KR20200103380A - Phosphine oxide compound and organic light emitting element comprising the same - Google Patents

Abstract

The present invention relates to a phosphine oxide compound and an organic light emitting device containing the same. The organic light emitting device of the present invention exhibits excellent efficiency characteristics by including the phosphine oxide compound of the present invention.

Description

Phosphine oxide compound and organic light-emitting device containing the same {PHOSPHINE OXIDE COMPOUND AND ORGANIC LIGHT EMITTING ELEMENT COMPRISING THE SAME}

The present invention relates to a phosphine oxide compound and an organic light emitting device comprising the same.

Organic light emitting diodes (OLEDs) are attracting attention as the demand for flat panel displays increases in recent years. In general, the organic light emission phenomenon refers to a phenomenon in which electrical energy is converted into light energy using an organic material.

Such an organic light-emitting device is a device that converts electrical energy into light by applying an electric current to an organic light-emitting material, and has a structure in which a functional organic material layer is inserted between an anode and a cathode. Here, the organic material layer is often made of a multilayer structure composed of different materials in order to increase the efficiency and stability of the organic light emitting device.For example, the organic material layer is composed of a hole injection layer, a hole transport layer, a light emitting layer, a hole blocking layer, an electron transport layer, an electron injection layer, etc. I can.

In the structure of such an organic light emitting device, when a voltage is applied between the two electrodes, holes from the anode and electrons from the cathode are injected into the organic material layer, and the injected holes and electrons meet and recombination. High-energy excitons are formed. At this time, the formed excitons move back to the ground state, and light having a specific wavelength is generated.

Recently, it has been known that not only a fluorescent light emitting material but also a phosphorescent light emitting material can be used as a light emitting material of an organic light emitting device, and this phosphorescent light emission is performed after electrons are transferred from a ground state to an excited state, and then intersystem crossing. ) Through the singlet excitons to the triplet excitons, and then the triplet excitons to the ground state, and the light emission is composed of a mechanism.

Patent Document 1: Korean Patent Registration No. 10-0846221

It is an object of the present invention to provide a new structure of a phosphine oxide compound and an organic light emitting device comprising the same.

Another object of the present invention is to provide a compound for an organic light emitting device having characteristics such as low driving voltage and high efficiency and long life.

In addition, it is to provide an image display device including the compound for an organic light emitting device.

The object of the present invention is achieved by a phosphine oxide compound represented by the following formula (1).

[Formula 1]

In Formula 1, L ₁ and L ₂ are each independently a phenylene group or a naphthalene group, and Ar ₁ is a substituted or unsubstituted C5-C30 aryl group, and a substituted or unsubstituted C5-C30 heteroaryl group. Is selected.

Ar ₁ is a substituted or unsubstituted phenyl group, a substituted or unsubstituted carbazolyl group, a substituted or unsubstituted phenanthrolinyl group, a substituted or unsubstituted benzoimidazolyl group, a substituted or unsubstituted triphenylenyl group, It may be selected from the group consisting of a substituted or unsubstituted pyridyl group, a substituted or unsubstituted pyrimidinyl group, a substituted or unsubstituted triazinyl group, a substituted or unsubstituted spirobifluorenyl group, and combinations thereof.

It is also an object of the present invention to include a first electrode, a second electrode, and one or more organic material layers positioned between the first and second electrodes, and at least one of the organic material layers is a phosphine oxide according to the present invention. It is achieved by an organic light-emitting device comprising a compound.

The organic material layer includes at least one layer selected from the group consisting of a light emitting layer, a hole injection layer, a hole transport layer, and a layer simultaneously injecting and transporting holes, and the at least one layer is a phosphine oxide compound according to the present invention. It may include.

The organic material layer includes at least one layer selected from the group consisting of a light emitting layer, an electron injection layer, an electron transport layer, and a layer that simultaneously injects and transports electrons, and the at least one layer is the phosphine oxide compound according to the present invention. It may include.

The organic material layer may include at least one charge generation layer (CGL), and the at least one layer may include the phosphine oxide compound according to the present invention.

According to the present invention, a new structure of a phosphine oxide compound is provided.

The novel phosphine oxide compound of the present invention can induce not only thermal stability of the organic material during the deposition process accompanying the fabrication of the organic light emitting device, but also low driving voltage, high efficiency, high brightness, and long lifespan of the applied organic light emitting device.

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

Advantages and features of the present invention, and a method of achieving them will become apparent with reference to embodiments described below in detail. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in various forms different from each other, and only these embodiments make the disclosure of the present invention complete, and common knowledge in the technical field to which the present invention pertains. It is provided to completely inform the scope of the invention to those who have it, and the invention is only defined by the scope of the claims.

The size and thickness of each component shown in the drawings are illustrated for convenience of description, and the present invention is not limited to the size and thickness of the illustrated component.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

The phosphine oxide compound according to the present invention is represented by the following formula (1).

[Formula 1]

In Formula 1,

L ₁ and L ₂ are each independently a phenylene group or a naphthalene group,

Ar ₁ is selected from the group consisting of a substituted or unsubstituted C5-C30 aryl group or a substituted or unsubstituted C5-C30 heteroaryl group.

Substituents that may be substituted for Ar ₁ include, but are not limited to, phenyl group, naphthyl group, anthracenyl group, phenanthryl group, m-biphenylyl group, p-biphenylyl group, p-terphenyl group, m-terphenyl group, triphenyl Renyl group, triazolyl group, pyridine group, pyrimidine group, and carbazole group are mentioned.

Specifically, in one embodiment of the present invention, a substituted or unsubstituted C5 to C30 aryl group and or a substituted or unsubstituted C5 to C30 heteroaryl group is a substituted or unsubstituted phenyl group, a substituted or unsubstituted naphth Tyl group, substituted or unsubstituted anthracenyl group, substituted or unsubstituted phenanthryl group, substituted or unsubstituted naphthacenyl group, substituted or unsubstituted pyrenyl group, substituted or unsubstituted biphenylyl group, substituted or unsubstituted P-terphenyl group, substituted or unsubstituted m-terphenyl group, substituted or unsubstituted chrysenyl group, substituted or unsubstituted triphenylenyl group, substituted or unsubstituted perylenyl group, substituted or unsubstituted Nyl group, substituted or unsubstituted furanyl group, substituted or unsubstituted thiophenyl group, substituted or unsubstituted pyrrolyl group, substituted or unsubstituted pyrazolyl group, substituted or unsubstituted imidazolyl group, substituted or unsubstituted tria Zolyl group, substituted or unsubstituted oxazolyl group, substituted or unsubstituted thiazolyl group, substituted or unsubstituted oxadiazolyl group, substituted or unsubstituted thiadiazolyl group, substituted or unsubstituted pyridyl group, substituted Or an unsubstituted pyrimidinyl group, a substituted or unsubstituted pyrazinyl group, a substituted or unsubstituted triazinyl group, a substituted or unsubstituted benzofuranyl group, a substituted or unsubstituted benzothiophenyl group, a substituted or unsubstituted benzo Imidazolyl group, substituted or unsubstituted indolyl group, substituted or unsubstituted quinolinyl group, substituted or unsubstituted isoquinolinyl group, substituted or unsubstituted quinazolinyl group, substituted or unsubstituted quinoxalinyl group, substituted Or unsubstituted naphthyridinyl group, substituted or unsubstituted benzoxazineyl group, substituted or unsubstituted benzthiazinyl group, substituted or unsubstituted acridinyl group, substituted or unsubstituted phenazineyl group, substituted or unsubstituted A phenothiazinyl group, a substituted or unsubstituted phenoxazineyl group, a substituted or unsubstituted phenanthrolinyl group, a substituted or unsubstituted carbazolyl group, a substituted or unsubstituted spirobifluorenyl group, or a combination thereof. , But is not limited thereto.

Preferably, Ar ₁ is a substituted or unsubstituted phenyl group, a substituted or unsubstituted carbazolyl group, a substituted or unsubstituted phenanthrolinyl group, a substituted or unsubstituted benzoimidazolyl group, a substituted or unsubstituted tree Phenylenyl group, substituted or unsubstituted pyridyl group, substituted or unsubstituted pyrimidinyl group, substituted or unsubstituted triazinyl group, substituted or unsubstituted spirobifluorenyl group, and combinations thereof I can.

For a specific example, the phosphine oxide compound according to the present invention may be a compound represented below.

The phosphine oxide compound according to the present invention can be described in more detail through the following Formula 2.

[Formula 2]

In order to make a high-efficiency organic light-emitting device stable, a band gap and energy level between materials must have an appropriate level. In addition, organic compounds must not exhibit denaturation at high temperatures to enable continuous and stable driving of the device.

The phosphine oxide compound represented by the above formula according to the present invention is designed to increase electron mobility by introducing phenylene or naphthalene into L ₁ or L ₂ centered on anthracene.

In more detail, thermal stability and electrical stability can be improved by introducing a phosphine structure into the compound of the present invention, and the lifespan of the device to which the compound of the present invention is applied is improved through stable driving. In addition, by introducing phenylene or naphthalene into the P atom of the phosphine oxide, the band level can be maintained at an appropriate level in the light emitting layer without affecting the three-dimensional structure of the compound, thereby facilitating the movement of electrons. However, if there is only phenyl group or naphthalene in the molecule, the LUMO value is low, so the energy barrier with the light emitting layer increases, so by introducing anthracene that has high intramolecular electrical mobility and can increase the LUMO value, it is adjusted to the energy level of the electron emitting layer. Electron movement can be facilitated. In addition, the phosphine oxide compound of the present invention may have a higher electron mobility by applying an electron-rich functional group to Ar in the above formula. As a result, the phosphine oxide compound according to the present invention can induce high efficiency and low driving voltage of the applied organic light emitting device.

A general method of manufacturing an organic light-emitting device includes a printing process made by dissolving a material and a deposition process made by sublimating a material by applying high temperature. Currently, the most commonly used method is the deposition process, and a roll to roll method is used to maximize productivity when mass production of organic light emitting devices applied with this deposition process is applied. At this time, the temperature of the crucible is lower than that of the organic material. It will maintain a high temperature. For this reason, in order to maximize the yield of a device that can be a product family, even if the compound maintains a high temperature for a long time, it must not be denatured.

The phosphine oxide compound of the present invention is a structure in which a functional group capable of hydrogen bonding is introduced into the linker moiety (L) as shown in Formula 3 below, and due to this structure, the compound of the present invention stabilizes the three-dimensional structure and provides improved thermal stability. Can have.

[Formula 3]

In the case of the electron transport layer, a structure in which electrons are deorganized is applied to increase the efficiency of electrons. However, when phenyl is used for the Ar group, the degree of deorganization is less than that of polycyclic aromatic hydrocarbons (PAH), which are known to be rich in electrons, and thus the efficiency of electron children is reduced. In addition, a high temperature is applied to the organic compound during deposition. As shown in Chemical Formula 3, since it has a melting point higher than that of a previously known perylene functional group (69.2°C), it has more thermal stability of the organic compound.

In addition, when a heteroaryl group is applied to the Ar group, there is no portion having an unsaturated bond in the organic compound. As a result, the resonance effect of the organic compound is increased, so that the stability and electrical properties of the compound are improved.

[Formula 4]

When hydrogen bonds are present in the molecule as in Chemical Formula 4, voltage efficiency is improved compared to conventional organic compounds that do not have hydrogen bonds when manufacturing an organic light emitting device. That is, the phosphine oxide compound of the present invention is a structure in which phenylene or naphthalene having less steric hindrance is introduced into the linker, or a functional group capable of hydrogen bonding to Ar is introduced, and the voltage efficiency of the organic light emitting device to which such compound is applied can be improved. I can.

1 is a cross-sectional view of an organic light emitting device according to an embodiment of the present invention. Referring to FIG. 1, the organic light-emitting device 1 has a tandem type structure, with a first electrode (anode, 110), a second electrode (cathode, 120), a first light-emitting unit 210, and a second light-emitting unit 220. , A third light emitting part 230, a first charge generating layer 240 and a second charge generating layer 250.

The first light emitting part 210, the second light emitting part 220, the third light emitting part 230, the first charge generation layer 240 and the second charge generation layer 250 are organic material layers and the first electrode 110 And the second electrode 120, the first charge generating layer 240 is positioned between the first light emitting portion 210 and the second light emitting portion 220, and the second charge generating layer 250 is It is located between the second light-emitting unit 220 and the third light-emitting unit 230.

The first light emitting part 210 is composed of a hole injection layer 211, a first hole transport layer 212, a first light emitting layer 213, and a first electron transport layer 214, and the second light emitting part 220 is 2 consists of a hole transport layer 221, a second light emitting layer 222, and a second electron transport layer 223, and the third light emitting part 230 is a third hole transport layer 231, a third light emitting layer 232, and a third It consists of an electron transport layer 233 and an electron injection layer 234.

The first charge generation layer 240 is composed of an n-type charge generation layer 241 and a p-type charge generation layer 242, and the second charge generation layer 250 is an n-type charge generation layer 251 and a p-type. It consists of a charge generation layer 252. The n-type charge generation layers 241 and 251 may be doped with an alkali metal.

The phosphine oxide compound according to the present invention comprises a first electron transport layer 214, a second electron transport layer 223, a third electron transport layer 233, an electron injection layer 234, a first charge generation layer 240 and/ Alternatively, it may be included in the second charge generating layer 250 and used, and in particular, may be used for the n-type charge generating layers 241 and 251.

The described organic light emitting device 1 can be variously modified. Some organic layers may be omitted or added, may not be in a tandem form, and may be in a tandem form having two or four or more emission layers. Further, the organic light-emitting device 1 may include an organic layer including a layer that simultaneously transports electrons and injects electrons, and even in this case, the phenanthroline compound according to the present invention may be used.

Hereinafter, examples and comparative examples of the preparation of the phosphine oxide compound and the organic light emitting device according to the present invention will be described. However, the preparation examples and examples described below are for illustrative purposes only, and should not be interpreted as limiting the present invention by the preparation examples and examples described below.

Example

Synthesis of intermediates

Synthesis Example of Intermediate A-1

Intermediate B-1 (100 g, 0.28 mol) and Intermediate B-2 (74.6 g, 0.336 mol) were well dissolved in toluene and ethanol in a two necked round bottom flask. After dissolving K ₂ CO ₃ (115.9 g, 0.84 mol) in distilled water, it was added to the reaction solution. After degassing, Pd(PPh ₃ ) ₄ (9.7 g, 3% w/w) was added and refluxed for 4 hours. The reaction was terminated by adding an excess of water, followed by extraction with methylene chloride. The organic layer was dried over anhydrous MgSO ₄ and the solvent was removed using a rotary evaporator. Separated by column chromatography using a methylene chloride solvent to obtain 95 g (75%) of compound A-1.

Synthesis Example of Intermediate A-2

Intermediate A-1 (80 g, 0.17 mol) and compound NBS (N-Bromosuccinimide) (37.45 g, 0.21 mol) were dissolved in DMF (Dimethylformamide) and refluxed for 1 hour in a 2-neck round bottom flask. The reaction was terminated by adding an excess of water, and the precipitated solid was filtered to give 83.41 g (89%) as compound A-2.

Synthesis Example of Intermediate A-3

Intermediate B-1 (50 g, 0.14 mol) and Intermediate B-2 (37.3 g, 0.168 mol) were well dissolved in toluene and ethanol in a two necked round bottom flask. After dissolving K ₂ CO ₃ (57.5 g, 0.42 mol) in distilled water, it was added to the reaction solution. After degassing, Pd(PPh ₃ ) ₄ (4.35 g, 3 %w/w) was added and refluxed for 3 hours. The reaction was terminated by adding an excess of water, followed by extraction with methylene chloride. The organic layer was dried over anhydrous MgSO ₄ and the solvent was removed using a rotary evaporator. Separated by column chromatography using a methylene chloride solvent to give 43 g (69%) as compound A-3.

Synthesis Example of Intermediate A-4

Intermediate A-3 (40 g, 0.08 mol) and compound NBS (18.7 g, 0.105 mol) were dissolved in DMF in a two necked round bottom flask and refluxed for 1 hour. The reaction was terminated by adding an excess of water, and the precipitated solid was filtered to obtain 38.73 g (91%) as compound A-4.

Synthesis Example of Intermediate A-5

After adding 200 ml of anhydrous THF and intermediate B-4 (20 g, 70 mmol) to a flask substituted with N ₂ , 28 ml of n-BuLi was added dropwise while maintaining -78°C. After stirring for 1 h, chlorodiphenylphosphine (14.02 g, 64 mmol) was dissolved in 200 ml of THF, added dropwise, and stirred at room temperature for 12 hours. The reaction solution was extracted 5 times with 400 ml of EA and 100 ml of water, and the organic layer was dried over anhydrous MgSO ₄ , and an excessive amount of H ₂ O ₂ was added, and the solvent was removed using a rotary evaporator. Separated by column chromatography using an MC solvent to obtain 19 g (73%) as Intermediate A-5.

Synthesis Example of Intermediate A-6

Toluene and ethanol were added to a three necked round bottom flask, and then Intermediate A-5 (19 g, 24.56 mol) and Intermediate B-2 (10.36 g, 51.32 mmol) were added and stirred. After dissolving K ₂ CO ₃ (9.67 g, 69.98 mmol) in distilled water, it was added to the reaction solution. After N ₂ substitution, Pd(PPh ₃ ) ₄ (1.6 g, 1.5 %w/w) was added and refluxed for 11 hours. After the reaction was terminated, extraction was performed three times with 500 ml of methylene chloride and 500 ml of water. The organic layer was dried over anhydrous MgSO ₄ and the solvent was removed using a rotary evaporator. Separated by column chromatography using MC/EA (100/1, v/v) solvent to obtain 21 g (89%) as Intermediate A-6.

Synthesis Example of Intermediate A-7

Intermediate A-6 (21 g, 41.62 mmol) and compound NBS (8.89 g, 49.95 mmol) were dissolved in DMF in a two necked round bottom flask and refluxed for 1 hour. The reaction was terminated by adding an excess of water, and the precipitated solid was filtered to obtain 20 g (82%) as an intermediate A-7.

Preparation Example of Compound 1

In a two neck round bottom flask, Intermediate A-2 (10 g, 0.018 mol) and Intermediate B-3 (9.79 g, 0.022 mol) are well dissolved in toluene and ethanol. After dissolving K ₂ CO ₃ (7.46 g, 0.054 mol) in distilled water, it was added to the reaction solution. After degassing, Pd(PPh ₃ ) ₄ (0.62g, 3%w/w) was added and refluxed for 4 hours. The reaction was terminated by adding an excess of water, followed by extraction with methylene chloride. The organic layer was dried over anhydrous MgSO ₄ and the solvent was removed using a rotary evaporator. After separation by column chromatography using MC/MEOH (100/1, v/v) solvent, 6.5 g (48%) of compound 1 was obtained.

Preparation example of compound 2

Intermediate A-2 (10 g, 0.018 mol) and Intermediate B-4 (9.63 g, 0.021 mol) were well dissolved in toluene and ethanol in a two necked round bottom flask. After dissolving K ₂ CO ₃ (7.40 g, 0.052 mol) in distilled water, it was added to the reaction solution. After degassing, Pd(PPh ₃ ) ₄ (0.59 g, 3 %w/w) was added and refluxed for 11 hours. The reaction was terminated by adding an excess of water, followed by extraction with methylene chloride. The organic layer was dried over anhydrous MgSO ₄ and the solvent was removed using a rotary evaporator. Separated by column chromatography using MC/EA (10/1, v/v) solvent to obtain 7.67 g (56%) as compound 1.

Preparation Example of Compound 3

Intermediate A-2 (10 g, 0.018 mol) and Intermediate B-5 (6.09 g, 0.0216 mol) were well dissolved in toluene and ethanol in a two necked round bottom flask. After dissolving K ₂ CO ₃ (7.40 g, 0.052 mol) in distilled water, it was added to the reaction solution. After degassing, Pd(PPh ₃ ) ₄ (0.59 g, 3 %w/w) was added and refluxed for 11 hours. The reaction was terminated by adding an excess of water, followed by extraction with methylene chloride. The organic layer was dried over anhydrous MgSO ₄ and the solvent was removed using a rotary evaporator. Separated by column chromatography using MC/EA (10/1, v/v) solvent to obtain 5.69 g (52%) as compound 3.

Preparation example of compound 4

In a two neck round bottom flask, Intermediate A-2 (10 g, 0.018 mol) and Intermediate B-6 (10.48 g, 0.0216 mol) are well dissolved in toluene and ethanol. After dissolving K ₂ CO ₃ (7.40 g, 0.052 mol) in distilled water, it was added to the reaction solution. After degassing, Pd(PPh ₃ ) ₄ (0.59 g, 3 %w/w) was added and refluxed for 11 hours. The reaction was terminated by adding an excess of water, followed by extraction with methylene chloride. The organic layer was dried over anhydrous MgSO ₄ and the solvent was removed using a rotary evaporator. Separated by column chromatography using MC/EA (10/1, v/v) solvent to obtain 6.86 g (47%) as compound 4.

Preparation example of compound 5

Intermediate A-3 (10 g, 0.018 mol) and Intermediate B-3 (9.79 g, 0.022 mol) were well dissolved in toluene and ethanol in a two necked round bottom flask. After dissolving K ₂ CO ₃ (7.40 g, 0.052 mol) in distilled water, it was added to the reaction solution. After degassing, Pd(PPh ₃ ) ₄ (0.59 g, 3% w/w) was added and refluxed for 11 hours. The reaction was terminated by adding an excess of water, followed by extraction with methylene chloride. The organic layer was dried over anhydrous MgSO ₄ and the solvent was removed using a rotary evaporator. Separated by column chromatography using MC/MEOH (100/1, v/v) solvent to obtain 8.49 g (62%) as compound 5.

Preparation example of compound 6

Intermediate A-3 (10 g, 0.018 mol) and Intermediate B-8 (9.79 g, 0.022 mol) were well dissolved in toluene and ethanol in a two necked round bottom flask. After dissolving K ₂ CO ₃ (7.40 g, 0.052 mol) in distilled water, it was added to the reaction solution. After degassing, Pd(PPh ₃ ) ₄ (0.59 g, 3% w/w) was added and refluxed for 11 hours. The reaction was terminated by adding an excess of water, followed by extraction with methylene chloride. The organic layer was dried over anhydrous MgSO ₄ and the solvent was removed using a rotary evaporator. Separated by column chromatography using MC/MEOH (100/1, v/v) solvent to obtain 8.6 g (61%) as compound 6.

Preparation example of compound 7

Intermediate A-2 (10 g, 0.018 mol) and Intermediate B-9 (9.79 g, 0.022 mol) were well dissolved in toluene and ethanol in a two necked round bottom flask. After dissolving K ₂ CO ₃ (7.40 g, 0.052 mol) in distilled water, it was added to the reaction solution. After degassing, Pd(PPh ₃ ) ₄ (0.59 g, 3% w/w) was added and refluxed for 11 hours. The reaction was terminated by adding an excess of water, followed by extraction with methylene chloride. The organic layer was dried over anhydrous MgSO ₄ and the solvent was removed using a rotary evaporator. Separated by column chromatography using MC/MEOH (100/1, v/v) solvent to obtain 8.22 g (60%) as compound 7.

Preparation Example of Compound 8

Toluene and ethanol were added to a three necked round bottom flask, and then Intermediate A-7 (14 g, 24 mmol) and Intermediate B-10 (6.77 g, 24 mmol) were added and stirred. After dissolving K ₂ CO ₃ (4.97 g, 36 mmol) in distilled water, it was added to the reaction solution. After N ₂ substitution, Pd(PPh ₃ ) ₄ (0.41 g, 1.5 %w/w) was added and refluxed for 11 hours. After the reaction was terminated, extraction was performed three times with 500 ml of methylene chloride and 500 ml of water. The organic layer was dried over anhydrous MgSO ₄ and the solvent was removed using a rotary evaporator. Separated by column chromatography using MC/EA (100/50, v/v) solvent to obtain compound 8 (10 g, 63%).

Preparation Example of Compound 9

Intermediate A-2 (10 g, 0.018 mol) and Intermediate B-11 (7.97 g, 0.022 mol) were well dissolved in toluene and ethanol in a two necked round bottom flask. After dissolving K ₂ CO ₃ (7.40 g, 0.052 mol) in distilled water, it was added to the reaction solution. After degassing, Pd(PPh ₃ ) ₄ (0.59 g, 3 %w/w) was added and refluxed for 11 hours. The reaction was terminated by adding an excess of water, followed by extraction with methylene chloride. The organic layer was dried over anhydrous MgSO ₄ and the solvent was removed using a rotary evaporator. Separated by column chromatography using MC/MEOH (100/1, v/v) solvent to obtain 9.13 g (73%) as compound 9.

Preparation Example of Compound 10

Intermediate A-2 (10 g, 0.018 mol) and Intermediate B-12 (7.7 g, 0.022 mol) were well dissolved in toluene and ethanol in a two necked round bottom flask. After dissolving K ₂ CO ₃ (7.40 g, 0.052 mol) in distilled water, it was added to the reaction solution. After degassing, Pd(PPh ₃ ) ₄ (0.59 g, 3 %w/w) was added and refluxed for 11 hours. The reaction was terminated by adding an excess of water, followed by extraction with methylene chloride. The organic layer was dried over anhydrous MgSO ₄ and the solvent was removed using a rotary evaporator. Separated by column chromatography using MC/MEOH (100/1, v/v) solvent to give 11.1 g (82%) as compound 10.

Preparation Example of Compound 11

Intermediate A-2 (10 g, 0.018 mol) and intermediate B-14 (9.42 g, 0.022 mol) were well dissolved in toluene and ethanol in a two necked round bottom flask. After dissolving K ₂ CO ₃ (7.40 g, 0.052 mol) in distilled water, it was added to the reaction solution. After degassing, Pd(PPh ₃ ) ₄ (0.59 g, 3 %w/w) was added and refluxed for 11 hours. The reaction was terminated by adding an excess of water, followed by extraction with methylene chloride. The organic layer was dried over anhydrous MgSO ₄ and the solvent was removed using a rotary evaporator. Separated by column chromatography using MC/MEOH (100/1, v/v) solvent to obtain 10.07 g (74%) as compound 11.

Table 1 shows the ¹ H NMR and MASS / FAB of the composite material. Among the abbreviations used in the ¹ H NMR analysis result, s is a singlet, d is a doublet, t is a triplet, g is a quartet, and m is a multiplet.

Compound number ¹ H NMR (CDCl _3, 500Mz) MASS Found Calculated Compound 1 9.03-9.01 (d, 2H), 8.86-8.84 (d, 4H), 7.95-7.90 (m, 2H), 7.88-7.85 (m, 4H), 7.79-7.77 (m, 2H), 7.73-7.71 (m , 2H), 7.67-7.56 (m, 16H), 7.40-7.37 (m, 4H) C53H36N3OP 762.1(n+1) Compound 2 8.98-8.96 (d, 2H), 8.38-8.36 (d, 4H), 8.11 (s, 1H), 7.94-7.81 (m, 8H), 7.69-7.57 (m, 18H), 7.40-7.35 (m, 4H) ) C54H37N2OP 761.4(n+1) Compound 3 8.90-8.89 (d, 2H), 8.70-8.68 (d, 2H), 7.93-7.80 (m, 6H), 7.77-7.75 (d,2H), 7.64-7.54 (m, 12H), 7.32-7.33 (m , 4H), 7.28-7.25 (m, 1H) C42H29N2OP 609.2(n+1) Compound 4 9.31-9.29 (d, 1H), 8.87-8.85 (d, 4H), 8.73-8.72 (d, 1H), 7.99-7.85 (m, 6H), 7.80-7.76 (d, 1H), 7.59-7.53 (m , 19H), 7.39-7.36 (m, 2H), 7.32-7.31 (d, 2H), 7.29-7.25 (m, 2H) C57H38N3OP 812.2(n+1) Compound 5 8.97-8.95 (m, 2H), 8.37-8.35 (d, 4H), 8.11 (s, 1H), 8.03-7.99 (m, 1H), 7.81-7.45 (m, 24H), 7.37-7.33 (m, 4H) ) C53H36N3OP 761.3(n+1) Compound 6 9.02-9.05 (d, 1H), 8.90-8.88 (d, 1H), 8.76-8.74 (m, 4H), 8.06-7.99 (m, 1H), 7.84-7.75 (m, 13H), 7.63-7.45 (m) , 12H), 7.36-7.35 (m, 4H) C53H36N3OP 762.2(n+1) Compound 7 9.46 (s, 1H), 8.74-8.73 (d, 2H), 8.60-8.59 (d, 1H), 8.15 (s, 1H), 8.01 (s, 1H), 8.02-8.01 (d, 1H), 7.94- 7.83 (m, 3H), 7.81-7.77 (m, 1H), 7.69-7.60 (m, 4H), 7.56-7.58 (m, 2H), 7.55-7.50 (m, 1H), 7.40-7.38 (m, 2H) ) C53H36N3OP 762.3(n+1) Compound 8 8.89-8.88 (d, 2H), 8.70-8.69 (d, 2H), 8.33-8.31 (d, 1H), 8.12-8.07 (m, 2H), 8.01 (s, 1H), 7.82-7.73 (m, 8H) ), 7.67-7.64 (m, 4H), 7.57-7.56 (m, 2H), 7.50-7.47 (m, 4H), 7.36-7.30 (m, 4H), 7.26-7.25 (d, 1H) C46H31N2OP 659.2(n+1) Compound 9 8.12-7.92 (m, 8H), 7.81-7.76 (m, 8H), 7.64-7.55 (m, 6H), 7.49-7.25 (m, 10H), 7.19-7.08 (m, 2H) C50H34NOP 696.3(n+1) Compound 10 7.98-7.97 (d, 2H), 7.96-7.93 (d, 2H), 7.93-7.92 (d, 1H), 7.91-7.89 (d, 1H), 7.88 (s, 1H), 7.88-7.87 (d, 2H) ), 7.86-7.84 (m, 2H), 7.84-7.80 (m, 2H), 7.79-7.77 (m, 4H) C56H39OP 759.3(n+1) Compound 11 8.95 (s, 1H), 8.72-8.70 (d, 2H), 8.66-8.65 (d, 3H), 8.04-8.02 (d, 1H), 8.00-7.98 (d, 1H), 7.96-7.84 (m, 8H) ), 7.77-7.76 (t, 1H), 7.68-7.61 (m, 10H), 7.59-7.54 (m, 5H), 7.41-7.39 (m, 4H) C56H37OP 757.2(n+1)

The present inventors predicted that when a substance was introduced into the anthracene without a separate linker, such as the compound of Formula 5 below, a steric hindrance occurred and the thermal stability of the substance was degraded, and it was confirmed through the experimental results below. Comparative Compounds 1 to 6 were each carried out by applying the corresponding Ar ₁ to the structure of Formula 5.

[Formula 5]

Table 2 below shows the HPLC results of organic substances in which the temperature was maintained in a vacuum state for 5 days by raising the temperature by 50° C. above the temperature at which the material was sublimated.

Substance name Sublimation temperature Storage temperature HPLC before thermal stability test HPLC after thermal stability test Comparative compound 1 300 350 99.9% 86.5% Comparative compound 2 300 350 99.9% 90.3% Comparative compound 3 360 410 99.9% 83.6% Comparative compound 4 330 380 99.9% 91.0% Comparative compound 5 300 350 99.9% 82.3% Comparative compound 6 280 330 99.9% 84.9% Compound 1 300 350 99.9% 99.8% Compound 2 300 350 99.9% 99.5% Compound 3 310 360 99.9% 99.6% Compound 4 300 350 99.9% 99.5% Compound 5 300 350 99.9% 99.6% Compound 6 300 350 99.9% 99.9% Compound 7 290 340 99.9% 99.8% Compound 8 315 365 99.9% 99.8% Compound 9 300 350 99.9% 99.5% Compound 10 320 370 99.9% 99.3% Compound 11 300 350 99.9% 99.1%

Looking at the results in the table above, it can be seen that the results of compounds 1 to 11 in which phenylene or naphthalene was introduced as a linker showed less denaturation than the HPLC results of Comparative Compounds 1 to 6 in which a functional group was introduced without a separate linker to anthracene. Through this, it can be seen that the thermal stability of the compound is significantly improved than that of the anthracene compound into which the previously known phosphine oxide is introduced.

Manufacturing of organic light emitting device

1. Preparation Example of Comparative Example a

After patterning the ITO substrate so that the luminous area was 2 mm × 2 mm in size, each was cleaned with isopropyl alcohol and UV ozone. Thereafter, the ITO substrate was mounted on the substrate holder of the vacuum evaporation apparatus, and the pressure was held so that the degree of vacuum was 1 × 10 ^-7 torr. After that, plasma treatment was performed for 3 minutes under an N ₂ atmosphere.

And first, the HAT-CN compound was vacuum-deposited to form a thickness of 5 nm. This compound acts as a hole injection layer. On this, an NPB material was formed with a thickness of 50 nm as a first hole transport layer. Subsequently, the HT-1 material was formed to a thickness of 10 nm as a second hole transport layer.

Thereafter, a green light emitting layer was formed by co-depositing a GH-1 material as a host and a GD-1 material as a dopant to a thickness of about 10% at a thickness of 30 nm.

An electron transport layer was formed by depositing 35 nm of an ET-1 compound and a Liq material at a ratio of 5:5 on the emission layer. Thereafter, a LiF material was deposited to form an electron injection layer with a thickness of 1 nm. Thereafter, Al was deposited to a thickness of 100 nm to form a cathode to fabricate an organic EL device.

2. Preparation Example of Comparative Example b

In the same manner as in Comparative Example a described above, only the electron transport layer material was changed to Comparative Compound 5 to produce an organic light emitting device.

3. Preparation Example of Example 1

In the same manner as in Comparative Example a described above, only the electron transport layer material was changed to Compound 1 to produce an organic light emitting device.

4. Preparation Example of Example 2

The organic light emitting device was manufactured in the same manner as in Comparative Example a described above, but only the electron transport layer material was changed to Compound 2.

5. Preparation Example of Example 3

In the same manner as in Comparative Example a described above, only the electron transport layer material was changed to Compound 4 to produce an organic light-emitting device.

6. Preparation Example of Example 4

In the same manner as in Comparative Example a described above, but only the electron transport layer material was changed to Compound 5 to produce an organic light emitting device.

7. Preparation Example of Example 5

The organic light emitting device was manufactured in the same manner as in Comparative Example a described above, but only the electron transport layer material was changed to Compound 6.

8. Preparation Example of Example 6

In the same manner as in Comparative Example a described above, only the electron transport layer material was changed to Compound 9 to produce an organic light-emitting device.

9. Preparation Example of Example 7

In the same manner as in Comparative Example a described above, but only the electron transport layer material was changed to Compound 10 to produce an organic light emitting device.

A constant current of 10 mA/cm ² was applied to the organic light-emitting devices prepared according to Examples 1 to 7, and Comparative Examples a and b of the present invention, and the luminescence characteristics were measured with PR-670 of photoresearch.

Hereinafter, the driving current, driving voltage, current efficiency, and external quantum efficiency of the organic light-emitting devices of Examples 1 to 7 and Comparative Examples a and b were measured and shown in Table 3 below.

matter Driving current
J(mA/cm ² ) Driving voltage
(Voltage) Current efficiency
(cd/A) EQE
(%) Comparative Example a ET-1 10 4.70 55.0 17.0 Comparative Example b Comparative compound 5 10 5.12 45.1 14.4 Example 1 Compound 1 10 3.87 58.6 18.4 Example 2 Compound 2 10 3.97 58.5 18.8 Example 3 Compound 4 10 4.37 57.3 18.3 Example 4 Compound 5 10 3.84 58.4 18.6 Example 5 Compound 6 10 4.48 57.4 18.1 Example 6 Compound 9 10 4.38 57.9 18.0 Example 7 Compound 10 10 4.49 56.0 18.3

From Table 3, it can be seen that the driving voltage, current efficiency, and external quantum efficiency of the organic light emitting devices of Examples 1 to 7 are superior to the driving voltage, current efficiency, and external quantum efficiency of the organic light emitting devices of Comparative Examples a and b. .

The present invention is not necessarily limited to these embodiments, and various modifications may be made without departing from the spirit of the present invention. Accordingly, the embodiments disclosed in the present invention are not intended to limit the technical idea of the present invention, but to explain the technical idea, and the scope of the technical idea of the present invention is not limited by these embodiments. Therefore, it should be understood that the embodiments described above are illustrative and non-limiting in all respects. The scope of protection of the present invention should be interpreted by the following claims, and all technical ideas within the scope equivalent thereto should be interpreted as being included in the scope of the present invention.

Claims (7)

Phosphine oxide compound represented by the following formula 1:
[Formula 1]

In Formula 1,
L ₁ and L ₂ are each independently a phenylene group or a naphthalene group,
Ar ₁ is selected from the group consisting of a substituted or unsubstituted C5-C30 aryl group and a substituted or unsubstituted C5-C30 heteroaryl group. The method of claim 1, wherein Ar ₁ is a substituted or unsubstituted phenyl group, a substituted or unsubstituted carbazolyl group, a substituted or unsubstituted phenanthrolinyl group, a substituted or unsubstituted benzoimidazolyl group, a substituted or unsubstituted From the group consisting of a substituted triphenylenyl group, a substituted or unsubstituted pyridyl group, a substituted or unsubstituted pyrimidinyl group, a substituted or unsubstituted triazinyl group, a substituted or unsubstituted spirobifluorenyl group, and combinations thereof Phosphine oxide compound, characterized in that selected. The phosphine oxide compound according to claim 1, wherein the compound represented by Formula 1 is selected from the group consisting of compounds represented below:

First electrode,
A second electrode, and
It includes at least one organic material layer positioned between the first electrode and the second electrode,
At least one of the organic material layers is an organic light-emitting device comprising the phosphine oxide compound according to any one of claims 1 to 3. The method of claim 4, wherein the organic material layer comprises at least one layer selected from the group consisting of a light emitting layer, a hole injection layer, a hole transport layer, and a layer that simultaneously injects and transports holes, and the at least one layer is a first An organic light-emitting device comprising the phosphine oxide compound according to any one of claims to 3. The method of claim 4, wherein the organic material layer comprises at least one layer selected from the group consisting of a light emitting layer, an electron injection layer, an electron transport layer, and a layer that simultaneously injects and transports electrons, and the at least one layer is a first An organic light-emitting device comprising the phosphine oxide compound according to any one of claims to 3. The method of claim 4, wherein the organic material layer comprises at least one charge generation layer (CGL), and the at least one layer comprises the phosphine oxide compound according to any one of claims 1 to 3 Organic light-emitting device comprising a.

Images