JP2016092291A - Compound for organic electroluminescent element and organic electroluminescent element using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a compound for an organic electroluminescent element with a long life, and an organic electroluminescent element using the same.SOLUTION: The compound for an organic electroluminescent element is represented by general formula (1). (In the general formula (1), Arand Arare identically or each independently a substituted or unsubstituted 6-50C aryl group; k and l are each independently an integer of 2-4 satisfying 4≤k+l≤8; and adjacent two or more of Ars and Ars may be bonded together to form a ring.)SELECTED DRAWING: Figure 1

Description

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

  Organic electroluminescence devices have features such as self-luminance and high-speed response, and are expected to be applied to flat panel displays. In particular, since a two-layered type (laminated type) in which a hole-transporting organic thin film (hole-transporting layer) and an electron-transporting organic thin film (electron-transporting layer) are reported has been reported, a low voltage of 10 V or less. It has attracted attention as a large-area light-emitting element that emits light with voltage. A laminated organic electroluminescent element is composed of a thin film laminated film having a basic structure of positive electrode / hole injection layer / hole transport layer / light emitting layer / electron transport layer / electron injection layer / negative electrode. Among these, the light emitting layer may have the function of the hole transport layer and the electron transport layer as in the case of the two-layer type. Further, since various colors can be emitted by selecting the type of the fluorescent organic compound, application to various light emitting elements, display elements and the like is expected.

  In such an organic electroluminescence device, various device configurations and materials have been proposed in order to realize a long-life device. Among them, Patent Document 1 and Patent Document 2 show a technique for extending the lifetime of an organic electroluminescent element by capturing triplet excitons generated during the operation of the organic electroluminescent element. In this method, the triplet trapping material added in the organic electroluminescent element accumulates in the organic electroluminescent element, thereby reducing the concentration of triplet excitons that cause deterioration of the organic electroluminescent element. Although this is a technique for extending the lifetime of an organic electroluminescent device, a sufficient lifetime has not been obtained so far even if this technique is used.

  Patent Document 3 discloses a technique for capturing triplet excitons generated in an organic solid using cyclooctatetraene having a property of low minimum triplet energy.

  However, since cyclooctatetraene is a liquid at room temperature, an organic electroluminescent device composed of an organic thin film cannot be produced. Therefore, the method of trapping triplet excitons generated in an organic solid using cyclooctatetraene cannot be applied to an organic electroluminescent device that is an organic solid.

JP 2002-359080 A Special table 2013-539198 gazette Special table 2012-514862 gazette

  Therefore, an object of the present invention is to provide a compound for an organic electroluminescence device having a longer life and an organic electroluminescence device using the same.

  In the present invention, as a result of examining various material skeletons in order to achieve the above object, it has been found that the object can be achieved by a compound in which four or more aryl groups are substituted on cyclooctatetraene.

（一般式（１）において、Ａｒ^１とＡｒ^２は同一もしくはそれぞれ独立に置換または無置換の炭素数６〜５０のアリール基であり、ｋとｌは４≦ｋ＋ｌ≦８を満たすそれぞれ独立の２〜４の整数である。前記式（１）中、Ａｒ^１とＡｒ^２は、隣接する２個以上が互いに結合して環を形成してもよい。） That is, this invention is a compound for organic electroluminescent elements represented by following General formula (1).

(In the general formula (1), Ar ¹ and Ar ² are the same or independently substituted or unsubstituted aryl groups having 6 to 50 carbon atoms, and k and l are each independently 2 satisfying 4 ≦ k + l ≦ 8. It is an integer of ~ 4. In the formula (1), two or more adjacent Ar ¹ and Ar ² may be bonded to each other to form a ring.

Moreover, the organic electroluminescent device according to the present invention is an organic electroluminescent device in which at least one organic layer is sandwiched between a pair of electrodes composed of an anode and a cathode. It is preferable to contain the compound of general formula (1) as a component of the mixture. A long-life organic electroluminescence device can be realized by using the compound of the general formula (1) having high thin film stability in an organic electroluminescence device comprising at least one organic layer.

  Moreover, it is preferable that the organic electroluminescent element which concerns on this invention contains the component of a mixture in a light emitting layer or its adjacent layer. By incorporating the compound of the general formula (1) in the light emitting layer close to the position where the exciton exists or its adjacent layer, the triplet exciton can be efficiently captured, thereby realizing a long-life organic electroluminescence device. it can.

（一般式（２）において、Ａｒ^３〜Ａｒ^７は同一もしくはそれぞれ独立に置換または無置換の炭素数６〜５０のアリール基であり、ｍとｎは１≦ｍ＋ｎ≦６を満たすそれぞれ独立の０〜３の整数である。） In the organic electroluminescence device in which at least one organic layer is sandwiched between a pair of electrodes composed of an anode and a cathode, at least one of the organic layers is represented by the following general formula (2). It is preferable to contain the compound described above and the compound described in the general formula (1) as components of the mixture of the layers. In the compound described in the general formula (1), the cyclooctatetraene skeleton is an anti-aromatic ring, but has 4 to 8 aromatic rings, and thus has the following general formula (2 ) Can be captured and triplet excitons can be efficiently captured and deactivated, so that a long-life organic electroluminescence device can be realized.

(In General Formula (2), Ar ^{3 to} Ar ⁷ are the same or independently substituted or unsubstituted aryl groups having 6 to 50 carbon atoms, and m and n are each independently 0 satisfying 1 ≦ m + n ≦ 6. It is an integer of ~ 3.)

（一般式（３）において、Ａｒ^８〜Ａｒ^１２は同一もしくはそれぞれ独立に置換または無置換の炭素数６〜５０のアリール基であり、ｊは０〜２の整数である。）

（一般式（４）において、Ａｒ^１３、Ａｒ^１４は同一もしくはそれぞれ独立に置換または無置換の炭素数６〜５０のアリール基であり、Ｒ^１〜Ｒ^１０はそれぞれ水素、置換もしくは無置換のアルキル基、置換もしくは無置換のアリール基、置換もしくは無置換のアミノ基、置換もしくは無置換のアルコキシ基、置換もしくは無置換のアルキルチオ基、置換もしくは無置換のアリールオキシ基、置換もしくは無置換のアリールチオ基、置換もしくは無置換のアルケニル基、置換もしくは無置換のアラルキル基または置換もしくは無置換の複素環基を表し、これらは同一でも異なるものであってもよい。）

（一般式（５）において、Ｒ^１１〜Ｒ^２０はそれぞれ水素、置換もしくは無置換のアルキル基、置換もしくは無置換のアリール基、置換もしくは無置換のアミノ基、置換もしくは無置換のアルコキシ基、置換もしくは無置換のアルキルチオ基、置換もしくは無置換のアリールオキシ基、置換もしくは無置換のアリールチオ基、置換もしくは無置換のアルケニル基、置換もしくは無置換のアラルキル基または置換もしくは無置換の複素環基を表し、これらは同一でも異なるものであってもよい。） The organic electroluminescent device according to the present invention is an organic electroluminescent device in which at least one organic layer is sandwiched between a pair of electrodes composed of an anode and a cathode. The compound represented by the formula (3), the following general formula (4) or the following general formula (5) and the compound described in the above general formula (1) are preferably contained as components of the mixture of the layers. In the compound described in the general formula (1), the cyclooctatetraene skeleton is an anti-aromatic ring, but has 4 to 8 aromatic rings, and thus has the following general formula (3 ) Or a compound of the following general formula (4) or the following general formula (5), the triplet exciton can be efficiently captured and quenched, thereby realizing a long-life compound for an organic electroluminescent device. it can.

(In General Formula (3), Ar ^{8 to} Ar ¹² are the same or independently substituted or unsubstituted aryl groups having 6 to 50 carbon atoms, and j is an integer of 0 to 2.)

(In the general formula (4), Ar ¹³ and Ar ¹⁴ are the same or independently substituted or unsubstituted aryl groups having 6 to 50 carbon atoms, and R ^{1 to} R ¹⁰ are hydrogen, substituted or unsubstituted alkyl, respectively. Group, substituted or unsubstituted aryl group, substituted or unsubstituted amino group, substituted or unsubstituted alkoxy group, substituted or unsubstituted alkylthio group, substituted or unsubstituted aryloxy group, substituted or unsubstituted arylthio group A substituted or unsubstituted alkenyl group, a substituted or unsubstituted aralkyl group or a substituted or unsubstituted heterocyclic group, which may be the same or different.

(In the general formula (5), R ^{11 to} R ²⁰ are each hydrogen, substituted or unsubstituted alkyl group, substituted or unsubstituted aryl group, substituted or unsubstituted amino group, substituted or unsubstituted alkoxy group, substituted Or an unsubstituted alkylthio group, a substituted or unsubstituted aryloxy group, a substituted or unsubstituted arylthio group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted aralkyl group, or a substituted or unsubstituted heterocyclic group; These may be the same or different.)

  ADVANTAGE OF THE INVENTION According to this invention, the compound for organic electroluminescent elements with longer life and an organic electroluminescent element using the same can be provided.

1 is an outline of an organic electroluminescence device of the present invention.

（一般式（１）において、Ａｒ^１とＡｒ^２は同一もしくはそれぞれ独立に置換または無置換の炭素数６〜５０のアリール基であり、ｋとｌは４≦ｋ＋ｌ≦８を満たすそれぞれ独立の２〜４の整数である。前記式（１）中、Ａｒ^１とＡｒ^２は、隣接する２個以上が互いに結合して環を形成してもよい。） This embodiment is a compound for organic electroluminescent elements represented by the following general formula (1).

(In the general formula (1), Ar ¹ and Ar ² are the same or independently substituted or unsubstituted aryl groups having 6 to 50 carbon atoms, and k and l are each independently 2 satisfying 4 ≦ k + l ≦ 8. It is an integer of ~ 4. In the formula (1), two or more adjacent Ar ¹ and Ar ² may be bonded to each other to form a ring.

  Since unsubstituted cyclooctatetraene is a liquid at room temperature, an organic thin film containing it cannot be produced, but by substituting an aryl group for the cyclooctatetraene skeleton as in general formula (1), Since it becomes a solid state at room temperature, an organic thin film can be produced. In addition, substitution of the aryl group with the cyclooctatetraene skeleton increases the stability of the double bond of the cyclooctatetraene skeleton, and improves the stability against heat generated by driving the organic electroluminescence device, thereby extending the lifetime. It becomes the compound for organic electroluminescent elements. In addition, the organic electroluminescent device containing the compound of the general formula (1) can capture and deactivate triplet excitons generated by driving the organic electroluminescent device, thus realizing a long-life organic electroluminescent device. it can.

  In the general formula (1), k + 1 is preferably 4 or more in order to further improve the thermal stability against resistance heating during the vacuum deposition process and the stability against heat generated when driving the organic electroluminescent element. . Further, k + 1 is more preferably 4 or 8 because synthesis is easy. In addition, since the trapping and quenching of the triplet is performed by a change in the ring structure of the cyclooctatetraene skeleton, the number of substituents is small, and the smaller the size of the substituent, the more likely the change occurs. k + 1 is more preferably 4, and the substituent is more preferably a substituted or unsubstituted phenyl group.

In General Formula (1), Ar ¹ and Ar ² are the same or independently substituted or unsubstituted aryl groups having 6 to 50 carbon atoms, and have a low molecular weight such as a phenyl group, a biphenyl group, a terphenyl group, or a naphthyl group. The aryl group is preferable in that it can be easily synthesized. These substituents may be further substituted, 2-methylphenyl group, 3-methylphenyl group, 4-methylphenyl group, 2,3-dimethylphenyl group, 2,4-dimethylphenyl group, 2, 5-dimethylphenyl group, 2,6-dimethylphenyl group, 3,4-dimethylphenyl group, 3,5-dimethylphenyl group, 3,6-dimethylphenyl group, 4,5-dimethylphenyl group and the like are preferable.

  The molecular weight of the compound is not particularly limited, but is preferably 1000 or less in consideration of the film forming process. When the molecular weight exceeds 1000, synthesis becomes difficult due to a decrease in solubility, and the coating process for application to a device becomes difficult. Further, even when a device is produced by a vapor deposition process, the vapor deposition temperature is often a high temperature of 400 ° C. or higher, which may cause decomposition of the material.

  Specific examples of the compound of the present embodiment represented by the general formula (1) are shown below, but the cyclooctatetraene skeleton itself has a triplet capturing effect, and the effect does not depend on a substituent. The present embodiment is not limited to these.

  Moreover, it is preferable that this embodiment is an organic electroluminescent element characterized by including the compound of the said General formula (1). The organic electroluminescent element of this embodiment will be described with reference to FIG. As shown in FIG. 1, the organic electroluminescent device 1 includes an anode 3, a hole injection layer 4, a hole transport layer 5, a light emitting layer 6, an electron transport layer 7, an electron injection layer 8, and a cathode 9 on a substrate 2. In order. In addition, the compound of the general formula (1) may be contained in any layer, but in order to capture the triplet exciton generated in the light emitting layer within the diffusion length, the light emitting layer 6 or an adjacent layer thereof is used. More preferably, it is contained in a certain hole transport layer 5 or electron transport layer 7.

As shown in Patent Document 3, cyclooctatetraene exhibits non-vertical triplet energy transfer due to changes in its molecular skeleton. The lowest excited triplet energy is 0.8 eV, which is lower than the lowest excited triplet energy of anthracene, pyrene, naphthacene, and the like, which are typical material skeletons for organic electroluminescence devices. For example, when calculating the lowest excited triplet energy by molecular orbital calculation, the lowest excited triplet energy of anthracene is 1.8 eV, the lowest excited triplet energy of pyrene is 2.2 eV, and the lowest excited triplet energy of naphthacene is It was 1.2 eV. As a calculation method, a quantum chemical calculation at a B3LYP / 6-31G + level was used by using a density functional theory (Density Functional Theory).

The compound of the general formula (1) also has a low lowest excited triplet energy like cyclooctatetraene. For example, when the lowest excited triplet energy of Q1 is calculated by molecular orbital calculation, 0.7 eV Met. As a calculation method, a quantum chemical calculation at a B3LYP / 6-31G + level was used by using a density functional theory (Density Functional Theory).

By utilizing the property that the minimum excitation triplet excitation energy of the compound of the general formula (1) is low as described above, the excited triplet energy generated in the organic electroluminescence device is converted into the general formula (1). It can be quickly captured by the compound.

  The substrate 2 is preferably formed of a transparent or translucent material, such as a glass plate, a transparent plastic sheet, a translucent plastic sheet, quartz, transparent ceramics, or a composite sheet combining these. The substrate 2 may be formed from an opaque material. In this case, the organic electroluminescent element 1 should just reverse the lamination | stacking order shown by FIG. Furthermore, the emission color may be controlled by combining the substrate 2 with, for example, a color filter film, a color conversion film, a dielectric reflection film, or the like.

  The anode 3 preferably uses a metal, an alloy or an electrically conductive compound having a relatively large work function as an electrode material. Examples of the electrode material used for the anode 3 include gold, platinum, silver, copper, cobalt, nickel, palladium, vanadium, tungsten, tin oxide, zinc oxide, ITO (Indium Tin Oxide), polythiophene, and polypyrrole. These electrode materials may be used alone or in combination. The anode 3 can form these electrode materials on the substrate 2 by, for example, a vapor phase growth method such as a vapor deposition method or a sputtering method. Further, the anode 3 may have a single layer structure or a multilayer structure.

  The hole injection layer 4 is a layer containing a compound having a function of facilitating injection of holes from the anode 3. In addition, adhesion with the anode 3 is also an important factor when selecting a material. Specifically, it can be formed using at least one phthalocyanine derivative, triarylmethane derivative, triarylamine derivative, or the like.

  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 from being injected into the hole transport layer 5. is there. The hole transport layer 5 includes at least one hydrocarbon compound such as a triarylmethane derivative, a triarylamine derivative, a stilbene derivative, a polysilane derivative, polyphenylenevinylene and a derivative thereof, polythiophene and a derivative thereof, a carbazole derivative, or an anthracene derivative. Can be formed. Moreover, the compound represented by General formula (1) of this invention may be contained in the positive hole transport layer 5, and the positive hole transport layer 5 is General formula (2) or General formula (3) or General formula (4). ) Or general formula (5) is more preferably used. When the concentration of the compound represented by the general formula (1) is high, the luminous efficiency is lowered. Therefore, the concentration of the compound represented by the general formula (1) in this case is preferably 20% by weight or less, and preferably 10% by weight or less. More preferred.

  Although the specific example of the compound of this embodiment represented by General formula (2) below is shown, this embodiment is not limited to these.

  Moreover, although the specific example of the compound of this embodiment represented by General formula (3) below is shown, this embodiment is not limited to these.

  Moreover, although the specific example of the compound of this embodiment represented by General formula (4) below is shown, this embodiment is not limited to these.

  Moreover, although the specific example of the compound of this embodiment represented by General formula (5) below is shown, this embodiment is not limited to these.

  In addition, if it is a material which has the function of the positive hole injection layer 4 and the positive hole transport layer 5, as a positive 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.

  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. Hydrocarbon compounds such as naphthalene derivatives, anthracene derivatives, phenanthrene derivatives, pyrene derivatives, fluoranthene derivatives, and naphthacene derivatives are preferably used.

  In addition to the host material, the light emitting layer 6 may contain another fluorescent substance as a light emitting doping material. Examples of fluorescent substances include compounds such as quinacridone, rubrene, and styryl dyes, quinoline derivatives such as metal complex dyes having 8-quinolinol or a derivative thereof such as tris (8-quinolinolato) aluminum as a ligand, tetraphenyl, and the like. Examples thereof include butadiene, anthracene, fluoranthene, pyrene, perylene, coronene, 12-phthaloperinone derivatives, phenylanthracene derivatives, tetraarylethene derivatives, aromatic amine derivatives, and the like. In particular, aromatic amine derivatives such as aminonaphthalene derivatives, aminopyrene derivatives, aminophenanthrene derivatives, aminofluorene derivatives, aminochrysene derivatives, aminoanthracene derivatives, and aminoperylene derivatives are very preferable materials.

  The light emitting layer 6 may contain other compounds in addition to the host material and the light emitting doping material. It can be used by adjusting the transport of carriers by mixing other compounds, or by changing the emission color by mixing fluorescent dyes. Examples of compounds that regulate carrier transport include electron transport such as 8-quinolinol such as tris (8-quinolinolato) aluminum or its derivatives, quinoxaline derivatives, pyridine derivatives, pyrimidine derivatives, imidazopyridine derivatives, imidazopyrimidine derivatives, phenanthroline derivatives, and the like. Or a hole transporting compound such as a triarylamine derivative can be preferably used. The compound represented by the general formula (1) in the present embodiment is preferably contained in the light emitting layer 6, and the light emitting layer 6 has the general formula (2), the general formula (3), the general formula (4), or the general formula ( More preferably, it is formed using at least one compound represented by 5). When the concentration of the compound represented by the general formula (1) is high, the luminous efficiency is lowered. Therefore, the concentration of the compound represented by the general formula (1) in this case is preferably 20% by weight or less, and preferably 10% by weight or less. More preferred.

  The electron transport layer 7 has a function of transporting injected electrons and a function of preventing holes from being injected from the light emitting layer 6. Is an organometallic complex having an 8-quinolinol or its derivative such as tris (8-quinolinolato) aluminum as a ligand, oxadiazole derivative, triazole derivative, triazine derivative, quinoline derivative, quinoxaline derivative, diphenylquinone derivative, nitro Formed by using at least one kind of substituted fluorenone derivatives, thiopyrandioxide derivatives, pyridine derivatives, pyrimidine derivatives, imidazopyridine derivatives, imidazopyrimidine derivatives, phenanthroline derivatives and other heterocyclic compounds, anthracene derivatives and fluoranthene derivatives. can do. Moreover, the compound represented by General formula (1) of this embodiment may be contained in the electron carrying layer 7, and the electron carrying layer 7 is General formula (2) or General formula (3) or General formula (4). Or it is more preferable to form using at least 1 type of the compound represented by General formula (5). When the concentration of the compound represented by the general formula (1) is high, the luminous efficiency is lowered. Therefore, the concentration of the compound represented by the general formula (1) in this case is preferably 20% by weight or less, and preferably 10% by weight or less. More preferred.

  The electron injection layer 8 has a function of facilitating injection of electrons from the cathode 9 and a function of improving adhesion with the cathode 9. The electron injection layer 8 is composed of an organometallic complex having an 8-quinolinol or its derivative such as tris (8-quinolinolato) aluminum as a ligand, oxadiazole derivative, triazole derivative, triazine derivative, quinoline derivative, quinoxaline derivative, diphenyl A quinone derivative, a nitro-substituted fluorenone derivative, a thiopyrandioxide derivative, a pyridine derivative, a pyrimidine derivative, an imidazopyridine derivative, an imidazopyrimidine derivative, a phenanthroline derivative, or the like can be used.

  For the cathode 9, a metal having a relatively small work function and a salt thereof, an alloy, or an electrically conductive compound can be used as an electrode constituent material. For example, lithium, sodium, calcium, magnesium, indium, ruthenium, titanium, manganese, yttrium, aluminum as metal, lithium oxide, sodium oxide, calcium oxide, magnesium oxide as oxide, lithium fluoride, fluoride as fluoride Sodium, calcium fluoride, magnesium fluoride, alloys include lithium-indium alloy, sodium-potassium alloy, magnesium-silver alloy, magnesium-indium alloy, aluminum-lithium alloy, aluminum-calcium alloy, aluminum-magnesium alloy, electrical conduction Examples of the functional compound include a graphite thin film.

  These electrode constituent materials may be used alone or in combination. The cathode 9 can be formed of these electrode materials on the electron injection layer 8 by a method such as vapor deposition, sputtering, ionized vapor deposition, ion plating, or cluster ion beam. Further, the cathode 9 may have a single layer structure or a multilayer structure. In order to efficiently extract light emitted from the organic electroluminescent device, at least one of the anode 3 and the cathode 9 is preferably transparent or translucent, and generally has a light transmittance of 80% or more. More preferably, the material and thickness of the anode 3 or the cathode 9 are set.

  The organic electroluminescent element is often formed by a vapor deposition process, but the compound represented by the general formula (1) in the present embodiment has high solubility and can be sufficiently formed even by a coating process. is there. Therefore, the cost of the process can be reduced by using the compound of the present invention. As the coating solvent, a hydrocarbon solvent such as toluene or xylene, or a halogen solvent such as dichloroethane can be used. As a film forming method, a spin coating method, various printing methods such as gravure printing, an ink jet method, or the like can be used.

  Hereinafter, specific synthesis examples of the compound of the present invention will be shown to explain the present invention in more detail.

Synthesis Example 1 Synthesis of Exemplified Compound Q12 2.5 g (14 mmol) of o-ethynylbiphenyl was dissolved in dehydrated diethyl ether, 130 mg (18.5 mmol) of lithium was added, and the mixture was reacted at room temperature for 6 hours. It was. The reaction solution was added to diethyl ether in which 1.23 g (5 mmol) iodine was dissolved, and the mixture was stirred for 10 minutes. The precipitated solid was filtered and washed with THF to obtain 55 mg (0.08 mmol) of Q12. The yield was 2.2%. When APCI-MS of the obtained solid was measured, m / z = 712 was obtained with respect to C56H40 = 712. Thus, this compound was identified as Q12.

Synthesis Example 2 Synthesis of Exemplified Compound Q13 2.1 g (14 mmol) of 1-ethynylnaphthalene was dissolved in dehydrated diethyl ether, 130 mg (18.5 mmol) of lithium was added, and the mixture was reacted at room temperature for 6 hours. It was. The reaction solution was added to diethyl ether in which 1.23 g (5 mmol) iodine was dissolved, and the mixture was stirred for 10 minutes. The precipitated solid was filtered and washed with THF to obtain 103 mg (0.17 mmol) of Q13. The yield was 4.8%. When APCI-MS of the obtained solid was measured, m / z = 608 was obtained with respect to C48H32 = 608. Therefore, this compound was identified as Q13.

Synthesis Example 3 Synthesis of Exemplified Compound Q16 2.9 g (14 mmol) of bis (p-tolyl) acetylene was dissolved in dehydrated diethyl ether, and 130 mg (18.5 mmol) of lithium was added. Reacted for hours. The reaction solution was added to diethyl ether in which 1.23 g (5 mmol) iodine was dissolved, and the mixture was stirred for 10 minutes. The precipitated solid was filtered and washed with THF to obtain 240 mg (0.29 mmol) of Q16. The yield was 8.3%. When APCI-MS of the obtained solid was measured, m / z = 824 was obtained with respect to C64H56 = 824. Therefore, this compound was identified as Q16.

Synthesis Example 4 Synthesis of Exemplified Compound Q17 2.9 g (14 mmol) of bis (m-tolyl) acetylene was dissolved in dehydrated diethyl ether, 130 mg (18.5 mmol) of lithium was added, and 8 at room temperature was added. Reacted for hours. The reaction solution was added to diethyl ether in which 1.23 g (5 mmol) iodine was dissolved, and the mixture was stirred for 10 minutes. The precipitated solid was filtered and washed with THF to obtain 212 mg (0.25 mmol) of Q17. The yield was 7.3%. When APCI-MS of the obtained solid was measured, m / z = 824 was obtained with respect to C64H56 = 824. Therefore, this compound was identified as Q17.

Synthesis Example 5 Synthesis of Exemplified Compound Q18 2.9 g (14 mmol) of bis (o-tolyl) acetylene was dissolved in dehydrated diethyl ether, 130 mg (18.5 mmol) of lithium was added, and 8 at room temperature was added. Reacted for hours. The reaction solution was added to diethyl ether in which 1.23 g (5 mmol) iodine was dissolved, and the mixture was stirred for 10 minutes. The precipitated solid was filtered and washed with THF to obtain 290 mg (0.35 mmol) of Q18. The yield was 10.1%. When APCI-MS of the obtained solid was measured, m / z = 824 was obtained with respect to C64H56 = 824. Therefore, this compound was identified as Q18.

Synthesis Example 6 Synthesis of Exemplified Compound Q19 3.3 g (14 mmol) of bis (3,5 dimethylphenyl) acetylene was dissolved in dehydrated diethyl ether, 130 mg (18.5 mmol) of lithium was added, and For 8 hours. The reaction solution was added to diethyl ether in which 1.23 g (5 mmol) iodine was dissolved, and the mixture was stirred for 10 minutes. The precipitated solid was filtered and washed with THF to obtain 184 mg (0.20 mmol) of Q19. The yield was 5.6%. When APCI-MS of the obtained solid was measured, m / z = 937 was obtained with respect to C72H72 = 937. Thus, this compound was identified as Q19.

  Hereinafter, specific examples of the present invention will be shown together with comparative examples, and the present invention will be described in more detail.

(Examples 1-6, Comparative Example 1)
An ITO transparent electrode thin film 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 tank was depressurized to 1 × 10 ⁻⁴ Pa or less.

  Next, while maintaining the reduced pressure state, Chemical Formula 12 having the following structure was deposited at a deposition rate of 0.1 nm / sec to a thickness of 50 nm to form a hole injection layer.

  Next, Chemical Formula 13 having the following structure was deposited at a deposition rate of 0.1 nm / sec to a thickness of 10 nm to form a hole transport layer.

  Further, while maintaining the reduced pressure state, the chemical structure of the following structure as the host material, the chemical structure of the following structure as the luminescent dopant, and the compound of the present invention, Q12, Q13, Q16, Q17, Q18, or Q19, in a volume ratio of 96. : 3: 1 was deposited to a thickness of 40 nm at an overall deposition rate of 0.1 nm / sec to form a light emitting layer.

  Next, while maintaining the reduced pressure state, Chemical Formula 14 was deposited at 10 nm, followed by tris (8-hydroxyquinoline) aluminum (Alq3) at 5 nm and a deposition rate of 0.1 nm / sec to form an electron transport layer.

  Next, LiF was deposited at a deposition rate of 0.1 nm / sec to a thickness of 0.5 nm to form an electron injection electrode, Al was deposited as a protective electrode to 100 nm, and finally glass sealed to obtain an organic electroluminescent device. .

  Table 1 shows the test results of the initial luminance and the luminance half time of the device in which Q12, Q13, Q16, Q17, Q18, or Q19, which is the compound of this embodiment, is mixed in the light emitting layer. As a comparative example, the case where Q12 or Q13 or Q16 or Q17 or Q18 or Q19, which is the compound of the present invention, was not mixed in the light emitting layer was similarly shown.

The test was performed by applying a direct current having a current density of 10 mA / cm ² . When Q12, which is the compound of the present invention, was mixed in the light emitting layer, blue light emission derived from a light emitting dopant having an initial luminance of 420 cd / m ² and a luminance half life of 2250 hours was obtained.

As shown in Table 1, when the compound of this embodiment is mixed in the light emitting layer, triplet excitons generated by recombination of electrons and holes are captured, and a long-life organic electroluminescent device is obtained.

(Examples 7 to 12, Comparative Example 2)
An ITO transparent electrode thin film 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 tank was depressurized to 1 × 10 ⁻⁴ Pa or less.

  Next, while maintaining the reduced pressure state, Chemical Formula 12 was deposited to a film thickness of 50 nm at a deposition rate of 0.1 nm / sec to form a hole injection layer.

  Next, chemical compound 13 and Q12 or Q13 or Q16 or Q17 or Q18 or Q19, which are the compounds of the present invention, are vapor-deposited at a volume ratio of 95: 5 to a thickness of 10 nm at an overall vapor deposition rate of 0.1 nm / sec. A hole transport layer was formed.

  Further, while maintaining the reduced pressure state, the chemical compound 14 as the host material and the chemical compound 15 as the luminescent dopant were vapor-deposited at a volume ratio of 97: 3 at a total deposition rate of 0.1 nm / sec to a thickness of 40 nm. did.

  Next, while maintaining the reduced pressure state, Chemical Formula 14 was deposited at 10 nm, followed by tris (8-hydroxyquinoline) aluminum (Alq3) at 5 nm and a deposition rate of 0.1 nm / sec to form an electron transport layer.

  Next, LiF was deposited at a deposition rate of 0.1 nm / sec to a thickness of 0.5 nm to form an electron injection electrode, Al was deposited as a protective electrode to 100 nm, and finally glass sealed to obtain an organic electroluminescent device. .

  Table 2 shows the test results of the initial luminance and the luminance half-life time of the device in which Q12, Q13, Q16, Q17, Q18, or Q19, which is the compound of this embodiment, was mixed in the hole transport layer. As a comparative example, the case where Q12 or Q13 or Q16 or Q17 or Q18 or Q19, which is the compound of the present invention, is not mixed in the hole transport layer was similarly shown.

The test was performed by applying a direct current having a current density of 10 mA / cm ² . When Q12 which is the compound of the present invention was mixed in the hole transport layer, blue light emission derived from a light emitting dopant having an initial luminance of 400 cd / m ² and a luminance half life of 2700 hours was obtained.

As shown in Table 2, when the compound of this embodiment is mixed in the hole transport layer, triplet excitons generated by recombination of electrons and holes are captured, and a long-life organic electroluminescence device is obtained.

(Examples 13 to 18, Comparative Example 3)
An ITO transparent electrode thin film 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 tank was depressurized to 1 × 10 ⁻⁴ Pa or less.

  Next, while maintaining the reduced pressure state, Chemical Formula 12 was deposited to a film thickness of 50 nm at a deposition rate of 0.1 nm / sec to form a hole injection layer.

  Next, Chemical Formula 13 was deposited at a deposition rate of 0.1 nm / sec to a thickness of 10 nm to form a hole transport layer.

  Further, while maintaining the reduced pressure state, the chemical compound 14 as the host material and the chemical compound 15 as the luminescent dopant were vapor-deposited at a volume ratio of 97: 3 at a total deposition rate of 0.1 nm / sec to a thickness of 40 nm. did.

  Next, while maintaining the reduced pressure state, the chemical ratio 14 was changed to 10 nm, followed by tris (8-hydroxyquinoline) aluminum (Alq3) and the compound of the present invention Q12 or Q13 or Q16 or Q17 or Q18 or Q19. The film was deposited at a thickness of 95: 5 at a total deposition rate of 0.1 nm / sec to a thickness of 5 nm to form an electron transport layer.

  Next, LiF was deposited at a deposition rate of 0.1 nm / sec to a thickness of 0.5 nm to form an electron injection electrode, Al was deposited as a protective electrode to 100 nm, and finally glass sealed to obtain an organic electroluminescent device. .

  Table 3 shows the test results of the initial luminance and the luminance half-life time of the device in which Q12, Q13, Q16, Q17, Q18, or Q19, which is the compound of this embodiment, was mixed in the electron transport layer. As a comparative example, the case where the compound of the present invention, Q12, Q13, Q16, Q17, Q18, or Q19, was not mixed in the electron transport layer was similarly shown.

The test was performed by applying a direct current having a current density of 10 mA / cm ² . When Q12, which is the compound of the present invention, was mixed in the electron transport layer, blue light emission derived from a light emitting dopant having an initial luminance of 400 cd / m ² and a luminance half life of 2400 hours was obtained.

As shown in Table 3, when the compound of this embodiment is mixed in the electron transport layer, triplet excitons generated by recombination of electrons and holes are captured, and a long-life organic electroluminescence device is obtained.

(Examples 19 to 24, Comparative Example 4)
Organic electroluminescent elements were obtained in the same manner as in Examples 1 to 6, except that chemical formula 14 was changed to chemical formula 16 having the following structure.

  Table 4 shows the test results of the initial luminance and luminance half-life of the device in which the compound of the present invention, Q12, Q13, Q16, Q17, Q18 or Q19, was mixed in the light emitting layer. As a comparative example, the case where Q12 or Q13 or Q16 or Q17 or Q18 or Q19, which is the compound of the present invention, was not mixed in the light emitting layer was similarly shown.

The test was performed by applying a direct current having a current density of 10 mA / cm ² . When Q12 which is the compound of the present invention was mixed in the light emitting layer, blue light emission derived from a light emitting dopant having an initial luminance of 420 cd / m ² and a luminance half life of 2900 hours was obtained.

As shown in Table 4, when the compound of the present invention is mixed in the electron transport layer, triplet excitons generated by recombination of electrons and holes are captured, and a long-life organic electroluminescence device is obtained.

(Examples 25 to 30, Comparative Example 5)
Organic electroluminescent elements were obtained in the same manner as in Examples 1 to 6, except that the chemical formula 14 of the light emitting layer was changed to chemical formula 17 of the following structure and chemical formula 15 was changed to chemical formula 18 of the following structure.

  Table 5 shows the test results of the initial luminance and the luminance half time of the device in which Q12, Q13, Q16, Q17, Q18, or Q19, which is the compound of this embodiment, is mixed in the light emitting layer. As a comparative example, the case where Q12 or Q13 or Q16 or Q17 or Q18 or Q19, which is the compound of the present invention, was not mixed in the light emitting layer was similarly shown.

The test was performed by applying a direct current having a current density of 10 mA / cm ² . When Q12, which is the compound of the present invention, was mixed in the light emitting layer, red light emission derived from a light emitting dopant having an initial luminance of 780 cd / m ² and a luminance half life of 4650 hours was obtained.

As shown in Table 5, when the compound of this embodiment is mixed in the electron transport layer, triplet excitons generated by recombination of electrons and holes are captured, and a long-life organic electroluminescence device is obtained.

  As described above, the compound according to the present invention is useful as a compound for a long-life organic electroluminescence device. An organic electroluminescent element utilizing this can be applied to a light emitting device such as a display or illumination.

DESCRIPTION OF SYMBOLS 1 Organic electroluminescent element 2 Substrate 3 Anode 4 Hole injection layer 5 Hole transport layer 6 Light emitting layer 7 Electron transport layer 8 Electron injection layer 9 Cathode

Claims (5)

The compound for organic electroluminescent elements represented by following General formula (1).

(In the general formula (1), Ar ¹ and Ar ² are the same or independently substituted or unsubstituted aryl groups having 6 to 50 carbon atoms, and k and l are each independently 2 satisfying 4 ≦ k + l ≦ 8. It is an integer of ~ 4. In the formula (1), two or more adjacent Ar ¹ and Ar ² may be bonded to each other to form a ring.   In the organic electroluminescent element in which at least one organic layer is sandwiched between a pair of electrodes composed of an anode and a cathode, at least one of the organic layers contains the compound according to claim 1 as a component of the mixture. An organic electroluminescent element characterized by comprising:   The organic electroluminescent element according to claim 2, wherein the component of the mixture is contained in the light emitting layer or an adjacent layer thereof. In an organic electroluminescent device in which at least one organic layer is sandwiched between a pair of electrodes composed of an anode and a cathode, at least one of the organic layers is a compound represented by the following general formula (2), An organic electroluminescent device comprising the compound according to item 1 as a component of the mixture of the layers.

(In General Formula (2), Ar ^{3 to} Ar ⁷ are the same or independently substituted or unsubstituted aryl groups having 6 to 50 carbon atoms, and m and n are each independently 0 satisfying 1 ≦ m + n ≦ 6. It is an integer of ~ 3.) In an organic electroluminescence device in which at least one organic layer is sandwiched between a pair of electrodes composed of an anode and a cathode, at least one of the organic layers is represented by the following general formula (3) or the following general formula (4) or The organic electroluminescent element characterized by containing the compound represented by following General formula (5), and the compound of Claim 1 as a component of the mixture of the layer.

(In General Formula (3), Ar ^{8 to} Ar ¹² are the same or independently substituted or unsubstituted aryl groups having 6 to 50 carbon atoms, and j is an integer of 0 to 2.)

(In the general formula (4), Ar ¹³ and Ar ¹⁴ are the same or independently substituted or unsubstituted aryl groups having 6 to 50 carbon atoms, and R ^{1 to} R ¹⁰ are hydrogen, substituted or unsubstituted alkyl, respectively. Group, substituted or unsubstituted aryl group, substituted or unsubstituted amino group, substituted or unsubstituted alkoxy group, substituted or unsubstituted alkylthio group, substituted or unsubstituted aryloxy group, substituted or unsubstituted arylthio group A substituted or unsubstituted alkenyl group, a substituted or unsubstituted aralkyl group or a substituted or unsubstituted heterocyclic group, which may be the same or different.

(In the general formula (5), R ^{11 to} R ²⁰ are each hydrogen, substituted or unsubstituted alkyl group, substituted or unsubstituted aryl group, substituted or unsubstituted amino group, substituted or unsubstituted alkoxy group, substituted Or an unsubstituted alkylthio group, a substituted or unsubstituted aryloxy group, a substituted or unsubstituted arylthio group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted aralkyl group, or a substituted or unsubstituted heterocyclic group; These may be the same or different.)

Images