KR101415730B1 - Aromatic compound derivatives and organic electroluminescent device using the same - Google Patents

Abstract

상기 화학식 1 중 L₁ 내지 L₄, X₁은 각각 독립적으로 특정 구조를 갖는 치환 또는 비치환 아릴기이고 R₁은 각각 독립적으로 수소 원자, 알킬기 등을 나타내고, 인접한 기가 서로 결합하여 포화 또는 불포화 탄소 고리를 형성할 수 있다. The present invention relates to an aromatic compound derivative and an organic electroluminescent device using the aromatic compound derivative, and to provide an aromatic compound derivative represented by the following formula (1) and an organic electroluminescent device including the same.
[Chemical Formula 1]

Wherein L ₁ to L ₄ and X ₁ each independently represent a substituted or unsubstituted aryl group having a specific structure and each R ₁ independently represents a hydrogen atom, an alkyl group, or the like, adjacent groups are bonded to each other to form a saturated or unsaturated carbon A ring can be formed.

Description

TECHNICAL FIELD [0001] The present invention relates to an aromatic compound derivative and an organic electroluminescent device using the same. BACKGROUND ART [0002] AROMATIC COMPOUND DERIVATIVES AND ORGANIC ELECTROLUMINESCENT DEVICE USING THE SAME [0003]

TECHNICAL FIELD The present invention relates to an aromatic compound derivative and an organic electroluminescent device using the same, and more particularly, to a novel aromatic compound derivative applicable to an organic electroluminescent device, a method for producing the same, and an organic electroluminescent device using the same. The organic electroluminescent device according to the present invention exhibits excellent characteristics in terms of efficiency, driving voltage and lifetime.

Organic electroluminescent (EL) devices using organic materials or organic light emitting diodes are one of typical flat panel display devices together with liquid crystal display, plasma display panel and field emission display. The organic electroluminescent device has various advantages in the manufacturing process compared to the conventional flat panel display device, has excellent high luminance and viewing angle characteristics, has a high response speed and low driving voltage, and can be used as a flat panel display such as a wall- Development is actively being made to be used.

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The organic electroluminescent device is generally composed of organic thin films disposed between two opposing electrodes and has a multilayer thin film structure in order to enhance its efficiency and stability. When the electric field is applied, the light emitting path recombines the holes injected from the anode and the electrons injected from the cathode to form an exciton, which is an electron-hole pair. The exciton returns to the ground state and transfers the corresponding energy to the light emitting material It is converted to light. In recent years, a method of doping a small amount of fluorescent or phosphorescent material into a light emitting layer forming an exciton has been used in order to increase the color purity and efficiency of light to emit light. As one of them, the development of a material for use in a blue light emitting device having a high luminous efficiency and a long life span is under development.

For example, EP 0610514 discloses stilbene compounds and devices using them. However, although the device disclosed herein emits blue light having a high luminous efficiency, it has low color purity and low lifetime, which is not practical. Practically used as a blue pixel for a color display is specifically required to have an x-coordinate of 0.15, a y-coordinate of 0.15 or less, and a half-life of 10,000 hours or more based on the 1931 CIE color coordinate system.

Accordingly, the present inventors have found an aromatic compound derivative having a novel structure. In addition, when the organic compound layer of the organic electroluminescent device is formed using the novel aromatic compound derivative, the efficiency of the device, the driving voltage drop, and the stability can be increased. And that it is exerted.

Although the inventions of US 2006/0261328 A1, US 005736284 A, and US 20050044017 A1 and the Korean patent application No. 10-2006-0080011 include a structure similar to the present invention, The synthesis process is easy, and the performance is further improved in terms of device efficiency, driving voltage, and lifetime.

Accordingly, it is an object of the present invention to provide a novel aromatic compound derivative and an organic electroluminescent device using the same.

상기 화학식 1 중 L₁ 내지 L₄, X₁은 각각 독립적으로 특정 구조를 갖는 치환 또는 비치환 아릴기이고 R₁은 각각 독립적으로 수소 원자, 알킬기 등을 나타내고, 인접한 기가 서로 결합하여 포화 또는 불포화 탄소 고리를 형성할 수 있다.
구체적으로, 본 발명은 하기 구조식으로 표시되는 화합물 그룹 중에서 선택된 방향족 화합물 유도체를 제공한다:

.
또한, 상기 방향족 화합물 유도체는 유기전계 발광소자(OLED), 유기태양전지(OSC), 전자종이(e-Paper), 유기감광체(OPC) 및 유기트랜지스터(OTFT)로 이루어진 그룹 중에서 선택된 어느 하나에 적용되는 것을 특징으로 하는 방향족 화합물 유도체를 제공한다.
또한, 제1 전극, 제2 전극 및 이들 전극 사이에 배치된 1층 이상의 유기물층을 포함하며, 상기 유기물층의 적어도 1층 이상이 상기 방향족 화합물 유도체를 포함하는 것을 특징으로 하는 유기전계 발광소자를 제공한다.
또한, 상기 방향족 화합물 유도체를 포함하는 층은 발광층, 호스트, 전자층 또는 정공층인 것을 특징으로 하는 유기전계 발광소자를 제공한다.
또한, 상기 유기물층은 정공주입층, 정공수송층, 정공저지층 및 전자수송층으로 이루어진 그룹 중에서 적어도 하나 이상을 더 포함하는 것을 특징으로 하는 유기전계 발광소자를 제공한다.In order to solve the above-mentioned problems, the present invention provides an aromatic compound derivative represented by the following formula (1) and an organic electroluminescent device comprising the same:
[Chemical Formula 1]

Wherein L ₁ to L ₄ and X ₁ each independently represent a substituted or unsubstituted aryl group having a specific structure and each R ₁ independently represents a hydrogen atom, an alkyl group, or the like, adjacent groups are bonded to each other to form a saturated or unsaturated carbon A ring can be formed.
Specifically, the present invention provides an aromatic compound derivative selected from the group of compounds represented by the following structural formulas:

.
The aromatic compound derivative may be applied to any one selected from the group consisting of an organic electroluminescent device (OLED), an organic solar cell (OSC), an electronic paper (e-paper), an organic photoconductor (OPC) Wherein the aromatic compound is an aromatic compound.
Also, there is provided an organic electroluminescent device comprising a first electrode, a second electrode, and at least one organic material layer disposed between the electrodes, wherein at least one layer of the organic material layer comprises the aromatic compound derivative .
In addition, the layer containing the aromatic compound derivative may be a light emitting layer, a host, an electron layer, or a hole layer.
Further, the organic material layer may further include at least one or more of the group consisting of a hole injection layer, a hole transport layer, a hole blocking layer, and an electron transport layer.

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As described in detail above, the novel aromatic compound derivative of the present invention can be easily synthesized by carrying out only a two-step reaction, and the organic electroluminescent device using the aromatic compound derivative is further improved in device efficiency, driving voltage, effective.

 Thus, the organic electroluminescent device of the present invention can be used in various organic electroluminescent devices such as a flat panel display such as a wall-hanging TV or a backlight of a display. The aromatic compound derivative according to the present invention may have various properties depending on the kind of the substituent, and thus can perform all the functions of hole injection, hole transport, electron injection and transport according to the substituent, It is expected to contribute to the improvement of the display industry by providing an electroluminescent device.

1 is a PL spectrum of an embodiment (DSA-Cz) of the present invention,
2 is a PL spectrum of an embodiment (DSA-flu) of the present invention,
3 is a PL spectrum of an embodiment (DSA-spiro) of the present invention,
4 is a cross-sectional view of a simplified OLED configuration according to the present invention,
5 is a cross-sectional view of a multi-layer structure of an OLED according to the present invention.

상기 화학식 1 중 L₁ 내지 L₄, X₁은 각각 독립적으로 특정 구조를 갖는 치환 또는 비치환 아릴기이고 R₁은 각각 독립적으로 수소 원자, 알킬기 등을 나타내고, 인접한 기가 서로 결합하여 포화 또는 불포화 탄소 고리를 형성할 수 있다.
구체적으로, 본 발명은 하기 구조식으로 표시되는 화합물 그룹 중에서 선택된 방향족 화합물 유도체를 제공한다:

.
상기 화합물은 구조적 특이성으로 인하여 유기전계 발광소자 및 유기전자소자에서 유기물층으로 사용될 수 있다.The present invention relates to a novel blue light emitting layer material capable of significantly improving the lifetime and luminous efficiency of an organic electroluminescent device, and an organic electroluminescent device having high blue luminescent purity using the same, wherein the aromatic compound derivative represented by the following formula And an organic electroluminescent device comprising the same:
[Chemical Formula 1]

Wherein L ₁ to L ₄ and X ₁ each independently represent a substituted or unsubstituted aryl group having a specific structure and each R ₁ independently represents a hydrogen atom, an alkyl group, or the like, adjacent groups are bonded to each other to form a saturated or unsaturated carbon A ring can be formed.
Specifically, the present invention provides an aromatic compound derivative selected from the group of compounds represented by the following structural formulas:

.
Due to the structural specificity, the compound can be used as an organic material layer in organic electroluminescent devices and organic electronic devices.

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The present invention further provides an organic electroluminescent material comprising an aromatic compound derivative as described above.

The organic electroluminescent material may be produced by a conventional method and materials for manufacturing an organic electroluminescent device, except that one or more organic material layers are formed using the above aromatic compound derivative.

That is, the organic electroluminescent device of the present invention includes a first electrode, a second electrode, and at least one organic material layer disposed between the electrodes, wherein at least one layer of the organic material layer includes the aromatic compound derivative do.

In the organic electroluminescent device of the present invention, the organic material layer includes a hole injecting layer, a hole transporting layer, a light emitting layer, a hole blocking layer, and an electron transporting layer, and may further include one or more of a hole injecting layer, a hole transporting layer, Two layers can be used with the layer omitted.

For example, in the organic electroluminescent device of the present invention, the organic layer includes a hole layer, a light emitting layer, or an electron layer, and the hole layer, the light emitting layer, or the electron layer may include the aromatic compound derivative of the present invention.

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In one embodiment of the present invention, the organic electroluminescent device may have a structure including an anode of the first electrode, a cathode of the second electrode, and an organic material layer disposed therebetween as shown in FIGS. 4 and 5, The organic electroluminescent device can be manufactured using a conventional method and material for manufacturing an organic electroluminescent device, except that the compound according to the present invention is used for one or more layers of the organic material layer of the organic electroluminescent device.

In the organic electroluminescent device of the present invention, the organic layer may have a single-layer structure or a multilayer structure of two or more layers including a light-emitting layer. When the organic compound layer of the organic electroluminescent device of the present invention has a multi-layer structure, the organic compound layer may be formed by a hole injection layer, a hole transport layer, an electroluminescence layer, a hole blocking layer, Transport layer (Electron Transport Layer) or the like may be stacked.

However, the structure of the organic electroluminescent device is not limited to this, and may include fewer organic layers. The compound according to the present invention can be used for a hole injecting layer, a hole transporting layer, a light emitting layer, a hole blocking layer, and a hole transporting layer in a multi-layer organic compound layer. The hole injecting layer, the hole transporting layer, the light emitting layer, A layer that simultaneously transports holes and light emission, a layer that simultaneously transports holes and emits light, a layer that performs electron transport and light emission, an electron transport layer, an electron injection and transport layer, and the like.

For example, the structure of the organic electroluminescent device of the present invention may have a structure as shown in Figs. 4 and 5, but is not limited thereto.

The organic electroluminescent device according to the present invention may be formed by using a known physical vapor deposition (PVD) method such as sputtering or e-beam evaporation to form a metal oxide or a metal oxide having conductivity on the substrate, An anode is formed by depositing an alloy on the anode, and an organic material layer including a hole injecting layer, a hole transporting layer, a light emitting layer, a hole blocking layer and an electron transporting layer is formed thereon, and then a substance usable as a cathode is deposited thereon .

In addition to such a method, an organic electroluminescent device may be formed by sequentially depositing a cathode material, an organic material layer, and a cathode material on a substrate.

The organic material layer may have a multi-layer structure including a hole injection layer, a hole transport layer, a light emitting layer, a hole blocking layer, and an electron transport layer, but is not limited thereto and may have a single layer structure. The organic material layer may be formed using a variety of polymer materials by a method such as a solvent process such as spin coating, dip coating, doctor blading, screen printing, inkjet printing, .

As the anode material, a material having a large work function is preferably used so that hole injection can be smoothly conducted into the organic material layer. Specific examples of the cathode material that can be used in the present invention include metals such as vanadium, chromium, copper, zinc, and gold, or alloys thereof; Metal oxides such as zinc oxide, indium oxide, indium tin oxide (ITO), titanium oxide (TiO), and indium zinc oxide (IZO); ZnO: Al or SnO _2: a combination of a metal and an oxide such as Sb; Conductive polymers such as poly (3-methylthiophene), poly [3,4- (ethylene-1,2-dioxy) thiophene] (PEDOT), polypyrrole and polyaniline.

The negative electrode material is preferably a material having a small work function to facilitate electron injection into the organic material layer. Specific examples of the negative electrode material include metals such as magnesium, calcium, sodium, potassium, titanium, indium, yttrium, lithium, gadolinium, aluminum, silver, tin and lead or alloys thereof; Layer structure materials such as LiAl and LiF / Al or LiO ₂ / Al, but the present invention is not limited thereto.

As the hole injecting material, it is preferable that the highest occupied molecular orbital (HOMO) of the hole injecting material be between the work function of the anode material and the HOMO of the surrounding organic layer. It is also preferable to use a material having a surface adhesion with the anode and a planarizing ability capable of alleviating the surface roughness of the anode. And a material having HOMO and LUMO values larger than the bandgap of the light emitting layer is preferable. Materials having high chemical stability and thermal stability are also desirable.

Specific examples of the hole injecting material include metal porphyrine, oligothiophene, arylamine-based organic materials, hexanitrile hexaazatriphenylene-based organic materials, quinacridone-based organic materials, perylene , Anthraquinone, polyaniline and polythiophene-based conductive polymers, but the present invention is not limited thereto.

As the hole transporting material, a material capable of transporting holes from the anode or the hole injection layer to the light emitting layer and having high HOMO and LUMO values larger than the bandgap of the light emitting layer. Materials with high chemical stability and thermal stability are also suitable.

Specific examples include arylamine-based organic materials, conductive polymers, and block copolymers having a conjugated portion and a non-conjugated portion together, but are not limited thereto.

As the light emitting material, a material capable of emitting light in the visible light region by transporting and combining holes and electrons from the hole transporting layer and the electron transporting layer, respectively, is preferably a material having good quantum efficiency.

Specific examples thereof include blue-based ADN or MADN, DPVBi, BAlq, etc., green-based Alq ₃ and other anthracene, pyrene, fluorene, spiro fluorene, carbazole, benzoxazole, benzothiazole, A compound represented by the azole series, and a polymeric poly (p-phenylenevinylene), polypyrene, polyfluorene, and the like, but are not limited thereto.

As the hole blocking layer material, a material larger than the HOMO value of luminescence is suitable. Materials with high chemical stability and thermal stability are also suitable.

Specifically, TPBi and BCP are mainly used, and CBP, PBD, PTCBI, BPhen, and the like can be used, but not limited thereto.

As the electron transporting material, a material capable of transferring electrons from the cathode well into the light emitting layer, which is highly mobile, is suitable. Materials with high chemical stability and thermal stability are also suitable.

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Specific examples include an Al complex of 8-hydroxyquinoline; Complexes containing Alq ₃ ; Organic radical compounds; Hydroxyflavone-metal complexes, and the like, but are not limited thereto.

The organic electroluminescent device according to the present invention may be a front emission type, a back emission type, or a both-sided emission type, depending on the material used. The compound according to the present invention can be applied to organic electroluminescent devices including an organic solar cell (OSC), an organic photoconductor (OPC), an organic transistor (OTFT), an electronic paper (e-paper) Lt; / RTI >

Hereinafter, preferred embodiments of the present invention will be described in order to facilitate understanding of the present invention. However, the following examples are provided only for the purpose of easier understanding of the present invention, and the present invention is not limited thereto.

Synthetic example  One: [ Intermediate 1 -1]

To a dried two-neck flask was dissolved 10 g (38.29 mmol) of 4-bromobenzophenone and 10.48 g (45.95 mmol) of diethylbenzylphosphonate in 120 ml of tetrahydrofuran (THF) under nitrogen atmosphere , And 5.15 g (45.49 mmol) of potassium tert-butoxide was dissolved in 45.8 ml of THF and slowly dropped. When the dropwise addition was completed, the mixture was reacted at 80 ° C for 12 hours.

The reaction solution was cooled to room temperature, and THF was removed under reduced pressure. The resulting solid was dissolved in 250 ml of dichloromethane and 250 ml of water was added to extract it. The obtained organic layer was dried over anhydrous magnesium sulfate and purified through a column to obtain 1-bromo-4- (1,2-diphenylvinyl) benzene (intermediate 1-1) in a yield of 81%.

Synthetic example  2: Compound [1] ( DSA - Cz )

To a dried two-neck flask was added 1.0 eq. Of 0.335 g (1 mmol) of Intermediate 1-1, 3.0 g of 3- (4- (4,4,5,5-tetramethyl-1,3,2- (1 mmol) and 0.035 g (0.03 mmol) of tetrakis (triphenylphosphine) palladium (0) were charged into the flask and sufficiently filled with nitrogen. Then, a 2M aqueous solution of potassium carbonate dissolved in distilled water and 30 mL of anhydrous toluene were added, followed by stirring at 90 DEG C for 24 hours.

After the completion of the reaction, the toluene was removed by distillation under reduced pressure, and the mixture was extracted with purified water and methylene chloride. The organic layer was distilled under reduced pressure with anhydrous magnesium sulfate. The vacuum distilled mixture was separated into a column to obtain a compound [1].

Synthetic example  3: Compound [7] ( DSA - flu )

To a dried two-neck flask was added 0.3 eq. (1 mmol) of Intermediate 1-1, 1.0 eq, and 9,10-dimethyl-9H-fluoren-2-yl-2-boronic acid 0.238 g (1 mmol) And 0.035 g (0.03 mmol) of tetrakis (triphenylphosphine) palladium (0) were charged, followed by sufficiently filling with nitrogen. Then, a 2M aqueous solution of potassium carbonate dissolved in distilled water and 30 mL of anhydrous toluene were added, followed by stirring at 90 DEG C for 24 hours.

After the completion of the reaction, the toluene was removed by distillation under reduced pressure, and the mixture was extracted with purified water and methylene chloride. The organic layer was distilled under reduced pressure with anhydrous magnesium sulfate. The vacuum distilled mixture was separated into a column to obtain a compound [7].

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Synthetic example  4: Compound [13] ( DSA - spiro )

A dried two-neck flask was charged with 1.0 eq. Of Intermediate 1-1 (1.0 mmol), 0.3 eq. (1 mmol) of 2-spiroboronic acid, 1 eq. Of tetrakis (triphenylphosphine) palladium (0.03 mmol) of N, N-dimethylformamide (NMP) was added, and then nitrogen was sufficiently charged. Then, a 2M aqueous solution of potassium carbonate dissolved in distilled water and 30 mL of anhydrous toluene were added, followed by stirring at 90 DEG C for 24 hours.

After the completion of the reaction, the toluene was removed by distillation under reduced pressure, and the mixture was extracted with purified water and methylene chloride. The organic layer was distilled under reduced pressure with anhydrous magnesium sulfate. The reduced pressure distilled mixture was separated into a column to give compound [13].

Example

In the experimental examples, CuPc was used for HIL, NPB for HTL, MADN, DSA-Cz, DSA-flu and DSA-spiro were used as luminescent materials. Alq ₃ or TPBi for ETL and LiF for EIL were used.

Comparative Example 1: ITO / CuPc / NPB / MADN / Alq 3 / LiF / Al

An organic electroluminescent device was fabricated using the aromatic compounds according to each of the above Preparation Examples. CuPc for HIL, NPB for HTL, MADN for light emitting material, Alq _{3 for} ETL, and LiF for EIL were used.

A glass substrate coated with ITO (indium tin oxde) thin film having a thickness of 1500 Å was placed in a second distilled water containing detergent and washed with ultrasonic waves. The ITO was washed for 30 minutes and then washed twice with distilled water and ultrasonically cleaned for 10 minutes. After the distilled water was washed, it was ultrasonically washed with a solvent of isopropyl alcohol, acetone, and methanol, dried, and then transferred to a plasma cleaner. The substrate was cleaned using oxygen plasma for 5 minutes, and then the substrate was transferred to a vacuum evaporator.

The ITO transparent electrode thus prepared was thermally vacuum deposited to a thickness of 200 ANGSTROM to form a hole injection layer. Then, an anthracene-based MADN was vacuum deposited to a thickness of 300 A as a light emitting layer, and an Alq ₃ compound was vacuum deposited as an electron transport layer to a thickness of 300 ANGSTROM. Subsequently, Of lithium fluoride (LiF) and aluminum of 1000 Å thickness were deposited to form a negative electrode.

In the above process, the deposition rate of the organic material was maintained at 1 Å / sec, the deposition rate of lithium fluoride at 0.2 Å / sec, and the deposition rate of aluminum at 3 to 7 Å / sec.

Table 1 shows the electroluminescent characteristics of the organic electroluminescent device prepared above.

Example 1: ITO / CuPc / NPB / DSA-Cz / Alq 3 / LiF / Al

An OLED was prepared in the same manner as in Comparative Example 1, except that the DSA-Cz compound prepared in Synthesis Example 2 was used as a light emitting layer instead of using MADN.

Example 2: ITO / CuPc / NPB / DSA-flu / Alq 3 / LiF / Al

In Comparative Example 1, an OLED was fabricated in the same manner as in Comparative Example 1, except that the DSA-flu compound prepared in Synthesis Example 3 was used as a light emitting layer instead of using MADN.

Example 3: ITO / CuPc / NPB / DSA-spiro / Alq 3 / LiF / Al

An OLED was prepared in the same manner as in Comparative Example 1, except that the DSA-spiro compound prepared in Synthesis Example 4 was used as a light emitting layer instead of using MADN.

The characteristics of the organic electroluminescent device prepared in Comparative Example 1 and Examples 1 to 3 were evaluated and the results are shown in Table 1. [

Here, the unit of current density is mA / cm ² , the unit of color coordinate is CIE 1931 (x, y), the efficiency is calculated by using luminance and current density, the unit is cd / A, the lifetime is 200 nit, to be.

Current density
(mA / cm ² ) Color coordinates
(x, y) efficiency
(cd / A) life span
(hrs) Comparative Example 1 30 (0.18, 0.29) 3.12 9100 Example 1 30 (0.13, 0.15) 3.32 14300 Example 2 30 (0.13, 0.13) 3.53 13700 Example 3 30 (0.14, 0.13) 3.48 13800

As described in detail above, the OLED device using the aromatic compound derivative of the present invention has high luminous efficiency and lifetime, and blue luminescence is obtained. Therefore, it is highly industrially useful as an OLED having high practicality. The OLED of the present invention can be suitably used for a flat panel display, a planar illuminator, an illuminant of a surface-emitting OLED for illumination, a flexible illuminator, a light source such as a printer, an LCD backlight or a meter, a display plate,

Claims (13)

An aromatic compound derivative selected from the group of compounds represented by the following structural formulas:

.
The method according to claim 1,
The aromatic compound derivative may be applied to any one selected from the group consisting of an organic electroluminescent device (OLED), an organic solar cell (OSC), an electronic paper (e-paper), an organic photoconductor (OPC) Aromatic compound derivative.
And at least one layer of the organic material layer comprises the aromatic compound derivative according to the first aspect of the present invention. 2. The organic electroluminescent device according to claim 1, wherein the organic compound layer comprises a first electrode, a second electrode and at least one organic compound layer disposed between the first electrode, .
The method of claim 3,
Wherein the layer containing the aromatic compound derivative is a light emitting layer.
The method of claim 3,
Wherein the layer containing the aromatic compound derivative is a host.
The method of claim 3,
Wherein the layer containing the aromatic compound derivative is an electron layer.
The method of claim 3,
Wherein the layer containing the aromatic compound derivative is a hole layer.
8. The method according to any one of claims 4 to 7,
Wherein the organic material layer further comprises at least one or more selected from the group consisting of a hole injection layer, a hole transport layer, a hole blocking layer, and an electron transport layer. delete delete delete delete delete

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