KR20070063853A - A fluorene-based compound, an organic light emitting device comprising an organic layer comprising the same and a method for preparing the organic light emitting device - Google Patents

Abstract

Provided is a fluorene-based compound, which has improved film formability, and thus allows formation of an organic layer useful for an organic light emitting device, having a uniform thickness and causing no crystallization via a heat transfer process. The fluorene-based compound is represented by the following chemical formula 1. In chemical formula 1, each of R1-R6 independently represents H, a substituted or non-substituted C1-C20 alkyl, a substituted or non-substituted C6-C30 aryl; each of R7 and R8 independently represents H, a halogen atom, CN, OH, NH2, a substituted or non-substituted C1-C20 alkyl, a substituted or non-substituted C1-C20 alkoxy, a substituted or non-substituted C6-C30 aryl, a substituted or non-substituted C2-C30 heteroaryl, a substituted or non-substituted C5-C20 cycloalkyl, or a substituted or non-substituted C5-C30 heterocycloalkyl; each of A and B independently represents H, a substituted or non-substituted linear, branched or cyclic C1-C20 alkyl, or a substituted or non-substituted C6-C30 aryl; each of n1 and n2 independently represents 0 or an integer of 1-3; and n is an integer of 1-5, wherein when n is 2, R7s and R8s in each fluorene group are the same or different from each other, and As and Bs in each fluorene group are the same or different.

Description

Fluorene-based compound, an organic light emitting device comprising an organic layer comprising the same and a method for preparing the organic light emitting device}

1A to 1C are cross-sectional views briefly illustrating a structure of an organic light emitting diode according to the present invention.

2 is a TGA graph of an embodiment of a fluorene-based compound according to the present invention,

Figure 3 is a graph showing the UV absorption spectrum and PL spectrum of the embodiment of the fluorene-based compound according to the present invention.

The present invention relates to a fluorene-based compound, an organic light emitting device having an organic film including the compound, and a method of manufacturing the organic light emitting device, and more particularly, to improve a film forming ability of a fluorene moiety. The present invention relates to a fluorene compound having a side chain branch, an organic light emitting device having an organic film containing the fluorene compound, and a method of manufacturing the organic light emitting device. By using the fluorene-based compound according to the present invention, an organic film having a uniform film thickness and no crystallization can be obtained using a heat transfer method including a wet process or a wet process.

A light emitting device is a self-luminous device, and has a wide viewing angle, excellent contrast, and fast response time. The light emitting device includes an inorganic light emitting device using an inorganic compound and an organic light emitting device using an organic compound (OLED) in the light emitting layer, and the organic light emitting device has higher luminance and driving than the inorganic light emitting device. Much research has been conducted in that the voltage and response speed characteristics are excellent and multicoloring is possible. For example, US Pat. No. 3,873,311 discloses 1,4-bis [2- [4-N, N-di (p-tolyl) amino] phenyl vinyl that is soluble in toluene as a compound that can be used in organic light emitting devices. ] Benzene (BTAPVB) is disclosed.

Organic light emitting devices may be classified into small molecule OLEDs (SMOLED) and polymer OLEDs (PLED) according to the molecular weight of the light emitting layer.

The organic film including at least the light emitting layer of the low molecular OLED often has a multilayer structure further including a hole injection layer, a hole transport layer, an electron transport layer and / or an electron injection layer so that holes and electrons can be efficiently moved. In most cases, the layers may be formed using a vacuum thermal evaporation method or a vapor deposition method. At this time, the use efficiency of the materials forming the layers is relatively low, which causes manufacturing cost. In addition, the development of deposition equipment for large screen applications is not yet satisfactory.

On the contrary, the polymer OLED has higher mechanical strength and thermal stability of the organic layer interposed between the first electrode and the second electrode than the low molecular OLED, and has a low driving voltage and various light emission colors according to various molecular structures of the light emitting polymer. Has the advantage that it can. The organic film of the polymer OLED may be formed by using a wet process such as spin casting, ink jet printing, spray printing, or the like, in which a solution of the light emitting polymer is dissolved in a suitable organic solvent. . The wet process is advantageous for the application of a large screen and the manufacturing cost is low, and research on the method of forming an organic layer using the wet process has been actively conducted.

However, when the organic film is formed by using a wet process, the film characteristics may be poor, such as an uneven film thickness of the organic film or crystallization of some or more of the organic films. Thus, there is a need for the development of new materials suitable for forming films using wet processes.

In order to solve the problems of the prior art, the present invention provides a fluorene-based compound having an improved film-forming ability to be suitable for the heat transfer method including a wet process and a wet process, an organic light emitting device including an organic film containing the fluorene-based compound and It is an object to provide a method for producing the organic light emitting device.

In order to achieve the above object of the present invention, a first aspect of the present invention provides a fluorene compound represented by the following formula (1)

<Formula 1>

In Formula 1,

R ₁ to R ₆ are each independently of the other hydrogen; C ₁ -C ₂₀ alkyl group unsubstituted or substituted with a halogen atom, cyano group, hydroxyl group or amino group; Or a C ₆ -C ₃₀ aryl group which is unsubstituted or substituted with a halogen atom, cyano group, hydroxyl group or amino group;

R ₇ and R ₈ Independently of each other, hydrogen; Halogen atom; Cyano group; Hydroxyl group; Amino group; C ₁ -C ₂₀ alkyl group unsubstituted or substituted with a halogen atom, cyano group, hydroxyl group, amino group or C ₆ -C ₃₀ aryl group; C ₁ -C ₂₀ alkoxy group unsubstituted or substituted with a halogen atom, cyano group, hydroxyl group or amino group; C ₆ -C ₃₀ aryl group unsubstituted or substituted with a halogen atom, cyano group, hydroxyl group or amino group; C ₂ -C ₃₀ heteroaryl group unsubstituted or substituted with a halogen atom, cyano group, hydroxyl group or amino group; C ₅ -C ₂₀ cycloalkyl group unsubstituted or substituted with a halogen atom, cyano group, hydroxyl group or amino group; Or a C ₅ -C ₃₀ heterocycloalkyl group which is unsubstituted or substituted with a halogen atom, cyano group, hydroxyl group or amino group;

A and B are, independently from each other, hydrogen; Linear, branched or cyclic C ₁ -C ₂₀ alkyl groups which are unsubstituted or substituted with halogen atoms, cyano groups, hydroxyl groups, amino groups or C ₆ -C ₃₀ aryl groups; Or a C ₆ -C ₃₀ aryl group which is unsubstituted or substituted with a halogen atom, cyano group, hydroxyl group or amino group;

n1 and n2, independently of each other, are 0 or an integer of 1 to 3;

n is an integer from 1 to 5;

When n is 2 or more, R ₇ and R ₈ substituted in each fluorene may be the same or different from each other, and A and B substituted in each fluorene may be the same or different from each other.

In order to achieve the another object of the present invention, the second aspect of the present invention provides an organic light emitting device comprising an organic film containing a fluorene-based compound represented by the formula (1).

In order to achieve another object of the present invention, a third aspect of the present invention comprises the step of forming a first electrode on the substrate, and the fluorene-based compound represented by the formula (1) on the first electrode It provides a method of manufacturing an organic light-emitting device comprising forming an organic film and forming a second electrode on the organic film.

The fluorene-based compound represented by Chemical Formula 1 may have excellent film forming ability when forming a film using a heat transfer method including a wet process and / or a wet process.

Hereinafter, the present invention will be described in more detail.

The fluorene-based compound according to the present invention is represented by the formula (1). In the formula (1), the silyl group substituted with terminal fluorene improves the film-forming ability of the fluorene-based compound represented by the formula (1), particularly in the case of using a thermal transfer method including a wet process and / or a wet process. It plays a role. This is because the film thickness can be kept uniform during film formation by the silyl group, and crystallization is prevented. In addition, by controlling the substituents of A or B, the color purity can be controlled by controlling the packing of the molecule together with the steric hindrance.

R ₁ to R ₆ are Independently of each other, hydrogen; C ₁ -C ₂₀ alkyl group unsubstituted or substituted with a halogen atom, cyano group, hydroxyl group or amino group; Or a C ₆ -C ₃₀ aryl group which is unsubstituted or substituted with a halogen atom, cyano group, hydroxyl group or amino group.

R ₇ and R ₈ are Independently of each other, hydrogen; Halogen atom; Cyano group; Hydroxyl group; Amino group; C ₁ -C ₂₀ alkyl group unsubstituted or substituted with a halogen atom, cyano group, hydroxyl group, amino group or C ₆ -C ₃₀ aryl group; C ₁ -C ₂₀ alkoxy group unsubstituted or substituted with a halogen atom, cyano group, hydroxyl group or amino group; C ₆ -C ₃₀ aryl group unsubstituted or substituted with a halogen atom, cyano group, hydroxyl group or amino group; C ₂ -C ₃₀ heteroaryl group unsubstituted or substituted with a halogen atom, cyano group, hydroxyl group or amino group; C ₅ -C ₂₀ cycloalkyl group unsubstituted or substituted with a halogen atom, cyano group, hydroxyl group or amino group; Or a C ₅ -C ₃₀ heterocycloalkyl group which is unsubstituted or substituted with a halogen atom, cyano group, hydroxyl group or amino group, and the hetero atoms included in the C ₂ -C ₃₀ heteroaryl group are N, O, S and P It may be one or more of.

A or B is independently of each other, hydrogen; Linear, branched or cyclic C ₁ -C ₂₀ alkyl groups which are unsubstituted or substituted with halogen atoms, cyano groups, hydroxyl groups, amino groups or C ₆ -C ₃₀ aryl groups; Or a C ₆ -C ₃₀ aryl group which is unsubstituted or substituted with a halogen atom, cyano group, hydroxyl group or amino group. More preferably, A and B are independently of each other, hydrogen; Or a linear, branched or cyclic C ₁ -C ₂₀ alkyl group which is unsubstituted or substituted with a halogen atom, cyano group, hydroxyl group, amino group or C ₆ -C ₃₀ aryl group.

In Formula 1, n1 and n2 are The number of substituents R ₇ and R ₈ is shown, and each independently represents an integer of 0 or 1-3.

When n1 and n2 are two or more, a plurality of R ₇ may be the same as or different from each other, and of course, the same applies to R ₈ .

On the other hand, n is an integer of 1 to 5 as the number of fluorene repeat units. In this case, when n is 2 or more, R ₇ and R ₈ substituted in each fluorene repeat unit may be the same or different from each other. In addition, when n is 2 or more, A and B substituted in each fluorene repeat unit may also be the same or different from each other.

In one embodiment according to the present invention, the fluorene-based compound may have the following Formula 2, 3 or 4, but is not limited thereto.

<Formula 2>

<Formula 3>

<Formula 4>

<Formula 5>

The fluorene-based compound can be synthesized using a conventional organic compound production method.

The fluorene-based compound according to the present invention as described above can be applied to the organic light emitting device. An organic light emitting device according to the present invention comprises a first electrode; Second electrode; And at least one layer of an organic film between the first electrode and the second electrode, wherein the organic film may include a fluorene-based compound represented by Formula 1 as described above. More specifically, the organic layer may be a light emitting layer or a hole transport layer.

The organic film of the organic light emitting device according to the present invention may further include at least one layer selected from the group consisting of a hole injection layer, a hole transport layer, an electron blocking layer, a hole blocking layer, an electron transport layer and an electron injection layer.

More specifically, an embodiment of the organic light emitting device according to the present invention refers to Figures 1a, 1b and 1c. The organic light emitting device of FIG. 1A has a structure consisting of a first electrode / hole injection layer / light emitting layer / electron transport layer / electron injection layer / second electrode, and the organic light emitting device of FIG. 1B includes a first electrode / hole injection layer / hole transport layer. / Light emitting layer / electron transport layer / electron injection layer / second electrode. In addition, the organic light emitting device of FIG. 1C has a structure of a first electrode / hole injection layer / hole transport layer / light emitting layer / hole blocking layer / electron transport layer / electron injection layer / second electrode. At this time, the light emitting layer may include a fluorene-based compound according to the present invention.

Hereinafter, a method of manufacturing an organic light emitting diode according to the present invention will be described with reference to the organic light emitting diode illustrated in FIG. 1C.

First, a first electrode material having a high work function on the substrate is formed by a deposition method or a sputtering method to form a first electrode. The first electrode may be an anode or a cathode, and preferably may be an anode. Herein, a substrate used in a conventional organic light emitting device is used, and a glass substrate or a transparent plastic substrate having excellent mechanical strength, thermal stability, transparency, surface smoothness, ease of handling, and waterproofness is preferable. Indium tin oxide (ITO), indium zinc oxide (IZO), tin oxide (SnO ₂ ), zinc oxide (ZnO), and the like, which are transparent and have excellent conductivity, are used as the material for the first electrode.

Next, the hole injection layer HIL may be formed on the first electrode by using various known methods such as vacuum deposition, spin coating, casting, and LB.

In the case of forming the hole injection layer by vacuum deposition, the deposition conditions vary depending on the compound used as the material of the hole injection layer, the structure and thermal properties of the hole injection layer, and the like. It is preferable that a vacuum degree of 10 ^-8 to 10 ^-3 torr, a deposition rate of 0.01 to 100 mW / sec, and a film thickness are usually appropriately selected in the range of 10 mV to 5 m.

In the case of forming the hole injection layer by spin coating, the coating conditions vary depending on the compound used as the material of the hole injection layer, the structure and the thermal properties of the desired hole injection layer, but the coating speed is about 2000 rpm to 5000 rpm. , The heat treatment temperature for removing the solvent after coating is preferably selected in the temperature range of about 80 ℃ to 200 ℃.

The hole injection layer material is not particularly limited, and for example, a phthalocyanine compound such as copper phthalocyanine disclosed in U.S. Patent No. 4,356,429 or a starburst amine derivative described in Advanced Material, 6, p.677 (1994). Residual TCTA, m-MTDATA, m-MTDAPB, Pani / DBSA (Polyaniline / Dodecylbenzenesulfonic acid: polyaniline / dodecylbenzenesulfonic acid) or PEDOT / PSS (Poly (3,4-ethylenedioxythiophene) / Poly () 4-styrenesulfonate): poly (3,4-ethylenedioxythiophene) / poly (4-styrenesulfonate)), Pani / CSA (Polyaniline / Camphor sulfonic acid: polyaniline / camphorsulfonic acid) or PANI / PSS (Polyaniline) / Poly (4-styrenesulfonate): polyaniline) / poly (4-styrenesulfonate)) and the like can be used.

          PEDOT / PSS

The hole injection layer may have a thickness of about 100 kPa to 10000 kPa, preferably 100 kPa to 1000 kPa. This is because when the thickness of the hole injection layer is less than 100 kV, the hole injection characteristic may be lowered, and when the thickness of the hole injection layer exceeds 10000 kV, the driving voltage may increase.

Next, a hole transport layer (HTL) may be formed on the hole injection layer by using various methods such as vacuum deposition, spin coating, cast, and LB. When the hole transport layer is formed by the vacuum deposition method or the spinning method, the deposition conditions and the coating conditions vary depending on the compound used, but are generally selected from a range of conditions almost the same as that of the formation of the hole injection layer.

The hole transport layer material is not particularly limited and may be selected from any of known ones used in the hole transport layer. For example, carbazole derivatives such as N-phenylcarbazole and polyvinylcarbazole, N, N'-bis (3-methylphenyl) -N, N'-diphenyl- [1,1-biphenyl]- Conventional amine derivatives having aromatic condensed rings such as 4,4'-diamine (TPD), N, N'-di (naphthalen-1-yl) -N, N'-diphenyl benzidine (α-NPD), and the like Used.

The hole transport layer may have a thickness of about 50 kPa to 1000 kPa, preferably 100 kPa to 600 kPa. This is because when the thickness of the hole transport layer is less than 50 kV, hole transport characteristics may be degraded, and when the thickness of the hole transport layer exceeds 1000 kW, the driving voltage may increase.

Next, the light emitting layer EML may be formed on the hole transport layer by using various known methods such as vacuum deposition, spin coating, casting, and LB on the first electrode. When the light emitting layer is formed by the vacuum deposition method or the spin coating method, the deposition conditions vary depending on the compound used, but are generally selected from the ranges of conditions substantially the same as those of forming the hole injection layer.

As described above, the emission layer may include a fluorene-based compound represented by Formula 1 according to the present invention. At this time, the fluorene-based compound may be used alone or in combination with a suitable known host material. For host materials, for example, Alq ₃ or CBP (4,4'-N, N'-dicarbazole-biphenyl), PVK (poly (n-vinylcarbazole)), TFB (2,5,2 ', 5'-tetra (9,9'-dihexylfluorenyl) biphenyl): 2,5,2', 5'-tetra (9,9'-dihexylfluorenyl) biphenyl), 3-tert-butyl- 9,10-di (naphth-2-yl) anthracene (3-tert-butyl-9,10-di (naphth-2-yl) anthracene) and the like can be used.

3-tert-butyl-9,10-di (naphth-2-yl) anthracene

The organic film forming step including the fluorene-based compound may be particularly performed using a wet process.

In the present specification, the term "wet process" refers to the formation of a film containing a predetermined compound on a predetermined substrate, wherein the organic film is coated or printed on the substrate by using various known methods. It points to the process of forming. That is, when the organic film containing the fluorene-based compound is formed on a predetermined substrate by using a "wet process", the solution containing the fluorene-based compound is coated on the substrate by various known methods. Alternatively, the organic film including the fluorene-based compound may be formed by printing. Such wet processes include all known methods that satisfy the concept of wet processes as described above. For example, spin coating, casting, inkjet printing, contact printing, etc. may be included, but are not limited thereto.

On the other hand, in addition to the fluorene-based compound according to the present invention as a light emitting layer forming material it can be used a variety of known dopants. For example, as the fluorescent dopant, IDE102, IDE105, and C545T, available from Hayashibara, may be used. PPy) ₃ (PPy = 2-phenylpyridine), F2Irpic, a blue phosphorescent dopant, and the like can be used.

Doping concentration is not particularly limited, but the content of the dopant is generally 0.01 to 15 parts by weight based on 100 parts by weight of the host.

The thickness of the light emitting layer may be about 10 kPa to 1000 kPa, preferably 10 kPa to 600 kPa. This is because, when the thickness of the light emitting layer is less than 10 kW, the light emission characteristics may be degraded.

When used with a phosphorescent dopant in the light emitting layer, in order to prevent the triplet excitons or holes from diffusing into the electron transport layer, holes such as vacuum deposition, spin coating, cast, LB, etc. are formed on the hole transport layer. The blocking layer HBL may be formed. In the case of forming the hole blocking layer by vacuum deposition or spin coating, the conditions vary depending on the compound used, but are generally selected from the ranges of conditions almost the same as that of forming the hole injection layer. Known hole blocking materials that can be used include, for example, oxadiazole derivatives, triazole derivatives, phenanthroline derivatives, hole blocking materials described in JP 11-329734 (A1), BCP and the like.

The hole blocking layer may have a thickness of about 50 kPa to 1000 kPa, preferably 100 kPa to 300 kPa. This is because when the thickness of the hole blocking layer is less than 50 kV, the hole blocking property may be deteriorated. When the thickness of the hole blocking layer is more than 1000 kV, the driving voltage may increase.

Next, the electron transport layer (ETL) is formed using various methods such as vacuum deposition, spin coating, and casting. When the electron transport layer is formed by the vacuum deposition method or the spin coating method, the conditions vary depending on the compound used, but are generally selected from the ranges of conditions almost the same as that of the formation of the hole injection layer. The electron transport layer material functions to stably transport electrons injected from an electron injection electrode (Cathode), and known materials such as quinoline derivatives, especially tris (8-quinolinorate) aluminum (Alq ₃ ), TAZ, and BAlq. You can also use

The electron transport layer may have a thickness of about 10 kPa to 1000 kPa, preferably 10 kPa to 500 kPa. This is because, when the thickness of the electron transport layer is less than 10 kW, the electron transport characteristic may be degraded, and when the thickness of the electron transport layer exceeds 1000 kW, the driving voltage may increase.

In addition, an electron injection layer (EIL), which is a material having a function of facilitating injection of electrons from the cathode, may be stacked on the electron transport layer, which does not particularly limit the material.

As the electron injection layer, any material known as an electron injection layer forming material such as LiF, NaCl, CsF, Li ₂ O, BaO, or the like can be used. The deposition conditions of the electron injection layer vary depending on the compound used, but are generally selected from the range of conditions almost the same as the formation of the hole injection layer.

The electron injection layer may have a thickness of about 1 kPa to 100 kPa, preferably 1 kPa to 50 kPa. This is because, when the thickness of the electron injection layer is less than 1 kW, the electron injection characteristic may be deteriorated, and when the thickness of the electron injection layer exceeds 100 kW, the driving voltage may increase.

Finally, the second electrode may be formed on the electron injection layer by using a vacuum deposition method or a sputtering method. The second electrode may be a cathode or an anode, and preferably may be a cathode. As the metal for forming the second electrode, a metal, an alloy, an electrically conductive compound having a low work function, and a mixture thereof may be used. Specific examples include lithium (Li), magnesium (Mg), aluminum (Al), aluminum-lithium (Al-Li), calcium (Ca), magnesium-indium (Mg-In), magnesium-silver (Mg-Ag), and the like. Can be mentioned. In addition, a transmissive cathode using ITO and IZO may be used to obtain the front light emitting device.

The organic light emitting device of the present invention includes a first electrode, a hole injection layer (HIL), a hole transport layer (HTL), a light emitting layer (EML), a hole blocking layer (HBL), an electron transport layer (ETL), an electron injection shown in FIG. In addition to the layer EIL, the organic light emitting device having the second electrode structure, as well as an organic light emitting device having various structures (for example, the organic light emitting device shown in FIG. to be.

Hereinafter, the present invention will be described in detail through synthesis examples and examples, but the present invention is not limited to the following synthesis examples and examples.

Synthesis Example  One  Synthesis of Compound Having Chemical Formula 2 (hereinafter referred to as "Compound 2")

First, Intermediate A was prepared according to Scheme 2a:

A-1 A-2 A-3

A-4 intermediate A

Synthesis of Intermediate A

A-1 (2 g, 6.17 mmol), t-BuOK (1.7 g, 15.42 mmol) and 2-ethylhexyl bromide were dissolved in 10 mL of DMF. The mixture was stirred at 40 ° C. for 18 hours, then extracted with ether and dried over magnesium sulfate, then 2-ethylhexyl bromide was distilled off in vacuo. The reaction mixture obtained therefrom was purified by column chromatography using n-hexane: methylene chloride (9: 1) as a developing solvent. As a result, 2.7 g (yield 80%) of A-2 was obtained as a white solid. The A-2 was confirmed by using NMR, and it was as follows:

¹ H NMR (δ in CDCl ₃ ): 0.4-0.6 (m, 9H), 0.62-0.98 (m, 27H). 1.87-1.98 (d, 4H, J = 9.5 Hz), 7.42-7.58 (m, 6H).

A-2 (11.1 g, 23.9 mmol) was dissolved in 3 mL of anhydrous THF under nitrogen atmosphere and cooled to -78 ° C. To this mixture was added 9.8 mL (24.5 mmol) of n-butyllithium dropwise for 30 minutes and stirred for 1 hour. Then 3.4 mL (26.8 mmol) of Me ₃ SiCl were added at −78 ° C. and stirred overnight. The reaction mixture obtained from this was extracted with ether, dried over magnesium sulfate and purified using column chromatography. As a result, 11.5 g (95% yield) of A-3 was obtained as a white solid. The A-3 was confirmed by using NMR, which was as follows:

¹ H NMR (δ in CDCl ₃ ): 0.3-0.39 (m, 9H), 0.4-0.59 (m, 9H), 0.61-0.98 (m, 26H), 1.82-2.1 (m, 4H), 7.42-7.71 (m , 6H).

A-3 (0.45 g, 8.3 mmol) was dissolved in 3 mL of anhydrous THF under nitrogen atmosphere and cooled to -78 ° C. 3.6 mL (9.04 mmol) of n-butyllithium was added dropwise to the mixture for 30 minutes, followed by stirring for 1 hour. Then 0.5 mL (8.9 mmol) of tri-isopropyl borate was added at -78 ° C and stirred overnight. The reaction mixture thus obtained was extracted with ether, dried over magnesium sulfate and purified by column chromatography using petroleum ether / ethyl acetate (2/1) as the developing solvent. As a result, 0.34 g (yield 75%) of A-4 was obtained as a white solid. The A-4 was confirmed using NMR, and it was as follows:

¹ H NMR (δ in CDCl ₃ ): 0.3-0.39 (m, 9H), 0.45-1.1 (m, 38H), 2.03-2.21 (m, 4H), 7.51-7.53 (d, 1H, J = 1.9 Hz), 7.6 (s, 1H), 7.77-7.79 (d, 1H, J = 0.9 Hz), 7.89-7.86 (d, 1H, J = 0.5 Hz), 8.25-8.26 (d, 2H, J = 5.7 Hz).

A-4 (0.73 g, 1.4 mmol) and pinacol (0.24 g, 2.1 mmol) were dissolved in 40 mL of toluene and stirred under reflux for 4 hours. The reaction mixture thus obtained was cooled, the reaction mixture was extracted with ether, dried over magnesium sulfate and purified by column chromatography using petroleum ether / methylene chloride (1/3) as the developing solvent. As a result, 0.52 g (71% yield) of intermediate A was obtained as a white solid. The intermediate A was identified using NMR, which was as follows:

¹ H NMR (CDCl ₃ ): 0.34 (s, 9H), 0.50-0.58 (m, 8H). 0.78-0.98 (m, 27H), 1.42 (s, 13H), 2.03-2.15 (d, 4H, J = 2.4 Hz), 7.48-7.52 (d, 1H, J = 1.2 Hz), 7.58-7.60 (s, 1H), 7.70-7.74 (d, 2H, J = 0.8 Hz), 7.81-7.85 (d, 1H, J = 2.4 Hz), 7.89-7.92 (d, 2H, J = 0.2 Hz).

Subsequently, compound 2 was synthesized according to Scheme 2b:

Intermediate A Intermediate B

Intermediate A (0.883 g, 1.5 mmol) and Intermediate B (0.122 g, 0.375 mmol) were dissolved in 30 ml of toluene, Pd (PPh ₃ ) ₄ (10 mg) and 2.0M Na ₂ CO ₃ solution (6.0 mL, 12.0 mmol) was added and stirred at 90 ° C for 24 h. The reaction mixture obtained is cooled, extracted with petroleum ether, dried over magnesium sulfate, the solvent is removed and the remaining material is subjected to column chromatography using petroleum ether / methylene chloride (9/1) as the developing solvent. Purified using. As a result, 0.285 g (yield 70%) of compound 2 was obtained as a white solid. Compound 2 was identified by using NMR, and it was as follows:

¹ H NMR (300 MHz, CDCl ₃ ): δ 0.28-0.33 (s, 18H), 0.45-0.57 (m, 28H), 0.64-0.90 (m, 32H), 2.06-2.08 (m, 8H), 4.04 ( s, 2H), 7.47-7.50 (d, 2H, J = 1.38 Hz), 7.54 (s, 2H), 7.61-7.71 (m, 10H), 7.76-7.78 (d, 2H, J = 2.1 Hz), 7.78 (s, 2H), 7.88-7.90 (d, 2H, J = 0.9 Hz).

Synthesis Example  2 Synthesis of Compound Having Chemical Formula 3 (hereinafter referred to as "Compound 3")

According to Scheme 3b, compound 3 was synthesized:

Intermediate A Intermediate A-2 Formula 3

Intermediate A (0.883 g, 1.5 mmol) and Intermediate A-2 (0.206 g, 0.375 mmol) prepared in Synthesis Example 1 were dissolved in 30 ml of toluene, Pd (PPh ₃ ) ₄ (10 mg) and 2.0M Na ₂ CO ₃ solution (6.0 mL, 12.0 mmol) was added and stirred at 90 ° C. for 24 h. The reaction mixture was cooled and extracted with petroleum ether, dried over magnesium sulfate, the solvent was removed and the remaining material was subjected to column chromatography using petroleum ether / methylene chloride (9/1) as the developing solvent. Purification by As a result, 0.246 g (50% yield) of compound 3 was obtained as a white solid. Compound 3 was identified by using NMR, and it was as follows:

¹ H NMR (300 MHz, CDCl ₃ ): δ 0.25-0.39 (s, 18H), 0.45-0.91 (m, 90H), 2.00-2.08 (m, 12H), 7.4-7.52 (d, 2H, J = 2.46 Hz), 7.52-7.65 (m, 10H), 7.69-7.71 (d, 2H, J = 0.61 Hz), 7.74-7.8 (m, 4H).

Evaluation example  One  -Thermal stability evaluation of compounds 2 and 3

The thermal stability of the compounds 2 and 3 was evaluated by measuring the Tg (glass transition temperature) and Tm (melting point) of each compound. Tg and Tm are thermal analysis using TGA (Thermo Gravimetric Analysis) and DSC (Differential Scanning Calorimetry) (N ₂ atmosphere, temperature range: room temperature ~ 600 ℃ (10 ℃ / min)-TGA, from room temperature to 400 ℃ -DSC, Pan Type: Pt Pan in Disposable Al Pan (TGA), Disposable Al pan (DSC)).

Compounds 2 and 3 do not thermally decompose to 400 ° C., and thus may have thermal stability suitable for use as an organic film of an organic light emitting device. In particular, see TGA data for Compound 2.

Evaluation example  2  Evaluation of Luminescence Properties of Compounds 2 and 3

The luminescence properties were evaluated by evaluating absorption spectra and PL (photoluminescence) spectra of compounds 2 and 3. First, Compound 2 was diluted in toluene at a concentration of 0.2 mM, and the absorption spectrum was measured using a Shimadzu UV-350 Spectrometer. Meanwhile, Compound 2 was diluted in toluene at a concentration of 10 mM and the PL (Photoluminecscence) spectrum was measured using an ISC PC1 Spectrofluorometer equipped with a Xenon lamp. The results are shown in FIG. 3, and the maximum absorption wavelength and maximum emission wavelength are summarized in Table 1, respectively. Compound 3 was also evaluated in the same manner, and the absorption spectrum and PL spectrum are shown in FIG. 3, and the maximum absorption wavelength and maximum emission wavelength are summarized in Table 1, respectively:

ε (M ^-1 cm ^-1 ) λabs / max (nm) λflu / max (nm) Δν (cm ^-1 ) Compound 2 102637 353 394 2947.88 Compound 3 143197 353 397 3139.68

* 1-cm path, 1 x 10 ^-5 M

3 and Table 1, it can be seen that the compounds 2 and 3 have a light emission characteristic suitable for the organic light emitting device.

Example  One

Using compound 2 as a light emitting layer forming material, an organic light emitting device was manufactured having the following structure: ITO / PEDOT (500 mV) / Compound 2 (500 mV) / Alq (200 mV) / LiF (10 mV) / Al (2000 mV). .

Anode cuts Corning's 15Ω / cm ² (1200Å) ITO glass substrate into 50mm x 50mm x 0.7mm sizes, ultrasonically cleans for 5 minutes in isopropyl alcohol and pure water, and then UV ozone cleansing for 30 minutes Was used. Bayer's PEDOT-PSS (AI4083) was coated on the substrate and heat-treated at 120 ° C. for 5 hours to form a hole injection layer of 500 μs. On top of the hole injection layer, a mixture containing 1% by weight of compound 2 in toluene was spin coated and then heat-treated at 110 ° C. for 30 minutes to form a light emitting layer having a thickness of 500 μs. Thereafter, an Alq compound was vacuum-deposited on the emission layer to form an electron transport layer having a thickness of 200 μs. LiF 10Å (electron injection layer) and Al 2000Å (cathode) were sequentially vacuum deposited on the electron transport layer, thereby manufacturing an organic light emitting device as shown in FIG. 1A. This is called sample 1.

Example  2

Using compound 2 as the light emitting layer forming material, an organic light emitting device having the following structure was manufactured: ITO / PEDOT (500 kcal) / 5 wt% Compound 2: 3-tert-butyl-9,10-di (naphth- 2-yl) anthracene (500 Hz) / Alq (200 Hz) / LiF (10 Hz) / Al (2000 Hz).

Instead of spin coating and heat-treating a mixture comprising 1% by weight of Compound 2 in toluene, to form a light emitting layer, 5% by weight of a dopant (3-tert-butyl) of 1% by weight of Compound 2 and Compound 2 in toluene An organic light-emitting device was manufactured in the same manner as in Example 1, except that the mixture including -9,10-di (naphth-2-yl) anthracene) was spin coated and heat treated. This is called sample 2.

Example  3

Using compound 2 as the light emitting layer forming material, an organic light emitting device having the following structure was manufactured: ITO / PEDOT (500 kcal) / 10 wt% Compound 2: 3-tert-butyl-9,10-di (naphth -2-yl) anthracene (500 Hz) / Alq (200 Hz) / LiF (10 Hz) / Al (2000 Hz).

Instead of spin coating and heat treating a mixture comprising 1% by weight of compound 2 in toluene to form a light emitting layer, 10% by weight of a dopant (3-tert-butyl) of 1% by weight of compound 2 and compound 2 in toluene An organic light-emitting device was manufactured in the same manner as in Example 1, except that the mixture including -9,10-di (naphth-2-yl) anthracene) was spin coated and heat treated. This is called sample 3.

Evaluation example  3  : Characterization of Samples 1 to 3

For samples 1 to 3, driving voltage, color purity, and efficiency were respectively evaluated using a PR650 (Spectroscan) Source Measurement Unit.

Sample No. Driving voltage / maximum voltage (100cd / m ² ) Color coordinates Efficiency (cd / A) One 3.8 / 5.6 (0.15, 0.16) 0.31 at 9 V 2 2.8 / 3.8 (0.15, 0.23) 1.07 at 3.6 V 3 2.8 / 4.0 (0.15, 0.21) 0.96 at 3.6 V

As described in Table 2, it can be seen that the device characteristics of Samples 1 to 3 according to the present invention are excellent.

According to the present invention, the fluorene-based compound represented by Formula 1 is suitable for being formed into a film by using a thermal transfer method including a wet process and / or a wet process. In addition, the organic light emitting device including the organic film including the fluorene-based compound has low driving voltage, excellent color purity, high efficiency, and high brightness.

Claims (9)

Fluorene compound represented by the following formula <Formula 1>

In Formula 1, R ₁ to R ₆ are each independently of the other hydrogen; C ₁ -C ₂₀ alkyl group unsubstituted or substituted with a halogen atom, cyano group, hydroxyl group or amino group; Or a C ₆ -C ₃₀ aryl group which is unsubstituted or substituted with a halogen atom, cyano group, hydroxyl group or amino group; R ₇ and R ₈ Independently of each other, hydrogen; Halogen atom; Cyano group; Hydroxyl group; Amino group; C ₁ -C ₂₀ alkyl group unsubstituted or substituted with a halogen atom, cyano group, hydroxyl group, amino group or C ₆ -C ₃₀ aryl group; C ₁ -C ₂₀ alkoxy group unsubstituted or substituted with a halogen atom, cyano group, hydroxyl group or amino group; C ₆ -C ₃₀ aryl group unsubstituted or substituted with a halogen atom, cyano group, hydroxyl group or amino group; C ₂ -C ₃₀ heteroaryl group unsubstituted or substituted with a halogen atom, cyano group, hydroxyl group or amino group; C ₅ -C ₂₀ cycloalkyl group unsubstituted or substituted with a halogen atom, cyano group, hydroxyl group or amino group; Or a C ₅ -C ₃₀ heterocycloalkyl group unsubstituted or substituted with a halogen atom, cyano group, hydroxyl group or amino group; A and B are, independently from each other, hydrogen; Linear, branched or cyclic C ₁ -C ₂₀ alkyl groups which are unsubstituted or substituted with halogen atoms, cyano groups, hydroxyl groups, amino groups or C ₆ -C ₃₀ aryl groups; Or a C ₆ -C ₃₀ aryl group which is unsubstituted or substituted with a halogen atom, cyano group, hydroxyl group or amino group; n ₁ and n ₂ are each independently an integer of 0 or 1 to 3; n is an integer from 1 to 5; When n is 2 or more, R ₇ and R ₈ substituted in each fluorene may be the same or different from each other, and A and B substituted in each fluorene may be the same or different from each other. The compound of claim 1, wherein A and B, independently of each other, are hydrogen; Or a linear, branched or cyclic C ₁ -C ₂₀ alkyl group which is unsubstituted or substituted with a halogen atom, cyano group, hydroxyl group, amino group or C ₆ -C ₃₀ aryl group. The fluorene-based compound of claim 1 having the formula 2, 3, 4 or 5 <Formula 2>

<Formula 3>

<Formula 4>

<Formula 5>

A first electrode; Second electrode; And an organic light emitting device comprising at least one organic film between the first electrode and the second electrode, wherein the organic film comprises the fluorene-based compound according to any one of claims 1 to 3. Organic light emitting device. The organic light emitting device of claim 4, wherein the organic layer comprises at least one layer selected from the group consisting of a hole injection layer, a hole transport layer, an electron blocking layer, a light emitting layer, a hole blocking layer, an electron transport layer, and an electron injection layer. . Forming a first electrode on the substrate; Forming an organic layer including the fluorene-based compound of any one of claims 1 to 3 on the first electrode; And Forming a second electrode on the organic layer; Method for manufacturing an organic light emitting device comprising a. The method of claim 6, wherein the forming of the organic layer is performed by using a wet process. The method of claim 6, wherein the forming of the organic layer is performed by using a thermal transfer method including a wet process. The method of claim 7, wherein the wet process is selected from a spin coating method, a casting method, an inkjet printing method, and a contact printing method.

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