KR20070101754A - Diaryl trianthracene derivatives and organic light emitting layer or diode comprising the same - Google Patents

Abstract

A diaryl trianthracene derivative, an organic light emitting layer prepared from the derivative, and an organic electroluminescent device containing the organic light emitting layer are provided to improve lifetime, luminous efficiency and low voltage operation. A diaryl trianthracene derivative is represented by the formula 1, wherein Ar1 and Ar2 are identical or different each other and are independently an aryl group or an aromatic group selected from benzene, naphthalene, biphenyl and anthracene; R1 to R24 are identical or different one another and are independently H, a halogen atom, a substituted or unsubstituted C1-C30 alkyl group, a substituted or unsubstituted C1-C30 alkenyl group, a substituted or unsubstituted C5-C30 aryl group, a substituted or unsubstituted C5-C30 arylalkyl group, a substituted or unsubstituted C5-C30 aryloxy group, a substituted or unsubstituted C5-C30 heteroaryl group, a substituted or unsubstituted C5-C10 cycloalkyl group, or a substituted or unsubstituted C5-C10 heterocycloalkyl group, or can form a fused ring between adjacent substituents.

Description

Diaryl triantracene derivatives, organic electroluminescent layer and organic electroluminescent device comprising same TECHNICAL FIELD

The present invention relates to a diaryl triantracene compound represented by Chemical Formula 1 having two aryl groups at a specific position, and an organic electroluminescent layer or organic electroluminescent device comprising the same, thereby greatly improving device life, luminous efficiency, and low voltage driveability. Can be.

The organic electroluminescent device (hereinafter 'EL') device is a self-luminous device using the principle that a fluorescent material emits light by recombination energy of holes injected from an anode and electrons injected from a cathode by applying a voltage.

As the device structure of the organic EL device, a two-layer type of a hole transport (injection) layer and an electron transport light emitting layer, or a three-layer type of a hole transport (injection) layer, a light emitting layer, and an electron transport (injection) layer is well known. In such a stacked structure device, a device structure or a formation method has been studied to increase recombination efficiency of injected holes and electrons. Advantages of the laminated structure include improving the injection efficiency of holes as the light emitting layer, blocking the electrons injected from the cathode to increase the generation efficiency of excitons generated by recombination, trapping excitons generated in the light emitting layer, and the like. Can be.

Since a low-voltage driving organic EL device by a stacked device has been reported by C. W. Tang et al. In 1987 by Eastman Kodak Corp., research on organic EL devices using organic materials as a constituent material has been actively conducted. Tang et al. Used Tris (8-hydroxyquinolinol aluminum) for the light emitting layer and triphenyldiamine derivative for the hole transport layer.

On the principle of the organic EL device, first, when a forward voltage is applied to the device, holes and electrons are injected from the anode and the cathode, respectively, and they are recombined in the light emitting layer to form an exciton, which is a pair of electron-holes. The exciton, which has a structure in which the pi-electron of the molecule is excited, returns to the ground state and converts the corresponding energy into light.

Recently, a method of doping a small amount of fluorescent dyes or phosphorescent dyes to the light emitting layer forming the exciton in order to increase the color purity and efficiency of the light emitted is known. The principle is that when a small amount of fluorescent or phosphorescent dyes (hereinafter abbreviated as 'dopants') are mixed in the light emitting layer with a smaller energy band gap than the molecules forming the light emitting layer, excitons generated in the light emitting layer are transferred to the dopant, thereby providing high efficiency light. It is a principle to pay.

Conventionally, 8-hydroquinoline aluminum salt and various green light emitting materials are used as hosts, but the anthracene-based aromatic amine derivative compounds disclosed in the prior art, including the compound, are crystallized. In order to solve the problem, the device life and luminous efficiency are still in need of improvement after prolonged use, and in particular, there is a great need to develop an electroluminescent material that can be driven at low voltage.

In order to solve the above problems, in the present invention, by introducing two aryl groups at a specific position, a diaryl triantracene derivative capable of greatly improving the material life, luminous efficiency and low voltage driveability, and an organic electroluminescent layer and the same including the same The object is to provide an electroluminescent device.

In fabricating an organic light emitting device having a multi-layered structure comprising a substrate and an organic material layer of different thin films containing at least one organic compound between the anode layer and the cathode layer, the novel materials presented can greatly improve the lifetime and efficiency of the device. Its purpose is to be used as a new light emitting material.

One aspect of the present invention relates to a diaryl trianthracene derivative, and more particularly, to a diaryl trianthracene derivative represented by the following Chemical Formula 1.

In the above formula, Ar ₁ and Ar ₂ are the same as or different from each other, and each independently an aryl group or an aromatic ring group selected from benzene, naphthalene, biphenyl, anthracene; R ₁ to R ₂₄ are the same as or different from each other, and each independently hydrogen, a halogen group, a substituted or unsubstituted alkyl group having 1 to 30 carbon atoms, a substituted or unsubstituted alkenyl group having 1 to 30 carbon atoms, a substituted or unsubstituted group An aryl group having 5 to 30 carbon atoms, a substituted or unsubstituted arylalkyl group having 5 to 30 carbon atoms, an aryloxy group having 5 to 30 carbon atoms substituted or unsubstituted, a heteroaryl having 5 to 30 carbon atoms substituted or unsubstituted An aryl group, a substituted or unsubstituted cycloalkyl group having 5 to 10 carbon atoms, a substituted or unsubstituted heterocycloalkyl group having 5 to 10 carbon atoms, or a condensed ring group may be formed between adjacent substituents.

In triantracene, which is the main skeleton of the diaryl triantracene derivative according to the present invention, aryl groups or aromatic ring groups Ar ₁ and Ar ₂ may be bonded to one or two or more positions at various positions. However, the case where Ar ₁ and Ar ₂ are bonded to the position represented by the compound of Formula 1, respectively, is more particularly when the aryl group is bonded to another position, especially when the aryl group is bonded to the R5 or / and R17 position. Rotation between carbon and carbon is more difficult, and because of the large steric hindrance, the anthracenes are more likely to have more out-of-plane structures, so there is less chance of intermolecular excimer formation or concentration quenching. The present invention is more meaningful in that it is remarkably excellent in terms of device life, luminous efficiency and low voltage driveability.

In the present invention, the alkyl group is a concept including all linear, branched and cyclic alkyl groups, and representative examples of the substituted or unsubstituted C1-30 alkyl group include methyl, ethyl, propyl, isopropyl, Butyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, heptyl group, octyl group and the like, but is not limited thereto.

In the present invention, representative examples of the substituted or unsubstituted alkenyl group having 1 to 30 carbon atoms may include diphenylethene, phenylnaphthylethene, dinaphthylethene, and the like, but are not limited thereto.

In the present invention, examples of the substituted or unsubstituted aryl group having 5 to 30 carbon atoms include phenyl group, 2-methylphenyl group, 3-methylphenyl group, 4-methylphenyl group, 4-ethylphenyl group, biphenyl group, and 4-methyl group. Biphenyl group, 4-ethylbiphenyl group, 4-cyclohexylbiphenyl group, terphenyl group, 3,5-dichlorophenyl group, naphthyl group, 5-methylnaphthyl group, anthryl group, pyrenyl group and the like, but are not limited thereto Do not.

Representative examples of the substituted or unsubstituted arylalkyl group having 5 to 30 carbon atoms include benzyl, α-methylbenzyl, α-ethylbenzyl, α, α-dimethylbenzyl, 4-methylbenzyl and 4-ethylbenzyl. Groups, 2-tert-butylbenzyl group, 4-n-octylbenzyl group, naphthylmethyl group, diphenylmethyl group and the like, but are not limited thereto.

In the present invention, representative examples of the aryloxyl group include phenoxyl group, naphthyloxyl group, anthryloxyl group, pyrenyloxyl group, fluoranthhenyloxyl group, chrysenyloxyl group and peryleneyloxyl group, and the like. It is not limited.

In the present invention, a representative example of the substituted or unsubstituted heteroaryl group having 5 to 30 carbon atoms may include pyridine, quinoline, isoquinoline, phenylisoquinoline, and the like, but is not limited thereto.

In the present invention, a representative example of the substituted or unsubstituted cycloalkyl group having 5 to 10 carbon atoms may include cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, norbornel group, adamantyl group, etc. It is not limited to this.

In the present invention, representative examples of the substituted or unsubstituted heterocycloalkyl group having 5 to 10 carbon atoms may include pyridyl group, thiethyl group, furyl group, quinolyl group, carbazolyl group, and the like, but are not limited thereto. Do not.

In the present invention, representative examples of the functional group which can be substituted include halogen atoms such as fluorine atom, chlorine atom, bromine atom and iodine atom; Alkyl groups such as methyl group, ethyl group, n-propyl group and isopropyl group; Alkoxyl groups such as methoxyl group and ethoxyl group; Aryloxy groups such as phenoxyl groups; Arylalkyl groups such as benzyl group, phenethyl group and phenylpropyl group; Nitro group; Cyano group; Substituted amino groups such as dimethylamino group, dibenzylamino group, diphenylamino group, and porolino group; Aryl groups such as phenyl, tolyl, biphenyl, naphthyl, anthryl and pyrenyl groups; And heterocycle groups such as pyridyl group, thiethyl group, furyl group, quinolyl group, and carbazolyl group, and the like, but are not limited thereto.

According to a preferred embodiment, the present invention relates to a diaryl trianthracene derivative selected from the group consisting of the following formulas (2) to (5).

Another aspect of the present invention relates to an organic electroluminescent layer comprising the diaryl triantracene derivative according to the present invention described above, and according to another aspect of the present invention relates to an organic EL device comprising such a diaryl triantracene derivative. .

In the examples herein, only the synthesis examples and experimental examples of the diaryl triantracene derivatives of the formulas (2) and (3) are described, but those skilled in the art to which the present disclosure pertains will be given based on the description of the following examples and common sense in the art. It will be apparent that not only the diaryl trianthracene derivatives according to the present invention other than the formulas (2) and (3) can be easily synthesized, but devices can be manufactured including the same.

In addition, the present invention is characterized by the use of the compound of the formula (1) to suppress the crystallization caused by the planar three-dimensional structure of the anthracene to increase device life and luminous efficiency and to improve the heat resistance of the organic EL device at high temperatures. Therefore, although the examples of device life and luminous efficiency for all the compounds according to the present invention are not described in the Examples herein, as long as the compound of Formula 1 is used, the device life and luminous efficiency compared to conventional light emitting materials This improvement will be apparent to those skilled in the art in light of the results of the following experimental examples.

In the present invention, representative examples of the compound that can be used as the hole injection layer material include, but are not limited to, DS-205 developed by the company.

In the present invention, representative examples of the compound that can be used as a material for forming the hole transport layer include N, N'-diphenyl-NN-bis (1-naphthyl) -1,1'- as shown in Table 1 below. Biphenyl-4,4'-diamine compounds, including but not limited to.

In the present invention, representative examples of the compound that can be used as the electron transporting layer forming material material include, but are not limited to, the 8-hydroquinoline aluminum salt compound described in Table 1.

In the present invention, representative examples of the compound that can be used as the green light emitting dopant and the blue light emitting dopant include the compounds shown in Table 1 described in US Patent Application Publication No. 2005/0260442 and EP 1314715, respectively. However, it is not limited thereto.

Hole transport layer

Electron transport layer

Green luminous dopant

Blue emitting dopant

Example

Hereinafter, the content of the present invention will be described in detail through examples. However, the following examples are provided to explain the contents of the present invention and do not limit the scope of the present invention.

Production Example  1: Preparation of Compound a

As shown in Scheme 1 below, 9-bromoanthracene (29.6 g, 114.9 mmol) was dissolved in purified THF (250 mL) under nitrogen atmosphere, cooled to -78 ° C, and then n-butyllithium hexane solution (82 mL). , 1.6 M)) was added slowly. After stirring for 1 hour at the same temperature, 2-bromo anthraquinone (15.0 g, 41.0 mmol) was added at the same temperature. After removing the cooling vessel, the reaction was stirred at room temperature for 5 hours. After removing the reaction solution, the solvent was removed by extraction with water and dichloromethane. After sufficiently washing with n-hexane, it was dried in vacuo to give Compound a as a light brown solid (30.5 g, 91% yield).

Production Example  2: 2- Bromotrianthracene  Produce

As shown in Scheme 2, a mixture of Chemicals a (20.0 g, 31.9 mmol) and potassium iodine (51.6 g, 310.8 mmol) and sodium hypophosphite hydrate (45.1 g, 512.8 mmol) obtained in Preparation Example 1 was prepared. Reflux in acetic acid (500 mL) solution for 3 h. After cooling to room temperature, the solids were filtered, washed several times with water and methanol and dried to obtain 2-bromotrianthracene, a pale yellow solid (15.0 g, 79% yield).

Example  1: according to the invention Formula 2  Preparation of the compound

As shown in Scheme 3 below, 2-bromo trianthracene (7.0 g, 11.5 mmol) and 2-naphthalene boronic acid (4.7 g, 18.4 mmol) obtained in Preparation Example 2 were dissolved in toluene (150 mL). Tetrakistriphenylphosphino palladium (0.3 g, 0.2 mmol) was added under nitrogen. Sodium carbonate (3.7 g, 34.5 mmol) was dissolved in distilled water (100 mL), and then the reaction solution was stirred under reflux for 5 hours. After completion of the reaction, the mixture was extracted using methylene chloride and water, and a thin silica gel pad was subjected to high temperature filtration to remove palladium. The organic solvent layer was distilled under reduced pressure, and the solvent was evaporated, followed by filtration to obtain a brown solid product. The filtrate was dissolved in a small amount of methylene chloride and then cooled down to recrystallize and filtered to yield a compound of formula (2) as a pale yellow solid (6.7 g, 89% yield).

¹ H NMR (CD ₂ Cl ₂ ) δ (ppm): 7.11-7.13 (m, 2H), 7.15-7.16 (m, 1H), 7.18-7.22 (m, 2H), 7.34-7.38 (m, 7H), 7.41-7.45 (m, 4H), 7.53-7.58 (m, 6H), 7.62-7.68 (m, 4H), 8.26-8.29 (t, J = 7.7 ㎐, 4H), 8.82-8.83 (d, J = 5.8 Iii, 2H); FD-MS: m / z 656 (M ⁺ ); Elemental analysis: calcd. For C ₅₂ H ₃₂ : C 95.09%, H 4.91%; found: C 95.28%, H 4.71%.

Production Example  3: Preparation of Compound b

As shown in Scheme 4 below, 9-bromoanthracene (14.8 g, 57.4 mmol) was dissolved in purified THF (350 mL) under nitrogen atmosphere, cooled to -78 ° C, and then n-butyllithium hexane solution (42.7 mL). , 1.6 M) was added slowly. After stirring for 1 hour at the same temperature, 2,6-dibromoanthraquinone (10.0 g, 27.3 mmol) was added at the same temperature. After removing the cooling vessel, the reaction was stirred at room temperature for 5 hours. After the reaction solution was removed, the mixture was extracted with water and dichloromethane to remove the solvent, and then sufficiently washed with n-hexane, and the material was dried in vacuo to give the compound b as a light brown solid (9.2 g, yield 49%). .

Production Example  4: 2,6- Dibromo Triantracene  Produce

As shown in Scheme 5, a mixture of the chemical b (18.5 g, 25.6 mmol) obtained in Preparation Example 3, potassium iodine (42.5 g, 256.1 mmol), and sodium hypophosphite hydrate (37.2 g, 422.5 mmol) was prepared. Reflux in acetic acid (500 mL) solution for 3 h. After cooling to room temperature, the solids were filtered and washed several times with water and methanol, and the material was dried to give 2,6-dibromo trianthracene as a brown solid (10.0 g, yield 57%).

Example  2: according to the invention Of formula 3  Preparation of the compound

As shown in Scheme 6, 2,6-dibromotrianthracene (8.0 g, 11.6 mmol) and 2-naphthaleneboronic acid (7.4 g, 29.0 mmol) obtained in Preparation Example 4 were toluene (200 mL). After dissolving in tetrakistriphenylphosphinopalladium (0.7 g, 0.6 mmol) was added under nitrogen. Sodium carbonate (15.4 g, 145.0 mmol) was dissolved in distilled water (150 mL), and then the reaction solution was stirred under reflux for 5 hours. After completion of the reaction, the mixture was extracted using methylene chloride and water, and a thin silica gel pad was subjected to high temperature filtration to remove palladium. The organic solvent layer was distilled under reduced pressure, and the solvent was evaporated, followed by filtration to obtain a brown solid product. The filtrate was dissolved in a small amount of methylene chloride and then cooled to recrystallization and filtered to give a compound of formula 3 as a yellow solid (8.1 g, yield 87%).

¹ H NMR (CD ₂ Cl ₂ ) δ (ppm): 7.12-7.16 (m, 8H), 7.31-7.35 (m, 8H), 7.40-7.42 (m, 2H), 7.55-7.62 (m, 14H), 8.31-8.35 (m, 4H), 8.72-8.76 (d, J = 5.2 Hz, 2H); FD-MS: m / z 782 (M ⁺ ); Elemental analysis: calcd. For C ₅₂ H ₃₈ : C 95.11%, H 4.89%; found: C 95.31%, H 4.67%.

Experimental Example  1: Evaluation of Optical Properties

The optical properties such as UV absorbance, polarization (PL) absorbance, energy level, and bandgap were evaluated for the compounds of Formulas 2 and 3 prepared in Examples 1 and 2, respectively, and the results are shown in Table 3 below. Indicated.

UV (abs.) PL (λmax) HOMO LUMO Eg Inv-1 316 nm, 366 nm 440 nm 5.90 eV 2.76 eV 3.14 eV Inv-2 320 nm, 368 nm 446 nm 5.92 eV 2.83 eV 3.09 eV

Experimental Example  2: Formula 2  Evaluation of Device Characteristics for Compounds (1)

Using the compound of Chemical Formula 2 prepared in Example 1 as a green host material and using a green dopant as shown in Table 4, the device characteristics were evaluated, and the results are shown in Table 5 below.

HIL HTL EML ETL EIL Cathode Materials DS-205 DS-NPB Inv-1 + Green Light Emitting Pants Alq3 LiF Al Thickness 800 150 294 + 6 250 10 2,000 Evap. Temp. (℃) 350-360 220-250 Inv-1: 330-340 Green Light Emitting Pants: 230-240 240-250

Current Density (mA / cm ² ) Voltage (V) Luminance (cd / m ² ) CIE index (x, y) Peak λ (nm) Efficiency (cd / A) Efficiency (Im / W) 10 5.5 1552 0.286, 0.637 520 15.5 8.9 25 6.3 4120 0.285, 0.635 519 16.5 8.2 50 7 8273 0.283, 0.633 519 16.5 7.4 100 7.8 16780 0.281, 0.631 519 16.8 6.8

Experimental Example  3: Formula 2  Evaluation of Device Characteristics for Compounds (2)

Using the compound of Chemical Formula 2 prepared in Example 1 as a blue host material and using a blue dopant as shown in Table 6, the device characteristics were evaluated, and the results are shown in Table 7 below.

HIL HTL EML ETL EIL Cathode Materials DS-205 DS-NPB Inv-1 + Blue Light Emitting Pants Alq3 LiF Al Thickness 800 150 285 + 15 250 10 2,000 Evap. Temp. (℃) 350-360 220-230 Inv-1: 330-340 Blue Light Emitting Pants: 250-260 240-250

Current Density (mA / cm ² ) Voltage (V) Luminance (cd / m ² ) CIE index (x, y) Peak λ (nm) Efficiency (cd / A) Efficiency (Im / W) 10 4.6 742 0.354, 0.482 550 7.4 5.1 25 5.4 1854 0.354, 0.478 550 7.4 4.3 50 6 3603 0.353, 0.474 550 7.2 3.8 100 6.7 6853 0.352, 0.468 550 6.9 3.2

Experimental Example  4: Of formula 3  Evaluation of Device Characteristics for Compounds (1)

Using the compound of Chemical Formula 3 prepared in Example 2 as a green host material and using a green dopant as shown in Table 8, the device characteristics were evaluated, and the results are shown in Table 9 below.

HIL HTL EML ETL EIL Cathode Materials DS-205 DS-NPB Inv-2 + Green Light Emitting Pants Alq3 LiF Al Thickness 800 150 294 + 6 250 10 2,000 Evap. Temp. (℃) 350-360 220-250 Inv-2: 330-340 Green Light Emitting Pants: 230-240 240-250

Current Density (mA / cm ² ) Voltage (V) Luminance (cd / m ² ) CIE index (x, y) Peak λ (nm) Efficiency (cd / A) Efficiency (Im / W) 10 5.4 1435 0.280, 0.641 519 14.4 8.3 25 6.2 3528 0.279, 0.639 519 14.1 7.1 50 7 7005 0.278, 0.637 519 14.0 6.3 100 7.7 13920 0.276, 0.635 519 13.9 5.7

Experimental Example  4: Of formula 3  Evaluation of Device Characteristics for Compounds (2)

Using the compound of Chemical Formula 3 prepared in Example 2 as a blue host material and using a blue dopant as shown in Table 10, the device characteristics were evaluated, and the results are shown in Table 11 below.

HIL HTL EML ETL EIL Cathode Materials DS-205 DS-NPB Inv-2 + Blue Light Emitting Pants Alq3 LiF Al Thickness 800 150 285 + 15 250 10 2,000 Evap. Temp. (℃) 350-360 220-230 Inv-2: 330-340 Blue Light Emitting Pants: 250-260 240-250

Current Density (mA / cm ² ) Voltage (V) Luminance (cd / m ² ) CIE index (x, y) Peak λ (nm) Efficiency (cd / A) Efficiency (Im / W) 10 4.6 714 0.356, 0.485 550 7.1 4.9 25 5.4 1876 0.356, 0.480 550 7.5 4.4 50 6 3649 0.355, 0.476 550 7.3 3.8 100 6.8 6946 0.354, 0.470 550 6.9 3.2

As described above, according to the present invention, the organic electroluminescent layer or the organic electroluminescent device by the diaryl triantracene compound represented by Formula 1 having two aryl groups at specific positions is greatly improved in device life, luminous efficiency and low voltage driveability. You can check it.

Claims (4)

Diaryl triantracene derivative represented by the following formula (1): [Formula 1]

In the above formula, Ar ₁ and Ar ₂ are the same as or different from each other, and each independently an aryl group or an aromatic ring group selected from benzene, naphthalene, biphenyl, anthracene; R ₁ to R ₂₄ are the same as or different from each other, and each independently hydrogen, a halogen group, a substituted or unsubstituted alkyl group having 1 to 30 carbon atoms, a substituted or unsubstituted alkenyl group having 1 to 30 carbon atoms, a substituted or unsubstituted group An aryl group having 5 to 30 carbon atoms, a substituted or unsubstituted arylalkyl group having 5 to 30 carbon atoms, an aryloxy group having 5 to 30 carbon atoms substituted or unsubstituted, a heteroaryl having 5 to 30 carbon atoms substituted or unsubstituted An aryl group, a substituted or unsubstituted cycloalkyl group having 5 to 10 carbon atoms, a substituted or unsubstituted heterocycloalkyl group having 5 to 10 carbon atoms, or a condensed ring group may be formed between adjacent substituents. The following relates to a diaryl triantracene derivative selected from the group consisting of the following compounds: [Formula 2]

[Formula 3]

[Formula 4]

[Formula 5]

An organic electroluminescent layer comprising the diaryl triantracene derivative according to claim 1. An organic electroluminescent device comprising the diaryl triantracene derivative according to claim 1.