JP7679953B2 - Polycyclic aromatic compounds - Google Patents

Description

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

Display devices using electroluminescent light-emitting elements have been extensively studied because they can be made thinner and consume less power. Furthermore, organic electroluminescent elements (hereinafter sometimes referred to as "organic EL elements" or simply "elements") 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.

As materials for the light-emitting layer, for example, benzofluorene-based compounds have been developed (Patent Document 1). As hole transport materials, for example, triphenylamine-based compounds have been developed (Patent Document 2). As electron transport materials, for example, anthracene-based compounds have been developed (Patent Document 3).

In recent years, a material that improves triphenylamine derivatives has also been reported as a material for use in organic electroluminescence devices and organic thin-film solar cells (Patent Document 4). This material is characterized by its improved planarity, which is achieved by linking the aromatic rings that make up the triphenylamine with each other, based on N,N'-diphenyl-N,N'-bis(3-methylphenyl)-1,1'-biphenyl-4,4'-diamine (TPD), which has already been put to practical use. In this document, for example, the charge transport properties of an NO-linked compound (Compound 1 on page 63) are evaluated, but there is no description of a method for producing materials other than NO-linked compounds, and since the electronic state of the entire compound differs depending on the linked element, the properties obtained from materials other than NO-linked compounds are not yet known. There are other examples of such compounds (Patent Document 5). For example, a compound with a conjugated structure with a large triplet exciton energy (T1) can emit phosphorescence with a shorter wavelength, making it useful as a material for a blue light-emitting layer. In addition, compounds with a new conjugated structure with a large T1 are also required as electron transport materials and hole transport materials that sandwich the light-emitting layer.

The host material of an organic EL element is generally a molecule in which a plurality of existing aromatic rings such as benzene or carbazole are linked by single bonds, phosphorus atoms, or silicon atoms. This is because a large HOMO-LUMO gap (band gap Eg in a thin film) required for a host material is guaranteed by linking a large number of relatively small conjugated aromatic rings. Furthermore, a high triplet excitation energy (E _T ) is also required for a host material of an organic EL element using a phosphorescent material or a thermally activated delayed fluorescent material, but by linking a donor or acceptor aromatic ring or a substituent to the molecule, SOMO1 and SOMO2 in the triplet excited state (T1) are localized, and the exchange interaction between the two orbitals is reduced, making it possible to improve the triplet excitation energy (E _T ). However, the redox stability of small conjugated aromatic rings is insufficient, and an element using a molecule in which existing aromatic rings are linked as a host material does not have a sufficient life. On the other hand, polycyclic aromatic compounds having extended π-conjugated systems generally have excellent redox stability, but have been considered unsuitable as host materials due to their low HOMO-LUMO gap (band gap Eg in a thin film) and triplet excitation energy (E _T ).

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

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

In addition, Patent Document 6 reports a polycyclic aromatic compound containing boron and an organic EL device using the same. However, in order to further improve the device characteristics, there is a demand for a material for an emission layer, in particular a dopant material, that can improve the luminous efficiency and device life.
An object of the present invention is to provide a polycyclic aromatic compound having a novel structure and an organic EL device using the same.

As a result of intensive research to solve the above problems, the present inventors have found that an excellent organic EL element can be obtained by, for example, constructing an organic EL element by disposing a layer containing a polycyclic aromatic compound having a spiro structure between a pair of electrodes, and have completed the present invention. That is, the present invention provides a polycyclic aromatic compound having a spiro structure as shown below or a multimer thereof, and further provides a material for organic devices such as a material for an organic EL element containing a polycyclic aromatic compound having a spiro structure as shown below or a multimer thereof.

[1] A polycyclic aromatic compound represented by the following formula (1), or a multimer of a polycyclic aromatic compound having a plurality of structures represented by the following formula (1):

(In formula (1),
ring A, ring B and ring C each independently represent an aryl ring or a heteroaryl ring, and at least one hydrogen atom in these rings may be substituted;
^Y1 is B, P, P=O, P=S, Al, Ga, As, Si-R or Ge-R;
X ¹ 's are each independently a group represented by formula (1a), >O, >N-R, >C(-R) ₂ , >S, >Si(-R) ₂ , >S(=O) ₂ or >Se, and at least one X ¹ is a group represented by formula (1a),
In formula (1a),
ring D and ring E are each independently an aryl ring or a heteroaryl ring, and at least one hydrogen atom in these rings may be substituted;
^X2 is a single bond, >O, >N-R, >C(-R) ₂ , -C(-R) ₂ -C(-R) _2- , -C(-R)=C(-R)-, >S, >Si(-R) ₂ , >S(=O) ₂ or >Se;
* indicates the bond position.
R in the >N-R is each independently an optionally substituted aryl, an optionally substituted heteroaryl, an optionally substituted alkyl, or an optionally substituted cycloalkyl;
R in the Si-R, Ge-R, >C(-R) ₂ , -C(-R) ₂ -C(-R) ₂ -, -C(-R)=C(-R)- and >Si(-R) ₂ is each independently hydrogen, an optionally substituted aryl, an optionally substituted alkyl or an optionally substituted cycloalkyl;
R in >N-R, Si-R, Ge-R, >C(-R) ₂ , -C(-R) ₂ -C(-R) ₂ -, -C(-R)=C(-R)- and >Si(-R) ₂ may be bonded to at least one ring selected from the group consisting of ring A, ring B, ring C, ring D and ring E via a linking group or a single bond;
In the compound or structure represented by formula (1), at least one selected from the group consisting of aryl rings and heteroaryl rings may be condensed with at least one cycloalkane;
At least one hydrogen in the cycloalkane may be replaced; and
At least one -CH ₂ - in the cycloalkane may be replaced by -O-;
At least one hydrogen atom in the compound or structure represented by formula (1) may be replaced with deuterium, cyano, or halogen.

[2] Ring A, ring B, ring C, ring D and ring E are each independently an aryl ring or a heteroaryl ring, at least one hydrogen atom in these rings may be substituted with a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted diarylamino, a substituted or unsubstituted diheteroarylamino, a substituted or unsubstituted arylheteroarylamino, a substituted or unsubstituted diarylboryl (two aryls may be bonded via a single bond or a linking group), a substituted or unsubstituted alkyl, a substituted or unsubstituted cycloalkyl, a substituted or unsubstituted alkoxy, a substituted or unsubstituted aryloxy, or a substituted silyl, and these rings have a 5- or 6-membered ring that shares a bond with the central fused bicyclic structure of the above formula composed of Y ¹ and two X ^1s ,
In the case of a multimer, the polycyclic aromatic compound or a multimer thereof according to [1] is a dimer or trimer having two or three structures represented by formula (1).

[3] The polycyclic aromatic compound or multimer described in [1] or [2], which is a polycyclic aromatic compound represented by the following formula (2) or a multimer of a polycyclic aromatic compound having a plurality of structures represented by the following formula (2).

(In formula (2),
^Y1 is B, P, P=O, P=S, Al, Ga, As, Si-R or Ge-R;
X ¹ 's are each independently a group represented by formula (2a), >O, >N-R, >C(-R) ₂ , >S, >Si(-R) ₂ , >S(=O) ₂ or >Se, and at least one X ¹ is a group represented by formula (2a),
In formula (2a),
^X2 is a single bond, >O, >N-R, >C(-R) ₂ , -C(-R) ₂ -C(-R) _2- , -C(-R)=C(-R)-, >S, >Si(-R) ₂ , >S(=O) ₂ or >Se;
* indicates the bond position.
In formula (2) and formula (2a),
R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ , R ¹⁰ , R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁵ , R ¹⁶ , R ¹⁷ , R ¹⁸ , and R ¹⁹ 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, trialkylsilyl, tricycloalkylsilyl, dialkylcycloalkylsilyl, or alkyldicycloalkylsilyl, in which at least one hydrogen may be replaced by aryl, heteroaryl, alkyl, or cycloalkyl, and R ¹ , ^{R 2} , R 3 , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ , R ¹⁰ , R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁵ , R ¹⁶ , R ¹⁷ , R ¹⁸ , and R ¹⁹ may be bonded to each other to form an aryl ring or a heteroaryl ring together with the a ring, the b ring, the c ring, the d ring, or the e ring, and at least one hydrogen atom in the formed ring may be replaced by an aryl, a heteroaryl, a diarylamino, a diheteroarylamino, an arylheteroarylamino, a diarylboryl (two aryls may be bonded via a single bond or a linking group), an alkyl, a cycloalkyl, an alkoxy, an aryloxy, a trialkylsilyl, a tricycloalkylsilyl, a dialkylcycloalkylsilyl, or an alkyldicycloalkylsilyl, and at least one hydrogen atom in these rings may be replaced by an aryl, a heteroaryl, an alkyl, or a cycloalkyl,
R in the >N-R is each independently an optionally substituted aryl, an optionally substituted heteroaryl, an optionally substituted alkyl, or an optionally substituted cycloalkyl;
R in the Si-R, Ge-R, >C(-R) ₂ , -C(-R) ₂ -C(-R) ₂ -, -C(-R)=C(-R)- and >Si(-R) ₂ is each independently hydrogen, an optionally substituted aryl, an optionally substituted alkyl or an optionally substituted cycloalkyl;
R in >N-R, Si-R, Ge-R, >C(-R) ₂ , -C(-R) ₂ -C(-R) ₂ -, -C(-R)=C(-R)- and >Si(-R) ₂ may be bonded to at least one ring selected from the group consisting of ring a, ring b, ring c, ring d and ring e via a linking group or a single bond;
In the compound or structure represented by formula (2), at least one selected from the group consisting of an aryl ring and a heteroaryl ring may be condensed with at least one cycloalkane having 3 to 24 carbon atoms, at least one hydrogen in the cycloalkane may be substituted with an aryl having 6 to 30 carbon atoms, a heteroaryl having 2 to 30 carbon atoms, an alkyl having 1 to 24 carbon atoms, or a cycloalkyl having 3 to 24 carbon atoms, and at least one -CH ₂ - in the cycloalkane may be substituted with -O-,
At least one hydrogen atom in the compound or structure represented by formula (2) may be replaced with deuterium, cyano, or halogen.

[4] The polycyclic aromatic compound or a multimer thereof according to any one of [1] to [3], wherein Y ¹ is B.
[5] The polycyclic aromatic compound or a multimer thereof according to any one of [1] to [4], wherein one of X ¹ is a group represented by formula (1a), and the other X ¹ is >O, >N-R, >C(-R) ₂ , >S, >Si(-R) ₂ , >S(=O) ₂ or >Se.
[6] The polycyclic aromatic compound or a multimer thereof according to [5], wherein the other X ¹ is >N—R.
[7] The polycyclic aromatic compound or a multimer thereof according to [6], wherein X ² is a single bond.
[8] The polycyclic aromatic compound or a multimer _thereof according to any one of [1] to [6], wherein ^X2 is >O, >N-R, >C(-R) ₂ , -C(-R) ₂ -C(-R) _2- , -C(-R)=C(-R)-, >S, >Si(-R)2, >S(=O) ₂ or >Se.

[9] The polycyclic aromatic compound according to [1], or a multimer thereof, represented by any one of formula (1-1), formula (1-3), formula (1-21), formula (1-23), formula (1-41), formula (1-61), formula (1-83), and formula (1-103).

[10] A material for an organic device, comprising the polycyclic aromatic compound or a multimer thereof according to any one of [1] to [9].
[11] The material for an organic device according to [10], which is a material for an organic electroluminescent element, a material for an organic field effect transistor, or a material for an organic thin-film solar cell.
[12] The material for an organic device according to [11], wherein the material for an organic electroluminescent element is a material for a light-emitting layer.
[13] 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 or a multimer thereof according to any one of [1] to [9].
[14] An organic electroluminescence device comprising a pair of electrodes consisting of an anode and a cathode, and a light-emitting layer disposed between the pair of electrodes and containing the polycyclic aromatic compound or a multimer thereof according to any one of [1] to [9].
[15] The organic electroluminescent device according to [14], wherein the light-emitting layer contains a host and the polycyclic aromatic compound or a polymer thereof as a dopant.
[16] The organic electroluminescent device according to [15], wherein the host is an anthracene-based compound, a fluorene-based compound or a dibenzochrysene-based compound.

[17] The organic electroluminescence device according to any one of [14] to [16], which has an electron transport layer and/or 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, quinolinol-based metal complexes, thiazole derivatives, benzothiazole derivatives, silole derivatives, and azoline derivatives.
[18] The organic electroluminescence device according to [17], wherein the electron transport layer and/or 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.
[19] A display device comprising the organic electroluminescent device according to any one of [13] to [18].
[20] A lighting device comprising the organic electroluminescent element according to any one of [13] to [18].

The present invention provides a novel polycyclic aromatic compound or a multimer thereof. The polycyclic aromatic compound or a multimer thereof can be used as a material for an organic device, such as a material for an organic EL element. By using the polycyclic aromatic compound or a multimer thereof of the present invention as a material for an organic EL element, an organic EL element having excellent luminous efficiency and element life can be provided.

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

The present invention will be described in detail below. The following description 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 compounds and multimers thereof The polycyclic aromatic compounds of the present invention are compounds in which a spiro structure is introduced into the basic skeleton of a polycyclic aromatic compound in which aromatic rings are linked by hetero elements such as boron, phosphorus, oxygen, nitrogen, and sulfur.
The present inventors have found that the basic skeleton portion of such a polycyclic aromatic compound has a large HOMO-LUMO gap (band gap Eg in a thin film) and a high triplet excitation energy (E _T ). This is believed to be due to the fact that the six-membered ring containing a hetero element has low aromaticity, so that the decrease in the HOMO-LUMO gap accompanying the expansion of the conjugated system is suppressed, and that SOMO1 and SOMO2 in the triplet excited state (T1) are localized due to electronic perturbation of the hetero element. In addition, the polycyclic aromatic compound having the above basic skeleton portion has a small energy difference between the triplet excited state (T1) and the singlet excited state (S1), and exhibits thermally activated delayed fluorescence, and is therefore also useful as a fluorescent material for organic EL devices, including those that utilize thermally activated delayed fluorescence, since the exchange interaction between the two orbitals is reduced due to the localization of SOMO1 and SOMO2 in the triplet excited state (T1). In addition, materials having high triplet excitation energy (E _T ) are also useful as electron transport layers or hole transport layers in phosphorescent organic EL devices or organic EL devices using thermally activated delayed fluorescence. Furthermore, by introducing a substituent into the basic skeleton of these polycyclic aromatic compounds, the HOMO and LUMO energies can be arbitrarily moved, so that the ionization potential and electron affinity can be optimized according to the surrounding materials.

In addition to the characteristics of the basic skeleton, the polycyclic aromatic compound of the present invention has a spiro structure, which suppresses concentration quenching and is expected to improve the device life and luminous efficiency. The device life and luminous efficiency are important characteristic values of organic devices, and the use of the polycyclic aromatic compound of the present invention is expected to have an effect of improving the device characteristics. In addition, a decrease in melting point and sublimation temperature can be expected. This means that in sublimation purification, which is almost essential as a purification method for materials for organic devices such as organic EL elements that require high purity, purification can be performed at a relatively low temperature, so that thermal decomposition of the material can be avoided. This is also true for the vacuum deposition process, which is a powerful means for producing organic devices such as organic EL elements, and since the process can be performed at a relatively low temperature, thermal decomposition of the material can be avoided, and as a result, a high-performance organic device can be obtained. In addition, since many of the polymers of polycyclic aromatic compounds have a high sublimation temperature due to their molecular weight and high planarity, the reduction in sublimation temperature by introducing a spiro structure is more effective. In addition, since the solubility in organic solvents is improved by introducing a spiro structure, it becomes possible to apply it to the production of elements using a coating process. However, the present invention is not particularly limited to these principles.

The polycyclic aromatic compound or multimer of the present invention is a polycyclic aromatic compound represented by the following formula (1), or a multimer of a polycyclic aromatic compound having a plurality of structures represented by the following formula (1).

In formula (1), at least one of ^X1 is a group represented by formula (1a). The group represented by formula (1a) is bonded to ring A and ring B, or ring A and ring C of formula (1) at two *.

The polycyclic aromatic compound represented by formula (1) or the multimer of the polycyclic aromatic compound having a plurality of structures represented by the following formula (1) is preferably a polycyclic aromatic compound represented by formula (2) or a multimer of the polycyclic aromatic compound having a plurality of structures represented by formula (2).

In formula (2), at least one of ^X1 is a group represented by formula (2a). The group represented by formula (2a) is bonded to ring a and ring b, or ring a and ring c of formula (2) at two *.

The A ring, B ring, and C ring in formula (1) correspond to the a ring and its substituents R ¹ to R ³ , the b ring and its substituents R ⁸ to R ¹¹ , and the c ring and its substituents R ⁴ to R ⁷ in formula (2), respectively. The D ring and E ring in formula (1a) correspond to the d ring and its substituents R ¹⁶ to R ¹⁹ , and the e ring and its substituents R ¹² to R ¹⁵ in formula (2a), respectively. That is, formula (2) corresponds to a structure in which "6-membered A to E rings" are selected as the A to E rings in formula (1). In that sense, each ring in formula (2) is represented by lowercase letters a to e.

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

Here, the term "fused bicyclic structure" refers to a structure in which two saturated hydrocarbon rings, which are composed of ^Y1 and two ^X1, are fused together, as shown in the center of formula (1). The term "six-membered ring sharing a bond with the fused bicyclic structure" refers to a ring (benzene ring (six-membered ring)) fused to the fused bicyclic structure, as shown in formula (2), for example. The term "aryl ring or heteroaryl ring (A ring) has this six-membered ring" refers to the six-membered ring alone forming the A ring, or the six-membered ring is further fused to another ring to form the A ring so as to include the six-membered ring. In other words, the term "aryl ring or heteroaryl ring (A ring) having a six-membered ring" refers to the six-membered ring constituting all or a part of the A ring being fused to the fused bicyclic structure. The same explanation applies to "B ring (b ring)", "C ring (c ring)", and "five-membered ring".

In formula (2) and formula (2a), the substituents R ¹ , R ² , R 3 , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R 8 , R ⁹ , R ¹⁰ , R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁵ , R ¹⁶ , R ^{17 ,} R ^{18 ,} and R Adjacent groups among ¹⁹ may be bonded together to form an aryl or heteroaryl ring together with ring a, ring b, ring c, ring d, or ring e, and at least one hydrogen atom 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, trialkylsilyl, tricycloalkylsilyl, dialkylcycloalkylsilyl, or alkyldicycloalkylsilyl, and at least one hydrogen atom in these may be substituted with aryl, heteroaryl, alkyl, or cycloalkyl. Therefore, the polycyclic aromatic compound represented by formula (2) has a ring structure that constitutes the compound that changes as shown in the following formulas (2-1) and (2-2) depending on the mutual bonding form of the substituents in ring a, ring b, ring c, ring d, and ring e. Ring A', ring B', and ring C' in each formula correspond to ring A, ring B, and ring C in formula (1), respectively.

In the above formula (2-1) and formula (2-2), the ring A', ring B' and ring C' are, when explained in formula (2), aryl or heteroaryl rings formed by bonding adjacent groups among the substituents R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ , R ¹⁰ and R ¹¹ together with the ring a, ring b and ring c (they may also be considered as condensed rings formed by condensing other ring structures to the ring a, ring b or ring c). Although not shown in the formula, there are also compounds in which all of the ring a, ring b and ring c are changed to ring A', ring B' and ring C'. As can be seen from the above formulas (2-1) and (2-2), for example, R ⁸ of ring b and R ⁷ of ring c, R ¹¹ of ring b and R ¹ of ring a, R ⁴ of ring c and R ³ of ring a, etc. are not "adjacent groups" and are not bonded to each other. In other words, "adjacent groups" means groups adjacent to each other on the same ring.

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

In formula (1), Y ¹ is B, P, P═O, P═S, Al, Ga, As, Si-R, or Ge-R, and R in the Si-R and Ge-R is an optionally substituted aryl, an optionally substituted alkyl, or an optionally substituted cycloalkyl. In the case of P═O, P═S, Si-R, or Ge-R, the atom bonded to ring A, ring B, or ring C is P, Si, or Ge. ^{Y 1} is preferably B, P, P═O, P═S, or Si-R, and particularly preferably B.

X ¹ in formula (1) is a group represented by formula (1a), >O, >N-R, >C(-R) ₂ , >S, >Si(-R) ₂ , >S(=O) ₂ or >Se, and at least one is a group represented by formula (1a). It is preferable that one of X ¹ is a group represented by formula (1a), and the other is >O, >N-R, >C(-R) ₂ , >S, >Si(-R) ₂ , >S(=O) ₂ or >Se. This explanation is similar to that for X ¹ in formula (2). That is, formula (1) is preferably the following formula (1-A), and formula (2) is preferably the following formula (2-A).

In formula (1-A), ring A, ring B, ring C, ring D and ring E have the same meanings as ring A, ring B, ring C, ring D and ring E in formula (1), respectively, and the preferred ranges are also the same. Y ¹ has the same meaning as Y ¹ in formula (1), and the preferred ranges are also the same. X ² has the same meaning as X ² in formula (1a), and the preferred ranges are also the same. X ^1A is >O, >N-R, >C(-R) ₂ , >S, >Si(-R) ₂ , >S(=O) ₂ or >Se. R in the >N-R is an optionally substituted aryl, an optionally substituted heteroaryl, an optionally substituted alkyl or an optionally substituted cycloalkyl. R in the above-mentioned Si-R, Ge-R, >C(-R) ₂ , -C(-R) ₂ -C(-R) ₂ -, -C(-R)=C(-R)- and >Si(-R) ₂ is hydrogen, optionally substituted aryl, optionally substituted alkyl or optionally substituted cycloalkyl.

In formula (2-A), ^Y1 has the same definition as ^Y1 in formula (1), and the preferred range is also the same. ^X2 has the same definition as ^X2 in formula (1a), and the preferred range is also the same. ^X1A has the same definition as ^X1A in formula (1-A), and the preferred range is also the same. R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ , R ¹⁰ , R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁵ , R ¹⁶ , R ¹⁷ , R ¹⁸ , and R ¹⁹ are each synonymous with R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ , R ¹⁰ , R ^{11 , R 12 ,} R ¹³ , R ¹⁴ , R ¹⁵ , R ¹⁶ , R ¹⁷ , R ¹⁸ , and R ¹⁹ in formula (2), and the preferred ranges are also the same.

It is preferable that one of X ¹ in formula (1) is a group represented by formula (1a) and the other is >O or >N-R, and it is particularly preferable that one of X 1 is a group represented by formula (1a) and the other is >N-R. This explanation is the same for X ¹ in formula (2). That is, in each of formulas (1-A) and (2-A), X ^1A is preferably >O or >N-R, and more preferably >N-R.

X ² in formula (1a) is a single bond, >O, >N-R, >C(-R) ₂ , -C(-R) ₂ -C(-R) ₂ -, -C(-R)=C(-R)-, >S, >Si(-R) ₂ , >S(=O) ₂ or >Se. ^{X 2} is preferably a single bond, >O or >N-R, and is particularly preferably a single bond. In particular, when one of X ¹ is a group represented by formula (1a) and the other is >N-R, X ² is preferably a single bond, >O or >N-R, and is particularly preferably a single bond. These explanations are the same for X ² in formula (2a).

From the viewpoint of ease of synthesis, it is preferable that formula (1a) is a group having a symmetric structure that does not cause stereoisomerism in the compound represented by formula (1). Similarly, from the viewpoint of ease of synthesis, it is preferable that formula (2a) is a group having a symmetric structure that does not cause stereoisomerism in the compound represented by formula (2). On the other hand, from the viewpoint of the light-emitting properties of the element, it may be a group having an asymmetric structure that causes stereoisomers, and the stereoisomers may be used separately or mixed. It is sufficient to use a stereoisomer ratio suited to the application.

In X ¹ in formula (1) and X ² in formula (1a), R in the >N-R is (when a plurality of >N-Rs are present, each of them is independently) an optionally substituted aryl, an optionally substituted heteroaryl, an optionally substituted alkyl or an optionally substituted cycloalkyl, R in the >C(-R) ₂ , -C(-R) ₂ -C(-R) ₂ -, -C(-R)=C(-R)- and >Si(-R) ₂ is (when a plurality of >N-Rs are present, each of them is independently) a hydrogen, an optionally substituted aryl, an optionally substituted alkyl or an optionally substituted cycloalkyl, and R in the >N-R, >C(-R) ₂ , -C(-R) ₂ -C(-R) ₂ -, -C(-R)=C(-R)- and >Si(-R) R in ₂ may be bonded to at least one ring selected from the group consisting of ring A, ring B, ring C, ring D and ring E through a linking group or a single bond, and the linking group is preferably -O-, -S- or -C(-R) ₂ -. Note that R in the above "-C(-R) ₂ -" is hydrogen, alkyl or cycloalkyl. This explanation also applies to X ¹ and X ² in formula (2) and formula (2a).

Here, the provision in formula (1) that "R in the >N-R, >C(-R) ₂ , -C(-R) ₂ -C(-R) ₂ -, -C(-R)=C(-R)- is bonded to at least one ring selected from the group consisting of ring A, ring B, ring C, ring D and ring E through a linking group or a single bond" corresponds to the provision in formula (2) that "R in the >N-R, >C(-R) ₂ , -C(-R) ₂ -C(-R) ₂ -, -C(-R)=C(-R)- is bonded to at least one ring selected from the group consisting of ring a, ring b, ring c, ring d and ring e through -O-, -S-, -C(-R) ₂ - or a single bond".

Preferred examples of the structures in which R in >N-R, >C(-R) ₂ , -C(-R) ₂ -C(-R) ₂ -, -C(-R)=C(-R)- and >Si(-R) ₂ is bonded to at least one ring selected from the group consisting of ring A, ring B, ring C, ring D and ring E via a linking group or a single bond include structures in which R in >N-R, >C(-R) ₂ and >Si(-R) ₂ in X ¹ is bonded to at least one ring selected from the group consisting of ring A, ring B and ring C via a linking group or a single bond. For example, in formula (2), the structures correspond to the structures in which R in >N-R, >C(-R) ₂ and >Si(-R) ₂ in X ¹ is bonded to at least one ring selected from the group consisting of ring a, ring b and ring c via a linking group or a single bond. More preferred examples include structures in which R of >N--R in ^X1 is bonded to at least one ring selected from the group consisting of ring A, ring B and ring C via a linking group or a single bond.

The above definition can be expressed by a compound having a ring structure in which ^X1 is incorporated into a fused ring C', as represented by the following formula (2-3-1), and a compound having a ring structure in which ^X1 is incorporated into a fused ring A', as represented by the following formula (2-3-2). That is, for example, it is a compound having a ring C' formed by condensing another ring to the benzene ring, which is ring c in formula (2), so as to incorporate ^X1 . The fused ring C' thus formed is, for example, a carbazole ring, a phenoxazine ring, a phenothiazine ring, or an acridine ring.

The "aryl ring" which is ring A, ring B, ring C, ring D and ring E in formula (1) includes, for example, an aryl ring having 6 to 30 carbon atoms, preferably an aryl ring having 6 to 16 carbon atoms, more preferably an aryl ring having 6 to 12 carbon atoms, and particularly preferably an aryl ring having 6 to 10 carbon atoms. This "aryl ring" corresponds to "an aryl ring formed together with ring ^a , ring b, ring c, ring d or ring e by adjacent groups among R ¹ , R ² , R ³ , R ⁴ , R ⁵ , ^{R 6} , R ⁷ , R ⁸ , R ⁹ , R ¹⁰ , R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁵ , R ¹⁶ , R 17, R 18, and R ¹⁹ bonding to each other" defined in formula (2), and since ring a (or ring b, ring c, ring d or ring e) is already composed of a benzene ring having 6 carbon atoms, the minimum carbon number is 9, the total number of carbon atoms of the fused rings formed by condensing a 5-membered ring to this.

Specific examples of the "aryl ring" 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, and a phenanthrene ring, a fused tetracyclic triphenylene ring, a pyrene ring, and a naphthacene ring, and a fused pentacyclic perylene ring and a pentacene ring.
Both ring D and ring E are preferably benzene rings which may have a substituent, and more preferably unsubstituted benzene rings.

Examples of the "heteroaryl ring" which is ring A, ring B, ring C, ring D and ring E in formula (1) include heteroaryl rings having 2 to 30 carbon atoms, preferably heteroaryl rings having 2 to 25 carbon atoms, more preferably heteroaryl rings having 2 to 20 carbon atoms, still more preferably heteroaryl rings having 2 to 15 carbon atoms, and particularly preferably heteroaryl rings 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. Note that this "heteroaryl ring" corresponds to "a heteroaryl ring formed together with ring a, ring ^b , ring c, ring d or ^ring e by adjacent groups among R ¹ , R ² , R ³ , R ⁴ , R ⁵ , ^{R 6, R 7 , R 8} , R ⁹ , R ¹⁰ , R ¹¹ , R ¹² , R 13, R ¹⁴ , R ¹⁵ , R ¹⁶ , R 17, R 18, and R ¹⁹ bonding to each other" defined in formula (2), and since ring a (or ring b, ring c, ring d or ring e) is already composed of a benzene ring having 6 carbon atoms, the minimum carbon number is 6, the total number of carbon atoms of the fused rings formed by condensing the 5-membered ring to this.

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, and a 1H-benzotriazo Examples of such rings include an aryl 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, 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, and a thianthrene ring.

In addition, when the "aryl ring" and the "heteroaryl ring" are fused rings in which two or more rings are fused, any of the rings may share a bond with the fused bicyclic structure, but as described above, the ring sharing a bond with the fused bicyclic structure is preferably a 5-membered ring or a 6-membered ring. That is, for example, in formula (2), when adjacent groups among R ¹ , R 2 , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ , R ^{10 ,} and R ¹¹ are bonded to each other to form an aryl ring or a heteroaryl ring together with the a ring, the b ring, or the c ring, the 6-membered benzene ring shares a bond with the fused bicyclic structure, which is preferable. In addition, for example, it is also preferable that the indole ring, the benzofuran ring, and the benzothiophene ring share a bond with the fused bicyclic structure through the 5-membered pyrrole ring, the furan ring, and the thiophene ring, respectively. Examples of such structures include compounds having a structure corresponding to a structure in which the benzene ring, which is the c ring (or the b ring) of formula (2), is replaced with a benzofuran ring or a benzothiophene ring, and are represented by any of the following formulas (1-412) to (1-419).

At least one hydrogen atom in the above "aryl ring" or "heteroaryl ring" may be substituted.
The number of substitutions is not particularly limited, but the total number of hydrogen atoms substituted in ring A, ring B, ring C, ring D and ring E is preferably 0 to 10, more preferably 0 to 5, even more preferably 0 to 3, and particularly preferably 0 to 2. In addition, in each of ring A, ring B, ring C, ring D and ring E, it is preferable that 0 to 2 hydrogen atoms in the aryl ring or heteroaryl ring are substituted, and more preferably 0 to 1 hydrogen atom is substituted.

From the viewpoint of physical properties such as reducing intermolecular interactions and improving efficiency and lifetime during device fabrication, it is preferable that at least one hydrogen atom of an aryl ring or heteroaryl ring in at least one of ring A, ring B, ring C, ring D, and ring E is substituted.
From the viewpoints of both synthesis and physical properties, it is preferable that 0 to 1 hydrogen atom in the aryl or heteroaryl ring is substituted in any of the A ring, B ring, C ring, D ring and E ring;
It is more preferable that 0 to 1 hydrogen atom of the aryl or heteroaryl ring in any of rings A, B and C is substituted, and that the aryl or heteroaryl ring in rings D and E is unsubstituted.

When at least one hydrogen atom in the "aryl ring" or "heteroaryl ring" is replaced, the substituent may be a first substituent, such as 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 (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", or a substituted "silyl".

As the first substituent, the aryl of "aryl" or "heteroaryl", the aryl of "diarylamino", the heteroaryl of "diheteroarylamino", the aryl and heteroaryl of "arylheteroarylamino", the aryl of "diarylboryl", and the aryl of "aryloxy" include the monovalent groups of the "aryl ring" or "heteroaryl ring" described above.

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

Specific 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, t-octyl, and 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 "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 4 carbon atoms, as well as norbornenyl, bicyclo[1.0.1]butyl, bicyclo[1.1.1]pentyl, bicyclo[2.0.1]pentyl, bicyclo[1.2.1]hexyl, bicyclo[3.0.1]hexyl, bicyclo[2.1.2]heptyl, bicyclo[2.2.2]octyl, adamantyl, diamantyl, decahydronaphthalenyl, and decahydroazulenyl.

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

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

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

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

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

"Tricycloalkylsilyl" refers to a group in which three hydrogen atoms in a silyl group are each independently replaced with a cycloalkyl, and the cycloalkyl can be cited from the groups 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 (the above, the first substituent), and the first substituent may be further substituted with aryl, heteroaryl, alkyl, or cycloalkyl (the above, the second substituent), and as specific examples of these groups, the above description of the aryl, heteroaryl, diarylamino, alkyl, cycloalkyl, alkoxy, or aryloxy as the first substituent can be cited.

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 "alkyl" or "cycloalkyl" as the first substituent. In addition, the aryl and heteroaryl as the second substituent also include structures in which at least one hydrogen atom in the aryl and heteroaryl as the second substituent is replaced with an aryl such as phenyl (specific examples are the groups described above), an alkyl such as methyl (specific examples are the groups described above), or a cycloalkyl such as cyclohexyl (specific examples are the groups described above). As an example, when the second substituent is carbazolyl, the 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 aryl ^, heteroaryl ^, aryl of diarylamino ^, heteroaryl of diheteroarylamino, aryl and heteroaryl of arylheteroarylamino, aryl of diarylboryl, and aryl of aryloxy in ^{R 1} , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ^{7 ,} R ⁸ , R ⁹ , R ¹⁰ , and R ¹¹ in formula (2) and R ¹² , R ¹³ , R 14, R 15, R 16, ^R 17, R 18, and R 19 in formula (2a) include monovalent groups of "aryl ring" or "heteroaryl ring" explained in formula (1). In addition, for the alkyl, cycloalkyl or ^alkoxy in R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ , R ¹⁰ , R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁵ , R ¹⁶ , R ¹⁷ , R 18 and R ¹⁹ , the explanation of "alkyl", "cycloalkyl" or "alkoxy" as the first substituent in the explanation of the above formula (1) can be referred to. Furthermore, the same applies to the aryl, heteroaryl, alkyl or cycloalkyl as the substituent to these groups. In addition, when adjacent groups among R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ , R ¹⁰ , and R ¹¹ are bonded to each other to form an aryl ring or heteroaryl ring together with ring a, ring b, or ring c, the same applies to the heteroaryl, diarylamino, diheteroarylamino, arylheteroarylamino, diarylboryl (the two aryls may be bonded via a single bond or a linking group), alkyl, cycloalkyl, alkoxy, or aryloxy that are substituents on these rings, and the aryl, heteroaryl, alkyl, or cycloalkyl that are further substituents.

Specifically, the emission wavelength can be adjusted by the steric hindrance, electron donating property and electron withdrawing property of the structure of the first substituent, and is preferably a group represented by the following structural formula, and more preferably, methyl, t-butyl, t-pentyl (t-amyl), 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, Preferred are carbazolyl, 3,6-dimethylcarbazolyl, 3,6-di-t-butylcarbazolyl and phenoxy, and more preferred are methyl, t-butyl, t-pentyl (t-amyl), 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-pentyl (t-amyl), 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 structural formula below, "Me" is methyl, "tBu" is t-butyl, "tAm" is t-amyl, "tOct" is t-octyl, and * indicates the bond position.

In formula (2), it is preferred that 0 to 3 of R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ , R ¹⁰ , and R ¹¹ are groups represented by any of the structural formulas above, and the remainder are hydrogen. More specifically, it is preferred that 0 to 1 of R ¹ , R ² , and R ³ are groups represented by any of the structural formulas above, and the remainder are hydrogen, that 0 to 1 of R ⁴ , R ⁵ , R ⁶ , and R ⁷ are groups represented by any of the structural formulas above, and the remainder are hydrogen, and that 0 to 1 of R ⁸ , R ⁹ , R ¹⁰ , and R ¹¹ are groups represented by any of the structural formulas above, and the remainder are hydrogen. It is more preferable that R ¹ , R ² and R ³ are all hydrogen, or that R ¹ and R ³ are each hydrogen and R ² is a group represented by any one of the above structural formulas.

In addition, it is preferable that 1 to 4 of R ¹² , R ¹³ , R ¹⁴ , R ¹⁵ , R ¹⁶ , R ¹⁷ , R ¹⁸ , and R ¹⁹ in formula (2a) are groups represented by any of the structural formulas above, and the remainder are hydrogen; it is more preferable that 0 to 2 of R ¹² , R ¹³ , R ¹⁴ , and R ¹⁵ are groups represented by any of the structural formulas above, the remainder are hydrogen, and 1 to 2 of R ¹⁶ , R ¹⁷ , R ¹⁸ , and R ¹⁹ are groups represented by any of the structural formulas above, and the remainder are hydrogen. From the viewpoint of ease of synthesis, it is also preferable that R ¹² , R ¹³ , R ¹⁴ , R ¹⁵ , R ¹⁶ , R ¹⁷ , R ¹⁸ , and R ¹⁹ are all hydrogen.

R of >N-R in X ¹ of formula (1) and X ² of formula (1a) is an aryl, heteroaryl, alkyl or cycloalkyl which may be substituted with the second substituent described above, and at least one hydrogen in the aryl, heteroaryl, alkyl or cycloalkyl may be substituted with, for example, an alkyl or cycloalkyl. Examples of the aryl, heteroaryl, alkyl or cycloalkyl include the groups described above. In particular, an aryl having 6 to 10 carbon atoms (e.g., phenyl, naphthyl, etc.), a heteroaryl having 2 to 15 carbon atoms (e.g., carbazolyl, etc.), an alkyl having 1 to 5 carbon atoms (e.g., methyl, ethyl, etc.), or a cycloalkyl having 5 to 10 carbon atoms (preferably cyclohexyl or adamantyl) is preferred. This explanation is the same for X ¹ in formula (2) and X ² in formula (2a).

In X ¹ and Y ¹ in formula (1), Si-R in X ² in formula (1a), Ge-R in Y ¹ in formula (1), >C(-R) ² , -C(-R) ₂ -C(-R) ₂ -, and -C(-R)=C(-R)- in X ¹ in _formula (1) and X 2 in formula (1a), R is hydrogen, an aryl, an alkyl, or a cycloalkyl which may be substituted with the second substituent described above, and at least one hydrogen in the aryl may be substituted with, for example, an alkyl. Examples of the aryl, alkyl, or cycloalkyl include the groups described above. In particular, an aryl having 6 to 10 carbon atoms (e.g., phenyl, naphthyl, etc.), an alkyl having 1 to 5 carbon atoms (e.g., methyl, ethyl, etc.), or a cycloalkyl having 5 to 10 carbon atoms (preferably cyclohexyl or adamantyl) is preferred. This explanation also applies to X ¹ and Y ¹ in formula (2) and X ² in formula (2a).

In formula (1), R in the linking group "-C(-R) ₂ -" is hydrogen, alkyl, or cycloalkyl, and examples of this alkyl or cycloalkyl include the groups described above. In particular, alkyl having 1 to 4 carbon atoms (e.g., methyl, ethyl, etc.) or cycloalkyl having 5 to 10 carbon atoms (preferably cyclohexyl or adamantyl) is preferred. This explanation also applies to the linking group "-C(-R) ₂ -" in formula (2).

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

Examples of such multimers include multimer compounds in which at least one of X ¹ is a group represented by formula (2a) in the following formula (2-4), formula (2-4-1), formula (2-5-1) to formula (2-5-4), or formula (2-6). The multimer compound represented by the following formula (2-4) is a multimer compound (ring-sharing multimer) having a plurality of unit structures represented by formula (2) in one compound, in such a way that the benzene ring, which is the a-ring, is shared. The multimer compound represented by the following formula (2-4-1) is a multimer compound (ring-sharing multimer) having two unit structures represented by formula (2) in one compound, in such a way that the benzene ring, which is the a-ring, is shared. Moreover, the multimeric compound represented by the following formula (2-4-2), when explained in terms of formula (2), is a multimeric compound (ring-sharing type multimer) having three unit structures represented by formula (2) in one compound, so as to share a benzene ring that is an a ring. Moreover, the multimeric compounds represented by the following formulas (2-5-1) to (2-5-4), when explained in terms of formula (2), are multimeric compounds (ring-sharing type multimers) having a plurality of unit structures represented by formula (2) in one compound, so as to share a benzene ring that is a b ring (or a ring) in one compound. Moreover, the multimeric compound represented by the following formula (2-6), when explained in terms of formula (2), is a multimeric compound (ring-condensed type multimer) having a plurality of unit structures represented by formula (2) in one compound, so as to condense a benzene ring that is a b ring (or a ring, c ring) of a certain unit structure with a benzene ring that is a b ring (or a ring, c ring) of a certain unit structure.

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

In addition, at least one selected from the group consisting of aryl rings and heteroaryl rings in the chemical structure of the polycyclic aromatic compound represented by formula (1) and its multimer (preferably the polycyclic aromatic compound represented by formula (2) and its multimer) may be condensed with at least one cycloalkane.

For example, at least one of the aryl and heteroaryl rings which are ring A, ring B, ring C, ring a, ring b and ring c, the aryl (aryl moiety in aryl, diarylamino, arylheteroarylamino, diarylboryl or aryloxy) and heteroaryl (heteroaryl moiety in heteroaryl, diheteroarylamino or arylheteroarylamino) as the first and second substituents on ring A to ring C, the aryl (similar to above) and heteroaryl (similar to above) as the first and second substituents on ring ^a to ring c, the aryl (similar to above) as R in Si-R and Ge-R which are ^Y1 , and the aryl (similar to above) ^and heteroaryl (similar to above) as R in >N-R and >C(-R) ₂ which are X1 and X2 may be fused with at least one cycloalkane.

Preferably, at least one of the aryl and heteroaryl rings which are ring A, ring B, ring C, ring a, ring b and ring c, the aryl (aryl moiety in aryl, diarylamino, diarylboryl or aryloxy) and heteroaryl (heteroaryl moiety in heteroaryl or diheteroarylamino) as the first substituents on ring A to ring C, the aryl (similar to above) and heteroaryl (similar to above) as the first substituents on ring a to ring c, and the aryl (similar to above) and heteroaryl (similar to above) as R of >N-R and >C(-R) ₂ which are ^X1 and ^X2 , are fused with at least one cycloalkane.

More preferably, at least one of the aryl rings which are ring A, ring B, ring C, ring a, ring b and ring c, the aryl (aryl or aryl moiety in diarylamino) and heteroaryl (heteroaryl moiety in heteroaryl) as the first substituents on ring A to ring C, the aryl (similar to above) and heteroaryl (similar to above) as the first substituents on ring a to ring c, and the aryl (similar to above) as R of >N-R and >C(-R) ₂ which are ^X1 and ^X2 , is fused with at least one cycloalkane.

More preferably, at least one of the aryl rings which are ring A, ring B, ring C, ring a, ring b and ring c, the aryl as the first substituent on ring A to ring C (aryl or aryl moiety in diarylamino), the aryl as the first substituent on ring a to ring c (similar to above), and the aryl as R of >N-R which is ^X1 and ^X2 and >C(-R) ₂ (similar to above) is condensed with at least one cycloalkane.

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

Specific examples of cycloalkanes include cyclopropane, cyclobutane, cyclopentane, cyclohexane, cycloheptane, cyclooctane, cyclononane, cyclodecane, norbornene, bicyclo[1.0.1]butane, bicyclo[1.1.1]pentane, bicyclo[2.0.1]pentane, bicyclo[1.2.1]hexane, bicyclo[3.0.1]hexane, bicyclo[2.1.2]heptane, bicyclo[2.2.2]octane, adamantane, diamantane, decahydronaphthalene, and decahydroazulene, as well as alkyl (especially methyl) substituted, halogen (especially fluorine) substituted, and deuterium substituted derivatives of these having 1 to 4 carbon atoms.

In addition, all or a part of hydrogen in the chemical structure of the polycyclic aromatic compound and its multimer represented by formula (1) or (2) may be deuterium, cyano, or halogen. For example, in formula (1), hydrogen in ring A, ring B, ring C (rings A to C are aryl rings or heteroaryl rings), substituents on rings A to C, R (= alkyl, cycloalkyl, aryl) when Y ¹ is Si-R or Ge-R, and R (= alkyl, cycloalkyl, aryl) when X ¹ and X ² are >N-R or >C(-R) ₂ may be replaced with deuterium, cyano, or halogen, and among these, embodiments in which all or a part of hydrogen in aryl or heteroaryl is replaced with deuterium, cyano, or halogen can be exemplified. The halogen is fluorine, chlorine, bromine, or iodine, preferably fluorine, chlorine, or bromine, and more preferably fluorine or chlorine.

The polycyclic aromatic compound and its multimer according to the present invention can be used as a material for an organic device, such as an organic electroluminescent device, an organic field effect transistor, or an organic thin-film solar cell. In particular, in the organic electroluminescent device, the dopant material of the light-emitting layer is preferably a compound in which ^Y1 is B, one of ^X1 is a group represented by formula (1a), the other is >N-R, and ^X2 is a single bond, a compound in which ^Y1 is B, one of ^X1 is a group represented by formula (1a), the other is >O, and ^X2 is a single bond, or a compound in which ^Y1 is B, one of ^X1 is a group represented by formula (1a), the other is >N-R, and ^X2 is >N-R; the host material of the light-emitting layer is preferably a compound in which ^Y1 is B, one of ^X1 is a group represented by formula (1a), the other is >O, and ^X2 is >N-R, or a compound in ^{which Y1} is B, one of ^X1 is a group represented by formula (1a), the other is >O, and ^X2 is >O; and the electron transport material is preferably a compound in which ^Y1 is B, one of ^X1 is a group represented by formula (1a), the other is >O, and ^X2 is >O, or A compound in which ¹ is P=O, one of ^X1 is a group represented by formula (1a) and the other is >O, and ^X2 is >O is preferably used.

Specific examples include compounds represented by the following formulas (1-1) to (1-423). In the structural formulas below, "Me" represents methyl and "D" represents deuterium.

Among these, compounds represented by formulas (1-1), (1-3), (1-21), (1-23), (1-41), (1-61), (1-83), and (1-103) are preferred, and compounds represented by formulas (1-1), (1-3), (1-23), (1-83), and (1-103) are more preferred.

<Method for producing polycyclic aromatic compound represented by formula (1) and its multimer>
A method for producing a polycyclic aromatic compound represented by formula (1) and a multimer thereof will be described. Basically, an intermediate is produced by first bonding an A ring (a ring) and a B ring (b ring) with a condensed two-ring structure (see first reaction: scheme (1) and scheme (2)). Next, an A ring (a ring), a C ring (c ring) and a bonding group (a group containing ^X1 ) are bonded (see second reaction: scheme (3)). Furthermore, methoxy is converted to an OTf group (see third reaction: scheme (4)), and the OTf group is converted to a boronic acid ester group such as a BPin group to obtain an intermediate compound (see fourth reaction: scheme (5)). Then, a Lewis acid such as aluminum chloride can be used to obtain the desired polycyclic aromatic compound (see fifth reaction: scheme (6)).

This will be explained in detail using Schemes 1 to 6. An alcohol is obtained by an addition reaction to a cyclic ketone (Scheme (1)), and then the A ring (a ring) and the B ring (b ring) can be bonded to a fused two-ring structure by an acid-catalyzed Friedel-Crafts reaction with a B ring (b ring) precursor (Scheme (2)).

In the second reaction, the A ring (a ring) and the C ring (c ring) are bonded by a reaction between a bonding group (a group containing ^X1 ) and a halogen atom (Hal). For example, in the case of an etherification reaction, a general reaction such as a nucleophilic substitution reaction or an Ullmann reaction can be used, and in the case of an amination reaction, a general reaction such as the Buchwald-Hartwig reaction can be used (Scheme (3)). When ^X1 is S or Se, known reactions can also be used.

In the third reaction, methoxy is converted to --OH using boron tribromide or the like, and then converted to an --OTf group using trifluoromethanesulfonic anhydride (Tf ₂ O) or the like (Scheme 4). Here, methoxy may be another alkoxy, and the Tf group may be another sulfonic acid group such as a tosyl group.

In the fourth reaction, the -OTf group is converted to a boronate group such as a -Bpin group (Bpin is a group in which -B(OH) ₂ is pinacol esterified) using a palladium catalyst such as the Miyaura reaction to obtain an intermediate compound (Scheme (5)). Here, the boronate group may be a boronic acid group or an ester group with another alcohol.

In the fifth reaction, the intermediate compound can be converted to the desired polycyclic aromatic compound using a Lewis acid such as aluminum chloride by the method described in JP 2018-076281 A (Scheme (6)). A base such as diisopropylethylamine (DIPEA) may be added to this reaction.

In addition, by using a cycloalkane-condensed raw material somewhere in these reaction steps or by adding a step of condensing a cycloalkane, it is possible to produce the compound of the present invention in which the desired position is condensed with a cycloalkane.

Moreover, polymers can also be produced by appropriately changing the raw materials (Scheme (7)).

Examples of Bronsted bases used in the above schemes (1) to (7) include N,N-diisopropylethylamine, triethylamine, 2,2,6,6-tetramethylpiperidine, 1,2,2,6,6-pentamethylpiperidine, N,N-dimethylaniline, N,N-dimethyltoluidine, 2,6-lutidine, sodium tetraphenylborate, potassium tetraphenylborate, triphenylborane, tetraphenylsilane, Ar ₄ BNa, Ar ₄ BK, Ar ₃ B, and Ar ₄ Si (Ar is an aryl such as phenyl).

Examples of Lewis acids used in the above schemes (1) to (7) include _AlCl3 , AlBr3, _AlF3 , _BF3.OEt2 , _BCl3 , _BBr3 , _GaCl3 , _GaBr3 , _InCl3 , InBr3, In(OTf) ₃ , _SnCl4 , _SnBr4 , _AgOTf , _ScCl3 , Sc ₍ OTf) ₃ , _ZnCl2 , ZnBr2 _, Zn(OTf) ₂ , MgCl2, _MgBr2 , Mg(OTf) ₂ , LiOTf, NaOTf, KOTf, _Me3SiOTf , Cu(OTf) _{2 , CuCl2} , _YCl3 , _and Y(OTf) _3. , _TiCl4 , _TiBr4 , _ZrCl4 , _ZrBr4 , _FeCl3 , _FeBr3 , _CoCl3 , _CoBr3 , etc.

The polycyclic aromatic compounds and their multimers of the present invention also include compounds in which at least some of the hydrogen atoms are replaced by deuterium or cyano, or by halogens such as fluorine or chlorine. Such compounds can be synthesized in the same manner as above by using raw materials in which the desired positions are deuterated, cyanated, fluorinated, or chlorinated.

<Polymer compounds, crosslinked polymers, pendant polymer compounds>
The polycyclic aromatic compound represented by formula (1) according to the present invention and its multimer can also 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, in the form of 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 a crosslinked polymer obtained by further crosslinking the polymer compound (the polymer compound for obtaining this crosslinked polymer has a crosslinkable substituent), or 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 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 described 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 or its multimer, substituents capable of further crosslinking the polymer compound thus obtained, and substituents capable of pendant reaction with a main-chain polymer, but are preferably those with the following structures. * in each structural formula indicates the 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. 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.

2-1. Organic electroluminescent device
2-1-1. Structure of Organic Electroluminescent Device FIG. 1 is a schematic cross-sectional view showing an organic EL device according to this embodiment.
The organic EL element 100 shown in FIG. 1 has a substrate 101, an anode 102 provided on the substrate 101, a hole injection layer 103 provided on the anode 102, a hole transport layer 104 provided on the hole injection layer 103, a light emitting layer 105 provided on the hole transport layer 104, an electron transport layer 106 provided on the light emitting layer 105, an electron injection layer 107 provided on the electron transport layer 106, and a cathode 108 provided on the electron injection layer 107.

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

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

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

2-1-2. 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. Inorganic compounds include, for example, 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. Organic compounds include, for example, polythiophenes such as poly(3-methylthiophene), conductive polymers such as polypyrrole and polyaniline. 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.

2-1-4. 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. For this purpose, it is preferable for the material to have a small ionization potential, a large hole mobility, and excellent stability, and to be unlikely to generate impurities that act as traps during manufacture and use.

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

It is also known that the electrical conductivity of organic semiconductors is strongly influenced by their doping. Such organic semiconductor matrix substances consist of compounds with good electron donating or accepting properties. For doping with electron donating substances, strong electron acceptors such as tetracyanoquinone dimethane (TCNQ) or 2,3,5,6-tetrafluorotetracyano-1,4-benzoquinone dimethane (F4TCNQ) are known (see, for example, the literature "M. Pfeiffer, A. Beyer, T. Fritz, K. Leo, Appl. Phys. Lett., 73(22), 3202-3204 (1998)" and the literature "J. Blochwitz, M. 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 hole injection layer material and the hole transport layer material described above can also be used as hole layer materials in the form of polymer compounds obtained by polymerizing a reactive compound substituted with a reactive substituent as a monomer, or crosslinked polymers thereof, or pendant polymer compounds obtained by reacting a main chain polymer with the reactive compound, or crosslinked pendant polymers thereof. In this case, the reactive substituent can be quoted from the description of the polycyclic aromatic compound represented by formula (1).
The applications of such polymer compounds and crosslinked polymers will be described in detail below.

<Formula (H) compound>
As the material for the hole injection layer and the material for the hole transport layer, for example, a compound represented by the following formula (H) can be suitably used.

In formula (H), one or more pairs of adjacent two or more of R ³¹ to R ³⁸ may form a substituted or unsubstituted saturated or unsaturated ring. R ³¹ to R ³⁸ that are not involved in ring formation are each independently hydrogen, a substituted or unsubstituted alkyl having 1 to 50 carbon atoms, a substituted or unsubstituted alkenyl having 2 to 50 carbon atoms, a substituted or unsubstituted alkynyl having 2 to 50 carbon atoms, a substituted or unsubstituted cycloalkyl having 3 to 50 ring carbon atoms, a substituted or unsubstituted alkoxy having 1 to 50 carbon atoms, a substituted or unsubstituted alkylthio having 1 to 50 carbon atoms, a substituted or unsubstituted aryloxy having 6 to 50 ring carbon atoms, a substituted or unsubstituted arylthio having 6 to 50 ring carbon atoms, a substituted or unsubstituted aralkyl having 7 to 50 carbon atoms, -Si(R ²⁰¹ )(R ²⁰² )(R ²⁰³ ), -C(═O)R ²⁰⁴ , -COOR ²⁰⁵ , halogen, cyano, nitro, a substituted or unsubstituted aryl having 6 to 50 ring carbon atoms, or a substituted or unsubstituted heterocyclic group having 5 to 50 ring atoms. R ²⁰¹ to R ²⁰⁵ are each independently hydrogen, a substituted or unsubstituted alkyl having 1 to 50 carbon atoms, a substituted or unsubstituted aryl having 6 to 50 ring carbon atoms, or a substituted or unsubstituted heterocyclic group having 5 to 50 ring atoms. When two or more R ²⁰¹ to R ²⁰⁵ are present, each of the two or more R ²⁰¹ to R ²⁰⁵ may be the same or different. L ²¹ to L ²⁴ are each independently a single bond, a substituted or unsubstituted alkylene having 1 to 50 carbon atoms, a substituted or unsubstituted arylene having 6 to 50 ring carbon atoms, or a substituted or unsubstituted divalent heterocyclic group having 5 to 50 ring atoms. Ar ²¹ and Ar ²² each independently represent a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms, or a substituted or unsubstituted heterocyclic group having 5 to 50 ring atoms.

In the description of the substituents in formula (H) in this specification, the "carbon number XX to YY" in the expression "a substituted or unsubstituted ZZ group having carbon numbers XX to YY" represents the number of carbon atoms when the ZZ group is unsubstituted, and does not include the number of carbon atoms of the substituent when it is substituted. Here, "YY" is greater than "XX", and "XX" and "YY" each represent an integer of 1 or more.

In the description of the substituents in formula (H) in this specification, the "atomic number XX to YY" in the expression "a substituted or unsubstituted ZZ group having atomic number XX to YY" represents the atomic number when the ZZ group is unsubstituted, and does not include the atomic number of the substituent when it is substituted. Here, "YY" is greater than "XX", and "XX" and "YY" each represent an integer of 1 or more.

In the case of "substituted or unsubstituted," "unsubstituted" means that it is not substituted with the aforementioned substituents and that a hydrogen atom is bonded to it.

In the description of the substituents in formula (H) in this specification, specific examples of each substituent include the following.
Examples of the unsubstituted alkyl having 1 to 50 carbon atoms (preferably 1 to 30, more preferably 1 to 18, and even more preferably 1 to 5) include methyl, ethyl, propyl, isopropyl, n-butyl, s-butyl, isobutyl, t-butyl, n-pentyl, n-hexyl, n-heptyl, and n-octyl.

Examples of the substituted alkyl having 1 to 50 carbon atoms (preferably 1 to 30, more preferably 1 to 18, and even more preferably 1 to 5) include hydroxymethyl, 1-hydroxyethyl, 2-hydroxyethyl, 2-hydroxyisobutyl, 1,2-dihydroxyethyl, 1,3-dihydroxyisopropyl, 2,3-dihydroxy-t-butyl, 1,2,3-trihydroxypropyl, chloromethyl, 1-chloroethyl, 2-chloroethyl, 2-chloroisobutyl, 1,2-dichloroethyl, 1,3-dichloroisopropyl, 2,3-dichloro-t-butyl, 1,2,3-trichloropropyl, bromomethyl, 1-bromoethyl, 2-bromoethyl, 2-bromoisobutyl, 1,2-dibromoethyl, 1,3-dibromoisopropyl, 2,3-dibromo-t-butyl, and 1,2,3-tribromopropyl. pyr, iodomethyl, 1-iodoethyl, 2-iodoethyl, 2-iodoisobutyl, 1,2-diiodoethyl, 1,3-diiodoisopropyl, 2,3-diiodo-t-butyl, 1,2,3-triiodopropyl, cyanomethyl, 1-cyanoethyl, 2-cyanoethyl, 2-cyanoisobutyl, 1,2-dicyanoethyl, 1,3-dicyanoisopropyl, 2,3-dicyano-t-butyl, 1,2,3-tricyanopropyl, nitromethyl, 1-nitroethyl, 2-nitroethyl, 2-nitroisobutyl, 1,2-dinitroethyl, 1,3-dinitroisopropyl, 2,3-dinitro-t-butyl, 1,2,3-trinitropropyl, 1-pyrrolylmethyl, 2-(1-pyrrolyl)ethyl, 1-hydroxy-2-phenylisopropyl, 1-chloro-2-phenylisopropyl, etc.

Examples of unsubstituted alkenyl having 2 to 50 carbon atoms (preferably 2 to 30, more preferably 2 to 18) include vinyl, allyl, 1-butenyl, 2-butenyl, 3-butenyl, 1,3-butadienyl, 1-methylvinyl, 1-methylallyl, 1,1-dimethylallyl, 2-methylallyl, 1,2-dimethylallyl, etc.

Examples of unsubstituted alkynyl groups having 2 to 50 carbon atoms (preferably 2 to 30, more preferably 2 to 18) include ethynyl.

Examples of unsubstituted cycloalkyl having 3 to 50 (preferably 3 to 30, more preferably 3 to 18, and even more preferably 3 to 6) ring carbon atoms include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, 4-methylcyclohexyl, 1-adamantyl, 2-adamantyl, 1-norbornyl, and 2-norbornyl.

Unsubstituted alkoxy having 1 to 50 carbon atoms (preferably 1 to 30, more preferably 1 to 18) is represented by -OX, where X is, for example, the above-mentioned alkyl having 1 to 50 carbon atoms.

Unsubstituted alkylthio having 1 to 50 carbon atoms (preferably 1 to 30, more preferably 1 to 18) is represented by -SX, where X is, for example, the above-mentioned alkyl having 1 to 50 carbon atoms.

Examples of the unsubstituted aryl having 6 to 50 (preferably 6 to 30, more preferably 6 to 18) ring carbon atoms include phenyl, 1-naphthyl, 2-naphthyl, 1-anthryl, 2-anthryl, 9-anthryl, 1-phenanthryl, 2-phenanthryl, 3-phenanthryl, 4-phenanthryl, 9-phenanthryl, 1-naphthacenyl, 2-naphthacenyl, 9-naphthacenyl, 1-pyrenyl, 2-pyrenyl, 4-pyrenyl, 2-biphenylyl, 3-biphenylyl, 4-biphenylyl, p-terphenyl-4-yl, p-terphenyl-3-yl, p-terphenyl-2-yl, m-terphenyl-4-yl, m-terphenyl-3-yl, and m-terphenyl-2-yl.
Of these, preferred are phenyl, naphthyl, biphenylyl, terphenyl, pyrenyl, phenanthryl and fluorenyl, and more preferred are phenyl, naphthyl, biphenylyl, terphenyl, pyrenyl and fluorenyl.

Examples of substituted aryls having 6 to 50 (preferably 6 to 30, more preferably 6 to 18) ring carbon atoms include o-tolyl, m-tolyl, p-tolyl, para-isopropylphenyl, meta-isopropylphenyl, ortho-isopropylphenyl, p-t-butylphenyl, meta-t-butylphenyl, ortho-t-butylphenyl, 3,4,5-trimethylphenyl, 4-phenoxyphenyl, 4-methoxyphenyl, 3,4-dimethoxyphenyl, 3,4,5-trimethoxyphenyl, 4-(phenylsulfanyl)phenyl, 4-(methylsulfanyl)phenyl, N',N'-dimethyl-N- Examples include phenyl, N',N'-dimethyl-N-phenyl, 2,6-dimethylphenyl, (2-phenylpropyl)phenyl, 3-methyl-2-naphthyl, 4-methyl-1-naphthyl, 4-methyl-1-anthryl, 4'-methylbiphenylyl, 4"-t-butyl-p-terphenyl-4-yl, 9,9-dimethylfluorenyl, 9,9-diphenylfluorenyl, 9,9'-spirobifluorenyl, 9,9-di(4-methylphenyl)fluorenyl, 9,9-di(4-isopropylphenyl)fluorenyl, 9,9-di(4-t-butylphenyl)fluorenyl, chrysenyl, and fluoranthenyl.

Examples of unsubstituted arylenes having 6 to 50 (preferably 6 to 30, more preferably 6 to 18) ring carbon atoms include divalent groups formed from aromatic hydrocarbon rings constituting the aryls having 6 to 50 ring carbon atoms exemplified above. Specifically, for example, divalent groups formed from phenyl include o-, m-, and p-phenylene, divalent groups formed from biphenyl include 2,4'-biphenylylene, 3,4'-biphenylylene, and 4,4'-biphenylylene, and divalent groups formed from naphthyl include naphthalene-1,2-diyl, naphthalene-1,3-diyl, naphthalene-1,4-diyl, naphthalene-1,5-diyl, naphthalene-1,6-diyl, naphthalene-1,7-diyl, naphthalene-1,8-diyl, naphthalene-2,3-diyl, naphthalene-2,6-diyl, and naphthalene-2,7-diyl.

Unsubstituted aryloxy having 6 to 50 (preferably 6 to 30, more preferably 6 to 18) ring carbon atoms is represented by -OY, and examples of Y include the above-mentioned aryl having 6 to 50 ring carbon atoms.

Unsubstituted arylthio having 6 to 50 (preferably 6 to 30, more preferably 6 to 18) ring carbon atoms is represented by -SY, where Y is, for example, the above-mentioned aryl having 6 to 50 ring carbon atoms.

Examples of unsubstituted aralkyls having 7 to 50 carbon atoms (preferably 7 to 30, more preferably 7 to 18) include benzyl, 1-phenylethyl, 2-phenylethyl, 1-phenylisopropyl, 2-phenylisopropyl, phenyl-t-butyl, α-naphthylmethyl, 1-α-naphthylethyl, 2-α-naphthylethyl, 1-α-naphthylisopropyl, 2-α-naphthylisopropyl, β-naphthylmethyl, 1-β-naphthylethyl, 2-β-naphthylethyl, 1-β-naphthylisopropyl, and 2-β-naphthylisopropyl.

Examples of substituted aralkyls having 7 to 50 carbon atoms (preferably 7 to 30, more preferably 7 to 18) include p-methylbenzyl, m-methylbenzyl, o-methylbenzyl, p-chlorobenzyl, m-chlorobenzyl, o-chlorobenzyl, p-bromobenzyl, m-bromobenzyl, o-bromobenzyl, p-iodobenzyl, m-iodobenzyl, o-iodobenzyl, p-hydroxybenzyl, m-hydroxybenzyl, o-hydroxybenzyl, p-nitrobenzyl, m-nitrobenzyl, o-nitrobenzyl, p-cyanobenzyl, m-cyanobenzyl, o-cyanobenzyl, etc.

Examples of unsubstituted heterocyclic groups having 5 to 50 (preferably 5 to 30, more preferably 5 to 18) ring atoms include pyrrolyl, pyrazinyl, pyridinyl, indolyl, isoindolyl, furyl, benzofuranyl, isobenzofuranyl, dibenzofuranyl, dibenzothienyl, quinolyl, isoquinolyl, quinoxalinyl, carbazolyl, phenanthridinyl, acridinyl, phenanthrolinyl, and thienyl, as well as pyridine ring, pyrazine ring, pyrimidine ring, pyridazine ring, triazine ring, indole ring, quinoline ring, acridine ring, pyrrolidine ring, dioxane ring, piperidine ring, morpholine ring, and the like. Examples of monovalent groups formed from a phosphorus ring, piperazine ring, carbazole ring, furan ring, thiophene ring, oxazole ring, oxadiazole ring, benzoxazole ring, thiazole ring, thiadiazole ring, benzothiazole ring, triazole ring, imidazole ring, benzimidazole ring, pyran ring, dibenzofuran ring, benzo[a]dibenzofuran ring, benzo[b]dibenzofuran ring and benzo[c]dibenzofuran ring, 1,3-benzodioxole ring, 2,3-dihydro-1,4-benzodioxine ring, phenanthro[4,5-bcd]furan ring, benzophenoxazine ring, etc.

Examples of unsubstituted divalent heterocyclic groups having 5 to 50 (preferably 5 to 30, more preferably 5 to 18) ring atoms include the groups exemplified above and divalent groups formed from heterocycles, etc.

Substituted or unsubstituted heterocyclic groups having 5 to 50 ring atoms also include the following groups. Divalent heterocyclic groups having 5 to 50 ring atoms also include the following groups which have been converted into divalent groups.
In the following formulae, * indicates the bonding position in the case of a monovalent group.

(In the formula, X _1A to X _6A and Y _1A to Y _6A each represents an oxygen atom, a sulfur atom, an -NZ- group, or an -NH- group. Z represents a substituted or unsubstituted aryl having 6 to 50 ring carbon atoms, a substituted or unsubstituted heterocyclic group having 5 to 50 ring atoms, or a substituted or unsubstituted alkyl having 1 to 50 carbon atoms. When two or more Zs are present, the two or more Zs may be the same or different.)

Halogen atoms include fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, etc.

In compound (H), the positional relationship on the benzene ring to which L ²³ and L ²⁴ are bonded may be ortho (o), meta (m) or para (p), preferably ortho or meta, and particularly preferably meta.

Here, the meaning of "one or more pairs of two or more adjacent groups among R ³¹ to R ³⁸ may form a substituted or unsubstituted saturated or unsaturated ring" in the compound represented by formula (H) will be explained.
"A pair of two or more adjacent groups among R ³¹ to R ³⁸ " is, for example, a combination of R ³¹ and ^R32 , R ³² and R ³³ , R ³³ and R ³⁴ , R ³⁴ and R ³⁵ , R ³⁵ and R ³⁶ , R ³⁶ and R ³⁷ , R ³⁷ and R ³⁸ , R ³¹ , R ³² and R ³³ , R ³² , R ³³ and R ³⁴ , etc.
The "substituted or unsubstituted" substituents for the saturated or unsaturated ring are as described below with respect to formula (H).
The term "saturated or unsaturated ring" means, for example, when R ³¹ and R ³² form a ring, a ring formed by the carbon atom to which R ³¹ is bonded, the carbon atom to which R ³² is bonded, and one or more arbitrary elements. Specifically, when R ³¹ and R ³² form a ring, when an unsaturated ring is formed by the carbon atom to which R ³¹ is bonded, the carbon atom to which R ³² is bonded, and four carbon atoms, the ring formed by R ³¹ and R ³² is a benzene ring.
The "arbitrary element" is preferably a C element, an N element, an O element, or an S element. When the arbitrary element is a C element or an N element, the bond not involved in the ring formation may be terminated with a hydrogen atom or the like.
The "one or more arbitrary elements" refers to preferably 2 or more and 15 or less, more preferably 3 or more and 12 or less, and even more preferably 3 or more and 5 or less arbitrary elements.

When a pair of R ³² , R ³³ , and R ³⁴ form a ring, the compound represented by formula (H) is, for example, a compound represented by the following formula (H-10). In addition, in the following formula (H-10), for example, when R ⁶¹ is phenyl, a pair of R ³² , R ³³ , and R ³⁴ forms a substituted ring.

[In formula (H-10), R ³¹ , R ³⁵ to R ³⁸ , L ²¹ to L ²⁴ , Ar ²¹ and Ar ²² are as defined in formula (H) above, and R ⁶¹ to R ⁶⁶ are the same as the substituents (any substituents of compound (H)) in the case of "substituted or unsubstituted" in compound (H) described below.]

The term "one or more pairs" means that, for example, R ³¹ and R ³² may form a ring, and R ³⁷ and R ³⁸ may simultaneously form a ring. In that case, the compound represented by formula (H) is, for example, a compound represented by the following formula (H-11). In addition, in the following formula (H-11), for example, when R ⁷¹ is phenyl, R ³¹ and R ³² form a substituted ring.

[In formula (H-11), R ³³ to R ³⁶ , L ²¹ to L ²⁴ , Ar ²¹ and Ar ²² are as defined in formula (H) above, and R ⁷¹ to R ⁷⁸ are the same as the substituents (any substituents of compound (H)) in the case of "substituted or unsubstituted" in compound (H) described below.]

In one embodiment, compound (H) preferably includes either or both of a compound represented by the following formula (Ha) and a compound represented by the following formula (Hb) (hereinafter referred to as compounds (H-a) and (H-b)).

[In formulae (Ha) and (Hb), R ³¹ to R ³⁸ , L ²¹ to L ²⁴ , Ar ²¹ and Ar ²² are as defined in formula (H).]

In one embodiment, at least one of L ²³ or L ²⁴ in compound (H) is a single bond.

In one embodiment, compound (H) is preferably compound (Ha), that is, L ²³ and L ²⁴ are each substituted at the meta position of the benzene ring.
In one embodiment, L ²⁴ in compound (H) is preferably a single bond.
In one embodiment, L ²³ in compound (H) is preferably a single bond.
In one embodiment, it is preferred that either one of Ar ²¹ and Ar ²² in compound (H) is a substituted or unsubstituted aryl having 6 to 50 ring carbon atoms, and the other is a substituted or unsubstituted aryl having 6 to 50 ring carbon atoms, or a substituted or unsubstituted heterocyclic group having 5 to 50 ring atoms.
In one embodiment, R ³¹ to R ³⁸ in compound (H) are preferably hydrogen atoms.

In one embodiment, compound (H) is a compound represented by the following formula (H-a-1) and/or the following formula (H-b-1):

[In formulas (H-a-1) and (H-b-1), R ³¹ to R ³⁸ , L ²¹ to L ²³ , Ar ²¹ and Ar ²² are as defined in formula (H).]

In one embodiment, compound (H) is a compound represented by the following formula (H-a-2) and/or the following formula (H-b-2):

[In formulas (H-a-2) and (H-b-2), R ³¹ to R ³⁸ , L ²¹ , L ²² , L ²⁴ , Ar ²¹ and Ar ²² are as defined in formula (H).]

In one embodiment, compound (H) is a compound represented by the following formula (H-a-3) and/or the following formula (H-b-3):

[In formulas (H-a-3) and (H-b-3), L ²¹ to L ²⁴ , Ar ²¹ and Ar ²² are as defined in formula (H).]

In one embodiment, compound (H) is one or more selected from the group consisting of compounds represented by the following formula (H-a-4) and compounds represented by the following formula (H-b-4).

[In formulas (H-a-4) and (H-b-4), L ²¹ , L ²² , L ²⁴ , Ar ²¹ and Ar ²² are as defined in formula (H).]

In one embodiment, compound (H) is a compound represented by the following formula (H-a-4):

[In formula (H-a-4), L ²¹ , L ²² , L ²⁴ , Ar ²¹ and Ar ²² are as defined in formula (H).]

In one embodiment, one of L ²³ and L ²⁴ in formula (H) is a single bond, and the other is a substituted or unsubstituted arylene having 6 to 50 ring carbon atoms.

Examples of the substituent in the case of "substituted or unsubstituted" in compounds (H), (H-a), (H-b), (H-a-1), (H-b-1), (H-a-2), (H-b-2), (H-a-3), (H-b-3), (H-a-4) and (H-b-4) (hereinafter also referred to as any substituent of compound (H)) include alkyl having 1 to 50 carbon atoms, alkenyl having 2 to 50 carbon atoms, alkynyl having 2 to 50 carbon atoms, cycloalkyl having 3 to 50 ring carbon atoms, alkoxy having 1 to 50 carbon atoms, alkylthio having 1 to 50 carbon atoms, aryloxy having 6 to 50 ring carbon atoms, arylthio having 6 to 50 ring carbon atoms, aralkyl having 7 to 50 carbon atoms, -Si(R ⁴¹ )(R ⁴² )(R ⁴³ ), -C(═O)R ⁴⁴ , -COOR ⁴⁵ , -S(=O)2R ⁴⁶ , -P(=O)(R ⁴⁷ )(R ⁴⁸ ), -Ge(R ⁴⁹ )(R ⁵⁰ )(R ⁵¹ ) (wherein R ⁴¹ to R ⁵¹ are each independently a hydrogen atom, an alkyl group having 1 to 50 carbon atoms, an aryl group having 6 to 50 ring carbon atoms, or a heterocyclic group having 5 to 50 ring atoms. When two or more R ⁴¹ to R ⁵¹ are present, each of the two or more R ⁴¹ to R ⁵¹ may be the same or different.), hydroxy, halogen, cyano, nitro, an aryl group having 6 to 50 ring carbon atoms, and a heterocyclic group having 5 to 50 ring atoms. Among these, alkyl groups having 1 to 50 carbon atoms, aryl groups having 6 to 50 ring carbon atoms, or heterocyclic groups having 5 to 50 ring atoms are preferred, and alkyl groups having 1 to 18 carbon atoms, aryl groups having 6 to 18 ring carbon atoms, or heterocyclic groups having 5 to 18 ring atoms are more preferred.

Specific examples of the substituents, optional substituents, and halogen atoms in these compounds (H) are the same as those described above, but the substituents and optional substituents in compounds (H) do not include substituted or unsubstituted amino. Therefore, in compounds (H), there is only one amino.
The compound represented by formula (H) is most preferably a compound represented by formula (H1).

In formula (H1), L ¹²¹ and L ¹²² are each independently a single bond or unsubstituted phenylene, L ¹²³ is unsubstituted phenylene, and Ar ¹²¹ and Ar ¹²² are each independently an unsubstituted phenyl or unsubstituted biphenylyl. L ¹²¹ and L ¹²² are each independently preferably a single bond or unsubstituted 1,4-phenylene, more preferably unsubstituted 1,4-phenylene. L ¹²³ is preferably unsubstituted 1,4-phenylene. ^{Ar 121} and Ar ¹²² are each independently preferably an unsubstituted phenyl or unsubstituted 4-biphenylyl or 3-biphenylyl, more preferably unsubstituted phenyl or unsubstituted 4-biphenylyl.

Examples of compounds represented by formula (H) include the following compounds:

2-1-5. Light-emitting layer in organic electroluminescent device The light-emitting layer 105 is a layer that emits light by recombining holes injected from the anode 102 and electrons injected from the cathode 108 between electrodes to which an electric field is applied. The material for forming the light-emitting layer 105 may be a compound (light-emitting compound) that is excited and emits light by recombination of holes and electrons, 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 compound of the present invention can be used as a material for the light-emitting layer. For example, a host material and a polycyclic aromatic compound represented by the above formula (1) or a multimer thereof as a dopant material can be used as a material for the light-emitting layer.

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

The amount of the host material used varies depending on the type of host material, and may be determined according to the characteristics of the host material. The amount of the host material used is preferably 50 to 99.999% by 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.

Examples of host materials include condensed ring derivatives such as anthracene, pyrene, dibenzochrysene, and fluorene, which have long been known as light emitters, bisstyryl derivatives such as bisstyrylanthracene derivatives and distyrylbenzene derivatives, tetraphenylbutadiene derivatives, and cyclopentadiene derivatives. In particular, anthracene-based compounds, fluorene-based compounds, and dibenzochrysene-based compounds are preferred.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Specific examples of "alkyl" include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, s-butyl, t-butyl, n-pentyl, isopentyl, neopentyl, t-pentyl, 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 "cycloalkyl" in the "optionally substituted cycloalkyl" in R ^{to R} include cycloalkyl having 3 to 24 carbon atoms, cycloalkyl having 3 to 20 carbon atoms, cycloalkyl having 3 to 16 carbon atoms, cycloalkyl having 3 to 14 carbon atoms, cycloalkyl having 5 to 10 carbon atoms, cycloalkyl having 5 to 8 carbon atoms, cycloalkyl having 5 to 6 carbon atoms, and cycloalkyl having 5 carbon atoms.

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

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

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

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

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

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

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

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

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

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

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

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

Specific examples of "tricycloalkylsilyl" include tricyclopentylsilyl and tricyclohexylsilyl.

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

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

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

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

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

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

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

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

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

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

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

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

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

Specific examples of anthracene compounds include compounds represented by the following formulas (3-1) to (3-123). In the structural formulas below, "Me" stands for methyl, "D" stands for deuterium, and "tBu" stands for t-butyl.

The anthracene compound represented by formula (3) can be produced by applying Suzuki coupling, Negishi ^{coupling, or other known coupling reactions using a compound having a reactive group at a desired position of the anthracene skeleton and a compound having a reactive group in a partial structure such as X, Ar 4} , and the structure of formula (A) as starting materials. Examples of reactive groups in these reactive compounds include halogens and boronic acids. As a specific production method, for example, the synthesis method in paragraphs [0089] to [0175] of WO 2014/141725 can be referred to.

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

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

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

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

Specific examples of heteroaryl include monovalent groups represented by removing any one hydrogen atom from the compounds of the following formula (4-Ar1), (4-Ar2), (4-Ar3), (4-Ar4), or (4-Ar5).

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

These heteroaryls may be bonded to the fluorene skeleton in formula (4) via a linking group. That is, the fluorene skeleton in formula (4) and the heteroaryl may be bonded directly or via a linking group. _Examples of the linking group include phenylene, biphenylene, naphthylene, anthracenylene, methylene, ethylene _{, -OCH2CH2- , -CH2CH2O-} , and _-OCH2CH2O- .

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

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

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

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

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

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

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

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

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

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

Specific examples of heteroaryl include monovalent groups represented by removing any one hydrogen atom from the compounds of the following formula (5-Ar1), (5-Ar2), (5-Ar3), (5-Ar4), or (5-Ar5).

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

These heteroaryls may be bonded to the dibenzochrysene skeleton in formula (5) via a linking group. That is, the dibenzochrysene skeleton in formula (5) and the heteroaryl may be bonded directly or via a linking group. Examples of the linking group include phenylene, biphenylene, naphthylene, anthracenylene, methylene, ethylene, _{-OCH2CH2- , -CH2CH2O- ,} and _{-OCH2CH2O- .}

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

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

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

The above-mentioned light-emitting layer materials (host material and dopant material) can be used as light-emitting layer materials in the form of polymer compounds obtained by polymerizing a reactive compound substituted with a reactive substituent as a monomer, or crosslinked polymers thereof, or pendant-type polymer compounds obtained by reacting a main-chain polymer with the reactive compound, or crosslinked pendant polymers thereof. In this case, the explanation of the polycyclic aromatic compound represented by formula (1) can be cited as the reactive substituent.
The applications of such polymer compounds and crosslinked polymers will be described in detail below.

<Examples of polymer host materials>

In formula (SPH-1),
Each MU is independently a divalent group represented by removing any two hydrogen atoms from an aromatic compound, each EC is independently a monovalent group represented by removing any one hydrogen atom from an aromatic compound, two hydrogen atoms in MU are replaced with EC or MU, and k is an integer from 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 (SPH-1) may be substituted with an alkyl group having 1 to 24 carbon atoms, a cycloalkyl group having 3 to 24 carbon atoms, a halogen atom or deuterium atom, and further, any -CH ₂ - in the alkyl group may be substituted with -O- or -Si(CH ₃ ) ₂ -, any -CH ₂ - in the alkyl group except for the -CH ₂ - directly bonded to EC in formula (SPH-1) may be substituted with an arylene group having 6 to 24 carbon atoms, and any hydrogen atom in the alkyl group may be substituted with fluorine.

Examples of MU include a divalent group represented by removing any two hydrogen atoms from any of the following compounds:

More specifically, examples include divalent groups represented by any of the following structures. In these, MU is bonded to another MU or EC at the *.

EC may be, for example, a monovalent group represented by any of the following structures. In these, EC is bonded to MU at *.

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

The uses of such polymer compounds and crosslinked polymers will be described in detail later.

2-1-6. 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. Metal complexes having electron-accepting nitrogen include, for example, hydroxyazole complexes such as hydroxyphenyloxazole complexes, azomethine complexes, tropolone metal complexes, flavonol metal complexes, and benzoquinoline metal complexes. These materials can be used alone or in combination with different materials.

Specific examples of other electron transfer compounds include borane derivatives, pyridine derivatives, naphthalene derivatives, fluoranthene derivatives, BO 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 metal complexes, quinoxaline derivatives, polymers of quinoxaline derivatives, benzazole compounds, gallium complexes, pyrazole derivatives, perfluorinated phenylene derivatives, and triazine derivatives. , pyrazine derivatives, benzoquinoline derivatives (such as 2,2'-bis(benzo[h]quinolin-2-yl)-9,9'-spirobifluorene), imidazopyridine derivatives, benzimidazole derivatives (such as tris(N-phenylbenzimidazol-2-yl)benzene), benzoxazole derivatives, thiazole 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, pyrimidine derivatives, arylnitrile derivatives, indole derivatives, phosphorus oxide derivatives, bisstyryl derivatives, silole derivatives and azoline 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, quinolinol-based metal complexes, thiazole derivatives, benzothiazole derivatives, silole derivatives and azoline derivatives are preferred.

<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.

Among the compounds represented by the above 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.

Specific examples of ^X1 include divalent groups represented by any of the following formulae (X-1) to (X-9).

（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。）

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

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

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

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

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

Specific examples of "alkyl" include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, s-butyl, t-butyl, n-pentyl, isopentyl, neopentyl, t-pentyl, 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.

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 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 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 "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.

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

Specific examples of the pyridine derivative include the following compounds:

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

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

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

Specific examples of the fluoranthene derivative include the following compounds.

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

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

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

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

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

Specific examples of the BO derivative include the following compounds.

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

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

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

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

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

The alkyl having 1 to 6 carbon atoms in R ¹ to R ⁴ may be either linear or branched. That is, it is a linear alkyl having 1 to 6 carbon atoms or a branched alkyl having 3 to 6 carbon atoms. It is more preferably an alkyl having 1 to 4 carbon atoms (branched alkyl having 3 to 4 carbon atoms). Specific examples include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, s-butyl, t-butyl, n-pentyl, isopentyl, neopentyl, t-pentyl, 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 "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 ...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 nyl-4-yl, o-terphenyl-2-yl, o-terphenyl-3-yl, o-terphenyl-4-yl, p-terphenyl-2-yl, p-terphenyl-3-yl, p-terphenyl-4-yl), fused tricyclic aryls anthracene-(1-,2-,9-)yl, acenaphthylene-(1-,3-,4-,5-)yl, fluorene-(1-,2-,3-,4-,9-)yl, phenalene-(1-,2-)yl, (1-,2-,3-,4-,9-)phenanthryl, fused tetracyclic aryls triphenylene-(1-,2-)yl, pyrene-(1-,2-,4-)yl, tetracene-(1-,2-,5-)yl, fused pentacyclic aryls perylene-(1-,2-,3-)yl, etc.

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

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

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

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

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

Specific examples of these anthracene derivatives include the following compounds.

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

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

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

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

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

Examples of the "cycloalkyl" in ^Ar2 include 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, pentacenyl, etc.

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 group, 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.

The aryl ether group 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 group is not particularly limited, but is usually in the range of 6 to 40.

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

Also, aryl refers to an aromatic hydrocarbon group such as phenyl, naphthyl, biphenylyl, phenanthryl, terphenylyl, or pyrenyl. Aryl may be unsubstituted or substituted. The number of carbon atoms in 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 the 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, still 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 the 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, still 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.

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

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

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

Specific examples of "aryl" include monocyclic aryl phenyl, bicyclic aryl (2-, 3-, 4-) biphenylyl, condensed bicyclic aryl (1-, 2-) naphthyl, tricyclic aryl terphenylyl (m-terphenyl-2'-yl, m-terphenyl-4'-yl, m-terphenyl-5'-yl, o-terphenyl-3'-yl, o-terphenyl-4'-yl, p-terphenyl-2'-yl, m-terphenyl-2-yl, m-terphenyl-3-yl, m-terphenyl-4-yl, o-terphenyl-2-yl, o-terphenyl-3-yl, o-terphenyl-4-yl, p-terphenyl-2-yl, p-terphenyl-3-yl, p-terphenyl-4-yl), condensed tricyclic aryl Examples of the 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, still 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 the above 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 the formulae (ETM-2-1) and (ETM-2-2) above 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 explained with reference to the above formula (ETM-2-1) or formula (ETM-2-2), and R ¹¹ to R ¹⁸ in each formula can be explained with reference to the above formula (ETM-2-1) or formula (ETM-2-2). In addition, in the above formula (ETM-2-1) or formula (ETM-2-2), two pyridine-based substituents are explained as being bonded together, but when these are replaced with benzimidazole-based substituents, both pyridine-based substituents may be replaced with benzimidazole-based substituents (i.e., n=2), or one of the pyridine-based substituents may be replaced with a benzimidazole-based substituent and the other pyridine-based substituent may be replaced with R ¹¹ to R ¹⁸ (i.e., n=1). Furthermore, for example, at least one of R ¹¹ to R ¹⁸ in the above formula (ETM-2-1) may be replaced with a benzimidazole-based substituent, and the "pyridine-based substituent" may be replaced with R ¹¹ to R ¹⁸ .

Specific examples of 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, and 5-(10-(naphthalen-2-yl)anthracen-9-yl)-1,2-diphenyl-1H-benzo[d]imidazole. , 1-(4-(10-(naphthalene-2-yl)anthracen-9-yl)phenyl)-2-phenyl-1H-benzo[d]imidazole, 2-(4-(9,10-di(naphthalene-2-yl)anthracen-2-yl)phenyl)-1-phenyl-1H-benzo[d]imidazole, 1-(4-(9,10-di(naphthalene-2-yl)anthracen-2-yl)phenyl)-2-phenyl-1H-benzo[d]imidazole, 5-(9,10-di(naphthalene-2-yl)anthracen-2-yl)-1,2-diphenyl-1H-benzo[d]imidazole, etc.

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

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

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

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

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

The alkyl, cycloalkyl and aryl in R ¹¹ to R ¹⁸ can be the same as those described for R ¹¹ to R ¹⁸ in formula (ETM-2). In addition to the above examples, φ can have the following structural 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 this 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.

<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 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 quinolinolate)aluminum, bis(2,4-dimethyl-8-quinolinolate)aluminum-μ-oxo-bis(2,4-dimethyl-8-quinolinolate)aluminum, bis(2-methyl-4-ethyl-8-quinolinolate)aluminum-μ-oxo-bis(2-methyl-4-ethyl-8-quinolinolate)aluminum, bis(2-methyl-4-methoxy-8-quinolinolate)aluminum-μ-oxo-bis(2-methyl-4-methoxy-8-quinolinolate)aluminum quinolinolate)aluminum, bis(2-methyl-5-cyano-8-quinolinolate)aluminum-μ-oxo-bis(2-methyl-5-cyano-8-quinolinolate)aluminum, bis(2-methyl-5-trifluoromethyl-8-quinolinolate)aluminum-μ-oxo-bis(2-methyl-5-trifluoromethyl-8-quinolinolate)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 the above formulas (ETM-2), (ETM-2-1), and (ETM-2-2) is replaced with the below-mentioned 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 explained with reference to the above formula (ETM-2-1) or formula (ETM-2-2), and R ¹¹ to R ¹⁸ in each formula can be explained with reference to the above formula (ETM-2-1) or formula (ETM-2-2). In addition, in the above formula (ETM-2-1) or formula (ETM-2-2), two pyridine-based substituents are explained as being bonded together, but when these are replaced with a thiazole-based substituent (or a benzothiazole-based substituent), both pyridine-based substituents may be replaced with a thiazole-based substituent (or a benzothiazole-based substituent) (i.e., n=2), or one of the pyridine-based substituents may be replaced with a thiazole-based substituent (or a benzothiazole-based substituent) and the other pyridine-based substituent may be replaced with R ¹¹ to R ¹⁸ (i.e., n=1). Furthermore, for example, at least one of R ¹¹ to R ¹⁸ in the above formula (ETM-2-1) may be replaced with a thiazole-based substituent (or a benzothiazole-based substituent) to replace the "pyridine-based substituent" with R ¹¹ to R ¹⁸ .

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

<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 (2) and formula (ETM-7-2) can be cited. In addition, alkenyloxy and alkynyloxy are groups in which the alkyl portion of an alkoxy is replaced with an alkenyl or alkynyl, respectively, and for details of these alkenyls and alkynyls, the explanations 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 explanation in formula (2) can be cited.

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 explanation in formula (2) 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 explanation in formula (2).

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, 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 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;
Y's are each 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, at least one hydrogen of Ar may be 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, R ¹ to R ⁵ are each independently hydrogen, an alkyl having 1 to 4 carbon atoms or a cycloalkyl having 5 to 10 carbon atoms, with the proviso that any one of Ar and R ¹ to R ⁵ in >N-Ar is a site bonded to L,
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.

Ｌは、ベンゼン、ピリジン、ピラジン、ピリミジン、ピリダジン、およびトリアジンからなる群から選択される環の２価の基であり、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２～１４のヘテロアリールで置換されていてもよく、
Ｙとしての＞Ｎ－ＡｒにおけるＡｒは、フェニル、ピリジニル、ピラジニル、ピリミジニル、ピリダジニル、およびトリアジニルからなる群から選択され、当該Ａｒ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のシクロアルキルまたは炭素数６～１０のアリールで置換されていてもよく、
Ｒ¹～Ｒ⁴はそれぞれ独立して水素、炭素数１～４のアルキルまたは炭素数５～１０のシクロアルキルであり、ただし、Ｒ¹とＲ²は同一であり、Ｒ³とＲ⁴は同一であり、またＲ¹～Ｒ⁴の全てが同時に水素になることはなく、そして、
ｍは２であり、アゾリン環とＬとで形成される基は同一である。なお、上記式（φ２－１）、式（φ２－３１）、式（φ２－３２）、式（φ２－３３）および式（φ２－３４）中の＊は結合位置を示す。 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 atom of φ may be substituted by 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. In the above formulae (φ2-1), (φ2-31), (φ2-32), (φ2-33) and (φ2-34), * indicates a bonding position.

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 explanation in formula (2) 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, more preferably Rb or Cs, and most preferably 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 represented by formula (1).
The applications of such polymer compounds and crosslinked polymers will be described in detail below.

2-1-7. 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 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 preferred. 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.

2-1-8. 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.

2-1-9. 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, or coating. 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. 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. It is generally preferable to set the vapor deposition conditions appropriately in 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 the wet film formation method, a coating film is generally formed through a coating process in which an organic layer forming composition is applied to a substrate and a drying process in which the solvent is removed from the applied organic layer forming composition. When the polymer compound has a crosslinkable substituent (also called a crosslinked polymer), the polymer is further crosslinked by the drying process to form a crosslinked polymer. Depending on the difference in the coating process, 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 form is called a spray method. The drying process includes air drying, heating, and drying under reduced pressure. The drying process may be performed only once, or may be performed multiple times using different methods and conditions. In addition, different methods may 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), fluoroalkylbenzenesulfonates, fluoroalkylcarboxylates, fluoroalkylpolyoxyethyleneethers, fluoroalkylammonium iodides, fluoroalkylbetaines, fluoroalkylsulfonates, diglycerol tetrakis (fluoroalkylpolyoxyethyleneether), fluoroalkyltrimethylammonium salts, fluoroalkylaminosulfonates, polyoxyethylene nonyl Examples of the alkyl ethers include phenyl ether, polyoxyethylene octylphenyl ether, polyoxyethylene alkyl ether, polyoxyethylene laurate, polyoxyethylene oleate, polyoxyethylene stearate, polyoxyethylene laurylamine, sorbitan laurate, sorbitan palmitate, sorbitan stearate, sorbitan oleate, sorbitan fatty acid esters, polyoxyethylene sorbitan laurate, polyoxyethylene sorbitan palmitate, polyoxyethylene sorbitan stearate, polyoxyethylene sorbitan oleate, polyoxyethylene naphthyl ether, alkyl benzene sulfonate, and alkyl diphenyl 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). Note that a coating film that is crosslinked in a network pattern and formed by applying a solution containing a polymer compound (crosslinkable polymer compound) and evaporating the solvent corresponds to the crosslinked polymer.

In formula (XLP-1),
MUx, ECx, and k are defined the same as MU, EC, and k in the above 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 compound 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 the substituents having the following structures are preferred. * in each structural formula indicates the 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 different types of monomer units (MU) in multiple stages and carrying out the reaction, it is possible to create a polymer with a concentration gradient in the monomer unit structure. In addition, after preparing the 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 2015/1458 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.

2-1-10. 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.). Examples of display methods include 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 are made up of 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.

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

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

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

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

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

Synthesis Example (1)
Synthesis of compound (1-1)

Under a nitrogen atmosphere, 2-chloro-6-bromoanisole (10 g) was dissolved in THF (50 mL) and cooled to -78°C. A n-butyllithium/n-hexane solution (1.6 M) was slowly added thereto. After stirring at the same temperature, 9-fluorenone (8.1 g) was added and further stirred. After the reaction, the reaction was stopped with saturated ammonium chloride, extracted with toluene, and purified by silica gel column chromatography to obtain intermediate A.

Under a nitrogen atmosphere, intermediate A (10 g) was dissolved in benzene (50 mL), boron trifluoride-diethyl ether complex (0.4 g) was added, and the mixture was heated to reflux. After the reaction, water was added to stop the reaction, and the organic layer was washed with water and separated. The mixture was then purified by silica gel column chromatography to obtain intermediate B.

Under a nitrogen atmosphere, intermediate B (10 g), sodium t-butoxide (6.3 g), and dichlorobis[(di-t-butyl(4-dimethylaminophenyl)phosphino)palladium (Pd-132, 0.18 g) as a palladium catalyst were dissolved in xylene (50 mL) and heated to reflux. After the reaction, the organic layer was washed with water, separated, and then purified by silica gel column chromatography to obtain intermediate C.

Under a nitrogen atmosphere, intermediate C (10 g) was dissolved in dichloromethane (50 mL) and cooled to 0°C, and then boron tribromide (6.3 g) was slowly added. After the reaction, water was added to stop the reaction, and the organic layer was washed with water, separated, and purified by silica gel column chromatography to obtain intermediate D.

Under a nitrogen atmosphere, intermediate D (9.0 g) was dissolved in pyridine (50 mL) and cooled to 0°C, after which trifluoromethanesulfonic anhydride was slowly added. After the reaction, water was added to stop the reaction, and toluene was added for liquid separation and extraction. Intermediate E was obtained by purifying the mixture using silica gel column chromatography.

Under a nitrogen atmosphere, cyclopentyl methyl ether (50 mL) was added to intermediate E (10 g), [1,1'-bis(diphenylphosphino)ferrocene]palladium(II) dichloride ( _PdCl2 (dppf), 0.12 g), potassium acetate (3.1 g), potassium carbonate ( _{4.4 g) and bispinacoldiboron (B2Pin2 ,} 4.8 g), and the mixture was heated to reflux. After the reaction, water was added to terminate the reaction, the mixture was separated and purified with a silica gel column to obtain intermediate F.

Under a nitrogen atmosphere, intermediate F (9 g) was dissolved in chlorobenzene (20 ml), and aluminum chloride (9.8 g) and N,N-diisopropylethylamine (DIPEA, 9.5 g) were added. After the reaction was completed, the reaction mixture was cooled to room temperature and poured into ice water, and toluene was added to extract the organic layer. The compound represented by formula (1-1) was obtained by purifying the mixture using a silica gel column.
EI-MS: m/z=493.
^1H -NMR ( _CDCl3 ): δ = 6.59 (d, 1H), 6.75 (d, 1H), 7.15 (m, 4H), 7.27-7.29 (m, 3H), 7.35-7.39 (m, 5H), 7.51-7.59 (m, 4H), 7.79 (d, 2H), 7.88 (dt, 2H), 8.44 (d, 1H), 8.52 (d, 1H)

Synthesis Example (2)
Synthesis of Compound (1-3) A compound represented by formula (1-3) was obtained using compound (F-3) in the same manner as in Synthesis Example (1).
EI-MS: m/z=605.
^1H -NMR ( _CDCl3 ): δ = 1.48 (s, 6H), 6.63 (d, 1H), 7.22-7.31 (m, 8H), 7.39 (m, 3H), 7.51-7.55 (m, 3H), 7.74 (d, 1H), 7.81 (d, 2H), 7.89 (d, 2H), 8.42 (d, 1H), 8.49 (d, 1H)

Synthesis Example (3)
Synthesis of Compound (1-23) A compound represented by formula (1-23) was obtained using compound (F-23) in the same manner as in Synthesis Example (1).
EI-MS: m/z=603.
^1H -NMR ( _CDCl3 ): δ = 1.48 (s, 6H), 6.60 (d, 1H), 7.00-7.02 (m, 2H), 7.29-7.33 (m, 4H), 7.40 (m, 2H), 7.48 ( d, 2H), 7.56 (dt, 1H), 7.80 (d, 2H), 7.89 (d, 2H), 8.20 (s, 1H), 8.35 (m, 2H), 8.42 (d, 1H)

Synthesis Example (4)
Synthesis of Compound (1-83) A compound represented by formula (1-83) was obtained using compound (F-83) in the same manner as in Synthesis Example (1).
EI-MS: m/z=621.
^1H -NMR ( _CDCl3 ): δ = 1.49 (s, 6H), 6.63 (d, 1H), 7.01 (dt, 2H), 7.14-7.19 (m, 8H), 7.32 (dt, 2H), 7 .39 (m, 3H), 7.58 (dt, 1H), 7.73 (d, 1H), 7.82 (d, 2H), 8.42 (d, 1H), 8.49 (d, 1H)

Synthesis Example (5)
Synthesis of Compound (1-103) A compound represented by formula (1-103) was obtained using compound (F-103) in the same manner as in Synthesis Example (1).
EI-MS: m/z=619.
^1H -NMR ( _CDCl3 ): δ = 1.45 (s, 6H), 6.61 (d, 1H), 6.99-7.03 (m, 3H), 7.13-7.22 (m, 5H), 7.31 (dt, 2H) , 7.41 (m, 2H), 7.55 (dt, 1H), 7.80 (d, 2H), 7.89 (m, 2H), 8.21 (s, 1H), 8.45 (d, 1H)

Synthesis Example (5-1)
Synthesis of compound (H1-1)

Compound (H1-1) was synthesized according to the method described in WO 2017/024703.

Synthesis Example (5-2)
Synthesis of compound (H1-2)

Compound (H1-2) was synthesized according to the method described in WO 2017/061480.

Comparative compound-1 was synthesized according to the method described in WO 2015/102118.

By appropriately changing the raw material compounds, other compounds of the present invention can be synthesized in a manner similar to the above synthesis examples.

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

<Evaluation of deposition type organic EL elements>
Organic EL elements according to Examples 1 to 19 and Comparative Examples 1 to 4 were prepared, and the characteristics at 1000 cd/ ^m2 emission, namely voltage (V), emission wavelength (nm), and external quantum efficiency (%), were measured. Next, the time during which the element maintained a luminance of 90% or more of the initial luminance when driven at a constant current density of 10 mA/ ^cm2 was measured.

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

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

<Examples 1 to 21, Comparative Examples 1 and 2>
The material configurations of the layers in the organic EL elements according to Examples 1 to 21 and Comparative Examples 1 and 2 are shown in Table 1 below.

In Table 1, (HI) is N ⁴ ,N ^4' -diphenyl-N ⁴ ,N ^4' -bis(9-phenyl-9H-carbazol-3-yl)-[1,1'-biphenyl]-4,4'-diamine, (HAT-CN) is 1,4,5,8,9,12-hexaazatriphenylene hexacarbonitrile, (HT-1) is N-([1,1'-biphenyl]-4-yl-9,9-dimethyl-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl)-9H-fluoren-2-amine[1,1'-biphenyl]-4-amine, (HT-2) is N,N-bis(4-(dibenzo[b,d]furan-4-yl)phenyl)-[1,1':4',1"-terphenyl]-4-amine, (BH-1) is 2-(10-phenylazaphenyl)-4-yl-9,9-dimethyl-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-4-amine, (BH-2) is N,N-bis(4-(dibenzo[b,d]furan-4-yl)phenyl)-[1,1':4',1"-terphenyl]-4-amine, (BH-1) is 2-(10-phenylanthracen-9-yl) naphtho[2,3-b]benzofuran, (BH-2) is 2-(10-phenylanthracen-9-yl) dibenzo[b,d]furan, (BH-3) is 9-([2,2'-binaphthalene]-7-yl)-10-phenylanthracene, (ET-1) is 9,9'-(5-(6-(1,1'-biphenyl)-4-yl)-2-phenylpyrimidin-4-yl)-1,3-phenylene]bis(9H-carbazole), and (ET-2) is 2,2'-[(2-phenylanthracen-9,10-diyl) dibenzene-4,1-diyl] dipyridine. The chemical structures are shown below together with "Liq" and "Comparative Compound-1".

Example 1
A 26 mm × 28 mm × 0.7 mm glass substrate (manufactured by Optoscience Co., Ltd.) on which an ITO film having a thickness of 180 nm was formed by sputtering and polished to 150 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, HAT-CN, HT-1, H1-1, BH-1, compound (1-1), ET-1, and ET-2, and an aluminum nitride deposition boat containing Liq, LiF, and aluminum, were attached.

The following layers are formed in sequence on the ITO film of the transparent support substrate. The vacuum chamber is depressurized to 5×10 ⁻⁴ Pa, and first, HI is heated and evaporated to a thickness of 40 nm, then HAT-CN is heated and evaporated to a thickness of 5 nm, then HT-1 is heated and evaporated to a thickness of 45 nm, then H1-1 is heated and evaporated to a thickness of 10 nm to form a hole layer consisting of four layers. Next, BH-1 and compound (1-1) are heated simultaneously and evaporated to a thickness of 25 nm to form a light-emitting layer. The evaporation rate was adjusted so that the mass ratio of BH-1 to compound (1-1) was approximately 98:2. Furthermore, ET-1 was heated and evaporated to a thickness of 5 nm, and then ET-2 and Liq were heated simultaneously and evaporated to a thickness of 25 nm to form an electronic layer consisting of two layers. The evaporation rate was adjusted so that the mass ratio of ET-2 to Liq was approximately 50:50. The deposition rate of each layer was 0.01 to 1 nm/sec. Then, LiF was heated and deposited at a deposition rate of 0.01 to 0.1 nm/sec to a thickness of 1 nm, and then aluminum was heated and deposited to a thickness of 100 nm to form a cathode, thereby obtaining an organic EL element.

A direct current voltage was applied between the ITO electrode as the anode and the LiF/aluminum electrode as the cathode, and the characteristics at 1000 cd/m ² emission were measured, and the time for which 90% or more of the initial luminance was maintained was also measured.

A direct current voltage was applied to the ITO electrode as the anode and the LiF/aluminum electrode as the cathode, and the characteristics at 1000 cd/ ^m2 light emission were measured. As shown in Table 1, the driving voltage was 3.72 V, the external quantum efficiency was 7.65%, and the time for which 90% or more of the initial luminance was retained was 132 hours.

<Examples 2 to 21>
According to Example 1, each organic EL element was manufactured with the layer structure shown in Table 1, and the EL characteristic data was measured (Table 2).

<Comparative Examples 1 and 2>
According to Example 1, each organic EL element was manufactured with the layer structure shown in Table 1, and the EL characteristic data was measured (Table 2).

As shown by the above measurement results, it was confirmed that high external quantum efficiency and long life were achieved in an organic EL element having an emission layer using the compound of the present invention as a dopant.

The present invention provides a novel polycyclic aromatic compound or a multimer thereof having a spiro structure. The present invention can increase the options for materials for organic devices, such as materials for organic EL elements. In addition, by using the polycyclic aromatic compound or a multimer thereof of the present invention as a material for organic EL elements, it is possible to provide, for example, an organic EL element having excellent luminous efficiency and element life, a display device including the same, and a lighting device including the same.

REFERENCE SIGNS LIST 100 Organic electroluminescent element 101 Substrate 102 Anode 103 Hole injection layer 104 Hole transport layer 105 Light-emitting layer 106 Electron transport layer 107 Electron injection layer 108 Cathode

Claims (18)

A polycyclic aromatic compound represented by the following formula (1):
(In formula (1),
ring A, ring B and ring C each independently represent an aryl ring or a heteroaryl ring, and at least one hydrogen atom in these rings may be substituted;
^Y1 is B;
One of X ¹ is a group represented by formula (1a), and the other is >O, >N-R, or >S;
In formula (1a),
ring D and ring E are each independently a benzene ring, and at least one hydrogen atom in these rings may be substituted;
^X2 is a single bond, >O, >N--R, >C(--R) ₂ , -C(--R) ₂ --C(--R) _2- , >S, or >Si(--R) ₂ ;
* indicates the bond position.
Each R in the >N-R is independently an optionally substituted aryl or an optionally substituted heteroaryl;
R in the above >C(-R) ₂ , -C(-R) ₂ -C(-R) ₂ - and >Si(-R) ₂ is each independently hydrogen, an optionally substituted aryl, an optionally substituted alkyl or an optionally substituted cycloalkyl;
>N- ^R as X1 may be bonded to one ring selected from the group consisting of ring A, ring B, and ring C in R via -O-, -S-, or a single bond, and may form a phenoxazine ring, a phenothiazine ring, or a carbazole ring together with the bonded ring ;
In the compound or structure represented by formula (1), at least one selected from the group consisting of aryl rings and heteroaryl rings may be condensed with at least one cycloalkane;
At least one hydrogen in the cycloalkane may be replaced; and
At least one -CH ₂ - in the cycloalkane may be replaced by -O-;
At least one hydrogen atom in the compound or structure represented by formula (1) may be replaced with deuterium. The polycyclic aromatic compound according to claim 1, wherein the A ring, the B ring, and the C ring are each independently a benzene ring, a naphthalene ring, a benzofuran ring, or a benzothiophene ring, the D ring and the E ring are each independently a benzene ring, and at least one hydrogen atom in the benzene ring, the naphthalene ring, the benzofuran ring, or the benzothiophene ring may be substituted with a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted diarylamino, a substituted or unsubstituted diheteroarylamino, a substituted or unsubstituted arylheteroarylamino, a substituted or unsubstituted diarylboryl (two aryls may be bonded via a single bond or a linking group), a substituted or unsubstituted alkyl, a substituted or unsubstituted cycloalkyl, a substituted or unsubstituted alkoxy, a substituted or unsubstituted aryloxy, or a substituted silyl. The polycyclic aromatic compound according to claim 1 or 2, which is represented by the following formula (2):
(In formula (2),
^Y1 is B,
One of X ¹ is a group represented by formula (2a), and the other is >O, >N—R, or >S;
In formula (2a),
^X2 is a single bond, >O, >N--R, >C(--R) ₂ , -C(--R) ₂ --C(--R) _2- , >S, or >Si(--R) ₂ ;
* indicates the bond position.
In formula (2) and formula (2a),
R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ , R ¹⁰ , R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁵ , R ¹⁶ , R ¹⁷ , R ¹⁸ and R ¹⁹ 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, trialkylsilyl, tricycloalkylsilyl, dialkylcycloalkylsilyl or alkyldicycloalkylsilyl, at least one hydrogen atom of which may be substituted by aryl, heteroaryl, alkyl or cycloalkyl; R in the >N-R is each independently an optionally substituted aryl or an optionally substituted heteroaryl;
R in the above >C(-R) ₂ , -C(-R) ₂ -C(-R) ₂ - and >Si(-R) ₂ is each independently hydrogen, an optionally substituted aryl, an optionally substituted alkyl or an optionally substituted cycloalkyl;
>N-R in X1 ^may be bonded to one ring selected from the group consisting of ring a, ring b, and ring c in R via -O-, -S-, or a single bond, and may form a phenoxazine ring, a phenothiazine ring, or a carbazole ring together with the bonded ring ;
In the compound or structure represented by formula (2), at least one selected from the group consisting of an aryl ring and a heteroaryl ring may be condensed with at least one cycloalkane having 3 to 24 carbon atoms, at least one hydrogen in the cycloalkane may be substituted with an aryl having 6 to 30 carbon atoms, a heteroaryl having 2 to 30 carbon atoms, an alkyl having 1 to 24 carbon atoms, or a cycloalkyl having 3 to 24 carbon atoms, and at least one -CH ₂ - in the cycloalkane may be substituted with -O-,
At least one hydrogen atom in the compound or structure represented by formula (2) may be replaced with deuterium. The polycyclic aromatic compound according to any one of claims 1 to 3, wherein the other X ¹ is >N-R. The polycyclic aromatic compound according to claim 4, wherein ^X2 is a single bond. 5. The polycyclic aromatic compound according to claim 1, wherein ^X2 is >O, >N--R, >C(--R) ₂ , -C(--R) ₂ -C(--R) _2- , >S, or >Si(--R) ₂ . The polycyclic aromatic compound according to claim 1, represented by any one of formulas (1-1), (1-3), (1-21), (1-23), (1-41), (1-61), (1-83), and (1-103).
A material for organic devices containing the polycyclic aromatic compound according to any one of claims 1 to 7. The material for organic devices according to claim 8, wherein the material for organic devices is a material for organic electroluminescent elements, a material for organic field effect transistors, or a material for organic thin-film solar cells. The material for organic devices according to claim 9, wherein the material for organic electroluminescent elements is a material for light-emitting layers. An organic electroluminescence device having 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 claims 1 to 7. An organic electroluminescence device having a pair of electrodes consisting of an anode and a cathode, and a light-emitting layer disposed between the pair of electrodes and containing the polycyclic aromatic compound according to any one of claims 1 to 7. The organic electroluminescent device according to claim 12, wherein the light-emitting layer contains a host and the polycyclic aromatic compound as a dopant. The organic electroluminescent device according to claim 13, 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 12 to 14, which has an electron transport layer and/or 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, quinolinol-based metal complexes, thiazole derivatives, benzothiazole derivatives, silole derivatives, and azoline derivatives. The organic electroluminescence device according to claim 15, wherein the electron transport layer and/or 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 comprising the organic electroluminescent element according to any one of claims 11 to 16. A lighting device comprising the organic electroluminescent element according to any one of claims 11 to 16.