Compound, organic el element, display device, and lighting device

Abstract

The present invention addresses the problem of providing an organic EL element having excellent luminous efficiency and service life.　This compound is represented by general formula (1) or general formula (2).

Description

Compound, organic EL element, display device and lighting device

[0001] The present invention relates to a compound, and an organic EL device, a display device, and a lighting device using the compound.

[0002] In recent years, organic EL elements have been steadily put to practical use, including their use in television and smartphone displays. However, existing organic EL elements still have many technical challenges. One of the biggest challenges is achieving both highly efficient light emission and a long lifespan for organic EL elements.

[0003] As compounds that solve these problems, phenanthroline derivatives having a pyridylamine structure (see, for example, Patent Document 1), phenanthroline derivatives having a carboline structure (see, for example, Patent Documents 2 to 5), and phenanthrolines having pyridylamine structures linked via dimethylmethylene groups (see, for example, Patent Document 6) have been developed to date.

[0004] Chinese Patent Application Publication No. 112724073 Korean Patent Application Publication No. 2015-0113754 Chinese Patent Application Publication No. 106986870 International Patent Application Publication No. 2020-067594 Korean Patent Application Publication No. 2022-0022248 Korean Patent No. 101926768

[0005] However, in recent years, the luminous efficiency and durability required of organic EL elements have been increasing, and there is a demand for a technology that can achieve both higher luminous efficiency and a longer lifespan.

[0006] In view of the above problems of the prior art, an object of the present invention is to provide an organic EL element having excellent luminous efficiency and durable life.

[0007] In order to solve the above problems, the present invention has the following configuration: [1] A compound represented by the following general formula (1) or (2):

[0008]

[0009] (In the general formula (1), Ar １０１ ~Ar １０２are each independently a substituted or unsubstituted aryl group or a substituted or unsubstituted heteroaryl group, Ar １０３ is a substituted or unsubstituted arylene group or a substituted or unsubstituted heteroarylene group, Ar １０１ ~Ar １０３ At least one of L is a group containing a nitrogen atom. １０１ R is a single bond, a substituted or unsubstituted phenylene group, a substituted or unsubstituted naphthylene group, a substituted or unsubstituted pyridylene group, a substituted or unsubstituted pyridazylene group, a substituted or unsubstituted pyrazylene group, a substituted or unsubstituted pyrimidylene group, or a substituted or unsubstituted triazylene group. １０１ ~R １０７ are each independently selected from the group consisting of a hydrogen atom, an alkyl group, an alkoxy group, a phosphoryl group, a halogen atom, a cyano group, a substituted or unsubstituted aryl group, and a substituted or unsubstituted heteroaryl group.

[0010]

[0011] (In the general formula (2), Ar ２０１ ~Ar ２０２ are each independently a substituted or unsubstituted aryl group or an unsubstituted heteroaryl group having 10 or less carbon atoms, and Ar ２０３ is a substituted or unsubstituted arylene group or an unsubstituted heteroarylene group having 10 or less carbon atoms, Ar ２０１ ~Ar ２０３ At least one of Ar is a group containing a nitrogen atom in the ring. ２０１ and Ar ２０２ , Ar ２０２ and Ar ２０３ , Ar ２０１ and Ar ２０３ At least one pair of L is linked to each other to form a ring structure. ２０１ R is a single bond, a substituted or unsubstituted phenylene group, a substituted or unsubstituted naphthylene group, a substituted or unsubstituted pyridylene group, a substituted or unsubstituted pyridazylene group, a substituted or unsubstituted pyrazylene group, a substituted or unsubstituted pyrimidylene group, or a substituted or unsubstituted triazylene group.２０１ is an unsubstituted aryl group or an unsubstituted heteroaryl group, and R ２０２ ~R ２０７ are each independently selected from the group consisting of a hydrogen atom, an alkyl group, an alkoxy group, a phosphoryl group, a halogen atom, a cyano group, a substituted or unsubstituted aryl group, and a substituted or unsubstituted heteroaryl group. １０１ ~Ar １０２ and Ar in general formula (2) ２０１ ~Ar ２０２ are each independently selected from the group consisting of a substituted or unsubstituted phenyl group, a substituted or unsubstituted naphthyl group, a substituted or unsubstituted anthryl group, a substituted or unsubstituted phenanthrenyl group, a substituted or unsubstituted pyrenyl group, a substituted or unsubstituted pyridyl group, a substituted or unsubstituted pyrimidyl group, and a substituted or unsubstituted quinoxalinyl group, and Ar １０３ and Ar in general formula (2) ２０３ is selected from the group consisting of a substituted or unsubstituted phenylene group, a substituted or unsubstituted naphthylene group, a substituted or unsubstituted anthrylene group, a substituted or unsubstituted phenanthrenylene group, a substituted or unsubstituted pyrenylene group, a substituted or unsubstituted pyridylene group, a substituted or unsubstituted pyrimidylene group, and a substituted or unsubstituted quinoxalinylene group. １０１ and L in general formula (2) ２０１ is a single bond, an unsubstituted phenylene group, an unsubstituted naphthylene group, an unsubstituted pyridylene group, an unsubstituted pyridazylene group, an unsubstituted pyrazylene group, an unsubstituted pyrimidylene group, or an unsubstituted triazylene group. １０２ ~R １０７ and R in general formula (2) ２０２ ~R ２０７ [5] The compound according to any one of the above [1] to [3], wherein Ar in the general formula (1) is a hydrogen atom. １０１ ~Ar １０２and Ar in general formula (2). ２０１ ~Ar ２０２ The compound according to any one of [1] to [4] above, wherein at least one of the groups is independently an aryl group substituted with a group containing a nitrogen atom. [6] An organic EL device that emits light in response to electrical energy, having at least an electron transport layer and an emitting layer between an anode and a cathode, wherein the electron transport layer contains the compound according to any one of [1] to [5] above. [7] The organic EL device according to [6] above, wherein the electron transport layer further contains an alkali metal, a rare earth metal, or a complex of an alkali metal with an organic substance. [8] An organic EL device that emits light in response to electrical energy, having at least a charge generation layer and an emitting layer between an anode and a cathode, wherein the charge generation layer contains the compound according to any one of [1] to [5] above. [9] The organic EL device according to [8] above, wherein the charge generation layer further contains a phenanthroline derivative.

[10] The organic EL device according to [8] or [9] above, wherein the charge generation layer further contains an alkali metal or a rare earth metal.

[11] The organic EL device according to

[10] above, wherein the charge generation layer further contains an alkali metal, and the alkali metal is Li.

[12] The organic EL device according to

[10] or

[11] above, wherein the charge generation layer further contains a rare earth metal, and the rare earth metal is Yb.

[13] An organic EL device that emits light in response to electrical energy, and in which at least an electron injection layer and an emitting layer are present between an anode and a cathode, and the electron injection layer contains the compound according to any one of [1] to [5] above.

[14] The organic EL device according to

[13] above, wherein the electron injection layer further contains an alkali metal or a rare earth metal.

[15] The organic EL device according to any one of [6] to

[14] above, wherein the emitting layer contains a compound represented by the following general formula (3):

[0012]

[0013] (In general formula (3), ring Za, ring Zb, and ring Zc are each independently a substituted or unsubstituted aryl ring having 6 to 30 ring carbon atoms or a substituted or unsubstituted heteroaryl ring having 5 to 30 ring atoms; Z１ and Z ２ are each independently an oxygen atom, NRa (a nitrogen atom having a substituent Ra), or a sulfur atom, and Z １ is NRa, the substituent Ra may or may not be bonded to the Za ring or the Zb ring to form a ring; ２ is NRa, the substituent Ra may or may not bond with the Zb ring or the Zc ring to form a ring; Ra each independently represents a substituted or unsubstituted aryl group having 6 to 30 ring carbon atoms, a substituted or unsubstituted heteroaryl group having 5 to 30 ring atoms, or a substituted or unsubstituted alkyl group having 1 to 30 carbon atoms; Y represents a boron atom, a phosphorus atom, SiRb (a silicon atom having a substituent Rb), P=O, or P=S; Rb each independently represents a substituted or unsubstituted aryl group having 6 to 30 ring carbon atoms, a substituted or unsubstituted heteroaryl group having 5 to 30 ring atoms, or a substituted or unsubstituted alkyl group having 1 to 30 carbon atoms.)

[16] A display device comprising the organic EL element according to any one of [6] to

[15] above.

[17] A lighting device comprising the organic EL element according to any one of [6] to

[15] above.

[0014] According to the present invention, an organic EL element having excellent luminous efficiency and durable life can be provided.

[0015] Preferred embodiments of the compound, organic EL element, display device, and lighting device according to the present invention will be described in detail below. However, the present invention is not limited to the following embodiments and can be practiced with various modifications depending on the purpose and application.

[0016] (Compound) The compound according to the first embodiment of the present invention is a compound represented by general formula (1).

[0017]

[0018] In the general formula (1), Ar １０１ ~Ar １０２ are each independently a substituted or unsubstituted aryl group or a substituted or unsubstituted heteroaryl group, Ar １０３is a substituted or unsubstituted arylene group or a substituted or unsubstituted heteroarylene group, Ar １０１ ~Ar １０３ At least one of L is a group containing a nitrogen atom. １０１ R is a single bond, a substituted or unsubstituted phenylene group, a substituted or unsubstituted naphthylene group, a substituted or unsubstituted pyridylene group, a substituted or unsubstituted pyridazylene group, a substituted or unsubstituted pyrazylene group, a substituted or unsubstituted pyrimidylene group, or a substituted or unsubstituted triazylene group. １０１ ~R １０７ are each independently selected from the group consisting of a hydrogen atom, an alkyl group, an alkoxy group, a phosphoryl group, a halogen atom, a cyano group, a substituted or unsubstituted aryl group, and a substituted or unsubstituted heteroaryl group.

[0019] The compound according to the second embodiment of the present invention is a compound represented by general formula (2).

[0020]

[0021] In the general formula (2), Ar ２０１ ~Ar ２０２ are each independently a substituted or unsubstituted aryl group or an unsubstituted heteroaryl group having 10 or less carbon atoms, and Ar ２０３ is a substituted or unsubstituted arylene group or an unsubstituted heteroarylene group having 10 or less carbon atoms, Ar ２０１ ~Ar ２０３ At least one of Ar is a group containing a nitrogen atom in the ring. ２０１ and Ar ２０２ , Ar ２０２ and Ar ２０３ , Ar ２０１ and Ar ２０３ At least one pair of L is linked to each other to form a ring structure. ２０１ R is a single bond, a substituted or unsubstituted phenylene group, a substituted or unsubstituted naphthylene group, a substituted or unsubstituted pyridylene group, a substituted or unsubstituted pyridazylene group, a substituted or unsubstituted pyrazylene group, a substituted or unsubstituted pyrimidylene group, or a substituted or unsubstituted triazylene group.２０１ is an unsubstituted aryl group or an unsubstituted heteroaryl group, and R ２０２ ~R ２０７ are each independently selected from the group consisting of a hydrogen atom, an alkyl group, an alkoxy group, a phosphoryl group, a halogen atom, a cyano group, a substituted or unsubstituted aryl group, and a substituted or unsubstituted heteroaryl group.

[0022] The following explanation applies to the compounds according to the first and second embodiments, unless otherwise specified.

[0023] In all of the above groups, the hydrogen atom may be replaced with a deuterium atom. The same applies to "substituted or unsubstituted" in the compounds or partial structures thereof described below.

[0024] The alkyl group refers to a saturated aliphatic hydrocarbon group such as a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, or a tert-butyl group, which may or may not have a substituent. The number of carbon atoms in the alkyl group is not particularly limited, but from the standpoint of availability and cost, it is preferably in the range of 1 to 20, more preferably 1 to 8. The number of carbon atoms here includes the number of carbon atoms contained in a substituent bonded to the alkyl group, and this also applies to other substituents that specify the number of carbon atoms (in the case of other substituents, the "alkyl group" part of "the number of carbon atoms here" refers to the substituent bonded to the alkyl group" should be read as the name of the other substituent).

[0025] The alkoxy group refers to a group in which an alkyl group is bonded to oxygen, such as a methoxy group, an ethoxy group, an n-propoxy group, an isopropoxy group, an n-butoxy group, a sec-butoxy group, or a tert-butoxy group, which may or may not have a substituent. The number of carbon atoms in the alkoxy group is not particularly limited, but from the standpoints of availability and cost, it is usually in the range of 1 to 20, more preferably 1 to 8.

[0026] The aryl group refers to an aromatic hydrocarbon group such as a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a fluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenanthryl group, an anthracenyl group, a benzophenanthryl group, a benzanthracenyl group, a chrysenyl group, a pyrenyl group, a fluoranthenyl group, a triphenylenyl group, a benzofluoranthenyl group, a dibenzoanthracenyl group, a perylenyl group, or a helicenyl group. Among these, a phenyl group or a biphenyl group is preferred. This may or may not have a substituent.

[0027] Furthermore, when a phenyl group (including the phenylene and phenyl moieties in groups such as a biphenyl group) has a substituent, if two adjacent carbon atoms in the phenyl group each have a substituent, these substituents may form a ring structure. Depending on the structure, the resulting group may fall into one or more of the categories of a "substituted phenyl group," an "aryl group having a structure in which two or more rings are fused," and a "heteroaryl group having a structure in which two or more rings are fused."

[0028] Examples of heteroaryl groups include pyridyl, pyrrole, furanyl, thiophenyl, quinolinyl, isoquinolinyl, pyrazinyl, pyrimidyl, pyridazinyl, triazinyl, naphthyridinyl, cinnolinyl, phthalazinyl, quinoxalinyl, quinazolinyl, benzofuranyl, benzothiophenyl, indolyl, dibenzofuranyl, dibenzothiophenyl, benzophosphole, benzophosphole oxide, dibenzophosphole, and dibenzophosphole. It refers to a cyclic aromatic group having one or more atoms other than carbon in the ring, such as an oxide group, a carbazolyl group, a benzocarbazolyl group, a carbolinyl group, an indolocarbazolyl group, a benzofurocarbazolyl group, a benzothienocarbazolyl group, a dihydroindenocarbazolyl group, a benzoquinolinyl group, an acridinyl group, a dibenzoacridinyl group, an imidazolyl group, a benzimidazolyl group, an imidazopyridyl group, a benzoxazolyl group, a benzothiazolyl group, a naphthazinyl group, or a phenanthrolinyl group, provided that a naphthyridinyl group refers to any of a 1,5-naphthyridinyl group, a 1,6-naphthyridinyl group, a 1,7-naphthyridinyl group, a 1,8-naphthyridinyl group, a 2,6-naphthyridinyl group, and a 2,7-naphthyridinyl group. The heteroaryl group may or may not have a substituent. The number of ring atoms is not particularly limited, but is preferably 3 to 40, more preferably 3 to 30.

[0029] As conventional phenanthroline compounds containing a pyridylamine skeleton or a carboline skeleton, for example, Patent Documents 1 to 6 disclose compounds U, V, W, X, Y, and Z represented by the following formulas.

[0030]

[0031] However, even when these compounds are used as materials for organic EL devices in the electron injection layer, electron transport layer, or charge generation layer, they still do not provide sufficient performance for the characteristics required in recent years, and therefore, compounds that enable further improvements in performance in terms of luminous efficiency and durability are desired.

[0032] For example, a derivative having a pyridylamine structure with a phenanthrenyl group as a linking group, such as Compound U, has a problem in that the intermolecular interaction is too strong due to the high planarity of the phenanthrenyl group, resulting in high crystallinity and a decrease in handleability and film stability.

[0033] In a phenanthroline derivative having a carboline skeleton and an unsubstituted terminal, such as Compound V, the coordination site of the phenanthroline is sterically vacant and the carboline skeleton is a fused ring structure. For these reasons, the crystallinity becomes excessively high, which leads to problems such as poor handling and poor film stability.

[0034] In phenanthroline derivatives with terminal phenyl alkoxide substitutions, such as Compound W, the coordination between the phenanthroline and metal is inhibited by the formation of a coordination state between the lithium alkoxide and the nitrogen atom in the adjacent phenanthroline skeleton, resulting in reduced charge transport properties, increased driving voltage, and issues with luminous efficiency and durability.

[0035] Phenanthroline derivatives such as Compound X, which contain a phenylquinolyl group in the partial structure of the carboline skeleton, have a problem in that they contain a fused ring structure and a substituted heteroaryl group, and therefore have excessively high intermolecular interactions, resulting in high crystallinity and reduced handleability and film stability.

[0036] Phenanthroline derivatives such as Compound Y, which contain a heteroaryl group with a large carbon number, such as a phenanthroline group, in the partial structure of the carboline skeleton, have a problem in that the intermolecular interaction is too strong due to the inclusion of a fused ring structure and a heteroaryl group with a large carbon number, resulting in high crystallinity and a decrease in handleability and film stability.

[0037] Phenanthroline derivatives having a triphenylamine skeleton bridged with dimethylmethylene groups, such as Compound Z, are substituted with alkylene groups that have low thermal stability, and therefore there was concern that they would decompose during sublimation purification or vapor deposition.

[0038] In their investigations into the improvement, the present inventors focused on the effects of the pyridylamine skeleton and the phenanthroline skeleton, and the linking groups therebetween, and found that the compound represented by general formula (1) or (2) can provide an organic EL device having excellent luminous efficiency and durable life.

[0039] <Compound represented by general formula (1)> In general formula (1), Ar １０１ ~Ar １０３ When at least one of Ar is a group containing a nitrogen atom, the electron transporting property is higher than when none of Ar is a group containing a nitrogen atom, and an organic EL device having a low driving voltage can be obtained. １０１ and Ar １０２ , Ar １０２ and Ar １０３ , Ar １０１ and Ar １０３ In any pair, the groups do not have a bond connecting them to each other.

[0040] The phenanthroline skeleton, which has high metal coordination properties, contributes to improving the charge generation efficiency by forming a coordination state with the metal. However, since the metal coordination state is unstable with the phenanthroline skeleton alone, the equilibrium between the coordination state and the non-coordinated state of the phenanthroline skeleton tends to favor the formation of the non-coordinated state, which causes a problem of an increase in driving voltage over time. １０１ ~Ar １０３ When at least one of Ar is a group containing a nitrogen atom, the metal coordination state of the phenanthroline skeleton is stable, and therefore it is possible to suppress changes in driving voltage when the device is operated. The compound represented by general formula (1) is considered to significantly contribute to the stabilization of the metal coordination state by combining the high electron accepting property and high chemical stability of the nitrogen atom-containing group and the high metal coordination property of the phenanthroline skeleton. １０１ ~Ar １０３ When at least one of the groups contains a nitrogen atom, the nitrogen atom is Ar １０１ ~Ar １０３This also includes not only those containing a nitrogen atom on an aryl group or arylene group having a bond of the above formula, but also those in which a group containing a nitrogen atom, such as a pyridyl group, is bonded as a substituent to a phenyl group or phenylene group.

[0041] From the viewpoint of improving the film stability and further improving the durability life of the organic EL element, Ar １０１ ~Ar １０２ are each independently selected from a substituted or unsubstituted phenyl group, a substituted or unsubstituted naphthyl group, a substituted or unsubstituted anthryl group, a substituted or unsubstituted phenanthrenyl group, a substituted or unsubstituted pyrenyl group, a substituted or unsubstituted pyridyl group, a substituted or unsubstituted pyrimidyl group, and a substituted or unsubstituted quinoxalinyl group; Ar １０３ is preferably selected from a substituted or unsubstituted phenylene group, a substituted or unsubstituted naphthylene group, a substituted or unsubstituted anthrylene group, a substituted or unsubstituted phenanthrenylene group, a substituted or unsubstituted pyrenylene group, a substituted or unsubstituted pyridylene group, a substituted or unsubstituted pyrimidylene group, and a substituted or unsubstituted quinoxalinylene group. １０１ ~Ar １０３ are each independently selected from a substituted or unsubstituted phenyl group, a substituted or unsubstituted naphthyl group, a substituted or unsubstituted pyridyl group, a substituted or unsubstituted pyrimidyl group, and a substituted or unsubstituted quinoxalinyl group. １０１ ~Ar １０２ are each independently a substituted or unsubstituted phenyl group or a substituted or unsubstituted pyridyl group, and Ar １０３ is more preferably a substituted or unsubstituted phenylene group or a substituted or unsubstituted pyridylene group.

[0042] In general formula (1), L １０１represents a single bond, a substituted or unsubstituted phenylene group, a substituted or unsubstituted naphthylene group, a substituted or unsubstituted pyridylene group, a substituted or unsubstituted pyridazylene group, a substituted or unsubstituted pyrazylene group, a substituted or unsubstituted pyrimidylene group, or a substituted or unsubstituted triazylene group. １０１ Although L may be a single bond, in the present invention, the term "linking group" will be used to refer to both single bonds for the sake of convenience. １０１ When L is not a single bond, these groups can improve the stability of the compound without reducing the charge transport property of the compound. １０１ is a single bond, the interaction between the phenanthroline skeleton and the pyridylamine skeleton can be made stronger, and the luminous efficiency and durable life can be improved.

[0043] From the viewpoint of suppressing excessive improvement in crystallinity, improving film quality stability, and further improving luminous efficiency and durability, L １０１ is more preferably a single bond, an unsubstituted phenylene group, an unsubstituted naphthylene group, an unsubstituted pyridylene group, an unsubstituted pyridazylene group, an unsubstituted pyrazylene group, an unsubstituted pyrimidylene group, or an unsubstituted triazylene group. １０１ More preferably, is a phenylene group, a naphthylene group, or a pyridylene group.

[0044] Also, R １０１ ~R １０７ are preferably each independently selected from the group consisting of a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, and a substituted or unsubstituted heteroaryl group.

[0045] In addition, from the viewpoint of improving the film stability and further improving the durability and life of the organic EL element, R １０２ ~R １０７ is more preferably a hydrogen atom. １０１ is preferably a hydrogen atom, a phenyl group, or a naphthyl group. １０１ When R is a hydrogen atom, the metal coordination ability of the compound represented by general formula (1) is further improved, and the driving voltage can be reduced. １０１When is a phenyl group or a naphthyl group, the film stability is further improved, and the durability life of the organic EL element can be further improved.

[0046] <Compound represented by general formula (2)> In general formula (2), Ar ２０１ ~Ar ２０３ When at least one of the groups contains a nitrogen atom, the electron transporting property is higher than when none of the groups contains a nitrogen atom, and an organic EL element having a low driving voltage can be obtained.

[0047] Also, Ar ２０１ and Ar ２０２ , Ar ２０２ and Ar ２０３ , Ar ２０１ and Ar ２０３ When at least one of the groups is linked to each other to form a ring structure, the electron transport property is improved, which contributes to a reduction in the driving voltage, and thus the luminous efficiency and the durability life can be further improved.

[0048] The phenanthroline skeleton, which has high metal coordination properties, contributes to improving the charge generation efficiency by forming a coordination state with the metal. However, since the metal coordination state is unstable with the phenanthroline skeleton alone, the equilibrium between the coordination state and the non-coordinated state of the phenanthroline skeleton tends to favor the formation of the non-coordinated state, which causes a problem of an increase in driving voltage over time. ２０１ ~Ar ２０３ When at least one of Ar is a group containing a nitrogen atom, the metal coordination state of the phenanthroline skeleton is stable, and therefore it is possible to suppress changes in driving voltage when the device is operated. The compound represented by general formula (2) is considered to significantly contribute to the stabilization of the metal coordination state by combining the high electron accepting property and high chemical stability of the nitrogen atom-containing group and the high metal coordination property of the phenanthroline skeleton. ２０１ ~Ar ２０３ When at least one of the groups contains a nitrogen atom, the nitrogen atom is Ar ２０１ ~Ar ２０３This also includes, for example, a phenyl group or phenylene group to which a group containing a nitrogen atom, such as a pyridyl group, is bonded as a substituent.

[0049] Also, Ar ２０１ and Ar ２０２ , Ar ２０２ and Ar ２０３ , Ar ２０１ and Ar ２０３ In the general formula (2), at least one of the pairs is a fused ring structure having a ring structure in which the rings are linked to each other, and therefore there is a concern that excessive crystallization may cause a decrease in electron transport properties. ２０１ ~Ar ２０２ is an unsubstituted heteroaryl group having 10 or less carbon atoms, and Ar ２０３ is preferably an unsubstituted heteroarylene group having 10 or less carbon atoms.

[0050] From the viewpoint of improving the film stability and further improving the durability life of the organic EL element, Ar ２０１ ~Ar ２０２ are each independently selected from a substituted or unsubstituted phenyl group, a substituted or unsubstituted naphthyl group, a substituted or unsubstituted anthryl group, a substituted or unsubstituted phenanthrenyl group, a substituted or unsubstituted pyrenyl group, a substituted or unsubstituted pyridyl group, a substituted or unsubstituted pyrimidyl group, and a substituted or unsubstituted quinoxalinyl group; Ar ２０３ is preferably selected from a substituted or unsubstituted phenylene group, a substituted or unsubstituted naphthylene group, a substituted or unsubstituted anthrylene group, a substituted or unsubstituted phenanthrenylene group, a substituted or unsubstituted pyrenylene group, a substituted or unsubstituted pyridylene group, a substituted or unsubstituted pyrimidylene group, and a substituted or unsubstituted quinoxalinylene group. ２０１ ~Ar ２０２are each independently selected from a substituted or unsubstituted phenyl group, a substituted or unsubstituted naphthyl group, a substituted or unsubstituted pyridyl group, a substituted or unsubstituted pyrimidyl group, and a substituted or unsubstituted quinoxalinyl group; Ar ２０３ is more preferably selected from a substituted or unsubstituted phenylene group, a substituted or unsubstituted naphthylene group, a substituted or unsubstituted pyridylene group, a substituted or unsubstituted pyrimidylene group, and a substituted or unsubstituted quinoxalinylene group. ２０１ ~Ar ２０２ are each independently a substituted or unsubstituted phenyl group or a substituted or unsubstituted pyridyl group, and Ar ２０３ is more preferably a substituted or unsubstituted phenylene group or a substituted or unsubstituted pyridylene group.

[0051] In general formula (2), L ２０１ represents a single bond, a substituted or unsubstituted phenylene group, a substituted or unsubstituted naphthylene group, a substituted or unsubstituted pyridylene group, a substituted or unsubstituted pyridazylene group, a substituted or unsubstituted pyrazylene group, a substituted or unsubstituted pyrimidylene group, or a substituted or unsubstituted triazylene group. ２０１ Although L may be a single bond, in the present invention, the term "linking group" will be used to refer to both single bonds for the sake of convenience. ２０１ When L is not a single bond, these groups can improve the stability of the compound without reducing the charge transport property of the compound. ２０１ is a single bond, the interaction between the phenanthroline skeleton and the pyridylamine skeleton can be made stronger, and the luminous efficiency and durable life can be improved.

[0052] From the viewpoint of suppressing excessive improvement in crystallinity, improving film quality stability, and further improving luminous efficiency and durability, L ２０１ is more preferably a single bond, an unsubstituted phenylene group, an unsubstituted naphthylene group, an unsubstituted pyridylene group, an unsubstituted pyridazylene group, an unsubstituted pyrazylene group, an unsubstituted pyrimidylene group, or an unsubstituted triazylene group.２０１ More preferably, is a phenylene group, a naphthylene group, or a pyridylene group.

[0053] In general formula (2), R ２０１ is an unsubstituted aryl group or an unsubstituted heteroaryl group. This contributes to improving the electron transport property without reducing the metal coordination ability of the phenanthroline skeleton. ２０２ ~R ２０７ are preferably each independently selected from the group consisting of a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, and a substituted or unsubstituted heteroaryl group.

[0054] In addition, from the viewpoint of improving the film stability and further improving the durability and life of the organic EL element, R ２０２ ~R ２０７ is more preferably a hydrogen atom.

[0055] In addition, Ar in the general formula (1) １０１ ~Ar １０２ and Ar in general formula (2). ２０１ ~Ar ２０２ It is more preferable that at least one of the groups is independently an aryl group substituted with a nitrogen atom-containing group. By including an aryl group substituted with a nitrogen atom-containing group, the two functions of stabilizing film quality and improving electron transport properties are simultaneously achieved, and the increase in driving voltage change over time can be further suppressed. Furthermore, the nitrogen atom-containing group is preferably selected from the group consisting of a pyridyl group, a pyrimidyl group, a pyridazyl group, a triazine group, a quinolyl group, and a quinoxalyl group, and from the viewpoints of ease of availability and cost, a pyridyl group or a quinolyl group is more preferable. The aryl group is preferably selected from the group consisting of a phenyl group, a naphthyl group, an anthryl group, a phenanthrenyl group, and a pyrenyl group, and from the viewpoint of suppressing excessive crystallinity, a phenyl group, a naphthyl group, or an anthryl group is more preferable.

[0056] The molecular weight of the compound represented by general formula (1) or (2) is preferably 400 or more from the viewpoint of suppressing crystallization and improving the stability of film quality, while the molecular weight of the compound represented by general formula (1) or (2) is preferably 800 or less from the viewpoint of improving processability during sublimation purification and vapor deposition.

[0057] Examples of the compound represented by general formula (1) include the compounds shown below. Note that the following are merely examples, and compounds other than those explicitly listed here can also be preferably used as long as they are represented by general formula (1).

[0058]

[0059]

[0060]

[0061]

[0062]

[0063]

[0064]

[0065]

[0066]

[0067]

[0068]

[0069]

[0070]

[0071]

[0072]

[0073]

[0074]

[0075]

[0076]

[0077]

[0078]

[0079]

[0080]

[0081]

[0082]

[0083]

[0084]

[0085]

[0086]

[0087]

[0088]

[0089]

[0090]

[0091]

[0092]

[0093]

[0094] Examples of the compound represented by general formula (2) include the compounds shown below. Note that the following are merely examples, and compounds other than those explicitly listed here can also be preferably used as long as they are represented by general formula (2).

[0095]

[0096]

[0097]

[0098]

[0099]

[0100]

[0101]

[0102]

[0103]

[0104]

[0105]

[0106]

[0107]

[0108]

[0109]

[0110]

[0111]

[0112]

[0113]

[0114]

[0115] The compound represented by general formula (1) or (2) can be synthesized by a known synthesis method, such as, but not limited to, a coupling reaction of an aryl halide derivative with an arylboronic acid derivative using palladium.

[0116] (Organic EL element) Generally, an organic EL element is a type of so-called light-emitting element that emits light when a voltage is applied, and has an anode, a cathode, and an organic layer interposed between the anode and the cathode, and the organic layer emits light when exposed to electrical energy.

[0117] The layer configuration between the anode and the cathode in the organic EL element may be a configuration consisting of only an emitting layer, or may be a laminate configuration such as 1) emitting layer / electron transport layer, 2) hole transport layer / emitting layer, 3) hole transport layer / emitting layer / electron transport layer, 4) hole injection layer / hole transport layer / emitting layer / electron transport layer, 5) hole transport layer / emitting layer / electron transport layer / electron injection layer, 6) hole injection layer / hole transport layer / emitting layer / electron transport layer / electron injection layer, or 7) hole injection layer / hole transport layer / emitting layer / hole blocking layer / electron transport layer / electron injection layer.

[0118] The organic EL element may be a tandem type in which a plurality of the above-described laminated structures are laminated via an intermediate layer. The intermediate layer is generally also called an intermediate electrode, an intermediate conductive layer, a charge generation layer, an electron extraction layer, a connection layer, or an intermediate insulating layer, and a known layer structure can be used. Specific examples of the tandem type include laminated structures including a charge generation layer as an intermediate layer between an anode and a cathode, such as 8) hole transport layer / light-emitting layer / electron transport layer / charge generation layer / hole transport layer / light-emitting layer / electron transport layer, or 9) hole injection layer / hole transport layer / light-emitting layer / electron transport layer / electron injection layer / charge generation layer / hole injection layer / hole transport layer / light-emitting layer / electron transport layer / electron injection layer.

[0119] Each of the above layers may be a single layer or multiple layers, and may be doped. In particular, the electron injection layer and the charge generation layer are preferably metal-doped layers doped with a metal, which can improve the electron transport ability and the electron injection ability into adjacent layers. In addition to the above layers, a protective layer (cap layer) may be further provided, which can further improve the luminous efficiency by optical interference effect.

[0120] The compound of the present invention represented by general formula (1) or general formula (2) may be used in any of the above-mentioned layers in the organic EL device, but is particularly preferably used in the electron transport layer, charge generation layer, or electron injection layer.

[0121] The organic EL element of the present invention is an organic EL element that emits light in response to electric energy, and preferred configurations include a configuration in which at least an electron transport layer and an emitting layer are present between an anode and a cathode, and the electron transport layer contains a compound represented by general formula (1) or general formula (2); a configuration in which at least a charge generation layer and an emitting layer are present between an anode and a cathode, and the charge generation layer contains a compound represented by general formula (1) or general formula (2); and a configuration in which at least an electron injection layer and an emitting layer are present between an anode and a cathode, and the electron injection layer contains a compound represented by general formula (1) or general formula (2).

[0122] In the organic EL element of the present invention, the anode and cathode have the role of supplying a current necessary for the element to emit light, and it is desirable that at least one of them is transparent or semi-transparent in order to extract light. Usually, the anode formed on the substrate is used as a transparent electrode.

[0123] (Substrate) In order to maintain the mechanical strength of the organic EL element, it is preferable to form the organic EL element on a substrate. Examples of the substrate include glass substrates such as soda glass and alkali-free glass, and plastic substrates. The thickness of the glass substrate is sufficient to maintain the mechanical strength, and 0.5 mm or more is sufficient. As for the glass material, it is preferable that the amount of ions eluted from the glass is small, and alkali-free glass is preferable. In addition, SiO ２ Soda lime glass coated with a barrier coating such as the above is also commercially available and can be used.

[0124] (Anode) The material used for the anode is preferably a substance that can efficiently inject holes into the organic layer. Furthermore, it is preferably transparent or translucent in order to extract light. Examples of such substances include conductive metal oxides such as zinc oxide, tin oxide, indium oxide, indium tin oxide (ITO), and indium zinc oxide (IZO); metals such as gold, silver, and chromium; inorganic conductive substances such as copper iodide and copper sulfide; and conductive polymers such as polythiophene, polypyrrole, and polyaniline. Among these, ITO glass and NESA glass are preferred. These substances may be used alone, or multiple substances may be used in combination. When multiple substances are used in combination, multiple layers composed of different substances may be stacked, or a layer composed of a material containing a mixture of multiple substances may be used.

[0125] (Cathode) The material used for the cathode is not particularly limited as long as it can efficiently inject electrons into the light-emitting layer. Examples of materials used for the cathode include metals such as platinum, gold, silver, copper, iron, tin, aluminum, and indium, as well as alloys and multilayer stacks of these metals with low-work-function metals such as lithium, sodium, potassium, calcium, and magnesium. Among these, aluminum, silver, and magnesium are preferred as the main components in terms of electrical resistance, ease of film formation, film stability, and light-emitting efficiency, and magnesium and magnesium are more preferred because they facilitate electron injection into the electron transport layer and the electron injection layer.

[0126] (Protective Layer) For cathode protection, it is preferable to laminate a protective layer (capping layer) on the cathode. The material used as the protective layer (capping material) is not particularly limited, but examples include metals such as platinum, gold, silver, copper, iron, tin, aluminum, and indium, alloys using these metals, inorganic substances such as silica, titania, and silicon nitride, and organic polymer compounds such as polyvinyl alcohol, polyvinyl chloride, and hydrocarbon-based polymer compounds. Compounds represented by general formula (1) can also be used as capping materials. However, when the organic EL element has a device structure in which light is extracted from the cathode side (top emission structure), it is preferable that the capping material has optical transparency in the visible light region. It is also possible to form a single layer using a plurality of materials used for the cathode and the protective layer, and use one of these layers as the cathode.

[0127] (Hole injection layer) The hole injection layer is a layer disposed between the anode and the hole transport layer. The presence of the hole injection layer between the hole transport layer and the anode is preferable because it allows driving at a lower voltage, thereby improving the durability life and further improving the carrier balance of the element, thereby improving the luminous efficiency.

[0128] Known substances are used as materials for the hole injection layer. Hereinafter, the material for the hole injection layer may be abbreviated as hole injection material. Examples of materials used for hole injection materials include heterocyclic compounds such as benzidine derivatives, starburst arylamine compounds, triarylamine derivatives, biscarbazole derivatives, pyrazoline derivatives, stilbene compounds, fluorene compounds, hydrazone compounds, benzofuran derivatives, thiophene derivatives, oxadiazole derivatives, phthalocyanine derivatives, and porphyrin derivatives, and polymers such as polycarbonates and styrene derivatives having the above-mentioned monomers in their side chains, polythiophenes, polyanilines, polyfluorenes, polyvinylcarbazoles, and polysilanes. From the viewpoint of smoothly injecting holes from the anode to the hole transport layer, benzidine derivatives, starburst arylamine compounds, and fluorene compounds are more preferably used. These substances may be used alone or in combination of two or more. The hole injection layer may be formed by stacking layers made of a plurality of these hole injection materials.

[0129] Preferred embodiments of the hole injection layer include an embodiment in which the hole injection layer is composed solely of the acceptor compound described below, or an embodiment in which the hole injection layer is composed of the hole injection material doped with the acceptor compound described below. These embodiments are more preferable because they allow the device to be driven at a lower voltage, thereby not only improving the durability and lifespan but also achieving a more pronounced effect of improving the carrier balance of the device and improving the luminous efficiency. Here, the acceptor compound is a compound that forms a charge-transfer complex with a substance constituting the adjacent hole transport layer when used as a single layer film, or with a substance used as the hole injection material when used as a dopant. The use of such an acceptor compound improves the conductivity of the hole injection layer, further contributing to a reduction in the device's driving voltage and further improving the luminous efficiency and lifespan.

[0130] Known compounds can be used as the acceptor compound. Examples include metal chlorides, metal oxides such as molybdenum oxide, charge-transfer complexes, organic compounds having a nitro group, a cyano group, a halogen, or a trifluoromethyl group in the molecule, quinone compounds, acid anhydride compounds, and fullerenes. Among these, metal oxides and cyano group-containing compounds are preferred because they are easy to handle and vapor-deposit, and therefore the above-mentioned effects can be easily obtained. Whether the hole injection layer is composed of an acceptor compound alone or the substance used as the hole injection material is doped with the acceptor compound, the hole injection layer may be a single layer or may be composed of multiple layers stacked together.

[0131] (Hole Transport Layer) The hole transport layer is a layer that transports holes injected from the anode to the light emitting layer. The hole transport layer may be a single layer or may be configured by laminating multiple layers.

[0132]

[0033] Examples of the substance used in the hole transport layer include those exemplified as the substance used in the hole injection layer. A hole transport layer that serves to improve the efficiency of hole injection from the substance used in the anode is particularly called a hole injection layer, and in a broad sense, the hole injection layer is also included in the hole transport layer. From the viewpoint of smoothly injecting and transporting holes to the light-emitting layer, triarylamine derivatives and benzidine derivatives are more preferred.

[0133] (Light-Emitting Layer) The light-emitting layer may be a single layer or multiple layers, each formed from light-emitting materials (host material, dopant material). These layers may be a mixture of a host material and a dopant material, a single host material, or a mixture of two host materials and one dopant material. That is, in the organic EL device according to the embodiment of the present invention, only the host material or the dopant material may emit light in each light-emitting layer, or both the host material and the dopant material may emit light. From the viewpoint of efficiently utilizing electrical energy and obtaining light emission with high color purity, it is preferable that the light-emitting layer be a mixture of a host material and a dopant material. Furthermore, the host material and the dopant material may each be one type, or a combination of multiple types. The dopant material may be contained entirely or partially in the host material. The dopant material may be laminated or dispersed. The light-emitting color can be controlled by selecting the dopant material. The amount of the dopant material is preferably 30% by weight or less, more preferably 20% by weight or less, based on the host material, from the viewpoint of suppressing concentration quenching. The doping method can be a co-evaporation method with the host material, or the dopant material may be mixed with the host material in advance and then evaporated simultaneously.

[0134] Known compounds can be used as the light-emitting material.

[0135] For example, the host material contained in the light-emitting material does not need to be limited to only one compound, and a mixture of multiple compounds may be used. Furthermore, the compounds may be laminated. Known compounds can be used as the host material. Examples of compounds include, but are not limited to, compounds having a condensed aryl ring such as naphthalene, anthracene, phenanthrene, pyrene, chrysene, naphthacene, triphenylene, perylene, fluoranthene, fluorene, and indene, and derivatives thereof; aromatic amine derivatives such as N,N'-dinaphthyl-N,N'-diphenyl-4,4'-diphenyl-1,1'-diamine; metal chelated oxinoid compounds such as tris(8-quinolinato)aluminum(III); bisstyryl derivatives such as distyrylbenzene derivatives; Examples of the host include tetraphenylbutadiene derivatives, indene derivatives, coumarin derivatives, oxadiazole derivatives, pyrrolopyridine derivatives, perinone derivatives, cyclopentadiene derivatives, pyrrolopyrrole derivatives, thiadiazolopyridine derivatives, dibenzofuran derivatives, carbazole derivatives, indolocarbazole derivatives, triazine derivatives, and polymers such as polyphenylenevinylene derivatives, polyparaphenylene derivatives, polyfluorene derivatives, polyvinylcarbazole derivatives, and polythiophene derivatives. Among these, preferred examples of the host used when the light-emitting layer exhibits triplet emission (phosphorescence emission) include metal-chelated oxinoid compounds, dibenzofuran derivatives, dibenzothiophene derivatives, carbazole derivatives, indolocarbazole derivatives, triazine derivatives, and triphenylene derivatives.

[0136] Examples of compounds used as dopant materials contained in the light-emitting material include compounds having an aryl ring and derivatives thereof, compounds having a heteroaryl ring and derivatives thereof, distyrylbenzene derivatives, aminostyryl derivatives, aromatic acetylene derivatives, tetraphenylbutadiene derivatives, stilbene derivatives, aldazine derivatives, pyrromethene derivatives, diketopyrrolo[3,4-c]pyrrole derivatives, coumarin derivatives, azole derivatives, metal complexes thereof, aromatic amine derivatives, and compounds represented by the following general formula (3). Among these, dopants containing a diamine skeleton and dopants containing a fluoranthene skeleton can further improve light-emitting efficiency, and compounds represented by the following general formula (3) can further improve light-emitting efficiency and durable life. It is particularly preferable that the light-emitting layer contains a compound represented by the following general formula (3).

[0137]

[0138] In general formula (3), ring Za, ring Zb, and ring Zc are each independently a substituted or unsubstituted aryl ring having 6 to 30 ring carbon atoms or a substituted or unsubstituted heteroaryl ring having 5 to 30 ring atoms. Ring Za, ring Zb, and ring Zc are each preferably independently a substituted or unsubstituted aryl ring having 6 to 30 ring carbon atoms. Z １ and Z ２ are each independently an oxygen atom, NRa (a nitrogen atom having a substituent Ra), or a sulfur atom, and Z １ is NRa, the substituent Ra may or may not be bonded to the Za ring or the Zb ring to form a ring; ２ When is NRa, the substituent Ra may or may not bond with the Zb ring or the Zc ring to form a ring. Each Ra is independently a substituted or unsubstituted aryl group having 6 to 30 ring carbon atoms, a substituted or unsubstituted heteroaryl group having 5 to 30 ring atoms, or a substituted or unsubstituted alkyl group having 1 to 30 carbon atoms. Z １ and Z ２are each preferably NRa, and Ra is a substituted or unsubstituted aryl group having 6 to 30 ring carbon atoms. Y is a boron atom, a phosphorus atom, SiRb (a silicon atom having a substituent Rb), P=O, or P=S. Rb is each independently a substituted or unsubstituted aryl group having 6 to 30 ring carbon atoms, a substituted or unsubstituted heteroaryl group having 5 to 30 ring atoms, or a substituted or unsubstituted alkyl group having 1 to 30 carbon atoms. Y is preferably a boron atom.

[0139] In general (3), when Ra, Rb, and all of the Za to Zc rings are substituted, the substituents are preferably alkyl groups, cycloalkyl groups, heterocyclic groups, alkenyl groups, cycloalkenyl groups, alkynyl groups, aryl groups, heteroaryl groups, hydroxyl groups, thiol groups, alkoxy groups, alkylthio groups, aryl ether groups, aryl thioether groups, halogens, cyano groups, aldehyde groups, acyl groups, carboxyl groups, ester groups, amide groups, sulfonyl groups, sulfonate ester groups, sulfonamide groups, amino groups, nitro groups, silyl groups, siloxanyl groups, boryl groups, or oxo groups. These substituents may be further substituted with the above-mentioned substituents.

[0140] Examples of the alkyl group, alkoxy group, aryl group and heteroaryl group include those exemplified as the substituent in general formula (1).

[0141] The cycloalkyl group refers to a saturated alicyclic hydrocarbon group, such as a cyclopropyl group, a cyclohexyl group, a norbornyl group, or an adamantyl group, which may or may not have a substituent. The number of ring carbon atoms is not particularly limited, but is preferably in the range of 3 to 20.

[0142] The heterocyclic group refers to an aliphatic ring having atoms other than carbon atoms in the ring, such as a pyran ring, a piperidine ring, or a cyclic amide, which may or may not have a substituent. The number of ring atoms is not particularly limited, but is preferably in the range of 3 to 20.

[0143] The alkenyl group refers to an unsaturated aliphatic hydrocarbon group containing a double bond, such as a vinyl group, an allyl group, or a butadienyl group, which may or may not have a substituent. The number of carbon atoms in the alkenyl group is not particularly limited, but is preferably in the range of 2 to 20.

[0144] The cycloalkenyl group refers to an unsaturated alicyclic hydrocarbon group containing a double bond, such as a cyclopentenyl group, a cyclopentadienyl group, or a cyclohexenyl group, which may or may not have a substituent.

[0145] The alkynyl group refers to an unsaturated aliphatic hydrocarbon group containing a triple bond, such as an ethynyl group, which may or may not have a substituent. The number of carbon atoms in the alkynyl group is not particularly limited, but is preferably in the range of 2 to 20.

[0146] An alkylthio group is an alkoxy group in which the oxygen atom of the ether bond is replaced with a sulfur atom. The alkylthio group may or may not have a substituent. The number of carbon atoms in the alkylthio group is not particularly limited, but is preferably in the range of 1 to 20.

[0147] The aryl ether group refers to a functional group in which an aromatic hydrocarbon group is bonded via an ether bond, such as a phenoxy group, and may or may not have a substituent. The number of carbon atoms in the aryl ether group is not particularly limited, but is preferably in the range of 6 to 40.

[0148] The aryl thioether group refers to a functional group in which the oxygen atom of the ether bond of an aryl ether group is substituted with a sulfur atom, and may or may not have a substituent. The number of carbon atoms in the aryl thioether group is not particularly limited, but is preferably in the range of 6 to 40.

[0149] Halogen refers to fluorine, chlorine, bromine or iodine.

[0150] The acyl group refers to a functional group in which an alkyl group, a cycloalkyl group, an alkenyl group, an alkynyl group, an aryl group, or a heteroaryl group is bonded via a carbonyl group, such as an acetyl group, a propionyl group, a benzoyl group, or an acrylyl group, and may or may not have a substituent. The number of carbon atoms in the acyl group is not particularly limited, but is preferably 2 to 40, more preferably 2 to 30.

[0151] The ester group refers to a functional group in which, for example, an alkyl group, a cycloalkyl group, an aryl group, a heteroaryl group, or the like is bonded via an ester bond, and may or may not have a substituent. The number of carbon atoms in the ester group is not particularly limited, but is preferably in the range of 1 to 20. More specific examples include a methoxycarbonyl group, an ethoxycarbonyl group, a propoxycarbonyl group, a butoxycarbonyl group, an isopropoxymethoxycarbonyl group, a hexyloxycarbonyl group, and a phenoxycarbonyl group.

[0152] The amide group refers to a functional group in which, for example, an alkyl group, a cycloalkyl group, an aryl group, a heteroaryl group, or the like is bonded via an amide bond, and may or may not have a substituent. The number of carbon atoms in the amide group is not particularly limited, but is preferably in the range of 1 to 20. More specific examples include a methylamide group, an ethylamide group, a propylamide group, a butylamide group, an isopropylamide group, a hexylamide group, and a phenylamide group.

[0153] The sulfonyl group is, for example, an alkyl group, a cycloalkyl group, an aryl group, a heteroaryl group, etc., which is —S(═O) ２ The sulfonyl group represents a functional group bonded via a - bond, and may or may not have a substituent. The number of carbon atoms in the sulfonyl group is not particularly limited, but is preferably in the range of 1 to 20.

[0154] The sulfonate ester group refers to a functional group in which, for example, an alkyl group, a cycloalkyl group, an aryl group, a heteroaryl group, or the like is bonded via a sulfonate ester bond, and may or may not have a substituent. Here, the sulfonate ester bond refers to a group in which the carbonyl part of the ester bond, i.e., —C(═O)—, is bonded to the sulfonyl part, i.e., —S(═O) ２ The number of carbon atoms in the sulfonate ester group is not particularly limited, but is preferably in the range of 1 to 20.

[0155] The sulfonamide group refers to a functional group in which, for example, an alkyl group, a cycloalkyl group, an aryl group, a heteroaryl group, or the like is bonded via a sulfonamide bond, and may or may not have a substituent. Here, the sulfonamide bond refers to a group in which the carbonyl part of the amide bond, i.e., —C(═O)—, is bonded to the sulfonyl part, i.e., —S(═O) ２ The number of carbon atoms in the sulfonamide group is not particularly limited, but is preferably in the range of 1 to 20.

[0156] The amino group may or may not have a substituent. The number of carbon atoms in the amino group is not particularly limited, but is preferably in the range of 2 to 50, more preferably 6 to 40, and particularly preferably 6 to 30.

[0157] The silyl group refers to a functional group to which a substituted or unsubstituted silicon atom is bonded, and examples thereof include alkylsilyl groups such as trimethylsilyl, triethylsilyl, tert-butyldimethylsilyl, propyldimethylsilyl, and vinyldimethylsilyl, and arylsilyl groups such as phenyldimethylsilyl, tert-butyldiphenylsilyl, triphenylsilyl, and trinaphthylsilyl. The silyl group may or may not have a substituent. The number of carbon atoms in the silyl group is not particularly limited, but is preferably in the range of 1 to 30.

[0158] The siloxanyl group refers to a silicon compound group bonded via an ether bond, such as a trimethylsiloxanyl group, etc. The siloxanyl group may or may not have a substituent.

[0159] The boryl group may or may not have a substituent.

[0160] Examples of the compound represented by general formula (3) include the following.

[0161]

[0162] In the organic EL device of the present invention, the light-emitting layer preferably contains a triplet light-emitting material.

[0163] The compound used as a dopant material when the light-emitting layer emits triplet light (phosphorescence) is preferably a metal complex compound containing at least one metal selected from the group consisting of iridium (Ir), ruthenium (Ru), palladium (Pd), platinum (Pt), osmium (Os), and rhenium (Re).

[0164] The ligand of this metal complex compound preferably has a nitrogen-containing aromatic heterocycle such as a phenylpyridine skeleton, a phenylquinoline skeleton, or a carbene skeleton, but is not limited thereto, and an appropriate complex is selected based on the required emission color, device performance, and relationship with the host compound.

[0165] Specific examples of the metal complex compound include tris(2-phenylpyridyl)iridium complex, tris{2-(2-thiophenyl)pyridyl}iridium complex, tris{2-(2-benzothiophenyl)pyridyl}iridium complex, tris(2-phenylbenzothiazole)iridium complex, tris(2-phenylbenzoxazole)iridium complex, trisbenzoquinolineiridium complex, bis(2-phenylpyridyl)(acetylacetonate)iridium complex, bis{2-(2-thiophenyl)pyridyl}iridium complex, bis{2-(2-benzothiophenyl)pyridyl}(acetylacetonate)iridium complex, bis(2-phenylbenzothiazole)(acetylacetonate)iridium complex, Examples of suitable dopants include bis(2-phenylbenzoxazole)(acetylacetonate)iridium complex, bisbenzoquinoline(acetylacetonate)iridium complex, bis{2-(2,4-difluorophenyl)pyridyl}(acetylacetonate)iridium complex, tetraethylporphyrin platinum complex, {tris(cenoyltrifluoroacetone)mono(1,10-phenanthroline)}europium complex, {tris(cenoyltrifluoroacetone)mono(4,7-diphenyl-1,10-phenanthroline)}europium complex, {tris(1,3-diphenyl-1,3-propanedione)mono(1,10-phenanthroline)}europium complex, and trisacetylacetone terbium complex. Phosphorescent dopants such as those described in JP-A-2009-130141 are also suitable. Iridium complexes or platinum complexes are preferred, as they can further improve luminous efficiency.

[0166] The triplet light-emitting materials used as dopant materials may each be contained alone in the light-emitting layer, or two or more of them may be mixed together. When two or more triplet light-emitting materials are contained, the total weight of the dopant materials is preferably 30% by weight or less, more preferably 20% by weight or less, based on the host material.

[0167] The compound used as a preferred dopant material in the triplet light-emitting system is not particularly limited, but specific examples include the following.

[0168]

[0169] Furthermore, the compound used as a preferred host material in a triplet light-emitting system is not particularly limited, but specific examples include the following.

[0170]

[0171] It is also preferable that the light-emitting layer contains a thermally activated delayed fluorescent material. Thermally activated delayed fluorescence is discussed on pages 87 to 103 of "State-of-the-art Organic EL" (edited by Adachi Chinaya and Fujimoto Hiroshi, published by CMC Publishing). This document explains that by bringing the energy levels of the excited singlet state and the excited triplet state of a fluorescent material close to each other, reverse energy transfer from the excited triplet state, which normally has a low transition probability, to the excited singlet state occurs with high efficiency, resulting in the expression of thermally activated delayed fluorescence (TADF). Furthermore, Figure 5 in this document explains the mechanism by which delayed fluorescence occurs. The emission of delayed fluorescence can be confirmed by transient PL (Photo Luminescence) measurement.

[0172] Thermally activated delayed fluorescent materials are also commonly referred to as TADF materials. Thermally activated delayed fluorescent materials may exhibit thermally activated delayed fluorescence using a single compound, or may exhibit thermally activated delayed fluorescence by using multiple compounds in combination. When a material is composed of multiple compounds, a mixture containing multiple compounds may be used as the thermally activated delayed fluorescent material, or layers containing each material may be stacked and used. Known compounds can be used as thermally activated delayed fluorescent materials. Examples include, but are not limited to, benzonitrile derivatives, triazine derivatives, disulfoxide derivatives, carbazole derivatives, indolocarbazole derivatives, dihydrophenazine derivatives, thiazole derivatives, and oxadiazole derivatives.

[0173] It is preferable that a device containing a TADF material in its light-emitting layer further contains a dopant material used for singlet emission in the light-emitting layer, because the TADF material converts triplet excitons into singlet excitons, and the dopant material used for singlet emission accepts the singlet excitons, thereby achieving higher luminous efficiency and longer durability.

[0174] (Electron Transport Layer) In the present invention, the electron transport layer is a layer into which electrons are injected from the cathode and which further transports the electrons. It is desirable for the electron transport layer to have high electron injection efficiency and efficiently transport the injected electrons. Therefore, it is preferable that the material constituting the electron transport layer has high electron affinity, high electron mobility, excellent stability, and is unlikely to generate impurities that trap during production and use. In particular, when a thick film is laminated, low-molecular-weight compounds are prone to deterioration of film quality due to crystallization, so compounds with a molecular weight of 400 or more are preferred to maintain stable film quality. However, considering the balance between hole and electron transport, if the electron transport layer primarily serves to efficiently prevent holes from flowing from the anode to the cathode without recombining, even if the electron transport layer is composed of a material with a relatively low electron transport capacity, the effect of improving luminous efficiency will be equivalent to that of a material with a high electron transport capacity. Therefore, the electron transport layer in the present invention also includes a hole blocking layer that can efficiently block the movement of holes. The electron transport layer may be composed of a single material or a laminate of multiple materials.

[0175] The electron transport material used in the electron transport layer can be any known compound. Examples include condensed polycyclic aromatic derivatives, styryl aromatic ring derivatives, quinone derivatives, phosphorus oxide derivatives, quinolinol complexes, benzoquinolinol complexes, hydroxyazole complexes, azomethine complexes, tropolone metal complexes, and various metal complexes such as flavonol metal complexes. Compounds containing an electron-accepting nitrogen atom and an element selected from carbon, hydrogen, nitrogen, oxygen, silicon, and phosphorus are preferred because they can reduce the driving voltage and achieve more efficient light emission.

[0176] The electron-accepting nitrogen referred to here refers to a nitrogen atom that forms a multiple bond with an adjacent atom. Because the nitrogen atom has high electronegativity, the multiple bond has electron-accepting properties. Therefore, aromatic heterocycles containing electron-accepting nitrogen have high electron affinity. Electron-transporting materials containing electron-accepting nitrogen readily accept electrons from a cathode with high electron affinity, enabling operation at lower voltages. Furthermore, the supply of electrons to the light-emitting layer increases, increasing the recombination probability, further improving luminous efficiency.

[0177] Examples of heteroaryl rings containing an electron-accepting nitrogen include a triazine ring, a pyridine ring, a pyrazine ring, a pyrimidine ring, a quinoline ring, a quinoxaline ring, a quinazoline ring, a naphthyridine ring, a pyrimidopyrimidine ring, a benzoquinoline ring, a phenanthroline ring, an imidazole ring, an oxazole ring, an oxadiazole ring, a triazole ring, a thiazole ring, a thiadiazole ring, a benzoxazole ring, a benzothiazole ring, a benzimidazole ring, and a phenanthroimidazole ring.

[0178] Examples of compounds having these heteroaryl ring structures include pyridine derivatives, bipyridine derivatives, terpyridine derivatives, triazine derivatives, quinazoline derivatives, pyrimidine derivatives, benzimidazole derivatives, benzoxazole derivatives, benzthiazole derivatives, oxadiazole derivatives, thiadiazole derivatives, triazole derivatives, pyrazine derivatives, phenanthroline derivatives, quinoxaline derivatives, quinoline derivatives, benzoquinoline derivatives, oligopyridine derivatives, quinoxaline derivatives, and naphthyridine derivatives. Among these, benzimidazole derivatives, oxadiazole derivatives, triazole derivatives, phenanthroline derivatives, benzoquinoline derivatives, bipyridine derivatives, terpyridine derivatives, and naphthyridine derivatives are preferably used from the viewpoint of electron transport ability.

[0179] Furthermore, when these derivatives have a condensed polycyclic aromatic skeleton, the glass transition temperature is improved, the electron mobility is increased, and the driving voltage of the organic EL device can be further reduced, which is preferable. Furthermore, in consideration of further improving the durability life of the device, ease of synthesis, and ease of availability of raw materials, it is more preferable that the condensed polycyclic aromatic skeleton is a fluoranthene skeleton, an anthracene skeleton, a pyrene skeleton, or a phenanthroline skeleton.

[0180] The compound used as a preferred electron transport material is not particularly limited, but specific examples include the following.

[0181]

[0182]

[0183]

[0184] The compounds represented by the general formula (1) or (2) also have high electron transporting properties and are therefore preferred as materials for the electron transport layer.

[0185] The electron transport material may be used alone, or two or more of the electron transport materials may be mixed, or one or more other electron transport materials may be mixed with the electron transport material. The electron transport layer may contain a donor material in addition to the electron transport material, preferably the compound represented by formula (1) or (2). The donor material is a compound that improves the electron injection barrier, thereby facilitating electron injection from the cathode or the electron injection layer into the electron transport layer, and further improving the electrical conductivity of the electron transport layer.

[0186] Preferable examples of substances used as donor materials include alkali metals, complexes of alkali metals and organic substances, and rare earth metals. Preferable examples of alkali metals and rare earth metals include lithium and ytterbium, which have a low work function and are highly effective in improving electron transport ability. In addition, a plurality of these metals may be used, or an alloy made of these metals may be used.

[0187] Furthermore, because deposition in a vacuum is easy and handling is excellent, inorganic salts or complexes with organic substances are preferred over simple metals. Furthermore, complexes with organic substances are more preferred because they facilitate handling in the atmosphere and allow for easy adjustment of the addition concentration. Examples of inorganic salts include oxides, nitrides, fluorides, and carbonates. Preferable examples of alkali metals or alkaline earth metals include lithium and cesium, from the viewpoint of further reducing the driving voltage. Preferable examples of organic substances in complexes with organic substances include quinolinol, benzoquinolinol, pyridylphenol, flavonol, hydroxyimidazopyridine, hydroxybenzazole, and hydroxytriazole. Among these, complexes of alkali metals and organic substances are preferred from the viewpoint of further reducing the driving voltage of organic EL devices. Furthermore, complexes of lithium and organic substances are more preferred from the viewpoints of ease of synthesis and thermal stability, and lithium quinolinol (Liq), which is relatively inexpensive and available, is particularly preferred.

[0188] The ionization potential of the electron transport layer is not particularly limited, but is preferably from 5.6 eV to 8.0 eV, more preferably from 5.6 eV to 7.0 eV.

[0189] (Electron Injection Layer) In the present invention, an electron injection layer may be disposed between the cathode and the electron transport layer. Generally, the electron injection layer is disposed for the purpose of assisting the injection of electrons from the cathode to the electron transport layer. When an electron injection layer is disposed, a layer containing a compound having a heteroaryl ring structure containing electron-accepting nitrogen may be used, or a layer containing the above-mentioned donor material may be used.

[0190] Furthermore, inorganic insulating or semiconducting materials can be used for the electron injection layer, and known materials can be used. By using these materials, it is possible to suppress short circuits in the organic EL element and improve the electron injection properties.

[0191] Such an insulator is preferably at least one metal compound selected from the group consisting of alkali metal chalcogenides, alkaline earth metal chalcogenides, alkali metal halides, and alkaline earth metal halides.

[0192] Furthermore, a complex of an organic substance and a metal can also be suitably used. When a complex of an organic substance and a metal is used in the electron injection layer, the film thickness can be easily adjusted. Preferred examples of the organic substance in the organometallic complex include quinolinol, benzoquinolinol, pyridylphenol, flavonol, hydroxyimidazopyridine, hydroxybenzazole, and hydroxytriazole.

[0193] Furthermore, a layer containing a compound represented by general formula (1) or (2) also has high electron injecting properties and is therefore preferred as an electron injecting layer.

[0194] In addition to the compound represented by general formula (1) or (2), the electron injection layer preferably further contains an alkali metal or a rare earth metal, from the viewpoint of further reducing the driving voltage and further improving the durability life. Preferred examples of the alkali metal and rare earth metal include alkali metals such as lithium, sodium, potassium, rubidium, and cesium, which have a low work function and are highly effective in improving electron transport ability, and rare earth metals such as samarium, europium, and ytterbium. Furthermore, more preferred examples of the alkali metal and rare earth metal include lithium and ytterbium, from the viewpoint of further reducing the driving voltage.

[0195] (Charge Generation Layer) The charge generation layer generally consists of a double layer, specifically a pn junction charge generation layer consisting of an n-type charge generation layer and a p-type charge generation layer. When a voltage is applied to the organic EL element, the pn junction charge generation layer generates charges or separates the charges into holes and electrons, and injects these holes and electrons into the light-emitting layer via the hole transport layer and electron transport layer. Specifically, it functions as an intermediate charge generation layer in an organic EL element in which multiple light-emitting layers are stacked at a distance from each other. The n-type charge generation layer supplies electrons to the first light-emitting layer located on the anode side, and the p-type charge generation layer supplies holes to the second light-emitting layer located on the cathode side. Therefore, the luminous efficiency of an organic EL element in which multiple light-emitting layers are stacked at a distance from each other can be further improved, the driving voltage can be reduced, and the durability of the element can be further improved.

[0196] The n-type charge generation layer comprises an n-type dopant and a host, and conventional materials can be used for these. For example, an alkali metal, alkaline earth metal, rare earth metal, or a simple substance of a Group 11 element can be used as the n-type dopant. Furthermore, a compound having a nitrogen-containing aromatic heterocycle, such as a phenanthroline derivative or an oligopyridine derivative, can be used as the host. In particular, the compounds represented by general formula (1) or general formula (2) and phenanthroline derivatives are preferred because they exhibit excellent properties as hosts for the n-type charge generation layer.

[0197] In one embodiment of the charge generating layer, it is preferable to further contain a phenanthroline derivative in addition to the compound represented by formula (1) or (2). Examples of the phenanthroline derivative include the following compounds.

[0198]

[0199]

[0200] In one embodiment of the charge generating layer, it is preferable that the charge generating layer further contains an alkali metal or a rare earth metal in addition to the compound represented by general formula (1) or general formula (2). As the alkali metal, Li is particularly preferable. As the rare earth metal, Yb is particularly preferable.

[0201] As one embodiment of the charge generating layer, a structure containing a phenanthroline derivative and an alkali metal or a rare earth metal in addition to the compound represented by formula (1) or (2) is also preferred.

[0202] The p-type charge generating layer is composed of a p-type dopant and a host, and conventional materials can be used for these. For example, the p-type dopant can be tetrafluorene-7,7,8,8-tetracyanoquinodimethane (F4-TCNQ), a tetracyanoquinodimethane derivative, a radialene derivative, iodine, or FeCl. ３ , FeF ３ , SbCL ５ The p-type dopant is preferably a radialene derivative, and the host is preferably an arylamine derivative.

[0203] The thickness of the organic layer is not limited because it depends on the resistance value of the light-emitting substance, but is preferably 1 to 1,000 nm. The thickness of each of the light-emitting layer, electron transport layer, and hole transport layer is preferably 1 nm to 200 nm, more preferably 5 nm to 100 nm.

[0204] The method for forming each of the layers constituting the organic EL element is not particularly limited, and may be resistance heating evaporation, electron beam evaporation, sputtering, molecular lamination, coating, or the like. However, resistance heating evaporation or electron beam evaporation is usually preferred in terms of element characteristics.

[0205] The organic EL element according to the embodiment of the present invention has a function of converting electrical energy into light. While direct current is primarily used as the electrical energy, pulsed current or alternating current can also be used. While there are no particular limitations on the current and voltage values, they should be selected so as to obtain maximum brightness with as little energy as possible, taking into consideration the power consumption and lifespan of the element.

[0206] The organic EL element according to the embodiment of the present invention is suitably used as a display device such as a matrix and / or segment display.

[0207] The organic EL element according to the embodiment of the present invention is also preferably used as a backlight for various devices. Backlights are primarily used for the purpose of improving the visibility of display devices such as non-self-luminous displays, and are used in liquid crystal displays, clocks, audio equipment, automobile panels, display boards, signs, etc. In particular, the organic EL element of the present invention is preferably used as a backlight for liquid crystal displays, particularly for personal computers, which are being considered for thinning, and can provide a backlight that is thinner and lighter than conventional ones.

[0208] The organic EL element according to the embodiment of the present invention is also preferably used in various lighting devices. The organic EL element according to the embodiment of the present invention can achieve both high luminous efficiency and high color purity, and can also be made thin and lightweight, thereby realizing a lighting device that combines low power consumption, vivid luminous color, and high designability.

[0209] The present invention will be described below with reference to examples, but the present invention is not limited to these examples.

[0210] Synthesis Example 1: Synthesis of Compound 9 A mixed solution of 4.11 g of 2-(3-bromophenyl)-9-phenyl-1,10-phenanthroline, 3.73 g of boronic acid ester A, 702 mg of dichlorobis(triphenylphosphinepalladium) dichloride, 200 mL of 2.0 M aqueous potassium phosphate solution, and 500 mL of dimethoxyethane was heated and stirred under reflux for 2 hours under a nitrogen stream. After cooling to room temperature, water was added, the mixture was filtered, washed with methanol, and dried under vacuum. The catalyst was removed from the resulting solid using activated carbon, and the solvent was removed by evaporation. The resulting solid was recrystallized from toluene and then dried under vacuum to obtain 3.5 g of Compound 9.

[0211] The resulting compound was subjected to 1×10 －３ Sublimation purification was carried out at about 320° C. under a pressure of 100 Pa. The HPLC purity (area % at a measurement wavelength of 254 nm) of Compound 9 before and after sublimation purification was 99.9%.

[0212] After sublimation purification, mass spectrometry (MS) analysis and １The structure of Compound 9 was identified by H-NMR analysis. The analytical results are shown below. MS (m / z): 578 [M+H] ＋ １ H-NMR (400MHz, DMSO-d6) δ: 8.71 (d, 2H), 8.33 (d, 2H), 8.32 (d, 1H), 8.31 (s, 1H), 8.2 (d, 1H), 8.04 (d, 2H), 7.9 (d, 1H), 7.73 ( t, 1H), 7.61 (d, 1H), 7.56 (d, 2H), 7.55 (t, 2H), 7.54 (d, 2H), 7.49 (t, 1H), 7.37 (d, 2H), 7.29 (d, 2H), 6.73 (t, 2H), 6.63 (d, 2H)

[0213]

[0214] Synthesis Example 2: Synthesis of Compound 13 A mixed solution of 4.11 g of 2-(3-bromophenyl)-9-phenyl-1,10-phenanthroline, 3.70 g of boronic acid ester B, 702 mg of dichlorobis(triphenylphosphinepalladium) dichloride, 200 mL of 2.0 M aqueous potassium phosphate solution, and 500 mL of dimethoxyethane was heated and stirred under reflux for 3 hours under a nitrogen stream. After cooling to room temperature, water was added, the mixture was filtered, washed with hexane, and dried under vacuum. The catalyst was removed from the resulting solid using activated carbon, and the solvent was removed by evaporation. The resulting solid was recrystallized from toluene and then dried under vacuum to obtain 3.8 g of Compound 13.

[0215] The obtained compound 13 was subjected to a 1×10 －３ Sublimation purification was carried out at about 320° C. under a pressure of 100 Pa. The HPLC purity (area % at a measurement wavelength of 254 nm) of Compound 13 before and after sublimation purification was 99.9%.

[0216] After sublimation purification, mass spectrometry (MS) analysis and １ The structure of Compound 13 was identified by H-NMR analysis. The analytical results are shown below. MS (m / z): 575 [M+H] ＋ １H-NMR (400MHz, DMSO-d6) δ: 8.71 (d, 2H), 8.69 (d, 2H), 8.65 (d, 1H), 8.55 (d, 1H), 8.33 (d, 2H), 8.2 (d, 1H), 8.15 (t, 1H), 8.02 (d, 1H), 7.99 (d, 1H) , 7.94 (d, 1H), 7.9 (d, 1H), 7.89 (s, 1H), 7.85 (d, 2H), 7.77 (d, 1H), 7.55 ( d, 2H), 7.49 (t, 1H), 7.36 (t, 1H), 7.35 (t, 1H), 7.29 (d, 2H), 7.16 (t, 1H)

[0217]

[0218] Next, the evaluation method for each example will be described. Each evaluation was performed with n=1.

[0219] (Driving voltage) The organic EL elements obtained in Examples 1 to 48 and Comparative Examples 1 to 6 were each driven at a luminance of 1000 cd / m ２ The device was then turned on at a current density of 10 mA / cm at room temperature, and the initial driving voltage was measured. ２ The voltage was measured after driving the device at a constant current of 100 hours at 100 volts, and the amount of voltage increase from the initial driving voltage was calculated.

[0220] The organic EL devices obtained in Examples 49 to 196 and Comparative Examples 7 to 24 were each subjected to a current density of 10 mA / cm ２ The device was driven at 1000 V and the initial driving voltage was measured.

[0221] The smaller the initial driving voltage, the lower the driving voltage, and therefore the better the light emitting efficiency (brightness / power). Also, the smaller the voltage rise, the better the durability.

[0222] (External Quantum Efficiency) The organic EL devices obtained in Examples 1 to 48 and Comparative Examples 1 to 6 were each subjected to a current density of 10 mA / cm ２ The external quantum efficiency was measured and the luminous efficiency was evaluated. The higher the external quantum efficiency, the better the luminous efficiency can be evaluated.

[0223] (Brightness) The organic EL devices obtained in Examples 49 to 196 and Comparative Examples 7 to 24 were each subjected to a current density of 10 mA / cm ２The luminance was measured and the luminous efficiency was evaluated. The higher the luminance, the better the luminous efficiency.

[0224] (Durability) The organic EL devices obtained in Examples 1 to 196 and Comparative Examples 1 to 24 were each subjected to a current density of 10 mA / cm ２ The time required for the brightness to decrease by 20% from the initial brightness was measured and used as the durability.

[0225] Example 1 A glass substrate (manufactured by Geomatec Co., Ltd., 11 Ω / □, sputtered product) on which a 165 nm ITO transparent conductive film had been deposited as an anode was cut into 38 mm x 46 mm and etched. The obtained substrate was ultrasonically cleaned for 15 minutes using "Semicoclean" 56 (trade name, manufactured by Furuuchi Chemical Co., Ltd.) and then washed with ultrapure water. This substrate was subjected to UV-ozone treatment for 1 hour immediately before fabricating the element, and then placed in a vacuum deposition apparatus, and the degree of vacuum in the apparatus was adjusted to 5 x 10. －４ The chamber was evacuated to a pressure of 100 Pa or less. Using a resistance heating method, first, P-D1 was vapor-deposited to a thickness of 5 nm as a hole injection layer, and then HT-1 was vapor-deposited to a thickness of 50 nm as a hole transport layer. Next, a mixed layer of host material H-1 and dopant material D-1 was vapor-deposited to a thickness of 20 nm as an emitting layer so that the doping concentration was 5 wt %. Next, ET-1 and 2E-1 were vapor-deposited to a thickness of 35 nm as an electron transport layer, with the vapor deposition rate ratio of ET-1 to 2E-1 = 1:1. Next, compound 1 and the metal element Li as a dopant were vapor-deposited to a thickness of 10 nm as an electron injection layer, with the vapor deposition rate ratio of compound 1:Li = 99:1. Subsequently, aluminum was vapor-deposited to a thickness of 60 nm to form a cathode, and a 5 mm x 5 mm square organic EL device was fabricated.

[0226] When this organic EL device was evaluated by the above-mentioned method, the initial driving voltage was 3.80 V, the external quantum efficiency (luminous efficiency) was 5.40%, the durability life was 1130 hours, and the voltage increase after driving for 100 hours at room temperature was 0.042 V. Compounds 1, P-D1, HT-1, H-1, D-1, ET-1, and 2E-1 are the compounds shown below.

[0227]

[0228] Examples 2 to 48, Comparative Examples 1 to 6 Devices were fabricated in the same manner as in Example 1, except that the compounds used were changed as shown in Table 1. The results of each example and comparative example are shown in Table 1. Compounds 2 to 54 are the compounds shown below.

[0229]

[0230]

[0231]

[0232]

[0233]

[0234]

[0235]

[0236]

[0237] Example 49 A glass substrate (manufactured by Geomatec Co., Ltd., 11 Ω / □, sputtered product) on which a 165 nm ITO transparent conductive film had been deposited as an anode was cut into 38 mm × 46 mm pieces and etched. The resulting substrate was ultrasonically cleaned for 15 minutes using "Semicoclean" 56 (trade name, manufactured by Furuuchi Chemical Co., Ltd.) and then washed with ultrapure water. This substrate was subjected to UV-ozone treatment for 1 hour immediately before fabricating the element, and then placed in a vacuum deposition apparatus, and the degree of vacuum in the apparatus was adjusted to 5 × 10. －４ The chamber was evacuated to a pressure of 100 Pa or less. First, P-D1 was vapor-deposited to a thickness of 5 nm as a hole injection layer by resistance heating. Next, an emitting unit (first emitting unit) consisting of a hole transport layer, an emitting layer, and an electron transport layer was formed on the hole injection layer.

[0238] Specifically, HT-1 was deposited to a thickness of 50 nm as a hole transport layer, and then a mixed layer of host material H-1 and dopant material D-1 was deposited to a thickness of 20 nm as an emitting layer so that the doping concentration was 5 wt %. Next, ET-1 and 2E-1 were deposited to a thickness of 35 nm as an electron transport layer so that the deposition rate ratio of ET-1 to 2E-1 was 1:1.

[0239] On the first light-emitting unit, Compound 1 and a metal element Yb as a dopant were deposited to a thickness of 10 nm as an n-type charge generation layer so that the deposition rate ratio of Compound 1:Yb was 98:2, and then P-D1 was deposited to a thickness of 10 nm as a p-type charge generation layer.

[0240] Following the charge generation layer, a second light-emitting unit was formed in the same manner as the first light-emitting unit. Then, as an electron injection layer, Compound 1 and a metal element Yb serving as a dopant were vapor-deposited to a thickness of 10 nm at a vapor deposition rate ratio of Compound 1:Yb=98:2, and subsequently, aluminum was vapor-deposited to a thickness of 60 nm to form a cathode, thereby producing an organic EL device having a size of 5 mm × 5 mm.

[0241] When this organic EL element was evaluated by the above-mentioned method, the initial driving voltage was 7.93 V and the luminance was 1786 cd / m ２ The durability was 2207 hours.

[0242] Examples 50 to 148 and Comparative Examples 6 to 18 Organic EL devices were prepared in the same manner as in Example 49, except that the compounds, dopant materials, metal elements, and vapor deposition rate ratios of the compounds and metal elements used were changed as shown in Tables 2 and 3. In Example 97, Compound 1, ET-2, and the metal element Yb were vapor-deposited to a thickness of 10 nm to form an n-type charge generation layer, with the vapor deposition rate ratio of Compound 1:ET-2:Yb=49:49:2. In Example 147, Compound 1, ET-2, and the metal element Li were vapor-deposited to a thickness of 10 nm to form an n-type charge generation layer, with the vapor deposition rate ratio of Compound 1:ET-2:Li=49:49:2. In Examples 98 and 148, a mixed layer of host material H-1 and dopant material D-2 was vapor-deposited to a thickness of 20 nm to form an emitting layer, with a doping concentration of 5 wt %. The results of each Example and Comparative Example are shown in Tables 2 and 3. D-2 and ET-2 are the compounds shown below.

[0243]

[0244]

[0245]

[0246] Example 149 An organic EL element was produced in the same manner as in Example 29, except that Compound 1 was used instead of ET-1 in forming the electron transport layer, and that ET-2 was used instead of Compound 1 in forming the n-type charge generation layer. When this organic EL element was evaluated by the above-mentioned method, the initial driving voltage was 7.87 V and the luminance was 1798 cd / m ２ The durability was 2244 hours.

[0247] Examples 150 to 196, Comparative Examples 19 to 24 Organic EL devices were prepared in the same manner as in Example 149, except that the compounds used were changed as shown in Table 4. The results of each of the Examples and Comparative Examples are shown in Table 4.

[0248]

Claims

1. A compound represented by the following general formula (1) or general formula (2): (In general formula (1), Ar １０１ ~Ar １０２ are each independently a substituted or unsubstituted aryl group or a substituted or unsubstituted heteroaryl group, and Ar １０３ is a substituted or unsubstituted arylene group or a substituted or unsubstituted heteroarylene group, and at least one of Ar １０１ ~Ar １０３ is a group containing a nitrogen atom. L １０１ is a single bond, a substituted or unsubstituted phenylene group, a substituted or unsubstituted naphthylene group, a substituted or unsubstituted pyridylene group, a substituted or unsubstituted pyridazylene group, a substituted or unsubstituted pyrazylene group, a substituted or unsubstituted pyrimidylene group, or a substituted or unsubstituted triazylene group. R １０１ ~R １０７ are each independently selected from the group consisting of a hydrogen atom, an alkyl group, an alkoxy group, a phosphoryl group, a halogen atom, a cyano group, a substituted or unsubstituted aryl group, and a substituted or unsubstituted heteroaryl group.) (In general formula (2), Ar ２０１ ~Ar ２０２ are each independently a substituted or unsubstituted aryl group or an unsubstituted heteroaryl group having 10 or fewer carbon atoms, and Ar ２０３ is a substituted or unsubstituted arylene group or an unsubstituted heteroarylene group having 10 or fewer carbon atoms, and at least one of Ar ２０１ ~Ar ２０３ is a group containing a nitrogen atom in the ring. Also, at least one set of the pairs of Ar ２０１ and Ar ２０２ , Ar ２０２ and Ar ２０３ , Ar ２０１ and Ar ２０３ are linked to each other to form a ring structure. L ２０１ is a single bond, a substituted or unsubstituted phenylene group, a substituted or unsubstituted naphthylene group, a substituted or unsubstituted pyridylene group, a substituted or unsubstituted pyridazylene group, a substituted or unsubstituted pyrazylene group, a substituted or unsubstituted pyrimidylene group or a substituted or unsubstituted triazylene group. R ２０１ is an unsubstituted aryl group or an unsubstituted heteroaryl group, R ２０２ to R ２０７ are each independently selected from the group consisting of a hydrogen atom, an alkyl group, an alkoxy group, a phosphoryl group, a halogen atom, a cyano group, a substituted or unsubstituted aryl group and a substituted or unsubstituted heteroaryl group.) 2. Ar in the general formula (1) １０１ ~Ar １０２ and Ar in the general formula (2) ２０１ ~Ar ２０２ are each independently selected from the group consisting of a substituted or unsubstituted phenyl group, a substituted or unsubstituted naphthyl group, a substituted or unsubstituted anthryl group, a substituted or unsubstituted phenanthrenyl group, a substituted or unsubstituted pyrenyl group, a substituted or unsubstituted pyridyl group, a substituted or unsubstituted pyrimidyl group, and a substituted or unsubstituted quinoxalinyl group, and Ar in the general formula (1) １０３ and Ar in the general formula (2) ２０３ is selected from the group consisting of a substituted or unsubstituted phenylene group, a substituted or unsubstituted naphthylene group, a substituted or unsubstituted anthrylene group, a substituted or unsubstituted phenanthrenylene group, a substituted or unsubstituted pyrenylene group, a substituted or unsubstituted pyridylene group, a substituted or unsubstituted pyrimidylene group, and a substituted or unsubstituted quinoxalinylene group. The compound according to claim 1.

3. L in the general formula (1) １０１ and L in the general formula (2) ２０１ is a single bond, an unsubstituted phenylene group, an unsubstituted naphthylene group, an unsubstituted pyridylene group, an unsubstituted pyridazylene group, an unsubstituted pyrazylene group, an unsubstituted pyrimidine group or an unsubstituted triazylene group, and the compound according to claim 1.

4. R in the general formula (1) １０２ ~R １０７ and R in the general formula (2) ２０２ ~R ２０７ are hydrogen atoms, the compound according to claim 1.

5. Ar in the general formula (1) １０１ ~Ar １０２ At least one of, and Ar in the general formula (2) ２０１ ~Ar ２０２ The compound according to claim 1, wherein at least one of each is independently an aryl group substituted with a group containing a nitrogen atom.

6. An organic EL element that has at least an electron transport layer and a light-emitting layer between an anode and a cathode and emits light by electric energy, wherein the electron transport layer contains the compound according to claim 1.

7. The organic EL element according to claim 6, wherein the electron transport layer further contains an alkali metal, a rare earth metal, or a complex of an alkali metal and an organic substance.

8. An organic EL element that has at least a charge generation layer and a light-emitting layer between an anode and a cathode and emits light by electric energy, wherein the charge generation layer contains the compound according to claim 1.

9. The organic EL element according to claim 8, wherein the charge generation layer further contains a phenanthroline derivative.

10. The organic EL element according to claim 8, wherein the charge generation layer further contains an alkali metal or a rare earth metal.

11. The organic EL element according to claim 10, wherein the charge generation layer further contains an alkali metal, and the alkali metal is Li.

12. The organic EL element according to claim 10, wherein the charge generation layer further contains a rare earth metal, and the rare earth metal is Yb.

13. An organic EL element that has at least an electron injection layer and a light-emitting layer between an anode and a cathode and emits light by electric energy, wherein the electron injection layer contains the compound according to claim 1.

14. The organic EL element according to claim 13, wherein the electron injection layer further contains an alkali metal or a rare earth metal.

15. The organic EL element according to claim 6, wherein the light-emitting layer contains a compound represented by the following general formula (3). (In general formula (3), the Za ring, the Zb ring, and the Zc ring are each independently a substituted or unsubstituted aryl ring having 6 to 30 ring-forming carbon atoms or a substituted or unsubstituted heteroaryl ring having 5 to 30 ring-forming atoms; Z １ and Z ２ are each independently an oxygen atom, NR a (a nitrogen atom having a substituent Ra), or a sulfur atom. When Z １ is NR a, the substituent Ra may or may not be bonded to the Za ring or the Zb ring to form a ring. When Z ２ is NR a, the substituent Ra may or may not be bonded to the Zb ring or the Zc ring to form a ring; Ra is each independently a substituted or unsubstituted aryl group having 6 to 30 ring-forming carbon atoms, a substituted or unsubstituted heteroaryl group having 5 to 30 ring-forming atoms, or a substituted or unsubstituted alkyl group having 1 to 30 carbon atoms; Y is a boron atom, a phosphorus atom, SiR b (a silicon atom having a substituent Rb), P=O, or P=S; Rb is each independently a substituted or unsubstituted aryl group having 6 to 30 ring-forming carbon atoms, a substituted or unsubstituted heteroaryl group having 5 to 30 ring-forming atoms, or a substituted or unsubstituted alkyl group having 1 to 30 carbon atoms.) 16. A display device including the organic EL element according to claim 6.

17. A lighting device including the organic EL element according to claim 6.

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