KR20060023046A - Novel organic compound and organic light emitting device using same - Google Patents

Abstract

The present invention provides a compound of Formula 1 and an organic light emitting device using the same.

[Formula 1]

In the above formula, R1 to R4, X, L, m and n are as defined in the specification. The compound of Formula 1 may play a role of electron injection and transport or a light emitting material in the organic light emitting device, the organic light emitting device of the present invention exhibits excellent characteristics in terms of efficiency, driving voltage, stability.

Organic light emitting device, organic material layer, electron injection and transport layer, light emitting layer

Description

Novel organic compound and organic light emitting device using the same {NEW ORGANIC COMPOUND AND ORGANIC ELECTROLUMINESCENT DEVICE USING THE SAME}

1 is a cross-sectional view showing an example of a general organic light emitting device structure to which the compound of the present invention can be applied.

The present invention relates to a novel organic compound and an organic light emitting device using the same.

An organic light emitting device generally has a structure in which an anode, a cathode, and an organic material layer composed of a single molecule or a polymer are stacked between these electrodes, and electrons and holes injected into the organic material layer from the cathode and the anode form excitons. It uses the principle that light of a certain wavelength is generated when it falls to the ground state.

The principle of such an organic light emitting device was first discovered in 1965 from single crystals of anthracene by Pope et al. Subsequently, an organic electroluminescent device was proposed in 1987 by Kodak's Tang, which has a functional separation type laminated structure in which an organic material layer is divided into two layers, a hole transport layer and a light emitting layer. In such an organic light emitting device, a low voltage of 10 V or less is proposed. Also, it was confirmed that high emission luminance of 1000 cd / m 2 or more was obtained (Tang, CW; Van Slyke, SA AppL, Phys. Lett . 1987, 51 , 913.). As a result, organic electroluminescent devices have begun to receive great attention, and research on organic electroluminescent devices having a stacked structure of a function separation type is being actively conducted.

The structure of a general organic light emitting device having a stacked structure of a function separation type is illustrated in FIG. 1. The organic light emitting device of FIG. 1 is composed of a substrate 1, an anode 2, a hole injection layer 3, a hole transport layer 4, a light emitting layer 5, an electron transport layer 6 and a cathode 7. In some cases, a light emitting layer may be formed by doping a small amount of fluorescent or phosphorescent dye to the electron transport layer 6 or the hole transport layer 4 without a separate light emitting layer 5, or in the case of using a polymer, the hole transport layer 4 In addition, one polymer may play the role of the light emitting layer 5 and the electron transport layer 6 at the same time. In addition, a separate electron injection layer may be inserted between the electron transport layer 6 and the cathode 7 for efficient injection of electrons from the cathode.

On the other hand, many compounds having a heterocycle as a material for electron injection and electron transport layer or a light emitting layer used to form an organic material layer of an organic light emitting device have been studied. For example, an organic single molecule having a pyrrole compound, an imidazole compound, an oxazloe compound, or a thiazole compound, an oxadiazo compound, a pyrazine compound Many substances have been reported.

European Patent No. 1084127 B1 discloses that the metal complex compounds of the imidazole group, the oxazole group or the thiazole group have a band gap of blue light emission, and when these compounds are applied as the light emitting layer of the organic light emitting device, It is described to exhibit excellent electron transport properties even when applied to the electron transport layer. However, although the metal complex organic compounds have excellent thermal stability, they are unstable to oxygen or moisture and are more difficult to manufacture and purify than organic monomolecular compounds.

U.S. Patent No. 5,766,779 describes an example in which an organic material containing 2 to 8 functional groups such as an imidazole group, an oxazole group or a thiazole group is applied to an electron transport layer of an organic light emitting device. U. S. Patent No. 5,645, 948 describes a material for an electron transporting layer having imidazole groups, which has a structure containing three N-phenyl benzimidazole groups at the 1, 3 and 5-substituted positions of benzene. These compounds function not only to transport electrons but also to block holes from the light emitting layer. However, the material has a low stability, which is difficult to apply to the actual device.

Korean Patent Publication No. 10-2003-0067773 discloses organic monomolecular materials having functional groups such as imidazole group, oxazole group or thiazole group, which are excellent as electron injection and electron transport layer materials or light emitting layer materials of an organic light emitting device. have.

U.S. Patent No. 5,861,219 has an example in which 5-hydroxyquinoxaline is prepared from various metal complex compounds and used as a light emitting layer and an electron injection layer.

In Korean Patent Registration No. 10-0377321, compounds having pyrazine or quinoxaline functional groups are applied to an organic light emitting device, and these materials show excellent performance when applied as an electron transport and electron injection layer material or as a hole injection layer material. It is described as.                         

Various heterocyclic compounds presented in the above documents have been known to have excellent electron injection and transport properties, but due to their physical and chemical changes, photochemical and electrochemical changes, peeling and melting, crystallization and pyrolysis, Yet, when applied to an organic light emitting device, it is difficult to simultaneously satisfy high brightness and high lifetime at low voltage, and there are problems such as low durability and reliability of the device. Due to these problems, there are many difficulties in commercializing the above-described compounds in organic light emitting devices, and there are limitations in the application to various displays.

Accordingly, the present invention provides various compounds and organic light emitting devices using the same that can overcome the above-mentioned problems.

The present inventors have synthesized a novel structure of a compound combining heterocyclic groups in order to solve the above-mentioned problems of the prior art, and found that it can play an electron injection and transport role and / or a light emission role in an organic light emitting device. . In addition, it has been found that when the compound of the novel structure is applied to an organic light emitting device, the efficiency, driving voltage, and the like of the organic light emitting device can be improved.

Accordingly, an object of the present invention is to provide a compound having a novel structure and an organic light emitting device using the same.

The present invention provides a compound of formula                     

In Chemical Formula 1,

R1 and R2 are each or simultaneously hydrogen atoms; Alicyclic hydrocarbons having 1 to 24 carbon atoms, aromatic compounds, and heterocyclic compounds containing an element selected from the group consisting of nitrogen, oxygen and sulfur as ring members; R1 and R2 together form a condensed ring selected from the group consisting of aliphatic ring compounds having 5 to 32 carbon atoms, aromatic ring compounds, and heterocyclic compounds containing an element selected from the group consisting of nitrogen, oxygen and sulfur as ring members; and;

R3 and R4 are each aromatic compounds, or R3 and R4 are condensed to form an aromatic ring compound;

L is an aromatic compound; Heterocyclic compounds containing an element selected from the group consisting of nitrogen, oxygen and sulfur as ring members; And it is selected from the group consisting of C2-C32 unsaturated aliphatic hydrocarbons,

X is selected from the group consisting of oxygen, sulfur and NR 5, wherein R 5 is selected from the group consisting of aromatic compounds and aliphatic hydrocarbons having 1 to 24 carbon atoms,

n is 0 or 1,

m is 1 or 2.                     

In addition, the present invention is an organic light emitting device comprising a first electrode, an organic material layer consisting of one or more layers and a second electrode in a stacked form, wherein one or more layers of the organic material layer comprises a compound of Formula 1 An organic light emitting device is provided.

Hereinafter, the present invention will be described in detail.

The compound of Formula 1 is a novel compound, and has a characteristic structure including any one of imidazole group, oxazole group and thiazole group and quinoxaline in one molecule. As described above in the prior art, it is known that many organic substances including imidazole group, oxazole group, thiazole group or quinoxaline group can be used as electron injecting and transporting or light emitting materials in organic light emitting devices, and among these compounds, They are known to have an important influence on the role of electron injection or transport or light emission. Accordingly, the inventors have discovered a novel structure of a compound including an imidazole group, an oxazole group and a thiazole group and a quinoxaline group and have synthesized the same.

The compound of Formula 1 has a characteristic structure including any one of imidazole group, oxazole group and thiazole group and a quinoxaline group for functioning as an electron injection or transport or a light emitting material and electron injection or transport in an organic light emitting device It can act as a material and / or a light emitting host. Specifically, it is as follows.

Considering the energy bandgap of organic materials known to date in the field of organic light emitting devices, LUMO (lowest) is used as an electron injection or transport material to prevent electrons from being injected and transported easily from the cathode and holes injected from the anode to the cathode. It is preferable to use a material having an unoccupied molecular orbital level of 2.7 eV to 3.4 eV and a HOOC (highest occupied molecular orbital) level of 5.7 eV to 6.2 eV. Alq3, which has been used as a conventional electron injection or transport material, has a HOMO of 5.8 eV and a LUMO of 3.1 eV. The Alq3 material is widely known as a light emitting layer material, and even in a device using Alq3 as a light emitting layer, electron transport may be efficiently performed when a compound having a HOMO greater than 5.8 eV and a LUMO level of 3.1 eV is used as an electron transport layer material. You can expect that there is.

Since the compound of Formula 1 has any one of imidazole, thiazole, and oxazole groups having excellent electron affinity and a quinoxaline group in one molecule, the HOMO level is greater than that of Alq3. The HOMO of the compound of Formula 1 falls within the range of about 5.9 eV to 6.2 eV, and when a compound having such a HOMO level is used as the electron transporting layer material, it is generally possible to prevent holes from reaching the electron transporting layer. And, the LUMO of the compound of Formula 1 is in the range of about 2.9 eV to 3.2 eV. On the other hand, the compound of Formula 1 has a bandgap larger than that of the Alq3 material due to the above structure, which means that the emission wavelength of the light is shifted to a shorter wavelength. HOMO and LUMO value of the compound of Formula 1 is supported by the HOMO and LUMO value of the compounds of the present invention described in the preparation examples described below. For this reason, the compound of the present invention may be used as an electron injection or transport material in an organic light emitting device such as Alq3.                     

In addition, the compound of Formula 1 has a larger energy band gap than Alq3 as described above, and may be used together with a blue, green, or red light emitting dopant to serve as a light emitting host. For example, in the compound of Formula 1, blue dopant (perylene), green dopant C545t, or red dopant DPVBi (4,4'-bis (2.2-diphenylethyenyl) -1,1'-biphenyl When a dopant such as) is added, it may serve as a light emitting host as well as an electron injection or transport role.

On the other hand, the inventors have found that when the compounds of Formula 1 are used in the organic light emitting device, not only can greatly improve the brightness and efficiency of the organic light emitting device, but also increase the stability by lowering the driving voltage.

Compounds of Formula 1 are easily accessible in terms of their preparation method or raw material, and thus are easily commercialized.

In R1, R2 and R5 in Formula 1, examples of the aliphatic hydrocarbon having 1 to 24 carbon atoms include methyl, ethyl, propyl, isopropyl, butyl, tertiary-butyl, pentyl, hexyl and hep Although there exist a methyl group, a cyclopentyl group, a cyclohexyl group, etc., it is not limited to these.

In R1 to R4, L, and R5 in Formula 1, examples of the aromatic compound include, but are not limited to, phenyl, biphenyl, terphenyl, naphthalene, anthracene, perylene, pyrene, and the like.

In R1, R2 and L in Formula 1, examples of the heterocyclic compound include thiophene, furan, pyrrole, furyl, thienyl, pyridyl, quinolinyl, isoquinolinyl, and the like. It doesn't happen.

In L of Formula 1, examples of the unsaturated aliphatic hydrocarbon include a double or triple bond hydrocarbon, ethylene, acetylene, stilbene and the like, but is not limited thereto.

Examples of the aliphatic ring compound which may be formed by condensation of R1 and R2 in Formula 1 include a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, and the like, but are not limited thereto.

Examples of the aromatic ring compound which may be formed by condensation of R1 and R2 or R3 and R4 in Formula 1 may include substituents having the following structures, but are not limited thereto.

Examples of the heterocyclic compound which R1 and R2 may form by condensation in Chemical Formula 1 may include substituents having the following structures, but are not limited thereto.

In the present invention, one example of the compound of Formula 1 is a compound of Formula 2:

In Chemical Formula 2, R1 to R5 are the same as defined in Chemical Formula 1.

Another example of the compound of Formula 1 is a compound of Formula 3:

In Chemical Formula 3, R1 to R5 and m are as defined in Chemical Formula 1.

Another example of the compound of Formula 1 is a compound of Formula 4:                     

In Chemical Formula 4,

R1, R2, R5, L, n and m are as defined in Formula 1,

R6 is a hydrogen atom; Aliphatic hydrocarbons having 1 to 20 carbon atoms; Aromatic compounds; And an aromatic heterocyclic compound containing an element selected from the group consisting of nitrogen, oxygen and sulfur as ring members.

Another example of the compound of Formula 1 is a compound of Formula 5:

In Chemical Formula 5,

R1, R2, R5, L, n and m are as defined in Formula 1,

R7 and R8 each represent a hydrogen atom; Aliphatic hydrocarbons having 1 to 24 carbon atoms; Aromatic compounds; And an aromatic heterocyclic compound containing an element selected from the group consisting of nitrogen, oxygen, and sulfur as ring members.

Another example of the compound of Formula 1 is a compound of Formula 6:

In Chemical Formula 6,

R1, R2, L, n and m are as defined in Formula 1,

R6 is a hydrogen atom; Aliphatic hydrocarbons having 1 to 24 carbon atoms; Aromatic compounds; And an aromatic heterocyclic compound containing an element selected from the group consisting of nitrogen, oxygen and sulfur as ring members.

Another example of the compound of Formula 1 is a compound of Formula 7:

In Chemical Formula 7,                     

R1, R2, L, n and m are as defined in Formula 1,

R6 is a hydrogen atom; Aliphatic hydrocarbons having 1 to 24 carbon atoms; Aromatic compounds; It is selected from the group consisting of aromatic heterocyclic compounds containing as a ring member an element selected from the group consisting of nitrogen, oxygen and sulfur.

In R 6, R 7 and R 8 in Formulas 4 to 7, examples of the aliphatic hydrocarbon having 1 to 24 carbon atoms include methyl, ethyl, propyl, isopropyl, butyl, tertiary-butyl, pentyl and hexyl groups. , Heptyl group, cyclopentyl group, cyclohexyl group and the like, but are not limited thereto.

In R6, R7 and R8 in Formulas 4 to 7, examples of the aromatic compound include phenyl, biphenyl, terphenyl, naphthalene, anthracene, perylene, pyrene, and the like, but are not limited thereto.

In R6, R7 and R8 in Formulas 4 to 7, examples of the aromatic heterocyclic compound include thiophene, furan, pyrrole, furyl, thienyl, pyridyl, quinolinyl, isoquinolinyl, and the like. It is not limited only to.

Examples of specific compounds of the compound of Formula 1 include, but are not limited to, the compounds of Formulas 8 to 82 below.

[Formula 8]

[Formula 9]

[Formula 10]

[Formula 11]

[Formula 12]

[Formula 13]

[Formula 14]

[Formula 15]

[Formula 16]

[Formula 17]

[Formula 18]

[Formula 19]

[Formula 20]

[Formula 21]

[Formula 22]

[Formula 23]

[Formula 24]

[Formula 25]

[Formula 26]

[Formula 27]

[Formula 28]

[Formula 29]

[Formula 30]

[Formula 31]

[Formula 32]

[Formula 33]

[Formula 34]

[Formula 35]

[Formula 36]

[Formula 37]

[Formula 38]

[Formula 39]

[Formula 40]

[Formula 41]

[Formula 42]

[Formula 43]

[Formula 44]

[Formula 45]

[Formula 46]

[Formula 47]

[Formula 48]

[Formula 49]

[Formula 50]

[Formula 51]

[Formula 52]

[Formula 53]

[Formula 54]

[Formula 55]

[Formula 56]

[Formula 57]

[Formula 58]

[Formula 59]

[Formula 60]

[Formula 61]

[Formula 62]

[Formula 63]

[Formula 64]

[Formula 65]

[Formula 66]

[Formula 67]

[Formula 68]

[Formula 69]

[Formula 70]

[Formula 71]

[Formula 72]

[Formula 73]

[Formula 74]

[Formula 75]

[Formula 76]

[Formula 77]

[Formula 78]

[Formula 79]

[Formula 80]

[Formula 81]

[Formula 82]

The compound of Formula 1 may be prepared as follows.

As starting compounds, diamino benzene compounds represented by the following Chemical Formulas A, B, and C and diketo compounds represented by the following Chemical Formula D may be used.

In said formula, k is an integer of 1-2.

In the above formula, R1 and R2 are as defined in the formula (1).

First, by heating and stirring the diamino benzene compound of Formulas (A) -C together with the diketo compound of Formula (D) in an organic solvent such as acetic acid or ethanol, and then filtering the solid formed by the following formulas (A ', B' and C ') The same intermediate compound can be obtained.

[Formula A '] [Formula B'] [Formula C ']

There are various methods of introducing a substituent to the compound obtained in Formula 1 in the intermediate obtained as described above.

For example, the intermediate of Formula A 'is heated in polyphosphoric acid (PPA) to introduce a benzimidazole group, a diphenylimidazole group, a benzthiazole group, a benzoxazole group and the like directly to a carboxyl group (-CO ₂ H) of the intermediate. can do.

In addition, by using SOCl ₂ (thionyl chloride) or C ₂ O ₂ Cl ₂ (oxalyl chloride), etc., the carboxyl group (-CO ₂ H) of the intermediate of Formula A 'is converted to the carbonyl chloride (-COCl) group of Formula F The compound is then subjected to N-phenylphenylenediamine or derivative thereof, aminothiophenol or derivative thereof in a solvent such as NMP (N-methylpyrrolidine), tetrahydrofuran (THF) or pyridine, or By reacting with an aminophenol (aminophenol) or derivatives thereof, a compound in which a benzimidazole group, a benzthiazole group, a benzoxazole group and the like are introduced can be prepared.

In addition, the intermediate compound having a formyl group (formyl) of the formula b 'is N-phenyl-1,2-phenylenediamine (N-phenyl-1) in an organic solvent such as toluene, acetic acid, or NMP (N-methylpyrrolidine) , 2-phenylene diamine) or a derivative thereof may be reacted to prepare a benzimidazole compound. The diaryl benzimidazole compound may be prepared by reacting the compound of Formula b ′ with a diketo compound, aniline, or a derivative thereof in an acetic acid solvent. In addition, the benzthiazole compound may be prepared by reacting the compound of Formula b ′ with aminothionphenol or a derivative thereof in an organic solvent such as toluene, acetic acid or N-methylpyrrolidine (NMP). In addition, the compound of formula b 'and aminophenol (aminophenol) or derivatives thereof may be reacted in an organic solvent such as toluene, acetic acid or NMP (N-methylpyrrolidine) to prepare a benzthiazole compound or a benzoxazole compound. .

In addition, the compound of Formula 1 may be prepared using a palladium (Pd) catalyst as the intermediate C 'compound. For example, an ethylene group or an acetylene group can be easily introduced into the intermediate compound under a palladium (Pd) catalyst. In addition, boronic acids in which a heterocyclic group is substituted or converted to a heterocyclic group using a palladium (Pd) catalyst, such as a replaceable phenylboronic acid, a replaceable thiophenylboronic acid, Suzuki doupling of boronic acids, such as substitutable pyridylboronic acid, can be used to prepare compounds in which various substituents are introduced into L in the general formula (1).

One of ordinary skill in the art may alter the process for the preparation of the compounds of the invention exemplified above to produce compounds of the invention not exemplified above.

In addition, the present invention is an organic light emitting device comprising a first electrode, an organic material layer consisting of one or more layers and a second electrode in a stacked form, wherein at least one layer of the organic material layer comprises a compound of Formula 1 An organic light emitting device is provided.

The organic light emitting device of the present invention may be manufactured by materials and methods known in the art, except that at least one layer of the organic material layer includes the compound of the present invention, that is, the compound of Formula 1.

The organic material layer of the organic light emitting device of the present invention may have a single layer structure, but may have a multilayer structure in which two or more organic material layers are stacked. In the organic light emitting device having a multi-layer structure, the compound of Chemical Formula 1 may be included in the electron injection and transport layer and / or the light emitting layer, and may be included in the layer simultaneously performing electron injection, transport, and light emission. 1 illustrates the structure of an organic light emitting device according to the present invention, which includes a substrate 101, an anode 102, a hole injection layer 103, a hole transport layer 104, a light emitting layer 105, and an electron transport layer 106. And a cathode 107 in a stacked form sequentially. Specifically, it is as follows.

The substrate 101 is a support of an organic light emitting device, and a silicon wafer, a quartz or glass plate, a metal plate, a plastic film or a sheet may be used.

As the anode 102, a material having a large work function, such as metals such as aluminum, gold, silver, nickel, palladium, platinum, indium-tin oxide, indium-zinc oxide, may be used, and carbon black, polythiophene, Conductive polymers such as polypyrrole or polyaniline may also be used.

As the material of the hole injection layer 103, a material having a small ionization potential, high transparency to visible light, and excellent hole stability is preferable.

As the material of the hole transport layer 104, NPB, spiro-arylamine-based compound, perylene-arylamine-based compound, azacycloheptatriene compound, bis (diphenylvinylphenyl) anthracene, silicon germanium oxide compound, silicon-based aryl An amine compound etc. can be used.

The emission layer 105 may be formed of the compound of Formula 1. In the present invention, in addition to the light emitting layer material Alq3 in the case of green, Balq, DPVBi series, Spiro (Spiro) material, Spiro (DPpi), LiPBO, bis (diphenylvinylphenylvinyl) benzene, aluminum- Quinoline metal complexes, metal complexes of imidazole, thiazole and oxazole, and the like. In addition, a small amount of doped perylene and BczVBi (DSA amines) may be used to increase blue light emission efficiency. In the red case, a small amount of a material such as DCJTB may be doped into the green light emitting material. When the light emitting layer is formed using a process such as inkjet printing, roll coating, or spin coating, a polymer such as polyphenylene vinylene (PPV) -based polymer or poly fluorene may also be used.

The electron transport layer 106 may be formed using the compound of Formula 1. In the present invention, in addition to the electron transport layer, an aromatic compound such as tetraphenyl butadiene, a metal complex such as 8-hydroxy quinoline aluminum salt, a metal complex of 10-hydroxy benzo [h] quinoline, a cyclopentadiene derivative, bis styryl Benzene derivatives, perylene derivatives, p-phenylene derivatives, oxazole derivatives and the like can be used.

As the cathode 107, those used as the anode 102 material may be used, and a metal having a low work function is more preferable for efficient electron injection. In particular, a suitable metal such as tin, magnesium, indium, calcium, sodium, lithium, aluminum, silver, or a suitable alloy thereof can be used. In addition, an electrode having a two-layer structure such as lithium fluoride and aluminum, lithium oxide and aluminum, strontium oxide and aluminum having a thickness of 100 μm or less may also be used.

Hereinafter, the present invention will be described in more detail with reference to Examples. However, the following examples are merely to illustrate the invention, the scope of the present invention is not limited by the following examples.

Production Example

Preparation Example 1

(Preparation of Compound 15)

Benzyl (4.2 g, 19.9 mmol) was dispersed in 150 mL of acetic acid, and then 3,4-diaminobenzoic acid (3.0 g; 19.9 mmol) was added at 20 ° C. It was refluxed at 140 ° C. for 8 hours. The reaction was cooled to room temperature, diluted with 50 mL of ethanol and filtered. The filtrate was washed with ethanol and dried in vacuo to give the compound (5.7 g, yield 87%). 50 mL of thionyl chloride (SOCl 2) and 0.1 mL of DMF were added to the compound, and the mixture was refluxed at 90 ° C. for 5 hours, and then an excess of thionyl chloride was distilled off to obtain an intermediate such as Formula F in which benzoic acid was substituted with benzoyl chloride. Got it.

200 mL of dry THF was added to the benzoyl chloride compound thus prepared, and N-phenyl benzene diamine (3.20 g, 17.4 mmol) was slowly added at 0 ° C. Subsequently, 20 mL of pyridine was added thereto, followed by stirring at room temperature for 2 hours, followed by stirring at 50 ° C for 3 hours. The reaction was terminated by adding 100 mL of water at room temperature. The reaction was extracted with ethyl ether and dried over anhydrous magnesium. Subsequently, the dried product was vacuum dried under reduced pressure, dissolved in a small amount of ethyl acetate, and precipitated with ethanol, followed by filtration and drying to synthesize a carboxyamide compound. This was dissolved in 100 mL of dimethylacetamide and heated to reflux for 12 hours at 180 ~ 200 ℃. The solvent was removed under reduced pressure and then purified by column chromatography (developing solvent EA / HEX = 1/2) to obtain 6 g (yield 72%) of the compound of formula 15.

The mass spectrometry of this compound is as follows.

[M + H] + = 475

Tg; 99.5 ℃

Tm; 220.2 ° C

Preparation Example 2

(Preparation of Compound 16)

3.4 g of the compound of Formula 16 was prepared in the same manner as in Preparation Example 1, except that 5 g (16.1 mmol) of dinaphthyldiketone was reacted instead of benzyl.

The mass spectrometry results of this compound are as follows.                     

[M + H] + = 575

Preparation Example 3

(Preparation of Compound 18)

Phenanthronequinone (4.6 g, 22 mmol) was dispersed in 250 mL of acetic acid, and then 3,4-diaminobenzoic acid (3.4 g, 22 mmol) was added at 20 ° C, and refluxed at 140 ° C for 8 hours. The reaction was cooled to room temperature, diluted with 50 mL of ethanol and filtered. Washed with ethanol and dried in vacuo to give the compound (7g, 97.7% yield). 150 mL of thionyl chloride (SOCl ₂ ) and 0.1 mL of DMF were added to the compound, and the mixture was refluxed at 90 ° C. for 5 hours, and then an excess of thionyl chloride was distilled off to obtain an intermediate of formula F in which benzoic acid was substituted with benzoyl chloride. Got it.

100 mL of N-methylpyrrolidine (NMP) was added to the benzoyl chloride compound thus prepared, and N-phenyl benzene diamine (3.96 g, 21.4 mmol) was slowly added at 0 ° C. Subsequently, the reaction solution was stirred at 180 to 200 ° C. for 12 hours, and then the reaction solution was poured into 400 mL of water at room temperature and stirred to obtain a solid. This solid was washed with water and ethanol and dried in a vacuum oven to prepare 3.0 g of a compound of formula 18 (yield 29%).

The mass spectrometry results of this compound are as follows.

[M + H] + = 473                     

Tg; 115.8 ℃

Tm; 272.1 ℃

Preparation Example 4

Preparation of Compound (20)

Dibromo benzyl (7.2 g, 19.5 mmol) was dispersed in 150 mL of acetic acid, then 3,4-diaminobenzoic acid (3.0 g, 19.7 mmol) was added at 20 ° C, and refluxed at 140 ° C for 8 hours. The reaction was cooled to room temperature, diluted with 50 mL of ethanol and filtered. Washed with ethanol and dried in vacuo to give the compound (8.0 g, yield 84.6%). 100 mL of thionyl chloride (SOCl ₂ ) and 0.1 mL of DMF were added to the compound, and the mixture was refluxed at 90 ° C. for 5 hours, and then an excess of thionyl chloride was distilled off to obtain an intermediate such as Formula F in which benzoic acid was substituted with benzoyl chloride. Got it.

80 mL of N-methylpyrrolidine (NMP) was added to the benzoyl chloride compound thus prepared, and N-phenyl benzene diamine (2.28 g, 12.8 mmol) was slowly added at 0 ° C. Subsequently, the reaction solution was stirred at 180 to 200 ° C. for 12 hours and then poured into 400 mL of water at room temperature and stirred to obtain a solid. This solid was washed with water and ethanol and then dried in a vacuum oven. 100 mL of ethyl acetate was added to the dried compound, which was stirred at 80 ° C., cooled to room temperature and filtered to prepare 2.1 g (yield 20%) of a dibromo-connected intermediate. No more recovery in the filtrate.

2.1 g (3.3 mmol) of the intermediate prepared above were stirred with 80 mL of Pd (PPh ₃ ) _4, 0.038 g (0.033 mmol), 2 MK ₂ CO _{3 in} 40 mL of THF at 80 ° C. for 8 hours. After cooling the reaction temperature to room temperature, excess THF was removed by vacuum distillation, and then 200 mL of ethanol was added to the reaction mixture and stirred to obtain a compound of formula 20 as a solid.

The mass spectrometry results of this compound are as follows.

[M + H] + = 727

Tg; 127.3 ℃

Tm; 246.4 ℃

Preparation Example 5

(Preparation of Compound 22)

Except for reacting 6.0 g (25.1 mmol) of dimethylbenzyl instead of benzyl, 7.6 g of a compound of formula 22 was prepared in the same manner as in Preparation Example 1 in a yield of 65%.                     

The mass spectrometry results of this compound are as follows.

[M + H] + = 503

Preparation Example 6

(Preparation of Compound 34)

1.2 g of a compound of Chemical Formula 34 (yield 14%) in the same manner as in Preparation Example 3, except that 3.4 g (9.9 mmol) of 1,4-bisbenzil was reacted instead of phenanthronequinone. ) Was prepared.

The mass spectrometry results of this compound are as follows.

[M + H] + = 871

Preparation Example 7

(Preparation of Compound 35)

Instead of phenanthronequinone, 1,1 '-(4,4'-biphenylyl) bis (2-phenyl-1,2-ethanedione) [1,1'-(4,4'-biphenyldiyl) bis ( 2-phenyl-1,2-ethanedione)] 0.6 g of the compound of Formula 35 was prepared in the same manner as in Preparation Example 3, except that 1.1 g (2.6 mmol) was reacted.

The mass spectrometry results of this compound are as follows.

[M + H] + = 947

Preparation Example 8

(Preparation of Compound 57)

2.6 g (12.4 mmol) of benzyl was reacted with 1,2-diamino-3,4-dibromobenzene to synthesize 5.2 g (yield; 95%) of the dibromo quinoxaline compound. This was then reacted with 4.42 g (29.5 mmol) of 4-formylphenylboronic acid to prepare 4.4 g of an intermediate into which the formylphenyl group was introduced in a yield of 75.4%. 3.6 g (19.6 mmol) of N-phenyldiaminobenzene was reacted with this compound according to the method of Preparation Example 3 to obtain 2.7 g (36% yield) of the compound of Formula 57.

The mass spectrometry results of this compound are as follows.

[M + H] + = 819

Preparation Example 9

Preparation of Compound 61

Except for reacting 3.1 g (10 mmol) of the hexaketone octahydrate compound instead of phenanthronequinone, 2.4 g of the compound of formula 61 was prepared in the same manner as in Preparation Example 3 in a yield of 24%.

The mass spectrometry results of this compound are as follows.

[M + H] + = 961

HOMO and LUMO values of the compounds prepared in Preparation Example are shown in Table 1 below.

compound HOMO (eV) LUMO (eV) Formula 15 5.99 3.03 Formula 18 5.97 3.13 Formula 20 5.96 3.12 Formula 34 5.94 3.10

Example

Example 1

A glass substrate coated with a thin film of ITO (indium tin oxide) at a thickness of 1500 Å was placed in distilled water in which detergent was dissolved and ultrasonically cleaned. At this time, a product of Fischer Co. was used as a detergent, and distilled water filtered secondly as a filter of Millipore Co., Ltd. was used as distilled water. After washing ITO for 30 minutes, the ultrasonic cleaning was repeated twice with distilled water for 10 minutes. After the distilled water was washed, ultrasonic washing with a solvent of isopropyl alcohol, acetone, methanol, dried and transported to a plasma cleaner. In addition, the substrate was cleaned for 5 minutes using an oxygen plasma, and then the substrate was transferred to a vacuum evaporator.

Hexanitrile hexaazatriphenylene was thermally vacuum deposited to a thickness of 500 kPa on the prepared ITO transparent electrode to form a hole injection layer. NPB (400 kPa), which is a material for transporting holes, was vacuum deposited thereon, and the Alq3 compound was vacuum deposited to a thickness of 300 kPa as a light emitting layer. The compound of Chemical Formula 15 prepared in Preparation Example 1 was vacuum deposited to a thickness of 200 kPa on the light emitting layer to form an electron injection and transport layer. Lithium fluoride (LiF) and aluminum having a thickness of 2500 kPa were deposited on the electron injection and transport layer sequentially to form a cathode.

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

As a result of applying a forward electric field of 5V to the organic light emitting device, green light corresponding to x = 0.33, y = 0.56 was observed based on 1931 CIE color coordinate at a current density of 50 mA / cm 2, and forward direction of 6.0 V As a result of applying the electric field, green light of 3.6 cd / A was observed at a current density of 100 mA / cm 2.

Example 2

An organic light emitting device was manufactured in the same manner as in Example 1, except that an electron injection and transport layer was formed of a compound of Formula 18 instead of a compound of Formula 15.

When a forward electric field of 5.5 V was applied to the organic light emitting device manufactured above, green light corresponding to x = 0.32 and y = 0.55 was observed based on 1931 CIE color coordinate at a current density of 50 mA / cm 2, and a forward direction of 7.4 V. As a result of applying the electric field, green light of 1.78 cd / A was observed at a current density of 100 mA / cm 2.

Example 3

An organic light-emitting device was manufactured in the same manner as in Example 1, except that an electron injection and transport layer was formed of a compound of Formula 20 instead of a compound of Formula 15.

As a result of applying a forward electric field of 5.5 V to the organic light emitting device manufactured above, green light corresponding to x = 0.33 and y = 0.55 was observed based on 1931 CIE color coordinate at a current density of 50 mA / cm 2, and a forward direction of 6.9 V. As a result of applying the electric field, green light of 3.1 cd / A was observed at a current density of 100 mA / cm 2.

Example 4

An organic light emitting device was manufactured in the same manner as in Example 1, except that an electron injection and transport layer was formed of a compound of Formula 34 instead of a compound of Formula 15.

As a result of applying a forward electric field of 5.5 V to the organic light emitting device manufactured above, green corresponding to x = 0.35 and y = 0.55 based on 1931 CIE color coordinate at a current density of 50 mA / cm 2. Light was observed, and a green light of 2.6 cd / A was observed at a current density of 100 mA / cm 2 by applying a forward electric field of 8.4V.

Comparative Example 1

An organic light-emitting device was manufactured in the same manner as in Example 1, except that the Alq3 compound was vacuum deposited to a thickness of 500 GPa using a light emitting layer and an electron injection and transport layer.

When a forward electric field of 5.5 V was applied to the organic light emitting device, green light corresponding to x = 0.35 and y = 0.55 was observed based on 1931 CIE color coordinate at a current density of 50 mA / cm 2, and 6.5 V of As a result of the forward electric field, green light of 3.2 cd / A was observed at a current density of 100 mA / cm 2.

It can be seen from the above examples and comparative examples that the compound of the present invention plays a role of electron injection and transport in the organic light emitting device such as Alq3.

The compound of the present invention is a novel compound, which may serve as electron injection and / or transport in an organic light emitting device, and may also serve as a light emitting host with an appropriate dopant. By applying the compound of the present invention to an organic light emitting device, it is possible to achieve excellent effects in terms of efficiency, driving voltage, and stability of the organic light emitting device.

Claims (6)

A compound of formula [Formula 1]

In Chemical Formula 1,  R1 and R2 are each or simultaneously hydrogen atoms; Alicyclic hydrocarbons having 1 to 24 carbon atoms, aromatic compounds, and heterocyclic compounds containing an element selected from the group consisting of nitrogen, oxygen and sulfur as ring members; R1 and R2 together form a condensed ring selected from the group consisting of aliphatic ring compounds having 5 to 32 carbon atoms, aromatic ring compounds, and heterocyclic compounds containing an element selected from the group consisting of nitrogen, oxygen and sulfur as ring members; and; R3 and R4 are each aromatic compounds, or R3 and R4 are condensed to form an aromatic ring compound; L is an aromatic compound; Heterocyclic compounds containing an element selected from the group consisting of nitrogen, oxygen and sulfur as ring members; And it is selected from the group consisting of C2-C32 unsaturated aliphatic hydrocarbons, X is selected from the group consisting of oxygen, sulfur and NR 5, wherein R 5 is selected from the group consisting of aromatic compounds and aliphatic hydrocarbons having 1 to 24 carbon atoms, n is 0 or 1, m is 1 or 2. The compound of claim 1, wherein the compound of Formula 1 is selected from the group consisting of compounds of Formulas 2 to 7 [Formula 2]

In Chemical Formula 2, R1 to R5 are the same as defined in Formula 1 above; [Formula 3]

In Chemical Formula 3, R1 to R5 and m are as defined in Formula 1 above; [Formula 4]

In Chemical Formula 4, R1, R2, R5, L, n and m are as defined in Formula 1, R6 is a hydrogen atom; Aliphatic hydrocarbons having 1 to 24 carbon atoms; Aromatic compounds; And it is selected from the group consisting of an aromatic heterocyclic compound containing as a ring member an element selected from the group consisting of nitrogen, oxygen and sulfur; [Formula 5]

In Chemical Formula 5, R1, R2, R5, L, n and m are as defined in Formula 1, R7 and R8 each represent a hydrogen atom; Aliphatic hydrocarbons having 1 to 24 carbon atoms; Aromatic compounds; Selected from the group consisting of aromatic heterocyclic compounds containing as a ring member an element selected from the group consisting of nitrogen, oxygen and sulfur; [Formula 6]

In Chemical Formula 6, R1, R2, L, n and m are as defined in Formula 1, R6 is a hydrogen atom; Aliphatic hydrocarbons having 1 to 24 carbon atoms; Aromatic compounds; It is selected from the group consisting of aromatic heterocyclic compounds containing as a ring member an element selected from the group consisting of nitrogen, oxygen and sulfur; [Formula 7]

In Chemical Formula 7, R1, R2, L, n and m are as defined in Formula 1, R6 is a hydrogen atom; Aliphatic hydrocarbons having 1 to 24 carbon atoms; Aromatic compounds; It is selected from the group consisting of aromatic heterocyclic compounds containing as a ring member an element selected from the group consisting of nitrogen, oxygen and sulfur. In an organic light emitting device comprising a first electrode, an organic material layer consisting of one or more layers and a second electrode in a sequentially stacked form, at least one layer of the organic material layer comprises the compound of claim 1 or claim 2 Organic light emitting device. The organic light emitting device of claim 3, wherein the organic material layer includes an electron injection and transport layer, and the electron injection and transport layer includes the compound of claim 1. The organic light emitting device of claim 3, wherein the organic material layer comprises a light emitting layer, and the light emitting layer comprises the compound of claim 1. The organic light-emitting device of claim 3, wherein the organic material layer includes a layer for simultaneously injecting, transporting, and emitting light, and the layer comprises the compound of claim 1.

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