KR100970399B1 - Heterocyclic compound and organic light emitting device comprising the same - Google Patents

Abstract

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상기식 중, 탄소수 6 내지 16의 치환 또는 비치환된 아릴렌 또는 헤테로아릴렌이며;
Ar₂ 및 Ar₃은, 각각 독립적으로, 탄소수 6 내지 20의 치환 또는 비치환된 아릴기, 탄소수 4 내지 20의 치환 또는 비치환된 헤테로아릴기 또는 탄소수 6 내지 20의 치환 또는 비치환된 축합 다환기를 나타내며;
Ar₄는 탄소수 6 내지 20의 치환 또는 비치환된 아릴기, 탄소수 6 내지 20의 치환 또는 비치환된 아릴옥시기, 탄소수 4 내지 20의 치환 또는 비치환된 헤테로아릴기 또는 탄소수 6 내지 20의 치환 또는 비치환된 축합 다환기를 나타내며;
Ar₁ 와 Ar₃, 또는 Ar₂ 와 Ar₃는 서로 연결되어 고리를 형성할 수 있다.
본 발명의 헤테로고리 화합물은 우수한 전기적 특성 및 전하수송 능력을 갖고 있어, 적색, 녹색, 청색, 흰색 등의 모든 칼라의 형광과 인광 소자에 적합한 정공주입 재료, 정공수송 재료 및/또는 발광 재료로 유용하며, 이를 이용하여 고효율, 저전압, 고휘도, 장수명의 유기 전계 발광 장치를 제작할 수 있다.The present invention provides a heterocyclic compound represented by Formula 1:
[Formula 1]

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In the above formula, substituted or unsubstituted arylene or heteroarylene having 6 to 16 carbon atoms;
Ar ₂ and Ar ₃ are each independently a substituted or unsubstituted aryl group having 6 to 20 carbon atoms, a substituted or unsubstituted heteroaryl group having 4 to 20 carbon atoms, or a substituted or unsubstituted condensed group having 6 to 20 carbon atoms. Indicates ventilation;
Ar ₄ is a substituted or unsubstituted aryl group having 6 to 20 carbon atoms, a substituted or unsubstituted aryloxy group having 6 to 20 carbon atoms, a substituted or unsubstituted heteroaryl group having 4 to 20 carbon atoms or a substituted 6 to 20 carbon atoms Or an unsubstituted condensed polycyclic group;
Ar ₁ and Ar ₃ , or Ar ₂ and Ar ₃ may be connected to each other to form a ring.
The heterocyclic compound of the present invention has excellent electrical properties and charge transport ability, and is useful as a hole injection material, a hole transport material and / or a luminescent material suitable for fluorescence and phosphorescent devices of all colors such as red, green, blue, and white. By using this, an organic electroluminescent device with high efficiency, low voltage, high brightness, and long life can be manufactured.

Description

Heterocyclic compound and organic light emitting device comprising the same

The present invention relates to a heterocyclic compound and an organic electroluminescent device using the same, and more particularly, to an organic electroluminescent device employing a heterocyclic compound having high color purity and high electrical stability and an organic film including the same.

Electroluminescent devices (electroluminescent devices) are a self-luminous display device is attracting great attention because of the advantages of a wide viewing angle, excellent contrast and fast response time. The organic electroluminescent device is classified into an inorganic electroluminescent device using an inorganic compound in an emitting layer and an organic electroluminescent device using an organic compound, among which an organic electroluminescent device is particularly used in an inorganic electroluminescent device. Compared to the above, many studies have been conducted in that the characteristics of luminance, driving voltage and response speed are excellent and multicoloring is possible.

The organic electroluminescent device generally has a stacked structure of an anode / organic light emitting layer / cathode, and further includes a hole injection layer and / or a hole transport layer and an electron injection layer between the anode and the light emitting layer or between the light emitting layer and the cathode to form an anode / hole transport layer. / Organic light emitting layer / cathode, anode / hole transport layer / organic light emitting layer / electron transport layer / cathode and the like.

Polyphenyl compounds or anthracene derivatives are well known as the hole transport layer forming material (US Pat. Nos. 6,596,415 and 6,465,115). However, organic electroluminescent devices made of a hole injection layer and / or a hole transport layer forming material known to date have a lot of room for improvement because they do not reach satisfactory life, efficiency and power consumption characteristics.

The technical problem to be achieved by the present invention is an organic film material having electrical stability, high charge transport ability, high glass transition temperature, and suitable for fluorescent and phosphorescent devices of all colors such as red, green, blue, and white. It is to provide a heterocyclic compound.

In addition, another technical problem to be achieved by the present invention is to provide an organic electroluminescent device having high efficiency, low voltage, high brightness, long life by employing the organic film including the heterocyclic compound.

In order to achieve the above technical problem, the present invention provides a heterocyclic compound represented by the following formula (1):

Wherein Ar ₁ is substituted or unsubstituted arylene or heteroarylene having 6 to 16 carbon atoms;

Ar ₂ and Ar ₃ are each independently a substituted or unsubstituted aryl group having 6 to 20 carbon atoms, a substituted or unsubstituted heteroaryl group having 4 to 20 carbon atoms, or a substituted or unsubstituted condensed group having 6 to 20 carbon atoms. Indicates ventilation;

Ar ₄ is a substituted or unsubstituted aryl group having 6 to 20 carbon atoms, a substituted or unsubstituted aryloxy group having 6 to 20 carbon atoms, a substituted or unsubstituted heteroaryl group having 4 to 20 carbon atoms or a substituted 6 to 20 carbon atoms Or an unsubstituted condensed polycyclic group; And

Ar ₁ and Ar ₃ , or Ar ₂ and Ar ₃ may be connected to each other to form a ring.

In order to achieve the above technical problem, the present invention provides an organic electroluminescent device having an organic film positioned between a first electrode and a second electrode, wherein the organic film includes the aforementioned heterocyclic compound. Provided is a light emitting device.

According to an embodiment of the present invention, the organic layer may be a single layer or a light emitting layer having a hole injection layer, a hole transport layer, a hole injection and a hole transport function at the same time.

The heterocyclic compound according to the present invention has excellent electrical properties and charge transport ability, and thus is useful as a hole injection material, a hole transport material and / or a light emitting material suitable for fluorescence and phosphorescent devices of all colors such as red, green, blue, and white. By using this, an organic electroluminescent device with high efficiency, low voltage, high brightness, and long life can be manufactured.

1 is a view showing the structure of an organic electroluminescent device according to an embodiment of the present invention.

The present invention is a heterocyclic compound represented by the following formula (1) is a compound having a novel structure in which two pyrrole rings are condensed on one benzene ring, and the heterocyclic compound is an organic film such as a hole injection layer, a hole transport layer, a light emitting layer An organic electroluminescent device used as a forming material is provided.

[Formula 1]

Wherein Ar ₁ is substituted or unsubstituted arylene or heteroarylene having 6 to 16 carbon atoms;

Ar ₂ and Ar ₃ are each independently a substituted or unsubstituted aryl group having 6 to 20 carbon atoms, a substituted or unsubstituted heteroaryl group having 4 to 20 carbon atoms, or a substituted or unsubstituted condensed group having 6 to 20 carbon atoms. Indicates ventilation;

Ar ₄ is a substituted or unsubstituted aryl group having 6 to 20 carbon atoms, a substituted or unsubstituted aryloxy group having 6 to 20 carbon atoms, a substituted or unsubstituted heteroaryl group having 4 to 20 carbon atoms or a substituted 6 to 20 carbon atoms Or an unsubstituted condensed polycyclic group; And

Ar ₁ and Ar ₃ , or Ar ₂ and Ar ₃ may be connected to each other to form a ring.

The carbon number of Ar ₁ , Ar ₂ , Ar ₃ and Ar ₄ is selected from 4 to 20 so that the compound of Formula 1 may be easily deposited by having an appropriate molecular weight.

Specific examples of the unsubstituted arylene or heteroarylene applied as Ar ₁ of Formula 1 include phenylene, biphenylene, thiophenylene, pyridinylene, pyrrolylene and fluorenylene. At least one hydrogen of the arylene or heteroarylene may be substituted with a halogen atom, a cyano group, an alkyl group of C1-C5, and an alkoxy group of C1-C5. Preferably Ar ₁ is selected from phenylene or biphenylene.

Unsubstituted aryl groups applied as Ar ₂ , Ar ₃ and Ar ₄ of Formula 1 are used alone or in combination to mean aromatic carbon rings having 6 to 20 carbon atoms containing at least one ring, said rings being pendant May be attached together or fused together. Examples of unsubstituted aryl groups include phenyl, biphenyl, triphenyl, pentaphenyl and the like. At least one hydrogen atom of the aryl group may be substituted with an alkyl group of C1-C5, an alkoxy group of C1-C5, an aryl group of C6-C14, an aryloxy group of C6-C20, a halogen atom, an amino group, a cyano group, or the like. . Specific examples of the aryl group that can be applied to the general formula (1) include phenyl group, ethylphenyl group, biphenyl group, ethylbiphenyl group, dimethyl o-, m- and p-fluorophenyl group, dichlorophenyl group, dicyanophenyl group, trifluoromethoxyphenyl group, o-, m-, and p-tolyl groups, mesityl groups, phenoxyphenyl groups, mesityryl groups, (α, α-dimethylbenzene) phenyl groups, (N, N'-dimethyl) aminophenyl groups, (N, N'- Diphenyl) aminophenyl group and the like, but is not limited thereto.

Examples of the unsubstituted heteroaryl group applied to the formula (1) include furanyl, pyridinyl, thiophenyl and the like. At least one hydrogen atom of the heteroaryl group may be substituted with an alkyl group of C1-C5.

Examples of the unsubstituted condensed polycyclic group applied to the formula (1) include pentarenyl group, naphthyl group, azurenyl group, heptarenyl group, acenaphthyl group, anthryl group, phenanthryl group, anthraquinolyl group, fluorenyl group, carba Sleepy groups and the like. At least one hydrogen of the condensed polycyclic group may be substituted with an alkyl group of C1-C5, an alkoxy group of C1-C5, an aryl group of C6-C14, an aryloxy group of C6-C20, a halogen atom, an amino group, a cyano group, or the like. . Specific examples of the condensed polycyclic group to be applied to the general formula (1) include pentarenyl group, naphthyl group, methylnaphthyl group, anthracenyl group, azurenyl group, heptarenyl group, acenaphthylenyl group, fluorenyl group, 9,9-dimethylflu Orenyl group, anthraquinolyl group, phenanthryl group, triphenylene group, carbazolyl group, 9-phenylcarbazolyl group, and the like, but are not limited thereto.

Examples of the unsubstituted aryloxy group applied to the formula (1) include phenyloxy group, naphthyloxy group, anthryloxy group, phenanthryloxy group and the like. At least one hydrogen of the aryloxy group may be substituted with an alkyl group of C1-C5, an alkoxy group of C1-C5, an aryl group of C6-C14, an aryloxy group of C6-C20, a halogen atom, an amino group, a cyano group, or the like. .

Preferred Ar ₂ and Ar ₃ is a ring compound of 1 to 3 rings selected from, for example, a phenyl group, a naphthyl group, a biphenyl group, a fluorenyl group or a carbazolyl group, and 1 to 4 hydrogen atoms of these ring compounds are lower than C1 to C4. And cyclic compounds substituted with alkyl, C1 to C5 lower alkoxy, cyano, amino, phenoxy, phenyl or halogen. More preferably Ar ₂ and Ar ₃ is a group consisting of a phenyl group, tolyl group, fluorophenyl group, biphenyl group, (N, N'-diphenyl) aminophenyl group, naphthyl group, phenylcarbazolyl group, and dimethylfluorenyl group Is selected.

Preferred examples of Ar ₄ include the above 1 to 3 ring ring compounds and phenoxy groups, and these also have 1 to 4 hydrogen atoms of C1 to C4 lower alkyl, C1 to C5 lower alkoxy, cyano, amino, phenoxy, It may be substituted with phenyl or halogen. More preferably Ar ₄ is selected from the group consisting of a phenyl group, tolyl group, cyanophenyl group, fluorophenyl group, biphenyl group, naphthyl group, naphthylphenyl group.

In Formula 1, when Ar ₁ and Ar ₃ or Ar ₂ and Ar ₃ are connected to each other to form a ring, the ring may be a carbazolyl group.

The compounds of Formula 1 according to the present invention have a function as a hole injection material, a hole transport material and / or a light emitting material. In addition, since the heterocyclic compound of Formula 1 has a rigid tricyclic structure at the center of the compound, the glass transition temperature (Tg) and melting point are increased. Therefore, heat resistance to Joule heat generated between the organic layer, or between the organic layer and the metal electrode in the electroluminescence at the time of electroluminescence, and the resistance under high temperature environment is increased. The organic EL device manufactured by using the heterocyclic compound according to the present invention has high durability during storage and driving.

Hereinafter, specific examples of the heterocyclic compound represented by Formula 1 of the present invention, Compounds 1 to 183, preferably compounds 1, 13, 25, 37, 49, 61, 73, 85 and 112 represented by the following structural formula Although the heterocyclic compound of the present invention is not limited to these compounds:

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Hereinafter, the method for preparing a heterocyclic compound according to the present invention will be described in detail with reference to the following Scheme 1, but this is only one example for preparing the heterocyclic compound of the present invention, and the preparation thereof is Of course, it is not limited.

Scheme 1

First, intermediate (b) is prepared by reacting the compounds of 5-dimethyl-1,4-phenylenediamine (a) and (i). In the compound (i), L ₁ may be selected from, for example, chloro, bromo or anhydride as the leaving group. The obtained intermediate (b) is then subjected to a cyclization reaction at high temperature and high pressure in the presence of a base to prepare an intermediate (c). The compound (d) according to one embodiment of the present invention can finally be obtained by reacting compound (ii) in the presence of a suitable catalyst. Meanwhile, in the above formula, Ar ₁ and Ar ₃ or Ar ₂ and Ar ₃ may be connected to each other to form a ring.

An organic light emitting electroluminescent device according to the present invention comprises: a first electrode; A second electrode; And at least an organic layer between the first electrode and the second electrode, wherein the organic layer may include a heterocyclic compound represented by Formula 1 as described above.

The structure of the organic electroluminescent device according to the present invention is very diverse. The organic film containing the heterocyclic compound of Formula 1 may be a hole injection layer, a hole transport layer or a single film having a hole injection and a hole transport function at the same time, preferably a hole injection layer.

The organic electroluminescent device of the present invention includes an anode, a hole injection layer (HIL), a hole transport layer (HTL), a light emitting layer (EML), an electron transport layer (ETL), an electron injection layer (EIL), and a cathode shown in FIG. In addition to the bottom emission organic electroluminescence device having a (Cathode) structure, the structure of the organic electroluminescence device having various structures such as the top light emitting device is possible, and one or two intermediate layers may be further formed as necessary.

Compounds of Formula 1 are excellent as a hole injection characteristics and hole transport characteristics, and are useful as a hole-related layer material, in particular, a hole injection layer material, and can be used as a host material of blue, green, red fluorescent and phosphorescent devices. The organic electroluminescent device using the formula (1) has the characteristics of high efficiency, low voltage, high brightness, long life.

 Hereinafter, a method of manufacturing an organic electroluminescent device according to the present invention will be described with reference to the organic electroluminescent device shown in FIG. 1.

First, a first electrode material having a high work function on the substrate is formed by vapor deposition or sputtering to form a first electrode. The first electrode may be an anode. Herein, a substrate used in a conventional organic electroluminescent device is used, and an organic substrate or a transparent plastic substrate having excellent mechanical strength, thermal stability, transparency, surface smoothness, ease of handling, and waterproofness is preferable. As the material for the first electrode, indium tin oxide (ITO), indium zinc oxide (IZO), tin oxide (SnO 2), zinc oxide (ZnO), and the like, which are transparent and have excellent conductivity, are used.

Next, a hole injection layer HIL may be formed on the first electrode by using various methods such as vacuum deposition, spin coating, casting, and LB.

As the hole injection layer material, a heterocyclic compound represented by Chemical Formula 1 may be used, and a known material used as another hole injection layer material may be selected. As a known substance, for example, 1,3,5-tricarbazolylbenzene, 4,4'-biscarbazolylbiphenyl, polyvinylcarbazole, m-biscarbazolylphenyl, 4,4'-biscarba Zolyl-2,2'-dimethylbiphenyl, 4,4 ', 4 "-tri (N-carbazolyl) triphenylamine, 1,3,5-tri (2-carbazolylphenyl) benzene, 1,3, 5-tris (2-carbazolyl-5-methoxyphenyl) benzene, bis (4-carbazolylphenyl) silane, N, N'-bis (3-methylphenyl) -N, N'-diphenyl- [1, 1-biphenyl] -4,4'diamine (TPD), N, N'-di (naphthalen-1-yl) -N, N'-diphenyl benzidine (α-NPD), N, N'-diphenyl -N, N'-bis (1-naphthyl)-(1,1'-biphenyl) -4,4'-diamine (NPB), poly (9,9-dioctylfluorene-co-N- ( 4-butylphenyl) diphenylamine) (poly (9,9-dioctylfluorene-co-N- (4-butylphenyl) diphenylamine) (TFB) or poly (9,9-dioctylfluorene-co-bis-N, N-phenyl-1,4-phenylenediamine (poly (9,9-dioctylfluorene-co-bis- (4-butylphenyl-bis-N, N-phenyl-1,4-phenylenediamin) (PFB), etc.) It may be, but is not limited thereto.

The hole injection layer may be formed using various known methods such as vacuum deposition, spin coating, casting, LB, and the like.

When the hole injection layer is formed by vacuum deposition, the deposition conditions vary depending on the compound used as the material of the hole injection layer, the structure and thermal properties of the hole injection layer as desired, and the deposition temperature is generally 50 to 500 ° C., It is preferable that a vacuum degree of 10 ^-8 to 10 ^-3 torr, a deposition rate of 0.01 to 100 Pa / sec, and a film thickness are appropriately selected in the range of usually 10 Pa to 5 mu m.

In the case of forming the hole injection layer by spin coating, the coating conditions vary depending on the compound used as the material of the hole injection layer, the structure and the thermal properties of the desired hole injection layer, but the coating speed is about 2000 rpm to 5000 rpm. , The heat treatment temperature for removing the solvent after coating is preferably selected in the temperature range of about 80 ℃ to 200 ℃.

The hole transport layer may also be formed using a variety of known methods such as vacuum deposition, spin coating, casting, and LB. In the case of forming the hole transport layer by vacuum deposition and spin, the deposition and coating conditions may be Although it depends on the compound to be used, it is generally selected from the range of conditions substantially the same as formation of a hole injection layer.

As the hole transport layer material, a heterocyclic compound represented by Formula 1 may be used, and a known material used as the hole transport layer material may be selected. As a known substance, for example, known carbazole derivatives such as N-phenylcarbazole and polyvinylcarbazole, N, N'-bis (3-methylphenyl) -N, N'-diphenyl- [1, Having an aromatic condensed ring such as 1-biphenyl] -4,4'-diamine (TPD), N, N'-di (naphthalen-1-yl) -N, N'-diphenyl benzidine (α-NPD) Conventional amine derivatives and the like are used.

The light emitting layer for each color may be formed on the hole injection layer and the hole transport layer. The light emitting layer material is not particularly limited and a material arbitrarily selected from known materials, known host materials, and dopant materials may be used as the light emitting layer material. In particular, in the case of the host material of the blue, green, red fluorescent and phosphorescent devices, the heterocyclic compound of Formula 1 according to the present invention may be used, and other known materials may also be used.

The red light emitting layer includes, for example, DCM1, DCM2, Eu (thenoyltrifluoroacetone) 3 (Eu (TTA) 3, butyl-6- (1,1,7,7-tetramethyl zulolidyl-9-enyl) -4H-pyran ) {butyl-6- (1,1,7,7, -tetramethyljulolidyl-9-enyl) -4H-pyran: DCJTB} And the like can be used. Alternatively, Alq3 may be formed by doping a dopant such as DCJTB, or by co-depositing Alq3 and rubrene and doping the dopant. 4,4'-N, N'-dicarbazole-biphenyl (4,4'-N Various modifications are possible, such as doping of -N'- dicarbazole-biphenyl) (CBP) with a dopant such as BTPIr or RD 61.

For example, coumarin 6, C545T, quinacridone, Ir (ppy) _3, etc. may be used as the green light emitting layer. On the other hand, various modifications are possible, such as using Ir (ppy) 3 as a dopant for CBP or coumarin-based material as a dopant for Alq 3 as a host. Specific examples of the coumarin dopant include C314S, C343S, C7, C7S, C6, C6S, C314T, and C545T.

In the blue light emitting layer, for example, oxadiazole dimer dyes (Bis-DAPOXP), spiro compounds (Spiro-DPVBi, Spiro-6P), triarylamine compounds, bis Bis (styryl) amine (DPVBi, DSA), Compound (A) Flrpic, CzTT, Anthracene, TPB, PPCP, DST, TPA, OXD-4, BBOT, AZM-Zn, naphthalene moiety Various aromatic hydrocarbon compounds, such as BH-013X (Idemitsu Co., Ltd.), may be used. On the other hand, various modifications are possible, such as IDE105 (trade name, product of Idemitsu Co., Ltd.) can be used as a dopant for IDE140 (trade name, product of Idemitsu Co., Ltd.).

The thickness of the light emitting layer is 200 kPa to 500 kPa, preferably 300 kPa to 400 kPa. Meanwhile, the thicknesses of the light emitting layers in the R, G, and B regions may be the same or different from each other. If the thickness of the light emitting layer is less than 200 kW, the lifetime is reduced, and if the thickness of the light emitting layer is more than 500 kW, the driving voltage rise is high, which is not preferable.

The light emitting layer can be formed using a variety of known methods such as vacuum deposition, spin coating, casting, LB, etc., and when the light emitting layer is formed by vacuum deposition and spinning, the deposition conditions and coating conditions are used. Although it depends on the compound to be used, it is generally selected from the conditions range substantially the same as formation of a hole injection layer.

A hole blocking layer (not shown) may be selectively formed by vacuum deposition or spin coating a material for hole blocking on the light emitting layer. At this time, the material for the hole blocking layer is not particularly limited, but should have an ion transport potential and have a higher ionization potential than the light emitting compound, and is typically bis (2-methyl-8-quinolato)-(p-phenylphenolato) -aluminum (Balq). ), bathocuproine (BCP), tris (N-aryl benzimidazole) (TPBI), and the like.

The thickness of the hole blocking layer is 30 kPa to 60 kPa, preferably 40 kPa to 50 kPa. If the thickness of the hole blocking layer is less than 30 kW, hole blocking characteristics may not be well implemented, and if the hole blocking layer is more than 50 kW, the driving voltage may increase.

The hole blocking layer may be formed using a variety of known methods such as vacuum deposition, spin coating, casting, LB, etc., and when the hole blocking layer is formed by vacuum deposition or spin, the deposition conditions and The coating conditions vary depending on the compound used, but are generally selected from the range of conditions almost identical to the formation of the hole injection layer.

An electron transport layer is selectively formed by vacuum deposition or spin coating an electron transport material on the light emitting layer or the hole blocking layer. The electron transport material is not particularly limited and may be Alq3 or the like.

The electron transport layer may have a thickness of 100 kPa to 400 kPa, preferably 250 kPa to 350 kPa. This is because when the thickness of the electron transport layer 240 is less than 100 kV, the charge transport may be broken due to excessive electron transport speed. When the electron transport layer 240 exceeds 400 kV, the driving voltage may increase.

The electron transport layer can be formed using a variety of known methods such as vacuum deposition, spin coating, casting, LB, etc., and when the electron transport layer is formed by vacuum deposition and spin, the deposition conditions and coating conditions Although depending on the compound used, it is generally selected from the range of conditions substantially the same as formation of a hole injection layer.

The electron injection layer 250 may be formed on the emission layer, the hole blocking layer, or the electron transport layer by using a vacuum deposition method or a spin coating method. Materials for forming the electron injection layer 250 may include materials such as BaF 2, LiF, NaCl, CsF, Li 2 O, BaO, Liq, but are not limited thereto.

The electron injection layer may have a thickness of 2 kPa to 10 kPa, preferably 2 kPa to 5 kPa. Among these, 2 GPa-4 GPa are especially suitable thickness. This is because when the thickness of the electron injection layer is less than 2 kV, the electron injection layer may not serve as an effective electron injection layer, and when the thickness of the electron injection layer exceeds 10 kW, the driving voltage may increase.

The electron injection layer may be formed using a variety of known methods such as vacuum deposition, spin coating, casting, LB, etc., and when the electron injection layer is formed by vacuum deposition and spin, the deposition conditions And coating conditions vary depending on the compound used, but is generally selected from the range of conditions almost the same as the formation of the hole injection layer.

Subsequently, an organic electroluminescent device is completed by depositing a second electrode material on the electron injection layer to form a second electrode.

As the material for the second electrode, indium tin oxide (ITO), indium zinc oxide (IZO), tin oxide (SnO ₂ ), zinc oxide (ZnO), and the like, which are transparent metal oxides having excellent conductivity, may be used. Alternatively, lithium (Li), magnesium (Mg), aluminum (Al), aluminum-lithium (Al-Li), calcium (Ca), magnesium-indium (Mg-In), magnesium-silver (Mg-Ag), calcium By forming (Ca) -aluminum (Al) as a thin film, it can be variously formed as a reflective electrode, a translucent electrode, or a transparent electrode. Of course, the material forming the second electrode is not limited to the above-described metal and metal combination.

The first electrode and the second electrode may serve as an anode and a cathode, respectively, and vice versa.

In the following, the synthesis examples of the heterocyclic compound represented by the formula (1) according to the present invention and the production examples of the organic electroluminescent device are specifically illustrated by way of examples, but the present invention is not limited to the following examples.

<Examples>

Synthetic example  1: Preparation of Compound 1

Compound 1 was synthesized via the reaction route of Scheme 2:

Scheme 2

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.

(1) Synthesis of Intermediate A

10 g (73.4 mmol) of 2,5-dimethyl-1,4-phenylenediamine was dissolved in 50 ml of dichloromethane, and 25 ml of triethylamine was added thereto. The resulting reaction solution was cooled under an ice bath, and 17 ml (0.147 mol) of benzoyl chloride was added dropwise thereto, followed by stirring at 30 ° C for 1 hour. Solvent was removed from the resulting reaction solution and recrystallized from DMF. The obtained crystals were filtered off while washing with acetone to obtain 23.4 g of intermediate A as a white solid (yield 93%).

¹ H NMR (CDCl ₃ , 400 MHz) δ (ppm) 8.15 (s, 2H), 7.95-7.41 (m, 10H), 7.29 (s, 2H) 2.28 (s, 6H); ¹³ C NMR (CDCl ₃ , 100 MHz) δ (ppm) 165.2, 134.4, 133.5, 131.9, 128.6, 127.5, 126.3, 121.2, 13.8.

(2) Synthesis of Intermediate B

A mixture of 4.5 g (12 mmol) of intermediate A and 13.5 g (120 mmol) of potassium t-butoxide was sufficiently mixed and stirred in an autoclave and reacted at 340-350 ^° C. and 5 MPa for 2 hours. After the reaction was completed, the reaction mixture was cooled to room temperature, the resulting tar phase was pulverized, neutralized, filtered and dried while washing with distilled water. The obtained crude product was purified for 2 days using acetone in a soxhlet apparatus to obtain 0.94 g of intermediate B as a white solid (yield 21%).

¹ H NMR (DMSO-d 6, 400 MHz) δ (ppm) 11.0, (s, 2H), 7.86 (d, 4H), 7.44 (t, 6H), 7.27 (t, 2H), 6.89 (s, 2H); ¹³ C NMR (DMSO-d 6, 100 MHz) δ (ppm) 137.9, 134.6, 132.6, 128.7, 127.0, 126.9, 124.7, 99.3, 97.8.

(3) Synthesis of Compound 1

3.08 g (10 mmol) of intermediate B and 9.73 g (30 mmol) of 4-bromotriphenylamine were added to 50 ml of DMPU (1,3-Dimethyl-3,4,5,6-tetrahydro- (1H) -pyrimidinone) To this, 0.761 g (4 mmol) of CuI, 11.057 g (80 mmol) of potassium carbonate (K ₂ CO ₃ ), and 0.1 g (4 mmol) of 18-crown-6 were added. Then, the mixture was stirred at 170 ° C. for 20 hours and then cooled to room temperature. The solvent was distilled off under reduced pressure in the resulting mixed solution, and the resulting residue was dissolved by adding 100 ml of dichloromethane and washed several times with water. The resulting organic layer was dried over MgSO ₄ and dried under reduced pressure to obtain a crude product, which was purified by silica gel column chromatography to obtain 3.74 g of compound 1 as a solid (yield 47%).

¹ H NMR (CD ₂ Cl ₂ , 400 MHz) δ (ppm) 7.91 (d, 4H), 7.45 (s, 2H), 7.38-7.08 (m, 38H); ¹³ C NMR (CD ₂ Cl ₂ , 100 MHz) δ (ppm) 129.7, 129.3, 129.0, 128.6, 127.2, 126.4, 125.2, 124.5, 124.1, 123.5, 123.1, 122.2, 103.2, 100.4, 99.3, 98.3.

Synthetic example  2. Preparation of Compound 73

Compound 73 was synthesized via the reaction route of Scheme 3:

Scheme 3

.

.

(1) Synthesis of Intermediate C

16.7 g (100 mmol) carbazole, 26.5 g (130 mmol) iodobenzene, 1.9 g (10 mmol) CuI, 138 g (1 mol) potassium carbonate (K ₂ CO ₃ ), and 18-crown-6 (18-crown-6) 530 mg (2 mmol) was dissolved in 500 mL of DMPU (1,3-Dimethyl-3,4,5,6-tetrahydro- (1H) -pyrimidinone) and heated at 170 ^° C. for 8 hours. After the reaction was completed, the reaction mixture was cooled to room temperature, the solid material was filtered, a small amount of aqueous ammonia was added to the filtrate, and washed three times with 300 ml of diethyl ether. The resulting organic layer was dried over magnesium sulfate and dried under reduced pressure to obtain a crude product, which was purified by silica gel column chromatography to obtain 22 g of intermediate C as a white solid (yield 90%).

¹ H NMR (CDCl ₃ , 400 MHz) δ (ppm) 8.12 (d, 2H), 7.58-7.53 (m, 4H), 7.46-7.42 (m, 1H), 7.38 (d, 4H), 7.30-7.26 (m , 2H); ¹³ C NMR (CDCl ₃ , 100 MHz) δ (ppm) 141.0, 137.9, 130.0, 127.5, 127.3, 126.0, 123.5, 120.4, 120.0, 109.9.

(2) Synthesis of Intermediate D

After adding 2.433 g (10 mmol) of intermediate C in 100 mL of 80% acetic acid, 1.357 g (5.35 mmol) of iodine (I ₂ ) and 0.333 g (1.46 mmol) of ortho-periodic acid (H ₅ IO ₆ ) were added to the solid state. After the addition, the mixture was stirred at 80 ° C. for 2 hours in a nitrogen atmosphere.

After the reaction was completed, the mixture was extracted three times with 50 ml of diethyl ether. The organic layer was collected, dried over magnesium sulfate, and the crude product obtained by evaporating the solvent was separated and purified by silica gel column chromatography to obtain 3.23 g of intermediate D as a white solid (yield 87%).

¹ H NMR (CDCl ₃ , 300 MHz) δ (ppm) 8.43 (d, 1H), 8.05 (d, 1H), 7.62 (dd, 1H), 7.61-7.75 (m, 2H), 7.51-7.43 (m, 3H ), 7.41-7.35 (m, 2H), 7.27 (dd, 1H), 7.14 (d, 1H)

(3) Synthesis of Compound 73

After inserting the intermediate B 3.08g (10mmol) and Intermediate D 11.1g (30mmol) in DMPU 50㎖, here CuI 0.761g (4mmol), potassium carbonate _{(K 2 CO 3) 11.057g (} 80mmol), 18- crown- 6 0.1 g (4 mmol) was added. Then, the mixture was stirred at 170 ° C. for 20 hours, cooled to room temperature, and the solvent was distilled off under reduced pressure. The resulting residue was taken up with 100 mL of dichloromethane and washed several times with water. The resulting organic layer was dried over magnesium sulfate, and then dried under reduced pressure to obtain a crude product, which was purified by silica gel column chromatography to obtain 3.32 g of compound 73 as a pale yellow solid (yield 42%).

¹ H NMR (CD ₂ Cl ₂ , 400 MHz) δ (ppm) 8.22 (d, 2H), 7.70 (d, 4H), 7.68-6.81 (m, 32H); ¹³ C NMR (CD ₂ Cl ₂ , 100 MHz) δ (ppm) 130.4, 129.6, 128.9, 128.7, 128.5, 128.3, 128.0, 127.2, 127.0, 126.8, 126.2, 125.1, 124.6, 124.2, 123.8, 121.8, 121.2, 120.5 , 120.1, 110.4, 110.1, 103.2, 99.5, 98.5, 98.2

Example  1. Organic Field  Fabrication of light emitting device

Corning 15 Ω / cm ² as anode (1200Å) ITO glass substrate is cut into 50mm × 50mm × 0.7mm size and ultrasonically cleaned with isopropyl alcohol and pure water for 5 minutes, and then irradiated with ultraviolet light for 30 minutes, exposed to ozone, and vacuum-deposited. This glass substrate was installed.

Compound 1 was first vacuum-deposited as a hole injection layer on the substrate to form a thickness of 600 Å. Subsequently, 4,4'-bis [N- (1-naphthyl) -N-phenylamino] biphenyl (hereinafter referred to as NPB) was vacuum deposited to a thickness of 300 kPa as a hole transport compound to form a hole transport layer.

A light emitting layer was formed on the hole transport layer by simultaneously depositing a known blue fluorescent host IDE215 (Idemitsu Co.) and a known blue fluorescent dopant IDE118 (Idemitsu Co.) at a weight ratio of 98: 2.

Subsequently, Alq ₃ was deposited on the emission layer with an electron transport layer at a thickness of 300 GPa, LiF was deposited on the electron transport layer with an electron injection layer, which is a halogenated alkali metal, at a thickness of 10 GPa, and Al was deposited at a thickness of 3000 GPa (cathode electrode). The organic electroluminescent device was manufactured by forming a LiF / Al electrode by vacuum evaporation.

The obtained device had a high luminance of a driving voltage of 6.95 V and a light emission luminance of 7,781 cd / m 2 at a current density of 100 mA / cm 2, a color coordinate of (0.144, 0.241) and a light emission efficiency of 7.78 cd / A.

Example  2. Organic Field  Fabrication of light emitting device

An organic electroluminescent device was manufactured in the same manner as in Example 1, except that Compound 73 was used instead of Compound 1 to form the hole injection layer.

The resulting device showed a current density of 100mA / ㎠ 7.82V driving voltage, light emission brightness 6,932cd / ㎡ of high brightness in, color coordinates of (0.143, 0.242), and the light emitting efficiency was 6.93cd / A.

Comparative example  1. Organic Field  Fabrication of light emitting device

In the same manner as in Example 1, except that 4,4'4 ”-tris [2-naphthyl (phenyl) amino] triphenylamine (hereinafter 2-TNATA) was used instead of Compound 1 to form the hole injection layer. To produce an organic electroluminescent device.

The obtained device exhibited a driving voltage of 7.757 V and an emission luminance of 6,219 cd / m 2 at a current density of 100 mA / cm 2, the color coordinates of which were almost the same (0.145, 0.243), and the emission efficiency was 6.22 cd / A.

Table 1 shows the results of Examples 1 and 2 and Comparative Example 1.

Drive voltage (V) Current density
(mA / ㎠) Luminance luminance (cd / m2) Luminous efficiency
(cd / A) Color coordinates (x, y) Example 1 6.95 100 7,781 7.78 0.144, 0.243 Example 2 7.28 100 6,932 6.93 0.143, 0.242 Comparative Example 1 7.75 100 6,219 6.22 0.143, 0.243

As a result of comparing the compounds having the structure of Formula 1 according to the present invention with 2-TNATA, which is a known substance, all showed superior I-V-L properties equivalent to those of 2-TNATA. Referring to Table 1, it can be seen that Example 1 and Example 2 exhibit the characteristics of high efficiency, low voltage, high brightness with improved efficiency. On the other hand, the compound of Example 1 and Example 2 showed better life characteristics than the compound of Comparative Example 1.

As a result of using the compound having the structure of Formula 1 according to the present invention as the hole injection layer forming material in the organic EL device, a low voltage, high efficiency, high brightness, long life organic EL device based on excellent hole injection and hole transport ability I could make it. As described above, the heterocyclic compound of the present invention has excellent electrical properties and charge transporting ability, and thus is suitable for hole injection materials, hole transport materials and / or light emitting materials suitable for fluorescent and phosphorescent devices of all colors such as red, green, blue, and white. It is useful as, it can be used to manufacture high efficiency, low voltage, high brightness, long life organic electroluminescent device.

The above embodiments are merely exemplary, and various modifications and equivalent other embodiments are possible to those skilled in the art. Accordingly, the true scope of protection of the present invention should be determined by the technical idea of the invention described in the following claims.

Claims (9)

Heterocyclic compounds represented by the formula (1):
[Formula 1]

Where
Ar ₁ is a phenylene group or a biphenylene group;
Ar ₂ and Ar ₃ are each independently selected from the group consisting of phenyl group, tolyl group, biphenyl group and naphthyl group;
Ar ₄ is a pyridinyl group or a fluorenyl group; And
Ar ₁ and Ar ₃ , or Ar ₂ and Ar ₃ may be connected to each other to form a ring. Heterocyclic compounds represented by the formula (1):
[Formula 1]

Where
Ar ₁ is a phenylene group or a biphenylene group;
Ar ₂ and Ar ₃ are each independently a pyridinyl group or a fluorenyl group;
Ar ₄ is selected from the group consisting of a phenyl group, tolyl group, biphenyl group, naphthyl group, naphthylphenyl group, pyridinyl group and fluorenyl group; And
Ar ₁ and Ar ₃ , or Ar ₂ and Ar ₃ may be connected to each other to form a ring. Heterocyclic compounds represented by the formula (1):
[Formula 1]

Where
Ar ₁ is selected from the group consisting of naphthylene group, pyridinylene group and fluorenylene group;
Ar ₂ and Ar ₃ are each independently selected from the group consisting of phenyl group, tolyl group, biphenyl group, naphthyl group, pyridinyl group and fluorenyl group;
Ar ₄ is selected from the group consisting of a phenyl group, tolyl group, biphenyl group, naphthyl group, naphthylphenyl group, pyridinyl group and fluorenyl group; And
Ar ₁ and Ar ₃ , or Ar ₂ and Ar ₃ may be connected to each other to form a ring. The heterocyclic compound according to claim 1, wherein Ar ₁ and Ar ₃ , or Ar ₂ and Ar ₃ are connected to each other to form a carbazolyl group. A first electrode; A second electrode; And an organic film disposed between the first electrode and the second electrode, wherein the organic film comprises the heterocyclic compound according to any one of claims 1 to 4. Electroluminescent device. The organic electroluminescent device according to claim 5, wherein the organic film is a hole injection layer or a hole transport layer. The organic electroluminescent device according to claim 5, wherein the organic film is a single film having both hole injection and hole transport functions. The organic electroluminescent device according to claim 5, wherein the organic film is a light emitting layer. The organic electroluminescent device according to claim 5, wherein the organic film is a light emitting layer and the heterocyclic compound is used as a fluorescent or phosphorescent host.

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