KR101508145B1 - Organic electroluminescent compound, producing method of the same and organic electroluminescent device including the same - Google Patents

Abstract

The present invention relates to a novel organic light emitting compound, a method for producing the organic light emitting compound, and an organic electroluminescent device including the organic light emitting compound.

Description

TECHNICAL FIELD The present invention relates to an organic electroluminescent compound, an organic electroluminescent compound, a method for producing the same, and an organic electroluminescent device including the electroluminescent compound.

The present invention relates to a novel organic light emitting compound, a method for producing the organic light emitting compound, and an organic electroluminescent device including the organic light emitting compound.

The importance of display, which acts as an interface between electronic information devices and human beings, is rapidly increasing as they rapidly enter the information age. Especially, it is urgently needed to develop a display that can be used conveniently anytime and anywhere, and can display a realistic and vivid screen. Furthermore, studies have been made actively to develop a thinner, lighter, and more flexible display that is flexible and thinner than a glass substrate instead of a glass substrate (Korean Patent Laid-Open Publication No. 10-2012-0116837 number]. Organic light emitting diode (OLED) displays are attracting much attention as next generation flat panel display technology which is best suited for such applications. The electroluminescence phenomenon in organic semiconductors was first found in anthracene crystals by Pope, Kallmann, Magnate in 1963 [M. Pope, HP Kallmamm and P. Magnae, J. Chem. Phys. 38, 2042 (1963)], followed in 1965 by W. Helfrich [W. Helfrich and WG Schneider, Phys. Rev. Lett. 14, 229 (1965)]. However, high-purity anthracene crystals have an electrical conductivity of 10 s / cm or less, so the efficiency of light emission is very low because electrons and holes are injected by applying a voltage higher than several hundreds of volts. In addition, there has been a serious problem in terms of practical use of an alkali metal having high reactivity as an electrode. In 1982, Vincett et al. Succeeded in forming an amorphous anthracene thin film by vacuum evaporation method and fabricating an organic light emitting diode. The luminous efficiency of this device was very low at about 0.05%, but this method has been used as a typical OLED manufacturing method to date. In 1987, Tang et al. Of Kodak developed a low-molecular-weight OLED display rapidly after discovering a green luminescence phenomenon with improved efficiency and stability by forming a bilayer low-molecular organic thin film of Alq ₃ and TPD as a light emitting layer and a charge transport layer, respectively lost. In such a device structure, electrons and holes are accumulated on the diamine / Alq ₃ interface due to the difference in electron energy level between the hole transporting material and the electron transporting material, thereby increasing the probability of electron-hole re-defect. As a result, the device exhibited a luminance of more than 1000 cd / m 2 at a driving voltage of 10 V or less and a high luminous efficiency of 1.5 lm / W. This result has played a major role in activating OLED research around the world because of its potential to develop high brightness and high efficiency displays using organic thin film light emitting diodes. In the late 1980s, the structure of a low-molecular OLED device started from a simple structure of an anode (ITO), a hole transport layer (HTL), an emission layer (EML), and a cathode (Mg: Ag). Then, a hole injection layer (HIL) such as CuPc was introduced in the case of a fluorescent device, and Al: Li was developed as a cathode and an electron injection layer material, and a material such as LiF was developed, . As a result, the efficiency and driving voltage of the electro-optical device have been improved.

Nonetheless, there is a continuing need to develop more stable and efficient materials that can be used in organic electroluminescent devices to further improve the properties of the organic electroluminescent devices.

The present invention provides a novel organic light emitting compound, a method for producing the organic light emitting compound, and an organic electroluminescent device including the organic light emitting compound.

However, the problems to be solved by the present invention are not limited to the problems described above, and other problems not described can be clearly understood by those skilled in the art from the following description.

A first aspect of the invention provides an organic electroluminescent compound represented by Formula 1:

[Chemical Formula 1]

In Formula 1,

R ₁ is H; An indole group, a carbazole group, a diphenylamine group or a triphenylamine group; A 5-membered unsaturated or aromatic ring which may be substituted, a 6-membered unsaturated or aromatic ring which may be substituted, a 5-membered unsaturated or aromatic heterocyclic ring which may be substituted and a 6-membered unsaturated or aromatic heterocyclic ring which may be substituted Or a polycyclic ring fused with two or more rings selected from the above group.

The second aspect of the invention is a process for the preparation of an anthracene derivative of the formula I by reacting a derivative of the anthracene compound with either methylmagnesium chloride and methanesulphonic acid sequentially or by reacting a derivative of the anthracene compound with a naphthalene, phenylanthracene, indole, carbazole, diphenylamine With a triphenylamine derivative represented by the following formula (1): " (1) "

[Chemical Formula 1]

In Formula 1,

R ₁ is H; A naphthalene group, a phenylanthracenyl group, an indole group, a carbazole group, a diphenylamine group or a triphenylamine group; A 5-membered unsaturated or aromatic ring which may be substituted, a 6-membered unsaturated or aromatic ring which may be substituted, a 5-membered unsaturated or aromatic heterocyclic ring which may be substituted and a 6-membered unsaturated or aromatic heterocyclic ring which may be substituted Or a polycyclic ring fused with two or more rings selected from the above group.

The third aspect of the present invention provides an organic electroluminescent device comprising the organic electroluminescent compound according to the first aspect and the second aspect of the present invention.

The present invention can provide novel organic electroluminescent compounds exhibiting high electroluminescence (EL) performance with high luminous efficiency, high emission luminance, high color purity and significantly improved emission lifetime. Further, by applying the organic luminescent compound of the present invention to an organic electroluminescent device, an organic photonic device for photovoltaic power generation, etc., it is possible to lower the driving voltage and improve the luminous efficiency, luminance, color purity, thermal stability and lifetime.

1 is a schematic view of an organic electroluminescent device according to an embodiment of the present invention.
FIG. 2 is a graph showing electroluminescence characteristics of a device including an organic light emitting compound according to an embodiment of the present invention. Referring to FIG.
FIG. 3 is a graph showing current density and voltage characteristics of a device including an organic light emitting compound according to an embodiment of the present invention.
FIG. 4 is a graph illustrating the luminance and voltage characteristics of an organic light-emitting compound-containing device according to an embodiment of the present invention.
5 is a graph showing current density and luminous efficiency characteristics of a device including an organic light emitting compound according to an embodiment of the present invention
FIG. 6 is a graph showing current density and power efficiency characteristics of a device including an organic light emitting compound according to an embodiment of the present invention. Referring to FIG.
7 is a graph showing current density and quantum efficiency characteristics of a device including an organic light emitting compound according to an embodiment of the present invention.

Hereinafter, embodiments and examples of the present invention will be described in detail with reference to the accompanying drawings, which will be readily apparent to those skilled in the art to which the present invention pertains.

It should be understood, however, that the present invention may be embodied in many different forms and is not limited to the embodiments and examples described herein. In order to clearly illustrate the present invention, parts not related to the description are omitted, and similar parts are denoted by like reference characters throughout the specification.

Throughout this specification, when a member is "on " another member, it includes not only when the member is in contact with the other member, but also when there is another member between the two members.

Throughout this specification, when an element is referred to as "including " an element, it is understood that the element may include other elements as well, without departing from the other elements unless specifically stated otherwise. The terms "about "," substantially ", etc. used to the extent that they are used throughout the specification are intended to be taken to mean the approximation of the manufacturing and material tolerances inherent in the stated sense, Accurate or absolute numbers are used to help prevent unauthorized exploitation by unauthorized intruders of the referenced disclosure. The word " step (or step) "or" step "used to the extent that it is used throughout the specification does not mean" step for.

Throughout this specification, the term "combination thereof" included in the expression of the machine form means one or more combinations or combinations selected from the group consisting of the constituents described in the expression of the machine form, And the like.

Throughout this specification, the description of "A and / or B" means "A or B, or A and B".

Throughout this specification, the term "aromatic ring" refers to a C _{5 -30} aromatic hydrocarbon ring group such as phenyl, naphthyl, biphenyl, terphenyl, fluorene, phenanthrenyl, triphenylenyl, perylenyl Means an aromatic ring such as benzyl, benzyl, benzyl, benzyl, benzyl, benzyl, benzyl, benzyl, benzyl, benzyl, As the aromatic ring containing a hetero element, for example, pyrrolyl, pyrazinyl, pyridinyl, indolyl, isoindolyl, furyl, benzofuranyl, isobenzofuranyl, dibenzofuranyl, dibenzothiophenyl, Thienyl, and pyridine rings, pyrazine rings, pyrimidine rings, pyridazine rings, triazine rings, pyrrolidinyl rings, pyrrolidinyl rings, pyrrolidinyl rings, An indole ring, a quinoline ring, an acridine ring , Pyrrolidine ring, dioxane ring, piperidine ring, morpholine ring, piperazine ring, carbazole ring, furan ring, thiophene ring, oxazole ring, oxadiazole ring, benzoxazole ring, thiazole Means an aromatic heterocyclic group formed from a ring, thiadiazole ring, benzothiazole ring, triazole ring, imidazole ring, benzimidazole ring, pyran ring, dibenzofuran ring.

Throughout this specification, the term " fused " means that, with respect to two or more rings, at least one or more adjacent atoms are included in both rings.

A first aspect of the invention provides an organic electroluminescent compound represented by Formula 1:

[Chemical Formula 1]

In Formula 1,

R ₁ is H; An indole group, a carbazole group, a diphenylamine group or a triphenylamine group; A 5-membered unsaturated or aromatic ring which may be substituted, a 6-membered unsaturated or aromatic ring which may be substituted, a 5-membered unsaturated or aromatic heterocyclic ring which may be substituted and a 6-membered unsaturated or aromatic heterocyclic ring which may be substituted , Or a polycyclic ring fused with two or more rings selected from the above group.

In one embodiment herein, R < ₁ > may be selected from, but not limited to, the following substituents:

;

;

;

;

;

;

In this substituent,

R ₂ may be H, a cyan group, a methyl group, or a butyl group, but may not be limited thereto.

In one embodiment of the present invention, the organic light emitting compound may be, but not limited to, a compound represented by any one of the following formulas (2) to (9)

(2)

(3)

;

[Chemical Formula 4]

;

[Chemical Formula 5]

;

[Chemical Formula 6]

;

(7)

;

[Chemical Formula 8]

;

[Chemical Formula 9]

.

The second aspect of the invention is a process for the preparation of an anthracene derivative of the formula I by reacting a derivative of the anthracene compound with either methylmagnesium chloride and methanesulphonic acid sequentially or by reacting a derivative of the anthracene compound with a naphthalene, phenylanthracene, indole, carbazole, diphenylamine With a triphenylamine derivative to produce an organic light emitting compound represented by the following formula (1): < EMI ID =

[Chemical Formula 1]

;

In Formula 1,

R ₁ is H; A naphthalene group, a phenylanthracenyl group, an indole group, a carbazole group, a diphenylamine group or a triphenylamine group; A 5-membered unsaturated or aromatic ring which may be substituted, a 6-membered unsaturated or aromatic ring which may be substituted, a 5-membered unsaturated or aromatic heterocyclic ring which may be substituted and a 6-membered unsaturated or aromatic heterocyclic ring which may be substituted , Or a polycyclic ring fused with two or more rings selected from the above group.

In one embodiment of the present invention, the derivative of the anthracene compound may include, but is not limited to, a compound represented by Formula 10 or 11:

[Chemical formula 10]

;

(11)

;

In the above formulas,

R ₃ may be, but is not limited to, halogen.

In one embodiment of the present invention, exemplary reaction schemes for the method of preparing the organic light emitting compound may include, but are not limited to,

The third aspect of the present invention provides an organic electroluminescent device comprising the organic electroluminescent compound according to the present invention. The organic light emitting compound according to the present invention may be applied to all of the first and second aspects of the present invention, but the present invention is not limited thereto.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the scope of the present invention is not limited by these Examples.

[Example]

Except as noted, all other solvents were dried using standard procedures and all reactants were used as supplied.

Example 1

1.4 g of methyl 2- (10-phenyl-9-anthracenyl) benzoate was placed in a reaction vessel, dried under vacuum, and then filled with nitrogen gas. 20 mL of THF was added, and 3.6 mL of methylmagnesium chloride (3.0 M) was slowly added dropwise. The reaction solution was extracted with ethyl acetate and dried. The reaction mixture was put into a flask, and the compound was completely dissolved with a small amount of dichloromethane. Then, 2 mL of methanesulfonic acid was added, and the mixture was stirred at room temperature. After completion of the reaction, the reaction mixture was quenched with distilled water, extracted with dichloromethane, dried over magnesium sulfate, filtered through celite, and the solvent was evaporated. Thereafter, the resulting compound was subjected to column chromatography to obtain a final compound 1.

Dimethyl -9- phenyl - (5 H -naphth [3,2,1- de] anthracene) (1): ( yield ^{= 86%), 1 H-} NMR: 8.82 (d, 1H), 7.93 (d, 1H ), 7.74 (dd, 2H), 7.52 (m, 9H), 7.35 (m, 4H), 1.74 (s, 6H). APCI-MS (m / z): 370 [M ^< ⁺ &^gt;].

Example 2

3-bromo-5,5-dimethyl-9-phenyl - [5 H - naphth [3,2,1- de] anthracene] 1.36 g and the aromatic acid 0.54 g, tetrakis (triphenylphosphine) palladium ( 0) was placed in a reaction vessel of 140 mg, vacuum dried, and filled with nitrogen gas. 9 ml of toluene was added to the flask to dissolve the compounds, 4.5 ml of ethanol and 4.5 ml of 2.0 M sodium carbonate aqueous solution were added, and the mixture was refluxed for 3 hours at 120 ° C and stirred. After completion of the reaction, the reaction mixture was washed with distilled water and the organic layer was extracted with ethyl acetate. Dried over magnesium sulfate, filtered through celite, and then subjected to column chromatography to obtain final compounds 2 and 3.

5,5- Dimethyl -3- (2- naphthyl) -9- phenyl - (5 H -naphth [3,2,1- de] anthracene) (2): ( yield ^{= 73%), 1 H-} NMR: (M, 2H), 1.78 (d, IH), 8.21 (d, IH), 8.08 (s, 6 H). APCI-MS (m / z): 496 [M ^< ⁺ &^gt;].

5,5-Dimethyl-3- (10- phenylanthracen-9-yl) -9-phenyl- [5 H -naphth [3,2,1- de] anthracene] (3): ( yield = 57%), ¹ (M, 3H), 7.54 (m, 14H), 7.40 (m, 6H), 1.78 (s, 1H) 6H). APCI-MS (m / z): 622 [M ^< ⁺ &^gt;].

Example 3

To a mixture of 0.7 g of 3-bromo-5,5-dimethyl-9-phenyl- [5H-naphtho [3,2,1-de] anthracene], 0.27 g of indole, 0.34 g of carbazole or 0.27 g of diphenylamine, 0.07 g of kiss (triphenylphosphine) palladium (0), 0.06 g of dicyclohexylphosphino-2,4,6-triisopropylbiphenyl or 0.84 mL of tri- tert -butylphosphine and 0.45 mL of sodium tert -butoxide 0.45 g was placed in a reaction vessel, vacuum dried, and then filled with nitrogen gas. Toluene was added to the flask to dissolve the compounds, followed by refluxing and stirring at 100 DEG C for 3 hours. After completion of the reaction, the reaction mixture was washed with distilled water and the organic layer was extracted with toluene. Dried over magnesium sulfate, filtered through celite and column chromatography to give final compounds 4, 5, 6 and 7.

1- (5,5-Dimethyl-9- phenyl- [5 H -naphth [3,2,1- de] anthracen-3-yl]) - 1 H -Indole (4): ( yield = 79%), ^{1 H-NMR: 8.86 (d} , 1H), 8.22 (d, 1H), 7.90 (s, 1H), 7.72 (m, 3H), 7.62 (m, 2H), 7.54 (m, 5H), 7.47 (m , 7.35 (m, 3H), 7.21 (m, IH), 6.75 (d, IH), 1.78 (s, 6H). APCI-MS (m / z): 485 [M ^< ⁺ &^gt;].

9- (5,5-Dimethyl-9- phenyl- [5 H -naphth [3,2,1- de] anthracen-3-yl]) - 9 H -carbazole (5): ( yield = 53%), ^{1 H-NMR: 8.92 (d} , 1H), 8.31 (d, 1H), 8.19 (d, 2H), 7.96 (d, 1H), 7.73 (m, 2H), 7.63 (m, 2H), 7.56 (m , 6H), 7.47 (t, 4H), 7.39 (m, 2H), 7.33 (t, 2H), 1.78 (s, 6H). APCI-MS (m / z): 535 [M ^< ⁺ &^gt;].

N, N -Diphenyl- (5,5-dimethyl -9-phenyl- [5 H -naphth [3,2,1- de] anthracen-3-yl]) - amine (6): ( yield = 50%) ^{, 1 H-NMR: 8.79 (} d, 1H), 7.93 (d, 1H), 7.69 (dd, 1H), 7.57 (m, 4H), 7.46 (m, 4H), 7.32 (m, 6H), 7.22 ( dd, 4H), 7.06 (t, 2H), 7.01 (dd, 1H), 1.56 (s, 6H). APCI-MS (m / z): 537 [M ^< ⁺ &^gt;].

4- (N - (5,5- Dimethyl -9- phenyl - [5 H - naphth [3,2,1- de] anthracen-3- yl]) - N -phenylamino) benzonitirle (7): ( yield = ^{68%), 1 H-NMR} : 8.78 (d, 1H), 8.02 (d, 1H), 7.72 (d, 2H), 7.57 (m, 4H), 7.48 (m, 8H), 7.36 (dt, 2H) , 7.22 (d, 2H), 7.09 (m, 3H), 1.63 (m, 6H). APCI-MS (m / z): 562 [M ^< ⁺ &^gt;].

Example 4

0.6 g of 3-bromo-5,5-dimethyl-9-phenyl- [5H-naphtho [3,2,1-de] anthracene], 0.54 g of triphenylamine borate ester, 0.06 g of palladium (0) was placed in a reaction vessel, vacuum dried, and then filled with nitrogen gas. 12 mL of toluene was added to the upper flask to dissolve the compounds, and then 0.05 g of Aliquat 336 and 6 mL of 2.0 M potassium carbonate were added, and the mixture was refluxed and stirred at 120 DEG C for 2 hours. After completion of the reaction, the reaction mixture was washed with distilled water and the organic layer was extracted with toluene. Dried over magnesium sulfate, filtered through celite, and then subjected to column chromatography to obtain the final compound 8.

N - (4- (5,5-Dimethyl -9-phenyl- [5 H -naphth [3,2,1- de] anthracen-3-yl]) phenyl) - N -phenlybenzeneamine (8): ( yield = ^{71%), 1 H-NMR} : 8.85 (d, 1H), 8.12 (d, 1H), 7.96 (s, 1H), 7.76 (d, 1H), 7.61 (d, 4H), 7.55 (m, 4H) , 7.47 (m, 4H), 7.33 (m, 6H), 7.18 (m, 5H), 7.05 (t, 2H), 1.78 (s, 6H). APCI-MS (m / z): 613 [M ^< ⁺ &^gt;].

Experimental Example 1: Measurement of photophysical properties

Dichloromethane (10- ⁵ M) the UV-Vis absorption (Ultraviolet-visible spectroscopy) of the compound from the measured amount was obtained by using the Sinco S-3100, and a quartz cuvette (1.0 cm path). The photoluminescence spectra were measured using Aminobowman series 2 luminescence spectroscopy. The phosphor quantum yield of the synthesized material for DPA (Φ = 0.90) used as reference material was measured in dichloromethane at 293 K. The energy bandgap was determined from the intersection of the absorbance and the photoluminescence (PL) spectrum.

The results of measurement of the photophysical properties of the compounds 1 to 8 of the above Examples are shown in Table 1.

Example 5

A glass substrate coated with an indium tin oxide (ITO) thin film was used for OLED fabrication. The sheet resistance of the glass substrate was 12 Ω / square and the thickness was 1,000 Å. The ITO-coated glass was washed in an ultrasonic bath in the order of acetone, methyl alcohol, and distilled water, then left in isopropyl alcohol for 20 minutes and dried using a N ₂ gas gun. The substrate was treated with an O ₂ plasma in an Ar atmosphere. Organic layers comprising the compounds 1-8 of Examples 1-4 were deposited by thermal evaporation at a rate of 1.0 A / s onto the substrate in a highly resistively heated alumina crucible. All organic materials and metals were deposited under high vacuum (5.0 x 10 < ^-7 > Torr). The OLEDs according to this example were prepared in the following sequence: ITO / 4,4'-bis [N- (1-naphthyl) -N-phenylamino] -biphenyl (NPB, HTL) / Compounds 1 to 8 of Examples 1 to 4 (30 nm) / 4,7-diphenyl-1,10-phenanthroline (Bphen, ETL) (30 nm) / lithium quinolate (Liq) / Al (100 nM).

Experimental Example 2: Measurement of organic electroluminescence characteristics

The current-voltage-emission (JVL) characteristics and photoluminescence (EL) spectra of the OLED devices prepared as in Example 5 were measured using a Keithley 2400 source measurement unit and a CS 1000A spectrophotometer.

Figure 1 shows the structure of an OLED device comprising an organic electroluminescent device according to the present invention and the HOMO and LUMO energy levels of other materials in an OLED device. The device fabricated with the structure shown in FIG. 1 has the following arrangement, and its performance characteristics are shown in Table 2: ITO / 4,4'-bis (N- (1-naphthyl) ) Biphenyl (NPB) (50 nm) / compounds 1 to 8 of Examples 1 to 4 (30 nm) / 4,7-diphenyl-1,10-phenanthroline (Bphen) (30 nm) / lithium quinoline Rate (Liq) (2.0 nm) / Al (100 nm).

Figure 2 shows the normalized EL spectra of devices 1 to 8 comprising compounds 1 to 8 prepared as above. All devices exhibit efficient green emission with a peak emission peak of 471 nm to 525 nm. The CIE xy coordinates of devices 1 to 8 are (0.34, 0.49), (0.29, 0.52), (0.19, 0.50), (0.20, 0.50), (0.42, 0.55) 0.32, 0.58). 3 to 7 are graphs of current density-voltage (JV) characteristics (FIG. 3), emission-voltage (LV) characteristics graph (FIG. 4), current density graph A graph of power efficiency versus current density (Figure 6), and an external quantum efficiency graph (Figure 7) versus current density.

The device 1 to 8, the green device 7 is a CIE xy coordinates (0.30, 0.62) at 6.0 V, the maximum value of each of 10.76 cd / A, 11.37 lm / W, and 3.21% (10.50 cd at 20 mA / cm ² / A, 8.83 lm / W, and 3.13% EQE), respectively.

The results of measurement of the organic electroluminescence characteristics of the devices including the compounds 1 to 8 of the above Examples are shown in Table 2.

It will be understood by those of ordinary skill in the art that the foregoing description of the embodiments is for illustrative purposes and that those skilled in the art can easily modify the invention without departing from the spirit or essential characteristics thereof. It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive. For example, each component described as a single entity may be distributed and implemented, and components described as being distributed may also be implemented in a combined form.

The scope of the present invention is defined by the appended claims rather than the detailed description, and all changes or modifications derived from the meaning and scope of the claims and their equivalents should be interpreted as being included in the scope of the present invention .

Claims (6)

An organic luminescent compound represented by any one of the following formulas (3) to (6), (8) and (9)
(3)

;
[Chemical Formula 4]

;
[Chemical Formula 5]

;
[Chemical Formula 6]

;
[Chemical Formula 8]

;
[Chemical Formula 9]

.
delete delete Reacting a derivative of the anthracene compound represented by the following formula (10) with methyl magnesium chloride and methanesulfonic acid sequentially to prepare an organic luminescent compound represented by the following formula (2)
A derivative of the anthracene compound represented by the following formula (11) is reacted with

,

,

,

,

,

, And

To produce an organic luminescent compound represented by any one of the following Chemical Formulas 3 to 9
: ≪ / RTI >
(2)

;
(3)

;
[Chemical Formula 4]

;
[Chemical Formula 5]

;
[Chemical Formula 6]

;
(7)

;
[Chemical Formula 8]

;
[Chemical Formula 9]

;
[Chemical formula 10]

;
(11)

;
In the above formula, R ₃ is halogen.
delete An organic electroluminescent device comprising the organic electroluminescent compound according to claim 1.

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