JPWO2017104767A1 - Compound for organic electroluminescent device and organic electroluminescent device using the same - Google Patents

Abstract

Provided are a compound for an organic electroluminescence device exhibiting high emission efficiency and blue light emission with high color purity and high durability when used as a constituent material of an organic electroluminescence device, and an organic electroluminescence device using the same. The purpose is to do. By incorporating a pyrene compound having a specific substituent of the present invention into an organic electroluminescent element, an organic electroluminescent element exhibiting blue light emission with high luminous efficiency and high color purity and high durability is realized. It becomes possible to do. [Selection] Figure 1

Description

  The present invention relates to a compound for an organic electroluminescent device and an organic electroluminescent device using the same.

  The organic electroluminescent element is composed of an anode, a cathode, and one or a plurality of layers containing an organic compound sandwiched between the anode and the cathode. By injecting holes and electrons from each electrode, excitons of the light-emitting organic compound contained in the organic compound layer are generated, and the organic electroluminescence device emits light when the excitons return to the ground state.

  Organic electroluminescent elements are expected to be a technology for realizing light-emitting devices with low power consumption, various emission colors, high-speed response, thin and lightweight, and are actively researched.

  However, in order to promote the practical application of organic electroluminescent devices to displays, etc., the current luminous efficiency and continuous drive life of the devices are not sufficient in practice, and further high-efficiency light emission and longer life are required. Yes. Further, when considering application to a full color display or the like, light emission of blue, green, and red with high color purity is required, but these problems have not been sufficiently solved yet.

  There are a wide variety of organic compounds as constituent materials for organic electroluminescent elements, and various organic materials have been developed as the organic compounds. In order to solve the above problems, for example, compounds having a pyrene skeleton, A compound having a fluorene skeleton has been proposed. Patent Documents 1 and 2 report examples in which an asymmetric pyrene derivative is used as a light emitting layer host material of an organic electroluminescent element. Patent Documents 3 and 4 report examples in which fluorene and a ring-condensed fluorene derivative are used as a light emitting layer host material or a light emitting auxiliary layer material of an organic electroluminescence device. Patent Documents 5 to 8 report examples in which a compound having a pyrene skeleton and a fluorene skeleton or a ring-condensed fluorene skeleton is used as a light emitting layer host material or a dopant of an organic electroluminescence device.

Japanese Patent No. 4705914 Japanese Patent No. 5374486 Japanese Patent No. 5233228 International Publication No. 2015/005440 JP 2013-173771 A JP 2013-157552 A International Publication No. 2011/0776889 International Publication No. 2011/0881403

  The present invention relates to a compound for organic electroluminescence device exhibiting blue emission and high durability with high luminous efficiency and color purity when used as a constituent material of an organic electroluminescence device, and an organic electroluminescence device using this compound. The purpose is to provide.

  In order to achieve the above object, the present invention provides a compound for an organic electroluminescent device, which is represented by any one of the following general formulas (1) to (3).

（一般式（１）乃至（３）において、
Ｘ^１およびＸ^２は、それぞれ独立に、単結合、または置換もしくは無置換の炭素数６〜２０のアリーレン基であり、Ｘ^１は、位置ａ，ｂ，ｃ，ｄの何れかと結合し、Ｘ^２は、位置ｅ，ｆ，ｇ，ｈの何れかと結合する。
Ａｒは、置換もしくは無置換の炭素数６〜２０のアリール基である。
Ｒ^１乃至Ｒ^４は、それぞれ独立に、置換もしくは無置換の炭素数１〜１０のアルキル基、または置換もしくは無置換の炭素数６〜１２のアリール基である。
ただし、一般式（１）において、位置ｂと結合するＸ^１は、置換もしくは無置換の炭素数６〜２０のアリーレン基である。）

(In the general formulas (1) to (3),
X ¹ and X ² are each independently a single bond or a substituted or unsubstituted arylene group having 6 to 20 carbon atoms, X ¹ is bonded to any one of positions a, b, c and d; ² is coupled to any of the positions e, f, g, and h.
Ar is a substituted or unsubstituted aryl group having 6 to 20 carbon atoms.
R ^{1 to} R ⁴ are each independently a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 12 carbon atoms.
However, in General formula (1), X < ¹ > couple | bonded with the position b is a substituted or unsubstituted C6-C20 arylene group. )

The compound for organic electroluminescence device represented by any one of the general formulas (1) to (3) according to the present invention is dibenzo [a, c] fluorene at the 1-position, or 1-position and 6-position of the pyrene ring. It has a structure. A compound in which a dibenzo [a, c] fluorenyl group is substituted on a pyrene ring directly or via a linking group has the following two properties as compared with a pyrene derivative not containing a dibenzo [a, c] fluorene structure.
1. The steric hindrance around the pyrene ring is large.
2. The ionization potential is small.

  The large steric hindrance around the pyrene ring gives the compound a low molecular association property in order to suppress the association of the same or different molecules with the pyrene ring. For this reason, the production | generation of the excimer or exciplex by molecular association which becomes the cause of the luminous efficiency of an organic electroluminescent element and the fall of color purity can be reduced. Therefore, when the pyrene derivative according to the present invention is used as a material for an organic electroluminescence device, it is possible to realize an organic electroluminescence device with higher efficiency and high color purity.

  In addition, the pyrene derivative according to the present invention has an ionization potential smaller by 0.1 eV or more than a pyrene derivative not containing a dibenzo [a, c] fluorene structure. For this reason, when an organic electroluminescence device is generally formed by laminating a hole injection layer or hole transport layer such as arylamine whose ionization potential is smaller than that of the pyrene derivative, a hole injection barrier from the hole injection layer or hole transport layer is used. Therefore, the driving voltage can be reduced.

  The compounds represented by the general formulas (2) and (3) are 1,6-diaryl having a dibenzo [a, c] fluorene structure having a large steric hindrance at the 1-position or 1-position and 6-position of the pyrene ring. Since it is a pyrene derivative, molecular asymmetry and steric hindrance are large. For this reason, it is possible to form a stable amorphous film with low molecular crystallinity. An organic electroluminescent element containing such a compound for organic electroluminescent element can achieve high durability, that is, a long driving life.

In addition, in the general formula (1), when X ¹ is an arylene group, a stable amorphous film with low molecular crystallinity can be formed due to a decrease in planarity and an increase in flexibility of the whole molecule.

However, in the general formula (1), when X ¹ is a single bond, since there are few bonds that can freely rotate, the number of conformations that the molecule can take tends to be small, and the crystallinity tends to be high. In addition, when X ¹ is bonded to position b, the crystallinity is higher due to the high linearity of the molecule. However, when X ¹ is bonded to any ^one of positions a, c, and d, crystallization is suppressed and a stable amorphous film is formed because the molecular flexibility is greater than when bonding to position b. can do.

  Therefore, the pyrene derivative represented by the general formula (1) according to the present invention has a low molecular crystallinity and can form a stable amorphous film. It is possible to realize an organic electroluminescent element having high durability.

In the compound for organic electroluminescence device according to the present invention, in the general formulas (1) to (3), X ¹ and X ² are each independently a single bond, substituted or unsubstituted phenylene group, naphthylene group. Or a biphenylene group.

When X ¹ and X ² are the above substituents, the effect of reducing the ionization potential of the compound by substitution with dibenzo [a, c] fluorene is high, and it has an energy gap suitable for blue light emission. Therefore, it is possible to realize blue light emission with high color purity and high light emission efficiency.

  In the compound for organic electroluminescent elements according to the present invention, in general formula (2), Ar is preferably a substituted or unsubstituted phenylene group, naphthylene group, or biphenylene group.

  In the case where Ar is the above substituent, since the compound has high thermal stability, high solubility, and easy synthesis, it is possible to produce a compound for an organic electroluminescence device with few impurities. In addition, it is possible to obtain an organic electroluminescent element exhibiting high luminous efficiency and high durability.

  In the organic electroluminescence device in which one or more organic layers are sandwiched between a pair of electrodes including an anode and a cathode, at least one of the organic layers is represented by the following general formulas (1) to (3). It is preferable to contain the compound A represented by any of 1) as a component of a single or mixture.

（一般式（１）乃至（３）において、
Ｘ^１およびＸ^２は、それぞれ独立に、単結合、または置換もしくは無置換の炭素数６〜２０のアリーレン基であり、Ｘ^１は、位置ａ，ｂ，ｃ，ｄの何れかと結合し、Ｘ^２は、位置ｅ，ｆ，ｇ，ｈの何れかと結合する。
Ａｒは、置換もしくは無置換の炭素数６〜２０のアリール基である。
Ｒ^１乃至Ｒ^４は、それぞれ独立に、置換もしくは無置換の炭素数１〜１０のアルキル基、または置換もしくは無置換の炭素数６〜１２のアリール基である。
ただし、一般式（１）において、位置ｂと結合するＸ^１は、置換もしくは無置換の炭素数６〜２０のアリーレン基である。）

(In the general formulas (1) to (3),
X ¹ and X ² are each independently a single bond or a substituted or unsubstituted arylene group having 6 to 20 carbon atoms, X ¹ is bonded to any one of positions a, b, c and d; ² is coupled to any of the positions e, f, g, and h.
Ar is a substituted or unsubstituted aryl group having 6 to 20 carbon atoms.
R ^{1 to} R ⁴ are each independently a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 12 carbon atoms.
However, in General formula (1), X < ¹ > couple | bonded with the position b is a substituted or unsubstituted C6-C20 arylene group. )

  According to such an organic electroluminescent element, since the compound A represented by any one of the general formulas (1) to (3) is included, high luminous efficiency, color purity, and durability can be obtained.

  In the organic electroluminescent device according to the present invention, the organic layer preferably has a light emitting layer, and the light emitting layer preferably contains the compound A.

  In the organic electroluminescent element according to the present invention, the light emitting layer preferably includes a host material and a dopant, and the host material preferably includes the compound A.

  According to such an organic electroluminescent device, it is possible to reduce the generation of excimers or exciplexes due to molecular association, so that high luminous efficiency and color purity can be obtained. In addition, since the hole injection barrier from the hole transport layer to the light emitting layer is small, the driving voltage can be reduced.

  Moreover, the organic electroluminescent element concerning this invention WHEREIN: It is preferable that the said dopant contains the compound B represented by following General formula (4).

（一般式（４）において、
Ｙ^１は、置換もしくは無置換の炭素数６〜１２のアリール基、または置換もしくは無置換の環構成元素数５〜１２の含窒素芳香族複素環基である。
Ｙ^２乃至Ｙ^４は、それぞれ独立に、水素、置換もしくは無置換の炭素数６〜１２のアリール基、または置換もしくは無置換の環構成元素数５〜１２の含窒素芳香族複素環基である。
ただし、Ｙ^１乃至Ｙ^４の少なくとも１つは、置換もしくは無置換の環構成元素数５〜１２の含窒素芳香族複素環基、または、シアノ基もしくはトリフルオロメチル基が１つ以上置換した炭素数６〜１２のアリール基または環構成元素数５〜１２の含窒素芳香族複素環基である。

(In general formula (4),
Y ¹ is a substituted or unsubstituted aryl group having 6 to 12 carbon atoms, or a substituted or unsubstituted nitrogen-containing aromatic heterocyclic group having 5 to 12 ring constituent elements.
Y ^{2 to} Y ⁴ are each independently hydrogen, a substituted or unsubstituted aryl group having 6 to 12 carbon atoms, or a substituted or unsubstituted nitrogen-containing aromatic heterocyclic group having 5 to 12 ring constituent elements. .
However, at least one of Y ^{1 to} Y ⁴ is a carbon atom substituted with one or more substituted or unsubstituted nitrogen-containing aromatic heterocyclic groups having 5 to 12 ring constituent elements, or a cyano group or a trifluoromethyl group. It is an aryl group of several 6 to 12 or a nitrogen-containing aromatic heterocyclic group having 5 to 12 ring constituent elements.

  Benzo [k] fluoranthene represented by the general formula (4) is an aryl group or nitrogen-containing group in which at least one nitrogen-containing aromatic heterocyclic group, or one or more cyano group or trifluoromethyl group is substituted in the molecule. Since it has an aromatic heterocyclic group, it has an electron affinity that is about 0.1 to 0.2 eV higher than that of benzo [k] fluoranthene that does not have the substituent, and exhibits a strong electron accepting property.

  Therefore, when benzo [k] fluoranthene represented by the general formula (4) is used as the dopant of the organic electroluminescent device, most of the electrons injected into the device are captured by the dopant on the cathode side of the light emitting layer. .

  In order to obtain high luminous efficiency as an organic electroluminescent device, it is necessary that recombination of both the hole and electron carriers in the dopant occurs efficiently. For this purpose, the dopant sufficiently captures the carrier, It is important that the carriers are sufficiently supplied to the dopant in the light emitting layer.

  That is, in the organic electroluminescent device using the dopant, it is necessary that the holes injected into the device are transported without delay to the cathode side of the light emitting layer where the dopant capturing electrons is present.

  The ionization potential of anthracene and pyrene derivatives, which are general host materials, is about 0.5 eV greater than that of diarylamine derivatives, which are general hole transport materials. In organic electroluminescent devices using these materials, the hole injection barrier from the hole transport layer to the light emitting layer is large, and the holes tend to accumulate at the interface between the hole transport layer and the light emitting layer (the anode side of the light emitting layer). Therefore, when a dopant having a high electron accepting property is used, holes cannot be sufficiently supplied to the dopant, and high luminous efficiency cannot be obtained.

  Since the pyrene derivative of the present invention has an ionization potential smaller by 0.1 eV or more than a pyrene derivative not containing a dibenzo [a, c] fluorene structure, a hole transport layer such as diarylamine is used as a host material of the light-emitting layer. When an organic electroluminescent element is formed by laminating the layers, since the hole injection barrier from the hole transport layer to the light emitting layer is small, holes can be sufficiently supplied to the light emitting layer.

  Therefore, when the pyrene derivative represented by any one of the general formulas (1) to (3) is used as a host material and the benzo [k] fluoranthene represented by the general formula (4) is used as a dopant, the efficiency of the dopant is improved. Since good hole-electron recombination occurs, an organic electroluminescent element with high luminous efficiency can be realized.

  Moreover, the organic electroluminescent element concerning this invention WHEREIN: It is preferable that the said organic layer has a hole injection layer, and the said hole injection layer contains the said compound A and an electron acceptor compound.

  The pyrene derivative of the present invention has an ionization potential smaller by 0.1 eV or more than a pyrene derivative not containing a dibenzo [a, c] fluorene structure. Therefore, when an organic electroluminescence device is formed by stacking the compound as a hole injection layer on an anode having a low work function, the hole injection barrier from the anode is small, and there is sufficient hole in the adjacent organic layer and the light emitting layer. Can be supplied. That is, it is possible to realize an organic electroluminescent element with high luminous efficiency and low driving voltage.

  Further, the compound represented by any one of the general formulas (1) to (3) of the present invention has low molecular crystallinity, and can form a stable amorphous mixed layer with the electron acceptor compound. In addition, it is possible to realize an organic electroluminescent element with higher durability.

  According to the organic electroluminescent element compound of the present invention, it is possible to obtain an organic electroluminescent element exhibiting blue light emission with high luminous efficiency and high color purity and high durability.

It is a schematic cross section which shows an example of the organic electroluminescent element concerning this embodiment. 1 is a diagram showing a ¹ HNMR spectrum of a compound (11) of the present invention of Synthesis Example 1. FIG. It is a figure which shows the ¹³ CNMR spectrum of the compound (11) of this invention of the synthesis example 1. ¹ is a diagram showing a ¹ HNMR spectrum of a compound (12) of the present invention in Synthesis Example 2. FIG. It is a figure which shows the ¹³ CNMR spectrum of the compound (12) of this invention of the synthesis example 2. 4 is a diagram showing a ¹ HNMR spectrum of a compound (13) of the present invention in Synthesis Example 3. FIG. It is a figure which shows the ¹³ CNMR spectrum of the compound (13) of this invention of the synthesis example 3. It shows The ¹ HNMR spectrum of the compound of the present invention Synthesis Example 4 (14). It is a figure which shows the ¹³ CNMR spectrum of the compound (14) of this invention of the synthesis example 4. 6 is a diagram showing a ¹ HNMR spectrum of a compound (15) of the present invention in Synthesis Example 5. FIG. It is a figure which shows the ¹³ CNMR spectrum of the compound (15) of this invention of the synthesis example 5.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings as necessary. In the drawings, the same elements are denoted by the same reference numerals, and redundant description is omitted. Further, the positional relationship such as up, down, left and right is based on the positional relationship shown in the drawings unless otherwise specified. Further, the dimensional ratios in the drawings are not limited to the illustrated ratios.

(Compound for organic electroluminescence device)
The compound for organic electroluminescent elements according to a preferred embodiment of the present invention is a pyrene compound having a specific structure represented by any one of the following general formulas (1) to (3).

（一般式（１）乃至（３）において、
Ｘ^１およびＸ^２は、それぞれ独立に、単結合、または置換もしくは無置換の炭素数６〜２０のアリーレン基であり、Ｘ^１は、位置ａ，ｂ，ｃ，ｄの何れかと結合し、Ｘ^２は、位置ｅ，ｆ，ｇ，ｈの何れかと結合する。
Ａｒは、置換もしくは無置換の炭素数６〜２０のアリール基である。
Ｒ^１乃至Ｒ^４は、それぞれ独立に、置換もしくは無置換の炭素数１〜１０のアルキル基、または置換もしくは無置換の炭素数６〜１２のアリール基である。
ただし、一般式（１）において、位置ｂと結合するＸ^１は、置換もしくは無置換の炭素数６〜２０のアリーレン基である。）

(In the general formulas (1) to (3),
X ¹ and X ² are each independently a single bond or a substituted or unsubstituted arylene group having 6 to 20 carbon atoms, X ¹ is bonded to any one of positions a, b, c and d; ² is coupled to any of the positions e, f, g, and h.
Ar is a substituted or unsubstituted aryl group having 6 to 20 carbon atoms.
R ^{1 to} R ⁴ are each independently a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 12 carbon atoms.
However, in General formula (1), X < ¹ > couple | bonded with the position b is a substituted or unsubstituted C6-C20 arylene group. )

In the general formulas (1) to (3), X ¹ and X ² are each independently a single bond or a substituted or unsubstituted arylene group having 6 to 20 carbon atoms.
Specific examples of the arylene group include a phenylene group, a naphthylene group, a biphenylene group, a fluorenylene group, a benzofluorylene group, a phenanthrylene group, an anthracenylene group, a pyrenylene group, and a terphenylene group.

In the general formulas (1) to (3), X ¹ and X ² are each independently preferably a single bond, a substituted or unsubstituted phenylene group, a naphthylene group, or a biphenylene group. When X ¹ and X ² are the above substituents, the effect of reducing the ionization potential of the compound by substitution with dibenzo [a, c] fluorene is high, and it has an energy gap suitable for blue light emission. Therefore, it is possible to realize blue light emission with higher color purity and high light emission efficiency.

The arylene group may be further substituted with a substituent, and examples of such a substituent include an aryl group, an alkyl group, an alkoxy group, an aryloxy group, a halogeno group, and a silyl group. A plurality of these substituents may be present, and adjacent ones may form a saturated or unsaturated cyclic structure.
Among these substituents, an aryl group and an alkyl group are preferable from the viewpoint of stability of the compound and the organic electroluminescent device, and a phenyl group, a naphthyl group, a biphenylyl group, a methyl group, an ethyl group, a propyl group, and a butyl group are more preferable. preferable.

In the general formulas (1) to (3), X ¹ is bonded to any ^one of the positions a, b, c, and d, and X ² is bonded to any one of the positions e, f, g, and h. That is, dibenzo [a, c] fluorene is bonded to the 1-position or 6-position of the pyrene ring directly or via an arylene group at any position of the 9-12th positions. The compound having such a structure has a small ionization potential as compared with a compound bonded at any one of positions 1 to 8 and 13 of dibenzo [a, c] fluorene. When the dopant and the light emitting layer having high electron accepting properties are formed, it is possible to obtain high light emission efficiency. In addition, a compound for an organic electroluminescence device that is easy to synthesize and has few impurities can be manufactured. It is more preferable that X ¹ is coupled to position b and X ² is coupled to position f from the viewpoint of lowering voltage and increasing efficiency.

In General formula (2), Ar is a substituted or unsubstituted aryl group having 6 to 20 carbon atoms.
Specific examples of the aryl group include a phenyl group, a naphthyl group, a biphenylyl group, a fluorenyl group, a benzofluorenyl group, a phenanthryl group, an anthracenyl group, a pyrenyl group, and a terphenyl group.

  In the general formula (2), Ar is preferably a substituted or unsubstituted phenyl group, naphthyl group, or biphenylyl group.

  In the case where Ar is the above substituent, since the compound has high thermal stability, high solubility, and easy synthesis, it is possible to produce a compound for an organic electroluminescence device with few impurities. In addition, it is possible to obtain an organic electroluminescent element exhibiting high luminous efficiency and high durability.

The aryl group may be further substituted with a substituent. Examples of such a substituent include an aryl group, an alkyl group, an alkoxy group, an aryloxy group, a halogeno group, and a silyl group. A plurality of these substituents may be present, and adjacent ones may form a saturated or unsaturated cyclic structure.
Among these substituents, an aryl group and an alkyl group are preferable from the viewpoint of stability of the compound and the organic electroluminescent device, and a phenyl group, a naphthyl group, a methyl group, an ethyl group, a propyl group, and a butyl group are more preferable.

In General Formulas (1) to (3), R ^{1 to} R ⁴ are each independently a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 12 carbon atoms. It is.
R ^{1 to} R ⁴ are preferably a methyl group, an ethyl group, a propyl group, a butyl group, a phenyl group, a naphthyl group, or a biphenylyl group from the viewpoint of the stability of the compound and the ease of synthesis, and a methyl group, a phenyl group, A biphenylyl group is more preferred. In addition, when R ^{1 to} R ⁴ are each independently a phenyl group, a naphthyl group or a phenanthryl group, R ¹ and R ² and R ³ and R ⁴ may combine to form a cyclic structure. Good.

  The alkyl group may be further substituted with a substituent, and examples of such a substituent include an alkoxy group, an aryloxy group, and a silyl group.

The aryl group may be further substituted with a substituent, and examples of such a substituent include an alkyl group, an alkoxy group, an aryloxy group, and a silyl group.
Among these substituents, an alkyl group is preferable from the viewpoint of stability of the compound and the organic electroluminescent device, and a methyl group, an ethyl group, a propyl group, and a butyl group are more preferable.

  Although there is no limitation in particular about the molecular weight of the compound concerning this embodiment, It is preferable that molecular weight is 1300 or less when an element preparation process is considered. This is because a compound having a molecular weight of 1300 or more is difficult to synthesize due to a decrease in solubility, and it is difficult to produce an organic electroluminescent device by a coating process. Further, even when an organic electroluminescent element is produced by a vapor deposition process, the vapor deposition temperature becomes high, which may cause decomposition of the material.

(Specific examples of compounds for organic electroluminescence devices)
As preferable examples of the compound for organic electroluminescence device represented by the general formulas (1) to (3) according to the present embodiment, the following formulas (I-1) to (I-27), (II-1) The compounds represented by (II-28) and (III-1) to (III-17) are mentioned.

(Organic electroluminescence device)
FIG. 1 is a schematic cross-sectional view showing an example of an organic electroluminescent element according to this embodiment. The organic electroluminescent element 1 shown in FIG. 1 includes a hole injection layer 4, a hole transport layer 5, a light emitting layer 6, and two electrodes (first electrode 3 and second electrode 9) arranged to face each other. The electron transport layer 7 and the electron injection layer 8 are sandwiched. The hole injection layer 4, the hole transport layer 5, the light emitting layer 6, the electron transport layer 7, and the electron injection layer 8 are all organic layers, and are stacked in this order from the first electrode 3 side. The electron injection layer 8 may be an inorganic layer (metal layer, metal compound layer, etc.).

  In the present embodiment, the first electrode 3 is formed on the substrate 2, but the order of stacking from the substrate 2 side may be reversed. That is, even if the second electrode 9, the electron injection layer 8, the electron transport layer 7, the light emitting layer 6, the hole transport layer 5, the hole injection layer 4, and the first electrode 3 are stacked in this order from the substrate 2 side. Good.

  Moreover, the organic electroluminescent element compound of the present embodiment may be contained in any of the layers described above, but is preferably contained in the light emitting layer, the hole injection layer, the hole transport layer, and the electron transport layer.

  In the present embodiment, the first electrode 3 and the second electrode 9 function as a hole injecting electrode (anode) and an electron injecting electrode (cathode), respectively. As well as holes are injected from the second electrode 9, electrons are injected from the second electrode 9, and these recombination causes the organic electroluminescent element compound in the light emitting layer to emit light.

  The preferred thicknesses of the hole injection layer 4, the hole transport layer 5, the light emitting layer 6, the electron transport layer 7 and the electron injection layer 8 are all 1 to 200 nm.

(substrate)
The substrate 2 can be used without particular limitation as long as it is provided in a conventional organic electroluminescence device, and is an amorphous substrate such as glass or quartz, Si, GaAs, ZnSe, ZnS, GaP. A crystal substrate such as InP or a metal substrate such as Mo, Al, Pt, Ir, Au, Pd, or SUS can be used. Further, a thin film made of a crystalline or amorphous ceramic, metal, organic substance or the like formed on a predetermined substrate may be used.

  When the side of the substrate 2 is the light extraction side, it is preferable to use a transparent substrate such as glass or quartz as the substrate 2, and it is particularly preferable to use an inexpensive glass transparent substrate. The transparent substrate may be provided with a color filter film, a color conversion film containing a fluorescent material, a dielectric reflection film, or the like for adjusting the emission color.

(First electrode)
The first electrode 3 functions as a hole injection electrode (anode). Therefore, the material of the first electrode 3 can be used without particular limitation as long as it is provided in the conventional organic electroluminescent element, but it can be used efficiently and uniformly for the first electrode 3. A material capable of applying an electric field to is preferable.

  Further, when the substrate 2 side is the light extraction side, the transmittance at a wavelength of 400 nm to 700 nm, which is the emission wavelength region of the organic electroluminescent element, in particular, the transmittance of the first electrode 3 at the wavelength of each RGB color is 50%. Preferably, it is 80% or more, more preferably 90% or more. When the transmittance of the first electrode 3 is less than 50%, the light emission from the light emitting layer 6 is attenuated, and the luminance necessary for image display cannot be obtained.

The 1st electrode 3 with high light transmittance can be comprised using the transparent conductive film comprised with various oxides. As such a material, indium oxide (In ₂ O ₃ ), tin oxide (SnO ₂ ), zinc oxide (ZnO), tin-doped indium oxide (ITO), zinc-doped indium oxide (IZO), and the like are preferable. It is particularly preferable in that a thin film having a uniform in-plane specific resistance can be easily obtained.

  The film thickness of the first electrode 3 is preferably determined in consideration of the above-described light transmittance. For example, when using an oxide transparent electrode, the film thickness is preferably 10 to 500 nm, more preferably 30 to 300 nm. When the film thickness of the first electrode 3 exceeds 500 nm, the light transmittance becomes insufficient and the first electrode 3 may be peeled off from the substrate 2 in some cases. In addition, the light transmittance is improved as the film thickness is decreased. However, when the film thickness is less than 10 nm, the resistance increases and the driving voltage of the organic electroluminescent element tends to increase.

(Second electrode)
The second electrode 9 functions as an electron injection electrode (cathode). The material of the second electrode 9 can be used without particular limitation as long as it is provided in a conventional organic electroluminescent device, and examples thereof include metal materials, organometallic complexes, and metal compounds. In order to efficiently and reliably inject electrons into the light emitting layer 6, it is preferable to use a material having a relatively low work function, and it may be transparent.

  Specific examples of the metal material constituting the second electrode 9 include alkali metals such as Li, Na, K or Cs, alkaline earth metals such as Mg, Ca, Sr or Ba, or Al (aluminum). . Alternatively, a metal having properties similar to those of an alkali metal or alkaline earth metal such as La, Ce, Sn, Zn, or Zr can be used. Furthermore, oxides or halides of the above metal materials can also be used. Further, it may be a mixture or alloy containing the above materials, and a plurality of these may be laminated.

  The film thickness of the second electrode 9 may be such that electrons can be uniformly injected, and may be 0.1 nm or more.

  An auxiliary electrode may be provided on the second electrode 9. Thereby, the electron injection efficiency to the light emitting layer 6 can be improved, and the penetration | invasion of the water | moisture content or the organic solvent to the electron injection layer 8, the electron carrying layer 7, and the light emitting layer 6 can be prevented. As a material for the auxiliary electrode, a general metal can be used because there is no restriction on work function and charge injection capability. However, it is preferable to use a metal having high conductivity and easy handling. In particular, when the second electrode 9 includes an organic material, it is preferable to select appropriately according to the type and adhesion of the organic material.

  Examples of the material used for the auxiliary electrode include Al, Ag, In, Ti, Cu, Au, Mo, W, Pt, Pd, and Ni. Among them, by using a low-resistance metal such as Al and Ag. Electron injection efficiency can be further increased. Further, by using a metal compound such as TiN, higher sealing properties can be obtained. These materials may be used alone or in combination of two or more. Moreover, when using 2 or more types of metals, you may use as an alloy. Such an auxiliary electrode can be formed by, for example, a vacuum deposition method or the like.

(Hole injection layer)
The hole injection layer 4 is a layer containing a compound having a function of facilitating hole injection from the first electrode 3. Specifically, it can be formed using at least one kind of triarylamine derivative, azatriphenylene derivative, phthalocyanine derivative, polyaniline / organic acid, polythiophene / polymer acid and the like.

  When the compounds represented by the general formulas (1) to (3) according to the present embodiment are mixed with an electron acceptor such as antimony chloride, iron chloride, molybdenum oxide or the like in order to forcibly generate holes, The hole injection layer 4 can be used. In addition to the compound of the present embodiment and the electron acceptor, it is also possible to form the hole injection layer 4 by mixing one or more other materials. Since the pyrene derivative according to the present embodiment has a small ionization potential of 0.1 eV or more as compared with a pyrene derivative not including a dibenzo [a, c] fluorene structure, and efficient hole injection from the anode is possible. It is possible to realize an organic electroluminescent element with high luminous efficiency and low driving voltage. In addition, since the pyrene derivative according to this embodiment has low molecular crystallinity and can form a stable amorphous mixed layer with an electron acceptor compound, an organic electroluminescent device with higher durability can be formed. It is possible to realize.

(Hall transport layer)
The hole transport layer 5 is a layer containing a compound having a function of transporting injected holes to the light emitting layer 6 and a function of preventing electrons in the light emitting layer 6 from being injected into the hole transport layer 5. The hole transport layer 5 uses at least one kind of hydrocarbon compound such as triarylamine derivative, triarylmethane derivative, stilbene derivative, polysilane derivative, polyphenylene vinylene and derivative thereof, polythiophene and derivative thereof, carbazole derivative, or anthracene derivative. Can be formed.

  The compounds represented by the general formulas (1) to (3) according to this embodiment can be used as the hole transport layer 5. In particular, when a mixed layer of the compound represented by the general formulas (1) to (3) and the electron acceptor is used as the hole injection layer 4, the hole injection efficiency into the hole transport layer 5 is good. The hole transport layer 5 preferably contains the same material as the hole injection layer 4.

  In addition, the pyrene derivative according to the present embodiment has an ionization potential that is 0.1 eV or more lower than that of a pyrene derivative that does not include a dibenzo [a, c] fluorene structure, and therefore generally has an ionization potential smaller than that of the pyrene derivative. When used as a hole transport layer laminated on a hole injection layer of arylamine or the like, an organic electroluminescence device with high emission efficiency and low driving voltage can be realized because the hole injection barrier from the hole injection layer is small. It is.

  In addition, if it is a material which has the function of the hole injection layer 4 and the hole transport layer 5 as a hole injection transport layer, it can fulfill the function for two layers by a single layer. On the other hand, the hole injection layer 4 and the hole transport layer 5 can be further functionally separated into a plurality of layers.

(Light emitting layer)
The light emitting layer 6 is a layer containing a compound having a function of transporting injected holes and electrons and a function of generating excitons by recombination of holes and electrons. The compounds represented by the general formulas (1) to (3) according to this embodiment are preferably included in the light emitting layer 6 and more preferably included in the host material. An organic electroluminescent device comprising a light emitting layer 6 containing such a material reduces the generation of excimers or exciplexes due to molecular association, forms a stable amorphous film, and efficiently injects holes from the hole transport layer. Therefore, it is possible to obtain high luminous efficiency, color purity, and durability as compared with the conventional organic electroluminescent device.

  The light emitting layer 6 may use the compounds represented by the general formulas (1) to (3) alone as a constituent material, and contains the compounds represented by the general formulas (1) to (3). You may contain 1 type, or 2 or more types used as the material of the conventional light emitting layer. Moreover, the laminated structure of the compound expressed with General formula (1) thru | or (3) and another material may be sufficient.

  In addition to the host material, the light emitting layer 6 may contain one or more other fluorescent substances as a dopant. Examples of the fluorescent substance include compounds such as quinacridone, rubrene, and styryl dyes, metal complex compounds having 8-quinolinol or a derivative thereof such as tris (8-quinolinolato) aluminum as a ligand, anthracene derivatives, fluoranthene derivatives, Examples include a pyrene derivative, a perylene derivative, a fluorene derivative, a tetraarylethene derivative, an aromatic amine derivative, and the like. Examples of the dopant of the organic electroluminescence device according to this embodiment include a compound represented by the following general formula (4). More preferably it is included.

（一般式（４）において、
Ｙ^１は、置換もしくは無置換の炭素数６〜１２のアリール基、または置換もしくは無置換の環構成元素数５〜１２の含窒素芳香族複素環基である。
Ｙ^２乃至Ｙ^４は、それぞれ独立に、水素、置換もしくは無置換の炭素数６〜１２のアリール基、または置換もしくは無置換の環構成元素数５〜１２の含窒素芳香族複素環基である。
ただし、Ｙ^１乃至Ｙ^４の少なくとも１つは、置換もしくは無置換の環構成元素数５〜１２の含窒素芳香族複素環基、または、シアノ基もしくはトリフルオロメチル基が１つ以上置換した炭素数６〜１２のアリール基または環構成元素数５〜１２の含窒素芳香族複素環基である。）

(In general formula (4),
Y ¹ is a substituted or unsubstituted aryl group having 6 to 12 carbon atoms, or a substituted or unsubstituted nitrogen-containing aromatic heterocyclic group having 5 to 12 ring constituent elements.
Y ^{2 to} Y ⁴ are each independently hydrogen, a substituted or unsubstituted aryl group having 6 to 12 carbon atoms, or a substituted or unsubstituted nitrogen-containing aromatic heterocyclic group having 5 to 12 ring constituent elements. .
However, at least one of Y ^{1 to} Y ⁴ is a carbon atom substituted with one or more substituted or unsubstituted nitrogen-containing aromatic heterocyclic groups having 5 to 12 ring constituent elements, or a cyano group or a trifluoromethyl group. It is an aryl group of several 6 to 12 or a nitrogen-containing aromatic heterocyclic group having 5 to 12 ring constituent elements. )

  The benzo [k] fluoranthene represented by the general formula (4) of the present embodiment is aryl substituted with at least one nitrogen-containing aromatic heterocyclic group or one or more cyano groups or trifluoromethyl groups in the molecule. Since it has a group or a nitrogen-containing aromatic heterocyclic group, it has an electron affinity of 0.1 eV or more larger than that of benzo [k] fluoranthene not having the substituent, and exhibits a strong electron accepting property.

  Therefore, when benzo [k] fluoranthene represented by the general formula (4) is used as the dopant of the organic electroluminescent device, most of the electrons injected into the device are captured by the dopant on the cathode side of the light emitting layer. .

  In order to obtain high luminous efficiency as an organic electroluminescent device, it is necessary that recombination of both the hole and electron carriers in the dopant occurs efficiently. For this purpose, the dopant sufficiently captures the carrier, It is important that the carriers are sufficiently supplied to the dopant in the light emitting layer.

  That is, in the organic electroluminescent device using the dopant, it is necessary that the holes injected into the device are transported without delay to the cathode side of the light emitting layer where the dopant capturing electrons is present.

  The ionization potential of anthracene and pyrene derivatives, which are general host materials, is about 0.5 eV greater than that of diarylamine derivatives, which are general hole transport materials. In organic electroluminescent devices using these materials, the hole injection barrier from the hole transport layer to the light emitting layer is large, and the holes tend to accumulate at the interface between the hole transport layer and the light emitting layer (the anode side of the light emitting layer). Therefore, when a dopant having a high electron accepting property is used, holes cannot be sufficiently supplied to the dopant, and high luminous efficiency cannot be obtained.

  Since the pyrene derivative according to the present embodiment has an ionization potential of 0.1 eV or more lower than that of a pyrene derivative not including a dibenzo [a, c] fluorene structure, it can be used as a hole transport material such as diarylamine as a host material. When an organic electroluminescent element is formed by stacking, since the hole injection barrier from the hole transport layer is small, holes can be sufficiently supplied to the light emitting layer.

  For this reason, when the compound for organic electroluminescent elements of this embodiment is used as a host material and benzo [k] fluoranthene represented by the general formula (4) is used as a dopant, efficient recombination of holes and electrons occurs in the dopant. Therefore, it is possible to realize an organic electroluminescent element with high luminous efficiency.

  Therefore, the light-emitting layer 6 containing the pyrene derivative represented by the general formulas (1) to (3) of the present embodiment as a host material and the benzo [k] fluoranthene represented by the general formula (4) as a dopant is provided. The organic electroluminescence device has a small hole injection barrier from the hole transport layer to the light emitting layer, and efficient recombination of holes and electrons occurs in the dopant, so that high light emission efficiency can be obtained.

In General Formula (4), Y ¹ is a substituted or unsubstituted aryl group having 6 to 12 carbon atoms, or a substituted or unsubstituted nitrogen-containing aromatic heterocyclic group having 5 to 12 ring constituent elements; ^{2 to} Y ⁴ are each independently hydrogen, a substituted or unsubstituted aryl group having 6 to 12 carbon atoms, or a substituted or unsubstituted nitrogen-containing aromatic heterocyclic group having 5 to 12 ring constituent elements.

  The aryl group is preferably a phenyl group, a naphthyl group, a biphenylyl group, a fluorenyl group, a benzofluorenyl group, a phenanthryl group, an anthracenyl group, a pyrenyl group, or a terphenyl group from the viewpoint of ease of synthesis and luminous efficiency. A phenyl group, a naphthyl group, and a biphenylyl group are more preferable.

The aryl group may be further substituted with a substituent, and examples of such a substituent include an alkyl group, an alkoxy group, a halogeno group, a silyl group, a cyano group, and a trifluoromethyl group.
Among these substituents, a cyano group and a trifluoromethyl group are preferable from the viewpoint that the electron-accepting property of the dopant can be increased, electrons can be sufficiently captured in the light-emitting layer, and the light emission efficiency can be improved.

  The nitrogen-containing aromatic heterocyclic group is preferably a pyridinyl group, a pyrimidinyl group, a pyrazinyl group, a triazinyl group, an imidazolyl group, an oxazolyl group, a thiazolyl group, a benzoimidazolyl group, a quinoxalyl group, or an imidazopyridinyl group.

  The nitrogen-containing aromatic heterocyclic group may be further substituted with a substituent, and the substituent is preferably the same as the substituent for the aryl group.

  In the general formula (4), the number of substitutions of the cyano group or trifluoromethyl group is preferably 1 to 2. This is because when the number of substitutions is 3 or more, the emission wavelength becomes longer and blue light emission with high color purity cannot be obtained.

  Preferable examples of the compound represented by the general formula (4) according to this embodiment include compounds represented by the following formulas (IV-1) to (IV-33).

  When the compound of the general formula (4) is used as a dopant, the content relative to the host material is preferably 0.01 to 20 wt%, more preferably 0.1 to 15 wt%, and 0.1 to 8 wt% % Is more preferable.

  The light emitting layer 6 may contain other compounds such as a host material and a dopant. By mixing other compounds, carrier transport can be adjusted, and by mixing fluorescent dyes, the emission color can be converted and used. Examples of the compound for adjusting carrier transport include metal complex compounds having 8-quinolinol or a derivative thereof such as tris (8-quinolinolato) aluminum as a ligand, quinoxaline derivatives, pyridine derivatives, pyrimidine derivatives, imidazopyridine derivatives, Electron transporting compounds such as imidazopyrimidine derivatives and phenanthroline derivatives, hole transporting compounds such as triarylamine derivatives, and the like can be preferably used.

(Electron transport layer)
The electron transport layer 7 has a function of transporting injected electrons and a function of preventing holes from being injected into the electron transport layer 7 from the light emitting layer 6. The compounds represented by the general formulas (1) to (3) according to this embodiment can be used as the electron transport layer 7, and in particular, the compounds represented by the general formulas (1) to (3) are used in the light emitting layer 6. When used, since the electron injection efficiency from the light emitting layer 6 is good, it is preferable to include the same material as the light emitting layer 6 in the electron transport layer 7.

  In addition, a pyrene derivative and an anthracene derivative that do not contain a dibenzo [a, c] fluorene structure have an ionization potential that is 0.1 eV or more higher than that of the pyrene derivative of the present embodiment. Therefore, when the pyrene derivative of the present embodiment is used for the light emitting layer 6 and a pyrene derivative and an anthracene derivative not containing a dibenzo [a, c] fluorene structure are used for the electron transport layer 7, electron transport from the light emitting layer 6 is performed. Since hole outflow to the layer 7 can be prevented, an organic electroluminescent device having high luminous efficiency and durability can be obtained.

(Electron injection layer)
The electron injection layer 8 has a function of facilitating injection of electrons from the second electrode 9 and a function of improving adhesion with the second electrode 9. The electron injection layer 8 is composed of a metal complex, an oxadiazole derivative, a triazole derivative, a triazine derivative, a quinoline derivative, a quinoxaline derivative, a pyridine derivative having a ligand such as tris (8-quinolinolato) aluminum and the like. , Pyrimidine derivatives, imidazole derivatives, imidazopyrimidine derivatives, phenanthroline derivatives and the like can be used.

  The organic electroluminescence device 1 according to this embodiment is known except that the light emitting layer 6, the hole injection layer 4, the hole transport layer 5, and the electron transport layer 7 contain the compound for an organic electroluminescence device according to this embodiment. It can manufacture by the method of. As a method of forming each organic layer including the light emitting layer 6, the hole injection layer 4, the hole transport layer 5, and the electron transport layer 7, a vacuum deposition method, an ionization deposition method, a coating method, etc. are used. Depending on the material to be configured, it can be selected and adopted as appropriate.

  Specific examples of the coating method include spin coating methods, various printing methods such as gravure printing, and ink jet methods. Examples of the solvent used in this coating method include hydrocarbon solvents such as toluene and xylene, and halogen solvents such as dichloroethane. The compounds represented by the general formulas (1) to (3) according to the present embodiment have high solubility and can be sufficiently formed even by a coating process. In the case of the spin coating method, a thin film of about 50 nm to 200 nm can be formed by using a solution having a concentration of about 1 to 3%.

  The preferred embodiment of the present invention has been described above, but the present invention is not limited to the above embodiment.

  Hereinafter, the contents of the present invention will be described more specifically with reference to examples and comparative examples. In addition, this invention is not limited to the following Example.

<Synthesis Example 1>
The following compound (11) was synthesized by the following method. The reaction formula is shown below.

(Synthesis of 9- (2-carbomethoxy-4-chlorophenyl) phenanthrene (1-1))
Under an argon stream, 15.32 g (61.4 mmol) of methyl 2-bromo-5-chlorobenzoate, 15.00 g (67.5 mmol) of 9-phenanthreneboronic acid, 1.42 g of tetrakis (triphenylphosphine) palladium (0) (1.23 mmol) was dissolved in 110 ml of toluene and 40 ml of ethanol. Next, 92 ml of an aqueous solution containing 184.0 mmol of sodium carbonate was added, and the mixture was stirred for 19 hours under reflux with heating. After cooling to room temperature, water was added to the reaction solution and extracted with toluene. The organic layer was dried over magnesium sulfate and concentrated under reduced pressure. The resulting crude product was purified by column chromatography to obtain the desired 9- (2-carbomethoxy-4-chlorophenyl) phenanthrene (1-1) white solid (yield 21.16 g, yield 99%). It was.

(Synthesis of 9- [4-chloro-2- (2-hydroxy-2-methylethyl) phenyl] phenanthrene (1-2))
In an argon stream, 21.16 g (61.0 mmol) of 9- (2-carbomethoxy-4-chlorophenyl) phenanthrene (1-1) synthesized by the above reaction was added to 90 ml of a dehydrated diethyl ether solution containing 180.0 mmol of methyl magnesium iodide. ) Was added dropwise over 30 minutes, and the mixture was stirred at room temperature for 22 hours. A saturated aqueous ammonium chloride solution was added to the reaction solution, and the mixture was extracted with diethyl ether. The organic layer was washed with saturated brine, dried over magnesium sulfate, and concentrated under reduced pressure. The obtained crude product was purified by column chromatography to obtain the desired 9- [4-chloro-2- (2-hydroxy-2-methylethyl) phenyl] phenanthrene (1-2) as a white solid (yield 17. 37 g, 78% yield).

(Synthesis of 11-chloro-13,13-dimethyl-13H indeno [1; 2-1] phenanthrene (1-3))
Under argon flow, 17.37 g (50.0 mmol) of 9- [4-chloro-2- (2-hydroxy-2-methylethyl) phenyl] phenanthrene (1-2) synthesized by the above reaction was added to 150 ml of dehydrated dichloromethane. Dissolved and cooled in an ice bath. 9.3 ml (75.0 mmol) of boron trifluoride diethyl ether complex was added dropwise over 10 minutes, and then stirred at room temperature for 17 hours. Water was added to the reaction solution and extracted with dichloromethane. The organic layer was dried over magnesium sulfate and concentrated under reduced pressure. The obtained crude product was purified by column chromatography, and the desired 11-chloro-13,13-dimethyl-13H indeno [1; 2-1] phenanthrene (1-3) white solid (yield 15.95 g, Yield 97%).

(2- (13,13-dimethyl-13Hindeno [1; 2-1) phenanthren-11-yl) -4,4,5,5-tetramethyl-1,3,2-dioxaborolane (1-4) Synthesis)
11-Chloro-13,13-dimethyl-13Hindeno [1; 2-1] phenanthrene (1-3) 15.62 g (47.5 mmol) synthesized by the above reaction under an argon stream, bis (pinacolato) diboron 18 .11 g (71.3 mmol), tris (dibenzylideneacetone) dipalladium (0) 0.44 g (0.48 mmol), 2-dicyclohexylphosphino-2 ′, 4 ′, 6′-triisopropylbiphenyl 0.46 g ( 0.96 mmol) and 13.99 g (142.5 mmol) of potassium acetate were dissolved in 40 ml of dehydrated 1,4-dioxane, and the mixture was stirred for 3 hours with heating under reflux. After cooling to room temperature, the mixture was concentrated under reduced pressure, water was added, and the mixture was extracted with chloroform. The organic layer was washed with saturated brine, dried over magnesium sulfate, and concentrated under reduced pressure. The obtained crude product was purified by column chromatography and recrystallized from dichloromethane-hexane to give the desired 2- (13,13-dimethyl-13Hindeno [1; 2-1] phenanthren-11-yl) -4. , 4,5,5-tetramethyl-1,3,2-dioxaborolane (1-4) was obtained as a white powder (yield 18.37 g, yield 92%).

(Synthesis of 1- (4-bromophenyl) pyrene (1-5))
Under an argon stream, 9.44 g (40.0 mmol) of 1,4-dibromobenzene, 2.46 g (10.0 mmol) of 1-pyreneboronic acid, 0.23 g (0.20 mmol) of tetrakis (triphenylphosphine) palladium (0) Was dissolved in 40 ml of toluene and 8 ml of ethanol. Next, 15 ml of an aqueous solution containing 30.0 mmol of sodium carbonate was added, and the mixture was stirred for 22 hours while heating under reflux. After cooling to room temperature, water was added to the reaction solution and extracted with toluene. The organic layer was dried over magnesium sulfate and concentrated under reduced pressure. The resulting crude product was purified by column chromatography and recrystallized from dichloromethane-methanol to obtain the desired 1- (4-bromophenyl) pyrene (1-5) white solid (yield 2.47 g, yield 69). %).

(Synthesis of 13,13-dimethyl-11- [4- (1-pyrenyl) phenyl] -13Hindeno [1; 2-l] phenanthrene (11))
2- (13,13-dimethyl-13Hindeno [1; 2-1] phenanthren-11-yl) -4,4,5,5-tetramethyl-1,3, synthesized by the above reaction under an argon stream 2-dioxaborolane (1-4) 1.791 g (4.23 mmol), 1- (4-bromophenyl) pyrene (1-5) 1.39 g (3.88 mmol), palladium acetate (0) 0.027 g (0 .12 mmol), 0.099 g (0.24 mmol) of 2-dicyclohexylphosphino-2 ′, 6′-dimethoxybiphenyl, and 1.65 g (7.76 mmol) of potassium phosphate tribasic acid were dissolved in 20 ml of toluene and 1 ml of water. The mixture was stirred for 23 hours under heating and reflux. After cooling to room temperature, the mixture was concentrated under reduced pressure, water was added, and the mixture was extracted with chloroform. The organic layer was dried over magnesium sulfate and concentrated under reduced pressure. The obtained crude product was purified by column chromatography, recrystallized from dichloromethane-methanol and toluene, and the desired 13,13-dimethyl-11- [4- (1-pyrenyl) phenyl] -13H indeno [1; A white powder of 2-l] phenanthrene (11) (yield 1.61 g, yield 72%) was obtained. Further, purification by sublimation was performed to obtain a product having a purity of 99.0% (confirmed by high performance liquid chromatography (HPLC)).

In addition, when the obtained compound was subjected to mass spectrometry, a peak was confirmed at m / z = 570 (M ⁺ ). Furthermore, it was analyzed using the compound ¹ H- nuclear magnetic resonance ⁽¹ H-NMR) method, ¹ H-NMR spectrum shown in Figure 2 is ^obtained, 13 C-nuclear magnetic resonance ⁽¹³ C-NMR) When analyzed by the method, the ¹³ C-NMR spectrum shown in FIG. 3 was obtained. Thus, it was confirmed that the compound obtained in Synthesis Example 1 was the compound (11).

<Synthesis Example 2>
The following compound (12) was synthesized by the following method. The reaction formula is shown below.

(Synthesis of 1- (3-bromophenyl) pyrene (1-6))
Under an argon stream, 1.84 ml (40.0 mmol) of 1,3-dibromobenzene, 2.46 g (10.0 mmol) of 1-pyreneboronic acid, 0.23 g (0.20 mmol) of tetrakis (triphenylphosphine) palladium (0) Was dissolved in 40 ml of toluene and 8 ml of ethanol. Next, 15 ml of an aqueous solution containing 30.0 mmol of sodium carbonate was added, and the mixture was stirred for 22 hours while heating under reflux. After cooling to room temperature, water was added to the reaction solution and extracted with toluene. The organic layer was dried over magnesium sulfate and concentrated under reduced pressure. The resulting crude product was purified by column chromatography and recrystallized from dichloromethane-methanol to obtain the desired 1- (3-bromophenyl) pyrene (1-6) white solid (yield 2.32 g, yield 65). %).

(Synthesis of 13,13-dimethyl-11- [3- (1-pyrenyl) phenyl] -13Hindeno [1; 2-1] phenanthrene (12))
2- (13,13-dimethyl-13Hindeno [1; 2-1] phenanthren-11-yl) -4,4,5,5-tetramethyl-1,3, synthesized by the above reaction under an argon stream 2-dioxaborolane (1-4) 1.681 g (4.00 mmol), 1- (3-bromophenyl) pyrene (1-6) 1.30 g (3.64 mmol), palladium acetate (0) 0.027 g (0 .12 mmol), 0.099 g (0.24 mmol) of 2-dicyclohexylphosphino-2 ′, 6′-dimethoxybiphenyl and 1.55 g (7.28 mmol) of potassium phosphate tribasic acid were dissolved in 20 ml of toluene and 1 ml of water. The mixture was stirred for 20 hours under heating and reflux. After cooling to room temperature, the mixture was concentrated under reduced pressure, water was added, and the mixture was extracted with chloroform. The organic layer was dried over magnesium sulfate and concentrated under reduced pressure. The obtained crude product was purified by column chromatography, recrystallized from dichloromethane-methanol and toluene, and the desired 13,13-dimethyl-11- [3- (1-pyrenyl) phenyl] -13H indeno [1; A white powder of 2-l] phenanthrene (12) (yield 1.78 g, yield 78%) was obtained. Further, purification by sublimation was performed to obtain a product having a purity of 99.0% (confirmed by high performance liquid chromatography (HPLC)).

In addition, when the obtained compound was subjected to mass spectrometry, a peak was confirmed at m / z = 570 (M ⁺ ). Furthermore, it was analyzed using the compound ¹ H- nuclear magnetic resonance ⁽¹ H-NMR) method, ¹ H-NMR spectrum shown in Figure 4 is ^obtained, 13 C-nuclear magnetic resonance ⁽¹³ C-NMR) When analyzed by the method, the ¹³ C-NMR spectrum shown in FIG. 5 was obtained. Thus, it was confirmed that the compound obtained in Synthesis Example 2 was the compound (12).

<Synthesis Example 3>
The following compound (13) was synthesized by the following method. The reaction formula is shown below.

(Synthesis of 9- {4-chloro-2- [hydroxy (diphenyl) methyl] phenyl} phenanthrene (1-7))
Under an argon stream, 10.08 g (29.9) of 9- (4-chloro-2-carbomethoxyphenyl) phenanthrene (1-1) synthesized by the above reaction was added to 130 ml of a dehydrated diethyl ether solution containing 87.3 mmol of magnesium magnesium iodide. 90 ml of a dehydrated tetrahydrofuran solution containing 1 mmol) was added dropwise over 30 minutes, and the mixture was stirred for 22 hours while heating under reflux. The reaction solution was cooled to room temperature, saturated aqueous ammonium chloride solution was added, and the mixture was extracted with diethyl ether. The organic layer was washed with saturated brine, dried over magnesium sulfate, and concentrated under reduced pressure. The obtained crude product was purified by column chromatography to obtain the desired 9- {4-chloro-2- [hydroxy (diphenyl) methyl] phenyl} phenanthrene (1-7) white solid (yield 9.06 g, yield). 66%) was obtained.

(Synthesis of 11-chloro-13,13-diphenyl-13H indeno [1; 2-1] phenanthrene (1-8))
Under an argon stream, 8.96 g (19.0 mmol) of 9- {4-chloro-2- [hydroxy (diphenyl) methyl] phenyl} phenanthrene (1-7) synthesized by the above reaction was dissolved in 80 ml of dehydrated dichloromethane, Cooled in an ice bath. 2.70 ml (28.5 mmol) of boron trifluoride diethyl ether complex was added dropwise over 5 minutes, and then stirred at room temperature for 20 hours. Water was added to the reaction solution and extracted with dichloromethane. The organic layer was dried over magnesium sulfate and concentrated under reduced pressure. The resulting crude product was purified by column chromatography and recrystallized from dichloromethane-methanol to obtain the desired 11-chloro-13,13-diphenyl-13Hindeno [1; 2-1-phenanthrene (1-8). A white solid (yield 7.21 g, yield 75%) was obtained.

(Synthesis of 1- (3-biphenyl) -6-bromopyrene (1-9))
Under an argon stream, 1,6-dibromopyrene 5.30 g (14.7 mmol), 3-biphenylboronic acid 1.58 g (8.0 mmol), tetrakis (triphenylphosphine) palladium (0) 0.28 g (0.24 mmol) ) Was dissolved in 80 ml of toluene and 6 ml of ethanol. Next, 12 ml of an aqueous solution containing 24.0 mmol of sodium carbonate was added, and the mixture was stirred for 17 hours while heating under reflux. After cooling to room temperature, water was added to the reaction solution and extracted with toluene. The organic layer was dried over magnesium sulfate and concentrated under reduced pressure. The resulting crude product was purified by column chromatography and recrystallized from dichloromethane-methanol to obtain the desired 1- (3-biphenyl) -6-bromopyrene (1-9) white solid (yield 1.55 g, yield). Rate 45%).

(Synthesis of 4,4,5,5-tetramethyl-2- (6-phenyl-1-pyrenyl) -1,3,2-dioxaborolane (1-10))
1.545 g (3.56 mmol) of 1- (3-biphenyl) -6-bromopyrene (1-9) synthesized by the above reaction under an argon stream, 1.356 g (5.34 mmol) of bis (pinacolato) diboron, Tris (Dibenzylideneacetone) dipalladium (0) 0.064 g (0.070 mmol), 2-dicyclohexylphosphino-2 ′, 4 ′, 6′-triisopropylbiphenyl 0.067 g (0.14 mmol), potassium acetate 048 g (10.68 mmol) was dissolved in 50 ml of dehydrated 1,4-dioxane and stirred for 17 hours while heating under reflux. After cooling to room temperature, the mixture was concentrated under reduced pressure, water was added, and the mixture was extracted with chloroform. The organic layer was washed with saturated brine, dried over magnesium sulfate, and concentrated under reduced pressure. The obtained crude product was purified by column chromatography to obtain the desired 4,4,5,5-tetramethyl-2- (6-phenyl-1-pyrenyl) -1,3,2-dioxaborolane (1-10 ) White solid (yield 1.06 g, 62% yield).

(Synthesis of 11- [6- (3-biphenyl) pyren-1-yl] -13,13-diphenyl-13H indeno [1; 2-1] phenanthrene (13))
1.101 g (2.43 mmol) of 11-chloro-13,13-diphenyl-13Hindeno [1; 2-1] phenanthrene (1-8) synthesized by the above reaction under an argon stream, 4, 4, 5, 5-tetramethyl-2- (6-phenyl-1-pyrenyl) -1,3,2-dioxaborolane (1-10) 1.064 g (2.21 mmol), palladium acetate (0) 0.025 g (0.11 mmol) ), 0.090 g (0.22 mmol) of 2-dicyclohexylphosphino-2 ′, 6′-dimethoxybiphenyl and 0.936 g (4.41 mmol) of potassium phosphate tribasic acid were dissolved in 30 ml of toluene and 0.5 ml of water. And stirred for 17 hours under reflux. After cooling to room temperature, the mixture was concentrated under reduced pressure, water was added, and the mixture was extracted with chloroform. The organic layer was dried over magnesium sulfate and concentrated under reduced pressure. The obtained crude product was purified by column chromatography and recrystallized from toluene to obtain the desired 11- [6- (3-biphenyl) pyren-1-yl] -13,13-diphenyl-13H indeno [1; A white powder of 2-l] phenanthrene (13) was obtained (yield 1.03 g, yield 60%). Furthermore, sublimation purification was performed to obtain a product having a purity of 99.8% (confirmed by high performance liquid chromatography (HPLC)).

In addition, when the obtained compound was subjected to mass spectrometry, a peak was confirmed at m / z = 770 (M ⁺ ). Furthermore, it was analyzed using the compound ¹ H- nuclear magnetic resonance ⁽¹ H-NMR) method, ¹ H-NMR spectrum shown in Figure 6 is ^obtained, 13 C-nuclear magnetic resonance ⁽¹³ C-NMR) When analyzed using the method, the ¹³ C-NMR spectrum shown in FIG. 7 was obtained. Thus, it was confirmed that the compound obtained in Synthesis Example 3 was the compound (13).

<Synthesis Example 4>
The following compound (14) was synthesized by the following method. The reaction formula is shown below.

(Synthesis of 11- [6- (3-biphenyl) pyren-1-yl] -13,13-dimethyl-13Hindeno [1; 2-l] phenanthrene (14))
1.040 g (2.40 mmol) of 1- (3-biphenyl) -6-bromopyrene (1-9) synthesized by the above reaction under an argon stream, 2- (13,13-dimethyl-13H indeno [1; 2 -L] phenanthrene-11-yl) -4,4,5,5-tetramethyl-1,3,2-dioxaborolane (1-4) 1.211 g (2.88 mmol), palladium acetate (0) 0.027 g (0.12 mmol), 0.099 g (0.24 mmol) of 2-dicyclohexylphosphino-2 ′, 6′-dimethoxybiphenyl, 1.019 g (4.80 mmol) of potassium phosphate tribasic acid, 30 ml of toluene and 0. Dissolve in 5 ml and stir for 17 hours under heating to reflux. After cooling to room temperature, the mixture was concentrated under reduced pressure, water was added, and the mixture was extracted with chloroform. The organic layer was dried over magnesium sulfate and concentrated under reduced pressure. The obtained crude product was purified by column chromatography and recrystallized from toluene to obtain the desired 11- [6- (3-biphenyl) pyren-1-yl] -13,13-dimethyl-13H indeno [1; A white powder (yield 1.24 g, yield 80%) of 2-l] phenanthrene (14) was obtained. Furthermore, sublimation purification was performed to obtain a product having a purity of 99.8% (confirmed by high performance liquid chromatography (HPLC)).

In addition, when the obtained compound was subjected to mass spectrometry, a peak was confirmed at m / z = 646 (M ⁺ ). Furthermore, it was analyzed using the compound ¹ H- nuclear magnetic resonance ⁽¹ H-NMR) method, ¹ H-NMR spectrum shown in Figure 8 is ^obtained, 13 C-nuclear magnetic resonance ⁽¹³ C-NMR) When analyzed using the method, the ¹³ C-NMR spectrum shown in FIG. 9 was obtained. Thus, it was confirmed that the compound obtained in Synthesis Example 4 was the compound (14).

<Synthesis Example 5>
The following compound (15) was synthesized by the following method. The reaction formula is shown below.

(Synthesis of 1-bromo-6-phenylpyrene (1-11))
Under an argon stream, 5.176 g (14.4 mmol) of 1,6-dibromopyrene, 0.975 g (8.0 mmol) of phenylboronic acid, 0.277 g (0.24 mmol) of tetrakis (triphenylphosphine) palladium (0) were added. It was dissolved in 80 ml of toluene and 6 ml of ethanol. Next, 12 ml of an aqueous solution containing 24.0 mmol of sodium carbonate was added, and the mixture was stirred for 17 hours while heating under reflux. After cooling to room temperature, water was added to the reaction solution and extracted with toluene. The organic layer was dried over magnesium sulfate and concentrated under reduced pressure. The resulting crude product was purified by column chromatography and recrystallized from dichloromethane-methanol to obtain the desired 1-bromo-6-phenylpyrene (1-11) white solid (yield 1.41 g, yield 49%). )

(Synthesis of 11- (4-chlorophenyl) -13,13-dimethyl-13Hindeno [1; 2-1] phenanthrene (1-12))
2- (13,13-dimethyl-13Hindeno [1; 2-1] phenanthren-11-yl) -4,4,5,5-tetramethyl-1,3, synthesized by the above reaction under an argon stream 2-dioxaborolane (1-4) 4.170 g (9.92 mmol), 1-bromo-4-chlorobenzene 7.658 g (40.0 mmol), palladium acetate (0) 0.045 g (0.20 mmol), 2-dicyclohexyl Phosphino-2 ′, 6′-dimethoxybiphenyl 0.164 g (0.40 mmol) and potassium phosphate tribasic acid 4.246 g (20.0 mmol) were dissolved in toluene 50 ml and water 2 ml, and heated under reflux for 4 hours. Stir. After cooling to room temperature, the mixture was concentrated under reduced pressure, water was added, and the mixture was extracted with toluene. The organic layer was dried over magnesium sulfate and concentrated under reduced pressure. The resulting crude product was purified by column chromatography and recrystallized from dichloromethane-methanol to obtain the desired 11- (4-chlorophenyl) -13; 13-dimethyl-13H indeno [1; 2-l] phenanthrene (1 -12) white powder (yield 3.71 g, yield 92%).

(2- [4- (13,13-dimethyl-13Hindeno [1; 2-1] phenanthrene-11-yl) phenyl] -4,4,5,5-tetramethyl-1,3,2-dioxaborolane ( Synthesis of 1-13)
11- (4-Chlorophenyl) -13; 13-dimethyl-13Hindeno [1; 2-1-phenanthrene (1-12) 3.711 g (9.16 mmol), bis ( Pinacolato) diboron 3.479 g (13.7 mmol), tris (dibenzylideneacetone) dipalladium (0) 0.183 g (0.20 mmol), 2-dicyclohexylphosphino-2 ′, 4 ′, 6′-triisopropylbiphenyl 0.191 g (0.40 mmol) and 2.699 g (27.5 mmol) of potassium acetate were dissolved in 40 ml of dehydrated 1,4-dioxane and stirred for 68 hours under heating to reflux. After cooling to room temperature, the mixture was concentrated under reduced pressure, and the resulting crude product was purified by column chromatography to obtain the desired 2- [4- (13,13-dimethyl-13Hindeno [1; 2-1] phenanthrene- 11-yl) phenyl] -4,4,5,5-tetramethyl-1,3,2-dioxaborolane (1-13) was obtained as a white solid (yield 3.29 g, yield 72%).

(Synthesis of 13,13-dimethyl-11- [4- (6-phenyl-1-pyrenyl) phenyl] -13Hindeno [1; 2-l] phenanthrene (15))
1.410 g (3.95 mmol) of 1-bromo-6-phenylpyrene (1-11) synthesized by the above reaction under an argon stream, 2- [4- (13,13-dimethyl-13Hindeno [1; 2] -L] phenanthrene-11-yl) phenyl] -4,4,5,5-tetramethyl-1,3,2-dioxaborolane (1-13) 2.184 g (4.40 mmol), palladium acetate (0) 0 0.045 g (0.20 mmol), 2-dicyclohexylphosphino-2 ′, 6′-dimethoxybiphenyl 0.164 g (0.40 mmol), potassium phosphate tribasic acid 1.679 g (7.90 mmol) in toluene 70 ml and water It was dissolved in 0.5 ml and stirred for 19 hours under heating to reflux. After cooling to room temperature, the mixture was concentrated under reduced pressure, water was added, and the mixture was extracted with chloroform. The organic layer was dried over magnesium sulfate and concentrated under reduced pressure. The resulting crude product was purified by column chromatography and recrystallized from dichloromethane-methanol and toluene to obtain the desired 13,13-dimethyl-11- [4- (6-phenyl-1-pyrenyl) phenyl] -13H. A white powder (yield 2.13 g, yield 83%) of indeno [1; 2-l] phenanthrene (15) was obtained. Furthermore, sublimation purification was performed to obtain a 98.8% pure product (purity confirmed by high performance liquid chromatography (HPLC)).

In addition, when the obtained compound was subjected to mass spectrometry, a peak was confirmed at m / z = 646 (M ⁺ ). Also, Analysis of this compound ¹ H- using nuclear magnetic resonance ⁽¹ H-NMR) method, ¹ H-NMR spectrum shown in Figure 10 is ^obtained, 13 C-nuclear magnetic resonance ⁽¹³ C-NMR) When analyzed by the method, the ¹³ C-NMR spectrum shown in FIG. 11 was obtained. Thus, it was confirmed that the compound obtained in Synthesis Example 5 was the compound (15).

  DSC and TG-DTA measurement of the compounds (11) to (13) and the comparative compounds (31) and (32) obtained in Synthesis Examples 1 to 3 were performed. The results are shown in Table 1.

  Since the synthetic compounds (11) to (13) have a higher glass transition temperature and decomposition initiation temperature than the comparative compounds (31) and (32), it is possible to form a stable amorphous film with low crystallinity. It is a stable compound with excellent thermal effects. Therefore, it can be preferably used to realize a highly durable organic electroluminescent device.

  Further, the ionization potential (maximum occupied orbit energy) of the synthetic compound (13) and the comparative compound (31) was measured using atmospheric photoelectron spectroscopy (manufactured by Riken Instruments, measuring instrument name: AC-2). The results are shown in Table 2.

  The synthetic compound (13) has an ionization potential smaller by 0.14 eV than the comparative compound (31) having no dibenzo [a, c] fluorene structure. For this reason, when used as a host material of an organic electroluminescence device, the hole injection barrier from the hole transport layer to the light emitting layer is small, and it is possible to realize high light emission efficiency and a decrease in driving voltage.

<Example 1>
An ITO transparent electrode having a thickness of 100 nm was formed on a glass substrate by RF sputtering and patterned. This glass substrate with an ITO transparent electrode was subjected to ultrasonic cleaning using a neutral detergent, acetone and ethanol, and then pulled up from boiling ethanol and dried. After the surface of the transparent electrode was washed with UV / O _3, it was fixed to a substrate holder of a vacuum deposition apparatus, and the inside of the layer was depressurized to 1 × 10 ⁻⁴ Pa or less.

  Next, while maintaining the reduced pressure state, dipyrazino [2,3-f: 2 ′, 3′-h] quinoxaline-2,3,6,7,10,11-hexacarbonitrile (21) having the following structure was obtained. Vapor deposition was performed at a deposition rate of 0.1 nm / sec to a thickness of 5 nm to form a hole injection layer.

  Next, N, N, N ′, N′-tetrakis (3-biphenylyl) -1,1′-biphenyl-4,4′-diamine (22) having the following structure was deposited while maintaining the reduced pressure state. Vapor deposition was performed at a thickness of 80 nm at 0.1 nm / sec to form a hole transport layer.

  Further, while maintaining the reduced pressure state, the compound (11) of the present embodiment as the host material and the compound (IV-1) of the present embodiment as the dopant at a mass ratio of 95: 5 and an overall deposition rate of 0. A light emitting layer was formed by vapor deposition to a thickness of 40 nm at 1 nm / sec.

  Further, while maintaining the reduced pressure state, the compound (11) of the present embodiment was deposited to a thickness of 20 nm at a deposition rate of 0.1 nm / sec to form an electron transport layer.

  Further, while maintaining the reduced pressure state, 9,10-bis [4- (imidazo [1,2-a] pyridin-2-yl) phenyl] anthracene (23) having the following structure was deposited at a deposition rate of 0.1 nm / The film was successively deposited to a thickness of 10 nm in sec to form an electron injection layer.

  Next, LiF was deposited at a deposition rate of 0.1 nm / sec to a thickness of 1.2 nm, used as an electron injection electrode, Al as a protective electrode was deposited to a thickness of 100 nm, and finally sealed with glass to produce organic electroluminescence. An element was obtained.

The produced organic electroluminescence device was measured for light emission efficiency, chromaticity (CIEx, CIEy), voltage, and half life at an initial luminance of 1000 cd / m ² when driven at a current density of 10 mA / cm ² . The results are shown in Table 3.

<Examples 2-18, Comparative Examples 1-6>
An organic electroluminescent element was produced in the same manner as in Example 1 except that the compounds described in Table 3 were used instead of the compound (11) and the compound (IV-1). Table 3 shows the light emission efficiency, chromaticity (CIEx, CIEy), voltage, and half life at an initial luminance of 1000 cd / m ² when these elements are driven at a current density of 10 mA / cm ² . In addition, the comparative example compounds (31) to (34) have the structures shown below.

<Example 19>
An organic electroluminescent element was produced in the same manner as in Example 1 except that the following compound (51) was used as the electron transport layer. Table 3 shows the light emission efficiency, chromaticity (CIEx, CIEy), voltage, and half-life at an initial luminance of 1000 cd / m ² when the device is driven at a current density of 10 mA / cm ² .

According to Examples 1 to 19 and Comparative Examples 1 to 6, the organic electroluminescent device using the compound of the present embodiment as a host material was compared with devices using the comparative compounds (31) to (34) as a host material. It was shown that luminous efficiency, blue color purity, durability were high, and driving voltage was low.
Moreover, it was shown that the organic electroluminescent element which used the compound of this embodiment as a dopant has high luminous efficiency and durability compared with the element which used the comparative compound (41) as a dopant. The organic electroluminescent device having a light emitting layer composed of a host material that lowers the hole injection barrier from the hole transport layer to the light emitting layer and a high electron accepting dopant used in Examples 1 to 19 Since efficient recombination occurs, it is possible to realize high light emission efficiency and suppression of lifetime reduction due to the outflow of carriers not involved in recombination from the light emitting layer to both electrodes.

<Example 20>
An ITO transparent electrode having a thickness of 100 nm was formed on a glass substrate by RF sputtering and patterned. This glass substrate with an ITO transparent electrode was subjected to ultrasonic cleaning using a neutral detergent, acetone and ethanol, and then pulled up from boiling ethanol and dried. After the surface of the transparent electrode was washed with UV / O _3, it was fixed to a substrate holder of a vacuum deposition apparatus, and the inside of the layer was depressurized to 1 × 10 ⁻⁴ Pa or less.

  Next, while maintaining the reduced pressure state, the compound (11) of this embodiment and molybdenum oxide as an electron acceptor were deposited in a volume ratio of 95: 5 to a film thickness of 50 nm at an overall deposition rate of 0.1 nm / sec. And a hole injection layer.

  Next, while maintaining the reduced pressure state, the compound (11) of the present embodiment was deposited to a thickness of 50 nm at a deposition rate of 0.1 nm / sec to form a hole transport layer.

  Further, while maintaining the reduced pressure state, the compound (11) of the present embodiment as a host material and the compound (IV-1) of the present embodiment as a dopant at a volume ratio of 95: 5, with an overall deposition rate of 0.1 nm / The film was deposited in a thickness of 40 nm in sec to obtain a light emitting layer.

  Further, while maintaining the reduced pressure state, the compound (11) of the present embodiment was deposited to a thickness of 20 nm at a deposition rate of 0.1 nm / sec to form an electron transport layer.

Further, while maintaining the reduced pressure state, the compound (23) was successively deposited to a thickness of 10 nm at a deposition rate of 0.1 nm / sec to form an electron injection layer.

  Next, LiF was deposited at a deposition rate of 0.1 nm / sec to a thickness of 1.2 nm, used as an electron injection electrode, Al as a protective electrode was deposited to a thickness of 100 nm, and finally sealed with glass to produce organic electroluminescence. An element was obtained.

The produced organic electroluminescence device was measured for luminous efficiency, chromaticity (CIEx, CIy), voltage, and half life at an initial luminance of 1000 cd / m ² when driven at a current density of 10 mA / cm ² . The results are shown in Table 4.

<Examples 21 to 29, Comparative Examples 7 to 11>
An organic electroluminescent element was produced in the same manner as in Example 20 except that the compounds described in Table 4 were used instead of the compound (11) and the compound (IV-1). Table 4 shows the light emission efficiency, chromaticity (CIEx, CIEy), voltage, and half-life at an initial luminance of 1000 cd / m ² when driving at a current density of 10 mA / cm ² .

  According to Examples 20 to 29 and Comparative Examples 7 to 11, the organic electroluminescent elements in which the compounds used in Examples 20 to 29 were contained in the organic layer were obtained by comparing the comparative compounds (31) to (34) and (41). It was shown that the luminous efficiency, blue color purity and durability were high and the driving voltage was low compared to the included organic electroluminescent device.

  As described above in detail, the compound for organic electroluminescence device of the present invention contains organic electroluminescence that exhibits high emission efficiency and high color purity, blue emission, and high durability by containing the compound in the organic thin film layer. An element can be realized.

DESCRIPTION OF SYMBOLS 1 ... Organic electroluminescent element concerning this embodiment, 2 ... Substrate, 3 ... 1st electrode, 4 ... Hole injection layer, 5 ... Hole transport layer, 6 ... Light emitting layer, 7 ... Electron transport layer, 8 ... Electron injection Layer, 9 ... second electrode, P ... power source.

Claims (8)

The compound for organic electroluminescent elements characterized by being represented by any one of the following general formulas (1) to (3).

(In the general formulas (1) to (3), X ¹ and X ² each independently represent a single bond or a substituted or unsubstituted arylene group having 6 to 20 carbon atoms, and X ¹ represents a position a, Bonded with any of b, c, d, and X ² binds with any of the positions e, f, g, h Ar is a substituted or unsubstituted aryl group having 6 to 20 carbon atoms R ¹ To R ⁴ are each independently a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms or a substituted or unsubstituted aryl group having 6 to 12 carbon atoms, provided that in the general formula (1), X ¹ bonded to b is a substituted or unsubstituted arylene group having 6 to 20 carbon atoms. The compound for organic electroluminescent elements according to claim 1, wherein X ¹ and X ² are each independently a single bond, a substituted or unsubstituted phenylene group, naphthylene group, or biphenylene group.   The compound for organic electroluminescent elements according to claim 1 or 2, wherein Ar is a substituted or unsubstituted phenylene group, naphthylene group, or biphenylene group. In an organic electroluminescent device in which one or more organic layers are sandwiched between a pair of electrodes composed of an anode and a cathode, at least one of the organic layers is represented by any one of the following general formulas (1) to (3). An organic electroluminescent device comprising the compound A to be used alone or as a component of a mixture.

(In the general formulas (1) to (3), X ¹ and X ² each independently represent a single bond or a substituted or unsubstituted arylene group having 6 to 20 carbon atoms, and X ¹ represents a position a, Bonded to any one of b, c and d, and X ² binds to any one of positions e, f, g and h, Ar represents a substituted or unsubstituted aryl group having 6 to 20 carbon atoms, R ¹ To R ⁴ are each independently a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms or a substituted or unsubstituted aryl group having 6 to 12 carbon atoms, provided that in the general formula (1), X ¹ bonded to b is a substituted or unsubstituted arylene group having 6 to 20 carbon atoms.   The organic electroluminescent device according to claim 4, wherein the organic layer has a light emitting layer, and the light emitting layer contains the compound A.   The organic electroluminescent device according to claim 5, wherein the light emitting layer has a host material and a dopant, and the host material contains the compound A. The organic electroluminescent element according to claim 6, wherein the dopant includes a compound B represented by the following general formula (4).

(In General Formula (4), Y ¹ is a substituted or unsubstituted aryl group having 6 to 12 carbon atoms or a substituted or unsubstituted nitrogen-containing aromatic heterocyclic group having 5 to 12 ring constituent elements. Y ^{2 to} Y ⁴ are each independently hydrogen, a substituted or unsubstituted aryl group having 6 to 12 carbon atoms, or a substituted or unsubstituted nitrogen-containing aromatic heterocyclic group having 5 to 12 ring constituent elements. However, at least one of Y ^{1 to} Y ⁴ is substituted with one or more substituted or unsubstituted nitrogen-containing aromatic heterocyclic groups having 5 to 12 ring constituent elements, or a cyano group or a trifluoromethyl group. It is an aryl group having 6 to 12 carbon atoms or a nitrogen-containing aromatic heterocyclic group having 5 to 12 ring constituent elements.) The organic electroluminescent device according to any one of claims 4 to 7, wherein the organic layer has a hole injection layer, and the hole injection layer contains the compound A and an electron acceptor compound.

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