Arylamine compound, organic electroluminescent element, and electronic device

Abstract

The object of the present invention is to provide an organic compound having excellent properties such as excellent hole injection / transport performance, electron blocking ability, and high stability in a thin film state as a material for highly efficient and durable organic EL devices, and further to provide highly efficient and durable organic EL devices using this compound. The arylamine compound of the present invention has excellent heat resistance and good hole-transporting ability. Organic EL devices using the compound in the hole-transporting layer, electron-blocking layer, light-emitting layer, and hole-injecting layer of the organic EL device exhibited good device characteristics.

Description

[Technical Field]

[0001] The present invention relates to a compound and an element suitable for an organic electroluminescence element (hereinafter abbreviated as organic EL element), which is a self-luminous element suitable for various display devices, and more particularly to an arylamine compound and an organic EL element 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, making organic EL devices practical. They layered a phosphor capable of transporting electrons and an organic material capable of transporting holes, and injected both charges into the phosphor layer to emit light, achieving an luminance 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, resulting in high efficiency and durability being achieved by electroluminescent devices 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 can also be prepared by doping a charge-transporting compound, generally called a host material, with a fluorescent compound, a phosphorescent compound, or a material that emits delayed fluorescence. As described in the aforementioned non-patent document, the selection of organic materials in an organic EL device has a significant impact on various properties of the device, such as efficiency and durability (see, for example, non-patent document 2).

[0007] In organic EL devices, charges injected from both electrodes recombine in the light-emitting layer to emit light. However, the efficient transfer of both hole and electron charges to the light-emitting layer is crucial, making it necessary to achieve a device with excellent carrier balance. Therefore, by using a material that has the properties of enhancing hole injection properties, which supply holes injected from the anode to the light-emitting layer, and enhancing 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 confining excitons generated in the light-emitting layer, high luminous efficiency can be achieved. To achieve this, the role played by hole transport materials is important, and hole transport materials with high hole injection properties, high hole mobility, high electron blocking properties, and high durability against electrons are required.

[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, among the aromatic amine derivatives described in the above patent documents, the hole mobility is 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, preventing improvements in luminous efficiency. To achieve even higher efficiency, materials with better electron blocking properties, more stable thin films, and higher heat resistance have been required. Furthermore, although highly durable aromatic amine derivatives have been reported (see, for example, Patent Document 3), these have been 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] JP2009076817A1 [Patent Document 5] JP6674892B2 [Patent Document 6] European Patent No. 2684932 [Patent Document 7] KR101888249B1 [Patent Document 8] KR102259465B1 [Patent Document 9] KR102078171B1 [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] The object of the present invention is to provide a material for an organic EL device having the following characteristics in order to develop a highly efficient and durable organic EL device: (1) excellent hole injection and transport performance, (2) electron blocking ability, (3) high stability in a thin film state, and (4) excellent durability.

[0015] By using the material of the present invention, it is possible to provide an organic EL device that has (1) high luminous efficiency and power efficiency, (2) low light emission starting voltage and practical driving voltage, and (3) long life. [Means for solving the problem]

[0016] To achieve the above object, the inventors focused on the excellent hole injection / transport capabilities, thin film stability, and durability of arylamine compounds, and dramatically improved the material's properties by widening the band gap through the introduction of carbazolyl groups and by optimizing the introduction and substitution position of substituted naphthylene groups. In organic EL devices, the luminous efficiency and power efficiency have also improved, enabling the reduction of the light-emission onset voltage and practical driving voltage, and achieving a longer lifespan than conventional devices, leading to the completion of the present invention.

[0017] 1) That is, the present invention provides an arylamine compound represented by the following general formula (I):

[0018] [ka]

[0019] In the formula, A represents a substituted or unsubstituted aromatic hydrocarbon group, a substituted or unsubstituted aromatic heterocyclic group, or a substituted or unsubstituted fused polycyclic aromatic group; B represents a substituted or unsubstituted carbazolyl group; C represents an unsubstituted naphthylene group; R represents an unsubstituted aromatic hydrocarbon group, an unsubstituted aromatic heterocyclic group, or an unsubstituted fused polycyclic aromatic group; L1 to L3 each represent a single bond, an unsubstituted divalent aromatic hydrocarbon group, an unsubstituted divalent aromatic heterocyclic group, or an unsubstituted divalent condensed polycyclic aromatic group.

[0020] 2) The present invention also relates to the arylamine compound according to 1), wherein C in general formula (I) is an unsubstituted 1,2-naphthylene group, an unsubstituted 1,3-naphthylene group, an unsubstituted 2,4-naphthylene group, an unsubstituted 2,5-naphthylene group, an unsubstituted 2,6-naphthylene group, an unsubstituted 2,7-naphthylene group, or an unsubstituted 2,8-naphthylene group.

[0021] 3) The present invention also relates to the arylamine compound according to the above 2), wherein L2 and L3 in the general formula (I) are unsubstituted phenylene groups or unsubstituted biphenylylene groups.

[0022] 4) The present invention also relates to the arylamine compound according to 3) above, wherein R in general formula (I) is an unsubstituted phenyl group, an unsubstituted naphthyl group, an unsubstituted dibenzofuranyl group, an unsubstituted phenanthrenyl group, or an unsubstituted biphenyl group.

[0023] 5) The present invention also relates to the arylamine compound according to 4) above, wherein B in general formula (I) is a substituted or unsubstituted 9-carbazolyl group, a substituted or unsubstituted 2-carbazolyl group, or a substituted or unsubstituted 3-carbazolyl group.

[0024] 6) The present invention also relates to an arylamine compound according to the above 5), wherein B in the general formula (I) represents an unsubstituted 9-carbazolyl group.

[0025] 7) 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 arylamine compound described in 1) or 2) above.

[0026] 8) The present invention also provides the organic EL device according to the above 7), wherein the organic layer is a hole transport layer.

[0027] 9) The present invention also provides the organic EL device according to the above 7), wherein the organic layer is an electron blocking layer.

[0028] 10) The present invention also provides the organic EL device according to the above 7), wherein the organic layer is a hole injection layer.

[0029] 11) The present invention also provides the organic EL device according to the above 7), wherein the organic layer is a light-emitting layer.

[0030] 12) The present invention also provides an electronic device having a pair of electrodes and at least one organic layer sandwiched between them, wherein the organic layer contains the arylamine compound according to 1) or 2) above.

[0031] "A substituted or unsubstituted aromatic hydrocarbon group" represented by A in general formula (I), The "aromatic hydrocarbon group", "aromatic heterocyclic group", or "condensed polycyclic aromatic group" in the "substituted or unsubstituted aromatic heterocyclic group" or "substituted or unsubstituted condensed polycyclic aromatic group" includes: Specifically, a phenyl group, a biphenyl group, a terphenyl group, 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, a spirobifluorenyl group, 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, a carbazolyl group, a benzoxa Examples thereof include a zolyl group, a benzothiazolyl group, an azafluorenyl group, a diazafluorenyl group, an azaspirobifluorenyl group, a diazaspirobifluorenyl group, a quinoxalinyl group, a benzimidazolyl group, a pyrazolyl group, a dibenzofuranyl group, a dibenzothienyl group, a naphthyridinyl group, a phenanthrolinyl group, an acridinyl group, and a carbolinyl group, as well as an aryl group having 6 to 30 carbon atoms or a heteroaryl group having 2 to 20 carbon atoms.

[0032] The "substituent" in the "substituted aromatic hydrocarbon group", "substituted aromatic heterocyclic group", or "substituted fused polycyclic aromatic group" represented by A in general formula (I) includes: Specifically, deuterium atoms, cyano groups, nitro groups; halogen atoms such as fluorine atoms, chlorine atoms, bromine atoms, and iodine atoms; silyl groups such as trimethylsilyl groups and triphenylsilyl groups; linear or branched alkyl groups having 1 to 6 carbon atoms such as methyl groups, ethyl groups, and propyl groups; linear or branched alkyloxy groups having 1 to 6 carbon atoms such as methyloxy groups, ethyloxy groups, and propyloxy groups; alkenyl groups such as vinyl groups and allyl groups; aryloxy groups such as phenyloxy groups and tolyloxy groups; arylalkyloxy groups such as benzyloxy groups and phenethyloxy groups; phenyl groups, biphenyl groups, terphenyl groups, naphthyl groups, anthracene groups, Examples of the substituents include aromatic hydrocarbon groups or condensed polycyclic aromatic groups such as a pyridyl 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 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. These substituents may be further substituted with the substituents exemplified above. 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, an oxygen atom, or a sulfur atom to form a ring.

[0033] In the "substituted or unsubstituted carbazolyl group" represented by B in general formula (I), The "substituent" includes a "substituted aromatic hydrocarbon group" represented by A in general formula (I), Examples of the "substituent" in the "substituted aromatic heterocyclic group" or the "substituted fused polycyclic aromatic group" include the same ones as those exemplified above, and possible embodiments thereof are also the same.

[0034] Examples of the "aromatic hydrocarbon group," "aromatic heterocyclic group," or "fused polycyclic aromatic group" represented by R in general formula (I) include the same as those shown as the "aromatic hydrocarbon group," "aromatic heterocyclic group," or "fused polycyclic aromatic group" in the "substituted or unsubstituted aromatic hydrocarbon group," "substituted or unsubstituted aromatic heterocyclic group," or "substituted or unsubstituted fused polycyclic aromatic group" represented by A in general formula (I), and possible embodiments thereof are also similar.

[0035] Examples of the "divalent aromatic hydrocarbon group," "divalent aromatic heterocyclic group," or "divalent fused polycyclic aromatic group" represented by L1 to L3 in general formula (I) include groups in which one hydrogen atom has been removed from the group shown as the "aromatic hydrocarbon group," "aromatic heterocyclic group," or "fused polycyclic aromatic group" in the "substituted or unsubstituted aromatic hydrocarbon group," "substituted or unsubstituted aromatic heterocyclic group," or "substituted or unsubstituted fused polycyclic aromatic group" represented by A in general formula (I).

[0036] As L2 in the general formula (I), a biphenylene group is preferred, and a 2,4'-biphenylene group or a 3,4'-biphenylene group is more preferred.

[0037] As L3 in general formula (I), a phenylene group is preferred, and a 1,4-phenylene group is more preferred.

[0038] As R in the general formula (I), a phenyl group or a naphthyl group is more preferable.

[0039] As C in the general formula (I), a 1,3-naphthylene group, a 2,4-naphthylene group, a 2,5-naphthylene group or a 2,8-naphthylene group is more preferable.

[0040] The arylamine compound represented by the general formula (I) and 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 as a constituent material of the hole transport layer or electron blocking layer. [Effects of the Invention]

[0041] The arylamine compounds of the present invention have properties such as (1) better hole injection properties, (2) higher hole mobility, (3) superior electron blocking ability, (4) higher electron resistance, (5) stable existence in a thin film state, and (6) superior heat resistance, compared to conventional hole transport materials. By using the arylamine compounds of the present invention in organic EL devices, properties such as (7) higher luminous efficiency, (8) lower luminous initiation voltage, (9) lower practical driving voltage, and (10) longer life can be obtained.

[0042] The arylamine compound of the present invention has excellent electron blocking ability, high electron tolerance, and is stable even in a thin film state, and is characterized by its ability to confine excitons generated in the light-emitting layer. As a result, an organic EL device having an electron-blocking layer prepared using the compound as an electron-blocking material has high luminous efficiency due to an improved probability of hole-electron recombination and suppression of thermal deactivation, and also has improved maximum luminance due to a reduced driving voltage and improved current tolerance. [Brief explanation of the drawings]

[0043] [Figure 1] FIG. 1 shows compounds (1) to (12) as preferred specific examples of the arylamine compound represented by general formula (I). [Figure 2] FIG. 1 shows compounds (13) to (24) as preferred specific examples of the arylamine compound represented by general formula (I). [Figure 3] FIG. 1 shows compounds (25) to (36) as preferred specific examples of the arylamine compound represented by general formula (I). [Figure 4]FIG. 1 shows compounds (37) to (48) as preferred specific examples of the arylamine compound represented by general formula (I). [Figure 5] FIG. 1 shows compounds (49) to (60) as preferred specific examples of the arylamine compound represented by general formula (I). [Figure 6] FIG. 1 shows compounds (61) to (72) as preferred specific examples of the arylamine compound represented by general formula (I). [Figure 7] FIG. 1 shows compounds (73) to (84) as preferred specific examples of the arylamine compound represented by general formula (I). [Figure 8] FIG. 1 shows compounds (85) to (96) as preferred specific examples of the arylamine compound represented by general formula (I). [Figure 9] FIG. 1 shows compounds (97) to (108) as preferred specific examples of the arylamine compound represented by general formula (I). [Figure 10] FIG. 1 shows compounds (109) to (120) as preferred specific examples of the arylamine compound represented by general formula (I). [Figure 11] FIG. 1 shows compounds (121) to (135) as preferred specific examples of the arylamine compound represented by general formula (I). [Figure 12] FIG. 1 shows compounds (136) to (147) as preferred specific examples of the arylamine compound represented by general formula (I). [Figure 13] FIG. 1 shows compounds (148) to (161) as preferred specific examples of the arylamine compound represented by general formula (I). [Figure 14] FIG. 1 shows compounds (162) to (176) as preferred specific examples of the arylamine compound represented by general formula (I). [Figure 15] FIG. 1 shows compounds (177) to (188) as preferred specific examples of the arylamine compound represented by general formula (I). [Figure 16]FIG. 1 shows compounds (189) to (203) as preferred specific examples of the arylamine compound represented by general formula (I). [Figure 17] FIG. 1 shows compounds (204) to (215) as preferred specific examples of the arylamine compound represented by general formula (I). [Figure 18] FIG. 1 shows compounds (216) to (228) as preferred specific examples of the arylamine compound represented by general formula (I). [Figure 19] FIG. 1 shows compounds (229) to (239) as preferred specific examples of the arylamine compound represented by general formula (I). [Figure 20] FIG. 1 shows compounds (240) to (252) as preferred specific examples of the arylamine compound represented by general formula (I). [Figure 21] FIG. 1 shows compounds (253) to (261) as preferred specific examples of the arylamine compound represented by general formula (I). [Figure 22] FIG. 1 is a diagram showing the configurations of the organic EL devices of Examples 21 to 38 and Comparative Examples 1 to 3. DETAILED DESCRIPTION OF THE INVENTION

[0044] The arylamine compounds of the present invention are novel compounds, but these compounds can be synthesized according to known methods.

[0045] Among the arylamine compounds represented by the general formula (I) that can be suitably used in the organic EL device of the present invention, specific examples of preferred compounds are shown in Figures 1 to 21, but the present invention is not limited to these compounds.

[0046] The arylamine compound represented by general formula (I) can be purified by known methods such as column chromatography, adsorption purification using silica gel, activated carbon, activated clay, etc., recrystallization or crystallization using a solvent, or sublimation purification. The compound can be identified by NMR analysis. Physical properties include measurements of melting point, glass transition point (Tg), and work function. The melting point is an index of vapor deposition properties, the glass transition point (Tg) is an index of stability in the thin film state, and the work function is an index of hole injection properties, hole transport properties, or electron blocking properties.

[0047] The melting point and glass transition point (Tg) can be measured, for example, by a high-sensitivity differential scanning calorimeter (manufactured by Bruker AXS, DSC3100SA) using a powder.

[0048] The work function can be determined, for example, by forming a 100 nm thin film on an ITO substrate and measuring it with an ionization potential measuring device (PYS-202, manufactured by Sumitomo Heavy Industries, Ltd.).

[0049] The organic EL device of the present invention may have a structure comprising, in order on a substrate, an anode, a hole injection layer, a hole transport layer, an emitting layer, an electron transport layer, an electron injection layer, and a cathode; an electron blocking layer between the hole transport layer and the emitting layer; or a hole blocking layer between the emitting layer and the electron transport layer. In these multilayer structures, one organic layer may serve multiple functions. For example, one organic layer may serve both as a hole injection layer and a hole transport layer, or as an electron injection layer and an electron transport layer. Two or more organic layers having the same function may also be stacked, such as two stacked hole transport layers, two stacked emitting layers, or two stacked electron transport layers.

[0050] The anode of the organic EL device of the present invention is made of an electrode material with a large work function, such as ITO or gold. Materials for the hole injection layer of the organic EL device of the present invention include porphyrin compounds, such as copper phthalocyanine, starburst triphenylamine derivatives, arylamine compounds having two or more triphenylamine 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. These materials can be formed into thin films by known methods, such as vapor deposition, spin coating, and inkjet printing.

[0051] The arylamine compound of the present invention has excellent hole injection / transport properties, thin film stability, and durability. As a result, an organic EL device having a hole injection layer and / or hole transport layer prepared using the compound as a hole injection material and / or hole transport material has improved hole transport efficiency to the light-emitting layer, thereby improving luminous efficiency, and can also improve durability of the device by reducing the driving voltage, thereby achieving high efficiency, low driving voltage, and long life.

[0052] In addition to the arylamine compound of the present invention, materials for the hole injection layer and hole transport layer of the organic EL device of the present invention can 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 having two or more triphenylamine structures or carbazolyl structures in the molecule, each linked by a single bond or a divalent group containing no heteroatom. These materials can be used to form a film alone or in combination, and each can be used as a single layer. The layer may also be a laminate structure of layers formed from these materials alone, a laminate structure of layers formed from a mixture of these materials, or a laminate structure of layers formed from a mixture of these materials alone and layers formed from a mixture of multiple materials. Furthermore, a coating-type polymer material such as poly(3,4-ethylenedioxythiophene) (PEDOT) / poly(styrene sulfonate) (PSS) can be used as the material for the hole injection / transport layer. These materials can be formed into thin films by known methods such as vapor deposition, spin coating, and inkjet printing.

[0053] Furthermore, for the hole injection layer or the hole transport layer, materials that are normally used for these layers can be doped with P such as trisbromophenylaminehexachloroantimony or radialene derivatives (see, for example, Patent Document 6), or polymer compounds having a structure of a benzidine derivative such as TPD in their partial structure can be used.

[0054] The arylamine compound of the present invention has excellent electron blocking ability, high electron tolerance, and is stable even in a thin film state, and is characterized by its ability to confine excitons generated in the light-emitting layer. As a result, organic EL devices having an electron-blocking layer prepared using the compound as an electron-blocking material have high luminous efficiency due to an improved probability of hole-electron recombination and suppression of thermal deactivation, and also have improved maximum luminance due to a reduced driving voltage and improved current tolerance.

[0055] In addition to the arylamine compound of the present invention, other compounds with electron blocking properties can be used as materials for the electron-blocking layer of the organic EL device of the present invention, 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 materials may also serve as materials for the hole-transporting layer. These materials may be used alone or in combination to form a film, and multiple types may be used as a mixture, each of which may be used as a single layer. Furthermore, the laminated structure may be a laminated structure of layers formed from these materials alone, a laminated structure of layers formed from a mixture of these materials, or a laminated structure of layers formed from a mixture of these materials alone and a layer formed from a mixture of several kinds of these materials. These materials can be formed into thin films by known methods such as vapor deposition, spin coating, and inkjet printing.

[0056] The arylamine compound of the present invention has excellent hole-transporting properties and a wide band gap. As a result, an organic EL device having an emitting layer fabricated using the compound as a host material can have a reduced driving voltage and improved luminous efficiency by forming the emitting layer by supporting a fluorescent emitter, a phosphorescent emitter, or a delayed fluorescent emitter, which are called dopants.

[0057] In addition to the arylamine compound of the present invention, other materials that can be used for the light-emitting layer of the organic EL device of the present invention include metal complexes of quinolinol derivatives such as tris(8-quinolinolato)aluminum (Alq3), various metal complexes, anthracene derivatives, bisstyrylbenzene derivatives, pyrene derivatives, oxazole derivatives, and polyparaphenylenevinylene derivatives. The light-emitting layer may also be composed of a host material and a dopant material. Anthracene derivatives are preferred as the host material. In addition to the light-emitting materials, such as the arylamine compound of the present invention, 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 can also be used. Furthermore, dopant materials that can be used include quinacridone, coumarin, rubrene, perylene, and their derivatives, benzopyran derivatives, rhodamine derivatives, and aminostyryl derivatives. These materials may be used alone or in combination, and each may be used as a single layer. These materials may be used in a laminated structure consisting of layers formed from a single material, a laminated structure consisting of layers formed from a mixture of materials, or a laminated structure consisting of layers formed from a single material and a mixture of materials. These materials can be used to form thin films by known methods such as vapor deposition, spin coating, and inkjet printing.

[0058] Phosphorescent emitters can also be used as light-emitting materials. Examples of phosphorescent emitters include metal complexes of iridium, platinum, and the like. 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). In this case, examples of host materials include hole-injecting / transporting host materials such as carbazole derivatives such as 4,4'-di(N-carbazolyl)biphenyl (CBP), TCTA, and mCP, as well as the arylamine compounds of the present invention. Examples of electron-transporting host materials include p-bis(triphenylsilyl)benzene (UGH2) and 2,2',2''-(1,3,5-phenylene)-tris(1-phenyl-1H-benzimidazole) (TPBI). Using these materials allows for the fabrication of high-performance organic EL devices.

[0059] The phosphorescent light-emitting material is preferably doped into the host material by co-evaporation in a range of 1 to 30 weight percent based on the entire light-emitting layer to avoid concentration quenching.

[0060] Furthermore, materials that emit delayed fluorescence, such as CDCB derivatives such as PIC-TRZ, CC2TA, PXZ-TRZ, and 4CzIPN, can also be used as light-emitting materials (see, for example, Non-Patent Document 3). These materials can be formed into thin films by known methods such as vapor deposition, spin coating, and inkjet printing.

[0061] Materials for the hole-blocking layer of the organic EL device of the present invention include compounds with hole-blocking properties, such as phenanthroline derivatives such as bathocuproine (BCP), metal complexes of quinolinol derivatives such as bis(2-methyl-8-quinolinolato)-4-(phenylphenolato)aluminum (BAlq), various rare earth complexes, oxazole derivatives, triazole derivatives, and triazine derivatives. These materials may also serve as materials for the electron-transporting layer. These materials may be formed into films alone or in combination, and each may be used as a single layer. Furthermore, these materials may be used in a laminated structure consisting of layers formed alone or in a mixture, or in a laminated structure consisting of layers formed alone and layers formed in a mixture. These materials can be formed into thin films by known methods such as vapor deposition, spin coating, and inkjet printing.

[0062] Materials for the electron transport layer of the organic EL device of the present invention 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 can be used to form films alone or in combination, and each can be used as a single layer. Furthermore, these materials can be used in a laminated structure consisting of layers formed alone, layers formed in a mixture, or layers formed in a mixture of these materials alone and layers formed in a mixture. These materials can be used to form thin films using known methods such as vapor deposition, spin coating, and inkjet printing.

[0063] Materials that can be used for the electron injection layer of the organic EL device of the present invention 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.

[0064] Furthermore, for the electron injection layer and the electron transport layer, materials that are normally used for these layers and are doped with N-type metals such as cesium can be used.

[0065] For the cathode of the organic EL device of the present invention, 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 is used as the electrode material. [Example]

[0066] 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. [Example]

[0067] <Synthesis of compound (2)> A nitrogen-purged reaction vessel was charged with 9.5 g of N-{4-(3-phenylnaphthalen-1-yl)phenyl}-[1,1'-biphenyl]-4-amine, 9.0 g of 9-(4'-chloro-[1,1'-biphenyl]-2-yl)-carbazole, 3.1 g of sodium t-butoxide, 0.2 g of bis[tri(t-butylphosphine)]palladium(0), and 95 ml of toluene, and the mixture was stirred overnight under reflux. Silica gel was then added to the reaction mixture, which was stirred for 30 minutes. The mixture was then filtered through Celite at 90°C, and the solvent was removed by vacuum distillation. The resulting mixture was separated by column chromatography (carrier: silica gel, eluent: dichloromethane / n-heptane) to obtain 6.6 g of compound (2) (yield: 40.6%).

[0068] [ka]

[0069] The structure of the obtained white powder was identified using NMR. 1 The following 40 hydrogen signals were detected by H-NMR (CDCl3). δ(ppm)=8.07(2H), 8.05(1H), 7.97(2H), 7.77(2H), 7.73(1H), 7.71(1H), 7.62-7.54(5H ), 7.50(4H), 7.42(5H), 7.34(2H), 7.31(3H), 7.23(2H), 7.10(2H), 6.92(4H), 6.82(4H). [Example]

[0070] <Synthesis of compound (21)> A nitrogen-purged reaction vessel was charged with 10.0 g of N-phenyl-4-(1-phenylnaphthalen-3-yl)aniline, 10.5 g of 9-(4'-chloro-[1,1'-biphenyl]-2-yl)-carbazole, 3.9 g of t-butoxysodium, 0.4 g of t-butylphosphine (50 wt% toluene solution), 0.2 g of trisdibenzylideneacetonedipalladium(0), and 100 ml of xylene, and the mixture was stirred under reflux for 3 hours. Silica gel was then added to the reaction mixture, which was stirred for 30 minutes. The mixture was then filtered through Celite at 90°C, and the solvent was removed by vacuum distillation. The resulting mixture was separated by column chromatography (carrier: silica gel, eluent: dichloromethane / n-heptane) to obtain 14.0 g of compound (21) (yield: 75.5%).

[0071] [ka]

[0072] The structure of the obtained white powder was identified using NMR. 1 The following 36 hydrogen signals were detected by H-NMR (CDCl3). δ(ppm)=8.06(2H), 7.99(1H), 7.94(1H), 7.89(1H), 7.71(1H), 7.66(1H), 7.63-7.48(10H), 7.46(1H ), 7.40(1H), 7.30(2H), 7.23(2H), 7.16(2H), 7.08(2H), 6.96(1H), 6.85(2H), 6.80(4H), 6.68(2H). [Example]

[0073] <Synthesis of compound (22)> A nitrogen-purged reaction vessel was charged with 9.5 g of N-{4-(1-phenylnaphthalen-3-yl)phenyl}-[1,1'-biphenyl]-4-amine, 9.0 g of 9-(4'-chloro-[1,1'-biphenyl]-2-yl)-carbazole, 3.1 g of sodium t-butoxide, 0.2 g of bis[tri(t-butylphosphine)]palladium(0), and 95 ml of toluene, and the mixture was stirred overnight under reflux. Silica gel was then added to the reaction mixture, which was stirred for 30 minutes. The mixture was then filtered through Celite at 90°C, and the solvent was removed by vacuum distillation. The resulting mixture was separated by column chromatography (carrier: silica gel, eluent: dichloromethane / n-heptane) to obtain 6.4 g of compound (22) (yield: 39.5%).

[0074] [ka]

[0075] The structure of the obtained white powder was identified using NMR. 1 The following 40 hydrogen signals were detected by H-NMR (CDCl3). δ(ppm)=8.08(2H), 8.01(1H), 7.95(1H), 7.89(1H), 7.72(1H), 7.67(1H), 7.61(1H), 7.60-7.49(1 2H), 7.49-7.37(6H), 7.31(3H), 7.24(1H), 7.09(2H), 6.90(2H), 6.86(2H), 6.83(2H), 6.74(2H). [Example]

[0076] <Synthesis of compound (42)> A nitrogen-purged reaction vessel was charged with 7.0 g of N-phenyl-4-(1-phenylnaphthalen-3-yl)aniline, 8.0 g of 9-(4'-chloro-[1,1'-biphenyl]-3-yl)-carbazole, 3.6 g of t-butoxysodium, 0.2 g of bis[tri(t-butylphosphine)]palladium(0), and 150 ml of toluene, and the mixture was stirred overnight under reflux. Silica gel was then added to the reaction mixture, which was stirred for 30 minutes. The mixture was then filtered through Celite at 90°C, and the solvent was removed by distillation under reduced pressure. The resulting mixture was purified by crystallization using a dichloromethane / acetone mixed solvent to obtain 10.0 g of compound (42) (yield: 77.0%).

[0077] [ka]

[0078] The structure of the obtained white powder was identified using NMR. 1 The following 36 hydrogen signals were detected by H-NMR (CDCl3). δ(ppm)=8.15(2H), 8.03(1H), 7.93(1H), 7.89(1H), 7.79(1H), 7.69(1H), 7.65 (4H), 7.57-7.45(10H), 7.45-7.37(4H), 7.29(4H), 7.25-7.17(6H), 7.07(1H). [Example]

[0079] <Synthesis of compound (43)> A nitrogen-purged reaction vessel was charged with 9.0 g of N-{4-(1-phenylnaphthalen-3-yl)phenyl}-[1,1'-biphenyl]-4-amine, 8.5 g of 9-(4'-chloro-[1,1'-biphenyl]-3-yl)-carbazole, 2.9 g of sodium t-butoxide, 0.2 g of bis[tri(t-butylphosphine)]palladium(0), and 90 ml of toluene, and the mixture was heated under reflux and stirred overnight. Silica gel was then added to the reaction mixture, which was stirred for 30 minutes. The mixture was then filtered through Celite at 90°C, and the solvent was removed by vacuum distillation. The resulting mixture was separated by column chromatography (carrier: silica gel, eluent: dichloromethane / n-heptane) to obtain 3.0 g of compound (43) (yield: 19.4%).

[0080] [ka]

[0081] The structure of the obtained white powder was identified using NMR. 1 The following 40 hydrogen signals were detected by H-NMR (CDCl3). δ(ppm)=8.16(2H), 8.05(1H), 7.95(1H), 7.90(1H), 7.80(1H), 7.69(5H), 7.62-7.47(15H), 7.47-7.38(6H), 7.36-7.24(8H). [Example]

[0082] <Synthesis of compound (60)> A nitrogen-purged reaction vessel was charged with 9.5 g of N-([1,1'biphenyl]-4-yl)-4'-(carbazol-9-yl)-[1,1'biphenyl]-4-amine, 7.4 g of 3-(4-chlorophenyl)-1-phenyl-naphthalene, 3.8 g of sodium t-butoxide, 0.2 g of bis[tri(t-butylphosphine)]palladium(0), and 170 ml of toluene, and the mixture was stirred overnight under reflux. Silica gel was then added to the reaction mixture, which was stirred for 30 minutes. The mixture was then filtered through Celite at 90°C, and the solvent was removed by distillation under reduced pressure. The resulting mixture was purified by recrystallization using toluene to obtain 10.9 g of compound (60) (yield: 73.0%).

[0083] [ka]

[0084] The structure of the obtained white powder was identified using NMR. 1 The following 40 hydrogen signals were detected by H-NMR (CDCl3). δ(ppm)=8.16(2H), 8.07(1H), 7.96(1H), 7.91(1H), 7.82(2H), 7.73(2H), 7.70(1H), 7.62(6H), 7.56(4H), 7.54-7.39(11H), 7.31(9H). [Example]

[0085] <Synthesis of compound (30)> A nitrogen-purged reaction vessel was charged with 6.7 g of N-phenyl-4-(3-phenylnaphthalen-1-yl)aniline, 7.0 g of 9-(4'-chloro-[1,1'-biphenyl]-3-yl)-carbazole, 2.6 g of t-butoxysodium, 0.2 g of bis[tri(t-butylphosphine)]palladium(0), and 70 ml of toluene, and the mixture was stirred overnight under reflux. Silica gel was then added to the reaction mixture, which was stirred for 30 minutes. The mixture was then filtered through Celite at 90°C, and the solvent was removed by vacuum distillation. The resulting mixture was separated by column chromatography (carrier: silica gel, eluent: dichloromethane / n-heptane) to obtain 10.1 g of compound (30) (yield: 81.3%).

[0086] [ka]

[0087] The structure of the obtained white powder was identified using NMR. 1 The following 36 hydrogen signals were detected by H-NMR (CDCl3). δ(ppm)=8.19(2H), 8.08-8.04(2H), 7.99(1H), 7.83-7.67(6H), 7.61(2H), 7.57-7.27(22H), 7.13(1H). [Example]

[0088] <Synthesis of compound (31)> A nitrogen-purged reaction vessel was charged with 8.0 g of N-{4-(3-phenylnaphthalen-1-yl)phenyl}-[1,1'-biphenyl]-4-amine, 7.0 g of 9-(4'-chloro-[1,1'-biphenyl]-3-yl)-carbazole, 2.6 g of sodium t-butoxide, 0.2 g of bis[tri(t-butylphosphine)]palladium(0), and 80 ml of toluene, and the mixture was stirred overnight under reflux. Silica gel was then added to the reaction mixture, which was stirred for 30 minutes. The mixture was then filtered through Celite at 90°C, and the solvent was removed by vacuum distillation. The resulting mixture was separated by column chromatography (carrier: silica gel, eluent: dichloromethane / n-heptane) to obtain 2.7 g of compound (31) (yield: 19.7%).

[0089] [ka]

[0090] The structure of the obtained white powder was identified using NMR. 1 The following 40 hydrogen signals were detected by H-NMR (CDCl3). δ(ppm)=8.20(2H), 8.08-8.06(2H), 8.00(1H), 7.85-7.40(26H), 7.37-7.32(9H). [Example]

[0091] <Synthesis of compound (46)> A nitrogen-purged reaction vessel was charged with 8.0 g of N-{4-(4-phenylnaphthalen-2-yl)phenyl}-[1,1'-biphenyl]-2-amine, 7.6 g of 9-(4'-chloro-[1,1'-biphenyl]-3-yl)-carbazole, 3.4 g of sodium t-butoxide, 0.2 g of bis[tri(t-butylphosphine)]palladium(0), and 160 ml of toluene. The mixture was heated and stirred overnight under reflux. Silica gel was then added to the reaction mixture, which was stirred for 30 minutes. The mixture was then filtered through Celite at 90°C, and the solvent was removed by vacuum distillation. The resulting mixture was separated by column chromatography (carrier: silica gel, eluent: dichloromethane / n-heptane) to obtain 9.9 g of compound (46) (yield: 72.4%).

[0092] [ka]

[0093] The structure of the obtained white powder was identified using NMR. 1 The following 40 hydrogen signals were detected by H-NMR (CDCl3). δ(ppm)=8.19(2H), 8.00(1H), 7.95(1H), 7.90(1H), 7.74(1H), 7.67-7.64(3H), 7.58-7.31(22H), 7.22(2H), 7.17-7.11(3H), 7.01(4H). [Example]

[0094] <Synthesis of compound (85)> A nitrogen-purged reaction vessel was charged with 10.0 g of 3'-(carbazol-9-yl)-N-phenyl-[1,1'-biphenyl]-4-amine, 8.1 g of 2-(4-chlorophenyl)-6-phenyl-naphthalene, 3.5 g of sodium t-butoxide, 0.4 g of t-butylphosphine (50 wt% toluene solution), 0.5 g of trisdibenzylideneacetonedipalladium(0), and 100 ml of xylene, and the mixture was heated under reflux and stirred overnight. Silica gel was then added to the reaction mixture, which was stirred for 30 minutes. The mixture was then filtered through Celite at 90°C, and the solvent was removed by distillation under reduced pressure. The resulting mixture was purified by crystallization using a toluene / acetone mixed solvent to obtain 9.8 g of compound (85) (yield: 58.4%).

[0095] [ka]

[0096] The structure of the resulting pale yellow powder was identified using NMR. 1 The following 36 hydrogen signals were detected by H-NMR (CDCl3). δ(ppm)=8.20(2H), 8.08(2H), 7.98(2H), 7.82(2H), 7.79(1H), 7.77(2H), 7.74-7.66(4H) , 7.59(2H), 7.57-7.50(5H), 7.46(2H), 7.42(1H), 7.34(4H), 7.28-7.23(6H), 7.12(1H). [Example]

[0097] <Synthesis of compound (96)> A nitrogen-purged reaction vessel was charged with 10.0 g of N-{4-(2-phenylnaphthalen-7-yl)phenyl}-[1,1'-biphenyl]-4-amine, 8.7 g of 9-(4'-chloro-[1,1'-biphenyl]-2-yl)-carbazole, 3.2 g of sodium t-butoxide, 0.4 g of t-butylphosphine (50 wt% toluene solution), 0.4 g of trisdibenzylideneacetonedipalladium(0), and 100 ml of xylene. The mixture was heated and stirred overnight under reflux. Silica gel was then added to the reaction mixture, which was stirred for 30 minutes. The mixture was then filtered through Celite at 90°C and the solvent was removed by vacuum distillation. The resulting mixture was separated by column chromatography (carrier: silica gel, eluent: dichloromethane / n-heptane) to obtain compound (96): 7.9 g (yield: 46.2%).

[0098] [ka]

[0099] The structure of the resulting pale yellow powder was identified using NMR. 1 The following 40 hydrogen signals were detected by H-NMR (CDCl3). δ(ppm)=8.12(2H), 8.10(2H), 7.95(2H), 7.76(5H), 7.67-7.50(9H), 7.50-7.39(5H), 7.34(3H), 7.28(2H), 7.13(2H), 6.95(1H), 6.92(2H), 6.89(2H), 6.86(1H), 6.77(2H). [Example]

[0100] <Synthesis of compound (245)> A nitrogen-purged reaction vessel was charged with 10.0 g of N-phenyl-4-(4-phenylnaphthalen-1-yl)aniline, 9.5 g of 9-(4'-chloro-[1,1'-biphenyl]-3-yl)carbazole, 5.2 g of t-butoxysodium, 0.4 g of t-butylphosphine (50 wt% toluene solution), 0.5 g of trisdibenzylideneacetonedipalladium(0), and 100 ml of xylene, and the mixture was stirred overnight under reflux. Silica gel was then added to the reaction mixture, which was stirred for 30 minutes. The mixture was then filtered through Celite at 90°C, and the solvent was removed by vacuum distillation. The resulting mixture was separated by column chromatography (carrier: silica gel, eluent: dichloromethane / n-heptane) to obtain 8.5 g of compound (245) (yield: 45.8%).

[0101] [ka]

[0102] The structure of the resulting pale yellow powder was identified using NMR. 1 The following 36 hydrogen signals were detected by H-NMR (DMSO). δ(ppm)=8.27(2H), 8.01(1H), 7.89-7.84(3H), 7.80-7.74(3H), 7.60-7.45(16H), 7.41(2H), 7.32(2H), 7.23-7.14(7H). [Example]

[0103] <Synthesis of compound (247)> A nitrogen-purged reaction vessel was charged with 14.0 g of N-{4-(4-phenylnaphthalen-1-yl)phenyl}-dibenzofuran-3-amine, 11.8 g of 9-(4'-chloro-[1,1'-biphenyl]-3-yl)-carbazole, 3.5 g of t-butoxysodium, 0.5 g of t-butylphosphine (50 wt% toluene solution), 0.6 g of trisdibenzylideneacetonedipalladium(0), and 140 ml of xylene, and the mixture was heated under reflux and stirred overnight. Silica gel was then added to the reaction mixture, which was stirred for 30 minutes. The mixture was then filtered through Celite at 90°C, and the solvent was removed by vacuum distillation. The resulting mixture was purified by crystallization using a toluene / acetone mixed solvent to obtain 13.4 g of compound (247) (yield: 56.7%).

[0104] [ka]

[0105] The structure of the resulting pale yellow powder was identified using NMR. 1 The following 38 hydrogen signals were detected by H-NMR (DMSO). δ(ppm)=8.27(2H), 8.13-8.08(2H), 8.03(1H), 7.91-7.76(6H), 7.66(1H), 7.61-7.38(19H), 7.33-7.23(7H). [Example]

[0106] <Synthesis of compound (249)> A nitrogen-purged reaction vessel was charged with 10.0 g of N-phenyl-4-{4-(naphthalen-2-yl)naphthalen-1-yl}aniline, 9.2 g of 9-(4'-chloro-[1,1'-biphenyl]-3-yl)carbazole, 3.4 g of t-butoxysodium, 0.4 g of t-butylphosphine (50 wt% toluene solution), 0.4 g of trisdibenzylideneacetonedipalladium(0), and 100 ml of xylene, and the mixture was heated under reflux overnight. Silica gel was then added to the reaction mixture, which was stirred for 30 minutes. The mixture was then filtered through Celite at 90°C, and the solvent was removed by vacuum distillation. The resulting mixture was separated by column chromatography (carrier: silica gel, eluent: dichloromethane / n-heptane) to obtain compound (249), 7.3 g (yield: 41.6%).

[0107] [ka]

[0108] The structure of the obtained white powder was identified using NMR. 1 The following 38 hydrogen signals were detected by H-NMR (CDCl3). δ(ppm)=8.19(2H), 8.14(1H), 8.05-7.92(5H), 7.83(1H), 7.71(3H), 7.64-7.43(15H), 7.40-7.29(10H), 7.13(1H). [Example]

[0109] <Synthesis of compound (252)> A nitrogen-purged reaction vessel was charged with 9.0 g of N-phenyl-4-(1-phenylnaphthalen-5-yl)aniline, 9.0 g of 9-(4'-chloro-[1,1'-biphenyl]-3-yl)carbazole, 2.8 g of t-butoxysodium, 0.4 g of t-butylphosphine (50 wt% toluene solution), 0.4 g of trisdibenzylideneacetonedipalladium(0), and 90 ml of xylene, and the mixture was stirred overnight under reflux. Silica gel was then added to the reaction mixture, which was stirred for 30 minutes. The mixture was then filtered through Celite at 90°C, and the solvent was removed by distillation under reduced pressure. The resulting mixture was purified by recrystallization from toluene to yield 7.9 g of compound (252) (yield: 47.3%).

[0110] [ka]

[0111] The structure of the obtained white powder was identified using NMR. 1 The following 36 hydrogen signals were detected by H-NMR (CDCl3). δ(ppm)=8.20(2H), 8.06(1H), 7.92(1H), 7.84(1H), 7.73(1H), 7.69(1H), 7.62(2H), 7.58-7.43(16H), 7.40-7.28(10H), 7.13(1H). [Example]

[0112] <Synthesis of compound (256)> A nitrogen-purged reaction vessel was charged with 7.5 g of 3'-(carbazol-9-yl)-N-phenyl-[1,1'-biphenyl]-4-amine, 5.9 g of 7-(4-chlorophenyl)-1-phenyl-naphthalene, 3.5 g of sodium t-butoxide, 0.3 g of t-butylphosphine (50 wt% toluene solution), 0.3 g of trisdibenzylideneacetonedipalladium(0), and 75 ml of xylene, and the mixture was heated under reflux and stirred overnight. Silica gel was then added to the reaction mixture, which was stirred for 30 minutes. The mixture was then filtered through Celite at 90°C, and the solvent was removed by vacuum distillation. The resulting mixture was purified by recrystallization from toluene to yield 6.9 g of compound (256) (yield: 58.5%).

[0113] [ka]

[0114] The structure of the obtained white powder was identified using NMR. 1 The following 36 hydrogen signals were detected by H-NMR (CDCl3). δ(ppm)=8.19(2H), 8.11(1H), 7.99(1H), 7.89(1H), 7.80-7.76(2H), 7.72 -7.65(2H), 7.58-7.43(16H), 7.35-7.29(4H), 7.22-7.18(6H), 7.09(1H). [Example]

[0115] <Synthesis of compound (258)> A nitrogen-purged reaction vessel was charged with 7.8 g of N-phenyl-4-(1-phenylnaphthalen-6-yl)aniline, 8.2 g of 9-(4'-chloro-[1,1'-biphenyl]-3-yl)carbazole, 3.0 g of t-butoxysodium, 0.4 g of t-butylphosphine (50 wt% toluene solution), 0.4 g of trisdibenzylideneacetonedipalladium(0), and 80 ml of xylene, and the mixture was heated under reflux overnight. Silica gel was then added to the reaction mixture, which was stirred for 30 minutes. The mixture was then filtered through Celite at 90°C, and the solvent was removed by vacuum distillation. The resulting mixture was separated by column chromatography (carrier: silica gel, eluent: dichloromethane / n-heptane) to obtain 11.6 g of compound (258) (yield: 80.2%).

[0116] [ka]

[0117] The structure of the obtained white powder was identified using NMR. 1 The following 36 hydrogen signals were detected by H-NMR (DMSO). δ(ppm)=8.27(3H), 8.02(1H), 7.88-7.74(9H), 7.63-7.37(14H), 7.33-7.29(2H), 7.12-7.19(7H). [Example]

[0118] <Synthesis of compound (261)> A nitrogen-purged reaction vessel was charged with 7.5 g of N-([1,1'biphenyl]-4-yl)-2'-(carbazol-9-yl)-[1,1'biphenyl]-4-amine, 5.0 g of 1-(4-chlorophenyl)-7-phenyl-naphthalene, 3.0 g of sodium t-butoxide, 0.2 g of t-butylphosphine (50 wt% toluene solution), 0.3 g of trisdibenzylideneacetonedipalladium(0), and 170 ml of xylene, and the mixture was heated under reflux and stirred overnight. Silica gel was then added to the reaction mixture, which was stirred for 30 minutes. The mixture was then filtered through Celite at 90°C, and the solvent was removed by distillation under reduced pressure. The resulting mixture was purified by crystallization using a dichloromethane / acetone mixed solvent to obtain 5.5 g of compound (261) (yield: 46.8%).

[0119] [ka]

[0120] The structure of the obtained white powder was identified using NMR. 1 The following 40 hydrogen signals were detected by H-NMR (CDCl3). δ(ppm)=8.21(1H), 8.08(2H), 8.01(1H), 7.89(1H), 7.80-7.75(2H), 7.67 -7.31(21H), 7.24(2H), 7.12(2H), 6.95-6.92(4H), 6.88(2H), 6.81(2H). [Example]

[0121] The melting point and glass transition point of the arylamine compound represented by general formula (I) were measured using a high-sensitivity differential scanning calorimeter (DSC3100SA, manufactured by Bruker AXS). The results are shown in Table 1.

[0122] [Table 1]

[0123] The arylamine compounds represented by general formula (I) in Examples 1 to 18 have glass transition points of 100° C. or higher, which indicates that they are stable in the thin film state. [Example]

[0124] Using the arylamine compounds represented by general formula (I) of Examples 1 to 18, vapor-deposited films with a thickness of 100 nm were prepared on ITO substrates, and the work functions were measured using an ionization potential measuring device (PYS-202, manufactured by Sumitomo Heavy Industries, Ltd.). The results are shown in Table 2.

[0125] [Table 2]

[0126] The arylamine compounds represented by general formula (I) in Examples 1 to 18 exhibit a preferable energy level compared to the work function of 5.4 eV of common hole transport materials such as NPD and TPD, and are found to have good hole transport ability.

[0127] Therefore, the arylamine compound 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. [Example]

[0128] As shown in Figure 22, the organic EL device was fabricated by 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 in this order on a glass substrate 1 on which a reflective ITO electrode had previously been formed as a transparent anode 2.

[0129] 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 deposited in sequence was 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-coated glass substrate was placed in a vacuum deposition machine and the pressure was reduced to 0.001 Pa or less. Next, a hole injection layer 3 was formed covering the transparent anode 2 by binary deposition of an electron acceptor (Acceptor-1) of the following structural formula and a compound (HTM-1) of the following structural formula at a deposition rate ratio of Acceptor-1:Compound (HTM-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 of a compound (HTM-1) of the following structural formula to a thickness of 140 nm. On this hole-transporting layer 4, an electron-blocking layer 5 was formed using the compound (2) of Example 1 to a thickness of 5 nm. On this electron-blocking layer 5, an emitting layer 6 was formed using a compound (EMD-1) having the following structural formula and a compound (EMH-1) having the following structural formula by binary deposition at a deposition rate ratio of EMD-1:EMH-1 = 5:95 to a thickness of 20 nm. On this emitting layer 6, an electron-transporting layer 7 was formed using a compound (ETM-1) having the following structural formula and a compound (ETM-2) having the following structural formula by binary deposition at a deposition rate ratio of ETM-1:ETM-2 = 50:50 to a thickness of 30 nm. On this electron-transporting layer 7, an electron-injecting layer 8 was formed using lithium fluoride to a thickness of 1 nm. On this electron-injecting layer 8, a cathode 9 was formed using a magnesium-silver alloy to a thickness of 12 nm. Finally, a capping layer 10 was formed using a compound (CPL-1) having the following structural formula by binary deposition at a thickness of 60 nm. The characteristics of the fabricated organic EL device were measured in air at room temperature. The results of measuring the light-emitting characteristics when a DC voltage was applied to the fabricated organic EL device are summarized in Table 3.

[0130] [ka] [Example]

[0131] An organic EL device was fabricated under the same conditions as in Example 21, except that compound (21) of Example 2 was used instead of compound (2) of Example 1 as the material for the electron-blocking layer 5. The characteristics of the fabricated organic EL device were measured in the atmosphere at room temperature. The measurement results of the light-emitting characteristics when a DC voltage was applied to the fabricated organic EL device are summarized in Table 3. [Example]

[0132] An organic EL device was fabricated under the same conditions as in Example 21, except that compound (22) of Example 3 was used instead of compound (2) of Example 1 as the material for the electron-blocking layer 5. The characteristics of the fabricated organic EL device were measured in the atmosphere at room temperature. The measurement results of the light-emitting characteristics when a DC voltage was applied to the fabricated organic EL device are summarized in Table 3. [Example]

[0133] An organic EL device was fabricated under the same conditions as in Example 21, except that compound (42) of Example 4 was used instead of compound (2) of Example 1 as the material for the electron-blocking layer 5. The characteristics of the fabricated organic EL device were measured in the atmosphere at room temperature. The measurement results of the light-emitting characteristics when a DC voltage was applied to the fabricated organic EL device are summarized in Table 3. [Example]

[0134] An organic EL device was fabricated under the same conditions as in Example 21, except that compound (43) of Example 5 was used instead of compound (2) of Example 1 as the material for the electron-blocking layer 5. The characteristics of the fabricated organic EL device were measured in the atmosphere at room temperature. The measurement results of the light-emitting characteristics when a DC voltage was applied to the fabricated organic EL device are summarized in Table 3. [Example]

[0135] An organic EL device was fabricated under the same conditions as in Example 21, except that compound (60) of Example 6 was used instead of compound (2) of Example 1 as the material for the electron-blocking layer 5. The characteristics of the fabricated organic EL device were measured in the atmosphere at room temperature. The measurement results of the luminescence characteristics when a DC voltage was applied to the fabricated organic EL device are summarized in Table 3. [Example]

[0136] An organic EL device was fabricated under the same conditions as in Example 21, except that compound (30) of Example 7 was used instead of compound (2) of Example 1 as the material for the electron-blocking layer 5. The characteristics of the fabricated organic EL device were measured in the atmosphere at room temperature. The measurement results of the light-emitting characteristics when a DC voltage was applied to the fabricated organic EL device are summarized in Table 3. [Example]

[0137] An organic EL device was fabricated under the same conditions as in Example 21, except that compound (31) of Example 8 was used instead of compound (2) of Example 1 as the material for the electron-blocking layer 5. The characteristics of the fabricated organic EL device were measured in the atmosphere at room temperature. The measurement results of the light-emitting characteristics when a DC voltage was applied to the fabricated organic EL device are summarized in Table 3. [Example]

[0138] An organic EL device was fabricated under the same conditions as in Example 21, except that compound (46) of Example 9 was used instead of compound (2) of Example 1 as the material for the electron-blocking layer 5. The characteristics of the fabricated organic EL device were measured in the atmosphere at room temperature. The measurement results of the luminescence characteristics when a DC voltage was applied to the fabricated organic EL device are summarized in Table 3. [Example]

[0139] An organic EL device was fabricated under the same conditions as in Example 21, except that compound (85) of Example 10 was used instead of compound (2) of Example 1 as the material for the electron-blocking layer 5. The characteristics of the fabricated organic EL device were measured in the atmosphere at room temperature. The measurement results of the luminescence characteristics when a DC voltage was applied to the fabricated organic EL device are summarized in Table 3. [Example]

[0140] An organic EL device was fabricated under the same conditions as in Example 21, except that compound (96) of Example 11 was used instead of compound (2) of Example 1 as the material for the electron-blocking layer 5. The characteristics of the fabricated organic EL device were measured in the atmosphere at room temperature. The measurement results of the luminescence characteristics when a DC voltage was applied to the fabricated organic EL device are summarized in Table 3. [Example]

[0141] An organic EL device was fabricated under the same conditions as in Example 21, except that compound (245) of Example 12 was used instead of compound (2) of Example 1 as the material for the electron-blocking layer 5. The characteristics of the fabricated organic EL device were measured in the atmosphere at room temperature. The measurement results of the light-emitting characteristics when a DC voltage was applied to the fabricated organic EL device are summarized in Table 3. [Example]

[0142] An organic EL device was fabricated under the same conditions as in Example 21, except that compound (247) of Example 13 was used instead of compound (2) of Example 1 as the material for the electron-blocking layer 5. The characteristics of the fabricated organic EL device were measured in the atmosphere at room temperature. The measurement results of the light-emitting characteristics when a DC voltage was applied to the fabricated organic EL device are summarized in Table 3. [Example]

[0143] An organic EL device was fabricated under the same conditions as in Example 21, except that compound (249) of Example 14 was used instead of compound (2) of Example 1 as the material for the electron-blocking layer 5. The characteristics of the fabricated organic EL device were measured in the atmosphere at room temperature. The measurement results of the luminescence characteristics when a DC voltage was applied to the fabricated organic EL device are summarized in Table 3. [Example]

[0144] An organic EL device was fabricated under the same conditions as in Example 21, except that compound (252) of Example 15 was used instead of compound (2) of Example 1 as the material for the electron-blocking layer 5. The characteristics of the fabricated organic EL device were measured in the atmosphere at room temperature. The measurement results of the light-emitting characteristics when a DC voltage was applied to the fabricated organic EL device are summarized in Table 3. [Example]

[0145] An organic EL device was fabricated under the same conditions as in Example 21, except that compound (256) of Example 16 was used instead of compound (2) of Example 1 as the material for the electron-blocking layer 5. The characteristics of the fabricated organic EL device were measured in the atmosphere at room temperature. The measurement results of the light-emitting characteristics when a DC voltage was applied to the fabricated organic EL device are summarized in Table 3. [Example]

[0146] An organic EL device was fabricated under the same conditions as in Example 21, except that compound (258) of Example 17 was used instead of compound (2) of Example 1 as the material for the electron-blocking layer 5. The characteristics of the fabricated organic EL device were measured in the atmosphere at room temperature. The measurement results of the light-emitting characteristics when a DC voltage was applied to the fabricated organic EL device are summarized in Table 3. [Example]

[0147] An organic EL device was fabricated under the same conditions as in Example 21, except that compound (261) of Example 18 was used instead of compound (2) of Example 1 as the material for the electron-blocking layer 5. The characteristics of the fabricated organic EL device were measured in the atmosphere at room temperature. The measurement results of the light-emitting characteristics when a DC voltage was applied to the fabricated organic EL device are summarized in Table 3.

[0148] [Comparative Example 1] For comparison, an organic EL device was fabricated under the same conditions as in Example 21 (see Patent Document 7), except that a compound (HTM-2) having the following structural formula was used as the material for the electron-blocking layer 5 instead of the compound (2) in Example 1. The characteristics of the fabricated organic EL device were measured in the atmosphere at room temperature. The measurement results of the light-emitting characteristics when a DC voltage was applied to the fabricated organic EL device are summarized in Table 3.

[0149] [ka]

[0150] Comparative Example 2 For comparison, an organic EL device was fabricated under the same conditions as in Example 21 (see Patent Document 8), except that a compound (HTM-3) having the following structural formula was used as the material for the electron-blocking layer 5 instead of the compound (2) in Example 1. The characteristics of the fabricated organic EL device were measured in the atmosphere at room temperature. The measurement results of the light-emitting characteristics when a DC voltage was applied to the fabricated organic EL device are summarized in Table 3.

[0151] [ka]

[0152] Comparative Example 3 For comparison, an organic EL device was fabricated under the same conditions as in Example 21 (see Patent Document 9), except that a compound (HTM-4) having the following structural formula was used as the material for the electron-blocking layer 5 instead of the compound (2) in Example 1. The characteristics of the fabricated organic EL device were measured in the atmosphere at room temperature. The measurement results of the light-emitting characteristics when a DC voltage was applied to the fabricated organic EL device are summarized in Table 3.

[0153] [ka]

[0154] The device life was measured using the organic EL devices fabricated in Examples 21 to 38 and Comparative Examples 1 to 3, and the results are summarized in Table 3. The device life was measured when the luminance at the start of light emission (initial luminance) was 2000 cd / m 2 When driven at a constant current, the luminance was 1900 cd / m 2 The time it took for the brightness to decay to 95% (corresponding to 95% of the initial brightness of 100%) was measured.

[0155] [Table 3]

[0156] As shown in Table 3, the current density was 10 mA / cm 2 The luminous efficiency when a current of 100 kJ / s was passed was 8.84 to 9.11 cd / A for the organic EL elements of Comparative Examples 1 to 3, while it was 9.82 to 10.42 cd / A for the organic EL elements of Examples 21 to 38, which was a high efficiency. Furthermore, the power efficiency was also high, being 9.39 to 10.08 lm / W for the organic EL elements of Examples 21 to 38, while it was 8.45 to 8.68 lm / W for the organic EL elements of Comparative Examples 1 to 3. Furthermore, it can be seen that the element lifetime (95% decay) was 422 to 714 hours for the organic EL elements of Examples 21 to 38, which was longer than the organic EL elements of Comparative Examples 1 to 3, which was 247 to 328 hours.

[0157] As is clear from the above results, the arylamine compound having a specific structure represented by general formula (I) according to the present invention has a higher hole mobility and an excellent electron blocking ability than the arylamine compounds used as conventional hole transport materials. Therefore, it has been found that an organic EL device using the blue light-emitting layer of the present invention together with the arylamine compound has a higher luminous efficiency and a longer lifetime than conventional organic EL devices. [Industrial Applicability]

[0158] The organic EL device using the arylamine compound having a specific structure of the present invention can improve the luminous efficiency and durability of the organic EL device, making it possible to develop applications such as home appliances and lighting. Furthermore, the arylamine compound of the present invention can be used not only in organic EL devices but also in electronic device fields such as electrophotographic photoreceptors, image sensors, photoelectric conversion elements, and solar cells.

[0159] 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. An arylamine compound represented by the following general formula (I): 【Chemical 1】 (In the formula, A represents a substituted or unsubstituted aromatic hydrocarbon group, a substituted or unsubstituted aromatic heterocyclic group, or a substituted or unsubstituted fused polycyclic aromatic group, B represents a substituted or unsubstituted carbazolyl group; C represents an unsubstituted naphthylene group; R represents an unsubstituted aromatic hydrocarbon group, an unsubstituted aromatic heterocyclic group, or an unsubstituted fused polycyclic aromatic group; L １ ~L ３ represents a single bond, an unsubstituted divalent aromatic hydrocarbon group, an unsubstituted divalent aromatic heterocyclic group, or an unsubstituted divalent fused polycyclic aromatic group.

2. 2. The arylamine compound according to claim 1, wherein C in general formula (I) represents an unsubstituted 1,2-naphthylene group, an unsubstituted 1,3-naphthylene group, an unsubstituted 2,4-naphthylene group, an unsubstituted 2,5-naphthylene group, an unsubstituted 2,6-naphthylene group, an unsubstituted 2,8-naphthylene group, or an unsubstituted 2,7-naphthylene group.

3. L in the general formula (I) ２ and L ３ 3. The arylamine compound according to claim 2, wherein is an unsubstituted phenylene group or an unsubstituted biphenylylene group.

4. 4. The arylamine compound according to claim 3, wherein R in the general formula (I) is an unsubstituted phenyl group, an unsubstituted naphthyl group, an unsubstituted dibenzofuranyl group, an unsubstituted phenanthrenyl group, or an unsubstituted biphenyl group.

5. 5. The arylamine compound according to claim 4, wherein B in the general formula (I) represents a substituted or unsubstituted 9-carbazolyl group, a substituted or unsubstituted 2-carbazolyl group, or a substituted or unsubstituted 3-carbazolyl group.

6. 6. The arylamine compound according to claim 5, wherein B in the general formula (I) represents an unsubstituted 9-carbazolyl group.

7. 3. An organic EL device comprising a pair of electrodes and at least one organic layer sandwiched between them, wherein the organic layer contains the arylamine compound according to claim 1.

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

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

10. 8. The organic EL device according to claim 7, wherein the organic layer is a hole injection layer.

11. 8. The organic EL device according to claim 7, wherein the organic layer is a light-emitting layer.

12. 3. An electronic device having a pair of electrodes and at least one organic layer sandwiched between them, wherein the organic layer contains the arylamine compound according to claim 1 or 2.

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