KR20080088107A - Organosilanediethylbenamine compounds, light emitting materials comprising the same, and organic electroluminescent devices - Google Patents

Abstract

The organosilanediacetylbenamine compound according to the present invention has a structure represented by the following Chemical Formula 1.

[Formula 1]

Wherein A ₁ and A ₃ are each a substituted or unsubstituted arylene group having 6 to 30 carbon atoms or a heteroarylene group having 3 to 30 carbon atoms, and A _{2 and} A ₄ are hydrogen or a substituted or unsubstituted carbon number 6 Is an aryl group of up to 30, A ₅ is a substituted or unsubstituted aryl group from 6 to 30 carbon atoms, n is an integer of 1 to 3, Ar _{6 ,} Ar ₇ is hydrogen or a substituted or unsubstituted carbon number Aryl groups of 6 to 30 or heteroaryl groups of 3 to 30 carbon atoms.)

Description

OrganosilaneDistilbeneAmine Compounds, Electroluminiscent Materials Comprising The Same, and Organic Electroluminiscent Device

Figure 1a is a UV and PL curve of the solution of the organosilane diacetylbenamine compound 7 in accordance with an embodiment of the invention,

1B and 1C are thermal analysis curves of organosilanediacetylbenamine compound 7,

2 is a schematic view showing an organic electroluminescent device according to an embodiment of the present invention.

Brief description of symbols in the drawings

1: Substrate # 2: Anode

3: hole transport layer 4: light emitting layer

5: electron transport layer 6: cathode

The present invention relates to an organosilane diacetylbenamine compound, a light emitting material comprising the same, and an organic electroluminescent device using the same.

The light emitting mechanism of the organic electroluminescent device is as follows. Holes injected from the anode into the valence band or highest occupied molecular orbital (HOMO) of the hole injection layer (HIL) proceed to the emitting layer through the hole transporting layer (HTL). At the same time, electrons move from the cathode to the emission layer through the electron injection layer to combine with holes to form excitons. The exciton falls to the ground and emits light.

By using the principle of the organic electroluminescent device as described above, Eastman Kodak Co., Ltd. in 1987 used TPD (N-N'-DiphenyI-N-N'-bis (methylphenyl-1,1'-biphenyl) as the hole transport layer. An organic electroluminescent device was developed using Alq ₃ (tris (8-hydroxy- quinoline) aluminum complex) as a light emitting layer (-4,4'-diamine) ( Appl . Phys. Lett . , 51, 913, 1987). Research into electroluminescent devices using organic materials has been actively conducted.

Up to now, Eastman Kodak's Alq3 is widely used as a green light emitting material, but blue light emitting material has much improvement such as luminous efficiency and lifetime.

Meanwhile, studies on hole transporting materials and blue light emitting materials using anthracene derivatives are being conducted. In addition, materials emitting blue light using anthracene and biantracene based materials and aromatic dimethylidine compounds may be used. Although blue luminescent compounds that interfere with crystallization of phenyl groups have been studied, they are still insignificant.

The present inventors intend to disclose a material for an organic electroluminescent device in which a variety of aryl groups are introduced based on silicon having a strong electron affinity and stilbene groups that facilitate the flow of electrons, thereby increasing stability and luminous efficiency of the device. .

It is an object of the present invention to provide organosilanediacetylbenamine compounds which are particularly suitable for use as blue light emitting materials.

The present invention for achieving the above object,

It provides a distilbenamine organic silane compound having the structure of formula (1).

[Formula 1]

Wherein A ₁ and A ₃ are each a substituted or unsubstituted arylene group having 6 to 30 carbon atoms or a heteroarylene group having 3 to 30 carbon atoms, and A _{2 and} A ₄ are hydrogen or a substituted or unsubstituted carbon number 6 Is an aryl group of up to 30, A ₅ is a substituted or unsubstituted aryl group from 6 to 30 carbon atoms, n is an integer of 1 to 3, Ar _{6 ,} Ar ₇ is hydrogen or a substituted or unsubstituted carbon number Aryl groups of 6 to 30 or heteroaryl groups of 3 to 30 carbon atoms.)

In addition, the A _1, A _3, A ₅ is selected from phenyl, naphthalene, and anthracene, A ₂ , A ₄ is selected from hydrogen, phenyl, naphthalene, and anthracene, A _6, A ₇ is phenyl, naphthalene, It provides a distilbenamine organic silane compound, which is selected from an aryl group, an stilbene aryl group, and a heteroaryl group containing anthracene.

In addition, it provides a light emitting material comprising the disilbeneamine organic silane compound.

In addition, the organic electroluminescent device comprising an anode, a cathode and a light emitting layer, the light emitting layer provides an organic electroluminescent device, characterized in that comprises the above-described light emitting material.

Hereinafter, the present invention will be described in more detail. Since the following detailed description is given by way of example of the invention, even if there is a limited expression, the scope of the rights defined by the claims are not limited thereto.

The organosilanediacetylbenamine compound according to the present invention has a structure represented by the following Chemical Formula 1.

[Formula 1]

Wherein A ₁ and A ₃ each represent a substituted or unsubstituted arylene group having 6 to 30 carbon atoms or a heteroarylene group having 3 to 30 carbon atoms. A _{2 and} A ₄ are hydrogen or a substituted or unsubstituted aryl group having 6 to 30 carbon atoms. A <_5> is a substituted or unsubstituted C6-C30 aryl group, n is an integer of 1-3. Ar _{6 and} Ar ₇ are hydrogen or a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, or a heteroaryl group having 3 to 30 carbon atoms.

Specific examples that may be selected as A ₁ , A ₂ , A ₃ , A _4, A _5, A _{6, and} A ₇ are as follows. However, it is not limited thereto. In addition, the coupling position indicated by the solid line is only an example and includes the coupling in other positions.

More preferably, the A _1, A _3, A ₅ is selected from phenyl, naphthalene, and anthracene, A ₂ , A ₄ is selected from hydrogen, phenyl, naphthalene, and anthracene, A _6, A ₇ is phenyl , Phthalic group containing naphthalene, anthracene, stilbene aryl group, heteroaryl group is preferably selected.

The introduction of organosilanes, especially organosilandisylbenamines, included in the compound structure according to the present invention can lower LUMO (lowest unoccupied molecular orbital), and the relatively short π- because the silicon element is involved in the d-orbital. Has a conjugation length. In addition, the silyl derivative is suitable for use as a light emitting device that emits blue light by acting as an electron pulling body and increasing a band gap. Furthermore, the introduction of silicon can serve as an effective electron transport material in π-electronic systems containing silicon. In addition, the electron transport ability can be doubled by introducing a distilbene group.

Since the silane-based compound according to the present invention does not exist in the same plane on the tetravalent silicon compound in the formula (1) serves to increase the luminous efficiency by inhibiting concentration quenching by preventing the packing between the molecules. In addition, the phenyl silicon introduced in the present invention improves the interfacial properties with the electrode and the thin film forming ability. In addition, by introducing a stilbene group having an aryl group represented by Chemical Formula 1, the efficiency of the electron transport is increased while increasing the electron transport ability.

In the following, a preferred example of the organosilanediacetylbenamine compound of Formula 1 according to the present invention is shown, but is not limited thereto.

Formula 1 Formula 2 Formula 3

Formula 4 Formula 5 Formula 6

Formula 7 Formula 8 Formula 9

Chemical Formula 10 Chemical Formula 11 Chemical Formula 12

Chemical Formula 13 Chemical Formula 14 Chemical Formula 15

        Chemical Formula 16 Chemical Formula 17

        Formula 18 Formula 19

Hereinafter, a light emitting material according to the present invention will be described.

The present invention provides a light emitting material including the organosilane diacetylbenamine compound of Formula 1. All of the light emitting materials containing the organosilane diacetylbenamine compound of Formula 1 are included in the present invention. In addition, the following light emitting materials used in the organic electroluminescent device may be further included.

Examples of the blue light emitting material include, but are not limited to, compounds of Formula 1, (4,4'-bis (2,2-diphenyl-ethen-1-yl) diphenyl (DPVBi), Bis (styryl) amine (DSA) system, bis (2-methyl-8-quinolinolato) (triphenylsiloxy) aluminum (III) (SAlq), bis (2-methyl-8-quinolinolato (Para-phenolato) aluminum (III) (BAlq), bis (salen) jin (II), 1,3-bis [4- (N, N-dimethylamino) phenyl-1,3,4-oxa Diazolyl] benzene (OXD8), 3- (biphenyl-4-yl) -5- (4-dimethylamino) 4- (4-ethylphenyl) -1,2,4-triazole (p-EtTAZ) , 3- (4-biphenyl) -4-phenyl-5- (4-tert-butylphenyl) -1,2,4-triazole (TAZ), 2, 2 ', 7, 7'-tetrakis (Non-phenyl-4-yl) -9,9'-spirofluorene (Spiro-DPVBI), tris (para-ter-phenyl-4-yl) amine (p-TTA), 5,5-bis (di Methylboryl) -2,2-bithiophene (BMB-2T) and perylene may be further included, and in particular, (4,4'-bis (2,2-diphenyl-ethen-1-yl) Diphenyl (DPVBi), Bis Preference is given to (styryl) amine (DSA) systems.

In the case of a red light emitting material and a green light emitting material, the compound of Formula 1 may be included, and the green light emitting material used in the art may be further included. The red and green light emitting materials used in the art are well known and thus detailed descriptions thereof will be omitted.

In the case of the light emitting material containing the compound of Formula 1, it is particularly excellent to apply to blue light emission.

Hereinafter, an organic electroluminescent device according to the present invention will be described.

The organic electroluminescent device according to the present invention is an organic electroluminescent device comprising an anode, a cathode and a light emitting layer, wherein the light emitting layer comprises the above-described light emitting material.

2 is a diagram illustrating an organic electroluminescent device according to an embodiment of the present invention, wherein the substrate 1, the anode 2, the hole transport layer 3, the light emitting layer 4, and the electron transport layer 5 are shown. ) And a cathode 6.

Examples of the anode (2) material include metal oxides or metal nitrides such as ITO, IZO, tin oxide, zinc oxide, zinc aluminum oxide, and titanium nitride; Metals such as gold, platinum, silver, copper, aluminum, nickel, cobalt, lead, molybdenum, tungsten, tantalum and niobium; Alloys of these metals or alloys of copper iodides; Conductive polymers such as polyaniline, polythiopine, polypyrrole, polyphenylene vinylene, poly (3-methylthiopine), and polyphenylene sulfagard. The anode 2 may be formed of only one type of the aforementioned materials or may be formed of a mixture of a plurality of materials. In addition, a multilayer structure composed of a plurality of layers of the same composition or different compositions can be formed.

The hole transport layer 3 is 4,4'-bis [N- (1-naphthyl) -N-phenyl-amino] -biphenyl (NPD) or N, N'-diphenyl-N, N'- A substance such as bis (3-methylphenyl) -1,1'-biphenyl-4,4'-diamine (TPD) can be used.

The light emitting layer 4 is characterized in that it comprises the above-described light emitting material, it has been described above in detail, it is well known in the art and will not be described.

The electron transport layer 5 may include an aryl substituted oxadiazole, aryl-substituted triazole, aryl-substituted phenanthroline, benzoxazole, or benzoxazole compound, for example, 1, 3-bis (N, Nt-butyl-phenyl) -1,3,4-oxadiazole (OXD-7); 3-phenyl-4- (1'-naphthyl) -5-phenyl-1,2,4-triazole (TAZ); 2,9-dimethyl-4,7-diphenyl-phenanthroline (vasocuproin or BCP); Bis (2- (2-hydroxyphenyl) -benzoxazolate) zinc; Or bis (2- (2-hydroxyphenyl) -benz thiazolate) zinc; As the electron transporting material, (4-biphenyl) (4-t-butylphenyl) oxadiazole (PDB) and tris (8-quinolinato) aluminum (III) (Alq3) can be used, preferably Tris ( Preference is given to 8-quinolinato) aluminum (III) (Alq3).

As the cathode 6 of the present invention, a metal having a low work function such as Al, Ca, Mg, Ag, or the like can be used, and preferably Al is used.

Hereinafter, the present invention will be described in more detail with reference to the synthesis example of the organosilane compound according to an embodiment of the present invention and the organic electroluminescent device manufacturing example.

Synthesis Example

Synthesis Example  1: Synthesis of Compound 7

4- Iodinephenyl - Triphenylsilane  synthesis

As in Scheme 1, 4 g (17 mmol) of diiodine benzene was dissolved in tetrahydrofuran, the temperature was lowered, butyllithium was added, and trichlorophenylsilane was added thereto to react at room temperature. After the reaction, the reaction product was extracted using ethyl acetate, and the solvent was removed under reduced pressure. The product was purified by column and then dried under reduced pressure filtration.

¹ H-NMR (CDCl ₃ , ppm): 7.54-7.5 (m, Ar-H), 7.45 (Ar-H), 7.40-7.35 (m, Ar-H)

4- Bromostilbentriphenyl Silane  synthesis

4-iodinephenyl-triphenylsilane 10.0 g (0.0216 mol), 4-bromosstyrene 7.92 g (0.0433 mol), potassium carbonate 6.16 g (0.0433 mol), palladium acetate 0.29 g (0.0013 mol), thibutylammonium After adding 7.67 g (0.0238 mol) of broide, 150 mL of dimethylacetamide as a solvent was added thereto, and reacted at 80 ° C. for 2 hours. After completion of the reaction with methanol, the resulting solid was filtered. The resulting solid is heated with an excess of tetrahydrofuran and then impurities are removed using celite. Then, the obtained reaction solution was distilled under reduced pressure to obtain a solid. This solid was reprecipitated with tetrahydrofuran and methanol to give the product.

¹ H-NMR (CDCl ₃ ): 7.093 (s, 1H), 7.45 (Ar-H), 7.40-7.60 (m, 24H)

4- Styrenephenyl -2- Of dynaphylamine  synthesis

5.0 g (18.6 mmol) of 2-dynaphthylamine, 5.10 g (27.8 mmol) of 4-bromosstyrene, 2.76 g (27.8 mmol) of sodibutybutoxide, 1.02 g (1.1 mmol) of palladium catalyst, Vinep 1.39 g (2.2 mmol) was added, toluene as a solvent was added, and the mixture was heated and reacted at 80 degrees for 1 hour. After the completion of the reaction, the produced solid is washed with methanol, and then precipitated again with tetrahydrofuran and methanol to obtain a product.

¹ H -NMR (CDCl ₃ ): 5.180 (d, 1H), 5.670 (d, 1H), 6.70 (m, 1H), 7.12 (d, 2H)

7.295-7.399 (m, 8H), 7.450 (d, 2H), 7.601 (m, 2H), 7.790 (m, 4H)

Synthesis of Compound 7

4-bromosylbentriphenyl silane 3.05 g (5.9 mmol) synthesized above, 2.63 g (7.1 mmol) 4-styrene phenyl-2- dynaphylamine, 1.68 g (11.8 mmol) potassium carbonate, 0.08 palladium catalyst g (0.4 mmol) and 2.09 g (6.5 mmol) of tetrabutylammonium bromide were added thereto, followed by adding dimethylacetamide as a solvent and reacting at 80 ° C for 5 hours. After completion of the reaction, the reaction product is poured into methanol, the resulting solid is filtered, and then precipitated again with tetrahydrofuran and methanol to obtain a product.

¹ H-NMR (CDCl ₃ ): 7.158-7.232 (m, 3H), 7.30-7.66 (m, 30H), 7.68-7.74 (t, 1H), 7.78-7.84 (m 4H), 8.00-8.089 (dd, 8H)

Fabrication of the device

Example  1: Preparation of Blue Organic Electroluminescent Device

M-MTDATA [4,4`, 4` having a structure of Formula 2-2 as a hole injection layer thereon after forming an ITO electrode on a glass substrate, followed by UV-ozone cleaning or oxygen plasma cleaning. `-tris (3-methylphenylamino) triphenylamine] was deposited to a thickness of 500 mm3. After depositing NPD (N, N'-bis (naphthalen-1-yl) -N, N'-bis (phenyl) benzidine) having a structure of the following formula 2-3 as a hole transport layer to 200Å thickness, As a blue light-emitting host material, a light emitting layer was formed to a compound having a structure of 2-6 in the following chemistry and a thickness of 40 Å of the dopant compound . As an electron transport layer, Alq3 (tris- (8-hydroxyquinoline) aluminum (III)) having a structure of Chemical Formula 2-4 was vacuum deposited to a thickness of 200 Å. Thereafter, an Al: Li layer was vacuum-deposited as a cathode on the top to form a 1000 μm thick aluminum / lithium electrode to prepare a blue organic electroluminescent device.

Comparative example  1: blue Light emitting layer  Fabrication of Blue Organic Light Emitting Diode Using Chemical Formula (2-5) as a Material

When the emission layer was formed, a blue organic electroluminescent device was manufactured in the same manner as in Example 1, except that DPVBi (Compound 2-5) was used as a blue light emitting material instead of using Compound 1.

Comparative example  2: blue formula (2-6) Light emitting layer  Fabrication of Blue Organic Electroluminescent Devices Used as Materials

When the emission layer was formed, a blue organic electroluminescent device was manufactured in the same manner as in Example 2, except that Compound 2-6 was used as a blue light emitting material instead of Compound 1.

The equipment used in the Example used EL deposition machine of VTS. Characteristics of the organic electroluminescent device manufactured as described above, that is, driving voltage, color coordinate, and efficiency measuring method are as follows.

1) Driving voltage

The change of current density according to the voltage change was measured for the manufactured organic electroluminescent device. In the measurement, the current density was increased from 2.5 mA / cm ² to 100 mA / cm ² in increments of 2.5 mA, and the current value flowing through the unit device was measured using a current-voltmeter (Kethley SMU 236).

2) color coordinates

The current density of the manufactured organic electroluminescent device was measured using a colorimeter (Minolta CS-100A) while increasing the current density from 2.5 mA / cm ² to 100 mA / cm ² in increments of 2.5 mA.

3) efficiency

Luminous efficiency was calculated using the brightness and current density measured above.

4) EL max

The power was supplied from a power supply (Kethley SMU 236) and the wavelength was determined as EL max at the highest intensity of the spectrum taken from photodiodes (Ocean Optics).

The results of Example 1 and Comparative Examples 1 and 2 measured by the above method are shown in Table 1 below.

TABLE 1

EL max Driving voltage Color coordinates Luminous efficiency Power efficiency Example 1 460 nm @ 10mA / cm ² 8.5 V @ 10 mA / cm ² (0.15, 0.16) @ 10mA / cm ² 6.20 cd / A @ 10mA / cm ² 2.11 lm / W @ 10mA / cm ² Comparative Example 1 465 nm @ 10mA / cm ² 9 V @ 10 mA / cm ² (0.15, 0.16) @ 10mA / cm ² 3.12 cd / A @ 10mA / cm ² 1.11 lm / W @ 10mA / cm ² Comparative Example 2 472 nm @ 10mA / cm ² 8.8 V @ 10 mA / cm ² (0.15, 0.17) @ 10mA / cm ² 5.6 cd / A @ 10mA / cm ² 2.01 lm / W @ 10mA / cm ²

The present invention has the effect of providing an organic light emitting material and an organic electroluminescent device comprising the same, an organosilane dysylbenamine compound suitable for use as a blue light emitting material. In particular, the silane-based compound has excellent thermal stability and can be used as a blue light emitting material in an organic electroluminescent device, and when the thermal analysis results are considered, the thermal stability was also excellent.

Claims (4)

Distilbenamine organic silane compound which has a structure of following General formula (1). [Formula 1]

Wherein A ₁ and A ₃ are each a substituted or unsubstituted arylene group having 6 to 30 carbon atoms or a heteroarylene group having 3 to 30 carbon atoms, and A _{2 and} A ₄ are hydrogen or a substituted or unsubstituted carbon number 6 Is an aryl group of up to 30, A ₅ is a substituted or unsubstituted aryl group from 6 to 30 carbon atoms, n is an integer of 1 to 3, Ar _{6 ,} Ar ₇ is hydrogen or a substituted or unsubstituted carbon number Aryl groups of 6 to 30 or heteroaryl groups of 3 to 30 carbon atoms.) The method of claim 1, wherein A _1, A _3, A ₅ are selected from phenyl, naphthalene, and anthracene, A ₂ , A ₄ is selected from hydrogen, phenyl, naphthalene, and anthracene, and A _6, A ₇ is A distilbenamine organic silane compound, characterized in that it is selected from aryl group containing phenyl, naphthalene, anthracene, stilbene aryl group, heteroaryl group. A light emitting material comprising the distilbenamineorganosilane compound of claim 1 or 2. An organic electroluminescent device comprising an anode, a cathode and a light emitting layer, wherein the light emitting layer comprises the light emitting material of claim 3.

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