Aryl amine compound, organic electroluminescence element, and electronic device

Abstract

To provide: a material for organic EL elements which is excellent in hole transport ability and electron-blocking ability, and which also has high thermal stability in a thin film state; and an organic EL element having a low driving voltage, high luminous efficiency and power efficiency, and a long device lifetime.SOLUTION: The invention provides an aryl amine compound represented by the general formula (1) in the figure.SELECTED DRAWING: None

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] 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).

[0006] 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.

[0007] 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.

[0008] 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).

[0009] In addition, among the aromatic amine derivatives described in the above patent documents, the hole mobility is 10 -3 cm 2Although 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.

[0010] In order to solve this problem, arylamine compounds having a substituted carbazole structure or a triarylbenzene structure 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]

[0011] [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] U.S. Patent No. 8,021,764 [Patent Document 5] Patent No. 7177966 [Patent Document 6] European Patent No. 2684932 [Non-patent literature]

[0012] [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]

[0013] 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]

[0014] The present inventors have conducted extensive research to achieve the above-mentioned object and have found that an arylamine compound having a phenyl group bearing an aromatic hydrocarbon group at the 3-, 4-, and 5-positions has excellent hole transporting ability and electron blocking ability, and also has high thermal stability in a thin film state. They have also found that the use of this arylamine compound enables the realization of an organic EL device with low driving voltage, high luminous efficiency, high power efficiency, and long life. The present invention has been proposed based on these findings and specifically has the following configuration.

[0015] 1) An arylamine compound represented by the following general formula (1):

[0016] [ka] (In the formula, Ar1 and Ar2 may be the same or different and each represent a substituted or unsubstituted aromatic hydrocarbon group or a substituted or unsubstituted aromatic heterocyclic group, L represents a divalent group of a substituted or unsubstituted aromatic hydrocarbon group or a divalent group of a substituted or unsubstituted aromatic heterocyclic group; R1~R 17 represent, each of which may be the same or different, a hydrogen atom, a deuterium atom, a fluorine atom, a chlorine atom, a cyano group, a nitro group, an optionally substituted linear or branched alkyl group of 1 to 6 carbon atoms, an optionally substituted cycloalkyl group of 5 to 10 carbon atoms, an optionally substituted linear or branched alkenyl group of 2 to 6 carbon atoms, an optionally substituted linear or branched alkyloxy group of 1 to 6 carbon atoms, an optionally substituted cycloalkyloxy group of 5 to 10 carbon atoms, a substituted or unsubstituted aryloxy group, an optionally substituted aromatic hydrocarbon group of 5 to 12 carbon atoms, or an optionally substituted aromatic heterocyclic group of 4 to 12 carbon atoms, n represents an integer of 1 to 2, and when n is 2, L's may be the same or different.

[0017] 2) The arylamine compound according to 1) above, wherein in the general formula (1), R1 and R2 may be the same or different and each represent a hydrogen atom or a deuterium atom.

[0018] 3) The arylamine compound according to 1) above, wherein in the general formula (1), L is a substituted or unsubstituted phenylene group.

[0019] 4) The arylamine compound according to 1) above, wherein, in the general formula (1), Ar1 and Ar2 may be the same or different and are a substituted or unsubstituted phenyl group, a substituted or unsubstituted naphthyl group, a substituted or unsubstituted biphenylyl group, a substituted or unsubstituted terphenylyl 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.

[0020] 5) The arylamine compound according to 1) above, wherein n is 1 in the general formula (1).

[0021] 6) An organic EL device having a pair of electrodes and at least one organic layer sandwiched therebetween, wherein the organic layer contains the arylamine compound described in any one of 1) to 5).

[0022] 7) The organic EL device according to 6) above, wherein the organic layer is a hole transport layer.

[0023] 8) The organic EL device according to 6) above, wherein the organic layer is an electron blocking layer.

[0024] 9) An electronic device using an element having a pair of electrodes and at least one organic layer sandwiched therebetween, wherein the organic layer contains the arylamine compound according to any one of 1) to 5). [Effects of the Invention]

[0025] 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, and is therefore useful as an electron blocking material or hole transporting material. Organic electroluminescence devices using the compound of the present invention as a material for an organic layer can achieve low driving voltage, high luminous efficiency, and long device life. [Brief explanation of the drawings]

[0026] [Figure 1] FIG. 1 shows compounds (1-1) to (1-12) as preferred specific examples of the arylamine compound represented by general formula (1). [Figure 2] FIG. 1 shows compounds (1-13) to (1-24) as preferred specific examples of the arylamine compound represented by general formula (1). [Figure 3] FIG. 1 shows compounds (1-25) to (1-36) as preferred specific examples of the arylamine compound represented by general formula (1). [Figure 4]FIG. 1 shows compounds (1-37) to (1-48) as preferred specific examples of the arylamine compound represented by general formula (1). [Figure 5] FIG. 1 shows compounds (1-49) to (1-60) as preferred specific examples of the arylamine compound represented by general formula (1). [Figure 6] FIG. 1 shows compounds (1-61) to (1-72) as preferred specific examples of the arylamine compound represented by general formula (1). [Figure 7] FIG. 1 shows compounds (1-73) to (1-84) as preferred specific examples of the arylamine compound represented by general formula (1). [Figure 8] FIG. 1 shows compounds (1-85) to (1-96) as preferred specific examples of the arylamine compound represented by general formula (1). [Figure 9] FIG. 1 shows compounds (1-97) to (1-105) as preferred specific examples of the arylamine compound represented by general formula (1). [Figure 10] FIG. 1 shows compounds (1-106) to (1-117) as preferred specific examples of the arylamine compound represented by general formula (1). [Figure 11] FIG. 1 is a diagram showing the configurations of the organic EL devices of Examples 16 to 20 and Comparative Example 1. DETAILED DESCRIPTION OF THE INVENTION

[0027] The present invention will be described in detail below. The following description of the constituent elements may be based on representative 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 that includes the numerical values ​​before and after "to" as the lower and upper limits.

[0028] In the "substituted or unsubstituted aromatic hydrocarbon group" represented by Ar1 and Ar2 in general formula (1), the aromatic ring constituting the "aromatic hydrocarbon group" (aryl group) may be a monocyclic ring, a fused ring (fused polycyclic aromatic group) in which two or more rings are fused, a linked ring in which two or more rings 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 the range of 6 to 30. Specific examples of the "aromatic hydrocarbon group" include a phenyl group, a biphenylyl group, a terphenylyl 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, and a spirobifluorenyl group.

[0029] 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 in which two or more rings are fused. 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 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 benzoxazolyl 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.

[0030] Examples of the "substituted aromatic hydrocarbon group" and "substituted aromatic heterocyclic group" represented by Ar1 and Ar2 in general formula (1) include 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; and phenyl groups. aromatic hydrocarbon groups or condensed polycyclic aromatic groups such as a biphenylyl 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, or 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, or a carbolinyl group, and 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.

[0031] Examples of the "aromatic hydrocarbon group" and "aromatic heterocyclic group" in the "divalent group of a substituted or unsubstituted aromatic hydrocarbon group" and "divalent group of a substituted or unsubstituted aromatic heterocyclic group" represented by L in general formula (1) include the same as those shown as 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 Ar1 and Ar2 in general formula (1). Specific examples of the "divalent group of an aromatic hydrocarbon group" include divalent groups obtained by removing one hydrogen atom from the specific examples of the monovalent "aromatic hydrocarbon group" above, and specific examples of the "divalent aromatic heterocyclic group" include divalent groups obtained by removing one hydrogen atom from the specific examples of the monovalent "aromatic heterocyclic group" above.

[0032] Examples of the "substituent" in the "substituted or unsubstituted aromatic hydrocarbon group" and "substituted or unsubstituted aromatic heterocyclic group" represented by L in general formula (1) include the same as those shown as the "substituent" in the "substituted aromatic hydrocarbon group" and "substituted aromatic heterocyclic group" represented by Ar1 and Ar2 in general formula (1), and possible embodiments thereof are also similar.

[0033] R to R in general formula (1) 17In the "straight-chain or branched alkyl group of 1 to 6 carbon atoms which may have a substituent," "cycloalkyl group of 5 to 10 carbon atoms which may have a substituent," or "straight-chain or branched alkenyl group of 2 to 6 carbon atoms which may have a substituent," represented by the following formula, examples of the "straight-chain or branched alkyl group of 1 to 6 carbon atoms," "cycloalkyl group of 5 to 10 carbon atoms," or "straight-chain or branched alkenyl group of 2 to 6 carbon atoms" include, for example, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an ethyl ... Examples of the aryl group include an aryl group, an isobutyl group, a tert-butyl group, an n-pentyl group, an isopentyl group, a neopentyl group, an n-hexyl group, a cyclopentyl group, a cyclohexyl group, a 1-adamantyl group, a 2-adamantyl group, a vinyl group, an allyl group, an isopropenyl group, and a 2-butenyl 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.

[0034] R to R in general formula (1) 17 Examples of the "substituent" in the "linear or branched alkyl group of 1 to 6 carbon atoms which may have a substituent," "cycloalkyl group of 5 to 10 carbon atoms which may have a substituent," or "linear or branched alkenyl group of 2 to 6 carbon atoms which may have a substituent" represented by the above formula include the same as those shown as the "substituent" in the "substituted aromatic hydrocarbon group" and "substituted aromatic heterocyclic group" represented by Ar1 and Ar2 in general formula (1), and possible embodiments thereof are also similar.

[0035] R to R in general formula (1) 17Examples of the "straight-chain or branched alkyloxy group having 1 to 6 carbon atoms" or "cycloalkyloxy group having 5 to 10 carbon atoms" in the "straight-chain or branched alkyloxy group having 1 to 6 carbon atoms which may have a substituent" or "cycloalkyloxy group having 5 to 10 carbon atoms which may have a substituent" 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, an n-hexyloxy group, 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.

[0036] R to R in general formula (1) 17 Examples of the "substituent" in the "linear or branched alkyloxy group having 1 to 6 carbon atoms which may have a substituent" or the "cycloalkyloxy group having 5 to 10 carbon atoms which may have a substituent" represented by the above formula (1) include the same as those shown as the "substituent" in the "substituted aromatic hydrocarbon group" and "substituted aromatic heterocyclic group" represented by Ar1 and Ar2 in general formula (1), and possible embodiments thereof are also similar.

[0037] R to R in general formula (1) 17 Examples of 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 Ar1 and Ar2 in general formula (1) can be the same as those given as 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 Ar1 and Ar2 in general formula (1).

[0038] R to R in general formula (1) 17 Examples of the "substituent" in the "substituted or unsubstituted aromatic hydrocarbon group" and "substituted or unsubstituted aromatic heterocyclic group" represented by the following formula (1) can be the same as those given as the "substituent" in the "substituted aromatic hydrocarbon group" and "substituted aromatic heterocyclic group" represented by Ar1 and Ar2 in general formula (1), and possible embodiments can also be the same.

[0039] R to R in general formula (1) 17 Examples of the "aryloxy group" in the "substituted or unsubstituted aryloxy group" represented by the formula (I) include 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, a triphenylenyloxy group, a benzofuranyloxy group, a benzothienyloxy group, an indolyloxy group, a carbazolyloxy group, a dibenzofuranyloxy group, and a dibenzothienyloxy group, as well as an aryl group having 6 to 30 carbon atoms or a heteroaryl group having 2 to 20 carbon atoms. 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.

[0040] R to R in general formula (1) 17Examples of the "substituent" in the "linear or branched alkyl group of 1 to 6 carbon atoms which may have a substituent", "cycloalkyl group of 5 to 10 carbon atoms which may have a substituent", "linear or branched alkenyl group of 2 to 6 carbon atoms which may have a substituent", "linear or branched alkyloxy group of 1 to 6 carbon atoms which may have a substituent", "cycloalkyloxy group of 5 to 10 carbon atoms which may have a substituent", "substituted or unsubstituted aromatic hydrocarbon group", "substituted or unsubstituted aromatic heterocyclic group", and "substituted or unsubstituted aryloxy group" represented by the above formula include the same as those shown as the "substituent" in the "substituted aromatic hydrocarbon group" and "substituted aromatic heterocyclic group" represented by Ar1 and Ar2 in general formula (1), and possible embodiments thereof are also similar.

[0041] In general formula (1), Ar1 or Ar2 is preferably a substituted or unsubstituted phenyl group, a substituted or unsubstituted biphenylyl group, a substituted or unsubstituted naphthyl group, a substituted or unsubstituted phenanthrenyl group, or a substituted or unsubstituted terphenylyl group, and more preferably a substituted or unsubstituted phenyl group, a substituted or unsubstituted biphenylyl group, or a substituted or unsubstituted terphenylyl group. The substituent is preferably a deuterium atom, a linear or branched alkyl group having 1 to 6 carbon atoms, a linear or branched alkyloxy group having 1 to 6 carbon atoms, an aryloxy group, an aromatic hydrocarbon group or a condensed polycyclic aromatic group, or an aromatic heterocyclic group, and more preferably a deuterium atom, an aromatic hydrocarbon group or a condensed polycyclic aromatic group, or an aromatic heterocyclic group, and these substituents may be further substituted with the substituents exemplified above.

[0042] L in general formula (1) is preferably a substituted or unsubstituted phenylene group, a substituted or unsubstituted biphenylene group, or a substituted or unsubstituted naphthylene group, more preferably a substituted or unsubstituted phenylene group or a substituted or unsubstituted biphenylene group. The substituent is preferably a deuterium atom, a linear or branched alkyl group having 1 to 6 carbon atoms, a linear or branched alkyloxy group having 1 to 6 carbon atoms, an alkenyl group, an aryloxy group, an aromatic hydrocarbon group or a condensed polycyclic aromatic group, or an aromatic heterocyclic group, more preferably a deuterium atom, and these substituents may be further substituted with the substituents exemplified above.

[0043] R1 and R2 in general formula (1) are preferably hydrogen atoms or deuterium atoms. R3~R 17 is preferably a hydrogen atom, a deuterium atom, a linear or branched alkyl group of 1 to 6 carbon atoms which may have a substituent, a linear or branched alkenyl group of 2 to 6 carbon atoms which may have a substituent, a linear or branched alkyloxy group of 1 to 6 carbon atoms which may have a substituent, a substituted or unsubstituted aromatic hydrocarbon group, a substituted or unsubstituted aromatic heterocyclic group, or a substituted or unsubstituted aryloxy group, and more preferably a hydrogen atom, a deuterium atom, a substituted or unsubstituted aromatic hydrocarbon group, or a substituted or unsubstituted aromatic heterocyclic group.

[0044] The arylamine compounds of the present invention are novel compounds, but these compounds can be synthesized according to methods known per se (see, for example, Patent Document 5).

[0045] The arylamine 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.

[0046] Among the arylamine compounds represented by the general formula (1) that are suitably used in the organic EL device of the present invention, specific examples of preferred compounds are shown in Figures 1 to 10, but the compounds are not limited to these. 1 H) is omitted. m (m represents 1 to 5) is a deuterium atom ( 2 H), and m indicates the number of deuterium substitutions per benzene ring.

[0047] The compound represented by general formula (1) of the present invention has excellent hole transporting ability and electron blocking ability, and has high thermal stability in a thin film state, and is therefore 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.

[0048] 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 point (Tg), and work function (HOMO energy level). The melting point is an indicator of vapor deposition properties, the glass transition point (Tg) is an indicator of the stability of the thin film state, and the work function is an indicator of hole injection properties, hole transport properties, or electron blocking properties.

[0049] 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.

[0050] The work function (HOMO energy level) can be determined, for example, by forming a 100 nm thin film on an ITO (Indium Tin Oxide) substrate and measuring it with an ionization potential measuring device (PYS-202, manufactured by Sumitomo Heavy Industries, Ltd.).

[0051] <Organic electroluminescence element> The organic electroluminescence device (organic EL device) of the present invention has a pair of electrodes and an organic layer including at least a light-emitting layer between the pair of electrodes, and may include one or more organic layers in addition to the light-emitting layer. Here, the pair of electrodes is an anode and a cathode. 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. Materials for these organic layers can be appropriately selected from known materials.

[0052] 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. It may also have 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, a single organic layer may serve multiple functions. For example, a single 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. It may also have a structure in which two or more organic layers having the same function are stacked, such as a structure in which two hole transport layers are stacked, a structure in which two emitting layers are stacked, or a structure in which two electron transport layers are stacked. The organic EL device of the present invention may have at least an anode, a hole transport layer, an emitting layer, an electron transport layer, and a cathode in the above order, and this does not exclude embodiments in which other layers are present between the layers.

[0053] [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.

[0054] [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. Materials that can be used for the hole injection layer of the organic EL device of the present invention include phthalocyanine compounds typified by copper phthalocyanine, starburst 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 containing no 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.

[0055] In addition to the arylamine compound represented by general formula (1) 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 or carbazolyl structures in the molecule, each linked by a single bond or a divalent group containing no heteroatoms. 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.

[0056] 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.

[0057] The arylamine compound of the present invention represented by general formula (1) 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 can improve the efficiency of hole transport to the light-emitting layer, thereby improving the luminous efficiency and thereby improving the durability of the device, and can achieve high efficiency and long life characteristics.

[0058] [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. In addition to the arylamine compound represented by general formula (1) of the present invention, other materials that can be used for the electron-blocking layer of the organic EL device of the present invention 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. 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 each 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.

[0059] The arylamine compound of the present invention represented by general formula (1) has excellent electron blocking ability, high electron tolerance, and is stable even in a thin film state, and is characterized by trapping excitons generated in the light-emitting layer. As a result, organic EL devices having an electron-blocking layer prepared using this 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.

[0060] [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. In addition to the arylamine compound represented by general formula (1) of the present invention, other materials for the light-emitting layer of the organic EL device of the present invention can be used, such as metal complexes of quinolinol derivatives, including tris(8-quinolinolato)aluminum (Alq3), various metal complexes, anthracene derivatives, bisstyrylbenzene derivatives, pyrene derivatives, oxazole derivatives, and polyparaphenylenevinylene derivatives. The light-emitting layer can 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, including 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 can 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.

[0061] 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.

[0062] 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.

[0063] Furthermore, as the light-emitting material, it is also possible to use materials that emit delayed fluorescence, such as triazine derivatives such as PIC-TRZ and CC2TA, phenoxazine derivatives such as PXZ-TRZ, and carbazolyldicyanobenzene derivatives (CDCB derivatives) such as 4CzIPN (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.

[0064] The arylamine compound of the present invention represented by general formula (1) has excellent hole-transporting properties and a wide band gap. As a result, an organic EL device having an emissive layer fabricated using the compound as a host material can have a reduced driving voltage and improved luminous efficiency by forming the emissive layer by supporting a fluorescent emitter, a phosphorescent emitter, or a delayed fluorescent emitter, which are called dopants.

[0065] [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). 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.

[0066] [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.

[0067] 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.

[0068] 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.

[0069] Furthermore, for the electron injection layer and the electron transport layer, materials that are usually used for these layers and to which a metal such as cesium is added (N-type dopant) can be used.

[0070] [cathode] 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.

[0071] The arylamine compound represented by the general formula (1) 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.

[0072] Therefore, the arylamine compound of the present invention represented by general formula (1) 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.

[0073] In addition, the arylamine compound of the present invention represented by general formula (1) can be used not only in organic EL devices but also in the field of electronic devices such as electrophotographic photoreceptors, image sensors, photoelectric conversion elements, and solar cells.

[0074] <Electronic equipment> The electronic device of the present invention includes an element having 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, and 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 and vehicle lamps. [Example]

[0075] 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.

[0076] Example 1: Synthesis of 2-(3,4,5-triphenylphenyl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (Intermediate (1)) A reaction vessel was charged with 17.5 g of 1-chloro-3,4,5-triphenylbenzene, 15.7 g of bis(pinacolato)diboron, 0.47 g of tris(dibenzylideneacetone)dipalladium(0), 0.85 g of 2-dicyclohexylphosphino-2',6'-dimethoxybiphenyl, 15.2 g of potassium acetate, and 165 mL of 1,4-dioxane, and refluxed for 8 hours. After cooling, 200 mL of toluene was added and the mixture was filtered. The filtrate was evaporated to dryness, and the solid was dissolved in toluene. The organic layer was washed twice with purified water and once with saturated brine, and then dried over sodium sulfate. Silica gel was added to the organic layer, and the mixture was stirred at room temperature for 1 hour. The silica gel was removed by filtration, and the obtained filtrate was evaporated to dryness to obtain 18.3 g (yield: 96%) of white powder of 2-(3,4,5-triphenylphenyl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (intermediate (1)).

[0077] [ka]

[0078] [Example 2] <Synthesis of 5-(p-bromophenyl)-1,2,3-triphenylbenzene (intermediate (2))> A reaction vessel was charged with 12.5 g of intermediate 1, 1.0 g of tetrakis(triphenylphosphine)palladium(0), 10.2 g of 1-bromo-4-iodobenzene, 12.0 g of potassium carbonate, 40 mL of toluene, 6 mL of ethanol, and 7 mL of purified water, and refluxed for 14 hours. After cooling, MeOH was added, and the precipitated solid was collected by filtration. The resulting crude product was purified by column chromatography (carrier: silica gel, eluent: chloroform / n-hexane = 1:5 (V / V)) to obtain 10.7 g (80% yield) of a white powder of intermediate (2).

[0079] [ka]

[0080] [Example 3] <Synthesis of Compound (1-1)> A reaction vessel was charged with 2.7 g of bis(4-biphenylyl)amine, 3.9 g of intermediate 2, 1.2 g of sodium tert-butoxide, 38 mg of palladium acetate, 68 mg of tri-tert-butylphosphine, and 31 mL of toluene, and the mixture was refluxed for 3 hours. After cooling, toluene was added and the mixture was filtered. 20 g of silica gel was added to the filtrate, and the mixture was stirred at room temperature for 1 hour. The filtrate was filtered and evaporated to dryness. The resulting solid was recrystallized from toluene / acetone. The resulting white powder was dried to obtain 5.2 g of compound (1-1) (yield: 80%).

[0081] The structure of the obtained white powder was identified using NMR. 1 The following 39 hydrogen signals were detected by H-NMR (CDCl3). δ(ppm)=7.67-7.53(17H),7.45(4H),7.38-7.30(2H),7.29-7.28(4H),7.18-7.12(7H),7.00-6.98(3H),6.88-6.86(2H).

[0082] [ka]

[0083] [Example 4] <Synthesis of Compound (1-2)> A reaction vessel was charged with 3.0 g of N-(4-biphenylyl)-[1,1':4',1''-terphenyl]-4-amine, 3.7 g of intermediate 2, 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. After cooling, toluene was added and the mixture was filtered. 18 g of silica gel was added to the filtrate, and the mixture was stirred at room temperature for 1 hour. The filtrate was filtered and evaporated to dryness. The resulting solid was recrystallized from toluene / acetone. The resulting white powder was dried to obtain 5.5 g of compound (1-2) (yield: 93%).

[0084] The structure of the obtained white powder was identified using NMR. 1 The following 43 hydrogen signals were detected by H-NMR (CDCl3). δ(ppm)=7.67-7.53(17H),7.45(4H),7.38-7.30(1H),7.29-7.28(6H),7.18-7.12(10H),7.00-6.98(3H),6.88-6.86(2H).

[0085] [ka]

[0086] [Example 5] <Synthesis of compound (1-3)> A reaction vessel was charged with 3.0 g of (3,4-diphenylphenyl)-4-biphenylamine, 3.5 g of intermediate 2, 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. After cooling, toluene was added and the mixture was filtered. 18 g of silica gel was added to the filtrate, and the mixture was stirred at room temperature for 1 hour. The filtrate was filtered and evaporated to dryness. The resulting solid was recrystallized from toluene / acetone. The resulting white powder was dried to obtain 3.9 g of compound (1-3) (yield: 67%).

[0087] The structure of the obtained white powder was identified using NMR. 1 The following 43 hydrogen signals were detected by H-NMR (CDCl3). δ(ppm)=7.67(2H),7.62(4H),7.55-7.52(2H),7.43(2H),7.35-7.29(7H),7.25(2H),7.22-7.08(19H),7.00-6.98(3H),6.87-6.85(2H).

[0088] [ka]

[0089] [Example 6] <Synthesis of compound (1-15)>

[0090] A reaction vessel was charged with 10.7 g of N-phenyl-4-bis(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)aniline, 15.3 g of 1-chloro-3,4,5-triphenylbenzene, 0.59 g of tris(dibenzylideneacetone)dipalladium(0), 0.70 g of 2-dicyclohexylphosphino-2',6'-dimethoxybiphenyl, 13.6 g of tripotassium phosphate, 55 mL of toluene, 5.6 mL of EtOH, and 11 mL of HO, and the mixture was refluxed for 7 hours. After cooling, the organic layer was washed with purified water and saturated brine. The organic layer was washed with sodium sulfate. The organic layer was evaporated to dryness, and the resulting solid was dissolved in toluene. 36 g of silica gel was added to the resulting organic layer, and the mixture was stirred at 50°C for 1 hour. Filtration was performed, and the filtrate was evaporated to dryness. The resulting crude product was recrystallized from toluene to obtain 10.9 g (yield: 59%) of compound (1-15) as a white powder.

[0091] The structure of the obtained white powder was identified by NMR. 1 The following 47 hydrogen signals were detected by H-NMR (CDCl3). δ(ppm)=7.66(4H),7.61(4H),7.30(2H),7.22-7.12(26H),7.07(1H),6.99-6.97(6H),6.87-6.85(4H).

[0092] [ka]

[0093] [Example 7] <Synthesis of compound (1-16)> A reaction vessel was charged with 3.2 g of N-phenyl[3'-(9-9H-carbazolyl)-4-biphenylyl]amine, 3.8 g of intermediate 2, 1.1 g of sodium tert-butoxide, 35 mg of palladium acetate, 63 mg of tri-tert-butylphosphine, and 45 mL of toluene, and the mixture was refluxed for 4 hours. After cooling, toluene was added and the mixture was filtered. 18 g of silica gel was added to the filtrate, and the mixture was stirred at room temperature for 1 hour. The filtrate was filtered and evaporated to dryness. The resulting solid was recrystallized from toluene / acetone. The resulting white powder was dried to obtain 3.0 g of compound (1-16) (yield: 49%).

[0094] The structure of the obtained white powder was identified by NMR. 1 The following 42 hydrogen signals were detected by H-NMR (CDCl3). δ(ppm)=8.16(2H),7.79(1H),7.68-7.65(4H),7.60(2H),7.56-7.47(5H),7. 42(2H), 7.31-7.28(4H), 7.22-7.08(17H), 7.00-6.98(3H), 6.87-6.85(2H).

[0095] [ka]

[0096] [Example 8] <Synthesis of compound (1-8)> A reaction vessel was charged with 10.7 g of N-(4-biphenylyl)-(3',5'-biphenyl-[1,1':4',1'']-terphenyl)-4-amine, 6.1 g of 1-(4-bromophenyl)naphthalene, 2.8 g of sodium tert-butoxide, 0.3 g of tri-tert-butylphosphine, 0.1 g of palladium(II) acetate, and 107 mL of toluene, and the mixture was heated under reflux and stirred for 3 hours. After confirming the completion of the reaction, the mixture was filtered hot through silica gel. The filtrate was concentrated, and the resulting crude product was recrystallized from dichloromethane / acetone to give 12.3 g of compound (1-8) (yield: 84%).

[0097] The structure of the obtained white powder was identified using NMR. 1 The following 41 hydrogen signals were detected by H-NMR (CDCl3). δ(ppm)=8.05(1H),7.92(1H),7.86(1H),7.69-7.61(6H),7.58-7.43(10 H),7.35-7.30(7H),7.19-7.14(10H),7.01-6.98(3H),6.89-6.86(2H).

[0098] [ka]

[0099] [Example 9] <Synthesis of compound (1-74)> A reaction vessel was charged with 22.0 g of N-(4-biphenylyl)-([1,1':4',1'']-terphenyl-2,3,5,6-d4)-4-(4-bromo-phenyl-2,3,5,6-d4)-1-amine, 18.0 g of intermediate (1), 17.0 g of potassium carbonate, 1.0 g of [1,1'-bis(diphenylphosphino)ferrocene]palladium(II) dichloride dichloromethane adduct, 68 mL of toluene, 14 mL of ethanol, and 28 mL of water, and the mixture was heated and stirred under reflux for 4 hours. After confirming the completion of the reaction, activated clay and silica gel were added, and the mixture was stirred for 30 minutes and then filtered through Celite. The filtrate was concentrated, and the resulting crude product was recrystallized from toluene to obtain 25.0 g of compound (1-74) (yield: 79%).

[0100] The structure of the obtained white powder was identified using NMR. 1 The following 35 hydrogen signals were detected by H-NMR (CDCl3). δ(ppm)=7.68(6H),7.66(2H),7.61(2H),7.54(2H),7.48-7.43(4H),7.37-7.31(2H),7.27(2H),7.18-7.13(10H),7.00-6.98(3H),6.87(2H).

[0101] [ka]

[0102] [Example 10] <Synthesis of compound (1-100)> A reaction vessel was charged with 4.0 g of N-(4-biphenylyl)-([1,1':4',1'']-terphenyl-2,3,5,6-d4)-4-amine, 4.9 g of intermediate (2), 1.5 g of sodium tert-butoxide, 0.2 g of tri-tert-butylphosphine, 0.3 g of tris(dibenzylideneacetone)dipalladium(0), and 40 mL of toluene, and the mixture was stirred under reflux for 2.5 hours. After confirming the completion of the reaction, activated clay and silica gel were added, and the mixture was stirred for 30 minutes and then filtered through Celite. The filtrate was concentrated, and the resulting crude product was recrystallized from toluene to obtain 3.5 g of compound (1-100) (yield: 44%).

[0103] The structure of the obtained white powder was identified using NMR. 1 The following 39 hydrogen signals were detected by H-NMR (DMSO-d6). δ(ppm)=7.81-7.65(14H),7.50-7.43(4H),7.40-7.32(2H),7.20-7.12(14H),7.02-7.01(3H),6.87-6.84(2H).

[0104] [ka]

[0105] [Example 11] <Synthesis of compound (1-101)> A reaction vessel was charged with 4.0 g of N-(4-biphenylyl)-([1,1':4',1'']-terphenyl)-4-amine, 4.9 g of 4-bromo-3',5'-diphenyl-[1,1':4',1'']-terphenyl-2,3,5,6-d4, 1.5 g of sodium tert-butoxide, 0.2 g of tri-tert-butylphosphine, 0.3 g of tris(dibenzylideneacetone)dipalladium(0), and 40 mL of toluene, and the mixture was heated under reflux and stirred for 2.5 hours. After confirming the completion of the reaction, activated clay and silica gel were added, and the mixture was stirred for 30 minutes and then filtered through Celite. The filtrate was concentrated, and the resulting crude product was recrystallized from toluene to obtain 5.3 g of compound (1-101) (yield: 68%).

[0106] The structure of the obtained white powder was identified using NMR. 1 The following 39 hydrogen signals were detected by H-NMR (DMSO-d6). δ(ppm)=7.79-7.65(14H),7.50-7.43(4H),7.39-7.32(2H),7.21-7.12(14H),7.02-7.01(3H),6.87-6.84(2H).

[0107] [ka]

[0108] [Example 12] <Synthesis of compound (1-106)> A reaction vessel was charged with 11.7 g of N-(4-biphenylyl)-(3',5'-biphenyl-[1,1':4',1'':3'',1''']quaterphenyl)-4-amine, 5.3 g of 4-bromobiphenyl, 2.7 g of sodium tert-butoxide, 0.3 g of tri-tert-butylphosphine, 0.1 g of palladium(II) acetate, and 117 mL of toluene, and the mixture was heated and stirred under reflux for 3 hours. After confirming the completion of the reaction, silica gel was added, and the mixture was stirred for 30 minutes and then filtered through Celite. The filtrate was concentrated, and the resulting crude product was recrystallized from dichloromethane / n-heptane to obtain 6.5 g of compound (1-106) (yield: 45%).

[0109] The structure of the obtained white powder was identified using NMR. 1 The following 43 hydrogen signals were detected by H-NMR (CDCl3). δ(ppm)=7.71(2H),7.65-7.60(6H),7.54(4H),7.44(4H),7.35-7.17(22H),7.12-7.10(3H),7.06(1H),6.83(1H).

[0110] [ka]

[0111] [Example 13] <Synthesis of compound (1-114)> A reaction vessel was charged with 2.0 g of bis(4-biphenylyl)amine, 3.3 g of 4-bromo-3'',5''-biphenyl-[1,1':4',1'':4'',1''']quaterphenyl, 0.9 g of sodium tert-butoxide, 0.1 g of tri-tert-butylphosphine, 0.1 g of palladium acetate, and 20 mL of toluene, and the mixture was stirred under reflux for 2.5 hours. After confirming the completion of the reaction, activated clay and silica gel were added, and the mixture was stirred for 30 minutes and then filtered through Celite. The filtrate was concentrated, and the resulting crude product was recrystallized from toluene to obtain 2.7 g of compound (1-114) (yield: 55%).

[0112] The structure of the obtained white powder was identified using NMR. 1 The following 43 hydrogen signals were detected by H-NMR (CDCl3). δ(ppm)=7.78(2H),7.74(2H),7.69(2H),7.60(6H),7.53(4H),7.44(4H) ,7.33(2H),7.27(3H),7.25(3H),7.21-7.15(10H),6.99(3H),6.88(2H).

[0113] [ka]

[0114] [Example 14]<Measurement of Glass Transition Temperature> The glass transition temperatures of each of the compounds synthesized in Examples 3 to 13 and EBM-1 having the following structure disclosed in Patent Document 5 as a comparative compound were measured using a high-sensitivity differential scanning calorimeter (manufactured by Rigaku, DSCvesta Thermо plus EV02 series). The results of the measured glass transition temperatures (°C) are summarized in Table 1.

[0115] [Chemical Formula]

[0116] [Table 1]

[0117] While the glass transition temperature of the comparative compound (EBM-1) is 103°C, the arylamine compound represented by the general formula (1) has a glass transition point of 119°C or higher, indicating that the thin film state is stable. Therefore, it was confirmed that an element with excellent thermal stability can be fabricated by using the arylamine compound represented by the general formula (1) in an organic EL element.

[0118] [Example 15]<Measurement of HOMO Level> On an ITO substrate, each of the compounds synthesized in Examples 3 to 13 was formed into a vapor-deposited film with a film thickness of 100 nm by a vacuum vapor deposition method. For each of the fabricated thin films, the energy level of HOMO (corresponding to the absolute value of the HOMO level) was measured using an ionization potential measuring device (Sumitomo Heavy Industries, Ltd., PYS-202). The results of the absolute values of the HOMO levels are shown in Table 2.

[0119] [Table 2]

[0120] The arylamine compound represented by general formula (1) exhibits a more favorable energy level than the HOMO energy level of 5.4 eV of common hole transport materials such as NPD and TPD, and has good hole transport ability.

[0121] [Example 16] <Evaluation of organic EL> As shown in Figure 11, 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.

[0122] 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 ITO-coated glass substrate was placed in a vacuum deposition machine and the pressure was reduced to 0.001 Pa or less. Subsequently, a hole injection layer 3 was formed to cover the transparent anode 2 by binary deposition of an electron acceptor (Acceptor-1) having the following structural formula and a compound (BCFN) having the following structural formula at a deposition rate ratio of Acceptor-1:BCFN=3:97, to a thickness of 10 nm. On this hole injection layer 3, a compound (BCFN) having the following structural formula was formed as a hole transport layer 4 to a thickness of 140 nm. On this hole transport layer 4, the compound (1-1) of Example 3 was formed as an electron blocking layer 5 to a thickness of 5 nm. On this electron blocking layer 5, a compound (Dopant-1) having the following structural formula and a compound (ADN) having the following structural formula were deposited by binary deposition at a deposition rate ratio of Dopant-1:ADN=2:98 to form an emitting layer 6 having a thickness of 20 nm. On this light-emitting layer 6, an electron transport layer 7 was formed by binary deposition of a compound (ETM-1) with the following structural formula and a compound (ETM-2) with the following structural formula at a deposition rate ratio of ETM-1:ETM-2=50:50, to a thickness of 30 nm. On this electron transport layer 7, an electron injection layer 8 was formed of lithium fluoride to a thickness of 1 nm. On this electron injection layer 8, a cathode 9 made of a magnesium-silver alloy was formed to a thickness of 12 nm. Finally, a compound (CPL-1) having the following structure was formed as a capping layer 10 to a thickness of 60 nm. The fabricated organic EL devices were subjected to measurements of device characteristics and device lifespan in the atmosphere at room temperature. The results are summarized in Table 3. The device lifespan was measured when the emission luminance at the start of light emission (initial luminance) was increased to 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.

[0123] [ka]

[0124] [ka]

[0125] [ka]

[0126] [ka]

[0127] [Example 17] An organic EL device was fabricated under the same conditions as in Example 16, except that compound (1-2) was used instead of compound (1-1) 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.

[0128] [Example 18] An organic EL device was fabricated under the same conditions as in Example 16, except that compound (1-3) was used instead of compound (1-1) 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.

[0129] [Example 19] An organic EL device was fabricated under the same conditions as in Example 16, except that compound (1-15) was used instead of compound (1-1) 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.

[0130] [Example 20] An organic EL device was fabricated under the same conditions as in Example 16, except that compound (1-16) was used instead of compound (1-1) 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.

[0131] [Example 21] An organic EL device was fabricated under the same conditions as in Example 16, except that compound (1-74) was used instead of compound (1-1) 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.

[0132] [Example 22] An organic EL device was fabricated under the same conditions as in Example 16, except that compound (1-106) was used instead of compound (1-1) 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.

[0133] [Example 23] An organic EL device was fabricated under the same conditions as in Example 16, except that compound (1-114) was used instead of compound (1-1) 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.

[0134] [Comparative Example 1] For comparison, an organic EL device was fabricated under the same conditions as in Example 16, except that EBM-1 was used instead of compound (1-1) 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.

[0135] [Table 3]

[0136] As shown in Table 3, the current density was 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, and thus the organic EL elements of Examples 16 to 23 were highly efficient, ranging from 10.94 to 11.63 cd / A. The power efficiency was also high, ranging from 9.14 to 10.02 lm / W, and thus the organic EL elements of Examples 16 to 23 were highly efficient, ranging from 9.12 lm / W, and thus the organic EL elements of Comparative Example 1 were 9.12 lm / W. Furthermore, the element lifetime (at 95% decay) was 370 to 500 hours, and thus the organic EL elements of Examples 16 to 23 were longer, ranging from 363 hours, and thus the organic EL elements of Comparative Example 1 were 370 to 500 hours.

[0137] As is clear from the above results, the compound represented by general formula (1) according to the present invention has higher thermal stability, better hole transport properties, and better electron blocking properties than conventional materials. Therefore, it has been found that an organic EL device according to the present invention using the compound can realize an organic EL device with higher luminous efficiency and longer life than conventional organic EL devices. [Industrial Applicability]

[0138] 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 expand the use of the organic EL device to, for example, home appliances and lighting. [Explanation of symbols]

[0139] 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 (1): 【Chemical 1】 (In the formula, Ar １ and Ar ２ are each the same or different and represent a substituted or unsubstituted aromatic hydrocarbon group or a substituted or unsubstituted aromatic heterocyclic group, L represents a divalent group of a substituted or unsubstituted aromatic hydrocarbon group or a divalent group of a substituted or unsubstituted aromatic heterocyclic group; R １ ~R １７ each 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, an optionally substituted linear or branched alkyl group of 1 to 6 carbon atoms, an optionally substituted cycloalkyl group of 5 to 10 carbon atoms, an optionally substituted linear or branched alkenyl group of 2 to 6 carbon atoms, an optionally substituted linear or branched alkyloxy group of 1 to 6 carbon atoms, an optionally substituted cycloalkyloxy group of 5 to 10 carbon atoms, a substituted or unsubstituted aryloxy group, an optionally substituted aromatic hydrocarbon group of 5 to 12 carbon atoms, or an optionally substituted aromatic heterocyclic group of 4 to 12 carbon atoms, n represents an integer of 1 to 2, and when n is 2, L's may be the same or different.

2. In the general formula (1), R １ ~R ２ The arylamine compound according to claim 1 , wherein each of the groups may be the same or different and is a hydrogen atom or a deuterium atom.

3. 2. The arylamine compound according to claim 1, wherein in the general formula (1), L is a substituted or unsubstituted phenylene group.

4. In the general formula (1), Ar １ and Ar ２ and each may be the same or different and is a substituted or unsubstituted phenyl group, a substituted or unsubstituted naphthyl group, a substituted or unsubstituted biphenylyl group, a substituted or unsubstituted terphenylyl 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.

5. The arylamine compound according to claim 1, wherein n is 1 in the general formula (1).

6. 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 according to any one of claims 1 to 5.

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

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

9. An electronic device using an element having a pair of electrodes and at least one organic layer sandwiched between them, wherein the organic layer contains the arylamine compound according to any one of claims 1 to 5.

Images