KR20090072152A - Pyrene derivatives and organic electroluminescent devices employing the same - Google Patents

Abstract

A pyrene derivative is provided to ensure excellent hole and electron transport characteristic at the same time and to implement full color display with high brightness and wide color reproduction range. A pyrene derivative has a structure represented by chemical formula 1. In chemical formula 1, A is an amine-based ring compound having a double bond(>C=N-) of nitrogen atom(N) and CN; a carbon atom of pyrene which is a main group and the amine-based ring compound are connected by a covalent bond; and k is the number of A substituted with the pyrene and is selected from 1, 2, 3 and 4, wherein k is 2 or more, each A is the same or different.

Description

Pyrene derivatives and organic electroluminescent devices using the same {Pyrene Derivatives and Organic Electroluminescent Devices Employing the Same}

The present invention relates to a pyrene derivative and an organic light emitting device using the same, and more particularly, a compound which can be used for a high brightness electroluminescent device having excellent hole and electron transporting properties simultaneously, and a full color and a large display using the same. It relates to a possible organic electroluminescent device.

An organic light emitting diode (OLED) is a display that can emit characters or images of various colors by emitting light by organic materials by applying a voltage to an organic (polymer or low molecular) thin film. 1/3), fast response speed (1000 times of LCD), low power consumption (1/2 of LCD), high sharpness and flexibility, and are attracting attention as small mobile displays such as mobile phones and PDAs. In the future, it is expected to develop into notebook PCs, wall-mounted TVs, and displays of simpler and clearer scroll TVs like paper after 2010.

Organic electroluminescent devices using low molecular weight compounds in the organic layer generally include an anode / hole injection layer (HIL) / hole transporting layer (HTL) / emissive layer / electron transport layer (ETL); Electron Transporting Layer (EIL) / Electron Injection Layer (EIL) / cathode (cathode).

In order to operate the organic light emitting diode at low voltage, the overall thickness of the organic thin film layer is maintained at about 100 to 200 nm, and it is very important to control the process so that the surface of each layer is formed with a uniform thin film. As a large amount of charges (holes and electrons) are injected, when the amount of injected electrons and holes is balanced, exciton formation efficiency in the light emitting layer is increased, thereby improving luminous efficiency. In other words, HIL and EIL increase the amount of holes and electrons injected from the anode and cathode, respectively, and HTL and ETL receive holes and electrons from HIL and EIL and transfer them to the light emitting layer quickly. It will serve to trap the former. That is, a large amount of holes and electrons are collected in the light emitting layer by HIL, HTL, ETL, and EIL, leading to formation of a large amount of excitons in the light emitting layer. As a result, the luminous efficiency is increased.

As another method of increasing luminous efficiency, a dramatic increase in luminous efficiency may be induced by mixing the EML layer with two materials, that is, a host and a dopant. In other words, when 90 to 99% of the host and 1 to 10% of the dopant are deposited, energy transfer to the dopant is concentrated, and thus the emission efficiency is increased by rapidly increasing the exciton formation rate in the dopant.

Currently, organic light emitting diodes are being applied to small-scale applications, and like other displays, R & D is focused on realizing large-area organic light emitting diodes as part of the expansion of their application fields and the formation of large-scale organic light emitting diodes. . The most important field of application of large-area organic light emitting diode is TV field.

As described above, the materials for HIL, HTL, EML (host & dopant), HBL (hole blocking layer), ETL, and EIL, which are involved in the light emission of the organic light emitting device, are a big problem for the performance of mobile phones. However, brightness, power consumption, color gamut and lifetime for TV applications need improvement. As such, it is essential to improve the performance of each material in order to enter the TV market by implementing large-area organic light emitting diodes. Various materials have been developed and announced by various institutes, but materials suitable for application to the TV market cannot be developed. have.

Phosphorescent materials are theoretically four times more efficient than fluorescent materials among the light emitting materials of organic electroluminescent devices. Recently, green and red phosphorescent materials have reached the level of commercialization. In the case of using the phosphor in the organic light emitting device, the formation of a hole blocking layer (HBL) is required between the EML and the ETL, and since the light is emitted in the triplet state, the fluorescent organic light emitting device is applied to the organic light emitting device. There is a problem that the conventional host material applied is not applicable to phosphorescent devices. In other words, the development of a novel material capable of energy transfer to a phosphorescent dopant in a triplet state is required.

In the technical field related to the conventional organic EL device and the phosphor material mentioned above, EP 1 571 193 A1, EP 1 551 206, Korean Patent Publication No. 2005-0099270, Korean Patent Publication No. 2003-0041968, Korea Patent Registration No. 0392972, Korea Patent Registration No. 0387166, JP JP-A-7-252474 and the like. The introduction and problems of the conventional organic light emitting device material is as follows.

In the organic electroluminescent device, the electron transport layer contains an electron transport compound, and a metal having a electron pulling body capable of stabilizing anion radicals generated when electrons are injected from the cathode, or a metal capable of well receiving electrons. Compounds are mainly used. Compounds having an electron-gripping body include compounds containing functional groups (-C = N-) that resonate electrons by resonance, such as cyan groups, oxadiazoles, and triazoles. Representative examples include Alq3, PBD (2-biphenyl-4-yl-5- (4-t-butylphenyl) -1,3,4-oxadiazole) and Spiro-PBD, which serve as electron transport and hole binding. Alq3 is the most commonly used. Alq3 has been used since the late 1980s when the organic light emitting device was recognized for commercial value, and is still used. Alq3, however, is vulnerable to moisture and oxygen and is problematic in terms of longevity of at least 20,000 hours for TV applications and needs improvement.

The hole injection layer and the hole transport layer contain a hole transport compound, which facilitates hole injection from the anode, and ultimately improves the power efficiency of the device and increases the life of the device. In order to lower the hole injection barrier, the ionization energy should be similar to the work function of the anode ITO, and the interface adhesion with the ITO should be high. The hole transport layer should not only easily transport the injected holes to the light emitting layer, but also increase the probability of forming exciton by binding electrons to the light emitting area, and should be a material having high hole mobility. However, the materials used in the conventional organic electroluminescent devices do not exhibit sufficient performance required for practical application, especially TV applications. One of the main reasons for this is the low heat resistance of the hole injection / transport material. Joule heat generated during the operation of the organic light emitting device causes crystallization of the hole transport material to form a dark spot. Therefore, the hole injection material or the hole transport material is preferably in an amorphous state while excellent in heat resistance. Conventionally used hole injection / transport material is mainly used aromatic amine that can stabilize the radicals generated during hole injection (biphenyl diamine derivatives, starburst type compound, spiro ( Biphenyl diamine derivatives and ladder type compounds having spiro groups are known, but only a few are known to be suitable for practical use. NPD (N, N'-bis (1-naphthyl) -N, N'-diphenyl-1,1'-biphenyl-4,4'-diamine) is the most widely used hole transport layer material. It shows the transition temperature (Tg) and is currently used in 2 "grade organic light emitting device products. Therefore, if this material is used in organic light emitting devices that are applied in TV field, crystallization occurs due to heat generation, and eventually TV brightness is achieved. Deterioration and lifespan will be caused.

In terms of light emitting materials, many green and red materials have been developed with some characteristics, but have not yet reached the level of TV application. In particular, blue materials with a large band gap are recognized as more difficult technologies than other materials. As an example, there are very few published examples of low molecular weight phosphorescent blue materials, and high molecular weight blue materials are also pointed out as a problem that their lifespan is too short to be applied to commercial products. In addition, commercially available low-molecular blue fluorescent materials rarely come close to NTSC color coordinates (blue; 0.14, 0.08). Some material companies and research institutes have announced high-purity blue materials, but they have long life and luminance. It is known that the low commercial potential is low.

As mentioned above, in the case of phosphorescent devices, the development of a new host material is required, and in the past, the application of fluorene-based materials has been considered, but since the triplet energy level interacts with the energy level of the dopant, There is an unsuitable problem.

In connection with the above, the present inventors have reviewed the materials of the prior art and the materials currently being used industrially based on various researches and experiments, and they are suitable for small organic light emitting devices, but they are organic light emitting devices for medium and large sized TV applications. It has been found that there is a significant lack of characteristics in terms of efficiency, color coordinates and lifetime.

The problem to be solved by the present invention to solve the problems of the prior art as described above is to provide a novel compound having a high efficiency, high color purity and an organic electroluminescent device comprising the same.

According to an aspect of the present invention to achieve the above object,

It provides a compound represented by the following formula (1).

<Formula 1>

Here, A is an amine cyclic compound having a nitrogen atom (N) and a CN double bond (> C = N-) at the same time, the carbon atom of pyrene as the central group and the nitrogen atom of the amine cyclic compound are covalently bonded. And k is selected from 1, 2, 3, and 4 as the number of As substituted in the pyrene, and when k is 2 or more, each A may be the same as or different from each other.

In addition, according to another aspect of the present invention to achieve the above object,

In an organic light emitting device having a first electrode, an organic material layer consisting of one or more layers including a light emitting layer and a second electrode sequentially stacked, at least one of the organic material layer comprises a compound of the formula (1) An electroluminescent device is provided.

Since the pyrene derivative, which is a compound according to the present invention, contains both a hole transporting amine group and an electron transporting CN double bond at the same time, it has excellent hole and electron transporting properties and can be applied as a material for high brightness electroluminescent devices. In addition, it can be provided with a variety of characteristics according to the type of the substituent, it is possible to apply to the hole injection material, hole transport material, electron injection material, electron transport material, hole blocking material and light emitting material. In other words, it is possible to provide a new electroluminescent device material having high efficiency and high color purity and an organic electroluminescent device including the same, thereby realizing a full color display having excellent luminance and color gamut and contributing to the realization of an organic electroluminescent device TV. Therefore, the early commercialization of organic light emitting diode TV is expected.

The pyrene derivative compound according to one aspect of the present invention is represented by the following Chemical Formula 1.

<Formula 1>

Here, A is an amine cyclic compound having a nitrogen atom (N) and a CN double bond (> C = N-) at the same time, the carbon atom of pyrene as the central group and the nitrogen atom of the amine cyclic compound are covalently bonded. And k is selected from 1, 2, 3, and 4 as the number of As substituted in the pyrene, and when k is 2 or more, each A may be the same as or different from each other.

In order to explain the formula (1) according to the present invention in more detail, the substituents of the compound bound to pyrene, that is, the amine-based cyclic compound including a nitrogen atom and a CN double bond are represented in the formula (2). In addition to S-1 to S-11, examples may be numerous.

 <Formula 2>

Wherein Y ₁ to Y ₁₈ are each independently a hydrogen group, a halogen group, an alkyl group, an alkoxy group, a cyano group, a nitro group, an acyl group, a substituted or unsubstituted amino group, a substituted or unsubstituted aryl group, and a substitution. Or an unsubstituted heterocyclic group.

The compound of Formula 1 according to the present invention is based on pyrene, and is a new structure which is not known until now, in which amine-based cyclic compounds such as Formula 2 having CN double bonds are substituted. In addition, a key feature is that the substituent contains both the CN double bond of the electron pulling characteristic and the amine group of the electron periodic characteristic. One such substituent may be introduced, and up to two, three, and four may be introduced.

For example, in the case of k = 1, the position of the substituent (A ₁ ) may be all positions 1 to 9 of pyrene, and the example thereof is the same as that of Chemical Formula 3.

<Formula 3>

Here, A ₁ may be the same or different and is an amine ring compound having a nitrogen atom (N) and a CN double bond (> C = N-) at the same time, and the carbon atom of the central group pyrene and the nitrogen atom of the amine ring compound It is connected by covalent bond.

In addition, when k = 2, the positions of the two substituents (A ₂ , A ₃ ) may be selected from carbons 1, 2, 3, 6, 7, and 8 of pyrene according to the synthesis method. In other words, when two amine-based cyclic compounds including nitrogen atoms and CN double bonds are introduced, the number of possible structures is seven (1,3 / 1,6 / 1,8 / 3,6 / 3,8 / 6,8). / 2,7), and a few examples are shown below.

<Formula 4>

Here, A ₂ and A ₃ may be the same or different irrespective of each other, and are an amine cyclic compound having a nitrogen atom (N) and a CN double bond (> C = N-) at the same time. The nitrogen atom of the amine cyclic compound is covalently linked.

In addition, when k = 3, the present invention provides a pyrene derivative having a form in which three substituents (Formula 2) having a nitrogen atom and a CN double bond are simultaneously introduced.

Although three substituents (A ₄ , A ₅ , A ₆ ) may be substituted at various positions, the most common ones may be introduced at positions 1, 3, and 6 of pyrene, as shown in Formula 5 below.

<Formula 5>

Here, A ₄ to A ₆ may be the same or different irrespective of each other, and are an amine cyclic compound having both nitrogen atom (N) and CN double bond (> C = N-) which are directly bonded to pyrene, The carbon atom of the central group pyrene and the nitrogen atom of the amine ring compound are covalently linked.

In addition, when k = 4, the present invention provides a pyrene derivative in the form of four substituents (Formula 2) having a nitrogen atom and a CN double bond at the same time.

Four substituents (A ₇ , A ₈ , A ₉ , A ₁₀ ) may be substituted at various positions, but the most common ones may be introduced at positions 1, 3, 6 and 8 of pyrene, as shown in Chemical Formula 6 below. .

<Formula 6>

Here, A ₇ to A ₁₀ may be the same or different irrespective of each other, and are an amine ring compound having a nitrogen atom (N) and a CN double bond (> C = N-) at the same time, and a carbon atom of pyrene as a central group. The nitrogen atom of the amine cyclic compound is covalently linked.

The compound represented by Chemical Formula 1 according to the present invention may be prepared by the reaction of dihalopyrene with an amine cyclic compound having the nitrogen atom and CN double bond shown in Chemical Formula 2 simultaneously. At this time, dibromopyrene, diiodopyrene, dichloropyrene, etc. are mentioned as dihalopyrene. The amine cyclic compound reacting with dihaloprene may be a compound having a hydrogen atom bonded to a nitrogen atom in the structure shown in Chemical Formula 2.

The dihalo-pyrene can be prepared by pyrolysis, bromination, or the like from pyrene, and can be prepared by dropping bromine after dissolving pyrene in carbon tetrachloride. However, the resulting material is made up of three substances: 1,6-dibromopyrene, 1,8-dibromopyrene, and 1,6,8-tribromopyrene. In order to separate the material, 1,6-dibromopyrene is separated through recrystallization under toluene, and then sublimation purification is performed under high vacuum of 10 ^-5 torr to obtain a desired material.

On the contrary, in the case of 2,7-dibromopyrene, pyrene was first formed into a 4,5,9,10-tetrahydropyrene by hydrogen reaction under a Pd / C catalyst, and in aqueous solution under FeCl ₃ · H ₂ O catalyst. Bromine solution was slowly added dropwise to make 2,7-dibromo-4,5,9,10-tetrahydrodroprene, followed by CS ₂ Bromine is then added dropwise to produce the desired 2,7-dibromopyrene.

The inventors synthesized and evaluated compounds having substituents of various structures as examples of the compound represented by Formula 1, and the electron affinity was found in the range of 3.3-1.9 eV depending on the substituent, and the ionization potential was 6.2-5.0 eV, Bandgap energy was found at 2.0-3.4 eV. From this, the compound represented by the formula (1) according to the present invention is not only an application as a blue light emitting material, but also a hole injection / transport layer, an electron injection / transport layer, a host material (red, green, blue) for phosphorescent devices, It was confirmed that the fluorescent element can also be applied as a host material.

Hereinafter, an organic light emitting display device including the compound of Chemical Formula 1 described above as another aspect of the present invention in an organic layer will be described in detail.

1 is a cross-sectional view showing an embodiment of an organic light emitting display device according to the present invention.

The organic electroluminescent device according to the present invention is a form in which a first electrode, an organic material layer including one or more layers including a light emitting layer, and a second electrode are sequentially stacked, and one or more layers of the organic material layers include the compound of Formula 1.

The specific implementation method of the organic light emitting device comprising the compound of Formula 1 in the light emitting layer is as follows.

A transparent electrode pattern was formed on the substrate as a first electrode, and then a hole injection layer, a hole transport layer, a light emitting layer including the compound of Formula 1, an electron transport layer, and an electron injection layer were sequentially formed. By forming the organic electroluminescent device can be implemented.

In this case, indium tin oxide (ITO) having electrical conductivity and transparency at the same time is mainly used. In addition, the substrate may be provided with a thin film transistor (TFT), and when the TFT is provided, an active matrix type electroluminescent device may be manufactured, and when the TFT is not provided, the passive matrix may be passive. type) Electroluminescent device can be manufactured. In the present invention, either an active drive type or a passive drive type may be used. In addition, the substrate can be used, such as glass, plastic, metal foil, and is not particularly limited.

The hole injection layer is not particularly limited, and the compound of formula 1 according to the present invention may be used, or a material known in the prior art may be used. The hole injection layer is preferably a material that has a smoothing function on the surface of the transparent electrode and has excellent interfacial characteristics with the transparent electrode and can easily give electrons to the transparent electrode. Conventionally known representative hole injection material is the same as the formula (7) (DNTPD), it is preferable to form a thickness of about 300 ~ 1200 mm 3.

<Formula 7>

The hole transport layer is a material that has a high physical and chemical similarity to the hole injection layer, and like the hole injection layer, a material that can easily give electrons, that is, a material that can easily transport holes, is not particularly limited. The hole injection layer may be a novel compound according to the present invention, or may be a material known in the art. Representative hole transport material according to the prior art is the same as the formula (8) (NPD), it is preferable to form a thickness of about 300 ~ 500 kPa by heat deposition under vacuum.

<Formula 8>

Next, formation of the light emitting layer is required. In the case of a full color display, a red light emitting layer, a green light emitting layer and a blue light emitting layer should be formed in the pixel. That is, it is preferable that the substrate having the hole transport layer formed is disposed in a vacuum chamber of 10 ⁻⁶ torr, and the compound of the present invention is heated to be deposited at a rate of 5 kW / sec to form a light emitting layer having a thickness of 300 kW.

The light emitting layer may be a compound of Formula 1 may be used alone or a second component may be included.

In this case, the compound of Formula 1 of the present invention may be a host material, a dopant material, and both the host and the dopant may use the compound according to the present invention. If the compound of Formula 1 according to the present invention is used as a dopant, the host material may use various materials described in the prior art. In addition, when the compound of Formula 1 according to the present invention is applied as a host material, the following may be used as the dopant material.

Green dopant is 10- (2-benzothiazolyl) -1,1,7,7-tetramethyl-2,3,6,7-tetrahydro-1H, 5H, 11H- [1] benzopyrano [ 6,7,8-ij] quinolzin-11-one, its derivatives and quinacridone derivatives are possible; red dopants include Kodak's DCJTB and its derivatives, Sony's 1,1'-dicyano -Substituted bisstyryl naphthalene or the like can be used, and as blue dopant, diphenylamino-di (styryl) arylene can be used.

As the phosphorescent dopant, Ir or Pt-based organometallic complexes can be used, and green, blue and red light can be emitted depending on the type of the ligand constituting the Ir or Pt complex. Examples include 2,3,7,8,12,13,17,18-octaethyl-12H, 23H-porphyrinplatinum (II) (PtOEP), a red phosphorescent material, and fac-tris (2-phenylpyridine), a green phosphorescent material. ) Iridium (Ir (ppy) ₃ ], bis (2- (2'-benzo [4,5-a] thienyl) pyridinato-N, C ^{2 '} ) iridium (acetylacetonate), a red phosphorescent material ( and the like Btp ₂ Ir (acac), a blue phosphorescent material fac- tris [2- (4,5'- difluoro-phenyl) pyridine -N, C ^'3] iridium (III) (FIrppy).

Representative structures of the blue, red, and green dopants described above are shown in Chemical Formulas 9, 10, and 11, respectively.

<Formula 9>

<Formula 10>

<Formula 11>

If a phosphorescent dopant is used as a dopant, a hole blocking layer (HBL) may be added between the light emitting layer and the electron transport layer. If the hole blocking layer is formed, more excellent efficiency can be obtained. The hole blocking layer may be a compound of the formula (1) according to the present invention, it may be used a material known in the prior art. Examples of the hole blocking layer material include 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP) and the like.

Formation of an electron transport layer is required on the light emitting layer or on the hole blocking layer, and the compound of Chemical Formula 1 according to the present invention may be used, or various known materials may be used. That is, it is preferable to include an electron accepting group so that electrons can be easily transferred to the light emitting layer, and the following general formula (12) is a representative material known in the art. Since the formation position of the exciton is affected by the thickness of the electron transport layer, the film thickness must be properly adjusted. In other words, if the electron transport layer is too thick, the light emitting region is biased to the electron transport layer, and thus some light emission occurs in the electron transport layer. On the other hand, if formed too thin, there is a disadvantage that the life is reduced, so about 200 ~ 400 Å is suitable.

<Formula 12>

An electron injection layer is formed on the electron transport layer, and LiF is used a lot in industry. A cathode, which is a second electrode, is formed on the electron injection layer. Al, Ma, Ag, or the like can be used as a single metal, and LiF / Ca (or Ba) / It also uses a cathode of Al structure. After cathode formation, the electroluminescent device is completed through an encapsulation process to block the atmosphere.

As described above, the structural features and manufacturing method of the compound of Formula 1 according to the present invention and the method of implementing the electroluminescent device using the same have been described, but the present invention is not limited to the above-described range. That is, according to the type of substituent in Formula 1, it is also possible to implement the green light emitting material, the host material of the light emitting layer, the hole transport material and the electron transport material.

Hereinafter, a method for preparing a novel compound according to the present invention and a method for implementing an organic light emitting display device including the same are described in detail by way of examples. However, the present invention is only limited to the following examples, which are presented to aid the understanding of the present invention. no.

Example 1

First, pyrene (20 g) was dissolved in CCl ₄ (carbon tetrachloride, 500 mL), and bromine (10 mL) dissolved in CCl ₄ (500 mL) was slowly added dropwise and reacted at room temperature for 12 hours. After completion of the reaction, the precipitate produced during the reaction (14 g) was recrystallized under purified toluene to obtain 1,6-dibromopyrene, and 1,6-dibromopyrene ( 1a ) was vacuumed to obtain a pure substance. After drying with a dryer using a sublimation (sublimation) purification equipment equipped with a turbopump to obtain a high purity 1a . 9H-pyrido [3,4- b ] indole (2.34g, 13.9mmol), K ₂ CO ₃ (3.1g, 22.3mmol) as 1a (2.0 g, 5.56 mmol) and the nitrogen atom-containing heterocyclic compound obtained Was dissolved in nitrobenzene (20 mL) and then refluxed and stirred at 160 ° C. for 12 hours. After confirming the reaction termination by TLC, nitrobenzene was removed under reduced pressure, the product was extracted using water and EtOAc, and water was removed with anhydrous magnesium sulfate, and then the solvent was removed under reduced pressure. The product was separated and purified using a silica gel column to give pure 1,6-di (9H-pyrido [3,4- b ] indol-9-yl) pyrene (Compound 1 ). The synthesis process is shown in FIG. Synthesized Compound 1 was dried with a vacuum dryer, and a high purity material of about 99.8% was obtained by using a sublimation purification apparatus equipped with a turbopump. ¹ H NMR spectrum of Compound 1 is shown in FIG. 3.

ITO glass having a sheet resistance of 30 Ω / cm 2, a thickness of 1.08 mm and a light transmittance of 80% or more was cut to a size of 2 cm × 2 cm, followed by nitric acid (70%), hydrochloric acid and distilled water. Part of the ITO layer was partially removed using an etchant mixed at a ratio of 210: 80. In addition, the etched ITO glass was placed in a beaker containing acetone and washed with an ultrasonic cleaner for 15 minutes, and then placed in CA-40 (Cyantek Co.), an ITO glass cleaning solution, for 15 minutes. Finally washed several times with deionized water and dried for 1 hour at 120 ℃.

DNTPD was formed on the substrate on which the transparent electrode pattern formation and cleaning was completed as a hole injection material to a thickness of 700 Å by vacuum heating evaporation method, and NPD was formed to a thickness of 300 Å as the hole transport material. Subsequently, the compound 1 synthesized and purified as described above as a light emitting layer and a green phosphorescent dopant were formed at a ratio of 95: 5 to form a thickness of 300 kPa, and then BCP was formed to a thickness of 100 kPa as the hole blocking layer. Subsequently, Alq3, which is an electron transport layer, was formed to have a thickness of 250 kHz. LiF was formed to have a thickness of 10 송 on the upper portion of the electron transport layer, and Al was formed to have a thickness of 1500 Å on the upper portion. The fabricated electroluminescent device was cut off from the atmosphere using a glass cap.

When a direct current was applied by connecting a positive electrode to ITO and a negative electrode to Al, green light emission of color coordinates x = 0.31 and y = 0.55 was obtained from the light emitting layer composed of Compound 1 and phosphorescent dopant. At this time, no emission of light by Compound 1 was observed. From this, it can be seen that energy transfer from Compound 1 to phosphorescent dopant occurs easily. The green light emission spectrum is shown in FIG. 4.

Example 2

First, 1a (2.0 g, 5.56 mmol), benzoimidazole (1.68 g, 13.9 mmol), and K ₂ CO ₃ (3.1 g) made by the method described in Example 1 were dissolved in nitrobenzene (20 mL), The mixture was refluxed and stirred at 160 ^° C. for 12 hours. After confirming the reaction termination by TLC, nitrobenzene was removed under reduced pressure, the product was extracted using water and EtOAc, and water was removed with anhydrous magnesium sulfate, and then the solvent was removed under reduced pressure. The product was separated and purified using a silica gel column to obtain pure 1- (1- (1 H -benzo [d] imidazol-1-yl) pyren-6-yl) -1 H -benzo [d] imidazole (Compound 2 ) Synthesized Compound 2 was dried with a vacuum dryer, and a high purity material of about 99.8% was obtained using a sublimation purification apparatus equipped with a turbopump. A synthesis process of Compound 2 is shown in FIG. 5, and its ¹ H NMR analysis result is shown in FIG. 6.

After the ITO glass was cleaned by the method described in Example 1, DNTPD was formed to have a thickness of 700 kPa by the vacuum heating evaporation method as a hole injection material, and NPD was formed to have a thickness of 300 kPa as the hole transport material. Subsequently, Compound 2, which was synthesized and purified by the method described above as a light emitting layer, was formed to a thickness of 300 GPa, and then Alq3, which is an electron transport layer, was formed to a thickness of 250 GPa. LiF was formed to a thickness of 10 Å on the electron transport layer, and Al was formed on the upper portion of 1500 Å. The fabricated electroluminescent device was cut off from the atmosphere using a glass cap.

When a direct current was applied by connecting a positive electrode to ITO and a negative electrode to Al, a high color purity blue light emission (x = 0.14, 0.15) was obtained from Compound 2 , and the blue light emission spectrum thereof is shown in FIG. 7.

Example 3

1a (2.0 g, 5.56 mmol), imidazole (960 mg, 13.9 mmol), and K ₂ CO ₃ (3.1 g) prepared by the method described in Example 1 were dissolved in nitrobenzene (20 mL), followed by 12 at 160 ° C. It was refluxed and stirred for hours. After confirming the reaction termination by TLC, nitrobenzene was removed under reduced pressure, the product was extracted using water and EtOAc, and water was removed with anhydrous magnesium sulfate, and then the solvent was removed under reduced pressure. The product was separated and purified using a silica gel column to give pure 1- (1- (1 H -imidazol-1-yl) pyren-6-yl) -1 H -imidazole (Compound 3 ). Synthesized Compound 3 was dried with a vacuum dryer, and a high purity material of about 99.8% was obtained by using a sublimation purification apparatus equipped with a turbopump. The synthesis process of Compound 3 is shown in FIG. 8, and its ¹ H NMR analysis is shown in FIG. 9. Using the synthesized compound 3 as a light emitting layer, an electroluminescent device was manufactured in the same manner as in Example 2. When a direct current was applied by connecting a positive electrode to ITO and a negative electrode to Al, blue light emission (x = 0.15, 0.15) having excellent color purity was obtained from compound 3 , and the blue light emission spectrum thereof is shown in FIG. 10.

Example 4

In order to make compound 4 , pyrene (4.2 g) was first dissolved in ethyl acetate (50 mL), and Raney nickel (2.0 g) was added thereto and reacted at room temperature for 48 hours. After confirming the completion of the reaction by TLC, the catalyst was removed using a celite column, pd / C (1.0 g) was added thereto, and the mixture was hydrogenated again at room temperature under hydrogen pressure of about 100 psi for 72 hours. After completion of the reaction, the solvent was removed under reduced pressure, and the product was separated and purified using a silica gel column to obtain pure 4,5,9,10-tetrahydropyrene ( 4a , 3.2g). Thus obtained 4,5,9,10-tetrahydropyrene (3.2 g, 15.5 mmol) and FeCl ₃ H ₂ O (52 mg) catalyst were added to distilled water (310 mL) and bromine (1.6 mL) dissolved in distilled water (166 mL). ) Was slowly added for 4 hours and the reaction proceeded at room temperature for 24 hours. After confirming the reaction, the precipitate was filtered and recrystallized under benzene to obtain pure 2,7-dibromo-4,5,9,10-tetrahydropyrene ( 4b 4.7g). To make 2,7-dibromopyrene, 4b (4.4 g) was dissolved in CS ₂ (300 mL), followed by CS ₂ Bromine (1.37mL) dissolved in (300mL) was slowly added dropwise and reacted at room temperature for 72 hours. After completion of the reaction, the solvent was removed under reduced pressure and the resulting product was recrystallized under chlorobenzene to give pure 2,7-dibromopyrene ( 4c , 3.07 g).

4c (2.0 g, 5.56 mmol), imidazole (960 mg), and K ₂ CO ₃ (3.1 g) were dissolved in nitrobenzene (20 mL), and then refluxed and stirred at 160 ° C. for 12 hours. After confirming the reaction termination by TLC, nitrobenzene was removed under reduced pressure, the product was extracted using water and EtOAc, and water was removed with anhydrous magnesium sulfate, and then the solvent was removed under reduced pressure. The product was separated and purified using a silica gel column to give pure 1- (2- (1 H -imidazol-1-yl) pyren-7-yl) -1 H -imidazole (Compound 4 ). Synthesis of Compound 4 is shown in FIG. 11. Synthesized Compound 4 was dried with a vacuum dryer, and a high purity material of about 99.8% was obtained by using a sublimation purification apparatus equipped with a turbopump. Compound 4 has an isomer relationship with Compound 3 synthesized in Example 3, and the characteristics of the electroluminescent device were similar.

1 is a cross-sectional view showing an embodiment of an organic light emitting display device according to the present invention.

2 is a scheme showing the synthesis of Compound 1.

3 is a ¹ H NMR spectrum of Compound 1 synthesized.

4 is a light emission spectrum of an organic field device having a light emitting layer containing compound 1 and a phosphorescent dopant.

5 is a scheme showing the synthesis of Compound 2.

6 is a ¹ H NMR spectrum of Compound 2 synthesized.

7 is a light emission spectrum of an organic field device having a light emitting layer containing compound 2. FIG.

8 is a scheme showing the synthesis of Compound 3.

9 shows the results of ¹ H NMR analysis of the synthesized compound 3 in FIG. 9.

10 is an emission spectrum of an organic field device having an emission layer containing compound 3. FIG.

11 is a scheme showing the synthesis of Compound 4.

Claims (11)

Compound represented by the following formula (1): <Formula 1>

Here, A is an amine cyclic compound having a nitrogen atom (N) and a CN double bond (> C = N-) at the same time, the carbon atom of pyrene as the central group and the nitrogen atom of the amine cyclic compound are covalently bonded. And k is selected from 1, 2, 3, and 4 as the number of As substituted in the pyrene, and when k is 2 or more, each A may be the same as or different from each other. The compound of claim 1, wherein A is one or more substituents selected from the group of substituents represented by the following Formula 2: <Formula 2>

Wherein Y ₁ to Y ₁₈ are each independently a hydrogen group, a halogen group, an alkyl group, an alkoxy group, a cyano group, a nitro group, an acyl group, a substituted or unsubstituted amino group, a substituted or unsubstituted aryl group, and a substitution. Or an unsubstituted heterocyclic group. In an organic light emitting display device comprising a first electrode, an organic material layer including one or more layers including a light emitting layer, and a second electrode sequentially stacked, one or more layers of the organic material layers include an organic light emitting device comprising a compound represented by the following Chemical Formula 1 : <Formula 1>

Here, A is an amine cyclic compound having a nitrogen atom (N) and a CN double bond (> C = N-) at the same time, the carbon atom of pyrene as the central group and the nitrogen atom of the amine cyclic compound are covalently bonded. And k is selected from 1, 2, 3, and 4 as the number of As substituted in the pyrene, and when k is 2 or more, each A may be the same as or different from each other. The organic light emitting device of claim 3, wherein the organic material layer includes a hole injection layer, and the hole injection layer includes the compound of Formula 1. 5. The organic light emitting device of claim 3, wherein the organic material layer includes a hole transport layer, and the hole transport layer comprises a compound of Formula 1. The organic electroluminescent device according to claim 3, wherein the light emitting layer comprises the compound of Chemical Formula 1. The organic light emitting device of claim 3, wherein the light emitting layer comprises a host and a dopant, and the host material is a compound represented by Chemical Formula 1. 5. 4. The organic light emitting device of claim 3, wherein the light emitting layer comprises a host and a dopant, and the dopant material is the compound of Formula 1. The organic light emitting device of claim 3, wherein the organic material layer comprises a hole blocking layer, and the hole blocking layer comprises a compound of Formula 1. 5. The organic electroluminescent device according to claim 3, wherein the organic material layer comprises an electron transport layer, and the electron transport layer comprises the compound represented by Chemical Formula 1. The organic light emitting device of claim 8, further comprising a hole blocking layer between the light emitting layer and the electron transport layer when the dopant is a phosphorescent dopant.

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