CN102947294A - Novel organic electroluminescent compounds and organic electroluminescent device using the same - Google Patents

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 compound and organic electroluminescent device using the same

【Technical field】

The present invention relates to a novel organic electroluminescent compound and an organic electroluminescent device using the compound. More specifically, it relates to novel organic electroluminescent compounds used as organic electroluminescent materials and organic electroluminescent devices using the compounds.

【Background technique】

The most important factor determining the luminous efficiency of an organic light emitting diode (OLED) is the organic electroluminescent material. Although fluorescent materials have been widely used as organic electroluminescent materials so far, in view of the electroluminescent mechanism, the development of phosphorescent materials is one of the best methods to theoretically increase the luminous efficiency to 4 times the original. So far, iridium(III) complexes have been widely known as phosphorescent materials, including (acac)Ir(btp) ₂ , Ir(ppy) ₃ and Firpic, which emit red, green and blue light, respectively. Especially in Japan, Europe and the United States, many phosphorescent materials have been investigated recently.

CBP is currently best known as a host material for phosphorescent materials. High-efficiency OLEDs using hole-blocking layers including BCP, BAlq, etc. have been reported. High performance OLEDs using BAlq derivatives as substrates have been reported by Pioneer (Japan) and others.

Although these materials provide good electroluminescent properties, they still have the disadvantage that they may degrade due to low glass transition temperature and poor thermal stability during the high temperature deposition process in vacuum. Since the power efficiency of an OLED is represented by (π/voltage)×current efficiency, the power efficiency is inversely proportional to voltage. Therefore, reducing the power consumption of OLEDs requires high power efficiency. In fact, OLEDs using phosphorescent materials provide superior current power (cd/A) compared to OLEDs using fluorescent materials. However, when using existing materials (such as BAlq, CBP, etc.) Significantly better than the power efficiency of OLEDs using fluorescent materials. Furthermore, the OLED device does not have a satisfactory operating lifetime. Therefore, it is necessary to develop more stable and high-performance matrix materials.

【Content of invention】

technical problem

Through extensive efforts to overcome the above-mentioned conventional technical problems, the inventors of the present application have discovered novel electroluminescent compounds that realize organic electroluminescent devices having excellent luminous efficiency and remarkably improved lifetime properties.

It is an object of the present invention to provide organic electroluminescent compounds having a framework that provides better luminous efficiency and device lifetime with proper color coordinates compared to conventional dopant materials while solving the aforementioned problems. Another object of the present invention is to provide an organic electroluminescent device having high luminous efficiency and improved lifetime properties.

technical solution

The present invention provides a novel organic electroluminescent compound represented by Chemical Formula 1 and an organic electroluminescent device using the compound. Since the organic electroluminescent compound of the present invention has good luminous efficiency and excellent lifetime properties compared with existing host materials, it can be used to manufacture OLED devices with very superior operating lifetimes.

chemical formula 1

chemical formula 2

的定义与化学式2中的定义相同，in,

The definition of is the same as that in Chemical Formula 2,

X represents -O- or -S-; Y represents -S-, -C(R ₁ )(R ₂ )-, -Si(R ₃ )(R ₄ )-, -N(R ₅ )- or selected from The divalent radical of the following structure;

Ar ₁ to Ar ₅ and R ₁ to R ₅ independently represent hydrogen, deuterium, (Cl-C30) alkyl, halogen (Cl-C30) alkyl, halogen, cyano, (C3-C30) cycloalkyl, 5 To 7-membered heterocycloalkyl. (C2-C30) alkenyl, (C2-C30) alkynyl, (C6-C30) aryl, (Cl-C30) alkoxy, (C6-C30) aryloxy, (C3-C30) heteroaryl, (C6-C30) aryl (Cl-C30) alkyl, (C6-C30) arylthio, mono or bis (Cl-C30) alkylamino, mono or bis (C6 -C30) arylamino, three (Cl-C30) alkyl silyl (tri (Cl-C30) alkylsilyl), two (Cl-C30) alkyl (C6-C30) aryl silyl, three ( C6-C30) arylsilyl, nitro or hydroxyl, or each of them is bonded to the phase via a (C3-C30) alkylene or (C3-C30) alkenylene with or without fused rings ortho substituents to form an alicyclic ring, a monocyclic or polycyclic aromatic ring, or a monocyclic or polycyclic heteroaromatic ring;

Each of the alkyl, cycloalkyl, heterocycloalkyl, alkenyl, alkynyl, aryl, and heteroaryl groups of Ar to _Ar and _{R to R} may be further substituted by one or more substituents , the substituent is selected from deuterium, (Cl-C30) alkyl, halogen (Cl-C30) alkyl, halogen, cyano, (C3-C30) cycloalkyl, 5 to 7 membered heterocycloalkyl.( C2-C30) alkenyl, (C2-C30) alkynyl, (C6-C30) aryl, (Cl-C30) alkoxy, (C6-C30) aryloxy, (C3-C30) heteroaryl, (C3-C30)heteroaryl with (Cl-C30)alkyl substituent, (C3-C30)heteroaryl with (C6-C30)aryl substituent, (C6-C30)aryl(Cl- C30) alkyl, (C6-C30) arylthio, mono or di (Cl-C30) alkylamino, mono or bis (C6-C30) arylamino, tri (Cl-C30) alkyl silyl , two (Cl-C30) alkyl (C6-C30) aryl silyl, three (C6-C30) aryl silyl, nitro or hydroxyl;

L ₁ to L ₃ independently represent chemical bonds or are selected from (C6-C30) arylene, (C3-C30) heteroarylene, bis (Cl-C30) alkylsilyl or bis (C6-C30) arylene a divalent group of a silyl group; and

The heterocycloalkyl, heteroaryl and heteroaryl rings may contain one or more heteroatoms selected from B, N, O and S.

In the present invention, "alkyl", "alkoxy" and other substituents containing "alkyl" include straight chain and branched chain.

基、稠四苯基(naphthacenyl)、荧蒽基(fluoranthenyl)等，但并不限于此。该萘基包括1-萘基及2-萘基。而该蒽基包括1-蒽基、2-蒽基及9-蒽基。且该芴基包括1-芴基、2-芴基、3-芴基、4-芴基以及9-芴基。本发明中，“杂芳基”意指含有作为芳香环骨架原子的1个至4个选自B、N、O及S的杂原子及其它剩余芳香环骨架原子为碳的芳基。该杂芳基可为5元或6元单环杂芳基或与一个或多个苯环缩合而得的多环杂芳基，且可呈部分饱和。该杂芳基亦可包含其间具有一个或多个单键的杂芳基。In the present invention, "aryl" means an organic group obtained by removing one hydrogen atom from an aromatic hydrocarbon, and may contain 4 to 7 members, especially 5 or 6 membered single or condensed rings, including multiple Aryl with one or more single bonds. Specific examples of the aryl group include: phenyl, naphthyl, biphenyl, anthracenyl, indenyl, fluorenyl, phenanthrenyl, triphenylenyl, pyrenyl, perylenyl,

group, condensed tetraphenyl (naphthacenyl), fluoranthenyl (fluoranthenyl), etc., but not limited thereto. The naphthyl includes 1-naphthyl and 2-naphthyl. The anthracenyl includes 1-anthracenyl, 2-anthracenyl and 9-anthracenyl. And the fluorenyl group 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 heteroatoms selected from B, N, O and S as aromatic ring skeleton atoms and the remaining aromatic ring skeleton atoms are carbon. The heteroaryl group may be a 5-membered or 6-membered monocyclic heteroaryl group or a polycyclic heteroaryl group condensed with one or more benzene rings, and may be partially saturated. The heteroaryl group may also include heteroaryl groups having one or more single bonds therebetween.

唑基、

唑基、

二唑基、三嗪基、四嗪基、三唑基、四唑基、呋咱基、吡啶基、吡嗪基、嘧啶基、哒嗪基等；多环杂芳基，诸如苯并呋喃基、苯并噻吩基、异苯并呋喃基、苯并咪唑基、苯并噻唑基、苯并异噻唑基、苯并异唑基、苯并唑基、异吲哚基、吲哚基、吲唑基、苯并噻二唑基、喹啉基、异喹啉基、噌啉基、喹唑啉基、喹喔啉基、咔唑基、啡啶基及苯并二氧杂环戊基(benzodioxolyl)等；其N-氧化物（诸如：吡啶基N-氧化物及喹啉N-氧化物等）、及其季盐等，但并不限于此。The heteroaryl group includes divalent aryl groups in which ring heteroatoms can be oxidized or quaternized to form such as N-oxides and quaternized salts. Specific examples thereof include: monocyclic heteroaryl groups such as furyl, thienyl, pyrrolyl, imidazolyl, pyrazolyl, thiazolyl, thiadiazolyl, isothiazolyl, isothiazolyl,

Azolyl,

Azolyl,

Diazolyl, triazinyl, tetrazinyl, triazolyl, tetrazolyl, furazanyl, pyridyl, pyrazinyl, pyrimidinyl, pyridazinyl, etc.; polycyclic heteroaryl, such as benzofuryl , benzothienyl, isobenzofuryl, benzimidazole, benzothiazolyl, benzisothiazolyl, benziso Azolyl, benzo Azolyl, isoindolyl, indolyl, indazolyl, benzothiadiazolyl, quinolinyl, isoquinolyl, cinnolinyl, quinazolinyl, quinoxalinyl, carbazolyl, phenanthryl and benzodioxolyl (benzodioxolyl), etc.; their N-oxides (such as: pyridyl N-oxide and quinoline N-oxide, etc.), and their quaternary salts, etc., but not limited to this.

In the present invention, "(C1-C30) alkyl, tri(Cl-C30) alkyl silyl, two (Cl-C30) alkyl (C6-C30) aryl silyl, (C6-C30) aromatic The alkyl moiety of "(Cl-C30)alkyl, (Cl-C30)alkoxy, (Cl-C30)alkylthio" or the like may have from 1 to 20 carbon atoms, more specifically 1 to 10 carbon atoms. "(C6-C30) aryl, two (Cl-C30) alkyl (C6-C30) aryl silyl, three (C6-C30) aryl silyl, (C6-C30) aryl (Cl- The aryl moiety of "C30)alkyl, (C6-C30)aryloxy, (C6-C30)arylthio" or the like may have from 6 to 20 carbon atoms, more specifically from 6 to 12 carbons atom. The heteroaryl moiety of "(C3-C30)heteroaryl" may have 4 to 20 carbon atoms, more specifically 4 to 12 carbon atoms. The cycloalkyl moiety of "(C3-C30)cycloalkyl" may have 3 to 20 carbon atoms, more specifically 3 to 7 carbon atoms. The alkenyl or alkynyl moiety of "(C2-C30)alkenyl or alkynyl" may have 2 to 20 carbon atoms, more specifically 2 to 10 carbon atoms.

chemical formula 1

Selected from the following structures, but not limited thereto.

in,

The definitions of Y and Ar ₁ to Ar ₃ are the same as those in Chemical Formula 1.

And, *—L ₁ —L ₂ —L ₃ —* of Chemical Formula 1 is selected from the following structures, but not limited thereto:

The organic electroluminescence compound of the present invention can be specifically listed by the following compounds, but the present invention is not limited to the following compounds.

The present invention provides an organic electroluminescent device, which includes a first electrode: a second electrode; and one or more organic layers placed between the first electrode and the second electrode; wherein the organic layer includes a One or more organic electroluminescent compounds represented by Chemical Formula 1.

In the organic electroluminescent device, when using one or more organic electroluminescent compounds of Chemical Formula 1 as an electroluminescent host, the organic layer includes an electroluminescent layer containing one or more phosphorescent dopants . There is no particular limitation on the dopant used in the organic electroluminescent device of the present invention.

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

Furthermore, in the organic electroluminescent device of the present invention, in addition to the organic electroluminescent compound represented by Chemical Formula 1, the organic layer may further contain one or more organic metals selected from Group 1, Group 2 Metals or complexes of transition metals, lanthanide metals, and d-transition elements of the group, period 4 and period 5. The organic layer may include an electroluminescent layer and a charge generating layer.

In addition, in addition to the organic electroluminescent compound represented by Chemical Formula 1, the organic layer can also include one or more organic electroluminescent layers that emit blue light, green light or red light at the same time, so as to realize the effective emission of white light. Electromechanical Luminescent Devices. Compounds emitting blue, green, or red light are disclosed in compounds described in Korean Patent Application No. 10-2008-0123276, No. 10-2008-0107606, or Korean Patent Application No. 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 provided on the electrode. on the inner surface of one or both electrodes. More specifically, a layer of metal chalcogenides (including oxides) of silicon or aluminum may be disposed on the anode surface of the electroluminescent medium layer, and a metal halide layer or metal oxide layer may be disposed on the The cathode surface of the electroluminescence medium layer. Thereby, operational stability can be obtained. The chalcogen compound may be, for example, _SiOx (1≤x≤2), _AlOx (1≤x≤1.5), SiON, SiAlON, or the like. The metal halide may be, for example, LiF, MgF ₂ , CaF ₂ , fluorides of rare earth metals, and the like. The metal oxide may be, for example, _Cs2O , _Li2O , MgO, SrO, BaO, CaO, or the like.

In the organic electroluminescent device of the present invention, it is also preferred that a mixed region of an electron-transport compound and a reducing dopant or a mixed region of a hole-transport compound and an oxidizing dopant be arranged on at least one of the thus produced electrode pairs. On the surface. In this case, since the electron transport compound is reduced to an anion, electrons are easily injected and transported from the mixed region to the electroluminescent medium. In addition, since the hole transport compound is oxidized into a cation, holes are easily injected and transported from their mixed region to the electroluminescent medium. Preferred oxidative dopants include various Lewis acids and acceptor compounds. Preferred reductive dopants, however, include alkali metals, alkali metal compounds, alkaline earth metals, rare earth metals, and mixtures thereof. Furthermore, a white light emitting electroluminescent device having two or more electroluminescent layers can be fabricated by using a reducing dopant layer as a charge generation layer.

beneficial effect

Since the organic electroluminescent compound of the present invention is used as a host material of an organic electroluminescent material of an OLED device, it has good luminous efficiency and excellent lifetime characteristics, so it can be used to manufacture an OLED with a very superior operating lifetime.

Detailed ways

The present invention further illustrates the light-emitting properties with respect to the organic electroluminescent compounds of the present invention, processes for the preparation of the compounds, and devices using the compounds. However, the following specific examples are for illustration only and are not intended to limit the scope of the present invention in any way.

[Preparation Example 1] Preparation of Compound 1

Preparation of Compound A

First, 2,7-dibromo-9,9-dimethylfluorene (150 grams (g), 426 millimoles (mmol)) was soaked in RBF (3 liters (L)) and replaced with nitrogen, then added THF ( 2.1L). After the solution was cooled to -78°C, n-BuLi (170 mL, 2.5 molar (M) in hexane, 426 mmol) was added and stirred for another 1 hour. Trimethylborate (53 mL, 469 mmol) was then added and stirred for 12 hours. When the reaction was complete with 2M HCl, the mixture was extracted with ethyl acetate (EA)/water. After removing moisture with MgSO ₄ and distilling under reduced pressure, the compound A (70 g, 52%) was obtained by column separation (condition: MC:hexane=1:10).

Preparation of Compound B

Compound A (70, 220 mmol), 2-iodonitrobenzene (50 g, 200 mmol), Pd(PPh ₃ ) ₄ (7 g, 6 mmol), Na ₂ CO ₃ (64 g, 600 mmol) were added to RBF. Toluene (1 L), EtOH (0.5 L) and water (0.3 L) were then added to the mixture. The reaction mixture was stirred at 90°C for 7.5 hours. After extraction with EA/water, the remaining water was removed with MgSO ₄ and distilled under reduced pressure. Crude compound B (90 g) was obtained by filtration through silica using methyl chloride (MC) as a developing solvent. The 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° C. for 9 hours. After removing the solvent with distilled water, compound C (26 g, 36%, two-step total yield) was obtained by column separation of the obtained liquid (condition: MC:hexane=1:10).

Preparation of Compound D

Cyanuric chloride (50 g, 91 mmol) was charged into a round bottom flask (RBF) and dissolved in THF (1.3 L) and cooled to 0 °C. Phenylmagnesium bromide (225 mL, 3M in diethyl ether, 675 mmol) was then slowly added dropwise to the solution. The reaction solution was stirred for 3 hours and extracted with EA/ _H2O . After removal of water with MgSO ₄ and distillation under reduced pressure, crude compound D (37 g, 63%) was obtained by filtration through silica using MC as a developing agent. Compound D was shown to be sufficiently pure for the next reaction.

Preparation of Compound E

Under N ₂ condition, DMF (40 mL) was added to RBF and NaH (1.9 g, 60% dispersion in mineral oil, 50 mmol) was added to RBF and stirred. Then a solution of Compound C (12 g, 33 mmol) dissolved in DMF (80 mL) was slowly added dropwise to the suspension. After the mixture was stirred for 1 hour, a solution of compound D (10.6 g, 40 mmol) dissolved in DMF (100 mL) was slowly added dropwise to the mixture. The reaction mixture was stirred for 12 hours. When the reaction was completed with _H2O , the mixture was extracted with EA/ _H2O and distilled under reduced pressure. Compound E (12 g, 61%) was obtained by performing column separation (condition: MC:hexane=1:10).

Preparation of compound 1

Compound E (6 g, 10 mmol), Compound F (3.2 g, 15.2 mmol), Pd(PPh ₃ ) ₄ (0.58 g, 0.5 mmol), and K ₂ CO ₃ (4.7 g, 34 mmol) were added to the RBF. Then toluene (50 mL), EtOH (25 mL) and _H20 (17 mL) were added to the mixture. The reaction mixture was stirred at 90°C for 12 hours and extracted with EA/ _H2O . After removal of water with MgSO ₄ and distillation under reduced pressure, compound 1 (4 g, 57%) was obtained by column separation (condition: MC:hexane=1:10).

[Preparation Example 2] Preparation of Compound 6

Preparation of Compound A

Firstly, 2,7-dibromo-9,9-dimethylfluorene (150 g, 426 mmol) was added into RBF (3 L) and replaced with nitrogen. THF (2.1 L) was added to this solution and the solution was cooled to -78°C. After adding n-BuLi (170 mL, 2.5M in hexane, 426 mmol) to the solution, the mixture was stirred for an additional 1 hour. After addition of trimethyl borate (53 mL, 469 mmol), the reaction mixture was stirred for 12 hours. When the reaction was complete with 2M HCl, the reaction mixture was extracted with EA/ _H2O . After removing moisture with MgSO ₄ and distilling under reduced pressure, compound A (70 g, 52%) was obtained by column separation (condition: MC:hexane=1:10).

Preparation of Compound B

Compound A (70 g, 220 mmol), 2-iodonitrobenzene (50 g, 200 mmol), Pd(PPh ₃ ) ₄ (7 g, 6 mmol), Na ₂ CO ₃ (64 g, 600 mmol) were added to the RBF. Toluene (1 L), EtOH (0.5 L) and _H2O (0.3 L) were then added to the mixture. The reaction mixture was stirred at 90°C for 7.5 hours and extracted with EA/ _H2O . After removing moisture with MgSO ₄ and distilling under reduced pressure, crude compound B (90 g) was obtained by filtering through silica using MC as a developing solvent. The next reaction was carried out 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°C for 9 hours, and the solvent was removed with distilled water. Compound C (26 g, 36%, two-step total yield) was obtained by column separation of the produced red liquid (condition: MC:hexane=1:10).

Preparation of Compound G

2,4,6-trichloropyrimidine (16.8g, 91mmol), phenylboronic acid (24.4g, 200mmol), Pd(PPh ₃ ) ₄ (5.3g, 4.6mmol), and Na ₂ CO ₃ (29g, 273mmol) Join the RBF. Then toluene (350 mL), EtOH (100 mL) and _H2O (150 mL) were added to the mixture. The reaction mixture was stirred at 80°C for 3 hours and extracted with EA/ _H2O . After removing moisture with MgSO ₄ and distilling under reduced pressure, the compound G (14 g, 58%) was obtained by column separation (condition: MC:hexane=1:10).

Preparation of Compound H

DMF (40 mL) was added to the RBF under N ₂ and NaH (1.97 g, 60% dispersion in mineral oil, 49.3 mmol) was added to the RBF and stirred. Then a solution of Compound C (11.9 g, 32.8 mmol) dissolved in DMF (80 mL) was slowly added dropwise to the suspension. The mixture was stirred for about 1 hour. A solution of compound G (10.5 g, 39.4 mmol) dissolved in DMF (100 mL) was slowly added dropwise to the mixture, and the reaction mixture was stirred for 12 hours. When the reaction was completed with _H2O , the mixture was extracted with EA/ _H2O and distilled under reduced pressure. Compound H (10 g, 51%) was obtained by column separation (condition: MC:hexane=1:10).

Preparation of compound 6

Compound H (5 g, 8.4 mmol), Compound F (2.7, 13 mmol), Pd(PPh ₃ ) ₄ (0.5 g, 0.4 mmol), and K ₂ CO ₃ (4 g, 29 mmol) were added to the RBF. Then toluene (40 mL), EtOH (230 mL) and _H2O (14 mL) were added thereto. The reaction mixture was stirred at 90°C for 12 hours and extracted with EA/ _H2O . After removal of water with MgSO ₄ and distillation under reduced pressure, compound 1 (4 g, 68%) was obtained by column separation (condition: MC:hexane=1:10).

[Preparation Example 3] Preparation of Compound 7

Preparation of Compound A

2,7-dibromo-9,9-methylfluorene (150 g, 426 mmol) was first added to RBF (3 L) and replaced with nitrogen. Further THF (2.1 L) was added to the solution, and the solution was cooled to -78°C. After addition of n-BuLi (170 mL, 2.5 M in hexanes, 426 mmol), the mixture was stirred for an additional 1 h. After trimethyl borate (53 mL, 469 mmol) was added, the mixture was stirred for 12 hours. When the reaction was complete with 2M HCl, the mixture was extracted with EA/ _H2O . Moisture was removed with MgSO ₄ and distilled under reduced pressure, and separated by column (condition: MC:hexane=1:10) to obtain compound A (70 g, 52%).

Preparation of Compound B

Compound A (70 g, 220 mmol), 2-iodonitrobenzene (50 g, 200 mmol), Pd(PPh ₃ ) ₄ (7 g, 6 mmol), Na ₂ CO ₃ (64 g, 600 mmol) were added to the RBF. Then toluene (1 L), EtOH (0.5 L) and _H2O (0.3 L) were added. The reaction mixture was stirred at 90°C for 7.5 hours and extracted with EA/ _H20 . After removing moisture with MgSO ₄ and distilling under reduced pressure, crude compound B (90 g) was obtained by filtering through silica using MC as a developing solvent. The next reaction was carried out 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°C for 9 hours and the solvent was removed with distilled water. Compound C (26 g, 36%, two-step total yield) was obtained by column separation of the produced red liquid (condition: MC:hexane=1:10).

Preparation of Compound D

Cyanuric chloride (50 g, 91 mmol) was added to the RBF and dissolved in THF (1.3 L) and cooled to 0 °C. Phenylmagnesium bromide (225 mL, 3M in diethyl ether, 675 mmol) was then slowly added dropwise to the solution. The reaction solution was stirred for 3 hours and extracted with EA/ _H2O . After removal of water with MgSO ₄ and distillation under reduced pressure, crude compound D (37 g, 63%) was obtained by filtration through silica using MC as a developing agent. Compound D was shown to be sufficiently pure for the next reaction.

Preparation of Compound E

Under the condition of N ₂ , DMF (40 mL) was added to RBF and NaH (1.9 g, 60% dispersion in mineral oil, 50 mL) was added to RBF and stirred. Then a solution of compound C (12 g, 33 mmol) dissolved in DMF (80 mL) was slowly added dropwise to the suspension. After the mixture was stirred for 1 hour, a solution of compound D (10.6 g, 40 mmol) dissolved in DMF (100 mL) was slowly added dropwise to the mixture. The reaction mixture was stirred for 12 hours. When the reaction was completed with _H2O , the mixture was extracted with EA/ _H2O and distilled under reduced pressure. Compound E (12 g, 61%) was obtained by column separation (condition: MC:hexane=1:10).

Preparation of compound 7

Compound E (6 g, 10 mmol), Compound I (3.2 g, 15.2 mmol), Pd(PPh ₃ ) ₄ (0.58 g, 0.5 mmol), and Na ₂ CO ₃ (2.1 g, 20 mmol) were added to the RBF. Then toluene (60 mL), EtOH (30 mL) and _H2O (10 mL) were added thereto. The reaction mixture was stirred at 90°C for 12 hours and extracted with EA/ _H2O . After removal of water with MgSO ₄ and distillation under reduced pressure, the compound 7 (3.4 g, 49%) was obtained by column separation (condition: MC:hexane=1:10).

[Preparation Example 4] Preparation of Compound 8

Preparation of Compound A

First, 2,7-dibromo-9,9-dimethylfluorene (150 g, 426 mmol) was immersed in RBF (3 L) and replaced with nitrogen, and then THF (2.1 L) was added. After cooling the solution to -78°C, n-BuLi (170 mL, 2.5M in hexane, 426 mmol) was added, and the mixture was stirred for 1 hour. Add trimethyl borate (53 mL, 469 mmol) and stir for 12 hours. When the reaction was completed with 2M HCl, the mixture was extracted with ethyl acetate (EA)/ _H20 . After removing moisture with MgSO ₄ and distilling under reduced pressure, compound A (70 g, 52%) was obtained by column separation of the obtained solid (condition: MC:hexane=1:10).

Preparation of Compound B

Compound A (70 g, 220 mmol), 2-iodonitrobenzene (50 g, 200 mmol), Pd(PPh ₃ ) ₄ (7 g, 6 mmol), and Na ₂ CO ₃ (64 g, 600 mmol) were added to the RBF. Then toluene (1 L), EtOH (0.5 L) and _H2O (0.3 L) were added. The reaction mixture was stirred at 90°C for 7.5 hours and extracted with EA/ _H2O . After removal of water with MgSO4 and distillation under reduced pressure, crude compound B (90 g) was obtained by filtration through silica using MC as a developing solvent. The next reaction was carried out 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°C for 9 hours, and the solvent was removed with distilled water. Compound C (26 g, 36%, two-step total yield) was obtained by column separation of the produced red liquid (condition: MC:hexane=1:10).

Preparation of Compound G

2,4,6-trichloropyrimidine (16.8g, 91mmol), phenylboronic acid (24.4g, 200mmol), Pd(PPh ₃ ) ₄ (5.3g, 4.6mmol), and Na ₂ CO ₃ (29g, 273mmol) Join the RBF. Then toluene (350 mL), EtOH (100 mL) and _H2O (150 mL) were added to the mixture. The reaction mixture was stirred at 80°C for 3 hours and extracted with EA/ _H2O . After removal of water with MgSO ₄ and distillation under reduced pressure, compound G (14 g, 58%) was obtained by column separation (condition: MC:hexane=1:10).

Preparation of Compound H

Under the condition of N ₂ , DMF (40 mL) and NaH (1.97 g, 60% dispersed in mineral oil, 49.3 mmol) were added to RBF and stirred. Then a solution of compound C (11.9 g, 32.8 mmol) dissolved in DMF (80 mL) was slowly added dropwise to the suspension. The mixture was stirred for about 1 hour. A solution of compound G (10.5 g, 39.4 mmol) dissolved in DMF (100 mL) was slowly added dropwise to the mixture, and the reaction mixture was stirred for 12 hrs. When the reaction was completed with _H2O , the mixture was extracted with EA/ _H2O and distilled under reduced pressure. Compound H (10 g, 51%) was obtained by column separation (condition: MC:hexane=1:10).

Preparation of compound 8

Compound H (5 g, 8.4 mmol), Compound I (2.7 g, 13 mmol), Pd(PPh ₃ ) ₄ (0.5 g, 0.4 mmol), and Na ₂ CO ₃ (1.8 g, 17 mmol) were added to the RBF. Then toluene (60 mL), EtOH (30 m) and _H2O (10 mL) were added. The reaction mixture was stirred at 90°C for 12 hours and extracted with EA/ _H2O . After removal of water with MgSO ₄ and distillation under reduced pressure, the compound 8 (3.6 g, 62%) was obtained by column separation (condition: MC:hexane=1:10).

Organic electroluminescent compounds were prepared according to the steps of Preparation Examples 1 to 4. Table 1 lists the ¹ H NMR and MS/FAB data of the electroluminescent compounds as prepared.

Table 1

[Example 1] Production of an OLED device using the organic electroluminescent compound of the present invention

OLED devices were fabricated using the organic electroluminescent materials of the present invention. First, a transparent electrode ITO film (15Ω/□) obtained from glass for OLED (manufactured by Samsung Corning) was washed sequentially with trichlorethylene, acetone, ethanol, and distilled water using ultrasonic waves, and stored in isopropanol until use.

Then, the ITO substrate was assembled in the substrate holder of the vacuum vapor deposition device, and 4,4',4"-tris(N,N-(2-naphthyl)-phenylamino)triphenylamine (2-TNATA ) is placed in a small chamber (cell) of the vacuum vapor deposition device, and then the small chamber is evacuated at 10 ^-6 Torr (torr). Subsequently, an electric current is applied to the small chamber to evaporate 2-TNATA, and then formed on the ITO substrate A hole injection layer with a thickness of 60 nanometers (nm). Next, place N,N'-bis(α-naphthyl)-N,N'-diphenyl-4,4'-diamine (NPB) in In another small chamber of the vacuum vapor deposition device; apply current to the small chamber to evaporate NPB, and then form a hole transport layer with a thickness of 20 nm on the hole injection layer.

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

Subsequently, tris(8-quinolinolato)aluminum(III)(Alq) was vapor-deposited to a thickness of 20 nm on the electroluminescent layer as an electron transport layer. Next, after vapor deposition of 8-hydroxyquinolate lithium (lithium quinolate, Liq) having the following structure with a thickness of 1nm to 2nm as the electron injection layer, another vacuum vapor deposition device is used to form aluminum with a thickness of 150nm Cathode to make OLED.

Each compound used in the OLED has been purified by vacuum sublimation at 10 ⁻⁶ torr. Therefore, it has been verified that at 6.3 volts (V), a current of 4.3 mA/cm ² flows and green light of 1310 cd/m ² is emitted.

[Example 2]

An OLED device was fabricated in the same manner as in Example 1, except that compound 6 was added as the host material of the electroluminescent layer.

Therefore, it has been verified that at 6.6V, a current of 4.3 mA/cm ² flows and green light of 1220 cd/m 2 is emitted.

[Example 3]

The OLED device was fabricated in the same manner as in Example 1, except that compound 10 was added as the host material of the electroluminescent layer

Therefore, it has been verified that at 6.4V, a current of 4.1 mA/cm ² flows and green light of 1150 cd/m ² is emitted.

[Comparative Example 1] Fabrication of OLED Devices Using Conventional Organic Electroluminescent Compounds

The OLED device manufactured by the same method as in Example 1, except that after forming the hole injection layer and the hole transport layer (using the same method as in Example [1]), bis(2-methyl-8-hydroxyquinone Phyllinyl)(p-phenylphenol)aluminum(III)(BAlq) replaces the organic electroluminescent compound of the present invention as the electroluminescent matrix material in another chamber of the vacuum deposition device. An OLED device was fabricated in the same manner as in Example 1, except that 4,4'-bis(carbazol-9-yl)linkage (CBP) was used instead of the compound of the present invention as the host material on the electroluminescent layer, and Bis(2-methyl-hydroxy-8-quinolinyl)(p-phenyl-phenol)aluminum(III)(BAlq) was used as a hole blocking layer.

Therefore, it has been verified that at 7.5V, a current of 3.9 mA/cm ² flows and green light of 1000 cd/m ² is emitted.

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

Claims (9)

1. an organic electroluminescent compound represented by chemical formula 1: chemical formula 1

chemical formula 2

in,

The definition of is the same as that in Chemical Formula 2, X represents -O- or -S-; Y represents -S-, -C(R ₁ )(R ₂ )-, -Si(R ₃ )(R ₄ )-, -N(R ₅ )- or selected from The divalent radical of the following structure;

Ar ₁ to Ar ₅ and R ₁ to R ₅ independently represent hydrogen, deuterium, (Cl-C30) alkyl, halogen (Cl-C30) alkyl, halogen, cyano, (C3-C30) cycloalkyl, 5 To 7-membered heterocycloalkyl, (C2-C30) alkenyl, (C2-C30) alkynyl, (C6-C30) aryl, (Cl-C30) alkoxy, (C6-C30) aryloxy, (C3-C30) heteroaryl, (C6-C30) aryl (Cl-C30) alkyl, (C6-C30) arylthio, mono or bis (Cl-C30) alkylamino, mono or bis (C6 -C30)arylamino, tri(Cl-C30)alkylsilyl, di(Cl-C30)alkyl(C6-C30)arylsilyl, tri(C6-C30)arylsilyl , nitro or hydroxyl, or each of them is bonded to adjacent substituents with or without fused (C3-C30)alkylene or (C3-C30)alkenylene to form a cycloaliphatic ring , a monocyclic or polycyclic aromatic ring, or a monocyclic or polycyclic heteroaromatic ring; Each of the alkyl, cycloalkyl, heterocycloalkyl, alkenyl, alkynyl, aryl, and heteroaryl groups of Ar to _Ar and _{R to R} may be further substituted by one or more substituents , the substituent is selected from deuterium, (Cl-C30) alkyl, halogen (Cl-C30) alkyl, halogen, cyano, (C3-C30) cycloalkyl, 5 to 7 membered heterocycloalkyl, ( C2-C30) alkenyl, (C2-C30) alkynyl, (C6-C30) aryl, (Cl-C30) alkoxy, (C6-C30) aryloxy, (C3-C30) heteroaryl, (C3-C30)heteroaryl with (Cl-C30)alkyl substituent, (C3-C30)heteroaryl with (C6-C30)aryl substituent, (C6-C30)aryl(Cl- C30) Alkyl, (C6-C30) Arylthio, Mono or Bis (Cl-C30) Alkylamino, Mono or Bis (C6-C30) Arylamino, Tris (Cl-C30) Alkylsilyl , Di(Cl-C30)alkyl(C6-C30)arylsilyl, tri(C6-C30)arylsilyl, nitro or hydroxyl: L ₁ to L ₃ independently represent chemical bonds or are selected from (C6-C30) arylene, (C3-C30) heteroarylene, bis (Cl-C30) alkylsilyl or bis (C6-C30) arylene a divalent group of a silyl group; and The heterocycloalkyl, heteroaryl and heteroaryl rings may contain one or more heteroatoms selected from B, N, O and S. 2. The organic electroluminescent compound as claimed in claim 1, characterized in that in Chemical Formula 1 selected from, but not limited to, the following structures,

in, The definitions of Y and Ar ₁ to Ar ₃ are the same as those in claim 1 . 3. The organic electroluminescent compound as claimed in claim 1, *—L ₁ —L ₂ —L ₃ —* of chemical formula 1 is selected from the following structures:

4. An organic electroluminescent device comprising the organic electroluminescent compound according to any one of claims 1 to 3. 5. The organic electroluminescent device as claimed in claim 4, comprising a first electrode; a second electrode; and one or more organic layers placed between the first electrode and the second electrode: wherein the The organic layer includes one or more organic electroluminescent compounds and one or more phosphorescent dopants. 6. The organic electroluminescent device as claimed in claim 5, wherein the organic layer further comprises one or more amine compounds selected from arylamine compounds and styrylarylamine compounds. 7. The organic electroluminescent device according to claim 5, wherein the organic layer further comprises one or more organic metals selected from Group 1, Group 2, Period 4 and Period 5 of the Periodic Table of Elements. Metals or complexes of transition metals, lanthanide metals and d-transition metals. 8. The organic electroluminescent device as claimed in claim 5, wherein the organic layer comprises an electroluminescent layer and a charge generating layer. 9. The organic electroluminescent device as claimed in claim 5, which is an organic electroluminescent device emitting white light, wherein the organic layer further comprises one or more organic electroluminescent devices emitting blue light, red light or green light layer.