TW201520308A - 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 organic electroluminescent device comprising the same. The organic electroluminescent compound according to the present invention can be used in a light- emitting layer and has high luminous efficiency. Thus, an organic electroluminescent device having a long driving lifespan and improved current and power efficiencies can be prepared by using the organic electroluminescent compound according to the present invention.

Description

Novel organic electroluminescent compound and organic electric field illuminating device comprising the same

The present invention relates to novel organic electroluminescent compounds and organic electroluminescent devices comprising the same.

The electric field illuminating device (EL device) is a self-illuminating device which has the advantages of providing a wider viewing angle, a larger contrast ratio, and a faster response time. The organic EL device was first developed by Eastman Kodak, using a small aromatic diamine molecule, and an aluminum complex as a material for forming a light-emitting layer [Appl. Phys. Lett. 51, 913, 1987] .

An organic EL device generally has a structure including an anode, a cathode, and an organic layer interposed between the anode and the cathode, and emits light via a combination of a hole and an electron emitted from the anode and the cathode. The organic layer of the organic EL device may be composed of a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, an electron injection layer, etc., and the material used for the organic layer is classified as a hole injection material, electricity Hole transport material, luminescent material, electricity Sub-transport material, electron injecting material, and the like.

The most important factor determining the luminous efficiency in an organic EL device is a luminescent material. The luminescent material must have high quantum efficiency, high electron and hole mobility, and the luminescent material layer to be formed must be uniform and stable. The luminescent materials are classified into blue, green, and red luminescent materials depending on the color of the luminescence. In addition, there are also yellow and green luminescent materials. Depending on the state of the laser, the luminescent material can also be classified into a fluorescent (single-state) luminescent material and a phosphorescent (triplet) luminescent material. In the early stage, fluorescent materials were mainly used in organic EL devices. However, the phosphorescent material enhances the efficiency of converting light into electricity, that is, the luminous efficiency is four (4) times higher than that of the fluorescent material, and the power consumption can be reduced to relatively extend the life, so the phosphorescent material is Development is being studied extensively.

The ruthenium (III) complex has been widely used as a phosphorescent material, including bis(2-(2'-benzothienyl)-pyridine-N,C-3') oxime (acetamidine) ((acac) Ir(btp) ₂ ), ginseng (2-phenylpyridine) ruthenium (Ir(ppy) ₃ ), ruthenium (4,6-difluorophenylpyridine-N, C2), Firpic, respectively Used as red, green and blue materials.

The luminescent material can be used in combination with a host and a dopant to improve color purity, luminescence efficiency, and stability. When a dopant/host material system is used as the luminescent material, the selection is quite important because the host material greatly affects the efficiency and performance of the EL device. Currently, 4,4'-N,N'-dicarbazole-biphenyl (CBP) is the most widely known phosphorescent host material. Recently, (Japan) Pioneer et al. used bathocopper (BCP) and bismuth (2-methyl-8-hydroxyquinoline) (4-phenylphenol) aluminum (III) (BAlq) as the main material. A high-performance organic EL device has been developed (which is known as a hole blocking layer material).

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, degradation may occur during high temperature deposition under vacuum. (2) The power efficiency of the organic EL device is obtained by [(Π/voltage) x current efficiency], and the power efficiency is inversely proportional to the voltage. Although an organic EL device including a phosphorescent host material provides higher current efficiency (cd/A) than a device including a phosphor material, a significantly high driving voltage is required. Thus, it is not useful in terms of power efficiency (lumens (lm) / watt (W)). (3) Again, the operating life of the organic EL device is short, so it is still necessary to improve the luminous efficiency.

Meanwhile, copper phthalocyanine (CuPc), 4,4'-贰[N-(1-naphthyl)-N-phenylamino]biphenyl (NPB), N,N'-diphenyl-N, N'-贰(3-methylphenyl)-(1,1'-biphenyl)-4,4'-diamine (TPD), 4,4',4"-para (3-methylphenyl) Phenylamino)triphenylamine (MTDATA) or the like is used as a hole injection and transport material.

However, organic EL devices using such materials are problematic in terms of quantum efficiency and service life. The reason is that when the organic EL device is driven at a high current, thermal stress occurs between the anode and the hole injection layer. Thermal stress significantly reduces the life of the device. Again, the organic material used in the hole injection layer has extremely high hole mobility, which may break the hole-electron charge balance and may reduce the quantum yield (cd/A).

Therefore, in order to realize the excellent characteristics of the organic EL device, it is necessary to appropriately select a material constituting the organic layer in the device, particularly a host or a dopant constituting the luminescent material. Korean Patent Application No. 1219492 discloses an organic electric system comprising a special structure of a specific fused heterocyclic moiety Field luminescent compound. However, by using an electric field illuminating device experiment comprising a compound disclosed in the aforementioned references, the inventors have found that a device comprising the compound of the present invention is more effective.

By developing an organic electroluminescent compound capable of providing better EL device performance than the compounds disclosed in the aforementioned references, the inventors have found that the compounds of the present invention not only provide a device with high luminous efficiency and excellent performance, but also are caused by low molecular weight. The reduction in evaporation temperature and the improvement of the synthesis method can also improve the thermal stability.

A first object of the present invention is to provide an organic electroluminescent compound having high luminous efficiency, and a second object is to provide an organic electroluminescent EL device comprising the compound having a long operating life and improved power and current efficiency.

The inventors have found that the aforementioned object can be achieved by the compound represented by the following formula (1):

Wherein L ₁ represents a single bond, a substituted or unsubstituted (3 to 30 membered) heteroaryl group, a substituted or unsubstituted (C6-C30) extended aryl group, or a substituted or unsubstituted group. (C1-C30)alkylene; X ₁ represents NR ₅ , CR ₆ R ₇ , O, or S, but with the proviso that when Y ₁ represents N, X _{1 is} not S; X ₂ to X ₅ are each independently Represents CR ₈ or N; Y ₁ and Y ₂ each independently represent CR ₉ or N; R ₁ to R ₄ each independently represent hydrogen, deuterium, halogen, cyano, carboxyl, nitro, hydroxy, substituted or unsubstituted Substituted (C1-C30)alkyl, substituted or unsubstituted (C3-C30)cycloalkyl, substituted or unsubstituted (C3-C30)cycloalkenyl, substituted or unsubstituted ( 3 to 7 members) heterocycloalkyl, substituted or unsubstituted (C6-C30) aryl, substituted or unsubstituted (3 to 30 membered) heteroaryl, -NR ₁₀ R ₁₁ , or - SiR ₁₂ R ₁₃ R ₁₄ ; R ₁ , R ₂ , and R ₃ may be linked to one or more adjacent substituents to form a monocyclic or polycyclic (C3-C30) cycloaliphatic or aromatic ring; R ₅ to R ₉ each independently represent hydrogen, deuterium, halogen, substituted or unsubstituted (C1-C30) alkyl, substituted or unsubstituted Substituted (C6-C30) aryl, substituted or unsubstituted (3 to 30 membered) heteroaryl, substituted or unsubstituted (C3-C30) cycloalkyl, substituted or unsubstituted (3 to 7 membered) heterocycloalkyl, substituted or unsubstituted (C6-C30) aryl (C1-C30) alkyl, -NR ₁₀ R ₁₁ , -SiR ₁₂ R ₁₃ R ₁₄ , cyano , nitro, or hydroxy; R ₁₀ and R ₁₁ each independently represent hydrogen, deuterium, halogen, substituted or unsubstituted (C1-C30) alkyl, substituted or unsubstituted (C6-C30) aryl a substituted or unsubstituted (3 to 30 membered) heteroaryl group; R ₁₂ to R ₁₄ each independently represent hydrogen, deuterium, halogen, substituted or unsubstituted (C1-C30) alkyl, Substituted or unsubstituted (C6-C30) aryl, substituted or unsubstituted (3 to 30 membered) heteroaryl, substituted or unsubstituted (3 to 7 membered) heterocycloalkyl, Or substituted or unsubstituted (C3-C30)cycloalkyl; or linked to one or more adjacent substituents to form a substituted or unsubstituted monocyclic or polycyclic system (C3-C30) a cycloaliphatic ring or an aromatic ring; the carbon atom of the cycloaliphatic ring or the aromatic ring may be selected from nitrogen, oxygen and At least one hetero atom is substituted; the (extended) heteroaryl group and the heterocycloalkyl group each independently contain at least one selected from the group consisting of B, N, O, S, P(=O), Si, and P a hetero atom; and a, b, c, and d each independently represent an integer from 1 to 4; where a, b, c, or d is an integer greater than 2 or 2, each R ₁ , each R ₂ Each R ₃ and each R ₄ may be the same or different.

The organic electroluminescent compound according to the present invention has characteristics of high luminous efficiency and good material life. An organic electric field illuminating device comprising the compound provides long operating life and excellent current and power efficiency.

Hereinafter, the present invention will be described in detail. However, the following detailed description is intended to be illustrative of the invention and is not intended to limit the scope of the invention this.

The present invention relates to an organic electroluminescent compound of the formula (1), an organic electroluminescent material comprising the compound, and an organic electric field light-emitting device comprising the same.

Here, "(C1-C30)(alkyl)alkyl" means a linear or branched alkyl group having 1 to 30 carbon atoms, wherein the number of carbon atoms is preferably from 1 to 20, more preferably from 1 to 10, including methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, etc.; "(C2-C30)alkenyl" means 2 to 30 carbon atoms Linear or branched alkenyl group, wherein the number of carbon atoms is preferably from 2 to 20, more preferably from 2 to 10, including vinyl, 1-propenyl, 2-propenyl, 1-butenyl, 2-butene a group, 3-butenyl group, 2-methylbut-2-enyl group, etc.; "(C2-C30) alkynyl group" means a linear or branched alkynyl group having 2 to 30 carbon atoms, wherein the number of carbon atoms is higher Preferably 2 to 20, more preferably 2 to 10, including ethynyl, 1-propynyl, 2-propynyl, 1-butynyl, 2-butynyl, 3-butynyl, 1- Methylpent-2-ynyl and the like; "(C3-C30)cycloalkyl" means a monocyclic or polycyclic hydrocarbon group having 3 to 30 carbon atoms, wherein the number of carbon atoms is preferably from 3 to 20. More preferably 3 to 7, including cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, etc.; "(3 to 7 membered) heterocycloalkyl" is 3 to 7 ring bones The cycloalkyl group of the atom, preferably 5 to 7, includes at least one hetero atom selected from the group consisting of B, N, O, S, P(=O), Si, and P, preferably O, S and N, including tetrahydrofuran, pyrrolidine, tetrahydrothiophene, tetrahydropyran, etc.; "(C6-C30) (extended) aryl" is a monocyclic ring derived from an aromatic hydrocarbon having 6 to 30 carbon atoms or a fused ring wherein the number of carbon atoms is preferably from 6 to 20, more preferably from 6 to 15, including phenyl, biphenyl, terphenyl, naphthyl, anthracenyl, phenanthryl, anthracenyl, anthracenyl Base, (co-triphenyl, fluorenyl, tetracenyl, fluorenyl, fluorenyl, naphthacenyl, propadiene, etc.; "(3 to 30 members) (extension) "Heteroaryl" is an aryl group having 3 to 30 ring skeleton atoms, preferably 3 to 20, more preferably 3 to 15, including B, N, O, S, P(=O) At least one of Si, Si and P is preferably 1 to 4 hetero atoms; a monocyclic ring or a fused ring condensed with at least one benzene ring; may be partially saturated; may be at least one heteroaryl Or an aryl group linked to a heteroaryl group through a single bond; including a monocyclic ring type heteroaryl package Furyl, thienyl, pyrrolyl, imidazolyl, pyrazolyl, thiazolyl, thiadiazolyl, isothiazolyl, iso Azolyl, Azolyl, Diazolyl, three Base, four Base, triazolyl, tetrazolyl, furazolyl, pyridyl, pyridyl Base, pyrimidinyl, oxime And fused cycloheteroaryl include benzofuranyl, benzothienyl, isobenzofuranyl, dibenzofuranyl, dibenzothiophenyl, benzimidazolyl, benzothiazolyl, Benzoisothiazolyl, benzoid Azolyl, benzo Azolyl, isodecyl, fluorenyl, oxazolyl, benzothiadiazolyl, quinolyl, isoquinolyl, porphyrinyl, quinazolinyl, quin Orolinyl, carbazolyl, brown Peptidyl, benzodiyl 呃基等. Further, "halogen" includes F, Cl, Br, and I.

Herein, "substituted" in the phrase "substituted or unsubstituted" means that a hydrogen atom in a certain functional group is replaced by another atom or a group, that is, a substituent. Substituted (C1-C30) (extended) alkyl group, substituted (C3-C30) cycloalkyl group, substituted (C3-C30) in L _{1 of} formula (1), and R ₁ to R ₁₄ a cycloalkenyl group, a substituted (3 to 7 membered) heterocycloalkyl group, a substituted (C6-C30) (extended) aryl group, a substituted (3 to 30 membered) (extended) heteroaryl group, Substituting (C6-C30) aryl (C1-C30) alkyl, and substituted monocyclic or polycyclic (C3-C30) cycloaliphatic or aromatic rings, each independently Is at least one selected from the group consisting of hydrazine, halogen, cyano, carboxyl, nitro, hydroxy, (C1-C30) alkyl, halo (C1-C30) alkyl, (C2- C30) alkenyl, (C2-C30)alkynyl, (C1-C30)alkoxy, (C1-C30)alkylthio, (C3-C30)cycloalkyl, (C3-C30)cycloalkenyl, (3 to 7 members) heterocycloalkyl, (C6-C30) aryloxy, (C6-C30) arylthio, unsubstituted or substituted by (C6-C30) aryl (3 to 30 members) a heteroaryl group, an unsubstituted or substituted (3 to 30 membered) heteroaryl group (C6-C30) aryl group, a tri(C1-C30)alkyl fluorenyl group, a tris(C6-C30) aryl fluorenyl group, Di(C1-C30)alkyl (C6-C30) aryl fluorenyl, (C1-C30)alkyl bis(C6-C30) aryl fluorenyl, amine group, single -or di-(C1-C30)alkylamino, mono- or di-(C6-C30)arylamino, (C1-C30)alkyl(C6-C30)arylamine, (C1-C30 An alkylcarbonyl group, (C1-C30) alkoxycarbonyl group, (C6-C30) arylcarbonyl group, di(C6-C30) aryl boron group, di(C1-C30)alkyl boron group, (C1-C30) An alkyl (C6-C30) aryl boron group, a (C6-C30) aryl (C1-C30) alkyl group, and a (C1-C30) alkyl (C6-C30) aryl group.

The compound represented by the formula (1) can be represented by the formula (2):

Wherein Y ₂ is CR ₉ ; and L ₁ , X ₁ to X ₅ , R ₁ to R ₄ , a, b, c, and d are as defined in the formula (1).

The compound represented by the formula (1) can be represented by the formula (3):

Wherein Y ₁ is CR ₉ ; and L ₁ , X ₁ to X ₅ , R ₁ to R ₄ , a, b, c, and d are as defined in the formula (1).

The compound represented by the formula (1) can be represented by the formula (4):

Wherein Y ₁ and Y ₂ are CR ₉ ; X ₂ to X ₄ are CR ₈ ; and L ₁ , X ₁ , R ₁ to R ₄ , a, b, c, and d are as defined in the formula (1).

In the above formula (1) to formula (4), preferably, L ₁ represents a single bond, or a substituted or unsubstituted (C6-C30) extended aryl group; and R ₁ to R ₄ each independently represent hydrogen, Cyano, substituted or unsubstituted (C1-C30) alkyl, substituted or unsubstituted (C6-C30) aryl, substituted or unsubstituted (3 to 30 membered) heteroaryl, Or -NR ₁₀ R ₁₁ ; R ₅ to R ₉ each independently represent hydrogen, cyano, substituted or unsubstituted (C1-C30) alkyl, or substituted or unsubstituted (C6-C30) aryl And R ₁₀ and R ₁₁ each independently represent a substituted or unsubstituted (C6-C30) aryl group.

The compound represented by the formula (1) includes the following compounds, but is not limited thereto:

The organic electroluminescent compound of the present invention can be prepared by a synthetic method known to those skilled in the art. For example, such compounds can be prepared according to the following reaction scheme.

[Reaction Scheme 1]

Wherein L ₁ , X ₁ to X ₅ , Y ₁ , Y ₂ , R ₁ to R ₄ , a, b, c, and d are as defined in the above formula (1).

Another embodiment of the present invention provides an organic electroluminescent material comprising the organic electroluminescent compound of the formula (1), and an organic electric field emitting device comprising the material.

The foregoing materials may individually comprise an organic electroluminescent compound according to the invention, or may further comprise conventional materials commonly used in organic electroluminescent materials.

The organic electric field light-emitting device includes a first electrode, a second electrode, and at least one organic layer interposed between the first electrode and the second electrode. The organic layer may comprise at least one compound of formula (1).

One of the first electrode and the second electrode is an anode, and the other is a cathode. The organic layer comprises a light-emitting layer, and may further comprise at least one layer selected from the group consisting of: a hole injection layer, a hole transport layer, an electron transport layer, an electron injection layer, an intermediate layer, and a hole sealing layer And electronic blocking layer.

The organic electroluminescent compound of the formula (1) may be contained in the light-emitting layer as a host material. Preferably, the luminescent layer may further comprise one or more dopants, and if desired, the luminescent layer may further comprise the formula (1) Another compound other than the organic electroluminescent compound is used as the second host material.

Another embodiment of the present invention provides a material for fabricating an organic electric field illuminating device. The material comprises a first host material and a second host material, and the first host material comprises the organic electroluminescent compound of the invention. Here, the ratio of the first host material to the second host material is in the range of 1:99 to 99:1.

The second host material can be obtained from any of the known phosphorescent bodies. It is preferred to use a host selected from the group consisting of the following formulas (5) to (9).

H-(Cz-L ₄ ) _h -M----------(5)

H-(Cz) _i -L ₄ -M----------(6)

Where Cz represents the following structure:

X represents O or S; R ₂₁ to R ₂₄ each independently represent hydrogen, deuterium, halogen, substituted or unsubstituted (C1-C30) alkyl, substituted or unsubstituted (C6-C30) aryl Substituted or unsubstituted (5 to 30 membered) heteroaryl, or SiR ₂₅ R ₂₆ R ₂₇ ; or may be linked to one or more adjacent substituents to form (5 to 30 members) a single ring system or a polycyclic cycloaliphatic ring or an aromatic ring, the carbon atom of which may be substituted with at least one hetero atom selected from the group consisting of nitrogen, oxygen and sulfur; R ₂₅ to R ₂₇ each independently represent substituted or unsubstituted (C1) -C30)alkyl, or substituted or unsubstituted (C6-C30) aryl; L ₄ represents a single bond, substituted or unsubstituted (C6-C30) extended aryl, or substituted or unsubstituted Substituted (5 to 30 membered) heteroaryl; M represents substituted or unsubstituted (C6-C30) aryl, or substituted or unsubstituted (5 to 30 membered) heteroaryl; Y ₃ To Y ₄ each independently represents O, S, N(R ₃₁ ), or C(R ₃₂ )(R ₃₃ ), and the restriction condition is that Y ₃ to Y _{4 are} not present at the same time; R ₃₁ to R ₃₃ each independently represent a Substituted or unsubstituted (C1-C30) alkyl, substituted or unsubstituted (C6-C30) aryl, Or a substituted or unsubstituted (5 to 30 membered) heteroaryl; or may be linked to one or more adjacent substituents to form a (5 to 30 membered) monocyclic or polycyclic cycloaliphatic ring or An aromatic ring, the carbon atom of which may be substituted with at least one hetero atom selected from the group consisting of nitrogen, oxygen and sulfur; and R ₃₂ and R ₃₃ may be the same or different; h and i each independently represent an integer from 1 to 3; j, k, l, and m each independently represent an integer of 0 to 4; and when h, i, j, k, l, or m is an integer greater than 2 or 2, each (Cz-L ₄ ), each ( Cz), each R ₂₁ , each R ₂₂ , each R ₂₃ or each R ₂₄ may be the same or different.

More specifically, the preferred embodiment of the second host material is as follows:

[where TPS represents triphenylsulfonyl].

The dopant is preferably at least one phosphorescent dopant. The dopant material applied to the organic electric field light-emitting device according to the present invention is not particularly limited, but may be preferably selected from the group consisting of metallization complex compounds of ruthenium, osmium, copper and platinum, more preferably selected from ruthenium. , ortho-metalled, ortho-metalled, and even more preferably ortho-metallated ruthenium complexes.

The dopant contained in the organic electric field light-emitting device according to the present invention may be selected from the compounds represented by the following formulas (10) to (12).

Wherein L is selected from the following structures:

R ₁₀₀ represents hydrogen, substituted or unsubstituted (C1-C30) alkyl, or substituted or unsubstituted (C3-C30) cycloalkyl; each of R ₁₀₁ to R ₁₀₉ and R ₁₁₁ to R ₁₂₃ Independently representing hydrogen, deuterium, halogen, unsubstituted or halogen-substituted (C1-C30) alkyl, substituted or unsubstituted (C3-C30) cycloalkyl, cyano, or substituted or unsubstituted Substituting (C1-C30) alkoxy; and adjacent substituents of R ₁₂₀ to R ₁₂₃ may be linked to each other to form a fused ring, such as quinoline; R ₁₂₄ to R ₁₂₇ each independently represent hydrogen, deuterium, halogen, a substituted or unsubstituted (C1-C30) alkyl group, or a substituted or unsubstituted (C6-C30) aryl group; when R ₁₂₄ to R ₁₂₇ are an aryl group, adjacent substituents may be linked to each other Forming a fused ring, such as hydrazine; R ₂₀₁ to R ₂₁₁ each independently represent hydrogen, deuterium, halogen, unsubstituted or halogen-substituted (C1-C30) alkyl, substituted or unsubstituted (C3-C30 a cycloalkyl group, or a substituted or unsubstituted (C6-C30) aryl group; f and g each independently represent an integer of 1 to 3; when f or g is an integer of 2 or more, R ₁₀₀ each May be the same or different; and n means 1 to 3 Number.

More specifically, the phosphorescent dopant materials include the following:

In another embodiment of the invention, a composition for an organic electric field illumination device is provided. The composition comprises a compound according to the invention as a host or a hole transporting material.

Furthermore, the organic electric field light-emitting device according to the present invention comprises a first electrode; a second electrode; and at least one organic layer interposed between the first electrode and the second electrode. The organic layer comprises a light-emitting layer, and the light-emitting layer may comprise a composition for the organic electric field light-emitting device according to the invention.

In addition to the organic electroluminescent compound represented by the formula (1), the organic electroluminescent device according to the present invention may further comprise a compound selected from the group consisting of an arylamine-based compound and a styrylarylamine. At least one compound of the group consisting of compounds.

In the organic electric field light-emitting device according to the present invention, the organic layer may further comprise a Group 1 metal selected from the periodic table, a Group 2 metal, a fourth periodic transition metal, a fifth periodic transition metal, a lanthanoid element, And at least one metal selected from the group consisting of organometallics of d-transition elements, or at least one miscible compound comprising the metal.

Furthermore, the organic electric field illuminating device according to the present invention can emit white light by further comprising at least one of the following luminescent layers in addition to the organic electroluminescent compound according to the present invention, the luminescent layer comprising blue electric field luminescence known in the art. A compound, a red electric field luminescent compound or a green electric field luminescent compound. Also, a yellow or orange light emitting layer may be included in the device if desired.

According to the present invention, at least one layer (hereinafter referred to as "surface layer") selected from the group consisting of a chalcogenide layer, a metal halide layer and a metal oxide layer is preferably placed in one or both of the electrodes On the surface. More specifically, the chalcogenide or aluminum chalcogenide (including oxide) layer is preferably disposed on the anode surface of the electric field luminescent medium layer, and the metal halide layer and the metal oxide layer are preferably disposed in the electric field illuminating medium. On the cathode surface of the layer. Such a surface layer provides operational stability to an organic electric field illuminating device. Preferably, the chalcogenide comprises SiO _x (1 X 2), AlO _x (1 X 1.5), SiON, SiAlON, etc.; the metal halide includes LiF, MgF ₂ , CaF ₂ , rare earth metal fluoride, etc.; and the metal oxide includes Cs ₂ O, Li ₂ O, MgO, SrO, BaO, CaO, etc. .

In the organic electric field light-emitting device according to the present invention, preferably, 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 is disposed in at least one of the electrode pairs. On the surface. In this case, the electron transporting compound is reduced to an anion, thereby making it easier to inject electrons from the mixed region and transport electrons to the electric field illuminating medium. Further, the hole transporting compound is oxidized to a cation, and thus it becomes easier to inject a hole and a transmission hole from the mixed region to the electric field illuminating medium. Preferably, the oxidizing dopant comprises various Lewis acids and acceptor compounds; and the reducing dopant comprises an alkali metal, an alkali metal compound, an alkaline earth metal, a rare earth metal, and mixtures thereof. The reducing dopant layer can be used as a charge generating layer to prepare an electric field illuminating device having two or more layers of an electroluminescent layer and emitting white light.

In order to form the layers of the organic electric field light-emitting device according to the present invention, a dry film forming method such as vacuum evaporation, sputtering, or the like may be used. The plasma plating method and the ion plating method, or a wet film forming method such as a spin coating method, a dip coating method, and a flow coating method may be used.

When a wet film formation method is used, the material forming the layers is dissolved or dispersed in any suitable solvent such as ethanol, chloroform, tetrahydrofuran, A film can be formed in an alkane or the like. The solvent may be any solvent in which the materials forming the respective layers can be dissolved or dispersed, and which is not problematic in film forming ability.

Hereinafter, the organic electroluminescent compound, the method of producing the compound, and the luminescent properties of the device will be explained in detail with reference to the following examples.

Example 1: Preparation of Compound H-1

Preparation of Compound 2-1

Add 1,4-dibromonaphthalene (50 g (g), 174.8 mmol (mmol)), pinacol diborane (98 g, 391.6 mmol), bismuth (triphenyl) Palladium (II) palladium (II) chloride [PdCl ₂ (PPh ₃ ) ₂ ] (12 g, 17.8 mmol), potassium acetate (KOAc) (76 g, 769.1 mmol), and tetrahydrofuran (THF) 1 After liter (L) into the flask, the mixture was stirred at reflux for 5 hours. After the reaction was completed, the organic layer was extracted with ethyl acetate (EA), and magnesium sulfate was used to remove residual water. The resulting solid was dried and purified using column chromatography to afford compound 2-1 (60 g, 94%).

Preparation of Compound 2-2

Add compound 2-1 (60 g, 157.8 mmol), 1-bromo-2-nitrobenzene (96 g, 473.4 mmol), hydrazine (triphenylphosphine) palladium (0) [Pd (PPh) ₃ ) ₄ ] (18.3 g, 15.7 mmol), 2M sodium carbonate (Na ₂ CO ₃ ) 240 ml, ethanol (EtOH) 240 ml, and toluene (Tol) 500 ml into the flask, the mixture was at 120 ° C Stirring was carried out for 5 hours under reflux. After the reaction was completed, the organic layer was extracted with ethyl acetate (EA), and magnesium sulfate was used to remove residual water. The resulting solid was dried and purified using column chromatography to afford compound 2-2 (50 g, 85%).

Preparation of Compound 2-3

After adding compound 2-2 (43 g, 116.1 mmol), triphenylphosphine (PPh ₃ ) (61 g, 232.2 mmol), and dichlorobenzene (DCB) 600 ml into the flask, the mixture The mixture was stirred under reflux at 150 ° C for 5 hours. After completion of the reaction, the mixture was distilled and pulverized with methanol (MeOH) to give Compound 2-3 (22 g, 56%).

Preparation of compound 2-4

Add compound 2-3 (22 g, 65.0 mmol), iodobenzene (11 ml (mL), 97.5 mmol), CuI (6.2 g, 32.5 mmol), K ₃ PO ₄ (42 g, After 195 mmol, Ethyldiamine (EDA) (9 ml, 130 mmol), and 300 ml of toluene were placed in the flask, the mixture was stirred under reflux at 120 ° C for 5 hours. After the reaction was completed, the organic layer was extracted with ethyl acetate (EA), and magnesium sulfate was used to remove residual water. The resulting solid was dried and purified using column chromatography to afford compound 2-4 (18 g, 67%).

Preparation of compound 2-5

After adding compound 2-4 (18 g, 43.4 mmol), PPh ₃ (25 g, 108.5 mmol), and dichlorobenzene (DCB) 220 ml into the flask, the mixture was stirred at 150 ° C under reflux. hour. After completion of the reaction, the mixture was distilled and pulverized with methanol to obtain compound 2-5 (11 g, 70%).

Preparation of Compound H-1

After compound 2-5 (4 g, 10.47 mmol) and compound 1-9 (4.2 g, 15.7 mmol) were dissolved in 50 ml of dimethylformamide (DMF), NaH (0.6 g, 15.71 m) Mohr, 60% in mineral oil) was added to the mixture. The mixture was then stirred at room temperature for 12 hours, and methanol and distilled water were added thereto. The obtained solid was filtered under reduced pressure, and then purified using column chromatography to afford Compound H-1 (4.2 g, 65%).

Example 2: Preparation of Compound H-62

Preparation of Compound 3-1

After adding compound 2-2 (55 g, 0.148 mol), PPh ₃ (78 g, 0.297 mol (mol)), and dichlorobenzene (DCB) 1100 ml into the flask, the reaction mixture was heated to 190 ° C. Stir for 5 hours. After completion of the reaction, dichlorobenzene (DCB) was removed using a distiller, the mixture was washed with distilled water, extracted with ethyl acetate, the organic layer was dried over magnesium sulfate (MgSO ₄ ), and solvent was removed using a rotary evaporator. Thereafter, the obtained solid was purified using column chromatography to obtain Compound 3-1 (35 g, 78%).

Preparation of Compound 3-2

Add compound 3-1 (9.4 g, 0.031 mol), iodobenzene (6.3 g, 0.031 mol), copper iodide (CuI) (2.95 g, 0.015 mol), potassium carbonate (K ₂ CO ₃ ) ( After 4.3 g, 0.031 mol, and ethyl diamine (EDA) (2 mL, 0.031 mol) were added to the flask, the reaction mixture was heated to 120 ° C and stirred for 5 hours. After completion of the reaction, the mixture was washed with distilled water, extracted with ethyl acetate, the organic layer was dried over magnesium sulfate, and the solvent was removed using a rotary evaporator. Thereafter, the obtained solid was purified using column chromatography to obtain Compound 3-2 (11 g, 93%).

Preparation of Compound 3-3

Add compound 3-2 (11 g, 0.030 mol), 1-bromo-4-iodobenzene (17 g, 0.060 mol), copper (Cu) (5.7 g, 0.090 mol), potassium carbonate (21 g) After 0.150 moles, 18-crown-6 (1.6 g, 0.006 moles), and 115 ml of dichlorobenzene (DCB) into the flask, the reaction mixture was heated to 190 ° C and stirred for 12 hours. Then, dichlorobenzene was removed using a distiller, the mixture was washed with distilled water, extracted with ethyl acetate, the organic layer was dried over magnesium sulfate, and the solvent was removed using a rotary evaporator. Thereafter, the obtained solid was purified using column chromatography to obtain Compound 3-3 (14 g, 87%).

Preparation of compound 3-4

After adding compound 3-3 (14 g, 0.026 mol) to a flask under nitrogen atmosphere, 200 ml of THF was added, and the mixture was stirred at -78 ° C for 20 minutes. Thereafter, n-butyllithium (n-BuLi) (2.5 M) (12.5 ml, 0.031 mol) was slowly added to the flask, and the mixture was stirred at -78 ° C for 40 minutes. Then 2-isopropoxy-4,4,5,5-tetramethyl-1,3,2-di boron (8 ml, 0.039 mol) was added to the flask, and the mixture was stirred at room temperature for 12 hours. After completion of the reaction, the mixture was washed with distilled water, extracted with ethyl acetate, the organic layer was dried over magnesium sulfate, and the solvent was removed using a rotary evaporator. Thereafter, the obtained solid was purified using column chromatography to obtain compound 3-4 (11 g, 73%).

Preparation of Compound H-62

Add compound 3-4 (2 g, 0.003 mol), compound 1-9 (784 mg, 0.003 mol), Pd(PPh ₃ ) ₄ (230 mg (mg), 0.23 mmol), potassium carbonate ( After 2M, 5 ml), 5 ml of ethanol, and 10 ml of toluene were placed in a flask, the reaction mixture was heated to 120 ° C and stirred for 7 hours. After completion of the reaction, the mixture was washed with distilled water, extracted with ethyl acetate, the organic layer was dried over magnesium sulfate, and the solvent was removed using a rotary evaporator. Thereafter, the obtained solid was purified using column chromatography to obtain Compound H-62 (1.5 g, 71%).

Example 3: Preparation of Compound H-13

Compound 4-1 (14 g, 0.043 mol), compound 4-2 (18.4 g, 0.065 mol), copper iodide (4.1 g, 0.021 mol), ethyl diamine (2.9 ml, 0.043) were added. Mohr), Cs ₂ CO ₃ (27.5 g, 0.129 mol), and 400 ml of toluene were placed in the flask, and the mixture was stirred at 120 ° C for 12 hours. After completion of the reaction, the mixture was washed with distilled water, extracted with ethyl acetate, the organic layer was dried over magnesium sulfate, and the solvent was removed using a rotary evaporator. Thereafter, the obtained solid was purified using column chromatography to obtain Compound H-13 (8.5 g, 43%).

Example 4: Preparation of Compound H-90

Preparation of compound 5-2

Compound 4-1 (14 g, 0.043 mol), compound 5-1 (18.4 g, 0.065 mol), copper iodide (4.1 g, 0.021 mol), ethyl diamine (2.9 ml, 0.043) were added. Mol), cesium carbonate (27.5 g, 0.129 mol), and 400 ml of toluene were placed in the flask, and the mixture was stirred at 1.20 ° C for 12 hours. After completion of the reaction, the mixture was washed with distilled water, extracted with ethyl acetate, the organic layer was dried over magnesium sulfate, and the solvent was removed using a rotary evaporator. Thereafter, the obtained solid was purified using column chromatography to obtain Compound 5-2 (8.5 g, 43%).

Preparation of compound 5-3

Add compound 5-2 (7.3 g, 0.015 mol), 4,4,4',4',5,5,5',5'-octamethyl-2,2'-linked-(1,3 , 2-two boron ) (5.9 g, 0.023 mol), potassium acetate (3.8 g, 0.038 mol), PdCl ₂ (PPh ₃ ) ₂ (561 mg, 0.008 mol), and 1,4-two After 70 ml of the alkane was introduced into the flask, the mixture was heated to 150 ° C and stirred for 5 hours. After completion of the reaction, the mixture was washed with distilled water, extracted with ethyl acetate, the organic layer was dried over magnesium sulfate, and the solvent was removed using a rotary evaporator. Thereafter, the obtained solid was purified by column chromatography to obtain Compound 5-3 (5.0 g, 68%).

Preparation of Compound H-90

Add compound 5.3 (2.5 g, 0.0048 mol), compound 4.2 (1.0 g, 0.0044 mol), Pd(PPh ₃ ) ₄ (230 mg, 0.0005 mmol), potassium carbonate (2M, 6.3 mL), ethanol After 6.3 ml, and 13 ml of toluene were placed in the flask, the reaction mixture was heated to 120 ° C and stirred for 7 hours. After completion of the reaction, the mixture was washed with distilled water, extracted with ethyl acetate, the organic layer was dried over magnesium sulfate, and the solvent was removed using a rotary evaporator. Thereafter, the obtained solid was purified using column chromatography to obtain Compound H-90 (2.1 g, 84%).

Example 5: Preparation of Compound H-9

Preparation of compound 6-2

Compound 6-1 (15 g, 94.23 mmol), 2-chloroiodobenzene (12.6 mL, 103.65 mmol), palladium(II) acetate [Pd(OAc) ₂ ] (0.84 g, 3.76) were dissolved in the flask. Millol), 50% tributylphosphine (3.6 ml, 7.53 mmol), and sodium butoxide (22.6 g, 235.57 mmol) in 480 ml of toluene, the mixture was refluxed at 120 ° C. 4 hours. After completion of the reaction, the mixture was extracted with dichloromethane/purified water and then purified by column chromatography to afford compound 6-2 (10.4 g, 41%).

Preparation of Compound 6-3

Dissolved compound 6-2 (9.4 g, 34.93 mmol), 2-chloroiodobenzene (4.25 ml, 34.93 mmol), Cu ₂ O (1.5 g, 10.48 mmol), picolinic acid (2.6 g, 20.96) After mM, and cesium carbonate (23 g, 69.87 mmol) in 170 ml of acetonitrile, the mixture was stirred under reflux at 100 ° C for 12 hours. After completion of the reaction, the mixture was extracted with dichloromethane and separated by column chromatography to afford compound 6-3 (4 g, 30%).

Preparation of Compound 6-4

Compound 6-3 (4 g, 10.55 mmol), Pd(OAc) ₂ (0.23 g, 1.055 mmol), ligand (0.77 g, 2.11 mmol), and potassium carbonate (13.7 g, 42.2) After 50 ml of N-methylpyrrolidone, the mixture was stirred under reflux at 220 ° C for 3 hours. After completion of the reaction, the mixture was extracted with dichloromethane/purified water and then purified by column chromatography to afford compound 6-4 (2.5 g, 78%).

Preparation of Compound H-9

After dissolving compound 6-4 (4 g, 13.01 mmol) and compound 4-2 (3.1 g, 13.01 mmol) in 50 ml of dimethylformamide (DMF), NaH (1.56 g, 39.03 m) was added. Mohr, 60% in mineral oil) to the mixture. The mixture was then stirred at room temperature for 12 hours, and methanol and distilled water were added thereto. The obtained solid was filtered under reduced pressure and purified by column chromatography to yield Compound H-9 (1.7 g, 25.5%).

Device Example 1: Manufacture of an OLED device using the organic electroluminescent compound according to the present invention

OLED devices are fabricated using organic electroluminescent compounds in accordance with the present invention. Transparent electrode indium tin oxide (ITO) film (15 ohm/square unit (Ω/sq)) on a glass substrate for an organic light-emitting diode (OLED) device (Samsung Corning, Korea) It is washed with trichloroethylene, acetone, ethanol, and distilled water, and then stored in isopropyl alcohol. Then, 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)indole (N ¹ -(naphthalen-1-yl)-N ⁴ ,N ⁴ -diphenylbenzene- 1,4-Diamine) is introduced into a chamber of the vacuum vapor deposition apparatus, and then the pressure in the chamber of the apparatus is controlled at 10 ^-6 Torr. Thereafter, a current was applied to the cell to evaporate the material introduced as above, thereby forming a hole injection layer having a thickness of 60 nm on the ITO substrate. Then, N,N'-bis(4-biphenyl)-N,N'-bis(4-biphenyl)-4,4'-diaminobiphenyl is introduced into another chamber of the vacuum vapor deposition apparatus. And by applying an electric current to the chamber to be evaporated, thereby forming a hole transport layer having a thickness of 20 nm on the hole injection layer. Subsequently, the compound H-90 was introduced into a chamber of the vacuum vapor deposition apparatus as a host material, and the compound D-88 was introduced into another chamber as a dopant. The two materials were evaporated at different rates, and a doping amount of 4 wt% based on the total weight of the host and the dopant was deposited to form a light-emitting layer having a thickness of 30 nm on the hole transport layer. Then, 2-(4-(9,10-di(naphthalen-2-yl)indol-2-yl)phenyl-1-phenyl-1H-benzo[d]imidazole was introduced into a small chamber, and 8 Lithium quinolate is introduced into another chamber. The two materials are evaporated at the same rate and deposited at a respective 50 wt% doping to form an electron having a thickness of 30 nm on the luminescent layer. Then, after depositing lithium hydroxyquinolate having a thickness of 2 nm as an electron injecting layer on the electron transporting layer, an aluminum cathode having a thickness of 150 nm is deposited on the electron by another vacuum vapor deposition apparatus. On the injection layer. Thus, an OLED device was fabricated. All materials used in the fabrication of the OLED device were purified by vacuum sublimation at 10 ^-6 Torr before use.

The manufactured OLED device showed red light with a luminance of 980 candelas per square meter (cd/m ² ) at a driving voltage of 3.5 volts and a current density of 14.6 milliamps per square centimeter (mA/cm ² ). The time period during which the brightness of 5000 nits is reduced to 90% is 100 hours or longer.

Comparative Example 1: Fabrication of an OLED device using a conventional organic electroluminescent compound

The OLED device was fabricated in the same manner as in Device Example 1, but using Compound C-1 As a host, and compound D-88 as a dopant.

The fabricated OLED device showed red light with a brightness of 1000 candelas per square meter at a driving voltage of 3.6 volts (V) and a current density of 15.8 milliamps per square centimeter. The time period during which the brightness of the 5000 nits is reduced to 90% is 80 hours or longer.

By using the organic electroluminescent compound according to the present invention, an organic electric field light-emitting device having excellent luminous efficiency, long driving life, and improved current and power efficiency can be prepared.

Claims (8)

An organic electroluminescent compound which is represented by the following formula (1): Wherein L ₁ represents a single bond, a substituted or unsubstituted (3 to 30 membered) heteroaryl group, a substituted or unsubstituted (C6-C30) extended aryl group, or a substituted or unsubstituted group. (C1-C30)alkylene; X ₁ represents NR ₅ , CR ₆ R ₇ , O, or S, with the proviso that when Y ₁ represents N, X _{1 is} not S; X ₂ to X ₅ are each independently represented CR ₈ or N; Y ₁ and Y ₂ each independently represent CR ₉ or N; R ₁ to R ₄ each independently represent hydrogen, deuterium, halogen, cyano, carboxy, nitro, hydroxy, substituted or unsubstituted (C1-C30)alkyl, substituted or unsubstituted (C3-C30)cycloalkyl, substituted or unsubstituted (C3-C30)cycloalkenyl, substituted or unsubstituted (3 To 7 members) heterocycloalkyl, substituted or unsubstituted (C6-C30) aryl, substituted or unsubstituted (3 to 30 membered) heteroaryl, -NR ₁₀ R ₁₁ , or -SiR ₁₂ R ₁₃ R ₁₄ ; R ₁ , R ₂ , and R ₃ may be bonded to one or more adjacent substituents to form a monocyclic or polycyclic (C3-C30) cycloaliphatic or aromatic ring; ₅ to R ₉ each independently represent hydrogen, deuterium, halogen, substituted or non-substituted (C1-C30) alkyl, substituted or non- Or (C6-C30) aryl, substituted or unsubstituted (3 to 30 membered) heteroaryl, substituted or unsubstituted (C3-C30)cycloalkyl, substituted or unsubstituted (3 to 7 members) heterocycloalkyl, substituted or unsubstituted (C6-C30) aryl (C1-C30) alkyl, -NR ₁₀ R ₁₁ , -SiR ₁₂ R ₁₃ R ₁₄ , cyano, Nitro, or hydroxy; R ₁₀ and R ₁₁ each independently represent hydrogen, deuterium, halogen, substituted or unsubstituted (C1-C30) alkyl, substituted or unsubstituted (C6-C30) aryl Or substituted or unsubstituted (3 to 30 membered) heteroaryl; R ₁₂ to R ₁₄ each independently represent hydrogen, deuterium, halogen, substituted or unsubstituted (C1-C30) alkyl, Substituted or unsubstituted (C6-C30) aryl, substituted or unsubstituted (3 to 30 membered) heteroaryl, substituted or unsubstituted (3 to 7 membered) heterocycloalkyl, or Substituted or unsubstituted (C3-C30)cycloalkyl; or linked to one or more adjacent substituents to form a substituted or unsubstituted monocyclic or polycyclic (C3-C30) ring An aliphatic ring or an aromatic ring; the carbon atom of the cycloaliphatic ring or the aromatic ring may be selected from nitrogen, oxygen and sulfur At least one hetero atom is substituted; the (extended) heteroaryl group and the heterocycloalkyl group each independently contain at least one selected from the group consisting of B, N, O, S, P(=O), Si, and P An atom; and a, b, c, and d each independently represent an integer from 1 to 4; when a, b, c, or d is an integer of 2 or more, each R ₁ , each R ₂ , and each R ₃ And each R ₄ may be the same or different. The organic electroluminescent compound according to claim 1, wherein the compound of the formula (1) is represented by the following formula (2): Wherein Y ₂ is CR ₉ ; and L ₁ , X ₁ to X ₅ , R ₁ to R ₄ , a, b, c, and d are as defined in the first item of the patent application. The organic electroluminescent compound according to claim 1, wherein the compound of the formula (1) is represented by the following formula (3): Wherein Y ₁ is CR ₉ ; and L ₁ , X ₁ to X ₅ , R ₁ to R ₄ , a, b, c, and d are as defined in the first item of the patent application. The organic electroluminescent compound according to claim 1, wherein the compound of the formula (1) is represented by the following formula (4): Wherein Y ₁ and Y ₂ are CR ₉ ; X ₂ to X ₄ are CR ₈ ; and L ₁ , X ₁ , R ₁ to R ₄ , a, b, c, and d are as claimed in claim 1 definition. The organic electroluminescent compound according to claim 1, wherein L ₁ represents a single bond, or a substituted or unsubstituted (C6-C30) extended aryl group; and R ₁ to R ₄ each independently represent hydrogen, Cyano, substituted or unsubstituted (C1-C30) alkyl, substituted or unsubstituted (C6-C30) aryl, substituted or unsubstituted (3 to 30 membered) heteroaryl, Or -NR ₁₀ R ₁₁ ; R ₅ to R ₉ each independently represent hydrogen, cyano, substituted or unsubstituted (C1-C30) alkyl, or substituted or unsubstituted (C6-C30) aryl And R ₁₀ and R ₁₁ each independently represent a substituted or unsubstituted (C6-C30) aryl group. The organic electroluminescent compound according to claim 1, wherein the substituted (C1-C30) (extended) alkyl group in L ₁ and R ₁ to R ₁₄ is substituted (C3-C30 a cycloalkyl group, a substituted (C3-C30) cycloalkenyl group, a substituted (3 to 7 membered) heterocycloalkyl group, a substituted (C6-C30) (extended) aryl group, substituted (3 To 30 members) (extended) heteroaryl, substituted (C6-C30) aryl (C1-C30) alkyl, and substituted monocyclic or polycyclic (C3-C30) cycloaliphatic or The substituents of the aromatic ring are each independently selected from at least one of the group consisting of hydrazine, halogen, cyano, carboxyl, nitro, hydroxy, (C1-C30) alkyl, halo ( C1-C30)alkyl, (C2-C30)alkenyl, (C2-C30)alkynyl, (C1-C30)alkoxy, (C1-C30)alkylthio, (C3-C30)cycloalkyl , (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, unsubstituted or substituted (3 to 30 membered) heteroaryl (C6-C30) aryl, tri(C1-C30)alkyl fluorenyl, three (C6-C30) aryl fluorenyl, di(C1-C30)alkyl (C6-C30) aryl Mercapto, (C1-C30)alkyl di(C6-C30)arylsulfonyl, amine, mono- or di-(C1-C30)alkylamino, mono- or di-(C6-C30) aryl Amino group, (C1-C30)alkyl (C6-C30) arylamino group, (C1-C30) alkylcarbonyl group, (C1-C30) alkoxycarbonyl group, (C6-C30) arylcarbonyl group, (C6-C30) arylboryl, di(C1-C30)alkylboron, (C1-C30)alkyl(C6-C30)arylboryl,(C6-C30)aryl (C1-C30) Alkyl, and (C1-C30)alkyl (C6-C30) aryl. The organic electroluminescent compound according to claim 1, wherein the compound of the formula (1) is selected from the group consisting of the following compounds: An organic electric field light-emitting device comprising the compound according to claim 1 of the patent application.