KR20210019987A - Electron transport material or electron injection material containing alkyl-substituted polycyclic aromatic compounds - Google Patents

Abstract

By introducing an alkyl group at a specific position (specifically, an ortho position) of a polycyclic aromatic compound in which a plurality of aromatic rings are connected with a boron atom and an oxygen atom, etc., a compound suitable for an electron transport material is provided, for example, luminous efficiency and device Provides an organic EL device with excellent life.

Description

Electron transport material or electron injection material containing alkyl-substituted polycyclic aromatic compounds

The present invention relates to an electron transport material or electron injection material (hereinafter collectively referred to as ``electron transport material'') containing an alkyl-substituted polycyclic aromatic compound and its multimer (hereinafter, collectively referred to as ``polycyclic aromatic compound''), and , To an organic electroluminescent device using the same, and a display device and a lighting device. In addition, in this specification, the "organic electroluminescent element" may be referred to as "organic EL element" or simply "element".

BACKGROUND ART Conventionally, a display device using an electroluminescent light emitting element has been studied in various ways in that power saving or thinning is possible, and an organic electroluminescent element made of an organic material is actively studied in that it is easy to reduce weight or increase in size. Has been. In particular, for the development of organic materials having luminescence properties such as blue, which is one of the three primary colors of light, and development of organic materials having the ability to transport charges such as holes and electrons (having the possibility of becoming a semiconductor or superconductor), polymer compounds , Regardless of the low molecular weight compound, it has been actively studied so far.

The organic EL device has a structure comprising a pair of electrodes consisting of an anode and a cathode, and one layer or a plurality of layers which are disposed between the pair of electrodes and contain an organic compound. The layer containing the organic compound includes a light emitting layer, a charge transport/injection layer for transporting or injecting charges such as holes and electrons, and various organic materials suitable for these layers have been developed.

As the material for the light emitting layer, for example, a benzofluorene-based compound has been developed (International Publication No. 2004/061047). In addition, as a hole transport material, for example, triphenylamine compounds have been developed (Japanese Patent Laid-Open No. 2001-172232). In addition, as electron transport materials, for example, anthracene-based compounds have been developed (Japanese Patent Laid-Open No. 2005-170911).

In addition, in recent years, as a material for use in organic EL devices and organic thin-film solar cells, materials having improved triphenylamine derivatives have also been reported (International Publication No. 2012/118164). This material refers to N,N'-diphenyl-N,N'-bis(3-methylphenyl)-1,1'-biphenyl-4,4'-diamine (TPD), which was already in practical use, and It is a material characterized in that the planarity is improved by connecting aromatic rings constituting phenylamine. In this document, for example, the charge transport properties of the NO-linked compound (compound 1 on page 63) are evaluated, but the method for producing materials other than the NO-linked compound is not described, and the element to be linked is If they are different, since the electronic state of the whole compound is different, properties obtained from materials other than the NO-linked compound are not yet known. Examples of such compounds can be found elsewhere (International Publication No. 2011/107186). For example, a compound having a conjugated structure having a large triplet exciton energy (T1) is advantageous as a material for a blue light-emitting layer because it can emit phosphorescence of a shorter wavelength. Further, a compound having a novel conjugated structure having a large T1 is required as an electron transport material or a hole transport material interposed between the light emitting layer.

Patent Document 1: International Publication No. 2004/061047 Patent Document 2: Japanese Patent Laid-Open No. 2001-172232 Patent Document 3: Japanese Patent Laid-Open No. 2005-170911 Patent Document 4: International Publication No. 2012/118164 Patent Document 5: International Publication No. 2011/107186 Patent Document 6: International Publication No. 2015/102118

As described above, various materials have been developed as materials used for organic EL devices, but in order to increase the choice of materials for organic EL devices, development of materials made of compounds different from those of the prior art is required. In particular, organic EL properties obtained from materials other than the NO-linked compound reported in Patent Documents 1 to 4 and a method for producing the same are not yet known.

Further, in Patent Document 6, a polycyclic aromatic compound containing boron and an organic EL device using the same are reported, but in order to further improve device characteristics, an electron transport material capable of improving luminous efficiency and device life is required.

In order to solve the above problems, the inventors of the present invention have conducted intensive studies to solve the above problems. As a result, an electron transporting layer containing a polycyclic aromatic compound having an alkyl group introduced at a specific position (specifically, an ortho position) is disposed between a pair of electrodes, for example, organic By configuring the EL element, it was found that an excellent organic EL element can be obtained, and the present invention was completed. That is, the present invention provides an electron transport material for an organic EL device containing the following alkyl-substituted polycyclic aromatic compounds or a multimer thereof.

In addition, in the present specification, a chemical structure or a substituent may be represented by carbon number, but the number of carbon atoms in a case where a substituent is substituted in a chemical structure or a substituent is further substituted on a substituent is the number of carbon atoms of each chemical structure or substituent. It means, and does not mean the total carbon number of a chemical structure and a substituent, or the total carbon number of a substituent and a substituent. For example, ``the substituent B of the carbon number Y substituted with the substituent A of the carbon number X'' means that the ``the substituent A of the carbon number X'' is substituted with the ``the substituent B of the carbon number Y'', and the carbon number Y is the substituent A and the substituent It is not the number of carbon atoms in the sum of B. In addition, for example, ``substituent B of carbon number Y substituted with substituent A'' means that ``substituent A'' is substituted with ``substituent B of carbon number Y'', and the number of carbons Y represents substituent A and It is not the total number of carbon atoms of the substituent B.

Clause 1.

An electron transport material or an electron injection material containing a polycyclic aromatic compound represented by the following general formula (1) or a multimer of a polycyclic aromatic compound having a plurality of structures represented by the following general formula (1).

(In the above formula (1),

A ring, B ring, and C ring are each independently an aryl ring or a heteroaryl ring, and at least one hydrogen in these rings may be substituted,

Y ¹ is B, P, P=O, P=S, Al, Ga, As, Si-R or Ge-R, and R of Si-R and Ge-R is aryl, alkyl or cycloalkyl,

X ¹ and X ² are each independently >O, >NR, >C(-R) ₂ , >S or >Se, and R in >NR is an optionally substituted aryl, optionally substituted heteroaryl, or substituted Alkyl which may be substituted or cycloalkyl which may be substituted _{, R of >C(-R) 2} is hydrogen, aryl which may be substituted, alkyl which may be substituted, or cycloalkyl which may be substituted, and R of >NR and/or R of >C(-R) ₂ may be bonded to at least one of the A ring, B ring and C ring by a linking group or a single bond,

At least one hydrogen in the compound or structure represented by formula (1) may be substituted with deuterium, cyano, or halogen, and,

At least one hydrogen in the compound or structure represented by formula (1) is substituted with a group represented by the general formula (oR),

In the formula (oR), R ²¹ is alkyl, R ²² to R ²⁵ are each independently hydrogen, aryl, heteroaryl, alkyl or cycloalkyl, and ^{adjacent groups in R 22} to R ²⁵ are bonded to each other to form a benzene ring and Together, an aryl ring or heteroaryl ring may be formed, at least one hydrogen in the formed ring may be substituted with aryl, heteroaryl, alkyl or cycloalkyl, and the group represented by the formula (oR) is * It is substituted with at least one hydrogen in the compound or structure represented by the above formula (1).)

Item 2.

In the above formula (1),

Ring A, Ring B, and Ring C are each independently an aryl ring or a heteroaryl ring, and at least one hydrogen in these rings is 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 through a single bond or a linking group), substituted Or may be substituted with unsubstituted alkyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted alkoxy, or substituted or unsubstituted aryloxy, and these rings are composed of ^{Y 1} , X ¹ and X ² It has a 5-membered ring or a 6-membered ring that shares a bond with the condensed bicyclic structure of the above formula,

Y ¹ is B, P, P=O, P=S, Al, Ga, As, Si-R or Ge-R, and R of Si-R and Ge-R is aryl, alkyl or cycloalkyl,

X ¹ and X ² are each independently >O, >NR, >C(-R) ₂ , >S, or >Se, and R of >NR is an aryl, alkyl or cyclo optionally substituted with alkyl or cycloalkyl. Heteroaryl, alkyl or cycloalkyl which may be substituted with alkyl, and _{R of >C(-R) 2} is an aryl, alkyl or cycloalkyl which may be substituted with hydrogen, alkyl or cycloalkyl, and the> R of NR and/or R of >C(-R) ₂ is -O-, -S-, -C(-R) ₂ -or at least one of ring A, ring B, and ring C by a single bond May be bonded to a dog, and _{R of -C(-R) 2} -is hydrogen, alkyl or cycloalkyl,

At least one hydrogen in the compound or structure represented by formula (1) may be substituted with deuterium, cyano, or halogen,

In the case of a multimer, it is a 2 or trimer having 2 or 3 structures represented by general formula (1), and,

At least one hydrogen in the compound or structure represented by formula (1) is substituted with a group represented by the general formula (oR),

In the formula (oR), R ²¹ is an alkyl having 1 to 24 carbon atoms, and R ²² to R ²⁵ are each independently hydrogen, aryl having 6 to 30 carbon atoms, heteroaryl having 2 to 30 carbon atoms, alkyl having 1 to 24 carbon atoms Or a cycloalkyl having 3 to 24 carbon atoms, and ^{adjacent groups among R 22} to R ²⁵ may be bonded to each other to form an aryl ring having 9 to 16 carbon atoms or a heteroaryl ring having 6 to 15 carbon atoms together with a benzene ring. At least one hydrogen in may be substituted with a C6-C30 aryl, a C2-C30 heteroaryl, a C1-C24 alkyl, or a C3-C24 cycloalkyl, by the above formula (oR). The group represented by * is substituted with at least one hydrogen in the compound or structure represented by the formula (1),

The electron transport material or electron injection material according to item 1.

Clause 3.

The electron transport material or electron injection material according to item 1, wherein the polycyclic aromatic compound is represented by the following general formula (2).

(In the above formula (2),

R ¹ to R ¹¹ are each independently hydrogen, aryl, heteroaryl, diarylamino, diheteroarylamino, arylheteroarylamino, diarylboryl (two aryls may be bonded through a single bond or a linking group), Alkyl, cycloalkyl, alkoxy or aryloxy, and at least one hydrogen in these may be substituted with aryl, heteroaryl, alkyl or cycloalkyl, and ^{adjacent groups among R 1} to R ¹¹ are bonded to each other. An aryl ring or heteroaryl ring may be formed together with the a ring, b ring or c ring, and at least one hydrogen in the formed ring is aryl, heteroaryl, diarylamino, diheteroarylamino, arylheteroarylamino, Diarylboryl (two aryls may be bonded through a single bond or a linking group), alkyl, cycloalkyl, alkoxy or aryloxy may be substituted, and at least one hydrogen in these may be aryl, heteroaryl, alkyl Or it may be substituted with cycloalkyl,

Y ¹ is B, P, P=O, P=S, Al, Ga, As, Si-R or Ge-R, wherein R of Si-R and Ge-R is an aryl having 6 to 12 carbon atoms, 1 carbon number ~6 alkyl or C3-C14 cycloalkyl,

X ¹ and X ² are each independently >O, >NR, >C(-R) ₂ , >S or >Se, wherein R of >NR is a C6-C12 aryl, a C2-C15 heteroaryl , C1-C6 alkyl or C3-C14 cycloalkyl, wherein _{R of >C(-R) 2} is hydrogen, C6-C12 aryl, C1-C6 alkyl or C3-C14 cyclo Alkyl, and R of >NR and/or R of >C(-R) ₂ are -O-, -S-, -C(-R) ₂ -or by a single bond, the ring a, b May be bonded to at least one of a ring and a c ring, and _{R of -C(-R) 2} -is an alkyl having 1 to 6 carbon atoms or a cycloalkyl having 3 to 14 carbon atoms,

At least one hydrogen in the compound represented by formula (2) may be substituted with deuterium, cyano or halogen, and,

The group represented by the general formula (oR) is bonded to at least one of the a ring, b ring, c ring, and the aryl ring and heteroaryl ring formed together with these rings in *,

In the above formula (oR), R ²¹ is alkyl having 1 to 12 carbon atoms, and R ²² to R ²⁵ are each independently hydrogen, aryl having 6 to 16 carbon atoms, heteroaryl having 2 to 20 carbon atoms, alkyl having 1 to 12 carbon atoms Or a cycloalkyl having 3 to 16 carbon atoms, and ^{adjacent groups among R 22} to R ²⁵ may be bonded to form a naphthalene ring, a phenanthrene ring, a fluorene ring or a carbazole ring together with a benzene ring, and in the formed ring At least one hydrogen of may be substituted with a C6-C16 aryl, a C2-C20 heteroaryl, a C1-C12 alkyl, or a C3-C16 cycloalkyl.)

Item 4.

In the above formula (2),

R ¹ to R ¹¹ are each independently hydrogen, aryl having 6 to 30 carbon atoms (this aryl may be substituted with heteroaryl having 2 to 15 carbon atoms), heteroaryl having 2 to 30 carbon atoms, diarylamino (however, aryl Is aryl having 6 to 12 carbon atoms), diaryl boryl (however, aryl is an aryl having 6 to 12 carbon atoms, and two aryls may be bonded through a single bond or a linking group), alkyl having 1 to 24 carbon atoms, or 3 carbon atoms It is a cycloalkyl of ~24, and ^{adjacent groups among R 1} ~ R ¹¹ are bonded to form an aryl ring having 9 to 16 carbon atoms or a heteroaryl ring having 6 to 15 carbon atoms together with the a ring, b ring or c ring, May be present, and at least one hydrogen in the formed ring is aryl having 6 to 30 carbon atoms (this aryl may be substituted with heteroaryl having 2 to 15 carbon atoms), heteroaryl having 2 to 30 carbon atoms, diarylamino ( However, aryl is an aryl having 6 to 12 carbon atoms), diaryl boryl (however, aryl is an aryl having 6 to 12 carbon atoms, and two aryls may be bonded through a single bond or a linking group), alkyl having 1 to 24 carbon atoms Or it may be substituted with a C3-C24 cycloalkyl,

Y ¹ is B, P, P=O, P=S or Si-R, and R of Si-R is a C6-C10 aryl, C1-C4 alkyl, or C5-C10 cycloalkyl,

X ¹ and X ² are each independently >O, >NR, >C(-R) ₂ or >S, and R of >NR is an aryl having 6 to 10 carbon atoms, alkyl having 1 to 4 carbon atoms, or 5 to carbon atoms 10 cycloalkyl, wherein R of >C(-R) ₂ is hydrogen, aryl having 6 to 10 carbon atoms, alkyl having 1 to 4 carbon atoms, or cycloalkyl having 5 to 10 carbon atoms,

At least one hydrogen in the compound represented by formula (2) may be substituted with deuterium, cyano or halogen, and,

The group represented by the general formula (oR) is bonded to at least one of the a ring, b ring, c ring, and the aryl ring and heteroaryl ring formed together with these rings in *,

In the above formula (oR), R ²¹ is an alkyl having 1 to 6 carbon atoms, and R ²² to R ²⁵ are each independently hydrogen, aryl having 6 to 12 carbon atoms, heteroaryl having 2 to 15 carbon atoms, alkyl having 1 to 6 carbon atoms Or a cycloalkyl having 3 to 14 carbon atoms, and ^{adjacent groups among R 22} to R ²⁵ may be bonded to form a naphthalene ring, a phenanthrene ring, a fluorene ring or a carbazole ring together with a benzene ring, and in the formed ring At least one hydrogen of may be substituted with a C6-C12 aryl, a C2-C15 heteroaryl, a C1-C6 alkyl, or a C3-C14 cycloalkyl,

The electron transport material or electron injection material according to item 3.

Item 5.

In the above formula (2),

R ¹ to R ¹¹ are each independently hydrogen, aryl having 6 to 16 carbon atoms (the aryl may be substituted with heteroaryl having 2 to 10 carbon atoms), heteroaryl having 2 to 20 carbon atoms, diarylamino (however, aryl Is aryl having 6 to 10 carbon atoms), diaryl boryl (however, aryl is an aryl having 6 to 10 carbon atoms, and two aryls may be bonded through a single bond or a linking group), alkyl having 1 to 12 carbon atoms, or 3 carbon atoms Is a cycloalkyl of ~16,

Y ¹ is B, P, P=O or P=S,

X ¹ and X ² are each independently >O, >NR, or >C(-R) ₂ , wherein R of >NR is a C6-C10 aryl, a C1-C4 alkyl, or a C5-C10 cyclo Alkyl, and R of >C(-R) ₂ is hydrogen, aryl having 6 to 10 carbon atoms, alkyl having 1 to 4 carbon atoms, or cycloalkyl having 5 to 10 carbon atoms, and,

The group represented by the general formula (oR) is bonded to at least one of the a ring, b ring, and c ring in *,

In the formula (oR), R ²¹ is alkyl having 1 to 4 carbon atoms, and R ²² to R ²⁵ are each independently hydrogen, aryl having 6 to 10 carbon atoms, alkyl having 1 to 4 carbon atoms, or cycloalkyl having 5 to 10 carbon atoms sign,

The electron transport material or electron injection material according to item 3.

Clause 6.

In the above formula (2),

R ¹ to R ¹¹ are each independently hydrogen, aryl having 6 to 16 carbon atoms (the aryl may be substituted with heteroaryl having 2 to 10 carbon atoms), heteroaryl having 2 to 20 carbon atoms, diarylamino (however, aryl Is aryl having 6 to 10 carbon atoms), diaryl boryl (however, aryl is an aryl having 6 to 10 carbon atoms, and two aryls may be bonded through a single bond or a linking group), alkyl having 1 to 12 carbon atoms, or 3 carbon atoms Is a cycloalkyl of ~16,

Y ¹ is B,

X ¹ and X ² are each independently >O or >NR, wherein R of >NR is a C6-C10 aryl, a C1-C4 alkyl, or a C5-C10 cycloalkyl, and,

The group represented by the general formula (oR) is bonded to at least one of the a ring, b ring, and c ring in *,

In the formula (oR), R ²¹ is alkyl having 1 to 4 carbon atoms, and R ²² to R ²⁵ are each independently hydrogen, aryl having 6 to 10 carbon atoms, alkyl having 1 to 4 carbon atoms, or cycloalkyl having 5 to 10 carbon atoms sign,

The electron transport material or electron injection material according to item 3.

Item 7.

In the above formula (2),

R ¹ to R ¹¹ are each independently hydrogen, aryl having 6 to 16 carbon atoms (the aryl may be substituted with heteroaryl having 2 to 10 carbon atoms), heteroaryl having 2 to 20 carbon atoms, diarylamino (however, aryl Is aryl having 6 to 10 carbon atoms), diaryl boryl (however, aryl is an aryl having 6 to 10 carbon atoms, and two aryls may be bonded through a single bond or a linking group), alkyl having 1 to 12 carbon atoms, or 3 carbon atoms Is a cycloalkyl of ~16,

Y ¹ is B or P=O,

X ¹ and X ² are >O, and,

The group represented by the general formula (oR) is bonded to at least one of the a ring, b ring, and c ring in *,

In the formula (oR), R ²¹ is alkyl having 1 to 4 carbon atoms, and R ²² to R ²⁵ are each independently hydrogen, aryl having 6 to 10 carbon atoms, alkyl having 1 to 4 carbon atoms, or cycloalkyl having 5 to 10 carbon atoms sign,

The electron transport material or electron injection material according to item 3.

Item 8.

In the above formula (2),

R ¹ to R ¹¹ are each independently hydrogen, aryl having 6 to 16 carbon atoms (the aryl may be substituted with heteroaryl having 2 to 10 carbon atoms), heteroaryl having 2 to 20 carbon atoms, diarylamino (however, aryl Is aryl having 6 to 10 carbon atoms), diaryl boryl (however, aryl is an aryl having 6 to 10 carbon atoms, and two aryls may be bonded through a single bond or a linking group), alkyl having 1 to 12 carbon atoms, or 3 carbon atoms Is a cycloalkyl of ~16,

Y ¹ is B,

X ¹ and X ² are >O, and,

The group represented by the general formula (oR) is bonded to at least one of the a ring, b ring, and c ring in *,

In the formula (oR), R ²¹ is alkyl having 1 to 4 carbon atoms, and R ²² to R ²⁵ are each independently hydrogen, aryl having 6 to 10 carbon atoms, alkyl having 1 to 4 carbon atoms, or cycloalkyl having 5 to 10 carbon atoms sign,

The electron transport material or electron injection material according to item 3.

Item 9.

In the above formula (2),

Diphenylamino group, carbazolyl group, or benzocarbazolyl group, which may be substituted with alkyl having 1 to 4 carbon atoms or cycloalkyl having 5 to 10 carbon atoms, in at least one of the a ring, b ring and c ring And these groups may be substituted with at least one of the a ring, b ring and c ring through a phenylene group, and

The group represented by the general formula (oR) is bonded in * to at least one of the a ring, b ring and c ring,

The electron transport material or electron injection material according to any one of items 3 to 8.

Item 10.

In the above formula (2),

In the ring a, a diphenylamino group, a carbazolyl group or a benzocarbazolyl group, which may be substituted with a C1-C4 alkyl or a C5-C10 cycloalkyl, is substituted, and these groups are substituted with a phenylene group. May be substituted on the ring, and,

The group represented by the general formula (oR) is bonded in * to the b ring and c ring,

The electron transport material or electron injection material according to any one of items 3 to 8.

Clause 11.

The electron transport material or electron injection material according to any one of items 1 to 10, wherein in the formula (1) or (2), the halogen is fluorine.

Item 12.

The electron transport material or electron injection material according to item 1, wherein the polycyclic aromatic compound is represented by the following structural formula.

("Me" in each formula is methyl.)

Item 13.

A pair of electrodes consisting of an anode and a cathode, a light-emitting layer disposed between the pair of electrodes, and an electron transport material or electron injection material according to any one of items 1 to 12, disposed between the cathode and the light-emitting layer An organic electroluminescent device having an electron transport layer and/or an electron injection layer containing.

Item 14.

At least one of the electron transport layer and the electron injection layer is a borane derivative, a pyridine derivative, a fluoranthene derivative, a BO derivative, an anthracene derivative, a benzofluorene derivative, a phosphine oxide derivative, a pyrimidine derivative, a carbazole derivative, and a tri The organic electroluminescent device according to item 13, comprising at least one selected from the group consisting of an azine derivative, a benzoimidazole derivative, a phenanthroline derivative, and a quinolinol-based metal complex.

Item 15.

The electron transport layer and/or the electron injection layer are alkali metal, alkaline earth metal, rare earth metal, oxide of alkali metal, halide of alkali metal, oxide of alkaline earth metal, halide of alkaline earth metal, oxide of rare earth metal, The organic electroluminescent device according to item 14, further comprising at least one selected from the group consisting of 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.

Clause 16.

A display device or a lighting device comprising the organic electroluminescent element according to any one of items 13 to 15.

According to a preferred embodiment of the present invention, an excellent organic EL device can be provided by using a polycyclic aromatic compound having an alkyl group introduced at a specific position (specifically, an ortho position) as an electron transport material.

Specifically, the inventors of the present invention have a polycyclic aromatic compound (basic skeleton moiety) in which an aromatic ring is connected with a hetero element such as boron, phosphorus, oxygen, nitrogen, sulfur, etc. And have a high triplet excitation energy (E _T ). This means that since the 6-membered ring containing the hetero element has low aromaticity, the reduction of the HOMO-LUMO gap due to the expansion of the conjugated system is suppressed, and the triplet excited state due to electronic perturbation of the hetero element ( It is believed that the localization of SOMO1 and SOMO2 of T1) is the cause. Further, in the polycyclic aromatic compound (basic skeleton moiety) containing the hetero element according to the present invention, the exchange interaction between the two orbitals decreases due to the localization of SOMO1 and SOMO2 in the triplet excited state (T1). Since the energy difference between the anti-excited state (T1) and the singlet excited state (S1) is small, and exhibits a thermally active delayed fluorescence, it is also useful as a fluorescent material for an organic EL device. Further, a material having a high triplet excitation energy (E _T ) is useful also as an electron transport layer or a hole transport layer of a phosphorescent organic EL device or an organic EL device using thermally active delayed fluorescence. In addition, since these polycyclic aromatic compounds (basic skeleton moieties) can arbitrarily move the energy of HOMO and LUMO by introduction of a substituent, it is possible to optimize the ionization potential and electron affinity according to the surrounding material.

In addition to the characteristics of the basic skeleton moiety, the group represented by the general formula (oR) is introduced into the compound of the present invention, thereby substituting an alkyl group at a specific position (specifically, the ortho position), thereby increasing the glass transition temperature of the compound. In this way, the heat resistance of the organic thin film is improved, and in particular, the device life can be improved. In addition, the present invention is not particularly limited to these principles.

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

1. Alkyl-substituted polycyclic aromatic compounds and their multimers

The electron transport material or electron injection material according to the present invention contains a polycyclic aromatic compound represented by the following general formula (1), or a multimer of a polycyclic aromatic compound having a plurality of structures represented by the following general formula (1), and preferably Contains a polycyclic aromatic compound represented by the following general formula (2), or a multimer of a polycyclic aromatic compound having a plurality of structures represented by the following general formula (2), and at least one hydrogen in these compounds or structures is the following general It is substituted with a group represented by formula (oR). In addition, in the formula (1), "B" in the ring together with "A" and "C" is a symbol representing a ring structure represented by a ring, and other symbols are the same as defined above.

Ring A, ring B, and ring C in the general formula (1) are each independently an aryl ring or a heteroaryl ring, and at least one hydrogen in these rings may be substituted with a substituent. This substituent is substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted diarylamino, substituted or unsubstituted diheteroarylamino, substituted or unsubstituted arylheteroarylamino (aryl and heteroaryl amino). Amino group having aryl), substituted or unsubstituted diarylboryl (two aryls may be bonded through a single bond or a linking group), substituted or unsubstituted alkyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted Of alkoxy or substituted or unsubstituted aryloxy is preferable. 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 ring or a 6-membered ring that shares a bond with the central condensed bicyclic structure of General Formula (1) consisting of ^{Y 1} , X ¹ and X ^2.

Here, the "condensed bicyclic structure" means a structure in which two saturated hydrocarbon rings containing ^{Y 1} , X ¹ and X ² are condensed as shown in the center of General Formula (1). In addition, "a 6-membered ring which shares a condensed bicyclic structure and a bond" means, for example, a ring condensed into the condensed bicyclic structure (benzene ring (6-membered ring)) as represented by the general formula (2). it means. In addition, "(A ring being) aryl ring or heteroaryl ring has this 6-membered ring" means that ring A is formed only with this 6-membered ring, or other rings are further condensed to this 6-membered ring so that ring A is Means to be formed. In other words, "the aryl ring (which is a ring A) or a heteroaryl ring which has a 6-membered ring" herein means that the 6-membered ring constituting all or part of the A ring is condensed into the condensed bicyclic structure. The same description applies to "B ring (b ring)", "C ring (c ring)", and also "5-membered ring".

A ring (or B ring, C ring) in general formula (1) is a ring and its substituents R ¹ to R ^{3 in} general formula (2) (or b ring and its substituents R ⁸ to R ¹¹ , c It corresponds to a ring and its substituents R ^{4 to R 7} ). That is, the general formula (2) corresponds to a structure in which "the A to C ring having a six-membered ring" is selected as the A to C ring in the general formula (1). In that sense, each ring of General Formula (2) is represented by lowercase letters a to c.

^{In general formula (2), adjacent groups among the substituents R 1} to R ¹¹ of ring a, ring b and ring c may be bonded to each other to form an aryl ring or heteroaryl ring together with ring a, ring b, or ring c, At least one hydrogen in the formed ring is aryl, heteroaryl, diarylamino, diheteroarylamino, arylheteroarylamino, diarylboryl (two aryls may be bonded through a single bond or a linking group), alkyl , Cycloalkyl, alkoxy, or aryloxy may be substituted, and at least one hydrogen in these may be substituted with aryl, heteroaryl, alkyl or cycloalkyl. Therefore, the polycyclic aromatic compound represented by the general formula (2) is represented by the following formulas (2-1) and (2-2), depending on the mutual bonding form of the substituents in the a ring, b ring and c ring. Likewise, the ring structure constituting the compound changes. The A'ring, B'ring, and C'ring in each formula correspond to the A ring, B ring, and C ring respectively in General formula (1). In addition, ^{definitions of R 1} to R ¹¹ , a, b, c, Y ¹ , X ¹ and X ² in each formula are the same as those in General Formula (2).

The A'ring, B'ring, and C'ring in the above formulas (2-1) and (2-2), when explained by general formula (2), ^{adjacent groups in the substituents R 1} to R ¹¹ are bonded to each other, , Represents an aryl ring or heteroaryl ring formed together with ring a, ring b, and ring c, respectively (it may also be referred to as a condensed ring formed by condensation of another ring structure with ring a, ring b or c). In addition, although not shown in the formula, there are also compounds in which all of the a ring, b ring, and c ring are changed to the A'ring, B'ring, and C'ring. In addition, as can be seen from the above formulas (2-1) and (2-2), for example, R ^{8 of the b ring and R 7} of the c ring, R ^{11 of the b ring and R 1} of the a ring ^{, R 4 of the} c ring, and ^{R 3} and the like of the a ring do not correspond to "adjacent groups", and they are not bound. That is, "adjacent group" means a group adjacent to the same ring.

The compound represented by the above formula (2-1) or formula (2-2) is, for example, a benzene ring, an indole ring, a pyrrole ring, a benzofuran ring or a benzene ring that is a ring a (or ring b or c). It is a compound having an A'ring (or B'ring or C'ring) formed by condensation of a benzothiophene ring, and the condensed ring A'(or condensed ring B'or condensed ring C') formed by being formed is a naphthalene ring, It is a carbazole ring, an indole ring, a dibenzofuran ring, or a dibenzothiophene ring.

^{Y 1} in the general formula (1) is B, P, P=O, P=S, Al, Ga, As, Si-R or Ge-R, wherein R of Si-R and Ge-R is aryl , Alkyl or cycloalkyl. In the case of P=O, P=S, Si-R or Ge-R, the atom bonded to the A ring, B ring or C ring is P, Si or Ge. Y ¹ is preferably B, P, P=O, P=S, or Si-R, more preferably B or P=O, and particularly preferably B. This explanation is also the same for ^{Y 1} in General Formula (2).

^{X 1} and X ² in General Formula (1) are each independently >O, >NR, >C(-R) ₂ , >S or >Se, and R of >NR may be substituted. Aryl, optionally substituted heteroaryl, optionally substituted alkyl, or optionally substituted cycloalkyl, wherein _{R of >C(-R) 2} is hydrogen, optionally substituted aryl, alkyl or cycloalkyl, said R of >NR and/or R of >C(-R) ₂ may be bonded to at least one of the A ring, B ring and C ring by a linking group or a single bond, and as a linking group -O-, -S -Or -C(-R) ₂ -is preferred. In addition, R in said "-C(-R) ₂ -" is hydrogen, alkyl, or cycloalkyl. As X ¹ and X ² , each independently >O, >NR, or >C(-R) ₂ is preferred, >O or >NR is more preferred, and >O is particularly preferred. This description is also the same for ^{X 1} and X ² in General Formula (2).

Herein, "R of the >NR and/or R of the >C(-R) _{2 in} the general formula (1) is at least one of the ring A, ring B, and ring C by a linking group or a single bond. In the general formula (2), "R in the above >NR and/or R in the >C(-R) ₂ is -O-, -S-, -C(-R) ₂ -Or it is bonded to at least one of the a-ring, b-ring, and c-ring by a single bond."

^{This regulation can be expressed by a compound having a ring structure in which X 1} or X ² is introduced into the condensed ring B'and the condensed ring C', represented by the following formula (2-3-1). That is, for example, the B'ring (or C'formed by condensation of other rings by introducing ^{X 1} (or X ² ) to the benzene ring that is the b ring (or c ring) in the general formula (2)) Ring). The formed condensed ring B'(or condensed ring C') is, for example, a phenoxazine ring, a phenothiazine ring, or an acridine ring.

In addition, the above regulation can also be expressed as a compound having a ring structure in which ^{X 1} and/or X ² is introduced into the condensed ring A′, represented by the following formula (2-3-2) or formula (2-3-3). have. That is, for example, it is a compound having an A'ring formed by condensation of other rings by introducing ^{X 1} (and/or X ² ) to a benzene ring which is a ring in the general formula (2). The formed condensed ring A'is, for example, a phenoxazine ring, a phenothiazine ring, or an acridine ring.

The definitions of R ¹ to R ¹¹ , a, b, c, Y ¹ , X ¹ and X ^{2 in each} of the above formulas are the same as those in General Formula (2).

Examples of the "aryl ring" which is the A ring, the B ring and the C ring in the general formula (1) include, for example, an aryl ring having 6 to 30 carbon atoms, preferably an aryl ring having 6 to 16 carbon atoms, and An aryl ring of is more preferable, and an aryl ring having 6 to 10 carbon atoms is particularly preferable. In addition, this "aryl ring" corresponds to "an aryl ring formed with a ring a, a ring b, or a ring c by bonding of adjacent groups among ^{R 1} to R ¹¹ " as defined in General Formula (2), and Since the a ring (or b ring, c ring) is already composed of a benzene ring having 6 carbon atoms, the total number of carbon atoms of the condensed ring condensed with the 5-membered ring becomes the lower limit carbon number.

Specific examples of the "aryl ring" include a monocyclic benzene ring, a bicyclic biphenyl ring, a condensed bicyclic naphthalene ring, a tricyclic terphenyl ring (m-terphenyl, o-terphenyl, p-terphenyl), and condensation 3 Cylindrical phosphorus, acenaphthylene ring, fluorene ring, phenalene ring, phenanthrene ring, condensed tetracyclic triphenylene ring, pyrene ring, naphthacene ring, condensed pentacyclic perylene ring, and pentacene ring.

Examples of the "heteroaryl ring" which is the A ring, the B ring and the C ring in the general formula (1) include, for example, a heteroaryl ring having 2 to 30 carbon atoms, and a heteroaryl ring having 2 to 25 carbon atoms is preferable. A heteroaryl ring of to 20 is more preferable, a heteroaryl ring of 2 to 15 carbon atoms is more preferable, and a heteroaryl ring of 2 to 10 carbon atoms is particularly preferable. In addition, examples of the "heteroaryl ring" include heterocycles containing 1 to 5 heteroatoms selected from oxygen, sulfur and nitrogen in addition to carbon as ring constituent atoms. In addition, this "heteroaryl ring" corresponds to "a heteroaryl ring formed together with a ring a, a ring b, or a ring c by bonding of adjacent groups among ^{R 1} to R ¹¹ " as defined in General Formula (2), Further, since the a ring (or b ring, c ring) is already composed of a benzene ring having 6 carbon atoms, the total number of carbon atoms of the condensed ring condensed with the 5-membered ring is 6 carbon atoms at the lower limit.

As a specific "heteroaryl ring", for example, 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, pyrimidine ring, pyridazine ring, pyrazine ring, triazine ring, indole ring, isoindole ring, 1H-indazole ring, benzoimidazole ring, benzoxazole ring, benzothiazole ring, 1H-benzotriazole ring, quinoline ring, Isoquinoline ring, cinnoline ring, quinazoline ring, quinoxaline ring, phthalazine ring, naphthyridine ring, purine ring, pteridine ring, carbazole ring, acridine ring, phenoxatiin ring, phenoxazine ring, phenothia Jin ring, phenazine ring, phenazacillin ring, indolizine ring, furan ring, benzofuran ring, isobenzofuran ring, dibenzofuran ring, thiophene ring, benzothiophene ring, dibenzothiophene ring, furazane ring, tian Trenfan, etc. are mentioned.

At least one hydrogen in the "aryl ring" or "heteroaryl ring" is a first substituent, a substituted or unsubstituted "aryl", a substituted or unsubstituted "heteroaryl", or a substituted or unsubstituted "aryl" Diarylamino", substituted or unsubstituted "diheteroarylamino", substituted or unsubstituted "arylheteroarylamino", substituted or unsubstituted "diarylboryl (two aryls are bonded through a single bond or a linking group) May be)”, substituted or unsubstituted “alkyl”, substituted or unsubstituted “cycloalkyl”, substituted or unsubstituted “alkoxy”, or substituted or unsubstituted “aryloxy”. , "Aryl" or "heteroaryl" as the first substituent, aryl of "diarylamino", heteroaryl of "diheteroarylamino", aryl and heteroaryl of "arylheteroarylamino", and "diarylboryl" Examples of the aryl of "aryloxy" include monovalent groups such as the above-described "aryl ring" or "heteroaryl ring".

Moreover, as "alkyl" as a 1st substituent, either a linear chain or a branched chain may be sufficient, For example, a C1-C24 linear-chain alkyl or a C3-C24 branched alkyl is mentioned. Alkyl having 1 to 18 carbon atoms (branched alkyl having 3 to 18 carbon atoms) is preferred, alkyl having 1 to 12 carbon atoms (branched chain alkyl having 3 to 12 carbon atoms) is more preferred, and alkyl having 1 to 6 carbon atoms (3 carbon atoms Branched chain alkyl of -6) is more preferable, and alkyl having 1 to 4 carbon atoms (branched alkyl having 3 to 4 carbon atoms) is particularly preferable. As C1-C4 alkyl, a methyl group and a t-butyl group are more preferable, but a t-butyl group is still more preferable.

Specific examples of alkyl include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, s-butyl, t-butyl, n-pentyl, isopentyl, neopentyl, t-pentyl, n-hexyl, 1- Methylpentyl, 4-methyl-2-pentyl, 3,3-dimethylbutyl, 2-ethylbutyl, n-heptyl, 1-methylhexyl, n-octyl, t-octyl, 1-methylheptyl, 2-ethylhexyl, 2-propylpentyl, n-nonyl, 2,2-dimethylheptyl, 2,6-dimethyl-4-heptyl, 3,5,5-trimethylhexyl, n-decyl, n-undecyl, 1-methyldecyl, n -Dodecyl, n-tridecyl, 1-hexylheptyl, n-tetradecyl, n-pentadecyl, n-hexadecyl, n-heptadecyl, n-octadecyl, n-eicosyl, and the like.

In addition, as "cycloalkyl" as a 1st substituent, a C3-C24 cycloalkyl, a C3-C20 cycloalkyl, a C3-C16 cycloalkyl, a C3-C14 cycloalkyl, a C5-C10 cyclo Alkyl, a C5-C8 cycloalkyl, a C5-C6 cycloalkyl, a C5 cycloalkyl, etc. are mentioned.

Specific examples of cycloalkyl include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl, and their alkyl (especially methyl) substituents having 1 to 4 carbon atoms, norbornenyl, bi Cyclo[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, decahydroazulenyl, and the like.

Moreover, as "alkoxy" as a 1st substituent, a C1-C24 linear or C3-C24 branched alkoxy is mentioned, for example. C1-C18 alkoxy (C3-C18 branched chain alkoxy) is preferable, C1-C12 alkoxy (C3-C12 branched chain alkoxy) is more preferable, and C1-C6 alkoxy ( Branched chain alkoxy having 3 to 6 carbon atoms) is more preferable, and alkoxy having 1 to 4 carbon atoms (branched alkoxy having 3 to 4 carbon atoms) is particularly preferable.

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

In addition, the description of aryl described above can be cited as "aryl" in "diarylboryl" as the first substituent. In addition, these two aryls may be bonded via a single bond or a linking group (for example, >C(-R) ₂ , >O, >S, or >NR). Here, R of >C(-R) ₂ and >NR is aryl, heteroaryl, diarylamino, alkyl, cycloalkyl, alkoxy or aryloxy (above, the first substituent), and the first substituent includes aryl, Heteroaryl, alkyl or cycloalkyl (above, the second substituent) may be further substituted, and specific examples of these groups include aryl, heteroaryl, diarylamino, alkyl, cycloalkyl, alkoxy or aryloxy as the first substituent described above. You can cite the explanation of

Specifically, the light emission wavelength can be adjusted by steric hindrance, electron donation and electron attraction of the structure of the first substituent, preferably a group represented by any of the following structural formulas (S-1) to (S-94) And more preferably, formula (S-1), formula (S-2), formula (S-5), formula (S-9) to formula (S-19), and formula (S-24) to formula (S-50) and a group represented by any one of formulas (S-51) to (S-94), more preferably formula (S-1), formula (S-2), formula (S-5 ), Formula (S-9), Formula (S-10), Formula (S-15), Formula (S-16), Formula (S-24), Formula (S-30), Formula (S-46) , Formula (S-48), Formula (S-50), Formula (S-51), Formula (S-56) to Formula (S-58), Formula (S-70), Formula (S-71), Any of formula (S-73), formula (S-74), formula (S-76), formula (S-79), formula (S-80), formula (S-83), and formula (S-84) It is a flag that appears as one.

In the following structural formula, "Me" represents methyl, and "tBu" represents t-butyl.

The first substituent, substituted or unsubstituted "aryl", substituted or unsubstituted "heteroaryl", substituted or unsubstituted "diarylamino", substituted or unsubstituted "diheteroarylamino", substituted or unsubstituted Substituted “arylheteroarylamino”, substituted or unsubstituted “diarylboryl (two aryls may be bonded through a single bond or a linking group)”, substituted or unsubstituted “alkyl”, substituted or unsubstituted As described as “cycloalkyl”, substituted or unsubstituted “alkoxy”, or substituted or unsubstituted “aryloxy”, at least one hydrogen in these is a second substituent. It may be substituted. Examples of the second substituent include aryl, heteroaryl, alkyl, or cycloalkyl, and specific groups of these groups are monovalent groups of the above-described "aryl ring" or "heteroaryl ring", as well as the first substituent. The description of "alkyl" or "cycloalkyl" can be referred to. In addition, in aryl or heteroaryl as the first and second substituents, at least one hydrogen in these groups is an aryl such as phenyl (specific examples are the groups described above), alkyls such as methyl (specific examples are the groups described above). Alternatively, groups substituted with cycloalkyl such as cyclohexyl (specific examples are the groups described above) are included in aryl or heteroaryl as the first and second substituents. As an example, when the first and second substituents are carbazolyl groups, at least one hydrogen at position 9 is substituted with aryl such as phenyl, alkyl such as methyl, or cycloalkyl such as cyclohexyl. A zolyl group is also included in heteroaryl as the first and second substituents. In addition, when the first and second substituents are benzoimidazole groups, at least one hydrogen in this group is a benzoimidazole group substituted with an aryl such as phenyl, an alkyl such as methyl, or a cycloalkyl such as cyclohexyl It is also included in heteroaryl as the first and second substituents.

^{Aryl of R 1} to R ¹¹ of the general formula (2), heteroaryl, aryl of diarylamino, heteroaryl of diheteroarylamino, aryl and heteroaryl of arylheteroarylamino, aryl of diarylboryl, or As the aryl of aryloxy, a monovalent group of the "aryl ring" or "heteroaryl ring" described in the general formula (1) can be mentioned. In addition, as ^{the alkyl, cycloalkyl or alkoxy for R 1} to R ¹¹ , refer to the description of “alkyl”, “cycloalkyl” or “alkoxy” as the first substituent in the description of the above general formula (1). can do. In addition, aryl, heteroaryl, alkyl, or cycloalkyl as a substituent for these groups is also the same. In addition, ^{when adjacent groups of R 1} to R ¹¹ are bonded to form an aryl ring or heteroaryl ring together with a ring, b ring, or c ring, heteroaryl, diarylamino, di. The same is true for heteroarylamino, arylheteroarylamino, diarylboryl, alkyl, cycloalkyl, alkoxy or aryloxy and better substituents aryl, heteroaryl, alkyl or cycloalkyl.

^{R of Si-R and Ge-R in Y 1} of the general formula (1) is aryl, alkyl or cycloalkyl, and examples of this aryl, alkyl or cycloalkyl include the groups described above. In particular, aryl having 6 to 10 carbon atoms (e.g., phenyl, naphthyl, etc.), alkyl having 1 to 4 carbon atoms (e.g., methyl, ethyl, t-butyl, etc., especially t-butyl) or 5 to 10 carbon atoms Cycloalkyl (preferably cyclohexyl or adamantyl) is preferred. This explanation is also the same for ^{Y 1} in General Formula (2).

^{R of >NR in X 1} and X ² of the general formula (1) is aryl, heteroaryl, alkyl or cycloalkyl which may be substituted with the second substituent described above, and at least one of aryl or heteroaryl Hydrogen may be substituted with, for example, alkyl or cycloalkyl. Examples of the aryl, heteroaryl, alkyl and cycloalkyl include the groups described above. In particular, C6-C10 aryl (e.g., phenyl, naphthyl, etc.), C2-C15 heteroaryl (e.g., carbazolyl, etc.), C1-C4 alkyl (e.g., methyl , Ethyl, t-butyl, etc., particularly t-butyl) or a cycloalkyl having 5 to 10 carbon atoms (preferably cyclohexyl or adamantyl) is preferred. This description is also the same for ^{X 1} and X ² in General Formula (2).

R of >C(-R) ₂ ^{in X 1} and X ² in the general formula (1) is hydrogen, aryl, alkyl or cycloalkyl which may be substituted with the second substituent described above, and at least in aryl One hydrogen may be substituted with, for example, alkyl or cycloalkyl. Examples of this aryl, alkyl or cycloalkyl include the groups described above. In particular, aryl having 6 to 10 carbon atoms (eg, phenyl, naphthyl, etc.), alkyl having 1 to 4 carbon atoms (eg, methyl, ethyl, t-butyl, etc., particularly t-butyl) or 5 to 10 carbon atoms Cycloalkyl (preferably cyclohexyl or adamantyl) of is preferred. This description is also the same for ^{X 1} and X ² in General Formula (2).

_{R of "-C(-R) 2} -" which is a linking group in the general formula (1) 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 (eg, methyl, ethyl, t-butyl, etc., particularly t-butyl) or cycloalkyl having 5 to 10 carbon atoms (preferably cyclohexyl or adamantyl) is preferable. This explanation is also the same in _{"-C(-R) 2} -" which is a linking group in General Formula (2).

Further, the present invention is a multimer of a polycyclic aromatic compound having a plurality of unit structures represented by the general formula (1), and preferably a multimer of a polycyclic aromatic compound having a plurality of unit structures represented by the general formula (2). As for the multimer, a 2-6-mer is preferable, a 2-trimer is more preferable, and a dimer is especially preferable. The multimer may be a form having a plurality of the unit structures in one compound, for example, a form in which the unit structure is multiple bonded with a linking group such as a single bond, an alkylene group having 1 to 3 carbon atoms, a phenylene group, or a naphthylene group. In addition to (linked multimer), any ring (ring A, ring B or C, ring a, ring b, or ring c) contained in the unit structure is bonded to share in a plurality of unit structures (ring A covalent multimer) may be used, and any ring (ring A, ring B or C, ring a, ring b, or ring c) contained in the unit structure may be condensed and bonded to each other (ring condensation type multimer Sieve) may be used, but a ring covalent multimer and a ring condensed multimer are preferable, and a ring covalent multimer is more preferable.

As such a multimer, for example, the following formula (2-4), formula (2-4-1), formula (2-4-2), formula (2-5-1) to formula (2-5-4 ) Or a multimeric compound represented by formula (2-6). The multimeric compound represented by the following formula (2-4), when explained by the general formula (2), has a large amount of unit structures represented by a plurality of general formulas (2) in one compound by sharing a benzene ring as a ring a It is a sieve compound (cyclic covalent multimer). In addition, the multimeric compound represented by the following formula (2-4-1), when explained by the general formula (2), is made to share a benzene ring which is a ring, so that one unit structure represented by two general formulas (2) is It is a multimer compound (cyclic covalent multimer) contained in a compound. In addition, the multimeric compound represented by the following formula (2-4-2), when explained by the general formula (2), is made to share a benzene ring, which is a ring, so that one unit structure represented by the three general formulas (2) is It is a multimer compound (cyclic covalent multimer) contained in a compound. In addition, the multimeric compound represented by the following formula (2-5-1) to formula (2-5-4), when explained by the general formula (2), is made to share a benzene ring that is a b ring (or c ring) , A multimer compound (cyclic covalent multimer) having a unit structure represented by a plurality of general formulas (2) in one compound. In addition, the multimeric compound represented by the following formula (2-6) is explained by the general formula (2), for example, a benzene ring which is a b ring (or a ring, c ring) of a certain unit structure and a certain unit structure It is a multimer compound (ring condensation type multimer) which has a unit structure represented by a plurality of general formulas (2) in one compound by condensing the benzene ring as ring b (or ring a, ring c).

The multimeric compound is a multimerization form represented by formula (2-4), formula (2-4-1) or formula (2-4-2), and formula (2-5-1) to formula (2- Any one of 5-4) or a multimer in which a multimerization form represented by Formula (2-6) may be combined, and represented by any of Formulas (2-5-1) to (2-5-4) It may be a multimer in which a multimerization form and a multimerization form expressed by formula (2-6) are combined, and can be expressed by formula (2-4), formula (2-4-1) or formula (2-4-2). Even if it is a multimer in which the multimerization form expressed and the multimerization form expressed by any one of formulas (2-5-1) to (2-5-4) and the multimerization form expressed by formula (2-6) are combined do.

In addition, the hydrogen in the chemical structure of the polycyclic aromatic compound represented by the general formula (1) or (2) and the multimer thereof may be deuterium, cyano, or halogen in whole or in part. For example, in formula (1), A ring, B ring, C ring (A to C ring is an aryl ring or heteroaryl ring), a substituent to A to C ring, Y ¹ is Si-R or Ge-R When R (=alkyl, cycloalkyl, aryl), X ¹ and X ² are >NR or >C(-R) ₂ When R (=alkyl, cycloalkyl, aryl), and the general formula ( The hydrogen in the group of oR) may be substituted with deuterium, cyano, or halogen, and among these, all or part of the hydrogen in the aryl or heteroaryl is substituted with deuterium, cyano, or halogen. Halogen is fluorine, chlorine, bromine or iodine, preferably fluorine, chlorine or bromine, and more preferably fluorine or chlorine.

In addition, at least one hydrogen in the chemical structure of the polycyclic aromatic compound represented by general formula (1) or (2) and its multimer is substituted with a group represented by the following general formula (oR), and all hydrogens or some hydrogens are represented by the following formula The contribution represented by (oR) is also possible.

In the formula (oR), R ²¹ is alkyl, R ²² to R ²⁵ are each independently hydrogen, aryl, heteroaryl, alkyl or cycloalkyl, and ^{adjacent groups in R 22} to R ²⁵ are bonded to each other to form a benzene ring and Together, an aryl ring or heteroaryl ring may be formed, at least one hydrogen in the formed ring may be substituted with aryl, heteroaryl, alkyl or cycloalkyl, and the group represented by the formula (oR) is * It is substituted with at least one hydrogen in the compound or structure represented by the above formula (1).

As ^{the "alkyl" of R 21} , either linear or branched chain may be used, and examples thereof include straight chain alkyl having 1 to 24 carbon atoms or branched chain alkyl having 3 to 24 carbon atoms. Alkyl having 1 to 18 carbon atoms (branched alkyl having 3 to 18 carbon atoms) is preferred, alkyl having 1 to 12 carbon atoms (branched chain alkyl having 3 to 12 carbon atoms) is more preferred, and alkyl having 1 to 6 carbon atoms (3 carbon atoms Branched chain alkyl of -6) is more preferable, and alkyl having 1 to 4 carbon atoms (branched alkyl having 3 to 4 carbon atoms) is particularly preferable. As C1-C4 alkyl, although a methyl group and t-butyl group are more preferable, a methyl group is still more preferable.

Specific examples of alkyl include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, s-butyl, t-butyl, n-pentyl, isopentyl, neopentyl, t-pentyl, n-hexyl, 1- Methylpentyl, 4-methyl-2-pentyl, 3,3-dimethylbutyl, 2-ethylbutyl, n-heptyl, 1-methylhexyl, n-octyl, t-octyl, 1-methylheptyl, 2-ethylhexyl, 2-propylpentyl, n-nonyl, 2,2-dimethylheptyl, 2,6-dimethyl-4-heptyl, 3,5,5-trimethylhexyl, n-decyl, n-undecyl, 1-methyldecyl, n -Dodecyl, n-tridecyl, 1-hexylheptyl, n-tetradecyl, n-pentadecyl, n-hexadecyl, n-heptadecyl, n-octadecyl, n-eicosyl, and the like.

As the "aryl", "heteroaryl", "alkyl" or "cycloalkyl" for ^{R 22} to R ^{25, the description as the first substituent described above can be cited.}

In addition, ^{adjacent groups among R 22} to R ²⁵ may be bonded to each other to form an aryl ring or heteroaryl ring together with a benzene ring, and at least one hydrogen in the formed ring is aryl, heteroaryl, alkyl or cycloalkyl. May be substituted with, but for these explanations, in the general formula (2), ^{adjacent groups among R 1} to R ¹¹ are bonded to form an aryl ring or heteroaryl ring together with the a ring, b ring or c ring. The explanation of the case can be cited. Specific examples of the aryl ring or heteroaryl ring formed together with the benzene ring include a naphthalene ring, a phenanthrene ring, a fluorene ring or a carbazole ring.

The group represented by the formula (oR) may be substituted with at least one hydrogen in the compound or structure represented by the formula (1), but preferably, among the A ring, B ring and C ring of the general formula (1) At least one (speaking by the general formula (2), aryl ring and heteroaryl ring formed together with a ring, b ring or c ring by bonding of adjacent groups among ^{a ring, b ring, c ring and R 1} to R ¹¹ At least one of them). More preferably, the B ring and/or the C ring of the general formula (1) (speaking with the general formula (2), the b ring and/or the c ring, or the ^{adjacent groups of R 4} to R ¹¹ are bonded to each other to b It is directly bonded to the aryl ring and/or heteroaryl ring) formed together with the ring or c ring. More preferably, both the B ring and the C ring of the general formula (1) (speaking with the general formula (2), both the b ring and the c ring, or ^{adjacent groups of R 8} to R ¹¹ are bonded to each other together with the b ring. The formed aryl ring or heteroaryl ring and ^{adjacent groups among R 4} to R ⁷ are bonded to each other, and are directly bonded to the aryl ring or heteroaryl ring formed together with the c ring).

In addition, the polycyclic aromatic compound and its multimer represented by the general formula (1) or (2) are preferably substituted with a diarylamino group (especially diphenylamino group), carbazolyl group or benzocarbazolyl group, and these The groups may be substituted with C1-C4 alkyl or C5-C10 cycloalkyl, and these groups may be substituted with the polycyclic aromatic compound and its multimer via a phenylene group.

These groups are preferably at least one of ring A, ring B, and ring C of general formula (1) (speaking of general formula (2), ring a, ring b, ring c, and adjacent ^{one of} R 1 to R ¹¹⁾ The groups are bonded to each other and bonded to at least one of the aryl ring and heteroaryl ring formed together with the a ring, b ring, or c ring) directly or via a phenylene group. More preferably, in the A ring of the general formula (1) (speaking with the general formula (2), an aryl ring or a heteroaryl ring formed together with the a ring by bonding adjacent groups of ^{a ring or R 1} to R ³⁾ It is bonded directly or through a phenylene group.

As a more specific example of the alkyl-substituted polycyclic aromatic compound of the present invention, a compound represented by the following structural formula may be mentioned. In the following structural formula, "Me" represents a methyl group, "Et" represents an ethyl group, "iPr" represents an isopropyl group, "Hep" represents a heptyl group, "tBu" represents a t-butyl group, and "CN" represents a cyano group.

2. Alkyl-substituted polycyclic aromatic compound and method for preparing its multimer

The polycyclic aromatic compound represented by general formula (1) or (2) and its multimer can be synthesized, for example, by applying the method disclosed in International Publication No. 2015/102118. Basically, first, an intermediate is prepared by combining A ring (a ring), B ring (b ring), and C ring (c ring) with a linking group ( ^{a group containing X 1} or X ^{2) (first reaction)} Then, the final product can be prepared by bonding the A ring (a ring), B ring (b ring), and C ring (c ring) with a linking group ( ^{a group containing Y 1) (second reaction).} In addition, by using a raw material substituted with a group represented by the formula (oR) somewhere in these reaction steps, or by adding a step of introducing a group represented by the formula (oR), the compound of the present invention in which the desired position is alkyl substituted can be prepared. have.

In the first reaction, for example, if it is an etherification reaction, a general reaction such as nucleophilic substitution reaction or Ullmann reaction can be used, and if it is an amination reaction, a general reaction such as Buchwald-Hartwig reaction is used. I can. Further, in the second reaction, a tandem hetero-Friedel-Crafts reaction (continuous aromatic electron substitution reaction, hereinafter the same) can be used.

The second reaction is a reaction of introducing ^{Y 1} which couples the A ring (a ring), B ring (b ring) and C ring (c ring) as shown in the following schemes (1) or (2), For example, the case where Y ¹ is a boron atom and X ¹ and X ² are oxygen atoms is shown below. First, ^{the hydrogen atom between X 1} and X ² is orthometalized with n-butyllithium, sec-butyllithium or t-butyllithium. Then, boron trichloride, boron tribromide, etc. are added, metal exchange of lithium-boron is carried out, and then a Bronsted base such as N,N-diisopropylethylamine is added, thereby causing a tandem Bora Friedel Crafts reaction. , You can get the object. In the second reaction, a Lewis acid such as aluminum trichloride may be added to accelerate the reaction. In addition, in the following schemes (1) and (2), and in subsequent schemes (3) to (5), the definition of the sign in each structural formula is the same as the definition described above.

In addition, the above schemes (1) and (2) mainly show a method for producing a polycyclic aromatic compound represented by general formulas (1) or (2), and for the multimer, a plurality of A rings (a rings), It can be produced by using an intermediate having a B ring (b ring) and a C ring (c ring). In detail, it demonstrates in the following schemes (3)-(5). In this case, the target product can be obtained by making the amount of a reagent such as butyl lithium to be used in a double or triple amount.

In the above scheme, lithium was introduced at a desired position by orthometalization. However, a halogen such as a bromine atom may be introduced at a position at which lithium is to be introduced, and lithium may also be introduced at a desired position by halogen-metal exchange.

In addition, a group represented by the general formula (oR) is bonded to a ring a, a ring b, and/or a ring c (especially a ring) in the general formula (2), and further, a ring a, a ring b and/or a ring c Particularly in ring b and/or ring c), diphenylamino group, carbazolyl group, or benzocarbazolyl group (these groups are the above-mentioned a ring, b ring through phenylene group) which may be substituted with alkyl having 1 to 4 carbon atoms. And/or a polycyclic aromatic compound substituted by c ring) can also be produced in the same manner according to the above scheme.

For example, for the polycyclic aromatic compound (M-5) having a group represented by the general formula (oR) and a diphenylamino group, as shown in the following scheme (6), the intermediate (M-2) substituted with a diphenylamino group and , After synthesizing an intermediate (M-3) substituted with a group represented by the formula (oR), and synthesizing an intermediate (M-4) combining them, and then cyclizing the polycyclic aromatic compound (M-5) It can be synthesized. In the scheme (6), Hal represents halogen, X represents halogen or hydrogen, and the definition of other signs is the same as the definition of signs in General Formula (2).

The intermediate before cyclization in the scheme (6) can also be synthesized by the method shown in scheme (1) or the like. That is, an intermediate having a desired substituent can be synthesized by appropriately combining the Buchwald-Hartwig reaction, the Suzuki coupling reaction, the nucleophilic substitution reaction, the etherification reaction by the Ullmann reaction, or the like. In these reactions, a commercially available product can also be used as a raw material to become a precursor.

3. Organic EL device

Hereinafter, the organic EL device according to the present embodiment will be described in detail based on the drawings. 1 is a schematic cross-sectional view showing an organic EL device according to the present embodiment.

<Structure of organic electroluminescent device>

The organic EL device 100 shown in FIG. 1 includes a substrate 101, an anode 102 provided on the substrate 101, a hole injection layer 103 provided on the anode 102, and a hole injection layer ( 103), the hole transport layer 104 provided on the hole transport layer 104, the light emitting layer 105 provided on the hole transport layer 104, the electron transport layer 106 provided on the light emitting layer 105, and the electron injection provided on the electron transport layer 106 It has a layer 107 and a cathode 108 provided on the electron injection layer 107.

In addition, the organic EL element 100 reverses the order of fabrication, for example, the substrate 101, the cathode 108 provided on the substrate 101, and the electron injection layer provided on the cathode 108 ( 107), the electron transport layer 106 provided on the electron injection layer 107, the light emitting layer 105 provided on the electron transport layer 106, the hole transport layer 104 provided on the light emitting layer 105, and a hole transport layer A configuration including a hole injection layer 103 provided on 104 and an anode 102 provided on the hole injection layer 103 may be employed.

Not all of the above layers are indispensable, and the minimum structural units are composed of an anode 102, a light emitting layer 105, and a cathode 108, and a hole injection layer 103, a hole transport layer 104, and an electron transport layer ( 106), the electron injection layer 107 is an arbitrary layer. In addition, each of the layers may be composed of a single layer or may be composed of a plurality of layers.

As the form of the layer constituting the organic EL element, in addition to the configuration form of the above-described "substrate/anode/hole injection layer/hole transport layer/light-emitting layer/electron transport layer/electron injection layer/cathode", “substrate/anode/hole transport layer/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 layer/electron injection layer/ Cathode", "Substrate/anode/hole injection layer/hole transport layer/light emitting layer/electron transport layer/cathode", "substrate/anode/light emitting layer/electron transport layer/electron injection layer/cathode", "substrate/anode/hole transport layer/light emitting layer/ Electron injection layer/cathode”, “substrate/anode/hole transport layer/light-emitting layer/electron transport layer/cathode”, “substrate/anode/hole injection layer/light-emitting layer/electron injection layer/cathode”, “substrate/anode/hole injection layer/ The configuration of a light emitting layer/electron transport layer/cathode", "substrate/anode/light emitting layer/electron transport layer/cathode", and "substrate/anode/light emitting layer/electron injection layer/cathode" may be used.

<Substrate in organic electroluminescent device>

The substrate 101 is a support for the organic EL element 100, and usually quartz, glass, metal, plastic, or the like is used. The substrate 101 is formed in a plate shape, a film shape, or a sheet shape depending on the purpose, and, for example, a glass plate, a metal plate, a metal foil, a plastic film, a plastic sheet, or the like is used. Among them, a glass plate and a plate made of transparent synthetic resin such as polyester, polymethacrylate, polycarbonate, and polysulfone are preferable. If it is a glass substrate, soda-lime glass, alkali-free glass, etc. are used, and the thickness needs only to have sufficient thickness to maintain the mechanical strength, so it may be, for example, 0.2 mm or more. The upper limit of the thickness is, for example, 2 mm or less, and preferably 1 mm or less. As for the material of the glass, an alkali-free glass is preferable because it is better to have less ions eluted from the glass, but _{soda lime glass having a barrier coating such as SiO 2 is} also commercially available, and thus can be used. In addition, in order to increase the gas barrier property, the substrate 101 may be provided with a gas barrier film such as a dense silicon oxide film on at least one surface. In particular, a plate, film or sheet made of a synthetic resin having low gas barrier property may be used as the substrate 101. In the case of use, it is preferable to provide a gas barrier film.

<Anode in organic electroluminescent device>

The anode 102 serves to inject holes into the light emitting layer 105. In addition, when the hole injection layer 103 and/or the hole transport layer 104 is provided between the anode 102 and the light emitting layer 105, holes are injected into the light emitting layer 105 through these.

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

The resistance of the transparent electrode is not limited since it is sufficient to supply a sufficient current for light emission of the light-emitting element, but it is preferably low resistance from the viewpoint of power consumption of the light-emitting element. For example, if an ITO substrate of 300 Ω/□ or less, it functions as an element electrode, but at present, it is possible to supply a substrate of about 10 Ω/□, for example, 100 to 5 Ω/□, preferably 50 It is particularly preferable to use a low resistance product of ~5Ω/□. The thickness of ITO can be arbitrarily selected according to the resistance value, but it is usually used between 50 and 300 nm.

<Hole injection layer and hole transport layer in organic electroluminescent device>

The hole injection layer 103 serves to efficiently inject holes moving from the anode 102 into the light emitting layer 105 or the hole transport layer 104. The hole transport layer 104 serves to efficiently transport the holes injected from the anode 102 or the holes injected from the anode 102 through the hole injection layer 103 to the light emitting layer 105. The hole injection layer 103 and the hole transport layer 104 are formed by laminating and mixing one or two or more types of hole injection/transport materials, respectively, or a mixture of a hole injection/transport material and a polymer binder. Further, an inorganic salt such as iron (III) chloride may be added to the hole injection/transport material to form a layer.

As the hole injection/transport material, it is necessary to efficiently inject and transport holes from the positive electrode between electrodes to which an electric field is applied, and it is preferable that the hole injection efficiency is high and the injected holes are efficiently transported. For this, it is preferable that the ionization potential is small, the hole mobility is large, the stability is excellent, and the impurities used as traps are difficult to occur during manufacture and use.

As the material for forming the hole injection layer 103 and the hole transport layer 104, a compound conventionally used as a charge transport material for holes in a photoconductive material, a p-type semiconductor, a hole injection layer and a hole in an organic EL device Arbitrary compounds can be selected and used from known compounds used in the transport layer. These specific examples are carbazole derivatives (N-phenylcarbazole, polyvinylcarbazole, etc.), biscarbazole derivatives such as bis(N-arylcarbazole) or bis(N-alkylcarbazole), triarylamine derivatives (Polymer having 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- carbazole-3-yl) [1,1'-biphenyl] - ^{4,4'-diamine, N 4, N 4, N} 4 ', N 4' - tetrahydro [1,1'-biphenyl] -4-yl) - [1,1'-biphenyl] -4,4 Triphenylamine derivatives such as'-diamine, 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 or thiophene derivatives, oxadiazole derivatives, quinoxaline derivatives (e.g., 1,4,5,8,9,12-hexaazatriphenylene -2,3,6,7,10,11-hexacarbonitrile, etc.), heterocyclic compounds such as porphyrin derivatives, polysilanes, etc. In the polymer system, polycarbonate or styrene derivatives having the above monomers in the side chain, polyvinylcar Bazole, polysilane, and the like are preferable, but it is not particularly limited as long as it is a compound capable of forming a thin film required for manufacturing a light emitting device, injecting holes from the anode, and transporting holes.

It is also known that the conductivity of an organic semiconductor is strongly influenced by its doping. Such an organic semiconductor matrix material is composed of a compound having good electron donation or a compound having good electron acceptability. For the doping of electron donating substances, strong electron acceptors such as tetracyanoquinone dimethane (TCNQ) or 2,3,5,6-tetrafluorotetracyano-1,4-benzoquinone dimethane (F4TCNQ) are used. It is known (e.g., M. Pfeiffer, A. Beyer, T. Fritz, K. Leo, Appl. Phys. Lett., 73(22), 3202-3204 (1998)” and J. Blochwitz , M. Pheiffer, T. Fritz, K. Leo, Appl. Phys. Lett., 73(6), 729-731(1998)). They generate so-called holes by an electron transfer process in an electron donating base material (hole transport material). Depending on the number of holes and the mobility, the conductivity of the base material changes considerably. As a matrix material having hole transport properties, for example, a benzidine derivative (TPD, etc.), a starburst amine derivative (TDATA, etc.), or a specific metal phthalocyanine (in particular, zinc phthalocyanine (ZnPc), etc.) is known (Japanese Patent Laid-Open 2005). -167175).

<Light emitting layer in organic electroluminescent element>

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 applied with an electric field. The material for forming the light-emitting layer 105 may be a compound (luminescent compound) that is excited by recombination of holes and electrons to emit light, and a stable thin film shape can be formed, and strong light emission (fluorescence) efficiency in a solid state. It is preferably a visible compound.

The light-emitting layer may be a single layer or a plurality of layers, and each is formed of a light-emitting layer material (host material, dopant material). The host material and the dopant material may be either one type or a combination of a plurality of them. The dopant material may be included in the entire host material or partially included in the host material. As a doping method, it can be formed by a co-deposition method with a host material, but it is deposited simultaneously after mixing with the host material in advance, or after mixing with the host material in advance with an organic solvent, the film is formed by a wet film forming method. You can do it.

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

The amount of the dopant material used depends on the type of the dopant material, and may be determined according to the characteristics of the dopant material. The basis of the amount of the dopant material used is preferably 0.001 to 50% by weight, more preferably 0.05 to 20% by weight, and still more preferably 0.1 to 10% by weight of the total material for the light emitting layer. In the above range, for example, concentration quenching is preferable in that it can be prevented.

As host materials, condensed cyclic derivatives such as anthracene, pyrene, dibenzochrysene or fluorene, which have been known as light emitters, bisstyryl derivatives such as bisstyrylanthracene derivatives and distyrylbenzene derivatives, tetraphenylbutadiene derivatives, and cyclo Pentadiene derivatives, etc. are mentioned. In particular, an anthracene-based compound, a fluorene-based compound, or a dibenzochrysene-based compound is preferable.

<Electron injection layer and electron transport layer in organic electroluminescent device>

The electron injection layer 107 serves to efficiently inject electrons moving from the cathode 108 into the light emitting layer 105 or into the electron transport layer 106. The electron transport layer 106 serves to efficiently transport electrons injected from the cathode 108 or electrons injected from the cathode 108 through the electron injection layer 107 to the light emitting layer 105. The electron transport layer 106 and the electron injection layer 107 are formed by laminating and mixing one or two or more types of electron transport/injection materials, respectively, or a mixture of an electron transport/injection material and a polymer binder.

The electron injection/transport layer is a layer in which electrons are injected from the cathode and is responsible for transporting electrons. It is preferable that the electron injection efficiency is high and the injected electrons are efficiently transported. For this purpose, it is preferable that the material has high electron affinity, high electron mobility, excellent stability, and difficult to generate trapping impurities during manufacture and use. However, in the case of considering the transport balance of holes and electrons, in the case where the main role is to effectively block the flow of holes from the anode to the cathode side without recombination, the luminous efficiency is improved even if the electron transport capacity is not very high. It has the same effect as a material having a high electron transport ability. Therefore, the electron injection/transport layer in the present embodiment may also contain a function of a layer capable of effectively preventing the movement of holes.

As a material for forming the electron transport layer 106 or the electron injection layer 107 (electron transport material), a compound conventionally used as an electron transport compound in a photoconductive material, an electron injection layer and an electron transport layer of an organic EL device It can be arbitrarily selected and used from known compounds used. In the present invention, as the electron transport material and electron injection material, a polycyclic aromatic compound represented by the general formula (1) and its multimer can be used.

In general, as a material used for the electron transport layer or the electron injection layer, a compound consisting of an aromatic ring or a heteroaromatic ring consisting of at least one atom selected from carbon, hydrogen, oxygen, sulfur, silicon and phosphorus, a pyrrole derivative, and condensation thereof It is preferable to contain at least one selected from ring derivatives and metal complexes having electron-accepting nitrogen. Specifically, condensed ring aromatic ring derivatives such as naphthalene and anthracene, styryl aromatic ring derivatives typified by 4,4'-bis(diphenylethenyl)biphenyl, perinone derivatives, coumarin derivatives, naphthalimide derivatives , Quinone derivatives such as anthraquinone and diphenoquinone, phosphorus oxide derivatives, carbazole derivatives, and indole derivatives. Examples of the electron-accepting nitrogen-containing metal complex include hydroxyazole complexes such as hydroxyphenyloxazole complexes, azomethine complexes, tropolone metal complexes, flavonol metal complexes, and benzoquinoline metal complexes. These materials may be used alone, but may be used by mixing with other materials.

In addition, as specific examples of other electron transfer compounds, pyridine derivatives, naphthalene derivatives, anthracene derivatives, phenanthroline derivatives, perinone derivatives, coumarin derivatives, naphthalimide derivatives, anthraquinone derivatives, diphenoquinone derivatives, diphenylquinone Derivatives, perylene derivatives, oxadiazole derivatives (1,3-bis[(4-t-butylphenyl)1,3,4-oxadiazolyl]phenylene, etc.), thiophene derivatives, triazole derivatives (N- Naphthyl-2,5-diphenyl-1,3,4-triazole, etc.), thiadiazole derivatives, metal complexes of auxin derivatives, quinolinol-based metal complexes, quinoxaline derivatives, polymers of quinoxaline derivatives, benzazoles Compound, gallium complex, pyrazole derivative, perfluorinated phenylene derivative, triazine derivative, pyrazine derivative, benzoquinoline derivative (2,2'-bis(benzo[h]quinolin-2-yl)-9,9' -Spirobifluorene), imidazopyridine derivatives, borane derivatives, benzoimidazole derivatives (tris(N-phenylbenzoimidazol-2-yl)benzene, etc.), benzoxazole derivatives, benzothiazole derivatives, quinoline derivatives , Oligopyridine derivatives such as terpyridine, bipyridine derivatives, terpyridine derivatives (1,3-bis(4'-(2,2':6'2"-terpyridinyl))benzene, etc.), naphthyridine derivatives ( Bis(1-naphthyl)-4-(1,8-naphthyridin-2-yl)phenylphosphine oxide, etc.), aldazine derivatives, carbazole derivatives, indole derivatives, phosphor oxide derivatives, bisstyryl derivatives, etc. Can be lifted.

In addition, metal complexes having electron-accepting nitrogen may be used, for example, hydroxyazole complexes such as quinolinol-based metal complexes and hydroxyphenyloxazole complexes, azomethine complexes, tropolone metal complexes, flavonol metal complexes And a benzoquinoline metal complex.

The above-described materials may be used alone, but may be used by mixing with other materials.

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

<borane derivative>

The borane derivative is, for example, a compound represented by the following general formula (ETM-1), and is specifically disclosed in Japanese Unexamined Patent Application Publication No. 2007-27587.

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

Among the compounds represented by the general formula (ETM-1), a compound represented by the following general formula (ETM-1-1) or a compound represented by the following general formula (ETM-1-2) is preferable.

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

In formula (ETM-1-2), 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 1, R ¹³ to R ¹⁶ are each independently optionally substituted alkyl, optionally substituted cycloalkyl, or optionally substituted aryl, X ¹ is optionally substituted arylene having 20 or less carbon atoms, and n Are each independently an integer of 0-3. In addition, examples of the substituent in the case of "may be substituted" or "substituted" include aryl, heteroaryl, alkyl, or cycloalkyl.

As a specific example of X ¹ , a divalent group represented by any one of following formula (X-1)-formula (X-9) is mentioned.

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

As a specific example of this borane derivative, the following compounds are mentioned, for example.

This borane derivative can be produced using a known raw material and a known synthesis method.

<Pyridine derivative>

The pyridine derivative is, for example, a compound represented by the following formula (ETM-2), and preferably a compound represented by a formula (ETM-2-1) or a formula (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 1 to 4 It is an integer.

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 substituent'' is any one of the following formulas (Py-1) to (Py-15), and the pyridine substituents are each independently C1-C4 alkyl or C5-C10 It may be substituted with cycloalkyl. In addition, the pyridine-based substituent may be bonded to Φ in each formula, an anthracene ring, or a fluorene ring via a phenylene group or a naphthylene group.

The pyridine-based substituent is any one of the above formulas (Py-1) to (Py-15), but among these, it is preferably any one of the following formulas (Py-21) to (Py to 44).

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

As ^{the "alkyl" for R 11} to R ¹⁸ , either linear or branched chain may be used, and examples thereof include straight chain alkyl having 1 to 24 carbon atoms or branched chain alkyl having 3 to 24 carbon atoms. Preferred "alkyl" is alkyl having 1 to 18 carbon atoms (branched alkyl having 3 to 18 carbon atoms). More preferable "alkyl" is C1-C12 alkyl (C3-C12 branched alkyl). A more preferable "alkyl" is C1-C6 alkyl (C3-C6 branched alkyl). Particularly preferred "alkyl" is alkyl having 1 to 4 carbon atoms (branched chain alkyl having 3 to 4 carbon atoms).

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

As the C1-C4 alkyl substituted with the pyridine-based substituent, the description of the above alkyl can be cited.

Examples of the "cycloalkyl" for R ¹¹ to R ¹⁸ include cycloalkyl having 3 to 12 carbon atoms. Preferred "cycloalkyl" is a C3-C10 cycloalkyl. A more preferable "cycloalkyl" is a C3-C8 cycloalkyl. A more preferable "cycloalkyl" is a C3-C6 cycloalkyl.

Specific examples of "cycloalkyl" include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, methylcyclopentyl, cycloheptyl, methylcyclohexyl, cyclooctyl, or dimethylcyclohexyl.

As a C5-C10 cycloalkyl substituted with a pyridine-based substituent, the description of the above cycloalkyl can be cited.

As ^{the "aryl" in R 11} to R ¹⁸ , preferred aryl is a C 6 to C 30 aryl, more preferred aryl is a C 6 to C 18 aryl, more preferably C 6 to C 14 aryl, particularly preferred It is an aryl having 6 to 12 carbon atoms.

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

Preferred "C6-C30 aryl" includes phenyl, naphthyl, phenanthryl, chrysenyl or triphenylenyl, and more preferably phenyl, 1-naphthyl, 2-naphthyl or phenanthryl. And particularly preferably phenyl, 1-naphthyl or 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, in the 5-membered ring of the fluorene skeleton, cyclobutane, cyclopentane, cyclopentene, cyclopentadiene , Cyclohexane, fluorene, indene, or the like may be spiro bonded.

As a specific example of this pyridine derivative, the following compounds are mentioned, for example.

This pyridine derivative can be produced using a known raw material and a known synthesis method.

<Fluoranthene derivative>

The fluoranthene derivative is, for example, a compound represented by the following general formula (ETM-3), and is specifically disclosed in International Publication No. 2010/134352.

In the above formula (ETM-3), X ¹² to X ²¹ are hydrogen, halogen, straight chain, branched or cyclic alkyl, straight chain, branched or cyclic alkoxy, substituted or unsubstituted aryl, or substituted or unsubstituted heteroaryl Represents. Here, examples of the substituent in the case of being substituted include aryl, heteroaryl, alkyl or cycloalkyl.

As a specific example of this fluoranthene derivative, the following compounds are mentioned, for example.

<BO-based derivative>

The BO-based derivative is, for example, a polycyclic aromatic compound represented by the following formula (ETM-4), or a multimer 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, diarylboryl (two aryls may be bonded through a single bond or a linking group) , Alkyl, cycloalkyl, alkoxy or aryloxy, and at least one hydrogen in these may be substituted with aryl, heteroaryl, alkyl, or cycloalkyl.

In addition, ^{adjacent groups among R 1} to R ¹¹ may be bonded to each other to form an aryl ring or heteroaryl ring together with the a ring, b ring, or c ring, and at least one hydrogen in the formed ring is aryl or heteroaryl. , Diarylamino, diheteroarylamino, arylheteroarylamino, diarylboryl (two aryls may be bonded through a single bond or a linking group), alkyl, cycloalkyl, alkoxy or aryloxy may be substituted, At least one hydrogen in these may be substituted with aryl, heteroaryl, alkyl or cycloalkyl.

Further, at least one hydrogen in the compound or structure represented by formula (ETM-4) may be substituted with halogen or deuterium.

Description of the form of the substituent or ring formation in the formula (ETM-4), and for the multimer formed by combining a plurality of structures of the formula (ETM-4), the polycyclic ring represented by the general formula (1) or (2) A description of the aromatic compound or its multimer can be cited.

As a specific example of this BO-based derivative, the following compounds are mentioned, for example.

This BO-based derivative can be produced using a known raw material and a known synthesis method.

<Anthracene derivative>

One of the anthracene derivatives is, for example, a compound represented by the following formula (ETM-5-1).

Ar is each independently divalent benzene or naphthalene, and R ¹ to R ⁴ are each independently hydrogen, alkyl having 1 to 6 carbon atoms, cycloalkyl having 3 to 6 carbon atoms, or aryl having 6 to 20 carbon atoms.

Ar can each independently be appropriately selected from divalent benzene or naphthalene, and may be the same even if the two Ar are different, but the same is preferable from the viewpoint of easy synthesis of an anthracene derivative. Ar is bonded to pyridine to form a "site consisting of Ar and pyridine", and this site is bound to anthracene as a group represented by any of the following formulas (Py-1) to (Py-12). .

Among these groups, a group represented by any of the formulas (Py-1) to (Py-9) is preferable, and a group represented by any of the formulas (Py-1) to (Py-6) is more preferable. Two "sites consisting of Ar and pyridine" bonded to anthracene may have the same or different structures, but are preferably the same structure from the viewpoint of easy synthesis of anthracene derivatives. However, from the viewpoint of device characteristics, it is preferable that the structures of the two "sites consisting of Ar and pyridine" are the same or different.

Regarding the alkyl having 1 to 6 carbon atoms in R ¹ to R ^{4, either linear or branched chain may be used.} That is, it is C1-C6 linear alkyl or C3-C6 branched alkyl. More preferably, it is C1-C4 alkyl (C3-C4 branched alkyl). Specific examples include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, s-butyl, t-butyl, n-pentyl, isopentyl, neopentyl, t-pentyl, n-hexyl, 1-methyl Pentyl, 4-methyl-2-pentyl, 3,3-dimethylbutyl or 2-ethylbutyl, and the like, 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 in R ¹ to R ⁴ include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, methylcyclopentyl, cycloheptyl, methylcyclohexyl, cyclooctyl or dimethylcyclohexyl. Can be lifted.

About ^{the aryl having 6 to 20 carbon atoms in R 1} to R ⁴ , 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.

As a specific example of ``C6-C20 aryl'', monocyclic aryl 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 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 arylin, anthracene-(1-, 2-, 9-)yl, acenaphthylene-(1- , 3-, 4-, 5-)yl, fluorene-(1-, 2-, 3-, 4-, 9-)yl, phenalen-(1-, 2-)yl, (1-, 2 -, 3-, 4-, 9-) phenanthryl, condensed tetracyclic aryl triphenylene-(1-, 2-)yl, pyrene-(1-, 2-, 4-)yl, tetracene-( 1-, 2-, 5-)yl, perylene-(1-, 2-, 3-)yl which is a condensed pentacyclic aryl, etc. are mentioned.

Preferred "C6-C20 aryl" is phenyl, biphenylyl, terphenylyl or naphthyl, more preferably phenyl, biphenylyl, 1-naphthyl, 2-naphthyl, or m-terphenyl- 5′-yl, more preferably phenyl, biphenylyl, 1-naphthyl or 2-naphthyl, most preferably phenyl.

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

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

Each of 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. C6-C16 aryl is preferable, C6-C12 aryl is more preferable, and C6-C10 aryl is especially preferable. Specific examples include phenyl, biphenylyl, naphthyl, terphenylyl, anthracenyl, acenaphthylenyl, fluorenyl, phenalenyl, phenanthryl, triphenylenyl, pyrenyl, tetracenyl, perylenyl, and the like. I can.

R ¹ to R ⁴ are each independently hydrogen, C 1 to C 6 alkyl, C 3 to C 6 cycloalkyl or C 6 to C 20 aryl, and the description in the above formula (ETM-5-1) is cited. I can.

As a specific example of these anthracene derivatives, the following compounds are mentioned, for example.

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

<Benzofluorene derivative>

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

Each of 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 formula (ETM-5-1) can be cited. C6-C16 aryl is preferable, C6-C12 aryl is more preferable, and C6-C10 aryl is especially preferable. Specific examples include phenyl, biphenylyl, naphthyl, terphenylyl, anthracenyl, acenaphthylenyl, fluorenyl, phenalenyl, phenanthryl, triphenylenyl, pyrenyl, tetracenyl, perylenyl, and the like. I can.

Ar ² is 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), Two Ar ² may be bonded to each other to form a ring.

As ^{the "alkyl" in Ar 2} , either linear or branched chain may be used, and examples thereof include straight chain alkyl having 1 to 24 carbon atoms or branched chain alkyl having 3 to 24 carbon atoms. Preferred "alkyl" is alkyl having 1 to 18 carbon atoms (branched alkyl having 3 to 18 carbon atoms). More preferable "alkyl" is C1-C12 alkyl (C3-C12 branched alkyl). A more preferable "alkyl" is C1-C6 alkyl (C3-C6 branched alkyl). Particularly preferred "alkyl" is alkyl having 1 to 4 carbon atoms (branched chain 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.

As ^{the "cycloalkyl" in Ar 2} , cycloalkyl having 3 to 12 carbon atoms is mentioned, for example. Preferred "cycloalkyl" is a C3-C10 cycloalkyl. A more preferable "cycloalkyl" is a C3-C8 cycloalkyl. A more preferable "cycloalkyl" is a C3-C6 cycloalkyl. Specific examples of "cycloalkyl" include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, methylcyclopentyl, cycloheptyl, methylcyclohexyl, cyclooctyl, or dimethylcyclohexyl.

As ^{the "aryl" in Ar 2} , preferred aryl is an aryl having 6 to 30 carbon atoms, more preferred aryl is an aryl having 6 to 18 carbon atoms, more preferably an aryl having 6 to 14 carbon atoms, particularly preferably It is 6-12 aryl.

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

Two Ar ² may be bonded to form a ring, and as a result, cyclobutane, cyclopentane, cyclopentene, cyclopentadiene, cyclohexane, fluorene, indene, and the like are spiro bonded to the 5-membered ring of the fluorene skeleton. You may have it.

As a specific example of this benzofluorene derivative, the following compounds are mentioned, for example.

This benzofluorene derivative can be produced using a known raw material and a known synthesis method.

<phosphine oxide derivative>

The phosphine oxide derivative is, for example, a compound represented by the following formula (ETM-7-1). Details are also described in International Publication No. 2013/079217.

R ⁵ is a substituted or unsubstituted alkyl having 1 to 20 carbon atoms, cycloalkyl having 3 to 20 carbon atoms, aryl having 6 to 20 carbon atoms or heteroaryl having 5 to 20 carbon atoms,

R ⁶ is CN, substituted or unsubstituted, alkyl having 1 to 20 carbon atoms, cycloalkyl having 3 to 20 carbon atoms, heteroalkyl having 1 to 20 carbon atoms, aryl having 6 to 20 carbon atoms, heteroaryl having 5 to 20 carbon atoms, and 1-20 alkoxy or C6-C20 aryloxy,

R ⁷ and R ⁸ are each independently substituted or unsubstituted, aryl having 6 to 20 carbon atoms or heteroaryl having 5 to 20 carbon atoms,

R ⁹ 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.

Here, examples of the substituent in the case of being substituted include 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 hydrogen, alkyl group, cycloalkyl group, aralkyl group, alkenyl group, cycloalkenyl group, alkynyl group, alkoxy group, alkylthio group, cycloalkylthio group, aryl ether group, arylthioether It is selected from a group, aryl group, heterocyclic group, halogen, cyano group, aldehyde group, carbonyl group, carboxyl group, amino group, nitro group, silyl group, and a condensed ring formed between adjacent substituents.

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

Among these substituents, the alkyl group represents, for example, a saturated aliphatic hydrocarbon group such as a methyl group, an ethyl group, a propyl group, or a butyl group, which may be unsubstituted or substituted. There is no restriction|limiting in particular in the substituent when substituted, For example, an alkyl group, an aryl group, a heterocyclic group, etc. are mentioned, and these points are also common to the following description. In addition, the number of carbon atoms of the alkyl group is not particularly limited, but is usually in the range of 1 to 20 from the viewpoint of availability and cost.

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

In addition, the aralkyl group represents an aromatic hydrocarbon group through an aliphatic hydrocarbon such as a benzyl group or a phenylethyl group, and both aliphatic hydrocarbons and aromatic hydrocarbons may be unsubstituted or substituted. The number of carbon atoms in the aliphatic moiety is not particularly limited, but is usually in the range of 1 to 20.

In addition, an alkenyl group represents an unsaturated aliphatic hydrocarbon group containing a double bond, such as a vinyl group, an allyl group, and a butadienyl group, which may be unsubstituted or substituted. Although the number of carbon atoms of the alkenyl group is not particularly limited, it is usually in the range of 2 to 20.

In addition, the cycloalkenyl group represents an unsaturated alicyclic hydrocarbon group containing a double bond, such as a cyclopentenyl group, a cyclopentadienyl group, and a cyclohexene group, which may be unsubstituted or substituted.

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

In addition, the alkoxy group represents an aliphatic hydrocarbon group through an ether bond such as a methoxy group, and the aliphatic hydrocarbon group may be unsubstituted or substituted. Although the number of carbon atoms of the alkoxy group is not particularly limited, it is usually in the range of 1 to 20.

In addition, the alkylthio group is a group in which the oxygen atom of the ether bond of the alkoxy group is substituted with a sulfur atom.

In addition, the cycloalkylthio group is a group in which the oxygen atom of the ether bond of the cycloalkoxy group is substituted with a sulfur atom.

In addition, the aryl ether group represents an aromatic hydrocarbon group through an ether bond such as a phenoxy group, 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.

In addition, the arylthioether group is a group in which the oxygen atom of the ether bond of the aryl ether group is substituted with a sulfur atom.

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

In addition, the heterocyclic group refers to a cyclic structural group having an atom other than carbon such as a furanyl group, a thiophenyl group, an oxazolyl group, a pyridyl group, a quinolinyl group, and a carbazolyl group, which is substituted even if it is unsubstituted It doesn't matter if there is. The number of carbon atoms of the heterocyclic group is not particularly limited, but is usually in the range of 2 to 30.

Halogen represents fluorine, chlorine, bromine, and iodine.

The aldehyde group, carbonyl group, and amino group may contain groups substituted with aliphatic hydrocarbons, alicyclic hydrocarbons, aromatic hydrocarbons, and heterocycles.

In addition, aliphatic hydrocarbon, alicyclic hydrocarbon, aromatic hydrocarbon, and heterocycle may be unsubstituted or substituted.

The silyl group represents, for example, a silicon compound group such as a trimethylsilyl group, and may be unsubstituted or substituted. The number of carbon atoms in the silyl group is not particularly limited, but is usually in the range of 3 to 20. In addition, the number of silicon is usually 1-6.

The condensed ring formed between adjacent substituents is, for example, Ar ¹ and R ² , Ar ¹ and R ³ , Ar ² and R ² , Ar ² and R ³ , R ² and R ³ , Ar ¹ and Ar ^It is a conjugated or non-conjugated condensed ring formed between 2 and the like. Here, when n is 1, two R ^1s may form a conjugated or non-conjugated condensed ring. These condensed rings may contain nitrogen, oxygen, and sulfur atoms in the intra-ring structure, or may be further condensed with other rings.

As a specific example of this phosphine oxide derivative, the following compounds are mentioned, for example.

This phosphine oxide derivative can be produced using a known raw material and a known synthesis method.

<Pyrimidine derivative>

The pyrimidine derivative is, for example, a compound represented by the following formula (ETM-8), and preferably a compound represented by the following formula (ETM-8-1). Details are also described in International Publication No. 2011/021689.

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

As the "aryl" of the "optionally substituted aryl", for example, an aryl having 6 to 30 carbon atoms is exemplified, preferably an aryl having 6 to 24 carbon atoms, more preferably an aryl having 6 to 20 carbon atoms, further Preferably, it is a C6-C12 aryl.

Specific examples of "aryl" include monocyclic aryl phenyl, bicyclic aryl (2-, 3-, 4-)biphenylyl, condensed bicyclic aryl (1-, 2-)naphthyl, and tricyclic aryl ter Phenylyl (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 phosphorus , 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, quarterphenylyl (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-) days, etc. are mentioned.

Examples of the "heteroaryl" of "heteroaryl which may be substituted" include, for example, heteroaryl having 2 to 30 carbon atoms, heteroaryl having 2 to 25 carbon atoms is preferable, and heteroaryl having 2 to 20 carbon atoms is It is more preferable, a C2-C15 heteroaryl is still more preferable, and a C2-C10 heteroaryl is especially preferable. Further, examples of the heteroaryl include, for example, a heterocycle containing 1 to 5 heteroatoms selected from oxygen, sulfur and nitrogen in addition to carbon as a ring constituent atom.

As a specific heteroaryl, for example, furyl, thienyl, pyrroleyl, oxazolyl, isoxazolyl, thiazolyl, isothiazolyl, imidazolyl, pyrazolyl, oxadiazolyl, furazanyl, thiadiazolyl, tria Zolyl, tetrazolyl, pyridyl, pyrimidinyl, pyridazinyl, pyrazinyl, triazinyl, benzofuranyl, isobenzofuranyl, benzo[b]thienyl, indolyl, isoindolyl, 1H-indazolyl, Benzoimidazolyl, benzoxazolyl, benzothiazolyl, 1H-benzotriazolyl, quinolyl, isoquinolyl, cinnolyl, quinazolyl, quinoxalinyl, phthalazinyl, naphthyridinyl, purinyl, pteridinyl , Carbazolyl, acridinyl, phenoxazinyl, phenothiazinyl, phenazinyl, phenoxatiinyl, thianthrenyl, indolizinyl, and the like.

In addition, the aryl and heteroaryl may be substituted, and may each be substituted with, for example, the aryl or heteroaryl.

As a specific example of this pyrimidine derivative, the following compounds are mentioned, for example.

This pyrimidine derivative can be produced using a known raw material and a known synthesis method.

<Carbazole derivatives>

The carbazole derivative is, for example, a compound represented by the following formula (ETM-9), or a multimer in which a plurality of these are bonded by a single bond or the like. Details are described in US Publication No. 2014/0197386

Ar is each independently optionally substituted aryl or optionally substituted heteroaryl. n is an integer of 0-4, Preferably it is an integer of 0-3, More preferably, it is 0 or 1.

As the "aryl" of the "optionally substituted aryl", for example, an aryl having 6 to 30 carbon atoms is exemplified, preferably an aryl having 6 to 24 carbon atoms, more preferably an aryl having 6 to 20 carbon atoms, further Preferably, it is a C6-C12 aryl.

Specific examples of "aryl" include monocyclic aryl phenyl, bicyclic aryl (2-, 3-, 4-)biphenylyl, condensed bicyclic aryl (1-, 2-)naphthyl, and tricyclic aryl ter Phenylyl (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 phosphorus , 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, quarterphenylyl (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-) days, etc. are mentioned.

Examples of the "heteroaryl" of "heteroaryl which may be substituted" include, for example, heteroaryl having 2 to 30 carbon atoms, heteroaryl having 2 to 25 carbon atoms is preferable, and heteroaryl having 2 to 20 carbon atoms is It is more preferable, a C2-C15 heteroaryl is still more preferable, and a C2-C10 heteroaryl is especially preferable. Further, examples of the heteroaryl include, for example, a heterocycle containing 1 to 5 heteroatoms selected from oxygen, sulfur and nitrogen in addition to carbon as a ring constituent atom.

As a specific heteroaryl, for example, furyl, thienyl, pyrroleyl, oxazolyl, isoxazolyl, thiazolyl, isothiazolyl, imidazolyl, pyrazolyl, oxadiazolyl, furazanyl, thiadiazolyl, tria Zolyl, tetrazolyl, pyridyl, pyrimidinyl, pyridazinyl, pyrazinyl, triazinyl, benzofuranyl, isobenzofuranyl, benzo[b]thienyl, indolyl, isoindolyl, 1H-indazolyl, Benzoimidazolyl, benzoxazolyl, benzothiazolyl, 1H-benzotriazolyl, quinolyl, isoquinolyl, cinnolyl, quinazolyl, quinoxalinyl, phthalazinyl, naphthyridinyl, purinyl, pteridinyl , Carbazolyl, acridinyl, phenoxazinyl, phenothiazinyl, phenazinyl, phenoxatiinyl, thianthrenyl, indolizinyl, and the like.

In addition, the aryl and heteroaryl may be substituted, and each may be substituted with, for example, the aryl or heteroaryl.

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

As a specific example of this carbazole derivative, the following compounds are mentioned, for example.

This carbazole derivative can be produced using a known raw material and a known synthesis method.

<triazine derivative>

The triazine derivative is, for example, a compound represented by the following formula (ETM-10), and preferably a compound represented by the following formula (ETM-10-1). Details are set forth in US Publication No. 2011/0156013.

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

As the "aryl" of the "optionally substituted aryl", for example, an aryl having 6 to 30 carbon atoms is exemplified, preferably an aryl having 6 to 24 carbon atoms, more preferably an aryl having 6 to 20 carbon atoms, further Preferably, it is a C6-C12 aryl.

Specific examples of "aryl" include monocyclic aryl phenyl, bicyclic aryl (2-, 3-, 4-)biphenylyl, condensed bicyclic aryl (1-, 2-)naphthyl, and tricyclic aryl ter Phenylyl (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 phosphorus , 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, quarterphenylyl (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-) days, etc. are mentioned.

Examples of the "heteroaryl" of "heteroaryl which may be substituted" include, for example, heteroaryl having 2 to 30 carbon atoms, heteroaryl having 2 to 25 carbon atoms is preferable, and heteroaryl having 2 to 20 carbon atoms is It is more preferable, a C2-C15 heteroaryl is still more preferable, and a C2-C10 heteroaryl is especially preferable. Further, examples of the heteroaryl include, for example, a heterocycle containing 1 to 5 heteroatoms selected from oxygen, sulfur and nitrogen in addition to carbon as a ring constituent atom.

As a specific heteroaryl, for example, furyl, thienyl, pyrroleyl, oxazolyl, isoxazolyl, thiazolyl, isothiazolyl, imidazolyl, pyrazolyl, oxadiazolyl, furazanyl, thiadiazolyl, tria Zolyl, tetrazolyl, pyridyl, pyrimidinyl, pyridazinyl, pyrazinyl, triazinyl, benzofuranyl, isobenzofuranyl, benzo[b]thienyl, indolyl, isoindolyl, 1H-indazolyl, Benzoimidazolyl, benzoxazolyl, benzothiazolyl, 1H-benzotriazolyl, quinolyl, isoquinolyl, cinnolyl, quinazolyl, quinoxalinyl, phthalazinyl, naphthyridinyl, purinyl, pteridinyl , Carbazolyl, acridinyl, phenoxazinyl, phenothiazinyl, phenazinyl, phenoxatiinyl, thianthrenyl, indolizinyl, and the like.

In addition, the aryl and heteroaryl may be substituted, and each may be substituted with, for example, the aryl or heteroaryl.

As a specific example of this triazine derivative, the following compounds are mentioned, for example.

This triazine derivative can be produced using a known raw material and a known synthesis method.

<Benzoimidazole derivatives>

Benzoimidazole derivatives are compounds represented by the following formula (ETM-11), for example.

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 1 to 4 It is an integer, and the "benzoimidazole-based substituent" is a pyridyl group among the "pyridine-based substituents" in the above formulas (ETM-2), (ETM-2-1) and formula (ETM-2-2). It is a substituent substituted with an imidazole group, and at least one hydrogen in the benzoimidazole derivative may be substituted with deuterium.

^{R 11} in the benzoimidazole group is hydrogen, alkyl having 1 to 24 carbon atoms, cycloalkyl having 3 to 12 carbon atoms, or aryl having 6 to 30 carbon atoms, wherein the formula (ETM-2-1) and formula (ETM- ^{The description of R 11} in 2-2) can be cited.

Φ is also preferably an anthracene ring or a fluorene ring, and the structure in this case can refer to the description in the above formula (ETM-2-1) or (ETM-2-2), and R in each formula ¹¹ to R ¹⁸ can refer to the description in the above formula (ETM-2-1) or (ETM-2-2). In addition, in the above formula (ETM-2-1) or (ETM-2-2), two pyridine-based substituents are combined, but when replacing them with a benzoimidazole-based substituent, both pyridine-based substituents May be substituted with a benzoimidazole-based substituent (i.e., n=2), any one pyridine-based substituent may be substituted with a benzoimidazole-based substituent, and the other pyridine-based substituent may be substituted with R ¹¹ to R ¹⁸ (I.e., n=1). In addition, for example, even if ^{at least one of R 11} to R ¹⁸ in the above formula (ETM-2-1) is substituted with a benzoimidazole-based substituent, and “pyridine-based substituent” is substituted with R ¹¹ to R ¹⁸ do.

Specific examples of this benzoimidazole derivative include, for example, 1-phenyl-2-(4-(10-phenylanthracene-9-yl)phenyl)-1H-benzo[d]imidazole, 2-(4-( 10-(naphthalen-2-yl)anthracene-9-yl)phenyl)-1-phenyl-1H-benzo[d]imidazole, 2-(3-(10-(naphthalen-2-yl)anthracene-9- Yl)phenyl)-1-phenyl-1H-benzo[d]imidazole, 5-(10-(naphthalen-2-yl)anthracene-9-yl)-1,2-diphenyl-1H-benzo[d] Imidazole, 1-(4-(10-(naphthalen-2-yl)anthracene-9-yl)phenyl)-2-phenyl-1H-benzo[d]imidazole, 2-(4-(9,10- Di(naphthalen-2-yl)anthracen-2-yl)phenyl)-1-phenyl-1H-benzo[d]imidazole, 1-(4-(9,10-di(naphthalen-2-yl)anthracene- 2-yl)phenyl)-2-phenyl-1H-benzo[d]imidazole, 5-(9,10-di(naphthalen-2-yl)anthracen-2-yl)-1,2-diphenyl-1H -Benzo[d]imidazole, etc. are mentioned.

This benzoimidazole derivative can be produced using a known raw material and a known synthesis method.

<Phenanthroline derivative>

The phenanthroline derivative is, for example, a compound represented by the following formula (ETM-12) or (ETM-12-1). Details are described in International Publication No. 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 1 to 4 It is an integer.

^{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 6 carbon atoms) ~30 aryl). Further, in the above formula (ETM-12-1), ^{any one 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 substituted with deuterium,

As the alkyl, cycloalkyl and aryl in R ¹¹ ~ R ^18, it is possible to cite the description of the formula the R ¹¹ ~ R ¹⁸ in (ETM-2). In addition, in addition to the above-described examples, Φ includes, for example, the following structural formula. In addition, R in the following structural formula is each independently hydrogen, methyl, ethyl, isopropyl, cyclohexyl, phenyl, 1-naphthyl, 2-naphthyl, biphenylyl, or terphenylyl.

Specific examples of this phenanthroline derivative include, for example, 4,7-diphenyl-1,10-phenanthroline, 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline, and 9 ,10-di(1,10-phenanthrolin-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), vasocuproin, 1,3-bis(2-phenyl- 1,10-phenanthroline-9-yl)benzene, a compound represented by the following structural formula, etc. are mentioned.

This phenanthroline derivative can be produced using a known raw material and a known synthesis method.

<Quinolinol-based metal complex>

The quinolinol-based metal complex is, for example, a compound represented by the following general formula (ETM-13).

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

Specific examples of the quinolinol-based metal complex include 8-quinolinol lithium, tris(8-quinolinolate) aluminum, tris(4-methyl-8-quinolinolate) aluminum, and tris(5-methyl-8-) Quinolinolate) aluminum, tris (3,4-dimethyl-8-quinolinolate) aluminum, tris (4,5-dimethyl-8-quinolinolate) aluminum, tris (4,6-dimethyl-8 -Quinolinoleate) aluminum, 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)(3-phenylphenolate)aluminum, bis(2-methyl-8-quinolinolate) (4-phenylphenolate) aluminum, bis (2-methyl-8-quinolinolate) (2,3-dimethylphenolate) aluminum, bis (2-methyl-8-quinolinolate) (2,6 -Dimethylphenolate) aluminum, bis(2-methyl-8-quinolinolate)(3,4-dimethylphenolate)aluminum, bis(2-methyl-8-quinolinolate)(3,5-dimethyl Phenolate) 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-quinoli) Nolate) (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-phenylphenol Rate) aluminum, bis (2,4-dimethyl-8-quinolinolate) (3,5-dimethylphenolate) Aluminum, bis(2,4-dimethyl-8-quinolinolate)(3,5-di-t-butylphenolate)aluminum, bis(2-methyl-8-quinolinolate)aluminum-μ-oxo -Bis(2-methyl-8-quinolinolate) aluminum, bis(2,4-dimethyl-8-quinolinolate) aluminum-μ-oxo-bis(2,4-dimethyl-8-quinolinol) Rate) 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, bis(2-methyl-5-cyano -8-quinolinolate)aluminum-μ-oxo-bis(2-methyl-5-cyano-8-quinolinolate)aluminum, bis(2-methyl-5-trifluoromethyl-8-qui Nolinoleate)aluminum-μ-oxo-bis(2-methyl-5-trifluoromethyl-8-quinolinolate)aluminum, bis(10-hydroxybenzo[h]quinoline)beryllium, etc. are mentioned. .

This quinolinol-based metal complex can be produced using a known raw material and a known synthesis method.

<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 a compound represented by the following formula (ETM-14-2), for example.

Φ in each formula 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 1 It is an integer of ~4, and "thiazole-based substituent" or "benzothiazole-based substituent" is a "pyridine" in the above formulas (ETM-2), (ETM-2-1) and (ETM-2-2) The pyridyl group is a substituent substituted with a thiazole group or a benzothiazole group as described below, and at least one hydrogen in the thiazole derivative and the benzothiazole derivative may be substituted with deuterium.

Φ is also preferably an anthracene ring or a fluorene ring, and the structure in this case can refer to the description in the above formula (ETM-2-1) or (ETM-2-2), R ¹¹ to R ¹⁸ may refer to the description in the above formula (ETM-2-1) or (ETM-2-2). Further, in the above formula (ETM-2-1) or (ETM-2-2), two pyridine-based substituents are combined, but when these are substituted with a thiazole-based substituent (or benzothiazole-based substituent), Both pyridine-based substituents may be substituted with thiazole-based substituents (or benzothiazole-based substituents) (i.e., n=2), and any one pyridine-based substituent is substituted with a thiazole-based substituent (or benzothiazole-based substituent), and another You may substitute the other pyridine-based substituent with R ¹¹ to R ¹⁸ (that is, n=1). ^{In addition, for example, at least one of R 11} to R ¹⁸ in the above formula (ETM-2-1) is substituted with a thiazole-based substituent (or benzothiazole-based substituent), and the ``pyridine-based substituent'' is replaced with R ¹¹ to R ^You may substitute 18.

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

The electron transport layer or the electron injection layer may further contain a material capable of reducing the material for forming the electron transport layer or the electron injection layer. As long as the reducing substance has a certain reducibility, various substances can be used. For example, alkali metal, alkaline earth metal, rare earth metal, oxide of alkali metal, halide of alkali metal, oxide of alkaline earth metal, alkali At least one selected from the group consisting of halides of earth metals, oxides of rare earth metals, halides of rare earth metals, organic complexes of alkali metals, organic complexes of alkaline earth metals, and organic complexes of rare earth metals can be preferably used. .

Preferred reducing substances include alkali metals such as Na (work function 2.36 eV), K (copper 2.28 eV), Rb (copper 2.16 eV) or Cs (copper 1.95 eV), Ca (copper 2.9 eV), Sr (copper 2.0 -2.5 eV) or Ba (copper 2.52 eV), and other alkaline earth metals, and a material having a work function of 2.9 eV or less is particularly preferable. Among these, a more preferable reducing substance is an alkali metal of K, Rb or Cs, more preferably Rb or Cs, and most preferable is Cs. These alkali metals have a particularly high reducing ability, and by adding a relatively small amount to a material forming the electron transport layer or the electron injection layer, the luminance of light emission in the organic EL device and the lifespan thereof are increased. In addition, as a reducing material having a work function of 2.9 eV or less, a combination of two or more alkali metals is also preferable, and in particular, a combination containing Cs, for example, Cs and Na, Cs and K, Cs and Rb, or Cs And a combination of Na and K is preferred. By containing Cs, the reducing ability can be exhibited efficiently, and by addition to a material for forming an electron transport layer or an electron injection layer, the luminance of light emission in the organic EL device is improved and the lifespan thereof is increased.

<Cathode in organic electroluminescent device>

The cathode 108 serves to inject electrons into the light emitting layer 105 through the electron injection layer 107 and the electron transport layer 106.

The material for forming the cathode 108 is not particularly limited as long as it is a material capable of efficiently injecting electrons into the organic layer, but the same material as the material 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.) and the like are preferable. In order to increase the electron injection efficiency and improve device characteristics, lithium, sodium, potassium, cesium, calcium, magnesium, or an alloy containing these low work function metals is effective. However, these low work function metals are generally unstable in the atmosphere in many cases. In order to improve this point, for example, a method of using an electrode having high stability by doping an organic layer with a trace amount of lithium, cesium or magnesium is known. As other dopants, inorganic salts such as lithium fluoride, cesium fluoride, lithium oxide and cesium oxide can also be used. However, it is not limited to these.

In addition, for electrode protection, metals such as platinum, gold, silver, copper, iron, tin, aluminum, and indium, or alloys using these metals, and inorganic substances such as silica, titania and silicon nitride, polyvinyl alcohol, vinyl chloride, hydrocarbon-based Laminating a polymer compound or the like is exemplified as a preferred example. The manufacturing method of these electrodes is not particularly limited as long as conduction can be achieved, such as resistance heating, electron beam evaporation, sputtering, ion plating and coating.

<Binder that can be used in each layer>

Materials used for the above hole injection layer, hole transport layer, light emitting layer, electron transport layer, and electron injection layer can form each layer independently, but polyvinyl chloride, polycarbonate, polystyrene, poly(N-vinylcar) as a polymer binder Bazol), polymethyl methacrylate, polybutyl methacrylate, polyester, polysulfone, polyphenylene oxide, polybutadiene, hydrocarbon resin, ketone resin, phenoxy resin, polyamide, ethyl cellulose, vinyl acetate resin, ABS Disperse in solvent-soluble resins such as 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, silicone resins, etc. It is also possible to do.

<Method of manufacturing organic electroluminescent device>

Each layer constituting the organic EL device is a thin film using a method such as vapor deposition, resistance heating vapor deposition, electron beam vapor deposition, sputtering, molecular lamination method, printing method, spin coat method, cast method, coating method, etc. It can be formed by setting it as. The film thickness of each layer thus formed is not particularly limited, and can be appropriately set according to the properties of the material, but is usually in the range of 2 nm to 5000 nm. The film thickness can usually be measured with a crystal oscillation type film thickness measuring device or the like. In the case of forming a thin film using a vapor deposition method, the vapor deposition conditions differ depending on the type of material, the target crystal structure and association structure of the film, and the like. Deposition conditions are generally boat heating temperature +50~+400℃, vacuum degree 10 ^-6 ~10 ^-3 Pa, deposition rate 0.01~50nm/sec, substrate temperature -150~+300℃, film thickness 2nm~5㎛ It is desirable to set appropriately within the range of.

Next, as an example of a method of manufacturing an organic EL device, a method of manufacturing an organic EL device comprising an anode/hole injection layer/hole transport layer/light emitting layer/electron transport layer/electron injection layer/cathode made of a host material and a dopant material will be described. do. On a suitable substrate, a thin film of an anode material is formed by a vapor deposition method or the like to prepare an anode, and then a thin film of a hole injection layer and a hole transport layer is formed on the anode. On this, a host material and a dopant material are co-deposited (codeposition), a thin film is formed to form a light emitting layer, and an electron transport layer and an electron injection layer are formed on the light emitting layer, and a thin film made of a material for a cathode is formed as a cathode by evaporation or the like. By doing so, a desired organic EL device is obtained. Further, in the fabrication of the organic EL device described above, it is also possible to reverse the fabrication order and fabricate in the order of a cathode, an electron injection layer, an electron transport layer, a light-emitting layer, a hole transport layer, a hole injection layer, and an anode.

In the case of applying a DC voltage to the organic EL device thus obtained, it is sufficient to apply the anode with the polarity of + and the cathode with the polarity of -. When a voltage of about 2 to 40 V is applied, the transparent or semi-transparent electrode side (anode or cathode and Light emission from both) can be observed. Further, this organic EL element emits light even when a pulse current or an alternating current is applied. In addition, the waveform of the alternating current to be applied may be arbitrary.

<Application example of organic electroluminescent device>

Further, the present invention can be applied to a display device including an organic EL element or a lighting device including an organic EL element.

A display device or a lighting device equipped with an organic EL element can be manufactured by a known method such as connecting such an organic EL element and a known driving device to the present embodiment, and known such as direct current driving, pulse driving, and alternating current driving. It can be driven by appropriately using the driving method of

Examples of the display device include panel displays such as color flat panel displays, and flexible displays such as flexible color organic electroluminescence (EL) displays (for example, Japanese Unexamined Patent Publication No. Hei 10-335066, Japanese Patent Laid-Open No. 2003-321546, Japanese Patent Laid-Open No. 2004-281086, etc.). Moreover, as a display system of a display, a matrix and/or a segment system, etc. are mentioned, for example. Further, the matrix display and the segment display may coexist in the same panel.

In a matrix, pixels for display are arranged two-dimensionally, such as a grid or a mosaic, and characters and images are displayed as a set of pixels. The shape or size of the pixel is determined according to the application. For example, in PCs, monitors, and television images and characters, a square pixel with a side of 300 μm or less is usually used, and in the case of a large display such as a display panel, a pixel of the order of mm is used. do. In the case of a monochrome display, pixels of the same color may be arranged, but in the case of a color display, red, green, and blue pixels are arranged and displayed. In this case, there are typically a delta type and a stripe type. As a driving method of this matrix, either a linear-sequential driving method or an active matrix may be used. Line-sequential driving has the advantage that the structure is simple, but when the operation characteristics are taken into consideration, the active matrix may be excellent, and thus it is necessary to use differently depending on the application.

In the segment method (type), a pattern is formed to display predetermined information, and a predetermined area is emitted. For example, display of time and temperature on a digital clock or thermometer, display of operating states of audio equipment and electronic cookers, and panel display of automobiles are exemplified.

Examples of the lighting device include lighting devices such as indoor lighting, backlights for liquid crystal displays, and the like (for example, Japanese Unexamined Patent Publication No. 2003-257621, Japanese Unexamined Patent Publication No. 2003-277741, and Japanese Patent Publication No. 2004-119211, etc.). The backlight is mainly used for the purpose of improving the visibility of a display device that does not emit light, and is used for a liquid crystal display device, a clock, an audio device, an automobile panel, a display panel, and a sign. In particular, as a backlight for a liquid crystal display device, especially for a PC whose thickness reduction is a problem, considering that it is difficult to reduce the thickness since the conventional method consists of a fluorescent lamp or a light guide plate, the backlight using the light emitting element according to the present embodiment is thin. It is characterized by light weight.

[Example]

Hereinafter, the present invention will be described more specifically by way of examples, but the present invention is not limited thereto. First, a synthesis example of a polycyclic aromatic compound is described below.

Synthesis Example (1): Synthesis of Compound (1-101)

1,3-dibromo-5-fluorobenzene (50.0 g), carbazole (36.2 g), potassium carbonate (54.0 g) and N-methylpyrrolidone (NMP, 250 mL) were added to a flask under a nitrogen atmosphere. And stirred at 170°C for 6 hours. After the reaction, the reaction solution was cooled, water was added, and the precipitate was filtered. The precipitate was washed with water and methanol and dried, followed by purification with a silica gel column (eluent: toluene/heptane = 2/8 (volume ratio)), and further dissolving the crude body in toluene and reprecipitating with heptane. (A) was obtained (55.3 g).

Compound (A) (25.0 g), 3-(2-methylphenyl) phenol (25.2 g), copper iodide (0.60 g), tris (acetylacetonato) iron (2.20 g), potassium carbonate (34.0 g) and N- Methylpyrrolidone (NMP, 100 mL) was placed in a flask under a nitrogen atmosphere, and stirred at 150°C for 3 hours. After the reaction, the reaction solution was cooled, NMP was distilled off under reduced pressure, water and ethyl acetate were added to the residue, stirred, and then filtered through Celite (registered trademark). Ammonia water was added to the filtrate, the water layer was removed after stirring, and the organic layer was washed with water twice, and the organic layer was concentrated under reduced pressure. The obtained crude product was purified by a silica gel column (eluent: toluene/heptane = 3/7 (volume ratio)) to obtain compound (B) (28.1 g).

In a flask containing compound (B) (25.0 g) and xylene (140 ml), while cooling with an ice bath under a nitrogen atmosphere, s-butyllithium/cyclohexane, n-hexane solution (1.05M, 41.1ml) ) Was added. After completion of the dropwise addition, the temperature was raised to 70°C and stirred for 3 hours, and then the low boiling point component was distilled off under reduced pressure. It cooled to -50 degreeC, boron tribromide (12.4 g) was added, and it heated up to room temperature and stirred for 0.5 hours. Then, it cooled again with an ice bath, and N,N-diisopropylethylamine (10.6 g) was added. After stirring at room temperature until heat generation subsided, it heated up to 120 degreeC, and heated and stirred for 4 hours, aluminum chloride (12.1 g) was further added, and it heated and stirred for 2 hours. The reaction solution was cooled to room temperature, an aqueous sodium acetate solution cooled with an ice bath, followed by addition of ethyl acetate, followed by stirring for 1 hour to precipitate a precipitate, and after adding heptane further, the precipitate was filtered. Subsequently, the precipitate was purified by a silica gel short column (eluent: toluene), further dissolved in toluene, reprecipitated with heptane, and finally sublimated and purified to obtain compound (1-101) (16.0 g).

The structure of the compound obtained from NMR measurement was confirmed.

¹ H NMR (δppm in CDCl ₃ ): 2.4(s,6H), 7.3~7.4(m,10H), 7.4(m,2H), 7.5(m,2H), 7.5(s,2H), 7.6(d ,2H), 7.7(d,2H), 8.2(d,2H), 8.8(d,2H).

Synthesis Example (2): Synthesis of Compound (1-201)

1,3-dibromo-5-fluorobenzene (80.0 g), 4-(9H-carbazol-9-yl) phenylboronic acid (130.9 g), dichlorobis ((di-t-butyl) as a palladium catalyst (4-dimethylaminophenyl) phosphino) palladium (Pd-132, 1.47 g), potassium phosphate (176 g), toluene (600 mL), isopropyl alcohol (IPA, 150 mL) and water (70 mL) were added to a flask in a nitrogen atmosphere. After the reaction mixture was cooled, water was added and stirred, and toluene was added to separate and extract the water layer to remove the water layer, and then the organic layer was washed with water, and the organic layer was concentrated under reduced pressure to obtain a crude product. Further, the compound (C) was obtained by washing with a mixed solution of heptane/ethyl acetate = 4/1 (volume ratio) (166 g).

Compound (C) (25.0 g), 3-(2-methylphenyl) phenol (28.5 g), potassium carbonate (39.0 g) and NMP (150 mL) were put into a flask under a nitrogen atmosphere, and stirred at 200° C. for 2 hours, Further, potassium phosphate (37 g) was added, followed by stirring at 200°C for 4 hours. After cooling the reaction solution, NMP was distilled off under reduced pressure, toluene and water were added and stirred, and then the water layer was removed. Further, after washing the organic layer with water twice, the organic layer was concentrated under reduced pressure. The obtained crude was purified by a silica gel column (eluent: toluene/heptane = 3/7 (volume ratio), then changed to 4/6 (volume ratio)) to obtain compound (D) (40 g).

To a flask containing compound (D) (39.0 g) and xylene (190 ml), s-butyllithium/cyclohexane and n-hexane solution (1.05M, 57.0 ml) were added while cooling with an ice bath under a nitrogen atmosphere. After completion of the dropwise addition, the temperature was raised to 70°C and stirred for 3 hours, and then the low boiling point component was distilled off under reduced pressure. It cooled to -50 degreeC, boron tribromide (17.1 g) was added, and it heated up to room temperature and stirred for 0.5 hours. Then, it cooled again with an ice bath, and N,N-diisopropylethylamine (14.7 g) was added. After stirring at room temperature until heat generation subsided, it heated up to 130 degreeC and stirred for 4 hours after stirring. The reaction solution was cooled to room temperature, an aqueous sodium acetate solution cooled with an ice bath, followed by addition of ethyl acetate, followed by stirring for 1 hour to precipitate a precipitate, and after adding heptane further, the precipitate was filtered. The precipitate was washed with methanol, water, ethyl acetate, and heptane in that order, and then the solid was dried, further suspended in ethyl acetate, washed by refluxing, further dissolved in hot chlorobenzene, concentrated and reprecipitated, and finally The compound (1-201) was obtained by sublimation purification (27.0 g).

The structure of the compound obtained from NMR measurement was confirmed.

¹ H NMR (δppm in CDCl ₃ ): 2.4(s,6H), 7.3~7.4(m,8H), 7.4(m,4H), 7.4~7.5(m,2H), 7.5(d,2H), 7.6 (d,2H), 7.6(s,2H), 7.7(d,2H), 8.0(d,2H), 8.2(d,2H), 8.8(d,2H).

By appropriately changing the compound of the raw material, another polycyclic aromatic compound of the present invention can be synthesized by a method according to the synthesis example described above.

Next, in order to explain the present invention in more detail, examples of the organic EL device using the compound of the present invention are shown, but the present invention is not limited thereto.

<Evaluation of organic EL device>

The organic EL devices according to Examples 1 to 2 and Comparative Examples 1 to 2 were fabricated, voltage (V) and external quantum efficiency (%), which are characteristics at the time of ^{1000 cd/m 2 light emission, were measured, and then 10 mA/cm 2} The time to maintain the luminance of 90% or more of the initial luminance at the time of constant current driving at the current density was measured.

Quantum efficiency of a light emitting device includes internal quantum efficiency and external quantum efficiency. The internal quantum efficiency represents a ratio at which external energy injected as electrons (or holes) into the light emitting layer of the light emitting device is purely converted into photons. On the other hand, the external quantum efficiency is calculated based on the amount of this photon emitted to the outside of the light-emitting element, and the photons generated in the light-emitting layer are partially absorbed inside the light-emitting element or are continuously reflected. Since it is not emitted to the outside, the external quantum efficiency becomes lower than the internal quantum efficiency.

The method of measuring the external quantum efficiency is as follows. Using the voltage/current generator R6144 manufactured by Advantest, the device was made to emit light by applying a voltage such that ^{the luminance of the device is 1000 cd/m 2.} Using a spectroscopic radiation luminance meter SR-3AR manufactured by TOPCON, the spectral radiation luminance in the visible region was measured from the direction perpendicular to the light-emitting surface. Assuming that the light-emitting surface is a fully diffused surface, a value obtained by dividing the measured value of the spectral radiation luminance of each wavelength component by the wavelength energy and multiplied by π is the number of photons at each wavelength. Subsequently, the number of photons was accumulated over the entire observed wavelength range to obtain the total number of photons emitted from the device. The value obtained by dividing the applied current value by the small charge is the number of carriers injected into the device, and the number obtained by dividing the total number of photons emitted from the device by the number of carriers injected into the device is the external quantum efficiency.

Table 1 shows the material configuration and EL characteristic data of each layer in the organic EL devices according to the fabricated Examples 1 to 2 and Comparative Examples 1 to 2.

In the above Table 1, the "HI" is N ^4, N ^{4 '-} diphenyl -N ^4, N ^4' - bis (9-phenyl -9H- carbazole-3-yl) [1,1'- Phenyl]-4,4'-diamine, "IL" is 1,4,5,8,9,12-hexaazatriphenylenehexacarbonitrile, "HT-1" is N-([1,1 '-Biphenyl]-4-yl)-9,9-dimethyl-N-(4-(9-phenyl-9H-carbazol-3-yl)phenyl)-9H-fluoren-2-amine, and "HT-2" is N,N-bis(4-(dibenzo[b,d]furan-4-yl)phenyl)-[1,1':4',1"-terphenyl]-4-amine, , "BH-1" is 2-(10-phenylanthracene-9-yl)naphtho[2,3-b]benzofuran, "BD-1" is 2,12-di-t-butyl-5, 9-bis(4-(t-butyl)phenyl)-7-methyl-5,9-dihydro-5,9-diaza-13b-boranaphtho[3,2,1-de]anthracene, comparison Compound (1) is 9-(5,9-dioxa-13b-boranaphtho[3,2,1-de]anthracene-7-yl)-9H-carbazole, and comparative compound (2) is 9- It is (4-(5,9-dioxa-13b-boranaphtho[3,2,1-de]anthracen-7-yl)phenyl)-9H-carbazole The chemical structure below together with "Liq" is shown below. Show.

<Example 1>

<Device in which the electron transport material is compound (1-101)>

A 26 mm x 28 mm x 0.7 mm glass substrate (manufactured by Optoscience Co., Ltd.) was used as a transparent supporting substrate by polishing ITO formed by sputtering to a thickness of 180 nm to 150 nm. This transparent support substrate was fixed to a substrate holder of a commercial vapor deposition apparatus (manufactured by Choshu Sangyo Co., Ltd.), and HI, IL, HT-1, HT-2, BH-1, BD-1 and compound (1-101) The tantalum evaporation boat containing each of and the aluminum nitride evaporation boat containing Liq, Mg, and Ag respectively were mounted.

Each of the following layers was sequentially formed on the ITO film of the transparent support substrate. The vacuum bath was decompressed to 5×10 ^-4 Pa, first, HI was heated to evaporate to a film thickness of 40 nm, and then, IL was heated to evaporate to a film thickness of 5 nm, and then, HT-1 Was heated to evaporate to have a film thickness of 15 nm, and then, HT-2 was heated to evaporate to have a film thickness of 10 nm to form a four-layer hole layer. Next, BH-1 and BD-1 were simultaneously heated and vapor-deposited so that the film thickness became 25 nm to form a light emitting layer. The deposition rate was adjusted so that the weight ratio of BH-1 and BD-1 was approximately 98 to 2. Further, compound (1-101) and Liq were simultaneously heated and deposited to a film thickness of 5 nm to form an electron transport layer. The deposition rate was adjusted so that the weight ratio of compound (1-101) and Liq was approximately 50 to 50. The deposition rate of each layer was 0.01 to 1 nm/sec. Thereafter, Liq is heated to evaporate at a deposition rate of 0.01 to 0.1 nm/sec so that the film thickness becomes 1 nm, and then, magnesium and silver are simultaneously heated to evaporate to a film thickness of 100 nm, and a cathode is formed to form an organic EL element. Got it. At this time, the deposition rate was adjusted between 0.1 nm and 10 nm/sec so that the atomic ratio of magnesium and silver was 10 to 1.

A direct current voltage was applied using an ITO electrode as an anode and a magnesium/silver electrode as a cathode, and the characteristics at the time of 1000 cd/m 2 light emission were measured. As a result, blue light emission was obtained. In addition, the driving voltage was 4.1V, the external quantum efficiency was 6.1%, and the device life was 362 hours.

<Example 2>

<Device in which the electron transport material is compound (1-201)>

An organic EL device was obtained in the same manner as in Example 1 except that the material of the electron transport layer was changed to compound (1-201). Blue light emission was obtained as a result of measuring the characteristics at the time of 1000 cd/m 2 light emission. In addition, the driving voltage was 3.5V, the external quantum efficiency was 6.3%, and the device life was 332 hours.

<Comparative Example 1>

<Device in which the electron transport material is comparative compound (1)>

An organic EL device was obtained in the same manner as in Example 1 except that the material of the electron transport layer was changed to the comparative compound (1). Blue light emission was obtained as a result of measuring the characteristics at the time of 1000 cd/m 2 light emission. In addition, the driving voltage was 3.7V, the external quantum efficiency was 5.7%, and the device life was 85 hours.

<Comparative Example 2>

<Device in which the electron transport material is comparative compound (2)>

An organic EL device was obtained in the same manner as in Example 1 except that the material of the electron transport layer was changed to the comparative compound (2). Blue light emission was obtained as a result of measuring the characteristics at the time of 1000 cd/m 2 light emission. In addition, the driving voltage was 3.4V, the external quantum efficiency was 5.8%, and the device life was 93 hours.

[Industrial availability]

According to a preferred embodiment of the present invention, an organic EL device having excellent luminous efficiency and device life, particularly excellent device life, is obtained by manufacturing an organic EL device using an electron transport material containing a polycyclic aromatic compound represented by the general formula (1). Can provide.

100: organic electroluminescent device
101: substrate
102: anode
103: hole injection layer
104: hole transport layer
105: light emitting layer
106: electron transport layer
107: electron injection layer
108: cathode

Claims (16)

An electron transport material or electron injection material comprising a polycyclic aromatic compound represented by the following general formula (1) or a multimer of a polycyclic aromatic compound having a plurality of structures represented by the following general formula (1).

(In the above formula (1),
A ring, B ring, and C ring are each independently an aryl ring or a heteroaryl ring, and at least one hydrogen in these rings may be substituted,
Y ¹ is B, P, P=O, P=S, Al, Ga, As, Si-R or Ge-R, and R of Si-R and Ge-R is aryl, alkyl or cycloalkyl,
X ¹ and X ² are each independently >O, >NR, >C(-R) ₂ , >S or >Se, and R in >NR is an optionally substituted aryl, optionally substituted heteroaryl, or substituted Alkyl which may be substituted or cycloalkyl which may be substituted _{, R of >C(-R) 2} is hydrogen, aryl which may be substituted, alkyl which may be substituted, or cycloalkyl which may be substituted, and R of >NR and/or R of >C(-R) ₂ may be bonded to at least one of the A ring, B ring and C ring by a linking group or a single bond,
At least one hydrogen in the compound or structure represented by formula (1) may be substituted with deuterium, cyano, or halogen, and,
At least one hydrogen in the compound or structure represented by formula (1) is substituted with a group represented by the general formula (oR),
In the formula (oR), R ²¹ is alkyl, R ²² to R ²⁵ are each independently hydrogen, aryl, heteroaryl, alkyl or cycloalkyl, and ^{adjacent groups in R 22} to R ²⁵ are bonded to each other to form a benzene ring and Together, an aryl ring or heteroaryl ring may be formed, at least one hydrogen in the formed ring may be substituted with aryl, heteroaryl, alkyl or cycloalkyl, and the group represented by the formula (oR) is * It is substituted with at least one hydrogen in the compound or structure represented by the above formula (1).) The method according to claim 1, wherein in the formula (1),
Ring A, Ring B, and Ring C are each independently an aryl ring or a heteroaryl ring, and at least one hydrogen in these rings is 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 through a single bond or a linking group), substituted Or may be substituted with unsubstituted alkyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted alkoxy, or substituted or unsubstituted aryloxy, and these rings are composed of ^{Y 1} , X ¹ and X ² It has a 5-membered ring or a 6-membered ring that shares a bond with the condensed bicyclic structure of the above formula,
Y ¹ is B, P, P=O, P=S, Al, Ga, As, Si-R or Ge-R, and R of Si-R and Ge-R is aryl, alkyl or cycloalkyl,
X ¹ and X ² are each independently >O, >NR, >C(-R) ₂ , >S, or >Se, and R of >NR is an aryl, alkyl or cyclo optionally substituted with alkyl or cycloalkyl. Heteroaryl, alkyl or cycloalkyl which may be substituted with alkyl, and _{R of >C(-R) 2} is an aryl, alkyl or cycloalkyl which may be substituted with hydrogen, alkyl or cycloalkyl, and the> R of NR and/or R of >C(-R) ₂ is -O-, -S-, -C(-R) ₂ -or at least one of ring A, ring B, and ring C by a single bond May be bonded to a dog, and _{R of -C(-R) 2} -is hydrogen, alkyl or cycloalkyl,
At least one hydrogen in the compound or structure represented by formula (1) may be substituted with deuterium, cyano, or halogen,
In the case of a multimer, it is a 2 or trimer having 2 or 3 structures represented by general formula (1), and,
At least one hydrogen in the compound or structure represented by formula (1) is substituted with a group represented by the general formula (oR),
In the formula (oR), R ²¹ is an alkyl having 1 to 24 carbon atoms, and R ²² to R ²⁵ are each independently hydrogen, aryl having 6 to 30 carbon atoms, heteroaryl having 2 to 30 carbon atoms, alkyl having 1 to 24 carbon atoms Or a cycloalkyl having 3 to 24 carbon atoms, and ^{adjacent groups among R 22} to R ²⁵ may be bonded to each other to form an aryl ring having 9 to 16 carbon atoms or a heteroaryl ring having 6 to 15 carbon atoms together with a benzene ring. At least one hydrogen in may be substituted with a C6-C30 aryl, a C2-C30 heteroaryl, a C1-C24 alkyl, or a C3-C24 cycloalkyl, by the above formula (oR). An electron transport material or an electron injection material characterized in that the group represented by * is substituted with at least one hydrogen in the compound or structure represented by the formula (1). The electron transport material or electron injection material according to claim 1, wherein the polycyclic aromatic compound is represented by the following general formula (2).

(In the above formula (2),
R ¹ to R ¹¹ are each independently hydrogen, aryl, heteroaryl, diarylamino, diheteroarylamino, arylheteroarylamino, diarylboryl (two aryls may be bonded through a single bond or a linking group), Alkyl, cycloalkyl, alkoxy or aryloxy, and at least one hydrogen in these may be substituted with aryl, heteroaryl, alkyl or cycloalkyl, and ^{adjacent groups among R 1} to R ¹¹ are bonded to each other. An aryl ring or heteroaryl ring may be formed together with the a ring, b ring or c ring, and at least one hydrogen in the formed ring is aryl, heteroaryl, diarylamino, diheteroarylamino, arylheteroarylamino, Diarylboryl (two aryls may be bonded through a single bond or a linking group), alkyl, cycloalkyl, alkoxy or aryloxy may be substituted, and at least one hydrogen in these may be aryl, heteroaryl, alkyl Or it may be substituted with cycloalkyl,
Y ¹ is B, P, P=O, P=S, Al, Ga, As, Si-R or Ge-R, wherein R of Si-R and Ge-R is an aryl having 6 to 12 carbon atoms, 1 carbon number ~6 alkyl or C3-C14 cycloalkyl,
X ¹ and X ² are each independently >O, >NR, >C(-R) ₂ , >S or >Se, wherein R of >NR is a C6-C12 aryl, a C2-C15 heteroaryl , C1-C6 alkyl or C3-C14 cycloalkyl, wherein _{R of >C(-R) 2} is hydrogen, C6-C12 aryl, C1-C6 alkyl or C3-C14 cyclo Alkyl, and R of >NR and/or R of >C(-R) ₂ are -O-, -S-, -C(-R) ₂ -or by a single bond, the ring a, b May be bonded to at least one of a ring and a c ring, and _{R of -C(-R) 2} -is an alkyl having 1 to 6 carbon atoms or a cycloalkyl having 3 to 14 carbon atoms,
At least one hydrogen in the compound represented by formula (2) may be substituted with deuterium, cyano or halogen, and,
The group represented by the general formula (oR) is bonded to at least one of the a ring, b ring, c ring, and the aryl ring and heteroaryl ring formed together with these rings in *,
In the above formula (oR), R ²¹ is alkyl having 1 to 12 carbon atoms, and R ²² to R ²⁵ are each independently hydrogen, aryl having 6 to 16 carbon atoms, heteroaryl having 2 to 20 carbon atoms, alkyl having 1 to 12 carbon atoms Or a cycloalkyl having 3 to 16 carbon atoms, and ^{adjacent groups among R 22} to R ²⁵ may be bonded to form a naphthalene ring, a phenanthrene ring, a fluorene ring or a carbazole ring together with a benzene ring, and in the formed ring At least one hydrogen of may be substituted with a C6-C16 aryl, a C2-C20 heteroaryl, a C1-C12 alkyl, or a C3-C16 cycloalkyl.) The method according to claim 3, wherein in formula (2),
R ¹ to R ¹¹ are each independently hydrogen, aryl having 6 to 30 carbon atoms (this aryl may be substituted with heteroaryl having 2 to 15 carbon atoms), heteroaryl having 2 to 30 carbon atoms, diarylamino (however, aryl Is aryl having 6 to 12 carbon atoms), diaryl boryl (however, aryl is an aryl having 6 to 12 carbon atoms, and two aryls may be bonded through a single bond or a linking group), alkyl having 1 to 24 carbon atoms, or 3 carbon atoms It is a cycloalkyl of ~24, and ^{adjacent groups among R 1} ~ R ¹¹ are bonded to form an aryl ring having 9 to 16 carbon atoms or a heteroaryl ring having 6 to 15 carbon atoms together with the a ring, b ring or c ring, May be present, and at least one hydrogen in the formed ring is aryl having 6 to 30 carbon atoms (this aryl may be substituted with heteroaryl having 2 to 15 carbon atoms), heteroaryl having 2 to 30 carbon atoms, diarylamino ( However, aryl is an aryl having 6 to 12 carbon atoms), diaryl boryl (however, aryl is an aryl having 6 to 12 carbon atoms, and two aryls may be bonded through a single bond or a linking group), alkyl having 1 to 24 carbon atoms Or it may be substituted with a C3-C24 cycloalkyl,
Y ¹ is B, P, P=O, P=S or Si-R, and R of Si-R is a C6-C10 aryl, C1-C4 alkyl, or C5-C10 cycloalkyl,
X ¹ and X ² are each independently >O, >NR, >C(-R) ₂ or >S, and R of >NR is an aryl having 6 to 10 carbon atoms, alkyl having 1 to 4 carbon atoms, or 5 to carbon atoms 10 cycloalkyl, wherein R of >C(-R) ₂ is hydrogen, aryl having 6 to 10 carbon atoms, alkyl having 1 to 4 carbon atoms, or cycloalkyl having 5 to 10 carbon atoms,
At least one hydrogen in the compound represented by formula (2) may be substituted with deuterium, cyano or halogen, and,
The group represented by the general formula (oR) is bonded to at least one of the a ring, b ring, c ring, and the aryl ring and heteroaryl ring formed together with these rings in *,
In the above formula (oR), R ²¹ is an alkyl having 1 to 6 carbon atoms, and R ²² to R ²⁵ are each independently hydrogen, aryl having 6 to 12 carbon atoms, heteroaryl having 2 to 15 carbon atoms, alkyl having 1 to 6 carbon atoms Or a cycloalkyl having 3 to 14 carbon atoms, and ^{adjacent groups among R 22} to R ²⁵ may be bonded to form a naphthalene ring, a phenanthrene ring, a fluorene ring or a carbazole ring together with a benzene ring, and in the formed ring At least one hydrogen of may be substituted with a C6-C12 aryl, a C2-C15 heteroaryl, a C1-C6 alkyl, or a C3-C14 cycloalkyl. material. The method according to claim 3, wherein in formula (2),
R ¹ to R ¹¹ are each independently hydrogen, aryl having 6 to 16 carbon atoms (the aryl may be substituted with heteroaryl having 2 to 10 carbon atoms), heteroaryl having 2 to 20 carbon atoms, diarylamino (however, aryl Is aryl having 6 to 10 carbon atoms), diaryl boryl (however, aryl is an aryl having 6 to 10 carbon atoms, and two aryls may be bonded through a single bond or a linking group), alkyl having 1 to 12 carbon atoms, or 3 carbon atoms Is a cycloalkyl of ~16,
Y ¹ is B, P, P=O or P=S,
X ¹ and X ² are each independently >O, >NR, or >C(-R) ₂ , wherein R of >NR is a C6-C10 aryl, a C1-C4 alkyl, or a C5-C10 cyclo Alkyl, and R of >C(-R) ₂ is hydrogen, aryl having 6 to 10 carbon atoms, alkyl having 1 to 4 carbon atoms, or cycloalkyl having 5 to 10 carbon atoms, and,
The group represented by the general formula (oR) is bonded to at least one of the a ring, b ring, and c ring in *,
In the formula (oR), R ²¹ is alkyl having 1 to 4 carbon atoms, and R ²² to R ²⁵ are each independently hydrogen, aryl having 6 to 10 carbon atoms, alkyl having 1 to 4 carbon atoms, or cycloalkyl having 5 to 10 carbon atoms Electron transport material or electron injection material, characterized in that. The method according to claim 3, wherein in formula (2),
R ¹ to R ¹¹ are each independently hydrogen, aryl having 6 to 16 carbon atoms (the aryl may be substituted with heteroaryl having 2 to 10 carbon atoms), heteroaryl having 2 to 20 carbon atoms, diarylamino (however, aryl Is aryl having 6 to 10 carbon atoms), diaryl boryl (however, aryl is an aryl having 6 to 10 carbon atoms, and two aryls may be bonded through a single bond or a linking group), alkyl having 1 to 12 carbon atoms, or 3 carbon atoms Is a cycloalkyl of ~16,
Y ¹ is B,
X ¹ and X ² are each independently >O or >NR, wherein R of >NR is a C6-C10 aryl, a C1-C4 alkyl, or a C5-C10 cycloalkyl, and,
The group represented by the general formula (oR) is bonded to at least one of the a ring, b ring, and c ring in *,
In the formula (oR), R ²¹ is alkyl having 1 to 4 carbon atoms, and R ²² to R ²⁵ are each independently hydrogen, aryl having 6 to 10 carbon atoms, alkyl having 1 to 4 carbon atoms, or cycloalkyl having 5 to 10 carbon atoms Electron transport material or electron injection material, characterized in that. The method according to claim 3, wherein in formula (2),
R ¹ to R ¹¹ are each independently hydrogen, aryl having 6 to 16 carbon atoms (the aryl may be substituted with heteroaryl having 2 to 10 carbon atoms), heteroaryl having 2 to 20 carbon atoms, diarylamino (however, aryl Is aryl having 6 to 10 carbon atoms), diaryl boryl (however, aryl is an aryl having 6 to 10 carbon atoms, and two aryls may be bonded through a single bond or a linking group), alkyl having 1 to 12 carbon atoms, or 3 carbon atoms Is a cycloalkyl of ~16,
Y ¹ is B or P=O,
X ¹ and X ² are >O, and,
The group represented by the general formula (oR) is bonded to at least one of the a ring, b ring, and c ring in *,
In the formula (oR), R ²¹ is alkyl having 1 to 4 carbon atoms, and R ²² to R ²⁵ are each independently hydrogen, aryl having 6 to 10 carbon atoms, alkyl having 1 to 4 carbon atoms, or cycloalkyl having 5 to 10 carbon atoms Electron transport material or electron injection material, characterized in that. The method according to claim 3, wherein in formula (2),
R ¹ to R ¹¹ are each independently hydrogen, aryl having 6 to 16 carbon atoms (the aryl may be substituted with heteroaryl having 2 to 10 carbon atoms), heteroaryl having 2 to 20 carbon atoms, diarylamino (however, aryl Is aryl having 6 to 10 carbon atoms), diaryl boryl (however, aryl is an aryl having 6 to 10 carbon atoms, and two aryls may be bonded through a single bond or a linking group), alkyl having 1 to 12 carbon atoms, or 3 carbon atoms Is a cycloalkyl of ~16,
Y ¹ is B,
X ¹ and X ² are >O, and,
The group represented by the general formula (oR) is bonded to at least one of the a ring, b ring, and c ring in *,
In the formula (oR), R ²¹ is alkyl having 1 to 4 carbon atoms, and R ²² to R ²⁵ are each independently hydrogen, aryl having 6 to 10 carbon atoms, alkyl having 1 to 4 carbon atoms, or cycloalkyl having 5 to 10 carbon atoms Electron transport material or electron injection material, characterized in that. The method according to any one of claims 3 to 8, wherein in the formula (2),
Diphenylamino group, carbazolyl group, or benzocarbazolyl group, which may be substituted with alkyl having 1 to 4 carbon atoms or cycloalkyl having 5 to 10 carbon atoms, in at least one of the a ring, b ring and c ring And these groups may be substituted with at least one of the a ring, b ring and c ring through a phenylene group, and
An electron transport material or electron injection material, wherein a group represented by the general formula (oR) is bonded to at least one of the a ring, b ring, and c ring in *. The method according to any one of claims 3 to 8, wherein in the formula (2),
The a ring is substituted with a diphenylamino group, a carbazolyl group or a benzocarbazolyl group, which may be substituted with a C1-C4 alkyl or a C5-C10 cycloalkyl, and these groups are substituted with a phenylene group. May be substituted for, and,
An electron transport material or an electron injection material, wherein a group represented by the general formula (oR) is bonded to the ring b and ring c in *. The electron transport material or electron injection material according to any one of claims 1 to 10, wherein in the formula (1) or (2), the halogen is fluorine. The electron transport material or electron injection material according to claim 1, wherein the polycyclic aromatic compound is represented by the following structural formula.

("Me" in each formula is methyl.) A pair of electrodes consisting of an anode and a cathode, a light emitting layer disposed between the pair of electrodes, and an electron transport material according to any one of claims 1 to 12 disposed between the cathode and the light emitting layer. Or an electron transport layer and/or an electron injection layer containing an electron injection material. The method of claim 13, wherein at least one of the electron transport layer and the electron injection layer is a borane derivative, a pyridine derivative, a fluoranthene derivative, a BO derivative, an anthracene derivative, a benzofluorene derivative, a phosphine oxide derivative, a pyrimidine derivative. , Carbazole derivatives, triazine derivatives, benzoimidazole derivatives, phenanthroline derivatives, and quinolinol-based metal complexes. An organic electroluminescent device comprising at least one selected from the group consisting of. The method according to claim 14, wherein the electron transport layer and/or the electron injection layer are alkali metals, alkaline earth metals, rare earth metals, oxides of alkali metals, halides of alkali metals, oxides of alkaline earth metals, and halides of alkaline earth metals. , Rare earth metal oxides, rare earth metal halides, alkali metal organic complexes, alkaline earth metal organic complexes, and organic electroluminescence characterized in that it further contains at least one selected from the group consisting of rare earth metal organic complexes device. A display device or lighting device comprising the organic electroluminescent element according to any one of claims 13 to 15.

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