WO2011136520A1

WO2011136520A1 - Novel organic electroluminescent compounds and organic electroluminescent device using the same

Info

Publication number: WO2011136520A1
Application number: PCT/KR2011/002988
Authority: WO
Inventors: Soo Yong Lee; Young Jun Cho; Hyuck Joo Kwon; Sung Min Kim; Bong Ok Kim
Original assignee: Rohm and Haas Electronic Materials Korea Ltd; Rohm and Haas Electronic Materials LLC
Current assignee: DuPont Specialty Materials Korea Ltd; DuPont Electronic Materials International LLC
Priority date: 2010-04-30
Filing date: 2011-04-25
Publication date: 2011-11-03
Anticipated expiration: 2012-10-30
Also published as: CN102947294A; CN102947294B; KR20110120994A; JP2013525424A; TW201204810A

Abstract

Provided are organic electroluminescent compounds of Chemical Formula I and an organic electroluminescent device using said compounds. When used as a host material of an organic electroluminescent material of an OLED device, the organic electroluminescent compound exhibits good luminous efficiency and excellent life property of the material. Therefore, it may be used to manufacture OLEDs having very good operation life.

Description

NOVEL ORGANIC ELECTROLUMINESCENT COMPOUNDS AND ORGANIC ELECTROLUMINESCENT DEVICE USING THE SAME

The present invention relates to novel organic electroluminescent compounds and an organic electroluminescent device using the same, more particularly, to novel organic electroluminescent compounds used as an electroluminescent material and an organic electroluminescent device using the same.

The most important factor to determine luminous efficiency in an organic light-emitting diode (OLED) is electroluminescent material. Though fluorescent materials have been widely used as electroluminescent material up to the present, development of phosphorescent materials is one of the best ways to improve the luminous efficiency theoretically up to four (4) times, in view of electroluminescent mechanism. Up to now, iridium (III) complexes have been widely known as phosphorescent material, including (acac)Ir(btp)₂, Ir(ppy)₃ and Firpic, as the red, green and blue one, respectively. In particular, a lot of phosphorescent materials have been recently investigated in Japan, Europe and America.

At present, CBP is most widely known as a host material for a phosphorescent material. High-efficiency OLEDs using a hole blocking layer comprising BCP, BAlq, etc. are reported. High-performance OLEDs using BAlq derivatives as a host were reported by Pioneer (Japan) and others.

Although these materials provide good electroluminescence characteristics, they are disadvantageous in that degradation may occur during the high-temperature deposition process in vacuum because of low glass transition temperature and poor thermal stability. Since the power efficiency of an OLED is given by (π / voltage) × current efficiency, the power efficiency is inversely proportional to the voltage. High power efficiency is required to reduce the power consumption of an OLED. Actually, OLEDs using phosphorescent materials provide much better current efficiency (cd/A) than those using fluorescent materials. However, when the existing materials such as BAlq, CBP, etc. are used as a host of the phosphorescent material, there is no significant advantage in power efficiency (lm/W) over the OLEDs using fluorescent materials because of high driving voltage. Further, the OLED devices do not have satisfactory operation life. Therefore, development of more stable, higher-performance host materials is required.

With intensive efforts to overcome the problems of conventional techniques as described above, the present inventors have invented novel electroluminescent compounds which realize organic electroluminescent devices having excellent luminous efficiency and noticeably improved life property.

The object of the present invention is to provide organic electroluminescent compounds having the backbone to provide better luminous efficiency and device life with appropriate color coordinate compared with a conventional dopant material, while overcoming the problems described above. Another object is to provide an organic electroluminescent device having high luminous efficiency and improved life property.

Provided are a novel organic electroluminescent compound represented by following Chemical Formula 1 and an organic electroluminescent device using the same. Since the organic electroluminescent compound according to the present invention exhibits good luminous efficiency and excellent life property compared to the existing host material, it may be used to manufacture OLED devices having very superior operation life.

[Chemical Formula 1]

[Chemical Formula 2]

wherein

the

is the same as defined in Chemical Formula 2,

the X represents -O- or -S-; Y represents -S-, -C(R₁)(R₂)-, -Si(R₃)(R₄)-, -N(R₅)- or a divalent group selected from the group consisting of the following structures;

the Ar₁ through Ar₅ and the R₁ through R₅ independently represent hydrogen, deuterium, (C1-C30)alkyl, halo(C1-C30)alkyl, halogen, cyano, (C3-C30)cycloalkyl, 5- to 7-membered heterocycloalkyl, (C2-C30)alkenyl, (C2-C30)alkynyl, (C6-C30)aryl, (C1-C30)alkoxy, (C6-C30)aryloxy, (C3-C30)heteroaryl, (C6-C30)ar(C1-C30)alkyl, (C6-C30)arylthio, mono or di(C1-C30)alkylamino, mono or di(C6-C30)arylamino, tri(C1-C30)alkylsilyl, di(C1-C30)alkyl(C6-C30)arylsilyl, tri(C6-C30)arylsilyl, nitro or hydroxyl, or each of them may be linked to an adjacent substituent via (C3-C30)alkylene or (C3-C30)alkenylene with or without a fused to form an alicyclic ring, a mono- or polycyclic aromatic ring or a mono- or polycyclic heteroaromatic ring;

each of alkyl, cycloalkyl, heterocycloalkyl, alkenyl, alkynyl, aryl and heteroaryl of the Ar₁ through Ar₅and R₁ through R₅ may be further substituted by one or more substituent(s) selected from the group consisting of deuterium, (C1-C30)alkyl, halo(C1-C30)alkyl, halogen, cyano, (C3-C30)cycloalkyl, 5- to 7-membered heterocycloalkyl, (C2-C30)alkenyl, (C2-C30)alkynyl, (C6-C30)aryl, (C1-C30)alkoxy, (C6-C30)aryloxy, (C3-C30)heteroaryl, (C3-C30)heteroaryl with (C1-C30)alkyl substituent(s), (C3-C30)heteroaryl with (C6-C30)aryl substituent(s), (C6-C30)ar(C1-C30)alkyl, (C6-C30)arylthio, mono or di(C1-C30)alkylamino, mono or di(C6-C30)arylamino, tri(C1-C30)alkylsilyl, di(C1-C30)alkyl(C6-C30)arylsilyl, tri(C6-C30)arylsilyl, nitro or hydroxyl;

the L₁ through L₃ independently represent a chemical bond or a divalent group selected from the group consisting of (C6-C30)arylene, (C3-C30)heteroarylene, di(C1-C30)alkylsilyl or di(C6-C30)arylsilyl group; and

the heterocycloalkyl, heteroaryl and heteroaromatic ring may contain one or more heteroatom(s) selected from B, N, O and S.

In the present invention, "alkyl", "alkoxy" and other substituents containing "alkyl" moiety include both linear and branched species.

In the present invention, "aryl" means an organic radical derived from an aromatic hydrocarbon by the removal of one hydrogen atom, and may include a 4- to 7-membered, particularly 5- or 6-membered, single ring or fused ring, including a plurality of aryl groups having single bond(s) therebetween. Specific examples include phenyl, naphthyl, biphenyl, anthryl, indenyl, fluorenyl, phenanthryl, triphenylenyl, pyrenyl, perylenyl, chrysenyl, naphthacenyl, fluoranthenyl, etc., but are not limited thereto. The naphthyl includes 1-naphthyl and 2-naphthyl. The anthryl includes 1-anthryl, 2-anthryl and 9-anthryl, and the fluorenyl includes 1-fluorenyl, 2-fluorenyl, 3-fluorenyl, 4-fluorenyl and 9-fluorenyl. In the present invention, "heteroaryl" means an aryl group containing 1 to 4 heteroatom(s) selected from B, N, O, and S as aromatic ring backbone atom(s), other remaining aromatic ring backbone atoms being carbon. It may be 5- or 6-membered monocyclic heteroaryl or polycyclic heteroaryl resulting from condensation with one or more benzene ring, and may be partially saturated. The heteroaryl also includes heteroaryl groups having single bond(s) therebetween.

The heteroaryl includes a divalent aryl group wherein the heteroatom(s) in the ring may be oxidized or quaternized to form, for example, an N-oxide or a quaternary salt. Specific examples include monocyclic heteroaryl such as furyl, thiophenyl, pyrrolyl, imidazolyl, pyrazolyl, thiazolyl, thiadiazolyl, isothiazolyl, isoxazolyl, oxazolyl, oxadiazolyl, triazinyl, tetrazinyl, triazolyl, tetrazolyl, furazanyl, pyridyl, pyrazinyl, pyrimidinyl, pyridazinyl, etc., polycyclic heteroaryl such as benzofuranyl, benzothiophenyl, isobenzofuranyl, benzimidazolyl, benzothiazolyl, benzoisothiazolyl, benzoisoxazolyl, benzoxazolyl, isoindolyl, indolyl, indazolyl, benzothiadiazolyl, quinolyl, isoquinolyl, cinnolinyl, quinazolinyl, quinoxalinyl, carbazolyl, phenanthridinyl, benzodioxolyl, etc., an N-oxide thereof (e.g., pyridyl N-oxide, quinolyl N-oxide, etc.), a quaternary salt thereof, etc., but are not limited thereto.

In the present invention, the alkyl moiety of "(C1-C30)alkyl, tri(C1-C30)alkylsilyl, di(C1-C30)alkyl(C6-C30)arylsilyl, (C6-C30)ar(C1-C30)alkyl, (C1-C30)alkyloxy, (C1-C30)alkylthio" or the like may have 1 to 20 carbon atoms, more specifically 1 to 10 carbon atoms. The aryl moiety of "(C6-C30)aryl, di(C1-C30)alkyl(C6-C30)arylsilyl, tri(C6-C30)arylsilyl, (C6-C30)ar(C1-C30)alkyl, (C6-C30)aryloxy, (C6-C30)arylthio" or the like may have 6 to 20 carbon atoms, more specifically 6 to 12 carbon atoms. The heteroaryl of "(C3-C30)heteroaryl" may have 4 to 20 carbon atoms, more specifically 4 to 12 carbon atoms. The cycloalkyl of "(C3-C30)cycloalkyl" may have 3 to 20 carbon atoms, more specifically 3 to 7 carbon atoms. The alkenyl or alkynyl of "(C2-C30)alkenyl or alkynyl" may have 2 to 20 carbon atoms, more specifically 2 to 10 carbon atoms.

of Chemical Formula 1 is selected from following structures but is not limited thereto:

wherein

the Y and Ar₁ through Ar₃ are the same as defined Chemical Formula 1.

Also,

of Chemical Formula 1 is selected from the following structures but is not limited thereto:

The organic electroluminescent compound according to the present invention may be specifically exemplified as following compounds but the present invention is not limited thereto.

Provided is an organic electroluminescent device, which comprises a first electrode; a second electrode; and one or more organic layer(s) interposed between the first electrode and the second electrode, wherein the organic layer comprises one or more organic electroluminescent compound(s) of Chemical Formula 1.

In the organic electroluminescent device, the organic layer comprises an electroluminescent layer including one or more phosphorescent dopant when one or more organic electroluminescent compounds of Chemical Formula 1 are used as the electroluminescent host. The dopant used in the organic electroluminescent device of the present invention is not particularly limited.

In the organic electronic device of the present invention, the organic layer may further include, in addition to the organic electroluminescent compound represented by Chemical Formula 1, one or more compound(s) selected from the group consisting of arylamine compounds and styrylarylamine compounds, at the same time. The arylamine compounds or styrylarylamine compounds are exemplified in Korean Patent Application No. 10-2008-0123276, 10-2008-0107606 or 10-2008-0118428, but are not limited thereto.

Further, in the organic electroluminescent device of the present invention, the organic layer may further include, in addition to the organic electroluminescent compound represented by Chemical Formula 1, one or more metal(s) selected from the group consisting of organic metals of Group 1, Group 2, 4th period and 5th period transition metals, lanthanide metals and d-transition elements or complex compound(s). The organic layer may include an electroluminescent layer and a charge generating layer.

Further, the organic layer may include, in addition to the organic electroluminescent compound of Chemical Formula 1, one or more organic electroluminescent layer(s) emitting blue, green or red light at the same time in order to embody a white-emitting organic electroluminescent device. The compounds emitting blue, green or red light may be exemplified by the compounds described in Korean Patent Application No. 10-2008-0123276, 10-2008-0107606 or 10-2008-0118428, but are not limited thereto.

In the organic electroluminescent device of the present invention, a layer (hereinafter referred to as "surface layer") selected from a chalcogenide layer, a metal halide layer and a metal oxide layer may be placed on the inner surface of one or both electrode(s) among the pair of electrodes. More specifically, a metal chalcogenide (including oxide) layer of silicon or aluminum may be placed on the anode surface of the electroluminescent medium layer, and a metal halide layer or metal oxide layer may be placed on the cathode surface of the electroluminescent medium layer. Operation stability may be attained therefrom. The chalcogenide may be, for example, SiO_x(1 ≤ x ≤ 2), AlO_x(1 ≤ x ≤ 1.5), SiON, SiAlON, etc. The metal halide may be, for example, LiF, MgF₂, CaF₂, a rare earth metal fluoride, etc. The metal oxide may be, for example, Cs₂O, Li₂O, MgO, SrO, BaO, CaO, etc.

In the organic electroluminescent device according to the present invention, it is also preferable to arrange on at least one surface of the pair of electrodes thus manufactured a mixed region of an electron transport compound and a reductive dopant, or a mixed region of a hole transport compound and an oxidative dopant. In that case, since the electron transport compound is reduced to an anion, injection and transport of electrons from the mixed region to an electroluminescent medium are facilitated. In addition, since the hole transport compound is oxidized to a cation, injection and transport of holes from the mixed region to an electroluminescent medium are facilitated. Preferable oxidative dopants include various Lewis acids and acceptor compounds. Preferable reductive dopants include alkali metals, alkali metal compounds, alkaline earth metals, rare-earth metals, and mixtures thereof. Further, a white-emitting electroluminescent device having two or more electroluminescent layers may be manufactured by employing a reductive dopant layer as a charge generating layer.

Since the organic electroluminescent compound according to the present invention exhibits good luminous efficiency and excellent life property when it is used as a host material of an organic electroluminescent material of an OLED device, it may be used to manufacture OLED devices having very superior operation life.

The present invention is further described with respect to organic electroluminescent compounds according to the present invention, processes for preparing the same, and luminescence properties of devices employing the same. However, the following examples are provided for illustrative purposes only and they are not intended to limit the scope of the present invention.

[Preparation Example 1] Preparation of Compound 1

Preparation of Compound A

After 2,7-dibromo-9,9-dimethylfluorene (150 g, 426 mmol) was steeped in a RBF (3 L) and nitrogen substituted, THF (2.1 L) was added. After cooling the solution to -78℃, n-BuLi (170 mL, 2.5M in hexane, 426 mmol) was added and stirred for 1 hour. After trimethylborate (53 mL, 469 mmol) was added and stirred for 12 hours. When the reaction was completed with 2M HCl, the mixture was extracted with ethyl acetate (EA)/H₂O. After removing moisture with MgSO₄ and performing distillation under reduced pressure, Compound A (70 g, 52%) was obtained by column separation under the condition of MC:Hexane=1:10.

Preparation of Compound B

Compound A (70, 220 mmol), 2-iodonitrobenzene (50 g, 200 mmol), Pd(PPh₃)₄(7 g, 6 mmol), Na₂CO₃(64 g, 600 mmol) were added to RBF. Toluene (1 L), EtOH (0.5 L), and H₂O (0.3 L) were added to the mixture. The reaction mixture was stirred at 90℃ for 7.5 hours. After extraction with EA/H₂O, moisture was removed with MgSO₄, and distillation was performed under reduced pressure. Crude Compound B (90 g) was obtained via silica filtration using methyl chloride (MC) as a developing solvent. Next reaction was performed without additional purification.

Preparation of Compound C

Compound B (90 g) was dissolved in P(OEt)₃(750 mL), 1,2-dichlorobenzene (750 mL), and stirred at 150℃ for 9 hours. After removing a solvent with distilled water, Compound C (26 g, 36%, two step yield) was obtained by performing column separation on obtained liquid under the condition of MC:Hexane=1:10.

Preparation of Compound D

Cyanuric chloride (50 g, 91 mmol) was added in a round bottom flask (RBF), dissolved in THF (1.3 L) and cooled to 0℃. Phenylmagnesium bromide (225 mL, 3M solution in diethyl ether, 675 mmol) was slowly added to the solution dropwise. The reaction solution was stirred for 3 hours and extracted with EA/H₂O. After removing moisture with MgSO₄ and performing distillation under reduced pressure, crude Compound D (37 g, 63%) was obtained by silica filtration using MC as a developing solvent. Compound D showed purity enough to be used in the next reaction.

Preparation of Compound E

DMF (40mL) was added in the RBF under the condition of N₂ and NaH (1.9 g, 60% dispersion in mineral oil, 50 mmol) was added thereto and stirred. A solution, in which Compound C (12 g, 33 mmol) was dissolved in DMF (80 mL), was slowly added to the suspension dropwise. After stirring the mixture for 1 hour, a solution, in which Compound D (10.6, g 40 mmol) was dissolved in DMF (100 mL), was slowly added to the mixture dropwise. The reaction mixture was stirred for 12 hours. After completing the reaction with H₂O, the mixture was extracted with EA/H₂O and distillation was performed under reduced pressure. Compound E (12 g, 61%) was obtained by performing column separation under the condition of MC:Hexane=1:10.

Preparation of Compound 1

Compound E (6 g, 10mmol), Compound F (3.2 g, 15.2mmol), Pd(PPh₃)₄(0.58 g, 0.5 mmol), and K₂CO₃(4.7 g, 34 mmol) were added in the RBF. Toluene (50 mL), EtOH (25 mL), and H₂O (17 mL) were added to the mixture. The reaction mixture was stirred at 90℃ for 12 hours and extracted with EA/H₂O. After removing moisture with MgSO₄ and performing distillation under reduced pressure, Compound 1 (4 g, 57%) was obtained by performing column separation under the condition of MC:Hexane=1:10.

[Preparation Example 2] Preparation of Compound 6

Preparation of Compound A

2,7-dibromo-9,9-dimethylfluorene (150 g, 426 mmol) was added in a RBF (3 L) and nitrogen substitution was performed. THF (2.1 L) was added to the solution and the solution was cooled to -78℃. After adding n-BuLi (170 mL, 2.5M in hexane, 426 mmol) to the solution, the mixture was stirred for 1 hour. After adding trimethylborate (53 mL, 469 mmol) to the mixture, the reaction mixture was stirred for 12 hours. After completing the reaction with 2M HCl, the reaction mixture was extracted with EA/H₂O. After removing moisture with MgSO₄ and performing distillation under reduced pressure, Compound A (70 g, 52%) was obtained by performing column separation under the condition of MC:Hexane=1:10.

Preparation of Compound B

Compound A (70 g, 220 mmol), 2-iodonitrobenzene (50 g, 200 mmol), Pd(PPh₃)₄(7 g, 6 mmol), and Na₂CO₃(64 g, 600 mmol) were added in a RBF. Toluene (1 L), EtOH (0.5 L),and H₂O (0.3 L) were added to the mixture. The reaction mixture was stirred at 90℃ for 7.5 hours and extracted with EA/H₂O. After removing moisture with MgSO₄ and performing distillation under reduced pressure, crude Compound B (90 g) was obtained via silica filtration using MC as a developing solvent. Next reaction was performed without additional purification.

Preparation of Compound C

Compound B (90 g) was dissolved in P(OEt)₃(750 mL), 1,2-dichlorobenzene (750 mL). The mixture was stirred at 150℃ for 9 hours and a solvent was removed by distilled water. Compound C (26 g, 36%, two step yield) was obtained by performing column separation on produced red liquid under the condition of MC:Hexane=1:10.

Preparation of Compound G

2,4,6-trichloropyrimidine (16.8 g, 91 mmol), phenylboronic acid (24.4 g, 200 mmol), Pd(PPh₃)₄(5.3 g, 4.6 mmol), and Na₂CO₃(29 g, 273 mmol) were added in a RBF. Toluene (350 mL), EtOH (100 mL), and H₂O (150 mL) were added to the mixture. The reaction mixture was stirred at 80℃ for 3 hours and extracted with EA/H₂O. After removing moisture with MgSO₄ and performing distillation under reduced pressure, Compound G (14 g, 58%) was obtained by column separation under the condition of MC:Hexane=1:10.

Preparation of Compound H

DMF (40 mL) was added in a RBF under the condition of N₂ and NaH (1.97 g, 60% dispersion in mineral oil, 49.3mmol) was added thereto and stirred. A solution, in which Compound C (11.9 g, 32.8 mmol) was dissolved in DMF (80 mL), was slowly added to the suspension dropwise. The mixture was stirred for about 1 hour. A solution, in which Compound G (10.5 g, 39.4 mmol) was dissolved in DMF (100 mL), was slowly added to the mixture dropwise. The reaction mixture was stirred for 12 hours. After completing the reaction with H₂O, the reaction mixture was extracted with EA/H₂O and distillation was performed under reduced pressure. Compound H (10 g, 51%) was obtained by column separation under the condition of MC:Hexane=1:10.

Preparation of Compound 6

Compound H (5 g, 8.4 mmol), Compound F (2.7, 13 mmol), Pd(PPh₃)₄(0.5 g, 0.4 mmol), and K₂CO₃(4 g, 29 mmol) were added to a RBF. Toluene (40 mL), EtOH (230 mL), and H₂O (14 mL) were added thereto. The reaction mixture was stirred at 90℃ for 12 hours and extracted with EA/H₂O. After removing moisture with MgSO₄ and performing distillation under reduced pressure, Compound 1 (4 g, 68%) was obtained by column separation under the condition of MC:Hexane=1:10.

[Preparation Example 3] Preparation of Compound 7

Preparation of Compound A

2,7-dibromo-9,9-dimethylfluorene (150 g, 426 mmol) was added in a RBF (3 L) and nitrogen substituted. THF (2.1 L) was added to the solution and the solution was cooled to -78℃. After adding n-BuLi (170 mL, 2.5M in hexane, 426 mmol), the mixture was stirred for 1 hour. After adding trimethylborate (53 mL, 469 mmol), the mixture was stirred for 12 hours. After completing the reaction with 2M HCl, the reaction mixture was extracted with EA/H₂O. After removing moisture with MgSO₄ and performing distillation under reduced pressure, Compound A (70 g, 52%) was obtained by column separation under the condition of MC:Hexane=1:10.

Preparation of Compound B

Compound A (70 g, 220 mmol), 2-iodonitrobenzene (50 g, 200 mmol), Pd(PPh₃)₄(7 g, 6 mmol), and Na₂CO₃(64 g, 600 mmol) were added in a RBF. Toluene (1 L), EtOH (0.5 L), and H₂O (0.3 L) were added thereto. The reaction mixture was stirred at 90℃ for 7.5 hours and extracted with EA/H₂O. After removing moisture with MgSO₄ and performing distillation under reduced pressure, crude Compound B (90 g) was obtained via silica filtration using MC as a developing solvent. Next reaction was performed without additional purification.

Preparation of Compound C

Preparation of Compound D

cyanuric chloride (50 g, 91 mmol) was added in a RBF, dissolved in THF (1.3 L) and cooled to 0℃. Phenylmagnesium bromide (225 mL, 3M solution in diethyl ether, 675 mmol) was slowly added to the solution dropwise. The reaction solution was stirred for 3 hours and extracted with EA/H₂O. After removing moisture with MgSO₄ and performing distillation under reduced pressure, crude Compound D (37 g, 63%) was obtained by silica filtration using MC as a developing solvent. Compound D showed purity enough to be used in the next reaction.

Preparation of Compound E

Preparation of Compound 7

Compound E (6 g, 10mmol), Compound I (3.2 g, 15.2mmol), Pd(PPh₃)₄(0.58 g, 0.5 mmol), and Na₂CO₃(2.1 g, 20 mmol) were added in a RBF. Toluene (60 mL), EtOH (30 mL), and H₂O (10 mL) were added thereto. The reaction mixture was stirred at 90℃ for 12 hours and extracted with EA/H₂O. After removing moisture with MgSO₄ and performing distillation under reduced pressure, Compound 7 (3.4 g, 49%) was obtained by column separation under the condition of MC:Hexane=1:10.

[Preparation Example 4] Preparation of Compound 8

Preparation of Compound A

After 2,7-dibromo-9,9-dimethylfluorene (150 g, 426 mmol) was steeped in a RBF (3 L) and nitrogen substituted, THF (2.1 L) was added. After cooling the solution to -78℃, n-BuLi (170 mL, 2.5M in hexane, 426 mmol) was added and stirred for 1 hour. Trimethylborate (53 mL, 469 mmol) was added to the mixture and stirred for 12 hours. When the reaction was completed with 2M HCl, the reaction mixture was extracted with ethyl acetate (EA)/H₂O. After removing moisture with MgSO₄ and performing distillation under reduced pressure, Compound A (70 g, 52%) was obtained by performing column separation on a produced solid under the condition of MC:Hexane=1:10.

Preparation of Compound B

Preparation of Compound C

Preparation of Compound G

Preparation of Compound H

Preparation of Compound 8

Compound H (5 g, 8.4 mmol), Compound I (2.7 g, 13 mmol), Pd(PPh₃)₄(0.5 g, 0.4 mmol), and Na₂CO₃(1.8 g, 17 mmol) were added in a RBF. Toluene (60 mL), EtOH (30 m), and H₂O (10 mL) were added thereto. The reaction mixture was stirred at 90℃ for 12 hours and extracted with EA/H₂O. After removing moisture with MgSO₄ and performing distillation under reduced pressure, Compound 8 (3.6 g, 62%) was obtained by column separation under the condition of MC:Hexane=1:10.

Organic electroluminescent compounds were prepared according to the procedure of Preparation Examples 1 to 4. ¹H NMR and MS/FAB data of thus prepared organic electroluminescent compounds are given in Table 1.

Table 1

compound	¹H NMR(CDCl₃, 200 MHz)	MS/FAB
compound	¹H NMR(CDCl₃, 200 MHz)	found	calculated
1	δ = 1.72(6H, s), 7.29(1H, m), 7.41(2H, m), 7.5~7.52(7H, m), 7.54(1H, s), 7.58~7.63(2H, m), 7.69(1H, m), 7.83(1H, m), 7.98(1H, m), 8.12~8.2(3H, m), 8.28(4H, m), 8.41~8.45(2H, m), 8.85(1H, s)	696.86	696.23
2	δ = 1.72(6H, s), 7.29(1H, m), 7.41(2H, m), 7.5~7.52(7H, m), 7.54(1H, s), 7.63(1H, m), 7.69(1H, m), 7.83(1H, m), 7.98(1H, m), 8.05~8.15(5H, m), 8.28(4H, m), 8.45(1H, m), 8.85(1H, s)	696.86	696.23
3	δ = 1.72(6H, s), 7.29(1H, m), 7.41(2H, m), 7.5~7.52(7H, m), 7.54(1H, s), 7.63(1H, m), 7.69(1H, m), 7.83~7.86(2H, m), 7.98~8(3H, m), 8.12~8.15(2H, m), 8.28(4H, m), 8.45(1H, m), 8.85(1H, s)	696.86	696.23
4	δ = 1.72(6H, s), 7.29(1H, m), 7.41(2H, m), 7.48~7.52(9H, m), 7.54(1H, s), 7.57~7.63(3H, m), 7.69~7.7(2H, m), 7.83(1H, m), 7.98(1H, m), 8.12~8.2(3H, m), 8.28(4H, m), 8.41~8.45(2H, m), 8.85(1H, s)	772.96	772.27
5	δ = 0.66(6H, s), 1.72(6H, s), 7.29(1H, m), 7.41(2H, m), 7.5~7.52(7H, m), 7.54(1H, s), 7.59~7.63(2H, m), 7.72(1H, m), 7.89(1H, m), 7.98(1H, m), 8.06~8.12(3H, m), 8.19(1H, m), 8.28(4H, m), 8.45(1H, m), 8.85(1H, s)	755.01	754.26
6	δ = 1.72(6H, s), 7.29(1H, m), 7.41(2H, m), 7.5~7.52(7H, m), 7.54(1H, s), 7.58~7.63(2H, m), 7.69(1H, m), 7.79~7.83(5H, m), 7.98(1H, m), 8.12~8.2(3H, m), 8.41~8.45(2H, m), 8.63(1H, s), 8.85(1H, s)	695.87	695.24
7	δ = 1.72(6H, s), 7.29~7.41(6H, m), 7.5~7.51(5H, m), 7.54(1H, s), 7.63~7.69(3H, m), 7.81~7.89(4H, m), 8.12~8.15(2H, m), 8.28(4H, m), 8.85(1H, s)	680.79	680.26
8	δ = 1.72(6H, s), 7.29~7.41(6H, m), 7.5~7.51(5H, m), 7.54(1H, s), 7.63~7.69(3H, m), 7.79~7.89(8H, m), 8.12~8.15(2H, m), 8.63(1H, s), 8.85(1H, s)	679.81	679.26
9	δ = 1.72(6H, s), 7.05(2H, m), 7.29~7.38(4H, m), 7.47~7.54(7H, m), 7.63~7.66(2H, m), 7.69(2H, s), 7.69(0H, m), 7.81~7.89(4H, m), 8.12~8.15(2H, m), 8.3(4H, m), 8.39(1H, s)	678.82	678.27
10	δ = 1.72(6H, s), 7.25(1H, m), 7.32~7.41(6H, m), 7.51(4H, m), 7.66~7.71(3H, m), 7.79~8(10H, m), 8.15(1H, m), 8.55(1H, m), 8.63(1H, s)	679.81	679.26
11	δ = 1.72(6H, s), 7.25(1H, m), 7.32~7.41(6H, m), 7.51(5H, m), 7.66~7.69(2H, m), 7.79~7.94(10H, m), 8.15(1H, m), 8.55(1H, m), 8.63(1H, s)	679.81	679.26
12	δ = 1.72(6H, s), 7.25(1H, m), 7.32~7.41(6H, m), 7.51~7.52(6H, m), 7.66~7.69(2H, m), 7.79~7.94(9H, m), 8.15(1H, m), 8.55(1H, m), 8.63(1H, s)	679.81	679.26
13	δ = 1.72(6H, s), 7.25(1H, m), 7.32~7.44(7H, m), 7.51(4H, m), 7.66~7.69(2H, m), 7.79~8(10H, m), 8.15(1H, m), 8.55(1H, m), 8.63(1H, s)	679.81	679.26
14	δ = 1.72(6H, s), 7.29(1H, m), 7.37(4H, m), 7.45~7.52(10H, m), 7.54(1H, s), 7.55~7.63(6H, m), 7.72(1H, m), 7.89(1H, m), 7.98(1H, m), 8.06~8.12(3H, m), 8.19(1H, m), 8.45(1H, m), 8.85(1H, s)	724.00	723.24
15	δ = 0.66(6H, s), 7.29~7.35(2H, m), 7.41(2H, m), 7.5~7.52(7H, m), 7.58~7.63(2H, m), 7.72(1H, s), 7.82(1H, m), 7.89(1H, s), 7.95~7.98(2H, m), 8.12(1H, m), 8.2(1H, m), 8.28(4H, m), 8.41~8.45(2H, m)	721.93	712.21
16	δ = 7.29(1H, m), 7.41(2H, m), 7.5~7.52(7H, m), 7.58~7.63(2H, m), 7.78(1H, s), 7.86(1H, s), 7.98(1H, m), 8.05~8.12(4H, m), 8.2(1H, m), 8.28(4H, m), 8.41~8.45(2H, m)	686.84	686.16
17	δ = 0.66(6H, s), 7.29~7.41(7H, m), 7.5~7.51(5H, m), 7.63~7.66(2H, m), 7.72(1H, s), 7.81~7.85(3H, m), 7.89(2H, s), 7.89(0H, m), 7.95(1H, m), 8.12(1H, m), 8.28(4H, m)	696.87	696.23
18	δ = 7.29~7.41(6H, m), 7.5~7.51(5H, m), 7.63~7.66(2H, m), 7.78(1H, s), 7.81~7.85(2H, m), 7.86(1H, s), 7.89(1H, m), 8.05~8.12(4H, m), 8.28(4H, m)	670.78	670.18
19	δ = 1.72(6H, s), 7.06(1H, m), 7.29(1H, m), 7.45~7.53(9H, m), 7.54(1H, s), 7.58~7.69(6H, m), 7.88(1H, m), 7.98(1H, m), 8.12(1H, m), 8.2(1H, m), 8.28(1H, m), 8.36~8.46(4H, m), 8.85(1H, s)	694.88	694.24

[Example 1] Manufacture of OLED device using the organic electroluminescent compound according to the present invention

An OLED device was manufactured using the electroluminescent material according to the present invention. First, a transparent electrode ITO thin film (15 Ω/□) obtained from a glass for OLED (produced by Samsung Corning) was subjected to ultrasonic washing with trichloroethylene, acetone, ethanol and distilled water, sequentially, and stored in isopropanol before use.

Then, an ITO substrate was equipped in a substrate folder of a vacuum vapor deposition apparatus, and 4,4',4"-tris(N,N-(2-naphthyl)-phenylamino)triphenylamine (2-TNATA) was placed in a cell of the vacuum vapor deposition apparatus, which was then ventilated up to 10^-6 torr of vacuum in the chamber. Then, electric current was applied to the cell to evaporate 2-TNATA, thereby forming a hole injection layer having a thickness of 60 nm on the ITO substrate. Then, N,N'-bis(α-naphthyl)-N,N'-diphenyl-4,4'-diamine (NPB) was placed in another cell of the vacuum vapor deposition apparatus, and electric current was applied to the cell to evaporate NPB, thereby forming a hole transport layer having a thickness of 20 nm on the hole injection layer.

After forming the hole injection layer and the hole transport layer, an electroluminescent layer was formed thereon as follows. Compound 1 was placed in a cell of a vacuum vapor deposition apparatus as a host, and Ir(ppy)₃[tris(2-phenylpyridine)iridium] was placed in another cell as a dopant. The two materials were evaporated at different rates such that an electroluminescent layer having a thickness of 30 nm was vapor-deposited on the hole transport layer through doping at 4 to 10 wt%.

Subsequently, tris(8-hydroxyquinoline)-aluminum(III) (Alq) was vapor-deposited with a thickness of 20 nm as an electron transport layer on the electroluminescent layer. Then, after vapor-depositing lithium quinolate (Liq) of a following structure with a thickness of 1 to 2 nm as an electron injection layer, an Al cathode having a thickness of 150 nm was formed using another vacuum vapor deposition apparatus to manufacture an OLED.

Each compound used in the OLED was purified by vacuum sublimation at 10^-6torr.

As a result, it was confirmed that current of 4.3 mA/cm² flows at voltage of 6.3 V and a green light of 1310 cd/m² was emitted.

[Example 2]

An OLED device was manufactured as in Example 1 except that Compound 6 was added as a host material on the electroluminescent layer.

As a result, it was confirmed that current of 4.3 mA/cm² flows at voltage of 6.6 V and a green light of 1220 cd/m² was emitted.

[Example 3]

An OLED device was manufactured as in Example 1 except that Compound 10 was added as a host material on the electroluminescent layer.

As a result, it was confirmed that current of 4.1 mA/cm² flows at voltage of 6.4 V and a green light of 1150 cd/m² was emitted.

[Comparative Example 1] Manufacture of OLED device using conventional electroluminescent material

An OLED device was manufactured in the same manner as Example 1 except that Bis(2-methyl-8-quinolinato)(p-phenylphenolato) aluminum(III)(BAlq) instead of the electroluminescent compound of the present invention as a host material at another cell of the vacuum vapor deposition apparatus was used as an electroluminescent host material after forming the hole injection layer and hole transport layer according to the same manner as Example 1.

An OLED device was manufactured in the same manner as Example 1 except that 4,4'-bis(carbazol-9-yl)biphenyl (CBP) instead of the compounds of the present invention as a host material on the electroluminescent layer and bis(2-methyl-8-quinolinato)(p-phenylphenolato)aluminum(III) (BAlq) as a hole blocking layer were used.

As a result, it was confirmed that current of 3.9 mA/cm² flows at voltage of 7.5 V and a green light of 1000 cd/m² was emitted.

The organic electroluminescent compounds according to the present invention have excellent properties compared with the conventional material. In addition, the device using the organic electroluminescent compound according to the present invention as a host material has excellent electroluminescent properties and drops driving voltage of 0.9 to 1.2 V, thereby increasing power efficiency and improving power consumption.

Claims

An organic electroluminescent compound represented Chemical Formula 1:

[Chemical Formula 1]

[Chemical Formula 2]

wherein

the
is the same as defined in Chemical Formula 2,

the X represents -O- or -S-; Y represents -S-, -C(R₁)(R₂)-, -Si(R₃)(R₄)-, -N(R₅)- or a divalent group selected from the group consisting of the following structures;

the Ar₁ through Ar₅ and the R₁ through R₅ independently represent hydrogen, deuterium, (C1-C30)alkyl, halo(C1-C30)alkyl, halogen, cyano, (C3-C30)cycloalkyl, 5- to 7-membered heterocycloalkyl, (C2-C30)alkenyl, (C2-C30)alkynyl, (C6-C30)aryl, (C1-C30)alkoxy, (C6-C30)aryloxy, (C3-C30)heteroaryl, (C6-C30)ar(C1-C30)alkyl, (C6-C30)arylthio, mono or di(C1-C30)alkylamino, mono or di(C6-C30)arylamino, tri(C1-C30)alkylsilyl, di(C1-C30)alkyl(C6-C30)arylsilyl, tri(C6-C30)arylsilyl, nitro or hydroxyl, or each of them may be linked to an adjacent substituent via (C3-C30)alkylene or (C3-C30)alkenylene with or without a fused to form an alicyclic ring, a mono- or polycyclic aromatic ring or a mono- or polycyclic heteroaromatic ring;

each of alkyl, cycloalkyl, heterocycloalkyl, alkenyl, alkynyl, aryl and heteroaryl of the Ar₁ through Ar₅and R₁ through R₅ may be further substituted by one or more substituent(s) selected from the group consisting of deuterium, (C1-C30)alkyl, halo(C1-C30)alkyl, halogen, cyano, (C3-C30)cycloalkyl, 5- to 7-membered heterocycloalkyl, (C2-C30)alkenyl, (C2-C30)alkynyl, (C6-C30)aryl, (C1-C30)alkoxy, (C6-C30)aryloxy, (C3-C30)heteroaryl, (C3-C30)heteroaryl with (C1-C30)alkyl substituent(s), (C3-C30)heteroaryl with (C6-C30)aryl substituent(s), (C6-C30)ar(C1-C30)alkyl, (C6-C30)arylthio, mono or di(C1-C30)alkylamino, mono or di(C6-C30)arylamino, tri(C1-C30)alkylsilyl, di(C1-C30)alkyl(C6-C30)arylsilyl, tri(C6-C30)arylsilyl, nitro or hydroxyl;

the L₁ through L₃ independently represent a chemical bond or a divalent group selected from the group consisting of (C6-C30)arylene, (C3-C30)heteroarylene, di(C1-C30)alkylsilyl or di(C6-C30)arylsilyl group; and

the heterocycloalkyl, heteroaryl and heteroaromatic ring may contain one or more heteroatom(s) selected from B, N, O and S.
The organic electroluminescent compound according to claim 1, wherein
of Chemical Formula 1 is selected from following structures but is not limited thereto.

wherein

the Y and Ar₁ through Ar₃ are the same as defined in Claim 1.
The organic electroluminescent compound according to claim 1,
of Chemical Formula 1 is selected from the following structures:
An organic electroluminescent device comprising the organic electroluminescent compound according to any of claims 1 to 3.
The organic electroluminescent device according to claim 4, which comprises a first electrode; a second electrode; and one or more organic layer(s) interposed between the first electrode and the second electrode, wherein the organic layer comprises one or more organic electroluminescent compound(s) and one or more phosphorescent dopant(s).
The organic electroluminescent device according to claim 5, wherein the organic layer further comprises one or more amine compound(s) selected from the group consisting of arylamine compounds and styrylarylamine compounds.
The organic electroluminescent device according to claim 5, wherein the organic layer further comprises one or more metal(s) selected from the group consisting of organic metals of Group 1, Group 2, 4th period and 5th period transition metals, lanthanide metals and d-transition elements or complex compound(s).
The organic electroluminescent device according to claim 5, wherein the organic layer comprises an electroluminescent layer and a charge generating layer.
The organic electroluminescent device according to claim 5, which is a white light-emitting organic electroluminescent device wherein the organic layer further comprises one or more organic electroluminescent layer(s) emitting blue, red or green light.