KR100613810B1 - Compounds and organic electroluminescence display device comprising the same - Google Patents

Abstract

The present invention relates to a compound for an electroluminescent device that can be applied to all of the hole injection layer, hole transport layer, light emitting layer, electron transport layer and the electron injection layer of the organic electroluminescent device, the compound is a monomer having a specific formula, oligomer compounds, And polymers thereof.

Organic EL, coloring compound

Description

A compound for an electroluminescent device and an organic electroluminescent device comprising the same {COMPOUNDS AND ORGANIC ELECTROLUMINESCENCE DISPLAY DEVICE COMPRISING THE SAME}

1 is a view schematically showing a configuration of an organic EL device according to the present invention.

2 is a view showing a UV-Vis spectrum of the compound of Formula 16 prepared according to Example 3.

3 is a diagram showing a PL spectrum of a compound of Formula 16 prepared according to Example 3. FIG.

4 is a diagram showing an EL spectrum of the compound of Formula 16 prepared according to Example 3. FIG.

<Explanation of symbols for main parts of drawing>

1: substrate 2: anode

3: hole injection layer 4: hole transport layer

5: light emitting layer 6: electron transport layer

7: electron injection layer 8: cathode

[Industrial use]

The present invention relates to a compound for an electroluminescent device and an organic electroluminescent device including the same, and more particularly, a hole injection layer, a hole transport layer, a light emitting layer of an organic electroluminescent device (EL Display), A compound that can be applied to both an electron transport layer and an electron injection layer, and a high efficiency organic electroluminescent device including the same.

[Private Technology]

Recently, as the development of the information and communication industry is accelerated, higher performance is required in the field of display devices, which is one of the most important fields. Such displays can be divided into luminescent and non-luminescent. Cathode ray tubes (CRTs), electroluminescent scene displays (ELDs), electroluminescent diodes (LEDs), and plasma display panels (PDPs) include have. Non-light emitting displays include liquid crystal displays (LCDs).

The light emitting and non-light emitting displays have basic performances such as operating voltage, power consumption, brightness, that is, brightness, contrast, response speed, lifetime, and display color. However, among these, liquid crystal displays, which are widely used to date, have problems in response speed, contrast, and visual dependence among the above basic performances. The display using the light emitting diode has a fast response time and is self-luminous, so it does not need a back light, has excellent brightness, and has various advantages. It is expected to be able to occupy.

The light emitting diode is mainly difficult to apply to a large area electroluminescent device because an inorganic material having a crystalline form is used. In addition, in the case of an electroluminescent device using an inorganic material, a driving voltage is required to be 200 V or more, and a price is also disadvantageous. However, since 1987, when Eastman Kodak Co. published a device made of a material having a ??-conjugated structure called alumina quinone, research into electroluminescent devices using organic materials has been actively conducted. In the case of organic materials, the synthesis route is simple, so that various types of materials can be easily synthesized, and thus color tuning is possible. However, crystallization by heat is low due to low mechanical strength.

Organic materials used in the electroluminescent device are classified into low molecular weight organic materials and high molecular weight organic materials. Low molecular organic materials include diamine, N, N'-bis- (4-methylphenyl) -N, N'-bis (phenyl) benzidine (N, N'-bis- (4-methylphenyl) -N, N'-bis diamine derivatives such as (phenyl) benzidine; TPD), perylene tetracarboxylic acid derivatives, oxadiazole derivatives, and 1,1,4,4-tetraphenyl-1,3-butadiene (TPB).

An object of the present invention is to provide a compound for an EL device that can be applied to all of the hole injection layer, hole transport layer, light emitting layer, electron transport layer and the electron injection layer of the EL device.

Another object of the present invention is to provide an organic electroluminescent device which is driven at a low voltage, can implement various colors, and has a fast response speed.

The present invention provides a compound for an electroluminescent device comprising a monomer of any one of formulas 1 to 3, oligomeric compounds thereof, and polymers thereof in order to achieve the above object:

[Formula 1]

[Formula 2]

[Formula 3]

Wherein X ₁ to X ₆ are each independently N or CR ′, wherein R ′ is hydrogen, unsubstituted straight or branched chain alkyl group, cycloalkyl group, alkenyl group, alkynyl group, alkoxy group, aryl group, and hetero Selected from the group consisting of aryl groups), at least one of X ₁ and X ₂ , at least one of X ₃ and X ₄ , at least one of X ₅ and X ₆ is N,

R ₁ to Each R ₁₈ is independently hydrogen, deuterium, halogen, -CN, -NO ₂ , a substituted or unsubstituted linear or branched alkyl group, a substituted or unsubstituted linear or branched alkyl group, a substituted or unsubstituted cycloalkyl group , Substituted or unsubstituted alkenyl group, substituted or unsubstituted alkoxy group, substituted or unsubstituted aryl group, substituted or unsubstituted heteroaryl group, substituted or unsubstituted carbazole, substituted or unsubstituted Phenothiazine, substituted or unsubstituted phenoxazine, substituted or unsubstituted phenoxathiin, substituted or unsubstituted acridine, substituted or unsubstituted phenazillin ( phenazasiline), substituted or unsubstituted 9-aza-10-germa-anthracene, SiR ₁₉ R ₂₀ R ₂₁ , OR ₂₂ , NR ₂₃ R ₂₄ and SR ₂₅ , and

R ₁₉ to Each R ₂₅ is independently selected from hydrogen, a substituted or unsubstituted linear or branched alkyl group, a cycloalkyl group, an alkenyl group, an alkynyl group, an alkoxy group, an aryl group, and a heteroaryl group.

The present invention also provides an electroluminescent device in which the compound is applied to any one or both of a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer and an electron injection layer.

Hereinafter, the present invention will be described in detail.

The compound of the present invention is any one of the monomers of Formulas 1 to 3, oligomer compounds thereof, and these, which can be applied to all of the hole injection layer, hole transport layer, light emitting layer, electron transport layer and electron injection layer of the EL device, and these It is an organic compound which is a polymer of. The compound may be used in the light emitting layer is excellent in the light emitting properties. That is, the light emitting layer may be used as a host or a dopant.

The compound for an electroluminescent device of the present invention is a compound represented by formulas (1) to (3) or oligomers or homopolymers or copolymers thereof.

In Formulas 1 to 3, X ₁ to X ₆ are each independently N or CR ′ (wherein R ′ is (wherein R ′ is hydrogen, an unsubstituted linear or branched alkyl group, a cycloalkyl group, an alkenyl group, Alkynyl group, alkoxy group, aryl group, and heteroaryl group) selected from the group consisting of at least one of X ₁ and X ₂ , at least one of X ₃ and X ₄ , at least one of X ₅ and X ₆ More preferably, one is N and all are nitrogen.

In Formulas 1 to 3 R ₁ to Each R ₁₈ is independently hydrogen, deuterium, halogen, -CN, -NO ₂ , a substituted or unsubstituted linear or branched alkyl group, a substituted or unsubstituted linear or branched alkyl group, a substituted or unsubstituted cycloalkyl group , Substituted or unsubstituted alkenyl group, substituted or unsubstituted alkoxy group, substituted or unsubstituted aryl group, substituted or unsubstituted heteroaryl group, preferably substituted or unsubstituted carbazole, substituted or Unsubstituted phenothiazine, substituted or unsubstituted phenoxazine, substituted or unsubstituted phenoxathiin, substituted or unsubstituted acridine, substituted or unsubstituted pena Phenazasiline, substituted or unsubstituted 9-aza-10-germa-anthracene, SiR ₁₉ R ₂₀ R ₂₁ , OR ₂₂ , NR ₂₃ R ₂₄ and SR ₂₅ . The substituent is an alkyl group, an alkoxy group, a cycloalkyl group, -CH = CH-R ₂₆ (wherein R ₂₆ is hydrogen, a substituted or unsubstituted straight or branched chain alkyl group, cycloalkyl group, alkenyl group, alkynyl group, alkoxy group, At least one selected from the group consisting of alkenyl groups, alkynyl groups, aryl groups, heteroaryl groups, halogens, aliphatic amines, aromatic amines and aryloxy groups such as F, Cl, Br, or I; It can be one.

As the substituted or unsubstituted linear or branched alkyl, cycloalkyl or alkoxy group in the present invention, alkyl or alkoxy having 1 to 12 carbon atoms is preferable, and lower alkyl or alkoxy having 1 to 7 carbon atoms is more preferable. As said cycloalkyl group, C3-C12 is preferable and a C3-C8 cycloalkyl group is more preferable. As the alkenyl group, an alkenyl group having 2 to 8 carbon atoms is preferable, and an alkenyl group having 2 to 4 carbon atoms is more preferable. As an alkynyl group, a C2-C8 alkynyl group is preferable and a C2-C4 alkynyl group is more preferable. The aryl group is preferably an aryl group having 4 to 30 carbon atoms, more preferably an aryl group having 4 to 20 carbon atoms, even more preferably an aryl group having 4 to 12 carbon atoms. The heteroaryl group is preferably a heteroaryl group having 4 to 30 carbon atoms containing 1 to 3 heteroatoms of N, S, P, Si or O in the aromatic ring, more preferably a heteroaryl group having 4 to 20 carbon atoms. Even more preferred are heteroaryl groups of 4 to 12. Substituted alkyl group, alkoxy group, cycloalkyl group, alkenyl group, alkynyl group, aryl group, and heteroaryl group, at least one of these hydrogen is alkyl group, cycloalkyl group, alkoxy group, alkenyl group, alkynyl group, aryl group, heteroaryl group Or substituted with halogen, aliphatic amine, aromatic amine or aryloxy group such as F, Cl, Br or I.

In the present invention, oligomers, homopolymers, or copolymers prepared by using the compounds represented by Chemical Formulas 1 to 3 as monomers can also be preferably used. The oligomers or polymers of the single monomers are represented by the following formulas 4-6:

[Formula 4]

[Formula 5]

[Formula 6]

In Chemical Formulas 4 to 6, X ₁ to X ₆ and R ₃ to R ₆ , R ₉ to R ₁₂ and R ₁₅ to R ₁₈ is the same as in Chemical Formulas 1 to 3, and n, m and l are each preferably in the range of 1 to 10000, and more preferably in the range of 1 to 1000. In the case of oligomers, n, m and l are preferably in the range of 1 to 10, and in the case of polymers, n, m and l are preferably in the range of 1 to 1000.

The oligomer or copolymer may be prepared by solution polymerization using a compound of Formulas 1 to 3 as a monomer and a metal catalyst such as Ni (0) or Pd (O). The catalysts include Ni (COD) ₂ [Bis (1,5-cyclooctadiene) nickel (0)], Pd (Ph ₃ ) ₄ [Tetrakis (triphenylphosphine) palladium (0)], PdCl ₂ [Palladium (II) chloride] , FeCl ₃ [Iron (III) chloride] or the like can be used.

In the polymerization of the compounds of Formulas 1 to 3, the compounds of Formulas 7 to 8 may be prepared by polymerization together. Generally, these polymerizations can be made using Yamamoto or Suzuki polymerization.

[Formula 7]

X ₇ -Ar-X ₈

[Formula 8]

Wherein Ar is a substituted or unsubstituted aromatic group or heteroaromatic group containing at least one heteroatom in an aromatic ring, and X ₇ and X ₈ are each independently a reactive functional group, preferably halogen, Borate, Boronic acid (BOOH), and OTf. X ₇ and X ₈ may also be selected from the group consisting of hydrogen, unsubstituted straight or branched chain alkyl groups, cycloalkyl groups, alkenyl groups, alkynyl groups, alkoxy groups, aryl groups, and heteroaryl groups. Their carbon number may be defined as described above. When X ₇ and X ₈ are not reactive functional groups, the polymerization reaction may proceed by adding an oxidizing agent or a reducing agent.

The aromatic group is preferably an aromatic group having 4 to 30 carbon atoms, more preferably an aromatic group having 4 to 20 carbon atoms, and the heteroaromatic group is preferably a heteroaromatic group having 4 to 14 carbon atoms, and the aromatic group or heteroaromatic group has 1 carbon atom. One or more alkyl, alkoxy or amine groups of 12 to 12 may be substituted. Preferred examples of Ar are as follows.

Wherein R is a hydrogen atom, a linear, branched or cyclic alkyl group or alkoxy group having 1 to 12 carbon atoms, or an aromatic group having 4 to 20 carbon atoms, preferably 4 to 14 carbon atoms, and the aromatic group having 1 to 12 carbon atoms It may have a substituent selected from the group consisting of an alkyl group, an alkoxy group or an amine group, X ₉ is selected from the group consisting of N, O, S, and Si.

The molar ratio of at least one of the monomers of the formulas (1) to (3) and the monomers of the formulas (7) and (8) is preferably adjusted to 1: 0.01 to 100, more preferably 1: 0.05 to 20.

The compound according to the present invention is a positive electrode for injecting holes made of ITO (indium tin oxide) having a large work function, and metals of various work functions such as aluminum, lithium fluoride / aluminum, copper, silver, calcium, gold, magnesium, and the like. And an anode for injecting electrons made of an alloy of magnesium and silver and an alloy of aluminum and lithium. The compound of the present invention can be applied to any one or both of a hole injection layer, a hole transport layer, an electron transport layer, an electron injection layer, an electron transport layer of the electroluminescent device.

1 illustrates a structure of an electroluminescent device, and forms an anode 2 by coating an anode material on a substrate 1. The substrate 1 may be a material such as glass, plastic, quartz, ceramic, or silicon, which is excellent in transparency, surface smoothness, ease of handling, and waterproofness, but is not limited thereto. It is preferable to use indium tin oxide (ITO), indium zinc oxide (IZO), tin oxide (SnO 2), zinc oxide (ZnO), or the like, which is transparent and has excellent conductivity.

A buffer layer may be formed on the anode 2 to compensate the surface of the anode and to aid in the injection and flow of holes. The material used as a buffer may be a doped polyaniline (PANI) and a doped polyethylene dioxythiophene (PEDOT) as a polymer material and alpha-CuPc as a low molecular material. PANI and PEDOT make thin films in the range of 20 nm to 150 nm by spin coating and alpha-CuPc makes thin films in the range of 20 nm to 100 nm by vacuum deposition.

The hole injection layer (HIL) 3 is formed by vacuum thermal vapor deposition or spin coating the hole injection layer material on the anode or the anode on which the buffer layer is formed. The hole injection layer material is not particularly limited, and CuPc or Starburst type amines TCTA, m-MTDATA, and m-MTDAPB may be used as the hole injection layer 3.

Vacuum heat deposition or spin coating on the hole injection layer 3 to form a hole transport layer (HTL) (4). The hole transport layer material is not particularly limited, and 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'-bis (naphthalene-1-yl) -N, N'-diphenyl-benzidine: α-NPB) Etc. are used.

The light emitting layer (EML) 5 is formed on the hole transport layer 4 by vacuum thermal vapor deposition or spin coating. An electron transport layer (ETL) 6 is formed on the light emitting layer by vacuum deposition or spin coating. Alq ₃ or Bu-PBD may be used as the electron transport layer material.

In addition, an electron injection layer (EIL) 7 may be selectively stacked on the electron transport layer 6, which does not particularly limit the material. As the electron injection layer forming material, materials such as LiF, NaCl, CsF, Li ₂ O, and BaO may be used. Then, the organic EL device is completed by forming a cathode by vacuum thermal evaporation of a metal for forming a cathode on the electron injection layer. The metal for forming the cathode may be lithium (Li), magnesium (Mg), aluminum (Al), aluminum-lidium (Al-Li), calcium (Ca), magnesium-indium (Mg-In), magnesium-silver ( Mg-Ag) and the like are used. In addition, a transmissive cathode using ITO and IZO may be used to obtain a front light emitting device.

The compound of the present invention can be applied to any of the hole injection layer 3, the hole transport layer 4, the light emitting layer 5, the electron transport layer 6 and the electron injection layer 7 of the organic EL element. In particular, it can be preferably applied to the hole injection layer 3 and the hole transport layer (4).

The compound of the present invention can be used as a host or a dopant in the light emitting layer. When the compound is used as a host, it may be used in combination with a dopant such as an organic compound having a conjugated double bond. The dopant is an organic compound having a conjugated double bond, and has a lower energy gap than the doped material, so that the maximum wave device is smaller than the doped material, has a good energy transfer, and has a chromophore characteristic. Examples of the dopant include dicarbazolyl azobenzene (DCAB), fluorenyldiacetylene (FDA), perylene, carbazole, carbazole derivatives, coumarin-based compounds and 4- (dicyanomethylene) -2-methyl -6- (1,1,7,7-tetramethylzolodinyl-9-enyl) -4H-pyran (4- (dicyanomethylene) -2-methyl-6- (1,1,7,7-tetramethyljulodinyl- At least one compound selected from the group consisting of 9-enyl) -4H-pyran; DCJT) can be used.

The dicarbazolyl azobenzene (DCAB) has the formula

[Formula 9]

The fluorenyldiacetylene (FDA) has the formula

[Formula 10]

In the formula, R ₂₆ and R ₂₇ are each independently selected from the group consisting of hydrogen, an alkyl group, an aryl group, a cycloalkyl group, and an acetyl group.

The perylene has the formula

[Formula 11]

Said 4- (dicyanomethylene) -2-methyl-6- (1,1,7,7-tetramethylzolodinyl-9-enyl) -4H-pyran has the following formula 12:

[Formula 12]

As the coumarin compound, coumarin 6 (manufactured by Exciton) having the following Chemical Formula 13 may be preferably used.

[Formula 13]

The dopant may have one or more substituents in order to obtain required physical properties such as crystallinity, thermal stability, and solubility.

Dicarbazolyl azobenzene (DCAB), fluorenyldiacetylene (FDA), perylene (carylene), carbazole and carbazole derivatives are blue dopants, and coumarin compounds are green dopants. , 4- (dicyanomethylene) -2-methyl-6- (1,1,7,7-tetramethylzolodinyl-9-enyl) -4H-pyran is used as a red dopant. One or more of the above dopants may be mixed and used.

When the compound of the present invention is used as a dopant, all conventional coloring materials may be used.

The amount of the dopant is preferably used in an amount of 0.1 to 30% by weight, more preferably 5 to 30% by weight, and most preferably 5 to 10% by weight, based on the total amount of the coloring compound and the dopant. desirable.

EXAMPLE

Hereinafter, a preferred embodiment of the present invention. However, the following examples are only presented to aid the understanding of the present invention, and the present invention is not limited to the following examples.

The reaction for synthesizing the compound of Examples 1 to 9 is shown in Scheme 1 below.

Scheme 1

Example 1  Synthesis of Chemical Formula 14 (5a)

[Formula 14]

i) Synthesis of 2-bromo-indan-1-one (1a)

To a 500 ml flask, 25 g (189 mmol) of 1- indanone, 33.6 g (189 mmol) of N- bromosuccimide and a small amount of dibenzoylperoxide were added, followed by stirring at 50 to 60 ° C. for 2 hours. As the reaction proceeded, the color of the solution turned dark yellow. After the reaction was completed, the temperature was cooled to room temperature and filtered under reduced pressure to remove succimide. The filtrate under reduced pressure was concentrated and column chromatography (CHCl ₃ : n-Hexane = 1: 1) was carried out to obtain 33 g (82%) of an off-white liquid product. ¹ H NMR (CDCl ₃ ): d 7.82 (1H, d, J = 7.5 Hz), 7.65 (1H, t, J = 7.8 Hz), 7.42 (2H, dt, J = 7.8 Hz), 4.63 (1H, dd , J = 7.5, 3.3 Hz), 3.82 (1H, dd, J = 18, 7.8 Hz), 3.40 (1H, dd, J = 18.3, 3 Hz)

ii) Synthesis of 2-Azido-indan-1-one (2a)

After dissolving 15 g (71 mmol) of 2-bromo-indan-1-one in 200 ml of DMSO in a 500 ml flask, a solution of 5.54 g (85.2 mmol) of sodium azide in 200 ml of DMSO was slowly added dropwise. As the sodium azide solution was added, the color of the solution changed from yellow to dark brown. After stirring at room temperature for 2 hours, extraction was performed using water and ether. The organic layer obtained after extraction was concentrated to give 10.7 g (87%) of a dark brown liquid product. ¹ H NMR (CDCl ₃ ): d 7.79 (1H, d, J = 7.5 Hz), 7.65 (1H, t, J = 9 Hz), 7.45 (2H, m), 4.32 (1H, dd, J = 9, 6 Hz ), 3.51 (1H, dd, J = 18, 8.1 Hz), 2.93 (1H, dd, J = 18, 4.5 Hz)

iii) Synthesis of 6,12-Dihydrodiindeno [1,2-b: 1,2-e] pyrazine (3a)

In a 500 ml flask, 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, followed by addition of 6.1 g (21 mmol) of tributyltin hydride. It was stirred at reflux. As the reaction proceeded, the solution appeared light red. The reaction solution was concentrated and recrystallized in ethanol to obtain 0.6 g (27%) of a brown solid product, which showed a strong blue fluorescence. ¹ H NMR (CDCl ₃ ): d 8.1 (2H, d, J = 7.2 Hz), 7.61 (2H, d, J = 6 Hz), 7.46 (4H, q, J = 6.6 Hz), 4.04 (4H, s)

iv) Synthesis of Compound of 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 CH ₃ I were dissolved in 50 ml of toluene and TBAB (tetrabutyl ammonium bromide) 0.19 g (0.59 mmol) was added. 4.68 g (117 mmol) of NaOH was dissolved in 25 ml of water, and the solution was added thereto and refluxed for 2 days. After the reaction was extracted with water and CHCl ₃ and the organic layer was dried over MgSO ₄ and concentrated to pass through a silica gel column to obtain 3.44 g (94%) of the product, the compound of formula 14 (5a). The structure of the resulting compound was confirmed by ¹ H-NMR. m / z: 312.16, CHN elemental analysis C: 84.60, H: 6.44, N: 8.97.

Example 2 Synthesis of Compound of Formula 15 (6a)

[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 in 50 ml of acetic acid, followed by the addition of 1.16 g (3.9 mmol) of Na ₂ Cr ₂ O ₇ in small portions. Stirring under reflux under nitrogen stream for 12 hours. It can be seen that as the reaction proceeds, the strong blue fluorescence disappears. The reaction solution was cooled to room temperature, and then filtered under reduced pressure and washed several times with cold methanol. 0.36 g (65%) of product can be obtained after drying under reduced pressure filtration. ¹ H-NMR (CDCl ₃ ): d 8.02 (2H, d, J = 4.5 Hz), 8.85 (2H, d, J = 4.5 Hz), 7.72 (2H, t, J = 4.5 Hz), 7.55 (2H, d, J = 4.5 Hz)

ii) Synthesis of Compound of Formula 15 (6a)

To 1.51 g (5.3 mmol) of 10,11-Diaza-trans-fluoreacendion, 2 g (21.4 mmol) of phenol and 0.3 g (2.2 mmol) of ZnCl ₂ were added. The reaction is carried out for 2 hours while flowing dry HCl at 60 ° C. After 2 hours, stirring was carried out again at 60 ° C. for 1 hour. After 1 hour, the reaction was washed with toluene to obtain 2.98 g (90%) of intermediate. 2.98 g (4.8 mmol) of the obtained intermediate compound was dissolved in 100 ml of acetone, followed by addition of 2 g (14.7 mmol) of K ₂ CO _3, 2.09 g (14.7 mmol) of CH ₃ I, and 0.4 g (2.45 mmol) of KI for 2 days. Reflux. After the reaction was completed, extraction with water and CHCl ₃ to remove the K ₂ CO _3. The organic layer was dried over MgSO ₄ , concentrated to form a solid, and finally purified using a train sublimation apparatus. 2.61 g (80%) of the compound of formula 15 were obtained. The structure of the resulting compound was confirmed by ¹ H-NMR. m / z: 680.27, CHN elemental analysis: C: 81.14, H: 5.34, N: 4.09.

Example 3:  Synthesis of Compound of Formula 16 (7a)

[Formula 16]

i) Synthesis of Hetero double Spiro Compound (7a) of Formula 16

1.50 g (5.3 mmol) of 10,11-Diaza-trans-fluoreacendion and 4.92 g (21 mmol) of 2-bromobiphenyl were added under vacuum to remove water completely. 2-bromobiphenyl, which had been completely removed, was dissolved in 300 ml of anhydrous THF, and the temperature was kept at -78 ° C using dry ice and acetone. Then, 21 mmol of t- BuLi was added slowly and the temperature was reached at -78 ° C for 30 minutes. And nitrogen atmosphere were maintained. Moisture removed 10,11-Diaza-trans-fluoreacendion was added to 1000 ml of dry THF, and then slowly added to the solution containing 2-bromobiphenyl. After the reaction was completed, the solution was concentrated and subjected to column chromatography (CHCl ₃ : EA = 5: 1) to obtain 1.0 g (32%) of an intermediate diol. 1.0 g of the purified diol was added to 200 ml of acetic acid, followed by addition of 2 to 30 drops of conc-HCl, followed by stirring under reflux for 2 to 3 hours. After completion of the reaction, filtration under reduced pressure and the solids were washed several times with cold methanol to obtain 500 mg (53%) of the product. ¹ H-NMR (CDCl ₃ ): d 7.93 (4H, d, J = 4.5 Hz), 7.87 (2H, d, J = 4.5 Hz), 7.44 (4H, t, J = 4.5 Hz), 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 4-6

Scheme 2

The starting materials were used in the same manner as in Example 1-3 except that 5-bromo-2,3-dihydroinden-1-one was used instead of 2,3-dihydroinden-1-one. At 5b, 6b, 7b) were synthesized. The structure of the resulting compound was confirmed by ¹ H-NMR.

Compounds of formulas 20 to 22 (5d, 6d and 7d in Scheme 2) were synthesized from the compounds of formulas 17 to 19 using Pd (0) -mediated Suzuki Aryl Coupling method (see Scheme 2).

As a representative example, the synthesis of the compound of formula 20 is as follows. 3.0 g (6.38 mmol) of the compound of formula 17 and 4.08 g (2.1 eq., 13.4 mmol) of anthracene Borate derivative 2- (anthracen-9-yl) -4,4,5,5-tetramethyl-1,3,2-dioxaborolane ), And Pd (PPh ₃ ) ₄ 1 mol% (73.7 mg) was dissolved in anhydrous toluene (30 mL) and THF (30 mL), followed by the addition of 2M K ₂ CO ₃ 16 mL (5eq) at 36 ° C. The reaction was time. After the reaction was completed, the mixture was extracted with water and ethyl acetate, dried, and recrystallized from diethyl ether and chloroform to obtain 3.61 g (85%) of the product. The structure of the resulting compound was confirmed by ¹ H-NMR. M / z of Chemical Formula 20: 664.29, CHN Elemental Analysis C: 90.25, H: 5.46, N: 4.18 .; M / z of Chemical Formula 21: 1032.39, CHN Elemental Analysis C: 86.00, H: 5.06, N: 2.70 .; M / z of Chemical Formula 22: 909.08, CHN Elemental Analysis C: 92.43, H: 4.43, N: 3.09.

[Formula 17]

[Formula 18]

[Formula 19]

[Formula 20]

[Formula 21]

[Formula 22]

Examples 7-9

Synthesis of the compounds of Formulas 23 to 25 (5e, 6e, and 7e in Scheme 2) using Pd (0) -mediated CN Aryl Coupling method from the compounds of Formulas 17 to 19 (Scheme 1, 5b, 6b, and 7b) It was. As a representative example, for example, the synthesis of Chemical Formula 24 is as follows. 1.34 g (1.6 mmol) of a compound of Formula 18, 0.65 g (3.3 mmol) of di- p- tolylamine, 0.059 g (0.64 x 10 ^-4 mol) of Pd ₂ (dba) ₃ , 0.465 g (4.835 mmol) of t- Buona, And ( t -Bu) ₃ P 0.016 g (0.81 x 10 ^-4 mol) was added to a 100 mL round bottom flask under nitrogen atmosphere and 40 mL of anhydrous toluene. Slowly raise the temperature while stirring to 110 ℃ using an oil bath. The reaction mixture is reacted for 48 hours. After the reaction was completed, the work-up was performed using water and CHCl ₃ , and the organic layer was washed well with 500 mL of 1 N hydrochloric acid. After removing all organic solvents under reduced pressure, the obtained solid was purified using a train sublimation apparatus. About 1.25 g (70%) of the compound of formula 24 was obtained. The structure of the resulting compound was confirmed by ¹ H-NMR. M / z of Formula 24: 1118.57, CHN elemental analysis C: 82.61, H: 6.64, N: 4.97 .; M / z of Chemical Formula 23: 734.43, CHN elemental analysis C: 84.95, H: 7.40, N: 7.61 .; M / z of Chemical Formula 24: 902.34, CHN Elemental Analysis C: 89.12, H: 4.67, N: 6.21.

[Formula 23]

[Formula 24]

[Formula 25]

Example 10-11 : Synthesis of Polymer

i) Synthesis of Dibromo Monomer Compounds Formulas 26 and 27 with Substituted Long Alkyl Groups (5c and 6c in Scheme 1)

The compounds of formulas 26 and 27 (5c and 6c in Scheme 1) were synthesized in the same manner using n- Octylbromide instead of the alkyl halide CH ₃ I used in Example 4-6 i). The structure of the resulting compound was confirmed by ¹ H-NMR. M / z of Formula 26: 862.42, CHN elemental analysis C: 69.58, H: 8.64, N: 3.23; M / z of Chemical Formula 27: 1230.52, CHN elemental analysis C: 72.18, H: 7.35, N: 2.28.

ii) Synthesis of Polymer I and Polymer II

These polymers were generally synthesized by the well-known Ni (0) -mediated Yamamoto Aryl coupling method. A typical method of synthesizing Polymer I is as follows: A 50 mL Schlenk flask was completely dehydrated several times through vacuum and nitrogen. After complete removal of water, Ni (COD) ₂ 305 mg (1.09 mmol) and 2,2'-bipyridyl 172 mg (1.09 mmol) were placed in a glove box and passed through vacuum and nitrogen several times. Under nitrogen stream, 5 ml of anhydrous DMF, 118 mg (0.14 mmol) COD and 5 ml of anhydrous toluene are added. After stirring at 80 ° C. for 30 minutes, 552 mg (0.64 mmol) of the compound of the starting material Formula 26 are added in 5 ml of toluene. The remaining 5 ml of toluene was added while washing all the substances on the base wall and stirred for 4 days at 80 ℃. After 4 days, 1 ml of bromopentafluorobenzene was added as an endcapper and then stirred at 80 ° C. for 1 day. After the reaction, the temperature was lowered to 60 ° C., followed by precipitation in a HCl: acetone: methanol = 1: 1: 1 solution, followed by stirring for 12 hours or more. The precipitate was filtered off, dissolved in a small amount of chloroform and reprecipitated in methanol. The precipitate was recovered through a gravity filter, and then soxhlet was sequentially performed using methanol and chloroform. Finally, the chloroform solution was reconcentrated and precipitated in methanol to obtain 315 mg (70%) of polymer product. The structure of the resulting compound was confirmed by ¹ H-NMR. Molecular weight of Polymer I: Mn = 65000, Mw = 121,000; Molecular weight of Polymer II: Mn = 85,000, Mw = 180,000.

Scheme 3

Example 12 Synthesis of Polymer III

Scheme 4

   i) Synthesis of Compound M-1

19 g of catechol was dissolved in Acetonitrile (200 ml), 1-bromooctane (2.5 eq), K ₂ CO ₃ (2.5 eq), KI (0.1 eq) were added thereto, and the mixture was heated to reflux (24 hours). After the reaction was completed, the organic layer was concentrated under reduced pressure after filtration. The residue obtained by concentrating under reduced pressure was dissolved in Ethyl Ether (200 ml), the organic layer was washed with water (100 ml) and saturated brine to separate the organic layer, and then dehydrated with MgSO ₄ (20 g). 57.17 g (99%) of the title compound was obtained as a solid. The structure of the resulting compound was confirmed by ¹ H-NMR.

ii) Synthesis of Compound M-2

M-1 (57.17 g) is dissolved in 400 ml of CH ₂ Cl ₂ , and NBS (1.1 eq) is added dropwise with DMF (100 ml) at 0 ° C. and allowed to react at room temperature for 2 hours. After completion of the reaction, the reaction solution was washed twice with water (200 ml), and then the organic layer was washed with Na ₂ S ₂ O ₃ · H ₂ O solution, saturated NaHCO ₃ solution, and Brine, followed by Mg ₂ SO ₄ . The resulting mixture was filtered and concentrated under reduced pressure to give 69.01 g (98%) of the title compound. The structure of the resulting compound was confirmed by ¹ H-NMR.

iii) Synthesis of Compound M-3

M-2 (69.03 g) was added to a 2 L flask and dissolved in anhydrous THF (500 ml), and n -BuLi (1.2eq) was slowly added dropwise at -78 ° C, followed by stirring for 10 minutes, followed by 2-Isopropoxy-4,4, 5,5-tetramethyl-1,3,2-dioxaborolane (1.1 eq) was slowly added dropwise at the same temperature. After stirring for about 1 hour and the reaction is complete, the reaction solution is added with EA (300 ml) and water (300 ml) and then the organic layer is separated. The organic layer was washed with saturated NaHCO ₃ (150 ml) solution and brine (150 ml), filtered and treated with Mg ₂ SO ₄ , and the filtrate was concentrated under reduced pressure to obtain 46.26 g (60%) of the title compound. The structure of the resulting compound was confirmed by ¹ H-NMR.

iv) Synthesis of Compound M-4

M-3 (46.26 g) and M-2 (1.1 eq) were dissolved in DME: H2O = 1.5: 1 (300 ml) and then Pd (OAc) ₂ (0.1eq), (Tris-O-tolyl) ₃ phosphine ( 0.1 eq) was added and K ₂ CO ₃ (2.5 eq) was dissolved in DME: H 2 O = 1.5: 1 (150 ml) and added dropwise to react for 1 hour by heating under reflux. Upon completion of the reaction, EA (300 ml) and water (200 ml) were added to the reaction solution, the organic layer was separated, dehydrated with Mg ₂ SO ₄ (30 g), filtered, and the filtrate was concentrated under reduced pressure. The concentrated residue was recrystallized in ethanol to obtain 40.19 g (60%) of the title compound. The structure of the resulting compound was confirmed by ¹ H-NMR.

v) synthesis of compound M-5

M-4 (40.19 g) was dissolved in CH ₂ Cl ₂ (350 ml), cooled to 0 ° C. to 5 ° C., NBS (1.1 eq) was added to the reaction mixture, and left to stand for 2 hours at room temperature. . After the reaction was completed, water (200 ml) was added to the reaction solution, the mixture was stirred, the organic layer was separated, washed with saturated NaHCO ₃ (100 ml) solution and brine (100 ml), and dehydrated with Mg ₂ SO ₄ (30 g). The filtrate was concentrated under reduced pressure. The residue obtained by concentration under reduced pressure was recrystallized from EtOH to give 44 g (98%) of the title compound. The structure of the resulting compound was confirmed by ¹ H-NMR.

vi) synthesis of dibromo monomer compounds

M-5 (2.21 g, 2.96 mmol) was dissolved in anhydrous THF (50 ml) and then cooled to -78 ° C. t- BuLi (3.5 ml, 1.7 M) was slowly added dropwise to the reaction solution, stirred for 1 hour, and a solution of 4b (0.654 g, 1.48 mmol) dissolved in anhydrous THF (30 ml) was added dropwise to the reaction solution for 30 minutes. do. After the reaction was completed, the reaction solution was concentrated under reduced pressure, and the residue was added with EA (50 ml) and saturated brine (50 ml) to separate the organic layer. The organic layer was dehydrated with Mg ₂ SO ₄ (3 g), and the filtrate was concentrated under reduced pressure. The residue obtained by concentration was subjected to silica gel column using n- Hexane: EA = 4: 1 as a developing solvent to separate the target compound to obtain 2.19 g (85%). The structure of the resulting compound was confirmed by ¹ H-NMR. M / z of 7c: 1739.98, CHN elemental analysis C: 73.15, H: 8.68, N: 1.60.

vii) Synthesis of Polymer III

This polymer was synthesized using the same method as in Example 10-11. produce

The structure of the compound was confirmed by ¹ H-NMR. Molecular weight of Polymer III: Mn =

91,000, Mw = 210,000.

Luminescent Properties of Coloring Compound

UV and PL spectra of Formula 16 were measured and shown in FIGS. 2 and 3. As shown in FIG. 2, the UV-vis spectrum showed an absorption band at 389 nm, which appears to be due to the π → π ^* transition of the conjugated double bond. According to the PL spectrum, when the excitation wavelength was 389 nm, the maximum wavelength of the emission color was 409 nm and appeared at the blue wavelength. This corresponds to a quantum energy of 3.04 eV. UV and PL spectra of the compounds of Formulas 14, 20, and 24 were measured to confirm blue emission.

Fabrication of Electroluminescent Devices

Example 13

Forming an ITO layer on a glass substrate as an anode, and a vacuum-deposited MTDATA (4,4 ', 4 "-tris { N - - (methylphenyl) N -phenylamino} triphenylamine) and NPB following Examples 1, 3, 4, and 8 the compound was prepared in accordance with the vacuum vapor deposition. the vacuum deposited Alq ₃ was vacuum deposited thereon a LiF (1 nm) and aluminum metal (200 nm) to prepare a light emitting diode. vacuum deposition is 1 × 0 ^-6 torr vacuum Under the conditions, it was carried out at a rate of 1 s / sec and formed into an area of 9 mm 2 The film thickness and the growth rate of the film during deposition were controlled using a film thickness monitor.

Example 14

After cleaning the transparent electrode substrate coated with indium-tin oxide (ITO), ITO is patterned by using a photoresist resin and an etchant to form an ITO electrode pattern. It was washed clean. The resultant was coated with PEDOT (poly (styrene sulfonate) -doped poly (3,4-ethylenedioxy thiophene: Batron P 4083 from Bayer) at a thickness of about 500Å and then baked at 180 ° C. for about 1 hour. baking to form a hole injection layer On top of the hole injection layer, spin coating was performed on the light emitting layer formation composition obtained by dissolving Polymer I prepared according to Example 10 in chlorobenzene. After baking for 2 hours at 90 ° C., the solvent was completely removed in a vacuum oven to form a light emitting layer having a thickness of 800 Pa. Then, the vacuum degree was increased to 4 × 10 ⁻⁶ using a vacuum evaporator on the polymer emitting layer. Ca and Al were deposited sequentially while maintaining below torr to form a cathode having a thickness of 2500 to 3000Å and encapsulation to complete the organic EL device. Growth rate was adjusted using a crystal sensor (crystal sensor). The EL device produced in this manner was a light emitting area as a single-layered device is 4 mm ^2.

Investigation of characteristics of electroluminescent device

 An electric field was applied to the light emitting diodes of Examples 13 and 14 to measure I-V characteristics and EL characteristics. EL characteristics of the light emitting diode to which the compound of Formula 16 is applied are shown in FIG. 4. I-V characteristics of the light emitting diodes were measured using a forward bias voltage as a direct current voltage using a Keithley SMU238. The luminance from the device was measured using a PR-650 luminance meter, and the efficiency thereof was measured. Table 1 shows the measurement results of turn-on voltage, maximum luminance, luminous efficiency and emission color of light emitting diodes using the compounds of Formulas 14, 16, 20, 24 and polymers I and III.

TABLE 1

compound Turn-on (V) Highest brightness (cd / m ² ) Luminous efficiency (cd / A) Color Remarks Formula 14 3.9 5510 3.1 Deep blue Example 1 Formula 20 4.2 6310 3.3 Blue Example 4 Formula 24 4.0 3530 2.5 Blue Example 8 Formula 16 4.5 2200 2.7 Deep blue Example 3 Polymer I 3.1 2570 1.3 Blue Example 10 Polymer III 3.3 3320 0.8 Blue Example 12

As shown in Table 1, the device including the compound according to the present invention showed typical diode I-V characteristics, the turn-on voltage was 3.3 to 4.5V. The polymer is slightly lower than the low molecule in terms of luminous efficiency, but this can be improved through copolymerization with monomers having excellent hole transport or electron transport characteristics. In general, the emission colors represented various colors (410-470 nm) ranging from deep blue to blue. It also showed excellent characteristics in brightness and luminous efficiency.

The organic compound for an electroluminescent device of the present invention may be applied to any one or both of a hole transport layer, a hole injection layer, a light emitting layer and an electron injection layer, an electron transport layer. The organic compound of the present invention can be preferably used in the hole transport layer and the hole injection layer because of excellent hole transportability and hole injection properties. When the compound is applied to an electroluminescent device, blue light emission may be driven at a low voltage. In addition, as an organic compound having a conjugated double bond, an energy transfer system (doping structure) device structure with an appropriate host or dopant compound can be formed, so that various colors can be realized with low energy, and brightness and luminous efficiency can be excellently increased. have.

All simple modifications or changes of the present invention can be easily carried out by those skilled in the art, and all such modifications or changes can be seen to be included in the scope of the present invention.

Claims (8)

A compound for an electroluminescent device comprising at least one compound selected from the group consisting of monomers of any one of Formulas 1 to 3, oligomeric compounds thereof, and polymers thereof: [Formula 1]

[Formula 2]

[Formula 3]

Wherein X ₁ to X ₆ are each independently N or CR ′, wherein R ′ is hydrogen, unsubstituted straight or branched chain alkyl group, cycloalkyl group, alkenyl group, alkynyl group, alkoxy group, aryl group, and hetero Selected from the group consisting of aryl groups), at least one of X ₁ and X ₂ , at least one of X ₃ and X ₄ , at least one of X ₅ and X ₆ is N, R ₁ to Each R ₁₈ is independently hydrogen, deuterium, halogen, -CN, -NO ₂ , a substituted or unsubstituted linear or branched alkyl group, a substituted or unsubstituted linear or branched alkyl group, a substituted or unsubstituted cycloalkyl group , Substituted or unsubstituted alkenyl group, substituted or unsubstituted alkoxy group, substituted or unsubstituted aryl group, substituted or unsubstituted heteroaryl group, substituted or unsubstituted phenothiazine, substituted or unsubstituted Phenoxazine, substituted or unsubstituted phenoxathiin, substituted or unsubstituted acridine, substituted or unsubstituted phenazasiline, substituted or unsubstituted 9- Aza-10-germa-anthracene (9-aza-10-germa-anthracene), SiR ₁₉ R ₂₀ R ₂₁ , OR ₂₂ , NR ₂₃ R ₂₄ and SR ₂₅ , R ₁₉ to Each R ₂₅ is independently selected from hydrogen, a substituted or unsubstituted linear or branched alkyl group, a cycloalkyl group, an alkenyl group, an alkynyl group, an alkoxy group, an aryl group, and a heteroaryl group. The compound for an electroluminescent device according to claim 1, wherein the oligomer or polymer is represented by any one of 4 to 6. [Formula 4]

[Formula 5]

[Formula 6]

In Chemical Formulas 4 to 6, X ₁ to X ₆ and R ₃ to R ₆ , R ₉ to R ₁₂ and R ₁₅ to R ₁₈ is the same as in Chemical Formulas 1 to 3 and n, m and l are in the range of 1 to 10000, respectively. The compound according to claim 1, wherein the oligomer or polymer further comprises a compound represented by the following Chemical Formulas 7 to 8. [Formula 7] X ₇ -Ar-X ₈ [Formula 8]

Wherein Ar is an aromatic group or a heteroaromatic group containing at least one hetero atom in an aromatic ring, X ₇ and X ₈ are a reactive functional group, hydrogen, an unsubstituted linear or branched alkyl group, Selected from the group consisting of a cycloalkyl group, an alkenyl group, an alkynyl group, an alkoxy group, an aryl group, and a heteroaryl group. The compound for an electroluminescent device according to claim 3, wherein the oligomer or polymer comprises a molar ratio of at least one of the monomers of Formulas 1 to 3 and the monomers of Formulas 7 or 8 as 1: 0.01 to 100. The compound for an electroluminescent device according to claim 3, wherein Ar of the compound of Formulas 7 to 8 is any one selected from the group consisting of:

Wherein R is a hydrogen atom, a substituted or unsubstituted linear, branched or cyclic alkyl group or an alkoxy group, or a substituted or unsubstituted aromatic group, and X ₉ is N, O, S or Si. The organic electroluminescent device of claim 1, wherein the compound according to any one of claims 1 to 5 is contained in at least one of a hole transporting layer, a hole injection layer, a light emitting layer and an electron injection layer, and an electron transporting layer. 7. The light emitting layer of claim 6, wherein the light emitting layer is an organic compound having a compound according to any one of claims 1 to 5 and a conjugated double bond, and has an energy gap smaller than that of the dope material. An organic electroluminescent device comprising a dopant having good chromophore properties. The organic electroluminescent device according to claim 6, wherein the light emitting layer comprises a compound according to any one of claims 1 to 5 as a dopant.

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