JP7624648B2 - Polycyclic aromatic compounds - Google Patents

Description

The present invention relates to a polycyclic aromatic compound. The present invention also relates to a material for an organic device, an organic electroluminescent device, and a display device and a lighting device, each of which contains the polycyclic aromatic compound.

Display devices using electroluminescent light-emitting elements have been extensively studied because they can be made thin and energy-efficient. In addition, organic electroluminescent elements (sometimes referred to as "organic EL elements" or simply "elements" in this specification) made from organic materials have been actively studied because they can be easily made lighter and larger. 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.

Among them, Patent Document 1 discloses that polycyclic aromatic compounds in which aromatic rings are linked by hetero elements such as boron, phosphorus, oxygen, nitrogen, and sulfur are useful as materials for organic electroluminescent devices, etc. It has been reported that these polycyclic aromatic compounds have a large HOMO-LUMO gap and high triplet excitation energy (E _T ) and exhibit thermally activated delayed fluorescence, and are therefore particularly useful as fluorescent materials for organic electroluminescent devices.

International Publication No. 2015/102118

As described 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, it is desirable to develop materials made of compounds that are different from conventional ones. The objective of the present invention is to provide a new material that is useful as a material for organic devices such as organic EL elements.

The present inventors conducted intensive research to solve the above problems, and succeeded in producing a new compound as a polycyclic aromatic compound in which aromatic rings are linked by heteroelements such as boron, phosphorus, oxygen, nitrogen, and sulfur. They also discovered that an excellent organic EL element can be obtained by constructing an organic EL element by disposing a layer containing this polycyclic aromatic compound between a pair of electrodes, and thus completed the present invention. In other words, the present invention provides the following polycyclic aromatic compounds, and further provides materials for organic devices containing the following polycyclic aromatic compounds.

式（１Ａ）および式（１Ｂ）中、
Ａ環およびＢ環は、それぞれ独立して、置換されていてもよいアリール環または置換されていてもよいヘテロアリール環であり、
Ｒ^XD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、破線が－Ｘ－または単結合となってＡ環またはＢ環の少なくとも１つと結合していてもよく、
Ａ環、Ｂ環またはＲ^XDの少なくとも１つにおける前記アリール環またはヘテロアリール環は式（１Ｂ）で表される部分構造に結合しており、
式（１Ｂ）で表される部分構造は２つの＊の位置で前記アリール環またはヘテロアリール環の環上で隣接する２つの原子にそれぞれ結合し、
Ｃ環は、それぞれ独立して、置換されていてもよいアリール環または置換されていてもよいヘテロアリール環であり、
Ｒ^XE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、破線が－Ｘ－または単結合となってＣ環と結合していてもよく、また、破線が－Ｘ－または単結合となって式（１Ｂ）で表される部分構造が結合している環と（＊）の位置で結合していてもよく、
Ｙは、それぞれ独立して、Ｂ、Ｐ、Ｐ＝ＯまたはＰ＝Ｓであり、
Ｘは、それぞれ独立して、＞Ｃ（－Ｒ）₂、＞Ｎ－Ｒ、＞Ｏ、＞Ｓｉ（－Ｒ）₂または＞Ｓ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および＞Ｓｉ（－Ｒ）₂のＲは、それぞれ独立して、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、また連結基によって互いに結合していてもよく、また、前記＞Ｎ－Ｒ、前記＞Ｃ（－Ｒ）₂、および前記＞Ｓｉ（－Ｒ）₂のＲの少なくとも１つは連結基または単結合によりＡ環、Ｂ環、Ｃ環、Ｒ^XD、またはＲ^XEの少なくとも１つと結合していてもよく、
Ｘは、少なくとも１つが＞Ｎ－Ｒであり、＞Ｎ－ＲであるＸの少なくとも１つにおけるＲは前記Ａ環、Ｂ環、Ｃ環、Ｒ^XD、またはＲ^XEの１つと結合して式（Ａ１０）で表される部分構造を形成しており、式（Ａ１０）中、Ｒ^A1～Ｒ^A4はそれぞれ独立して、水素、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、Ｒ^A1～Ｒ^A4の任意の２～４個は連結基または単結合により互いに結合していてもよく、式（Ａ１０）で表される部分構造は、２つの＊の位置で一方の環に、＊＊の位置で他方の環に結合しており、
前記多環芳香族化合物におけるアリール環およびヘテロアリール環からなる群より選択される少なくとも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－ＣＨ₂－は－Ｏ－で置換されていてもよく、
前記多環芳香族化合物における少なくとも１つの水素は、重水素、シアノまたはハロゲンで置換されていてもよい。 <1> A polycyclic aromatic compound having a partial structure represented by formula (1A) and at least one partial structure represented by formula (1B);

In formula (1A) and formula (1B),
ring A and ring B are each independently an optionally substituted aryl ring or an optionally substituted heteroaryl ring;
R ^XD is an optionally substituted aryl, an optionally substituted heteroaryl, an optionally substituted alkyl or an optionally substituted cycloalkyl, and the dashed line may be -X- or a single bond to be bonded to at least one of the A ring or the B ring;
The aryl or heteroaryl ring in at least one of ring A, ring B, or ^R is bonded to a partial structure represented by formula (1B),
The partial structure represented by formula (1B) is bonded to two adjacent atoms on the aryl ring or heteroaryl ring at the two * positions, respectively;
each C ring is independently an optionally substituted aryl ring or an optionally substituted heteroaryl ring;
R ^XE is an optionally substituted aryl, an optionally substituted heteroaryl, an optionally substituted alkyl or an optionally substituted cycloalkyl, and the dashed line may be -X- or a single bond to be bonded to the C ring, or the dashed line may be -X- or a single bond to be bonded to the ring to which the partial structure represented by formula (1B) is bonded at the (*) position;
Each Y is independently B, P, P=O or P=S;
X is each independently >C(-R) ₂ , >N-R, >O, >Si(-R) ₂ or >S, 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 and >Si(-R) ₂ are each independently hydrogen, an optionally substituted aryl, an optionally substituted alkyl or an optionally substituted cycloalkyl, and may be bonded to each other by a linking group, and at least one of R of the >N-R, the >C(-R) ₂ and the >Si(-R) ₂ may be bonded to at least one of ring A, ring B, ring C, R ^XD or R ^XE by a linking group or a single bond;
at least one of X's is >N-R, and R in at least one of X's that is >N-R is bonded to one of the A ring, B ring, C ring, R ^XD , or R ^XE to form a partial structure represented by formula (A10), in which R ^A1 to R ^A4 are each independently hydrogen, optionally substituted alkyl, or optionally substituted cycloalkyl, any two to four of R ^A1 to R ^A4 may be bonded to each other via a linking group or a single bond, and the partial structure represented by formula (A10) is bonded to one ring at the two * positions and to the other ring at the ** position,
At least one selected from the group consisting of an aryl ring and a heteroaryl ring in the polycyclic aromatic compound 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-;
At least one hydrogen in the polycyclic aromatic compound may be substituted with deuterium, cyano or halogen.

<2> The polycyclic aromatic compound according to <1>, wherein R ^XD is an optionally substituted aryl or an optionally substituted heteroaryl, the dashed line being -X- and bonded to ring A, and R ^XE is an optionally substituted aryl or an optionally substituted heteroaryl, the dashed line being -X- and bonded to ring C.
<3> The polycyclic aromatic compound according to <1> or <2>, in which R ^A1 and R ^A4 are bonded to each other, and R ^A2 and R ^A3 are each independently hydrogen or an optionally substituted alkyl.
<4> The polycyclic aromatic compound according to <1> or <2>, in which R ^A1 and R ^A4 are bonded to each other to form --(CH ₂ ) ₄ --, and R ^A2 and R ^A3 are both methyl.
<5> When ring A, ring B and ring C are substituted aryl rings or substituted heteroaryl rings, and when R and ^R are substituted ^aryl or substituted heteroaryl, each of the substituents is selected from the group consisting of 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, substituted silyl and -L-Ak,
L is >N-R, >O or >S, and R of the >N-R is an optionally substituted aryl, an optionally substituted heteroaryl, an optionally substituted alkyl or an optionally substituted cycloalkyl, and R of the >N-R may be bonded to Ak via a linking group or a single bond;
Ak is hydrogen, optionally substituted alkyl or optionally substituted cycloalkyl, in which at least one hydrogen in the alkyl and cycloalkyl is optionally substituted, and at least one -CH ₂ - in the alkyl and cycloalkyl is optionally substituted with -O- or -S-;
The polycyclic aromatic compound according to any one of <1> to <4>, wherein ring A, ring B, ^{ring C} , R and R are each bonded to any of X and Y in a 5-membered or 6-membered ring.

式（３－１－１）、式（３－１－２）、式（３－２－１）中、
Ｘ¹は、それぞれ独立して、＞Ｃ（－Ｒ）2、＞Ｎ－Ｒ、＞Ｏ、＞Ｓｉ（－Ｒ）₂または＞Ｓであり、前記＞Ｎ－ＲのＲは、炭素数１～６のアルキルもしくは炭素数３～１４のシクロアルキルで置換されていてもよい炭素数６～１２のアリール、炭素数１～６のアルキルもしくは炭素数３～１４のシクロアルキルで置換されていてもよい炭素数２～１５のヘテロアリール、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、前記＞Ｃ（－Ｒ）₂および＞Ｓｉ（－Ｒ）₂のＲは、それぞれ独立して、水素、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、
Ｙは、それぞれ独立して、Ｂ、Ｐ、Ｐ＝ＯまたはＰ＝Ｓであり、
Ｚは、それぞれ独立して、－Ｃ（－Ｒ^Z）＝または－Ｎ＝であり、隣り合う２つのＺは、－Ｃ（－Ｒ^Z）₂－、－Ｓｉ（－Ｒ^Z）₂－、－Ｎ（－Ｒ^Z）－、－Ｏ－、または－Ｓ－に置き換えられてもよく、
Ｒ^Z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、置換シリルまたは－Ｌ－Ａｋ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、また、Ｒ^Zのうちの隣接する基同士が結合してａ環、ｃ環、ｄ環またはｅ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、置換シリルまたは－Ｌ－Ａｋ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、
Ｌは＞Ｎ－Ｒ、＞Ｏまたは＞Ｓ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＞Ｎ－ＲのＲは連結基または単結合によりＡｋと結合していてもよく、
Ａｋは水素、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、当該アルキルおよびシクロアルキル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、当該アルキルおよびシクロアルキルにおける少なくとも１つの－ＣＨ₂－は－Ｏ－および－Ｓ－で置換されていてもよく、
式（３－１－１）、式（３－１－２）、式（３－２－１）で表される化合物における少なくとも１つの水素は、重水素、シアノまたはハロゲンで置換されていてもよい。 <6> The polycyclic aromatic compound according to <1>, represented by any one of the following formulas (3-1-1), (3-1-2), and (3-2-1):

In formula (3-1-1), formula (3-1-2), formula (3-2-1),
^X1 's are each independently >C(-R)2, >N-R, >O, >Si(-R) ₂ or >S, R of the >N-R is an aryl having 6 to 12 carbon atoms which may be substituted with an alkyl having 1 to 6 carbon atoms or a cycloalkyl having 3 to 14 carbon atoms, a heteroaryl having 2 to 15 carbon atoms which may be substituted with an alkyl having 1 to 6 carbon atoms or a cycloalkyl having 3 to 14 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 and >Si(-R) ₂ are each independently 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,
Each Y is independently B, P, P=O or P=S;
Z's are each independently -C(-R ^Z )= or -N=, and two adjacent Z's may be replaced by -C(-R ^Z ) ₂ -, -Si(-R ^Z ) ₂ -, -N(-R ^Z )-, -O-, or -S-;
R ^Z 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, substituted silyl, or -L-Ak, in which at least one hydrogen may be substituted with aryl, heteroaryl, alkyl, or cycloalkyl, or adjacent groups among R ^Z may be bonded together to form an aryl ring or heteroaryl ring together with the a ring, the c ring, the d ring, or the e ring, and at least one hydrogen in the formed ring may be substituted with 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, or -L-Ak, in which at least one hydrogen may be substituted with aryl, heteroaryl, alkyl, or cycloalkyl,
L is >N-R, >O or >S, and R of the >N-R is an optionally substituted aryl, an optionally substituted heteroaryl, an optionally substituted alkyl or an optionally substituted cycloalkyl, and R of the >N-R may be bonded to Ak via a linking group or a single bond;
Ak is hydrogen, optionally substituted alkyl or optionally substituted cycloalkyl, in which at least one hydrogen in the alkyl and cycloalkyl is optionally substituted, and at least one -CH ₂ - in the alkyl and cycloalkyl is optionally substituted with -O- or -S-;
At least one hydrogen atom in the compounds represented by formula (3-1-1), formula (3-1-2) and formula (3-2-1) may be substituted with deuterium, cyano or halogen.

<7> Y is B,
The polycyclic aromatic compound according to <6>, wherein each Z is independently -C(-R ^Z )= or -N=, provided that Z at the o-position or p-position to Y is -C(-R ^Z )=.
<8> The polycyclic aromatic compound according to <7>, wherein each Z is —C(—R ^Z )═.
<9> A reactive compound in which the polycyclic aromatic compound according to any one of <1> to <8> is substituted with a reactive substituent.
<10> A polymer compound obtained by polymerizing the reactive compound according to <9> as a monomer, or a crosslinked polymer obtained by further crosslinking the polymer compound.

<11> A pendant polymer compound in which the reactive compound according to <9> is substituted on a main chain polymer, or a pendant polymer crosslinked product in which the pendant polymer compound is further crosslinked.
<12> A material for an organic device, comprising the polycyclic aromatic compound according to any one of <1> to <8>.
<13> A material for an organic device, comprising the reactive compound according to <9>.
<14> A material for an organic device, comprising the polymer compound or crosslinked polymer according to <10>.
<15> A material for an organic device, comprising the pendant type polymer compound or the pendant type crosslinked polymer according to <11>.
<16> The material for an organic device according to any one of <12> to <15>, wherein the material for an organic device 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.
<17> The material for an organic device according to <16>, wherein the material for an organic electroluminescent element is a material for a light-emitting layer.
<18> A composition comprising the polycyclic aromatic compound according to any one of <1> to <8> and an organic solvent.
<19> A composition comprising the reactive compound according to <9> and an organic solvent.
<20> A composition comprising a main chain polymer, the reactive compound according to <9>, and an organic solvent.

<21> A composition comprising the polymer compound or crosslinked polymer according to <10> and an organic solvent.
<22> A composition comprising the pendant type polymer compound or the pendant type crosslinked polymer according to <11> and an organic solvent.
<23> An organic electroluminescence device comprising a pair of electrodes consisting of an anode and a cathode, and an organic layer disposed between the pair of electrodes and containing the polycyclic aromatic compound according to any one of <1> to <8>, the reactive compound according to <9>, the polymer compound or crosslinked polymer according to <10>, or the pendant polymer compound or crosslinked polymer according to <11>.
<24> The organic electroluminescent device according to <23>, wherein the organic layer is a light-emitting layer.
<25> The organic electroluminescent device according to <24>, wherein the light-emitting layer contains a host and the polycyclic aromatic compound, the reactive compound, the polymer compound, the crosslinked polymer, the pendant polymer compound, or the pendant crosslinked polymer as a dopant.

<26> The organic electroluminescent device according to <25>, wherein the host is an anthracene-based compound, a fluorene-based compound or a dibenzochrysene-based compound.
<27> The organic electroluminescence device according to any one of <24> to <26>, further comprising 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 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, arylnitrile derivatives, triazine derivatives, benzimidazole derivatives, phenanthroline derivatives, and quinolinol-based metal complexes.
<28> The organic electroluminescent device according to <27>, wherein at least one of the electron transport layer and the electron injection layer further contains at least one selected from the group consisting of an alkali metal, an alkaline earth metal, a rare earth metal, an oxide of an alkali metal, a halide of an alkali metal, an oxide of an alkaline earth metal, a halide of an alkaline earth metal, an oxide of a rare earth metal, a halide of a rare earth metal, an organic complex of an alkali metal, an organic complex of an alkaline earth metal, and an organic complex of a rare earth metal.
<29> The organic electroluminescence device according to any one of <24> to <28>, wherein at least one of the hole injection layer, the hole transport layer, the light-emitting layer, the electron transport layer and the electron injection layer comprises a polymer compound obtained by polymerizing a low molecular compound capable of forming each layer as a monomer, or a crosslinked polymer obtained by further crosslinking the polymer compound, or a pendant-type polymer compound obtained by reacting a low molecular compound capable of forming each layer with a main-chain polymer, or a pendant-type crosslinked polymer obtained by further crosslinking the pendant-type polymer compound.
<30> A display device or a lighting device comprising the organic electroluminescent device according to any one of <23> to <29>.

The present invention provides a novel polycyclic aromatic compound. The polycyclic aromatic compound of the present invention is useful as a material for organic devices, particularly as a material for forming a light-emitting layer in an organic electroluminescent device.

FIG. 1 is a schematic cross-sectional view illustrating an example of an organic EL element. 1A to 1C are diagrams illustrating a method for producing an organic EL element on a substrate having a bank by using an inkjet method.

The present invention will be described in detail below. The following explanation of the constituent elements may be based on representative embodiments or specific examples, but the present invention is not limited to such embodiments. In this specification, a numerical range expressed using "~" means a range that includes the numerical values written before and after "~" as the lower and upper limits. In this specification, "hydrogen" in the explanation of the structural formula means "hydrogen atom (H)".

In this specification, chemical structures and substituents are sometimes expressed by the number of carbon atoms, but when a chemical structure is substituted with a substituent or when a substituent is further substituted with a substituent, the number of carbon atoms means the number of carbon atoms in each of the chemical structures and the substituents, and does not mean the total number of carbon atoms in the chemical structure and the substituents, or the total number of carbon atoms in the substituents and the substituents. 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.

1. Polycyclic aromatic compound The polycyclic aromatic compound of the present invention is a polycyclic aromatic compound having a partial structure represented by the following formula (1A) and at least one partial structure represented by the following formula (1B).

In formula (1A) and formula (1B), "A", "B", and "C" are symbols indicating ring structures. Also, in formula (1A) and formula (1B), the dashed lines indicate that the rings or groups at both ends of the dashed lines may or may not be bonded to each other. In formula (1A) and formula (1B), * indicates a position, and in formula (1B), the (*) at one end of the dashed line indicates that that position may or may not be present.

The polycyclic aromatic compound of the present invention has a structure in which at least one of Xs connecting ring structures to each other is >N-R, where R is an optionally substituted alkyl or an optionally substituted cycloalkyl, and is linked to an aryl ring or heteroaryl ring in at least one of ring A, ring ^B , ring C, R, or ^R via a linking group or a single bond.
Specifically, the polycyclic aromatic compound of the present invention has the following partial structure (A10) due to the above-mentioned linkage.

In formula (A10), R ^A1 to R ^A4 are each independently hydrogen, optionally substituted alkyl or optionally substituted cycloalkyl, and any two to four of R ^A1 to R ^A4 may be bonded to each other by a linking group or a single bond, and are bonded to one of the two rings to which X is bonded at the two * positions, and to the other ring at the ** position. That is, N in formula (A10) is N of >N-R when X is >N-R. The atoms on the rings bonded at the two * positions may be adjacent atoms (preferably carbon atoms).
Although the partial structure represented by formula (A10) contains an N-C bond with a weak bond dissociation energy (BDE), the presence of another bond forming a ring promotes a reverse reaction (recombination reaction) even when the N-C bond is broken, so that the polycyclic aromatic compound of the present invention has a more stable structure. Therefore, an organic EL device manufactured using the polycyclic aromatic compound of the present invention is expected to have a longer device life.
The number of partial structures represented by formula (A10) formed by the above-mentioned linkage contained in the polycyclic aromatic compound of the present invention is 1 to "the number of X", and is preferably 1 or 2.

In formula (A10), R ^A1 to R ^A4 are hydrogen, optionally substituted alkyl or optionally substituted cycloalkyl, and any two to four of R ^A1 to R ^A4 may be linked to each other via a linking group.
Of R ^A1 to R ^A4 , any two (R ^A1 and R ^A4 , R ^A1 and R ^A4 and R ^A1 and R ^A4 , R ^A1 and R ^A2 , R ^A3 and R ^A4 , R ^A1 and R ^A4 and R ^A1 and R ^A4 ) are preferably bonded to each other by a linking group or a single bond, and it is more preferable that R ^A1 and R ^A4 are bonded to each other by a linking group or a single bond. An example of the divalent group formed by bonding to each other is alkylene. At least one hydrogen atom in the alkylene may be substituted with an alkyl or cycloalkyl, and at least one (preferably one) -CH ₂ - in the alkane may be substituted with -O- and -S-. As the linking group, a straight chain alkylene having 2 to 5 carbon atoms is preferable, a straight chain alkylene having 3 or 4 carbon atoms is more preferable, and a straight chain alkylene having 4 carbon atoms (-(CH ₂ ) ₄ -) is even more preferable. It is particularly preferred that the linear alkylene having 4 carbon atoms (--(CH ₂ ) ₄ --) is unsubstituted.

The remaining R ^A1 to R ^A4 that are not involved in the linking through the linking group are each preferably independently hydrogen or an alkyl which may be substituted, more preferably an alkyl having 1 to 6 carbon atoms which may be substituted, further preferably an unsubstituted alkyl having 1 to 6 carbon atoms, and most preferably methyl.
That is, the partial structure represented by formula (A10) is preferably a structure represented by the following formula (A11).

式（Ａ１１）中、Ｍｅはメチルであり、２つの＊の位置でＸが結合する２つの環の一方の環に、＊＊の位置で他方の環に結合している。

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

In formula (1A) and formula (1B), ring A, ring B and ring C each independently represent an optionally substituted aryl ring or an optionally substituted heteroaryl ring.
In formula (1A), R ^XD is an optionally substituted aryl, an optionally substituted heteroaryl, an optionally substituted alkyl, or an optionally substituted cycloalkyl. R ^XD may be bonded to at least one of ring A or ring B with a broken line being -X- or a single bond. R ^XD is preferably an optionally substituted aryl or an optionally substituted heteroaryl. Also, R ^XD is preferably bonded to ring A with a broken line being -X-. In formula (1B), R ^XE are each independently an optionally substituted aryl, an optionally substituted heteroaryl, an optionally substituted alkyl, or an optionally substituted cycloalkyl. R ^XE may be bonded to ring C with a broken line being -X- or a single bond, or may be bonded to the ring to which the partial structure represented by formula (1B) is bonded at the (*) position with a broken line being -X- or a single bond. R ^XE is preferably an optionally substituted aryl or an optionally substituted heteroaryl. Also, R ^XE is preferably bonded to ring C with a broken line being -X-.
That is, formula (1A) is preferably the following formula (2A), and formula (1B) is preferably the following formula (2B).

In formula (2A), an aryl ring or a heteroaryl ring in at least one of ring A, ring B, or ring D is bonded to a partial structure represented by formula (2B),
The partial structure represented by formula (2B) is bonded to two adjacent atoms on the aryl or heteroaryl ring at the two * positions, respectively.
In formula (2A), the same symbols as those in formula (1A) have the same meanings as those in formula (1A). "D" is a symbol indicating a ring structure, and is one embodiment of R ^XD in formula (1A). In formula (2B), the same symbols as those in formula (1B) have the same meanings as those in formula (1B). "E" is a symbol indicating a ring structure, and is one embodiment of R ^XE in formula (1B).

It is ^preferable that ring A, ring B, ring C, ^R and R in formula (1A) and formula (1B) (ring A, ring B, ring C, ring D and ring E in formula (2A) and formula (2B)) are all bonded to any of X and Y in a 5-membered or 6-membered ring. Here, "bonded to any of X and Y in a 5-membered or 6-membered ring" means that a ring is formed only with this 5-membered or 6-membered ring, or another ring is further condensed to include this 5-membered or 6-membered ring to form an aryl or heteroaryl ring in ring A, ring B, ring C, ^R or ^R , and that a ring-constituting atom on the 5-membered or 6-membered ring is bonded to any of X and Y.

The A ring, B ring, and C ring in formula (1A) and formula (1B), and the A ring, B ring, C ring, D ring, and E ring in formula (2A) and formula (2B) are each independently an optionally substituted aryl ring or an optionally substituted heteroaryl ring.

Examples of the "aryl ring" in ring A, ring B, ring C, ^R and R in ^formula (1A) and formula (1B), and ring A, ring B, ring C, ring D and ring E in formula (2A) and formula (2B) include an aryl ring having 6 to 30 carbon atoms, preferably an aryl ring having 6 to 16 carbon atoms, more preferably an aryl ring having 6 to 12 carbon atoms, and particularly preferably an aryl ring having 6 to 10 carbon atoms.

Specific examples of "aryl rings" include a monocyclic benzene ring, a bicyclic bicyclic bicyclic naphthalene ring and an indene ring, a tricyclic terphenyl ring (m-terphenyl, o-terphenyl, p-terphenyl), a fused tricyclic acenaphthylene ring, a fluorene ring, a phenalene ring, a phenanthrene ring, and an anthracene ring, a fused tetracyclic tricyclic triphenylene ring, a pyrene ring, a naphthacene ring, and a chrysene ring, and a fused pentacyclic perylene ring and a pentacene ring. In addition, the fluorene ring, benzofluorene ring, and indene ring each include a structure in which a fluorene ring, a benzofluorene ring, and a cyclopentane ring are spiro-bonded. In addition, the fluorene ring, benzofluorene ring, and indene ring also include rings in which two of the two hydrogen atoms of the methylene are replaced by alkyl such as methyl as the first substituent described below, resulting in a dimethylfluorene ring, dimethylbenzofluorene ring, and dimethylindene ring, etc.

Examples of the "heteroaryl ring" in ring A, ring B, ring C, ^R and R in ^formula (1A) and formula (1B), and ring A, ring B, ring C, ring D and ring E in formula (2A) and formula (2B) include a heteroaryl ring having 2 to 30 carbon atoms, preferably a heteroaryl ring having 2 to 25 carbon atoms, more preferably a heteroaryl ring having 2 to 20 carbon atoms, still more preferably a heteroaryl ring having 2 to 15 carbon atoms, and particularly preferably a heteroaryl ring having 2 to 10 carbon atoms. In addition, examples of the "heteroaryl ring" include heterocycles containing, as ring-constituting atoms other than carbon, 1 to 5 heteroatoms selected from oxygen, sulfur and nitrogen.

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 phthalazine ring, a naphthyl ring, a Examples of the ring include an aryl ring, a purine ring, a pteridine ring, a carbazole 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 thiophene ring, a benzothiophene ring, a dibenzothiophene ring, a furazan ring, a thianthrene ring, an indolocarbazole ring, a benzoindolocarbazole ring, a benzobenzoindolocarbazole ring, a naphthobenzofuran ring, a dioxin ring, a dihydroacridine ring, a xanthene ring, a thioxanthene ring, a dibenzodioxin ring, etc. In addition, it is also preferable that two of the two hydrogen atoms of the methylene are substituted with an alkyl such as methyl as the first substituent described later to form a dimethyldihydroacridine ring, a dimethylxanthene ring, a dimethylthioxanthene ring, etc. In addition, bicyclic rings such as bipyridine ring, phenylpyridine ring, and pyridylphenyl ring, and tricyclic rings such as terpyridyl ring, bispyridylphenyl ring, and pyridylbiphenyl ring are also included as "heteroaryl rings." In addition, "heteroaryl ring" also includes a pyran ring.

When at least one hydrogen atom in the above aryl ring or heteroaryl ring is replaced by 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 having an aryl and a heteroaryl), a substituted or unsubstituted diarylboryl (the 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, a substituted silyl, or -L-Ak. When these groups have a substituent, examples of the substituent include an aryl, a heteroaryl, an alkyl or cycloalkyl, or a diarylamino.

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", a substituted "silyl", or -L-Ak. Examples of the first substituent, 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 the monovalent groups of the above-mentioned "aryl ring" or "heteroaryl ring".

Specific examples of "aryl" include aryls having 6 to 30 carbon atoms, preferably aryls having 6 to 24 carbon atoms, more preferably aryls having 6 to 20 carbon atoms, even more preferably aryls having 6 to 16 carbon atoms, particularly preferably aryls having 6 to 12 carbon atoms, and most preferably aryls having 6 to 10 carbon atoms.

Specific examples of aryl include monocyclic aryl phenyl, bicyclic aryl (2-, 3-, 4-) biphenylyl, condensed bicyclic aryl (1-, 2-) naphthyl, (2-, 3-, 4-, 5-, 6-, 7-) indenyl, 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, aryl-4-yl), fused tricyclic aryls such as acenaphthylene-(1-,3-,4-,5-)yl, fluoren-(1-,2-,3-,4-,9-)yl, phenalen-(1-,2-)yl, (1-,2-,3-,4-,9-)phenanthryl, tetracyclic aryls such as quaterphenylyl (5'-phenyl-m-terphenyl-2-yl, 5'-phenyl-m-terphenyl -3-yl, 5'-phenyl-m-terphenyl-4-yl, m-quaterphenylyl), fused tetracyclic aryls such as triphenylene-(1-,2-)yl, pyrene-(1-,2-,4-)yl, naphthacene-(1-,2-,5-)yl, and fused pentacyclic aryls such as perylene-(1-,2-,3-)yl, pentacene-(1-,2-,5-,6-)yl.

Examples of "heteroaryl" include heteroaryls having 2 to 30 carbon atoms, preferably heteroaryls having 2 to 25 carbon atoms, more preferably heteroaryls having 2 to 20 carbon atoms, even more preferably heteroaryls having 2 to 15 carbon atoms, and particularly preferably heteroaryls having 2 to 10 carbon atoms. Examples of heteroaryls 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, dibenzofuranyl, benzo[b]thienyl, dibenzothienyl, indoaryl, and aryl. These include 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 "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 8 carbon atoms (branched alkyl having 3 to 8 carbon atoms) is even more preferred, an alkyl having 1 to 6 carbon atoms (branched alkyl having 3 to 6 carbon atoms) is particularly preferred, and an alkyl having 1 to 5 carbon atoms (branched alkyl having 3 to 5 carbon atoms) is most preferred.

Specific alkyl groups 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, 4-methyl-2-pentyl, 3,3-dimethylbutyl, 2-ethylbutyl, n-heptyl, 1-methylhexyl, n-octyl, and t-octyl (1,1,3,3-tetramethylbutyl). , 1-methylheptyl, 2-ethylhexyl, 2-propylpentyl, n-nonyl, 2,2-dimethylheptyl, 2,6-dimethyl-4-heptyl, 3,5,5-trimethylhexyl, n-decyl, n-undecyl, 1-methyldecyl, n-dodecyl, n-tridecyl, 1-hexylheptyl, n-tetradecyl, n-pentadecyl, n-hexadecyl, n-heptadecyl, n-octadecyl, n-eicosyl, etc.

Other examples include 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.

As a substituent containing the above "alkyl", a tertiary alkyl represented by the following formula (tR) is one of the particularly preferred substituents when at least one hydrogen atom in the above aryl ring or heteroaryl ring is substituted with a substituent. This is because such a bulky substituent increases the intermolecular distance, improving the luminescence quantum yield (PLQY). In addition, a substituent in which a tertiary alkyl represented by the formula (tR) is substituted with another substituent as a second substituent is also preferred. Specifically, a diarylamino substituted with a tertiary alkyl represented by (tR), a carbazolyl (preferably N-carbazolyl) substituted with a tertiary alkyl represented by (tR), or a benzocarbazolyl (preferably N-benzocarbazolyl) substituted with a tertiary alkyl represented by (tR) can be mentioned. For "diarylamino", the group described below as the "first substituent" can be mentioned. Examples of the substitution of the group of formula (tR) on diarylamino, carbazolyl, and benzocarbazolyl include those in which some or all of the hydrogen atoms on the aryl ring or benzene ring in these groups are substituted with the group of formula (tR).

In formula (tR), R ^a , R ^b , and R ^c each independently represent an alkyl group having 1 to 24 carbon atoms, any —CH ₂ — in the alkyl group may be replaced by —O—, and the group represented by formula (tR) replaces at least one hydrogen atom in a compound having a partial structure represented by formula (1A) and at least one partial structure represented by formula (1B) at *.

The "alkyl having 1 to 24 carbon atoms" of R ^a , R ^b and R ^c 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, alkyl having 1 to 18 carbon atoms (branched alkyl having 3 to 18 carbon atoms), alkyl having 1 to 12 carbon atoms (branched alkyl having 3 to 12 carbon atoms), alkyl having 1 to 6 carbon atoms (branched alkyl having 3 to 6 carbon atoms), and alkyl having 1 to 4 carbon atoms (branched alkyl having 3 to 4 carbon atoms).

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

Specific examples of alkyl for R ^a , R ^b , and R ^c include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, s-butyl, t-butyl, n-pentyl, isopentyl, neopentyl, t-pentyl, n-hexyl, 1-methylpentyl, 4-methyl-2-pentyl, 3,3-dimethylbutyl, 2-ethylbutyl, n-heptyl, 1-methylhexyl, n-octyl, t-octyl, 1-methylheptyl, Examples include 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 group represented by formula (tR) include t-butyl, t-amyl, 1-ethyl-1-methylpropyl, 1,1-diethylpropyl, 1,1-dimethylbutyl, 1-ethyl-1-methylbutyl, 1,1,3,3-tetramethylbutyl, 1,1,4-trimethylpentyl, 1,1,2-trimethylpropyl, 1,1-dimethyloctyl, 1,1-dimethylpentyl, 1,1-dimethylheptyl, 1,1,5-trimethylhexyl, 1-ethyl- Examples include 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. Of these, t-butyl and t-amyl are preferred.

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 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 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, and an alkoxy having 1 to 5 carbon atoms (branched alkoxy having 3 to 5 carbon atoms) is particularly preferred.

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

The "substituted silyl" as the first substituent is, for example, a silyl substituted with three substituents selected from the group consisting of alkyl, cycloalkyl, and aryl. Examples include trialkylsilyl, tricycloalkylsilyl, dialkylcycloalkylsilyl, alkyldicycloalkylsilyl, triarylsilyl, dialkylarylsilyl, and alkyldiarylsilyl.

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 5 carbon atoms, and specific examples include methyl, ethyl, propyl, i-propyl, butyl, sec-butyl, t-butyl, and t-amyl.

Specific examples of trialkylsilyl include trimethylsilyl, triethylsilyl, tripropylsilyl, tri-i-propylsilyl, tributylsilyl, trisec-butylsilyl, tri-t-butylsilyl, tri-t-amylsilyl, ethyldimethylsilyl, propyldimethylsilyl, i-propyldimethylsilyl, butyldimethylsilyl, sec-butyldimethylsilyl, t-butyldimethylsilyl, t-amyldimethylsilyl, methyldiethylsilyl, propyldiethylsilyl, i-propyldiethylsilyl, and butyl. Examples include ethyl diethylsilyl, sec-butyl diethylsilyl, t-butyl diethylsilyl, t-amyl diethylsilyl, methyl dipropylsilyl, ethyl dipropylsilyl, butyl dipropylsilyl, sec-butyl dipropylsilyl, t-butyl dipropylsilyl, t-amyl dipropylsilyl, methyl di-i-propylsilyl, ethyl di-i-propylsilyl, butyl di-i-propylsilyl, sec-butyl di-i-propylsilyl, t-butyl di-i-propylsilyl, and t-amyl di-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.

Specific examples of dialkylarylsilyl substituted with two alkyls and one aryl, alkyldiarylsilyl substituted with one alkyl and two aryls, and triarylsilyl substituted with three aryls include silyl substituted with a group selected from the specific alkyls and aryls listed above. A specific example of triarylsilyl is triphenylsilyl.

As for the "aryl" in the "diarylboryl" of the first substituent, the above description 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 (above, the first substituent), and the first substituent may be further substituted with aryl, heteroaryl, alkyl, or cycloalkyl (above, the second substituent), and as specific examples of these groups, the above description of the aryl, heteroaryl, diarylamino, alkyl, cycloalkyl, alkoxy, or aryloxy as the first substituent can be cited.

In the first substituent -L-Ak, L is >N-R, >O or >S, and R in >N-R is an optionally substituted aryl, an optionally substituted heteroaryl, an optionally substituted alkyl or an optionally substituted cycloalkyl. In addition, R in >N-R may be bonded to Ak via a linking group or a single bond.

Ak is hydrogen, optionally substituted alkyl or optionally substituted cycloalkyl, in which at least one hydrogen in the alkyl and cycloalkyl may be substituted, and at least one -CH ₂ - in the alkyl and cycloalkyl may be substituted with -O- and -S-.

It is preferred that L is >N-R.
When L is >N-R, R is preferably aryl which may be substituted with alkyl or cycloalkyl, heteroaryl which may be substituted with alkyl or cycloalkyl, alkyl or cycloalkyl, more preferably aryl which may be substituted with alkyl, heteroaryl which may be substituted with alkyl, alkyl or cycloalkyl, further preferably aryl which may be substituted with alkyl, and particularly preferably phenyl which may be substituted with methyl.

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

When L is >N-R, R may be bonded to Ak via a linking group or a single bond. In this case, examples of the linking group include >O, >S, and >Si(-R) ₂ . R in >Si(-R) ₂ is 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. Examples of structures in which R in >N-R is bonded to Ak via a linking group or a single bond include the following.

In the above formulas, Me is methyl and is bonded to an atom constituting a ring of an aryl ring or heteroaryl ring in ring A, ring B, ring C, R ^XD or R ^XE at the position *.

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 monovalent group of the "aryl ring" or "heteroaryl ring", and the explanation of the "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 listed above), an alkyl such as methyl and t-butyl (specific examples are the groups listed above), or a cycloalkyl such as cyclohexyl (specific examples are the groups listed above). As an example, when the second substituent is carbazolyl, a carbazolyl 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.

The emission wavelength can be adjusted by the steric hindrance, electron donating property and electron withdrawing property of the structure of the first substituent. A group represented by the following structural formula is preferred, and more preferred are methyl, t-butyl, t-amyl, t-octyl, neopentyl, adamantyl, phenyl, o-tolyl, p-tolyl, 2,4-xylyl, 2,5-xylyl, 2,6-xylyl, 2,4,6-mesityl, diphenylamino, di-p-tolylamino, bis(p-(t-butyl)phenyl)amino, carbazolyl (particularly N-carbazolyl), 3,6-dimethylcarbazolyl, and 1,2-dimethylcarbazolyl. and more preferably, methyl, t-butyl, t-amyl, t-octyl, neopentyl, adamantyl, phenyl, o-tolyl, 2,6-xylyl, 2,4,6-mesityl, diphenylamino, di-p-tolylamino, bis(p-(t-butyl)phenyl)amino, carbazolyl, 3,6-dimethylcarbazolyl, and 3,6-di-t-butylcarbazolyl. From the viewpoint of ease of synthesis, a larger steric hindrance is preferred for selective synthesis, and specifically, t-butyl, t-amyl, t-octyl, adamantyl, o-tolyl, p-tolyl, 2,4-xylyl, 2,5-xylyl, 2,6-xylyl, 2,4,6-mesityl, di-p-tolylamino, bis(p-(t-butyl)phenyl)amino, 3,6-dimethylcarbazolyl, and 3,6-di-t-butylcarbazolyl are preferred.

In the following structural formula, "Me" is methyl, "tBu" is t-butyl, "tAm" is t-amyl, "tOct" is t-octyl, and * indicates a bonding position.

In formula (1A) and formula (1B), Y is each independently B, P, P=O or P=S, with B or P=O being preferred, and B being more preferred. This explanation also applies to Y in formula (2A) and formula (2B).

X in formula (1A) and formula (1B) are each independently >C(-R)2, >N-R, >O, >Si(-R) ₂ or >S, 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 and >Si(-R) ₂ are each independently hydrogen, an optionally substituted aryl, an optionally substituted alkyl or an optionally substituted cycloalkyl, and may be bonded to each other by a linking group, and at least one of R of the >N-R, the >C(-R) ₂ and the >Si(-R) ₂ may be bonded to at least one of the A ring, the B ring, the C ring, R ^XD or R ^XE by a linking group or a single bond. As described above, at least one of X is >N-R, where R is an optionally substituted alkyl or an optionally substituted cycloalkyl, and is linked to an aryl or heteroaryl ring in at least one of ring A, ring B, ring C, R ^XD , or R ^XE via a linking group or a single bond through R. The explanation of X in formula (1A) and formula (1B) and the explanation of the preferred ranges and the like below also apply to X in formula (2A) and formula (2B). Note that "at least one of ring A, ring B, ring C, R ^XD , or R ^XE " is to be read as "at least one selected from the group consisting of ring A, ring B, ring C, ring D, or ring E" in formula (2A) and formula (2B).

R of >Si(-R) ₂ as X in formula (1A) and formula (1B) is an aryl, heteroaryl, alkyl or cycloalkyl which may be substituted with the second substituent described above. Examples of the aryl, heteroaryl, alkyl or cycloalkyl include the groups described above. 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 5 carbon atoms (e.g., methyl, ethyl, etc.) or cycloalkyl having 5 to 10 carbon atoms (preferably cyclohexyl or adamantyl) are preferred. This explanation also applies to R of >Si(-R) ₂ as X in formula (2A) and formula (2B).

R in >C(-R) ₂ as X in formula (1A) and formula (1B) is hydrogen, aryl, heteroaryl, alkyl or cycloalkyl which may be substituted with the second substituent described above. Examples of the aryl, heteroaryl, alkyl or cycloalkyl include the groups described above. 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 5 carbon atoms (e.g., methyl, ethyl, etc.) or cycloalkyl having 5 to 10 carbon atoms (preferably cyclohexyl or adamantyl) are preferred. This explanation also applies to R in >C(-R) ₂ as X in formula (2A) and formula (2B).

In formula (1A) and formula (1B), at least one X is the above-mentioned >N-R, and the other Xs are each preferably independently >O or >N-R, more preferably at least one of them is >N-R, and even more preferably all of them are >N-R.

For the aryl, heteroaryl, alkyl, and cycloalkyl in R of >N-R which is X, the explanation of them as the first substituent above can be referred to. R of >N-R in X is preferably an aryl which may be substituted, a heteroaryl which may be substituted, or a cycloalkyl which may be substituted, and more preferably an aryl which may be substituted. Here, as the aryl, phenyl, biphenylyl (particularly 2-biphenylyl), and terphenylyl (particularly terphenyl-2'-yl) are preferred, and phenyl and biphenylyl are more preferred. When the aryl is substituted, the substituent is preferably methyl or a tertiary alkyl represented by the above formula (tR). The number of substituents in the aryl is preferably 0 to 3, and more preferably 1 to 2.

As the R in >N-R where X is, unsubstituted phenyl, phenyl with methyl bonded to the ortho or para position, and phenyl with methyl bonded to one or two ortho positions are particularly preferred.

R in at least one of >N-R, >Si(-R) ₂ and >C(-R) ₂ as X may be bonded to at least one ring in A ring, B ring, C ring, R ^XD or R ^XE by a linking group or a single bond. As the linking group, -O-, -S- or -C(-R) ₂ - is preferable. R in the above-mentioned "-C(-R) ₂ -" is hydrogen, alkyl or cycloalkyl. Specific examples of such structures include the structure represented by the above formula (A10). In addition, more generally, compounds having a ring structure in which X is incorporated into fused ring B' represented by the following formula (1-3-1) and compounds having a ring structure in which X is incorporated into fused ring A' represented by the following formula (1-3-2) are included. The fused ring B' (or fused ring A') formed is, for example, a carbazole ring, a phenoxazine ring, a phenothiazine ring or an acridine ring.

Examples of the linking group when X in formula (1A) and formula (1B) is bonded to at least one ring in ring A, ring B, ring C, R ^XD or R ^XE include -O-, -S-, -C(-R) ₂ - or a single bond, and among these, R in "-C(-R) ₂ -" is hydrogen, alkyl or cycloalkyl, and the alkyl or cycloalkyl includes the groups described above. In particular, alkyl having 1 to 5 carbon atoms (e.g., methyl, ethyl, etc.) or cycloalkyl having 5 to 10 carbon atoms (preferably cyclohexyl or adamantyl) is preferred. This explanation also applies to the linking group "-C(-R) ₂ -" when X in formula (2A) and formula (2B) is bonded to at least one ring in at least one ring in ring A, ring B, ring C, ring D or ring E.

At least one selected from the group consisting of aryl rings and heteroaryl rings in a compound consisting of a partial structure represented by formula (1A) and at least one partial structure represented by formula (1B) 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-. This explanation also applies to compounds in which formulas (1A) and (1B) are formulas (2A) and (2B), respectively.

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, a structure in which at least one hydrogen atom is substituted on the α-position carbon of the cycloalkane (the carbon atom adjacent to the carbon atom at the condensation site in a cycloalkyl fused to an aryl ring or heteroaryl ring) is preferred, a structure in which two hydrogen atoms are substituted on the α-position carbon is more preferred, and a structure in which a total of four hydrogen atoms are substituted on the two α-position carbons 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. In particular, a structure in which a partial structure represented by the following formula (B10) is bonded to adjacent carbon atoms in an aryl ring or heteroaryl ring is preferred.

式（Ｂ１０）中、Ｍｅはメチルを示し、＊は結合位置を示す。

In formula (B10), Me represents methyl, and * represents the bonding position.

The hydrogen atoms in the chemical structure of the polycyclic aromatic compound consisting of the partial structure represented by formula (1A) and at least one partial structure represented by formula (1B) may be substituted in whole or in part with deuterium, cyano, or halogen. For example, in the polycyclic aromatic compound consisting of the partial structure represented by formula (1A) and at least one partial structure represented by formula (1B), the hydrogen atoms in the aryl or heteroaryl rings in ring A, ring B, ring C, R ^XD , or R ^XE , the substituents on these rings, and R (= alkyl, cycloalkyl, aryl) when X is >N-R, >C(-R) ₂ , or >Si(-R) ₂ may be substituted with deuterium, cyano, or halogen, and among these, there are embodiments in which all or a part of the hydrogen atoms in the aryl or heteroaryl are substituted with deuterium, cyano, or halogen. The halogen atom is fluorine, chlorine, bromine, or iodine, preferably fluorine, chlorine, or bromine, more preferably fluorine or chlorine, and even more preferably fluorine. From the viewpoint of durability, it is also preferable that all or a part of the hydrogen atoms in the chemical structure of the polycyclic aromatic compound having the partial structure represented by formula (1A) and at least one partial structure represented by formula (1B) are deuterium atoms. This explanation also applies to compounds in which formula (1A) and formula (1B) are formula (2A) and formula (2B), respectively.

Examples of polycyclic aromatic compounds having a partial structure represented by formula (1A) and at least one partial structure represented by formula (1B) include polycyclic aromatic compounds represented by any of the following formulas (3-1) to (3-4).

In formulas (3-1) to (3-4), the same symbols as those in formulas (1A) and (1B) have the same meanings as those in formulas (1A) and (1B), and the preferred ranges are also the same. ^Note that ring A, ring B, ring C, ^R and R in formulas (1A) and (1B) are to be read as ring a, ring b, ring c, ring d and ring e, or ring a, ring b, ring c (ring c'), ring d and ring e (ring e'), respectively.
In formulas (3-1) to (3-4), Z is each independently -C(-R ^Z )= or -N=, and two adjacent Zs may be replaced by -C(-R ^Z ) ₂ -, -Si(-R ^Z ) ₂ -, -N(-R ^Z )-, -O-, or -S-. Examples of structures in which two adjacent Zs are replaced by -C(-R ^Z ) ₂ -, -Si(-R ^Z ) ₂ -, -N(-R ^Z )-, -O-, or -S- include a cyclopentadiene ring, a pyrrole ring, a furan ring, a thiophene ring, a thiazole ring, and an oxazole ring.

In formula (3-1) to formula (3-4), Z is each independently -C(-R ^Z )= or -N=, and it is preferable that two adjacent Zs are not replaced with -C(-R ^Z ) ₂ -, -Si(-R ^Z ) ₂ -, -N(-R ^Z )-, -O-, or -S-. In this case, Z at the o (ortho) position or p (para) position with respect to Y is preferably -C(-R ^Z )=. In addition, in a ring (monocyclic ring) containing Z which is -N=, it is preferable that one or two of the multiple Zs are -N=, and when two are -N=, it is preferable that the two -N=s are not adjacent to each other. When the 6-membered ring is a ring containing Z which is -N=, it is preferable that it is a pyridine ring, a pyrazine ring, a pyrimidine ring, a pyridazine ring, or a 1,2,3-triazine ring, and a pyridine ring, a pyrazine ring, or a pyrimidine ring is more preferable. The number of rings (monocyclic rings) containing Z where -N= is preferably 0 to 4, more preferably 0 to 3, further preferably 0 to 2, and particularly preferably 0 to 1.

Specifically, it is preferred that all Z's are -C(-R ^Z )=, that is, all rings are benzene rings which may have a substituent. In addition to all being -C(-R ^Z )= in formula (3-1) and formula (3-2), it is also preferred that at least one of Z's in ring b is -N= and the other Z's are each independently -C(-R ^Z )=.

R ^Z is 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, or substituted silyl, in which at least one hydrogen may be replaced by aryl, heteroaryl, alkyl, or cycloalkyl, and adjacent groups among R ^Z may be bonded to each other to form an aryl ring or a heteroaryl ring together with the a ring, the c ring, the d ring, and the e ring, or the a ring, the c ring, the d ring, the e ring, the c′ ring, and the e′ ring, and at least one hydrogen in the formed ring may be replaced by aryl, heteroaryl, diarylamino, diheteroarylamino, arylheteroarylamino, diarylboryl (two aryls may be bonded via a single bond or a linking group), alkyl, cycloalkyl, alkoxy, aryloxy, or substituted silyl, and at least one hydrogen in these may be replaced by aryl, heteroaryl, alkyl, or cycloalkyl.

For details and preferred ranges of R ^Z , the above descriptions of the first and second substituents can be referred to.

In formulas (3-1) to (3-4), when Z is -C(-R ^Z )=, R ^Z is preferably each independently hydrogen, an aryl having 6 to 30 carbon atoms, a heteroaryl having 2 to 30 carbon atoms, a diarylamino (wherein the aryl is an aryl having 6 to 12 carbon atoms), a 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, a triarylsilyl (wherein the aryl is an aryl having 6 to 12 carbon atoms), or a trialkylsilyl (wherein the alkyl is an alkyl having 1 to 6 carbon atoms), provided that adjacent R ^Z 's may be bonded to each other to form, together with ring a, ring b or ring c, an aryl ring having 9 to 16 carbon atoms or a heteroaryl ring having 6 to 15 carbon atoms, and at least one hydrogen atom in the formed ring may be substituted by an aryl having 6 to 10 carbon atoms, an alkyl having 1 to 12 carbon atoms, a cycloalkyl having 3 to 16 carbon atoms, a triarylsilyl (wherein the aryl is an aryl having 6 to 12 carbon atoms), or a trialkylsilyl (wherein the alkyl is an alkyl having 1 to 5 carbon atoms);
More preferably, each independently represents hydrogen, an aryl having 6 to 16 carbon atoms, a heteroaryl having 2 to 20 carbon atoms, a diarylamino (wherein the aryl has 6 to 10 carbon atoms), an alkyl having 1 to 12 carbon atoms, or a cycloalkyl having 3 to 16 carbon atoms;
More preferably, each independently represents hydrogen, an aryl having 6 to 16 carbon atoms, diarylamino (wherein the aryl has 6 to 10 carbon atoms), an alkyl having 1 to 12 carbon atoms, or a cycloalkyl having 3 to 16 carbon atoms.

In each of the rings a, b, c (ring c'), d and e (ring e') in the formulae (3-1) to (3-4), it is preferable that 0 to 2 R ^Zs are substituents other than hydrogen and the rest are hydrogen, and it is more preferable that 0 to 1 R Zs are substituents other than hydrogen and the rest are hydrogen.
In each of the rings a, b, c (ring c'), d and e (ring e') in the formulas (3-1) to (3-4), in the ring which is bonded to R of >N-R as X to form the structure represented by the above formula (A10), it is preferable that Z other than the bonding portion is C-H.

In each of formulas (3-1) to (3-4), R ^Zs bonded to adjacent C (carbon atoms) may be bonded to each other to form an aryl ring or a heteroaryl ring together with ring a, ring b, ring c (ring c'), ring d, or ring e (ring e').
Examples of compounds represented by formula (3-1) include a structure in which R ^Z are bonded together to form an aryl ring or heteroaryl ring together with ring a, as shown in the following formula (3-1-a), and a structure in which R ^Z are bonded together to form an aryl ring or heteroaryl ring together with ring d, and a structure in which R ^Z are bonded together to form an aryl ring or heteroaryl ring together with ring e, as shown in the following formula (3-1-b). Ring A', ring D', and ring E' in each formula correspond to ring a, ring d, and ring e in formula (3-1), respectively. In addition, the definitions of Z, a, b, c, d, e, Y, X, and Z in each formula are the same as those in formula (3-1).

In formula (3-1-a) and formula (3-1-b), when explained in formula (3-1), ring A', ring D' and E' respectively represent aryl or heteroaryl rings formed by bonding R ^Z's bonded to adjacent C's (carbon atoms) together with ring a, ring b and ring e (they may also be considered as condensed rings formed by condensing other ring structures to ring a, ring b and ring e). Although not shown in the formula, there are also compounds in which ring b and ring c are changed to ring B' and ring C', and compounds in which ring a, ring b, ring c (ring c'), ring d or ring e (ring e') are all changed to ring A', ring B', ring C', ring D' and ring E'.

For example, the fused ring A' (or B', C', D', or E' ring) formed by condensing a benzene ring, an indole ring, a pyrrole ring, a furan ring, a thiophene ring, a benzofuran ring, a benzothiophene ring, a cyclopentadiene ring, or an indene ring to the benzene ring a (or b, c (c'), d, or e (e') ring) is a naphthalene ring, a carbazole ring, an indole ring, a benzofuran ring, a benzothiophene ring, a dibenzofuran ring, a dibenzothiophene ring, an indene ring, or a fluorene ring, respectively.

Furthermore, for example, in the case of a ring a (or b ring, c ring (c′ ring), d ring, or e ring (e′ ring)), a cyclopentadiene ring, a pyrrole ring, a furan ring, or a thiophene ring, when R ^Z bonded to adjacent C are bonded to each other to form a ring to form a benzene ring, examples of the fused ring include an indene ring, an indole ring, a benzofuran ring, and a benzothiophene ring.

Preferred examples of polycyclic aromatic compounds represented by any of formulas (3-1) to (3-4) include polycyclic aromatic compounds represented by any of formulas (3-1-1), (3-1-2), and (3-2-1).

In formulae (3-1-1), (3-1-2), and (3-2-1), the same symbols as those in formulae (3-1) to (3-4) have the same meanings as those in formulae (3-1) to (3-4), respectively, and the preferred ranges are also the same.
In formula (3-1-1), formula (3-1-2), and formula (3-2-1), ^X1 's are each independently >C(-R)2, >N-R, >O, >Si(-R) ₂ , or >S, and R of the >N-R is an aryl having 6 to 12 carbon atoms which may be substituted with an alkyl having 1 to 6 carbon atoms or a cycloalkyl having 3 to 14 carbon atoms, a heteroaryl having 2 to 15 carbon atoms which may be substituted with an alkyl having 1 to 6 carbon atoms or a cycloalkyl having 3 to 14 carbon atoms, an alkyl having 1 to 6 carbon atoms, or a cycloalkyl having 3 to 14 carbon atoms, and R of the >C(-R) ₂ and >Si(-R) ₂ are each independently 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. As the preferred range of ^X1 , the preferred range of X in formula (1A) and formula (1B) can be referred to, but specifically, it is preferable that it is >N-R or >O, and in this case, R of >N-R is preferably an aryl having 6 to 12 carbon atoms which may be substituted with an alkyl having 1 to 6 carbon atoms or a heteroaryl having 2 to 15 carbon atoms which may be substituted with an alkyl having 1 to 6 carbon atoms, more preferably an aryl having 6 to 12 carbon atoms which may be substituted with an alkyl having 1 to 6 carbon atoms, and even more preferably phenyl which may be substituted with methyl or t-butyl.

Specific examples of polycyclic aromatic compounds consisting of a partial structure represented by formula (1A) and at least one partial structure represented by formula (1B) include polycyclic aromatic compounds represented by any of the following formulas:

The hydrogen bonded to the benzene ring in each of the above structural formulas may be replaced with methyl or t-butyl, and consecutive hydrogens may be replaced with the partial structure represented by the above formula (B10).

Specific examples of the polycyclic aromatic compounds of the present invention include compounds represented by the following structural formulas. In the structural formulas, "Me" represents methyl and "tBu" represents t-butyl.

The polycyclic aromatic compound consisting of a partial structure represented by formula (1A) and at least one partial structure represented by formula (1B) can be used as a material for organic devices, for example, a material for organic electroluminescent elements, a material for organic field effect transistors, or a material for organic thin-film solar cells, as a polymer compound obtained by polymerizing a reactive compound substituted with a reactive substituent as a monomer (the monomer for obtaining this polymer compound has a polymerizable substituent), or as a crosslinked polymer obtained by further crosslinking the polymer compound (the polymer compound for obtaining this crosslinked polymer has a crosslinkable substituent), or as a pendant polymer compound obtained by reacting a main chain polymer with the reactive compound (the reactive compound for obtaining this pendant polymer compound has a reactive substituent), or as a pendant polymer crosslinked polymer obtained by further crosslinking the pendant polymer compound (the pendant polymer compound for obtaining this pendant polymer crosslinked polymer has a crosslinkable substituent).

The reactive substituents mentioned above (including the polymerizable substituents, the crosslinkable substituents, and the reactive substituents for obtaining a pendant polymer, hereinafter also referred to simply as "reactive substituents") are not particularly limited as long as they are substituents capable of increasing the molecular weight of the polycyclic aromatic compound, substituents capable of further crosslinking the polymer compound thus obtained, and substituents capable of reacting as pendants with the main-chain polymer, but examples thereof include unsaturated alkenyl, alkynyl, and cycloalkyl (e.g., cyclobutenyl), groups in which at least one -CH ₂ - in a cycloalkyl is replaced with -O- (e.g., epoxy), and unsaturated condensed cycloalkanes (e.g., condensed cyclobutene), and substituents having the following structures are preferred: * in each structural formula indicates a bond position.

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

The uses of such polymer compounds, crosslinked polymers, pendant polymer compounds, and pendant polymer crosslinked polymers (hereinafter simply referred to as "polymer compounds and crosslinked polymers") will be described in detail below.

2. Method for Producing Polycyclic Aromatic Compounds Polycyclic aromatic compounds consisting of a partial structure represented by formula (1A) and at least one partial structure represented by formula (1B) are basically produced by first bonding ring A (ring a), ring B (ring b), ring C (ring c), R ^XD (ring D, ring d), and R ^XE (ring E, ring e) with a bonding group (group containing X) to produce an intermediate (first reaction), and then bonding ring A (ring a), ring B (ring b), ring C (ring c), R ^XD (ring D, ring d), and R ^XE (ring E, ring e) with a bonding group (group containing Y) to produce a final product (second reaction). In the first reaction, for example, if it is an etherification reaction, a general reaction such as a nucleophilic substitution reaction or an Ullmann reaction can be used, and if it is an amination reaction, a general reaction such as a Buchwald-Hartwig reaction can be used. In addition, in the second reaction, a tandem hetero Friedel-Crafts reaction (successive aromatic electrophilic substitution reactions, the same applies below) can be used. For these manufacturing methods, the methods described in prior art documents such as International Publication No. WO 2015/102118 can be referred to. A compound having a partial structure represented by formula (A10) can be manufactured by using a raw material having a partial structure represented by formula (A10) somewhere in the reaction process or adding a process of introducing a partial structure represented by formula (A10). The partial structure represented by formula (A10) can be synthesized by using Fischer's indole synthesis and addition reaction.

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.

3-1-1. Structure of Organic Electroluminescent Device The organic EL device 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".

3-1-2. Substrate in organic electroluminescence element The substrate 101 is a support for the organic EL element 100, and is usually made of quartz, glass, metal, plastic, etc. 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, etc. are used. Among them, a glass plate and a plate made of a transparent synthetic resin such as polyester, polymethacrylate, polycarbonate, polysulfone, etc. 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 is sufficient to 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.

The anode 102 plays a role of injecting holes into the light-emitting layer 105. When the hole injection layer 103 and/or the hole transport layer 104 are provided between the anode 102 and the light-emitting layer 105, the holes are injected into the light-emitting layer 105 through 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.

3-1-4. Hole injection layer and hole transport layer in organic electroluminescence element 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. To achieve this, it is preferable for the material to have a small ionization potential, a large hole mobility, excellent stability, and a low probability of generating 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, 4,4',4"-tris(3-methylphenyl(phenyl)amino)triphenylamine, N-([1,1'-biphenyl]-4-yl)-9,9-dimethyl-N-(4-(9-phenyl-9H-carbazol-3-yl)phenyl)-9H-fluoren-2-amine, N,N-bis(4-(dibenzo[b,d]furan-4-yl)phenyl)-[1,1':4',1"-terphenyl]- triphenylamine derivatives such as 4-amine, 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, polysilanes, etc. are preferred, but there is no particular limitation as long as the compound can form a thin film necessary for the production of 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 doping. 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. Pfeiffer, T. Fritz, K. Leo, Appl. Phys. Lett., 73(6), 729-731 (1998)"). These generate so-called holes by an electron transfer process in an electron-donating base material (hole transport material). The conductivity of the base material varies considerably depending on the number and mobility of the holes. Matrix materials with hole transport properties are known, for example, benzidine derivatives (such as TPD) or starburst amine derivatives (such as TDATA), or certain metal phthalocyanines (especially zinc phthalocyanine (ZnPc)) (JP 2005-167175 A).

The above-mentioned hole injection layer material and hole transport layer material can also be used as a hole layer material in the form of a polymer compound obtained by polymerizing a reactive compound substituted with a reactive substituent as a monomer, or a crosslinked polymer thereof, or a pendant polymer compound obtained by reacting a main chain polymer with the reactive compound, or a crosslinked pendant polymer thereof. In this case, the reactive substituent can be quoted from the description of the polycyclic aromatic compound having a partial structure represented by formula (1A) and at least one partial structure represented by formula (1B).
The applications of such polymer compounds and crosslinked polymers will be described in detail below.

3-1-5. Light-emitting layer in organic electroluminescent element The light-emitting layer 105 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 by the recombination of holes and electrons to emit light, and is preferably a compound that can form a stable thin film shape and shows strong light-emitting (fluorescence) efficiency in a solid state. The light-emitting layer may be a single layer or multiple layers, and is formed from materials for the light-emitting layer (host material, dopant material). The host material and the dopant material may each be one type or a combination of multiple types. For example, an emitting dopant and an assisting dopant may be used as the dopant material. The dopant material may be contained in the entire host material or may be contained partially in the host material. As a doping method, the light-emitting layer may be formed by co-evaporation with the host material, but it may also be mixed with the host material in advance and then evaporated at the same time. The light-emitting layer can also be formed by a wet film-forming method using a composition for forming a light-emitting layer prepared by dissolving materials in an organic solvent.

The polycyclic aromatic compound of the present invention can be preferably used as a material for forming the light-emitting layer of an organic electroluminescent device. The polycyclic aromatic compound of the present invention is more preferably used as an emitting dopant or an assisting dopant in the light-emitting layer, and is even more preferably used as an emitting dopant.

The light-emitting layer containing the polycyclic aromatic compound of the present invention may contain a host compound. Here, the host compound may be one type or two or more types.
The light-emitting layer may be a single layer or multiple layers. The host compound, the emitting dopant material, and the assisting dopant material may be contained in the same layer, or at least one component may be contained in each of the multiple layers. The host compound and the dopant material (emitting dopant or assisting dopant) contained in the light-emitting layer may each be one type or a combination of multiple types. The assisting dopant and the emitting dopant may be entirely or partially contained in the host compound as a matrix.

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 mass, more preferably 80 to 99.95% by mass, and even more preferably 90 to 99.9% by mass, 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 mass of the total light-emitting layer material, more preferably 0.05 to 20% by mass, and even more preferably 0.1 to 10% by mass. The above ranges are preferable in that, for example, concentration quenching can be prevented.

On the other hand, in an organic electroluminescent device using a TADF material as a dopant material, a low concentration of the dopant material is preferable in terms of preventing concentration quenching, but a high concentration of the dopant material is preferable in terms of the efficiency of the thermally activated delayed fluorescence mechanism. Furthermore, in an organic electroluminescent device using a TADF material as an assisting dopant, a low concentration of the emitting dopant is preferable compared to the amount of the assisting dopant in terms of the efficiency of the thermally activated delayed fluorescence mechanism of the assisting dopant.

When an assisting dopant material is used, the approximate amounts of the host material, emitting dopant, and assisting dopant used are 40 to 99.999% by mass, 59 to 1% by mass, and 20 to 0.001% by mass, respectively, of the total light-emitting layer material, preferably 60 to 99.99% by mass, 39 to 5% by mass, and 10 to 0.01% by mass, respectively, and more preferably 70 to 99.95% by mass, 29 to 10% by mass, and 5 to 0.05% by mass.

3-1-5-1. Host Compound Examples of host materials include condensed ring derivatives of anthracene and pyrene, which have long been known as light emitters, bisstyryl derivatives such as bisstyrylanthracene derivatives and distyrylbenzene derivatives, tetraphenylbutadiene derivatives, cyclopentadiene derivatives, fluorene derivatives, and benzofluorene derivatives.

From the viewpoint of promoting rather than inhibiting the generation of TADF in the light-emitting layer, the T1 energy of the host material is preferably higher than the T1 energy of the dopant or assisting dopant having the highest T1 energy in the light-emitting layer. Specifically, the T1 energy of the host is preferably 0.01 eV or more, more preferably 0.03 eV or more, and even more preferably 0.1 eV or more.
A compound having TADF activity may be used as the host material.

Examples of the host material include a compound represented by the following formula (H1), a compound represented by the following formula (H2), a compound represented by the following formula (H3), a compound including a structure represented by the following formula (H4), a compound represented by the following formula (H5), and a compound represented by the following formula (H6).

3-1-5-1-1. Compound represented by formula (H1)

In formula (H1), L ¹ is an arylene having 6 to 24 carbon atoms, preferably an arylene having 6 to 16 carbon atoms, more preferably an arylene having 6 to 12 carbon atoms, and particularly preferably an arylene having 6 to 10 carbon atoms. Specific examples of L 1 include divalent groups such as a benzene ring, a biphenyl ring, a naphthalene ring, a terphenyl ring, an acenaphthylene ring, a fluorene ring, a phenalene ring, a phenanthrene ring, a triphenylene ring, a pyrene ring, a naphthacene ring, a perylene ring, and a pentacene ring.
At least one hydrogen atom in the compound represented by formula (H1) may be substituted with alkyl having 1 to 6 carbon atoms, cycloalkyl having 3 to 14 carbon atoms, cyano, halogen or deuterium.

3-1-5-1-2. Compound represented by formula (H2)

In formula (H2), ^L2 and ^L3 are each independently an aryl having 6 to 30 carbon atoms or a heteroaryl having 2 to 30 carbon atoms. The aryl is preferably an aryl having 6 to 24 carbon atoms, more preferably an aryl having 6 to 16 carbon atoms, still more preferably an aryl having 6 to 12 carbon atoms, and particularly preferably an aryl having 6 to 10 carbon atoms. Specific examples of the aryl include monovalent groups such as a benzene ring, a biphenyl ring, a naphthalene ring, a terphenyl ring, an acenaphthylene ring, a fluorene ring, a phenalene ring, a phenanthrene ring, a triphenylene ring, a pyrene ring, a naphthacene ring, a perylene ring, and a pentacene ring. The heteroaryl is preferably a heteroaryl having 2 to 25 carbon atoms, more preferably a heteroaryl having 2 to 20 carbon atoms, still more preferably a heteroaryl having 2 to 15 carbon atoms, and particularly preferably a heteroaryl having 2 to 10 carbon atoms. Specific examples thereof 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 benzo Examples of monovalent groups include an imidazole ring, a benzoxazole ring, a benzothiazole ring, a 1H-benzotriazole ring, a quinoline ring, an isoquinoline ring, a cinnoline ring, a quinazoline ring, a quinoxaline ring, a phthalazine ring, a naphthyridine ring, a purine ring, a pteridine ring, a carbazole ring, an acridine ring, a phenoxathiin ring, a phenoxazine ring, a phenothiazine ring, a phenazine ring, an indolizine ring, a furan ring, a benzofuran ring, an isobenzofuran ring, a dibenzofuran ring, a thiophene ring, a benzothiophene ring, a dibenzothiophene ring, a furazan ring, an oxadiazole ring, and a thianthrene ring.
At least one hydrogen atom in the compound represented by formula (H2) may be substituted with alkyl having 1 to 6 carbon atoms, cycloalkyl having 3 to 14 carbon atoms, cyano, halogen or deuterium.

3-1-5-1-3. Compound represented by formula (H3)

In formula (H3),
Each MU is independently a divalent aromatic group, each EC is independently a monovalent aromatic group, and k is an integer of 2 to 50,000.

More specifically,
Each MU is independently arylene, heteroarylene, diarylenarylamino, diarylenarylboryl, oxaborine-diyl, or azaborine-diyl;
each E C is independently hydrogen, aryl, heteroaryl, diarylamino, diheteroarylamino, arylheteroarylamino, or aryloxy;
At least one hydrogen in MU and EC may be further substituted with aryl, heteroaryl, diarylamino, alkyl, and cycloalkyl;
k is an integer from 2 to 50,000.
k is preferably an integer from 20 to 50,000, and more preferably an integer from 100 to 50,000.

At least one hydrogen atom in MU and EC in formula (H3) may be substituted by an alkyl group having 1 to 24 carbon atoms, a cycloalkyl group having 3 to 24 carbon atoms, a halogen atom or deuterium atom; further, any -CH ₂ - in the alkyl group may be substituted by -O- or -Si(CH ₃ ) ₂ -; any -CH ₂ - in the alkyl group except for the -CH ₂ - directly bonded to EC in formula (H3) may be substituted by an arylene group having 6 to 24 carbon atoms; and any hydrogen atom in the alkyl group may be substituted by fluorine.

Examples of MU include divalent derivatives of the following structures (for example, a divalent group represented by removing any two hydrogen atoms from any of the compounds of the following structures, a divalent group composed of a combination of two or more divalent groups represented by removing any two hydrogen atoms from any of the compounds of the following structures, and a divalent group in which at least one hydrogen in such a group is substituted with an alkyl or the like).

More specifically, examples include divalent groups having any of the following structures. In these, MU bonds to another MU or EC at the *.

Examples of EC include groups represented by the following formulas. In these, EC bonds to MU at *.

From the viewpoints of solubility and coating film-forming properties, the compound represented by formula (H3) is preferably such that 10 to 100% of the total number of MUs (k) in the molecule have an alkyl having 1 to 24 carbon atoms, more preferably 30 to 100% of the total number of MUs (k) in the molecule have an alkyl having 1 to 18 carbon atoms (branched chain alkyl having 3 to 18 carbon atoms), and even more preferably 50 to 100% of the total number of MUs (k) in the molecule have an alkyl having 1 to 12 carbon atoms (branched chain alkyl having 3 to 12 carbon atoms). On the other hand, from the viewpoints of in-plane alignment and charge transport, it is preferable that 10 to 100% of the total number of MUs (k) in the molecule have an alkyl having 7 to 24 carbon atoms, and more preferably 30 to 100% of the total number of MUs (k) in the molecule have an alkyl having 7 to 24 carbon atoms (branched chain alkyl having 7 to 24 carbon atoms).

Compound containing a structure represented by formula (H4) The compound containing a structure represented by formula (H4) contains a plurality of structures represented by formula (H4), preferably 1 to 5 structures, more preferably 1 to 3 structures, even more preferably 1 to 2 structures, and most preferably 1 structure. When a plurality of structures are contained, the structures are directly bonded to each other via a single bond or a specific linking group.

In formula (H4), G is "=C(-H)-" or "=N-", and the H in the "=C(-H)-" may be substituted with a substituent or another structure represented by formula (H4).

Compounds containing the structure represented by formula (H4) can be, for example, compounds described in WO 2012/153780 and WO 2013/038650, and can be produced according to the methods described in the above documents.

When the H in "=C(-H)-" which is G is substituted, examples of the substituent include aryl, heteroaryl, substituted silyl, substituted phosphine oxide group, and substituted carboxy.

Specific examples of the "aryl" substituent include phenyl, tolyl, xylyl, naphthyl, phenanthryl, pyrenyl, chrysenyl, benzo[c]phenanthryl, benzo[g]chrysenyl, benzanthryl, triphenylenyl, fluorenyl, 9,9-dimethylfluorenyl, benzofluorenyl, dibenzofluorenyl, biphenylyl, terphenylyl, quaterphenylyl, fluoranthenyl, etc., and preferably phenyl, biphenylyl, terphenylyl, quaterphenylyl, naphthyl, triphenylenyl, and fluorenyl. Examples of aryl having a substituent include tolyl, xylyl, and 9,9-dimethylfluorenyl. As shown in the specific examples, aryl includes both fused and non-fused aryl.

Specific examples of the substituent "heteroaryl" include pyrrolyl, pyrazolyl, pyrazinyl, pyrimidinyl, pyridazinyl, pyridyl, triazinyl, indolyl, isoindolyl, imidazolyl, benzimidazolyl, indazolyl, imidazo[1,2-a]pyridinyl, furyl, benzofuranyl, isobenzofuranyl, dibenzofuranyl, azadibenzofuranyl, thienyl, benzothienyl, dibenzothienyl, azadibenzothienyl, quinolyl, isoquinolyl, quinoxalinyl, quinazolinyl, and naphthyridinyl. Examples of the aryl include carbazolyl, azacarbazolyl, phenanthridinyl, acridinyl, phenanthrolinyl, phenazinyl, phenothiazinyl, phenoxazinyl, oxazolyl, oxadiazolyl, furazanyl, benzoxazolyl, thiazolyl, thiadiazolyl, benzothiazolyl, triazolyl, and tetrazolyl. Preferred examples include dibenzofuranyl, dibenzothienyl, carbazolyl, pyridyl, pyrimidinyl, triazinyl, azadibenzofuranyl, and azadibenzothienyl. Dibenzofuranyl, dibenzothienyl, azadibenzofuranyl, and azadibenzothienyl are more preferred.

It is also preferred that the substituent "substituted silyl" is a group selected from the group consisting of substituted or unsubstituted trialkylsilyl, substituted or unsubstituted arylalkylsilyl, and substituted or unsubstituted triarylsilyl.

Specific examples of substituted or unsubstituted trialkylsilyl include trimethylsilyl and triethylsilyl. Specific examples of substituted or unsubstituted arylalkylsilyl include diphenylmethylsilyl, ditolylmethylsilyl, and phenyldimethylsilyl. Specific examples of substituted or unsubstituted triarylsilyl include triphenylsilyl and tritolylsilyl.

The "substituted phosphine oxide group" which is a substituent is also preferably a substituted or unsubstituted diarylphosphine oxide group. Specific examples of substituted or unsubstituted diarylphosphine oxide groups include diphenylphosphine oxide and ditolylphosphine oxide.

Examples of the "substituted carboxy" substituent include benzoyloxy.

Examples of linking groups that bond multiple structures represented by formula (H4) include divalent to tetravalent, divalent to trivalent, or divalent derivatives of the above-mentioned aryl or heteroaryl.

Specific examples of the compound containing the structure represented by formula (H4) are shown below.

3-1-5-1-5. Compound represented by formula (H5) and compound represented by formula (H6)
3-1-5-1-5-1. Compound represented by formula (H5)

In formula (H5), R ¹ to R ¹¹ each independently represent a hydrogen atom, an aryl group, a heteroaryl group, a diarylamino group, a diheteroarylamino group, an arylheteroarylamino group, or an aryloxy group, in which at least one hydrogen atom may be further substituted by an aryl group, a heteroaryl group, or a diarylamino group;
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 or aryloxy, and at least one hydrogen atom in these rings may be further substituted with an aryl, heteroaryl or diarylamino.
In addition, at least one (preferably 1 to 3) arbitrary --C(R ⁿ )= (n is 1 to 11) in formula (H5) may be substituted with --N=.
Furthermore, at least one hydrogen atom in the compound represented by formula (H5) may be substituted with a group represented by formula (FG-1), a group represented by formula (FG-2), or an alkyl having 1 to 24 carbon atoms, and further, any -CH ₂ - in the alkyl may be substituted with -O- or -Si(CH ₃ ) ₂ -, any -CH ₂ - in the alkyl except for the -CH ₂ - directly bonded to the compound represented by formula (H5) may be substituted with an arylene having 6 to 24 carbon atoms, and any hydrogen atom in the alkyl may be substituted with fluorine.
In addition, at least one hydrogen in the compound represented by formula (H5) may be substituted with a halogen or deuterium.

In formula (H5), adjacent groups among the substituents R ¹ to R ¹¹ of ring a, ring b, and ring c may be bonded to each other to form an aryl ring or a heteroaryl ring together with ring a, ring b, or ring c, and at least one hydrogen in the formed ring may be substituted with an aryl, heteroaryl, diarylamino, diheteroarylamino, arylheteroarylamino, or aryloxy, and at least one hydrogen in these may be further substituted with an aryl, heteroaryl, or diarylamino. However, here, "adjacent groups" refers to groups adjacent to each other on the same ring, and a compound in which "adjacent groups are bonded to each other to form an aryl ring or a heteroaryl ring together with ring a, ring b, or ring c" corresponds to, for example, compounds represented by formulae (H5-2) to (H5-17) listed below as specific compounds. That is, for example, it is a compound formed by condensing a benzene ring, an indole ring, a pyrrole ring, a benzofuran ring, or a benzothiophene ring to ring a (or ring b or ring c), and the condensed ring formed is a naphthalene ring, a carbazole ring, an indole ring, a dibenzofuran ring, or a dibenzothiophene ring, respectively.

3-1-5-1-5-2. Compound represented by formula (H6)

In formula (H6), R ¹ to R ¹⁶ each independently represent a hydrogen atom, an aryl group, a heteroaryl group, a diarylamino group, a diheteroarylamino group, an arylheteroarylamino group, or an aryloxy group, in which at least one hydrogen atom may be further substituted with an aryl group, a heteroaryl group, or a diarylamino group;
Adjacent groups among R ¹ to R ¹⁶ may be bonded to each other to form an aryl ring or a heteroaryl ring together with ring a, ring b, ring c or ring d, and at least one hydrogen atom in the formed ring may be substituted with aryl, heteroaryl, diarylamino, diheteroarylamino, arylheteroarylamino or aryloxy, and at least one hydrogen atom in these rings may be further substituted with aryl, heteroaryl or diarylamino.
In addition, at least one hydrogen atom in the compound represented by formula (H-6) may be substituted with a group represented by formula (FG-1), a group represented by formula (FG-2), or an alkyl having 1 to 24 carbon atoms, and further, any -CH ₂ - in the alkyl may be substituted with -O- or -Si(CH ₃ ) ₂ -, any -CH ₂ - in the alkyl except for the -CH ₂ - directly bonded to the compound represented by formula (H6) may be substituted with an arylene having 6 to 24 carbon atoms, and any hydrogen atom in the alkyl may be substituted with fluorine.
In addition, at least one hydrogen in the compound represented by formula (H6) may be substituted with a halogen or deuterium.

In formula (H6), adjacent groups among the substituents R ¹ to R ¹⁶ of ring a, ring b, ring c, and ring d may be bonded to each other to form an aryl ring or a heteroaryl ring together with ring a, ring b, ring c, or ring c, and at least one hydrogen in the formed ring may be substituted with an aryl, heteroaryl, diarylamino, diheteroarylamino, arylheteroarylamino, or aryloxy, and at least one hydrogen in these may be further substituted with an aryl, heteroaryl, or diarylamino. However, here, "adjacent groups" refers to groups adjacent to each other on the same ring, and a compound in which "adjacent groups are bonded to each other to form an aryl ring or a heteroaryl ring together with ring a, ring b, ring c, or ring d" can be explained with reference to, for example, compounds represented by formulas (H6-2) to (H6-5) listed below as specific compounds of formula (H6). That is, for example, it is a compound formed by condensing a benzene ring, an indole ring, a pyrrole ring, a benzofuran ring, or a benzothiophene ring to ring a (or ring b, ring c, or ring d), and the condensed ring formed is a naphthalene ring, a carbazole ring, an indole ring, a dibenzofuran ring, or a dibenzothiophene ring, respectively.

3-1-5-1-5-3. "R ¹ to R ¹¹ in formula (H5) " and "R ¹ to R ¹⁶ in formula (H6) "
"R ¹ to R ¹¹ in formula (H5)" and "R ¹ to R ¹⁶ in formula (H6)" are each independently hydrogen, aryl, heteroaryl, diarylamino, diheteroarylamino, arylheteroarylamino or aryloxy, and preferably an aryl having 6 to 30 carbon atoms, a heteroaryl having 2 to 30 carbon atoms, diarylamino (amino having two aryl groups having 6 to 30 carbon atoms), diheteroarylamino (amino having two heteroaryl groups having 2 to 30 carbon atoms), arylheteroarylamino (amino having an aryl group having 6 to 30 carbon atoms and a heteroaryl group having 2 to 30 carbon atoms) or an aryloxy having 6 to 30 carbon atoms.

Examples of the aryl in "aryl" and "diarylamino", the aryl in "arylheteroarylamino", and the aryl in "aryloxy" include a monocyclic benzene ring, a bicyclic ...

Examples of the heteroaryl in "heteroaryl" and "diheteroarylamino" and the heteroaryl in "arylheteroarylamino" 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, quinoline ring, isoquinoline ring, cinnoline ring, quinazoline ring, quinoxaline ring, phthalazine ring, naphthyridine ring, purine ring, pteridine ring, carbazole ring, acridine ring, phenoxathiin ring, phenoxazine ring, phenothiazine ring, phenazine ring, indolizine ring, furan ring, benzofuran ring, isobenzofuran ring, dibenzofuran ring, thiophene ring, benzothiophene ring, dibenzothiophene ring, furazan ring, oxadiazole ring, thianthrene ring, and monovalent groups such as the above heteroaryl substituted with N-aryl. Furthermore, as described below, those heteroaryls substituted with the aryls defined above are also defined as heteroaryls in formula (H5) and formula (H6).

In addition, at least one hydrogen atom in the aryl, heteroaryl, diarylamino, diheteroarylamino, arylheteroarylamino, or aryloxy groups explained as R ¹ to R ¹¹ in formula (H5) and R ¹ to R ¹⁶ in formula (H6) may be further substituted with an aryl, heteroaryl, or diarylamino group. Examples of the aryl, heteroaryl, or diarylamino group to be substituted in this manner include the same groups as those explained in the columns for R ¹ to R ¹¹ and R ¹ to R ¹⁶ .

Specific examples of R ¹ to R ¹¹ and R ¹ to R ¹⁶ include groups represented by the following formulae (RG-1) to (RG-10). The groups represented by the following formulae (RG-1) to (RG-10) are bonded to formula (H5) or formula (H6) at *.

With reference to the specific groups mentioned above, the definitions of "aryl" and "heteroaryl" in formulae (H5) and (H6) are as follows: Formulae (RG-1), (RG-4) and (RG-7) are aryl, Formulae (RG-2), (RG-3) and (RG-6) are heteroaryl, Formula (RG-9) is heteroaryl substituted with heteroaryl, and Formula (RG-10) is aryl substituted with heteroaryl. Formula (RG-5) is aryl (phenyl) substituted with diarylamino (diphenylamino), and Formula (RG-8) is diarylamino (diphenylamino).

3-1-5-1-5-4. In formula (H5), the ring formed by bonding adjacent groups of ring a, ring b, or ring c, and in formula (H6), the ring formed by bonding adjacent groups of ring a, ring b, ring c, or ring d, "the aryl ring formed together with ring a, ring b, or ring c by bonding adjacent groups among R ¹ to R ¹¹ " in formula (H5), and "the aryl ring formed together with ring a, ring b, ring c, or ring d by bonding adjacent groups among R ¹ to R ¹⁶ " in formula (H6) include, for example, an aryl ring having 6 to 30 carbon atoms, preferably an aryl ring having 6 to 16 carbon atoms, more preferably an aryl ring having 6 to 12 carbon atoms, and particularly preferably an aryl ring having 6 to 10 carbon atoms. However, the number of carbon atoms of the formed aryl ring includes the 6 carbon atoms of ring a, ring b, ring c, or ring d.

Specific examples of the aryl rings formed include a naphthalene ring, which is a fused bicyclic ring; an acenaphthylene ring, a fluorene ring, a phenalene ring, a phenanthrene ring, which are fused tricyclic rings; a triphenylene ring, a pyrene ring, a naphthacene ring, which are fused tetracyclic rings; a perylene ring, a pentacene ring, which are fused pentacyclic rings, and the like.

Examples of the "heteroaryl ring formed together with ring a, ring b, or ring c by bonding adjacent groups among R ¹ to R ¹¹ " in formula (H5) and the "aryl ring formed together with ring a, ring b, ring c, or ring d by bonding adjacent groups among R ¹ to R ¹⁶ " in formula (H6) include heteroaryl rings having 6 to 30 carbon atoms, preferably heteroaryl rings having 6 to 25 carbon atoms, more preferably heteroaryl rings having 6 to 20 carbon atoms, even more preferably heteroaryl rings having 6 to 15 carbon atoms, and particularly preferably heteroaryls having 6 to 10 carbon atoms. Examples of the "heteroaryl ring" include heterocycles containing, as ring-constituting atoms other than carbon, 1 to 5 heteroatoms selected from oxygen, sulfur, and nitrogen. However, the number of carbon atoms in the formed heteroaryl ring includes the 6 carbon atoms in ring a, ring b, ring c, or ring d.

Specific examples of the heteroaryl ring formed include an indole ring, an isoindole ring, a 1H-indazole ring, a benzimidazole ring, a benzoxazole ring, a benzothiazole ring, a 1H-benzotriazole ring, a quinoline ring, an isoquinoline ring, a cinnoline ring, a quinazoline ring, a quinoxaline ring, a phthalazine ring, a carbazole ring, an acridine ring, a phenoxathiin ring, a phenoxazine ring, a phenothiazine ring, a phenazine ring, a benzofuran ring, an isobenzofuran ring, a dibenzofuran ring, a benzothiophene ring, a dibenzothiophene ring, and a thianthrene ring.

At least one hydrogen atom in the formed ring may be replaced by an aryl, a heteroaryl, a diarylamino, a diheteroarylamino, an arylheteroarylamino or an aryloxy, and at least one hydrogen atom in these may be further replaced by an aryl, a heteroaryl or a diarylamino. For this explanation, the explanations in R ¹ to R ¹¹ in formula (H5) and R ¹ to R ¹⁶ in formula (H6) can be cited.

3-1-5-1-5-5. Specific examples of compounds More specific structures of the compounds represented by formula (H5) or formula (H6) are shown below.
The specific structure of the compound represented by the following formula (H5) or formula (H6) may be substituted with an alkyl group having 1 to 24 carbon atoms.

3-1-5-1-5-6. Method for producing a compound represented by formula (H5) or formula (H6) For the compound represented by formula (H5), first, rings a to c are bonded with a bonding group (-O-) to produce an intermediate (first reaction), and then rings a to c are bonded with a bonding group (group containing B) to produce a final product (second reaction). For the compound represented by formula (H6), first, rings a to d are bonded with a bonding group (>NH or single bond) to produce an intermediate (first reaction), and then rings a to d are bonded with a bonding group (group containing B) to produce a final product (second reaction). For the first reaction, for example, if it is an etherification reaction, a general reaction such as a nucleophilic substitution reaction or an Ullmann reaction can be used, and if it is an amination reaction, a general reaction such as a Buchwald-Hartwig reaction can be used. For the second reaction, a tandem hetero Friedel-Crafts reaction (successive aromatic electrophilic substitution reaction, the same applies below) can be used.

<Production Method: Example of the Second Reaction of the Compound Represented by Formula (H5)>
The second reaction is a reaction for introducing B (boron) which bonds the a ring, the b ring, and the c ring, as shown in the following scheme (1). As an example, the case of a compound represented by formula (H5) is shown below. First, the hydrogen atom between two Os is orthometalated with n-butyllithium, sec-butyllithium, t-butyllithium, or the like. Next, boron trichloride, boron tribromide, or the like is added to carry out 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, thereby obtaining the target product. In the second reaction, a Lewis acid such as aluminum trichloride may be added to promote the reaction.

In the above scheme, lithium was introduced at the desired position by orthometalation, but it is also possible to introduce lithium at the desired position by introducing a bromine atom or the like at the desired position and then performing halogen-metal exchange, as in scheme (2) below.

By appropriately selecting the above synthesis method and the raw materials to be used, it is possible to synthesize a compound represented by formula (H-5) having a substituent at the desired position.

<Production method: Example of the production method for the compound represented by formula (H6)>
The first and second reactions in the method for producing the compound represented by formula (H5) described above can also be applied to the method for producing the compound represented by formula (H6). That is, the second reaction is a reaction for introducing B (boron) which bonds NH to the c-ring and d-ring, and the hydrogen atom of NH is orthometalated with n-butyllithium, sec-butyllithium, t-butyllithium, or the like, and then boron trichloride, boron tribromide, or the like is added to carry out lithium-boron metal exchange, and further, a tandem boron-Friedel-Crafts reaction can be carried out by adding a Bronsted base such as N,N-diisopropylethylamine, to obtain the target product. Here again, in the second reaction, a Lewis acid such as aluminum trichloride may be added to promote the reaction.

3-1-5-2. TADF Material It is also preferable that the light emitting layer contains a TADF material.
In this specification, the TADF material means a material that is a "thermally activated delayed fluorescent material". In the "thermally activated delayed fluorescent material", the energy difference between the excited singlet state and the excited triplet state is reduced, so that the reverse energy transfer from the excited triplet state, which usually has a low transition probability, to the excited singlet state occurs with high efficiency, and light emission from the singlet state (thermally activated delayed fluorescence, TADF) occurs. In normal fluorescent emission, 75% of the triplet excitons generated by current excitation pass through a thermal deactivation path and cannot be extracted as fluorescence. On the other hand, in TADF, all excitons can be used for fluorescent emission, and a highly efficient organic EL element can be realized.

The TADF material is preferably a donor-acceptor type TADF compound (D-A type TADF compound) designed to localize the HOMO and LUMO within the molecule using electron-donating substituents called donors and electron-accepting substituents called acceptors, thereby allowing efficient reverse intersystem crossing to occur.

Here, in this specification, "electron-donating substituent" (donor) means a substituent or partial structure in which the HOMO orbital is localized in the TADF compound molecule, and "electron-accepting substituent" (acceptor) means a substituent or partial structure in which the LUMO orbital is localized in the TADF compound molecule.

In general, TADF compounds using donors or acceptors have a large spin orbit coupling (SOC) due to their structure, and the exchange interaction between the HOMO and LUMO is small, resulting in a small ΔE(ST), resulting in a very fast reverse intersystem crossing rate. On the other hand, TADF compounds using donors or acceptors have a large structural relaxation in the excited state (in some molecules, the stable structure differs between the ground state and the excited state, so when an external stimulus causes a transition from the ground state to the excited state, the structure then changes to the stable structure in the excited state), giving a wide emission spectrum, which may reduce the color purity when used as a light-emitting material.

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

TADF materials that can be used for this purpose include, for example, a compound represented by the following formula (H7) or a compound having the following formula (H7) as a partial structure.

In formula (H7), ED is an electron donating group, Ln is a linking group, EA is an electron accepting group, and the energy difference (ΔS ¹ T ¹ ) between the singlet energy (S ¹ ) and triplet energy (T ¹ ) of the compound represented by formula (H7) is 0.2 eV or less (Hiroki Uoyama, Kenichi Goushi, Katsuyuki Shizu, Hiroko Nomura, Chihaya Adachi, Nature, 492, 234-238 (2012)). The energy difference (ΔS ¹ T ¹ ) is preferably 0.15 eV or less, more preferably 0.10 eV or less, and even more preferably 0.08 eV or less.

As the electron donating group (donor structure) and the electron accepting group (acceptor structure) used in the TADF material, for example, the structures described in Chemistry of Materials, 2017, 29, 1946-1963 can be used. Examples of ED include functional groups containing sp ³ nitrogen, and more specifically, groups derived from carbazole, dimethylcarbazole, di-tert-butylcarbazole, dimethoxycarbazole, tetramethylcarbazole, benzofluorocarbazole, benzothienocarbazole, phenyldihydroindolocarbazole, phenylbicarbazole, bicarbazole, tercarbazole, diphenylcarbazolylamine, tetraphenylcarbazolyldiamine, phenoxazine, dihydrophenazine, phenothiazine, dimethyldihydroacridine, diphenylamine, bis(tert-butyl)phenyl)amine, (diphenylamino)phenyl)diphenylbenzenediamine, dimethyltetraphenyldihydroacridinediamine, tetramethyl-dihydro-indenoacridine, and diphenyl-dihydrodibenzoazasiline. Examples of EA include groups derived from sp ² Nitrogen-containing aromatic rings, CN-substituted aromatic rings, rings having ketones and cyano, more specifically sulfonyldibenzene, benzophenone, phenylenebis(phenylmethanone), benzonitrile, isonicotinonitrile, phthalonitrile, isophthalonitrile, paraphthalonitrile, triazole, oxazole, thiadiazole, benzothiazole, benzobis(thiazole), benzoxazole, benzobis(oxazole), quinoline, benzimidazole, dibenzoquinoxaline, heptaazaphenalene, thioxanthone dioxane, Examples of the group derived from cyclohexyl ether, dimethylanthracenone, anthracenedione, pyridine, cycloheptabipyridine, benzenetricarbonitrile, fluorene dicarbonitrile, pyrazine dicarbonitrile, pyridine dicarbonitrile, dibenzoquinoxaline dicarbonitrile, pyrimidine, phenylpyrimidine, methylpyrimidine, triazine, triphenyltriazine, bis(phenylsulfonyl)benzene, dimethylthioxanthene dioxide, thianthrene tetraoxide, and tris(dimethylphenyl)borane. Examples of Ln include single bonds and arylenes, more specifically, phenylene, biphenylene, naphthylene, and the like. In addition, in any of the structures, hydrogen may be substituted with alkyl, cycloalkyl, and aryl. In particular, it is preferable that the compound has at least one partial structure selected from carbazole, phenoxazine, acridine, triazine, pyrimidine, pyrazine, thioxanthene, benzonitrile, phthalonitrile, isophthalonitrile, diphenylsulfone, triazole, oxadiazole, thiadiazole, and benzophenone.
In formula (H7), the linking group Ln functions as a spacer structure that separates the donor partial structure and the acceptor partial structure.

More specifically, the compound represented by formula (H7) may be any of the compounds represented by formulas (H7-1), (H7-2) and (H7-3).

In formulas (H7-1), (H7-2) and (H7-3),
M is each independently a single bond, -O-, >N-Ar or >C(-Ar) ₂ , and is preferably a single bond, -O- or >N-Ar from the viewpoint of the HOMO depth and the height of the excited singlet energy level and the excited triplet energy level of the partial structure to be formed,
J is a linking group corresponding to Ln in formula (H7), and each J is independently an arylene having 6 to 18 carbon atoms. From the viewpoint of the magnitude of conjugation exuded from the donor partial structure and the acceptor partial structure, an arylene having 6 to 12 carbon atoms is preferable, and more specific examples thereof include phenylene, methylphenylene, and dimethylphenylene.
Q is each independently ═C(—H)— or ═N—, and is preferably ═N— from the viewpoint of the shallowness of the LUMO and the height of the excited singlet energy level and the excited triplet energy level of the partial structure to be formed,
Ar are each independently hydrogen, an aryl having 6 to 24 carbon atoms, a heteroaryl having 2 to 24 carbon atoms, an alkyl having 1 to 12 carbon atoms, or a cycloalkyl having 3 to 18 carbon atoms; from the viewpoint of the HOMO depth and the height of the excited singlet energy level and the excited triplet energy level of the partial structure to be formed, preferably hydrogen, an aryl having 6 to 12 carbon atoms, a heteroaryl having 2 to 14 carbon atoms, an alkyl having 1 to 4 carbon atoms, or a cycloalkyl having 6 to 10 carbon atoms, more preferably hydrogen, phenyl, tolyl, xylyl, mesityl, biphenyl, pyridyl, bipyridyl, triazyl, carbazolyl, dimethylcarbazolyl, di-tert-butylcarbazolyl, benzimidazole, or phenylbenzimidazole, and further preferably hydrogen, phenyl, or carbazolyl;
m is 1 or 2;
n is an integer of 2 to (6-m), and from the viewpoint of steric hindrance, is preferably an integer of 4 to (6-m).
Furthermore, at least one hydrogen atom in the compounds represented by the above formulas may be substituted with a halogen or deuterium.

Examples of compounds represented by formula (H7) include compounds represented by the following structures. In the structural formula, * indicates the bond position, "Me" indicates methyl, and "tBu" indicates t-butyl.

Among the specific compounds represented by formula (H7), PIC-TRZ, TXO-TPA, TXO-PhCz, PXZD SO2, ACRD SO2, DTC-DBT, DTAO, 4CzBN, 4CzBN-Ph, 5CzBN, 3Cz2DPhCzBN, 4CzIPN, 2PXZ-TAZ, Cz-TRZ3, BDPCC-TPTA, MA-TA, PA-TA, FA-TA, PXZ-TRZ, DMAC-TRZ, BCzT, DCzTrz, DDCzTrz, spiroAC-TRZ, Ac-HPM, Ac-PPM, Ac-MPM, TCzTrz, TmCzTrz and DCzmCzTrz are preferred.

3-1-5-3. Dopant Material The polycyclic aromatic compound of the present invention is preferably used as a dopant material.
Dopant materials that can be used other than the polycyclic aromatic compound of the present invention are not particularly limited, and known compounds can be used, and can be selected from various materials according to the desired emission color.Specific examples of the dopant materials include condensed ring derivatives such as phenanthrene, anthracene, pyrene, tetracene, pentacene, perylene, naphthopyrene, dibenzopyrene, rubrene, and chrysene, benzoxazole derivatives, benzothiazole derivatives, benzimidazole derivatives, benzotriazole derivatives, oxazole derivatives, oxadiazole derivatives, thiazole derivatives, imidazole derivatives, thiadiazole derivatives, triazole derivatives, pyrazoline derivatives, stilbene derivatives, thiophene derivatives, and tetraphenylbutadiene. derivatives, cyclopentadiene derivatives, bisstyryl derivatives such as bisstyrylanthracene derivatives and distyrylbenzene derivatives (JP Patent Publication No. 1-245087), bisstyrylarylene derivatives (JP Patent Publication No. 2-247278), diazaindacene derivatives, furan derivatives, benzofuran derivatives, isobenzofuran derivatives such as phenylisobenzofuran, dimesitylisobenzofuran, di(2-methylphenyl)isobenzofuran, di(2-trifluoromethylphenyl)isobenzofuran, and phenylisobenzofuran coumarin derivatives such as dibenzofuran derivatives, 7-dialkylaminocoumarin derivatives, 7-piperidinocoumarin derivatives, 7-hydroxycoumarin derivatives, 7-methoxycoumarin derivatives, 7-acetoxycoumarin derivatives, 3-benzothiazolylcoumarin derivatives, 3-benzimidazolylcoumarin derivatives, and 3-benzoxazolylcoumarin derivatives, dicyanomethylenepyran derivatives, dicyanomethylenethiopyran derivatives, polymethine derivatives, cyanine derivatives, oxobenzoanthracene derivatives, xanthene derivatives, rhodamine derivatives, conductors, fluorescein derivatives, pyrylium derivatives, carbostyril derivatives, acridine derivatives, oxazine derivatives, phenylene oxide derivatives, quinacridone derivatives, quinazoline derivatives, pyrrolopyridine derivatives, furopyridine derivatives, 1,2,5-thiadiazolopyrene derivatives, pyrromethene derivatives, perinone derivatives, pyrrolopyrrole derivatives, squarylium derivatives, violanthrone derivatives, phenazine derivatives, acridone derivatives, deazaflavin derivatives, fluorene derivatives and benzofluorene derivatives.

As examples of dopant materials for each color of light emitted, blue to blue-green dopant materials include aromatic hydrocarbon compounds such as naphthalene, anthracene, phenanthrene, pyrene, triphenylene, perylene, fluorene, indene, and chrysene, and their derivatives, as well as furan, pyrrole, thiophene, silole, 9-silafluorene, 9,9'-spirobisilafluorene, benzothiophene, benzofuran, indole, dibenzothiophene, dibenzofuran, imidazopyridine, phenanthroline, pyrazine, naphthyridine, quinoxaline, pyrrolopyridine, and pyrrolopyridine. Examples include aromatic heterocyclic compounds such as lysine and thioxanthene and their derivatives, distyrylbenzene derivatives, tetraphenylbutadiene derivatives, stilbene derivatives, aldazine derivatives, coumarin derivatives, azole derivatives such as imidazole, thiazole, thiadiazole, carbazole, oxazole, oxadiazole, and triazole, and metal complexes thereof, and aromatic amine derivatives such as N,N'-diphenyl-N,N'-di(3-methylphenyl)-4,4'-diphenyl-1,1'-diamine.

In addition, examples of green to yellow dopant materials include coumarin derivatives, phthalimide derivatives, naphthalimide derivatives, perinone derivatives, pyrrolopyrrole derivatives, cyclopentadiene derivatives, acridone derivatives, quinacridone derivatives, and naphthacene derivatives such as rubrene. Further, suitable examples include compounds in which a substituent that enables longer wavelengths, such as aryl, heteroaryl, arylvinyl, amino, or cyano, has been introduced into the compounds exemplified as the blue to blue-green dopant materials above.

Further, examples of orange to red dopant materials include naphthalimide derivatives such as bis(diisopropylphenyl)perylenetetracarboxylic acid imide, perinone derivatives, rare earth complexes such as Eu complexes with ligands such as acetylacetone, benzoylacetone and phenanthroline, 4-(dicyanomethylene)-2-methyl-6-(p-dimethylaminostyryl)-4H-pyran and its analogues, metal phthalocyanine derivatives such as magnesium phthalocyanine and aluminum chlorophthalocyanine, rhodamine compounds, deazaflavin derivatives, coumarin derivatives, quinacridone derivatives, phenoxazine derivatives, oxazine derivatives, quinazoline derivatives, pyrrolopyridine derivatives, squarylium derivatives, violanthrone derivatives, phenazine derivatives, phenoxazone derivatives and thiadiazolopyrene derivatives. Further, compounds in which a substituent that enables longer wavelengths, such as aryl, heteroaryl, arylvinyl, amino and cyano, is introduced into the compounds exemplified as the above blue to blue-green and green to yellow dopant materials, are also suitable examples.

As other dopants, compounds described in Chemical Industry, June 2004, p. 13 and references cited therein can be appropriately selected and used.

Among the dopant materials described above, amines having a stilbene structure, perylene derivatives, borane derivatives, aromatic amine derivatives, coumarin derivatives, pyran derivatives, or pyrene derivatives are particularly preferred.

当該式中、Ａｒ¹は炭素数６～３０のアリールに由来するｍ価の基であり、Ａｒ²およびＡｒ³は、それぞれ独立して炭素数６～３０のアリールであるが、Ａｒ¹～Ａｒ³の少なくとも１つはスチルベン構造を有し、Ａｒ¹～Ａｒ³は、アリール、ヘテロアリール、アルキル、シクロアルキル、トリ置換シリル（アリール、アルキルおよび／またはシクロアルキルでトリ置換されたシリル）またはシアノで置換されていてもよく、そして、ｍは１～４の整数である。 The amine having a stilbene structure is represented, for example, by the following formula.

In the formula, Ar ¹ is an m-valent group derived from an aryl having 6 to 30 carbon atoms, Ar ² and Ar ³ are each independently an aryl having 6 to 30 carbon atoms, at least one of Ar ¹ to Ar ³ has a stilbene structure, Ar ¹ to Ar ³ may be substituted with an aryl, heteroaryl, alkyl, cycloalkyl, tri-substituted silyl (silyl tri-substituted with aryl, alkyl and/or cycloalkyl) or cyano, and m is an integer of 1 to 4.

当該式中、Ａｒ²およびＡｒ³は、それぞれ独立して炭素数６～３０のアリールであり、Ａｒ²およびＡｒ³は、アリール、ヘテロアリール、アルキル、シクロアルキル、トリ置換シリル（アリール、アルキルおよび／またはシクロアルキルでトリ置換されたシリル）またはシアノで置換されていてもよい。 The amine having a stilbene structure is more preferably a diaminostilbene represented by the following formula.

In the formula, Ar ² and Ar ³ are each independently an aryl having 6 to 30 carbon atoms, and Ar ² and Ar ³ may be substituted with an aryl, heteroaryl, alkyl, cycloalkyl, tri-substituted silyl (silyl tri-substituted with aryl, alkyl and/or cycloalkyl), or cyano.

Specific examples of aryls having 6 to 30 carbon atoms include phenyl, naphthyl, acenaphthylenyl, fluorenyl, phenalenyl, phenanthrenyl, anthryl, fluoranthenyl, triphenylenyl, pyrenyl, chrysenyl, naphthacenyl, perylenyl, stilbenyl, distyrylphenyl, distyrylbiphenylyl, and distyrylfluorenyl.

Specific examples of the amine having a stilbene structure include N,N,N',N'-tetra(4-biphenylyl)-4,4'-diaminostilbene, N,N,N',N'-tetra(1-naphthyl)-4,4'-diaminostilbene, N,N,N',N'-tetra(2-naphthyl)-4,4'-diaminostilbene, N,N'-di(2-naphthyl)-N,N'-diphenyl-4,4'-diaminostilbene, and N,N'-di(9-phenanthryl)-N,N'-diphenyl-4,4'-diaminostilbene. 4,4'-bis(9-ethyl-3-carbazovinylene)-biphenyl, 4,4'-bis(9-phenyl-3-carbazovinylene)-biphenyl, and the like.
Furthermore, amines having a stilbene structure as described in JP-A Nos. 2003-347056 and 2001-307884 may also be used.

Examples of perylene derivatives include 3,10-bis(2,6-dimethylphenyl)perylene, 3,10-bis(2,4,6-trimethylphenyl)perylene, 3,10-diphenylperylene, 3,4-diphenylperylene, 2,5,8,11-tetra-t-butylperylene, 3,4,9,10-tetraphenylperylene, 3-(1'-pyrenyl)-8,11-di(t-butyl)perylene, 3-(9'-anthryl)-8,11-di(t-butyl)perylene, and 3,3'-bis(8,11-di(t-butyl)perylenyl).
Also usable are perylene derivatives described in JP-A-11-97178, JP-A-2000-133457, JP-A-2000-26324, JP-A-2001-267079, JP-A-2001-267078, JP-A-2001-267076, JP-A-2000-34234, JP-A-2001-267075, and JP-A-2001-217077.

Examples of the borane derivatives include 1,8-diphenyl-10-(dimesitylboryl)anthracene, 9-phenyl-10-(dimesitylboryl)anthracene, 4-(9'-anthryl)dimesitylborylnaphthalene, 4-(10'-phenyl-9'-anthryl)dimesitylborylnaphthalene, 9-(dimesitylboryl)anthracene, 9-(4'-biphenylyl)-10-(dimesitylboryl)anthracene, and 9-(4'-(N-carbazolyl)phenyl)-10-(dimesitylboryl)anthracene.
Furthermore, borane derivatives described in International Publication No. 2000/40586 and the like may also be used.

当該式中、Ａｒ⁴は炭素数６～３０のアリールに由来するｎ価の基であり、Ａｒ⁵およびＡｒ⁶はそれぞれ独立して炭素数６～３０のアリールであり、Ａｒ⁴～Ａｒ⁶は、アリール、ヘテロアリール、アルキル、シクロアルキル、トリ置換シリル（アリール、アルキルおよび／またはシクロアルキルでトリ置換されたシリル）またはシアノで置換されていてもよく、そして、ｎは１～４の整数である。 The aromatic amine derivative is represented, for example, by the following formula:

In the formula, Ar ⁴ is an n-valent group derived from an aryl having 6 to 30 carbon atoms, Ar ⁵ and Ar ⁶ are each independently an aryl having 6 to 30 carbon atoms, Ar ⁴ to Ar ⁶ may be substituted with an aryl, heteroaryl, alkyl, cycloalkyl, tri-substituted silyl (silyl tri-substituted with aryl, alkyl and/or cycloalkyl) or cyano, and n is an integer from 1 to 4.

In particular, an aromatic amine derivative in which Ar ⁴ is a divalent group derived from anthracene, chrysene, fluorene, benzofluorene or pyrene, Ar ⁵ and Ar ⁶ are each independently an aryl having 6 to 30 carbon atoms, Ar ⁴ to Ar ⁶ may be substituted with an aryl, heteroaryl, alkyl, cycloalkyl, tri-substituted silyl (silyl tri-substituted with an aryl, alkyl and/or cycloalkyl) or cyano, and n is 2 is more preferred.

Specific examples of aryls having 6 to 30 carbon atoms include phenyl, naphthyl, acenaphthylenyl, fluorenyl, phenalenyl, phenanthrenyl, anthryl, fluoranthenyl, triphenylenyl, pyrenyl, chrysenyl, naphthacenyl, perylenyl, and pentacenyl.

As aromatic amine derivatives, examples of chrysene derivatives include N,N,N',N'-tetraphenylchrysene-6,12-diamine, N,N,N',N'-tetra(p-tolyl)chrysene-6,12-diamine, N,N,N',N'-tetra(m-tolyl)chrysene-6,12-diamine, N,N,N',N'-tetrakis(4-isopropylphenyl)chrysene-6,12-diamine, N,N,N',N'-tetra(naphthalen-2-yl)chrysene-6,12-diamine, and N,N'-diphenyl Examples include -N,N'-di(p-tolyl)chrysene-6,12-diamine, N,N'-diphenyl-N,N'-bis(4-ethylphenyl)chrysene-6,12-diamine, N,N'-diphenyl-N,N'-bis(4-isopropylphenyl)chrysene-6,12-diamine, N,N'-diphenyl-N,N'-bis(4-t-butylphenyl)chrysene-6,12-diamine, and N,N'-bis(4-isopropylphenyl)-N,N'-di(p-tolyl)chrysene-6,12-diamine.

Examples of pyrene-based compounds include N,N,N',N'-tetraphenylpyrene-1,6-diamine, N,N,N',N'-tetra(p-tolyl)pyrene-1,6-diamine, N,N,N',N'-tetra(m-tolyl)pyrene-1,6-diamine, N,N,N',N'-tetrakis(4-isopropylphenyl)pyrene-1,6-diamine, N,N,N',N'-tetrakis(3,4-dimethylphenyl)pyrene-1,6-diamine, N,N'-diphenyl-N,N'-di(p-tolyl)pyrene-1,6-diamine, and N,N'-diphenyl-N,N'-bis(4-ethylphenyl)pyrene-1, 6-diamine, N,N'-diphenyl-N,N'-bis(4-isopropylphenyl)pyrene-1,6-diamine, N,N'-diphenyl-N,N'-bis(4-t-butylphenyl)pyrene-1,6-diamine, N,N'-bis(4-isopropylphenyl)-N,N'-di(p-tolyl)pyrene-1,6-diamine, N,N,N',N'-tetrakis(3,4-dimethylphenyl)-3,8-diphenylpyrene-1,6-diamine, N,N,N,N-tetraphenylpyrene-1,8-diamine, N,N'-bis(biphenyl-4-yl)-N,N'-diphenylpyrene-1,8-diamine, N ¹ ,N ⁶ -diphenyl- ^{N 1} ,N ⁶ -bis-(4-trimethylsilanyl-phenyl)-1H,8H-pyrene-1,6-diamine and the like.

Examples of anthracene-based compounds include N,N,N,N-tetraphenylanthracene-9,10-diamine, N,N,N',N'-tetra(p-tolyl)anthracene-9,10-diamine, N,N,N',N'-tetra(m-tolyl)anthracene-9,10-diamine, N,N,N',N'-tetrakis(4-isopropylphenyl)anthracene-9,10-diamine, N,N'-diphenyl-N,N'-di(p-tolyl)anthracene-9,10-diamine, N,N'-diphenyl-N,N'-di(m-tolyl)anthracene-9,10 -diamine, N,N'-diphenyl-N,N'-bis(4-ethylphenyl)anthracene-9,10-diamine, N,N'-diphenyl-N,N'-bis(4-isopropylphenyl)anthracene-9,10-diamine, N,N'-diphenyl-N,N'-bis(4-t-butylphenyl)anthracene-9,10-diamine, N,N'-bis(4-isopropylphenyl)-N,N'-di(p-tolyl)anthracene-9,10-diamine, 2,6-di-t-butyl-N,N,N',N'-tetra(p-tolyl)anthracene-9,10-diamine 2,6-di-t-butyl-N,N'-diphenyl-N,N'-bis(4-isopropylphenyl)anthracene-9,10-diamine, 2,6-di-t-butyl-N,N'-bis(4-isopropylphenyl)-N,N'-di(p-tolyl)anthracene-9,10-diamine, 2,6-dicyclohexyl-N,N'-bis(4-isopropylphenyl)-N,N'-di(p-tolyl)anthracene-9,10-diamine, 2,6-dicyclohexyl-N,N'-bis(4-isopropylphenyl)-N,N'-bis(4-t-butylphenyl)anthracene Examples include anthracene-9,10-diamine, 9,10-bis(4-diphenylamino-phenyl)anthracene, 9,10-bis(4-di(1-naphthylamino)phenyl)anthracene, 9,10-bis(4-di(2-naphthylamino)phenyl)anthracene, 10-di-p-tolylamino-9-(4-di-p-tolylamino-1-naphthyl)anthracene, 10-diphenylamino-9-(4-diphenylamino-1-naphthyl)anthracene, and 10-diphenylamino-9-(6-diphenylamino-2-naphthyl)anthracene.

Other examples include [4-(4-diphenylamino-phenyl)naphthalene-1-yl]-diphenylamine, [6-(4-diphenylamino-phenyl)naphthalene-2-yl]-diphenylamine, 4,4'-bis[4-diphenylaminonaphthalene-1-yl]biphenyl, 4,4'-bis[6-diphenylaminonaphthalene-2-yl]biphenyl, 4,4"-bis[4-diphenylaminonaphthalene-1-yl]-p-terphenyl, and 4,4"-bis[6-diphenylaminonaphthalene-2-yl]-p-terphenyl.
Furthermore, aromatic amine derivatives described in JP-A-2006-156888 and the like may also be used.

Examples of the coumarin derivatives include coumarin-6 and coumarin-334.
Furthermore, coumarin derivatives described in JP-A-2004-43646, JP-A-2001-76876, JP-A-6-298758, and the like may also be used.

また、特開２００５－１２６３９９号公報、特開２００５－０９７２８３号公報、特開２００２－２３４８９２号公報、特開２００１－２２０５７７号公報、特開２００１－０８１０９０号公報、および特開２００１－０５２８６９号公報などに記載されたピラン誘導体を用いてもよい。 Examples of the pyran derivative include the following DCM and DCJTB.

Furthermore, pyran derivatives described in JP-A-2005-126399, JP-A-2005-097283, JP-A-2002-234892, JP-A-2001-220577, JP-A-2001-081090, JP-A-2001-052869, and the like may also be used.

3-1-6. 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 transfer compounds in photoconductive materials and known compounds used in the electron injection layer and electron transport layer of organic EL elements.

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, arylnitrile derivatives, and indole derivatives. Examples of metal complexes having electron-accepting nitrogen include hydroxyazole complexes such as hydroxyphenyloxazole complexes, azomethine complexes, tropolone metal complexes, flavonol metal complexes, and benzoquinoline metal complexes. These materials can be used alone or in combination with different materials.

Specific examples of other electron transport compounds include pyridine derivatives, naphthalene derivatives, anthracene derivatives, benzofluorene 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 pyrazine 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, arylnitrile derivatives, indole derivatives, phosphine 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, arylnitrile derivatives, triazine derivatives, benzimidazole derivatives, phenanthroline derivatives, and quinolinol-based metal complexes are preferred.

式（ＥＴＭ－１）中、Ｒ¹¹およびＲ¹²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１つであり、Ｒ¹³～Ｒ¹⁶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 formula (ETM-1), and is disclosed in detail in JP-A-2007-27587.

In formula (ETM-1), 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 represents optionally substituted arylene, Y represents optionally substituted aryl having 16 or less carbon atoms, substituted boryl, or optionally substituted carbazolyl, and n represents 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、Ｒ¹¹およびＲ¹²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１つであり、Ｒ¹³～Ｒ¹⁶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、Ｒ²¹およびＲ²²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１つであり、Ｘ¹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、Ｒ¹¹およびＲ¹²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１つであり、Ｒ¹³～Ｒ¹⁶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、Ｘ¹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 formula (ETM-1), compounds represented by the following formula (ETM-1-1) and compounds represented by the following 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 represents an optionally substituted arylene having 20 or less carbon atoms, and each n represents 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、シクロアルキルまたは置換されていてもよいフェニルであり、＊は結合位置を表す。） Specific examples of ^X1 include divalent groups represented by any one of the following formulas (X-1) to (X-9).

(In each formula, R ^a is independently alkyl, cycloalkyl, or optionally substituted phenyl, and * represents the bonding position.)

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 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 formula (ETM-2-2), R ¹¹ and R ¹² each independently represent 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 one of the following formulae (Py-1) to (Py-15) (in the formulae, * indicates a bonding position), 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. Specific examples include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, s-butyl, and t-butyl, with methyl being preferred. In addition, the pyridine-based substituent may be bonded to the φ, anthracene ring, or fluorene ring in each formula via phenylene or naphthylene.

The pyridine-based substituent is any one of the formulae (Py-1) to (Py-15) (wherein * represents a bonding position), and among these, any one of the following formulae (Py-21) to (Py-44) is preferable.

At least one hydrogen in each pyridine derivative may be replaced with deuterium, and one of the two "pyridine-based substituents" in formula (ETM-2-1) and formula (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, n-hexyl, 1-methylpentyl, 4-methyl-2-pentyl, 3,3-dimethylbutyl, 2-ethylbutyl, n-heptyl, 1-methylhexyl, n-octyl, t-octyl, 1-methylheptyl, 2 -Ethylhexyl, 2-propylpentyl, n-nonyl, 2,2-dimethylheptyl, 2,6-dimethyl-4-heptyl, 3,5,5-trimethylhexyl, n-decyl, n-undecyl, 1-methyldecyl, n-dodecyl, n-tridecyl, 1-hexylheptyl, n-tetradecyl, n-pentadecyl, n-hexadecyl, n-heptadecyl, n-octadecyl, n-eicosyl, etc.

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, more preferably an aryl having 6 to 18 carbon atoms, even more preferably an aryl having 6 to 14 carbon atoms, and particularly preferably 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 formula (ETM-2-2), R ¹¹ and R ¹² may be bonded to form a ring. 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 formula (ETM-3), and is disclosed in detail in WO 2010/134352.

In formula (ETM-3), ^X12 to ^X21 each represent hydrogen, halogen, linear, branched or cyclic alkyl, linear, branched or cyclic alkoxy, substituted or unsubstituted aryl, or substituted or unsubstituted heteroaryl, where the substituent in the case of substitution includes aryl, heteroaryl, alkyl, cycloalkyl, etc.

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 compounds represented by formulas (1A) and (1B) 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 of the anthracene derivatives is, for example, a compound represented by the following formula (ETM-5).

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

Each ^Ar2 is independently an aryl having 6 to 20 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 the "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-yl, m-terphenyl-4'-yl, p-terphenyl-2 ...4'-yl, p-terphenyl-2-yl, m-terphenyl-2-yl, m-terphenyl-3-yl, m-terphenyl-4'-yl, p-terphenyl-2-yl, m-terphenyl-4'-yl, p-terphenyl-2-yl, m-terphenyl-2-yl, m-terphenyl-3-yl, m aryl, o-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, and the like. Specific examples of the "aryl having 6 to 10 carbon atoms" include phenyl, biphenylyl, naphthyl, terphenylyl, anthracenyl, acenaphthylenyl, fluorenyl, phenalenyl, phenanthryl, triphenylenyl, pyrenyl, tetracenyl, and perylenyl.

R ¹ to R ⁴ are each independently hydrogen, alkyl having 1 to 6 carbon atoms, cycloalkyl having 3 to 6 carbon atoms, or aryl having 6 to 20 carbon atoms.
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, n-hexyl, 1-methylpentyl, 4-methyl-2-pentyl, 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 in 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 the "aryl having 6 to 20 carbon atoms" include the specific examples of the "aryl having 6 to 20 carbon atoms" in Ar ^2. Preferred examples of the "aryl having 6 to 20 carbon atoms" include 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.

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 Ar ² of formula (ETM-5) 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, n-hexyl, 1-methylpentyl, 4-methyl-2-pentyl, 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 , 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 particularly preferred 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.

<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 and WO 2013/079678.

R ⁵ is a substituted or unsubstituted alkyl having 1 to 20 carbon atoms, cycloalkyl having 3 to 16 carbon atoms, aryl having 6 to 20 carbon atoms, or heteroaryl 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, alkyl, cycloalkyl, aralkyl, alkenyl, cycloalkenyl, alkynyl, alkoxy, alkylthio, cycloalkylthio, aryl ether (aryl ether group), aryl thioether (aryl thioether group), aryl, heterocyclic group, halogen, cyano, aldehyde, carbonyl, carboxyl, amino, nitro, silyl, and a fused ring formed between adjacent substituents.

Ar ¹ may be the same or different and is arylene or heteroarylene. Ar ² may be the same or different and is aryl or heteroaryl. 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, alkyl refers to saturated aliphatic hydrocarbon groups such as methyl, ethyl, propyl, and butyl, which may be unsubstituted or substituted. If substituted, there is no particular limit to the substituent, and examples include alkyl, aryl, and heterocyclic groups, which is also the case in the following descriptions. In addition, the number of carbon atoms in the alkyl is not particularly limited, but is usually in the range of 1 to 20 from the standpoint of ease of availability and cost.

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

Also, aralkyl refers to an aromatic hydrocarbon group via an aliphatic hydrocarbon such as benzyl or phenylethyl, 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 refers to an unsaturated aliphatic hydrocarbon group containing a double bond, such as vinyl, allyl, or butadienyl, which may be unsubstituted or substituted. The number of carbon atoms in an alkenyl is not particularly limited, but is usually in the range of 2 to 20.

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

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

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

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

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

Also, aryl ether refers to an aromatic hydrocarbon group, such as phenoxy, 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 is not particularly limited, but is usually in the range of 6 to 40.

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

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

Heterocyclic groups refer to cyclic structural groups having atoms other than carbon, such as furanyl, thienyl, oxazolyl, pyridyl, quinolinyl, and carbazolyl, 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.

Aldehyde, carbonyl, and amino 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.

Silyl refers to a silicon compound group such as trimethylsilyl, which may be unsubstituted or substituted. The number of carbon atoms in silyl 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 ^Ar1 and ^R2 , ^Ar1 and ^R3 , Ar2 and ^R2 , ^{Ar2 and R3} , ^R2 and ^R3 , ^Ar1 and ^Ar2 , etc. Here, when n is 1, two ^R1s 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.

<Aryl nitrile derivatives>
The arylnitrile 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 the specification of U.S. Patent Application Publication No. 2014/0197386.

From the viewpoint of fast electron transportability, Ar _ni preferably has a large number of carbon atoms, and from the viewpoint of high T1, Ar _{ni preferably has a small number of carbon atoms. Specifically, Ar ni} preferably has a high T1 when used in a layer adjacent to the light-emitting layer, and is an aryl having 6 to 20 carbon atoms, preferably an aryl having 6 to 14 carbon atoms, and more preferably an aryl having 6 to 10 carbon atoms. In addition, the number of nitrile group substitutions n is preferably large from the viewpoint of high T1, and is preferably small from the viewpoint of high S1. Specifically, the number of nitrile group substitutions n is an integer of 1 to 4, preferably an integer of 1 to 3, more preferably an integer of 1 to 2, and even more preferably 1.

Each Ar is independently an aryl which may be substituted, or a heteroaryl which may be substituted. From the viewpoint of high S1 and high T1, it is preferable that the heteroaryl has donor properties, and since it is used as an electron transport layer, it is preferable that there are few heteroaryl donors. From the viewpoint of charge transport, it is preferable that the aryl or heteroaryl has a large number of carbon atoms, and it is preferable that it has many substituents. Specifically, the number of substitutions m of Ar is an integer of 1 to 4, preferably an integer of 1 to 3, and more preferably 1 to 2.

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 arylnitrile derivative may be a polymer in which a plurality of compounds represented by formula (ETM-9) are bonded together by single bonds or the like. In this case, in addition to single bonds, the compounds 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 arylnitrile derivative include the following compounds:

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

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 Application 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 in the "pyridine-based substituent" in formulas (ETM-2), (ETM-2-1), and (ETM-2-2) is replaced with benzoimidazolyl, and at least one hydrogen in the benzimidazole derivative may be replaced with deuterium.

R ¹¹ in the benzimidazolyl 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 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 referred to in the explanation of formula (ETM-2-1) or formula (ETM-2-2), and for R ¹¹ to R ¹⁸ in each formula, the explanation of formula (ETM-2-1) or formula (ETM-2-2) can be referred to. In addition, in formula (ETM-2-1) or formula (ETM-2-2), two pyridine-based substituents are explained as being bonded, 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 any 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 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 this 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, 5-(10-(naphthalen-2-yl)anthracen-9-yl)-1,2-diphenyl-1H-benzo[d]imidazole, Examples include 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, and 5-(9,10-di(naphthalene-2-yl)anthracen-2-yl)-1,2-diphenyl-1H-benzo[d]imidazole.

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 formula (ETM-12-1), any of R ¹¹ to R ¹⁸ is a bond 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 formula: In the structural formula, each R is independently hydrogen, methyl, ethyl, isopropyl, cyclohexyl, phenyl, 1-naphthyl, 2-naphthyl, biphenylyl or terphenylyl, and * indicates the bonding 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、Ｒ¹～Ｒ⁶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 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 in the "pyridine-based substituent" in formulae (ETM-2), (ETM-2-1), and (ETM-2-2) is replaced with the following thiazolyl or benzothiazolyl, and at least one hydrogen in the thiazole derivative and benzothiazole derivative may be replaced with deuterium.

It is further preferred that φ is an anthracene ring or a fluorene ring, and in this case, the structure can be referred to in the explanation of formula (ETM-2-1) or formula (ETM-2-2), and for R ¹¹ to R ¹⁸ in each formula, the explanation of formula (ETM-2-1) or formula (ETM-2-2) can be referred to. In addition, in 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 any 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 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.

<Silole derivatives>
The silole derivative is, for example, a compound represented by the following formula (ETM-15), the details of which are described in JP-A-9-194487.

X and Y are each independently an alkyl, cycloalkyl, alkenyl, alkynyl, alkoxy, alkenyloxy, alkynyloxy, aryl, or heteroaryl, which may be substituted. For details of these groups, the explanations in formula (1A) and formula (1B) and further the explanation in formula (ETM-7-2) can be cited. In addition, alkenyloxy and alkynyloxy are groups in which the alkyl portion of alkoxy is replaced with alkenyl or alkynyl, respectively, and for details of these alkenyls and alkynyls, the explanation in formula (ETM-7-2) can be cited.
Furthermore, X and Y, both of which are alkyl, may be bonded to form a ring.

R ¹ to R ⁴ are each independently hydrogen, halogen, alkyl, cycloalkyl, alkoxy, aryloxy, amino, alkylcarbonyl, arylcarbonyl, alkoxycarbonyl, aryloxycarbonyl, azo group, alkylcarbonyloxy, arylcarbonyloxy, alkoxycarbonyloxy, aryloxycarbonyloxy, sulfinyl, sulfonyl, sulfanyl, silyl, carbamoyl, aryl, heteroaryl, alkenyl, alkynyl, nitro, formyl, nitroso, formyloxy, isocyano, cyanate group, isocyanate group, thiocyanate group, isothiocyanate group, or cyano, which may be substituted with alkyl, cycloalkyl, aryl or halogen and may form a condensed ring with an adjacent substituent.

For details of halogen, alkyl, cycloalkyl, alkoxy, aryloxy, amino, aryl, heteroaryl, alkenyl and alkynyl in R ¹ to R ⁴ , the explanations in formula (1A) and formula (1B) can be referred to.

For details of the alkyl, aryl and alkoxy in the alkylcarbonyl, arylcarbonyl, alkoxycarbonyl, aryloxycarbonyl, alkylcarbonyloxy, arylcarbonyloxy, alkoxycarbonyloxy and aryloxycarbonyloxy in R ¹ to R ⁴ , the explanations in formula (1A) and formula (1B) can be cited.

Examples of silyl include a silyl group and a group in which at least one of the three hydrogen atoms of the silyl group is independently substituted with an aryl, alkyl, or cycloalkyl. Tri-substituted silyl is preferred, and examples include triarylsilyl, trialkylsilyl, tricycloalkylsilyl, dialkylcycloalkylsilyl, and alkyldicycloalkylsilyl. For details of the aryl, alkyl, and cycloalkyl, see the explanations in formula (1A) and formula (1B).

The fused ring formed between adjacent substituents is, for example, a conjugated or non-conjugated fused ring formed between ^R1 and ^R2 , ^R2 and ^R3 , ^R3 and ^R4 , etc. These fused rings may contain a nitrogen, oxygen, or sulfur atom in the ring structure, and may be further fused with another ring.

However, preferably, when R ¹ and R ⁴ are phenyl, X and Y are not alkyl or phenyl. Also, preferably, when R ¹ and R ⁴ are thienyl groups, X and Y are not alkyl, and R ² and R ³ are not alkyl, aryl, alkenyl, or cycloalkyl in which R ² and R ³ are bonded to form a ring. Also, preferably, when R ¹ and R ⁴ are silyl groups, R ² , R ³ , X and Y are not each independently hydrogen or an alkyl having 1 to 6 carbon atoms. Also, preferably, when a benzene ring is condensed with R ¹ and R ² , X and Y are not alkyl or phenyl.

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

<Azoline derivatives>
The azoline derivative is, for example, a compound represented by the following formula (ETM-16). Details are described in WO 2017/014226.

In formula (ETM-16),
φ is an m-valent group derived from an aromatic hydrocarbon having 6 to 40 carbon atoms or an m-valent group derived from an aromatic heterocycle having 2 to 40 carbon atoms, and at least one hydrogen atom of φ is a hydrogen atom having 1 carbon atom. aryl having 6 to 18 carbon atoms, or heteroaryl having 2 to 18 carbon atoms;
Each Y is independently -O-, -S- or >N-Ar, Ar is an aryl having 6 to 12 carbon atoms or a heteroaryl having 2 to 12 carbon atoms, and at least one hydrogen atom of Ar is may be substituted with an alkyl having 1 to 4 carbon atoms, a cycloalkyl having 5 to 10 carbon atoms, an aryl having 6 to 12 carbon atoms, or a heteroaryl having 2 to 12 carbon atoms; R ¹ to R ⁵ are each independently and R 1 to R 5 in the >N-Ar group are each independently hydrogen, alkyl having 1 to 4 carbon atoms, or cycloalkyl having 5 to 10 carbon atoms, provided that any one of Ar and R ¹ to R ⁵ in the >N-Ar group is bonded to L. This is the part where
Each L is independently selected from the group consisting of a divalent group represented by the following formula (L-1) and a divalent group represented by the following formula (L-2):

In formula (L-1), X ¹ to X ⁶ are each independently =CR ⁶ - or =N-, at least two of X ¹ to X ⁶ are =CR ⁶ -, R ⁶ in two of X ¹ to X ⁶ =CR ⁶ - is φ or a bonding site to an azoline ring, and R ⁶ in the remaining =CR ⁶ - is hydrogen;
In formula (L-2), X ⁷ to X ¹⁴ each independently represent ═CR ⁶ — or ═N—, at least two of X ⁷ to X ¹⁴ represent ═CR ⁶ —, R ⁶ in two of X ⁷ to X ¹⁴ represent φ or a bonding site to an azoline ring, and R ⁶ in the remaining ═CR ⁶ — represents hydrogen ^;
At least one hydrogen atom of L may be substituted by alkyl having 1 to 4 carbon atoms, cycloalkyl having 5 to 10 carbon atoms, aryl having 6 to 10 carbon atoms, or heteroaryl having 2 to 10 carbon atoms;
m is an integer of 1 to 4, and when m is an integer of 2 to 4, the groups formed by the azoline ring and L may be the same or different, and
At least one hydrogen atom in the compound represented by formula (ETM-16) may be substituted with deuterium.

Specific azoline derivatives are compounds represented by the following formula (ETM-16-1) or (ETM-16-2).

In formula (ETM-16-1) and formula (ETM-16-2),
φ is an m-valent group derived from an aromatic hydrocarbon having 6 to 40 carbon atoms or an m-valent group derived from an aromatic heterocycle having 2 to 40 carbon atoms, and at least one hydrogen atom of φ is optionally substituted by an alkyl having 1 to 6 carbon atoms, a cycloalkyl having 3 to 14 carbon atoms, an aryl having 6 to 18 carbon atoms, or a heteroaryl having 2 to 18 carbon atoms;
In formula (ETM-16-1), each Y is independently -O-, -S-, or >N-Ar, Ar is an aryl having 6 to 12 carbon atoms or a heteroaryl having 2 to 12 carbon atoms, and at least one hydrogen atom of Ar is optionally substituted by an alkyl having 1 to 4 carbon atoms, a cycloalkyl having 5 to 10 carbon atoms, an aryl having 6 to 12 carbon atoms, or a heteroaryl having 2 to 12 carbon atoms,
In formula (ETM-16-1), R ¹ to R ⁴ each independently represent hydrogen, alkyl having 1 to 4 carbon atoms, or cycloalkyl having 5 to 10 carbon atoms, provided that R ¹ and R ² are the same, and R ³ and R ⁴ are the same;
In formula (ETM-16-2), R ¹ to R ⁵ each independently represent hydrogen, alkyl having 1 to 4 carbon atoms, or cycloalkyl having 5 to 10 carbon atoms, provided that R ¹ and R ² are the same, and R ³ and R ⁴ are the same;
In formula (ETM-16-1) and formula (ETM-16-2),
Each L is independently selected from the group consisting of a divalent group represented by the following formula (L-1) and a divalent group represented by the following formula (L-2):

式（Ｌ－１）中、Ｘ¹～Ｘ⁶はそれぞれ独立して＝ＣＲ⁶－または＝Ｎ－であり、Ｘ¹～Ｘ⁶のうちの少なくとも２つは＝ＣＲ⁶－であり、Ｘ¹～Ｘ⁶のうちの２つの＝ＣＲ⁶－におけるＲ⁶はφまたはアゾリン環と結合する部位であり、それ以外の＝ＣＲ⁶－におけるＲ⁶は水素であり、
式（Ｌ－２）中、Ｘ⁷～Ｘ¹⁴はそれぞれ独立して＝ＣＲ⁶－または＝Ｎ－であり、Ｘ⁷～Ｘ¹⁴のうちの少なくとも２つは＝ＣＲ⁶－であり、Ｘ⁷～Ｘ¹⁴のうちの２つの＝ＣＲ⁶－におけるＲ⁶はφまたはアゾリン環と結合する部位であり、それ以外の＝ＣＲ⁶－におけるＲ⁶は水素であり、
Ｌの少なくとも１つの水素は炭素数１～４のアルキル、炭素数５～１０のシクロアルキル、炭素数６～１０のアリールまたは炭素数２～１０のヘテロアリールで置換されていてもよく、
ｍは１～４の整数であり、ｍが２～４であるとき、アゾリン環とＬとで形成される基は同一であっても異なっていてもよく、そして、
式（ＥＴＭ－１６－１）または式（ＥＴＭ－１６－２）で表される化合物中の少なくとも１つの水素は重水素で置換されていてもよい。

In formula (L-1), X ¹ to X ⁶ are each independently =CR ⁶ - or =N-, at least two of X ¹ to X ⁶ are =CR ⁶ -, R ⁶ in two of X ¹ to X ⁶ =CR ⁶ - is φ or a bonding site to an azoline ring, and R ⁶ in the remaining =CR ⁶ - is hydrogen;
In formula (L-2), X ⁷ to X ¹⁴ each independently represent ═CR ⁶ — or ═N—, at least two of X ⁷ to X ¹⁴ represent ═CR ⁶ —, R ⁶ in two of X ⁷ to X ¹⁴ represent φ or a bonding site to an azoline ring, and R ⁶ in the remaining ═CR ⁶ — represents hydrogen ^;
At least one hydrogen atom of L may be substituted by alkyl having 1 to 4 carbon atoms, cycloalkyl having 5 to 10 carbon atoms, aryl having 6 to 10 carbon atoms, or heteroaryl having 2 to 10 carbon atoms;
m is an integer of 1 to 4, and when m is an integer of 2 to 4, the groups formed by the azoline ring and L may be the same or different, and
At least one hydrogen atom in the compound represented by formula (ETM-16-1) or formula (ETM-16-2) may be substituted with deuterium.

Preferably, φ is selected from the group consisting of monovalent groups represented by the following formulas (φ1-1) to (φ1-18), divalent groups represented by the following formulas (φ2-1) to (φ2-34), trivalent groups represented by the following formulas (φ3-1) to (φ3-3), and tetravalent groups represented by the following formulas (φ4-1) to (φ4-2), and at least one hydrogen of φ may be substituted with an alkyl having 1 to 6 carbon atoms, a cycloalkyl having 3 to 14 carbon atoms, an aryl having 6 to 18 carbon atoms, or a heteroaryl having 2 to 18 carbon atoms.

In the formula, Z is >CR ₂ , >N-Ar, >N-L, -O- or -S-, each R in >CR ₂ is independently an alkyl having 1 to 4 carbon atoms, a cycloalkyl having 5 to 10 carbon atoms, an aryl having 6 to 12 carbon atoms or a heteroaryl having 2 to 12 carbon atoms, and the Rs may be bonded to each other to form a ring, Ar in >N-Ar is an aryl having 6 to 12 carbon atoms or a heteroaryl having 2 to 12 carbon atoms, and L in >N-L is L in formula (ETM-16), formula (ETM-16-1) or formula (ETM-16-2). * in the formula represents a bonding position.

Preferably, L is a divalent ring group selected from the group consisting of benzene, naphthalene, pyridine, pyrazine, pyrimidine, pyridazine, triazine, quinoline, isoquinoline, naphthyridine, phthalazine, quinoxaline, quinazoline, cinnoline, and pteridine, and at least one hydrogen of L may be substituted with an alkyl having 1 to 4 carbon atoms, a cycloalkyl having 5 to 10 carbon atoms, an aryl having 6 to 10 carbon atoms, or a heteroaryl having 2 to 10 carbon atoms.

Preferably, Ar in >N-Ar as Y or Z is selected from the group consisting of phenyl, naphthyl, pyridinyl, pyrazinyl, pyrimidinyl, pyridazinyl, triazinyl, quinolinyl, isoquinolinyl, naphthyridinyl, phthalazinyl, quinoxalinyl, quinazolinyl, cinnolinyl, and pteridinyl, and at least one hydrogen of Ar in >N-Ar as Y may be substituted with alkyl having 1 to 4 carbon atoms, cycloalkyl having 5 to 10 carbon atoms, or aryl having 6 to 10 carbon atoms.

Preferably, R ¹ to R ⁴ are each independently hydrogen, alkyl having 1 to 4 carbon atoms, or cycloalkyl having 5 to 10 carbon atoms, with the proviso that R ¹ and R ² are the same, R ³ and R ⁴ are the same, and R ¹ to R ⁴ are not all hydrogen at the same time, and m is 1 or 2, and when m is 2, the groups formed by the azoline ring and L are the same.

Specific examples of azoline derivatives include the following compounds: In the structural formula, "Me" represents methyl.

More preferably, φ is selected from the group consisting of divalent groups represented by the following formulas (φ2-1), (φ2-31), (φ2-32), (φ2-33) and (φ2-34), and at least one hydrogen of φ may be substituted with an aryl having 6 to 18 carbon atoms.

L is a divalent ring group selected from the group consisting of benzene, pyridine, pyrazine, pyrimidine, pyridazine, and triazine, and at least one hydrogen of L is optionally substituted by alkyl having 1 to 4 carbon atoms, cycloalkyl having 5 to 10 carbon atoms, aryl having 6 to 10 carbon atoms, or heteroaryl having 2 to 14 carbon atoms;
Ar in >N-Ar as Y is selected from the group consisting of phenyl, pyridinyl, pyrazinyl, pyrimidinyl, pyridazinyl, and triazinyl, and at least one hydrogen of the Ar may be substituted with alkyl having 1 to 4 carbon atoms, cycloalkyl having 5 to 10 carbon atoms, or aryl having 6 to 10 carbon atoms;
R ¹ to R ⁴ are each independently hydrogen, alkyl having 1 to 4 carbon atoms, or cycloalkyl having 5 to 10 carbon atoms, provided that R ¹ and R ² are the same, R ³ and R ⁴ are the same, and R ¹ to R ⁴ are not all hydrogen at the same time, and
m is 2, and the groups formed by the azoline ring and L are the same.

Other specific examples of the azoline derivative include the following compounds: In the structural formula, "Me" represents methyl.

For details of the alkyl, cycloalkyl, aryl, or heteroaryl in the above formulas defining this azoline derivative, the explanations in formula (1A) and formula (1B) can be cited.

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

<Reducing Substance>
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, and 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 suitably 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.

The above-mentioned electron injection layer material and electron transport layer material can be used as an electron layer material in the form of a polymer compound obtained by polymerizing a reactive compound substituted with a reactive substituent as a monomer, or a crosslinked polymer thereof, or a pendant polymer compound obtained by reacting a main chain polymer with the reactive compound, or a crosslinked pendant polymer thereof. In this case, the reactive substituent can be quoted from the description of the polycyclic aromatic compound having a partial structure represented by formula (1A) and at least one partial structure represented by formula (1B).
The applications of such polymer compounds and crosslinked polymers will be described in detail below.

3-1-7. Cathode in Organic Electroluminescent Device The cathode 108 plays a role in injecting 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.

3-1-8. Binders that may be used in each layer The materials used in the hole injection layer, hole transport layer, light emitting layer, electron transport layer and electron injection layer described above can form each layer alone, but they can also be used as polymer binders by dispersing them in solvent-soluble resins such as polyvinyl chloride, polycarbonate, polystyrene, poly(N-vinylcarbazole), polymethyl methacrylate, polybutyl methacrylate, polyester, polysulfone, polyphenylene oxide, polybutadiene, hydrocarbon resins, ketone resins, phenoxy resins, polyamide, ethyl cellulose, vinyl acetate resins, ABS resins and polyurethane resins, and curable resins such as phenol resins, xylene resins, petroleum resins, urea resins, melamine resins, unsaturated polyester resins, alkyd resins, epoxy resins and silicone resins.

3-1-9. Method for Producing an Organic Electroluminescent Device Each layer constituting an organic EL device 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 desired crystal structure and association structure of the film, etc. The vapor deposition conditions are generally preferably set appropriately within the range of boat heating temperature +50 to +400°C, vacuum degree 10 ^-6 to 10 ^-3 Pa, vapor deposition speed 0.01 to 50 nm/sec, substrate temperature -150 to +300°C, and film thickness 2 nm to 5 μm.

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.

Next, as an example of a method for producing an organic EL element, we will explain a method for producing an organic EL element consisting of an anode, a hole injection layer, a hole transport layer, a light emitting layer made of a host material and a dopant material, an electron transport layer, an electron injection layer, and a cathode.

<Vapor deposition method>
A thin film of an anode material is formed on a suitable substrate by vapor deposition or the like to prepare an anode, and then a thin film of a hole injection layer and a hole transport layer is formed on the anode. A host material and a dopant material are co-deposited on the anode to form a thin film as 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 vapor deposition or the like to prepare a cathode, thereby obtaining a desired organic EL element. Note that in the preparation of the above-mentioned organic EL element, the order of preparation can be reversed, and the elements can be prepared in the order of cathode, electron injection layer, electron transport layer, light-emitting layer, hole transport layer, hole injection layer, and anode.

<Wet film formation method>
The wet film formation method is carried out by preparing a low molecular weight compound capable of forming each organic layer of an organic EL element as a liquid composition for forming an organic layer, and using this. If there is no suitable organic solvent for dissolving this low molecular weight compound, the composition for forming an organic layer may be prepared from a polymer compound polymerized together with other monomers having a solubility function as a reactive compound in which the low molecular weight compound is substituted with a reactive substituent, or a main chain polymer.

In wet film formation, a coating film is generally formed through a coating step in which an organic layer-forming composition is applied to a substrate and a drying step in which the solvent is removed from the applied organic layer-forming composition. When the polymer compound has a crosslinkable substituent (also called a crosslinkable polymer compound), the polymer is further crosslinked by the drying step to form a crosslinked polymer. Depending on the coating step, a method using a spin coater is called a spin coat method, a method using a slit coater is called a slit coat method, a method using a plate is called a gravure, offset, reverse offset, or flexographic printing method, a method using an inkjet printer is called an inkjet method, and a method spraying in a mist is called a spray method.

As an example, referring to FIG. 2, a method of forming a coating film on a substrate having a bank using an inkjet method will be described. First, the bank (200) is provided on the electrode (120) on the substrate (110). In this case, ink droplets (310) are dropped between the banks (200) from the inkjet head (300) and dried to produce the coating film (130). This process is repeated to produce the next coating film (140) and then the light-emitting layer (150), and an electron transport layer, an electron injection layer, and electrodes are formed using a vacuum deposition method, making it possible to produce an organic EL element in which the light-emitting region is separated by the bank material.

The drying process can be carried out by air drying, heating, drying under reduced pressure, etc. The drying process can be carried out once, or multiple times using different methods and conditions. Also, different methods can be used in combination, such as baking under reduced pressure.

A wet film formation method is a film formation method that uses a solution, and examples of this include some printing methods (inkjet methods), spin coating methods or casting methods, and coating methods. Unlike vacuum deposition methods, wet film formation methods do not require expensive vacuum deposition equipment, and can form films under atmospheric pressure. In addition, wet film formation methods allow for large area production and continuous production, which leads to reduced manufacturing costs.

On the other hand, compared to the vacuum deposition method, wet deposition methods can be difficult to layer. When using wet deposition methods to create layered films, it is necessary to prevent the lower layer from being dissolved by the composition of the upper layer, and therefore compositions with controlled solubility, crosslinking of the lower layer, and orthogonal solvents (solvents that are not mutually soluble) are used. However, even with these techniques, it can be difficult to use wet deposition methods to apply all films.

Therefore, a common method for producing organic EL elements is to use wet deposition methods for only a few layers and vacuum deposition for the rest.

For example, the procedure for producing an organic EL element by partially applying a wet film formation method will be described below.
(Step 1) Formation of an anode by vacuum deposition (Step 2) Formation of a hole injection layer-forming composition containing a hole injection layer material by wet deposition (Step 3) Formation of a hole transport layer-forming composition containing a hole transport layer material by wet deposition (Step 4) Formation of an emitting layer-forming composition containing a host material and a dopant material by wet deposition (Step 5) Formation of an electron transport layer by vacuum deposition (Step 6) Formation of an electron injection layer by vacuum deposition (Step 7) Formation of a cathode by vacuum deposition By going through these steps, an organic EL element consisting of an anode/hole injection layer/hole transport layer/emitting layer consisting of a host material and a dopant material/electron transport layer/electron injection layer/cathode is obtained.
Of course, if there is a means for preventing dissolution of the lower light-emitting layer, or if a means for forming a film from the cathode side is used in the opposite procedure to the above, a layer-forming composition containing a material for the electron transport layer and a material for the electron injection layer can be prepared and then the layer can be formed by a wet film formation method.

<Other film formation methods>
The composition for forming an organic layer can be formed into a film by laser thermal imaging (LITI). LITI is a method in which a compound attached to a substrate is heated and vapor-deposited by a laser, and the composition for forming an organic layer can be used as a material to be applied to the substrate.

<Optional Step>
Before and after each film-forming step, appropriate treatment steps, cleaning steps, and drying steps may be appropriately inserted. Examples of treatment steps include exposure treatment, plasma surface treatment, ultrasonic treatment, ozone treatment, cleaning treatment using an appropriate solvent, and heat treatment. Furthermore, a series of steps for preparing a bank may also be included.

Photolithography techniques can be used to fabricate the bank. Positive resist materials and negative resist materials can be used as bank materials that can be used with photolithography. In addition, patternable printing methods such as inkjet printing, gravure offset printing, reverse offset printing, and screen printing can also be used. In this case, permanent resist materials can also be used.

Materials that can be used for the bank include, but are not limited to, polysaccharides and their derivatives, homopolymers and copolymers of hydroxyl-containing ethylenic monomers, biopolymers, polyacryloyl compounds, polyesters, polystyrenes, polyimides, polyamideimides, polyetherimides, polysulfides, polysulfones, polyphenylenes, polyphenyl ethers, polyurethanes, epoxy (meth)acrylates, melamine (meth)acrylates, polyolefins, cyclic polyolefins, acrylonitrile-butadiene-styrene copolymers (ABS), silicone resins, polyvinyl chloride, chlorinated polyethylene, chlorinated polypropylene, polyacetates, polynorbornenes, synthetic rubbers, fluorinated polymers such as polyfluorovinylidene, polytetrafluoroethylene, and polyhexafluoropropylene, copolymers of fluoroolefins and hydrocarbon olefins, and fluorocarbon polymers.

<Organic layer forming composition used in wet film formation method>
The composition for forming an organic layer is obtained by dissolving a low molecular weight compound capable of forming each organic layer of an organic EL element, or a polymer compound obtained by polymerizing the low molecular weight compound, in an organic solvent. For example, the composition for forming an emitting layer contains at least one polycyclic aromatic compound (or a polymer compound thereof) as a first component, which is a dopant material, at least one host material as a second component, and at least one organic solvent as a third component. The first component functions as a dopant component of the emitting layer obtained from the composition, and the second component functions as a host component of the emitting layer. The third component functions as a solvent that dissolves the first and second components in the composition, and gives a smooth and uniform surface shape due to the controlled evaporation rate of the third component itself during application.

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

(1) Physical properties of organic solvent The boiling point of at least one organic solvent is 130°C to 300°C, more preferably 140°C to 270°C, and even more preferably 150°C to 250°C. When the boiling point is higher than 130°C, it is preferable from the viewpoint of inkjet dischargeability. Also, when the boiling point is lower than 300°C, it is preferable from the viewpoint of defects, surface roughness, residual solvent, and smoothness of the coating film. From the viewpoint of good inkjet dischargeability, film-forming property, smoothness, and low residual solvent, it is more preferable that the organic solvent contains two or more organic solvents. On the other hand, in some cases, the composition may be a solid state composition obtained by removing the solvent from the composition for forming the organic layer, taking into consideration transportability and the like.

Furthermore, it is particularly preferable that the organic solvent contains a good solvent (GS) and a poor solvent (PS) for at least one type of solute, and the boiling point (BP _GS ) of the good solvent (GS) is lower than the boiling point (BP _PS ) of the poor solvent (PS).
By adding a poor solvent with a high boiling point, the good solvent with a low boiling point volatilizes first during film formation, increasing the concentration of the components in the composition and the concentration of the poor solvent, promoting rapid film formation. This results in a coating film with few defects, small surface roughness, and high smoothness.

The difference in solubility (S _GS -S _PS ) is preferably 1% or more, more preferably 3% or more, and even more preferably 5% or more. The difference in boiling point (BP _PS -BP _GS ) is preferably 10°C or more, more preferably 30°C or more, and even more preferably 50°C or more.

After the film is formed, the organic solvent is removed from the coating film by a drying process such as vacuum, reduced pressure, or heating. When heating is performed, from the viewpoint of improving the coating film-forming properties, it is preferable to perform the heating at a temperature of at least one of the solutes' glass transition temperature (Tg) +30°C or lower. From the viewpoint of reducing residual solvent, it is preferable to heat at at least one of the solutes' glass transition temperature (Tg) -30°C or higher. Even if the heating temperature is lower than the boiling point of the organic solvent, the organic solvent is sufficiently removed because the film is thin. Also, drying may be performed multiple times at different temperatures, and multiple drying methods may be used in combination.

(2) Specific Examples of Organic Solvents Examples of organic solvents used in the composition for forming an organic layer include alkylbenzene solvents, phenyl ether solvents, alkyl ether solvents, cyclic ketone solvents, aliphatic ketone solvents, monocyclic ketone solvents, solvents having a diester skeleton, and fluorine-containing solvents. Specific examples include pentanol, hexanol, heptanol, octanol, nonanol, decanol, undecanol, dodecanol, tetradecanol, hexane-2-ol, heptan-2-ol, octan-2-ol, decan-2-ol, dodecan-2-ol, cyclohexanol, α-terpineol, β-terpineol, γ-terpineol, δ-terpineol, terpineol (mixture), ethylene glycol monomethyl ether acetate, propylene glycol monomethyl ether acetate, diethylene glycol dimethyl ether, dipropylene glycol dimethyl ether, diethylene glycol ethyl methyl ether, ethylene glycol ethyl ... ether, diethylene glycol isopropyl methyl ether, dipropylene glycol monomethyl ether, diethylene glycol diethyl ether, diethylene glycol monomethyl ether, diethylene glycol butyl methyl ether, tripropylene glycol dimethyl ether, triethylene glycol dimethyl ether, diethylene glycol monobutyl ether, ethylene glycol monophenyl ether, triethylene glycol monomethyl ether, diethylene glycol dibutyl ether, triethylene glycol butyl methyl ether, polyethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, p-xylene, m-xylene, o-xylene, 2,6-lutidine, 2-fluoro-m-xylene, 3-fluoro-o-xylene, 2-chlorobenzotrifluoride, cumene, toluene, 2-chloro-6-fluorotoluene, 2-fluoroanisole, anisole, 2,3-Dimethylpyrazine, Bromobenzene, 4-Fluoroanisole, 3-Fluoroanisole, 3-Trifluoromethylanisole, Mesitylene, 1,2,4-Trimethylbenzene, t-Butylbenzene, 2-Methylanisole, Phenetole, Benzodioxole, 4-Methylanisole, s-Butylbenzene, 3-Methylanisole, 4-Fluoro-3-methylanisole, Cymene, 1,2,3-Trimethylbenzene, 1,2-Dichlorobenzene, 2-Fluorobenzonitrile, 4-Fluoroveratrol, 2,6-Dimethylanisole, n-Butylbenzene, 3-Fluorobenzonitrile, Decalin (Decahydronaphthalene), Neopentylbenzene, 2,5-Dimethylanisole, 2,4-Dimethylanisole, Benzonitrile, 3,5-Dimethylanisole, Diphenyl ether, 1-Fluoro-3,5-dimethoxybenzene, Methyl benzoate, Isopentylbenzene, 3,4-Dimethylanisole , o-tolunitrile, n-amylbenzene, veratrole, 1,2,3,4-tetrahydronaphthalene, ethyl benzoate, n-hexylbenzene, propyl benzoate, cyclohexylbenzene, 1-methylnaphthalene, butyl benzoate, 2-methylbiphenyl, 3-phenoxytoluene, 2,2'-bitolyl, dodecylbenzene, dipentylbenzene, tetramethylbenzene, trimethoxybenzene, trimethoxytoluene, 2,3-dihydrobenzofuran, 1-methyl-4-(propoxymethyl)benzene, 1-methyl-4-(butyloxymethyl)benzene, 1-methyl-4-(pentyloxymethyl)benzene, 1-methyl-4-(hexyloxymethyl)benzene, 1-methyl-4-(heptyloxymethyl)benzene, benzyl butyl ether, benzyl pentyl ether, benzyl hexyl ether, benzyl heptyl ether, benzyl octyl ether, etc., but are not limited thereto. In addition, the solvent may be used alone or may be mixed.

<Optional ingredients>
The composition for forming the organic layer may contain optional components, such as a binder and a surfactant, to the extent that the properties of the composition are not impaired.

(1) Binder The composition for forming an organic layer may contain a binder. The binder forms a film during film formation and bonds the resulting film to a substrate. The binder also plays a role in dissolving, dispersing, and binding other components in the composition for forming an organic layer.

Examples of binders used in the organic layer forming composition include, but are not limited to, acrylic resins, polyethylene terephthalate, ethylene-vinyl acetate copolymers, ethylene-vinyl alcohol copolymers, acrylonitrile-ethylene-styrene copolymer (AES) resins, ionomers, chlorinated polyethers, diallyl phthalate resins, unsaturated polyester resins, polyethylene, polypropylene, polyvinyl chloride, polyvinylidene chloride, polystyrene, polyvinyl acetate, Teflon, acrylonitrile-butadiene-styrene copolymer (ABS) resins, acrylonitrile-styrene copolymer (AS) resins, phenolic resins, epoxy resins, melamine resins, urea resins, alkyd resins, polyurethanes, and copolymers of the above resins and polymers.

The binder used in the composition for forming the organic layer may be of one type or a mixture of multiple types.

(2) Surfactant The organic layer forming composition may contain a surfactant, for example, to control the film surface uniformity, solvent affinity and liquid repellency of the organic layer forming composition. Surfactants are classified into ionic and nonionic based on the structure of the hydrophilic group, and further classified into alkyl, silicon and fluorine based based on the structure of the hydrophobic group. In addition, based on the molecular structure, they are classified into monomolecular systems with relatively small molecular weight and simple structure, and polymer systems with large molecular weight and side chains or branches. In addition, based on the composition, they are classified into single systems and mixed systems in which two or more types of surfactants and base materials are mixed. All types of surfactants can be used as surfactants that can be used in the organic layer forming composition.

Examples of surfactants include Polyflow No. 45, Polyflow KL-245, Polyflow No. 75, Polyflow No. 90, Polyflow No. 95 (trade names, manufactured by Kyoeisha Chemical Industry Co., Ltd.), Disperbake 161, Disperbake 162, Disperbake 163, Disperbake 164, Disperbake 166, Disperbake 170, Disperbake 180, Disperbake 181, Disperbake 182, BYK300, BYK306, BYK310, BYK320, BYK330, BYK342, B YK344, BYK346 (product names, manufactured by BYK Japan Co., Ltd.), KP-341, KP-358, KP-368, KF-96-50CS, KF-50-100CS (product names, manufactured by Shin-Etsu Chemical Co., Ltd.), Surflon SC-101, Surflon KH-40 (product names, manufactured by Seimi Chemical Co., Ltd.), Ftergent 222F, Ftergent 251, FTX-218 (product names, manufactured by Neos Co., Ltd.), EFTOP EF-351, EFTOP EF-352, EFTOP EF-601, EFTOP EF-801, EFTOP EF-802 (product name, manufactured by Mitsubishi Materials Corporation), Megafac F-470, Megafac F-471, Megafac F-475, Megafac R-08, Megafac F-477, Megafac F-479, Megafac F-553, Megafac F-554 (product name, manufactured by DIC Corporation), fluoroalkylbenzenesulfonate, fluoroalkylcarboxylate, fluoroalkylpolyoxyethyleneether, fluoroalkylammonium iodide, fluoroalkylbetaine, fluoroalkylsulfonate, diglycerol tetrakis (fluoroalkylpolyoxyethyleneether), fluoroalkyltrimethylammonium salt, fluoroalkylaminosulfonate, polyoxyethylenenonyl Examples of such sorbitan fatty acid esters include sorbitan laurate, polyoxyethylene sorbitan palmitate, polyoxyethylene sorbitan stearate, polyoxyethylene sorbitan oleate, sorbitan fatty acid esters, polyoxyethylene sorbitan laurate, polyoxyethylene sorbitan palmitate, polyoxyethylene sorbitan stearate, polyoxyethylene sorbitan oleate, polyoxyethylene naphthyl ether, alkylbenzene sulfonate, and alkyldiphenyl ether disulfonate.

The surfactant may be used alone or in combination with two or more types.

<Composition and Properties of Organic Layer-Forming Composition>
The content of each component in the composition for forming an organic layer is determined in consideration of the good solubility, storage stability and film-forming property of each component in the composition for forming an organic layer, the good film quality of the coating film obtained from the composition for forming an organic layer, the good discharge property when using an ink jet method, and the good electrical properties, light-emitting properties, efficiency and life of an organic EL element having an organic layer produced using the composition. For example, in the case of a composition for forming an emitting layer, it is preferable that the first component is 0.0001% by mass to 2.0% by mass with respect to the total mass of the composition for forming an emitting layer, the second component is 0.0999% by mass to 8.0% by mass with respect to the total mass of the composition for forming an emitting layer, and the third component is 90.0% by mass to 99.9% by mass with respect to the total mass of the composition for forming an emitting layer.

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

The composition for forming the organic layer can be produced by appropriately selecting and carrying out stirring, mixing, heating, cooling, dissolving, dispersing, etc. of the above-mentioned components using a known method. In addition, after preparation, filtration, degassing (also called degassing), ion exchange treatment, and inert gas replacement/filling treatment, etc. may be appropriately selected and carried out.

The higher the viscosity of the composition for forming the organic layer, the better the film-forming properties and the better the ejection properties when using the inkjet method. On the other hand, the lower the viscosity, the easier it is to form a thin film. For this reason, the viscosity of the composition for forming the organic layer at 25°C is preferably 0.3 to 3 mPa·s, and more preferably 1 to 3 mPa·s. In the present invention, the viscosity is a value measured using a cone-plate type rotational viscometer (cone-plate type).

The lower the surface tension of the composition for forming the organic layer, the better the film-forming properties and the more defect-free the coating film will be. On the other hand, the higher the surface tension, the better the ink-jet ejection properties will be. For this reason, the viscosity of the composition for forming the organic layer is preferably such that the surface tension at 25°C is 20 to 40 mN/m, and more preferably 20 to 30 mN/m. In the present invention, the surface tension is a value measured using the hanging drop method.

<Crosslinkable polymer compound: compound represented by formula (XLP-1)>
Next, the case where the above-mentioned polymer compound has a crosslinkable substituent will be described. Such a crosslinkable polymer compound is, for example, a compound represented by the following formula (XLP-1).

In formula (XLP-1),
MUx, ECx, and k are defined the same as MU, EC, and k in formula (SPH-1), with the proviso that the compound represented by formula (XLP-1) has at least one crosslinkable substituent (XLS), and preferably the content of the monovalent or divalent aromatic group having a crosslinkable substituent is 0.1 to 80 mass% in the molecule.

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

The crosslinkable substituent (XLS) is not particularly limited as long as it is a group that can further crosslink the above-mentioned polymer compound, but substituents having the following structures are preferred: In each structural formula, * indicates a bond position.

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

Examples of the divalent aromatic compound having a crosslinkable substituent include compounds having the following partial structures:

<Method of producing polymer compound and crosslinkable polymer compound>
The methods for producing the polymer compound and the crosslinkable polymer compound will be described below with reference to the compound represented by the above formula (SPH-1) and the compound represented by the above formula (XLP-1). These compounds can be synthesized by appropriately combining known production methods.

Solvents used in the reaction include aromatic solvents, saturated/unsaturated hydrocarbon solvents, alcohol solvents, and ether solvents, such as dimethoxyethane, 2-(2-methoxyethoxy)ethane, and 2-(2-ethoxyethoxy)ethane.

The reaction may also be carried out in a two-phase system. When carrying out the reaction in a two-phase system, a phase transfer catalyst such as a quaternary ammonium salt may be added as necessary.

The compound of formula (SPH-1) and the compound of formula (XLP-1) may be produced in one step or in multiple steps. The compound may be produced by a batch polymerization method in which all the raw materials are put into a reaction vessel and then the reaction is started, a dropwise polymerization method in which the raw materials are added dropwise to a reaction vessel, or a precipitation polymerization method in which the product precipitates as the reaction proceeds. These methods can be combined appropriately to synthesize the compound. For example, when the compound represented by formula (SPH-1) is synthesized in one step, the target product is obtained by adding a monomer having a polymerizable group bonded to the monomer unit (MU) and a monomer having a polymerizable group bonded to the end cap unit (EC) to a reaction vessel and then reacting the monomer. When the compound represented by formula (SPH-1) is synthesized in multiple steps, the target product is obtained by polymerizing the monomer having a polymerizable group bonded to the monomer unit (MU) to the target molecular weight, and then adding and reacting a monomer having a polymerizable group bonded to the end cap unit (EC). By adding monomers with polymerizable groups bonded to different types of monomer units (MU) in multiple stages and carrying out a reaction, it is possible to create a polymer with a concentration gradient in the monomer unit structure. In addition, after preparing a precursor polymer, the target polymer can be obtained by further reaction.

In addition, the primary structure of the polymer can be controlled by selecting the polymerizable group of the monomer. For example, as shown in synthesis schemes 1 to 3, it is possible to synthesize a polymer with a random primary structure (synthetic scheme 1) or a polymer with a regular primary structure (synthetic schemes 2 and 3), and these can be used in appropriate combinations depending on the intended purpose. Furthermore, if a monomer with three or more polymerizable groups is used, a hyperbranched polymer or dendrimer can be synthesized.

Monomers that can be used in the present invention include those described in JP 2010-189630 A, WO 2012/086671 A, WO 2013/191088 A, WO 2002/045184 A, WO 2011/049241 A, WO 2013/146806 A, WO 2005/049546 A, and WO 2015/14587 A. It can be synthesized in accordance with the methods described in JP-A-2002/045184, JP-A-2010-215886, JP-A-2008-106241, JP-A-2010-215886, WO 2016/031639, JP-A-2011-174062, WO 2016/031639, WO 2016/031639, and WO 2002/045184.

Specific polymer synthesis procedures are described in JP 2012-036388 A, WO 2015/008851 A, JP 2012-36381 A, JP 2012-144722 A, WO 2015/194448 A, WO 2013/146806 A, WO 2015/145871 A, WO 2016/ It can be synthesized in accordance with the methods described in International Publication No. 2016/125560, International Publication No. 2016/031639, International Publication No. 2016/031639, International Publication No. 2016/125560, International Publication No. 2015/145871, International Publication No. 2011/049241, and JP 2012-144722 A.

3-1-10. Application Examples of Organic Electroluminescent Devices The present invention can also be applied to display devices including organic EL devices or lighting devices including organic EL devices.
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/or 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-A-2003-257621, JP-A-2003-277741, JP-A-2004-119211, 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): Compound (1-161)

3.24 g (2.5 mmol) of compound (Int-1-161) was placed in a reaction vessel, and after replacing with nitrogen, 20 mL of 1,2-dichlorobenzene was added. 3.13 g of boron tribromide (BBr ₃ ) was added dropwise from a dropping funnel, and refluxed at 145° C. for 4.5 hours. The reaction was stopped with an aqueous sodium acetate solution, and extracted with dichloromethane. The residue obtained by distilling off the solvent was purified by silica gel short column chromatography (eluent: toluene). Compound (1-161) was obtained by heating and refluxing and washing with heptane (1.02 g, yield 31%).
The target compound (1-161) was confirmed to have an m/z value of 1311.73 by LC-MS.

Synthesis example (2): Compound (1-180)

2.98 g (2.5 mmol) of compound (Int-1-180) was placed in a reaction vessel, and after replacing with nitrogen, 20 mL of 1,2-dichlorobenzene was added. 3.13 g of boron tribromide (BBr ₃ ) was added dropwise from a dropping funnel, and refluxed at 145° C. for 12 hours. The reaction was stopped with an aqueous sodium acetate solution, and extracted with dichloromethane. The residue obtained by distilling off the solvent was purified by silica gel short column chromatography (eluent: toluene/heptane = 1/1 (volume ratio)). Compound (1-180) was obtained by heating and refluxing washing with heptane (0.75 g, yield 25%).
The target compound (1-180) was confirmed to have an m/z value of 1207.65 by LC-MS.

Synthesis example (3): Compound (1-256)

2.56 g (2.5 mmol) of compound (Int-1-256) was placed in a reaction vessel, and after replacing with nitrogen, 20 mL of 1,2-dichlorobenzene was added. 3.13 g of boron tribromide (BBr ₃ ) was added dropwise from a dropping funnel, and refluxed at 145° C. for 14 hours. The reaction was stopped with an aqueous sodium acetate solution, and extracted with dichloromethane. The residue obtained by distilling off the solvent was purified by silica gel short column chromatography (eluent: toluene). Compound (1-256) was obtained by heating and refluxing and washing with heptane (0.38 g, yield 14%).
The target compound (1-256) was confirmed to be present at m/z=1076.61 by LC-MS.

Next, we will describe the evaluation of the basic physical properties of the compound of the present invention and the fabrication and evaluation of an organic EL device using the compound of the present invention.

(1) Preparation and evaluation of deposition type organic EL element Organic EL elements according to the examples and comparative examples are prepared, and voltage is applied to measure current density, luminance, chromaticity, external quantum efficiency, etc. As the configuration of the prepared organic EL element, the following configuration A (Table 1) and configuration B (Table 2) are selected and evaluated. However, application of the compound of the present invention is not limited to these configurations, and the film thickness and constituent materials of each layer can be appropriately changed depending on the basic physical properties of the compound of the present invention.

<<Element configuration and evaluation of configuration A>>

In Table 1,
"NPD" is N,N'-diphenyl-N,N'-dinaphthyl-4,4'-diaminobiphenyl;
"TcTa" is 4,4',4"-tris(N-carbazolyl)triphenylamine;
"mCP" is 1,3-bis(N-carbazolyl)benzene;
"2CzBN" is 3,4-dicarbazolylbenzonitrile and "BPy-TP2" is 2,7-di([2,2'-bipyridin]-5-yl)triphenylene.
The chemical structures of "BH-1", "RBD-1", "RBD-2" and "RBD-3" are shown below.

Example 1
<Constitution A: Element Using Compound (1-161) as a Dopant>
A 26 mm × 28 mm × 0.7 mm glass substrate (manufactured by Optoscience Co., Ltd.) on which an ITO film having a thickness of 200 nm was formed by sputtering and polished to 50 nm was used as a transparent support substrate. This transparent support substrate was fixed to a substrate holder of a commercially available deposition apparatus (manufactured by Showa Vacuum Co., Ltd.), and a molybdenum deposition boat containing NPD, TcTa, mCP, BH-1, compound (1-161), 2CzBN, and BPy-TP2, and a tungsten deposition boat containing LiF and aluminum were 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, NPD was heated and evaporated to a thickness of 40 nm to form a hole injection layer. Next, TcTa was heated and evaporated to a thickness of 15 nm to form a hole transport layer. Next, mCP was heated and evaporated to a thickness of 15 nm to form an electron blocking layer. Next, BH-1 and compound (1-161) were heated simultaneously and evaporated to a thickness of 20 nm to form a light emitting layer. The evaporation rate was adjusted so that the weight ratio of BH-1 to compound (1-161) was approximately 99:1. Next, 2CzBN was heated and evaporated to a thickness of 10 nm, and then BPy-TP2 was heated and evaporated to a thickness of 20 nm to form an electron transport layer consisting of two layers. The evaporation rate of each layer was 0.01 to 1 nm/sec. Thereafter, 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 of aluminum was adjusted to 1 to 10 nm/sec.

<Examples 2 and 3, Comparative Examples 1 to 3>
The compound (1-161) used as the dopant in Example 1 was changed to a dopant shown in Table 1 to prepare a device.

<Evaluation>
The fabricated element was subjected to DC voltage application with the ITO electrode as the anode and the aluminum electrode as the cathode, and the emission wavelength, half-width, driving voltage, current density, external quantum efficiency (EQE), and LT50 (the time to reach 250 cd/ ^m2 when continuously driven at a current density at an initial luminance of 500 cd/ ^m2 ) at a luminance of 500 cd/ ^m2 were measured. The evaluation results are shown in Table 1.

<<Element configuration and evaluation of configuration B>>

In Table 2,
"HI-1" 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, and "HT-2" is N,N-bis(4-(dibenzo[b,d]furan-4-yl)phenyl)-[1,1':4',1"-terphenyl]-4-amine;
"BH-2" is 9-phenyl-10-(4-phenylnaphthalen-1-yl)anthracene;
"BH-3" is 2-(10-phenylanthracen-9-yl)dibenzo[b,d]furan and "ET-1" is 4,6,8,10-tetraphenyl[1,4]benzoxaborinino[2,3,4-kl]phenoxaborinine;
"ET-2" is 3,3'-((2-phenylanthracene-9,10-diyl)bis(4,1-phenylene))bis(4-methylpyridine),
The chemical structure is shown below along with "Liq."

Example 4
<Configuration B: Element using compound (1-256) as a dopant>
A 26 mm x 28 mm x 0.7 mm glass substrate (manufactured by Optoscience Co., Ltd.) on which an ITO film having a thickness of 200 nm was formed by sputtering and polished to 50 nm was used as a transparent support substrate. This transparent support substrate was fixed to a substrate holder of a commercially available deposition apparatus (manufactured by Showa Vacuum Co., Ltd.), and a molybdenum deposition boat containing HI-1, HAT-CN, HT-1, HT-2, BH-2, compound (1-256), ET-1, ET-2, and Liq, and a tungsten deposition boat containing LiF and aluminum were 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-1 was heated and evaporated to a thickness of 40 nm, and HAT-CN was further heated and evaporated to a thickness of 5 nm to form a hole injection layer consisting of two layers. Next, HT-1 was heated and evaporated to a thickness of 15 nm, and HT-2 was further heated and evaporated to a thickness of 10 nm to form a hole transport layer consisting of two layers. Next, BH-2 and compound (1-256) were simultaneously heated and evaporated to a thickness of 25 nm to form a light-emitting layer. The evaporation rate was adjusted so that the weight ratio of BH-2 to compound (1-256) was approximately 99:1. Next, ET-1 was heated and evaporated to a thickness of 5 nm, and further, ET-2 and Liq were heated and evaporated to a thickness of 25 nm to form an electron transport layer consisting of two layers. The deposition rate was adjusted so that the weight ratio of ET-2 and Liq was approximately 1:1. The deposition rate of each layer was 0.01 to 1 nm/sec. Thereafter, LiF was heated and deposited at a deposition rate of 0.01 to 0.1 nm/sec so as to have a film thickness of 1 nm, and then aluminum was heated and deposited to have a film thickness of 100 nm to form a cathode, thereby obtaining an organic EL device. At this time, the deposition rate of aluminum was adjusted to be 1 to 10 nm/sec.

<Example 5, Comparative Examples 4 and 5>
The dopant and host in Example 4 were changed to those shown in Table 2, and devices were fabricated.

<Evaluation>
The fabricated element was subjected to DC voltage application with the ITO electrode as the anode and the aluminum electrode as the cathode, and the emission wavelength, half-width, driving voltage, external quantum efficiency, and LT97 (the time required to reach 97% of the initial luminance when continuously driven at a current density of 20 mA/ ^cm2 ) at a current density of 20 mA/ ^cm2 were measured. The evaluation results are shown in Table 2.

The polycyclic aromatic compound of the present invention is useful as a material for organic devices, in particular as a material for forming a light-emitting layer in an organic electroluminescent device.

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 110 Substrate 120 Electrode 130 Coating film 140 Coating film 150 Light-emitting layer 200 Bank 300 Inkjet head 310 Ink droplet

Claims (13)

A polycyclic aromatic compound represented by any one of the following formulas (3-1-1), (3-1-2), and (3-2-1):
In formula (3-1-1), formula (3-1-2), formula (3-2-1),
^X1 's are each independently >N-R or >O , and R in the >N-R is an aryl having 6 to 12 carbon atoms which may be substituted with an alkyl having 1 to 6 carbon atoms or a cycloalkyl having 3 to 14 carbon atoms, or a heteroaryl having 2 to 15 carbon atoms which may be substituted with an alkyl having 1 to 6 carbon atoms or a cycloalkyl having 3 to 14 carbon atoms;
Each Y is independently B ;
Each Z is independently -C(-R ^Z )=;
R ^Z are each independently a hydrogen atom, an aryl having 6 to 16 carbon atoms, a heteroaryl having 2 to 20 carbon atoms, a diarylamino (wherein the aryl has 6 to 10 carbon atoms) , an alkyl having 1 to 12 carbon atoms , or a cycloalkyl having 3 to 16 carbon atoms , in which at least one hydrogen atom may be substituted by an aryl having 6 to 16 carbon atoms , a heteroaryl having 2 to 20 carbon atoms , an alkyl having 6 to 16 carbon atoms , or a cycloalkyl having 3 to 16 carbon atoms ;
At least one hydrogen atom in the compounds represented by formula (3-1-1), formula (3-1-2) and formula (3-2-1) may be replaced with deuterium . The polycyclic aromatic compound according to claim 1, which is represented by any one of the following formulas:
In the formula, Me is methyl. 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 element is a material for a light-emitting layer. A composition comprising the polycyclic aromatic compound according to claim 1 or 2 and an organic solvent. 3. An organic electroluminescence device comprising a pair of electrodes consisting of an anode and a cathode, and an organic layer disposed between the pair of electrodes and containing the polycyclic aromatic compound according to claim 1 . The organic electroluminescent device according to claim 7 , wherein the organic layer is a light-emitting layer. The organic electroluminescent device according to claim 8 , wherein the light-emitting layer contains a host and the polycyclic aromatic compound as a dopant. The organic electroluminescent device according to claim 9 , wherein the host is an anthracene-based compound, a fluorene-based compound, or a dibenzochrysene-based compound. The organic electroluminescence device according to any one of claims 8 to 10, further comprising at least one of an electron transport layer and an electron injection layer disposed between the cathode and the light-emitting layer, and 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, arylnitrile derivatives, triazine derivatives, benzimidazole derivatives, phenanthroline derivatives, and quinolinol-based metal complexes. 12. The organic electroluminescent device according to claim 11, wherein at least one of the electron transport layer and the electron injection layer further contains 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. A display device or a lighting device comprising the organic electroluminescent device according to any one of claims 7 to 12 .