TW201605841A - A combination of a host compound and a dopant compound - Google Patents

Abstract

The present invention relates to a specific combination of dopant compounds and host compounds. By using a combination of the dopant and host compounds according to the present invention, an organic electroluminescent device has improved current efficiency compared with conventional light-emitting material, and thus has improved power efficiency at a low driving voltage.

Description

Combination of host compound and dopant compound

The present invention is directed to a combination of a particular dopant compound and a host compound.

An electric field illuminating (EL) device has a self-illuminating device that provides advantages of a wider viewing angle, a larger contrast value, and a faster response time. The organic EL device based firstly developed by Eastman Kodak Company (Eastman Kodak), which is based small molecule aromatic diamine and an aluminum complex compound as the material to form the light-emitting layer [see Appl. Phys] .

The organic EL device converts electrical energy into light by injecting a charge into the organic light-emitting material, and generally includes an anode, a cathode, and an organic layer formed between the two electrodes. The organic layer in the organic EL device may be a hole injection layer (HIL), a hole transport layer (HTL), an electron blocking layer (EBL), an emission layer (EML) (containing a host and a dopant material), An electron transport layer (ETL), a hole blocking layer (HBL), an electron injection layer (EIL), etc.; materials used for the organic layer may be classified into a hole injection material, a hole transmission material, an electron blocking material according to functions, Luminescent materials, electron transport materials, Hole blocking material, electron injecting material, and the like. In the organic EL device, a hole from an anode and an electron from a cathode are injected into a light-emitting layer by charge injection, and excitons having high energy are generated by recombination of the hole and electrons. The organic light-emitting compound enters an excited state by the energy and emits light, which is converted from energy when the organic light-emitting compound returns from a excited state to a ground state.

The most important factor affecting the characteristics (e.g., luminous efficiency, etc.) in an organic EL device is the luminescent material. The luminescent material is required to have the following characteristics: high quantum efficiency, high degree of movement of electrons and holes, formation of a uniform layer, and stability. The luminescent material is classified into a blue luminescent material, a green luminescent material, and a red luminescent material according to the color of its luminescence, and further contains a yellow or orange luminescent material. Furthermore, the luminescent material is classified as a host material and a dopant material according to its function. In general, it is known that the structure having the best EL characteristics in the device is such that the dopant in the light-emitting layer is doped to the host. In recent years, it has become an urgent task to develop an organic EL device having high performance and long operating life. In particular, in view of the demand for EL characteristics in medium and large OLED panels, the development of excellent luminescent materials beyond conventional luminescent materials is urgent. For this reason, preferably, as a solvent and an energy transmitter in a solid state, in order to deposit a host material under vacuum, it should have a high purity and a suitable molecular weight. Furthermore, the host material is required to have a high glass transition temperature and pyrolysis temperature to ensure its thermal stability, high electrochemical stability to provide long life, easy formability of the amorphous film, good adhesion to adjacent layers, and There will be no relative movement between the layers.

The luminescent material is classified into a fluorescent material according to its excited state (single-state excited state) and phosphorescent material (triplet excited state). This fluorescent material was originally used in an organic EL device. However, phosphorescent materials convert electricity to light four times more efficiently than fluorescent materials, and can reduce energy consumption and extend life. Therefore, the development of phosphorescent materials is in progress.

Up to now, ruthenium (III) complexes are well-known phosphorescent materials containing bis(2-(2'-benzothienyl)-pyridine-N, C3') as red, green, and blue materials, respectively.铱 (acetamidine acetone) ((acac) Ir(btp) ₂ ), ginseng (2-phenylpyridine) ruthenium (Ir(ppy) ₃ ), and bis(4,6-difluorophenylpyridine-N, C2 ) Pyridinium (Firpic).

A hybrid system of dopant/host materials can be used as the luminescent material to improve color purity, luminescence efficiency, and stability. In general, the device having excellent EL characteristics includes a light-emitting layer in which a dopant is doped to the body. If the dopant/host material system is used, the choice of host material is important based on the host material greatly affecting the efficiency and efficacy of the illuminating device. In the conventional art, 4,4'-N,N'-dicarbazole-biphenyl (CBP) is the most well-known phosphorescent host material. Pioneer (Pioneer, Japan) and other companies, recently used bath copper spirit (BCP), aluminum (III) bis (2-methyl-8-hydroxyquinoline) (4-phenylphenol) (BAlq) equal to the hole barrier As a main material, a high-performance organic EL device has been developed.

Although these phosphorescent host materials provide good luminescent properties, they have the following disadvantages: (1) Due to their low glass transition temperature and poor thermal stability, they may be degraded in a vacuum high temperature deposition process. (2) The power efficiency of the organic EL device is obtained by [(π/voltage) × current efficiency], which is inversely proportional to the voltage. Including phosphorescent host material The organic EL device provides higher current efficiency (cd/A) than the organic EL device including the fluorescent host material, but requires a higher driving voltage; therefore, the organic EL device using the conventional phosphorescent material is power efficient (Lumens/Watt (lm/W)) has no advantage. (3) Furthermore, the operational life and luminous efficiency of the organic EL device are not satisfactory.

Therefore, an organic EL device including a light-emitting material (containing a conventional dopant and a host compound) does not have good power efficiency, a satisfactory operational life, and high luminous efficiency.

Korean Patent Application Laid-Open No. 2013-0054205 and No. 2011-0130475, and U.S. Patent Application No. 2013/0026452 A1, the disclosure of which is incorporated herein in Pyridine and a heterocoordinate ruthenium complex containing a coordination of a dibenzo ligand, but there is no mention of a combination of specific host compounds suitable for the dopant compound.

The inventors of the present invention have found that a luminescent material containing a specific combination of a dopant compound and a host compound is more efficient in improving the power efficiency and luminous efficiency of the organic EL device than conventional luminescent materials.

It is an object of the present invention to provide a specific combination of a dopant compound and a host compound which can improve the power efficiency of the organic EL device by reducing the driving voltage of the organic EL device.

The foregoing object can be achieved by a combination of at least one dopant compound represented by the following formula (1) and at least one host compound represented by the following formula (2): IrL ₁ L ₂ L ₃ (1)

Wherein L ₁ to L _{3 are} each independently selected from the following structures, and the constraint is that at least one of L ₁ to L ₃ represents A-1, A-2 or A-3: X represents O or S; R ₁ to R ₁₁ each independently represent hydrogen, deuterium, halogen, cyano, substituted or unsubstituted (C1-C30) alkyl, substituted or unsubstituted (C3-C30) a cycloalkyl group, a substituted or unsubstituted (C6-C30) aryl group, or a substituted or unsubstituted 5 to 30 membered heteroaryl group; and a to h each independently represent an integer from 0 to 4; When h is an integer of 2 or more, each of R ₁ to R ₈ is the same or different.

Wherein Y ₁ represents O, S, NR ₃₁ or CR ₃₂ R ₃₃ ; L ₄ represents a single bond, a substituted or unsubstituted (C6-C30) aryl group, or a substituted or unsubstituted 5 to 30 member impurity aryl group; R ₂₁ to R ₂₃ each independently represent hydrogen, deuterium, halogen, cyano, substituted or non-substituted (C1-C30) alkyl, substituted or non-substituted (C6-C30) aryl group, Substituted or unsubstituted 5 to 30 membered heteroaryl, substituted or unsubstituted thiol, or substituted or unsubstituted amine; or linked to each other to form a single or multiple ring 3 to 30 An alicyclic or aromatic ring wherein one or more carbon atoms of the ring may be replaced by at least one hetero atom selected from the group consisting of nitrogen, oxygen and sulfur; Ar ₁ represents a substituted or unsubstituted (C6-C30) aryl group. a 5- or 30-membered heteroaryl group containing a nitrogen atom; R ₃₁ to R ₃₃ each independently represent hydrogen, substituted or unsubstituted (C1-C30) alkyl, substituted Or unsubstituted (C6-C30) aryl, or substituted or unsubstituted 5 to 30 membered heteroaryl; or alicyclic or aromatic ring of 3 to 30 members bonded to each other to form a single or multiple ring , wherein one or more carbons of the ring At least one promoter may be selected from nitrogen, oxygen and sulfur heteroatoms of substitution; m and o each independently represents an integer of 0 to 4; and when m or o is an integer of 2 or more, each R ₂₁ or R ₂₃ each system Same or different; n represents an integer from 0 to 2; when n is 2, each R ₂₂ is the same or different; and the heteroaryl contains at least one selected from the group consisting of B, N, O, S, P(=O), Si And the hetero atom of P.

The combination of the dopant compound and the host compound of the present invention has excellent luminescent properties and is reduced by the organic EL device The driving voltage is set to increase the power efficiency of the organic EL device.

The contents of the present invention will be described in detail below. However, the following description is intended to be illustrative of the invention and is not intended to limit the scope of the invention.

The present invention relates to a combination of at least one dopant compound represented by the formula (1) and at least one host compound represented by the formula (2).

In the compound of the formula (1), preferably, R ₁ to R ₁₁ each independently represent hydrogen, substituted or unsubstituted (C1-C10)alkyl, substituted or unsubstituted (C3-C10). A cycloalkyl group, a substituted or unsubstituted (C6-C20) aryl group, or a substituted or unsubstituted 5 to 20 membered heteroaryl group. In the compound of the formula (2), preferably, L ₄ represents a single bond, a substituted or unsubstituted (C6-C20) aryl group, or a substituted or unsubstituted 5 to 20 membered heteroaryl group, R ₂₁ to R ₂₃ each independently represent hydrogen, substituted or non-substituted (C1-C10) alkyl, substituted or non-substituted (C6-C20) aryl group, a substituted or unsubstituted 5 to 20 of a heteroaryl group, or a substituted or unsubstituted fluorenyl group, and Ar ₁ represents a substituted or unsubstituted (C6-C20) aryl group, or a substituted or unsubstituted 5 to 20 member containing nitrogen A heteroaryl group of an atom.

The dopant compound of the formula (1) is represented by the following formula (3), (4) or (5):

Wherein R ₁ to R ₆ , a to f, X, L ₂ and L ₃ are as defined in the formula (1).

The compound of the formula (3) can be specifically exemplified by the following compounds:

The compound of the formula (4) can be specifically exemplified by the following compounds:

The compound of the formula (5) can be specifically enumerated by the following compounds:

The host compound of the formula (2) is represented by one of the following formulas (6) to (11):

Wherein R ₂₁ to _{R 23, Y 1, L 4} , in Ar _1, m, n and o lines as in formula (2) is defined.

The compounds of the formulae (6) to (11) can be specifically enumerated by the following compounds:

Here, "(C1-C30)(alkyl)alkyl" means a straight or branched (extended) alkyl group having 1 to 30 carbon atoms, and the number of carbon atoms is preferably from 1 to 20, more preferably 1 to 10, and includes methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, t-butyl and the like. "(C2-C30)alkenyl" means a straight or branched alkenyl group having 2 to 30 carbon atoms, preferably having 2 to 20 carbon atoms, more preferably 2 to 10 carbon atoms, and containing a vinyl group. 1-propenyl, 2-propenyl, 1-butenyl, 2-butenyl, 3-butenyl, 2-methylbut-2-enyl and the like. "(C2-C30)alkynyl" means a straight or branched alkynyl group having 2 to 30 carbon atoms, preferably having 2 to 20 carbon atoms, more preferably 2 to 10 carbon atoms, and containing an ethynyl group. 1-propynyl, 2-propynyl, 1-butynyl, 2-butynyl, 3-butynyl, 1-methylpent-2-ynyl, and the like. "(C3-C30)cycloalkyl" is a mono- or polycyclic hydrocarbon having 3 to 30 carbon atoms, preferably having a carbon number of 3 to 20, more preferably 3 to 7, and comprising a cyclopropyl group and a ring. Butyl, cyclopentyl, cyclohexyl and the like. "3 to 7 membered heterocycloalkyl" means a group having at least one selected from the group consisting of B, N, O, S, P(=O), Si, and P (preferably, O, S, and N) An atom, and a cycloalkyl group of 3 to 7 ring main chain atoms (preferably 5 to 7 ring main chain atoms), and contains tetrahydrofuran, pyrrolidine, tetrahydrothiophene, tetrahydropyran, and the like. "(C6-C30) (extended) aryl" is a monocyclic or fused ring derived from an aromatic hydrocarbon having 6 to 30 carbon atoms, preferably having 6 to 20 carbon atoms, more preferably 6 to 15 carbon atoms. And comprising phenyl, biphenyl, terphenyl, naphthyl, anthracenyl, phenanthryl, anthryl, fluorenyl, tert-triphenyl, fluorenyl, tetracenyl, fluorenyl, fluorene Base, naphthacenyl, alkadiene thiol and the like. The "3 to 30 member hetero (aryl) aryl group" has at least one, preferably 1 to 4 hetero atoms selected from the group consisting of B, N, O, S, P (=O), Si and P. And an aryl group of 3 to 30 ring main chain atoms; may be a single ring or a fused ring fused to at least one benzene ring; preferably having 3 to 20 ring main chain atoms, more preferably 3 to 15 rings a backbone atom; may be partially saturated; may be formed by linking at least one heteroaryl or aryl group to a heteroaryl group through one or more single bonds; and comprise a monocyclic heteroaryl group comprising a furyl group, a thienyl group , pyrrolyl, imidazolyl, pyrazolyl, thiazolyl, thiadiazolyl, isothiazolyl, iso Azolyl, Azolyl, Diazolyl, three Base, four Base, triazolyl, tetrazolyl, furazolyl, pyridyl, pyridyl Base, pyrimidinyl, oxime And the fused ring heteroaryl group, including a benzofuranyl group, a benzothienyl group, an isobenzofuranyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a benzimidazolyl group, a benzothiazolyl group, Benzoisothiazolyl, benzoid Azolyl, benzo Azolyl, isodecyl, fluorenyl, oxazolyl, benzothiadiazolyl, quinolyl, isoquinolyl, porphyrinyl, quinazolinyl, quin Orolinyl, carbazolyl, brown Peptidyl, benzodiyl 呃基等. "Halogen" includes F, Cl, Br, and I.

As used herein, "substituted" in "substituted or unsubstituted" means that a hydrogen atom in a particular functional group is replaced by another atom or group (ie, a substituent). In the formula of the present invention, the substituted (C1-C30) alkyl group, the substituted (C3-C30) cycloalkyl group, the substituted (C6-C30) aryl group, and the substituted 5 Substituents to up to 30 membered heteroaryl groups, each independently being selected from at least one of the group consisting of: hydrazine; halogen; cyano; carboxy; nitro; hydroxy; unsubstituted or substituted by one or more halogens (C1-C30)alkyl; (C2-C30)alkenyl; (C2-C30)alkynyl; (C1-C30)alkoxy; (C1-C30)alkylthio; (C3-C30)cycloalkane (C3-C30)cycloalkenyl; 3 to 7 membered heterocycloalkyl; (C6-C30) aryloxy; (C6-C30) arylthio; unsubstituted or via (C6-C30) aryl Substituted 3 to 30 membered heteroaryl; (C6-C30) aryl unsubstituted or substituted with 3 to 30 membered heteroaryl; tri(C1-C30)alkylindenyl; tris(C6-C30)aryl Alkyl fluorenyl; bis(C1-C30)alkyl (C6-C30) aryl fluorenyl; (C1-C30)alkyl di(C6-C30)aryl fluorenyl; amine; mono or di (C1-C30) Alkenylamino; mono or di(C6-C30)arylamino; (C1-C30)alkyl(C6-C30)arylamino; (C1-C30)alkylcarbonyl; (C1-C30) Alkoxycarbonyl; (C6-C30) arylcarbonyl; di(C6-C30) aryl boron; di(C1-C3 0) alkyl boron group; (C1-C30) alkyl (C6-C30) aryl boron group; (C6-C30) aryl (C1-C30) alkyl group; and (C1-C30) alkyl group (C6- C30) aryl.

The organic EL device of the present invention comprising the dopant compound and the host compound may include a first electrode, a second electrode, and at least one organic layer interposed between the first and second electrodes, wherein the organic layer The light-emitting layer includes at least one dopant compound represented by the formula (1) and at least one host compound represented by the formula (2).

The luminescent light-emitting layer can be a single layer or a plurality of layers having two or more layers. In the light-emitting layer, the doping concentration of the dopant compound to the host compound is preferably less than 20% by weight (wt%).

According to another specific embodiment, the present invention provides a combination of at least one dopant compound represented by the formula (1) and at least one host/dopant of the host compound represented by the formula (2). Furthermore, the present invention provides an organic EL device comprising the host/dopant combination.

According to another specific embodiment, the present invention provides the organic layer containing at least one dopant compound represented by the formula (1) and at least one host compound represented by the formula (2). The organic layer includes a plurality of layers, and the dopant compound and the host compound may be contained in one layer or different layers. Furthermore, the present invention provides an organic EL device including the organic layer.

The organic EL device of the present invention may further comprise at least one compound selected from the group consisting of an arylamine-based compound and a styrylarylamine-based compound in the organic layer.

In the organic EL device of the present invention, the organic layer may further include at least one metal selected from the group consisting of: a first group metal of the periodic table, a second group metal, a transition metal of a fourth period, a five-period transition metal, a lanthanide, and an organometallic of a d-transition element; or at least one complex comprising the metal.

Preferably, in the organic EL device of the present invention, at least one layer selected from the group consisting of a chalcogenide layer, a metal halide layer, and a metal oxide layer (hereinafter referred to as a "surface layer") may be placed in one or two On the inner surface of the electrode. Specifically, it is preferred that a chalcogenide (including oxide) layer of lanthanum or aluminum is placed on the anode surface of the luminescent medium layer, and a metal halide layer or a metal oxide layer is placed on the cathode surface of the EL medium layer. The surface layer provides operational stability of the organic EL device. Preferably, the chalcogenide comprises SiO _X (1 X 2), AlO _X (1 X 1.5), SiON, SiAlON, etc.; the metal halide comprises LiF, MgF ₂ , CaF ₂ , a rare earth metal fluoride, etc.; and the metal oxide comprises Cs ₂ O, Li ₂ O, MgO, SrO, BaO, CaO, and the like.

Preferably, in the organic EL device of the present invention, a mixed region of the electron transporting compound and the reducing dopant, or a mixed region of the hole transporting compound and the oxidizing dopant, may be placed on at least one surface of the electrode pair. . In this case, the electron transporting compound is reduced to an anion, and thus it becomes easier to inject and transport electrons from the mixed region to the luminescent medium. Furthermore, the hole transporting compound is oxidized to a cation, so that it becomes easier to inject and transport holes from the mixed region to the luminescent medium. Preferably, the oxidizing dopant comprises a plurality of Lewis acids and a acceptor compound; and the reducing dopant comprises an alkali metal, an alkali metal compound, an alkaline earth metal, a rare earth metal, and a mixture thereof. A reducing dopant layer may be employed as the charge generating layer to provide an organic EL device having two or more light emitting layers and emitting white light.

In order to form the respective layers constituting the organic EL device of the present invention, a dry film formation method such as vacuum deposition, sputtering, plasma, ion plating, or the like, or a wet film formation method such as spin coating, dip coating, or flow coating may be used. Law and so on.

When the wet film formation method is used, the material forming the layers is dissolved or dispersed in any suitable solvent (for example, ethanol, chloroform, tetrahydrofuran, two Alkane, etc.) forms a film. The solvent is not particularly limited as long as the material constituting each layer is soluble or dispersible in the solvent without causing any problem on the formation layer.

Hereinafter, representative dopant compounds and host compounds of the present invention, methods for preparing the compounds, and characteristics of the light-emitting device including the combinations thereof will be explained in detail with reference to the following examples:

Example 1: Preparation of Compound D-2

Preparation of Compound 1-1

2-Phenylpyridine (10.0 g (g), 32.0 mmol (mmol)), ruthenium (III) chloride hydrate (IrCl ₃ ‧ x H ₂ O) (8.1 g, 29.0 mmol), 2-ethoxy Ethanol (220.0 mL) and H ₂ O (74.0 mL) were placed in a flask and stirred at 140 ° C for 24 hours. After the reaction was completed, the mixture was cooled to room temperature, washed with H ₂ O and methanol (MeOH), and then dried to give Compound 1-1 (11.0 g, 71%).

Preparation of Compound 1-2

Compound 1-1 (10.0 g, 9.0 mmol) was dissolved in dichloromethane (MC) (4.0 liter (L)). Silver trifluoromethanesulfonate (AgOTf) (5.0 g, 19.0 mmol) dissolved in MeOH (400.0 mL (mL)) was slowly added, and the mixture was stirred at room temperature for 12 hr. After completion of the reaction, the reaction mixture was filtered, and the filtrate was dried to give Compound 1-2 (12.0 g, 94%).

Preparation of Compound 1-3

2-Bromopyridine (10.0 g, 63.0 mmol), dibenzo[b,d]furan-4-ylboronic acid (16.0 g, 76.0 mmol), tetrakis(triphenylphosphine)palladium(0)[Pd(PPh) ₃ ) ₄ ] (2.2 g, 2.0 mmol), Na ₂ CO ₃ (20.0 g, 19.0 mmol), toluene (300.0 mL), ethanol (EtOH) (150.0 mL), and H ₂ O (10.0 mL) were placed in the flask Medium and stirred at 100 ° C for 2 hours. After the reaction was completed, the mixture was cooled to room temperature and extracted with ethyl acetate (EA). The remaining moisture was removed with MgSO ₄ , and the mixture was distilled under reduced pressure and purified by column chromatography with MC / hexane (Hx) = 1/3 to give Compound 1-3 (10.0 g, 63%).

Preparation of Compound D-2

MeOH (200.0 mL) and EtOH (100.0 mL) were added to a mixture of 1-3 (7.0 g, 28.0 mmol) and Compound 1-2 (10.0 g, 14.0 mmol), and the mixture was stirred at reflux for 12 hours. . After the reaction was completed, the mixture was cooled to room temperature and filtered. Chloroform (CHCl ₃₎ subjected to column chromatography to give compound D-2 (2.0g, 17% ).

MP 400 ° C or higher, UV 292 nm, PL 525 nm, LC 99.06%.

Example 2: Preparation of Compound D-3

Preparation of Compound 2-1

2-Bromo-5-methylpyridine (15.0 g, 87.0 mmol), phenylboronic acid (14.0 g, 114.0 mmol), Pd(PPh ₃ ) ₄ (3.0 g, 2.6 mmol), K ₂ CO ₃ (36.0 g) , 260.0 mmol), toluene (300.0 mL), EtOH (150.0 mL), and H ₂ O (130.0 mL) were placed in a flask and stirred at 100 ° C for 3 hours. After completion of the reaction, the mixture was extracted with EA, the remaining moisture was removed with MgSO ₄ , and the mixture was distilled under reduced pressure. Column chromatography with MC/Hx = 1/2 gave Compound 2-1 (10.0 g, 68%) as a white solid.

Preparation of Compound 2-2

Compound 2-1 (10.0 g, 30.0 mmol), IrCl ₃ ‧xH ₂ O (8.0 g, 27.0 mmol), 2-ethoxyethanol (200.0 mL) and H ₂ O (70.0 mL) were placed in a flask. It was stirred at 140 ° C for 24 hours. After the reaction was completed, the mixture was cooled to room temperature and washed with H ₂ O and MeOH, and then dried to afford compound 2-2 (11.0 g, 75%).

Preparation of Compound 2-3

In a flask, Compound 2-2 (11.0 g, 10.0 mmol) was dissolved in MC (4.0 L). AgOTf (5.0 g, 20.0 mmol) dissolved in MeOH (400.0 mL) was slowly added and the mixture was stirred at room temperature for 12 hr. After the reaction was completed, the reaction mixture was filtered, and the filtrate was dried to give Compound 2-3 (13.0 g, 89%).

Preparation of Compound D-3

In a flask, MeOH (200.0 mL) and EtOH (100.0 mL) were added to Compound 1-3 (7.0 g, 28.0 mmol) and Compound 2-3 (10.0 g, 14.0 mmol), and the mixture was stirred at reflux 12 hour. After the reaction was completed, the mixture was cooled to room temperature and filtered. Subjected to column chromatography in CHCl _3, to obtain compound D-3 (3.5g, 33% ).

MP 400 ° C or higher, UV 292 nm, PL 527 nm, LC 99.19%

Example 3: Preparation of Compound D-95

Preparation of Compound 3-1

2-Bromo-4-methylpyridine (10.0g, 63.0mmol), dibenzo [b, d] furan-4-ylboronic acid (15.0g, 76.0mmol), Pd ( PPh 3) 4 (2.2g, 2.0 mmol), Na ₂ CO ₃ (20.0 g, 19.0 mmol), toluene (300.0 mL), EtOH (150.0 mL), and H ₂ O (10.0 mL) were placed in a flask and stirred at 100 ° C for 2 hours. After the reaction was completed, the mixture was cooled to room temperature and extracted with EA. The remaining moisture was removed with MgSO ₄ and the mixture was distilled under reduced pressure. Column chromatography with MC/Hx = 1/3 gave Compound 3-1 (11.0 g, 67%) as a white solid.

Preparation of Compound D-95

In a flask, MeOH (200.0 mL) and EtOH (100.0 mL) were added to Compound 3-1 (7.0 g, 28.0 mmol) and Compound 2-3 (10.0 g, 14.0 mmol), and the mixture was stirred at reflux 12 hour. After the reaction was completed, the mixture was cooled to room temperature and filtered. To CHCl ₃ subjected to column chromatography to give compound D-95 (1.5g, 15% ).

MP 400 ° C or higher, UV 292 nm, PL 519 nm, LC 99.12%

Example 4: Preparation of Compound D-96

Preparation of Compound 4-1

2-Bromo-5-methylpyridine (10.0 g, 63.0 mmol), dibenzo[b,d]furan-4-ylboronic acid (15.0 g, 76.0 mmol), Pd(PPh ₃ ) ₄ (2.2 g, _{2.0mmol), Na 2 CO 3 (} 20.0g, 19.0mmol), toluene (300.0mL), EtOH (150.0mL) , and H ₂ O (10.0mL) placed in a flask, and stirred at 100 ℃ 2 hours. After the reaction was completed, the mixture was cooled to room temperature and extracted with EA. MgSO ₄ to remove the residual moisture, and the mixture was distilled under reduced pressure. Column chromatography with MC/Hx = 1/3 gave Compound 4-1 (13.0 g, 80%) as a white solid.

Preparation of Compound D-96

In a flask, MeOH (200.0 mL) and EtOH (100.0 mL) were added to Compound 4-1 (7.0 g, 28.0 mmol) and Compound 2-3 (10.0 g, 14.0 mmol) and stirred for 12 hours. After the reaction was completed, the mixture was cooled to room temperature and filtered. Subjected to column chromatography in CHCl _3, to obtain compound D-96 (3.0g, 30% ).

MP 390 ° C, UV 290 nm, PL 521 nm, LC 96.31%

Example 5: Preparation of Compound H-33

Preparation of Compound 5-1

1-Bromo-2-nitrobenzene (39.0 g, 0.19 mol), dibenzo[b,d]furan-4-ylboronic acid (45.0 g, 0.21 mol), Pd(PPh ₃ ) ₄ (11.1 g, A solution of 0.0096 mol), 2M aqueous K ₂ CO ₃ (290.0 mL), EtOH (290.0 mL), and toluene (580.0 mL) were mixed in a flask and heated to 120 ° C and stirred for 4 hours. After the reaction was completed, the mixture was washed with distilled water and extracted with EA. It was dried over anhydrous MgSO ₄ the organic layer, and a rotary evaporator to remove the solvent. The organic layer was purified by column chromatography to afford compound 5-1 (47.0 g, 85%).

Preparation of compound 5-2

Compound 5-1 (47.0 g, 0.16 mol), triethyl phosphite (600.0 mL), and 1,2-dichlorobenzene (300.0 mL) were mixed in a flask, heated to 150 ° C and stirred for 12 hours. After the completion of the reaction, the unreacted triethyl phosphite and 1,2-dichlorobenzene were removed by a distillation apparatus. The mixture was washed with distilled water and extracted with EA. In anhydrous organic layer over MgSO _4, and rotary evaporator to remove the solvent. The organic layer was purified by column chromatography to afford compound 5-2 (39.0 g, 81%).

Preparation of Compound H-33

In a flask, NaH (1.9 mg, 42.1 mmol) was dissolved in dimethylformamide (DMF), and the mixture was stirred. In a flask, Compound 5-2 (7.0 g, 27.2 mmol) was dissolved in DMF, and a stirred NaH solution was added, and the mixture was stirred for 1 hour. In a flask, 2-chloro-4,6-diphenyldecylamine (8.7 g, 32.6 mmol) was dissolved in DMF and stirred. The mixture was stirred for 1 hour and then stirred at room temperature for 24 hours. After completion of the reaction, the obtained solid was filtered, washed with EtOAc, and purified by column chromatography to afford compound H-33 (3.5 g, 25%).

Example 6: Preparation of Compound H-45

Preparation of Compound 6-1

Using dibenzo[b,d]thiophen-4-ylboronic acid (10.0 g, 43.84 mmol) and the same procedure for the preparation of compound 3-1, Compound 6-1 (10.0 g, 32.74 mmol, 74.68%) was obtained.

Preparation of compound 6-2

Using the same procedure as Compound 6-1 (10.0 g, 32.74 mmol) and Compound 5-2, Compound 6-2 (7.0 g, 25.60 mmol, 78.19%).

Preparation of Compound H-45

Compound 6-2 (7.0 g, 25.6 mmol) and 2-chloro-4,6-diphenyl-1,3,5-three were used. (8.7 g, 32.6 mmol), and the same procedure for the compound H-33, Compound H-45 (5.6 g, 40.0%).

Example 7: Preparation of Compound H-60

Compound 6-2 (5.3 g, 25.6 mmol) and Compound 7-1 (8.2 g, 32.6 mmol),

Example 8: Preparation of Compound H-110

Preparation of Compound 8-1

2-Bromo-9,9-dimethyl-9H-indole (80.0 g, 291.0 mmol), 2-chloroaniline (45.0 mL, 437.0 mmol), palladium(II) acetate [Pd(OAc) ₂ ] (2.6 g, 12.0 mmol), tri-t-butylphosphine [P(t-Bu) ₃ ] (12.0 mL, 24.0 mmol), sodium butoxide (NaOt-Bu) (70.0 g, 728.0 mmol), and toluene (800.0 mL) was mixed in a flask, heated to 120 ° C and stirred for 9 hours. After the reaction was completed, the mixture was cooled to room temperature and then extracted with EA (1.5L). The obtained organic layer was washed with distilled water (400.0 mL). Next, the solvent was removed under reduced pressure, and the obtained solid was washed with hexane, filtered and dried. After the solid was separated by silica gel column chromatography and recrystallized, Compound 8-1 (70.0 g, 75%) was obtained.

Preparation of Compound 8-2

Compound 8-1 (70.0 g, 218.0 mmol), Pd(OAc) ₂ (2.4 g, 11.0 mmol), tricyclohexylphosphine tetrafluoroboric acid (PCy ₃ HBF ₄ ) (8.0 g, 22.0 mmol), Na ₂ CO ₃ (70.0 g, 654.0 mmol) and dimethylacetamide (DMA) (1.2 L) were mixed in a flask and stirred at 190 ° C for 3 hours. After completion of the reaction, to EA (1.0L) and the mixture was extracted, and distilled water (200.0 mL) to obtain the organic layer washed, dried and then to anhydrous MgSO _4. The organic solvent was removed under reduced pressure. After the solid was separated by silica gel column chromatography and recrystallized, Compound 8-2 (22.0 g, 36%) was obtained.

Preparation of Compound 8-3

Compound 8-2 (15.0 g, 53.0 mmol), 1,4-dibromobenzene (32.0 mL, 265.0 mmol), Pd(OAc) ₂ (1.2 g, 5.0 mmol), P(t-Bu) ₃ (30.0) mL, 64.0 mmol), NaOt-Bu (25.0 g, 265.0 mmol), and toluene (300.0 mL) were mixed in a flask and stirred at 120 ° C for 24 hours. After the reaction was completed, the mixture was cooled to room temperature and extracted with EA (1.5L). The obtained organic layer was washed with distilled water (400.0 mL). The solvent was removed under reduced pressure, and the obtained solid was washed with hexane, filtered and dried. After separation by column chromatography on silica gel and recrystallization, Compound 8-3 (7.0 g, 30%) was obtained.

Preparation of Compound 8-4

In a flask, Compound 8-3 (7.0 g, 16.0 mmol) was dissolved in tetrahydrofuran (THF) (100.0 mL), and n-butyllithium (n-BuLi) (2.5 M hexane solution was added at -78 ° C, 10.0 mL, 24.0 mmol). After the mixture was stirred at -78 ° C for 1 hour, triisopropoxy boron [B(Oi-Pr) ₃ ] (6.0 mL, 24.0 mmol) was added. The mixture was stirred for 2 hours and the reaction was completed using aqueous ammonium chloride (20.0 mL). And extracted with EA (500.0 mL) and the mixture, and distilled water (200.0 mL) of the obtained washed organic layer, and then dried over anhydrous MgSO _4. The organic solvent was removed under reduced pressure. After the solid obtained was separated by recrystallization, Compound 8-4 (5.0 g, 75%) was obtained.

Preparation of Compound H-110

2-Chloro-4,6-diphenyl-1,3,5-three (6.5 g, 0.03 mol), compound 8-4 (19.2 g, 0.036 mol), Pd(PPh ₃ ) ₄ (1.6 g, 0.001 mol), K ₂ CO ₃ (11.0 g, 0.08 mol), toluene (140.0 mL) EtOH (35.0 mL) and H ₂ O (40.0 mL) were placed in a flask and stirred at 120 ° C for 12 hours. After completion of the reaction, the mixture was extracted with EA, the organic layer obtained was dried over anhydrous and filtered of MgSO _4. The solvent was removed under reduced pressure and the product was purified by column chromatography to afford compound H-110 (5.7 g, 27%).

Example 9: Preparation of Compound H-135

In the flask, o-xylene (110.0 mL) was added to 5-phenyl-5,7-dihydroindolo[2,3-b]carbazole (3.65 g, 10.9 mmol), 2-(3-bromo) Phenyl)-4,6-diphenyl-1,3,5-three (4.9g, 12.6mmol), Pd ( OAc) 2 (0.12g, 0.55mmol), 2- dicyclohexylphosphino-2 ', 6'-dimethoxybiphenyl (S-phos) (0.45g, 1.1mmol After the NaOt-Bu (2.6 g, 27.4 mmol), the mixture was stirred at reflux for one day. After the reaction was completed, the mixture was cooled to room temperature and extracted with distilled water and EA. The obtained organic layer was subjected to distillation under reduced pressure. After column chromatography with MC/Hx, compound H-135 (3.7 g, 52%) was obtained.

Example 10: Preparation of Compound H-176

Preparation of Compound 10-1

In the flask, 5-phenyl-5,7-dihydroindolo[2,3-b]carbazole (10.0 g, 30.1 mmol), 1-bromo-3-iodobenzene (12.8 g, 45.1 mmol) ), CuI (2.9 g, 15.05 mmol), ethylenediamine (EDA) (2.0 mL, 30.1 mmol), and K ₃ PO ₄ (16.0 g, 75.25 mmol) were added toluene (150.0 mL), and the mixture was refluxed Stir for 1 day. The mixture was extracted with MC and distilled under reduced pressure. After column chromatography with MC/Hx, Compound 10-1 (13.2 g, 87%) was obtained.

Preparation of Compound 10-2

Compound 10-1 (13.2 g, 27.1 mmol), bis(triphenylphosphine)palladium(II) dichloride [PdCl ₂ (PPh ₃ ) ₂ ] (0.95 g, 1.35 mmol), bis (pinacol) Bis (pinacolato) diboron (8.25 g, 32.5 mmol), potassium acetate (KOAc) (5.3 g, 54.2 mmol), and 1,4-two Alkane (140.0 mL) was placed in a flask and stirred at 120 ° C for 1 day. After the reaction was completed, the mixture was washed with distilled water and extracted with MC. The obtained organic layer was dried over MgSO ₄ and distilled under reduced pressure to remove solvent. After purification by column chromatography, Compound 10-2 (8.5 g, 59%) was obtained.

Preparation of Compound H-176

Into the flask, toluene (48.0 mL), EtOH (6.0 mL), and distilled water (12.0 mL) were added to the compound 10-2 (5.0 g, 9.36 mmol), three (3.5g, 10.3mmol), Pd ( PPh 3) 4 (0.54g, 0.5mmol), and the K _{2 CO 3 (3.2g, 23.4mmol)} , and the mixture was stirred at reflux for 1 day. After the reaction was completed, the mixture was cooled to room temperature and extracted with distilled water and EA. The obtained organic layer was subjected to distillation under reduced pressure. After column chromatography with MC/Hx, compound H-176 (4.3 g, 64%) was obtained.

The data of the dopant compounds prepared in Examples 5 to 8 and other dopant compounds which can be easily prepared from the examples are shown in Table 1:

Apparatus Example 1: Manufacture of an OLED device using the organic EL compound of the present invention

An organic light emitting diode (OLED) device comprising the luminescent material of the present invention is manufactured by using a transparent electrode indium tin oxide (ITO) film (15 Ω/sq) on a glass substrate for an OLED device (Korea Samsung Corning Co., Ltd.) Samsung Corning, Republic of Korea)), ultrasonic cleaning with trichloroethylene, acetone, ethanol and distilled water, followed by storage in isopropanol. Next, the ITO substrate was mounted on a substrate holder of a vacuum vapor deposition apparatus. N ¹ ,N ^{1 '} -([1,1'-biphenyl]-4,4'-diyl) bis(N ¹ -(naphthalen-1-yl)-N ⁴ ,N ⁴ -diphenylbenzene -1,4-Diamine) is introduced into the cell of the vacuum vapor deposition apparatus, and then the pressure of the chamber of the apparatus is controlled to 10 ^-6 torr. Thereafter, a current was applied to the bath to evaporate the introduced material, thereby forming a hole injection layer having a thickness of 60 nm on the ITO substrate. Next, N,N'-bis(4-biphenyl)-N,N'-bis(4-biphenyl)-4,4'-diaminobiphenyl is introduced into the vacuum vapor deposition apparatus. In another tank, a current is applied to the bath to evaporate the introduced material, thereby forming a hole transport layer having a thickness of 20 nm on the hole injection layer. Compound H-60 was introduced as a host into the bath of the vacuum vapor deposition apparatus, and compound D-3 was introduced as a dopant into another tank. The two materials are evaporated at different rates, and the dopant is deposited at a doping amount of 15 wt% (based on the total weight of the host and the dopant) to form a light having a thickness of 30 nm on the hole transport layer. Floor. Next, 2-(4-(9,10-bis(naphthalen-2-yl)indan-2-yl)phenyl)-1-phenyl-1H-benzo[d]imidazole is introduced into a tank, and Lithium quinolate was introduced into another tank. The two materials were evaporated at the same rate and deposited at a doping amount of 50 wt%, respectively, to form an electron transport layer having a thickness of 30 nm on the light-emitting layer. Next, after depositing lithium hydroxyquinolate as an electron injecting layer having a thickness of 2 nm on the electron transporting layer, an Al cathode having a thickness of 150 nm was deposited on the electron injecting layer by another vacuum vapor deposition apparatus. The OLED device is fabricated in this way. All materials used in the manufacture of the OLED device were purified by vacuum sublimation at 10 ^-6 torr prior to use.

The fabricated OLED device was shown to have a green luminescence with a power efficiency of 44.01 m/W and a luminous intensity of 1620 candles per square meter (cd/m ² ) at 3.6V.

Apparatus Example 2: Manufacture of an OLED device using the organic EL compound of the present invention

The OLED device was fabricated in the same manner as in Device Example 1, except that Compound H-135 was used as the host and Compound D-3 was used as the dopant in the luminescent material.

The fabricated OLED device showed green luminescence with a power efficiency of 56.61 m/W at 2.6 V and an emission intensity of 2190 cd/m ² .

Apparatus Example 3: Manufacture of an OLED device using the organic EL compound of the present invention

The OLED device was fabricated in the same manner as in Device Example 1, except that Compound H-176 was used as the host and Compound D-3 was used as the dopant in the luminescent material.

The fabricated OLED device showed green luminescence with a power efficiency of 51.91 m/W at 2.6 V and an emission intensity of 2510 cd/m ² .

Apparatus Example 4: Manufacture of an OLED device using the organic EL compound of the present invention

An OLED device was fabricated in the same manner as in Device Example 1, except that Compound H-135 was used as the host and Compound D-96 was used as the dopant in the luminescent material.

The fabricated OLED device showed green luminescence with a power efficiency of 47.71 m/W at 2.6 V and an emission intensity of 3140 cd/m ² .

Comparative Example 1: Fabrication of an OLED device using a conventional luminescent material

The OLED device was fabricated in the same manner as in Device Example 1, except that Comparative Compound 1 was used as the host and Compound D-2 was used as the dopant in the luminescent material; a light-emitting layer having a thickness of 30 nm was formed on the hole transport layer. And forming 4-(3-(tris-phenyl-2-ylphenyl)dibenzo[b,d]thiophene having a thickness of 10 nm and serving as a hole barrier layer.

The fabricated OLED device showed green light emission with a power efficiency of 16.81 m/W at 6.9 V and an emission intensity of 3000 cd/m ² .

Comparative compound 1

The organic EL compound of the present invention can provide higher luminous efficiency and lower driving voltage by means of a combination of a specific dopant compound and a host compound in the light-emitting layer, compared to a device including a conventional light-emitting material. Power efficiency, thus reducing power consumption.

Claims (8)

A combination of at least one dopant compound represented by the following formula (1) and at least one host compound represented by the following formula (2), IrL ₁ L ₂ L ₃ (1) wherein each of L ₁ to L _{3 is} independently selected from the following structures The constraint condition is that at least one of L ₁ to L ₃ represents A-1, A-2 or A-3: X represents O or S; R ₁ to R ₁₁ each independently represent hydrogen, deuterium, halogen, cyano, substituted or unsubstituted (C1-C30) alkyl, substituted or unsubstituted (C3-C30) a cycloalkyl group, a substituted or unsubstituted (C6-C30) aryl group, or a substituted or unsubstituted 5 to 30 membered heteroaryl group; and a to h each independently representing an integer from 0 to 4; When h is an integer of 2 or more, each of R ₁ to R ₈ is the same or different, Wherein Y ₁ represents NR ₃₁ ; L ₄ represents a single bond, a substituted or unsubstituted (C6-C30) aryl group, or a substituted or unsubstituted 5 to 30 membered heteroaryl group; each of R ₂₁ to R ₂₃ Independently represents hydrogen, deuterium, halogen, cyano, substituted or unsubstituted (C1-C30) alkyl, substituted or unsubstituted (C6-C30) aryl, substituted or unsubstituted 5 to a 30-membered heteroaryl group, a substituted or unsubstituted thiol group, or a substituted or unsubstituted amine group; or an alicyclic or aromatic ring which is bonded to each other to form a single or polycyclic ring of 3 to 30 members, wherein One or more carbon atoms of the ring may be replaced by at least one hetero atom selected from the group consisting of nitrogen, oxygen and sulfur; Ar ₁ represents a substituted or unsubstituted (C6-C30) aryl group, or substituted or unsubstituted a 5 to 30 membered heteroaryl group containing a nitrogen atom; R ₃₁ represents hydrogen, substituted or unsubstituted (C1-C30) alkyl, substituted or unsubstituted (C6-C30) aryl, or Substituted or unsubstituted 5 to 30 membered heteroaryl; or an alicyclic or aromatic ring which is bonded to each other to form a single or polycyclic ring of 3 to 30 members, wherein one or more carbon atoms of the ring may be at least One selected from nitrogen, And replacement of the sulfur heteroatom; m and o each independently represents an integer of 0 to 4; when m is o or an integer of 2 or more, the same or different and each R ₂₁ or R ₂₃ each line; represents n-0-2 of An integer; when n is 2, each R ₂₂ is the same or different; and the heteroaryl contains at least one hetero atom selected from the group consisting of B, N, O, S, P(=O), Si, and P. The combination of claim 1, wherein R ₁ to R ₁₁ in the compound of the formula (1) each independently represent hydrogen, substituted or unsubstituted (C1-C10) alkyl, substituted or Unsubstituted (C3-C10)cycloalkyl, substituted or unsubstituted (C6-C20) aryl, or substituted or unsubstituted 5 to 20 membered heteroaryl, and in formula (2) In the compound, L ₄ represents a single bond, a substituted or unsubstituted (C6-C20) aryl group, or a substituted or unsubstituted 5 to 20 membered heteroaryl group, and each of R ₂₁ to R ₂₃ independently represents hydrogen. , substituted or unsubstituted (C1-C10)alkyl, substituted or unsubstituted (C6-C20) aryl, substituted or unsubstituted 5 to 20 membered heteroaryl, or substituted or An unsubstituted fluorenyl group, and Ar ₁ represents a substituted or unsubstituted (C6-C20) aryl group, or a substituted or unsubstituted 5 to 20 membered heteroaryl group containing a nitrogen atom. The combination of claim 1, wherein the compound of the formula (1) is represented by the following formula (3), (4) or (5): Wherein R ₁ to R ₆ , a to f, X, L ₂ and L ₃ are as defined in the first item of the patent application. The combination of claim 1, wherein the compound of the formula (2) is represented by one of the following formulas (6) to (11): Wherein R ₂₁ to R ₂₃ , Y ₁ , L ₄ , Ar ₁ , m, n and o are as defined in the first item of the patent application. A combination of claim 3, wherein the compound of the formula (3) is selected from the group consisting of the following structures: The combination of claim 3, wherein the compound of the formula (4) is selected from the group consisting of the following structures: The combination of claim 3, wherein the compound of the formula (5) is selected from the group consisting of the following structures: The combination of claim 4, wherein the compound of the formula (6) to (11) is selected from the group consisting of the following structures: