Adamantane compound and device containing same

Abstract

To provide a novel adamantane compound and further provide an organic electroluminescent device having excellent heat resistance, and excellent longevity or luminous efficiency.SOLUTION: The present invention provides an adamantane compound represented by the general formula (1), where Ar1 is a C6-24 aromatic hydrocarbon group; Ar2 is a single bond or a C6-24 aromatic hydrocarbon group; Ar3 is a C6-24 aromatic hydrocarbon group; Ad is a 1-adamantyl group or 2-adamantyl group; a, b and d each represent 1 or 2, and c is 0 or 1, where a+b+c=3; Z1, Z2 and Z3 independently represent a nitrogen atom or C-H.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a novel cyclic azine compound having an adamantyl group and an organic electroluminescent device containing the same.

[0002] Conventional organic electroluminescent devices have a higher driving voltage than inorganic light-emitting diodes, lower luminance and luminous efficiency, and significantly shorter device lifespan, preventing their practical application. Although recent organic electroluminescent devices have gradually improved, there is a demand for materials with even better luminous efficiency, driving voltage, and long lifespan characteristics. Furthermore, some applications, such as automotive applications, require high heat resistance, and materials with a high glass transition temperature (Tg) are required.

[0003] Examples of electron transport materials with excellent long life for organic electroluminescent devices include the adamantane compounds disclosed in Patent Document 1 and the triazine compounds disclosed in Patent Document 2. Patent Documents 3 to 7 disclose compounds having an adamantyl group for organic electroluminescent devices. However, further improvements have been required in terms of the heat resistance of the materials, and the voltage, life, and luminous efficiency of organic electroluminescent devices using these materials. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-34159 [Patent Document 2] Japanese Patent Application Laid-Open No. 2007-314503 [Patent Document 3] Chinese Patent Application Publication No. 112661709 [Patent Document 4] Korean Patent Publication No. 10-2021-0062458 [Patent Document 5] Chinese Patent Application Publication No. 111662241 [Patent Document 6] Chinese Patent Application Publication No. 111646951 [Patent Document 7] Chinese Patent Application Publication No. 111961038 Summary of the Invention [Problem to be solved by the invention]

[0005] One aspect of the present invention is to provide a new adamantane compound, and another aspect is to provide an organic electroluminescent device that is excellent in heat resistance, long life, or luminous efficiency. [Means for solving the problem]

[0006] The invention according to the present disclosure includes the following aspects. <Aspect 1> Adamantane compounds represented by general formula (1): [ka] During the ceremony, Ar 1 represents an aromatic hydrocarbon group having 6 to 24 carbon atoms; Ar 2 represents a single bond or an aromatic hydrocarbon group having 6 to 24 carbon atoms; Ar 3 represents an aromatic hydrocarbon group having 6 to 24 carbon atoms; Ar 1 , Ar when it is an aromatic hydrocarbon group 2 , and Ar 3 are each unsubstituted or substituted with one or more substituents selected from the group consisting of one or more phenyl groups, naphthyl groups, phenanthryl groups, anthryl groups, triphenylenyl groups, terphenyl groups, methyl groups, tert-butyl groups, fluoro groups, and deuterium; Ad represents a 1-adamantyl group or a 2-adamantyl group; a represents 1 or 2; b represents 1 or 2; c represents 0 or 1; d represents 1 or 2; However, a+b+c=3; Z 1 , Z 2 and Z 3 each independently represents a nitrogen atom or CH. <Aspect 2> Z 1 , Z 2 and Z 3 and n is 0 or 1. The adamantane compound according to embodiment 1, wherein two or more of <Aspect 3> Z 1 , Z 2 and Z 3 wherein two are nitrogen atoms and one is CH. <Aspect 4> Ar 2 The adamantane compound according to any one of Aspects 1 to 3, wherein is an aromatic hydrocarbon group having 6 to 24 carbon atoms. <Aspect 5> Ar 2 is a phenylene group optionally substituted with a phenyl group or a biphenylylene group. <Aspect 6> Ar 2 The adamantane compound according to Aspect 4, wherein is a 1,4-phenylene group or a 4,4′-biphenylylene group optionally substituted with a phenyl group. <Aspect 7> Ar 2 is unsubstituted. <Aspect 8> Ar 1 The adamantane compound according to any one of Aspects 1 to 7, wherein is an aromatic hydrocarbon group having 12 to 16 carbon atoms. <Aspect 9> Ar 1 The adamantane compound according to any one of Aspects 1 to 7, wherein is a 4-biphenylyl group or a 4-naphthylphenyl group. <Aspect 10> Ar 1 and Ar 3The adamantane compound according to any one of Aspects 1 to 7, wherein each independently represents a phenyl group or a phenyl group optionally substituted with a naphthyl group. <Aspect 11> Ar 1 and Ar 3 The adamantane compound according to any one of Aspects 1 to 9, wherein is unsubstituted. <Aspect 12> The adamantane compound according to embodiment 1, represented by general formula (1-1): [ka] During the ceremony, R 1 represents a single bond, a hydrogen atom, or an aromatic hydrocarbon group having 6 to 18 carbon atoms; R 2 represents a hydrogen atom or an aromatic hydrocarbon group having 6 to 18 carbon atoms; R 3 represents a single bond or an aromatic hydrocarbon group having 6 to 18 carbon atoms; R 1 and R 2 or both of the above are aromatic hydrocarbon groups having 6 to 18 carbon atoms; R 1 , R 2 , and R 3 When each of the groups is an aromatic hydrocarbon group, it is unsubstituted or substituted with one or more substituents selected from the group consisting of one or more phenyl groups, naphthyl groups, phenanthryl groups, anthryl groups, triphenylenyl groups, terphenyl groups, methyl groups, tert-butyl groups, fluoro groups, and deuterium groups; Ad represents a 1-adamantyl group or a 2-adamantyl group; e represents 0, 1 or 2; f represents 1 or 2; Z 1 , Z 2 and Z 3 each independently represents a nitrogen atom or CH; Z 1 , Z 2 and Z 3 At least two of the groups are nitrogen atoms. <Aspect 13> R 1 , R 2 and R 3 Aspect 13. The adamantane compound according to aspect 12, wherein the aromatic hydrocarbon group has 6 to 12 carbon atoms. <Aspect 14> R 1 , R 2 and R 3 and n is an aromatic hydrocarbon group, and n is an aromatic hydrocarbon group. <Aspect 15> The adamantane compound according to any one of aspects 12 to 14, wherein e=0. <Aspect 16> R 1 is a phenyl group or a naphthyl group, R 2 is a hydrogen atom or a phenyl group; 16. An adamantane compound according to embodiment 15. <Aspect 17> R 3 17. The adamantane compound according to any one of embodiments 15 to 16, wherein is a single bond or a phenylene group. <Aspect 18> An organic electroluminescent device containing an adamantane compound represented by general formula (1): [ka] During the ceremony, Ar 1 represents an aromatic hydrocarbon group having 6 to 24 carbon atoms; Ar 2 represents a single bond or an aromatic hydrocarbon group having 6 to 24 carbon atoms; Ar 3 represents an aromatic hydrocarbon group having 6 to 24 carbon atoms; Ar 1 , Ar when it is an aromatic hydrocarbon group 2 , and Ar 3are each unsubstituted or substituted with one or more substituents selected from the group consisting of one or more phenyl groups, naphthyl groups, phenanthryl groups, anthryl groups, triphenylenyl groups, biphenylyl groups, terphenyl groups, methyl groups, tert-butyl groups, fluoro groups, and deuterium groups; Ad represents a 1-adamantyl group or a 2-adamantyl group; a represents 1 or 2; b represents 1 or 2; c represents 0 or 1; d represents 1 or 2; However, a+b+c=3; Z 1 , Z 2 and Z 3 each independently represents a nitrogen atom or CH. <Aspect 19> Aspect 19. The organic electroluminescent device according to aspect 18, wherein the layer containing the adamantane compound represented by general formula (1) is an electron transport layer. <Aspect 20> 20. The organic electroluminescent device according to embodiment 18 or 19, wherein the organic electroluminescent device is doped with the adamantane compound represented by general formula (1). <Aspect 21> 21. The organic electroluminescent device of embodiment 20, wherein the dopant is Liq. [Effects of the Invention]

[0007] According to one aspect of the present invention, a novel adamantane compound is provided, and in another aspect, an electron transport material having excellent heat resistance, long life and / or luminous efficiency can be provided. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic cross-sectional view of a preferred embodiment of an organic electroluminescent device containing an adamantane compound according to one aspect of the present invention. [Figure 2] FIG. 2 is a schematic cross-sectional view of an organic electroluminescent device according to Example 1 of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments of the present invention will be described in detail.

[0010] One aspect of the present invention relates to an adamantane compound represented by the above general formula (1) (hereinafter also referred to as "adamantane compound (1)" or simply "compound (1)"), and an organic electroluminescent device containing the same.

[0011] <Adamantane compound represented by general formula (1)> The adamantane compound according to one embodiment of the present invention is represented by the general formula (1).

[0012] [ka] During the ceremony, Ar 1 represents an aromatic hydrocarbon group having 6 to 24 carbon atoms; Ar 2 represents a single bond or an aromatic hydrocarbon group having 6 to 24 carbon atoms; Ar 3 represents an aromatic hydrocarbon group having 6 to 24 carbon atoms; Ar 1 , Ar when it is an aromatic hydrocarbon group 2 , and Ar 3 are each unsubstituted or substituted with one or more substituents selected from the group consisting of one or more phenyl groups, naphthyl groups, phenanthryl groups, anthryl groups, triphenylenyl groups, terphenyl groups, methyl groups, tert-butyl groups, fluoro groups, and deuterium; Ad represents a 1-adamantyl group or a 2-adamantyl group; a represents 1 or 2; b represents 1 or 2; c represents 0 or 1; d represents 1 or 2; However, a+b+c=3; Z 1 , Z 2and Z 3 each independently represents a nitrogen atom or CH.

[0013] The adamantane compound represented by formula (1) according to an embodiment of the present invention has high amorphousness, a high glass transition temperature relative to its molecular weight, and electroluminescent device properties such as high luminous efficiency, long life, and low voltage. Without intending to be limited by theory, this is thought to be due to the presence of an adamantyl group that is highly sterically hindered and has donor properties.

[0014] The Tg of the adamantane compound represented by formula (1) according to an embodiment of the present invention is preferably 110°C or higher, and more preferably 130°C or higher. Adamantane compounds having a relatively high Tg are particularly advantageous for use in organic electroluminescent devices that require high heat resistance. This Tg was measured using a DSC (Differential Scanning Calorimetry) device in an atmosphere of 23°C and 50% RH.

[0015] ≪Ar 1 , Ar 2 and Ar 3 ≫ Ar 2 represents a single bond or an aromatic hydrocarbon group having 6 to 24 carbon atoms. 1 and Ar 3 each independently represents an aromatic hydrocarbon group having 6 to 24 carbon atoms.

[0016] The term "aromatic hydrocarbon group" refers to a hydrocarbon group containing a benzene ring, and has, for example, a ring structure (single ring or fused ring) or a structure in which multiple ring structures are bonded together with a single bond.

[0017] Ar 1 and Ar 3The aromatic hydrocarbon group having 6 to 24 carbon atoms in the formula (I) is not particularly limited, but preferred examples include a phenyl group, a biphenylyl group, a terphenyl group, a naphthyl group, a phenanthryl group, an anthryl group, a pyrenyl group, a triphenylenyl group, a chrysenyl group, a fluoranthenyl group, an acenaphthylenyl group, a fluorenyl group, and a benzofluorenyl group.

[0018] Ar 2 Regarding the above, the aromatic hydrocarbon group having 6 to 24 carbon atoms is not particularly limited, but preferred examples include a phenylene group, a biphenylylene group, a terphenylylene group, a naphthylene group, a phenanthrenediyl group, an anthracenediyl group, a pyrenediyl group, a torrylenephendiyl group, a chrysenediyl group, a fluoranthenediyl group, an acenaphthylenediyl group, a fluorenediyl group, and a benzofluorenediyl group. 2 With regard to the above, the aromatic hydrocarbon group having 6 to 24 carbon atoms is a (preferably unsubstituted) phenylene group or a biphenylylene group.

[0019] Ar 1 , Ar when it is an aromatic hydrocarbon group 2 , and Ar 3 may each be unsubstituted or substituted with one or more substituents selected from the group consisting of a single or multiple phenyl group, a naphthyl group, a phenanthryl group, an anthryl group, a triphenylenyl group, a biphenylyl group, a terphenyl group, a methyl group, a tert-butyl group, a fluoro group, and a deuterium atom.

[0020] Ar 1 , Ar 2 , and Ar 3 It is particularly preferred that is unsubstituted.

[0021] Ar 2 is preferably an aromatic hydrocarbon group having 6 to 24 carbon atoms. 2 is a phenyl group-substituted or unsubstituted (preferably unsubstituted) phenylene group or biphenylylene group, and more particularly preferably, Ar2 is a phenyl-substituted or unsubstituted (preferably unsubstituted) 1,4-phenylene group or 4,4'-biphenylylene group.

[0022] Ar 1 is preferably an unsubstituted aromatic hydrocarbon group having 6 to 24 carbon atoms, and more preferably an aromatic hydrocarbon group having 12 to 16 carbon atoms. 1 may be a phenyl group or a phenyl group substituted with a naphthyl group. 1 However, a 4-biphenylyl group or a 4-naphthylphenyl group is particularly preferred, and a 4-biphenylyl group is most preferred.

[0023] Ar 3 is preferably an unsubstituted aromatic hydrocarbon group having 6 to 24 carbon atoms, and more preferably an aromatic hydrocarbon group having 12 to 16 carbon atoms. 3 may be a phenyl group or a phenyl group substituted with a naphthyl group. 3 is preferably an unsubstituted phenyl group, a biphenylyl group, a naphthyl group, a phenyl group substituted with a naphthyl group, a phenanthryl group, an anthryl group, or a phenyl group substituted with an anthryl group, and particularly preferably an unsubstituted phenyl group or an unsubstituted biphenylyl group.

[0024] a, b, c and d a represents 1 or 2, b represents 1 or 2, c represents 0 or 1, and d represents 1 or 2. However, a+b+c=3. It is preferable that a=b=c=1.

[0025] ≪Z 1 , Z 2 and Z 3 ≫ Z 1 , Z 2 and Z 3 Each independently represents a nitrogen atom or CH. 1 , Z 2 and Z 3Among these, it is preferred that at least two are nitrogen atoms, and it is more preferred that two are nitrogen atoms and one is CH.

[0026] <Preferred Examples of Adamantane Compounds Represented by General Formula (1)> Examples of the adamantane compound represented by the general formula (1) include the compounds represented by the following formulas (A1) to (A34). 1 " indicates a 1-adamantyl group, and "Ad 2 " denotes a 2-adamantyl group.

[0027] [ka]

[0028] [ka]

[0029] [ka]

[0030] [ka]

[0031] Ar 2 Although there is no particular limitation, the following (B1) to (B47) can be mentioned as examples.

[0032] [ka]

[0033] [ka]

[0034] [ka]

[0035] Ar 1 - or Ar 3 Although there is no particular limitation to -, examples thereof include the following (C1) to (C71).

[0036] [ka]

[0037] [ka]

[0038] [ka]

[0039] [ka]

[0040] The compound (1) of the present invention has a basic skeleton (A1) to (A34) and an Ar group represented by (B1) to (B47). 2 , Ar represented by (C1) to (C71) 1 , and Ar represented by (C1) to (C71) 3 A compound in which the above is combined is a preferred example. More preferred examples of the compound (1) of the present invention include the following (D1) to (D232). 1 " indicates a 1-adamantyl group, and "Ad 2 " denotes a 2-adamantyl group.

[0041] [ka]

[0042] [ka]

[0043]

change

[0044]

change

[0045]

change

[0046]

change

[0047]

change

[0048]

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[0049]

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[0050]

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[0051]

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[0052]

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[0053] The Tg of all of the above example compounds is 100° C. or higher.

[0054] Among the adamantane compounds represented by the above general formula (1), the adamantane compounds represented by the following general formula (1-1) are particularly preferred:

[0055] [ka]

[0056] In formula (1-1), R 1 represents a single bond, a hydrogen atom, or an aromatic hydrocarbon group having 6 to 18 carbon atoms; R 2 represents a hydrogen atom or an aromatic hydrocarbon group having 6 to 18 carbon atoms; R 3 represents a single bond or an aromatic hydrocarbon group having 6 to 18 carbon atoms; R 1 and R 2 or both of the above are aromatic hydrocarbon groups having 6 to 18 carbon atoms; R 1 , R 2 , and R 3 When each of the groups is an aromatic hydrocarbon group, it is unsubstituted or substituted with one or more substituents selected from the group consisting of one or more phenyl groups, naphthyl groups, phenanthryl groups, anthryl groups, triphenylenyl groups, terphenyl groups, methyl groups, tert-butyl groups, fluoro groups, and deuterium groups; Ad represents a 1-adamantyl group or a 2-adamantyl group; e represents 0, 1 or 2; f represents 1 or 2; Z 1 , Z 2 and Z 3 each independently represents a nitrogen atom or CH; Z 1 , Z 2 and Z 3 At least two of the groups are nitrogen atoms.

[0057] The adamantane compound represented by the general formula (1-1) is Z 1 , Z 2 , and Z 3 Three benzene rings are bonded to an aromatic ring (especially a heteroaromatic ring such as triazine or pyrimidine) having the formula 1 ~R 3 are linked in the para position.

[0058] Adamantane compounds having such a structure are particularly useful as materials for organic electroluminescent elements (particularly as materials for electron transport layers), and by using these compounds, organic electroluminescent elements having particularly excellent luminous efficiency characteristics, driving voltage characteristics, and long life characteristics can be obtained.

[0059] In the adamantane compound represented by the general formula (1-1), R 1 ~R 3 At least one of the groups is an aromatic hydrocarbon group having 6 to 18 carbon atoms. That is, the adamantane compound represented by the general formula (1-1) is 1 , Z 2 , and Z 3 The aromatic hydrocarbon ring is bonded at the para position to a benzene ring which is bonded to an aromatic ring (particularly a heteroaromatic ring such as triazine or pyrimidine) having the formula:

[0060] Without intending to be bound by theory, Z 1 , Z 2 , and Z 3 In the case where an aromatic hydrocarbon ring is bonded at the para position to a benzene ring bonded to an aromatic ring (especially a heteroaromatic ring such as triazine or pyrimidine) having 1 , Z 2 , and Z 3 It is believed that the LUMO distributed around the aromatic ring (particularly triazine or pyrimidine) having the formula (I) spreads over a wide range, resulting in an improvement in the mobility (electron mobility) of the compound.

[0061] Here, in the past, when an organic electroluminescent device was manufactured using a compound having such a structure, good performance could not be obtained in some cases (see, for example, compound ETL-2 described in the Examples of the present application). Without intending to be limited by theory, it is believed that when a compound having such a molecular structure is used as a material for a layer (e.g., an electron transport layer) constituting an organic electroluminescent device, the energy barrier between layers in the device becomes high, resulting in a decrease in the efficiency of the organic electroluminescent device.

[0062] In contrast, the adamantane compound represented by the general formula (1-1) according to the present invention exhibits excellent mobility, and an organic electroluminescent device produced using this compound exhibits particularly high efficiency. The adamantane compound represented by the general formula (1-1) according to the present invention exhibits excellent mobility, and an organic electroluminescent device produced using this compound exhibits particularly high efficiency. 1 , Z 2 , and Z 3 In addition to the aromatic hydrocarbon ring bonded at the para position to the benzene ring bonded to the aromatic ring (particularly triazine or pyrimidine) having the formula (I), the compound further has an adamantyl group, which is thought to enable an organic electroluminescent device having not only excellent mobility but also particularly high performance.

[0063] Without intending to be limited by theory, it is believed that in the adamantane compound of the above general formula (1-1) according to the present invention, the sterically bulky adamantyl group suppresses exciton deactivation at the interface with adjacent layers in the device. Specifically, for example, if an intermediate such as an exciplex is generated by interaction between the light-emitting layer and the electron-transporting layer, the energy of the exciton is deactivated, which can cause a decrease in luminous efficiency. However, it is believed that the bulky adamantyl group can suppress the formation of such exciplexes.

[0064] R when e=1 or 2 1 , and R 3 Examples of R when e=0 include (B1) to (B47) above. 1 , and R 2 Examples of the above include (C1) to (C71).

[0065] When e=1 or 2, R 1 may represent a single bond or an aromatic hydrocarbon group having 6 to 18 carbon atoms. When e=0, R 1 may represent a hydrogen atom or an aromatic hydrocarbon group having 6 to 18 carbon atoms.

[0066] R 1 , R 2 and R 3 With regard to the above, the aromatic hydrocarbon group preferably has 6 to 12 carbon atoms (particularly 6 to 10 carbon atoms).

[0067] R 1 , R 2 and R 3 When each of is an aromatic hydrocarbon group, it is preferably unsubstituted.

[0068] It is preferable that e is 0 (e=0). When e=0, R 1 is preferably a phenyl group or a naphthyl group, and R 2 is preferably a hydrogen atom or a phenyl group, and / or R 3 is preferably a single bond or a phenylene group.

[0069] When e=0, general formula (1-1) is represented by the following general formula (1-10).

[0070] [ka]

[0071] The adamantane compound represented by the general formula (1-1) is particularly preferably an adamantane compound represented by the following general formula (1-11), (1-12) or (1-13).

[0072] [ka]

[0073] [ka]

[0074] [ka]

[0075] <Method for producing an adamantane compound represented by formula (1)> The adamantane compound (1) according to an embodiment of the present invention can be produced, for example, by the cross-coupling reactions shown in the following reaction schemes 1 to 3.

[0076] [ka]

[0077] [ka]

[0078] [ka]

[0079] In reaction formulas 1 to 3, X represents F, Cl, Br, I, OTf, or a group having F, Cl, Br, I, or OTf as a partial structure. M represents a metal group or an organometallic group effective in the coupling reaction, such as Li, Na, B(OR 11 )2, MgBr, MgCl, ZnCl, ZnBr, ZnCl, Zn(tmeda), Sn(n-Bu)3, SiMe3, etc.

[0080] where R 11 represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or a phenyl group, and two R 11 may be the same or different. 11 and the boron atom may form a ring. That is, B(OR 11 )2 includes the following (I) to (VI) as examples.

[0081] [ka]

[0082] The cross-coupling reaction can be carried out under the reaction conditions described in, for example, JP-A 2015-34159 and WO 2019 / 191454.

[0083] <Organic electroluminescent device containing an adamantane compound represented by formula (1)> An organic electroluminescent device containing the adamantane compound (1) according to the present disclosure (hereinafter, sometimes simply referred to as an organic electroluminescent device) will be described below.

[0084] An organic electroluminescent device according to one aspect of the present invention contains the adamantane compound (1) according to the present disclosure, and in particular has a layer containing the adamantane compound (1) according to the present disclosure.

[0085] The configuration of the organic electroluminescent device is not particularly limited, but examples thereof include the following configurations (i) to (v).

[0086] (i): Anode / Emitting layer / Cathode (ii): Anode / hole transport layer / light-emitting layer / cathode (iii): Anode / Emitting layer / Electron transport layer / Cathode (iv): Anode / hole transport layer / light-emitting layer / electron transport layer / cathode (v): Anode / hole injection layer / hole transport layer / light-emitting layer / electron transport layer / electron injection layer / cathode

[0087] The adamantane compound (1) according to the present disclosure may be contained in any of the above layers, but is preferably contained in one or more layers selected from the group consisting of layers between the light-emitting layer and the cathode, in order to provide excellent light-emitting properties for the organic electroluminescent device. Therefore, in the case of the structures (i) to (v) above, the adamantane compound (1) is preferably contained in one or more layers selected from the group consisting of the electron-transporting layer and the electron-injecting layer.

[0088] Hereinafter, an organic electroluminescent device according to one embodiment of the present invention will be described in more detail with reference to FIG. 1, taking the above configuration (v) as an example.

[0089] 1 has a so-called bottom-emission type element configuration, the organic electroluminescent element according to one embodiment of the present invention is not limited to the bottom-emission type element configuration. That is, the organic electroluminescent element according to one embodiment of the present invention may have another known element configuration, such as a top-emission type.

[0090] 1 includes, in this order, a substrate 1, an anode 2, a hole injection layer 3, a hole transport layer 4, an emitting layer 5, an electron transport layer 6, an electron injection layer 7, and a cathode 8. However, some of these layers may be omitted, or other layers may be added. For example, a hole blocking layer may be provided between the emitting layer 5 and the electron transport layer 6, or the hole injection layer 3 may be omitted and the hole transport layer 4 may be provided directly on the anode 2.

[0091] Alternatively, a single layer having the functions of multiple layers, such as an electron injection / transport layer having the functions of both an electron injection layer and an electron transport layer, may be provided instead of the multiple layers.Furthermore, for example, the single-layer hole transport layer 4 and the single-layer electron transport layer 6 may each be composed of multiple layers.

[0092] <Layer containing adamantane compound (1)> 1, the organic electroluminescent device 100 contains the adamantane compound (1) in one or more layers selected from the group consisting of the light-emitting layer 5, the electron transport layer 6, and the electron injection layer 7. In particular, it is preferable that the electron transport layer 6 contains the adamantane compound (1). The adamantane compound (1) may be contained in multiple layers of the organic electroluminescent device.

[0093] In the following, an organic electroluminescent device 100 in which the electron transport layer 6 contains the adamantane compound (1) will be described.

[0094] [Board 1] Examples of the substrate 1 include a glass plate, a quartz plate, a plastic plate, and a plastic film. Among these, a glass plate, a quartz plate, and a light-transmitting plastic film are preferred.

[0095] Examples of light-transmitting plastic films include films made of polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyethersulfone (PES), polyetherimide, polyetheretherketone, polyphenylene sulfide, polyarylate, polyimide, polycarbonate (PC), cellulose triacetate (TAC), cellulose acetate propionate (CAP), etc. In the case of a configuration in which light is extracted from the substrate 1 side, the substrate 1 is transparent to the wavelength of light.

[0096] [Anode 2] An anode 2 is provided on the substrate 1 (on the hole injection layer 3 side). Examples of anode materials include metals, alloys, electrically conductive compounds, and mixtures thereof, each having a large work function (e.g., 4 eV or more). Specific examples of anode materials include metals such as Au, and conductive transparent materials such as CuI, indium tin oxide (ITO), SnO, and ZnO. In the case of an organic electroluminescent device configured so that light is extracted through the anode, the anode is formed from a conductive transparent material that is transparent or substantially transparent to the light emitted.

[0097] [Hole injection layer 3, hole transport layer 4] Between the anode 2 and the light-emitting layer 5 described below, a hole injection layer 3 and a hole transport layer 4 are provided in this order from the anode 2 side.

[0098] The hole injection layer and the hole transport layer have the function of transporting holes injected from the anode to the light-emitting layer. By interposing these hole injection layer and hole transport layer between the anode and the light-emitting layer, a large number of holes can be injected into the light-emitting layer with a lower electric field.

[0099] The hole injection layer and the hole transport layer also function as electron barrier layers. That is, electrons injected from the cathode and transported from the electron injection layer and / or the electron transport layer to the light-emitting layer are prevented from leaking to the hole injection layer and / or the hole transport layer due to the electron barrier present at the interface between the light-emitting layer and the hole injection layer and / or the hole transport layer. As a result, the electrons accumulate at the interface within the light-emitting layer, resulting in effects such as improved light-emitting efficiency and providing an organic electroluminescent device with excellent light-emitting performance.

[0100] The material for the hole injection layer and the hole transport layer has at least one of hole injection property, hole transport property, and electron barrier property, and may be either organic or inorganic.

[0101] Specific examples of materials for the hole injection layer and the hole transport layer include triazole derivatives, oxadiazole derivatives, imidazole derivatives, polyarylalkane derivatives, pyrazoline derivatives, pyrazolone derivatives, phenylenediamine derivatives, arylamine derivatives, amino-substituted chalcone derivatives, oxazole derivatives, styrylanthracene derivatives, fluorenone derivatives, hydrazone derivatives, stilbene derivatives, silazane derivatives, aniline-based copolymers, conductive polymer oligomers (particularly thiophene oligomers), porphyrin compounds, aromatic tertiary amine compounds, and styrylamine compounds.

[0102] Among these, porphyrin compounds, aromatic tertiary amine compounds, and styrylamine compounds are preferred in terms of good performance of the organic electroluminescent device, and aromatic tertiary amine compounds are particularly preferred.

[0103] Specific examples of the aromatic tertiary amine compound and the styrylamine compound include N,N,N',N'-tetraphenyl-4,4'-diaminophenyl, N,N'-diphenyl-N,N'-bis(m-tolyl)-[1,1'-biphenyl]-4,4'-diamine (TPD), 2,2-bis(4-di-p-tolylaminophenyl)propane, 1,1-bis(4-di-p-tolylaminophenyl)cyclohexane, N,N,N',N'-tetra-p-tolyl-4,4'-diaminobiphenyl, 1,1-bis(4-di-p-tolylaminophenyl)-4-phenylcyclohexane, bis(4-dimethylamino-2-methylphenyl)phenylmethane, bis(4-di-p-tolylaminophenyl)phenylmethane, N,N'-diphenyl-N,N'- Examples include di(4-methoxyphenyl)-4,4'-diaminobiphenyl, N,N,N',N'-tetraphenyl-4,4'-diaminodiphenyl ether, 4,4'-bis(diphenylamino)quadriphenyl, N,N,N-tri(p-tolyl)amine, 4-(di-p-tolylamino)-4'-[4-(di-p-tolylamino)styryl]stilbene, 4-N,N-diphenylamino-(2-diphenylvinyl)benzene, 3-methoxy-4'-N,N-diphenylaminostilbenzene, N-phenylcarbazole, 4,4'-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (NPD), and 4,4',4''-tris[N-(m-tolyl)-N-phenylamino]triphenylamine (MTDATA).

[0104] Furthermore, inorganic compounds such as p-type Si and p-type SiC can also be given as examples of materials for the hole injection layer and the hole transport layer. The hole injection layer and the hole transport layer may have a single structure made of one or more materials, or may have a laminate structure made of multiple layers of the same or different compositions.

[0105] [Emitting layer 5] The light-emitting layer 5 is provided between the hole transport layer 4 and the electron transport layer 6 described below. Materials for the light-emitting layer include phosphorescent materials, fluorescent materials, and thermally activated delayed fluorescent materials. In the light-emitting layer, electron-hole pairs recombine, resulting in light emission.

[0106] The light-emitting layer may consist of a single small molecule or single polymer material, but more commonly consists of a host material doped with a guest compound. Emission comes primarily from the dopant and can be of any color.

[0107] Examples of the host material include compounds having a biphenylyl group, a fluorenyl group, a triphenylsilyl group, a carbazole group, a pyrenyl group, and an anthryl group. More specific examples include DPVBi (4,4'-bis(2,2-diphenylvinyl)-1,1'-biphenyl), BCzVBi (4,4'-bis(9-ethyl-3-carbazovinylene)1,1'-biphenyl), TBADN (2-tert-butyl-9,10-di(2-naphthyl)anthracene), ADN (9,10-di(2-naphthyl)anthracene), CBP (4,4'-bis(carbazol-9-yl)biphenyl), CDBP (4,4'-bis(carbazol-9-yl)-2,2'-dimethylbiphenyl), 2-(9-phenylcarbazol-3-yl)-9-[4-(4-phenylphenylquinazolin-2-yl)carbazole, 9,10-bis(biphenyl)anthracene, and the like.

[0108] Examples of fluorescent dopants include anthracene, pyrene, tetracene, xanthene, perylene, rubrene, coumarin, rhodamine, quinacridone, dicyanomethylenepyran compounds, thiopyran compounds, polymethine compounds, pyrylium, thiapyrylium compounds, fluorene derivatives, periflanthene derivatives, indenoperylene derivatives, bis(azinyl)amine boron compounds, bis(azinyl)methane compounds, carbostyril compounds, boron compounds, cyclic amine compounds, etc. The fluorescent dopant may be a combination of two or more selected from these.

[0109] Examples of phosphorescent dopants include organometallic complexes of transition metals such as iridium, platinum, palladium, and osmium.

[0110] Specific examples of fluorescent dopants and phosphorescent dopants include Alq3 (tris(8-hydroxyquinoline)aluminum), DPAVBi (4,4'-bis[4-(di-p-tolylamino)styryl]biphenyl), perylene, bis[2-(4-n-hexylphenyl)quinoline](acetylacetonate)iridium(III), Ir(PPy)3 (tris(2-phenylpyridine)iridium(III)), and FIrPic (bis(3,5-difluoro-2-(2-pyridyl)phenyl-(2-carboxypyridyl)iridium(III))).

[0111] Furthermore, the light-emitting material is not limited to being contained only in the light-emitting layer. For example, the light-emitting material may be contained in a layer adjacent to the light-emitting layer (hole transport layer 4 or electron transport layer 6). This can further increase the luminous efficiency of the organic electroluminescent device.

[0112] The light-emitting layer may have a single layer structure made of one or more materials, or may have a laminate structure made of multiple layers of the same or different compositions.

[0113] [Electron transport layer 6] An electron transport layer 6 is provided between the light emitting layer 5 and the electron injection layer 7 described below. The electron transport layer has a function of transporting electrons injected from the cathode to the light-emitting layer. By interposing the electron transport layer between the cathode and the light-emitting layer, electrons are injected into the light-emitting layer at a lower electric field.

[0114] The electron transport layer preferably contains the adamantane compound (1) according to the present disclosure. In addition to the adamantane compound (1), the electron transport layer may further contain one or more types selected from conventionally known electron transport materials.

[0115] When the adamantane compound (1) is not contained in the electron transport layer but is contained in another layer, one or more electron transport materials selected from conventionally known electron transport materials can be used as the electron transport material constituting the electron transport layer.

[0116] Conventionally known electron transporting materials include alkali metal complexes, alkaline earth metal complexes, earth metal complexes, etc. Examples of alkali metal complexes, alkaline earth metal complexes, and earth metal complexes include 8-hydroxyquinolinatolithium (Liq), bis(8-hydroxyquinolinato)zinc, bis(8-hydroxyquinolinato)copper, bis(8-hydroxyquinolinato)manganese, tris(8-hydroxyquinolinato)aluminum, tris(2-methyl-8-hydroxyquinolinato)aluminum, and tris(8-hydroxyquinolinato). Examples of suitable gallium compounds include gallium, bis(10-hydroxybenzo[h]quinolinato)beryllium, bis(10-hydroxybenzo[h]quinolinato)zinc, bis(2-methyl-8-quinolinato)chlorogallium, bis(2-methyl-8-quinolinato)(o-cresolate)gallium, bis(2-methyl-8-quinolinato)-1-naphtholatealuminum, and bis(2-methyl-8-quinolinato)-2-naphtholategallium.

[0117] The electron transport layer may have a single layer structure made of one or more materials, or may have a laminate structure made of multiple layers of the same or different compositions.

[0118] In the organic electroluminescent device according to this embodiment, an electron injection layer may be provided for the purpose of improving electron injection properties and improving device characteristics (for example, luminous efficiency, low-voltage driving, or high durability).

[0119] [Electron injection layer 7] An electron injection layer 7 is provided between the electron transport layer 6 and a cathode 8, which will be described later. The electron injection layer has the function of transferring electrons injected from the cathode to the light-emitting layer. By interposing the electron injection layer between the cathode and the light-emitting layer, electrons are injected into the light-emitting layer at a lower electric field.

[0120] Examples of materials for the electron injection layer include organic compounds such as fluorenone, anthraquinodimethane, diphenoquinone, thiopyran dioxide, oxazole, oxadiazole, triazole, imidazole, perylene tetracarboxylic acid, fluorenylidenemethane, anthraquinodimethane, anthrone, and Liq (8-hydroxyquinolinolato-lithium).Further examples include inorganic compounds such as various oxides, fluorides, nitrides, and oxynitrides of SiO2, AlO, SiN, SiON, AlON, GeO, LiO, LiON, TiO, TiON, TaO, TaON, TaN, LiF, Li, Na, Ca, Mg, CsF, CaCO3, C, and Yb.

[0121] [Cathode 8] A cathode 8 is provided on the electron injection layer 7 . In the case of an organic electroluminescent device having a configuration in which only light emitted through the anode is extracted, the cathode can be formed from any conductive material.

[0122] Examples of materials for the cathode include metals with a low work function (hereinafter also referred to as electron-injecting metals), alloys, electrically conductive compounds, and mixtures thereof. Here, the metals with a low work function are, for example, metals with a work function of 4 eV or less.

[0123] Specific examples of cathode materials include sodium, sodium-potassium alloys, magnesium, lithium, magnesium / copper mixtures, magnesium / silver mixtures, magnesium / aluminum mixtures, magnesium / indium mixtures, aluminum / aluminum oxide (Al2O3) mixtures, indium, lithium / aluminum mixtures, and rare earth metals.

[0124] Among these, from the viewpoints of electron injection properties and durability against oxidation, etc., mixtures of an electron-injecting metal and a second metal that has a larger and more stable work function than the electron-injecting metal, such as magnesium / silver mixtures, magnesium / aluminum mixtures, magnesium / indium mixtures, aluminum / aluminum oxide (Al2O3) mixtures, and lithium / aluminum mixtures, are preferred.

[0125] [How each layer is formed] Each layer except for the electrodes (anode and cathode) described above can be formed into a thin film by a known method such as vacuum deposition, spin coating, casting, LB (Langmuir-Blodgett) method, etc. The material for each layer may be used alone or, if necessary, together with a material such as a binder resin or a solvent.

[0126] There are no particular limitations on the thickness of each layer thus formed, and it can be selected appropriately depending on the situation, but it is usually in the range of 5 nm to 5 μm.

[0127] The anode and cathode can be formed by forming a thin film of an electrode material by a method such as vapor deposition, sputtering, etc. A pattern may be formed through a mask of a desired shape during vapor deposition or sputtering, or a pattern of a desired shape may be formed by photolithography after forming a thin film by vapor deposition, sputtering, etc.

[0128] The thickness of the anode and cathode is preferably 1 μm or less, and more preferably 10 nm or more and 200 nm or less.

[0129] When forming a layer containing adamantane compound (1) (especially an electron transport layer), the adamantane compound (1) may be used in combination with the above-mentioned conventionally known electron transport material. For example, the adamantane compound (1) and the conventionally known electron transport material may be co-deposited, or a layer of the conventionally known electron transport material may be laminated on the layer of adamantane compound (1).

[0130] Organic electroluminescent elements may be used as a type of lamp for illumination or exposure light sources, or as a projection device that projects images onto a screen or the like, or as a display device (display) that directly recognizes still images or moving images. When organic electroluminescent elements are used as a display device for playing moving images, the driving method may be a simple matrix (passive matrix) method or an active matrix method. Furthermore, by using two or more types of organic electroluminescent elements having different emission colors, it is possible to produce a full-color display device.

[0131] The adamantane compound (1) according to the present disclosure, particularly when used as an electron transport layer, can provide organic electroluminescent devices with significantly superior luminous efficiency and low-voltage characteristics compared to conventionally known adamantane compounds. Furthermore, the adamantane compound (1) has high amorphous properties due to its sterically hindered skeleton, and high film stability. Therefore, it is expected to improve the driving stability and luminous efficiency of organic electroluminescent devices. Furthermore, the adamantane compound (1) has high chemical stability due to its characteristic skeleton, and can contribute to extending the life of organic electroluminescent devices.

[0132] The adamantane compound (1) according to the present disclosure can provide a triazine compound that can achieve low-voltage operation, high efficiency, and long life of the device at a high level by using it, particularly as an electron transport layer of an organic electroluminescent device. Furthermore, it is possible to provide an organic electroluminescent device that can achieve low-voltage operation, high efficiency, and long life using the adamantane compound (1). [Example]

[0133] Preferred embodiments of the present invention will be described in more detail below with reference to examples and comparative examples, but the present invention should not be construed as being limited to these.

[0134] [ 1 H-NMR measurement] 1For the H-NMR measurement, a Bruker ASCEND HD (400 MHz; manufactured by BRUKER) was used. 1 H-NMR was measured using deuterated chloroform (CDCl3) as the measurement solvent and tetramethylsilane (TMS) as the internal standard. Commercially available reagents were used.

[0135] [FDMS measurement] FDMS measurements were carried out using a Hitachi M-80B.

[0136] [DSC measurement (glass transition temperature, crystallization temperature)] The glass transition temperature (Tg) and crystallization temperature (Tc) were measured using a DSC (Differential Scanning Calorimetry) instrument DSC7020 (Hitachi High-Tech Science Corp.) Aluminum oxide (Al2O3) was used as the reference in the DSC measurements, and measurements were performed using 10 mg of sample.

[0137] As a pretreatment for the measurement, the sample was heated from 30°C to a temperature above the melting point at a rate of 10°C / min to melt the sample, and then rapidly cooled by contacting the sample with dry ice. The temperature of the pretreated sample was then raised from 30°C at a rate of 10°C / min to measure the glass transition temperature and crystallization temperature.

[0138] <Synthesis example> Synthesis Example 1

[0139] [ka]

[0140] Under an argon atmosphere, 4-(1-adamantyl)phenyl triflate (150.0 g, 416.2 mmol), bis(neopentylglycolate)diboron (103.4 g, 457.8 mmol), potassium acetate (122.5 g, 1248.6 mmol), and palladium acetate (1.87 g, 8.32 mmol) were suspended in THF (1340 mL) and heated to reflux for 17 hours. The resulting reaction mixture was cooled to room temperature and filtered to remove the reaction residue. The filtrate was concentrated to dryness and purified by silica gel chromatography (eluent: toluene) to give the desired 5,5-dimethyl-2-[4-(1-adamantyl)phenyl]-1,3,2-dioxaborinane (85.0 g, 63% yield). 1 HNMR(CDCl3)δ1.01(s,6H),1.56(s,4H),1.77(brs,6H),1.92(brs,6H),2.09(brs,3H),7.36(d,J=8.4Hz,2H),7.75(d,J=8.4Hz,2H).

[0141] Synthesis Example 2

[0142] [ka]

[0143] Under an argon atmosphere, 2,4-dichloro-6-phenyl-1,3,5-triazine (10.0 g, 33.1 mmol), 4-chlorophenylboronic acid (5.69 g, 36.4 mmol), and tetrakis(triphenylphosphine)palladium (765 mg, 0.662 mmol) were suspended in THF (330 mL). To this suspension, 2.0 M aqueous potassium carbonate (49.6 mL) was added and the mixture was heated to reflux for 12 hours. After cooling, water and methanol were added to the reaction mixture. The resulting solid was collected by filtration and purified by recrystallization from toluene to give the desired 2-(4-biphenylyl)-4-chloro-6-(4-chlorophenyl)-1,3,5-triazine (12.5 g, 40% yield). 1HNMR(CDCl3)δ7.43(t,J=7.3Hz,1H),7.49(d,J=7.8Hz,2H),7.54(d,J=8.7Hz,2H),7.69(d d,J=8.5,1.5Hz,2H),7.79(d,J=8.6Hz,2H),8.60(d,J=8.7Hz,2H),8.69(d,J=8.5Hz,2H).

[0144] Synthesis Example 3

[0145] [ka] Under an argon atmosphere, 2-(4-biphenylyl)-4-chloro-6-(4-chlorophenyl)-1,3,5-triazine (5.00 g, 13.2 mmol), 5,5-dimethyl-2-[4-(1-adamantyl)phenyl]-1,3,2-dioxaborinane (4.29 g, 13.2 mmol), and tetrakis(triphenylphosphine)palladium (306 mg, 0.264 mmol) were suspended in toluene (132 mL). To this suspension was added 2.0 M aqueous potassium phosphate solution (19.8 mL) and the mixture was heated to reflux for 21 hours. After cooling, water and methanol were added to the reaction mixture. The resulting solid was collected by filtration and purified by recrystallization from toluene to obtain the target 2-(4-adamantylphenyl)-4-(4-biphenylyl)-6-(4-chlorophenyl)-1,3,5-triazine (6.2 g, yield 85%). 1 HNMR(CDCl3)δ1.82(brs,6H),2.01(brs,6H),2.15(brs,3H),7.42(t,J=7.2Hz,1H),7.49-7.53(m,2 H),7.55(d,J=8.9Hz,2H),7.58(d,J=8.6Hz,2H),7.71(dd,J=8.3,1.2Hz,2H),7.81(d,J=8.6Hz,2H).

[0146] Synthesis Example 4 (D158)

[0147] [ka] Under an argon atmosphere, 2-(4-adamantylphenyl)-4-(4-biphenylyl)-6-(4-chlorophenyl)-1,3,5-triazine (3.00 g, 5.41 mmol), 5,5-dimethyl-2-[4-(1-adamantyl)phenyl]-1,3,2-dioxaborinane (1.93 g, 5.96 mmol), palladium acetate (24.3 mg, 0.108 mmol), and 2-dicyclohexylphosphino-2',4',6'-triisopropylbiphenyl (103 mg, 0.217 mmol) were suspended in tetrahydrofuran (54 mL). To this suspension was added 2.0 M aqueous potassium phosphate solution (8.1 mL) and the mixture was heated to reflux for 20 hours. After cooling, water and methanol were added to the reaction mixture. The resulting solid was collected by filtration and purified by recrystallization from toluene to obtain the desired 2-(4'-adamantylbiphenyl-4-yl)-4-(4-adamantylphenyl)-6-(4-biphenylyl)-1,3,5-triazine (compound D158) (2.85 g, yield 72%). 1 HNMR(CDCl3)δ1.84(brs,12H),2.02(brs,6H),2.04(brs,6H),2.17(brs,6H),7.44(t,J=7.3Hz,1H),7.51-7.55(m,4H),7.61(d,J=8.5Hz,2 H),7.72(d,J=8.5Hz,2H),7.75(d,J=7.2Hz,2H),7.84(d,J=8.0Hz,4H),8.76(d,J=8.6Hz,2H),8.87(d,J=8.3Hz,2H),8.89(d,J=8.4Hz,2H).

[0148] <Synthesis Example 5 (D9)>

[0149] [ka] Under an argon atmosphere, 2-(4-adamantylphenyl)-4-(4-biphenylyl)-6-(4-chlorophenyl)-1,3,5-triazine (2.50 g, 4.51 mmol), 1-naphthaleneboronic acid (0.85 g, 4.96 mmol), palladium acetate (20.3 mg, 0.090 mmol), and 2-dicyclohexylphosphino-2',4',6'-triisopropylbiphenyl (86.0 mg, 0.181 mmol) were suspended in tetrahydrofuran (45 mL). To this suspension was added 2.0 M aqueous potassium phosphate solution (6.8 mL) and the mixture was heated to reflux for 20 hours. After cooling, water and methanol were added to the reaction mixture. The resulting solid was collected by filtration and purified by recrystallization from toluene to obtain the desired 2-(4-adamantylphenyl)-4-(4-biphenylyl)-6-{4-(1-naphthyl)phenyl}-1,3,5-triazine (Compound D9) (1.85 g, yield 64%). 1 HNMR(CDCl3)δ1.85(brs,6H),2.04(brs,6H),2.18(brs,3H),7.43-7.64(m,9H),7.74-7.77(m,4H),7.85 (d,J=8.4Hz,2H),7.94-8.02(m,3H),8.78(d,J=8.7Hz,2H),8.91(d,J=8.4Hz,2H),8.94(d,J=8.4Hz,2H).

[0150] Compound D9 had a Tg of 144°C and no Tc was detected.

[0151] Synthesis Example 6

[0152] [ka] Under an argon atmosphere, 2-(4-adamantylphenyl)-4-(4-biphenylyl)-6-(4-chlorophenyl)-1,3,5-triazine (5.00 g, 9.02 mmol), bis(pinacolato)diboron (2.75 g, 10.8 mmol), palladium acetate (40.5 mg, 0.18 mmol), 2-dicyclohexylphosphino-2',4',6'-triisopropylbiphenyl (172 mg, 0.361 mmol), and potassium acetate (2.66 g, 27.1 mmol) were suspended in THF (90 mL) and heated to reflux for 17 hours. The resulting reaction mixture was cooled to room temperature and then filtered to remove the reaction residue. The obtained filtrate was concentrated to dryness and purified by silica gel chromatography (developing solvent: a mixed solvent of toluene and hexane) to obtain the target 2-(4-adamantylphenyl)-4-(4-biphenylyl)-6-[4-(4,4,5,5-tetramethyl)-1,3,2-dioxaborolan-2-yl]-1,3,5-triazine (4.19 g, yield 72%). 1 HNMR(CDCl3)δ1.40(s,12H),1.82(brs,6H),2.01(brs,6H),2.12(brs,3H),7.42(t,J=7.5Hz,1H),7.51(t,J=7.5Hz,2H),7.59(d,J=8.7Hz,2H) ,7.72(dd,J=8.5,1.4Hz,2H),7.82(d,J=8.3Hz,2H),8.01(d,J=8.3Hz,2H),8.72(d,J=8.5Hz,2H),8.77(d,J=8.1Hz,2H),8.85(d,J=8.4Hz,2H).

[0153] <Synthesis Example 7 (D8)>

[0154] [ka] Under an argon atmosphere, 2-(4-adamantylphenyl)-4-(4-biphenylyl)-6-[4-(4,4,5,5-tetramethyl)-1,3,2-dioxaborolan-2-yl]-1,3,5-triazine (2.00 g, 3.10 mmol), 2-bromonaphthalene (0.77 g, 3.72 mmol), palladium acetate (13.9 mg, 0.062 mmol), and 2-dicyclohexylphosphino-2',4',6'-triisopropylbiphenyl (59.1 mg, 0.124 mmol) were suspended in tetrahydrofuran (31 mL). To this suspension was added 2.0 M aqueous potassium phosphate solution (4.6 mL) and the mixture was heated to reflux for 20 hours. After cooling, water and methanol were added to the reaction mixture. The resulting solid was collected by filtration and purified by recrystallization from toluene to obtain the desired 2-(4-adamantylphenyl)-4-(4-biphenylyl)-6-{4-(2-naphthyl)phenyl}-1,3,5-triazine (Compound D8) (1.20 g, yield 64%). 1 HNMR(CDCl3)δ1.83(brs,6H),2.02(brs,6H),2.16(brs,3H),7.42(t,J=7.2Hz,1H),7.50-7.57(m,4H),7.60(d,=8.8Hz,2H),7.73(d,J=7 .6Hz,2H),7.83(d,J=8.5Hz,2H),7.85-8.00(m,6H),8.18(brs,1H),7.45(d,J=8.7Hz,2H),8.88(d,J=8.6Hz,2H),8.91(d,J=8.7Hz,2H).

[0155] Compound D8 had a Tg of 139°C and no Tc was detected.

[0156] <Synthesis Example 8 (D81)>

[0157] [ka] Under an argon atmosphere, 2-(biphenyl-4-yl)-4-(4-bromophenyl)-6-phenyl-1,3,5-triazine (13.0 g, 28.0 mmol), 5,5-dimethyl-2-[4-(1-adamantyl)phenyl]-1,3,2-dioxaborinane (9.99 g, 30.8 mmol), and tetrakistriphenylphosphinepalladium (647 mg, 0.560 mmol) were suspended in tetrahydrofuran (280 mL). To this suspension was added 2.0 M aqueous potassium phosphate solution (42.0 mL) and the mixture was heated to reflux for 18 hours. After cooling, water and methanol were added to the reaction mixture. The resulting solid was collected by filtration and purified by recrystallization from toluene to obtain the desired 2-(4'-adamantylbiphenyl-4-yl)-4-(4-biphenylyl)-6-phenyl-1,3,5-triazine (Compound D81) (5.20 g, yield 31%). 1 HNMR(CDCl3)δ1.84(brs,6H),2.12(brs,6H),2.17(brs,3H),7.45(t,J=7.2Hz,1H),7.52-7.55(m ,4H),7.60-7.66(m,3H),7.72(d,J=8.4Hz,2H),7.75(dd,J=8.5,1.4Hz,2H),7.85(d,J=8.0Hz,4H ),8.84(dd,J=8.0,1.9Hz,2H),8.88(d,J=8.5Hz,2H),8.89(d,J=8.5Hz,2H).

[0158] Compound D81 had a Tg of 132°C and no Tc was detected.

[0159] <Synthesis Example 9 (D1)>

[0160] [ka] Under an argon atmosphere, 2-(biphenyl-4-yl)-4-chloro-6-phenyl-1,3,5-triazine (16.0 g, 46.5 mmol), 5,5-dimethyl-2-[4-(1-adamantyl)phenyl]-1,3,2-dioxaborinane (16.6 g, 51.2 mmol), and tetrakistriphenylphosphinepalladium (1.08 g, 0.931 mmol) were suspended in tetrahydrofuran (465 mL). To this suspension was added 2.0 M aqueous potassium phosphate solution (69.8 mL) and the mixture was heated to reflux for 16 hours. After cooling, water and methanol were added to the reaction mixture. The resulting solid was collected by filtration and purified by recrystallization from toluene to obtain the desired 2-(4-adamantylphenyl)-4-(4-biphenylyl)-6-phenyl-1,3,5-triazine (Compound D1) (19.5 g, yield 81%). 1 HNMR(CDCl3)δ1.85(brs,6H),2.04(brs,6H),2.18(brs,3H),7.44(t,d=7.2Hz,1H),7,53(t,d=7.5Hz,2H),7.59-7.65(m,5H), 7.74(dd,J=8.5,1.3Hz,2H),7.83(d,J=8.6Hz,2H),8.75(d,J=8.7Hz,2H),8.82(dd,J=8.0,1.8Hz,2H),8.87(d,J=8.6Hz,2H).

[0161] Synthesis Example 10 (D87)

[0162] [ka] In the same manner as in Synthesis Example 8, 2-(4'-adamantylbiphenyl-4-yl)-4,6-bis(4-biphenylyl)-1,3,5-triazine (compound D87) was obtained. 1HNMR(CDCl3)δ1.84(brs,6H),2.02(brs,6H),2.17(brs,3H),7.45(t,J=7.5Hz,2H),7.52-7.56( m,6H),7.72(d,J=8.6Hz,2H),7.75(dd,J=8.3,1.3Hz,4H),7.84-7.86(m,6H),8.88-8.91(m,6H).

[0163] Compound D87 had a Tg of 155°C and no Tc was detected.

[0164] Synthesis Example 11 (D175)

[0165] [ka] Under an argon atmosphere, 2-(4-chlorophenyl)-4,6-bis(4-biphenylyl)pyrimidine (2.00 g, 4.04 mmol), 5,5-dimethyl-2-[4-(1-adamantyl)phenyl]-1,3,2-dioxaborinane (1.31 g, 4.04 mmol), palladium acetate (18.1 mg, 0.081 mmol), and 2-dicyclohexylphosphino-2',4',6'-triisopropylbiphenyl (77.0 mg, 0.162 mmol) were suspended in tetrahydrofuran (40 mL). To this suspension was added 2.0 M aqueous potassium phosphate solution (6.1 mL) and the mixture was heated to reflux for 19 hours. After cooling, water and methanol were added to the reaction mixture. The resulting solid was collected by filtration and purified by recrystallization from toluene to obtain the desired 2-(4'-adamantylbiphenyl-4-yl)-4,6-bis(4-biphenylyl)pyrimidine (D175) (2.45 g, yield 90%). 1 HNMR(CDCl3)δ1.83(brs,6H),2.02(brs,6H),2.16(brs,3H),7.44(t,d=7.2Hz,2H),7.51-7.55(m,6 H),7.71-7.75(m,6H),7.82-7.85(m,6H),8.13(s,1H),8.44(d,J=8.6Hz,4H),8.84(d,J=8.4Hz,2H).

[0166] <Synthesis Example 12 (D7)>

[0167] [ka] Under an argon atmosphere, 2,4-bis(biphenyl-4-yl)-6-chloro-1,3,5-triazine (9.00 g, 21.4 mmol), 5,5-dimethyl-2-[4-(1-adamantyl)phenyl]-1,3,2-dioxaborinane (7.7 g, 23.6 mmol), and tetrakistriphenylphosphinepalladium (49.5 mg, 0.429 mmol) were suspended in tetrahydrofuran (214 mL). To this suspension, 2.0 M aqueous potassium phosphate solution (32.2 mL) was added and the mixture was heated to reflux for 23 hours. After cooling, water and methanol were added to the reaction mixture. The resulting solid was collected by filtration and purified by recrystallization from toluene to obtain the desired 2-(4-adamantylphenyl)-4,6-bis(4-biphenylyl)-1,3,5-triazine (Compound D7) (9.8 g, 77% yield). 1 HNMR(CDCl3)δ1.85(brs,6H),2.04(brs,6H),2.18(brs,3H),7.44(t,J=7.5Hz,2H),7.54(t,J=7.8Hz,4H),7.6 2(d,J=8.7Hz,2H),7.75(d,J=7.3Hz,4H),7.85(d,J=8.6Hz,4H),8.76(d,J=8.6Hz,2H),8.89(d,J=8.5Hz,4H).

[0168] Compound D7 had a Tg of 131°C and no Tc was detected.

[0169] <Synthesis Example 13 (ETL1)> ETL1 was synthesized by the method described in Example 8 of JP 2015-34159 A. The resulting compound had a Tg of 102°C and a Tc of 176°C.

[0170] [ka]

[0171] <Synthesis Example 14> ETL2 was synthesized by the method described in Example 22 of JP 2007-314503 A. The resulting compound had a Tg of 124°C and a Tc of 174°C.

[0172] [ka]

[0173] From the above results, it was confirmed that compounds D9, D8, D81, D87, and D7 have higher Tg than ETL1 and ETL2. Furthermore, since no crystallization peak was detected in these compounds, it is expected that a film structure having high amorphous properties will be formed during vapor deposition, which is presumably why the organic electroluminescent device, which is one embodiment of the present invention, exhibits high efficiency and long life.

[0174] <Example of organic electroluminescent device> An organic electroluminescent device was fabricated and its performance was evaluated. The materials used were purified by sublimation.

[0175] <Element Example 1>

[0176] An organic electroluminescent device 100 containing compound D158 was fabricated as follows (see FIG. 2).

[0177] (Prepare substrate 1 and anode 2) A glass substrate with an indium tin oxide (ITO) transparent electrode, on which a 2 mm wide striped pattern of an ITO film (thickness: 110 nm), was prepared as a substrate 1 having an anode 2 on its surface. Next, this substrate was washed with isopropyl alcohol, and then subjected to surface treatment by ozone ultraviolet cleaning.

[0178] (Preparation for vacuum deposition) After cleaning, each layer was deposited on the surface-treated substrate by vacuum deposition using a vacuum deposition method, and each layer was laminated.

[0179] First, the glass substrate was placed in a vacuum deposition chamber, and 1.0×10 -4 The pressure was reduced to 100 Pa. Then, each layer was formed in the following order according to the film formation conditions. Each organic material was formed by resistance heating.

[0180] (Fabrication of Hole Injection Layer 3) N-[1,1'-biphenyl]-4-yl-9,9-dimethyl-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9H-fluoren-2-amine and 1,2,3-tris[(4-cyano-2,3,5,6-tetrafluorophenyl)methylene]cyclopropane were mixed in a mass ratio of 99:1 to form a 10 nm film, thereby producing hole injection layer 3. The film formation rate was 0.1 nm / sec.

[0181] (Fabrication of First Hole Transport Layer 41) A first hole transport layer 41 was prepared by depositing N-[1,1′-biphenyl]-4-yl-9,9-dimethyl-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9H-fluoren-2-amine to a thickness of 85 nm at a rate of 0.2 nm / sec.

[0182] (Fabrication of the second hole transport layer 42) A film of N-phenyl-N-(9,9-diphenylfluoren-2-yl)-N-(1,1′-biphenyl-4-yl)amine was formed to a thickness of 5 nm at a rate of 0.15 nm / second to form a second hole transport layer 42 .

[0183] (Fabrication of Light-Emitting Layer 5) A 20 nm thick film of 3-(10-phenyl-9-anthryl)-dibenzofuran and 2,7-bis[N,N-di-(4-tertbutylphenyl)]amino-bisbenzofurano-9,9′-spirofluorene was formed in a mass ratio of 95:5 to prepare the light-emitting layer 5. The film formation rate was 0.1 nm / sec.

[0184] (Fabrication of Hole Blocking Layer 9) A hole blocking layer 9 was prepared by depositing 2-[3'-(9,9-dimethyl-9H-fluoren-2-yl)[1,1'-biphenyl]-3-yl]-4,6-diphenyl-1,3,5-triazine to a thickness of 6 nm at a rate of 0.05 nm / sec.

[0185] (Fabrication of Electron Transport Layer 6) 2-(4'-adamantylbiphenyl-4-yl)-4-(4-adamantylphenyl)-6-(4-biphenylyl)-1,3,5-triazine (Compound D158) synthesized in Synthesis Example 4 and 8-hydroxyquinolinolato-lithium (hereinafter referred to as Liq) were mixed in a mass ratio of 50:50 to form a 25 nm film, thereby producing an electron transport layer 6. The film formation rate was 0.15 nm / sec.

[0186] (Fabrication of Electron Injection Layer 7) An electron injection layer 7 was formed by depositing Yb to a thickness of 1 nm at a rate of 0.02 nm / second.

[0187] (Fabrication of cathode 8) Finally, a metal mask was placed perpendicular to the ITO stripes (anode 2) on the substrate 1, and a cathode 8 was formed. The cathode had a two-layer structure, with silver / magnesium (mass ratio 1 / 10) and silver deposited in that order to thicknesses of 80 nm and 20 nm, respectively. The silver / magnesium deposition rate was 0.5 nm / sec, and the silver deposition rate was 0.2 nm / sec.

[0188] As a result, the light-emitting area of ​​4mm as shown in Figure 2 2 Thus, an organic electroluminescent device 100 was produced. The thickness of each film was measured using a stylus film thickness measuring instrument (DEKTAK, manufactured by Bruker).

[0189] The device was then sealed in a nitrogen atmosphere glove box with an oxygen and moisture concentration of 1 ppm or less by sealing the glass sealing cap and the film-formed substrate (device) with bisphenol F epoxy resin (manufactured by Nagase ChemteX Corporation).

[0190] <Element Example 2> An organic electroluminescent device was prepared in the same manner as in Device Example 1, except that, instead of forming a 25 nm film (film formation rate: 0.15 nm / sec) of 2-(4'-adamantylbiphenyl-4-yl)-4-(4-adamantylphenyl)-6-(4-biphenylyl)-1,3,5-triazine (Compound D158) and Liq in a 50:50 (mass ratio) as the electron transport layer 6, a 25 nm film (film formation rate: 0.15 nm / sec) of 2-(4-adamantylphenyl)-4-(4-biphenylyl)-6-{4-(1-naphthyl)phenyl}-1,3,5-triazine (Compound D9) synthesized in Synthesis Example 5 and Liq in a 50:50 (mass ratio) was formed.

[0191] <Element Example 3> An organic electroluminescent device was prepared in the same manner as in Device Example 1, except that, instead of forming a 25 nm film (film formation rate: 0.15 nm / sec) of 2-(4'-adamantylbiphenyl-4-yl)-4-(4-adamantylphenyl)-6-(4-biphenylyl)-1,3,5-triazine (Compound D158) and Liq in a 50:50 (mass ratio) as the electron transport layer 6, a 25 nm film (film formation rate: 0.15 nm / sec) of 2-(4-adamantylphenyl)-4-(4-biphenylyl)-6-{4-(2-naphthyl)phenyl}-1,3,5-triazine (Compound D8) synthesized in Synthesis Example 7 and Liq in a 50:50 (mass ratio) was formed.

[0192] <Element Example 4> An organic electroluminescent device was prepared in the same manner as in Device Example 1, except that, instead of forming a 25 nm film (film formation rate: 0.15 nm / sec) of 2-(4'-adamantylbiphenyl-4-yl)-4-(4-adamantylphenyl)-6-(4-biphenylyl)-1,3,5-triazine (Compound D158) and Liq in a 50:50 (mass ratio) as the electron transport layer 6, a 25 nm film (film formation rate: 0.15 nm / sec) of 2-(4'-adamantylbiphenyl-4-yl)-4-(4-biphenylyl)-6-phenyl-1,3,5-triazine (Compound D81) synthesized in Synthesis Example 8 and Liq in a 50:50 (mass ratio) was formed.

[0193] <Element Example 5> An organic electroluminescent device was prepared in the same manner as in Device Example 1, except that, instead of forming a 25 nm film (film formation rate: 0.15 nm / sec) of 2-(4'-adamantylbiphenyl-4-yl)-4-(4-adamantylphenyl)-6-(4-biphenylyl)-1,3,5-triazine (Compound D158) and Liq in a 50:50 (mass ratio) as the electron transport layer 6, a 25 nm film (film formation rate: 0.15 nm / sec) of 2-(4-adamantylphenyl)-4-(4-biphenylyl)-6-phenyl-1,3,5-triazine (Compound D1) synthesized in Synthesis Example 9 and Liq in a 50:50 (mass ratio) was formed.

[0194] <Element Example 6> An organic electroluminescent device was prepared in the same manner as in Device Example 1, except that, instead of forming a 25 nm film (film formation rate: 0.15 nm / sec) of 2-(4'-adamantylbiphenyl-4-yl)-4-(4-adamantylphenyl)-6-(4-biphenylyl)-1,3,5-triazine (Compound D158) and Liq in a 50:50 (mass ratio) as the electron transport layer 6, a 25 nm film (film formation rate: 0.15 nm / sec) of 2-(4'-adamantylbiphenyl-4-yl)-4,6-bis(4-biphenylyl)-1,3,5-triazine (Compound D87) synthesized in Synthesis Example 10 and Liq in a 50:50 (mass ratio) was formed.

[0195] <Element Example 7> An organic electroluminescent device was produced in the same manner as in Device Example 1, except that, instead of forming a 25 nm film (film formation rate: 0.15 nm / sec) of 2-(4'-adamantylbiphenyl-4-yl)-4-(4-adamantylphenyl)-6-(4-biphenylyl)-1,3,5-triazine (Compound D158) and Liq in a 50:50 (mass ratio) as the electron transport layer 6, a 25 nm film (film formation rate: 0.15 nm / sec) of 2-(4-adamantylphenyl)-4,6-bis(4-biphenylyl)-1,3,5-triazine (Compound D7) synthesized in Synthesis Example 12 and Liq in a 50:50 (mass ratio) was formed.

[0196] <Element Example 8> An organic electroluminescent device was prepared in the same manner as in Device Example 1, except that, instead of forming a 25 nm film (film formation rate: 0.15 nm / sec) of 2-(4'-adamantylbiphenyl-4-yl)-4-(4-adamantylphenyl)-6-(4-biphenylyl)-1,3,5-triazine (Compound D158) and Liq in a 50:50 (mass ratio) as the electron transport layer 6, a 25 nm film (film formation rate: 0.15 nm / sec) of 2-(4'-adamantylbiphenyl-4-yl)-4,6-bis(4-biphenylyl)pyrimidine (Compound D175) synthesized in Synthesis Example 11 and Liq in a 50:50 (mass ratio) was formed.

[0197] <Comparative element example 1> An organic electroluminescent device was produced in the same manner as in Device Example 1, except that, instead of forming a 25 nm film (film formation rate: 0.15 nm / sec) of 2-(4'-adamantylbiphenyl-4-yl)-4-(4-adamantylphenyl)-6-(4-biphenylyl)-1,3,5-triazine (Compound D158) and Liq in a mass ratio of 50:50 as the electron transport layer 6, a 25 nm film (film formation rate: 0.15 nm / sec) of ETL-2 synthesized in Synthesis Example 14 and Liq in a mass ratio of 50:50 was formed.

[0198] <Evaluation of organic EL elements> A direct current was applied to the fabricated organic electroluminescent device, and the luminescence characteristics were evaluated using a luminance meter of LUMINANCE METER (BM-9) manufactured by TOPCON Corporation.

[0199] As the luminescence characteristics, the voltage (V) and power efficiency (lm / A) when a current density of 10 mA / cm 2 was passed were measured, and the device lifetime during continuous lighting was measured. The device lifetime was measured as the luminance decay time during continuous lighting when driven at an initial luminance of 1000 cd / m 2 , and the time required until the luminance (cd / m 2 ) decreased by 5% was measured. The values of voltage, power efficiency, and lifetime were represented as relative values when the value of Comparative Example 1 of the device was 100. The results are shown in Table 1. The measurement was carried out in an atmosphere of 23°C and 50% RH. A smaller voltage value indicates better performance, and larger efficiency and lifetime values indicate better performance, respectively.

[0200]

Table 1

[0201] From Table 1, it can be seen that compared with Comparative Example 1 of the device, the organic electroluminescent devices according to Examples 1 to 8 using the adamantane compound (1) according to the embodiment of the present invention have improved characteristics in terms of voltage, current efficiency, and device lifetime.

[0202] <EOD Evaluation> In improving the performance of organic electroluminescent devices, electron mobility is an important factor. For example, the higher the electron mobility in the electron transport layer, the more electrons can be injected into the light-emitting layer, which can contribute to improving the efficiency and reducing the voltage of the device. Therefore, in order to investigate the mobility (electron mobility) of the above compound, an EOD (Electron Only Device) was manufactured and evaluated.

[0203] Specifically, the above compounds were used to produce EODs (Element Examples 11 to 18 and Element Comparative Example 11), respectively. Also, an EOD was produced using the compound ETL1 according to Synthesis Example 13 (Element Example 19).

[0204] For each EOD produced, the voltage (V) at a specific current was measured. The smaller this voltage (EOD voltage), the higher the electron mobility of the compound. The voltage value was expressed as a relative value, with the value of Device Example 19 being 100.

[0205] More detailed manufacturing and evaluation procedures are shown below.

[0206] Using the compounds (subject compounds) shown in Table 2 below, EODs having the following device configuration were manufactured by depositing each layer on an ITO substrate in the order starting with Ag: ITO / Ag (thickness: 10 nm) / Liq (thickness: 1 nm) / Target compound:Liq = 50:50 (thickness: 70 nm) / Yb (thickness: 1 nm) / AgMg (80 nm) In this EOD, the flow of holes is blocked by Ag / Liq deposited on the ITO.

[0207] For each EOD fabricated, a current density of 10 mA / cm 2 The voltage (EOD voltage) was measured when the current was applied. The results are shown in Table 2 below.

[0208] [Table 2]

[0209] As can be seen from Table 2, all of Device Examples 11 to 18 exhibited lower EOD voltages compared to Device Example 19. This result indicates that the compounds according to Device Examples 11 to 18 have higher electron mobility than the compound according to Device Example 19. The compounds according to Device Examples 11 to 18 have Z 1 , Z 2 , and Z 3The compound has an aromatic hydrocarbon ring bonded at the para position to a benzene ring bonded to an aromatic ring (particularly a heteroaromatic ring such as triazine or pyrimidine) having the following structure:

[0063] While not intending to be limited by theory, it is believed that this structure causes the LUMO of the compound to spread over a wide range, resulting in a higher electron mobility than the compound of Device Example 19, which does not have such a structure.

[0210] This is also confirmed by comparing Device Example 19 with Device Comparative Example 11. That is, the compound (ETL2) of Device Comparative Example 11 also has a Z 1 , Z 2 , and Z 3 The aromatic hydrocarbon ring (benzene ring) is bonded at the para position to the benzene ring bonded to the aromatic ring having the formula (I), and exhibited relatively high electron mobility.

[0211] According to the results in Table 2, compound ETL2 has a higher electron mobility than the compounds of the Examples. However, according to the results in Table 1, the organic electroluminescent device fabricated using compound ETL2 exhibited inferior performance compared to the compounds of the Examples. The reason for this is that while a structure having a para-conjugated aromatic hydrocarbon ring provides high electron mobility, it also generates a deep LUMO energy level, which can cause an increase in resistance at the interface between adjacent layers in the device. Without intending to be limited by theory, it is believed that the increased resistance is so significant that the organic electroluminescent device fabricated using compound ETL2 fails to achieve sufficient organic electroluminescent device performance.

[0212] In contrast, unlike compound ETL2, the compounds of the present disclosure according to Device Examples 1 to 8 in Table 1 have adamantyl groups at the terminals, which is believed to avoid or compensate for the above-mentioned disadvantages due to the deep LUMO energy level. While not intending to be limited by theory, in the compounds according to Device Examples 1 to 8, the sterically bulky adamantyl groups may suppress exciton deactivation at the interface between adjacent layers in the device. More specifically, for example, if an intermediate such as an exciplex is generated by interaction between the light-emitting layer and the electron-transporting layer, the energy of the exciton is deactivated, which can cause a decrease in luminous efficiency. However, the bulky adamantyl groups are believed to be advantageous in suppressing the formation of such exciplexes. [Industrial Applicability]

[0213] The adamantane compound (1) according to the embodiment of the present invention is a novel adamantane compound having high amorphous properties and excellent heat resistance. Therefore, the adamantane compound (1) has good thermal stability during sublimation purification, making it easy to operate, and can provide a material with few impurities.

[0214] In addition, the adamantane compound (1) according to another embodiment of the present invention is used as an electron transport material for an organic electroluminescent device having excellent low driving voltage. Furthermore, according to the present invention, an organic electroluminescent device having excellent power consumption can be provided.

[0215] Furthermore, the adamantane compound (1) according to another embodiment of the present invention can provide an organic electroluminescent device with a long life due to excellent stability of the vapor-deposited film.

[0216] A thin film comprising the adamantane compound (1) according to another embodiment of the present invention is excellent in electron transporting ability, hole blocking ability, oxidation-reduction resistance, water resistance, oxygen resistance, electron injection properties, etc., and is therefore useful as a material for organic electroluminescent devices, particularly as an electron transporting material, hole blocking material, luminescent host material, etc. Furthermore, the adamantane compound (1) according to an embodiment of the present invention is a wide band gap compound, and therefore can be suitably used not only in fluorescent devices but also in phosphorescent devices. [Explanation of symbols]

[0217] 1. Glass substrate 2. Anode 3. Hole injection layer 4. Hole transport layer 41. First hole transport layer 42. Second hole transport layer 5. Emitting layer 9. Hole-blocking layer 6. Electron transport layer 7. Electron injection layer 8. Cathode 100. Organic electroluminescent devices

Claims

1. Adamantane compound represented by general formula (1-1): 【Chemical 1】 During the ceremony, R 1 represents a phenyl group or a naphthyl group; R 2 represents a hydrogen atom or a phenyl group; R 3 represents a single bond or a phenylene group; When R 1 , R 2 , and R 3 are each an aromatic hydrocarbon group, they are unsubstituted or substituted with one or more substituents selected from the group consisting of one or more phenyl groups, naphthyl groups, phenanthryl groups, anthryl groups, terphenyl groups, methyl groups, tert-butyl groups, fluoro groups, and deuterium groups; Ad represents a 1-adamantyl group or a 2-adamantyl group; e=0 or 1; f = 1; Z 1 , Z 2 and Z 3 each independently represent a nitrogen atom or C—H, and two or more of Z 1 , Z 2 and Z 3 are nitrogen atoms.

2. Z １ , Z ２ and Z ３ The adamantane compound according to claim 1 , wherein two or more of the

3. Z １ , Z ２ and Z ３ The adamantane compound according to claim 1 or 2, wherein two of the groups are nitrogen atoms and one is C—H.

4. R １ , R ２ and R ３ and each, when an aromatic hydrocarbon group, is unsubstituted.

5. Organic electroluminescent device containing an adamantane compound represented by general formula (1-1): 【Chemistry 2】 During the ceremony, R 1 represents a phenyl group or a naphthyl group; R 2 represents a hydrogen atom or a phenyl group; R 3 represents a single bond or a phenylene group; When R 1 , R 2 , and R 3 are each an aromatic hydrocarbon group, they are unsubstituted or substituted with one or more substituents selected from the group consisting of one or more phenyl groups, naphthyl groups, phenanthryl groups, anthryl groups, terphenyl groups, methyl groups, tert-butyl groups, fluoro groups, and deuterium groups; Ad represents a 1-adamantyl group or a 2-adamantyl group; e=0 or 1; f = 1; Z 1 , Z 2 and Z 3 each independently represent a nitrogen atom or C—H, and two or more of Z 1 , Z 2 and Z 3 are nitrogen atoms.

6. 6. The organic electroluminescent device according to claim 5, wherein the layer containing the adamantane compound represented by the general formula (1-1) is an electron transport layer.

7. 7. The organic electroluminescent device according to claim 5, wherein the organic electroluminescent device is doped with the adamantane compound represented by the general formula (1-1).

8. The organic electroluminescent device according to claim 7 , wherein the dopant is Liq.

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