JP2014138006A - Light-emitting element material and light-emitting element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an organic thin film light-emitting element improving all of light emission efficiency, driving voltage and durable life.SOLUTION: A light-emitting element material is characterized in containing a compound having an aromatic hydrocarbon group formed by the condensation of at least three rings, a coupling group and a dibenzothiophene dioxide group.

Description

  The present invention relates to a light emitting element capable of converting electric energy into light and a material used therefor. The present invention can be used in fields such as display elements, flat panel displays, backlights, lighting, interiors, signs, signboards, electrophotographic machines, and optical signal generators.

  In recent years, research on organic thin-film light emitting devices that emit light when electrons injected from a cathode and holes injected from an anode are recombined in an organic phosphor sandwiched between both electrodes has been actively conducted. This light emitting element is characterized by thin light emission with high luminance under a low driving voltage and multicolor light emission by selecting a fluorescent material.

  This study was conducted by C.D. W. Since Tang et al. Showed that organic thin film devices emit light with high brightness, many practical studies have been made, and organic thin film light emitting devices have been steadily put into practical use, such as being used in mobile phone main displays. Is progressing. However, there are still many technical issues, and in particular, achieving both high-efficiency light emission and long life is one of the major issues. In particular, for blue light-emitting elements, no effective solution for achieving both high-efficiency light emission and long life has been found.

  Under such circumstances, thiophene dioxide derivatives are attracting attention from the viewpoints of electron affinity, high fluorescence quantum yield, and ease of multicolor light emission. Among them, a technique using dibenzothiophene dioxide derivatives has been disclosed. (For example, refer to Patent Documents 1 and 2).

JP 2001-313174 A JP2012-153628A

  However, with the conventional technology, there is a problem that if the light emission efficiency of the element is improved or the drive voltage is lowered, the durability life is reduced, and there is still a technology for achieving both high light emission efficiency, low drive voltage, and long life. Not found.

  An object of the present invention is to provide an organic thin-film light-emitting element that solves the problems of the prior art and has improved luminous efficiency, driving voltage, and durability.

  The present invention is a light emitting device material containing a compound represented by the following general formula (1).

In the formula, Ar ¹ is an aromatic hydrocarbon group in which three or more rings are condensed, and is selected from groups other than a phenanthryl group, a fluorenyl group, and a triphenylenyl group. L ¹ is a single bond, an arylene group, or a heteroarylene group. Z is a group represented by the following general formula (2). n ¹ is an integer of 1 or more. When n ¹ is 2 or more, L ¹ and Z may be the same or different.

In the formula, R ^{1 to} R ⁸ may be the same or different and are each hydrogen, halogen, alkyl group, cycloalkyl group, heterocyclic group, alkenyl group, cycloalkenyl group, alkynyl group, alkoxy group, alkylthio group, Selected from the condensed ring formed between aryl ether group, aryl thioether group, aryl group, heteroaryl group, cyano group, carbonyl group, carboxyl group, oxycarbonyl group, carbamoyl group, silyl group and adjacent substituents It is. However coupling with ^{L 1} in one position one of ^R 1 to R ^8.

  According to the present invention, it is possible to provide an organic thin film light emitting device that simultaneously satisfies the required characteristics of luminous efficiency, driving voltage, and durability life.

  The compound represented by the general formula (1) will be described in detail.

In the formula, Ar ¹ is an aromatic hydrocarbon group in which three or more rings are condensed, and is selected from groups other than a phenanthryl group, a fluorenyl group, and a triphenylenyl group. L ¹ is a single bond, an arylene group, or a heteroarylene group. Z is a group represented by the following general formula (2). n ¹ is an integer of 1 or more. When n ¹ is 2 or more, L ¹ and Z may be the same or different.

In the formula, R ^{1 to} R ⁸ may be the same or different and are each hydrogen, halogen, alkyl group, cycloalkyl group, heterocyclic group, alkenyl group, cycloalkenyl group, alkynyl group, alkoxy group, alkylthio group, Selected from the condensed ring formed between aryl ether group, aryl thioether group, aryl group, heteroaryl group, cyano group, carbonyl group, carboxyl group, oxycarbonyl group, carbamoyl group, silyl group and adjacent substituents It is. However coupling with ^{L 1} in one position one of ^R 1 to R ^8.

The arylene group refers to a divalent or trivalent group derived from an aromatic hydrocarbon group such as a phenyl group, a naphthyl group, or a biphenyl group, which may or may not have a substituent. Also good. When L ^{1 in the} general formula (1) is an arylene group, the number of nuclear carbon atoms is preferably in the range of 6 to 30. Specific examples of the arylene group include 1,4-phenylene group, 1,3-phenylene group, 1,2-phenylene group, 4,4′-biphenylene group, 4,3′-biphenylene group, 3,3 Examples include '-biphenylene group, 1,4-naphthylene group, 1,5-naphthylene group, 2,5-naphthylene group, 2,6-naphthylene group, 2,7-naphthylene group and the like. More preferred are a 1,4-phenylene group and a 1,3-phenylene group.

  The heteroarylene group is an aromatic group having one or more atoms other than carbon such as pyridyl group, quinolinyl group, pyrimidinyl group, pyrazinyl group, naphthyridyl group, dibenzofuranyl group, dibenzothiophenyl group, carbazolyl group in the ring. A divalent or trivalent group derived from a group is shown, which may or may not have a substituent. Although carbon number of heteroarylene group is not specifically limited, Preferably, it is the range of 2-30.

  The alkyl group is, for example, 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 is a substituent. It may or may not have. There is no restriction | limiting in particular in the additional substituent in the case of being substituted, For example, an alkyl group, an aryl group, heteroaryl group etc. can be mentioned, This point is common also in the following description. The number of carbon atoms of the alkyl group is not particularly limited, but is preferably 1 or more and 20 or less, more preferably 1 or more and 8 or less, from the viewpoint of availability and cost.

  The cycloalkyl group represents, for example, a saturated alicyclic hydrocarbon group such as a cyclopropyl group, a cyclohexyl group, a norbornyl group, an adamantyl group, which may or may not have a substituent. The number of carbon atoms in the alkyl group moiety is not particularly limited, but is preferably in the range of 3 or more and 20 or less.

  The heterocyclic group refers to an aliphatic ring having atoms other than carbon, such as a pyran ring, a piperidine ring, and a cyclic amide, in the ring, which may or may not have a substituent. . Although carbon number of a heterocyclic group is not specifically limited, Preferably it is the range of 2-20.

  An alkenyl group shows the unsaturated aliphatic hydrocarbon group containing double bonds, such as a vinyl group, an allyl group, and a butadienyl group, and this may or may not have a substituent. Although carbon number of an alkenyl group is not specifically limited, Preferably it is the range of 2-20.

  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 have a substituent. You don't have to.

  An alkynyl group shows the unsaturated aliphatic hydrocarbon group containing triple bonds, such as an ethynyl group, for example, and may or may not have a substituent. The number of carbon atoms of the alkynyl group is not particularly limited, but is preferably in the range of 2 or more and 20 or less.

  The alkoxy group refers to, for example, a functional group having an aliphatic hydrocarbon group bonded through an ether bond such as a methoxy group, an ethoxy group, or a propoxy group, and the aliphatic hydrocarbon group may have a substituent. It may not have. Although carbon number of an alkoxy group is not specifically limited, Preferably it is the range of 1-20.

  The alkylthio group is a group in which an oxygen atom of an ether bond of an alkoxy group is substituted with a sulfur atom. The hydrocarbon group of the alkylthio group may or may not have a substituent. Although carbon number of an alkylthio group is not specifically limited, Preferably it is the range of 1-20.

  An aryl ether group refers to a functional group to which an aromatic hydrocarbon group is bonded via an ether bond, such as a phenoxy group, and the aromatic hydrocarbon group may or may not have a substituent. Good. Although carbon number of an aryl ether group is not specifically limited, Preferably, it is the range of 6-40.

  An aryl thioether group is one in which the oxygen atom of the ether bond of the aryl ether group is substituted with a sulfur atom. The aromatic hydrocarbon group in the aryl ether group may or may not have a substituent. Although carbon number of an aryl ether group is not specifically limited, Preferably, it is the range of 6-40.

  The aryl group refers to an aromatic hydrocarbon group such as a phenyl group, a naphthyl group, a biphenyl group, a phenanthryl group, a terphenyl group, a pyrenyl group, or a fluoranthenyl group. The aryl group may or may not have a substituent. Although carbon number of an aryl group is not specifically limited, Preferably, it is the range of 6-40.

  A heteroaryl group is a furanyl group, thiophenyl group, pyridyl group, quinolinyl group, isoquinolinyl group, pyrazinyl group, pyrimidyl group, naphthyridyl group, benzofuranyl group, benzothiophenyl group, indolyl group, dibenzofuranyl group, dibenzothiophenyl group And a cyclic aromatic group having one or more atoms other than carbon in the ring, such as a carbazolyl group, which may be unsubstituted or substituted. Although carbon number of heteroaryl group is not specifically limited, Preferably it is the range of 2-30.

  The carbonyl group, carboxyl group, oxycarbonyl group, carbamoyl group, and silyl group may or may not have a substituent. Here, examples of the substituent include an alkyl group, a cycloalkyl group, an aryl group, and a heteroaryl group, and these substituents may be further substituted. The condensed ring formed between adjacent substituents may be conjugated or non-conjugated, and may be unsubstituted or substituted. Further, it may be condensed with another ring.

  In all of the above groups, hydrogen may be deuterium. Halogen refers to an atom selected from fluorine, chlorine, bromine and iodine.

In one position one of R ¹ to R ⁸ and connects the ^{L 1 refers} to the carbon atoms and ^{L 1} to R 1 to R ⁸ are linked binds directly.
The compound represented by the general formula (1) has a dibenzothiophene dioxide group. The dibenzothiophene dioxide group has a large steric hindrance because two oxygen atoms bonded to a sulfur atom take a three-dimensional structure orthogonal to the thiophene skeleton plane, and suppresses the interaction between molecules. This increases the amorphous nature of the material and the glass transition temperature, so that the stability of the thin film containing the material is improved and the durability life of the light-emitting element is improved. Moreover, since concentration quenching can be prevented by suppressing the interaction between molecules, the dibenzothiophene dioxide group also contributes to the improvement of luminous efficiency. Furthermore, since the dibenzothiophene dioxide group is a strong electron-attracting group, the compound of the general formula (1) is a material having excellent electron affinity, and when used as an electron transporting material or a host material for a light emitting layer, a light emitting device The driving voltage can be lowered. In addition, when used as a dopant material for the light emitting layer, a strong electron trap effect appears and it is possible to prevent excessive electrons from leaking to the anode side, so that the light emitting efficiency and durability of the device are improved.

The compound represented by the general formula (1) has one of the aromatic hydrocarbon group in which three or more rings are fused, phenanthryl group, fluorenyl group, a Ar ¹ selected from the group of non-triphenylenyl group. In general, an aromatic hydrocarbon group can smoothly and repeatedly perform reduction by electrons and oxidation by holes, which contributes to improving the durability of the light-emitting element. In addition, an aromatic hydrocarbon group in which three or more rings are condensed exhibits stronger fluorescence emission than that in which two rings are condensed, which contributes to an improvement in luminous efficiency. However, phenanthryl group, fluorenyl group and triphenylenyl group among aromatic hydrocarbon groups condensed with three or more rings have an emission spectrum in the ultraviolet region, and blue emission can be obtained by shifting this for a long wavelength. difficult. Therefore, Ar ¹ is an aromatic hydrocarbon group in which three or more rings are condensed, and is selected from groups other than a phenanthryl group, a fluorenyl group, and a triphenylenyl group.

Since the compound represented by the general formula (1) of the present invention has a dibenzothiophene dioxide group and Ar ¹ in the molecule, it has strong fluorescence, high electron affinity, thin film stability, electrochemical It also has features such as stability. Due to these characteristics, when the compound represented by the general formula (1) of the present invention is used in any layer constituting the light emitting device, an organic thin film light emitting device excellent in luminous efficiency and durability can be obtained.

In the general formula (1), when the number of condensed rings constituting Ar ¹ is increased and the conjugated system is extended, the emission spectrum is excessively shifted to the longer wavelength side and exhibits green to red light emission. Is preferably 3 or more and 8 or less.

Ar ¹ preferably includes an anthracenyl group, a benzo [a] anthracenyl group, a pyrenyl group, a chrycenyl group, a dibenzo [g, p] chrysenyl group, a benzo [c] fluorenyl group, a dibenzo [a, c] fluorenyl group, and a fluoranthene skeleton. An aromatic hydrocarbon group etc. are mentioned, Especially preferably, it is an aromatic hydrocarbon group containing a fluoranthene skeleton.

  The aromatic hydrocarbon group containing a fluoranthene skeleton is a group having a fluoranthene skeleton in the molecular structure, and may or may not have a substituent. Adjacent substituents may form a ring. That is, in the present invention, “including a fluoranthene skeleton” includes a skeleton in which a condensed ring is further attached to a part of the fluoranthene skeleton, such as a benzofluoranthene skeleton or a benzoaceanthrylene skeleton. The size of the ring formed by the adjacent substituent is not particularly limited, but a 5-membered ring or a 6-membered ring is preferable from the viewpoint of the stability of the molecular structure. The formed ring may be an aliphatic ring or an aromatic ring. A ring formed by adjacent substituents may further have a substituent, or may be further condensed. The fluoranthene skeleton has a 5-membered 5-membered ring structure. The 5π-electron five-membered ring structure becomes a 6π-electron system when one electron enters (reduced), and aromatic stabilization occurs (Hückel rule). For this reason, the 5-membered ring structure of the 5π electron system exhibits high electron affinity. Therefore, it is preferable because the electron affinity of the compound represented by the general formula (1) can be further increased, and it can contribute to a reduction in driving voltage of the light emitting element and an improvement in durability. The number of carbon atoms of the group containing the fluoranthene skeleton is not particularly limited, but is preferably in the range of 16 or more and 40 or less. Specific examples include a fluoranthenyl group, a benzofluoranthenyl group, a benzoaceanthrylenyl group, a benzoacephenanthrenyl group, an indenofluoranthenyl group, and an acenaphthofluoranthenyl group.

Ar ¹ may be unsubstituted or substituted, but the substituent when substituted is preferably an alkyl group or an aryl group. The position at which Ar ¹ and L ¹ are linked is not particularly limited, but it contributes to the improvement of the fluorescence quantum yield. Therefore, when Ar ¹ is an anthracenyl group, the 9-position and / or the 10-position, the benzo [a] anthracenyl group In the case of 7-position and / or 12-position, in the case of pyrenyl group 1-position, 3-position, 6-position and / or 8-position, in the case of chrycenyl group 6-position and / or 12-position, dibenzo [g, p] chrysenyl group Is 2-position and / or 10-position, benzo [c] fluorenyl group is 5-position and / or 9-position, dibenzo [a, c] fluorenyl group is 3-position and / or 11-position, fluoranthenyl In the case of a group, it is particularly preferred to link at the 3-position.

Furthermore, Ar ¹ is preferably a group represented by the general formula (3).

In the formula, R ^{9 to} R ²⁰ may be the same or different and are each hydrogen, halogen, alkyl group, cycloalkyl group, heterocyclic group, alkenyl group, cycloalkenyl group, alkynyl group, alkoxy group, alkylthio group, It is selected from the group consisting of aryl ether groups, aryl thioether groups, aryl groups, heteroaryl groups, cyano groups, carbonyl groups, carboxyl groups, oxycarbonyl groups, carbamoyl groups, amino groups, and silyl groups. However coupling with ^{L 1} at ^{n 1} or position of ^R 9 ^{to R 20.}

  The group represented by the general formula (3) has a benzofluoranthene skeleton in which one benzene ring is condensed to fluoranthene, and is a skeleton excellent in electron affinity. In addition, since the π-conjugated system is wider than that of fluoranthene, the fluorescence quantum yield is high and strong blue light emission is exhibited, which contributes to high efficiency of the light-emitting element.

When in ^{n 1} single position from among ^{R 11, R 12, R 15} , R 20 of ^R 9 ^{to R 20} is coupled to ^{L 1} in the general formula (3), of the compound represented by the general formula (1) This is preferable because the fluorescence quantum yield is increased and the light emission efficiency is further improved. In particular, it is more preferable to link with L ¹ at the position of R ¹¹ and / or R ^{12 because} the intermolecular interaction is efficiently suppressed and the luminous efficiency is further improved.

In the general formula (1), n ¹ is an integer of 1 or more. However, if the molecular weight of the material is too large, the sublimation property is lowered and the probability of thermal decomposition during vacuum deposition increases. Accordingly, n ¹ is preferably 1 or 2, and particularly preferably n ¹ = 1.

In addition, in the general formula (2), when linked to L ¹ at the position of R ¹ , the intermolecular interaction is suppressed by the twist of the molecule, the amorphous nature of the material and the glass transition temperature are increased, and the stability of the thin film is improved. It is preferable because it improves further. Further, when linked to L ¹ at the position of R ^3, the electron withdrawing property of the dibenzothiophene dioxide group easily acts on the whole molecule, and the electron affinity of the compound represented by the general formula (1) is further increased. Therefore, it is preferable.

  Although it does not specifically limit as a compound represented by General formula (1), Specifically, the following examples are given.

A known method can be used for the synthesis of the compound represented by the general formula (1). First, as a method of synthesizing a precursor having a dibenzothiophene dioxide skeleton, a dibenzothiophene halide is oxidized by heating and stirring with hydrogen peroxide in acetic acid to form a dibenzothiophene dioxide halide. Is mentioned. This presence of a suitable palladium catalyst and a base, and a boronic acid esterification by heating and mixing with pinacol diborane, halogens embodying the Ar ^1, or connecting body and Suzuki Ar ¹ and L ¹ having a halogen on L ¹ -The target compound represented by the general formula (1) can be obtained by performing a Miyaura type coupling reaction, but the method is not limited thereto.

  The compound represented by the general formula (1) is used as a light emitting device material. Here, the light emitting element material represents a material used for any layer of the light emitting element, and is a material used for a layer selected from a hole transport layer, a light emitting layer, and an electron transport layer, as will be described later. In addition, the material used for the protective film of a cathode is also included. By using the compound represented by the general formula (1) in any layer of the light-emitting element, a light-emitting element having high luminous efficiency and excellent durability can be obtained.

  Since the compound represented by the general formula (1) has high electron affinity and fluorescence quantum yield, it is preferably used for the light emitting layer or the electron transporting layer. In particular, it is preferable to use it as a dopant material for the light-emitting layer because it traps excess electrons in the light-emitting layer due to its strong electron affinity, prevents deterioration of the hole transport layer, and improves the durability of the device.

  Moreover, when using the compound represented by General formula (1) as a dopant material of a light emitting layer, when any of the compounds represented by General formula (4)-(7) is used as an electron transport material, more It is preferable because electrons can be injected into the light emitting layer and the light emission efficiency of the light emitting element is improved. In general, increasing the electron injecting property to the light emitting layer by the electron transporting material increases the influence of the electron attack on the hole transporting layer and decreases the durability of the device, but the general formula (1) has high electron affinity. By combining the represented compounds as the dopant material of the light emitting layer, a light emitting element satisfying both the light emission efficiency and the durability life can be obtained.

  The compound represented by the general formula (4) will be described in detail.

In the formula, each of R ^{21 to} R ³⁰ may be the same or different and is hydrogen, halogen, alkyl group, cycloalkyl group, heterocyclic group, alkenyl group, cycloalkenyl group, alkynyl group, alkoxy group, alkylthio group, aryl. It is selected from the group consisting of an ether group, an arylthioether group, an aryl group, a heteroaryl group, a carbonyl group, a carboxyl group, an oxycarbonyl group, a carbamoyl group, an amino group, a silyl group, and —P (═O) R ³¹ R ³² . However coupling with ^{L 2} at the ^{n 2} position of ^R 21 ^{to R 30.} L ² is a single bond, a substituted or unsubstituted arylene group, or a substituted or unsubstituted heteroarylene group, and Ar ² is an aromatic heterocyclic group containing an electron-accepting nitrogen. n ² is an integer of 1 or more. When n ² is 2 or more, L ² and Ar ² may be the same or different.

  Aromatic heterocyclic groups containing electron-accepting nitrogen are pyridyl group, quinolinyl group, isoquinolinyl group, quinoxalinyl group, pyrazinyl group, pyrimidyl group, pyridazinyl group, phenanthrolinyl group, imidazopyridyl group, triazyl group, acridyl group , A benzoimidazolyl group, a benzoxazolyl group, a benzothiazolyl group, and the like, as a non-carbon atom, a cyclic aromatic group having at least one electron-accepting nitrogen atom in the ring. May be unsubstituted or substituted. Since the nitrogen atom has a high electronegativity, the multiple bond has an electron accepting property. Therefore, an aromatic heterocycle containing electron-accepting nitrogen has a high electron affinity. Although carbon number of the aromatic heterocyclic group containing electron-accepting nitrogen is not specifically limited, Usually, it is the range of 2-30. The connecting position of the aromatic heterocyclic group containing electron-accepting nitrogen may be any part. For example, in the case of a pyridyl group, it may be any of 2-pyridyl group, 3-pyridyl group and 4-pyridyl group.

The pyrene compound represented by the general formula (4) has an aromatic heterocycle containing a pyrene skeleton and electron-accepting nitrogen in the molecule. As a result, it is possible to achieve both high electron transportability and electrochemical stability of the pyrene skeleton and high electron acceptability of the aromatic heterocycle containing electron accepting nitrogen, and high electron injecting and transporting ability is exhibited. Ar ² is preferably a pyridyl group, a quinolinyl group, a quinoxalinyl group, a pyrimidyl group, a phenanthrolinyl group, a benzo [d] imidazolyl group, an imidazo [1,2-a] pyridyl group, or the like. More specifically, 2-pyridyl group, 3-pyridyl group, 4-pyridyl group, 2-quinolinyl group, 3-quinolinyl group, 6-quinolinyl group, 1-isoquinolinyl group, 3-isoquinolinyl group, 2-quinoxanyl group, 5-pyrimidyl group, 2-phenanthrolinyl group, 1-benzo [d] imidazolyl group, 2-benzo [d] imidazolyl group, 2-imidazol [1,2-a] pyridyl group, 3-imidazo [1, 2-a] pyridyl group and the like, more preferably 2-pyridyl group, 3-pyridyl group, 4-pyridyl group and the like.

L ² is preferably an arylene group. Since aromatic heterocycles containing electron-accepting nitrogen are vulnerable to oxidation, bonding via an arylene group is more electrochemically stable than bonding directly to a pyrene skeleton. This creates a synergistic effect with the high electron transport property of the pyrene skeleton, and expresses higher electron injecting and transporting ability.

N ² is an integer of 1 or more, but if the molecular weight of the material is too large, the sublimation property is lowered and the probability of thermal decomposition during vacuum deposition increases. Therefore, n ² is preferably 4 or less, more preferably n ² = 1 or 2.

Furthermore, (a) n ² is 1 and linked to L ² at the position of R ²¹ , and R ²⁶ is an aryl group or a heteroaryl group, or (b) n ² is 1, and R ²¹ Linked to L ^{2 at the} position, and R ²³ is an aryl group or a heteroaryl group, and R ²⁶ , R ²⁷ , R ²⁸ are all hydrogen atoms, or (c) n ² is 1, When linking with L ² at the position of R ²¹ , R ²³ is an aryl group or a heteroaryl group, and R ²⁷ is an alkyl group, an aryl group or a heteroaryl group, the steric hindrance of the substituent on the pyrene skeleton Thus, the interaction between the pyrene skeletons is moderately suppressed, and the glass transition temperature is increased. This effect improves the stability of the thin film state and improves the durability of the light emitting element.

  Although it does not specifically limit as a compound represented by General formula (4), Specifically, the compound as described in Chemical Publication 3-Chemical Formula 14 of international publication 2010/113743, Unexamined-Japanese-Patent No. 2011-204844 And the compounds described in Chemical Formulas 9 to 24. The following examples are also included.

  Next, the compounds represented by the general formulas (5) and (6) will be described in detail.

R ^{33 to} R ⁴⁰ may be the same or different and are each hydrogen, halogen, alkyl group, cycloalkyl group, heterocyclic group, alkenyl group, cycloalkenyl group, alkynyl group, alkoxy group, alkylthio group, aryl ether group, It is selected from the group consisting of an arylthioether group, an aryl group, a carbonyl group, a carboxyl group, a carbamoyl group, an amino group, a silyl group, and —P (═O) R ⁴¹ R ⁴² . R ⁴¹ and R ⁴² are an aryl group or a heteroaryl group. R ⁴¹ and R ⁴² may be condensed to form a ring. However, at least one of R ^{33 to} R ⁴⁰ itself has a three-dimensional structure, or has a three-dimensional structure by steric repulsion with a phenanthroline skeleton or an adjacent substituent.

R ^{43 to} R ⁵⁰ may be the same as or different from each other, and may be hydrogen, halogen, alkyl group, cycloalkyl group, heterocyclic group, alkenyl group, cycloalkenyl group, alkynyl group, alkoxy group, alkylthio group, aryl ether group, It is selected from the group consisting of an arylthioether group, an aryl group, a carbonyl group, a carboxyl group, a carbamoyl group, an amino group, a silyl group, and —P (═O) R ⁵¹ R ⁵² . R ⁵¹ and R ⁵² are an aryl group or a heteroaryl group. R ⁵¹ and R ⁵² may be condensed to form a ring. However, each of n ³ phenanthroline skeletons is linked to X at at least one of R ^{43 to} R ⁵⁰ . n ³ is an integer of 2 or more. X is a connecting unit that connects a single bond or a plurality of phenanthroline skeletons.

Regarding R ^{33 to} R ⁴⁰ , the term “having a three-dimensional structure” refers to a structure in which atoms constituting a group are not in the same plane and have an effect of preventing overlapping of molecules by steric repulsion. . Examples of the substituent having a particularly remarkable steric repulsion effect include isopropyl group, t-butyl group, cyclohexyl group, adamantyl group, norbornyl group, 9,9'-dimethylfluorenyl group, 9,9'-diphenylfluorene. Nyl group, spirofluorenyl group, etc. are mentioned. These groups may be unsubstituted or substituted.

  In addition, substituents that give a three-dimensional structure by steric repulsion with the phenanthroline skeleton or adjacent substituents are substituents such as phenyl, naphthyl, phenanthryl, anthryl, pyrenyl, and fluoranthenyl groups. Even if it is a planar structure itself, the steric repulsion between the substituent and the phenanthroline skeleton, or the substituent and the adjacent substituent indicates that the substituent plane is different from the phenanthroline skeleton plane. Specific examples of the substituent that causes steric repulsion with the phenanthroline skeleton include 1-naphthyl group, 9-phenanthryl group, 9-anthryl group, 1-pyrenyl group, and 3-fluoranthenyl group.

  In addition, even if the substituent itself has a poor steric repulsion effect with the phenanthroline skeleton, such as a phenyl group or a 2-naphthyl group, the same steric repulsion may occur if the substituent further has a substituent at the ortho position. An effect is obtained. Specific examples of such a substituent include 2-methylphenyl group, 2,6-dimethylphenyl group, mesityl group, 2-t-butylphenyl group, 2-biphenyl group, 2- (1-methyl) naphthyl group, Examples include 2- (1-t-butyl) naphthyl group and 2- (1-phenyl) naphthyl group. Even when there is no substituent at the ortho position, a steric repulsion effect with the adjacent substituent can be obtained when the adjacent position on the phenanthroline skeleton has a substituent such as a phenyl group.

  A compound containing a phenanthroline skeleton has low planarity and can be crystallized because the substituent itself has a three-dimensional steric structure, or a steric repulsion with the phenanthroline skeleton or a neighboring substituent brings about a three-dimensional steric structure. It is difficult to occur and a good amorphous thin film state can be maintained.

  In addition, by linking a plurality of phenanthroline skeletons, a compound containing a phenanthroline skeleton has a high molecular weight and a glass transition temperature rises, and thus crystallization hardly occurs and a good amorphous thin film state can be maintained.

  Among the compounds having the phenanthroline skeletons of the general formulas (5) and (6) in the present invention, it is more preferable to introduce substituents at the 2, 4, 7, and 9 positions of the phenanthroline skeleton. These substituents are the same as those described above.

N ^{3 in the} general formula (6) is an integer of 2 or more, but if the molecular weight of the material is too large, the sublimation property is lowered and the probability of thermal decomposition during vacuum deposition increases. Therefore, n ^{3 in the} general formula (6) is more preferably 2.

  X in the general formula (6) is not particularly limited, but is preferably an arylene group or a heteroarylene group from the viewpoint of thermal stability and chemical stability, and particularly a benzene ring, a substituent having a terphenyl skeleton, or a naphthalene ring. It is preferable that it is at least 1 sort (s) chosen from these.

When X is a benzene ring, X is preferably a 1,4-phenylene group or a 1,3-phenylene group for ease of synthesis. In this case, at least one of R ^{43 to} R ⁵⁰ is a heat resistant viewpoint. To an aryl group. As the aryl group, unsubstituted or substituted phenyl group, p-tolyl group, m-tolyl group, 3,5-dimethylphenyl group, 4-t-butylphenyl group, etc. from the viewpoint of ease of synthesis and sublimation An unsubstituted or substituted naphthyl group such as a substituted phenyl group, a 1-naphthyl group, a 2-naphthyl group, and a 1- (2-methyl) naphthyl group is more preferable. Further, when X in the general formula (6) is a naphthalene ring, X is a 1,6-naphthylene group, 1,7-naphthylene group, 2,6-naphthylene group, 2,7-naphthylene for ease of synthesis. Groups are more preferred. Further, when X in the general formula (6) is a substituent having a terphenyl skeleton, it is preferably a substituent having the following structure.

  Furthermore, from the viewpoint of sublimability, it is more preferable that the structure has the following structure in which at least one benzene ring is connected at the ortho position.

  The compound represented by the general formula (5) or (6) is not particularly limited, but specifically, compounds described in Chemical Formulas 6 to 9 of JP-A No. 2001-267080, JP-A 2004 The compounds described in Chemical Formulas 3 to 7 and Chemical Formulas 13 to 14 of JP-281390 are listed.

  Next, the compound represented by the general formula (7) will be described in detail.

In the formula, Ar ³ represents an aryl group or a heteroaryl group, and Y is represented by the following general formula (8). L ³ is a single bond, an arylene group or a heteroarylene group. n ⁴ is 1 or 2. When n ⁴ is 2, two Ys may be the same or different.

In the formula, each of ring A and ring B represents a benzene ring, a condensed aromatic hydrocarbon ring, a monocyclic aromatic heterocyclic ring, or a condensed aromatic heterocyclic ring. However, at least one atom constituting ring A and ring B is electron-accepting nitrogen. When ring A and ring B are substituted, and R ⁵³ are each an alkyl group, cycloalkyl group, heterocyclic group, alkenyl group, cycloalkenyl group, alkynyl group, alkoxy group, alkylthio group, aryl It is selected from the group consisting of an ether group, an arylthioether group, an aryl group, a heteroaryl group, a halogen, a carbonyl group, a carboxyl group, an oxycarbonyl group, a carbamoyl group, and —P (═O) R ⁵⁴ R ⁵⁵ . R ⁵³ may be hydrogen. R ⁵⁴ and R ⁵⁵ are an aryl group or a heteroaryl group. R ⁵⁴ and R ⁵⁵ may be condensed to form a ring. However, it is linked to L ⁴ at any position among R ⁵³ , ring A and ring B. When n ⁴ is 2, the positions at which two Y are linked to L ³ may be the same or different.

Connecting to L ³ at any position of R ⁵³ , ring A and ring B means the following. ^First, the coupling with ^{L 3} at the position of ^{R 53 refers} to the nitrogen atom and ^{L 3 which R 53} is linked directly binds. In addition, when linked to L ³ at any position of ring A and ring B, for example, when ring A is a benzene ring, L ³ is directly bonded to any of the carbon atoms constituting the benzene ring. Say.

  Since the compound represented by the general formula (7) has one or two groups represented by Y, the crystallinity is lowered and the glass transition temperature is increased, so that the stability of the film is improved. improves.

  In the compound represented by the general formula (7), in Y, at least one atom constituting ring A and ring B is electron-accepting nitrogen. Since the nitrogen atom has high electronegativity, the multiple bond has an electron accepting property. Therefore, Y having electron-accepting nitrogen has high electron affinity. For this reason, when the compound of General formula (7) is used for an electron carrying layer, the favorable electron injection property from an electrode is shown, and the drive voltage of a light emitting element can be made low. As a result, the light emission efficiency of the light emitting element can be improved.

Y has electron donating nitrogen. In Y, this corresponds to the nitrogen atom to which R ⁵³ is bonded. Electron-donating nitrogen has high stability against holes and can be smoothly and repeatedly oxidized by holes. Therefore, when the compound of the general formula (7) is used for the electron transport layer, deterioration of the electron transport layer due to holes leaked from the light emitting layer can be prevented, and the lifetime of the light emitting element can be improved.

In the general formula (7), Ar ³ is preferably a group containing a fluoranthene skeleton. Since the fluoranthene skeleton has a 5π-electron five-membered ring structure as described above, it has a strong electron affinity and exhibits good electron injectability from the electrode when used in an electron transporting layer. Can be lowered. As a result, the light emission efficiency of the light emitting element can be improved. In addition, it contributes to extending the life of the light emitting element.

  In addition, the fluoranthene skeleton has high planarity and has a high charge transporting property because molecules overlap each other well. Therefore, when the compound represented by the general formula (7) is used for the electron transport layer, electrons generated from the cathode can be transported efficiently, so that the driving voltage of the device can be lowered. As a result, the light emission efficiency of the light emitting element can be improved. In addition, it contributes to extending the life of the light emitting element.

  Further, the fluoranthene skeleton has high charge stability, and can be smoothly and repeatedly reduced by electrons and oxidized by holes. Therefore, when the compound represented by the general formula (7) is used for the electron transport layer, the lifetime can be improved.

  The compound represented by the general formula (7) is preferably a compound represented by the following general formula (9). The compound represented by the general formula (9) is a compound in which the 3-position of the fluoranthene skeleton is substituted with a substituent containing Y. In the fluoranthene derivative, when the 3-position is substituted with an aromatic substituent, the electronic state of the fluoranthene skeleton is greatly changed, and conjugation is efficiently expanded, so that the charge transport property is improved. As a result, the light emitting element can be driven at a low voltage, and the light emission efficiency can be improved. Furthermore, since the conjugation spreads, the stability against charges is also improved.

In the formula, R ^{56 to} R ⁶⁴ may be the same as or different from each other, and are hydrogen, alkyl group, cycloalkyl group, heterocyclic group, alkenyl group, cycloalkenyl group, alkynyl group, alkoxy group, alkylthio group, aryl ether group. , Arylthioether group, aryl group, heteroaryl group, halogen, carbonyl group, carboxyl group, oxycarbonyl group, and carbamoyl group. R ^{56 to} R ⁶⁴ may form a ring with adjacent substituents. L ³ , Y and n ⁴ are the same as those in the general formula (7).

Among the above, R ^{56 to} R ⁶⁴ in the general formula (9) are preferably selected from the group consisting of hydrogen, an alkyl group, a cycloalkyl group, an aryl group, a heteroaryl group, and a halogen. When R ^{56 to} R ⁶⁴ are hydrogen, an alkyl group, a cycloalkyl group, an aryl group, a heteroaryl group, or a halogen, the glass transition temperature is increased and the thin film stability is improved. In addition, since the substituent is difficult to decompose even at high temperatures, the heat resistance is improved. Furthermore, when it is an aryl group or a heteroaryl group, conjugation spreads, so that it becomes more electrochemically stable and charge transportability is improved.

  The group containing a fluoranthene skeleton is preferably a group represented by the following general formula (10). When the group containing a fluoranthene skeleton is a group containing a benzofluoranthene skeleton as represented by the general formula (10), the conjugated system is appropriately expanded. Thereby, it becomes electrochemically stable and further the charge transport property is improved.

In the formula, R ^{65 to} R ⁷⁶ may be the same as or different from each other, and hydrogen, alkyl group, cycloalkyl group, heterocyclic group, alkenyl group, cycloalkenyl group, alkynyl group, alkoxy group, alkylthio group, aryl ether group , Arylthioether group, aryl group, heteroaryl group, halogen, carbonyl group, carboxyl group, oxycarbonyl group, and carbamoyl group. R ^{65 to} R ⁷⁶ may form a ring with adjacent substituents. ^However, connecting the ^{L 3} in one position one of R 65 ^{to R 76.}

Among the above, R ^{65 to} R ⁷⁶ in the general formula (10) are preferably selected from the group consisting of hydrogen, an alkyl group, a cycloalkyl group, an aryl group, a heteroaryl group, and a halogen. When R ^{65 to} R ⁷⁶ are hydrogen, an alkyl group, a cycloalkyl group, an aryl group, a heteroaryl group, or a halogen, the glass transition temperature is increased and the thin film stability is improved. When the thin film stability is improved, the deterioration of the film is suppressed even if the light emitting element is driven for a long time, so that the durability is improved. In addition, since the substituent is difficult to decompose even at high temperatures, the heat resistance is improved. When the heat resistance is improved, the decomposition of the material can be suppressed at the time of device fabrication, so that the durability is improved. Furthermore, when it is an aryl group or a heteroaryl group, conjugation spreads, so that it becomes more electrochemically stable and charge transportability is improved.

R ⁶⁹ and R ⁷⁴ in the general formula (10) are preferably a substituted or unsubstituted aryl group. When R ⁶⁹ and R ⁷⁴ are substituted or unsubstituted aryl groups, it is possible to moderately avoid overlapping of π conjugate planes between molecules. Moreover, heat resistance improves by being an aryl group. As a result, it is possible to improve sublimation, improve deposition stability, decrease crystallinity, and improve thin film stability due to a high glass transition temperature without impairing the high charge transport property of the benzofluoranthene compound.

R ⁶⁹ and R ⁷⁴ in the general formula (10) are more preferably a substituted or unsubstituted phenyl group. When R ⁶⁹ and R ⁷⁴ are substituted or unsubstituted phenyl groups, it is possible to moderately avoid overlapping of π conjugate planes between molecules. Moreover, since it becomes a moderate molecular weight, sublimation property and vapor deposition stability further improve.

The compound represented by the general formula (7) is preferably a compound represented by the following general formula (11). The conjugation of benzo [k] fluoranthene easily spreads at the positions of R ⁶⁵ and R ⁶⁶ , and the conjugation efficiently spreads when R ⁶⁵ is used for linking with L ³ . Thereby, the compound represented by the general formula (11) becomes more electrochemically stable, and the charge transport property is further improved.

In the formula, R ^{77 to} R ⁸⁷ may be the same as or different from each other, and hydrogen, alkyl group, cycloalkyl group, heterocyclic group, alkenyl group, cycloalkenyl group, alkynyl group, alkoxy group, alkylthio group, aryl ether group , Arylthioether group, aryl group, heteroaryl group, halogen, carbonyl group, carboxyl group, oxycarbonyl group, and carbamoyl group. R ^{77 to} R ⁸⁷ may form a ring with adjacent substituents. L ³ , Z and n ⁴ are the same as in the general formula (7).

Among the above, R ^{77 to} R ⁸⁷ in the general formula (11) are preferably selected from the group consisting of hydrogen, an alkyl group, a cycloalkyl group, an aryl group, a heteroaryl group, and a halogen. When R ^{77 to} R ⁸⁷ are hydrogen, an alkyl group, a cycloalkyl group, an aryl group, a heteroaryl group, or a halogen, the glass transition temperature is increased and the thin film stability is improved. In addition, since the substituent is difficult to decompose even at high temperatures, the heat resistance is improved. Furthermore, when it is an aryl group or a heteroaryl group, conjugation spreads, so that it becomes more electrochemically stable and charge transportability is improved.

In the compound represented by the general formula (7), n ⁴ is preferably 1. When n ⁴ is 1, sublimation property and deposition stability are improved.

  Y is preferably a group represented by any one of the following general formulas (12) to (16). When Y is a group represented by any one of the following general formulas (12) to (16), high electron mobility and high electron acceptability are expressed, and the driving voltage of the light emitting element can be lowered. As a result, the light emission efficiency of the light emitting element can be improved.

In the formula, ring B represents a substituted or unsubstituted benzene ring, a substituted or unsubstituted condensed aromatic hydrocarbon ring, a substituted or unsubstituted monocyclic aromatic heterocyclic ring, or a substituted or unsubstituted condensed aromatic heterocyclic ring. Represent. However, in the case of the general formula (12), the ring B is a substituted or unsubstituted monocyclic aromatic heterocyclic ring or a substituted or unsubstituted condensed aromatic heterocyclic ring, and at least one constituting the ring B The atom is electron-accepting nitrogen. When the ring B is substituted, the substituents R ⁵³ and R ^{88 to} R ¹⁰³ are the same as those in the general formula (7). However, in the case of general formula (12), at any position among R ⁵³ , R ^{88 to} R ⁹¹ and ring B, and in the case of general formula (13), among R ⁵³ , R ^{92 to} R ⁹⁴ and ring B In any position, in the case of general formula (14), R ⁵³ , R ^{95 to} R ⁹⁷ , in any position of ring B, in the case of general formula (15), R ⁵³ , R ^{98 to} R ¹⁰⁰ , In the case of general formula (16) at any position in ring B, R ⁵³ , R ^{101 to} R ¹⁰³ , and at any position in ring B are linked to L ³ .

  Ring B preferably has a structure represented by any of the following general formulas (17) to (20). When the ring B has a structure represented by any one of the following general formulas (17) to (20), high carrier mobility and high electron acceptability are expressed. As a result, the light emitting element can be driven at a low voltage, and the light emission efficiency can be improved. In addition, the sublimation property, deposition stability, crystallinity deterioration, and film stability due to high glass transition temperature are improved.

^Wherein, B 1 ^{.about.B 22} represents a substituted or unsubstituted carbon atom or a nitrogen atom. However, when Y is a group represented by the general formula (12), at least one of B ^k (k = 1 to 22) contained in the ring B is electron-accepting nitrogen. The substituents when B ^{1 to} B ²² are substituted are the same as those in the general formula (7).

  Ring B is not particularly limited, but is preferably General Formulas (18) to (20). When the ring B is represented by the general formulas (18) to (20), conjugation is further expanded, and high carrier mobility and high electron acceptability are expressed. As a result, the light emitting element can be driven at a low voltage, and the light emission efficiency can be improved.

  Although it does not specifically limit as a compound represented by General formula (7), The following examples are specifically mentioned.

  Next, embodiments of the light emitting device of the present invention will be described in detail. The light emitting device of the present invention has an anode and a cathode, and an organic layer interposed between the anode and the cathode, and the organic layer includes at least a light emitting layer and an electron transport layer, and the light emitting layer emits light by electric energy. To do.

  The organic layer is composed of only the light emitting layer / electron transport layer, 1) hole transport layer / light emitting layer / electron transport layer and 2) hole transport layer / light emitting layer / electron transport layer / electron injection layer, 3) Laminate structure such as hole injection layer / hole transport layer / light emitting layer / electron transport layer / electron injection layer can be mentioned. Each of the layers may be a single layer or a plurality of layers.

  The compound represented by the general formula (1) may be used in any layer in the above device configuration, but has high electron injection and transport ability, fluorescence quantum yield, and thin film stability. It is preferably used for a light emitting layer or an electron transport layer of a light emitting element. In particular, since it has an excellent fluorescence quantum yield, it is preferably used as a dopant material for the light emitting layer.

  In the light emitting device of the present invention, the anode and the cathode have a role of supplying a sufficient current for light emission of the device, and at least one of them is preferably transparent or translucent in order to extract light. Usually, the anode formed on the substrate is a transparent electrode.

  The material used for the anode is a material that can efficiently inject holes into the organic layer, and is transparent or translucent to extract light. Tin oxide, indium oxide, indium tin oxide (ITO) indium zinc oxide (IZO) Although not particularly limited, such as conductive metal oxides such as, metals such as gold, silver and chromium, inorganic conductive materials such as copper iodide and copper sulfide, conductive polymers such as polythiophene, polypyrrole and polyaniline It is particularly preferable to use ITO glass or Nesa glass. These electrode materials may be used alone, or a plurality of materials may be laminated or mixed. The resistance of the transparent electrode is not limited as long as it can supply a sufficient current for light emission of the element, but it is preferably low resistance from the viewpoint of power consumption of the element. For example, an ITO substrate with a resistance of 300Ω / □ or less will function as a device electrode, but since it is now possible to supply a substrate with a resistance of approximately 10Ω / □, use a substrate with a low resistance of 20Ω / □ or less. Is particularly preferred. The thickness of ITO can be arbitrarily selected according to the resistance value, but is usually used in a range of 100 to 300 nm.

In order to maintain the mechanical strength of the light emitting element, the light emitting element is preferably formed over a substrate. As the substrate, a glass substrate such as soda glass or non-alkali glass is preferably used. As the thickness of the glass substrate, it is sufficient that the thickness is sufficient to maintain the mechanical strength. As for the glass material, alkali-free glass is preferred because it is better that there are fewer ions eluted from the glass. Alternatively, soda lime glass provided with a barrier coat such as SiO ₂ is also commercially available and can be used. Furthermore, if the first electrode functions stably, the substrate need not be glass, and for example, an anode may be formed on a plastic substrate. The ITO film forming method is not particularly limited, such as an electron beam method, a sputtering method, and a chemical reaction method.

  The material used for the cathode is not particularly limited as long as it can efficiently inject electrons into the light emitting layer. Generally, metals such as platinum, gold, silver, copper, iron, tin, aluminum, and indium, or alloys and multilayer stacks of these metals with low work function metals such as lithium, sodium, potassium, calcium, and magnesium Is preferred. Among these, aluminum, silver, and magnesium are preferable as the main component from the viewpoints of electrical resistance, ease of film formation, film stability, luminous efficiency, and the like. In particular, magnesium and silver are preferable because electron injection into the electron transport layer and the electron injection layer in the present invention is facilitated and low voltage driving is possible.

  Furthermore, for cathode protection, metals such as platinum, gold, silver, copper, iron, tin, aluminum and indium, or alloys using these metals, inorganic materials such as silica, titania and silicon nitride, polyvinyl alcohol, polyvinyl chloride As a preferred example, an organic polymer compound such as a hydrocarbon polymer compound is laminated on the cathode as a protective film layer. Moreover, the compound represented by General formula (1) can also be utilized as this protective film layer. However, in the case of an element structure (top emission structure) that extracts light from the cathode side, the protective film layer is selected from materials that are light transmissive in the visible light region. The production method of these electrodes is not particularly limited, such as resistance heating, electron beam, sputtering, ion plating and coating.

  The hole transport layer is formed by a method of laminating or mixing one or more hole transport materials or a method using a mixture of a hole transport material and a polymer binder. In addition, the hole transport material needs to efficiently transport holes from the positive electrode between electrodes to which an electric field is applied, has high hole injection efficiency, and can efficiently transport injected holes. preferable. For this purpose, it is required that the material has an appropriate ionization potential, has a high hole mobility, is excellent in stability, and does not easily generate trapping impurities during manufacture and use. Although it does not specifically limit as a substance which satisfy | fills such conditions, For example, 4,4'-bis (N- (3-methylphenyl) -N-phenylamino) biphenyl (TPD), 4,4 ' -Bis (N- (1-naphthyl) -N-phenylamino) biphenyl (NPD), 4,4'-bis (N, N-bis (4-biphenylyl) amino) biphenyl (TBDB), bis (N, N Benzidine derivatives such as '-diphenyl-4-aminophenyl) -N, N-diphenyl-4,4'-diamino-1,1'-biphenyl (TPD232), 4,4', 4 "-tris (3-methylphenyl) (Phenyl) amino) triphenylamine (m-MTDATA), 4,4 ′, 4 ″ -tris (1-naphthyl (phenyl) amino) triphenylamine (1-TNATA) A group of materials called starburst arylamines, materials having a carbazole skeleton, among them carbazole multimers, specifically carbazole dimer derivatives such as bis (N-arylcarbazole) or bis (N-alkylcarbazole), carbazole Trimer derivatives, carbazole tetramer derivatives, triphenylene compounds, pyrazoline derivatives, stilbene compounds, hydrazone compounds, benzofuran derivatives and thiophene derivatives, oxadiazole derivatives, phthalocyanine derivatives, porphyrin derivatives and other heterocyclic compounds, fullerenes In derivatives and polymer systems, polycarbonate having a monomer in the side chain, styrene derivative, polythiophene, polyaniline, polyfluorene, polyvinylcarbazole, polysilane, and the like are preferable.Furthermore, inorganic compounds such as p-type Si and p-type SiC can also be used.

  The compound represented by the general formula (1) can also be used as a hole transporting material because of its high hole mobility and excellent electrochemical stability. The compound represented by the general formula (1) may be used as a hole injection material, but is preferably used as a hole transport material because of its high hole mobility.

  In addition, since the compound represented by the general formula (1) has excellent electron injecting and transporting properties, when it is used in a light emitting layer or an electron transporting layer, electrons do not recombine in the light emitting layer, and some holes are transported. There is a concern that even the layer will leak. Therefore, it is preferable to use a compound having an excellent electron blocking property for the hole transport layer. Among these, a compound containing a carbazole skeleton is preferable because it has excellent electron blocking properties and can contribute to the improvement in efficiency of the light-emitting element. Further, the compound containing a carbazole skeleton preferably contains a carbazole dimer, a carbazole trimer, or a carbazole tetramer skeleton. This is because they have both a good electron blocking property and a hole injection / transport property. In addition, it is preferable to use a compound containing a triphenylene skeleton, which is excellent in having high hole mobility, in the hole transport layer because the effects of improving the carrier balance and improving the light emission efficiency and durability are obtained. More preferably, the compound containing a triphenylene skeleton has two or more diarylamino groups. The compound containing a carbazole skeleton or the compound containing a triphenylene skeleton may be used alone as a hole transport layer, or may be used as a mixture with each other. Further, other materials may be mixed within a range not impairing the effects of the present invention. In the case where the hole transport layer is composed of a plurality of layers, any one layer may contain a compound containing a carbazole skeleton or a compound containing a triphenylene skeleton.

  A hole injection layer may be provided between the anode and the hole transport layer. By providing the hole injection layer, the light emitting element has a low driving voltage and the durability life is improved. For the hole injection layer, a material having a smaller ionization potential than that of the material normally used for the hole transport layer is preferably used. Specifically, a benzidine derivative such as TPD232 and a starburst arylamine material group can be used, and a phthalocyanine derivative can also be used. It is also preferred that the hole injection layer is composed of an acceptor compound alone or that the acceptor compound is doped with another hole transport material. Examples of acceptor compounds include metal chlorides such as iron (III) chloride, aluminum chloride, gallium chloride, indium chloride, antimony chloride, metal oxides such as molybdenum oxide, vanadium oxide, tungsten oxide, ruthenium oxide, A charge transfer complex such as tris (4-bromophenyl) aminium hexachloroantimonate (TBPAH). In addition, organic compounds having a nitro group, cyano group, halogen or trifluoromethyl group in the molecule, quinone compounds, acid anhydride compounds, fullerenes, and the like are also preferably used. Specific examples of these compounds include hexacyanobutadiene, hexacyanobenzene, tetracyanoethylene, tetracyanoquinodimethane (TCNQ), tetrafluorotetracyanoquinodimethane (F4-TCNQ), 2, 3, 6, 7 , 10,11-hexacyano-1,4,5,8,9,12-hexaazatriphenylene (HAT-CN6), p-fluoranyl, p-chloranil, p-bromanyl, p-benzoquinone, 2,6-dichlorobenzoquinone 2,5-dichlorobenzoquinone, tetramethylbenzoquinone, 1,2,4,5-tetracyanobenzene, o-dicyanobenzene, p-dicyanobenzene, 1,4-dicyanotetrafluorobenzene, 2,3-dichloro-5 , 6-Dicyanobenzoquinone, p-dinitrobenzene, m-dini Lobenzene, o-dinitrobenzene, p-cyanonitrobenzene, m-cyanonitrobenzene, o-cyanonitrobenzene, 1,4-naphthoquinone, 2,3-dichloronaphthoquinone, 1-nitronaphthalene, 2-nitronaphthalene, 1,3-dinitro Naphthalene, 1,5-dinitronaphthalene, 9-cyanoanthracene, 9-nitroanthracene, 9,10-anthraquinone, 1,3,6,8-tetranitrocarbazole, 2,4,7-trinitro-9-fluorenone, 2 , 3,5,6-tetracyanopyridine, maleic anhydride, phthalic anhydride, C60, and C70.

  Among these, metal oxides and cyano group-containing compounds are preferable because they are easy to handle and easy to deposit, so that the above-described effects can be easily obtained. Examples of preferred metal oxides include molybdenum oxide, vanadium oxide, or ruthenium oxide. Among the cyano group-containing compounds, (a) a compound having in the molecule at least one electron-accepting nitrogen other than the nitrogen atom of the cyano group, and (b) a compound having both a halogen and a cyano group in the molecule (C) a compound having both a carbonyl group and a cyano group in the molecule, or (d) at least one electron other than the nitrogen atom of the cyano group, having both a halogen and a cyano group in the molecule. A compound having an accepting nitrogen is more preferable because it becomes a strong electron acceptor. Specific examples of such a compound include the following compounds.

  In any case where the hole injection layer is composed of an acceptor compound alone or when the hole injection layer is doped with an acceptor compound, the hole injection layer may be a single layer, A plurality of layers may be laminated. Moreover, the hole injection material used in combination when the acceptor compound is doped is the same compound as the compound used for the hole transport layer from the viewpoint that the hole injection barrier to the hole transport layer can be relaxed. Is more preferable.

  The light emitting layer may be either a single layer or a plurality of layers, each formed by a light emitting material (host material, dopant material), which may be a mixture of a host material and a dopant material or a host material alone, Either is acceptable. That is, in the light emitting element 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 using electric energy and obtaining light emission with high color purity, the light emitting layer is preferably composed of a mixture of a host material and a dopant material. Further, the host material and the dopant material may be either one kind or a plurality of combinations, respectively. The dopant material may be included in the entire host material or may be partially included. The dopant material may be laminated or dispersed. The dopant material can control the emission color. If the amount of the dopant material is too large, a concentration quenching phenomenon occurs, so that it is preferably used at 20% by weight or less, more preferably 10% by weight or less with respect to the host material. The doping method can be formed by a co-evaporation method with a host material, but may be simultaneously deposited after being previously mixed with the host material.

  Specifically, the light-emitting material includes fused ring derivatives such as anthracene and pyrene, which have been known as light emitters, metal chelated oxinoid compounds such as tris (8-quinolinolato) aluminum, bisstyrylanthracene derivatives and diesters. Bisstyryl derivatives such as styrylbenzene derivatives, tetraphenylbutadiene derivatives, indene derivatives, coumarin derivatives, oxadiazole derivatives, pyrrolopyridine derivatives, perinone derivatives, cyclopentadiene derivatives, oxadiazole derivatives, thiadiazolopyridine derivatives, dibenzofuran derivatives, carbazole In derivatives, indolocarbazole derivatives, and polymer systems, polyphenylene vinylene derivatives, polyparaphenylene derivatives, polythiophene derivatives, etc. can be used, but are not particularly limited. Not.

  The compound represented by the general formula (1) can also be used as a light-emitting material because of its high fluorescence quantum yield and excellent electrochemical stability. Although the compound represented by the general formula (1) may be used as a host material, it has a strong electron affinity. Therefore, when used as a dopant material, it has an effect of trapping excess electrons injected into the light emitting layer. Therefore, it is particularly preferable because the hole transport layer can be prevented from being deteriorated by an electron attack.

  The host material contained in the light emitting material is not particularly limited, but other than the compound represented by the general formula (1), naphthalene, anthracene, phenanthrene, pyrene, chrysene, naphthacene, triphenylene, perylene, fluoranthene, fluorene, indene, etc. Compounds having condensed aryl rings and derivatives thereof, aromatic amine derivatives such as N, N′-dinaphthyl-N, N′-diphenyl-4,4′-diphenyl-1,1′-diamine, tris (8-quinolinate) Metal chelated oxinoid compounds such as aluminum (III), bisstyryl derivatives such as distyrylbenzene derivatives, tetraphenylbutadiene derivatives, indene derivatives, coumarin derivatives, oxadiazole derivatives, pyrrolopyridine derivatives, perinone derivatives, cyclopentadiene Conductors, pyrrolopyrrole derivatives, thiadiazolopyridine derivatives, dibenzofuran derivatives, carbazole derivatives, indolocarbazole derivatives, triazine derivatives, polymers, polyphenylene vinylene derivatives, polyparaphenylene derivatives, polyfluorene derivatives, polyvinylcarbazole derivatives, polythiophene derivatives, etc. Can be used, but is not particularly limited. The dopant material is not particularly limited, but in addition to the compound represented by the general formula (1), a compound having a condensed aryl ring such as naphthalene, anthracene, phenanthrene, pyrene, chrysene, triphenylene, perylene, fluoranthene, fluorene, and indene And derivatives thereof (eg 2- (benzothiazol-2-yl) -9,10-diphenylanthracene and 5,6,11,12-tetraphenylnaphthacene), furan, pyrrole, thiophene, silole, 9-silafluorene 9,9′-spirobisilafluorene, benzothiophene, benzofuran, indole, dibenzothiophene, dibenzofuran, imidazopyridine, phenanthroline, pyridine, pyrazine, naphthyridine, quinoxaline, pyrrolopyridine, thioxanthene Compounds having a heteroaryl ring, derivatives thereof, borane derivatives, distyrylbenzene derivatives, 4,4′-bis (2- (4-diphenylaminophenyl) ethenyl) biphenyl, 4,4′-bis (N- (stilbene) Aminostyryl derivatives such as -4-yl) -N-phenylamino) stilbene, aromatic acetylene derivatives, tetraphenylbutadiene derivatives, stilbene derivatives, aldazine derivatives, pyromethene derivatives, diketopyrrolo [3,4-c] pyrrole derivatives, 2, 3,5,6-1H, 4H-tetrahydro-9- (2′-benzothiazolyl) quinolidino [9,9a, 1-gh] coumarin derivatives such as coumarin, imidazole, thiazole, thiadiazole, carbazole, oxazole, oxadiazole, Azole such as triazole Conductors and metal complexes thereof, and aromatic amine derivatives represented by N, N′-diphenyl-N, N′-di (3-methylphenyl) -4,4′-diphenyl-1,1′-diamine are used. be able to.

  The light emitting layer may contain a phosphorescent material. A phosphorescent material is a material that exhibits phosphorescence even at room temperature. When a phosphorescent material is used as a dopant, it is basically necessary to obtain phosphorescence even at room temperature, but there is no particular limitation, and iridium (Ir), ruthenium (Ru), rhodium (Rh), An organometallic complex compound containing at least one metal selected from the group consisting of palladium (Pd), platinum (Pt), osmium (Os), and rhenium (Re) is preferable. Among these, from the viewpoint of having a high phosphorescence emission yield even at room temperature, an organometallic complex having iridium or platinum is more preferable. Hosts used in combination with a phosphorescent dopant include indole derivatives, carbazole derivatives, indolocarbazole derivatives, pyridine, pyrimidine, nitrogen-containing aromatic compound derivatives having a triazine skeleton, polyarylbenzene derivatives, spirofluorene derivatives, Aromatic hydrocarbon compound derivatives such as truxene derivatives and triphenylene derivatives, compounds containing chalcogen elements such as dibenzofuran derivatives and dibenzothiophene derivatives, and organometallic complexes such as beryllium quinolinol complexes are preferably used. It is not limited to these as long as the energy is high and electrons and holes are smoothly injected and transported from the respective transport layers. Two or more triplet light-emitting dopants may be contained, or two or more host materials may be contained. Further, one or more triplet light emitting dopants and one or more fluorescent light emitting dopants may be contained.

  The preferred phosphorescent host or dopant is not particularly limited, but specific examples include the following.

  In the present invention, the electron transport layer is a layer in which electrons are injected from the cathode and further transports electrons. The electron transport layer has high electron injection efficiency, and it is desired to efficiently transport injected electrons. Therefore, the electron transport layer is preferably made of a material having a high electron affinity, a high electron mobility, excellent stability, and impurities that are traps are less likely to be generated during manufacture and use. However, considering the transport balance between holes and electrons, if the electron transport layer mainly plays a role of effectively preventing the holes from the anode from recombining and flowing to the cathode side, the electron transport Even if it is made of a material that does not have a high capability, the effect of improving the luminous efficiency is equivalent to that of a material that has a high electron transport capability. Therefore, the electron transport layer in the present invention includes a hole blocking layer that can efficiently block the movement of holes as the same meaning.

  Examples of the electron transport material used in the electron transport layer include condensed polycyclic aromatic derivatives such as naphthalene and anthracene, styryl aromatic ring derivatives represented by 4,4′-bis (diphenylethenyl) biphenyl, anthraquinone, diphenoquinone, and the like. Quinoline derivatives, phosphorus oxide derivatives, quinolinol complexes such as tris (8-quinolinolato) aluminum (III), benzoquinolinol complexes, hydroxyazole complexes, azomethine complexes, tropolone metal complexes, and flavonol metal complexes. A compound having a heteroaryl ring structure composed of an element selected from carbon, hydrogen, nitrogen, oxygen, silicon, and phosphorus and containing electron-accepting nitrogen, because driving voltage is reduced and high-efficiency light emission is obtained. Is preferably used.

  An aromatic heterocyclic ring containing electron-accepting nitrogen has a high electron affinity. An electron transport material having electron-accepting nitrogen makes it easier to receive electrons from a cathode having a high electron affinity, and can be driven at a lower voltage. In addition, since the number of electrons supplied to the light emitting layer is increased and the recombination probability is increased, the light emission efficiency is improved.

  Examples of the heteroaryl ring containing an electron-accepting nitrogen include, for example, a pyridine ring, pyrazine ring, pyrimidine ring, quinoline ring, quinoxaline ring, naphthyridine ring, pyrimidopyrimidine ring, benzoquinoline ring, phenanthroline ring, imidazole ring, oxazole ring, Examples thereof include an oxadiazole ring, a triazole ring, a thiazole ring, a thiadiazole ring, a benzoxazole ring, a benzothiazole ring, a benzimidazole ring, and a phenanthrimidazole ring.

  Examples of these compounds having a heteroaryl ring structure include benzimidazole derivatives, benzoxazole derivatives, benzthiazole derivatives, oxadiazole derivatives, thiadiazole derivatives, triazole derivatives, pyrazine derivatives, phenanthroline derivatives, quinoxaline derivatives, quinoline derivatives, benzoins. Preferred compounds include quinoline derivatives, oligopyridine derivatives such as bipyridine and terpyridine, quinoxaline derivatives and naphthyridine derivatives. Among them, imidazole derivatives such as tris (N-phenylbenzimidazol-2-yl) benzene, oxadiazole derivatives such as 1,3-bis [(4-tert-butylphenyl) 1,3,4-oxadiazolyl] phenylene, Triazole derivatives such as N-naphthyl-2,5-diphenyl-1,3,4-triazole, phenanthroline derivatives such as bathocuproine and 1,3-bis (1,10-phenanthroline-9-yl) benzene, 2,2 ′ A benzoquinoline derivative such as bis (benzo [h] quinolin-2-yl) -9,9′-spirobifluorene, 2,5-bis (6 ′-(2 ′, 2 ″ -bipyridyl))-1, Bipyridine derivatives such as 1-dimethyl-3,4-diphenylsilole, 1,3-bis (4 ′-(2,2 ′: 6′2 ″ -ta Terpyridine derivatives such as pyridinyl)) benzene, naphthyridine derivatives such as bis (1-naphthyl) -4- (1,8-naphthyridin-2-yl) phenylphosphine oxide are preferably used from the viewpoint of electron transporting capability. In addition, it is more preferable that these derivatives have a condensed polycyclic aromatic skeleton because the glass transition temperature is improved, the electron mobility is increased, and the effect of lowering the voltage of the light-emitting element is increased. Furthermore, considering that the device durability life is improved, the synthesis is easy, and the availability of raw materials is easy, the condensed polycyclic aromatic skeleton is particularly preferably an anthracene skeleton, a pyrene skeleton or a phenanthroline skeleton. The electron transport material may be used alone, but two or more of the electron transport materials may be mixed and used, or one or more of the other electron transport materials may be mixed with the electron transport material.

  Although it does not specifically limit as a preferable electron transport material, The following examples are specifically mentioned.

  Besides these, International Publication No. 2004-63159, International Publication No. 2003-60956, Appl. Phys. Lett. 74, 865, Org. Electron. 4, 113 (2003), International Publication No. 2010-113743, An electron transport material disclosed in International Publication No. 2010-1817 and the like can also be used.

  In addition, the compound represented by the general formula (1) is also preferably used as an electron transporting material because it has a high electron injecting and transporting ability. When the compound represented by the general formula (1) is used, it is not necessary to limit to only one of them, and a mixture of the compounds represented by the general formula (1) of the present invention may be used. One or more electron transport materials may be mixed with the compound represented by the general formula (1) of the present invention as long as the effects of the present invention are not impaired.

  The electron transport material that can be mixed is not particularly limited, but is a compound having a condensed aryl ring such as naphthalene, anthracene, or pyrene or a derivative thereof, or a styryl-based fragrance typified by 4,4′-bis (diphenylethenyl) biphenyl. Ring derivatives, perylene derivatives, perinone derivatives, coumarin derivatives, naphthalimide derivatives, quinone derivatives such as anthraquinone and diphenoquinone, carbazole derivatives and indole derivatives, quinolinol complexes such as tris (8-quinolinolato) aluminum (III), and hydroxyphenyloxazole complexes Hydroxyazole complexes, azomethine complexes, tropolone metal complexes and flavonol metal complexes.

  Moreover, as mentioned above, when using the compound represented by General formula (1) as a dopant material of a light emitting layer, when any of the compounds represented by General formula (4)-(7) is used as an electron transport material. This is particularly preferable because more electrons can be injected into the light emitting layer and the driving voltage and light emission efficiency of the light emitting element are improved.

  The electron transport material may be used alone, but two or more of the electron transport materials may be mixed and used, or one or more of the other electron transport materials may be mixed with the electron transport material. Moreover, you may contain a donor compound. Here, the donor compound is a compound that facilitates electron injection from the cathode or the electron injection layer to the electron transport layer by improving the electron injection barrier and further improves the electrical conductivity of the electron transport layer.

  Preferred examples of the donor compound in the present invention include an alkali metal, an inorganic salt containing an alkali metal, a complex of an alkali metal and an organic substance, an alkaline earth metal, an inorganic salt containing an alkaline earth metal, or an alkaline earth metal. And a complex of organic substance. Preferable types of alkali metals and alkaline earth metals include alkali metals such as lithium, sodium and cesium, which have a low work function and a large effect of improving the electron transport ability, and alkaline earth metals such as magnesium and calcium.

In addition, since it is easy to deposit in vacuum and is excellent in handling, it is preferably in the form of a complex with an inorganic salt or an organic substance rather than a single metal. Furthermore, it is more preferable that it is in the state of a complex with an organic substance in terms of facilitating handling in the air and easy control of the addition concentration. Examples of inorganic salts include oxides such as LiO and Li ₂ O, nitrides, fluorides such as LiF, NaF, and KF, Li ₂ CO ₃ , Na ₂ CO ₃ , K ₂ CO ₃ , Rb ₂ CO ₃ , Examples thereof include carbonates such as Cs ₂ CO ₃ . A preferable example of the alkali metal or alkaline earth metal is lithium from the viewpoint that the raw materials are inexpensive and easy to synthesize. Preferred examples of the organic substance in the complex with the organic substance include quinolinol, benzoquinolinol, flavonol, hydroxyimidazopyridine, hydroxybenzazole, hydroxytriazole and the like. Among these, a complex of an alkali metal and an organic substance is preferable, a complex of lithium and an organic substance is more preferable, and lithium quinolinol is particularly preferable. Two or more of these donor compounds may be mixed and used.

  The preferred doping concentration varies depending on the material and the thickness of the doped region. For example, when the donor compound is an inorganic material such as an alkali metal or alkaline earth metal, the deposition rate ratio of the electron transport material and the donor compound is 10,000: It is preferable to use an electron transport layer by co-evaporation so as to be in the range of 1 to 2: 1. The deposition rate ratio is more preferably 100: 1 to 5: 1, and further preferably 100: 1 to 10: 1. When the donor compound is a complex of a metal and an organic substance, the electron transport layer and the donor compound are co-deposited so that the deposition rate ratio of the donor compound is in the range of 100: 1 to 1: 100. Is preferred. The deposition rate ratio is more preferably 10: 1 to 1:10, and more preferably 7: 3 to 3: 7.

  Further, the electron transport layer in which the compound represented by the general formula (1) is doped with a donor compound may be used as a charge generation layer in a tandem structure type element that connects a plurality of light emitting elements. Good.

  The method of doping the electron transport layer with a donor compound to improve the electron transport capability is particularly effective when the thin film layer is thick. It is particularly preferably used when the total film thickness of the electron transport layer and the light emitting layer is 50 nm or more. For example, there is a method of using the interference effect to improve the light emission efficiency, but this improves the light extraction efficiency by matching the phase of the light directly emitted from the light emitting layer and the light reflected by the cathode. Is. This optimum condition varies depending on the light emission wavelength, but the total film thickness of the electron transport layer and the light-emitting layer is 50 nm or more, and in the case of long-wavelength light emission such as red, it may be a thick film near 100 nm. .

  The electron transport layer to be doped may have either a part or all of the electron transport layer. In the case of partial doping, it is desirable to provide a doping region at least at the electron transport layer / cathode interface, and the effect of lowering the voltage can be obtained only by doping in the vicinity of the cathode interface. On the other hand, if the donor compound is in direct contact with the light emitting layer, it may adversely affect the light emission efficiency. In that case, it is preferable to provide a non-doped region at the light emitting layer / electron transport layer interface.

In the present invention, an electron injection layer may be provided between the cathode and the electron transport layer. In general, the electron injection layer is inserted for the purpose of assisting injection of electrons from the cathode to the electron transport layer, but in the case of insertion, a compound having a heteroaryl ring structure containing electron-accepting nitrogen may be used. A layer containing the above donor compound may be used. The compound represented by the general formula (1) may be included in the electron injection layer. An insulator or a semiconductor inorganic substance can also be used for the electron injection layer. Use of these materials is preferable because a short circuit of the light emitting element can be effectively prevented and the electron injection property can be improved. As such an insulator, it is preferable to use 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. If the electron injection layer is composed of these alkali metal chalcogenides or the like, it is more preferable because the electron injection property can be further improved. Specifically, preferred alkali metal chalcogenides include, for example, Li ₂ O, Na ₂ S, and Na ₂ Se, and preferred alkaline earth metal chalcogenides include, for example, CaO, BaO, SrO, BeO, BaS, and CaSe. Is mentioned. Further, preferable alkali metal halides include, for example, LiF, NaF, KF, LiCl, KCl, and NaCl. Examples of preferable alkaline earth metal halides include fluorides such as CaF ₂ , BaF ₂ , SrF ₂ , MgF ₂ and BeF ₂ , and halides other than fluorides. Furthermore, a complex of an organic substance and a metal is also preferably used. In the case where a complex of an organic substance and a metal is used for the electron injection layer, the film thickness can be easily adjusted. Examples of such organometallic complexes include quinolinol, benzoquinolinol, pyridylphenol, flavonol, hydroxyimidazopyridine, hydroxybenzazole, hydroxytriazole, and the like as preferred examples of the organic substance in a complex with an organic substance. Among these, a complex of an alkali metal and an organic substance is preferable, a complex of lithium and an organic substance is more preferable, and lithium quinolinol is particularly preferable.

  The method of forming each layer constituting the light emitting element is not particularly limited, such as resistance heating vapor deposition, electron beam vapor deposition, sputtering, molecular lamination method, coating method, etc., but resistance heating vapor deposition or electron beam vapor deposition is usually used in terms of element characteristics. preferable.

  The thickness of the organic layer is not limited because it depends on the resistance value of the luminescent material, but is preferably 1 to 1000 nm. The film thicknesses of the light emitting layer, the electron transport layer, and the hole transport layer are each preferably 1 nm to 200 nm, and more preferably 5 nm to 100 nm.

  The light-emitting element of the present invention has a function of converting electrical energy into light. Here, a direct current is mainly used as the electric energy, but a pulse current or an alternating current can also be used. The current value and voltage value are not particularly limited, but should be selected so that the maximum luminance can be obtained with as low energy as possible in consideration of the power consumption and lifetime of the device.

  The light emitting device of the present invention is suitably used as a display for displaying in a matrix and / or segment system, for example.

  In the matrix method, pixels for display are two-dimensionally arranged such as a lattice shape or a mosaic shape, and a character or an image is displayed by a set of pixels. The shape and size of the pixel are determined by the application. For example, a square pixel with a side of 300 μm or less is usually used for displaying images and characters on a personal computer, monitor, TV, and a pixel with a side of mm order for a large display such as a display panel. become. In monochrome display, pixels of the same color may be arranged. However, in color display, red, green, and blue pixels are displayed side by side. In this case, there are typically a delta type and a stripe type. The matrix driving method may be either a line sequential driving method or an active matrix. Although the structure of the line sequential drive is simple, the active matrix may be superior in consideration of the operation characteristics, and it is necessary to use it depending on the application.

  The segment system in the present invention is a system in which a pattern is formed so as to display predetermined information and an area determined by the arrangement of the pattern is caused to emit light. For example, the time and temperature display in a digital clock or a thermometer, the operation state display of an audio device or an electromagnetic cooker, the panel display of an automobile, etc. The matrix display and the segment display may coexist in the same panel.

  The light emitting device of the present invention is also preferably used as a backlight for various devices. The backlight is used mainly for the purpose of improving the visibility of a display device that does not emit light, and is used for a liquid crystal display device, a clock, an audio device, an automobile panel, a display panel, a sign, and the like. In particular, the light-emitting element of the present invention is preferably used for a backlight for a liquid crystal display device, particularly a personal computer for which a reduction in thickness is being considered, and a backlight that is thinner and lighter than conventional ones can be provided.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated, this invention is not limited by these Examples.

Synthesis example 1
Synthesis of compound [1]

19.6 g of 3-bromodibenzothiophene and 300 ml of acetic acid were mixed, 200 ml of 30 wt% hydrogen peroxide water was added dropwise, and the mixture was heated to reflux under a nitrogen stream. Two hours later, after cooling to room temperature, 500 mL of water was added. The resulting precipitate was filtered and vacuum dried to obtain 21.3 g of intermediate A (yield 97%).
Next, 21.3 g of intermediate A, 27.5 g of bispinacolatodiboron, 21.2 g of potassium acetate, and 400 ml of DMF were mixed and purged with nitrogen. To this mixed solution was added 588 mg of diphenylphosphinoferrocene palladium dichloride dichloromethane complex, and the mixture was stirred at 100 ° C. Two hours later, after cooling to room temperature, 400 ml of toluene and 500 ml of water were added for liquid separation, and the organic layer was dried over magnesium sulfate. After the solvent was distilled off, purification was performed by silica gel column chromatography (toluene / ethyl acetate = 20: 1), and the eluate was concentrated. Methanol was added to the obtained solid, filtered, and then vacuum-dried to obtain 20.0 g of intermediate B (yield 81%).

  Next, 5.00 g of 9-bromoanthracene, 5.31 g of 4- (1-naphthylphenyl) boronic acid, 97 ml of 1,2-dimethoxyethane, and 21.4 ml of 2.0 M aqueous sodium carbonate solution were mixed and purged with nitrogen. 136 mg of bis (triphenylphosphine) palladium dichloride was added to this mixed solution, and the mixture was heated to reflux. Two hours later, after cooling to room temperature, 100 ml of water was added and the precipitated gray solid was collected by filtration. The solid collected by filtration was dissolved by heating in 500 ml of toluene, 1.5 g of activated carbon was added, and the mixture was stirred at room temperature for 30 minutes, filtered through Celite, and the solvent was distilled off. Methanol was added to the precipitated solid and collected by filtration. The obtained solid was vacuum-dried to obtain 7.1 g (yield 96%) of a light yellow solid intermediate C.

  Next, 7.1 g of intermediate C, 3.32 g of N-bromosuccinimide, and 93 ml of 1,2-dimethoxyethane were mixed and stirred at 50 ° C. for 2 hours. After cooling to room temperature, 100 ml of water was added and the precipitated solid was collected by filtration. The obtained solid was washed with 100 ml of water and 100 ml of methanol and then vacuum-dried to obtain 7.9 g of intermediate D (yield 92%).

Next, 3.00 g of intermediate D, 2.46 g of intermediate B, 33 ml of 1,2-dimethoxyethane, and 7.2 ml of 2.0 M aqueous sodium carbonate solution were mixed and purged with nitrogen. To this mixed solution was added 46 mg of bis (triphenylphosphine) palladium dichloride, and the mixture was heated to reflux. Two hours later, after cooling to room temperature, 100 ml of water was added and the precipitated gray solid was collected by filtration. The solid collected by filtration was dissolved by heating in 500 ml of THF, 460 mg of activated carbon and 210 mg of QuadrasilMP (registered trademark) were added, and the mixture was heated to reflux for 1 hour. The solution was cooled to room temperature, filtered through celite, and the solvent was distilled off. The obtained solid was purified by toluene recrystallization and vacuum-dried to obtain 2.72 g (yield 70%) of a yellow solid. The results of ¹ H-NMR analysis of the obtained powder are as follows, and it was confirmed that the yellow crystals obtained above were the compound [1].
¹ H-NMR (CDCl ₃ (δ = ppm)) δ 8.22-8.15 (m, 1H), 8.11 (d, 1H), 8.00-7.91 (m, 6H), 7 79-7.55 (m, 13H), 7.49-7.42 (m, 4H), 7.29-7.09 (m, 1H).

Compound [1] was used as a light emitting device material after sublimation purification at about 300 ° C. under a pressure of 1 × 10 ⁻³ Pa using an oil diffusion pump. The HPLC purity (area% at a measurement wavelength of 254 nm) was 99.25% before sublimation purification and 99.50% after sublimation purification.

Synthesis example 2
Synthesis of compound [2]

  14.0 g of acenaphthylene, 25.0 g of diphenylisobenzofuran and 200 ml of o-xylene were mixed and heated to reflux under a nitrogen stream. After 2 hours, after cooling to room temperature, the solvent was distilled off and 300 mL of ether was added. The resulting precipitate was filtered and vacuum-dried to obtain 27.7 g of intermediate E (yield 71%).

  Next, 27.7 g of intermediate E and 200 mL of acetic acid were mixed, 20 mL of 48% aqueous hydrogen bromide was added, and the mixture was heated to reflux. After 3 hours, the reaction mixture was cooled to room temperature, filtered, and washed with water and methanol. The obtained solid was vacuum-dried to obtain 25.8 g of intermediate F (yield 96%).

  Next, 25.8 g of intermediate F, 11.3 g of N-bromosuccinimide, and 318 mL of chloroform were mixed and heated to reflux. After 1 hour, 3.4 g of N-bromosuccinimide was added, and the mixture was further heated to reflux. Two hours later, after cooling to room temperature, the chloroform solution was washed with water and an aqueous sodium thiosulfate solution. The organic layer was dried over magnesium sulfate, added with 3 g of activated carbon, filtered, and the solvent was distilled off. The obtained solid was recrystallized with 800 mL of butyl acetate, filtered, and then dried under vacuum to obtain 26.9 g of Intermediate G (yield 87%).

Next, 3.00 g of intermediate G, 2.34 g of intermediate B, 31 ml of 1,2-dimethoxyethane, and 6.2 ml of 2.0 M aqueous sodium carbonate solution were mixed and purged with nitrogen. To this mixed solution, 44 mg of bis (triphenylphosphine) palladium dichloride was added and heated to reflux. After 3 hours, after cooling to room temperature, 30 ml of water was added, and the precipitated solid was collected by filtration. The obtained solid was vacuum-dried and then purified by silica gel column chromatography (toluene / hexane = 5: 1), and the eluate was concentrated. To the obtained tan oil, 40 ml of THF and 200 mg of QuadrasilMP (registered trademark) were added and heated under reflux for 1 hour. The solution was cooled to room temperature, filtered through celite, and the solvent was distilled off. Methanol was added to the resulting tan oil and heated to reflux for 1 hour, and the crystallized solid was collected by filtration. The obtained solid was vacuum-dried to obtain 1.52 g (yield 40%) of a yellow solid. The results of ¹ H-NMR analysis of the obtained powder are as follows, and it was confirmed that the yellow crystals obtained above were the compound [2].
¹ H-NMR (CDCl ₃ (δ = ppm)) δ 7.93-7.85 (m, 3H), 7.80-7.55 (m, 18H), 7.52-7.32 (m, 4H), 6.67 (dd, 2H).
Compound [2] was used as a light emitting device material after sublimation purification at about 320 ° C. under a pressure of 1 × 10 ⁻³ Pa using an oil diffusion pump. The HPLC purity (area% at a measurement wavelength of 254 nm) was 99.68% before sublimation purification and 99.70% after sublimation purification.

Example 1
A glass substrate (manufactured by Geomat Co., Ltd., 11Ω / □, sputtered product) on which an ITO transparent conductive film was deposited to 160 nm was cut into 38 × 46 mm and etched. The obtained substrate was ultrasonically cleaned with “Semico Clean 56” (trade name, manufactured by Furuuchi Chemical Co., Ltd.) for 15 minutes and then with ultrapure water. This substrate was subjected to UV-ozone treatment for 1 hour immediately before producing the device, placed in a vacuum deposition apparatus, and evacuated until the degree of vacuum in the apparatus became 5 × 10 ⁻⁴ Pa or less. By the resistance heating method, first, the compound (HI-1) was vapor-deposited as a hole injection material at a thickness of 10 nm, and the compound (HT-1) as a hole-transport material was vapor-deposited at a thickness of 80 nm. Next, the compound [1] of the present invention as a host material and the compound (D-1) as a dopant material were vapor-deposited in a thickness of 30 nm on the light emitting material so that the doping concentration was 3% by weight. Next, the compound (1E-1) was deposited as an electron transport layer to a thickness of 30 nm and laminated.

Next, after depositing the compound (2E-1) as an electron injection layer to a thickness of 1 nm, a deposition rate ratio of a magnesium and silver co-deposition film is magnesium: silver = 10: 1 (= 0.5 nm / s: 0.05 nm / s). Then, a 5 × 5 mm square element was produced by depositing 100 nm as a cathode. The film thickness referred to here is a crystal oscillation type film thickness monitor display value. When this light-emitting device was DC-driven at 10 mA / cm ² , a blue light-emitting device excellent in durability with an external quantum efficiency of 4.3%, a driving voltage of 4.2 V, and a luminance half time of 6100 hours was obtained.

  In addition, (HI-1), (HT-1), (D-1), (1E-1), and (2E-1) are the compounds shown below.

Example 2
A light emitting device was produced in the same manner as in Example 1 except that the compound (H-1) was used as the host material and the compound [2] of the present invention was used as the dopant material. When this light-emitting device was DC-driven at 10 mA / cm ² , a blue light-emitting device having excellent durability with an external quantum efficiency of 5.1%, a driving voltage of 4.6 V, and a luminance half time of 8700 hours was obtained. (H-1) is a compound shown below.

Comparative Examples 1-5
A light emitting device was produced in the same manner as in Example 2 except that the materials described in Table 1 were used as the dopant material. The results are shown in Table 1. In Table 1, (D-2) to (D-5) are the compounds shown below.

Example 3
A glass substrate (manufactured by Geomat Co., Ltd., 11Ω / □, sputtered product) on which an ITO transparent conductive film was deposited to 160 nm was cut into 38 × 46 mm and etched. The obtained substrate was ultrasonically cleaned with “Semico Clean 56” (trade name, manufactured by Furuuchi Chemical Co., Ltd.) for 15 minutes and then with ultrapure water. This substrate was subjected to UV-ozone treatment for 1 hour immediately before producing the device, placed in a vacuum deposition apparatus, and evacuated until the degree of vacuum in the apparatus became 5 × 10 ⁻⁴ Pa or less. By the resistance heating method, first, the compound (HI-1) was vapor-deposited as a hole injection material at a thickness of 10 nm, and the compound (HT-1) as a hole-transport material was vapor-deposited at a thickness of 80 nm. Next, the compound (H-1) as a host material and the compound [2] as a dopant material were vapor-deposited on the light-emitting material to a thickness of 30 nm so that the doping concentration was 3% by weight. Next, the compound (1E-2) was deposited as an electron transport layer to a thickness of 30 nm and laminated.

Next, after depositing the compound (2E-1) as an electron injection layer to a thickness of 1 nm, a deposition rate ratio of a magnesium and silver co-deposition film is magnesium: silver = 10: 1 (= 0.5 nm / s: 0.05 nm / s). Then, a 5 × 5 mm square element was produced by depositing 100 nm as a cathode. When this light-emitting device was DC-driven at 10 mA / cm ² , a blue light-emitting device excellent in durability with an external quantum efficiency of 5.5%, a driving voltage of 3.9 V, and a luminance half-life time of 7800 hours was obtained.
In addition, (1E-2) is a compound shown below.

Examples 4-9
A light emitting device was produced in the same manner as in Example 3 except that the materials described in Table 2 were used as the electron transport layer. The results of each example are shown in Table 2. In addition, (1E-3) to (1E-8) are the compounds shown below.

Comparative Examples 6-10
A light emitting device was produced in the same manner as in Example 3 except that the materials described in Table 2 were used as the dopant material and the electron transport layer. The results are shown in Table 2.

Example 10
A glass substrate (manufactured by Geomat Co., Ltd., 11Ω / □, sputtered product) on which an ITO transparent conductive film was deposited to 160 nm was cut into 38 × 46 mm and etched. The obtained substrate was ultrasonically cleaned with “Semico Clean 56” (trade name, manufactured by Furuuchi Chemical Co., Ltd.) for 15 minutes and then with ultrapure water. This substrate was subjected to UV-ozone treatment for 1 hour immediately before producing the device, placed in a vacuum deposition apparatus, and evacuated until the degree of vacuum in the apparatus became 5 × 10 ⁻⁴ Pa or less. By the resistance heating method, first, the compound (HI-1) was vapor-deposited as a hole injection material at a thickness of 10 nm, and the compound (HT-1) as a hole-transport material was vapor-deposited at a thickness of 80 nm. Next, the compound (H-1) as a host material and the compound [2] as a dopant material were vapor-deposited on the light-emitting material to a thickness of 30 nm so that the doping concentration was 3% by weight. Next, using the compound (1E-2) as the electron transporting material as the electron transporting layer and (2E-1) as the donor compound, the deposition rate ratio of the compounds (1E-2) and (2E-1) is 1: 1 was deposited to a thickness of 30 nm and laminated.

Next, after depositing the compound (2E-1) as an electron injection layer to a thickness of 1 nm, a deposition rate ratio of a magnesium and silver co-deposition film is magnesium: silver = 10: 1 (= 0.5 nm / s: 0.05 nm / s). Then, a 5 × 5 mm square element was produced by depositing 100 nm as a cathode. When this light-emitting device was DC-driven at 10 mA / cm ² , a blue light-emitting device excellent in durability with an external quantum efficiency of 6.1%, a driving voltage of 3.8 V, and a luminance half time of 9100 hours was obtained.

Examples 11-13
A light emitting device was produced in the same manner as in Example 10 except that the materials described in Table 3 were used as the electron transport layer. The results of each example are shown in Table 3.

Comparative Examples 11-15
A light emitting device was produced in the same manner as in Example 10 except that the materials described in Table 3 were used as the dopant material and the electron transport layer. The results are shown in Table 3.

Example 14
A glass substrate (manufactured by Geomat Co., Ltd., 11Ω / □, sputtered product) on which an ITO transparent conductive film was deposited to 160 nm was cut into 38 × 46 mm and etched. The obtained substrate was ultrasonically cleaned with “Semico Clean 56” (trade name, manufactured by Furuuchi Chemical Co., Ltd.) for 15 minutes and then with ultrapure water. This substrate was subjected to UV-ozone treatment for 1 hour immediately before producing the device, placed in a vacuum deposition apparatus, and evacuated until the degree of vacuum in the apparatus became 5 × 10 ⁻⁴ Pa or less. First, the compound (HI-1) was vapor-deposited by 10 nm as a hole injection material by a resistance heating method, and the compound (HT-1) was vapor-deposited by 70 nm as a first hole transport layer. Further, 10 nm of a compound (HT-2) was deposited as a second hole transport layer. Next, the compound (H-1) as a host material and the compound [2] as a dopant material were vapor-deposited on the light-emitting material to a thickness of 30 nm so that the doping concentration was 3% by weight. Next, the compound (1E-1) was deposited as an electron transport layer to a thickness of 30 nm and laminated.

Next, after depositing the compound (2E-1) as an electron injection layer to a thickness of 1 nm, a deposition rate ratio of a magnesium and silver co-deposition film is magnesium: silver = 10: 1 (= 0.5 nm / s: 0.05 nm / s). Then, a 5 × 5 mm square element was produced by depositing 100 nm as a cathode. When this light-emitting device was DC-driven at 10 mA / cm ² , a blue light-emitting device having excellent durability with an external quantum efficiency of 5.3%, a driving voltage of 4.3 V, and a luminance half time of 8200 hours was obtained. In addition, (HT-2) is a compound shown below.

Examples 15-19
A light emitting device was produced in the same manner as in Example 14 except that the materials described in Table 4 were used as the second hole transport layer and the electron transport layer. The results of each example are shown in Table 4. The results of Examples 2 and 7 are also shown again for reference. In addition, (HT-3) and (HT-4) are the compounds shown below.

Comparative Examples 16-25
A light emitting device was produced in the same manner as in Example 14 except that the materials described in Table 4 were used as the dopant material and the electron transport layer. The results are shown in Table 4.

Example 20
A glass substrate (manufactured by Geomat Co., Ltd., 11Ω / □, sputtered product) on which an ITO transparent conductive film was deposited to 160 nm was cut into 38 × 46 mm and etched. The obtained substrate was ultrasonically cleaned with “Semico Clean 56” (trade name, manufactured by Furuuchi Chemical Co., Ltd.) for 15 minutes and then with ultrapure water. This substrate was subjected to UV-ozone treatment for 1 hour immediately before producing the device, placed in a vacuum deposition apparatus, and evacuated until the degree of vacuum in the apparatus became 5 × 10 ⁻⁴ Pa or less. By the resistance heating method, first, the compound (HI-1) was vapor-deposited as a hole injection material at a thickness of 10 nm, and the compound (HT-1) as a hole-transport material was vapor-deposited at a thickness of 80 nm. Next, the compound (H-1) as a host material and the compound (D-3) as a dopant material were vapor-deposited to a thickness of 30 nm on the light emitting material so that the doping concentration was 3% by weight. Next, the compound [1] of the present invention was deposited as an electron transport layer to a thickness of 30 nm and laminated.

Next, after depositing the compound (2E-1) as an electron injection layer to a thickness of 1 nm, a deposition rate ratio of a magnesium and silver co-deposition film is magnesium: silver = 10: 1 (= 0.5 nm / s: 0.05 nm / s). Then, a 5 × 5 mm square element was produced by depositing 100 nm as a cathode. The film thickness referred to here is a crystal oscillation type film thickness monitor display value. When this light-emitting element was DC-driven at 10 mA / cm ² , a blue light-emitting element excellent in durability with an external quantum efficiency of 4.6%, a driving voltage of 4.5 V, and a luminance half-time of 5600 hours was obtained.

Example 21
A light emitting device was produced in the same manner as in Example 20 except that the materials described in Table 5 were used as the electron transport layer. The results are shown in Table 5.

Examples 22-23
As the electron transport layer, the compounds listed in Table 5 were used as the electron transport material, and (2E-1) was used as the donor compound, and the layers were vapor deposited to a thickness of 30 nm so that the deposition rate ratio was 1: 1. A light emitting device was fabricated in the same manner as in Example 21 except for the above. The results are shown in Table 5.

Comparative Examples 26-29
A light emitting device was produced in the same manner as in Example 20 except that the materials described in Table 5 were used as the electron transport layer. The results are shown in Table 5.

Comparative Examples 30-33
A light emitting device was produced in the same manner as in Example 22 except that the materials described in Table 5 were used as the electron transport layer. The results are shown in Table 5.

Example 24
A glass substrate (manufactured by Geomat Co., Ltd., 11Ω / □, sputtered product) on which an ITO transparent conductive film was deposited to 160 nm was cut into 38 × 46 mm and etched. The obtained substrate was ultrasonically cleaned with “Semico Clean 56” (trade name, manufactured by Furuuchi Chemical Co., Ltd.) for 15 minutes and then with ultrapure water. This substrate was subjected to UV-ozone treatment for 1 hour immediately before producing the device, placed in a vacuum deposition apparatus, and evacuated until the degree of vacuum in the apparatus became 5 × 10 ⁻⁴ Pa or less. By the resistance heating method, first, the compound (HI-1) was vapor-deposited as a hole injection material at a thickness of 10 nm, and the compound (HT-1) as a hole-transport material was vapor-deposited at a thickness of 80 nm. This hole transport layer is shown in Table 6 as the first hole transport layer. Next, a compound (H-2) as a host material and a compound (D-6) as a dopant material were vapor-deposited on the light-emitting material to a thickness of 30 nm so that the doping concentration was 10% by weight. Next, Compound [2] was deposited as an electron transport layer to a thickness of 25 nm and laminated.

Next, after depositing the compound (2E-1) as an electron injection layer to a thickness of 1 nm, a deposition rate ratio of a magnesium and silver co-deposition film is magnesium: silver = 10: 1 (= 0.5 nm / s: 0.05 nm / s). Then, a 5 × 5 mm square element was produced by depositing 100 nm as a cathode. The characteristics of this green light emitting device at 4000 cd / m ² were an external quantum efficiency of 12.1% and a driving voltage of 4.5V. When the initial luminance was set to 4000 cd / m ² and driven at a constant current, the luminance half time was 7000 hours. (H-2) and (D-6) are the compounds shown below.

Example 25
A glass substrate (manufactured by Geomat Co., Ltd., 11Ω / □, sputtered product) on which an ITO transparent conductive film was deposited to 160 nm was cut into 38 × 46 mm and etched. The obtained substrate was ultrasonically cleaned with “Semico Clean 56” (trade name, manufactured by Furuuchi Chemical Co., Ltd.) for 15 minutes and then with ultrapure water. This substrate was subjected to UV-ozone treatment for 1 hour immediately before producing the device, placed in a vacuum deposition apparatus, and evacuated until the degree of vacuum in the apparatus became 5 × 10 ⁻⁴ Pa or less. First, the compound (HI-1) was vapor-deposited by 10 nm as a hole injection material by a resistance heating method, and the compound (HT-1) was vapor-deposited by 70 nm as a first hole transport layer. Further, 10 nm of a compound (HT-2) was deposited as a second hole transport layer. Next, a compound (H-2) as a host material and a compound (D-4) as a dopant material were vapor-deposited in a thickness of 30 nm on the light emitting material so that the doping concentration was 10 wt%. Next, Compound [2] was deposited as an electron transport layer to a thickness of 30 nm and laminated.

Next, after depositing the compound (2E-1) as an electron injection layer to a thickness of 1 nm, a deposition rate ratio of a magnesium and silver co-deposition film is magnesium: silver = 10: 1 (= 0.5 nm / s: 0.05 nm / s). Then, a 5 × 5 mm square element was produced by depositing 100 nm as a cathode. The green light emitting device had characteristics of 4000 cd / m ² when the external quantum efficiency was 13.8% and the driving voltage was 4.2V. When the initial luminance was set to 4000 cd / m ² and driving at constant current was performed, the luminance half time was 7600 hours.

Examples 26-27
A light emitting device was produced in the same manner as in Example 25 except that the materials described in Table 6 were used as the second hole transport layer. The results of each example are shown in Table 6.

Comparative Examples 34-37
A light emitting device was produced in the same manner as in Example 25 except that the materials described in Table 6 were used as the electron transport layer. The results are shown in Table 6.

Claims (14)

A light emitting device material comprising a compound represented by the following general formula (1).

(In the formula, Ar ¹ is an aromatic hydrocarbon group having three or more condensed rings, and is selected from a group other than a phenanthryl group, a fluorenyl group, and a triphenylenyl group. L ¹ is a single bond, an arylene group, or a hetero group. An arylene group, Z is a group represented by the following general formula (2), n ¹ is an integer of 1 or more, and when n ¹ is 2 or more, L ¹ and Z are the same or different. May be good.)

(Wherein R ^{1 to} R ⁸ may be the same or different and are each hydrogen, halogen, alkyl group, cycloalkyl group, heterocyclic group, alkenyl group, cycloalkenyl group, alkynyl group, alkoxy group, alkylthio group. , Aryl ether group, aryl thioether group, aryl group, heteroaryl group, cyano group, carbonyl group, carboxyl group, oxycarbonyl group, carbamoyl group, silyl group, and a condensed ring formed between adjacent substituents (However, it is linked to L ¹ at any one of R ^{1 to} R ⁸ ) The light emitting device material according to claim 1, wherein Ar ¹ is an aromatic hydrocarbon group containing a fluoranthene skeleton. The light emitting device material according to claim 1, wherein Ar ¹ is represented by the following general formula (3).

(Wherein R ^{9 to} R ²⁰ may be the same or different and are each hydrogen, halogen, alkyl group, cycloalkyl group, heterocyclic group, alkenyl group, cycloalkenyl group, alkynyl group, alkoxy group, alkylthio group. , Aryl ether group, aryl thioether group, aryl group, heteroaryl group, cyano group, carbonyl group, carboxyl group, oxycarbonyl group, carbamoyl group, amino group and silyl group, provided that R ^{9 to} R ²⁰ are selected. Are connected to L ¹ at n ¹ positions. A light-emitting element in which an organic layer is present between an anode and a cathode and emits light by electric energy, and the light-emitting element contains the light-emitting element material according to claim 1 in the organic layer. The light emitting device according to claim 4, wherein the organic layer includes a light emitting layer, and the light emitting layer includes the light emitting device material according to claim 1. The light emitting device according to claim 5, wherein the light emitting layer has a host material and a dopant material, and the dopant material is the light emitting device material according to claim 1. The light emitting device according to claim 4, wherein the organic layer includes an electron transport layer, and the electron transport layer includes the light emitting device material according to claim 1. The organic layer is a light emitting device including a light emitting layer and an electron transport layer, the dopant material of the light emitting layer is the light emitting device material according to any one of claims 1 to 3, and the electron transport layer is represented by the following general formula (4) The light emitting element of Claim 6 containing the compound represented by this.

(R ^{21 to} R ³⁰ may be the same as or different from each other, hydrogen, halogen, alkyl group, cycloalkyl group, heterocyclic group, alkenyl group, cycloalkenyl group, alkynyl group, alkoxy group, alkylthio group, aryl ether group. , An arylthioether group, an aryl group, a heteroaryl group, a carbonyl group, a carboxyl group, an oxycarbonyl group, a carbamoyl group, an amino group, a silyl group, and —P (═O) R ³¹ R ^{32, wherein} R ^{21 to} R ³⁰ are linked to L ² at n ² positions, L ² is a single bond, a substituted or unsubstituted arylene group, or a substituted or unsubstituted heteroarylene group, and Ar ² is an electron accepting group. An aromatic heterocyclic group containing nitrogen, n ² is an integer of 1 or more, and when n ² is 2 or more, L ² And Ar ² may be the same or different. The light emitting device according to claim 8, wherein, in the general formula (4), any one of the following conditions (a) to (c) is satisfied.
(A) n ² is 1, linked to L ² at the position of R ²¹ , and R ²⁶ is an aryl group or a heteroaryl group.
(B) n ² is 1, linked to L ² at the position of R ²¹ , R ²³ is an aryl group or heteroaryl group, and R ²⁶ , R ²⁷ , and R ²⁸ are all hydrogen atoms .
(C) n ² is 1, linked to L ² at the position of R ²¹ , R ²³ is an aryl group or a heteroaryl group, and R ²⁷ is an alkyl group, an aryl group, or a heteroaryl group. The organic layer is a light emitting device including a light emitting layer and an electron transport layer, the dopant material of the light emitting layer is the light emitting device material according to any one of claims 1 to 3, and the electron transport layer is represented by the following general formula (5 The light emitting element of Claim 6 containing the compound represented by (6).

(R ³³ to R ⁴⁰ may be the same or different and each hydrogen, halogen, alkyl group, cycloalkyl group, heterocyclic group, alkenyl group, cycloalkenyl group, alkynyl group, alkoxy group, alkylthio group, aryl ether group , An arylthioether group, an aryl group, a carbonyl group, a carboxyl group, a carbamoyl group, an amino group, a silyl group, and —P (═O) R ⁴¹ R ^42, wherein R ⁴¹ and R ⁴² are an aryl group or hetero R ⁴¹ and R ⁴² may be condensed to form a ring, provided that at least one of R ^{33 to} R ⁴⁰ itself has a three-dimensional structure, or It has a three-dimensional structure due to steric repulsion with the phenanthroline skeleton or adjacent substituents. )

(R ^{43 to} R ⁵⁰ may be the same as or different from each other, hydrogen, halogen, alkyl group, cycloalkyl group, heterocyclic group, alkenyl group, cycloalkenyl group, alkynyl group, alkoxy group, alkylthio group, aryl ether group. , An arylthioether group, an aryl group, a carbonyl group, a carboxyl group, a carbamoyl group, an amino group, a silyl group, and —P (═O) R ⁵¹ R ^52. R ⁵¹ and R ⁵² are an aryl group or a hetero group. R ⁵¹ and R ⁵² may be condensed to form a ring, provided that n ³ phenanthroline skeletons are linked to X at at least one of R ^{43 to} R ^50. .n ³ is an integer of 2 or more .X is to connect the single bond or phenanthroline skeleton A consolidated unit.) The organic layer is a light emitting device including a light emitting layer and an electron transport layer, the dopant material of the light emitting layer is the light emitting device material according to any one of claims 1 to 3, and the electron transport layer is represented by the following general formula (7 The light emitting element of Claim 6 containing the compound represented by this.

(In the formula, Ar ³ represents an aryl group or a heteroaryl group, and Y is represented by the following general formula (8). L ³ is a single bond, an arylene group or a heteroarylene group. N ⁴ is 1 or 2 When n ⁴ is 2, two Ys may be the same or different.)

(In the formula, each of ring A and ring B represents a benzene ring, a condensed aromatic hydrocarbon ring, a monocyclic aromatic heterocyclic ring, or a condensed aromatic heterocyclic ring, provided that at least ring A and ring B constitute at least One atom is an electron-accepting nitrogen, the substituent when ring A and ring B are substituted, and R ⁵³ are an alkyl group, a cycloalkyl group, a heterocyclic group, an alkenyl group, a cycloalkenyl group, respectively. , Alkynyl group, alkoxy group, alkylthio group, aryl ether group, aryl thioether group, aryl group, heteroaryl group, halogen, carbonyl group, carboxyl group, oxycarbonyl group, carbamoyl group and —P (═O) R ⁵⁴ R ⁵⁵ R ⁵³ may be hydrogen, R ⁵⁴ and R ⁵⁵ may be an aryl group or a heteroaryl. R ⁵⁴ and R ⁵⁵ may be condensed to form a ring, but linked to L ³ at any position of R ⁵³ , ring A and ring B. n ⁴ is In the case of 2, the position at which two Y are linked to L ³ may be the same or different. The light-emitting element according to claim 11, wherein in the general formula (7), Ar ³ is a group containing a fluoranthene skeleton. The light emitting device according to any one of claims 6 to 12, further comprising a hole transport layer between the anode and the cathode, wherein the hole transport layer contains a material having a carbazole skeleton. The light-emitting element according to claim 13, wherein the material having the carbazole skeleton is a carbazole multimer.