KR100807202B1 - Trianthracene arylamine derivatives and organic light emitting layer or diode comprising the same - Google Patents

Abstract

An anthracene arylamine derivative is provided to inhibit crystallization caused by a planar structure of anthracene, thereby improving the lifespan, light emitting efficiency, heat resistance and driving voltage of a light emitting device. An anthracene aryl amine derivative is a compound selected from the compounds represented by the following formula 3 and formula 4. The anthracene arylamine derivative is used in an organic light emitting layer, particularly as a green dopant material, of an organic light emitting device.

Description

TRIANTHRACENE ARYLAMINE DERIVATIVES AND ORGANIC LIGHT EMITTING LAYER OR DIODE COMPRISING THE SAME

The present invention relates to a trianthracene arylamine compound of formula (1) or (2) in which one or two diarylamine groups are positioned at specific positions, and an organic electroluminescent layer or organic electroluminescent device comprising the same. Efficiency and low voltage driveability can be greatly improved.

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. The 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 mentioned.

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 (8-hydroquinoline aluminum salt) and a variety of green light emitting materials as a host, but the anthracene-based aromatic amine derivative compounds disclosed in the prior art, including the compound is 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 one or two diaryl groups at a specific position, a trianthracene arylamine derivative which can greatly increase the material life, luminous efficiency and low voltage driveability, and an organic compound including the same. The object is to provide an electroluminescent layer and an organic 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 trianthracene arylamine derivative, and more particularly to an anthracene arylamine derivative represented by the following formula (1).

In the above formula, Ar ₁ and Ar ₂ are the same as or different from each other, and each independently an aromatic ring group or aromatic ring amine group selected from benzene, naphthalene, biphenyl, anthracene, triphenylamine; R ¹ to R ²⁵ 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.

Another aspect of the invention relates to a trianthracene arylamine derivative represented by the following formula (2).

In the above formula, Ar ₃ to Ar ₆ are the same as or different from each other, and each independently an aromatic ring group or aromatic ring amine group selected from benzene, naphthalene, biphenyl, anthracene, triphenylamine; 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 the trianthracene, which is the main skeleton of the triantracene arylamine derivative according to the present invention, one or more diarylamino groups may be bonded at various positions. However, diarylamine groups in which the diarylamine groups are bonded to the positions represented by the compounds of Formulas 1 and 2, respectively, are bonded between carbon-nitrogen than those in the R ⁵ and R ¹⁷ positions. The more difficult the rotation and the greater the steric hindrance, the more likely the anthracenes to deviate from the plane, resulting in less intermolecular excimer formation or concentration quenching. The present invention is more meaningful in that it is remarkably superior in terms of 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, thiethyl, furyl, quinolyl and carbazolyl groups, but are not limited thereto.

According to a preferred embodiment, the present invention relates to an anthracene arylamine derivative selected from the group consisting of the following formulas (3) to (8).

Another aspect of the present invention relates to an organic electroluminescent layer comprising the triantracene arylamine 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 an anthracene arylamine derivative.

In the examples herein, only the synthesis examples and experimental examples of the trianthracene arylamine derivatives of the formulas (3) and (4) are described, but those skilled in the art to which the present disclosure pertains will be given based on the following descriptions and common sense in the art. It will be apparent that not only the trianthracene arylamine derivatives according to the present invention other than the formulas (3) and (4) can be easily synthesized, but a device including the same can be manufactured.

In addition, the present invention suppresses crystallization due to the planar three-dimensional structure of anthracene by using the compounds of the formulas (3) and (4) to increase device life and luminous efficiency and to improve the heat resistance of the organic EL device even at high temperatures. Is there. Therefore, although the examples of device life and luminous efficiency of all compounds according to the present invention are not described in the Examples herein, the device life of the compound of Formulas 4 to 6 is longer than that of conventional light emitting materials. It will be apparent to those skilled in the art that light emission efficiency will be improved in view 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 host include, but are not limited to, the two compounds shown in Table 1 below described in WO 2005/100506.

In the present invention, representative examples of the compound that can be used as a material having green light emitting ability include, but are not limited to, the compounds shown in Table 2 below.

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.

Preparation 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 Of formula 3  Preparation of the compound

As shown in Scheme 3 below, 2-bromotrianthracene (7.0 g, 11.5 mmol) and diphenylamine (2.5 g, 14.9 mmol) obtained in Preparation Example 2 were dissolved in toluene (250 mL), and then tris benzylidene Acetone di palladium (0.2 g, 0.03 mmol) was added under nitrogen. P ( t -Bu) ₃ (0.5 g, 2.3 mmol) was added to the reaction mixture, followed by NaOBu ^t (4.4 g, 45.9 mmol), and the reaction solution was stirred under reflux for 24 hours. After completion of the reaction, the thin silica gel pad was subjected to high temperature filtration to remove palladium. The filtrate was worked up using EA and water, and then the EA layer was dried over MgSO ₄ . The organic solvent layer was distilled under reduced pressure, the solvent was evaporated, and then filtered to obtain a brown solid product. The filtrate was dissolved in a small amount of methylene chloride and then the temperature was lowered and recrystallized to obtain a compound of formula 3 as a green solid (7.4 g, yield 92%).

¹ H NMR (CD ₂ Cl ₂ ) δ (ppm): 7.06-7.10 (m, 4H), 7.14-7.18 (m, 8H), 7.32-7.36 (m, 7H), 7.41-7.47 (m, 10H), 7.72 (s, 1 H), 7.94-7.98 (m, 10 H), 8.78-8.79 (d, J = 5.6 Hz, 2H); FD-MS: m / z 697 (M ⁺ ); Elemental analysis: calcd. For C ₅₄ H ₃₅ N: C 92.94%, H 5.06%, N 2.01%; found: C 93.08%, H 4.98%, N 1.94%.

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-butyl lithium 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%). .

Preparation Example 4 Preparation of 2,6-Dibromo Trianthracene

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 4  Preparation of the compound

As shown in Scheme 6, 2,6-dibromo trianthracene (2.9 g, 4.2 mmol) and diphenylamine (1.4 g, 8.5 mmol) obtained in Preparation Example 4 were dissolved in 70 mL of toluene, and then tris benzyl Lidine acetone di palladium (0.1 g, 0.1 mmol) was added under nitrogen. P ( t -Bu) ₃ (0.2 mL, 1.0 mmol) was added to the reaction mixture, NaOBu ^t (1.6 g, 16.9 mmol) was added thereto, and the reaction solution was stirred under reflux for 24 hours. After completion of the reaction, the thin silica gel pad was filtered hot to remove palladium, the filtrate was worked up with EA and water, and the EA layer was dried over MgSO ₄ . 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 give the compound of formula 4 as a green solid (2.9 g, yield 78%).

¹ H NMR (CD ₂ Cl ₂ ) δ (ppm): 7.16-7.21 (m, 10H), 7.44-7.50 (m, 14H), 7.72-7.77 (m, 8H), 8.28-8.32 (m, 10H), 8.83-8.84 (d, J = 5.0 Hz, 2H); FD-MS: m / z 864 (M ⁺ ); Elemental analysis: calcd. For C ₆₆ H ₄₄ N ₂ : C 91.64%, H 5.13%, N 3.24%; found: C 91.48%, H 5.21%, N 3.31%.

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 Formula 3 and Formula 4 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 332nm, 368nm, 388nm 503 nm 5.76 eV 2.82 eV 2.94 eV Inv-2 336nm, 370nm, 394nm 520 nm 5.78 eV 2.92eV 2.86 eV

Experimental Example 2: Evaluation of Device Characteristics of the Compound of Formula 3

Using the compound of Chemical Formula 3 prepared in Example 1 as a green dopant material, the device was configured as shown in Table 4, and the device properties were evaluated. The results are shown in Table 5 below.

HIL HTL EML ETL EIL Cathode Materials DS-205 DS-NPB Green Luminescent Host + Inv-1 Alq3 LiF Al Thickness 800 150 294 + 6 250 10 2,000 Evap. Temp. (℃) 360-370 250-260 Green Light Emitting Host: 250-260 Inv-1: 260-270 240-250

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 4.8 574 0.226, 0.478 495 5.7 3.8 25 5.5 1488 0.219, 0.476 494 6.0 3.4 50 6.3 3050 0.214, 0.474 494 6.1 3.0 100 7.1 6225 0.210, 0.472 495 6.2 2.8

Experimental Example 3: Evaluation of Device Characteristics of the Compound of Formula 4

Using the compound of Chemical Formula 4 prepared in Example 2 as a green dopant material, the device was evaluated as shown in Table 6 below, and the device characteristics thereof were evaluated. The results are shown in Table 7 below.

HIL HTL EML ETL EIL Cathode Materials DS-205 DS-NPB Green Luminescent Host + Inv-2 Alq3 LiF Al Thickness 800 150 294 + 6 250 10 2,000 Evap. Temp. (℃) 360-370 250-260 Green Light Emitting Host: 250-260 Inv-2: 260-270 240-250

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 4.8 576 0.236, 0.492 510 5.8 3.8 25 5.7 1485 0.234, 0.493 510 5.9 3.3 50 6.5 3040 0.229, 0.489 511 6.1 2.9 100 7.2 6212 0.230, 0.490 511 6.2 2.7

As described above, according to the present invention, the organic electroluminescent layer or the organic electroluminescent device by the trianthracene arylamine compound of the formula (1) or (2) having one or two diarylamine groups in a specific position has a device life and luminous efficiency. It can be seen that the low voltage driveability is greatly improved.

Claims (5)

delete delete Anthracene arylamine derivative selected from the group consisting of the compounds of formulas (3) to (4). [Formula 3]

[Formula 4]

An organic electroluminescent layer comprising an anthracene arylamine derivative according to claim 3. An organic electroluminescent device comprising an anthracene arylamine derivative according to claim 3.