Arylamine compound, organic electroluminescent element, and electronic appliance

Abstract

Provided is an arylamine compound which, when used as a material for organic EL elements having high efficiency and durability, is excellent in terms of hole injection / transport performance, has an excellent electron-blocking ability, is highly stable in a thin film state, and has excellent durability. This arylamine compound is represented by general formula (I). In general formula (I), Ar1 and Ar2 each represent an aryl group or a heteroaryl group, L1 to L3 each represent a single bond, an arylene group, or a heteroarylene group, and A represents a disubstituted or trisubstituted naphthyl group.

Description

Arylamine compound, organic electroluminescent element, and electronic device

[0001] The present invention relates to an arylamine compound suitable for organic electroluminescence elements (hereinafter abbreviated as "organic EL elements") suitable for various display devices, and to an organic EL element and electronic equipment using the compound.

[0002] Organic EL elements are self-luminous elements, and therefore are brighter, more visible, and capable of clearer displays than liquid crystal elements, and have therefore been the subject of active research. In 1987, C. W. Tang et al. of Eastman Kodak Company developed a layered structure element in which various roles are assigned to different materials, thereby making organic EL elements using organic materials practical. To date, many improvements have been made to make organic EL elements practical, and the various roles of the layered structure have been further subdivided, resulting in electroluminescent elements having an anode, a hole injection layer, a hole transport layer, a light-emitting layer, an electron transport layer, an electron injection layer, and a cathode sequentially provided on a substrate, thereby achieving high efficiency and durability.

[0003] 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 an element with excellent carrier balance. Specifically, the use of a material with high hole injection properties (supplying holes injected from the anode to the light-emitting layer) and high electron blocking properties (blocking electrons injected from the cathode) can improve the probability of holes and electrons recombining in the light-emitting layer. Furthermore, high luminous efficiency can be achieved by confining excitons generated in the light-emitting layer. Therefore, the role of 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.

[0004] Furthermore, the heat resistance and amorphous nature of the material are also important factors in determining the lifespan of the element. In other words, materials with low heat resistance are susceptible to thermal decomposition even at low temperatures due to the heat generated when the element is in operation, leading to material degradation. Materials with low amorphous nature can undergo thin film crystallization even in a short period of time, leading to element degradation. Therefore, the materials used must have not only high heat resistance but also excellent amorphous nature.

[0005] Known hole-transport materials used in organic EL devices to date include N,N'-diphenyl-N,N'-di(α-naphthyl)benzidine (NPD) and various aromatic amine derivatives. However, while NPD has good hole-transporting capabilities, its glass transition temperature (Tg), an indicator of heat resistance, is as low as 96°C, and crystallization occurs under high-temperature conditions, resulting in a deterioration of device characteristics (see Non-Patent Document 1). Furthermore, while some aromatic amine derivatives have excellent hole mobility, their electron-blocking properties are insufficient, resulting in some electrons passing through the light-emitting layer, making it difficult to expect improvements in luminous efficiency.

[0006] In view of this, substituted carbazole compounds and arylamine compounds have been proposed as compounds with improved properties such as heat resistance and hole injection properties (see Patent Documents 1 and 2). However, in devices using these compounds in the hole injection layer or hole transport layer, although the device life and luminous efficiency have been improved, they are still not sufficient, and further reduction in driving voltage, improvement in luminous efficiency, and extension of device life are required.

[0007] Patent Document 1: JP 2009-076817 A, International Publication No. 2016 / 006629, European Patent Application Publication No. 2684932, Korean Patent Publication No. 10-2020-0131929

[0008] Proceedings of the 3rd regular meeting of the Organic EL Discussion Group, 2006, p. 13-14 Chem. Rev. , 2016, Vol. 116, p. 12564-12649Appl. Phys. Let. , 2011, Vol. 98, No. 8,083302

[0009] The present invention aims to provide an arylamine compound as a material for an organic EL device having high efficiency and durability, which has excellent hole injection and transport properties, excellent electron blocking ability, high stability in a thin film state, and excellent durability. Another object of the present invention is to provide an organic EL device and an electronic device using the arylamine compound, which have high luminous efficiency and power efficiency, low light-emission onset voltage and low practical driving voltage, and long life.

[0010] In order to achieve the above-mentioned object, the present inventors focused on the advantages of arylamine compounds, such as excellent hole injection and transport capabilities, as well as excellent thin-film stability and durability. They then discovered that by introducing a substituted naphthylene group into an arylamine compound and optimizing the substitution position and number of substituents on the substituted naphthylene group, the properties of the material can be dramatically improved. They also discovered that organic EL devices using such arylamine compounds have improved luminous efficiency and power efficiency, enable suppression of the light-emission onset voltage and practical driving voltage, and achieve a lifetime that exceeds that of conventional devices, thereby completing the present invention. Specifically, the present invention is summarized as follows:

[0011] 1) An arylamine compound represented by the following general formula (I):

[0012]

[0013] In general formula (I), Ar １ and Ar ２ each independently represents a substituted or unsubstituted aryl group or a substituted or unsubstituted heteroaryl group; L １ ~L ３ each independently represents a single bond, a substituted or unsubstituted arylene group, or a substituted or unsubstituted heteroarylene group, and A represents a naphthyl group represented by the following general formula (II), which may be substituted with a deuterium atom:

[0014]

[0015] In general formula (II), R represents a substituted or unsubstituted aryl group or a substituted or unsubstituted heteroaryl group, n represents an integer of 2 or 3, and a plurality of R may be the same or different; ３ is as defined in the general formula (I) above.

[0016] 2) The arylamine compound according to 1), wherein in the general formula (II), n is 2. 3) In the general formula (I), L １ is a single bond, and Ar １ is a deuterium-substituted or unsubstituted aryl group or a deuterium-substituted or unsubstituted heteroaryl group, and A is a naphthyl group optionally substituted with a deuterium atom and selected from the group consisting of the following general formulae (II-A-8) to (II-A-14):

[0017]

[0018] L in general formulae (II-A-8) to (II-A-14) ３ and R is as defined in the general formula (I) and the general formula (II).

[0019] 4) In the general formula (I), L ３ is a deuterium-substituted or unsubstituted phenylene group, a deuterium-substituted or unsubstituted biphenyldiyl group, or a deuterium-substituted or unsubstituted naphthylene group. １is a deuterium-substituted or unsubstituted phenyl group, a deuterium-substituted or unsubstituted biphenylyl group, a deuterium-substituted or unsubstituted terphenylyl group, a deuterium-substituted or unsubstituted naphthyl group, a deuterium-substituted or unsubstituted phenanthryl group, or a deuterium-substituted or unsubstituted dibenzofuranyl group. 6) The arylamine compound according to any one of 3) to 5), wherein, in general formula (II), R is a deuterium-substituted or unsubstituted phenyl group, a deuterium-substituted or unsubstituted biphenylyl group, a deuterium-substituted or unsubstituted naphthyl group, a deuterium-substituted or unsubstituted phenanthryl group, or a deuterium-substituted or unsubstituted dibenzofuranyl group. 7) The arylamine compound according to any one of 3) to 6), wherein, in general formula (II), R is a deuterium-substituted or unsubstituted phenyl group. 8) The arylamine compound according to 1), wherein, in the general formula (I), A is a naphthyl group selected from the group consisting of the following general formulae (II-A-1) to (II-A-7), which may be substituted with a deuterium atom:

[0020]

[0021] L in general formulae (II-A-1) to (II-A-7) ３ and R is as defined in the general formula (I) and the general formula (II).

[0022] 9) The arylamine compound according to 8), wherein in the general formulae (II-A-1) to (II-A-7), R is a deuterium-substituted or unsubstituted phenyl group, a deuterium-substituted or unsubstituted biphenylyl group, a deuterium-substituted or unsubstituted naphthyl group, a deuterium-substituted or unsubstituted phenanthryl group, or a deuterium-substituted or unsubstituted dibenzofuranyl group. ３ is a single bond, a deuterium-substituted or unsubstituted phenylene group, a deuterium-substituted or unsubstituted biphenyldiyl group, or a deuterium-substituted or unsubstituted naphthylene group. １is a substituted or unsubstituted phenyl group, a substituted or unsubstituted biphenylyl group, a substituted or unsubstituted terphenylyl group, a substituted or unsubstituted naphthyl group, a substituted or unsubstituted phenanthryl group, or a substituted or unsubstituted dibenzofuranyl group. 12) The arylamine compound according to any one of 8) to 11), wherein, in general formula (I), A is a naphthyl group selected from the group consisting of general formulas (II-A-1) to (II-A-3). 13) The arylamine compound according to any one of general formula (I), wherein Ar １ is a deuterium-substituted or unsubstituted phenyl group, a deuterium-substituted or unsubstituted biphenylyl group, a deuterium-substituted or unsubstituted terphenylyl group, a deuterium-substituted or unsubstituted naphthyl group, a deuterium-substituted or unsubstituted phenanthryl group, or a deuterium-substituted or unsubstituted dibenzofuranyl group. 14) The arylamine compound according to any one of 8) to 13), wherein in general formulas (II-A-1) to (II-A-3), R is a deuterium-substituted or unsubstituted phenyl group. 15) An organic electroluminescence device having a pair of electrodes and at least one organic layer sandwiched between the electrodes, wherein the organic layer contains the arylamine compound according to any one of 1) to 14). 16) The organic electroluminescence device according to 15), wherein the organic layer containing the arylamine compound is at least one layer selected from a hole-injection layer, a hole-transport layer, an electron-blocking layer, and an emitting layer. 17) An electronic device having a pair of electrodes and at least one organic layer sandwiched between the electrodes, wherein the organic layer contains the arylamine compound according to any one of 1) to 14).

[0023] According to the present invention, an arylamine compound is obtained which is a material for an organic EL device having high efficiency and durability, and which has excellent hole injection and transport properties, excellent electron blocking ability, high stability in a thin film state, and excellent durability. Furthermore, according to the present invention, by using the arylamine compound, an organic EL device and an electronic device having high luminous efficiency and power efficiency, low light-emission onset voltage and low practical driving voltage, and long life can be obtained.

[0024] The arylamine compound of the present invention has excellent hole injection and transport properties, and excellent thin film stability and durability. Therefore, in an organic EL device using the compound as a hole injection material and / or hole transport material, the hole transport efficiency to the light-emitting layer is improved, the light-emitting efficiency is improved, and the driving voltage is reduced, thereby improving the durability of the device and achieving characteristics of high efficiency, low driving voltage, and long life.

[0025] The arylamine compound of the present invention has excellent electron blocking ability, high electron resistance, and is stable even in a thin film state, and has excellent ability to confine excitons generated in the light-emitting layer. Therefore, in an organic EL device using the compound as an electron blocking material, the probability of hole-electron recombination is improved and thermal deactivation is suppressed. As a result, the luminous efficiency is increased, the driving voltage is reduced, and current resistance is improved, thereby improving the maximum luminance.

[0026] The arylamine compound of the present invention has excellent hole-transporting properties and a wide band gap. Therefore, an organic EL device using the compound as a host material in an emitting layer can have a reduced driving voltage and improved luminous efficiency by carrying a dopant (fluorescent emitter, phosphorescent emitter, or delayed fluorescent emitter).

[0027] As described above, the arylamine compound of the present invention is useful as a material for constituting a layer selected from a hole injection layer, a hole transport layer, an electron blocking layer, and an emitting layer of an organic EL device. Furthermore, an organic EL device using the arylamine compound can improve the luminous efficiency, driving voltage, and durability of conventional organic EL devices. Furthermore, the arylamine compound of the present invention can also be used in the field of electronic devices such as electrophotographic photoreceptors, image sensors, photoelectric conversion elements, and solar cells.

[0028] FIG. 1 is a diagram showing a specific example of an arylamine compound represented by general formula (I). FIG. 2 is a diagram showing a specific example of an arylamine compound represented by general formula (I). FIG. 3 is a diagram showing a specific example of an arylamine compound represented by general formula (I). FIG. 4 is a diagram showing a specific example of an arylamine compound represented by general formula (I). FIG. 5 is a diagram showing a specific example of an arylamine compound represented by general formula (I). FIG. 6 is a diagram showing a specific example of an arylamine compound represented by general formula (I). FIG. 7 is a diagram showing a specific example of an arylamine compound represented by general formula (I). FIG. 8 is a diagram showing a specific example of an arylamine compound represented by general formula (I). FIG. 9 is a diagram showing a specific example of an arylamine compound represented by general formula (I). FIG. 10 is a diagram showing a specific example of an arylamine compound represented by general formula (I). FIG. 11 is a diagram showing a specific example of an arylamine compound represented by general formula (I). FIG. 12 is a diagram showing a specific example of an arylamine compound represented by general formula (I). FIG. 13 is a diagram showing a specific example of an arylamine compound represented by general formula (I).

[0029] Hereinafter, embodiments of the present invention will be described in detail. 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 ​​written before and after "to" as the lower and upper limits. Furthermore, when a numerical range is described in stages, the upper and lower limits of each numerical range and the numerical values ​​described in the examples can be arbitrarily combined to form a new numerical range.

[0030] The isotopes of hydrogen atoms present in the molecules of the compounds used in the present invention are not particularly limited. For example, all hydrogen atoms in the molecule may be １ H, or part or all of ２ H (deuterium D). In this specification, the term "substituted or unsubstituted" means that the group to which the term is attached may be an unsubstituted group (a group in which a hydrogen atom is not substituted with a substituent), or at least one hydrogen atom of the group to which the term is attached may be substituted with a substituent. The term "deuterium-substituted or unsubstituted" means that the group to which the term is attached may be an unsubstituted group (a group in which a hydrogen atom is not substituted with a substituent), or at least one hydrogen atom of the group to which the term is attached may be a deuterium atom ( ２ However, as described above, the hydrogen atoms present in the molecules of the compounds used in the present invention may be １ Even if it's H ２ H (deuterium D). Therefore, the term "deuterium substituted" in "deuterium substituted or unsubstituted" is used with caution to indicate that the term "unsubstituted" does not exclude the embodiment in which the hydrogen atom is a "deuterium atom."

[0031] As used herein, "organic compound" refers to a compound containing one or more carbon atoms, and "organic layer" refers to a layer containing 70% by mass or more of an organic compound. Examples of organic compounds that can be used include those consisting only of atoms selected from the group consisting of carbon atoms, hydrogen atoms, nitrogen atoms, oxygen atoms, sulfur atoms, boron atoms, and halogen atoms. As used herein, "transparent" refers to a visible light transmittance of 50% or more, and the visible light transmittance is, for example, 80% or more, for example, 90% or more, or for example, 99% or more. The visible light transmittance can be measured using an ultraviolet-visible spectrophotometer.

[0032] <Arylamine Compound> The arylamine compound of the present invention is a compound represented by the above general formula (I). １ and Ar ２each independently represents a substituted or unsubstituted aryl group or a substituted or unsubstituted heteroaryl group. １ ~L ３ Each independently represents a single bond, a substituted or unsubstituted arylene group, or a substituted or unsubstituted heteroarylene group. A represents a naphthyl group represented by the above general formula (II), which may be substituted with a deuterium atom. In general formula (II), R represents a substituted or unsubstituted aryl group or a substituted or unsubstituted heteroaryl group. n represents an integer of 2 or 3, and multiple Rs may be the same or different. Note that, L in general formula (II) ３ represents L in general formula (I). ３ and means a group to which A (a naphthyl group represented by general formula (II)) in general formula (I) is linked. １ , L ２ , and L ３ is a single bond, １ , Ar ２ and A are each directly bonded to the nitrogen atom (N) shown in general formula (I).

[0033] Ar in general formula (I) １ and Ar ２The aromatic ring constituting the "aryl group" in the "substituted or unsubstituted aryl group" represented by R in general formula (II) may be a monocyclic ring or a fused ring in which two or more rings are fused, or may be a linked ring in which two or more rings are linked via a single bond, or a spiro ring in which two or more rings are linked via a spiro bond. When the aromatic ring is a fused ring, the number of fused rings is, for example, 2 to 6, preferably 2 to 4. When the aromatic ring is a linked ring, the number of linked rings is, for example, 2 to 6, preferably 2 to 4. The number of carbon atoms constituting the aromatic ring (hereinafter also simply referred to as "number of carbon atoms") is, for example, 6 to 30, for example, 6 to 22, for example, 6 to 20, for example, 6 to 18, for example, 6 to 14, for example, 6 to 12, or for example, 6 to 10. Specific examples of the "aryl group" include aryl groups having 6 to 30 carbon atoms, such as a phenyl group, a biphenylyl group, a terphenylyl group, a naphthyl group, an anthryl group, a phenanthryl group, an indenyl group, a pyrenyl group, a perylenyl group, a fluoranthenyl group, a triphenylenyl group, a fluorenyl group, and a spirobifluorenyl group.

[0034] Ar in general formula (I) １ and Ar ２and the aromatic heterocycle constituting the "heteroaryl group" in the "substituted or unsubstituted heteroaryl group" represented by R in general formula (II) may be a single ring or a fused ring in which two or more rings are fused. When the aromatic heterocycle is a fused ring, the number of fused rings is, for example, 2 to 6, and preferably 2 to 4. Examples of heteroatoms constituting the aromatic heterocycle include a nitrogen atom, an oxygen atom, and a sulfur atom. The number of carbon atoms constituting the aromatic heterocycle (hereinafter also simply referred to as "number of carbon atoms") is, for example, 2 to 30, for example, 2 to 18, for example, 2 to 12. Specific examples of the "heteroaryl group" include heteroaryl groups having 2 to 30 carbon atoms, such as a pyridyl group, a pyrimidinyl group, a triazinyl group, a furyl group, a pyrrolyl group, a thienyl group, a quinolyl group, an isoquinolyl group, a benzofuranyl group, a benzothienyl group, an indolyl group, a carbazolyl group, a benzoxazolyl group, a benzothiazolyl group, an imidazopyridyl group, an oxazolopyridyl group, an oxazolopyrazyl group, a quinoxalinyl group, a quinazolinyl group, a benzimidazolyl group, a pyrazolyl group, a dibenzofuranyl group, a naphthobenzofuranyl group, a dibenzothienyl group, a naphthyridinyl group, a phenanthrolinyl group, an acridinyl group, and a carbolinyl group.

[0035] L in general formula (I) １ ~L ３ The "arylene group" or "heteroarylene group" in the "substituted or unsubstituted arylene group" or "substituted or unsubstituted heteroarylene group" represented by the following formula (I) has the same meaning as the "divalent aromatic hydrocarbon group" or "divalent aromatic heterocyclic group", respectively. That is, the "arylene group" or "heteroarylene group" is defined as a divalent aromatic hydrocarbon group or a divalent aromatic heterocyclic group. １ , Ar ２and divalent aromatic hydrocarbon groups or aromatic heterocyclic groups in which one hydrogen atom has been removed from the specific groups exemplified as the "aryl group" or "heteroaryl group" represented by R. The number of carbon atoms in the aromatic ring constituting the "arylene group" is, for example, 6 to 30, for example, 6 to 22, for example, 6 to 20, for example, 6 to 18, for example, 6 to 14, for example, 6 to 12, or for example, 6 to 10. The number of carbon atoms in the aromatic heterocyclic ring constituting the "heteroarylene group" is, for example, 2 to 30, for example, 2 to 18, or for example, 2 to 12.

[0036] Ar in general formula (I) １ and Ar ２and the "substituent" in the "substituted aryl group" or "substituted heteroaryl group" represented by R in general formula (II) can include the following: a deuterium atom, a cyano group, and a nitro group; halogen atoms such as a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom; silyl groups such as a trimethylsilyl group and a triphenylsilyl group; linear or branched alkyl groups having 1 to 6 carbon atoms such as a methyl group, an ethyl group, and a propyl group; linear or branched alkyloxy groups having 1 to 6 carbon atoms such as a methoxy group, an ethoxy group, and a propoxy group; alkenyl groups such as a vinyl group and an allyl group; aryl groups having 6 to 30 carbon atoms such as a phenyl group, a biphenylyl group, a terphenylyl group, a naphthyl group, an anthryl group, a phenanthryl group, an indenyl group, a pyrenyl group, a perylenyl group, a fluoranthenyl group, a triphenylenyl group, a fluorenyl group, and a spirobifluorenyl group; heteroaryl groups having 2 to 30 carbon atoms such as a pyridyl group, a pyrimidinyl group, a triazinyl group, a furyl group, a pyrrolyl group, a thienyl group, a quinolyl group, an isoquinolyl group, a benzofuranyl group, a benzothienyl group, an indolyl group, a carbazolyl group, a benzoxazolyl group, a benzothiazolyl group, an imidazopyridyl group, an oxazolopyridyl group, an oxazolopyrazyl group, a quinoxalinyl group, a quinazolinyl group, a benzimidazolyl group, a pyrazolyl group, a dibenzofuranyl group, a naphthobenzofuranyl group, a dibenzothienyl group, a naphthyridinyl group, a phenanthrolinyl group, an acridinyl group, and a carbolinyl group; aryloxy groups such as a phenyloxy group, a tolyloxy group, a biphenylyloxy group, and a naphthyloxy group; and aralkyloxy groups such as a benzyloxy group and a phenethyloxy group. The hydrogen atoms of these substituents may be further substituted with the substituents exemplified herein. Regarding a substituent further substituted with a substituent, the substituent directly substituted on the parent skeleton (aromatic hydrocarbon group or aromatic heterocyclic group) may be referred to as the "first substituent," and the substituent substituted on the first substituent may be referred to as the "second substituent." Here, when the first substituent contains a benzene ring, the benzene ring may be bonded to the parent skeleton to form a cyclic structure.Furthermore, when two or more second substituents are substituted on the benzene ring of the first substituent, adjacent second substituents may be bonded to each other to form a cyclic structure. The bond between the benzene ring and the parent skeleton in the first substituent, and the bond between the second substituents may be a single bond or a bond via a linking group. Examples of the linking group include a substituted or unsubstituted methylene group, an oxygen atom, and a sulfur atom. Preferred substituents for the first substituent and the second substituent include a deuterium atom, a linear or branched alkyl group having 1 to 6 carbon atoms, and an aryl group having 6 to 20 carbon atoms constituting an aromatic ring.

[0037] L in general formula (I) １ ~L ３ The "substituent" in the "substituted arylene group" or "substituted heteroarylene group" represented by the formula: １ , Ar ２ and the same as those exemplified as the "substituent" in the "substituted aryl group" or "substituted heteroaryl group" represented by R. The possible embodiments of the substituent are also the same.

[0038] In general formula (I), Ar １ and Ar ２is preferably a substituted or unsubstituted aryl group having 6 to 30 carbon atoms or a substituted or unsubstituted heteroaryl group having 2 to 30 carbon atoms, and more preferably a substituted or unsubstituted aryl group having 6 to 12 carbon atoms or a substituted or unsubstituted heteroaryl group having 2 to 12 carbon atoms. In the "substituted or unsubstituted aryl group having 6 to 30 carbon atoms" or "substituted or unsubstituted heteroaryl group having 2 to 30 carbon atoms", the "aryl group having 6 to 30 carbon atoms" or "heteroaryl group having 2 to 30 carbon atoms" is preferably a phenyl group, a biphenylyl group, a terphenylyl group, a naphthyl group, a phenanthryl group, a spirobifluorenyl group, a carbazolyl group, a dibenzofuranyl group, or a naphthobenzofuranyl group, more preferably a phenyl group, a biphenylyl group, a terphenylyl group, a naphthyl group, a phenanthryl group, or a dibenzofuranyl group, and even more preferably a phenyl group, a biphenylyl group, a naphthyl group, or a dibenzofuranyl group. It is preferable that the "substituted or unsubstituted aryl group having 6 to 30 carbon atoms" or the "substituted or unsubstituted heteroaryl group having 2 to 30 carbon atoms" is deuterium-substituted or unsubstituted. That is, Ar １ and Ar ２ is preferably a substituted or unsubstituted phenyl group, biphenylyl group, terphenylyl group, naphthyl group, phenanthryl group, spirobifluorenyl group, carbazolyl group, dibenzofuranyl group, or naphthobenzofuranyl group, more preferably a substituted or unsubstituted phenyl group, biphenylyl group, terphenylyl group, naphthyl group, phenanthryl group, or dibenzofuranyl group, and even more preferably a substituted or unsubstituted phenyl group, biphenylyl group, naphthyl group, or dibenzofuranyl group. Furthermore, these aryl groups or heteroaryl groups are preferably deuterium-substituted or unsubstituted. In addition, Ar １ and Ar ２At least one of the groups is preferably a substituted or unsubstituted aryl group, more preferably a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, still more preferably a substituted or unsubstituted aryl group having 6 to 12 carbon atoms, and particularly preferably a deuterium-substituted or unsubstituted aryl group having 6 to 12 carbon atoms.

[0039] In general formula (I), L １ and L ２ is preferably a single bond or a substituted or unsubstituted arylene group having 6 to 20 carbon atoms, more preferably a single bond or a deuterium-substituted or unsubstituted arylene group having 6 to 20 carbon atoms, and even more preferably a single bond or a deuterium-substituted or unsubstituted arylene group having 6 to 12 carbon atoms. As the "arylene group having 6 to 20 carbon atoms" in the "deuterium-substituted or unsubstituted arylene group having 6 to 20 carbon atoms", a phenylene group or a biphenyldiyl group is preferred, a phenylene group is more preferred, and a 1,4-phenylene group is particularly preferred. １ and L ２ At least one of L is preferably a single bond. １ is a single bond, Ar １ is preferably a deuterated or unsubstituted aryl group or a deuterated or unsubstituted heteroaryl group, and L ２ is a single bond, Ar ２ is preferably a deuterated or unsubstituted aryl group or a deuterated or unsubstituted heteroaryl group.

[0040] In general formula (I), L ３is preferably a single bond or a substituted or unsubstituted arylene group having 6 to 30 carbon atoms, more preferably a single bond or a deuterium-substituted or unsubstituted arylene group having 6 to 30 carbon atoms, even more preferably a single bond or a deuterium-substituted or unsubstituted arylene group having 6 to 12 carbon atoms, and particularly preferably a deuterium-substituted or unsubstituted arylene group having 6 to 12 carbon atoms. As the "arylene group having 6 to 30 carbon atoms" in the "deuterium-substituted or unsubstituted arylene group having 6 to 30 carbon atoms", a phenylene group, a biphenyldiyl group, or a naphthylene group is preferred, a phenylene group or a biphenyldiyl group is more preferred, a phenylene group is even more preferred, and a 1,4-phenylene group is particularly preferred.

[0041] In the general formula (I), A is L ３ is preferably a 2-naphthyl group bonded to the 2-position of the naphthalene ring. Furthermore, in general formula (II), n is 2 or 3, preferably 2. The naphthyl group represented by A is preferably a di- or tri-substituted 2-naphthyl group selected from the group consisting of general formulae (II-A-1) to (II-A-7), the group consisting of general formulae (II-A-8) to (II-A-14), or the group consisting of general formulae (II-A-1) to (II-A-14), more preferably a di-substituted 2-naphthyl group selected from the group consisting of general formulae (II-A-1) to (II-A-3) and general formulae (II-A-8) to (II-A-14), and even more preferably a di-substituted 2-naphthyl group selected from the group consisting of general formulae (II-A-1) to (II-A-3), general formula (II-A-8), and general formula (II-A-11).

[0042] In particular, when A is a naphthyl group selected from the group consisting of the general formulae (II-A-8) to (II-A-14), L １ and L ２ At least one of L is preferably a single bond. １ and L ２ It is more preferable that one of L is a single bond and the other is other than a single bond. １ and L ２ When one of the groups is a single bond and the other is not a single bond, L１ or L ２ Ar bonded to １ or Ar ２ is preferably a deuterium-substituted or unsubstituted aryl group or a deuterium-substituted or unsubstituted heteroaryl group. １ is a single bond, and Ar １ is a deuterated or unsubstituted aryl group or a deuterated or unsubstituted heteroaryl group, or L ２ is a single bond, and Ar ２ is preferably a deuterated or unsubstituted aryl group or a deuterated or unsubstituted heteroaryl group, and in the former case, L ２ is preferably not a single bond, and in the latter case, L １ is preferably not a single bond.

[0043] In general formula (II), R is preferably a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, more preferably a substituted or unsubstituted aryl group having 6 to 12 carbon atoms, and even more preferably a deuterium-substituted or unsubstituted aryl group having 6 to 12 carbon atoms. The "aryl group having 6 to 30 carbon atoms" in the "substituted or unsubstituted aryl group having 6 to 30 carbon atoms" is preferably a phenyl group, biphenylyl group, naphthyl group, phenanthryl group, or dibenzofuranyl group, more preferably a phenyl group, biphenylyl group, naphthyl group, or phenanthryl group, and even more preferably a phenyl group. That is, R is particularly preferably a deuterium-substituted or unsubstituted phenyl group.

[0044] The arylamine compounds of the present invention represented by general formula (I) are novel compounds, but these compounds can be synthesized according to known methods (see, for example, Non-Patent Document 2).

[0045] Among the arylamine compounds represented by general formula (I), specific examples of preferred compounds are shown in Figures 1 to 12, but the present invention is not limited to these compounds. As described above, in the arylamine compounds represented by general formula (I), all hydrogen atoms in the molecule are１ H, and some or all of the hydrogen atoms ２ Therefore, in FIGS. 1 to 12, some or all of the hydrogen atoms in the molecule may be H(D). ２ Compounds that are H(D) are also shown, but they are ２ This shows an example of a substitution mode of H(D), ２ The substitution pattern of H(D) is not limited to that shown in the figure.

[0046] The method for purifying the arylamine compound represented by general formula (I) is not particularly limited, and any known method used for purifying organic compounds can be used, such as purification by column chromatography, adsorption purification using silica gel, activated carbon, activated clay, etc., recrystallization purification or crystallization purification using a solvent, sublimation purification, etc. The compound can be identified by NMR analysis.

[0047] As physical property values ​​of the arylamine compound represented by general formula (I), it is preferable to measure the melting point, glass transition point (Tg), and work function. The melting point serves as an indicator of vapor deposition property, and the glass transition point serves as an indicator of the stability of the thin film state. The melting point and glass transition point can be measured for a powder of the compound using a high-sensitivity differential scanning calorimeter (manufactured by Bruker AXS, product name: DSC3100SA). The work function serves as an indicator of hole injection property, hole transport property, and electron blocking property. The work function can be measured for a thin film (100 nm) of the compound prepared on an ITO substrate using an ionization potential measurement device (manufactured by Sumitomo Heavy Industries, Ltd., product name: PYS-202).

[0048] <Organic EL Devices and Electronic Devices> The arylamine compound of the present invention represented by general formula (I) can be suitably used in organic EL devices. Specifically, the arylamine compound of the present invention is preferably used as a material constituting a layer selected from a hole injection layer, a hole transport layer, an electron blocking layer, and an emitting layer of an organic EL device, and more preferably as a material constituting a layer selected from a hole transport layer and an electron blocking layer. Furthermore, the arylamine compound of the present invention can be suitably used as a material constituting the organic layer in an electronic device having a pair of electrodes and at least one organic layer sandwiched between the electrodes.

[0049] [Organic EL Element] Figure 13 is a schematic diagram showing the structure of an organic EL element according to one embodiment of the present invention. Examples of the structure of an organic EL element include, for example, a top-emission light-emitting element having a glass substrate 1 on which an anode 2, a hole transport layer 4, an emitting layer 6, an electron transport layer 7, a cathode 9, and a capping layer 10 are sequentially stacked. Examples of organic EL element structures include a hole injection layer 3 between the anode and the hole transport layer, an electron blocking layer 5 between the hole transport layer and the emitting layer, a hole blocking layer (not shown) between the emitting layer and the electron transport layer, and an electron injection layer 8 between the electron transport layer and the cathode. In these multilayer structures, one organic layer can serve multiple roles. For example, the organic EL element may function as both a hole injection layer and a hole transport layer, a hole transport layer and an electron blocking layer, a hole blocking layer and an electron transport layer, or an electron transport layer and an electron injection layer. It is also possible to use a structure in which two or more organic layers having the same function are stacked, and examples thereof include a structure in which two hole transport layers are stacked, a structure in which two light-emitting layers are stacked, a structure in which two electron transport layers are stacked, and a structure in which two capping layers are stacked.

[0050] The total thickness of the layers constituting the organic EL element is preferably 200 nm to 750 nm, more preferably 350 nm to 600 nm. The thickness of the capping layer is preferably, for example, 30 nm to 120 nm, more preferably 40 nm to 80 nm. When the organic EL element has such a thickness, good light extraction efficiency can be obtained. The thickness of the capping layer can be appropriately changed depending on the type of light-emitting material used in the light-emitting element, the thickness of each layer other than the capping layer, and the like.

[0051] (Substrate) The substrate is not particularly limited, and may be a glass substrate, a plastic substrate, etc. The substrate may be transparent or opaque. Examples of substrates include plastic substrates such as polyethylene terephthalate, polyethylene naphthalate, polyethylene, polypropylene, cellophane, cellulose diacetate, cellulose triacetate, cellulose acetate butyrate, cellulose acetate propionate, cellulose acetate phthalate, cellulose nitrate, polyvinylidene chloride, polyvinyl alcohol, polyethylene vinyl alcohol, syndiotactic polystyrene, polycarbonate, norbornene resin, polymethylpentene, polyether ketone, polyimide, polyether sulfone, polyphenylene sulfide, polysulfones, polyether imide, polyether ketone imide, polyamide, fluororesin, nylon, polymethyl methacrylate, acrylic or polyarylate, and organic-inorganic hybrid resins; inorganic substrates such as glass, quartz, aluminum oxide, silicon, silicon oxide, tantalum dioxide, tantalum pentoxide, and indium tin oxide; and metal substrates such as gold, copper, chromium, titanium, and aluminum. Among these, glass substrates and polyimide substrates, which have excellent heat resistance, are preferred from the viewpoint of transistor formation.

[0052] (Anode) For the anode, an electrode material with a large work function, such as ITO or gold, is used.

[0053] (Hole Injection Layer and Hole Transport Layer) The arylamine compound of the present invention represented by general formula (I) can be used as a material for the hole injection layer and the hole transport layer. Other examples of materials for the hole injection layer include arylamine compounds having only one triphenylamine structure per molecule. Other examples include porphyrin compounds such as copper phthalocyanine, starburst triphenylamine derivatives, arylamine compounds having two or more triphenylamine structures or carbazolyl structures per molecule, each linked by a single bond or a divalent group not containing a heteroatom, acceptor heterocyclic compounds such as hexacyanoazatriphenylene, and coating-type polymer materials. Thin films using these materials can be formed by known methods such as vapor deposition, spin coating, and inkjet printing.

[0054] As materials for the hole injection layer and hole transport layer, in addition to the arylamine compound represented by general formula (I) of the present invention, it is preferable to use an arylamine compound having only one triphenylamine structure in the molecule. Also usable are 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 of which is linked by a single bond or a divalent group containing no heteroatom. These materials may be used alone or in combination to form a film, or each may be used as a single layer. Alternatively, the hole injection layer and the hole transport layer may be formed using a single material, a laminated structure of layers formed using a mixture of multiple materials, or a laminated structure of layers formed using a single material and a layer formed using a mixture of multiple materials. Coating-type polymer materials such as poly(3,4-ethylenedioxythiophene) (PEDOT) / poly(styrene sulfonate) (PSS) can be used as materials for the hole injection layer and the hole transport layer. Thin films formed using these materials can be formed using known methods such as vapor deposition, spin coating, and inkjet printing.

[0055] Furthermore, in the hole injection layer or hole transport layer, materials typically used for these layers may be doped with P, such as trisbromophenylaminehexachloroantimony or a radialene derivative (see, for example, Patent Document 3). Furthermore, polymer compounds having a benzidine derivative structure, such as TPD, as a partial structure may be used.

[0056] (Electron Blocking Layer) The arylamine compound of the present invention represented by general formula (I) is preferably used as the material for the electron blocking layer. Other materials that can be used for the electron blocking layer include carbazole derivatives such as 4,4',4''-tri(N-carbazolyl)triphenylamine (TCTA), 9,9-bis[4-(carbazol-9-yl)phenyl]fluorene, 1,3-bis(carbazol-9-yl)benzene (mCP), and 2,2-bis(4-carbazol-9-ylphenyl)adamantane (Ad-Cz); and compounds having a triphenylsilyl group and a triarylamine structure, such as 9-[4-(carbazol-9-yl)phenyl]-9-[4-(triphenylsilyl)phenyl]-9H-fluorene. These materials may also serve as materials for the hole transport layer. These materials may be used to form a film using one material alone or a mixture of two or more materials, or each may be used as a single layer. The thin film may be formed by a known method such as vapor deposition, spin coating, or ink jet printing.

[0057] (Light-emitting layer) As a material for the light-emitting layer, it is preferable to use the arylamine compound of the present invention represented by general formula (I). Other materials for the light-emitting layer include tris(8-quinolinolato)aluminum (Alq ３Metal complexes of quinolinol derivatives such as quinolinol derivatives (e.g., quinolinol derivatives), various metal complexes, anthracene derivatives, bisstyrylbenzene derivatives, pyrene derivatives, oxazole derivatives, and polyparaphenylenevinylene derivatives can be used. The light-emitting layer may also be composed of a host material and a dopant material. In this case, the arylamine compound of the present invention represented by general formula (1) or an anthracene derivative is preferably used as the host material. In addition to the light-emitting layer materials listed above, heterocyclic compounds having an indole ring as a fused ring partial structure, heterocyclic compounds having a carbazole ring as a fused ring partial structure, carbazole derivatives, thiazole derivatives, benzimidazole derivatives, and polydialkylfluorene derivatives can also be used. Heterocyclic compounds having S, B, and N as ring constituent elements are preferably used as the dopant material. Other examples include quinacridone, coumarin, rubrene, perylene, and their derivatives, benzopyran derivatives, rhodamine derivatives, and aminostyryl derivatives. These materials may be used alone or in combination, or each may be used as a single layer. The material may also be used as a laminated structure consisting of layers formed from a single material selected from these materials, a laminated structure consisting of layers formed from a mixture of multiple materials, or a laminated structure consisting of a layer formed from a single material and a layer formed from a mixture of multiple materials. Thin film formation using these materials can be carried out by known methods such as vapor deposition, spin coating, and inkjet printing.

[0058] Furthermore, a phosphorescent emitter may be used as the light-emitting material. As the phosphorescent emitter, a phosphorescent emitter of a metal complex such as iridium or platinum can be used. As the phosphorescent emitter, for example, Ir(ppy) ３ green phosphorescent emitters such as FIrpic and FIr6, blue phosphorescent emitters such as Btp ２Examples of suitable host materials include red phosphorescent emitters such as Ir(acac). Examples of suitable host materials include carbazole derivatives such as 4,4'-di(N-carbazolyl)biphenyl (CBP), TCTA, and mCP, as well as the arylamine compounds of the present invention, which have hole-injecting and hole-transporting properties. Examples of suitable host materials include p-bis(triphenylsilyl)benzene (UGH2) and 2,2',2''-(1,3,5-phenylene)-tris(1-phenyl-1H-benzimidazole) (TPBI). By using such materials, high-performance organic EL devices can be fabricated. To avoid concentration quenching, the phosphorescent emitter is preferably doped into the host material by co-evaporation in a range of 1 to 30% by mass relative to the entire light-emitting layer.

[0059] 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). Thin films using these materials can be formed by known methods such as vapor deposition, spin coating, and ink-jet printing.

[0060] (Hole Blocking Layer) Materials for the hole blocking layer 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 transport layer. These materials may be formed as a single film, a mixture of multiple materials, or a single layer. Furthermore, a laminate structure of layers formed of a single material selected from these materials, a mixture of multiple materials, or a mixture of layers formed of a single material and a mixture of multiple materials may be used. Thin films using these materials can be formed by known methods, such as vapor deposition, spin coating, and inkjet printing.

[0061] (Electron Transport Layer) As the material for the electron transport layer, it is preferable to use a benzimidazole derivative, anthracene derivative, pyrimidine derivative, or triazine derivative. ３ Examples of materials that can be used include metal complexes of quinolinol derivatives such as BAlq, various metal complexes, triazole derivatives, oxadiazole derivatives, pyridine derivatives, thiadiazole derivatives, carbodiimide derivatives, quinoxaline derivatives, pyridoindole derivatives, phenanthroline derivatives, and silole derivatives. These materials may be used alone or in combination, or each may be used as a single layer. Furthermore, a laminate structure of layers formed from a single material selected from these materials, a laminate structure of layers formed from a mixture of multiple materials, or a laminate structure of layers formed from a single material and a mixture of multiple materials may be used. Thin films formed from these materials can be formed by known methods such as vapor deposition, spin coating, and inkjet printing.

[0062] (Electron Injection Layer) Materials for the electron injection layer include alkali metal salts such as lithium fluoride and cesium fluoride, alkaline earth metal salts such as magnesium fluoride, metal complexes of quinolinol derivatives such as lithium quinolinol, metal oxides such as aluminum oxide, and metals such as ytterbium (Yb), samarium (Sm), calcium (Ca), strontium (Sr), and cesium (Cs). The electron injection layer can be omitted by selecting the electron transport layer and the cathode appropriately.

[0063] 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.

[0064] (Cathode) For the cathode, metals with low work functions such as aluminum and alloys with even lower work functions such as magnesium-silver alloys, magnesium-indium alloys, and aluminum-magnesium alloys are used.

[0065] (Capping Layer) As the material for the capping layer, a monoamine derivative, a diamine derivative, or a carbazolyl derivative having a benzoazole structure such as a benzoxazolyl group or a benzothiazolyl group is preferred. These materials may be used to form a film of one material alone, or a mixture of multiple materials, or each may be used as a single layer. Furthermore, a laminate structure may be formed in which layers formed of one material alone, layers formed of multiple materials mixed together, or layers formed of one material alone and layers formed of multiple materials mixed together. Thin film formation using these materials can be carried out by known methods such as vapor deposition, spin coating, and inkjet printing.

[0066] Although the organic EL element having a top emission structure has been described above, the present invention is not limited to this and can be similarly applied to an organic EL element having a bottom emission structure and an organic EL element having a dual emission structure that emits light from both the top and bottom. In organic EL elements having either structure, it is preferable that the electrode in the direction in which light is extracted from the light-emitting element to the outside be transparent or semi-transparent.

[0067] Hereinafter, the embodiments of the present invention will be specifically explained by way of examples, but the present invention is not limited to the following examples as long as it does not deviate from the gist of the invention. The reagents used in the examples are manufactured by Tokyo Chemical Industry Co., Ltd., Sigma-Aldrich, Alfa Aesar, etc. All reactions for synthesizing the compounds according to the present invention were carried out under a nitrogen gas flow using a reaction vessel equipped with a condenser, a stirrer, and a thermometer. The compounds in the examples were identified by １ H-NMR analysis (Bruker nuclear magnetic resonance apparatus, model: Ascend ＴＭ The measurement was performed using a frequency of 400 MHz.

[0068] Example 1 Synthesis of Compound (A-28) 8.0 g of N-phenyl-4-(7,8-diphenyl-2-naphthalenylbenzenamine), 5.6 g of 4-bromo-(2-naphthalenyl)benzene, 2.6 g of sodium tert-butoxide, 0.3 g of tris(dibenzylideneacetone)palladium(0), 0.2 g of Sphos (2-dicyclohexylphosphino-2',6'-dimethoxybiphenyl), and 80 mL of toluene were placed in a reaction vessel and stirred overnight under reflux. After confirming the completion of the reaction, 80 mL of toluene and 4.5 g of silica gel were added to the mixture, followed by stirring at 90°C for 30 minutes. Subsequently, the resulting reaction mixture was filtered through Celite at the same temperature. The resulting filtrate was concentrated and then purified by column chromatography (carrier: silica gel, eluent: dichloromethane / n-heptane) to obtain a crude product. The obtained crude product was purified by crystallization using a mixed solvent of tetrahydrofuran / ethyl acetate to obtain 5.7 g of compound (A-28) (yield: 49.1%, white powder).

[0069]

[0070] Regarding compound (A-28) １ H-NMR analysis (DMSO-d ６ ) was performed and the following 35 hydrogen signals were detected: δ (ppm) = 8.19 (1H), 8.12 (1H), 8.07 (1H), 8.00-7.93 (3H), 7.87 (2H), 7.78 (2H), 7.69 (1H), 7.58-7.49 (5H), 7.38-7.31 (5H), 7.26-7.12 (14H).

[0071] Example 2: Synthesis of Compound (A-34) To a reaction vessel were added 6.1 g of 6-(4-chlorophenyl)-1,4-diphenylnaphthalene, 8.0 g of 4-(2-naphthalenyl)-N-phenylbenzenamine, 3.9 g of tert-butoxysodium, 0.4 g of tris(dibenzylideneacetone)palladium(0), 0.2 g of tri-tert-butylphosphine, and 80 mL of xylene, followed by stirring overnight under reflux. After confirming the completion of the reaction, the reaction mixture was allowed to cool to room temperature. 80 mL of methanol was then added to the reaction mixture, and the resulting precipitate was collected by filtration to obtain a crude product. The resulting crude product was purified by crystallization using a tetrahydrofuran / ethyl acetate mixed solvent to obtain 7.2 g of Compound (A-34) (yield: 54.1%, white powder).

[0072]

[0073] Regarding compound (A-34) １ H-NMR analysis (DMSO-d ６ ) was performed and the following 35 hydrogen signals were detected: δ (ppm) = 8.19 (1H), 8.08 (1H), 8.00-7.93 (4H), 7.85 (2H), 7.78 (2H), 7.60-7.49 (16H), 7.37 (2H), 7.17-7.10 (7H).

[0074] Example 3 Synthesis of Compound (A-130) 9.0 g of N-phenyl-4-(4,8-diphenyl-2-naphthalenylbenzenamine), 5.0 g of 3-bromo-dibenzofuran, 3.9 g of sodium tert-butoxide, 0.4 g of tris(dibenzylideneacetone)palladium(0), 0.2 g of tri-tert-butylphosphine, and 90 mL of toluene were added to a reaction vessel and stirred overnight under reflux. After confirming the completion of the reaction, the reaction mixture was allowed to cool to room temperature. 90 mL of methanol was then added to the reaction mixture, and the resulting precipitate was collected by filtration to obtain a crude product. The resulting crude product was purified by crystallization using a tetrahydrofuran / ethyl acetate mixed solvent to obtain 10.0 g of compound (A-130) (yield: 81.0%, white powder).

[0075]

[0076] Regarding compound (A-130) １ H-NMR analysis (DMSO-d ６ ) was performed, and the following 31 hydrogen signals were detected: δ (ppm) = 8.25 (1H), 8.11 (3H), 7.93 (1H), 7.76 (1H), 7.72-7.57 (10H), 7.54-7.38 (8H), 7.33 (1H), 7.26 (4H), 7.22-7.16 (2H).

[0077] Example 4: Synthesis of compound (A-152) A reaction vessel was charged with 6-(4-chlorophenyl)-1,2-di(phenyl-d ５ 10.9 g of naphthalene, 8.0 g of 4-(2-naphthalenyl)-N-phenylbenzenamine, 3.1 g of sodium tert-butoxide, 0.5 g of tris(dibenzylideneacetone)palladium(0), 0.2 g of tri-tert-butylphosphine, and 80 mL of xylene were added and stirred overnight under reflux. After confirming the completion of the reaction, 80 mL of toluene and 4.5 g of silica gel were added to the reaction mixture, and the mixture was stirred at 90°C for 30 minutes. Subsequently, the resulting reaction mixture was filtered through Celite at the same temperature. The resulting filtrate was concentrated to obtain a crude product. The resulting crude product was purified by crystallization using a tetrahydrofuran / acetone mixed solvent to obtain 13.9 g of compound (A-152) (yield: 77.8%, white powder).

[0078]

[0079] Regarding compound (A-152) １ H-NMR analysis (DMSO-d ６ ) was performed, and the following 25 hydrogen signals were detected: δ (ppm) = 8.32 (1H), 8.21 (1H), 8.10 (1H), 8.01-7.97 (2H), 7.94 (1H), 7.86 (1H), 7.83-7.80 (5H), 7.59 (1H), 7.56-7.49 (3H), 7.39 (2H), 7.20-7.12 (7H).

[0080] [Characteristic Evaluation of Compounds] (Measurement of Melting Point and Glass Transition Point) The melting point and glass transition point (Tg) of each compound obtained in Examples 1 to 4 were measured. The measurements were carried out using a high-sensitivity differential scanning calorimeter (manufactured by Bruker AXS, trade name: DSC3100SA). The measurement results are shown in Table 1.

[0081]

[0082] As shown in Table 1, the compounds according to the present invention obtained in Examples 1 to 4 had high melting points and glass transition points of 100° C. or higher. This result indicates that the compounds according to Examples 1 to 4 are stable in the thin film state and have excellent durability.

[0083] (Measurement of Work Function) Using each of the compounds obtained in Examples 1 to 4, a vapor-deposited film having a thickness of 100 nm was formed on an ITO substrate, and the work function (unit: eV) was measured. The measurement was performed using an ionization potential measurement device (manufactured by Sumitomo Heavy Industries, Ltd., product name: PYS-202). The measurement results are shown in Table 2.

[0084]

[0085] As shown in Table 2, the compounds according to the present invention obtained in Examples 1 to 4 exhibit a preferable energy level compared to the work function (5.4 eV) of common hole transport materials such as NPD and TPD. This result indicates that the compounds according to Examples 1 to 4 have good hole transport ability and excellent electron blocking ability.

[0086] [Evaluation of Organic EL Device Characteristics] (Fabrication of Organic EL Device) Organic EL devices were fabricated using the compounds according to the present invention obtained in Examples 1 to 4, as well as comparative compounds (EBL-1), (EBL-2), and (EBL-3) having the following structures (see, for example, Patent Document 4) in the electron-blocking layer. As shown in FIG. 13 , the organic EL device was fabricated by vapor-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 was previously formed as a transparent anode 2. The specific fabrication procedure was as follows:

[0087]

[0088] A 50 nm thick ITO film, a 100 nm thick silver alloy reflective film, and a 5 nm thick ITO film were sequentially formed on a glass substrate 1 as a transparent anode 2. The resulting substrate was subjected to ultrasonic cleaning in isopropyl alcohol for 20 minutes and then dried on a hot plate heated to 250°C for 10 minutes. After that, UV ozone treatment was performed for 2 minutes, and the ITO-coated glass substrate was mounted in a vacuum deposition machine and the pressure was reduced to 0.001 Pa or less. Subsequently, an electron acceptor (Acceptor-1) and a compound (HTM-1) having the following structure were binary-evaporated so as to cover the transparent anode 2 at a deposition rate ratio of Acceptor-1:Compound (HTM-1) = 3:97, to form a 10 nm thick hole injection layer 3. On this hole injection layer 3, a compound (HTM-1) having the following structure was vapor-deposited to form a hole transport layer 4 with a thickness of 140 nm. On this hole transport layer 4, a compound according to the example or a comparative compound was vapor-deposited to form an electron blocking layer 5 with a thickness of 5 nm. On this electron blocking layer 5, a compound (EMD-1) and a compound (EMH-1) having the following structures were vapor-deposited at a vapor deposition rate ratio of compound (EMD-1):compound (EMH-1) = 5:95, to form a light-emitting layer 6 with a thickness of 20 nm. On this light-emitting layer 6, a compound (ETM-1) and a compound (ETM-2) having the following structures were vapor-deposited at a vapor deposition rate ratio of compound (ETM-1):compound (ETM-2) = 50:50, to form a 30 nm-thick electron transport layer 7. On this electron transport layer 7, lithium fluoride was vapor-deposited to form an electron injection layer 8 with a thickness of 1 nm. A magnesium-silver alloy was vapor-deposited on the electron injection layer 8 to form a cathode 9 with a thickness of 12 nm. Finally, a compound (CPL-1) having the following structure was vapor-deposited on the cathode 9 to form a capping layer 10 with a thickness of 60 nm. As described above, organic EL devices according to Examples 1 to 4 and Comparative Examples 1 to 3 were fabricated using the compounds according to Examples 1 to 4 and Comparative Compounds 1 to 3.

[0089]

[0090]

[0091]

[0092] (Measurement of Light Emitting Characteristics of Organic EL Device) Each of the prepared organic EL devices was subjected to a current density of 10 mA / cm in air at room temperature. ２ The light-emitting characteristics were measured when a current of 1000 kJ / s was passed through the device. The measurement results are shown in Table 3.

[0093] (Measurement of Lifetime of Organic EL Elements) The lifetime of each of the produced organic EL elements was measured, and the results are shown in Table 3. In the present invention, the lifetime of the element is measured at a current density of 10 mA / cm ２ The initial luminance when driven at a constant current of 100% was measured as the time it took for the luminance to decay to 95%.

[0094]

[0095] 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 through the organic EL elements of Examples 1 to 4 was 8.96 to 9.12 cd / A, which was higher than that of the organic EL elements of Comparative Examples 1 to 3 (8.25 to 8.26 cd / A). Furthermore, the power efficiency was also higher, at 8.29 to 8.39 lm / W, which was higher than that of the organic EL elements of Comparative Examples 1 to 3 (8.21 to 8.22 lm / W). Furthermore, it can be seen that the organic EL elements of Examples 1 to 4 had a longer element life of 425 to 467 hours, which was higher than that of the organic EL elements of Comparative Examples 1 to 3 (351 to 360 hours).

[0096] From the above results, it was found that the organic EL device of the present invention, which uses an arylamine compound having high hole mobility, excellent electron blocking ability, and excellent stability and durability in a thin film state, has higher luminous efficiency and power efficiency, lower light-emission onset voltage and practical driving voltage, and longer life compared to conventional organic EL devices.

[0097] While certain preferred embodiments of the present invention have been shown and described in detail above, it should be understood that the present invention is not limited to the above-described embodiments, but that various changes and modifications are possible without departing from the spirit or scope of the appended claims.

[0098] This application claims priority based on Japanese Patent Application No. 2024-048794, filed on March 25, 2024, the entire contents of which are incorporated herein by reference.

[0099] In an organic EL device using the arylamine compound of the present invention having a specific structure, the luminous efficiency is improved and the durability of the device is also improved, so that the device can be applied to, for example, home appliances and lighting.

[0100] REFERENCE SIGNS LIST 1 glass substrate 2 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): In the general formula (I), Ar １ and Ar ２ each independently represents a substituted or unsubstituted aryl group or a substituted or unsubstituted heteroaryl group; １ ~L ３ each independently represents a single bond, a substituted or unsubstituted arylene group, or a substituted or unsubstituted heteroarylene group, and A represents a naphthyl group optionally substituted with a deuterium atom and represented by the following general formula (II): In general formula (II), R represents a substituted or unsubstituted aryl group or a substituted or unsubstituted heteroaryl group, n represents an integer of 2 or 3, and a plurality of R may be the same or different, and L ３ is as defined in the general formula (I) above.

2. The arylamine compound according to claim 1, wherein n is 2 in the general formula (II).

3. In the general formula (I), L １ is a single bond, and Ar １ is a deuterium-substituted or unsubstituted aryl group or a deuterium-substituted or unsubstituted heteroaryl group, and A is a naphthyl group optionally substituted with a deuterium atom and selected from the group consisting of the following general formulae (II-A-8) to (II-A-14): L in general formulae (II-A-8) to (II-A-14) ３ and R is as defined in the general formula (I) and the general formula (II).

4. In the general formula (I), L ３ The arylamine compound according to claim 3 , wherein is a deuterium-substituted or unsubstituted phenylene group, a deuterium-substituted or unsubstituted biphenyldiyl group, or a deuterium-substituted or unsubstituted naphthylene group.

5. In the general formula (I), Ar １ is a deuterium-substituted or unsubstituted phenyl group, a deuterium-substituted or unsubstituted biphenylyl group, a deuterium-substituted or unsubstituted terphenylyl group, a deuterium-substituted or unsubstituted naphthyl group, a deuterium-substituted or unsubstituted phenanthryl group, or a deuterium-substituted or unsubstituted dibenzofuranyl group.

6. The arylamine compound according to claim 5, wherein, in general formula (II), R is a deuterium-substituted or unsubstituted phenyl group, a deuterium-substituted or unsubstituted biphenylyl group, a deuterium-substituted or unsubstituted naphthyl group, a deuterium-substituted or unsubstituted phenanthryl group, or a deuterium-substituted or unsubstituted dibenzofuranyl group.

7. The arylamine compound according to claim 6, wherein in general formula (II), R is a deuterium-substituted or unsubstituted phenyl group.

8. The arylamine compound according to claim 1, wherein in general formula (I), A is a naphthyl group optionally substituted with a deuterium atom and selected from the group consisting of general formulas (II-A-1) to (II-A-7) below: L in general formulae (II-A-1) to (II-A-7) ３ and R is as defined in the general formula (I) and the general formula (II).

9. The arylamine compound according to claim 8, wherein, in general formulas (II-A-1) to (II-A-7), R is a deuterium-substituted or unsubstituted phenyl group, a deuterium-substituted or unsubstituted biphenylyl group, a deuterium-substituted or unsubstituted naphthyl group, a deuterium-substituted or unsubstituted phenanthryl group, or a deuterium-substituted or unsubstituted dibenzofuranyl group.

10. In the general formula (I), L ３ The arylamine compound according to claim 9, wherein is a single bond, a deuterium-substituted or unsubstituted phenylene group, a deuterium-substituted or unsubstituted biphenyldiyl group, or a deuterium-substituted or unsubstituted naphthylene group.

11. In the general formula (I), Ar １ is a substituted or unsubstituted phenyl group, a substituted or unsubstituted biphenylyl group, a substituted or unsubstituted terphenylyl group, a substituted or unsubstituted naphthyl group, a substituted or unsubstituted phenanthryl group, or a substituted or unsubstituted dibenzofuranyl group.

12. The arylamine compound according to claim 11, wherein in said general formula (I), A is a naphthyl group selected from the group consisting of said general formulae (II-A-1) to (II-A-3).

13. In the general formula (I), Ar １ is a deuterium-substituted or unsubstituted phenyl group, a deuterium-substituted or unsubstituted biphenylyl group, a deuterium-substituted or unsubstituted terphenylyl group, a deuterium-substituted or unsubstituted naphthyl group, a deuterium-substituted or unsubstituted phenanthryl group, or a deuterium-substituted or unsubstituted dibenzofuranyl group.

14. The arylamine compound according to claim 13, wherein in the general formulae (II-A-1) to (II-A-3), R is a deuterium-substituted or unsubstituted phenyl group.

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

16. The organic electroluminescence device according to claim 15, wherein the organic layer containing the arylamine compound is at least one layer selected from the group consisting of a hole injection layer, a hole transport layer, an electron blocking layer, and a light-emitting layer.

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

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