring and a phenanthrene ring. The spiro ring formed by R ⁹ and R ¹⁰ is a ring spiro-bonded to the 5-membered ring in formula (4), and is an aliphatic ring or an aromatic ring. It is preferably an aromatic ring, and examples of the structure including the benzene ring in formula (4) include a fluorene ring.

The compound represented by general formula (4) is preferably a compound represented by the following formula (4-1), formula (4-2) or formula (4-3), which is a compound in which a benzene ring formed by bonding R ¹ and R ² in general formula (4) is condensed, a compound in which a benzene ring formed by bonding R ³ and R ⁴ in general formula (4) is condensed, and a compound in which none of R ¹ to R ⁸ is bonded in general formula (4), respectively.

The definitions of R ¹ to R ¹⁰ in formulas (4-1), (4-2) and (4-3) are the same as the corresponding R ¹ to R ¹⁰ in formula (4), and the definitions of R ¹¹ to R ¹⁴ in formulas (4-1) and (4-2) are the same as the corresponding R ¹ to R ¹⁰ in formula (4).

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

The definitions of R ² to R ⁷ in formulae (4-1A), (4-2A) and (4-3A) are the same as the corresponding R ² to R ⁷ in formulae (4-1), (4-2) and (4-3), and the definitions of R ¹¹ to R ¹⁴ in formulae (4-1A) and (4-2A) are the same as R ¹¹ to R ¹⁴ in formulae (4-1) and (4-2).

In addition, all or some of the hydrogen atoms in the compound represented by formula (4) may be replaced with halogen, cyano, or deuterium.

Specific examples of the fluorene-based compound include compounds represented by any one of the following formulas (4-4) to (4-22): In the following structural formulas, "Me" represents a methyl group.

<Dibenzochrysene compounds>
The dibenzochrysene compound as the host is, for example, a compound represented by the following general formula (5).

In the above formula (5),
^R1 to ^R16 are each independently hydrogen, aryl, heteroaryl (the heteroaryl may be bonded to the dibenzochrysene skeleton in the above formula (5) via a linking group), diarylamino, diheteroarylamino, arylheteroarylamino, alkyl, cycloalkyl, alkenyl, alkoxy or aryloxy, in which at least one hydrogen may be substituted with an aryl, heteroaryl, alkyl or cycloalkyl;
In addition, adjacent groups among R ¹ to R ¹⁶ may be bonded to each other to form a fused ring, and at least one hydrogen atom in the formed ring may be substituted with an aryl, a heteroaryl (the heteroaryl may be bonded to the formed ring via a linking group), a diarylamino, a diheteroarylamino, an arylheteroarylamino, an alkyl, a cycloalkyl, an alkenyl, an alkoxy, or an aryloxy, and at least one hydrogen atom in these may be substituted with an aryl, a heteroaryl, an alkyl, or a cycloalkyl, and
At least one hydrogen in the compound represented by formula (5) may be substituted with halogen, cyano or deuterium.

For details of each group in the definition of the above formula (5), the explanation for the polycyclic aromatic compound of the above formula (1) or formula (2) can be cited.

The alkenyl in the definition of the above formula (5) is, for example, an alkenyl having 2 to 30 carbon atoms, preferably an alkenyl having 2 to 20 carbon atoms, more preferably an alkenyl having 2 to 10 carbon atoms, even more preferably an alkenyl having 2 to 6 carbon atoms, and particularly preferably an alkenyl having 2 to 4 carbon atoms. Preferred alkenyls are vinyl, 1-propenyl, 2-propenyl, 1-butenyl, 2-butenyl, 3-butenyl, 1-pentenyl, 2-pentenyl, 3-pentenyl, 4-pentenyl, 1-hexenyl, 2-hexenyl, 3-hexenyl, 4-hexenyl, or 5-hexenyl.

式（５－Ａｒ１）から式（５－Ａｒ５）中、Ｙ^１は、それぞれ独立して、Ｏ、ＳまたはＮ－Ｒであり、Ｒはフェニル、ビフェニリル、ナフチル、アントラセニルまたは水素であり、
上記式（５－Ａｒ１）から式（５－Ａｒ５）の構造における少なくとも１つの水素はフェニル、ビフェニリル、ナフチル、アントラセニル、フェナントレニル、メチル、エチル、プロピル、または、ブチルで置換されていてもよい。 Specific examples of heteroaryl include monovalent groups represented by removing any one hydrogen atom from a compound of the following formula (5-Ar1), formula (5-Ar2), formula (5-Ar3), formula (5-Ar4), or formula (5-Ar5).

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

These heteroaryls may be bonded to the dibenzochrysene skeleton in formula (5) via a linking group. That is, the dibenzochrysene skeleton and the heteroaryl in formula (5) may be bonded directly or via a linking group. Examples of the linking group include phenylene, biphenylene, naphthylene, anthracenylene, methylene, ethylene, -OCH ₂ CH ₂ -, -CH ₂ CH ₂ O-, and -OCH ₂ CH ₂ O-.

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

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

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

Specific examples of the dibenzochrysene compound include compounds represented by any of the following formulas (5-1) to (5-39): In the following structural formulas, "tBu" represents a t-butyl group.

<Polycyclic aromatic compound>
The polycyclic aromatic compound as the host is, for example, a polycyclic aromatic compound represented by the following general formula (6), a polycyclic aromatic compound represented by the following general formula (7), or a polycyclic aromatic compound represented by the following general formula ( The preferred forms of each compound are the polycyclic aromatic compounds represented by the following general formula (6') and the polycyclic aromatic compounds represented by the following general formula (7'): The polycyclic aromatic compound is a polycyclic aromatic compound represented by the following general formula (8'). The definitions of the symbols in the following structural formula are as follows: The definitions of the symbols in formula (8) and general formulas (6'), (7') and (8') are the same as those in the following formulas. For details of the above, the explanations of the general formula (1) and the formula (2) can be cited.

In the above formulas (6), (7) and (8),
ring A, ring B and ring C are each independently an aryl ring or a heteroaryl ring, and at least one hydrogen atom in these rings may be substituted;
X ¹ , X ² and X ³ are each independently >O, >N-R, >C(-R) ₂ , >S or >Se, R of the >N-R is an optionally substituted aryl, an optionally substituted heteroaryl, an optionally substituted alkyl or an optionally substituted cycloalkyl, R of the >C(-R) ₂ is a hydrogen, an optionally substituted aryl, an optionally substituted alkyl or an optionally substituted cycloalkyl, and at least one of the R of the >N-R and the R of the >C(-R) ₂ may be bonded to at least one of the rings A, B and C via a linking group;
R ⁴ and R ⁷ are each independently hydrogen, an aryl having 6 to 12 carbon atoms, a heteroaryl having 2 to 15 carbon atoms, a diarylamino (wherein the aryl has 6 to 12 carbon atoms), an alkyl having 1 to 6 carbon atoms, or a cycloalkyl having 3 to 14 carbon atoms;
In the compound represented by formula (6), formula (7) or formula (8), at least one of ring A, ring B, ring C, aryl and heteroaryl may be condensed with at least one cycloalkane, at least one hydrogen in the cycloalkane may be substituted, and at least one -CH ₂ - in the cycloalkane may be substituted with -O-, and
At least one hydrogen atom in the compound represented by formula (6), formula (7) or formula (8) may be substituted with cyano, halogen or deuterium.
For details of the structural form and substituents of the compounds in each formula, the explanations for the above general formulas (1) and (2) can be cited.

In the above formula (6'), formula (7') and formula (8'),
Any "-C(-R)=" (where R is R ¹ to R ¹¹ in each formula) in the ring a, ring b, and ring c may be replaced with "-N=", any "-C(-R)=C(-R)-" (where R is R ¹ to R ¹¹ in each formula) may be replaced with "-N(-R)-", "-O-", or "-S-", where R in the "-N(-R)-" is aryl, alkyl, or cycloalkyl, and in formula (8'), any "-C(-R)=" (where R is R ⁴ or R ⁷ in formula (8')) in the ring c may be replaced with "-N=",
R ¹ to R ¹¹ are each independently hydrogen, aryl, heteroaryl, diarylamino, diheteroarylamino, arylheteroarylamino, diarylboryl (two aryls may be bonded via a single bond or a linking group), alkyl, cycloalkyl, alkoxy, aryloxy, triarylsilyl, trialkylsilyl, tricycloalkylsilyl, dialkylcycloalkylsilyl, or alkyldicycloalkylsilyl, in which at least one hydrogen may be substituted with an aryl, heteroaryl, alkyl, or cycloalkyl;
In addition, adjacent groups among R ¹ to R ¹¹ may be bonded to each other to form an aryl ring or a heteroaryl ring together with the ring a, the ring b, or the ring c, and at least one hydrogen atom in the formed ring may be substituted with an aryl, a heteroaryl, a diarylamino, a diheteroarylamino, an arylheteroarylamino, a diarylboryl (two aryls may be bonded via a single bond or a linking group), an alkyl, a cycloalkyl, an alkoxy, an aryloxy, a triarylsilyl, a trialkylsilyl, a tricycloalkylsilyl, a dialkylcycloalkylsilyl, or an alkyldicycloalkylsilyl, and at least one hydrogen atom in these rings may be substituted with an aryl, a heteroaryl, an alkyl, or a cycloalkyl,
In the formula (8'), R ⁴ and R ⁷ are each independently hydrogen, an aryl having 6 to 12 carbon atoms, a heteroaryl having 2 to 15 carbon atoms, a diarylamino (wherein the aryl has 6 to 12 carbon atoms), an alkyl having 1 to 6 carbon atoms, or a cycloalkyl having 3 to 14 carbon atoms;
X ¹ , X ² and X ³ each independently represent >O, >N-R, >C(-R) ₂ , >S or >Se, R of the >N-R represents an aryl having 6 to 12 carbon atoms, a heteroaryl having 2 to 15 carbon atoms, an alkyl having 1 to 6 carbon atoms or a cycloalkyl having 3 to 14 carbon atoms, R of the >C(-R) ₂ represents hydrogen, an aryl having 6 to 12 carbon atoms, an alkyl having 1 to 6 carbon atoms or a cycloalkyl having 3 to 14 carbon atoms, at least one of R of the >N-R and R of the >C(-R) ₂ may be bonded to at least one of the ring a, ring b and ring c via a single bond, -O-, -S- or -C(-R) ₂ -, R of the -C(-R) ₂ - represents an alkyl having 1 to 6 carbon atoms or a cycloalkyl having 3 to 14 carbon atoms,
In the compound represented by formula (6'), formula (7') or formula (8'), at least one of the ring a, the ring b, the ring c, the formed ring, the aryl and the heteroaryl may be condensed with at least one cycloalkane having 3 to 24 carbon atoms, at least one hydrogen in the cycloalkane may be substituted with an aryl having 6 to 30 carbon atoms, a heteroaryl having 2 to 30 carbon atoms, an alkyl having 1 to 24 carbon atoms or a cycloalkyl having 3 to 24 carbon atoms, at least one -CH ₂ - in the cycloalkane may be substituted with -O-, and
At least one hydrogen atom in the compound represented by formula (6'), formula (7') or formula (8') may be substituted with cyano, halogen or deuterium.
For details of the structural form and substituents of the compounds in each formula, the explanations for the above general formulas (1) and (2) can be cited.

In the compound of formula (6) or formula (6'), a compound in which the ring B and the ring C (ring b and ring c) are linked by ^X3 equivalent to ^X1 and ^X2 is a compound of formula (7) or formula (7'), and a dimer formed so as to share the ring C (ring c) in the compound of formula (6) or formula (6') is a compound of formula (8) or formula (8'). Since the structures of the compounds are similar in this way, the compound of formula (6) or formula (6') will be described below as a representative, but the description also applies to the compound of formula (7) or formula (7') and the compound of formula (8) or formula (8').

The A ring, B ring and C ring in the general formula (6) are each independently an aryl ring or a heteroaryl ring, and at least one hydrogen atom in these rings may be substituted with a substituent. The substituent is preferably a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted diarylamino, a substituted or unsubstituted diheteroarylamino, a substituted or unsubstituted arylheteroarylamino (an amino group having an aryl and a heteroaryl), a substituted or unsubstituted diarylboryl (two aryls may be bonded via a single bond or a linking group), a substituted or unsubstituted alkyl, a substituted or unsubstituted cycloalkyl, a substituted or unsubstituted alkoxy, a substituted or unsubstituted aryloxy, or a substituted silyl. Examples of the substituent when these groups have a substituent include aryl, heteroaryl, alkyl or cycloalkyl. In addition, the aryl ring or heteroaryl ring preferably has a 5-membered or 6-membered ring that shares a bond with the central fused two-ring structure of the general formula (6) composed of the central elements "B (boron)", "X ¹ " and "X ² ".

Ring A (or ring B, ring C) in general formula (6) corresponds to ring a and its substituents R ¹ to R ³ (or ring b and its substituents R ⁸ to R ¹¹ , ring c and its substituents R ⁴ to R ⁷ ) in general formula (6'). That is, general formula (6') corresponds to a structure in which "rings A to C having 6-membered rings" are selected as rings A to C in general formula (6). In that sense, each ring in general formula (6') is represented by lowercase letters a to c.

In the general formula (6'), adjacent groups among the substituents R ¹ to R ¹¹ of the ring a, ring b, and ring c may be bonded to each other to form an aryl ring or a heteroaryl ring together with the ring a, ring b, or ring c, and at least one hydrogen atom in the formed ring may be substituted with an aryl, heteroaryl, diarylamino, diheteroarylamino, arylheteroarylamino, diarylboryl (two aryls may be bonded via a single bond or a linking group), alkyl, cycloalkyl, alkoxy, aryloxy, triarylsilyl, trialkylsilyl, tricycloalkylsilyl, dialkylcycloalkylsilyl, or alkyldicycloalkylsilyl, and at least one hydrogen atom in these may be substituted with an aryl, heteroaryl, alkyl, or cycloalkyl. Therefore, the ring structure constituting the polycyclic aromatic compound represented by the general formula (6') changes depending on the mutual bonding form of the substituents in the ring a, ring b, and ring c. This is as explained using the formulas (2-1) and (2-2) in the explanation of the general formula (1).

The explanation for the "aryl ring" and "heteroaryl ring" which are the A ring, B ring, and C ring of the general formula (6) can be found in the explanation for the general formula (1). In addition, the explanation for the first and second substituents which are substituted on the "aryl ring" and "heteroaryl ring" can be found in the explanation for the general formula (1) and formula (2).

X ¹ and X ² in the general formula (6) are each independently >O, >N-R, >C(-R) ₂ , >S or >Se, R in the >N-R is an optionally substituted aryl, an optionally substituted heteroaryl, an optionally substituted alkyl or an optionally substituted cycloalkyl, R in the >C(-R) ₂ is hydrogen, an optionally substituted aryl, an optionally substituted alkyl or an optionally substituted cycloalkyl, and at least one of R in the >N-R and R in the >C(-R) ₂ may be bonded to at least one of the rings A, B and C by a linking group, and the linking group is preferably -O-, -S- or -C(-R) ₂ -. Incidentally, R in the "-C(-R) ₂ -" is hydrogen, an alkyl or a cycloalkyl. This explanation is the same for X ¹ and X ² in the general formula (6').

Here, the provision in general formula (6) that "at least one of R of the >N-R and R of the >C(-R) ₂ is bonded to at least one of the rings A, B and C via a linking group" corresponds to the provision in general formula (6') that "at least one of R of the >N-R and R of the >C(-R) ₂ is bonded to at least one of the rings a, b and c via a single bond, -O-, -S-, or -C(-R) ₂ -".

This definition can be expressed by a compound having a ring structure in which ^X1 and ^X2 are incorporated into fused ring B' and fused ring C', as represented by the following formula (6'- ^3-1 ). That is, for example, it is a compound having ring B' (or ring C') formed by condensing another ring to ring b (or ring c) of the benzene ring in general formula (6') so as to incorporate ^X1 (or X2). The fused ring B' (or fused ring C') thus formed is, for example, a phenoxazine ring, a phenothiazine ring, or an acridine ring.

The above definition can also be expressed by a compound having a ring structure in which at least one of ^X1 and ^X2 is incorporated into a fused ring A', as represented by the following formula (6'-3-2) or formula (6'-3-3). That is, for example, it is a compound having a ring A' formed by condensing another ring to the benzene ^ring , which is the ring a in general formula (6'), so as to incorporate ^X1 (or ^X2 , or X1 and ^X2 ). The fused ring A' thus formed is, for example, a phenoxazine ring, a phenothiazine ring, or an acridine ring.

R of >N-R in ^X1 and ^X2 in general formula (6) is an aryl, heteroaryl, alkyl or cycloalkyl which may be substituted with the second substituent described above, and at least one hydrogen in the aryl, heteroaryl, alkyl or cycloalkyl may be substituted with, for example, an alkyl or cycloalkyl. The explanations of general formulas (1) and (2) can also be cited for this aryl, heteroaryl, alkyl or cycloalkyl. In particular, aryl having 6 to 10 carbon atoms (e.g., phenyl, naphthyl, etc.), heteroaryl having 2 to 15 carbon atoms (e.g., carbazolyl, etc.), alkyl having 1 to 4 carbon atoms (e.g., methyl, ethyl, etc.) or cycloalkyl having 5 to 10 carbon atoms (preferably cyclohexyl or adamantyl) are preferred. This explanation is also applicable to ^X1 and ^X2 in general formula (6').

R of >C(-R) ₂ in ^X1 and ^X2 in general formula (6) is hydrogen, an aryl, an alkyl or a cycloalkyl which may be substituted with the second substituent described above, and at least one hydrogen in the aryl may be substituted with, for example, an alkyl. The explanation of the aryl, alkyl or cycloalkyl can also be cited for the aryl, alkyl or cycloalkyl. In particular, an aryl having 6 to 10 carbon atoms (e.g., phenyl, naphthyl, etc.), an alkyl having 1 to 4 carbon atoms (e.g., methyl, ethyl, etc.) or a cycloalkyl having 5 to 10 carbon atoms (preferably cyclohexyl or adamantyl) is preferred. This explanation also applies to ^X1 and ^X2 in general formula (6').

In general formula (6'), R in the linking group "-C(-R) ₂ -" is hydrogen, alkyl or cycloalkyl, and the explanation of general formula (1) and formula (2) can also be cited for this alkyl or cycloalkyl. In particular, alkyl having 1 to 4 carbon atoms (e.g., methyl, ethyl, etc.) or cycloalkyl having 5 to 10 carbon atoms (preferably cyclohexyl or adamantyl) is preferred.

In addition, all or a part of the hydrogen in the chemical structure of the polycyclic aromatic compound represented by general formula (6) or (6') may be substituted with cyano, halogen, or deuterium. For example, in formula (6), hydrogen in rings A, B, and C (rings A to C are aryl or heteroaryl rings), substituents on rings A to C, and R (=aryl, heteroaryl, alkyl, cycloalkyl) when ^X1 and ^X2 are >N-R or >C(-R) ₂ may be substituted with cyano, halogen, or deuterium, and among these, embodiments in which all or a part of the hydrogen in aryl or heteroaryl is substituted with cyano, halogen, or deuterium can be exemplified. The halogen is fluorine, chlorine, bromine, or iodine, preferably fluorine, chlorine, or bromine, and more preferably fluorine or chlorine.

The explanations of general formula (1) and formula (2) can also be cited for the form in which at least one of ring A, ring B, ring C, ring a, ring b, ring c, the "formed ring", aryl and heteroaryl in the compound represented by formula (6) or (6') is condensed with at least one cycloalkane.

The explanation for general formula (2) can also be cited for the form in which any "-C(-R)=" (where R is R ¹ to R ¹¹ in the formula) in the ring a, ring b, and ring c of the compound represented by formula (6') is replaced with "-N=", and the form in which any "-C(-R)=C(-R)-" (where R is R ¹ to R ¹¹ in the formula) is replaced with "-N(-R)-", "-O-", or "-S-".

The compounds represented by general formula (6), formula (7), formula (8), and general formula (6'), formula (7'), and formula (8') can be produced in the same manner as the compounds represented by general formula (1) and formula (2).

<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 via the electron injection layer 107 to the light emitting layer 105. The electron transport layer 106 and the electron injection layer 107 are each formed by laminating or mixing one or more types of 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 that is responsible for injecting electrons from the cathode and transporting the electrons. It is desirable for the electron injection layer to have a high electron injection efficiency and efficiently transport the injected electrons. For this purpose, it is preferable for the material to have a large electron affinity, a large electron mobility, and excellent stability, and to be a material that is unlikely to generate impurities that become traps during manufacture and use. However, when considering the balance between the transport of holes and electrons, if the material mainly plays a role in efficiently preventing holes from the anode from flowing to the cathode without recombining, even if the electron transport ability is not that high, it has the effect of improving the luminous efficiency equivalent to a material with a high electron transport ability. Therefore, the electron injection/transport layer in this embodiment may also include the function of a layer that can efficiently block the movement of holes.

The material (electron transport material) forming the electron transport layer 106 or the electron injection layer 107 can be arbitrarily selected from compounds conventionally used as electron transport compounds in photoconductive materials and known compounds used in the electron injection layer and electron transport layer of organic EL elements. In the present invention, the electron transport material can be a polycyclic aromatic compound represented by the general formula (1) or formula (2).

Materials used in the electron transport layer or electron injection layer preferably contain at least one selected from compounds consisting of aromatic rings or heteroaromatic rings composed of one or more atoms selected from carbon, hydrogen, oxygen, sulfur, silicon, and phosphorus, pyrrole derivatives and their condensed ring derivatives, and metal complexes having electron-accepting nitrogen. Specific examples include condensed ring aromatic ring derivatives such as naphthalene and anthracene, styryl aromatic ring derivatives such as 4,4'-bis(diphenylethenyl)biphenyl, perinone derivatives, coumarin derivatives, naphthalimide derivatives, quinone derivatives such as anthraquinone and diphenoquinone, phosphorus oxide derivatives, carbazole derivatives, and indole derivatives. Metal complexes having electron-accepting nitrogen include, for example, hydroxyazole complexes such as hydroxyphenyloxazole complexes, azomethine complexes, tropolone metal complexes, flavonol metal complexes, and benzoquinoline metal complexes. These materials can be used alone or in combination with different materials.

Specific examples of other electron transport compounds include pyridine derivatives, naphthalene derivatives, anthracene derivatives, phenanthroline derivatives, perinone derivatives, coumarin derivatives, naphthalimide derivatives, anthraquinone derivatives, diphenoquinone derivatives, diphenylquinone derivatives, perylene derivatives, oxadiazole derivatives (such as 1,3-bis[(4-t-butylphenyl)1,3,4-oxadiazolyl]phenylene), thiophene derivatives, triazole derivatives (such as N-naphthyl-2,5-diphenyl-1,3,4-triazole), thiadiazole derivatives, metal complexes of oxine derivatives, quinolinol-based metal complexes, quinoxaline derivatives, polymers of quinoxaline derivatives, benzazole compounds, gallium complexes, pyrazole derivatives, perfluorinated phenylene derivatives, triazine derivatives, pyrazoles, etc. These include azine derivatives, benzoquinoline derivatives (such as 2,2'-bis(benzo[h]quinolin-2-yl)-9,9'-spirobifluorene), imidazopyridine derivatives, borane derivatives, benzimidazole derivatives (such as tris(N-phenylbenzimidazol-2-yl)benzene), benzoxazole derivatives, benzothiazole derivatives, quinoline derivatives, oligopyridine derivatives such as terpyridine, bipyridine derivatives, terpyridine derivatives (such as 1,3-bis(4'-(2,2':6'2"-terpyridinyl))benzene), naphthyridine derivatives (such as bis(1-naphthyl)-4-(1,8-naphthyridin-2-yl)phenylphosphine oxide), aldazine derivatives, carbazole derivatives, indole derivatives, phosphorus oxide derivatives, and bisstyryl derivatives.

Metal complexes having an electron-accepting nitrogen can also be used, such as quinolinol metal complexes, hydroxyazole complexes such as hydroxyphenyloxazole complexes, azomethine complexes, tropolone metal complexes, flavonol metal complexes, and benzoquinoline metal complexes.

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

Among the above-mentioned materials, borane derivatives, pyridine derivatives, fluoranthene derivatives, BO-based derivatives, anthracene derivatives, benzofluorene derivatives, phosphine oxide derivatives, pyrimidine derivatives, carbazole derivatives, triazine derivatives, benzimidazole derivatives, phenanthroline derivatives, and quinolinol-based metal complexes are preferred.

上記式（ＥＴＭ－１）中、Ｒ^１１およびＲ^１２は、それぞれ独立して、水素、アルキル、シクロアルキル、置換されていてもよいアリール、置換されているシリル、置換されていてもよい窒素含有複素環、またはシアノの少なくとも一つであり、Ｒ^１３～Ｒ^１６は、それぞれ独立して、置換されていてもよいアルキル、置換されていてもよいシクロアルキル、または置換されていてもよいアリールであり、Ｘは、置換されていてもよいアリーレンであり、Ｙは、置換されていてもよい炭素数１６以下のアリール、置換されているボリル、または置換されていてもよいカルバゾリルであり、そして、ｎはそれぞれ独立して０～３の整数である。また、「置換されていてもよい」または「置換されている」場合の置換基としては、アリール、ヘテロアリール、アルキルまたはシクロアルキルなどがあげられる。 <Borane derivatives>
The borane derivative is, for example, a compound represented by the following general formula (ETM-1), and is disclosed in detail in JP-A-2007-27587.

In the above formula (ETM-1), R ¹¹ and R ¹² are each independently at least one of hydrogen, alkyl, cycloalkyl, optionally substituted aryl, substituted silyl, optionally substituted nitrogen-containing heterocycle, or cyano, R ¹³ to R ¹⁶ are each independently optionally substituted alkyl, optionally substituted cycloalkyl, or optionally substituted aryl, X is optionally substituted arylene, Y is optionally substituted aryl having 16 or less carbon atoms, substituted boryl, or optionally substituted carbazolyl, and n is each independently an integer of 0 to 3. In addition, examples of the substituent in the case of "optionally substituted" or "substituted" include aryl, heteroaryl, alkyl, and cycloalkyl.

式（ＥＴＭ－１－１）中、Ｒ^１１およびＲ^１２は、それぞれ独立して、水素、アルキル、シクロアルキル、置換されていてもよいアリール、置換されているシリル、置換されていてもよい窒素含有複素環、またはシアノの少なくとも一つであり、Ｒ^１３～Ｒ^１６は、それぞれ独立して、置換されていてもよいアルキル、置換されていてもよいシクロアルキル、または置換されていてもよいアリールであり、Ｒ^２１およびＲ^２２は、それぞれ独立して、水素、アルキル、シクロアルキル、置換されていてもよいアリール、置換されているシリル、置換されていてもよい窒素含有複素環、またはシアノの少なくとも一つであり、Ｘ^１は、置換されていてもよい炭素数２０以下のアリーレンであり、ｎはそれぞれ独立して０～３の整数であり、そして、ｍはそれぞれ独立して０～４の整数である。また、「置換されていてもよい」または「置換されている」場合の置換基としては、アリール、ヘテロアリール、アルキルまたはシクロアルキルなどがあげられる。

式（ＥＴＭ－１－２）中、Ｒ^１１およびＲ^１２は、それぞれ独立して、水素、アルキル、シクロアルキル、置換されていてもよいアリール、置換されているシリル、置換されていてもよい窒素含有複素環、またはシアノの少なくとも一つであり、Ｒ^１３～Ｒ^１６は、それぞれ独立して、置換されていてもよいアルキル、置換されていてもよいシクロアルキル、または置換されていてもよいアリールであり、Ｘ^１は、置換されていてもよい炭素数２０以下のアリーレンであり、そして、ｎはそれぞれ独立して０～３の整数である。また、「置換されていてもよい」または「置換されている」場合の置換基としては、アリール、ヘテロアリール、アルキルまたはシクロアルキルなどがあげられる。 Among the compounds represented by the above general formula (ETM-1), compounds represented by the following general formula (ETM-1-1) and compounds represented by the following general formula (ETM-1-2) are preferred.

In formula (ETM-1-1), R ¹¹ and R ¹² are each independently at least one of hydrogen, alkyl, cycloalkyl, optionally substituted aryl, substituted silyl, optionally substituted nitrogen-containing heterocycle, or cyano, R ¹³ to R ¹⁶ are each independently at least one of optionally substituted alkyl, optionally substituted cycloalkyl, or optionally substituted aryl, R ²¹ and R ²² are each independently at least one of hydrogen, alkyl, cycloalkyl, optionally substituted aryl, substituted silyl, optionally substituted nitrogen-containing heterocycle, or cyano, X ¹ is an optionally substituted arylene having 20 or less carbon atoms, n is each independently an integer of 0 to 3, and m is each independently an integer of 0 to 4. In addition, examples of the substituent in the case of "optionally substituted" or "substituted" include aryl, heteroaryl, alkyl, and cycloalkyl.

In formula (ETM-1-2), R ¹¹ and R ¹² each independently represent at least one of hydrogen, alkyl, cycloalkyl, optionally substituted aryl, substituted silyl, optionally substituted nitrogen-containing heterocycle, or cyano, R ¹³ to R ¹⁶ each independently represent optionally substituted alkyl, optionally substituted cycloalkyl, or optionally substituted aryl, X ¹ is an optionally substituted arylene having 20 or less carbon atoms, and each n is independently an integer of 0 to 3. In addition, examples of the substituent in the case of "optionally substituted" or "substituted" include aryl, heteroaryl, alkyl, and cycloalkyl.

（各式中、Ｒ^ａは、それぞれ独立してアルキル基、シクロアルキル基または置換されていてもよいフェニル基である。） Specific examples of ^X1 include divalent groups represented by any of the following formulae (X-1) to (X-9): * in each structural formula represents a bonding position.

(In each formula, R ^a is independently an alkyl group, a cycloalkyl group, or an optionally substituted phenyl group.)

Specific examples of the borane derivative include the following compounds:

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

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

φ is an n-valent aryl ring (preferably an n-valent benzene ring, naphthalene ring, anthracene ring, fluorene ring, benzofluorene ring, phenalene ring, phenanthrene ring, or triphenylene ring), and n is an integer from 1 to 4.

In the above formula (ETM-2-1), R ¹¹ to R ¹⁸ are each independently hydrogen, alkyl (preferably alkyl having 1 to 24 carbon atoms), cycloalkyl (preferably cycloalkyl having 3 to 12 carbon atoms) or aryl (preferably aryl having 6 to 30 carbon atoms).

In the above formula (ETM-2-2), R ¹¹ and R ¹² are each independently hydrogen, alkyl (preferably alkyl having 1 to 24 carbon atoms), cycloalkyl (preferably cycloalkyl having 3 to 12 carbon atoms) or aryl (preferably aryl having 6 to 30 carbon atoms), and R ¹¹ and R ¹² may be bonded to form a ring.

In each formula, the "pyridine-based substituent" is any of the following formulae (Py-1) to (Py-15), and each pyridine-based substituent may be independently substituted with an alkyl having 1 to 4 carbon atoms or a cycloalkyl having 5 to 10 carbon atoms. In addition, the pyridine-based substituent may be bonded to the φ, anthracene ring, or fluorene ring in each formula via a phenylene group or naphthylene group. * in each structural formula indicates the bonding position.

The pyridine-based substituent is any one of the above formulae (Py-1) to (Py-15), and among these, any one of the following formulae (Py-21) to (Py-44) is preferable. In each structural formula, * indicates a bonding position.

At least one hydrogen in each pyridine derivative may be replaced with deuterium, and one of the two "pyridine-based substituents" in the above formulas (ETM-2-1) and (ETM-2-2) may be replaced with an aryl.

The "alkyl" in R ¹¹ to R ¹⁸ may be either linear or branched, and examples thereof include linear alkyl having 1 to 24 carbon atoms or branched alkyl having 3 to 24 carbon atoms. A preferred "alkyl" is an alkyl having 1 to 18 carbon atoms (branched alkyl having 3 to 18 carbon atoms). A more preferred "alkyl" is an alkyl having 1 to 12 carbon atoms (branched alkyl having 3 to 12 carbon atoms). An even more preferred "alkyl" is an alkyl having 1 to 6 carbon atoms (branched alkyl having 3 to 6 carbon atoms). An especially preferred "alkyl" is an alkyl having 1 to 4 carbon atoms (branched alkyl having 3 to 4 carbon atoms).

Specific examples of "alkyl" include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, s-butyl, t-butyl, n-pentyl, isopentyl, neopentyl, t-pentyl (t-amyl), n-hexyl, 1-methylpentyl, 3,3-dimethylbutyl, 2-ethylbutyl, n-heptyl, 1-methylhexyl, n-octyl, t-octyl (1,1,3,3-tetramethylbutyl), 1-methyl Examples of the aryl group include n-hexyl, n-butyl, n-butyl, n-butylheptyl, 2-ethylhexyl, 2-propylpentyl, n-nonyl, 2,2-dimethylheptyl, 2,6-dimethyl-4-heptyl, 3,5,5-trimethylhexyl, n-decyl, n-undecyl, 1-methyldecyl, n-dodecyl, n-tridecyl, 1-hexylheptyl, n-tetradecyl, n-pentadecyl, n-hexadecyl, n-heptadecyl, n-octadecyl, and n-eicosyl.
Further, for example, 1-ethyl-1-methylpropyl, 1,1-diethylpropyl, 1,1-dimethylbutyl, 1-ethyl-1-methylbutyl, 1,1,4-trimethylpentyl, 1,1,2-trimethylpropyl, 1,1-dimethyloctyl, 1,1-dimethylpentyl, 1,1-dimethylheptyl, 1,1,5-trimethylhexyl, 1-ethyl-1-methylhexyl, 1-ethyl-1,3-dimethylbutyl, 1,1,2,2-tetramethylpropyl, 1-butyl-1-methylpentyl, 1,1-diethylbutyl, 1-ethyl-1-methylpentyl, 1,1,3-trimethylbutyl, 1-propyl-1-methylpentyl, 1,1,2-trimethylpropyl, 1-ethyl-1,2,2-trimethylpropyl, 1-propyl-1-methylbutyl, and 1,1-dimethylhexyl.

The above description of alkyl can be used for the alkyl having 1 to 4 carbon atoms that substitutes the pyridine-based substituent.

The "cycloalkyl" in R ¹¹ to R ¹⁸ is, for example, a cycloalkyl having 3 to 12 carbon atoms. A preferred "cycloalkyl" is a cycloalkyl having 3 to 10 carbon atoms. A more preferred "cycloalkyl" is a cycloalkyl having 3 to 8 carbon atoms. An even more preferred "cycloalkyl" is a cycloalkyl having 3 to 6 carbon atoms.
Specific examples of "cycloalkyl" include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, methylcyclopentyl, cycloheptyl, methylcyclohexyl, cyclooctyl, and dimethylcyclohexyl.

As the "aryl" in R ¹¹ to R ¹⁸ , the preferred aryl is an aryl having 6 to 30 carbon atoms, the more preferred aryl is an aryl having 6 to 18 carbon atoms, the further more preferred aryl is an aryl having 6 to 14 carbon atoms, and the most preferred aryl is an aryl having 6 to 12 carbon atoms.

Specific examples of "aryls having 6 to 30 carbon atoms" include monocyclic aryls such as phenyl, fused bicyclic aryls such as (1-, 2-)naphthyl, fused tricyclic aryls such as acenaphthylene-(1-, 3-, 4-, 5-)yl, fluorene-(1-, 2-, 3-, 4-, 9-)yl, phenalene-(1-, 2-)yl, and (1-, 2-, 3-, 4-, 9-)phenanthryl, fused tetracyclic aryls such as triphenylene-(1-, 2-)yl, pyrene-(1-, 2-, 4-)yl, and naphthacene-(1-, 2-, 5-)yl, and fused pentacyclic aryls such as perylene-(1-, 2-, 3-)yl and pentacene-(1-, 2-, 5-, 6-)yl.

Preferred examples of "aryl having 6 to 30 carbon atoms" include phenyl, naphthyl, phenanthryl, chrysenyl, and triphenylenyl, more preferably phenyl, 1-naphthyl, 2-naphthyl, and phenanthryl, and particularly preferably phenyl, 1-naphthyl, and 2-naphthyl.

In the above formula (ETM-2-2), R ¹¹ and R ¹² may be bonded to form a ring, and as a result, cyclobutane, cyclopentane, cyclopentene, cyclopentadiene, cyclohexane, fluorene, indene, or the like may be spiro-bonded to the five-membered ring of the fluorene skeleton.

Specific examples of the pyridine derivative include the following compounds:

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

<Fluoranthene Derivatives>
The fluoranthene derivative is, for example, a compound represented by the following general formula (ETM-3), and is disclosed in detail in WO 2010/134352.

In the above formula (ETM-3), X ¹² to X ²¹ each represent hydrogen, halogen, linear, branched or cyclic alkyl, linear, branched or cyclic alkoxy, substituted or unsubstituted aryl, or substituted or unsubstituted heteroaryl. In the case where a group is substituted, examples of the substituent include aryl, heteroaryl, alkyl, and cycloalkyl.

Specific examples of the fluoranthene derivative include the following compounds:

<BO derivatives>
The BO derivative is, for example, a polycyclic aromatic compound represented by the following formula (ETM-4) or a polymer of a polycyclic aromatic compound having a plurality of structures represented by the following formula (ETM-4).

R ¹ to R ¹¹ are each independently hydrogen, aryl, heteroaryl, diarylamino, diheteroarylamino, arylheteroarylamino, alkyl, cycloalkyl, alkoxy, or aryloxy, in which at least one hydrogen may be substituted with an aryl, heteroaryl, alkyl, or cycloalkyl.

Adjacent groups among R ¹ to R ¹¹ may be bonded to each other to form an aryl ring or a heteroaryl ring together with the ring a, ring b, or ring c, and at least one hydrogen atom in the formed ring may be substituted with an aryl, heteroaryl, diarylamino, diheteroarylamino, arylheteroarylamino, alkyl, cycloalkyl, alkoxy, or aryloxy, and at least one hydrogen atom in these rings may be substituted with an aryl, heteroaryl, alkyl, or cycloalkyl.

In addition, at least one hydrogen atom in the compound or structure represented by formula (ETM-4) may be replaced with a halogen or deuterium.

For an explanation of the substituents and ring formation form in formula (ETM-4), the explanation of the polycyclic aromatic compound represented by general formula (1) or formula (2) above can be cited.

Specific examples of the BO derivative include the following compounds:

This BO derivative can be produced using known raw materials and known synthesis methods.

<Anthracene derivatives>
One example of the anthracene derivative is a compound represented by the following formula (ETM-5-1).

Each Ar is independently a divalent benzene or naphthalene, and each of R ¹ to R ⁴ is independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms, or an aryl group having 6 to 20 carbon atoms.

Each Ar can be independently selected from divalent benzene or naphthalene, and the two Ars may be different or the same, but are preferably the same from the viewpoint of ease of synthesis of the anthracene derivative. Ar bonds with pyridine to form a "moiety consisting of Ar and pyridine", and this moiety is bonded to anthracene as a group represented by any one of the following formulas (Py-1) to (Py-12). * in each structural formula indicates the bonding position.

Among these groups, a group represented by any one of the above formulas (Py-1) to (Py-9) is preferred, and a group represented by any one of the above formulas (Py-1) to (Py-6) is more preferred. The two "parts consisting of Ar and pyridine" bonded to anthracene may have the same or different structures, but from the viewpoint of ease of synthesis of anthracene derivatives, it is preferable that they have the same structure. However, from the viewpoint of element characteristics, it is preferable that the structures of the two "parts consisting of Ar and pyridine" are the same or different.

The alkyl having 1 to 6 carbon atoms in R ¹ to R ⁴ may be either linear or branched. That is, it is a linear alkyl having 1 to 6 carbon atoms or a branched alkyl having 3 to 6 carbon atoms. It is more preferably an alkyl having 1 to 4 carbon atoms (branched alkyl having 3 to 4 carbon atoms). Specific examples include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, s-butyl, t-butyl, n-pentyl, isopentyl, neopentyl, t-pentyl (t-amyl), n-hexyl, 1-methylpentyl, 3,3-dimethylbutyl, and 2-ethylbutyl, and methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, s-butyl, or t-butyl is preferred, and methyl, ethyl, or t-butyl is more preferred.

Specific examples of the cycloalkyl having 3 to 6 carbon atoms for R ¹ to R ⁴ include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, methylcyclopentyl, cycloheptyl, methylcyclohexyl, cyclooctyl, and dimethylcyclohexyl.

The aryl having 6 to 20 carbon atoms for R ¹ to R ⁴ is preferably an aryl having 6 to 16 carbon atoms, more preferably an aryl having 6 to 12 carbon atoms, and particularly preferably an aryl having 6 to 10 carbon atoms.

Specific examples of "aryl having 6 to 20 carbon atoms" include monocyclic aryls such as phenyl, (o-, m-, p-) tolyl, (2,3-, 2,4-, 2,5-, 2,6-, 3,4-, 3,5-) xylyl, mesityl (2,4,6-trimethylphenyl), (o-, m-, p-) cumenyl, bicyclic aryls such as (2-, 3-, 4-) biphenylyl, condensed bicyclic aryls such as (1-, 2-) naphthyl, tricyclic aryls such as 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 ... terphenyl-4-yl, o-terphenyl-2-yl, o-terphenyl-3-yl, o-terphenyl-4-yl, p-terphenyl-2-yl, p-terphenyl-3-yl, p-terphenyl-4-yl), fused tricyclic aryls anthracene-(1-,2-,9-)yl, acenaphthylene-(1-,3-,4-,5-)yl, fluorene-(1-,2-,3-,4-,9-)yl, phenalene-(1-,2-)yl, (1-,2-,3-,4-,9-)phenanthryl, fused tetracyclic aryls triphenylene-(1-,2-)yl, pyrene-(1-,2-,4-)yl, tetracene-(1-,2-,5-)yl, fused pentacyclic aryls perylene-(1-,2-,3-)yl, etc.

Preferred "aryl having 6 to 20 carbon atoms" is phenyl, biphenylyl, terphenylyl, or naphthyl, more preferably phenyl, biphenylyl, 1-naphthyl, 2-naphthyl, or m-terphenyl-5'-yl, even more preferably phenyl, biphenylyl, 1-naphthyl, or 2-naphthyl, and most preferably phenyl.

One example of the anthracene derivative is a compound represented by the following formula (ETM-5-2).

Each Ar ¹ is independently a single bond, or a divalent benzene, naphthalene, anthracene, fluorene, or phenalene.

Each Ar ² is independently an aryl having 6 to 20 carbon atoms, and the same explanation as for "aryl having 6 to 20 carbon atoms" in the above formula (ETM-5-1) can be cited. An aryl having 6 to 16 carbon atoms is preferable, an aryl having 6 to 12 carbon atoms is more preferable, and an aryl having 6 to 10 carbon atoms is particularly preferable. Specific examples include phenyl, biphenylyl, naphthyl, terphenylyl, anthracenyl, acenaphthylenyl, fluorenyl, phenalenyl, phenanthryl, triphenylenyl, pyrenyl, tetracenyl, perylenyl, etc.

R ¹ to R ⁴ each independently represent hydrogen, alkyl having 1 to 6 carbon atoms, cycloalkyl having 3 to 6 carbon atoms, or aryl having 6 to 20 carbon atoms, and the explanation in the above formula (ETM-5-1) can be cited.

Specific examples of these anthracene derivatives include the following compounds.

These anthracene derivatives can be produced using known raw materials and known synthesis methods.

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

Each Ar ¹ is independently an aryl having 6 to 20 carbon atoms, and the same explanation as for "aryl having 6 to 20 carbon atoms" in the above formula (ETM-5-1) can be cited. An aryl having 6 to 16 carbon atoms is preferable, an aryl having 6 to 12 carbon atoms is more preferable, and an aryl having 6 to 10 carbon atoms is particularly preferable. Specific examples include phenyl, biphenylyl, naphthyl, terphenylyl, anthracenyl, acenaphthylenyl, fluorenyl, phenalenyl, phenanthryl, triphenylenyl, pyrenyl, tetracenyl, perylenyl, etc.

Each Ar ² is independently hydrogen, an alkyl (preferably an alkyl having 1 to 24 carbon atoms), a cycloalkyl (preferably a cycloalkyl having 3 to 12 carbon atoms) or an aryl (preferably an aryl having 6 to 30 carbon atoms), and two Ar ² may be bonded to form a ring.

The "alkyl" in ^Ar2 may be either linear or branched, and examples thereof include linear alkyl having 1 to 24 carbon atoms or branched alkyl having 3 to 24 carbon atoms. A preferred "alkyl" is an alkyl having 1 to 18 carbon atoms (branched alkyl having 3 to 18 carbon atoms). A more preferred "alkyl" is an alkyl having 1 to 12 carbon atoms (branched alkyl having 3 to 12 carbon atoms). An even more preferred "alkyl" is an alkyl having 1 to 6 carbon atoms (branched alkyl having 3 to 6 carbon atoms). An especially preferred "alkyl" is an alkyl having 1 to 4 carbon atoms (branched alkyl having 3 to 4 carbon atoms). Specific examples of "alkyl" include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, s-butyl, t-butyl, n-pentyl, isopentyl, neopentyl, t-pentyl (t-amyl), n-hexyl, 1-methylpentyl, 3,3-dimethylbutyl, 2-ethylbutyl, n-heptyl, 1-methylhexyl, and the like.

The "cycloalkyl" in ^Ar2 includes, for example, cycloalkyl having 3 to 12 carbon atoms. A preferred "cycloalkyl" is cycloalkyl having 3 to 10 carbon atoms. A more preferred "cycloalkyl" is cycloalkyl having 3 to 8 carbon atoms. An even more preferred "cycloalkyl" is cycloalkyl having 3 to 6 carbon atoms. Specific examples of "cycloalkyl" include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, methylcyclopentyl, cycloheptyl, methylcyclohexyl, cyclooctyl, and dimethylcyclohexyl.

As the "aryl" in ^Ar2 , a preferable aryl is an aryl having 6 to 30 carbon atoms, a more preferable aryl is an aryl having 6 to 18 carbon atoms, an even more preferable aryl is an aryl having 6 to 14 carbon atoms, and an especially preferable aryl is an aryl having 6 to 12 carbon atoms.

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

Two ^Ar2 may be bonded to form a ring, and as a result, cyclobutane, cyclopentane, cyclopentene, cyclopentadiene, cyclohexane, fluorene, indene, or the like may be spiro-bonded to the five-membered ring of the fluorene skeleton.

Specific examples of the benzofluorene derivative include the following compounds:

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

Ｒ^５は、置換または無置換の、炭素数１～２０のアルキル、炭素数３～１６のシクロアルキル、炭素数６～２０のアリールまたは炭素数５～２０のヘテロアリールであり、
Ｒ^６は、ＣＮ、置換または無置換の、炭素数１～２０のアルキル、炭素数３～１６のシクロアルキル、炭素数１～２０のヘテロアルキル、炭素数６～２０のアリール、炭素数５～２０のヘテロアリール、炭素数１～２０のアルコキシまたは炭素数６～２０のアリールオキシであり、
Ｒ^７およびＲ^８は、それぞれ独立して、置換または無置換の、炭素数６～２０のアリールまたは炭素数５～２０のヘテロアリールであり、
Ｒ^９は酸素または硫黄であり、
ｊは０または１であり、ｋは０または１であり、ｒは０～４の整数であり、ｑは１～３の整数である。
ここで、置換されている場合の置換基としては、アリール、ヘテロアリール、アルキルまたはシクロアルキルなどがあげられる。 <Phosphine oxide derivatives>
The phosphine oxide derivative is, for example, a compound represented by the following formula (ETM-7-1). Details are also described in WO 2013/079217.

^R5 is a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 16 carbon atoms, an aryl group having 6 to 20 carbon atoms, or a heteroaryl group having 5 to 20 carbon atoms;
R ⁶ is CN, a substituted or unsubstituted alkyl having 1 to 20 carbon atoms, a cycloalkyl having 3 to 16 carbon atoms, a heteroalkyl having 1 to 20 carbon atoms, an aryl having 6 to 20 carbon atoms, a heteroaryl having 5 to 20 carbon atoms, an alkoxy having 1 to 20 carbon atoms, or an aryloxy having 6 to 20 carbon atoms;
R ⁷ and R ⁸ are each independently a substituted or unsubstituted aryl having 6 to 20 carbon atoms or a heteroaryl having 5 to 20 carbon atoms;
^R9 is oxygen or sulfur;
j is 0 or 1, k is 0 or 1, r is an integer of 0 to 4, and q is an integer of 1 to 3.
When substituted, the substituent may be an aryl, heteroaryl, alkyl or cycloalkyl.

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

R ¹ to R ³ may be the same or different and are selected from hydrogen, an alkyl group, a cycloalkyl group, an aralkyl group, an alkenyl group, a cycloalkenyl group, an alkynyl group, an alkoxy group, an alkylthio group, a cycloalkylthio group, an aryl ether group, an aryl thioether group, an aryl group, a heterocyclic group, a halogen, a cyano group, an aldehyde group, a carbonyl group, a carboxyl group, an amino group, a nitro group, a silyl group, and a condensed ring formed between adjacent substituents.

Ar ¹ may be the same or different and is an arylene group or a heteroarylene group. Ar ² may be the same or different and is an aryl group or a heteroaryl group. However, at least one of Ar ¹ and Ar ² has a substituent or forms a condensed ring with the adjacent substituent. n is an integer of 0 to 3, when n is 0, there is no unsaturated structural portion, and when n is 3, R ¹ does not exist.

Among these substituents, the alkyl group refers to a saturated aliphatic hydrocarbon group such as a methyl group, an ethyl group, a propyl group, or a butyl group, which may be unsubstituted or substituted. If the group is substituted, there is no particular limit to the type of substituent, and examples of the substituent include an alkyl group, an aryl group, and a heterocyclic group, which is also the case in the following descriptions. In addition, the number of carbon atoms in the alkyl group is not particularly limited, but is usually in the range of 1 to 20 from the standpoint of availability and cost.

The cycloalkyl group refers to a saturated alicyclic hydrocarbon group such as cyclopropyl, cyclohexyl, norbornyl, adamantyl, etc., which may be unsubstituted or substituted. The number of carbon atoms in the alkyl group is not particularly limited, but is usually in the range of 3 to 20.

The term "aralkyl group" refers to an aromatic hydrocarbon group that is linked via an aliphatic hydrocarbon, such as a benzyl group or a phenylethyl group, and both the aliphatic and aromatic hydrocarbons may be unsubstituted or substituted. The number of carbon atoms in the aliphatic portion is not particularly limited, but is usually in the range of 1 to 20.

Alkenyl groups refer to unsaturated aliphatic hydrocarbon groups containing a double bond, such as vinyl groups, allyl groups, and butadienyl groups, which may be unsubstituted or substituted. The number of carbon atoms in an alkenyl group is not particularly limited, but is usually in the range of 2 to 20.

The cycloalkenyl group refers to an unsaturated alicyclic hydrocarbon group containing a double bond, such as a cyclopentenyl group, a cyclopentadienyl group, or a cyclohexene group, which may be unsubstituted or substituted.

Alkynyl groups refer to unsaturated aliphatic hydrocarbon groups containing a triple bond, such as acetylenyl groups, which may be unsubstituted or substituted. The number of carbon atoms in an alkynyl group is not particularly limited, but is usually in the range of 2 to 20.

Alkoxy groups refer to aliphatic hydrocarbon groups, such as methoxy groups, that are linked via an ether bond, and the aliphatic hydrocarbon groups may be unsubstituted or substituted. The number of carbon atoms in the alkoxy group is not particularly limited, but is usually in the range of 1 to 20.

Alkylthio groups are groups in which the oxygen atom of the ether bond of an alkoxy group is replaced with a sulfur atom.

A cycloalkylthio group is a group in which the oxygen atom of the ether bond of a cycloalkoxy group is replaced with a sulfur atom.

The aryl ether group refers to an aromatic hydrocarbon group, such as a phenoxy group, that is bonded via an ether bond, and the aromatic hydrocarbon group may be unsubstituted or substituted. The number of carbon atoms in the aryl ether group is not particularly limited, but is usually in the range of 6 to 40.

An aryl thioether group is a group in which the oxygen atom of the ether bond of an aryl ether group is replaced with a sulfur atom.

The aryl group refers to an aromatic hydrocarbon group such as a phenyl group, a naphthyl group, a biphenyl group, a phenanthryl group, a terphenyl group, or a pyrenyl group. The aryl group may be unsubstituted or substituted. The number of carbon atoms in the aryl group is not particularly limited, but is usually in the range of 6 to 40.

The heterocyclic group refers to a cyclic structural group having atoms other than carbon, such as a furanyl group, a thiophenyl group, an oxazolyl group, a pyridyl group, a quinolinyl group, or a carbazolyl group, which may be unsubstituted or substituted. The number of carbon atoms in the heterocyclic group is not particularly limited, but is usually in the range of 2 to 30.

Halogen refers to fluorine, chlorine, bromine, and iodine.

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

In addition, the aliphatic hydrocarbons, alicyclic hydrocarbons, aromatic hydrocarbons, and heterocycles may be unsubstituted or substituted.

The silyl group refers to a silicon compound group such as a trimethylsilyl group, which may be unsubstituted or substituted. The number of carbon atoms in the silyl group is not particularly limited, but is usually in the range of 3 to 20. The number of silicon atoms is usually 1 to 6.

The fused ring formed between adjacent substituents is, for example, a conjugated or non-conjugated fused ring formed between Ar ¹ and R ² , Ar ¹ and R ³ , Ar ² and R ² , Ar ² and R ³ , R ² and R ³ , Ar ¹ and Ar ² , etc. Here, when n is 1, two R ^1s may form a conjugated or non-conjugated fused ring. These fused rings may contain a nitrogen, oxygen, or sulfur atom in the ring structure, or may be fused with another ring.

Specific examples of the phosphine oxide derivative include the following compounds:

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

<Pyrimidine derivatives>
The pyrimidine derivative is, for example, a compound represented by the following formula (ETM-8), preferably a compound represented by the following formula (ETM-8-1). Details are also described in WO 2011/021689.

Each Ar is independently an optionally substituted aryl or an optionally substituted heteroaryl. n is an integer from 1 to 4, preferably an integer from 1 to 3, and more preferably 2 or 3.

The "aryl" in "optionally substituted aryl" includes, for example, aryl having 6 to 30 carbon atoms, preferably aryl having 6 to 24 carbon atoms, more preferably aryl having 6 to 20 carbon atoms, and even more preferably aryl having 6 to 12 carbon atoms.

Specific examples of "aryl" include monocyclic aryl phenyl, bicyclic aryl (2-, 3-, 4-) biphenylyl, condensed bicyclic aryl (1-, 2-) naphthyl, tricyclic aryl 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, p-terphenyl-4-yl), condensed tricyclic aryl Examples of aryl include acenaphthylene-(1-,3-,4-,5-)yl, fluorene-(1-,2-,3-,4-,9-)yl, phenalene-(1-,2-)yl, (1-,2-,3-,4-,9-)phenanthryl, tetracyclic aryl quaterphenylyl (5'-phenyl-m-terphenyl-2-yl, 5'-phenyl-m-terphenyl-3-yl, 5'-phenyl-m-terphenyl-4-yl, m-quaterphenylyl), condensed tetracyclic aryl triphenylene-(1-,2-)yl, pyrene-(1-,2-,4-)yl, naphthacene-(1-,2-,5-)yl, condensed pentacyclic aryl perylene-(1-,2-,3-)yl, pentacene-(1-,2-,5-,6-)yl, etc.

The "heteroaryl" in "optionally substituted heteroaryl" includes, for example, heteroaryl having 2 to 30 carbon atoms, preferably heteroaryl having 2 to 25 carbon atoms, more preferably heteroaryl having 2 to 20 carbon atoms, even more preferably heteroaryl having 2 to 15 carbon atoms, and particularly preferably heteroaryl having 2 to 10 carbon atoms. In addition, examples of heteroaryl include heterocycles containing, in addition to carbon, 1 to 5 heteroatoms selected from oxygen, sulfur, and nitrogen as ring-constituting atoms.

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

The above aryl and heteroaryl may be substituted, for example, by the above aryl or heteroaryl, respectively.

Specific examples of the pyrimidine derivative include the following compounds:

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

<Carbazole derivatives>
The carbazole derivative is, for example, a compound represented by the following formula (ETM-9), or a multimer in which a plurality of such compounds are bonded together via single bonds, etc. Details are described in U.S. Patent Publication No. 2014/0197386.

Each Ar is independently an optionally substituted aryl or an optionally substituted heteroaryl. Each n is independently an integer from 0 to 4, preferably an integer from 0 to 3, and more preferably 0 or 1.

The "aryl" in "optionally substituted aryl" includes, for example, aryl having 6 to 30 carbon atoms, preferably aryl having 6 to 24 carbon atoms, more preferably aryl having 6 to 20 carbon atoms, and even more preferably aryl having 6 to 12 carbon atoms.

Specific examples of "aryl" include monocyclic aryl phenyl, bicyclic aryl (2-, 3-, 4-) biphenylyl, condensed bicyclic aryl (1-, 2-) naphthyl, tricyclic aryl 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, p-terphenyl-4-yl), condensed tricyclic aryl Examples of aryl include acenaphthylene-(1-,3-,4-,5-)yl, fluorene-(1-,2-,3-,4-,9-)yl, phenalene-(1-,2-)yl, (1-,2-,3-,4-,9-)phenanthryl, tetracyclic aryl quaterphenylyl (5'-phenyl-m-terphenyl-2-yl, 5'-phenyl-m-terphenyl-3-yl, 5'-phenyl-m-terphenyl-4-yl, m-quaterphenylyl), condensed tetracyclic aryl triphenylene-(1-,2-)yl, pyrene-(1-,2-,4-)yl, naphthacene-(1-,2-,5-)yl, condensed pentacyclic aryl perylene-(1-,2-,3-)yl, pentacene-(1-,2-,5-,6-)yl, etc.

The "heteroaryl" in "optionally substituted heteroaryl" includes, for example, heteroaryl having 2 to 30 carbon atoms, preferably heteroaryl having 2 to 25 carbon atoms, more preferably heteroaryl having 2 to 20 carbon atoms, even more preferably heteroaryl having 2 to 15 carbon atoms, and particularly preferably heteroaryl having 2 to 10 carbon atoms. In addition, examples of heteroaryl include heterocycles containing, in addition to carbon, 1 to 5 heteroatoms selected from oxygen, sulfur, and nitrogen as ring-constituting atoms.

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

The above aryl and heteroaryl may be substituted, for example, by the above aryl or heteroaryl, respectively.

The carbazole derivative may be a polymer in which a plurality of compounds represented by the above formula (ETM-9) are bonded together by single bonds or the like. In this case, in addition to single bonds, they may be bonded together by aryl rings (preferably polyvalent benzene rings, naphthalene rings, anthracene rings, fluorene rings, benzofluorene rings, phenalene rings, phenanthrene rings, or triphenylene rings).

Specific examples of the carbazole derivative include the following compounds.

This carbazole derivative can be produced using known raw materials and known synthesis methods.

<Triazine derivatives>
The triazine derivative is, for example, a compound represented by the following formula (ETM-10), preferably a compound represented by the following formula (ETM-10-1), the details of which are described in U.S. Patent Publication No. 2011/0156013.

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

The "aryl" in "optionally substituted aryl" includes, for example, aryl having 6 to 30 carbon atoms, preferably aryl having 6 to 24 carbon atoms, more preferably aryl having 6 to 20 carbon atoms, and even more preferably aryl having 6 to 12 carbon atoms.

Specific examples of "aryl" include monocyclic aryl phenyl, bicyclic aryl (2-, 3-, 4-) biphenylyl, condensed bicyclic aryl (1-, 2-) naphthyl, tricyclic aryl 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, p-terphenyl-4-yl), condensed tricyclic aryl Examples of aryl include acenaphthylene-(1-,3-,4-,5-)yl, fluorene-(1-,2-,3-,4-,9-)yl, phenalene-(1-,2-)yl, (1-,2-,3-,4-,9-)phenanthryl, tetracyclic aryl quaterphenylyl (5'-phenyl-m-terphenyl-2-yl, 5'-phenyl-m-terphenyl-3-yl, 5'-phenyl-m-terphenyl-4-yl, m-quaterphenylyl), condensed tetracyclic aryl triphenylene-(1-,2-)yl, pyrene-(1-,2-,4-)yl, naphthacene-(1-,2-,5-)yl, condensed pentacyclic aryl perylene-(1-,2-,3-)yl, pentacene-(1-,2-,5-,6-)yl, etc.

The "heteroaryl" in "optionally substituted heteroaryl" includes, for example, heteroaryl having 2 to 30 carbon atoms, preferably heteroaryl having 2 to 25 carbon atoms, more preferably heteroaryl having 2 to 20 carbon atoms, even more preferably heteroaryl having 2 to 15 carbon atoms, and particularly preferably heteroaryl having 2 to 10 carbon atoms. In addition, examples of heteroaryl include heterocycles containing, in addition to carbon, 1 to 5 heteroatoms selected from oxygen, sulfur, and nitrogen as ring-constituting atoms.

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

The above aryl and heteroaryl may be substituted, for example, by the above aryl or heteroaryl, respectively.

Specific examples of the triazine derivative include the following compounds:

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

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

φ is an n-valent aryl ring (preferably an n-valent benzene ring, naphthalene ring, anthracene ring, fluorene ring, benzofluorene ring, phenalene ring, phenanthrene ring or triphenylene ring), n is an integer from 1 to 4, and the "benzoimidazole-based substituent" is a substituent in which the pyridyl group in the "pyridine-based substituent" in the above formulas (ETM-2), (ETM-2-1) and (ETM-2-2) is replaced with a benzimidazole group, and at least one hydrogen in the benzimidazole derivative may be replaced with deuterium. * in the following structural formula indicates a bonding position.

R ¹¹ in the benzimidazole group is hydrogen, alkyl having 1 to 24 carbon atoms, cycloalkyl having 3 to 12 carbon atoms, or aryl having 6 to 30 carbon atoms, and the explanation of R ¹¹ in the above formulae (ETM-2-1) and (ETM-2-2) can be cited.

It is further preferred that φ is an anthracene ring or a fluorene ring, and in this case, the structure can be as described in the above formula (ETM-2-1) or formula (ETM-2-2), and R ¹¹ to R ¹⁸ in each formula can be as described in the above formula (ETM-2-1) or formula (ETM-2-2). In addition, in the above formula (ETM-2-1) or formula (ETM-2-2), two pyridine-based substituents are described as being bonded together, but when these are replaced with benzimidazole-based substituents, both pyridine-based substituents may be replaced with benzimidazole-based substituents (i.e., n=2), or one of the pyridine-based substituents may be replaced with a benzimidazole-based substituent and the other pyridine-based substituent may be replaced with R ¹¹ to R ¹⁸ (i.e., n=1). Furthermore, for example, at least one of R ¹¹ to R ¹⁸ in the above formula (ETM-2-1) may be replaced with a benzimidazole-based substituent, and the "pyridine-based substituent" may be replaced with R ¹¹ to R ¹⁸ .

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

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

<Phenanthroline Derivatives>
The phenanthroline derivative is, for example, a compound represented by the following formula (ETM-12) or formula (ETM-12-1), the details of which are described in WO 2006/021982.

φ is an n-valent aryl ring (preferably an n-valent benzene ring, naphthalene ring, anthracene ring, fluorene ring, benzofluorene ring, phenalene ring, phenanthrene ring, or triphenylene ring), and n is an integer from 1 to 4.

R ¹¹ to R ¹⁸ in each formula are each independently hydrogen, alkyl (preferably alkyl having 1 to 24 carbon atoms), cycloalkyl (preferably cycloalkyl having 3 to 12 carbon atoms), or aryl (preferably aryl having 6 to 30 carbon atoms). In addition, in the above formula (ETM-12-1), any of R ¹¹ to R ¹⁸ is bonded to φ which is an aryl ring.

At least one hydrogen in each phenanthroline derivative may be replaced with deuterium.

The alkyl, cycloalkyl and aryl in R ¹¹ to R ¹⁸ can be the same as those described for R ¹¹ to R ¹⁸ in formula (ETM-2). In addition to the above examples, φ can have the following structural formulae. Each R in the structural formulae below is independently hydrogen, methyl, ethyl, isopropyl, cyclohexyl, phenyl, 1-naphthyl, 2-naphthyl, biphenylyl or terphenylyl. In each structural formula, * indicates a bond position.

Specific examples of the phenanthroline derivative include 4,7-diphenyl-1,10-phenanthroline, 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline, 9,10-di(1,10-phenanthroline-2-yl)anthracene, 2,6-di(1,10-phenanthroline-5-yl)pyridine, 1,3,5-tri(1,10-phenanthroline-5-yl)benzene, 9,9'-difluoro-bi(1,10-phenanthroline-5-yl), bathocuproine, 1,3-bis(2-phenyl-1,10-phenanthroline-9-yl)benzene, and compounds represented by the following structural formula.

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

式中、Ｒ^１～Ｒ^６は、それぞれ独立して、水素、フッ素、アルキル、シクロアルキル、アラルキル、アルケニル、シアノ、アルコキシまたはアリールであり、ＭはＬｉ、Ａｌ、Ｇａ、ＢｅまたはＺｎであり、ｎは１～３の整数である。 <Quinolinol metal complexes>
The quinolinol metal complex is, for example, a compound represented by the following general formula (ETM-13).

In the formula, R ¹ to R ⁶ are each independently hydrogen, fluorine, alkyl, cycloalkyl, aralkyl, alkenyl, cyano, alkoxy or aryl; M is Li, Al, Ga, Be or Zn; and n is an integer of 1 to 3.

Specific examples of quinolinol-based metal complexes include 8-quinolinol lithium, tris(8-quinolinolato)aluminum, tris(4-methyl-8-quinolinolato)aluminum, tris(5-methyl-8-quinolinolato)aluminum, tris(3,4-dimethyl-8-quinolinolato)aluminum, tris(4,5-dimethyl-8-quinolinolato)aluminum, tris(4,6-dimethyl-8-quinolinolato)aluminum, and bis( 2-methyl-8-quinolinolate)(phenolate)aluminum, bis(2-methyl-8-quinolinolate)(2-methylphenolate)aluminum, bis(2-methyl-8-quinolinolate)(3-methylphenolate)aluminum, bis(2-methyl-8-quinolinolate)(4-methylphenolate)aluminum, bis(2-methyl-8-quinolinolate)(2-phenylphenolate)aluminum, bis(2-methyl-8-quinolinolate)(phenolate)aluminum linolinate)(3-phenylphenolate)aluminum, bis(2-methyl-8-quinolinate)(4-phenylphenolate)aluminum, bis(2-methyl-8-quinolinate)(2,3-dimethylphenolate)aluminum, bis(2-methyl-8-quinolinate)(2,6-dimethylphenolate)aluminum, bis(2-methyl-8-quinolinate)(3,4-dimethylphenolate)aluminum, bis(2-methyl bis(2-methyl-8-quinolinolate)(3,5-dimethylphenolate)aluminum, bis(2-methyl-8-quinolinolate)(3,5-di-t-butylphenolate)aluminum, bis(2-methyl-8-quinolinolate)(2,6-diphenylphenolate)aluminum, bis(2-methyl-8-quinolinolate)(2,4,6-triphenylphenolate)aluminum, bis(2-methyl-8-quinolinolate)(2,4,6-trimethylphenolate)aluminum bis(2-methyl-8-quinolinolate)(2,4,5,6-tetramethylphenolate)aluminum, bis(2-methyl-8-quinolinolate)(1-naphtholate)aluminum, bis(2-methyl-8-quinolinolate)(2-naphtholate)aluminum, bis(2,4-dimethyl-8-quinolinolate)(2-phenylphenolate)aluminum, bis(2,4-dimethyl-8-quinolinolate)(3-phenylphenolate)aluminum phenylphenolate)aluminum, bis(2,4-dimethyl-8-quinolinolate)(4-phenylphenolate)aluminum, bis(2,4-dimethyl-8-quinolinolate)(3,5-dimethylphenolate)aluminum, bis(2,4-dimethyl-8-quinolinolate)(3,5-di-t-butylphenolate)aluminum, bis(2-methyl-8-quinolinolate)aluminum-μ-oxo-bis(2-methyl-8-quinolinolate) ) aluminum, bis(2,4-dimethyl-8-quinolinolato)aluminum-μ-oxo-bis(2,4-dimethyl-8-quinolinolato)aluminum, bis(2-methyl-4-ethyl-8-quinolinolato)aluminum-μ-oxo-bis(2-methyl-4-ethyl-8-quinolinolato)aluminum, bis(2-methyl-4-methoxy-8-quinolinolato)aluminum-μ-oxo-bis(2-methyl-4-methoxy-8-quinolinolato)aluminum linolinate) aluminum, bis(2-methyl-5-cyano-8-quinolinate) aluminum-μ-oxo-bis(2-methyl-5-cyano-8-quinolinate) aluminum, bis(2-methyl-5-trifluoromethyl-8-quinolinate) aluminum-μ-oxo-bis(2-methyl-5-trifluoromethyl-8-quinolinate) aluminum, bis(10-hydroxybenzo[h]quinoline) beryllium, etc.

This quinolinol metal complex can be produced using known raw materials and known synthesis methods.

ベンゾチアゾール誘導体は、例えば下記式（ＥＴＭ－１４－２）で表される化合物である。

<Thiazole Derivatives and Benzothiazole Derivatives>
The thiazole derivative is, for example, a compound represented by the following formula (ETM-14-1).

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

In each formula, φ is an n-valent aryl ring (preferably an n-valent benzene ring, naphthalene ring, anthracene ring, fluorene ring, benzofluorene ring, phenalene ring, phenanthrene ring or triphenylene ring), and n is an integer from 1 to 4. The "thiazole-based substituent" and "benzothiazole-based substituent" are substituents in which the pyridyl group in the "pyridine-based substituent" in the above formulae (ETM-2), (ETM-2-1) and (ETM-2-2) is replaced with the below-mentioned thiazole group or benzothiazole group, and at least one hydrogen atom in the thiazole derivative and benzothiazole derivative may be replaced with a deuterium atom. * in the following structural formulas indicates a bond position.

It is further preferred that φ is an anthracene ring or a fluorene ring, and in this case, the structure can be explained with reference to the above formula (ETM-2-1) or formula (ETM-2-2), and R ¹¹ to R ¹⁸ in each formula can be explained with reference to the above formula (ETM-2-1) or formula (ETM-2-2). In addition, in the above formula (ETM-2-1) or formula (ETM-2-2), two pyridine-based substituents are explained as being bonded together, but when these are replaced with a thiazole-based substituent (or a benzothiazole-based substituent), both pyridine-based substituents may be replaced with a thiazole-based substituent (or a benzothiazole-based substituent) (i.e., n=2), or one of the pyridine-based substituents may be replaced with a thiazole-based substituent (or a benzothiazole-based substituent) and the other pyridine-based substituent may be replaced with R ¹¹ to R ¹⁸ (i.e., n=1). Furthermore, for example, at least one of R ¹¹ to R ¹⁸ in the above formula (ETM-2-1) may be replaced with a thiazole-based substituent (or a benzothiazole-based substituent) to replace the "pyridine-based substituent" with R ¹¹ to R ¹⁸ .

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

The electron transport layer or the electron injection layer may further contain a substance capable of reducing the material forming the electron transport layer or the electron injection layer. As the reducing substance, various substances can be used as long as they have a certain degree of reducing ability. For example, at least one selected from the group consisting of alkali metals, alkaline earth metals, rare earth metals, oxides of alkali metals, halides of alkali metals, oxides of alkaline earth metals, halides of alkaline earth metals, oxides of rare earth metals, halides of rare earth metals, organic complexes of alkali metals, organic complexes of alkaline earth metals, and organic complexes of rare earth metals 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 alkaline earth metals such as Ca (2.9 eV), Sr (2.0-2.5 eV), or Ba (2.52 eV), with substances with a work function of 2.9 eV or less being particularly preferred. Of these, more preferred reducing substances are alkali metals such as K, Rb, or Cs, even more preferred are Rb or Cs, and most preferred is Cs. These alkali metals have particularly high reducing ability, and by adding a relatively small amount to the material forming the electron transport layer or electron injection layer, the luminance of the organic EL element can be improved and the lifespan can be extended. In addition, 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 preferred, and in particular, a combination containing Cs, such as a combination of Cs and Na, Cs and K, Cs and Rb, or Cs, Na and K, is preferred. By containing Cs, the reducing ability can be efficiently exerted, and by adding it to the material forming the electron transport layer or electron injection layer, the luminance of the organic EL element can be improved and the life 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 is a material that can efficiently inject electrons into the organic layer, but the same material as the material for forming the anode 102 can be used. Among them, metals such as tin, indium, calcium, aluminum, silver, copper, nickel, chromium, gold, platinum, iron, zinc, lithium, sodium, potassium, cesium, and magnesium, or alloys thereof (magnesium-silver alloy, magnesium-indium alloy, aluminum-lithium alloy such as lithium fluoride/aluminum, etc.), etc. are preferable. In order to increase the electron injection efficiency and improve the device characteristics, lithium, sodium, potassium, cesium, calcium, magnesium, or alloys containing these low work function metals are effective. However, these low work function metals are generally unstable in air. To improve this point, for example, a method is known in which a trace amount of lithium, cesium, or magnesium is doped into the organic layer to use a highly stable electrode. Other dopants that can be used include inorganic salts such as lithium fluoride, cesium fluoride, lithium oxide, and cesium oxide. However, they are not limited to these.

Furthermore, preferred examples include laminating metals such as platinum, gold, silver, copper, iron, tin, aluminum, and indium, or alloys using these metals, as well as inorganic materials such as silica, titania, and silicon nitride, polyvinyl alcohol, vinyl chloride, and hydrocarbon polymer compounds, in order to protect the electrodes. There are no particular limitations on the method of producing these electrodes, and they can be produced by resistance heating, electron beam deposition, sputtering, ion plating, coating, or the like, as long as electrical conductivity can be obtained.

<Binder that may be used in each layer>
The materials used for the hole injection layer, hole transport layer, light emitting layer, electron transport layer and electron injection layer can form each layer alone, but they can also be used as a polymer binder by being dispersed in a solvent-soluble resin such as polyvinyl chloride, polycarbonate, polystyrene, poly(N-vinylcarbazole), polymethyl methacrylate, polybutyl methacrylate, polyester, polysulfone, polyphenylene oxide, polybutadiene, hydrocarbon resin, ketone resin, phenoxy resin, polyamide, ethyl cellulose, vinyl acetate resin, ABS resin, polyurethane resin, or a curable resin such as phenol resin, xylene resin, petroleum resin, urea resin, melamine resin, unsaturated polyester resin, alkyd resin, epoxy resin, silicone resin, or the like.

<Method for Producing Organic Electroluminescent Device>
Each layer constituting an organic EL element can be formed by forming the material to be formed 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 or casting, coating, etc. The thickness of each layer thus formed is not particularly limited and can be set appropriately according to the properties of the material, but is usually in the range of 2 nm to 5000 nm. The thickness can usually be measured with a quartz crystal oscillation type film thickness measuring device, etc. When forming a thin film by vapor deposition, the vapor deposition conditions vary depending on the type of material, the intended crystal structure and association structure of the film, etc. The vapor deposition conditions are generally preferably set appropriately in the range of boat heating temperature +50 to +400°C, vacuum degree 10 ^-6 to 10 ^-3 Pa, vapor deposition rate 0.01 to 50 nm/sec, substrate temperature -150 to +300°C, and film thickness 2 nm to 5 μm.

Next, as an example of a method for producing an organic EL element, a method for producing an organic EL element consisting of an anode, a hole injection layer, a hole transport layer, a light-emitting layer consisting of a host material and a dopant material, an electron transport layer, an electron injection layer, and a cathode will be described. After forming a thin film of an anode material on a suitable substrate by a deposition method or the like to produce an anode, 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 on the anode to form a thin film to produce a light-emitting layer, an electron transport layer and an electron injection layer are formed on the light-emitting layer, and a thin film of a cathode material is further formed by a deposition method or the like to produce a cathode, thereby obtaining the desired organic EL element. It is also possible to reverse the order of production in the above-mentioned organic EL element, producing the elements in the order of cathode, electron injection layer, electron transport layer, light-emitting layer, hole transport layer, hole injection layer, and anode.

When applying a DC voltage to the organic EL element obtained in this way, the anode should be set to + and the cathode to -. When a voltage of about 2 to 40 V is applied, light emission can be observed from the transparent or semi-transparent electrode side (anode or cathode, or both). This organic EL element also emits light when a pulsed current or AC current is applied. The waveform of the AC current applied can be any waveform.

<Application examples of organic electroluminescent devices>
The present invention can also be applied to a display device having an organic EL element or a lighting device having an organic EL element.
A display device or lighting device including an organic EL element can be manufactured by a known method, for example by connecting the organic EL element according to this embodiment to a known driving device, and can be driven appropriately using a known driving method such as DC driving, pulse driving, or AC driving.

Examples of display devices include panel displays such as color flat panel displays, and flexible displays such as flexible color organic electroluminescent (EL) displays (see, for example, JP-A-10-335066, JP-A-2003-321546, JP-A-2004-281086, etc.). Display methods include, for example, matrix and segment methods. Note that matrix display and segment display may coexist in the same panel.

In a matrix, the pixels for display are arranged two-dimensionally, such as in a grid or mosaic pattern, and a collection of pixels displays characters and images. The shape and size of the pixels are determined by the application. For example, square pixels with sides of 300 μm or less are usually used to display images and characters on computers, monitors, and televisions, and pixels with sides on the order of mm are used for large displays such as display panels. For monochrome display, pixels of the same color can be arranged, but for color display, red, green, and blue pixels are displayed side by side. In this case, there are typically delta types and stripe types. The driving method for this matrix can be either line sequential driving method or active matrix. Line sequential driving has the advantage of being simpler in structure, but when considering operating characteristics, active matrix may be superior, so it is necessary to use it according to the application.

In the segment method, a pattern is formed to display predetermined information, and a specific area is illuminated. Examples include the time and temperature displays on digital clocks and thermometers, the operating status displays on audio equipment and induction cookers, and panel displays on automobiles.

Examples of lighting devices include lighting devices for indoor lighting, backlights for liquid crystal display devices, etc. (see, for example, JP 2003-257621 A, JP 2003-277741 A, JP 2004-119211 A, etc.). Backlights are mainly used for the purpose of improving the visibility of non-self-luminous display devices, and are used in liquid crystal display devices, clocks, audio devices, automobile panels, display boards, signs, etc. In particular, for liquid crystal display devices, and especially for backlights for personal computers, where thinning is an issue, it is difficult to make them thin because conventional methods use fluorescent lamps and light guide plates, so the backlights using the light-emitting elements according to this embodiment are characterized by their thinness and light weight.

3-2. Other Organic Devices The polycyclic aromatic compound according to the present invention can be used for producing organic field effect transistors or organic thin-film solar cells, in addition to the organic electroluminescent devices described above.

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

The structure of an organic field effect transistor may be such that a source electrode and a drain electrode are provided in contact with an organic semiconductor active layer formed using the polycyclic aromatic compound according to the present invention, and a gate electrode is provided sandwiching an insulating layer (dielectric layer) in contact with the organic semiconductor active layer. Examples of the element structure include the following structure.
(1) Substrate/gate electrode/insulator layer/source electrode/drain electrode/organic semiconductor active layer (2) Substrate/gate electrode/insulator layer/organic semiconductor active layer/source electrode/drain electrode (3) Substrate/organic semiconductor active layer/source electrode/drain electrode/insulator layer/gate electrode (4) Substrate/source electrode/drain electrode/organic semiconductor active layer/insulator layer/gate electrode An organic field effect transistor configured in this manner can be used as a pixel driving switching element for active matrix driving liquid crystal displays and organic electroluminescence displays.

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

The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these. First, a synthesis example of a polycyclic aromatic compound will be described below.

Synthesis Example (1): Synthesis of Compound (1-901)

Under a nitrogen atmosphere, compound (I-1) (3.05 g, 10 mmol), compound (I-2) (3.35 g, 12 mmol), potassium carbonate (4.10 g, 30 mmol), bis(di-tert-butyl(4-dimethylaminophenyl)phosphine)dichloropalladium(II) (Pd-132: 0.0783 g, 0.1 mmol) and tetrabutylammonium bromide (TBAB: 0.97 g, 3 mmol) were placed in a flask, toluene (30 ml) and distilled water (15 ml) were added, and the mixture was heated under reflux for 2 hours. The precipitated solid was filtered by suction and washed with water and heptane, and the obtained crude product was purified with a silica gel short column (eluent: chlorobenzene) to obtain compound (1-901) as a white solid (yield: 0.56 g).

Synthesis Example (2): Synthesis of Compound (1-902)

Under a nitrogen atmosphere, compound (I-3) (3.08 g, 10 mmol), compound (I-2) (3.35 g, 12 mmol), potassium carbonate (4.08 g, 30 mmol), bis(di-tert-butyl(4-dimethylaminophenyl)phosphine)dichloropalladium(II) (Pd-132: 0.0775 g, 0.1 mmol) and tetrabutylammonium bromide (TBAB: 1.00 g, 3 mmol) were placed in a flask, toluene (30 ml) and distilled water (15 ml) were added, and the mixture was heated under reflux for 14 hours. The precipitated solid was filtered by suction and washed with water and heptane, and the obtained crude product was purified with a silica gel short column (eluent: chlorobenzene) to obtain compound (1-902) as a white solid (yield: 1.27 g).

By appropriately changing the raw material compounds, other polycyclic aromatic compounds of the present invention can be synthesized according to the methods described in the above synthesis examples.

Next, in order to explain the present invention in more detail, examples of organic EL devices using the compounds of the present invention are shown, but the present invention is not limited to these.

<Evaluation of deposition type organic EL elements>
Organic EL elements according to Example 1, Example 2 and Comparative Example 1 were fabricated, and the driving voltage (V) and external quantum efficiency (%), which are characteristics at 1000 cd/ ^m2 emission, were measured.

The quantum efficiency of a light-emitting element can be classified into internal quantum efficiency and external quantum efficiency. The internal quantum efficiency indicates the proportion of external energy injected as electrons (or holes) into the light-emitting layer of the light-emitting element that is converted purely into photons. On the other hand, the external quantum efficiency is calculated based on the amount of these photons that are emitted to the outside of the light-emitting element. Some of the photons generated in the light-emitting layer are absorbed or continue to be reflected inside the light-emitting element, and are not emitted to the outside of the light-emitting element, so the external quantum efficiency is lower than the internal quantum efficiency.

The method for measuring the external quantum efficiency is as follows. Using an Advantest voltage/current generator R6144, a voltage was applied so that the luminance of the element was 1000 cd/ ^m2 , and the element was made to emit light. Using a TOPCON spectroradiometer SR-3AR, the spectral radiance of the visible light region was measured from a direction perpendicular to the light-emitting surface. Assuming that the light-emitting surface is a completely diffusing surface, the measured spectral radiance value of each wavelength component was divided by the wavelength energy and multiplied by π to obtain the number of photons at each wavelength. Next, the number of photons was integrated over the entire wavelength range observed to obtain the total number of photons emitted from the element. The value obtained by dividing the applied current value by the elementary charge was taken as the number of carriers injected into the element, and the value obtained by dividing the total number of photons emitted from the element by the number of carriers injected into the element was taken as the external quantum efficiency.

The material configurations of the layers in the organic EL elements according to Example 1, Example 2 and Comparative Example 1 are shown in Table 1 below.

In Table 1, "HI" is N ⁴ ,N ^4' -diphenyl-N ⁴ ,N ^4' -bis(9-phenyl-9H-carbazol-3-yl)-[1,1'-biphenyl]-4,4'-diamine, "HAT-CN" is 1,4,5,8,9,12-hexaazatriphenylene hexacarbonitrile, "HT-1" is N-([1,1'-biphenyl]-4-yl)-9,9-dimethyl-N-(4-(9-phenyl-9H-carbazol-3-yl)phenyl)-9H-fluoren-2-amine, "Host1" is 9-phenyl-10-(4-phenylnaphthalen-1-yl)anthracene, and "ET-1" is 9-(4'-(dimesitylboranyl)-[1,1'-binaphthalen]-4-yl)-9H-carbazole. The chemical structure is shown below together with "Dopant1".

Example 1
A 26 mm × 28 mm × 0.7 mm glass substrate (manufactured by Optoscience Co., Ltd.) was prepared by polishing an ITO film formed to a thickness of 180 nm by sputtering to 120 nm, and used as a transparent support substrate. This transparent support substrate was fixed to a substrate holder of a commercially available deposition apparatus (manufactured by Nagasu Sangyo Co., Ltd.), and a tungsten deposition boat containing HI, HAT-CN, HT-1, Host1, Dopant1, ET-1, compound (1-901), LiF, and aluminum was attached.

The following layers were formed in sequence on the ITO film of the transparent support substrate. The vacuum chamber was depressurized to 5×10 ⁻⁴ Pa, and first, HI was heated and evaporated to a thickness of 65 nm to form a hole injection layer 1. Next, HAT-CN was heated and evaporated to a thickness of 5 nm to form a hole injection layer 2. Next, HT-1 was heated and evaporated to a thickness of 90 nm to form a hole transport layer. Next, Host1 and Dopant1 were heated simultaneously and evaporated to a thickness of 25 nm to form a light emitting layer. The evaporation rate was adjusted so that the mass ratio of Host1 to Dopant1 was approximately 95:5. Next, ET-1 was heated and evaporated to a thickness of 20 nm to form an electron transport layer 1. Next, compound (1-901) was heated and evaporated to a thickness of 10 nm to form an electron transport layer 2. The evaporation rate of each layer was 0.01 to 1 nm/sec. Then, LiF was heated and evaporated at a deposition rate of 0.01 to 0.1 nm/sec to a thickness of 1 nm, and then aluminum was heated and evaporated to a thickness of 100 nm to form a cathode, thereby obtaining an organic EL device. At this time, the deposition rate was adjusted between 0.1 nm and 10 nm/sec.

Example 2
An organic EL element was prepared in the same manner as in Example 1, except that the electron transport layer 2 was replaced with the compound (1-902).

<Comparative Example 1>
An organic EL element was prepared in the same manner as in Example 1, except that the electron transport layer 2 was changed to ET-1 (that is, a 30 nm-thick electron transport layer was formed using only ET-1).

A direct current voltage was applied to the ITO electrode as the anode and the aluminum electrode as the cathode, and the characteristics at 1000 cd/ ^m2 emission were measured, with the results shown in Table 2 below. From these results, it is clear that the driving voltage can be reduced by using the compound of the present invention as an electron transport layer.

<Inference of electron transport properties using TOF measurements>
By measuring the time of flight (TOF), the electron mobility of a material can be measured separately from its electron injection property. The electron mobility of a comparative compound (BPy-TP2), which is a representative electron injection material having a bipyridyl group, was measured as a comparative example, and the electron mobility of a reference compound (BO2) having the same basic structure as the polycyclic aromatic compound of the present invention was measured as a reference example.

The electron mobility at an applied electric field of 0.4 MV/cm was 9.7×10 ⁻⁷ cm ² /V·s for the comparative compound (BPy-TP2) and 1.6×10 ⁻⁶ cm ² /V·s for the reference compound (BO2). This result shows that the basic skeleton portion of the polycyclic aromatic compound of the present invention has superior electron transport properties compared to the comparative compound. Therefore, a polycyclic aromatic compound having a nitrogen-containing substituent (a group of the above formula (BiN)) that enhances electron injection properties, such as bipyridyl, introduced into this basic skeleton can be expected to be an excellent material for an electron transport layer or electron injection layer.

As described above, some of the compounds according to the present invention have been evaluated as materials for organic EL devices and shown to be excellent materials, but other compounds that have not been evaluated also have the same basic skeleton and have a similar structure overall, and those skilled in the art will understand that they are similarly excellent materials for organic EL devices.

In the present invention, by introducing a nitrogen-containing substituent of formula (BiN) into a polycyclic aromatic compound of formula (1) in which multiple aromatic rings are linked by boron atoms and oxygen atoms, etc., it is possible to provide a material for an electron transport layer or an electron injection layer that has both high electron injection properties and electron mobility, and this makes it possible to fabricate an organic device with a low driving voltage, such as an organic EL element.

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 (9)

A polycyclic aromatic compound represented by the following general formula (2) :

In the above formula (2),
R ¹ to R ¹¹ each independently represent a hydrogen atom, a group represented by the formula (BiN-1), or a group represented by the formula (BiN-2) , at least one of R ¹ to R ¹¹ represents a group represented by the formula (BiN-1) or a group represented by the formula (BiN-2) , * represents a bonding position,
At least one hydrogen in the compound may be replaced with cyano, halogen, or deuterium. The polycyclic aromatic compound according to claim 1 , which is represented by any one of the following structural formulas :

A material for an organic device, comprising the polycyclic aromatic compound according to claim 1 or 2 . The material for an organic device according to claim 3 , which is a material for an organic electroluminescent element, a material for an organic field effect transistor, or a material for an organic thin-film solar cell. The material for an organic device according to claim 4 , wherein the material for an organic electroluminescent device is a material for an electron transport layer or a material for an electron injection layer. 6. An organic electroluminescent device comprising a pair of electrodes consisting of an anode and a cathode, a light-emitting layer disposed between the pair of electrodes, and at least one of an electron transport layer and an electron injection layer disposed between the cathode and the light-emitting layer, wherein at least one of the electron transport layer and the electron injection layer contains the material for an organic device according to claim 5 . 7. The organic electroluminescence device according to claim 6, wherein at least one of the electron transport layer and the electron injection layer contains at least one selected from the group consisting of borane derivatives, pyridine derivatives, fluoranthene derivatives, BO-based derivatives, anthracene derivatives, benzofluorene derivatives, phosphine oxide derivatives, pyrimidine derivatives, carbazole derivatives, triazine derivatives, benzimidazole derivatives, phenanthroline derivatives, and quinolinol-based metal complexes. 8. The organic electroluminescent device according to claim 6, wherein at least one of the electron transport layer and the electron injection layer contains at least one selected from the group consisting of alkali metals, alkaline earth metals, rare earth metals, oxides of alkali metals, oxides of alkaline earth metals, oxides of rare earth metals, halides of alkali metals, halides of alkaline earth metals, halides of rare earth metals, organic complexes of alkali metals, organic complexes of alkaline earth metals , and organic complexes of rare earth metals. A display device or a lighting device comprising the organic electroluminescent device according to any one of claims 6 to 8 .