Cyclic azine compound, material for organic electroluminescent element, electron transport material for organic electroluminescent element, and organic electroluminescent element

Abstract

The purpose of the present invention is to provide: a cyclic azine compound having both excellent driving voltage characteristics and current efficiency characteristics; a material for organic electroluminescent elements; an electron transport material for organic electroluminescent elements; and an organic electroluminescent element. The target cyclic azine compound is a cyclic azine compound having a specific structure represented by formula (1). [chemical] # imgabs0 #

Description

[0001] This application is a divisional application, and the Chinese national application number of the application it is directed to is 202080050694.3, the international application number is PCT / JP2020 / 028488, the filing date is July 22, 2020, the date of entry into China is January 12, 2022, and the invention title is "Cyclic Azaazine Compound, Material for Organic Electroluminescent Element, Electron Transport Material for Organic Electroluminescent Element, and Organic Electroluminescent Element". Technical Field

[0002] The present disclosure relates to a cyclic azaazine compound, a material for an organic electroluminescent element, an electron transport material for an organic electroluminescent element, and an organic electroluminescent element. Background Art

[0003] Organic electroluminescent elements are being actively developed for use not only in small displays but also in large televisions or lighting applications.

[0004] For example, Patent Document 1 discloses a cyclic azaazine compound having specific substituents as a material for an organic electroluminescent element, which helps to provide an organic electroluminescent element having excellent heat resistance, low driving voltage, and long life.

[0005] Prior Art Documents

[0006] Patent Documents

[0007] Patent Document 1: Japanese Patent Application Laid-Open No. 2008-280330 Summary of the Invention

[0008] Problems to be Solved by the Invention

[0009] However, in recent years, the market requirements for organic electroluminescent elements have become increasingly high, and there is a demand for the development of materials having both excellent driving voltage characteristics and current efficiency characteristics.

[0010] Here, although the organic electroluminescent element using the cyclic azaazine compound disclosed in Patent Document 1 exhibits excellent long-life characteristics and current efficiency characteristics, further improvement in driving voltage characteristics is required.

[0011] One aspect of the present disclosure is to provide a cyclic azaazine compound, a material for an organic electroluminescent element, and an electron transport material for an organic electroluminescent element having both excellent driving voltage characteristics and current efficiency characteristics.

[0012] Furthermore, another aspect of the present disclosure is to provide an organic electroluminescent element having both excellent driving voltage characteristics and current efficiency characteristics.

[0013] Means for Solving the Problems

[0014] According to one aspect of the present disclosure, there is provided a cyclic azine compound represented by formula (1):

[0015] [Chemical Formula 1]

[0016]

[0017] In formula (1),

[0018] Ar 1 is phenyl or 4-biphenylyl;

[0019] Ar 2 is any one of the groups represented by formulas (2-1) to (2-3);

[0020] [Chemical Formula 2]

[0021]

[0022] Ar 3 is the group represented by formula (3);

[0023] [Chemical Formula 3]

[0024]

[0025] In formula (3),

[0026] Ar 31 represents a hydrogen atom or any one of the groups represented by formulas (2-1) to (2-3).

[0027] According to another aspect of the present disclosure, there is provided a material for an organic electroluminescent element containing the above cyclic azine compound.

[0028] According to another aspect of the present disclosure, there is provided an electron transport material for an organic electroluminescent element containing the above cyclic azine compound.

[0029] According to another aspect of the present disclosure, there is provided an organic electroluminescent element containing the above cyclic azine compound.

[0030] Advantages of the Invention

[0031] According to one aspect of the present disclosure, a cyclic azine compound, a material for an organic electroluminescent element, and an electron transport material for an organic electroluminescent element, which have excellent driving voltage characteristics and current efficiency characteristics at the same time, can be obtained.

[0032] According to another aspect of the present disclosure, an organic electroluminescent element having excellent driving voltage characteristics and current efficiency characteristics at the same time can be obtained. Brief Description of the Drawings

[0033] Figure 1It is a schematic cross-sectional view showing an example of the laminated structure of an organic electroluminescent element including a cyclic azine compound according to one embodiment of the present disclosure.

[0034] Figure 2 It is a schematic cross-sectional view showing an example (Element Example - 1) of the laminated structure of an organic electroluminescent element including a cyclic azine compound according to one embodiment of the present disclosure.

[0035] Figure 3 It is a schematic cross-sectional view showing an example (Element Example - 2) of the laminated structure of an organic electroluminescent element including a cyclic azine compound according to one embodiment of the present disclosure. Detailed Description of the Invention

[0036] Hereinafter, a cyclic azine compound according to one embodiment of the present disclosure will be described in detail.

[0037] <Cyclic Azine Compound>

[0038] A cyclic azine compound according to one embodiment of the present disclosure is represented by Formula (1):

[0039] [Chemical Formula 4]

[0040]

[0041] In Formula (1),

[0042] Ar 1 is phenyl or 4-biphenylyl;

[0043] Ar 2 is a group represented by any one of Formulas (2-1) to (2-3);

[0044] [Chemical Formula 5]

[0045]

[0046] Ar 3 is a group represented by Formula (3);

[0047] [Chemical Formula 6]

[0048]

[0049] In Formula (3), Ar 31 represents a hydrogen atom or a group represented by any one of Formulas (2-1) to (2-3).

[0050] Hereinafter, the cyclic azine compound represented by Formula (1) may sometimes be referred to as cyclic azine compound (1). The definitions of the substituents in cyclic azine compound (1) and their preferred specific examples are described below, respectively.

[0051] [Ar2

[0052] Ar 2 is a group represented by any one of formulas (2-1) to (2-3).

[0053] [Chemical formula 7]

[0054]

[0055] From the aspect of having both excellent driving voltage characteristics and current efficiency characteristics, Ar 2 is more preferably a group represented by formula (2-1), (2-2a), (2-2b), (2-3a) or (2-3b).

[0056] [Chemical formula 8]

[0057]

[0058] [Regarding Ar 3

[0059] Ar 3 is a group represented by formula (3);

[0060] [Chemical formula 9]

[0061]

[0062] Ar 31 represents a hydrogen atom or a group represented by any one of formulas (2-1) to (2-3).

[0063] From the aspect of having both excellent driving voltage characteristics and current efficiency characteristics, Ar 3 is preferably a group represented by any one of formulas (3-1) to (3-9).

[0064] [Chemical formula 10]

[0065]

[0066] If the cyclic azine compound (1) is used as a part of the constituent components of an organic electroluminescent element (OLED; Organic Light Emitting Diode), effects such as high current efficiency and low driving voltage can be obtained. Especially when the cyclic azine compound (1) is used as the electron transport layer, these effects are further manifested.

[0067] [Preferred examples of the cyclic azine compound (1)]

[0068] ​​From the viewpoint of excellent driving voltage characteristics and current efficiency characteristics, a cyclic azine compound represented by any one of the compounds (1-1) to (1-90) shown in Tables 1 to 3 is more preferably used.

[0069] [Table 1]

[0070]

[0071] [Table 2]

[0072]

[0073] [Table 3]

[0074]

[0075] Among the cyclic azine compounds shown in Tables 1 to 3, particularly from the viewpoint of excellent driving voltage characteristics and current efficiency characteristics of the device, the cyclic azine compounds represented by Formula (1-6), Formula (1-15), Formula (1-48), Formula (1-49), Formula (1-51), Formula (1-52), Formula (1-54), Formula (1-64), Formula (1-65), Formula (1-66), Formula (1-67), Formula (1-71), Formula (1-73), or Formula (1-82) are preferred.

[0076] [Chemical Formula 11]

[0077]

[0078] Hereinafter, the use of the cyclic azine compound (1) will be described.

[0079] <Material for organic electroluminescent device, electron transport material for organic electroluminescent device>

[0080] The cyclic azine compound (1) is not particularly limited, and can be used, for example, as a material for an organic electroluminescent device. In addition, the cyclic azine compound (1) can be used, for example, as an electron transport material for an organic electroluminescent device.

[0081] That is, the material for an organic electroluminescent device according to one aspect of the present disclosure includes the cyclic azine compound (1). In addition, the electron transport material for an organic electroluminescent device according to one aspect of the present disclosure includes the cyclic azine compound (1). The material for an organic electroluminescent device and the electron transport material for an organic electroluminescent device containing the cyclic azine compound (1) contribute to the production of an organic electroluminescent device having excellent driving voltage characteristics and current efficiency characteristics.

[0082] <Organic electroluminescent device>

[0083] One embodiment of the organic electroluminescent device of the present disclosure includes a cyclic azine compound (1).

[0084] There is no particular limitation on the structure of the organic electroluminescent device. For example, the following structures (i) to (vii) can be cited.

[0085] (i): Anode / Light-emitting layer / Cathode

[0086] (ii): Anode / Hole transport layer / Light-emitting layer / Cathode

[0087] (iii): Anode / Light-emitting layer / Electron transport layer / Cathode

[0088] (iv): Anode / Hole transport layer / Light-emitting layer / Electron transport layer / Cathode

[0089] (v): Anode / Hole injection layer / Hole transport layer / Light-emitting layer / Electron transport layer / Electron injection layer / Cathode

[0090] (vi): Anode / Hole injection layer / Charge generation layer / Hole transport layer / Light-emitting layer / Electron transport layer / Cathode

[0091] (vii): Anode / Hole injection layer / Hole transport layer / Electron blocking layer / Light-emitting layer / Hole blocking layer / Electron transport layer / Electron injection layer / Cathode

[0092] Hereinafter, taking the structure of (vi) above as an example, the organic electroluminescent device of one embodiment of the present disclosure will be described in more detail with reference to Figure 1 The organic electroluminescent device of one embodiment of the present disclosure will be described in more detail. Figure 1 FIG. is a schematic cross-sectional view showing an example of the laminated structure of the organic electroluminescent device including the cyclic azine compound of one embodiment of the present disclosure.

[0093] It should be noted that Figure 1 The organic electroluminescent device shown has a so-called bottom-emitting type device structure, but the organic electroluminescent device of one embodiment of the present disclosure is not limited to the bottom-emitting type device structure. That is, the organic electroluminescent device of one embodiment of the present disclosure can be a top-emitting type device structure or other known device structures.

[0094] The organic electroluminescent device 100 sequentially includes a substrate 1, an anode 2, a hole injection layer 3, a charge generation layer 4, a hole transport layer 5, a light-emitting layer 6, an electron transport layer 7, and a cathode 8. However, some of these layers can be omitted. On the contrary, other layers can be added. For example, an electron injection layer can be provided between the electron transport layer 7 and the cathode 8, or the charge generation layer 4 can be omitted and the hole transport layer 5 can be directly provided on the hole injection layer 3.

[0095] Alternatively, instead of the two or more layers, a single layer structure may be provided, such as an electron injection / transport layer that combines the functions of an electron injection layer and an electron transport layer in a single layer, i.e., a single layer that combines the functions of two or more layers. Further, for example, the single-layer hole transport layer 5 and the single-layer electron transport layer 7 may each be composed of two or more layers.

[0096] [Layer containing the cyclic azine compound represented by formula (1)]

[0097] The organic electroluminescent element contains the cyclic azine compound represented by the above formula (1) in at least one layer selected from the group consisting of the light-emitting layer and the layers between the light-emitting layer and the cathode. Therefore, in Figure 1 In the structural example shown, the organic electroluminescent element 100 contains the cyclic azine compound (1) in at least one layer selected from the group consisting of the light-emitting layer 6 and the electron transport layer 7. In particular, it is preferred that the electron transport layer 7 contains the cyclic azine compound (1).

[0098] It should be noted that the cyclic azine compound (1) may be contained in two or more layers of the organic electroluminescent element. When an electron injection layer is provided between the electron transport layer and the cathode, the electron injection layer may also contain the cyclic azine compound (1).

[0099] Hereinafter, the organic electroluminescent element 100 in which the electron transport layer 7 contains the cyclic azine compound (1) will be described.

[0100] [Substrate 1]

[0101] The substrate is not particularly limited, and examples thereof include a glass plate, a quartz plate, a plastic plate, etc. Further, in the case of a structure in which light is emitted from the substrate 1 side, the substrate 1 is transparent to the wavelength of light.

[0102] As the plastic film having light-transmitting properties, for example, films made of polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyethersulfone (PES), polyetherimide, polyetheretherketone, polyphenylene sulfide, polyarylate, polyimide, polycarbonate (PC), cellulose triacetate (TAC), cellulose acetate propionate (CAP), etc. can be cited.

[0103] [Anode 2]

[0104] The anode 2 is provided on the substrate 1 (on the side of the hole injection layer 3).

[0105] In the case of an organic electroluminescent element having a structure in which light is extracted through the anode, the anode is formed of a material that allows or substantially allows the light to pass through.

[0106] The transparent material for the anode is not particularly limited. For example, indium-tin oxide (ITO; Indium Tin Oxide), indium-zinc oxide (IZO: Indium Zinc Oxide), tin oxide, aluminum-doped tin oxide, magnesium-indium oxide, nickel-tungsten oxide, other metal oxides, metal nitrides such as gallium nitride, metal selenides such as zinc selenide, and metal sulfides such as zinc sulfide can be cited.

[0107] It should be noted that in the case of an organic electroluminescent element having a structure that emits light only from the cathode side, the transmission characteristics of the anode are not important. Therefore, as an example of the material for the anode in this case, gold, iridium, molybdenum, palladium, platinum, etc. can be cited.

[0108] A buffer layer (electrode interface layer) can also be provided on the anode.

[0109] [Hole injection layer 3, hole transport layer 5]

[0110] Between the anode 2 and the light-emitting layer 6 described later, a hole injection layer 3, a charge generation layer 4 described later, and a hole transport layer 5 are provided in this order from the anode 2 side.

[0111] The hole injection layer and the hole transport layer have the function of transferring the holes injected from the anode to the light-emitting layer. By interposing the hole injection layer and the hole transport layer between the anode and the light-emitting layer, a large amount of holes can be injected into the light-emitting layer at a lower electric field.

[0112] In addition, the hole injection layer and the hole transport layer also function as electron barrier layers. That is, the case where electrons injected from the cathode and transported from the electron injection layer and / or the electron transport layer to the light-emitting layer leak to the hole injection layer and / or the hole transport layer is suppressed by the electron barrier at the interface between the light-emitting layer and the hole injection layer and / or the hole transport layer. As a result, these electrons are accumulated at the interface within the light-emitting layer, bringing effects such as an increase in current efficiency, and an organic electroluminescent element with excellent light-emitting performance can be obtained.

[0113] As the material for the hole injection layer and the hole transport layer, it has at least any one of hole injectability, hole transportability, and electron barrier property. The material for the hole injection layer and the hole transport layer can be either an organic substance or an inorganic substance.

[0114] Specific examples of materials for the hole injection layer and the hole transport layer include triazole derivatives, oxadiazole derivatives, imidazole derivatives, polyarylalkane derivatives, pyrazoline derivatives, pyrazolinone derivatives, phenylenediamine derivatives, arylamine derivatives, amino-substituted chalcone derivatives, oxazole derivatives, styryl anthracene derivatives, fluorenone derivatives, hydrazone derivatives, stilbene derivatives, silazane derivatives, aniline-based copolymers, conductive polymer oligomers (especially thiophene oligomers), porphyrin compounds, aromatic tertiary amine compounds, styrylamine compounds, etc. Among them, porphyrin compounds, aromatic tertiary amine compounds, and styrylamine compounds are preferred, and aromatic tertiary amine compounds are particularly preferred.

[0115] Specific examples of the aromatic tertiary amine compound and the styrylamine compound include N,N,N’,N’-tetraphenyl-4,4’-diaminophenyl, N,N’-diphenyl-N,N’-bis(3-methylphenyl)-[1,1’-biphenyl]-4,4’-diamine (TPD), 2,2-bis(4-di-p-tolylaminophenyl)propane, 1,1-bis(4-di-p-tolylaminophenyl)cyclohexane, N,N,N’,N’-tetra-p-tolyl-4,4’-diaminobiphenyl, 1,1-bis(4-di-p-tolylaminophenyl)-4-phenylcyclohexane, bis(4-dimethylamino-2-methylphenyl)phenylmethane, bis(4-di-p-tolylaminophenyl)phenylmethane, N,N’-diphenyl-N,N’-bis(4-methoxyphenyl)-4,4’-diaminobiphenyl, N,N,N’,N’-tetraphenyl-4,4’-diaminodiphenyl ether, 4,4’-bis(diphenylamino)quaterphenyl, N,N,N-tri(p-tolyl)amine, 4-(di-p-tolylamino)-4’-[4-(di-p-tolylamino)styryl]stilbene, 4-N,N-diphenylamino-(2-diphenylvinyl)benzene, 3-methoxy-4’-N,N-diphenylamino stilbene, N-phenylcarbazole, 4,4’-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (NPD), 4,4’,4”-tris[N-(3-methylphenyl)-N-phenylamino]triphenylamine (MTDATA), etc.

[0116] In addition, inorganic compounds such as p-type -Si and p-type -SiC can also be cited as an example of the material for the hole injection layer and the hole transport layer.

[0117] The hole injection layer and the hole transport layer can be a single-layer structure composed of one or two or more materials, or a laminated structure composed of two or more layers with the same composition or different compositions.

[0118] [Charge generation layer 4]

[0119] A charge generation layer 4 can also be provided between the hole injection layer 3 and the hole transport layer 5.

[0120] There is no particular limitation on the material of the charge generation layer. For example, 2,3,6,7,10,11 - hexacyano - 2,3 - dipyrazino[2,3 - f:2’,3’ - h]quinoxaline (HAT - CN) can be cited.

[0121] The charge generation layer can be a single - layer structure composed of one or two or more materials, or a laminated structure composed of two or more layers with the same composition or different compositions.

[0122] [Light - emitting layer 6]

[0123] A light - emitting layer 6 is provided between the hole transport layer 5 and the electron transport layer 7 described later.

[0124] As the material of the light - emitting layer, phosphorescent materials, fluorescent materials, and thermally activated delayed fluorescence materials can be cited. In the light - emitting layer, electron - hole pairs recombine, and as a result, light emission occurs.

[0125] The light - emitting layer can be composed of a single low - molecular material or a single polymer material. More generally, it is composed of a host material doped with a guest compound. Light emission is mainly generated by the dopant and can have any color.

[0126] As the host material, for example, compounds having a biphenyl group, a fluorene group, a triphenylsilyl group, a carbazolyl group, a pyrene group, and an anthracenyl group can be cited. More specifically, DPVBi (4,4’ - bis(2,2 - diphenylethynyl) - 1,1’ - biphenyl), BCzVBi (4,4’ - bis(9 - ethyl - 3 - carbazolylvinyl)1,1’ - biphenyl), TBADN (2 - tert - butyl - 9,10 - bis(2 - naphthyl)anthracene), ADN (9,10 - bis(2 - naphthyl)anthracene), CBP (4,4’ - bis(carbazol - 9 - yl)biphenyl), CDBP (4,4’ - bis(carbazol - 9 - yl) - 2,2’ - dimethylbiphenyl), 2 - (9 - phenylcarbazol - 3 - yl) - 9 - [4 - (4 - phenylphenylquinazolin - 2 - yl)carbazole], 9,10 - bis(biphenyl)anthracene, etc. can be cited.

[0127] As the fluorescent dopant, for example, anthracene, pyrene, tetracene, xanthene, perylene, rubrene, coumarin, rhodamine, quinacridone, dicyanomethylene pyran compounds, thiopyran compounds, polymethine compounds, pyranylium, thiopyrylium compounds, fluorene derivatives, diindenoperylene derivatives, indenoperylene derivatives, bis(azinyl)amine boron compounds, bis(azinyl)methane compounds, quinolone compounds, etc. can be cited. The fluorescent dopant can also be a substance obtained by combining two or more selected from them.

[0128] As the phosphorescent dopant, metal complexes such as iridium complexes, platinum complexes, palladium complexes, and osmium complexes can be cited, for example.

[0129] As specific examples of the fluorescent dopant and the phosphorescent dopant, Alq3 (aluminum tris(8-hydroxyquinoline)), DPAVBi (4,4'-bis[4-(di-p-tolylamino)styryl]biphenyl), perylene, bis[2-(4-hexylphenyl)quinoline](acetylacetonate)iridium(III), Ir(PPy) 3 (tris(2-phenylpyridine)iridium(III)), and FIrPic (bis(3,5-difluoro-2-(2-pyridyl)phenyl-(2-carboxypyridyl)iridium(III))) etc. can be cited.

[0130] The thermally activated delayed fluorescence emitting material can be used as either the above-mentioned host material or guest material. In addition, although the thermally activated delayed fluorescence emitting material itself does not emit light, it can also function to effectively transfer the excitation energy to the fluorescent dopant that forms the light-emitting layer simultaneously with the thermally activated delayed fluorescence emitting material.

[0131] As specific examples of the thermally activated delayed fluorescence emission, 4Cz-IPN (2,4,5,6-tetra(9-carbazolyl)-isophthalonitrile), 5Cz-BN (2,3,4,5,6-penta(9-carbazolyl)-benzonitrile), DACTII (2-[3,6-bis(diphenylamino)carbazol-9-yl)phenyl]-4,6-diphenyl-1,3,5-triazine) etc. can be cited.

[0132] In addition, the light-emitting material is not limited to being contained only in the light-emitting layer. For example, the layer adjacent to the light-emitting layer (the hole transport layer 5 or the electron transport layer 7) can also contain the light-emitting material. Thereby, the current efficiency of the organic electroluminescent element can be further improved.

[0133] The light-emitting layer can be a single-layer structure composed of one or two or more materials, or a laminated structure composed of two or more layers with the same composition or different compositions.

[0134] [Electron transport layer 7]

[0135] An electron transport layer 7 is provided between the light-emitting layer 6 and the cathode 8 described later.

[0136] The electron transport layer has a function of transferring the electrons injected from the cathode to the light-emitting layer. By interposing the electron transport layer between the cathode and the light-emitting layer, the electrons can be injected into the light-emitting layer at a lower electric field.

[0137] As described above, the electron transport layer preferably contains the cyclic azine compound represented by the above formula (1).

[0138] In addition, besides the cyclic azine compound (1), the electron transport layer may further contain known electron transport materials. Examples of known electron transport materials include lithium 8-hydroxyquinolate (Liq), zinc bis(8-hydroxyquinolate), copper bis(8-hydroxyquinolate), manganese bis(8-hydroxyquinolate), aluminum tris(8-hydroxyquinolate), aluminum tris(2-methyl-8-hydroxyquinolate), gallium tris(8-hydroxyquinolate), beryllium bis(10-hydroxybenzo[h]quinolate), zinc bis(10-hydroxybenzo[h]quinolate), chloro-gallium bis(2-methyl-8-hydroxyquinolate), (o-cresolato)gallium bis(2-methyl-8-hydroxyquinolate), aluminum bis(2-methyl-8-hydroxyquinolate)-1-naphthoate, or gallium bis(2-methyl-8-hydroxyquinolate)-2-naphthoate, 2-[3-(9-phenanthryl)-5-(3-pyridyl)phenyl]-4,6-diphenyl-1,3,5-triazine, and 2-(4'',2''-dipyridyl[1,1':3',1''-terphenyl]-5-yl)-4,6-diphenyl-1,3,5-triazine, BCP (2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline), Bphen (4,7-diphenyl-1,10-phenanthroline), BAlq (bis(2-methyl-8-hydroxyquinolate)-4-(phenylphenoxy)aluminum), and beryllium bis(10-hydroxybenzo[h]quinolate), etc.

[0139] The electron transport layer may be a single-layer structure composed of one or more than two materials, or a laminated structure composed of two or more layers with the same or different compositions.

[0140] In the case where the electron transport layer has a two-layer structure with the first electron transport layer on the light-emitting layer side and the second electron transport layer on the cathode side, it is preferred that the second electron transport layer contains the cyclic azine compound (1).

[0141] [Cathode 8]

[0142] A cathode 8 is provided on the electron transport layer 7.

[0143] In the case of an organic electroluminescent element having a structure that only extracts the light passing through the anode, the cathode can be formed of any conductive material.

[0144] Examples of the material for the cathode include sodium, sodium-potassium alloy, magnesium, lithium, magnesium / copper mixture, magnesium / silver mixture, magnesium / aluminum mixture, magnesium / indium mixture, aluminum / aluminum oxide (Al 2 O 3 ) mixture, indium, lithium / aluminum mixture, rare earth metals, etc.

[0145] A buffer layer (electrode interface layer) may also be provided on the cathode (on the electron transport layer side).

[0146] [Method for forming each layer]

[0147] Each layer other than the electrodes (anode, cathode) described above can be formed by thinning the materials of each layer (together with materials such as binder resins and solvents as needed) into a film using known methods such as vacuum evaporation, spin coating, casting, LB (Langmuir - Blodgett method), etc.

[0148] The film thickness of each layer thus formed is not particularly limited and can be appropriately selected according to circumstances, usually in the range of 5 nm to 5 μm.

[0149] The anode and cathode can be formed by thinning the electrode materials by methods such as evaporation or sputtering. When evaporating or sputtering, a pattern can be formed by means of a mask of a desired shape, or after forming a film by evaporation or sputtering, etc., a pattern of a desired shape can be formed by photolithography.

[0150] The film thickness of the anode and cathode is preferably 1 μm or less, more preferably 10 nm or more and 200 nm or less.

[0151] The organic electroluminescent element of one embodiment of the present disclosure can be used as a kind of lamp such as for lighting or an exposure light source, and can also be used as a projection device of a type for projecting an image or a display device (display) of a type for directly visually confirming a still image or a moving image. When used as a display device for reproducing moving images, the driving method can be a simple matrix (passive matrix) method or an active matrix method. In addition, by using two or more organic electroluminescent elements of this embodiment having different emission colors, a full - color display device can be manufactured.

[0152] It should be noted that the cyclic azine compound (1) of one embodiment of the present disclosure can be synthesized by appropriately combining known reactions (such as Suzuki - Miyaura cross - coupling reaction, etc.).

[0153] For example, the cyclic azine compound (1) of one embodiment of the present disclosure can be synthesized according to the production method shown in any one of the following reaction formulas (a) to (f), but should not be construed as being limited by any of these examples.

[0154] [Chemical formula 12]

[0155] Reaction formula (a)

[0156]

[0157] [Chemical formula 13]

[0158] Reaction formula (b)

[0159]

[0160] [Chemical Formula 14]

[0161] Reaction formula (c)

[0162]

[0163] [Chemical Formula 15]

[0164] Reaction formula (d)

[0165]

[0166] [Chemical Formula 16]

[0167] Reaction formula (e)

[0168]

[0169] [Chemical Formula 17]

[0170] Reaction formula (f)

[0171]

[0172] In reaction formulas (a) to (f), Ar 1 , Ar 2 and Ar 3 are as defined in formula (1).

[0173] X 2 and X 3 each independently represent a leaving group. There is no particular limitation on the leaving group, and examples thereof include a chlorine atom, a bromine atom, an iodine atom, a trifluoromethanesulfonyloxy group, etc. Among them, from the viewpoint of good reaction yield, a bromine atom or a chlorine atom is preferred. However, from the viewpoint of availability of raw materials, a trifluoromethanesulfonyloxy group is sometimes preferably used.

[0174] Y 2 and Y 3 each independently represent a metal-containing group such as ZnR 1 , MgR 2 , or Sn(R 3 ) 3 ; or a boron-containing group such as B(OR 4 ) 2 ; wherein, R 1 and R 2 each independently represent a chlorine atom, a bromine atom or an iodine atom; R 3 represents an alkyl group having 1 to 4 carbon atoms or a phenyl group; R 4 represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms or a phenyl group; the two Rof B(OR 4 ) 2 4may be the same or different. Additionally, two R 4 may also combine to form a ring containing an oxygen atom and a boron atom.

[0175] Examples of ZnR 1 and MgR 2 include ZnCl, ZnBr, ZnI, MgCl, MgBr, MgI, etc.

[0176] Examples of Sn(R 3 ) 3 include Sn(Me) 3 and Sn(Bu) 3 , etc.

[0177] Examples of B(OR 4 ) 2 include B(OH) 2 , B(OMe) 2 , B(O i Pr) 2 , B(OBu) 2 , etc. Additionally, as an example of B(OR 4 ) 4 when two R 2 combine to form a ring containing an oxygen atom and a boron atom, there is no particular limitation, and groups shown in the following (I) to (VI) can be exemplified. Considering the good yield, the group shown in (II) is preferred.

[0178] [Chemical formula 18]

[0179]

[0180] Regarding the preparation methods shown in reaction formulas (a) to (d), taking the preparation method shown in reaction formula (a) as an example, a more detailed description is given. The preparation method shown in reaction formula (a) indicates that in the presence of a palladium catalyst, by sequentially using Y 2 -Ar 2 and Y 3 -Ar 3 in the reaction, a cyclic azine compound (1) is obtained. Here, Y 2 -Ar 2 and Y 3 -Ar 3 used in the reaction can be used simultaneously for the reaction. Additionally, the intermediate product obtained by using Y 2 -Ar 2 in the reaction can be separated once, and then, in the presence of a palladium catalyst, by using Y 3 -Ar 3 in the reaction, the cyclic azine compound (1) can also be obtained. Additionally, by first using Y 3-Ar 3 For the reaction, cyclic azine compounds (1) can also be obtained.

[0181] Regarding the production methods shown in reaction formulas (e) and (f), the production method shown in reaction formula (e) will be described as an example. The production method shown in reaction formula (e) indicates that in the presence of a palladium catalyst, by using X 3 -Ar 3 for the reaction to obtain cyclic azine compounds (1). Additionally, the starting cyclic azine compounds used in the production methods shown in reaction formulas (e) and (f) can be produced, for example, according to International Publication No. 2017 / 025164. Commercially available products can also be used.

[0182] Among the production methods shown in these reaction formulas (a) to (f), from the perspective of high purity of the obtained cyclic azine compounds (1), the production methods shown in reaction formula (e) or (f) are preferred.

[0183] [Method for producing cyclic azine compounds]

[0184] The production method of one embodiment of the present disclosure is a method for producing a cyclic azine compound represented by formula (1), which includes a step of reacting a compound represented by formula (4) with a compound represented by formula (5):

[0185] [Chemical 19]

[0186] Reaction formula (g)

[0187]

[0188] In the formula,

[0189] Ar 1 is phenyl or 4-biphenylyl;

[0190] Ar 2 is a group represented by any one of formulas (2-1) to (2-3);

[0191] [Chemical 20]

[0192]

[0193] Ar 3 is a group represented by formula (3);

[0194] [Chemical 21]

[0195]

[0196] Ar 31 represents a hydrogen atom, or a group represented by any one of formulas (2-1) to (2-3); X 4 is a leaving group;

[0197] Y 4 is a halogen atom, a metal-containing group, or a boron-containing group.

[0198] Here, the definition of the leaving group in Formula (4) is the same as the definition of the leaving group in the above Reaction Schemes (a) to (f). Additionally, the definition of the metal-containing group or boron-containing group in Formula (5) is the same as the definition of the leaving group in the above Reaction Schemes (a) to (f).

[0199] According to the above method of the present invention, a method for manufacturing a cyclic azine compound can be provided, which can manufacture a cyclic azine compound having excellent driving voltage characteristics and current efficiency characteristics.

[0200] [Pyridine compound]

[0201] The pyridine compound of one embodiment of the present disclosure is the pyridine compound represented by Formula (5):

[0202] [Chemical Formula 22]

[0203]

[0204] In the formula, Ar 2 is a group represented by any one of Formulas (2-1) to (2-3);

[0205] [Chemical Formula 23]

[0206]

[0207] Ar 3 is a group represented by Formula (3);

[0208] [Chemical Formula 24]

[0209]

[0210] Ar 31 represents a hydrogen atom, or a group represented by any one of Formulas (2-1) to (2-3);

[0211] Y 4 is a halogen atom, a metal-containing group, or a boron-containing group.

[0212] Here, the definition of the metal-containing group or boron-containing group in Formula (5) is the same as the definition of the leaving group in the above Reaction Schemes (a) to (f).

[0213] The pyridine compound represented by Formula (5) is preferably the pyridine compound represented by Formula (5-1), (5-2), or (5-3):

[0214] [Chemical Formula 25]

[0215]

[0216] In the formula,

[0217] Ar 2 and Y 4 are synonymous with formula (5);

[0218] Ar 31 is synonymous with formula (3).

[0219] According to the present method described above, a pyridine compound can be provided, which is helpful for manufacturing a cyclic azine compound having excellent driving voltage characteristics and current efficiency characteristics.

[0220] Examples

[0221] Hereinafter, the present disclosure will be described in further detail based on examples, but the present disclosure is not construed as being limited by any of these examples.

[0222] 1 The measurement of the 1H-NMR spectrum was carried out using Gemini 200 (manufactured by Varian) or Bruker ASCEND 400 (400 MHz; manufactured by BRUKER).

[0223] Regarding the light-emitting characteristics of the organic electroluminescent element, a direct current was applied to the fabricated element at room temperature, and evaluation was carried out using a luminance meter (product name: BM-9, manufactured by TOPCON TECHNOHOUSE CORPORATION).

[0224] Synthesis Example-1

[0225] [Chemical formula 26]

[0226]

[0227] Under an argon atmosphere, 2-(4-biphenylyl)-4-phenyl-6-[5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-biphenyl-3-yl]-1,3,5-triazine (2.60 g, 4.4 mmol), 6-(2-biphenylyl)-3-chloropyridine (1.25 g, 4.9 mmol), 2 M aqueous potassium phosphate solution (6.6 mL), palladium acetate (30 mg, 0.13 mmol), and 2-dicyclohexylphosphino-2′,6′-diisopropoxybiphenyl (RuPhos, 124 mg, 0.27 mmol) were suspended in diethylene glycol dimethyl ether (diglyme, 40 mL) and stirred at 150 °C for 27 hours. After cooling, water was added to the reaction mixture, and the solid was collected by filtration and washed with water and methanol. The obtained solid was dissolved in hot toluene, and activated carbon was added for diatomaceous earth filtration. After the resulting solution was cooled to room temperature, the precipitated white solid was collected to obtain 2-(4-biphenylyl)-4-phenyl-6-{5-[6-(2-biphenylyl)-pyridin-3-yl]-biphenyl-3-yl}-1,3,5-triazine (1-6) (yield 2.62 g, 85% yield).

[0228] 1 H-

[0229] NMR(400MHz,CDCl 3 ):δ9.14(dd,J=2.3,0.7Hz,1H),9.01(dd,J=1.8,1.5Hz,2H),8.86(d,J=8.9Hz,2H),8.81(d,J=6.5Hz,2H),8.02(dd,J=1.8,1.5Hz,1H),7.84-7.86(m,2H),7.83(d,J=8.6Hz,2H),7.80(d,J=8.4Hz,2H),7.72(d,J=7.1Hz,2H),7.46-7.65(m,11H),7.43(t,J=7.3Hz,1H),7.28-7.33(m,4H),7.08-7.14(m,1H),7.06(d,J=8.1Hz,1H).

[0230] Synthesis Example-2

[0231] [Chemical formula 27]

[0232]

[0233] Under an argon atmosphere, 2M aqueous potassium phosphate solution (3.8 mL) was added to a solution of 2-(4-biphenylyl)-4-phenyl-6-[5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1,1’:4’,1”-terphenyl-3-yl]-1,3,5-triazine, 2-(2-biphenylyl)-5-chloropyridine (731 mg, 2.8 mmol), palladium acetate (17 mg, 0.075 mmol), and RuPhos (70 mg, 0.15 mmol) in diglyme (25 mL), and the mixture was stirred at 150 °C for 3 hours. After cooling to room temperature, water and methanol were added to the reaction solution, and the solid was collected by filtration and washed with water and then with methanol. The obtained solid was dried under reduced pressure and then dissolved in toluene (450 mL) under reflux. After adding activated carbon (0.4 g), the activated carbon was filtered from the suspension and washed with hot toluene (150 mL). Toluene was distilled off from the filtrate, and the obtained solid was dried and solidified under reduced pressure and then purified by recrystallization (xylene) to obtain 2-(4-biphenylyl)-4-{5-[6-(2-biphenylyl)pyridin-3-yl]-1,1’:4’,1”-terphenyl-3-yl}-6-phenyl-1,3,5-triazine (1-15) as a white solid (1.66 g, 96%).

[0234] 1 H-

[0235] NMR(CDCl 3 ): δ 9.14 (d, J = 1.7 Hz, 1H), 9.05 (dd, J = 1.5, 1.5 Hz, 1H), 9.00 (dd, J = 1.5, 1.5 Hz, 1H), 8.86 (d, J = 8.4 Hz, 2H), 8.81 (dd, J = 8.2, 1.7 Hz, 2H), 8.06 (dd, J = 1.5, 1.5 Hz, 1H), 7.88 (d, J = 8.4 Hz, 2H), 7.79 - 7.83 (m, 2H), 7.82 (d, J = 8.2 Hz, 2H), 7.79 (d, J = 8.2 Hz, 2H), 7.72 (d, J = 7.3 Hz, 2H), 7.70 (d, J = 7.3 Hz, 2H), 7.59 - 7.63 (m, 3H), 7.42 - 7.59 (m, 7H), 7.42 (dd, J = 7.3, 7.3 Hz, 1H), 7.40 (dd, J = 7.3, 7.3 Hz, 1H), 7.26 - 7.38 (m, 5H), 7.06 (d, J = 8.2 Hz, 1H).

[0236] Synthesis Example - 5

[0237] [Chemical Formula 28]

[0238]

[0239] Under an argon atmosphere, 2,4-bis(4-biphenylyl)-6-[5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-biphenyl-3-yl]-1,3,5-triazine (1.99 g, 3.0 mmol), 2-(2-biphenylyl)-3-chloropyridine (0.88 g, 3.3 mmol), palladium acetate (20 mg, 0.09 mmol), and a toluene solution of tricyclohexylphosphine (0.6 M, 0.3 mL, 0.18 mmol) were suspended in N,N-dimethylformamide (DMF, 30 mL). To this suspension was added an aqueous solution of 2M-potassium phosphate (4.5 mL), and the mixture was heated under reflux for 22 hours. After cooling, water and methanol were added to the reaction mixture, and the precipitated solid was collected by filtration. The obtained solid was purified by recrystallization (toluene) to give the target 2,4-bis(4-biphenylyl)-6-{5-[2-(2-biphenylyl)pyridin-3-yl]-biphenyl-3-yl}-1,3,5-triazine (1-50) (1.74 g, 2.3 mmol, 76%).

[0240] 1 H-NMR(CDCl 3 ): δ8.78 - 8.82(m, 6H), 7.91(s, 1H), 7.90(dd, J = 8.8, 0.9 Hz, 1H), 7.83(d, J = 8.8 Hz, 4H), 7.71 - 7.75(m, 4H), 7.52(dd, J = 7.6 Hz, 4H), 7.37 - 7.48(m, 9H), 7.15(dd, J = 7.6, 0.9 Hz, 4H), 6.99(t, J = 3.5 Hz, 1H), 6.94(dt, J = 7.3, 1.3 Hz, 1H), 6.87(t, J = 7.4 Hz, 1H), 6.55(dd, J = 8.3, 1.6 Hz, 2H)

[0241] Synthesis Example - 6

[0242] [Chemical Formula 29]

[0243]

[0244] Under an argon atmosphere, to a solution of 2,4-bis(4-biphenylyl)-6-{5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)biphenyl-3-yl}-1,3,5-triazine (5.97 g, 9.0 mmol), 2-(2-biphenylyl)-5-chloropyridine (2.63 g, 9.9 mmol), palladium acetate (61 mg, 0.27 mmol), and RuPhos (252 mg, 0.54 mmol) in diglyme (90 mL) was added 2 M aqueous potassium phosphate solution (13.5 mL), and the mixture was stirred at 150 °C for 3 hours. After cooling to room temperature, water and methanol were added to the reaction solution, and the solid was filtered off and washed with water and then with methanol. The obtained solid was dried under reduced pressure and then dissolved in toluene (500 mL) under reflux. After adding activated carbon (2.0 g), the activated carbon was filtered off from the suspension and washed with toluene (200 mL). After distilling off the low-boiling components under reduced pressure from the filtrate, purification was carried out by recrystallization (xylene) to obtain 2,4-bis(4-biphenylyl)-6-{5-[6-(2-biphenylyl)pyridin-3-yl]biphenyl-3-yl}-1,3,5-triazine (1-51) as a white solid (4.76 g, 69%).

[0245] 1 H-

[0246] NMR(CDCl 3 ): δ 9.13 (d, J = 1.8 Hz, 1H), 9.02 (dd, J = 1.6, 1.6 Hz, 1H), 9.00 (dd, J = 1.6, 1.6 Hz, 1H), 8.86 (d, J = 8.4 Hz, 4H), 8.01 (dd, J = 1.6, 1.6 Hz, 1H), 7.88 - 7.80 (m, 2H), 7.82 (d, J = 8.4 Hz, 4H), 7.80 (d, J = 7.2 Hz, 2H), 7.72 (d, J = 7.2 Hz, 4H), 7.56 (dd, J = 7.3, 7.3 Hz, 2H), 7.47 - 7.54 (m, 3H), 7.51 (dd, J = 7.3, 7.3 Hz, 4H), 7.47 (d, J = 7.5 Hz, 1H), 7.42 (dd, J = 7.3, 7.3 Hz, 2H), 7.26 - 7.36 (m, 5H), 7.05 (d, J = 8.1 Hz, 1H).

[0247] Synthesis Example - 9

[0248] [Chemical Formula 30]

[0249]

[0250] Under an argon atmosphere, 2,4-bis(4-biphenylyl)-6-{5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1,1’:2’,1”-terphenyl-3-yl}-1,3,5-triazine (2.22 g, 3.0 mmol), 4-chloro-3-phenylpyridine (853 mg, 4.5 mmol) and palladium acetate (14 mg, 0.06 mmol) were suspended in DMF (30 mL). To this suspension was added a toluene solution of tricyclohexylphosphine (0.6 M, 0.2 mL, 0.12 mmol) and 2 M potassium phosphate (4.5 mL), and the mixture was stirred overnight at 130 °C. After cooling to room temperature, water and methanol were added, and the precipitated solid was filtered off, washed with water and then with methanol, and the low-boiling components were removed by distillation under reduced pressure. The resulting solid was purified by column chromatography (hexane:chloroform = 3:1) and then by recrystallization from toluene to obtain the target 2,4-bis(4-biphenylyl)-6-{5-(3-phenylpyridin-4-yl)-1,1’:2’,1”-terphenyl-3-yl}-1,3,5-triazine (1-65) (1.49 g, 64%).

[0251] 1 H-NMR(CDCl 3 ): δ8.69 - 8.71(m, 5H), 8.62(d, J = 5.0 Hz, 1H), 8.52(t, J = 1.6 Hz, 1H), 8.36(t, J = 1.6 Hz, 1H), 7.80(d, J = 8.5 Hz, 4H), 7.72(dd, J = 7.1, 1.4 Hz, 4H), 7.41 - 7.54(m, 9H), 7.21 - 7.39(m, 12H), 7.12(d, J = 4.6 Hz, 1H).

[0252] Synthesis Example - 10

[0253] [Chemical Formula 31]

[0254]

[0255] Under a nitrogen atmosphere, 2,4-bis(4-biphenylyl)-6-{5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1,1’:2’,1”-terphenyl-3-yl}-1,3,5-triazine (85 g, 115 mmol), 4-bromopyridine hydrochloride (33.5 g, 172 mmol) and tetrakis(triphenylphosphine)palladium(0) (5.3 g, 4.6 mmol) were suspended in THF (1.15 L). To this suspension was added an aqueous solution of 2M-potassium phosphate (345 mL), and the mixture was heated under reflux for 5 hours. After cooling, water and methanol were added, and the precipitate was filtered. The filtrate was purified by recrystallization using toluene to obtain the target 2,4-bis(4-biphenylyl)-6-{5-(4-pyridyl)-1,1’:2’,1”-terphenyl-3-yl}-1,3,5-triazine (1-64) (59.8 g, 75%).

[0256] Synthesis Example-11

[0257] [Chemical Formula 32]

[0258]

[0259] Under an argon atmosphere, 2,4-bis(4-biphenylyl)-6-[3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-5-(4-pyridyl)phenyl]-1,3,5-triazine (3.00 g, 4.5 mmol), 1-bromo-4-phenylnaphthalene (1.66 g, 5.9 mmol) and tetrakis(triphenylphosphine)palladium(0) (156 mg, 0.13 mmol) were suspended in THF (45 mL). To this suspension was added an aqueous solution of 2M-potassium carbonate (6.7 mL), and the mixture was heated under reflux for 22 hours. After cooling, water and methanol were added to the reaction mixture, and the precipitated solid was filtered. The obtained solid was purified by recrystallization (toluene) to thereby obtain the target 2,4-bis(4-biphenylyl)-6-[3-(4-phenylnaphthalen-1-yl)-5-(4-pyridyl)phenyl]-1,3,5-triazine (1-73) (2.67 g, 80%).

[0260] 1 H-

[0261] NMR(CDCl 3)δ9.17(t, J = 1.6 Hz, 1H), 9.05(t, J = 1.6 Hz, 1H), 8.87(dt, J = 8.6, 1.8 Hz, 4H), 8.78(dd, J = 4.6, 1.6 Hz, 2H), 8.04 - 8.07(m, 3H), 7.82(dt, J = 8.6, 1.8 Hz, 4H), 7.77(dd, J = 4.6, 1.6 Hz, 2H), 7.71(dt, J = 7.0, 2.0 Hz, 4H), 7.68(d, J = 7.2 Hz, 1H), 7.47 - 7.62(m, 12H), 7.42(tt, J = 7.3, 2.1 Hz, 2H).

[0262] Synthesis Example - 12

[0263] [Chemical Formula 33]

[0264]

[0265] Under an argon atmosphere, 2,4 - bis(4 - biphenylyl)-6-[3-(4,4,5,5 - tetramethyl - 1,3,2 - dioxaborolan - 2 - yl)-5-(4 - pyridyl)phenyl]-1,3,5 - triazine (3.50 g, 5.3 mmol), 6 - phenyl - 2 - trifluoromethanesulfonyloxynaphthalene (2.41 g, 6.8 mmol), palladium acetate (60 mg, 0.27 mmol), and 2 - dicyclohexylphosphino - 2′,4′,6′ - triisopropylbiphenyl (XPhos, 252 mg, 0.53 mmol) were suspended in THF (55 mL). To this suspension was added an aqueous 2M - potassium carbonate solution (7.7 mL), and the mixture was heated under reflux for 15 hours. After cooling to room temperature, water and methanol were added to the reaction mixture, and the precipitated solid was filtered off. The obtained solid was purified by recrystallization (toluene) to give the target 2,4 - bis(4 - biphenylyl)-6-[3-(6 - phenyl - naphthalen - 2 - yl)-5-(4 - pyridyl)phenyl]-1,3,5 - triazine (1 - 92) (3.21 g, 4.3 mmol, 83%).

[0266] 1 H -

[0267] NMR(CDCl 3): δ 9.22 (t, 1.5 Hz, 1H), 9.08 (t, 1.5 Hz, 1H), 8.91 (d, J = 8.4 Hz, 4H), 8.81 (dd, J = 3.1, 1.5 Hz, 2H), 8.29 (s, 1H), 8.23 (t, J = 1.5 Hz, 1H), 8.15 (s, 1H), 8.10 (t, J = 8.3 Hz, 2H), 7.98 (dt, J = 8.9, 1.7 Hz, 1H), 7.86 (dt, J = 8.3, 1.9 Hz, 4H), 7.78 (t, J = 6.3 Hz, 4H), 7.73 (dd, J = 8.4, 1.4 Hz, 4H) 7.56 - 7.50 (m, 7H), 7.46 - 7.41 (m, 3H).

[0268] Synthesis Example - 13

[0269] [Chemical Formula 34]

[0270]

[0271] Under a nitrogen atmosphere, 3 - bromo - 5 - chlorobiphenyl (50 g, 186.9 mmol), 3 - (4,4,5,5 - tetramethyl - 1,3,2 - dioxaborolan - 2 - yl) - 2 - phenylpyridine (63 g, 224.3 mmol), and tetrakis(triphenylphosphine)palladium (4.3 g, 3.7 mmol) were suspended in THF (370 mL) at 60 °C. To this suspension, 4 M potassium phosphate (140 mL) was added, and the mixture was heated under reflux for 10 hours. After cooling to room temperature, toluene was added to the reaction mixture, and the organic layer was extracted. Magnesium sulfate and activated carbon were added to the organic layer, and the insoluble components were filtered out. The filtrate was concentrated and then purified by recrystallization from ethanol to obtain the target 3 - chloro - 5 - (2 - phenylpyridin - 3 - yl)biphenyl (5 - 1) (45.5 g, 71%).

[0272] 1 H -

[0273] NMR(CDCl 3 ): δ 8.73 (dd, 4.8, 1.7 Hz, 1H), 7.79 (dd, t.t, 1.7 Hz, 1H), 7.46 (t, 1.8 Hz, 1H), 7.42 - 7.30 (m, 9H), 7.27 (d, 1.8 Hz, 1H), 7.25 - 7.24 (m, 2H), 7.18 (t, 1.6 Hz, 1H).

[0274] Under a nitrogen atmosphere, compound 5-1 (197.8 g, 578.7 mmol), bis(pinacolato)diboron (154.3 g, 607.7 mmol), and potassium acetate (170.4 g, 1736 mmol) were suspended in THF (1.16 L) at 60 °C. A THF solution (30 mL) of palladium(II) acetate (1.3 g, 5.8 mmol) and 2-dicyclohexylphosphino-2′,4′,6′-triisopropylbiphenyl (XPhos, 5.5 mg, 11.6 mmol) was added to the suspension, and the mixture was heated under reflux for 6 hours. After cooling to room temperature, activated carbon was added to the reaction mixture and stirred, and the insoluble components were filtered off. The filtrate was concentrated and purified by recrystallization from hexane to obtain the target 3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-5-(2-phenylpyridin-3-yl)biphenyl (5-2) (178 g, 71%).

[0275] 1 H-

[0276] NMR(CDCl 3 ): δ8.70 (dd, 4.8, 1.7 Hz, 1H), 7.92 (dd, 1.8, 1.0 Hz, 1H), 7.86 (dd, 7.7, 1.7 Hz, 1H), 7.79 (dd, 1.8, 1.0 Hz, 1H), 7.41 - 7.38 (m, 2H), 7.36 - 7.27 (m, 8H), 7.23 - 7.21 (m, 2H), 1.36 (s, 12H).

[0277] Synthesis Example - 14

[0278] [Chemical Formula 35]

[0279]

[0280] Under a nitrogen atmosphere, 2-chloro-4,6-bis(4-biphenylyl)-1,3,5-triazine (176.2 g, 420 mmol), compound 5-2 (200 g, 462 mmol), and tetrakis(triphenylphosphine)palladium(0) (4.9 g, 4.2 mmol) were suspended in THF (4.2 L). A 2 M aqueous potassium phosphate solution (0.6 L) was added to the suspension, and the mixture was heated under reflux for 6 hours. After cooling to room temperature, methanol was added, and the precipitate was filtered. The filtrate and activated carbon were suspended in toluene at 80 °C, and the insoluble components were filtered off. The filtrate was concentrated and purified by recrystallization from toluene to obtain the target 4,6-bis(4-biphenylyl)-2-[5-(2-phenylpyridin-3-yl)biphenyl-3-yl]-1,3,5-triazine (1-48) (182 g, 63%).

[0281] 1 H-

[0282] NMR(CDCl 3 ): δ 9.02 (t, 1.6 Jz, 1H), 8.90 (d, 8.6 Hz, 4H), 8.80 (t, 1.6 Hz, 1H), 8.77 (dd, 4.7, 1.7 Hz, 1H), 8.09 (dd, 7.7, 1.7 Hz, 1H), 7.93 (d, 8.6 Hz, 4H), 7.82 (d, 8.2 Hz, 4H), 7.77 (t, 1.8 Hz, 1H), 7.62 - 7.32 (m, 16H), 7.29 (tt, 7.3, 1.4 Hz, 1H).

[0283] Synthesis Example - 15

[0284] [Chemical Formula 36]

[0285]

[0286] Under an argon atmosphere, 4,6 - bis(4 - biphenylyl) - 2 - {3 - (4,4,5,5 - tetramethyl - 1,3,2 - dioxaborolan - 2 - yl)biphenyl - 5 - yl} - 1,3,5 - triazine (3.0 g, 4.52 mmol), 2 - chloro - 3 - phenylpyridine (943 mg, 4.97 mmol), palladium(II) acetate (51 mg, 0.23 mmol), and 2 - dicyclohexylphosphino - 2′,6′ - diisopropoxybiphenyl (202 mg, 0.45 mmol) were suspended in THF (46 mL). After adding 2.0 M aqueous potassium phosphate solution (7 mL) to this suspension, the mixture was heated under reflux for 24 hours. After cooling, water and methanol were added to the reaction mixture. The resulting solid was collected by filtration and washed with hexane to obtain the target 4,6 - bis(4 - biphenylyl) - 2 - {5 - (3 - phenyl - pyridin - 2 - yl)biphenyl - 3 - yl} - 1,3,5 - triazine (1 - 54) (2.92 g, 4.23 mmol, 94%).

[0287] 1 H - NMR(CDCl 3 ) δ 7.36 - 7.55 (m, 17H), 7.01 - 7.75 (m, 4H), 7.80 - 7.88 (m, 6H), 8.79 - 8.84 (m, 5H), 8.87 (dd, J = 1.6, 1.5 Hz, 1H), 8.93 (dd, J = 1.7, 1.6 Hz, 1H).

[0288] In addition, for the cyclic azine compounds represented by Formula (1 - 49), (1 - 52), (1 - 66), (1 - 67), and (1 - 71), they were synthesized by the same method as the manufacturing methods shown in Synthesis Examples - 1 to 15.

[0289] The structural formulas and abbreviations of the compounds used in the fabrication and performance evaluation of an organic electroluminescent device composed of a cyclic azine compound (1) are shown below.

[0290] [Chemical formula 37]

[0291]

[0292] Element Example - 1 (Reference Figure 2 )(Preparation of Substrate 101 and Anode 102)

[0293] As a substrate having an anode on its surface, a glass substrate with an ITO transparent electrode in which a 2 - mm - wide indium tin oxide (ITO) film (film thickness: 110 nm) was patterned into stripes was prepared. Then, after cleaning this substrate with isopropyl alcohol, surface treatment was performed by ozone - ultraviolet cleaning.

[0294] (Preparation for Vacuum Evaporation)

[0295] On the substrate that had undergone the surface treatment after cleaning, vacuum evaporation of each layer was performed by the vacuum evaporation method to form each layer by lamination.

[0296] First, the above - mentioned glass substrate was introduced into the vacuum evaporation chamber, and the pressure was reduced to 1.0×10 -4 Pa. Then, fabrication was carried out according to the film - forming conditions of each layer in the following order.

[0297] (Fabrication of Hole - Injection Layer 103)

[0298] The sublimation - purified HTL and NDP - 9 were formed into a 10 - nm film at a rate of 0.15 nm / second to fabricate the hole - injection layer 103.

[0299] (Fabrication of First Hole - Transport Layer 1051)

[0300] The sublimation - purified HTL was formed into an 85 - nm film at a rate of 0.15 nm / second to fabricate the first hole - transport layer 1051.

[0301] (Fabrication of Second Hole - Transport Layer 1052)

[0302] The sublimation - purified EBL - 3 was formed into a 5 - nm film at a rate of 0.15 nm / second to fabricate the second hole - transport layer 1052.

[0303] (Fabrication of Light - Emitting Layer 106)

[0304] The sublimation - purified BH - 1 and BD - 2 were formed into a 20 - nm film at a ratio of 95:5 (mass ratio) to fabricate the light - emitting layer 106. The film - forming rate was 0.18 nm / second.

[0305] (Fabrication of the first electron transport layer 1071)

[0306] The sublimated and purified HBL-1 was formed into a 6-nm film at a rate of 0.05 nm per second to fabricate the first electron transport layer 1071.

[0307] (Fabrication of the second electron transport layer 1072)

[0308] Compound 1-48 and Liq were formed into a 25-nm film at a ratio of 50:50 (mass ratio) to fabricate the second electron transport layer 1072. The film-forming rate was 0.15 nm per second.

[0309] (Fabrication of the cathode 108)

[0310] Finally, a metal mask was arranged in a manner orthogonal to the ITO stripes on the substrate, and the cathode 108 was formed. Regarding the cathode, silver / magnesium (mass ratio 1 / 10) and silver were respectively formed into films of 80 nm and 20 nm in this order to form a two-layer structure. The film-forming rate of silver / magnesium was 0.5 nm per second, and the film-forming rate of silver was 0.2 nm per second.

[0311] Thus, the Figure 2 shown organic electroluminescent element 100 with a light-emitting area of 4 mm 2 was fabricated. It should be noted that the respective film thicknesses were measured by a stylus profilometer (DEKTAK, manufactured by Bruker).

[0312] Furthermore, the element was sealed in a nitrogen atmosphere glove box with an oxygen and moisture concentration of 1 ppm or less. Sealing was performed using a bisphenol F-type epoxy resin (manufactured by Nagase chemteX) for the glass sealing cap and the film-forming substrate (element).

[0313] A direct current was applied to the organic electroluminescent element fabricated as described above, and the luminescence characteristics were evaluated using a luminance meter (product name: BM-9, manufactured by TOPCON TECHNOHOUSE CORPORATION). As the luminescence characteristics, the current efficiency (cd / A) at a current density of 10 mA / cm 2 was measured. It should be noted that the driving voltage is a relative value when the result in Element Reference Example 3 described later is used as a reference value (100). The obtained measurement results are shown in Table 4.

[0314] Element Comparative Example - 1

[0315] In Element Example - 1, ETL-1 was used instead of Compound 1-48, and an organic electroluminescent element was fabricated and evaluated in the same manner as in Element Example - 1. The obtained measurement results are shown in Table 4.

[0316] Element Reference Example - 1

[0317] In Element Example - 1, ETL - 2 described in Patent Document 1 was used to replace Compound 1 - 48. Other than that, an organic electroluminescent element was fabricated and evaluated in the same manner as in Element Example - 1. The obtained measurement results are shown in Table 4.

[0318] Element Reference Example - 2

[0319] In Element Example - 1, ETL - 3 described in Patent Document 1 was used to replace Compound 1 - 48. Other than that, an organic electroluminescent element was fabricated and evaluated in the same manner as in Element Example - 1. The obtained measurement results are shown in Table 4.

[0320] Element Reference Example - 3

[0321] In Element Example - 1, ETL - 4 described in Japanese Patent Application Laid - Open No. 2017 - 105717 was used to replace Compound 1 - 48. Other than that, an organic electroluminescent element was fabricated and evaluated in the same manner as in Element Example - 1. The obtained measurement results are shown in Table 4.

[0322] [Table 4]

[0323] Compound Driving voltage Current efficiency Element Example-1 1-48 98 104 Element Comparative Example-1 ETL-1 100 89 Element Reference Example-1 ETL-2 100 95 Element Reference Example-2 ETL-3 103 96 Element Reference Example-3 ETL-4 100 100

[0324] Element Example - 2 (Reference Figure 3 )

[0325] (Preparation of Substrate 101 and Anode 102)

[0326] As the substrate having an anode on its surface, a glass substrate with an ITO transparent electrode in which a 2 - mm - wide indium tin oxide (ITO) film (film thickness: 110 nm) was patterned into stripes was prepared. Then, the substrate was cleaned with isopropyl alcohol and subjected to surface treatment by ozone - ultraviolet cleaning.

[0327] (Preparation for Vacuum Deposition)

[0328] On the substrate that had been subjected to surface treatment after cleaning, each layer was formed by vacuum deposition through a vacuum deposition method.

[0329] First, the above - mentioned glass substrate was introduced into the vacuum deposition chamber, and the pressure was reduced to 1.0×10 -4 Pa. Then, fabrication was carried out according to the film - forming conditions for each layer in the following order.

[0330] (Fabrication of Hole - Injection Layer 103)

[0331] The sublimation-purified HIL was formed into a 50-nm film at a rate of 0.15 nm / second to fabricate the hole injection layer 103.

[0332] (Fabrication of the charge generation layer 104)

[0333] The sublimation-purified HAT-CN was formed into a 5-nm film at a rate of 0.15 nm / second to fabricate the charge generation layer 104.

[0334] (Fabrication of the first hole transport layer 1051)

[0335] The sublimation-purified HTL was formed into a 10-nm film at a rate of 0.15 nm / second to fabricate the first hole transport layer 1051.

[0336] (Fabrication of the second hole transport layer 1052)

[0337] The sublimation-purified EBL-2 was formed into a 5-nm film at a rate of 0.15 nm / second to fabricate the second hole transport layer 1052.

[0338] (Fabrication of the light-emitting layer 106)

[0339] The sublimation-purified BH-2 and BD-1 were formed into a 25-nm film at a ratio of 95:5 (mass ratio) to fabricate the light-emitting layer 106. The film-forming rate was 0.18 nm / second.

[0340] (Fabrication of the first electron transport layer 1071)

[0341] The sublimation-purified HBL-2 was formed into a 5-nm film at a rate of 0.05 nm / second to fabricate the first electron transport layer 1071.

[0342] (Fabrication of the second electron transport layer 1072)

[0343] Compound 1-48 and Liq were formed into a 25-nm film at a ratio of 50:50 (mass ratio) to fabricate the second electron transport layer 1072. The film-forming rate was 0.15 nm / second.

[0344] (Fabrication of the cathode 108)

[0345] Finally, a metal mask was arranged in a manner orthogonal to the ITO stripes on the substrate, and the cathode 108 was formed by film deposition. Regarding the cathode, silver / magnesium (mass ratio 1 / 10) and silver were respectively formed into films of 80 nm and 20 nm in this order to form a two-layer structure. The film-forming rate of silver / magnesium was 0.5 nm / second, and the film-forming rate of silver was 0.2 nm / second.

[0346] Thus, the Figure 3 shown light-emitting area of 4 mm 2The organic electroluminescent element 100. It should be noted that the respective film thicknesses were measured using a stylus film thickness gauge (DEKTAK, manufactured by Bruker).

[0347] Furthermore, the element was sealed in a nitrogen atmosphere glove box with an oxygen and moisture concentration of 1 ppm or less. Sealing was performed using a bisphenol F type epoxy resin (manufactured by Nagase chemteX) for a glass sealing cap and a film-forming substrate (element).

[0348] A direct current was applied to the organic electroluminescent element fabricated as described above, and the luminescence characteristics were evaluated using a luminance meter (product name: BM-9, manufactured by TOPCON TECHNOHOUSE CORPORATION). As the luminescence characteristics, the current efficiency (cd / A) at a current density of 10 mA / cm 2 was measured. It should be noted that the driving voltage is a relative value when the result in Element Reference Example 4 described later is used as a reference value (100). The obtained measurement results are shown in Table 5.

[0349] Element Example-3

[0350] In Element Example-2, Compound 1-49 was used instead of Compound 1-48, and an organic electroluminescent element was fabricated and evaluated in the same manner as in Element Example-2. The obtained measurement results are shown in Table 5.

[0351] Element Example-4

[0352] In Element Example-2, Compound 1-50 synthesized in Synthesis Example-5 was used instead of Compound 1-48, and an organic electroluminescent element was fabricated and evaluated in the same manner as in Element Example-2. The obtained measurement results are shown in Table 5.

[0353] Element Example-5

[0354] In Element Example-2, Compound 1-51 synthesized in Synthesis Example-6 was used instead of Compound 1-48, and an organic electroluminescent element was fabricated and evaluated in the same manner as in Element Example-2. The obtained measurement results are shown in Table 5.

[0355] Element Example-6

[0356] In Element Example-2, Compound 1-52 was used instead of Compound 1-48, and an organic electroluminescent element was fabricated and evaluated in the same manner as in Element Example-2. The obtained measurement results are shown in Table 5.

[0357] Element Example-7

[0358] In Component Example - 2, Compound 1 - 64 was used instead of Compound 1 - 48. Other than that, an organic electroluminescent element was fabricated and evaluated by the same method as in Component Example - 2. The obtained measurement results are shown in Table 5.

[0359] Component Example - 8

[0360] In Component Example - 2, Compound 1 - 65 was used to replace Compound 1 - 48. Other than that, an organic electroluminescent element was fabricated and evaluated by the same method as in Component Example - 2. The obtained measurement results are shown in Table 5.

[0361] Component Reference Example - 4

[0362] In Component Example - 2, ETL - 4 described in Japanese Patent Application Laid - Open No. 2017 - 105717 was used instead of Compound 1 - 48. Other than that, an organic electroluminescent element was fabricated and evaluated by the same method as in Component Example - 2. The obtained measurement results are shown in Table 5.

[0363] [Table 5]

[0364] Compound Driving voltage Current efficiency Element Example-2 1-48 98 110 Element Example-3 1-49 99 115 Element Example-4 1-50 97 101 Element Example-5 1-51 97 106 Element Example-6 1-52 96 104 Element Example-7 1-64 97 109 Element Example-8 1-65 97 110 Element Reference Example-4 ETL-4 100 100

[0365] Component Example - 9

[0366] In Component Example - 1, EBL - 4 was used instead of EBL - 3, BD - 3 was used instead of BD - 2, and Compound 1 - 67 was used instead of Compound 1 - 48. As the cathode, ytterbium, silver / magnesium (mass ratio 9 / 1), and silver were respectively formed into films with thicknesses of 2 nm, 12 nm, and 90 nm in this order to form a three - layer structure. Other than that, an organic electroluminescent element was fabricated and evaluated by the same method as in Component Example - 1. Here, the film - forming rate of ytterbium was 0.02 nm / second, the film - forming rate of silver / magnesium was 0.5 nm / second, and the film - forming rate of silver was 0.2 nm / second. The obtained measurement results are shown in Table 6.

[0367] Component Reference Example - 5

[0368] In Component Example - 9, ETL - 4 was used instead of Compound 1 - 67. Other than that, an organic electroluminescent element was fabricated and evaluated by the same method as in Component Example - 9. The obtained measurement results are shown in Table 6.

[0369] [Table 6]

[0370]

[0371] Component Example - 10

[0372] In Element Example-1, EBL-4 was used instead of EBL-3, and BD-3 was used instead of BD-2. As the cathode, ytterbium, silver / magnesium (mass ratio 9 / 1), and silver were respectively formed into films with thicknesses of 2 nm, 12 nm, and 90 nm in this order to form a three-layer structure. Except for this, an organic electroluminescent element was fabricated in the same manner as in Element Example-1 and evaluated. Here, the film formation rate of ytterbium was 0.02 nm / second, the film formation rate of silver / magnesium was 0.5 nm / second, and the film formation rate of silver was 0.2 nm / second. The obtained measurement results are shown in Table 7.

[0373] Element Example-11

[0374] In Element Example-10, Compound 1-66 was used instead of Compound 1-48. Except for this, an organic electroluminescent element was fabricated and evaluated in the same manner as in Element Example-10. The obtained measurement results are shown in Table 7.

[0375] Element Example-12

[0376] In Element Example-10, Compound 1-62 was used instead of Compound 1-48. Except for this, an organic electroluminescent element was fabricated and evaluated in the same manner as in Element Example-10. The obtained measurement results are shown in Table 7.

[0377] Element Comparative Example-2

[0378] In Element Example-10, ETL-1 was used instead of Compound 1-48. Except for this, an organic electroluminescent element was fabricated and evaluated in the same manner as in Element Example-10. The obtained measurement results are shown in Table 7.

[0379] [Table 7]

[0380] Compound Driving voltage Current efficiency Element Example-10 1-48 97 105 Element Example-11 1-66 96 108 Element Example-12 1-62 97 108 Element Comparative Example-2 ETL-1 100 100

[0381] According to Tables 4 to 7, compared with the conventionally known cyclic azine compounds, the cyclic azine compound (1) of one embodiment of the present disclosure can provide an organic electroluminescent element having both excellent driving voltage characteristics and current efficiency characteristics.

[0382] In addition, the cyclic azine compound (1) of one embodiment of the present disclosure is used as an electron transport material for an organic electroluminescent element having both excellent driving voltage characteristics and current efficiency characteristics. Furthermore, based on the cyclic azine compound (1), an organic electroluminescent element with low power consumption can be provided.

[0383] In addition, a thin film composed of the cyclic azine compound (1) according to one embodiment of the present disclosure is useful as a material for an organic electroluminescent element because of its excellent electron transport ability, hole blocking ability, redox resistance, water resistance, oxygen resistance, electron injection characteristics, etc., and is useful as an electron transport material, a hole blocking material, a light-emitting host material, etc. In particular, it is useful when used as an electron transport material.

[0384] In addition, the cyclic azine compound (1) according to one embodiment of the present disclosure has a wide band gap and a high triplet excitation energy level, and thus can be applied not only to conventional fluorescent element applications but also to organic electroluminescent elements using phosphorescent elements and thermally activated delayed fluorescence (TADF).

[0385] Although the present invention has been described in detail with reference to specific embodiments, it is obvious to those skilled in the art that various changes or modifications can be made without departing from the essence and scope of the present invention.

[0386] It should be noted that the entire contents of the specification, claims, drawings, and abstract of Japanese Patent Application No. 2019-139746 filed on July 30, 2019 are incorporated herein by reference as the disclosure of the specification of the present invention.

[0387] Symbol Explanation

[0388] 1, 101 Substrate

[0389] 2, 102 Anode

[0390] 3, 103 Hole Injection Layer

[0391] 4, 104 Charge Generation Layer

[0392] 5, 105 Hole Transport Layer

[0393] 6, 106 Light-Emitting Layer

[0394] 7, 107 Electron Transport Layer

[0395] 8, 108 Cathode

[0396] 51, 1051 First Hole Transport Layer

[0397] 52, 1052 Second Hole Transport Layer

[0398] 71, 1071 First Electron Transport Layer

[0399] 72, 1072 Second Electron Transport Layer

[0400] 100 Organic Electroluminescent Element

Claims

1. A cyclic azine compound represented by formula (1), wherein, in formula (1), Ar 1 is phenyl or 4-biphenylyl; Ar 2 is a group represented by formula (2-2b); Ar 3 is a group represented by formula (3); in formula (3), Ar 31 is a hydrogen atom or a group represented by any one of formulas (2-1) to (2-3).

2. The cyclic azine compound according to claim 1, wherein, Ar 3 is a group represented by any one of formulas (3-1) to (3-9), [Chemical formula 5] 3. The cyclic azine compound according to claim 1 or 2, wherein, the cyclic azine compound is a cyclic azine compound represented by formula (1-65), (1-66), (1-67) or (1-71); 4. A material for an organic electroluminescent element, which comprises the cyclic azine compound according to any one of claims 1 to 3.

5. An electron transport material for an organic electroluminescent element, which comprises the cyclic azine compound according to any one of claims 1 to 3.

6. An organic electroluminescent element, which comprises the cyclic azine compound according to any one of claims 1 to 3.

7. A method for producing a cyclic azine compound represented by formula (1), which comprises reacting a compound represented by formula (4) with a compound represented by formula (5); Reaction formula (g) wherein, Ar 1 is phenyl or 4-biphenylyl; Ar 2 is a group represented by formula (2-2b); Ar 3 is a group represented by formula (3); Ar 31 represents a hydrogen atom or a group represented by any one of formulas (2-1) to (2-3); X 4 is a leaving group; Y 4 is a halogen atom, a metal-containing group, or a boron-containing group.

8. A pyridine compound represented by formula (5), wherein, [Chemical formula 10] In formula (5), Ar 2 is the group represented by formula (2-2b); Ar 3 is a group represented by formula (3); Ar 31 represents a hydrogen atom or a group represented by any one of formulas (2-1) to (2-3); Y 4 is a halogen atom, a metal-containing group, or a boron-containing group.

9. The pyridine compound according to claim 8, wherein, the pyridine compound is represented by formula (5-1), (5-2) or (5-3); wherein, Ar 2 and Y 4 are synonymous with formula (5); Ar 31 Is synonymous with formula (3).

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