WO2006065105A1

WO2006065105A1 - Compounds and organic electroluminescence display device comprising the same

Info

Publication number: WO2006065105A1
Application number: PCT/KR2005/004354
Authority: WO
Inventors: Jong-Wook Park; Ji-Hoon Lee
Original assignee: Doosan Corporation
Priority date: 2004-12-17
Filing date: 2005-12-16
Publication date: 2006-06-22
Also published as: KR100613810B1; KR20060069089A

Abstract

The present invention relates to compounds that include a monomer having predetermined formulae, oligomers thereof, and polymers thereof applicable to any one of a hole injection layer (HIL), a hole transport layer (HTL), an emitting layer (EML), an electron transport layer (ETL), and an electron injection layer (EIL) of an organic electroluminescence display device.

Description

TITLE OF THE INVENTION

COMPOUNDS AND ORGANIC ELECTROLUMINESCENCE DISPLAY DEVICE

COMPRISING THE SAME

BACKGROUND OF THE INVENTION

(a) Field of the Invention

The present invention relates to compounds for an electroluminescence light-emitting device and an organic electroluminescence display device including the same, and more particularly, to compounds applicable to any one of a hole injection layer (HIL), a hole transport layer (HTL), an emitting layer (EML), an electron transport layer (ETL) and an electron injection layer (EIL) of an organic electroluminescence display device and a highly efficient organic electroluminescence display device including the same.

(b) Description of the Related Art

These days, as development within the information and communication industry is accelerated, higher performance display devices are required. Such display devices may be classified into luminescence types and non-luminescence types. For the former devices, a Cathode Ray Tube (CRT), an Electroluminescence Display (ELD), a Light Emitting Diode (LED), a Plasma

Display Panel (PDP), etc., are exemplified.

For the latter devices, a Liquid Crystal Display (LCD), etc., are exemplified. The luminescence type and non-luminescence type display devices have the same basic characteristics such as working voltage, consumption power, brightness, contrast, response time, lifetime and color display, etc. However, liquid crystal display devices, which have largely been used up till now, have some problems in terms of response time, contrast, and viewing angle among the basic characteristics described above. Displays using a luminescence diode are anticipated as next generation display devices that can solve the problems of liquid crystal displays since they have a much shorter response time, do not require a backlight due to having self-luminescence properties, and they also have improved brightness, etc.

An electroluminescence diode has difficulties in application to a large area electroluminescence display device because an inorganic material with crystalline form is mainly used. Furthermore, in the case of an electroluminescence display device using an inorganic material, there are disadvantages that more than 200 V of driving voltage is required and that it is expensive. Active researches on electroluminescence display devices comprising organic materials have been undertaken since the Eastman Kodak Company firstly disclosed a device made from a material having a π-conjugated molecular structure in 1987. In the case of organic materials, there are advantages that a synthetic pathway is relatively simpler and various forms of materials can be synthesized and thus color tuning is easier. On the contrary, organic materials have disadvantages in that crystallization by heat occurs due to low mechanical strength. Organic materials used in an electroluminescence display device are classified into low molecular organic materials and polymeric materials. For low molecular organic materials diamine, diamine derivatives, such as N,N'-bis- (4- methylphenyl)-N,N'-bis(phenyl)benzidine (TPD), etc., perylene tetracarboxylic acid derivatives, oxadiazole derivatives, 1 ,1 ,4,4-tetraphenyl-1 ,3-butadiene (TPB), etc., are exemplified.

SUMMARY OF THE INVENTION

The aspect of the present invention is to provide compounds for an electroluminescence display device that can be applied to any one of a hole injection layer (HIL), a hole transport layer (HTL), an emitting layer (EML), an electron transport layer (ETL), and an electron injection layer (EIL) of an electroluminescence display device.

Another aspect of the present invention is to provide an electroluminescence display device having a low driving voltage, various color developments, and a short response time. The present invention provides monomers represented by the following formulae 1 to 3, oligomers thereof, or polymers thereof for an electroluminescence display device:

(Chemical Formula 2)

(Chemical Formula 3)

wherein, X₁ to X₆ are independently N or CR' and at least one of Xi and X₂, at least one of X₃ and X₄, and at least one of X₅ and X₆ are N₁ where R' is selected from the group consisting of hydrogen, a substituted or unsubstituted linear or branched alkyl, a substituted or unsubstituted cycloalkyl, a substituted or unsubstituted alkenyl, a substituted or unsubstituted alkynyl, a substituted or unsubstituted alkoxy, a substituted or unsubstituted aryl, and a substituted or unsubstituted heteroaryl,

R₁ to R₁₈ are independently selected from the group consisting of hydrogen, deuterium, halogen, -CN, -NO₂, a substituted or unsubstituted linear or branched alkyl, a substituted or unsubstituted cycloalkyl, a substituted or unsubstituted alkenyl, a substituted or unsubstituted alkoxy, a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, substituted unsubstituted carbazole, substituted or unsubstituted phenothiazine, substituted or unsubstituted phenoxazine, substituted or unsubstituted phenoxathin, substituted or unsubstituted acridine, substituted or unsubstituted phenazasiline, substituted or unsubstituted 9-aza-IO-germa-anthracene, SiR₁₉R₂oR2i. OR₂₂, NR₂₃R₂₄, and SR₂₅,

Rig to R₂₅ are independently selected from the group consisting of hydrogen, a substituted or unsubstituted linear or branched alkyl, a substituted or unsubstituted cycloalkyl, a substituted or unsubstituted alkenyl, a substituted or unsubstituted alkynyl, a substituted or unsubstituted alkoxy, a substituted or unsubstituted aryl, and a substituted or unsubstituted heteroaryl.

Another aspect of the present invention is to provide an electroluminescence device that includes the above compounds in any one or all of a hole injection layer, a hole transport layer, an electroluminescent layer, an electron transport layer, and an electron injection layer (EIL).

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view of an organic electroluminescence display device according to the present invention.

FIG. 2 shows a UV-Vis spectrum of the compounds of chemical formula 16 according to Example 3.

FIG. 3 shows a PL spectrum of the compounds of chemical formula 16 according to Example 3.

FIG. 4 shows an EL spectrum of the compounds of chemical formula 16 according to Example 3. DETAILED DESCRIPTION OF THE INVENTION

The compounds in accordance with the present invention can be applied to any one of a hole injection layer, a hole transport layer, an emitting layer, an electron transport layer, and an electron injection layer of an electroluminescence (EL) device. The compounds are monomers represented by the above formulae 1 to 3, oligomers thereof, or polymers thereof. The compounds may be applied as host materials or dopants to a limiting layer due to improved light-emitting properties.

The compounds of the present invention for an electroluminescence device include a compound represented by the chemical formulae 1 to 3, or oligomers thereof, or homopolymers or copolymers thereof.

In the above formulae 1 to 3, X₁ to X₆ are independently N or CR' wherein

R' is selected from the group consisting of hydrogen, a unsubstituted linear or branched alkyl, a cycloalkyl, an alkenyl, an alkynyl, an alkoxy, an aryl, and a heteroaryl, and at least one of X₁ and X₂, at least one of X₃ and X₄, and at least one of X₅ and X₆ are N. Preferably, X₁ to X₆ are all nitrogen. In the above formulae 1 to 3, Ri to R₁₈ are independently selected from the group consisting of hydrogen, deuterium, halogen, -CN, -NO₂, a substituted or unsubstituted linear or branched alkyl, a substituted or unsubstituted cycloalkyl, a substituted or unsubstituted alkenyl, a substituted or unsubstituted alkoxy, a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, substituted or unsubstituted carbazole, substituted or unsubstituted phenothiazine, substituted or unsubstituted phenoxazine, substituted or unsubstituted phenoxathin, substituted or unsubstituted acridine, substituted or unsubstituted phenazasiline, substituted or unsubstituted 9-aza-10-germa-anthracene, SiRi₉R₂₀R_2I, OR22, NR₂₃R₂₄, and SR₂₅. The substituent may include at least one substituent selected from the group consisting of an alkyl, an alkoxy, a cycloalkyl, an alkenyl such as - CH=CH-R₂₆ (wherein R₂₆ is selected from the group consisting of hydrogen, a substituted or unsubstituted linear or branched alkyl, a substituted or unsubstituted cycloalkyl, a substituted or unsubstituted alkenyl, a substituted or unsubstituted alkynyl, a substituted or unsubstituted alkoxy, a substituted or unsubstituted aryl, and a substituted or unsubstituted heteroan aryl), an alkynyl, an aryl, a heteroaryl, a halogen such as F, Cl, Br, or I, aliphatic amine, aromatic amine, and an aryloxy.

In the present invention, substituted or unsubstituted linear or branched alkyl, cycloalkyl, or alkoxy have C1 to C12 alkyl or alkoxy, and preferably C1 to C7 of a lower alkyl or alkoxy. The cycloalkyl may be preferably a C3 to C12 cycloalkyl, and more preferably a C3 to C8 cycloalkyl. The alkenyl may be preferably a C2 to C8 alkenyl, and more preferably a C2 to C4 alkenyl.

The alkynyl may be preferably a C2 to C8 alkynyl, and more preferably a C2 to C4 alkynyl. The aryl may be preferably a C4 to C30 aryl, more preferably a C4 to C20 aryl, and more preferably a C4 to C12 aryl. The heteroaryl may be preferably a C4 to C30 heteroaryl, more preferably a C4 to C20 heteroaryl, and still more preferably a C4 to C12 heteroaryl that includes 1 to 3 heteroatoms, such as N, S, P, or O₁ in an aromatic ring. The substituted alkyl, alkoxy, cycloalkyl, alkenyl, alkynyl, aryl, and heteroaryl means that at least one hydrogen thereof is substituted with an alkyl, a cycloalkyl, an alkoxy, an alkenyl, an alkynyl, an aryl, a heteroaryl, a halogen such as F, Cl, Br or I, aliphatic amine, aromatic amine, or an aryloxy.

In the present invention, oligomers, homopolymers, or copolymers prepared from the monomers represented by the chemical formulae 1 to 3 may be used. The oligomers or polymers may be represented by the following formulae 4 (Chemical Formula 4)

(Chemical Formula 5)

(Chemical Formula 6)

In the above formulae 4 to 6, X₁ to X₆, R₃ to R₆, R₉ to R₁₂, and R₁₅ to R₁₈ are the same as in the above formulae 1 to 3, and n, m, and I are respectively in the range from 1 to 10000, and preferably 1 to 1000. In the case of oligomers, n, m, and I are respectively in the range of 1 to 10, and in the case of polymers, n, m, and I are respectively in the range of 1 to 1000.

The oligomers or copolymers may be prepared through a solution polymerization of the monomers of the chemical formulae 1 to 3 using a metal catalyst such as Ni (O), Pd (O), etc. The catalyst may be Ni(COD)₂ [Bis (1 ,5- cyclooctadiene)nickel (O)], Pd(Ph₃J₄ (tetrakis(triphenylphosphine)palladium(O)),

PdCI₂ (palladium (II) chloride], FeCI₃ (iron (III) chloride), and so on.

In the above formulae 1 to 3, the compound may be polymerized with a compound of the following formulae 7 to 8. The above polymerization reaction is generally carried out using a Yamamoto or Suzuki coupling reaction. (Chemical Formula 7)

X₇-Ar-X₈

(Chemical Formula 8)

wherein, in the above formulae, Ar is a substituted or unsubstituted aromatic group, or a heteroaromatic group including at least one heteroatom in an aromatic ring, X₇ and X₈ are a reactive functional group such as a halogen, borate, boronic acid (BOOH), and OTf. X₇ and X₈ may be selected from the group consisting of hydrogen, an unsubstituted linear or branched alkyl, a cycloalkyl, an alkenyl, an alkynyl, an alkoxy, an aryl, and a heteroaryl. The carbon number thereof is defined as above. When X₇ and X₈ are not a reactive functional group, an oxidant or a reducing agent may be added during the polymerization reaction.

The aromatic group may be a C4 to C30 aromatic group, and preferably a

C4 to C20 aromatic group, and the heteroaromatic group may be a C4 to C14 heteroaromatic group. The aromatic or heteroaromatic group may have a substituent of a C1 to 12 alkyl, alkoxy, or amine. The Ar may be as follows:

wherein, in the above formulae, R is hydrogen, a C1 to C12 linear, branched, or cyclic alkyl or alkoxy, or a C4 to 20, preferably C4 to C14 aromatic group. The aromatic group may have a substituent selected from the group consisting of a C1 to C12 alkyl, an alkoxy, or amine, and X₉ is selected from the group consisting of N, O, S₁ and Si.

At least one monomer of the chemical formulae 1 to 3 and a monomer of the chemical formula 7 or 8 may be used in a mole ratio of 1 : 0.01 to 100, and preferably 1 : 0.05 to 20.

The compounds according to the present invention are applied between an anode made from indium tin oxide (ITO) having a large work function, which injects holes, and a cathode made from metals having various work functions, such as aluminum, lithium fluoride/aluminum, copper, silver, calcium, gold, magnesium, etc., an alloy of magnesium and silver, and an alloy of aluminum and lithium, which injects electrons. The compounds are applicable to any one of a hole injection layer (HIL), a hole transport layer (HTL), an emitting layer (EML), an electron transport layer (ETL), and an electron injection layer (EIL) of an electroluminescence display device

FIG. 1 shows the sectional structure of an electroluminescence display device, where an anode 2 is formed on a substrate 1 by coating an anode material. The substrate 1 includes a material, such as a glass, a plastic, quartz, a ceramic, or silicon, which has transparency, a flat-surface, and water-repellency and is easy to handle, but is not limited thereto. The anode material may include transparent and high conductive indium tin oxide (ITO), indium zinc oxide (IZO), tin oxide (SnO₂), zinc oxide (ZnO) and so on. A buffer layer exists to compensate the surface of the anode 2 and helps the injection and flow of holes. Materials used as the buffer are exemplified by high molecular materials such as doped polyaniline (PANI) and doped polyethylenedeoxythiopene (PEDOT) and low molecular materials such as alpha- CuPc. A thin film having a thickness from 20 nm to 150 nm was formed by spin coating PANI and PEDOT. Alternatively, a thin film having thickness from 20 nm to 100 nm might be formed by vacuum-deposition of alpha-CuPc.

A hole injection layer (HIL) 3 is formed on the anode or the buffer layer by coating a hole injection material using vacuum thermal deposition, or a spin coating method. Examples of the hole injection material are not particularly limited, but CuPc or a starburst-type amine such as TCTA, m-MTDATA, m-MTDAPB and so on, can be used.

A hole transport layer (HTL) 4 may be formed on the hole injection layer 3 using vacuum thermal deposition or spin coating. The hole transport layer is formed using a material such as N,N'-bis (3-methylphenyl)-N,N'-diphenyl-[1 ,1- biphenyl]-4,4'-diamine (TPD), N,N'-bis(naphthalene-1-yl)-N,N'-diphenyl- benzidine

(α-NPB) and so on.

An emitting layer (EML) 5 is formed on the hole transport layer 4 using vacuum thermal deposition or spin coating of an electroluminescence material. On the emitting layer 5, an electron transport layer (ETL) 6 is formed using vacuum deposition or spin coating. The electron transport layer 6 may include a material such as AIq₃ or Bu-PBD.

An electron injection layer (EIL) 7 may optionally be formed on the electron transport layer 6, but is not limited to specific materials. Examples of a material suitable for the electron injection layer (EIL) 7 may include LiF, NaCI, CsF, Li₂O, BaO and so on. Then, a cathode is formed on the electron injection layer (EIL) 7 by coating a cathode metal using vacuum thermal deposition to fabricate an organic EL device. The cathode may include a metal such as lithium (Li), magnesium (Mg), aluminum (Al), aluminum-lithium (Al-Li), calcium (Ca), magnesium-indium (Mg-In)₁ magnesium-silver (Mg-Ag), and so on. A front light- emitting device may be obtained by using a light-permeable cathode which contains ITO, IZO, and so on.

The compounds are applicable to any one of the hole injection layer 3, the hole transport layer 4, the emitting layer 5, the electron transport layer 6 and the electron injection layer 7 of an EL display device The compounds of the present invention can be used as a host material or as a dopant in an emitting layer. When the compound is used as a host material, it may be used with dopants such as organic compounds having conjugated double bonds. The dopants are organic compounds having conjugated double bonds and materials which have a smaller energy gap than the doped material and thus a lower maximum wavelength value than the doped material, and good energy transfer and chromophore property. For the dopants, at least one compound selected from the group consisting of dicarbazolyl azobenzene (DCAB), fluorenyl diacetylene (FDA), perylene, carbazole, carbazole derivatives, coumarine compounds, and 4-(dicyanomethylene)-2-methyl-6-(1 ,1 ,7,7-tetramethyljulodinyl-9- enyl)-4H-pyran (DCJT) may be used.

The dicarbazolyl azobenzene (DCAB) has the chemical formula 9. (Chemical Formula 9)

The fluorenyl diacetylene (FDA) has the chemical formula 10.

(Chemical Formula 10)

wherein, in the above formulae R₂₆ and R₂₇ are independently selected from the group consisting of hydrogen, an alkyl, an aryl, cycloalkyl, and acetyl. The perylene has the chemical formula 11. (Chemical Formula 11)

The 4-(dicyanomethylene)-2-methyl-6- (1 ,1 ,7,7-tetramethyljulodinyl-9- enyl)-4H-pyran has the chemical formula 12. (Chemical Formula 12)

For the coumarines compounds, coumarine 6 (manufactured by EXCITON Corp.) having the chemical formula 13 may be preferably used. (Chemical Formula 13)

The dopants may have more than one substituent to obtain desirable properties such as crystallization degree, thermal stability, solubility, etc.

Dicarbazolyl azobenzene (DCAB), fluorenyl diacetylene (FDA), perylene, carbazole, and carbazole derivatives serve as blue dopants, coumarines compounds as green dopants, and 4-(dicyanomethylene)-2-methyl-6- (1 ,1,7,7- tetramethyljulodinyl-9-enyl)-4H-pyran serves as red dopant. A combination of more than one dopant may be used. When the compound is used as a dopant, the conventional chromophore materials may be used.

The amount of said dopants is preferably 0.1 to 30 % by weight, more preferably 5 to 30 % by weight, and most preferably 5 to 10 % by weight, based on the amount of low molecular compounds.

Examples

Hereinafter, preferred embodiments of the present invention will be described. However, these are presented only for better understanding of the present invention and the present invention is not limited thereto. Compounds of the following Examples 1 to 9 were synthesized through a reaction scheme 1.

(Reaction Scheme 1 )

1) 1 βq NBS/ DBP cat. in CCI₄ reflux for 15 min-10h

2) 2 Bq NaN₃/ DMSO

X = H compound "a" 1a/1b 2a/2b X = Br compound "b"

5a : X = H and R = CH₃ 6a : X = H and R = CH₃ 7a : X = H Sb : X = Br and R = CH₃ 6b : X = Br and R = CH₃ 7b : X = Br 5c : X = Br and R = C₈H₁₇ 6c : X = Br and R = C₈H₁₇

Example 1: Synthesis of a compound represented by chemical formula 14

(5a).

(Chemical Formula 14)

i) Synthesis of 2-bromo-indan-1-one Ma)

25 g of 1-indanon (189 mmol), 33.6 g (189 mmol) of N-bromo succin imide, and a small amount of dibenzoyl peroxide were added into a 500 ml flask and agitated at a temperature ranging from 50 to 60 ^°C for two hours. The mixed solution was turned into a deep yellow as the reaction proceeded. When the reaction was complete, the solution was cooled down to room temperature and filtered under a reduced pressure and thereafter, succin imide was removed. The resulting filtrate was concentrated, and column chromatography (CHCI₃ : n-Hexane

= 1 : 1 ) was performed thereto, obtaining 33g of a yellow liquid resulting product. The yield of the resulting product was about 82%. ¹H NMR (CDCI₃) : δ 7.82 (1 H, d, J=7.5Hz), 7.65 (1H₁ 1, J=7.8Hz), 7.42 (2H₁ dt, J=7.8Hz), 4.63 (1 H, dd, J=7.5, 3.3Hz), 3.82 (1H₁ dd, J=18, 7.8Hz), 3.40 (1H, dd, J=18.3, 3Hz) ii) Synthesis of 2-Azido-indan-1-one (2a)

15 g (71 mmol) 2-bromo-indan-1-one was dissolved into 200 ml of DMSO in a 500 ml flask, and thereafter, another solution gained by dissolving 5.54 g (85.2 mmol) of azide into 200 ml of DMSO was slowly added to the former solution in a dropwise fashion. As the sodium azide solution was added, the resulting solution in the flask changed from yellow to dark brown. The solution product was agitated at room temperature for 2 hours, and thereafter, an extraction was performed thereto by using water and ether. An organic layer gained from the extraction was concentrated, obtaining 10.7 g of a dark brown liquid resulting product. The yield of the resulting product was about 87%. ¹H NMR (CDCI₃) : d 7.79 (1H, d,

J=7.5Hz), 7.65 (1H, t, J=9Hz), 7.45 (2H, m), 4.32 (1H, dd, J=9, 6Hz), 3.51 (1 H, dd, J=18, 8.1 Hz), 2.93 (1H, dd, J=18, 4.5Hz) iii) Synthesis of 6.12-dihvdrodiindenof1.2-b:1.2-elpyrazine (3a) 3 g (17.4 mmol) of 2-azido-indan-1-one and 0.28 g (1.74 mmol) of AIBN were dissolved in 300 ml of benzene in a 500 ml flask, and thereafter, 6.1 g (21 mmol) of tributyltin hydride was added thereto. Then, the resulting solution was refluxed for a reaction while agitating under a nitrogen atmosphere for 24 hours. As the reaction proceeded, the solution turned into a light red. The reaction solution was concentrated, and thereafter, recystallization was performed in ethanol, obtaining 0.6 g of a solid product. The product had a strong fluorescent blue. The yield of the resulting product was about 27%. ¹H NMR (CDCI₃) : δ 8.1 (2H, d, J=7.2Hz), 7.61 (2H, d, J=6Hz), 7.46 (4H, q, J=6.6Hz), 4.04 (4H, s) iv) Synthesis of a compound represented by chemical formula 14 (5a)

3 g (11.7 mmol) of 6,12-dihydrodiindeno[1 ,2-b:1 ,2-e]pyrazine and 7.3 g (4.4eq, 51.48 mmol) of CH₃I were dissolved in 50ml of toluene, and thereafter, 0.19 g (0.59 mmol) of tetrabutyl ammonium bromide (TBAB) was added thereto. 4.68 g (117 mmol) of NaOH was dissolved into 25 ml of water, and thereafter, this resulting solution was added to the former solution. Then, the resulting mixed solution was refluxed for two days. An extraction was performed by using water and CHCI₃ to obtain an organic layer. The organic layer was dried by using

MgSO₄ and thereafter, concentrated. A silica gel column was performed to the organic layer, obtaining 3.44g of a product represented by the chemical formula 14

(5a). The yield of the resulting product was about 94%. The structure of the compound was identified through a ¹H-NMR. m/z : 312.16, a CHN elemental analysis C : 84.60, H : 6.44, N : 8.97.

Example 2: Synthesis of a compound represented by chemical formula 15 (6a).

(Chemical Formula 15)

i) Synthesis of 10,11-diaza-trans-fluoreacendion (4a)

0.5 g (1.95 mmol) of 6,12-dihydrodiindeno[1 ,2-b:1 ,2-e]pyrazine was dissolved into 50ml of acetic acid, and thereafter, 1.16 g (3.9 mmol) of Na₂Cr₂O₇ was added thereto little by little. Then, the resulting solution was refluxed and agitated under a nitrogen atmosphere for 12 hours. As the reaction proceeded, the strong blue fluorescent solution became less fluorescent. After the reaction solution was cooled down to room temperature, it was several times washed by using a cold methanol while filtering it under a reduced pressure. Then, it was dried, obtaining 0.36g of product. The yield of the product was about 65%. ¹H- NMR (CDCI₃) : δ 8.02 (2H, d, J=4.5Hz), 8.85 (2H, d, J=4.5Hz), 7.72 (2H, t, J=4.5Hz), 7.55 (2H, d, J=4.5Hz) ii) Synthesis of a compound represented by chemical formula 15 (6a)

2 g (21.4 mmol) phenol and 0.3 g (2.2 mmol) of ZnCI₂ were added to 1.51 g (5.3 mmol) of 10,11-diaza-trans-fluoreacendion. Dry HCI was flown into the solution for a reaction at 60"C for two hours. After another two hours, the solution was agitated at 60⁰C for an hour. After one hour, the reaction solution was washed with toluene, obtaining 2.98g of an intermediate. The yield was about

90%. 2.98 g (4.8 mmol) of the gained intermediate compound was dissolved into 100 ml of acetone, and 2 g (14.7 mmol) of K₂CO₃, 2.09 g (14.7 mmol) of CH₃I, and 0.4 g (2.45 mmol) of Kl were added thereto. Then, the mixture was refluxed for 2 days. When the reaction was complete, an extraction was performed by using water and CHCI₃ to remove K₂CO₃. A resulting organic layer was dried by using

MgSO₄ and thereafter, concentrated, so that it could be turned into a solid. Then, the solid product was purified with train sublimation equipment. In this way, 2.61 g of the compound represented by chemical formula 15 was obtained. The yield of the compound was about 80%. The structure of the gained compound was identified through a ¹H-NMR. m/z: 680.27, a CHN elemental analysis: C : 81.14,

H : 5.34, N : 4.09.

Example 3: Synthesis of a compound represented by chemical formula 16 (7a)

(Chemical Formula 16)

i) Synthesis of a hetero double spiro compound (7a) represented by chemical formula 16 1.5O g (5.3 mmol) of 10,11-diaza-trans-fluoreacendion and 4.92 g (21 mmol) of 2-bromobiphenyl were heated under a vacuum atmosphere to completely remove moisture. The moisture-free 2-bromobiphenyl was dissolved in 300 ml of anhydrous THF, and thereafter, the solution was maintained at a temperature of - 78 °C by using dry ice and acetone. Then, 21 mmol of t-BuLi was slowly added to the solution and thereafter, maintained at -78 ^°C under a nitrogen atmosphere for 30 minutes. In addition, the moisture-free 10,11-diaza-trans-fluoreacendion was added to 1000 ml of anhydrous THF. Then, this solution was slowly added to the above 2-bromobiphenyl solution. When the reaction was complete, the solution was concentrated, and column chromatography (CHCI₃ : EA = 5 : 1 ) was performed thereto, obtaining 1.0 g of diol as an intermediate. The yield was about

32%. The purfied 1.0 g of diol was slowly added to 200 ml of acetic acid, and 20 to 30 drops of conc-HCI were added thereto. The resulting product was refluxed and agitated under a nitrogen atmosphere for 2 to 3 hours. When the reaction was complete, the solution was filtered under a reduced pressure, and the resulting solid was several times washed by using cold methanol, gaining 500 mg of product.

The yield of the product was about 53%. ¹H-NMR (CDCI₃) : δ 7.93 (4H, d, J=4.5Hz), 7.87 (2H, d, J=4.5Hz), 7.44 (4H, t, J=4.5Hz), 7.27 (2H, t, J=4.5Hz), 7.27 (6H, t, J=4.5Hz), 6.79 (4H, d, J=4.5Hz), 6.74 (2H, d, J=4.5) Examples 4 to 6 (Reaction Scheme 2)

Compounds represented by the following formulae 17 to 19 (5b, 6b, and 7b in reaction scheme 1 ) were synthesized in the same method as in Examples 1 to 3 except that 5-bromo-2,3-dihydroinden-1-one instead of 2,3-dihydroinden-i-one was used as a starting material. The structure of the compound products was identified trough ¹H-NMR. Other compounds represented by chemical formulae 20 to 22 (5d, 6d, and 7d in reaction scheme 2) were synthesized from the compounds represented by the above formulae 17 to 19 in a Pd (O)-mediated Suzuki Aryl Coupling method

(refer to reaction scheme 2). For example, the synthesis of the compound represented by the chemical formula 20 is as follows:

3.0 g (6.38 mmol) of a compound represented by the chemical formula 17, 4.08 g (2.1 eq., 13.4 mmol) of 2-(anthracen-9-yl)-4,4,5,5-tetramethyl-1,3,2- dioxaborolane as an anthracene borate derivative, and 1 mol% (73.7 mg) of Pd(PPh₃)₄ were dissolved into 30 ml_ of anhydrous toluene, and 30 mL of THF, and thereafter, 16 mL (5eq) of K₂CO₃ was added thereto. Then, they were reacted at 100 ^°C for 36 hours. When the reaction was complete, an extraction was performed by using water and ethylacetate. Then, after drying it, recrystallization was performed in diethyl ether and chroloform, gaining 3.61 g of a resulting product. The yield of the resulting product was about 85%. The structure of the produced compound was identified through a ¹H-NMR. m/z : 664.29 in a chemical formula 20, a CHN elemental analysis C : 90.25, H : 5.46, N : 4.18.; m/z : 1032.39 in a chemical formula 21 , a CHN elemental analysis C : 86.00, H : 5.06, N : 2.70.; m/z : 909.08 in a chemical formula 22, a CHN elemental analysis C : 92.43, H : 4.43, N : 3.09.

(Chemical Formula 17)

(Chemical Formula 18) H₃

(Chemical Formula 19)

(Chemical Formula 20)

(Chemical Formula 21)

(Chemical Formula 22)

Examples 7 to 9

Other compounds represented by the following formulae 23 to 25 (5e, 6e, and 7e in reaction scheme 2) were synthesized from the compounds represented by the above formulae 17 to 19 (5b, 6b, and 7b in a reaction scheme 1) in a Pd (O)- mediated C-N Aryl Coupling method. For example, the synthesis of a compound represented by the chemical formula 24 is as follows. 1.34 g (1.6 mmol) of a compound represented by the chemical formula 18, 0.65 g (3.3 mmol) of di-p- tolylamine, 0.059 g (0.64 x 10^"4 mol)of Pd₂(dba)_3l and 0.465 g (4.835 mmol) of t- BuONa were added in a 100 mL-round flask under a nitrogen atmosphere, and thereafter, 40 ml. of anhydrous toluene was added thereto. The mixture was slowly heated to 110O by using an oil bath, while agitating it. The reaction mixture was reacted for 46 hours. When the reaction was complete, an extraction was performed to the resulting mixture by using water and CHCI₃. A produced organic layer was washed using 500 ml. of a hydrochloric acid aqueous solution with 1N. After the organic solvent was removed under a reduced pressure, a resulting solid was purifed using train sublimation equipment. In this way, 1.25 g of a compound representd as the chemical formula 24 was gained. The yield of the resulting product was about 70%. The structure of the compound was identified through a ¹H-NMR. m/z : 1118.57 of the chemical formula 24, a CHN elemental analysis 24, C : 82.61 , H : 6.64, N : 4.97.; m/z : 734.43 of the chemical formula 23, a CHN elemental analysis C : 84.95, H : 7.40, N : 7.61.; m/z : 902.34 of the chemical formula 24, a CHN elemental analysis C : 89.12, H : 4.67, N : 6.21.

(Chemical Formula 23)

(Chemical Formula 24)

(Chemical Formula 25)

Examples 10 to 11: Synthesis of a polymer i) Synthesis of a dibromo monomer compound (5c and 6c in reaction scheme 1 ) substituted for a long alkyl group Compounds represented by chemical formulae 26 and 27 (5c and 6c in reaction scheme 1 ) were synthesized in the same method as in Examples 4 to 6 i) except that n-octyl bromide was used instead of an alkyl halide CH₃. The structure of the produced compound was identified through a ¹H-NMR. m/z : 862.42 of the chemical formula 26, a CHN elemental analysis C : 69.58, H : 8.64, N : 3.23.; m/z : 1230.52 of the chemical formula 27, a CHN elemental analysis C : 72.18, H : 7.35, N : 2.28. ii) Synthesis of polymer I and polymer Il

These polymers were synthesized in a generally-known Ni (O)-mediated Yamamoto Aryl coupling method. A representative method of synthesizing the polymer I can be described as follows: a 50 ml-Schlenk flask was several times vacuumed and treated by using nitrogen to completely remove moisture. 305 mg (1.09 mmol) of Ni(COD)₂ and 172 mg (1.09 mmol) of 2,2'-bipyridyl were added in the flask, and thereafter, the flask was several times vacuumed and treated by using nitrogen. Then, 5 ml of anhydrous DMF, 118 mg (0.14 mmol) of COD, and 5 ml of anhydrous toluene were added to the mixed solution under a nitrogen atmosphere. The resulting mixture was agitated at 80 V. for 30 minutes. Then, 552 mg (0.64 mmol) of a compound represented by chemical formula 26 as a starting material was diluted in 5 ml of toluene and thereafter, added to the agitated mixture. 5ml of the rest of toluene was also added to the mixture, washing the material on the wall of the flask, and thereafter, the entire mixture was agitated at

80⁰C for 4 days. Then, 1ml of bromo pentafluoro benzene as an end copper was added to the mixture, and the resulting mixture was agitated again at 80 °C for about a day. When the reaction was complete, the mixture was cooled down to a temperature of 60 ^°C , and thereafter, an extraction was performed using a HCI : acetone : methanol = 1 : 1 : 2 solution and agitated for 12 hours. The precipitations were filtered. Then, they were melted in a small amount of chloroform, and thereafter, second precipitations were gained. The precipitations were gained with a gravity filter, and thereafter, a solvent extraction was performed with a soxhlet by using methanol and chloroform in order. Finally, the chloroform solution was reconcentrated, and thereafter, a precipitation was performed by using methanol, gaining 315 mg of a polymer product. The yield of the resulting product was about 70%. The structure of the produced compound was identified through a ¹H-NMR. Molecular weight of the polymer I : Mn = 65000, Mw = 121 ,000 ; molecular weight of the polymer Il : Mn = 85,000, Mw = 180,000. (Reaction Scheme 3) Polymer I

Example 12: Synthesis of a polymer

(Reaction Scheme 4)

1-Bormooctane

M-1 M-2

i) Synthesis of a compound M-1

19 g of catechol was dissolved in 200 ml of acetonitrile, and 2.5 eq of 1- bromo octane K₂CO₃ (2.5 eq) and 0.1 eq of Kl were added thereto. Then, the resulting solution was heated and refluxed for 24 hours. When the reaction was complete, the solution was filtered and thereafter, concentrated under a reduced pressure. The residues were redissolved in 200 ml of diethylether, and washed by using distilled water (100ml) and a salt-saturated water (100ml) to separate the organic layer from the solution. Then, the separated organic layer was dehydrated by using 20 g of MgSO₄, and thereafter, the remaining solution was concentrated under a reduced pressure, obtaining 57.17g of a white solid product. The yield of the resulting product was about 99%. The structure of the produced compound was identified through a ¹H-NMR. ii) Synthesis of a compound M-2 57.17 g of M-1 was dissolved in 400 ml of CH₂CI₂, and 1.1 eq of NBS was respectively dissolved in 100 ml of DMF at 0 ⁰C. The latter solution was dropwised into the former solution, and the entire solution was heated to a room temperature and reacted for 2 hours. When the reaction was complete, the reaction solution was twice washed, and a resulting organic layer was washed by using a Na₂S₂O₃ ^■ H₂O solution, a NaHCO₃ saturated solution, and brine in order and treated with Mg₂SO₄, gaining 69.01 g of a compound. The yield of the resulting product was about 98%. The structure of the produced compound was identified through a ¹H-NMR. iii) Synthesis of a compound M-3

69.03 g of M-2 was dissolve into 500 ml of anhydrous THF in a 2 L-sized flask, and thereafter, 1.2 eq of n-BuLi was slowly added thereto in a dropwise fashion. Then, the mixed solution was agitated for 10 minutes, and thereafter, 1.1 eq of 2-lsopropoxy-4,4_I5,5-tetramethyl-1 ,3_I2-dioxaborolane was slowly added thereto in a dropwise fashion at the same temperature. The resulting solution was agitated for one hour. When the reaction was complete, 300 ml of EA and 300 ml of water was added to the reaction solution, and thereafter, an organic layer was separated. The organic layer was washed by using 150 ml of a saturated NaHCO₃ solution and 150 ml of salt water, thereafter, treated with Mg₂SO₄, and filtered. The filtered solution was concentrated under a reduced pressure, obtaining 46.26 g of a compound. The yield of the resulting product was about 60%. The structure of the produced compound was identified through a ¹H-NMR. iv) Synthesis of a compound M-4

46.26 g of M-3 and 1.1 eq of M-2 were dissolved into 300 ml of DME : H₂O = 1.5 : 1 , and 2.5 eq of K₂CO₃ was respectively dissolved into 150 ml of DME : H₂O = 1.5 : 1. The latter solution was added to the former solution in a dropwise fashion, and the mixed solution was heated for one hour and refluxed for a reaction. When the reaction was complete, 300 ml of EA and 200 ml of water were added to the reaction solution to separate an organic layer. The separated organic layer was dehydrated by using 30 g of Mg₂SO₄ and filtered. The filtered solution was concentrated under a reduced pressure. Recrystallization was performed to the concentrated residue in ethanol, obtaining 40.19 g of a compound. The yield of the resulting product was about 60%. The structure of the produced compound was identified through a ¹H-NMR. v) Synthesis of a compound M-5

40.19 g of M-4 was dissolved into 350 ml of CH₂CI₂, and thereafter, the solution was cooled down to 0 °C to 5⁰C. 1.1 eq of NBS was minutely ground and added to the reaction solution. Then, the mixture was left for a reaction at room temperature for two hours. When the reaction was complete, 200 ml of water was added to the reaction solution, and thereafter, the mixed solution was agitated. Then, an organic layer was separated, washed by using 100 ml of a saturated NaHCO₃ solution and 100 ml of salt water, dehydrated by using 30 g of Mg₂SO₄, and thereafter, filtered. The remaining solution was concentrated under a reduced pressure. Then, recrystallization was performed to the concentrated residue using EtOH, gaining 44 g of a compound. The yield of the resulting product was about 98%. The structure of the produced compound was identified through a ¹H-NMR. vi) Synthesis of a dibromo monomer compound

2.21 g (2.96 mmol) of M-5 was dissolved into 50 ml of anhydrous THF, and thereafter, the solution was cooled down to -78 °C. 3.5 ml (1.7 M) of t-BuLi was slowly added to the reaction solution in a dropwise fashion, and the mixed solution was agitated for one hour. Another solution prepared by dissolving 0.654 g (1.48 mmol) of 4b into 30 ml of anhydrous THF was added to the above reaction solution in a dropwise fashion for 30 minutes. When the reaction was complete, the reaction solution was concentrated under a reduced pressure. 50 ml of EA and 50ml of salt-saturated water were added to the concentrated residue to separate an organic layer. The separated organic layer was dehydrated by using 3 g of Mg₂SO₄, and thereafter, filtered. The remaining solution was concentrated under a reduced pressure. A silica gel column was performed to the concentrated residue by using n-hexane : EA = 4 : 1 as a developing solvent, gaining 2.19 g of a compound. The yield of the resulting product was about 85 %. The structure of the produced compound was identified through a ¹H-NMR. m/z : 1739.98 of 7c, a CHN elemental analysis C : 73.15, H : 8.68, N : 1.60. vii) Synthesis of a polymer III

This polymer was synthesized in the same method as in Examples 10 and 11. The structure of a produced compound was identified through a ¹H-NMR. The molecular weight of the polymer III: Mn = 91,000, Mw = 210,000. Luminescence characteristics of a chromophore compound FIGS. 2 and 3 illustrate the UV and PL spectra of a compound with the chemical formula 16. As shown in FIG. 2, the UV-vis spectrum shows an absorption band at 389nm. The band is regarded by a π → π ^* transition of a conjugated double bond. Referring to the PL spectrum, when the excitation wavelength was 338nm, a luminescent color had a maximum blue wavelength of 409nm.

This corresponded to quantum energy of 2.79eV. The UV and PL spectra of the compounds with chemical formulae 14, 20, and 24 were measured, and thereby, blue light-emitting was identified.

Fabrication of an electroluminescence display device Example 13

An ITO layer was formed as an anode on a glass substrate, thereon, MTDATA (4₎4',4"-tris{N-(methylphenyl)-N-phenylamino}triphenylamine) and NPB were vacuum-deposited, and thereon, compounds prepared according to

Examples 1 , 3, 4, and 8 were also vacuum-deposited. Then, AIq₃ was vacuum- deposited on the deposed composition, and thereon, 1 nm of LiF and 200 nm of an aluminum metal were also vacuum-deposited to fabricate a diode. The vacuum deposition was performed at a speed of 1 A/second under a 1 X 10^"6 torr vacuum condition to form a 9 mnf area. The thickness and growing speed of the layer during the depositions were regulated using a layer thickness monitor. Example 14

A transparent electrode substrate coated with ITO (indium-tin oxide) was washed, thereon, an ITO electrode pattern was formed using a photoresist resin and an etchant, and thereafter, the electrode with the ITO pattern was washed again. Then, PEDOT (poly(styrene sulfonate)-doped poly (3,4-ethylenedioxy thiophene : Batron P 4083 made by BAYER Co.) was coated in a thickness of

500A on the washed electrode with the pattern, and thereafter, the resulting product was baked at 180 t: for one hour to form a hole injection layer (HIL). Then, a composition for an electroluminescent layer, which is prepared by dissolving a polymer I prepared according to Example 10 into chlorobenzene, was spin-coated on the hole injection layer, and thereafter, baked at 90 °C for 2 hours in a vacuum oven to completely remove moisture, forming a 800 A-thick electroluminescent layer. Next, Ca and Al in order were deposited to form a 2500- 3000 A-thick cathode while maintaining a vacuum degree of less than 4 X 10^"6 torr, and thereafter, the cathode was encapsulated to complete an organic electroluminescence device. The thickness and growing speed of the Ca and Al layer during the depositions were regulated using a crystal sensor. The organic electroluminescence device had a single layer and a 4 mm² light-emitting area.

Characteristic estimation of an electroluminescence device

Light-emitting diodes including compounds prepared according to Examples 13 and 14 were estimated about I-V and EL characteristics by applying an electric field thereto. FIG. 4 shows the EL characteristics of light-emitting diodes including a compound of the chemical formula 16. The I-V characteristics of the light-emitting diodes were measured using a Keithley SMU238 and a forward bias voltage as a direct current voltage. Brightness of devices and its efficiency were measured using a brightness meter, PR-650.

Table 1 shows the results of turn-on voltage, maximum brightness, Luminous efficiency, and color of the light-emitting diodes including compounds with chemical formulae 14, 16, 20, and 24 and polymers I and III.

Table 1

As shown in Table 1, devices including compounds according to the present invention turned out to have typical diode I -V characteristics and turn- on voltages ranging 3.3 to 4.5 V. On the other hand, the polymers had somewhat lower luminous efficiency compared to that of a low molecular material, but the low luminous efficiency can be improved by copolymerizing the polymers with a monomer having excellent hole or electron transfer characteristics. Next, luminescent colors varied from deep blue to blue ranging 410 to 470 nm. In addition, the devices including compounds according to the present invention turned out to have excellent brightness and luminous efficiency.

According to embodiments of the present invention, organic compounds for an electroluminescent device can be applied to at least one selected from the group consisting of a hole transport layer, a hole injection layer, an electroluminescent layer, an electron injection layer, and an electron transport layer, or all of them. Since the organic compounds of the present invention have excellent hole transport properties and hole injection properties, they can be preferably applied to a hole transport layer and a hole injection layer. In addition, when the compounds of the present invention were applied to an electroluminescent device, the electroluminescent display device emitting blue color can be driven at a low voltage. Furthermore, suitable host or doping materials that are organic compounds with conjugated double bonds may be used along with the compounds to form a good energy transfer device which makes various color realization at low energy possible, and improves the brightness and luminous efficiency.

The simple modifications and changes of the present invention may be made by those skilled in the art, without departing from the scope of the invention.

Claims

WHAT IS CLAIMED IS:

1. A compound for an electroluminescence device comprising at least one selected from the group consisting of monomers represented by the following formulae 1 to 3, oligomers thereof, and polymers thereof:

(Chemical Formula 1)

(Chemical Formula 2)

(Chemical Formula 3)

wherein, X₁ to X₆ are independently N or CR¹ and at least one of X₁ and X₂, at least one of X₃ and X₄. and at least one of X₅ and X₆ are N, where R' is selected from the group consisting of hydrogen, a substituted or unsubstituted linear or branched alkyl, a substituted or unsubstituted cycloalkyl, a substituted or unsubstituted alkenyl, a substituted or unsubstituted alkynyl, a substituted or unsubstituted alkoxy, a substituted or unsubstituted aryl, and a substituted or unsubstituted heteroaryl;

R₁ to R₁₈ are independently selected from the group consisting of hydrogen, deuterium, halogen, -CN₁ -NO₂, a substituted or unsubstituted linear or branched alkyl, a substituted or unsubstituted cycloalkyl, a substituted or unsubstituted alkenyl, a substituted or unsubstituted alkoxy, a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, substituted or unsubstituted carbazole, substituted or unsubstituted phenothiazine, substituted or unsubstituted phenoxazine, substituted or unsubstituted phenoxathin, substituted or unsubstituted acridine, substituted or unsubstituted phenazasiline, substituted or unsubstituted 9-aza-10-germa-anthracene, SiR₁₈R₂oR₂i. OR₂₂, NR₂₃R₂₄, and SR₂₅,

R₁₉ to R₂₅ are independently selected from the group consisting of hydrogen, a substituted or unsubstituted linear or branched alkyl, a substituted or unsubstituted cycloalkyl, a substituted or unsubstituted alkenyl, a substituted or unsubstituted alkynyl, a substituted or unsubstituted alkoxy, a substituted or unsubstituted aryl, and a substituted or unsubstituted heteroaryl.

2. The compound of claim 1 , wherein the oligomers or polymers are represented by the following formulae 4 to 6:

(Chemical Formula 4)

(Chemical Formula 5)

(Chemical Formula 6)

wherein, in the above formulae 4 to 6, X₁ to X₆, R₃ to R₆, R₉ to R₁₂, and R₁₅ to R₁₈ are the same as in the above formulae 1 to 3, and n, m, and I are respectively in the range from 1 to 10000.

3. The compound of claim 1 , wherein the oligomers or polymers comprise a compound represented by the following formulae 7 or 8: (Chemical Formula 7) X₇-Ar-X₈ (Chemical Formula 8)

wherein, in the above formulae, Ar is a substituted or unsubstituted aromatic group, or a heteroaromatic group including at least one heteroatom in an aromatic ring, and X₇ and X₈ are a reactive functional group such as a halogen, borate, boronic acid (BOOH), and OTf.

4. The compound of claim 3, wherein the oligomers or polymers comprise at least one monomer of the chemical formulae 1 to 3 and a monomer of the chemical formula 7 or 8 at a mole ratio of 1 :0.01 to 100.

5. The compound of claim 3, wherein the Ar of the formula 7 or 8 is selected from the group consisting of the following formulae:

wherein, in the above formulae, R is hydrogen, a substituted or unsubstituted linear, branched, or cyclic alkyl or alkoxy, or a substituted or unsubstituted aromatic group, and X₉ is selected from the group consisting of N₁ O₁ S, and Si.

6. An organic electroluminescence display device which comprises the compound according to claim 1 in at least one selected from the group of a hole transport layer, a hole injection layer, an emitting layer, an electron injection layer, and an electron transport layer.

7. The organic electroluminescence display device of claim 6, wherein the emitting layer comprises the compound of claim 1 , and a dopant which is an organic compound having conjugated double bonds and materials which have a smaller energy gap than the doped material, and thus a lower maximum wavelength value than the doped material, and good energy transfer and chromophore properties.

8. The organic electroluminescence display device of claim 6, wherein the emitting layer comprises a dopant comprising the compound according to claim 1.