Compound, organic electroluminescent element, and electronic device

Abstract

To provide a material for an organic EL element excellent in hole transport ability and electron blocking ability and having high thermal stability in a thin film state.SOLUTION: The compound is represented by general formula (1). X1 is a group represented by the general formula (2); Ar1 to Ar3 are aromatic hydrocarbyl groups or aromatic heterocyclic groups; R1 to R8 are hydrogen atoms or deuterium atoms; R9 to R12 are hydrogen atoms, deuterium atoms, alkyl groups, or the like; and n is 1 or 2.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a compound useful as an electron blocking material, a hole transporting material, or the like, and to an organic electroluminescence device (hereinafter abbreviated as organic EL device) and an electronic device using the compound. [Background technology]

[0002] Organic EL elements are self-luminous elements, and therefore are brighter and more visible than liquid crystal elements, enabling clearer displays, and therefore active research has been conducted on them.

[0003] In 1987, C.W. Tang and his colleagues at Eastman Kodak Company developed a layered structure element in which various roles were assigned to each material as a practical organic EL element. Specifically, they layered a phosphor capable of transporting electrons and an organic material capable of transporting holes, and by injecting both charges into the phosphor layer to emit light, they achieved an intensity of 1000 cd / m at a voltage of 10 V or less. 2 Such high brightness has been achieved (see, for example, Patent Documents 1 and 2).

[0004] To date, many improvements have been made to the practical application of organic EL devices, and the various roles of the laminated structure have been further subdivided, with high efficiency and durability being achieved by using a laminated structure 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 provided in this order on a substrate (see, for example, Non-Patent Document 1).

[0005] Furthermore, attempts have been made to utilize triplet excitons in order to further improve luminous efficiency, and the use of phosphorescent compounds has been investigated (see, for example, Non-Patent Document 2). Furthermore, devices that utilize luminescence due to thermally activated delayed fluorescence (TADF) have also been developed, and in 2011, Adachi et al. of Kyushu University achieved an external quantum efficiency of 5.3% using a device that uses a thermally activated delayed fluorescence material (see, for example, Non-Patent Document 3).

[0006] The light-emitting layer of these organic EL devices is generally prepared by doping a charge-transporting compound, generally referred to as a host material, with a fluorescent compound, a phosphorescent compound, or a material that emits delayed fluorescence. As described in the above non-patent documents, various organic layers are provided in organic EL devices, and the selection of the organic materials significantly affects various properties of the device, such as efficiency and durability (see, for example, non-patent documents 1 to 3).

[0007] That is, in organic EL devices, charges injected from both electrodes recombine in the light-emitting layer to produce light emission. Therefore, it is important to efficiently transfer both charges, holes and electrons, to the light-emitting layer, and it is necessary to create devices with excellent carrier balance. For example, by using a material that has hole injection properties, which supply holes injected from the anode to the light-emitting layer, and electron blocking properties, which block electrons injected from the cathode, the probability of holes and electrons recombining in the light-emitting layer can be improved, and by further confining excitons generated in the light-emitting layer, high luminous efficiency can be achieved. Therefore, hole-transport materials are required to have high hole mobility, high electron blocking properties, and high durability against electrons.

[0008] Furthermore, the heat resistance and amorphous nature of the material are also important factors in determining the lifespan of the element. Materials with low heat resistance will undergo thermal decomposition even at low temperatures due to the heat generated when the element is in operation, causing the material to deteriorate. Materials with low amorphous nature will undergo crystallization of the thin film even in a short period of time, causing the element to deteriorate. For this reason, the materials used must have high heat resistance and good amorphous nature.

[0009] Hole transport materials that have been used in organic EL devices to date include N,N'-diphenyl-N,N'-di(α-naphthyl)benzidine (NPD) and various aromatic amine derivatives (see, for example, Patent Document 1 and Patent Document 2). However, although NPD has good hole transport capabilities, its glass transition temperature (Tg), which is an indicator of heat resistance, is as low as 96°C, and crystallization occurs under high-temperature conditions, causing a deterioration in device characteristics (see, for example, Non-Patent Document 4).

[0010] In addition, some of the aromatic amine derivatives mentioned above have hole mobilities of 10 -3 cm 2 Although there are compounds with excellent mobility of 1 / Vs or more (see, for example, Patent Documents 1 and 2), their electron blocking properties are insufficient, so some electrons pass through the light-emitting layer, and improvement in luminous efficiency cannot be expected. Therefore, to achieve even higher efficiency, materials with better electron blocking properties, more stable thin films, and high heat resistance are required. In addition, highly durable aromatic amine derivatives have been reported (see, for example, Patent Document 3), but these were used as charge transport materials in electrophotographic photoreceptors, and there have been no examples of their use in organic EL devices.

[0011] In order to solve this problem, substituted carbazole structures and arylamine compounds have been proposed as compounds with improved properties such as heat resistance and hole injection properties (see, for example, Patent Documents 4 and 5). However, in devices using these compounds in the hole injection layer or hole transport layer, although improvements have been made in the device life and luminous efficiency, these improvements are still insufficient, and there is a demand for further reductions in driving voltage, improvements in luminous efficiency, and longer device life. [Prior art documents] [Patent documents]

[0012] [Patent Document 1] U.S. Patent No. 5,792,557 [Patent Document 2] U.S. Patent No. 5,639,914 [Patent Document 3] U.S. Patent No. 7,759,030 [Patent Document 4] Patent Publication No. 2009-076817 [Patent Document 5] Patent No. 7177966 [Patent Document 6] European Patent No. 2684932 [Non-patent literature]

[0013] [Non-Patent Document 1] Proceedings of the 9th Seminar of the Japan Society of Applied Physics, pp. 55-61 (2001) [Non-patent document 2] Proceedings of the 9th Seminar of the Japan Society of Applied Physics, pp. 23-31 (2001) [Non-patent document 3] Appl.Phys.Let.,98,083302(2011) [Non-patent document 4] Proceedings of the 3rd Regular Meeting of the Organic EL Symposium, pages 13-14 (2006) Summary of the Invention [Problem to be solved by the invention]

[0014] As mentioned above, various organic compounds have been proposed as materials for organic EL devices. However, no compound has been developed that has both excellent hole transporting and electron blocking properties and high thermal stability. The object of the present invention is to provide a material for an organic EL device that has excellent hole transporting ability and electron blocking ability, and high thermal stability in a thin film state, and also to provide an organic EL device that has a low driving voltage, high luminous efficiency and power efficiency, and a long device life. [Means for solving the problem]

[0015] The present inventors have conducted extensive research to achieve the above object and have found that a compound having a specific structure has excellent hole transporting ability and electron blocking ability, and is also highly stable in a thin film state. They have also found that the use of this compound makes it possible to realize an organic electroluminescent device with high luminous efficiency and power efficiency, reduced light-emission starting voltage and practical driving voltage, and a longer life than conventional devices. The present invention has been completed based on these findings and specifically has the following configuration.

[0016] That is, according to the present invention, the following compounds and organic EL devices and electronic devices using the same are provided.

[0017] 1) A compound represented by the following general formula (1):

[0018] [ka]

[0019] [In general formula (1), Ar1 and Ar2 may be the same or different from each other, a substituted or unsubstituted aromatic hydrocarbon group, or represents a substituted or unsubstituted aromatic heterocyclic group, X1 represents a group represented by the following general formula (2): [ka] [In the general formula (2), Ar3 is a substituted or unsubstituted aromatic hydrocarbon group, or represents a substituted or unsubstituted aromatic heterocyclic group, R1 to R8 may be the same or different and each represent a hydrogen atom or a deuterium atom; R9~R 12 may be the same or different and represent a hydrogen atom, a deuterium atom, a fluorine atom, a chlorine atom, a cyano group, a nitro group, a substituted or unsubstituted linear or branched alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted cycloalkyl group having 5 to 10 carbon atoms, a substituted or unsubstituted linear or branched alkenyl group having 2 to 6 carbon atoms, a substituted or unsubstituted linear or branched alkyloxy group having 1 to 6 carbon atoms, a substituted or unsubstituted cycloalkyloxy group having 5 to 10 carbon atoms, or a substituted or unsubstituted aryloxy group having 6 to 30 carbon atoms; n represents an integer of 1 or 2, and when n is 2, multiple R5 to R8 may be the same or different. However, when n is 1 and Ar1 and Ar2 are both unsubstituted biphenylyl groups, Ar3 is a substituted or unsubstituted fused aromatic hydrocarbon group, or a substituted or unsubstituted aromatic heterocyclic group. * represents the bonding position to N in general formula (1).

[0020] 2) The compound according to 1) above, wherein, in the above general formula (1), Ar1 and Ar2 may be the same or different and are a substituted or unsubstituted phenyl group, a substituted or unsubstituted biphenylyl group, a substituted or unsubstituted terphenylyl group, a substituted or unsubstituted naphthyl group, a substituted or unsubstituted phenanthrenyl group, a substituted or unsubstituted carbazolyl group, a substituted or unsubstituted dibenzofuranyl group, a substituted or unsubstituted dibenzothienyl group, or a substituted or unsubstituted fluorenyl group.

[0021] 3) In the above general formula (2), R9 to R 12 The compound according to 1) or 2) above, wherein each of may be the same or different and is a hydrogen atom or a deuterium atom.

[0022] 3a) In the above general formula (2), R9 to R 12 The compound according to 1) or 2) above, wherein neither of the above groups contains a polymerizable group.

[0023] 4) The compound according to any one of 1) to 3a) above, wherein, in the general formula (2), Ar3 is a substituted or unsubstituted phenyl group, a substituted or unsubstituted biphenylyl group, a substituted or unsubstituted terphenylyl group, a substituted or unsubstituted naphthyl group, a substituted or unsubstituted phenanthrenyl group, a substituted or unsubstituted carbazolyl group, a substituted or unsubstituted dibenzofuranyl group, a substituted or unsubstituted dibenzothienyl group, or a substituted or unsubstituted fluorenyl group.

[0024] 5) The compound according to 4) above, wherein in the general formula (1), Ar3 is a substituted or unsubstituted phenyl group, a substituted or unsubstituted biphenylyl group, or a substituted or unsubstituted naphthyl group.

[0025] 6) The present invention also provides an organic EL device having a pair of electrodes and at least one organic layer sandwiched between them, wherein the organic layer contains the compound according to any one of 1) to 5) above.

[0026] 7) The organic EL device according to the above 6), wherein the organic layer is a hole transport layer.

[0027] 8) The organic EL device according to the above 6), wherein the organic layer is an electron blocking layer.

[0028] 9) The organic EL device according to the above 6), wherein the organic layer is a hole injection layer.

[0029] 10) An electronic device having a pair of electrodes and at least one organic layer sandwiched between them, wherein the organic layer contains the compound according to any one of 1) to 5) above. [Effects of the Invention]

[0030] The compound of the present invention has excellent hole transporting ability and electron blocking ability, and also has high thermal stability in a thin film state, so it is useful as an electron blocking material or a hole transporting material. Organic EL devices using the compound of the present invention as a material for the organic layer can achieve low driving voltage, high luminous efficiency, and long device life. [Brief explanation of the drawings]

[0031] [Figure 1] FIG. 1 is a schematic cross-sectional view showing the layer structure of the organic EL devices fabricated in Examples 1 to 8 and Comparative Example 1. DETAILED DESCRIPTION OF THE INVENTION

[0032] The present invention will be described in detail below. The following description of the constituent elements may be based on typical embodiments or specific examples of the present invention, but the present invention is not limited to such embodiments or specific examples. In this specification, a numerical range expressed using "to" means a range including the numerical values ​​before and after "to" as the lower and upper limits. In addition, the isotopes of hydrogen atoms present in the molecules of the compound used in the present invention are not particularly limited, and for example, all hydrogen atoms in the molecule may be 1 H, or part or all of 2H (deuterium D). In this specification, the term "substituted or unsubstituted" means that the group to which the term is attached may be an unsubstituted group (a group in which a hydrogen atom is not substituted with a substituent), or at least one hydrogen atom of the group may be substituted with a substituent.

[0033] <Compound represented by general formula (1)> The compound represented by general formula (1) of the present invention will be described in detail below.

[0034] The aromatic ring constituting the "aromatic hydrocarbon group" in the "substituted or unsubstituted aromatic hydrocarbon group" represented by Ar1 and Ar2 in general formula (1) may be a monocyclic ring, a fused ring in which two or more rings are fused (fused polycyclic aromatic hydrocarbon group), a linked ring in which two or more aromatic rings, which may be fused, are linked by a single bond, a linked ring in which two or more rings are linked by a single bond, or a spiro ring in which two or more rings are linked by a spiro bond. The number of carbon atoms in the aromatic ring is selected, for example, from 6 to 30. Specific examples of the "aromatic hydrocarbon group" (aryl group) include aromatic hydrocarbon groups in which no ring is fused, such as a phenyl group, a biphenylyl group, or a terphenylyl group, and fused polycyclic aromatic hydrocarbon groups such as a naphthyl group, an anthracenyl group, a phenanthrenyl group, an indenyl group, a pyrenyl group, a perylenyl group, a fluoranthenyl group, a triphenylenyl group, a fluorenyl group, or a spirobifluorenyl group.

[0035] The "aromatic heterocyclic group" (heteroaryl group) in the "substituted or unsubstituted aromatic heterocyclic group" represented by Ar1 and Ar2 in general formula (1) may be a monocyclic ring or a fused ring (fused polycyclic aromatic heterocyclic group) in which a heterocyclic ring is fused with one or more rings. The number of carbon atoms in the aromatic heterocyclic ring is selected from, for example, 2 to 40, and may also be selected from the range of 2 to 20. Specific examples of the "aromatic heterocyclic group" include aromatic heterocyclic groups in which the rings are not condensed, such as a pyridyl group, a pyrimidinyl group, a triazinyl group, a furyl group, a pyrrolyl group, a thienyl group, a quinolyl group, an isoquinolyl group, and a pyrazolyl group, and condensed polycyclic aromatic heterocyclic groups, such as a benzofuranyl group, a benzothienyl group, an indolyl group, a carbazolyl group, a benzoxazolyl group, a benzothiazolyl group, an azafluorenyl group, a diazafluorenyl group, an azaspirobifluorenyl group, a diazaspirobifluorenyl group, a quinoxalinyl group, a benzimidazolyl group, a dibenzofuranyl group, a dibenzothienyl group, a naphthyridinyl group, a phenanthrolinyl group, an acridinyl group, and a carbolinyl group.

[0036] Examples of the "substituent" in the "substituted aromatic hydrocarbon group" and "substituted aromatic heterocyclic group" represented by Ar1 and Ar2 in general formula (1) include a deuterium atom, a cyano group, a nitro group; a halogen atom such as a fluorine atom, a chlorine atom, a bromine atom, or an iodine atom; a silyl group such as a trimethylsilyl group or a triphenylsilyl group; a linear or branched alkyl group having 1 to 6 carbon atoms such as a methyl group, an ethyl group, or a propyl group; a linear or branched alkyloxy group having 1 to 6 carbon atoms such as a methyloxy group, an ethyloxy group, or a propyloxy group; an alkenyl group having 2 to 6 carbon atoms such as a vinyl group or an allyl group; an aryloxy group having 6 to 30 carbon atoms such as a phenyloxy group or a tolyloxy group; an arylalkyloxy group having 7 to 36 carbon atoms such as a benzyloxy group or a phenethyloxy group; a phenyl group, a biphenyl group, or a phenyl group. Examples of aromatic hydrocarbon groups having 6 to 30 carbon atoms (including condensed polycyclic aromatic groups) include aromatic hydrocarbon groups having 6 to 30 carbon atoms such as a pyridyl group, a terphenylyl 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; and aromatic heterocyclic groups having 5 to 30 carbon atoms (including condensed polycyclic aromatic heterocyclic groups) such as a pyridyl group, a thienyl group, a furyl group, a pyrrolyl group, a quinolyl group, an isoquinolyl group, a benzofuranyl group, a benzothienyl group, an indolyl group, a carbazolyl group, a benzoxazolyl group, a benzothiazolyl group, a quinoxalinyl group, a benzimidazolyl group, a pyrazolyl group, a dibenzofuranyl group, a dibenzothienyl group, and a carbolinyl group, and the hydrogen atoms of these substituents may be further substituted with the substituents exemplified herein. In some embodiments of the present invention, the substituent is selected from the group consisting of a deuterium atom, a silyl group, a linear or branched alkyl group having 1 to 6 carbon atoms, an aromatic hydrocarbon group having 6 to 30 carbon atoms, and an aromatic heterocyclic group having 5 to 30 carbon atoms. In some embodiments of the present invention, the substituent is a deuterium atom or a linear or branched alkyl group having 1 to 6 carbon atoms. In addition, when a hydrogen atom of a substituent is further substituted with a substituent, the substituent directly substituted on the parent skeleton (aromatic hydrocarbon group, aromatic heterocyclic group) is referred to as the "first substituent," and the substituent substituted on the first substituent is referred to as the "second substituent." Here, when the first substituent contains a benzene ring, the benzene ring may be bonded to the parent skeleton to form a cyclic structure. Furthermore, when two or more second substituents are substituted on the benzene ring of the first substituent, adjacent second substituents may be bonded to each other to form a cyclic structure. Here, the bond between the benzene ring and the parent skeleton in the first substituent and the bond between the second substituents may be a single bond or a bond via a linking group. Examples of the linking group include a substituted or unsubstituted methylene group, an oxygen atom, or a sulfur atom.

[0037] Ar1 and Ar2 may be the same or different. In some embodiments of the present invention, Ar1 and Ar2 have different chemical structures. In some embodiments of the present invention, Ar1 and Ar2 are both linked rings in which two or more aromatic rings are linked by a single bond. In some embodiments of the present invention, Ar1 and Ar2 are both linked rings in which two or more aromatic rings are linked by a single bond, but have different chemical structures. In some embodiments of the present invention, one of Ar1 and Ar2 is a substituted or unsubstituted aromatic hydrocarbon group, and the other is a group containing a substituted or unsubstituted aromatic heterocycle. In some embodiments of the present invention, at least one of Ar1 and Ar2 is a substituted or unsubstituted fused polycyclic aromatic hydrocarbon group. In some embodiments of the present invention, at least one of Ar1 and Ar2 is a substituted or unsubstituted terphenylyl group. In some embodiments of the present invention, at least one of Ar1 and Ar2 is a group containing a deuterium atom.

[0038] X1 in the general formula (1) is a group represented by the general formula (2) above. The * portion in general formula (2) is the bonding site to the N atom in general formula (1).

[0039] For the "aromatic hydrocarbon group" and "aromatic heterocyclic group" in the "substituted or unsubstituted aromatic hydrocarbon group" and "substituted or unsubstituted aromatic heterocyclic group" represented by Ar3 in general formula (2), reference can be made to the explanations and specific examples of the "substituted or unsubstituted aromatic hydrocarbon group" and "substituted or unsubstituted aromatic heterocyclic group" represented by Ar1 and Ar2 in general formula (1). Regarding the "substituent", reference can be made to the explanations and specific examples of the "substituent" in the "substituted aromatic hydrocarbon group" and "substituted aromatic heterocyclic group" represented by Ar1 and Ar2 in general formula (1). In the present invention, the substituent of Ar3 is preferably a deuterium atom, a silyl group, a linear or branched alkyl group having 1 to 6 carbon atoms, an aromatic hydrocarbon group having 6 to 30 carbon atoms, or an aromatic heterocyclic group having 5 to 30 carbon atoms.

[0040] R9 to R in general formula (2) 12 Specific examples of the "C1-C6 linear or branched alkyl group" in the "substituted or unsubstituted C1-C6 linear or branched alkyl group" represented by R1 to R3 include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, neopentyl, and n-hexyl. Specific examples of the "C5-C10 cycloalkyl group" in the "substituted or unsubstituted C5-C10 cycloalkyl group" represented by R1 to R3 include cyclopentyl, cyclohexyl, 1-adamantyl, and 2-adamantyl. Specific examples of the "C2-C6 linear or branched alkenyl group" in the "substituted or unsubstituted C2-C6 linear or branched alkenyl group" represented by R1 to R3 include vinyl, allyl, isopropenyl, and 2-butenyl. In addition, benzene rings substituted with these substituents, or multiple substituents substituted on the same benzene ring, may be bonded to each other via a single bond, a substituted or unsubstituted methylene group, a substituted or unsubstituted amino group, an oxygen atom, or a sulfur atom to form a ring.

[0041] R9 to R in general formula (2) 12 Specific examples of the "straight-chain or branched alkyloxy group having 1 to 6 carbon atoms" in the "substituted or unsubstituted, straight-chain or branched alkyloxy group having 1 to 6 carbon atoms" represented by the formula (I) include a methyloxy group, an ethyloxy group, an n-propyloxy group, an isopropyloxy group, an n-butyloxy group, a tert-butyloxy group, an n-pentyloxy group, and an n-hexyloxy group. Specific examples of the "cycloalkyloxy group having 5 to 10 carbon atoms" in the "substituted or unsubstituted cycloalkyloxy group having 5 to 10 carbon atoms" represented by R1 to R3 include a cyclopentyloxy group, a cyclohexyloxy group, a cycloheptyloxy group, a cyclooctyloxy group, a 1-adamantyloxy group, and a 2-adamantyloxy group. Benzene rings substituted with these substituents, or multiple substituents substituted on the same benzene ring, may be bonded to each other via a single bond, a substituted or unsubstituted methylene group, a substituted or unsubstituted amino group, an oxygen atom, or a sulfur atom to form a ring.

[0042] R9 to R in general formula (2) 12 Examples of the "aryloxy group" in the "substituted or unsubstituted aryloxy group" represented by the formula (I) include aryloxy groups having 6 to 30 carbon atoms, such as a phenyloxy group, a biphenylyloxy group, a terphenylyloxy group, a naphthyloxy group, an anthracenyloxy group, a phenanthrenyloxy group, a fluorenyloxy group, a spirobifluorenyloxy group, an indenyloxy group, a pyrenyloxy group, a perylenyloxy group, a fluoranthenyloxy group, and a triphenylenyloxy group. Benzene rings substituted with these substituents, or multiple substituents substituted on the same benzene ring, may be bonded to each other via a single bond, a substituted or unsubstituted methylene group, a substituted or unsubstituted amino group, an oxygen atom, or a sulfur atom to form a ring.

[0043] R9 to R in general formula (2) 12For the "substituents" in the "substituted linear or branched alkyl group having 1 to 6 carbon atoms," "substituted cycloalkyl group having 5 to 10 carbon atoms," "substituted linear or branched alkenyl group having 2 to 6 carbon atoms," "substituted linear or branched alkyloxy group having 1 to 6 carbon atoms," "substituted cycloalkyloxy group having 5 to 10 carbon atoms," and "substituted aryloxy group" represented by the above, reference can be made to the explanations and specific examples of the "substituents" in the "substituted aromatic hydrocarbon group" and "substituted aromatic heterocyclic group" represented by Ar1 and Ar2 in general formula (1).

[0044] In some embodiments of the present invention, R9 to R 12 are not bonded to each other to form a ring. In some embodiments of the present invention, R9 to R 12 In some embodiments of the present invention, R9 to R 12 may be the same or different and are a hydrogen atom, a deuterium atom, a fluorine atom, a chlorine atom, a cyano group, a nitro group, a linear or branched alkyl group of 1 to 6 carbon atoms which may be substituted with a non-polymerizable group, a cycloalkyl group of 5 to 10 carbon atoms which may be substituted with a non-polymerizable group, a linear or branched alkyloxy group of 1 to 6 carbon atoms which may be substituted with a non-polymerizable group, a cycloalkyloxy group of 5 to 10 carbon atoms which may be substituted with a non-polymerizable group, or an aryloxy group which may be substituted with a non-polymerizable group. In some embodiments of the present invention, R9 to R 12 are each independently a hydrogen atom or a deuterium atom.

[0045] Ar1 and Ar2 in general formula (1) are preferably a substituted or unsubstituted phenyl group, a substituted or unsubstituted biphenylyl group, a substituted or unsubstituted terphenylyl group, a substituted or unsubstituted naphthyl group, a substituted or unsubstituted fluorenyl group, a substituted or unsubstituted phenanthrenyl group, a substituted or unsubstituted carbazolyl group, a substituted or unsubstituted dibenzothienyl group, or a substituted or unsubstituted dibenzofuranyl group, and more preferably a substituted or unsubstituted biphenylyl group or a substituted or unsubstituted terphenylyl group. Preferably, either Ar1 or Ar2 has a substituted or unsubstituted terphenylyl group, and more preferably, either Ar1 or Ar2 is a substituted or unsubstituted terphenylyl group.

[0046] Ar3 in general formula (2) is preferably a substituted or unsubstituted phenyl group, a substituted or unsubstituted biphenylyl group, a substituted or unsubstituted terphenylyl group, a substituted or unsubstituted naphthyl group, a substituted or unsubstituted phenanthrenyl group, a substituted or unsubstituted triphenylsilyl group, a substituted or unsubstituted carbazolyl group, a substituted or unsubstituted dibenzofuranyl group, a substituted or unsubstituted dibenzothienyl group, or a substituted or unsubstituted fluorenyl group, and more preferably a substituted or unsubstituted phenyl group, a substituted or unsubstituted biphenylyl group, or a substituted or unsubstituted naphthyl group.

[0047] R9 to R in general formula (2) 12 is preferably a hydrogen atom, a deuterium atom, a substituted or unsubstituted linear or branched alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted linear or branched alkenyl group having 2 to 6 carbon atoms, a substituted or unsubstituted linear or branched alkyloxy group having 1 to 6 carbon atoms, or a substituted or unsubstituted aryloxy group having 6 to 30 carbon atoms, and more preferably a hydrogen atom or a deuterium atom.

[0048] In general formula (2), R1 to R8 may be the same or different and each represent a hydrogen atom or a deuterium atom, and n represents an integer of 1 or 2. R1 to R8 may all be hydrogen atoms, some may be hydrogen atoms and the rest may be deuterium atoms, or all may be deuterium atoms. Furthermore, for example, when n is 1, R1 to R4 may be deuterium atoms and R5 to R8 may be hydrogen atoms, or R1 to R4 may be hydrogen atoms and R5 to R8 may be deuterium atoms. Furthermore, for example, when n is 2, R1 to R4 may be deuterium atoms and all of R5 to R8 of the multiple phenylene groups may be hydrogen atoms, or only R5 to R8 of one phenylene group may be deuterium atoms, or all of R5 to R8 of the multiple phenylene groups may be deuterium atoms.

[0049] In addition, in general formula (2), when n is 1 and Ar1 and Ar2 are both unsubstituted biphenylyl groups, Ar3 is a substituted or unsubstituted fused aromatic hydrocarbon group, or a substituted or unsubstituted aromatic heterocyclic group. That is, in general formula (2), when n is 1 and Ar1 and Ar2 are both unsubstituted biphenylyl groups, Ar3 is not an aromatic hydrocarbon group whose rings are not fused. Furthermore, when n is 1, Ar3 is a substituted or unsubstituted aromatic hydrocarbon group having no fused rings, and either Ar1 or Ar2 is an unsubstituted biphenylyl group, it is preferable that the other Ar1 or Ar2 is a substituted or unsubstituted terphenylyl group.

[0050] [Method for synthesizing the compound represented by general formula (1) and method for evaluating its properties] The compound of the present invention represented by general formula (1) is a novel compound. The compound represented by formula (1) can be synthesized according to a known method. For details of the synthesis method, reference can be made to the method described in Japanese Patent No. 7177966 (Patent Document 5) and the synthesis examples described below. The compound represented by general formula (1) can be purified by known methods such as purification by column chromatography, adsorption purification using silica gel, activated carbon, activated clay, etc., recrystallization or crystallization using a solvent, sublimation purification, etc. The compound can be identified by NMR analysis.

[0051] Specific examples of preferred compounds among the compounds represented by general formula (1) are shown below. However, the compounds represented by general formula (1) that can be used in the present invention should not be construed as being limited by these specific examples. In addition, in the following chemical structural formula, a hydrogen atom ( 1 H) is omitted. Also, D is a deuterium atom ( 2 H). In the compound represented by general formula (1), some or all of the hydrogen atoms in the exemplified structure may be substituted with deuterium atoms. For example, when Ar1 or Ar2 is a substituted biphenyl group, it may be a deuterium-substituted biphenyl group. In R1 to R8, for example, R1 to R4 may be deuterium atoms and R5 to R8 may be hydrogen atoms.

[0052] [ka]

[0053] [ka]

[0054] [ka]

[0055] [ka]

[0056] [ka]

[0057] [ka]

[0058] [ka]

[0059] [ka]

[0060] [Method for synthesizing the compound represented by general formula (1) and method for evaluating its properties] The compound of the present invention represented by general formula (1) is a novel compound. The compound represented by formula (1) can be synthesized according to a known method. For details of the synthesis method, reference can be made to the method described in Japanese Patent No. 7177966 (Patent Document 5) and the synthesis examples described below. The compound represented by general formula (1) can be purified by known methods such as purification by column chromatography, adsorption purification using silica gel, activated carbon, activated clay, etc., recrystallization or crystallization using a solvent, sublimation purification, etc. The compound can be identified by NMR analysis.

[0061] [Usefulness of the compound represented by general formula (1)] The compound represented by general formula (1) of the present invention has excellent hole transporting ability and electron blocking ability, and is highly thermally stable in a thin film state, making it useful as a material for the organic layer of an organic electroluminescent device. The compound represented by general formula (1) can be used, for example, as a constituent material for the hole injection layer, electron blocking layer, hole transport layer, and light-emitting layer of an organic electroluminescent device, and is particularly useful as a constituent material for the electron blocking layer and hole transport layer. An organic EL device containing a compound represented by general formula (1) in an organic layer (e.g., at least one of the electron blocking layer, hole transport layer, and light-emitting layer) can achieve high luminous efficiency, high power efficiency, and a long device life.

[0062] Physical properties that can be used as indicators of the usefulness of the compound represented by general formula (1) include measurements of the melting point, glass transition temperature (Tg), and HOMO energy level (work function). The melting point is an indicator of vapor deposition properties, the glass transition temperature (Tg) is an indicator of the stability of the thin film state, and the HOMO energy level is an indicator of hole injection properties, hole transport properties, or electron blocking properties.

[0063] The melting point and glass transition temperature (Tg) can be measured, for example, by using a powder of the compound to be measured with a high-sensitivity differential scanning calorimeter (manufactured by Rigaku, DSCvesta Thermo plus EV02 series).

[0064] The HOMO energy level can be determined, for example, by forming a 100 nm-thick thin film of the compound to be measured on an ITO substrate and using an ionization potential measurement device (PYS-202, manufactured by Sumitomo Heavy Industries, Ltd.).

[0065] <Organic electroluminescence element> The organic electroluminescence device (organic EL device) of the present invention has a pair of electrodes and an organic layer disposed between the pair of electrodes and including at least a light-emitting layer, and at least one layer of the organic layer contains a compound represented by general formula (1). Here, the pair of electrodes is an anode and a cathode. For an explanation of the compound represented by general formula (1), please refer to the description in the above section <Compound represented by general formula (1)>. The compound represented by general formula (1) has excellent hole transporting ability and electron blocking ability, and is highly thermally stable in a thin film state. Therefore, by using this compound as a material for the organic layer, an organic EL device can be realized that exhibits high luminous efficiency, high power efficiency, and a long device life. The organic layer of the organic EL device of the present invention includes at least an emitting layer, and may include one or more organic layers in addition to the emitting layer. The compound represented by general formula (1) may be contained in the emitting layer or in an organic layer other than the emitting layer, but is preferably contained in an organic layer disposed between the emitting layer and the anode. Specific examples of organic layers disposed between the emitting layer and the anode include a hole injection layer, a hole transport layer, and an electron blocking layer. The compound represented by general formula (1) is preferably contained in the hole transport layer or the electron blocking layer, and more preferably in the electron blocking layer. In addition to the compound represented by general formula (1), known materials can be appropriately selected and used as materials for these organic layers.

[0066] In some embodiments of the present invention, the organic EL device has a laminated structure in which an anode, a hole injection layer, a hole transport layer, an electron blocking layer, an emitting layer, an electron transport layer, an electron injection layer, and a cathode are laminated in this order on a substrate, and at least the electron blocking layer contains a compound represented by general formula (1). A hole blocking layer may be provided between the emitting layer and the electron transport layer. Furthermore, in the organic EL device of the present invention, a single organic layer may serve two or more functions. Examples of such organic layers include a hole injection transport layer that serves both as a hole injection layer and a hole transport layer, and an electron injection transport layer that serves both as an electron injection layer and an electron transport layer. Furthermore, the organic EL device of the present invention may have a structure in which two or more organic layers having the same function are laminated. For example, a structure in which two hole transport layers are laminated, a structure in which two emitting layers are laminated, or a structure in which two electron transport layers are laminated may be used. The organic EL device of the present invention does not exclude embodiments in which other layers are present between the layers, as long as the organic EL device has at least an anode, a hole transport layer, a light-emitting layer, an electron transport layer, and a cathode in the above order. Each component and layer of the organic EL element will be described in detail below.

[0067] [anode] 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.

[0068] [Hole injection layer, hole transport layer] The hole injection layer is provided between the anode and the light-emitting layer, or between the anode and the hole transport layer, for example, to lower the injection barrier for holes supplied from the anode, thereby reducing the driving voltage and improving the luminance of light emitted. The hole transport layer is a layer having a function of transporting holes. The hole transport layer may be a hole injection transport layer that also functions as a hole injection layer. In the organic EL device of the present invention, the compound represented by general formula (1) can be used as a material for the hole transport layer or hole injection transport layer. Here, the hole transport layer or hole injection transport layer may be composed of the compound represented by general formula (1), or may be composed of a combination of the compound represented by general formula (1) with other hole transport materials or hole injection materials. The compound represented by general formula (1) has excellent hole injection / transport performance, thin film stability, and durability. Therefore, an organic EL device using a compound represented by general formula (1) as a hole injection material or hole transport material has improved hole transport efficiency to the light-emitting layer, which reduces the driving voltage, thereby improving the durability of the device and enabling high efficiency, low driving voltage, and long life characteristics to be obtained. The compound represented by general formula (1) used in the hole injection layer, hole transport layer, and hole injection / transport layer may be one or more types selected from the group of compounds represented by general formula (1). In the organic EL device of the present invention, the hole injection layer, the hole transport layer, and the hole injection transport layer may be made of a material other than the compound represented by general formula (1). In addition to the compound represented by general formula (1), materials that can be used for the hole injection layer include phthalocyanine compounds such as copper phthalocyanine, porphyrin compounds, starburst-type triphenylamine derivatives, arylamine compounds having two or more triphenylamine structures or carbazolyl structures in the molecule, each of which is linked by a single bond or a divalent group not containing a heteroatom, acceptor heterocyclic compounds such as hexacyanoazatriphenylene, and coating-type polymer materials.

[0069] In addition to the compounds represented by general formula (1), materials for the hole injection layer and hole transport layer include 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[(di-4-tolylamino)phenyl]cyclohexane (TAPC); and arylamine compounds containing two or more triphenylamine or carbazolyl units in the molecule, each connected by a single bond or a divalent group containing no heteroatoms. Coating-type polymer materials such as poly(3,4-ethylenedioxythiophene) (PEDOT) / poly(styrenesulfonate) (PSS) and polymer compounds containing benzidine derivatives such as TPD in their partial structures are also useful.

[0070] These materials may be formed as a single film made of one kind, or as a mixed film made of a mixture of two or more kinds. The hole injection layer, hole transport layer, and hole injection transport layer may have a single-layer structure of a single film or a mixed film, or a laminate structure of a plurality of single films, a laminate structure of a plurality of mixed films, or a laminate structure of one or more single films and one or more mixed films.

[0071] Furthermore, the hole injection layer or the hole transport layer may be formed by adding a P-type dopant, such as trisbromophenylaminehexachloroantimony or a radialene derivative described in European Patent No. 2684932, to the hole injection material or the hole transport material.

[0072] The absolute value of the HOMO energy level of the hole transport material is preferably greater than the absolute value (5.4 eV) of the HOMO level of common hole transport materials such as NPD and TPD (i.e., it has a deeper HOMO level), and is preferably smaller than the absolute value of the HOMO energy level of the electron blocking material described below. Having a deeper HOMO level provides better hole transport capability. On the other hand, if the absolute value of the HOMO energy level of the hole transport material is smaller than the absolute value of the HOMO level of the electron blocking material, the transport of holes to the light-emitting layer is hindered. Specifically, the absolute value of the HOMO energy level of the hole transport material is preferably 5.45 eV to 5.80 eV, more preferably 5.50 eV to 5.65 eV.

[0073] [Electron blocking layer] The electron blocking layer is disposed, for example, between the light-emitting layer and the hole-transporting layer, and has the function of suppressing the diffusion of electrons present in the light-emitting layer to the outside of the light-emitting layer (toward the hole-transporting layer). This can improve the probability of recombination of electrons and holes in the light-emitting layer. The electron blocking layer usually also has the function of transporting holes. The electron blocking layer may also function as an exciton blocking layer, suppressing the diffusion of excitons from the light-emitting layer. The material for the electron blocking layer may be a compound represented by general formula (1). Compounds represented by general formula (1) have excellent electron blocking capabilities, high electron tolerance, and are stable even in a thin film state. They also have the characteristic of confining excitons generated in the light-emitting layer. As a result, organic EL devices using compounds represented by general formula (1) as electron-blocking materials have high luminous efficiency due to an improved probability of hole-electron recombination and suppressed thermal deactivation. Furthermore, the driving voltage is reduced, improving current tolerance, and thereby improving maximum luminance. The compound represented by general formula (1) used in the electron-blocking layer may be one or more of the compounds represented by general formula (1). Furthermore, the compound represented by general formula (1) may be used in combination with other electron-blocking materials.

[0074] In addition to the material represented by general formula (1), other materials that can be used for the electron blocking layer include 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, which have an electron blocking effect. These materials may also function as hole transport materials.

[0075] These electron blocking materials may be formed as a single film made of one type, or as a mixed film made of a mixture of multiple types. The hole injection layer, hole transport layer, and hole injection / transport layer may have a single-layer structure of a single film or a mixed film, or a laminate structure of multiple single films, multiple mixed films, or one or more single films and one or more mixed films.

[0076] The absolute value of the HOMO energy level of the electron-blocking material is preferably greater than the absolute value of the HOMO energy level of the hole-transporting material (i.e., it has a deeper HOMO level). Specifically, the absolute value of the HOMO energy level of the electron-blocking material is preferably 5.55 eV to 5.90 eV, more preferably 5.60 eV to 5.80 eV. Furthermore, the absolute value of the HOMO energy level of the electron-blocking material is preferably 0.05 eV to 0.45 eV greater than the absolute value of the HOMO energy level of the hole-transporting material, more preferably 0.05 eV to 0.35 eV, and even more preferably 0.10 eV to 0.35 eV.

[0077] [Emitting layer] The light-emitting layer is a layer that emits light after generating excitons by recombination of holes and electrons injected from the anode and cathode, respectively. The light-emitting layer may be used alone as the light-emitting layer, but preferably contains a light-emitting material and a host material. The host material may be a compound represented by general formula (1). The compound represented by general formula (1) has excellent hole transport properties and a wide band gap. As a result, an organic EL device using the compound represented by general formula (1) as a host material has a reduced driving voltage and improved luminous efficiency. The compound represented by general formula (1) used as the host material may be one or more types selected from the group of compounds represented by general formula (1). Furthermore, the compound represented by general formula (1) may be used in combination with other host materials. In addition to the compound represented by general formula (1), host materials include anthracene derivatives, 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, and polydialkylfluorene derivatives. 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).

[0078] The light-emitting material may be any of a fluorescent material, a phosphorescent material, and a delayed fluorescent material. Examples of luminescent materials include metal complexes of quinolinol derivatives such as tris(8-quinolinolato)aluminum (Alq3), various metal complexes, anthracene derivatives, bisstyrylbenzene derivatives, pyrene derivatives, oxazole derivatives, polyparaphenylenevinylene derivatives, etc. Further examples include quinacridone, coumarin, rubrene, perylene and their derivatives, benzopyran derivatives, rhodamine derivatives, and aminostyryl derivatives.

[0079] Phosphorescent materials that can be used include metal complexes of iridium, platinum, etc. For example, green phosphorescent emitters such as tris(2-phenylpyridinato)iridium(III) (Ir(ppy)3) and bis[2-(4,6-difluorophenyl)pyridinato-C] 2 ,N](picolinato)iridium(III) (FIrpic), blue phosphorescent emitters such as bis(2,4-difluorophenylpyridinato)-tetrakis(1-pyrazolyl)borateiridium(III) (FIr6), and red phosphorescent emitters such as bis(2-benzo[b]thiophen-2-yl-pyridine)(acetylacetonato)iridium(III) (Btp2Ir(acac)).

[0080] The amount of the phosphorescent material doped into the host material is preferably in the range of 1 to 30% by weight based on the total amount of the light-emitting layer in order to avoid concentration quenching.

[0081] Examples of delayed fluorescent materials include triazine derivatives such as PIC-TRZ and CC2TA, phenoxazine derivatives such as PXZ-TRZ, and carbazolyldicyanobenzene derivatives (CDCB derivatives) such as 4CzIPN. Specific examples of delayed fluorescent materials can be found in Appl. Phys. Let., 98, 083302 (2011). [ka]

[0082] In the light-emitting layer, a compound represented by the following general formula (III-1) or (III-2) can be preferably used as the light-emitting material. [ka]

[0083] In the formula, Q1 to Q3 may be the same or different and represent a substituted or unsubstituted aromatic hydrocarbon ring having 6 to 50 carbon atoms or a substituted or unsubstituted aromatic heterocycle having 2 to 50 carbon atoms. Y1 to Y3 may be the same or different and represent N-R3, CR4R5, O, S, Se, or SiR6R7. R3 to R7 may be the same or different and represent a hydrogen atom, a deuterium atom, a halogen atom, a nitro group, a cyano group, a substituted or unsubstituted alkyl group of 1 to 30 carbon atoms, a substituted or unsubstituted cycloalkyl group of 3 to 30 carbon atoms, a substituted or unsubstituted alkenyl group of 2 to 30 carbon atoms, a substituted or unsubstituted cycloalkenyl group of 3 to 30 carbon atoms, a substituted or unsubstituted heterocycloalkyl group of 1 to 30 carbon atoms, a substituted or unsubstituted aromatic hydrocarbon group of 6 to 50 carbon atoms, a substituted or unsubstituted aromatic heterocyclic group of 2 to 50 carbon atoms, a substituted or unsubstituted alkyloxy group of 1 to 30 carbon atoms, a substituted or unsubstituted aryloxy group of 6 to 30 carbon atoms, a substituted or unsubstituted alkylthio group of 1 to 30 carbon atoms, a substituted or unsubstituted arylthio group of 5 to 30 carbon atoms, a substituted or unsubstituted amino group of 0 to 30 carbon atoms, or a substituted or unsubstituted silyl group of 3 to 30 carbon atoms. R3 to R7 may each be bonded to any of Q1 to Q3 via a single bond, N, O, P, or S, or may be condensed to form a ring, and R4 and R5, and R6 and R7 may each be bonded to each other to form a ring. When Y2 or Y3 is N-R3, at least one of R3 represents a group represented by the following general formula (IV-A) or a group represented by the following general formula (IV-B). [ka]

[0084] In general formula (IV-A), X represents O or S. R8 to R 15 may be the same or different, and are a single bond, a hydrogen atom, a deuterium atom, a halogen atom, a hydroxy group, a nitro group, a cyano group, a substituted or unsubstituted alkyl group having 1 to 30 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 30 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 30 carbon atoms, a substituted or unsubstituted cycloalkenyl group having 3 to 30 carbon atoms, a substituted or unsubstituted alkynyl group having 2 to 30 carbon atoms, a substituted or unsubstituted heterocycloalkyl group having 1 to 30 carbon atoms, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 50 carbon atoms, a substituted or unsubstituted aromatic heterocyclic group having 2 to 50 carbon atoms, a substituted or unsubstituted R8 to R9 represent an alkyloxy group having 6 to 30 carbon atoms, a substituted or unsubstituted aryloxy group having 6 to 30 carbon atoms, a substituted or unsubstituted alkylthio group having 1 to 30 carbon atoms, a substituted or unsubstituted arylthio group having 5 to 30 carbon atoms, a substituted or unsubstituted amino group having 0 to 30 carbon atoms, a substituted or unsubstituted silyl group having 3 to 30 carbon atoms, a substituted or unsubstituted germanium group having 0 to 30 carbon atoms, a substituted or unsubstituted boron group having 0 to 30 carbon atoms, a substituted or unsubstituted aluminum group having 0 to 30 carbon atoms, a substituted phosphoryl group having 0 to 30 carbon atoms, a substituted or unsubstituted seleno group having 0 to 30 carbon atoms, or a substituted or unsubstituted tellurium group having 0 to 30 carbon atoms. 15 Any one of R8 to R 15 may be bonded to adjacent groups via a single bond, N, O, or S, or may be condensed to form a ring.

[0085] In general formula (IV-B), R 16 represents a hydrogen atom, a deuterium atom, a substituted or unsubstituted alkyl group having 1 to 30 carbon atoms, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 50 carbon atoms, or a substituted or unsubstituted aromatic heterocyclic group having 2 to 50 carbon atoms. 17represents a hydrogen atom, a deuterium atom, a substituted or unsubstituted alkyl group having 1 to 30 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 30 carbon atoms, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 50 carbon atoms, or a substituted or unsubstituted aromatic heterocyclic group having 2 to 50 carbon atoms. 18 ~R 20 may be the same or different and represent a hydrogen atom, a deuterium atom, a halogen atom, a cyano group, a substituted or unsubstituted alkyl group having 1 to 30 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 30 carbon atoms, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 50 carbon atoms, a substituted or unsubstituted aromatic heterocyclic group having 2 to 50 carbon atoms, a substituted or unsubstituted alkyloxy group having 1 to 30 carbon atoms, a substituted or unsubstituted alkylthio group having 1 to 30 carbon atoms, a substituted or unsubstituted amino group having 0 to 30 carbon atoms, or a substituted or unsubstituted silyl group having 3 to 30 carbon atoms. The wavy line represents the bond to N. R 16 ~R 20 may be bonded to adjacent groups via a single bond, N, O, or S, or may be condensed to form a ring.

[0086] In general formulas (III-1) and (III-2), Q1 to Q3 are preferably benzene rings. The benzene rings of Q1 and Q2 also preferably have a benzofuro-fused ring structure or a benzothieno-fused ring structure. Substituents for the benzene rings of Q1 to Q3 are preferably deuterium atoms, alkyl groups having 1 to 30 carbon atoms, aromatic hydrocarbon groups having 6 to 50 carbon atoms, diarylamino groups having 12 to 30 carbon atoms, and groups combining two or more of these. In general formulas (III-1) and (III-2), Q2 is also preferably a furan ring fused with a benzene ring (i.e., a benzofuro structure) or a thiol ring fused with a benzene ring (i.e., a benzothieno structure). In general formulas (III-1) and (III-2), Y1 is preferably O or S. Y2 and Y3 are each preferably independently N-R3. R3 is preferably a substituted or unsubstituted phenyl group (the phenyl group may be fused with a ring). Preferred substituents include a deuterium atom, an alkyl group having 1 to 30 carbon atoms, an aromatic hydrocarbon group having 6 to 50 carbon atoms, a dibenzofuryl group, a dibenzothienyl group, and a group combining two or more of these. The benzene ring constituting the phenyl group may have a benzofuro-fused ring structure or a benzothieno-fused ring structure. It is also preferred that Y3 is O.

[0087] Preferred compounds of general formulas (III-1) and (III-2) include compounds represented by the following general formula (III-3), compounds represented by the following general formula (III-4), compounds represented by the following general formula (III-5), and compounds represented by the following general formula (III-6). [ka]

[0088] In the general formulae (III-3) to (III-6), Y1 to Y3 and R3 to R7 are defined as in the general formulae (III-1) and (III-2). Y4 represents N-R3, C-R4R5, O, S, Se, or Si-R6R7. Z may be the same or different and is N or CR. 21 Represents R 21represents a hydrogen atom, a deuterium atom, a halogen atom, a cyano group, a substituted or unsubstituted alkyl group having 1 to 30 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 30 carbon atoms, a substituted or unsubstituted aromatic heterocyclic group having 2 to 50 carbon atoms, a substituted or unsubstituted alkyloxy group having 1 to 30 carbon atoms, a substituted or unsubstituted aryloxy group having 6 to 30 carbon atoms, a substituted or unsubstituted alkylthio group having 1 to 30 carbon atoms, a substituted or unsubstituted arylthio group having 5 to 30 carbon atoms, a substituted or unsubstituted alkylamino group having 1 to 30 carbon atoms, a substituted or unsubstituted arylamino group having 5 to 30 carbon atoms, a substituted or unsubstituted alkylsilyl group having 1 to 30 carbon atoms, or a substituted or unsubstituted arylsilyl group having 5 to 30 carbon atoms. 21 may be bonded to adjacent groups via a single bond, N, O, or S, or may be condensed to form a ring. The definitions and details of terms such as groups in the explanation of general formulas (III-1) to (III-5) are the same as the definitions and explanations of the terms of the corresponding groups described in general formula (I).

[0089] The compound represented by general formula (I) can exert a more excellent effect when used in combination with a compound represented by general formula (III-1) or (III-2). Therefore, it is possible to provide an electron-blocking material composed of a compound represented by general formula (I) for use in combination with a compound represented by general formula (III-1) or (III-2); a laminate (preferably a light-emitting laminate) comprising a layer containing a compound represented by general formula (III-1) or (III-2) and a layer containing a compound represented by general formula (I); an organic EL device comprising a compound represented by general formula (III-1) or (III-2) and a compound represented by general formula (I); an organic EL device having a layer containing a compound represented by general formula (I) and a layer containing a compound represented by general formula (III-1) or (III-2) (these two layers are preferably adjacent); and an organic EL device having an electron-blocking layer containing a compound represented by general formula (I) and a light-emitting layer containing a compound represented by general formula (III-1) or (III-2) (these two layers are preferably adjacent).

[0090] Furthermore, by using it in combination with a compound represented by general formula (II), excellent effects can be exhibited. For this reason, electron-blocking materials consisting of a compound represented by general formula (I) for use in combination with both a compound represented by general formula (II) and a compound represented by general formula (III-1) or (III-2); laminates (preferably light-emitting laminates) consisting of a layer containing a compound represented by general formula (II), a layer containing a compound represented by general formula (III-1) or (III-2), and a layer containing a compound represented by general formula (I); organic EL devices containing a compound represented by general formula (II), a compound represented by general formula (III-1) or (III-2), and a compound represented by general formula (I); It is possible to provide an organic EL device having a layer containing a compound represented by general formula (II), a layer containing a compound represented by general formula (I), and a layer containing a compound represented by general formula (III-1) or (III-2) (preferably these three layers are laminated in order so as to be in contact with each other); and an organic EL device having a hole transport layer containing a compound represented by general formula (II), an electron blocking layer containing a compound represented by general formula (I), and an emitting layer containing a compound represented by general formula (III-1) or (III-2) (preferably these three layers are laminated in order so as to be in contact with each other).

[0091] Specific examples of the compound represented by (III-1) or (III-2) are given below, but the compounds represented by (III-1) or (III-2) that can be used in the present invention should not be construed as being limited by these specific examples. [ka] [ka] [ka]

[0092] [Hole blocking layer] The hole blocking layer is disposed, for example, between the light emitting layer and the electron transporting layer, and has the function of preventing holes present in the light emitting layer from diffusing outside the light emitting layer (towards the electron transporting layer). The hole-blocking layer of the organic EL device of the present invention may be made of a compound having hole-blocking properties, such as a phenanthroline derivative such as bathocuproine (BCP), a metal complex of a quinolinol derivative such as bis(2-methyl-8-quinolinolato)-4-(phenylphenolato)aluminum (BAlq), various rare earth complexes, an oxazole derivative, a triazole derivative, or a triazine derivative. These materials may also function as an electron-transporting material. These materials may be formed as a single film made of one type, or as a mixed film made of a mixture of multiple types. The hole-blocking layer may have a single-layer structure of a single film or a mixed film, or a laminate structure of multiple single films, multiple mixed films, or one or more single films and one or more mixed films.

[0093] [Electron transport layer, electron injection layer] The electron injection layer is provided between the cathode and the light-emitting layer, or between the cathode and the electron transport layer, for example, to lower the injection barrier for electrons supplied from the cathode, thereby reducing the driving voltage and improving the luminance of emitted light. The electron transport layer is a layer having a function of transporting electrons. The electron transport layer may also function as an electron injection layer.

[0094] Materials that can be used for the electron transport layer include metal complexes of quinolinol derivatives such as Alq3 and BAlq, various metal complexes, triazole derivatives, triazine derivatives, oxadiazole derivatives, pyridine derivatives, pyrimidine derivatives, benzimidazole derivatives, thiadiazole derivatives, anthracene derivatives, carbodiimide derivatives, quinoxaline derivatives, pyridoindole derivatives, phenanthroline derivatives, and silole derivatives. These materials may be formed as a single film made of one kind of material, or as a mixed film made of a mixture of two or more kinds of materials. The electron transport layer and the electron injection layer may have a single-layer structure of a single film or a mixed film, or a laminate structure of a plurality of single films, a laminate structure of a plurality of mixed films, or a laminate structure of one or more single films and one or more mixed films.

[0095] Materials that can be used for the electron injection layer include 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, and metals such as ytterbium (Yb), samarium (Sm), calcium (Ca), strontium (Sr), and cesium (Cs). The electron injection layer can be omitted by selecting the electron transport layer and the cathode appropriately.

[0096] Furthermore, the electron injection layer and the electron transport layer may be formed by adding a metal (N-type dopant) such as cesium to these electron injection materials and electron transport materials.

[0097] [cathode] The cathode may be made of a metal having a low work function, such as aluminum, or an alloy having an even lower work function, such as a magnesium-silver alloy, a magnesium-indium alloy, or an aluminum-magnesium alloy.

[0098] [Capping layer] The main role of the capping layer is to improve the light extraction efficiency by being provided on the outside of the semi-transparent electrode with a low refractive index, and to protect the element from the external environment. The capping layer of the organic EL device of the present invention can be formed using monoamine derivatives or diamine derivatives having a benzoazole structure such as a benzoxazolyl group or a benzothiazolyl group, or heterocyclic derivatives such as a pyrimidine ring, a triazine ring, or a benzoazole ring, or a carbazolyl derivative. These materials can be formed as a single layer formed by film formation alone, or as a mixed layer formed by mixing two or more materials. Furthermore, these materials can be formed as a laminated structure of layers formed by film formation alone, a laminated structure of layers formed by film formation in a mixture, or a laminated structure of layers formed by film formation alone and a mixture of multiple types of these materials. Each of the layers constituting the organic EL device can be formed by a known method such as vapor deposition, spin coating, or ink jet printing. In the organic EL device, the thickness of the capping layer is preferably in the range of 30 to 120 nm, and particularly preferably in the range of 40 to 80 nm.

[0099] While the present invention has been described above using an organic EL element with a top emission structure as an example, the organic EL element to which the present invention is applicable is not limited to this, and may also be an organic EL element with a bottom emission structure or an organic EL element with a dual emission structure that emits light from both the top and bottom. For descriptions of the components and layers constituting organic EL elements with a bottom emission structure and a dual emission structure, please refer to the description of the organic EL element above. However, it is preferable that the electrode in the direction in which light is extracted from the light-emitting element to the outside be transparent or semitransparent. That is, in a bottom emission structure, the electrode on the substrate side is preferably transparent or semitransparent, and in a dual emission structure, it is preferable that both electrodes are transparent or semitransparent.

[0100] The compound represented by general formula (1) suitably used in the organic EL device of the present invention is preferably used as a constituent material of the hole injection layer, hole transport layer, electron blocking layer or light emitting layer of the organic EL device, and more preferably used as a constituent material of the hole transport layer or electron blocking layer.

[0101] Therefore, the compound represented by general formula (1) of the present invention is useful as a material for a hole injection layer, a hole transport layer, an electron blocking layer, or an emitting layer of an organic EL device, and can improve the luminous efficiency, driving voltage, and durability of conventional organic EL devices.

[0102] <Electronic equipment> The electronic device of the present invention has a pair of electrodes and at least one organic layer disposed between the pair of electrodes, and at least one of the organic layers contains a compound represented by general formula (1). For an explanation of the compound represented by general formula (1), please refer to the description in the above section <Compound represented by general formula (1)>. Examples of electronic devices include display devices and light-emitting devices equipped with organic EL elements. Examples of display devices include display components such as organic EL panel modules, televisions, mobile phones, tablets, and personal computers. Examples of light-emitting devices include lighting fixtures and vehicle lamps. [Example]

[0103] The following synthesis examples and working examples will further illustrate the features of the present invention. The materials, processing details, processing procedures, etc. shown below can be appropriately changed as long as they do not deviate from the spirit of the present invention. Therefore, the scope of the present invention is not limited to the following working examples.

[0104] [Synthesis Example 1] Synthesis of Compound (1-2) A reaction vessel was charged with 3.0 g of N-([1,1'-biphenyl]-4-yl)-[1,1':4',1''-terphenyl]-4-amine, 2.9 g of 4-bromo-1,1':4',1'':2''-quaterphenyl, 1.1 g of sodium tert-butoxide, 34 mg of palladium acetate, 61 mg of tri-tert-butylphosphine, and 28 mL of toluene, and the mixture was refluxed for 4 hours. Toluene, 15 g of silica gel, and 5 g of activated clay were added, and the mixture was stirred at 90 °C for 1 hour and then filtered. The filtrate was evaporated to dryness. The resulting solid was recrystallized from toluene / acetone, and the resulting white powder was dried to obtain 4.0 g of the target compound (1-2) (yield: 75%).

[0105] The structure of the resulting compound (1-2) was identified using NMR. 1 The following 39 hydrogen signals were detected by H-NMR (CDCl3). δ(ppm)=7.64-7.67(6H), 7.60(2H), 7.57(2H), 7.53(4H), 7.42-7.49(10H), 7.36(1H), 7.33(1H), 7.18-7.25(13H).

[0106] [ka]

[0107] [Synthesis Example 2] Synthesis of Compound (1-6) A reaction vessel was charged with 28.0 g of 4,4,5,5-tetramethyl-2-(1,1':4',1''-terphenyl-2-yl)-1,3,2-dioxaborolane, 29.6 g of 4-bromo-4'-iodobiphenyl, 16.3 g of potassium carbonate, and 908 mg of tetrakistriphenylphosphinepalladium(0). The mixture was refluxed under a toluene (140 mL), ethanol (35 mL), and HO (28 mL) mixture for 16 hours with stirring. After cooling, the reaction mixture was added with methanol and filtered to obtain a crude product. The crude product was purified by adsorption using silica gel and then crystallized using a toluene / hexane mixture to obtain 28.3 g (78% yield) of 4-bromo-1,1':4',1'':2'',1':4''',1''''-quinquiphenyl (Intermediate 1) as a pale reddish-white powder.

[0108] [ka]

[0109] Next, 4.00 g of intermediate 1, 1.25 g of sodium t-butoxide, 24 mg of tris(dibenzylideneacetone)dipalladium(0), 175 mg of tri-tert-butylphosphine, and 40 mL of toluene were charged into a reaction vessel and stirred under reflux for 12 hours. After allowing the reaction solution to cool, n-hexane was added and the mixture was filtered to obtain a crude product. Toluene, 14 g of silica gel, and 14 g of activated clay were added to the crude product, and the mixture was stirred at 90°C for 1 hour and filtered. The filtrate was evaporated to dryness. The resulting solid was recrystallized from toluene / n-hexane, and the resulting white powder was dried to obtain 5.2 g of the target compound (1-6) (yield: 77%).

[0110] The structure of the resulting compound (1-6) was identified using NMR. 1 The following 43 hydrogen signals were detected by H-NMR (CDCl3). δ(ppm)=7.64-7.67(6H), 7.40-7.60(25H), 7.36(1H), 7.32(2H), 7.22-7.27(9H)

[0111] [ka]

[0112] [Synthesis Example 3] Synthesis of Compound (1-10) A reaction vessel was charged with 3.3 g of di([1,1'-biphenyl]-4-yl)amine, 4.0 g of 4"-chloro-2-(naphthalen-2-yl)-[1,1':4',1"-terphenyl], 2.0 g of sodium tert-butoxide, 190 mg of tris(dibenzylideneacetone)dipalladium(0), 165 mg of tri-tert-butylphosphine, and 40 mL of toluene, and the mixture was refluxed for 7 hours. After the reaction was completed, toluene, 18 g of silica gel, and 18 g of activated clay were added, followed by heating, stirring, and filtration. The filtrate was concentrated and purified by crystallization using a toluene / hexane mixed solvent. The resulting white powder was washed with methanol and dried to obtain 3.8 g of the target compound (1-10) (yield: 62%).

[0113] The structure of the resulting compound (1-10) was identified using NMR. 1 The following 37 hydrogen signals were detected by H-NMR (CDCl3). δ(ppm)=7.74-7.82(3H), 7.40-7.64(23H), 7.32(2H), 7.16-7.26(9H).

[0114] [ka]

[0115] [Synthesis Example 4] Synthesis of Compound (1-12) A reaction vessel was charged with 4.1 g of N-([1,1'-biphenyl]-4-yl)-N-([1,1':4',1''-terphenyl]-4-yl)-amine, 4.0 g of 4''-chloro-2-(naphthalen-2-yl)-[1,1':4',1''-terphenyl], 2.0 g of sodium tert-butoxide, 190 mg of tris(dibenzylideneacetone)dipalladium(0), 165 mg of tri-tert-butylphosphine, and 40 mL of toluene, and refluxed for 13 hours. After cooling, the reaction solution was added with hexane, stirred, and filtered to obtain a crude product. Toluene, 21 g of silica gel, and 21 g of activated clay were added to the crude product, and the mixture was heated, stirred, and filtered. The filtrate was concentrated and purified by crystallization using a toluene / hexane mixed solvent. The resulting white powder was washed with acetone and dried to obtain 4.8 g (yield: 63%) of the target compound (1-12).

[0116] The structure of the resulting compound (1-12) was identified using NMR. 1 The following 41 hydrogen signals were detected by H-NMR (CDCl3). δ(ppm)=7.81(1H), 7.78(2H), 7.67(5H), 7.40-7.66(20H), 7.36(1H), 7.32(1H), 7.16-7.26(11H).

[0117] [ka]

[0118] [Synthesis Example 5] Synthesis of Compound (1-85) A reaction vessel was charged with 4.0 g of N-(4-dibenzofuran-4-yl-phenyl)-N-([1,1'-biphenyl]-4-yl)amine, 3.8 g of 4'''-bromo-[1,1':2',1'':4'',1'''-quaterphenyl], 1.2 g of sodium tert-butoxide, 270 mg of tris(dibenzylideneacetone)dipalladium(0), 200 mg of tri-tert-butylphosphine, and 100 mL of toluene, and refluxed for 1 hour. After cooling, the reaction solution was added with 7 g of silica gel and 7 g of activated clay. The mixture was stirred for 30 minutes and then filtered. The filtrate was concentrated and purified by crystallization using a chlorobenzene / hexane mixed solvent. The resulting white powder was dried to afford 6.2 g of the target compound (1-85) (yield: 90%).

[0119] The structure of the obtained compound (1-85) was identified by NMR. 1 The following 37 hydrogen signals were detected by H-NMR (DMSO-d6). δ(ppm)=8.20(1H), 8.14(1H), 7.93(2H), 7.65-7.80(8H), 7.40-7.62(11H), 7.35(1H), 7.12-7.31(13H).

[0120] [ka]

[0121] [Synthesis Example 6] Synthesis of Compound (1-89) A reaction vessel was charged with 4.2 g of N-([1,1'-biphenyl]-4-yl)-N-([1,1':4',1''-terphenyl-2,3,5,6-d4]-4-yl)-amine, 4.0 g of 4'''-bromo-[1,1':2',1'':4'',1'''-quaterphenyl], 1.5 g of sodium tert-butoxide, 290 mg of tris(dibenzylideneacetone)dipalladium(0), 210 mg of tri-tert-butylphosphine, and 40 mL of toluene, and refluxed for 5 hours. After cooling, the reaction solution was added with 7 g of silica gel and 7 g of activated clay. The mixture was heated and stirred for 30 minutes and then filtered. The filtrate was concentrated, purified by crystallization with a toluene / hexane mixed solvent, washed with acetone, and dried to obtain 6.6 g of the target compound (1-89) (yield: 91%).

[0122] The structure of the resulting compound (1-89) was identified using NMR. 1 The following 35 hydrogen signals were detected by H-NMR (DMSO-d6). δ(ppm)=7.70-7.82(6H), 7.62-7.70(6H), 7.56(2H), 7.40-7.52(8H), 7.31-7.40(2H), 7.20-7.30(3H), 7.12-7.20(8H).

[0123] [ka]

[0124] [Synthesis Example 7] Synthesis of compound (1-91) A reaction vessel was charged with 4.0 g of N-([1,1'-biphenyl]-4-yl)-N-([1,1':4',1''-terphenyl]-4-yl)-amine, 4.0 g of 4'''-bromo-[1,1':2',1'':4'',1''''-quaterphenyl-2''',3''',5'',6'''-d4], 1.5 g of sodium tert-butoxide, 280 mg of tris(dibenzylideneacetone)dipalladium(0), 100 mg of tri-tert-butylphosphine, and 40 mL of toluene. The mixture was refluxed for 4 hours. After cooling, 7 g of silica gel and 7 g of activated clay were added. The mixture was heated and stirred for 30 minutes and then filtered. The filtrate was concentrated, purified by crystallization with a toluene / hexane mixed solvent, washed with acetone, and dried to obtain 7.0 g of the target compound (1-91) (yield: 99%).

[0125] The structure of the resulting compound (1-91) was identified using NMR. 1 The following 35 hydrogen signals were detected by H-NMR (DMSO-d6). δ(ppm)=7.69-7.80(8H), 7.63-7.69(4H), 7.55(2H), 7.40-7.52(8H), 7.30-7.40(2H), 7.21-7.29(3H), 7.12-7.20(8H).

[0126] [ka]

[0127] [Synthesis Example 8] Synthesis of compound (1-93) A reaction vessel was charged with 4.0 g of N-([1,1'-biphenyl]-4-yl)-N-([1,1':4',1''-terphenyl-2,3,5,6-d4]-4-yl)amine, 4.0 g of 4'''-bromo-[1,1':2',1'':4'',1'''-quaterphenyl-2''',3''',5'',6'''-d4], 1.4 g of sodium tert-butoxide, 270 mg of tris(dibenzylideneacetone)dipalladium(0), 100 mg of tri-tert-butylphosphine, and 40 mL of toluene, and refluxed for 2 hours. After cooling, the reaction solution was added with 7 g of silica gel and 7 g of activated clay. The mixture was heated and stirred for 30 minutes and then filtered. The obtained filtrate was concentrated and purified by crystallization using a toluene / hexane mixed solvent, and then washed with acetone and dried to obtain 6.6 g (yield: 93%) of the target compound (1-93).

[0128] The structure of the resulting compound (1-93) was identified using NMR. 1 The following 31 hydrogen signals were detected by H-NMR (DMSO-d6). δ(ppm)=7.69-7.80(6H), 7.63-7.69(4H), 7.55(2H), 7.40-7.52(8H), 7.30-7.40(2H), 7.21-7.29(3H), 7.12-7.20(6H).

[0129] [ka]

[0130] <Evaluation of the properties of the compound represented by general formula (1)> Glass transition temperature measurement The glass transition temperatures of the compounds synthesized in the synthesis examples and the comparative compound (EBM-1) were measured using a high-sensitivity differential scanning calorimeter (Rigaku, DSCvesta Thermo plus EV02 series). The results are summarized in Table 1.

[0131] [ka]

[0132] EBM-1 is a compound described in Patent Document 5.

[0133] [Table 1]

[0134] While the glass transition temperature of the comparative compound EBM-1 is 103°C, the compound represented by general formula (1) has a glass transition temperature of 110°C or higher, indicating that the thin film state is stable. Therefore, by using the compound represented by general formula (1) in an organic EL device, it is possible to fabricate a device with excellent thermal stability.

[0135] Measurement of HOMO levels The compounds synthesized in the synthesis examples and EBM-1 were each vacuum-deposited onto an ITO substrate to form thin films with a thickness of 100 nm. The absolute value of the HOMO level (corresponding to the work function) of each thin film was measured using an ionization potential measurement device (Sumitomo Heavy Industries, Ltd., PYS-202). The results are summarized in Table 2.

[0136] [Table 2]

[0137] As shown in Table 2, the compound represented by general formula (1) has a larger absolute value of 5.4 eV than the HOMO level of common hole transport materials such as NPD and TPD, and it was confirmed that the compound has good hole transport ability.

[0138] <Evaluation of organic EL> [Example 1] The layer structure of the organic EL device fabricated in this example is shown in Figure 1. In this example, a reflective ITO electrode was previously formed on a glass substrate 1 as a transparent anode 2, and the organic EL device was fabricated by sequentially depositing a hole injection layer 3, a hole transport layer 4, an electron blocking layer 5, an emitting layer 6, an electron transport layer 7, an electron injection layer 8, a cathode 9, and a capping layer 10 thereon.

[0139] Specifically, a glass substrate 1 on which a 50 nm thick ITO film, a 100 nm thick silver alloy reflective film, and a 5 nm thick ITO film were formed in this order was subjected to ultrasonic cleaning in isopropyl alcohol for 20 minutes, and then dried for 10 minutes on a hot plate heated to 250° C. After that, it was subjected to UV ozone treatment for 2 minutes, and then the glass substrate with ITO (transparent anode) was placed in a vacuum deposition machine and the pressure was reduced to 0.001 Pa or less. Subsequently, the compound (Acceptor-1) and the compound (BCFN) were deposited by binary vapor deposition to form a hole injection layer 3 having a thickness of 10 nm so as to cover the transparent anode 2. At this time, the deposition rate ratio of Acceptor-1:BCFN was 3:97. On this hole injection layer 3, a compound (BCFN) was vapor deposited to a thickness of 140 nm to form a hole transport layer 4. On this hole transport layer 4, the compound (1-2) was deposited to a thickness of 5 nm to form an electron blocking layer 5. A 20 nm thick light-emitting layer 6 was formed on the electron-blocking layer 5 by binary deposition of the compound (Dopant-1) and the compound (ADN). At this time, the deposition rate ratio was Dopant-1:ADN=2:98. On this light-emitting layer 6, a compound (ETM-1) and a compound (ETM-2) were binary-deposited to form an electron transport layer 7 having a thickness of 30 nm. At this time, the deposition rate ratio of ETM-1:ETM-2 was set to 50:50. On this electron transport layer 7, lithium fluoride was vapor deposited to a thickness of 1 nm to form an electron injection layer 8. On this electron injection layer 8, a cathode 9 was formed by vapor depositing a magnesium-silver alloy to a thickness of 12 nm. Finally, a compound (CPL-1) was deposited to a thickness of 60 nm to form a capping layer 10. An organic EL device was fabricated through the above steps.

[0140] [ka]

[0141] [Examples 2 to 8, Comparative Example 1] Organic EL devices were produced under the same conditions as in Example 1, except that the compounds shown in Table 3 below were used instead of the compound (1-2) used as the material for the electron-blocking layer 5 in Example 1.

[0142] For the organic EL devices fabricated in Examples 1 to 8 and Comparative Example 1, a direct current voltage was applied in the atmosphere at room temperature, and the device characteristics were measured. The results are summarized in Table 3. The device life was measured when the luminance at the start of light emission (initial luminance) reached 1000 cd / m 2 When driven at a constant current, the luminance was 950 cd / m 2 The time it took for the brightness to decay to 95% (corresponding to 95% of the initial brightness taken as 100%) was measured.

[0143] [Table 3]

[0144] As shown in Table 3, a current density of 10 mA / cm 2 The luminous efficiency when a current of 10.63 cd / A was passed through the organic EL element of Comparative Example 1 was 10.63 cd / A, while the organic EL elements of Examples 1 to 8 exhibited high efficiency of 10.72 to 11.18 cd / A. Furthermore, the power efficiency was also high, with the organic EL elements of Examples 1 to 8 exhibiting high efficiency of 9.39 to 9.65 lm / W, while the organic EL element of Comparative Example 1 exhibited 9.12 lm / W. Furthermore, the element lifetime (95% decay) was 365 to 450 hours, which was longer than the organic EL element of Comparative Example 1 at 363 hours.

[0145] As is clear from the above results, the use of a compound with high thermal stability and excellent electron blocking ability has made it possible to realize an organic EL element with higher luminous efficiency and longer life than conventional organic EL elements. [Industrial Applicability]

[0146] The compound of the present invention has excellent electron blocking and hole transporting capabilities, and is also highly thermally stable in a thin film state. Therefore, organic EL devices using the compound of the present invention can achieve high luminous efficiency and long device life, and can be used in applications such as display devices and lighting in home appliances. Therefore, the present invention has high industrial applicability. [Explanation of symbols]

[0147] 1. Glass substrate 2 transparent anode 3. Hole injection layer 4. Hole transport layer 5 Electron blocking layer 6. Light-emitting layer 7 Electron transport layer 8 Electron injection layer 9 Cathode 10 Capping Layer

Claims

1. A compound represented by the following general formula (1): 【Chemistry 1】 [In the general formula (1), Ar 1 and Ar ２ may be the same or different from each other, a substituted or unsubstituted aromatic hydrocarbon group, or represents a substituted or unsubstituted aromatic heterocyclic group, X １ represents a group represented by the following general formula (2): 【Chemistry 2】 [In general formula (2), Ar ３ teeth, a substituted or unsubstituted aromatic hydrocarbon group, or represents a substituted or unsubstituted aromatic heterocyclic group, R １ ~R ８ may be the same or different and represent a hydrogen atom or a deuterium atom, R ９ ~R １２ may be the same or different, and are a hydrogen atom, a deuterium atom, a fluorine atom, a chlorine atom, a cyano group, a nitro group, a substituted or unsubstituted linear or branched alkyl group having 1 to 6 carbon atoms; a substituted or unsubstituted cycloalkyl group having 5 to 10 carbon atoms, a substituted or unsubstituted linear or branched alkenyl group having 2 to 6 carbon atoms, a substituted or unsubstituted linear or branched alkyloxy group having 1 to 6 carbon atoms, a substituted or unsubstituted cycloalkyloxy group having 5 to 10 carbon atoms, or represents a substituted or unsubstituted aryloxy group having 6 to 30 carbon atoms, n represents an integer of 1 or 2, and when n is 2, there are a plurality of R ５ ~R ８ may be the same or different. provided that n is 1 and Ar １ and Ar ２ When both are unsubstituted biphenylyl groups, Ar ３ is a substituted or unsubstituted fused aromatic hydrocarbon group, or a substituted or unsubstituted aromatic heterocyclic group. * represents the bonding position to N in general formula (1).

2. In the above general formula (1), Ar １ and Ar ２ are each the same or different and are a substituted or unsubstituted phenyl group, a substituted or unsubstituted biphenylyl group, a substituted or unsubstituted terphenylyl group, a substituted or unsubstituted naphthyl group, a substituted or unsubstituted phenanthrenyl group, a substituted or unsubstituted carbazolyl group, a substituted or unsubstituted dibenzofuranyl group, a substituted or unsubstituted dibenzothienyl group, or a substituted or unsubstituted fluorenyl group.

3. In the above general formula (2), R ９ ~R １２ The compound of claim 1 , wherein each of the is an hydrogen atom or a deuterium atom, which may be the same or different.

4. In the above general formula (2), Ar ３ is a substituted or unsubstituted phenyl group, a substituted or unsubstituted biphenylyl group, a substituted or unsubstituted terphenylyl group, a substituted or unsubstituted naphthyl group, a substituted or unsubstituted phenanthrenyl group, a substituted or unsubstituted carbazolyl group, a substituted or unsubstituted dibenzofuranyl group, a substituted or unsubstituted dibenzothienyl group, or a substituted or unsubstituted fluorenyl group.

5. In the above general formula (2), Ar ３ The compound according to claim 4, wherein R is a substituted or unsubstituted phenyl group, a substituted or unsubstituted biphenylyl group, or a substituted or unsubstituted naphthyl group.

6. 10. An organic electroluminescence device having a pair of electrodes and at least one organic layer sandwiched between them, wherein the organic layer contains the compound according to claim 1.

7. 7. The organic electroluminescence device according to claim 6, wherein the organic layer is a hole transport layer.

8. 7. The organic electroluminescence device according to claim 6, wherein the organic layer is an electron blocking layer.

9. 7. The organic electroluminescence device according to claim 6, wherein the organic layer is a hole injection layer.

10. 10. An electronic device having a pair of electrodes and at least one organic layer sandwiched between them, wherein the organic layer contains the compound according to claim 1.

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