KR101427620B1 - Novel organic electroluminescent compounds and organic electroluminescent device comprising the same - Google Patents

Abstract

The present invention relates to a novel organic electroluminescent compound and an electroluminescent device comprising the same. The organic electroluminescent compound according to the present invention prevents crystallization during the manufacture of devices by having high electron transfer efficiency and improves current characteristics of the device by preferably forming layers. The device comprising the compound of the present invention does not require a hole blocking layer, while a device comprising a conventional organic electroluminescent compound requires a hole blocking layer, thereby has an advantage of reducing voltage rising factors.

Description

TECHNICAL FIELD The present invention relates to a novel organic electroluminescent compound and an organic electroluminescent device including the organic electroluminescent compound,

The present invention relates to a novel organic electroluminescent compound and an organic electroluminescent device comprising the same.

An electroluminescence device (EL device) is a self-luminous display device having a wide viewing angle, excellent contrast, and fast response speed. In 1987, Eastman Kodak Company first developed an organic EL device using an aromatic diamine and an aluminum complex having a low molecular weight as a material for forming a light emitting layer (Appl. Phys. Lett. 51, 913, 1987].

The most important factor for determining the luminous efficiency in the organic EL device is the luminescent material. As a luminescent material, a fluorescent luminescent material has been widely used, but the development of a phosphorescent luminescent material has been extensively studied in view of the fact that phosphorescent luminescent material can improve luminescent efficiency up to 4 times theoretically compared to a fluorescent luminescent material in the mechanism of electroluminescence . Until now, the iridium (III) complex series has been widely known as a phosphorescent light emitting material, and each of R, G and B has (acac) Ir (btp) ₂ (bis (2- (2'-benzothienyl) -pyridinate- 3 ') iridium (acetylacetonate)), Ir (ppy) ₃ (tris (2-phenylpyridine) iridium) and Firpic (bis (4,6-difluorophenylpyridinate- Collisional iridium) and the like are known.

The light emitting material may be used by mixing a dopant in a host material to improve color purity, luminous efficiency and stability. When using such a dopant / host material system, the choice is important because the host material has a great effect on the efficiency and performance of the light emitting device. In the prior art, 4,4'-N, N'-dicarbazole-biphenyl (CBP) is the most widely known phosphorescent host material. In recent years, Pioneer et al. Of Japan have used bathocuproine (BCP) and aluminum (III) bis (2-methyl-8-quinolinato) (4-phenyl phenolate) (Balq) as a host material to develop a high-performance organic EL device.

However, the conventional phosphorescent host materials are advantageous from the viewpoint of luminescence properties, but they have the following disadvantages: (1) when the glass transition temperature is low and the thermal stability is low, the material undergoes a high temperature deposition process under vacuum, It changes. (2) In the organic EL device, the power efficiency is inversely proportional to the voltage since it is in the relationship of power efficiency = [(pi / voltage) x current efficiency]. However, since the organic EL device using the host material for phosphorescence has a higher current efficiency (cd / A) than the organic EL device using the fluorescent host material, but the driving voltage is also very high, it has a great advantage in terms of power efficiency (lm / w) none. (3) In addition, when used in an organic EL device, it is unsatisfactory in terms of operating life, and luminous efficiency is still required to be improved.

On the other hand, in the organic EL device, as a hole injecting and transporting material, copper phthalocyanine (CuPc), 4,4'-bis [N- (1-naphthyl) -N- phenylamino] biphenyl (NPB) (TPD), 4,4 ', 4 "-tris (3-methylphenylphenylamino) diphenyl-N, N'-bis ), Triphenylamine (MTDATA) and the like have been used. However, when such a material is used, there is a problem that the quantum efficiency and the lifetime of the organic EL device are lowered because when the organic EL device is driven at a high current, Since the thermal stress is generated between the injection layers, and the lifetime of the device is rapidly lowered due to the thermal stress. Further, since the organic material used for the hole injection layer has a high mobility of holes, The electron-hole charge balance is broken and the quantum efficiency (cd / A) is lowered.

Korean Patent Laid-Open Publication No. 2011-0066763 discloses an indoloacridine compound as a compound for an organic EL device. However, the organic EL devices including the compounds disclosed in the above document still have a voltage increase factor due to the high driving voltage and the hole blocking layer.

Thus, in the present invention, it has been found that by using a phosphorescent host compound having excellent electron transfer efficiency in the light emitting layer of an organic EL device, the charge balance between holes and electrons in the light emitting layer is well performed, the driving voltage of the device is lowered and the power efficiency is improved . In addition, the organic EL device including the host material has an advantage that the voltage increase factor is reduced because a hole blocking layer is not required.

Korean Published Patent Application No. 2011-0066763 (June 17, 2011)

Accordingly, an object of the present invention is to provide an organic electroluminescent compound having a low driving voltage and improved power efficiency, which comprises the organic electroluminescent compound in a light emitting layer, .

As a result of intensive studies to solve the above technical problems, the present inventors have found that a compound represented by the following general formula (1) achieves the above-mentioned object and completed the present invention.

[Chemical Formula 1]

In Formula 1,

L ₁ to L ₃ are each independently a single bond, substituted or unsubstituted (3-30 membered heteroarylene, substituted or unsubstituted (C 6 -C 30) arylene, or (C 1 -C 30) alkylene,

A ₁ to A ₃ each independently represent the following,

X ₁ And X ₂ is Each independently CR < ₃ > or N,

Y is -O-, -S- or -NR < ₁₂ > -,

R ₁ and R ₂ are each independently selected from the group consisting of hydrogen, deuterium, halogen, cyano, carboxyl, nitro, hydroxy, substituted or unsubstituted (C 1 -C 30) alkyl, substituted or unsubstituted (C 3 -C 30) , Substituted or unsubstituted (C3-C30) cycloalkenyl, substituted or unsubstituted (3-7 membered) heterocycloalkyl, substituted or unsubstituted (C6-C30) -30) heteroaryl, or R ₁ and R ₂ may be fused to form a substituted or unsubstituted (C3-C30) monocyclic or polycyclic alicyclic or aromatic ring,

R ₃ to R ₇ and R ₁₂ are each independently selected from the group consisting of hydrogen, deuterium, halogen, substituted or unsubstituted (C 1 -C 30) alkyl, substituted or unsubstituted (C 6 -C 30) Substituted or unsubstituted (C6-C30) aryl (C1-C30) heteroaryl, substituted or unsubstituted (C3-C30) cycloalkyl, substituted or unsubstituted (5-7 membered) heterocycloalkyl, _{alkyl, -NR 13 R 14, -SiR 15} R 16 R 17, -SR 18, -OR 19, cyano, and nitro, or hydroxy,

R ₁₀ and R ₁₁ are each independently selected from the group consisting of hydrogen, deuterium, halogen, substituted or unsubstituted (C 1 -C 30) alkyl, substituted or unsubstituted (C 6 -C 30) ) Heteroaryl,

R ₁₃ to R ₁₉ each independently represent hydrogen, deuterium, halogen, substituted or unsubstituted (C 1 -C 30) alkyl, substituted or unsubstituted (C 6 -C 30) aryl, substituted or unsubstituted Substituted or unsubstituted (5- to 7-membered) heterocycloalkyl, substituted or unsubstituted (C3-C30) cycloalkyl, or substituted or unsubstituted (3-30 membered) monocyclic Or a polycyclic alicyclic or aromatic ring, and the carbon atom of the alicyclic or aromatic ring may be substituted with one or more heteroatoms selected from nitrogen, oxygen and sulfur,

Wherein said heteroaryl and said heterocycloalkyl comprise at least one heteroatom selected from B, N, O, S, P (= O), Si and P,

a, c, and d are each independently an integer of 1 to 4; when R is an integer of 2 or more, each R ₄ , each R _6, or each R ₇ may be the same or different,

b is an integer of 1,

l, m and n are each independently 0 or 1, and l + m + n is 1 or more.

Since the organic electroluminescent compound according to the present invention has high electron transfer efficiency, it is possible to prevent the crystallization during the fabrication of the device and improve the current characteristics of the device due to good layer formation, thereby lowering the driving voltage of the device and improving the power efficiency. A device including the organic electroluminescent compound requires a hole blocking layer. However, a device including the compound of the present invention has an advantage that a voltage rising factor is reduced because a hole blocking layer is not needed.

The present invention will now be described in more detail, but this should not be construed as limiting the scope of the present invention.

The present invention relates to an organic electroluminescent compound represented by Formula 1, an organic electroluminescent material including the organic electroluminescent compound, and an organic electroluminescent device including the same.

The compound of formula (I) of the present invention is preferably a compound wherein L ₁ to L ₃ are each independently a single bond or a substituted or unsubstituted (C 6 -C 30) arylene, R ₁ and R ₂ are each independently substituted or unsubstituted hwandoen (C1-C30) alkyl, or substituted or unsubstituted (C6-C30) aryl, R ₁ and R ₂ is a fused substituted or unsubstituted (C3-C30) monocyclic or polycyclic alicyclic or aromatic And R ₃ to R ₇ and R ₁₂ are each independently hydrogen, substituted or unsubstituted (C 1 -C 30) alkyl, substituted or unsubstituted (C 6 -C 30) aryl, substituted or unsubstituted (3-30 W) is heteroaryl, or -SiR ₁₅ R ₁₆ R ₁₇ and, R ₁₀ and R ₁₁ are each independently hydrogen or a substituted or unsubstituted (C6-C30) aryl.

The compound of formula (1) of the present invention is preferably represented by the following formula (2).

(2)

In Formula 2,

The definition of L ₁ to L ₃ , A ₁ to A ₃ , X ₁ and X ₂ , Y, R ₃ to R ₇ , R ₁₀ to R ₁₉ , a, b, c, d, 1 < / RTI >

e and f are the same as the definitions of a, c and d in the formula (1)

R ₈ And R ₉ is the same as the definition of R ₄ to R ₇ in the formula (1),

A ₄ is the same as defined for A ₁ to A ₃ in the above formula (1)

L ₄ is the same as L ₁ to L ₃ in the above formula (1).

The term "(C1-C30) alkyl (phenylene)" as used in the present invention means a linear or branched alkylene having 1 to 30 carbon atoms, wherein the number of carbon atoms is preferably 1 to 20, 10 is preferable. Specific examples of the alkyl include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl and tert-butyl. As used herein, "(C2-C30) alkenyl" means straight or branched chain alkenyl having 2 to 30 carbon atoms, preferably 2 to 20 carbon atoms, more preferably 2 to 10 carbon atoms. Specific examples of the alkenyl include vinyl, 1-propenyl, 2-propenyl, 1-butenyl, 2-butenyl, 3-butenyl, 2-methylbut-2-enyl and the like. As used herein, "(C2-C30) alkynyl" means straight or branched chain alkynyl having 2 to 30 carbon atoms, preferably 2 to 20 carbon atoms, more preferably 2 to 10 carbon atoms. Examples of the alkynyl include ethynyl, 1-propynyl, 2-propynyl, 1-butynyl, 2-butynyl, 3-butynyl and 1-methylpent-2-onyl. The term "(C3-C30) cycloalkyl" as used herein means a monocyclic or polycyclic hydrocarbon having 3 to 30 carbon atoms, preferably 3 to 20 carbon atoms, more preferably 3 to 7 carbon atoms. Examples of the cycloalkyl include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl and the like. The term " (3-7 member) heterocycloalkyl "as used herein means a heterocycloalkyl group having 3 to 7, preferably 5 to 7, ring skeletal atoms and consisting of B, N, O, S, P Means one or more heteroatoms selected from the group consisting of O, S and N, and includes, for example, tetrahydrofuran, pyrrolidine, thiolane, tetrahydropyran, etc. . The term "(C6-C30) aryl (phenylene)" as used herein refers to a monocyclic or fused ring radical derived from an aromatic hydrocarbon having 6 to 30 carbon atoms, wherein the number of carbon atoms in the ring skeleton is preferably 6 to 20, 15 < / RTI > Examples of such aryls include phenyl, biphenyl, terphenyl, naphthyl, fluorenyl, phenanthrenyl, anthracenyl, indenyl, triphenylenyl, pyrenyl, tetracenyl, perylenyl, , Fluoranthenyl, and the like. The term "(3-30) heteroaryl (phenylene)" used herein refers to a heteroaryl group having 3 to 30 ring skeletal atoms and one or more heteroatoms selected from the group consisting of B, N, O, S, P Quot; means an aryl group containing an atom. Here, the number of the atoms of the ring skeleton is preferably 3 to 20, more preferably 3 to 15. The number of heteroatoms is preferably 1 to 4, and may be a monocyclic ring system or a fused ring system condensed with at least one benzene ring, and may be partially saturated. In addition, the heteroaryl (phenylene) in the present invention also includes a form in which one or more heteroaryl groups or aryl groups are linked to a heteroaryl group by a single bond. Examples of such heteroaryls include furyl, thiophenyl, pyrrolyl, imidazolyl, pyrazolyl, thiazolyl, thiadiazolyl, isothiazolyl, isoxazolyl, oxazolyl, oxadiazolyl, triazinyl, tetrazinyl , Monocyclic heteroaryl such as triazolyl, tetrazolyl, furanzyl, pyridyl, pyrazinyl, pyrimidinyl and pyridazinyl, benzofuranyl, benzothiophenyl, isobenzofuranyl, dibenzofuranyl, di Benzoimidazolyl, benzothiazolyl, benzothiazolyl, benzoisothiazolyl, benzooxazolyl, isoindolyl, indolyl, indazolyl, benzothiadiazolyl, quinolyl, isoquinolyl, Fused heterocyclic heteroaryl such as norbornyl, quinazolinyl, quinoxalinyl, carbazolyl, phenoxaphyl, phenanthridinyl, benzodioxolyl and the like. As used herein, "halogen" includes F, Cl, Br, and I atoms.

Also, in the phrase "substituted or unsubstituted" described in the present invention, "substituted" means that a hydrogen atom is replaced with another atom or another functional group (ie, a substituent) in a certain functional group. Substituted (C1-C30) alkyl, substituted (C3-C30) cycloalkyl, substituted (C3-C30) cycloalkenyl, substituted in the formulas (1) and (2) of the L ₁ to L _4, and R ₁ to R ₁₉ of the present invention ( (C6-C30) aryl (R), substituted (3-30 membered heteroaryl), and substituted (3-30 membered) monocyclic or polycyclic alicyclic or aromatic rings (C2-C30) alkyl, (C2-C30) alkenyl, (C2-C30) alkoxy, (C1-C30) alkylthio, (C3-C30) cycloalkyl, (C3-C30) cycloalkenyl, (3-7 membered) heterocycloalkyl, (C6- C6-C30 aryl optionally substituted with (C3-C30) arylthio, (C6-C30) aryl, (3-30 membered) heteroaryl optionally substituted with (C6-C30) arylsilyl, tri (C6-C30) arylsilyl, di (C1- , Ah (C1-C30) alkylamino, mono or di (C6-C30) arylamino, (C1-C30) (C1-C30) alkylcarbonyl, (C6-C30) arylcarbonyl, di (C6-C30) arylboronyl, di (C6-C30) aryl (C1-C30) alkyl and (C1-C30) alkyl (C6-C30) aryl.

Examples of the organic electroluminescent compound according to the present invention include the following compounds.

The organic electroluminescent compound according to the present invention can be prepared by a synthesis method known to a person skilled in the art and can be prepared, for example, according to the following reaction formula.

The present invention also provides an organic electroluminescent material comprising an organic electroluminescent compound of Formula 1 and an organic electroluminescent device comprising the same.

The material may be made of the organic electroluminescent compound of the present invention alone, and may further include common materials included in the organic electroluminescent material.

An organic electroluminescent device according to the present invention includes a first electrode; A second electrode; And at least one organic material layer interposed between the first electrode and the second electrode, and the organic material layer may include at least one organic electroluminescent compound of Formula 1 of the present invention.

One of the first electrode and the second electrode may be an anode and the other may be a cathode. The organic material layer may further include one or more layers selected from the group consisting of a hole injection layer, a hole transport layer, an electron transport layer, an electron injection layer, an interlayer and an electron blocking layer.

The organic electroluminescent compound of the present invention may be included in the light emitting layer. When used in the light emitting layer, the organic electroluminescent compound of the present invention may be included as a host material.

The organic electroluminescent device including the organic electroluminescent compound of the present invention may further include at least one other compound other than the organic electroluminescent compound of the present invention as a host material, and may further include at least one dopant.

When the organic electroluminescent compound of the present invention is contained as the host material (first host material) of the light emitting layer, other compounds may be included as the second host material. Here, the weight ratio of the first host material to the second host material ranges from 1:99 to 99: 1.

The host material of the compound other than the organic electroluminescent compound of the present invention may be any phosphorescent host known in the art, but is preferably selected from the group consisting of compounds represented by the following formulas (3) to (5) Do.

(3)

_{H- (Cz-L 4) h} -M

[Chemical Formula 4]

H- (Cz) _i -L ₄ -M

[Chemical Formula 5]

In the above formulas 3 to 5,

Cz has the following structure,

R ₂₁ to R ₂₄ each independently represent hydrogen, deuterium, halogen, substituted or unsubstituted (C 1 -C 30) alkyl, substituted or unsubstituted (C 6 -C 30) aryl, substituted or unsubstituted Heteroaryl, or R ₂₅ R ₂₆ R ₂₇ Si-, which may be connected to adjacent substituents to form a (5-30 membered) monocyclic or polycyclic alicyclic or aromatic ring, wherein the carbon atom of the alicyclic or aromatic ring is nitrogen Lt; / RTI > may be replaced by one or more heteroatoms selected from oxygen, sulfur and sulfur; R ₂₅ to R ₂₇ are each independently a substituted or unsubstituted (C 1 -C 30) alkyl, or a substituted or unsubstituted (C 6 -C 30) aryl; L ₄ is a single bond, substituted or unsubstituted (C6-C30) arylene, or substituted or unsubstituted (5-30 membered) heteroarylene; M is a substituted or unsubstituted (C6-C30) aryl, or a substituted or unsubstituted (5-30 membered) heteroaryl; Y ₁ and Y ₂ are -O-, -S-, -N (R ₃₁ ) - or -C (R ₃₂ ) (R ₃₃ ) -, and Y ₁ and Y ₂ are not simultaneously present; R ₃₁ to R ₃₃ are each independently a substituted or unsubstituted (C 1 -C 30) alkyl, a substituted or unsubstituted (C 6 -C 30) aryl, a substituted or unsubstituted (5-30 membered) (5-30 membered) monovalent or polycyclic alicyclic or aromatic ring, and the carbon atom of the alicyclic or aromatic ring may be substituted with one or more heteroatoms selected from nitrogen, oxygen and sulfur ; R ₃₂ and R ₃₃ may be the same or different; each of h and i is independently an integer of 1 to 3, j, k, l and m are each independently an integer of 0 to 4, and when h, i, j, k, l or m is an integer of 2 or more, (Cz-L ₄ ), each (Cz), each R ₂₁ , each R ₂₂ , each R _23, or each R ₂₄ may be the same or different.

Specifically, preferred examples of the second host material are as follows.

 [Wherein TPS is triphenylsilyl]

As the dopant included in the organic electroluminescent device of the present invention, at least one phosphorescent dopant is preferable. The phosphorescent dopant material to be applied to the organic electroluminescent device of the present invention is not particularly limited, but is preferably a complex compound of a metal atom selected from iridium (Ir), osmium (Os), copper (Cu) and platinum (Pt) , An iridium (Ir), an osmium (Os), a copper (Cu) and a platinum (Pt) are more preferable, and an orthometallated iridium complex compound is even more preferable.

The phosphorescent dopant is preferably selected from the group consisting of compounds represented by the following Chemical Formulas (6) to (8).

 [Chemical Formula 7] < EMI ID =

In Formulas 6 to 8, L is selected from the following structures;

R ₁₀₀ is hydrogen, substituted or unsubstituted (C 1 -C 30) alkyl, or substituted or unsubstituted (C 3 -C 30) cycloalkyl; R ₁₀₁ to R ₁₀₉ and R ₁₁₁ to R ₁₂₃ are each independently selected from the group consisting of hydrogen, deuterium, halogen, (C 1 -C 30) alkyl substituted or unsubstituted with halogen, substituted or unsubstituted (C 3 -C 30) , Or substituted or unsubstituted (C1-C30) alkoxy; R ₁₂₀ to R ₁₂₃ are connected to adjacent substituents to form a fused ring, for example, quinoline formation is possible; R ₁₂₄ to R ₁₂₇ are each independently hydrogen, deuterium, halogen, substituted or unsubstituted (C 1 -C 30) alkyl, or substituted or unsubstituted (C 6 -C 30) aryl; When R ₁₂₄ to R ₁₂₇ are aryl groups, they are fused to adjacent groups to form a fused ring, for example fluorene formation is possible; R ₂₀₁ to R ₂₁₁ each independently represents hydrogen, deuterium, halogen, (C1-C30) alkyl substituted or unsubstituted with halogen, substituted or unsubstituted (C3-C30) ; f and g are each independently an integer of 1 to 3, and when f or g is an integer of 2 or more, each R ₁₀₀ may be the same or different from each other; n is an integer of 1 to 3;

Specific examples of the phosphorescent dopant material are as follows.

The present invention provides a composition for preparing an organic electroluminescent device in a further aspect. The composition comprises a compound of the present invention as a host material.

Further, the organic electroluminescent device of the present invention includes a first electrode; A second electrode; And at least one organic material layer interposed between the first electrode and the second electrode, wherein the organic material layer includes a light emitting layer, and the light emitting layer may include the composition for an organic electroluminescent device of the present invention.

The organic electroluminescent device of the present invention includes the organic electroluminescent compound of Formula 1, and at the same time, may include one or more compounds selected from the group consisting of an arylamine-based compound and a styrylarylamine-based compound.

In addition, in the organic electroluminescent device of the present invention, in addition to the organic electroluminescent compound of Formula 1, an organic electroluminescent compound of Group 1, 2, 4, and 5 period transition metals, lanthanide series and d- And the organic compound layer may further include a light emitting layer and a charge generating layer.

In addition, the organic electroluminescent device of the present invention may emit white light by including at least one light emitting layer containing a blue, red or green light emitting compound known in the art, in addition to the compound of the present invention. Further, if necessary, it may further include a yellow or orange light emitting layer.

In the organic electroluminescent device of the present invention, at least one layer selected from a chalcogenide layer, a metal halide layer and a metal oxide layer (hereinafter referred to as " surface layer "Quot;). Concretely, it is preferable to arrange a layer of a chalcogenide (including an oxide) of silicon and aluminum metal on the surface of the anode on the side of the light emitting medium layer and a metal halide layer or metal oxide layer on the surface of the cathode on the side of the light emitting medium layer . Stabilization of driving can be obtained by the surface layer. Preferable examples of the chalcogenide include SiO _X (1? _X ? 2), AlO _x (1? _X ? 1.5), SiON or SiAlON. Preferred examples of the halogenated metal include LiF, MgF ₂ , CaF ₂ , Rare-earth metals, etc. Preferred examples of the metal oxides include Cs ₂ O, Li ₂ O, MgO, SrO, BaO, CaO and the like.

In the organic electroluminescent device of the present invention, it is also preferable to arrange a mixed region of the electron transport compound and the reducing dopant or a mixed region of the hole transport compound and the oxidative dopant on at least one surface of the pair of electrodes. In this way, since the electron transport compound is reduced to an anion, it becomes easy to inject and transport electrons from the mixed region into the light emitting medium. Further, since the hole transporting compound is oxidized and becomes a cation, it becomes easy to inject and transport holes from the mixed region into the light emitting medium. Preferred oxidizing dopants include various Lewis acids and acceptor compounds, and preferred reducing dopants include alkali metals, alkali metal compounds, alkaline earth metals, rare earth metals, and mixtures thereof. Further, a white light emitting organic electroluminescent device having two or more light emitting layers can be manufactured using a reductive dopant layer as a charge generation layer.

The formation of each layer of the organic electroluminescent device of the present invention may be performed by a dry film formation method such as vacuum deposition, sputtering, plasma or ion plating, or a wet film formation method such as spin coating, dip coating or flow coating Can be applied.

In the case of the wet film formation method, a thin film is formed by dissolving or dispersing a material forming each layer in an appropriate solvent such as ethanol, chloroform, tetrahydrofuran, dioxane, etc., And it may be any thing that does not have a problem in the tabernacle.

Hereinafter, the organic electroluminescent compound according to the present invention, the method for producing the same, and the luminescent characteristics of the device will be described with reference to the representative compound of the present invention for a detailed understanding of the present invention.

[ Example  1] Preparation of compound H-2

Preparation of compound H-2-2

2L round bottom flask the compound H-2-1 (60g, 263mmol) , 2- bromo-nitrobenzene (44.2g, 219mmol), tetrakis (triphenylphosphine) palladium _{[Pd (PPh 3) 4]} (7.6g, K ₂ CO ₃ (60.5 g, 438 mmol), toluene (900 ml), ethanol (EtOH) (220 ml) and H ₂ O (220 ml) were added and stirred under reflux. After 5 h, the mixture was extracted with dichloromethane (DCM) and H ₂ O, the DCM layer was dried over MgSO ₄ and filtered. The resulting solid was dissolved in chloroform (CHCl ₃ ) and subjected to silica gel column chromatography to obtain a compound H-2-2 (74.8 g, 93%).

Preparation of compound H-2-3

(74.8 g, 245 mmol), triethyl phosphite [P (OEt) ₃ ] (500 ml) and 1,2-dichlorobenzene (1,2-DCB) (200 ml) were placed in a 1 L round- And the mixture was refluxed and stirred. After 13 hours, the solvent was distilled off and the residue was dissolved in CHCl ₃ and subjected to silica gel column chromatography to obtain compound H-2-3 (38 g, 56%).

Preparation of compound H-2-4

1L round bottom flask the compound H-2-3 (27g, 98.7mmol) , 1,2- dibromo-benzene (46.6g, 197.5mmol), copper powder _{(3.1g, 49.35mmol), K 2} CO 3 (27.3g , 197.5 mmol) and 1,2-DCB (500 ml) were added, and the mixture was stirred under reflux. After 23 hours, the solvent was distilled off and the resulting solid was dissolved in CHCl ₃ and subjected to silica gel column chromatography to obtain compound H-2-4 (28.19 g, 67%).

Preparation of compound H-2-5

Compound H-2-4 (28.19 g, 66 mmol) was added to a 1 L round-bottomed flask, and 300 ml of tetrahydrofuran (THF) was added and cooled to -78 ^° C. 2.5M n-butyllithium (34.2 ml, 85.5 mmol) was added thereto, and 2 hours later, 2-bromo-9-fluorenone (22.2 g, 85.5 mmol) was added. After 18 h, the mixture was extracted with methylene chloride (MC) and H ₂ O and the MC layer was dried over MgSO ₄ . The MC layer was filtered and concentrated to give the compound H-2-5 (35.3 g, 91%).

Preparation of compound H-2-6

Compound H-2-5 (35.3 g, 60 mmol) was added to a 1 L round-bottomed flask, and hydrochloric acid (80 ml) and acetic acid (600 ml) were added and stirred under reflux. After 14 h the resulting solid was filtered and the filtered solid was dissolved in CHCl ₃ and subjected to silica gel column chromatography to give 27.9 g (78%) of the compound H-2-6.

Preparation of compound H-2-7

To a 1 L round bottom flask was added a solution of compound H-2-6 (28 g, 47.2 mmol), bis (pinacolato) diborane (13.2 g, 52 mmol), potassium acetate (KOAc) (7.7 g, 94.4 mmol) (500 ml) were added, and the mixture was stirred under reflux. After 3 hours, the mixture was extracted with DCM and H ₂ O, the DCM layer was dried over MgSO ₄ and filtered. The resulting solid was dissolved in CHCl ₃ and subjected to silica gel column chromatography to obtain compound H-2-7 (9 g, 31%).

Preparation of Compound H-2

250ml round bottom flask the compound H-2-7 (8.3g, 13mmol) , compound H-3-2 (5.2g, 19.5mmol) , Pd (PPh 3) 4 (450mg, 0.39mmol), K 2 CO 3 (3.6 g, 26 mmol), toluene (100 ml) and H ₂ O (13 ml) were added, and the mixture was stirred under reflux. After 3 hours, the mixture was extracted with DCM and H ₂ O, the DCM layer was dried over MgSO ₄ and filtered. The resulting solid was dissolved in CHCl ₃ and subjected to silica gel column chromatography to obtain Compound H-2 (2.5 g, 26%).

[device Example  1] The organic Field  Using a luminescent compound OLED  Device fabrication

An OLED device comprising the organic electroluminescent compound of the present invention was prepared as follows. First, a transparent electrode ITO thin film (15 OMEGA / square) obtained from a glass for OLED (manufactured by Samsung Corning) was subjected to ultrasonic cleaning using trichlorethylene, acetone, ethanol and distilled water sequentially and then stored in isopropanol Respectively. Next, an ITO substrate was mounted on a substrate holder of a vacuum deposition apparatus, and N ¹ , N ^{1 '} - ([1,1'-biphenyl] -4,4'-diyl) bis ¹ - (naphthalene- ¹ -yl) -N ⁴ , N ⁴ -diphenylbenzene-1,4-diamine) was added and the chamber was evacuated until the degree of vacuum reached 10 ^-6 torr. And evaporated to deposit a 60 nm thick hole injection layer on the ITO substrate. Subsequently, N, N'-di (4-biphenyl) -N, N'-di (4-biphenyl) -4,4'- diaminobiphenyl was added to another cell in the vacuum vapor- Was evaporated to deposit a hole transport layer having a thickness of 20 nm on the hole injection layer. Compound H-2 of the present invention was added as a host to one cell in a vacuum evaporation apparatus and Compound D-1 was added as a dopant to another cell. Then, the two substances were evaporated at different rates to form a dopant of 15 A light emitting layer with a thickness of 30 nm was deposited on the hole transporting layer by doping with an amount of 0.5 wt%. Subsequently, 2- (4- (9,10-di (naphthalen-2-yl) anthracen-2-yl) phenyl) -1-phenyl-1H- benzo [d] imidazole was added to one cell, Lithium quinolate was added, and the two materials were evaporated at the same rate and doped in an amount of 50 wt%, respectively, to deposit an electron transport layer of 30 nm on the light emitting layer. Then, lithium quinolate was deposited to a thickness of 2 nm as an electron injecting layer, and then an Al cathode was deposited to a thickness of 150 nm using another vacuum vapor deposition equipment to fabricate an OLED device. Each compound was purified by vacuum sublimation under 10 ^-6 torr.

As a result, a current of 3.84 mA / cm ² flowed at a voltage of 2.6 V, and green emission of 1640 cd / m ² was confirmed.

[ Comparative Example  1] Using conventional light emitting materials OLED  Device fabrication

As a light emitting material, 4,4'-N, N'-dicarbazole-biphenyl was used as a host and Compound D-86 was used as a dopant. A 30 nm thick light emitting layer was deposited on the hole transporting layer, (III) bis (2-methyl-8-quinolinato) -4-phenylphenolate was deposited to a thickness of 10 nm, an OLED device was fabricated in the same manner as in Example 1.

As a result, a current of 8.56 mA / cm ² flowed at a voltage of 5.8 V, and green light emission of 3000 cd / m ² was confirmed.

[device Example  2] The organic Field  Using a luminescent compound OLED  Device fabrication

Compound H-2 of the present invention was added as a host to one cell in a vacuum vapor deposition apparatus and Compound D-88 was added as another dopant to another cell. Then, the two substances were evaporated at different rates to form a dopant for the host and the dopant. A light emitting layer with a thickness of 30 nm was deposited on the hole transporting layer by doping with an amount of 0.5 wt%. Subsequently, 2- (4- (9,10-di (naphthalen-2-yl) anthracen-2-yl) phenyl) -1-phenyl-1H- benzo [d] imidazole was added to one cell, Lithium quinolate was added, and then the two materials were evaporated at the same rate to each other to be doped with 50% by weight to deposit an electron transporting layer of 30 nm on the light emitting layer. Thus, an OLED device was manufactured in the same manner as in Example 1.

As a result, a current of 19.0 mA / cm ² flowed at a voltage of 4.1 V, and red light emission of 1570 cd / m ² was confirmed.

[ Comparative Example  2] Using a conventional light emitting material OLED  Device fabrication

(III) bis (2-methyl-naphthalen-2-yl) benzene was used as a hole blocking layer, and a light emitting layer having a thickness of 30 nm was deposited on the hole transport layer using 4,4'- 8-quinolinato) 4-phenylphenolate was deposited to a thickness of 10 nm, and the compound D-88 was used as the dopant.

As a result, a current of 20.0 mA / cm ² flowed at a voltage of 8.2 V, and red luminescence of 1000 cd / m ² was confirmed.

Since the organic electroluminescent compound according to the present invention has high electron transfer efficiency, it is possible to prevent the crystallization during the fabrication of the device and improve the current characteristics of the device due to good layer formation, thereby lowering the driving voltage of the device and improving the power efficiency. A device including the organic electroluminescent compound requires a hole blocking layer. However, a device including the compound of the present invention has an advantage that a voltage rising factor is reduced because a hole blocking layer is not needed.

Claims (6)

An organic electroluminescent compound represented by the following formula (1).
[Chemical Formula 1]

In Formula 1,
L ₁ to L ₃ are each independently a single bond, substituted or unsubstituted (3-30 membered heteroarylene, substituted or unsubstituted (C 6 -C 30) arylene, or (C 1 -C 30) alkylene,
A ₁ to A ₃ each independently represent the following,

X ₁ and X ₂ are Each independently CR < ₃ > or N,
Y is -O-, -S- or -NR < ₁₂ > -,
R ₁ and R ₂ are each independently a substituted or unsubstituted (C 1 -C 30) alkyl, or a substituted or unsubstituted (C 6 -C 30) aryl, or R ₁ and R ₂ are fused to form a substituted or unsubstituted -C30) monocyclic or polycyclic alicyclic or aromatic ring,
R ₃ to R ₇ and R ₁₂ are each independently selected from the group consisting of hydrogen, deuterium, halogen, substituted or unsubstituted (C 1 -C 30) alkyl, substituted or unsubstituted (C 6 -C 30) Substituted or unsubstituted (C6-C30) aryl (C1-C30) heteroaryl, substituted or unsubstituted (C3-C30) cycloalkyl, substituted or unsubstituted (5-7 membered) heterocycloalkyl, _{alkyl, -NR 13 R 14, -SiR 15} R 16 R 17, -SR 18, -OR 19, cyano, and nitro, or hydroxy,
R ₁₀ and R ₁₁ are each independently selected from the group consisting of hydrogen, deuterium, halogen, substituted or unsubstituted (C 1 -C 30) alkyl, substituted or unsubstituted (C 6 -C 30) ) Heteroaryl,
R ₁₃ to R ₁₉ each independently represent hydrogen, deuterium, halogen, substituted or unsubstituted (C 1 -C 30) alkyl, substituted or unsubstituted (C 6 -C 30) aryl, substituted or unsubstituted Substituted or unsubstituted (5- to 7-membered) heterocycloalkyl, substituted or unsubstituted (C3-C30) cycloalkyl, or substituted or unsubstituted (3-30 membered) monocyclic Or a polycyclic alicyclic or aromatic ring, and the carbon atom of the alicyclic or aromatic ring may be substituted with one or more heteroatoms selected from nitrogen, oxygen and sulfur,
Wherein said heteroaryl and said heterocycloalkyl comprise at least one heteroatom selected from B, N, O, S, P (= O), Si and P,
a, c, and d are each independently an integer of 1 to 4; when R is an integer of 2 or more, each R ₄ , each R _6, or each R ₇ may be the same or different,
b is an integer of 1,
l, m and n are each independently 0 or 1. The organic electroluminescent compound according to claim 1, wherein the compound of Formula 1 is represented by Formula 2 below.
(2)

In Formula 2,
The definition of L ₁ to L ₃ , A ₁ to A ₃ , X ₁ and X ₂ , Y, R ₃ to R ₇ , R ₁₀ to R ₁₉ , a, b, c, d, Lt; / RTI >< RTI ID =
e and f are the same as the definitions of a, c and d in claim 1,
R ₈ and R ₉ are the same as defined for R ₄ to R ₇ in claim 1,
A ₄ is the same as the definition of A ₁ to A ₃ in claim 1,
L < _{4 & gt} ; are the same as defined in L &_lt; ₁ > to L &_lt; ₃ > 3. The compound according to claim 1 or 2, wherein said L ₁ to L ₄ and R ₁ to R ₁₉ are substituted (C1-C30) alkyl, substituted (C3-C30) cycloalkyl, substituted (C3-C30) , Substituted (3-7 membered) heterocycloalkyl, substituted (C6-C30) aryl (phenylene), substituted (3-30 membered heteroaryl), and substituted (3-30 membered) monocyclic or polycyclic alicyclic (C1-C30) alkyl, (C2-C30) alkenyl, (C2-C30) alkynyl, (C3-C30) cycloalkyl, (C3-C30) cycloalkenyl, (3-7 membered) heterocycloalkyl, (C6-C30) alkynyl, (3-30 membered heteroaryl) optionally substituted with (C6-30) aryloxy, (C6-C30) arylthio, (C6-30) aryl, (C6-C30) aryl, tri (C1-C30) alkylsilyl, tri (C6-C30) arylsilyl, di ) Aryl (C1-C30) alkylamino, mono or di (C6-C30) arylamino, (C1-C30) alkyl (C1-C30) alkylcarbonyl, (C6-C30) arylcarbonyl, di (C6-C30) arylboronyl, di (C6-C30) aryl (C1-C30) alkyl and (C1-C30) alkyl (C6-C30) aryl. The compound according to Claim 1, wherein L ₁ to L ₃ are each independently a single bond or substituted or unsubstituted (C 6 -C 30) arylene, R ₁ and R ₂ are each independently a substituted or unsubstituted (C1- C30) alkyl, or substituted or unsubstituted (C6-C30) aryl, R ₁ and R ₂ are fused to form a substituted or unsubstituted monocyclic or polycyclic alicyclic or aromatic ring-substituted (C3-C30) And R ₃ to R ₇ and R ₁₂ each independently represent hydrogen, substituted or unsubstituted (C 1 -C 30) alkyl, substituted or unsubstituted (C 6 -C 30) aryl, substituted or unsubstituted ) heteroaryl, or -SiR ₁₅ R ₁₆ R ₁₇ and, R ₁₀ and R ₁₁ are each independently hydrogen, or substituted or unsubstituted (C6-C30) aryl, the organic electroluminescent compounds. The organic electroluminescent compound according to claim 1, wherein the compound represented by the formula (1) is selected from the following compounds.

An organic electroluminescent device comprising the compound according to claim 1.