KR100367719B1 - Blue light-emitting compounds, preparing method thereof and display device employing the same - Google Patents

Abstract

The present invention provides a blue light emitting compound represented by the formula (1), a method of manufacturing the same, and a display device employing the blue light emitting compound.

In the above formula,

X is -O-, -S-, -NH-, -NCH _3- , -NCH ₂ CH _3- , -NCH ₂ (CH ₂ ) _n CH _3- , -NCOOCH _3- , n is 1 to Is an integer of 20 and Y1, Y2, Y3 and Y4 are selected from the group consisting of phenyl group, alkylphenyl group, biphenyl group, alkylbiphenyl group, naphthyl group and alkylnaphthyl group irrespective of each other. The compound of Formula 1 is a material emitting blue fluorescence, which is very useful as a hole transport layer, an electron transport layer, or a light emitting layer forming material of an organic electroluminescent device. Therefore, the use of the compound of Formula 1 may improve the performance, such as luminous efficiency, driving start voltage, brightness of the organic electroluminescent device. In addition, the compound of the formula (1) can be applied as a coloring material of various display devices.

Description

Blue light-emitting compounds, preparing method according to example and display device employing the same}

The present invention relates to a light emitting compound that emits fluorescence in the blue region, a method of manufacturing the same, and a display device employing the same.

An organic electroluminescence device (EL device) is classified into an inorganic EL device and an organic EL device according to a material for forming an emitter layer. Herein, the organic EL device has an advantage of excellent luminance, driving voltage, and response speed, and multicoloring, compared to the inorganic EL device.

1 is a cross-sectional view showing the structure of a general organic EL device. Referring to this, an anode 12 is formed on the substrate 11. On the anode 12, a hole transport layer 13, a light emitting layer 14, an electron transport layer 15, and a cathode 16 are sequentially formed. Here, the hole transport layer 13, the light emitting layer 14, and the electron transport layer 15 are organic thin films made of an organic compound.

The driving principle of the organic EL element having the above structure is as follows.

When a voltage is applied between the anode 12 and the cathode 16, holes injected from the anode 12 are moved to the light emitting layer 14 via the hole transport layer 13. On the other hand, electrons are injected into the light emitting layer 14 from the cathode 16 via the electron transport layer 15, and carriers recombine in the light emitting layer 14 region to generate excitons. This exciton is changed from an excited state to a ground state, whereby an image is formed by the fluorescent molecules of the light emitting layer emitting light.

In the organic EL device as described above, the degree of hole injection and transport at the cathode should be well balanced with the degree of electron injection and transport at the anode. In particular, the hole transport material layer functions to reduce the energy barrier of charge injected into the electrode to realize a high performance EL element.

Accordingly, a technical object of the present invention is to provide a blue light emitting compound that can be used as an organic film forming material such as a hole transport layer, a light emitting layer, etc. of the organic EL device, and emits fluorescence in a blue region, and a method of manufacturing the same.

Another technical problem to be achieved by the present invention is to provide an organic electroluminescent device having excellent performances such as luminous efficiency, brightness, driving start voltage, etc. by employing the blue light emitting compound.

Another technical problem to be achieved by the present invention is to provide a display device having excellent performance such as luminous efficiency by employing the blue light emitting compound.

1 is a view schematically showing the structure of a general organic electroluminescent device,

2A is a view for explaining the synthesis process of the blue light emitting compound of Formula 4 according to the present invention,

2B is a view for explaining the synthesis process of the blue light emitting compound of Formula 5 according to the present invention;

Figure 3 shows the visible light absorption spectrum and emission spectrum of PFDA, FurylBZ, PFDA-PPh ₄ , FurylBZ-PPh ₄ prepared according to Examples 1 and 2 of the present invention, respectively.

<Brief description of the main parts of the drawing>

11 ... substrate 12 ... anode

13 ... hole transport layer 14 ... light emitting layer

15 ... electron transport layer 16 ... cathode

In order to achieve the first technical problem, the present invention provides a blue light emitting compound represented by Chemical Formula 1.

<Formula 1>

In the above formula,

X is -O-, -S-, -NH-, -NCH _3- , -NCH ₂ CH _3- , -NCH ₂ (CH ₂ ) _n CH _3- , -NCOOCH _3- ,

n is an integer from 1 to 20

Y1, Y2, Y3 and Y4 are independently selected from the group consisting of phenyl group, alkylphenyl group, biphenyl group, alkylqlphenyl group, naphthyl group and alkylnaphthyl group.

The second technical problem of the present invention is achieved by a method for preparing a blue light emitting compound of Formula 1, wherein the compound of Formula 2 or Formula 3 is obtained through an aryl amination or alkylaryl amination reaction. .

<Formula 1>

In the above formula,

X is -O-, -S-, -NH-, -NCH _3- , -NCH ₂ CH _3- , -NCH ₂ (CH ₂ ) _n CH _3- , -NCOOCH _3- ,

n is an integer from 1 to 20

Y1, Y2, Y3 and Y4 are independently selected from the group consisting of phenyl group, alkylphenyl group, biphenyl group, alkylbiphenyl group, naphthyl group and alkylnaphthyl group.

A third technical problem of the present invention is achieved by a display device employing the blue light emitting compound of Chemical Formula 1 as a coloring material. In a preferred aspect of the present invention, in an organic electroluminescent device comprising an organic film provided between a pair of electrodes,

An organic electroluminescent device is characterized in that the organic film contains a blue light emitting compound of the formula (1).

<Formula 1>

In the above formula,

X is -O-, -S-, -NH-, -NCH _3- , -NCH ₂ CH _3- , -NCH ₂ (CH ₂ ) _n CH _3- , -NCOOCH _3- ,

n is an integer from 1 to 20

Y1, Y2, Y3 and Y4 are independently selected from the group consisting of phenyl group, alkylphenyl group, biphenyl group, alkylbiphenyl group, naphthyl group and alkylnaphthyl group.

In the blue light emitting compound according to Chemical Formula 1 of the present invention, Y1, Y2, Y3, and Y4 are one selected from the group consisting of phenyl group, alkylphenyl group, biphenyl group, alkylbiphenyl group, naphthyl group and alkylnaphthyl group. In the alkylphenyl group, alkylbiphenyl group and alkylnaphthyl group, alkyl represents an alkyl group having 1 to 30 carbon atoms, and specific examples of the alkylphenyl group include 4-methylphenyl group, 4-ethylphenyl group, and the like, and specific examples of the alkylbiphenyl group. Examples of the alkyl naphthyl group include 2-methylbiphenyl group and 4-ethylbiphenyl group. Examples of the alkyl naphthyl group include 4-methylnaphthyl group and 4-ethylnaphthyl group.

In particular, the blue light emitting compound of Formula 1 is

And it is preferable that Y1, Y2, Y3, and Y4 are a compound of the following structural formula which is a phenyl group.

The method for synthesizing the blue light emitting compound of Formula 1 will be described by taking the case of the compounds of Formulas 4 and 5 as representative compounds. Figure 2a is a view showing the synthesis process of the compound of formula 4, Figure 2b is a view showing the synthesis process of the compound of formula (5). 2A-2B, the compounds of Formulas 4 and 5 are synthesized through aryl amination polymerization of the diamine compounds of Formulas 2 and 3.

First, NaNO ₂ and NaBF ₄ are added to aniline having a nitro group in the para position and aniline having a nitro group in the meta position, followed by reaction to obtain compounds (1) and (5). Then, a puryl group which forms a conjugated bond with benzene is introduced into the compounds (1) and (5) through denitrification using a base catalyst to obtain an aromatic nitro compound (2) or (6). Here, triethylamine is used as the base catalyst of the denitrification reaction. This aromatic nitro compound (2) or (6) is dissolved in an organic solvent, and zinc (Zn) and sodium hydroxide (NaOH) are added thereto to carry out a coupling reaction to obtain an azobenzene compound (3) or (7). Can be.

Subsequently, the azobenzene compound (3) or (7) is dissolved in an organic solvent, and then zinc and ammonium chloride are added thereto to carry out a reduction reaction to obtain a hydrazo compound (4) or (8). Thereafter, the acid catalyst transfer reaction of the hydrazo compound (4) or (8) at low temperature is carried out. That is, when the hydrazo compound (4) or (8) is slowly added over 1 hour while stirring at a low temperature (0 to 5 ° C.), and then stored at a low temperature of 0 to 5 ° C. for 1 to 2 days, Formula 2 Or a benzidine derivative which is a diamine compound having a furyl group of formula 3 introduced therein. In this case, when the benzidine transfer reaction of the hydrazo compound (4) or (8) is carried out under an acid catalyst, various other isomers may be generated in addition to the benzidine derivative of Formula 2 or Formula 3. Therefore, only the desired benzidine derivatives of formula (2) or (3) should be purely separated through separation methods such as column chromatography and recrystallization.

Subsequently, bromobenzene is added to the benzidine derivative of Formula 2 or Formula 3 thus formed, and an aryl amination reaction is carried out using a palladium complex catalyst having a phosphine ligand and tert-butoxide hydroxide to dehydrogenate and dehalogenate. 4 or a compound of formula 5 is obtained. Here, tritertbutyl phosphine is used as the phosphine ligand, and a synthetic route thereof is shown in Scheme 1 below.

Phosphorus trichloride is added to Grignard reagent (9) made from magnesium (Mg) and 2-chloro-2-methylpropane and reacted at 10 to 80 ° C. for 1 to 6 hours to prepare compound (10). This compound (10) is reacted with an organolithium compound such as tertbutyllithium to obtain tritertbutyl phosphine (11).

In Formula 1, Y1, Y2, Y3, and Y4 are alkylphenyl groups, biphenyl groups, alkylbiphenyl groups, naphthyl groups, and alkylnaphthyl groups other than phenyl groups, and X is -S-, -NH-, -NCH _3- , -NCH ₂ CH ₃ -,-NCH ₂ (CH ₂ ) _n CH _3- , -NCOOCH ₃ -can also be synthesized according to a method substantially similar to the above-described manufacturing method.

Hereinafter, a method of manufacturing an organic electroluminescent device employing a blue light emitting compound according to Chemical Formula 1 will be described.

First, an anode electrode material is coated on the substrate. Here, a substrate used in a conventional organic EL device is used, and a glass substrate or a transparent plastic substrate excellent in transparency, surface smoothness, ease of handling, and waterproofness is preferable. In addition, transparent and excellent indium tin oxide (ITO), tin oxide (SnO ₂ ), and zinc oxide (ZnO) are used as the anode electrode material.

The hole transport layer is formed by vacuum deposition or spin coating a material for forming a hole transport layer on the anode electrode.

The hole transport material is not particularly limited, and the compound of formula 1 according to the present invention, N, N'-bis (3-methylphenyl) -N, N'-diphenyl- [1,1'-biphenyl]- 4,4'-diamine (TPD), N, N'-di (naphthalen-1-yl) -N, N'-diphenyl-benzidine {N, N'-di (naphthalene-1-yl) -N, N'-diphenyl-benzidine: α-NPD} and the like.

Subsequently, a light emitting compound is vacuum-deposited on the hole transport layer to form a light emitting layer. Here, the light emitting layer is made of a light emitting compound of Formula 1 or a conventional light emitting layer forming material.

Thereafter, an organic EL device is completed by forming a cathode by vacuum depositing a metal for forming a cathode on the light emitting layer. The cathode is formed by vacuum evaporation of a metal such as lithium (Li), magnesium (Mg), aluminum (Al), or calcium (Ca) alone, or aluminum (Al) and lithium (Li) simultaneously, and magnesium (Mg). ) And indium (In) are formed at the same time or magnesium (Mg) and silver (Ag) at the same time by vacuum deposition.

The electron transport layer may be formed on the emission layer before forming the cathode. This electron transport layer uses a conventional material for forming an electron transport layer. In some cases, the compound of Formula 1 according to the present invention may be used as a material for forming an electron transport layer.

The organic electroluminescent device of the present invention can further form an intermediate layer for improving properties between two layers selected from an anode, a hole transport layer, a light emitting layer, an electron transport layer and a cathode. For example, a hole injection layer (HIL) may be further formed between the anode and the hole transport layer. If the hole injection layer is formed in this way, the hole transport layer (for example, α-NPD) and the anode (ITO) may be formed. This improves adhesion and helps to inject holes from the anode into the hole transport layer.

The hole injection layer forming material is not particularly limited, but 4,4, ', 4 "-tris (N-3-methylphenyl-N-phenyl-amino) triphenylamine (m-MTDATA) and the like are used.

The organic EL device may be manufactured in the order described above, that is, in the order of anode / hole transport layer / light emitting layer / electron transport layer / cathode, or in the reverse order, that is, cathode / electron transport layer / light emitting layer / hole transport layer / anode order. You may manufacture.

As described above, the compound of Formula 1 may be used as a light emitting layer, an electron transport layer or a hole transport layer forming material. In addition, the compound of Formula 1 may be applied as a coloring material of other display devices.

Hereinafter, the present invention will be described in detail with reference to the following Synthesis Examples and Examples, but the present invention is not limited to the following Synthesis Examples and Examples.

Synthesis Example. Preparation of Tri-tert-butyl phosphine catalyst.

Dissolve 300 ml of ethyl ether in 19.5 g of magnesium (Mg), and add a mixed solution of 74 g (0.8 mol) of 2-chloro-2-methyl propane and 300 ml of ethyl ether dropwise over 3 hours to obtain a Grignard reagent solution (9 )

28 g (0.2 mol) of Phosphorus trichloride was slowly added to Compound (9) synthesized above, which was then reacted at 40 ° C. for 6 hours. Subsequently, the reaction mixture was evaporated under reduced pressure to remove ethyl ether, distilled at 0.5 torr (bath temperature: about 290 ° C.) to obtain a mixed compound in a vessel cooled to about −50 ° C. Thereafter, the obtained distillation stock solution was fractionated again to obtain Compound (10) (yield: 12.3 g (34%)).

b.p. 38-40 ° C .;

1 H-NMR (δ, CDCl ₃ ), 1.46-1.37 ppm (d, Cl-P- [C- ( CH ₃ ) ₃ ] ₂ )

The compound (10) was dissolved in 10 ml of benzene, and 150 mmol of tert butyllithium was dissolved in pentane, and slowly added thereto. The reaction mixture was reacted at 50 to 80 ° C. for 4 hours, and then distilled at 110 ° C. to collect the distillate in a vessel cooled to −50 ° C. This distillation stock solution was fractionated and distilled to obtain tritertbutylphosphine (11) (yield: 12.2 g (50%)).

m.p. 30 ° C .;

b.p. 103 ° C .;

1 H-NMR (δ, CDCl ₃ ), 1.36-1.30 ppm (d, Cl-P- [C- ( CH ₃ ) ₃ ] ₂ )

Example 1 Synthesis of Bis (5- (4-aminophenyl))-2,2'-furyl (PFDA) and Bis (5- (N, N-diphenyl aminophenyl) -2-furyl) (PFDA- PPh ₄ Manufacturing

Dissolve 10g (72.5mmol) of para-nitroaniline in a mixed solution of hydrochloric acid and water, adjust this mixed solution to 0-5 ℃ using an ice bath, and dissolve 6g (85mmol) of NaNO _{2 in} 20ml of water. Added slowly.

The reaction mixture was stirred for about 30 minutes, and then 16 g (140 mmol) of NaBF ₄ were added thereto and stirred for 1 hour. Subsequently, the produced solid was filtered to yield a white powder. This powder was washed sequentially with water, ethanol and ethyl ether to give compound (1) (yield: 16.8 g (98.2%)).

7.5 g (31.6 mmol) of the compound (1) was added to 40 ml of pure furan purified in a nitrogen atmosphere, and stirred for 30 minutes in an ice bath to maintain a temperature of 0-5 ° C in the reaction vessel. Then, a solution of dilute 6.3 ml of triethylamine was slowly added to 20 ml of furan with vigorous stirring of the reaction mixture. After the addition of the furan solution of triethylamine, excess hexane was quickly added to the reaction mixture. The resulting mixture was separated using column chromatography and recrystallized from a mixture of ethanol and water to obtain Compound (2) (X = O) (yield: 4.9 g (82.0%)).

21.0 g (111 mmol) of the compound (2) was dissolved in 150 mL of n-propyl alcohol, and then, to which 40.2 mL of water was dissolved 17.76 g (444 mmol) was added. Subsequently, 14.5 g (222 mmol) of zinc powder was added to the reaction mixture and refluxed for one day. The reaction mixture was filtered while hot, the filtrate was extracted with chloroform and recrystallized from tetrachloroethane to give azobenzene compound (3) (X = O) (yield: 14.7 g (89.0%)).

0.6 g (1.9 mmol) of the azobenzene compound (3) (X = O) was dissolved in 30 ml of acetone under a nitrogen atmosphere, 2 ml of a saturated NH ₄ Cl aqueous solution and 1.2 g of zinc powder were added together, and vigorously shaken until the red color disappeared. . Subsequently, the reaction mixture was filtered through 10% ammonia water to obtain a hydrazo compound (4) (X = O) as an off-white solid.

Hydrazo Compound (4) (X = O) 1.0 g (3.16 mmol) synthesized above was dissolved in 50 ml of ethyl alcohol under a nitrogen atmosphere, and the temperature of the reaction vessel was adjusted to 0-5 ° C. using an ice bath, followed by ethyl alcohol. 20 ml of a mixture of hydrochloric acid (volume ratio = 1: 1) was slowly added over 1 hour and stored in a cold place for one day. Thereafter, the resultant was neutralized with sodium hydroxide and extracted with ethyl acetate to obtain the target compound mixture. The mixture was separated using column chromatography, and then recrystallized from ethyl alcohol to obtain bis (5- (4-aminophenyl))-2,2'-furyl (PFDA) (yield: 0.2g (20.0%) ).

Mass / e 316 (M ⁺ );

m.p. 203-205 ° C;

¹ H NMR (δ, aceton- d6 ), 7.5 (d, 4H, Ph- H ), 6.72 (d, 4H, Ph- H ), 6.68 (d, 2H, furyl- H ), 6.62 (m, 2H, furyl- H ), 4.88 (s, 4H, NH 2);

Elemental analysis (C ₂₀ H ₁₆ N ₂ ), calcd for C, 75.93; H, 5.09; N, 8.85.

Found: C, 74.45; H, 5.01; N, 9.53

0.5 g (1.58 mmol) of the PFDA and 4.4 g (27.816 mmol) of bromobenzene were dissolved in toluene. Then, at room temperature, 1.8 g (18.96 mmol) of hydroxide tert-butoxide (Na-O'-Bu, sodium tert-butoxide), tris (dibenzylideneacetone) dipalladium (Pd ₂ (dba) ₃ , {Tris (dibenzylidene acetone) ) dipalladium)} 0.075 g (0.079 mmol) and 0.1 g (0.474 mmol) of tritert-butyl phosphine (P (t-Bu) ₃ and Tri-tert-butyl phosphine) synthesize | combined by the synthesis example were added sequentially. Then, the temperature of the reaction vessel was maintained at 100 ℃, which was reacted for 24 hours. The obtained target compound liquid mixture was extracted with dichloromethane and water, and the dichloromethane layer was concentrated under reduced pressure. The resultant was then separated using column chromatography (developing solvent: 20% CH ₂ Cl ₂ / hexane) to give bis (5- (N, N-diphenyl aminophenyl) -2-furyl) (PFDA-PPh ₄ ) was obtained (yield: 0.7 g (71%)).

Mass (EI, m / e) 620.32 (M ⁺ );

M.P. 212.7 ° C .;

IR spectrum (KBr pellet): Aromatic = CH Stretching vibration: 3033cm ^-1 , Tertiary amine N (Ar) ₂ Stretching vibration: 2923, 2852, 1314cm ^-1 , C = C Stretching vibration (Aromatic) : 1586, 1501 cm ^-1 ; CO stretching vibration: 1289cm ^-1 , Aromatic = CH Bending (Monosubst.Benzene) 1015, 782, 695cm ^-1

¹ H-NMR (δ, C ₆ D ₆ ), 7.53-7.50 ppm (4H, d, Ar-H), 7.12-7.03 ppm (20H, m, Ar-H), 6.88-6.84 ppm (4H, bt, Ar-H), 6.62 ppm (2H, d, furyl-H), 6.35 ppm (2H, d, furyl-H);

¹³ C-NMR (δ, C ₆ D ₆ ), 153.8 ppm (furyl-O- C =), 148 ppm (furyl-O- C =), 147.6 ppm (Ar-C), 146.3 ppm (Ar-C) , 125.3 ppm (Ar-C), 124 ppm (Ar-C), 124.9 ppm (Ar-C), 129.6 ppm (Ar-C), 123.4 ppm (Ar-C), 107.7 ppm (furyl-OC = C- ), 106.4 ppm (furyl-OC = C- );

Elemental Analysis (C ₄₄ H ₃₂ N ₂ O ₂ ): Calculated: C, 85.14; H, 5.20; N, 4.51.

Found: C, 85.37; H, 5. 48; N, 4.49

Example 2. Synthesis of 2,2'-bis (furyl) benzidine {2,2'-bis (furyl) benzidine} (FurylBz) and bis (N, N-diphenyl) -1,1'-biphenyl- 2,2'-furyl-4,4'-diamine (FurylBZ-PPh ₄ Manufacture).

10 g (72.5 mmol) of meta-nitroaniline was dissolved in a mixed solution of hydrochloric acid and water, and then the temperature of the dimixed solution was adjusted to 0-5 ° C. using an ice bath. Then, while stirring the mixture, to this was slowly added 6 g (85 mmol) of NaNO ₂ in 20 ml of water.

Thereafter, the reaction mixture was stirred for about 30 minutes, and then 16 g (140 mmol) of NaBF ₄ were added all at once and stirred for 1 hour. The solid produced from the reaction mixture was then filtered to give a white powder. The powder was washed with water, ethanol and ethyl ether in this order to give compound (5) (yield: 97.8% (16.7 g)).

7.5 g (31.6 mmol) of the compound (5) was dissolved in 30 ml of purified pure furan under a nitrogen atmosphere, and the reaction vessel was stirred for 30 minutes in an ice bath to maintain a temperature of 0-5 ° C in the reaction vessel. Subsequently, while stirring the reaction mixture vigorously, the solution which diluted 6.3 ml of triethylamines to 20 ml of furan was slowly thrown in here. After the addition of the furan solution of triethylamine, excess hexane was quickly added to the reaction mixture. The resulting mixture was separated using column chromatography, and then recrystallized from a mixed solvent of ethanol and water to obtain compound (6) (X = O) (yield: 3.8 g (63.6%)).

3.4 g (18 mmol) of the compound (6) (X = O) synthesized above was dissolved in n-propyl alcohol, and 2.9 g (72 mmol) of sodium hydroxide was added thereto in 20 ml of water, followed by 2.3 g of zinc powder ( 36 mmol) was added and the reaction mixture was refluxed for one day.

Upon completion of the reaction mixture, the reaction mixture was filtered hot and the filtrate was extracted with chloroform and recrystallized from tetrachloroethane to give azobenzene compound (7) (X = O) (yield: 2.7 g (55.1%) ).

6.0 g (19.0 mmol) of the azobenzene compound (7) (X = O) was dissolved in 200 ml of acetone under a nitrogen atmosphere, 20 ml of saturated aqueous NH ₄ Cl solution and 12.0 g of zinc powder were added together, and vigorously shaken until the red color disappeared. Filtration with 10% ammonia water gave Hydrazo compound (8) (X = O) as a solid solid.

0.6 g (1.8 mmol) of the hydrazo compound (8) (X = O) was dissolved in 30 ml of ethyl alcohol under a nitrogen atmosphere, and the temperature of the reaction vessel was adjusted to 0-5 ° C. using an ice bath. Subsequently, 15 ml of an ethyl alcohol / hydrochloric acid solution (volume ratio = 1: 1) was slowly added to the reaction mixture over 1 hour and stored in a cold place for one day. The resultant was neutralized with sodium hydroxide and extracted with chloroform to obtain the target compound mixture. The mixture was separated by column chromatography and recrystallized from a mixed solvent of ethyl alcohol and water to obtain 2,2'-bis (furyl) benzidine {2,2'-bis (furyl) benzidine} (FurylBz) (yield: 0.12 g (21.0%)).

m.p. 156-157 ° C;

1 H NMR (δ, aceton- d 6 ), 7.37 (d, 2H, furyl- H), 7.25 (d, 2H, Ph- H ), 6.84 (d, 2H, Ph- H ), 6.67 (dd, 2H, Ph H ), 6.17 (dd, 2H, furyl- H), 5.42 (d, 2H, furyl- H ), 4.78 (s, 4H, N H ₂ );

Elemental analysis (C ₂₀ H ₁₆ N ₂ ) calculated; C, 75.93; H, 5.09; N, 8.85.

Found: C, 75.71; H, 4.87; N, 9.50

0.5 g (1.58 mmol) of FurylBz and 4.4 g (27.816 mmol) of bromobenzene were dissolved in toluene. Then, at room temperature, 1.8 g (18.96 mmol) of sodium tert-butoxide (Na-O'-Bu), tris (dibenzylideneacetone) dipalladium (Pd ₂ (dba) ₃ , Tris (dibenzylidene acetone) dipalladium) 0.075 g (0.079 mmol) and 0.1 g (0.474 mmol) of tritert-butyl phosphine (P (t-Bu) ₃ , Tri-tert-butyl phosphine) synthesized according to the synthesis example were added in this order. The temperature of the reaction vessel was maintained at 100 ° C., and the reaction was carried out for 24 hours, after which the obtained desired compound mixture was extracted with dichloromethane and water, and the dichloromethane layer was concentrated under reduced pressure. CH ₂ Cl ₂ / hexane) to give bis (N, N-diphenyl) -1,1'-biphenyl-2,2'-furyl-4,4'-diamine (FurylBz-PPh ₄ ). (Yield 0.6 g (60%)).

¹ H-NMR (δ, CDCl ₃ ), 7.58 ppm (2H, d, furyl-H), 7.25-6.95 ppm (26H, m, Ar-H), 6.12 ppm (4H, dd, furyl-H), 5.5 ppm (2H, d, furyl-H);

¹³ C-NMR (δ, CDCl ₃ ), 152.8 ppm (furyl-O- C =), 148.3 ppm (Ar-C), 148.0 ppm (furyl-O- C =), 142.0 ppm (Ar-C), 133.1 ppm (Ar-C), 132.4 ppm (Ar-C), 131.5 ppm (Ar-C), 130.0 ppm (Ar-C), 125.0 ppm (Ar-C), 123.6 ppm (Ar-C), 123.5 ppm ( Ar-C) 121.8 ppm (Ar-C) 112.0 ppm (furyl-OC = C- ) 109.2 ppm (furyl-OC = C- )

The visible light absorption spectrum and the emission spectrum of the PFDA, FurylBZ, PFDA-PPh ₄ , FurylBZ-PPh ₄ prepared in Examples 1 and 2 were measured. At this time, the measurement method is as follows, and the measurement results are as shown in Table 1 and FIG. 3.

The PFDA, FurylBZ, PFDA-PPh ₄ , FurylBZ-PPh ₄ compounds were dissolved in 1,4-dioxane (1,4-dioxane) and measured in the liquid phase. The quantum efficiency for fluorescence was 25 ° C. 1N H ₂ SO ₄ Measured relative to the quantum efficiency of quinine sulfate in the solvent (fl = 0.57, 348 nm excitation).

division Absorption wavelength (nm) Excitation wavelength (nm) Emission wavelength (nm) Quantum efficiency PDFA 376 380 415, 440 0.92 Furylbz 328 328 434 0.52 PFDA-PPh ₄ 400 397 436, 464 0.73 FurylBZ-PPh ₄ 298 299 436 0.41

As can be seen from Table 1, the compounds of PFDA, FurylBZ, PFDA-PPh ₄ , FurylBZ-PPh ₄ prepared according to Examples 1 and 2 were confirmed to emit fluorescence in the blue region, quantum efficiency characteristics Was also good.

Application Example 1: Fabrication of Organic Electroluminescent Device

An ITO electrode was formed on the glass substrate, and then N, N'-bis (3-methylphenyl) -N, N'-diphenyl- [1,1'-biphenyl] -4,4'-diamine on top of this. (TPD) was vacuum deposited to form a hole transport layer with a thickness of 500 mm3.

Subsequently, FurylBz prepared according to Example 1 was vacuum deposited on the hole transport layer to form a light emitting layer having a thickness of 280 Å.

Thereafter, the compound of Formula 5 was vacuum deposited on the emission layer to form an electron transport layer having a thickness of 350 Å. An organic electroluminescent device was fabricated by simultaneously depositing Al and Li on the electron transport layer to form an aluminum / lithium electrode having a thickness of 1500 mW.

Application Example 2: Fabrication of Organic Electroluminescent Device

An organic electroluminescent device was completed in the same manner as in Application Example 1, except that FurylBz-PPh ₄ of Example 2 was used instead of FurylBz of Example 1.

In the organic electroluminescent devices manufactured according to Application Examples 1 and 2, the light emission efficiency, driving start voltage, and luminance characteristics were investigated.

As a result, the organic electroluminescent devices of Application Examples 1 and 2 could realize blue color, and it was confirmed that the luminous efficiency, driving start voltage, and luminance characteristics were excellent.

The compound of Formula 1 is a material emitting blue fluorescence, which is very useful as a hole transport layer, an electron transport layer, or a light emitting layer forming material of an organic electroluminescent device. Therefore, the use of the compound of Formula 1 may improve the performance, such as luminous efficiency, driving start voltage, brightness of the organic electroluminescent device. In addition, the compound of the formula (1) is applicable as a coloring material of various display elements.

Claims (8)

Blue light emitting compound represented by Formula 1: <Formula 1> In the above formula, X is -O-, -S-, -NH-, -NCH _3- , -NCH ₂ CH _3- , -NCH ₂ (CH ₂ ) _n CH _3- , -NCOOCH _3- , n is an integer from 1 to 20 Y1, Y2, Y3 and Y4 are independently selected from the group consisting of phenyl group, alkylphenyl group, biphenyl group, alkylbiphenyl group, naphthyl group and alkylnaphthyl group. The method of claim 1, wherein And Y1, Y2, Y3 and Y4 are phenyl groups, wherein the blue light-emitting compound of formula (1) is characterized in that the compound. A method for preparing a blue light emitting compound of Formula 1, wherein the compound of Formula 2 or Formula 3 is obtained by aryl amination or alkylaryl amination reaction. <Formula 2> <Formula 3> <Formula 1> In the above formula, X is -O-, -S-, -NH-, -NCH _3- , -NCH ₂ CH _3- , -NCH ₂ (CH ₂ ) _n CH _3- , -NCOOCH _3- , n is an integer from 1 to 20 Y1, Y2, Y3 and Y4 are independently selected from the group consisting of phenyl group, alkylphenyl group, biphenyl group, alkylbiphenyl group, naphthyl group and alkylnaphthyl group. The method of claim 3, wherein And Y1, Y2, Y3 and Y4 are phenyl groups. The blue color of the formula (1) according to claim 3, wherein the aryl amination or alkylaryl amination reaction is performed in the presence of tert-butoxide hydroxide, tris (dibenzylideneacetone) dipalladium and tritertbutylphosphine. Method for preparing a light emitting compound. In an organic electroluminescent device comprising an organic film provided between a pair of electrodes, The organic electroluminescent device according to claim 1, wherein the organic layer comprises a blue light emitting compound represented by Chemical Formula 1. <Formula 1> In the above formula, X is -O-, -S-, -NH-, -NCH _3- , -NCH ₂ CH _3- , -NCH ₂ (CH ₂ ) _n CH _3- , -NCOOCH _3- , n is an integer from 1 to 20 Y1, Y2, Y3 and Y4 are independently selected from the group consisting of phenyl group, alkylphenyl group, biphenyl group, alkylbiphenyl group, naphthyl group and alkylnaphthyl group. The organic electroluminescent device according to claim 6, wherein the organic film is a hole transport layer, an electron transport layer or a light emitting layer. A display device comprising the blue light emitting compound of formula 1 according to any one of claims 1 to 5 as a coloring material.