KR20240003718A - Polycyclic aromatic compound - Google Patents

Abstract

Provided is a novel compound useful as a material for organic devices, such as organic electroluminescent devices. The present invention provides a polycyclic aromatic compound represented by the formula (1) or the formula (2), wherein an A ring, B ring, C ring, D ring, E ring, and F ring are substituted or unsubstituted aryl rings or substituted or unsubstituted heteroaryl rings, and at least one hydrogen in the structure represented by the formula (1) or the formula (2) may be substituted with deuterium.

Description

Polycyclic aromatic compound {POLYCYCLIC AROMATIC COMPOUND}

The present invention relates to polycyclic aromatic compounds. The present invention also relates to organic devices using the polycyclic aromatic compound, such as organic electroluminescent elements, organic field effect transistors, and organic thin-film solar cells, and display devices and lighting devices.

Conventionally, display devices using light-emitting elements that emit electroluminescence have been studied in various ways because they enable lower power consumption and reduction in thickness. Additionally, organic electroluminescent elements made of organic materials have been actively studied because they can easily be made lighter or larger. In particular, regarding the development of organic materials with luminescent properties such as blue and green, which are one of the three primary colors of light, and the development of organic materials with charge transport capabilities such as holes and electrons (with the potential to become semiconductors or superconductors), Both high-molecular and low-molecular compounds have been actively studied so far.

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

As a light-emitting material for the light-emitting layer, for example, a material obtained by improving an azaborine derivative has been reported (Patent Document 1). Additionally, various compounds are being developed as electron transport materials (for example, patent document 2).

Patent Document 1: International Publication No. 2015/102118 Patent Document 2: International Publication No. 2021/079915

As described above, various materials have been developed as materials for use in organic EL devices. However, in order to increase the selection of materials for organic EL devices, the development of materials made of compounds different from those of the past is expected. In particular, there is a demand for materials that can further improve the performance of organic devices such as organic EL elements and materials that improve the manufacturing process.

The object of the present invention is to provide novel compounds useful as materials for organic devices such as organic EL elements.

The present inventors conducted intensive studies to solve the above problems and found that polycyclic aromatic compounds having a novel skeleton containing boron have advantageous properties as materials for organic devices. Then, further studies were conducted based on this knowledge, and the present invention was completed. That is, the present invention provides the following polycyclic aromatic compounds, and materials for organic devices containing the following polycyclic aromatic compounds.

<1> Polycyclic aromatic compound represented by formula (1) or formula (2);

In equations (1) and (2),

Ring A, ring B, ring C, ring D, ring E, and ring F are each independently a substituted or unsubstituted aryl ring or a substituted or unsubstituted heteroaryl ring,

Ring A and E may be further bonded through a single bond or linking group, Ring B and F may be further bonded through a single bond or linking group, and Ring C and D may be further bonded through a single bond or linking group,

At least one hydrogen in the structure represented by formula (1) or formula (2) may be substituted with deuterium.

<2> Polycyclic aromatic compound according to <1>, represented by formula (1X) or formula (2X);

In formula (1X) and formula (2X),

Z is each independently -C(-R ^Z )= or -N=,

R ^Z is each independently hydrogen or a substituent,

Two adjacent ^R

Z=Z may each independently be >NR ^NZ , >O, >C(-R ^CZ ) ₂ , >Si(-R ^IZ ) ₂ , >S, or >Se, and R ^NZ , R ^CZ and R ^IZ are Each is independently hydrogen, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted alkyl, or substituted or unsubstituted cycloalkyl, and two R ^CZ may be bonded to each other to form a ring. Alternatively, two R ^IZ may be combined with each other to form a ring,

The a ring and the e ring may be further bonded through a single bond or linking group, the b ring and f ring may be further bonded through a single bond or linking group, the c ring and the d ring may be further bonded through a single bond or linking group,

At least one hydrogen in the structure represented by formula (1X) or (2X) may be substituted with deuterium.

<3> The polycyclic aromatic compound according to <2>, in which all Zs are each independently -C(-R ^Z )=.

<4> The polycyclic aromatic compound according to <3>, which is represented by any of the following formulas.

<5> A material for an organic device containing the polycyclic aromatic compound according to any one of <1> to <4>.

<6> The organic device material according to <5>, wherein the organic device material is a material for an organic electroluminescent element, a material for an organic field effect transistor, a material for an organic thin film solar cell, or a material for a wavelength conversion filter.

<7> Organic electroluminescence, which has a pair of electrodes consisting of an anode and a cathode and an organic layer disposed between the pair of electrodes, wherein the organic layer contains the polyaromatic compound according to any one of <1> to <4>. device.

<8> The organic electroluminescent device according to <7>, wherein the organic layer is an electron transport layer.

<9> A display or lighting device including the organic electroluminescent element according to <7> or <8>.

<10> Compounds represented by the following formula (SM);

During the ceremony (SM),

Ring A, ring B, ring C, ring D, ring E, and ring F are each independently a substituted or unsubstituted aryl ring or a substituted or unsubstituted heteroaryl ring,

Ring A and E may be further bonded through a single bond or linking group, Ring B and F may be further bonded through a single bond or linking group, and Ring C and D may be further bonded through a single bond or linking group,

At least one hydrogen in the structure represented by formula (SM) may be substituted with deuterium.

<11> The compound described in <10>, represented by the formula (SM-X);

In formula (SM-X),

Z is each independently -C(-R ^Z )= or -N=,

R ^Z is each independently hydrogen or a substituent,

Two adjacent ^R

Z=Z may each independently be >NR ^NZ , >O, >C(-R ^CZ ) ₂ , >Si(-R ^IZ ) ₂ , >S, or >Se, and R ^NZ , R ^CZ and R ^IZ are Each is independently hydrogen, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted alkyl, or substituted or unsubstituted cycloalkyl, and two R ^CZ may be bonded to each other to form a ring. Two R ^IZ may be combined with each other to form a ring,

The a ring and the e ring may be further bonded through a single bond or linking group, the b ring and f ring may be further bonded through a single bond or linking group, and the c ring and d ring may be further bonded through a single bond or linking group,

At least one hydrogen in the structure represented by formula (SM-X) may be substituted with deuterium.

<12> The compound according to <11>, in which all Zs are each independently -C(-R ^Z )=.

<13> The compound described in <12>, represented by the following formula.

<14> The method for producing a polycyclic aromatic compound according to <1>, comprising reacting a compound represented by the following formula (SM) with a boronating agent in the presence of a Bronsted base;

During the ceremony (SM),

Ring A, ring B, ring C, ring D, ring E, and ring F are each independently a substituted or unsubstituted aryl ring or a substituted or unsubstituted heteroaryl ring,

Ring A and E may be further bonded through a single bond or linking group, Ring B and F may be further bonded through a single bond or linking group, and Ring C and D may be further bonded through a single bond or linking group,

At least one hydrogen in the structure represented by formula (SM) may be substituted with deuterium.

According to the present invention, a novel polycyclic aromatic compound useful as a material for organic devices such as organic electroluminescent elements is provided. The polycyclic aromatic compound of the present invention can be used in the production of organic devices such as organic electroluminescent elements.

1 is a schematic cross-sectional view showing an example of an organic electroluminescent device.

Below, the present invention is explained in detail. The description of the structural requirements described below may be based on representative embodiments or specific examples, but the present invention is not limited to such embodiments. In addition, in this specification, the numerical range indicated using “~” means a range that includes the numerical values written before and after “~” as the lower limit and upper limit. In addition, in this specification, “hydrogen” in the description of the structural formula means “hydrogen atom (H).” Similarly, “carbon atom (C)” is sometimes referred to as “carbon.”

In this specification, “adjacent groups” means two groups each bonded to two adjacent atoms (two atoms directly bonded by a covalent bond) in the structural formula.

In this specification, “Me” is methyl, “Et” is ethyl, “nBu” is n-butyl (n-butyl), “tBu” is t-butyl (tertiary butyl), “iBu” is isobutyl, and “secBu” is " is secondaryributyl, "nPr" is n-propyl (normal propyl), "iPr" is isopropyl, "tAm" is t-amyl, "2EH" is 2-ethylhexyl, "tOct" is t-octyl, " “Ph” is phenyl, “Mes” is mesityl (2,4,6-trimethylphenyl), “Ad” is 1-adamantyl, “Tf” is trifluoromethanesulfonyl, “TMS” is trimethylsilyl, “D” represents deuterium.

In this specification, the organic electroluminescent device is sometimes referred to as an organic EL device.

In this specification, the chemical structure or substituent is expressed in terms of carbon number, but in the case where the chemical structure is substituted by a substituent or when the substituent is further substituted by a substituent, the number of carbon atoms refers to the number of carbon atoms in the chemical structure or each substituent, It does not mean the total carbon number of the chemical structure and substituents, or the total carbon number of substituents and substituents. For example, “substituent B of carbon number Y substituted by substituent A of carbon number X” means that “substituent A of carbon number It is not the total number of carbons in B. Also, for example, “substituent B of carbon number Y substituted by substituent A” means that “substituent B of carbon number Y” is substituted by “substituent A (with no limitation on carbon number)”, and carbon number Y is substituent A and It is not the total carbon number of substituent B.

<Description of rings and substituents>

First, details of the rings and substituents used in this specification will be described below.

The “aryl ring” in this specification includes, for example, an aryl ring having 6 to 30 carbon atoms, preferably an aryl ring with 6 to 16 carbon atoms, more preferably an aryl ring with 6 to 12 carbon atoms, and 6 carbon atoms. An aryl ring of ~10 is particularly preferred.

Specific examples of “aryl rings” include monocyclic benzene rings, bicyclic biphenyl rings, condensed bicyclic naphthalene rings, indene rings, and tricyclic terphenyl rings (m-terphenyl, o-terphenyl, p-terphenyl). ), acenaphthylene ring, fluorene ring, phenalene ring, phenanthrene ring, anthracene ring, condensed 3-ring system, triphenylene ring, pyrene ring, naphthacene ring, chrysene ring, fused 5-ring system, perylene ring, Pentacene pills, etc. can be mentioned. Additionally, the fluorene ring, benzofluorene ring, and indene ring also include structures in which a fluorene ring, a benzofluorene ring, and a cyclopentane ring are spiro-bonded, respectively. In addition, in the fluorene ring, benzofluorene ring, and indene ring, two of the two hydrogens of methylene in the structure are each substituted with an alkyl such as methyl as the first substituent described later, resulting in dimethylfluorene ring and dimethylbenzofluorene. Rings, dimethylindene rings, etc. are also included.

Examples of the “heteroaryl ring” in this specification include heteroaryl rings having 2 to 30 carbon atoms, with heteroaryl rings having 2 to 25 carbon atoms being preferable, and heteroaryl rings having 2 to 20 carbon atoms being more preferable. And, a heteroaryl ring having 2 to 15 carbon atoms is more preferable, and a heteroaryl ring having 2 to 10 carbon atoms is particularly preferable. Examples of the “heteroaryl ring” include heterocycles containing 1 to 5 heteroatoms selected from oxygen, sulfur, nitrogen, selenium, phosphorus, and tellurium in addition to carbon as ring atoms.

Specific "heteroaryl rings" include, for example, pyrrole ring, oxazole ring, isoxazole ring, thiazole ring, isothiazole ring, imidazole ring, oxadiazole ring (furazane ring, etc.), thiadiazole ring, triazole ring, tetra. Sol ring, pyrazole ring, pyridine ring, pyrimidine ring, pyridazine ring, pyrazine ring, triazine ring, indole ring, isoindole ring, 1H-indazole ring, benzoimidazole ring, benzoxazole ring, benzothiazole ring, 1H-benzo Triazole ring, quinoline ring, isoquinoline ring, cinnoline ring, quinazoline ring, quinoxaline ring, phthalazine ring, naphthridine ring, purine ring, pteridine ring, carbazole ring, acridine ring, phenoxathione ring, Phenoxazine ring, phenothiazine ring, phenazine ring, phenaxacillin ring, indolizine ring, furan ring, benzofuran ring, isobenzofuran ring, dibenzofuran ring, thiophene ring, benzothiophene ring, dibenzothiophene Ring, thiantrene ring, indolocarbazole ring, benzoindolocarbazole ring, dibenzoindolocarbazole ring, naphthobenzofuran ring, dioxine ring, dihydroacridine ring, xanthene ring, thioxanthene ring, di Benzodioxine ring, dioxaboranaphthoanthracene ring (5,9-dioxa-13b-bora-13bH-naphtho[3,2,1-de]anthracene ring, etc.), benzoselenophene ring, dibenzosele Nophen ring, azacarbazole ring, azadibenzothiophene ring, azadibenzofuran ring, azadibenzoselenophen ring, azatriphenylene ring, imidazoimidazole ring, indoloindole ring, benzofurocarbazole ring, benzoyl ring. Examples include thienocarbazole ring, indenocarbazole ring and selenophenocarbazole ring, spiro[fluorene-9,9'-xanthene] ring, and spirobi[silafluorene] ring. In addition, in the dihydroacridine ring, xanthene ring, and thioxanthene ring, two of the two hydrogens of methylene in the structure are each substituted with an alkyl such as methyl as the first substituent described later, and dimethyldihydroacridine ring, dimethylxanthene ring, It is also preferable that it is made of a dimethylthioxanthene ring or the like. Additionally, dicyclic bipyridine rings, phenylpyridine rings, and pyridylphenyl rings, and tricyclic terpyridine rings, bispyridylphenyl rings, and pyridylbiphenyl rings, can also be cited as “heteroaryl rings.” In addition, “heteroaryl ring” shall also include pyran ring.

In this specification, the substituent may be substituted with another substituent. For example, a specific substituent may be described as “substituted or unsubstituted.” This means that the specific substituent is substituted with at least one other substituent, or is not substituted. In some cases, it is said that “it may be substituted” to give the same meaning. In this specification, the specific substituent at this time may be referred to as a “first substituent”, and the other substituent mentioned above may be referred to as a “second substituent”.

In this specification, substituent group Z is,

Aryl, which may be substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl, cycloalkyl, cyano, and halogen,

Heteroaryl, which may be substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl, cycloalkyl, cyano, and halogen,

Diarylamino, which may be substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl, cycloalkyl, cyano, and halogen (two aryls may be bonded to each other through a linking group),

Diheteroarylamino, which may be substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl, cycloalkyl, cyano, and halogen (two heteroaryls may be bonded to each other through a linking group),

Arylheteroarylamino, which may be substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl, cycloalkyl, cyano, and halogen (aryl and heteroaryl may be bonded to each other through a linking group),

Diarylboryl, which may be substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl, cycloalkyl, cyano, and halogen (two aryls may be bonded through a single bond or linking group),

Alkyl which may be substituted with at least one group selected from the group consisting of aryl, heteroaryl, cycloalkyl, cyano and halogen,

Cycloalkyl which may be substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl, cycloalkyl, cyano and halogen,

Alkoxy which may be substituted with at least one group selected from the group consisting of aryl, heteroaryl, cycloalkyl, cyano and halogen,

Aryloxy, which may be substituted with at least one group selected from the group consisting of aryl, heteroaryl, alkyl, cycloalkyl, cyano, and halogen,

Consists of substituted silyl, cyano, and halogen.

Aryl, which is the second substituent in each group of substituent group Z, may be further substituted with aryl, heteroaryl, alkyl, cycloalkyl, cyano, or halogen. Similarly, heteroaryl, which is the second substituent, may be substituted with aryl, heteroaryl, It may be substituted with alkyl, cycloalkyl, cyano or halogen.

In this specification, when referring to a “substituent”, unless otherwise specified, it may be any one group selected from the substituent group Z. For example, when a group considered to be “substituted or unsubstituted” is substituted, the group may be substituted with at least one group selected from the substituent group Z.

In this specification, “aryl” refers to, for example, aryl with 6 to 30 carbon atoms, preferably, aryl with 6 to 20 carbon atoms, aryl with 6 to 16 carbon atoms, aryl with 6 to 12 carbon atoms, or aryl with 6 to 12 carbon atoms. Aryl of 10, etc.

Specific examples of “aryl” include a monovalent group obtained by removing one hydrogen from the “aryl ring” described above. For example, monocyclic phenyl, bicyclic biphenylyl (2-biphenylyl, 3-biphenylyl, or 4-biphenylyl), condensed bicyclic naphthyl (1-naphthyl or 2-naphthyl) til), tricyclic terphenylyl (m-terphenyl-2'-yl, m-terphenyl-4'-yl, m-terphenyl-5'-yl, o-terphenyl-3'-yl, o-terphenyl-4'-yl, p-terphenyl-2'-yl, m-terphenyl-2-yl, m-terphenyl-3-yl, m-terphenyl-4-yl, o-terphenyl phenyl-2-yl, o-terphenyl-3-yl, o-terphenyl-4-yl, p-terphenyl-2-yl, p-terphenyl-3-yl, or p-terphenyl-4-yl. 1), condensed tricyclic, acenaphthylene-(1-, 3-, 4-, or 5-) yl, fluorene-(1-, 2-, 3-, 4-, or 9-) yl, phenalen-(1- or 2-) days, phenanthrene-(1-, 2-, 3-, 4-, or 9-) days, or anthracene-(1-, 2-, or 9-) days, Tetracyclic tetraphenylyl (5'-phenyl-m-terphenyl-2-yl, 5'-phenyl-m-terphenyl-3-yl, 5'-phenyl-m-terphenyl-4-yl, or m-quarterphenyl), condensed tetracyclic, triphenylene-(1- or 2-)yl, pyrene-(1-, 2-, or 4-)yl, or naphthacene-(1-, 2-, or 5-) yl, or a condensed pentacyclic system, perylene-(1-, 2-, or 3-) yl, or pentacene-(1-, 2-, 5-, or 6-) yl, etc. . In addition, the monovalent group of spirofluorene, etc. can be mentioned.

In addition, the aryl as the second substituent includes aryl such as phenyl (specific examples are groups described above), alkyl such as methyl (specific examples are groups described later), and cycloalkyl such as cyclohexyl or adamantyl. Structures substituted with at least one group selected from the group consisting of (groups of which specific examples will be described later) are also included.

As an example, a group in which the 9th position of fluorenyl as the second substituent is substituted with aryl such as phenyl, alkyl such as methyl, or cycloalkyl such as cyclohexyl or adamantyl.

“Arylene” is, for example, arylene with 6 to 30 carbon atoms, preferably arylene with 6 to 20 carbon atoms, arylene with 6 to 16 carbon atoms, arylene with 6 to 12 carbon atoms, or arylene with 6 to 12 carbon atoms. 10 arylene, etc.

Specific examples of “arylene” include a divalent group obtained by removing one hydrogen from the above-mentioned “aryl” (monovalent group).

“Heteroaryl” is, for example, heteroaryl with 2 to 30 carbon atoms, preferably heteroaryl with 2 to 25 carbon atoms, heteroaryl with 2 to 20 carbon atoms, heteroaryl with 2 to 15 carbon atoms, or 2 to 2 carbon atoms. 10 heteroaryl, etc. “Heteroaryl” contains one or more heteroatoms selected from oxygen, sulfur, nitrogen, etc. in addition to carbon as ring atoms, preferably 1 to 5 heteroatoms.

Specific examples of “heteroaryl” include a monovalent group in which one hydrogen has been removed from the “heteroaryl ring” described above. For example, pyrrolyl, oxazolyl, isoxazolyl, thiazolyl, isothiazolyl, imidazolyl, oxadiazolyl, thiadiazolyl, triazolyl, tetrazolyl, pyrazolyl, pyridyl, pyrimidinyl, pyridyl. dazinyl, pyrazinyl, triazinyl, indolyl, isoindolyl, 1H-indazolyl, benzoimidazolyl, benzoxazolyl, benzothiazolyl, 1H-benzotriazolyl, quinolinyl, isoquinolinyl, sine Nolinyl, quinazolinyl, quinoxalinyl, phenanthrolinyl, phthalazinyl, naphthyridinyl, purinyl, pteridinyl, carbazolyl, acridinyl, phenoxathiinyl, phenoxazinyl, phenothiazinyl , phenazinyl, phenazacylinyl, indolizinyl, furanyl, benzofuranyl, isobenzofuranyl, dibenzofuranyl, naphthobenzofuranyl, thienyl, benzothienyl, isobenzothienyl, dibenzo Thienyl, naphthobenzothienyl, monovalent group of benzophosphole oxide ring, monovalent group of dibenzophosphole oxide ring, furazanyl, thianthrenyl, indolocarbazolyl, benzoindolocarbazolyl, dibenzo These include indolocarbazolyl, imidazolinyl, or oxazolinyl. In addition, the monovalent group of spiro[fluorene-9,9'-xanthene], the monovalent group of spirobi[silafluorene], and the monovalent group of benzoselenophene can be mentioned.

In addition, heteroaryl as the second substituent includes aryl such as phenyl (specific examples are groups described above), alkyl such as methyl (specific examples are groups described later), and cyclo such as cyclohexyl or adamantyl. Structures substituted with at least one group selected from the group consisting of alkyl (a group whose specific examples will be described later) are also included.

As an example, a group in which the 9th position of carbazolyl as the second substituent is substituted with aryl such as phenyl, alkyl such as methyl, or cycloalkyl such as cyclohexyl or adamantyl. In addition, nitrogen-containing heteroaryls such as pyridyl, pyrimidinyl, triazinyl, and carbazolyl, which are further substituted with phenyl or biphenylyl, are also included in heteroaryl as the second substituent.

“Heteroarylene” is, for example, heteroarylene having 2 to 30 carbon atoms, preferably heteroarylene having 2 to 25 carbon atoms, heteroarylene having 2 to 20 carbon atoms, heteroarylene having 2 to 15 carbon atoms. , or heteroarylene having 2 to 10 carbon atoms, etc. In addition, “heteroarylene” is, for example, a divalent group such as a heterocycle containing 1 to 5 heteroatoms selected from oxygen, sulfur, and nitrogen in addition to carbon as ring atoms.

Specific examples of “heteroarylene” include a divalent group obtained by removing one hydrogen from the above-mentioned “heteroaryl” (monovalent group).

“Diarylamino” is amino in which two aryls are substituted, and the description of “aryl” described above can be cited for details on this aryl.

“Diheteroarylamino” is an amino group in which two heteroaryls are substituted, and the description of “heteroaryl” described above can be cited for details on this heteroaryl.

“Arylheteroarylamino” is an amino group in which aryl and heteroaryl are substituted. For details on aryl and heteroaryl, the explanation of “aryl” and “heteroaryl” described above can be cited.

Two aryls in diarylamino as the first substituent may be bonded to each other through a linking group, and two heteroaryls in diheteroarylamino as the first substituent may be bonded to each other through a linking group, and the first substituent may be bonded to each other through a linking group. Aryl and heteroaryl of arylheteroarylamino as substituents may be bonded to each other through a linking group. Here, the description of “bonding through a linking group” indicates that, for example, two phenyls of diphenylamino form a bond through a linking group, as shown below. This description also applies to diheteroarylamino and arylheteroarylamino, formed from aryl or heteroaryl.

(* indicates binding position.)

^As a linking group _, ^specifically , ^{> O} , _> ^NR >CO, >CS, >SO, >SO ₂ , and >Se. ^{R In} _addition ^{, two R} _{_} ^_ They may be combined with each other through ^Y to form a ring. X ^Y includes >O, >NR ^Y , >C(-R ^Y ) ₂ , >Si(-R ^Y ) ₂ , >S, >CO, >CS, >SO, >SO ₂ , and >Se. and R ^Y is each independently alkyl, cycloalkyl, aryl, or heteroaryl, and these may be substituted with alkyl, cycloalkyl, aryl, or heteroaryl. ^{However ,} _in ^the _case ^where Furthermore, alkenylene can also be mentioned as a linking group. Any hydrogen of the alkenylene may each independently be substituted with ^{R 2} It may be substituted. ^{Two R _} . That is, ^-C ( ^-R

Additionally, in this specification, when it is simply described as “diarylamino”, “diheteroarylamino”, or “arylheteroarylamino”, unless specifically limited, the two aryls of “diarylamino” are each adjacent to the other. “The two heteroaryls of the diheteroarylamino may be bonded to each other through a linking group,” and “The aryl and heteroaryl of the arylheteroarylamino may be bonded to each other through a linking group.” It is said that the explanation “It will be done” has been added.

“Diarylboryl” is a boryl in which two aryls are substituted, and the description of “aryl” described above can be cited for details on this aryl. Additionally, these two aryls are single bonds or linking groups (e.g. -CH=CH-, -CR=CR-, -C≡C-, >NR, >O, >S, >CO, >C( It may be bonded via -R) ₂ , >Si(-R) ₂ , or >Se). Here, R of -CR=CR-, R of >NR, R of >C(-R) ₂ , and R of >Si(-R) are aryl, heteroaryl, diarylamino, alkyl, alkenyl. , alkynyl, cycloalkyl, alkoxy, or aryloxy, and at least one hydrogen in R may be further substituted with aryl, heteroaryl, alkyl, alkenyl, alkynyl, or cycloalkyl. Additionally, two adjacent R groups may combine to form a ring, forming cycloalkylene, arylene, and heteroarylene. Details of the substituents listed here include the description of “aryl”, “arylene”, “heteroaryl”, “heteroarylene”, and “diarylamino” described above, and “alkyl” and “alkyl” described later. The descriptions of “kenyl”, “alkynyl”, “cycloalkyl”, “cycloalkylene”, “alkoxy”, and “aryloxy” may be cited. Additionally, in the case where "diarylboryl" is simply described in this specification, unless specifically limited, an explanation is added that "the two aryls of diarylboryl may be bonded to each other through a single bond or a linking group." It is said that it exists.

“Alkyl” may be either straight chain or branched chain, for example, straight chain alkyl with 1 to 24 carbon atoms or branched chain alkyl with 3 to 24 carbon atoms, preferably alkyl with 1 to 18 carbon atoms (3 to 2 carbon atoms). Branched chain alkyl with 18 carbon atoms), Alkyl with 1 to 12 carbon atoms (branched chain alkyl with 3 to 12 carbon atoms), Alkyl with 1 to 6 carbon atoms (branched chain alkyl with 3 to 6 carbon atoms), Alkyl with 1 to 5 carbon atoms (3 carbon atoms) branched chain alkyl of ~5), alkyl of 1 to 4 carbon atoms (branched chain alkyl of 3 to 4 carbon atoms), etc.

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

“Alkylene” is a divalent group obtained by removing the hydrogen of any one of “alkyl”, for example, methylene, ethylene, and propylene.

Regarding "alkenyl", the description of "alkyl" mentioned above can be referred to. It is a group in which the C-C single bond in the structure of "alkyl" is replaced with a C=C double bond, and it is a group containing not only one but two or more single bonds. Also includes groups where the bond is replaced by a double bond (also called alkadiene-yl or alkatrien-yl).

“Alkenylene” is a divalent group obtained by removing any hydrogen of “alkenyl”, and examples include vinylene.

Regarding "alkynyl", the explanation of "alkyl" mentioned above can be referred to. It is a group in which the C-C single bond in the structure of "alkyl" is replaced with a C≡C triple bond, and it has not only one but two or more single bonds. Also included are groups where the bond is replaced by a triple bond (also called alkadiin-yl or alkatriin-yl).

“Cycloalkyl” is, for example, cycloalkyl with 3 to 24 carbon atoms, preferably cycloalkyl with 3 to 20 carbon atoms, cycloalkyl with 3 to 16 carbon atoms, cycloalkyl with 3 to 14 carbon atoms, and 3 to 12 carbon atoms. cycloalkyl, cycloalkyl with 5 to 10 carbon atoms, cycloalkyl with 5 to 8 carbon atoms, cycloalkyl with 5 to 6 carbon atoms, or cycloalkyl with 5 carbon atoms, etc.

Specific “cycloalkyl” includes, for example, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl, or alkyl of these with 1 to 5 carbon atoms or 1 to 4 carbon atoms (especially methyl) substituent, bicyclo[1.1.0]butyl, bicyclo[1.1.1]pentyl, bicyclo[2.1.0]pentyl, bicyclo[2.1.1]hexyl, bicyclo[3.1.0]hexyl, Cyclo[2.2.1]heptyl (norbornyl), bicyclo[2.2.2]octyl, adamantyl, diamantyl, decahydronaphtharenyl, or decahydroazulenyl.

“Cycloalkylene” is, for example, cycloalkylene with 3 to 24 carbon atoms, preferably cycloalkylene with 3 to 20 carbon atoms, cycloalkylene with 3 to 16 carbon atoms, and cycloalkylene with 3 to 14 carbon atoms. , cycloalkylene with 3 to 12 carbon atoms, cycloalkylene with 5 to 10 carbon atoms, cycloalkylene with 5 to 8 carbon atoms, cycloalkylene with 5 to 6 carbon atoms, or cycloalkylene with 5 carbon atoms, etc.

Specific examples of “cycloalkylene” include structures in which one hydrogen is removed from the above-mentioned “cycloalkyl” (monovalent group) to form a divalent group.

“Cycloalkenyl” refers to a group having a structure in which at least one set of single bonds between two carbons in the above-mentioned “cycloalkyl” is a double bond (for example, -CH ₂ -CH ₂ - is - CH=CH-substituted group) and groups that do not correspond to aryl can be mentioned. Specifically, 1-cyclohexenyl, 1-cyclopentenyl, etc. can be mentioned.

“Alkoxy” is a group represented by “Alk-O- (Alk is alkyl),” and the above-mentioned explanation of “alkyl” can be cited for details on this alkyl.

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

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

“Triarylsilyl” is a silyl group substituted with three aryls, and the description of “aryl” described above can be cited for details on this aryl.

Specific “triarylsilyl” includes, for example, triphenylsilyl, diphenylmononaphthylsilyl, monophenyldinaphthylsilyl, or trinaphthylsilyl.

“Trialkylsilyl” is a silyl group substituted with three alkyls, and the description of “alkyl” described above can be cited for details on this alkyl.

Specific “trialkylsilyl” includes, for example, trimethylsilyl, triethylsilyl, trin-propylsilyl, triisopropylsilyl, trin-butylsilyl, triisobutylsilyl, tris-butylsilyl, trit- Butylsilyl, ethyldimethylsilyl, n-propyldimethylsilyl, isopropyldimethylsilyl, n-butyldimethylsilyl, isobutyldimethylsilyl, s-butyldimethylsilyl, t-butyldimethylsilyl, methyldiethylsilyl, n-propyldi. Ethylsilyl, isopropyldiethylsilyl, n-butyldiethylsilyl, s-butyldiethylsilyl, t-butyldiethylsilyl, methyldi-n-propylsilyl, ethyldi-n-propylsilyl, n-butyldi-n- Propylsilyl, s-butyldin-propylsilyl, t-butyldin-propylsilyl, methylisopropylsilyl, ethyldiisopropylsilyl, n-butyldiisopropylsilyl, s-butyldiisopropylsilyl, or t -Butyldiisopropylsilyl, etc.

“Tricycloalkylsilyl” is a silyl group substituted with three cycloalkyls, and the description of “cycloalkyl” described above can be cited for details on this cycloalkyl.

Specific “tricycloalkylsilyl” includes, for example, tricyclopentylsilyl or tricyclohexylsilyl.

“Dialkylcycloalkylsilyl” is a silyl group substituted with two alkyls and one cycloalkyl, and the description of “alkyl” and “cycloalkyl” above can be referred to for details of this alkyl and cycloalkyl. .

“Alkyldicycloalkylsilyl” is a silyl group substituted with one alkyl and two cycloalkyl, and the description of “alkyl” and “cycloalkyl” described above can be cited for details of this alkyl and cycloalkyl. .

“Halogen” is fluorine, chlorine, bromine, or iodine, preferably fluorine, chlorine, or bromine, more preferably fluorine or chlorine, and fluorine is more preferable.

<When two groups bonded to the same atom bond to each other>

In this specification, when it is said that two groups bonded to the same atom may be bonded to each other to form a ring, they may be bonded by a single bond or linking group (collectively referred to as a linking group), and the linking group is -CH ₂ -CH ₂ -, -CHR-CHR-, -CR ₂ -CR ₂ -, -CH=CH-, -CR=CR-, -C≡C-, -N(-R)-, -O-, -S-, -C(-R) ₂ -, -C(=O)-, -Si(-R) ₂ -, or -Se-, and examples include the following structures. In addition, R of -CHR-CHR-, R of -CR ₂ -CR ₂ -, R of -CR=CR-, R of -N(-R)-, R of -C(-R) ₂ -, and R of -Si(-R) ₂ - are each independently hydrogen, aryl optionally substituted with alkyl or cycloalkyl, heteroaryl optionally substituted with alkyl or cycloalkyl, or alkyl optionally substituted with cycloalkyl. , alkenyl which may be substituted with alkyl or cycloalkyl, alkynyl which may be substituted with alkyl or cycloalkyl, or cycloalkyl which may be substituted with alkyl or cycloalkyl. Additionally, two adjacent R's may combine to form a ring, forming cycloalkylene, arylene, or heteroarylene.

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

The position where two R are bonded by the linking group is not particularly limited as long as it is a position where bonding is possible, but it is preferable to bond at the most adjacent position. For example, when the two groups are phenyl, "C" in phenyl or It is preferable to bond at ortho (second position) positions based on the bonding position (first position) of “Si” (refer to the above structural formula).

1. Polycyclic aromatic compounds

<Description of the overall structure of polycyclic aromatic compounds>

The polycyclic aromatic compound of the present invention is represented by formula (1) or formula (2).

In formulas (1) and (2), ring A, ring B, ring C, ring D, ring E, and ring F are each independently a substituted or unsubstituted aryl ring or a substituted or unsubstituted heteroaryl ring. .

In the polycyclic aromatic compound represented by formula (1) or formula (2), all three monocycles containing boron as a ring atom are 4π semi-aromatic, and when they receive electrons, they approach stable aromaticity, so they have high electron acceptance. . In addition, the planarity is high, and when it is made into a thin film, it is easy to get close to adjacent molecules, and carrier movement becomes faster. From these characteristics, the polycyclic aromatic compound represented by formula (1) or formula (2) has excellent electron transport properties and can be used as a material for forming an electron transport layer or a material for forming a hole blocking layer.

<Explanation of ring structure in polycyclic aromatic compounds>

In equations (1) and (2), “A”, “B”, “C”, “D”, “E”, and “F” within the circles are symbols representing the ring structure represented by each circle. The structure represented by formula (1) or formula (2) is a ring structure formed by connecting at least six aromatic rings, which are the A ring, B ring, C ring, D ring, E ring, and F ring, with boron and carbon. It has a structure. The ring structure formed is a condensed ring structure composed of at least 12 rings.

The A ring, B ring, and C ring each form a trivalent group having bonding hands to three consecutive elements (preferably carbon) in the ring of the aryl ring or heteroaryl ring in the structure. Each of these three bonding hands bonds to a different ring, and the bonding hands themselves form different rings. On the other hand, when the A ring and the E ring, the B ring and the F ring, and the C ring and the D ring are each bonded to each other through a single bond or linking group, the A ring, the B ring, and the C ring each form a tetravalent group. Among the A ring, B ring, and C ring, it is preferable that the ring containing the above three bonding elements as a ring constituent element is a 5-membered ring or a 6-membered ring. This ring may be further condensed with another ring. An example of a 6-membered ring includes a benzene ring. Examples of a 6-membered ring condensed with another ring include a naphthalene ring, anthracene ring, quinoline ring, isoquinoline ring, quinazoline ring, dibenzofuran ring, dibenzothiophene ring, and carbazole ring. Examples of 5-membered rings include furan rings, thiophene rings, pyrrole rings, and thiazole rings. Examples of a 5-membered ring condensed with another ring include a benzofuran ring, a benzothiophene ring, and an indole ring.

A benzene ring is preferable as the aryl ring or heteroaryl ring in each of ring A, ring B, and ring C.

The D ring, E ring, and F ring each form a divalent group having bonding hands to two elements (preferably carbon) adjacent to each other in the ring of the aryl ring or heteroaryl ring in the structure. These two bonding hands each bind to different rings, and the bonding hands themselves form different rings. On the other hand, when the A ring and the E ring, the B ring and the F ring, and the C ring and the D ring are each bonded to each other through a single bond or linking group, the D ring, the E ring, and the F ring each form a trivalent group. Among the D ring, E ring, and F ring, the ring containing the above two bonding elements as a ring constituent element is preferably a 5-membered ring or a 6-membered ring. This ring may be further condensed with another ring. Examples of 6-membered rings include benzene rings and pyridine rings. Examples of a 6-membered ring condensed with another ring include naphthalene ring, quinoline ring, benzofuran ring, benzothiophene ring, indole ring, benzoselenophene ring, dibenzofuran ring, dibenzothiophene ring, carbazole ring, and dibenzothiophene ring. Benzo-selenophen pills, etc. can be mentioned. Examples of the 5-membered ring include a furan ring, a thiophene ring, a pyrrole ring, a thiazole ring, and a selenophene ring. Examples of a 5-membered ring condensed with another ring include a benzofuran ring, a benzothiophene ring, an indole ring, and a benzoselenophene ring.

The aryl ring or heteroaryl ring in the D ring, E ring, and F ring is each independently a benzene ring, a furan ring, a thiophene ring, a pyrrole ring, a thiazole ring, a benzofuran ring, a benzothiophene ring, and a benzoseleno ring. A fen ring or an indole ring is preferable, and a benzene ring is more preferable.

In the polycyclic aromatic compound represented by formula (1) or formula (2), the A ring and the E ring may be bonded through a single bond or linking group not shown in the formula (1) and formula (2), and the B ring and the F ring The C ring and D ring may be bonded through a single bond or linking group not shown in formulas (1) and (2). do. That is, the rings may be further bonded to each other through a single bond or linking group at one, two, or three positions among the three broken line portions shown in each of the formulas (1') and (2') below. When the A ring, the E ring, the B ring, the F ring, and the C ring and D ring all have an additional bond through a single bond or linking group as described above, the polycyclic aromatic compound represented by formula (1) or formula (2) is: It has a condensed ring structure consisting of at least 15 rings.

As a linking group, -N(-R ^NG )-, -O-, -C(-R ^CG ) _2- , -Si(-R ^IG ) _2- , -S-, -Se-, -C(-R ^DG ) =C(-R ^DG )-, etc. R ^NG , R ^CG , R ^IG , and R ^DG are each independently hydrogen, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted alkyl, or substituted or unsubstituted cycloalkyl, Two R ^CG may be bonded to each other to form a ring, and two R ^IG may be bonded to each other to form a ring. R ^NG is preferably substituted or unsubstituted aryl, and more preferably unsubstituted phenyl. As a linking group here, -O-, -C(-Me) ₂ -, -C(-Ph) ₂ -, -Si(-Ph) ₂ -, -S-, -Se-, or -CH=CH - This is preferable. For -C(-Ph) ₂ -, it is more preferable that the two Ph are bonded to each other through a single bond to form a ring, and for -Si(-Ph) ₂ -, the two Ph are bonded to each other through a single bond. It is more preferable that they are bonded through to form a ring. It is preferable that the ring atom in the aryl ring or heteroaryl ring of ring A, ring B, ring C, ring D, ring E, or ring F is directly bonded to the linking group.

<Description of substituents in polycyclic aromatic compounds>

In formulas (1) and (2), in the substituted or unsubstituted aryl ring or substituted or unsubstituted heteroaryl ring in ring A, ring B, ring C, ring D, ring E, and ring F, , the substituent when saying “substituted or unsubstituted (substituted or unsubstituted)” is preferably substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, triarylsilyl, or cyano. As the second substituent, methyl, trifluoromethyl, halogen, cyano, etc. are also preferable.

Specific examples of preferable substituents include the following. In the structural formula below, * represents the bonding position of each substituent.

From the viewpoint of synthesis and sublimation, it is preferable that none of the aryl rings or heteroaryl rings in the A ring, B ring, C ring, D ring, E ring, and F ring have a substituent.

<Polycyclic aromatic compound represented by formula (1X) or formula (2X)>

A preferred example of the polycyclic aromatic compound represented by formula (1) is a polycyclic aromatic compound represented by formula (1X), and a preferred example of a polycyclic aromatic compound represented by formula (2) is a polycyclic aromatic compound represented by formula (2X). I can hear it.

“A”, “B”, “C”, “D”, “E”, and “F” in equation (1) are “a”, “b”, and “c” in equation (1X), respectively. 」, 「d」, 「e」, and 「f」, and 「A」, 「B」, 「C」, 「D」, 「E」, and 「F」 in equation (2) are respectively, Corresponds to “a”, “b”, “c”, “d”, “e”, and “f” in equation (2X).

In formula (1X) and formula (2X), Z is each independently -C(-R ^Z )= or -N=. -N = Z is preferably 0 to 3 in each of the a ring, b ring, c ring, d ring, e ring, and f ring, more preferably 0 to 2, and even more preferably 0 to 1. desirable. It is preferable that all Zs are -C(-R ^Z )=.

R ^Z is each independently hydrogen or a substituent. As a substituent, reference may be made to the description of the substituent in Formula (1) and Formula (2). R ^Z is preferably hydrogen or is preferably bonded to an adjacent R ^Z as described later. Two adjacent ^R As the substituent at this time, the description of the substituent in Formula (1) and Formula (2) can be referred to. Z=Z is each independently >NR ^NZ , >O, >C(-R ^CZ ) ₂ , >Si(-R ^IZ ) ₂ , >S, or >Se, preferably >NR ^NZ , >O, > It may be S, or >Se. R ^NZ , R ^CZ and R ^IZ are each independently hydrogen, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted alkyl, or substituted or unsubstituted cycloalkyl, and two R ^CZ are combined with each other to form a ring. may be formed, and two R ^IZ may be bonded to each other to form a ring. R ^NZ is preferably substituted or unsubstituted aryl, and more preferably unsubstituted phenyl.

A structural example of a ring containing Z is shown below as an example of a ring (d ring, e ring, f ring) containing four rings of Z and being a divalent group. Meanwhile, in the formulas below, R has the same meaning as R ^Z , but does not mean hydrogen and does not mean that R is bonded to each other. R ⁰ has the same meaning as R ^Z , but does not mean that R ⁰ is bonded to each other. In addition, n is an integer from 0 to 4, and R ^N and R ^C are hydrogen, aryl which may be substituted with alkyl or cycloalkyl, heteroaryl which may be substituted with alkyl or cycloalkyl, and heteroaryl which may be substituted with cycloalkyl. It is alkyl or cycloalkyl which may be substituted with alkyl, and two R ^C may be bonded to each other to form a ring.

In each of the above partial structures, R is preferably aryl or heteroaryl, and more preferably phenyl. n is preferably 0 or 1, and is more preferably 0. R ⁰ is preferably hydrogen, aryl, or heteroaryl, and more preferably hydrogen.

Similar structural examples can be given for rings (a-ring, b-ring, c-ring) that contain three Z and are trivalent groups.

In formulas (1 , may be further bonded through a single bond or linking group not shown in formula (2X), and the c ring and d ring may be further bonded through a single bond or linking group not shown in formula (1X) and formula (2X). This means that in the polycyclic aromatic compound represented by formula (1) or formula (2), ring A and ring E may be bonded through a single bond or linking group not shown in formula (1) and formula (2), and ring B and ring F The ring may be bonded through a single bond or linking group not shown in formulas (1) and (2), and the C ring and D ring may be bonded through a single bond or linking group not shown in formulas (1) and (2). It's the same as saying it's okay to have it.

The a ring and the e ring, the b ring and the f ring, and the c ring and the d ring may be bonded so that the Z at the closest position in each combination is the carbon bonded to the single bond or linking group, and may be bonded to the substituent R ^Z One of the hydrogens may be bonded to the single bond or bonding hand of the connecting group by substitution, and two adjacent ^R It may be bonded to a ring atom or a substituent.

In formula (1X) and formula (2X), any of the following cases are preferable.

a) All Zs are -C(-H)=.

b) In each of a ring, b ring, and c ring, one Z=Z is >NR ^NZ , >O, >C(-R ^CZ ) ₂ , >Si(-R ^IZ ) ₂ , >S, or > Se, and the remaining Zs are each independently -C(-R ^Z )=.

c) In each of the d ring, e ring, and f ring, one Z=Z is >NR ^NZ , >O, >C(-R ^CZ ) ₂ , >Si(-R ^IZ ) ₂ , >S, or > It is Se, and the remaining two Zs in each of the d ring, e ring, and f ring are adjacent, and all are -C(-R ^Z )=, and the two R ^Z are bonded to each other and the two carbons to which they bond are It forms a benzene ring together, and the remaining Zs are each independently -C(-R ⁰ )=.

<Formula (1-a), Formula (1-b), Formula (1-c), Formula (1-d), Formula (1-e), Formula (2-a), Formula (2-b), Equation (2-c), Equation (2-d) and Equation (2-e)>

Preferred examples of polycyclic aromatic compounds represented by formula (1X) include formula (1-a), formula (1-b), formula (1-c), formula (1-d), and formula (1-e). Preferred examples of the polycyclic aromatic compound represented by any one formula selected from the group consisting of, and the polycyclic aromatic compound represented by formula (2X) include formula (2-a), formula (2-b), and formula (2- c), a polycyclic aromatic compound represented by any one formula selected from the group consisting of formula (2-d) and formula (2-e) can be presented.

Equation (1-a), Equation (1-b), Equation (1-c), Equation (1-d), Equation (1-e), Equation (2-a), Equation (2-b), Equation In (2-c), formula (2-d) and formula (2-e), L is each independently >NR ^NZ , >O, >C(-R ^CZ ) ₂ , >Si(-R ^IZ ) ₂ , >S, or >Se, and is preferably >NR ^NZ , >O, >S, or >Se. R ^NZ is preferably substituted or unsubstituted aryl, and more preferably unsubstituted phenyl. R ^Z has the same meaning as R ^Z in formulas (1) and (2), and each independently represents hydrogen or a substituent. As a substituent, reference may be made to the description of the substituent in Formula (1) and Formula (2). It is preferable that R ^Z is each independently hydrogen or is bonded to an adjacent R ^Z , and it is more preferable that all R ^Z are hydrogen.

<Substitution by deuterium>

All or part of the hydrogen in the structure represented by formula (1) or formula (2) may be deuterium. Structure represented by formula (1X) or formula (2X), formula (1-a), formula (1-b), formula (1-c), formula (1-d), formula (1-e), formula The same applies to the structure represented by (2-a), formula (2-b), formula (2-c), formula (2-d), or formula (2-e).

For example, in the compound represented by formula (1) or formula (2), the aryl ring or heteroaryl ring in ring A, ring B, ring C, ring D, ring E, and ring F, ring A , hydrogen in the substituents in the B ring, C ring, D ring, E ring, and F ring may be substituted with deuterium, but among these, all or part of the hydrogen in aryl or heteroaryl is substituted with deuterium. can be mentioned. Also, from the viewpoint of durability, it is preferable that all or part of the hydrogen in the compound represented by formula (1) or formula (2) is deuterated.

<Specific examples of polycyclic aromatic compounds>

Examples of polycyclic aromatic compounds of the present invention include compounds represented by any of the following structural formulas.

<Method for producing polycyclic aromatic compounds>

The polycyclic aromatic compound represented by formula (1) or formula (2) can be manufactured using the compound represented by formula (SM) as a raw material.

First, the compound represented by the formula (SM) used as a raw material will be described.

During the ceremony (SM),

The A ring, B ring, C ring, D ring, E ring, and F ring are each independently a substituted or unsubstituted aryl ring or a substituted or unsubstituted heteroaryl ring, and the A ring and the E ring are formed through a single bond or linking group. Ring B and F may be further bonded through a single bond or linking group, and Ring C and D may be further bonded through a single bond or linking group. At least in the structure represented by formula (SM) One hydrogen may be substituted with deuterium.

For details and preferred ranges of the A ring, B ring, C ring, D ring, E ring, and F ring in formula (SM), the A ring, B ring, C ring, and D ring in formula (1) and formula (2) are described. , E ring, and F ring can each refer to the description of the preferred range. However, in the compound represented by formula (SM), the D ring, E ring, and F ring each have a bond to one atom (preferably carbon) of the aryl ring or heteroaryl ring in the structure. It forms a monovalent group. Each is bonded to a different ring by this one bond. On the other hand, when the A ring and the E ring, the B ring and the F ring, and the C ring and the D ring are each bonded to each other through a single bond or linking group, the D ring, the E ring, and the F ring each form a divalent group.

A preferable example of a compound represented by the formula (SM) includes a compound represented by the formula (SM-X).

In formula (SM-X),

Z is each independently -C(-R ^Z )= or -N=,

R ^Z is each independently hydrogen or a substituent,

Two adjacent ^R

Z=Z may each independently be >NR ^NZ , >O, >C(-R ^CZ )2, >Si(-R ^IZ )2, >S, or >Se, and R ^NZ , R ^CZ and R ^IZ are Each is independently hydrogen, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted alkyl, or substituted or unsubstituted cycloalkyl, and two R ^CZ may be bonded to each other to form a ring. Alternatively, two R ^IZ may be combined with each other to form a ring,

The a ring and the e ring may be further bonded through a single bond or linking group, the b ring and f ring may be further bonded through a single bond or linking group, and the c ring and d ring may be further bonded through a single bond or linking group,

At least one hydrogen in the structure represented by formula (SM-X) may be substituted with deuterium.

For the preferable ranges of Z and R ^Z , reference can be made to the description of the preferable ranges of Z and R ^Z in formulas (1X) and (2X).

Specific examples of compounds represented by formula (SM-X) include the following formulas (SM-a), formula (SM-b), formula (SM-c), formula (SM-d), and formula (SM-e). The compounds shown are listed. A polycyclic aromatic compound represented by formula (1-a) or formula (2-a) can be produced using the compound represented by formula (SM-a) as a raw material, and the compound represented by formula (SM-b) As a raw material, a polycyclic aromatic compound represented by formula (1-b) or formula (2-b) can be manufactured, and by using a compound represented by formula (SM-c) as a raw material, formula (1-c) ) or a polycyclic aromatic compound represented by the formula (2-c) can be produced, using the compound represented by the formula (SM-d) as a raw material, represented by the formula (1-d) or formula (2-d) polycyclic aromatic compounds can be produced, and polycyclic aromatic compounds represented by formula (1-e) or formula (2-e) can be manufactured using the compound represented by formula (SM-e) as a raw material. there is.

Particularly preferred examples of the compound represented by formula (SM-X) include compounds represented by the following formula (SM-1) or formula (SM-2).

The polycyclic aromatic compound represented by formula (1) or (2) is synthesized by referring to the method described in Eur.J.Org.Chem.2019, 6783-6795 using a compound represented by formula (SM) (first reaction ), can be produced by introducing boron therein (second reaction). In the second reaction, a tandem hetero Friedel Crafts reaction (successive aromatic electron substitution reaction, the same applies hereinafter) can be used.

The second reaction is a reaction to introduce boron that binds the condensed ring containing the A ring (a ring) to the F ring (f ring), as shown in Scheme (1) below. A boronating agent is added to an alkyne, and the D ring (d ring) to F ring (f ring) adjacent to the resulting alkenyl cation undergoes a Friedelcraft reaction, thereby obtaining the target product. In order to capture the acid produced, the desired reaction can be promoted by adding a Bronsted base such as 2,6-di-tert-butyl pyridine.

By appropriately selecting the raw materials used, any one to three of the polycyclic aromatic compounds having substituents at the desired positions, the A ring and the E ring, the B ring and the F ring, and the C ring and the D ring are each bonded to each other through a single bond or linking group, Polycyclic aromatic compounds can be synthesized.

Specific examples of solvents used in the above reaction include orthodichlorobenzene, metadichlorobenzene, paradichlorobenzene, 1,2,4-trichlorobenzene, t-butylbenzene, xylene, and mesitylene.

On the other hand, examples of the boronating agent used in the scheme (1) include boron halides such as boron trifluoride, boron trichloride, boron tribromide, and boron triiodide, boron alkoxides, and boron aryloxides. .

Meanwhile, the Brønsted base used in the scheme (1) includes N,N-diisopropylethylamine, triethylamine, 2,2,6,6-tetramethylpiperidine, 1,2,2, Examples include 6,6-pentamethylpiperidine, N,N-dimethylaniline, N,N-dimethyltoluidine, 2,6-lutidine, and 2,6-di-tert-butylpyridine.

It is a compound represented by one formula (SM), and in the above reaction, a formula (1) compound and a formula (2) compound may be produced simultaneously. In that case, the two can be separated and purified by appropriate means after production. . Examples of separation and purification means include chromatography such as gel permeation chromatography (GPC).

In addition, the polycyclic aromatic compounds of the present invention include those in which at least some of the hydrogen atoms are replaced with deuterium, and such compounds can be synthesized in the same manner as above by using raw materials in which the desired position is deuterated.

2. Organic devices

The polycyclic aromatic compound of the present invention can be used as a material for organic devices. Examples of organic devices include organic electroluminescent elements, organic field-effect transistors, and organic thin-film solar cells. The polycyclic aromatic compound of the present invention is preferably used as a material for forming one or more organic layers in an organic electroluminescent device.

<2-1. Organic electroluminescent device>

2-1-1. Structure of organic electroluminescent device

1 is a schematic cross-sectional view showing an example of an organic EL 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. A hole transport layer 104 provided on (103), a light-emitting layer 105 provided on the hole transport layer 104, an electron transport layer 106 provided on the light-emitting layer 105, and an electron provided on the electron transport layer 106. It has an injection layer 107 and a cathode 108 provided on the electron injection layer 107.

In addition, the organic EL element 100 reverses the manufacturing order, for example, a substrate 101, a cathode 108 provided on the substrate 101, and an electron injection layer provided on the cathode 108 ( 107), an electron transport layer 106 provided on the electron injection layer 107, a light emitting layer 105 provided on the electron transport layer 106, a hole transport layer 104 provided on the light emitting layer 105, and a hole transport layer. It may be configured to include a hole injection layer 103 provided on (104) and an anode 102 provided on the hole injection layer 103.

It is not necessary to have all of the above layers, and the minimum structural unit is 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 a layer installed arbitrarily. In addition, each of the above layers may be composed of a single layer or may be composed of multiple layers.

As aspects of the layers constituting the organic EL element, in addition to the above-mentioned “substrate/anode/hole injection layer/hole transport layer/light-emitting layer/electron transport layer/electron injection layer/cathode”, “substrate/anode/hole transport layer/cathode” 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” /light-emitting layer/electron transport layer/cathode”, “substrate/anode/light-emitting layer/electron transport layer/cathode”, or “substrate/anode/light-emitting layer/electron injection layer/cathode” may be used.

The organic EL element may further have one or both of an electron blocking layer (electron blocking layer) and a hole blocking layer (hole blocking layer). The electron blocking layer has a LUMO shallower than that of the light-emitting layer and a HOMO closer to the light-emitting layer or the hole transport layer, and is disposed between the light-emitting layer and the hole transport layer. Since electrons remain in the light-emitting layer and do not leak out to the hole transport layer, shortening of the lifespan due to deterioration of the hole transport layer and reduction in efficiency due to a decrease in recombination efficiency can be prevented. The hole blocking layer has a HOMO that is deeper than the light-emitting layer and a LUMO that is closer to the light-emitting layer or the hole transport layer, and is disposed between the light-emitting layer and the electron transport layer. Since the holes remain in the light-emitting layer and do not leak out to the electron transport layer, shortening of the lifespan due to deterioration of the electron transport layer and reduction in efficiency due to a decrease in recombination efficiency can be prevented. The hole injection/transport layer may also serve as an electron blocking layer. The electron injection/transport layer may also serve as a hole blocking layer.

The organic EL element may further have a high T1 layer. The high T1 layer has a T1 higher than the host compound, assisting dopant compound, or emitting dopant compound used in the light-emitting layer, and is disposed between the light-emitting layer and the hole transport layer and/or between the light-emitting layer and the electron blocking layer. The value of T1 energy varies depending on the light-emitting mechanism of the device, but has a higher T1 than the compound used as the host. By having a high T1 layer around the light-emitting layer, triplet energy is confined and triplet energy, which does not normally lead to light emission in fluorescent molecules, is converted into singlet energy, thereby achieving high efficiency. The hole injection/transport layer or the electron blocking layer may also serve as a high T1 layer. The electron injection/transport layer or the hole blocking layer may also serve as a high T1 layer.

The polycyclic aromatic compound of the present invention is preferably used as a material for forming an electron transport layer or a material for forming a hole blocking layer, and is more preferably used as a material for forming an electron transport layer.

2-1-2. Substrate in organic electroluminescent device

The substrate 101 is a support for the organic EL element 100, and usually quartz, glass, metal, plastic, etc. are 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, etc. are used. Among them, glass plates and plates made of transparent synthetic resins such as polyester, polymethacrylate, polycarbonate, and polysulfone are preferable. In the case of a glass substrate, soda lime glass, alkali-free glass, etc. are used, and the thickness may be sufficient to maintain mechanical strength. In addition, in order to increase the gas barrier property, the substrate 101 may be formed with a gas barrier film such as a dense silicon oxide film on at least one side. In particular, a plate, film or sheet made of synthetic resin with low gas barrier property may be used as the substrate. When using (101), it is desirable to form a gas barrier film.

2-1-3. Anode in organic electroluminescent device

The anode 102 serves to inject holes into the light emitting layer 105. In addition, when at least one of the hole injection layer 103 and the hole transport layer 104 is provided between the anode 102 and the light emitting layer 105, holes are injected into the light emitting layer 105 through these layers. do.

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

2-1-4. Hole injection layer, 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 holes injected from the anode 102 or holes injected from the anode 102 through the hole injection layer 103 to the light emitting layer 105. The hole injection layer 103 and the hole transport layer 104 are formed by laminating or mixing one or two or more types of hole injection/transport materials, respectively. Additionally, an inorganic salt such as iron (III) chloride may be added to the hole injection/transport material to form a layer.

As a 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 desirable to have high hole injection efficiency and efficiently transport the injected holes. To achieve this, it is desirable to use a material that has a small ionization potential, has a large hole mobility, has excellent stability, and is unlikely to generate trapping impurities during production and use.

Materials forming the hole injection layer 103 and the hole transport layer 104 include compounds conventionally used as hole charge transport materials in photoconductive materials, p-type semiconductors, and hole injection layers and holes in organic EL devices. Any compound can be selected and used among known compounds used in the transport layer. Specific examples of these include carbazole derivatives (N-phenylcarbazole, polyvinylcarbazole, etc.), biscarbazole derivatives such as bis(N-arylcarbazole) or bis(N-alkylcarbazole), and triarylamine. Derivatives (polymers with aromatic tertiary amino in the main or side chain, 1,1-bis(4-di-p-tolylaminophenyl)cyclohexane, N,N'-diphenyl-N,N'-di (3-methylphenyl)-4,4'-diaminobiphenyl, N,N'-diphenyl-N,N'-dinaphthyl-4,4'-diaminobiphenyl, N,N'-diphenyl -N,N'-di(3-methylphenyl)-4,4'-diphenyl-1,1'-diamine, N,N'-dinaphthyl-N,N'-diphenyl-4,4'- Diphenyl-1,1'-diamine, N ⁴ ,N ^{4 '} -diphenyl-N ⁴ ,N ^4' -bis(9-phenyl-9H-carbazol-3-yl)-[1,1'-bi Phenyl]-4,4'-diamine, N ⁴ ,N ⁴ ,N ^{4 '} ,N ^4' -tetra[1,1'-biphenyl]-4-yl)-[1,1'-biphenyl]- Triphenylamine derivatives such as 4,4'-diamine, 4,4',4"-tris(3-methylphenyl(phenyl)amino)triphenylamine, starburstamine derivatives, etc.), stilbene derivatives, phthalocyanine derivatives (free) metal, copper phthalocyanine, etc.), pyrazoline derivatives, hydrazone compounds, benzofuran derivatives or thiophene derivatives, oxadiazole derivatives, quinoxaline derivatives (e.g. 1,4,5,8,9,12-hexaaza triphenylene-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-mentioned monomer in the side chain. , polyvinylcarbazole, polysilane, etc. are preferable, but there is no particular limitation as long as it is a compound that can form a thin film necessary for manufacturing a light-emitting device, can inject holes from the anode, and can further transport holes.

Additionally, it is 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 with good electron donating properties or a compound with good electron accepting properties. For doping of electron-donating materials, strong electron acceptors such as tetracyanoquinonedimethane (TCNQ) or 2,3,5,6-tetrafluorotetracyano-1,4-benzoquinonedimethane (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. Pfeiffer, T. Fritz, K. Leo, Appl. Phys. Lett., 73(6), 729-731 (1998). These generate so-called holes through an electron transfer process in an electron-donating base material (hole transport material). Depending on the number and mobility of holes, the conductivity of the base material changes significantly. As matrix materials with hole transport properties, for example, benzidine derivatives (TPD, etc.) or starburst amine derivatives (TDATA, etc.), or specific metal phthalocyanines (especially zinc phthalocyanine (ZnPc), etc.) are known (Japanese Patent Publication). Publication No. 2005-167175).

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

2-1-5. Emitting layer in organic electroluminescent device

The light-emitting layer 105 is a layer that emits light by recombining holes injected from the anode 102 and electrons injected from the cathode 108 between electrodes to which an electric field is applied. The material forming the light-emitting layer 105 may be any compound (luminescent compound) that is excited and emits light by recombination of holes and electrons. It can form a stable thin film shape and has strong luminescence (fluorescence) efficiency in the solid state. It is preferable that it is a compound representing .

The light-emitting layer may be a single layer or may be composed of multiple layers, and is formed of materials for the light-emitting layer (host material and dopant material). The host material and the dopant material may be one type or a combination of multiple types. The dopant material may be contained entirely or partially in the host material. As a doping method, it can be formed by co-deposition with the host material, but may be deposited simultaneously after mixing with the host material in advance.

The amount of host material used varies depending on the type of host material, and can be determined according to the characteristics of the host material. The standard for the usage amount of the host material is preferably 50 to 99.999 mass% of the total mass of the light emitting layer material, more preferably 80 to 99.95 mass%, and even more preferably 90 to 99.9 mass%. When the host material is a combination of a hole-transporting host material and an electron-transporting host material, the amount of host material used is the mass of the amount of the hole-transporting host material and the amount of the electron-transporting host material used. The mass ratio of the hole-transporting host material and the electron-transporting host material may be 1:9 to 9:1, preferably 4:6 to 6:4, and more preferably approximately 1:1.

The amount of dopant material used varies depending on the type of dopant material, and can be determined according to the characteristics of the dopant material. The standard for the amount of dopant used is preferably 0.001 to 50 mass% of the total mass of the light-emitting layer material, more preferably 0.05 to 20 mass%, and even more preferably 0.1 to 10 mass%. The above range is preferable because, for example, concentration quenching phenomenon can be prevented.

As the dopant material, an emitting dopant and an assisting dopant may be used. As an assisting dopant material, a thermally activated delayed fluorescent material can be preferably used. In an organic electroluminescent device using an assisting dopant material, it is preferable that the emitting dopant material be used at a low concentration to prevent concentration quenching. It is desirable in terms of efficiency of the thermally activated delayed fluorescence device that the assisting dopant material be used at a high concentration. In addition, in an organic electroluminescent device using a thermally activated delayed fluorescence assisting dopant material, in terms of the efficiency of the thermally activated delayed fluorescence mechanism of the assisting dopant material, the amount of emitting dopant material used is higher than the amount of assisting dopant material used. It is preferable that this concentration is low.

When an assisting dopant material is used, the standards for the usage amounts of the host material, assisting dopant material, and emitting dopant material are 40 to 99% by mass and 59 to 1% by mass, respectively, based on the total mass of the light emitting layer material. and 20 to 0.001 mass%, preferably 60 to 95 mass%, 39 to 5 mass% and 10 to 0.01 mass%, respectively, more preferably 70 to 90 mass%, 29 to 10 mass% and It is 5 to 0.05 mass%.

<Dopant material>

As the dopant material, known compounds can be used, and various materials can be selected depending on the desired luminescent color. Specifically, for example, condensed ring derivatives such as phenanthrene, anthracene, pyrene, tetracene, pentacene, perylene, naphthopyrene, dibenzopyrene, rubrene, and chrysene, benzoxazole derivatives, and benzothiazole. Derivatives, benzoimidazole derivatives, benzotriazole derivatives, oxazole derivatives, oxadiazole derivatives, thiazole derivatives, imidazole derivatives, thiadiazole derivatives, triazole derivatives, pyrazoline derivatives, stilbene derivatives, thiophene derivatives, Tetraphenylbutadiene derivatives, cyclopentadiene derivatives, bistyryl derivatives such as bistyryl anthracene derivatives and distyrylbenzene derivatives (Japanese Patent Application Laid-open No. 1-245087), bistyrylarylene derivatives (Japanese Patent Application Laid-Open No. 2) -247278 Publication), diazindacene derivatives, furan derivatives, benzofuran derivatives, phenylisobenzofuran, dimethylisobenzofuran, di(2-methylphenyl)isobenzofuran, di(2-trifluoromethylphenyl)iso Isobenzofuran derivatives such as benzofuran and phenylisobenzofuran, dibenzofuran derivatives, 7-dialkylaminocoumarin derivatives, 7-piperidinocoumarin derivatives, 7-hydroxycoumarin derivatives, 7-methoxycoumarin derivatives, 7 -Coumarin derivatives such as acetoxycoumarin derivatives, 3-benzothiazolylcoumarin derivatives, 3-benzoimidazolylcoumarin derivatives, and 3-benzooxazolylcoumarin derivatives, dicyanomethylene pyran derivatives, dicyanomethylenethiopyran derivatives, polymethine Derivatives, cyanine derivatives, oxobenzoanthracene derivatives, xanthene derivatives, rhodamine derivatives, fluorescein derivatives, pyrilium derivatives, carbostyryl derivatives, acridine derivatives, oxazine derivatives, phenylene oxide derivatives, quinacridone derivatives , quinazoline derivatives, pyrrolopyridine derivatives, furopyridine derivatives, 1,2,5-thiadiazolopyrene derivatives, pyromethene derivatives, perinone derivatives, pyrrolopyrrole derivatives, squaryllium derivatives, biolanthrone derivatives, phenase Examples include gin derivatives, acridone derivatives, deazaflavin derivatives, fluorene derivatives, and benzofluorene derivatives.

As a dopant material, it is also preferable to use a polycyclic aromatic compound containing boron described in paragraphs 0097 to 0269 of International Publication No. 2015/102118, International Publication No. 2020/162600, and Japanese Patent Application Publication No. 2021-077890.

As a dopant material, a thermally activated delayed phosphor may be used. A thermally activated delayed phosphor is a compound that absorbs heat energy, causes reverse intersystem crossing from the lowest triplet excitation state to the lowest singlet excitation state, and emits delayed fluorescence by radiation deactivation from the lowest singlet excitation state. it means.

In the light-emitting layer, a phosphorescent material may be used as an assisting dopant. For example, Japanese Patent Application Laid-open No. 2006-089398, Japanese Patent Application Laid-Open No. 2006-080419, Japanese Patent Application Laid-Open No. 2005-298483, Japanese Patent Application Laid-Open No. 2005-097263, and Japanese Patent Application Laid-Open No. 2004-111379, Iridium complex described in U.S. Patent Application Publication No. 2019/0051845, etc., or Japanese Patent Application Publication No. 2014-239225, Advanced Materials, 26:7116-7121, NPG Asia Materials 13,53 (2021), Applied Physics Letters, 117 , 253301 (2020), Light-Emitting Diode - An Outlook On the Empirical Features and Its Recent Technological Advancements, Chapter 5. The platinum complex may also be used.

<Host material>

As host materials, condensed ring derivatives such as anthracene and pyrene, which were previously known as light emitters, bistyryl derivatives such as bistyryl anthracene derivatives and distyrylbenzene derivatives, tetraphenylbutadiene derivatives, cyclopentadiene derivatives, fluorene derivatives, Benzofluorene derivatives, N-phenylcarbazole derivatives, carbazonitrile derivatives, etc. can be mentioned.

The lowest triplet excitation energy level (E _T1 ) of the host material is higher than the E T1 of the dopant or assisting dopant with the highest E _T1 in the light-emitting layer from the viewpoint of promoting rather than inhibiting the generation of TADF in the light-emitting _layer . It is preferable that it is high, and specifically, the E _T1 of the host material is preferably higher by 0.01 eV or more, more preferably by 0.03 eV or more, and higher by 0.1 eV or more compared to the E _T1 of the above-mentioned dopant or assisting dopant. It is more desirable than Additionally, E _T1 of the host material is preferably 2.70 eV or more, more preferably 2.73 eV or more, and still more preferably 2.80 eV or more.

A compound with TADF activity may be used as the host material.

There may be one type of host material, or a combination of multiple types may be used. In the case of a plurality of combinations, it is preferable that it is a combination of a hole-transporting host material and an electron-transporting host material.

2-1-6. Electron injection layer and electron transport layer in organic electroluminescent devices

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

The electron injection/transport layer is a layer that injects electrons from the cathode and is responsible for transporting the electrons. It is desirable that the electron injection efficiency is high and the injected electrons are transported efficiently. For this purpose, it is desirable to use a material that has high electron affinity, high electron mobility, excellent stability, and that impurities that become traps are unlikely to be generated during production and use. However, when considering the transport balance of holes and electrons, if it mainly plays a role in efficiently preventing holes from flowing to the cathode without recombining to the anode, it improves luminous efficiency even if the electron transport ability is not very high. The effect is equivalent to that of materials with high electron transport capacity. Therefore, the electron injection/transport layer in the present embodiment may also include a function of a layer that can efficiently prevent the movement of holes.

The material (electron transport material) forming the electron transport layer 106 or the electron injection layer 107 includes compounds conventionally used as electron transport compounds in photoconductive materials, and compounds used in the electron injection layer and electron transport layer of organic EL devices. It can be used by arbitrarily selecting from among known compounds in use. The polycyclic aromatic compound of the present invention represented by formula (1) or formula (2) is preferably used as an electron transport layer material. The polycyclic aromatic compound of the present invention may be used alone as a material to form one electron transport layer, or may be used as a material to form one electron transport layer in combination with other materials described below. Additionally, in addition to the electron transport layer containing the polycyclic aromatic compound of the present invention, an electron injection layer formed of another material or an additional electron transport layer formed of another material may be used.

In addition to the polycyclic aromatic compound of the present invention, the material (electron transport material) forming the electron transport layer 106 or the electron injection layer 107 includes compounds conventionally used as electron transport compounds in photoconductive materials and organic EL devices. It can be used by arbitrarily selecting from among known compounds used in the electron injection layer and electron transport layer.

Materials used in the electron transport layer or electron injection layer include compounds made of an aromatic ring or heteroaromatic ring composed of one or more atoms selected from carbon, hydrogen, oxygen, sulfur, silicon, and phosphorus, pyrrole derivatives and condensed ring derivatives thereof, and It is preferable to contain at least one type selected from metal complexes having electron-accepting nitrogen. Specifically, condensed ring aromatic ring derivatives such as naphthalene and anthracene, styryl aromatic ring derivatives such as 4,4'-bis(diphenylethenyl)biphenyl, perinone derivatives, coumarin derivatives, and naphthalimide derivatives. , quinone derivatives such as anthraquinone and diphenoquinone, phosphine oxide derivatives, arylnitrile derivatives, and indole derivatives. Examples of metal complexes having electron-accepting nitrogen include hydroxyazole complexes such as hydroxyphenyloxazole complex, azomethine complex, tropolone metal complex, flavonol metal complex, and benzoquinoline metal complex. This material can be used alone, but may also be mixed with other materials.

Additionally, specific examples of other electron transfer compounds include pyridine derivatives, naphthalene derivatives, anthracene derivatives, phenanthroline derivatives, perinone derivatives, coumarin derivatives, naphthalimide derivatives, anthraquinone derivatives, diphenoquinone derivatives, and 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 Compounds, gallium complex, pyrazole derivative, perfluorinated phenylene derivative, triazine derivative, pyrazine derivative, benzoquinoline derivative (2,2'-bis(benzo[h]quinolin-2-yl)-9,9' -spirofluorene, etc.), 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(2,2':6',2"-terpyridin-4'-yl)benzene, etc.), naphthyridine derivatives (bis) (1-naphthyl)-4-(1,8-naphthyridin-2-yl)phenylphosphine oxide, etc.), aldazine derivatives, carbazole derivatives, indole derivatives, phosphine oxide derivatives, bistyryl derivatives, etc. I can hear it.

Additionally, a metal complex having an electron-accepting nitrogen can also be used, for example, a quinolinol-based metal complex, a hydroxyazole complex such as a hydroxyphenyloxazole complex, an azomethine complex, a tropolone metal complex, or a flavonol metal complex. and benzoquinoline metal complexes.

The above-mentioned materials can be used alone, but may also be used in combination with other materials.

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

When forming an electron transport layer by combining the polycyclic aromatic compound of the present invention with other materials, the other materials preferably include a quinolinol-based metal complex, a pyrimidine derivative, a triazine derivative, or a benzimidazole derivative. The polycyclic aromatic compound of the present invention and the above other materials may be mixed and used to form one electron transport layer or electron injection layer, or the polycyclic aromatic compound of the present invention and the above other materials may be used separately in adjacent layers. When using the polycyclic aromatic compound of the present invention in combination with other materials in the same layer, it is preferable to combine them with a quinolinol-based metal complex. Electron injection into the light-emitting layer is further promoted, and electron transport properties can be improved.

[Quinolinol-based metal complex]

Examples of quinolinol-based metal complexes include compounds represented by the formula (ETM-13).

In formula (ETM-13), R ¹ to R ⁶ are each independently hydrogen or a substituent, M is Li, Al, Ga, Be or Zn, and n is an integer of 1 to 3.

Specific examples of quinolinol-based metal complexes include 8-quinolinol lithium (Liq), tris(8-quinolinolato)aluminum, tris(4-methyl-8-quinolinolato)aluminum, and tris(5-methyl). -8-quinolinolato) aluminum, tris(3,4-dimethyl-8-quinolinolato) aluminum, tris(4,5-dimethyl-8-quinolinolato) aluminum, tris(4,6- Dimethyl-8-quinolinolato) aluminum, bis(2-methyl-8-quinolinolato)(phenolato) aluminum, bis(2-methyl-8-quinolinolato)(2-methylphenolato) To) Aluminum, bis(2-methyl-8-quinolinolato)(3-methylphenolatto) aluminum, bis(2-methyl-8-quinolinolato)(4-methylphenolatto) aluminum, Bis(2-methyl-8-quinolinolato)(2-phenylphenolato)aluminum, bis(2-methyl-8-quinolinolato)(3-phenylphenolato)aluminum, bis(2- Methyl-8-quinolinolato)(4-phenylphenolato)aluminum, bis(2-methyl-8-quinolinolato)(2,3-dimethylphenolato)aluminum, bis(2-methyl- 8-quinolinolato)(2,6-dimethylphenolato) aluminum, bis(2-methyl-8-quinolinolato)(3,4-dimethylphenolato) aluminum, bis(2-methyl- 8-quinolinolato)(3,5-dimethylphenolato) aluminum, bis(2-methyl-8-quinolinolato)(3,5-di-t-butylphenolato) aluminum, bis( 2-methyl-8-quinolinolatto)(2,6-diphenylphenolatto) aluminum, bis(2-methyl-8-quinolinolato)(2,4,6-triphenylphenolatto) Aluminum, bis(2-methyl-8-quinolinolato)(2,4,6-trimethylphenolato)Aluminum, bis(2-methyl-8-quinolinolato)(2,4,5,6 -Tetramethylphenolato) aluminum, bis(2-methyl-8-quinolinolato)(1-naphtholato) aluminum, bis(2-methyl-8-quinolinolato)(2-naphtholato) ) Aluminum, bis (2,4-dimethyl-8-quinolinolato) (2-phenylphenolato) Aluminum, bis (2,4-dimethyl-8-quinolinolato) (3-phenylphenolato) ) Aluminum, bis (2,4-dimethyl-8-quinolinolato) (4-phenylphenolato) aluminum, bis (2,4-dimethyl-8-quinolinolato) (3,5-dimethylphenolate) Norato) Aluminum, Bis(2,4-dimethyl-8-quinolinolato)(3,5-di-t-butylphenolato) Aluminum, Bis(2-methyl-8-quinolinolato) Aluminum -μ-oxo-bis(2-methyl-8-quinolinolato)aluminum, bis(2,4-dimethyl-8-quinolinolato)aluminum-μ-oxo-bis(2,4-dimethyl-8) -quinolinolato) aluminum, bis(2-methyl-4-ethyl-8-quinolinolato) aluminum-μ-oxo-bis(2-methyl-4-ethyl-8-quinolinolato) aluminum, Bis(2-methyl-4-methoxy-8-quinolinolato)aluminum-μ-oxo-bis(2-methyl-4-methoxy-8-quinolinolato)aluminum, bis(2-methyl- 5-Cyano-8-quinolinolato) aluminum-μ-oxo-bis(2-methyl-5-cyano-8-quinolinolato) aluminum, bis(2-methyl-5-trifluoromethyl -8-quinolinolato)aluminum-μ-oxo-bis(2-methyl-5-trifluoromethyl-8-quinolinolato)aluminum, bis(10-hydroxybenzo[h]quinoline)beryllium, etc. can be mentioned.

<Reducing substances>

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

Preferred reducing substances include alkali metals such as Na (work function 2.36 eV), K (2.28 eV), Rb (2.16 eV), or Cs (1.95 eV), Ca (2.9 eV), and Sr (2.0 eV). alkaline earth metals such as (~2.5 eV) or Ba (copper, 2.52 eV), and materials with a work function of 2.9 eV or less are particularly preferred. Among these, more preferable reducing substances are alkali metals of K, Rb or Cs, even 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 the material forming the electron transport layer or electron injection layer, the luminance of the organic EL device can be improved and its lifespan can be improved. In addition, as a reducing material with a work function of 2.9 eV or less, a combination of two or more alkali metals is also preferable, especially a combination containing Cs, for example, Cs and Na, Cs and K, Cs and Rb, or Cs. A combination of Na and K is preferred. By including Cs, the reducing ability can be efficiently exerted, and by adding it to the material forming the electron transport layer or the electron injection layer, the luminance of the organic EL device can be improved and its lifespan can be improved.

2-1-7. 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 forming the cathode 108 is not particularly limited as long as it is a material that can efficiently inject electrons into the organic layer, but the same material as the material 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 their alloys (magnesium-silver alloy, magnesium-silver alloy) Indium alloys, aluminum-lithium alloys such as lithium fluoride/aluminum, etc.) are preferable. In order to improve device characteristics by increasing electron injection efficiency, alloys containing lithium, sodium, potassium, cesium, calcium, magnesium, or these low work function metals are effective. However, these low work function metals are generally unstable in the atmosphere. To improve this problem, there is a known method of using a highly stable electrode by doping a small amount of lithium, cesium or magnesium into the organic layer, for example. 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.

Furthermore, to protect the electrode, metals such as platinum, gold, silver, copper, iron, tin, aluminum and indium, or alloys using these metals, inorganic substances such as silica, titania and silicon nitride, polyvinyl alcohol, vinyl chloride, and hydrocarbons. Laminating a polymer compound or the like is 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.

2-1-8. Manufacturing method of organic electroluminescent device

Each layer constituting the organic EL device is formed by forming the material constituting each layer into a thin film using methods such as vapor deposition, resistance heating deposition, electron beam deposition, sputtering, molecular stacking, printing, spin coating or casting, and coating methods. By doing this, it can be formed. There is no particular limitation on the film thickness of each layer formed in this way, and it can be set appropriately depending on 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. When thinning a film using a vapor deposition method, the deposition conditions vary depending on the type of material, the target crystal structure and association structure of the film, etc. Deposition conditions are generally boat heating temperature +50~+400℃, vacuum degree 10 ^-6~ 10 ^-3 Pa, deposition speed 0.01~50nm/sec, substrate temperature -150~+300℃, film thickness 2nm~5㎛. It is desirable to set it appropriately within the range.

When applying a direct current voltage to the organic EL device obtained in this way, it can be applied with the anode as + and the cathode as -, and when a voltage of about 2 to 40 V is applied, the transparent or translucent electrode side (anode or cathode) , and both sides) can be observed. Additionally, this organic EL element emits light even when pulse current or alternating current is applied. Additionally, the waveform of the applied alternating current may be arbitrary.

Next, as an example of a method of manufacturing an organic EL device, a method of manufacturing an organic EL device composed of an anode/hole injection layer/hole transport layer/host material and a light emitting layer/electron transport layer/electron injection layer/cathode made of a dopant material will be described. Explain.

<Deposition method>

After producing an anode by forming a thin film of an anode material by a vapor deposition method or the like on a suitable substrate, thin films of a hole injection layer and a hole transport layer are formed on this anode. A host material and a dopant material are co-deposited on this to form a thin film to form a light-emitting layer. An electron transport layer and an electron injection layer are formed on this light-emitting layer, and a thin film made of a cathode material is formed by a vapor deposition method to form a cathode, thereby forming the desired organic material. An EL device is obtained. In addition, when manufacturing the organic EL device described above, it is also possible to reverse the manufacturing order and fabricate the cathode, electron injection layer, electron transport layer, light emitting layer, hole transport layer, hole injection layer, and anode in that order.

<Wet film forming method>

The wet film forming method is performed by preparing a low-molecular-weight compound capable of forming each organic layer of an organic EL device as a liquid composition for forming an organic layer and using it. If there is no suitable organic solvent that dissolves the low-molecular compound, a composition for forming an organic layer can be prepared from a reactive compound obtained by substituting a reactive substituent on the low-molecular compound and polymerized with another monomer or main chain polymer having a soluble function. You may prepare.

The wet film forming method generally forms a coating film by going through an application process of applying a composition for forming an organic layer to a substrate and a drying process of removing a solvent from the applied composition for forming an organic layer. When the polymer compound has a crosslinkable substituent (this is also referred to as a crosslinkable polymer compound), it is further crosslinked through this drying process to form a crosslinked polymer. Depending on the difference in the application process, the method using a spin coater is the spin coat method, the method using the slit coater is the slit coat method, and the method using the plate is gravure, offset, reverse offset, flexo printing, and inkjet printer. The method used is called the inkjet method, and the method of emitting it in the form of a mist is called the spray method. The drying process includes methods such as air drying, heating, and reduced pressure drying. The drying process may be performed only once, or may be performed multiple times using different methods or conditions. Additionally, other methods may be used in combination, such as baking under reduced pressure, for example.

A wet film formation method is a film formation method using a solution, for example, some printing methods (inkjet methods), spin coating methods, cast methods, coating methods, etc. Unlike the vacuum deposition method, the wet film deposition method does not require the use of an expensive vacuum deposition device and can be formed under atmospheric pressure. Additionally, the wet film forming method enables large-area and continuous production, leading to a reduction in manufacturing costs.

On the other hand, when compared to the vacuum deposition method, the wet film deposition method may be difficult to laminate. When producing a laminated film using a wet film forming method, it is necessary to prevent dissolution of the lower layer by the composition of the upper layer, so a composition with controlled solubility, crosslinking of the lower layer, and an orthogonal solvent (solvent that does not dissolve in each other), etc. This is used. However, even if these technologies are used, it is sometimes difficult to use a wet film forming method for application of all films.

Therefore, generally, a method of manufacturing an organic EL device using a wet film deposition method for only a few layers and a vacuum deposition method for the remaining layers is adopted.

For example, the procedure for manufacturing an organic EL device by partially applying a wet film forming method is shown below.

(Procedure 1) Film formation by vacuum deposition of anode

(Procedure 2) Film formation of a composition for forming a hole injection layer containing a hole injection layer material by a wet film forming method

(Procedure 3) Film formation of a composition for forming a hole transport layer containing a hole transport layer material by a wet film forming method

(Procedure 4) Film formation of a composition for forming an emitting layer containing a host material and a dopant material by a wet film forming method

(Procedure 5) Film formation of electron transport layer by vacuum deposition method

(Procedure 6) Film formation of electron injection layer by vacuum deposition method

(Procedure 7) Film formation by vacuum deposition of cathode

By going through this procedure, an organic EL device consisting of 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 is obtained.

Of course, the electron transport layer and the electron injection layer may also be formed by a wet film forming method using a layer forming composition containing the electron transport layer material and the electron injection layer material, respectively. At this time, it is preferable to use means to prevent dissolution of the lower light emitting layer, or to form a film from the cathode side, contrary to the above procedure.

<Other tabernacle methods>

Laser thermal imaging (LITI) can be used to form a film of the composition for forming an organic layer. LITI is a method of heating and depositing a compound attached to a substrate with a laser, and a composition for forming an organic layer can be used as the material applied to the substrate.

<Random process>

Appropriate treatment processes, cleaning processes, and drying processes may be appropriately added before and after each process of film formation. Examples of the treatment process include exposure treatment, plasma surface treatment, ultrasonic treatment, ozone treatment, washing treatment using an appropriate solvent, and heat treatment. Additionally, a series of processes for manufacturing a bank can also be mentioned.

Photolithography technology can be used to produce banks. As bank materials that can be used for photolithography, positive resist materials and negative resist materials can be used. Additionally, patternable printing methods such as inkjet printing, gravure offset printing, reverse offset printing, and screen printing can also be used. In this case, a permanent resist material may be used.

<Composition for forming organic layer used in wet film forming method>

The composition for forming an organic layer is obtained by dissolving a low-molecular compound capable of forming each organic layer of an organic EL device, or a high-molecular compound obtained by polymerizing the low-molecular compound, in an organic solvent. For example, the composition for forming a light-emitting layer includes at least one polycyclic aromatic compound (or a polymer compound thereof) as a dopant material as a first component, at least one host material as a second component, and at least one host material as a third component. Contains a variety of organic solvents. The first component functions as a dopant component of the light-emitting layer obtained from the composition, and the second component functions as a host component of the light-emitting layer. The third component functions as a solvent that dissolves the first and second components in the composition, and upon application, imparts a smooth and uniform surface shape by the controlled evaporation rate of the third component itself.

<Organic solvent>

The composition for forming an organic layer includes at least one type of organic solvent. By controlling the evaporation rate of the organic solvent during film formation, film formability, presence of defects, surface roughness, and smoothness of the coating film can be controlled and improved. Additionally, when forming a film using the inkjet method, the meniscus stability in the pinhole of the inkjet head can be controlled to control and improve ejection properties. Additionally, by controlling the drying rate of the film and the orientation of the derivative molecules, the electrical properties, luminescence properties, efficiency, and lifespan of an organic EL device having an organic layer obtained from the composition for forming the organic layer can be improved.

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

Organic solvents used in the composition for forming an organic layer include alkylbenzene-based solvents, phenyl ether-based solvents, alkyl ether-based solvents, cyclic ketone-based solvents, aliphatic ketone-based solvents, monocyclic ketone-based solvents, and solvents having a diester skeleton. Fluorine-based solvents, etc. can be mentioned. In addition, solvents may be used singly or mixed.

<Arbitrary component>

The composition for forming an organic layer may contain optional components as long as its properties are not impaired. Optional components include binders and surfactants.

<Composition and physical properties of composition for forming organic layer>

The content of each component in the composition for forming an organic layer is determined so that each component in the composition for forming an organic layer has good solubility, storage stability, and film forming properties, good film quality of the coating film obtained from the composition for forming an organic layer, and can be used by the inkjet method. It is determined taking into consideration the viewpoints of good discharge properties when used, good electrical characteristics, luminescence characteristics, efficiency, and lifespan of an organic EL device having an organic layer produced using the composition.

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

2-1-9. Application examples of organic electroluminescent devices

The present invention can also be applied to a display device provided with an organic EL element or a lighting device provided with an organic EL element.

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

Examples of display devices include panel displays such as color flat panel displays, and flexible displays such as flexible color organic electroluminescence (EL) displays (for example, Japanese Patent Application Laid-Open No. 10-335066, See Japanese Patent Publication No. 2003-321546, Japanese Patent Publication No. 2004-281086, etc.). Additionally, examples of display methods include matrix and segment methods. Additionally, the matrix display and segment display may coexist in the same panel.

In a matrix, pixels for display are arranged two-dimensionally, such as in a grid or mosaic, and characters or images are displayed as a set of pixels. The shape and size of the pixel are determined depending on the purpose. For example, for image and text display on computers, monitors, and televisions, square pixels with a side of 300 ㎛ or less are usually used, and in the case of large displays such as display panels, pixels on the order of mm per side are used. I do it. In the case of monochrome display, pixels of the same color can be arranged, but in the case of color display, red, green, and blue pixels are displayed in a row. In this case, there are typically delta types and stripe types. The driving method of this matrix may be either a line-sequential driving method or an active matrix driving method. Line-sequential driving has the advantage of having a simple structure, but when considering operation characteristics, the active matrix method is sometimes superior, so it is necessary to use it separately depending on the application.

In the segment method (type), a pattern is formed to display predetermined information, and a defined area is emitted. Examples include time and temperature displays in digital clocks and thermometers, operating status displays in audio devices and electronic cookers, and panel displays in automobiles.

Examples of lighting devices include lighting devices such as indoor lighting, backlights of liquid crystal display devices, etc. (for example, Japanese Patent Application Laid-Open No. 2003-257621, Japanese Patent Application Laid-Open No. 2003-277741, Japanese Patents (See Public Notice No. 2004-119211, etc.). Backlights are mainly used to improve the visibility of display devices that do not emit light themselves, and are used in liquid crystal displays, clocks, audio devices, automobile panels, displays, and signs. In particular, considering that it is difficult to reduce the thickness of liquid crystal display devices, especially computer-use backlights where thinness is an issue, because 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 being lightweight.

<2-2. other organic device >

The polycyclic aromatic compound according to the present invention can be used in the production of organic field-effect transistors or organic thin-film solar cells in addition to the organic electroluminescent devices described above.

An organic field effect transistor is a transistor that controls current by an electric field generated by voltage input, and is provided with a gate electrode in addition to the source and drain electrodes. It is a transistor that generates an electric field when a voltage is applied to the gate electrode and can control the current by arbitrarily blocking the flow of electrons (or holes) flowing between the source and drain electrodes. Field effect transistors are easier to miniaturize than simple transistors (bipolar transistors), and are often used as elements constituting integrated circuits and the like.

The structure of an organic field-effect transistor is usually such that a source electrode and a drain electrode are provided in contact with an organic semiconductor active layer formed using the polycyclic aromatic compound according to the present invention, and an insulating layer (dielectric layer) in contact with the organic semiconductor active layer is provided between them. It is sufficient as long as the gate electrode is installed. Examples of the device structure include the following structures.

(1) Substrate/gate electrode/insulator layer/source electrode/drain electrode/organic semiconductor active layer

(2)Substrate/gate electrode/insulator layer/organic semiconductor active layer/source electrode/drain electrode

(3) Substrate/organic semiconductor active layer/source electrode/drain electrode/insulator layer/gate electrode

(4)Substrate/source electrode/drain electrode/organic semiconductor active layer/insulator layer/gate electrode

The organic field effect transistor constructed in this way can be applied as a pixel driving switching element of an active matrix driving type liquid crystal monitor or organic light emitting device display.

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

<3.Wavelength conversion material>

Currently, the application of multi-color technology based on color conversion method to liquid crystal monitors, organic EL displays, lighting, etc. is being actively studied. Color conversion refers to converting light emission from a light emitting body into light of a longer wavelength, for example, converting ultraviolet light or blue light into green light or red light emission. By forming a wavelength conversion material with this color conversion function into a film and combining it with a blue light source, for example, it becomes possible to extract the three primary colors of blue, green, and red from the blue light source, that is, to extract white light. . By using a white light source that combines a blue light source and a wavelength conversion film with a color conversion function as a light source unit and combining it with a liquid crystal driving part and a color filter, it is possible to produce a full color display. In addition, if there is no liquid crystal driving part, it can be used as a white light source, for example, it can be applied as a white light source such as LED lighting. Additionally, by using a blue organic EL device as a light source and using it in combination with a wavelength conversion film that converts blue light into green light and red light, it becomes possible to produce a full-color organic EL display without using a metal mask. In addition, by using blue micro LED as a light source in combination with a wavelength conversion film that converts blue light into green light and red light, it becomes possible to produce a low-cost, full-color micro LED display.

The polycyclic aromatic compound of the present invention can be used as this wavelength conversion material. Using the wavelength conversion material containing the polycyclic aromatic compound of the present invention, light from a light source or light-emitting device that generates ultraviolet light or shorter wavelength blue light is transmitted to a display device (a display device or a liquid crystal display device using an organic EL device). It can be converted into blue or green light with high color purity suitable for use in. Adjustment of the converted color can be performed by appropriately selecting the substituent of the polycyclic aromatic compound of the present invention, the binder resin used in the composition for wavelength conversion described later, etc. The wavelength conversion material can be prepared as a composition for wavelength conversion containing the polycyclic aromatic compound of the present invention. Additionally, a wavelength conversion film may be formed using this composition for wavelength conversion.

The composition for wavelength conversion may contain a binder resin, other additives, and a solvent in addition to the polycyclic aromatic compound of the present invention. As the binder resin, for example, those described in paragraphs 0173 to 0176 of International Publication No. 2016/190283 can be used. As other additives, compounds described in paragraphs 0177 to 0181 of International Publication No. 2016/190283 can be used. As the solvent, reference may be made to the description of the solvent contained in the composition for forming the emitting layer.

The wavelength conversion film includes a wavelength conversion layer formed by curing the composition for wavelength conversion. As a method of producing a wavelength conversion layer from a composition for wavelength conversion, a known film forming method may be referred to. The wavelength conversion film may consist only of a wavelength conversion layer formed from a composition containing the polycyclic aromatic compound of the present invention, or another wavelength conversion layer (for example, a wavelength conversion layer that converts blue light into green light or red light, It may also contain a wavelength conversion layer that converts to red light. The wavelength conversion film may further include a barrier layer to prevent the base layer or the color conversion layer from being deteriorated by oxygen, moisture, or heat.

[Example]

Hereinafter, the present invention will be described in more detail through examples, but the present invention is not limited to these.

<Synthesis example>

[Synthesis of 3-ethynyl-2-iodine-1,1'-biphenyl]

According to the above scheme, 3-ethynyl-2-iodine-1,1'-biphenyl was synthesized.

[Synthesis of compound (SM-1)]

Under nitrogen atmosphere, 3-ethynyl-2-iodine-1,1'-biphenyl (1.08g, 3.6mmol), copper(I) iodide (0.229g, 1.2mmol), potassium carbonate (0.249g, 1.8mmol) was dissolved in DMF (N,N-dimethylformamide) (36 mL), stirred at room temperature for 4 hours, and then stirred at 140°C for 4 hours. The reaction solution was cooled to room temperature, passed through a silica gel short pass column (developing solvent: toluene), and the solvent was distilled off under reduced pressure. The obtained crude product was washed with hexane to obtain compound (SM-1) (0.420 g, yield 66%) as a colorless solid.

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

¹ H-NMR (500MHz, CDCl ₃ )δ=6.85(dd, 3H), 7.12(dd, 3H), 7.20(dd, 3H), 7.41-7.49 (m, 9H), 7.60(d, 6H)

[Synthesis of Compound (1-1) and Compound (2-1)]

Into a Schlenk tube containing compound (SM-1) (36.4 mg, 69 μmol) and 2,6-di-tert-butylpyridine (62 μl, 0.28 mmol), 1,2,4-trichlorobenzene (0.69 ml) was added. Then, boron triiodide (27.0 mg, 69 μmol) was added at room temperature under an argon atmosphere. After heating and stirring at 150°C for 16 hours, the reaction solution was cooled to room temperature, and phosphate buffer solution (pH=6.8, 1.5 ml) and saturated aqueous sodium thiosulfate solution (0.69 ml) were added at room temperature. Afterwards, the aqueous layer was extracted with dichloromethane (3.0 ml, 3 times), and the solvent was removed by distillation under reduced pressure. The obtained crude product was washed with hexane and subjected to GPC (eluent: 1,2-dichloroethane) to separate compound (1-1) and compound (2-1), and compound (1-1) (5.10 mg) , yield 14%), and compound (2-1) (3.35 mg, yield 9.5%) were all obtained as red solids.

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

Compound (1-1)

¹ H-NMR (500MHz, (CDCl ₂ ) ₂ ): δ=7.74-7.80 (m, 6H), 7.84 (t, 3H), 8.66(d, 3H), 8.72(d, 3H), 8.77(d, 3H), 8.89(d, 3H)

Compound (2-1)

¹ H-NMR (500MHz, (CDCl ₂ ) ₂ ):δ=7.32 (t, 3H), 7.45 (t, 6H), 7.64(d, 3H), 7.80(d, 3H), 8.36(d, 3H) , 8.46(d, 3H)

[Synthesis of Compound (1-123) and Compound (2-119)]

In the above-mentioned [synthesis of 3-ethynyl-2-iodine-1,1'-biphenyl], 2-(3-ethynyl- 2-iodophenyl)naphthalene was synthesized. Next, in the above-mentioned [synthesis of compound (SM-1)], 3-ethynyl-2-iodo-1,1'-biphenyl is reacted with 2-(3-ethynyl-2-iodophenyl)naphthalene. Compound (SM-2) was synthesized in the same manner except that it was changed to .

Under nitrogen atmosphere, compound (SM-2) (0.725g, 1.0mmol), boron triiodide (0.784g, 2.0mmol), 2,6-di-tert-butylpyridine (0.66ml, 3.0mmol) and 1,2, A flask containing 4-trichlorobenzene (50 ml) was heated and stirred at 150°C for 15 hours. Afterwards, the reaction solution was cooled to room temperature, and phosphate buffer solution (pH = 6.8, 25 ml) and saturated sodium thiosulfate solution (25 ml) were added at room temperature. Afterwards, extraction was performed with dichloromethane (20 ml, 3 times), and the solvent was removed by distillation under reduced pressure. Next, Florisil column chromatography (developing solvent: toluene/hexane = 3/7) was performed on the obtained composition, and the fraction containing the target product was concentrated under reduced pressure. Next, by performing GPC (developing solvent: 1,2-dichloroethane), compound (1-123) (1 mg, 0.15%) and compound (2-119) (41 mg, 6%) were obtained as purple solids. .

Regarding compound (2-119), the structure of the obtained compound was confirmed by NMR measurement.

Compound (2-119)

¹ H-NMR (500MHz, (CDCl ₂ ) ₂ ):δ=7.01 (t, 3H), 7.20 (t, 3H), 7.33(d, 3H), 7.37 (t, 3H), 7.57(d, 3H) , 7.87(d, 3H), 7.94(d, 6H), 8.03(d, 3H)

The production of the target was confirmed by MALDI-TOF-MS (matrix-assisted laser departure ionization time-of-flight mass spectrometry).

Compound (1-123):686 .2219

Compound (2-119):686 .2225

<Manufacture and evaluation of organic EL devices>

Composition of organic EL device

The following organic EL device was manufactured using the polycyclic aromatic compound of the present invention.

<Example 1-1 to Example 1-8, and Comparative Example 1>

The material composition of each layer in the organic EL devices of Examples 1-1 to 1-8 and Comparative Example 1 is shown in Table 1 below.

In Table 1, "HI" is N4,N4'-diphenyl-N4,N4'-bis(9-phenyl-9H-carbazol-3-yl)-[1,1'-biphenyl]-4, 4'-diamine, "HAT-CN" is 1,4,5,8,9,12-hexaazatriphenylene hexacarbonitrile, and "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, and "BH" is , 2-(10-phenylanthracen-9-yl)dibenzo[b,d]furan, and “ET-1” is 9,9'-[(5-(6-(1,1'-biphenyl) )-4-yl)-2-phenylpyrimidin-4-yl)-1,3-phenylene]bis(9H-carbazole), and “ET-2” is 2-ethyl-1-(4-( It is 10-phenylanthracen-9-yl)phenyl)-1H-benzo[d]imidazole. The chemical structure is shown below along with "Liq" and "BD" (compound described in International Publication No. 2015/102118) .

[Comparative Example 1]

A 26 mm x 28 mm x 0.7 mm glass substrate (manufactured by Opto Science Co., Ltd.) made by polishing ITO formed to a thickness of 180 nm by sputtering to 120 nm was used as a transparent support substrate. This transparent support substrate was fixed to the substrate holder of a commercially available evaporation device (manufactured by Showa Vacuum Co., Ltd.), and HI, HAT-CN, HT-1, HT-2, BH, BD, ET-1 and ET- A molybdenum deposition boat each containing 2 and an aluminum nitride deposition boat each containing Liq, LiF, and aluminum were installed.

The following layers are sequentially formed on the ITO film of the transparent support substrate. The vacuum chamber was depressurized to 5×10 ^-4 Pa, and first, HI was heated and deposited to a film thickness of 40 nm. Next, HAT-CN was heated and deposited to a film thickness of 5 nm. Next, HT-1 was deposited to a film thickness of 5 nm. was heated and deposited to a film thickness of 45 nm, and then HT-2 was heated and deposited to a film thickness of 10 nm to form a four-layer hole layer. Next, BH and BD were heated simultaneously and deposited to a film thickness of 25 nm to form a light emitting layer. The deposition rate was adjusted so that the mass ratio of BH and BD was about 97:3. Next, ET-1 was heated and deposited to a film thickness of 5 nm, and then ET-2 and Liq were simultaneously heated and deposited to a film thickness of 25 nm, forming a two-layer electronic layer. The deposition rate was adjusted so that the mass ratio of ET-2 and Liq was approximately 50:50. The deposition rate of each layer was 0.01 to 1 nm/sec. After that, LiF was heated and deposited at a deposition rate of 0.01 to 0.1 nm/sec to a film thickness of 1 nm, and then aluminum was heated and deposited to a film thickness of 100 nm to form a cathode, thereby obtaining an organic EL device.

[Example 1-1 to Example 1-8]

An organic EL device was obtained in the same manner as in Comparative Example 1, except that the compounds shown in Table 1 were used instead of ET-1 or ET-2.

Evaluation of organic EL devices

For the organic EL devices of Examples 1-1 to 1-8 and Comparative Example 1, direct current voltage was applied using the ITO electrode as the anode and the LiF/aluminum electrode as the cathode, and the characteristics when emitting light at 1000 cd/m ² was measured.

The results are shown in Table 2.

Examples 1-1 to 1-8 achieved the same luminance with a lower driving voltage compared to Comparative Example 1.

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

Claims (14)

Polycyclic aromatic compounds represented by formula (1) or formula (2);

In equations (1) and (2),
Ring A, ring B, ring C, ring D, ring E, and ring F are each independently a substituted or unsubstituted aryl ring or a substituted or unsubstituted heteroaryl ring,
Ring A and E may be further bonded through a single bond or linking group, Ring B and F may be further bonded through a single bond or linking group, and Ring C and D may be further bonded through a single bond or linking group,
At least one hydrogen in the structure represented by formula (1) or formula (2) may be substituted with deuterium. According to paragraph 1,
Polycyclic aromatic compounds represented by formula (1X) or formula (2X);

In formula (1X) and formula (2X),
Z is each independently -C(-R ^Z )= or -N=,
R ^Z is each independently hydrogen or a substituent,
Two adjacent ^R
Z=Z may each independently be >NR ^NZ , >O, >C(-R ^CZ ) ₂ , >Si(-R ^IZ ) ₂ , >S, or >Se, and R ^NZ , R ^CZ and R ^IZ are Each is independently hydrogen, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted alkyl, or substituted or unsubstituted cycloalkyl, and two R ^CZ may be bonded to each other to form a ring. Alternatively, two R ^IZ may be combined with each other to form a ring,
The a ring and the e ring may be further bonded through a single bond or linking group, the b ring and f ring may be further bonded through a single bond or linking group, the c ring and the d ring may be further bonded through a single bond or linking group,
At least one hydrogen in the structure represented by formula (1X) or (2X) may be substituted with deuterium. The polyaromatic compound of claim 2, wherein all Z's are each independently -C(-R ^Z )=. The polycyclic aromatic compound according to claim 3, which is represented by any of the following formulas.
A material for an organic device containing the polycyclic aromatic compound according to any one of claims 1 to 4. The material for an organic device according to claim 5, wherein the material for an organic device is a material for an organic electroluminescent element, a material for an organic field-effect transistor, a material for an organic thin-film solar cell, or a material for a wavelength conversion filter. An organic electroluminescent element having a pair of electrodes consisting of an anode and a cathode and an organic layer disposed between the pair of electrodes, wherein the organic layer contains the polycyclic aromatic compound according to any one of claims 1 to 4. The organic electroluminescent device according to claim 7, wherein the organic layer is an electron transport layer. A display or lighting device comprising the organic electroluminescent element according to claim 7. Compounds represented by the following formula (SM);

During the ceremony (SM),
Ring A, ring B, ring C, ring D, ring E, and ring F are each independently a substituted or unsubstituted aryl ring or a substituted or unsubstituted heteroaryl ring,
Ring A and E may be further bonded through a single bond or linking group, Ring B and F may be further bonded through a single bond or linking group, and Ring C and D may be further bonded through a single bond or linking group,
At least one hydrogen in the structure represented by formula (SM) may be substituted with deuterium. 11. The compound according to claim 10, represented by the formula (SM-X);

In formula (SM-X),
Z is each independently -C(-R ^Z )= or -N=,
R ^Z is each independently hydrogen or a substituent,
Two adjacent ^R
Z=Z may each independently be >NR ^NZ , >O, >C(-R ^CZ ) ₂ , >Si(-R ^IZ ) ₂ , >S, or >Se, and R ^NZ , R ^CZ and R ^IZ are Each is independently hydrogen, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted alkyl, or substituted or unsubstituted cycloalkyl, and two R ^CZ are bonded to each other to form a ring. Two R ^IZ may be combined with each other to form a ring,
The a ring and the e ring may be further bonded through a single bond or linking group, the b ring and f ring may be further bonded through a single bond or linking group, and the c ring and d ring may be further bonded through a single bond or linking group,
At least one hydrogen in the structure represented by formula (SM-X) may be substituted with deuterium. 12. The compound of claim 11, wherein all Z's are each independently -C(-R ^Z )= The compound according to claim 12, which is represented by the following formula.
A method for producing a polycyclic aromatic compound according to claim 1, comprising reacting a compound represented by the following formula (SM) with a boronating agent in the presence of a Bronsted base;

During the ceremony (SM),
Ring A, ring B, ring C, ring D, ring E, and ring F are each independently a substituted or unsubstituted aryl ring or a substituted or unsubstituted heteroaryl ring,
Ring A and E may be further bonded through a single bond or linking group, Ring B and F may be further bonded through a single bond or linking group, and Ring C and D may be further bonded through a single bond or linking group,
At least one hydrogen in the structure represented by formula (SM) may be substituted with deuterium.