Fused diamantane compound, material for organic electroluminescent element, and organic electroluminescent element

Abstract

To provide a compound suitable for forming an organic electroluminescent element that can reduce a driving voltage.SOLUTION: There is provided a fused diamantane compound having a group represented by the following formula (1) and formula (2). (In the formula (1), * represents a bonding site, and a represents an integer from 1 to 6. Each of ring A and ring B independently represents (i) an optionally substituted aromatic hydrocarbon group having 6 to 60 carbon atoms, or (ii) an optionally substituted heteroaromatic group having 3 to 60 carbon atoms). (In the formula (2), * represents a bonding site, and b represents an integer from 1 to 6. Ar independently represents (I) an optionally substituted aromatic hydrocarbon group having 6 to 60 carbon atoms, (II) an optionally substituted heteroaromatic group having 3 to 60 carbon atoms, (III) an optionally substituted nitrogen atom, or (IV) a group formed by combining any of the groups (I) to (III)).SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a fused diamantane compound, a material for an organic electroluminescent device containing the fused diamantane compound, and an organic electroluminescent device. [Background technology]

[0002] Organic electroluminescent devices have started to be put to practical use, mainly for small mobile applications. However, to further expand their applications, performance improvement is essential, and materials with low driving voltage, high luminous efficiency, and long life characteristics are required. Patent Documents 1 and 2 disclose diamantane compounds that are materials for organic electroluminescent devices. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP2011-530802A [Patent Document 2] International Publication No. WO2017 / 047993 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the diamantane compounds disclosed in Patent Documents 1 and 2 do not sufficiently satisfy the driving voltage characteristics and luminous efficiency characteristics.

[0005] Therefore, one aspect of the present invention is directed to providing a new fused diamantane compound that contributes to the formation of an organic electroluminescence device that can reduce the driving voltage and improve the luminous efficiency.

[0006] Yet another aspect of the present invention is directed to providing an organic electroluminescent device with reduced driving voltage and improved luminous efficiency. [Means for solving the problem]

[0007] A fused diamantane compound according to one embodiment of the present invention is a fused diamantane compound represented by formula (1): A fused ring diamantane compound having groups represented by the following formula (1) and formula (2):

[0008] [ka]

[0009] In formula (1), the carbon atom in the diamantane ring may be substituted with an aryl group having 6 to 12 carbon atoms. In formula (1), * represents a bond. a represents an integer of 1 to 6.

[0010] Ring A and ring B in formula (1) are each independently (i) an aromatic hydrocarbon group having 6 to 60 carbon atoms which may be substituted, or (ii) an optionally substituted heteroaromatic group having 3 to 60 carbon atoms, In the above (i) and (ii), the carbon atoms other than the carbon atom having the bond marked with * may have a substituent.

[0011] [ka]

[0012] In formula (2), * represents a bond, and b represents an integer of 1 to 6.

[0013] In formula (2), each Ar is independently (I) an aromatic hydrocarbon group having 6 to 60 carbon atoms which may be substituted, (II) an optionally substituted heteroaromatic group having 3 to 60 carbon atoms, (III) an optionally substituted nitrogen atom, or (IV) a group obtained by combining the groups (I) to (III) above, Shows.

[0014] An organic electroluminescent device according to another aspect of the present invention comprises: An anode; A cathode; and one or more organic thin film layers including at least a light-emitting layer; At least one of the organic thin film layers contains the fused diamantane compound. Effect of the Invention

[0015] According to one embodiment of the present invention, it is possible to provide a novel fused diamantane compound that contributes to the formation of an organic electroluminescent device capable of reducing the driving voltage.

[0016] According to another aspect of the present invention, there can be provided a material for an organic electroluminescent device, which contains the above-mentioned fused diamantane compound, and an electron transport material for an organic electroluminescent device. Furthermore, according to yet another aspect of the present invention, there can be provided an organic electroluminescent device having a reduced driving voltage. [Brief description of the drawings]

[0017] [Figure 1] FIG. 1 is a schematic cross-sectional view showing an example of a layered structure of an organic electroluminescence element according to one embodiment of the present disclosure. [Diagram 2] FIG. 2 is a schematic cross-sectional view showing another example of a laminate structure (structure of Element Example 1) of an organic electroluminescence element according to one embodiment of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] Each aspect of the present invention will be described in detail below. In this specification, a numerical range indicated using "~" indicates a range including the numerical values ​​before and after "~" as the minimum and maximum values, respectively. In addition, unless specifically stated otherwise, the units of the numerical values ​​before and after "~" are the same.

[0019] A fused diamantane compound according to one embodiment of the present invention is a fused diamantane compound having groups represented by formula (1) and formula (2).

[0020] [ka]

[0021] In formula (1), the carbon atom in the diamantane ring may be substituted with an aryl group having 6 to 12 carbon atoms. In formula (1), * represents a bond. a represents an integer of 1 to 6.

[0022] Ring A and ring B in formula (1) are each independently (i) an aromatic hydrocarbon group having 6 to 60 carbon atoms, or (ii) a heteroaromatic group having 3 to 60 carbon atoms, In the above (i) and (ii), the carbon atoms other than the carbon atom having the bond marked with * may have a substituent.

[0023] [ka]

[0024] In formula (2), * represents a bond, and b represents an integer of 1 to 6. In formula (2), each Ar is independently (I) an aromatic hydrocarbon group having 6 to 60 carbon atoms which may be substituted, (II) an optionally substituted heteroaromatic group having 3 to 60 carbon atoms, (III) an optionally substituted nitrogen atom, or (IV) a group obtained by combining the groups (I) to (III) above, Shows. [Fused ring diamantane in formula (1)] In the fused diamantane skeleton in formula (1), among the carbon atoms constituting ring A and ring B, the carbon atom having the bond represented by * is not particularly limited, and any carbon atom constituting ring A and ring B in the fused diamantane skeleton structure represented by formula (1) may have the bond represented by *. In addition, in the fused diamantane skeleton in formula (1), the number of carbon atoms bonded to the bond represented by * is not particularly limited, and multiple carbon atoms in the fused diamantane skeleton in formula (1) may have the bond represented by *.

[0025] As described above, in the fused diamantane skeleton in formula (1), the carbon atoms constituting the diamantane ring may be substituted with an aryl group having 6 to 12 carbon atoms. Examples of the aryl group as a substituent include a phenyl group, a naphthyl group, and a biphenyl group. However, in the present invention, from the viewpoints of availability and ease of preparation, it is preferable that the carbon atoms other than the carbon atom bonded to the Ar group in the diamantane ring in formula (1) are not substituted with an aryl group. [Ring A and Ring B in Formula (1)] Ring A and ring B are (i) an aromatic hydrocarbon group having 6 to 60 carbon atoms, or (ii) a heteroaromatic group having 3 to 60 carbon atoms, In the above (i) and (ii), the carbon atoms other than the carbon atom having the bond marked with * may have a substituent.

[0026] The aromatic hydrocarbon group (i) and the heteroaromatic group (ii) may each be in the form of a single ring, a condensed ring, or a linked ring in which any ring selected from these rings is linked.

[0027] Examples of the aromatic hydrocarbon group having 6 to 60 carbon atoms in (i) include a phenyl group, a naphthyl group, a phenanthryl group, an anthryl group, a pyrenyl group, a perylenyl group, a fluorenyl group, a dimethylfluorenyl group, a diphenylfluorenyl group, a triphenylenyl group, a fluoranthenyl group, a benzofluoranthenyl group, a chrysenyl group, a dibenzochrysenyl group, and a dinaphthochrysenyl group. A fused ring aromatic hydrocarbon group having 14 to 60 carbon atoms is preferred in that it has a high glass transition temperature.

[0028] The heteroaromatic group of (ii) above is preferably, for example, a heteroaromatic group containing any one of a nitrogen atom, an oxygen atom, and a sulfur atom, and among these, a heteroaromatic group containing a nitrogen atom is more preferable.

[0029] Examples of the heteroaromatic group having 3 to 60 carbon atoms in (ii) include a pyridyl group, a pyrimidyl group, a pyrazyl group, a triazinyl group, a quinolyl group, an isoquinolyl group, a nadithyridinyl group, an acridinyl group, a phenanthrolinyl group, a phenanthridinyl group, a pyrrolyl group, an indolyl group, an indolizinyl group, a carbazolyl group, a carbolinyl group, a benzocarbazolyl group, a benzocarbolinyl group, a furanyl group, a benzofuranyl group, a dibenzofuranyl group, a xanthenyl group, a spiroxanthenyl group, a benzoxanthenyl group, a thienyl group, a benzothienyl group, a dibenzothienyl group, an oxazolyl group, a benzoxazolyl group, a thiazolyl group, and a benzothiazyl group.

[0030] Examples of the substituent in the optionally substituted aromatic hydrocarbon group of (i) and the optionally substituted heteroaromatic group of (ii) include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a formyl group, a cyano group, a nitro group, an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 1 to 20 carbon atoms, a cycloalkyl group having 1 to 20 carbon atoms, a bicycloalkyl group having 1 to 20 carbon atoms, a tricycloalkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, P(═O)(Ar 2 ) 2 , C(=O)Ar 2, B(Ar 2 ) 2 , B(OAr 2 ) 2 , O.S.O. 2 Ar 2 , S(=O)Ar 2 , Si(Ar 2 ) 3 , P(=S)(Ar 2 ) 2 , and C(=C(CN) 2 )Ar 2 2 Examples of the groups include groups selected from the group consisting of:

[0031] Here, the above Ar 2 are each independently a group selected from the group consisting of an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 60 carbon atoms, and a heteroaromatic group having 3 to 60 carbon atoms.

[0032] Ring A and ring B in the above formula (1) preferably have a group selected from the group consisting of a phenyl group, a naphthyl group, an azabenzofluoranthenyl group, a fluoranthenyl group, and a benzofluoranthenyl group. [Ar in formula (2)] Ar is independently (I) an aromatic hydrocarbon group having 6 to 60 carbon atoms which may be substituted, (II) an optionally substituted heteroaromatic group having 3 to 60 carbon atoms, (III) an optionally substituted nitrogen atom, or (IV) a group obtained by combining the groups (I) to (III) above, Shows.

[0033] The aromatic hydrocarbon group of (I) above and the heteroaromatic group of (II) above may each be a single ring, a condensed ring, or a linked ring.

[0034] The group represented by (IV) above represents a group in which a plurality of groups selected from the groups represented by (I) to (III) above are linked in a linear or branched chain.

[0035] Examples of the aromatic hydrocarbon group having 6 to 60 carbon atoms in (I) include a phenyl group, a naphthyl group, a phenanthryl group, an anthryl group, a pyrenyl group, a perylenyl group, a fluorenyl group, a dimethylfluorenyl group, a diphenylfluorenyl group, a triphenylenyl group, a fluoranthenyl group, a benzofluoranthenyl group, a chrysenyl group, a dibenzochrysenyl group, and a dinaphthochrysenyl group. A fused ring aromatic hydrocarbon group having 14 to 60 carbon atoms is preferred in that it has a high glass transition temperature.

[0036] The heteroaromatic group of (II) above is preferably, for example, a heteroaromatic group containing any one of a nitrogen atom, an oxygen atom, and a sulfur atom, and among these, a heteroaromatic group containing a nitrogen atom is more preferable.

[0037] Examples of the heteroaromatic group having 3 to 60 carbon atoms in (II) include a pyridyl group, a pyrimidyl group, a pyrazyl group, a triazinyl group, a quinolyl group, an isoquinolyl group, a nadithyridinyl group, an acridinyl group, a phenanthrolinyl group, a phenanthridinyl group, a pyrrolyl group, an indolyl group, an indolizinyl group, a carbazolyl group, a carbolinyl group, a benzocarbazolyl group, a benzocarbolinyl group, a furanyl group, a benzofuranyl group, a dibenzofuranyl group, a xanthenyl group, a spiroxanthenyl group, a benzoxanthenyl group, a thienyl group, a benzothienyl group, a dibenzothienyl group, an oxazolyl group, a benzoxazolyl group, a thiazolyl group, and a benzothiazyl group.

[0038] Examples of the substituent in the optionally substituted aromatic hydrocarbon group of (I), the optionally substituted heteroaromatic group of (II), and the optionally substituted nitrogen atom of (III) include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a formyl group, a cyano group, a nitro group, an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 1 to 20 carbon atoms, a cycloalkyl group having 1 to 20 carbon atoms, a bicycloalkyl group having 1 to 20 carbon atoms, a tricycloalkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, P(═O)(Ar 2 ) 2, C(=O)Ar 2 , B(Ar 2 ) 2 , B(OAr 2 ) 2 , O.S.O. 2 Ar 2 , S(=O)Ar 2 , Si(Ar 2 ) 3 , P(=S)(Ar 2 ) 2 , and C(=C(CN) 2 )Ar 2 2 Examples of the groups include groups selected from the group consisting of:

[0039] Here, the above Ar 2 are each independently a group selected from the group consisting of an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 60 carbon atoms, and a heteroaromatic group having 3 to 60 carbon atoms.

[0040] As Ar in the above formula (2), The optionally substituted nitrogen atom of (III), and The above (I) aromatic hydrocarbon group having 6 to 60 carbon atoms which may be substituted, or the above (II) heteroaromatic group having 3 to 60 carbon atoms which may be substituted, It is preferable that the ion exchange layer 100 is constituted by the following formula:

[0041] Preferred embodiments of the fused diamantane compound of the present invention having groups represented by the above formulas (1) and (2) include a fused diamantane compound represented by the following first aspect or a fused diamantane compound represented by the following second aspect.

[0042] The fused diamantane compound represented by the first embodiment and the fused diamantane compound represented by the second embodiment will each be described below. [First aspect] A preferred embodiment of the fused diamantane compound of the present invention is a fused diamantane compound represented by the following formula (3).

[0043] [ka]

[0044] The carbon atom in the diamantane ring in formula (3) may be substituted with an aryl group having 6 to 12 carbon atoms.

[0045] In formula (3), ring A and ring B each independently represent (i) an aromatic hydrocarbon group having 6 to 60 carbon atoms, or (ii) a heteroaromatic group having 3 to 60 carbon atoms, In the above (i) and (ii), the carbon atoms other than the carbon atom bonded to the Ar group may have a substituent.

[0046] In formula (3), each Ar is independently (I) an aromatic hydrocarbon group having 6 to 60 carbon atoms which may be substituted, (II) an optionally substituted heteroaromatic group having 3 to 60 carbon atoms, (III) an optionally substituted nitrogen atom, or (IV) a group obtained by combining the groups (I) to (III), Shows.

[0047] In the formula (3), m represents an integer of 1 to 6.

[0048] Further, preferred embodiments of the fused diamantane compound represented by the above formula (3) include fused diamantane compounds represented by any of the following formulas (5-1) to (5-3).

[0049] [ka]

[0050] [ka]

[0051] [ka]

[0052] The carbon atoms in the diamantane ring in the formulas (5-1) to (5-3) may be substituted with an aryl group having 6 to 12 carbon atoms.

[0053] Ring A and ring B in formulae (5-1) to (5-3) are each independently (i) an aromatic hydrocarbon group having 6 to 60 carbon atoms, or (ii) a heteroaromatic group having 3 to 60 carbon atoms, In the above (i) and (ii), the carbon atoms other than the carbon atom bonded to the Ar group may have a substituent.

[0054] In the formulas (5-1) to (5-3), Ar is each independently (I) an aromatic hydrocarbon group having 6 to 60 carbon atoms which may be substituted, (II) an optionally substituted heteroaromatic group having 3 to 60 carbon atoms, (III) an optionally substituted nitrogen atom, or (IV) a group obtained by combining the groups (I) to (III), Shows.

[0055] In the above formula (3) and the above formulas (5-1) to (5-3), the explanation of the diamantane ring, ring A and ring B, and the Ar group is as described in the above columns of [Fused diamantane in formula (1)], [Ring A and ring B in formula (1)], and [Ar in formula (2)]. [Second aspect] A preferred embodiment of the fused diamantane compound of the present invention is a fused diamantane compound represented by the following formula (4).

[0056] [ka]

[0057] The carbon atom in the diamantane ring in formula (4) may be substituted with an aryl group having 6 to 12 carbon atoms.

[0058] In formula (4), ring A and ring B each independently represent (i) an aromatic hydrocarbon group having 6 to 60 carbon atoms, or (ii) a heteroaromatic group having 3 to 60 carbon atoms, In the above (i) and (ii), the carbon atoms other than the carbon atom bonded to the Ar group may have a substituent. In formula (4), each Ar is independently (I) an aromatic hydrocarbon group having 6 to 60 carbon atoms which may be substituted, (II) an optionally substituted heteroaromatic group having 3 to 60 carbon atoms, (III) an optionally substituted nitrogen atom, or (IV) a group obtained by combining the groups (I) to (III), Shows.

[0059] In the formula (4), n represents an integer of 2 or 3.

[0060] In the above formula (4), the diamantane ring, ring A and ring B, and Ar group are as described above in the sections [Fused diamantane in formula (1)], [Ring A and ring B in formula (1)], and [Ar in formula (2)].

[0061] The molecular weight of the diamantane compound of the present invention was determined by mass spectrometry, and the molecular weight is preferably 300 to 1200, and more preferably 400 to 900. A fused ring diamantane compound having a molecular weight within the above range has a high glass transition point and is highly stable even when repeatedly subjected to electrical oxidation and reduction. Therefore, by using the diamantane compound of the present invention having a desired molecular weight as a material for an organic electroluminescent device, it is possible to provide an organic electroluminescent device that can achieve even higher levels of driving voltage characteristics and luminous efficiency characteristics. [Specific examples of diamantane compounds] Specific examples of the fused diamantane compound are shown below, but the present invention is not limited thereto.

[0062] [ka]

[0063] [ka]

[0064] [ka]

[0065] [ka]

[0066] The fused diamantane compound according to one embodiment of the present invention can be used for organic electronic devices such as organic electroluminescent devices and photoelectric devices. <Materials for organic electroluminescence devices> A material for an organic electroluminescent device according to an embodiment of the present invention contains a fused diamantane compound according to an embodiment of the present invention.

[0067] The fused diamantane compound of the present invention can be used, for example, as an electron transport material for an organic electroluminescent device.

[0068] The structural reasons why the fused diamantane compound according to one embodiment of the present invention exhibits a low driving voltage when used, for example, as an electron transport material for an organic electroluminescent device are presumed to be as follows. <Materials for organic electroluminescence devices> The diamantane compound is useful as a material for an organic electroluminescence device. The diamantane compound can be used, for example, as an electron transport material for an organic electroluminescence device or as a hole transport material for an organic electroluminescence device. The material for an organic electroluminescence device containing the diamantane compound exhibits high luminous efficiency, more preferably low driving voltage and high luminous efficiency, and can produce an organic electroluminescence device that can be used for various purposes or under various environments. <Organic electroluminescent device> An organic electroluminescent device according to one embodiment of the present invention (hereinafter, may be simply referred to as an organic electroluminescent device) will be described below.

[0069] The organic electroluminescent device according to one embodiment of the present invention contains the fused diamantane compound according to one embodiment of the present invention.

[0070] The configuration of the organic electroluminescent device is not particularly limited, but examples thereof include the following configurations (a) to (g).

[0071] (a): Anode / light-emitting layer / cathode (b): Anode / hole transport layer / light emitting layer / cathode (c): Anode / light-emitting layer / electron transport layer / cathode (d): Anode / hole transport layer / light emitting layer / electron transport layer / cathode (e): Anode / hole injection layer / hole transport layer / light emitting layer / electron transport layer / electron injection layer / cathode (f): Anode / hole injection layer / hole transport layer / electron blocking layer / light emitting layer / hole blocking layer / electron transport layer / electron injection layer / cathode (g): Anode / hole injection layer / first hole transport layer / second hole transport layer / light emitting layer / first electron transport layer / second electron transport layer / cathode The fused diamantane compound according to one embodiment of the present invention may be contained in any of the layers described above. In terms of excellent light-emitting properties of the organic electroluminescent device, in one embodiment, it is preferable that the compound is contained in one or more layers selected from the group consisting of an emission layer and a layer between the emission layer and a cathode.

[0072] Alternatively, in another embodiment, it is preferably contained in one or more layers selected from the group consisting of the light-emitting layer and the layer between the light-emitting layer and the anode.

[0073] Therefore, in the case of the configurations shown in (a) to (e) above, in one embodiment, the fused diamantane compound is preferably contained in one or more layers selected from the group consisting of an emitting layer, an electron transport layer, and an electron injection layer.

[0074] Alternatively, in the above other embodiment, the fused diamantane compound is preferably contained in one or more layers selected from the group consisting of a light-emitting layer, a hole-transporting layer, and a hole-injecting layer.

[0075] 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 (e) as an example.

[0076] 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.

[0077] FIG. 1 is a schematic cross-sectional view showing an example of a layered structure of an organic electroluminescent device according to one embodiment of the present invention.

[0078] The organic electroluminescent device 100 includes 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, in this order. 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.

[0079] Alternatively, a single layer having the functions of multiple layers, such as an electron injection / transport layer having both the functions of an electron injection layer and an electron transport layer, may be provided instead of the multiple layers. Furthermore, the single-layer hole transport layer 4 and the single-layer electron transport layer 6 may each be made up of multiple layers. <Layer Containing Fused Diamantane Compound> 1, the organic electroluminescent device 100 contains the fused diamantane compound 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 fused diamantane compound. The fused diamantane compound may be contained in multiple layers of the organic electroluminescent device.

[0080] In the following, an organic electroluminescent device 100 in which the electron transport layer 6 contains a fused diamantane compound will be described. [Substrate 1] The substrate 1 is not particularly limited as long as it is a commonly used substrate, and examples thereof include a glass plate, a quartz plate, a plastic plate, a plastic film, etc. Among these, a glass plate, a quartz plate, and a light-transmitting plastic film are preferable.

[0081] 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.

[0082] In addition, 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 the emitted light. [Anode 2] An anode 2 is provided on the substrate 1 (on the hole injection layer 3 side).

[0083] Examples of the material for the anode include metals, alloys, electrically conductive compounds, and mixtures thereof, each having a large work function (e.g., 4 eV or more). Specific examples of the material for the anode include metals such as Au; CuI, indium tin oxide (ITO), SnO 2 , ZnO and other conductive transparent materials.

[0084] In the case of an organic electroluminescent device in which light is extracted through the anode, the anode is formed of a conductive transparent material that is transparent or substantially transparent to the emitted light. [Hole injection layer 3, hole transport layer 4] Between the anode 2 and a 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.

[0085] The hole injection layer 3 and the hole transport layer 4 have the function of transporting holes injected from the anode to the light-emitting layer. By interposing the hole injection layer 3 and the hole transport layer 4 between the anode 2 and the light-emitting layer 5, a large number of holes are injected into the light-emitting layer 5 with a lower electric field.

[0086] The hole injection layer 3 and the hole transport layer 4 also function as electron barrier layers. That is, the electrons injected from the cathode 8 and transported from the electron injection layer 7 and / or the electron transport layer 6 to the light emitting layer 5 are prevented from leaking to the hole injection layer 3 and / or the hole transport layer 4 by the electron barrier present at the interface between the light emitting layer 5 and the hole injection layer 3 and / or the hole transport layer 4. As a result, the electrons are accumulated at the interface in the light emitting layer 5, which brings about effects such as improved light emitting efficiency, and an organic electroluminescent device with excellent light emitting performance is obtained.

[0087] The material for the hole injection layer 3 and the hole transport layer 4 has at least one of hole injection property, hole transport property, and electron barrier property. The material for the hole injection layer 3 and the hole transport layer 4 may be either an organic compound or an inorganic substance.

[0088] Specific examples of materials for the hole injection layer 3 and the hole transport layer 4 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.

[0089] 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.

[0090] Specific examples of aromatic tertiary amine compounds and styrylamine compounds 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 of such compounds 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-diphenylaminostilbene, N-phenylcarbazole, 4,4'-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (NPD), and 4,4',4''-tris[N-(m-tolyl)-N-phenylamino]triphenylamine (MTDATA).

[0091] Furthermore, examples of the material for the hole injection layer 3 and the hole transport layer 4 include inorganic compounds such as p-type Si and p-type SiC.

[0092] The hole injection layer 3 and the hole transport layer 4 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. [Light-emitting layer 5] Between the hole transport layer 4 and the electron transport layer 6, the light emitting layer 5 is provided.

[0093] Examples of the material of the light-emitting layer 5, that is, the light-emitting material, include phosphorescent materials, fluorescent materials, and thermally activated delayed fluorescent materials. In the light-emitting layer 5, electron-hole pairs are recombined, resulting in light emission.

[0094] The light-emitting layer 5 may consist of a single small molecule or single polymeric 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.

[0095] 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 specifically, 4,4'-bis(2,2-diphenylvinyl)-1,1'-biphenyl (DPVBi), 4,4'-bis(9-ethyl-3-carbazovinylene)-1,1'-biphenyl (BCzVBi), 2-tertiarybutyl-9,10-di(2-naphthyl)anthracene (TBADN), 9,10-di(2-naphthyl)anthracene (ADN), 4,4'-bis(carbazol-9-yl)biphenyl (ADN), 4,4'-bis(carbazol-9-yl)-2,2'-dimethylbiphenyl (CDBP), 2-(9-phenylcarbazol-3-yl)-9-[4-(4-phenylphenylquinazolin-2-yl)carbazole, 9,10-bis(biphenyl)anthracene, and the like can be mentioned.

[0096] Examples of the fluorescent dopant include anthracene, pyrene, tetracene, xanthene, perylene, rubrene, coumarin, rhodamine, quinacridone, dicyanomethylenepyran compound, thiopyran compound, polymethine compound, pyrylium, thiapyrylium compound, fluorene derivative, periflanthene derivative, indenoperylene derivative, bis(azinyl)amine boron compound, bis(azinyl)methane compound, carbostyril compound, boron compound, cyclic amine compound, etc. The fluorescent dopant may be a combination of two or more selected from these.

[0097] Phosphorescent dopants include, for example, complexes of metals such as iridium, platinum, palladium, and osmium.

[0098] Specific examples of fluorescent dopants and phosphorescent dopants include tris(8-hydroxyquinoline)aluminum (Alq3), 4,4'-bis[4-(di-p-tolylamino)styryl]biphenyl (DPAVBi), perylene, bis[2-(4-n-hexylphenyl)quinoline](acetylacetonate)iridium(III), Ir(PPy)3 (tris(2-phenylpyridine)iridium(III)), bis(3,5-difluoro-2-(2-pyridyl)phenyl-(2-carboxypyridyl)iridium(III)) (FIrPic), and the like.

[0099] Moreover, the light-emitting material is not limited to being contained only in the light-emitting layer 5. For example, the light-emitting material may be contained in a layer adjacent to the light-emitting layer 5 (the hole transport layer 4 or the electron transport layer 6). This can further increase the luminous efficiency of the organic electroluminescent device 100.

[0100] The light-emitting layer 5 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 composition or different compositions. [Electron transport layer 6] Between the light-emitting layer 5 and the electron injection layer 7, an electron transport layer 6 is provided.

[0101] The electron transport layer 6 has a function of transporting electrons injected from the cathode 8 to the light-emitting layer. By interposing the electron transport layer 6 between the cathode 8 and the light-emitting layer 5, electrons are injected into the light-emitting layer 5 at a lower electric field.

[0102] As described above, the electron transport layer 6 preferably contains a fused diamantane compound. The electron transport layer 6 may further contain one or more types selected from conventionally known electron transport materials in addition to the fused diamantane compound.

[0103] In addition, when the electron transport layer 6 does not contain a fused diamantane compound but is contained in another layer, one or more types selected from conventionally known electron transport materials can be used as the electron transport material constituting the electron transport layer 6.

[0104] Examples of conventionally known electron transporting materials include alkali metal compounds, alkaline earth metal compounds, transition metal compounds, zinc group element compounds, earth metal compounds, etc. Examples of alkali metal compounds, alkaline earth metal compounds, transition metal compounds, zinc group element compounds, earth metal compounds, etc. include 8-hydroxyquinolinato lithium (Liq), bis(8-hydroxyquinolinato) zinc, bis(8-hydroxyquinolinato) copper, bis(8-hydroxyquinolinato) manganese, tris(8-hydroxyquinolinato) aluminum, tris(2-methyl-8-hydroxyquinolinato) aluminum, tris(8-hydroxyquinolinato) bis(2-methyl-8-quinolinato)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 are examples of chelate-type aryloxides.

[0105] The electron transport layer 6 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 composition or different compositions.

[0106] In the organic electroluminescent device 100, an electron injection layer 7 may be provided for the purpose of improving the electron injection property and improving the device characteristics (for example, luminous efficiency, low-voltage driving, or high durability). [Electron injection layer 7] Between the electron transport layer 6 and a cathode 8 described below, an electron injection layer 7 is provided.

[0107] The electron injection layer 7 has a function of transferring electrons injected from the cathode to the light-emitting layer 5. By interposing the electron injection layer between the cathode 8 and the light-emitting layer 5, electrons are injected into the light-emitting layer 5 at a lower electric field.

[0108] Examples of materials for the electron injection layer 7 include organic compounds such as fluorenone, anthraquinodimethane, diphenoquinone, thiopyran dioxide, oxazole, oxadiazole, triazole, imidazole, perylene tetracarboxylic acid, fluorenylidenemethane, anthraquinodimethane, and anthrone.

[0109] The material of the electron injection layer 7 is SiO 2 Also included are inorganic compounds such as various oxides, fluorides, nitrides, and oxynitrides, such as AlO, SiN, SiON, AlON, GeO, LiO, LiON, TiO, TiON, TaO, TaON, TaN, LiF, C, and Yb. [Cathode 8] A cathode 8 is provided on the electron injection layer 7 .

[0110] In the case of an organic electroluminescence element having a configuration in which only light emitted through the anode 8 is extracted, the cathode 8 can be formed from any conductive material.

[0111] Examples of materials for the cathode 8 include metals with a small work function (hereinafter also referred to as electron injecting metals), alloys, electrically conductive compounds, and mixtures thereof. Here, the metals with a small work function are, for example, metals with a work function of 4 eV or less.

[0112] Specific examples of the material of the cathode 8 include sodium, sodium-potassium alloy, magnesium, lithium, magnesium / copper mixture, magnesium / silver mixture, magnesium / aluminum mixture, magnesium / indium mixture, and aluminum / aluminum oxide (Al 2 O 3 ) mixtures, indium, lithium / aluminum mixtures, rare earth metals, etc.

[0113] Among these, from the viewpoints of electron injection property and durability against oxidation, etc., mixtures of an electron injection metal and a second metal which is a metal having a larger and more stable work function than the electron injection metal, such as magnesium / silver mixtures, magnesium / aluminum mixtures, magnesium / indium mixtures, and aluminum / aluminum oxide (Al 2 O 3 ) mixture, lithium / aluminum mixture, etc. are preferred. [Hole blocking layer] As described above, the organic electroluminescent device 100 may further include a hole blocking layer.

[0114] Although not shown in FIG. 1, for example, a hole blocking layer can be provided between the light emitting layer 5 and the electron transporting layer 6 .

[0115] The hole blocking layer has a role of improving the luminous efficiency by, for example, suppressing leakage of holes from the light emitting layer and increasing the probability of recombination of electrons and holes.

[0116] Specific examples of the material for the hole blocking layer include triazine derivatives, pyrimidine derivatives, fluoranthene derivatives, polycyclic aromatic hydrocarbon compounds, carbazole derivatives, fluorene derivatives, and spirofluorene derivatives. [How each layer is formed] Each layer except for the electrodes (anode, 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 of each layer may be used alone or, if necessary, together with a material such as a binder resin or a solvent.

[0117] There are no particular limitations on the film thickness of each layer thus formed, and it can be appropriately selected depending on the situation, but it is usually in the range of 5 nm to 5 μm.

[0118] The anode 1 and the cathode 8 can be formed by forming a thin film of an electrode material by a method such as vapor deposition or sputtering. 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 or the like after forming a thin film by vapor deposition or sputtering.

[0119] The film thickness of the anode 1 and the cathode 8 is preferably 1 μm or less, and more preferably 10 nm to 200 nm.

[0120] The layer containing the fused diamantane compound may be used in combination with the above-mentioned conventionally known electron transporting material. Thus, for example, the fused diamantane compound and the conventionally known electron transporting material may be co-deposited, or a layer of the conventionally known electron transporting material may be laminated on the layer of the fused diamantane compound.

[0121] The organic electroluminescent device may be used as a type of lamp for illumination or as an exposure light source, or as a projection device that projects an image onto a screen or the like, or as a display device (display) that directly displays still images or moving images.

[0122] When an organic electroluminescent device is 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. In addition, a full-color display device can be produced by using two or more kinds of organic electroluminescent devices having different luminescent colors. EXAMPLES

[0123] The present disclosure will be described in more detail below based on examples, but the present disclosure should not be construed as being limited to these examples.

[0124] 1H-NMR spectra were measured using Gemini200 (Varian) or Bruker ASCEND 400 (400 MHz; BRUKER).

[0125] The light-emitting characteristics of the organic electroluminescent device were evaluated by applying a direct current to the fabricated device at room temperature using a luminance meter (product name: BM-9, manufactured by Topcon Technohouse Corporation). (Synthesis Example 1)

[0126] [ka]

[0127] Under an argon atmosphere, 2-bromo-4'-chloro-1,1'-biphenyl (2.8g, 10mmol) was suspended in tetrahydrofuran (52mL), and 1.6M n-butyllithium solution (7.2mL, 11mmol) was added dropwise and stirred at -78℃ for 1 hour. A solution of 3-diamantanone (2.1g, 10mmol) dissolved in tetrahydrofuran (52mL) was added dropwise and stirred at room temperature for 10 hours. The obtained organic layer was concentrated, suspended in trifluoroacetic acid (3.9mL) and 1,2-dichlorobenzene (51mL), and stirred at 120℃ for 3 hours. After cooling to 0℃, an aqueous potassium carbonate solution and toluene were added, and the organic layer was separated and extracted. The obtained organic layer was concentrated and purified by column chromatography to obtain the desired 2-chloro-spiro(9H-fluorene-9,3'-diamantane) (yield 1.10g, 29%). 1H-NMR (400MHz, CDCl 3 ):8.06-8.09(m,2H),7.75(dd,J=1.6Hz,7.6Hz,1H),7.70(d,J=8.0Hz,1H),7.34-7.39(m,2H),7.25-7.29 (m,1H),2.84-2.93(m,3H),2.81(s,1H),2.11(s,2H),1.80-1.89(m,6H),1.58-1.74(m,5H),1.42(s,1H). (Synthesis Example 2) TIFF2025079367000015.tif31118

[0128] Under an argon atmosphere, 3-chloro-spiro(9H-fluorene-9,3'-diamantane) (1.05g, 2.82mmol), bis(neopentylglycolate)diboron (0.700g, 3.10mmol), palladium acetate (12.6mg, 0.056mmol), 2-dicyclohexylphosphino-2',4',6'-triisopropylbiphenyl (53.7mg, 0.11mol), and potassium acetate (0.829g, 8.45mmol) were suspended in tetrahydrofuran (28mL) and stirred at 70℃ for 3 hours. After cooling to room temperature, the precipitate was removed by filtration. The filtrate was concentrated under reduced pressure and dried to obtain a crude product. Methanol was added, stirred and suspended, and the solid was filtered off. The obtained solid was dried under reduced pressure to obtain a gray powder of 2-(5,5-dimethyl-1,3,2-dioxaborinane-2-yl)-spiro(9H-fluorene-9,3′-diamantane) (yield: 1.1 g, 87%). 1H-NMR(CDCl3)δ(ppm):8.50(s,1H),8.10(d,J=9.2Hz,1H),7.78-7.84(m,3H),7. 37(dd,J=16.0Hz,16.0Hz,1H),7.24-7.29(m,1H),3.80(s,4H),3.06(dd,J=3.2Hz ,14.8Hz,1H),2.91-3.00(m,3H),2.18(s,1H),2.10(s,1H),1.79-1.90(m,6H),1. 70(dd,J=1.6Hz,13.6Hz,2H),1.61(s,2H),1.58(s,1H),1.42(s,1H),1.05(s,6H). (Synthesis Example 1)

[0129] [ka]

[0130] Under an argon atmosphere, 2-chloro-4,6-diphenyl-1,3,5-triazine (0.570 g, 2.13 mmol), 2-(5,5-dimethyl-1,3,2-dioxaborinane-2-yl)-spiro(9H-fluorene-9,3'-diamantane) (1.09 g, 2.34 mmol), and tetrakis(triphenylphosphine)palladium (73.8 mg, 0.064 mmol) were dissolved in tetrahydrofuran (21 mL). 2M potassium phosphate aqueous solution (3.19 mL, 6.39 mmol) was added to the solution and stirred at 70°C for 8 hours. After cooling to room temperature, the precipitate was removed by filtration. After cooling to room temperature, methanol was added and the precipitated solid was filtered. The filtered product was suspended in toluene (100 mL), heated to 100°C, activated carbon was added, and the mixture was stirred, followed by celite filtration. The filtrate was concentrated and purified by recrystallization from toluene to obtain compound (1-5) as a white solid (0.91 g, 75% yield). The glass transition temperature was 132°C. 1H-NMR(CDCl3)δ(ppm):9.63(s,1H),8.78-8.81(m,6H),8.17(d,8.0Hz,1H),7.97(d,7.6Hz,1H),7 .93(brdd,J=1.2Hz,7.6Hz,1H),7.58-7.68(m,7H),7.44(dd,J=7.6Hz,7.6Hz,1H),7.32-7.37(m,1 H),3.28(d,J=13.6Hz,1H),3.17(s,1H),3.03(d,J=13.6Hz,1H),2.96(s,1H),2.30(s,1H),2.17(s ,1H),1.95(s,1H),1.80-1.91(m,5H),1.76(s,1H),1.66(dd,J=13.6Hz,13.6Hz,2H),1.52(s,1H). (Synthesis Example 3)

[0131] [ka]

[0132] Under an argon atmosphere, 2-bromo-6-chloro-1,1'-biphenyl (3.6g, 14mmol) was suspended in tetrahydrofuran (62mL), and 1.6M n-butyllithium solution (10.2mL, 16mmol) was added dropwise and stirred at -78℃ for 1 hour. A solution of 3-diamantanone (2.5g, 12mmol) dissolved in tetrahydrofuran (62mL) was added dropwise and stirred at room temperature for 10 hours. The obtained organic layer was concentrated, suspended in trifluoroacetic acid (4.2mL) and 1,2-dichlorobenzene (55mL), and stirred at 120℃ for 3 hours. After cooling to 0℃, an aqueous potassium carbonate solution and toluene were added, and the organic layer was separated and extracted. The obtained organic layer was concentrated and purified by column chromatography to obtain the desired 4-chloro-spiro(9H-fluorene-9,3'-diamantane) (yield 3.22g, 79%). 1H-NMR(CDCl3)δ(ppm):8.73(dd,J=1.2Hz,7.6Hz,1H),8.16(d,J=8.0Hz,1H),8.08(d,J=7.6Hz,1H),7.29-7.43(m,3 H),7.17(t,J=8.0Hz,8.0Hz,1H),2.88-3.06(m,3H),2.11(s,2H),1.77-1.89(m,6H),1.57-1.73(m,6H),1.39(s,1H) . (Synthesis Example 2)

[0133] [ka]

[0134] Under an argon atmosphere, 2,4-diphenyl-6-[3'-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)[1,1'-biphenyl]-3-yl]-1,3,5-triazine (1.37g, 2.68mmol), 4-chloro-spiro(9H-fluorene-9,3'-diamantane) (1.10g, 2.95mmol), palladium acetate (18mg, 0.080mmol) and 2-dicyclohexylphosphino-2',4',6'-triisopropylbiphenyl (0.66g, 0.16mmol) were dissolved in THF (27mL). 2M potassium phosphate aqueous solution (4.0mL, 8.0mmol) was added to this and stirred at 70℃ for 4 hours. After cooling to room temperature, the precipitate was removed by filtration. After cooling to room temperature, methanol was added and the precipitated solid was filtered. The filtered material was suspended in toluene (300 mL) and heated to 100°C, activated carbon was added, stirred, and then filtered through Celite. The filtrate was concentrated and purified by recrystallization with toluene to obtain a white solid of compound (1-35) (1.0 g, yield 52%). The glass transition temperature was 158°C. 1H-NMR(CDCl3)δ(ppm):9.04(s,1H),8.75-8.78(m,5H),8.22(d,J=8.8Hz,1H),8.15(d,J=8.0Hz,1H),7.81-7.88(m,3H),7. 48-7.68(m,10H),7.32(dd,J=8.0Hz,15.6Hz,1H),7.14-7.18(m,1H),2.98-3.12(m,4H),2.14(brs,1H),1.56-1.91(m,11H). The structural formulas and abbreviations of the compounds used in the preparation and performance evaluation of the organic electroluminescent device are shown below.

[0135] [ka]

[0136] Element Example 1 (see Figure 2) (Preparation of substrate 101 and anode 102) A glass substrate with an indium-tin oxide (ITO) transparent electrode, on which a 2 mm wide ITO film (thickness 110 nm) was patterned in stripes, was prepared as a substrate with an anode on its surface. The substrate was then washed with isopropyl alcohol and then subjected to surface treatment with ozone ultraviolet cleaning. (Preparation for vacuum deposition) After cleaning and surface treatment, each layer was deposited by vacuum deposition on the substrate by vacuum deposition, forming a laminate of each layer.

[0137] First, the glass substrate was placed in a vacuum deposition chamber and 1.0×10 -4 The pressure was reduced to 10 Pa. Then, each layer was formed according to the film formation conditions in the following order. (Fabrication of Hole Injection Layer 103) The sublimated and purified HTL and NDP-9 were deposited at a rate of 0.15 nm / sec to form a 10 nm thick film, forming a hole injection layer 103 . (Preparation of the first hole transport layer 1051) The sublimation-purified HTL was formed into a film of 85 nm at a rate of 0.15 nm / sec to form a first hole transport layer 1051 . (Preparation of second hole transport layer 1052) The sublimation-purified EBL-1 was formed into a film having a thickness of 5 nm at a rate of 0.15 nm / sec to prepare a second hole transport layer 1052 . (Fabrication of the Light-Emitting Layer 106) Sublimation-purified BH-1 and BD-1 were mixed in a ratio of 95:5 (mass ratio) to form a film of 20 nm, thereby producing the light-emitting layer 106. The film formation rate was 0.18 nm / sec. (Preparation of First Electron Transport Layer 1071) The sublimation-purified HBL-1 was formed into a film of 6 nm at a rate of 0.05 nm / sec to form a first electron transport layer 1071 . (Preparation of second electron transport layer 1072) The compound and Liq were mixed in a ratio of 50:50 (mass ratio) to form a film of 25 nm, thereby forming a second electron transport layer 1072. The film formation rate was 0.15 nm / sec. (Preparation of cathode 108) Finally, a metal mask was placed so as to be perpendicular to the ITO stripes on the substrate, and the cathode 108 was formed. The cathode was a three-layer structure in which ytterbium, silver / magnesium (mass ratio 9 / 1), and silver were formed in that order to thicknesses of 2 nm, 12 nm, and 90 nm, respectively. The deposition rate of ytterbium was 0.02 nm / sec, that of silver / magnesium was 0.5 nm / sec, and that of silver was 0.2 nm / sec.

[0138] As a result, the light-emitting area of ​​4 mm2 shown in Figure 2 2 An organic electroluminescence device 100 was produced. The film thickness of each layer was measured using a stylus film thickness measuring instrument (DEKTAK, manufactured by Bruker).

[0139] Furthermore, this element was sealed in a nitrogen atmosphere glove box with oxygen and moisture concentrations of 1 ppm or less by sealing a glass sealing cap and the film-formed substrate (element) with bisphenol F type epoxy resin (manufactured by Nagase ChemteX Corporation).

[0140] A direct current was applied to the organic electroluminescence device fabricated as described above, and a current density of 10 mA / cm 2 The driving voltage (V) was measured when current was passed through the device. The current efficiency is a relative value with the result in Comparative Example Element-1 described later taken as the reference value (100). The measurement results are shown in Table 1. Element comparison example-1 An organic electroluminescence device was produced and evaluated in the same manner as in Element Example 1, except that ETL-1 was used instead of compound (1-5) in Element Example 1. The measurement results obtained are shown in Table 1.

[0141] [Table 1]

[0142] Element Example 2 (see Figure 2) (Preparation of substrate 101 and anode 102) A glass substrate with an indium-tin oxide (ITO) transparent electrode, on which a 2 mm wide ITO film (thickness: 110 nm) was patterned in stripes, was prepared as a substrate with an anode on its surface. The substrate was then washed with isopropyl alcohol and then subjected to surface treatment with ozone ultraviolet cleaning. (Preparation for vacuum deposition) After cleaning and surface treatment, each layer was deposited by vacuum deposition on the substrate by vacuum deposition, so that each layer was laminated.

[0143] First, the glass substrate was placed in a vacuum deposition chamber and 1.0×10 -4 The pressure was reduced to 10 Pa. Then, each layer was formed according to the film formation conditions in the following order. (Fabrication of Hole Injection Layer 103) The sublimated and purified HTL and NDP-9 were deposited at a rate of 0.15 nm / sec to form a 10 nm thick film, forming a hole injection layer 103 . (Preparation of the first hole transport layer 1051) The sublimation-purified HTL was formed into a film of 85 nm at a rate of 0.15 nm / sec to form a first hole transport layer 1051 . (Preparation of second hole transport layer 1052) The sublimation-purified EBL-1 was formed into a film having a thickness of 5 nm at a rate of 0.15 nm / sec to prepare a second hole transport layer 1052 . (Fabrication of the Light-Emitting Layer 106) Sublimation-purified BH-1 and BD-1 were mixed in a ratio of 95:5 (mass ratio) to form a film of 20 nm, thereby producing the light-emitting layer 106. The film formation rate was 0.18 nm / sec. (Preparation of First Electron Transport Layer 1071) The sublimated and purified compound (1-35) was formed into a film of 6 nm at a rate of 0.05 nm / sec to form a first electron transport layer 1071 . (Preparation of second electron transport layer 1072) A film of 25 nm was formed by mixing ETL-1 and Liq in a ratio of 50:50 (mass ratio) to prepare a second electron transport layer 1072. The film formation rate was 0.15 nm / sec. (Preparation of cathode 108) Finally, a metal mask was placed so as to be perpendicular to the ITO stripes on the substrate, and the cathode 108 was formed. The cathode was a three-layer structure in which ytterbium, silver / magnesium (mass ratio 9 / 1), and silver were formed in that order to thicknesses of 2 nm, 12 nm, and 90 nm, respectively. The deposition rate of ytterbium was 0.02 nm / sec, that of silver / magnesium was 0.5 nm / sec, and that of silver was 0.2 nm / sec.

[0144] As a result, the light-emitting area of ​​4 mm2 shown in Figure 2 2 An organic electroluminescence device 100 was produced. The film thickness of each layer was measured using a stylus film thickness measuring instrument (DEKTAK, manufactured by Bruker).

[0145] Furthermore, this element was sealed in a nitrogen atmosphere glove box with oxygen and moisture concentrations of 1 ppm or less by sealing a glass sealing cap and the film-formed substrate (element) with bisphenol F type epoxy resin (manufactured by Nagase ChemteX Corporation).

[0146] A direct current was applied to the organic electroluminescent device fabricated as described above, and the driving voltage (V) was measured when a current density of 10 mA / cm2 was applied. The current efficiency is a relative value with the result in Comparative Example 1 of the device described below taken as the reference value (100). The measurement results are shown in Table 2. Element comparison example-2 An organic electroluminescence device was produced and evaluated in the same manner as in Element Example 1, except that HBL-1 was used instead of compound (1-35) in Element Example 1. The measurement results obtained are shown in Table 1.

[0147] [Table 2]

[0148] The present disclosure includes the following embodiments.

[0149] [1] A fused ring diamantane compound having groups represented by the following formula (1) and formula (2):

[0150] [ka]

[0151] In formula (1), a carbon atom in the diamantane ring may be substituted with an aryl group having 6 to 12 carbon atoms. In formula (1), * represents a bond. a represents an integer of 1 to 6. Ring A and ring B in formula (1) are each independently (i) an aromatic hydrocarbon group having 6 to 60 carbon atoms which may be substituted, or (ii) an optionally substituted heteroaromatic group having 3 to 60 carbon atoms, (Indicates

[0152] [ka]

[0153] In formula (2), * represents a bond, and b represents an integer of 1 to 6. In formula (2), each Ar is independently (I) an aromatic hydrocarbon group having 6 to 60 carbon atoms which may be substituted, (II) an optionally substituted heteroaromatic group having 3 to 60 carbon atoms, (III) an optionally substituted nitrogen atom, or (IV) represents a group formed by combining the above groups (I) to (III). [2] The fused diamantane compound according to [1], wherein the fused diamantane compound is represented by the following formula (3) or (4):

[0154] [ka]

[0155] (The carbon atom in the diamantane ring in formula (3) may be substituted with an aryl group having 6 to 12 carbon atoms. In formula (3), ring A and ring B each independently represent (i) an aromatic hydrocarbon group having 6 to 60 carbon atoms, or (ii) a heteroaromatic group having 3 to 60 carbon atoms, Carbon atoms other than the carbon atom bonded to the -Ar group may have a substituent. In formula (3), each Ar is independently (I) an aromatic hydrocarbon group having 6 to 60 carbon atoms which may be substituted, (II) an optionally substituted heteroaromatic group having 3 to 60 carbon atoms, (III) an optionally substituted nitrogen atom, or (IV) a group obtained by combining the groups (I) to (III) above, Shows. m represents an integer of 1 to 6.

[0156] [ka]

[0157] (The carbon atom in the diamantane ring in formula (4) may be substituted with an aryl group having 6 to 12 carbon atoms. In formula (4), ring A and ring B each independently represent (i) an aromatic hydrocarbon group having 6 to 60 carbon atoms, or (ii) a heteroaromatic group having 3 to 60 carbon atoms, Carbon atoms other than the carbon atom bonded to the -Ar group may have a substituent. Ar in formula (4) is (I) an aromatic hydrocarbon group having 6 to 60 carbon atoms which may be substituted, (II) an optionally substituted heteroaromatic group having 3 to 60 carbon atoms, (III) an optionally substituted nitrogen atom, or (IV) a group obtained by combining the groups (I) to (III) above, Shows. n represents an integer of 2 to 3. [3] The fused diamantane compound according to [1] or [2], wherein the fused diamantane compound is represented by any one of the following formulas (5-1) to (5-3):

[0158] [ka]

[0159] [ka]

[0160] [ka]

[0161] (The carbon atoms in the diamantane ring in the formulas (5-1) to (5-3) may be substituted with an aryl group having 6 to 12 carbon atoms. Ring A and ring B in formulae (5-1) to (5-3) are each independently (i) an aromatic hydrocarbon group having 6 to 60 carbon atoms, or (ii) a heteroaromatic group having 3 to 60 carbon atoms, Carbon atoms other than the carbon atom bonded to the -Ar group may have a substituent. In the formulas (5-1) to (5-3), Ar is each independently (I) an aromatic hydrocarbon group having 6 to 60 carbon atoms which may be substituted, (II) an optionally substituted heteroaromatic group having 3 to 60 carbon atoms, (III) an optionally substituted nitrogen atom, or (IV) a group obtained by combining the groups (I) to (III) above, (Indicates [4] The fused diamantane compound according to any one of [1] to [3], wherein the heteroaromatic group (ii) contains any one of a nitrogen atom, an oxygen atom, and a sulfur atom.

[0162] [5] The fused diamantane compound according to any one of [1] to [4], wherein the heteroaromatic group (II) contains any one of a nitrogen atom, an oxygen atom, and a sulfur atom.

[0163] [6] Ar in formula (2) is The optionally substituted nitrogen atom of (III), and The above (I) optionally substituted aromatic hydrocarbon group having 6 to 60 carbon atoms, or the above (II) optionally substituted heteroaromatic group having 3 to 60 carbon atoms, The fused diamantane compound according to any one of [1] to [5],

[0164] [7] The substituent in the optionally substituted aromatic hydrocarbon group of the above (i) or the optionally substituted heteroaromatic group of the above (ii) is a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a formyl group, a cyano group, a nitro group, an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 1 to 20 carbon atoms, a cycloalkyl group having 1 to 20 carbon atoms, a bicycloalkyl group having 1 to 20 carbon atoms, a tricycloalkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, P(═O)(Ar 1 ) 2 , C(=O)Ar 1 , B(Ar 1 ) 2 , B(OAr 1 ) 2 , O.S.O. 2 Ar 1 , S(=O)Ar 1 , Si(Ar 1 ) 3 , P(=S)(Ar 1 ) 2 , and C(=C(CN) 2 )Ar 1 2 The fused diamantane compound according to any one of [1] to [6], wherein R is a group selected from the group consisting of (The above Ar 1 is a group selected from the group consisting of an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 60 carbon atoms, and a heteroaromatic group having 3 to 60 carbon atoms. [8] The fused diamantane compound according to any one of [1] to [7], wherein the heteroaromatic group (ii) contains a nitrogen atom.

[0165] [9] The fused diamantane compound according to any one of [1] to [8], wherein the heteroaromatic group (II) contains a nitrogen atom.

[0166]

[10] The fused ring diamantane compound according to any one of [1] to [9], wherein Ar in the above formula (2) has a fused ring aromatic hydrocarbon group having 14 to 60 carbon atoms.

[0167]

[11] A material for an organic electroluminescent device, comprising the fused diamantane compound according to any one of [1] to

[10] .

[0168]

[12] The material for organic electroluminescent devices according to

[11] , wherein the material for organic electroluminescent devices is an electron transport material for organic electroluminescent devices or a hole transport material for organic electroluminescent devices.

[0169]

[13] An organic electroluminescence device comprising the fused diamantane compound according to any one of [1] to

[10] . [Explanation of symbols]

[0170] 100 Organic electroluminescent device 1 Board 2 Anode 3. Hole injection layer 4. Hole transport layer 41 First hole transport layer 42 Second hole transport layer 5. Light-emitting layer 6 Electron transport layer 7 Electron injection layer 8 cathode 101 Substrate 102 Anode 103 Hole injection layer 1051 First hole transport layer 1052 Second hole transport layer 106 Light-emitting layer 1071 First electron transport layer 1072 Second electron transport layer 108 Cathode

Claims

1. A fused ring diamantane compound having groups represented by the following formula (1) and formula (2): 【Chemistry 1】 (In formula (1), a carbon atom in the diamantane ring may be substituted with an aryl group having 6 to 12 carbon atoms. In formula (1), * represents a bond. a represents an integer of 1 to 6. In formula (1), ring A and ring B each independently represent (i) an aromatic hydrocarbon group having 6 to 60 carbon atoms which may be substituted, or (ii) an optionally substituted heteroaromatic group having 3 to 60 carbon atoms; Indicates.) 【Chemistry 2】 In formula (2), * represents a bond, and b represents an integer of 1 to 6. In formula (2), each Ar is independently (I) an optionally substituted aromatic hydrocarbon group having 6 to 60 carbon atoms, (II) an optionally substituted heteroaromatic group having 3 to 60 carbon atoms; (III) an optionally substituted nitrogen atom, or (IV) a group obtained by combining the above groups (I) to (III), Indicates.)

2. The fused diamantane compound according to claim 1 , wherein the fused diamantane compound is represented by the following formula (3) or (4): 【Chemistry 3】 (The carbon atom in the diamantane ring in formula (3) may be substituted with an aryl group having 6 to 12 carbon atoms. In formula (3), ring A and ring B each independently represent (i) an aromatic hydrocarbon group having 6 to 60 carbon atoms, or (ii) a heteroaromatic group having 3 to 60 carbon atoms; Carbon atoms other than the carbon atom bonded to the --Ar group may have a substituent. In formula (3), each Ar is independently (I) an optionally substituted aromatic hydrocarbon group having 6 to 60 carbon atoms, (II) an optionally substituted heteroaromatic group having 3 to 60 carbon atoms; (III) an optionally substituted nitrogen atom, or (IV) a group obtained by combining the above groups (I) to (III), Shows. m represents an integer of 1 to 6. 【Chemistry 4】 (The carbon atom in the diamantane ring in formula (4) may be substituted with an aryl group having 6 to 12 carbon atoms. In formula (4), ring A and ring B each independently represent (i) an aromatic hydrocarbon group having 6 to 60 carbon atoms, or (ii) a heteroaromatic group having 3 to 60 carbon atoms, Carbon atoms other than the carbon atom bonded to the --Ar group may have a substituent. In formula (4), Ar is (I) an optionally substituted aromatic hydrocarbon group having 6 to 60 carbon atoms, (II) an optionally substituted heteroaromatic group having 3 to 60 carbon atoms; (III) an optionally substituted nitrogen atom, or (IV) a group obtained by combining the above groups (I) to (III), Shows. n represents an integer of 2 to 3.

3. The fused diamantane compound according to claim 2, which is represented by any one of the following formulas (5-1) to (5-3): 【Chemistry 5】 【Chemistry 6】 【Chemistry 7】 (The carbon atoms in the diamantane ring in formulas (5-1) to (5-3) may be substituted with an aryl group having 6 to 12 carbon atoms. Ring A and ring B in formulas (5-1) to (5-3) are each independently (i) an aromatic hydrocarbon group having 6 to 60 carbon atoms, or (ii) a heteroaromatic group having 3 to 60 carbon atoms, Carbon atoms other than the carbon atom bonded to the --Ar group may have a substituent. In formulas (5-1) to (5-3), Ar is each independently (I) an optionally substituted aromatic hydrocarbon group having 6 to 60 carbon atoms, (II) an optionally substituted heteroaromatic group having 3 to 60 carbon atoms; (III) an optionally substituted nitrogen atom, or (IV) a group obtained by combining the above groups (I) to (III), Indicates.)

4. The fused diamantane compound according to claim 1, wherein the heteroaromatic group (ii) contains any one of a nitrogen atom, an oxygen atom, and a sulfur atom.

5. 2. The fused diamantane compound according to claim 1, wherein the heteroaromatic group (II) contains any one of a nitrogen atom, an oxygen atom, and a sulfur atom.

6. In the formula (2), Ar is The optionally substituted nitrogen atom of (III), and The above (I) optionally substituted aromatic hydrocarbon group having 6 to 60 carbon atoms, or the above (II) optionally substituted heteroaromatic group having 3 to 60 carbon atoms, The fused diamantane compound according to claim 1,

7. The substituent in the optionally substituted aromatic hydrocarbon group of (i) above or the optionally substituted heteroaromatic group of (ii) above is a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a formyl group, a cyano group, a nitro group, an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 1 to 20 carbon atoms, a cycloalkyl group having 1 to 20 carbon atoms, a bicycloalkyl group having 1 to 20 carbon atoms, a tricycloalkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, P(═O)(Ar １ ) ２ , C(=O)Ar １ , B(Ar １ ) ２ , B(OAr １ ) ２ , OSO ２ Ar １ , S(=O)Ar １ , Si(Ar １ ) ３ , P(=S)(Ar １ ) ２ , and C(=C(CN) ２ ) Ar １ ２ The fused ring diamantane compound according to claim 1, wherein the ring is a group selected from the group consisting of: (The above Ar １ is a group selected from the group consisting of an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 60 carbon atoms, and a heteroaromatic group having 3 to 60 carbon atoms.

8. The fused diamantane compound according to claim 1 , wherein the heteroaromatic group (ii) contains a nitrogen atom.

9. 2. The fused diamantane compound of claim 1, wherein the heteroaromatic group of (II) contains a nitrogen atom.

10. 2. The fused ring diamantane compound according to claim 1, wherein Ar in the above formula (2) has a fused ring aromatic hydrocarbon group having 14 to 60 carbon atoms.

11. A material for an organic electroluminescent device, comprising the fused diamantane compound according to any one of claims 1 to 10.

12. The material for organic electroluminescent devices according to claim 11 , wherein the material for organic electroluminescent devices is an electron transport material for organic electroluminescent devices or a hole transport material for organic electroluminescent devices.

13. An organic electroluminescence device comprising the fused diamantane compound according to any one of claims 1 to 10.

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