Polycyclic aromatic compound, material for organic device, organic electroluminescent element, display device, and lighting device

Abstract

Provided are: a polycyclic aromatic compound which can be effectively used as a material for an organic device such as an organic EL element; a material for an organic device; an organic electroluminescent element; a display device; the polycyclic aromatic compound is represented by formula (1); rings A to C are substituted or unsubstituted aryl rings or heteroaryl rings (where at least one of rings A to C contains a quaternary carbon substituent represented by formula (G), Y1 is > B-, X1 and X2 are > O, > S or > Se, at least one hydrogen in formula (1) may be substituted by deuterium, L is a single bond or a linking group such as a phenylene group or a dibenzofuranyl group, any one Zg is a carbon bonded to L, and Z is a carbon bonded to C). And Zg is-N = or-C (-Rg) =, Rg is hydrogen or a substituent group, L1 and L2 are hydrogen, or two L1 and two L2 are respectively bonded with each other to form a single bond or > O. # imgabs0 #

Description

Technical Field

[0001] The present invention relates to a polycyclic aromatic compound and also to an organic device such as an organic electroluminescent element, an organic field effect transistor, and an organic thin film solar cell, as well as a display device and a lighting device using the polycyclic aromatic compound. Background Art

[0002] In the past, display devices using light-emitting elements that perform electroluminescence have been studied in various ways because they can achieve power saving or thinning, and organic electroluminescent elements containing organic materials have been actively studied because they can be easily lightweight or large-scaled. In particular, the development of organic materials having light-emitting properties such as blue or green, which are one of the three primary colors of light, and the development of organic materials having charge transport capabilities including holes, electrons, etc. (having the possibility of becoming semiconductors or superconductors) have been actively studied so far, regardless of whether they are polymer compounds or low molecular weight compounds.

[0003] An organic electroluminescence (EL) element has a structure including a pair of electrodes including an anode and a cathode, and one or more layers disposed between the pair of electrodes and including an organic compound. The layers including the organic compound include a light-emitting layer, a charge transport / injection layer for transporting or injecting charges such as holes and electrons, and various organic materials suitable for these layers have been developed.

[0004] As a light-emitting material for a light-emitting layer, for example, a material obtained by improving an azaborine derivative has been reported (Patent Document 1).

[0005] [Prior art literature]

[0006] [Patent Document]

[0007] [Patent Document 1] International Publication No. 2015 / 102118 Summary of the invention

[0008] [Problems to be solved by the invention]

[0009] As described above, various materials have been developed as materials used in organic EL elements, but in order to increase the selection of materials for organic EL elements, it is desired to develop a material containing a compound different from the previous ones. In particular, a material that can further improve the performance of organic devices such as organic EL elements or a material that improves the manufacturing process is needed.

[0010] An object of the present invention is to provide a novel compound which can be effectively used as a material for an organic device such as an organic EL element.

[0011] [Technical means to solve the problem]

[0012] The inventors have made great efforts to solve the above problems and found that polycyclic aromatic compounds with novel boron-containing skeletons have favorable properties as materials for organic devices. Based on this insight, they have further conducted repeated studies to complete the present invention. That is, the present invention provides the following polycyclic aromatic compounds, and further provides materials for organic devices containing the following polycyclic aromatic compounds.

[0013] <1> A polycyclic aromatic compound represented by formula (1);

[0014] [Chemistry 1]

[0015]

[0016] In formula (1),

[0017] Ring A, Ring B and Ring C are each independently a substituted or unsubstituted aryl ring or a substituted or unsubstituted heteroaryl ring, wherein at least one of Ring A, Ring B and Ring C is a substituted aryl ring or a substituted heteroaryl ring and contains a quaternary carbon substituent represented by formula (G) as a substituent,

[0018] Y 1 For >B-, >P-, >P(=O)-, >P(=S)-, >Al-, >Ga-, >As-, >Si(-R IY )-or>Ge(-R GY )-,

[0019] R IY and R GY are each independently a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted alkyl, or a substituted or unsubstituted cycloalkyl,

[0020] X 1 and X 2 Each independently is >NR NX 、>O、>S、>C(-R CX ) 2 、>Si(-R IX ) 2 or>Se,R NX , R CX and R IX are each independently hydrogen, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted alkyl, or substituted or unsubstituted cycloalkyl, and the two R CX Can bond to each other to form a ring, two R IX Can bond to each other to form a ring,

[0021] R NX , R CX and R IX Each independently may be bonded to at least one of the A ring, the B ring, and the C ring via a linking group or a single bond,

[0022] [Chemistry 2]

[0023]

[0024] In formula (G),

[0025] * indicates the bond position,

[0026] L is a single bond, -O-, -S-, a substituted or unsubstituted alkylene group, a substituted or unsubstituted arylene group, or a substituted or unsubstituted heteroarylene group,

[0027] Any Z g is the carbon bonded to L,

[0028] Other Z g are independently -N= or -C(-R g )=,R g are each independently hydrogen or a substituent,

[0029] Two adjacent R g may be bonded to each other and, together with the carbon atoms to which they are bonded, form a substituted or unsubstituted aryl ring or a substituted or unsubstituted heteroaryl ring,

[0030] L 1 Both are hydrogen, or two L 1 Bond to each other to form single bonds, >O, >NR NL 、>Si(-R IL ) 2 , >S or >Se, L 2 Both are hydrogen, or two L 2 Bond to each other to form single bonds, >O, >NR NL 、>Si(-R IL ) 2 , >S or >Se,

[0031] R NL and R IL are each independently hydrogen, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted alkyl, or substituted or unsubstituted cycloalkyl, and the two R IL Can bond to each other to form a ring,

[0032] At least one of the aryl rings and heteroaryl rings selected from the group consisting of the aryl rings and heteroaryl rings in formula (1) may be condensed with at least one cycloalkane, wherein the cycloalkane may be substituted with at least one substituent, wherein at least one -CH 2 - may be substituted by -O-,

[0033] In formula (1), at least one hydrogen may be substituted with deuterium, and at least one nitrogen may be substituted with nitrogen-15( 15 N) substituted, at least one sulfur may be replaced by sulfur-33( 33 S), sulfur-34 ( 34 S) or sulfur-36( 36 S), at least one oxygen may be replaced by oxygen-17( 17 O) or oxygen-18 ( 18 O) substituted, at least one carbon may be substituted by carbon-13 ( 13 C) substituted, at least one boron may be substituted by boron-11 ( 11 B) Replacement.

[0034] <2> The polycyclic aromatic compound according to <1>, wherein Y 1 is>B-.

[0035] <3> The polycyclic aromatic compound according to <2>, wherein X 1 and X 2 are respectively independently >O, >S or >Se.

[0036] <4> The polycyclic aromatic compound according to any one of <1> to <3>, wherein the other Z g All are -C(-R g )=, any set of two adjacent R g may be bonded to each other and to the carbon atoms to which they are bonded to form a substituted or unsubstituted aryl ring or a substituted or unsubstituted heteroaryl ring, and the other R g All are hydrogen.

[0037] <5> The polycyclic aromatic compound according to any one of <1> to <4>, wherein two L 2 Bonded to each other to form single bonds.

[0038] <6> The polycyclic aromatic compound according to any one of <1> to <5>, wherein L is a single bond.

[0039] <7> The polycyclic aromatic compound according to <6>, which is represented by any of the following formulas.

[0040] [Chemistry 3]

[0041]

[0042] <8> The polycyclic aromatic compound according to any one of <1> to <5>, wherein L is -O-, -S-, a substituted or unsubstituted alkylene group, a substituted or unsubstituted arylene group, or a substituted or unsubstituted heteroarylene group.

[0043] <9> The polycyclic aromatic compound according to <8>, which is represented by any of the following formulas.

[0044] [Chemistry 4]

[0045]

[0046] <10> The polycyclic aromatic compound according to any one of <1> to <8>, wherein at least one of the A ring, the B ring and the C ring contains a substituted or unsubstituted aryl group or a substituted or unsubstituted heteroaryl group as a substituent other than the quaternary carbon substituent.

[0047] <11> A material for an organic device, comprising the polycyclic aromatic compound according to any one of <1> to <10>.

[0048] <12> The material for an organic device according to <11>, which is a material for an electron transport layer or an electron injection layer of an organic electroluminescent element.

[0049] <13> An organic electroluminescent device comprising: a pair of electrodes including an anode and a cathode; and an organic layer disposed between the pair of electrodes and containing the polycyclic aromatic compound according to any one of <1> to <10>.

[0050] <14> The organic electroluminescent element according to <13>, wherein the organic layer is an electron transport layer or an electron injection layer.

[0051] <15> A display device or a lighting device, comprising the organic electroluminescent element according to <13> or <14>.

[0052] [Effects of the Invention]

[0053] According to the present invention, there is provided a novel polycyclic aromatic compound which is effectively used as a material for an organic device such as an organic electroluminescent element. The polycyclic aromatic compound of the present invention can be used to produce an organic device such as an organic electroluminescent element. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] Figure 1 This is a schematic cross-sectional view showing an example of an organic electroluminescent element.

[0055] [Explanation of Symbols]

[0056] 100: Organic electroluminescent element

[0057] 101: Substrate

[0058] 102: Anode

[0059] 103: Hole injection layer

[0060] 104: Hole transport layer

[0061] 105: Luminous layer

[0062] 106: Electron transport layer

[0063] 107: Electron injection layer

[0064] 108: Cathode DETAILED DESCRIPTION

[0065] Hereinafter, the present invention will be described in detail. The description of the constituent elements described below is sometimes 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 represented by "~" refers to the range including the numerical values ​​described before and after "~" as the lower limit and the upper limit. In addition, in this specification, the "hydrogen" in the description of the structural formula refers to "hydrogen atom (H)". Similarly, "carbon atom (C)" is sometimes referred to as "carbon".

[0066] In the present specification, "adjacent groups" refer to two groups respectively bonded to two adjacent atoms (two atoms directly bonded by a covalent bond) in a structural formula.

[0067] In the present specification, "Me" represents a methyl group, "Et" represents an ethyl group, "nBu" represents a normal butyl group, "tBu" represents a tertiary butyl group, "iBu" represents an isobutyl group, "secBu" represents a secondary butyl group, "nPr" represents a normal propyl group, "iPr" represents an isopropyl group, "tAm" represents a tert-amyl group, "2EH" represents a 2-ethylhexyl group, "tOct" represents a tert-octyl group, "Ph" represents a phenyl group, "Mes" represents mesityl (2,4,6-trimethylphenyl), "Ad" represents a 1-adamantyl group, "Tf" represents a trifluoromethanesulfonyl group, "TMS" represents a trimethylsilyl group, and "D" represents a deuterium group.

[0068] In this specification, an organic electroluminescent element may be referred to as an organic EL element.

[0069] In this specification, the chemical structure or substituent is sometimes represented by the carbon number, but the carbon number when the chemical structure is substituted with a substituent, or when the substituent is further substituted with a substituent, etc., refers to the carbon number of the chemical structure or the substituent, and does not refer to the total carbon number of the chemical structure and the substituent, or the total carbon number of the substituent and the substituent. For example, the so-called "substituent B with carbon number Y substituted by substituent A with carbon number X" means that "substituent A with carbon number X" is substituted on "substituent B with carbon number Y", and the carbon number Y is not the total carbon number of substituent A and substituent B. In addition, for example, the so-called "substituent B with carbon number Y substituted by substituent A" means that "substituent A (without carbon number limitation)" is substituted on "substituent B with carbon number Y", and the carbon number Y is not the total carbon number of substituent A and substituent B.

[0070] <Description of Ring and Substituent>

[0071] First, the details of the rings and substituents used in the present specification are described below.

[0072] Examples of the “aryl ring” in the present specification include an aryl ring having 6 to 30 carbon atoms, preferably an aryl ring having 6 to 16 carbon atoms, more preferably an aryl ring having 6 to 12 carbon atoms, and particularly preferably an aryl ring having 6 to 10 carbon atoms.

[0073] Specific examples of the "aryl ring" include a benzene ring that is a monocyclic ring system, a biphenyl ring that is a bicyclic ring system, a naphthalene ring and an indene ring that are a condensed bicyclic ring system, a terphenyl ring (meta-terphenyl, o-terphenyl, p-terphenyl) that is a tricyclic ring system, an acenaphthene ring, fluorene ring, phenanthren ring, anthracene ring that are a condensed tricyclic ring system, a triphenylene ring, a pyrene ring, a tetracene ring, The ring is a perylene ring, a pentacene ring, etc. of a condensed five-ring system. In addition, the fluorene ring, the benzofluorene ring, and the indene ring also include structures in which the fluorene ring, the benzofluorene ring, the cyclopentane ring, etc. are spiro-bonded. In addition, the fluorene ring, the benzofluorene ring, and the indene ring also include rings in which two of the two hydrogen atoms of the methylene group in the structure are replaced by alkyl groups such as methyl groups described later as the first substituent to form dimethylfluorene rings, dimethylbenzofluorene rings, dimethylindene rings, etc.

[0074] As the "heteroaryl ring" in the present specification, for example, a heteroaryl ring having 2 to 30 carbon atoms can be mentioned, preferably a heteroaryl ring having 2 to 25 carbon atoms, more preferably a heteroaryl ring having 2 to 20 carbon atoms, further preferably a heteroaryl ring having 2 to 15 carbon atoms, and particularly preferably a heteroaryl ring having 2 to 10 carbon atoms. In addition, as the "heteroaryl ring", for example, a heterocyclic ring containing 1 to 5 heteroatoms selected from oxygen, sulfur, nitrogen, selenium, phosphorus, and tellurium as ring-constituting atoms other than carbon can be mentioned.

[0075] Specific examples of the "heteroaryl ring" include a pyrrole ring, an oxazole ring, an isoxazole ring, a thiazole ring, an isothiazole ring, an imidazole ring, an oxadiazole ring (such as a furazan ring), a thiadiazole ring, a triazole ring, a tetrazole ring, a pyrazole ring, a pyridine ring, a pyrimidine ring, a pyridazine ring, a pyrazine ring, a triazine ring, an indole ring, an isoindole ring, a 1H-indazole ring, a benzimidazole ring, a benzoxazole ring, a benzothiazole ring, a 1H-benzotriazole ring, a quinoline ring, an isoquinoline ring, a cinnoline ring, a quinazoline ring, a quinoxaline ring, a phthalazine ring, a naphthyridine ring, a purine ring, a pteridine ring, a carbazole ring, an acridine ring, a phenoxathiol ring, a phenoxazine ring, a phenothiazine ring, a phenazine ring, a phenazasiline ring, an indolizine ring, a furan ring, a benzofuran ring, an isobenzofuran ring, a dibenzofuran ring, Thiophene ring, benzothiophene ring, dibenzothiophene ring, thianthrene ring, indolecarbazole ring, benzindolecarbazole ring, dibenzoindolecarbazole ring, naphthobenzofuran ring, dioxin ring, dihydroacridine ring, xanthene ring, thioxanthene ring, dibenzodioxin ring, dioxaborinaphthoanthracene ring (5,9-dioxa-13b-bora-13bH-naphtho[3,2,1-de]anthracene ring, etc.), benzoselenophene ring, dibenzoselenophene ring, azacarbazole ring, azadibenzothiophene ring, azadibenzofuran ring, azadibenzoselenophene ring, azatriphenylene ring, imidazoimidazole ring, indoloindole ring, benzofuranocarbazole ring, benzothiophenocarbazole ring, indenocarbazole ring and selenophenecarbazole ring, spiro[fluorene-9,9'-xanthene] ring, spirobis[siliconfluorene] ring, etc. In addition, among the dihydroacridine ring, xanthene ring and thioxanthene ring, two of the two hydrogen atoms of the methylene group in the structure are preferably substituted with an alkyl group such as a methyl group as described later as the first substituent to form a dimethyldihydroacridine ring, a dimethylxanthene ring, a dimethylthioxanthene ring, etc. In addition, bipyridine ring, phenylpyridine ring, pyridylphenyl ring as a bicyclic ring system, terpyridine ring, bipyridylphenyl ring, pyridylbiphenyl ring as a tricyclic ring system can also be listed as a "heteroaryl ring". In addition, the "heteroaryl ring" also includes a pyran ring.

[0076] In this specification, a substituent may be substituted with a further 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 further substituent or is unsubstituted. In the same sense, it is sometimes referred to as "substitutable". In this specification, the specific substituent at this time may be referred to as a "first substituent" and the further substituent may be referred to as a "second substituent".

[0077] In the present specification, the substituent group Z includes:

[0078] The aryl group may be substituted by at least one group selected from the group consisting of an aryl group, a heteroaryl group, an alkyl group, a cycloalkyl group, a cyano group and a halogen group,

[0079] The heteroaryl group may be substituted by at least one group selected from the group consisting of aryl, heteroaryl, alkyl, cycloalkyl, cyano and halogen.

[0080] The diarylamino group may be substituted by at least one group selected from the group consisting of an aryl group, a heteroaryl group, an alkyl group, a cycloalkyl group, a cyano group and a halogen group, and the two aryl groups in the diarylamino group may be bonded to each other via a linking group.

[0081] The diheteroarylamino group may be substituted by at least one group selected from the group consisting of an aryl group, a heteroaryl group, an alkyl group, a cycloalkyl group, a cyano group and a halogen group, and the two heteroaryl groups in the diheteroarylamino group may be bonded to each other via a linking group.

[0082] The arylheteroarylamino group may be substituted by at least one group selected from the group consisting of an aryl group, a heteroaryl group, an alkyl group, a cycloalkyl group, a cyano group and a halogen group, and the aryl group and the heteroaryl group in the arylheteroarylamino group may be bonded to each other via a linking group.

[0083] The diarylboryl group may be substituted by at least one group selected from the group consisting of an aryl group, a heteroaryl group, an alkyl group, a cycloalkyl group, a cyano group and a halogen group, and the two aryl groups in the diarylboryl group may be bonded via a single bond or a linking group.

[0084] The alkyl group may be substituted by at least one group selected from the group consisting of an aryl group, a heteroaryl group, a cycloalkyl group, a cyano group and a halogen group,

[0085] The cycloalkyl group may be substituted by at least one group selected from the group consisting of an aryl group, a heteroaryl group, an alkyl group, a cycloalkyl group, a cyano group and a halogen group,

[0086] The alkoxy group may be substituted by at least one group selected from the group consisting of an aryl group, a heteroaryl group, a cycloalkyl group, a cyano group and a halogen group,

[0087] The aryloxy group may be substituted by at least one group selected from the group consisting of aryl, heteroaryl, alkyl, cycloalkyl, cyano and halogen.

[0088] Substituted silyl, cyano and halogen.

[0089] The aryl group as the second substituent in each group of the substituent group Z may be further substituted by an aryl group, a heteroaryl group, an alkyl group, a cycloalkyl group, a cyano group or a halogen. Similarly, the heteroaryl group as the second substituent may be substituted by an aryl group, a heteroaryl group, an alkyl group, a cycloalkyl group, a cyano group or a halogen.

[0090] In the present specification, when a "substituent" is referred to, unless otherwise specified, it may be any group selected from the substituent group Z. For example, when a "substituted or unsubstituted" group is substituted, the group may be substituted with at least one group selected from the substituent group Z.

[0091] In the present specification, the "aryl group" is, for example, an aryl group having 6 to 30 carbon atoms, and preferably an aryl group having 6 to 20 carbon atoms, an aryl group having 6 to 16 carbon atoms, an aryl group having 6 to 12 carbon atoms, or an aryl group having 6 to 10 carbon atoms.

[0092] Specific examples of the "aryl group" include a monovalent group obtained by removing one hydrogen atom from the above-mentioned "aryl ring". For example, it is a phenyl group which is a monocyclic ring, a biphenyl group (2-biphenyl, 3-biphenyl, or 4-biphenyl) which is a bicyclic ring, a naphthyl group (1-naphthyl or 2-naphthyl) which is a condensed bicyclic ring, a terphenyl group (m-terphenyl-2'-yl, m-terphenyl-4'-yl, m-terphenyl-5'-yl, o-terphenyl-3'-yl, o-terphenyl-4'-yl, p-terphenyl-2'-yl, m-terphenyl-2-yl, m-terphenyl-3-yl, m-terphenyl-4-yl, o-terphenyl-2-yl, o-terphenyl-3-yl, o-terphenyl-4-yl, p-terphenyl-2-yl, p-terphenyl-3-yl, or p-terphenyl-4-yl) which is a tricyclic ring, a condensed tricyclic acenaphthene group (1-, 3-, 4-, or 5- The invention also includes the following: a 1-, 2-, 3-, 4-, or 9-) group, a phenanthren-(1-, 2-, 3-, 4-, or 9-) group, a tetraphenyl group (5'-phenyl-m-terphenyl-2-yl, 5'-phenyl-m-terphenyl-3-yl, 5'-phenyl-m-terphenyl-4-yl, or m-quaterphenyl group) having a tetracyclic ring system, a triphenylene-(1-, 2-, or 4-) group, a pyrene-(1-, 2-, or 4-) group, or a tetracene-(1-, 2-, or 5-) group having a condensed tetracyclic ring system, or a perylene-(1-, 2-, or 3-) group, or a pentacene-(1-, 2-, 5-, or 6-) group having a condensed pentacyclic ring system. In addition, a monovalent group of spirofluorene and the like can be mentioned.

[0093] In addition, the aryl group serving as the second substituent also includes a structure in which the aryl group is substituted by at least one group selected from the group consisting of aryl groups such as phenyl (specific examples are the groups described above), alkyl groups such as methyl (specific examples are the groups described later), and cycloalkyl groups such as cyclohexyl or adamantyl (specific examples are the groups described later).

[0094] As an example thereof, there can be mentioned a group in which the 9-position of the fluorenyl group as the second substituent is substituted with an aryl group such as a phenyl group, an alkyl group such as a methyl group, or a cycloalkyl group such as a cyclohexyl group or an adamantyl group.

[0095] The “arylene group” is, for example, an arylene group having 6 to 30 carbon atoms, and preferably an arylene group having 6 to 20 carbon atoms, an arylene group having 6 to 16 carbon atoms, an arylene group having 6 to 12 carbon atoms, or an arylene group having 6 to 10 carbon atoms.

[0096] Specific examples of the "arylene group" include a divalent group obtained by removing one hydrogen atom from the above-mentioned "aryl group" (monovalent group).

[0097] The “heteroaryl group” is, for example, a heteroaryl group having 2 to 30 carbon atoms, preferably a heteroaryl group having 2 to 25 carbon atoms, a heteroaryl group having 2 to 20 carbon atoms, a heteroaryl group having 2 to 15 carbon atoms, or a heteroaryl group having 2 to 10 carbon atoms. The “heteroaryl group” contains, in addition to carbon atoms, one or more, preferably one to five heteroatoms selected from oxygen, sulfur, and nitrogen as ring-constituting atoms.

[0098] Specific examples of "heteroaryl" include monovalent groups formed by removing one hydrogen from the "heteroaryl ring". Examples include pyrrolyl, oxazolyl, isoxazolyl, thiazolyl, isothiazolyl, imidazolyl, oxadiazolyl, thiadiazolyl, triazolyl, tetrazolyl, pyrazolyl, pyridyl, pyrimidinyl, pyridazinyl, pyrazinyl, triazinyl, indolyl, isoindolyl, 1H-indazolyl, benzimidazolyl, benzoxazolyl, benzothiazolyl, 1H-benzotriazolyl, quinolyl, isoquinolyl, cinnolinyl, quinazolinyl, quinoxalinyl, phenanthrolinyl, phthalazinyl, naphthyridinyl, purinyl, pteridinyl, carbazolyl, acridinyl, phenoxathiol, phenoxazinyl, phenanthrolinyl, phenanthroline ... Thiazinyl, phenazinyl, phenazasilinyl, indolizinyl, furanyl, benzofuranyl, isobenzofuranyl, dibenzofuranyl, naphthobenzofuranyl, thienyl, benzothienyl, isobenzothienyl, dibenzothienyl, naphthobenzothienyl, a monovalent group of a benzophospholine oxide ring, a monovalent group of a dibenzophospholine oxide ring, furazanyl, thianthrenyl, indolecarbazolyl, benzindolecarbazolyl, dibenzoindolecarbazolyl, imidazolinyl, or oxazolinyl, etc. In addition, a monovalent group of spiro[fluorene-9,9'-xanthene], a monovalent group of spirobis[silafluorene], and a monovalent group of benzoselenophene can be mentioned.

[0099] In addition, the heteroaryl group as the second substituent also includes a structure in which the heteroaryl group is substituted by at least one group selected from the group consisting of aryl groups such as phenyl (specific examples are the groups described above), alkyl groups such as methyl (specific examples are the groups described later), and cycloalkyl groups such as cyclohexyl or adamantyl (specific examples are the groups described later).

[0100] As an example, the 9-position of the carbazolyl group as the second substituent is substituted by an aryl group such as a phenyl group, an alkyl group such as a methyl group, or a cycloalkyl group such as a cyclohexyl group or an adamantyl group. In addition, a nitrogen-containing heteroaryl group such as a pyridyl group, a pyrimidyl group, a triazine group, a carbazolyl group, etc., which is further substituted by a phenyl group or a biphenyl group, is also included in the heteroaryl group as the second substituent.

[0101] The “heteroarylene group” is, for example, a heteroarylene group having 2 to 30 carbon atoms, preferably a heteroarylene group having 2 to 25 carbon atoms, a heteroarylene group having 2 to 20 carbon atoms, a heteroarylene group having 2 to 15 carbon atoms, or a heteroarylene group having 2 to 10 carbon atoms. In addition, the “heteroarylene group” is, for example, a divalent group such as a heterocycle containing 1 to 5 heteroatoms selected from oxygen, sulfur, and nitrogen as ring-constituting atoms in addition to carbon.

[0102] Specific examples of the "heteroarylene group" include a divalent group obtained by removing one hydrogen atom from the above-mentioned "heteroaryl group" (monovalent group).

[0103] The "diarylamino group" is an amino group substituted with two aryl groups, and the description of the above-mentioned "aryl group" can be referred to for details of the aryl group.

[0104] The "diheteroarylamino group" is an amino group substituted with two heteroaryl groups, and the description of the "heteroaryl group" can be referred to for details of the heteroaryl group.

[0105] The "arylheteroarylamino group" is an amino group substituted with an aryl group or a heteroaryl group, and the description of the above-mentioned "aryl group" and "heteroaryl group" can be cited for the details of the above-mentioned aryl group and heteroaryl group.

[0106] The two aryl groups in the diarylamino group as the first substituent may be bonded to each other via a linking group, the two heteroaryl groups in the diheteroarylamino group as the first substituent may be bonded to each other via a linking group, and the aryl and heteroaryl groups in the arylheteroarylamino group as the first substituent may be bonded to each other via a linking group. Here, the description of "bonding via a linking group" is as shown below, for example, it means that the two phenyl groups of the diphenylamino group form a bond through a linking group. In addition, the description is also applicable to the diheteroarylamino group and the arylheteroarylamino group formed by aryl or heteroaryl groups.

[0107] [Chemistry 5]

[0108]

[0109] (* indicates the bond position)

[0110] Specific examples of the linking group include: >O, >NR X 、>C(-R X ) 2 、-C(-R X )=C(-R X )-、>Si(-R X ) 2 ,>S,>CO,>CS,>SO,>SO 2 、>SeO、>SeO 2 、>PO、>B(-R X) and >Se. R X are independently alkyl, cycloalkyl, aryl, or heteroaryl, which may be substituted by alkyl, cycloalkyl, aryl, or heteroaryl. X ) 2 、-C(-R X )=C(-R X )-、>Si(-R X ) 2 Two R's X Can be linked to the group X via a single bond or Y bond to each other to form a ring. Y , can be listed as >O, >NR Y 、>C(-R Y ) 2 、>Si(-R Y ) 2 ,>S,>CO,>CS,>SO,>SO 2 , and>Se,R Y are independently alkyl, cycloalkyl, aryl or heteroaryl, which may be substituted by alkyl, cycloalkyl, aryl or heteroaryl. Y is>C(-R Y ) 2 and>Si(-R Y ) 2 In the case of two R Y The alkylene group may be substituted with an alkylene group. 2X Replacement, R 2X are independently alkyl, cycloalkyl, substituted silyl, aryl and heteroaryl, which may be substituted by alkyl, cycloalkyl, substituted silyl or aryl. X )=(CR X )-The two Rs in X They may be bonded to each other and form an aryl ring (such as a benzene ring) or a heteroaryl ring together with these bonded C=C. X )=(CR X )- can be an arylene group (such as 1,2-phenylene) or a heteroarylene group.

[0111] In addition, when simply describing “diarylamino”, “diheteroarylamino” or “arylheteroarylamino” in the present specification, unless otherwise specified, descriptions such as “two aryl groups in the diarylamino group may be bonded to each other via a linking group”, “two heteroaryl groups in the diheteroarylamino group may be bonded to each other via a linking group” and “the aryl and heteroaryl groups in the arylheteroarylamino group may be bonded to each other via a linking group” are respectively added.

[0112] The "diarylboryl group" is a boron group substituted with two aryl groups. The details of the aryl group can be referred to the description of the "aryl group". In addition, the two aryl groups can be linked by a single bond or a linking group (for example, -CH=CH-, -CR=CR-, -C≡C-, >NR, >O, >S, >C=O, >C=S, >S=O, >S(=O) 2 、>Se(=O)、>Se(=O) 2 ,>P(=O),>B(-R),>C(-R) 2 、>Si(-R) 2 Here, the R of -CR=CR-, >R of NR, >R of B(-R), >C(-R) 2 R, and R>Si(-R) is aryl, heteroaryl, diarylamino, alkyl, alkenyl, alkynyl, cycloalkyl, alkoxy, or aryloxy, and at least one hydrogen in the R can be further replaced by aryl, heteroaryl, alkyl, alkenyl, alkynyl, or cycloalkyl. In addition, two adjacent Rs can be bonded to each other to form a ring, and form a cycloalkylene, arylene, and heteroarylene. For the details of the substituents listed here, the descriptions of "aryl", "arylene", "heteroaryl", "heteroarylene", and "diarylamino" described above, and the descriptions of "alkyl", "alkenyl", "alkynyl", "cycloalkyl", "cycloalkylene", "alkoxy", and "aryloxy" described later can be cited. In addition, in this specification, when it is recorded only as "diarylboryl", as long as there is no special description, it is assumed that the description of "the two aryl groups of diarylboryl can be bonded to each other via a single bond or a linking group" is added.

[0113] "Alkyl" can be any of straight chain and branched chain, for example, a straight chain alkyl group with 1 to 24 carbon atoms or a branched chain alkyl group with 3 to 24 carbon atoms, preferably an alkyl group with 1 to 18 carbon atoms (branched chain alkyl group with 3 to 18 carbon atoms), an alkyl group with 1 to 12 carbon atoms (branched chain alkyl group with 3 to 12 carbon atoms), an alkyl group with 1 to 6 carbon atoms (branched chain alkyl group with 3 to 6 carbon atoms), an alkyl group with 1 to 5 carbon atoms (branched chain alkyl group with 3 to 5 carbon atoms), an alkyl group with 1 to 4 carbon atoms (branched chain alkyl group with 3 to 4 carbon atoms), etc.

[0114] Specific examples of “alkyl” include 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, sec-butyl, tert-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-dimethylbutyl, 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, tert-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-icosyl.

[0115] The "alkylene group" is a divalent group obtained by removing any hydrogen atom from an "alkyl group", and examples thereof include a methylene group, an ethylene group, and a propylene group.

[0116] Regarding the "alkenyl group", please refer to the description of the "alkyl group". It is a group in which the CC single bond in the structure of the "alkyl group" is replaced by a C=C double bond, and also includes a group in which not only one but more than two single bonds are replaced by double bonds (also called a diene group or a triene group).

[0117] The "alkenylene group" is a divalent group obtained by removing any hydrogen atom of an "alkenyl group", and examples thereof include a vinylene group.

[0118] Regarding the “alkynyl group”, reference may be made to the description of the “alkyl group”, which is a group in which the C-C single bond in the structure of the “alkyl group” is replaced by a C≡C triple bond, and also includes a group in which not only one but two or more single bonds are replaced by triple bonds (also called a di-alkynyl group or a tri-alkynyl group).

[0119] The “cycloalkyl group” is, for example, a cycloalkyl group having 3 to 24 carbon atoms, preferably a cycloalkyl group having 3 to 20 carbon atoms, a cycloalkyl group having 3 to 16 carbon atoms, a cycloalkyl group having 3 to 14 carbon atoms, a cycloalkyl group having 3 to 12 carbon atoms, a cycloalkyl group having 5 to 10 carbon atoms, a cycloalkyl group having 5 to 8 carbon atoms, a cycloalkyl group having 5 to 6 carbon atoms, or a cycloalkyl group having 5 carbon atoms.

[0120] Specific examples of "cycloalkyl" include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl, or alkyl (especially methyl) substituents having 1 to 5 carbon atoms or 1 to 4 carbon atoms, 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, bicyclo[2.2.1]heptyl (norbornyl), bicyclo[2.2.2]octyl, adamantyl, diadamantyl, decahydronaphthyl, or decahydroazulyl.

[0121] The “cycloalkylene group” is, for example, a cycloalkylene group having 3 to 24 carbon atoms, preferably a cycloalkylene group having 3 to 20 carbon atoms, a cycloalkylene group having 3 to 16 carbon atoms, a cycloalkylene group having 3 to 14 carbon atoms, a cycloalkylene group having 3 to 12 carbon atoms, a cycloalkylene group having 5 to 10 carbon atoms, a cycloalkylene group having 5 to 8 carbon atoms, a cycloalkylene group having 5 to 6 carbon atoms, or a cycloalkylene group having 5 carbon atoms.

[0122] Specific examples of the "cycloalkylene group" include a structure in which one hydrogen atom is removed from the above-mentioned "cycloalkyl group" (monovalent group) to give a divalent group.

[0123] The "cycloalkenyl group" can be exemplified by a group having a structure in which at least one single bond between two carbon atoms in the "cycloalkyl group" becomes a double bond (e.g., -CH 2 -CH 2 - is substituted with -CH=CH-), and is not equivalent to an aryl group. Specific examples thereof include 1-cyclohexenyl and 1-cyclopentenyl.

[0124] The "alkoxy group" is a group represented by "Alk-O-(Alk is an alkyl group)", and the description of the "alkyl group" can be cited for details of the alkyl group.

[0125] The "aryloxy group" is a group represented by "Ar-O-(Ar is an aryl group)", and the description of the "aryl group" can be cited for details of the aryl group.

[0126] The “substituted silyl group” is, for example, a silyl group substituted with at least one of an aryl group, an alkyl group, and a cycloalkyl group, and is preferably a triarylsilyl group, a trialkylsilyl group, a tricycloalkylsilyl group, a dialkylcycloalkylsilyl group, or an alkyldicycloalkylsilyl group.

[0127] The "triarylsilyl group" is a silyl group substituted with three aryl groups, and the description of the "aryl group" can be cited for details of the aryl groups.

[0128] Specific examples of the “triarylsilyl group” include triphenylsilyl, diphenylmononaphthylsilyl, monophenyldinaphthylsilyl, and trinaphthylsilyl groups.

[0129] The “trialkylsilyl group” is a silyl group substituted with three alkyl groups, and the description of the “alkyl group” mentioned above can be referred to for details of the alkyl groups.

[0130] Specific examples of “trialkylsilyl” include trimethylsilyl, triethylsilyl, tri-n-propylsilyl, triisopropylsilyl, tri-n-butylsilyl, triisobutylsilyl, tri-sec-butylsilyl, tri-tert-butylsilyl, ethyldimethylsilyl, n-propyldimethylsilyl, isopropyldimethylsilyl, n-butyldimethylsilyl, isobutyldimethylsilyl, sec-butyldimethylsilyl, tert-butyldimethylsilyl, methyldiethylsilyl, n-propyldimethylsilyl, tert-butyldiethylsilyl, methyldi-n-propylsilyl, ethyldi-n-propylsilyl, n-butyldi-n-propylsilyl, sec-butyldi-n-propylsilyl, tert-butyldi-n-propylsilyl, methyldiisopropylsilyl, ethyldiisopropylsilyl, n-butyldiisopropylsilyl, sec-butyldiisopropylsilyl, or tert-butyldiisopropylsilyl.

[0131] The "tricycloalkylsilyl group" is a silyl group substituted with three cycloalkyl groups, and the description of the "cycloalkyl group" mentioned above can be cited for the details of the cycloalkyl group.

[0132] Specific examples of the “tricycloalkylsilyl group” include tricyclopentylsilyl and tricyclohexylsilyl groups.

[0133] The "dialkylcycloalkylsilyl group" is a silyl group substituted with two alkyl groups and one cycloalkyl group, and the description of the "alkyl group" and the "cycloalkyl group" can be cited for details of the alkyl group and the cycloalkyl group.

[0134] The "alkyldicycloalkylsilyl group" is a silyl group substituted with one alkyl group and two cycloalkyl groups, and the description of the "alkyl group" and the "cycloalkyl group" can be cited for details of the alkyl group and the cycloalkyl group.

[0135] The "halogen" is fluorine, chlorine, bromine or iodine, preferably fluorine, chlorine or bromine, more preferably fluorine or chlorine, further preferably fluorine.

[0136] <When two groups bonded to the same atom are bonded to each other>

[0137] In the present specification, when two groups bonded to the same atom are said to be bonded to each other to form a ring, they may be bonded via a single bond or a linking group (these are also collectively referred to as a linking group). Examples of the linking group include -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)-, -C(=S)-, -S(=O)-, -S(=O) 2 -, -Se(=O)-, -Se(=O) 2 -, -P(=O)-, -B(-R)-, -Si(-R) 2 - or -Se-, for example, the following structures can be cited. In addition, R, -CR 2 -CR 2 -R, -CR=CR-R, -N(-R)-R, -C(-R) 2 -R, -B(-R)-R and -Si(-R) 2 -R are independently hydrogen, aryl which may be substituted by alkyl or cycloalkyl, heteroaryl which may be substituted by alkyl or cycloalkyl, alkyl which may be substituted by cycloalkyl, alkenyl which may be substituted by alkyl or cycloalkyl, alkynyl which may be substituted by alkyl or cycloalkyl, or cycloalkyl which may be substituted by alkyl or cycloalkyl. In addition, two adjacent R may be bonded to each other to form a ring, and may form a cycloalkylene, arylene, or heteroarylene.

[0138] [Chemistry 6]

[0139]

[0140] As the bonding group, a single bond, -CR=CR-, -N(-R)-, -O-, -S-, -C(-R)- as a linking group are preferred. 2 -、-Si(-R) 2 -, and -Se-, more preferably a single bond, -CR=CR-, -N(-R)-, -O-, -S-, and -C(-R)- as a linking group 2 -, more preferably a single bond, -CR=CR-, -N(-R)-, -O-, and -S- as a linking group, and most preferably a single bond.

[0141] The position at which the two Rs are bonded via a bonding group is not particularly limited as long as it is a position at which bonding is possible, but it is preferred that the two Rs are bonded at the most adjacent position. For example, when the two groups are phenyl groups, it is preferred that the two Rs are bonded to each other at the ortho position (position 2) based on the bonding position (position 1) of "C" or "Si" in the phenyl group (refer to the structural formula).

[0142] 1. Polycyclic aromatic compounds

[0143] <Description of the overall structure of polycyclic aromatic compounds>

[0144] The polycyclic aromatic compound of the present invention is represented by formula (1).

[0145] [Chemistry 7]

[0146]

[0147] In formula (1),

[0148] The A ring, the B ring and the C ring are each independently a substituted or unsubstituted aryl ring or a substituted or unsubstituted heteroaryl ring, wherein at least one of the A ring, the B ring and the C ring is a substituted aryl ring or a substituted heteroaryl ring and contains a quaternary carbon substituent as a substituent.

[0149] Regarding polycyclic aromatic compounds having a boron-containing skeleton, it has been found that they have a large highest occupied molecular orbital (HOMO)-lowest unoccupied molecular orbital (LUMO) gap (band gap Eg in the film) and a large electron mobility. However, there is a problem that the glass transition temperature Tg is small and the characteristics are reduced when the film is formed at a practical temperature. Therefore, by introducing a substituent containing a quaternary carbon, it was found that while maintaining a large Eg and electron mobility, a Tg above the practical Tg was maintained. Due to these characteristics, the polycyclic aromatic compound represented by formula (1) is suitable for use in an electron transport layer.

[0150] <Description of Ring Structure in Polycyclic Aromatic Compounds>

[0151] In formula (1), "A", "B", and "C" in the circles are symbols indicating the ring structures represented by the circles. The structure represented by formula (1) has a structure using Y 1 , X 1 and X 2 A structure in which at least three aromatic rings among the A ring, the B ring, and the C ring are linked to form a ring structure. The formed ring structure is a condensed ring structure composed of at least five rings.

[0152] Ring A forms a trivalent group having bonds on three consecutive atoms (preferably carbon) on the aryl ring or heteroaryl ring in its structure. 1 , X 1 and X 2 Bond. The ring in which the atoms having the three bonding bonds are set as the ring-constituting atoms in ring A is preferably a 5-membered ring or a 6-membered ring. The ring may be further condensed with other rings. Examples of 6-membered rings include benzene rings. Examples of 6-membered rings further condensed with other rings include: naphthalene ring, anthracene ring, quinoline ring, isoquinoline ring, quinazoline ring, dibenzofuran ring, dibenzothiophene ring, carbazole ring, etc. Examples of 5-membered rings include: furan ring, thiophene ring, pyrrole ring, thiazole ring, etc. Examples of 5-membered rings further condensed with other rings include: benzofuran ring, benzothiophene ring, indole ring, etc. In addition, as a condensed ring, an indene ring may also be mentioned.

[0153] The aryl ring or heteroaryl ring in the A ring is preferably a benzene ring.

[0154] Ring B and ring C each form a divalent group having a bond on two atoms (preferably carbon) adjacent to each other on the aryl ring or heteroaryl ring in the structure. 1 , and X 1 or X 2 Bond. In each ring of the B ring and the C ring, the ring in which the atoms having the two bonding bonds are set as the ring-constituting atoms is preferably a 5-membered ring or a 6-membered ring. The ring may be further condensed with other rings. Examples of 6-membered rings include benzene rings, pyridine rings, etc. Examples of 6-membered rings that are further condensed with other rings include: naphthalene rings, quinoline rings, benzofuran rings, benzothiophene rings, indole rings, benzoselenophene rings, dibenzofuran rings, dibenzothiophene rings, carbazole rings, dibenzoselenophene rings, etc. Examples of 5-membered rings include: furan rings, thiophene rings, pyrrole rings, thiazole rings, selenophene rings, etc. Examples of 5-membered rings that are further condensed with other rings include: benzofuran rings, benzothiophene rings, indole rings, benzoselenophene rings, etc. In addition, as condensed rings, indene rings may also be mentioned.

[0155] The aryl ring or heteroaryl ring in the B ring and the C ring is preferably a benzene ring, a furan ring, a thiophene ring, a pyrrole ring, a thiazole ring, an indene ring, a benzofuran ring, a benzothiophene ring, a benzoselenophene ring or an indole ring, and more preferably a benzene ring.

[0156] In formula (1), in the substituted or unsubstituted aryl ring or substituted or unsubstituted heteroaryl ring in the A ring, the B ring and the C ring, as the substituent mentioned in "substituted or unsubstituted (substituted or unsubstituted)", in addition to the substituent selected from the substituent group Z, there can be exemplified a substituted or unsubstituted alkenyl group, a substituted or unsubstituted arylthio group, preferably a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, a triarylsilyl group or a cyano group. As the second substituent, a methyl group, a trifluoromethyl group, a halogen group, a cyano group and the like are also preferred.

[0157] From the viewpoint of synthesis and sublimation properties, the aryl ring or heteroaryl ring in the A ring, the B ring, and the C ring preferably has no substituent other than the substituent containing a quaternary carbon. In addition, from the viewpoint of increasing Tg, the aryl ring or heteroaryl ring in the A ring, the B ring, and the C ring preferably has at least one of a substituted or unsubstituted aryl group and a substituted or unsubstituted heteroaryl group in addition to the substituent containing a quaternary carbon, and more preferably the aryl group and the heteroaryl group are unsubstituted.

[0158] <Explanation of quaternary carbon substituent>

[0159] In the present specification, "quaternary carbon substituent" refers to a quaternary carbon substituent that includes at least one quaternary carbon and at least four aromatic rings, and the four bonds of the quaternary carbon are all bonded to the ring-constituting atoms of the aromatic ring. Here, the aromatic ring includes an aryl ring and a heteroaryl ring, and the quaternary carbon is directly bonded to the ring-constituting atoms of the aromatic ring. In addition, here, the aromatic ring refers to a monocyclic ring. The four bonds of the quaternary carbon can be bonded to different aromatic rings respectively. Two or more of the four aromatic rings can be bonded to each other at different positions, or can be condensed with each other.

[0160] The number of quaternary carbon substituents in formula (1) is not particularly limited, and is preferably 1 or 2, and more preferably 1. A quaternary carbon substituent may be included in any of rings A to C. When the aryl ring or heteroaryl ring in rings A to C is a benzene ring, the quaternary carbon substituent is preferably in Y 1 , X 1 or X 2 The counterpoint of any one of them.

[0161] Specifically, the quaternary carbon substituent may be a group represented by the formula (G).

[0162] [Chemistry 8]

[0163]

[0164] In formula (G), * represents a bonding position.

[0165] In formula (G), L is a single bond or a linking group. Examples of the linking group include -O-, -S-, a substituted or unsubstituted alkylene group, a substituted or unsubstituted arylene group, or a substituted or unsubstituted heteroarylene group. As L, a single bond, a phenylene group (1,2-phenylene group, 1,3-phenylene group, or 1,4-phenylene group) or a dibenzofuranyl group (3,7-dibenzofuranyl group, 2,8-dibenzofuranyl group, or 2,4-dibenzofuranyl group, etc.) is preferred.

[0166] In formula (G), any Z g is the carbon bonded to L.

[0167] Z as a carbon bonded to L g The position of is not particularly limited, and may be any of the following positions 1 to 8. In addition, depending on the structure of formula (G), 1 and 8, 2 and 7, 3 and 6, and 4 and 5 may be equivalent to each other. Z as a carbon bonded to L g The position is preferably the following position 2 or position 7.

[0168] [Chemistry 9]

[0169]

[0170] In formula (G), other Z than the above g are independently -N= or -C(-R g )=. Z for -N= g In each monocyclic ring in formula (G), the number of Z is preferably 0 to 2, more preferably 0 to 1, and even more preferably 0. g Preferably, both are -C(-R g )=.

[0171] R g are independently hydrogen or a substituent, and two adjacent R g They may be bonded to each other and, together with the carbon atoms to which they are bonded, form a substituted or unsubstituted aryl ring or a substituted or unsubstituted heteroaryl ring.

[0172] About R gThe substituents of include substituted or unsubstituted aryl or substituted or unsubstituted heteroaryl, substituted or unsubstituted diarylamino, substituted or unsubstituted diheteroarylamino, substituted or unsubstituted arylheteroarylamino, substituted or unsubstituted diarylboryl, substituted or unsubstituted alkyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkoxy, substituted or unsubstituted aryloxy, substituted or unsubstituted arylthio, substituted silyl, cyano and halogen. As the substituent, preferably substituted or unsubstituted aryl or substituted or unsubstituted heteroaryl, most preferably phenyl.

[0173] R g It is preferably hydrogen or a hydrogen atom which is adjacent to R g Bond. g Both may be hydrogen.

[0174] Two adjacent R g The two R bonded to each other may form a substituted or unsubstituted aryl ring or a substituted or unsubstituted heteroaryl ring together with the carbon atoms to which they are bonded. Examples of the aryl ring or heteroaryl ring formed include a benzene ring. g Together with the bonded ring, a naphthalene ring is formed. The formed benzene ring is preferably unsubstituted.

[0175] In formula (G), L 1 Both are hydrogen, or two L 1 Bond to each other to form single bonds, >O, >NR NL 、>Si(-R IL ) 2 , >S or >Se. In addition, L 2 Both are hydrogen, or two L 2 Bond to each other to form single bonds, >O, >NR NL 、>Si(-R IL ) 2 ,>S or>Se.

[0176] R NL and R IL are each independently hydrogen, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted alkyl, or substituted or unsubstituted cycloalkyl, and the two R IL They can bond with each other to form a ring. NL It is preferably a substituted or unsubstituted aryl group or a substituted or unsubstituted heteroaryl group, and more preferably a substituted or unsubstituted phenyl group. IL Preferred is a substituted or unsubstituted aryl group or a substituted or unsubstituted alkyl group, and more preferred is a phenyl group or a methyl group.

[0177] In formula (G), preferably two L 2 Bond to each other to form single bonds, >O, >NR NL 、>Si(-R IL ) 2 , >S or >Se. In this case, it is more preferable to have two L 2 It is also preferred that the two L 2 While the two L are bonded to each other 1 Bond to each other to form single bonds, >O, >NR NL 、>Si(-R IL ) 2 , >S or >Se. In this case, it is more preferable to have two L 1 A single bond, >O or >S is formed.

[0178] An example of the group represented by formula (G) includes a group represented by formula (G-1).

[0179] [Chemistry 10]

[0180]

[0181] In formula (G-1), * indicates the bonding position, L, L 1 , Z g With L, L in formula (G) 1 , Z g They have the same meaning respectively.

[0182] Preferred examples of the group represented by formula (G-1) include groups represented by any of the following formulae.

[0183] [Chemistry 11]

[0184]

[0185] [Chemistry 12]

[0186]

[0187] In the above formula, * indicates the bonding position, L, L 1 , R g With L, L in formula (G) 1 , R g They have the same meaning respectively.

[0188] Among the above, a group represented by formula (G-1-2) or formula (G-1-3) is preferred, and a group represented by formula (G-1-3) is more preferred.

[0189] Specific examples of the group represented by formula (G) are shown below. In each specific example, * represents a bonding position.

[0190] [Chemistry 13]

[0191]

[0192] [Chemistry 14]

[0193]

[0194] [Chemistry 15]

[0195]

[0196] [Chemistry 16]

[0197]

[0198] <Y 1 >

[0199] In formula (1), Y 1 For >B-, >P-, >P(=O)-, >P(=S)-, >Al-, >Ga-, >As-, >Si(-R IY )-or>Ge(-R GY )-. R IY and R GY are each independently a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted alkyl, or a substituted or unsubstituted cycloalkyl. IY and R GY , particularly preferably an aryl group having 6 to 10 carbon atoms (e.g., phenyl, naphthyl, etc.), an alkyl group having 1 to 5 carbon atoms (e.g., methyl, ethyl, etc.), or a cycloalkyl group having 5 to 10 carbon atoms (preferably cyclohexyl or adamantyl).

[0200] From the perspective of electron transport, Y 1 It is preferably >B-, >P(=O)- or >P(=S)-, and more preferably >B-.

[0201] <X 1 and X 2 >

[0202] X in formula (1) 1 and X 2 Each independently is >NR NX 、>O、>S、>C(-R CX ) 2 、>Si(-R IX ) 2 Or>Se.

[0203] R CXare each independently hydrogen, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted alkyl, or substituted or unsubstituted cycloalkyl, and the two R CX They can bond with each other to form a ring. CX Preferably it is methyl or phenyl. IX are each independently hydrogen, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted alkyl, or substituted or unsubstituted cycloalkyl, and the two R IX They may bond with each other to form a ring.

[0204] R NX is hydrogen, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted alkyl, or substituted or unsubstituted cycloalkyl, preferably substituted or unsubstituted aryl or substituted or unsubstituted heteroaryl.

[0205] From the perspective of electron transport, X 1 and X 2 They are each independently preferably >O, >S or >Se, and are all more preferably >O.

[0206] <Cycloalkane condensation>

[0207] At least one of the aryl rings and heteroaryl rings in the polycyclic aromatic compound represented by formula (1) may be condensed with at least one cycloalkane. The same is true for the polycyclic aromatic compound represented by formula (1A) described below, and the following description is also applicable to the polycyclic aromatic compound represented by formula (1A).

[0208] The cycloalkane may be a cycloalkane having 3 to 24 carbon atoms. At least one hydrogen atom in the cycloalkane may be substituted by an aryl group having 6 to 30 carbon atoms, a heteroaryl group having 2 to 30 carbon atoms, an alkyl group having 1 to 24 carbon atoms, or a cycloalkyl group having 3 to 24 carbon atoms. 2 - may be substituted by -O-.

[0209] The cycloalkane is preferably a cycloalkane having 3 to 20 carbon atoms, wherein at least one hydrogen in the cycloalkane may be substituted by an aryl group having 6 to 16 carbon atoms, a heteroaryl group having 2 to 22 carbon atoms, an alkyl group having 1 to 12 carbon atoms, or a cycloalkyl group having 3 to 16 carbon atoms.

[0210] Examples of the “cycloalkane” include cycloalkanes having 3 to 24 carbon atoms, cycloalkanes having 3 to 20 carbon atoms, cycloalkanes having 3 to 16 carbon atoms, cycloalkanes having 3 to 14 carbon atoms, cycloalkanes having 5 to 10 carbon atoms, cycloalkanes having 5 to 8 carbon atoms, cycloalkanes having 5 to 6 carbon atoms, and cycloalkanes having 5 carbon atoms.

[0211] Specific examples of cycloalkanes include cyclopropane, cyclobutane, cyclopentane, cyclohexane, cycloheptane, cyclooctane, cyclononane, cyclodecane, norbornane (bicyclo[2.2.1]heptane), bicyclo[1.1.0]butane, bicyclo[1.1.1]pentane, bicyclo[2.1.0]pentane, bicyclo[2.1.1]hexane, bicyclo[3.1.0]hexane, bicyclo[2.2.2]octane, adamantane, diadamantane, decahydronaphthalene and decahydroazulene, and alkyl (especially methyl)-substituted, halogen (especially fluorine)-substituted and deuterium-substituted products thereof having 1 to 5 carbon atoms.

[0212] Among the examples, a structure having at least one substituent on the carbon at the α position of the cycloalkane (a carbon adjacent to the carbon at the condensation site in the cycloalkane condensed to an aryl ring or a heteroaryl ring) such as shown in the following structural formula is preferred, a structure having two substituents on the carbon at the α position is more preferred, and a structure having two substituents on both carbons at the α position is further preferred (having a total of four substituents). As the substituent, alkyl groups (especially methyl) having 1 to 5 carbon atoms, halogens (especially fluorine) and deuterium are listed. Particularly preferred is a structure having a partial structure represented by the following formula (B11) or the following formula (B12) bonded to adjacent carbon atoms in an aryl ring or a heteroaryl ring, and more preferred is a structure having a partial structure represented by the following formula (B11) bonded to adjacent carbon atoms.

[0213] [Chemistry 17]

[0214]

[0215] In each of formula (B11) and formula (B12), * represents a bonding position.

[0216] The number of cycloalkanes condensed on one aryl ring or heteroaryl ring is preferably 1 to 3, more preferably 1 or 2, and even more preferably 1. For example, the following shows an example in which one or more cycloalkanes are condensed on a benzene ring (phenyl). * represents the bonding position, which can be any of the carbons that constitute the benzene ring and do not constitute the cycloalkane. The cycloalkanes condensed as in formula (Cy-1-4) and formula (Cy-2-4) can also be condensed with each other. This is true whether the condensed ring (base) is an aryl ring or heteroaryl ring other than the benzene ring (phenyl), or whether the condensed cycloalkane is a cycloalkane other than cyclopentane or cyclohexane.

[0217] [Chemistry 18]

[0218]

[0219] At least one -CH 2- may be substituted by -O-. For example, the following shows one or more -CH in a cycloalkane condensed on a benzene ring (phenyl): 2 The same applies whether the ring (group) to be condensed is an aryl ring or a heteroaryl ring other than the benzene ring (phenyl), or whether the cycloalkane to be condensed is a cycloalkane other than cyclopentane or cyclohexane.

[0220] [Chemistry 19]

[0221]

[0222] The cycloalkane may be substituted with at least one substituent, and as the substituent, any substituent selected from the substituent group Z can be cited. Among these substituents, alkyl groups (e.g., alkyl groups having 1 to 6 carbon atoms) and cycloalkyl groups (e.g., cycloalkyl groups having 3 to 14 carbon atoms) are preferred. In addition, it is also preferred that any hydrogen group is substituted with a halogen (e.g., fluorine) or deuterium. In addition, when a cycloalkyl group is substituted, it may be a substitution form that forms a spiro ring structure. For example, the following shows an example in which a spiro ring structure is formed in a cycloalkane condensed on a benzene ring (phenyl). Regarding the * in each structural formula, in the case of a benzene ring, it refers to a benzene ring contained in the skeletal structure of the compound, and in the case of a phenyl group, it refers to a bond that is substituted in the skeletal structure of the compound.

[0223] [Chemistry 20]

[0224]

[0225] Examples of the cycloalkane condensation include, first, a form in which the ring represented by formula (G) in the polycyclic aromatic compound represented by formula (1), the aryl ring or heteroaryl ring in each of the A ring, the B ring and the C ring are condensed with a cycloalkane, or a form in which the aryl ring or heteroaryl ring contained in a substituent of the aryl ring or heteroaryl ring in each of the A ring, the B ring and the C ring are condensed with a cycloalkane.

[0226] As another embodiment of the cycloalkane condensation, the polycyclic aromatic compound represented by formula (1) may be exemplified as follows: NX >NR for aromatic groups condensed from cycloalkanes NX , a diarylamino group condensed by a cycloalkane (condensed to its aryl portion), a carbazolyl group condensed by a cycloalkane (condensed to its benzene ring portion), or a benzocarbazolyl group condensed by a cycloalkane (condensed to its benzene ring portion).

[0227] In addition, by introducing a cycloalkane structure into the polycyclic aromatic compound represented by formula (1), a further reduction in the melting point or sublimation temperature can be expected. The situation means that in the sublimation purification which is almost indispensable as a purification method for organic devices such as organic EL elements requiring high purity, since the purification can be carried out at a lower temperature, the thermal decomposition of the material can be avoided. In addition, the situation is also the same for the vacuum evaporation process which is a powerful means for making organic devices such as organic EL elements. The process can be implemented at a lower temperature, so the thermal decomposition of the material can be avoided, and a high-performance organic device can be obtained as a result. In addition, since the solubility in the organic solvent is improved by introducing a cycloalkane structure, it can also be applied to the production of components using a coating process. Among them, the present invention is not particularly limited to these principles.

[0228] <Substitution with heavy stable isotopes>

[0229] Each element in the polycyclic aromatic compound represented by formula (1) contains multiple isotopes in the natural occurrence ratio unless otherwise specified. All or part of the elements in each structural formula may contain more than the natural occurrence ratio (for example, in the case of boron-11 ( 11 In the present specification, it is referred to as "replaced with" "heavy stable isotopes". More specifically, at least one hydrogen can be replaced with deuterium, and at least one nitrogen can be replaced with nitrogen-15 ( 15 N), at least one sulfur may be substituted with sulfur-33 ( 33 S), sulfur-34 ( 34 S) or sulfur-36( 36 S), at least one oxygen may be substituted with oxygen-17 ( 17 O) or oxygen-18 ( 18 O), at least one carbon may be substituted with carbon-13 ( 13 C), at least one boron may be substituted with boron-11 ( 11 B). The same is true for the polycyclic aromatic compound represented by the formula (1A) described later. This description is also applicable to the polycyclic aromatic compound represented by the formula (1A). By substituting at least a portion of the elements with heavy stable isotopes, especially by using boron-11 ( 11 B) Substituting at least one boron can extend the life of an organic electroluminescent device using the polycyclic aromatic compound represented by the formula (1) as a dopant.

[0230] <Substitution using deuterium>

[0231] All or part of the hydrogen in the structure represented by formula (1) may be deuterium. The same is true for the polycyclic aromatic compounds represented by formula (1A) described later, and the following description is also applicable to these polycyclic aromatic compounds. For example, the hydrogen in the ring represented by formula (G), other aryl rings or heteroaryl rings in ring A, ring B, and ring C, and the substituents thereof may be substituted with deuterium, among which, the form in which all or part of the hydrogen in the aryl or heteroaryl group is substituted with deuterium can be listed. In addition, from the viewpoint of durability, it is also preferred that all or part of the hydrogen in the compound represented by formula (1) is deuterated.

[0232] <Formula (1A)>

[0233] Preferred examples of formula (1) include formula (1A).

[0234] [Chemistry 21]

[0235]

[0236] In formula (1A), R 1 ~R 11 At least one of them is a quaternary carbon substituent. Preferably R 1 ~R 11 1 to 4 of them are quaternary carbon substituents, more preferably 1 to 3 of them are quaternary carbon substituents, further preferably 1 to 2 of them are quaternary carbon substituents, and particularly preferably 1 of them is a quaternary carbon substituent. 1 ~R 11 Any of them may be a quaternary carbon substituent, preferably R 2 , R 5 or R 6 A quaternary carbon substituent.

[0237] In formula (1A), other R 1 ~R 11 (R is not a quaternary carbon substituent 1 ~R 11 ) are each independently hydrogen or a substituent. 1 ~R 11 The substituent of may be a substituted or unsubstituted alkenyl group, a substituted or unsubstituted arylthio group, in addition to the substituent selected from the substituent group Z, preferably a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, a triarylsilyl group or a cyano group. As the second substituent, a methyl group, a trifluoromethyl group, a halogen group, a cyano group and the like are also preferred.

[0238] In formula (1A), other R 1 ~R 11 In, R 1 ~R 3The adjacent bases in R 4 ~R 7 The adjacent bases in R 8 ~R 11 At least one group of the adjacent groups in may be bonded to each other and form a substituted or unsubstituted aryl ring or a substituted or unsubstituted heteroaryl ring together with the a ring, the b ring and the c ring. In this case, the substituent may be a substituted or unsubstituted alkenyl group, a substituted or unsubstituted arylthio group, in addition to the substituent selected from the substituent group Z, preferably a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, a triarylsilyl group or a cyano group. As the second substituent, a methyl group, a trifluoromethyl group, a halogen group, a cyano group and the like are also preferred.

[0239] Furthermore, in formula (1A), other R 1 ~R 11 In, R 1 ~R 3 The adjacent bases in R 4 ~R 7 The adjacent bases in R 8 ~R 11 At least one group of adjacent groups in the group is substituted together with the carbon atoms to which they are bonded by -N=, -N(-R)-, -O-, -S-, -C(-R)- 2 -、-Si(-R) 2 - or -Se- structure. The R, -C(-R)- of the -N(-R)- 2 -R and -Si(-R) 2 -R are independently hydrogen, aryl which may be substituted by alkyl or cycloalkyl, heteroaryl which may be substituted by alkyl or cycloalkyl, alkyl which may be substituted by cycloalkyl, or cycloalkyl which may be substituted by alkyl or cycloalkyl. 2 -" and "-Si(-R) 2 The two R's of "-" may be independently bonded to each other to form a ring.

[0240] In formula (1A), other R which is not a quaternary carbon substituent is 1 ~R 11 Preferably, all of them are hydrogen, or any 1 to 4 (preferably 1 to 2, more preferably 1) of them are substituted or unsubstituted aryl or substituted or unsubstituted heteroaryl and the others are hydrogen.

[0241] <Specific examples of polycyclic aromatic compounds>

[0242] Examples of the polycyclic aromatic compound of the present invention include compounds represented by any of the following structural formulae.

[0243] [Chemistry 22]

[0244]

[0245] [Chemistry 23]

[0246]

[0247] [Chemistry 24]

[0248]

[0249] [Chemistry 25]

[0250]

[0251] [Chemistry 26]

[0252]

[0253] [Chemistry 27]

[0254]

[0255] [Chemistry 28]

[0256]

[0257] [Chemistry 29]

[0258]

[0259] [Chemistry 30]

[0260]

[0261] [Chemistry 31]

[0262]

[0263] [Chemistry 32]

[0264]

[0265] <Method for producing polycyclic aromatic compounds>

[0266] As shown in the following process (1) or process (2), the polycyclic aromatic compound represented by the general formula (1) is firstly prepared by using a bonding group (including X 1 or X 2 The intermediate is prepared by bonding the ring A (ring a) with the ring B (ring b) and the ring C (ring c) (first reaction). Then, the bonding group (including Y 1The first reaction is to bond the A ring (a ring), the B ring (b ring) and the C ring (c ring) to produce a cyclized product (second reaction). In the first reaction, for example, if it is an etherification reaction, general reactions such as nucleophilic substitution reaction and Ullmann reaction can be used, and if it is an amination reaction, general reactions such as Buchwald-Hartwig reaction, nucleophilic substitution reaction and Goldberg amination can be used. In addition, in the second reaction, a tandem hetero-Friedel-Crafts reaction (continuous aromatic electrophilic substitution reaction, the same below) can be used.

[0267] [Chemistry 33]

[0268]

[0269] In addition, as shown in Scheme (3) or Scheme (4), in order to introduce Y that bonds the A ring (a ring), the B ring (b ring) and the C ring (c ring), 1 The reaction of Y is shown below as an example 1 is a boron atom, X 1 and X 2 First, use n-butyllithium, sec-butyllithium or tert-butyllithium to remove X 1 With X 2 The hydrogen atoms between are ortho-metallated. Then, boron trichloride or boron tribromide is added to carry out lithium-boron metal exchange, and then a Brünster base such as N,N-diisopropylethylamine is added to carry out a tandem boron-hetero Friedel-Crafts reaction, thereby obtaining the target product. In order to promote the reaction, a Lewis acid such as aluminum trichloride may also be added. The halogen atom Br in the formula may be F, Cl or I, and may be appropriately selected considering the reactivity of the substrate.

[0270] [Chemistry 34]

[0271]

[0272] Furthermore, by using the methods of flows (1) to (5), an intermediate that preliminarily includes the necessary substituents is used to synthesize a cyclized compound, thereby synthesizing a polycyclic aromatic compound represented by formula (1). In addition, after the cyclized compound is synthesized using an intermediate that includes a reactive substituent such as a halogen, a cross-coupling reaction (Suzuki coupling, Negishi coupling, etc.) can be used to convert it into a substituent of the desired reactive substituent. As the reactive substituent at this time, in order to suppress side reactions during the cyclization reaction, a low-reactivity group such as chlorine is preferably used. In addition, by halogenating the cyclized body having a halogen, the cyclized compound having a halogen can also be obtained.

[0273] 2. Organic devices

[0274] 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 an electron transport material.

[0275] <2-1. Organic electroluminescent element>

[0276] 2-1-1. Structure of organic electroluminescent element

[0277] Figure 1 This is a schematic cross-sectional view showing an example of an organic EL element.

[0278] Figure 1 The organic EL element 100 shown includes: a substrate 101, an anode 102 arranged on the substrate 101, a hole injection layer 103 arranged on the anode 102, a hole transport layer 104 arranged on the hole injection layer 103, a light-emitting layer 105 arranged on the hole transport layer 104, an electron transport layer 106 arranged on the light-emitting layer 105, an electron injection layer 107 arranged on the electron transport layer 106, and a cathode 108 arranged on the electron injection layer 107.

[0279] In addition, the organic EL element 100 can also reverse the production order to form a structure such as the following, which includes: a substrate 101, a cathode 108 disposed on the substrate 101, an electron injection layer 107 disposed on the cathode 108, an electron transport layer 106 disposed on the electron injection layer 107, a light-emitting layer 105 disposed on the electron transport layer 106, a hole transport layer 104 disposed on the light-emitting layer 105, a hole injection layer 103 disposed on the hole transport layer 104, and an anode 102 disposed on the hole injection layer 103.

[0280] The above-mentioned layers are not all indispensable layers, and the minimum structural unit is set to a structure including an anode 102, a light-emitting layer 105, and a cathode 108. The hole injection layer 103, the hole transport layer 104, the electron transport layer 106, and the electron injection layer 107 are layers that can be set arbitrarily. In addition, the above-mentioned layers may each include a single layer or a plurality of layers.

[0281] The morphology of the layers constituting the organic EL element may be, in addition to the structural morphology of “substrate / anode / hole injection layer / hole transport layer / luminescent layer / electron transport layer / electron injection layer / cathode”, “substrate / anode / hole injection layer / luminescent layer / electron transport layer / electron injection layer / cathode”, “substrate / anode / hole injection layer / luminescent layer / electron transport layer / electron injection layer / cathode”, “substrate / anode / hole injection layer / hole transport layer / luminescent layer / electron injection layer / cathode”, “substrate / anode / hole injection layer / hole transport layer / luminescent layer / electron injection layer / cathode”, “substrate / anode / hole injection layer / hole transport layer / luminescent layer / electron injection layer / cathode”. The structural morphology of the 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 injection layer / cathode", "substrate / anode / hole injection 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", and "substrate / anode / light-emitting layer / electron injection layer / cathode".

[0282] The organic EL element may further have any one or both selected from an electron blocking layer (electron blocking layer) and a hole blocking layer (hole blocking layer). The electron blocking layer has a LUMO that is shallower than the light-emitting layer and a HOMO that is close to the light-emitting layer or the hole transport layer, and is arranged between the light-emitting layer and the hole transport layer. Since the electrons are retained in the light-emitting layer and do not leak out to the hole transport layer, the shortening of the life caused by the degradation of the hole transport layer and the reduction in efficiency caused by the reduction 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 close to the light-emitting layer or the hole transport layer, and is arranged between the light-emitting layer and the electron transport layer. Since the holes are retained in the light-emitting layer and do not leak out to the electron transport layer, the shortening of the life caused by the degradation of the electron transport layer and the reduction in efficiency caused by the reduction 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.

[0283] The organic EL element may further have a high T1 layer. The high T1 layer has a higher T1 than the main compound, auxiliary dopant compound or emission dopant compound used in the light-emitting layer, and is arranged 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 element, but has a higher T1 than the compound used in the main body. By having a high T1 layer around the light-emitting layer, triplet energy can be enclosed, and the triplet energy that is usually unrelated to light emission in the fluorescent molecules can be converted into singlet energy, thereby obtaining high efficiency. The hole injection / transport layer or the electron blocking layer can also serve as the high T1 layer. The electron injection / transport layer or the hole blocking layer can also serve as the high T1 layer.

[0284] The polycyclic aromatic compound of the present invention can be used as a material for forming any one or more organic layers in an organic electroluminescent element. The polycyclic aromatic compound of the present invention is preferably used as a material for forming an electron transport layer, a material for forming an electron injection layer, or a material for forming a hole blocking layer, and is more preferably used as a material for forming an electron transport layer. The polycyclic aromatic compound of the present invention is particularly preferably used as a material for forming an electron transport layer of a TTF element, which utilizes the phenomenon of generating singlet excitons from multiple triplet excitons (triplet-triplet fusion (Triplet-Triplet Fusion, TTF)).

[0285] 2-1-2. Substrate in organic electroluminescent element

[0286] The substrate 101 is a support of the organic EL element 100, and quartz, glass, metal, plastic, etc. can be generally used. The substrate 101 is formed into a plate, film or sheet according to the purpose, for example, a glass plate, a metal plate, a metal foil, a plastic film, a plastic sheet, etc. can be used. Among them, glass plates and transparent synthetic resin plates such as polyester, polymethacrylate, polycarbonate, polysulfone, etc. are preferably used. If it is a glass substrate, soda-lime glass or alkali-free glass, etc. can be used. In addition, the thickness can be sufficient to maintain the mechanical strength. In addition, in order to improve the gas barrier property, a gas barrier film such as a fine silicon oxide film can also be provided on at least one side of the substrate 101. When a plate, film or sheet made of a synthetic resin with low gas barrier property is used as the substrate 101, it is particularly preferred to provide a gas barrier film.

[0287] 2-1-3. Anode in organic electroluminescent element

[0288] The anode 102 plays a role of injecting holes into the light-emitting layer 105. 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.

[0289] As materials for forming the anode 102, inorganic compounds and organic compounds can be cited. As inorganic compounds, for example, metals (aluminum, gold, silver, nickel, palladium, chromium, etc.), metal oxides (indium oxide, tin oxide, indium-tin oxide (Indium Tin Oxide, ITO), indium-zinc oxide (Indium Zinc Oxide, IZO), etc.), metal halides (copper iodide, etc.), copper sulfide, carbon black, ITO glass or Nesa glass, etc. As organic compounds, for example, polythiophenes such as poly(3-methylthiophene), conductive polymers such as polypyrrole and polyaniline, etc. can be cited. In addition, it can be appropriately selected from the substances used as the anode of the organic EL element for use.

[0290] 2-1-4. Hole injection layer and hole transport layer in organic electroluminescent element

[0291] The hole injection layer 103 plays a role of efficiently injecting holes migrated from the anode 102 into the light-emitting layer 105 or the hole transport layer 104. The hole transport layer 104 plays a role of efficiently transporting holes injected from the anode 102 or holes injected from the anode 102 via 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 stacking or mixing one or more hole injection / transport materials. In addition, an inorganic salt such as iron (III) chloride can be added to the hole injection / transport material to form a layer.

[0292] As a hole injection / transport material, it is necessary to efficiently inject / transmit holes from the positive electrode between electrodes to which an electric field is applied, and it is ideal that the hole injection efficiency is high and the injected holes are efficiently transmitted. Therefore, it is preferred that the material has a small ionization potential, a large hole mobility, and excellent stability, and is not prone to produce impurities that become traps during manufacture and use.

[0293] As materials for forming the hole injection layer 103 and the hole transport layer 104, any compound can be selected from compounds conventionally used as charge transport materials for holes in photoconductive materials, and known compounds used in hole injection layers and hole transport layers of p-type semiconductors and organic EL elements. Specific examples thereof include carbazole derivatives (N-phenylcarbazole, polyvinylcarbazole, etc.), biscarbazole derivatives such as bis(N-arylcarbazole) or bis(N-alkylcarbazole), triarylamine derivatives (polymers having an aromatic tertiary amino group in the main chain or side chain), 1,1-bis(4-di-p-tolylaminophenyl)cyclohexane, N,N'-diphenyl-N,N'-di(3-methylphenyl)-4,4'-diaminobiphenyl, N,N'-diphenyl-N,N'-dinaphthyl-4,4'-diaminobiphenyl, N,N'-diphenyl-N,N'-di(3-methylphenyl)-4,4'-diphenyl-1,1'-diamine, N,N'-dinaphthyl-N,N'-diphenyl-4,4'-diphenyl-1,1'-diamine, N 4 ,N 4 '-Diphenyl-N 4 ,N 4 '-Bis(9-phenyl-9H-carbazole-3-yl)-[1,1'-biphenyl]-4,4'-diamine, N 4 ,N 4 ,N 4 ',N 4 '-tetrakis([1,1'-biphenyl]-4-yl)-[1,1'-biphenyl]-4,4'-diamine, 4,4',4"-tris(3-methylphenyl(phenyl)amino)triphenylamine and other triphenylamine derivatives, starburst amine derivatives, etc.), stilbene derivatives, phthalocyanine derivatives (metal-free, copper phthalocyanine, etc.), pyrazoline derivatives, hydrazone compounds, benzofuran derivatives or thiophene derivatives, oxadiazole derivatives, quinoxaline derivatives (for example, 1,4,5,8,9,12-hexaazatriphenylene-2,3,6,7,10,11-hexacarbonitrile, etc.), heterocyclic compounds such as porphyrin derivatives, polysilane, etc. Among polymer systems, polycarbonate or styrene derivatives, polyvinylcarbazole and polysilane having the above monomers on the side chain are preferred, but there is no particular limitation as long as it is a compound that can form a thin film required for the production of a light-emitting element and can inject holes from the anode and then transport holes.

[0294] In addition, it is also known that the conductivity of organic semiconductors is strongly affected by their doping. Such organic semiconductor matrix materials contain compounds with good electron donating properties or compounds with good electron accepting properties. In order to dope electron donating materials, strong electron acceptors such as tetracyanoquinonedimethane (TCNQ) or 2,3,5,6-tetrafluorotetracyano-1,4-benzoquinonedimethane (F4TCNQ) are known (for example, refer to the literature "M. Pfeiffer, A. Bayer, T. Fritz, K. Leo (M. Pfeiffer , A. Beyer, T. Fritz, K. Leo), "Applied Physics Letters (Appl. Phys. Lett.)", 73(22), 3202-3204 (1998)" and the reference "J. Blochwitz, M. Pfeiffer, T. Fritz, K. Leo (J. Blochwitz, M. Pfeiffer, T. Fritz, K. Leo), "Applied Physics Letters (Appl. Phys. Lett.)", 73(6), 729-731 (1998)"). These so-called holes are generated through the electron migration process of the electron-donating basic material (hole transport material). The conductivity of the basic material varies greatly depending on the number and mobility of the holes. As a host material having hole transport properties, for example, benzidine derivatives (N,N'-bis(3-methylphenyl)-N,N'-bis(phenyl)benzidine (N,N'-bis(3-methylphenyl)-N,N'-bis(phenyl)benzidine, TPD), starburst amine derivatives (4,4',4"-tris(N,N-diphenylamino)triphenylamine (4,4',4"-tris(N,N-diphenylamino)triphenylamine, TDATA), or specific metal phthalocyanines (especially zinc phthalocyanine (ZnPc), etc.) are known (Japanese Patent Publication No. 2005-167175).

[0295] The hole injection layer material and the hole transport layer material can also be used in the hole layer material as the following polymer compound or its polymer cross-linked product, or the following pendant polymer compound or its pendant polymer cross-linked product, wherein the polymer compound is obtained by polymerizing a reactive compound substituted with a reactive substituent in the hole injection layer material and the hole transport layer material as a monomer, and the pendant polymer compound is obtained by reacting a main chain polymer with the reactive compound.

[0296] 2-1-5. Light-emitting layer in organic electroluminescent element

[0297] The light-emitting layer 105 is a layer that emits light by allowing holes injected from the anode 102 to recombine with 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 emits light by being excited by the recombination of holes and electrons, and preferably a compound that can form a stable thin film shape and exhibits strong luminescence (fluorescence) efficiency in a solid state.

[0298] The light-emitting layer may be a single layer or may include multiple layers, either of which is acceptable, and is formed of materials for the light-emitting layer (host material, dopant material). The host material and the dopant material may be one type or a combination of multiple types, either of which is acceptable. The dopant material may be contained in the entire host material or in part of the host material, either of which is acceptable. As a doping method, it can be formed by co-evaporation with the host material, or it can be pre-mixed with the host material and evaporated simultaneously.

[0299] The amount of the host material used varies depending on the type of the host material, and can be determined by matching the characteristics of the host material. The basis for the amount of the host material used is preferably 50% to 99.999% by mass of the total mass of the material for the light-emitting layer, more preferably 80% to 99.95% by mass, and further preferably 90% to 99.9% by mass. In the case where the host material is a combination of a hole-transporting host material and an electron-transporting host material, the amount of the host material used is the mass of the hole-transporting host material and the electron-transporting host material added together. The ratio of the amount of the hole-transporting host material to the electron-transporting host material used can be 1:9 to 9:1 in terms of mass ratio, preferably 4:6 to 6:4, and more preferably approximately 1:1.

[0300] The amount of the dopant material used varies depending on the type of the dopant material, and can be determined by matching the characteristics of the dopant material. The basis for the amount of the dopant material used is preferably 0.001% to 50% by mass of the total mass of the material for the light-emitting layer, more preferably 0.05% to 20% by mass, and further preferably 0.1% to 10% by mass. If it is within the above range, it is preferred, for example, in terms of preventing concentration quenching.

[0301] As the dopant material, an emitting dopant material and an auxiliary dopant material can be used. As the auxiliary dopant material, a thermally active delayed fluorescence material can be preferably used. In an organic electroluminescent element using an auxiliary dopant material, from the perspective of preventing concentration quenching, it is preferred that the emitting dopant material be used in a low concentration. From the perspective of the efficiency of the thermally active delayed fluorescence mechanism, it is preferred that the auxiliary dopant material be used in a high concentration. Furthermore, in an organic electroluminescent element using a thermally active delayed fluorescence auxiliary dopant material, from the perspective of the efficiency of the thermally active delayed fluorescence mechanism of the auxiliary dopant material, it is preferred that the emitting dopant material be used in a low concentration compared to the auxiliary dopant material.

[0302] When using auxiliary dopant materials, the base usage amounts of the main material, auxiliary dopant material and emission dopant material are 40% to 99% by mass, 59% to 1% by mass and 20% to 0.001% by mass, respectively, relative to the total mass of the materials for the light-emitting layer, preferably 60% to 95% by mass, 39% to 5% by mass and 10% to 0.01% by mass, respectively, and more preferably 70% to 90% by mass, 29% to 10% by mass and 5% to 0.05% by mass, respectively.

[0303] <Dopant materials>

[0304] As the dopant material, known compounds can be used, and it can be selected from various materials according to the desired luminescent color. Specifically, for example, phenanthrene, anthracene, pyrene, tetracene, pentacene, perylene, naphthopyrene, dibenzopyrene, rubrene, and Condensed ring derivatives such as benzoxazole derivatives, benzothiazole derivatives, benzimidazole derivatives, benzotriazole derivatives, oxazole derivatives, oxadiazole derivatives, thiazole derivatives, imidazole derivatives, thiadiazole derivatives, triazole derivatives, pyrazoline derivatives, stilbene derivatives, thiophene derivatives, tetraphenylbutadiene derivatives, cyclopentadiene derivatives, bisstyrylanthracene derivatives or stilbenebenzene derivatives such as bisstyrylanthracene derivatives (Japanese Patent Laid-Open No. 1-245087), bisstyrylarylene derivatives (Japanese Patent Laid-Open No. 2-247278), diazabenzodiindene derivatives, furan derivatives, benzofuran derivatives, phenylisobenzofuran, dimesitylisobenzofuran, di(2-methylphenyl)isobenzofuran, di(2-trifluoromethylphenyl)isobenzofuran, isobenzofuran derivatives such as phenylisobenzofuran, dibenzofuran derivatives, 7-dialkylaminocoumarin derivatives, 7- Coumarin derivatives such as piperidinyl coumarin derivatives, 7-hydroxycoumarin derivatives, 7-methoxycoumarin derivatives, 7-acetoxycoumarin derivatives, 3-benzothiazolyl coumarin derivatives, 3-benzimidazolyl coumarin derivatives, 3-benzoxazolyl coumarin derivatives, dicyanomethylene pyran derivatives, dicyanomethylene thiopyran derivatives, polymethine derivatives, cyanine derivatives, oxybenzanthracene derivatives, xanthene derivatives, rhodamine derivatives, fluorescein Derivatives, pyrylium derivatives, quinolone derivatives, acridine derivatives, oxazine derivatives, phenyl ether derivatives, quinacridone derivatives, quinazoline derivatives, pyrrolopyridine derivatives, furanopyridine derivatives, 1,2,5-thiadiazolopyrene derivatives, pyrromethene derivatives, purple ring ketone derivatives, pyrrolopyrrole derivatives, squarylium salt derivatives, purple anthrone derivatives, phenazine derivatives, acridone derivatives, deazotflavin derivatives, fluorene derivatives and benzofluorene derivatives, etc.

[0305] As the dopant material, it is also preferable to use a polycyclic aromatic compound containing boron described in International Publication No. 2015 / 102118, International Publication No. 2020 / 162600, paragraphs 0097 to 0269 of Japanese Patent Application Laid-Open No. 2021-077890, and the like.

[0306] As a dopant material, a thermally active delayed phosphor can also be used. The so-called "thermally active delayed phosphor" refers to a compound that absorbs thermal energy and undergoes reverse intersystem crossing from the lowest excited triplet state to the lowest excited singlet state, and is radiatively deactivated from the lowest excited singlet state, thereby emitting delayed fluorescence.

[0307] In the light-emitting layer, a phosphorescent material may also be used as a dopant. For example, iridium complexes described in Japanese Patent Laid-Open No. 2006-089398, Japanese Patent Laid-Open No. 2006-080419, Japanese Patent Laid-Open No. 2005-298483, Japanese Patent Laid-Open No. 2005-097263, Japanese Patent Laid-Open No. 2004-111379, U.S. Patent Application Publication No. 2019 / 0051845, or Japanese Patent Laid-Open No. 2014-239225, Advanced Materials (26: 7116-7121), Nature Asia Materials (NPG Asia Materials) (13, 53 (2021)), Applied Physics Letters (Applied Physics Letters) (117, 253301 (2020)), Light-Emitting Diodes - Prospects of Empirical Characteristics and Their Latest Technical Progress (Light-Emitting Diodes - Prospects of Empirical Characteristics and Their Latest Technical Progress) can be used. The platinum complex described in "Diode-An Outlook On the Empirical Features and Its Recent Technological Advancements" (Chapter 5).

[0308] <Main material>

[0309] Examples of the host material include condensed ring derivatives of anthracene, pyrene and the like which have been known as light emitters in the past, bistyryl derivatives such as bistyrylanthracene derivatives and distyrylbenzene derivatives, tetraphenylbutadiene derivatives, cyclopentadiene derivatives, fluorene derivatives, benzofluorene derivatives, N-phenylcarbazole derivatives, and carbazolenitrile derivatives.

[0310] As the host material, an anthracene derivative is particularly preferred. For anthracene derivatives, reference can be made to paragraphs 0124 to 0192 of JP-A-2020-136284 and paragraphs 0072 to 0257 of JP-A-2021-118354.

[0311] Specifically, examples of the anthracene derivative include compounds represented by formula (3-H) and compounds represented by formula (3-H2).

[0312] [Chemistry 35]

[0313]

[0314] In formula (3-H),

[0315] X and Ar 4are independently hydrogen or any group selected from the substituent group Z, all X and Ar 4 It will not become hydrogen at the same time.

[0316] At least one hydrogen in the compound represented by formula (3-H) may be substituted by halogen, cyano or deuterium.

[0317] In formula (3-H2), Ar c is a substituted or unsubstituted aryl group or a substituted or unsubstituted heteroaryl group, R c is hydrogen, alkyl, or cycloalkyl, Ar 11 ,Ar 12 ,Ar 13 ,Ar 14 ,Ar 15 ,Ar 16 ,Ar 17 and Ar 18 Each is independently hydrogen or any group selected from the substituent group Z. At least one hydrogen in the compound represented by formula (3-H2) may be substituted by halogen, cyano or deuterium.

[0318] The group represented by formula (A) is one of substituents that the anthracene compound represented by formula (3-H) may have.

[0319] [Chemistry 36]

[0320]

[0321] In formula (A), Y is -O-, -S- or >NR 29 , R 21 ~R 28 are independently hydrogen or any group selected from the substituent group Z, R 21 ~R 28 The adjacent groups in the group may be bonded to each other to form a hydrocarbon ring, an aromatic ring or a heteroaromatic ring. 29 is hydrogen or a substituted or unsubstituted aryl group. In addition, at least one hydrogen in formula (A) may be substituted by halogen, cyano or deuterium.

[0322] Y in formula (A) is preferably -O-.

[0323] From the viewpoint of promoting rather than inhibiting the generation of TADF in the light-emitting layer, the lowest excited triplet energy level (E T1 ) is higher than the highest E T1 E of dopant or auxiliary dopant T1 Specifically, the E of the main material T1 Preferably, the E of the dopant or auxiliary dopant is T1It is higher by 0.01 eV or more, more preferably higher by 0.03 eV or more, and even more preferably higher by 0.1 eV or more. T1 It is preferably 2.70 eV or more, more preferably 2.73 eV or more, and further preferably 2.80 eV or more.

[0324] TADF-active compounds can also be used as host materials.

[0325] The host material may be one kind or a combination of two or more kinds. In the case of a combination of two or more kinds, a combination of a hole-transporting host material and an electron-transporting host material is preferred.

[0326] 2-1-6. Electron injection layer and electron transport layer in organic electroluminescent element

[0327] The electron injection layer 107 plays a role of efficiently injecting electrons migrated from the cathode 108 into the light-emitting layer 105 or the electron transport layer 106. The electron transport layer 106 plays a role of efficiently transporting electrons injected from the cathode 108 or electrons injected from the cathode 108 via the electron injection layer 107 to the light-emitting layer 105. The electron transport layer 106 and the electron injection layer 107 are respectively formed by stacking or mixing one or more electron transport / injection materials, or are formed by a mixture of an electron transport / injection material and a polymer binder.

[0328] The so-called electron injection / transport layer is a layer responsible for injecting electrons from the cathode and then transmitting electrons, and it is desirable that the electron injection efficiency is high and the injected electrons are transmitted efficiently. Therefore, it is preferably a material with large electron affinity, large electron mobility, excellent stability, and impurities that are not easy to produce when manufacturing and using it. However, considering the transmission balance of holes and electrons, in the case of mainly playing the role of efficiently preventing the holes from the anode from being recombined and flowing to the cathode side, even if the electron transmission ability is not so high, it has the effect of improving luminous efficiency equally with the material with high electron transmission ability. Therefore, the electron injection / transport layer in the present embodiment may also include the function of the layer that can efficiently prevent the migration of holes.

[0329] As a material (electron transport material) for forming the electron transport layer 106 or the electron injection layer 107, it can be arbitrarily selected from the compounds conventionally used as electron transfer compounds in photoconductive materials, the electron injection layer of organic EL elements, and the known compounds used in the electron transport layer. The polycyclic aromatic compound of the present invention can be preferably used as a material for forming an electron transport layer or an electron injection layer. The polycyclic aromatic compound of the present invention can be combined with other materials described below to form an electron transport layer or an electron injection layer. Specifically, in addition to using an electron transport layer containing the polycyclic aromatic compound of the present invention, an electron injection layer formed of other materials or an additional electron transport layer formed of other materials can also be used. In addition to using an electron injection layer containing the polycyclic aromatic compound of the present invention, an electron transport layer formed of other materials or an additional electron injection layer formed of other materials can also be used.

[0330] In addition to the polycyclic aromatic compounds of the present invention, as the material used in the electron transport layer or the electron injection layer, it is preferably selected from at least one of the following compounds: a compound containing an aromatic ring or a heteroaromatic ring containing one or more atoms selected from carbon, hydrogen, oxygen, sulfur, silicon and phosphorus; a pyrrole derivative and its condensed ring derivative; and a metal complex with electron-accepting nitrogen. Specifically, it can be listed: condensed ring aromatic ring derivatives such as naphthalene and anthracene, styrene aromatic ring derivatives represented by 4,4'-bis(diphenylvinyl)biphenyl, purple ring ketone derivatives, coumarin derivatives, naphthalene dicarboximide derivatives, quinone derivatives such as anthraquinone or diphenoquinone, phosphine oxide derivatives, aryl nitrile derivatives and indole derivatives. As a metal complex with electron-accepting nitrogen, for example, hydroxyl azole complexes such as hydroxyphenyloxazole complexes, azomethine complexes, tropolone metal complexes, flavonol metal complexes and benzoquinoline metal complexes can be listed. These materials can be used alone or mixed with different materials.

[0331] In addition, specific examples of other electron transfer compounds include pyridine derivatives, naphthalene derivatives, anthracene derivatives, phenanthroline derivatives, perirone derivatives, coumarin derivatives, naphthalimide derivatives, anthraquinone derivatives, diphenoquinone derivatives, diphenylquinone derivatives, perylene derivatives, oxadiazole derivatives (1,3-bis[(4-tert-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 8-hydroxyquinoline derivatives, hydroxyquinoline metal complexes, quinoxaline derivatives, polymers of quinoxaline derivatives, benzoazole compounds, gallium complexes, pyrazole derivatives, perfluorinated phenylene derivatives, Biologicals, triazine derivatives, pyrazine derivatives, benzoquinoline derivatives (2,2'-bis(benzo[h]quinolin-2-yl)-9,9'-spirobifluorene, etc.), imidazopyridine derivatives, borane derivatives, benzimidazole derivatives (tris(N-phenylbenzimidazol-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"-terpyridine-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, bisphenylvinyl derivatives, etc.

[0332] In addition, metal complexes having electron-accepting nitrogen can also be used, examples of which include hydroxyquinoline metal complexes, hydroxyoxazole complexes such as hydroxyphenyloxazole complexes, azomethine complexes, tropolone metal complexes, flavonol metal complexes, and benzoquinoline metal complexes.

[0333] The materials can be used alone or in combination with different materials.

[0334] Among the above materials, preferred are borane derivatives, pyridine derivatives, fluoranthene derivatives, BO derivatives, anthracene derivatives, benzofluorene derivatives, phosphine oxide derivatives, pyrimidine derivatives, aromatic nitrile derivatives, triazine derivatives, benzimidazole derivatives, phenanthroline derivatives, and hydroxyquinoline metal complexes.

[0335] When the polycyclic aromatic compound of the present invention is combined with other materials to form an electron transport layer or an electron injection layer, the other materials preferably include a hydroxyquinoline metal complex or a triazine derivative. The polycyclic aromatic compound of the present invention and the hydroxyquinoline metal complex or the triazine derivative can be mixed to form one electron transport layer or an electron injection layer, or the polycyclic aromatic compound of the present invention and the hydroxyquinoline metal complex or the triazine derivative can be used separately in adjacent layers.

[0336] [Triazine derivatives]

[0337] The triazine derivative is, for example, a compound represented by the following formula (ETM-10), preferably a compound represented by the following formula (ETM-10-1). The details are described in US Patent Application Publication No. 2011 / 0156013.

[0338] [Chemistry 37]

[0339]

[0340] Ar is independently a substituted or unsubstituted aryl group or a substituted or unsubstituted heteroaryl group. n is an integer of 1 to 3, and is preferably 2 or 3.

[0341] Specific examples of "aryl" include: phenyl which is a monocyclic aromatic group; (2-, 3-, 4-)biphenyl which is a bicyclic aromatic group; (1-, 2-)naphthyl which is a condensed bicyclic aromatic group; terphenyl (m-terphenyl-2'-yl, m-terphenyl-4'-yl, m-terphenyl-5'-yl, o-terphenyl-3'-yl, o-terphenyl-4'-yl, p-terphenyl-2'-yl, m-terphenyl-2-yl, m-terphenyl-3-yl, m-terphenyl-4-yl, o-terphenyl-2-yl, o-terphenyl-3-yl, o-terphenyl-4-yl, p-terphenyl-2-yl, p-terphenyl-3-yl, p-terphenyl-4-yl); condensed tricyclic aromatic groups include: Acenaphthene-(1-, 3-, 4-, 5-)yl, fluorene-(1-, 2-, 3-, 4-, 9-)yl, phenanthren-(1-, 2-)yl, (1-, 2-, 3-, 4-, 9-)phenanthrenyl; tetraphenyl (5'-phenyl-m-terphenyl-2-yl, 5'-phenyl-m-terphenyl-3-yl, 5'-phenyl-m-terphenyl-4-yl, m-quaterphenyl) as a tetracyclic aromatic group; triphenylene-(1-, 2-)yl, pyrene-(1-, 2-, 4-)yl, tetracene-(1-, 2-, 5-)yl as a condensed tetracyclic aromatic group; perylene-(1-, 2-, 3-)yl, pentacene-(1-, 2-, 5-, 6-)yl as a condensed pentacyclic aromatic group, etc.

[0342] Specific examples of the heteroaryl group include furanyl, thienyl, pyrrolyl, oxazolyl, isoxazolyl, thiazolyl, isothiazolyl, imidazolyl, pyrazolyl, oxadiazolyl, furazanyl, thiadiazolyl, triazolyl, tetrazolyl, pyridyl, pyrimidinyl, pyridazinyl, pyrazinyl, triazinyl, benzofuranyl, isobenzofuranyl, benzo[b]thienyl, indolyl, isoindolyl, 1H-indazolyl, benzimidazolyl, benzoxazolyl, benzothiazolyl, 1H-benzotriazolyl, quinolyl, isoquinolyl, cinnolinyl, quinazolinyl, quinoxalinyl, phthalazinyl, naphthyridinyl, purinyl, pteridinyl, carbazolyl, acridinyl, phenoxazinyl, phenothiazinyl, phenazinyl, phenoxathiol, thianthrenyl, and indolizinyl.

[0343] In addition, the aryl group and the heteroaryl group may be substituted, and may be substituted with, for example, a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, a cyano group, or a halogen group, respectively.

[0344] Specific examples of the triazine derivatives include the following.

[0345] [Chemistry 38]

[0346]

[0347] [Hydroxyquinoline metal complexes]

[0348] Examples of the hydroxyquinoline metal complex include compounds represented by the formula (ETM-13).

[0349] [Chemistry 39]

[0350]

[0351] In formula (ETM-13), R 1 ~R 6 Each independently represents hydrogen or a substituent, M represents Li, Al, Ga, Be or Zn, and n represents an integer of 1 to 3.

[0352] Specific examples of hydroxyquinoline metal complexes include 8-hydroxyquinoline lithium (Liq), tris(8-hydroxyquinoline)aluminum (Alq3), tris(4-methyl-8-hydroxyquinoline)aluminum, tris(5-methyl-8-hydroxyquinoline)aluminum, tris(3,4-dimethyl-8-hydroxyquinoline)aluminum, tris(4,5-dimethyl-8-hydroxyquinoline)aluminum, tris(4,6-dimethyl-8-hydroxyquinoline)aluminum, bis(2-methyl-8-hydroxyquinoline)(phenol)aluminum, bis(2-methyl-8-hydroxyquinoline)(2-methylphenol)aluminum, bis(2-methyl-8-hydroxyquinoline)(3-methyl)aluminum, phenol) aluminum, bis(2-methyl-8-hydroxyquinoline)(4-methylphenol) aluminum, bis(2-methyl-8-hydroxyquinoline)(2-phenylphenol) aluminum, bis(2-methyl-8-hydroxyquinoline)(3-phenylphenol) aluminum, bis(2-methyl-8-hydroxyquinoline)(4-phenylphenol) aluminum, bis(2-methyl-8-hydroxyquinoline)(2,3-dimethylphenol) aluminum, bis(2-methyl-8-hydroxyquinoline)(2,6-dimethylphenol) aluminum, bis(2-methyl-8-hydroxyquinoline)(3,4-dimethylphenol) aluminum, bis(2-methyl-8-hydroxyquinoline)(3,5- dimethylphenol)aluminum, bis(2-methyl-8-hydroxyquinoline)(3,5-di-tert-butylphenol)aluminum, bis(2-methyl-8-hydroxyquinoline)(2,6-diphenylphenol)aluminum, bis(2-methyl-8-hydroxyquinoline)(2,4,6-triphenylphenol)aluminum, bis(2-methyl-8-hydroxyquinoline)(2,4,6-trimethylphenol)aluminum, bis(2-methyl-8-hydroxyquinoline)(2,4,5,6-tetramethylphenol)aluminum, bis(2-methyl-8-hydroxyquinoline)(1-naphthol)aluminum, bis(2-methyl-8-hydroxyquinoline)(2-naphthol)aluminum, bis(2,4 -Dimethyl-8-hydroxyquinoline)(2-phenylphenol)aluminum, bis(2,4-dimethyl-8-hydroxyquinoline)(3-phenylphenol)aluminum, bis(2,4-dimethyl-8-hydroxyquinoline)(4-phenylphenol)aluminum, bis(2,4-dimethyl-8-hydroxyquinoline)(3,5-dimethylphenol)aluminum, bis(2,4-dimethyl-8-hydroxyquinoline)(3,5-di-tert-butylphenol)aluminum, bis(2-methyl-8-hydroxyquinoline)aluminum-μ-oxo-bis(2-methyl-8-hydroxyquinoline)aluminum, bis(2,4-dimethyl-8-hydroxyquinoline)aluminum-μ-oxo-bis(2,4-dimethyl-8-hydroxyquinoline) aluminum, bis(2-methyl-4-ethyl-8-hydroxyquinoline) aluminum-μ-oxo-bis(2-methyl-4-ethyl-8-hydroxyquinoline) aluminum, bis(2-methyl-4-methoxy-8-hydroxyquinoline) aluminum-μ-oxo-bis(2-methyl-4-methoxy-8-hydroxyquinoline) aluminum, bis(2-methyl-5-cyano-8-hydroxyquinoline) aluminum-μ-oxo-bis(2-methyl-5-cyano-8-hydroxyquinoline) aluminum, bis(2-methyl-5-trifluoromethyl-8-hydroxyquinoline) aluminum-μ-oxo-bis(2-methyl-5-trifluoromethyl-8-hydroxyquinoline) aluminum, bis(10-hydroxybenzo[h]quinoline) beryllium, etc.

[0353] <Reducing substances>

[0354] The electron transport layer or the electron injection layer may further contain a substance that can reduce the material forming the electron transport layer or the electron injection layer. The reducing substance may be a variety of substances as long as it has a certain reducing property, for example, at least one selected from the group consisting of alkali metals, alkaline earth metals, rare earth metals, alkali metal oxides, alkali metal halides, alkaline earth metal oxides, alkaline earth 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.

[0355] As preferred reducing substances, alkali metals such as Na (work function 2.36eV), K (work function 2.28eV), Rb (work function 2.16eV) or Cs (work function 1.95eV) or alkaline earth metals such as Ca (work function 2.9eV), Sr (work function 2.0eV~2.5eV) or Ba (work function 2.52eV) can be listed, and substances with a work function of 2.9eV or less are particularly preferred. Among these, the more preferred reducing substances are alkali metals of K, Rb or Cs, and more preferably Rb or Cs, and most preferably Cs. The reducing ability of these alkali metals is particularly high. By adding a relatively small amount of the alkali metal to the material forming the electron transport layer or the electron injection layer, the luminous brightness in the organic EL element can be improved or the life can be prolonged. In addition, as the reducing substance having a work function of 2.9 eV or less, a combination of two or more of these alkali metals is also preferred, and a combination containing Cs is particularly preferred, such as a combination of Cs and Na, Cs and K, Cs and Rb, or Cs and Na and K. 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 light emission in the organic EL element can be improved or the life can be prolonged.

[0356] 2-1-7. Cathode in organic electroluminescent element

[0357] The cathode 108 plays a role of injecting electrons into the light-emitting layer 105 via the electron injection layer 107 and the electron transport layer 106 .

[0358] As the material forming the cathode 108, if it is a substance that can efficiently inject electrons into the organic layer, it is not particularly limited, and the same material as the material forming the anode 102 can be used. Among them, preferably 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-indium alloy, aluminum-lithium alloy such as lithium fluoride / aluminum, etc.) and the like. In order to improve the efficiency of electron injection to improve the characteristics of the element, lithium, sodium, potassium, cesium, calcium, magnesium or alloys containing these low work function metals are effective. However, generally speaking, these low work function metals are unstable in the atmosphere in most cases. In order to improve this point, it is known that there is a method of doping a trace amount of lithium, cesium or magnesium into the organic layer and using an electrode with high stability. As other dopants, inorganic salts such as lithium fluoride, cesium fluoride, lithium oxide and cesium oxide can also be used. Among them, it is not limited to these.

[0359] Furthermore, the following are preferred examples: for protecting the electrodes, metals such as platinum, gold, silver, copper, iron, tin, aluminum and indium, or alloys of these metals, inorganic substances such as silicon dioxide, titanium dioxide and silicon nitride, polyvinyl alcohol, vinyl chloride, hydrocarbon polymer compounds, etc. are stacked. The method for making these electrodes is not particularly limited as long as it is a method that can achieve conduction such as resistance heating, electron beam evaporation, sputtering, ion plating and coating.

[0360] 2-1-8. Method for producing organic electroluminescent element

[0361] Each layer constituting the organic EL element can be formed by making the material to constitute each layer into a thin film using a method such as vapor deposition, resistance heating vapor deposition, electron beam vapor deposition, sputtering, molecular stacking, printing, spin coating, casting, coating, etc. The film thickness of each layer formed in the above manner is not particularly limited and can be appropriately set according to the properties of the material, but is generally in the range of 2nm to 5000nm. The film thickness can generally be measured using a quartz oscillation film thickness measuring device or the like. When using the vapor deposition method for thin film formation, the vapor deposition conditions vary depending on the type of material, the target crystal structure and association structure of the film, etc. The vapor deposition conditions are generally preferably a boat heating temperature of +50°C to +400°C and a vacuum degree of 10 -6 Pa~10 -3 Pa, the vapor deposition rate is 0.01 nm / sec to 50 nm / sec, the substrate temperature is -150°C to +300°C, and the film thickness is appropriately set within the range of 2 nm to 5 μm.

[0362] When a direct current voltage is applied to the organic EL element obtained in the above manner, it can be applied with the anode as + polarity and the cathode as - polarity. If a voltage of about 2V to 40V is applied, light emission can be observed from the transparent or translucent electrode side (anode or cathode, or both). In addition, the organic EL element also emits light when a pulse current or an alternating current is applied. In addition, the waveform of the applied alternating current can be arbitrary.

[0363] Next, as an example of a method for producing an organic EL element, a method for producing an organic EL element including anode / hole injection layer / hole transport layer / light-emitting layer including a host material and a dopant material / electron transport layer / electron injection layer / cathode is described.

[0364] <Evaporation method>

[0365] On a suitable substrate, a thin film of an anode material is formed by a vapor deposition method to make an anode, and then a thin film of a hole injection layer and a hole transport layer is formed on the anode. The main material and the dopant material are co-evaporated on the thin film to form a thin film as a light-emitting layer, and an electron transport layer and an electron injection layer are formed on the light-emitting layer, and then a thin film containing a cathode material is formed by a vapor deposition method as a cathode, thereby obtaining a target organic EL element. In addition, in the production of the organic EL element, the production order can also be reversed, and the cathode, electron injection layer, electron transport layer, light-emitting layer, hole transport layer, hole injection layer, anode are produced in the order of cathode, electron injection layer, electron transport layer, light-emitting layer, hole transport layer, hole injection layer, anode.

[0366] 2-1-9. Application examples of organic electroluminescent elements

[0367] The present invention can also be applied to a display device including an organic EL element, a lighting device including an organic EL element, or the like.

[0368] A display device or lighting device including an organic EL element can be manufactured by a known method such as connecting the organic EL element of this embodiment to a known driving device, and can be driven using a known driving method such as DC driving, pulse driving, AC driving, etc. as appropriate.

[0369] As display devices, for example, panel displays such as color flat panel displays, flexible displays such as flexible color organic electroluminescent (EL) displays, etc. (for example, refer to Japanese Patent Laid-Open No. 10-335066, Japanese Patent Laid-Open No. 2003-321546, Japanese Patent Laid-Open No. 2004-281086, etc.). In addition, as display modes of displays, for example, matrix modes and segment modes can be listed. In addition, matrix display and segment display can coexist in the same panel.

[0370] In a matrix, pixels for display are arranged two-dimensionally in a grid or mosaic shape, etc., so that text or images are displayed by a collection of pixels. The shape or size of a pixel is determined according to the purpose. For example, in the image and text display of personal computers, monitors, and televisions, quadrilateral pixels with a side of less than 300 μm are usually used. In addition, in the case of large displays such as display screens, pixels with a side of mm are used. In the case of monochrome display, it is sufficient to arrange pixels of the same color. In the case of color display, red, green, and blue pixels are displayed in parallel. In the case, typical ones are triangular and stripe types. Moreover, as a driving method of the matrix, it can be either a line-sequential driving method or an active matrix. Line-sequential driving has the advantage of simple structure, but in the case of considering the operating characteristics, active matrix is ​​sometimes more excellent, so the driving method also needs to be used according to the purpose.

[0371] In the segmented method (type), a pattern is formed in a manner to display predetermined information, and the determined area is illuminated. Examples include: time or temperature display in a digital clock or thermometer, operating status display of audio equipment or induction cookers, and panel display of a car.

[0372] As lighting devices, for example, lighting devices such as indoor lighting, backlight sources of liquid crystal display devices, etc. can be listed (for example, refer to Japanese Patent Publication No. 2003-257621, Japanese Patent Publication No. 2003-277741, Japanese Patent Publication No. 2004-119211, etc.). Backlight sources are mainly used to improve the visibility of display devices that do not emit light by themselves, and are used for liquid crystal display devices, clocks, audio devices, automobile panels, display boards, and logos. In particular, as a backlight source for personal computers where thinning is becoming a problem in liquid crystal display devices, if it is considered that the existing methods are difficult to be thinned due to the inclusion of fluorescent lamps or light guide plates, the backlight source using the light-emitting element of this embodiment has the characteristics of being thin and lightweight.

[0373] [Example]

[0374] Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples.

[0375] In the examples, EI-MS (electron impact-mass spectrometry) refers to electron impact mass spectrometry.

[0376] <Synthesis of Compounds>

[0377] Synthesis Example (1): Synthesis of Compound (X1)

[0378] [Chemistry 40]

[0379]

[0380] First, 1-bromo-2,6-difluorobenzene (50.4 g, 0.260 mol) was added to phenol (24.6 g, 0.260 mol), potassium carbonate (36.0 g, 0.260 mol) and N-methylpyrrolidone (NMP (N-methylpyrrolidone), 500 mL) at room temperature under a nitrogen atmosphere, and heated and stirred at 120°C for 160 hours. Then, NMP was distilled off under reduced pressure, and toluene was added. Filtering was performed using a silica gel short-path column, and the solvent was distilled off under reduced pressure to obtain 2-bromo-1-fluoro-3-phenoxybenzene (52.8 g) as a light red liquid.

[0381] [Chemistry 41]

[0382]

[0383] Next, under nitrogen atmosphere and reflux temperature, a flask containing 2-bromo-1-fluoro-3-phenoxybenzene (43.3 g), 3-chlorophenol (25 g), potassium carbonate (44.8 g) and N-methylpyrrolidone (50 mL) was stirred for 42 hours. The reaction mixture was cooled, the solid was removed by filtration, and the solvent in the filtrate was concentrated under reduced pressure. The obtained oily substance was diluted with toluene and washed with water, and the toluene of the organic layer was removed by reduced pressure distillation. Heptane was added to the obtained oily substance, the precipitate was filtered, and the solid was dried under reduced pressure to obtain 2-bromo-1-(3-chlorophenoxy)-3-phenoxybenzene (49 g) as a brown solid.

[0384] [Chemistry 42]

[0385]

[0386] Into a flask containing 2-bromo-1-(3-chlorophenoxy)-3-phenoxybenzene (49g) and tetrahydrofuran (250mL), a tetrahydrofuran solution of isopropylmagnesium chloride-lithium chloride complex (1.29mol / L, 152mL) was added dropwise, stirred at room temperature for 2 hours, and then 2-isopropoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborane (43.7g) was added dropwise, and stirred at room temperature for 2 hours. Water and toluene were added to the reaction mixture, and tetrahydrofuran was removed by distillation under reduced pressure. Dilute hydrochloric acid was added thereto, the organic layer was separated and washed with water. The organic layer was decolorized using silica gel and concentrated under reduced pressure to obtain 2-(2-(3-chlorophenoxy)-6-phenoxyphenyl)-4,4,5,5-tetramethyl-1,3,2-dioxaborane (53.4g) as a light brown oil.

[0387] [Chemistry 43]

[0388]

[0389] A flask containing chlorobenzene (400 mL) and aluminum chloride (50.5 g) was heated to 120° C., and a solution of 2-(2-(3-chlorophenoxy)-6-phenoxyphenyl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (53.4 g) and chlorobenzene (130 mL) was added, and stirred at this temperature for 2 hours. The reaction mixture was cooled and added to ice water. Heptane was added to the mixture to precipitate a solid, and a milky white solid was obtained by filtration. Toluene was added to the filtrate, the organic layer was separated, and the organic layer was concentrated under reduced pressure, and the precipitate was washed with heptane to obtain a yellow solid. The yellow solid was dissolved in toluene, filtered using a silica gel short-path column, and the solvent was removed by distillation under reduced pressure to obtain 3-chloro-5,9-dioxa-13b-borazinane[3,2,1-de]anthracene (intermediate (Int-Cl-1)) (16 g) as a white solid.

[0390] [Chemistry 44]

[0391]

[0392] At reflux temperature, a flask containing intermediate (Int-Cl-1) (5.0 g), intermediate (Int-B-1) (5.9 g), palladium acetate (0.037 g), potassium phosphate (5.2 g), dicyclohexyl (2', 6'-dimethoxy-[1, 1'-biphenyl]-2-yl) phosphine (SPhos, 0.13 g), cyclopentyl methyl ether (CPME (cyclopentyl methyl ether), 50 mL) and water (5 mL) was stirred for 6 hours. Solmix A-11 (manufactured by Nippon Alcohol Sales) was added to the reaction mixture to precipitate a solid, and the filtered solid was washed with water and Solmix. Recrystallization was performed from toluene to obtain compound (X1) (8.3 g) as a light-colored solid.

[0393] [Chemistry 45]

[0394]

[0395] EI-MS observed m / z (M) = 584, confirming the formation of the target product.

[0396] Synthesis Example (2): Synthesis of Compound (X2)

[0397] In the same manner as in Synthesis Example (1), compound (X2) was obtained from intermediate (Int-Cl-1) and intermediate (Int-B-2).

[0398] [Chemistry 46]

[0399]

[0400] EI-MS observed m / z (M) = 584, confirming the formation of the target product.

[0401] Synthesis Example (3): Synthesis of Compound (X3)

[0402] In the same manner as in Synthesis Example (1), compound (X3) was obtained from intermediate (Int-Cl-2) and intermediate (Int-B-2).

[0403] [Chemistry 47]

[0404]

[0405] EI-MS observed m / z (M) = 584, confirming the formation of the target product.

[0406] Synthesis Example (4): Synthesis of Compound (X4)

[0407] In the same manner as in Synthesis Example (1), compound (X4) was obtained from intermediate (Int-Cl-1) and intermediate (Int-B-3).

[0408] [Chemistry 48]

[0409]

[0410] EI-MS observed m / z (M) = 600, confirming the formation of the target product.

[0411] Synthesis Example (5): Synthesis of Compound (X5)

[0412] In the same manner as in Synthesis Example (1), compound (X5) was obtained from intermediate (Int-Cl-1) and intermediate (Int-B-4).

[0413] [Chemistry 49]

[0414]

[0415] EI-MS observed m / z (M) = 584, confirming the formation of the target product.

[0416] Synthesis Example (6): Synthesis of Compound (X6)

[0417] In the same manner as in Synthesis Example (1), compound (X6) was obtained from intermediate (Int-Cl-1-1) and intermediate (Int-B-2).

[0418] [Chemistry 50]

[0419]

[0420] EI-MS observed m / z (M) = 660, confirming the formation of the target product.

[0421] Synthesis Example (7): Synthesis of Compound (X7)

[0422] In the same manner as in Synthesis Example (1), compound (X7) was obtained from intermediate (Int-Cl-1-1) and intermediate (Int-B-4).

[0423] [Chemistry 51]

[0424]

[0425] EI-MS observed m / z (M) = 660, confirming the formation of the target product.

[0426] Synthesis Example (8): Synthesis of Compound (X8)

[0427] In the same manner as in Synthesis Example (1), compound (X8) was obtained from intermediate (Int-Cl-1) and intermediate (Int-B-5).

[0428] [Chemistry 52]

[0429]

[0430] EI-MS observed m / z (M) = 586, confirming the formation of the target product.

[0431] Synthesis Example (9): Synthesis of Compound (X9)

[0432] In the same manner as in Synthesis Example (1), compound (X9) was obtained from intermediate (Int-Cl-3) and intermediate (Int-B-6).

[0433] [Chemistry 53]

[0434]

[0435] EI-MS observed m / z (M) = 662, confirming the formation of the target product.

[0436] Synthesis Example (10): Synthesis of Compound (X10)

[0437] In the same manner as in Synthesis Example (1), compound (X10) was obtained from intermediate (Int-Cl-1) and intermediate (Int-B-7).

[0438] [Chemistry 54]

[0439]

[0440] EI-MS observed m / z (M) = 676, confirming the formation of the target product.

[0441] Synthesis Example (11): Synthesis of Compound (X11)

[0442] In the same manner as in Synthesis Example (1), compound (X11) was obtained from intermediate (Int-Cl-4) and intermediate (Int-B-4).

[0443] [Chemistry 55]

[0444]

[0445] EI-MS observed m / z (M) = 584, confirming the formation of the target product.

[0446] Synthesis Example (12): Synthesis of Compound (X12)

[0447] In the same manner as in Synthesis Example (1), compound (X12) was obtained from intermediate (Int-Cl-4) and intermediate (Int-B-8).

[0448] [Chemistry 56]

[0449]

[0450] EI-MS observed m / z (M) = 660, confirming the formation of the target product.

[0451] Synthesis Example (13): Synthesis of Compound (X13)

[0452] In the same manner as in Synthesis Example (1), compound (X13) was obtained from intermediate (Int-Cl-1-1) and intermediate (Int-B-9).

[0453] [Chemistry 57]

[0454]

[0455] EI-MS observed m / z (M) = 662, confirming the formation of the target product.

[0456] Synthesis Example (14): Synthesis of Compound (X14)

[0457] In the same manner as in Synthesis Example (1), compound (X14) was obtained from intermediate (Int-Cl-1) and intermediate (Int-B-10).

[0458] [Chemistry 58]

[0459]

[0460] EI-MS observed m / z (M) = 750, confirming the formation of the target product.

[0461] <Fabrication and evaluation of organic EL elements>

[0462] Next, the preparation and evaluation of an organic EL device using the compound of the present invention will be described. However, the application of the compound of the present invention is not limited to the examples shown below, and the film thickness or constituent material of each layer can be appropriately changed according to the basic physical properties of the compound of the present invention.

[0463] [Production of organic EL elements]

[0464] The material composition and EL characteristic data of each layer in the organic EL devices of Examples 1-1 to 1-28 and Comparative Examples 1-1 to 1-8 are shown in Tables 1 and 2. The electron transport layer 2 was formed by co-evaporation of the compound described in the table and Liq at a mass ratio of 1 / 1.

[0465] [Table 1]

[0466]

[0467]

[0468] [Table 2]

[0469]

[0470] The chemical structures of "HI", "IL", "HT-1", "HT-2", "BH-1", "BD-1", "ET-1", "ET-2", "Liq", comparative compound (1), comparative compound (2), comparative compound (3) and comparative compound (4) in the above tables are shown below.

[0471] [Chemistry 59]

[0472]

[0473] [Chemistry 60]

[0474]

[0475] Comparative compounds (1) and (2) were synthesized according to the method described in the specification of Chinese Patent Application Publication No. 113773339. Comparative compounds (3) and (4) were synthesized from intermediates (A-11) and (A-22) and intermediates (A-1) and (A-23), respectively, in the same manner as in Synthesis Example (1).

[0476] [Chemistry 61]

[0477]

[0478] [Chemistry 62]

[0479]

[0480] (Example 1-1)

[0481] A 26 mm × 28 mm × 0.7 mm glass substrate (manufactured by Nippon Electric Glass Co., Ltd.) on which a 120 nm thick ITO film was formed by sputtering was used as a transparent support substrate. The transparent support substrate was fixed on a substrate holder of a commercially available vapor deposition apparatus (manufactured by Choshu Industry Co., Ltd.), and a molybdenum vapor deposition boat containing HI, IL, HT-1, HT-2, BH-1, BD-1, compound (X1), ET-2 and Liq, and an aluminum nitride vapor deposition boat containing Mg and Ag, respectively, were installed.

[0482] The following layers were formed in sequence on the ITO film of the transparent supporting substrate. The vacuum chamber was depressurized to 5×10 -4Pa, first, HI is heated and evaporated in a manner to make the film thickness 40nm, then IL is heated and evaporated in a manner to make the film thickness 5nm, then HT-1 is heated and evaporated in a manner to make the film thickness 45nm, then HT-2 is heated and evaporated in a manner to make the film thickness 10nm to form a hole layer comprising four layers. Then, BH-1 and BD-1 are heated at the same time and evaporated in a manner to make the film thickness 25nm to form a light-emitting layer. The evaporation rate is adjusted so that the mass ratio of BH-1 to BD-1 is approximately 98 to 2. Then, compound (X1) is heated and evaporated in a manner to make the film thickness 5nm to form an electron transport layer 1. Furthermore, ET-2 and Liq are heated at the same time and evaporated in a manner to make the film thickness 25nm to form an electron transport layer 2. The evaporation rate is adjusted so that the mass ratio of ET-2 to Liq is approximately 50 to 50. The deposition rate of each layer is 0.01 nm / sec to 1 nm / sec. Thereafter, Liq is heated and vapor-deposited at a deposition rate of 0.01 nm / sec to 0.1 nm / sec so that the film thickness becomes 1 nm, and then magnesium and silver are heated simultaneously and vapor-deposited so that the film thickness becomes 100 nm to form a cathode, thereby obtaining an organic EL element. At this time, the deposition rate is adjusted between 0.1 nm / sec to 10 nm / sec so that the atomic ratio of magnesium to silver becomes 10 to 1.

[0483] (Example 1-2 to Example 1-28, Comparative Example 1-1 to Comparative Example 1-8)

[0484] Organic EL devices of Examples 1-2 to 1-28 and Comparative Examples 1-1 to 1-8 were obtained by the method of Example 1-1 except that the materials of the electron transport layer 1 and the electron transport layer 2 were replaced with the materials described in the above tables.

[0485] [Evaluation of vapor deposition type organic EL device]

[0486] The quantum efficiency of a light-emitting element includes internal quantum efficiency and external quantum efficiency. The internal quantum efficiency indicates the proportion of external energy injected into the light-emitting layer of the light-emitting element as electrons (or holes) that is purely converted into photons. On the other hand, the external quantum efficiency is calculated based on the amount of photons released to the outside of the light-emitting element. A portion of the photons generated in the light-emitting layer are absorbed by the inside of the light-emitting element or continuously reflected without being released to the outside of the light-emitting element, so the external quantum efficiency is lower than the internal quantum efficiency.

[0487] The external quantum efficiency was measured as follows: Using a voltage / current generator R6144 manufactured by Advantest, a current was applied so that the device brightness reached 10 mA / cm 2 The element emits light by applying a voltage of . Using a spectroradiometer SR-3AR manufactured by TOPCON, the spectral radiance brightness in the visible light region is measured from a direction perpendicular to the light-emitting surface. Assuming that the light-emitting surface is a completely diffuse surface, the value of the spectral radiance brightness of each wavelength component measured is divided by the wavelength energy and multiplied by π to obtain the number of photons at each wavelength. Then, the number of photons is accumulated in the observed full wavelength region and set as the total number of photons released from the element. The value obtained by dividing the applied current value by the elementary charge is set as the number of carriers injected into the element, and the value obtained by dividing the total number of photons released from the element by the number of carriers injected into the element is the external quantum efficiency.

[0488] Organic EL devices of Examples 1-1 to 1-28 and Comparative Examples 1-1 to 1-8 were prepared, and a direct current voltage was applied using an ITO electrode as an anode and a magnesium / silver electrode as a cathode to measure the EL characteristics. 2 The characteristic driving voltage (V) and external quantum efficiency (%) of the light emission were then measured at 20 mA / cm 2 The results are shown in Tables 3 and 4.

[0489] [Table 3]

[0490]

[0491] [Table 4]

[0492]

[0493] As mentioned above, a part of the compounds of the present invention have been evaluated as materials for organic EL devices and shown to be excellent materials, but other compounds that have not been evaluated also have the same basic skeleton and are compounds with similar structures as a whole, and those skilled in the art can understand that they are also excellent materials for organic EL devices.

[0494] [Industrial Applicability]

[0495] According to a preferred embodiment of the present invention, an organic EL element having excellent driving voltage and luminous efficiency can be provided by producing an organic EL element using an electron transport material containing a polycyclic aromatic compound represented by the general formula (1).

Claims

1. A polycyclic aromatic compound represented by formula (1); [Chemistry 1] In formula (1), Ring A, Ring B and Ring C are each independently a substituted or unsubstituted aryl ring or a substituted or unsubstituted heteroaryl ring, wherein, At least one of the A ring, the B ring, and the C ring is a substituted aryl ring or a substituted heteroaryl ring, and contains a quaternary carbon substituent represented by formula (G) as a substituent, Y 1 For >B-, >P-, >P(=O)-, >P(=S)-, >Al-, >Ga-, >As-, >Si(-R IY )-or>Ge(-R GY )-, R IY and R GY are each independently a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted alkyl, or a substituted or unsubstituted cycloalkyl, X 1 and X 2 Each independently is >NR NX 、>O、>S、>C(-R CX )2、>Si(-R IX )2 or >Se, R NX , R CX and R IX are each independently hydrogen, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted alkyl, or substituted or unsubstituted cycloalkyl, and the two R CX Can bond to each other to form a ring, two R IX Can bond to each other to form a ring, R NX , R CX and R IX Each independently may be bonded to at least one of the A ring, the B ring, and the C ring via a linking group or a single bond, [Chemistry 2] In formula (G), * indicates the bond position, L is a single bond, -O-, -S-, a substituted or unsubstituted alkylene group, a substituted or unsubstituted arylene group, or a substituted or unsubstituted heteroarylene group, Any Z g is the carbon bonded to L, Other Z g are independently -N= or -C(-R g )=,R g are independently hydrogen or a substituent, Two adjacent R g may be bonded to each other and, together with the carbon atoms to which they are bonded, form a substituted or unsubstituted aryl ring or a substituted or unsubstituted heteroaryl ring, L 1 Both are hydrogen, or two L 1 Bond to each other to form single bonds, >O, >NR NL 、>Si(-R IL )2. >S or >Se, L 2 Both are hydrogen, or two L 2 Bond to each other to form single bonds, >O, >NR NL 、>Si(-R IL )2. >S or >Se, R NL and R IL are each independently hydrogen, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted alkyl, or substituted or unsubstituted cycloalkyl, and the two R IL Can bond to each other to form a ring, At least one of the aryl rings and heteroaryl rings selected from the group consisting of the aryl rings and heteroaryl rings in formula (1) may be condensed with at least one cycloalkane, the cycloalkane may be substituted with at least one substituent, and at least one -CH2- in the cycloalkane may be substituted with -O-, In formula (1), at least one hydrogen may be substituted with deuterium, and at least one nitrogen may be substituted with nitrogen-15( 15 N) substituted, at least one sulfur may be replaced by sulfur-33( 33 S), sulfur-34 ( 34 S) or sulfur-36( 36 S), at least one oxygen may be replaced by oxygen-17( 17 O) or oxygen-18 ( 18 O) substituted, at least one carbon may be substituted by carbon-13 ( 13 C) substituted, at least one boron may be substituted by boron-11( 11 B) Replacement.

2. The polycyclic aromatic compound according to claim 1, wherein Y 1 is>B-.

3. The polycyclic aromatic compound according to claim 1, wherein X 1 and X 2 are respectively independently >O, >S or >Se.

4. The polycyclic aromatic compound according to claim 1, wherein In formula (G), other Z g All are -C(-R g )=, any set of two adjacent R g may be bonded to each other and to the carbon atoms to which they are bonded to form a substituted or unsubstituted aryl ring or a substituted or unsubstituted heteroaryl ring, and the other R g All are hydrogen.

5. The polycyclic aromatic compound according to claim 1, wherein Two L 2 Bonded to each other to form single bonds.

6. The polycyclic aromatic compound according to claim 1, wherein L is a single bond.

7. The polycyclic aromatic compound according to claim 6, which is represented by any of the following formulas: [Chemistry 3] 8. The polycyclic aromatic compound according to claim 1, wherein L is -O-, -S-, a substituted or unsubstituted alkylene group, a substituted or unsubstituted arylene group, or a substituted or unsubstituted heteroarylene group.

9. The polycyclic aromatic compound according to claim 8, which is represented by any of the following formulas: [Chemistry 4] 10 . The polycyclic aromatic compound according to claim 1 , wherein at least one of the A ring, the B ring, and the C ring comprises a substituted or unsubstituted aryl group or a substituted or unsubstituted heteroaryl group as a substituent other than the quaternary carbon substituent.

11. A material for an organic device, comprising the polycyclic aromatic compound according to any one of claims 1 to 10. 12 . The material for an organic device according to claim 11 , which is a material for an electron transport layer or an electron injection layer of an organic electroluminescent element. 13 . An organic electroluminescent element comprising: a pair of electrodes including an anode and a cathode; and an organic layer disposed between the pair of electrodes and containing the polycyclic aromatic compound according to claim 1 .

14. The organic electroluminescent element according to claim 13, wherein The organic layer is an electron transport layer or an electron injection layer.

15. A display device or a lighting device, comprising the organic electroluminescent element according to claim 13.

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