Heterocyclic compounds, organic electroluminescent elements, and electronic devices

Abstract

[Problem] The purpose of the present invention is to provide a compound that has a high refractive index with respect to the wavelength range of 450-750 nm in a capping layer, in order to improve the light extraction efficiency of an organic EL element. [Solution] According to the present invention, attention was paid to the fact that heterocyclic compounds have excellent thin film stability and durability, and the refractive index can be improved by adjustment of a molecular structure. By designing a molecule and using the molecule as a material for a capping layer, an organic EL element having excellent emission efficiency has been obtained.

Description

[Technical Field]

[0001] The present invention relates to a heterocyclic compound suitable for a self-luminous electronic element, particularly an organic electroluminescent element (hereinafter abbreviated as organic EL element), suitable for various display devices, or an electronic device, and to an organic EL element or an electronic device using the heterocyclic compound. [Background technology]

[0002] In 1987, C.W. Tang and his colleagues at Eastman Kodak Company made organic EL devices practical by developing a layered structure element in which various roles are assigned to each material. They layered a phosphor that can transport electrons and an organic material that can transport holes, and by injecting both charges into the phosphor layer to emit light, they achieved a brightness of 1000 cd / m at a voltage of 10 V or less. 2 Such high brightness has become possible (see Patent Documents 1 and 2).

[0003] To date, many improvements have been made to the practical application of organic EL elements, and the various roles of the laminated structure have been further subdivided. In electroluminescent elements in which an anode, a hole injection layer, a hole transport layer, an emitting layer, an electron transport layer, an electron injection layer, and a cathode are sequentially provided on a substrate, high efficiency and durability have been achieved by light-emitting elements with a bottom emission structure that emits light from the bottom (see, for example, Non-Patent Document 1).

[0004] In recent years, light-emitting devices with a top-emission structure that uses a metal with a high work function as the anode and emits light from the top have come into use. In a bottom-emission structure in which light is extracted from the bottom where the pixel circuit is located, the area of ​​the light-emitting section is limited, whereas a light-emitting device with a top-emission structure has the advantage of being able to extract light from the top and not be obstructed by the pixel circuit, allowing for a larger light-emitting section. Light-emitting devices with a top-emission structure use semi-transparent electrodes such as LiF / Al / Ag (see, for example, Non-Patent Document 2), Ca / Mg (see, for example, Non-Patent Document 3), or LiF / MgAg as the cathode.

[0005] In such light-emitting devices, when light emitted from the light-emitting layer is incident on another film at an angle greater than a certain level, it is totally reflected at the interface between the light-emitting layer and the other film. As a result, only a portion of the emitted light can be utilized. In recent years, light-emitting devices have been proposed in which a "capping layer" with a high refractive index is provided on the outside of a semi-transparent electrode with a low refractive index in order to improve the light extraction efficiency (see, for example, Non-Patent Documents 2 and 3).

[0006] The effect of the capping layer on a top-emission light-emitting device using Ir(ppy)3 as the light-emitting material was such that, while the current efficiency was 38 cd / A without the capping layer, the efficiency was improved by approximately 1.7 times to 64 cd / A in a light-emitting device using a 60 nm-thick ZnSe capping layer. It has also been shown that the maximum transmittance of the semi-transparent electrode and capping layer does not necessarily coincide with the maximum efficiency, and that the maximum light extraction efficiency is determined by the interference effect (see, for example, Non-Patent Document 3).

[0007] Conventionally, the use of high-resolution metal masks has been proposed for forming capping layers, but there is a problem in that the metal masks can become distorted by heat when used under high-temperature conditions, resulting in reduced alignment accuracy. ZnSe has a high melting point of 1100°C or higher (see, for example, Non-Patent Document 3), making it impossible to deposit it in the correct position using a high-resolution metal mask, which may affect the light-emitting element itself. Furthermore, even when deposited by sputtering, this affects the light-emitting element, so capping layers made of inorganic materials are not suitable for use.

[0008] In addition, when tris(8-hydroxyquinoline)aluminum (Alq3) is used as a capping layer to adjust the refractive index (see, for example, Non-Patent Document 2), Alq3 is known as an organic EL material that is generally used as a green emitting material or electron transport material. However, since it has weak absorption around 450 nm, which is used as a blue emitting material, there are problems with blue light emitting devices in that it reduces color purity and light extraction efficiency.

[0009] To improve the device characteristics of organic EL devices and significantly increase light extraction efficiency, materials for the capping layer are required that have a high refractive index, a low extinction coefficient, and excellent thin film stability and durability. [Prior art documents] [Patent documents]

[0010] [Patent Document 1] Japanese Patent Application Publication No. 8-048656 [Patent Document 2] Patent No. 3194657 [Non-patent literature]

[0011] [Non-Patent Document 1] Proceedings of the 9th Seminar of the Japan Society of Applied Physics, pp. 55-61 (2001) [Non-patent document 2] Appl.Phys.Lett.,78,544(2001) [Non-patent document 3] Appl.Phys.Lett.,82,466(2003) Summary of the Invention [Problem to be solved by the invention]

[0012] An object of the present invention is to provide a compound that has a high refractive index in the wavelength range of 450 nm to 750 nm for light transmitted through a capping layer (organic thin film) of an organic EL device and has no absorption around 450 nm, and to provide an organic EL device, or an electronic device or electronic device that uses the compound to improve light extraction efficiency.

[0013] The physical properties of the compound constituting the capping layer (organic thin film) suitable for the present invention include (1) a high refractive index, (2) the ability to be vapor-deposited, (3) a stable thin film state, and (4) a high glass transition temperature. The physical properties of the element suitable for the present invention include (1) a high light extraction efficiency, (2) no reduction in color purity, (3) light transmission without change over time, and (4) a long life. [Means for solving the problem]

[0014] In order to achieve the above object, the present inventors focused on the fact that heterocyclic compounds have excellent thin film stability and durability and that the refractive index can be improved by adjusting the molecular structure, designed a molecule, fabricated an organic EL device using the heterocyclic compound as a material constituting a capping layer, and thoroughly evaluated the characteristics of the device, which resulted in the completion of the present invention.

[0015] That is, according to the present invention, the following heterocyclic compounds and organic EL devices are provided.

[0016] 1) A heterocyclic compound represented by the following general formula (1):

[0017] [ka] (1)

[0018] ( During the ceremonyX1 and X2 may be the same or different and represent a nitrogen atom or a CH group, with at least one being a nitrogen atom. L1 and L2 may be the same or different and represent a single bond, a substituted or unsubstituted divalent aromatic hydrocarbon group having 6 to 18 ring carbon atoms, or a substituted or unsubstituted divalent aromatic heterocyclic group having 5 to 18 ring atoms. Ar1 and Ar2 may be the same or different and represent a substituted or unsubstituted aromatic hydrocarbon group, or a substituted or unsubstituted aromatic heterocyclic group.

[0019] 2) The heterocyclic compound according to 1) above, wherein the heterocyclic compound is represented by the following general formula (1-a):

[0020] [ka] (1-a)

[0021] (In the formula, L1, L2, Ar1, and Ar2 are as defined in the general formula (1) above.)

[0022] 3) The heterocyclic compound according to 1) above, wherein the heterocyclic compound is represented by the following general formula (1-b):

[0023] [ka] (1-b)

[0024] (In the formula, L1, L2, Ar1, and Ar2 are as defined in the general formula (1) above.)

[0025] 4) The heterocyclic compound according to any one of 1) to 3) above, wherein in the general formula (1), general formula (1-a), or general formula (1-b), at least one of L1 and L2 is a single bond, a divalent group obtained by removing two hydrogen atoms from substituted or unsubstituted benzene, a divalent group obtained by removing two hydrogen atoms from substituted or unsubstituted biphenyl, or a divalent group obtained by removing two hydrogen atoms from substituted or unsubstituted naphthalene.

[0026] 5) A heterocyclic compound according to any one of 1) to 3) above, wherein in the general formula (1), general formula (1-a), or general formula (1-b), at least one of L1 and L2 is represented by the following general formula (2):

[0027] [ka] (2)

[0028] (In the formula, R1 to R4 represent a hydrogen atom, a cyano group, a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted alkyloxy group having 1 to 6 carbon atoms, or a substituted or unsubstituted aromatic hydrocarbon group having 6 to 12 ring carbon atoms.)

[0029] 6) An organic thin film comprising the heterocyclic compound according to any one of 1) to 5) above, characterized in that the refractive index in the wavelength range of 450 nm to 750 nm is 1.70 or more.

[0030] 7) An organic EL device having at least an anode electrode, a hole transport layer, an emitting layer, an electron transport layer, a cathode electrode, and a capping layer in this order, wherein the capping layer is the organic thin film described in 6) above.

[0031] 8) An electronic device or electronic element having a pair of electrodes and at least one organic layer sandwiched between them, characterized in that the organic layer contains the heterocyclic compound described in any one of 1) to 5) above as a constituent material.

[0032] In the present invention, examples of the "substituent" in the term "substituted or unsubstituted" include specifically a cyano group, a nitro group, a halogen atom; an alkyl group having 1 to 6 carbon atoms such as a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, an n-pentyl group, an isopentyl group, a neopentyl group, and an n-hexyl group; a methyloxy group, an ethyloxy group, an n-propyloxy group, an isopropyloxy group, an n-butyloxy group, an isobutyloxy group, a tert-butyloxy group, an n-pentyloxy group, an isopentyloxy group, and an n-hexyl group; alkyloxy groups having 1 to 6 carbon atoms, such as an oxy group, a neopentyloxy group, or an n-hexyloxy group; aromatic hydrocarbon groups, such as a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, an anthracenyl group, a phenanthrenyl group, a fluorenyl group, a spirobifluorenyl group, an indenyl group, a pyrenyl group, a perylenyl group, a fluoranthenyl group, or a triphenylenyl group; pyridyl group, pyrimidinyl group, triazinyl group, furyl group, pyrrolyl group, thienyl group, quinolyl group, isoquinolyl group, benzofuranyl group, benzothienyl group, indolyl group, or carbazolyl group ,tree a benzoxalinyl group, a benzimidazolyl group, a pyrazolyl group, a dibenzofuranyl group, a dibenzothienyl group, a naphthyridinyl group, a phenanthrolinyl group, an acridinyl group, a carbolinyl group, a benzoxazolyl group, a benzothiazolyl group, a phenoxazinyl group, etc. aromatic These substituents may be further substituted with the above-mentioned "substituents." In the present invention, of the "substituents" exemplified above, a cyano group, a nitro group, a halogen atom, an alkyl group having 1 to 3 carbon atoms, an alkyloxy group having 1 to 3 carbon atoms, a phenyl group, a naphthyl group, and a quinolyl group are preferably used.

[0033] Specific examples of the "aromatic hydrocarbon" in the "substituted or unsubstituted divalent aromatic hydrocarbon group having 6 to 18 ring carbon atoms" represented by L1 and L2 in general formula (1) include benzene, biphenyl, terphenyl, naphthalene, anthracene, phenanthrene, and fluorene. And, "a substituted or unsubstituted divalent aromatic hydrocarbon group having 6 to 18 ring carbon atoms" represented by L1 and L2 in general formula (1) "Divalent aromatic hydrocarbon radical" represents a divalent group obtained by removing two hydrogen atoms from the above "aromatic hydrocarbon." Here, the above-mentioned "divalent group of an aromatic hydrocarbon" is preferably a divalent group (phenylene group) obtained by removing two hydrogen atoms from benzene, a divalent group (phenylene group) obtained by removing two hydrogen atoms from biphenyl, or a divalent group (naphthalene group) obtained by removing two hydrogen atoms from naphthalene, and more preferably a divalent group (phenylene group) obtained by removing two hydrogen atoms from benzene or a divalent group (naphthalene group) obtained by removing two hydrogen atoms from naphthalene. Furthermore, the divalent group (phenylene group) obtained by removing two hydrogen atoms from benzene is preferably a divalent group (1,4-phenylene group) obtained by removing two hydrogen atoms from the 1,4-positions of benzene, or a divalent group (1,3-phenylene group) obtained by removing two hydrogen atoms from the 1,3-positions of benzene. Furthermore, the divalent group obtained by removing two hydrogen atoms from biphenyl is preferably a divalent group obtained by removing two hydrogen atoms from the 4,4'-positions of biphenyl. Furthermore, the divalent group obtained by removing two hydrogen atoms from naphthalene is preferably a divalent group obtained by removing two hydrogen atoms from the 1,4-positions of naphthalene.

[0034] Examples of the "aromatic heterocycle" in the "substituted or unsubstituted divalent aromatic heterocycle having 5 to 18 ring atoms" represented by L1 and L2 in general formula (1) include pyridine, pyrimidine, furan, pyrrole, thiophene, quinoline, benzofuran, benzothiophene, dibenzofuran, dibenzothiophene, and phenanthroline. And, "a substituted or unsubstituted divalent aromatic heterocyclic group having 5 to 18 ring-constituting atoms" represented by L1 and L2 in general formula (1) "Divalent aromatic heterocyclic group" represents a divalent group obtained by removing two hydrogen atoms from the above-mentioned "aromatic heterocycle".

[0035] In the "substituted or unsubstituted aromatic hydrocarbon group" represented by Ar1 and Ar2 in general formula (1), Ru " Specific examples of the "aromatic hydrocarbon group" include a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, an anthracenyl group, a phenanthrenyl group, a fluorenyl group, a spirobifluorenyl group, an indenyl group, a pyrenyl group, a perylenyl group, a fluoranthenyl group, and a triphenylenyl group.

[0036] In the "substituted or unsubstituted aromatic heterocyclic group" represented by Ar1 and Ar2 in general formula (1), Ru " Specific examples of the "aromatic heterocyclic group" include a pyridyl group, a pyrimidinyl group, a triazinyl group, a furyl group, a pyrrolyl group, a thienyl group, a quinolyl group, an isoquinolyl group, a benzofuranyl group, a benzothienyl group, an indolyl group, and a carbazolyl group. ,tree Examples of the alkyl group include a pyrazolyl group, a dibenzofuranyl group, a dibenzothienyl group, a naphthyridinyl group, a phenanthrolinyl group, an acridinyl group, a carbolinyl group, a benzoxazolyl group, a benzothiazolyl group, and a phenoxazinyl group.

[0037] "Substituted or unsubstituted alkyl group having 1 to 6 carbon atoms" represented by R1 to R4 in general formula (2) "Alkyl group having 1 to 6 carbon atoms" Specific examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, an n-pentyl group, an isopentyl group, a neopentyl group, and an n-hexyl group.

[0038] "Substituted or unsubstituted alkyloxy group having 1 to 6 carbon atoms" represented by R1 to R4 in general formula (2) "Alkyloxy group having 1 to 6 carbon atoms"Specific examples of such an oxy group include a methyloxy group, an ethyloxy group, an n-propyloxy group, an isopropyloxy group, an n-butyloxy group, an isobutyloxy group, a tert-butyloxy group, an n-pentyloxy group, an isopentyloxy group, a neopentyloxy group, and an n-hexyloxy group.

[0039] "Substituted or unsubstituted aromatic hydrocarbon group having 6 to 12 ring carbon atoms" represented by R1 to R4 in general formula (2) "Aromatic hydrocarbon group having 6 to 12 ring carbon atoms" Specific examples of the alkyl group include a phenyl group, a biphenyl group, and a naphthyl group.

[0040] The heterocyclic compound of the present invention represented by the general formula (1) preferably has a refractive index of 1.70 or more, more preferably 1.80 or more, and even more preferably 1.85 or more in a wavelength range of 450 nm to 750 nm. The heterocyclic compound represented by the general formula (1) of the present invention is preferably a heterocyclic compound represented by (1-a) or (1-b). In addition, in general formula (1), general formula (1-a), or general formula (1-b), at least one of L1 and L2 is preferably a divalent group represented by general formula (2). In general formula (2), R1 to R4 are preferably hydrogen atoms, and more preferably all of R1 to R4 are hydrogen atoms.

[0041] In the organic EL device of the present invention, the thickness of the capping layer is preferably in the range of 30 nm to 120 nm, and more preferably in the range of 40 nm to 80 nm.

[0042] In the organic EL device of the present invention, the capping layer may be formed by laminating or mixing two or more different constituent materials.

[0043] Furthermore, in the organic EL element of the present invention, the refractive index of the capping layer is preferably 1.70 or more, more preferably 1.80 or more, and even more preferably 1.85 or more, within the wavelength range of 450 nm to 750 nm of light transmitted through the capping layer. [Effects of the Invention]

[0044] The heterocyclic compound of the present invention can be used in a capping layer having a higher refractive index than a transparent or semitransparent electrode of an organic EL element, which is provided on the outer side of the transparent or semitransparent electrode, to obtain an organic EL element capable of significantly improving light extraction efficiency.

[0045] In addition, the heterocyclic compound of the present invention can be used not only in organic EL devices but also in the field of electronic devices such as electrophotographic photoreceptors, image sensors, photoelectric conversion elements, and solar cells. [Brief explanation of the drawings]

[0046] [Figure 1] FIG. 1 shows structural formulas of compounds (1-1) to (1-16) as heterocyclic compounds represented by general formula (1) of the present invention. [Figure 2] FIG. 1 shows structural formulas of compounds (1-17) to (1-34) as heterocyclic compounds represented by general formula (1) of the present invention. [Figure 3] FIG. 1 shows structural formulas of compounds (1-35) to (1-50) as heterocyclic compounds represented by general formula (1) of the present invention. [Figure 4] FIG. 1 shows structural formulas of compounds (1-51) to (1-68) as heterocyclic compounds represented by general formula (1) of the present invention. [Figure 5] FIG. 1 shows structural formulas of compounds (1-69) to (1-82), which are heterocyclic compounds represented by general formula (1) of the present invention. [Figure 6] FIG. 1 shows structural formulas of compounds (1-83) to (1-96), which are heterocyclic compounds represented by general formula (1) of the present invention. [Figure 7]FIG. 1 shows structural formulas of compounds (1-97) to (1-110), which are heterocyclic compounds represented by general formula (1) of the present invention. [Figure 8] FIG. 1 shows structural formulas of compounds (1-111) to (1-124) as heterocyclic compounds represented by general formula (1) of the present invention. [Figure 9] FIG. 1 shows structural formulas of compounds (1-125) to (1-138), which are heterocyclic compounds represented by general formula (1) of the present invention. [Figure 10] FIG. 1 shows structural formulas of compounds (1-139) to (1-152), which are heterocyclic compounds represented by general formula (1) of the present invention. [Figure 11] FIG. 1 shows structural formulas of compounds (1-153) to (1-155), which are heterocyclic compounds represented by general formula (1) of the present invention. [Figure 12] FIG. 1 shows the configurations of the organic EL devices of Examples 21 to 38 and Comparative Examples 1 and 2. DETAILED DESCRIPTION OF THE INVENTION

[0047] The heterocyclic compounds of the present invention represented by the general formula (1) are novel compounds, but these compounds themselves can be synthesized according to known methods.

[0048] Specific examples of the heterocyclic compound represented by general formula (1) of the present invention are shown in FIGS. 1 to 11, but the present invention is not limited to these compounds.

[0049] The method for producing the heterocyclic compound represented by general formula (1) of the present invention is not particularly limited, but the compound can be purified by known methods used for purifying organic compounds, such as purification by column chromatography, adsorption purification using silica gel, activated carbon, activated clay, etc., recrystallization or crystallization using a solvent, and finally, purification by sublimation purification, etc. The compound can be identified by NMR analysis, etc. It is preferable to measure the melting point, glass transition temperature (Tg), and refractive index as physical property values.

[0050] The melting point and glass transition point (Tg) can be measured, for example, using a powder with a high-sensitivity differential scanning calorimeter (manufactured by Bruker AXS, DSC3100SA).

[0051] The refractive index can be measured by forming an 80 nm thin film on a silicon substrate and using a spectrophotometer (F10-RT-UV, manufactured by Filmetrics).

[0052] The organic EL device of the present invention may have a top-emission structure, in which an anode, a hole transport layer, an emitting layer, an electron transport layer, a cathode, and a capping layer are sequentially arranged on a glass substrate. It may also have a hole injection layer between the anode and the hole transport layer, an electron blocking layer between the hole transport layer and the emitting layer, a hole blocking layer between the emitting layer and the electron transport layer, or an electron injection layer between the electron transport layer and the cathode. In these multilayer structures, some organic layers may be omitted or may serve as multiple layers. For example, a layer may serve as both a hole injection layer and a hole transport layer, a layer may serve as both a hole transport layer and an electron blocking layer, a layer may serve as both a hole blocking layer and an electron transport layer, or a layer may serve as both an electron transport layer and an electron injection layer. It may also have a structure in which two or more organic layers having the same function are stacked, such as a layer with two hole transport layers, a layer with two emitting layers, a layer with two electron transport layers, or a layer with two capping layers.

[0053] The total thickness of each layer of the organic EL element is preferably about 200 nm to 750 nm, more preferably about 350 nm to 600 nm. The thickness of the capping layer is preferably, for example, 30 nm to 120 nm, more preferably 40 nm to 80 nm. In this case, good light extraction efficiency can be obtained. The thickness of the capping layer can be appropriately changed depending on the type of light-emitting material used in the light-emitting element, the thickness of each layer of the organic EL element other than the capping layer, and the like.

[0054] For the anode of the organic EL device of the present invention, an electrode material with a large work function such as ITO or gold is used.

[0055] For the hole injection layer of the organic EL device of the present invention, preferred materials include arylamine compounds having two or more triphenylamine structures in a molecule linked by a single bond or a divalent group containing no heteroatoms, such as benzidine derivatives, starburst triphenylamine derivatives, and various triphenylamine tetramers. Porphyrin compounds, such as copper phthalocyanine, acceptor heterocyclic compounds such as hexacyanoazatriphenylene, and polymeric coating materials can also be used. These materials can be used alone or in combination with other materials to form a single layer, or in a laminate structure of layers formed by mixing layers formed by themselves, layers formed by mixing layers formed by themselves, or layers formed by mixing layers formed by mixing layers formed by themselves. These materials can be used to form thin films by known methods, such as vapor deposition, spin coating, or inkjet printing.

[0056] For the hole-transport layer of the organic EL device of the present invention, benzidine derivatives such as N,N'-diphenyl-N,N'-di(m-tolyl)benzidine (TPD), N,N'-diphenyl-N,N'-di(α-naphthyl)benzidine (NPD), and N,N,N',N'-tetrabiphenylylbenzidine, 1,1-bis[4-(di-4-tolylamino)phenyl]cyclohexane (TAPC), and particularly arylamine compounds having two triphenylamine structures linked by a single bond or a divalent group not containing a heteroatom, such as N,N,N',N'-tetrabiphenylylbenzidine, are preferred. Also preferred are arylamine compounds having only one triphenylamine structure per molecule, and arylamine compounds having three or more triphenylamine structures linked by a single bond or a divalent group not containing a heteroatom, such as various triphenylamine trimers and tetramers. These materials can be formed as films by themselves, or as single layers formed by mixing with other materials. They can also be used as laminated structures of layers formed by themselves, layers formed by mixing, or layers formed by mixing with other materials. Furthermore, coating-type polymer materials such as poly(3,4-ethylenedioxythiophene) (PEDOT) / poly(styrene sulfonate) (PSS) can be used as hole injection / transport layers. These materials can be formed into thin films by known methods such as vapor deposition, spin coating, and inkjet printing.

[0057] Furthermore, in the hole injection layer or hole transport layer, it is preferable to use a material that is p-doped with trisbromophenylaminehexachloroantimony, a radialene derivative, etc., in addition to the materials normally used in the layer. Also, a polymer compound having a benzidine derivative structure such as TPD in its partial structure can be used.

[0058] The electron-blocking layer of the organic EL device of the present invention can be formed using compounds having electron-blocking properties, such as carbazole derivatives such as 4,4',4"-tri(N-carbazolyl)triphenylamine (TCTA), 9,9-bis[4-(carbazol-9-yl)phenyl]fluorene, 1,3-bis(carbazol-9-yl)benzene (mCP), and 2,2-bis(4-carbazol-9-ylphenyl)adamantane (Ad-Cz), and compounds having a triphenylsilyl group and a triarylamine structure, such as 9-[4-(carbazol-9-yl)phenyl]-9-[4-(triphenylsilyl)phenyl]-9H-fluorene. These compounds may be formed as a film alone or as a single layer formed by mixing with other materials. Alternatively, they may be formed as a laminate structure of layers formed alone, layers formed as a mixture, or layers formed as a mixture with layers formed alone. These materials can be used to form thin films by known methods such as vapor deposition, spin coating, and ink jet printing.

[0059] The light-emitting layer of the organic EL device of the present invention can be formed using metal complexes of quinolinol derivatives such as Alq3, as well as various metal complexes, anthracene derivatives, bisstyrylbenzene derivatives, pyrene derivatives, oxazole derivatives, polyparaphenylenevinylene derivatives, and the like. The light-emitting layer can also be formed using a host material and a dopant material. Anthracene derivatives are preferred as the host material. In addition to the light-emitting materials, heterocyclic compounds having an indole ring as a fused ring substructure, heterocyclic compounds having a carbazole ring as a fused ring substructure, carbazole derivatives, thiazole derivatives, benzimidazole derivatives, polydialkylfluorene derivatives, and the like can also be used. Furthermore, dopant materials can be used, such as quinacridone, coumarin, rubrene, perylene, and their derivatives, benzopyran derivatives, rhodamine derivatives, and aminostyryl derivatives. These may be formed alone, or may be mixed with other materials to form a single layer, or may be stacked with other layers formed alone, other layers formed as a mixture, or a layer formed alone and a layer formed as a mixture.

[0060] Phosphorescent emitters can also be used as light-emitting materials. Examples of phosphorescent emitters include metal complexes of iridium and platinum. Examples include green phosphorescent emitters such as Ir(ppy)3, blue phosphorescent emitters such as FIrpic and FIr6, and red phosphorescent emitters such as Btp2Ir(acac). Hole-injecting and transporting host materials include carbazole derivatives such as 4,4'-di(N-carbazolyl)biphenyl (CBP), TCTA, and mCP. Electron-transporting host materials include p-bis(triphenylsilyl)benzene (UGH2) and 2,2',2''-(1,3,5-phenylene)-tris(1-phenyl-1H-benzimidazole) (TPBI), enabling the fabrication of high-performance organic EL devices.

[0061] In order to avoid concentration quenching, the phosphorescent light-emitting material is preferably doped into the host material by co-evaporation in an amount ranging from 1 to 30 weight percent based on the entire light-emitting layer.

[0062] Furthermore, a material that emits delayed fluorescence can also be used as the light-emitting material. These materials can be formed into thin films by known methods such as vapor deposition, spin coating, and ink-jet printing.

[0063] The hole-blocking layer of the organic EL device of the present invention can be formed using compounds with hole-blocking properties, such as phenanthroline derivatives such as bathocuproine (BCP), metal complexes of quinolinol derivatives such as aluminum(III) bis(2-methyl-8-quinolinato)-4-phenylphenolate (BAlq), various rare earth complexes, triazole derivatives, triazine derivatives, pyrimidine derivatives, oxadiazole derivatives, and benzoazole derivatives. These materials may also serve as materials for the electron-transporting layer. These materials may be formed alone or mixed with other materials to form a single layer, or may be stacked together with other layers, or with other layers, or with other layers. These materials can be formed into thin films by known methods such as vapor deposition, spin coating, and inkjet printing.

[0064] The electron transport layer of the organic EL device of the present invention can be formed using metal complexes of quinolinol derivatives such as Alq3 and BAlq, as well as various metal complexes, triazole derivatives, triazine derivatives, pyrimidine derivatives, oxadiazole derivatives, pyridine derivatives, benzimidazole derivatives, benzoazole derivatives, thiadiazole derivatives, anthracene derivatives, carbodiimide derivatives, quinoxaline derivatives, pyridoindole derivatives, phenanthroline derivatives, and silole derivatives. These materials can be formed into thin films by vapor deposition or known methods such as spin coating and inkjet printing. These materials can be used alone or mixed with other materials to form a single layer. They can also be used as a laminate structure consisting of layers formed alone, layers formed in a mixture, or layers formed in a mixture with other layers. These materials can be used to form thin films by known methods such as vapor deposition, spin coating, and inkjet printing.

[0065] The electron injection layer of the organic EL device of the present invention can be made of alkali metal salts such as lithium fluoride and cesium fluoride, alkaline earth metal salts such as magnesium fluoride, metal complexes of quinolinol derivatives such as lithium quinolinol, metal oxides such as aluminum oxide, or metals such as ytterbium (Yb), samarium (Sm), calcium (Ca), strontium (Sr), and cesium (Cs). However, in the preferred selection of the electron transport layer and the cathode, this can be omitted.

[0066] Furthermore, in the electron injection layer or electron transport layer, a material that is n-doped with a metal such as cesium can be used in addition to the materials that are normally used in the layer.

[0067] For the cathode of the organic EL element of the present invention, an electrode material having a low work function such as aluminum, an alloy having an even lower work function such as a magnesium-silver alloy, a magnesium-calcium alloy, a magnesium-indium alloy, or an aluminum-magnesium alloy, ITO, IZO, or the like is used as the electrode material.

[0068] The capping layer of the organic EL device of the present invention preferably uses a heterocyclic compound represented by the general formula (1), (1-a), or (1-b). These materials can be formed into thin films by known methods such as vapor deposition, spin coating, and ink-jet printing.

[0069] Although the organic EL element having a top emission structure has been described above, the present invention is not limited to this and can be similarly applied to an organic EL element having a bottom emission structure or an organic EL element having a dual emission structure that emits light from both the top and bottom. In these cases, the electrode in the direction in which light is extracted from the light-emitting element to the outside must be transparent or semi-transparent. [Example]

[0070] Hereinafter, the present invention will be described in detail with reference to examples, but the present invention is not limited to the following examples as long as it does not depart from the gist of the invention.

[0071] [Example 1] <Synthesis of 2,5-bis{4-(phenanthrene-9-yl)phenyl}pyrimidine; Compound (1-7)> A nitrogen-purged reaction vessel was charged with 5.0 g of 2,5-dichloropyrimidine, 50 mL of 1,4-dioxane, 28.1 g of 4,4,5,5-tetramethyl-2-{4-(phenanthrene-9-yl)phenyl}-1,3,2-dioxaborolane, and then a solution of 21.4 g of tripotassium phosphate in 15 mL of purified water. Nitrogen was then bubbled through for 30 minutes. Then, 1.5 g of trisdibenzylideneacetonedipalladium and 1.9 g of tricyclohexylphosphine were added and the mixture was stirred under reflux for 12 hours. After cooling to room temperature, 50 mL of methanol was added, and the precipitated solid was collected by filtration. 1.0 L of chlorobenzene was added to the solid, and the mixture was heated to 100 °C to dissolve the solid. Then, 10 g of silica gel and 10 g of activated clay were added, and the mixture was stirred for 1 hour. Insoluble matter was removed by hot filtration, and the filtrate was concentrated. The residue was recrystallized from chlorobenzene to obtain 12.6 g (yield: 64%) of a white powder of 2,5-bis{4-(phenanthrene-9-yl)phenyl}pyrimidine; compound (1-7).

[0072] [ka] (1-7)

[0073] The structure of the obtained white powder was identified using NMR. 1 The following 28 hydrogen signals were detected by H-NMR (THF-d8). δ(ppm)=9.33(2H), 8.80-8.94(6H), 7.99-8.06(6H), 7.60-7.85(14H).

[0074] [Example 2] <Synthesis of 2,5-bis{4-(phenanthrene-9-yl)phenyl}pyridine; Compound (1-41)> In Example 1, 2,5-dichloropyrimidine was replaced with 2,5-dibromopyridine, and the same procedure was carried out to obtain 11.5 g (yield: 78%) of a white powder of 2,5-bis{4-(phenanthren-9-yl)phenyl}pyridine; compound (1-41).

[0075] [ka] (1-41)

[0076] The structure of the obtained white powder was identified using NMR. 1 The following 29 hydrogen signals were detected by H-NMR (THF-d8). δ(ppm)=9.14(1H), 8.81-8.89(4H), 8.39-8.41(2H), 8.22-8.23(1H), 8.12-8.14(1H), 7.95-8.01(6H), 7.80(2H), 7.56-7.79(12H).

[0077] [Example 3] Synthesis of 5-{4-(dibenzofuran-3-yl)phenyl}-2-{4-(phenanthrene-9-yl)phenyl}pyrimidine; Compound (1-71) A nitrogen-purged reaction vessel was charged with 9.4 g of 2,5-dichloropyrimidine, 160 mL of toluene, 60 mL of ethanol, 20.0 g of 4,4,5,5-tetramethyl-2-{4-(phenanthrene-9-yl)phenyl}-1,3,2-dioxaborolane, and then a solution of 10.9 g of potassium carbonate in 40 mL of purified water. Nitrogen was bubbled through the vessel for 30 minutes. Then, 0.6 g of tetrakis(triphenylphosphine)palladium(0) was added and the mixture was stirred under reflux for 15 hours. The mixture was cooled to room temperature and separated. The organic layer was washed sequentially with water and saturated brine, and then dried over anhydrous magnesium sulfate. The desiccant was removed by filtration, and the filtrate was concentrated. 200 mL of toluene was added to the residue, heated to 80°C, and then 10 g of silica gel and 10 g of activated clay were added and stirred for 1 hour. Insoluble matter was removed by filtration, and the filtrate was concentrated. Acetone was added to the residue, and the mixture was dispersed and washed to obtain 16.5 g (yield: 86%) of white powder of 5-chloro-2-{4-(phenanthrene-9-yl)phenyl}pyrimidine.

[0078] 8.0 g of the resulting 5-chloro-2-{4-(phenanthrene-9-yl)phenyl}pyrimidine was added to a nitrogen-purged reaction vessel. 100 mL of 1,4-dioxane, 28.1 g of 3-{4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl}dibenzofuran, and a solution of 21.4 g of tripotassium phosphate in 15 mL of purified water were added sequentially, followed by bubbling with nitrogen for 30 minutes. 0.2 g of trisdibenzylideneacetonedipalladium and 0.1 g of tricyclohexylphosphine were then added, and the mixture was stirred under reflux for 13 hours. After cooling to room temperature, the precipitated solid was collected by filtration. Methanol and water were added to the solid, and the mixture was refluxed for 1 hour for dispersion and washing. 750 mL of chlorobenzene was added to the collected solid, and the mixture was heated to 100 °C to dissolve the solid. 8 g of silica gel and 8 g of activated clay were then added, and the mixture was stirred for 1 hour. The insoluble matter was removed by hot filtration, and the filtrate was concentrated. The residue was recrystallized from chlorobenzene to give 10.5 g (72% yield) of white powder of 5-{4-(dibenzofuran-3-yl)phenyl}-2-{4-(phenanthren-9-yl)phenyl}pyrimidine (1-71).

[0079] [ka] (1-71)

[0080] The structure of the obtained white powder was identified using NMR. 1 The following 26 hydrogen signals were detected by H-NMR (THF-d8). δ(ppm)=9.28(2H), 8.76-8.92(4H), 7.96-8.18(9H), 7.36-7.86(11H).

[0081] [Example 4] Synthesis of 5-{4-(phenanthrene-2-yl)phenyl}-2-{4-(phenanthrene-9-yl)phenyl}pyrimidine; Compound (1-74) In Example 3, 3-{4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl}dibenzofuran was replaced with 4,4,5,5-tetramethyl-2-{4-(phenanthrene-2-yl)phenyl}-1,3,2-dioxaborolane, and the same operation was performed to obtain 8.6 g (yield: 58%) of a white powder of 5-{4-(phenanthrene-2-yl)phenyl}-2-{4-(phenanthrene-9-yl)phenyl}pyrimidine; compound (1-74).

[0082] [ka] (1-74)

[0083] The structure of the obtained white powder was identified using NMR. 1 The following 28 hydrogen signals were detected by H-NMR (THF-d8). δ(ppm)=9.31(2H), 8.78-8.93(6H), 8.35-8.36(1H), 7.91-8.13(9H), 7.85-7.87(2H), 7.60-7.76(8H).

[0084] [Example 5] Synthesis of 2-{4-(phenanthrene-9-yl)phenyl}-5-{4-(1,10-phenanthrolin-2-yl)phenyl}pyrimidine; Compound (1-137) In Example 3, 3-{4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl}dibenzofuran was replaced with 4,4,5,5-tetramethyl-2-{4-(1,10-phenanthrolin-2-yl)phenyl}-1,3,2-dioxaborolane, and the same operation was performed to obtain 7.5 g (yield: 46.8%) of a white powder of 2-{4-(phenanthren-9-yl)phenyl}-5-{4-(1,10-phenanthrolin-2-yl)phenyl}pyrimidine; compound (1-137).

[0085] [ka] (1-137)

[0086] The structure of the obtained white powder was identified using NMR. 1 The following 26 hydrogen signals were detected by H-NMR (CDCl3). δ(ppm)=9.47(1H), 8.82(1H), 8.76(1H), 8.47(1H), 8.39(2H), 8.31(1H), 8.21(1H), 8.17(1H), 8.03(1 H), 8.00-7.89(6H), 7.86(1H), 7.78(1H), 7.74(2H), 7.70(2H), 7.66(1H), 7.61(1H), 7.56-7.50(2H).

[0087] [Example 6] <2,5-bis{4-(dibenzothiophen-4-yl)phenyl} pyrimidine Synthesis of Compound (1-20) The same procedure as in Example 1 was repeated except that 4,4,5,5-tetramethyl-2-{4-(phenanthrene-9-yl)phenyl}-1,3,2-dioxaborolane was used instead of 4,4,5,5-tetramethyl-2-{4-(dibenzothiophen-4-yl)phenyl}-1,3,2-dioxaborolane to obtain 2,5-bis{4-(dibenzothiophen-4-yl)phenyl} pyrimidine 4.0 g (yield: 40.0%) of compound (1-20) was obtained as a white powder.

[0088] [ka] (1-20)

[0089] The structure of the obtained white powder was identified using NMR. 1 The following 24 hydrogen signals were detected by H-NMR (CDCl3). δ(ppm)=9.18(2H), 8.69(2H), 8.23(4H), 7.95(4H), 7.86(4H), 7.64-7.54(4H), 7.54-7.45(4H).

[0090] [Example 7] <2,5-bis{4-(1,10-phenanthrolin-2-yl)phenyl} pyrimidine Synthesis of Compound (1-154) The same procedure as in Example 1 was repeated except that 4,4,5,5-tetramethyl-2-{4-(phenanthrene-9-yl)phenyl}-1,3,2-dioxaborolane was used instead of 4,4,5,5-tetramethyl-2-{4-(1,10-phenanthrolin-2-yl)phenyl}-1,3,2-dioxaborolane to obtain 2,5-bis{4-(1,10-phenanthrolin-2-yl)phenyl} pyrimidine 10.6 g (yield: 59.5%) of compound (1-154) was obtained as a white powder.

[0091] [ka] (1-154)

[0092] The structure of the obtained white powder was identified using NMR. 1 The following 24 hydrogen signals were detected by H-NMR (CDCl3). δ(ppm)=9.28(1H), 8.80(1H), 8.75(1H), 8.50(2H), 8.33(1H), 8.27(1H), 8.18(1H), 8.03(1H), 7.95-7.74(8H), 7.72-7.54(7H).

[0093] [Example 8] Synthesis of 5-(dibenzofuran-3-yl)-2-(9,9'-spirobi[9H]fluoren-2-yl)pyrimidine; Compound (1-89) In a nitrogen-purged reaction vessel, 30.0 g of 2,5-dichloropyrimidine, 66.0 g of 2-9,9'-spirobi[9H]fluoreneboronic acid, 2.1 g of tetrakis(triphenylphosphine)palladium(0), and 38.0 g of potassium carbonate were added, and a mixed solvent of toluene / ethanol / water was added. Medium The mixture was refluxed overnight at RT. After cooling, toluene and water were added, and the organic layer was extracted and separated. The organic layer was concentrated to obtain a crude product. The crude product was purified by column chromatography (carrier: silica gel, eluent: dichloromethane / n-heptane) to obtain 39.0 g (yield: 49.6%) of 5-chloro-2-(9,9'-spirobi[9H]fluoren-2-yl)pyrimidine as a white powder.

[0094] 9.5 g of the resulting 5-chloro-2-(9,9'-spirobi[9H]fluoren-2-yl)pyrimidine was added to a nitrogen-purged reaction vessel. 5.2 g of (dibenzofuran-3-yl)boronic acid, 6.1 g of tripotassium phosphate, 0.2 g of tris(dibenzylideneacetone)dipalladium(0), 0.1 g of tricyclohexylphosphine, 100 mL of 1,4-dioxane, and 30 mL of purified water were added and stirred overnight under reflux. After cooling, methanol was added and the precipitated solid was collected by filtration to obtain the crude product. The resulting crude product was purified by crystallization using a chlorobenzene / acetone mixed solvent to obtain 8.4 g (68.0% yield) of a white powder of 5-(dibenzofuran-3-yl)-2-(9,9'-spirobi[9H]fluoren-2-yl)pyrimidine (compound (1-89)).

[0095] [ka] (1-89)

[0096] The structure of the obtained white powder was identified using NMR. 1 The following 24 hydrogen signals were detected by H-NMR (CDCl3). δ(ppm)=8.97(2H), 8.61(1H), 8.04(1H), 8.00(1H), 7.98(1H), 7.92(1H), 7.90(1H), 7.88(2H), 7 .74(1H), 7.59(1H), 7.53(1H), 7.49(1H), 7.39(4H), 7.14(1H), 7.11(2H), 6.79(2H), 6.74(1H).

[0097] [Example 9] Synthesis of 5-{4-(naphthalen-1-yl)phenyl}-2-(9,9'-spirobi[9H]fluoren-2-yl)pyrimidine; Compound (1-142) In Example 8, (dibenzofuran-3-yl)boronic acid was replaced with 4-(naphthalen-1-yl)phenylboronic acid, and the same operation was performed to obtain 9.8 g (yield: 71.0%) of a white powder of 5-{4-(naphthalen-1-yl)phenyl}-2-(9,9'-spirobi[9H]fluoren-2-yl)pyrimidine; compound (1-142).

[0098] [ka] (1-142)

[0099] The structure of the obtained white powder was identified using NMR. 1 The following 28 hydrogen signals were detected by H-NMR (CDCl3). δ(ppm)=8.98(2H), 8.62(1H), 8.01(1H), 7.90(7H), 7.65(4H), 7.58-7.34(7H), 7.14(1H), 7.11(2H), 6.79(2H), 6.74(1H).

[0100] [Example 10] Synthesis of 5-{4-(naphthalen-2-yl)phenyl}-2-(9,9'-spirobi[9H]fluoren-2-yl)pyrimidine; Compound (1-143) In Example 8, (dibenzofuran-3-yl)boronic acid was replaced with 4-(naphthalen-2-yl)phenylboronic acid, and the same procedure was performed to obtain 10.6 g (yield: 76.3%) of a white powder of 5-{4-(naphthalen-2-yl)phenyl}-2-(9,9'-spirobi[9H]fluoren-2-yl)pyrimidine; compound (1-143).

[0101] [ka] (1-143)

[0102] The structure of the obtained white powder was identified using NMR. 1 The following 28 hydrogen signals were detected by H-NMR (CDCl3). δ(ppm)=8.95(2H), 8.60(1H), 8.07(1H), 8.00(1H), 7.96-7.81(9H), 7.76(1H ), 7.67(2H), 7.51(2H), 7.38(3H), 7.14(1H), 7.11(2H), 6.79(2H), 6.74(1H).

[0103] [Example 11] Synthesis of 5-{4-(benzothiophen-2-yl)phenyl}-2-(9,9'-spirobi[9H]fluoren-2-yl)pyrimidine; Compound (1-146) In Example 8, (dibenzofuran-3-yl)boronic acid was replaced with 4,4,5,5-tetramethyl-2-{4-(benzothiophen-2-yl)phenyl}-1,3,2-dioxaborolane, and the same operation was performed to obtain 9.4 g (yield: 70.0%) of a white powder of 5-{4-(benzothiophen-2-yl)phenyl}-2-(9,9'-spirobi[9H]fluoren-2-yl)pyrimidine; compound (1-146).

[0104] [ka] (1-146)

[0105] The structure of the obtained white powder was identified using NMR. 1 The following 26 hydrogen signals were detected by H-NMR (CDCl3). δ(ppm)=8.93(2H), 8.60(1H), 8.00(1H), 7.92(1H), 7.90-7.81(6H), 7.79( 1H), 7.62(3H), 7.43-7.30(5H), 7.14(1H), 7.11(2H), 6.78(2H), 6.74(1H).

[0106] [Example 12] Synthesis of 5-{4-(benzoxazol-2-yl)phenyl}-2-(9,9'-spirobi[9H]fluoren-2-yl)pyrimidine; Compound (1-147) In Example 8, (dibenzofuran-3-yl)boronic acid was replaced with 4,4,5,5-tetramethyl-2-{4-(benzoxazol-2-yl)phenyl}-1,3,2-dioxaborolane, and the same operation was performed to obtain 12.5 g (yield: 91.2%) of a white powder of 5-{4-(benzoxazol-2-yl)phenyl}-2-(9,9'-spirobi[9H]fluoren-2-yl)pyrimidine; compound (1-147).

[0107] [ka] (1-147)

[0108] The structure of the obtained white powder was identified using NMR. 1 The following 25 hydrogen signals were detected by H-NMR (CDCl3). δ(ppm)=8.96(2H), 8.61(1H), 8.37(2H), 8.00(1H), 7.92(1H), 7.90(1H), 7.88(2H), 7.8 0(1H), 7.72(2H), 7.61(1H), 7.42-7.35(5H), 7.15(1H), 7.11(2H), 6.78(2H), 6.74(1H).

[0109] [Example 13] <5-{4-(benzothiazol-2-yl)phenyl}-2-(9,9'-spirobi[9H]fluoren-2-yl) )Pi Synthesis of Imidine; Compound (1-148) In Example 8, (dibenzofuran-3-yl)boronic acid was changed to 4,4,5,5-tetramethyl-2-{4-(benzothiazol-2-yl)phenyl}-1,3,2-dioxaborolane, and the same procedure was repeated to obtain 5-{4-(benzothiazol-2-yl)phenyl}-2-(9,9'-spirobi[9H]fluoren-2-yl) )PiImidine: 11.5 g (yield: 81.6%) of compound (1-148) was obtained as a white powder.

[0110] [ka] (1-148)

[0111] The structure of the obtained white powder was identified using NMR. 1 The following 25 hydrogen signals were detected by H-NMR (CDCl3). δ(ppm)=8.95(2H), 8.61(1H), 8.22(2H), 8.10(1H), 8.00(1H), 7.92(2H), 7.89(1H), 7.8 8(2H), 7.69(2H), 7.52(1H), 7.44-7.35(4H), 7.15(1H), 7.11(2H), 6.78(2H), 6.75(1H).

[0112] [Example 14] <5-{4-(9-phenyl-carbazol-3-yl)phenyl}-2-(9,9'-spirobi[9H]fluoren-2-yl) )Pi Synthesis of Imidine; Compound (1-149) In Example 8, (dibenzofuran-3-yl)boronic acid was changed to 4,4,5,5-tetramethyl-2-{4-(9-phenyl-carbazol-3-yl)phenyl}-1,3,2-dioxaborolane, and the same procedure was performed to obtain 5-{4-(9-phenyl-carbazol-3-yl)phenyl}-2-(9,9'-spirobi[9H]fluoren-2-yl )Pi Imidine: 10.1 g (yield: 62.9%) of pale yellow powder of compound (1-149) was obtained.

[0113] [ka] (1-149)

[0114] The structure of the resulting pale yellow powder was identified using NMR. 1 The following 33 hydrogen signals were detected by H-NMR (CDCl3). δ(ppm)=8.97(2H), 8.61(1H), 8.38(1H), 8.20(1H), 8.00(1H), 7.92(1H), 7.90(1H), 7.88(2H), 7.85(2H), 7.7 0-7.56(7H), 7.50(1H), 7.48(1H), 7.43(2H), 7.38(3H), 7.32(1H), 7.14(1H), 7.11(2H), 6.79(2H), 6.74(1H).

[0115] [Example 15] Synthesis of 2-{4-(phenanthrene-9-yl)phenyl}-5-{3,5-bis(naphthalene-2-yl)phenyl}pyrimidine; Compound (1-150) In Example 3, 3-{4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl}dibenzofuran was replaced with 4,4,5,5-tetramethyl-2-{3,5-bis(naphthalen-2-yl)phenyl}-1,3,2-dioxaborolane, and the same operation was performed to obtain 1.8 g (yield: 22.2%) of a white powder of 2-{4-(phenanthren-9-yl)phenyl}-5-{3,5-bis(naphthalen-2-yl)phenyl}pyrimidine; compound (1-150).

[0116] [ka] (1-150)

[0117] The structure of the obtained white powder was identified using NMR. 1 The following 32 hydrogen signals were detected by H-NMR (CDCl3). δ(ppm)=9.25(2H), 8.81(1H), 8.75(1H), 8.69(2H), 8.22(2H), 8.16(1H), 8. 04-7.88(12H), 7.77(1H), 7.74(2H), 7.70(2H), 7.64(1H), 7.60-7.51(5H).

[0118] [Example 16] Synthesis of 2-{4-(phenanthrene-9-yl)phenyl}-5-{3,5-bis(quinolin-3-yl)phenyl}pyrimidine; Compound (1-151) In Example 3, 3-{4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl}dibenzofuran was replaced with 4,4,5,5-tetramethyl-2-{3,5-bis(quinolin-3-yl)phenyl}-1,3,2-dioxaborolane, and the same operation was performed to obtain 4.3 g (yield: 47.6%) of a white powder of 2-{4-(phenanthren-9-yl)phenyl}-5-{3,5-bis(quinolin-3-yl)phenyl}pyrimidine; compound (1-151).

[0119] [ka] (1-151)

[0120] The structure of the obtained white powder was identified using NMR. 1 The following 30 hydrogen signals were detected by H-NMR (CDCl3). δ(ppm)=9.34(2H), 9.24(2H), 8.80(1H), 8.74(1H), 8.69(2H), 8.49(2H), 8.22(2H), 8.13(1H), 8.0 3(2H), 8.00(1H), 7.97(2H), 7.93(1H), 7.80(2H), 7.77(1H), 7.74(2H), 7.72-7.61(5H), 7.57(1H).

[0121] [Example 17] Synthesis of 2-{4-(phenanthrene-9-yl)phenyl}-5-{3,5-bis(naphthalene-2-yl)phenyl}pyridine; Compound (1-152) In a nitrogen-purged reaction vessel, 9.3 g of 2,5-dichloropyridine, 10.0 g of 4,4,5,5-tetramethyl-2-{4-(phenanthrene-9-yl)phenyl}-1,3,2-dioxaborolane, 0.8 g of tetrakis(triphenylphosphine)palladium(0), and 10.9 g of potassium carbonate were added, and a mixed solvent of toluene / ethanol / water was added. Medium The mixture was refluxed and stirred for 5 hours at rt. After cooling, toluene / water was added, and the organic layer was extracted and separated. The organic layer was concentrated to obtain a crude product. The crude product was purified by column chromatography (carrier: silica gel, eluent: toluene / n-heptane) to obtain 9.6 g (yield: 81.5%) of 5-chloro-2-{4-(phenanthren-9-yl)phenyl}pyridine as a white powder.

[0122] 5.0 g of the obtained 5-chloro-2-{4-(phenanthrene-9-yl)phenyl}pyridine was added to a reaction vessel purged with nitrogen, and 6.7 g of 4,4,5,5-tetramethyl-2-{3,5-bis(naphthalen-2-yl)phenyl}-1,3,2-dioxaborolane, 0.4 g of tetrakis(triphenylphosphine)palladium(0), and 2.5 g of potassium carbonate were added, followed by a mixture of toluene, ethanol, and water. Medium The mixture was refluxed and stirred overnight at rt. After cooling, methanol was added and the precipitated solid was collected by filtration to obtain a crude product. The obtained crude product was purified by recrystallization using a toluene solvent to obtain 6.7 g (yield: 83.3%) of a white powder of 2-{4-(phenanthren-9-yl)phenyl}-5-{3,5-bis(naphthalen-2-yl)phenyl}pyridine; compound (1-152).

[0123] [ka] (1-152)

[0124] The structure of the obtained white powder was identified using NMR. 1 The following 33 hydrogen signals were detected by H-NMR (CDCl3). δ(ppm)=9.17(1H), 8.80(1H), 8.75(1H), 8.25(2H), 8.22(2H), 8.18(1H), 8.12(1H), 8. 04-7.95(8H), 7.95-7.88(5H), 7.76(1H), 7.74-7.66(4H), 7.64(1H), 7.60-7.51(5H).

[0125] [Example 18] Synthesis of 2-{4-(phenanthrene-9-yl)phenyl}-5-{3,5-bis(quinolin-3-yl)phenyl}pyridine; Compound (1-153) In Example 17, 4,4,5,5-tetramethyl-2-{3,5-bis(naphthalen-2-yl)phenyl}-1,3,2-dioxaborolane was replaced with 4,4,5,5-tetramethyl-2-{3,5-bis(quinolin-3-yl)phenyl}-1,3,2-dioxaborolane, and the same operation was performed to obtain 5.3 g (yield: 73.0%) of a white powder of 2-{4-(phenanthren-9-yl)phenyl}-5-{3,5-bis(quinolin-3-yl)phenyl}pyridine; compound (1-153).

[0126] [ka] (1-153)

[0127] The structure of the obtained white powder was identified using NMR. 1 The following 31 hydrogen signals were detected by H-NMR (CDCl3). δ(ppm)=9.34(2H), 9.16(2H), 8.80(1H), 8.74(1H), 8.48(2H), 8.28(2H), 8.21(2H), 8.17(1H) , 8.08(1H), 8.05(2H), 8.00(2H), 7.96(2H), 7.92(1H), 7.79(2H), 7.74-7.60(7H), 7.56(1H).

[0128] [Example 19] The glass transition temperature (Tg) and melting point of the heterocyclic compound represented by general formula (1) were measured using a high-sensitivity differential scanning calorimeter (DSC3100SA, manufactured by Bruker AXS). The measurement results are summarized in Table 1.

[0129] [Table 1]

[0130] As described above, the heterocyclic compound represented by the general formula (1) of the present invention has a glass transition temperature (Tg) of 100°C or higher, or does not have an observable glass transition temperature (Tg), which indicates that the compound is stable in a thin film state.

[0131] [Example 20] A heterocyclic compound represented by general formula (1) was used to form an 80 nm thick vapor-deposited film on a silicon substrate, and the refractive index n at wavelengths of 450 nm and 750 nm was measured using a spectrophotometer (F10-RT-UV, manufactured by Filmetrics). For comparison, the comparative compound (2-1) and Alq3, which have the following structural formulas, were also measured. The measurement results are summarized in Table 2.

[0132] [ka] (2-1)

[0133] [Table 2]

[0134] As described above, the refractive index n of the heterocyclic compound represented by the general formula (1) of the present invention is equal to or greater than the refractive index of Alq3 and the comparative compound (2-1) in the wavelength range of 450 nm to 750 nm. This indicates that the use of the heterocyclic compound represented by the general formula (1) of the present invention as a constituent material of the capping layer can be expected to improve the light extraction efficiency of organic EL elements.

[0135] [Example 21] As shown in Figure 12, the organic EL device was fabricated by depositing a hole injection layer 3, a hole transport layer 4, an emitting layer 5, an electron transport layer 6, an electron injection layer 7, a cathode 8, and a capping layer 9 in this order on a glass substrate 1 on which a reflective ITO electrode had previously been formed as a metal anode 2.

[0136] Specifically, a metal anode 2 was formed on a glass substrate 1. The metal anode 2 was formed by depositing a 50 nm thick ITO film, a 100 nm thick silver alloy reflective film, and a 5 nm thick ITO film in that order. This film was then ultrasonically cleaned in isopropyl alcohol for 20 minutes and then dried on a hot plate heated to 250°C for 10 minutes. After 2 minutes of UV ozone treatment, the ITO-attached glass substrate was placed in a vacuum deposition chamber and the pressure was reduced to 0.001 Pa or less. Next, a hole-injection layer 3 was formed covering the metal anode 2 by binary deposition of an electron acceptor (Acceptor-1) of the following structural formula and a compound (3-1) of the following structural formula at a deposition rate ratio of (Acceptor-1):compound (3-1) = 3:97, resulting in a thickness of 10 nm. On top of this hole-injection layer 3, a hole-transport layer 4 was formed by depositing a compound (3-1) of the following structural formula to a thickness of 140 nm. On the hole transport layer 4, a compound (3-2) having the following structural formula and a compound (3-3) having the following structural formula were deposited by binary deposition at a deposition rate ratio of compound (3-2):compound (3-3) = 5:95 to form a 20 nm thick light-emitting layer 5. On the light-emitting layer 5, a compound (3-4) having the following structural formula and a compound (3-5) having the following structural formula were deposited by binary deposition at a deposition rate ratio of compound (3-4):compound (3-5) = 50:50 to form a 30 nm thick electron transport layer 6. On the electron transport layer 6, lithium fluoride was deposited by 1 nm thick to form an electron injection layer 7. On the electron injection layer 7, a magnesium-silver alloy was deposited by 12 nm thick to form a cathode 8. Finally, the compound (1-7) of Example 1 was deposited by 60 nm thick to form a capping layer 9. The characteristics of the fabricated organic EL devices were measured in air at room temperature. The light-emitting characteristics of the fabricated organic EL devices were measured by applying a DC voltage, and the results are summarized in Table 3.

[0137] [ka] (Acceptor-1)

[0138] [ka] (3-1)

[0139] [ka] (3-2)

[0140] [ka] (3-3)

[0141] [ka] (3-4)

[0142] [ka] (3-5)

[0143] [ka] (1-7)

[0144] [Example 22] An organic EL device was fabricated under the same conditions as in Example 21, except that the compound (1-41) of Example 2 was used as the capping layer 9 instead of the compound (1-7) of Example 1. The characteristics of the fabricated organic EL device were measured in air at room temperature. The light-emitting characteristics of the fabricated organic EL devices were measured by applying a DC voltage, and the results are summarized in Table 3.

[0145] [ka] (1-41)

[0146] [Example 23] An organic EL device was fabricated under the same conditions as in Example 21, except that the compound (1-71) of Example 3 was used as the capping layer 9 instead of the compound (1-7) of Example 1. The characteristics of the fabricated organic EL device were measured in air at room temperature. The light-emitting characteristics of the fabricated organic EL devices were measured by applying a DC voltage, and the results are summarized in Table 3.

[0147] [ka] (1-71)

[0148] [Example 24] An organic EL device was fabricated under the same conditions as in Example 21, except that the compound (1-74) of Example 4 was used as the capping layer 9 instead of the compound (1-7) of Example 1. The characteristics of the fabricated organic EL device were measured in air at room temperature. The light-emitting characteristics of the fabricated organic EL devices were measured by applying a DC voltage, and the results are summarized in Table 3.

[0149] [ka] (1-74)

[0150] [Example 25] An organic EL device was fabricated under the same conditions as in Example 21, except that the compound (1-137) of Example 5 was used instead of the compound (1-7) of Example 1 for the capping layer 9. The characteristics of the fabricated organic EL device were measured in air at room temperature. The light-emitting characteristics of the fabricated organic EL devices were measured by applying a DC voltage, and the results are summarized in Table 3.

[0151] [ka] (1-137)

[0152] [Example 26] An organic EL device was fabricated under the same conditions as in Example 21, except that the compound (1-20) of Example 6 was used instead of the compound (1-7) of Example 1 as the capping layer 9. The characteristics of the fabricated organic EL device were measured in air at room temperature. The light-emitting characteristics of the fabricated organic EL devices were measured by applying a DC voltage, and the results are summarized in Table 3.

[0153] [ka] (1-20)

[0154] [Example 27] An organic EL device was fabricated under the same conditions as in Example 21, except that the compound (1-154) of Example 7 was used instead of the compound (1-7) of Example 1 for the capping layer 9. The characteristics of the fabricated organic EL device were measured in the air at room temperature. The light-emitting characteristics of the fabricated organic EL devices were measured by applying a DC voltage, and the results are summarized in Table 3.

[0155] [ka] (1-154)

[0156] [Example 28] An organic EL device was fabricated under the same conditions as in Example 21, except that the compound (1-89) of Example 8 was used instead of the compound (1-7) of Example 1 as the capping layer 9. The characteristics of the fabricated organic EL device were measured in the air at room temperature. The light-emitting characteristics of the fabricated organic EL devices were measured by applying a DC voltage, and the results are summarized in Table 3.

[0157] [ka] (1-89)

[0158] [Example 29] An organic EL device was fabricated under the same conditions as in Example 21, except that the compound (1-142) of Example 9 was used instead of the compound (1-7) of Example 1 for the capping layer 9. The characteristics of the fabricated organic EL device were measured in air at room temperature. The light-emitting characteristics of the fabricated organic EL devices were measured by applying a DC voltage, and the results are summarized in Table 3.

[0159] [ka] (1-142)

[0160] [Example 30] An organic EL device was fabricated under the same conditions as in Example 21, except that the compound (1-143) of Example 10 was used as the capping layer 9 instead of the compound (1-7) of Example 1. The characteristics of the fabricated organic EL device were measured in air at room temperature. The light-emitting characteristics of the fabricated organic EL devices were measured by applying a DC voltage, and the results are summarized in Table 3.

[0161] [ka] (1-143)

[0162] [Example 31] An organic EL device was fabricated under the same conditions as in Example 21, except that the compound (1-146) of Example 11 was used as the capping layer 9 instead of the compound (1-7) of Example 1. The characteristics of the fabricated organic EL device were measured in air at room temperature. The light-emitting characteristics of the fabricated organic EL devices were measured by applying a DC voltage, and the results are summarized in Table 3.

[0163] [ka] (1-146)

[0164] [Example 32] An organic EL device was fabricated under the same conditions as in Example 21, except that the compound (1-147) of Example 12 was used as the capping layer 9 instead of the compound (1-7) of Example 1. The characteristics of the fabricated organic EL device were measured in air at room temperature. The light-emitting characteristics of the fabricated organic EL devices were measured by applying a DC voltage, and the results are summarized in Table 3.

[0165] [ka] (1-147)

[0166] [Example 33] An organic EL device was fabricated under the same conditions as in Example 21, except that the compound (1-148) of Example 13 was used as the capping layer 9 instead of the compound (1-7) of Example 1. The characteristics of the fabricated organic EL device were measured in air at room temperature. The light-emitting characteristics of the fabricated organic EL devices were measured by applying a DC voltage, and the results are summarized in Table 3.

[0167] [ka] (1-148)

[0168] [Example 34] An organic EL device was fabricated under the same conditions as in Example 21, except that the compound (1-149) of Example 14 was used as the capping layer 9 instead of the compound (1-7) of Example 1. The characteristics of the fabricated organic EL device were measured in air at room temperature. The light-emitting characteristics of the fabricated organic EL devices were measured by applying a DC voltage, and the results are summarized in Table 3.

[0169] [ka] (1-149)

[0170] [Example 35] An organic EL device was fabricated under the same conditions as in Example 21, except that the compound (1-150) of Example 15 was used as the capping layer 9 instead of the compound (1-7) of Example 1. The characteristics of the fabricated organic EL device were measured in air at room temperature. The light-emitting characteristics of the fabricated organic EL devices were measured by applying a DC voltage, and the results are summarized in Table 3.

[0171] [ka] (1-150)

[0172] [Example 36] An organic EL device was fabricated under the same conditions as in Example 21, except that the compound (1-151) of Example 16 was used as the capping layer 9 instead of the compound (1-7) of Example 1. The characteristics of the fabricated organic EL device were measured in air at room temperature. The light-emitting characteristics of the fabricated organic EL devices were measured by applying a DC voltage, and the results are summarized in Table 3.

[0173] [ka] (1-151)

[0174] [Example 37] An organic EL device was fabricated under the same conditions as in Example 21, except that the compound (1-152) of Example 17 was used as the capping layer 9 instead of the compound (1-7) of Example 1. The characteristics of the fabricated organic EL device were measured in air at room temperature. The light-emitting characteristics of the fabricated organic EL devices were measured by applying a DC voltage, and the results are summarized in Table 3.

[0175] [ka] (1-152)

[0176] [Example 38] An organic EL device was fabricated under the same conditions as in Example 21, except that the compound (1-153) of Example 18 was used as the capping layer 9 instead of the compound (1-7) of Example 1. The characteristics of the fabricated organic EL device were measured in air at room temperature. The light-emitting characteristics of the fabricated organic EL devices were measured by applying a DC voltage, and the results are summarized in Table 3.

[0177] [ka] (1-153)

[0178] [Comparative Example 1] For comparison, an organic EL device was fabricated under the same conditions as in Example 21, except that Alq3 was used as the capping layer 9 instead of the compound (1-7) in Example 1. The characteristics of the fabricated organic EL device were measured in the air at room temperature. The light-emitting characteristics of the fabricated organic EL devices were measured by applying a DC voltage, and the results are summarized in Table 3.

[0179] Comparative Example 2 For comparison, an organic EL device was fabricated under the same conditions as in Example 21, except that the comparative compound (2-1) was used as the capping layer 9 instead of the compound (1-7) in Example 1. The characteristics of the fabricated organic EL device were measured in the air at room temperature. The light-emitting characteristics of the fabricated organic EL devices were measured by applying a DC voltage, and the results are summarized in Table 3.

[0180] The organic EL devices fabricated in Examples 21 to 38 and Comparative Examples 1 and 2 were used to measure the device lifespan, and the results are summarized in Table 3. The device lifespan was 10 mA / cm 2 When the device was driven at a constant current of 100%, the time required for the initial luminance to decay to 95% (95% decay) was measured.

[0181] [Table 3]

[0182] As shown in Table 3, a current density of 10 mA / cm 2 The driving voltage at this time was almost the same for the devices of Comparative Examples 1 and 2 and the devices of Examples 21 to 38, which used the heterocyclic compound represented by general formula (1) of the present invention as a capping layer, whereas the brightness, luminous efficiency, power efficiency, and device life were significantly improved for the devices of Examples 21 to 38 compared to the devices of Comparative Examples 1 and 2. This indicates that the heterocyclic compound represented by general formula (1) of the present invention is a material suitable for use in a capping layer, and that the high refractive index of the capping layer can significantly improve the light extraction efficiency of an organic EL device. [Industrial Applicability]

[0183] The heterocyclic compound represented by general formula (1) of the present invention has a high refractive index, can significantly improve light extraction efficiency, and is stable in a thin film state, making it an excellent compound suitable for use as a capping layer in an organic EL device. Organic EL devices fabricated using the heterocyclic compound represented by general formula (1) of the present invention can achieve high efficiency. Furthermore, the use of the heterocyclic compound represented by general formula (1) of the present invention, which has no absorption in the blue, green, and red wavelength regions, is particularly suitable for displaying clear, bright images with good color purity. For example, this allows for applications in home appliances and lighting. [Explanation of symbols]

[0184] 1. Glass substrate 2 metal anode 3. Hole injection layer 4. Hole transport layer 5. Light-emitting layer 6 Electron transport layer 7 Electron injection layer 8 cathode 9 Capping Layer

Claims

1. A heterocyclic compound represented by the following general formula (1): 【Chemistry 1】 （１） (In the formula, X １ , X ２ may be the same or different and represent a nitrogen atom or a CH group, and at least one of X is a nitrogen atom. １ , X ２ When both of L and L are nitrogen atoms, １ , L ２ may be the same or different, and are a single bond, a divalent group obtained by removing two hydrogen atoms at the 1,4-positions of substituted or unsubstituted benzene, a divalent group obtained by removing two hydrogen atoms from substituted or unsubstituted biphenyl, a divalent group obtained by removing two hydrogen atoms from substituted or unsubstituted terphenyl, a divalent group obtained by removing two hydrogen atoms from substituted or unsubstituted naphthalene, a divalent group obtained by removing two hydrogen atoms from substituted or unsubstituted phenanthrene, a divalent group obtained by removing two hydrogen atoms from substituted or unsubstituted fluorene, a divalent group obtained by removing two hydrogen atoms from substituted or unsubstituted furan, a divalent group obtained by removing two hydrogen atoms from substituted or unsubstituted pyrrole, a divalent group obtained by removing two hydrogen atoms from substituted or unsubstituted thiophene, a divalent group obtained by removing two hydrogen atoms from substituted or unsubstituted quinoline, a divalent group obtained by removing two hydrogen atoms from substituted or unsubstituted benzofuran, a divalent group obtained by removing two hydrogen atoms from substituted or unsubstituted benzothiophene, a divalent group obtained by removing two hydrogen atoms from substituted or unsubstituted dibenzofuran, or a divalent group obtained by removing two hydrogen atoms from substituted or unsubstituted dibenzothiophene; １ , Ar ２ may be the same or different, and are a substituted or unsubstituted naphthyl group, a substituted or unsubstituted phenanthrenyl group, a substituted or unsubstituted fluorenyl group, a substituted or unsubstituted spirobifluorenyl group, a substituted or unsubstituted indenyl group, a substituted or unsubstituted pyrenyl group, a substituted or unsubstituted perylenyl group, a substituted or unsubstituted fluoranthenyl group, a substituted or unsubstituted triphenylenyl group, a substituted or unsubstituted pyridyl group, a substituted or unsubstituted pyrimidinyl group, a substituted or unsubstituted triazinyl group, a substituted or unsubstituted furyl group, or a substituted or unsubstituted pyrrolyl group. , a substituted or unsubstituted thienyl group, a substituted or unsubstituted quinolyl group, a substituted or unsubstituted isoquinolyl group, a substituted or unsubstituted benzofuranyl group, a substituted or unsubstituted benzothienyl group, a substituted or unsubstituted indolyl group, a substituted or unsubstituted quinoxalinyl group, a substituted or unsubstituted pyrazolyl group, a substituted or unsubstituted dibenzofuranyl group, a substituted or unsubstituted dibenzothienyl group, a substituted or unsubstituted naphthyridinyl group, a substituted or unsubstituted carbolinyl group, a substituted or unsubstituted benzoxazolyl group, or a substituted or unsubstituted benzothiazolyl group. １ , L ２ are not simultaneously single bonds, and at least one of them is a divalent group obtained by removing two hydrogen atoms at the 1,4-positions of an unsubstituted benzene, and Ar １ , Ar ２ When X has a substituent, the substituent is selected from a cyano group, a nitro group, a halogen atom, a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted alkyloxy group having 1 to 6 carbon atoms, a substituted or unsubstituted aromatic hydrocarbon group, and a substituted or unsubstituted aromatic heterocyclic group. １ , X ２ When only one of L is a nitrogen atom, １ , L ２ may be the same or different and represent a single bond, a divalent group obtained by removing two hydrogen atoms from the 1,4-positions of substituted or unsubstituted benzene, a divalent group obtained by removing two hydrogen atoms from substituted or unsubstituted biphenyl, a divalent group obtained by removing two hydrogen atoms from substituted or unsubstituted terphenyl, a divalent group obtained by removing two hydrogen atoms from substituted or unsubstituted naphthalene, a divalent group obtained by removing two hydrogen atoms from substituted or unsubstituted furan, a divalent group obtained by removing two hydrogen atoms from substituted or unsubstituted pyrrole, a divalent group obtained by removing two hydrogen atoms from substituted or unsubstituted thiophene, a divalent group obtained by removing two hydrogen atoms from substituted or unsubstituted quinoline, a divalent group obtained by removing two hydrogen atoms from substituted or unsubstituted benzofuran, or a divalent group obtained by removing two hydrogen atoms from substituted or unsubstituted benzothiophene; Ar １ , Ar ２ may be the same or different, and are each a substituted or unsubstituted naphthyl group, a substituted or unsubstituted phenanthrenyl group, a substituted or unsubstituted spirobifluorenyl group, a substituted or unsubstituted indenyl group, a substituted or unsubstituted perylenyl group, a substituted or unsubstituted fluoranthenyl group, a substituted or unsubstituted triphenylenyl group, a substituted or unsubstituted pyridyl group, a substituted or unsubstituted pyrimidinyl group, a substituted or unsubstituted triazinyl group, a substituted or unsubstituted furyl group, a substituted or unsubstituted or an unsubstituted pyrrolyl group, a substituted or unsubstituted thienyl group, a substituted or unsubstituted quinolyl group, a substituted or unsubstituted isoquinolyl group, a substituted or unsubstituted benzofuranyl group, a substituted or unsubstituted benzothienyl group, a substituted or unsubstituted quinoxalinyl group, a substituted or unsubstituted pyrazolyl group, a substituted or unsubstituted naphthyridinyl group, a substituted or unsubstituted carbolinyl group, a substituted or unsubstituted benzoxazolyl group, or a substituted or unsubstituted benzothiazolyl group. １ , L ２ are not simultaneously single bonds, and at least one of them is a divalent group obtained by removing two hydrogen atoms at the 1,4-positions of an unsubstituted benzene, and Ar １ , Ar ２ When has a substituent, the substituent is selected from a cyano group, a nitro group, a halogen atom, a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted alkyloxy group having 1 to 6 carbon atoms, a substituted or unsubstituted aromatic hydrocarbon group, and a substituted or unsubstituted aromatic heterocyclic group.

2. The heterocyclic compound according to claim 1, wherein the heterocyclic compound is represented by the following general formula (1-a): 【Chemistry 2】 (1-a) (In the formula, L 1, L ２ may be the same or different, and are a single bond, a divalent group obtained by removing two hydrogen atoms at the 1,4-positions of substituted or unsubstituted benzene, a divalent group obtained by removing two hydrogen atoms from substituted or unsubstituted biphenyl, a divalent group obtained by removing two hydrogen atoms from substituted or unsubstituted terphenyl, a divalent group obtained by removing two hydrogen atoms from substituted or unsubstituted naphthalene, a divalent group obtained by removing two hydrogen atoms from substituted or unsubstituted phenanthrene, a divalent group obtained by removing two hydrogen atoms from substituted or unsubstituted fluorene, a divalent group obtained by removing two hydrogen atoms from substituted or unsubstituted furan, a divalent group obtained by removing two hydrogen atoms from substituted or unsubstituted pyrrole, a divalent group obtained by removing two hydrogen atoms from substituted or unsubstituted thiophene, a divalent group obtained by removing two hydrogen atoms from substituted or unsubstituted quinoline, a divalent group obtained by removing two hydrogen atoms from substituted or unsubstituted benzofuran, a divalent group obtained by removing two hydrogen atoms from substituted or unsubstituted benzothiophene, a divalent group obtained by removing two hydrogen atoms from substituted or unsubstituted dibenzofuran, or a divalent group obtained by removing two hydrogen atoms from substituted or unsubstituted dibenzothiophene; １ , Ar ２ may be the same or different, and are a substituted or unsubstituted naphthyl group, a substituted or unsubstituted phenanthrenyl group, a substituted or unsubstituted fluorenyl group, a substituted or unsubstituted spirobifluorenyl group, a substituted or unsubstituted indenyl group, a substituted or unsubstituted pyrenyl group, a substituted or unsubstituted perylenyl group, a substituted or unsubstituted fluoranthenyl group, a substituted or unsubstituted triphenylenyl group, a substituted or unsubstituted pyridyl group, a substituted or unsubstituted pyrimidinyl group, a substituted or unsubstituted triazinyl group, a substituted or unsubstituted furyl group, or a substituted or unsubstituted pyrrolyl group. , a substituted or unsubstituted thienyl group, a substituted or unsubstituted quinolyl group, a substituted or unsubstituted isoquinolyl group, a substituted or unsubstituted benzofuranyl group, a substituted or unsubstituted benzothienyl group, a substituted or unsubstituted indolyl group, a substituted or unsubstituted quinoxalinyl group, a substituted or unsubstituted pyrazolyl group, a substituted or unsubstituted dibenzofuranyl group, a substituted or unsubstituted dibenzothienyl group, a substituted or unsubstituted naphthyridinyl group, a substituted or unsubstituted carbolinyl group, a substituted or unsubstituted benzoxazolyl group, or a substituted or unsubstituted benzothiazolyl group. １ , L ２ are not simultaneously single bonds, and at least one of them is a divalent group obtained by removing two hydrogen atoms at the 1,4-positions of an unsubstituted benzene, and Ar １ , Ar ２ When has a substituent, the substituent is selected from a cyano group, a nitro group, a halogen atom, a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted alkyloxy group having 1 to 6 carbon atoms, a substituted or unsubstituted aromatic hydrocarbon group, and a substituted or unsubstituted aromatic heterocyclic group.

3. The heterocyclic compound according to claim 1, wherein the heterocyclic compound is represented by the following general formula (1-b): 【Transformation 3】 (1-b) (In the formula, L 1, L ２ may be the same or different and represent a single bond, a divalent group obtained by removing two hydrogen atoms from the 1,4-positions of substituted or unsubstituted benzene, a divalent group obtained by removing two hydrogen atoms from substituted or unsubstituted biphenyl, a divalent group obtained by removing two hydrogen atoms from substituted or unsubstituted terphenyl, a divalent group obtained by removing two hydrogen atoms from substituted or unsubstituted naphthalene, a divalent group obtained by removing two hydrogen atoms from substituted or unsubstituted furan, a divalent group obtained by removing two hydrogen atoms from substituted or unsubstituted pyrrole, a divalent group obtained by removing two hydrogen atoms from substituted or unsubstituted thiophene, a divalent group obtained by removing two hydrogen atoms from substituted or unsubstituted quinoline, a divalent group obtained by removing two hydrogen atoms from substituted or unsubstituted benzofuran, or a divalent group obtained by removing two hydrogen atoms from substituted or unsubstituted benzothiophene; Ar １ , Ar ２ may be the same or different, and are each a substituted or unsubstituted naphthyl group, a substituted or unsubstituted phenanthrenyl group, a substituted or unsubstituted spirobifluorenyl group, a substituted or unsubstituted indenyl group, a substituted or unsubstituted perylenyl group, a substituted or unsubstituted fluoranthenyl group, a substituted or unsubstituted triphenylenyl group, a substituted or unsubstituted pyridyl group, a substituted or unsubstituted pyrimidinyl group, a substituted or unsubstituted triazinyl group, a substituted or unsubstituted furyl group, a substituted or unsubstituted or an unsubstituted pyrrolyl group, a substituted or unsubstituted thienyl group, a substituted or unsubstituted quinolyl group, a substituted or unsubstituted isoquinolyl group, a substituted or unsubstituted benzofuranyl group, a substituted or unsubstituted benzothienyl group, a substituted or unsubstituted quinoxalinyl group, a substituted or unsubstituted pyrazolyl group, a substituted or unsubstituted naphthyridinyl group, a substituted or unsubstituted carbolinyl group, a substituted or unsubstituted benzoxazolyl group, or a substituted or unsubstituted benzothiazolyl group. １ , L ２ are not simultaneously single bonds, and at least one of them is a divalent group obtained by removing two hydrogen atoms at the 1,4-positions of an unsubstituted benzene, and Ar １ , Ar ２ When has a substituent, the substituent is selected from a cyano group, a nitro group, a halogen atom, a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted alkyloxy group having 1 to 6 carbon atoms, a substituted or unsubstituted aromatic hydrocarbon group, and a substituted or unsubstituted aromatic heterocyclic group.

4. 4. An organic thin film comprising the heterocyclic compound according to claim 1, wherein the organic thin film has a refractive index of 1.70 or more in a wavelength range of 450 nm to 750 nm.

5. 5. An organic electroluminescence device having at least an anode electrode, a hole transport layer, a light-emitting layer, an electron transport layer, a cathode electrode, and a capping layer in this order, wherein the capping layer is the organic thin film according to claim 4.

6. An electronic device or an electronic element having a pair of electrodes and at least one organic layer sandwiched between them, wherein the heterocyclic compound according to any one of claims 1 to 3 is used as a constituent material of the organic layer.

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